A lubricating grease composition, its preparation and use

Abstract

This invention relates to the field of lubricating grease technology, and more particularly to a lubricating grease composition, its preparation method, and its application. The lubricating grease composition comprises: a base oil, a thickener, and additives; the base oil is composed of alkyl naphthalene synthetic oil and ester synthetic oil; the additives include extreme pressure anti-wear agents; the extreme pressure anti-wear agents include at least two selected from nano-lanthanum fluoride, nano-cerium oxide, calcium silicate, triphenyl phosphate, graphite, and molybdenum disulfide. The wind turbine lubricating grease provided by this invention not only exhibits excellent high and low temperature performance and superior oxidation resistance, but also possesses better lubricity and adhesion, effectively reducing friction and wear on equipment. It can adapt to the operating requirements of wind turbine equipment under harsh conditions such as extreme temperatures, humidity, and salt spray, avoiding equipment failures and downtime caused by poor lubrication, and significantly extending the service life of wind turbine bearings.

Description

Technical Field

[0001] This invention relates to the field of lubricating grease technology, and in particular to a lubricating grease composition, its preparation method, and its application. Background Technology

[0002] Energy is a vital pillar of the modern economy and a crucial foundation for industrial development. With the rapid development of my country's industry, the excessive consumption of conventional energy sources such as coal and oil has led to increasingly prominent energy shortages and environmental pollution problems. Developing clean and renewable energy has become a core part of the national energy strategy. Wind power generation is an important sector for achieving energy transformation and upgrading, a key area for renewable energy development, and a preferred measure for promoting energy structure adjustment. As one of the most mature, scalable, and commercially viable renewable energy generation methods, wind power is widely distributed globally and has vast reserves. Simultaneously, with the continuous maturation of wind power-related technologies and the upgrading of equipment, the global wind power industry is developing rapidly. Lubricating grease, as a crucial component for maintaining the healthy operation of wind turbine units, directly affects the operating efficiency and lifespan of wind power equipment.

[0003] Wind power equipment is typically installed outdoors in harsh environments, such as extreme temperatures, high humidity, and strong winds and sandstorms. These harsh conditions place extremely high demands on the performance of lubricating greases, requiring them to possess excellent high and low temperature resistance, corrosion resistance, and extreme pressure anti-wear properties. Furthermore, the long maintenance cycles and harsh operating environments of wind power equipment place even higher demands on the service life and maintenance frequency of lubricating greases. However, currently available wind power lubricating greases often fail to fully meet these requirements, leading to frequent equipment malfunctions and impacting the stable operation of wind farms. Therefore, improving the extreme pressure anti-wear properties and lubrication life of lubricating greases can reduce grease usage, thereby reducing environmental pollution, extending grease replacement cycles, and lowering overall application costs, which has significant practical and economic value for society as a whole.

[0004] Chinese patent application CN109536249 effectively improves the performance of gear grease by adding hydroisomerized naphthenic base oil and Fischer-Tropsch synthetic base oil, and ensures that the gear grease still has good thermal oxidation stability under harsh environments and operating conditions such as low temperature (-30℃~-40℃) and high temperature (200℃). However, the resulting grease is only suitable for yaw system gears. Chinese patent application CN113174286A uses a fully synthetic base oil formula and active bentonite as a thickener, which improves the high and low temperature performance of the grease, but its anti-wear performance needs further improvement. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a grease composition, its preparation method, and its application, which can improve the service life of the grease and meet the lubrication requirements of wind power equipment in harsh environments.

[0006] Based on this, the present invention has the following technical solution:

[0007] In a first aspect, the present invention provides a lubricating grease composition comprising: a base oil, a thickener, and an additive; wherein the base oil is composed of an alkyl naphthalene synthetic oil and an ester synthetic oil; and the additive comprises an extreme pressure anti-wear agent; wherein the extreme pressure anti-wear agent comprises at least two of nano-lanthanum fluoride, nano-cerium oxide, calcium silicate, triphenyl phosphate, graphite, and molybdenum disulfide.

