Lubricating oil antiwear agents and methods for their preparation

Abstract

The application belongs to the technical field of anti-wear agents, and particularly relates to a lubricating oil anti-wear agent and a preparation method thereof.The lubricating oil anti-wear agent comprises the following raw materials: sulfur-modified n-butyl oleate, molybdenum dialkyldithiocarbamate, ammonium salt of di(2-ethylhexyl) phosphate, boron-nitrogen modified pentaerythritol trioleate, a cleaning dispersant, an antioxidant, a pour point depressant, an antifoaming agent, and a base oil as the balance.The lubricating oil anti-wear agent comprises sulfur-modified n-butyl oleate, boron-nitrogen modified pentaerythritol trioleate, molybdenum dialkyldithiocarbamate and ammonium salt of di(2-ethylhexyl) phosphate as main anti-wear components, and the four components have a synergistic effect, so that the prepared lubricating oil anti-wear agent has good anti-wear property under medium and extreme pressure working conditions.

Description

Technical Field

[0001] This invention belongs to the field of anti-wear agent technology, specifically relating to a lubricating oil anti-wear agent and its preparation method. Background Technology

[0002] During the operation of mechanical equipment, the lubrication state of friction pairs directly affects the equipment's efficiency, energy consumption, and service life. According to traditional lubrication theory, lubrication is divided into liquid lubrication and boundary lubrication. Liquid lubrication occurs when two metal surfaces in relative motion are completely separated by a lubricating oil film, with no direct metal-to-metal contact. Boundary lubrication occurs when the oil film between the metal surfaces gradually thins as the load increases. When the load reaches a certain level, the continuous oil film is disrupted by the peaks on the metal surfaces, resulting in localized direct contact between the metal surfaces. In boundary lubrication, when the metal surfaces are only subjected to moderate loads, an additive that can be adsorbed onto the metal surface or experience severe wear is called an anti-wear additive.

[0003] Currently, commonly used anti-wear additives in industry are mainly based on active elements such as sulfur, phosphorus, nitrogen, and boron. Among them, sulfur-based, phosphorus-based, and single boron-based additives are the most widely used, but each has significant drawbacks: sulfur-based extreme pressure anti-wear additives have excellent extreme pressure performance, but the active sulfur they contain can easily corrode machine parts; phosphorus-based anti-wear additives have outstanding anti-wear performance, but their extreme pressure performance is relatively weak, and phosphorus can poison the three-way catalyst of gasoline engines, and the generated ash can easily clog the filter system, affecting the normal operation of the equipment; single boron-based additives can reduce friction through film formation, but the film stability is insufficient, and it is easy to fall off under complex load conditions, making it difficult to meet the lubrication needs of all scenarios such as low and medium loads, medium loads, and extreme pressure conditions.

[0004] In addition, existing lubricating oil anti-wear agents are mostly single systems or simple compound formulations. Compound systems only pursue anti-wear effects under a single load. In actual working conditions with fluctuating loads, it is difficult to form a stable lubricating film. Therefore, it is necessary to explore a new type of lubricating oil anti-wear agent. Summary of the Invention

[0005] The purpose of this invention is to provide a lubricating oil anti-wear agent, which exhibits excellent anti-wear properties under both medium and extreme pressure conditions. Furthermore, this invention also provides a method for its preparation.

[0006] The lubricating oil anti-wear agent of this invention, by mass percentage, is composed of the following raw materials: 1.9-2.1% sulfur-modified n-butyl oleate, 0.48-0.50% molybdenum dialkyl dithiocarbamate, 0.4-0.5% ammonium di(2-ethylhexyl) phosphate, 5.3-5.5% boron-nitrogen-modified pentaerythritol trioleate, 1.8-2.0% detergent-dispersant, 0.4-0.6% antioxidant, 0.3% pour point depressant, 0.1% antifoaming agent, with base oil as the balance. The preparation method of the boron-nitrogen-modified pentaerythritol trioleate is as follows: Under a nitrogen atmosphere, pentaerythritol trioleate, tri-n-butyl borate, tetrabutyl titanate, and 2,6-di-tert-butyl-p-cresol were added to the reaction apparatus and stirred until homogeneous. The mixture was heated to 93°C and reacted for 2 hours. The temperature was then lowered to 40°C and oil amine was added dropwise. After the addition was complete, the temperature was raised to 80°C and maintained for 1 hour. Then, the temperature was raised to 100°C at a rate of 1.1°C / min and maintained for 1.2 hours. Finally, the temperature was raised to 140°C at a rate of 1.1°C / min and maintained for 1.5 hours. After the reaction was completed, boron-nitrogen modified pentaerythritol trioleate was prepared through post-treatment.

[0007] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the stirring temperature is 25℃ and the stirring time is 13min.

[0008] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the temperature is raised to 93℃ and the reaction is carried out for 2 hours, and the reaction pressure is -0.085MPa.

