Hydraulic oil composition

Abstract

The invention discloses a hydraulic oil composition. The hydraulic oil composition is prepared from the following raw materials in percentage by mass: 0.5 to 1.0 percent of an antioxidant, 0.2 to 0.5 percent of ionic liquid, 0.05 to 0.10 percent of a clearing agent, 0.05 to 0.10 percent of a dispersing agent, 0.03 to 0.05 percent of an anti-rust agent, 0.01 to 0.02 percent of a light stabilizer, 0.01 to 0.02 percent of an anti-foaming agent and the balance of base oil. The hydraulic oil composition can be used as anti-wear hydraulic oil of a high-pressure plunger pump, and has excellent wear resistance, oxidation resistance, filterability and the like. In addition, the hydraulic oil composition also passes a Xiaoson HPV35 + 35 high-pressure plunger pump bench test, and can be suitable for harsh high-pressure equipment hydraulic systems such as large excavators and the like.

Description

Technical Field

[0001] The invention relates to a hydraulic oil composition. Background Art

[0002] Excavators are called the "barometer" of construction machinery. Their hydraulic systems pay more attention to the service life and anti-wear performance of hydraulic oil. As an important part of the hydraulic system of excavators, the performance and specifications of hydraulic oil are constantly improving with the upgrade of excavator hydraulic equipment, and its working pressure is as high as 40MP or more. The size of the hydraulic oil tank is also gradually designed to be miniaturized. The reduction of the tank size and the increase of the working pressure make the hydraulic oil circulate at high pressure and high speed in a more compact space, and the working temperature is maintained at 80-100℃ or even higher, and the requirements for the actuator speed, system pressure and mechanism movement accuracy are also higher. High temperature is the main factor causing the oxidation and degradation of hydraulic oil. As the oil temperature increases, the oil is required to have better thermal oxidation stability; the oil should also have good defoaming and hydrolysis stability. Electro-hydraulic servo valves and proportional electromagnetic alarms are introduced into the hydraulic system. These components are highly sensitive, complex in structure, small in matching clearance, and highly sensitive, so the hydraulic oil is required to have high cleanliness and good filterability; high load is the main factor causing wear of hydraulic pumps and other components, and the oil should have good load-bearing and anti-wear properties during the lubrication process. Major foreign excavator manufacturers have launched special hydraulic oils to match their products to meet the performance requirements of the equipment. At present, the recommended oil change cycle of hydraulic oil used in most domestic excavators is less than 3000h, which lags behind the special oils of foreign excavator manufacturers.

[0003] Due to the differences in hydraulic pumps, application equipment and working environments, there are many types of hydraulic oils, and the performance requirements for hydraulic oils have different emphases. CN103087807 provides a high-purity hydraulic oil composition, which not only has the performance of traditional hydraulic oils, but also keeps the hydraulic oil system clean. CN114507554 provides a hydraulic oil composition with excellent low-temperature performance, shear stability, thermal stability and comprehensive performance, and has high biodegradability and low biotoxicity, which can meet the use conditions of hydraulic equipment in environmentally sensitive areas. CN112940829 provides a hydraulic oil composition with a high viscosity index, good anti-wear performance and oxidation stability, which can extend the service life of hydraulic oil and hydraulic components and improve the working efficiency of hydraulic machinery. CN 112592755 provides a high-efficiency ashless hydraulic oil composite composition, which can be used to prepare ashless anti-wear hydraulic oil, and has good anti-wear and anti-oxidation properties. However, at present, general-purpose HM anti-wear hydraulic oil has been used in high-pressure plunger pumps for a long time. In the middle and late stages of its life, it often has problems such as excessive sludge, slow action of the hydraulic system, valve sticking, filter clogging, and poor oil filterability after contact with water. In addition, there is no patent introduction of anti-wear hydraulic oil compositions developed for the performance characteristics of high-end equipment such as large excavators in domestic patents. Summary of the invention

[0004] In order to at least partially solve the above-mentioned technical problems existing in the prior art, an embodiment of the present invention provides a hydraulic oil composition with excellent comprehensive performance, which is suitable for the hydraulic system of harsh high-pressure equipment such as large excavators.

