Friction modifier, preparation method thereof and lubricating oil

Abstract

The invention provides a friction modifier, a preparation method thereof and lubricating oil. The structure of the friction modifier is as shown in formula I # imgabs0 #, Ra comprises one or more of alkane, olefin and derivatives thereof, Rb comprises one or more of alkane, olefin and formula-O-CH2CH2-COR ', and-COR' is derived from C2-C20 fatty acid. A phosphatide group and an imide structure in the friction modifier form a polar cluster group, so that the adsorption strength with a friction material is improved, and the problem of dynamic shaking of a clutch is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating oil additives, and in particular relates to a friction modifier and a preparation method thereof, and lubricating oil. Background Art

[0002] Automotive lubricants are commonly found in engines and transmissions, serving to reduce friction, save energy, dissipate heat, and maintain cleanliness. However, electromechanical coupling transmission fluids for new energy vehicles must, in addition to the performance of traditional transmission fluids, possess suitable electrical properties, excellent corrosion protection, appropriate thermal management, compatibility with new materials, and friction properties that mitigate NVH. During vehicle startup and shifting, if there is vibration between the clutch friction plates, as speed increases, the driver will experience a sense of jerkiness or jitter, which can negatively impact the overall vehicle's visual quality and diminish the brand's image. Good friction properties are crucial for ensuring smooth operation of transmission gear components, reducing noise and extending lifespan.

[0003] During the use of existing lubricants, under sliding film conditions, that is, when the friction plate of a continuously sliding torque-converting clutch continuously changes in the clamping force, the torque does not show a linear correlation, but rather fluctuates at high frequencies, that is, the friction coefficient vibrates. Furthermore, there are the following problems: 1) On an SAE No. 2 friction tester, the static friction coefficient decreases significantly over the entire life cycle, that is, the torque capacity changes significantly, which is not conducive to the distribution of hydraulic system control pressure; (2) On a low-speed SAE No. 2 friction tester, NVH vibration problems are obvious; (3) On a ZF clutch performance tester, the dynamic pressure-torque exhibits severe vibration at 40°C. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: to provide a friction modifier and a preparation method thereof, and lubricating oil in response to the problem that the existing clutch using lubricating oil has dynamic jitter under speed difference.

[0005] In order to solve the above technical problems, on the one hand, the present invention provides a friction modifier, the structure of which is shown in Formula I:

[0006]

[0007] Among them, R a Including one or more of alkanes, alkenes and their derivatives, R b It includes one or more alkanes, alkenes, and the formula -O-CH2CH2-COR', where -COR' is derived from a C2-C20 fatty acid.

[0008] Optionally, the R a One selected from C1-C10 alkanes, C1-C10 alkenes and derivatives thereof.

[0009] Optionally, the R b One or more selected from C5-C30 alkanes, C5-C30 alkenes and the formula -O-CH2CH2-COR', wherein -COR' is derived from a C2-20 fatty acid.

[0010] Optionally, the number average molecular weight Mn of the friction modifier is 400-1500, and the molecular weight dispersion Mw / Mn of the friction modifier is 1.0-1.2.

[0011] Optionally, the number average molecular weight Mn of the friction modifier is 800-1200, and the molecular weight dispersion Mw / Mn of the friction modifier is 1.0-1.08.

[0012] On the other hand, the present invention also provides a method for preparing the friction modifier as described above, comprising the following steps: mixing an imide compound, a metal cyanide, a halogenated phosphate compound, an auxiliary agent, and a solvent, reacting to obtain a crude product of the friction modifier, and purifying the crude product to obtain a friction modifier as shown in Formula I; the halogenated phosphate compound is shown in Formula II, and the imide compound is shown in Formula III.

[0013]

[0014] Among them, R a Including one or more of alkanes, alkenes and their derivatives, R b It includes one or more alkanes, alkenes, and the formula -O-CH2CH2-COR', wherein -COR' is derived from a C2-C20 fatty acid, and X is selected from one or more of F, Cl, Br, and I.

[0015] Optionally, the metal cyanide comprises sodium cyanide.

