Preparation method of viscosity index improver of automatic transmission oil

Abstract

The invention discloses a preparation method of a viscosity index improver for automatic transmission oil. The preparation method comprises the following steps: adopting acrylate or methacrylate with different long carbon chains as monomer ester; the method comprises the following steps: uniformly mixing diluent oil, monomer ester, a chain transfer agent and an initiator, heating 1 / 5 or 1 / 3 of the mixture, adding the rest of the mixture in batches, carrying out a copolymerization reaction, and taking a reaction product as a viscosity index improver of the automatic transmission oil; the addition amount of the chain transfer agent is 0.5%-2% of the total amount of the monomer ester, the addition amount of the initiator is 0.5%-2% of the total amount of the monomer ester, and the diluent oil accounts for 10%-60% of the total amount of the monomer ester. According to the technical scheme, the oxidation resistance of the oil product is remarkably improved while the dispersity of the automatic gearbox oil is improved, the operation method is simple, the process is easy to implement, raw materials are easy to obtain, few waste residues exist, no wastewater treatment pressure exists, and the recovery rate is high.

Description

Technical Field

[0001] The invention relates to the technical field of viscosity index improvers, and in particular to a method for preparing a viscosity index improver for automatic transmission oil. Background Art

[0002] Automatic transmission fluid (ATF) is a multifunctional, multi-purpose lubricant. It plays a role in transmitting power in the torque converter, a hydraulic function in the control and servo system, a lubricating function in the bearing and gear system, and a friction control function in the belt and wet clutch. In addition, it can also take away the heat generated during the transmission process and act as a heat transfer medium.

[0003] Due to the particularity of ATF use, it uses more than 15 kinds of additives, and the largest amount of dispersants (2w%-6w%) and viscosity index improvers (3w%-5w%) account for 60%-70% of the total amount of ATF additives. With the changes and improvements of automatic transmission systems, the viscosity-temperature performance, dispersibility, and antioxidant properties of ATF are increasingly required. During the normal operation of the gearbox, the temperature generated by the gearbox will cause the oil to oxidize rapidly, making the oil thicker and forming sludge, and reducing the heat dissipation performance of the lubricant. In order to extend the oil change cycle of the gearbox oil, a certain amount of antioxidants and dispersants are usually added to the gearbox oil.

[0004] Dispersed PMA viscosity index improvers used in ATF require a unique structural design to achieve the ability to maintain the viscosity of the oil under different working conditions. In some cases, they also need to have dispersibility and control the friction coefficient of the wet clutch plate. Adding a dispersed PMA viscosity index improver can be used in conjunction with a compound agent to reduce the amount of dispersant added while also improving the viscosity retention performance of the oil after oxidation.

[0005] Although the viscosity index improver in the prior art can improve the viscosity index of hydraulic oil products and improve the dispersibility of the oil products to a certain extent, it cannot improve the anti-oxidation performance of the oil products while improving the dispersibility of automatic transmission oil. Summary of the invention

[0006] In view of the above problems, the present invention provides a method for preparing a viscosity index improver for automatic transmission oil. By limiting the types of raw materials and preparation conditions required for the viscosity index improver for automatic transmission oil, the generated viscosity index improver can significantly improve the anti-oxidation performance of the oil while improving the dispersibility of the automatic transmission oil. The operation method is simple, the process is easy to implement, the raw materials are easy to obtain, there is little waste residue, there is no wastewater treatment pressure, the recovery rate is high, and the method has excellent low-temperature performance, viscosity-temperature performance and excellent shear stability in the automatic transmission oil, which helps to disperse the sludge while improving the anti-oxidation performance of the oil.

[0007] To achieve the above object, the present invention provides a method for preparing a viscosity index improver for automatic transmission oil, comprising:

[0008] Using acrylic acid esters or methacrylic acid esters with different carbon chain lengths as monomer esters, wherein C1-C2 methacrylic acid esters account for 1%-10% of the total mass of the monomer esters, C4-C22 methacrylic acid esters account for 3%-80% of the total mass of the monomer esters, and methacrylamide or amino methacrylate accounts for 1%-10% of the total mass of the monomer esters;

[0009] The diluent oil, the monomer ester, the chain transfer agent and the initiator are uniformly mixed, 1 / 5 or 1 / 3 of the mixture is heated to 75-140° C., and the remaining mixture is added in batches to carry out copolymerization reaction for 2-8 hours, and the reaction product is used as a viscosity index improver for automatic transmission oil;

[0010] The amount of the chain transfer agent added is 0.5% to 2% of the total amount of the monomer ester, the amount of the initiator added is 0.5% to 2% of the total amount of the monomer ester, and the diluent oil accounts for 10% to 60% in the reaction system.

