A hydraulic oil composition

Abstract

The application discloses a hydraulic oil composition. The hydraulic oil composition comprises the following components in percentage by mass: 20-40% of an anti-wear agent, 20-40% of an antioxidant, 10-20% of an ionic liquid, 5-10% of a detergent, 5-10% of a dispersant, 3-5% of an extreme pressure agent, 3-5% of an anti-rust agent and 2-5% of a light stabilizer, and the balance is dilution oil. The hydraulic oil composition has excellent wear resistance, oxidation resistance, low sludge resistance and other performances, and passes the Bosch Rexroth RFT APU CL super-high pressure plunger pump, and can be applied to the hydraulic systems of super-high pressure equipment such as giant die forging hydraulic machines, shield machines and deep sea oil and gas development equipment.

Description

Technical Field

[0001] This invention relates to a hydraulic oil composition. Background Technology

[0002] As the most widely used industrial lubricant, hydraulic oils come in many varieties, each with different performance requirements. CN115992025 provides a hydraulic oil composition with excellent oxidation resistance. This composition, formulated with ester-based base oils and anti-wear agents, rust inhibitors, metal deactivators, antioxidants, and viscosity index improvers, meets the specifications for L-HV and L-HS hydraulic oils in GB11118.1-2011, and is particularly suitable for hydraulic equipment operating at high temperatures for extended periods. CN115637186 ​​provides a high-temperature and anti-wear hydraulic oil with excellent high-temperature and anti-wear properties, extending the service life of the hydraulic oil and preventing deterioration. CN103087807 provides a high-cleanliness hydraulic oil composition that, in addition to the performance of traditional hydraulic oils, maintains the cleanliness of the hydraulic oil system. CN 116240064 discloses a hydraulic oil with high annealing detergency, its preparation method, and its application. This oil is characterized by being ashless, stain-free after annealing, and possessing excellent extreme pressure and anti-wear properties, making it suitable for hydraulic systems in rolling mills. However, hydraulic oils suitable for ultra-high pressure systems are rarely reported.

[0003] With the development of hydraulic technology, ultra-high pressure has demonstrated significant performance advantages in many heavy-duty equipment. Increased system pressure greatly simplifies the main structure, significantly reduces weight, improves output per unit weight, reduces energy consumption in manufacturing, and decreases industrial pollution emissions. With the increasing demand for critical industrial equipment such as giant forging hydraulic presses, tunnel boring machines, and deep-sea oil and gas development equipment, hydraulic technology is shifting towards ultra-high pressure and high flow rates. The RDE90245 certification, developed by Bosch Rexroth, a world-renowned hydraulic pump manufacturer, is a high-pressure hydraulic oil certification system. It uses the stringent RFT-APU-CL hydraulic pump test bench, which has a maximum pressure of 50 MPa, a speed of 4000 rpm, and a circulating oil temperature exceeding 80°C. It is currently the world's highest-pressure and most demanding hydraulic oil test bench, used to comprehensively evaluate the wear resistance and oxidation life of hydraulic oils. However, few domestic hydraulic oil technologies can pass this ultra-high pressure test bench, and commercially available hydraulic oils are unlikely to provide effective protection for the hydraulic pump and motor. Furthermore, no relevant existing technologies have been reported. Summary of the Invention

[0004] In order to at least partially solve the above-mentioned technical problems existing in the prior art, the present invention provides a hydraulic oil composition with excellent comprehensive performance and capable of passing the Bosch Rexroth RFT APU CL ultra-high pressure plunger pump bench test, so as to be suitable for the hydraulic system of ultra-high pressure equipment.

[0005] As one aspect of the present invention, a hydraulic oil composition is provided, the hydraulic oil composition comprising, by weight percentage: 20-40% anti-wear agent, 20-40% antioxidant, 10-20% ionic liquid, 5-10% detergent, 5-10% dispersant, 3-5% extreme pressure agent, 3-5% rust inhibitor, and 2-5% light stabilizer, with the balance being diluent oil;

[0006] The ionic liquid is as shown in formula (Ⅰ):

[0007]

[0008] In equation (Ⅰ), the value of n is in the range of 12≤n≤18, where n is an integer.

[0009] By adopting the above technical solution, the ionic liquid of the present invention is further preferably a diimidazole cation and a diphosphate anion. Using the ionic liquid to prepare lubricating oil additives can improve the metal passivation activity and rust prevention performance of the lubricating oil additives, and improve the protective ability of lubricating oil to metals. It has excellent solubility, and the C12-18 alkyl chain increases the solubility. It has excellent compatibility and ensures that it dissolves in oil under high and low temperature conditions.

