JPS60195193A - Low temperature characteristics improving additive and distillatory fuel oil containing same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Mineral oils containing paraffin wax are characterized in that their fluidity decreases as the temperature of the mineral oil decreases. This loss of fluidity causes the wax to eventually form platelets (sponge-like masses that incorporate mineral oil into them).
This is due to crystallization.

Various additives have been known in the past that act as wax crystal modifiers when mixed with waxy mineral oils. These compositions change the shape and size of the wax crystals and reduce the amount of wax and oil and the adhesion between the crystals so that the oil can retain its fluidity at low temperatures. be.

Divine pour point depressants have been described in the literature and some of them are used commercially. For example, U.S. Pat. No. 3,048,479 discloses ethylene and 03-C as flow depressants for fuels, particularly heating oils, diesel and jet fuels.

The use of copoly7-vinyl esters such as vinyl acetate is taught. Hydrocarbon polymer flow reducers based on ethylene and higher α-olefins such as propylene are also known. U.S. Pat. No. 3,961,916 describes the use of copolymer mixtures in which one copolymer is a wax crystal nucleating agent and the other copolymer is a growth inhibitor to control wax crystal size. Teach.

GB 1263152 suggests that wax crystal size could be controlled by the use of copolymers with a lower degree of side chain branching.

As a co-additive for ethylene/vinyl acetate copolymers, di-n-
It has been shown, for example, in British patent no.
It is proposed in No. 016. British Patent No. 1469016
According to the publication, these polymers can be C6C+a alkyl esters of unsaturated C,-C,dicarboxylic acids, especially lauryl fumarate and laurylhexadecyl fumarate. The materials used are typically mixed esters (polymer A) having an average of about 12 carbon atoms. It is noteworthy that this additive has been shown to be ineffective on lower final boiling point "normal" fuels (Fuels 1 and 2).

With the increasing diversity of distillate fuels, types of fuels have emerged that cannot be treated with existing additives or that require uneconomically high levels of additives. In order to make them commercially usable, it is necessary to reduce their pour points to the necessary extent and to control the wax crystal size to enable cryogenic filtration. One particular group of fuels for which such problems exist are relatively narrow and/or
It has a low boiling point region. Fuels are often characterized by their initial boiling point, final boiling point, and temperature between which a certain volume percent of the initial boiling point is distilled. 2
The 0% to 90% distillation points differ within the range of 70 to 100°C, and/or the 90% boiling point is 10 to 25°C of the final boiling point, and/or the final boiling point is between 340 and 370°C. Fuels that are, in some cases, little affected by additives, or require very high levels of additives, have proven to be particularly difficult to process.

All distillations described herein are according to ASTM D86.

With the rise in oil prices, increasing the production of distillate fuels and distillation fuels that require unacceptably high processing levels from an economic point of view or that are difficult to process with common additives in distillate fuels. It has become important for refiners to optimize their operations using what are known as sharp cuts.

Typical sharply fractionated fuels have a 90% to final boiling range of 10-25°C, and a 20-90% boiling range usually below 100°C, typically 50-100°C. Both types of fuel have a final boiling point above 340<0>C, generally in the range 340<0>C to 370<0>C, particularly in the range 340<0>C to 365<0>C.

In addition to this, it may be necessary to reduce what is known as the pixel density of distillate fuel oils. Note that the equinox here is the temperature at which wax crystals begin to precipitate from the fuel oil when cooling is desired.

This is a fuel oil with a typical boiling point of 120-5.
It is necessary to apply it to difficult-to-process products such as the entire range of distillate fuel oils in the 00°C range.

Copolymers of ethylene and vinyl acetate, which have traditionally been widely used to improve the flow of distilled fuels by hand, are effective in treating the above-mentioned narrow boiling point and/or sharp fraction fuels. This was not discovered.

Moreover, it has not been found to be effective to use the mixture described in GB 1469.016.

However, the inventors have discovered that copolymers containing very specific alkyl groups, such as certain di-n-alkyl fumarate/vinyl acetate copolymers, control wax crystal size to enable filtration. and the above-mentioned difficult-to-process fuels (UK Patent No. 146901)
It has been found that additive No. 6 is effective in lowering the pour point of all types of fuels, including lower final boiling point fuels for which additive No. 6 was ineffective. We have also found that the copolymers are effective in lowering the equinox point of many fuel oils across the entire range of distillate fuel oils.