[0008] This invention has found that the addition of the above-mentioned extrusion anti-wear agent can improve the friction-reducing and anti-wear performance of grease to a certain extent. It not only reduces the use of traditional anti-wear agents containing environmentally unfriendly elements such as sulfur and phosphorus, thus improving environmental performance, but also extends the service life of wind power equipment, and has a good market prospect.

[0009] Preferably, the extreme pressure anti-wear agent comprises a mixture of nano-lanthanum fluoride, nano-cerium oxide, and calcium silicate.

[0010] Preferably, the extreme pressure anti-wear agent comprises a mixture of nano-lanthanum fluoride, nano-cerium oxide, and calcium silicate in a mass ratio of 0.5~1.5:0.5~1.5:0.5~1.

[0011] Preferably, the extreme pressure anti-wear agent in the lubricating oil composition is used in an amount of 1 to 3 wt%.

[0012] Preferably, the mass ratio of the alkylnaphthalene synthetic oil to the ester synthetic oil is 1-3:1-3.

[0013] Preferably, the alkyl naphthalene synthetic oil includes one or more of AN8, AN23 and AN30; the ester synthetic oil includes one or more of pentaerythritol ester, trimethylolpropane trioleate, dioctyl adipate and dioctyl phthalate; more preferably, the alkyl naphthalene synthetic oil is AN23 and the ester synthetic oil is trimethylolpropane trioleate.

[0014] In this invention, the base oils using the above-mentioned mixing method can better improve the high and low temperature performance of the lubricating grease.

[0015] Preferably, the thickener is a composite calcium soap thickener, which is obtained by reacting fatty acids, small molecule acids and calcium hydroxide; wherein the fatty acids include one or more of palmitic acid, myristic acid and lauric acid, and the small molecule acids include one or more of boric acid, phosphoric acid and acetic acid.

[0016] More preferably, the fatty acid is lauric acid, and the small molecule acid is boric acid.

[0017] More preferably, the mass ratio of the fatty acid to the small molecule acid is 3 to 6:1.

[0018] Preferably, the additive includes an antioxidant, which includes one or more of octylbutyldiphenylamine, diisooctyldiphenylamine, 2-naphthol, and dodecyl selenide; more preferably, dodecyl selenide.

[0019] Preferably, the rust inhibitor includes one or more of dodecenyl succinic acid, sodium petroleum sulfonate, and zinc naphthenate; more preferably, it is dodecenyl succinic acid.

[0020] Preferably, the grease composition comprises the following components in parts by weight:

[0021] 72-90 parts base oil;

[0022] Thickener 7-15 parts;

[0023] 1-3 parts of extreme pressure anti-wear agent;

[0024] Antioxidant 0.5 to 2 parts;

[0025] 0.5 to 1.5 parts of rust and corrosion inhibitor.

[0026] In this invention, the grease uses a scientifically designed base oil, combined with special extreme pressure anti-wear agents and high-performance antioxidants, to form a good protective film on the bearing surface, reduce wear between bearings, improve the service life of the grease, and meet the lubrication requirements of wind power equipment in harsh environments.

[0027] In a second aspect, the present invention provides a method for preparing the aforementioned lubricating grease composition, comprising the following steps:

[0028] 50–70 wt% of the base oil is mixed with fatty acids and small molecule acids, and heated to 85–90°C to obtain a fatty acid solution. After heating to 95–100°C, 30–50 wt% of calcium hydroxide solution is added to initiate a saponification reaction. The temperature is then raised to 130–140°C and maintained. After drainage, the temperature is further raised to the highest refining temperature of 210–220°C and maintained. The remaining base oil is added to cool down the mixture. After cooling to below 80°C, additives are added for homogenization treatment, followed by degassing to obtain a lubricating grease composition.