[0011] In the above technical scheme, preferably, the methacrylate includes methyl methacrylate, ethyl methacrylate, butyl methacrylate, isooctyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, eicosyl methacrylate, docosyl methacrylate, N,N-dimethylacrylamide, N,N-methylenebisacrylamide, 2-(diethylamino)ethyl methacrylate, 2-(tert-butylamino)ethyl methacrylate and 2-(isopropylamino)ethyl methacrylate.

[0012] In the above technical scheme, preferably, the chain transfer agent is mercaptoethanol, 2-ethylhexyl thioglycolate, 3-butyl mercaptopropionate, 3-mercaptopropyl isooctyl ester, 2-mercaptopropyl acetate isooctyl ester, n-dodecyl mercaptan, tert-dodecyl mercaptan or 2,4-diphenyl-4-methyl-1-pentene.

[0013] In the above technical solution, preferably, the chain transfer agent is 2,4-diphenyl-4-methyl-1-pentene.

[0014] In the above technical solution, preferably, the initiator is azobisisobutyronitrile, benzoyl peroxide, tert-butyl benzoyl peroxide or tert-butyl peroxy-2-ethylhexanoate.

[0015] In the above technical solution, preferably, the initiator is tert-butyl peroxy-2-ethylhexanoate.

[0016] In the above technical solution, preferably, the diluent oil is a combination of one or more of ester oil, synthetic base oil and hydrogenated base oil.

[0017] In the above technical solution, preferably, the diluent oil accounts for 30% to 40% in the reaction system.

[0018] In the above technical solution, preferably, the reaction temperature of the copolymerization reaction is 95-125°C.

[0019] In the above technical solution, preferably, the reaction time of the copolymerization reaction is 3 to 6 hours.

[0020] Compared with the prior art, the present invention has the following beneficial effects: by limiting the types of raw materials and preparation conditions required for the viscosity index improver suitable for automatic transmission oil, the generated viscosity index improver can significantly improve the anti-oxidation performance of the oil product while improving the dispersibility of the automatic transmission oil, and the operation method is simple, the process is easy to implement, the raw materials are easy to obtain, there is less waste residue, there is no wastewater treatment pressure, the recovery rate is high, and the automatic transmission oil has excellent low-temperature performance, viscosity-temperature performance and excellent shear stability, and helps to disperse the sludge while improving the anti-oxidation performance of the oil product. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] The present invention is described in further detail below:

[0023] According to the present invention, a method for preparing a viscosity index improver for automatic transmission oil comprises:

[0024] Using acrylic acid esters or methacrylic acid esters with different carbon chain lengths as monomer esters, wherein C1-C2 methacrylic acid esters account for 1%-10% of the total mass of the monomer esters, C4-C22 methacrylic acid esters account for 3%-80% of the total mass of the monomer esters, and methacrylamide or amino methacrylate accounts for 1%-10% of the total mass of the monomer esters;

[0025] The diluent oil, monomer ester, chain transfer agent and initiator are uniformly mixed, 1 / 5 or 1 / 3 of the mixture is heated to 75-140°C, and then the remaining mixture is added in batches to carry out copolymerization reaction for 2-8 hours, and the reaction product is used as a viscosity index improver for automatic transmission oil;

[0026] The amount of chain transfer agent added is 0.5% to 2% of the total amount of monomer ester, the amount of initiator added is 0.5% to 2% of the total amount of monomer ester, and the diluent oil accounts for 10% to 60% in the reaction system.

[0027] In this embodiment, by limiting the types of raw materials and preparation conditions required for the viscosity index improver suitable for automatic transmission oil, the generated viscosity index improver can significantly improve the anti-oxidation performance of the oil product while improving the dispersibility of the automatic transmission oil, and the operation method is simple, the process is easy to implement, the raw materials are easily available, there is less waste residue, there is no wastewater treatment pressure, the recovery rate is high, and the automatic transmission oil has excellent low temperature performance, viscosity-temperature performance and excellent shear stability, which helps to disperse the sludge while improving the anti-oxidation performance of the oil product.

[0028] In the above embodiment, preferably, the methacrylate includes methyl methacrylate, ethyl methacrylate, butyl methacrylate, isooctyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, eicosyl methacrylate, docosyl methacrylate, N,N-dimethylacrylamide, N,N-methylenebisacrylamide, 2-(diethylamino)ethyl methacrylate, 2-(tert-butylamino)ethyl methacrylate and 2-(isopropylamino)ethyl methacrylate.

