An ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions and a preparation method thereof

Abstract

This invention discloses an ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions and its preparation method. The hydraulic oil comprises the following raw materials by weight percentage: 65-75% base oil, 24-35% viscosity index improver, 0.3-1.0% anti-wear agent, 0.1-1.5% antioxidant, 0.01-0.1% rust inhibitor, 0.005-0.02% demulsifier, and 0.005-0.02% defoamer. The ultra-low temperature hydraulic oil for engineering machinery in extremely cold regions prepared by this invention uses polyalphaolefin and light white oil as the main raw materials, resulting in excellent low-temperature fluidity and viscosity-temperature properties. The oil has a viscosity index greater than 250 and a kinematic viscosity less than 1500 mmHg at -50°C. 2 With a pour point below -60°C, this ultra-low temperature hydraulic oil for engineering machinery in extremely cold regions ensures that the hydraulic system can start at -50°C and achieve rapid start-up at -40°C, making it highly suitable for mobile hydraulic systems in extremely cold regions, especially in Antarctica and the Arctic.

Description

TECHNICAL FIELD

[0001] The present application relates to an ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions and a preparation method thereof. BACKGROUND

[0002] Conventional ultra-low temperature hydraulic oil can only ensure the smooth start of the hydraulic system of engineering machinery in the range of-20℃ to-25℃. However, in the temperature range of-30℃ to-40℃, the kinematic viscosity of the ultra-low temperature hydraulic oil will significantly increase, exceeding the required viscosity limit for starting the hydraulic system, resulting in the inability of the engineering machinery to operate smoothly in extremely cold regions. In some extremely cold regions, such as the South Pole and the North Pole, the winter environmental temperature is very low, usually below-50℃. When engineering machinery is used in such regions, the ultra-low temperature hydraulic oil is often blended with Group III and / or Group IV base oil. However, the kinematic viscosity of the oil under extremely cold temperature conditions increases significantly, showing solidification or slow flow, which does not meet the winter cold start requirements of mobile hydraulic systems. SUMMARY

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

[0004] As an aspect of the present application, an ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions is provided, comprising the following raw materials by mass percentage: base oil 65-75%, viscosity index improver 24-35%, anti-wear agent 0.3-1.0%, antioxidant 0.1-1.5%, anti-rust agent 0.01-0.1%, demulsifier 0.005-0.02%, and defoaming agent 0.005-0.02%.

[0005] In one or some possible embodiments, the base oil is selected from light white oil with a kinematic viscosity of 1.5-5.0 mm 2 / s at 40℃.

[0006] In one or some possible embodiments, the viscosity index improver is selected from polyalphaolefin with a kinematic viscosity of 600 or 1000 mm 2 / s at 100℃.

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

[0008] In formula (I), the value of n is in the range of 50-200; and R is selected from long-chain alkanes with 8-12 carbon atoms.

[0009] In one or some possible embodiments, the anti-wear agent is selected from one or more of dibutyl phosphite, trimcresyl phosphate or triphenyl phosphorothionate.

[0010] In one or some possible embodiments, the antioxidant is 2,6-di-tert-butyl mixed phenol and / or butyloctyl diphenylamine.

[0011] In one or some possible embodiments, the anti-rust agent is calcium dinonylnaphthalene sulfonate and / or dodecenyl succinic acid half ester.

[0012] In one or some possible embodiments, the demulsifier is a polyether type demulsifier.

[0013] In one or some possible embodiments, the antifoaming agent is a silicon type composite antifoaming agent.

[0014] In one or some possible embodiments, the zinc-free hydraulic oil has a kinematic viscosity at 40℃ of 13.5-16.5mm 2 / s, a viscosity index not less than 250, and a pour point not more than -60℃.

[0015] As another aspect of the present application, a method for preparing the above-mentioned super-low-temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions is involved, and specifically comprises the following steps:

[0016] S1. Under stirring, sequentially adding base oil, viscosity index improver, anti-wear agent, antioxidant and anti-rust agent, and heating and mixing;

[0017] S2. Under stirring, sequentially adding demulsifier and antifoaming agent to the mixture prepared in S1 to obtain the super-low-temperature zinc-free hydraulic oil.

[0018] The super-low-temperature hydraulic oil for engineering machinery in extremely cold regions prepared by the present application uses poly-alpha olefin and light white oil as main raw materials, so that the oil product has excellent low-temperature fluidity and viscosity-temperature property. The oil product has a viscosity index greater than 250, a kinematic viscosity at -50℃ of less than 1500mm 2 / s, and a pour point lower than -60℃, and is suitable for mobile hydraulic systems in the South or North Pole regions.

