A soot ashless dispersant and its preparation method and application

Abstract

The present disclosure relates to a soot ashless dispersant, its preparation method, and its application. The soot ashless dispersant disclosed herein comprises a polyamide compound having a structure represented by the following formula (1). The disclosed preparation method is simple and has high synthesis efficiency. The prepared soot ashless dispersant exhibits excellent dispersibility and can effectively solve soot dispersion problems. #imgabs0#

Description

Technical Field

[0001] The present disclosure relates to the field of lubricating oil additives, and in particular to a soot ashless dispersant and a preparation method and application thereof. Background Art

[0002] Ashless dispersant is one of the most important single-agent varieties in the formulation of internal combustion engine lubricating oil. Its function is to disperse the carbon deposits produced by incomplete combustion of fuel and the sludge generated by oxidation and aging of the lubricating oil, reduce engine wear and oil filter blockage, and ensure normal lubrication of the engine. Currently, the most widely used ashless dispersant is polyisobutylene succinimide.

[0003] To meet environmental regulations limiting nitrogen oxide emissions from diesel engines, engine manufacturers have generally adopted a series of new technologies, including piston top ring positioning, delayed injection, and periodic recirculation, to reduce nitrogen oxide emissions. While these technologies lower peak combustion chamber temperatures and reduce nitrogen oxide generation and emissions, they also exacerbate incomplete diesel combustion, leading to increased soot contaminants in heavy-duty diesel engine oils. This can cause excessive oil viscosity growth, engine component wear, oil filter clogging, and accelerated oil oxidation. Therefore, mitigating these negative impacts of soot contamination on engine performance is crucial.

[0004] The primary method for reducing soot pollution in existing technologies is to improve the soot-dispersing ability of lubricating oils. This is typically achieved by increasing the amount of dispersant used. However, excessive use of dispersant can affect properties such as the oil's low-temperature fluidity and the wear resistance of diesel engine components. Furthermore, domestically produced ashless dispersants have remained largely unchanged since the 1980s, and their molecular structure limits their ability to disperse graphitized soot.

[0005] In recent years, the research on soot ashless dispersants by several major additive manufacturers at home and abroad is mainly divided into aromatic amine, heteroatom ring type, and grafted ashless dispersants. Summary of the Invention

[0006] The purpose of the present disclosure is to provide a soot ashless dispersant and a preparation method and application thereof, wherein the soot ashless dispersant can effectively disperse soot and reduce the negative impact of soot pollution on engine performance.

[0007] A first aspect of the present disclosure provides a soot ashless dispersant, which comprises a polyamide compound having a structure represented by the following formula (1):

[0008]

[0009] wherein R1, R2, R3 and R4 are the same or different from each other and are independently selected from H, halogen, cyano and alkyl with 1 to 10 carbon atoms;

[0010] n1 represents the number of R1, n2 represents the number of R2, n3 represents the number of R3, and n4 represents the number of R4; n1, n2, n3 and n4 are the same or different and are independently selected from 1, 2, 3 or 4;

[0011] L is selected from a single bond or an alkylene group having 1 to 5 carbon atoms; PIB represents a polyisobutylene group.

[0012] Optionally, R1, R2, R3 and R4 are the same and are selected from H, halogen, cyano and alkyl with 1 to 10 carbon atoms; n1, n2 and n3 are the same and are selected from 1, 2, 3 or 4.

[0013] Alternatively, R1, R2, R3 and R4 are each H, and L is a single bond.

[0014] Optionally, the polyamide compound has a structure shown in the following formula (1-1):

[0015]

[0016] A second aspect of the present disclosure provides a method for preparing the soot ashless dispersant according to the first aspect of the present disclosure, the method comprising:

[0017] (A) contacting and reacting a first reactant and a second reactant in a first solvent to obtain an intermediate product;

[0018] (B) contacting and reacting the intermediate product with polyisobutylene maleic anhydride in a second solvent;

[0019] The first reactant has a structure as shown in the following formula (2), and the second reactant has a structure as shown in the following formula (3) or formula (4):

[0020]

[0021] Wherein, R5 is selected from an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, and the substituents of the substituted aryl group and the substituted cycloalkyl group are each independently selected from one or more of deuterium, halogen, and an alkyl group having 1 to 5 carbon atoms.

