Automatic transmission oil additive and preparation method thereof

Abstract

The present invention belongs to the technical field of gearbox oil additives, and in particular to a kind of automatic gearbox oil additive and preparation method thereof, which comprises the following components by weight: 15-20 parts of antiwear agent one, 5-10 parts of antiwear agent two, 16-20 parts of antioxidant, 40-50 parts of detergent, 3-6 parts of anticorrosive agent, 1-2 parts of initiator, 4-6 parts of friction modifier; the antiwear agent one is phosphomolybdic heteropolyquaternary ammonium salt nanocomposite microsphere, the antiwear agent two is a three-dimensional metal organic framework microcapsule loaded with DAO, and the initiator is azobisisobutyronitrile; the antiwear agent one is prepared by ion exchange of phosphomolybdic acid and 3-acrylamidopropyl dodecyl dimethyl ammonium bromide. The automatic gearbox oil additive in the present invention can reduce the friction coefficient between two friction pairs, reduce the wear between friction pairs, and has a longer service life and better effect.

Description

Technical Field

[0001] The invention belongs to the technical field of transmission oil additives, and in particular relates to an automatic transmission oil additive and a preparation method thereof. Background Art

[0002] The base oil of automatic transmission oil is usually extracted from paraffin-based crude oil, referred to as mineral oil. However, due to the inherent characteristics of the base oil, various types of additives must be added to meet the requirements of various working conditions in order to meet the normal use of the transmission. Automatic transmission oil is prepared by adding various additives such as viscosity index improvers, anti-wear agents, friction modifiers, dispersants, detergents, etc. to the base oil. Good automatic transmission oil can reduce the failure of the automatic transmission itself and extend the service life of the transmission.

[0003] The advantages of easy operation, comfortable driving, and reduced driver fatigue make the automatic transmission a major trend in modern automobile configuration. As the second most expensive part of a car, lubrication is crucial to the use and maintenance of the automatic transmission. However, as people's requirements for driving performance become higher and higher and vehicle transmission technology continues to advance, users have put forward higher requirements for the performance of automatic transmission oil. From the perspective of use, everyone hopes that the transmission oil used has better lubrication effect and longer replacement interval. Summary of the invention

[0004] The object of the present invention is to provide an automatic transmission oil additive and a preparation method thereof, so as to improve the lubricating effect of the transmission oil, increase the service life of the transmission oil, and extend the replacement interval mileage.

[0005] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0006] An automatic transmission oil additive, comprising the following components by weight: 15-20 parts of antiwear agent 1, 5-10 parts of antiwear agent 2, 16-20 parts of antioxidant, 40-50 parts of detergent, 3-6 parts of anticorrosive agent, 1-2 parts of initiator, and 4-6 parts of friction modifier;

[0007] The first anti-wear agent is a phosphomolybdenum heteropolyquaternary ammonium salt nanocomposite microsphere, the second anti-wear agent is a three-dimensional metal organic framework microcapsule loaded with DAO, and the initiator is azobisisobutyronitrile;

[0008] The anti-wear agent 1 is prepared by ion exchange between phosphomolybdic acid and 3-acrylamidopropyl dodecyl dimethyl ammonium bromide.

[0009] As a further improvement, the antioxidant is a dialkyl dithiocarbamate, the detergent is a sulfurized alkyl phenol salt, the anti-corrosion agent is an organic phosphate, and the friction modifier is hexadecanol.

[0010] As a further improvement, the following components are included by weight: 18 parts of antiwear agent 1, 8 parts of antiwear agent 2, 18 parts of antioxidant, 45 parts of detergent, 5 parts of anticorrosion agent, 1 part of initiator, and 5 parts of friction modifier.

