Composite fatty amine polyurea lubricating grease and preparation method thereof

Abstract

The invention discloses composite fatty amine polyurea lubricating grease and a preparation method thereof, and belongs to the technical field of lubricating grease. Comprising the following raw materials in parts by weight: 80-120 parts of mineral base oil, 5-10 parts of fatty amine, 2-6 parts of isocyanate, 4-12 parts of a synergistic antioxidant, 2-8 parts of water, 20-30 parts of quenching oil, 3-6 parts of an anti-wear reagent at extreme pressure and 4-8 parts of an anti-rust agent. The prepared lubricating grease is excellent in performance, short-chain fatty amine and long-chain fatty amine are compounded, the short-chain fatty amine provides a high dropping point, the long-chain fatty amine provides a thickening ability to realize advantage complementation, and the comprehensive performance of the lubricating grease is improved; meanwhile, the prepared synergistic antioxidant can greatly enhance the oxidation stability and extreme pressure wear resistance of the lubricating grease, and is stable in performance and not easy to fall off.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating greases, and in particular, relates to a composite fatty amine polyurea lubricating grease and a preparation method thereof. Background Art

[0002] Polyurea grease is a type of non-soap grease, and its output is increasing year by year. Compared with soap-based grease, polyurea grease has the advantages of high temperature resistance and oxidation resistance, but it also has the disadvantages of poor shear resistance and storage hardening. This disadvantage is mainly caused by organic amines. Therefore, compounding with organic fatty amines of different chain lengths can effectively complement each other's shortcomings and improve overall performance.

[0003] CN111718773A discloses a polyurea thickener, a grease prepared therefrom and a method for preparing the grease, wherein a mixture of 2-amino-6-methoxybenzothiazole and R-NH2, wherein R is an alkyl or cycloalkyl group with a carbon number of 8 to 22, is compounded with aniline and alkylamine to prepare a polyurea grease with excellent performance.

[0004] CN116656411A discloses a method for preparing a high-temperature polyurea grease, which uses diisocyanates such as diphenylmethane-4,4'-diisocyanate, toluene diisocyanate and hexamethylene diisocyanate, organic amines such as octadecylamine, p-toluidine and cyclohexylamine, and is compounded with fatty amines, aniline and alicyclic amines to prepare a high-dropping-point polyurea grease.

[0005] CN104560265B discloses a polyurea grease and a preparation method thereof, wherein a base oil is thickened with graphene and a polyurea compound. The method has simple process, environmental protection, and stable quality, and an organic monoamine is used as a thickener component.

[0006] In combination with the above inventions, the first method uses aniline and alkylamine to prepare polyurea grease, and the product has excellent performance, but aniline is expensive and generally toxic; the second method is to prepare high-temperature grease, using fatty amines in combination with aniline and alicyclic amines to prepare polyurea grease, which also has the disadvantages of high cost, high raw material toxicity, and poor shear resistance. Not only that, grease is prone to oxidation when working, and traditional antioxidants will fall off during use, resulting in reduced performance of the grease. Therefore, it is urgent to invent a polyurea grease with simple and stable process and good and stable performance to fill the gap. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects of the prior art and provide a composite fatty amine polyurea grease and a preparation method thereof.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A method for preparing a composite fatty amine polyurea grease comprises the following steps:

[0010] A1. Mix mineral base oil, fatty amine, isocyanate and synergistic antioxidant in a reaction kettle, react at 80-100° C. for 1-2 hours, and maintain the temperature at 80-100° C. after the reaction is completed;

[0011] A2. Add water to the reaction kettle in step A1 to remove isocyanate, and react at 80-100° C. for 30 min;

[0012] A3. Heat the reactor of step A2 to 180-200°C, then add quenching oil, cool to 80-100°C after 1-2h, add extreme pressure anti-wear agent and rust inhibitor, stir evenly; cool to room temperature and grind homogenously 2-3 times to obtain composite fatty amine polyurea grease.

