Ashless dispersant and preparation method thereof

Abstract

The present invention discloses an ashless dispersant and a preparation method thereof. The preparation method of the ashless dispersant comprises S1, selecting aminobenzoate ester compounds, polyisobutylene succinimide, and dibasic acid or polyacid compounds for standby use; S2, reacting the aminobenzoate ester compounds with dibasic acid or polyacid compounds in proportion to obtain an ester-terminated oligomer containing an aromatic amide structure; S3, reacting the polyisobutylene succinimide with the ester-terminated oligomer containing an aromatic amide structure under the action of a catalyst, and obtaining the ashless dispersant after dealcoholization. By adopting the method of the present invention, an ashless dispersant containing both aliphatic amine and aromatic amine in the same molecule is obtained. The ashless dispersant has both high efficiency in soot dispersing performance and excellent sludge dispersing performance. It does not need to be compounded with other dispersants, and can achieve excellent soot and sludge dual-effect dispersing effects with a relatively low dosage.

Description

Technical Field

[0001] The invention belongs to the field of dispersants, and in particular relates to an ashless dispersant and a preparation method thereof. Background Art

[0002] Incomplete combustion of diesel in the cylinder produces soot, which is mainly produced in the area close to the cylinder wall. This makes it easy for the soot to adhere to the cylinder wall and be washed off by the lubricating oil into the diesel engine's lubrication system. Lubricating oil oxidizes during use, producing liquid insolubles, which react with the incompletely burned fuel that enters the lubrication system, the water produced by combustion, the lubricating oil and its additives, etc. to form sludge or deposits on the surface of engine parts. In response to increasingly stringent environmental protection requirements, engine manufacturers have adopted a series of advanced technologies to reduce the emission of nitrogen oxides in diesel engine exhaust. The application of these technologies has aggravated the degree of incomplete combustion of diesel, resulting in an increase in the content of soot pollutants in heavy-duty diesel engine oil, which in turn causes problems such as excessive increase in oil viscosity, wear of engine parts, clogging of the oil filter, and accelerated oxidation of the oil. The main function of traditional polyisobutylene succinimide ashless dispersant is to inhibit the formation of low-temperature sludge and paint film, and its soot dispersion ability is poor. Simply increasing the dosage of this type of ashless dispersant can no longer solve the soot dispersion problem in heavy-duty diesel engine oil. At the same time, adding too much polyisobutylene succinimide will deteriorate the low-temperature starting performance of the oil, which is not conducive to the preparation of multi-grade oil.

[0003] Therefore, researchers have turned their attention to the development of dispersants with high soot dispersing performance. In recent years, major additive manufacturers at home and abroad have focused their research on soot ashless dispersants on aromatic and heteroatom ring types, especially aromatic amine ashless dispersants, which can not only effectively solve the soot dispersion problem, but also effectively control the viscosity growth of oil products during use.

[0004] The Lanzhou Lubricant Research and Development Center of PetroChina introduced aromatic amines into the molecular structure of polyisobutylene succinimide ashless dispersant (T161) and synthesized a new polyisobutylene succinimide-aromatic amine ashless dispersant (RHY165 ashless dispersant). The ashless dispersant passed the Mack T-8E engine bench test with a 5.5% dosage of CI-4 diesel engine oil. China National Petroleum Corporation's invention patent CN106867627 reported a method for preparing a soot dispersant, in which polyisobutylene succinic anhydride and polyene polyamine were reacted under the dilution of solvent and base oil, aromatic amines and aldehyde compounds were added to continue the reaction, and finally a molybdenum-containing reagent and water were added to react, and finally a dispersant with soot dispersibility and anti-smoke wear performance was obtained. China National Petroleum Corporation's invention patent CN105985827 reported a method for preparing a soot dispersant using acetic anhydride. Aromatic amine is dissolved in aromatic solvent, and then reacted with fatty amine, polyisobutylene succinic anhydride, and base oil. After the amination is completed, ethyl propionic anhydride (trimesic acid is used in this step in CN105985460) is added to continue the reaction, and finally the solvent is removed by reduced pressure distillation to obtain a dispersant with sludge dispersibility and soot dispersibility, which can be used for diesel engine oil of CH-4 and above. In the invention patent CN113150856 of Jinzhou Huifa Tianhe Chemical Co., Ltd., polyether amine and aromatic amine are used to react with a premix of polyisobutylene succinic anhydride and dimer acid to obtain a soot dispersant. This dispersant and conventional dispersants are compounded and used in the fully formulated oil at a dosage of 3.5% and 1.0% respectively, and the soot treatment ability is superior to that of conventional dispersants.

