JPH10245574A - Pour improver for fuel oil and fuel oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an improver used to improve the low-temperature pour of a fuel oil by mixing a product obtained by grafting an unsaturated dicarboxylic ester onto an ethylene/vinyl saturated carboxylate copolymer with a triester of a glycerol/alkylene oxide adduct with a saturated fatty acid. SOLUTION: This improver comprises a product (A) obtained by grafting di-2-ethylhexyl maleate onto an ethylene/vinyl acetate copolymer having a number-average molecular weight of 2,000-10,000 and a vinyl acetate content of 10-25wt.% and a triester (B) of a glycerol/ethylene oxide adduct with stearic acid in an A/B ratio of 1/5 to 5/1 by weight. If required, it may further formulate at least one compound selected from the group consisting of an ethylene/ vinyl saturated carboxylate copolymer having a saturated carboxylic acid content of 30-45wt.%, a 12-22C alkyl (meth)acrylate polymer and an ethylene/ propylene copolymer having a propylene content of 20-70wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an additive for improving the flowability of fuel oil and a fuel oil containing the same.

[0002]

2. Description of the Related Art When a middle distillate oil such as diesel fuel oil or heavy fuel oil A is exposed to a low temperature in winter or in a cold region, paraffin wax or a wax-like substance contained therein is precipitated, and a fuel piping system is formed. Clogging of the filter, and solidification of the fuel in the piping system causes problems such as an inability to start the engine and the combustion device and a stop of the engine.

[0003] In order to solve these problems relating to fluidity at low temperatures, a number of methods have heretofore been proposed for adding a vinyl ester copolymer of ethylene-saturated carboxylic acid to fuel oil. For example, it is described in JP-B-39-20069, JP-B-48-23165, and JP-A-59-136391. In addition, an unsaturated dicarboxylic acid ester graft adduct of an ethylene-vinyl carboxylate copolymer and a method of adding the adduct in combination with an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer or the like [ JP-B-58-39472], perfect esters of polyoxyalkylene ethers of alkanetriols with linear saturated fatty acids, and those esters with ethylene-vinyl acetate copolymers, ethylene-acrylate copolymers, and long-chain alkyl groups (Japanese Patent Publication No. 2-51477), a method of adding a fatty acid ester of polyoxyalkylene glycol and these esters to an ethylene-vinyl acetate copolymer. Addition method in combination [JP-A-57-177092], trivalent or more Polyhydric alcohol or a method of adding an incomplete ester of an alkylene oxide adduct and a fatty acid of the partial ester of [JP 61-181892] have been proposed.

[0004]

