Composite additive for reduction gearbox oil of pure electric vehicle and preparation method of composite additive

Abstract

The invention belongs to the technical field of lubricating oil additives, and particularly relates to a pure electric automobile reduction gearbox oil composite additive and a preparation method thereof.The pure electric automobile reduction gearbox oil composite additive comprises, by mass, 8-12% of an antioxidant, 10-15% of a friction index improver, 0.1-0.5% of an anti-foaming agent, 70-78% of an anti-wear agent and 2-5% of an anti-rust agent; the antioxidant is amino siloxane modified phenyl phenothiazine, and the anti-foaming agent is perfluorocyclobutyl aryl ether silicone oil. In amino siloxane modified phenyl phenothiazine, a benzene ring is connected to N of phenothiazine, polarity of phenothiazine is reduced, a siloxane chain segment can isolate a polar sulfoxide product generated after oxidation of phenyl phenothiazine, a flexible structure of a siloxane chain can wrap phenothiazine active groups, side reaction between phenothiazine active groups and metal ions is reduced, and the service life of phenothiazine is prolonged. In addition, amino groups in the amino siloxane modified phenyl phenothiazine can neutralize acidic oxidation products, metal saponification reaction is reduced, and generation of the oil sludge is further reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of lubricating oil additives, and in particular relates to a composite additive for a reduction gearbox oil of a pure electric vehicle and a preparation method thereof. Background Art

[0002] Pure electric vehicles (BEVs) rely solely on power batteries and drive motors for power. They primarily consist of a chassis, body, power batteries, drive motors, electrical equipment, and various auxiliary systems. Achieving zero emissions while driving is the ultimate goal of new energy vehicle development.

[0003] As motors develop towards high power and high torque, the electric drive systems of pure electric vehicles generate a lot of heat during operation. Especially for oil-cooled motor reducers, the operating conditions are more demanding, the oil operating load increases, and higher requirements are placed on the oil's antioxidant and anti-foaming properties.

[0004] Phenothiazine, as an antioxidant added to gearbox oil, is effective in inhibiting the viscosity growth and acid value growth of gearbox oil and prolonging oxidation induction. However, phenothiazine easily causes sludge in gearbox oil, especially when used as an antioxidant in hydrogenated base oil. The saturated hydrocarbon content of hydrogenated base oil is higher, resulting in more serious sludge production. Summary of the Invention

[0005] The purpose of the present invention is to provide a composite additive for pure electric vehicle reduction gearbox oil and a preparation method thereof to solve the above technical problems.

[0006] In order to achieve the above technical objectives, the technical solution of the present invention is: A composite additive for a reduction gearbox oil of a pure electric vehicle, comprising the following components by mass percentage: 8-12% of an antioxidant, 10-15% of a friction index improver, 0.1-0.5% of an anti-foaming agent, 70-78% of an anti-wear agent, and 2-5% of a rust inhibitor; The antioxidant is aminosiloxane-modified phenylphenothiazine, and the anti-foaming agent is perfluorocyclobutyl aryl ether silicone oil.

[0007] As a further improvement, the anti-wear agent includes thiophosphite amine salt, phosphate, phosphonate and thiophosphate in a mass ratio of 4:6:5:1; the rust inhibitor is benzotriazole, and the friction index improver is phosphate or sulfurized fatty acid amine salt.

[0008] As a further improvement, the following components are included in percentage by mass: 10% antioxidant, 12% friction index improver, 0.3% anti-foaming agent, 74.7% anti-wear agent and 3% rust inhibitor.

[0009] The present invention also provides a method for preparing a composite additive for a reduction gearbox oil of a pure electric vehicle, comprising the following steps: S1. Under nitrogen protection, toluene, bromophenylphenothiazine and 3-aminopropyltriethoxysilane are mixed, and a catalyst trisdibenzylideneacetone dipalladium and 4,5-bisdiphenylphosphine-9,9-dimethylxanthene are added thereto, and potassium tert-butoxide is added at the same time. The mixture is reacted at 80-85° C. for 4-6 hours. After the reaction is completed, the mixture is cooled and filtered. The filter residue is washed with ethyl acetate, and then distilled under reduced pressure at 6.7 kPa and 30° C., and then separated and purified using a basic alumina chromatography column to obtain aminosiloxane-modified phenylphenothiazine; S2, using dimethyldimethoxysilane and 1-bromo-4-((1,2,2-trifluorovinyl)oxy)benzene as raw materials, preparing aryl trifluorovinyl ether silane through Grignard reaction; Perfluorocyclobutyl aryl ether silane was prepared by thermal cyclization reaction of aryl trifluorovinyl ether silane under argon protection. Under argon protection, using anhydrous acetic acid as solvent, perfluorocyclobutyl aryl ether silane and dimethyldiethoxysilane as raw materials, the reaction was carried out at 90-95°C for 24 hours. After the reaction, the mixture was cooled to room temperature, the acetic acid was removed by rotary evaporation, and perfluorocyclobutyl aryl ether silicone oil was obtained by vacuum distillation. S3. Add aminosiloxane-modified phenylphenothiazine, perfluorocyclobutyl aryl ether silicone oil, friction index improver, anti-wear agent and rust inhibitor into the reactor in sequence, stir at a speed of 300-400 r / min for 40-60 min, and let it stand for 40-60 min after mixing to obtain a composite additive for pure electric vehicle gearbox oil.

