Preparation method of soot ash-free dispersant

Abstract

The present application relates to a kind of preparation methods of soot ashless dispersant, which comprises the following steps: S1: fatty amine is reacted with polyisobutylene maleic anhydride, and intermediate product is obtained;And S2: the intermediate product is reacted with aldehyde compound, aromatic amine;Wherein, the reaction temperature of step S1 is 90-170 DEG C, and the reaction temperature of step S2 is 95-130 DEG C.A kind of soot ashless dispersant of an embodiment of the present application has excellent soot dispersing performance, and can solve the problem of insufficient soot dispersing performance of existing ashless dispersant.

Description

Technical Field

[0001] This invention relates to dispersants, and more particularly to an ashless soot dispersant suitable for internal combustion engine oils. Background Technology

[0002] Environmental regulations are increasingly stringent on nitrogen oxide emissions from diesel engines. While the use of new technologies such as EGR (Exhaust Gas Recirculation) has reduced nitrogen oxide emissions, it has also exacerbated incomplete combustion of diesel fuel, leading to increased soot content in heavy-duty diesel engine oils. Soot combines with polar oxidation products in the lubrication system, increasing lubricant viscosity and adsorbing acidic substances, causing corrosion and wear. Soot accumulates and adheres to surfaces prone to friction and corrosion, causing wear on engine components. It also leads to problems such as clogged oil filters and accelerated oil oxidation.

[0003] The most important way to reduce soot pollution is to improve the soot dispersion ability of oil. The usual method is to increase the amount of dispersant. However, increasing the amount of dispersant will affect the low-temperature fluidity of the oil and the wear resistance of diesel engine parts. Therefore, there is an urgent need for dispersants with excellent soot dispersion properties that can ensure the soot dispersion of oil even at low addition levels. Summary of the Invention

[0004] To overcome at least one of the defects of the prior art, in a first aspect, one embodiment of the present invention provides a method for preparing an ashless soot dispersant, comprising the following steps:

[0005] S1: The fatty amine is reacted with polyisobutylene maleic anhydride to obtain an intermediate product; and

[0006] S2: React the intermediate product with aldehydes and aromatic amines;

[0007] The reaction temperature in step S1 is 90–170°C, and the reaction temperature in step S2 is 95–130°C.

[0008] Secondly, one embodiment of the present invention provides an internal combustion engine oil comprising the soot-free dispersant prepared by the above method.

[0009] The ashless soot dispersant prepared by the method of the present invention has excellent soot dispersion performance and can solve the problem of insufficient soot dispersion performance of existing ashless dispersants. Detailed Implementation

[0010] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the description herein is for illustrative purposes only and not intended to limit the present invention.

[0011] This invention provides a method for preparing an ashless soot dispersant, comprising the following steps:

[0012] S1: Aliphatic amines are reacted with polyisobutylene maleic anhydride (PIBSA) to obtain an intermediate product; and

[0013] S2: React the intermediate product with aldehydes and aromatic amines;

[0014] The reaction temperature in step S1 is 90–170°C, and the reaction temperature in step S2 is 95–130°C.

[0015] In one embodiment, the fatty amine includes one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and hexaethyleneheptamine, such as polyene polyamines.

[0016] One embodiment of the present invention discloses a method for preparing a soot-free dispersant by reacting a fatty amine with polyisobutylene maleic anhydride to obtain an intermediate product containing polyisobutylene succinimide, and then introducing aromatic amine groups into the polyisobutylene succinimide by reacting the intermediate product with formaldehyde and aromatic amines in a Mannich reaction, thereby obtaining an ash-free dispersant with soot dispersing properties.

[0017] In one embodiment, the reaction temperature of step S1 is 90-170°C, further 120-170°C, and even further 150-160°C, for example 100°C, 110°C, 120°C, 130°C, 135°C, 140°C, 145°C, 150°C, and 160°C.

[0018] In one embodiment, the reaction temperature in step S2 is 95–130°C, and more specifically 95–120°C, for example 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, or 130°C. Maintaining the reaction temperature within this range reduces the generation of impurities and byproducts.

[0019] In one embodiment, the reactions in steps S1 and S2 are carried out under the protection of an inert gas, such as nitrogen.