[0029] In a preferred embodiment of the present invention, the method for preparing the lubricating grease composition includes the following steps:

[0030] First, weigh 50%–70% of alkylnaphthalene synthetic oil and ester synthetic oil into a reaction vessel, add fatty acids and small molecule acids, and heat to 85–90°C to obtain a fatty acid solution. Add 30%–50% calcium hydroxide solution for saponification. The reaction time is 50–60 minutes, and the temperature is controlled at 95–100°C before adding the remaining calcium hydroxide solution dropwise. The temperature is then raised to 130–140°C and held for 60–90 minutes. After drainage, the temperature is further raised to the highest refining temperature of 210–220°C and held for 3–5 minutes. Add the remaining base oil and cool down. When the temperature drops below 80°C, add extreme pressure anti-wear agent, antioxidant, rust inhibitor, and corrosion inhibitor. After stirring for 30–40 minutes, homogenize the material using a three-roll mill and degas it to obtain the finished lubricating grease composition.

[0031] Thirdly, the present invention provides the application of the lubricating grease composition in wind power equipment.

[0032] This invention provides a lubricating grease composition, its preparation method, and its application. By optimizing the composition of the base oil and additives, the components work synergistically to significantly improve the extreme pressure anti-wear, anti-oxidation, and anti-corrosion / rust-preventing properties of the grease. This enables it to meet the requirements of wind turbine bearings, especially under harsh environmental and operational conditions such as sandstorms, rain, snow, and seawater salt spray corrosion. In particular, the addition of nano-lanthanum fluoride and nano-cerium oxide improves the friction-reducing and anti-wear properties of the grease to a certain extent, reduces the use of traditional anti-wear agents containing environmentally unfriendly elements such as sulfur and phosphorus, improves environmental performance, extends the service life of wind power equipment, and has excellent market prospects. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] Unless otherwise specified, all raw materials used in the examples and comparative examples are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0035] Example 1

[0036] This embodiment provides a lubricating grease composition, the preparation method of which includes the following steps:

[0037] First, weigh 30 parts of AN23 and 18 parts of trimethylolpropane trioleate into a reaction vessel, add 8 parts of lauric acid and 2 parts of boric acid, and heat to 85°C to obtain a fatty acid solution. Add 2 parts of calcium hydroxide solution for saponification reaction. The reaction time is 50 minutes, and the temperature is controlled at 95-100°C. Start adding the remaining 3 parts of calcium hydroxide solution dropwise. Heat to 135°C and hold for 60 minutes. After drainage, continue heating to the highest refining temperature of 220°C and hold for 5 minutes. Add the remaining 23.5 parts of AN23 and 10 parts of trimethylolpropane trioleate, and cool down to 80°C. Add 1 part of nano-lanthanum fluoride, 0.5 parts of nano-cerium oxide, 1 part of calcium silicate, 0.5 parts of dodecyl selenide, and 0.5 parts of dodecenyl succinic acid. Stir for 30 minutes, then homogenize the material through a three-roll mill and degas to obtain the finished lubricating grease.

[0038] Example 2

[0039] This embodiment provides a lubricating grease composition, the preparation method of which includes the following steps:

[0040] First, weigh 35 parts of AN23 and 18 parts of trimethylolpropane trioleate into a reaction vessel, add 7 parts of lauric acid and 2 parts of boric acid, and heat to 85°C to obtain a fatty acid solution. Add 2 parts of calcium hydroxide solution for saponification reaction. The reaction time is 60 minutes, and the temperature is controlled at 95-100°C. Start adding the remaining 3 parts of calcium hydroxide solution dropwise. Heat to 130°C and hold for 60 minutes. After drainage, continue heating to the highest refining temperature of 210°C and hold for 5 minutes. Add the remaining 15 parts of AN23 and 13 parts of trimethylolpropane trioleate and cool down. Cool to 80°C and add 1.5 parts of nano-lanthanum fluoride, 0.5 parts of nano-cerium oxide, 1 part of calcium silicate, 1 part of dodecyl selenide, and 1 part of dodecenyl succinic acid. Stir for 30 minutes, then homogenize the material through a three-roll mill and degas to obtain the finished lubricating grease.