[0022] Optionally, the second reactant is selected from one of isatoic anhydride, 6-methylisatin and 6,8-dibromoisatin anhydride; or, the second reactant is selected from one of pentyl p-aminobenzoate, ethyl 2-aminobenzoate, menthol anthranilate and benzyl p-aminobenzoate; preferably, the second reactant is isatoic anhydride.

[0023] Optionally, in step (A), the molar ratio of the first reactant to the second reactant is 1:(3-3.5), preferably 1:(3-3.2); the reaction conditions include: reaction temperature of 80-100°C, reaction time of 8-12h; preferably, the reaction temperature is 85-95°C, and the reaction time is 9-10h.

[0024] Optionally, in step (B), the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3-3.5), preferably 1:(3-3.2); the reaction conditions include: reaction temperature of 140-160°C, reaction time of 4-8h; preferably, the reaction temperature is 145-155°C, and the reaction time is 5-7h.

[0025] Optionally, the number average molecular weight of the polyisobutylene maleic anhydride is 800 to 2500, preferably 1000 to 2300; in step (A), the first solvent is toluene, benzene or xylene, preferably toluene; in step (B), the second solvent is base oil, preferably 150SN or white oil, more preferably 150SN.

[0026] The third aspect of the present disclosure provides use of the soot ashless dispersant described in the first aspect of the present disclosure in lubricating oil for an internal combustion engine.

[0027] Through the above technical solution, the disclosed soot ashless dispersant comprises a polyamide compound with a centrosymmetrical structure, centered around a nitrogen atom and containing multiple positionally symmetrical amide functional groups and multiple benzene rings. The compound has a high overall symmetry and an appropriate molecular weight, which better matches the condensed-ring aromatic hydrocarbon structure of soot and provides improved dispersibility. The soot ashless dispersant not only effectively disperses soot but also controls the viscosity increase of the oil during use, effectively solving the soot dispersion problem. The disclosed preparation method is simple and has high synthesis efficiency.

[0028] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0030] Figure 1 is the infrared spectrum of the soot ashless dispersant prepared in Example 1 of the present disclosure;

[0031] Figure 2 This is the infrared spectrum of the intermediate product A1 prepared in Example 1 of the present disclosure. DETAILED DESCRIPTION

[0032] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0033] A first aspect of the present disclosure provides a soot ashless dispersant, which comprises a polyamide compound having a structure represented by the following formula (1):

[0034]

[0035] wherein R1, R2, R3 and R4 are the same or different from each other and are independently selected from H, halogen, cyano and alkyl with 1 to 10 carbon atoms;

[0036] n1 represents the number of R1, n2 represents the number of R2, n3 represents the number of R3, and n4 represents the number of R4; n1, n2, n3 and n4 are the same or different and are independently selected from 1, 2, 3 or 4;

[0037] L is selected from a single bond or an alkylene group having 1 to 5 carbon atoms; PIB represents a polyisobutylene group.

[0038] The soot ashless dispersant disclosed herein mainly comprises a polyamide compound represented by formula (1) above, for example, comprising 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, or 90% by weight or more. Preferably, the soot ashless dispersant is composed of a polyamide compound. The polyamide compound has multiple electron-donating amide groups and contains numerous large conjugated systems, has good structural symmetry, and is highly compatible with the structure of soot, thereby improving the soot dispersibility and extending the service life of the internal combustion engine lubricant.

[0039] In the present disclosure, when n1 is greater than 1, R1 is the same or different; when n2 is greater than 1, R2 is the same or different; when n3 is greater than 1, R3 is the same or different; when n4 is greater than 1, R4 is the same or different.

[0040] In the present disclosure, a single bond refers to a situation where no other atoms exist in the moiety represented by L. For example, when L in the chemical formula (1) is a single bond, N can be directly connected to the benzene ring.

