Compound barium base lubricating grease for RV reducer and preparation method thereof

Abstract

The present application relates to lubricating grease, and specifically discloses a composite barium base lubricating grease for RV reducer and a preparation method thereof.The composite barium base lubricating grease comprises, by weight, 75-89% of base oil, 6-12% of composite barium base thickener and 0.1-8% of additive.The composite barium base lubricating grease has excellent oxidation stability, extreme pressure and wear resistance, high and low temperature performance and water resistance, is a multi-effect lubricating grease, can effectively improve the anti-fretting wear and impact load resistance of the RV reducer and the precision bearing used thereby, and ensures that the equipment can be normally started and operated at a lower temperature, and has a very wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to a grease, in particular to a high-performance composite barium-based grease suitable for RV reducers and precision bearings used therein and a preparation method thereof. BACKGROUND

[0002] In recent years, industrial robot technology has developed rapidly. As the main component of industrial robots, the performance, precision and reliability of RV (Rotary-Vector) reducers and precision bearings used therein have attracted more and more attention. At the same time, with the gradually harsh conditions for the use of modern precision bearings, new challenges have been put forward for the research and development of high-performance greases, mainly in the aspects of high and low temperature performance, water resistance, extreme pressure and wear resistance, oxidation stability, and colloid stability.

[0003] Barium-based grease has excellent shear resistance, extreme pressure resistance and protection performance, and is not soluble in gasoline and alcohol, so it is a good lubricant and protective sealing material. However, the dropping point of barium-based grease is not high, so its application range is very limited. Composite barium-based grease is prepared by reacting two or more acids with barium hydroxide to form a composite barium soap thickened base oil. Compared with barium-based grease, the dropping point is improved, and the chemical thermal stability is higher. In addition, the composite barium-based grease also has long service life, water resistance, extreme pressure resistance, wear resistance and other characteristics, and is widely used in precision machinery, textile printing and dyeing, ships and other fields, and has broad development prospects.

[0004] At present, although there are some methods for preparing composite barium-based grease, there is no high-performance composite barium-based grease suitable for RV reducers and precision bearings used therein. CN 102703179A introduces a kind of grease for high-speed full-steel angular contact bearing and its preparation method. The composite barium-based grease is used as the basis, and the heat conducting agent, i.e. nano particles, is added, so that it has higher speed coefficient and better heat conducting performance. CN 113150858 A uses 12-hydroxy stearic acid, small molecule organic acid, mineral base oil, synthetic base oil, barium hydroxide as raw materials, and adds tungsten disulfide powder, and finally obtains composite barium-based grease. Although the composite barium-based grease involved in the above patents improves the wear resistance and heat conductivity to some extent, in order to meet the special working condition requirements of RV reducers and precision bearings used therein, the oxidation stability, anti-friction and wear resistance, and low temperature performance of the composite barium-based grease still have room for further optimization, so it is necessary to study a high-performance composite barium-based grease suitable for RV reducers and precision bearings used therein. SUMMARY

[0005] The application provides a high-performance composite barium base grease suitable for RV reducers and precision bearings used thereby and a preparation method thereof.

[0006] The composite barium base grease comprises the following components by weight of the composite barium base grease: 75-89% of base oil, 6-12% of composite barium base thickener and 0.1-8% of additive.

[0007] According to the embodiment of the application, the composite barium base grease comprises the following components by weight of the composite barium base grease: 80-86% of base oil, 7-10% of composite barium base thickener and 0.1-8% of additive.

[0008] According to the preferred embodiment of the application, the weight ratio of the cycloalkyl mineral oil, alkyl naphthalene and poly-alpha olefin synthetic oil in the base oil is (16-20):(28-35):(16-22).

[0009] According to the preferred embodiment of the application, the weight ratio of the cycloalkyl mineral oil, alkyl naphthalene and poly-alpha olefin synthetic oil in the base oil is 18:31:19.

[0010] According to the embodiment of the application, the 100℃ kinematic viscosity of the base oil is 5-60mm 2 / s.

[0011] According to the embodiment of the application, the base oil is supplemented to 100% of the total weight of the composite barium base grease.