In particular, the inventors have determined that the average number of carbon atoms in the alkyl groups in the copolymer should be between 12 and 14, and that at most 10% by weight of comonomer with alkyl groups containing more than 14 carbon atoms is preferred. contains at most 2 comonomers with alkyl groups containing less than 12 carbon atoms.
It was found that it should be 0% by weight. These copolymers are particularly effective when used in combination with other cold flow improvers that are not themselves effective for these types of fuels.

Therefore, the present invention provides mono-ethylenically unsaturated C3-C
Additives containing polymers or copolymers containing at least 25 wt. however,
The above polymer or copolymer has an n-alkyl group having an average carbon number of 12 to 14 carbon atoms, and the ester polymer or copolymer has an average carbon number of 14 to 14 carbon atoms.
It contains no more than 10% by weight of ester monomers having alkyl groups having more than 12 carbon atoms, preferably no more than 20% by weight of ester monomers having alkyl groups having less than 12 carbon atoms.

This additive is preferably used in an amount of 0.0001 to 0.5% by weight based on the weight of the distilled petroleum fuel oil, and the invention also encompasses such treated distillate fuels.

The copolymers can also be di-n-alkyl esters of dicarboxylic acids containing C,2/C1, alkyl groups, and contain from 25 to 70% by weight of vinyl esters, alkyl acrylates, methacrylates or alpha-lambda reflexes.
I can do two things.

The polymer preferably used in the present invention has a number average molecular weight of 1000 to 1
00,000, preferably 1.000 to 30,000.

Nisdel dicarboxylic acids useful in the production of the above polymers have the general formula (where R1 and R2 are hydrogen or C1-C, an alkyl group such as methyl, and R3 is an average of
Direct button alkyl no λ and R1 are C'0OR3, hydrogen or C1-C4 alkyl group, preferably COOR3)
It can be expressed by

These can be prepared by esterifying certain mono- or di-carboxylic acids with appropriate alcohols or alcohol mixtures. Also, other CI2 to CI4
Examples of unsaturated esters include CI2-CI4 alkyl acrylates and methacrylates.

The dicarboxylic acid mono- or di-ester monomers can be copolymerized with varying amounts, for example from 5 to 70 mole percent, of other unsaturated esters or melefins. Such other esters have the formula: (where R is hydrogen or C, -C, alkyl group, R''
is -COOR""' or -00CR"" (but R""
is a branched or unbranched C3-C5 alkyl group) and R'' is R or hydrogen. Examples of these short chain esters include methacrylates, acrylates, fumarates. , malate, vinyl esters, preferred are vinyl esters such as vinyl propionate and vinyl arsenate. More specific examples include methyl methacrylate, isopropenyl acetate and butyl and isobutyl acrylate.

Preferred copolymers of the invention have average CI 2 to CI
It contains 40 to 60 mol% of 4-dialkyl fumarate and 60 to 40 mol% of vinyl acetate.

Preferred ester copolymers are treated under an atmosphere of an inert gas such as nitrogen or carbon dioxide to remove oxygen.
The reaction is usually accelerated using a peroxide or azo-type catalyst such as benzoyl peroxide or azoisobutyronitrile, generally at a temperature in the range of 20°C to 150°C, and heptane, benzene, cyclohexane, or white oil. can be conventionally prepared by polymerizing ester monomers in solution in a hydrocarbon solvent such as ester monomer.

The additives of the present invention are particularly effective when used in combination with other additives commonly known for improving the cold flow properties of distillate fuels, but are one of the combinations for improving the cold flow behavior of fuels. It can also be used alone as one.

The additives of the invention are polyoxyalkylene esters, ethers, esters/ethers and mixtures thereof, in particular at least one, preferably at least two Cl0-
C50 direct button saturated alkyl group and molecular weight 100-5,00
0, preferably 200 to 5,000 polyoxyalkylene glycol groups, and are particularly effective when used with polyoxyalkylene glycols in which the alkyl groups contain 1 to 4 carbon atoms. These substances are the subject of European Patent Publication No. 006189.5Δ2.

The esters, ethers, and esters/ethers used in the present invention preferably have the following structural formulas.

R-0-(△)-0-R' where R and R' may be the same or different, (]) ]n-alkyl1 (ii) n-alkyl-C1] (iii) n-alkyl-○-C-(CH2), -
is preferred. In the formula, the alkyl group has 10 to 30 carbon atoms.
is a linear saturated group, and Δ is a polyoxyalkylene segment of a glycol having an alkylene group having 1 to 4 carbon atoms, such as a substantially straight polyoxymethylene, polyoxy/ethylene or polyoxytrimethylene moiety. shows.