[0019] The super-low-temperature hydraulic oil for engineering machinery in extremely cold regions of the present application can ensure that the hydraulic system has startability at -50℃, and can realize rapid start at -40℃, and is very suitable for mobile hydraulic systems in extremely cold regions, especially in the South and North Pole regions. DETAILED DESCRIPTION

[0020] The following detailed description of the embodiments of the present application is made on the premise of the technical solutions of the present application, and detailed implementation manners and processes are given, but the protection scope of the present application is not limited to the following embodiments. The process parameters not specified in the following embodiments are generally according to the conventional conditions.

[0021] The endpoints of the ranges and any values disclosed in the present application are not limited to the precise values stated. The ranges and values should be interpreted as approximations. The endpoints of the ranges and values are provided as a separate point for the convenience of the reader. The ranges and values are approximate values and are understood to be encompassed by the values within the range. The endpoints of the ranges of values presented are not to be understood as limited to the values released unless the context clearly indicates the contrary.

[0022] The inventors found that the kinematic viscosity and viscosity-temperature property of the ultra-low temperature hydraulic oil prepared according to the patents CN111218325A and CN111019743A do not meet the inventors' expectations under the condition of 100 DEG C. The inventors found that the low-temperature fluidity of the ultra-low temperature hydraulic oil prepared according to the patents CN109652178A, CN108977260A and CN102757841A do not meet the inventors' expectations under the condition of-50 DEG C. Therefore, the inventors made the present application through further research and development.

[0023] The present application uses poly-alpha olefin viscosity index improver (hereinafter referred to as "viscosity improver") and light white oil in combination, which are used as the main raw material of the ultra-low temperature hydraulic oil. The oil product has the advantages of low pour point and good low-temperature fluidity, and can be used to develop ultra-low temperature hydraulic oil with extremely low pour point and excellent low-temperature fluidity to meet the requirements of mobile hydraulic systems in extremely cold regions.

[0024] The present application will be further described in combination with specific embodiments, and the protection scope of the present application is not limited by the following embodiments. The main materials involved in the embodiments are shown in Table 1 below, and other materials not shown are conventional commercial products.

[0025] Table 1 Material Source Description

[0026]

[0027]

[0028] The hydraulic oil prepared in the following examples or comparative examples is prepared by the following steps:

[0029] The base oil, tackifier, anti-wear agent, antioxidant, anti-rust agent are added into a blending kettle in sequence, and heated and stirred for 0.5-1 hour; then the demulsifier is added into the mixture, and stirred for 0.5-1 hour; finally, the defoaming agent is added into the mixture, and stirred for 0.5-1 hour, to obtain the hydraulic oil product.

[0030] Example 1

[0031] The composition of the zinc-free hydraulic oil of the present example and the content of each component are shown in Table 2.

[0032] Table 2: Material composition and content of Example 1

[0033]

[0034]

[0035] Example 2

[0036] The composition of the zinc-free hydraulic oil of the present example and the content of each component are shown in Table 3.

[0037] Table 3: Material composition and content of Example 2

[0038]

[0039] Example 3

[0040] The composition of the zinc-free hydraulic oil of the present example and the content of each component are shown in Table 4.

[0041] Table 4: Material composition and content of Example 3

[0042]

[0043] Example 4

[0044] The composition of the zinc-free hydraulic oil of the present example and the content of each component are shown in Table 5.

[0045] Table 5: Material composition and content of Example 4

[0046]

[0047]

[0048] In the process of experimental exploration, the inventor made some changes to the composition of the hydraulic oil in order to maximize the compensation for the disadvantages of the hydraulic oil in extremely cold areas. The experimental objects with general or poor effects were selected as the comparative examples of the present application. The following are Comparative Examples 1-3 of the present application.

[0049] Comparative Example 1

[0050] The composition and content of the zinc-free hydraulic oil in this comparative example are shown in Table 6:

[0051] Table 6. Material composition and content of Comparative Example 1

[0052]

[0053] Comparative Example 2

[0054] The composition and content of the zinc-free hydraulic oil in this comparative example are shown in Table 7:

[0055] Table 7. Material composition and content of Comparative Example 2

[0056]

[0057] Comparative Example 3

[0058] The composition and content of the zinc-free hydraulic oil in this comparative example are shown in Table 8:

[0059] Table 8. Material composition and content of Comparative Example 3

[0060]

[0061]

[0062] The inventors conducted the following performance tests on Examples 1-4 and Comparative Examples 1-3, and recorded the performance test results of Examples 1-4 and Comparative Examples 1-3 in Tables 9 and 10 below, respectively.

