A thickened hydraulic oil composition and a preparation method thereof

Abstract

The present invention proposes a thickened hydraulic oil composition comprising the following components, by weight: 5-8% viscosity index improver, 0.5-3% extreme pressure antiwear agent, 0.1-3% antioxidant, 0.05-0.3% rust inhibitor, 0.01-0.1% passivator, 0.001-0.03% antifoaming agent, with the balance being base oil. This thickened hydraulic oil composition, obtained by combining a polymethacrylate viscosity index improver with an extreme pressure antiwear agent, exhibits excellent viscosity-temperature performance and low-temperature starting performance, as well as superior extreme pressure and antiwear properties, ensuring smooth equipment operation.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating oils, and in particular relates to a thickened hydraulic oil composition and a preparation method thereof. Background Art

[0002] When hydraulic equipment works in extremely cold or high temperature conditions, higher requirements are placed on the low-temperature fluidity and viscosity-temperature performance of the oil.

[0003] Patent CN107760418A discloses an ashless anti-wear hydraulic lubricant composition and its preparation method. This composition primarily improves the service life of the hydraulic oil by balancing the combination of an extreme pressure anti-wear agent and an antioxidant. The composition comprises the following components by weight: 0.1-5.0% extreme pressure anti-wear agent, 0.05-2.00% antioxidant, 0.01-0.5% metal deactivator, 0.05-0.1% rust inhibitor, 0.03-0.06% demulsifier, 0.001-0.01% anti-foaming agent, 0.2-6.5% viscosity index improver, and 92.0-98.6% base oil. The extreme pressure anti-wear agent is isobutylene sulfide, di-n-butyl phosphite, tricresyl phosphate, or thiophosphates and their amine salt derivatives, or phosphates and their amine salt derivatives, or any combination thereof.

[0004] Patent CN102925263A discloses an ultra-high viscosity index anti-wear hydraulic oil and its preparation method. The oil is prepared by adding 5-30% diester base oil and a viscosity index improver, resulting in a viscosity index greater than 250 and a pour point below -50°C. The oil comprises the following components by weight: 37.7-89.8% hydroisomerized base oil, 5-30% diester base oil, 5-30% viscosity index improver, 0.2-2% ashless anti-wear hydraulic oil additive package, 0.02-0.2% anti-wear extreme pressure agent, and 0.01-0.1% metal deactivator. However, this method is costly and not universally applicable.

[0005] Therefore, there is an urgent need for a viscosity index improver that can simultaneously increase the viscosity index of oil products, lower the pour point of oil products, and have good shear resistance, as well as a formula that can be well compounded with an extreme pressure anti-wear agent. Summary of the Invention

[0006] In order to solve the above problems in the prior art, the present invention proposes a thickened hydraulic oil composition and a preparation method thereof. The composition of the present invention not only significantly improves the viscosity index and reduces the pour point, but also has a synergistic effect when compounded with an extreme pressure anti-wear agent.

[0007] In a first aspect, the present invention provides a thickened hydraulic oil composition, which comprises, by weight percentage:

[0008]

[0009] As a specific embodiment of the present invention, the base oil is a mixture of HVI I and HVI II base oils; the mixing mass ratio of the HVI I base oil to the HVI II base oil is (1-30): (70-99), preferably (15-30): (70-85).

[0010] In a specific embodiment of the present invention, the viscosity index improver is a polymethacrylate having a molecular weight distribution index (RI) of 1-2, a molecular weight of less than 30,000 Daltons, and an average carbon number of C12-C14. Preferably, the polymethacrylate includes BD45310, SCR178A, and TF6-310. This improves the viscosity index of the oil and lowers the pour point.

[0011] As a specific embodiment of the present invention, the extreme pressure anti-wear agent is selected from at least one of dialkyl zinc dithiophosphate, phosphate, thiophosphate and ammonium salt derivatives thereof.

[0012] As a specific embodiment of the present invention, the extreme pressure anti-wear agent is selected from at least one of T203, T306, T309, QT-302, Irgalube353, and IrgalubeTPPT.

[0013] It should be noted that the viscosity index improver has two effects on the lubrication performance of the extreme pressure agent. On the one hand, the thickening substance in the viscosity index improver can form a network structure, which can evenly distribute the extreme pressure anti-wear agent in the oil. On the other hand, the thickening substance in the viscosity index improver can also rely on its own adsorption capacity to adsorb the extreme pressure anti-wear agent on the friction surface, thereby enhancing the lubrication performance.