[0009] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the molar ratio of pentaerythritol trioleate, tributyl borate, and oleylamine is 1:1.05:2.0. The CAS number of pentaerythritol trioleate is 39874-62-9, and the manufacturer is Jiaxing Zhongcheng Environmental Protection Technology Co., Ltd.

[0010] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the mass of tetrabutyl titanate accounts for 0.5% of the total mass of pentaerythritol trioleate, tri-n-butyl borate, and oleylamine.

[0011] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the mass of 2,6-di-tert-butyl-p-cresol accounts for 0.30% of the total mass of pentaerythritol trioleate, tri-n-butyl borate, and oleylamine.

[0012] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the reaction pressure is controlled at -0.085 MPa during the reaction process of heating from 80℃ to 140℃ and holding at that temperature.

[0013] The post-treatment described in the preparation method of boron-nitrogen modified pentaerythritol trioleate is as follows: after the reaction is completed, the mixture is distilled under reduced pressure at 140℃ and -0.095MPa for 35 min, followed by vacuum filtration to obtain boron-nitrogen modified pentaerythritol trioleate.

[0014] The preparation method of sulfur-modified n-butyl oleate is as follows: under nitrogen protection, n-butyl oleate and methyl 3-mercaptopropionate are added to a reaction vessel and stirred at 60°C for 20 min. Azobisisobutyronitrile is added and stirring is continued for 10 min. The temperature is raised to 85°C within 50 min and kept at that temperature for 3.5 h. After the reaction is completed, the temperature is lowered to 70°C and 2,6-di-tert-butyl-p-cresol is added and stirred for 10 min. Finally, the temperature is lowered to 60°C and vacuum filtered while hot to prepare sulfur-modified n-butyl oleate.

[0015] In the preparation method of sulfur-modified n-butyl oleate, the mass ratio of n-butyl oleate, methyl 3-mercaptopropionate, and azobisisobutyronitrile is 100:38:1.0, and the mass of 2,6-di-tert-butyl-p-cresol accounts for 0.1% of the mass of n-butyl oleate.

[0016] In the preparation method of sulfur-modified n-butyl oleate, the pressure of hot vacuum filtration is -0.08 MPa.

[0017] The detergent dispersant is a mixture of calcium petroleum sulfonate and magnesium petroleum sulfonate, with a mass ratio of 1.88:1. The manufacturer of calcium petroleum sulfonate is Jinzhou Chenghua New Materials Co., Ltd., and its model number is T103. The manufacturer of magnesium petroleum sulfonate is Jinzhou Shengda Chemical Co., Ltd., and its model number is T107.

[0018] The antioxidant is a mixture of dioctyl diphenylamine and 2,6-di-tert-butyl-p-cresol, with a mass ratio of 2:1.

[0019] The pour point depressant is polymethyl methacrylate, and the antifoaming agent is a 1% polydimethylsiloxane solution. 1g of polydimethylsiloxane is added to 99g of polyalphaolefin PAO 6 and stirred at 60℃ for 30min to prepare a 1% polydimethylsiloxane solution.

[0020] The base oil is a mixture of polyalphaolefin (PAO) 6 and polyalphaolefin (PAO) 40, wherein the mass ratio of PAO 6 to PAO 40 is 2.3:1. Both PAO 40 and PAO 6 are manufactured by Shenzhen Huashengyuan Petroleum Technology Co., Ltd.

[0021] The preparation method of the lubricating oil anti-wear agent of the present invention comprises the following steps:

[0022] (1) Under a nitrogen atmosphere, add base oil to the reaction apparatus and mix well;

[0023] (2) Add sulfur-modified n-butyl oleate, molybdenum dialkyl dithiocarbamate, ammonium di(2-ethylhexyl) phosphate and boron-nitrogen-modified pentaerythritol trioleate to the base oil in step (1) and stir to mix well.

[0024] (3) Add the cleaning and dispersing agent and the antioxidant to the reaction system of step (2) in sequence and stir until well mixed;

[0025] (4) Add pour point depressant to the mixture prepared in step (3) and stir for 15-17 min, then add antifoaming agent and stir for 10-13 min, and finally after post-treatment, the lubricating oil anti-wear agent is prepared.

[0026] In step (1), the mixing temperature is 60-62℃ and the mixing time is 30-35min.

[0027] In step (2), the mixing temperature is 60-62℃. After adding sulfur-modified n-butyl oleate and stirring for 10-12 min, molybdenum dialkyl dithiocarbamate is added and stirred for 10-12 min. Then, ammonium di(2-ethylhexyl) phosphate is added and stirred for 10-12 min. After that, boron-nitrogen-modified pentaerythritol trioleate is added and stirred for another 10-12 min.