[0010] As a further improvement, in step S1, the preparation method of the brominated phenylphenothiazine is as follows: dissolving phenylphenothiazine in tetrahydrofuran, adding N-bromosuccinamide thereto in an ice-water bath at 5°C, controlling the reaction temperature to 3-5°C, reacting for 6-8 hours, then pouring the reaction solution into water and stirring to precipitate a solid, filtering and washing the filter cake with distilled water, and drying the filter cake to obtain brominated phenylphenothiazine.

[0011] As a further improvement, the preparation method of the phenylphenothiazine is as follows: phenothiazine, copper powder, potassium carbonate and iodobenzene are added to chlorobenzene, heated to 190-195°C for reaction for 10 hours, cooled to room temperature after the reaction is completed, and then heated to 195°C for distillation to remove the remaining iodobenzene, cooled to room temperature again, and then anhydrous ethanol is added, heated to 70°C and stirred for 10 minutes, and then immediately filtered, the filtrate is collected for room temperature crystallization, and the precipitate is filtered and dried to obtain phenylphenothiazine.

[0012] As a further improvement, in step S1, the molar ratio of bromophenylphenothiazine, 3-aminopropyltriethoxysilane, trisdibenzylideneacetone dipalladium, 4,5-bisdiphenylphosphine-9,9-dimethylxanthene and potassium tert-butoxide is 1:3:0.025:0.03~0.04:1.4, and the eluent in the chromatography column separation and purification process is a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 1:1.

[0013] As a further improvement, in step S2, the molar ratio of the perfluorocyclobutyl aryl ether silane to dimethyldiethoxysilane is 1:1.

[0014] As a further improvement, the molar ratio of the phenylphenothiazine to the N-bromosuccinamide is 3:2.5-2.8.

[0015] As a further improvement, the molar ratio of phenothiazine, iodobenzene, copper powder and potassium carbonate is 1:2.1:0.73~0.8:3.23~3.26.

[0016] Due to the adoption of the above technical solution, the present invention has the following beneficial effects: The present invention provides a composite additive for a pure electric vehicle gearbox oil and a preparation method thereof. In aminosilicone-modified phenylphenothiazine, a benzene ring is connected to the nitrogen of phenothiazine to reduce the polarity of phenothiazine. The siloxane chain segment can isolate the polar sulfoxide product produced after oxidation of phenylphenothiazine. The flexible structure of the siloxane chain can wrap the active group of phenothiazine, reducing its side reaction with metal ions and reducing the generation of oil sludge. In addition, the amino group in the aminosilicone-modified phenylphenothiazine can neutralize acidic oxidation products, reduce metal saponification reactions, and further reduce the generation of oil sludge.

[0017] Aminosiloxane-modified phenylphenothiazine is an antioxidant containing multiple secondary amine groups, which can scavenge free radicals generated by the base oil. At the same time, the sulfur in aminosilane-modified phenylphenothiazine acts as a peroxide decomposer, which can scavenge peroxides generated by oxidation of the base oil. There is no need to compound free radical scavengers and peroxide decomposers, and the antioxidant effect is better.

[0018] In the present invention, perfluorocyclobutyl aryl ether silicone oil is used as an anti-foaming agent. The presence of the aromatic group improves the mechanical properties and thermal stability of the silicone oil, allowing it to always remain in a droplet state in the base oil, preventing the high-speed gear from stirring and destroying its droplet state, thereby losing the defoaming effect.

[0019] The presence of the perfluorocyclobutyl structure can improve the electrical insulation of silicone oil and meet the requirements of pure electric vehicles. At the same time, the close arrangement of fluorine atoms in the perfluorocyclobutyl group can further reduce the surface tension of silicone oil and improve the defoaming effect.

[0020] In the present invention, thiophosphite amine salt, phosphate, phosphonate and thiophosphate are compounded as the anti-wear agent, which has better anti-wear effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The results are as follows: the antioxidant performance of the composite additives prepared in Example 1 and Comparative Examples 1-3 on reduction gearbox oil; Figure 2 The results are the test results of the composite additives of Example 1 and Comparative Examples 1-3 on the sludge generation performance of the reduction gearbox oil; Figure 3 These are the test results of the composite additives of Example 1 and Comparative Examples 1-3 on the insulation performance of reduction gearbox oil. DETAILED DESCRIPTION

[0022] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are conventional products that can be purchased commercially.

[0023] In the present invention, phenothiazine, iodobenzene, chlorobenzene, N-bromosuccinamide, trisdibenzylideneacetone dipalladium, and dimethyldimethoxysilane were all purchased from Adamas-beta; potassium carbonate, copper powder, and tetrahydrofuran were purchased from General Reagent; 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene was purchased from Zhejiang Metallurgical Research Institute; and 1-bromo-4-((1,2,2-trifluorovinyl)oxy)benzene was purchased from Hubei Rishengchang New Material Technology Co., Ltd.

[0024] Example 1 A composite additive for a pure electric vehicle gearbox oil comprises the following components, in percentage by mass: 10% of an antioxidant aminosiloxane-modified phenylphenothiazine, 12% of a friction index improver sulfurized fatty acid amine salt, 0.3% of an anti-foaming agent perfluorocyclobutyl aromatic ether silicone oil, 74.7% of an anti-wear agent, and 3% of a rust inhibitor benzotriazole, wherein the anti-wear agent comprises thiophosphite amine salt, phosphate ester, phosphonate ester, and thiophosphate ester, and the mass ratio of thiophosphite amine salt, phosphate ester, phosphonate ester, and thiophosphate ester is 4:6:5:1.