[0013] Furthermore, the raw materials are calculated in parts by weight as follows: 80-120 parts of mineral base oil, 5-10 parts of fatty amine, 2-6 parts of isocyanate, 4-12 parts of synergistic antioxidant, 2-8 parts of water, 20-30 parts of quench oil, 3-6 parts of extreme pressure anti-wear agent, and 4-8 parts of rust inhibitor.

[0014] Furthermore, the fatty amine is two or more of octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine and octadecylamine.

[0015] Furthermore, the extreme pressure anti-wear agent is one of sulfurized fatty acid ester, sulfurized lard and triethyl phosphate.

[0016] Furthermore, the rust inhibitor is one or both of sulfonate and benzotriazole.

[0017] The prepared composite fatty amine polyurea has excellent lubricating performance, and the use of composite fatty amine can improve the overall high temperature and shear resistance of the grease.

[0018] Further, the synergistic antioxidant is prepared by the following steps:

[0019] S1. In a three-necked flask equipped with a thermometer, an electromagnetic stirrer and a spherical condenser, a drying tube is added to the outlet of the condenser, and the drying tube is connected to a tail gas absorption device to absorb the generated hydrogen chloride gas. After pentaerythritol and benzene are mixed, phosphorus trichloride is slowly added dropwise under stirring, and the temperature is controlled not to exceed 30° C. After the addition is completed, the temperature is raised to 72° C., and the reaction is refluxed for 3 hours. After the reaction is completed, the solvent benzene and excess phosphorus trichloride are distilled off to obtain dichloropentaerythritol phosphite; the ratio of pentaerythritol, benzene and phosphorus trichloride is 13.6g:100mL:27.4g;

[0020] Pentaerythritol reacts with phosphorus trichloride to obtain dichloropentaerythritol phosphite; the specific reaction is as follows:

[0021]

[0022] S2. In a three-necked flask equipped with a stirring device, dichloropentaerythritol phosphite, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, potassium carbonate (acid binding agent) and N,N-dimethylformamide (DMF) were mixed and stirred uniformly, the reaction temperature was controlled to 75°C, and the reaction was kept warm for 6 hours. After the reaction was completed, the mixture was filtered, and part of the solvent was removed by rotary evaporation. The mixture was then purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate in a volume ratio of 4:3), and the eluent was removed by rotary evaporation to obtain intermediate 1; the ratio of dichloropentaerythritol phosphite, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, potassium carbonate and N,N-dimethylformamide was 28.7 g:23.6 g:15 mL:100 mL;

[0023] Under the catalysis of potassium carbonate, dichloropentaerythritol phosphite and 3,5-di-tert-butyl-4-hydroxybenzyl alcohol react, and by controlling the molar ratio of the two to be close to 1:1 and the dichloropentaerythritol phosphite to be slightly excessive, only one chlorine group on the dichloropentaerythritol phosphite participates in the reaction to obtain intermediate 1; the specific reaction process is as follows:

[0024]

[0025] S3, in a three-necked flask equipped with a stirring device, 4-hydroxystyrene, intermediate 1, triethylamine (acid binding agent) and toluene were mixed and stirred uniformly, the reaction temperature was controlled to 75 ° C, the reaction was kept warm for 8 hours, the reaction was completed, the triethylamine hydrochloride was filtered out, part of the solvent was removed by rotary evaporation, and then purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate, the volume ratio of the two was 5:3), the eluent was removed by rotary evaporation to obtain intermediate 2; the ratio of the amount of 4-hydroxystyrene, intermediate 1, triethylamine, and toluene was 11.9g:46.4g:15mL:120mL;

[0026] Triethylamine is used as an acid-binding agent to remove the hydrogen chloride generated by the reaction, and 4-hydroxystyrene and intermediate 1 undergo a nucleophilic substitution reaction to obtain intermediate 2. The specific reaction process is as follows:

[0027]

