JP2007009195A - Agent for increasing fluidity of fuel oil and fuel oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an additive which can improve the dispersibility of wax crystals in a fuel oil, particularly a low sulfur content fuel oil at a low temperature, so that fluidity of the fuel oil at a low temperature can be improved. <P>SOLUTION: The agent for improving fluidity of a fuel oil comprises (A) a copolymer of (a1) ethylene and (a2) a vinyl ester of a 2-24C aliphatic saturated carboxylic acid and (B) an oil soluble nitrogen-containing compound as the essential structural monomer moieties, wherein a hexane-insoluble content of (A) is less than 30 wt% or less at +10°C and 60 wt% or more at -20°C, and particularly, the copolymer (A) is preferably one comprising ethylene (a1), vinyl acetate and a vinyl ester of a 3-22C aliphatic saturated carboxylic acid as the essential constitutional monomers. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fluidity improver for fuel oil. Specifically, the present invention relates to a fluidity improver and a fuel oil composition for wax-containing fuel oil.

Petroleum middle distillates, such as diesel fuel oil and A heavy oil, when exposed to low temperatures (eg, 0 ° C. to −20 ° C.) in winter or in cold regions, the wax contained therein precipitates, and the piping system Problems occur due to clogging of the filter or solidification in the piping system. In order to solve these problems related to low-temperature fluidity, many methods for adding an ethylene-unsaturated carboxylic acid vinyl ester copolymer to a base oil have been proposed (see, for example, Patent Documents 1 to 3). . However, what is proposed in the above-mentioned patent document cannot be said that the precipitated crystals are sufficiently refined, and has the disadvantage that the wax crystals do not disperse in the oil and settle to the bottom.
As a fluidity improver that compensates for these drawbacks, a method using an amide / amine salt of an aromatic dicarboxylic acid has been proposed. (For example, see Patent Documents 6 and 7) In addition, a method of using an amide / amine salt of an aromatic dicarboxylic acid in combination with an ethylene-vinyl acetate copolymer or an ethylene-propylene copolymer has been proposed. (For example, see Patent Documents 8 to 10)
Japanese Patent Laid-Open No. 39-200692 Japanese Patent Publication No. 48-23165 JP 59-136391 A Japanese Patent Publication No. 58-39472 Japanese Patent Laid-Open No. 10-245574 JP-A-49-53902 JP-A-62-587 JP-A-56-92996 JP 58-1792 A JP 63-165487 A

However, even in the method using the amide / amine salt of the aromatic dicarboxylic acid, the low temperature fluidity has not been sufficiently improved.
On the other hand, in recent years, fuel oil has been promoted to reduce sulfur due to the problem of the influence of exhaust gas on the environment. Along with this, many so-called narrow cut fuel oils have been produced, in which heavy fractions containing sulfur components that are difficult to remove are cut from the fuel oil. It has been more difficult to improve the low temperature fluidity than these fuel oils compared to conventional fuel oils. For example, even the method using the amide / amine salt of the aromatic dicarboxylic acid has drawbacks such as insufficient refinement of precipitated crystals and precipitation of wax crystals, resulting in a fuel suction port to the fuel pump. Since the oil is coming out from the bottom of the fuel tank, if the wax crystal settles, the amount of wax sucked at the time of the initial pump operation increases significantly, often leading to an engine stop at the initial time.
An object of the present invention is to provide an additive capable of improving the dispersibility of wax crystals at a low temperature of a fuel oil, particularly a fuel oil having a low sulfur content, and improving the low temperature fluidity.

  As a result of intensive studies, the present inventors have found a fluidity improver that can solve the above-mentioned problems and have reached the present invention. That is, the present invention relates to a copolymer (A) comprising ethylene (a1) and a vinyl ester (a2) of an aliphatic saturated carboxylic acid having 2 to 24 carbon atoms as essential constituent monomers, and an oil-soluble nitrogen-containing compound (B And a fluidity improver for fuel oil, wherein the hexane insoluble content at + 10 ° C. of (A) is 30% by weight or less and the hexane insoluble content at −20 ° C. is 60% by weight or more; And a fluidity improver composition for fuel oil containing other additives and / or diluent (S); and a fuel oil composition containing the fluidity improver and fuel oil.

  The fluidity improver of the present invention improves the dispersibility of the wax crystals at low temperatures of the fuel oil compared to conventional ones, is excellent in the effect of improving the low temperature fluidity, and is added with a small amount of CFPP (low temperature filter). Clogging point) and PP (pour point) can be lowered. In particular, the conventional fluidity improver is effective for low-sulfur light gas oil having a low cloud point and A heavy oil, which have been difficult to improve low-temperature fluidity.

