JP6385199B2 - Light oil additive - Google Patents

Description

  The present invention relates to a light oil additive and a light oil composition containing the same.

  From the viewpoint of air pollution, low-sulfur diesel diesel oil is widely used. However, a reduction in the sulfur content in light oil leads to an increase in the coefficient of friction, which causes troubles such as wear of the fuel pump due to a decrease in engine lubricity.

  Therefore, an oily agent is added in order to improve the lubricity in the low sulfur diesel light oil. Examples of the oily agent include a diesel engine fuel additive (Patent Document 1) containing an ester of a carboxylic acid having 2 to 50 carbon atoms and an alcohol having one or more carbon atoms, monoglyceride which is a reaction product of fatty acid and glycerin. Or the light oil additive containing a diglyceride (patent document 2) etc. are known.

Japanese National Patent Publication No. 8-505893 JP-A-9-13052 Japanese Patent Laid-Open No. 9-87641 JP 2008-143939 A International Publication No. 2010/010952

Among the oil-based agents added to low-sulfur diesel light oil, monoglyceride and diglyceride having a predetermined fatty acid shown in Patent Document 2 as a constituent fatty acid exhibit excellent lubricity. However, light oil additives are required not only for lubricity but also for low temperature resistance in practice. For example, when turbidity occurs at low temperatures or fluidity decreases, not only the workability when blended with light oil is remarkably deteriorated, but the composition distribution of the light oil additive results in the lubricity of light oil, etc. There is a concern that performance cannot be kept stable. Therefore, the light oil additive is required to have resistance even under conditions that consider transportation, storage and use in cold regions.
As a technology that considers the use of fuel oil at low temperatures, a low temperature fluidity improvement method for fuel oil that uses a nonionic surfactant in combination with a low temperature fluidity improver such as ethylene-vinyl acetate copolymer (patented) Literature 3), fatty acid alkyl ester composition containing polyhydric alcohol fatty acid ester with HLB of 1 to 9 (Hex. Patent Literature 4), which improves the low temperature fluidity of fatty acid alkyl ester which is a light oil alternative fuel, has a hydroxyl value of A polyglycerin fatty acid ester which is an esterified product of a polyglycerin having a primary hydroxyl group content of 50% or more of all the hydroxyl groups of polyglycerol and a fatty acid, and having a hydroxyl value of 850 mgKOH / g or less Cloud point depressant for fatty acid alkyl ester containing polyglycerin fatty acid ester of 100 mgKOH / g or less (special Document 5) have been reported, it does not improve the low temperature resistance of the oily agent that imparts lubricity to the low sulfur diesel fuel oil.

  Therefore, the present invention relates to providing a light oil additive having excellent lubricity, low cloud point and pour point, and excellent low temperature resistance.

  The present inventors have excellent lubricity when a predetermined amount of a predetermined polyglycerol fatty acid monoester having a degree of polymerization of glycerol of 2 or more and 9 or less is contained in a light oil additive containing a predetermined glycerol fatty acid ester. However, it has been found that the cloud point and the pour point are greatly lowered and the low temperature resistance is excellent.

That is, the present invention includes the following components (A) and (B):
(A) Compound represented by the following general formula (1)

(In the formula, X ¹ , X ² and X ³ are one or more selected from a hydrogen atom and a group —COR ¹ , and at least one of X ¹ , X ² and X ³ is a hydrogen atom, X ¹ , At least one of X ² and X ³ is a group —COR ¹ and the group —COR ¹ represents a fatty acid residue having 10 to 22 carbon atoms.
(B) A component containing 100 parts by mass of component (A) containing a polyglycerol fatty acid monoester which is a monoester of a polyglycerol having a degree of polymerization of 2 to 9 and a fatty acid having 10 to 22 carbon atoms. A gas oil additive having a content of (B) of 0.05 parts by mass or more and 9 parts by mass or less is provided.
The present invention also provides a light oil composition containing the light oil additive described above.

  ADVANTAGE OF THE INVENTION According to this invention, the light oil additive which has a low cloud point and a pour point and was excellent in low temperature tolerance can be provided. The light oil additive of the present invention is excellent in lubricity, that is, the effect of reducing the friction coefficient, and is suitably used for low sulfur diesel light oil.

[Ingredient (A)]
The component (A) used in the present invention is a compound represented by the following general formula (1) (hereinafter also referred to as “compound (1)”).

