JP2011122135A - Low temperature fluidity improver for fatty acid methyl ester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low temperature fluidity improver capable of efficiently improving low temperature fluidity and a CFPP of a fatty acid methyl ester. <P>SOLUTION: The low temperature fluidity improver for a fatty acid methyl ester comprises following components (X) and (Y). The component (X) is a copolymer (X1) obtained by copolymerizing a monomer (a) (general formula (1)) and a monomer (b) (general formula (2)); and/or a copolymer (X2) obtained by copolymerizing the monomer (a), the monomer (b), and another monomer (c) having a carbon-carbon double bond. The component (Y) is a copolymer (Y1) obtained by copolymerizing a monomer (d) (general formula (3)) and a monomer (e) (general formula (4)); and/or a homopolymer (Y2) obtained by polymerizing the monomer (e). In general formula R<SP>1</SP>CH=CHR<SP>2</SP>(1), R<SP>1</SP>and R<SP>2</SP>are each independently an oxygen atom, a 1-100C hydrocarbon group which may be interrupted by -C(=O)-, -C(=O)O-, -OC(=O)-, or -OC(=O)O-, or a hydrogen atom. General formula (2) is shown in figure (2). In general formula R<SP>3</SP>CH=CH<SB>2</SB>(3), R<SB>3</SB>is a hydrogen atom or a phenyl group. In general formula CH<SB>2</SB>=CR<SP>4</SP>(LR<SP>5</SP>) (4), R<SB>4</SB>is a hydrogen atom or a methyl group, L is -C(=O)O- or -OC(=O)-, and R<SB>5</SB>is a 1-40C hydrocarbon group. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a low temperature fluidity improver for fatty acid methyl esters and a biodiesel fuel composition containing the low temperature fluidity improver.

Fossil fuels such as gasoline, light oil, and oil are mainly used as fuel oil, but when these fuels are consumed, carbon dioxide is released into the atmosphere, which is a major cause of environmental problems such as global warming. It is considered that. For these reasons, various methods have been considered to reduce the release of carbon dioxide into the environment.
One method has been proposed to use biofuel. Biofuels are fuel oils obtained mainly from plants, and are used as fuels for automobiles, etc. by mixing 100% ethanol, methanol, fatty acid methyl esters, etc. from plants or fossil fuels. It is. Because biofuel is made from plants that consume carbon dioxide in the atmosphere, even if biofuel is released into the atmosphere as carbon dioxide by combustion, new plants that are the source of biofuel consume that carbon dioxide , Carbon dioxide in the atmosphere does not increase (carbon dioxide circulation). Such biofuels have been started in various forms as described above, but can be directly applied to existing engine systems and do not require engine improvements. The study of biodiesel fuel containing most biofuels is most advanced.

For example, Patent Document 1 discloses a biodiesel fuel composition in which an antioxidant is added to biodiesel fuel, and the biodiesel fuel contains 1% or more of oleic acid methyl ester and / or linoleic acid methyl ester, As a main component, it comprises one or more fatty acid methyl esters having C4 to C25 carbon atoms, and the antioxidant comprises a natural component and / or a synthetic component, and is based on the total mass of the fatty acid methyl ester. A biodiesel fuel composition, which is added at a ratio of 0.001% to 5%; a method of using the biodiesel fuel composition, wherein A method of using a biodiesel fuel composition characterized by mixing at a volume ratio of 1 to 100% is disclosed.
However, biodiesel fuel containing fatty acid methyl ester has a high pour point, and the fluidity of the fuel deteriorates when the fatty acid methyl ester is blended at a high concentration or when used in cold regions even at low concentrations. In order to spread biodiesel fuel, it was necessary to improve the low temperature fluidity of biodiesel fuel and the clogging point (CFPP) during low temperature filtration.

（式中、ｎは２以上の整数、Ｘ^１〜Ｘ^８はそれぞれ独立して、水素、直鎖炭化水素又は分岐炭化水素基、もしくは炭素数３以上のシクロ炭化水素基を示す。）

（式中、Ｘ^９、Ｘ^１０のうちいずれか一方は炭素数８乃至２４の直鎖又は分岐の炭化水素基で、もう一方は水素を示し、Ｘ^１１はＮＲ^１Ｒ^２又はＮＨＲ^３、Ｘ^１２はＨ^＋、ＨＮ^＋ＨＲ^４Ｒ^５又はＨＮ^＋Ｈ_２Ｒ^６である。また、Ｒ^１〜Ｒ^６はそれぞれ独立して炭素数８乃至２４の炭化水素基を示す）
が開示されている。 On the other hand, various low temperature fluidity improvers are known for existing diesel fuels. For example, Patent Document 2 discloses that a compound A represented by the following general formula (1) and a compound B represented by the following general formula (2) have a mass ratio (compound A) :( compound B) of 1:99. Or low-temperature fluidity improver for fuel oil to be contained so as to be 50:50:

(Wherein, n are integers of 2 or more, X ¹ to X ⁸ are each independently hydrogen, a straight-chain hydrocarbon or branched hydrocarbon group, or of 3 or more cycloalkyl hydrocarbon group having a carbon.)

(In the formula, one of X ⁹ and X ¹⁰ is a linear or branched hydrocarbon group having 8 to 24 carbon atoms, the other represents hydrogen, and X ¹¹ represents NR ¹ R ² or NHR ³ , X ¹² is H ⁺ , HN ⁺ HR ⁴ R ⁵ or HN ⁺ H ₂ R ⁶ , and R ^{1 to} R ⁶ each independently represents a hydrocarbon group having 8 to 24 carbon atoms)
Is disclosed.

  Patent Document 3 discloses (A) a fatty acid selected from linear saturated fatty acids having 8 to 28 carbon atoms and linear unsaturated fatty acids having 8 to 28 carbon atoms, and (B) a pour point depressant and Oil improver for low sulfur gas oil containing at least one modifier selected from low temperature fluidity improver and having a sulfur content of 0.05% by mass or less; pour point depressant is chlorinated paraffin and naphthalene The oil improver for low sulfur gas oil, which is at least one selected from condensate, condensate of chlorinated paraffin and phenol, polyalkyl methacrylate, polybutene, polyalkyl styrene, polyvinyl acetate and polyalkyl acrylate; low temperature fluidity The improver is at least one selected from ethylene-vinyl acetate copolymer, ethylene-alkyl acrylate and alkenyl succinic acid amide. Sulfur light oil oiliness improver is disclosed.

