JP4520160B2 - Fluidity improver for fuel oil - Google Patents

Description

The present invention relates to a technique for improving the fluidity of fuel oil such as light oil and heavy fuel oil A under cold conditions.

As is well known, fractions having a boiling point in the range of 150 to 450 ° C. among fractions obtained by distilling crude oil are used in large quantities as various fuel oil sources such as kerosene, light oil, and heavy oil A. Among these fuel oil sources, light oil and heavy oil A may cause a serious problem because the wax contained in the oil is precipitated as crystals and the fluidity is significantly deteriorated at low temperatures. For example, under cold conditions, wax in light oil may precipitate, and the light oil itself becomes a semi-solid or gel, which may clog the oil supply pipe or make it impossible to supply fuel to the internal combustion engine. A heavy oil is used for driving a fishing boat engine, a warming machine for house warming cultivation, and building heating, and this may cause combustion failure due to wax crystals deposited under cold.

As one method for improving the low temperature fluidity of fuel oil, a method of adding a fluidity improver is known. The action of the fluidity improver is to change the size, shape and surface of the wax crystal when it precipitates from the fuel oil, thereby preventing the wax crystal from growing enormously.

As a method for evaluating the low temperature fluidity of a fuel oil to which a fluidity improver is added, generally CFPP (clogging point, JIS K-2288), PP (pour point, JIS K-2269), CP (cloudy). And JIS K-2269) are widely used. Recently, modified CFPP having a high correlation with actual use conditions has been used particularly with respect to A heavy oil (see Non-Patent Document 1).

Conventional fluidity improvers include ethylene-vinyl acetate copolymer, polyalkyl acrylate, polyalkyl methacrylate, polydialkyl fumarate, styrene-acrylic ester copolymer, alkenyl succinic acid amide, olefin copolymer, halogenated Various chemically synthesized products such as polyalkylene, polyhydric alcohol-saturated fatty acid ester and various block copolymers have been proposed.

However, even if the fuel oil to which these fluidity improvers are added is left for a relatively long time at a low temperature, fine wax crystals modified by the action of the fluidity improver precipitate and separate. The phenomenon of agglomeration may occur gradually. When such a phenomenon occurs, the precipitated and separated wax crystals cause clogging of strainers and filters. Furthermore, it becomes difficult to start the engine or, in some cases, troubles such as engine stop occur, and the effect of adding the fluidity improver is halved.

Therefore, in recent years, in order to improve such problems, fluidity improvers with improved wax crystal dispersion performance have been developed. Typical examples include esters of alkylene oxide adducts such as alcohols with saturated fatty acids, esters of α-olefin-maleic anhydride copolymers with alcohols, and the like (see Patent Documents 1 to 6).

Although these fluidity improvers have improved wax crystal dispersion performance, they are difficult to dissolve in fuel oil or are not effective unless added in a relatively large amount. The oil permeability of the fuel oil added with may deteriorate. In addition, depending on the properties of the fuel oil, there are some cases where the effect decreases as the amount added increases, which is not satisfactory.
JP-A-53-124515 Japanese Patent Publication No. 60-33154 Japanese Patent Laid-Open No. 4-57888 Japanese Examined Patent Publication No. 4-59356 Japanese Patent Laid-Open No. 9-235574 Japanese Patent Laid-Open No. 10-245574 Japan Petroleum Institute Fuel Oil Subcommittee, 1994 Petroleum Product Discussion Meeting

As described above, the present situation is that a fluidity improver that exhibits the effect of addition at a low addition amount and has excellent wax crystal dispersion performance has not yet been developed. The problem to be solved by the present invention is to develop a fluidity improver for fuel oil having wax crystal dispersion performance, which keeps the modified fine wax crystals in a dispersed state for a relatively long time.

The inventors of the present invention have reached the present invention as a result of studies to solve such problems. That is, the present invention relates to the structural unit (A) derived from the esterification reaction product of acrylic acid and / or methacrylic acid and an alcohol having 1 to 16 carbon atoms, and mono- or monohydric acid having 8 to 28 carbon atoms and maleic anhydride. And / or the structural unit (B) derived from the amide reaction product with dialkylamine so that the molar ratio of each structural unit is in the range of (A) :( B) = 1: 9 to 9: 1. And a copolymer having a number average molecular weight in the range of 1,000 to 100,000, or a mixture of this copolymer and at least one of the following (a) to (d): A fuel oil fluidity improver and a fuel oil containing 0.005 to 0.1% by mass of the fuel oil fluidity improver.
(A) An ethylene-vinyl acetate copolymer containing a structural unit derived from vinyl acetate in the range of 10 to 40% by mass and having a number average molecular weight in the range of 1,500 to 10,000.
(B) Branched polyethylene having a number average molecular weight in the range of 500 to 10,000.
(C) Chlorinated polyethylene having 5 to 25% by mass of chlorine among all the constituent elements and having a number average molecular weight in the range of 1,000 to 50,000.
(D) A molar ratio of an aliphatic hydrocarbon having a melting point of 38 to 71 ° C. chlorinated so that chlorine is in a range of 10 to 20% by mass and aromatic hydrocarbon among all constituent elements is 2 : Friedel-Crafts reaction product obtained by reacting in the range of 1 to 5: 1.

