JP5552202B2 - Additives for oil compositions - Google Patents

Description

  The present invention relates to an additive for an oil composition, mainly an additive for a fuel oil composition, particularly an additive for a fuel oil composition that is susceptible to wax formation at low temperatures.

Fuel oil, whether derived from petroleum or from plant sources, precipitates as large crystals or spherulites, such as wax plates, at low temperatures to form a gel structure that eliminates the ability of the fuel to flow. Contains prone components such as n-alkanes or methyl n-alkanoates. The lowest temperature at which the fuel will still flow is known as the pour point.
As the temperature of the fuel drops and approaches the pour point, problems arise in transporting the fuel by line or pump. In addition, wax crystals tend to clog fuel pipes, screens and filters at temperatures above the pour point. These problems are well recognized in the prior art and various additives have been proposed, many of which are used commercially to lower the pour point of fuel oil. Similarly, other additives have been proposed and used commercially to reduce size and to change the shape of the wax crystals that give shape. Small size crystals are desirable because they are less likely to clog the filter. Wax from diesel fuel is mainly alkane wax and crystallizes as platelets. Certain additives prevent this, causing the wax to become needles, and the resulting needles are easier to pass through the filter, or the crystalline porosity on the filter rather than being platelets. Form a layer. The additive can also have the effect of retaining the wax crystals as a suspension in the fuel, reducing sedimentation and thus assisting in preventing blocking.
Effective wax crystal modifications (light oil filter clogging point (CFPP) and other operational tests, as well as simulated and field performance measurements) are ethylene-vinyl acetate (EVAC) or vinyl propionate copolymer flow improvers Can be achieved.
British specification 1,086,036, European patent applications 527,322 and 518,406 describe terpolymers suitable as latexes for coatings, these terpolymers being ethylene and tertiary or quaternary. It is formed by copolymerizing a vinyl ester of an aliphatic carboxylic acid and an ester monomer which may be vinyl acetate.
British Specification 1,314,855 describes terpolymers of ethylene, vinyl acetate, vinyl esters of long chain carboxylic acids which may be saturated carboxylic acids having 8 to 30 carbon atoms. These terpolymers are described for use in lubricating oils as viscosity index improvers.
British specification 1,244,512 includes ethylene, vinyl esters of C _{2 to} C ₄ monocarboxylic acids, preferably

(Wherein X is hydrogen or a methyl group, and Y is OOCR or —COOR, where R is preferably a C ₁₀ -C ₁₆ linear or branched alkyl group.)
It describes a small amount of terpolymer of unsaturated esters having C ₁₀ -C ₂₂ alkyl radical having.
International Application No. 96/07718 discloses oil-soluble ethylene terpolymers having vinyl ester units different from ethylene units and their use as additives to improve the low temperature fluidity of fuel oil compositions. Yes. Polymer Examples 1-4 are ethylene-vinyl acetate-vinyl 2-ethylhexanoate terpolymers having various proportions of two unsaturated esters and differing in number average molecular weight and branching properties.
The polymer of WO 96/07718 is an effective cold flow improver and has the advantage of being produced from commercially available vinyl ester monomers.
EP 0 061 895 describes polyoxyalkylene compounds such as polyoxyalkylene esters and ethers which are effective as flow improvers for distillate fuels. These can be used in combination with EVA polymers.
EP 1 007 606 describes the use of ethylene / vinyl ester copolymers and terpolymers as flow improvers for distillate fuels. These can be combined with polyoxyalkylene compounds as described in EP 0061 895. The maximum vinyl ester content of the ethylene vinyl ester copolymer of EP 1 007 606 is 18 mol%, the proportion being vinyl acetate.
While the above flow improvers are generally effective, the Applicant has found a decrease in effectiveness when they are used with certain fuels. In particular, the combination of a polyoxyalkylene compound and an ethylene / vinyl ester polymer having a higher proportion of vinyl ester than vinyl acetate for use in fuel with sharp end distillates and low end points. Applicant found.