[0025] This embodiment also provides a method for preparing the above-mentioned composite additive for pure electric vehicle reduction gearbox oil, which specifically includes the following steps: S1, take 1 mol of phenothiazine, 0.73 mol of copper powder, 3.23 mol of potassium carbonate and 2.1 mol of iodobenzene, add it to 300 mL of chlorobenzene, heat it to 190 ° C and react for 10 hours, cool it to room temperature after the reaction is completed, then heat it to 195 ° C and distill it to remove the remaining iodobenzene, cool it to room temperature again, add 300 mL of anhydrous ethanol, heat it to 70 ° C and stir for 10 minutes, then filter it immediately, collect the filtrate and crystallize it at room temperature, filter and collect the precipitate and dry it at 60 ° C to obtain phenylphenothiazine; The specific equation is as follows: ; S2, 3 mol of phenylphenothiazine was dissolved in 20 mL of tetrahydrofuran, 2.5 mol of N-bromosuccinamide was added thereto under a 5°C ice-water bath, the reaction temperature was controlled to 5°C, and the reaction was carried out for 6 h. The reaction solution was then poured into water and stirred to precipitate a solid. After suction filtration, the filter cake was washed with distilled water, and the filter cake was dried at 80°C to obtain bromophenylphenothiazine; The specific equation is as follows: ; S3. Under nitrogen protection, 6 mL of toluene, 1 mol of bromophenylphenothiazine and 3 mol of 3-aminopropyltriethoxysilane were mixed, and 0.025 mol of trisdibenzylideneacetone dipalladium and 0.03 mol of 4,5-bisdiphenylphosphine-9,9-dimethylxanthene were added thereto. At the same time, 1.4 mol of potassium tert-butoxide was added, and the mixture was reacted at 80° C. for 6 h. After the reaction was completed, the mixture was cooled and filtered. The obtained filter residue was washed three times with ethyl acetate, and then distilled under reduced pressure at 6.7 kPa and 30° C., and then separated and purified by alkaline alumina chromatography column to obtain aminosiloxane-modified phenylphenothiazine. The chromatography column separation and purification used a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 1:1 as the eluent; The specific equation is as follows: , Among them, R1 is ; S4. Under argon protection, 0.8 mol of magnesium powder, 0.49 mol of dimethyldimethoxysilane, and 180 mL of tetrahydrofuran were mixed, and then a mixed solution of 0.16 mol of 1-bromo-4-((1,2,2-trifluorovinyl)oxy)benzene and 20 mL of tetrahydrofuran was slowly added thereto. The mixture was stirred and reacted at room temperature for 24 h. After the reaction was completed, 120 mL of toluene was added. After filtering, the mixture was distilled under reduced pressure at 75°C to obtain aryl trifluorovinyl ether silane. The specific equation is as follows: ; S5. Under argon protection, 0.04 mol of aryl trifluorovinyl ether silane was stirred and reacted at 175° C. for 9 h. After the reaction was completed, unreacted raw materials were removed by reduced pressure distillation at 80° C. to obtain perfluorocyclobutyl aryl ether silane; The specific equation is as follows: ; S6. Under argon protection, 1 mol of anhydrous acetic acid was heated to 90° C., and 0.01 mol of perfluorocyclobutyl aryl ether silane and 0.01 mol of dimethyldiethoxysilane were slowly added dropwise thereto. The reaction was refluxed for 24 h. After the reaction was completed, the reaction was cooled to room temperature, the acetic acid was removed by rotary evaporation, and the volatile components were removed by reduced pressure distillation at 10 kPa and 60° C. to obtain perfluorocyclobutyl aryl ether silicone oil; The specific equation is as follows: ; S7. Add 10g of aminosiloxane-modified phenylphenothiazine, 12g of friction index improver sulfurized fatty acid amine salt, 0.3g of perfluorocyclobutyl aromatic ether silicone oil, 18.68g of thiophosphite amine salt, 28.01g of phosphate ester, 23.34g of phosphonate ester, 4.67g of thiophosphate and 3g of rust inhibitor benzotriazole into the reactor in sequence, stir at a speed of 300r / min for 60min, let it stand for 60min after mixing, and obtain a composite additive for pure electric vehicle gearbox oil.

[0026] Example 2 A composite additive for a pure electric vehicle gearbox oil comprises the following components in percentage by mass: 8% of an antioxidant aminosiloxane-modified phenylphenothiazine, 15% of a friction index improver phosphate, 0.1% of an anti-foaming agent perfluorocyclobutyl aromatic ether silicone oil, 74.9% of an anti-wear agent and 2% of a rust inhibitor benzotriazole, wherein the anti-wear agent comprises thiophosphate amine salt, phosphate, phosphonate and thiophosphate, and the mass ratio of thiophosphate amine salt, phosphate, phosphonate and thiophosphate is 4:6:5:1.