[0020] In one embodiment, the endpoint of the reaction can be determined in step S1 by the total acid value of the reaction, for example, by making the total acid value of the reaction system lower than 2 mg KOH / g. The acid value can reflect the conversion rate of polyisobutylene maleic anhydride. If the acid value is high, it indicates that some acidic groups are present, which will subsequently react with aromatic amines to generate byproducts.

[0021] In one embodiment of the present invention, base oil is used as the reaction medium in the reaction system. Since the base oil can be retained in the system for subsequent applications, the solvent removal step is omitted, simplifying the process. Furthermore, the absence of additional solvent can increase the content of the effective dispersant component in the obtained product, thereby improving dispersing performance.

[0022] In one embodiment, step S1 includes: mixing polyisobutylene maleic anhydride and base oil, and then adding a fatty amine to the mixture at a temperature of 95-135°C to react.

[0023] In one embodiment, the temperature at which the fatty amine is added in step S1 can be, for example, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, or 130°C.

[0024] In one implementation, the fatty amine can be added dropwise.

[0025] In one embodiment, the reaction time of step S1 can be 2 to 6 hours, for example, 2 hours, 3 hours, 4 hours or 5 hours; the reaction time of step S2 can be 5 to 10 hours, for example, 6 hours, 7 hours, 8 hours or 9 hours.

[0026] In one embodiment, the material system after the reaction in step S2 is completed is dehydrated, for example, at 140°C, to obtain a product containing a dispersant.

[0027] In one embodiment, during the reaction process in step S2, the temperature variation does not exceed 10°C, and more specifically, does not exceed 5°C.

[0028] In one embodiment, the lubricating base oil may be selected from one or more API Group I, II, III, IV, and V lubricating base oils, such as one or more mineral lubricating oils and synthetic lubricating oils; the mineral lubricating oil generally has a viscosity index greater than 80, a saturated hydrocarbon mass fraction greater than 90%, and a sulfur content mass fraction less than 0.03%. Solvent-refined mineral lubricating oils and hydrogenated base oils are preferred as lubricating base oils.

[0029] In one embodiment, the base oil may be a refined mineral lubricating oil, such as one or a mixture of two or more of 100N base oil, 100SN base oil, 150N base oil, 150SN base oil, 250N base oil, and 250SN base oil.

[0030] In one embodiment, the amount of base oil used is 20% to 50% of the total mass of the reaction system, for example, 25%, 30%, 35%, 40%, or 45%; wherein the reaction system includes aliphatic amines, polyisobutylene maleic anhydride, base oil, aldehyde compounds, and aromatic amines, and the total mass of the reaction system refers to the sum of the masses of the aforementioned materials.

[0031] In one embodiment, the number average molecular weight of polyisobutylene maleic anhydride is 500 to 5000, further 900 to 2500, and even further 1000 to 2300, for example 1000, 1300, 2300.

[0032] In one embodiment, the fatty amine is preferably one or more of tetraethylenepentamine, pentaethylenehexamine, and polyene polyamine.

[0033] In one embodiment, the aromatic amine may be one or more of aniline, naphthylamine, and their derivatives.

[0034] In one embodiment, the aromatic amine includes one or more of aniline, diphenylamine, 4-aminodiphenylamine, naphthylamine, N-phenyl-2-naphthylamine, N-phenyl-1-naphthylamine, N-phenyl-2-anthramine, N,N'-di(β-naphthyl)-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N-phenyl-N'-cyclohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine, N-sec-octyl-N'-phenyl-p-phenylenediamine, N-cyclohexyl-p-methoxyaniline, 4,4'-di(α-methylbenzyl)diphenylamine, and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine.

[0035] In one embodiment, the aromatic amine is 4-aminodiphenylamine (4-ADPA), whose structure is shown below:

[0036]

[0037] In one embodiment, the aldehyde compound includes one or more of aliphatic aldehydes and paraformaldehydes containing 1 to 10 carbon atoms. For example, one or more of benzaldehyde, phenylacetaldehyde, and formaldehyde; furthermore, the aldehyde compound can be added to the above reaction system in the form of an aqueous solution, such as an aqueous formaldehyde solution.

