Imide compounds, processes for their preparation and use

Abstract

The present application relates to the technical field of rust inhibitor and / or antioxidant, and discloses an imide compound, a preparation method and application thereof, and a composition with rust-proof and / or antioxidant function.The imide compound has a structure shown in formula (I), wherein R0 is a C3-C20 hydrocarbon group; Y is a group having a structure shown in formula (II), wherein * represents a bonding site with a nitrogen atom in formula (I); m is an integer of 1-10; R1 in the m repeating units is independently a C1-C20 straight-chain or branched-chain alkylene group; T in the m repeating units is independently a C3-C10 nitrogen-containing heterocyclic group; and R2 is selected from H, a C1-C20 straight-chain or branched-chain alkyl group, or R2 is absent.The imide compound has excellent rust-proof and / or antioxidant performance, especially good compatibility with ester base oil, can synergistically play a role, and further improve the rust-proof and / or antioxidant performance.

Description

Technical Field

[0001] This invention relates to the field of rust inhibitors and / or antioxidants, specifically to an imide compound, its preparation method and application, and compositions having rust-inhibiting and / or antioxidant functions. Background Technology

[0002] Lubricating oil is currently the most widely used lubricating material, primarily serving functions such as lubrication, cooling, rust prevention, cleaning, sealing, and buffering. Lubricating oil generally consists of two parts: base oil and additives. Base oil is the main component, determining the basic properties of the lubricating oil, while additives compensate for and improve the shortcomings of the base oil, imparting certain new properties, and are also an important component of lubricating oil. Ester base oils have excellent low-temperature performance, good lubrication performance, high degradation rate, and long service life, and are receiving increasing attention and wider application. However, their rust prevention properties are relatively poor, so rust inhibitors are usually added to improve their rust-preventive performance.

[0003] Currently, commonly used rust inhibitors in lubricating oils include petroleum sulfonates, carboxylic acids, and esters. These rust inhibitors still suffer from drawbacks such as complex processing, severe pollution, low yield, limited performance, single function, and less than ideal rust prevention in ester-based oils. Furthermore, with societal development, the requirements for the oxidation resistance of lubricating oils are becoming increasingly stringent. To address these shortcomings, actively developing green, environmentally friendly, low-pollution, and high-performance multifunctional additives is the future trend and direction of additive development.

[0004] US5382667A discloses a compound obtained by reacting an alkenyl-substituted succinic anhydride with 4-(2-aminoethyl)morpholinone or hydroxyethyl ethylenediamine, for use in obtaining a concentrate of metalworking fluid, particularly for corrosion prevention.

[0005] US6043199A discloses a turbine oil composition comprising a synthetic ester base oil and a corrosion inhibitor, wherein the first component of the additive is a dicarboxylic acid, and the second component is (a) a hydroxyl derivative of a straight-chain or branched alkyl or alkenyl succinic acid / anhydride ester or half-ester or a succinic acid / anhydride ester or half-ester and (b) a straight-chain or branched alkyl or alkenyl substituted succinimide or succinamide or a mixture thereof or an amino-substituted succinimide, or succinamide or a mixture thereof, wherein component (b) is generated by reacting a straight-chain or branched alkyl or alkenyl substituted succinic anhydride with a substituted aminoimidazoline, thereby obtaining corrosion resistance.

[0006] CN101993743B discloses an additive composition comprising an aromatic amine antioxidant and / or a hindered phenolic antioxidant, an acylating agent containing two acyl groups in the component molecule reacting with ammonia and / or amine in a molar ratio of 1:(0.5-2) to form an ammonolysis product, a metal passivating agent, a diesel composition containing the additive composition, and a method for improving the oxidation stability of biodiesel using the additive composition. The diesel composition has good oxidation stability.

[0007] CN112442398A discloses a biodiesel antioxidant containing alkenyl succinimide and / or alkenyl succinamide, which has good antioxidant properties and good solubility in biodiesel.

[0008] However, the synthesis steps of the aforementioned imide substances are complicated, and their anti-corrosion performance is poor when used alone. They need to be combined with other corrosion inhibitors to further improve their anti-corrosion performance. Furthermore, there are currently no reports on the use of the aforementioned imide substances as rust inhibitors. Summary of the Invention

[0009] The purpose of this invention is to overcome the technical problems existing in the prior art and to provide an imide compound, its preparation method and application, as well as a composition with anti-rust and / or antioxidant functions.

[0010] To achieve the above objectives, a first aspect of the present invention provides an imide compound having the structure shown in formula (I).

[0011]

[0012] In formula (I), R0 is a C3-C20 hydrocarbon group; Y is a group having the structure shown in formula (II).