[0027] This embodiment also provides a method for preparing the above-mentioned composite additive for pure electric vehicle reduction gearbox oil, which specifically includes the following steps: S1, take 1 mol of phenothiazine, 0.8 mol of copper powder, 3.26 mol of potassium carbonate and 2.1 mol of iodobenzene, add it to 300 mL of chlorobenzene, heat it to 195 ° C and react for 10 hours, cool it to room temperature after the reaction is completed, then heat it to 195 ° C again and distill it to remove the remaining iodobenzene, cool it to room temperature again and add 300 mL of anhydrous ethanol, heat it to 70 ° C and stir for 10 minutes, then filter it immediately, collect the filtrate and crystallize it at room temperature, filter and collect the precipitate and dry it at 60 ° C to obtain phenylphenothiazine; S2, 3 mol of phenylphenothiazine was dissolved in 20 mL of tetrahydrofuran, 2.8 mol of N-bromosuccinamide was added thereto under a 5°C ice-water bath, the reaction temperature was controlled to 3°C, and the reaction was carried out for 8 h. The reaction solution was then poured into water and stirred to precipitate a solid. After suction filtration, the filter cake was washed with distilled water, and the filter cake was dried at 80°C to obtain bromophenylphenothiazine; S3. Under nitrogen protection, 6 mL of toluene, 1 mol of bromophenylphenothiazine and 3 mol of 3-aminopropyltriethoxysilane were mixed, and 0.025 mol of trisdibenzylideneacetone dipalladium and 0.04 mol of 4,5-bisdiphenylphosphine-9,9-dimethylxanthene were added thereto as catalysts, and 1.4 mol of potassium tert-butoxide were added at the same time. The mixture was reacted at 80° C. for 6 h. After the reaction was completed, the mixture was cooled and filtered. The obtained filter residue was washed three times with ethyl acetate, and then distilled under reduced pressure at 6.7 kPa and 30° C., and then separated and purified by alkaline alumina chromatography column to obtain aminosiloxane-modified phenylphenothiazine. The chromatography column separation and purification used a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 1:1 as the eluent; S4. Under argon protection, 0.8 mol of magnesium powder, 0.49 mol of dimethyldimethoxysilane, and 180 mL of tetrahydrofuran were mixed, and then a mixed solution of 0.16 mol of 1-bromo-4-((1,2,2-trifluorovinyl)oxy)benzene and 20 mL of tetrahydrofuran was slowly added thereto. The mixture was stirred and reacted at room temperature for 24 h. After the reaction was completed, 120 mL of toluene was added. After filtering, the mixture was distilled under reduced pressure at 75°C to obtain aryl trifluorovinyl ether silane. S5. Under argon protection, 0.04 mol of aryl trifluorovinyl ether silane was stirred and reacted at 175° C. for 9 h. After the reaction was completed, unreacted raw materials were removed by reduced pressure distillation at 80° C. to obtain perfluorocyclobutyl aryl ether silane; S6. Under argon protection, 1 mol of anhydrous acetic acid was heated to 95° C., and 0.01 mol of perfluorocyclobutyl aryl ether silane and 0.01 mol of dimethyldiethoxysilane were slowly added dropwise thereto. The reaction was refluxed for 24 h. After the reaction was completed, the reaction was cooled to room temperature, the acetic acid was removed by rotary evaporation, and the volatile components were removed by reduced pressure distillation at 10 kPa and 60° C. to obtain perfluorocyclobutyl aryl ether silicone oil; S7. Add 8g of aminosiloxane-modified phenylphenothiazine, 15g of friction index improver phosphate, 0.1g of perfluorocyclobutyl aromatic ether silicone oil, 18.73g of thiophosphite amine salt, 28.09g of phosphate, 23.40g of phosphonate, 4.68g of thiophosphate and 2g of rust inhibitor benzotriazole into the reactor in sequence, stir at a speed of 400r / min for 40min, let it stand for 40min after mixing, and obtain a composite additive for pure electric vehicle gearbox oil.

[0028] Example 3 A composite additive for a pure electric vehicle gearbox oil comprises the following components in percentage by mass: 12% of an antioxidant aminosiloxane-modified phenylphenothiazine, 10% of a friction index improver sulfurized fatty acid amine salt, 0.5% of an anti-foaming agent perfluorocyclobutyl aromatic ether silicone oil, 72.5% of an anti-wear agent and 5% of a rust inhibitor benzotriazole, wherein the anti-wear agent comprises thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester, and the mass ratio of thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester is 4:6:5:1.