  The fuel oil containing the fluidity improver for fuel oil of the present invention has excellent low temperature fluidity and wax crystal dispersibility. Although the mechanism of the effect is unknown, there are many unknown parts, but it seems to act to keep the wax crystals in which the constituent parts derived from the amide reaction of the acid anhydride and amine in the copolymer are precipitated in a dispersed state. It is done.

Hereinafter, the present invention will be described in detail.
The raw material of the structural unit (A) of the copolymer used in the present invention is acrylic acid or / and methacrylic acid and an alcohol having 1 to 16 carbon atoms, preferably 8 to 14 carbon atoms. Even a mixture of different carbon numbers may be used.

The raw materials for the structural unit (B) are maleic anhydride and mono- and / or dialkylamine. The one or two alkyl groups bonded to the nitrogen atom have a carbon number of 8 to 28, preferably 8 to 20, more preferably 12 to 20. The dialkylamine may be one having the same alkyl group or one having different alkyl groups, and various dialkylamines can be used. The difference in carbon number between the two alkyl groups is preferably less than 8.

The molar ratio of the structural units (A) and (B) in the copolymer according to the present invention is in the range of (A) :( B) = 1: 9 to 9: 1, preferably (A) :( B) = 3: 7 to 7: 3. Further, other monomers can be copolymerized within a range that does not impair the effects obtained by the present invention. In that case, the sum of (A) and (B) in the copolymer is preferably 80 mol% or more, more preferably 90 mol% or more, and particularly preferably 95 mol% or more. The mode of the copolymer of the present invention may be either a random copolymer or a block copolymer.

The copolymer of the present invention has a number average molecular weight in the range of 1,000 to 100,000, preferably 1,000 to 50,000, more preferably 1,000 to 10,000. It is. The number average molecular weight can be measured by gel permeation chromatography based on polystyrene.

There is no restriction | limiting in particular in the method of obtaining this invention product, It can obtain by a well-known method. For example, an esterification reaction product of acrylic acid or / and methacrylic acid of the structural unit (A) and an alcohol having 1 to 16 carbon atoms and maleic anhydride as a raw material of the structural unit (B) are converted into a peroxide. The polymerization is carried out under known conditions using a commonly used radical polymerization initiator such as azo compound and azo compound, and 0.9 to 1 with respect to 1 mol of the resulting copolymer and maleic anhydride-derived structural unit. There is a method of obtaining the product of the present invention by heating 2 mol of mono- and / or dialkylamine to 60 to 90 ° C., preferably 70 to 80 ° C. for amide reaction.

At this time, a reaction solvent may not be used, but a solvent such as benzene, toluene, xylene, or chlorobenzene can be used. In that case, the amount of the solvent is suitably in the range of 20 to 80% by mass with respect to the total of the copolymer of methacrylic acid involved in the reaction and the alcohol having 1 to 16 carbon atoms and maleic anhydride. Use of the reaction solvent facilitates handling and improves the solubility in fuel oil.

The copolymer obtained in this way is also used as a mixture with at least one of (a) to (d), and the blending amount is preferably such that the copolymer of the present invention is 70% by mass or more. More preferably, it is 80% by mass or more, and particularly preferably 90% by mass or more. Also. In addition to (a) to (d), it may be mixed with a rust inhibitor, a dye, a cleaning dispersant, an antioxidant, an antistatic agent and the like which can be usually added to the fuel oil.

The present invention will be specifically described below with reference to specific synthesis examples and examples, but the present invention is not limited to these synthesis examples and examples. In this example, the number average molecular weight (Mn) is a gel permeation chromatography (GPC) HLC-8120GPC manufactured by Tosoh Corporation, and the columns are the same as those of TSK GEL Super HH MIX, H-H3000, and H-H2000. The H-H2000 was calculated from a calibration curve using a polystyrene standard sample using THF as an eluent and a differential refractometer as a detector.

(Production Example 1) In a 300 mL flask equipped with a stirrer, a thermometer, a nitrogen blowing tube, and a condenser, 62 g of alkyl methacrylate having an average alkyl group of 14 alkyl groups corresponding to the side chain and 18 g of maleic anhydride (molar ratio is 5.5: 4.5), 149 g (65 mass %) of the solvent was charged, and polymerization was carried out by reacting at 6O <0> C for 6 hours using ditertiary butyl peroxide as a polymerization initiator. Subsequently, 139 g of the copolymer obtained in the same reactor and 64 g of dialkylamine having about 18 carbon atoms of two alkyl groups bonded to the nitrogen atom (molar ratio of structural unit derived from maleic anhydride and dialkylamine) 1: 1), and amide reaction at 80 ° C. for 3 hours, and 23 g (10% by mass ) of branched polyethylene having a number average molecular weight of 1,000 is mixed to thereby improve the fluidity improver for fuel oil of the present invention. It was. The number average molecular weight of the reaction product of the obtained copolymer and dialkylamine was 5,800.