(In the formula, X ¹ , X ² and X ³ are one or more selected from a hydrogen atom and a group —COR ¹ , and at least one of X ¹ , X ² and X ³ is a hydrogen atom, X ¹ , At least one of X ² and X ³ is a group —COR ¹ and the group —COR ¹ represents a fatty acid residue having 10 to 22 carbon atoms.
In the present invention, two or more compounds (1) may be used in combination.

In the general formula (1), the group —COR ¹ is a fatty acid-derived residue represented by R ¹ COOH. Carbon number of group -COR ¹ and fatty acid (R ¹ COOH) is 10 or more from the viewpoint of lubricity, preferably 14 or more, more preferably 16 or more, and 22 or less from the viewpoint of compatibility with light oil. Yes, preferably 20 or less.

That, ^{R 1} in the groups -COR ¹ represents an aliphatic hydrocarbon group having 9 to 21 carbon atoms, the carbon number of ^{R 1} is 9 or higher from the viewpoint of lubricity, preferably 13 or more, more preferably Is 15 or more, and is 21 or less, preferably 19 or less, from the viewpoint of compatibility with light oil.
Examples of the aliphatic hydrocarbon group represented by R ¹ include a straight chain hydrocarbon group, a branched chain hydrocarbon group, and an alicyclic hydrocarbon group. From the viewpoint of lubricity, a straight chain or branched chain hydrocarbon group is exemplified. Are preferred, and straight chain hydrocarbon groups are more preferred.
Examples of the linear hydrocarbon group include an undecyl group, a tridecyl group, a pentadecyl group, a heptadecyl group, a nonadecyl group, a heneicosyl group and the like; an alkenyl group such as an 8-heptadecenyl group; an 8,11-heptadecenyl group and the like Alkadienyl groups; alkatrienyl groups such as 4,8,11-heptadecatrienyl group, 5,8,11-heptadecatrienyl group, 8,11,14-heptadecatrienyl group and the like. Among these, from the viewpoint of lubricity and compatibility with light oil, an 8-heptadecenyl group and an 8,11-heptadecenyl group are preferable.

In the compound (1), the group —COR ¹ includes a saturated fatty acid residue such as lauroyl group, myristoyl group, palmitoyl group, stearoyl group, icosanoyl group, and behenoyl group; monounsaturated fatty acid residue such as oleoyl group Divalent or higher polyunsaturated fatty acid residues such as linoleyl group, α-linolenoyl group, γ-linolenoyl group, 5,9,12-octadecatrienoyl group; residue of tall fatty acid, residue of soybean fatty acid; , Residues of fatty acids derived from natural fats and oils such as residues of palm fatty acids and residues of rapeseed fatty acids. The number of carbon atoms of the monounsaturated fatty acid residue and the divalent or higher polyunsaturated fatty acid residue is preferably 18 or more from the viewpoint of lubricity and ease of production of the compound (1), and from the same viewpoint. , 22 or less, preferably 20 or less, and more preferably 18.
The group —COR ¹ is preferably a residue of tall fatty acid, an oleoyl group and a linoleyl group from the viewpoint of lubricity and compatibility with light oil.

Examples of fatty acids from which the group —COR ¹ is derived include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, icosanoic acid, and behenic acid; monounsaturated fatty acids such as oleic acid; linoleic acid, α- Bisaturated or higher polyunsaturated fatty acids such as linolenic acid, γ-linolenic acid, 5,9,12-octadecatrienoic acid; and fatty acids derived from natural fats and oils such as tall fatty acid, soybean fatty acid, palm fatty acid and rapeseed fatty acid It is done. The number of carbon atoms of the monounsaturated fatty acid and the divalent or higher polyunsaturated fatty acid is preferably 18 or more from the viewpoint of lubricity and ease of production of the compound (1), and from the same viewpoint, it is 22 or less. Yes, preferably 20 or less, more preferably 18.
The fatty acid is preferably oleic acid, linoleic acid and tall fatty acid from the viewpoint of lubricity and compatibility with light oil.

