A kind of extremely low temperature energy-saving and environmentally friendly hydraulic circulating oil and preparation method thereof

Abstract

The present invention relates to the technical field of lubrication of extremely low temperature equipment, and specifically to an extremely low temperature energy-saving and environment-friendly hydraulic circulating oil and a preparation method thereof. The hydraulic circulating oil comprises, by weight, 5-20 parts of alkyl naphthalene; 64-80 parts of a functional fluid containing a low-viscosity, low-volatility poly-alpha olefin base material; 10-15 parts of a hydrocarbon polymer fluid containing an ester functional group; 0.8-1.5 parts of a composite additive; 0.03-0.1 parts of a demulsifier; and 0.01-0.05 parts of a defoamer. The hydraulic circulating oil greatly improves the flash point of the oil while ensuring low-temperature starting performance and low-temperature fluidity, effectively reduces the evaporation loss of the oil, effectively balances the low-temperature and high-temperature performances of the oil, expands the application field and lubrication reliability of the extremely low-temperature oil, can meet the lubrication requirements in an extremely low-temperature working environment, and has a good energy-saving effect.

Description

Technical Field

[0001] The invention relates to an extremely low-temperature energy-saving and environment-friendly hydraulic circulating oil and a preparation method thereof, belonging to the technical field of lubrication of equipment operating at extremely low temperatures. Background Art

[0002] With the advancement of science and technology, new equipment is constantly being used in aerospace, ultra-low temperature development, deep sea and other ultra-low temperature fields. In recent years, industries such as wind power generation, offshore and ultra-low temperature oil and gas, and Arctic shipping have also achieved considerable development. China has a vast territory. In high-latitude and high-altitude areas such as the Three Norths and the Qinghai-Tibet Plateau, the winter temperature may drop below -40°C. With the large-scale offshore expansion of Chinese wind power companies, high-latitude central and northern Asian plateaus, Gobi and deep sea projects are constantly being built. The overall operating environment of these wind farms is also relatively harsh, and many wind turbines operate in low temperature environments. This requires that the various subsystems of wind turbines can also operate reliably in low temperature environments. In some high-latitude countries and regions with cold climates, the temperature is generally around -30°C, and in winter it will drop below -50°C. The ultra-low temperature is generally around -50°C, and the ambient temperature at the aircraft's flight altitude can be as low as -55°C.

[0003] Various equipment operating in extremely low temperature environments, such as aerospace vehicles, extremely low temperature equipment and vehicles, military equipment, oil and gas mining and transmission equipment, open-pit mining equipment, wind turbines, etc., have higher requirements on the performance of lubricants. The lubricants for the above equipment include hydraulic system oil, aviation special oil, low temperature circulation oil, low temperature sealing oil, low temperature shock absorber oil, engine oil, etc. These oils must have outstanding low temperature cold start capabilities and viscosity-temperature characteristics to meet the requirements of equipment operating under extremely low temperature conditions. At the same time, they must have good high temperature antioxidant stability, low volatility loss, etc.; since most of the above equipment works in sensitive environments, the biodegradability of the oil must be considered to avoid damage to the fragile environment caused by oil leakage.

[0004] The available low-temperature lubricants include low-temperature hydraulic oil, aviation oil, shock absorber oil, etc. For example, Shell SHELLTELLUS S4 VX 32, domestic ultra-low temperature hydraulic oil, Lanxess ROYCO 756 aviation oil, etc., generally use low-flash point hydrogenated light fractions as the main components. They have good low-temperature performance and can meet the lubrication requirements under low-temperature conditions, but the flash point is generally 90-100°C, which poses certain safety hazards; the evaporation loss of oil products is also relatively high. There are also low-viscosity PAO solutions. For example, PAO2 is used as the base oil in Chinese patent application CN110484339A. The flash point of the hydraulic oil can be effectively improved, but the viscosity-temperature performance is still insufficient. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an extremely low-temperature energy-saving and environment-friendly hydraulic circulating oil and a preparation method thereof. The hydraulic circulating oil greatly improves the flash point of the oil while ensuring low-temperature starting performance and low-temperature fluidity, effectively reduces the evaporation loss of the oil, and effectively balances the low-temperature and high-temperature performances of the oil, thereby expanding the application field and lubrication reliability of the extremely low-temperature oil, can meet the lubrication requirements in an extremely low-temperature working environment, and has a good energy-saving effect.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: an ultra-low temperature energy-saving and environmentally friendly hydraulic circulating oil, which comprises, by weight, 5-20 parts of alkyl naphthalene; 64-80 parts of a functional fluid containing a low-viscosity and low-volatility poly-alpha olefin base material; 10-15 parts of a hydrocarbon polymer fluid containing an ester functional group; 0.8-1.5 parts of a composite additive; 0.03-0.1 parts of a demulsifier; and 0.01-0.05 parts of a defoaming agent.

