JPS63245488A - Fluidity improver for fuel oil - 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] [Field of Industrial Application] The present invention relates to a fluidity improver for fuel oil, which effectively miniaturizes wax crystals present in fuel oil and improves the flowability of wax in the oil. This invention relates to a fuel oil flow improver that can be dispersed.

[Conventional technology]

When petroleum middle distillate oils, such as diesel oil and A heavy oil, are exposed to low temperatures in winter or in cold regions, the wax-like substances contained therein precipitate and clog the filters in the fuel piping system of diesel engines. This causes problems such as impeding engine starting, etc., and the fuel oil itself becomes semi-solid or solid and loses fluidity, causing oil pipes to become clogged. This problem tends to increase further due to the recent trend toward heavier crude oil or the tighter quantity of kerosene and diesel oil, and appropriate measures to address this problem are desired.

Many studies have been conducted to solve these problems, including ethylene-vinyl acetate copolymer, ethylene-(meth)acrylate copolymer, polyethylene, halogenated polyalkylene, and alkyl (meth)acrylate. Polymers, condensates of chlorinated paraffins and naphthalene, nitrogen-containing derivatives of alkenylsuccinic acids, and aliphatic dicarboxylic acid amides have been reported. These modifiers adsorb to wax that precipitates when fuel oil is exposed to low temperatures or eutectic with it to change the shape and size of wax crystals, thereby improving fuel efficiency at low temperatures. It improves the fluidity of oil.

[Problem that the invention seeks to solve]

However, in recent years, there have been changes in the demand for fuel oil, and with regard to diesel oil in particular, during times of strong demand for kerosene, etc., the proportion of low boiling point parts in diesel oil is decreasing, and the boiling point range is becoming narrower. There are situations where it is not possible. For gas oils with such narrow boiling point ranges, even if various fluidity-improving additives are added, including the conventionally used ethylene-vinyl acetate (EVA) copolymer, it is difficult to maintain good low-temperature properties. It is difficult to demonstrate fluidity. In other words, an additive that improves the fluidity of fuel oils with narrow boiling point ranges that has the ability to effectively lower CFPP (cold filtration plugging point, IP306) and PP (pour point) at the same time has not been discovered in the past. It has not been. Furthermore, it has been desired to develop additives that are effective for a wide variety of fuel oils with various boiling point ranges.

In addition, when fuel oil with conventional fluidity improvers added is slowly cooled in a storage tank or drum pipe, there is a drawback that the precipitated wax is not dispersed in the oil and often settles to the bottom. is desired.

[Means for solving problems]

Under these circumstances, the inventor of the present invention has conducted intensive research and found that it is possible to impart good low-temperature fluidity to a wide range of types of fuel oil, that is, it is possible to lower both CFPP and PP at the same time. The present invention has been completed by discovering a compound that can disperse precipitated wax in oil and reduce sedimentation when slowly cooled.

That is, the present invention provides (a) a polymer containing 80% by weight or more of (meth)acrylate having a linear alkyl group having 12 to 16 carbon atoms as a structural unit, and having a molecular weight of 10,000 to 100,00;
and (b) an ester of an alkylene oxide adduct of an amine compound and a monohydric carboxylic acid, wherein the ester molecule contains a small number (both of which contain one linear saturated alkyl group having 14 to 30 carbon atoms). Compounds with weight ratio (a): (b) =
2:98 to 98:2, and if necessary, (c) nitrogen-containing derivatives of alkenylsuccinic acids, condensates of chlorinated paraffins and naphthalene, nitrogen-containing derivatives of long-chain alkylene dicarboxylic acids, nitrogen-containing tricarboxylic acids. Fal1
(a) and (b) 1 to 100 parts by weight of the total amount of a compound selected from the group consisting of a reaction product of a diisocyanate compound and a dialkylamine
The object of the present invention is to provide a fluidity improver for fuel oil, characterized in that it contains 250 parts by weight.

Component (a) used in the present invention has a molecular weight of 10,000 to ioo, oo, and has a (meth)acrylate having a linear alkyl group having 12 to 16 carbon atoms as an essential constituent monomer.

It is necessary that the (meth)acrylate is contained in the structural unit in an amount of 80% by weight or more.