However, in recent years, the demand for middle distillate oil has been increasing, and as a result of this demand, the distillation properties of diesel fuel oil and heavy oil A have narrow distillation boiling ranges. Has become a narrow cut middle distillate. In addition, hydrodesulfurization is performed to reduce the sulfur content in light oil, which tends to further narrow the distillation properties. In order to improve the fluidity of these middle distillate oils at low temperatures, the conventionally used method of adding an ethylene-vinyl acetate copolymer is insufficient to improve the fluidity, and the precipitated wax precipitates. In some cases, problems such as filter clogging may occur. A method of adding together a triester of a polyoxyalkylene ether of alkanetriol with a linear saturated fatty acid; and a (meth) acrylic acid copolymer containing a long-chain alkyl group in combination with ethylene glycol. The method of adding an unsaturated dicarboxylic acid ester adduct of a vinyl carboxylate copolymer has little sedimentation of precipitated wax, but has little effect of improving fluidity at low temperatures.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on this problem and found that an unsaturated dicarboxylic acid ester adduct of an ethylene-saturated carboxylic acid vinyl ester copolymer and an alkylene oxide adduct of glycerin have been obtained. By adding together a triester of a saturated fatty acid with
It has been found that the fluidity at low temperatures can be improved and the sedimentation of precipitated wax can be reduced. That is, the present invention
Ethylene-saturated carboxylic acid vinyl ester copolymer (a
1) an unsaturated dicarboxylic acid ester (a2) graft adduct (A), a triester (B) of an alkylene oxide adduct of glycerin (b1) and a saturated fatty acid (b2), and if necessary, a saturated carboxylic acid Ethylene-saturated carboxylic acid vinyl ester copolymer (C) having a content of 30 to 45% by weight, alkyl (meth) acrylate polymer (D) having an alkyl group having 12 to 22 carbon atoms, propylene content of 20 to 45% by weight. It is a fluidity improving additive for fuel oil comprising at least one compound selected from the group consisting of 70% by weight of ethylene-propylene copolymer.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a specific example of the ethylene-saturated carboxylic acid vinyl ester copolymer (a1) for forming the graft adduct (A) of the present invention, the number average molecular weight is 500 to 500.
20,000, an ethylene-saturated carboxylic acid vinyl ester copolymer having a saturated carboxylic acid vinyl ester content of 5 to 40% by weight. Specific examples of the saturated vinyl carboxylate include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl neononanoate, and vinyl neodecanoate. Preferably vinyl acetate is 10 to 2
5% by weight and has a number average molecular weight of 2,000 to 10,000.
00 ethylene-vinyl acetate copolymer. When the content of the saturated vinyl carboxylate is less than 5% by weight, the solubility in diesel gas oil or the like becomes low, and when it exceeds 40% by weight, the precipitated wax tends to settle. On the other hand, if the number average molecular weight is less than 500, the effect of improving the fluidity at low temperatures tends to deteriorate, and if the number average molecular weight exceeds 20,000, the viscosity becomes high and practicality is lost.

Specific examples of the unsaturated dicarboxylic acid ester (a2) forming the graft adduct (A) include:
Monoester or diester of an unsaturated dicarboxylic acid such as maleic acid, fumaric acid, citraconic acid, itaconic acid and an alcohol having 4 to 22 carbon atoms. Preferably, dibutyl maleate, diisobutyl maleate, dioctyl maleate, di-2-ethylhexyl maleate, dioctadecyl maleate, dieicosyl maleate, dibutyl fumarate, diisobutyl fumarate, dioctyl fumarate, di-2-fumarate Examples thereof include ethylhexyl, dioctadecyl fumarate, and dieicosyl fumarate. Particularly preferred are di-2-ethylhexyl maleate and di-2-ethylhexyl fumarate. When the carbon number of the alcohol is less than 4, the precipitated wax tends to settle, and when it exceeds 22, the effect of improving the fluidity at low temperatures tends to deteriorate.

The graft adduct (A) is composed of an ethylene-saturated carboxylic acid vinyl ester copolymer (a1), an unsaturated dicarboxylic acid ester (a2) and a small amount of a radical generating catalyst (organic or inorganic peroxide, azo compound). ) Is uniformly mixed and usually heated to 100 ° C. or higher. The reaction ratio of (a1) and (a2) is 2/1 to 1/50
(Weight ratio), preferably 1/1 to 1/3 (weight ratio). From the ratio of (a1) / (a2) to 2/1 (a
When 1) increases, the solubility tends to be insufficient. Also,
If (a1) is less than 1/5, the fluidity improving effect tends to deteriorate.

The triester (B) of the alkylene oxide adduct of glycerin (b1) and the saturated fatty acid (b2) of the present invention is a triester of the alkylene oxide adduct of glycerin (b1) and the saturated fatty acid (b2). However, (b1), the monoester and diester may remain as long as they do not adversely affect, and their total in the whole ester is usually less than 10% by weight, preferably 5% by weight.
% By weight. Specific examples of the glycerin alkylene oxide adduct (b1) that forms (B) of the present invention include glycerin ethylene oxide adduct, propylene oxide adduct, and 1,2-butylene oxide adduct. The addition mole number of the alkylene oxide is 1 to 15, and two or more kinds of addition products having different addition mole numbers of the alkylene oxide may be used in combination. Preferably, 3 to 10 moles of ethylene oxide adduct of glycerin and two or more kinds of adducts having different addition mole numbers within the range of this addition mole number are blended. Further, specific examples of the saturated fatty acid (b2) forming (B) include palmitic acid, stearic acid, arachiic acid, behenic acid, lignoceric acid, serotinic acid, montanic acid, and melicic acid. Preferred are stearic acid, arachiic acid, behenic acid, and lignoceric acid, which form linear saturated alkyl residues. These may be used alone or as a mixture. For example, a mixed fatty acid obtained by hydrogenating a fatty acid obtained by hydrolyzing a natural fat or oil such as beef tallow can be used as it is.