[0012] The application finds that the use of the mixed oil composed of cycloalkyl mineral oil, alkyl naphthalene and poly-alpha olefin synthetic oil as the base oil can make the grease have better low-temperature performance, ensure the normal lubrication of the RV reducer and the precision bearings used thereby at low temperature; in addition, the oxidation stability of the grease is improved, and the anti-wear performance of the grease is effectively improved, the friction is reduced, the performance and operation efficiency of the equipment are improved, and the service life of the equipment is prolonged.

[0013] According to the embodiment of the application, the composite barium base thickener is generated by the reaction of acid and barium hydroxide.

[0014] According to the embodiment of the application, the acid is a mixed acid of high fatty acid and small molecule acid, and the weight ratio of the two is preferably 1:(0.1-0.8), for example, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7 or 1:0.8.

[0015] According to the embodiment of the present application, the higher fatty acid is selected from C12-C24 fatty acids; and the small molecule acid is selected from C4-C12 carboxylic acids.

[0016] According to the embodiment of the present application, the higher fatty acid is one or more of 12-hydroxystearic acid, stearic acid, lauric acid, and palmitic acid; and the small molecule acid is one or more of malic acid, succinic acid, citric acid, and terephthalic acid.

[0017] According to the embodiment of the present application, the composite barium-based thickening agent is generated by reacting the acid with barium hydroxide in a weight ratio of (0.8-1.2):1.

[0018] According to the specific embodiment of the present application, the composite barium-based thickening agent is generated by reacting lauric acid and terephthalic acid with barium hydroxide; wherein the weight ratio of lauric acid to terephthalic acid is 1:0.6; and the weight ratio of the sum of lauric acid and terephthalic acid to barium hydroxide is 1.1:1.

[0019] According to the specific embodiment of the present application, the composite barium-based thickening agent is generated by reacting stearic acid and malic acid with barium hydroxide; wherein the weight ratio of stearic acid to malic acid is 1:0.2; and the weight ratio of the sum of stearic acid and malic acid to barium hydroxide is 0.8:1.

[0020] It is found that the use of the composite barium-based thickening agent of the present application can make the final prepared grease have more excellent oxidation stability, colloid stability, and extreme pressure and wear resistance, and improve the performance of the grease product in all aspects.

[0021] According to the embodiment of the present application, the additive comprises one or more of an antioxidant, an extreme pressure and wear resistant agent, and a rust preventive.

[0022] According to the embodiment of the present application, the antioxidant comprises at least one of an amine antioxidant and a phenolic antioxidant.

[0023] Preferably, the amine antioxidant is selected from one or two of diphenylamine, naphthylamine, and p-phenylenediamine; and the phenolic antioxidant is selected from one or two of 2,6-di-tert-butyl-p-cresol and α-naphthol.

[0024] According to the embodiment of the present application, the content of the antioxidant is 0.6-3%, or 1-2%, based on the weight of the composite barium-based grease.

[0025] According to the embodiment of the present application, the extreme pressure and wear resistant agent is selected from one or more of zinc dialkyldithiophosphate, molybdenum dithio-dialkylcarbamate, phosphate ester, and borate ester.

[0026] According to the embodiment of the present application, the content of the extreme pressure and wear resistant agent is 1-7%, or 3-6%, based on the weight of the composite barium-based grease.

[0027] According to the embodiment of the present application, the rust inhibitor is selected from one or more of petroleum barium sulfonate, benzothiazole, alkenyl succinic acid, and zinc naphthenate.

[0028] According to the embodiment of the present application, the content of the rust inhibitor is 0.1-2% by weight of the composite barium-based grease, and can be 0.1-0.9%.

[0029] It is found through research that, by using the above-mentioned antioxidants and extreme pressure anti-wear agents, the oxidation resistance and wear resistance of the grease are greatly improved, while the other properties of the composite barium-based grease are not greatly affected, so that the grease still has excellent high-temperature resistance, colloid stability, water resistance, etc., and the grease provided by the present application can still exhibit good lubricating properties under harsh working conditions such as high temperature, high load, and high water content.

