A polyisobutylene succinimide dispersant, its preparation method and application

Abstract

The application belongs to the technical field of lubricating oil additives, and particularly relates to a polyisobutylene succinimide dispersant as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing polyisobutylene maleic anhydride, base oil and aromatic hydrocarbon solvent, then adding aminobenzene boronic acid, and performing reaction by increasing temperature to reflux temperature, and obtaining the polyisobutylene succinimide dispersant after filtration. The polyisobutylene succinimide dispersant is prepared by using polyisobutylene maleic anhydride and aminobenzene boronic acid, the molecular structure of the polyisobutylene succinimide dispersant contains not only an aromatic ring but also an oxygen-containing benzene boronic acid group, the aromatic ring and the benzene boronic acid group both have a good adsorption effect on soot particles, and the ability of the polyisobutylene succinimide dispersant to disperse soot is improved. The performance test results show that the oil product prepared by using the polyisobutylene succinimide dispersant of the application not only improves the soot dispersion performance of the oil product, but also improves the high-temperature detergency of the oil product, and the preparation process is simple and easy to implement.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil additive technology, specifically relating to a polyisobutylene succinimide dispersant, its preparation method, and its application. Background Technology

[0002] As important lubricant additives, dispersants mainly include polyisobutylene succinimide, polyisobutylene succinate, ashless phosphate, and benzylamine. Among them, polyisobutylene succinimide is more widely used, primarily in engine lubricants, such as diesel / gasoline engine lubricants, medium-speed cylindrical piston engine lubricants, and two-stroke gasoline engine lubricants. Engine lubricants account for approximately 80% of the total dispersant usage. Besides engine oils, ATF, gear oils, and hydraulic oils also use dispersants. As the engine runs, the soot concentration gradually increases, and the kinematic viscosity of the oil increases rapidly, reducing the fluidity of the lubricant. Aggregated soot particles can also clog filters, accelerating engine wear. Polyisobutylene succinimide, with its soot-dispersing properties, has become a major additive for solving the problem of soot dispersion in oils.

[0003] The preparation methods of polyisobutylene succinimide mainly include hydrocarbonation and amination processes: (1) Hydrocarbonation process: polyisobutylene reacts with maleic anhydride to generate polyisobutylene maleic anhydride; (2) Amination process: polyisobutylene maleic anhydride reacts with polar polyethylene polyamines (usually diethylenetriamine, triethylenetetramine, tetraethylenepentamine, etc.) to obtain it.

[0004] Chinese invention patent publication number CN118878723A discloses a method for preparing an anti-wear soot dispersant, comprising: preparing polyisobutylene succinimide; reacting polyisobutylene succinimide, boric acid, and aromatic phosphoric acid under the action of an accelerator to obtain a phosphate-boronized ashless dispersant; wherein, aromatic phosphoric acid is a phosphoric acid compound containing aromatic groups, which is composed of phosphorus atoms directly connected to aromatic rings. This invention selects aromatic phosphoric acid in the preparation process of the phosphate-boronized ashless dispersant, simultaneously introducing phosphorus and aromatic groups into the molecule, resulting in a phosphate-boronized ashless dispersant with superior soot dispersing performance compared to traditional phosphate-boronized polyisobutylene succinimide. Its soot dispersibility is even better than that of the unphosphate-boronized polyisobutylene succinimide dispersant. Furthermore, this phosphate-boronized ashless dispersant exhibits good anti-wear, friction-reducing, and antioxidant properties.

[0005] Another Chinese invention patent publication, CN105985470A, discloses a method for preparing a boronized ashless dispersant, comprising the following steps: First, an amine compound is reacted with glycidol in a ring-opening reaction to prepare an intermediate amine; then, polyisobutylene maleic anhydride and base oil are reacted with the aforementioned intermediate amine to prepare polyisobutylene succinimide; finally, the polyisobutylene succinimide is reacted with a boron-containing compound and a solvent to prepare the boronized ashless dispersant. This preparation method improves the boron content, hydrolytic stability, and low-temperature sludge dispersion performance of the boronized ashless dispersant, and the product can be used in lubricating oils such as internal combustion engine oils, gear oils, and transmission fluids.