[0013]

[0014] In formula (II), * indicates the site where the nitrogen atom in formula (I) is bonded; m is an integer from 1 to 10; R1 in each of the m repeating units is independently a straight-chain or branched alkylene group of C1-C20; T in each of the m repeating units is independently a nitrogen-containing heterocyclic group of C3-C10; R2 is selected from H, straight-chain or branched alkyl group of C1-C20, or R2 is not present.

[0015] A second aspect of the present invention provides a method for preparing an imide compound, the method comprising: contacting a compound of formula (IV) with a compound of formula (V) to perform an imidization reaction;

[0016]

[0017] In formula (IV), R0' is a C3-C20 hydrocarbon group;

[0018] In formula (V), m is a positive integer from 1 to 10; R1' in each of the m repeating units is independently a straight-chain or branched alkylene group of C1-C20; T in each of the m repeating units is independently a nitrogen-containing heterocyclic group of C3-C10; R2' is selected from H, straight-chain or branched alkyl group of C1-C20, or R2' is not present.

[0019] A third aspect of the present invention provides the use of the aforementioned imide compounds or the methods described in the aforementioned methods in rust inhibitors and / or antioxidants.

[0020] A fourth aspect of the present invention provides a composition having rust-preventive and / or antioxidant functions, the composition comprising: a base oil comprising the aforementioned imide compound or a product of an imidization reaction prepared according to the aforementioned method.

[0021] The fifth aspect of the present invention provides the application of the aforementioned imide compounds or the aforementioned methods in improving the rust prevention and / or antioxidant properties of ester base oils.

[0022] The imide compounds provided by this invention have excellent rust prevention and / or antioxidant properties, which are better than those of the commonly used rust inhibitor T747A (alkenyl succinate) in ester oils. Therefore, they can be used as additives for lubricating oils, especially with good compatibility with ester base oils, which can work synergistically to further improve rust prevention and / or antioxidant properties. Attached Figure Description

[0023] Figure 1 The infrared spectrum of product 1 in Example 1 of this invention;

[0024] Figure 2 This is the mass spectrum of product 1 in Example 1 of the present invention;

[0025] Figure 3 The infrared spectrum of product 2 in Example 2 of this invention;

[0026] Figure 4 This is the mass spectrum of product 2 in Example 2 of the present invention. Detailed Implementation

[0027] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] In this invention, "C3-C20 hydrocarbon group" refers to a branched or straight-chain alkyl, alkenyl, or alkynyl group with 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms. "C1-C6 straight-chain or branched alkylene group" refers to methyl, ethyl, n-propyl, isopropyl, n-butyl, or isobutyl.

[0029] "C3-C10 nitrogen-containing heterocyclic group" means a nitrogen-containing heterocycle with 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. This nitrogen-containing heterocycle may also contain other heteroatoms, such as O or S.

[0030] A first aspect of the present invention provides an imide compound having the structure shown in formula (I).

[0031]

[0032] In formula (I), R0 is a C3-C20 hydrocarbon group; Y is a group having the structure shown in formula (II).

[0033]

[0034] In formula (II), * denotes the site where the nitrogen atom in formula (I) is bonded; m is an integer from 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10); R1 in each of the m repeating units is independently a straight or branched chain of C1-C20 (with 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms). Alkylene; each of the m repeating units is independently a nitrogen-containing heterocyclic group of C3-C10; R2 is selected from H, C1-C20 (with 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms) straight-chain or branched alkyl, or R2 is absent (the absence of R2 means that there is no chemical bond or arbitrary group between R2 and T).

[0035] According to some embodiments of the present invention, in formula (I), R0 can be a hydrocarbon group of C6-C18, preferably a hydrocarbon group of C9-C18, and more preferably a hydrocarbon group of C12-C18.

[0036] According to some embodiments of the present invention, in formula (II), m can be an integer from 1 to 5, preferably 1 or 2; R1 in each of the m repeating units can be independently C1-C10 straight-chain or branched alkylene groups, preferably C1-C6 (more preferably C1-C4) straight-chain or branched alkylene groups; T in each of the m repeating units can be independently C3-C6 nitrogen-containing heterocyclic groups.

[0037] According to some embodiments of the present invention, T has the structure shown in formula (III).

[0038]

[0039] In formula (III), R3 and R4 can each be independently a straight-chain or branched alkylene group of C1-C9, preferably a straight-chain or branched alkylene group of C1-C6 (more preferably C1-C4), and the sum of the carbon atoms of R3 and R4 is an integer from 3 to 10 (e.g., 3, 4, 5, 6, 7, 8, 9, 10), preferably an integer from 3 to 8; A is O or NR5, and R5 is selected from H, a straight-chain or branched alkyl group of C1-C6 (more preferably C1-C4).