In the present invention, the polymer (A) which is an essential component [hereinafter, “polymer” represents a homopolymer and / or a copolymer] has a hexane insoluble content at a specific temperature within a specific range. It is important to be. (A) is usually 30% or less at + 10 ° C. (Unless otherwise specified,% represents% by weight), preferably 25% or less, more preferably 20% or less, particularly preferably 15% or less, especially Preferably it has a hexane insoluble content of 10% or less. When the hexane insoluble content at + 10 ° C. exceeds 30%, it is necessary to add a large amount of a fluidity improver in order to develop sufficient low temperature fluidity. Further, (A) has a hexane insoluble content of usually 60% or more, preferably 65% or more, more preferably 70% or more, and particularly preferably 75% or more at -20 ° C. If the hexane insoluble content at −20 ° C. is less than 60%, it is necessary to add a large amount of fluidity improver in order to develop sufficient low temperature fluidity. Further, the difference between the hexane insoluble content at + 10 ° C. and the hexane insoluble content at −20 ° C. of (A) is usually 30% or more, preferably 45% or more, more preferably 50% or more, particularly preferably 55% or more, Preferably it is 60% or more. The larger this difference, the better in that the low temperature fluidity can be improved by adding a small amount of fluidity improver. Further, (A) has a hexane-insoluble content at 0 ° C. of preferably 50% or less, more preferably 35% or less, particularly preferably 30% or less, and particularly preferably 25% or less. If the hexane insoluble content at 0 ° C. is within the above range, the low temperature fluidity of the fuel oil composition is improved by the addition of a small amount of fluidity improver.
The hexane insoluble matter at + 10 ° C. and −20 ° C. can be measured by the following method.
First, 100 g of a sample is taken in a 500 ml beaker, and this is dried under reduced pressure at 150 ° C. and 10 mmHg for 2 hours to evaporate volatile components. About 30 g of this is precisely weighed (weight is (W) [g]), and n-hexane is added so that the polymer concentration becomes 20% to prepare an n-hexane solution (heated if necessary). Dissolve until uniform and transparent). This is put into a 400 ml centrifuge tube and left in a + 10 ° C. constant temperature bath for 4 hours. This is centrifuged at 10,000 rpm for 30 minutes in a centrifuge controlled at + 10 ° C., and then insoluble and soluble components are decanted and separated. The insoluble matter in the centrifuge tube is dried under reduced pressure at 120 ° C. and 10 mmHg for 2 hours to evaporate the residual hexane. From the weight (Wi) [g] of the residue, the hexane insoluble matter (Wi / W) at + 10 ° C. × 100 [ %] Is calculated. On the other hand, the solution separated as a hexane-soluble component at + 10 ° C. is again placed in a centrifuge tube and left in a thermostatic bath at −20 ° C. for 4 hours. This is centrifuged in the same manner as described above with a centrifuge temperature-controlled at −20 ° C. to separate insoluble and soluble components. The obtained soluble matter is concentrated with a vacuum evaporator and then dried under reduced pressure under the same conditions as described above. From its weight (Ws) [g], hexane insoluble matter at −20 ° C. {100− (Ws / W) × 100 } Calculate [%]. Further, the hexane insoluble matter at 0 ° C. can be measured in the same manner as the measurement of the hexane insoluble matter at + 10 ° C. except that the standing temperature and the temperature of the centrifuge are set to 0 ° C.

The copolymer (A) preferably comprises 70 to 95 mol%, more preferably 80 to 90 mol%, particularly preferably 81 to 88 mol%, particularly preferably 82 to 87 mol% of ethylene (a1) as a structural unit. It is preferable that it is easily contained within the specified range of the hexane insoluble matter in the present invention and the low temperature fluidity is improved.
Further, (A) preferably has 30 to 85% by weight, more preferably 50 to 75% by weight, and particularly preferably 52 to 68% by weight of ethylene (a1) as a structural unit, which improves low temperature fluidity. This is preferable.

As the vinyl ester (a2) of an aliphatic saturated carboxylic acid having 2 to 24 carbon atoms which is an essential constituent monomer of (A), a primary aliphatic saturated carboxylic acid [linear aliphatic saturated carboxylic acid (acetic acid, n -Propionic acid, n-hexanoic acid, n-decanoic acid, n-dodecanoic acid, palmitic acid, stearic acid, behenic acid, etc.)], branched secondary aliphatic saturated carboxylic acids (such as 2-ethylhexanoic acid), and branched Examples include vinyl esters of tertiary aliphatic saturated carboxylic acids (neononanoic acid, neodecanoic acid, neododecanoic acid, etc.).
Specific examples of (a2) include vinyl acetate, vinyl propionate, vinyl hexanoate, vinyl 2-ethylhexanoate, vinyl neodecanoate, vinyl decanoate, vinyl dodecanoate, vinyl palmitate and vinyl stearate. .
Of these, (a2) is preferably a combination of vinyl acetate and a vinyl ester of an aliphatic saturated carboxylic acid having 3 to 22 carbon atoms from the viewpoint of hexane-insoluble matter, and the proportion of vinyl acetate in the combined use is (a2) It is 50 mol% or more of the whole, Preferably it is 80 mol% or more.

(A) may contain another vinyl monomer (a3) in addition to (a1) and (a2) as a constituent monomer.
Examples of (a3) include the following monomers.
Aliphatic vinyl hydrocarbons such as propylene, butene, isobutylene and pentene; alicyclic vinyl hydrocarbons such as cyclohexene and (di) cyclopentadiene; styrene, α-methylstyrene, vinyltoluene and 2,4-dimethylstyrene Aromatic vinyl hydrocarbons of the following: carboxyl group-containing vinyl monomers such as (meth) acrylic acid, (anhydrous) maleic acid, maleic acid monoalkyl ester, fumaric acid and fumaric acid monoalkyl ester; hydroxystyrene, N-methylol ( Hydroxyl group-containing vinyl monomers such as meth) acrylamide and hydroxyethyl (meth) acrylate; aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate Amino group-containing vinyl monomers such as amide; amide group-containing vinyl monomers such as (meth) acrylamide and N-methyl (meth) acrylamide; nitrile group-containing vinyl monomers such as (meth) acrylonitrile and cyanostyrene; Alkyl (meth) acrylates having ˜50 alkyl groups; and vinyl monomers having a polyalkylene glycol chain; and the like.

