A range-extended hybrid engine oil lubricating oil composition and its preparation method

Abstract

This invention discloses a lubricating oil composition for range-extended hybrid engines and its preparation method. The raw materials of the lubricating oil composition include 6.8-10.1% of a secondary alkyl ZDDP anti-wear composite additive, 2.7-7% of a viscosity index improver, 0.12-0.5% of an organic molybdenum salt, 0.3-0.6% of a functional pour point depressant polymethyl methacrylate, and the balance being base oil. The base oil contains 10-15% by mass of oil-soluble polyether base oil. Based on obtaining a low-viscosity oil, this invention introduces an oil-soluble polyether base oil and an organic molybdenum salt for compounding. When applied to a range-extended hybrid engine, it effectively reduces the average coefficient of friction (less than 0.1) of the low-viscosity oil even with a low dosage of organic molybdenum salt. Simultaneously, it achieves good high-temperature oxidation resistance, preventing premature aging of the organic molybdenum salt during use and thus avoiding a decline in the oil's anti-wear and friction-reducing properties.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil technology, and particularly relates to a range-extended hybrid engine oil lubricating oil composition and its preparation method. Background Technology

[0002] Hybrid electric vehicles (HEVs) offer significant performance advantages over traditional gasoline-powered vehicles. With improved product capabilities and lower prices, they are gradually replacing traditional gasoline-powered vehicles in consumer demand. Because hybrid vehicles combine a gasoline engine and an electric motor, their operating principle differs greatly from that of traditional vehicles, thus requiring different engine oils. This is mainly reflected in:

[0003] (1) Frequent switching between oil and electricity leads to frequent engine start-stop, which can easily cause cold start wear.

[0004] (2) In order to quickly respond to the power generation demand, the engine often needs to reach the high-efficiency power generation speed in a very short time after starting, forming a huge speed and load gradient, which poses a severe test to the oil film strength and shear resistance.

[0005] (3) As a range extender, the engine usually operates near a fixed high efficiency point. The overall heat load may be lower than that of a traditional engine that runs at continuous high speed. However, frequent start-stop causes large fluctuations in oil temperature and easily accumulates fuel diluents and condensate, leading to problems such as emulsification, low-temperature deposition and acid corrosion.

[0006] Furthermore, since range extenders operate under high-load power generation conditions for extended periods, engine oils must possess excellent high-temperature stability. Currently, traditionally formulated oils suffer from issues such as insufficient anti-wear performance, inadequate high-temperature oxidation resistance, and insufficient control over moisture and low-temperature deposits. Moreover, new energy vehicle manufacturers require further extension of oil lifespan, leading to a trend towards lower viscosity oils (such as 0W-16 or 0W-20) to reduce mechanical losses and improve thermal efficiency. Therefore, anti-wear protection at low viscosity is particularly important. Summary of the Invention

[0007] Purpose of the invention: The technical problem to be solved by the present invention is to provide a range-extended hybrid engine oil lubricating oil composition and its preparation method, so as to reduce the friction coefficient and improve the oxidation resistance and cleaning properties of the oil based on low viscosity oil.

[0008] Technical solution: The range-extended hybrid engine oil lubricating oil composition of the present invention comprises the following raw materials by mass fraction: 6.8~10.1% of secondary alkyl ZDDP anti-wear composite additive, 2.7~7% of viscosity index improver, 0.12~0.5% of organic molybdenum salt, 0.3~0.6% of functional pour point depressant polymethyl methacrylate, and the balance being base oil; wherein the base oil contains 10~15% by mass of oil-soluble polyether base oil.

[0009] Furthermore, the base oil of this lubricating oil composition also contains Group III base oil 100N, which accounts for 85-90% of the total base oil and has a viscosity index of not less than 125.

[0010] Furthermore, the organic molybdenum salt in the lubricating oil composition is selected from dinuclear dialkyl dithiocarbamate or trinuclear dialkyl dithiocarbamate, and the molybdenum content is 5-10%.

[0011] Furthermore, the secondary alkyl ZDDP anti-wear composite additive in the lubricating oil composition is selected from composite agent BT1260 or composite agent BT1303.

[0012] Furthermore, the viscosity index improver of the lubricating oil composition is selected from OCP type or HSD type viscosity index improvers, and the shear stability index SSI < 25.