JP 2007-016089 A JP 2005-187581 A JP-A-10-110175

  However, low-temperature fluidity improvers such as those described in Patent Documents 2 and 3 described above are not very effective for fatty acid methyl esters, and more effective low-temperature fluidity improvers for fatty acid methyl esters are desired. Yes.

Accordingly, an object of the present invention is to provide a low temperature fluidity improver that can efficiently improve the low temperature fluidity of fatty acid methyl esters and CFPP.
Another object of the present invention is to provide a biodiesel fuel composition containing the low temperature fluidity improver.

Ｒ^３ＣＨ＝ＣＨ_２ （３）
（Ｒ^３は水素原子又はフェニル基を表す）
ＣＨ_２＝ＣＲ^４（ＬＲ^５） （４）
（式中、Ｒ^４は水素原子又はメチル基を表し、Ｌは−Ｃ（＝Ｏ）Ｏ−又は−ＯＣ（＝Ｏ）−を表し、Ｒ^５は炭素数１〜４０の炭化水素基を表す。）
である。 Accordingly, the present inventors have intensively studied and found a low-temperature fluidity improver capable of greatly improving the low-temperature fluidity of fatty acid methyl ester and CFPP, and have reached the present invention.
That is, the present invention is a low temperature fluidity improver for fatty acid methyl esters comprising the following (X) component and (Y) component,
(X) copolymer (X1) obtained by copolymerizing monomer (a) represented by general formula (1) and monomer (b) represented by general formula (2); and / or monomer A copolymer (X2) obtained by copolymerizing (a), a monomer (b), and a monomer (c) having a carbon-carbon double bond other than the monomer (a) and the monomer (b);
(Y) copolymer (Y1) obtained by copolymerizing monomer (d) represented by general formula (3) and monomer (e) represented by general formula (4); and / or ( A low temperature fluidity improver for fatty acid methyl esters, characterized in that it is a homopolymer (Y2) obtained by polymerizing e):
R ¹ CH═CHR ² (1)
Wherein R ¹ and R ² are each an independent oxygen atom, —C (═O) —, —C (═O) O—, —OC (═O) — or —OC (═O) O—. Represents a hydrocarbon group having 1 to 100 carbon atoms which may be interrupted, or a hydrogen atom)

R ³ CH═CH ₂ (3)
(R ³ represents a hydrogen atom or a phenyl group)
CH ₂ = CR ⁴ (LR ⁵ ) (4)
(In the formula, R ⁴ represents a hydrogen atom or a methyl group, L represents —C (═O) O— or —OC (═O) —, and R ⁵ represents a hydrocarbon group having 1 to 40 carbon atoms. .)
It is.

  Moreover, the biodiesel fuel composition of the present invention contains the above-mentioned low-temperature fluidity improver for fatty acid methyl esters and biodiesel fuel.

  The effect of the present invention is to provide a low-temperature fluidity improver that can efficiently improve the low-temperature fluidity of fatty acid methyl ester and CFPP.

  The terms “homopolymer” and “polymer” as used herein represent polymers obtained by various polymerization methods such as radical polymerization, ionic polymerization, cocondensation and the like, unless otherwise specified. “Copolymer” represents any of random copolymers, block copolymers, and random / block copolymers obtained by various polymerization methods such as radical polymerization, ionic polymerization, and cocondensation, unless otherwise specified. .

  First, the component (X) will be described. Component (X) is a copolymer (X1) obtained by copolymerizing monomer (a) represented by general formula (1) and monomer (b) represented by general formula (2); and / or ( This is a copolymer (X2) obtained by copolymerizing a), (b), and a monomer (c) having a carbon-carbon double bond other than (a) and (b).

In (a) represented by the general formula (1), R ¹ and R ² are each independently an oxygen atom, —C (═O) —, —C (═O) O—, —OC (═O). It is a C1-C100 hydrocarbon group or hydrogen atom which may be interrupted by-or -OC (= O) O-.

  Examples of the hydrocarbon group not interrupted by an oxygen atom, —C (═O) —, —C (═O) O—, —OC (═O) — or —OC (═O) O— include, for example, alkyl Group, alkenyl group, cycloalkyl group, aryl group and the like.

  Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, secondary butyl group, tertiary butyl group, amyl group, isoamyl group, hexyl group, heptyl group, isoheptyl group, octyl group. Group, isooctyl group, 2-ethylhexyl group, nonyl group, isononyl group, decyl group, dodecyl (lauryl) group, tridecyl group, tetradecyl (myristyl) group, pentadecyl group, hexadecyl (palmityl) group, heptadecyl group, octadecyl group ( Stearyl) group, nonadecyl group, icosyl group, eicosyl group, heicosyl group, heneicosyl group, docosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, triacontyl group, tetracontyl group, pentacontyl group, hexacosyl group Butyl group, Heputakonchiru group, Okutakonchiru group, Nonakonchiru group, Hekuchiru group and the like.

  Examples of the alkenyl group include a vinyl group, 1-methylethenyl group, 2-methylethenyl group, propenyl group, butenyl group, isobutenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, decenyl group, pentadecenyl group, octadecenyl group, Examples include icocenyl group, pentacocenyl group, and triacontenyl group.

  Examples of the cycloalkyl group include a cyclohexyl group, a cyclopentyl group, a cycloheptyl group, a methylcyclopentyl group, a methylcyclohexyl group, a methylcycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a methylcyclopentenyl group, and a methylcyclohexenyl group. Group, methylcycloheptenyl group and the like.

  Examples of the aryl group include phenyl group, naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-vinylphenyl group, 3-isopropylphenyl group, 4-isopropylphenyl group, 4 -Butylphenyl group, 4-isobutylphenyl group, 4-tertiarybutylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, 4-octylphenyl group, 4- (2-ethylhexyl) phenyl group, 4-dodecyl A phenyl group etc. are mentioned.