[0005] As one aspect of the present invention, it relates to a hydraulic oil composition, which comprises the following constituent raw materials by mass percentage: 0.5-1.0% antioxidant, 0.2-0.5% ionic liquid, 0.05-0.10% detergent, 0.05-0.10% dispersant, 0.03-0.05% rust inhibitor, 0.01-0.02% light stabilizer and 0.01-0.02% antifoaming agent, and the balance is base oil;

[0006] Wherein, the ionic liquid is as shown in formula (I):

[0007]

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

[0009] By adopting the above technical scheme, the ionic liquid of the present invention is further preferably a diimidazole cation and a diphosphate anion. The use of the ionic liquid to prepare a lubricating oil additive can improve the passivation metal activity and rust prevention performance of the lubricating oil additive, and improve the protection ability of the lubricating oil to metals; it has excellent solubility, and the C12-18 alkyl chain increases the solubility, has excellent compatibility, and ensures that it is dissolved in oil products under high and low temperature performance.

[0010] In one or some possible embodiments, the antioxidant includes: a phenolic antioxidant, an auxiliary antioxidant and zinc dialkyl dithiophosphate;

[0011] The mass ratio of the phenolic antioxidant to the auxiliary antioxidant is 5:1.

[0012] By adopting the above technical scheme, an antioxidant compounded with a phenolic antioxidant and an auxiliary antioxidant is used, which not only has excellent antioxidant properties, but can also effectively complex metal ions and has a metal passivation effect, thereby greatly reducing the generation of sludge. In addition, the volatility of the antioxidant is low, which can further reduce the volatilization of the antioxidant at high temperatures.

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

[0014]

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

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

[0017]

[0018] By adopting the above technical scheme, pentaerythritol bis(diphosphite) and pentaerythritol tetra(3-laurylthiopropionate) are selected as auxiliary antioxidants. Compared with traditional thioester antioxidants, their comprehensive performance is better. When used in combination with hindered phenol main antioxidants and dialkyl zinc dithiophosphate, the thermal stability of hydraulic oil can be significantly improved.

[0019] In one or some possible embodiments, the mass ratio of the pentaerythritol bis(diphosphite) to the pentaerythritol tetrakis(3-laurylthiopropionate) is 1:1.

[0020] In one or some possible embodiments, the detergent may be any commercially available material. The preferred detergent in the present invention is calcium salicylate T109B having a base value of 280 to 300.

[0021] By adopting the above technical scheme, the preferred detergent of the present invention can better dissolve and disperse the sludge, and at the same time reduce the particle size of the coated sludge, so that the sludge is reasonably distributed, the large particles are removed after passing through the filter, and the small particles are suspended in the oil and will not be deposited on the valve, and the final oil product has good permeability; in addition, calcium salicylate T109B with a base value of 280 to 300 has excellent detergency, high temperature stability, strong neutralization ability, and has excellent compounding performance with the calcium salt of aromatic sulfonic acid.

[0022] In one or some possible embodiments, the dispersant may be any commercially available material. To further enhance the effect of hydraulic oil in dispersing sludge, polyisobutylene succinimide is preferred in the present invention.

[0023] In one or some possible embodiments, the rust inhibitor may be any commercially available material, and the present invention preferably uses a calcium salt of an aromatic sulfonic acid.

[0024] By adopting the above technical solution, the preferred rust inhibitor of the present invention can form an adsorptive protective film on the metal surface, thereby inhibiting the contact between water and oxygen and preventing the metal from rusting.

[0025] In one or some possible embodiments, the anti-foaming agent is methyl silicone oil ester T903.

[0026] By adopting the above technical scheme, the preferred anti-foaming agent of the present invention overcomes the shortcomings of low solubility, poor air release and poor stability of silicone oil, and has excellent foam inhibition and solubility.

[0027] In one or some possible embodiments, the light stabilizer can be any commercially available material, and dimethyl sebacate is preferred in the present invention.

[0028] By adopting the above technical solution, the preferred light stabilizer of the present invention has good compatibility with lubricating oil, effectively improves thermal stability and weather resistance, and reduces the discoloration tendency of hydraulic oil.

[0029] In one or some possible embodiments, the base oil may be any commercially available material, and the base oil of the present invention is preferably a mixture of PCL150N and PCL500N.

[0030] The beneficial effects of the above technical solution provided by the embodiment of the present application include at least:

[0031] The hydraulic oil composition of the present invention can be used as an anti-wear hydraulic oil for a high-pressure plunger pump, has excellent anti-wear, anti-oxidation, filterability and other properties, has passed the Komatsu HPV35+35 high-pressure plunger pump bench test, and can be applied to the harsh high-pressure equipment hydraulic systems of large excavators and other equipment.

[0032] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0034] Figure 1 This is an appearance diagram of a hydraulic pump after the hydraulic oil composition of Example 1 of the present invention is subjected to HPV35+35 bench testing;

[0035] Figure 2 This is a diagram of the appearance of the plunger of the hydraulic oil composition of Example 1 of the present invention after being subjected to the HPV35+35 bench test. DETAILED DESCRIPTION

[0036] The exemplary embodiments of the present disclosure will be described in more detail below in conjunction with the accompanying drawings. The following are exemplary embodiments of the present disclosure, but it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art.