[0029] This embodiment also provides a method for preparing the above-mentioned composite additive for pure electric vehicle reduction gearbox oil, which specifically includes the following steps: S1, take 1 mol of phenothiazine, 0.76 mol of copper powder, 3.25 mol of potassium carbonate and 2.1 mol of iodobenzene, add it to 300 mL of chlorobenzene, heat it to 193 ° C and react for 10 hours, cool it to room temperature after the reaction is completed, then heat it again to 195 ° C and distill it to remove the remaining iodobenzene, cool it to room temperature again and add 300 mL of anhydrous ethanol, heat it to 70 ° C and stir for 10 minutes, then filter it immediately, collect the filtrate and crystallize it at room temperature, filter and collect the precipitate and dry it at 60 ° C to obtain phenylphenothiazine; S2, 3 mol of phenylphenothiazine was dissolved in 20 mL of tetrahydrofuran, 2.7 mol of N-bromosuccinamide was added thereto under a 5°C ice-water bath, the reaction temperature was controlled to 4°C, and the reaction was carried out for 7 h. The reaction solution was then poured into water and stirred to precipitate a solid. After suction filtration, the filter cake was washed with distilled water, and the filter cake was dried at 80°C to obtain bromophenylphenothiazine; S3. Under nitrogen protection, 6 mL of toluene, 1 mol of bromophenylphenothiazine and 3 mol of 3-aminopropyltriethoxysilane were mixed, and 0.025 mol of trisdibenzylideneacetone dipalladium and 0.035 mol of 4,5-bisdiphenylphosphine-9,9-dimethylxanthene were added as catalysts, and 1.4 mol of potassium tert-butoxide were added at the same time. The mixture was reacted at 83° C. for 5 h. After the reaction was completed, the mixture was cooled and filtered. The obtained filter residue was washed three times with ethyl acetate, and then distilled under reduced pressure at 6.7 kPa and 30° C., and then separated and purified by alkaline alumina chromatography column to obtain aminosiloxane-modified phenylphenothiazine. The chromatography column separation and purification used a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 1:1 as the eluent; S4. Under argon protection, 0.8 mol of magnesium powder, 0.49 mol of dimethyldimethoxysilane, and 180 mL of tetrahydrofuran were mixed, and then a mixed solution of 0.16 mol of 1-bromo-4-((1,2,2-trifluorovinyl)oxy)benzene and 20 mL of tetrahydrofuran was slowly added thereto. The mixture was stirred and reacted at room temperature for 24 h. After the reaction was completed, 120 mL of toluene was added. After filtering, the mixture was distilled under reduced pressure at 75°C to obtain aryl trifluorovinyl ether silane. S5. Under argon protection, 0.04 mol of aryl trifluorovinyl ether silane was stirred and reacted at 175° C. for 9 h. After the reaction was completed, unreacted raw materials were removed by reduced pressure distillation at 80° C. to obtain perfluorocyclobutyl aryl ether silane; S6. Under argon protection, 1 mol of anhydrous acetic acid was heated to 93° C., and 0.01 mol of perfluorocyclobutyl aryl ether silane and 0.01 mol of dimethyldiethoxysilane were slowly added dropwise thereto. The reaction was refluxed for 24 h. After the reaction was completed, the reaction was cooled to room temperature, and the acetic acid was removed by rotary evaporation. The volatile components were removed by reduced pressure distillation at 10 kPa and 60° C. to obtain perfluorocyclobutyl aryl ether silicone oil; S7. Add 12g of aminosiloxane-modified phenylphenothiazine, 10g of friction index improver sulfurized fatty acid amine salt, 0.5g of perfluorocyclobutyl aromatic ether silicone oil, 18.12g of thiophosphite amine salt, 27.19g of phosphate ester, 22.66g of phosphonate ester, 4.53g of thiophosphate and 5g of rust inhibitor benzotriazole into the reactor in sequence, stir at a speed of 350r / min for 50min, let it stand for 50min after mixing, and obtain a composite additive for pure electric vehicle gearbox oil.

[0030] Example 4 A composite additive for a pure electric vehicle gearbox oil comprises the following components in percentage by mass: 12% of an antioxidant aminosilicone-modified phenylphenothiazine, 12.5% ​​of a friction index improver sulfurized fatty acid amine salt, 0.5% of an anti-foaming agent perfluorocyclobutyl aromatic ether silicone oil, 70% of an anti-wear agent and 5% of a rust inhibitor benzotriazole, wherein the anti-wear agent comprises thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester, and the mass ratio of thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester is 4:6:5:1.