[0014] As a specific embodiment of the present invention, the antioxidant is selected from one of 2,6-di-tert-butyl-p-cresol, N-phenyl-a-naphthylamine or alkyl diphenylamine.

[0015] As a specific embodiment of the present invention, the rust inhibitor is one of calcium dinonylnaphthalenesulfonate or barium dinonylnaphthalenesulfonate.

[0016] As a specific embodiment of the present invention, the passivating agent is selected from one of benzotriazole, thiadiazole and derivatives thereof; preferably, it is the thiadiazole derivative T561.

[0017] As a specific embodiment of the present invention, the antifoaming agent is a silicon-type antifoaming agent and / or a non-silicon-type antifoaming agent.

[0018] In a second aspect, the present invention provides a method for preparing a thickened hydraulic oil composition, comprising the steps of uniformly mixing a viscosity index improver, an extreme pressure anti-wear agent, an antioxidant, a rust inhibitor, a passivator, an anti-foaming agent and a base oil, and filtering to obtain the thickened hydraulic oil composition.

[0019] As a specific embodiment of the present invention, the mixing method is stirring while heating to 50-60° C.; the stirring rate is 400-500 rpm, and the stirring time is 1 h to 2 h.

[0020] The above raw materials in the present invention can be prepared in-house or purchased commercially, and the present invention is not particularly limited thereto.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The thickened hydraulic oil composition of the present invention is obtained by compounding a polymethacrylate viscosity index improver having both viscosity-increasing and pour point-depressing effects and having a molecular weight distribution index (RI) of 1 to 2, a molecular weight of less than 30,000 Daltons, and an average carbon number of C12 to C14 with an extreme pressure anti-wear agent. The thickened hydraulic oil composition not only maintains good viscosity-temperature performance and low-temperature starting performance, but also has good extreme pressure and anti-wear properties, ensuring smooth operation of equipment under severe cold or high temperature conditions.

[0023] 2. The thickened hydraulic oil composition of the present invention can improve the viscosity index by adding 5-8% of a viscosity index improver. Compared with the prior art, the viscosity index of the composition of the present invention is improved by 44-58%; and it can also reduce the pour point by 21-27°C compared with the prior art.

[0024] 3. The thickened hydraulic oil composition of the present invention has good economic benefits and universal applicability. Compared with single-grade oil of the same viscosity grade, it can reduce oil consumption by 27% and reduce fuel consumption by 3-5%. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to specific examples, but they do not constitute any limitation to the present invention.

[0026] In each embodiment of the present invention, the specific information of the reagents used is as follows:

[0027] Viscosity index improver: polymethacrylate BD45310, molecular weight distribution index RI is 1 to 2;

[0028] Polymethacrylate SCR178A, molecular weight distribution index RI is 1 to 2;

[0029] Polymethacrylate TF6-310, molecular weight distribution index RI is 1 to 2;

[0030] Polymethacrylate T602HD-2, molecular weight distribution index RI greater than 3.

[0031] Example 1

[0032] This embodiment provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0033] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0034] Viscosity index improver: 7 parts polymethacrylate BD45310;

[0035] Extreme pressure and anti-wear agent: 0.6 parts of zinc dialkyl dithiophosphate T203 and 0.6 parts of tricresyl phosphate T306;

[0036] Antioxidant: 0.5 parts of 2,6-di-tert-butyl-p-cresol;

[0037] Rust inhibitor: 0.1 part of calcium dinonylnaphthalenesulfonate T705C;

[0038] Passivating agent: 0.01 parts of thiadiazole derivative T561;

[0039] Antifoaming agent: 0.01 Chongqing 1# composite antifoaming agent;

[0040] Base oil: 20 parts HVI Group I and 71.18 parts HVI Group II hydrogenated blended base oil.