The content of (A) and (B) in the additive of the present invention is at least 20% by weight, preferably at least 50% by weight. If it is less than 20% by weight, precipitated wax tends to settle. (A) / (B) is 1/5 to 5/1 (weight ratio), preferably 2/1 to 1/2. When the ratio (A) is larger or smaller than this ratio, the effect of improving the fluidity at low temperatures tends to deteriorate.

In the present invention, if necessary, (A) and (B) may further have a saturated carboxylic acid vinyl ester content of 30.
Ethylene-saturated carboxylic acid vinyl ester copolymer (C) having an alkyl group of 12 to 2% by weight.
2, an alkyl (meth) acrylate polymer (D),
One or more compounds selected from the group consisting of ethylene-propylene copolymers having a propylene content of 30 to 70% by weight can be used in combination.

As a specific example of (C), the number average molecular weight is 5
It is an ethylene-saturated carboxylic acid vinyl ester copolymer having a molecular weight distribution of usually not more than 3, preferably not more than 3, preferably not more than 2.5. Further, as a vinyl ester of a saturated carboxylic acid, at least one selected from the group consisting of vinyl acetate, vinyl propionate, vinyl butyrate, vinyl neononanoate and vinyl neodecanoate, usually 25 to 50% by weight,
An ethylene-saturated carboxylic acid vinyl ester copolymer having preferably 30 to 45% by weight and a methyl terminal side chain per 100 main chain methylene groups (hereinafter referred to as a degree of branching) of 2 to 7 other than a methyl group of an acetyl group. is there. The degree of branching can be measured by a nuclear magnetic resonance method described in “Journal of the Chemical Society of Japan”, 1980, No. 1, pp. 74-78.

Specific examples of the alkyl (meth) acrylate polymer (D) having 12 to 22 carbon atoms in the side chain alkyl group include methacrylate or a methacrylate having a hydrocarbon group having 12 to 22 carbon atoms in the side chain alkyl group. Acrylate homopolymer or copolymer (weight average molecular weight 1,000 to 1,000,
000). Preferably, it has 14 to 18 carbon atoms.
Is a methacrylate or acrylate having an alkyl group having a weight average molecular weight of 5,000 to 100,000.

A specific example of the ethylene-propylene copolymer (E) having a propylene content of 30 to 70% by weight has a weight average molecular weight of 5,000 as measured by gel permeation chromatography using polystyrene as a standard.
To 50,000, preferably 20 to 70% by weight, preferably 30 to 50% by weight, of propylene.

[0015] Specific examples of the fuel oil of the present invention include JIS No. 1 gas oil, JIS No. 2 gas oil, and JIS No. 2 light oil obtained by ordinary distillation.
IS No. 3 gas oil, JIS special No. 3 gas oil; desulfurized gas oil produced from normal crude oil through a hydrodesulfurization step; obtained by blending this hydrodesulfurized gas oil with a straight run gas oil (light oil before the hydrodesulfurization step) JIS No. 1 gas oil obtained from gas oil fraction, J
IS2 light oil, JIS3 light oil, JIS special No.3 light oil. Further, heavy fuel oil A produced by mixing the above various light oil fractions with distillation residue, extract and the like can be mentioned. Preferably, JIS No. 2 gas oil, JIS No. 3 gas oil, J
IS special No. 3 gas oil, and particularly preferably, a sulfur content obtained by blending hydrodesulfurized gas oil and straight-run gas oil is 0.2%.
JIS No. 2 light oil, JIS No. 3 light oil, JIS
Special No. 3 light oil. The fluidity improver of the present invention is used by adding 0.005 to 0.1% by weight to the above fuel oil.