[0016] Optionally, the imide compound is added dropwise to a solvent containing the metal cyanide at 0-4° C. to obtain a mixed solution after the addition of the imide compound is completed, and the mixed solution is reacted at 40-60° C. for 6-7 hours;

[0017] The halogenated phosphate compound is added dropwise to the mixed solution at 0-4° C. After the halogenated phosphate compound is added dropwise, the mixture is reacted at 40-60° C. for 7-8 hours.

[0018] Optionally, the molar ratio of the imide compound, the metal cyanide, the halogenated phosphate compound and the auxiliary agent is (2-2.1):(2-2.1):1:(0.05-0.1).

[0019] Optionally, the auxiliary agent includes a phenolic polymerization inhibitor, and the phenolic polymerization inhibitor includes hydroquinone.

[0020] Optionally, the solvent includes one or more of tetrahydrofuran, diethyl ether and dioxane.

[0021] On the other hand, the present invention further provides a lubricating oil comprising the friction modifier as described in any one of the above or the friction modifier prepared by the method for preparing the friction modifier as described in any one of the above.

[0022] Optionally, the static friction coefficient change rate of the friction characteristics test of the lubricating oil is less than 7%.

[0023] Optionally, the torque variation characteristic parameter of the lubricating oil in the NVH test is less than 10 N·m. Optionally, in the dynamic pressure-torque test, the torque variation characteristic parameter of the lubricating oil in the process of linear pressure variation from 0 to 12 bar is less than 2 N·m.

[0024] In this invention, the phospholipid groups of the friction modifier form polar clustering groups with the imide structure, enhancing adsorption strength with the friction material. Furthermore, the chain structures of the phospholipids and the imide form a polymer film between the shaft teeth, enhancing the friction cushioning effect and long-term stability of the lubricant. This friction modifier also exhibits properties such as wear reduction, copper corrosion inhibition, rust prevention, and emulsification stability. It integrates well with existing lubricant additive systems, has minimal impact on other properties, and exhibits excellent compatibility. Used in new energy DHT electromechanical coupling transmission lubricants, it exhibits excellent low-temperature activity, effectively resolving dynamic vibration issues and improving the rapid decrease in the static friction coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a graph showing the coefficient of kinetic friction of the lubricating oil of Comparative Example 1 on a SAE No. 2 friction tester;

[0026] Figure 2 This is a graph showing the static friction coefficient of the lubricating oil of Comparative Example 1 on a SAE No. 2 friction tester;

[0027] Figure 3 The μ0 / μ of the lubricating oil of Comparative Example 1 on the SAE No.2 friction tester d performance diagram;

[0028] Figure 4 This is a graph showing the coefficient of dynamic friction of the lubricating oil of Example 1 on an SAE No. 2 friction tester;

[0029] Figure 5 This is a graph showing the static friction coefficient of the lubricating oil of Example 1 on an SAE No. 2 friction tester;

[0030] Figure 6 is the μ0 / μ of the lubricating oil of Example 1 on the SAE No.2 friction tester d performance diagram;

[0031] Figure 7 This is a graph showing the vibration effect of the lubricating oil of Comparative Example 1 on a low-speed SAE No. 2 friction tester (rotation speed 20 r / min);

[0032] Figure 8 This is a graph showing the vibration effect of the lubricating oil of Comparative Example 1 on a low-speed SAE No. 2 friction tester (rotation speed 100 r / min);

[0033] Figure 9 This is a graph showing the vibration effect of the lubricating oil of Example 1 on a low-speed SAE No. 2 friction tester (rotation speed 20 r / min);

[0034] Figure 10 This is a graph showing the vibration effect of the lubricating oil of Example 1 on a low-speed SAE No. 2 friction tester (rotation speed 100 r / min);

[0035] Figure 11 This is a diagram showing the torque jitter of the lubricating oil of Comparative Example 1 on a ZF dual-motor friction tester;

[0036] Figure 12 This is a diagram showing the torque jitter of the lubricating oil of Example 1 on a ZF dual-motor friction tester. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0038] The friction modifier provided by the embodiment of the present invention has a structure as shown in Formula I:

[0039]

[0040] Among them, R a Including one or more of alkanes, alkenes and their derivatives, R b It includes one or more alkanes, alkenes, and the formula -O-CH2CH2-COR', where -COR' is derived from a C2-C20 fatty acid.