  Thus, 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, in addition to units derived from ethylene, at least One ethylene polymer has the following formula (I):

And optionally the following formula (II):

Including units having
Where R ¹ groups are each independently hydrogen or methyl; R ² groups are each independently alkyl groups having 5 or more carbon atoms; R ³ groups are each independently hydrogen Or R ⁴ groups are each independently an alkyl group having 1 to 4 carbon atoms; the proportion of units of formula (I) in the ethylene polymer is 16 to 30 mol%; ethylene polymer The total proportion of units of formula (I) and formula (II) in is 19 to 30 mol%.
The proportion of units of formula (I) in the ethylene polymer is preferably 18-30 mol%, more preferably 20-30 mol%, for example 22-28 mol%.
The total proportion of units of formula (I) and formula (II) in the ethylene polymer is preferably 20-30 mol%, more preferably 22-28 mol%. For the avoidance of doubt, it is clear that the present invention includes embodiments in which the ethylene polymer does not have units of formula (II). The proportion of units of formula (I) and (II) in the ethylene polymer was found to be important. It has been found that the performance is unsatisfactory if the total proportion of units of formula (I) and formula (II) in the ethylene polymer is more or less than the preferred range. It has also been found harmful if the proportion of units of formula (I) is too low.
Preferably R ² is a branched alkyl group having 7 to 15 carbon atoms. Units derived from monomers such as 2-ethylhexanoate, vinyl neodecanoate, tripropylene (eg isononyl) are particularly preferred.
Advantageously, R ¹ and R ³ are both hydrogen.
The polymer has at least two different repeating monomer units. That is, it can be derived from at least two different monomers. When units of formula (II) are included, the polymer has at least three different repeating monomer units. Also included are polymers that can be derived from four or more monomers. For example, the polymer can contain two or more different units of formula (I) or (II) and / or the following formula (III):

(Wherein R ⁵ is a hydrocarbyl group having 5 or more carbon atoms other than those defined for R ^4. )
The unit can be contained.
As used herein, the term “hydrocarbyl” refers to a group in which a carbon atom is bonded directly to the rest of the molecule and has hydrocarbon or predominantly hydrocarbon character. In particular, aliphatic groups (e.g. alkyl), alicyclic groups (e.g. cycloalkyl), aromatic, aliphatic, alicyclic substituted aromatic groups, aromatic substituted aliphatic, alicyclic groups There may be mentioned hydrocarbon groups. Aliphatic groups are advantageously saturated. These groups may have non-hydrocarbon substituents if their presence does not change the main hydrocarbon properties of the group. Examples include keto, halo, nitro, cyano, alkoxy, acyl. Where the hydrocarbyl group is substituted, a single (mono) substituent is preferred. Examples of substituted hydrocarbyl groups include 2-ketopropyl, ethoxyethyl, propoxypropyl. The group can also or alternatively contain atoms other than carbon in a chain or ring composed of carbon atoms. Suitable heteroatoms include, for example, nitrogen, sulfur, preferably oxygen. Advantageously, the hydrocarbyl group contains at most 30, preferably at most 15, more preferably at most 10, most preferably at most 8, carbon atoms.
The polymer may also have units of formulas other than those described above, for example, formula (IV)
-CH ₂ CHR ^6- (IV)
(Wherein R ⁶ is —OH)
Unit or following formula (V)
^{_{-CCH 3 (CH 2 R 7)}} CHR 8 - (V)
(Wherein R ⁷ and R ⁸ are each independently hydrogen or an alkyl group having up to 4 carbon atoms.)
The unit (V) is advantageously derived from isobutylene, 2-methylbut-2-ene or 2-methylpent-2-ene.

The number average molecular weight (Mn) of the at least one ethylene polymer is preferably in the range of 3000 to 8000, more preferably 4000 to 8000, and most preferably 4000 to 7000. Compared to polystyrene chains, Mn herein refers to that value as measured by GPC.
The degree of branching of the at least one ethylene polymer is preferably in the range 2 to 5, more preferably 2 to 4, for example 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 the number of methyl and methylene groups in the R ² group is modified. An example of the calculation of the degree of branching is mentioned in FIG. 1 and its description of EP 1 007 606. Details of the conditions used for NMR quantification of the degree of branching of ethylene polymers are known to those skilled in the art. For example, those skilled in the art know that NMR spectra that are not well resolved must be avoided and that appropriate conditions are chosen. Usually, an NMR spectrum obtained from a high-frequency NMR measuring instrument is preferred. A suitable NMR solvent is chosen to ensure good signal resolution of both and to minimize interference between the signal from the solvent and the signal from the polymer. Applicants have found that spectra obtained at about 40 ° C. from NMR instruments operating at 400 Mhz and above using a solvent of chloroform containing deuterium are suitable. ^{Both 1} H NMR experiments and ¹³ C NMR experiments can be used as desired.
It is also within the scope of the present invention to provide a composition 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 a polyoxyalkylene ester, a polyoxyalkylene ether, a mixed polyoxyalkylene ester / ether or a mixture thereof.
Particularly preferred are polyoxyalkylene compounds having at least one, preferably at least two C ₁₀ -C ₃₀ linear alkyl groups and a polyoxyalkylene glycol group with a molecular weight of up to 5,000, preferably 200-5,000, in said polyoxyalkylene glycols An alkylene group has 1 to 4 carbon atoms. These materials are the subject of European Patent Application 0 061 895. Such other additives are described in US Pat. No. 4,491,455.