[0006] Another invention patent publication number, US8067347, reports the use of a mixture of various polyetheramines and their derivatives, such as polyetheramine alcohol, polyalkylene polyamine, and N-phenylphenyldiamine, to react with polyisobutylene maleic anhydride, etc., to prepare a polyisobutylene succinimide product with good soot dispersibility, which can be used to blend high-grade diesel engine oil.

[0007] Another frequently reported method involves grafting maleic anhydride onto high molecular weight compounds such as ethylene-propylene copolymers and poly-α-olefins, and then reacting them with polyethylene polyamines, 4-aminodiphenylamine, etc., to prepare high molecular weight products with good soot dispersibility.

[0008] However, the above-mentioned soot-dispersible polyisobutylene succinimide dispersants mainly suffer from problems such as complex synthesis process, large dosage, and poor high-temperature cleaning performance. Therefore, high-efficiency and multifunctional soot-dispersible additives have become an important research topic in high-grade diesel engine oil additives. Summary of the Invention

[0009] This invention addresses the problems existing in the prior art by providing a polyisobutylene succinimide dispersant, its preparation method, and its application.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A method for preparing a polyisobutylene succinimide dispersant includes the following steps: mixing polyisobutylene maleic anhydride, base oil and aromatic solvent, then adding aminophenylboronic acid, heating to reflux temperature for reaction, and filtering to obtain the dispersant.

[0012] Preferably, the number-average molecular weight of the polyisobutylene maleic anhydride is 500-5000.

[0013] More preferably, the number-average molecular weight of the polyisobutylene maleic anhydride is 900-2500.

[0014] Preferably, the kinematic viscosity of the base oil at 100°C is 2-20 mm. 2 / s.

[0015] More preferably, the kinematic viscosity of the base oil at 100°C is 4-8 mm. 2 / s.

[0016] Preferably, the aromatic solvent is selected from one or more of benzene, toluene, and xylene.

[0017] More preferably, the aromatic solvent is xylene.

[0018] Preferably, the mixing temperature is 50-70℃, the mixing time is 0.5-1.5h, and the mixing is carried out at 100-300rpm.

[0019] Preferably, the aminophenylboronic acid is selected from one or more of 2-aminophenylboronic acid, 3-aminophenylboronic acid, and 4-aminophenylboronic acid.

[0020] Preferably, the mass ratio of the polyisobutylene maleic anhydride, base oil, and aromatic solvent is 100:30-50:30-100.

[0021] Preferably, the molar ratio of polyisobutylene maleic anhydride to aminobenzoic acid is 1:0.8-0.9.

[0022] Preferably, the reflux temperature is 110-150℃, the reaction time is 4-12h, and the solvent is removed under reduced pressure after the reaction is completed.

[0023] More preferably, the reflux temperature is 130-150°C, and the reaction time is 6-10 hours.

[0024] The present invention also provides a polyisobutylene succinimide dispersant prepared by the above preparation method.

[0025] The present invention also provides the application of the above-mentioned polyisobutylene succinimide dispersant in the preparation of internal combustion engine lubricating oil additives.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) In this invention, polyisobutylene succinic anhydride is reacted with aminophenylboronic acid to prepare polyisobutylene succinimide. The molecular structure contains not only an aromatic ring, but also an oxygen-containing phenylboronic acid group. Both the aromatic ring and the phenylboronic acid group have a good adsorption effect on soot particles, which improves the ability of polyisobutylene succinimide to disperse soot.