[0041] In one embodiment of the present disclosure, R1, R2, R3, and R4 are the same and are selected from one of H, halogen, cyano, and an alkyl group having 1 to 10 carbon atoms; n1, n2, and n3 are the same and are selected from 1, 2, 3, or 4. Specifically, R1, R2, R3, and R4 can simultaneously be H, halogen, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, etc., but are not limited thereto. Further preferably, the substitution positions of R1, R2, R3 and R4 on their respective benzene rings may be the same, that is, the connection positions of R1, R2, R3 and R4 on their respective benzene rings have the same relative positional relationship to the amide group, for example, R1, R2, R3 and R4 are respectively ortho to the amide group on their respective benzene rings, or R1, R2, R3 and R4 are respectively meta to the amide group on their respective benzene rings.

[0042] In one embodiment of the present disclosure, R1, R2, R3 and R4 are each H, and L is a single bond.

[0043] In one embodiment of the present disclosure, the polyamide compound has a structure shown in the following formula (1-1):

[0044]

[0045] A second aspect of the present disclosure provides a method for preparing the soot ashless dispersant according to the first aspect of the present disclosure, the method comprising:

[0046] (A) contacting and reacting a first reactant and a second reactant in a first solvent to obtain an intermediate product;

[0047] (B) contacting and reacting the intermediate product with polyisobutylene maleic anhydride in a second solvent;

[0048] The first reactant has a structure as shown in the following formula (2), and the second reactant has a structure as shown in the following formula (3) or formula (4):

[0049]

[0050] Wherein, R5 is selected from an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 15 carbon atoms. Preferably, R5 is selected from an alkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 10 carbon atoms; further, the substituents of the substituted aryl group and the substituted cycloalkyl group are each independently selected from one or more of deuterium, halogen, and an alkyl group having 1 to 5 carbon atoms.

[0051] In one embodiment of the present disclosure, the second reactant is selected from one of isatoic anhydride, 6-methylisatin, and 6,8-dibromoisatin anhydride; or the second reactant is selected from one of pentyl p-aminobenzoate, ethyl 2-aminobenzoate, menthol anthranilate, and benzyl p-aminobenzoate; in a preferred embodiment, the second reactant is isatoic anhydride.

[0052] In one embodiment of the present disclosure, in step (A), the molar ratio of the first reactant to the second reactant is 1:(3-3.5), preferably 1:(3-3.2); the reaction conditions include: reaction temperature of 80-100°C, reaction time of 8-12h; preferably, the reaction temperature is 85-95°C, and the reaction time is 9-10h.

[0053] In one embodiment of the present disclosure, in step (B), the molar ratio of the intermediate product to polyisobutylene maleic anhydride is 1:(3-3.5); preferably 1:(3-3.2); the reaction conditions include: reaction temperature of 140-160°C, reaction time of 4-8h; preferably, reaction temperature of 145-155°C, reaction time of 5-7h.

[0054] In one embodiment of the present disclosure, the number average molecular weight of polyisobutylene maleic anhydride is 800 to 2500, preferably 1000 to 2300;

[0055] In step (A), the first solvent is toluene, benzene or xylene, preferably toluene; in step (B), the second solvent is base oil, preferably 150SN or white oil, more preferably 150SN.

[0056] In a preferred embodiment, the reactions in step (A) and step (B) are both carried out under the protection of an inert gas, wherein the inert gas is nitrogen, helium or argon, preferably nitrogen.

[0057] In the above embodiment, by adopting the preferred ratio and reaction conditions, a soot ashless dispersant containing a centrosymmetric polyamide compound can be further prepared. The soot ashless dispersant can effectively disperse soot and reduce the negative impact of soot pollution on engine performance.

[0058] The third aspect of the present disclosure provides use of the soot ashless dispersant described in the first aspect of the present disclosure in lubricating oil for an internal combustion engine.

[0059] The soot ashless dispersant obtained by the preparation method disclosed herein can be used to disperse soot in lubricating oil of internal combustion engines, effectively solving the soot dispersion problem.

[0060] Other features and advantages of the present disclosure will be described in detail in the following detailed description.

[0061] The present disclosure is further illustrated below by way of examples, but the present disclosure is not limited thereby.

[0062] In the following examples, unless otherwise specified, the raw materials used are commercially available products.