[0041] The preparation method of the extreme pressure turbine oil composition of this embodiment is as follows:

[0042] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0043] Example 2

[0044] This embodiment provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0045] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0046] Viscosity index improver: 6 parts polymethacrylate BD45310;

[0047] Extreme pressure anti-wear agent: 0.8 parts of zinc dialkyl dithiophosphate T203 and 0.8 parts of tricresyl phosphate T306;

[0048] Antioxidant: 0.6 parts of 2,6-di-tert-butyl-p-cresol;

[0049] Rust inhibitor: 0.05 parts of calcium dinonylnaphthalenesulfonate T705C;

[0050] Passivating agent: 0.015 parts of thiadiazole derivative T561;

[0051] Antifoaming agent: 0.015 Chongqing 1# composite antifoaming agent;

[0052] Base oil: 20 parts HVI Group I and 71.72 parts HVI Group II hydrogenated blended base oil.

[0053] The preparation method of the extreme pressure turbine oil composition of this embodiment is as follows:

[0054] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0055] Example 3

[0056] This embodiment provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0057] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0058] Viscosity index improver: 6.5 parts of polymethacrylate BD45310;

[0059] Extreme pressure and anti-wear agent: 0.6 parts of zinc dialkyl dithiophosphate T203 and 0.6 parts of tricresyl phosphate T306;

[0060] Antioxidant: 0.5 parts of 2,6-di-tert-butyl-p-cresol;

[0061] Rust inhibitor: 0.1 part of calcium dinonylnaphthalenesulfonate T705C;

[0062] Passivating agent: 0.01 parts of thiadiazole derivative T561;

[0063] Antifoaming agent: 0.01 Chongqing 1# composite antifoaming agent;

[0064] Base oil: 20 parts HVI Group I and 71.68 parts HVI Group II hydrogenated blended base oil.

[0065] The preparation method of the extreme pressure turbine oil composition of this embodiment is as follows:

[0066] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0067] Example 4

[0068] This embodiment provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0069] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0070] Viscosity index improver: 7 parts polymethacrylate SCR178A;

[0071] Extreme pressure anti-wear agent: 0.1 parts of alkyl thiophosphate Irgalube353;

[0072] Antioxidant: 0.5 parts of 2,6-di-tert-butyl-p-cresol;

[0073] Rust inhibitor: 0.1 part of calcium dinonylnaphthalenesulfonate T705C;

[0074] Passivating agent: 0.015 parts of thiadiazole derivative T561;

[0075] Antifoaming agent: 0.015 Chongqing 1# composite antifoaming agent;

[0076] Base oil: 25 parts HVI Group I and 67.27 parts HVI Group II hydrogenated blended base oil.

[0077] The preparation method of the extreme pressure turbine oil composition of this embodiment is as follows:

[0078] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0079] Example 5

[0080] This embodiment provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0081] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0082] Viscosity index improver: 8 parts polymethacrylate SCR178A;

[0083] Extreme pressure and anti-wear agent: 0.8 parts of zinc dialkyl dithiophosphate T203 and 0.8 parts of triphenyl thiophosphate T309;

[0084] Antioxidant: 0.6 parts of 2,6-di-tert-butyl-p-cresol;

[0085] Rust inhibitor: 0.05 parts of calcium dinonylnaphthalenesulfonate T705C;

[0086] Passivating agent: 0.015 parts of thiadiazole derivative T561;

[0087] Antifoaming agent: 0.015 Chongqing 1# composite antifoaming agent;

[0088] Base oil: 20 parts HVI Group I and 69.72 parts HVI Group II hydrogenated blended base oil.

[0089] The preparation method of the extreme pressure turbine oil composition of this embodiment is as follows:

[0090] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0091] Example 6

[0092] This embodiment provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0093] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0094] Viscosity index improver: 5 parts polymethacrylate TF6-310;

[0095] Extreme pressure anti-wear agent: 1 part zinc dialkyl dithiophosphate T203 and 0.8 part triphenyl thiophosphate T309;

[0096] Antioxidant: 0.6 parts of 2,6-di-tert-butyl-p-cresol;

[0097] Rust inhibitor: 0.05 parts of calcium dinonylnaphthalenesulfonate T705C;

[0098] Passivating agent: 0.015 parts of thiadiazole derivative T561;

[0099] Antifoaming agent: 0.015 Chongqing 1# composite antifoaming agent;

[0100] Base oil: 15 parts HVI Group I and 77.52 parts HVI Group II hydrogenated blended base oil.

