A hydraulic retarder lubricating oil composition and a preparation method thereof

Abstract

The present invention relates to the field of lubricating oil technology, and in particular to a hydraulic retarder lubricating oil composition and its preparation method. The composition comprises the following components by weight: 0.01 to 6.5 parts of a detergent dispersant, 0.1 to 2.0 parts of an antioxidant, 0.1 to 2.5 parts of a phosphorus-containing antiwear agent, 0.01 to 1.0 parts of a metal deactivator, 0.01 to 0.5 parts of a pour point depressant, 0.01 to 0.1 parts of an antifoaming agent, 0.1 to 20.0 parts of a viscosity index improver, and 60 to 85 parts of a base oil; the base oil being composed of a hydrogenated base oil and an ester base oil in a weight ratio of 4 to 24:1. The hydraulic retarder lubricating oil composition of the present invention can combine good thermal oxidation stability, antifoaming performance, low-temperature performance, and rubber compatibility, meeting the lubrication and sealing requirements of the hydraulic retarder during long-term use.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oils, and in particular to a hydraulic retarder lubricating oil composition and a preparation method thereof. Background Art

[0002] As an auxiliary braking device, the hydraulic retarder can slow down the vehicle, stabilize its speed, and improve driving safety when the vehicle is traveling downhill for a long time. When large vehicles (such as heavy trucks and buses) are traveling in mountainous areas or passing through areas with long slopes, the operation of the hydraulic retarder can effectively reduce the wear and heat caused by braking, thereby extending the service life of the brake pads. Therefore, the hydraulic retarder is one of the important systems for safe vehicle driving. The stator of the hydraulic retarder is usually integrated with the retarder housing, and the rotor is connected to the transmission drive shaft. Blades are cast on both the rotor and stator. When the hydraulic retarder is operating, oil is filled into the working chamber between the stator and rotor. The rotation of the rotor, which is connected to the transmission drive shaft, drives the oil to generate torque. The stator blades generate reverse torque on the oil and resistance on the rotor, thereby braking the transmission drive shaft.

[0003] Due to the differences in structure and operating conditions between hydraulic retarders and vehicle transmissions, lubricants for hydraulic retarders prioritize performance over load-bearing performance, necessitating the development of a dedicated lubricant for hydraulic retarders. During hydraulic retarder braking, the vehicle's kinetic energy is converted into heat through the interaction between the oil and the hardware and internal friction within the oil. This increases the oil temperature, necessitating excellent thermal and oxidative stability. Furthermore, because the impellers in a hydraulic retarder are constantly rotating and stirring during operation, the retarder oil must exhibit excellent anti-foaming properties to prevent the formation of excessive foam that can affect braking and lubrication. Vehicles operating in all seasons require retarder oils with excellent low-temperature performance. Furthermore, rubber materials are widely used in hydraulic retarders for seals (such as seals and gaskets). Rubber materials (such as nitrile rubber, hydrogenated nitrile rubber, and fluororubber) readily dissolve or swell in oil, leading to poor sealing and leakage. This can affect torque transmission and braking, and may even cause the retarder to cease functioning properly. Therefore, the rubber compatibility of retarder oil is crucial to the long-term use of the hydraulic retarder. Summary of the Invention

[0004] The present invention provides a hydraulic retarder lubricating oil composition, so as to achieve retarder oil having good thermal oxidation stability, anti-foaming performance, low-temperature performance and rubber compatibility.

[0005] First, the present invention provides a hydraulic retarder lubricating oil composition, comprising the following components in parts by weight:

[0006] 0.01-6.5 parts detergent dispersant, 0.1-2.0 parts antioxidant, 0.1-2.5 parts phosphorus antiwear agent, 0.01-1.0 parts metal deactivator, 0.01-0.5 parts pour point depressant, 0.01-0.1 parts antifoaming agent, 0.1-20.0 parts viscosity index improver, 60-85 parts base oil;

[0007] The base oil is composed of hydrogenated base oil and ester base oil in a weight ratio of 4 to 24:1.

[0008] The present invention has found that in the above-mentioned composition system, by controlling the weight ratio of hydrogenated base oil to ester base oil to 4 to 24:1, the lubricating oil system can have excellent sealing material compatibility, effectively reduce the aging degree of rubber parts, and achieve the purpose of extending the service life of rubber seals.

[0009] At the same time, the present invention also found that the ratio of hydrogenated base oil and ester base oil in the lubricating oil composition will affect the effect of the antioxidant, thereby affecting the thermal oxidation stability of the hydraulic retarder lubricating oil.

[0010] When the base oil with the above ratio is used, the hydraulic retarder lubricating oil composition can have good thermal oxidation stability, anti-foaming performance, low-temperature performance and rubber compatibility.