[0028] In step (3), the mixing temperature is 60-62℃. Add the cleaning and dispersing agent and mix for 30-35 minutes. Then add the antioxidant and mix for 20-23 minutes.

[0029] In step (4), pour point depressant is added at 60-62℃, and antifoaming agent is added after cooling to 48-50℃.

[0030] During the mixing process of steps (1)-(4), nitrogen gas is continuously introduced to maintain the system pressure at 0.05 MPa.

[0031] The post-treatment described in step (4) involves standing at 58-60℃ under nitrogen protection for 10-12 minutes to degas, followed by vacuum filtration at a pressure of -0.08 MPa, collecting the filtrate, and preparing the lubricating oil anti-wear agent.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] (1) The lubricating oil anti-wear agent of the present invention uses sulfur-modified n-butyl oleate, boron-nitrogen-modified pentaerythritol trioleate, molybdenum dialkyl dithiocarbamate and di(2-ethylhexyl) phosphate ammonium salt as the main anti-wear components. The four components work synergistically. Among them, sulfur-modified n-butyl oleate is a highly active sulfur fast film agent. The thioether bond breaks under extreme pressure and forms a ferrous sulfide chemical reaction film with iron. The long carbon chain in its molecular structure provides oiliness, and the ester group enhances metal adsorption. Boron-nitrogen-modified pentaerythritol Trioleate acts as a friction reducer and extreme pressure anti-wear agent; molybdenum dialkyldithiocarbamate undergoes thermal decomposition to generate MoS2 nanosheets in situ, replacing sliding friction with rolling friction; ammonium di(2-ethylhexyl) phosphate acts as a phosphorus-nitrogen fast film agent, with phosphate ions undergoing a displacement reaction with iron oxide on the metal surface to form an Fe-OP chemically bonded film, reducing the coefficient of friction; the polar head of the phosphate enhances oil-metal interface adsorption, synergistically working with the sulfur, boron, and molybdenum-based extreme pressure film to maintain continuous lubrication under medium to high loads. Thus, the synergistic effect between the raw materials ensures that the prepared lubricating oil anti-wear agent exhibits excellent anti-wear properties under both medium and extreme pressure conditions.

[0034] (2) In the preparation method of the boron-nitrogen modified pentaerythritol trioleate as the lubricating oil anti-wear agent of the present invention, under the catalysis of tetrabutyl titanate, the free hydroxyl groups of pentaerythritol trioleate undergo transesterification reaction with tri-n-butyl borate to generate a boron-containing ester intermediate; the intermediate undergoes an amine substitution reaction with oleylamine to generate BN bonds and release n-butanol. The reaction is maintained under a slight negative pressure throughout to evaporate the n-butanol and promote the reaction to proceed to completion, thereby preparing boron-nitrogen modified pentaerythritol trioleate. The boron-nitrogen modified pentaerythritol trioleate exhibits enhanced polarity of BN bonds and ester groups under low to medium load conditions, leading to physical adsorption on the metal surface, reducing the friction coefficient and wear. Under moderate load conditions, the boron ester groups react with metal surface oxides to generate BO-Fe chemical bonds, forming a boron-containing glassy oxide film that fills surface micro-pits and reduces roughness. Under extreme pressure conditions, the high temperature and high shear force at the friction interface promote thermal decomposition / tribochemical reactions of boron-nitrogen compounds, resulting in in-situ film formation on the metal surface. This film exhibits low shear strength and high hardness, effectively isolating direct metal contact, preventing adhesive wear and ploughing wear, and significantly improving extreme pressure anti-wear performance.

[0035] (3) In the preparation method of sulfur-modified n-butyl oleate in the lubricating oil anti-wear agent of the present invention, the n-butyl oleate molecule contains one C9-C. 10The cis-carbon double bond serves as the active site for free radical addition. Methyl 3-mercaptopropionate contains thiol and ester groups; the thiol group is the active group, and the ester group is the polar functional group, which can enhance the polarity and lipophilicity of the modified product. Through free radical addition reaction, sulfur-modified n-butyl oleate is prepared. Under extreme pressure conditions, the thioether bond breaks, reacting chemically with the metal surface. Sulfur atoms react with iron to form a ferrous sulfide film. The ferrous sulfide film has a layered structure and low shear strength, preventing direct contact between the metal surface and the metal. Under boundary lubrication conditions, this chemical film can withstand extremely high loads, preventing "seizure" and "sintering." The thioether group undergoes physical adsorption on the friction surface, forming an adsorption film; the long carbon chain in the molecule (oleic acid part) provides oiliness and improves lubrication; the polarity of the ester group enhances the adsorption capacity of the molecule on the metal surface, while its carbon chain structure ensures good solubility in lubricating oil; the physical adsorption film (under medium and low load conditions) and the chemical reaction film (under extreme pressure conditions) work synergistically to achieve a good anti-wear effect. Detailed Implementation