[0028] (2) Performance test results show that the preparation of oil products using the polyisobutylene succinimide dispersant of the present invention not only improves the soot dispersion performance of the oil products, but also improves their high-temperature detergency, and the preparation process is simple and easy to implement. Detailed Implementation

[0029] It is worth noting that the raw materials used in this invention are all commercially available products. Specifically, the polyisobutylene maleic anhydride produced by the thermal addition process with a number average molecular weight of 1112 and 1403 was purchased from Wuxi Southern Petroleum Additives Co., Ltd.; the polyisobutylene maleic anhydride produced by the chlorination process with a number average molecular weight of 1185 and 1457 was purchased from Lanzhou PetroChina Lubricating Oil Additives Co., Ltd.; and T151, T152, T161 and T154B were all purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0030] Example 1

[0031] First, add 100 parts (0.090 mol) of polyisobutylene maleic anhydride produced by thermal addition with a number-average molecular weight of 1112 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2 The base oil and 50 parts of toluene were heated to 60°C and stirred at 200 rpm for 1 hour. Then, 9.8 parts (0.072 mol) of 2-aminophenylboronic acid were added, the temperature was raised to reflux temperature of 110°C, and the reaction was carried out for 10 hours. The solvent was removed under reduced pressure, and the product was filtered to obtain polyisobutylene succinimide dispersant with a boron content of 0.46% and a nitrogen content of 0.62%.

[0032] The structural formula of the dispersant is shown in formula (Ⅰ):

[0033]

[0034] In formula (Ⅰ), PIB is polyisobutylene.

[0035] Example 2

[0036] First, add 100 parts (0.090 mol) of polyisobutylene maleic anhydride produced by thermal addition with a number-average molecular weight of 1112 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2 The base oil and 50 parts xylene were heated to 60°C and stirred at 200 rpm for 1 hour. Then, 9.8 parts (0.072 mol) of 2-aminophenylboronic acid were added, the temperature was raised to reflux temperature of 140°C, and the reaction was carried out for 10 hours. The solvent was removed under reduced pressure, and the product was filtered to obtain polyisobutylene succinimide dispersant with a boron content of 0.49% and a nitrogen content of 0.65%.

[0037] Example 3

[0038] First, add 100 parts (0.090 mol) of polyisobutylene maleic anhydride produced by thermal addition with a number-average molecular weight of 1112 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2Mineral oil and 50 parts xylene were mixed and kept at 60°C, stirred at 200 rpm for 1 hour; then 9.8 parts (0.072 mol) of 3-aminophenylboronic acid were added, the temperature was raised to reflux temperature of 140°C, and the reaction was carried out for 6 hours. The solvent was removed under reduced pressure, and after filtration, polyisobutylene succinimide dispersant was obtained. The boron content of the dispersant was 0.48%, and the nitrogen content was 0.67%.

[0039] The structural formula of this dispersant is shown in formula (Ⅱ):

[0040]

[0041] In formula (II), PIB is polyisobutylene.

[0042] Example 4

[0043] First, add 100 parts (0.090 mol) of polyisobutylene maleic anhydride produced by thermal addition with a number-average molecular weight of 1112 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2 Mineral oil and 50 parts xylene were mixed and kept at 60°C, stirred at 200 rpm for 1 hour; then 9.8 parts (0.072 mol) of 4-aminophenylboronic acid were added, the temperature was raised to reflux temperature of 140°C, and the reaction was carried out for 6 hours. The solvent was removed under reduced pressure, and the mixture was filtered to obtain polyisobutylene succinimide dispersant with a boron content of 0.49% and a nitrogen content of 0.66%.

[0044] The structural formula of this dispersant is shown in formula (Ⅲ):

[0045]

[0046] In formula (Ⅲ), PIB is polyisobutylene.