(Production Example 2) In a 300 mL flask equipped with a stirrer, a thermometer, a nitrogen blowing tube and a condenser, 98 g of alkyl methacrylate having an average alkyl group of 12 alkyl groups corresponding to the side chain and 11.3 g (mole) of maleic anhydride The ratio was 7.7: 2.3), 93 g (46% by mass ) of the solvent was charged, and polymerization was carried out at 120 ° C. for 6 hours using ditertiary butyl peroxide as a polymerization initiator. Subsequently, 169 g of the copolymer obtained in the same reactor, and 31 g of dialkylamine having about 12 carbon atoms of two alkyl groups bonded to the nitrogen atom (molar ratio of maleic anhydride-derived structural unit to dialkylamine) 1: 1), and amide reaction at 80 ° C. for 3 hours, and 22 g (10% by mass ) of branched polyethylene having a number average molecular weight of 1,000 is mixed to thereby improve the fluidity improver for fuel oil of the present invention. It was. The number average molecular weight of the reaction product of the obtained copolymer and dialkylamine was 12,100.

(Production Example 3) In a 300 mL flask equipped with a stirrer, a thermometer, a nitrogen blowing tube and a condenser, 62 g of alkyl methacrylate having an average alkyl group of 14 alkyl groups corresponding to the side chain, and 18 g of maleic anhydride (molar ratio) 5.5: 4.5), 149 g (65 mass %) of the solvent was charged, and polymerization was carried out by reacting at 6O <0> C for 6 hours using ditertiary butyl peroxide as a polymerization initiator. Subsequently, 162 g of the copolymer obtained in the same reactor and 37 g of a monoalkylamine having about 18 carbon atoms in one alkyl group bonded to a nitrogen atom (a maleic anhydride-derived structural unit and a monoalkylamine The molar ratio was 1: 1), and the amide reaction was carried out at 80 ° C. for 3 hours to obtain 22 g (10% by mass ) of ethylene-vinyl acetate copolymer containing 15% by mass vinyl acetate and having a number average molecular weight of 6,000. By adding, it was set as the fluidity improver for fuel oils of this invention. The number average molecular weight of the reaction product of the obtained copolymer and monoalkylamine was 4,700.

(Comparative example) The chemically synthesized product shown in Table 1 was used as a comparative example of the fluidity improver for fuel oil in the present invention.

The fluidity improvers for fuel oils of Production Examples 1 to 3 and Comparative Examples 1 to 4 were added to the fuel oils shown in Table 2, respectively, and stirred at 60 ° C. for 15 minutes to confirm that they were completely dissolved. .

CFPP and PP of fuel oil added with 0.01% by mass of a fluidity improver for fuel oil and fuel oil added with 0.03% by mass were measured (JIS K-2288, JIS K-2269) and the effect of addition was confirmed. did. The results of CFPP are shown in Table 3, and the results of PP are shown in Table 4.

Further, 100 ml of fuel oil added with 0.03% by mass of a fluidity improver for fuel oil was placed in a 100 ml graduated cylinder, and allowed to stand for 24 hours in CFPP without adding the fluidity improver for fuel oil of each fuel oil. The volume ratio (%) of the wax crystal dispersion layer to the entire fuel oil was defined as the wax crystal dispersion performance. The results of the wax dispersion performance are shown in Table 5.

From Tables 3 to 5, the fuel oil containing the fuel oil fluidity improver in the present invention is superior in low temperature fluidity and wax crystal dispersibility to the fuel oil containing the fuel oil fluidity improver of the comparative example. It is clear to have. This is the effect of the fluidity improver for fuel oil in the present invention.

Claims (3)

A structural unit (A) derived from an esterification reaction product of acrylic acid or / and methacrylic acid and an alcohol having 1 to 16 carbon atoms, and maleic anhydride and a mono- and / or dialkylamine having 8 to 28 carbon atoms The structural unit (B) derived from the amide reaction product is included so that the molar ratio of each structural unit is in the range of (A) :( B) = 1: 9 to 9: 1, and the number average molecular weight A fluidity improver for fuel oil, characterized by comprising a copolymer having a molecular weight of 1,000 to 100,000. A fluidity improver for fuel oil, comprising a mixture of at least one of the following (a) to (d) and the copolymer according to claim 1.
(A) An ethylene-vinyl acetate copolymer containing 10 to 40% by mass of a structural unit derived from vinyl acetate and having a number average molecular weight of 1,500 to 10,000.
(B) Branched polyethylene having a number average molecular weight in the range of 500 to 10,000.
(C) Chlorinated polyethylene having a chlorine content of 5 to 25% by mass and a number average molecular weight of 1,000 to 50,000 among all the constituent elements.
(D) A molar ratio of aliphatic hydrocarbons having a melting point of 38 to 71 ° C. and chlorinated aliphatic hydrocarbons in a range of 10 to 20% by mass among all the constituent elements is 2 : Friedel-Crafts reaction product obtained by reacting in the range of 1 to 5: 1. A fuel oil comprising 0.005 to 0.1% by mass of the fluidity improver for fuel oil according to any one of claims 1 and 2.