The fuel oil of the present invention may contain other known additives. These known additives include detergents (ethylene oxide adduct of butylamine, ethylene oxide adduct of butanol), lubricity improvers (glycerin monolinoleate, dimer acid, etc.), antioxidants and the like.

[0017]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The fluidity of fuel oil at low temperature is determined by the pour point (JIS K22
69), and filter clogging temperature (JIS K228)
8). The lower the pour point and the filter plugging temperature, the better the fluidity at low temperatures. The sedimentation degree of the precipitated wax was measured by weighing 100 ml of the sample oil in a 100 ml measuring cylinder with a stopper, and visually observing the degree of sedimentation of the precipitated wax after standing at a temperature of 2 ° C. below the cloud point of the sample oil for 15 hours. Then, the capacity of the wax portion was read and evaluated. Capacity 1
It was judged that the closer to 00 ml, the less the sedimentation. Further, the number average molecular weight was measured by a vapor pressure osmosis method, and the weight average molecular weight was measured by gel permeation chromatography using polystyrene as a standard sample. The triester content was calculated from the area of the gel permeation chromatogram (GPC). Further, the molecular weight of the ethylene oxide adduct of glycerin was calculated from the hydroxyl value, and the molecular weight of the fatty acid was calculated from the acid value, and the reaction molar ratio was calculated.

Table 1 shows the properties of the middle distillate used for the evaluation.

[0019]

[Table 1]

Production Example 1 [Production of di-2-ethylhexyl maleate 1/2 adduct of ethylene-vinyl acetate (10%) copolymer] Ethylene having a vinyl acetate content of 10% by weight and a number average molecular weight of 5,000. 100 g of vinyl acetate copolymer, di-2-maleic acid
200 g of ethylhexyl and 2% by weight of dicumyl peroxide corresponding to 2% by weight of the total amount of ethylene-vinyl acetate copolymer and di-2-ethylhexyl maleate were charged into the reaction vessel,
Nitrogen gas is heated and melted at 100 ° C. under aeration, and mixed until uniform. Then, the temperature was raised to 150 ° C. and an addition reaction was carried out for 3 hours. The ethylene-vinyl acetate copolymer maleate di-2
-Ethylhexyl 1/2 adduct (SG-1) was prepared. The unreacted homopolymer of di-2-ethylhexyl maleate and di-2-ethylhexyl maleate was extracted with acetone, and the addition rate of the added di-2-ethylhexyl maleate added was 75%. . Production Example 2 [Production of di-2-ethylhexyl maleate 1/1 adduct of ethylene-vinyl acetate (10%) copolymer] In Production Example 1, the amount of di-2-ethylhexyl maleate added was 10
A di-2-ethylhexyl maleate 1/1 adduct of an ethylene-vinyl acetate copolymer (SG-2) was prepared in the same manner as in Production Example 1 except that the temperature was changed to 0 ° C. Addition rate is 8
5%. Production Example 3 [Production of dioctadecyl maleate 1/2 adduct of ethylene-vinyl acetate (10%) copolymer] Production Example 1 was repeated except that di-2-ethylhexyl maleate was changed to dioctadecyl maleate. In the same manner as in Example 1, the ethylene-vinyl acetate copolymer dioctadecyl maleate 1 /
A 2-adduct (SG-3) was made. The addition rate was 78%. Production Example 4 [Production of di-2-ethylhexyl maleate 1/2 adduct of ethylene-vinyl acetate (20%) copolymer] The ethylene-vinyl acetate copolymer of Production Example 1 was prepared by adding a vinyl acetate content of 20% by weight. In the same manner as in Production Example 1, except that the ethylene-vinyl acetate copolymer having a number average molecular weight of 10,000 was used, a di1 / 2 maleate adduct of an ethylene-vinyl acetate (20%) copolymer (SG- 4) was prepared. Addition rate is 7
6%. Production Example 5 [Production of dibutyl maleate 1/2 adduct of ethylene-vinyl acetate (25%) copolymer]
Production Example 1 was repeated except that the vinyl acetate copolymer was changed to an ethylene-vinyl acetate copolymer having a vinyl acetate content of 25% by weight and a number average molecular weight of 10,000 and di-2-ethylhexyl maleate to dibutyl fumarate. In the same manner, dibutyl maleate 1/2 adduct (SG-5) of an ethylene-vinyl acetate (25%) copolymer was prepared. Addition rate is 8
It was 0%. Production Example 6 [Production of behenic acid ester of glycerin ethylene oxide 5 mol adduct] 1 mol of glycerin ethylene oxide 5 mol adduct, 3 mol of behenic acid, 2 mol of glycerin ethylene oxide adduct and behenic acid 0.5% by weight of paratoluenesulfonic acid is charged into a reaction vessel, and heated to 150 to 160 ° C. under a nitrogen gas atmosphere, and reacted for 6 hours. Behenic acid ester of ethylene oxide 5 mol adduct of glycerin (SE-1) It was created. Acid value2.
5, hydroxyl value was 2.5. Further, the triester content by GPC was 96.5% by weight. Production Example 7 [Production of stearic acid ester of glycerin propylene oxide 5 mol adduct] Production Example 5 except that ethylene oxide 5 mol adduct was changed to propylene oxide 5 mol adduct and behenic acid was changed to stearic acid in Production Example 5. 5
A stearic acid ester (SE-2) of a 5 mol propylene oxide adduct of glycerin was produced in the same manner as in the above. The acid value was 1.6 and the hydroxyl value was 1.5. Also, GP
The triester content by C was 95.5% by weight. Production Example 8 [Production of behenic acid ester of ethylene oxide 10 mol adduct of glycerin] In the same manner as in Production Example 5, except that ethylene oxide 5 mol adduct was changed to 10 mol adduct, ethylene glycerin ethylene was added. A behenic acid ester (SE-3) of an oxide 5 mol adduct was produced.
The acid value was 2.0 and the hydroxyl value was 1.5. The triester content by GPC was 95.0% by weight.