[0040] According to some embodiments of the present invention, the imide compound has the structure shown in formula (I'):

[0041]

[0042] In formula (I'), X is NH or O; n is an integer from 0 to 6; L is a C1-C18 straight-chain or branched alkylene group (with 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 carbon atoms) or does not exist; Q is... Or it may not exist; when Q is When p is an integer from 0 to 18 (e.g., 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18); R6, R7 and R8 are each independently selected from H, C1-C6 alkyl groups (more preferably C1-C4 alkyl groups);

[0043] Preferably, the sum of the number of carbon atoms in L and the value of p is an integer not less than 8 and not greater than 20 (such as 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20).

[0044] According to some embodiments of the present invention, the imide compound has the structure shown in formula (I”):

[0045]

[0046] In formula (I”), X can be NH or O; n is an integer from 0 to 6 (0, 1, 2, 3, 4, 5, 6); L is absent or a straight-chain or branched alkylene group of C1-C6 (more preferably C1-C4); p is an integer from 6 to 15 (6, 7, 8, 9, 10, 11, 12, 13, 14, 15); R6, R7 and R8 are each independently selected from H and C1-C6 alkyl groups.

[0047] According to some embodiments of the present invention, the imide compound may be selected from at least one of the following compounds:

[0048]

[0049] In formulas (M1)-(M3), the groups in parentheses indicate that the double bond can be in any position (including the case where the double bond is directly connected to the succinimide ring). In formulas (M1) and (M2), the end of the group in parentheses is preferably isopropyl.

[0050] According to some embodiments of the present invention, the imide compound may be selected from at least one of the following compounds:

[0051]

[0052] A second aspect of the present invention provides a method for preparing an imide compound, the method comprising: contacting a compound of formula (IV) with a compound of formula (V) to perform an imidization reaction;

[0053]

[0054] In formula (IV), R0' can be a C3-C20 hydrocarbon group;

[0055] In formula (V), m can be a positive integer from 1 to 10; each of the m repeating units R1' is independently a C1-C20 straight-chain or branched alkylene group; each of the m repeating units T is independently a C3-C10 nitrogen-containing heterocyclic group; R2' is selected from H, C1-C20 straight-chain or branched alkylene groups, or R2 is not present (R2' is not present means that there is no chemical bond or arbitrary group between R2' and T).

[0056] According to some embodiments of the present invention, in formula (IV), R0' can be a C6-C18 hydrocarbon group, preferably a C9-C18 hydrocarbon group, and more preferably a C12-C18 hydrocarbon group.

[0057] According to some embodiments of the present invention, in formula (V), m is an integer from 1 to 5, preferably 1 or 2; R1' in each of the m repeating units is independently a straight-chain or branched alkylene group of C1-C10, preferably a straight-chain or branched alkylene group of C1-C6 (more preferably C1-C4); T in each of the m repeating units is independently a nitrogen-containing heterocyclic group of C3-C6.

[0058] The structure of T described in the second aspect of the present invention is as previously described and will not be repeated here.

[0059] According to a preferred embodiment of the present invention, the method comprises: contacting the compound represented by formula (VI) with the compound represented by formula (VII) to perform an imidization reaction:

[0060]

[0061] In formula (VI) or formula (VII), X is NH or O; n is an integer from 0 to 6; L is absent or is a straight-chain or branched alkylene group of C1-C6; p is an integer from 6 to 15; R6, R7 and R8 are each independently selected from H and C1-C6 alkyl groups.

[0062] According to some embodiments of the present invention, the compound shown in formula (IV) may be selected from one of octyl succinic anhydride, nonyl succinic anhydride, decyl succinic anhydride, dodecyl succinic anhydride, tridecyl succinic anhydride, tetradecyl succinic anhydride, pentadecyl succinic anhydride, hexadecyl succinic anhydride, octadecyl succinic anhydride, eicosyl succinic anhydride, octenyl succinic anhydride, nonenyl succinic anhydride, decenyl succinic anhydride, dodecenyl succinic anhydride, tetradecenyl succinic anhydride, pentadecenyl succinic anhydride, hexadecenyl succinic anhydride, octadecenyl succinic anhydride, and isooctadecenyl succinic anhydride.

[0063] According to some embodiments of the present invention, the compound shown in formula (V) is selected from 4-aminomorpholine, 3-methyl-4-aminomorpholine, 4-(2-aminomethyl)morpholine, 4-(2-aminoethyl)morpholine, 3-methyl-4-(2-aminoethyl)morpholine, N-(3-aminopropyl)morpholine, 4-morpholinebutamine, 1,4-bis-(3-aminopropyl)piperazine, N-(3-aminopropyl)piperazine, 1,4-piperazine diethylamine, 1-(2-aminoethyl)piperazine, 2-methyl-1-(2-aminoethyl)piperazine, 1,4-piperazine dimethylamine, piperazine-1-methylamine, 1,4-diaminopiperazine, 2-methyl-1,4-piperazine diamine, 2-(2-methylpiperazin-1-yl)-1-ethylamine, 2-methyl-2-(4-morpholine)propylamine, and 2-(2-methylmorpholine-4-yl)ethane-1-amine.