[0063] The intermediate product and the prepared soot ashless dispersant were tested by infrared spectrometer. The test method was as follows: the Fourier transform infrared spectrometer (FTIR) was AVATAR360 type from NICOLET Company of the United States. The solid sample was mixed with dry KBr and ground and then pressed into a pellet for testing. The transmission mode was selected and the scanning range was 4000-400 cm -1 .

[0064] Example 1

[0065] (A) To a 500 ml reactor, 2.9 g of tris(4-aminophenyl)amine and 4.89 g of isatoic anhydride were added, followed by 160 ml of toluene. The mixture was purged with nitrogen and refluxed with condensed water. The heating temperature was set to 90°C for 10 hours. The reaction was stopped and the toluene was evaporated to obtain intermediate product A1.

[0066] (B) 33 g of polyisobutylene maleic anhydride (number average molecular weight, 1000) was dissolved in 100 ml of 150SN and then added to the reactor containing the intermediate product A1. Nitrogen was introduced, condensation water was turned on, and the temperature was heated to 150° C. for 6 h. The reaction was then stopped to obtain the soot ashless dispersant F1 of this example.

[0067] The final product and intermediate product A1 were separated and purified and then subjected to infrared characterization. The infrared characterization results are as follows: Figure 1 and Figure 2 As shown, the structure of the final product is shown in the following formula (5), and the structure of the intermediate product A1 is shown in the following formula (6):

[0068]

[0069] Example 2

[0070] The method of Example 1 was adopted, except that the heating temperature in step (A) was set to 80°C for 12 hours, and the heating temperature in step (B) was set to 160°C for 5 hours, to obtain the soot ashless dispersant F2 of this example.

[0071] Example 3

[0072] The method of Example 1 was used, with the following differences: in step (A), the heating temperature was set to 100°C for 8 hours; in step (B), the heating temperature was set to 140°C for 8 hours, to obtain the soot ashless dispersant F3 of this example.

[0073] Comparative Example 1

[0074] The method of Example 1 was used, except that isatoic anhydride was omitted. Instead, tris(4-aminophenyl)amine and polyisobutylene maleic anhydride were reacted in a molar ratio of 1:3. The reaction conditions were as follows: 33 g of polyisobutylene maleic anhydride (number average molecular weight 1000) was dissolved in 100 ml of 150SN and added to a reactor. Then, 2.9 g of tris(4-aminophenyl)amine was added. Nitrogen was introduced, condensation water was activated, and the temperature was increased to 150° C. for 6 hours before the reaction was terminated. This yielded the soot ashless dispersant DF1 of this comparative example.

[0075] Comparative Example 2

[0076] The method of Example 1 was adopted, except that tris(4-aminophenyl)amine was replaced with an equimolar amount of diaminodiphenylmethane to obtain the soot ashless dispersant DF2 of this comparative example.

[0077] Comparative Example 3

[0078] The method of Example 1 was adopted, except that only polyisobutylene maleimide was used to synthesize the polyisobutylene maleimide-type ashless dispersant, wherein the number average molecular weight of the polyisobutylene maleimide was 1000. Thus, the soot ashless dispersant DF3 of this comparative example was obtained.

[0079] Test Case

[0080] The soot dispersibility of the dispersants of Examples 1-3 and Comparative Examples 1-3 was evaluated using an L-5 diesel engine oil soot dispersibility simulation tester. The test conditions were: 50g of 150SN as a base oil was added to a reactor, and then 4 weight percent of the above dispersants were added. The soot generated by the diesel combustion increased with increasing combustion time until the diesel flame was extinguished. The time interval from the start of combustion to the extinction of the diesel flame was recorded as the soot dispersibility time. The better the dispersant's dispersibility, the longer the soot dispersibility time. The experimental results are listed in Table 1 below.