Examples of the above-mentioned (meth)acrylates include C1□~CI&
Examples include (meth)acrylates having a straight chain alkyl group. Carbon number 12-1 in lowering the pour point
(Meth)acrylates having 6 linear alkyl groups are preferred. These alkyl (meth)acrylates may be used alone or in a mixture. Further, if necessary, it may be copolymerized with a monomer that can be copolymerized with these alkyl (meth)acrylates. In that case, the alkyl (meth)acrylate content in the copolymer is 80% by weight or more.

Seven polymers that can be copolymerized with alkyl (meth)acrylates
Examples include those having a carbon-carbon double bond such as a vinyl group in the molecule, such as styrene, α-methylstyrene, α-olefin, vinyl acetate, maleic anhydride, maleic acid, acrylic acid, and methacrylic acid. , acrylonitrile, vinylpyridine, N-vinylpyrrolidone, N,
Examples include N-dimethylaminoethyl (meth)acrylate, (meth)acrylamide, and ethylene oxide adducts of methacrylic acid;
It is not limited to.

The production of the (co)polymer may be the same as in the case of copolymerization of general acrylic esters or methacrylic esters, for example, (meth)acrylate having a linear alkyl group having 12 to 16 carbon atoms and other The monomers are treated with a small amount of a radical-generating catalyst (organic or inorganic filtrate) in the presence or absence of an inert solvent for the reaction system, such as a hydrocarbon solvent (aromatic hydrocarbon solvents such as toluene and xylene). oxides, organic ab-based compounds, etc.) in an inert gas atmosphere, usually by heating to 60°C to 140°C.

The number average molecular weight of the copolymer of the present invention is determined by gel permutation chromatography.

Examples of the amine compound serving as a raw material for the ester component (b) include alkylamines, alkylolamines, polyamines, fatty acid alkylolamides, and the like.

Specific examples include methylamine, ethylamine, butylamine, octylamine,
Examples include monoalkylamines such as laurylamine, stearylamine, and behenylamine, and dialkylamines such as dimethylamine, diethylamine, dibutylamine, dioctylamine, dilaurylamine, distearylamine, and dialkylamine.

Examples of alkylolamines include ethanolamine, isopropanolamine, jetanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, dihydroxypropylamine, bis(
These include dihydroxypropyl)amine and tris(dihydroxypropyl)amine.

Examples of polyamines include ethylenediamine, propylenediamine, hexamethylenediamine, xylylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine,
Polyamines such as polyethyleneimine, ethyleneimine adducts of the aforementioned mono- and dialkylamines, or polyamines such as acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, valmitic acid, stearic acid Some are partially amidated with fatty acids such as , arachidic acid, behenic acid, and lignoceric acid.

Examples of fatty acid alkylolamide include acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid,
A monohydroxyl alkyl amine such as monoa, alkylamine, ethanolamine, and isopropanolamine is amidated with a fatty acid such as stearic acid, arachic acid, behenic acid, or lignoceric acid, or a product amidated with the above-mentioned fatty acid. Examples include jetanolamide, diisopropaturamide, dihydroxypropylamide, bis(dihydroxypropyl)amide, and the like.

In the alkylene oxide adduct of the amine compound constituting the ester component (b), the number of moles of alkylene oxide added is preferably 1 to 100 moles, more preferably 1 to 30 moles, per mole of the amine compound. . When more than 100 moles of alkylene oxide are added, CFP
This is not preferable because the degree of decrease in P becomes small. Preferred alkylene oxides are ethylene oxide, propylene oxide, and butylene oxide, which may be used alone or in combination, and also include cases where several types of alkylene oxides are connected randomly or in a block form.

The fatty acids forming the residue of the linear saturated fatty acid having 14 to 30 carbon atoms that occupies at least one of the carboxylic acid residues of the ester compound of component (b) include myristic acid, palmitic acid, stearic acid, and arachidic acid. , behenic acid, lignoceric acid, cerotic acid, montanic acid, melisic acid, etc., and preferred ones are palmitic acid, stearic acid, arachidic acid, behenic acid and lignoceric acid. These may be used alone or as a mixture; for example, mixed fatty acids obtained by hydrogenating fatty acids obtained by hydrolyzing natural fats and oils such as beef tallow, rapeseed oil, and fish oil can also be used as they are.