Furthermore, as in polyoxypropylene glycol,
Although some degree of branching with short alkyl side chains is acceptable, it is preferred that the glycols be substantially straight.

A generally preferred recall is a molecular weight of about 100 to 5.0.
00, preferably from about 200 to 2.000, substantially straight polyethylene glycol (PEG) and polypropylene glycol (PPG).

Esters are preferred, fatty acids having from 10 to 30 carbon atoms are suitable for reacting with the glycols mentioned above to form ester additives, and fatty acids having from 18 to 24 carbon atoms are preferably used, especially behenic acid.

The ester can also be prepared by esterification of polyethoxylated fatty acids or polyethoxylated alcohols.

Polyoxyalkylene diesters, diethers, Nisdels/Nisdels and mixtures thereof are preferred as additives; the diesters are preferably used for narrow boiling range distillates, with small amounts of monoethers and monos Esters may be present or formed during manufacture. In short, the presence of most of the dialkyl compounds is important for the performance of the additive. Preference is given to diesters of stearic acid or behenic acid, especially of polyethylene glycol, polypropylene glycol or polyethylene/polypropylene glycol mixtures.

Ethylenically unsaturated ester copolymer flow improvers can be used as additives in the present invention. This unsaturated monomer copolymerizable with ethylene includes unsaturated mono- and diesters represented by the following general formula. Formula, where R6 is hydrogen or a methyl group, and R5 is -00CR.

A group represented by (where R8 is hydrogen or a group having 1 to 28 carbon atoms,
More generally 1 to 17 carbon atoms, preferably 1 to 17 carbon atoms
8) or -C
A group represented by OOR6 (where R8 has the same meaning as above but is not hydrogen), R7 is hydrogen or the same as above -
COOR.

In the case of a monomer in which 126 and R7 are hydrogen and R5 is -coorz6, a monocarboxylic acid having 1 to 29 carbon atoms, more generally 1 to 18 carbon atoms, preferably 2 to 18 carbon atoms, is used. Vinyl alcohol esters with 5 monocarboxylic acids are included. Examples of vinyl esters that copolymerize with ethylene include vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl isobutyrate, with vinyl acetate being preferred. Further, as the copolymer, one containing 20 to 40% by weight, preferably 25 to 35% by weight of vinyl ester is suitable. The copolymer may be a mixture of two copolymers as described in US Pat. No. 3,961,916.

These copolymers preferably have a number average molecular weight of 1000 to 6000, more preferably 1000 to 3000, as measured by vapor phase osmotic pressure method.

The additives of the present invention can be used in distillate fuels in combination with ionic or nonionic polar compounds that act as wax crystal growth inhibitors in the fuel oil. Polar nitrogen-containing compounds have been found to be particularly effective when used in combination with glycol esters, needles or Nisdels/ethers, and these three-component mixtures are within the scope of this invention. These polar compounds are preferably amine salts and/or amides, and the amides include:
At least 1 mole of hydrocarbon-substituted amine and 1 to 4 carbon atoms
It is formed by reaction with 1 mole of a hydrocarbon acid or its anhydride having a carboxylic acid group. Generally, the total number of carbon atoms is 30 to 300, preferably 50 to 15.
0 esters/amides can also be used. These nitrogen compounds are described in US Pat. No. 4,211,534.

As the amine, primary, secondary, tertiary or quaternary amines having a long chain with a carbon number of 12 to 40 are preferred, or if the obtained nitrogen compound is oil-soluble, a chain shorter than that indicated in "-" is preferred. Amines can also be used. 1x-C1 Usually, amines having a total carbon number of about 30 to 300 are used. The nitrogen compound Toji-C preferably has at least one straight alkyl segment having 8 to 40 carbon atoms, more preferably 1/1 to 24 carbon atoms.

Suitable amines include primary, secondary amines, etc. , tertiary or quaternary amines, among which secondary amines are preferred. Tertiary and quaternary amines can only form amine salts. Examples of amines include tetradecylamine, cocoaamine,
Examples include hydrogenated tallow amine. Further, examples of the secondary amine include dioctadecylamine and methyl-behenylamine. Mixtures of amines are also suitable, as are many amine mixtures derived from natural substances. Hydrogenated beef tallow secondary amines having the formula HNR, R2 are preferred. In addition, in the formula, R1 and R2 are approximately C5.4%, C,6
It shows an alkyl group derived from a hydride of beef tallow composed of 31% and 59% C.