[0041] In this embodiment, the phospholipid groups of the friction modifier form polar clustering groups with the imide structure, enhancing adsorption strength with the friction material. Furthermore, the chain structures of the phospholipids and the imide form a polymer film between the shaft teeth, enhancing the friction cushioning effect and long-term stability of the lubricant. This friction modifier also exhibits properties such as wear reduction, copper corrosion inhibition, rust prevention, and emulsion stability. It integrates well with existing lubricant additive systems, has minimal impact on other properties, and exhibits excellent compatibility. Used in new energy DHT electromechanical coupling transmission lubricants, it exhibits excellent low-temperature activity, effectively addressing dynamic vibration issues and improving the rapid decrease in the static friction coefficient.

[0042] In some embodiments, the friction modifier R a One selected from C1-C10 alkanes, C1-C10 alkenes and derivatives thereof, wherein R b is selected from one or more of C5-C30 alkanes, C5-C30 alkenes and -O-CH2CH2-COR', wherein -COR' is derived from a C2-20 fatty acid. a Selected from C2-C6 alkanes, said R b Selected from C20-C25 olefins.

[0043] In some embodiments, the friction modifier has a number average molecular weight Mn of 400-1500, and a molecular weight dispersion Mw / Mn of 1.0-1.2. Specifically, Mw and Mn can be measured by any known method, typically by GPC (gel permeation chromatography).

[0044] In a preferred embodiment, the friction modifier has a number average molecular weight Mn of 800-1200 and a molecular weight dispersion Mw / Mn of 1.0-1.08. Within this molecular weight range, the phospholipid group and the imide structure form a polar clustering group, satisfying the structure shown in Formula I.

[0045] One embodiment of the present invention further provides a method for preparing the friction modifier as described in the above embodiment, comprising the following steps: mixing an imide compound, a metal cyanide, a halogenated phosphate compound, an additive, and a solvent, reacting to obtain a crude product of the friction modifier, and purifying the crude product to obtain a friction modifier as shown in Formula I; the halogenated phosphate compound is shown in Formula II, and the imide compound is shown in Formula III.

[0046]

[0047] Among them, R a Including one or more of alkanes, alkenes and their derivatives, R bThe compound includes one or more alkanes, alkenes, and the formula -O-CH2CH2-COR', wherein -COR' is derived from a C2-C20 fatty acid, and X is selected from one or more of F, Cl, Br, and I. Specifically, the purification method adopts column chromatography for separation and purification.

[0048] In some embodiments, the halogenated phosphate compound is selected from dichlorophosphate compounds. Specifically, the dichlorophosphate compounds include but are not limited to one or more of methyl dichlorophosphate, ethyl dichlorophosphate, and butyl dichlorophosphate, and the imide compounds include but are not limited to one or more of 2-pentane-succinimide, 2-hexene-succinimide, 2-(ethoxypropionate) succinimide, and 2-pentacosyl-succinimide.

[0049] In some embodiments, the imide compound is added dropwise to a solvent containing a metal cyanide at 0-4° C. to obtain a mixed solution, and the mixed solution is reacted at 40-60° C. for 6-7 hours;

[0050] The halogenated phosphate compound is added dropwise to the mixed solution at 0-4° C. After the halogenated phosphate compound is added dropwise, the mixture is reacted at 40-60° C. for 7-8 hours.

[0051] In a preferred embodiment, the imide compound is added dropwise to a solvent containing a metal cyanide at 0° C. to obtain a mixed solution after the addition of the imide compound is completed, and the mixed solution is reacted at 50° C. for 6 hours;

[0052] The halogenated phosphate compound was added dropwise to the mixed solution at 0° C. After the halogenated phosphate compound was added dropwise, the mixture was reacted at 50° C. for 8 hours.