[0011] The present invention also provides a method for preparing an automatic transmission oil additive, comprising the following steps:

[0012] S1. Preparation of phosphomolybdenum heteropolyquaternary ammonium salt nanocomposite microspheres;

[0013] Dimethylaminopropyl acrylamide and dodecane bromide react to obtain 3-acrylamidopropyl dodecyl dimethyl ammonium bromide;

[0014] The aqueous solution of phosphomolybdic acid and the ethanol solution of 3-acrylamidopropyl dodecyl dimethyl ammonium bromide were mixed, reacted at 30°C for 4 hours, and after the reaction was completed, the precipitate was filtered out by suction, washed with ethanol aqueous solution, vacuum dried and dissolved in acetone, distilled water was added dropwise until the solution was turbid, and filtered after standing for two days to obtain phosphomolybdic heteropoly quaternary ammonium salt nanocomposite microspheres;

[0015] S2, preparation of three-dimensional metal-organic framework microcapsules loaded with DAO;

[0016] DAO is dissolved in dimethylformamide, and then added dropwise to the dimethylformamide containing the three-dimensional metal organic framework material, stirred overnight, and then the precipitate is separated by centrifugation and vacuum dried to obtain the three-dimensional metal organic framework loaded with DAO;

[0017] Add a silica dispersion to a mixed solution of water and anhydrous ethanol, stir magnetically for 20 minutes at 50° C., then add a three-dimensional metal organic framework loaded with DAO, centrifuge at 12,000 rpm for 5 minutes, add 2 drops of n-octanol defoamer, adjust the pH of the system to 10, heat the system to 80° C. in a water bath, add tetraethyl silicate, react for 2 hours, filter, and dry to obtain a three-dimensional metal organic framework microcapsule loaded with DAO;

[0018] S3. Weigh antiwear agent 1, antiwear agent 2, antioxidant, detergent, anticorrosive agent, initiator and friction modifier, pour into a mixing and stirring device, mix at 20-25° C., then heat to 45-50° C., and continue stirring for 60 minutes to obtain an automatic transmission oil additive.

[0019] As a further improvement, in step S1, the preparation method of the 3-acrylamidopropyldodecyldimethylammonium bromide is specifically as follows: dimethylaminopropylacrylamide and dodecane bromide react under nitrogen protection and room temperature to obtain a transparent gel, then a white solid is precipitated under liquid nitrogen cooling, the solid is washed with ether and then vacuum dried, and the dried substance is then washed with a mixed solvent of acetone and ether and then recrystallized.

[0020] As a further improvement, in step S1, the molar ratio of the phosphomolybdic acid to the 3-acrylamidopropyldodecyldimethylammonium bromide is 1:2.

[0021] As a further improvement, in step S2, the preparation method of DAO is specifically as follows: diacetone acrylamide and oleylamine are mixed in a molar ratio of 1:1, reacted at 80° C. and a vacuum degree of 0.095 MPa for 24 hours, and then filtered and dried to obtain DAO.

[0022] As a further improvement, in step S2, the preparation method of the three-dimensional metal-organic framework material is specifically as follows: zinc nitrate hexahydrate, dimethylimidazole and histidine are respectively dissolved in deionized water, and then the three solutions are quickly stirred and mixed at room temperature, centrifuged at a speed of 6000g for 5 minutes after 5 minutes, and then washed twice with deionized water, and dried to obtain the three-dimensional metal-organic framework material, wherein the molar ratio of zinc nitrate hexahydrate, dimethylimidazole and histidine is 2:7:1.

[0023] As a further improvement, in step S2, the mass ratio of the silicon dioxide to the three-dimensional metal organic framework loaded with DAO is 10:1, and the mass ratio of the three-dimensional metal organic framework loaded with DAO to the tetraethyl silicate is 1.5:1.

[0024] As a further improvement, in step S2, the mass ratio of the DAO to the three-dimensional metal-organic framework material is 2:1.

[0025] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0026] The invention provides an automatic transmission oil additive, which can reduce the friction coefficient between two friction pairs, reduce the wear between the friction pairs, and has a longer service life and better effect.