Carboxylic acids suitable for producing the above nitrogen compounds and their anhydrides include cyclohexanedicarboxylic acid,
Examples include cyclohexane dicarboxylic acid, cyclopencune dicarboxylic acid, di-α-naphthylacetica acid, and naphthalene dicarboxylic acid. Generally, these acids have a cyclic moiety having 5 to 13 carbon atoms. Preferred acids in the present invention are 0-phthalic acid, p-phthalic acid and m-phthalic acid.
benzenedicarboxylic acids such as phthalic acid.

Among these, 0-7 talic acid or its anhydride is particularly preferred.

A particularly preferred amine compound is an amide-amine salt obtained by reacting 1 mole of phthalic anhydride with 2 moles of dihydrogenated beef tallow amine.

Other preferred compounds are diamides obtained by dehydrating the above amide-amine salts.

When used as a mixture, for every part of polyoxyalkylene ester, ether or ester/ether,
The amount of the polymer of the present invention containing an n-alkyl group having an average carbon number of 12 to 14 is preferably 0.5 to 20 parts by weight, more preferably 1.5 to 9 parts by weight.

The additives of the present invention can be used with any type of distilled petroleum in the boiling range of 120 to 500°C, but especially distilled petroleum
It is effective for improving the low-temperature filterability of fuel oil in which the difference between the distillation temperature between 90% and 90% is 100°C or less, and/or the difference in distillation temperature between 90% and final distillation is 10 to within the range of 25°C and/or its final distillation temperature is between 340 and 3
It is particularly effective in improving the flow properties of distillate fuels in the 70°C range.

The additive system of the present invention is preferably supplied as a concentrate for addition to the main distillate fuel. These concentrates can also contain other additives if necessary. These concentrates preferably contain from 3 to 75% (hereinafter abbreviated as %) of additives, preferably from 3 to 60%, most preferably from 10 to 50%, preferably in solution in oil. be.

Such concentrates are also within the scope of this invention.

The invention is illustrated by the following examples, in which the effectiveness of the additives of the invention as pour point depressants and filterability improvers was compared to other similar additives by the following tests.

One method is to determine the response of mineral oils to additives using cold filter plugging point tests.
o1nt Te5t"" CF P P "). This method is 1, Jouranl of th
e 1stitute of Petroleum
, Volume 52, No. 510. June 1966 issue, p. 173-
185.

This test correlates with the cold flow properties of middle distillates in diesel vehicles.

Briefly, this method involves placing a sample of mineral oil in a bath maintained at about -34°C and non-linearly cooling at a rate of about -34°C/min. The cooled mineral oil was tested intermittently, starting at a temperature of at least 2°C above the image point and decreasing in 1°C increments, for flowability through a narrow screen within a preset time. This test was conducted using a test apparatus in which the lower end of the pipette was connected to an inverted funnel that was below the surface of the mineral oil sample. The mouth of the funnel extends over a 350 mesh screen with an area of 12 mm in diameter. This intermittent test is started by aspirating the top end of the pipette and the mineral oil rises through the screen to a point representing a volume of 20+ηl in the pipette. After rising, the mineral oil is immediately returned to the CFPP tube. This test is performed by decreasing the temperature in 1° C. increments until no mineral oil can be filled into the pipette within 60 seconds. Then, this temperature is defined as the CFPP temperature. Then, the difference between the CFPP of mineral oil without additives and the CPPP of the same mineral oil with additives is compared to the CPPP of mineral oil with additives.
P drop. The most effective flow improvers provide greater CFPP drop with the same concentration of additive.

Another method to examine the fluidity improvement effect is the fluidity improvement distillate operability test (dis'
till operability test
"DOTTest") conditions. This test is a slow cooling test and correlates to the bombing of stored heated fuel oil. In this test, the cold fluidity of the fuel containing the additive was determined by the following DOT test.

300 mβ of mineral oil was cooled linearly at a rate of 1° C./hour to the test temperature and maintained at this temperature. After being maintained at the test temperature for 2 hours, a surface layer of about 20 m of unusually large wax crystals, which tend to form at the mineral oil/air interface during cooling, was observed.
Remove as 12. Put the wax in the bottle
After stirring slowly to disperse, add the CFPP assembly. Next, open the stopper, draw in mercury at a pressure of 500, and pass through the filter into a calibrated receiver with 200% fuel oil.
Close the stopper when m1 is filled. If 200 mR is collected within 10 seconds through the obtained mesh, record P as s and the flow rate has become too slow indicating that the filter has become clogged. In this case, it is recorded as FΔIL.