[0053] In some embodiments, the metal cyanide includes but is not limited to sodium cyanide.

[0054] In some embodiments, the molar ratio of the imide compound, the metal cyanide, the halogenated phosphate compound, and the auxiliary agent is (2-2.1):(2-2.1):1:(0.05-0.1).

[0055] In some embodiments, the auxiliary agent includes a phenolic polymerization inhibitor, and the phenolic polymerization inhibitor includes hydroquinone, which prevents the halogenated phosphate compound from self-polymerizing.

[0056] In some embodiments, the solvent includes one or more of tetrahydrofuran, diethyl ether, and dioxane.

[0057] One embodiment of the present invention further provides a lubricating oil comprising the friction modifier as described above or the friction modifier prepared by the method for preparing the friction modifier as described above.

[0058] In some embodiments, based on 100% by mass of the lubricating oil, the content of the friction modifier is 0.2-0.4%.

[0059] In some embodiments, the static friction coefficient change rate of the lubricating oil friction characteristics test is less than 8%. The lubricating oil friction characteristics test is conducted in accordance with JASO M348 standard "Road Vehicle Automatic Transmission Fluid Friction Characteristics Test Method" for at least 10,000 cycles.

[0060] In some embodiments, the torque variation characteristic parameter of the lubricant during NVH testing is less than 10 N·m. The torque variation characteristic parameter refers to the torque variation of a friction plate coated with the lubricant at a predetermined speed difference during the NVH testing of the lubricant. Specifically, during the NVH testing of the lubricant, the torque variation of the friction plate coated with the lubricant at a speed difference of 20 rpm is less than 5 N·m, and the torque variation at a speed difference of 100 rpm is less than 10 N·m.

[0061] Specifically, the NVH test of the lubricating oil was performed on a low-speed SAE No. 2 friction tester.

[0062] In the dynamic pressure-torque test, the lubricant exhibited a torque variation characteristic parameter of less than 2 N·m during a linear pressure change from 0 to 12 bar. The dynamic pressure-torque test operates within a pressure range of 0-12 bar, with the friction plate speed differential varying from Δ20 r / min to Δ100 r / min. During the test, a speed differential, such as Δ20 r / min, is determined. The pressure is then controlled to increase from 0 bar to 12 bar and then decrease from 12 bar to 0 bar, thereby determining the lubricant's torque variation characteristic parameter under varying pressure and speed differential conditions.

[0063] Specifically, the dynamic pressure-torque test was performed on a ZF dual-motor tribometer.

[0064] The present invention will be further described in detail below in conjunction with preferred embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0065] Examples and Comparative Examples

[0066] Prepare lubricating oil according to the ingredients shown in Table 1.

[0067] The raw materials of finished oil in Comparative Example 1 are as follows:

[0068] Base oil: Choose the three types of base oil commonly used on the market, Yubase produced by South Korea's SK, GTL produced by the Netherlands Shell, or CTL produced by Sinopec, which are universal.

[0069] Viscosity index improver: The finished oil may contain one or more viscosity index improvers, including but not limited to polymethacrylate, vinyl aromatic monomer, polyalphaolefin, polyisobutylene, hydrogenated copolymer of styrene-butadiene, ethylene-propylene copolymer, esterified copolymer of unsaturated carboxylic acid, anhydride or its derivatives.

[0070] Additives: including dispersants, detergents, extreme pressure agents (usually containing boron and / or sulfur and / or phosphorus), anti-wear agents, antioxidants (such as hindered phenols, amine antioxidants or molybdenum compounds), corrosion inhibitors, friction modifiers, rubber swelling agents, and mixtures thereof.

[0071] Antifoaming agent and pour point depressant: The antifoaming agent is a copolymer of ethyl acrylate, 2-ethylhexyl acrylate and optionally vinyl acetate, or polydimethylsiloxane. The pour point depressant is polymethacrylate, polyacrylate or polyacrylamide.