[0041] Example 3

[0042] This embodiment provides a lubricating grease composition, the preparation method of which includes the following steps:

[0043] First, weigh 28 parts of AN23 and 25 parts of trimethylolpropane trioleate into a reaction vessel, add 6 parts of lauric acid and 1 part of boric acid, and heat to 85°C to obtain a fatty acid solution. Add 2 parts of calcium hydroxide solution for saponification reaction. The reaction time is 60 minutes, and the temperature is controlled at 95-100°C. Start adding the remaining 4 parts of calcium hydroxide solution dropwise; heat to 130°C and hold for 60 minutes; after drainage, continue heating to the highest refining temperature of 210°C and hold for 5 minutes. Add the remaining 10 parts of AN23 and 20 parts of trimethylolpropane trioleate and cool down. When the temperature drops to 80°C, add 1 part of nano-lanthanum fluoride, 1.5 parts of nano-cerium oxide, 0.5 parts of calcium silicate, 0.5 parts of dodecyl selenide, and 0.5 parts of dodecenyl succinic acid. After stirring for 30 minutes, homogenize the material through a three-roll mill and degas to obtain the finished lubricating grease.

[0044] Example 4

[0045] This embodiment provides a lubricating grease composition, the preparation method of which includes the following steps:

[0046] First, weigh 15 parts of AN23 and 35 parts of trimethylolpropane trioleate into a reaction vessel, add 8 parts of lauric acid and 2 parts of boric acid, and heat to 85°C to obtain a fatty acid solution. Add 2 parts of calcium hydroxide solution for saponification reaction. The reaction time is 55 minutes, and the temperature is controlled at 95-100°C. Start adding the remaining 3 parts of calcium hydroxide solution dropwise. Heat to 140°C and hold for 60 minutes. After drainage, continue heating to the highest refining temperature of 210°C and hold for 5 minutes. Add the remaining 15 parts of AN23 and 16 parts of trimethylolpropane trioleate and cool down. Cool to 80°C and add 0.5 parts of nano-lanthanum fluoride, 1 part of nano-cerium oxide, 0.5 parts of calcium silicate, 1 part of dodecyl selenide, and 1 part of dodecenyl succinic acid. Stir for 30 minutes, then homogenize the material through a three-roll mill and degas to obtain the finished grease.

[0047] Example 5

[0048] This embodiment provides a lubricating grease composition, the preparation method of which includes the following steps:

[0049] First, weigh 20 parts of AN23 and 32 parts of trimethylolpropane trioleate into a reaction vessel, add 5 parts of lauric acid and 2 parts of boric acid, and heat to 85°C to obtain a fatty acid solution. Add 1.5 parts of calcium hydroxide solution for saponification reaction. The reaction time is 55 minutes, and the temperature is controlled at 95-100°C. Start adding the remaining 2.5 parts of calcium hydroxide solution dropwise; heat to 140°C and hold for 60 minutes; after drainage, continue heating to the highest refining temperature of 210°C and hold for 5 minutes. Add the remaining 10.5 parts of AN23 and 23 parts of trimethylolpropane trioleate, cool down, and add 0.5 parts of nano-lanthanum fluoride, 0.5 parts of nano-cerium oxide, 0.5 parts of calcium silicate, 1.5 parts of dodecyl selenide, and 0.5 parts of dodecenyl succinic acid to 80°C. After stirring for 30 minutes, homogenize the material through a three-roll mill and degas to obtain the finished lubricating grease.

[0050] Comparative Example 1

[0051] This comparative example provides a lubricating grease composition, the preparation method of which includes the following steps:

[0052] First, weigh 55 parts of AN23 into a reaction vessel, add 8 parts of lauric acid and 2 parts of boric acid, and heat to 85℃ to obtain a fatty acid solution. Add 2 parts of calcium hydroxide solution for saponification reaction. The reaction time is 55 minutes, and the temperature is controlled at 95-100℃. Start adding the remaining 4 parts of calcium hydroxide solution dropwise. Heat to 130℃ and hold for 60 minutes. After drainage, continue heating to the highest refining temperature of 220℃ and hold for 5 minutes. Add the remaining 25 parts of AN23 and cool down. Cool to 80℃ and add 1 part of nano-lanthanum fluoride, 0.5 parts of nano-cerium oxide, 0.5 parts of calcium silicate, 1 part of dodecyl selenide, and 1 part of dodecenyl succinic acid. Stir for 30 minutes, then homogenize the material through a three-roll mill and degas to obtain the finished lubricating grease.