Other carboxylic acids forming the carboxylic acid residue of the ester include carboxylic acids having 1 to 30 carbon atoms, such as carboxylic acids having 1 to 30 carbon atoms;
13 straight chain saturated fatty acids (acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid, pelargonic acid, lauric acid, etc.), unsaturated fatty acids (oleic acid, linoleic acid, lycylic acid, etc.), oxyacids (glycolic acid, lycylic acid, etc.) acid, etc.), branched fatty acids (2-ethylhexanoic acid, isostearic acid, etc.), aromatic carboxylic acids (benzoic acid, naphthalene carboxylic acid, etc.), and mixtures of two or more of these. Among these, preferred are the above straight chain saturated fatty acids and unsaturated fatty acids.

Component (b) has at least one ester in the ester molecule.
However, it is desirable to have two or more residues of aliphatic linear saturated carboxylic acid having 14 to 30 carbon atoms in order to exhibit CFPP lowering ability. .

Alkylene oxide adducts can be prepared by various methods. For example, alkylene oxides having 2 to 4 carbon atoms (ethylene oxide, propylene oxide, butylene oxide, etc.) are mixed in liquid or gaseous form while heating alcohol in the presence of a catalyst such as caustic alkali, using an appropriate solvent if necessary. Add and react.

Random addition polymerization in which two or more types of alkylene oxides are mixed and reacted together, or block addition polymerization in which one type of alkylene oxide is sequentially added first may be performed.

The obtained polyoxyalkylene ether is used as it is,
Alternatively, after purification to remove unreacted substances and catalysts, a catalyst such as para-toluenesulfonic acid is usually added and esterified with carboxylic acid under heating. The progress of the esterification reaction can be confirmed by monitoring the acid value, hydroxyl value, saponification value, etc.

The ratio of (a) and (b) is (a): (b) in weight ratio.
)・2:98 to 98:2. Preferably (a):
(b) =15:85 to 75:25, and the effect of the present invention is greatest when used within this range.

The component (c) used in the present invention will be explained.

Nitrogen-containing derivatives of alkenylsuccinic acids, condensates of chlorinated paraffins and naphthalene, nitrogen-containing derivatives of long-chain alkylene dicarboxylic acids, nitrogen-containing derivatives of tricarboxylic acids, reaction products of diisocyanate compounds and dialkylamines (urea and/or The nitrogen-containing derivatives of alkenylsuccinic acid include alkenylsuccinic acid containing an alkenyl group having 10 to 22 carbon atoms or its anhydride. Mono- or sialgyl amines, reactants (amides and/or salts) with (poly)alkylene polyamines,
Preferred is a reaction product of alkenylsuccinic acid or its anhydride containing a C9° to C2□ alkenyl group and a dialkylamine having two CI4 to C2° alkyl groups.

As a condensate of chlorinated paraffin and naphthalene, 0
Examples include condensates of chlorinated paraffins of 8 or more and naphthalene. Its molecular weight is usually 2,000 to 8,00
It is in the range of 0.

As nitrogen-containing derivatives of long-chain alkylene dicarboxylic acids,
Examples include those described in JP-A-56-36588. Specifically, it is a reaction product of a dicarboxylic acid having an unsubstituted or alkyl-substituted alkylene group having a straight chain alkylene chain of C3° or more and a dialkylamine, preferably a dicarboxylic acid having a straight chain alkylene group of C1 to CZ2. and a dialkylamine having two alkyl groups of CI4 to C2□.

As a nitrogen-containing derivative of tricarboxylic acid, JP-A-56-
84795, specifically, it is a reaction product of an aromatic, aliphatic or alicyclic tricarboxylic acid and a dialkylamine, preferably a reaction product of trimellitic acid and a CI4 to C2□ alkyl group. It is a reaction product with a dialkylamine having two.

Further, examples of reaction products of diisocyanate compounds and dialkylamine include those described in JP-A-56-93796. Specifically, aromatic, aliphatic,
and a reaction product of an alicyclic diisocyanate and a dialkylamine, preferably tolylene diisocyanate and C
It is a reaction product of dialkylamine having two alkyl groups of I4 to C2□.

Among (C), preferred are nitrogen-containing derivatives of alkenylsuccinic acid. When used in combination with (c), it is effective for oil types with a large amount of wax.

(a) and (b) have a weight ratio of (a):(b) -2
: It is essential to use it in the range of 98 to 98:2.

Outside this range, it is difficult to obtain the effects of the present invention.

In addition, when (a), (b), and (c) are used together,
(c) can be used in a range of 1 to 250 parts by weight per 100 parts by weight of (a) + (b), but 2
Preferably, 5 to 150 ffili parts are used.

The fuel oil to which the fuel oil flow improver of the present invention is applied is:
Mainly distillate fuel oil and distillate fuel oil mixed with residual oil, and among these, it is a suitable improver for kerosene, light oil, and A heavy oil.