Of the total fatty acid residues in compound (1), the amount of monounsaturated fatty acid residues is preferably 10% by mass or more, more preferably 20% by mass or more, and still more preferably 25% by mass from the viewpoint of excellent lubricity. From the viewpoint of compatibility with light oil and suppression of precipitation at low temperature, it is preferably 50% by mass or less, more preferably 40% by mass or less.
Of the total fatty acid residues in compound (1), the amount of divalent or higher polyunsaturated fatty acid residues is preferably 30% by mass or more, more preferably 40% by mass or more, from the viewpoint of excellent lubricity. From the viewpoint of compatibility with light oil and suppression of precipitation at low temperature, it is preferably 80% by mass or less, more preferably 70% by mass or less.
Of the total fatty acid residues in compound (1), the amount of saturated fatty acid residues is preferably 20% by mass or less, more preferably 15% by mass or less, from the viewpoint of compatibility with light oil and suppression of precipitation at low temperatures. is there.
Mass ratio of unsaturated fatty acid residue to total of saturated fatty acid residue and unsaturated fatty acid residue in all fatty acid residues in compound (1) [unsaturated fatty acid residue / (saturated fatty acid residue + unsaturated fatty acid residue) )] Is preferably 0.80 or more, more preferably 0.85 or more from the viewpoint of suppressing precipitation at a low temperature, and preferably 0.99 or less from the viewpoint of ease of production of the compound (1). .

Compound (1) may be a commercially available product, or may be produced by a conventionally known method, for example, a method of esterifying glycerin and a fatty acid.
Compound (1) is preferably one or more compounds selected from monoesters and diesters of the fatty acid and glycerin.

The amount of the monoester in the compound (1) is preferably 40% by mass or more, more preferably 43% by mass or more, still more preferably 45% by mass or more, and further preferably 50% by mass or more from the viewpoint of excellent lubricity. From the viewpoint of suppressing precipitation at low temperature, it is preferably 90% by mass or less, more preferably 70% by mass or less, still more preferably 65% by mass or less, still more preferably 60% by mass or less, and further preferably 55% by mass or less. . The position of the group —COR ^{1 in} the monoester may be either the 1-position, the 2-position or the 3-position of glycerin.
In the compound (1), the mass ratio of monoester to the total of monoester and diester [monoester / (monoester + diester)] is preferably 0.40 or more, more preferably 0, from the viewpoint of excellent lubricity. .43 or more, more preferably 0.45 or more, further preferably 0.50 or more, and from the viewpoint of low temperature resistance, preferably 0.90 or less, more preferably 0.70 or less, and even more preferably 0.65 or less. More preferably, it is 0.60 or less, more preferably 0.55 or less.

  In the light oil additive of the present invention, the content of the compound (1) is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and further preferably 97% from the viewpoint of lubricity. From the viewpoint of low temperature resistance, it is preferably 99.95% by mass or less, more preferably 99.6% by mass or less, and further preferably 99.2% by mass or less.

In the compound (1), the group -COR ¹ is more preferably a fatty acid residue derived from tall fatty acid from the viewpoint of fatty acid composition, availability, lubricity and compatibility with light oil.
Although the tall fatty acid is sometimes referred to as tall oil fatty acid, it is referred to as tall fatty acid in this specification. Although the tall fatty acid differs depending on the raw material pine, etc., it is generally composed mainly of oleic acid and linoleic acid, and preferably contains some palmitic acid, stearic acid, linolenic acid, and rosin acid.

The composition of the tall fatty acid is as follows.
The total amount of palmitic acid and stearic acid is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and still more preferably 1.0% by mass or more from the viewpoint of availability. From the point of suppression of precipitation at, preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 2% by mass or less. The total amount of oleic acid and linoleic acid is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more from the viewpoint of lubricity, and from the viewpoint of availability, Is 90% by mass or less, more preferably 80% by mass or less.
The mass ratio of linoleic acid to the sum of oleic acid and linoleic acid [linoleic acid / (oleic acid + linoleic acid)] is preferably 0.45 or more, more preferably 0.50, from the viewpoint of suppressing precipitation at low temperatures. From the viewpoint of availability, it is preferably 0.75 or less, more preferably 0.65 or less, and still more preferably 0.60 or less.

[Ingredient (B)]
The component (B) polyglycerol fatty acid monoester used in the present invention is a monoester of polyglycerol and a fatty acid. The degree of polymerization of glycerin in the polyglycerin constituting the polyglycerin fatty acid monoester is 2 or more, and is 9 or less, preferably 5 or less, more preferably 4 or less, from the viewpoint of lubricity and low temperature resistance of the light oil additive. More preferably, it is 3 or less, more preferably 2. Two or more polyglycerol fatty acid monoesters may be used in combination.