[0038] In one embodiment, the aliphatic aldehyde has the structural formula R-CHO, where R represents hydrogen or an alkyl group containing 1 to 9 carbon atoms. Further, R is a straight-chain alkyl group or an alkyl group with a straight chain. The aliphatic aldehyde comprises 1 to 10 carbon atoms, for example, 2, 3, 4, 5, 6, 7, 8, or 9. For example, the aliphatic aldehyde includes one or more of formaldehyde, acetaldehyde, butyraldehyde, pentanal, heptanal, octanal, nonanal, and decanal; further, the aliphatic aldehyde includes one or more of formaldehyde, acetaldehyde, n-butyraldehyde, n-pentanal, n-heptal, n-octanal, n-nonanal, and n-decanal.

[0039] In one embodiment, the molar ratio of the fatty amine to the polyisobutylene maleic anhydride is 1:1 to 1:2, for example, 1:1.2, 1:1.5, or 1:1.8.

[0040] In one embodiment, the molar ratio of aliphatic amine to aldehyde compound is 1:2 to 2:1, for example, 1:1 or 1.5:1.

[0041] In one embodiment, the molar ratio of aliphatic amine to aromatic amine is 1:1 to 3:1, for example, 1.5:1, 2:1, or 2.5:1.

[0042] One embodiment of the present invention provides an internal combustion engine oil comprising the soot-free dispersant prepared by the above method.

[0043] In one embodiment, the internal combustion engine oil is diesel engine oil.

[0044] The soot-free dispersant prepared by one embodiment of the present invention improves soot dispersibility by introducing aromatic amine groups into polyisobutylene succinimide.

[0045] The soot-free dispersant prepared by one embodiment of the present invention exhibits better soot dispersibility in CK-4 grade lubricating oil compared to commercially available CK-4 grade diesel engine oil compound.

[0046] The following describes, in conjunction with embodiments, a soot-free dispersant of the present invention and its preparation method. Unless otherwise specified, all raw materials used are commercially available.

[0047] Example 1

[0048] S1: Add 600g of polyisobutylene maleic anhydride (total acid value 106.8mgKOH / g) with a number average molecular weight of 1000 and 300g of refined mineral oil (150SN) to a 2L glass flask equipped with a mechanical stirrer, thermometer, heating mantle and nitrogen pipeline; then introduce nitrogen into the flask and turn on the mechanical stirrer; when the temperature inside the flask rises to 135℃, add 90.9g of tetraethylenepentamine dropwise, and after the addition is complete, react at 140℃ for 2 hours; then raise the temperature inside the flask to 170℃ and purge with nitrogen to dehydrate until the total acid value of the reaction solution is below 2mgKOH / g.

[0049] S2: Lower the temperature of the reaction solution in the flask to 120°C, add 70.7g of 4-aminodiphenylamine and 34.6g of paraformaldehyde (Nantong Jiangtian, HCHO%=96%) to the reaction solution; keep the reaction solution at 120°C for 5 hours, and then raise the temperature to 140°C to dehydrate and obtain the final product.

[0050] Example 2

[0051] This embodiment uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being:

[0052] In step S1, the polyisobutylene maleic anhydride used has a number average molecular weight of 1300 and a total acid value of 91.6 mg KOH / g; the amount of tetraethylenepentamine used is 77.9 g.

[0053] In step S2, the amount of 4-aminodiphenylamine used is 60.6g, and the amount of paraformaldehyde used is 29.6g.

[0054] Example 3

[0055] This embodiment uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being:

[0056] In step S1, the polyisobutylene maleic anhydride used has a number-average molecular weight of 2300 and a total acid value of 64.4 mg KOH / g; the amount of tetraethylenepentamine used is 59.3 g.

[0057] In step S2, the amount of 4-aminodiphenylamine used is 51.8g, and the amount of paraformaldehyde used is 25.4g.

[0058] Example 4

[0059] This embodiment uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being that the reaction temperature in step S2 is 95℃.

[0060] Example 5

[0061] This embodiment uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being that the reaction temperature in step S2 is 105℃.

[0062] Example 6

[0063] This embodiment uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being that the dropping temperature of tetraethylenepentamine in step S1 is 100°C.

[0064] Example 7

[0065] This embodiment uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being that N,N'-diphenyl-p-phenylenediamine is used instead of 4-aminodiphenylamine in step S2.