[0028] S4. Add intermediate 2, azobisisobutyronitrile (AIBN), mercaptoethylamine and toluene into a three-necked flask and stir to mix evenly. Maintain the temperature of the system at 80°C and keep the reaction for 6 hours. After the reaction is completed, distill under reduced pressure and purify by column chromatography (the eluent is a mixed solvent of ethyl acetate / benzene in a volume ratio of 2:5). Remove the eluent by rotary evaporation to obtain a synergistic antioxidant; the ratio of intermediate 2, AIBN, mercaptoethylamine and toluene is 54.8 g:0.8 g:7.7 g:120 mL;

[0029] Under the action of AIBN, the unsaturated carbon-carbon double bond on the intermediate 2 molecule undergoes a thiol-ene click reaction with the thiol group of mercaptoethylamine to obtain a synergistic antioxidant; the specific reaction process is as follows:

[0030]

[0031] The prepared synergistic antioxidant molecule contains phosphite, hindered phenol, sulfur element and amino structure. Among them, the introduced phosphite can be used as a kind of auxiliary antioxidant, which can decompose the hydroperoxide generated in the polymer due to oxidative aging and make it inactive, thereby achieving the purpose of terminating or delaying the oxidative degradation of the polymer; moreover, the hindered phenol group belongs to phenolic antioxidants, and the structure of this type of antioxidant contains -OH functional group, which is easier to provide H atoms in the reaction. This process occurs through proton donation, so that the free radical auto-oxidation in the chain reaction is destroyed, achieving the antioxidant effect. , can play a synergistic role with phosphites, greatly enhancing the oxidation stability of grease; in addition, elemental sulfur can react with metals to form a sulfide film, thereby playing an anti-wear role. Not only that, when the working conditions are harsh or enter extreme pressure conditions, an inorganic sulfide protective film can be generated due to the breakage of the CS bond, which can give the grease strong extreme pressure and wear resistance, and can play a synergistic role with phosphorus and nitrogen elements to further enhance the extreme pressure and anti-wear properties of the grease; finally, the introduced amino group can participate in the polymerization reaction and connect to the macromolecular chain of polyurea, thereby improving the migration and exudation resistance of the synergistic antioxidant and improving the stability of the synergistic antioxidant.

[0032] Beneficial effects of the present invention:

[0033] 1. The lubricating grease prepared by the present invention adopts a variety of fatty amine composite components, which can improve the overall shear resistance, high temperature performance and storage stability of the lubricating grease;

[0034] 2. The synergistic antioxidant produced can greatly enhance the oxidation stability and extreme pressure and wear resistance of the grease, and has stable performance and is not easy to fall off;

[0035] Therefore, the grease prepared by the present invention has a simple process, excellent overall performance, stable and efficient oxidation stability and extreme pressure and wear resistance, and has important application value in the field of grease technology. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] Preparation of synergistic antioxidants:

[0039] S1. In a three-necked flask equipped with a thermometer, an electromagnetic stirrer and a spherical condenser, a drying tube is added to the outlet of the condenser, and the drying tube is connected to a tail gas absorption device to absorb the generated hydrogen chloride gas. After mixing 13.6 g of pentaerythritol and 100 mL of benzene, 27.4 g of phosphorus trichloride is slowly added dropwise under stirring, and the temperature is controlled not to exceed 30° C. After the addition is completed, the temperature is raised to 72° C., and the reaction is refluxed for 3 hours. After the reaction is completed, the solvent benzene and excess phosphorus trichloride are removed by distillation to obtain dichloropentaerythritol phosphite;

[0040] S2, in a three-necked flask equipped with a stirring device, 28.7g of dichloropentaerythritol phosphite, 23.6g of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, 15mL of potassium carbonate and 100mL of N,N-dimethylformamide were mixed and stirred uniformly, the reaction temperature was controlled to 75°C, and the reaction was kept warm for 6h. After the reaction was completed, it was filtered, and part of the solvent was removed by rotary evaporation, and then purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate, and the volume ratio of the two was 4:3), and the eluent was removed by rotary evaporation to obtain intermediate 1;