  Preferred among (A) is a copolymer having ethylene (a1), vinyl acetate, and an aliphatic saturated carboxylic acid vinyl ester having 3 to 22 carbon atoms as essential constituent monomers from the viewpoint of hexane insoluble matter. .

  Specific examples of (A) include ethylene / vinyl acetate (molar ratio 84/16) copolymer, ethylene / vinyl acetate / vinyl neodecanoate (molar ratio 84/15/1) copolymer, ethylene / vinyl acetate / Examples thereof include vinyl 2-ethylhexanoate (molar ratio 83/15/2) copolymer and ethylene / vinyl acetate / 4-methylpentene-1 copolymer (molar ratio 82/16/2).

The degree of branching in (A) is usually 0.3 to 2.2%, preferably 0.3 to 2.1%, more preferably 0.4 to 2.0%, and particularly preferably 0.5 to 1. 8%.
If it is 0.3% or more, the solubility in the fuel oil is further improved, so that the oil permeability is easily improved, and if it is 2.2% or less, the low-temperature fluidity can be further improved.
The degree of branching in the present invention can be determined by ¹ H-NMR. For example, in the case of a copolymer of ethylene and vinyl acetate, a peak intensity [1] of 0.8 to 0.9 ppm (derived from a branched methyl group) and a peak intensity [2] of 1.0 to 1.9 ppm (ethylene and From vinyl methylene of vinyl acetate), peak intensity around 2.0 ppm [3] (derived from acetylmethyl group of vinyl acetate) and peak intensity [4] from 4.7 to 5.0 ppm (derived from vinyl methine of vinyl acetate) It can be calculated by the following formula.
Degree of branching (%) = [1] / 3 ÷ {([2]-[1] / 3) / 2 + [1] / 3 + [4]} × 100
When fatty acid vinyl other than vinyl acetate is contained, the peak derived from the fatty acid group may overlap with [1] and [2]. In that case, the peak intensity [5] (2.0 to 2.3 ppm) of the proton bonded to the carbon adjacent to the carbonyl group of the fatty acid group and the peak intensity [4] (4.7 to 5.0 ppm) of the fatty acid group The content of fatty acid vinyl can be determined from the vinyl ratio derived from vinyl methine, and the molar ratio can be calculated by subtracting the absorption of fatty acid groups overlapping [1] and [2]. When 1-olefin other than ethylene is contained, it is difficult to distinguish 1-olefin from branching by ¹ H-NMR, so the copolymerization ratio of 1-olefin is calculated from the charged amount and the reaction rate at the time of polymerization. The molar ratio can be calculated by subtracting the absorption of the 1-olefin side chain overlapping with [1] and [2].

The weight average molecular weight (hereinafter abbreviated as Mw) of (A) is preferably 3,000 to 50,000, more preferably 4,000 to 30,000, particularly preferably 5,000 to 20,000. is there. By setting it to 3,000 or more, the low-temperature fluidity is further improved, and by setting it to 50,000 or less, the solubility in the base oil is further improved.
The number average molecular weight (hereinafter abbreviated as Mn) of (A) is preferably 1,000 to 30,000, more preferably 2,000 to 20,000, and particularly preferably 2,500 to 10,000. is there. By setting it to 1,000 or more, the low-temperature fluidity is further improved, and by setting it to 30,000 or less, the solubility in base oil is further improved. In the present invention, Mn and Mw are measured values by gel permeation chromatography and are molecular weights measured in terms of polystyrene.

The copolymer (A) of the present invention can be obtained by a known method. For example, it can be obtained by radical polymerization of the vinyl monomers in a solvent or without a solvent. In this case, as the polymerization initiator, azo initiators (for example, azobisisobutyronitrile, azobisvaleronitrile, etc.) and peroxide initiators (for example, diisopropyl percarbonate, benzoyl peroxide, cumyl peroxide) Lauryl peroxide, di-t-butyl peroxide, etc.) can be used. Solvents include aliphatic hydrocarbons (hexane, heptane, octane, cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, ethylbenzene, C9 aromatic mixed solvents (mixtures of trimethylbenzene, ethyltoluene, etc.), carbon -10 to 11 aromatic mixed solvents etc.], ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) and the like. These polymerization solvents can be distilled off after completion of the polymerization, but the polymer (A) can be used as a solution as it is. In order to reduce the degree of branching, it is effective to lower the polymerization temperature (usually 30 to 200 ° C., preferably 30 to 160 ° C.) and use a chain transfer agent in combination. As chain transfer agents, known mercaptans (such as butyl mercaptan and lauryl mercaptan), secondary alcohols (such as isopropyl alcohol and sec-butanol), aromatic compounds (such as toluene, xylene, cumene) and aldehydes (such as propionaldehyde) Etc. can be used.
In the present invention, (A) does not necessarily need to copolymerize the monomer itself, but after reacting with a monomer that can be derived into the target copolymer (A), it is further reacted. It can also be guided to the target (A). For example, after ethylene and vinyl acetate are polymerized by the above-mentioned known method, this is hydrolyzed and further reacted with a branched aliphatic carboxylic acid having 5 to 24 carbon atoms, an acid halide or an acid anhydride thereof, and the desired ethylene. You may derive | lead to the copolymer which consists of a vinyl ester of C5-C24 branched aliphatic carboxylic acid. Further, after butadiene is copolymerized, it may be hydrogenated to form ethylene units, or after vinyl acetate is copolymerized, it may be derived into a branched aliphatic vinyl carboxylate unit by a transesterification reaction.