[0013] The method for preparing the above-mentioned range-extended hybrid engine oil lubricating oil composition according to the present invention includes the following steps:

[0014] (1) Add viscosity index improver and functional pour point depressant polymethyl methacrylate to base oil, stir and mix well to obtain a mixture;

[0015] (2) Add secondary alkyl ZDDP anti-wear composite additive and organic molybdenum salt to the mixture in step (1), stir and mix evenly, filter and bottle the finished product.

[0016] Furthermore, in step (1) of the preparation method, the reaction temperature for stirring and mixing is 55~65℃, and the stirring and mixing time is 30~45min.

[0017] Furthermore, in step (2) of the preparation method, the reaction temperature for stirring and mixing is 55~65℃, and the stirring and mixing time is 20~30min.

[0018] Beneficial effects: Compared with the prior art, the significant advantage of the present invention is that, based on the base oil and viscosity index improver to obtain a low viscosity oil, the lubricating oil composition, by introducing oil-soluble polyether base oil and organic molybdenum salt for compounding, when applied to a range-extended hybrid engine, can effectively reduce the average coefficient of friction of the low viscosity oil (less than 0.1) under the condition of adding a low dose of organic molybdenum salt, while achieving good high-temperature oxidation resistance of the oil, avoiding premature aging of the organic molybdenum salt during the use of the oil and thus preventing a decrease in the anti-wear and friction-reducing performance of the oil. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below with reference to embodiments and comparative examples.

[0020] It should be noted that all raw materials used in this invention are commercially available. The sources of the raw materials used in the embodiments and comparative examples are shown in Table 1 below.

[0021] Table 1. Sources of raw materials used in the examples and comparative examples

[0022]

[0023] Example 1 (SQ 0W-20)

[0024] The raw material composition of the range-extended hybrid engine oil lubricating oil composition of Example 1 is shown in Table 2 below.

[0025] Table 2 Lubricating oil composition of Example 1

[0026]

[0027] Example 2 (SQ 0W-20)

[0028] The raw material composition of the range-extended hybrid engine lubricating oil composition in Example 2 is shown in Table 3 below.

[0029] Table 3 Lubricating oil composition of Example 2

[0030]

[0031] Example 3 (SQ 0W-16)

[0032] The raw material composition of the range-extended hybrid engine oil lubricating oil composition of Example 3 is shown in Table 4 below.

[0033] Table 4 Lubricating oil composition of Example 3

[0034]

[0035] Example 4 (SQ 0W-16)

[0036] The raw material composition of the range-extended hybrid engine oil lubricating oil composition of Example 4 is shown in Table 5 below.

[0037] Table 5. Lubricating oil composition of Example 4

[0038]

[0039] Comparative Example 1

[0040] The basic raw materials are the same as in Example 1, except that all of them use base oil 100N. The specific raw materials are shown in Table 6 below.

[0041] Table 6. Lubricating oil compositions of Comparative Example 1

[0042]

[0043] Comparative Example 2

[0044] The basic raw materials are the same as in Example 1, except that an ester base oil (diisodecyl adipate) with a friction coefficient lower than that of oil-soluble polyether base oil is used. The specific raw materials are shown in Table 7 below.

[0045] Table 7 Lubricating oil compositions of Comparative Example 2

[0046]

[0047] Comparative Example 3

[0048] The basic raw materials are the same as in Example 3, except that all of them use base oil 100N. The specific raw materials are shown in Table 8 below.

[0049] Table 8. Lubricating oil compositions of Comparative Example 3

[0050]

[0051] Comparative Example 4

[0052] The basic raw materials are the same as in Example 3, except that an ester base oil (diisodecyl adipate) with a friction coefficient lower than that of oil-soluble polyether base oil is used. The specific raw materials are shown in Table 9 below.

[0053] Table 9. Lubricating oil compositions of Comparative Example 4

[0054]

[0055] The lubricating oil compositions of the above embodiments and comparative examples of the present invention are all prepared using the following preparation process, that is, there is no difference in the preparation process, specifically including the following steps:

[0056] (1) Add viscosity index improver and functional pour point depressant polymethyl methacrylate to base oil in sequence, and stir and mix at 55~65℃ for 30~45min to obtain a mixture;

[0057] (2) Add secondary alkyl ZDDP anti-wear composite additive and organic molybdenum salt to the mixture in step (1), stir and mix at 55~65℃ for 20~30min, filter through a 5μ filter bag and bottle out the finished product.