[0007] Furthermore, the alkyl naphthalene is selected from alkyl naphthalene having a kinematic viscosity of 20-100 cst at 40°C.

[0008] Furthermore, the functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base material is oligomeric alpha-olefin MAX3.5.

[0009] Furthermore, the kinematic viscosity of the hydrocarbon polymer fluid containing ester functional groups at 100° C. is 750-1500 mm 2 / s, pour point is lower than -20℃.

[0010] Furthermore, the hydrocarbon polymer fluid containing ester functional groups is selected from at least one of VISCOPLEX 7-182, VISCOPLEX 7-200, VISCOPLEX 7-302, VISCOPLEX 7-305, VISCOPLEX 7-310, VISCOPLEX 7-510 and VISCOPLEX 7-610.

[0011] Further, the composite additive is HITEC 543, IRGALUBE 3010A or a composite additive package consisting of an antioxidant, an extreme pressure anti-wear agent, a rust inhibitor, and a corrosion inhibitor;

[0012] The mass contents of various components in the composite additive package are: antioxidant 40-60%, extreme pressure anti-wear agent 30-50%, rust inhibitor 5-10%, and corrosion inhibitor 1-5%.

[0013] Furthermore, the antioxidant is selected from at least two of phenolic antioxidants, aniline antioxidants, naphthylamine antioxidants, or composite antioxidants of polymer phenol and aniline, composite antioxidants of polymer phenol and naphthylamine antioxidants, and composite antioxidants of polymer phenol, aniline, and naphthylamine antioxidants, and must contain phenolic antioxidants; the antioxidants function to improve the antioxidant capacity of oil products, reduce harmful deposits such as sludge and paint film, inhibit viscosity growth, and extend service life.

[0014] The extreme pressure anti-wear agent is at least one of a phosphate ester extreme pressure anti-wear agent and a phosphate amine extreme pressure anti-wear agent; the extreme pressure anti-wear agent is a pure organic substance and does not contain any inorganic components; the function of the extreme pressure anti-wear agent is to reduce equipment wear, improve the extreme pressure and anti-wear capabilities of the oil under low oil film coverage, and reduce equipment friction damage.

[0015] The rust inhibitor is at least one of organic amines, nitrogen-containing heterocyclic compounds, succinic acid half esters, liquid organic carboxylic acids, and sarcosine; the rust inhibitor is a pure organic substance and does not contain inorganic substances; the function of the rust inhibitor is to form a dense protective film on the metal surface to prevent equipment from rusting.

[0016] The corrosion inhibitor is selected from at least one of benzotriazole, methylbenzotriazole or its derivatives. The corrosion inhibitor protects non-ferrous metals in equipment, including copper, aluminum and alloys thereof, and reduces chemical or electrochemical metal corrosion.

[0017] Furthermore, the demulsifier is an oil-soluble nonionic surfactant;

[0018] The defoaming agent is at least one of an organosilicon defoaming agent and a non-organosilicon defoaming agent.

[0019] Preferably, the defoamer is a combination of an organosilicon defoamer and a non-organosilicon defoamer.

[0020] Further, the mass ratio of the alkyl naphthalene to the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material is (3.2-5.5):1;

[0021] The mass ratio of the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material to the hydrocarbon polymer fluid containing the ester functional group is (4.5-6.0):1.

[0022] The present invention also discloses a method for preparing an extremely low temperature energy-saving and environment-friendly hydraulic circulating oil, the preparation method comprising:

[0023] S1, adding a functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and a hydrocarbon polymer fluid containing an ester functional group into a blending kettle, and heating and stirring the mixture evenly;

[0024] S2, adding composite additives, demulsifier and defoamer into the blending kettle and mixing them evenly;

[0025] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm to obtain the energy-saving and long-life hydraulic circulating oil.