[0005] It can be seen that in the process of developing new soot dispersants, few researchers have considered whether the dispersants have excellent dispersing ability for sludge while having high efficiency in dispersing soot. If they only have high efficiency in dispersing soot but poor dispersing ability for sludge, they will inevitably need to be compounded with other dispersants in high-end engine oils, which is likely to increase the amount of dispersants used in the oil products, increase the cost of lubricating oil products, and weaken the competitiveness of the oil products.

[0006] Therefore, it is of great significance to provide a dispersant that has dispersibility for both soot and sludge. Summary of the invention

[0007] The main purpose of the present invention is to provide an ashless dispersant and a preparation method thereof, so as to overcome the deficiencies in the prior art.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0009] An embodiment of the present invention provides a method for preparing an ashless dispersant, comprising:

[0010] S1, selecting aminobenzoate compounds, polyisobutylene succinimide, and dibasic acid or polybasic acid compounds for standby use;

[0011] S2, reacting the aminobenzoate compound with a dibasic acid or a polybasic acid compound in proportion to obtain an ester-terminated oligomer containing an aromatic amide structure,

[0012] S3, reacting the polyisobutylene succinimide with an ester-terminated oligomer containing an aromatic amide structure under the action of a catalyst, and obtaining the ashless dispersant after dealcoholization.

[0013] Furthermore, the structural formula of the aminobenzoate ester compound is

[0014]

[0015] In the formula, x is a natural number; R1 is a straight-chain or branched alkyl group having 1 or more carbon atoms.

[0016] Further, the aminobenzoate compound includes any one or a combination of two or more of ethyl 4-aminobenzoate, methyl 3-aminophenylacetate, tert-butyl 2-aminobenzoate, tert-butyl 4-aminobenzoate, ethyl 3-aminobenzoate, methyl 3-aminobenzoate, methyl 4-aminobenzoate, ethyl 4-aminobenzoate, isopropyl 4-aminobenzoate, methyl 2-aminobenzoate, ethyl 2-aminobenzoate, isopropyl 2-aminobenzoate, butyl 2-aminobenzoate, and isobutyl 2-aminobenzoate.

[0017] Furthermore, the polyacid compound is a straight-chain or branched fatty polyacid containing two or more carboxyl groups in the molecule, or an aromatic polyacid in which the carboxyl group is directly connected to an aromatic ring.

[0018] Further, the polyacid compound includes any one or a combination of two or more of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, dodecanedioic acid, hexadecanedioic acid, octadecanedioic acid, docosanedioic acid, phthalic acid, dimer acid, trimer acid, and terephthalic acid.

[0019] Furthermore, the reaction molar ratio of the carboxyl group in the dibasic acid or polybasic acid compound to the amine group in the aminobenzoate compound is 1:1.0-1:1.5, the reaction temperature is 150-250° C., and the reaction time is 0.5-12 h.

[0020] Furthermore, the reaction molar ratio of the carboxyl group in the dibasic acid or polybasic acid compound to the amine group in the aminobenzoate compound is 1:1.0-1:1.3, the reaction temperature is 170-230° C., and the reaction time is 1-6 hours.

[0021] Furthermore, in step S3, the catalyst includes zinc acetate and / or solid acid.

[0022] Furthermore, in step S3, the reaction temperature of the polyisobutylene succinimide and the ester-terminated oligomer containing an aromatic amide structure is 60-120° C., and the reaction time is 1-10 h.