[0058] Performance testing

[0059] The performance of the lubricating oil compositions prepared in the above examples and comparative examples was tested, and the results are shown in Tables 10 and 11 below. Among them, commercially available SP 0W-20 and SP 0W-16 are gasoline engine oils that meet API SP specifications.

[0060] Table 10 Performance test data of the embodiments

[0061] Table 11 Performance test data of the comparative example

[0062]

[0063] As shown in Table 10, the superior performance of the lubricating oil composition of the present invention is mainly reflected in the following aspects:

[0064] (1) Excellent anti-wear performance: The average friction coefficient of SRV is less than 0.1, and the iron content in the oil is less than 60ppm after 30,000km driving test (the iron content of existing products is more than 200ppm after 30,000km driving test).

[0065] (2) High temperature oxidation resistance: The increase in acid value after high temperature oxidation (180℃, 96h) is no more than 1.0mgKOH / g; the change rate of kinematic viscosity at 40℃ is no more than 5%; it can effectively reduce the formation of oxidation products and maintain the viscosity of the oil well.

[0066] (3) Excellent emulsification retention and anti-icing performance: the icing amount is less than 10%, which greatly reduces the risk of low-temperature blockage of the lubricating oil circuit.

[0067] Furthermore, as shown in Table 11, in Comparative Examples 1 and 3, no oil-soluble polyether was added to the base oil, resulting in a relatively high SRV friction coefficient. Additionally, the acid value and kinematic viscosity at 40°C of the oils changed significantly after the high-temperature oxidation test. In Comparative Examples 2 and 3, synthetic ester base oils with even lower friction coefficients were added for blending (Comparative Examples 2 and 4). Although the average friction coefficient of the oils decreased, it still did not reach below 0.1, which is higher than the low friction coefficient achieved by using oil-soluble polyether base oils. Furthermore, the freezing amount of the oils increased, thus affecting their low-temperature fluidity in the presence of water.

[0068] In addition to the above embodiments, the lubricating oil compositions prepared using the raw materials and preparation process of the present invention can achieve the technical effects claimed above, and therefore no further testing is required to verify them.

Claims

1. A lubricating oil composition for a range-extended hybrid engine, characterized in that, The raw materials include, by mass fraction, the following: 6.8-10.1% of secondary alkyl ZDDP anti-wear composite additive, 2.7-7% of viscosity index improver, 0.12-0.5% of organic molybdenum salt, 0.3-0.6% of functional pour point depressant polymethyl methacrylate, and the balance being base oil; wherein the base oil contains 10-15% by mass of oil-soluble polyether base oil.

2. The range-extended hybrid engine oil lubricating oil composition according to claim 1, characterized in that, The base oil also contains Group III base oil 100N, which accounts for 85-90% of the total base oil and has a viscosity index of not less than 125.

3. The range-extended hybrid engine oil lubricating oil composition according to claim 1, characterized in that, The organic molybdenum salt is selected from dinuclear dialkyl dithiocarbamate or trinuclear dialkyl dithiocarbamate, and the molybdenum content is 5-10%.

4. The range-extended hybrid engine oil lubricating oil composition according to claim 1, characterized in that, The secondary alkyl ZDDP anti-wear composite additive is selected from composite agent BT1260 or composite agent BT1303.

5. The range-extended hybrid engine oil lubricating oil composition according to claim 1, characterized in that, The viscosity index improver is selected from OCP type or HSD type viscosity index improvers, and the shear stability index SSI < 25.

6. A method for preparing the range-extended hybrid engine lubricating oil composition of claim 1, characterized in that, Includes the following steps: (1) Add viscosity index improver and functional pour point depressant polymethyl methacrylate to base oil, stir and mix well to obtain a mixture; (2) Add secondary alkyl ZDDP anti-wear composite additive and organic molybdenum salt to the mixture in step (1), stir and mix evenly, then filter and bottle the finished product.

7. The method for preparing a range-extended hybrid engine oil lubricating oil composition according to claim 6, characterized in that, In step (1), the reaction temperature for stirring and mixing is 55~65℃, and the stirring and mixing time is 30~45min.

8. The method for preparing a range-extended hybrid engine oil lubricating oil composition according to claim 6, characterized in that, In step (2), the reaction temperature for stirring and mixing is 55~65℃, and the stirring and mixing time is 20~30min.

Images