[0064] According to some embodiments of the present invention, the compound represented by formula (IV) is dodecenyl succinic anhydride or isooctadecenyl succinic anhydride, and the compound represented by formula (V) is 4-(2-aminoethyl)morpholine or 1-(2-aminoethyl)piperazine.

[0065] Preferably, the compound represented by formula (IV) is isooctadecenylsuccinic anhydride, and the compound represented by formula (V) is 4-(2-aminoethyl)morpholine; or,

[0066] The compound shown in formula (IV) is isooctadecenylsuccinic anhydride, and the compound shown in formula (V) is 1-(2-aminoethyl)piperazine; or,

[0067] The compound shown in formula (IV) is dodecenylsuccinic anhydride, and the compound shown in formula (V) is 1-(2-aminoethyl)piperazine.

[0068] The present invention does not impose any particular limitations on the conditions of the imidization reaction, as long as they meet the requirements of the present invention. Preferably, the temperature of the imidization reaction is 40-180°C, more preferably 50-160°C; and the time is 0.5-20 h, more preferably 1-15 h.

[0069] According to some embodiments of the present invention, the molar ratio of the compound shown in formula (IV) to the compound shown in formula (V) may be 1:(0.3-2), preferably 1:(0.4-1.5).

[0070] In this invention, there are no particular restrictions on the feeding method for the imide reaction, as long as it meets the requirements of this invention. To obtain better results, the feeding method for the imide reaction can be as follows: adding (preferably dropwise) the material containing the compound shown in formula (V) to the material containing the compound shown in formula (IV). The addition rate of the compound shown in formula (V) relative to 1 mol of the compound shown in formula (IV) is 0.01-0.04 mol / min.

[0071] According to some embodiments of the present invention, the imidization reaction is carried out under an inert atmosphere provided by an inert gas and / or nitrogen.

[0072] In this invention, the imidization reaction is carried out in the presence of a solvent. The solvent is preferably a hydrocarbon solvent, for example, a C6-C10 aromatic hydrocarbon, preferably at least one selected from toluene, o-xylene, m-xylene, p-xylene, and ethylbenzene.

[0073] In this invention, there is no particular limitation on the amount of solvent used, and it is preferable to use an amount that promotes the smooth progress of the reaction. For example, the amount of solvent can be 0.5-2 times the total weight of the compounds shown in formula (IV) and formula (V). The solvent can be removed after the reaction is complete by conventional methods in the art, such as distillation or fractional distillation. In this invention, before removing the solvent, the post-reaction system can be dehydrated (e.g., using a water separator); the dehydration step can be carried out in accordance with conventional methods in the art, such as gradually increasing the temperature of the post-reaction system.

[0074] According to the present invention, after the imide reaction is completed, the reaction product can be purified. The purification method may include at least one of the following methods: water washing, distillation, rectification, molecular distillation, filtration, drying and recrystallization, without particular limitation.

[0075] According to the present invention, the reaction products of the imide reaction can be a single imide compound or a mixture of multiple imide compounds. The different forms in which the reaction products of these imide reactions exist do not affect the effectiveness of the present invention. Therefore, according to the present invention, purification post-treatment (column chromatography or preparative chromatography as the purification or separation method) can be performed, or no further purification may be necessary. Of course, such purification or separation is preferred for further enhancing the effectiveness of the present invention.

[0076] The method for preparing imidization reaction provided by this invention has the advantages of simple process, mild conditions and safety and non-toxicity.

[0077] A third aspect of the present invention provides the use of the aforementioned imide compounds or the methods described in the aforementioned methods in rust inhibitors and / or antioxidants.

[0078] In particular, the imide compounds provided by this invention can be used as additives (such as rust inhibitors and / or antioxidants) for ester base oils.

[0079] A fourth aspect of the present invention provides a composition having rust-preventive and / or antioxidant functions, the composition comprising: a base oil comprising the aforementioned imide compound or a product of an imidization reaction prepared according to the aforementioned method.

[0080] According to some embodiments of the present invention, the content of base oil may be 94-99.5 wt% and the content of imide compound may be 0.19-0.98 wt% based on the total weight of the composition.

[0081] According to some embodiments of the present invention, the weight of the imide compound relative to 1 kg of base oil can be 2-10 g, preferably 4-8 g.