[0047] Example 5

[0048] First, add 100 parts (0.071 mol) of polyisobutylene maleic anhydride produced by thermal addition with a number-average molecular weight of 1403 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2 The base oil and 50 parts xylene were heated to 60°C and stirred at 200 rpm for 1 hour. Then 7.7 parts (0.056 mol) of 3-aminophenylboronic acid were added, the temperature was raised to reflux temperature of 140°C, and the reaction was carried out for 6 hours. The solvent was removed under reduced pressure, and the product was filtered to obtain polyisobutylene succinimide dispersant with a boron content of 0.39% and a nitrogen content of 0.53%.

[0049] Example 6

[0050] First, add 100 parts (0.084 mol) of polyisobutylene maleic anhydride produced by the chlorination process with a number-average molecular weight of 1185 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2 The base oil and 50 parts xylene were heated to 60°C and stirred at 200 rpm for 1 hour. Then, 9.8 parts (0.072 mol) of 3-aminophenylboronic acid were added, the temperature was raised to reflux temperature of 140°C, and the reaction was carried out for 8 hours. The solvent was removed under reduced pressure, and the product was filtered to obtain polyisobutylene succinimide dispersant with a boron content of 0.49% and a nitrogen content of 0.65%.

[0051] Example 7

[0052] First, add 100 parts (0.069 mol) of polyisobutylene maleic anhydride produced by the chlorination process with a number-average molecular weight of 1457 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2 The base oil and 50 parts xylene were heated to 60°C and stirred at 200 rpm for 1 hour. Then 7.7 parts (0.056 mol) of 4-aminophenylboronic acid were added, the temperature was raised to reflux temperature of 140°C, and the reaction was carried out for 6 hours. The solvent was removed under reduced pressure, and the product was filtered to obtain polyisobutylene succinimide dispersant with a boron content of 0.38% and a nitrogen content of 0.52%.

[0053] Example 8

[0054] First, add 100 parts (0.069 mol) of polyisobutylene maleic anhydride produced by the chlorination process with a number-average molecular weight of 1457 and 50 parts of a kinematic viscosity of 6.171 mm at 100°C to the reaction flask. 2 Mineral oil and 30 parts xylene were mixed and kept at 50°C, stirred at 100 rpm for 1 hour; then 8.5 parts (0.062 mol) of 4-aminophenylboronic acid were added, the temperature was raised to reflux temperature of 145°C, and the reaction was carried out for 10 hours. The solvent was removed under reduced pressure, and the mixture was filtered to obtain polyisobutylene succinimide dispersant with a boron content of 0.40% and a nitrogen content of 0.54%.

[0055] Comparative Example 1

[0056] Same as Example 5, except that 3-aminophenylboronic acid is replaced with tetraethylenepentamine.

[0057] First, add 100 parts (0.071 mol) of polyisobutylene maleic anhydride produced by thermal addition with a number-average molecular weight of 1403 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2 / s base oil and 50 parts xylene were heated to 60℃ and stirred at 200 rpm for 1 h; then 10.6 parts (0.056 mol) tetraethylenepentamine were added, the temperature was raised to reflux temperature of 140℃, and the reaction was carried out for 6 h. The solvent was removed under reduced pressure, and after filtration, polyisobutylene succinimide dispersant was obtained with a nitrogen content of 2.39%.

[0058] The structural formula of this dispersant is shown in formula (Ⅳ):

[0059]

[0060] In formula (Ⅳ), PIB stands for polyisobutylene.

[0061] Comparative Example 2

[0062] Same as Example 5, except that 3-aminophenylboronic acid is replaced with 3-aminobenzoic acid.

[0063] First, add 100 parts (0.069 mol) of polyisobutylene maleic anhydride produced by the chlorination process with a number-average molecular weight of 1457 and 30 parts of a kinematic viscosity of 5.371 mmHg at 100°C to the reaction flask. 2 The base oil and 50 parts xylene were heated to 60°C and stirred at 200 rpm for 1 hour. Then 7.7 parts (0.056 mol) of 3-aminobenzoic acid were added, the temperature was raised to reflux temperature of 140°C, and the reaction was carried out for 6 hours. The solvent was removed under reduced pressure, and the product was filtered to obtain polyisobutylene succinimide dispersant with a nitrogen content of 0.52%.