[0081] Table 1

[0082]

[0083]

[0084] (Blank example: only 50g of 150SN base oil was added for reaction)

[0085] According to Table 1, a comparison of the data of Examples 1 to 3 with Comparative Examples 1 to 3 shows that the soot ashless dispersant disclosed herein exhibits better dispersibility and a longer smoke-through time when used in lubricating oils for internal combustion engines. A comparison of the data of Example 1 with Comparative Example 2 shows that the soot ashless dispersant disclosed herein uses a polyamine with good symmetry as a starting reactant, so the product has good symmetry, and the product structure has multiple amide groups and aromatic groups, so the soot ashless dispersant has better dispersibility. A comparison of the data of Example 1 with Comparative Examples 1 and 3 shows that the dispersant disclosed herein has good dispersibility due to the multiple amide groups and aromatic groups, and exhibits a longer smoke-through time when used in lubricating oils for internal combustion engines.

[0086] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0087] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0088] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A soot ashless dispersant, characterized in that: The soot ashless dispersant comprises a polyamide compound having a structure shown in the following formula (1): Formula (1) wherein R1, R2, R3 and R4 are the same or different from each other and are independently selected from H, halogen, cyano and alkyl with 1 to 10 carbon atoms; n1 represents the number of R1, n2 represents the number of R2, n3 represents the number of R3, and n4 represents the number of R4; n1, n2, n3 and n4 are the same or different and are independently selected from 1, 2, 3 or 4; L is selected from a single bond or an alkylene group having 1 to 5 carbon atoms; PIB represents a polyisobutylene group.

2. The soot ashless dispersant according to claim 1, characterized in that R1, R2, R3 and R4 are the same and are selected from one of H, halogen, cyano and alkyl with 1 to 10 carbon atoms; n1, n2 and n3 are the same and are selected from 1, 2, 3 or 4.

3. The soot ashless dispersant according to claim 1, characterized in that R1, R2, R3 and R4 are each H, and L is a single bond.

4. The soot ashless dispersant according to claim 1, characterized in that The polyamide compound has a structure shown in the following formula (1-1): Formula (1-1).

5. A method for preparing the soot ashless dispersant according to any one of claims 1 to 4, the method comprising: (A) contacting and reacting a first reactant and a second reactant in a first solvent to obtain an intermediate product; (B) contacting and reacting the intermediate product with polyisobutylene maleic anhydride in a second solvent; The first reactant has a structure as shown in the following formula (2), and the second reactant has a structure as shown in the following formula (3) or formula (4): Formula (2); Formula (3); Formula (4); wherein R5 is selected from an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, and the substituents of the substituted aryl group and the substituted cycloalkyl group are each independently selected from one or more of deuterium, halogen, and an alkyl group having 1 to 5 carbon atoms.

6. The method according to claim 5, characterized in that The second reactant is selected from one of isatoic anhydride, 6-methylisatin and 6,8-dibromoisatinic anhydride; or The second reactant is selected from one of pentyl p-aminobenzoate, ethyl 2-aminobenzoate, menthol anthranilate and benzyl p-aminobenzoate.

7. The method according to claim 6, characterized in that The second reactant is isatoic anhydride.

8. The method according to claim 5, characterized in that In step (A), the molar ratio of the first reactant to the second reactant is 1:(3-3.5); The reaction conditions include: reaction temperature of 80-100° C., and reaction time of 8-12 h.

9. The method according to claim 8, characterized in that In step (A), the molar ratio of the first reactant to the second reactant is 1:(3-3.2); The reaction conditions include: reaction temperature of 85-95° C., and reaction time of 9-10 h.

10. The method according to claim 5, characterized in that In step (B), the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3-3.5); The reaction conditions include: reaction temperature of 140-160° C., and reaction time of 4-8 h.

11. The method according to claim 10, characterized in that In step (B), the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3-3.2); The reaction conditions include: reaction temperature of 145-155° C., and reaction time of 5-7 h.

12. The method according to claim 5, characterized in that The number average molecular weight of the polyisobutylene maleic anhydride is 800-2500; In step (A), the first solvent is toluene, benzene or xylene; In step (B), the second solvent is a base oil.

13. The method according to claim 12, characterized in that The number average molecular weight of the polyisobutylene maleic anhydride is 1000-2300; In step (A), the first solvent is toluene; In step (B), the second solvent is 150SN or white oil.

14. The method according to claim 13, characterized in that In step (B), the second solvent is 150SN.

15. Use of the soot ashless dispersant according to any one of claims 1 to 4 in lubricating oil for internal combustion engines.

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