[0036] The preparation methods for sulfur-modified n-butyl oleate and boron-nitrogen-modified pentaerythritol trioleate in Examples 1-3 are the same, as shown below:

[0037] The preparation method of boron-nitrogen modified pentaerythritol trioleate is as follows: Under a nitrogen atmosphere, pentaerythritol trioleate, tri-n-butyl borate, tetrabutyl titanate, and 2,6-di-tert-butyl-p-cresol are added to the reaction apparatus and stirred until homogeneous. The mixture is heated to 93°C and reacted for 2 hours. Then, the temperature is lowered to 40°C and oil amine is added dropwise. After the addition is complete, the temperature is raised to 80°C and maintained for 1 hour. Then, the temperature is raised to 100°C at a rate of 1.1°C / min and maintained for 1.2 hours. Finally, the temperature is raised to 140°C at a rate of 1.1°C / min and maintained for 1.5 hours. After the reaction is complete, boron-nitrogen modified pentaerythritol trioleate is obtained through post-processing.

[0038] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the stirring temperature is 25℃ and the stirring time is 13min.

[0039] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the temperature is raised to 93℃ and the reaction is carried out for 2 hours, and the reaction pressure is -0.085MPa.

[0040] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the molar ratio of pentaerythritol trioleate, tributyl borate, and oleylamine is 1:1.05:2.0. The CAS number of pentaerythritol trioleate is 39874-62-9, and the manufacturer is Jiaxing Zhongcheng Environmental Protection Technology Co., Ltd.

[0041] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the mass of tetrabutyl titanate accounts for 0.5% of the total mass of pentaerythritol trioleate, tri-n-butyl borate, and oleylamine.

[0042] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the mass of 2,6-di-tert-butyl-p-cresol accounts for 0.30% of the total mass of pentaerythritol trioleate, tri-n-butyl borate, and oleylamine.

[0043] In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the reaction pressure is controlled at -0.085 MPa during the reaction process of heating from 80℃ to 140℃ and holding at that temperature.

[0044] The post-treatment described in the preparation method of boron-nitrogen modified pentaerythritol trioleate is as follows: after the reaction is completed, the mixture is distilled under reduced pressure at 140℃ and -0.095MPa for 35 min, followed by vacuum filtration to obtain boron-nitrogen modified pentaerythritol trioleate.

[0045] The preparation method of sulfur-modified n-butyl oleate is as follows: under nitrogen protection, n-butyl oleate and methyl 3-mercaptopropionate are added to a reaction vessel and stirred at 60°C for 20 min. Azobisisobutyronitrile is added and stirring is continued for 10 min. The temperature is raised to 85°C within 50 min and kept at that temperature for 3.5 h. After the reaction is completed, the temperature is lowered to 70°C and 2,6-di-tert-butyl-p-cresol is added and stirred for 10 min. Finally, the temperature is lowered to 60°C and vacuum filtered while hot to prepare sulfur-modified n-butyl oleate.

[0046] In the preparation method of sulfur-modified n-butyl oleate, the mass ratio of n-butyl oleate, methyl 3-mercaptopropionate, and azobisisobutyronitrile is 100:38:1.0, and the mass of 2,6-di-tert-butyl-p-cresol accounts for 0.1% of the mass of n-butyl oleate.

[0047] In the preparation method of sulfur-modified n-butyl oleate, the pressure of hot vacuum filtration is -0.08 MPa.

[0048] Example 1

[0049] The lubricating oil anti-wear agent described in Example 1 is composed of the following raw materials by mass percentage: 2.0% sulfur-modified n-butyl oleate, 0.49% molybdenum dialkyl dithiocarbamate, 0.45% ammonium di(2-ethylhexyl) phosphate, 5.4% boron-nitrogen-modified pentaerythritol trioleate, 1.9% detergent-dispersant, 0.5% antioxidant, 0.3% pour point depressant, 0.1% antifoaming agent, and the balance being base oil.

[0050] The cleaning and dispersing agent is a mixture of calcium petroleum sulfonate and magnesium petroleum sulfonate, with a mass ratio of 1.88:1. The manufacturer of calcium petroleum sulfonate is Jinzhou Chenghua New Materials Co., Ltd., and its model number is T103. The manufacturer of magnesium petroleum sulfonate is Jinzhou Shengda Chemical Co., Ltd., and its model number is T107.

[0051] The antioxidant is a mixture of dioctyl diphenylamine and 2,6-di-tert-butyl-p-cresol, with a mass ratio of 2:1.

[0052] The pour point depressant is polymethyl methacrylate, and the antifoaming agent is a 1% polydimethylsiloxane solution. 1g of polydimethylsiloxane is added to 99g of polyalphaolefin PAO 6 and stirred at 60℃ for 30min to prepare a 1% polydimethylsiloxane solution.