[0064] The structural formula of this dispersant is shown in formula (V):

[0065]

[0066] In formula (V), PIB stands for polyisobutylene.

[0067] Comparative Example 3

[0068] 100 parts of the product of Comparative Example 1, 2.9 parts of boric acid and 30 parts of xylene were added to the reaction flask. The temperature was raised to reflux temperature of 140°C and reacted for 10 hours. The solvent was removed under reduced pressure and filtered to obtain polyisobutylene succinimide dispersant with a boron content of 0.40% and a nitrogen content of 2.27%.

[0069] The structural formula of this dispersant is shown in formula (VI):

[0070]

[0071] In formula (VI), PIB stands for polyisobutylene.

[0072] Test Example 1

[0073] The polyisobutylene succinimide dispersants prepared in Examples 1-8 and Comparative Examples 1-3 were blended with commercially available T151, T152, T161, and T154B at a dosage of 3% to form diesel engine oil, and their soot dispersion performance was tested.

[0074] The preparation method of diesel engine oil is as follows: by weight, 3.0 parts of polyisobutylene succinimide dispersant, 0.3 parts of polyalphaolefin pour point depressant, 5.0 parts of polyethylene propylene copolymer viscosity index improver, 2.5 parts of magnesium alkyl sulfonate metal detergent, 0.8 parts of sulfurized alkylphenol calcium metal detergent, 0.7 parts of thiophosphoric bisoctyl zinc salt antioxidant and corrosion inhibitor, 0.3 parts of alkyl dithiocarbamate, 1.0 part of amine antioxidant and 86.4 parts of Group III mineral base oil are mixed evenly to obtain the product.

[0075] The soot dispersibility of diesel fuel was evaluated using a diesel engine soot dispersibility tester. The evaluation method involved mixing a dispersant with diesel engine oil and placing it in a steel pipe, which served as the soot absorption tube. This pipe was then placed in a 100°C oil bath at a constant temperature. Soot produced after diesel combustion was drawn into the absorption tube. Over time, the soot content in the tube gradually increased, the viscosity of the oil increased, and the negative pressure in the tube slowly rose. The absorption time was recorded when the negative pressure reached -1200 Pa. A longer absorption time indicates a stronger soot-carrying capacity and better soot dispersibility.

[0076] The test results are shown in Table 1.

[0077] Table 1 Results of soot dispersibility test

[0078] serial number Absorption time Example 1 5 hours and 19 minutes Example 2 5 hours and 37 minutes Example 3 5 hours and 8 minutes Example 4 5 hours and 13 minutes Example 5 5 hours and 21 minutes Example 6 5 hours and 41 minutes Example 7 5 hours and 27 minutes Example 8 5 hours and 19 minutes Commercially available T151 3 hours and 37 minutes Commercially available T152 3 hours and 9 minutes Commercially available T161 3 hours and 52 minutes Commercially available T154B 3 hours and 18 minutes Comparative Example 1 3 hours and 27 minutes Comparative Example 2 3 hours and 32 minutes Comparative Example 3 4 hours 11 minutes

[0079] As can be seen from the data in Table 1, the absorption time of diesel engine oils blended with commercially available polyisobutylene succinimide T151, T152, T161 and T154B is less than 4 hours, while the absorption time of diesel engine oils blended in Examples 1-8 is more than 5 hours, indicating that the products in the examples have better soot dispersibility.

[0080] As can be seen from the comparison between Comparative Examples 1 and 2 and Example 5, after replacing aminophenylboronic acid with tetraethylenepentamine and aminobenzoic acid respectively, the absorption time of diesel engine oil was shorter than that of Example 5, and its soot dispersion performance was significantly different from that of the Example.