[0082] According to some embodiments of the present invention, the base oil may be an ester base oil, preferably a neopentyl polyol ester base oil. More preferably, the ester base oil is formed by the condensation of an alcohol and a carboxylic acid.

[0083] The alcohol is a polyol having the formula (VI), and the carboxylic acid is a saturated monocarboxylic acid having 4-20 carbon atoms.

[0084]

[0085] In equation (VI), R9, R 10 R 11 R 12 Each is independently selected from H, C1-C10 alkyl or hydroxyl groups, and R9, R 10 R 11 R 12At least two of them are hydroxyl groups.

[0086] According to some embodiments of the present invention, the composition may also contain antioxidants and / or extreme pressure anti-wear agents.

[0087] According to some embodiments of the present invention, the content of the antioxidant may be 0.1-4 wt% and the content of the extreme pressure anti-wear agent may be 0.2-1.5 wt% based on the total weight of the composition.

[0088] According to some embodiments of the present invention, the antioxidant is selected from at least one of aminothioesters, alkylated diphenylamine, N-phenyl-α-naphthylamine, and shielding phenols.

[0089] According to some embodiments of the present invention, the extreme pressure anti-wear agent may be selected from phosphate esters and / or phosphate ester amine salts. The extreme pressure anti-wear agent is preferably at least one selected from di-n-butyl phosphite, tricresyl phosphate, and isooctyl phosphate octadecylamine salt.

[0090] According to some embodiments of the present invention, the ester base oil may be selected from at least one of neopentyl glycol ester, trimethylolpropane ester, and pentaerythritol ester.

[0091] A fifth aspect of the present invention provides the application of the aforementioned imide compounds or the aforementioned methods in improving the rust prevention and / or antioxidant properties of ester base oils. The imide compounds and methods are as described above.

[0092] The present invention will be described in detail below through embodiments.

[0093] In the following examples, unless otherwise specified, all raw materials and solvents used were commercially available.

[0094] Example 1

[0095]

[0096] Add a toluene solution of isooctadecenylsuccinic anhydride (35.09 g + 70.03 g toluene) to a three-necked flask, and install a mechanical stirrer, a nitrogen delivery tube, and a constant-pressure dropping funnel; prepare a toluene solution of 4-(2-aminoethyl)-morpholine (11.97 g + 26.00 g toluene), and pour the toluene solution of 4-(2-aminoethyl)-morpholine into the constant-pressure dropping funnel; place the three-necked flask... Place the mixture in a constant-temperature oil bath at 5°C, turn on the mechanical stirrer and purge with nitrogen for 30 minutes; stop purging with nitrogen and add a toluene solution of 4-(2-aminoethyl)-morpholine dropwise to a three-necked flask; after the addition is complete, which takes 35 minutes, remove the constant-pressure dropping funnel and replace it with a water separator and condenser containing toluene. Heat the oil bath to 60°C and hold it at that temperature for 2 hours, then heat it to 90°C and hold it at that temperature for 2 hours, and finally heat it to 150°C until no more water condenses in the water separator. Rotary evaporate the mixture after the reaction to remove the toluene, giving product 1 (a product containing the compound with the structure shown in formula (a) above).

[0097] Infrared spectroscopy of product 1 was performed, see... Figure 1 .

[0098] Infrared spectroscopy measurement conditions:

[0099] Instrument Model: Thermo Fisher Scientific NICOLET IS50 (USA); Instrument Specifications: 16 scans, 4cm resolution -1 Scanning range 4000-400cm -1 The above products are produced using the coating method.

[0100] Figure 1 Middle, 1772cm -1 and 1699cm -1 The peaks represent the symmetric and asymmetric stretching vibrations of the carbonyl C=O group of cyclic imides, at 1206 cm⁻¹. -1 The peak for the CN stretching vibration of cyclic imides is 978 cm⁻¹. -1 The peak corresponds to the out-of-plane bending vibration of the =CH trans configuration of the double bond. The above infrared spectroscopy results indicate that product 1 contains cyclic imide groups and double bonds.

[0101] Product 1 was analyzed by mass spectrometry, see [see details]. Figure 2 .

[0102] The mass spectrometry determination conditions are as follows:

[0103] Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), model Bruker SolariX XR, magnetic field strength 15T. Experimental conditions: injection rate 120 μL / h, electrospray ionization source, positive ion mode (ESI+), capillary voltage 4500 V, nebulizer 1 bar, drying gas flow rate 4.0 L / min, desiccator temperature 200 °C, TOF 0.6 ms, Q1 mass 150 u, RF 800 Vpp, front and rear baffle voltage 1.8 V, SEP (Sweep Excitation Power) 15, mass-to-charge ratio (m / z) detection range 50–1500, cumulative scans 64 times during sampling. Sample preparation: prepared with chromatographically pure methanol to approximately 0.1 mg / mL. Figure 2 485.3719 is product 1 combined with a Na + The molecular ion peak.