[0041] S3, in a three-necked flask equipped with a stirring device, 11.9g 4-hydroxystyrene, 46.4g intermediate 1, 15mL triethylamine and 120mL toluene were mixed and stirred uniformly, the reaction temperature was controlled to 75°C, and the reaction was kept warm for 8h. After the reaction was completed, triethylamine hydrochloride was filtered out, and part of the solvent was removed by rotary evaporation, and then purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate, and the volume ratio of the two was 5:3), and the eluent was removed by rotary evaporation to obtain intermediate 2;

[0042] S4. Add 54.8 g of intermediate 2, 0.8 g of azobisisobutyronitrile, 7.7 g of mercaptoethylamine and 120 mL of toluene into a three-necked flask and stir to mix evenly. Maintain the temperature of the system at 80°C and react for 6 hours. After the reaction is completed, evaporate under reduced pressure and purify by column chromatography (the eluent is a mixed solvent of ethyl acetate / benzene in a volume ratio of 2:5). Remove the eluent by rotary evaporation to obtain a synergistic antioxidant.

[0043] Example 2

[0044] Preparation of synergistic antioxidants:

[0045] S1. In a three-necked flask equipped with a thermometer, an electromagnetic stirrer and a spherical condenser, a drying tube is added to the outlet of the condenser, and the drying tube is connected to a tail gas absorption device to absorb the generated hydrogen chloride gas. After mixing 27.2 g of pentaerythritol and 200 mL of benzene, 54.8 g of phosphorus trichloride is slowly added dropwise under stirring, and the temperature is controlled not to exceed 30° C. After the addition is completed, the temperature is raised to 72° C., and the reaction is refluxed for 3 hours. After the reaction is completed, the solvent benzene and excess phosphorus trichloride are removed by distillation to obtain dichloropentaerythritol phosphite;

[0046] S2, in a three-necked flask equipped with a stirring device, 57.4g of dichloropentaerythritol phosphite, 47.2g of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, 30mL of potassium carbonate and 200mL of N,N-dimethylformamide were mixed and stirred uniformly, the reaction temperature was controlled to 75°C, and the reaction was kept warm for 6h. After the reaction was completed, it was filtered, and part of the solvent was removed by rotary evaporation, and then purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate, and the volume ratio of the two was 4:3), and the eluent was removed by rotary evaporation to obtain intermediate 1;

[0047] S3, in a three-necked flask equipped with a stirring device, 23.8g 4-hydroxystyrene, 92.8g intermediate 1, 30mL triethylamine and 240mL toluene were mixed and stirred uniformly, the reaction temperature was controlled to 75°C, and the reaction was kept warm for 8h. After the reaction was completed, triethylamine hydrochloride was filtered out, and part of the solvent was removed by rotary evaporation, and then purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate, and the volume ratio of the two was 5:3), and the eluent was removed by rotary evaporation to obtain intermediate 2;

[0048] S4. Add 109.6 g of intermediate 2, 1.6 g of azobisisobutyronitrile, 15.4 g of mercaptoethylamine and 240 mL of toluene into a three-necked flask and stir to mix evenly. Maintain the temperature of the system at 80°C and react for 6 hours. After the reaction is completed, evaporate under reduced pressure and purify by column chromatography (the eluent is a mixed solvent of ethyl acetate / benzene in a volume ratio of 2:5). Remove the eluent by rotary evaporation to obtain a synergistic antioxidant.

[0049] Example 3

[0050] A1. In a reactor, 80 g of 500N base oil, 3 g of dodecylamine, 3.5 g of hexadecylamine, 4 g of MDI and 4 g of the synergistic antioxidant prepared in Example 1 were mixed and reacted at 80° C. for 1 h. After the reaction was completed, the temperature was maintained at 80° C.;

[0051] A2, add 2g of water to the reaction kettle of step A1, mix, and react at 80°C for 30min;

[0052] A3. Heat the reactor of step A2 to 180°C, then add 20g 500N quench oil, cool to 80°C after 1h, add 3g sulphurized lard and 4g sulfonate, stir evenly; cool to room temperature and grind twice to obtain composite fatty amine polyurea grease.