20.30.40.60.8(), 100.120.1
Using a CFPP filter assembly with filter screens of 50, 200, 250 and 350 mesh numbers, determine the finest mesh (largest mesh number) through which the fuel oil will pass. The larger the mesh number through which the wax containing fuel oil passes, the smaller the wax crystals become, and the greater the fluidity-improving effect of the additive. It should be noted that the same treatment level with the same flow improving additive does not give exactly the same results for the two fuel oils.

Pour point is ASTM D97 or 150mj! A visual observation method is used in which a test additive and a sample of 100 mj2 of fuel oil are placed in a bottle with a narrow neck and cooled at a rate of 1°C/hour from a temperature 5°C above the temperature at which wax precipitates.
Determine by one method. The fuel oil sample was tilted or turned upside down at 3°C intervals to examine its fluidity. Fluid samples (F,!) are those that flow easily when tilted, and semi-fluid samples (semi-F) are those that flow when turned upside down, and are solid. The sample (referred to as S) does not move at all even if it is turned upside down.

The following fuel oils were used in the experiment.

Cheeks ω 0■■ %　m　co　−q　+n　c.

Accent prison ω so ω ω 畷ρ $ co 0 0 w gu0 Cgu ma oo cq 子0') (Iri c'ocitsu 0tsu ρtsu @ 8 0
■ C) t=tn cx)-N prisoner to N to 蛯 cheek N prisoner size D ■ FJEo 0 c-ゎ■ residence to cqcy ← − 耶 -のへ d size - ward 1 1 ml 1 Mi; <l:o (The following additives were used in the JO country.

0 Additive 1: Shidarano esterified polyethylene glycol with an average molecular weight of 400 with 7 mol of behenic acid.

0 additive 2: direct ta C, 2 and 5 of CI4 alcohol
A 0:50 (weight ratio) mixture was reacted with fumaric acid to form a mixture of C, 2/C, alkyl fumarate and vinyl carbonate in a ratio of 1.1 (mole ratio), and azo A copolymer obtained by co-drying a solution using diisobutyronitrile.

The results are shown below.

[:' STMr197 to FPP Fuel additive amount (ppm) CFPP drop Pour point Δ No additive -5℃ -9℃ 1 500 -8℃ 3℃ -6℃ 2 500 -3℃ -2℃ -15℃2': 1
300:200 -9℃ 4℃ -18℃2: l
600:400 -11℃ 6℃ -18℃13 11
1 addition -4℃ -6℃ 1 120 -6'C 1300-8℃ 4℃ 2 180 -15℃ 2300 =2℃ -2℃ 2: , 1 180/120 -11t 7℃ -1
8℃2: ] 300/200 -13℃ 9℃ -
21℃No addition -4℃ -6℃ 1 500 -8℃ 4℃ -3℃ 1 1000 -7℃ 3℃ 2 1000 -2℃ -2℃ 2: 1 300/200 = 6℃ 2℃ -12℃
2: I 600/400 -10℃ 6℃ -15
℃ The additive of the present invention has a number average molecular weight of 2500 and a vinyl acetate content of 36% by weight. 13 parts by weight of an ethylene/vinyl acetate copolymer and a number average molecular weight of 3500 and a vinyl acetate content of about 13% by weight. Polymer formulation 6 consisting of 1 part by weight of ethylene/vinyl acetate copolymer
Additive 3, an oil solution containing 3% by weight, was compared in the DOT test.

D Oi” test - 911 m of additive required to pass through DOT (120 mesh) at 10°C Fuel Mixture of 3 parts of additive 31 and 2 parts of 2 △ > 3.
OO0700 B 800 250 C1,500700 I) 1.250 500 E >1.500 300 Additive 1 (
2 parts) in admixtures (3 parts) with various fumarais) / +! The vinyl itate copolymer was tested and the following results were given.

■ ÷ ,,11- 0 艷J 2 8 8 8 -1I! ! I 1 j 1 ) = く の り ト 0 0 り さ す ■ O ω = 1c /) 類 国 S Cq O -d () -4-10Q o の
From 25 different alcohols (but having an average of 12 to 1 j3.5 carbon atoms in the alkyl group) (The various 7-malate/vinyl acetate copolymers were tested for CFPP and visual pour point tests in mixtures similar to those in the previous examples, and the results are as follows.