（式中、ｍは０又は１を表し、Ｒ^Ａ及びＲ^Ｂは炭素数１〜９９の炭化水素基を表す。Ｒ^Ａ及びＲ^Ｂの炭素数の和は９９以下である）

（式中、ｍは０又は１を表し、Ｒ^Ａ及びＲ^Ｂは炭素数１〜９９の炭化水素基を表す。Ｒ^Ａ及びＲ^Ｂの炭素数の和は９９以下である）

（式中、ｍは０又は１を表し、Ｒ^Ａ及びＲ^Ｂは炭素数１〜９９の炭化水素基を表す。Ｒ^Ａ及びＲ^Ｂの炭素数の和は９９以下である）

（式中、ｍは０又は１を表し、Ｒ^Ａ及びＲ^Ｂは炭素数１〜９９の炭化水素基を表す。Ｒ^Ａ及びＲ^Ｂの炭素数の和は９９以下である）
−（Ｒ^Ｃ）_ｎ−Ｏ−Ｒ^Ｄ （１３）
（式中、ｎは０又は１を表し、Ｒ^Ｃ及びＲ^Ｄは炭素数１〜１００の炭化水素基を表す。Ｒ^Ｃ及びＲ^Ｄの炭素数の和は１００以下である） In (a) represented by the general formula (1), R ¹ and R ² are each an oxygen atom, —C (═O) —, —C (═O) O—, —OC (═O) —. Alternatively, it may be a hydrocarbon group interrupted by —OC (═O) O—, and examples of such a group include a hydrocarbon group containing a ketone group, an ester group, a carbonate group, an ether group, a hydroxyl group and the like. One or two or more may be contained in the same molecule. R ¹ and R ² are a group that can be interrupted by an oxygen atom, —C (═O) —, —C (═O) O—, —OC (═O) —, or —OC (═O) O—. Among them, groups represented by the following general formulas (9) to (13) are preferable, and among them, it is more preferable to use the general formula (10) or the general formula (11) having an ester group:

(In the formula, m represents 0 or 1, and R ^A and R ^B represent a hydrocarbon group having 1 to 99 carbon atoms. The sum of the carbon numbers of R ^A and R ^B is 99 or less)

(In the formula, m represents 0 or 1, and R ^A and R ^B represent a hydrocarbon group having 1 to 99 carbon atoms. The sum of the carbon numbers of R ^A and R ^B is 99 or less)

(In the formula, m represents 0 or 1, and R ^A and R ^B represent a hydrocarbon group having 1 to 99 carbon atoms. The sum of the carbon numbers of R ^A and R ^B is 99 or less)

(In the formula, m represents 0 or 1, and R ^A and R ^B represent a hydrocarbon group having 1 to 99 carbon atoms. The sum of the carbon numbers of R ^A and R ^B is 99 or less)
_{^{- (R C) n -O-}} R D (13)
(Wherein, n represents 0 or 1, ^{R C} and ^{R D} are the sum of the carbon number of the .R ^C and ^{R D,} which represents a hydrocarbon group having 1 to 100 carbon atoms is 100 or less)

Since the effect as a low temperature fluidity improver is high, R ¹ and R ² are oxygen atoms, —C (═O) —, —C (═O) O—, —OC (═O) — or —OC (= O) A hydrocarbon group or a hydrogen atom not interrupted by O- is preferred. In particular, a combination in which R ¹ is an alkyl group and R ² is a hydrogen atom is preferable, and the carbon number of R ¹ is preferably 1 to 40 and more preferably 4 to 22. Polyolefin is a general term for polymers synthesized using simple olefins and alkenes as monomers, but in the present invention, a polyolefin having a carbon-carbon double bond is treated as (a).

  In addition, (a) may consist of only 1 type and may be a 2 or more types of mixture.

  When the amount of (a) and (b) used when polymerizing the component (X) is other than 100% by mass, the copolymer (X2) containing (c) is obtained. (C) may be any monomer having a carbon-carbon double bond, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, methacrylic acid. Nonyl, stearyl methacrylate, glycidyl methacrylate, phenyl methacrylate, toluyl methacrylate, benzyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, 2-hydroxyethyl methacrylate, methacrylic acid-2 -Hydroxypropyl, ethylene oxide adduct of methacrylic acid, 2- (dimethylamino) ethyl (meth) acrylate, γ- (methacryloyloxypropyl) trimethoxysilane, trifluoromethyl (meth) acrylate (Meth) acrylic acid 2,2,2-trifluoroethyl, (meth) acrylic acid 2-perfluoroethyl ethyl, (meth) acrylic acid 2-perfluoroethyl-2-perfluorobutyl ethyl, (meth) acrylic acid (Meth) acrylic monomers such as 2-perfluoroethyl, perfluoromethyl (meth) acrylate, styrene monomers such as chlorostyrene, 2-vinylphenylstyrenesulfonic acid and its salts, perfluoroethylene, perfluoro Fluorine-containing vinyl monomers such as propylene and vinylidene fluoride, silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane, maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmale Maleimide monomers such as amide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide, nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl ( Amide group-containing vinyl monomers such as (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, vinyl chloride, chloride Examples include vinylidene and allyl chloride. The monomer (c) may be composed of only one kind or a mixture of two or more kinds.

  In addition, although the usage-amount of (c) at the time of copolymerizing (X) component may be arbitrary ratios, since the effect as a low-temperature fluidity improver is high, (a), (b) and (c) (C) is preferably 50 mol% or less, more preferably 30 mol% or less, still more preferably 10 mol% or less, and most preferably not used, based on the total amount. That is, it is preferable to use only (X1) as the component (X) of the present invention.

  In addition, the amount of (a) and (b) used in the copolymerization is highly effective as a low temperature fluidity improver, so that (a) / (b) = 10 / 90-90 / 10 (molar ratio) is preferable, (a) / (b) = 10 / 90-60 / 40 (molar ratio) is more preferable, (a) / (b) = 40 / 60-60 / 40 (Molar ratio) is more preferable.

  In order to polymerize the olefin as (a), maleic anhydride as (b), and (c) as appropriate, a known method may be used. For example, for maleic anhydride (b) Then, a random copolymer of olefin and maleic anhydride represented by the general formula (14) can be obtained by subjecting the olefin (a) and optionally (c) to a heat reaction at 40 to 250 ° C. for 2 to 30 hours. Although a catalyst may not be used, it is preferable to use a polymerization initiator such as azobisisobutyronitrile (AIBN) or benzoyl peroxide because the reaction yield is high. In addition, a chain transfer agent such as 1-decanethiol or carbon tetrachloride can be used for the purpose of adjusting the molecular weight of the polymer. Examples of the polymerization methods (a), (b) and (c) described above include a method in which (c) is polymerized using a known method to a copolymer obtained by polymerizing (a) and (b). Random polymerization or block polymerization may be used, but random polymerization is preferred because of easy production.