[0011] As a preferred embodiment of the present invention, the base oil is composed of hydrogenated base oil and ester base oil in a weight ratio of 6.3 to 14:1.

[0012] Under the above ratio, the thermal oxidation stability and rubber compatibility of the lubricating oil composition are further improved.

[0013] As a preferred embodiment of the present invention, the ester base oil is at least one of adipic acid diester or polyol ester.

[0014] As a preferred embodiment of the present invention, the hydrogenated base oil is HVI III6.

[0015] As a preferred embodiment of the present invention, the hydraulic retarder lubricating oil composition comprises the following components in parts by weight:

[0016] 0.01-4.0 parts of detergent dispersant, 0.5-1.5 parts of antioxidant, 0.1-2.1 parts of phosphorus-containing antiwear agent, 0.01-1.0 parts of metal deactivator, 0.01-0.5 parts of pour point depressant, 0.01-0.1 parts of antifoaming agent, 0.1-20.0 parts of viscosity index improver, and 60-85 parts of the base oil.

[0017] As a preferred embodiment of the present invention, the hydraulic retarder lubricating oil composition comprises the following components in parts by weight:

[0018] 1.2-5.5 parts of detergent dispersant, 0.8-1.5 parts of antioxidant, 1.0-2.1 parts of phosphorus-containing antiwear agent, 0.01-0.6 parts of metal deactivator, 0.1-0.3 parts of pour point depressant, 0.02-0.06 parts of antifoaming agent, 10-18 parts of viscosity index improver, and 65-78 parts of the base oil.

[0019] As a preferred embodiment of the present invention, the hydraulic retarder lubricating oil composition comprises the following components in parts by weight:

[0020] 5-5.5 parts of detergent dispersant, 0.8-1.2 parts of antioxidant, 1.8-2.1 parts of phosphorus-containing antiwear agent, 0.03-0.08 parts of metal deactivator, 0.2-0.3 parts of pour point depressant, 0.02-0.06 parts of antifoaming agent, 14-18 parts of viscosity index improver, 64-67 parts of hydrogenated base oil and 8-10 parts of ester base oil.

[0021] As a preferred embodiment of the present invention, the hydraulic retarder lubricating oil composition comprises the following components in parts by weight:

[0022] 5.1 parts of detergent dispersant, 1.02 parts of antioxidant, 2.1 parts of phosphorus-containing antiwear agent, 0.05 parts of metal deactivator, 0.3 parts of pour point depressant, 0.05 parts of antifoaming agent, 16 parts of viscosity index improver, 75.4 parts of base oil; the base oil is composed of hydrogenated base oil and ester base oil in a weight ratio of 6.8:1.

[0023] As a preferred embodiment of the present invention, the weight ratio of the hydrogenated base oil, the ester base oil and the antioxidant is 64-69:5-10:1.

[0024] The present invention further discovered that when the ratio of hydrogenated base oil, ester base oil and antioxidant is controlled within the above range, the compounding of hydrogenated base oil and ester base oil can promote the antioxidant to exert its antioxidant effect while ensuring excellent rubber compatibility, thereby significantly improving the thermal oxidation stability of the lubricating oil.

[0025] As a preferred embodiment of the present invention, the detergent dispersant is at least one of calcium sulfonate and boronated succinimide;

[0026] and / or, the antioxidant is at least one of dialkyldiphenylamine and phenolic antioxidants;

[0027] And / or, the phosphorus-containing antiwear agent is at least one of phosphite and phosphate antiwear agents;

[0028] and / or, the metal deactivator is at least one of a benzotriazole derivative and an alkylthiadiazole;

[0029] and / or, the pour point depressant is a polyacrylate;

[0030] and / or, the viscosity index improver is a polymethacrylate viscosity index improver;

[0031] And / or, the anti-foaming agent is a mixture of polymethyl silicone oil, acrylate and ether copolymer.

[0032] As a preferred embodiment of the present invention, based on the total weight of the lubricating oil composition as 100%, the hydraulic retarder lubricating oil composition consists of the following components:

[0033] 2.3-2.5wt% of synthetic calcium sulfonate; 2.6-2.8wt% of boronated polyisobutylene succinimide; 0.3-0.5wt% of 2,6-di-tert-butylphenol; 0.5-0.8wt% of dialkyl diphenylamine; 0.9-1.3wt% of aryl phosphate; 0.8-1.2wt% of alkyl phosphite; 0.03-0.07wt% of alkyl thiadiazole; 0.1-0.5wt% of polyacrylate Vx1-300; 14-18wt% of polymethacrylate Vx 0-030; 0.03-0.07wt% of composite antifoaming agent BAN 155; 5-10wt% of adipic acid diester or polyol ester; and the balance being HVI III6.