The oil-soluble nitrogen-containing compound (B) that is an essential component in the fluidity improver of the present invention is a compound other than (A), which is oil-soluble and has a nitrogen atom in the molecule. “Oil-soluble” in the present invention means that 1% by weight or more transparently dissolves in kerosene at 25 ° C.
The Mw of (B) is not particularly limited, and may be a single compound or a so-called polymer compound.
Preferred is MW = 200 to 200,000, more preferably 500 to 30,000.
Examples of (B) include amine compounds, amide compounds, amine salts, imide compounds, quaternary ammonium salt compounds, amino acids, urethane compounds, and urea compounds.
Of these, amine compounds, amide compounds and amine salts are preferred from the viewpoints that oil solubility is easily obtained and that the effect of improving fluidity is easily exhibited in combination with (A).

  Preferable (B) includes the following oil-soluble nitrogen-containing low molecular compound (B1) having an Mw of 1,000 or less and the following oil-soluble nitrogen-containing polymer compound (B2) having an Mw of 1,000 or more.

(B1) Oil-soluble nitrogen-containing low molecular weight compound (B11) amine compound;
Mono-, di- and trialkylamines having 1 to 36 carbon atoms, mono-, di- and trialkanolamines having 2 to 36 carbon atoms and the like.
(B12) an amide compound;
C6-C36 carboxylic acid amide, N-monoalkyl carboxylic acid amide, N, N-dialkyl carboxylic acid amide, etc.
(B13) Carboxylic acid salt Monoalkylamine, dialkylamine, or trialkylamine salt of a carboxylic acid having 6 to 36 carbon atoms in total.
In addition, carboxylic acid imides, quaternary ammonium carboxylates, amino acids, low molecular weight urethane compounds and the like can be mentioned.

(B2) oil-soluble nitrogen-containing polymer compound (B21) amino group-containing polymer compound;
A polymer having an amino group-containing vinyl monomer as an essential constituent monomer, and the amino group-containing vinyl monomer is exemplified by the amino group-containing vinyl monomers mentioned in the above (a3), and other monomers. And a copolymer thereof.
(B22) an amide group-containing polymer compound;
A polymer having a vinyl monomer having an amide group as an essential constituent monomer, and the vinyl monomer having an amide group includes N, N in addition to the amide group-containing vinyl monomer mentioned in the above (a3). -Dialkyl (meth) acrylamide and maleic acid di (N, N-dialkyl) amide are exemplified and may be a copolymer with another monomer.
Further, the amide group-containing polymer compound may be a polymer compound obtained by amidating a polymer having the carboxyl group-containing monomer mentioned in the above (a3) as an essential constituent monomer with an alkylamine. .
(B23) an amine base-containing polymer compound;
A polymer having a vinyl monomer having an amine base as an essential constituent monomer, and the vinyl monomer having an amine base is an amine salt (as an amine salt) of the carboxyl group-containing vinyl monomer mentioned in (a3) above. Is exemplified by mono, di or trialkylamine, and may be a copolymer with another monomer.
In addition, as the amine base-containing polymer compound, a polymer obtained by subjecting a polymer having the carboxyl group-containing monomer mentioned in the above (a3) as an essential constituent monomer to amine conversion with a mono-, di- or trialkylamine. It may be a compound.

  Of the above (B1) and (B2), the group represented by the general formula (1) or the pair represented by the general formula (2) is preferable from the viewpoint of the effect of improving fluidity when used in combination with (A). A compound having at least one of ions.

Here, R < ¹ > and R < ² > show a C8-24 saturated aliphatic hydrocarbon group.
However, R ¹ and R ² may be the same or different. When R ¹ and / or R ² has 8 or more carbon atoms, oil solubility is easily exhibited and sludge is hardly generated. Further, since R ¹ or R ² is not unsaturated but a saturated hydrocarbon group, the oxidation stability is good.
R ¹ and R ² are preferably straight-chain from the viewpoint of improving fluidity, and at least one of them preferably has 14 to 24 carbon atoms.

Examples of the compound having the group represented by the general formula (1) include di- and trialkylamines in the above (B11), dialkylaminoalkyl (meth) acrylate or dialkylaminoalkyl (meth) acrylamide in (B21). And a polymer compound having an N, N-dialkylcarboxylic acid amide in (B12) and a polymer compound having an N, N-dialkylamide group in (B22). It is done.
As a compound having a counter ion represented by the general formula (2), the dialkylamine salt of the above (B13) and the dialkylamine salt of the carboxyl group-containing vinyl monomer of (B23) are essential constituent monomers. And a polymer compound obtained by subjecting a polymer having a carboxyl group-containing monomer as an essential constituent monomer to amine conversion with a dialkylamine.

  In addition, examples of the compound having the group represented by the general formula (1) and the counter ion represented by the general formula (2) include a mixture of compounds having each group or counter ion, and each group and pair in one molecule. Examples thereof include a polymer compound having ions.

  Preferred dialkylamines used for introducing the group represented by the general formula (1) or the counter ion represented by the general formula (2) include, for example, dioctadecylamine, dipalmitylamine, dicoconut fatty amine, Examples include behenylamine and ditallow fatty amine.