[0053] Comparative Example 2

[0054] First, weigh 45 parts of trimethylolpropane trioleate into a reaction vessel, add 7 parts of lauric acid and 2 parts of boric acid, and heat to 85°C to obtain a fatty acid solution. Add 3 parts of calcium hydroxide solution for saponification reaction. The reaction time is 55 minutes, and the temperature is controlled at 95-100°C. Start adding the remaining 4 parts of calcium hydroxide solution dropwise. Heat to 140°C and hold for 60 minutes. After drainage, continue heating to the highest refining temperature of 210°C and hold for 5 minutes. Add the remaining 34 parts of trimethylolpropane trioleate and cool down. When the temperature drops to 80°C, add 2 parts of nano-cerium oxide, 0.5 parts of calcium silicate, 1.5 parts of dodecyl selenide, and 1 part of dodecenyl succinic acid. Stir for 30 minutes, then homogenize the material through a three-roll mill and degas to obtain the finished lubricating grease.

[0055] Test case

[0056] The performance of the greases prepared in the above embodiments and comparative examples was tested, and the test results are shown in Table 1.

[0057] Table 1

[0058]

[0059] As can be seen from the data in Table 1, the greases prepared in the embodiments of the present invention all exhibit excellent extreme pressure anti-wear properties, good antioxidant properties, and low-temperature start-up performance, fully meeting the requirements and operating conditions of wind power lubricating greases. Meanwhile, the addition of nano-lanthanum fluoride and nano-cerium oxide improves the friction-reducing and anti-wear properties of the grease to a certain extent, reduces the use of traditional anti-wear agents containing environmentally unfriendly elements such as sulfur and phosphorus, improves environmental performance, extends the service life of wind power equipment, and has a promising market prospect.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lubricating grease composition, characterized in that, include: The base oil, thickener, and additives; the base oil is composed of alkyl naphthalene synthetic oil and ester synthetic oil; the additives include extreme pressure anti-wear agents, antioxidants, and rust inhibitors; the extreme pressure anti-wear agent is a mixture of nano-lanthanum fluoride, nano-cerium oxide, and calcium silicate in a mass ratio of 0.5~1.5:0.5~1.5:0.5~1. The extreme pressure anti-wear agent in the grease composition is used in an amount of 1-3 wt%. The mass ratio of the alkylnaphthalene synthetic oil to the ester synthetic oil is 1-3:1-3; The thickener is a composite calcium soap thickener, which is obtained by reacting fatty acids, small molecule acids and calcium hydroxide; wherein, the fatty acids include one or more of palmitic acid, myristic acid and lauric acid, the small molecule acid is boric acid, and the mass ratio of fatty acids to small molecule acids is 3 to 6:

1. The antioxidant is dodecyl selenide; The rust inhibitor is dodecenyl succinic acid.

2. The lubricating grease composition according to claim 1, characterized in that, The components include the following parts by weight: 72-90 parts base oil; Thickener 7-15 parts; 1-3 parts of extreme pressure anti-wear agent; Antioxidant 0.5 to 2 parts; Rust inhibitor 0.5 to 1.5 parts.

3. A method for preparing the lubricating grease composition according to claim 1 or 2, characterized in that, Includes the following steps: 50–70 wt% of the base oil is mixed with fatty acids and small molecule acids, and heated to 85–90°C to obtain a fatty acid solution. After heating to 95–100°C, 30–50 wt% of calcium hydroxide solution is added to initiate a saponification reaction. The temperature is then raised to 130–140°C and maintained. After drainage, the temperature is further raised to the highest refining temperature of 210–220°C and maintained. The remaining base oil is added to cool down the mixture. After cooling to below 80°C, additives are added for homogenization treatment, followed by degassing to obtain a lubricating grease composition.

4. The application of the grease composition according to claim 1 or 2 or the grease composition prepared by the preparation method according to claim 3 in wind power equipment.

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