Comparative Production Example 1 [Production of behenic acid partial ester of glycerin ethylene oxide 5 mol adduct] In Production Example 5, 1 mol of ethylene oxide 5 mol adduct was added to 5 mol adduct and 3 mol of behenic acid was added. A behenic acid ester (RE-1) of glycerin ethylene oxide 5 mol adduct was produced in the same manner as in Production Example 5 except that the amount was changed to 1 mol. Acid value 0.3,
The hydroxyl value was 170. Further, the triester content by GPC was 10.0% by weight. Comparative Production Example 2 [Production of stearic acid ester of glycerin] Production Example 1
A glycerin stearic acid ester (RE-2) was produced in the same manner as in Production Example 5, except that the glycerin ethylene oxide 5 mol adduct was changed to glycerin and the behenic acid 3 mol to stearic acid 1 mol. Acid value 0.2,
The hydroxyl value was 318. Further, the triester content by GPC was 8.0% by weight.

Examples 1 to 7 and Comparative Examples 1 to 6 (A)
(B) is blended, and as a 50% by weight solution of white kerosene, the fluidity improving additives for fuel oils of Examples 1 to 7 (S1 to S7)
It was created. Similarly, as shown in Table 3, fluidity improving additives (R1 to R4) for fuel oils of Comparative Examples 1 to 4 were prepared.