［式中、Ｒ^Ｅ、Ｒ^Ｆ、Ｒ^Ｇ及びＲ^Ｈは、モノマー（ｃ）成分由来の置換基を表し、ｌ１は１以上、好ましくは１〜２０の整数、ｍ１は１以上、好ましくは１〜２０の整数、ｎ１は０または１以上、好ましくは０又は１〜２０の整数、ｏ１は１以上、好ましくは２〜３００の整数を表す］

[Wherein, R ^E , R ^F , R ^G and R ^H represent a substituent derived from the monomer (c) component, l1 is 1 or more, preferably an integer of 1 to 20, m1 is 1 or more, preferably 1 An integer of ~ 20, n1 is 0 or 1 or more, preferably 0 or an integer of 1 to 20, and o1 is 1 or more, preferably an integer of 2 to 300]

The weight average molecular weight of the polymer that can be used as the component (X) can be controlled by adjusting the amount and type of the catalyst, the reaction temperature, the reaction time, and the like, and the molecular weight is not limited, but if the molecular weight is too low Since the effect as a low-temperature fluidity improver becomes low and the handling becomes difficult when the molecular weight is too high, or the case where it does not dissolve in the fatty acid methyl ester, 500 to 500,000 is preferable, 500 to 80000 is more preferable, and 5000 -80000 is more preferable, and 5000-40000 is most preferable. When adjusting the weight average molecular weight, the molecular weight can be increased by lowering the reaction temperature, and the molecular weight can be decreased by increasing the reaction temperature.
In addition, (X) component is comprised from the said 1 type, or 2 or more types of polymer.

   Next, the (Y) component will be described. The component (Y) is a copolymer (Y1) obtained by copolymerizing the monomer (d) represented by the general formula (3) and the monomer (e) represented by the general formula (4); and / or ( It is a homopolymer (Y2) obtained by polymerizing e). When the component (Y) is (Y1), a copolymer polymerized at an arbitrary ratio can be used. However, since the effect as a low-temperature fluidity improver is high, the monomer (d) / monomer (e) polymerization ratio is: (D) / (e) = 1/9 to 20/1 is preferable. The polymerization method (Y1) may be random, block, or random / block polymerization, but is preferably random polymerization because of easy production. Component (Y) may be a commercially available product or may be polymerized using a known method.

Incidentally, ^{R 5} in the general formula (4) is a hydrocarbon group of 1 to 40 carbon atoms, the hydrocarbon as a group formula number 1 to 40 carbon described above as ^{R 1} and ^{R 2} (1) that can be used A hydrocarbon group is mentioned. Among these, since the effect as a low-temperature fluidity improver is high, an alkyl group is preferable and the number of carbon atoms is preferably 1 to 22.

  Among the components (Y), since the effect as a low temperature fluidity improver is high, the monomer (f) represented by the general formula (5) or the monomer represented by the general formula (7) (3) h), the monomer (g) represented by the general formula (6) is represented by the general formula (6) or the monomer (i) represented by the general formula (8), and the component (Y) is (f) Copolymer (Y3) obtained by copolymerizing (g) and (g); homopolymer (Y5) obtained by polymerizing (g); copolymer (Y4) obtained by copolymerizing (h) and (i) And (g) are preferably homopolymers (Y6) obtained by polymerizing (Y3), (Y4) or (Y5).

PhCH = CH ₂ (5)
(Ph represents a phenyl group)

CH ₂ = CR ⁴ (C (═O) OR ⁶ ) (6)
(Wherein R ⁴ represents a hydrogen atom or a methyl group, and R ⁶ represents a hydrocarbon group having 1 to 40 carbon atoms)

CH ₂ = CH ₂ (7)

_{CH 2 = CHOC (= O)} Me (8)
(In the formula, Me represents a methyl group)

Details of (Y3) to (Y6) will be described below.
First, (Y3) will be described.
The amount used when copolymerizing (f) and (g) may be an arbitrary ratio, but (f) / (g) = 1/9 to 9/1 because the effect as a low-temperature fluidity improver is high. (Molar ratio) is preferable, 1/4 to 4/1 (molar ratio) is more preferable, and 1/4 to 2/1 (molar ratio) is still more preferable.

R ^{6 in the} general formula (6) is a hydrocarbon group having 1 to 40 carbon atoms, and usable hydrocarbon groups are the hydrocarbons having 1 to 40 carbon atoms described above as R ¹ and R ^{2 in} the general formula (1). Groups. Among these hydrocarbon groups, an alkyl group is preferred because of its high effect as a low temperature fluidity improver. 1-30 are preferable, as for carbon number, 1-22 are more preferable, and 4-18 are still more preferable. There is no restriction on the molecular weight, but if the molecular weight is too low, the effect as a low-temperature fluidity improver will be low, and if the molecular weight is too high, handling may be difficult or it may not dissolve in the fatty acid methyl ester. The average molecular weight is preferably 1000 to 600000, more preferably 2000 to 300000, further preferably 3000 to 200000, and most preferably 3000 to 150,000.

（式中、ｌ２は１以上、好ましくは１〜２０の整数、ｍ２は１以上、好ましくは１〜２０の整数及びｎ２は１以上、好ましくは３〜１００の整数を表す） (Y3) may be a commercially available product or may be polymerized using a known method. The polymerization method may be random or block polymerization, but random polymerization is preferred because of easy production.
For example, if styrene [monomer (f)], (meth) acrylic acid ester [monomer (g)] and AIBN as a polymerization initiator are subjected to a polymerization reaction, styrene- ( A (meth) acrylate copolymer is obtained:

(Wherein l2 is 1 or more, preferably an integer of 1-20, m2 is 1 or more, preferably 1-20, and n2 is 1 or more, preferably 3-100)

Next, (Y4) will be described.
The amount used when copolymerizing (h) and (i) may be an arbitrary ratio, but (h) / (i) = 1/9 to 20/1 because the effect as a low temperature fluidity improver is high. Is preferable, 1/4 to 15/1 is more preferable, 1/2 to 15/1 is still more preferable, and 4/5 to 9/1 is most preferable.