[0031] This embodiment also provides a method for preparing the above-mentioned composite additive for pure electric vehicle reduction gearbox oil, which specifically includes the following steps: S1, take 1 mol of phenothiazine, 0.73 mol of copper powder, 3.23 mol of potassium carbonate and 2.1 mol of iodobenzene, add it to 300 mL of chlorobenzene, heat it to 190 ° C and react for 10 hours, cool it to room temperature after the reaction is completed, then heat it to 195 ° C and distill it to remove the remaining iodobenzene, cool it to room temperature again, add 300 mL of anhydrous ethanol, heat it to 70 ° C and stir for 10 minutes, then filter it immediately, collect the filtrate and crystallize it at room temperature, filter and collect the precipitate and dry it at 60 ° C to obtain phenylphenothiazine; S2, 3 mol of phenylphenothiazine was dissolved in 20 mL of tetrahydrofuran, 2.5 mol of N-bromosuccinamide was added thereto under a 5°C ice-water bath, the reaction temperature was controlled to 5°C, and the reaction was carried out for 6 h. The reaction solution was then poured into water and stirred to precipitate a solid. After suction filtration, the filter cake was washed with distilled water, and the filter cake was dried at 80°C to obtain bromophenylphenothiazine; S3. Under nitrogen protection, 6 mL of toluene, 1 mol of bromophenylphenothiazine and 3 mol of 3-aminopropyltriethoxysilane were mixed, and 0.025 mol of trisdibenzylideneacetone dipalladium and 0.03 mol of 4,5-bisdiphenylphosphine-9,9-dimethylxanthene were added thereto as catalysts, and 1.4 mol of potassium tert-butoxide were added at the same time. The mixture was reacted at 80° C. for 6 h. After the reaction was completed, the mixture was cooled and filtered. The obtained filter residue was washed three times with ethyl acetate, and then distilled under reduced pressure at 6.7 kPa and 30° C., and then separated and purified using an alkaline alumina chromatography column to obtain aminosiloxane-modified phenylphenothiazine. The chromatography column separation and purification used a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 1:1 as the eluent; S4. Under argon protection, 0.8 mol of magnesium powder, 0.49 mol of dimethyldimethoxysilane, and 180 mL of tetrahydrofuran were mixed, and then a mixed solution of 0.16 mol of 1-bromo-4-((1,2,2-trifluorovinyl)oxy)benzene and 20 mL of tetrahydrofuran was slowly added thereto. The mixture was stirred and reacted at room temperature for 24 h. After the reaction was completed, 120 mL of toluene was added. After filtering, the mixture was distilled under reduced pressure at 75°C to obtain aryl trifluorovinyl ether silane. S5. Under argon protection, 0.04 mol of aryl trifluorovinyl ether silane was stirred and reacted at 175° C. for 9 h. After the reaction was completed, unreacted raw materials were removed by reduced pressure distillation at 80° C. to obtain perfluorocyclobutyl aryl ether silane; S6. Under argon protection, 1 mol of anhydrous acetic acid was heated to 90° C., and 0.01 mol of perfluorocyclobutyl aryl ether silane and 0.01 mol of dimethyldiethoxysilane were slowly added dropwise thereto. The reaction was refluxed for 24 h. After the reaction was completed, the reaction was cooled to room temperature, the acetic acid was removed by rotary evaporation, and the volatile components were removed by reduced pressure distillation at 10 kPa and 60° C. to obtain perfluorocyclobutyl aryl ether silicone oil; S7. Add 12g of aminosiloxane-modified phenylphenothiazine, 12.5g of friction index improver sulfurized fatty acid amine salt, 0.5g of perfluorocyclobutyl aromatic ether silicone oil, 17.50g of thiophosphite amine salt, 26.25g of phosphate ester, 21.87g of phosphonate ester, 4.38g of thiophosphate and 5g of rust inhibitor benzotriazole into the reactor in sequence, stir at a speed of 300r / min for 60min, let it stand for 60min after mixing, and obtain a composite additive for pure electric vehicle gearbox oil.

[0032] Example 5 A composite additive for a pure electric vehicle gearbox oil comprises the following components in percentage by mass: 8% of an antioxidant aminosilicone-modified phenylphenothiazine, 11.5% of a friction index improver sulfurized fatty acid amine salt, 0.5% of an anti-foaming agent perfluorocyclobutyl aromatic ether silicone oil, 78% of an anti-wear agent and 2% of a rust inhibitor benzotriazole, wherein the anti-wear agent comprises thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester, and the mass ratio of thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester is 4:6:5:1.

[0033] The preparation method of the composite additive for the reduction gearbox oil of pure electric vehicles in this embodiment is the same as that in Example 1.

[0034] Comparative Example 1 This comparative example provides a composite additive for a pure electric vehicle gearbox oil, which includes the following components in percentage by mass: 10% of an antioxidant phenylphenothiazine, 12% of a friction index improver sulfurized fatty acid amine salt, 0.3% of an anti-foaming agent perfluorocyclobutyl aromatic ether silicone oil, 74.7% of an anti-wear agent and 3% of a rust inhibitor benzotriazole, wherein the anti-wear agent includes thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester, and the mass ratio of thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester is 4:6:5:1.

[0035] Comparative Example 2 This comparative example provides a composite additive for a pure electric vehicle gearbox oil, which includes the following components in percentage by mass: 10% of an antioxidant phenothiazine, 12% of a friction index improver sulfurized fatty acid amine salt, 0.3% of an anti-foaming agent perfluorocyclobutyl aromatic ether silicone oil, 74.7% of an anti-wear agent and 3% of a rust inhibitor benzotriazole, wherein the anti-wear agent includes thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester, and the mass ratio of thiophosphate amine salt, phosphate ester, phosphonate ester and thiophosphate ester is 4:6:5:1.

[0036] Comparative Example 3 This comparative example provides a composite additive for a pure electric vehicle gearbox oil, which includes the following components in percentage by mass: 10% of an antioxidant aminosilicone-modified phenylphenothiazine, 12% of a friction index improver sulfurized fatty acid amine salt, 0.3% of an anti-foaming agent silicone oil, 74.7% of an anti-wear agent, and 3% of a rust inhibitor benzotriazole, wherein the anti-wear agent includes thiophosphate amine salt, phosphate ester, phosphonate ester, and thiophosphate ester, and the mass ratio of thiophosphate amine salt, phosphate ester, phosphonate ester, and thiophosphate ester is 4:6:5:1.

[0037] 0.5 g of the composite additives in Example 1 and Comparative Examples 1-3 were respectively mixed with 95.5 g of SK YUBASE® 4 base oil to prepare reduction gearbox oils.

[0038] The anti-oxidation performance of the gearbox oils prepared with the composite additives for gearbox oils of pure electric vehicles according to Example 1 and Comparative Examples 1-3 was tested. Specifically, the oxidation induction time (OIT) of each sample was tested by a rotating oxygen bomb test (RBOT) as a test indicator of the anti-oxidation performance.

[0039] Add 50g of gearbox oil sample, 55.6g of 99.5% copper coil, and 5mL of distilled water to a glass test dish. The test dish is sealed in a stainless steel bomb and filled with 620kPa of pure oxygen at 25°C. The bomb is heated to 180°C in dimethyl silicone oil while the bomb is kept rotating. The time when the maximum pressure drops by 175kPa is recorded. This is recorded as the oxidation induction period of the gearbox oil.