[0053] Example 4

[0054] A1. In a reactor, 100 g of 500N base oil, 6 g of octadecylamine, 3 g of dodecylamine, 5 g of MDI and 8 g of the synergistic antioxidant prepared in Example 1 were mixed and reacted at 80° C. for 1-2 h. After the reaction was completed, the temperature was maintained at 100° C.;

[0055] A2. Add 5 g of water to the reaction kettle in step A1 and mix, and react at 100° C. for 30 min;

[0056] A3. Heat the reactor of step A2 to 200°C, then add 20g 500N quench oil, cool to 100°C after 1h, add 4g triethyl phosphate and 6g benzotriazole, stir evenly; cool to room temperature and grind homogenously 3 times to obtain composite fatty amine polyurea grease.

[0057] Example 5

[0058] A1. In a reactor, 120 g of 500N base oil, 7.7 g of hexadecylamine, 4 g of octadecylamine, 6 g of MDI and 12 g of the synergistic antioxidant prepared in Example 2 were mixed and reacted at 100° C. for 2 h. After the reaction was completed, the temperature was maintained at 100° C.;

[0059] A2, add 8g of water to the reactor in step A1, mix, and react at 100°C for 30min;

[0060] A3. Heat the reactor of step A2 to 200°C, then add 30g 500N quench oil, cool to 100°C after 2h, add 6g triethyl phosphate and 8g benzotriazole, stir evenly; cool to room temperature and grind homogenously 3 times to obtain composite fatty amine polyurea grease.

[0061] Comparative Example 1

[0062] A1. Add 50g of 500N base oil into the reactor to dissolve 5.3g of octadecylamine, then add 2.5g of MDI and react at 80°C for 1h;

[0063] A2, add 6g of water to the reactor in step A1, stir at 100°C for 10min, and then refine to 200°C;

[0064] A3, add 10g 500N quench oil, 3g triethyl phosphate, 6g synergistic antioxidant prepared in Example 2 and 4g benzotriazole to the reactor in step A2, cool to room temperature, grind 3 times to extract fat;

[0065] A4. Heat 50 g of 500N base oil to 80°C in a reactor to dissolve 5.8 g of dodecyl stearic acid, and maintain the temperature at 80°C after dissolution;

[0066] A5. Add 0.6 g lithium hydroxide and 1.8 g water into the reactor of step A4, stir for 5 min, then add 0.2 g calcium hydroxide and 0.6 g water; stir and react for 1 h;

[0067] A6, refine the reactor of step A5 to 210°C, add 10g 500N quench oil, 3g triethyl phosphate, 6g synergistic antioxidant prepared in Example 2 and 4g benzotriazole, cool to room temperature, grind 3 times to extract fat;

[0068] A7. Evenly mix the lithium calcium greases of step A3 and step A6, and grind again to obtain grease.

[0069] Comparative Example 2

[0070] The synergistic antioxidant in Example 5 was replaced by a commercially available hindered phenol antioxidant of equal mass, and the remaining steps were the same as in Example 5 to prepare a lubricating grease.

[0071] The following performance tests were performed on the greases of Examples 3-5 and Comparative Examples 1-2:

[0072] The dropping point is measured using the national standard GB / T 3498 "Determination of dropping point of lubricating grease over a wide temperature range";

[0073] The national standard GB / T 269 "Cone penetration test for lubricating greases and petroleum greases" is used to test the shear stability (the difference between the extended working cone penetration and the working cone penetration);

[0074] The national standard GB / T 5096 "Petroleum Products Copper Strip Corrosion Test Method" is used to determine the copper strip corrosion level;

[0075] The national standard GB / T 5018 "Test method for anti-corrosion of lubricating grease" is used to determine whether the anti-corrosion is qualified;

[0076] The wear spot diameter of the sample before and after 90 days at room temperature was measured using NB / SH / T 0189 "Determination of anti-wear properties of lubricating oils - four-ball method";

[0077] The national standard SH / T 0193-2008 "Determination of oxidation stability of lubricating oil - Rotating oxygen bomb method" was used to determine the oxidation stability of the sample before and after being placed at room temperature for 90 days;

[0078] Use an electronic watch to measure the synthesis time;

[0079] The measured results are shown in the following table:

[0080]

[0081] It can be seen from the above table that the grease prepared in the embodiment of the present invention has a short synthesis time, short-chain fatty amines provide a high dropping point, long-chain fatty amines provide thickening ability, the overall performance is excellent, and it has stable and efficient oxidation stability and extreme pressure and wear resistance, and has important application value in the field of grease technology.

