Ashless antioxidant composition suitable for ultrahigh-temperature lubricating environment, lubricating oil and application thereof

Abstract

The invention discloses an ashless antioxidant composition applicable to an ultrahigh-temperature lubricating environment, lubricating oil and application of the ashless antioxidant composition. The ashless antioxidant composition is prepared from the following components in parts by mass: 2.5 to 5 parts of dialkyl diphenylamine, 2.5 to 7.5 parts of N-phenyl-alpha-naphthylamine, 0 to 2.5 parts of phenolic antioxidant and 0 to 2.5 parts of amine antioxidant. The ashless antioxidant composition does not contain metal elements, is an ashless antioxidant system, has a good antioxidant effect, can effectively control the viscosity change and acid value increase of an oil product in an ultrahigh-temperature environment of 220-300 DEG C, has an obvious inhibition effect on the generation of high-temperature sediments, and can meet the requirement of an aero-engine on the antioxidant performance of lubricating oil in the ultrahigh-temperature environment.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil technology, and in particular to an ashless antioxidant composition suitable for ultra-high temperature lubrication environments, a lubricating oil, and its applications. Background Technology

[0002] Lubricating oil, as the "blood" of equipment, plays a vital role in reducing friction and wear, saving energy, and extending the life of machinery. It is a crucial factor affecting the reliability, stability, and service life of equipment. In recent years, with the rapid development of high-end equipment in industries such as aviation, automotive, rail transportation, and construction, mechanical equipment is evolving towards miniaturization, high power, high efficiency, and high reliability. This places higher demands on the performance of lubricating materials under harsh conditions such as high / ultra-high temperature, low viscosity, heavy load, and high speed and high pressure.

[0003] High-end equipment industries such as aviation, wind power, rail transportation, and large-scale machinery are experiencing rapid development, with harsh environments such as high / ultra-high temperatures, high speeds, high pressures, heavy loads, and corrosion becoming the norm. For example, aero engines, which provide the power needed for aircraft flight, are the "heart" of aircraft and the direct source of their power, often hailed as the "crown jewel" of modern industry. Their development level is a significant indicator of a nation's technological and industrial strength. Currently, the engines used in civil commercial aircraft, i.e., large aircraft, are turbofan engines. As the range of large civil aircraft increases, the thrust-to-weight ratio of turbofan engines is continuously improving. Fourth-generation turbofan engines have a thrust-to-weight ratio of over 10, fifth-generation turbofan engines have increased to 12-13, and the sixth-generation turbofan engines under development are expected to reach a thrust-to-weight ratio of over 15. With the continuous increase in the thrust-to-weight ratio of turbofan engines, the turbine inlet temperature is also continuously increasing. The turbine inlet temperature of fifth-generation turbofan engines has already reached 1700℃, and it is expected that the turbine inlet temperature of sixth-generation turbofan engines will reach 2000℃. The increase in turbine inlet temperature directly affects the temperature of the nearby main bearing, which in turn increases the temperature of the engine lubrication system. The operating temperature of the turbofan engine lubrication system will rise to over 260°C. Existing lubricating oils cannot meet the requirements of aero-engines for anti-oxidation performance in ultra-high temperature (220-300°C) environments. Summary of the Invention

[0004] To meet the requirements of aero-engines for anti-oxidation performance of lubricating oil in ultra-high temperature environments (220-300°C), improve the anti-oxidation performance of antioxidant compositions, enrich technical routes, and increase the selection space, this invention provides an ashless antioxidant composition, a lubricating oil, and their applications suitable for ultra-high temperature lubrication environments.

[0005] In a first aspect, embodiments of the present invention provide an ashless antioxidant composition suitable for ultra-high temperature lubrication environments. The composition may include, by mass parts: 2.5 to 5 parts of dialkyldiphenylamine, 2.5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, and 0 to 2.5 parts of amine antioxidant.

[0006] In a preferred embodiment, the above-mentioned ashless antioxidant composition, by weight parts, comprises: 2.5 to 5 parts of dialkyldiphenylamine, 5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, and 0 to 2.5 parts of amine antioxidant.

[0007] In one embodiment, the structural formula of the dialkyldiphenylamine is:

[0008]

[0009] R1 and R2 are H or alkyl groups with C1-C12 carbon atoms.

[0010] In a preferred embodiment, R1 and R2 are alkyl groups having C4, C8, or C10 carbon atoms.

[0011] In one embodiment, the chemical formula of the N-phenyl-α-naphthylamine is: Ar 1 -NH-Ar 2 ;

[0012] Among them, Ar 1 Ar 2 They are selected from H, phenyl, naphthyl, and phenyl or naphthyl with C1-C12 alkyl groups, respectively.