[0037] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0038] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0039] In the description of the present invention, it should be noted that the terms "include", "including", "have", "contain" and the like are open terms, meaning including but not limited to.

[0040] The present invention is further described below in conjunction with specific examples, and the protection scope of the present invention is not limited by the following examples. The sources of materials mainly involved in the examples are all conventional commercial products.

[0041] Example 1

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

[0043] Table 1 Constituent materials and mass percentages of hydraulic oil composition of Example 1

[0044]

[0045] Example 2

[0046] The components and mass percentages of the hydraulic oil composition of this embodiment are shown in Table 2 below:

[0047] Table 2 Constituent materials and mass percentages of hydraulic oil composition of Example 2

[0048]

[0049]

[0050] Example 3

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

[0052] Table 3 Constituent materials and mass percentages of hydraulic oil composition of Example 3

[0053]

[0054]

[0055] The inventors took the above embodiment as an example to conduct key performance tests such as thermal stability, filterability and oxidation stability and Komatsu HPV35+35 bench test, and the results are shown in Table 4 below:

[0056] Table 4 Performance test data

[0057]

[0058]

[0059] The performance test data results in Table 4 show that the hydraulic oil composition prepared by the present invention has excellent anti-wear, anti-oxidation, storage stability, anti-foaming, friction characteristics, etc. The total sediment weight of thermal stability is less than 10 mg, and the anti-wear performance is tested by the Komatsu HPV35+35 bench. Figure 1 and Figure 2 It can be seen that the hydraulic oil composition prepared in Example 1 has a smooth and flat appearance after the HPV35+35 bench test, without obvious wear, which further illustrates that the hydraulic oil composition prepared in the present invention has excellent wear resistance.

[0060] In addition, it can be seen from the performance test data results in Table 4 that the static friction coefficient of the hydraulic oil composition of the present invention meets the requirements, and it has excellent filterability, anti-foaming agent, etc., and the key performance meets the stringent requirements of the high-pressure plunger pump hydraulic system.

[0061] Although the description of the present invention has been quite detailed and has been described in particular with respect to several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, so as to effectively cover the intended scope of the present invention. In addition, the present invention is described above with the embodiments foreseeable by the inventors, and its purpose is to provide a useful description, and those non-substantial changes to the present invention that are not currently foreseen may still represent equivalent changes of the present invention.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0063] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A hydraulic oil composition, characterized in that: The composition comprises the following raw materials by mass percentage: 0.5-1.0% antioxidant, 0.2-0.5% ionic liquid, 0.05-0.10% detergent, 0.05-0.10% dispersant, 0.03-0.05% rust inhibitor, 0.01-0.02% light stabilizer and 0.01-0.02% antifoaming agent, and the balance is base oil; Wherein, the ionic liquid is as shown in formula (I): In formula (I), the value range of n is 12≤n≤18, and n is an integer.

2. The hydraulic oil composition according to claim 1, characterized in that: The antioxidants include: phenolic antioxidants, auxiliary antioxidants and zinc dialkyl dithiophosphates; The mass ratio of the phenolic antioxidant to the auxiliary antioxidant is 5:

1.

3. The hydraulic oil composition according to claim 2, characterized in that: The phenolic antioxidant is shown in formula (II): In formula (II), the value range of n is 12≤n≤18, and n is an integer; The auxiliary antioxidant is a mixture of pentaerythritol bis diphosphite and pentaerythritol tetrakis (3-laurylthiopropionate) in any ratio, and the pentaerythritol bis diphosphite is as shown in formula (III):

4. The hydraulic oil composition according to claim 3, characterized in that: The mass ratio of the pentaerythritol bis(diphosphite) to the pentaerythritol tetrakis(3-laurylthiopropionate) is 1:

1.

5. The hydraulic oil composition according to claim 1, characterized in that: The detergent is selected from calcium salicylate T109B with a base value of 280-300.

6. The hydraulic oil composition according to claim 1, characterized in that: The dispersant is polyisobutylene succinimide.

7. The hydraulic oil composition according to claim 1, characterized in that: The rust inhibitor is a calcium salt of an aromatic sulfonic acid.

8. The hydraulic oil composition according to claim 1, characterized in that: The anti-foaming agent is methyl silicone oil ester T903.

9. The hydraulic oil composition according to claim 1, characterized in that: The light stabilizer is dimethyl sebacate.

10. The hydraulic oil composition according to claim 1, characterized in that: The base oil is a mixture of PCL150N and PCL500N.

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