Ultra-low temperature shear-resistant hydraulic oil composition and preparation method thereof

Abstract

The present invention relates to the technical field of hydraulic oil compositions, and in particular to an ultra-low-temperature, shear-resistant hydraulic oil composition and its preparation method. The composition comprises the following components in percentage by weight: 5.0-15.0% cycloalkyl or mineral base oil; 1.0-6.0% viscosity index improver; 0.3-2.5% antioxidant and preservative; 0.05-1.0% antioxidant; 0.01-1.0% rust inhibitor; 0.01-1.0% metal deactivator; 0.05-1.0% detergent; 0.0-0.1% antifoaming agent; and the balance, polyalphaolefin base oil. The formulated hydraulic oil provided by the present invention has excellent low-temperature performance, shear resistance, oxidation resistance, viscosity-temperature performance, and anti-wear properties, and is well suited for lubricating medium- and high-pressure hydraulic equipment in harsh operating conditions in severely cold regions.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic oil compositions, and in particular to an ultra-low temperature shear-resistant hydraulic oil composition and a preparation method thereof. Background Art

[0002] my country spans a vast territory, encompassing a wide range of cold and extremely cold regions, where winter temperatures can reach as low as -50°C. These regions present a severe challenge for hydraulic machinery operating outdoors in winter. Hydraulic oil, the lifeblood of hydraulic machinery, requires excellent low-temperature performance to meet the demanding operating conditions in these extreme cold regions. Furthermore, with the development of the domestic construction machinery industry, an increasing number of these equipment are being exported to Russia and even the Arctic Circle, placing stringent low-temperature performance requirements on the hydraulic oil used in these applications.

[0003] Hydraulic oil products can generally improve their low-temperature performance in the following ways. First, use base oils with better low-temperature performance. However, this method cannot meet the performance requirements of cold-region environments for hydraulic oils at low temperatures. On this basis, the low-temperature performance of hydraulic oils can be further improved by adding pour point depressants and viscosity index improvers. Currently, a large amount of viscosity index improvers are added to low-temperature hydraulic oil products on the market, which will lead to the deterioration of the hydraulic oil's shear resistance, making it easy to crack after cyclic high-speed shear, resulting in severe viscosity loss. This viscosity loss is usually irreversible, which will then weaken the hydraulic oil's lubrication and protection of mechanical equipment, causing severe wear of lubricated parts and shortening the service life of the equipment. Therefore, strict requirements are also placed on the shear resistance of hydraulic oil.

[0004] In cold regions, oil changes are more difficult, so hydraulic fluids must also possess excellent antioxidant properties to extend oil change cycles and reduce the inconvenience of oil changes in extremely cold regions. Furthermore, in summer and under exceptionally high-temperature conditions, the oil temperature rises during equipment operation, which in turn causes the oil's kinematic viscosity to decrease, thinning the oil film thickness and increasing friction in the lubricated parts. Therefore, the oil must also possess excellent viscosity-temperature properties to ensure that the viscosity is neither too high at low temperatures nor too low at high temperatures, maintaining the appropriate viscosity to protect the equipment. Considering these operating conditions, there is an urgent need to develop a hydraulic fluid with excellent low-temperature performance, shear resistance, antioxidant properties, viscosity-temperature performance, and anti-wear properties. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides an ultra-low temperature and shear-resistant hydraulic oil composition and a preparation method thereof. The ultra-low temperature and shear-resistant hydraulic oil composition provided by the present invention has excellent comprehensive performance in terms of low temperature performance, shear resistance, oxidation resistance, viscosity-temperature performance and anti-wear performance, and can meet the demanding working conditions of mechanical equipment in cold and extremely cold areas.

[0006] In a first aspect, the present invention provides an ultra-low temperature shear resistant hydraulic oil composition comprising the following components in percentage by weight:

[0007]

[0008] The present invention uses a synthetic base oil with superior performance to replace conventional mineral base oil. Then, by compounding antioxidants, anti-corrosion agents, antioxidants, rust inhibitors, metal deactivators and detergents, the antioxidant properties, extreme pressure and anti-wear properties, and corrosion resistance of the hydraulic oil are balanced. At the same time, the amount of viscosity index improver in the traditional formula is reduced to improve the shear resistance. In this way, an ultra-low temperature and shear-resistant hydraulic oil composition with excellent performance is developed.

[0009] Preferably, the cycloalkyl or mineral base oil is a T22 cycloalkyl base oil or an HVI Ib150 base oil; and / or, the polyalphaolefin base oil is a PAO6 base oil and a PAO10 base oil.

