Macromolecular lubricating oil high-temperature antioxidant with multiple effects of dispersing soot and resisting oxidation and preparation method of macromolecular lubricating oil high-temperature antioxidant

Abstract

The invention belongs to the technical field of lubricating oil additives, and particularly relates to a macromolecular lubricating oil high-temperature antioxidant with soot dispersing and antioxidant multiple effects and a preparation method of the macromolecular lubricating oil high-temperature antioxidant. According to the macromolecular high-temperature antioxidant, aromatic amine and alkylphenol condensation compound antioxidant groups are introduced, and meanwhile PIBSA is combined with the macromolecular lubricating oil high-temperature antioxidant; the antioxidant is an ideal multi-effect macromolecular high-temperature-resistant antioxidant, not only has dual functions of oxidation resistance and soot dispersion, but also can ensure good oil solubility. The product structurally contains alkenyl succinimide or oleamide, condensed aromatic amine and an alkylphenol group connected with the condensed amine, has the characteristics of good high-temperature oxidation resistance, high thermal stability, dispersity and the like, and is suitable for preparing high-grade internal combustion engine oil.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating oil additives, and in particular relates to a macromolecular lubricating oil high-temperature antioxidant with multiple effects of dispersing soot and resisting oxidation, and a preparation method thereof. Background Art

[0002] With stricter environmental controls, the use of low-ash and low-phosphorus lubricants is being mandated. Consequently, the use of zinc dialkyl dithiophosphate (ZDDP) has been restricted. As a key engine oil additive, ZDDP is a multi-purpose additive with antioxidant, anti-corrosion, and anti-wear properties. However, since phosphorus can poison catalytic converters, reducing the phosphorus content in engine oils is crucial. For example, when formulating API SG-grade internal combustion engine oils, the phosphorus content is ideally controlled below 0.06%. Consequently, the addition of other antioxidant adjuvants is necessary to reduce the amount of ZDDP used. Aromatic amine antioxidants can be used in combination with ZDDP to effectively control changes in oil viscosity and acid value at high temperatures.

[0003] However, in recent years, antioxidants have achieved new structural breakthroughs, and large-molecule high-temperature antioxidants have become a development trend. So-called large-molecule antioxidants are composed of multiple antioxidant molecules condensed into one large molecule. Although their unit structure remains unchanged, the thermal stability and decomposition temperature are significantly improved after being linked into a large molecule, resulting in longer-lasting antioxidant properties and a longer induction period. On the other hand, the structural characteristics of the new soot dispersants developed in recent years are: one contains polycyclic aromatic hydrocarbons, such as benzene and naphthalene rings; the other is a high-molecular-weight polymer, i.e., a dispersing viscosity-enhancing agent with amino polar groups (such as DOCP and DPMA). Clearly, combining PIBSA with a phenolamine condensation large-molecule antioxidant would be an ideal multi-functional large-molecule high-temperature resistant antioxidant, with dual antioxidant and soot dispersing functions.

[0004] A search revealed that U.S. patents 4,636,322, 4,699,724, and 4,713,189 disclose coupled succinimide dispersants, prepared by coupling phenol, bisphenol A, resorcinol, and monononylphenol with succinimide via a Mannich reaction, followed by partial acylation of polyene polyamines with glycolic acid. This additive improves dispersibility and compatibility with rubber seals, but does not address improving oxidative stability. U.S. patent 4,863,623 discloses the use of maleic anhydride-grafted ethylene-propylene copolymers terminated with aromatic amines (such as 4-aminodiphenylamine) to control exhaust gas recirculation soot. U.S. patent 5,409,623 discloses functionalized graft copolymers as viscosity index improvers. These copolymers contain an ethylene-α-monoolefin copolymer grafted with an ethylene-unsaturated carboxylic acid and derivatized with an azo-containing aromatic amine compound. U.S. Patent No. 5,356,999 discloses multifunctional viscosity index improvers for lubricating oils. These viscosity index improvers comprise a polymer grafted with an unsaturated reactive monomer and then reacted with an amine containing a sulfonamide group. The polymer is either an ethylene-propylene copolymer or an ethylene-propylene-diene terpolymer. U.S. Patent No. 7,361,629 and U.S. Patent Application No. 2008 / 0171678 both disclose an amino product comprising a mixture of a water-divalent carbon-substituted succinic acid acylating agent and an aliphatic polyamine and an aromatic polyamine. The molar ratio of the aliphatic polyamine to the aromatic polyamine in the mixture ranges from 10:0.1 to 0.1:10.