  There is no restriction on the molecular weight, but if the molecular weight is too low, the effect as a low-temperature fluidity improver will be low, and if the molecular weight is too high, handling may be difficult or it may not dissolve in the fatty acid methyl ester. The average molecular weight is preferably 1000 to 600000, more preferably 2000 to 300000, and still more preferably 3000 to 100000. The polymerization method of (Y4) may be random or block polymerization, but random polymerization is preferred because of easy production. For example, an ethylene-vinyl acetate copolymer represented by the general formula (16) can be obtained by performing a polymerization reaction using ethylene (h), vinyl acetate (i) and AIBN as a polymerization initiator:

（式中、ｌ３は１以上、好ましくは１〜２０の整数、ｍ３は１以上、好ましくは１〜２０の整数及びｎ３は１以上、好ましくは１０〜１０００の整数を表す）

(Wherein l3 is 1 or more, preferably an integer of 1-20, m3 is 1 or more, preferably 1-20, and n3 is 1 or more, preferably 10-1000)

Next, (Y5) will be described.
The preferred range for the carbon number of R ^{6 in} (Y5) is the same as in (Y3). There is no restriction on the molecular weight, but if the molecular weight is too low, the effect as a low-temperature fluidity improver will be low, and if the molecular weight is too high, handling may be difficult or it may not dissolve in the fatty acid methyl ester. The average molecular weight is preferably 1000 to 600000, more preferably 2000 to 400000, further preferably 3000 to 200000, and most preferably 3000 to 100,000. (Y5) may be a commercially available product or may be polymerized using a known method. For example, a (meth) acrylic acid ester homopolymer represented by the general formula (17) is obtained by radical polymerization using (meth) acrylic acid ester (g) and AIBN as a polymerization initiator:

（式中、ｌ４は２〜６０００、好ましくは１０〜３００の整数を表す。）

(In the formula, l4 represents an integer of 2 to 6000, preferably 10 to 300.)

Next, (Y6) will be described.
There is no restriction on the molecular weight, but if the molecular weight is too low, the effect as a low-temperature fluidity improver will be low, and if the molecular weight is too high, handling may be difficult or it may not dissolve in the fatty acid methyl ester. The average molecular weight is preferably 1000 to 600000, more preferably 2000 to 300000, further preferably 3000 to 150,000, and most preferably 3000 to 100,000. (Y6) may be a commercially available product or may be polymerized using a known method. For example, a vinyl acetate homopolymer represented by the general formula (18) is obtained by radical polymerization using vinyl acetate and AIBN as a polymerization initiator:

（式中、ｌ５は２以上、好ましくは１０〜１０００の整数を表す）

(In the formula, l5 represents 2 or more, preferably an integer of 10 to 1000)

  (Y) component is comprised from 1 type, or 2 or more types of polymers selected from the group which consists of the said copolymer and homopolymer. For example, you may select from (Y3), (Y4), (Y5) or (Y6), and may add 2 or more types.

  The ratio of the component (X) to the component (Y) can be used at an arbitrary ratio, but since the effect as a low-temperature fluidity improver is high, (X) / (Y) = 10/90 to 90/10 ( (Mass ratio) is preferable, (X) / (Y) = 10/90 to 75/25 (mass ratio) is more preferable, and (X) / (Y) = 10/90 to 60/40 (mass ratio) is further. (X) / (Y) = 40/60 to 60/40 (mass ratio) is most preferable.

  The predicate “biodiesel fuel” described in the present specification is a fuel containing 100% by mass of fatty acid methyl ester or light oil and fatty acid methyl ester. As light oil, No. 1 light oil standardized in JIS K2204 Any general diesel oil that can be used in diesel engines such as No. 2, No. 2 diesel oil and No. 3 diesel oil can be used.

  In addition, as fatty acid methyl esters, those using natural fats and oils obtained from plants as raw materials, those using natural fats and oils obtained from animals, and those using these waste cooking oils as raw materials are all used. be able to. Examples of plant-based natural fats and oils include, for example, linseed oil, eno oil, boar deer oil, olive oil, cacao butter, kapok oil, white mustard oil, sesame oil, rice bran oil, safflower oil, shea nut oil, cinnakiri oil, soybean oil, tea Seed oil, camellia oil, corn oil, rapeseed oil, palm oil, palm kernel oil, castor oil, sunflower oil, cottonseed oil, coconut oil, tree wax, peanut oil, Jatropha oil, sand peach oil, flower bud oil and mixtures thereof Examples of animal fats include beef tallow and pork tallow. The fatty acid methyl ester may be produced by any known method, for example, by heating the above natural oil and methanol under an alkali catalyst such as sodium hydroxide or potassium hydroxide. Examples include a method obtained by transesterification to remove glycerin that is produced as an impurity.

  When blending light oil and fatty acid methyl ester, it is preferable to blend so that fatty acid methyl ester is 2% by mass or more based on the total amount of biodiesel fuel. If the fatty acid methyl ester is less than 2% by mass, it is insufficient to achieve the original purpose of biodiesel fuel, which is to reduce the amount of fossil fuel used and reduce carbon dioxide emissions. Since the significance may be lost, it is not preferable.

  The biodiesel fuel composition of the present invention comprises the above biodiesel fuel and the low-temperature fluidity improver for fatty acid methyl esters of the present invention. The blending amount of the low temperature fluidity improver of the present invention with respect to the biodiesel fuel is not particularly limited, but is preferably 0.001 to 5% by mass based on the total amount of the biodiesel fuel, 0.001 to 2 % By mass is more preferred, 0.005 to 2% by mass is still more preferred, and 0.01 to 1.5% by mass is most preferred. If the blending amount is less than 0.001% by mass, a sufficient effect may not appear, and if it exceeds 5% by mass, an effect commensurate with the blending amount may not be obtained, or depending on the type of biodiesel fuel This is not preferable because insoluble matter may be generated.

  In the biodiesel fuel composition of the present invention, a cetane number improver can be blended as necessary. As the cetane improver, various compounds known as cetane improvers for light oils can be arbitrarily used. For example, 2-chloroethyl nitrate, 2-ethoxyethyl nitrate, isopropyl nitrate, butylnite. Rate, primary amyl nitrate, secondary amyl nitrate, isoamyl nitrate, primary hexyl nitrate, secondary hexyl nitrate, n-heptyl nitrate, n-octyl nitrate, 2-ethylhexyl nitrate, cyclohexyl night Examples thereof include ethylene glycol dinitrate and the like, and alkyl nitrates having 6 to 8 carbon atoms are particularly preferable. The content of the cetane number improver is in the range of 500 to 1400 mass ppm, preferably 600 to 1250 mass ppm, and more preferably 700 to 1100 mass ppm with respect to the total amount of the biodiesel fuel composition. When the cetane number improver is blended, if the blending amount is less than 500 ppm by mass, a sufficient cetane number improving effect cannot be obtained, and particulate matter (PM), aldehydes in diesel engine exhaust gas, and further This is not preferable because NOx may not be sufficiently reduced. Moreover, even if the compounding quantity of a cetane number improvement agent exceeds 1400 mass ppm, the effect corresponding to it cannot be expected but it may become economically disadvantageous.