[0010] The addition of the cycloalkyl or mineral base oil in the present invention is Nynas Petroleum's T22 cycloalkyl base oil / Sinopec HVI Ib150 base oil, which can better increase the solubility of various additives in the synthetic base oil. The PAO base oil can be INEOS INEOS polyalphaolefin base oil, Mobil SpectraSyn polyalphaolefin base oil, or Maoming Petrochemical polyalphaolefin base oil. The base oils can be used alone or in combination, and base oils of different brands can be used alone or in combination. Based on the preferred base oil of the present invention, excellent low-temperature performance and antioxidant properties can be guaranteed, which can further extend the service life of the oil product. In particular, the polyalphaolefin base oil of the present invention, which is a further preferred combination of PAO6 base oil and PAO10 base oil, combined with the specific T22 cycloalkyl base oil / HVI Ib150 base oil and a specific additive system, to obtain a low-temperature, shear-resistant hydraulic oil composition with better overall performance than existing hydraulic transmission oil compositions.

[0011] More preferably, the viscosity index improver is a polymethacrylate, preferably Evonik VX7-310, Xinxiang Ruifeng RF6602, or Lubrizol LZ9340L. The viscosity index improver provided by the present invention can effectively improve the viscosity-temperature performance of the oil in this system, and at the same time, a suitable addition amount can significantly reduce the pour point of the oil.

[0012] More preferably, the antioxidant is zinc dialkyl dithiophosphate, preferably Jinzhou Kangtai KT2080, Wuxi Nanfang T203 or Xinxiang Ruifeng RF2203. Using the above antioxidants in the system in appropriate proportions can improve the antioxidant, anti-corrosion and anti-wear functions.

[0013] More preferably, the antioxidant is a mixture of an amine antioxidant and a phenolic antioxidant, preferably 2,6-di-tert-butylated cresol and an alkyl diphenylamine. 2,6-di-tert-butylated cresol is preferably Rhein Chemie RC7110 or BASF Irganox L135, while the alkyl diphenylamine is preferably Rhein Chemie RC7135 or BASF Irganox L57. The antioxidant described herein is a mixture of 2,6-di-tert-butylated cresol and alkyl diphenylamine, preferably in a ratio of 1:1.5. This antioxidant exhibits a synergistic effect with the aforementioned antioxidants and preservatives, significantly enhancing the antioxidant properties of the oil.

[0014] More preferably, the rust inhibitor is neutral barium dinonyl sulfonate and / or neutral zinc dinonyl naphthalene sulfonate, specifically Jinzhou Kangtai's T705A, Vanderbilt's Vanlube RI-ZSN, or King's Chemical's NA-SUL ZS. The rust inhibitor provided by the present invention exhibits excellent corrosion protection against a variety of metals in this system. Furthermore, neutral zinc dinonyl naphthalene sulfonate can improve the demulsification properties of hydraulic oil.

[0015] Further preferably, the metal deactivator is benzotriazole and its derivatives and / or thiadiazole derivatives, preferably Beijing Xingpu Fine Chemical T551, Huihua Petroleum T551, or BASF Irgamet 39. The metal deactivator provided by the present invention can better form a protective film on the metal surface in this system, inhibiting the catalytic effect of the metal or its ions on oxidation, and improving the antioxidant properties of the hydraulic oil.

[0016] More preferably, the detergent is an overbased calcium sulfated alkylphenate and / or an overbased calcium alkyl salicylate, preferably Jinzhou Kangtai BD P250, Wuxi Nanfang T122, or Xinxiang Ruifeng RF1122. The detergent provided by the present invention exhibits enhanced acid neutralization and high-temperature detergency in the system of the present invention, adsorbing small solid particles such as colloids and precipitates and dispersing them in the oil, preventing them from aggregating and forming large sediment particles.

[0017] More preferably, the antifoaming agent is a composite antifoaming agent, preferably composite antifoaming agent #1. Preferred is Jinzhou Donggong Petrochemical #1 antifoaming agent or Jinzhou Xinxing Petroleum #1 antifoaming agent. The antifoaming agent provided by the present invention can improve the antifoaming properties of hydraulic oil. Insufficient antifoaming agent can affect foaming properties and cause adverse effects such as insufficient oil supply. Excessive addition can affect the air release characteristics of the product.

[0018] Further preferably, the ultra-low temperature and shear resistant hydraulic oil composition provided by the present invention is preferably an ultra-low temperature and shear resistant hydraulic oil composition for use in severely cold areas (cold regions, extremely cold regions) or medium and high pressure hydraulic equipment under harsh working conditions.