[0005] In view of this, the inventors hope to provide a multi-effect high-temperature antioxidant with a macromolecular structure that is different from the molecular structure of existing products and can improve the soot dispersion performance and enhance the antioxidant performance. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned problems existing in traditional technologies and provide a macromolecular lubricant high-temperature antioxidant with multiple effects of dispersing soot and anti-oxidation and a preparation method thereof. The macromolecular lubricant high-temperature antioxidant has the following groups in its structure: alkenyl succinimide, condensed aromatic amine, and alkyl phenol connected to the condensed amine or the substitute referred to in this application.

[0007] In order to achieve the above technical objectives and effects, the present invention has three technical solutions:

[0008] Scheme 1: The present invention provides a method for preparing a macromolecular lubricant high-temperature antioxidant having multiple effects of dispersing soot and anti-oxidation. First, a phenolamine condensate and an imide compound are prepared separately, and then condensed. The specific steps are as follows:

[0009] 1) Aromatic amine, alkylphenol and aldehyde are reacted under certain conditions to generate a phenolamine condensation intermediate;

[0010] 2) Acidic compounds react with polyamines or polyene polyamines under certain conditions to produce amide or imide intermediates;

[0011] 3) The intermediate product of step 1) and step 2) is condensed with aldehyde to obtain the final macromolecular lubricant high-temperature and high-efficiency antioxidant.

[0012] Scheme 2: The present invention provides a method for preparing a macromolecular lubricant high-temperature antioxidant having multiple effects of dispersing soot and anti-oxidation, wherein a phenolamine condensate is condensed with an alkenyl succinimide intermediate product, and the specific steps are as follows:

[0013] 1) Aromatic amine, alkylphenol and aldehyde are reacted under certain conditions to generate a phenolamine condensation intermediate;

[0014] 2) Acidic compounds react with aromatic amines under certain conditions to produce alkenyl succinimide or oleamide intermediates;

[0015] 3) Condensing the intermediate products of step 1) and step 2) with formaldehyde to obtain the final macromolecular lubricant high-temperature and high-efficiency antioxidant.

[0016] Option three, the present invention provides a method for preparing a macromolecular lubricant high-temperature antioxidant with multiple effects of dispersing soot and anti-oxidation. The method adopts a one-step preparation method, and the specific steps are as follows: mixing an acidic compound, an aromatic amine, a polyene polyamine, an alkylphenol, and an aldehyde, and reacting them under certain conditions to obtain the final macromolecular lubricant high-temperature and high-efficiency antioxidant.

[0017] Furthermore, the reaction is carried out in a solvent or non-solvent system; wherein the solvent is selected from benzenes, alcohols, or a mixture thereof; the benzene is at least one of diluent oil, benzene, tert-butylbenzene, toluene, xylene, chlorobenzene, hexane, and tetrahydrofuran; the alcohol is at least one of methanol, ethanol, butanol, isopropanol, isooctyl alcohol, and dodecanol;

[0018] The reaction is carried out in air or inert gas; wherein, the inert gas is nitrogen or argon.

[0019] Furthermore, the alkylphenol is selected from at least one of 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2-tert-butylphenol, 2,4-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, nonylphenol, and dodecylphenol, or β-(3,5-di-tert-butyl-4-hydroxyphenyl)methyl acrylate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)isooctanol acrylate, and β-(3,5-di-tert-butyl-4-hydroxyphenyl)octadecyl acrylate.

[0020] Furthermore, the aromatic amine has a primary nitrogen atom or a secondary nitrogen atom, and one of the hydrocarbon substituents is a relatively short-chain alkyl group, that is, 4-phenylazoaniline, 4-aminodiphenylamine, diphenylamine, aniline, naphthylamine, 2-aminobenzimidazole, N,N-dimethylphenylenediamine, N-methylaniline, N-butylamine, bis-(p-methylphenyl)amine, 4-aminodiphenyl ether, 3-methylaniline, 4-aminoacetanilide, N-(4-amino-phenyl)acetamide, 4-amino-2-alkyl-benzoic acid phenyl ester (phenylaminosalicylate), N-(4-amino-phenyl)-benzamide, 2,5-dimethoxybenzylamine, 4-phenylazoaniline, p-aminophenethyl ether, p-dodecylaniline, cyclohexyl-substituted naphthylamine, thiophene-substituted aniline, and one of nonyldiphenylamine, dinonyldiphenylamine, and octyldiphenylamine.

[0021] Furthermore, the molar ratio of alkylphenol to aromatic amine is 1:1-6; the aldehyde substance is selected from C1-C4 polyaldehyde or aldehyde aqueous solution, and the molar ratio of its usage to the total of alkylphenol and aromatic amine is 2-5:1.