[0029] In the above embodiment, preferably, the chain transfer agent is mercaptoethanol, 2-ethylhexyl thioglycolate, 3-butyl mercaptopropionate, 3-mercaptopropyl isooctyl ester, 2-mercaptopropyl acetate isooctyl ester, n-dodecyl mercaptan, tert-dodecyl mercaptan or 2,4-diphenyl-4-methyl-1-pentene.

[0030] In the above embodiment, preferably, the chain transfer agent is 2,4-diphenyl-4-methyl-1-pentene.

[0031] In the above embodiment, preferably, the initiator is azobisisobutyronitrile, benzoyl peroxide, tert-butyl benzoyl peroxide or tert-butyl peroxy-2-ethylhexanoate.

[0032] In the above embodiment, preferably, the initiator is tert-butyl peroxy-2-ethylhexanoate.

[0033] In the above embodiment, preferably, the diluent oil is a combination of one or more of ester oil, synthetic base oil and hydrogenated base oil.

[0034] In the above embodiment, preferably, the diluent oil accounts for 30% to 40% in the reaction system.

[0035] In the above embodiment, preferably, the reaction temperature of the copolymerization reaction is 95 to 125°C.

[0036] In the above embodiment, preferably, the reaction time of the copolymerization reaction is 3 to 6 hours.

[0037] According to the method for preparing the viscosity index improver of automatic transmission oil disclosed in the above embodiment, during the implementation, the process and effect of the method are explained through the following examples and comparative examples.

[0038] Example 1: Preparation of a dispersed automatic transmission oil viscosity index improver

[0039] In a 3000ml three-necked glass bottle, add 325g of dodecyl methacrylate, 175g of tetradecyl methacrylate, 250g of isooctyl methacrylate, 200g of ethyl methacrylate, 30g of hexadecyl methacrylate, 20g of 2-(isopropylamino)ethyl methacrylate, 10g232g150N base oil, 2.0g of 2,4-diphenyl-4-methyl-1-pentene, and 2g of tert-butyl peroxy-2-ethylhexanoate, which is 1 / 3 of the total mass of the mixed solution, heat to 95°C, add the remaining 2 / 3 of the mixed solution dropwise, add dropwise for 3h, continue to keep warm for 0.5h, and then terminate the reaction.

[0040] Example 2: Preparation of a dispersed automatic transmission oil viscosity index improver

[0041] In a 3000ml three-necked glass bottle, add 525g of dodecyl methacrylate, 175g of tetradecyl methacrylate, 15g of 2-(diethylamino)ethyl methacrylate, 10g of methyl methacrylate, 1.5g of hexadecyl methacrylate, 4.5g of octadecyl methacrylate, 432g of ester oil ES602, 1.5g of 2,4-diphenyl-4-methyl-1-pentene, and 2g of tert-butyl peroxy-2-ethylhexanoate, which is 1 / 3 of the total mass of the mixed solution, heat to 95°C, add the remaining 2 / 3 of the mixed solution dropwise, add dropwise for 3h, continue to keep warm for 0.5h, and then terminate the reaction.

[0042] Example 3: Preparation of a dispersed automatic transmission oil viscosity index improver

[0043] In a 3000ml three-necked glass bottle, add 525g of dodecyl methacrylate, 175g of tetradecyl methacrylate, 30g of 2-(diethylamino)ethyl methacrylate, 10g of methyl methacrylate, 1.5g of hexadecyl methacrylate, 4.5g of octadecyl methacrylate, 432g of ester oil ES602, 2.0g of 2,4-diphenyl-4-methyl-1-pentene, and 2g of tert-butyl peroxy-2-ethylhexanoate, which account for 1 / 5 of the total mass of the mixed solution, heat to 95°C, add the remaining 4 / 5 of the mixed solution dropwise, add dropwise for 3h, continue to keep warm for 0.5h, and then terminate the reaction.

[0044] Comparative Example 1:

[0045] In a 3000ml three-necked glass bottle, add 525g of dodecyl methacrylate, 175g of tetradecyl methacrylate, 25g of methyl methacrylate, 1.5g of hexadecyl methacrylate, 4.5g of octadecyl methacrylate, 432g150N, 6.0g of tert-dodecyl mercaptan, and 2g of benzoyl peroxide, which is 1 / 3 of the total mass of the mixed solution, heat to 95°C, add the remaining 2 / 3 of the mixed solution dropwise, add dropwise for 3h, continue to keep warm for 0.5h, and then terminate the reaction.