[0104] The above results indicate that product 1 containing the compound shown in formula (a) was successfully synthesized in this embodiment.

[0105] Example 2

[0106]

[0107] Add a toluene solution of isooctadecenylsuccinic anhydride (30.08 g isooctadecenylsuccinic anhydride + 70.05 g toluene) to a three-necked flask, and install a mechanical stirrer, a nitrogen delivery tube, and a constant-pressure dropping funnel; prepare a toluene solution of 1-(2-aminoethyl)piperazine (11.75 g 1-(2-aminoethyl)piperazine + 23.52 g toluene), and pour the toluene solution of 1-(2-aminoethyl)piperazine into the constant-pressure dropping funnel; place the three-necked flask under... In a constant-temperature oil bath at 5°C, mechanical stirring was turned on and nitrogen was purged for 30 minutes. Nitrogen purging was then stopped, and a toluene solution of 1-(2-aminoethyl)piperazine was added dropwise to a three-necked flask. The addition was completed within 30 minutes. The constant-pressure dropping funnel was removed and replaced with a water separator containing toluene and a condenser. The oil bath was heated to 60°C and held at that temperature for 1.5 hours, then heated to 90°C and held at that temperature for 2 hours. Finally, the temperature was raised to 160°C until no more water condensed in the water separator. The resulting mixture was rotary evaporated to remove the toluene, yielding product 2 (a product containing the compound shown in formula (b) above).

[0108] Infrared spectroscopy of product 2 was performed, see... Figure 3 .

[0109] The infrared spectroscopy measurement conditions are as follows: Instrument model: Thermo Fisher Scientific NICOLET IS50, Instrument parameters: 16 scans, 4 cm⁻¹ resolution. -1 Scanning range 4000-400cm -1The above products are produced using the coating method.

[0110] Figure 3 Middle, 1771cm -1 and 1702cm -1 The peaks represent the symmetric and asymmetric stretching vibrations of the carbonyl C=O group of cyclic imides, at 1188 cm⁻¹. -1 The peak represents the CN stretching vibration of cyclic imides, at 977 cm⁻¹. -1 The peak corresponds to the out-of-plane bending vibration of the =CH trans configuration of the double bond. The above infrared spectroscopy results indicate that product 1 contains cyclic imide groups and double bonds.

[0111] Product 2 was analyzed by mass spectrometry, see [see details]. Figure 4 .

[0112] The mass spectrometry determination conditions are as follows:

[0113] Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), model Bruker SolariX XR, magnetic field strength 15T. Experimental conditions: injection rate 120 μL / h, electrospray ionization source, positive ion mode (ESI+), capillary voltage 4500 V, nebulizer 1 bar, drying gas flow rate 4.0 L / min, desiccator temperature 200 °C, TOF 0.6 ms, Q1 mass 150 u, RF 800 Vpp, front and rear baffle voltage 1.8 V, SEP (Sweep Excitation Power) 15, mass-to-charge ratio (m / z) detection range 50–1500, cumulative scans 64 times during sampling. Sample preparation: prepared with chromatographically pure methanol to approximately 0.1 mg / mL. Figure 4 In the middle, 462.4060 is product 2 combined with an H. + The molecular ion peak.

[0114] The above results indicate that product 2, containing the compound shown in formula (b), was successfully synthesized in this embodiment.

[0115] Example 3

[0116]

[0117] Add a solution of dodecenyl succinic anhydride in o-xylene (42.65 g dodecenyl succinic anhydride + 50 g o-xylene) to a three-necked flask, and install a mechanical stirrer, a nitrogen delivery tube, and a constant-pressure dropping funnel; prepare a solution of 1-(2-aminoethyl)piperazine in o-xylene (24.82 g 1-(2-aminoethyl)piperazine + 25.01 g o-xylene), and pour the 1-(2-aminoethyl)piperazine o-xylene solution into the constant-pressure dropping funnel; place the three-necked flask under... In a constant-temperature oil bath at 5°C, mechanical stirring was turned on and nitrogen was purged for 30 minutes. Nitrogen purging was then stopped, and a solution of 1-(2-aminoethyl)piperazine in o-xylene was added dropwise to a three-necked flask. The addition was completed in 42 minutes. The constant-pressure dropping funnel was removed and replaced with a water separator and condenser containing o-xylene. The oil bath was heated to 50°C and held at that temperature for 1 hour, then heated to 80°C and held at that temperature for 3 hours. Finally, the temperature was raised to 150°C until no more water condensed in the water separator. The o-xylene was removed by rotary evaporation of the reaction mixture to obtain product 3 (the product containing the compound with the structure shown in formula (c) above).