[0034] Furthermore, the present invention provides a method for preparing the above-mentioned hydraulic retarder lubricating oil composition, comprising:

[0035] The components except the antifoaming agent are mixed and reacted at 50-65°C, and then the reaction product is mixed with the antifoaming agent and reacted at 50-65°C.

[0036] As a preferred embodiment of the present invention, the components other than the antifoaming agent are mixed and reacted at 50-65° C. for 2-3 hours, and then the reaction product is mixed with the antifoaming agent and reacted at 50-65° C. for 0.5-1.5 hours, preferably 1 hour.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The hydraulic retarder lubricating oil composition of the present invention can have good thermal oxidation stability, anti-foaming performance, low-temperature performance and rubber compatibility, and can meet the lubrication and sealing requirements of the hydraulic retarder during long-term use.

[0039] In particular, it can significantly improve the rubber compatibility of oil products, so that before and after the rubber compatibility test, the tensile strength change rate, volume change rate and other indicators of rubber parts are significantly reduced, thereby significantly reducing the aging degree of rubber parts and achieving the purpose of extending the service life of rubber seals. At the same time, it can also have excellent thermal oxidation stability, anti-foaming performance and low-temperature performance. DETAILED DESCRIPTION

[0040] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0041] Where specific techniques or conditions are not specified in the examples, all methods were performed according to conventional methods, techniques or conditions described in literature in the field, or according to product specifications. Reagents and instruments used, for which the manufacturers are not specified, are conventional products that can be purchased through regular channels.

[0042] Examples 1 to 6

[0043] This embodiment provides a hydraulic retarder lubricating oil composition, the specific components of which are shown in Table 1. The preparation method is:

[0044] Add all components except the antifoaming agent into the reactor, mix them in a predetermined ratio, stir them in a heated reactor at 55° C. for 3 hours, then add the antifoaming agent in a predetermined ratio and continue stirring for 1 hour.

[0045] Comparative Example 1

[0046] This comparative example provides a hydraulic retarder lubricating oil composition, the specific components of which differ from those of Example 2 only in that the base oil components are all hydrogenated base oil HVI III6, without adipate diester, and the total amount of base oil remains unchanged. The specific components are shown in Table 1. The preparation method is the same as that of Example 2.

[0047] Comparative Example 2

[0048] This comparative example provides a hydraulic retarder lubricating oil composition, the specific components of which are shown in Table 1. The preparation method is the same as that in the example.

[0049] Table 1

[0050]

[0051]

[0052] Test example

[0053] The properties of the lubricating oil compositions prepared in the above examples and comparative examples were tested.

[0054] The compatibility of lubricating oils with rubber was evaluated using NB / SH / T 0877, "Lubricating Oil-Rubber Compatibility Test Method," with nitrile rubber and fluororubber. The thermal oxidative stability of lubricating oils used in automotive transmissions was evaluated using CEC L-48-00, "Oxidation stability of lubricating oils used in automotive transmissions by artificial aging."

[0055] The test results are shown in Table 2.

[0056] Table 2

[0057]

[0058]

[0059] As can be seen from the table above, the lubricating oil compositions in the examples contain appropriate ratios of hydrogenated base oil and ester base oil, and therefore have excellent rubber compatibility compared to the comparative examples. Moreover, increasing the proportion of ester oil within a certain range can further improve the rubber compatibility of the oil.

[0060] The combination of hydrogenated and ester base oils also creates a synergistic effect with antioxidants, improving the oil's thermal oxidative stability. By controlling the base oil ratio, both excellent thermal oxidative stability and rubber compatibility can be achieved.

[0061] In addition, the apparent viscosity, pour point and foam tendency data show that the lubricating oil composition of the examples has good anti-foaming performance.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A hydraulic retarder lubricating oil composition, characterized in that: The lubricating oil composition is composed of the following components based on the total weight of the lubricating oil composition as 100%: 2.5wt% of synthetic calcium sulfonate; 2.6wt% of boronated polyisobutylene succinimide; 0.3wt% of 2,6-di-tert-butylphenol; 0.72wt% of dialkyl diphenylamine; 1.1wt% of aromatic phosphate; 1wt% of alkyl phosphite; 0.05wt% of alkyl thiadiazole; 0.3wt% of polyacrylate Vx1-300; 16wt% of polymethacrylate Vx 0-030; 0.05wt% of composite antifoaming agent BAN 155; 9.7wt% of diester of adipic acid and the balance HVI III6.

2. The method for preparing the hydraulic retarder lubricating oil composition according to claim 1, characterized in that: include: The components except the antifoaming agent are mixed and reacted at 50-65°C, and then the reaction product is mixed with the antifoaming agent and reacted at 50-65°C.

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