[0027] In the present invention, the phosphorus molybdenum heteropoly quaternary ammonium salt nanocomposite microspheres are used as an anti-wear agent, have a smooth surface and a spherical morphology, and are used as an anti-wear agent in the initial use, playing the role of a rolling bearing between two friction pairs. After being used for a period of time, the inorganic components on the surface of the composite microspheres fall off due to friction, and the internal quaternary ammonium salt contains amide groups and alkyl long chains. After the inorganic components fall off, the amide groups are adsorbed on the surface of the friction pair as polar groups, and the alkyl long chains in the quaternary ammonium salt form a protective film outward as non-polar groups, which plays the role of reducing the friction coefficient between the two friction pairs; at the same time, after the automatic transmission oil is used for a period of time, the temperature of the automatic transmission oil increases, and under the action of the initiator azobisisobutylnitrile, the carbon-carbon double bonds in the quaternary ammonium salt are polymerized, and an organic polymer film is formed between the two friction pairs, which further reduces the friction coefficient between the two friction pairs.

[0028] In the present invention, the three-dimensional metal organic framework microcapsule loaded with DAO is used as the second anti-wear agent, which can reduce the wear between the two friction pairs. After the automatic transmission oil is used for a period of time, the outer wall of the microcapsule is broken, and the three-dimensional metal organic framework loaded with DAO is released. At the same time, DAO is released from the three-dimensional metal organic framework material. The three-dimensional metal organic framework has the function of a rolling contact bearing, and continues to realize the function of an anti-wear agent between the two friction pairs. DAO forms a chemical protective film between the two friction pairs, so that the two friction pairs return to liquid lubrication. The presence of the amide group in its head group can form a boundary film with a unique double-layer structure, reduce the friction coefficient between the two friction pairs, and increase the service life of the lubricating oil additive.

[0029] The automatic transmission oil additive of the present invention does not need to add a dispersant, and the first antiwear agent and the second antiwear agent can be well dispersed in the transmission oil. DETAILED DESCRIPTION

[0030] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated 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, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0031] Example 1 An automatic transmission oil additive comprises the following components by weight: 15-20 parts of antiwear agent 1, 5-10 parts of antiwear agent 2, 16-20 parts of antioxidant, 40-50 parts of detergent, 3-6 parts of anticorrosive agent, 1-2 parts of initiator, and 4-6 parts of friction modifier;

[0032] The first anti-wear agent is phosphomolybdenum heteropolyquaternary ammonium salt nanocomposite microspheres, the second anti-wear agent is a three-dimensional metal organic framework microcapsule loaded with DAO, the initiator is azobisisobutyronitrile, the antioxidant is a dialkyl dithiocarbamate, the detergent is a sulfurized alkylphenol salt, the anti-corrosion agent is an organic phosphate, and the friction modifier is hexadecanol.

[0033] Example 2 An automatic transmission oil additive comprises the following components by weight: 15 parts of antiwear agent 1, 5 parts of antiwear agent 2, 20 parts of antioxidant, 46 parts of detergent, 6 parts of anticorrosive agent, 2 parts of initiator, and 6 parts of friction modifier.

[0034] Example 3 An automatic transmission oil additive comprises the following components, by weight: 20 parts of antiwear agent 1, 10 parts of antiwear agent 2, 16 parts of antioxidant, 46 parts of detergent, 3 parts of anticorrosive agent, 1 part of initiator, and 4 parts of friction modifier.

[0035] Example 4 An automatic transmission oil additive comprises the following components by weight: 20 parts of antiwear agent 1, 10 parts of antiwear agent 2, 16 parts of antioxidant, 40 parts of detergent, 6 parts of anticorrosive agent, 2 parts of initiator, and 6 parts of friction modifier.

[0036] Example 5 An automatic transmission oil additive comprises the following components, by weight: 18 parts of antiwear agent 1, 8 parts of antiwear agent 2, 16 parts of antioxidant, 50 parts of detergent, 3 parts of anticorrosive agent, 1 part of initiator, and 4 parts of friction modifier.