[0118] Test results for product 3:

[0119] 1773cm -1 and 1700cm -1 The peaks represent the symmetric and asymmetric stretching vibrations of the carbonyl C=O group of cyclic imides, at 1195 cm⁻¹. -1 The peak represents the CN stretching vibration of cyclic imides, at 979 cm⁻¹. -1 The peak represents the out-of-plane bending vibration of the =CH trans configuration of the double bond. The above infrared spectral results show that product 3 contains a cyclic imide group and a double bond, indicating that this embodiment successfully synthesized product 3 containing the structure shown in formula (c).

[0120] Test Example 1

[0121] Rust prevention performance test

[0122] T747A (alkenyl succinate rust inhibitor) was selected as comparative additive 1; mineral oil (150N) was selected as comparative base oil 1; polyalphaolefin (PAO6) was selected as comparative base oil 2; and diester (dioctyl sebacate) was selected as comparative base oil 3.

[0123] The rust-preventive effects of the above-prepared products 1, 2, and 3 and comparative additive 1 (T747A (alkenyl succinate rust inhibitor)) in lubricating oil were evaluated using the GB / T 11143A method.

[0124] The rust-preventive properties of the additives were evaluated by adding 8 g / kg of additives (products 1, 2, 3, and T747A mentioned above) to the base oil (pentaerythritol ester base oil). The test method, GB / T 11143A, specifies the method for determining the rust-preventive properties of inhibitory mineral oils in the presence of water. The specific method is as follows: 300 mL of sample is mixed with 30 mL of distilled water, and a cylindrical test steel rod is completely immersed in the mixture. The mixture is stirred at 60°C. The test period is 24 hours. After the test period, the rust marks and degree of rust on the test steel rod are observed. The rust-preventive performance test results are shown in Table 1.

[0125] Table 1

[0126]

[0127]

[0128] As can be seen from the results in Table 1, the addition of the imide compounds provided by the present invention has a significant effect on improving the corrosion of the specific ester base oils provided by the present invention, and its effect is better than the comparative additives mentioned above.

[0129] Test Example 2

[0130] Antioxidant performance evaluation

[0131] The antioxidant properties of products 1, 2, and 3 at 240℃ were evaluated using the SH / T 0719 method.

[0132] The antioxidant properties of the additives were evaluated by adding 5 g / kg of the additives (products 1, 2, and 3 prepared above) to ester base oils (pentaerythritol ester base oils). The test method SH / T 0719 specifies the method for determining the oxidation induction period of lubricating oils. The specific method is as follows: a small amount of sample is weighed into a sample dish and placed in the test cell of a PDSC instrument. The PDSC instrument test cell is heated to the specified temperature, and after equilibrium is reached, oxygen at a certain pressure is introduced. The PDSC instrument test cell is maintained at the specified temperature and oxygen pressure until the exothermic oxidation reaction occurs. The extrapolated inflection point time is measured and used as the oxidation induction period of the lubricating oil at the specified test temperature. The antioxidant test results are shown in Table 2.

[0133] Table 2

[0134]

[0135]

[0136] As can be seen from Table 2, the addition of the imide compounds provided by this invention has a good antioxidant effect on lubricating oils (especially for systems containing ester base oils (such as pentaerythritol ester base oils)).

[0137] Test Example 3

[0138] Lubrication performance is a fundamental property of lubricating oil. The lubrication performance of pentaerythritol ester base oil and compounded additives was evaluated using the GB / T 3142-2019 method (test conditions: 1200 rpm, 392 N, 75 ℃, 60 min). The average wear scar diameter results are shown in Table 3.

[0139] Table 3

[0140] oil sample Average wear scar diameter (mm) Pentaerythritol ester base oil 0.91 Pentaerythritol ester base oil + Product 2 0.91

[0141] As shown in Table 3, the addition of the imide compounds provided by this invention improves the rust prevention and / or antioxidant properties of the lubricating oil without reducing other basic properties. Product 1 obtained in Example 1 and Product 3 obtained in Example 3 also show similar results in terms of the basic properties of the lubricating oil.

[0142] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An imide compound, characterized in that, The imide compound has the structure shown in formula (I'): （I’） In formula (I'), X is NH or O; n is an integer from 0 to 6; L is a C1-C18 straight-chain or branched alkylene group or is absent; Q is... Or it may not exist, p is an integer from 0 to 18; R6, R7 and R8 are each independently selected from H, C1-C6 alkyl groups; wherein, the sum of the number of carbon atoms in L and the value of p is an integer not less than 8 and not greater than 20.