[0022] Furthermore, the aromatic amine condensate is an amine containing at least four aromatic groups and at least four -NH2 functional groups; the aromatic amine condensate is represented by the following formula (1) or formula (2):

[0023] (1)

[0024] (2)

[0025] The preparation method of the aromatic amine condensate comprises: mixing an aromatic amine and an aldehyde in a solvent or non-solvent system, in air or an inert gas, with or without a catalyst, to carry out a condensation reaction; wherein the catalyst is an inorganic acid, such as hydrochloric acid, sulfuric acid, or nitric acid, preferably a 1-3 mol / L hydrochloric acid solution; and the molar ratio of hydrochloric acid to aromatic amine is 1:2-4 or 2-4:1. The reaction temperature is 10-160°C, or the reaction is carried out under reflux of the solvent, for 2-16 hours. The mixture is then cooled to room temperature, and a 50 wt% sodium hydroxide aqueous solution is added for neutralization.

[0026] Furthermore, the alkenyl group in the alkenyl succinimide is a C2-C12 olefin copolymer, whose number average molecular weight is 300 to 5000 and the molecular weight distribution is 1.5 to 4.5; preferably, the isobutylene polymer has a number average molecular weight of 500 to 2500 and a molecular weight distribution of 1.5 to 3.5, and the amount added is 0.6 to 3 times the molar number of the phenolamine condensate.

[0027] The present invention also provides a macromolecular lubricating oil high-temperature antioxidant with multiple effects of dispersing soot and anti-oxidation, which is prepared by the preparation method of any one of the above-mentioned schemes 1 to 3.

[0028] The beneficial effects of the present invention are:

[0029] 1. The macromolecular high-temperature antioxidant provided by the present invention combines PIBSA with the antioxidant group of the condensation product of aromatic amine and alkylphenol at the same time, and is an ideal multi-effect macromolecular high-temperature antioxidant, which not only has the dual functions of antioxidant and soot dispersion, but also can ensure good oil solubility.

[0030] 2. The product structure of the present invention contains alkenyl succinimide or oleamide, condensed aromatic amine and alkylphenol group connected with condensed amine, and has the characteristics of good high-temperature oxidation resistance, high thermal stability and dispersibility, and is suitable for the preparation of high-grade internal combustion engine oil.

[0031] Of course, any product implementing the present invention does not necessarily need to achieve all of the above advantages at the same time. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0033] The present invention aims to provide a multi-effect high-temperature antioxidant with a macromolecular structure that differs from existing products in molecular structure, improving both soot dispersibility and antioxidant properties. This product is a macromolecular high-temperature antioxidant for lubricating oils that possesses both soot dispersibility and antioxidant properties. Its structure contains the following groups: alkenyl succinimide, a condensed aromatic amine, and an alkylphenol or its substitutes, as defined herein, linked to the condensed aromatic amine.

[0034] The technical solution of the present invention is:

[0035] Method 1: Multi-step reaction

[0036] In solvent or non-solvent system, under air or inert gas conditions:

[0037] 1.1 In the presence or absence of a catalyst, aromatic amine and aldehyde are mixed to undergo a condensation reaction, and then neutralized with a base to obtain an aromatic amine condensate;

[0038] 1.2 Aromatic amine condensate, alkylphenol and aldehyde are mixed, subjected to Mannich reaction, and the product is separated to obtain an intermediate product, amine-phenol condensate intermediate;

[0039] 1.3 Then, the alkenyl succinimide is subjected to a neutralization reaction with the above-mentioned aminophenol condensate to obtain the final macromolecular antioxidant product.

[0040] Method 2: One-pot cooking

[0041] In a solvent or non-solvent system, under air or inert gas conditions, alkylphenol, aromatic amine, aldehyde, inorganic acid and alkenyl succinimide raw materials are mixed and reacted, that is, a one-pot reaction is used to synthesize the macromolecular antioxidant product.

[0042] The specific preparation method of the macromolecular antioxidant is as follows:

[0043] 1. Method 1, step-by-step reaction

[0044] In solvent or non-solvent system, under air or inert gas conditions:

[0045] 1.1 Preparation of aromatic amine condensates

[0046] An aromatic amine and an aldehyde are mixed in the presence or absence of a catalyst to undergo a condensation reaction. The reaction temperature is 10-160°C, preferably under reflux, and the reaction time is 2-16 hours, preferably 2-8 hours. The mixture is then cooled to room temperature and neutralized by adding a sodium hydroxide solution having a mass ratio of 50 / 50 (sodium hydroxide / water). The mixture is then separated to obtain an aromatic amine condensate.