Of these, (B) is preferably a polymer compound having an N, N-dialkylamide group, a high ion having a counter ion represented by the general formula (2), from the viewpoint of fluidity-improving effect in combination with (A). It is a molecular compound or a polymer compound having an N, N-dialkylamide group and a counter ion represented by the general formula (2) in one molecule.
Among these, a polymer compound obtained by reacting a copolymer having an unsaturated carboxylic acid as an essential constituent monomer with a dialkylamine having 8 to 24 carbon atoms in the alkyl group is particularly preferable.

  Preferable specific examples of (B) include amidated products of (meth) acrylic acid copolymers with dialkylamines, and amide / amine chlorides of maleic anhydride copolymers with dialkylamines.

  In the fluidity improver of the present invention, the weight percentage of (B) based on the weight of the copolymer (A) is preferably 1 to 30%, more preferably 1 to 20%. Dispersibility can be improved with a smaller addition amount by setting the ratio of (B) to 1% or more, and low-temperature fluidity can be improved with a smaller addition amount by setting the ratio of (B) to 30% or less. Is preferable.

The fluidity improver of the present invention may further contain an oil-soluble phenol resin (C) and / or a copolymer (D) having a hexane insoluble content at + 10 ° C. exceeding 50% by weight as necessary.
Examples of the oil-soluble phenol resin (C) include condensates of alkylphenols with aldehydes or alkylated products of condensates of phenol with aldehydes.
Examples of the aldehyde used here generally include aliphatic aldehydes having 1 to 4 carbon atoms such as formaldehyde, acetaldehyde and butyraldehyde, preferably formaldehyde.
Alkylphenols in the case of condensation of alkylphenols with aldehydes are, for example, n-, sec- and tert-butylphenol, n- and isopentylphenol, n- and isohexylphenol, n- and isooctylphenol, n- and isononylphenol, Examples include n- and isodecylphenol, and n- and isododecylphenol, preferably iso and n-nonylphenol.
In the case of condensation of alkylphenol with aldehyde, the molar amount of aldehyde charged per mol of alkylphenol is usually about 0.5 to 2 mol, preferably 0.7 to 1.3 mol, especially equimolar amount of aldehyde is used. Is preferred.
The number average molecular weight (Mn) of (C) is preferably 400 to 10,000, and more preferably 400 to 5,000.

The copolymer (D) having a hexane insoluble content at + 10 ° C. of more than 50% by weight has more hexane insoluble content at + 10 ° C. than the copolymer (A), and exceeds 50% by weight. By containing (D), the fluidity improving effect is more easily exhibited.
Examples of the monomer constituting (D) include the same monomers as those constituting (A), and Mw is in the same range as (A), but insoluble in hexane at + 10 ° C. In order to obtain a copolymer having a content exceeding 50% by weight, it is preferable to graft polymerize (A) with an unsaturated carboxylic acid alkyl ester or the like.

The weight percentage of (C) or (D) based on the sum of (A) and (B) is preferably 35% or less, more preferably 1 to 35%, and particularly preferably 1 to 20%. %. Dispersibility can be improved with a smaller addition amount by making the ratio of (C) or (D) 1% or more, and a smaller addition amount by making the ratio of (C) or (D) 35% or less. It is preferable in that the low temperature fluidity can be improved.
The fluidity improver of the present invention preferably contains both (C) and (D), and the weight ratio (C) / (D) is preferably 10/90 to 90/10. .

  Each content of (A), (B), (C) and (D) in the fluidity improver of the present invention is (A) preferably 58 to 99%, more preferably 70 to 97%. , (B) is preferably 0.5 to 23%, more preferably 0.7 to 17%, and (C) is preferably 0 to 20%, more preferably 0.8 to 13%. , (D) is preferably 0 to 20%, more preferably 0.8 to 13%.

