Ultralow-temperature zinc-free hydraulic oil for engineering machinery in severe cold area and preparation method of ultralow-temperature zinc-free hydraulic oil

Abstract

The invention discloses ultralow-temperature zinc-free hydraulic oil for engineering machinery in severe cold areas and a preparation method of the ultralow-temperature zinc-free hydraulic oil. The ultralow-temperature zinc-free hydraulic oil is prepared from the following raw materials in percentage by mass: 80 to 89 percent of base oil, 10 to 19 percent of a viscosity index improver, 0.3 to 1.0 percent of an anti-wear agent, 0.1 to 1.5 percent of an antioxidant, 0.01 to 0.15 percent of a calcium-based additive, 0.005 to 0.02 percent of a demulsifying agent and 0.005 to 0.02 percent of a de-foaming agent. The special ultralow-temperature zinc-free hydraulic oil for the engineering machinery in the severe cold area has excellent low-temperature fluidity and viscosity-temperature property, and the kinematic viscosity of the oil product is less than 1500mm < 2 > / s under the condition of-30 DEG C; under the condition of-40 DEG C, the kinematic viscosity is less than 4500 mm < 2 > / s, and the lubricating oil is suitable for oil requirements of movable hydraulic systems in some high-latitude regions (the lowest temperature in winter is close to-40 DEG C). The prepared ultralow-temperature zinc-free hydraulic oil special for the engineering machinery in the severe cold area has excellent high-temperature detergency. According to the zinc-free hydraulic oil, an oil product can still maintain the states of clear and transparent appearance, stable acid value at a lower level and extremely low oil sludge content under the working conditions of higher temperature and long-period operation.

Description

Technical Field

[0001] The invention relates to an ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions and a preparation method thereof. Background Art

[0002] Cold and extremely cold regions at home and abroad cover a large area, and in some areas the temperature can even reach dozens of degrees below zero in winter. Conventional ultra-low temperature hydraulic oil can only ensure the smooth start of the hydraulic system of construction machinery within the range of -20℃ to -25℃. However, within the temperature range of -30℃ to -40℃, the kinematic viscosity of ultra-low temperature hydraulic oil will increase significantly, exceeding the viscosity limit required for the start of the hydraulic system, resulting in the inability of construction machinery to work smoothly in winter in some high-latitude areas. In such areas, in addition to having better anti-wear, anti-oxidation and anti-corrosion properties, the hydraulic oil for construction machinery is also particularly important for its low-temperature startability and low-temperature pumpability. Requirements for the hydraulic system of construction machinery in extremely cold areas: The hydraulic oil must have excellent low-temperature startability and suitable high-temperature hydraulic efficiency, so as to ensure that the construction machinery meets the requirements of the kinematic viscosity of the hydraulic oil being lower than the start-up limit under low-temperature conditions. Summary of the invention

[0003] In order to at least partially solve the technical problems existing in the above-mentioned prior art, an embodiment of the present invention provides an ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold areas and a preparation method thereof, so that when the hydraulic oil is used in engineering machinery in severe cold areas, it can have excellent low-temperature fluidity and viscosity-temperature properties, thereby meeting the oil demand for mobile hydraulic systems in severe cold areas.

[0004] As one aspect of the present invention, it relates to an ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold areas, which comprises the following constituent raw materials, measured by mass percentage: 80-89% of base oil, 10-19% of viscosity index improver, 0.3-1.0% of antiwear agent, 0.1-1.5% of antioxidant, 0.01-0.15% of calcium-based additive, 0.005-0.02% of demulsifier, and 0.005-0.02% of defoaming agent.

[0005] In one or some possible embodiments, the base oil is selected from a base oil having a kinematic viscosity of 2.0 to 5.0 mm at 100°C. 2 / s Group II base oil and / or Group III base oil.

[0006] In one or some possible embodiments, the viscosity index improver is a mixture of linear polymethacrylate and comb-like polymethacrylate having an SSI index of less than 40 in any ratio.