[0030] The present application also provides a preparation method of the above-mentioned composite barium-based grease, which comprises the following steps: mixing a higher fatty acid, a small molecule acid, and an appropriate amount of base oil (for example, 30-75% of the total weight of the base oil), heating to 75-90°C, fully stirring, adding barium hydroxide, and heating to 90-120°C to perform saponification reaction; after the reaction is complete, heating to 180-220°C to perform refining, and keeping the temperature constant for 7-12 min; adding an appropriate amount of base oil (for example, 10-25% of the total weight of the base oil) to rapidly cool and reduce the temperature, reducing the temperature to 140-170°C, adding the remaining base oil and antioxidants; continuing to reduce the temperature to below 110°C, adding extreme pressure anti-wear agents and rust inhibitors, and stirring and post-treating to obtain the finished product.

[0031] According to the embodiment of the present application, the preparation method of the composite barium-based grease comprises the following steps: mixing a higher fatty acid, a small molecule acid, and an appropriate amount of base oil (for example, 35-72% of the total weight of the base oil), heating to 80-90°C, fully stirring, adding barium hydroxide, heating to 90-105°C, keeping the temperature constant for 30-60 min, and performing saponification reaction; after the reaction is complete, heating to 180-220°C to perform refining, and keeping the temperature constant for 7-10 min; adding an appropriate amount of base oil (for example, 15-25% of the total weight of the base oil) to rapidly cool and reduce the temperature, reducing the temperature to 150-165°C, adding the remaining base oil and antioxidants; continuing to reduce the temperature to below 110°C, adding extreme pressure anti-wear agents and rust inhibitors, and stirring and post-treating to obtain the finished product.

[0032] In the present application, the post-treatment can be dispersed grinding using a post-treatment device. After the post-treatment, the product can be filled.

[0033] The composite barium base grease provided by the application has excellent oxidation stability, extreme pressure and wear resistance, high and low temperature performance and water resistance, is a multi-effect grease, can effectively improve the anti-fretting wear and impact load resistance of RV reducers and precision bearings used thereby, and ensures that the equipment can still be normally started and operated at a lower temperature, and has a very wide application prospect.

[0034] The application also provides application of the composite barium base grease in RV reducers and precision bearings used thereby.

[0035] From the above technical solution, compared with the prior art, the application has the following beneficial effects:

[0036] (1) The composite barium base grease has good low temperature performance, and ensures that the equipment can still be normally started and operated at a lower temperature.

[0037] (2) The composite barium base grease has excellent wear resistance and low friction coefficient, and can effectively improve the fretting wear of the RV reducer and the precision bearing used thereby during operation.

[0038] (3) The composite barium base grease has good oxidation resistance, water resistance and high temperature resistance, and can still have good lubricating performance under harsh working conditions such as high water and high temperature. DETAILED DESCRIPTION

[0039] The technical solution of the application will be described clearly and completely in combination with specific examples, and the described examples are used to illustrate the application, but are not used to limit the scope of the application. If the specific technology or condition is not specified in the examples, the technology or condition described in the literature in the art or the product instruction is used. The implementation conditions in the examples can be further adjusted according to specific experimental conditions or factory conditions, and the implementation conditions not specified are usually the conditions in the conventional experiments. The materials and reagents used in the following examples are commercially available unless otherwise specified.

[0040] Example 1

[0041] The base oil in this example is a mixed oil of naphthenic mineral oil, alkyl naphthalene and poly-alpha olefin synthetic oil in a weight ratio of 18:31:19.

[0042] This example provides a composite barium base grease, and the preparation method is as follows:

[0043] 961g base oil, 87g lauric acid, 52g terephthalic acid were added into the reaction kettle, heated and stirred, and heated to 83°C. 125g of barium hydroxide octahydrate was slowly added, and the temperature was raised to 92°C to start saponification. After 60 minutes of reaction, the temperature was raised to 196°C, and the temperature was kept constant for 8 minutes. 295g of base oil was added to cool down, the temperature was lowered to 156°C, 95g of base oil was added, and 10.8g of diphenylamine and 10.8g of 2,6-di-tert-butyl-p-cresol were added. The temperature was continuously lowered to 80°C, 32.4g of molybdenum dithiodialkylcarbamate and 32.4g of borate were added, 3.9g of zinc naphthenate was added, and the mixture was stirred uniformly. After dispersion and grinding by the post-processing equipment, the finished product was packaged.