  Moreover, a detergent can be mix | blended with the biodiesel fuel composition of this invention as needed. Examples of the detergent include imide compounds; alkenyl succinimides such as polybutenyl succinimides synthesized from polybutenyl succinic anhydrides and ethylene polyamines; polyhydric alcohols such as pentaerythritol and polybutyls. Succinic acid esters such as polybutenyl succinic acid ester synthesized from tenyl succinic anhydride; copolymer polymers such as dialkylaminoethyl methacrylate, polyethylene glycol methacrylate, vinyl pyrrolidone and alkyl methacrylate copolymers, carboxylic acids and amines Ashless detergents such as reaction products of alkenyl succinic acid imide and reaction products of carboxylic acid and amine are preferred. These detergents can be used alone or in combination of two or more. The blending amount of the detergent is not particularly limited, but in order to bring out the effect of blending the detergent, specifically, the effect of suppressing clogging of the fuel injection nozzle, the blending amount of the detergent is the biodiesel fuel composition. It is in the range of 30 to 300 mass ppm, preferably 60 to 200 mass ppm with respect to the total amount of the object. When the blending amount of the detergent is less than 30 ppm by mass, the above-mentioned effect may not appear, and even if it exceeds 300 ppm by mass, an effect commensurate with it cannot be expected. Conversely, NOx in diesel engine exhaust gas , PM, aldehydes, etc. may be increased.

  Furthermore, other known fuel oil additives can be added to the biodiesel fuel composition of the present invention alone or in combination of several kinds for the purpose of further enhancing the performance. Other additives include, for example, alcohols such as methanol, ethanol, propanol and butanol, amines such as triethanolamine and alkyldiethanolamine, hydrocarbon solvents such as hexane, toluene, trimethylbenzene and mineral oil; alkyl metal esters, Esters such as polyhydric alcohol esters, antioxidants such as phenols, amines and vitamins; lubricity improvers such as fatty acids, glycerin esters, alkylamines and fatty acid amides; metal deactivators such as salicylidene derivatives; Anti-icing agents such as polyglycol ethers; corrosion inhibitors such as aliphatic amines and alkenyl succinic acid esters; antistatic agents such as anionic, cationic and amphoteric surfactants; colorants such as azo dyes; Defoaming agent, methanol, etc. Draining agents such as 2-propanol. The blending amount of other additives can be arbitrarily determined, but the blending amount of each additive is 0.001 to 0.5% by mass, more preferably 0.001 with respect to the total amount of the biodiesel fuel composition. It is in the range of -0.2% by mass.

Hereinafter, the present invention will be specifically described by way of examples. In the following examples and the like, “%” and “ppm” are based on mass unless otherwise specified, Mw represents a weight average molecular weight, and all blending ratios are mass ratios.
<Polymerization method of components (X) and (Y)>
A-1 was synthesized by the following method.
In a 1000 ml flask equipped with a nitrogen inlet tube, a reflux tube, a nitrogen blowing tube equipped with a stirrer and a thermometer and a condenser, 1-octadecene 0.25 mol (63 g), maleic anhydride 0.25 mol (25 g), methyl ethyl ketone 350 g, AIBN 0.01 mol (0.3 g) was charged, heated to 70 ° C., and reacted at the same temperature for 5 hours to complete the reaction. The solvent was distilled off from the resulting reaction product under reduced pressure to obtain 88 g of a random copolymer of 1-octadecene and maleic anhydride.

A-2 and A-3 were synthesized by changing the charging ratio of the monomer A-1 and reacting in the same manner as A-1.
A-4 was synthesized by using 1-dodecene instead of 1-octadecene and reacting in the same manner as A-1.
A-5 was synthesized by reacting in the same manner as A-1, using propene instead of 1-octadecene.
A-6 was synthesized by using 1-tricosene instead of 1-octadecene and reacting in the same manner as A-1.
A-7 was synthesized by using vinyl acetate instead of 1-octadecene and reacting in the same manner as A-1.
A-8 was synthesized by using dodecyl acrylate instead of 1-octadecene and reacting in the same manner as A-1.
A-9 was synthesized by using styrene instead of 1-octadecene and reacting in the same manner as A-1.
A-10 was synthesized by reacting in the same manner as in A-1, using the same raw materials as in A-1 and methyl methacrylate.
A-11 to A-13 were synthesized using the same raw materials as A-1, adjusting the reaction temperature.

B-1 was synthesized by the following method.
Ethylene 0.5 mol (14 g), vinyl acetate 0.5 mol (43 g), and hexane 230 g were added to a 1000 ml flask equipped with a nitrogen inlet tube, a reflux tube, a nitrogen blowing tube equipped with a stirrer and a thermometer, and a condenser. And dissolved with stirring. Subsequently, this was allowed to stand at −20 ° C. for 4 hours, and then centrifuged at −20 ° C. (10000 rpm × 30 minutes) to isolate insoluble matter. The solvent was distilled off from the obtained reaction product under reduced pressure to obtain 57 g of the desired product.

B-6 and B-8 were synthesized by changing the charging ratio of the monomer B-1 and reacting in the same manner as B-1.
B-7 and B-9 were synthesized using the same raw materials as B-6, adjusting the reaction temperature.

B-2 was synthesized by the following method.
A 1000 ml flask equipped with a nitrogen inlet tube, a reflux tube, a nitrogen blowing tube equipped with a stirrer and a thermometer and a condenser was charged with 0.5 mol (127 g) of dodecyl methacrylate, 350 g of methyl ethyl ketone and 0.01 mol (0.3 g) of AIBN, The mixture was stirred at 70 ° C. for 5 hours to complete the reaction. The solvent was distilled off from the resulting reaction product under reduced pressure to obtain 127 g of the desired product.

B-3 was synthesized by reacting in the same manner as B-2, using dodecyl acrylate instead of dodecyl methacrylate.
B-10 and B-11 were synthesized using the same raw materials as B-2, adjusting the reaction temperature.
B-12 was synthesized by reacting butyl methacrylate in place of dodecyl methacrylate in the same manner as B-2.
B-13 was synthesized by reacting octadecyl methacrylate instead of dodecyl methacrylate in the same manner as B-2.

B-4 was synthesized by the following method.
In a 1000 ml flask equipped with a nitrogen inlet tube, a reflux tube, a nitrogen blowing tube equipped with a stirrer and a thermometer and a condenser, 0.25 mol (26 g) of styrene, 0.25 mol (64 g) of dodecyl methacrylate, 350 g of methyl ethyl ketone, azobis Isobutyronitrile 0.01 mol (0.3 g) was charged, heated to 70 ° C., and reacted at the same temperature for 5 hours to complete the reaction. The solvent was distilled off from the resulting reaction product under reduced pressure to obtain 90 g of the desired product.