[0010] In one or more possible embodiments, the antioxidant includes phenolic antioxidants and auxiliary antioxidants.

[0011] By adopting the above technical solution, an antioxidant compounded with phenolic antioxidants and auxiliary antioxidants not only has excellent antioxidant performance, but can also effectively complex metal ions and has a metal passivation effect, thereby greatly reducing the generation of sludge. In addition, the antioxidant has low volatility, which can further reduce the volatilization of antioxidants at high temperatures.

[0012] In one or more possible embodiments, the mass ratio of the phenolic antioxidant to the auxiliary antioxidant is (2-3):1.

[0013] In one or more possible embodiments, the phenolic antioxidant is as shown in formula (II):

[0014]

[0015] In equation (II), the value of n is in the range of 12≤n≤18, where n is an integer;

[0016] The auxiliary antioxidant is a mixture of pentaerythritol bis(diphosphite) and pentaerythritol tetra(3-lauryl thiopropionate) in any ratio, wherein the pentaerythritol bis(diphosphite) is as shown in formula (III):

[0017]

[0018] By adopting the above technical solution, pentaerythritol bis(diphosphite) and pentaerythritol tetra(3-lauryl thiopropionate) are selected as auxiliary antioxidants. Compared with traditional thioester antioxidants, their comprehensive performance is superior. When used in combination with hindered phenolic main antioxidants and detergents, the thermal stability of hydraulic oil can be significantly improved.

[0019] In one or more possible embodiments, the mass ratio of the pentaerythritol bis(diphosphite) to the pentaerythritol tetra(3-lauryl thiopropionate) is 1:1.

[0020] In one or more possible embodiments, the anti-wear agent can be any commercially available material, with triphenyl thiophosphate T309 being preferred in this invention.

[0021] In one or more possible embodiments, the detergent can be any commercially available material, and the present invention preferably uses calcium salicylate T109B with an alkalinity of 280-300.

[0022] By adopting the above technical solution, the detergent of the present invention can better dissolve and disperse oil sludge, while reducing the particle size of the coated oil sludge, so that the oil sludge is reasonably distributed. Large particles are discharged after passing through the filter, while small particles of oil sludge are suspended in the oil and will not be deposited on the valve, resulting in good permeability of the final oil product. In addition, calcium salicylate T109B with an alkalinity of 280-300 has excellent detergent properties, high temperature stability, strong neutralization ability, and excellent compounding performance with calcium salts of aromatic sulfonic acids.

[0023] In one or more possible embodiments, the dispersant can be any commercially available material. To further enhance the dispersing effect of hydraulic oil on sludge, the present invention preferably uses polyisobutylene succinimide, as shown in formula (Ⅳ):

[0024]

[0025] In one or more possible embodiments, the extreme pressure agent can be any commercially available material, with sulfurized olefin cottonseed oil T405 being preferred in this invention.

[0026] By adopting the above technical solution, the preferred extreme pressure agent of the present invention can form a solid oil film on the metal surface, thereby enabling the hydraulic oil product to have extreme pressure anti-wear properties and a low coefficient of friction.

[0027] In one or more possible embodiments, the rust inhibitor can be any commercially available material, but the present invention preferably uses a calcium salt of an aromatic sulfonic acid.

[0028] By adopting the above technical solution, the preferred rust inhibitor of the present invention can form an adsorbent protective film on the metal surface, thereby inhibiting the contact between water and oxygen and preventing the metal from rusting.

[0029] In one or more possible embodiments, the light stabilizer can be any commercially available material, with dimethyl sebacate being preferred in this invention.

[0030] By adopting the above technical solution, the light stabilizer preferred by the present invention effectively improves thermal stability and weather resistance, and reduces the discoloration trend of hydraulic oil.

[0031] In one or more possible embodiments, the diluent oil can be any commercially available material, with PCL150SN being preferred in this invention.

[0032] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of this application include at least the following:

[0033] The hydraulic oil composition of the present invention is suitable for anti-wear hydraulic oil of ultra-high pressure plunger pumps, and has excellent anti-wear, anti-oxidation, and low sludge properties.

[0034] The hydraulic oil composition of the present invention is compatible with the Bosch Rexroth RFT APU CL ultra-high pressure piston pump and is suitable for the hydraulic systems of ultra-high pressure equipment such as giant die forging hydraulic presses, tunnel boring machines, and deep-sea oil and gas development equipment.

[0035] 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. Detailed Implementation

[0036] Exemplary embodiments of this disclosure will now be described in more detail. These are exemplary embodiments of the disclosure; however, it should be understood that the 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 the disclosure to those skilled in the art.