[0053] The base oil is a mixture of polyalphaolefin (PAO) 6 and polyalphaolefin (PAO) 40, wherein the mass ratio of PAO 6 to PAO 40 is 2.3:1. Both PAO 40 and PAO 6 are manufactured by Shenzhen Huashengyuan Petroleum Technology Co., Ltd.

[0054] The preparation method of the lubricating oil anti-wear agent described in Example 1 consists of the following steps:

[0055] (1) Under a nitrogen atmosphere, add base oil to the reaction apparatus and mix well;

[0056] (2) Add sulfur-modified n-butyl oleate, molybdenum dialkyl dithiocarbamate, ammonium di(2-ethylhexyl) phosphate and boron-nitrogen-modified pentaerythritol trioleate to the base oil in step (1) and stir to mix well.

[0057] (3) Add the cleaning and dispersing agent and the antioxidant to the reaction system of step (2) in sequence and stir until well mixed;

[0058] (4) Add pour point depressant to the mixture prepared in step (3) and stir for 16 min, then add antifoaming agent and stir for 11 min, and finally after post-treatment, the lubricating oil anti-wear agent is prepared.

[0059] Wherein: the mixing temperature in step (1) is 61℃ and the mixing time is 33min.

[0060] In step (2), the stirring temperature is 61°C. After adding sulfur-modified n-butyl oleate and stirring for 11 min, molybdenum dialkyl dithiocarbamate is added and stirred for 11 min. Then, ammonium di(2-ethylhexyl) phosphate is added and stirred for 11 min. After that, boron-nitrogen-modified pentaerythritol trioleate is added and stirred for another 11 min.

[0061] In step (3), the mixing temperature is 61°C. Add the cleaning and dispersing agent and mix for 33 minutes. Then add the antioxidant and mix for 21 minutes.

[0062] In step (4), pour point depressant is added at 61°C, and antifoaming agent is added after cooling to 49°C.

[0063] During the mixing process of steps (1)-(4), nitrogen gas is continuously introduced to maintain the system pressure at 0.05 MPa.

[0064] The post-treatment described in step (4) involves standing at 59°C under nitrogen protection for 11 minutes to degas, followed by vacuum filtration at a pressure of -0.08 MPa. The filtrate is then collected to prepare the lubricating oil anti-wear agent.

[0065] Example 2

[0066] The lubricating oil anti-wear agent described in Example 2 is composed of the following raw materials by mass percentage: 1.9% sulfur-modified n-butyl oleate, 0.50% molybdenum dialkyl dithiocarbamate, 0.5% ammonium di(2-ethylhexyl) phosphate, 5.3% boron-nitrogen-modified pentaerythritol trioleate, 1.8% detergent-dispersant, 0.4% antioxidant, 0.3% pour point depressant, 0.1% antifoaming agent, and the balance being base oil.

[0067] The cleaning and dispersing agent is a mixture of calcium petroleum sulfonate and magnesium petroleum sulfonate, with a mass ratio of 1.88:1. The manufacturer of calcium petroleum sulfonate is Jinzhou Chenghua New Materials Co., Ltd., and its model number is T103. The manufacturer of magnesium petroleum sulfonate is Jinzhou Shengda Chemical Co., Ltd., and its model number is T107.

[0068] The antioxidant is a mixture of dioctyl diphenylamine and 2,6-di-tert-butyl-p-cresol, with a mass ratio of 2:1.

[0069] The pour point depressant is polymethyl methacrylate, and the antifoaming agent is a 1% polydimethylsiloxane solution. 1g of polydimethylsiloxane is added to 99g of polyalphaolefin PAO 6 and stirred at 60℃ for 30min to prepare a 1% polydimethylsiloxane solution.

[0070] The base oil is a mixture of polyalphaolefin (PAO) 6 and polyalphaolefin (PAO) 40, wherein the mass ratio of PAO 6 to PAO 40 is 2.3:1. Both PAO 40 and PAO 6 are manufactured by Shenzhen Huashengyuan Petroleum Technology Co., Ltd.

[0071] The preparation method of the lubricating oil anti-wear agent described in Example 2 consists of the following steps:

[0072] (1) Under a nitrogen atmosphere, add base oil to the reaction apparatus and mix well;

[0073] (2) Add sulfur-modified n-butyl oleate, molybdenum dialkyl dithiocarbamate, ammonium di(2-ethylhexyl) phosphate and boron-nitrogen-modified pentaerythritol trioleate to the base oil in step (1) and stir to mix well.

[0074] (3) Add the cleaning and dispersing agent and the antioxidant to the reaction system of step (2) in sequence and stir until well mixed;

[0075] (4) Add pour point depressant to the mixture prepared in step (3) and stir for 15 min, then add antifoaming agent and stir for 10 min, and finally after post-treatment, the lubricating oil anti-wear agent is prepared.