B-5 was synthesized by reacting butyl methacrylate in place of dodecyl methacrylate in the same manner as B-4.
B-14 and B-15 were synthesized using the same raw materials as B-4, adjusting the reaction temperature.
B-16 was synthesized by reacting octadecyl methacrylate instead of dodecyl methacrylate in the same manner as B-4.
B-17 was synthesized by reacting in the same manner as B-4, changing the charge ratio of the monomer B-4.
B-18 was synthesized by reacting in the same manner as B-4 using dodecyl acrylate instead of dodecyl methacrylate.

<Measurement method of weight average molecular weight>
The weight average molecular weight was calculated by GPC. The equipment and measurement conditions used for the measurement are as follows.
Detector: RI detector HLC-8120GPC [Tosoh Corporation]
Column: TSKgel G4000Hxl, TSKgel G3000Hxl, TSKgel
G2000Hxl [both Tosoh Corporation] connected in series Solvent: THF (tetrahydrofuran)
Developing solvent flow rate: 1 ml / min Sample concentration: 0.5% by mass
Measurement temperature: 40 ° C

<Pour point test>
Base oil 1 (100% soybean oil-derived fatty acid methyl ester), base oil 2 (light oil containing 5% soybean oil-derived fatty acid methyl ester), and base oil with the low-temperature fluidity improvers shown in Tables 1-7 3 (100% rapeseed oil-derived fatty acid methyl ester) was used to prepare a biodiesel fuel composition, and measurement was performed by the method described in JIS K2269 “Pour point of crude oil and petroleum products and cloud point test for petroleum products”. . That is, a 45 ml sample (biodiesel fuel composition) is placed in a test tube and heated to 45 ° C., and then the sample is cooled using a cooling bath. Each time the temperature of the sample drops 2.5 ° C, the test tube is removed from the cooling bath and tilted. The temperature when the sample stops moving for 5 seconds is read, and the value obtained by adding 2.5 ° C to this value is the pour point. It was. The light oil used in the experiment corresponds to No. 1 light oil standardized in JIS K2204. Results 1 tested using base oil 1, results 2 tested using base oil 2, and results 3 tested using base oil 3 are listed in Tables 1-7.

<CFPP test>
Similarly to the pour point test, a biodiesel fuel composition was prepared by using the base oil 1 (100% soybean oil-derived fatty acid methyl ester) with the above-described low-temperature fluidity improvers shown in Tables 1 to 7, and JIS The measurement was carried out in accordance with the method described in K2288 “Light oil—clogging point test method”. That is, a 45 ml sample is taken into a test tube and cooled. Each time the temperature of the sample decreased by 1 ° C., the sample was sucked through a filter with a wire mesh having a mesh opening of 45 μm under a reduced pressure of 2 kPa (water column 200 mm), and the time required for 20 ml of the sample to pass through the filter with a wire mesh was measured.
Thus, the temperature when the filtration passage time of a sample exceeded 60 seconds was read, and it was set as the clogging point, and it described in Tables 1-7 as the result 4.

<Test sample>
The component (X) used in the test is the following polymer (the following all represent molar ratios).
A-1: (a) (in the general formula ^{(1), R} 1 = hexadecyl, ^{R 2} = hydrogen atom) obtained by copolymerizing a / (b) = 50/50 copolymer (Mw = 9800)
A-2: (a) (copolymer obtained by copolymerizing R ¹ = hexadecyl group, R ² = hydrogen atom) / (b) = 75/25 in the general formula (1) (Mw = 12000)
A-3: Copolymer obtained by copolymerizing (a) (in the general formula (1), R ¹ = hexadecyl group, R ² = hydrogen atom) / (b) = 25/75 (Mw = 7200)
A-4: Copolymer obtained by copolymerizing (a) (in formula (1), R ¹ = decyl group, R ² = hydrogen atom) / (b) = 50/50 (Mw = 7500)
A-5: Copolymer obtained by copolymerizing (a) (in formula (1), R ¹ = methyl group, R ² = hydrogen atom) / (b) = 50/50 (Mw = 3900)
A-6: Copolymer (Mw = 12000) obtained by copolymerizing (a) (in the general formula (1), R ¹ = henicosyl group, R ² = hydrogen atom) / (b) = 50/50
A-7: Copolymer (Mw) obtained by copolymerizing (a) (in the general formula (1), R ¹ = —OC (═O) Me, R ² = hydrogen atom) / (b) = 50/50 = 5200)
A-8: obtained by copolymerizing (a) (in the general formula (1), R ¹ = —C (═O) OC ₁₂ H ₂₅ , R ² = hydrogen atom) / (b) = 50/50 Copolymer (Mw = 950 0)
A-9: Copolymer obtained by copolymerizing (a) (in general formula (1), R ¹ = phenyl group, R ² = hydrogen atom) / (b) = 50/50 (Mw = 6100)
A-10: (a) (in general formula (1), R ¹ = hexadecyl group, R ² = hydrogen atom) / (b) / (g) (in general formula (6), R ⁴ = methyl group, R ⁶ = methyl group) = 45/45/10 copolymerized to obtain a copolymer (Mw = 9800)
A-11: (a) (in general formula (1), R ¹ = hexadecyl group, R ² = hydrogen atom) / copolymer obtained by copolymerizing (b) = 50/50 (Mw = 3200)
A-12: (a) (in general formula (1), R ¹ = hexadecyl group, R ² = hydrogen atom) / copolymer obtained by copolymerizing (b) = 50/50 (Mw = 48000)
A-13: (a) (in general formula (1), R ¹ = hexadecyl group, R ² = hydrogen atom) / copolymer obtained by copolymerizing (b) = 50/50 (Mw = 98000)