Preferred esters, ethers or esters / ethers have the general formula
R ³¹ -O- (D) -OR ³²
(In the formula, R ³¹ and R ³² may be the same or different,
(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-
And
x is, for example, 1 to 30, the alkyl group is linear, has 10 to 30 carbon atoms, and D is a polyalkylene segment of glycol in which the alkylene group has 1 to 4 carbon atoms, for example, A polyoxymethylene, polyoxyethylene or polyoxytrimethylene moiety that is substantially linear; although some degree of branching with lower alkyl side chains (eg in polyoxypropylene glycol) can be present Preferably, the glycol is substantially linear. )
It is what has. D may also have nitrogen.
Examples of suitable glycols are substantially linear polyethylene glycol (PEG) or polypropylene glycol (PPG) having a molecular weight of 100 to 5,000, preferably 200 to 2,000. Esters are preferred, fatty acids having 10-30 carbon atoms are effective in reacting with glycols to form ester additives, and it is preferred to use C ₁₈ -C ₂₄ fatty acids, especially behenic acid. Esters can also be prepared by esterifying polyethoxylated fatty acids or polyethoxylated alcohol alcohols.
Polyoxyalkylene diesters, diethers, ethers / esters and mixtures thereof are suitable as additives, and are used for narrow boiling distillates when traces of monoethers and monoesters (often formed during the manufacturing process) are present. Diesters are preferred. Preferably a large amount of dialkyl compound is present. In particular, stearic acid diesters or behenic acid diesters of polyethylene glycol, polypropylene glycol or polyethylene / polypropylene glycol mixtures are preferred.

Other examples of polyoxyalkylene compounds are described in Japanese Patent Publications 2-51477 and 3-34790, and esterified alkoxylated amines are described in European Patent Applications Nos. 117,108 and 326,356.
The ratio of the amount of polyoxyalkylene compound and the amount of ethylene polymer in the additive composition is preferably in the range of 1:99 to 99: 1, more preferably in the range of 1:10 to 10: 1. For example, 1: 2 or 1: 1.
In a preferred embodiment, the additive composition further comprises a comb polymer. This will improve the cold flow performance when further measured by CFPP.
A comb polymer is a polymer in which a branch having a hydrocarbyl group is pendant from the polymer main chain, “Comb-Like Polymers. Structure and Properties”, NA Plate and VP Shibaev, J. Poly. Sci. Macromolecular Revs. , 8, p 117 to 253 (1974).
In general, comb polymers typically have one or more long-chain hydrocarbyl branches having 10 to 30 carbon atoms, such as oxyhydrocarbyl branches, pendants from the polymer backbone, said branches Are directly or indirectly bound to the backbone chain. Examples of indirect bonds include bonds with intervening atoms or groups, and the bonds can include covalent bonds and / or ionic bonds as in salts.
Advantageously, the comb polymer is a homopolymer having at least 25 mole percent, preferably at least 40 mole percent, more preferably at least 50 mole percent units with side chains of at least 6 atoms, preferably at least 10 atoms, or A copolymer.
Examples of preferred comb polymers include the following general formula:

(Where D = R ¹¹ , COOR ¹¹ , OCOR ¹¹ , R ¹² COOR ¹¹ or OR ¹¹ ,
E = H, CH ₃ , D, or R ¹² ,
G = H or D
J = H, R ¹² , R ¹² COOR ¹¹ , or an aryl or heterocyclic group,
K = H, COOR ¹² , OCOR ¹² , OR ¹² or COOH,
L = H, R ¹² , COOR ¹² , OCOR ¹² , COOH, or aryl,
R ¹¹ ≧ C ₁₀ hydrocarbyl,
R ¹² ≧ C ₁ hydrocarbyl or hydrocarbylene,
m and n are mole fractions, m is finite, preferably in the range of 1.0 to 0.4, and n is less than 1, preferably in the range of 0 to 0.6. R ¹¹ is preferably a hydrocarbyl group having 10 to 30 carbon atoms, and R ¹² is preferably a hydrocarbyl or hydrocarbylene group having 1 to 30 carbon atoms. )
The polymer which has can be mentioned.
The comb polymer can contain units derived from other monomers if desired or required.
These comb polymers include maleic anhydride or fumaric acid or itaconic acid and other ethylenically unsaturated monomers including styrene, such as α-olefins, or unsaturated esters such as vinyl acetate copolymers or fumaric acid. Or itaconic acid homopolymer may be sufficient. It is preferred but not essential to use equimolar amounts of comonomer, and a molar ratio in the range of 2: 1 to 1: 2 is appropriate. For example, examples of olefins that can be copolymerized with maleic anhydride include 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene.

The acid groups or anhydride groups of the comb polymer can be esterified by any suitable technique, and it is preferred, but not essential, that the maleic anhydride or fumaric acid be esterified at least 50%. Examples of alcohols that can be used include n-decan-1-ol, n-dodecan-1-ol, n-tetradecan-1-ol, n-hexadecan-1-ol, and n-octadecan-1-ol. Is included. The alcohol may also contain up to one methyl branch per chain, for example 1-methylpentadecan-1-ol or 2-methyltridecan-1-ol. The alcohol may be a mixture of normal alcohol and a single methyl branched alcohol. Although it is preferred to use pure alcohols rather than commercially available alcohol mixtures, when a mixture is used, R ¹² means the average number of carbon atoms in the alkyl group; alcohols having a branch at the 1- or 2-position Is used, R ¹² means the linear main chain segment of the alcohol.
These comb polymers are in particular the fumarate or itaconate polymers and copolymers described, for example, in European Patent No. 153176, European Patent No. 153177, European Patent No. 225688, International Application No. 91/16407. May be.
Particularly preferred fumarate comb polymers are, for example, copolymers of alkyl fumarate and vinyl acetate having an alkyl group of 10 to 20 carbon atoms, prepared by solution copolymerization of equimolar mixtures of fumarate and vinyl acetate, especially A polymer in which the alkyl group 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 preferably a 1: 1 mass mixture of normal C ₁₂ and C ₁₄ normal alcohols. Furthermore, mixtures of C ₁₂ esters and mixed C ₁₂ / C ₁₄ esters can be used advantageously. In such mixtures, the ratio of C ₁₂ to C ₁₂ / C ₁₄ is advantageously 1: 1 to 4: 1, preferably 2: 1 to 7: 2, most preferably about 3: 1 by weight. It is in the range. Particularly preferred comb polymers are those having a number average molecular weight of 1,000 to 100,000, particularly 1,000 to 30,000, as measured by gas phase osmotic pressure measurement.

Other suitable comb polymers are α-olefin polymers and copolymers, esterified copolymers of styrene and maleic anhydride, esterified copolymers of styrene and fumaric acid; mixtures of two or more comb polymers are It can be used according to the invention and, as mentioned above, such use is advantageous. Other examples of comb polymers are hydrocarbon polymers, such as copolymers of ethylene and at least one α-olefin, which preferably has at most 20 carbon atoms, for example n-decene. -1, n-dodecene-1. Preferably, the number average molecular weight of such a copolymer is at least 30,000 as measured by GPC. Hydrocarbon copolymers can be prepared by methods known in the art, for example using Ziegler catalysts.
Preferably, the ratio of the amount of comb polymer to the amount of ethylene polymer in the additive composition ranges from 1:99 to 99: 1, more preferably from 1:10 to 10: 1, such as 1: 1.
The ratio of the amount of comb polymer to the amount of polyoxyalkylene compound in the additive composition is preferably in the range of 1:99 to 99: 1, more preferably in the range of 1:10 to 10: 1, for example 1 : 1.
According to a second aspect, the present invention provides an additive concentrate composition comprising the additive composition of the first aspect and a compatible solvent therefor.
According to a third aspect, the present invention provides an oil composition comprising an oil and a small 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 an 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 compositions of the present invention is their effect on the pour point of the fuel oil. Polyoxyalkylene compounds usually have little effect on the pour point of fuel oil, if any, when used alone. The ethylene polymer defined relative to 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 chemical species reduces the pour point. It was found to be good. Thus, the composition defined relative to the first aspect of the present invention is effective in simultaneously reducing both the measured CFPP and pour point. The addition of the comb polymer increases the CFPP performance while maintaining the advantage of good pour point reduction.

