JPH0366357B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a low temperature fluidity improver, and more particularly to an additive for improving the low temperature fluidity of hydrocarbon fuel oil. Hydrocarbon fuel oils, such as light oil, A heavy oil, etc.
- Because it contains paraffin wax, precipitation of n-paraffin wax often occurs in cold winter regions, resulting in blockage of oil pipes and strainers installed in the fuel supply circuit of internal combustion engines. This causes major problems with the fluidity of fuel oil at low temperatures, such as clogging. To solve this problem, additives commonly called cold flow improvers are used. Various types of low-temperature fluidity improvers have been studied and proposed, including ethylene-vinyl acetate copolymers. For example, the copolymer of ethylenically unsaturated dicarboxylic acid and α-olefin described in JP-A No. 54-157106, and the copolymer of ethylenically unsaturated dicarboxylic acid and α-olefin described in JP-A-50-15005. Long-chain alcohol esters of polymers, and JP-A-54-
Known are aliphatic amine-modified copolymers of ethylenically unsaturated dicarboxylic acids and α-olefins, described in JP 81307. However, these effects are still not sufficient. Recently, a method has been proposed in which a second or third component is added in order to compensate for the effects of the above-mentioned additives. For example, as described in JP-A No. 54-86505, ethylene-
A method in which a second component such as a vinyl acetate copolymer is used in combination, or as described in U.S. Pat. No. 4,210,424, n-paraffin wax and Methods have been proposed in which a nitrogen-containing compound is used in combination, but these methods do not work effectively on heavy light oil or heavy oil obtained from heavy crude oil containing large amounts of paraffin, such as Daqing and Minas. Regarding the low-temperature fluidity of fuel oil, the present inventors have
In our research into the relationship between the morphology of wax that precipitates from fuel oil at low temperatures and the effects of additives, we discovered the following interesting phenomenon. In other words, in order to improve the low-temperature fluidity of fuel oil, (1) the crystal size of wax that precipitates at low temperatures must be kept as small as possible; (2) To stably disperse the precipitated wax crystals in oil. These two points are important, and rather than the conventional method of combining these separate functions with a single compound, we need to create separate compounds with each function, namely (1) wax microcrystal. A more rational method is to combine two types of compounds: (2) a compound with the function of dispersing wax crystals stably in oil (microcrystallization agent) and (2) a compound with the function of stably dispersing wax crystals in oil. and found that it is effective. Based on these findings, the present inventors searched for compounds and combinations thereof that are effective as microcrystallization agents and dispersants, and arrived at the low-temperature fluidity improver of the present invention. That is, the gist of the present invention is that (A) the amount average degree of polymerization of the α-olefin having an average carbon number of 10 to 30 and maleic anhydride is 1 to 100;
and an aliphatic alcohol having an average carbon number of 6 to 28, the average number of carbon atoms of the longest chain alkyl group of the α-olefin and the average carbon atom of the longest carbon chain of the aliphatic alcohol. and (B) a reaction product of low molecular weight polyethylene with a weight average molecular weight of 300 to 20,000 and maleic anhydride. The present invention will be explained in detail below. Component A of the fluidity improver of the present invention is an adduct of an α-olefin having an average carbon number of 10 to 30 and maleic anhydride, and a higher alcohol.
As the reaction product of olefin and maleic anhydride, the other weight average degree of polymerization of the 1:1 adduct of α-olefin and maleic anhydride is 100 or less, preferably 45
Includes the following copolymers: Weight average degree of polymerization is 100
If it exceeds the above range, the solubility in fuel oil will be poor and the low-temperature fluidity effect will also be poor, which is not preferable. α used as a raw material for component A in the present invention
- Olefin is an olefinic hydrocarbon having a double bond at the α-position of a hydrocarbon having an average number of carbon atoms of 10 to 30, and even if this α-olefin is a single product, it is a mixture of α-olefins having different numbers of carbon atoms. It may be hot. The copolymerization reaction between α-olefin and maleic anhydride is carried out in the presence of a radical initiator using a suitable solvent such as benzene, toluene, xylene, methyl isobutyl ketone, dioxane, etc., or without solvent at 80°C. It is carried out at a temperature of ~180°C. Regarding the adduct of α-olefin and maleic anhydride corresponding to a degree of polymerization of 1, according to the conventional method,
α-olefin and maleic anhydride without solvent
It can be obtained by heating to 160-230°C. After the reaction is completed, the target compound is obtained by removing the solvent, unreacted α-olefin and maleic anhydride by distillation under reduced pressure. The constituent molar ratio of the reaction product α-olefin and maleic anhydride obtained in the reaction of α-olefin and maleic anhydride is usually in the range of 1:1 to 1:2, and any of these can be used. The reaction product of alpha-olefin and maleic anhydride is then reacted with an aliphatic alcohol having one hydroxyl group. This alcohol has an average number of carbon atoms of 6 to
28, preferably 7 to 21 linear or branched chains can be used. These alcohols may be used alone or as a mixture of alcohols having different numbers of carbon atoms, but in the present invention, the average number of carbon atoms in the longest carbon chain of the alcohol and the longest chain alkyl group (polymerized The sum of the average number of carbon atoms in the portions (which later become side chains) needs to be in the range of 21 to 40, preferably 24 to 34. When the total number of carbon atoms is less than 21 or more than 40, almost no effect can be expected. The reaction between the reaction product of α-olefin and maleic anhydride and the alcohol can be carried out according to a conventional method, optionally using an acid catalyst, in a suitable solvent such as benzene, toluene, xylene, methyl ethyl ketone, dioxane, etc. 60-140℃ without solvent