[0044] Example 2

[0045] The base oil of this example is a mixed oil of naphthenic mineral oil, alkyl naphthalene, and poly-alpha olefin synthetic oil in a weight ratio of 17:30:20.

[0046] This example provides a composite barium-based grease, and the preparation method is as follows:

[0047] 961g base oil, 87g lauric acid, 52g terephthalic acid were added into the reaction kettle, heated and stirred, and heated to 83°C. 125g of barium hydroxide octahydrate was slowly added, and the temperature was raised to 92°C to start saponification. After 60 minutes of reaction, the temperature was raised to 196°C, and the temperature was kept constant for 8 minutes. 295g of base oil was added to cool down, the temperature was lowered to 156°C, 95g of base oil was added, and 10.8g of diphenylamine and 10.8g of 2,6-di-tert-butyl-p-cresol were added. The temperature was continuously lowered to 80°C, 32.4g of molybdenum dithiodialkylcarbamate and 32.4g of borate were added, 3.9g of zinc naphthenate was added, and the mixture was stirred uniformly. After dispersion and grinding by the post-processing equipment, the finished product was packaged.

[0048] Example 3

[0049] The base oil of this example is a mixed oil of naphthenic mineral oil, alkyl naphthalene, and poly-alpha olefin synthetic oil in a weight ratio of 19:34:21.

[0050] This example provides a composite barium-based grease, and the preparation method is as follows:

[0051] 961g base oil, 87g lauric acid, 52g terephthalic acid were added into a reaction kettle, heated and stirred, and heated to 89°C. 125g of barium hydroxide octahydrate was slowly added, and the temperature was raised to 101°C to start saponification. After 60 minutes of reaction, the temperature was raised to 208°C, and the temperature was kept constant for 7 minutes. 295g of base oil was added to cool down the temperature. The temperature was lowered to 163°C, 95g of base oil was added, and 10.8g of α-naphthol and 10.8g of p-phenylenediamine were added. The temperature was continuously lowered to 75°C, 44.2g of phosphate and 21.6g of zinc dialkyldithiophosphate were added, 1.25g of barium petroleum sulfonate and 5.61g of zinc naphthenate were added, and the mixture was stirred uniformly. After dispersion and grinding by a post-processing device, the product was canned.

[0052] Example 4

[0053] The base oil of this example is a mixed oil of naphthenic mineral oil, alkyl naphthalene, and poly-α-olefin synthetic oil in a weight ratio of 18:33:17.

[0054] This example provides a composite barium-based grease, and the preparation method is as follows:

[0055] 961g base oil, 87g lauric acid, 52g terephthalic acid were added into a reaction kettle, heated and stirred, and heated to 89°C. 125g of barium hydroxide octahydrate was slowly added, and the temperature was raised to 101°C to start saponification. After 60 minutes of reaction, the temperature was raised to 208°C, and the temperature was kept constant for 7 minutes. 295g of base oil was added to cool down the temperature. The temperature was lowered to 163°C, 95g of base oil was added, and 10.8g of α-naphthol and 10.8g of p-phenylenediamine were added. The temperature was continuously lowered to 75°C, 44.2g of phosphate and 21.6g of zinc dialkyldithiophosphate were added, 1.25g of barium petroleum sulfonate and 5.61g of zinc naphthenate were added, and the mixture was stirred uniformly. After dispersion and grinding by a post-processing device, the product was canned.

[0056] Example 5

[0057] The base oil of this example is a mixed oil of naphthenic mineral oil, alkyl naphthalene, and poly-α-olefin synthetic oil in a weight ratio of 19:32:21.