Preferably, the oil is a fuel oil, for example a petroleum fuel oil, in particular a middle distillate fuel oil. Such a distillate fuel oil usually boils within a range of 110 ° C to 500 ° C, such as 150 ° C to 400 ° C. Fuel oils can include atmospheric distillates or vacuum distillates, separated gas oils, or blends in any proportion of direct distillation, thermally and / or catalytically cracked distillate. The most common petroleum distillate fuels are kerosene, jet fuel, diesel fuel, heating oil, and heavy oil. The heating oil can be straight distillate in the atmosphere and can contain a small amount of reduced pressure gas oil or separated gas oil or both, for example up to 35 wt%. The low temperature flow problems described above are usually most commonly encountered in diesel fuel and heating oil. The present invention is also applicable to vegetable fuel oils used alone or in admixture with petroleum distillates, such as rapeseed oil methyl ester (RME).
Examples of other fuel oils include Fischer-Tropsch fuel. Fischer-Tropsch fuels, also known as FT fuels, include those described as gas-to-liquid (GTL) fuels, coal conversion fuels. In order to produce such fuels, syngas (CO + H ₂ ) is first produced and then converted to linear paraffins by the Fischer-Tropsch process. Linear paraffins are then modified by methods such as catalytic cracking / reforming or isomerization, hydrocracking, hydroisomerization to obtain various hydrocarbons such as isoparaffins, cycloparaffins, aromatics. can do. The resulting FT fuel can be used by itself or in combination with other fuel components and fuel types listed herein.
The sulfur content of the fuel oil is preferably at most 0.2% by weight, in particular at most 0.05% by weight. Also suitable are fuels having lower levels of sulfur, for example, less than 50 ppm / mass sulfur, preferably less than 20 ppm, such as 10 ppm or less.
The additives of the present invention are particularly suitable for use with fuels having sharp end distillates and low endpoints (FBP). Such fuels can be characterized as having an FBP-90% distillation of 30 ° C. or less, such as 25-20 ° C., and FBP of 370 ° C. or less, eg, less than 360 ° C. FBP-90% distillation means the difference between FBP and the temperature at which 90% of the fuel volume is distilled. Examples of this type of fuel are Northern European heating oil and Japanese, narrow cut, extremely low sulfur diesel fuel.

Alternatively, the oil may be animal oil, vegetable oil or mineral oil, such as petroleum oils, castor oil, fish oil ranging from naphtha or spindle oil to SAE 30, 40 or 50 lubricating oil grades Or it may be an oxidized mineral oil. Such oils can contain additives depending on their application; examples include viscosity index improvers such as ethylene-propylene copolymers, succinic dispersants, metal-containing dispersants and zinc dialkyldithiophosphates. Wear additive.
The additive composition can also include additional cold flow improvers.
Other additives for improving the low temperature properties include polar nitrogen compounds. Such compounds are oil-soluble polar nitrogen compounds having one or more, preferably two or more substituents of formula> NR ¹³ , where R ¹³ is a hydrocarbyl group having 8 to 40 atoms. And the substituent or one or more substituents may be in the form of a cation derived therefrom. Oil-soluble polar nitrogen compounds are generally those that can act as wax crystal growth inhibitors in fuels. For example, the following compound:
Comprising one or more amine salts and / or amides formed by reacting at least one molar proportion of a hydrocarbyl-substituted amine with one molar proportion of a hydrocarbyl acid having 1 to 4 carboxylic acid groups or anhydrides thereof, Substituents of formula> NR ¹³ have the formula —NR ¹³ R ¹⁴ , where R ¹³ is defined above and R ¹⁴ is hydrogen or R ¹⁴ , although R ¹³ and R ¹⁴ are the same or different. Alternatively, the substituent constitutes a part of an amine salt and / or amide group of the compound.
Esters / amides having 30 to 300 total carbon atoms, preferably 50 to 150, can be used. These nitrogen compounds are described in US Pat. No. 4,211,534. Suitable amines are primarily C ₁₂ -C ₄₀ primary, secondary, tertiary or quaternary amines or mixtures thereof, but if the resulting nitrogen compound is oil soluble, it will be further shortened. Amines can be used and typically have about 30 to 300 total carbon atoms. The nitrogen compound preferably has at least one linear C ₈ -C ₄₀ , preferably C ₁₄ -C ₂₄ alkyl segment.