  The hydroxyl value (unit: mgKOH / g) of the polyglycerol is 1,000 or more, preferably 1,300 or more, from the viewpoint of lubricity and compatibility with light oil. From the viewpoint of low temperature resistance, it is preferably 1,400 or less. The hydroxyl value of polyglycerol refers to the value determined by the method described in the examples.

The number of carbon atoms of the fatty acid constituting the polyglycerol fatty acid monoester is 10 or more, preferably 14 or more, from the viewpoint of compatibility with light oil, and preferably 22 or less, from the viewpoint of suppressing precipitation at low temperatures, preferably Is 20 or less.
Examples of the fatty acids include saturated fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, icosanoic acid, and behenic acid; monounsaturated fatty acids such as oleic acid; linoleic acid, α-linolenic acid, γ- Examples include dihydric or higher polyunsaturated fatty acids such as linolenic acid and 5,9,12-octadecatrienoic acid; fatty acids derived from natural fats and oils such as tall fatty acid, soybean fatty acid, palm fatty acid and rapeseed fatty acid. The fatty acid is preferably oleic acid, linoleic acid or tall fatty acid from the viewpoint of compatibility with the compound (1) and low temperature resistance.

The fatty acid constituting the polyglycerol fatty acid monoester is at least one selected from saturated fatty acids and unsaturated fatty acids, and preferably contains unsaturated fatty acids. The mass ratio of unsaturated fatty acid to the total of saturated fatty acid and unsaturated fatty acid [unsaturated fatty acid / (saturated fatty acid + unsaturated fatty acid)] is preferably 0.80 or more, more preferably from the viewpoint of suppression of precipitation at low temperature. From the viewpoint of ease of production of the polyglycerol fatty acid monoester, it is preferably 0.99 or less.
The number of carbon atoms of the unsaturated fatty acid is preferably 18 or more from the viewpoint of lubricity and availability, and from the same viewpoint, it is 22 or less, preferably 20 or less, and more preferably 18. The carbon number of the saturated fatty acid is 10 or more from the viewpoint of lubricity and low temperature resistance, preferably 12 or more, and from the same viewpoint, preferably 18 or less, more preferably 16 or less, and still more preferably 14 or less. is there.
Especially, it is preferable that the fatty acid which comprises polyglycerol fatty acid monoester is said tall fatty acid from a viewpoint of the low temperature tolerance of a light oil additive, and lubricity. The preferred tall fatty acid composition is as described above.

  The hydroxyl value (unit: mg KOH / g) of the polyglycerol fatty acid monoester is preferably 200 or more, more preferably 300 or more, and still more preferably 350 or more, from the viewpoint of lubricity and compatibility with light oil. And from a viewpoint of low temperature tolerance, Preferably it is 650 or less, More preferably, it is 550 or less, More preferably, it is 450 or less. The hydroxyl value of the polyglycerol fatty acid monoester can be measured by a general oil analysis method such as the method described in JIS K0070 7.2.

  In the light oil additive of the present invention, the content of the polyglycerol fatty acid monoester relative to 100 parts by mass of the compound (1) is 0.05 parts by mass or more, preferably 0.4 parts by mass or more, from the viewpoint of lubricity. More preferably, it is 0.8 parts by mass or more, and from the same viewpoint, it is 9 parts by mass or less, preferably 6 parts by mass or less, more preferably 3 parts by mass or less, and further preferably 2.5 parts by mass or less. .

  As the polyglycerol fatty acid monoester, a commercially available product may be used, and the polyglycerol fatty acid monoester may be produced by an ester exchange reaction between fat and oil and polyglycerol, an esterification reaction between fatty acid and polyglycerol, or the like.

[Light oil additive]
The light oil additive of the present invention can be obtained, for example, by appropriately heating and stirring and mixing the component (A), the component (B), and other components as necessary. The light oil additive thus obtained has excellent lubricity, low cloud point and pour point, and excellent low temperature resistance. The light oil additive of the present invention is more preferably a light oil additive for low-sulfur light oil from the viewpoint of remarkably expressing the effect.

The cloud point of the light oil additive of the present invention is preferably −10 ° C. or lower, more preferably −14 ° C. or lower. The cloud point can be measured by the method described in the examples.
The pour point of the light oil additive of the present invention is preferably −20 ° C. or lower, more preferably −25 ° C. or lower. The pour point can be measured by the method described in the examples.