[0026] The beneficial effects of the present invention are:

[0027] The hydraulic circulating oil of the present invention can greatly improve the flash point of the oil while ensuring low-temperature starting performance and low-temperature fluidity, effectively reduce the evaporation loss of the oil, effectively balance the low-temperature and high-temperature performance of the oil, expand the application field and lubrication reliability of the extremely low-temperature oil, and in addition to meeting the lubrication requirements in extremely low-temperature working environments, the hydraulic circulating oil of the present invention can also be used as an energy-saving lubricant. At the same time, due to the use of green and environmentally friendly materials, the biodegradation rate of the oil is improved, which helps to prevent environmental pollution caused by leakage and is conducive to the protection of sensitive environments and fragile ecosystems.

[0028] Alkyl naphthalene base oil is added to the hydraulic circulating oil of the present invention. The electron-rich naphthalene ring in the alkyl naphthalene base oil can absorb oxygen, thereby interrupting the transmission of the oxidation chain, preventing the continued oxidation of hydrocarbons, and preventing the occurrence of oxidation. In addition, the alkyl naphthalene base oil has extremely outstanding antioxidant properties, and the electron-rich naphthalene ring structure has a strong polarity, and has good solubility and dispersibility for polar additives. Based on the special electron-rich naphthalene ring structure of alkyl naphthalene, it and the regular oligomeric alpha olefin structure will form a mutual synergistic effect, which can not only give play to the highly saturated and excellent high-temperature oxidation resistance of the oligomeric alpha olefin structure, but also have the strong polarity and water resistance of alkyl naphthalene. The present invention selects the functional fluid of the alkyl naphthalene base oil and the unsaturated low-viscosity and low-volatility polyalpha olefin base material as the base oil combination to achieve the best beneficial effect.

[0029] The hydraulic circulating oil of the present invention has good sensitivity to various additives by means of a suitable proportion of alkyl naphthalene, a functional fluid containing a poly-alpha olefin base material with low viscosity and low volatility, and a hydrocarbon polymer fluid containing an ester functional group. In addition, the hydraulic circulating oil can have excellent high and low temperature performance and excellent low temperature fluidity, can meet the lubrication requirements in an extremely low temperature working environment, and has a good energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the test principle diagram of MTM micro traction test machine;

[0031] Figure 2 for Figure 2 This is the test result diagram of MTM micro traction test machine. DETAILED DESCRIPTION

[0032] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0034] The invention discloses an extremely low temperature energy-saving and environment-friendly hydraulic circulating oil. The hydraulic circulating oil comprises, by weight, 5-20 parts of alkyl naphthalene; 64-80 parts of a functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base material; 10-15 parts of a hydrocarbon polymer fluid containing an ester functional group; 0.8-1.5 parts of a composite additive; 0.03-0.1 parts of a demulsifier; and 0.01-0.05 parts of a defoamer.

[0035] Specifically, the alkyl naphthalene is preferably an alkyl naphthalene produced by ExxonMobil Chemical, King's Chemical, and Doppler Chemical, and more preferably an alkyl naphthalene having a kinematic viscosity of 20-100 cst at 40°C.

[0036] Specifically, the functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base stock is oligomeric alpha-olefin MAX3.5 produced by ExxonMobil Chemical.

[0037] Specifically, the hydrocarbon polymer fluid containing ester functional groups has a kinematic viscosity of 750-1500 mm at 100°C. 2 / s, pour point is lower than -20℃.

[0038] More specifically, the hydrocarbon polymer fluid containing ester functional groups is selected from at least one of VISCOPLEX 7-182, VISCOPLEX 7-200, VISCOPLEX 7-302, VISCOPLEX 7-305, VISCOPLEX 7-310, VISCOPLEX 7-510 and VISCOPLEX 7-610.