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, hydrogenated tallow amine. Examples of secondary amines include dioctacedylamine and methylbehenylamine. Amine mixtures derived from natural materials are also suitable. A preferred amine is a secondary hydrogenated tallow amine, where the alkyl group is derived from hydrogenated tallow fat composed of about 4% C ₁₄ , 31% C ₁₆ , 59% C ₁₈ .
Examples of suitable carboxylic acids and their anhydrides for preparing nitrogen compounds include ethylenediaminetetraacetic acid, carboxylic acids based on a cyclic skeleton, such as cyclohexane-1,2-dicarboxylic acid, including dialkyl spirobislactone, cyclohexene 1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, naphthalenedicarboxylic acid, 1,4-dicarboxylic acid are included. Typically these acids have about 5 to 13 carbon atoms in the cyclic portion. Preferred acids useful in the present invention are benzene dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid. Phthalic acid and its anhydride are particularly preferred. Particularly preferred compounds are amide-amine salts formed by reacting 1 mole part of phthalic anhydride with 2 mole parts of dihydrogenated tallow amine. Another preferred compound is a diamide formed by dehydrating this amide-amine salt.
Other examples are long chain alkyl or alkylene substituted dicarboxylic acid derivatives, such as amine salts of substituted succinic acid monoamides, examples of which are known in the art and are described, for example, in US Pat. No. 4,147,520. Have been described. Suitable amines may be those described above.
Other examples are condensates such as those described in European Patent Application No. 327423.
Additives for improving low-temperature characteristics are further represented by the following general formula in the ring structure:
-AN R ¹⁵ R ¹⁶
Wherein A is a linear or branched aliphatic hydrocarbylene group optionally interrupted by one or more heteroatoms, and R ¹⁵ and R ¹⁶ are the same or different and each independently 1 A hydrocarbyl group having from 9 to 40 atoms optionally interrupted by one or more heteroatoms.)
Wherein the substituent is the same or different and the compound is optionally in the form of its salt. Advantageously, A has 1 to 20 carbon atoms and is preferably a methylene group or a polymethylene group. Such compounds are described in International Application No. 93/04148.
Hydrocarbon polymers are also suitable. An example is the general formula:

(Where T = H or R ²¹ , where
R ²¹ = C ₁ ~C ₄₀ hydrocarbyl,
U = H, T, or aryl,
v and w are mole fractions, v is in the range of 1.0 to 0.0, and w is in the range of 0.0 to 1.0. )
It is what has.
Hydrocarbon polymers can be made by hydrogenating the polymer directly from monoethylenically unsaturated monomers or indirectly from polyunsaturated monomers such as isoprene and butadiene.
Examples of hydrocarbon polymers are disclosed in International Application 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 at most 28 carbon atoms. Examples of such olefins are propylene, butene, isobutene, n-octene-1, isooctene-1, n-decene-1, n-dodecene-1. The copolymer can also contain small amounts of other copolymerizable monomers, for example up to 10% by weight, for example α-olefins, and olefins other than non-conjugated dienes. A preferred copolymer is an ethylene-propylene copolymer.
The number average molecular weight of the ethylene α-olefin copolymer is preferably at least 30,000, advantageously at least 60,000, preferably at least 80,000 when measured by gel permeation chromatography (GPC) relative to polystyrene standards as described above. It is. Although there is no functional upper limit, mixing difficulties arise from high viscosity with molecular weights greater than about 150,000, and preferred molecular weight ranges are 60,000 and 80,000-120,000.
Advantageously, the molar ethylene content of the copolymer is 50 to 85 percent. More advantageously, the ethylene content is in the range of 57-80%, preferably 58-73%; more preferably 62-71%, most preferably 65-70%.