[0023] The embodiment of the present invention provides an ashless dispersant prepared by the above method, the structural formula of the ashless dispersant is

[0024]

[0025] In the formula, x is a natural number; n is a natural number greater than 0, and R2 is a linear or branched alkyl or aromatic group.

[0026] Compared with the prior art, the advantages of the present invention include: the present invention provides an ashless dispersant and a preparation method thereof. The preparation method of the ashless dispersant provided by the present invention comprises the following steps: pre-reacting an aminobenzoic acid ester compound with a dibasic acid or a polyacid compound to prepare an ester-terminated oligomer containing an aromatic amide structure, and then reacting the oligomer with a pre-synthesized polyisobutylene succinimide to obtain an ashless dispersant containing both aliphatic amine and aromatic amine in the same molecule. The ashless dispersant has both high-efficiency soot dispersibility and excellent sludge dispersibility, and does not need to be used in combination with other dispersants. An excellent soot and sludge dual-effect dispersing effect can be achieved with a relatively low dosage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of preparing an ashless dispersant provided in a typical embodiment of the present invention. DETAILED DESCRIPTION

[0028] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0029] like Figure 1 As shown, one aspect of an embodiment of the present invention provides a method for preparing an ashless dispersant, comprising:

[0030] S1, selecting aminobenzoate compounds, polyisobutylene succinimide, and dibasic acid or polybasic acid compounds for standby use;

[0031] In a specific implementation, the structural formula of the aminobenzoate ester compound is

[0032]

[0033] In the formula, x is a natural number; R1 is a straight or branched alkyl group having a carbon number greater than or equal to 1. Further, the aminobenzoate compound includes any one or a combination of two or more of ethyl 4-aminobenzoate, methyl 3-aminophenylacetate, tert-butyl 2-aminobenzoate, tert-butyl 4-aminobenzoate, ethyl 3-aminobenzoate, methyl 3-aminobenzoate, methyl 4-aminobenzoate, ethyl 4-aminobenzoate, isopropyl 4-aminobenzoate, methyl 2-aminobenzoate, ethyl 2-aminobenzoate, isopropyl 2-aminobenzoate, butyl 2-aminobenzoate, and isobutyl 2-aminobenzoate.

[0034] The polyacid compound is a straight-chain or branched fatty polyacid containing two or more carboxyl groups in the molecule, or an aromatic polyacid in which the carboxyl group is directly connected to an aromatic ring. The polyacid compound includes any one of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, dodecanedioic acid, hexadecanedioic acid, octadecanedioic acid, docosanedioic acid, phthalic acid, dimer acid, trimer acid, and terephthalic acid, or a combination of two or more thereof.

[0035] The polyisobutylene succinimide can be obtained by reacting polyisobutylene succinic anhydride with alkyl polyamines at a molar ratio of 1.1:1 to 1.8:1 at a certain temperature using a conventional process. The alkyl polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, polyethylenepolyamine, hexamethylenediamine, decanediamine, and 1,12-dodecanediamine, but are not limited thereto. Preferably, the molar ratio of the polyisobutylene succinic anhydride to the alkyl polyamines is 1.3:1 to 1.6:1.

[0036] S2, reacting the aminobenzoate compound with the dibasic acid or polyacid compound in proportion to obtain an ester-terminated oligomer containing an aromatic amide structure, in some embodiments, the reaction molar ratio of the carboxyl group in the dibasic acid or polyacid compound to the amine group in the aminobenzoate compound is 1:1.0-1:1.5, the reaction temperature is 150-250°C, and the reaction time is 0.5-12h. Preferably, the reaction molar ratio of the carboxyl group in the dibasic acid or polyacid compound to the amine group in the aminobenzoate compound is 1:1.0-1:1.3, the reaction temperature is 170-230°C, and the reaction time is 1-6h.