When adding the improver of the present invention to fuel oil, the amount added is usually 0.0001 to 0.5% (weight %, same hereinafter), preferably 0.001 to 0.1%.

The improver of the present invention is an ethylene-
Copolymer fluidity improvers represented by vinyl acetate copolymers, condensation fluidity improvers represented by chlorinated paraffin-naphthalene condensates, and reactants of alkenylsuccinic acid and dialkylamine. Excellent at very low addition levels for fuel oils with very narrow boiling point ranges and fuel oils with high n-paraffin content, where none of the nitrogen-containing derivative fluidity improvers can lower CFPP. It exhibits excellent CFPP lowering ability and PP lowering ability, and also exhibits excellent CFPP lowering ability and PP lowering ability for fuel oils with a relatively wide boiling point range where the effects of fluidity improving additives are likely to occur. Furthermore, the improver of the present invention can effectively disperse wax precipitated at low temperatures in a wide range of types of fuel oils having various boiling point ranges.

A part of the component (b) in the fuel oil river fluidity improver of the present invention is disclosed in JP-A-59-149988 and JP-A-5.
No. 9-189192, JP-A-60-1.66389,
Each is described in Japanese Patent Application Laid-Open No. 60-281198.

That is, JP-A-59-149988, JP-A-59-18
No. 192 uses a part of component (b) alone or in combination of one or more monomers selected from olefins, ethylenically unsaturated alkyl carboxylates, and saturated fatty acid vinyls. Examples are given. However, the composition described in this publication cannot satisfy either CFPP lowering ability or PP ability. JP-A-60-1
No. 66389 contains a part of component (b), a polymer of one or more monomers selected from olefins, ethylenically unsaturated alkyl carboxylates, and saturated fatty acid vinyl, and an oil-soluble surfactant. An example is given. JP-A-60-281198 describes an example in which a part of component (b) is used alone or/and in combination with the above polymer and an oil-soluble surfactant. however,
These cannot satisfy both CFPP lowering ability and PP lowering ability.

Component (b) alone exhibits some CFPP-lowering ability, but its PP-lowering ability is completely insufficient.

Various compounds showing PP lowering ability have been reported so far, but when used in combination with component (b), in most cases (b)
) impairs the C, PPP lowering ability of the component.

These polymers are the same as in this case.

As a result of our intensive research efforts to develop a more effective fuel oil fluidity improver, we have arrived at the present invention.

That is, components (a) and (b), which are specific poly(meth)acrylate polymers, and (c) as necessary.
The fuel oil flow improver of the present invention using a combination of components can be used for fuel oils with a very narrow boiling point range in which none of the conventional fuel oil flow improvers can reduce CFPP, and for n-
Excellent CFP even for fuel oil with high paraffin content
The fuel oil improver of the present invention exhibits P lowering ability and PP lowering ability, and further has a function of effectively dispersing wax in fuel oil precipitated at low temperatures into the oil.

That is, (a) and (b) or (a) and (b) and (
When c) is used, the function described above is achieved.

A combination of (a) and (b), and a combination of (a) and (b)
) and (c) are both excellent improvers, but the latter is more effective for oil types with a high wax content.

The compound (b) component of the fuel oil fluidity improver of the present invention is an ester compound having a polyether bond in the molecule, and examples of such compounds include diesters of polyoxyalkylene glycols represented by the following formula: Although this compound shows a certain degree of CFPP lowering ability for distillate fuel oils with a narrow boiling point range, it is inferior in terms of CFPP lowering ability for fuel oils having a wide boiling point range. Further, it had almost no ability to disperse the wax content in the fuel oil that precipitates during slow cooling.

[For production]

Although the details of the reason why the fuel oil flow improver of the present invention can impart good low temperature flow properties and good wax dispersibility to a wide range of types of fuel oils are not known,
This is thought to be due to the following characteristics. That is, the ester compound according to the present invention is considered to have the function of dispersing the wax crystals and the linear saturated alkyl group, which are thought to have the property of adsorbing or eutectic to the wax precipitated from the fuel oil, into the fuel oil. General formula-eAO
) -- (in the formula, A is an alkylene group and n represents the number of moles added) are connected through an ester bond, so the eutectic with Wanx goes smoothly, resulting in wax crystals. It is presumed that the nucleation effect is exerted.