[0037] Example 6 An automatic transmission oil additive comprises the following components, by weight: 18 parts of antiwear agent 1, 8 parts of antiwear agent 2, 18 parts of antioxidant, 45 parts of detergent, 5 parts of anticorrosive agent, 1 part of initiator, and 5 parts of friction modifier;

[0038] The first anti-wear agent is phosphomolybdenum heteropolyquaternary ammonium salt nanocomposite microspheres, the second anti-wear agent is a three-dimensional metal organic framework microcapsule loaded with DAO, the initiator is azobisisobutyronitrile, the antioxidant is a dialkyl dithiocarbamate, the detergent is a sulfurized alkylphenol salt, the anti-corrosion agent is an organic phosphate, and the friction modifier is hexadecanol.

[0039] Example 7 This example provides a method for preparing the automatic transmission oil additive in Example 6, comprising the following steps:

[0040] S1. Preparation of anti-wear agent-phosphomolybdenum heteropolyquaternary ammonium salt nanocomposite microspheres;

[0041] 0.035 mol of dimethylaminopropyl acrylamide and 0.052 mol of dodecane bromide were mixed, stirred evenly under nitrogen protection, and then reacted at room temperature for 48 hours. Unreacted dodecane bromide was poured out to obtain a transparent gel, and a white solid was precipitated under liquid nitrogen cooling. After washing with ether and vacuum drying for 30 minutes, it was washed with a mixed solvent of acetone and ether in a volume ratio of 1:1 and then recrystallized to obtain 3-acrylamidopropyldodecyldimethylammonium bromide;

[0042] 0.4508 g of phosphomolybdic acid was dissolved in distilled water, 0.2012 g of 3-acrylamidopropyl dodecyl dimethyl ammonium bromide was dissolved in ethanol, the two solutions were mixed, reacted at 30° C. for 4 h, filtered to obtain a precipitate after the reaction was completed, washed the precipitate twice with ethanol aqueous solution, and then vacuum dried at 70° C. The obtained substance was dissolved in acetone, and distilled water was added dropwise thereto until the solution was turbid, and filtered after standing for two days to obtain phosphomolybdic heteropoly quaternary ammonium salt nanocomposite microspheres, wherein the molar ratio of phosphomolybdic acid to 3-acrylamidopropyl dodecyl dimethyl ammonium bromide was 1:2;

[0043] S2, preparation of three-dimensional metal organic framework microcapsules loaded with DAO;

[0044] 3.38 g of diacetone acrylamide and 5.35 g of oleylamine were mixed, and then reacted at 80° C. and vacuum degree 0.095 MPa for 24 h, and then filtered and dried to obtain DAO, wherein the molar ratio of diacetone acrylamide to oleylamine was 1:1;

[0045] 0.5978 g of zinc nitrate hexahydrate, 0.5747 g of dimethylimidazole and 0.1552 g of histidine were respectively dissolved in deionized water, and then the three solutions were quickly stirred and mixed at room temperature, centrifuged at a speed of 6000 g for 5 min after 5 min, and then washed twice with deionized water and dried to obtain a three-dimensional metal organic framework material, wherein the molar ratio of zinc nitrate hexahydrate, dimethylimidazole and histidine was 2:7:1;

[0046] 20 g of DAO was dissolved in 10 mL of dimethylformamide, and then added dropwise to a dimethylformamide solution containing 10 g of a three-dimensional metal-organic framework material, stirred overnight, and then the precipitate was separated by centrifugation and vacuum dried to obtain a three-dimensional metal-organic framework loaded with DAO;

[0047] 5 g of 20% silica dispersion was added to 100 mL of a mixed solution of water and anhydrous ethanol (the volume ratio of water to anhydrous ethanol was 9:1), magnetically stirred at 50°C for 20 min, then 10 g of a three-dimensional metal organic framework loaded with DAO was added thereto, centrifuged at 12000 rpm for 5 min, 2 drops of n-octanol defoamer were added thereto, the pH of the system was adjusted to 10 with sodium hydroxide, the system was heated to 80°C in a water bath, 6.67 g of tetraethyl silicate was added thereto, after reacting for 2 h, the three-dimensional metal organic framework loaded with DAO was filtered and dried to obtain a three-dimensional metal organic framework microcapsule loaded with DAO. Among them, the mass ratio of silica to the three-dimensional metal organic framework loaded with DAO was 1:10, and the mass ratio of the three-dimensional metal organic framework loaded with DAO to tetraethyl silicate was 1.5:1.