[0058] This example provides a composite barium-based grease, and the preparation method is as follows:

[0059] Into a reaction kettle were added 740 g of base oil, 72 g of stearic acid, and 14 g of malic acid, heated and stirred, and then heated to 90°C. Then 103 g of barium hydroxide octahydrate was slowly added, and the temperature was raised to 100°C to start saponification. The reaction was allowed to proceed for 56 min, and then the temperature was raised to 201°C after saponification was completed. The temperature was kept constant for 7 min, and then 200 g of base oil was added to rapidly cool the temperature. The temperature was lowered to 157°C, and then 83 g of base oil was added, and 7.2 g of naphthylamine and 14.4 g of a-naphthol were added. The temperature was continuously lowered to 82°C, and then 21.6 g of borate and 44.2 g of molybdenum dithiodialkyldithiocarbamate were added. Then 1.39 g of barium petroleum sulfonate and 8.91 g of benzothiazole were added, and the mixture was stirred uniformly. After dispersion and grinding by a post-treatment device, the product was filled into a can.

[0060] Example 6

[0061] The base oil of this example is a mixture of a cycloparaffin mineral oil, an alkyl naphthalene, and a poly-alpha olefin synthetic oil in a weight ratio of 20:30:19.

[0062] This example provides a composite barium-based grease, which is prepared according to the following method:

[0063] Into a reaction kettle were added 740 g of base oil, 72 g of stearic acid, and 14 g of malic acid, heated and stirred, and then heated to 90°C. Then 103 g of barium hydroxide octahydrate was slowly added, and the temperature was raised to 100°C to start saponification. The reaction was allowed to proceed for 56 min, and then the temperature was raised to 201°C after saponification was completed. The temperature was kept constant for 7 min, and then 200 g of base oil was added to rapidly cool the temperature. The temperature was lowered to 157°C, and then 83 g of base oil was added, and 7.2 g of naphthylamine and 14.4 g of a-naphthol were added. The temperature was continuously lowered to 82°C, and then 21.6 g of borate and 44.2 g of molybdenum dithiodialkyldithiocarbamate were added. Then 1.39 g of barium petroleum sulfonate and 8.91 g of benzothiazole were added, and the mixture was stirred uniformly. After dispersion and grinding by a post-treatment device, the product was filled into a can.

[0064] Comparative Example 1

[0065] The base oil of this example is a cycloparaffin mineral oil, and a composite barium-based grease is prepared according to the following method:

[0066] Into a reaction kettle were added 740 g of base oil, 72 g of stearic acid, and 14 g of malic acid, heated and stirred, and then heated to 90°C. Then 103 g of barium hydroxide octahydrate was slowly added, and the temperature was raised to 100°C to start saponification. The reaction was allowed to proceed for 56 min, and then the temperature was raised to 201°C after saponification was completed. The temperature was kept constant for 7 min, and then 200 g of base oil was added to rapidly cool the temperature. The temperature was lowered to 157°C, and then 83 g of base oil was added, and 7.2 g of naphthylamine and 14.4 g of a-naphthol were added. The temperature was continuously lowered to 82°C, and then 21.6 g of borate and 44.2 g of molybdenum dithiodialkyldithiocarbamate were added. Then 1.39 g of barium petroleum sulfonate and 8.91 g of benzothiazole were added, and the mixture was stirred uniformly. After dispersion and grinding by a post-treatment device, the product was filled into a can.

[0067] Comparative Example 2

[0068] The base oil of this comparative example is a mixed oil of naphthenic mineral oil, alkyl naphthalene, poly-alpha olefin synthetic oil in a weight ratio of 28:9:4. The complex barium-based grease is prepared as follows:

[0069] 961 g of base oil, 87 g of lauric acid, and 52 g of terephthalic acid are added to a reaction kettle, heated and stirred, and warmed to 86°C. 125 g of barium hydroxide octahydrate is slowly added, and warmed to 97°C to start saponification. The reaction is allowed to proceed for 55 min, and after saponification is complete, the temperature is raised to 202°C, and the temperature is held constant for 8 min. 295 g of base oil is added to rapidly cool the temperature, and the temperature is lowered to 160°C. 95 g of base oil is added, and 21.6 g of naphthylamine is added. The temperature is further lowered to 80°C, 21.6 g of phosphate ester and 44.2 g of molybdenum dithiodialkyldithiocarbamate are added, 8.75 g of benzothiazole is added, and after stirring is complete, the product is packaged after being dispersed and ground by a post-processing device.

