Lubricating oil composition for drones

Abstract

The present application provides a special lubricating oil composition for unmanned aerial vehicle, comprising aromatic amine type dispersant, detergent, kerosene, polyisobutylene, metal corrosion inhibitor and lubricating oil base oil, wherein the aromatic amine type dispersant comprises a polyamide compound having the following formula (1): wherein the definitions of each group are described in the specification. The special lubricating oil composition for unmanned aerial vehicle has very excellent cleaning and dispersing performance, and can greatly reduce the addition amount of antioxidant in the composition, and can meet the requirements of special lubricating oil products for unmanned aerial vehicle.

Description

Technical Field

[0001] This invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition for unmanned aerial vehicles (UAVs) with excellent detergency, dispersancy and antioxidant properties. Background Technology

[0002] With the continuous emergence of advanced technologies, the capabilities of unmanned aerial vehicle (UAV) systems are constantly improving, and UAVs are being widely used in various fields. Besides military applications, these include civilian uses such as agricultural plant protection, power line inspection, security and emergency response, aerial photography and surveying, forest fire prevention, and film and television aerial photography. In the future, the application potential of UAVs in agriculture and the military is enormous.

[0003] Oil-powered two-stroke drones have a large payload capacity, long endurance, and good wind resistance, occupying an important position in the drone market. Currently, there are many drone manufacturing companies in my country, but the two-stroke engine oils they use for drones basically adopt foreign compound agent technology.

[0004] Two-stroke engines for unmanned aerial vehicles (UAVs) operate at high temperatures and in complex environments, placing high demands on the detergency, dispersibility, and antioxidant properties of engine oils. Ordinary two-stroke gasoline engine oils cannot meet these requirements. To improve oil exhaust performance, even more stringent requirements have been placed on sulfate ash content in the oil, significantly limiting the use of metal detergents. Improving the detergency and dispersibility of oils while maintaining low ash content and low metal detergent concentration has become a new research hotspot. Summary of the Invention

[0005] This invention proposes a lubricating oil composition specifically for drones, which not only meets the increasingly stringent requirements for detergency and dispersion performance of today's higher-specification products, but also has excellent antioxidant properties, reducing the amount of antioxidants added or eliminating the need for antioxidants.

[0006] The UAV-specific lubricating oil composition of the present invention comprises an aromatic amine dispersant, a detergent, kerosene, polyisobutylene, a metal corrosion inhibitor, and a lubricating oil base oil, wherein the aromatic amine dispersant comprises a polyamide compound having the structure shown in formula (1):

[0007]

[0008] In this context, R1, R2, R3, and R4 may be the same or different from each other, and are independently selected from H, halogen, cyano, and alkyl groups having 1 to 10 carbon atoms; n1 represents the number of R1, n2 represents the number of R2, n3 represents the number of R3, and n4 represents the number of R4; n1, n2, n3, and n4 may be the same or different from each other, and are independently selected from 1, 2, 3, or 4; L is selected from single bonds or alkylene groups having 1 to 5 carbon atoms; PIB represents polyisobutylene.

[0009] According to the present invention, optionally, R1, R2, R3 and R4 are the same and are selected from H, halogen, cyano and alkyl with 1 to 10 carbon atoms; n1, n2 and n3 are the same and are selected from 1, 2, 3 or 4.

[0010] According to the present invention, optionally, R1, R2, R3 and R4 are each H and L is a single bond.

[0011] According to the present invention, optionally, the polyamide compound has the structure shown in formula (1-1):

[0012]

[0013] According to the present invention, the method for preparing the aromatic amine dispersant includes:

[0014] (A) The first reactant and the second reactant are brought into contact and reacted in the first solvent to obtain an intermediate product;

[0015] (B) The intermediate product and polyisobutylene maleic anhydride are brought into contact and reacted in a second solvent;

[0016] The first reactant has the structure shown in formula (2), and the second reactant has the structure shown in formula (3) or formula (4):

[0017]

[0018] R5 is selected from alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, and substituted or unsubstituted aryl groups having 6 to 15 carbon atoms. The substituents of the substituted aryl and substituted cycloalkyl groups are each independently selected from one or more of deuterium, halogens, and alkyl groups having 1 to 5 carbon atoms.