[0037] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0038] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0039] In the description of this invention, it should be noted that the terms "comprising", "including", "having", "containing", etc., are all open-ended terms, meaning that they include but are not limited to.

[0040] The present invention will be further described below with reference to specific embodiments. The scope of protection of the present invention is not limited by the following embodiments. The main materials involved in the embodiments are all conventional commercially available products.

[0041] Example 1

[0042] The constituent raw materials and their mass percentages of the hydraulic oil composition in this embodiment are shown in Table 1 below:

[0043] Table 1. Composition of the hydraulic oil composition in Example 1 and its mass percentage.

[0044]

[0045]

[0046] Example 2

[0047] The constituent raw materials and their mass percentages of the hydraulic oil composition in this embodiment are shown in Table 2 below:

[0048] Table 2. Composition of the hydraulic oil composition in Example 2 and its mass percentage.

[0049]

[0050] Example 3

[0051] The constituent raw materials and their mass percentages of the hydraulic oil composition in this embodiment are shown in Table 3 below:

[0052] Table 3. Composition of the hydraulic oil composition in Example 3 and its mass percentage.

[0053]

[0054] Taking Examples 1, 2, and 3 as examples, the inventors conducted key performance tests such as oxidation resistance and thermal stability after blending the products with Group II hydrotreated base oils PCL150N and 500N. The results are shown in Table 4 below:

[0055] Table 4 Key Performance Test Data

[0056]

[0057]

[0058] The key performance test data in Table 4 show that the hydraulic oil composition prepared by this invention has excellent anti-wear properties, oxidation resistance, storage stability, hydrolytic stability, and anti-foaming properties. The total sediment weight for thermal stability is less than 10 mg, and the anti-wear performance passes the Bosch Rexroth RFT APU CL ultra-high pressure plunger pump bench test.

[0059] Taking the hydraulic oil composition prepared in Example 1 as an example, the test data of it using a Bosch Rexroth RFT APU CL ultra-high pressure plunger pump bench is recorded in Table 5 below.

[0060] Table 5. Wear of the RFT APU CL ultra-high pressure plunger pump test bench.

[0061]

[0062]

[0063] As can be seen from the wear data in Table 5, the wear of the nine plungers on this test bench is extremely low. Therefore, it can be concluded that the hydraulic oil composition of this invention is suitable for the hydraulic systems of ultra-high pressure equipment such as giant forging hydraulic presses, tunnel boring machines, and deep-sea oil and gas development equipment.

[0064] Although the invention has been described in considerable detail and particularly with regard to several of the described embodiments, it is not intended to limit itself to any of these details or embodiments or any particular embodiment, thereby effectively covering the intended scope of the invention. Furthermore, the invention has been described above with respect to embodiments foreseeable by the inventors in order to provide a useful description, and non-substantial modifications to the invention that have not yet been foreseen may still represent equivalent modifications.

[0065] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0066] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A hydraulic oil composition characterized by, By mass percentage, the following raw materials are included: anti-wear agent 20~40%, antioxidant 20~40%, ionic liquid 10~20%, detergent 5~10%, dispersant 5~10%, extreme pressure agent 3~5%, anti-rust agent 3~5% and light stabilizer 2~5%, and the balance is diluent oil; The ionic liquid is shown as formula (I): （Ⅰ）， In formula (I), the value range of n is 12≤n≤18, and n is an integer; The antioxidant is a phenolic antioxidant and an auxiliary antioxidant; The phenolic antioxidant is shown as formula (II): （Ⅱ）， In formula (II), the value range of n is 12≤n≤18, and n is an integer; The auxiliary antioxidant is an arbitrary ratio mixture of pentaerythritol bis-diphosphite and pentaerythritol tetra (3-laurylthiopropionate), the pentaerythritol bis-diphosphite is shown as formula (III): （Ⅲ）； The mass ratio of the phenolic antioxidant to the auxiliary antioxidant is (2~3):1; The detergent is calcium salicylate T109B with a base value of 280~300; the dispersant is polyisobutylene succinimide; the anti-rust agent is a calcium salt of aromatic sulfonic acid; the light stabilizer is dimethyl sebacate; and the diluent oil is PCL150SN.

2. The hydraulic oil composition according to claim 1, characterized by The mass ratio of the pentaerythritol bis-diphosphite to the pentaerythritol tetra (3-laurylthiopropionate) is 1:

1.

3. The hydraulic oil composition according to claim 1, characterized by The anti-wear agent is triphenyl phosphorothionite T309.

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