[0063] Table 9 Performance test results of Examples 1-4

[0064]

[0065] Table 10 Performance test results for comparative examples 1-3

[0066]

[0067]

[0068] Based on the performance test results of Examples 1-4 and Comparative Examples 1-3, combined with Tables 9 and 10, it can be seen that: comparing Example 1 and Comparative Example 1, when blending ultra-low temperature hydraulic oils with the same kinematic viscosity at 40°C, using ultra-high viscosity PAO600 and light white oil results in a kinematic viscosity of 13.5-16.5 mm at 40°C. 2 The kinematic viscosity of ultra-low temperature hydraulic oil at -50℃ is less than 1500 mm³ / s. 2 / s, pour point below -60℃, blended with ultra-high viscosity PAO600 and Group III base oil, kinematic viscosity at 40℃ is 13.5~16.5mm. 2The -50℃ kinematic viscosity of the ultra-low temperature hydraulic oil is greater than 2500mm 2 The pour point is obviously higher than -60℃.

[0069] From comparative example 2 and comparative example 2, when blending the ultra-low temperature hydraulic oil with the same 40℃ kinematic viscosity, the 40℃ kinematic viscosity of the ultra-low temperature hydraulic oil blended by the ultra-high viscosity PAO 100 and the light white oil is between 13.5mm 2 / s, the -50℃ kinematic viscosity of the ultra-low temperature hydraulic oil is less than 1500mm 2 / s, the pour point is lower than -60℃, the 40℃ kinematic viscosity of the ultra-low temperature hydraulic oil blended by the traditional linear polymethyl methacrylate and the light white oil is between 13.5mm 2 / s, the -50℃ kinematic viscosity of the ultra-low temperature hydraulic oil is close to 1500mm 2 / s, but the pour point is obviously higher than -60℃.

[0070] Therefore, it can be considered that the light white oil and the ultra-high viscosity PAO can be used to blend the ultra-low temperature hydraulic oil with extremely low pour point, excellent low temperature fluidity and viscosity-temperature property; the scheme of the group III base oil and the ultra-high viscosity PAO and the light white oil and the linear polymethyl methacrylate cannot be used to blend the ultra-low temperature hydraulic oil with low temperature fluidity and viscosity-temperature property (the 40℃ kinematic viscosity is between 13.5mm 2 / s); the ultra-high viscosity PAO used as a viscosity pointer to blend the ultra-low temperature hydraulic oil can realize a lower pour point and further optimize the low temperature fluidity of the oil.

[0071] In summary, the ultra-low temperature hydraulic oil in the extremely cold region has excellent low temperature fluidity, viscosity-temperature property, water separation property, air release property and foam resistance, and is suitable for the mobile hydraulic system in the extremely cold region.

[0072] The above merely describes preferred and feasible embodiments of the present application, and is not intended to limit the protection scope of the present application, and various modifications or applications according to the above embodiments are within the protection scope of the technical scheme.

[0073] Although the specific embodiments of the present application have been described in detail, those skilled in the art will understand that various modifications and replacements can be made to those details according to all the teachings disclosed, and these changes are within the protection scope of the present application. The entire scope of the present application is given by the appended claims and any equivalents thereof.

Claims

1. A low-temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions, characterized in that, By weight percentage, it consists of the following raw materials: base oil 65-75%, viscosity index improver 24-35%, anti-wear agent 0.3-1.0%, antioxidant 0.1-1.5%, rust inhibitor 0.01-0.1%, demulsifier 0.005-0.02%, and defoamer 0.005-0.02%; the sum of the weight percentages of the above raw materials is 100%. The base oil is selected from oils with a kinematic viscosity of 1.5–5.0 mm at 40°C. 2 Light white oil between / s; The viscosity index improver is selected from those with a kinematic viscosity of 600 or 1000 mmHg at 100°C. 2 / s of polyalphaolefins; The zinc-free hydraulic oil has a kinematic viscosity of 13.5~16.5 mm at 40°C. 2 / s, viscosity index not less than 250, pour point not exceeding -60℃; kinematic viscosity at -50℃ less than 1500 mmHg. 2 / s.

2. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions according to claim 1, characterized in that, The polyalphaolefin is as shown in formula (I): （I）， In formula (I), the value of n ranges from 50 to 200; R is selected from long-chain alkanes from C8 to C12.

3. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely 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.

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

5. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions according to claim 1, characterized in that, The rust inhibitor is calcium dinonylnaphthalenesulfonate and / or dodecenyl succinate half ester.

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

7. The ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions according to claim 1, characterized in that, The defoamer is a silicone-based composite antifoamer.

8. A method for preparing ultra-low temperature zinc-free hydraulic oil for engineering machinery in extremely cold regions as described in any one of claims 1 to 7, characterized in that, The method includes the following steps: S1. Under stirring conditions, add base oil, viscosity index improver, anti-wear agent, antioxidant and rust inhibitor in sequence, and heat to mix; S2. Under stirring conditions, continue to add demulsifier and defoamer to the mixture obtained in S1 in sequence to obtain ultra-low temperature zinc-free hydraulic oil.

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