[0023]

[Table 2] (The numbers represent parts by weight)

[0024]

[Table 3] (The numbers represent parts by weight)

OCP: an ethylene-propylene copolymer having a propylene content of 40% by weight and a weight average molecular weight of 10,000 PMA: the alkyl group is a saturated alkyl group having 14 to 16 carbon atoms, and the weight average molecular weight is 20,000. Polyalkylmethacrylate EVA-1: Ethylene-saturated vinyl carboxylate copolymer having a vinyl acetate content of 35% by weight, a vinyl versatate content of 7% by weight, a number average molecular weight of 3,000 and a degree of branching of 5.1 EVA-2: Vinyl acetate EVA-3: an ethylene-vinyl acetate copolymer having a content of 10% by weight and a number average molecular weight of 5,000 EVA-3: an ethylene-vinyl acetate copolymer having a vinyl acetate content of 20% by weight and a number average molecular weight of 10,000

S1 to S7 and R1 to R4 are evaluated oil A,
A predetermined amount was added to the evaluation oil B, and a pour point (PP) and a filter clogging point (CFPP) were measured. Evaluation oil C
To a predetermined amount, and the degree of sedimentation of the precipitated wax was evaluated. The results are shown in Tables 4 and 5.

[0027]

[Table 4]

[0028]

[Table 5]

As is evident from Table 4, the fluidity improver for fuel oil of the present invention has an excellent effect of improving fluidity at low temperatures and has a low degree of sedimentation of precipitated wax.

[0030]

EFFECTS OF THE INVENTION The fluidity improving additive for fuel oil of the present invention is excellent in fluidity improving effect at low temperature and has little sedimentation of precipitated wax, so that it can be used without causing problems even in cold regions. Production of light oil and heavy oil A becomes easy.

Claims (14)

[Claims] 1. An unsaturated dicarboxylic acid ester (a) of an ethylene-saturated carboxylic acid vinyl ester copolymer (a1)
2) A fluidity improving additive for fuel oil comprising a graft adduct (A) and a triester (B) of an alkylene oxide adduct of glycerin (b1) and a saturated fatty acid (b2). 2. The additive according to claim 1, further comprising an ethylene-saturated vinyl carboxylate copolymer (C) having a saturated vinyl carboxylate content of 30 to 45% by weight, wherein the alkyl group has 12 carbon atoms. For use in combination with one or more compounds selected from the group consisting of an alkyl (meth) acrylate polymer (D) having a molecular weight of 22 to 22 and an ethylene-propylene copolymer (E) having a propylene content of 20 to 70% by weight. Flowability additive. 3. The ethylene-saturated carboxylic acid vinyl ester copolymer (a1) has a number average molecular weight of 500 to 2
The fluidity improving additive for a fuel oil according to claim 1 or 2, which is an ethylene-saturated carboxylic acid vinyl ester copolymer having a vinyl ester content of saturated carboxylic acid of 5 to 40% by weight at 000. 4. The unsaturated dicarboxylic acid ester (a2)
Is a maleic acid or fumaric acid ester, and the fluidity improving additive for a fuel oil according to claim 1. 5. The fluidity improving additive for fuel oil according to claim 1, wherein (a2) is an alkyl ester having 4 to 22 carbon atoms. 6. The fluidity improving additive for a fuel oil according to claim 1, wherein said (a2) is di-2-ethylhexyl maleate or di-2-ethylhexyl fumarate. 7. The (a1) / (a1) of the graft adduct (A)
The fluidity improving additive for fuel oil according to any one of claims 1 to 6, wherein the reaction ratio of (a2) is 2/1 to 1/5 (weight ratio). 8. The fluidity improving additive for a fuel oil according to claim 1, wherein the addition mole number of the alkylene oxide in the alkylene oxide adduct of glycerin (b1) is 1 to 15. 9. The fluidity improving additive for a fuel oil according to claim 1, wherein (b1) is an ethylene oxide adduct. 10. The saturated fatty acid (b2) having 16 to 16 carbon atoms.
The fluidity improving additive for fuel oil according to any one of claims 1 to 9, which is 30 linear saturated fatty acids. 11. The fluidity improving additive for a fuel oil according to claim 1, wherein the sum of (A) and (B) is at least 20% by weight of the whole additive. 12. (A) / (B) is 1/5 to 5/1
The fluidity improving additive for a fuel oil according to any one of claims 1 to 11, which is (weight ratio). 13. A fuel oil containing the fluidity improving additive for a fuel oil according to claim 1. 14. The fuel oil according to claim 13, which has a sulfur content of 0.2% by weight or less.