[0040] Take another glass test dish and continue the oxidation induction period test. In this test, the projectile is heated to 150°C in dimethyl silicone oil and the oxidation induction period of the gearbox oil is recorded.

[0041] The results of the oxidation induction period of the reduction gearbox oils prepared in Example 1 and Comparative Examples 1-3 are as follows: Figure 1 As shown by Figure 1 It can be seen that the oxidation induction period of the gearbox oil obtained in Comparative Example 3 and Example 1 is not much different, while the oxidation induction period of the gearbox oil obtained in Comparative Example 2 is much lower than that in Example 1, and the oxidation induction period of the gearbox oil obtained in Comparative Example 1 and Comparative Example 2 is similar. This is because the multiple secondary amine groups in the aminosiloxane-modified phenylphenothiazine can increase the oxidation induction period of the gearbox oil and have a better antioxidant effect.

[0042] And from the comparison of the oxidation induction period at 150°C and the oxidation induction period at 180°C in Table 1, it can be seen that after the phenylphenothiazine is modified with aminosilicone, the high-temperature antioxidant effect is not greatly attenuated, while without the aminosilicone modification of phenylphenothiazine, the high-temperature antioxidant effect of Comparative Example 1 and Comparative Example 2 is greatly attenuated.

[0043] The viscosity and sediment changes of the gearbox oils of Example 1 and Comparative Examples 1-3 were tested respectively. The specific method is as follows: a glass test tube containing 50 g of the gearbox oil sample was placed in a 180°C heated oil bath, dry air was passed into the sample, the air flow rate was 50 mL / min, and the oxidation time was 140 h. After the oxidation was completed, the sample was poured into a 100 mL centrifuge tube and centrifuged at 1825 r / min for half an hour. The lower sample was taken and washed with petroleum ether, and the petroleum ether insoluble matter was filtered with filter paper. After drying, it was weighed and recorded as the total amount of sediment.

[0044] The test results of the total amount of sediment in the gearbox oil prepared by using the composite additives of Example 1 and Comparative Examples 1-3 as the gearbox oil additive are as follows: Figure 2 shown.

[0045] Depend on Figure 2 It can be seen that the total amount of sediment in Comparative Example 3 is similar to that in Example 1, while the total amount of sediment in Comparative Example 1 and Comparative Example 2 is greater than that in Example 1, and the sediment in Comparative Example 2 is greater than that in Comparative Example 1. Connecting a benzene ring to the N of phenothiazine can reduce the generation of sludge, and using aminosiloxane to modify phenylphenothiazine, the flexible structure of the siloxane chain can wrap the active group of phenothiazine, further reducing the generation of sludge.

[0046] The anti-foaming performance of the gearbox oils prepared using the composite additives of Example 1 and Comparative Examples 1-3 as gearbox oil additives was tested. The test method was based on GB / T 12579-2002, and the specific method was as follows: 50 g of the gearbox oil sample was placed in a measuring cylinder and preheated to the test temperature in a constant temperature bath at 24°C. The gas diffusion head was immersed in the bottom of the sample, and dry air was introduced at 94 mL / min for 5 minutes. The foam volume was recorded immediately after the ventilation was completed as the foam tendency result. After stopping the ventilation and letting it stand for 10 minutes, the foam volume was recorded again as the foam stability result.

[0047] Change the test temperature to 93.5℃ and conduct the test again, recording the foam tendency results and foam stability results respectively. When the foam disappears, repeat the test at 24℃.

[0048] The anti-foaming performance test results are shown in Table 1.

[0049] Table 1 Test results of anti-foaming performance of reduction gearbox oils prepared in Example 1 and Comparative Examples 1-3

[0050] As can be seen from Table 1, in Comparative Example 3, perfluorocyclobutyl aryl ether silicone oil is not used as an anti-foaming agent, and the anti-foaming performance of the reduction gear oil is reduced. This is because the close arrangement of fluorine atoms in the perfluorocyclobutyl group can further reduce the surface tension of the silicone oil and improve the defoaming effect.

[0051] The insulation performance of the gearbox oil prepared by using the composite additives of Example 1 and Comparative Examples 1-3 as gearbox oil additives was tested. The test method was based on GB / T 5654-2007. The specific method was as follows: After preheating the gearbox oil sample at 90°C for 30 minutes, the sample was slowly poured into the electrode cup to ensure that the liquid surface completely covered the electrode. The electrode spacing was 3mm, the electrode material was platinum-plated, and the electrode surface finish Ra ≤ 0.1μm. Then, a DC power supply was connected and a voltage of 500V was applied and stabilized for 1 minute. The current value after stabilization was recorded, and the volume resistivity was calculated. The calculation formula of the volume resistivity was: volume resistivity = (applied voltage / current value) × (electrode effective area / electrode spacing). The experimental results are shown in FIG. Figure 3 shown.

[0052] Depend on Figure 3 It can be seen that the volume resistivity of the reduction gear oil prepared in Comparative Example 3 is lower than that in Example 1 and Comparative Examples 1 and 2, indicating that perfluorocyclobutyl aryl ether silicone oil can improve the electrical insulation performance of the reduction gear oil.