Further, the compounds (a) and (c) are adsorbed onto the surface of the precipitated wax crystal, controlling crystal growth and changing the shape of the crystal. This can be observed under a microscope under slow cooling. Components (b) and (c) have a synergistic effect when used together with component (a), and by making the precipitated wax crystals finer and dispersing them in oil, they can be applied to a wide range of fuel oils. Shows outstanding CFPP lowering ability, PP lowering ability, and wax crystal dispersion ability.

These effects can be well understood by observing the dispersion state of wax crystals precipitated while slowly cooling fuel oil to which the improver of the present invention has been added, and by observing the state of wax crystal precipitation under a microscope. be done.

In fact, when fuel oil to which the improver of the present invention was added was slowly cooled to precipitate wax crystals and then filtered through a 44μ filter, it could be effectively filtered, and most of the precipitated wax crystals passed through the filter.

As described above, since the improver of the present invention exhibits the above-mentioned effects, it is useful as a wide range of fuel oil fluidity improvers.

〔Example〕

Next, the present invention will be explained with reference to production examples and examples, but the present invention is not limited thereto.

Production Example 1 501 parts (1 mol) of ethylenediamine (EO) I@ (10 mol adduct of ethylenediamine with ethylene oxide), 1026 parts (3 mol) of behenic acid, and 7.6 parts (0.5% by weight) of para-toluenesulfonic acid. 2! Place 4 of them in a flask and heat to 140~1 under a nitrogen stream while removing the produced water.
The mixture was heated and stirred at 60"C for 3 hours to obtain an ester. The acid value of this ester was 7.8.

Production Example 2 Triethanolamine (EO) + (PO) + () 3 moles of ethylene oxide and 3 moles of propylene oxide adduct of triethanolamine] To 1 mole, 1.5 stearic acid was added.
mol, 513 parts (1.5 mol) of behenic acid, and 0.5% by weight of para-toluenesulfonic acid were reacted in the same manner as in Production Example 1 to form triethanolamine ([0)! (po)
An esterified product of No. 3 was obtained. The acid value of this ester is 10.
It was 1.

Production Example 3 1 mole of triethylenetetramine (PO) 6 (adduct of 6 moles of propylene oxide of triethylenetetramine), 3 moles of hardened rapeseed fatty acid, and 0.5% by weight of paratoluenesulfonic acid were reacted in the same manner as in Production Example 1. An esterified product of triethylenetetramine (PO) b was obtained.

Production Example 4 Behenylamine (EO) 4 (4 mol ethylene oxide adduct of behenylamine) 1 mol and hydrogenated fish oil fatty acid 2
A molar amount of the esterified product was obtained in a manner similar to Production Example 1.

Production Example 5 Behenic acid jetanolamide (EO) + s (ethylene oxide 15 mole adduct of behenic acid jetanolamide)
An esterified product of 1 mol of bepenic acid and 2 mol of bepenic acid was obtained in a manner similar to Production Example 1.

Production example 6 Polyethyleneimine (average molecule 1t300) (EO)
z.

An esterified product of 1 mole (20 moles of ethylene oxide adduct of polyethyleneimine with an average molecular weight of 1300) and 3 moles of hardened beef tallow fatty acid was obtained by a method similar to Production Example 1.

Examples 1 to 11 and Comparative Examples 1 to 7 Using Production Examples 1 to 6, the following invention products 1 to 11 and comparative products 1 to 7 were created.

Invention Product 1 Compound of Production Example 1 40 parts Invention Product 2 Compound of Production Example 2 40 parts Invention Product 3 Compound of Production Example 3 40 parts Invention Product 4 Compound of Production Example 4 40 parts Invention Product 5 Production Example 5 40 parts Invention product 6 Compound of Production Example 6 40 parts Invention product 7 Compound of Production Example 1 25 parts Invention product 8 Compound of Production Example 1 25 parts Invention product 9 Compound of Production Example 2 25 parts Invention product 10 Compound of Production Example 4 25 parts Invention Crystal 11 Compound of Production Example 5 20 parts Note) Vinylpyrrolidone 5% by weight *3 Having an alkyl group having 16 to 18 carbon atoms.