[0047] 1.2 Preparation of aminophenol condensation intermediates

[0048] The aromatic amine condensate prepared in 1.1 is mixed with an alkylphenol and an aldehyde, and the mixture is slowly heated under stirring. The mixture is reacted at 50-170°C, preferably 60-120°C, for 1-12 hours, preferably 2-8 hours. Water and unreacted substances are removed by reduced pressure distillation to obtain an amine-phenol condensate intermediate.

[0049] 1.3 Preparation of macromolecular antioxidants

[0050] The condensed aminophenol prepared in step 1.2 is reacted with alkenyl succinic anhydride at a reaction temperature of 50 to 170° C., preferably 60 to 150° C.; the reaction time is 1 to 10 hours, preferably 2 to 7 hours; the water generated by the reaction is removed under reduced pressure, and the reaction is filtered to obtain the final macromolecular antioxidant product.

[0051] 2. Method 2: One-pot cooking

[0052] In a solvent or non-solvent system, alkylphenol, aromatic amine, aldehyde, inorganic acid and alkenyl succinimide raw materials are mixed and reacted at a reaction temperature of 10 to 160°C, preferably 50 to 170°C; the reaction time is 1 to 20 hours, preferably 5 to 9 hours, and the solvent is removed and filtered to obtain the product, that is, a one-pot reaction method for synthesizing a macromolecular antioxidant product.

[0053] The solvent may be selected from diluent oil, benzene, tert-butylbenzene, toluene, xylene, chlorobenzene, hexane, tetrahydrofuran, or mixtures thereof. Alternatively, the solvent may be an alcohol, such as methanol, ethanol, butanol, isopropanol, isooctyl alcohol, dodecanol, or mixtures thereof. Alternatively, the solvent may be a mixture of an alcohol and a benzene.

[0054] The reaction can be carried out in air or inert gas. The inert gas is nitrogen or argon, preferably nitrogen.

[0055] The aromatic amines are those having a primary nitrogen atom (-NH2) or a secondary nitrogen atom, wherein one of the hydrocarbon substituents is a relatively short-chain alkyl group. Examples of the aromatic amines include 4-phenylazoaniline, 4-aminodiphenylamine, diphenylamine, aniline, naphthylamine, 2-aminobenzimidazole, N,N-dimethylphenylenediamine, N-methylaniline, N-butylamine, bis-(p-methylphenyl)amine, 4-aminodiphenyl ether, 3-methylaniline, 4-aminoacetanilide, N-(4-amino-phenyl)acetamide, 4-amino-2-alkyl-phenylbenzoate (phenylaminosalicylate), N-(4-amino-phenyl)-benzamide, 2,5-dimethoxybenzylamine, 4-phenylazoaniline, p-aminophenethyl ether, p-dodecylaniline, cyclohexyl-substituted naphthylamine, thiophene-substituted aniline, nonyldiphenylamine, dinonyldiphenylamine, and octyldiphenylamine.

[0056] The aldehyde substance is selected from C1-C4 polyaldehyde or aldehyde aqueous solution, preferably paraformaldehyde or formaldehyde aqueous solution, and the molar ratio of the amount thereof to the total amount of alkylphenol and aromatic amine is 2-5:1.

[0057] The catalyst is an inorganic acid, selected from hydrochloric acid, sulfuric acid, and nitric acid, preferably a 1-3 mol / L hydrochloric acid solution. The molar ratio of hydrochloric acid to aromatic amine is 1:2-4 or 2-4:1.

[0058] The alkylphenol is selected from 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2-tert-butylphenol, 2,4-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, nonylphenol, dodecylphenol, or a mixture of two or more thereof. β-(3,5-di-tert-butyl-4-hydroxyphenyl) methyl acrylate, β-(3,5-di-tert-butyl-4-hydroxyphenyl) acrylate (isooctanol), and β-(3,5-di-tert-butyl-4-hydroxyphenyl) acrylate (octadecyl acrylate) can also be used as substitutes. The condensation product of the alkylphenol and aromatic amine is used to synthesize an amide-type condensed aminophenol. The molar ratio of the alkylphenol (or 3,5-alkyl acrylate) to the aromatic amine is 1:1-6, preferably 1:1-4.

[0059] The aromatic amine condensate preferably contains an amine with at least four aromatic groups and at least four -NH2 functional groups, and is represented by the following formula (1) or formula (2):

[0060] (1)

[0061] (2)

[0062] During the phenolamine condensation reaction, alkylphenols can be linked to multiple aromatic amines based on their reactivity, either at primary or secondary nitrogen groups, or through a methylene group connected to a C—H bond on the benzene ring. The location and relative content of 2,6-di-tert-butylphenol in the product structure depend on the feed amount.