  The light oil additive of the present invention may contain glycerin. The content of glycerin in the light oil additive is preferably 2.5% by mass or less, more preferably 1.0% by mass or less, from the viewpoint of lubricity. The light oil additive of the present invention may contain a triester of a fatty acid and glycerin. The content of the triester in the light oil additive is preferably 1% by mass or more, more preferably 4% by mass or more from the viewpoint of ease of production, and preferably 20% by mass or less from the viewpoint of lubricity. Preferably it is 15 mass% or less.

  The light oil additive of the present invention may further contain various additives usually used for light oil. Examples of the additive include a combustion improver such as a smoke inhibitor, an antioxidant, a conductivity improver, a metal deactivator, an anti-icing additive, a cetane improver, a surfactant, a dispersant, an air intake system cleaner, Corrosion inhibitors, demulsifiers, top cylinder lubricants, dyes and the like can be mentioned.

[Light oil composition]
The light oil composition of the present invention contains light oil and the light oil additive. The content of the light oil additive in the light oil composition is preferably 0.001% by mass or more, more preferably 0.005% by mass or more from the viewpoint of lubricity, and preferably 0 from the viewpoint of physical properties of the light oil fuel. .1% by mass or less, more preferably 0.05% by mass or less.
The light oil used in the present invention is preferably a low sulfur light oil from the viewpoint of exerting the effects of the present invention, and the sulfur content in the light oil is preferably 0.01% by mass or less, more preferably 0.005% by mass or less. . The sulfur content can be measured by a radiation excitation method described in JIS K2541. As low sulfur gas oil, hydrodesulfurization equipment, such as hydrodesulfurization of gas oil fraction obtained by atmospheric distillation of crude oil at high reaction temperature, hydrodesulfurization at high hydrogen partial pressure, high activity And the like obtained by a method using a hydrodesulfurization catalyst having the following.

  The light oil composition of the present invention may contain various commonly used additives. These additives include, for example, combustion improvers such as smoke suppressants, antioxidants, conductivity improvers, metal deactivators, anti-icing additives, cetane improvers, surfactants, dispersants, and air intake system cleaners. Agents, corrosion inhibitors, demulsifiers, top cylinder lubricants, dyes and the like.

[Measurement and evaluation method]
(1) Measurement of glycerin ester composition 0.25 g of a sample was dissolved in 100 mL of tetrahydrofuran (hereinafter also referred to as “THF”) and used as a sample solution for measurement. Gel permeation chromatography method (apparatus: “HLC-8220GPC” manufactured by Tosoh Corporation, detector: RID attached to the apparatus, column: “G2000HXL + G1000HXL” manufactured by Tosoh Corporation, column temperature: 40 ° C., flow rate: 1 mL / min, solvent: THF, sample solution amount: 100 μL), using polystyrene as a standard substance. The area ratio of each peak with respect to the total of each peak area showing monoester, diester and triester was defined as the mass composition ratio in the sample.

(2) Measurement of fatty acid composition Fatty acid methyl ester was prepared according to "Preparation Method of Fatty Acid Methyl Ester (2.4.4.1.-1996)" in "Standard Oil Analysis Test Method" edited by Japan Oil Chemists' Society. Oil samples were obtained from American Oil Chemists. It was measured by the GLC method described in Society Official Method Ce 1-96.
<GLC analysis conditions>
Equipment: “Agilent 6890 Series” manufactured by Agilent Technologies
Column: “CP-SIL88 (100 m × 0.25 mm × 0.2 μm)” manufactured by Varian
Carrier gas: He
Flow rate: 1.0 mL / min
Injector: Split (1: 200), 250 ° C.
Detector: FID, 250 ° C
Oven temperature: Hold at 174 ° C for 50 minutes, then heat up to 220 ° C at 5 ° C / minute and hold for 25 minutes

(3) Hydroxyl value of polyglycerol The hydroxyl value of polyglycerol constituting the polyglycerol fatty acid monoester was calculated from the following formula using the degree of glycerol polymerization (n) of polyglycerol.
Hydroxyl value (unit: mgKOH / g)
= 56.1 × (n + 2) / {(92.1-18.0) × n + 18.0} × 1000

(4) Measurement of cloud point and pour point Measurement was performed using an automatic pour point / cloud point tester ("MPC-102L type" manufactured by Tanaka Scientific Instruments). The cloud point was measured at a measurement interval of 1 ° C. by a method based on ASTM D6749. The pour point was measured at a measurement interval of 1 ° C. by a method based on ASTM D2500. The smaller the cloud point and pour point, the better the low temperature resistance.