[0076] Wherein: the mixing temperature in step (1) is 62℃ and the mixing time is 35min.

[0077] In step (2), the mixing temperature is 62℃. After adding sulfur-modified n-butyl oleate and stirring for 10 min, molybdenum dialkyl dithiocarbamate is added and stirred for 10 min. Then, ammonium di(2-ethylhexyl) phosphate is added and stirred for 10 min. After that, boron-nitrogen-modified pentaerythritol trioleate is added and stirred for another 10 min.

[0078] In step (3), the mixing temperature is 62°C. Add the cleaning and dispersing agent and mix for 30 minutes, then add the antioxidant and mix for 20 minutes.

[0079] In step (4), pour point depressant is added at 62°C, and antifoaming agent is added after cooling to 50°C.

[0080] During the mixing process of steps (1)-(4), nitrogen gas is continuously introduced to maintain the system pressure at 0.05 MPa.

[0081] The post-treatment described in step (4) involves standing at 60°C under nitrogen protection for 10 minutes to degas, followed by vacuum filtration at a pressure of -0.08 MPa, collecting the filtrate, and preparing the lubricating oil anti-wear agent.

[0082] Example 3

[0083] The lubricating oil anti-wear agent described in Example 3 is composed of the following raw materials by mass percentage: 2.1% sulfur-modified n-butyl oleate, 0.48% molybdenum dialkyl dithiocarbamate, 0.40% ammonium di(2-ethylhexyl) phosphate, 5.5% boron-nitrogen-modified pentaerythritol trioleate, 2.0% detergent-dispersant, 0.6% antioxidant, 0.3% pour point depressant, 0.1% antifoaming agent, and the balance being base oil.

[0084] The cleaning and dispersing agent is a mixture of calcium petroleum sulfonate and magnesium petroleum sulfonate, with a mass ratio of 1.88:1. The manufacturer of calcium petroleum sulfonate is Jinzhou Chenghua New Materials Co., Ltd., and its model number is T103. The manufacturer of magnesium petroleum sulfonate is Jinzhou Shengda Chemical Co., Ltd., and its model number is T107.

[0085] The antioxidant is a mixture of dioctyl diphenylamine and 2,6-di-tert-butyl-p-cresol, with a mass ratio of 2:1.

[0086] The pour point depressant is polymethyl methacrylate, and the antifoaming agent is a 1% polydimethylsiloxane solution. 1g of polydimethylsiloxane is added to 99g of polyalphaolefin PAO 6 and stirred at 60℃ for 30min to prepare a 1% polydimethylsiloxane solution.

[0087] The base oil is a mixture of polyalphaolefin (PAO) 6 and polyalphaolefin (PAO) 40, wherein the mass ratio of PAO 6 to PAO 40 is 2.3:1. Both PAO 40 and PAO 6 are manufactured by Shenzhen Huashengyuan Petroleum Technology Co., Ltd.

[0088] The preparation method of the lubricating oil anti-wear agent described in Example 3 consists of the following steps:

[0089] (1) Under a nitrogen atmosphere, add base oil to the reaction apparatus and mix well;

[0090] (2) Add sulfur-modified n-butyl oleate, molybdenum dialkyl dithiocarbamate, ammonium di(2-ethylhexyl) phosphate and boron-nitrogen-modified pentaerythritol trioleate to the base oil in step (1) and stir to mix well.

[0091] (3) Add the cleaning and dispersing agent and the antioxidant to the reaction system of step (2) in sequence and stir until well mixed;

[0092] (4) Add pour point depressant to the mixture prepared in step (3) and stir for 17 min, then add antifoaming agent and stir for 13 min, and finally after post-treatment, the lubricating oil anti-wear agent is prepared.

[0093] Wherein: the mixing temperature in step (1) is 60℃ and the mixing time is 30min.

[0094] In step (2), the mixing temperature is 60℃. After adding sulfur-modified n-butyl oleate and stirring for 12 min, molybdenum dialkyl dithiocarbamate is added and stirred for 12 min. Then, ammonium di(2-ethylhexyl) phosphate is added and stirred for 12 min. After that, boron-nitrogen-modified pentaerythritol trioleate is added and stirred for another 12 min.

[0095] In step (3), the mixing temperature is 60°C. Add the cleaning and dispersing agent and mix for 35 minutes. Then add the antioxidant and mix for 23 minutes.

[0096] In step (4), pour point depressant is added at 60°C, and antifoaming agent is added after cooling to 48°C.

[0097] During the mixing process of steps (1)-(4), nitrogen gas is continuously introduced to maintain the system pressure at 0.05 MPa.

[0098] The post-treatment described in step (4) involves standing at 58°C under nitrogen protection for 12 minutes to degas, followed by vacuum filtration at a pressure of -0.08 MPa. The filtrate is then collected to prepare the lubricating oil anti-wear agent.