[0007] In one or some possible embodiments, the linear polymethacrylate is as shown in formula (I):

[0008]

[0009] In formula (I), the value range of m is 200-300; the molecular weight range of R is 10-300.

[0010] In one or some possible embodiments, the comb-shaped polymethacrylate is as shown in formula (II):

[0011]

[0012] In formula (II), the molecular weight of R is in the range of 5000 to 10000.

[0013] In one or some possible embodiments, the anti-wear agent is selected from one or more of dibutyl phosphite, tricresyl phosphate or triphenyl thiophosphate.

[0014] In one or some possible embodiments, the antioxidant is 2,6-di-tert-butyl mixed phenol and / or butyl octyl diphenylamine.

[0015] In one or some possible embodiments, the calcium-based additive is selected from one or more of dinonylnaphthalene sulfonate, salicylate or sulphurized alkyl phenol salt.

[0016] In one or some possible embodiments, the demulsifier is a polyether demulsifier.

[0017] In one or some possible embodiments, the defoaming agent is a silicon-containing composite antifoaming agent.

[0018] In one or some possible embodiments, the kinematic viscosity of the zinc-free hydraulic oil at 40°C is 28.8-31.2 mm 2 / s, viscosity index not less than 250, pour point not exceeding -45℃.

[0019] As another aspect of the present invention, it relates to a method for preparing the ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions, the method comprising the following steps:

[0020] S1. Under stirring conditions, add base oil, viscosity index improver, antiwear agent, antioxidant and calcium-based additive in sequence, and heat and mix;

[0021] S2. Under stirring conditions, continue to add demulsifier and defoamer to the mixed solution prepared in S1 in sequence to obtain ultra-low temperature zinc-free hydraulic oil.

[0022] The ultra-low temperature zinc-free hydraulic oil specially used for engineering machinery in severe cold regions of the present invention has excellent low temperature fluidity and viscosity-temperature properties. The kinematic viscosity of the oil product is less than 1500mm at -30°C. 2 / s; at -40℃, the kinematic viscosity is less than 4500mm 2 / s, which is suitable for the oil demand of mobile hydraulic systems in some high-latitude areas (where the lowest temperature in winter is close to -40℃).

[0023] The ultra-low temperature zinc-free hydraulic oil specially used for engineering machinery in severe cold regions prepared in the present invention has excellent high temperature detergency. The zinc-free hydraulic oil can maintain a clear and transparent appearance, a stable acid value at a low level, and an extremely low sludge content under high temperature and long-cycle operating conditions.

[0024] The ultra-low temperature zinc-free hydraulic oil specially used for engineering machinery in severe cold regions of the present invention adopts a compounding method of linear and comb-shaped polymethacrylate viscosity index improvers, which can effectively reduce the amount of viscosity index improver (hereinafter referred to as "viscosity index improver") in the oil product, thereby improving the shear stability of the hydraulic oil and keeping the shear stability of the tapered roller below 20%. DETAILED DESCRIPTION

[0025] The following is a detailed description of the embodiments of the present invention: The embodiments of the present invention are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and processes are given, but the protection scope of the present invention is not limited to the following embodiments. The process parameters for which specific conditions are not specified in the following embodiments are generally based on conventional conditions.

[0026] The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0027] The inventors referred to patents CN111218325A, CN111019743A, CN110484339A, CN109652178A, CN108977260A and CN102757841A, implemented relevant technical solutions, and found that the ultra-low temperature hydraulic oils prepared by them were not as good as their expectations. Therefore, the inventors made the present invention through further research and development.

[0028] 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 the materials mainly involved in the examples are shown in Table 1 below, and other materials not shown are conventional commercial products.