[0063] The alkenyl succinic anhydride is a C2-C12 olefin copolymer having a number average molecular weight of 300-5000 and a molecular weight distribution of 1.5-4.5. An isobutylene polymer is preferably used, having a number average molecular weight of 500-2500 and a molecular weight distribution of 1.5-3.5. The amount of the alkenyl succinic anhydride added is 0.6-3 times, preferably 0.75-2.5 times, the molar amount of the aminophenol condensate in step 1.2.

[0064] The macromolecular high-temperature antioxidant provided by the present invention combines antioxidant groups from an aromatic amine and alkylphenol condensate with PIBSA, creating an ideal multi-functional macromolecular high-temperature antioxidant that not only possesses both antioxidant and soot dispersing properties but also maintains excellent oil solubility. Specific embodiments of the present invention are as follows:

[0065] Examples 1 to 8 are the preparation of condensed amine phenol intermediates.

[0066] Examples 9 to 16 are the preparation of macromolecular multi-effect antioxidants.

[0067] Examples 17 and 18 are one-pot methods for synthesizing antioxidants.

[0068] Example 1

[0069] In a 1L four-necked flask equipped with a stirrer, add 300ml (0.2mol / L) hydrochloric acid, 46g (0.25mol) p-aminodiphenylamine, and 25g (0.30mol) 37% formaldehyde solution. Under nitrogen, heat to 90°C for 6 hours, then cool to room temperature. Neutralize with 50% aqueous NaOH solution, wash with water, and remove water to obtain an amine-amine condensate. Cool the mixture to 60°C, add 20.6g (0.1mol) 2,6-di-tert-butylphenol, and slowly heat to 120°C for 3 hours. Remove water and unreacted materials by distillation under reduced pressure to obtain the amine-phenol condensation intermediate 1.

[0070] Example 2

[0071] To a 1L four-necked flask equipped with a stirrer, add 46g (0.25mol) of p-aminodiphenylamine, 34g (0.2mol) of diphenylamine, 25g (0.30mol) of 37% formaldehyde solution, and 200ml of toluene. Under nitrogen, heat to 100°C and hold for 6 hours. Then, cool to room temperature, add 30.9g (0.15mol) of 2,6-di-tert-butylphenol, and slowly heat to 130°C and hold for 4 hours. Remove water and unreacted substances by distillation under reduced pressure to produce aminophenol condensation intermediate 2.

[0072] Example 3

[0073] To a 1L four-necked flask equipped with a stirrer, add 46g (0.25mol) of p-aminodiphenylamine, 28.4g (0.35mol) of 37% formaldehyde solution, and 100g of isopropanol. Under nitrogen, heat to 100°C and hold for 5 hours. Then, cool to room temperature, add 41.2g (0.2mol) of 2,6-di-tert-butylphenol, and slowly heat to 120°C and hold for 2 hours. Remove water and unreacted substances by distillation under reduced pressure to produce aminophenol condensation intermediate 3.

[0074] Example 4

[0075] To a 1L four-necked flask equipped with a stirrer, add 46g (0.25mol) of p-aminodiphenylamine, 19.5g of paraformaldehyde, and 150g of isooctyl alcohol. Under nitrogen, heat to 110°C and hold for 6 hours. Then, cool to room temperature, add 20.6g (0.1mol) of 2,6-di-tert-butylphenol, and slowly heat to 150°C and hold for 8 hours. Remove water and unreacted substances by distillation under reduced pressure to produce aminophenol condensation intermediate 4.

[0076] Example 5

[0077] To a 1L four-necked flask equipped with a stirrer, add 73.7g (0.4mol) of p-aminodiphenylamine and 20.27g (0.25mol) of a 37% formaldehyde solution. Under argon, heat to 60°C and hold for 3 hours. Then, cool to room temperature, add 20.6g (0.1mol) of 2,6-di-tert-butylphenol, and slowly heat to 90°C and hold for 5 hours. Remove water and unreacted substances by distillation under reduced pressure to produce aminophenol condensation intermediate 5.

[0078] Example 6

[0079] To a 1L four-necked flask equipped with a stirrer, add 73.7g (0.4mol) of p-aminodiphenylamine, 34g (0.2mol) of diphenylamine, 25g (0.30mol) of 37% formaldehyde solution, 200ml of tetrahydrofuran, and 61.8g (0.3mol) of 2,6-di-tert-butylphenol. Heat to 90°C for 6 hours, then slowly heat to 110°C for 10 hours. Remove water and unreacted materials by distillation under reduced pressure to produce condensed aminophenol intermediate 6.