This is done by heating to. The reaction molar ratio of alcohol is suitably 1 to 2 times the molar ratio of the acid anhydride group in the reaction product of α-olefin and maleic anhydride. In the reaction product,
Average alcohol content is 0.5 per mole of acid anhydride group.
It is preferable to add up to 1.5 mol. After the reaction is completed, the acid catalyst is removed by washing with water, and the solvent and unreacted alcohol are removed by distillation.
The desired alcohol adduct (hereinafter simply referred to as adduct) is obtained. Salts of the above adducts can be obtained by conventional methods. For example, in a solvent such as benzene, toluene, xylene, etc.
Alternatively, the salt of the above adduct can be obtained by heating to 50 to 140°C with a hydroxide such as potassium hydroxide, sodium hydroxide, or ammonium hydroxide without a solvent and removing the generated water to the outside of the reaction system. . The adduct and its salt thus obtained are used with the wax microcrystallization agent described below,
Functions as a dispersant for microcrystalline wax. As the wax microcrystallization agent (component B), a reaction product of low molecular weight polyethylene with maleic anhydride having a weight average molecular weight of 300 to 20,000 is used. As the low molecular weight polyethylene, α-olefin or polyethylene wax obtained by low polymerization of ethylene, or grease wax produced as a by-product during the production of high molecular weight polyethylene, etc. are used.
If the weight average molecular weight of low molecular weight polyethylene is less than 300, the effect of microcrystallization will be poor due to insufficient interaction with the wax contained in fuel oil, and if the weight average molecular weight exceeds 20,000, the fuel It is not preferred because of its poor solubility in oil. The reaction product of low molecular weight polyethylene and maleic anhydride is prepared by mixing low molecular weight polyethylene with 0.1 to 40 wt% of maleic anhydride based on the conventional method, and then mixing the low molecular weight polyethylene with 0.1 to 40 wt% maleic anhydride in the presence or absence of a radical initiator. It can be obtained by heating in the presence of the compound to carry out a copolymerization reaction or a grafting reaction. The appropriate ratio of component B to component A is 0.1 to 10 times by weight, preferably 0.5 to 2 times by weight. The low-temperature fluidity improver composed of component A and component B obtained in this way can significantly improve fluidity at low temperatures by adding 10 to 10,000 ppm, preferably 100 to 1,000 ppm to hydrocarbon fuel oil. be able to. As described in detail above, in the present invention, by using together two components that do not exhibit a low-temperature fluidity effect on their own, it is possible to impart an excellent low-temperature fluidity effect to fuel oil. The present invention will be explained below with reference to Examples. The method for measuring the amount-average degree of polymerization and the method for testing low-temperature fluidity are shown below. (1) Measurement method of weight average degree of polymerization (Pw) Gel permeation chromatography (GP
Calculated by method C) using the standard polystyrene calibration curve and the following formula. Pw=ΣNiPi ² /ΣNiPi Where, Pw: Weight average degree of polymerization Ni: Number of molecules of molecule i Pi: Degree of polymerization of molecule i For measurement, use a high performance liquid chromatograph HLC- manufactured by Toyo Soda Kogyo Co., Ltd. The test was conducted using 802UR under the following conditions. Solvent: THF Column: 4000, 3000, 2000 x 2 (Toso column) Temperature: 40°C Flow rate: 1.2ml/min (2) Low temperature fluidity test method Low temperature fluidity evaluation is based on JIS K 2269 "Petroleum product fluidity test" method” to measure the pour point, or
Alternatively, measure the CFPP cold filter plugging point using an automatic filter plugging point tester TAMEC-CEPP-AEI (manufacturer: Yoshida Scientific Instruments Co., Ltd.) that complies with IP 309/76 standards. I did this by doing this. That is, a glass test tube covered with a stainless steel cylinder was immersed in a bath kept at -34℃, 45ml of the sample was placed inside, cooled, and a 350 mesh (pore diameter 44μ) stainless steel mesh (filter) was inserted at the tip. Insert a glass pipette set into the sample into the sample, draw the sample into the pipette under reduced pressure of 200 mm of water, and measure the temperature of the oil until the time it takes for 20 ml of the sample to rise to the specified scale on the pipette for 60 seconds. Tsute
Expressed as CFPP value. This CFPP value (temperature)
The lower the temperature, the lower the temperature at which the filter becomes clogged.
That is, it shows good low-temperature fluidity. Example [A-] Production of a reaction product of α-olefin and maleic anhydride 1.0 mol of α-olefin listed in Table-1,
1.2 mol of maleic anhydride and 3.0 mol of xylene (6.0 mol of xylene was used in experiment No. 7,
In Experiment No. 8, 3.0 mol of toluene was used. )
After filling the flask with nitrogen gas, adjust the temperature to 100℃ and add tert-butyl peroctate (purity 75) while stirring.
%) 6.92g (0.02mol) was added and reacted for 6 hours. Next, the temperature was raised to distill off xylene, and unreacted α-olefin and maleic anhydride were removed under reduced pressure to obtain an α-olefin/maleic anhydride copolymer. (Experiment No. 1~
8) The weight average degree of polymerization of the obtained copolymer was determined by gel permeation chromatography, and the copolymerization molar ratio of α-olefin and maleic anhydride was determined by elemental analysis, and is shown in Table 1. Ta. 1.0 mol of α-olefin having 18 carbon atoms and 1.0 mol of maleic anhydride were placed in one flask, and after purging with nitrogen, the mixture was stirred.
The temperature was raised to 200°C, and the reaction was continued at the same temperature for 8 hours.
Then, while gradually increasing the degree of vacuum, unreacted α
- Olefin and maleic anhydride are distilled off to form an α-olefin and maleic anhydride adduct.
Obtained 270g. The addition molar ratio of α-olefin and maleic anhydride was determined by measuring the acid value. The results are shown in Table-1.