(5) Measurement of friction coefficient Using a pendulum type oil friction tester (manufactured by Shinko Engineering Co., Ltd.), initial amplitude: 0.5 Rad, proportionality constant: 3.2, stop amplitude: 0.1 Rad, load: 300 gf (2. 9N), amplitude period: 4 seconds, contact surface pressure: 1087 N / mm ² , sample temperature: 25 ° C. The smaller the coefficient of friction, the better the lubricity.

Production Example 1 [Preparation of Glycerol Tol Fatty Acid Ester]
100 g of a carrier (“Dulite A-568” manufactured by Rohm & Haas) and 1000 mL of 0.1N NaOH aqueous solution were stirred and mixed for 1 hour, and the carrier was recovered by filtration. To the carrier was added 1000 mL of ion exchange water, stirred for 1 hour, and the carrier was recovered by filtration. To the carrier, 1000 mL of 500 mM acetate buffer (pH 5) was added, stirred for 1 hour, and the carrier was recovered by filtration. As a pH equilibration operation, 1000 mL of 50 mM acetate buffer (pH 5) was added to the support, stirred for 2 hours, and the support was recovered by filtration. The pH equilibration operation was repeated twice in total. Ethanol (500 mL) was added to the carrier, stirred for 30 minutes, and the carrier was recovered by filtration. To the carrier, 100 g of soybean fatty acid and 400 mL of ethanol were added, stirred for 30 minutes, and the carrier was recovered by filtration. As an ethanol removal operation, 500 mL of 50 mM acetate buffer (pH 5) was added to the carrier, stirred for 30 minutes, and the carrier was recovered by filtration. The ethanol removal operation was repeated four times in total. To the carrier, an enzyme solution obtained by uniformly mixing 100 g of lipase (“Lipase G“ Amano ”50” manufactured by Amano Enzyme Co., Ltd.) and 900 mL of 50 mM acetate buffer (pH 5) in advance was added and stirred for 2 hours. The carrier was recovered by filtration. To the carrier, 1000 mL of 50 mM acetate buffer (pH 5) was added, stirred for 30 minutes, and the carrier was recovered by filtration. All the above operations were performed at 20 ° C. 100 g of soybean fatty acid was added to the carrier, and the mixture was dehydrated under reduced pressure until reaching a pressure of 400 Pa while stirring at 40 ° C., and the carrier was recovered by filtration. As a fatty acid removal operation, 500 mL of hexane was added to the carrier, stirred at 20 ° C. for 30 minutes, and the carrier was recovered by filtration. The fatty acid removal operation was repeated three times in total. The carrier was desolvated using an evaporator at 40 ° C. and a pressure of 1300 Pa for 1 hour, and then dried at 40 ° C. and a pressure of 1300 Pa for 15 hours to obtain an immobilized enzyme.
A 4-necked flask equipped with a half moon wing (Φ90 mm × H25 mm) was charged with 388 g of tall fatty acid (“SYLFAT 2LT” manufactured by Arizona Chemical Co.) and 60 g of immobilized enzyme, and immersed in a constant temperature water bath adjusted to 40 ° C. While stirring at 400 r / min, 212 g of glycerin (0.6 mol with respect to tall fatty acid) was charged, the degree of vacuum was adjusted to 400 Pa, and the esterification reaction was carried out for 10 hours. The obtained reaction mixture was taken out and centrifuged to separate and remove undissolved glycerin and immobilized enzyme from the oil layer. Then, using a wipe film evaporator (“2-03 type” manufactured by Shinko Environmental Solution), deglycerin was performed at 100 ° C. and deoxidation was performed at 160 ° C. to obtain glyceryl tol fatty acid ester. As a result of measuring the obtained glycerol tol fatty acid ester by the method described in “(1) Measurement of glycerol ester composition”, it was 46 mass% monoester, 42 mass% diester, and 12 mass% triester.
The raw tall fatty acids were measured by the method described in “(2) Measurement of fatty acid composition”. As a result, 0.4% by mass of palmitic acid, 1.2% by mass of stearic acid, 30.3% by mass of oleic acid, linole The acid content was 42.7% by mass, the other chain unsaturated fatty acid was 18.0% by mass, the rosin acid was 1.8% by mass, and the unsaponified product was 2.0% by mass.