Preferred ethylene alpha-olefin copolymers are ethylene-propylene copolymers having a molar ethylene content of 62-71% and a number average molecular weight in the range of 60,000-120,000; particularly preferred copolymers have an ethylene content of 62-71% and a molecular weight of 80,000- 100,000 ethylene-propylene copolymer.
The copolymer can be prepared by any of the methods known in the art, for example using a Ziegler catalyst. Because highly crystalline polymers are relatively insoluble in fuel oil at low temperatures, the polymer must be substantially amorphous.
Other suitable hydrocarbon polymers include a number average molecular weight of preferably at most 7,500, more preferably 1,000 to 6,000, such as 2,000 to 5,000, as measured by gas phase osmometry. Suitable α-olefins are as described above or styrene, with propylene being also preferred. Advantageously, the ethylene content is 60 to 77 mole percent, but for ethylene-propylene copolymers up to 86 weight percent ethylene can be used advantageously.
The hydrocarbon polymer is most preferably an oil-soluble hydrogenated block diene polymer comprising a linear diene and at least one crystalline block obtained by end-to-end polymerization of at least one amorphous block. The amorphous block may be obtained by 1,2-configuration polymerization of linear dienes, by polymerization of branched dienes, or by a mixture of such polymerizations.
Advantageously, the block copolymer prior to hydrogenation is from butadiene alone or with butadiene
CH ₂ = CR ²² −CR ²³ = CH ₂
(Wherein R ²² is a C ₁ -C ₈ alkyl group, and R ²³ is hydrogen or a C ₁ -C ₈ alkyl group.)
Containing units derived from at least one comonomer having: Advantageously, the total number of carbon atoms in the comonomer is 5 to 8, and the comonomer is preferably isoprene. Advantageously, the copolymer contains at least 10% by weight units derived from butadiene.
In general, the one or more crystalline blocks are primarily hydrogenated products of units obtained from 1,4-polymerization or end-to-end polymerization of butadiene, and one or more amorphous blocks are Hydrogenated products of units obtained from 1,2-polymerization of butadiene or from 1,4-polymerization of alkyl-substituted butadienes.

Additive concentrate (second embodiment of the present invention)
The additive concentrate according to the invention advantageously contains 3 to 75%, preferably 10 to 65% of the additive composition in oil or in a solvent that can be mixed with oil.
Concentrates containing the additive mixed with a suitable solvent as a means for incorporating the additive into a bulk oil such as a distillate fuel are convenient and can be incorporated by methods known in the art. The concentrate can also contain other additives as required, preferably 3 to 75 wt%, more preferably 3 to 60 wt%, most preferably 10 to 50 wt%, preferably oil. Contains soluble additives. Examples of solvents are hydrocarbon solvents such as naphtha, kerosene, diesel, petroleum fractions such as heating oil; aromatic hydrocarbons such as aromatic fractions, for example sold under the trade name 'SOLVESSO' Alcohols and / or esters; organic solvents containing paraffinic hydrocarbons such as hexane, pentane, isoparaffins. Of course, the solvent must be selected in consideration of compatibility with additives and compatibility with oils.

Oil composition (third embodiment of the present invention)
The oil composition of the invention is advantageously an additive composition of the invention in a proportion by weight of 0.0005% to 1%, advantageously 0.001 to 0.1%, preferably 0.01 to 0.06%, based on the weight of the oil. Containing.

The present invention will now be described by way of example only.
CFPP performance
A sample of heating oil with an end point of 355 ° C. and FBP-90% distillation at 14 ° C. was treated with only 200 ppm of polyoxyalkylene compound (polyethylene glycol dibehenate, molecular weight about 600 (PEG 600)). This reduced the fuel CFPP to -7.5 ° C (compared to the base fuel -2.5 ° C). Further improvement could not be achieved using only the polyoxyalkylene compound.
From the same oil treated only with 400 ppm ethylene polymer having 18.6 mol% of units of formula (I), the unit containing vinyl 2-ethylhexanoate, a CFPP of −7.0 ° C. was obtained. The combined use of this ethylene polymer and the above polyoxyalkylene compound caused deterioration of CFPP performance up to -6.0 ° C.
CFPP at -3.0 ° C was obtained from the same oil treated only with 400 ppm ethylene polymer having 27.4 mol% of units of formula (I) containing units of vinyl 2-ethylhexanoate. However, in this case, the addition of the polyoxyalkylene compound further decreased the CFPP to -10.5 ° C. This example demonstrates the effectiveness of the additive composition of the present invention, that is, the combination of an ethylene polymer in which the proportion of polyoxyalkylene compound and vinyl ester is higher than vinyl acetate.
The results are shown in Table 1 below.