2. The imide compound according to claim 1, wherein, The imide compound is selected from at least one of the following compounds: (M1)、 (M2)ぁ (M3) 3. A method for preparing the imide compound of claim 1, characterized in that, The method includes: contacting the compound of formula (IV) with the compound of formula (V) to carry out an imidization reaction; (IV) (V) The compound shown in formula (IV) is selected from one of decenyl succinic anhydride, dodecenyl succinic anhydride, tetradecenyl succinic anhydride, pentadecenyl succinic anhydride, hexadecenyl succinic anhydride, octadecenyl succinic anhydride, and isooctadecenyl succinic anhydride. The compound shown in formula (V) is selected from one of 4-(2-aminoethyl)morpholine, N-(3-aminopropyl)morpholine, 4-morpholinebutamine, N-(3-aminopropyl)piperazine, 1-(2-aminoethyl)piperazine, and piperazine-1-methylamine.

4. The method according to claim 3, wherein, The compound shown in formula (IV) is dodecenyl succinic anhydride or isooctadecenyl succinic anhydride, and the compound shown in formula (V) is 4-(2-aminoethyl)morpholine or 1-(2-aminoethyl)piperazine.

5. The method according to claim 4, wherein, The compound shown in formula (IV) is isooctadecenylsuccinic anhydride, and the compound shown in formula (V) is 4-(2-aminoethyl)morpholine; or, The compound shown in formula (IV) is isooctadecenylsuccinic anhydride, and the compound shown in formula (V) is 1-(2-aminoethyl)piperazine; or, The compound shown in formula (IV) is dodecenylsuccinic anhydride, and the compound shown in formula (V) is 1-(2-aminoethyl)piperazine.

6. The method according to any one of claims 3-5, wherein, The imidization reaction is carried out at a temperature of 40-180℃ for a time of 0.5-20 hours. And / or, the molar ratio of the compound shown in formula (IV) to the compound shown in formula (V) is 1:(0.3-2); And / or, the imidization reaction is carried out under an inert atmosphere.

7. The method according to claim 6, wherein, The imidization reaction is carried out at a temperature of 50-160℃ for 1-15 hours. And / or, the molar ratio of the compound shown in formula (IV) to the compound shown in formula (V) is 1:(0.4-1.5).

8. The use of the imide compounds of claim 1 or 2 in rust inhibitors and / or antioxidants.

9. A composition having rust-preventive and / or antioxidant functions, characterized in that, The composition comprises: a base oil and an imide compound as described in claim 1 or 2, or a product prepared by the method according to any one of claims 3-7; The base oil is an ester base oil formed by the condensation of an alcohol and a carboxylic acid, wherein the alcohol is a polyol having the formula (VI), and the carboxylic acid is a saturated monocarboxylic acid with 4-20 carbon atoms. (WE), In equation (VI), R9, R 10 R 11 R 12 Each is independently selected from H, C1-C10 alkyl or hydroxyl groups, and R9, R 10 R 11 R 12 At least two of them are hydroxyl groups.

10. The composition according to claim 9, wherein, The composition contains 94-99.5 wt% base oil and 0.19-0.98 wt% imide compounds by weight.

11. The composition according to claim 9, wherein, The content of the imide compounds is 2-10g relative to 1kg of base oil.

12. The composition according to claim 9, wherein, The composition also contains antioxidants and / or extreme pressure anti-wear agents.

13. The composition according to claim 12, wherein, The antioxidant content is 0.1-4 wt% and the extreme pressure anti-wear agent content is 0.2-1.5 wt% based on the total weight of the composition.

14. The composition according to claim 12, wherein, The antioxidant is selected from at least one of aminothioesters, alkylated diphenylamine, N-phenyl-α-naphthylamine, and shielding phenols.

15. The composition according to claim 12, wherein, The extreme pressure anti-wear agent is selected from phosphate esters and / or phosphate ester amine salts.

16. The composition according to claim 9, wherein, The ester base oil is selected from at least one of neopentyl glycol ester, trimethylolpropane ester, and pentaerythritol ester.

17. The use of the imide compound of claim 1 or 2, or the product obtained by the method of any one of claims 3-7, in improving the rust prevention and / or antioxidant properties of ester base oils. in, The ester base oil is an ester base oil formed by the condensation of an alcohol and a carboxylic acid, wherein the alcohol is a polyol having the formula (VI), and the carboxylic acid is a saturated monocarboxylic acid with 4-20 carbon atoms. (WE), In equation (VI), R9, R 10 R 11 R 12 Each is independently selected from H, C1-C10 alkyl or hydroxyl groups, and R9, R 10 R 11 R 12 At least two of them are hydroxyl groups.

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