[0039] Specifically, the composite additive is HITEC 543 produced by Afton Chemical, IRGALUBE3010A produced by BASF, or a composite additive package consisting of an antioxidant, an extreme pressure anti-wear agent, a rust inhibitor, and a corrosion inhibitor;

[0040] The mass contents of various components in the composite additive package are: antioxidant 40-60%, extreme pressure anti-wear agent 30-50%, rust inhibitor 5-10%, and corrosion inhibitor 1-5%.

[0041] Specifically, the antioxidant is selected from at least two of phenolic antioxidants, aniline antioxidants, naphthylamine antioxidants, or composite antioxidants of polymer phenol and aniline, composite antioxidants of polymer phenol and naphthylamine antioxidants, and composite antioxidants of polymer phenol, aniline, and naphthylamine antioxidants, and must contain phenolic antioxidants.

[0042] More specifically, the antioxidant is at least two of Irganox L 64, Irganox L 135, Irganox L 57, Irganox L115, Irganox L06, and BHT, and must contain at least one of Irganox L 135, Irganox L 115, and BHT.

[0043] Specifically, the extreme pressure anti-wear agent is at least one of a phosphate ester extreme pressure anti-wear agent and a phosphate amine extreme pressure anti-wear agent.

[0044] More specifically, the extreme pressure anti-wear agent is at least one of Durad 150B, Irgalube TPPT, Irgalube 232, Irgalube 349, and AdditinRC3760.

[0045] Specifically, the rust inhibitor is at least one of an organic amine, a nitrogen-containing heterocyclic compound, a succinic acid half ester, a liquid organic carboxylic acid, and sarcosine;

[0046] More specifically, the rust inhibitor is at least one of Sarkosyl O and Amine O.

[0047] Specifically, the corrosion inhibitor is selected from at least one of benzotriazole, methylbenzotriazole or their derivatives.

[0048] More specifically, the corrosion inhibitor is at least one of CUVAN 303, CUVAN 826, and Irgamet39.

[0049] Specifically, the demulsifier is an oil-soluble nonionic surfactant.

[0050] More specifically, the demulsifier is at least one of LZ5957 and PE10100.

[0051] Specifically, the defoaming agent is at least one of an organosilicon defoaming agent and a non-organosilicon defoaming agent.

[0052] Preferably, the defoaming agent is a combination of dimethyl silicone oil and polyacrylate.

[0053] Preferably, the mass ratio of the alkyl naphthalene to the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material is (3.2-5.5): 1;

[0054] The mass ratio of the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material to the hydrocarbon polymer fluid containing the ester functional group is (4.5-6.0):1.

[0055] A method for preparing an extremely low-temperature energy-saving and environment-friendly hydraulic circulating oil, the preparation method comprising:

[0056] S1, adding a functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and a hydrocarbon polymer fluid containing an ester functional group into a blending kettle, and heating and stirring the mixture evenly;

[0057] S2, adding composite additives, demulsifier and defoamer into the blending kettle and mixing them evenly;

[0058] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm to obtain the energy-saving and long-life hydraulic circulating oil.

[0059] Example 1

[0060] The formula composition of the hydraulic circulating oil in this embodiment is shown in Table 1 below.

[0061] Table 1 Formula composition of Example 1

[0062]

[0063] The method for preparing the hydraulic circulating oil comprises the following steps:

[0064] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0065] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0066] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0067] Example 2

[0068] The formula composition of the hydraulic circulating oil in this embodiment is shown in Table 2 below.

[0069] Table 2 Formula composition of Example 2

[0070]

[0071] The method for preparing the hydraulic circulating oil comprises the following steps:

[0072] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0073] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0074] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0075] Example 3

[0076] The formula composition of the hydraulic circulating oil in this embodiment is shown in Table 3 below.

[0077] Table 3 Formula composition of Example 3

[0078]

[0079] The method for preparing the hydraulic circulating oil comprises the following steps:

[0080] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0081] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0082] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0083] Example 4

[0084] The formula composition of the hydraulic circulating oil in this embodiment is shown in Table 4 below.

[0085] Table 4 Formula composition of Example 4

[0086]

[0087] The method for preparing the hydraulic circulating oil comprises the following steps:

[0088] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0089] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0090] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0091] Example 5

[0092] The formula composition of the hydraulic circulating oil in this embodiment is shown in Table 5 below.