Fuels B and C are fuel FΔSTM D in the following example
-86 distillation °C IBP 20% 50% 90% FBP182 25
Used with 4 285 324 343. The results are shown in the table below. If the additive has no flow-reducing effect,
CFPP value cannot be measured. This is because fuel cannot be used without flow drop.

→-(E) 1(K=agony-L-ya:? to prisoner to N to C'JC%J
■ Δ phase Δ 8 + 1 4 l-I Button II ++ ω Dimensions -T-G-I (l The additive was obtained by reacting 2 moles of hydrogenated beef tallow amine with phthalic anhydride. Also tested in combination with partial amide (additive 4), the C F P I) drop in fuel B is as follows:

Additives CFPP lowering additive 4 (250 ppm) 6 Additive 3 (100 ppm) c, 2/ C, 4F/ VΔ (250 ppm) Additive 4
(300ppm) Additive 1 (100ppm>6C,2/CI4F/VΔ(100'ppm)
Additive 4 (250ppm) 0 CI2/CI4 F/VA (250ppm
) The fact that the additives of the present invention have the effect of lowering the equinox point of distilled fuel oils is demonstrated by the standard cloud point test (IP -219 or Δ
STM-D2500) i is thus confirmed, and it is also estimated by differential scanning calorimetry analysis using the Mettler T Cool the fuel oil at a rate of 2°C/min from a temperature at least 10°C higher than the point, and estimate the wax precipitation temperature at the temperature indicated by the differential scanning calorimeter + 6°C. Using.

Fuel G HI J K L M Cloud point t -15-12-7-8-13-12-3 Distillation °C Initial boiling point 1741871.9022016418220
020% 23123825726019822527
490% 31431532231431831433
2@Final boiling point 3433383433413483513
The results of measurements using a differential scanning calorimeter on a fuel oil containing the same CI 47 malate/vinyl acetate copolymer used previously and 0.2% by weight of Additive 2 are shown below.

Cloud Point ℃ Fuel Additive 2C14 Fumarate Vinyl Acetate Copolymer G -' 18.5 -20 1-1 -'14 -15 1-8 zu, J -12 K -17-1,8 L -, 1,5-17 The equinox point of the fuel containing 0.2% by weight of Mzu-6 CI47 Murray)/acetic acid e-vinyl copolymer was also determined by ASTM cloud point test.The results are shown below.

ΔSTM, D 2500 G -20 H-15,5 ■-9 J, -1i K -21- 1, -18 M -4 Continued from page 1 Priority claim [Phase] August 10, 1984 [Phase] United Kingdom o Inventor Alpert Loggia (GB) [Co., Ltd.]
8420435 New Chassis, USA o7o6o War L/
7 rounds top road 23

Claims (1)

[Scope of Claims] (1) Where the average carbon number of the n-alkyl group is 12 to 14, and the n-alkyl ester contains only 10% by weight of a comonomer containing an alkyl group having more than 14 carbon atoms. An additive characterized in that it contains a polymer or copolymer containing at least 25% by weight of a mono-ethylenically unsaturated low alkyl ester of a mono- or dicarboxylic acid having from 4 to 8 carbon atoms, the additive containing from 120 to 500
Additive for improving the low-temperature properties of distilled petroleum fuel oils having a boiling point of c. The additive described in section 1). (1) The average number of carbon atoms in the n-'j' alkyl group is 12 to 14.
is mono-ethylenically unsaturated and has 4 to 8 carbon atoms in which n-alkylnisder contains not less than 10% by weight of a comonomer containing an alkyl group with more than 14 carbon atoms.
0 polymers or copolymers containing at least 25% by weight of low alkyl esters of mono- or dicarboxylic acids.
．． 001~0.5% by weight, boiling point range is 120~
Distilled petroleum fuel oil at 500℃. (4) A mono-ethylenic monomer in which the n-alkyl group has an average carbon number of 12 to 14, and the n-alkyl ester contains no more than 10% by weight of a comonomer containing an alkyl group having more than 14 carbon atoms. Additive concentrate comprising an oil solution containing 3 to 75% by weight of a concentrate containing a polymer or copolymer containing at least 25% by weight of n-alkyl ester of a saturated mono- or dicarboxylic acid having 4 to 8 carbon atoms.