[0082] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0083] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing a composite fatty amine polyurea grease, characterized in that: The following steps are involved: A1. Mix mineral base oil, fatty amine, isocyanate and synergistic antioxidant in a reactor, react at 80-100° C. for 1-2 hours, and maintain the temperature at 80-100° C. after the reaction is completed; A2. Add water to the reaction kettle of step A1 and react at 80-100°C for 30 minutes; A3. Heat the reactor of step A2 to 180-200°C, then add quenching oil, cool to 80-100°C after 1-2h, add extreme pressure anti-wear agent and rust inhibitor, stir evenly; cool to room temperature and grind homogenously to obtain composite fatty amine polyurea grease.

2. The method for preparing a composite fatty amine polyurea grease according to claim 1, characterized in that: The synergistic antioxidant is prepared by the following steps: S1. After pentaerythritol and benzene are mixed, phosphorus trichloride is added dropwise under stirring, and the temperature is controlled not to exceed 30° C. After the addition is completed, reflux reaction is carried out at 72° C. for 3 hours. After the reaction is completed, distillation is performed to obtain dichloropentaerythritol phosphite; S2, dichloropentaerythritol phosphite, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, potassium carbonate and N,N-dimethylformamide were mixed and stirred evenly, reacted at 75° C. for 6 h, and after the reaction was completed, filtered, rotary evaporated, purified by column chromatography, and rotary evaporated to obtain intermediate 1; S3, 4-hydroxystyrene, intermediate 1, triethylamine and toluene were mixed and stirred, reacted at 75°C for 8 hours, and after the reaction was completed, filtered, rotary evaporated, purified by column chromatography, and rotary evaporated to obtain intermediate 2; S4. The intermediate 2, azobisisobutyronitrile, mercaptoethylamine and toluene are stirred and mixed evenly, and reacted at 80° C. for 6 h. After the reaction is completed, vacuum distillation is performed, column chromatography is performed for purification, and rotary evaporation is performed to obtain a synergistic antioxidant.

3. The method for preparing a composite fatty amine polyurea grease according to claim 2, characterized in that: In step S1, the ratio of pentaerythritol, benzene and phosphorus trichloride is 13.6 g:100 mL:27.4 g.

4. The method for preparing a composite fatty amine polyurea grease according to claim 2, characterized in that: In step S2, the ratio of the amount of dichloropentaerythritol phosphite, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, potassium carbonate and N,N-dimethylformamide is 28.7 g:23.6 g:15 mL:100 mL.

5. The method for preparing a composite fatty amine polyurea grease according to claim 2, characterized in that: In step S3, the ratio of 4-hydroxystyrene, intermediate 1, triethylamine and toluene is 11.9 g:46.4 g:15 mL:120 mL.

6. The method for preparing a composite fatty amine polyurea grease according to claim 2, characterized in that: In step S4, the ratio of the amount of intermediate 2, azobisisobutyronitrile, mercaptoethylamine, and toluene is 54.8 g: 0.8 g: 7.7 g: 120 mL.

7. The method for preparing a composite fatty amine polyurea grease according to claim 1, characterized in that: The raw materials are calculated in parts by weight as follows: 80-120 parts of mineral base oil, 5-10 parts of fatty amine, 2-6 parts of isocyanate, 4-12 parts of synergistic antioxidant, 2-8 parts of water, 20-30 parts of quench oil, 3-6 parts of extreme pressure anti-wear agent, and 4-8 parts of rust inhibitor.

8. The method for preparing a composite fatty amine polyurea grease according to claim 1, characterized in that: The fatty amines are two or more of octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine and octadecylamine.

9. A composite fatty amine polyurea grease, characterized in that: Prepared according to the method according to any one of claims 1 to 8.

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