[0019] According to the present invention, optionally, the second reactant is selected from one of indocyanine anhydride, 6-methylindocyanine, and 6,8-dibromoindocyanine anhydride; or, the second reactant is selected from one of pentane p-aminobenzoate, ethyl 2-aminobenzoate, menthol o-aminobenzoate, and benzyl p-aminobenzoate; preferably, the second reactant is indocyanine anhydride.

[0020] According to the present invention, optionally, in step (A), the molar ratio of the first reactant to the second reactant is 1:(3-3.5), preferably 1:(3-3.2); the reaction conditions include: a reaction temperature of 80-100°C and a reaction time of 8-12 h; preferably, the reaction temperature is 85-95°C and the reaction time is 9-10 h.

[0021] According to the present invention, optionally, in step (B), the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3-3.5), preferably 1:(3-3.2); the reaction conditions include: a reaction temperature of 140-160°C and a reaction time of 4-8 h; preferably, the reaction temperature is 145-155°C and the reaction time is 5-7 h.

[0022] According to the present invention, optionally, the number average molecular weight of the polyisobutylene maleic anhydride is 800-2500, preferably 1000-2300; in step (A), the first solvent is toluene, benzene or xylene, preferably toluene; in step (B), the second solvent is a base oil, preferably 150SN or white oil, more preferably 150SN.

[0023] According to a preferred embodiment of the present invention, the reactions in steps (A) and (B) are carried out under the protection of an inert gas, which is nitrogen, helium or argon, preferably nitrogen.

[0024] According to the present invention, the aromatic amine dispersant comprises a polyamide compound with a centrosymmetric structure. The structure is centered on an N atom and contains multiple symmetrically positioned amide functional groups and multiple benzene rings. This compound exhibits high overall structural symmetry and a suitable molecular weight, making it more compatible with the polycyclic aromatic hydrocarbon structure of soot and resulting in better dispersibility. It not only effectively disperses soot but also inhibits viscosity growth in oils during use, thereby effectively solving the soot dispersion problem. The preparation method is simple and has high synthesis efficiency.

[0025] The aromatic amine dispersant of the present invention mainly comprises the polyamide compound shown in formula (1) above, for example, containing 50% or more by weight, 60% or more by weight, 70% or more by weight, 80% or more by weight, or 90% or more by weight. Preferably, the aromatic amine dispersant is composed of a polyamide compound. The polyamide compound has multiple electron-donating amide groups and contains numerous large conjugated systems, exhibiting good structural symmetry and excellent dispersing performance.

[0026] In this invention, when n1 is greater than 1, R1 is the same or different; when n2 is greater than 1, R2 is the same or different; when n3 is greater than 1, R3 is the same or different; when n4 is greater than 1, R4 is the same or different.

[0027] In this invention, a single bond refers to a situation where the portion represented by L does not contain any other atoms. For example, when L in chemical formula (1) is a single bond, N can be directly attached to the benzene ring.

[0028] In one embodiment of the present invention, R1, R2, R3, and R4 are identical and selected from H, halogen, cyano, and alkyl groups having 1 to 10 carbon atoms; n1, n2, and n3 are identical and selected from 1, 2, 3, or 4. Specifically, R1, R2, R3, and R4 can simultaneously be H, halogen, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, etc., but are not limited thereto. More preferably, the substitution positions of R1, R2, R3 and R4 on their respective benzene rings can be the same, that is, the connection positions of R1, R2, R3 and R4 on their respective benzene rings have the same relative positional relationship with the amide group. For example, R1, R2, R3 and R4 are respectively ortho to the amide group on their respective benzene rings, or R1, R2, R3 and R4 are respectively meta to the amide group on their respective benzene rings.

[0029] In one embodiment of the present invention, R1, R2, R3 and R4 are each H, and L is a single bond.

[0030] According to the present invention, the detergent can be selected from one or more of sulfonates, alkylphenol sulfonates and salicylates, preferably sulfonates, such as high-alkalinity calcium sulfonate, medium-alkalinity calcium sulfonate, low-alkalinity calcium sulfonate and high-alkalinity magnesium sulfonate, common grades include T106, T105, T101, Hitec 611, etc.