[0080] Example 7

[0081] To a 1L four-necked flask equipped with a stirrer, 73.7g (0.4mol) of p-aminodiphenylamine, 34g (0.2mol) of diphenylamine, and 25g (0.30mol) of a 37% formaldehyde solution were added. 300ml of toluene was heated to 90°C under nitrogen and held for 6 hours. The mixture was then cooled to room temperature and 80g (0.2mol) of β-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylate was added. The mixture was slowly heated to 150°C and held for 7 hours. Water and unreacted substances were removed by distillation under reduced pressure to produce the condensed aminophenol intermediate 7.

[0082] Example 8

[0083] In a 1L four-necked flask equipped with a stirrer, 46g (0.25mol) of para-aminodiphenyl, 16.2g (0.20mol) of 37% formaldehyde solution, and 40g of β-(3,5-di-tert-butyl-4-hydroxyphenyl) methyl acrylate were added. The mixture was heated to 80°C and maintained for 4h. Then, the mixture was slowly heated to 160°C and maintained for 9h. Water and unreacted substances were removed by distillation under reduced pressure to obtain condensed aminophenol intermediate 8.

[0084] Example 9

[0085] In a 1L four-necked flask equipped with a stirrer, 150g of polyisobutylene succinic anhydride (molecular weight of polyisobutylene is 2300) and 75g of 150SN diluent oil were added, and the mixture was heated to 80°C under nitrogen protection. 25.5g of the condensed aminophenol intermediate 1 in Example 1 was added and maintained for 3h. The temperature was then raised to 150°C and maintained for 2h. The mixture was vacuum dehydrated for 2h and filtered to obtain the antioxidant product.

[0086] Example 10

[0087] The reaction conditions were the same as those in Example 9, except that the condensed amine phenol 2 in Example 2 was used instead of the condensed amine phenol 1, so that the molar ratio of PIBSA to the condensed amine phenol was 1.5:1, to obtain an antioxidant product.

[0088] Example 11

[0089] The reaction conditions were the same as those in Example 9, except that the condensed amine phenol intermediate 1 was replaced by the condensed amine phenol 3 in the same molar amount as in Example 3, and PIBSA having a polyisobutylene molecular weight of 1300 was used to prepare an antioxidant product.

[0090] Example 12

[0091] The reaction conditions were the same as those in Example 9, except that the condensed amine phenol intermediate 1 was replaced by the condensed amine phenol 4 with the same molar number as in Example 4, and PIBSA with a polyisobutylene molecular weight of 900 was used to prepare an antioxidant.

[0092] Example 13

[0093] The reaction conditions were the same as those in Example 9, except that the condensed amine phenol intermediate 1 was replaced by the condensed amine phenol 5 in the same molar amount as in Example 5, and PIBSA with a polyisobutylene molecular weight of 500 was used to prepare an antioxidant.

[0094] Example 14

[0095] The reaction conditions were the same as in Example 9, except that the condensed aminophenol intermediate 1 was replaced with the same molar amount of condensed aminophenol 6 as in Example 6 to prepare an antioxidant. PIBSA having a molecular weight of 1000 was used as the polyisobutylene.

[0096] Example 15

[0097] The reaction conditions were the same as those in Example 9, except that the condensed aminophenol intermediate 1 was replaced by the condensed aminophenol 7 of the same molar number as in Example 7, a polyisobutylene having a molecular weight of 500PIBSA was used, and no diluent oil was added to the reaction system to obtain an antioxidant.

[0098] Example 16

[0099] The amination conditions were the same as in Example 9, except that the condensed amine phenol intermediate 1 was replaced by the condensed amine phenol 8 in Example 8, the molar ratio of PIBSA to condensed amine phenol was 0.5:1, and PIBSA having a polyisobutylene molecular weight of 1000 was used to prepare an antioxidant.

[0100] Example 17

[0101] In a 1L four-necked flask equipped with a stirrer, add 73.7g (0.4mol) of p-aminodiphenylamine and 16.2g (0.20mol) of 37% formaldehyde solution. Then, add 20.6g (0.1mol) of 2,6-di-tert-butylphenol, 100ml of toluene, 50g of polyisobutenyl succinic anhydride (polyisobutene has a molecular weight of 1300), and 50g of 15OSN diluent oil. Under nitrogen protection, heat to 80°C and hold for 4 hours. Then, slowly heat to 120°C and hold for 3 hours. Then heat to 150°C and hold for 5 hours. Remove water and unreacted substances by distillation under reduced pressure to obtain the final antioxidant product.