[0013] In another embodiment, Ar 1 Ar 2 The selected phenyl groups are all connected to alkyl chains, and the alkyl chains are located at the ortho, meta, or para positions of the amino group.

[0014] In a second aspect, embodiments of the present invention provide a lubricating oil comprising a pentaerythritol ester base oil and an ashless antioxidant composition suitable for ultra-high temperature lubrication environments as described in the first aspect.

[0015] The ashless antioxidant composition comprises 5 to 15 parts by weight, and the pentaerythritol ester base oil comprises 85 to 95 parts by weight.

[0016] In one embodiment, the lubricating oil, by weight, comprises: 2.5 to 5 parts of dialkyldiphenylamine, 2.5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, 0 to 2.5 parts of amine antioxidant, and 85 to 95 parts of pentaerythritol ester base oil.

[0017] In a preferred embodiment, the lubricating oil, by weight, comprises: 2.5 to 5 parts of dialkyl diphenylamine, 5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, 0 to 2.5 parts of amine antioxidant, and 85 to 90 parts of pentaerythritol ester base oil.

[0018] Thirdly, embodiments of the present invention provide an application of the ashless antioxidant composition suitable for ultra-high temperature lubrication environments as described in the first aspect in an engine lubrication system.

[0019] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0020] This invention provides an ashless antioxidant composition, a lubricating oil, and their applications suitable for ultra-high temperature lubrication environments. The ashless antioxidant composition does not contain any metal elements and is an ashless antioxidant system with good antioxidant effect. In ultra-high temperature environments of 220℃ to 300℃, it can effectively control the change in oil viscosity and the increase in acid value, and has a significant inhibitory effect on the formation of high-temperature deposits. It can meet the requirements of aero-engines for the antioxidant performance of lubricating oil in ultra-high temperature environments (220~300℃).

[0021] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description.

[0022] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0023] Exemplary embodiments of this disclosure will now be described in more detail. While exemplary embodiments of this disclosure have been shown, it should be understood that this disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0024] The ashless antioxidant composition suitable for ultra-high temperature lubrication environments provided in this embodiment of the invention comprises, by weight parts: 2.5 to 5 parts of dialkyldiphenylamine, 2.5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, and 0 to 2.5 parts of amine antioxidant.

[0025] Preferably, the composition comprises, by weight parts: 2.5 to 5 parts of dialkyldiphenylamine, 5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, and 0 to 2.5 parts of amine antioxidant.

[0026] This invention, through studies on the antioxidant properties and compatibility of antioxidant additives with different structures under different temperature conditions, investigates the compounding rules of various types of antioxidant components in ashless antioxidant compositions. By employing novel high-molecular-weight polymeric phenolic antioxidants and high-molecular-weight polymeric amine antioxidants, it breaks away from traditional small-molecule antioxidant systems, endowing the invention with excellent antioxidant properties, which can meet the antioxidant performance requirements of lubricating oils in ultra-high temperature environments (220–300℃).

[0027] The structural formula of the dialkyldiphenylamine in the embodiments of the present invention is as follows:

[0028]

[0029] Wherein, R1 and R2 are H or alkyl groups having C1-C12 carbon atoms, and more preferably, R1 and R2 are alkyl groups having C4, C8 or C10 carbon atoms.

[0030] The chemical formula of the above-mentioned N-phenyl-α-naphthylamine in the embodiments of the present invention is: Ar 1 -NH-Ar 2 ;

[0031] Among them, Ar 1 Ar 2 They are selected from H, phenyl, naphthyl, and phenyl or naphthyl groups attached to C1-C12 alkyl groups. Preferably, Ar... 1 Ar 2 The selected phenyl groups are all connected to alkyl chains, and the alkyl chains are located at the ortho, meta, or para positions of the amino group.

[0032] This invention also provides a lubricating oil comprising pentaerythritol ester base oil and the above-mentioned ashless antioxidant composition suitable for ultra-high temperature lubrication environments; by weight, the ashless antioxidant composition comprises 5 to 15 parts and the pentaerythritol ester base oil comprises 85 to 95 parts.

[0033] Further, the lubricating oil, by weight parts, comprises: 2.5 to 5 parts of dialkyldiphenylamine, 2.5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, 0 to 2.5 parts of amine antioxidant, and 85 to 95 parts of pentaerythritol ester base oil. Preferably, by weight parts, it comprises: 2.5 to 5 parts of dialkyldiphenylamine, 5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, 0 to 2.5 parts of amine antioxidant, and 85 to 90 parts of pentaerythritol ester base oil.