[0093] Table 5 Formula composition of Example 5

[0094]

[0095] The method for preparing the hydraulic circulating oil comprises the following steps:

[0096] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0097] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0098] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0099] Example 6

[0100] The formula composition of the hydraulic circulating oil in this embodiment is shown in Table 6 below.

[0101] Table 6 Formula composition of Example 6

[0102]

[0103] The method for preparing the hydraulic circulating oil comprises the following steps:

[0104] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0105] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0106] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0107] Example 7

[0108] The formula composition of the hydraulic circulating oil in this embodiment is shown in Table 7 below.

[0109] Table 7 Formula composition of Example 7

[0110]

[0111] The method for preparing the hydraulic circulating oil comprises the following steps:

[0112] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0113] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0114] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0115] Comparative Example 1

[0116] The hydraulic circulating oil was prepared by the same method as in Example 1, except that no alkyl naphthalene was added. The formulation composition is shown in Table 8.

[0117] Table 8 Formula composition of comparative example 1

[0118]

[0119] The method for preparing the hydraulic circulating oil comprises the following steps:

[0120] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material and the hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0121] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0122] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0123] Comparative Example 2

[0124] The hydraulic circulating oil was prepared by the same method as in Example 1, except that the hydrocarbon polymer fluid containing ester functional groups was not added. The formulation composition is shown in Table 9 below.

[0125] Table 9 Formula composition of comparative example 2

[0126]

[0127] The method for preparing the hydraulic circulating oil comprises the following steps:

[0128] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material and alkyl naphthalene into the blending kettle, stir and heat at a stirring speed of 100 r / min, heat to 45° C., and stir for 1 hour;

[0129] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0130] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 15 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0131] Comparative Example 3

[0132] The hydraulic circulating oil was prepared by the same method as in Example 1, except that the amount of alkyl naphthalene was increased. The formulation composition is shown in Table 10.

[0133] Table 10 Formula composition of comparative example 3

[0134]

[0135] The method for preparing the hydraulic circulating oil comprises the following steps:

[0136] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0137] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0138] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0139] Comparative Example 4

[0140] The hydraulic circulating oil was prepared by the same method as in Example 1, except that the amount of the hydrocarbon polymer fluid containing ester functional groups was increased. The formulation composition is shown in Table 11.

[0141] Table 11 Formula composition of comparative example 4

[0142]

[0143] The method for preparing the hydraulic circulating oil comprises the following steps:

[0144] S1. Add the functional fluid containing low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and hydrocarbon polymer fluid containing ester functional group into the blending kettle, raise the temperature while stirring, the stirring speed is 100r / min, raise the temperature to 45°C, and stir for 1h;

[0145] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0146] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0147] Comparative Example 5

[0148] The hydraulic circulating oil was prepared by the same method as in Example 2, except that the functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base material was not added. The formulation composition is shown in Table 12 below.

[0149] Table 12 Formula composition of comparative example 5

[0150]

[0151] The method for preparing the hydraulic circulating oil comprises the following steps:

[0152] S1. Add hydrocarbon polymer fluid containing ester functional groups and alkyl naphthalene into a blending kettle, stir and heat at a speed of 100 r / min, heat to 45°C, and stir for 1 hour;

[0153] S2, adding composite additives, demulsifier and defoamer into the blending kettle, maintaining the temperature at 45°C and the stirring speed at 100 r / min, and stirring for 1 hour;

[0154] S3. After the blending is completed, the oil is filtered using a filter bag with a filter diameter not greater than 5 μm at a pressure of 0.2 MPa to obtain the hydraulic circulating oil.

[0155] The performance of the hydraulic circulating oil prepared in the above examples and comparative examples was tested, and the specific test results are shown in Tables 13 and 14. The test methods involved are:

[0156] Kinematic viscosity: ASTM D445;

[0157] Viscosity index: ASTM D2270;

[0158] Open cup flash point: ASTM D92;

[0159] Closed cup flash point: ASTM D93;

[0160] Pour point: ASTM D97;

[0161] Demulsification: ASTM D1401;

[0162] Foam properties: ASTM D892;

[0163] Copper corrosion: ASTM D130;

[0164] Liquid phase corrosion: ASTM D665;

[0165] FZG failure level: ASTM D5182;