[0102] Example 18

[0103] In a 1L four-necked flask equipped with a stirrer, add 46g (0.25mol) of p-aminodiphenylamine, 17g (0.1mol) of diphenylamine, and 28.4g (0.35mol) of a 37% formaldehyde solution. Then, add 50g of β-(3,5-di-tert-butyl-4-hydroxyphenyl) acrylate and 100g of polyisobutenyl succinic anhydride (polyisobutene having a molecular weight of 1000). Under no nitrogen protection, heat to 120°C for 4 hours, then slowly heat to 140°C for 3 hours, and then heat to 170°C for 5 hours. Remove water and unreacted substances by distillation under reduced pressure to obtain the final antioxidant product.

[0104] The above descriptions only describe some exemplary embodiments of the present invention. However, those skilled in the art will appreciate that various modifications may be made to the exemplary embodiments without departing from the essential novelties and advantages of the present invention. For example, PIBSA may be first subjected to an amination reaction with a condensed amine, and then condensed with 2,6-di-tert-butylphenol in a formaldehyde solution or paraformaldehyde to produce the final product. Therefore, similar modifications based on the above description are encompassed within the scope of the present invention as defined by the claims.

[0105] Comparative Example 1

[0106] This comparative example is a common single-hang ashless dispersant (commercially available T151), and its performance evaluation is shown in Table 1.

[0107] Comparative Example 2

[0108] This comparative example is a common double-hang ashless dispersant (commercially available T154), and its performance evaluation is shown in Table 1.

[0109] Comparative Example 3

[0110] This comparative example is an antioxidant (commercially available T557) prepared by alkylation of diisobutylene and diphenylamine. Its performance evaluation is shown in Table 1.

[0111] Comparative Example 4

[0112] This comparative example is an antioxidant (commercially available T502) prepared by alkylation of isobutylene and phenol. Its performance evaluation is shown in Table 1.

[0113] Example 19

[0114] This example is about the evaluation of dispersion performance (SDT value).

[0115] Using carbon black as a soot simulant, a mixture of 5% additive, 2% carbon black sludge, and 93% 150SN base oil was stirred between room temperature and 100°C for 30 minutes, then placed in a 90°C oven for 2 hours. The higher the SDT value, the better the dispersibility. See Table 1 for test results.

[0116] Example 20

[0117] This example is about the evaluation of antioxidant performance.

[0118] The additive's oxidation induction period (PIT) was measured using a pressure differential scanning calorimeter (PDSC). A higher value indicates better antioxidant performance. The test conditions were: using a US DuPont 2100 instrument, 0.2% sample was added to a 5 cSt base oil, heated at a rate of 100°C / min, and maintained at a constant temperature of 180°C for 2 minutes in a high-purity oxygen atmosphere at a pressure of 3.5 MPa. The test results are shown in Table 1 below.

[0119] Example 21

[0120] This example is a thermal decomposition temperature (TGA) evaluation.

[0121] Heat the sample from 50°C to 600°C at a rate of 10°C / min, using 50ml / min of nitrogen as the working gas. Record the change in sample mass with temperature. The higher the TGA value, the better.

[0122] Table 1 Performance evaluation data

[0123]

[0124] As can be seen from Table 1, the macromolecular multi-effect high-temperature antioxidant provided by the present invention has not only stronger antioxidant performance and thermal decomposition temperature, but also improved dispersion performance compared with ordinary single-hanging and double-hanging ashless dispersants and aromatic amine and alkylphenol antioxidants.

[0125] The macromolecular multi-effect high-temperature lubricating oil antioxidant of the present invention exhibits excellent performance and utility in lubricating oils and fuel oils. Lubricating oils include passenger car engine oils, heavy-duty diesel engine oils, railway locomotive oils, natural gas engine oils, turbine oils, rust and oxidation inhibitors, railroad oils, hydraulic oils, automatic / manual lubricating fluids, greases, industrial gear oils, and automotive gear oils. Fuel oils include jet fuel, gasoline, and diesel.

[0126] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a macromolecular lubricant high-temperature antioxidant having multiple effects of dispersing soot and anti-oxidation, characterized in that: First, prepare the phenolamine condensate and the imide compound separately, and then condense them. The specific steps are as follows: 1) Aromatic amine, alkylphenol and aldehyde are reacted under certain conditions to generate a phenolamine condensation intermediate; 2) The acidic compound reacts with polyamine or polyene polyamine under certain conditions to produce an amide or imide intermediate; 3) The intermediate product of step 1) and step 2) is condensed with aldehyde to obtain the final macromolecular lubricating oil high-temperature and high-efficiency antioxidant.

2. A method for preparing a macromolecular lubricant high-temperature antioxidant having multiple effects of dispersing soot and anti-oxidation, characterized in that: The phenolamine condensate is condensed with the alkenyl succinimide intermediate product, and the specific steps are as follows: 1) Aromatic amine, alkylphenol and aldehyde are reacted under certain conditions to generate a phenolamine condensation intermediate; 2) Acidic compounds react with aromatic amines under certain conditions to produce alkenyl succinimide or oleamide intermediates; 3) Condensing the intermediate product of step 1) and step 2) with formaldehyde to obtain the final macromolecular lubricating oil high-temperature and high-efficiency antioxidant.