[0029] Table 1 Material source description

[0030] Serial number materials Model / Specification factory 1 Triphenyl phosphorothioate T309 Jinzhou Shengda University 2 Tricresyl phosphate T306 Shandong Polychemical 3 Dibutyl phosphite T304 Hebei Tuochi 4 2,6-Di-tert-butyl mixed phenol T502A Jinzhou Runda 5 Butyl octyl diphenylamine L57 Xinxiang Ruifeng 6 Calcium dinonylnaphthalenesulfonate 729 King 7 Calcium alkyl phenol sulfide 115B Xinxiang Ruifeng 8 Linear polymethacrylate SCR178A Shenyang Great Wall 9 Comb polymethacrylate VPL3-195 Evonik

[0031] The hydraulic oils prepared in the following examples or comparative examples are all prepared by the following steps:

[0032] Add base oil, viscosity modifier, anti-wear agent, antioxidant and calcium-based additive to the blending kettle in sequence, heat and stir for 0.5-1 hour; then add demulsifier to the mixed liquid and stir for 0.5-1 hour; finally, add defoamer and stir for 0.5-1 hour to obtain hydraulic oil product.

[0033] Example 1

[0034] The constituent materials and contents of the zinc-free hydraulic oil of this embodiment are shown in Table 2:

[0035] Table 2 Material composition and content of Example 1

[0036]

[0037] Example 2

[0038] The constituent materials and contents of the zinc-free hydraulic oil of this embodiment are shown in Table 3:

[0039] Table 3 Material composition and content of Example 2

[0040]

[0041]

[0042] In the process of experimental research, the inventor made some changes to the raw materials of hydraulic oil in order to make up for the disadvantages of hydraulic oil in cold regions as much as possible. Now, the experimental objects with average or poor effects are selected as comparative examples of the present invention. The following are comparative examples 1 to 3 of the present invention.

[0043] Comparative Example 1

[0044] The constituent raw materials and contents of the zinc-free hydraulic oil of this comparative example are shown in Table 4:

[0045] Table 4 Material composition and content of Comparative Example 1

[0046]

[0047]

[0048] Comparative Example 2

[0049] The constituent raw materials and contents of the zinc-free hydraulic oil of this comparative example are shown in Table 5:

[0050] Table 5 Material composition and content of comparative example 2

[0051]

[0052] Comparative Example 3

[0053] The constituent raw materials and contents of the zinc-free hydraulic oil of this comparative example are shown in Table 6:

[0054] Table 6 Material composition and content of comparative example 3

[0055]

[0056] Comparative Example 4

[0057] The constituent raw materials and contents of the zinc-free hydraulic oil of this comparative example are shown in Table 7:

[0058] Table 7 Comparative Example 4 Material Composition and Content

[0059]

[0060]

[0061] The inventors conducted the following performance tests on Examples 1 to 2 and Comparative Examples 1 to 4, and recorded the performance test results of Examples 1 to 2 and Comparative Examples 1 to 4 in the following Tables 8 and 9, respectively.

[0062] Table 8 Performance test results of Examples 1 to 2

[0063]

[0064] Table 9 Performance test results of comparative examples 1 to 4

[0065]

[0066] Through Examples 1 to 2 and Comparative Examples 1 to 4, and in combination with the performance test results in Tables 8 and 9, we can see that:

[0067] By comparing Example 1 and Comparative Example 1, it can be seen that when blending ultra-low temperature hydraulic oils with the same 40°C kinematic viscosity and viscosity index, the shear stability of the traditional linear viscosity index agent solution is 38%, which is significantly higher than the shear stability value (24%) of the linear and comb-shaped compounding solution. This shows that the beneficial effect of the compounding of linear and comb-shaped viscosity index agents is that the shear stability of the oil is significantly improved. Similarly, by comparing Example 2 and Comparative Example 2, it can be seen that when blending ultra-low temperature hydraulic oils with the same 40°C kinematic viscosity, the scheme of using a comb-shaped viscosity index agent alone has a kinematic viscosity of 21.35 at 40°C, which is significantly lower than the kinematic viscosity of 31.65 of the linear and comb-shaped compounding solution at 40°C. It shows that the beneficial effect of compounding linear and comb-shaped viscosity index agents ensures that the oil has both excellent low-temperature fluidity and viscosity-temperature properties, and improves the adaptability of the oil to all seasons.