[0066] Example 8

[0067] This embodiment uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being that n-butyraldehyde is used instead of paraformaldehyde in step S2.

[0068] Example 9

[0069] This embodiment uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being that in step S2, polyethylene polyamine is used instead of tetraethylenepentamine.

[0070] Comparative Example 1

[0071] S1: Add 600g of polyisobutylene maleic anhydride (total acid value 106.8mgKOH / g) with a number average molecular weight of 1000 and 360.0g of refined mineral oil (150SN) to a 2L glass flask equipped with a mechanical stirrer, thermometer, heating mantle and nitrogen pipeline; then introduce nitrogen into the flask and turn on the mechanical stirrer to stir; when the temperature inside the flask rises to 40℃, add 46.8g of triethylenetetramine dropwise, and after the addition is complete, react at 110℃ for 4 hours.

[0072] S2: After the above reaction is completed, add 43.2g of 4-aminodiphenylamine and 51.6g of heptanal to the reaction solution; keep the reaction solution at 80℃ for 2 hours, then raise the temperature to 110℃ and react for 4 hours. After the reaction is completed, dehydrate to obtain the final product.

[0073] Comparative Example 2

[0074] This example uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant, the only difference being that in step S2, the reaction solution is kept at 140°C for 5 hours.

[0075] Comparative Example 3

[0076] This example uses the same raw materials and process as Example 1 to prepare the soot-free dispersant, the only difference being that the reaction temperature in step S2 is 80℃.

[0077] Comparative Example 4

[0078] This example uses the same raw materials and process as Example 1 to prepare the soot-free dispersant, the only difference being that 150g of toluene was added as a solvent to the reaction system.

[0079] Comparative Example 5

[0080] This example uses the same raw materials and process as Example 1 to prepare the soot-free dispersant, the only difference being that in step S1, the temperature at which tetraethylenepentamine is added is 40°C.

[0081] Comparative Example 6

[0082] This example uses the same raw materials and processes as Example 1 to prepare the soot-free dispersant. The only difference is that step S2 is different from that in Example 1. The process of step S2 is as follows:

[0083] S2: After the reaction in step S1 is completed, add 70.7g of 4-aminodiphenylamine and 34.6g of paraformaldehyde to the resulting reaction solution; keep the reaction solution at 80℃ for 2 hours, then raise the temperature to 110℃ and react for 4 hours. After the reaction is completed, dehydrate to obtain the final product.

[0084] Application examples

[0085] Carbon black was used instead of soot to test the soot dispersion performance of the dispersant in oil products, as detailed below:

[0086] The dispersants prepared in each example and comparative example, as well as the commercially available product OLOA5909, were formulated into CK-4 engine oils at a dosage of 2%. 8% carbon black was added to the engine oil to simulate high soot content conditions. The oil was homogenized for 30 minutes using a high-shear homogenizer (60-70℃, 10000-20000 r / min). The viscosity of the homogenized oil sample at 100℃ was determined using the countercurrent viscosity method according to GB / T11137-1989 standard. Lower viscosity indicates better soot dispersibility of the dispersant. The results are shown in Table 1.

[0087] Meanwhile, the product was detected by liquid chromatography (Agilent, 1260 Infinity, column: Eclipse XDB-C18, 5μm, 4.6×250mm). The impurity content was characterized by the peak area ratio at 254nm. The results are shown in Table 1.

[0088] Table 1

[0089]

[0090]

[0091] According to the results in Table 1, the engine oils prepared using the dispersants of Examples 1 to 9 of the present invention have lower viscosity than OLOA59094 and Comparative Examples 1 to 6, indicating that the dispersants of Examples 1 to 9 have better soot dispersion performance and solve the problem of insufficient dispersion of high soot in existing dispersants.

[0092] Compared to Example 1, Comparative Example 2 used a higher second reaction temperature. Table 1 shows that as the second reaction temperature increased, the impurity content in the dispersant significantly increased. This increased impurity content affects the content of the effective components in the dispersant and also impacts the compatibility of the dispersant with other additives. Comparative Examples 1, 3, and 6 used lower second reaction temperatures. Table 1 shows that as the second reaction temperature decreased, although the impurity content in the dispersant decreased, the viscosity of the oil sample significantly increased. Therefore, the preferred second reaction temperature is 95–120°C.