表1

table 1

Composition AK was composed of 200 ppm polyethylene glycol hibehenate (molecular weight about 600 (PEG 600)) and 400 ppm ethylene polymer in proportions of units of formula (I) and (II) shown in Table 1. . The last column of Table 1 shows the results for Composition AK with the addition of 200 ppm comb polymer (C ₁₂ / C ₁₄ mixed alkyl fumarate / vinyl acetate copolymer). In these three-component compositions, 200 ppm of each chemical species was used. These results show good CFPP performance and further enhancement with comb polymers.
Insufficient performance was observed for the two comparative examples. Comparative Example 1 has a large total amount of units of formulas (I) and (II), and Comparative Example 2 has a lower proportion of units of formula (I) than required in the present invention. These data show the importance of the relative and total amounts of units of formula (I) and (II).
Effect of additive composition on pour point Table 2 below lists the results of experiments measuring the pour point of fuel. The fuel used was the same as that used in the CFPP test, and the pour point was −3 ° C. without any additives.

表2

Table 2

As is clear from the results in Table 2, PEG600 alone has no effect on lowering the pour point of fuel. The addition of ethylene polymer alone (used for composition H from Table 1) lowered the pour point to -45 ° C. This is further improved by the combination of PEG600 and ethylene polymer. The combination of all three components also showed good pour point reduction. In comparison, the comb polymer alone (C ₁₂ / C ₁₄ mixed alkyl fumarate / vinyl acetate copolymer) and the combination of the comb polymer and PEG 600 were not effective.

Claims (12)

An additive composition comprising at least one polyoxyalkylene compound and at least one ethylene polymer, wherein the at least one ethylene polymer, in addition to units derived from ethylene, has the following formula (I):

Comprising units having the following formula (II):

A unit having
Where R ¹ groups are each independently hydrogen or methyl; R ² groups are each independently branched alkyl groups having from 7 to 15 carbon atoms; and R ³ groups are each Independently hydrogen or methyl; each R ⁴ group is independently an alkyl group having 1 to 4 carbon atoms; the proportion of units of formula (I) in the ethylene polymer is 16 to 30 mol% An additive composition for improving CFPP of oil, wherein the total proportion of units of formula (I) and formula (II) in the ethylene polymer is 19 to 30 mol%. The additive composition according to claim 1, wherein R ⁴ is ethyl or methyl. 3. The additive composition according to claim 1, wherein the at least one polyoxyalkylene compound comprises a polyoxyalkylene ester, a polyoxyalkylene ether, a mixed polyoxyalkylene ester / ether or a mixture thereof. At least one polyoxyalkylene compound has at least one C ₁₀ -C ₃₀ linear alkyl group and a polyoxyalkylene glycol group having a molecular weight of up to 5,000, and the alkyl group in the polyoxyalkylene glycol has 1 to 4 carbon atoms. 4. The additive composition according to claim 3 , comprising: The additive composition according to any one of claims 1 to 4 , further comprising at least one comb polymer. 6. The additive composition of claim 5 , wherein the at least one comb polymer comprises a copolymer of vinyl acetate with at least one alkyl fumarate in which the alkyl group has 10 to 20 carbon atoms. The additive composition according to any one of claims 1 to 6 , further comprising a solvent compatible with the additive composition. An oil composition comprising oil and an additive composition according to any one of claims 1 to 7 in a proportion of 0.0005% to 1% based on the mass of the oil. Use of an additive composition according to any one of claims 1 to 7 for improving the CFPP of an oil. The use according to claim 9 , wherein the oil comprises a fuel oil having an FBP-90% distillation of 30 ° C or less and an FBP of 370 ° C or less. A method for improving the CFPP of the oil, the oil, comprising adding an additive composition according to any one of claims 1 to 7, wherein said method. 12. The method of claim 11 , wherein the oil comprises a fuel oil having an FBP-90% distillation of 30 ° C. or less and an FBP of 370 ° C. or less.