[0072] The preparation method of the friction modifier in the embodiment is:

[0073] At 0° C., the imide compound is added dropwise to a tetrahydrofuran solvent containing sodium cyanide to obtain a mixed solution, and the mixed solution is reacted at 50° C. for 6 hours;

[0074] The halogenated phosphate compound was added dropwise to the mixed solution at 0° C. After the halogenated phosphate compound was added dropwise, the mixture was reacted at 50° C. for 8 hours.

[0075] The solvent and additive were removed by rotary evaporation, and then 200 mL of ether was added and stirred to wash the unreacted monomer components in the product. This was repeated three times. After washing, the ether was removed by rotary evaporation, and then ethyl acetate was used as the eluent. The product was purified by alumina column chromatography to obtain a friction modifier.

[0076] The molar ratio of the imide compound, the sodium cyanide, the halogenated phosphate compound and the auxiliary agent is (2-2.1):(2-2.1):1:(0.05-0.1).

[0077] In Example 1, the halogenated phosphate compound is ethyl dichlorophosphate, and the imide compound is 2-(5-eicosenyl)-succinimide.

[0078] In Example 2, the halogenated phosphate compound is ethyl dichlorophosphate, and the imide compound is 2-pentacosyl-succinimide.

[0079] In Example 3, the halogenated phosphate compound is ethyl dichlorophosphate, and the imide compound is 2-(ethoxyeicosanoate)-succinimide.

[0080] Table 1

[0081]

[0082] Performance Testing

[0083] Test (1) Friction properties test: The lubricating oils of Comparative Example 1 and Examples 1-3 were tested on an SAE No. 2 friction tester according to the JASO M348 standard. The friction plate material was NW461E and the steel plate material was T903. 10,000 cycles were performed for an extended period of time. Dynamic friction coefficient μ d It refers to the friction coefficient when two contacting surfaces have a relative motion speed, representing the shift speed. μ0 refers to the friction coefficient measured at the end of the shift or the final friction coefficient when the friction plate surface speed is relatively low, that is, when the friction plate engagement is completed. It is the maximum dynamic friction coefficient when the speed is less than 200r / min, μ0 / μ d The ratio affects the shift quality. Static friction coefficient μ s It is calculated based on the maximum torque value after the drag starts. It is the measured value when two static contact surfaces just start to slide relative to each other under the action of load, representing the torque capacity. The test results are filled in Table 2. The test diagrams of Example 1 and Comparative Example 1 are shown in Table 2. Figures 1-6 shown.

[0084] Table 2

[0085]

[0086]

[0087] Test (2) NVH test of lubricating oil: The lubricating oils of Comparative Example 1 and Example 1 were tested on a low-speed SAENo.2 friction tester. The friction plate material was BW4329, the steel plate material was SPCC-1B, the constant speed was 20 or 100 r / min, and the oil temperature was 40°C. The results are as follows: Figure 7-10 As shown, the difference in the dithering effect can be clearly seen.

[0088] Test (3) Dynamic pressure-torque test: The lubricating oils of comparative example 1 and embodiment 1 were subjected to dynamic pressure-torque test of friction plates on a ZF dual-motor friction tester. The friction plate material is BW4329, the steel plate material is SPCC-1B, and the oil temperature is 40°C. The speed of one side of the dual motor is 1000r / min, and the speed of the other side is 900r / min in the first test, 950r / min in the second test, and 980r / min in the third test. The process of the pressure rising uniformly from 0bar to 12bar and then falling back to 0bar forms three torque peaks with speed differences of Δ100r / min, Δ50r / min, and Δ20r / min, respectively. The results are as follows Figure 11 and Figure 12 As shown in the figure, the difference in vibration is obvious, which is consistent with the test results of low-speed SAE No.2.

[0089] The test results of Example 2 are similar to those of Example 1, and the test chart and data thereof are not attached herewith.