[0019] In a second aspect, the present invention provides a method for preparing the ultra-low temperature shear resistant hydraulic oil composition, comprising mixing and stirring the components according to a proportion at 50-70° C. for 1-2 hours.

[0020] The present invention has at least the following beneficial effects: it utilizes a superior synthetic base oil and combines antioxidants, preservatives, antioxidants, rust inhibitors, metal deactivators, and detergents to balance the hydraulic oil's low-temperature performance, antioxidant properties, extreme pressure and anti-wear properties, and corrosion resistance. Furthermore, the present invention optimizes the dosages of the various components, such as reducing the amount of viscosity index improver in conventional formulations to further enhance shear resistance. The synergistic combination of specific base oil types and dosages and additive components results in a product with excellent low-temperature performance, shear resistance, antioxidant properties, viscosity-temperature performance, and anti-wear properties. This product is particularly suitable for lubricating medium- and high-pressure hydraulic equipment in extremely cold regions or under demanding operating conditions. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0022] If specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in the field or in the product instructions shall be followed. The implementation conditions in the examples can be further adjusted according to specific experimental conditions or factory conditions. If the implementation conditions are not specified, they are generally those in routine experiments.

[0023] Unless otherwise specified, the materials and reagents used in the following examples are commercially available. In the examples of the present invention, the polymethacrylate is Evonik VX7-310, the zinc dialkyl dithiophosphate is Jinzhou Kangtai KT2080, 2,6-di-tert-butyl-p-cresol and alkyl diphenylamine are Rhein Chemie RC7110 and RC7135, respectively, the neutral barium dinonylsulfonate is Jinzhou Kangtai T705A, the metal deactivator is Beijing Xingpu Fine Chemicals T551, the high base value sulfurized alkyl phenate calcium is Jinzhou Kangtai BDP250, and the antifoaming agent is Jinzhou Donggong Petrochemical No. 1 composite antifoaming agent.

[0024] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0025] Example 1

[0026] The ultra-low temperature and shear-resistant hydraulic oil composition provided in this embodiment has the following formula and preparation method: polymethacrylate (1.5 kg), zinc dialkyl dithiophosphate (0.5 kg), 2,6-di-tert-butyl-p-cresol (0.15 kg), alkyl diphenylamine (0.3 kg), neutral zinc dinonylnaphthalenesulfonate (0.05 kg), benzotriazole (0.05 kg), high base value sulfurized alkyl phenate calcium (0.1 kg), T22 cycloalkyl base oil (8 kg), PAO6 base oil (44.35 kg), PAO10 base oil (45 kg), mixed and stirred at a constant temperature of 60 ° C for 1 hour, then added 1# composite antifoaming agent (0.005 kg) and mixed and stirred for 1 hour to prepare an ultra-low temperature and shear-resistant hydraulic oil composition. The analytical data are shown in Table 1.

[0027] Example 2

[0028] The ultra-low temperature and shear-resistant hydraulic oil composition provided in this embodiment has the following formula and preparation method: polymethacrylate (2.5 kg), zinc dialkyl dithiophosphate (0.5 kg), 2,6-di-tert-butyl-p-cresol (0.15 kg), alkyl diphenylamine (0.3 kg), neutral barium dinonylsulfonate (0.05 kg), thiadiazole (0.05 kg), high base number alkyl salicylate calcium (0.1 kg), HVIIb150 base oil (5 kg), PAO6 base oil (62.35 kg), PAO10 base oil (29 kg), mixed and stirred at a constant temperature of 60 ° C for 1 hour, then added 1# composite antifoaming agent (0.005 kg) and mixed and stirred for 1 hour to prepare an ultra-low temperature and shear-resistant hydraulic oil composition. The analytical data are shown in Table 1.

[0029] Example 3

[0030] The ultra-low temperature and shear-resistant hydraulic oil composition provided in this embodiment has the following formula and preparation method: polymethacrylate (4 kg), zinc dialkyl dithiophosphate (0.5 kg), 2,6-di-tert-butyl-p-cresol (0.1 kg), alkyl diphenylamine (0.15 kg), neutral zinc dinonylnaphthalenesulfonate (0.03 kg), benzotriazole (0.05 kg), high base number alkyl salicylate calcium (0.1 kg), HVI Ib150 base oil (5 kg), PAO6 base oil (69.07 kg), PAO10 base oil (21 kg), mixed and stirred at a constant temperature of 60 ° C for 1 hour, then added 1# composite antifoaming agent (0.005 kg) and mixed and stirred for 1 hour to prepare an ultra-low temperature and shear-resistant hydraulic oil composition. The analytical data are shown in Table 1.