[0068] In addition, through Examples 1 to 2 and Comparative Examples 1 to 2, we can also find that: when linear polymethacrylate viscosity modifier or comb-shaped polymethacrylate viscosity modifier is used alone or not, the effect of one or more of the viscosity-temperature property, low-temperature fluidity and shear stability of the oil products prepared therefrom is weaker than the performance effect of using the two viscosity modifiers in combination.

[0069] In summary, the ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold areas prepared by the present invention has excellent low-temperature starting performance, excellent viscosity-temperature performance, water separation, air release, anti-foaming, shear stability and high-temperature cleanliness, etc., and can meet the requirements of cold starting of engineering machinery in high-latitude cold areas and no oil change in all seasons.

[0070] The above are only preferred feasible embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Various modifications or applications made according to the above embodiments are within the protection scope of this technical solution.

[0071] Although the specific embodiments of the present invention have been described in detail, it will be understood by those skilled in the art. According to all the teachings disclosed, various modifications and replacements can be made to those details, and these changes are all within the protection scope of the present invention. The full scope of the present invention is given by the attached claims and any equivalents thereof.

Claims

1. An ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions, characterized in that: Calculated by mass percentage, the composition comprises the following raw materials: 80-89% of base oil, 10-19% of viscosity index improver, 0.3-1.0% of antiwear agent, 0.1-1.5% of antioxidant, 0.01-0.15% of calcium-based additive, 0.005-0.02% of demulsifier and 0.005-0.02% of defoaming agent.

2. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 1, characterized in that: The base oil is selected from a base oil having a kinematic viscosity of 2.0 to 5.0 mm at 100°C. 2 / s Group II base oil and / or Group III base oil.

3. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 1, characterized in that: The SSI index improver is a mixture of linear polymethacrylate and comb-shaped polymethacrylate in any ratio, the viscosity index of which is less than 40.

4. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 3, characterized in that: The linear polymethacrylate is as shown in formula (I): In formula (I), the value range of m is 200-300; the molecular weight range of R is 10-300.

5. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 3, characterized in that: The comb-shaped polymethacrylate is shown in formula (II): In formula (II), the molecular weight of R is in the range of 5000 to 10000.

6. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 1, characterized in that: The anti-wear agent is selected from one or more of dibutyl phosphite, tricresyl phosphate or triphenyl thiophosphate.

7. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 1, characterized in that: The antioxidant is 2,6-di-tert-butyl mixed phenol and / or butyl octyl diphenylamine.

8. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 1, characterized in that: The calcium-based additive is selected from one or more of dinonylnaphthalene sulfonate, salicylate or sulphurized alkyl phenol salt.

9. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 1, characterized in that: The demulsifier is a polyether demulsifier.

10. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 1, characterized in that: The defoaming agent is a silicon-containing composite antifoaming agent.

11. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions according to claim 1, characterized in that: The kinematic viscosity of the zinc-free hydraulic oil at 40°C is 28.8-31.2 mm 2 / s, viscosity index not less than 250, pour point not exceeding -45℃.

12. A method for preparing the ultra-low temperature zinc-free hydraulic oil for engineering machinery in severe cold regions as claimed in any one of claims 1 to 11, characterized in that: The method comprises the following steps: S1. Under stirring conditions, add base oil, viscosity index improver, antiwear agent, antioxidant and calcium-based additive in sequence, and heat and mix; S2. Under stirring conditions, continue to add demulsifier and defoamer to the mixed solution prepared in S1 in sequence to obtain ultra-low temperature zinc-free hydraulic oil.

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