[0037] S3, reacting the polyisobutylene succinimide with the ester-terminated oligomer containing an aromatic amide structure under the action of a catalyst, and then dealcoholizing to obtain the ashless dispersant. The catalyst includes zinc acetate and / or a solid acid.

[0038] Preferably, in step S3, the reaction temperature of the polyisobutylene succinimide and the ester-terminated oligomer containing an aromatic amide structure is 60-120° C., and the reaction time is 1-10 h.

[0039] The present invention also provides an ashless dispersant prepared by the above method, the structural formula of the ashless dispersant is

[0040]

[0041] In the formula, x is a natural number; n is a natural number greater than 0, and R2 is a straight-chain or branched alkyl or aromatic group. From the above content, it can be seen that in the dispersant provided by the present invention, the polar chain is a relatively regular "fatty amine-aromatic amine-hydrocarbon group-aromatic amine-fatty amine" structure, and each dispersant molecule contains two fatty amines and two aromatic amines relatively evenly, so that a large amount of products containing both aromatic amines and fatty amines can be obtained.

[0042] The technical solution of the present invention is further described below with reference to several typical embodiments and drawings.

[0043] like Figure 1 As shown, this embodiment provides a method for preparing an ashless dispersant, comprising:

[0044] S1, selecting aminobenzoate compounds, polyisobutylene succinimide, and dibasic acid or polybasic acid compounds for standby use;

[0045] S2, reacting the aminobenzoate compound with a dibasic acid or a polybasic acid compound in proportion to obtain an ester-terminated oligomer containing an aromatic amide structure,

[0046] S3, reacting the polyisobutylene succinimide with an ester-terminated oligomer containing an aromatic amide structure under the action of a catalyst, and obtaining the ashless dispersant after dealcoholization.

[0047] The preparation method is to prepare an ester-terminated oligomer containing an aromatic amide structure by pre-reacting an aminobenzoic acid ester compound with a dibasic acid or a polybasic acid compound, and then reacting the oligomer with a pre-synthesized polyisobutylene succinimide to obtain an ashless dispersant containing both aliphatic amine and aromatic amine in the same molecule. The ashless dispersant has both high-efficiency soot dispersibility and excellent sludge dispersibility, and does not need to be used in combination with other dispersants. An excellent soot and sludge dual-effect dispersing effect can be achieved with a relatively low dosage.

[0048] Embodiment 1:

[0049] 2300 g (1.0 mol) of highly active polyisobutylene (number average molecular weight 2300, alpha olefin content ≥ 85 wt%) was added to a 5000 mL stainless steel autoclave, nitrogen was passed through, stirred and heated to 200°C; 176.5 g (1.8 mol) of molten maleic anhydride was slowly added dropwise over 30 min through a dropping device. After the addition was completed, the temperature in the reactor was slowly raised to 230°C, and the reaction was continued at this temperature for 4 hours. After the reaction was completed, nitrogen was blown into the reactor to blow the unreacted maleic anhydride out of the reactor. After testing, the saponification value of the reaction product was 60 mgKOH / g.

[0050] Embodiment 2:

[0051] In a 500mL four-necked bottle, add 150g of the reaction product in Example 1 and 130.4g of 150N hydrogenated base oil, slowly heat to 70-80°C and stir evenly, then slowly drop 10.8g of tetraethylenepentamine. After the dropwise addition, slowly heat the material to 150-170°C, pass nitrogen to purge the reaction for 4h, blow off the water generated by the reaction, and obtain a reaction product. After testing, the nitrogen content of the reaction product is 1.32wt%.

[0052] Embodiment 3:

[0053] In a 500mL four-necked bottle, add 150g of the reaction product in Example 1 and 124.6g of 150N hydrogenated base oil, slowly heat to 70-80°C and stir evenly, then slowly drop 13.8g of heavy polyethylene polyamine (average molecular weight 275, nitrogen content 33.5wt%, average 2.3 primary amines per molecule). After the dropwise addition, slowly heat the material to 150-170°C, pass nitrogen to purge the reaction for 4h, blow off the water generated by the reaction, and obtain a reaction product. After testing, the nitrogen content of the reaction product is 1.59wt%.