[Table] Compounds, and the others are α-olefins having a single number of carbon atoms.
[A-] Production of component A Reactant of α-olefin produced in [A-] and maleic anhydride (Experiment No. 8) 290.5
(amount containing 1.0 mol of acid anhydride group), 200.4 g of synthetic alcohol having 13 carbon atoms (Diadol 13 (trademark), manufactured by Mitsubishi Chemical Industries, Ltd.) and 122.3 g of xylene were placed in one flask, and under stirring. Raise the temperature to 100℃ and react at the same temperature for 4 hours,
486 g of a half-esterified product of a reaction product of α-olefin and maleic anhydride was obtained. The degree of esterification of the obtained adduct was 48% as determined by acid value measurement.
was asked. In addition, an adduct of the α-olefin/maleic anhydride copolymer obtained in Experiment No. 5 of [A-] and an alcohol having 15 carbon atoms (Diadol 15 (trademark), manufactured by Mitsubishi Chemical Industries, Ltd.) and Potassium hydroxide in an amount equivalent to the hydroxyl group contained in the adduct is heated to 135 to 140°C with stirring in a flask, the water produced is removed from the reaction system, and an appropriate amount of xylene is added to adjust the concentration. The potassium salt of the adduct was prepared. Adducts with alcohols and salts thereof shown in Table 2 were produced in a similar manner and used as component A of the low temperature fluidity improver of the present invention.
The manufactured component A is shown in Table 3.