[0099] Comparative Example 1

[0100] The preparation method of the lubricating oil anti-wear agent described in Comparative Example 1 is the same as that in Example 1, the only difference being the composition of the raw materials. The lubricating oil anti-wear agent described in Comparative Example 1, by mass percentage, consists of the following raw materials: 0.49% molybdenum dialkyl dithiocarbamate, 0.45% ammonium di(2-ethylhexyl) phosphate, 5.4% boron-nitrogen modified pentaerythritol trioleate, 1.9% detergent-dispersant, 0.5% antioxidant, 0.3% pour point depressant, 0.1% antifoaming agent, with base oil as the balance.

[0101] Comparative Example 2

[0102] The preparation method of the lubricating oil anti-wear agent described in Comparative Example 2 is the same as that in Example 1, the only difference being the composition of the raw materials. The lubricating oil anti-wear agent described in Comparative Example 2, by mass percentage, consists of the following raw materials: 2.0% sulfur-modified n-butyl oleate, 0.49% molybdenum dialkyl dithiocarbamate, 0.45% ammonium di(2-ethylhexyl) phosphate, 1.9% detergent-dispersant, 0.5% antioxidant, 0.3% pour point depressant, 0.1% antifoaming agent, with base oil as the balance.

[0103] The anti-wear agents for lubricating oils prepared in Examples 1-3 and Comparative Examples 1-2 were added to solvent oil (wherein, the solvent oil was a mixture of polyalphaolefin PAO 6 and polyalphaolefin PAO 40, with a mass ratio of 2.3:1, and both polyalphaolefin PAO 40 and polyalphaolefin PAO 6 were manufactured by Shenzhen Huashengyuan Petroleum Technology Co., Ltd.). The mass percentage of the anti-wear agent was controlled at 3.0% based on the total mass of the test oil. The mixture was then stirred and mixed at 60℃ and 300 r / min for 20 min to obtain a homogeneous test oil. Performance tests were then conducted on the oil. The wear scar diameter was measured at 75℃, 1200 r / min, for 60 min, and at 392 N. The comprehensive test results are shown in Table 1 below.

[0104] Table 1. Test results of anti-wear properties of lubricating oil

[0105]

[0106] As shown in Table 1, the application effect of the lubricating oil anti-wear agents prepared in Examples 1-3 is significantly better than that of Comparative Examples 1-2. Due to the absence of either sulfur-modified n-butyl oleate or boron-nitrogen-modified pentaerythritol trioleate in the added lubricating oil anti-wear agents of Comparative Examples 1-2, the anti-wear performance under medium and extreme pressure conditions is greatly reduced.

[0107] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A lubricating oil anti-wear agent, characterized in that: The product, by mass percentage, is composed of the following raw materials: sulfur-modified n-butyl oleate 1.9-2.1%, molybdenum dialkyl dithiocarbamate 0.48-0.50%, ammonium di(2-ethylhexyl) phosphate ester 0.4-0.5%, boron-nitrogen-modified pentaerythritol trioleate 5.3-5.5%, detergent-dispersant 1.8-2.0%, antioxidant 0.4-0.6%, pour point depressant 0.3%, antifoaming agent 0.1%, and base oil as the balance. The boron-nitrogen-modified pentaerythritol trioleate is prepared by: under a nitrogen atmosphere... Pentaerythritol trioleate, tri-n-butyl borate, tetrabutyl titanate, and 2,6-di-tert-butyl-p-cresol were added to the reaction apparatus and stirred until homogeneous. The mixture was heated to 93°C and reacted for 2 hours. The temperature was then lowered to 40°C and oil amine was added dropwise. After the addition was complete, the temperature was raised to 80°C and maintained for 1 hour. Then, the temperature was raised to 100°C at a rate of 1.1°C / min and maintained for 1.2 hours. Finally, the temperature was raised to 140°C at a rate of 1.1°C / min and maintained for 1.5 hours. After the reaction was completed, boron-nitrogen modified pentaerythritol trioleate was prepared through post-processing. In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the molar ratio of pentaerythritol trioleate, tributyl borate, and oleylamine is 1:1.05:2.

0. In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the mass of tetrabutyl titanate accounts for 0.5% of the sum of the masses of pentaerythritol trioleate, tri-n-butyl borate, and oleylamine. The preparation method of sulfur-modified n-butyl oleate is as follows: under nitrogen protection, n-butyl oleate and methyl 3-mercaptopropionate are added to a reaction vessel and stirred at 60°C for 20 min. Azobisisobutyronitrile is added and stirring is continued for 10 min. The temperature is raised to 85°C within 50 min and kept at that temperature for 3.5 h. After the reaction is completed, the temperature is lowered to 70°C and 2,6-di-tert-butyl-p-cresol is added and stirred for 10 min. Finally, the temperature is lowered to 60°C and vacuum filtered while hot to prepare sulfur-modified n-butyl oleate.