[0054] Embodiment 4:

[0055] Add 53.8 g of ethyl p-aminophenylacetate to a 250 mL four-necked flask, stir and heat to 90 °C to melt it completely, then slowly add 21.9 g of adipic acid, continue to heat after the addition, and when the temperature reaches 150 °C, introduce nitrogen into the system, heat to 230 °C and keep the temperature for 1 hour to obtain the reaction product.

[0056] Embodiment 5:

[0057] Add 53.8 g of ethyl p-aminophenylacetate to a 250 mL four-necked flask, stir and heat to 90°C to melt it completely, then slowly add 46.7 g of sebacic acid, continue to heat after the addition, and when the temperature reaches 150°C, introduce nitrogen into the system, heat to 200°C and keep the temperature for 3 hours to obtain the reaction product.

[0058] Embodiment 6:

[0059] 200 g of the reaction product of Example 2, 3.26 g of the reaction product of Example 4, and 4 g of anhydrous zinc acetate catalyst were added to a 500 mL four-necked bottle, and the temperature was raised to 90° C. under stirring, and the reaction was carried out under vacuum for 8 h to remove the alcohol generated by the reaction. After the reaction was completed, 10 g of 1000 mesh diatomaceous earth filter aid was added to filter to obtain a reaction product. After testing, the nitrogen content of the reaction product was 1.39 wt%.

[0060] Embodiment 7:

[0061] 200 g of the reaction product of Example 3, 5.38 g of the reaction product of Example 5, and 4 g of anhydrous zinc acetate catalyst were added to a 500 mL four-necked bottle, and the temperature was raised to 110° C. under stirring, and the reaction was carried out under vacuum for 5 h. The alcohol generated by the reaction was removed, and 10 g of 1000 mesh diatomaceous earth filter aid was added for filtration to obtain a reaction product. After testing, the nitrogen content of the reaction product was 1.68 wt%.

[0062] Comparative Example 1:

[0063] In a 500mL four-necked bottle, add 150g of the reaction product in Example 1 and 108.8g of 150N hydrogenated base oil, slowly heat to 70-80°C and stir evenly, then slowly drop 14.7g of heavy polyethylene polyamine (average molecular weight 275, nitrogen content 33.5wt%, average 2.3 primary amines per molecule). After the dropwise addition, slowly heat the material to 150-170°C, pass nitrogen to purge the reaction for 4h, blow off the water produced by the reaction, and obtain the reaction product. After testing, the nitrogen content of the reaction product is 1.80wt%.

[0064] The results show that:

[0065] The final products obtained in Example 2, Example 3, Example 6, Example 7 and Comparative Example 1 were added to the engine bench test used oil at a dosage of 0.5wt% and 1.0wt%, respectively. The soot content in the oil was 6.5wt% according to TGA analysis, and the kinematic viscosity at 100℃ was 59.24mm 2 / s. After stirring the old oil with added dispersant at 100℃ for 2 hours, the kinematic viscosity at 100℃ was tested and the viscosity reduction rate was calculated. The lower the kinematic viscosity and the greater the reduction rate, the stronger the ability of the added dispersant to prevent the oil from thickening and the stronger the ability to disperse soot.

[0066]

[0067] According to the above dispersibility evaluation data, the new high-efficiency ashless dispersant prepared in the examples of this patent (Example 6, Example 7) is better than the traditional high molecular weight polyisobutylene succinimide ashless dispersant (Example 2, Example 3, Comparative Example 1) in inhibiting the thickening of used oil at the same dosage, and when its dosage is half of the traditional polyisobutylene succinimide, its inhibitory effect on the thickening of used oil is equivalent to that of the traditional succinimide dispersant.