[0090] Depend on Figures 1-6 As shown in Table 2, the dynamic friction coefficient and static friction coefficient of the lubricating oil with added friction modifier are lower than those of the lubricating oil without added friction modifier, and the change rate of the static friction coefficient of Example 1 is significantly lower than that of Comparative Example 1. Figure 7-10 It can be clearly seen from the torque change in Example 1 that the jitter is significantly improved compared to that of Comparative Example 1. Figure 11 and Figure 12 The test chart further verifies Figure 7-10 The experimental results confirm that adding the friction modifier of the embodiment of the present invention to the lubricating oil can effectively solve the dynamic vibration problem.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A friction modifier, characterized in that: The structure of the friction modifier is shown in Formula I, Among them, R a Including one or more of alkanes, alkenes and their derivatives, R b It includes one or more alkanes, alkenes, and the formula -O-CH2CH2-COR', where -COR' is derived from a C2-C20 fatty acid.

2. The friction modifier according to claim 1, characterized in that The R a One selected from C1-C10 alkanes, C1-C10 alkenes and derivatives thereof.

3. The friction modifier according to claim 1, characterized in that The R b One or more selected from C5-C30 alkanes, C5-C30 alkenes and the formula -O-CH2CH2-COR', wherein -COR' is derived from a C2-20 fatty acid.

4. The friction modifier according to claim 1, characterized in that The number average molecular weight Mn of the friction modifier is 400-1500, and the molecular weight dispersion Mw / Mn of the friction modifier is 1.0-1.

2.

5. The friction modifier according to claim 4, characterized in that The number average molecular weight Mn of the friction modifier is 800-1200, and the molecular weight dispersion Mw / Mn of the friction modifier is 1.0-1.

08.

6. The method for preparing the friction modifier according to claims 1 to 5, characterized in that: The following steps are involved: An imide compound, an alkali metal cyanide, a halogenated phosphate compound, an auxiliary agent and a solvent are mixed and reacted to obtain a crude friction modifier product, and the crude product is purified to obtain a friction modifier as shown in Formula I; the halogenated phosphate compound is shown in Formula II, and the imide compound is shown in Formula III. Among them, R a Including one or more of alkanes, alkenes and their derivatives, R b It includes one or more alkanes, alkenes, and the formula -O-CH2CH2-COR', wherein -COR' is derived from C2-20 fatty acid, and X is selected from one or more of F, Cl, Br, and I.

7. The method for preparing a friction modifier according to claim 6, wherein: At 0-4° C., the imide compound is added dropwise to the solvent containing the metal cyanide to obtain a mixed solution, and the mixed solution is reacted at 40-60° C. for 6-7 hours; The halogenated phosphate compound is added dropwise to the mixed solution at 0-4° C. After the halogenated phosphate compound is added dropwise, the mixture is reacted at 40-60° C. for 7-8 hours.

8. In the method for preparing a friction modifier according to claim 6, the metal cyanide comprises sodium cyanide.

9. The method for preparing a friction modifier according to claim 6, wherein: The molar ratio of the imide compound, the metal cyanide, the halogenated phosphate compound and the auxiliary agent is (2-2.1):(2-2.1):1:(0.05-0.1).

10. The method for preparing a friction modifier according to claim 6, wherein: The auxiliary agent includes a phenolic polymerization inhibitor, and the phenolic polymerization inhibitor includes hydroquinone.

11. The method for preparing a friction modifier according to claim 6, wherein: The solvent includes one or more of tetrahydrofuran, diethyl ether and dioxane.

12. A lubricating oil, characterized in that: The friction modifier comprises the friction modifier according to any one of claims 1 to 5 or the friction modifier prepared by the preparation method of the friction modifier according to any one of claims 6 to 11.

13. The lubricating oil according to claim 12, characterized in that The static friction coefficient change rate of the lubricating oil in the friction characteristic test is less than 7%.

14. The lubricating oil according to claim 12, characterized in that The torque variation characteristic parameter of the NVH test of the lubricating oil is less than 10 N·m.

15. The lubricating oil according to claim 12, characterized in that In a dynamic pressure-torque test, the torque variation characteristic parameter of the lubricating oil during a linear pressure change of 0-12 bar is less than 2 N·m.

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