[0031] According to the present invention, the polyisobutylene can be selected from polyisobutylene with a number average molecular weight of 300 to 3000, preferably polyisobutylene with a molecular weight of 500 to 2000, and common grades include PIB-1000, PIB-1300, PIB-2000, etc.

[0032] According to the present invention, the kerosene may be selected from one or more of aviation kerosene, lamp kerosene and power kerosene, preferably kerosene with a distillation range of 50 to 400°C, such as aviation kerosene 1#, aviation kerosene 2#, aviation kerosene 3#, etc.

[0033] According to the present invention, the metal corrosion inhibitor may be selected from one or more of benzotriazole derivatives, thiazole derivatives, and thiadiazole derivatives, preferably benzotriazole derivatives, such as benzotriazole, benzothiazole, toluenetriazole, octyltriazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-5-hydrocarbon-substituted-1,3,4-thiadiazole, 2-dimercapto-5-dithio-1,3,4-thiadiazole, N,N-dihexylaminomethylenetriazole, and 2-mercaptobenzothiazole. Common commercial brands include T706, T551, Irgamet 39, Irgamet 42, etc.

[0034] According to the present invention, the base oil of the lubricating oil can be selected from mineral lubricating oils and / or synthetic lubricating oils. Common commercial brands of mineral lubricating oils include Group I 150SN, 600SN, 150BS, etc., and Group II 100N, 150N, etc. Common commercial brands of synthetic lubricating oils include PAO4, PAO6, PAO8, PAO10, etc. The viscosity index of the base oil of the lubricating oil is generally greater than 80, the mass fraction of saturated hydrocarbons is greater than 90%, and the mass fraction of sulfur is less than 0.03%.

[0035] According to the present invention, the aromatic amine dispersant accounts for 0.1% to 20% of the total mass of the lubricating oil composition, preferably 0.2% to 15%; the detergent accounts for 0.02% to 5% of the total mass of the lubricating oil composition, preferably 0.05% to 3%; the polyisobutylene accounts for 1% to 40% of the total mass of the lubricating oil composition, preferably 5% to 30%; the kerosene accounts for 1% to 35% of the total mass of the lubricating oil composition, preferably 5% to 30%; the metal corrosion inhibitor accounts for 0.01% to 5% of the total mass of the lubricating oil composition, preferably 0.02% to 3%; and the lubricating oil base oil accounts for 1% to 80% of the total mass of the lubricating oil composition, preferably 20% to 60%.

[0036] The method for preparing the drone-specific lubricant composition of the present invention includes the step of mixing the components in the aforementioned drone-specific lubricant composition.

[0037] The drone-specific lubricant composition of the present invention has excellent detergency, dispersancy and antioxidant properties, while significantly reducing the amount of antioxidant added in the composition, thus meeting the requirements of drone-specific lubricant products. Detailed Implementation

[0038] The present invention will be further illustrated by the following examples, but should not be construed as limiting in any way.

[0039] Unless otherwise specified, all raw materials used in the following embodiments are commercially available products.

[0040] The main raw materials used are as follows:

[0041] Polyisobutylene maleimide (PIB number-average molecular weight 1000), Yangzi Petrochemical;

[0042] Polyisobutylene maleic anhydride (PIB number-average molecular weight 1000), Yangzi Petrochemical;

[0043] Polyisobutylene (number average molecular weight 2000), Yangzi Petrochemical;

[0044] Ashless dispersant, T161, Yangzi Petrochemical;

[0045] Indocyanine anhydride, Ark Pharmaceuticals;

[0046] Tris(4-aminophenyl)amine, Shanghai Adamas Reagent Co., Ltd.;

[0047] Detergent, high alkalinity sulfonate, Wuxi Nanfang Additives Co., Ltd., T106;

[0048] Aviation kerosene #3, Yanshan Petrochemical;

[0049] Metal corrosion inhibitor, benzotriazole, Jinzhou Kangtai Lubricating Oil Additives Co., Ltd., T706;

[0050] 150N: Maoming Petrochemical Company;

[0051] Compared to phenolic ester antioxidants, T512 is produced by Beijing Xingpu Company.