[0081] As can be seen from the comparison between Comparative Example 3 and Example 5, the boron-containing product after boronizing polyisobutylene succinic acid has a shorter diesel engine oil absorption time than that of Example 5, and its soot dispersion performance is also significantly different from that of the Example.

[0082] In addition, the soot dispersion performance of diesel engine oil formulated with 2.5% of the dispersant in Example 1 (the amount of base oil added was increased from 86.4% to 86.9%, while the amount of other additives remained unchanged) was evaluated. The absorption time was 4 hours and 38 minutes. It can be seen that the oil still has good soot dispersion after reducing the amount of dispersant added.

[0083] Test Example 2

[0084] The polyisobutylene succinimide dispersants prepared in Examples 1-8 and Comparative Examples 1-3 were blended with commercially available T151, T152, T161, and T154B at a dosage of 3% to form diesel engine oils, and their high-temperature detergency performance was tested. The preparation method of the diesel engine oil was the same as that in Test Example 1.

[0085] The high-temperature detergency performance was evaluated using an L-1 type plate coking tendency tester: the test oil was heated to 100°C and splashed onto a 300°C test aluminum plate by a high-speed rotating oil splasher. After running for 2 hours, the weight of coke generated on the aluminum plate by the test oil sample was weighed to evaluate the high-temperature detergency. The smaller the amount of coke, the better the high-temperature detergency.

[0086] The test results are shown in Table 2.

[0087] Table 2. High-Temperature Cleanliness Test Results

[0088]

[0089]

[0090] As can be seen from the data in Table 2, the coking content of the diesel engine oils blended from Examples 1-8 is all below 10 mg, exhibiting excellent high-temperature detergency. Among commercially available products, T154B boronized polyisobutylene succinimide has relatively good high-temperature detergency, but its coking content is higher than that of the examples, and its high-temperature detergency performance is inferior to that of the examples.

[0091] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a polyisobutylene succinimide dispersant, characterized in that, The process includes the following steps: mixing polyisobutylene maleic anhydride, base oil, and aromatic solvent, then adding aminophenylboronic acid, heating to reflux temperature for reaction, and filtering to obtain the final product.

2. The preparation method according to claim 1, characterized in that, The number-average molecular weight of the polyisobutylene maleic anhydride is 500-5000.

3. The preparation method according to claim 2, characterized in that, The number-average molecular weight of the polyisobutylene maleic anhydride is 900-2500.

4. The preparation method according to claim 1, characterized in that, The base oil has a kinematic viscosity of 2-20 mmHg at 100°C. 2 / s.

5. The preparation method according to claim 4, characterized in that, The base oil has a kinematic viscosity of 4-8 mm at 100°C. 2 / s.

6. The preparation method according to claim 1, characterized in that, The aromatic solvent is selected from one or more of benzene, toluene, and xylene.

7. The preparation method according to claim 1, characterized in that, The mixing temperature is 50-70℃, the mixing time is 0.5-1.5h, and the mixing needs to be stirred at 100-300rpm.

8. The preparation method according to claim 1, characterized in that, The aminophenylboronic acid is selected from one or more of 2-aminophenylboronic acid, 3-aminophenylboronic acid, and 4-aminophenylboronic acid.

9. The preparation method according to claim 1, characterized in that, The mass ratio of polyisobutylene maleic anhydride, base oil, and aromatic solvent is 100:30-100:20-150.

10. The preparation method according to claim 1, characterized in that, The molar ratio of polyisobutylene maleic anhydride to aminobenzoic acid is 1:0.7-1.

11. The preparation method according to claim 1, characterized in that, The reflux temperature is 80-150℃, the reaction time is 4-12h, and the solvent is removed under reduced pressure after the reaction is completed.

12. A polyisobutylene succinimide dispersant prepared by the preparation method according to any one of claims 1-11.

13. The use of a polyisobutylene succinimide dispersant prepared by any one of claims 1-11 or the polyisobutylene succinimide dispersant of claim 12 in the preparation of internal combustion engine lubricating oil additives.

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