3. A method for preparing a macromolecular lubricant high-temperature antioxidant having multiple effects of dispersing soot and anti-oxidation, characterized in that: The one-step preparation method is as follows: an acidic compound, aromatic amine, polyene polyamine, alkylphenol and aldehyde are mixed and reacted under certain conditions to obtain the final macromolecular lubricant high-temperature and high-efficiency antioxidant.

4. The preparation method according to any one of claims 1 to 3, characterized in that The reaction is carried out in a solvent or non-solvent system; wherein the solvent is selected from benzenes, alcohols or a mixture of the two; the benzene is at least one of diluent oil, benzene, tert-butylbenzene, toluene, xylene, chlorobenzene, hexane, and tetrahydrofuran; the alcohol is at least one of methanol, ethanol, butanol, isopropanol, isooctyl alcohol, and dodecanol; The reaction is carried out in air or inert gas; wherein, the inert gas is nitrogen or argon.

5. The preparation method according to any one of claims 1 to 3, characterized in that The alkylphenol is selected from at least one of 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2-tert-butylphenol, 2,4-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, nonylphenol, and dodecylphenol, or β-(3,5-di-tert-butyl-4-hydroxyphenyl)methyl acrylate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)isooctanol acrylate, and β-(3,5-di-tert-butyl-4-hydroxyphenyl)octadecyl acrylate.

6. The preparation method according to any one of claims 1 to 3, characterized in that The aromatic amine has one primary nitrogen atom or one secondary nitrogen atom, and one of the hydrocarbyl substituents is a relatively short-chain alkyl group, i.e., 4-phenylazoaniline, 4-aminodiphenylamine, diphenylamine, aniline, naphthylamine, 2-aminobenzimidazole, N,N-dimethylphenylenediamine, N-methylaniline, N-butylamine, bis-(p-methylphenyl)amine, 4-aminodiphenyl ether, 3-methylaniline, 4-aminoacetanilide, N-(4-amino-phenyl)acetamide, 4-amino-2-alkyl-benzoic acid phenyl ester (phenylaminosalicylate), N-(4-amino-phenyl)-benzamide, 2,5-dimethoxybenzylamine, 4-phenylazoaniline, p-aminophenethyl ether, p-dodecylaniline, cyclohexyl-substituted naphthylamine, thiophene-substituted aniline, and one of nonyldiphenylamine, dinonyldiphenylamine, and octyldiphenylamine.

7. The preparation method according to any one of claims 1 to 3, characterized in that The molar ratio of alkylphenol to aromatic amine is 1:1-6; the aldehyde substance is selected from C1-C4 polyaldehyde or aldehyde aqueous solution, and the molar ratio of its usage to the total amount of alkylphenol and aromatic amine is 2-5:

1.

8. The preparation method according to any one of claims 1 to 3, characterized in that The aromatic amine condensate is an amine containing at least four aromatic groups and at least four -NH2 functional groups; the aromatic amine condensate is represented by the following formula (1) or formula (2): The preparation method of the aromatic amine condensate comprises the following steps: in a solvent or non-solvent system, under air or inert gas conditions, in the presence or absence of a catalyst, mixing aromatic amine and aldehyde substances to carry out a condensation reaction; wherein the catalyst is an inorganic acid, such as hydrochloric acid, sulfuric acid, or nitric acid, preferably a 1-3 mol / L hydrochloric acid solution; the molar ratio of hydrochloric acid to aromatic amine is 1:2-4 or 2-4:1; the reaction temperature is 10-160°C, or the reaction is carried out under solvent reflux, and the reaction time is 2-16 hours; then the mixture is cooled to room temperature, and a 50 wt% sodium hydroxide aqueous solution is added thereto for neutralization reaction.

9. The preparation method according to claim 2, characterized in that The alkenyl group in the alkenyl succinimide is a C2-C12 olefin copolymer, with a number average molecular weight of 300 to 5000 and a molecular weight distribution of 1.5 to 4.5; preferably, the isobutylene polymer has a number average molecular weight of 500 to 2500 and a molecular weight distribution of 1.5 to 3.5, and the added amount is 0.6 to 3 times the molar number of the phenolamine condensate.

10. A macromolecular high-temperature antioxidant for lubricating oil having multiple effects of dispersing soot and resisting oxidation, prepared by the preparation method according to any one of claims 1 to 3.

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