[0034] In this embodiment of the invention, the macromolecular phenolic antioxidant is from BASF. L101; the macromolecular amine antioxidant is from BASF. L150. The pentaerythritol ester base oil is BASE5750 from NYCO, France. Experimental methods in the following examples of this invention, unless otherwise specified, were performed according to conventional methods and conditions. All raw materials used in the following examples, unless otherwise specified, were commercially available.

[0035] Example 1

[0036] Taking the production of 100g of product 1 of this invention as an example, the raw materials and their quantities are as follows:

[0037]

[0038] Example 2:

[0039] Taking the production of 100g of product 2 of this invention as an example, the raw materials and their quantities are as follows:

[0040]

[0041] Example 3

[0042] Taking the production of 100g of product in Example 3 of this invention as an example, the raw materials and their quantities are as follows:

[0043]

[0044] Example 4

[0045] Taking the production of 100g of product in Example 4 of this invention as an example, the raw materials and their quantities are as follows:

[0046]

[0047] Example 5

[0048] Taking the production of 100g of product 5 of this invention as an example, the raw materials and their quantities are as follows:

[0049]

[0050] Example 6

[0051] Taking the production of 100g of product in Example 6 of this invention as an example, the raw materials and their quantities are as follows:

[0052]

[0053] To verify the effectiveness of the embodiments of the present invention, the inventors evaluated the antioxidant performance of the ashless antioxidant compositions suitable for ultra-high temperature lubrication environments prepared in this embodiment by blending them with the same aero-engine base component, 5 centistorelene ester. In the laboratory, the high-temperature oxidation stability of ashless antioxidants with different structures was evaluated using tests such as the aero-turbine engine oil corrosion and oxidation stability test (GJB499), the VPC vapor phase coking test (ARP5921), and the high-temperature bearing deposition performance test. The aero-turbine engine oil corrosion test was set at a temperature of 220℃~240℃ for 72 hours; the VPC vapor phase coking test was set at a temperature of 371℃ for 18 hours; and the high-temperature bearing deposition performance test was set at a temperature of 200℃~260℃ for 200 hours. The test results are as follows:

[0054] 1. Corrosion test of turbine engine oil of the ashless antioxidant composition of the present invention under different test temperatures.

[0055] Table 1. Test data on the corrosion resistance of turbine engine oil of the ashless antioxidant composition of the present invention (230℃, 72h)

[0056]

[0057] Table 2. Test data on the corrosion resistance of turbine engine oil of the ashless antioxidant composition of the present invention (240℃, 72h)

[0058]

[0059] Table 3. Test data on the corrosion resistance of turbine engine oil of the ashless antioxidant composition of the present invention (250℃, 72h)

[0060]

[0061] Analysis of Tables 1-3 above shows that the ashless antioxidant composition in Example 1 of this invention exhibits excellent viscosity growth control capability in turbine engine oil corrosion tests at different temperatures; and the viscosity growth control capability becomes more pronounced as the temperature increases. In particular, it retains a certain degree of fluidity even after stable operation at an ultra-high temperature of 250°C for 72 hours, while other commercially available aviation engine oils exhibit a solidified state, completely losing their lubricating properties.

[0062] 2. VPC vapor phase coking test of the ashless antioxidant compositions in Examples 1-6 of this invention

[0063] Table 4. VPC vapor phase coking test data of the ashless antioxidant composition of the present invention.

[0064]

[0065] In the VPC vapor phase coking test, the high-temperature antioxidant performance of Examples 1 to 6 showed significant differences. The overall antioxidant performance, from best to worst, was as follows: Example 6, Example 5, Example 4, Example 2 and Example 3 (both are comparable), Example 1. Detailed analysis is as follows:

[0066] Example 1 (dialkyldiphenylamine and N-phenyl-α-naphthylamine) in a certain ratio can effectively improve antioxidant properties, exhibit good viscosity control ability, and effectively control the increase of acid value. Example 2, compared with Example 1, does not change the compounding ratio but increases the overall amount added, which can further reduce the formation of sediment and reduce the acid value. Example 3, compared with Example 2, changes the compounding ratio and finds no significant change in sediment production, indicating that there is an optimal ratio for the compounding of dialkyldiphenylamine and N-phenyl-α-naphthylamine (an aromatic amine). Examples 4 and 5, based on Example 2, respectively added high molecular weight phenolic antioxidants and high molecular weight amine antioxidants. It can be seen that Example 4 does not significantly improve sediment formation compared with Example 2, but the viscosity change rate is significantly reduced, effectively controlling viscosity growth. Example 5, compared with Example 2, significantly reduces sediment formation, but the viscosity change rate is increased, indicating a decrease in viscosity control ability. Example 6, based on Example 2, simultaneously added high molecular weight phenolic antioxidants and high molecular weight amine antioxidants. It can be seen that not only can it effectively reduce the formation of sediments, but the viscosity change rate and acid value increase do not change significantly. This indicates that while ensuring a certain viscosity control capability and controlling acid value increase, sediment production can be significantly reduced.