2. The lubricating oil anti-wear agent according to claim 1, characterized in that: In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the stirring and mixing temperature is 25℃ and the stirring and mixing time is 13min. In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the temperature is raised to 93℃ and the reaction is carried out for 2 hours, and the reaction pressure is -0.085MPa.

3. The lubricating oil anti-wear agent according to claim 1, characterized in that: In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the mass of 2,6-di-tert-butyl-p-cresol accounts for 0.30% of the total mass of pentaerythritol trioleate, tri-n-butyl borate, and oleylamine. In the preparation method of boron-nitrogen modified pentaerythritol trioleate, the reaction pressure is controlled at -0.085 MPa during the reaction process of heating from 80℃ to 140℃ and holding at that temperature. The post-treatment described in the preparation method of boron-nitrogen modified pentaerythritol trioleate is as follows: after the reaction is completed, the mixture is distilled under reduced pressure at 140℃ and -0.095MPa for 35 min, followed by vacuum filtration to obtain boron-nitrogen modified pentaerythritol trioleate.

4. The lubricating oil anti-wear agent according to claim 1, characterized in that: In the preparation method of sulfur-modified n-butyl oleate, the mass ratio of n-butyl oleate, methyl 3-mercaptopropionate, and azobisisobutyronitrile is 100:38:1.0, and the mass of 2,6-di-tert-butyl-p-cresol accounts for 0.1% of the mass of n-butyl oleate.

5. The lubricating oil anti-wear agent according to claim 1, characterized in that: In the preparation method of sulfur-modified n-butyl oleate, the pressure of hot vacuum filtration is -0.08 MPa.

6. The lubricating oil anti-wear agent according to claim 1, characterized in that: The detergent dispersant is a mixture of calcium petroleum sulfonate and magnesium petroleum sulfonate, with a mass ratio of calcium petroleum sulfonate to magnesium petroleum sulfonate of 1.88:

1. The antioxidant is a mixture of dioctyl diphenylamine and 2,6-di-tert-butyl-p-cresol, with a mass ratio of dioctyl diphenylamine to 2,6-di-tert-butyl-p-cresol of 2:

1. The pour point depressant is polymethyl methacrylate, and the antifoaming agent is a 1% polydimethylsiloxane solution. 1g of polydimethylsiloxane is added to 99g of polyalphaolefin PAO6 and stirred at 60℃ for 30min to prepare a 1% polydimethylsiloxane solution. The base oil is a mixture of polyalphaolefin PAO6 and polyalphaolefin PAO40, wherein the mass ratio of polyalphaolefin PAO6 to polyalphaolefin PAO40 is 2.3:

1.

7. A method for preparing the lubricating oil anti-wear agent according to claim 1, characterized in that: It consists of the following steps: (1) Under a nitrogen atmosphere, add base oil to the reaction apparatus and mix well; (2) Add sulfur-modified n-butyl oleate, molybdenum dialkyl dithiocarbamate, ammonium di(2-ethylhexyl) phosphate and boron-nitrogen-modified pentaerythritol trioleate to the base oil in step (1) and stir to mix well. (3) Add the cleaning and dispersing agent and the antioxidant to the reaction system of step (2) in sequence and stir until well mixed; (4) Add pour point depressant to the mixture prepared in step (3) and stir for 15-17 min, then add antifoaming agent and stir for 10-13 min, and finally after post-treatment, the lubricating oil anti-wear agent is prepared.

8. The method for preparing the lubricating oil anti-wear agent according to claim 7, characterized in that: In step (1), the mixing temperature is 60-62℃ and the mixing time is 30-35min; In step (2), the stirring temperature is 60-62℃. After adding sulfur-modified n-butyl oleate and stirring for 10-12 min, molybdenum dialkyl dithiocarbamate is added and stirred for 10-12 min. Then, ammonium di(2-ethylhexyl) phosphate is added and stirred for 10-12 min. After that, boron-nitrogen-modified pentaerythritol trioleate is added and stirred for another 10-12 min. In step (3), the mixing temperature is 60-62℃. Add the cleaning and dispersing agent and mix for 30-35 minutes. Then add the antioxidant and mix for 20-23 minutes.

9. The method for preparing the lubricating oil anti-wear agent according to claim 7, characterized in that: In step (4), pour point depressant is added at 60-62℃, and antifoaming agent is added after cooling to 48-50℃; During the mixing process in steps (1)-(4), nitrogen gas is continuously introduced to maintain the system pressure at 0.05 MPa; The post-treatment described in step (4) involves standing at 58-60℃ under nitrogen protection for 10-12 minutes to degas, followed by vacuum filtration at a pressure of -0.08 MPa, collecting the filtrate, and preparing the lubricating oil anti-wear agent.

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