[0031] Comparative Example 1

[0032] Polymethacrylate (10 kg), polymethacrylate (0.5 kg), zinc dialkyl dithiophosphate (0.5 kg), 2,6-di-tert-butyl-p-cresol (0.1 kg), alkyl diphenylamine (0.15 kg), neutral zinc dinonylnaphthalenesulfonate (0.03 kg), benzotriazole (0.05 kg), high base value sulfurized alkyl phenate calcium (0.1 kg), S4 base oil (62.97 kg), and S6 base oil (25.6 kg) were mixed and stirred at a constant temperature of 60°C for 1 hour, and then 1# composite antifoaming agent (0.005 kg) was added and mixed and stirred for 1 hour to prepare an ultra-low temperature shear-resistant hydraulic oil composition. The analytical data are shown in Table 1.

[0033] Comparative Example 2

[0034] Hydraulic oil compound LZ 5703 (0.85 kg), polymethacrylate (9.4 kg), dioctyldiphenylamine (0.2 kg), polyalphaolefin base oil PAO6 (30 kg), cycloalkyl base oil NS3 (8.5 kg), and mineral oil II2 (51.05 kg) were mixed and stirred at a constant temperature of 60°C for 1 hour, and then 1# composite antifoaming agent (0.005 kg) was added and mixed and stirred for 1 hour to prepare an ultra-low temperature and shear-resistant hydraulic oil composition. The analytical data are shown in Table 1.

[0035] Table 1 Performance analysis data of examples and comparative examples

[0036]

[0037] After analysis, the low-temperature kinematic viscosity (-18°C) of the hydraulic oil obtained in Examples 1 to 3 is close to that of Comparative Example 1, but the pour point can reach -63°C, or even -66°C, which is significantly lower than that of the comparative example, indicating that the low-temperature performance of the examples is better. The viscosity grade of Comparative Example 2 is 32, so its kinematic viscosity (-18°C) is relatively low, but its pour point is only -54°C, which is not as good as that of Examples 1 to 3. Secondly, while the low-temperature performance of the present invention is significantly improved, it is also more excellent in terms of comprehensive performance. For example, the rotary oxygen bomb value of the hydraulic oil obtained in Examples 1 to 3 is relatively high, reaching more than 500min, while that of Comparative Examples 1 to 2 is about 400min, indicating that the antioxidant performance of the examples is better. In addition, the KRL shear analysis results show that the kinematic viscosity loss rate of the hydraulic oil obtained in Examples 1 to 3 after shear is small, and is much smaller than the viscosity loss rate of Comparative Examples 1 to 2, indicating that the shear resistance of the examples is very good.

[0038] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. An ultra-low temperature shear-resistant hydraulic oil composition, characterized in that: The composition includes the following weight percentages: Naphthenic or mineral base oil 5.0~15.0%; Viscosity index improver 1.0~6.0%; Antioxidant preservative 0.3~2.5%; Antioxidant 0.05~1.0%; Rust inhibitor 0.01~1.0%; Metal deactivator 0.01~1.0%; Detergent 0.05~1.0%; Antifoaming agent 0.0~0.1%; Polyalphaolefin base oil balance; The cycloalkyl or mineral base oil is a T22 cycloalkyl base oil or an HVI Ib150 base oil; the polyalphaolefin base oil is a PAO6 base oil and a PAO10 base oil; the antioxidant and corrosion inhibitor is a zinc dialkyl dithiophosphate; the antioxidant is 2,6-di-tert-butyl-p-cresol and an alkyl diphenylamine; the rust inhibitor is a neutral barium dinonylsulfonate and / or a neutral zinc dinonylnaphthalenesulfonate; the metal deactivator is a benzotriazole and its derivatives and / or a thiadiazole derivative; the detergent is an overbased sulfurized alkyl phenate calcium and / or an overbased alkyl calcium salicylate; and the viscosity index improver is a polymethacrylate.

2. The ultra-low temperature shear resistant hydraulic oil composition according to claim 1, characterized in that: The mass ratio of the 2,6-di-tert-butyl-p-cresol to the alkyl diphenylamine is 1:1-2.

3. The ultra-low temperature shear resistant hydraulic oil composition according to claim 1, characterized in that: The antifoaming agent is a composite antifoaming agent.

4. The ultra-low temperature shear resistant hydraulic oil composition according to claim 3, characterized in that: The antifoaming agent is 1# composite antifoaming agent.

5. The method for preparing the ultra-low temperature shear resistant hydraulic oil composition according to any one of claims 1 to 4, characterized in that: The process comprises mixing and stirring the components according to a proportion at 50-70° C. for 1-2 hours.

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