[0067] 3. Bearing deposition performance test of the ashless antioxidant composition of Example 1 of the present invention

[0068] Table 5. Bearing deposition performance test of the ashless antioxidant composition in Example 1 of the present invention.

[0069]

[0070] The ashless antioxidant composition in Example 1 of this invention exhibited excellent deposit control ability, good viscosity growth control ability, and small acid value change in two bearing deposition performance tests.

[0071] The ashless antioxidant composition provided in this embodiment of the invention, in which dialkyldiphenylamine and N-phenyl-α-naphthylamine (an aromatic amine) are compounded in a certain proportion, can effectively improve the antioxidant performance, exhibit excellent viscosity control ability at different temperatures, and effectively control the increase of acid value. Through comparative analysis of the examples, it was found that the selection of antioxidants with different structures and the determination of the compounding ratio directly determine the antioxidant performance of the ashless antioxidant composition. The compounding of dialkyldiphenylamine and N-phenyl-α-naphthylamine (an aromatic amine) exhibits excellent deposit control ability; increasing the amount added at a fixed ratio can further reduce deposit formation. There is an optimal ratio for the compounding of dialkyldiphenylamine and N-phenyl-α-naphthylamine (an aromatic amine); changing the ratio will actually reduce the antioxidant capacity. Both high molecular weight phenolic antioxidants and high molecular weight amine antioxidants can effectively improve the viscosity control ability of lubricating oil at different temperatures, but high molecular weight amine antioxidants exhibit better acid value control ability than high molecular weight phenolic antioxidants.

[0072] The ashless antioxidant composition provided in this embodiment of the invention does not contain any metal elements and is an ashless antioxidant system with good antioxidant effect. It can effectively control the change of oil viscosity and the increase of acid value in ultra-high temperature environments of 220℃ to 300℃, and has a significant inhibitory effect on the formation of high temperature deposits. It can meet the requirements of aero-engines for the antioxidant performance of lubricating oil in ultra-high temperature environments (220~300℃).

[0073] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A ashless antioxidant composition suitable for ultra-high temperature lubrication environments, characterized in that, The composition comprises, by weight parts: 2.5 to 5 parts of dialkyldiphenylamine, 2.5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, and 0 to 2.5 parts of amine antioxidant.

2. The composition according to claim 1, characterized in that, The composition comprises, by weight parts: 2.5 to 5 parts of dialkyldiphenylamine, 5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, and 0 to 2.5 parts of amine antioxidant.

3. The composition according to claim 1 or 2, characterized in that, The structural formula of the dialkyldiphenylamine is: R1 and R2 are H or alkyl groups with C1-C12 carbon atoms.

4. The composition according to claim 3, characterized in that, R1 and R2 are alkyl groups with 4, 8, or 10 carbon atoms.

5. The composition according to claim 1 or 2, characterized in that, The chemical formula of the N-phenyl-α-naphthylamine is: Ar 1 -NH-Ar 2 ; Among them, Ar 1 Ar 2 They are selected from H, phenyl, naphthyl, and phenyl or naphthyl with C1-C12 alkyl groups, respectively.

6. The composition according to claim 5, characterized in that, Ar 1 Ar 2 The selected phenyl groups are all connected to alkyl chains, and the alkyl chains are located at the ortho, meta, or para positions of the amino group.

7. A lubricating oil, characterized in that, The lubricating oil includes pentaerythritol ester base oil and an ashless antioxidant composition suitable for ultra-high temperature lubrication environments as described in any one of claims 1 to 5. The ashless antioxidant composition comprises 5 to 15 parts by weight, and the pentaerythritol ester base oil comprises 85 to 95 parts by weight.

8. The lubricating oil according to claim 7, characterized in that, The lubricating oil comprises, by weight, 2.5 to 5 parts of dialkyl diphenylamine, 2.5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, 0 to 2.5 parts of amine antioxidant, and 85 to 95 parts of pentaerythritol ester base oil.

9. The lubricating oil according to claim 10, characterized in that, The lubricating oil comprises, by weight, 2.5 to 5 parts of dialkyl diphenylamine, 5 to 7.5 parts of N-phenyl-α-naphthylamine, 0 to 2.5 parts of phenolic antioxidant, 0 to 2.5 parts of amine antioxidant, and 85 to 90 parts of pentaerythritol ester base oil.

10. The application of an ashless antioxidant composition suitable for ultra-high temperature lubrication environments as described in any one of claims 1 to 6 in an engine lubrication system.

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