[0048] S3. Weigh 18 parts of antiwear agent 1, 8 parts of antiwear agent 2, 18 parts of antioxidant, 45 parts of detergent, 5 parts of anticorrosion agent, 1 part of initiator and 5 parts of friction modifier, pour them into a mixing and stirring device, mix at 20-25°C, then heat to 45-50°C, and continue stirring for 60 minutes to obtain an automatic transmission oil additive.

[0049] Example 8 In this example, the friction coefficient and wear spot diameter of the antiwear agent 1, the antiwear agent 2 and the automatic transmission oil additive prepared in the present invention were measured by a four-ball test.

[0050] Antiwear agent 1, antiwear agent 2, the automatic transmission oil additive prepared in Example 7 and existing Al2O3 / SiO2 nanoparticles were added to the base lubricating oil at a concentration of 0.5wt%, stirred at room temperature for 30min, ultrasonically dispersed for 30min, and aged for 24h to obtain four groups of lubricating oils.

[0051] Clean the steel ball, oil box and fixture with petroleum ether and then blow dry; start the testing machine and preheat for 10 minutes, then stop, install 4 steel balls on the friction and wear testing machine, and pour an appropriate amount of sample oil into the oil box; reset the test force and friction force to zero, turn the oil valve to manual gear, slowly apply the load to about 37N, and then switch the oil valve to automatic gear; when the upper and lower balls are about to touch, reset the test force again, and start the testing machine when the temperature rises to 75℃; after the testing machine stops running, turn the oil valve from automatic gear to manual gear, slowly reduce the pressure, and record the wear spot diameters of the three steel balls in the oil box. The average friction coefficient and wear spot diameter results of the four groups of lubricants in this test are shown in Table 1.

[0052] Table 1 Summary of average friction coefficient and wear spot diameter of four groups of lubricants

[0053] Group Antiwear agent Antiwear agent 2 Automatic Transmission Fluid Additives <![CDATA[Al2O3 / SiO2 nanoparticles]]> Wear spot diameter / μm 230.65 233.74 215.96 248.86 Average friction coefficient 0.025818 0.025638 0.021506 0.03966

[0054] It can be seen from Table 1 that the antiwear agent 1 and the antiwear agent 2 prepared in the present application can reduce the wear spot diameter compared with the existing Al2O3 / SiO2 nanoparticles, and have better antiwear effect, and the automatic transmission oil additive prepared in the present application has the best antiwear effect. The antiwear agent 1 and the antiwear agent 2 prepared in the present application can both reduce the friction coefficient, and the friction coefficient of the automatic transmission oil additive prepared in the present application is the smallest.

[0055] Example 9 This example uses a thrust ring test to test the wear quality of the friction pair when the antiwear agent 1, antiwear agent 2, and automatic transmission oil additive prepared in the present invention are used.

[0056] Antiwear agent 1, antiwear agent 2, the automatic transmission oil additive prepared in Example 7 and existing Al2O3 / SiO2 nanoparticles were added to the base lubricating oil at a concentration of 0.5wt%, stirred at room temperature for 30min, ultrasonically dispersed for 30min, and aged for 24h to obtain four groups of lubricating oils.

[0057] Clean the test ring, thrust ring, fixture and oil tank with petroleum ether, and then blow dry; start the test machine and preheat for 10 minutes, then install the thrust ring and test ring on the friction and wear tester, and pour an appropriate amount of sample oil into the oil tank; reset the test force and friction force, then turn the oil valve to manual gear, and slowly apply the load to 50N when the oil valve is switched to automatic gear; when the thrust ring and the test ring are about to contact, reset the test force again, and start the test machine when the temperature rises to 75℃; after the test machine stops running, turn the oil valve from automatic gear to manual gear, slowly reduce the pressure, and record the mass change of the friction pair. The test results are shown in Table 2.