【table】

【table】

[Table] [B-] Production of component B-1 α-olefin with an average number of carbon atoms of about 48 (manufactured by Mitsubishi Chemical Industries, Ltd., Dialene 30 (trademark)) 600
g and 90.0 g of maleic anhydride were placed in one flask, and after purging with nitrogen, 4.56 g of tertiary butyl peroxide was added under stirring at a temperature of 180° C., and the reaction was carried out for 4 hours. Next, unreacted maleic anhydride was distilled off while gradually increasing the degree of vacuum, to obtain 690 g of an α-olefin/maleic anhydride copolymer (B-1). The weight average degree of polymerization of the obtained copolymer was determined to be 12.5 by gel permeation chromatography. Similarly, α-olefin/maleic anhydride copolymers (B-2 and B-3) were produced by changing the amount of maleic anhydride charged or the type of α-olefin. The results are shown in Table-4. α-olefin/maleic anhydride adducts (B-4 and B-5) were produced in the same manner as above, except that the reaction was carried out at 220°C for 8 hours without adding di-tertiary butyl peroxide. did. The results are shown in Table-4.

[Table] [B-] Production of component B-2 1000 g of low molecular weight polyethylene with a number average molecular weight of 3500 (grease wax, a by-product during polyethylene production) and 30 g of maleic anhydride were mixed into 2
After charging the mixture into a flask and purging with nitrogen, 2.2 g of tertiary butyl peroxide was added while stirring at a temperature of 160° C., and the mixture was reacted for 4 hours. Then, unreacted maleic anhydride was distilled off while gradually increasing the degree of vacuum to obtain 1028.7 g of a low molecular weight polyethylene/maleic anhydride copolymer (B-6) having a weight average molecular weight of about 6400. Similarly, low molecular weight polyethylene/maleic anhydride copolymers (B-7, B-8 and B-9) were produced by changing the amount of maleic anhydride charged or the type of low molecular weight polyethylene. The results are shown in Table-5.

[Table] [C-] Low temperature fluidity test-1 Commercially available light gas oil (specific gravity 0.8356, sulfur content 0.60,
Pour point -7.5℃, flash point 72℃, kinematic viscosity
2.71cst/50℃) and via heavy (specific gravity
0.9012, sulfur content 2.4, pour point +22.5℃, flash point
144℃, kinematic viscosity 11.68cst/50℃) by weight
80:20 blended fuel oil with previously manufactured ingredients
500 ppm of A and/or 500 ppm of component B were added to evaluate low temperature fluidity. Table 6 of the results
Shown below.

【table】

[Table] [C-] Low-temperature fluidity test-2 Component A and component B prepared previously were added to Minas A heavy oil with a pour point of 5°C, and the pour point was measured. The results are shown in Table-7.

【table】

【table】

Claims (1)

[Scope of Claims] 1 (A) α-olefin having an average number of carbon atoms of 10 to 30 and maleic anhydride having a quantity average degree of polymerization of 1 to 30;
100 reactant and an aliphatic alcohol having an average number of carbon atoms of 6 to 28, the average number of carbon atoms in the longest chain alkyl group of the α-olefin and the average carbon number of the longest carbon chain of the aliphatic alcohol. A low-temperature fluidity improver comprising: an adduct or a salt thereof having a sum of atomic numbers of 21 to 40; and (B) a reaction product of low molecular weight polyethylene with a weight average molecular weight of 300 to 20,000 and maleic anhydride.