[0046] Comparative Example 2:

[0047] In a 3000ml three-necked glass bottle, add 567.6g of base oil, stir and heat to 105°C, add 726g of dodecyl methacrylate, 221.4g of tetradecyl methacrylate, 121.8g of hexadecyl methacrylate, 132.6g of octadecyl methacrylate, 6.0g of tert-butyl peroxy-2-ethylhexanoate, and 6.0g of 2,4-diphenyl-4-methyl-1-pentene, which is 20% by weight of the mixed solution, react at constant temperature for 1h, continue to drop the remaining 80% of the mixed solution, the dropping time is 2h, and the reaction is kept at 105°C for 3h to terminate the reaction.

[0048] The performance comparison of Examples 1-3 and Comparative Examples 1-2 is shown in Table 1 below.

[0049] Table 1 Performance comparison of examples and comparative examples

[0050]

[0051] Automatic transmission oil was prepared using the viscosity modifiers of Examples 1-3 and Comparative Examples 1-2. Specific test results are shown in Table 2 below.

[0052] Table 2 Performance comparison of the embodiments and the comparative examples in the automatic transmission oil formulation

[0053]

[0054] Compared with Comparative Example 1-2, Example 1-3 adds a dispersed polar monomer. Through DKA oxidation comparative analysis, it can be seen that the polymer with a dispersed polar monomer has excellent effects on the dispersion ability of sludge and the control of viscosity growth after oxidation.

[0055] The difference between Example 2 and Example 3 is that the amount of dispersed monomer added is different. From the analysis of the results after DKA oxidation, it can be seen that the more the amount of dispersed oxidation monomer added, the better the inhibitory effect on the viscosity increase and acid value after oxidation.

[0056] Compared with Comparative Example 1, Comparative Example 2 does not contain C1-C2 ester in the polymer composition. Under the condition of the same molecular weight, the polymer has poor thickening performance and poor ability to improve the viscosity index.

[0057] Through the above analysis, it can be seen that the preparation method and application method of the viscosity modifier of the automatic transmission oil of the present invention are simple to operate, easy to implement in the process, no waste water and waste residue, etc., high in recovery rate, and have excellent low temperature performance, viscosity-temperature performance and excellent shear stability in the automatic transmission oil, which helps to disperse the sludge while improving the antioxidant performance of the oil.

[0058] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a viscosity index improver for automatic transmission oil, characterized in that: include: Using acrylic acid esters or methacrylic acid esters with different carbon chain lengths as monomer esters, wherein C1-C2 methacrylic acid esters account for 1%-10% of the total mass of the monomer esters, C4-C22 methacrylic acid esters account for 3%-80% of the total mass of the monomer esters, and methacrylamide or amino methacrylate accounts for 1%-10% of the total mass of the monomer esters; The diluent oil, the monomer ester, the chain transfer agent and the initiator are uniformly mixed, 1 / 5 or 1 / 3 of the mixture is heated to 75-140° C., and the remaining mixture is added in batches to carry out copolymerization reaction for 2-8 hours, and the reaction product is used as a viscosity index improver for automatic transmission oil; The amount of the chain transfer agent added is 0.5% to 2% of the total amount of the monomer ester, the amount of the initiator added is 0.5% to 2% of the total amount of the monomer ester, and the diluent oil accounts for 10% to 60% in the reaction system.

2. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The methacrylates include methyl methacrylate, ethyl methacrylate, butyl methacrylate, isooctyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, eicosyl methacrylate, behenyl methacrylate, N,N-dimethylacrylamide, N,N-methylenebisacrylamide, 2-(diethylamino)ethyl methacrylate, 2-(tert-butylamino)ethyl methacrylate and 2-(isopropylamino)ethyl methacrylate.

3. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The chain transfer agent is mercaptoethanol, 2-ethylhexyl mercaptoacetate, 3-butyl mercaptopropionate, 3-mercaptopropyl isooctyl ester, 2-mercaptopropyl acetate isooctyl ester, n-dodecyl mercaptan, tert-dodecyl mercaptan or 2,4-diphenyl-4-methyl-1-pentene.

4. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The chain transfer agent is 2,4-diphenyl-4-methyl-1-pentene.

5. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The initiator is azobisisobutyronitrile, benzoyl peroxide, tert-butyl benzoyl peroxide or tert-butyl peroxide-2-ethylhexanoate.

6. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The initiator is tert-butyl peroxy-2-ethylhexanoate.

7. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The diluent oil is a combination of one or more of ester oil, synthetic base oil and hydrogenated base oil.

8. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The diluent oil accounts for 30% to 40% in the reaction system.

9. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The reaction temperature of the copolymerization reaction is 95-125°C.

10. The method for preparing a viscosity index improver for automatic transmission oil according to claim 1, characterized in that: The reaction time of the copolymerization reaction is 3 to 6 hours.

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