[0053] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A composite additive for pure electric vehicle reduction gearbox oil, characterized in that: In terms of mass percentage, it includes the following components: 8-12% antioxidant, 10-15% friction index improver, 0.1-0.5% anti-foaming agent, 70-78% anti-wear agent and 2-5% rust inhibitor; The antioxidant is aminosiloxane-modified phenylphenothiazine, and the anti-foaming agent is perfluorocyclobutyl aryl ether silicone oil.

2. The composite additive for reduction gearbox oil of pure electric vehicle according to claim 1, characterized in that: The anti-wear agent comprises thiophosphite amine salt, phosphate, phosphonate and thiophosphate in a mass ratio of 4:6:5:1; the rust inhibitor is benzotriazole; and the friction index improver is phosphate or sulfurized fatty acid amine salt.

3. The composite additive for reduction gearbox oil of pure electric vehicle according to claim 2, characterized in that: The composition includes the following components by mass percentage: 10% antioxidant, 12% friction index improver, 0.3% anti-foaming agent, 74.7% anti-wear agent and 3% rust inhibitor.

4. A method for preparing the composite additive for reduction gearbox oil of pure electric vehicles according to claim 1, characterized in that: The following steps are involved: S1. Under nitrogen protection, toluene, bromophenylphenothiazine and 3-aminopropyltriethoxysilane are mixed, and a catalyst trisdibenzylideneacetone dipalladium and 4,5-bisdiphenylphosphine-9,9-dimethylxanthene are added thereto, and potassium tert-butoxide is added at the same time. The mixture is reacted at 80-85° C. for 4-6 hours. After the reaction is completed, the mixture is cooled and filtered. The filter residue is washed with ethyl acetate, and then distilled under reduced pressure at 6.7 kPa and 30° C., and then separated and purified using a basic alumina chromatography column to obtain aminosiloxane-modified phenylphenothiazine; S2, using dimethyldimethoxysilane and 1-bromo-4-((1,2,2-trifluorovinyl)oxy)benzene as raw materials, preparing aryl trifluorovinyl ether silane through Grignard reaction; Perfluorocyclobutyl aryl ether silane was prepared by thermal cyclization reaction of aryl trifluorovinyl ether silane under argon protection. Under argon protection, using anhydrous acetic acid as solvent, perfluorocyclobutyl aryl ether silane and dimethyldiethoxysilane as raw materials, the reaction was carried out at 90-95°C for 24 hours. After the reaction, the mixture was cooled to room temperature, the acetic acid was removed by rotary evaporation, and perfluorocyclobutyl aryl ether silicone oil was obtained by vacuum distillation. S3. Add aminosiloxane-modified phenylphenothiazine, perfluorocyclobutyl aryl ether silicone oil, friction index improver, anti-wear agent and rust inhibitor into the reactor in sequence, stir at a speed of 300-400 r / min for 40-60 min, and let it stand for 40-60 min after mixing to obtain a composite additive for pure electric vehicle gearbox oil.

5. The method for preparing the composite additive for reduction gearbox oil of pure electric vehicles according to claim 4, characterized in that: In step S1, the preparation method of the bromophenylphenothiazine is as follows: phenylphenothiazine is dissolved in tetrahydrofuran, N-bromosuccinamide is added thereto in an ice-water bath at 5°C, the reaction temperature is controlled at 3-5°C, the reaction is carried out for 6-8 hours, and then the reaction solution is poured into water and stirred to precipitate a solid, the filter cake is washed with distilled water after suction filtration, and the filter cake is dried to obtain bromophenylphenothiazine.

6. The method for preparing the composite additive for reduction gearbox oil of pure electric vehicles according to claim 5, characterized in that: The preparation method of phenylphenothiazine comprises the following steps: adding phenothiazine, copper powder, potassium carbonate and iodobenzene to chlorobenzene, heating the mixture to 190-195° C. for reaction for 10 hours, cooling the mixture to room temperature after the reaction is completed, then heating the mixture to 195° C. again for distillation to remove the remaining iodobenzene, cooling the mixture to room temperature again, adding anhydrous ethanol, heating the mixture to 70° C. for stirring for 10 minutes, and immediately filtering the mixture, collecting the filtrate for room temperature crystallization, filtering the precipitate, and drying the mixture to obtain phenylphenothiazine.

7. The method for preparing the composite additive for reduction gearbox oil of pure electric vehicles according to claim 4, characterized in that: In step S1, the molar ratio of bromophenylphenothiazine, 3-aminopropyltriethoxysilane, trisdibenzylideneacetone dipalladium, 4,5-bisdiphenylphosphine-9,9-dimethylxanthene and potassium tert-butoxide is 1:3:0.025:0.03~0.04:1.4, and the eluent in the chromatography column separation and purification process is a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 1:

1.

8. The method for preparing the composite additive for reduction gearbox oil of pure electric vehicles according to claim 4, characterized in that: In step S2, the molar ratio of the perfluorocyclobutyl aryl ether silane to dimethyldiethoxysilane is 1:

1.

9. The method for preparing the composite additive for reduction gearbox oil of pure electric vehicles according to claim 5, characterized in that: The molar ratio of the phenylphenothiazine to the N-bromosuccinamide is 3:2.5-2.

8.

10. The method for preparing the composite additive for reduction gearbox oil of pure electric vehicles according to claim 6, characterized in that: The molar ratio of phenothiazine, iodobenzene, copper powder and potassium carbonate is 1:2.1:0.73-0.8:3.23-3.26.

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