[0058] Table 2 Wear quality results of friction pairs when using four groups of lubricants

[0059] Group Antiwear agent Antiwear agent 2 Automatic Transmission Fluid Additives <![CDATA[Al2O3 / SiO2 nanoparticles]]> Wear mass / g 0.015 -0.015 0.003 -0.008

[0060] It can be seen from Table 2 that after adding the anti-wear agent 1 prepared in this application and the automatic transmission oil additive to two groups of lubricating oils, the wear mass of the friction pair is positive, and negative wear occurs. During the friction process, the friction pair surface has two processes of wear and repair at the same time, that is, there is a material wear process on the friction pair surface at the same time, and there is also a deposition process of the anti-wear agent 1 to the friction pair surface. When the two are unbalanced, it manifests as wear or negative wear, and when balanced, it manifests as zero wear, which depends on the dynamic balance between the film formation rate and the wear rate of the self-repairing film. This is because the anti-wear agent 1 prepared in this application, as an anti-wear agent in the initial use, plays the role of a rolling bearing between the two friction pairs. After the automatic transmission oil has been used for a period of time, the temperature of the automatic transmission oil rises. At the same time, under the action of the initiator azobisisobutylnitrile, the carbon-carbon double bonds in the quaternary ammonium salt are polymerized to form an organic polymer film between the two friction pairs, further reducing the friction coefficient between the two friction pairs.

[0061] The specific implementation of the present invention described above does not constitute a limitation on the protection scope 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 protection scope of the claims of the present invention.

Claims

1. An automatic transmission oil additive, characterized in that: The composition comprises the following components by weight: 15-20 parts of antiwear agent 1, 5-10 parts of antiwear agent 2, 16-20 parts of antioxidant, 40-50 parts of detergent, 3-6 parts of anticorrosive agent, 1-2 parts of initiator, and 4-6 parts of friction modifier; The first anti-wear agent is a phosphomolybdenum heteropolyquaternary ammonium salt nanocomposite microsphere, the second anti-wear agent is a three-dimensional metal organic framework microcapsule loaded with DAO, and the initiator is azobisisobutyronitrile; The anti-wear agent 1 is prepared by ion exchange of phosphomolybdic acid and 3-acrylamidopropyl dodecyl dimethyl ammonium bromide; The preparation method of the three-dimensional metal organic framework microcapsules loaded with DAO is as follows: DAO is dissolved in dimethylformamide, and then the solution is added dropwise to the dimethylformamide containing the three-dimensional metal organic framework material, stirred overnight, and then the precipitate is separated by centrifugation and vacuum dried to obtain the three-dimensional metal organic framework loaded with DAO; a silicon dioxide dispersion is added to a mixed solution of water and anhydrous ethanol, magnetically stirred at 50° C. for 20 minutes, and then the three-dimensional metal organic framework loaded with DAO is added thereto, centrifuged at a speed of 12000 rpm for 5 minutes, 2 drops of n-octanol defoamer are added thereto, the pH of the system is adjusted to 10, the system is heated to 80° C. in a water bath, tetraethyl silicate is added thereto, after reacting for 2 hours, filtering and drying to obtain the three-dimensional metal organic framework microcapsules loaded with DAO; The preparation method of DAO is as follows: diacetone acrylamide and oleylamine are mixed in a molar ratio of 1:1, reacted at 80° C. and a vacuum degree of 0.095 MPa for 24 hours, and then filtered and dried to obtain DAO.

2. The automatic transmission oil additive according to claim 1, characterized in that: The antioxidant is dialkyl dithiocarbamate, the detergent is sulfurized alkyl phenol salt, the anti-corrosion agent is organic phosphate, and the friction modifier is cetyl alcohol.

3. The automatic transmission oil additive according to claim 1, characterized in that: The composition includes the following components by weight: 18 parts of antiwear agent 1, 8 parts of antiwear agent 2, 18 parts of antioxidant, 45 parts of detergent, 5 parts of anticorrosion agent, 1 part of initiator and 5 parts of friction modifier.