[0052] Example 1

[0053] (A) Add 2.9g of tris(4-aminophenyl)amine and 4.89g of indomethacin anhydride to a 500ml reactor, then add 160ml of toluene, purge with nitrogen, turn on the reflux condenser, set the heating temperature to 90℃, and heat for 10 hours. Stop the reaction, distill off the toluene, and obtain intermediate product A1.

[0054] (B) Dissolve 33g of polyisobutylene maleic anhydride (number average molecular weight of 1000) in 100ml of 150SN, then add it to a reaction vessel containing intermediate product A1, purge with nitrogen, turn on the cooling water, heat to 150°C, heat for 6 hours, stop the reaction, and obtain the ashless dispersant F1 of this embodiment.

[0055] The final product and intermediate product A1 were separated and purified, and then characterized by infrared spectroscopy. The infrared characterization results show that the structure of the final product is as shown in equation (5), and the structure of the intermediate product A1 is as shown in equation (6).

[0056]

[0057] Example 2

[0058] The method of Example 1 was used, with the only difference being that in step (A), the heating temperature was set to 80°C and the heating time was 12 hours; in step (B), the heating temperature was set to 160°C and the heating time was 5 hours. Ashless dispersant F2 of this example was obtained.

[0059] Example 3

[0060] The method of Example 1 was used, with the only difference being that in step (A), the heating temperature was set to 100°C and the heating time was 8 hours; in step (B), the heating temperature was set to 140°C and the heating time was 8 hours. Ashless dispersant F3 of this example was obtained.

[0061] Comparative Example 1

[0062] The method of Example 1 was used, except that indomethacin anhydride was not added. Tris(4-aminophenyl)amine and polyisobutylene maleic anhydride were reacted at a molar ratio of 1:3. The reaction conditions were as follows: 33g of polyisobutylene maleic anhydride (number average molecular weight of 1000) was dissolved in 100ml of 150SN solution and added to the reaction vessel. Then, 2.9g of tris(4-aminophenyl)amine was added, nitrogen gas was introduced, cooling water was turned on, the temperature was raised to 150°C, and the heating time was 6 hours. The reaction was then stopped. Ashless dispersant DF1 of this comparative example was obtained.

[0063] Comparative Example 2

[0064] The method of Example 1 was used, except that tris(4-aminophenyl)amine was replaced with an equimolar amount of diaminodiphenylmethane. This yielded the ashless dispersant DF2 of this comparative example.

[0065] Comparative Example 3

[0066] The method of Example 1 was used, except that only polyisobutylene maleimide was used to synthesize the polyisobutylene maleimide-type ashless dispersant, wherein the number average molecular weight of the polyisobutylene maleimide was 1000. The ashless dispersant DF3 of this comparative example was obtained.

[0067] Examples 4-6 and Comparative Examples 4-8 of the lubricant composition for unmanned aerial vehicles (UAVs)

[0068] The formulations of the drone-specific lubricant compositions in Examples 4-6 and Comparative Examples 4-8 are shown in Table 1. Each component was added to a mixing container according to its composition, and the mixture was heated and stirred at 60°C for 2 hours to obtain the drone-specific lubricant compositions in Examples 4-6 and Comparative Examples 4-8. Aromatic amine dispersants F1, F2, and F3 were added to Examples 4-6, while comparative dispersants DF1, DF2, and DF-3, and commercially available T161 dispersant were added to Comparative Examples 4-7, respectively. Compared to Comparative Example 7, Comparative Example 8 additionally added T512 antioxidant.

[0069] The dispersion performance of the formulated drone-specific lubricant composition was evaluated using the sludge dispersion method. 2g of oil and 2g of sludge were mixed and ultrasonically dispersed. After aging in an oven at 110℃ for 2 hours, the sludge suspension was dropped onto filter paper. After 24 hours, the percentage ratio of the sludge diffusion ring diameter to the oil ring diameter was measured. A higher ratio indicates better dispersion performance of the drone-specific lubricant. The sludge dispersion results are shown in Table 1.

[0070] The detergency of the formulated UAV-specific lubricating oil composition was evaluated using an engine crankcase coking simulation test. 300 ml of the test sample was added to a coking plate simulator, heated to 120°C, and continuously splashed onto an aluminum plate at 330°C. After 300 minutes, the amount of coke formed on the aluminum plate was weighed to simulate piston deposits. Higher coke levels indicate poorer detergency of the test sample. The deposit results from the coking plate test are shown in Table 1.