The component (Y) used in the test is the following polymer (the following all represent molar ratios).
B-1: Copolymer obtained by copolymerizing (h) / (i) = 50/50 (Mw = 4500)
B-2: (g) (in general formula (6), R ⁴ = methyl group, R ⁶ = dodecyl group) obtained by polymerizing a homopolymer (Mw = 90000)
B-3: Homopolymer obtained by polymerizing (g) (in the general formula (6), R ⁴ = hydrogen atom, R ⁶ = dodecyl group) (Mw = 38000)
B-4: Copolymer obtained by copolymerizing (f) / (g) (in formula (6), R ⁴ = methyl group, R ⁶ = dodecyl group) = 50/50 (Mw = 66000)
B-5: Copolymer obtained by copolymerizing (f) / (g) (in formula (6), R ⁴ = methyl group, R ⁶ = butyl group) = 50/50 (Mw = 47000)
B-6: Copolymer obtained by copolymerizing (h) / (i) = 90/10 (Mw = 4000)
B-7: Copolymer obtained by copolymerizing (h) / (i) = 90/10 (Mw = 980000)
B-8: Copolymer obtained by copolymerizing (h) / (i) = 25/75 (Mw = 4800)
B-9: Copolymer obtained by copolymerizing (h) / (i) = 90/10 (Mw = 1000)
B-10: (g) (Homopolymer Mw = 3000 obtained by polymerizing R ⁴ = methyl group, R ⁶ = dodecyl group in general formula (6))
B-11: (g) (in general formula (6), R ⁴ = methyl group, R ⁶ = dodecyl group) obtained by polymerizing a homopolymer (Mw = 100000)
B-12: (g) (Mw = 40000) obtained by polymerizing (g) (in formula (6), R ⁴ = methyl group, R ⁶ = butyl group)
B-13: (g) (in general formula (6), R ⁴ = methyl group, R ⁶ = octadecyl group) obtained by polymerizing a homopolymer (Mw = 30000)
B-14: Copolymer obtained by copolymerizing (f) / (g) (in formula (6), R ⁴ = methyl group, R ⁶ = dodecyl group) = 50/50 (Mw = 3200)
B-15: a copolymer obtained by copolymerizing (f) / (g) (in formula (6), R ⁴ = methyl group, R ⁶ = dodecyl group) = 50/50 (Mw = 200000)
B-16: Copolymer obtained by copolymerizing (f) / (g) (in formula (6), R ⁴ = methyl group, R ⁶ = octadecyl group) = 50/50 (Mw = 32000)
B-17: a copolymer obtained by copolymerizing (f) / (g) (in formula (6), R ⁴ = methyl group, R ⁶ = dodecyl group) = 20/80 (Mw = 28000)
B-18: Copolymer obtained by copolymerizing (f) / (g) (in formula (6), R ⁴ = hydrogen atom, R ⁶ = dodecyl group) = 50/50 (Mw = 45000)
B-19: Homopolymer obtained by polymerizing (i) (Aldrich, reagent code: 189480) (Mw = 100000)

The other components other than the (X) component and the (Y) component are as follows.
C-1: A commercially available polypropylene was used (manufactured by Aldrich, reagent code: 45214 9) (Mw = 174000).
C-2: Commercially available polystyrene was used (manufactured by Fluka, reagent code: 81407) (Mw = 20000).
C-3: Commercially available poly (sodium acrylate) was used (manufactured by Fluka, reagent code: 8 1123) (Mw = 16000).
The test results are shown below (all blending ratios are mass ratios).

Claims (8)

A low-temperature fluidity improver for fatty acid methyl esters comprising the following (X) component and (Y) component,
(X) copolymer (X1) obtained by copolymerizing monomer (a) represented by general formula (1) and monomer (b) represented by general formula (2); and / or monomer A copolymer (X2) obtained by copolymerizing (a), a monomer (b), and a monomer (c) having a carbon-carbon double bond other than the monomer (a) and the monomer (b);
(Y) copolymer (Y1) obtained by copolymerizing monomer (d) represented by general formula (3) and monomer (e) represented by general formula (4); and / or ( A low temperature fluidity improver for fatty acid methyl esters, characterized in that it is a homopolymer (Y2) obtained by polymerizing e):
R ¹ CH═CHR ² (1)
(In the formula, ^{R 1} and ^{R 2} are each independently oxygen atom, -C (= O) -, - C (= O) O -, - OC (= O) - or -OC (= O) O-in Represents a hydrocarbon group having 1 to 100 carbon atoms which may be interrupted, or a hydrogen atom)

R ³ CH═CH ₂ (3)
(R ³ represents a hydrogen atom or a phenyl group)
CH ₂ = CR ⁴ (LR ⁵ ) (4)
(In the formula, R ⁴ represents a hydrogen atom or a methyl group, L represents —C (═O) O— or —OC (═O) —, and R ⁵ represents a hydrocarbon group having 1 to 40 carbon atoms. .)   The low-temperature fluidity improver for fatty acid methyl esters according to claim 1, wherein the amount of (c) used relative to the total amount of (a), (b) and (c) is 50 mol% or less.   The low-temperature fluidity improver for fatty acid methyl esters according to claim 1, wherein the component (X) is (X1).   4. The fatty acid methyl ester according to claim 1, wherein the ratio of (a) and (b) is (a) / (b) = 10/90 to 90/10 (molar ratio). Low temperature fluidity improver.   The fatty acid methyl ester according to any one of claims 1 to 4, wherein the ratio of the component (X) to the component (Y) is (X) / (Y) = 10/90 to 90/10 (mass ratio). Low temperature fluidity improver. The general formula (3) is the monomer (f) represented by the general formula (5) or the monomer (h) represented by the general formula (7), and the general formula (4) is represented by the general formula (6). Monomer (g) or monomer (i) represented by formula (8), wherein (Y) component is a copolymer (Y3) obtained by copolymerizing (f) and (g); (g Homopolymer (Y5) obtained by polymerizing ()); copolymer (Y4) obtained by copolymerizing (h) and (i); and homopolymer (Y6) obtained by polymerizing (g) The low-temperature fluidity improver for fatty acid methyl esters according to any one of claims 1 to 5, comprising a component (Y) consisting of one or more polymers selected from
PhCH = CH ₂ (5)
(Ph represents a phenyl group)
^{_{CH 2 = CR 4 (C (}} = O) OR 6) (6)
(Wherein R ⁴ represents a hydrogen atom or a methyl group, and R ⁶ represents a hydrocarbon group having 1 to 40 carbon atoms)
CH ₂ = CH ₂ (7)
_{CH 2 = CHOC (= O)} Me (8)
(In the formula, Me represents a methyl group)   A biodiesel fuel composition comprising the low-temperature fluidity improver for fatty acid methyl esters according to any one of claims 1 to 6 and biodiesel fuel.   Furthermore, cetane improvers, detergent solvents, hydrocarbon solvents, antioxidants, lubricity improvers, metal deactivators, anti-icing agents, corrosion inhibitors, antistatic agents, colorants, draining agents and defoamers The biodiesel fuel composition according to claim 7, comprising one or more other additives selected from the group consisting of agents.