The fluidity improver composition for fuel oil of the present invention contains the above fluidity improver and other additives and / or diluents (S).
Other additives include, for example, lubricity improvers (such as oleic acid, linoleic acid, linolenic acid, and glycerin esters thereof), rust inhibitors (aliphatic amines and salts thereof, organophosphates, organosulfonates, etc.) ), Antioxidants (hindered phenols, salicylidene derivatives, etc.), cetane number improvers (alkyl nitrate esters, amyl nitrate, isopropyl nitrate, etc.), detergent dispersants, combustibility improvers, conductivity enhancers, And other fluidity improvers [known ethylene / vinyl acetate copolymer, ethylene / vinyl acetate / α-olefin copolymer, ethylene / vinyl acetate / vinyl neodecanoate copolymer (provided that hexane insoluble matter is (A ) And (D) and the like, and fatty acid esters of polyols] and the like can also be included. The amount of other additives used is usually 0 to 10,000 ppm, preferably 0 to 5,000 ppm, based on the total weight of the fluidity improver composition.
The fluidity improver composition of the present invention can contain a diluent (S). By diluting with a diluent in advance, it is preferable in that it easily dissolves when added to fuel oil and the like, and low-temperature fluidity is easily developed. The fluidity improver composition containing the diluent (S) is obtained by polymerizing (A) or (B) in the presence of the diluent (S) and diluting with the diluent (S). Or may be diluted with a diluent (S) after polymerization. Moreover, you may add said other additive at any time. (S) is an aliphatic solvent [aliphatic hydrocarbon having 6 to 18 carbon atoms (hexane, heptane, cyclohexane, octane, decalin, kerosene, etc.)]; aromatic solvent {aromatic solvent having 7 to 15 carbon atoms [ Toluene, xylene, ethylbenzene, aromatic mixed solvent having 9 carbon atoms (a mixture of trimethylbenzene, ethyltoluene, etc.), aromatic mixed solvent having 10 to 11 carbon atoms, etc.]; Among these, preferred are aromatic solvents having 7 to 15 carbon atoms, and particularly preferred are aromatic mixed solvents having 9 carbon atoms and aromatic mixed solvents having 10 to 11 carbon atoms. The ratio of (S) in the fluidity improver composition is preferably 10 to 80% by weight, more preferably 10 to 45% by weight, and particularly preferably 20 to 35% by weight. A higher ratio of (S) is preferable in that it is easily dissolved in fuel oil or the like, but too much is not economical. The cloud point of the fluidity improver composition is preferably 80 ° C. or lower, more preferably −20 to 75 ° C., particularly preferably 0 to 70 ° C., and particularly preferably 10 to 65 ° C. By making a cloud point 80 degrees C or less, melt | dissolution in base oils, such as fuel oil, becomes easy. The cloud point of the fluidity improver composition is heated and uniformly dissolved, and then allowed to stand at room temperature and gradually cooled, and the temperature at which the solution starts to become cloudy is defined as the cloud point. Further, the kinematic viscosity at 100 ° C. of the fluidity improver composition is usually 200 mm ² / s or less, preferably 5 to 80 mm ² / s, and more preferably 10 to 60 mm ² / s. By making kinematic viscosity 200 mm < ² > / s or less, melt | dissolution in base oils, such as fuel oil, becomes easy. In addition, the fluidity improver composition of this invention can also be added to fuel oil separately in the component, and the order of addition in that case is not specifically limited.

The fuel oil composition of the present invention contains the above fluidity improver and fuel oil.
The method for producing the fuel oil composition of the present invention comprises mixing the above fluidity improver and fuel oil, mixing other additives as necessary, and the above fluidity improver composition and fuel oil. Any method such as a method of mixing and mixing other additives as necessary may be used.
As fuel oil, JIS No. 1 diesel oil, JIS No. 2 diesel oil, JIS No. 3 diesel oil and A heavy oil obtained by ordinary distillation of low-sulfur crude oil (for example, Minas crude oil, etc.) Desulfurized diesel oil and A heavy oil produced from crude oil through a hydrodesulfurization treatment process; JIS No. 1 diesel oil produced from a gas oil fraction obtained by blending the desulfurized diesel oil and straight run diesel oil (diesel before hydrodesulfurization process); Examples include JIS No. 2 diesel oil, JIS No. 3 diesel oil, JIS No. 3 diesel oil, and A heavy oil.
Among these, it is useful for JIS No. 1 diesel oil, JIS No. 2 diesel oil, JIS No. 3 diesel oil and JIS No. 3 diesel oil produced by blending 50% or more of the desulfurized diesel oil produced through the hydrodesulfurization process. In particular, the fluidity improver of the present invention is useful in JIS No. 2 diesel oil and JIS No. 3 diesel oil.
In the present invention, the cloud point of the fuel oil has a lower limit of usually −25 ° C., preferably −8 ° C., more preferably −6 ° C., and an upper limit of + 5 ° C., preferably + 2 ° C., more preferably 0 ° C. When a fuel oil having a cloud point in the above range is used, the fuel oil composition of the present invention is particularly excellent in terms of both low-temperature fluidity and wax dispersibility.

The sulfur content of the fuel oil used in the fuel oil composition in the present invention is not particularly limited, but the effect of the fluidity improver of the present invention is sufficient even if the sulfur content of the fuel oil is 0.05% or less. The fuel oil composition of the present invention may be a fuel oil composition using a fuel oil having a sulfur content of 0.05% or less.
Further, the sulfur content of the fuel oil may be 0.01% or less, particularly 0.005% or less. Since the fuel oil having a lower sulfur content has a larger (αa) described later, that is, the wax precipitation temperature tends to be sharper, the fuel oil composition of the present invention can be preferably exhibited in terms of both low-temperature fluidity and oil permeability. .

When the absolute value αa of α in the following relational expression (1) is 0.1 to 2, the fuel oil composition of the present invention has both excellent low-temperature fluidity and excellent oil permeability. It is preferable from the viewpoint that it can be achieved.
αa is preferably 0.2 to 1.5, more preferably 0.23 to 0.9, and particularly preferably 0.27 to 0.75.
y = αx + β (1)
In the formula, x is the average carbon number of n-paraffins having 20 or more carbon atoms in the fuel oil, y is the content (% by weight) of n-paraffins having 20 or more carbon atoms in the fuel oil, and β is 20 carbon atoms. The content (% by weight) of n-paraffin.