[0068] The final products obtained from Example 2, Example 3, Example 6, Example 7 and Comparative Example 1 were evaluated for their sludge dispersibility according to the industry standard (SH / T0623 Appendix A Ashless Dispersant Low Temperature Dispersibility Evaluation Method). The sludge dispersibility is represented by the sludge spot dispersion value SDT. The larger the SDT value, the better the sludge dispersibility. The industry standard stipulates that the ashless dispersant sample accounts for 5wt%. In order to more fully evaluate the sludge dispersibility, the sludge dispersibility when the ashless dispersant sample accounts for 2wt% was also compared, as shown in the following table.

[0069]

[0070] According to the above-mentioned low-temperature sludge dispersibility evaluation data, compared with the traditional polyisobutylene succinimide ashless dispersant (Example 2, Example 3, Comparative Example 1), the new high-efficiency ashless dispersant prepared in the examples of this patent (Example 6, Example 7) has better sludge dispersion performance, and can achieve the same sludge dispersion effect as the traditional polyisobutylene succinimide with less dosage.

[0071] In the present invention, aminobenzoic acid esters are connected into oligomers through dibasic acid or polybasic acid, and then reacted with monopolyisobutylene succinimide, so that aromatic amines and fatty amines are connected in the same dispersant molecule, and each dispersant molecule contains two fatty amines and two aromatic amines relatively evenly, which can contain more aromatic amines while having more fatty amines. This makes the dispersant obtained in the patent of the present invention have high efficiency in dispersing soot and sludge.

[0072] The above are only some embodiments of the present invention. It should be pointed out that for ordinary technicians in this field, other modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for preparing an ashless dispersant, characterized in that: include: S1, select aminobenzoate compounds, polyisobutylene succinimide and polyacid compounds for standby use; S2, reacting the aminobenzoate compound with the polyacid compound in proportion to obtain an ester-terminated oligomer containing an aromatic amide structure, S3, reacting the polyisobutylene succinimide with an ester-terminated oligomer containing an aromatic amide structure under the action of a catalyst, and obtaining the ashless dispersant after dealcoholization; The aminobenzoate compounds include any one or a combination of two or more of ethyl 4-aminobenzoate, methyl 3-aminobenzoate, tert-butyl 2-aminobenzoate, tert-butyl 4-aminobenzoate, ethyl 3-aminobenzoate, methyl 3-aminobenzoate, methyl 4-aminobenzoate, ethyl 4-aminobenzoate, isopropyl 4-aminobenzoate, methyl 2-aminobenzoate, ethyl 2-aminobenzoate, isopropyl 2-aminobenzoate, butyl 2-aminobenzoate, and isobutyl 2-aminobenzoate; The polyacid compound is a straight-chain or branched fatty polyacid containing two or more carboxyl groups in the molecule, or an aromatic polyacid in which the carboxyl group is directly connected to an aromatic ring; The polyacid compound includes any one or a combination of two or more of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, dodecanedioic acid, hexadecanedioic acid, octadecanedioic acid, docosanediic acid, phthalic acid, dimer acid, trimer acid, and terephthalic acid; The structural formula of polyisobutylene succinimide is: In the formula, n is a natural number greater than 0.

2. The method for preparing the ashless dispersant according to claim 1, characterized in that: The reaction molar ratio of the carboxyl group in the polyacid compound to the amine group in the aminobenzoate compound is 1:1.0-1:1.5, the reaction temperature is 150-250° C., and the reaction time is 0.5-12 hours.

3. The method for preparing the ashless dispersant according to claim 2, characterized in that: The reaction molar ratio of the carboxyl group in the polyacid compound to the amine group in the aminobenzoate compound is 1:1.0-1:1.3, the reaction temperature is 170-230° C., and the reaction time is 1-6 hours.

4. The method for preparing the ashless dispersant according to claim 1, characterized in that: In step S3, the catalyst includes zinc acetate and / or solid acid.

5. The method for preparing the ashless dispersant according to claim 1, characterized in that: In step S3, the reaction temperature of the polyisobutylene succinimide and the ester-terminated oligomer containing an aromatic amide structure is 60-120° C., and the reaction time is 1-10 hours.

6. An ashless dispersant prepared by the method according to any one of claims 1 to 5.

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