[0093] Compared to Example 1, Comparative Example 4 added toluene as a solvent. The results in Table 1 show that the viscosity of the oil sample increased after adding the additional solvent. Since the addition of solvent reduces the content of the effective component in the dispersant, the dispersibility at the same dosage is worse. Therefore, it is preferable that no additional solvent is needed.

[0094] Compared to Examples 1 and 6, Comparative Example 5 used a lower dropping temperature. The results in Table 1 show that the viscosity of the oil sample increased as the dropping temperature decreased. Lowering the dropping temperature leads to increased viscosity of the reaction solution, poorer stirring effect, and consequently, a worse reaction, affecting the formation of effective components and reducing product dispersibility.

[0095] Furthermore, in Example 7, N,N'-diphenyl-p-phenylenediamine was used instead of 4-aminodiphenylamine in Example 1. As shown in Table 1, the viscosity and impurity content of the corresponding product in Example 7 were significantly higher than those in Example 1. Therefore, in the preparation of the soot-free dispersant of this invention, 4-aminodiphenylamine is more preferable than N,N'-diphenyl-p-phenylenediamine.

[0096] In Example 8, n-butyraldehyde was used instead of paraformaldehyde in Example 1. According to Table 1, the impurity content of the corresponding product in Example 8 was similar to that in Example 1, but the viscosity was higher. Therefore, in the preparation of the soot-free dispersant of this invention, paraformaldehyde is a more preferred aldehyde compound than n-butyraldehyde.

[0097] Unless otherwise specified, the terms used in this invention have the meanings commonly understood by those skilled in the art.

[0098] The embodiments described in this invention are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Those skilled in the art can make various other substitutions, changes and improvements within the scope of this invention. Therefore, this invention is not limited to the above embodiments, but is only defined by the claims.

Claims

1. A method for preparing an ashless soot dispersant, characterized in that, Includes the following steps: S1: React fatty amines with polyisobutylene maleic anhydride to obtain an intermediate product; as well as S2: React the intermediate product with aldehydes and aromatic amines; The reaction process in step S1 includes: mixing the polyisobutylene maleic anhydride and base oil, and then adding the fatty amine; adding the fatty amine to the system in step S1 at a temperature of 100~135°C to carry out the reaction. The reaction temperature in step S1 is 90~170℃, and the reaction temperature in step S2 is 105~120℃, with the base oil as the reaction medium. The aromatic amine is selected from 4-aminodiphenylamine.

2. The method according to claim 1, characterized in that, During the reaction in step S2, the temperature variation does not exceed 10°C; and / or, The base oil is used in an amount of 20-50% of the total mass of the reaction system, which includes the base oil, the fatty amine, the polyisobutylene maleic anhydride, the aldehyde compound, and the aromatic amine; and / or, The base oil is selected from one or more API Group I, II, III, IV and V lubricating base oils.

3. The method according to claim 1, characterized in that, The aldehyde compounds include one or more of the following: aliphatic aldehydes, paraformaldehyde, benzaldehyde, and phenylacetaldehyde, which contain 1 to 10 carbon atoms.

4. The method according to claim 3, characterized in that, The fatty aldehydes include one or more of formaldehyde, acetaldehyde, butyraldehyde, pentanaldehyde, heptaldehyde, octanaldehyde, nonanaldehyde, and decanaldehyde.

5. The method according to claim 1, characterized in that, The fatty amine includes one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and hexaethyleneheptamine; and / or the polyisobutylene maleic anhydride has a number-average molecular weight of 500 to 5000.

6. The method according to claim 1, characterized in that, The number-average molecular weight of the polyisobutylene maleic anhydride is 900-2500.

7. The method according to claim 1, characterized in that, The molar ratio of the fatty amine to the polyisobutylene maleic anhydride is 1:1 to 1:2; and / or, The molar ratio of the fatty amine to the aldehyde compound is 1:2 to 2:1; and / or, The molar ratio of the fatty amine to the aromatic amine is 1:1 to 3:

1.

8. The method according to claim 1, characterized in that, The reaction time for step S1 is 2 to 6 hours, and the reaction time for step S2 is 5 to 10 hours.

9. An internal combustion engine oil comprising a soot-free dispersant prepared by any one of claims 1 to 8.

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