[0101] The preparation method of the extreme pressure turbine oil composition of this embodiment is as follows:

[0102] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0103] Comparative Example 1

[0104] This comparative example provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0105] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0106] Viscosity index improver: 7 parts polymethacrylate T602HD-2;

[0107] Extreme pressure and anti-wear agent: 0.6 parts of zinc dialkyl dithiophosphate T203 and 0.6 parts of tricresyl phosphate T306;

[0108] Antioxidant: 0.5 parts of 2,6-di-tert-butyl-p-cresol;

[0109] Rust inhibitor: 0.1 part of calcium dinonylnaphthalenesulfonate T705C;

[0110] Passivating agent: 0.01 parts of thiadiazole derivative T561;

[0111] Antifoaming agent: 0.01 Chongqing 1# composite antifoaming agent;

[0112] Base oil: 20 parts HVI Group I and 71.18 parts HVI Group II hydrogenated blended base oil.

[0113] The preparation method of the thickened hydraulic oil composition of this comparative example is as follows:

[0114] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0115] Comparative Example 2

[0116] This comparative example provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0117] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0118] Viscosity index improver: 9 parts polymethacrylate T602HD-2;

[0119] Extreme pressure anti-wear agent: 0.8 parts of zinc dialkyl dithiophosphate T203 and 0.8 parts of tricresyl phosphate T306;

[0120] Antioxidant: 0.6 parts of 2,6-di-tert-butyl-p-cresol;

[0121] Rust inhibitor: 0.05 parts of calcium dinonylnaphthalenesulfonate T705C;

[0122] Passivating agent: 0.015 parts of thiadiazole derivative T561;

[0123] Antifoaming agent: 0.015 Chongqing 1# composite antifoaming agent;

[0124] Base oil: 20 parts HVI Group I and 68.72 parts HVI Group II hydrogenated blended base oil.

[0125] The preparation method of the extreme pressure turbine oil composition of this comparative example is as follows:

[0126] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0127] Comparative Example 3

[0128] This comparative example provides a thickened hydraulic oil composition and a preparation method thereof, the specific details of which are as follows:

[0129] The thickened hydraulic oil composition is composed of the following components in parts by weight:

[0130] Viscosity index improver: 4 parts polymethacrylate SCR-178A;

[0131] Extreme pressure and anti-wear agent: 0.8 parts of zinc dialkyl dithiophosphate T203 and 0.8 parts of triphenyl thiophosphate T309;

[0132] Antioxidant: 0.5 parts of 2,6-di-tert-butyl-p-cresol;

[0133] Rust inhibitor: 0.1 part of calcium dinonylnaphthalenesulfonate T705C;

[0134] Passivating agent: 0.015 parts of thiadiazole derivative T561;

[0135] Antifoaming agent: 0.015 Chongqing 1# composite antifoaming agent;

[0136] Base oil: 25 parts HVI Group I and 68.77 parts HVI Group II hydrogenated blended base oil.

[0137] The preparation method of the extreme pressure turbine oil composition of this comparative example is as follows:

[0138] The viscosity index improver, extreme pressure anti-wear agent, antioxidant, rust inhibitor, passivator, anti-foaming agent and base oil are uniformly mixed, and the mixture is heated to 55° C. and heated with stirring for 2 hours and then filtered to obtain the thickened hydraulic oil composition.

[0139] The performance of Examples 1 to 6 and Comparative Examples 1 to 3 was evaluated and tested using the following test methods: lubricating oil kinematic viscosity determination method (GB / T 265), lubricating oil viscosity index determination method (GB / T 1995), lubricating oil pour point determination method (GB / T 3535), petroleum product liquid phase rust test (GB / T 11143B), foam characteristic determination method (GB / T 12579), wear spot diameter test method (NB / SH / T 0189), rotating oxygen bomb determination method (SH / T 0193), and shear stability test (40°C kinematic viscosity reduction rate) test method (NB / SH / T 0505). The results of viscosity-temperature performance, low-temperature fluidity, extreme pressure anti-wear properties, rust prevention performance, anti-foaming performance, oxidation stability, and shear stability of Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 1.