[0166] Wear spot diameter D: ASTM D4172;

[0167] Brookfield viscosity: ASTM D2983;

[0168] Oxidation stability (TOST life): ASTM D943;

[0169] Rotating oxygen bomb: ASTM D2272;

[0170] Energy saving effect test method: The traction coefficient of air compressor oil is tested using the MTM micro traction tester produced by PCS in the UK. The test principle diagram of the MTM micro traction tester is as follows: Figure 1 As shown in the figure, the specific process is: put the oil to be tested into a steel pan, control the temperature of the oil through a heating element, and let the steel ball roll in the oil. During the test, the traction coefficient under different slide-roll ratio conditions at a certain temperature (60°C) is determined by changing the computer program, and a traction coefficient-slide-roll ratio curve is formed.

[0171] Table 13 Performance test data of hydraulic circulating oil in Examples 1-7

[0172]

[0173] Table 14 Performance test data of hydraulic circulating oil in comparative examples 1-5

[0174]

[0175] It can be seen from the above table data that the hydraulic circulating oil prepared by the preparation method of the present invention in Examples 1-7 has better high and low temperature performance and multi-grade viscosity characteristics, better high temperature oil film retention ability and anti-wear ability, and takes into account both low temperature fluidity and high temperature performance. At the same time, the more excellent antioxidant ability, anti-corrosion and anti-rust performance can also better protect the equipment. In addition, it can be seen from the data comparison of Examples 1-5 and Examples 6-7 that in Examples 1-5, the mass ratio of the alkyl naphthalene and the functional fluid containing the low viscosity and low volatility polyalphaolefin base material is (3.2-5.5): 1; the mass ratio of the functional fluid containing the low viscosity and low volatility polyalphaolefin base material and the hydrocarbon polymer fluid containing the ester functional group is (4.5-6.0): 1. Under the limitation of this ratio, the performance of the obtained hydraulic circulating oil is more excellent.

[0176] From the comparison of the data of Example 1 and Comparative Example 1, it can be seen that if alkyl naphthalene is not added to the formula composition, the anti-emulsification performance, anti-foaming performance, corrosion resistance, anti-wear ability and high and low temperature performance of the oil product are all reduced, especially the high and low temperature performance and anti-emulsification performance are significantly reduced.

[0177] From the comparison of the data of Example 1 and Comparative Example 2, it can be seen that if the hydrocarbon polymer fluid containing ester functional groups is not added to the formula composition, the anti-emulsification performance, anti-foaming performance, corrosion resistance, anti-wear ability and high and low temperature performance of the oil product will all decrease, especially the high and low temperature performance and anti-wear performance will decrease significantly.

[0178] From the comparison of the data of Example 1 and Comparative Example 3, it can be seen that if too much alkyl naphthalene is added to the formula, the anti-corrosion performance, anti-wear ability and high and low temperature performance of the oil product will all decrease.

[0179] From the comparison of the data of Example 1 and Comparative Example 4, it can be seen that if the amount of hydrocarbon polymer fluid containing ester functional groups added in the formula is too much, the anti-emulsification performance, anti-foaming performance, anti-corrosion performance, anti-wear ability and high and low temperature performance of the oil product will all decrease.

[0180] From the comparison of the data of Example 1 and Comparative Example 5, it can be seen that if the functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base material is not added to the formula composition, the anti-emulsification performance, anti-foaming performance, anti-corrosion performance, anti-wear ability and high and low temperature performance of the oil product are all reduced, especially the anti-emulsification performance, anti-foaming performance and low temperature performance are significantly reduced.

[0181] In addition, the present invention uses the MTM micro traction tester produced by PCS in the UK to test the traction coefficients of Example 1 and Comparative Examples 1, 2, 3, 4 and 5. The test principle diagram of the MTM micro traction tester is as follows: Figure 1 As shown in the figure, the specific process is: put the oil to be tested into a steel pan, control the temperature of the oil through a heating element, and let the steel ball roll in the oil. During the test, the traction coefficient under different slide-roll ratio conditions at a certain temperature (60°C) is determined by changing the computer program, and a traction coefficient-slide-roll ratio curve is formed.