Production Example 2 [Preparation of polyglycerol fatty acid monoester]
Polyglycerol fatty acid monoester (hereinafter also referred to as “PGE”) 1 was prepared by the method shown below. As diglycerin, the thing obtained by distilling and purifying "Diglycerol (diglycerin purity of 80% or more)" manufactured by Tokyo Chemical Industry, having a diglycerin purity of 99% or more by gas chromatography was used.
The diglycerin 250.0 g and tall fatty acid (“SYLFAT 2LT” manufactured by Arizona Chemical Co.) 433.3 g were charged into a 1 L four-necked flask equipped with a half moon wing (Φ90 mm × H25 mm). The gas phase portion in the 1 L four-necked flask was replaced with nitrogen, and thereafter, the reaction was performed while flowing nitrogen through the liquid space at a flow rate of 20 mL / min. While stirring at 400 r / min, the temperature was raised to 250 ° C. over about 30 minutes, and an esterification reaction was carried out at 250 ° C. for 3 hours. Subsequently, it cooled to 70 degreeC over about 20 minutes, and obtained the monoester (PGE1) of diglycerin and tall fatty acid.

  Commercially available PGE2-7 other than PGE1 were used. In Table 1, the polymerization degree of glycerol, the kind of constituent fatty acid, and the hydroxyl value of polyglycerol in PGE1, PGE2-5 (manufactured by Sakamoto Pharmaceutical Co., Ltd.) and PGE6-7 (manufactured by Taiyo Kagaku Co., Ltd.) are shown.

[Preparation of light oil additive] Examples 1-6 and Comparative Examples 1-2
PGE1 to 7 were added to the glyceryl tol fatty acid ester obtained in Production Example 1 and stirred and mixed at 70 ° C. for 30 minutes to prepare a light oil additive. Content of PGE1-7 with respect to 100 mass parts of component (A) is as having shown in Table 1.

Examples 7-10
A light oil additive was prepared in the same manner as in Example 1 except that PGE5 was added to the glyceryl tol fatty acid ester obtained in Production Example 1, respectively. The content of PGE5 with respect to 100 parts by mass of component (A) is as shown in Table 2.

〔Evaluation test〕
About the light oil additive prepared by the Example and the comparative example, the cloud point, the pour point, and the friction coefficient were measured. The results are shown in Tables 1 and 2. In Tables 1 and 2, Example 6 and Example 10 are reference examples.

As is apparent from Tables 1 and 2, by adding a predetermined amount of a predetermined polyglycerin fatty acid monoester to the glyceryl tol fatty acid ester, the cloud point of the light oil additive was greatly reduced and the pour point was also decreased. . Example 1 to which a monoester (PGE1) of diglycerin and tall fatty acid was added also showed good lubricity.
On the other hand, PGE7 having a glycerol polymerization degree of 10 was not dissolved in glycerol tol fatty acid ester, and a uniform light oil additive could not be obtained.

Claims (5)

The following components (A) and (B):
(A) Compound represented by the following general formula (1)

Wherein X ¹ , X ² and X ³ are one or more selected from a hydrogen atom and a group —COR ¹ , and at least one of X ¹ , X ² and X ³ is a hydrogen atom, X ¹ , At least one of X ² and X ³ is a group —COR ¹ , and the group —COR ¹ represents a fatty acid residue having 10 to 22 carbon atoms.
(B) degree of polymerization of glycerol is diglycerol and the carbon number of 2 contain diglycerol fatty acid monoester is a monoester of a 10 to 22 fatty acid, and component (A) component with respect to 100 parts by weight (B) Oil oil additive whose content is 0.3 to 3 parts by mass. It said components (B) light oil additive of claim 1 wherein the fatty acid constituting the diglycerol fatty acid monoester is a tall fatty acid. The diesel oil additive according to claim 1 or 2, wherein the group -COR ¹ in the general formula (1) is a tall fatty acid residue. The light oil composition containing the light oil additive of any one of Claims 1-3 . The gas oil composition according to claim 4 , wherein the sulfur content in the gas oil is 0.01 mass% or less.