[0070] Comparative Example 3

[0071] The complex barium-based thickener of this comparative example is generated by the reaction of 12-hydroxystearic acid, azelaic acid, and barium hydroxide. The complex barium-based grease is prepared as follows:

[0072] 740 g of base oil, 72 g of 12-hydroxystearic acid, and 14 g of azelaic acid are added to a reaction kettle. The base oil is a mixture of naphthenic mineral oil, alkyl naphthalene, and poly-alpha olefin synthetic oil in a weight ratio of 18:31:19. The mixture is heated and stirred, and warmed to 90°C. 103 g of barium hydroxide octahydrate is slowly added, and warmed to 100°C to start saponification. The reaction is allowed to proceed for 56 min, and after saponification is complete, the temperature is raised to 201°C, and the temperature is held constant for 7 min. 200 g of base oil is added to rapidly cool the temperature, and the temperature is lowered to 157°C. 83 g of base oil is added, and 7.2 g of naphthylamine and 14.4 g of alpha-naphthol are added. The temperature is further lowered to 82°C, 21.6 g of borate ester and 44.2 g of molybdenum dithiodialkyldithiocarbamate are added, 1.39 g of barium petroleum sulfonate and 8.91 g of benzothiazole are added, and after stirring is complete, the product is packaged after being dispersed and ground by a post-processing device.

[0073] Comparative Example 4

[0074] The base oil of this comparative example is a mixed oil of naphthenic mineral oil, alkyl naphthalene, poly-alpha olefin synthetic oil in a weight ratio of 20:30:19.

[0075] The antioxidant of this comparative example is diisooctyl diphenylamine, the extreme pressure anti-wear agent is calcium carbonate and zinc oxide, and the rust inhibitor is sodium petroleum sulfonate. The complex barium-based grease is prepared as follows:

[0076] Put 740 g base oil, 72 g stearic acid, 14 g malic acid into the reaction kettle, the base oil is a mixture of naphthenic mineral oil, alkyl naphthalene, poly-alpha olefin synthetic oil, the weight ratio is 18:31:19, heat and stir, heat to 86°C, slowly add 103 g barium hydroxide octahydrate, heat to 98°C to start saponification, react for 60 min, after saponification, heat to 195°C, constant temperature refining for 9 min, add 200 g base oil to cool down, cool to 162°C, add 83 g base oil, and add 21.6 g diisooctyl diphenylamine, continue to cool to 82°C, add 32.4 g calcium carbonate and 32.4 g zinc oxide, add 1.56 g petroleum sulfonic acid sodium, after stirring uniformly, disperse and grind by post-treatment equipment, and then pack in the finished product tank.

[0077] Experimental example

[0078] The lubricating greases obtained in Examples 1-6 and Comparative Examples 1-4 are subjected to performance testing (the test results are shown in Table 1).

[0079] Table 1 Lubricating grease performance test results

[0080]

[0081]

[0082] As can be seen from Table 1, by comparing the performances of the composite barium-based lubricating greases prepared in Examples 1-6 and Comparative Examples 1, 2, it can be found that after adding alkyl naphthalene and poly-alpha olefin synthetic oil to the naphthenic mineral oil base, and when the weight ratio of the three is within the range of (16-20):(28-35):(16-22), especially 18:31:19, the composite barium-based lubricating grease has better low-temperature performance, ensuring the normal lubrication of RV reducers and precision bearings used at low temperatures, in addition, it also improves the oxidation stability of the lubricating grease, and can effectively improve the anti-wear performance of the lubricating grease, reduce friction, thereby improving the performance and operating efficiency of the equipment, and prolonging the service life of the equipment. By comparing the performances of the composite barium-based lubricating greases prepared in Examples 1-6 and Comparative Example 3, it can be found that the use of the composite barium-based thickening agent of the present application can make the finally prepared lubricating grease have more excellent oxidation stability, colloidal stability and extreme pressure and wear resistance, and improve the performance of the lubricating grease product in all aspects. By comparing the performances of the composite barium-based lubricating greases prepared in Examples 1-6 and Comparative Example 4, it can be found that by optimizing the antioxidant and extreme pressure and wear resistant agent, the oxidation resistance and wear resistance of the lubricating grease are greatly improved, while the other performances of the composite barium-based lubricating grease are not greatly affected, ensuring that the lubricating grease still has excellent high-temperature resistance, colloidal stability, water resistance, etc., so that the lubricating grease provided by the present application can still exhibit good lubricating performance under harsh working conditions such as high temperature, high load and high water.