y can be determined by the following gas chromatography method.
A capillary gas chromatograph apparatus (for example, GC-14B, FID detector manufactured by Shimadzu Corporation) with a capillary column (for example, DB-1HT manufactured by J & W Scientific, length 30 m, aperture 0.25 mm, film thickness 0.1 μm) was used. Helium is used as a carrier gas, the column temperature is raised from 140 to 355 ° C. at 5 ° C. at an injection temperature of 360 ° C. and a detector temperature of 360 ° C., and a sample volume of 0.5 μl is injected at a split ratio of 1/60. taking measurement. As the measurement result, the area% of each peak is obtained using a data processing device (for example, Chromatopack CR-7A manufactured by Shimadzu Corporation).
In addition, the branched paraffin and naphthene components in the fuel oil have many isomers, and the peak is often not sufficiently divided, and the peak may partially overlap with the peak of n-paraffin, but the peak is divided vertically. Thus, the area% can be obtained. In addition, the identification of n-paraffin can be determined from a comparison of retention times using a standard.
The area% of each n-paraffin peak determined by the above measurement relative to the total peak of the entire sample is defined as the content (y) (% by weight) of each n-paraffin.
For each n-paraffin having 20 or more carbon atoms determined above, the carbon number (x) is plotted on the x axis and the content (y) (% by weight) is plotted on the y axis. First-order approximation is performed by the least square method to obtain the above relational expression (1), and the absolute value (αa) of the slope (α) is obtained.
Depending on the type of fuel oil, the content distribution of n-paraffin may deviate from the linear approximation, and the correlation coefficient (r ² ) may be less than 0.94. In that case, the calculation is performed by omitting from the least square method in order from the one having the smallest carbon content and the largest one so that the correlation coefficient becomes 0.94 or more.

  The content of the fluidity improver of the present invention in the fuel oil composition of the present invention is preferably 10 to 2,000 ppm based on the weight of the fuel oil.

[Example]
The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. All parts represent parts by weight.

[Copolymer (A)]
Production Example 1 (A-1)
In a glass flask equipped with a thermometer and a stirrer, ethylene / vinyl acetate / vinyl neodecanoate copolymer (83/16/1 mol%, branching degree 2.9, Mn 4,000, Mw 7,300) 200 parts, 800 parts of hexane was added and dissolved by stirring at 60 ° C. Next, this was allowed to stand at −20 ° C. for 4 hours and then centrifuged at −20 ° C. (10,000 rpm × 30 minutes) to isolate insoluble matter. The obtained insoluble matter was dried under reduced pressure at 150 ° C. to obtain 124 parts of copolymer (A-1). The analytical value of the copolymer (A-1) is shown in Table 1.

Production Example 2 (A-2)
A pressure-resistant tubular reactor was supplied with a mixture of ethylene 533 parts, vinyl acetate 360 parts, vinyl neodecanoate 107 parts, propionaldehyde 40 parts and diisopropyl percarbonate 0.5 parts, and conditions of 120 ° C., 110 MPa, residence time 3 minutes Polymerized below. After completion of the polymerization, unreacted monomers were removed by drying under reduced pressure to obtain a copolymer (A-2). The analytical value of the copolymer (A-2) is shown in Table 1.

Production Example 3 (A-3)
Polymerization was carried out in the same manner as in Production Example 2 except that the raw material monomer ratio was changed to 506 parts of ethylene, 312 parts of vinyl acetate, and 182 parts of vinyl neodecanoate to obtain a copolymer (A-3). The analytical value of the copolymer (A-3) is shown in Table 1.

[Oil-soluble nitrogen-containing compound (B)]
The following compounds were used as (B).
(B-1); a terpolymer composed of an α-olefin having 14/16 carbon atoms, maleic anhydride and methoxypolyethylene glycol allyl ether (molar ratio 48/50/2) and 2 moles per mole of maleic anhydride Reaction product with ditallowamine (Mn = about 10,000, Mw = about 15,000).
(B-2): Amide amine salt produced from 1 mol of phthalic anhydride and 2 mol of a mixture of an equal weight ratio of ditallow aliphatic amine and dicoconut aliphatic amine.

[Oil-soluble phenolic resin (C)]
The following compounds were used as (C).
(C-1); Nonylphenol-formaldehyde resin (Mn = 3,400, Mw = 5,200)

[Copolymer (D) in which hexane insoluble content at + 10 ° C. exceeds 50% by weight]
The following compounds were used as (D).
Production Example 4 (D-1)
An ethylene / vinyl acetate copolymer (96.5 / 3.5 mol%, degree of branching 3.4, Mn2,600, Mw6) was added to a glass reactor equipped with a stirrer, a heating device, a thermometer, and a nitrogen blowing tube. , 600) and 500 parts of di-2-ethylhexyl fumarate were added, and the temperature was raised to 155 ° C. under a nitrogen atmosphere. Thereto was added dropwise 20 parts of jetty butyl peroxide and 1.7 parts of lauryl mercaptan at 155 ° C. over 2 hours. After completion of the dropwise addition, the mixture was further reacted at 155 ° C. for 2 hours to obtain a copolymer (D-1). Copolymer (D-1) was a copolymer obtained by grafting di-2-ethylhexyl fumarate to the above ethylene / vinyl acetate copolymer. The analytical value of the copolymer (D-1) is shown in Table 1.

Production Example 5 (D-2)
A commercially available ethylene / vinyl neodecanoate copolymer [93/7 mol%, branching degree 3.5, Mn7,600, Mw15,000, hexane-insoluble content 55% by weight at + 10 ° C] is copolymerized (D-2 ). The analytical value of the copolymer (D-2) is shown in Table 1.

Comparative Production Example The following (X-1) was used as a comparative copolymer of the copolymer (A).
Comparative production example 1
Commercially available ethylene / vinyl acetate copolymer [85/15 mol%, degree of branching 3.2, Mn3,300, Mw8,300, hexane insoluble content at + 10 ° C 18% by weight, hexane insoluble content at -20 ° C 52% by weight ] Is a copolymer (X-1). The analytical value of the copolymer (X-1) is shown in Table 1.