[0071] The antioxidant properties of the formulated UAV-specific lubricant composition were evaluated using high-pressure differential scanning calorimetry (PDSC). The test temperature was 170℃ and the oxygen pressure was 3.5 MPa. A longer oxidation induction period indicates a stronger antioxidant capacity of the composition. The PDSC test results are shown in Table 1.

[0072] Table 1

[0073]

[0074] Comparing Examples 4-6 with Comparative Examples 4-7 in Table 1, it can be seen that the drone-specific lubricant composition of the present invention has excellent detergency, dispersancy, and antioxidant properties. Comparing Examples 4-6 with Comparative Examples 7-8, it can be seen that the drone-specific lubricant composition of the present invention has excellent antioxidant properties, reducing the amount of antioxidant required.

Claims

1. A lubricating oil composition for unmanned aerial vehicles (UAVs), comprising an aromatic amine dispersant, a detergent, kerosene, polyisobutylene, a metal corrosion inhibitor, and a lubricating oil base oil, wherein the aromatic amine dispersant comprises a polyamide compound having the structure shown in formula (1): Equation (1) PIB stands for polyisobutylene group; The detergent is selected from one or more of sulfonates, sulfidated alkylphenol salts, and salicylates; the polyisobutylene is selected from polyisobutylene with a number average molecular weight of 300-3000; the kerosene is selected from one or more of aviation kerosene, lamp kerosene, and power kerosene; the metal corrosion inhibitor is selected from one or more of benzotriazole derivatives, thiazole derivatives, and thiadiazole derivatives; and the lubricating oil base oil is selected from mineral lubricating oils and / or synthetic lubricating oils.

2. The lubricating oil composition according to claim 1, characterized in that, The preparation method of the aromatic amine dispersant includes: (A) The first reactant and the second reactant are brought into contact and reacted in the first solvent to obtain an intermediate product; (B) The intermediate product and polyisobutylene maleic anhydride are brought into contact and reacted in a second solvent; The first reactant is selected from tris(4-aminophenyl)amine, and the second reactant is selected from indomethacin anhydride.

3. The lubricating oil composition according to claim 2, characterized in that, In step (A), the molar ratio of the first reactant to the second reactant is 1:(3~3.5); The reaction conditions include: a reaction temperature of 80-100℃ and a reaction time of 8-12h.

4. The lubricating oil composition according to claim 2, characterized in that, In step (A), the molar ratio of the first reactant to the second reactant is 1:(3~3.2); The reaction conditions include: a reaction temperature of 85-95℃ and a reaction time of 9-10h.

5. The lubricating oil composition according to claim 2, characterized in that, In step (B), the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3~3.5). The reaction conditions include: a reaction temperature of 140-160℃ and a reaction time of 4-8h.

6. The lubricating oil composition according to claim 2, characterized in that, In step (B), the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3~3.2). The reaction conditions include: a reaction temperature of 145-155℃ and a reaction time of 5-7 hours.

7. The lubricating oil composition according to claim 2, characterized in that, The number-average molecular weight of the polyisobutylene maleic anhydride is 800-2500; In step (A), the first solvent is toluene, benzene, or xylene; In step (B), the second solvent is the base oil.

8. The lubricating oil composition according to claim 2, characterized in that, The number-average molecular weight of the polyisobutylene maleic anhydride is 1000~2300; In step (A), the first solvent is toluene; In step (B), the second solvent is 150SN or white oil.

9. The lubricating oil composition according to any one of claims 1 to 8, characterized in that, The aromatic amine dispersant accounts for 0.1% to 20% of the total mass of the lubricating oil composition; the detergent accounts for 0.02% to 5% of the total mass of the lubricating oil composition; the polyisobutylene accounts for 1% to 40% of the total mass of the lubricating oil composition; the kerosene accounts for 1% to 35% of the total mass of the lubricating oil composition; the metal corrosion inhibitor accounts for 0.01% to 5% of the total mass of the lubricating oil composition; and the base oil accounts for 1% to 80% of the total mass of the lubricating oil composition.

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