Product name Firmin D86 (manufactured by Kao Corporation) Comparative crystal 1 Comparative product 2 Comparative product 3 Comparative product 4 Polymer 1" 50 parts Comparative product 5 Polymer 2" 50 parts Comparative product 6 Polymer 1" 20 parts Comparative product 7 Polymer 3°6 30 parts Note) Book 4 Polymer 1 A copolymer of ethylene and vinyl acetate, Amoco-
547D (manufactured by Amoco Chemical Co., USA, number average molecular weight 2
Solvent bone (approx. 50% by weight) was removed from 600 (proportion of vinyl acetate 43% by weight) (100゛C130n+n+I1g
, 20 hours).

*5 Polymer 2 ACP-512, a copolymer of ethylene and acrylic acid
0 (manufactured by Allied Chemical Co., USA, number average molecular weight 3500
, acid value 120) 47g, lauryl alcohol 45g1
0.2 g of para-toluenesulfonic acid and 100 g of xylene
After esterifying the mixture in g for 10 hours while refluxing xylene and distilling off water under a nitrogen stream, it was gradually poured into a large excess of methanol, and the precipitate was filtered off and dried. It is something that

Umbrella 6 Polymer 3 Acryloid 152 which is polyalkyl methacrylate
(Manufactured by Rohm and Haas, USA, number average molecule 11700
0, the number of carbon atoms in the alkyl group is 12 to 20).

The above-mentioned products of the present invention and comparative products were diluted with an aromatic solvent, and
It was used in the test as a 0% concentrate. The flowability and dispersibility of the fluidity improvers of the present invention and comparative products containing these 'a-thick materials were blended with the light oils or A heavy oils shown in Table 1, and their fluidity and dispersibility were tested. The results are shown in Table 2.

In addition, the fluidity test is a low temperature clogging test (CFPP, British Standard IP-309) and a pour point test (PP, JIS K
-2269).

In addition, for the dispersibility test, 100ml of the test oil was placed in a 100ml graduated cylinder, and the test oil was heated from room temperature to the point of contact (CP, JIS) in a low temperature bath with a programmable temperature controller.
L2269) was cooled at a rate of 1°C per minute to a temperature 10°C higher than the landing point, then slowly cooled at a rate of FC per hour to a temperature 5'C lower than the landing point, and left at that temperature for 2 hours. , observed the condition. Judgment was made based on the ratio of the wax content (1 layer) of the test oil produced by wax precipitation to the transparent layer of the upper supernatant.

The dispersibility of wax is better as the ratio of the dispersed layer of wax is higher; ○ is when the ratio is 70% or more, and 7 is 50% or more.
Less than 0% was marked Δ, and less than 50% was marked x.

As is clear from Table 1 and Table 2, the fuel oil flow improver of the present invention can be used not only for fuel oils with a narrower boiling point range than conventional fuel oil flow improvers, but also for fuel oils with a wider boiling point range. Even in fuel oil, it has excellent CFPP lowering ability and PP lowering ability even when added in a small amount, and furthermore, wax that precipitates when the fuel oil is slowly cooled can be well dispersed in the fuel oil.

This can prevent clogging of filters in the fuel piping system, clogging of oil pipes, etc.

Claims (1)

[Scope of Claims] 1(a) having a straight-chain alkyl group having 12 to 16 carbon atoms (
A polymer containing 80% by weight or more of meth)acrylate as a structural unit and having a molecular weight of 10,000 to 100,000;
) An ester of an alkylene oxide adduct of an amine compound and a monohydric carboxylic acid, which has at least one linear saturated alkyl group having 14 to 30 carbon atoms in the ester molecule, in weight ratio (a): (b) = 2:98 to 98:2, and if necessary, (c) Nitrogen-containing derivatives of alkenylsuccinic acid, condensates of chlorinated paraffins and naphthalene, nitrogen-containing derivatives of long-chain alkylene dicarboxylic acids, tricarboxylic acids. A compound selected from the group consisting of a nitrogen-containing derivative of an acid and a reaction product of a diisocyanate compound and a dialkylamine is added in an amount of 1 to 25 parts by weight based on 100 parts by weight of the total of (a) and (b).
A fluidity improver for fuel oil, characterized in that it contains 0 parts by weight. 2. The fluidity improver for fuel oil according to claim 1, which contains component 2(c) in an amount of 25 to 150 parts by weight based on 100 parts by weight of the total of (a) and (b). Sex improver. The fluidity improver for fuel oil according to claim 1, wherein the amine compound 3(b) is an alkylamine, an alkylolamine, a polyamine or a fatty acid alkylolamide. 4. The fluidity improver for fuel oil according to claim 1 or 2, wherein the component (c) is a nitrogen-containing derivative of alkenylsuccinic acid.