[Preparation of fluidity improver composition]
Examples 1 to 4 and Comparative Example 1
A glass container equipped with a stirrer, a heating device and a thermometer is charged with the components shown in Table 2 in the number of parts shown in Table 2, and further, a petroleum aromatic mixed solvent having 10 to 11 carbon atoms as a diluent (primary distillation) Points 182 ° C. to end point 204 ° C.) were added in the number of parts shown in Table 2 and uniformly dissolved at 100 ° C. to obtain fluidity improver compositions of Examples and Comparative Examples.

[Preparation of Fuel Oil Composition-1]
Examples 5 to 13 and Comparative Examples 2 to 4
The flow improver composition shown in Table 4 was added to any fuel oil (light oil) of fuel oil 1 to fuel oil 3 having the properties shown in Table 3 and mixed uniformly with CFPP. Low temperature fluidity was evaluated by measuring [Clogging point of low temperature filter (° C.): method described in JIS K2288].
Regarding the wax dispersibility, the fuel oil mixed uniformly with the addition amount shown in Table 4 is put into a 100 ml graduated cylinder and kept at a temperature 10 ° C. higher than the cloud point of each fuel for 1 hour in an air bath. After cooling to the temperature shown in Table 3 at a rate of 1 ° C./hour and holding for 1 hour, the wax dispersion phase was visually determined as a proportion of the whole. The results are shown in Table 4. As is clear from this, the fluidity improver composition of the present invention provides very low temperature fluidity and wax dispersibility for any diesel oil.

[Preparation of fuel oil composition-2]
Examples 14 to 21, Comparative Examples 5 and 6
The flowability improver composition shown in Table 5 was added to the fuel oil (A heavy oil) of the fuel oils 4 and 5 having the properties shown in Table 3 and added uniformly, and CFPP [ Cryogenic filter clogging point (° C): Method described in JIS K2288] Correction method CFPP [Cryogenic filter clogging point correction method No. 4 (° C): Japan Oil Society Fuel Oil Subcommittee, Fluidity Technical Committee, 1993 The method described in the activity report] was measured. The results are shown in Table 5. As is apparent from the above, the fluidity improver composition of the present invention gives very low temperature fluidity to any A heavy oil.

  The fluidity improver for fuel oils of the present invention can improve the dispersibility of wax crystals at low temperatures of fuel oils, particularly low sulfur content fuel oils, and improve low temperature fluidity. It is useful as a fluidity improver for fuel oil.

Claims (12)

   Containing a copolymer (A) having ethylene (a1) and a vinyl ester (a2) of an aliphatic saturated carboxylic acid having 2 to 24 carbon atoms as an essential constituent monomer, and an oil-soluble nitrogen-containing compound (B); A fluidity improver for fuel oil, wherein the hexane insoluble content at + 10 ° C of (A) is 30 wt% or less, and the hexane insoluble content at -20 ° C is 60 wt% or more.   The fluidity according to claim 1, wherein the copolymer (A) is a copolymer comprising ethylene (a1), vinyl acetate and a vinyl ester of an aliphatic saturated carboxylic acid having 3 to 22 carbon atoms as essential constituent monomers. Improver. The fluidity improver according to claim 1 or 2, wherein (A) is a copolymer having a degree of branching measured by ¹ H-NMR of 0.3 to 2.2%. The fluid according to any one of claims 1 to 3, wherein the oil-soluble nitrogen-containing compound (B) is a compound having at least one of a group represented by the general formula (1) or a counter ion represented by the general formula (2). Improver.
(In the formula, R ¹ and R ² represent a saturated aliphatic hydrocarbon group having 8 to 24 carbon atoms.)   The oil-soluble nitrogen-containing compound (B) is a polymer compound having an N, N-dialkylamide group, a polymer compound having a counter ion represented by the general formula (2), or an N, N-dialkylamide group and a general formula 5. The fluidity improver according to claim 4, which is a polymer compound having the counter ion represented by (2) in one molecule.   6. The fluidity improvement according to claim 5, wherein the polymer compound is a polymer compound obtained by reacting a copolymer having an unsaturated carboxylic acid as an essential constituent monomer with a dialkylamine having 8 to 24 carbon atoms in the alkyl group. Agent.   The fluidity improver according to any one of claims 1 to 6, wherein the oil-soluble nitrogen-containing compound (B) based on the weight of the copolymer (A) is 1 to 30% by weight.   The fluidity improver according to any one of claims 1 to 7, further comprising an oil-soluble phenol resin (C) and / or a copolymer (D) having a hexane insoluble content at + 10 ° C exceeding 50% by weight.   A fluidity improver composition for fuel oil containing the fluidity improver according to any one of claims 1 to 8, and another additive and / or diluent (S).   A fuel oil composition comprising the fluidity improver according to claim 1 and a fuel oil. The fuel oil composition according to claim 10, wherein the fuel oil is a fuel oil satisfying the following relational expression (1).
y = αx + β (1)
[Wherein x is the average carbon number of n-paraffins having 20 or more carbon atoms in the fuel oil, y is the content (% by weight) of n-paraffins having 20 or more carbon atoms in the fuel oil, and β is 20 carbon atoms. The n-paraffin content (% by weight) and α is a number with an absolute value of 0.1-2. ]   The fuel oil composition according to claim 10 or 11, wherein the fuel oil is a fuel oil having a sulfur content of 0.05% by weight or less.