[0083] While the application has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various modifications or changes can be made therein without departing from the spirit and scope thereof. Accordingly, it is intended that all such modifications and changes be included within the scope of the application as claimed.

Claims

1. A barium-based composite grease, characterized in that: The barium complex grease comprises the following components, based on the weight of the grease: 75-89% base oil, 6-12% barium complex thickener, 0.6-3% antioxidant, 1-7% extreme pressure anti-wear agent, and 0.1-2% rust inhibitor, with the sum of the percentages of each component being 100%; the base oil is a mixture of naphthenic mineral oil, alkyl naphthalene, and polyalphaolefin synthetic oil; The weight ratio of naphthenic mineral oil, alkyl naphthalene and polyalphaolefin synthetic oil in the base oil is (16-20): (28-35): (16-22); The composite barium-based thickener is produced by reacting lauric acid, terephthalic acid and barium hydroxide; wherein the weight ratio of lauric acid to terephthalic acid is 1:0.6; and the weight ratio of the sum of the weight of lauric acid and terephthalic acid to barium hydroxide is 1.1:1; Alternatively, the composite barium-based thickener is produced by reacting stearic acid, malic acid, and barium hydroxide; wherein the weight ratio of stearic acid to malic acid is 1:0.2; and the weight ratio of the sum of the weights of stearic acid and malic acid to barium hydroxide is 0.8:1; The antioxidant comprises at least one of an amine antioxidant and a phenolic antioxidant; the amine antioxidant is selected from one or two of diphenylamine, naphthylamine and p-phenylenediamine; the phenolic antioxidant is selected from one or two of 2,6-di-tert-butyl-p-cresol and α-naphthol; The extreme pressure anti-wear agent is selected from one or more of zinc dialkyl dithiophosphate, molybdenum dialkyl dithiocarbamate, phosphate ester, and borate ester; The rust preventive agent is selected from one or more of barium petroleum sulfonate, benzothiazole, alkenyl succinic acid, and zinc naphthenate.

2. The barium complex grease according to claim 1, characterized in that Based on the weight of the barium complex grease, the barium complex grease includes the following components: 80-86% base oil, 7-10% barium complex thickener, 0.6-3% antioxidant, 1-7% extreme pressure anti-wear agent, and 0.1-2% rust inhibitor.

3. The barium complex grease according to claim 2, characterized in that: The weight ratio of naphthenic mineral oil, alkyl naphthalene and polyalphaolefin synthetic oil in the base oil is 18:31:

19.

4. The barium complex grease according to any one of claims 1 to 3, characterized in that: The kinematic viscosity of the base oil at 100°C is 5-60 mm 2 / s.

5. The barium complex grease according to claim 4, characterized in that The content of the antioxidant is 1-2% based on the weight of the complex barium-based grease; The content of the extreme pressure anti-wear agent is 3-6% based on the weight of the complex barium-based grease; Based on the weight of the complex barium-based grease, the content of the rust inhibitor is 0.1-0.9%.

6. The method for preparing the complex barium-based grease according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: mixing lauric acid and terephthalic acid, or stearic acid and malic acid, with an appropriate amount of base oil, heating the mixture to 75-90°C, stirring the mixture thoroughly, adding barium hydroxide, heating the mixture to 90-120°C, and performing a saponification reaction; after the reaction is complete, heating the mixture to 180-220°C for refining, and maintaining the temperature for 7-12 minutes; adding an appropriate amount of base oil, rapidly cooling the mixture to 140-170°C, and adding the remaining base oil and an antioxidant; further cooling the mixture to below 110°C, adding an extreme pressure anti-wear agent and a rust inhibitor, and performing stirring and post-processing to obtain a finished product.

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