[0140] Table 1 Test results of the examples and comparative examples

[0141]

[0142] As can be seen from Table 1, the viscosity index of the thickened hydraulic oil compositions prepared in Examples 1 to 6 is 165 or above, indicating that the products have good viscosity-temperature performance, wherein the optimized dosage of the viscosity index improver is 7-8%; the pour points of the thickened hydraulic oil compositions prepared in Examples 1 to 6 are all -36°C or below, indicating that the products have good low-temperature flow properties; the anti-rust performance, wear spot diameter, anti-foaming performance, shear stability and other results of the thickened hydraulic oil compositions prepared in Examples 1 to 6 are all good, indicating that the oil products have good corrosion resistance, extreme pressure and anti-wear performance, anti-foaming performance and shear stability; the thickened hydraulic oil compositions prepared in Examples 1 to 6 are The viscosity index and low-temperature fluidity of the composition are significantly improved, and the composition has good economic efficiency in use. The molecular weight distribution index of the polymethacrylate T602HD-2 selected in Comparative Example 2 is greater than 3, and the viscosity index effect is poor. The dosage of the viscosity index improver in Comparative Examples 1 and 3 is either too much or too little. The thickened hydraulic oil compositions prepared in Comparative Examples 1 to 3 cannot take into account both the viscosity-temperature performance and low-temperature fluidity of the oil product due to improper selection of the molecular weight or dosage of the viscosity index improver. The thickened hydraulic oil composition of the present invention has better viscosity-temperature performance, low-temperature fluidity and extreme pressure and anti-wear properties than the thickened hydraulic oil compositions prepared in Comparative Examples 1 to 3.

[0143] In summary, the thickened hydraulic oil composition of the present invention, obtained by compounding an extreme pressure and anti-wear agent with a polymethacrylate viscosity index improver having both viscosity-increasing and pour point-depressing effects, not only has good viscosity-temperature performance and low-temperature starting performance, but also has good extreme pressure and anti-wear properties, thereby ensuring the smooth operation of equipment.

[0144] Any numerical value mentioned in the present invention includes all values that increase by one unit each time from the lowest value to the highest value if there is only a gap of two units between any minimum value and any maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, time, etc. is stated to be 50-90, it is meant in this specification to specifically list values such as 51-89, 52-88... and 69-71 and 70-71. For non-integer values, it is appropriate to consider units of 0.1, 0.01, 0.001 or 0.0001. These are just some special examples. In this application, in a similar manner, all possible combinations of numerical values between the listed lowest value and the listed highest value are considered to have been disclosed.

[0145] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation of the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A thickened hydraulic oil composition, characterized in that: In terms of weight percentage, its components include: Viscosity index improver 5~8%, Extreme pressure anti-wear agent 0.5~3%, Antioxidant 0.1~3%, Rust inhibitor 0.05~0.3%, Passivation agent 0.01~0.1%, Antifoaming agent 0.001~0.03%, The balance is base oil; The viscosity index improver is polymethacrylate BD45310, SCR178A or TF6-310 having a molecular weight distribution index RI of 1 to 2, a molecular weight of less than 30,000 Daltons, and an average carbon number of C12 to C14; The extreme pressure anti-wear agent is selected from at least one of thiophosphates and their ammonium salt derivatives, zinc dialkyl dithiophosphates, and tricresyl phosphate; The antioxidant is selected from one of 2,6-di-tert-butyl-p-cresol, N-phenyl-a-naphthylamine or alkyl diphenylamine; The rust inhibitor is one of calcium dinonylnaphthalenesulfonate or barium dinonylnaphthalenesulfonate; The passivating agent is a thiadiazole derivative T561; The base oil is a mixture of HVI Class I base oil and HVI Class II base oil; The mass ratio of the HVI Class I base oil to the HVI Class II base oil is (1-30):(70-99); The antifoaming agent is a silicon-based antifoaming agent and / or a non-silicon-based antifoaming agent.

2. The thickened hydraulic oil composition according to claim 1, characterized in that: The mass ratio of the HVI Class I base oil to the HVI Class II base oil is (10-30):(70-90).

3. A method for preparing the thickened hydraulic oil composition according to claim 1 or 2, comprising the steps of: uniformly mixing a viscosity index improver, an extreme pressure anti-wear agent, an antioxidant, a rust inhibitor, a passivator, an anti-foaming agent and a base oil, and filtering to obtain the thickened hydraulic oil composition.

4. The preparation method according to claim 3, characterized in that The mixing method is heating and stirring, heating to 50-60°C; the stirring rate is 400-500 rpm, and the stirring time is 1h-2h.

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