[0182] Specific test results are as follows Figure 2 As shown by Figure 2 It can be seen that Example 1 of the lubricating oil of the present invention has the lowest traction coefficient and can provide the best energy efficiency. Compared with Comparative Example 5, the traction coefficient of Example 1 decreases by more than 50%, which can provide an improvement of more than 50% in energy efficiency.

[0183] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0184] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. An extremely low temperature energy-saving and environmentally friendly hydraulic circulating oil, characterized in that: According to the weight percentage, the hydraulic circulating oil comprises 5-20 parts of alkyl naphthalene; 64-80 parts of functional fluid containing low-viscosity and low-volatility poly-alpha olefin base material; 10-15 parts of hydrocarbon polymer fluid containing ester functional group; 0.8-1.5 parts of composite additives; 0.03-0.1 parts of demulsifier; 0.01-0.05 parts of defoamer; The functional fluid containing a low-viscosity, low-volatility poly-alpha-olefin base material is oligomeric alpha-olefin MAX3.5; The hydrocarbon polymer fluid containing ester functional groups has a kinematic viscosity of 750-1500 mm at 100°C. 2 / s, pour point is lower than -20℃; The mass ratio of the alkyl naphthalene to the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material is 1:(3.2-5.5); The mass ratio of the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material to the hydrocarbon polymer fluid containing the ester functional group is (4.5-6.0):

1.

2. The ultra-low temperature energy-saving and environment-friendly hydraulic circulating oil according to claim 1, characterized in that: The alkyl naphthalene is selected from alkyl naphthalene having a kinematic viscosity of 20-100 cst at 40°C.

3. The ultra-low temperature energy-saving and environment-friendly hydraulic circulating oil according to claim 1, characterized in that: The hydrocarbon polymer fluid containing ester functional groups is selected from at least one of VISCOPLEX 7-182, VISCOPLEX 7-200, VISCOPLEX 7-302, VISCOPLEX 7-305, VISCOPLEX 7-310, VISCOPLEX 7-510 and VISCOPLEX 7-610.

4. The ultra-low temperature energy-saving and environment-friendly hydraulic circulating oil according to claim 1, characterized in that: The composite additive is HITEC 543, 3010A or a composite additive package consisting of an antioxidant, an extreme pressure anti-wear agent, a rust inhibitor, and a corrosion inhibitor; The mass contents of various components in the composite additive package are: antioxidant 40-60%, extreme pressure anti-wear agent 30-50%, rust inhibitor 5-10%, and corrosion inhibitor 1-5%.

5. The ultra-low temperature energy-saving and environment-friendly hydraulic circulating oil according to claim 4, characterized in that: The antioxidant is selected from at least two of phenolic antioxidants, aniline antioxidants, naphthylamine antioxidants, or composite antioxidants of high molecular weight phenol and aniline, composite antioxidants of high molecular weight phenol and naphthylamine antioxidants, and composite antioxidants of high molecular weight phenol, aniline, and naphthylamine antioxidants, and must contain phenolic antioxidants; The extreme pressure anti-wear agent is at least one of a phosphate ester extreme pressure anti-wear agent and a phosphate amine extreme pressure anti-wear agent; The rust inhibitor is at least one of an organic amine, a nitrogen-containing heterocyclic compound, a succinic acid half ester, a liquid organic carboxylic acid, and sarcosine; The corrosion inhibitor is selected from at least one of benzotriazole, tolyltriazole or derivatives thereof.

6. The ultra-low temperature energy-saving and environment-friendly hydraulic circulating oil according to claim 1, characterized in that: The demulsifier is an oil-soluble nonionic surfactant; The defoaming agent is at least one of an organosilicon defoaming agent and a non-organosilicon defoaming agent.

7. A method for preparing an extremely low temperature energy-saving and environment-friendly hydraulic circulating oil according to any one of claims 1 to 6, characterized in that: The preparation method is: S1, adding a functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base material, alkyl naphthalene, and a hydrocarbon polymer fluid containing an ester functional group into a blending kettle, and heating and stirring the mixture evenly; S2, adding composite additives, demulsifier and defoamer into the blending kettle and mixing them evenly; S3. After the blending is completed, the hydraulic circulating oil is filtered using a filter bag with a filter diameter not greater than 15 μm to obtain the hydraulic circulating oil.

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