4. The method for preparing the automatic transmission oil additive according to claim 1, characterized in that: The following steps are involved: S1. Preparation of phosphomolybdenum heteropolyquaternary ammonium salt nanocomposite microspheres; Dimethylaminopropyl acrylamide and dodecane bromide react to obtain 3-acrylamidopropyl dodecyl dimethyl ammonium bromide; The aqueous solution of phosphomolybdic acid and the ethanol solution of 3-acrylamidopropyl dodecyl dimethyl ammonium bromide were mixed, reacted at 30°C for 4 hours, and after the reaction was completed, the precipitate was filtered out by suction, washed with ethanol aqueous solution, vacuum dried and dissolved in acetone, distilled water was added dropwise until the solution was turbid, and filtered after standing for two days to obtain phosphomolybdic heteropoly quaternary ammonium salt nanocomposite microspheres; S2, preparation of three-dimensional metal-organic framework microcapsules loaded with DAO; DAO is dissolved in dimethylformamide, and then added dropwise to the dimethylformamide containing the three-dimensional metal organic framework material, stirred overnight, and then the precipitate is separated by centrifugation and vacuum dried to obtain the three-dimensional metal organic framework loaded with DAO; Add a silica dispersion to a mixed solution of water and anhydrous ethanol, stir magnetically for 20 minutes at 50° C., then add a three-dimensional metal organic framework loaded with DAO, centrifuge at 12,000 rpm for 5 minutes, add 2 drops of n-octanol defoamer, adjust the pH of the system to 10, heat the system to 80° C. in a water bath, add tetraethyl silicate, react for 2 hours, filter, and dry to obtain a three-dimensional metal organic framework microcapsule loaded with DAO; S3. Weigh antiwear agent 1, antiwear agent 2, antioxidant, detergent, anticorrosive agent, initiator and friction modifier, pour into a mixing and stirring device, mix at 20-25° C., then heat to 45-50° C., and continue stirring for 60 minutes to obtain an automatic transmission oil additive.

5. The method for preparing the automatic transmission oil additive according to claim 4, characterized in that: In step S1, the preparation method of 3-acrylamidopropyldodecyldimethylammonium bromide is specifically as follows: dimethylaminopropylacrylamide and dodecane bromide react under nitrogen protection and room temperature to obtain a transparent gel, then a white solid is precipitated under liquid nitrogen cooling, the solid is washed with ether and then vacuum dried, and the dried substance is then washed with a mixed solvent of acetone and ether and then recrystallized.

6. The method for preparing the automatic transmission oil additive according to claim 4, characterized in that: In step S1, the molar ratio of the phosphomolybdic acid to the 3-acrylamidopropyldodecyldimethylammonium bromide is 1:

2.

7. The method for preparing the automatic transmission oil additive according to claim 4, characterized in that: In step S2, the preparation method of DAO is specifically as follows: diacetone acrylamide and oleylamine are mixed in a molar ratio of 1:1, reacted at 80° C. and a vacuum degree of 0.095 MPa for 24 hours, and then filtered and dried to obtain DAO.

8. The method for preparing the automatic transmission oil additive according to claim 4, characterized in that: In step S2, the preparation method of the three-dimensional metal-organic framework material is specifically as follows: zinc nitrate hexahydrate, dimethylimidazole and histidine are respectively dissolved in deionized water, and then the three solutions are quickly stirred and mixed at room temperature, centrifuged at a speed of 6000r / min for 5 minutes after 5 minutes, and then washed twice with deionized water, and dried to obtain the three-dimensional metal-organic framework material, wherein the molar ratio of zinc nitrate hexahydrate, dimethylimidazole and histidine is 2:7:

1.

9. The method for preparing the automatic transmission oil additive according to claim 4, characterized in that: In step S2, the mass ratio of the silicon dioxide to the three-dimensional metal organic framework loaded with DAO is 10:1, and the mass ratio of the three-dimensional metal organic framework loaded with DAO to the tetraethyl silicate is 1.5:

1.

10. The method for preparing the automatic transmission oil additive according to claim 4, characterized in that: In step S2, the mass ratio of the DAO to the three-dimensional metal organic framework material is 2:1.