Long-life electric drive system reduction gearbox oil composition and preparation method thereof

Abstract

The invention relates to the technical field of gear oil, in particular to a long-life electric drive system reduction gearbox oil composition and a preparation method thereof. The composition comprises the following components in parts by weight: (A) 84.0-99.2 parts of at least one oxygen-containing synthetic hydrocarbon base liquid; (B) 0.2-5.0 parts of at least one extreme pressure additive; (C) 0.1-2.0 parts of at least one anti-wear additive; (D) 0.1-1.0 part of at least one friction improving additive; (E) 0.2-3.0 parts of at least one antioxidant additive; (F) 0.2-5.0 parts of at least one cleaning and dispersing additive. The reduction gearbox oil composition disclosed by the invention has excellent copper-containing material protection performance, heat conduction performance, insulating performance, extreme pressure anti-wear performance, friction improvement performance and thermal oxidation stability; and the cooling requirements of motors and electronic devices of new energy automobiles and the lubricating requirements of reduction gearboxes and differential mechanisms at present and in future can be met.

Description

Technical Field

[0001] This invention relates to the field of gear oil technology, specifically to a long-life electric drive system gearbox oil composition and its preparation method. Background Technology

[0002] The electric drive system of a new energy vehicle consists of four parts: a motor, electronic components, a gearbox, and a differential. The motor and electronic components share a cooling system; the coolant's main functions are heat transfer, cooling, insulation, and effective protection of copper materials. The gearbox reduces the motor's high speed to a suitable output speed, using single-stage or 2-3-stage reduction, requiring the lubricant to provide lubrication and protection for core components such as gears, bearings, synchronizers, and clutches. The differential ensures the independent speed of each wheel, requiring the lubricant to have excellent frictional characteristics. The gearbox and differential share a lubrication system; the lubricant needs to possess suitable extreme pressure anti-wear properties, synchronization performance, frictional characteristics, and coefficient of friction.

[0003] While pure electric vehicles will no longer use engine oil, the lubricants used in the reducer and differential, as well as the coolants used in the motor and electronic components, will become indispensable core fluid components. Due to the incompatibility of lubrication and cooling technologies, most electric vehicles currently employ two independent systems. This hinders the integration, control, unification, lightweight design, and intelligence of electric vehicles, restricting overall cost reduction and efficiency improvement, and severely impeding their rapid development. Combining the reducer, differential lubricant, and motor / electronic component coolant into a single integrated system allows for a compact, integrated design, achieving safety, energy efficiency, and a longer lifespan – representing the ultimate trend in future electric vehicle development.

[0004] This trend poses a severe challenge to gearbox oil technology. The specific challenges are mainly reflected in the following three aspects: (1) The contradiction between lubrication and cooling. The principle of lubrication is that the lubricating oil forms a physical or chemical adsorption film on the surface of the friction pair, preventing direct contact between the friction pairs, thereby playing a protective role for the lubricating oil. Generally, hydrocarbon components are used as the base fluid for lubrication. The principle of cooling is to achieve rapid cooling by heat exchange between the coolant and the material being cooled. Generally, water, alcohol, etc. are used as the base fluid. The mechanisms of lubrication and cooling are different, and the base fluids and functional additives used are also completely different. Achieving compatibility between lubrication and cooling is an international technical problem and a bottleneck problem for the development of electric vehicles; (2) The contradiction between extreme pressure and corrosion. The high speed of the motor and the high torque of the reducer and differential put forward higher requirements for the extreme pressure performance of the lubricating fluid. It is necessary to add sulfur-containing extreme pressure additives to the lubricating fluid. However, the corrosion of copper materials in the motor coil by sulfur-containing additives is fatal. Solving the contradiction between extreme pressure and corrosion is the top priority of electric vehicle lubrication and cooling technology. A new technology is urgently needed to solve this key problem; (3) The contradiction between wear resistance and insulation. Anti-wear properties of gears and bearings are achieved by introducing phosphorus-containing anti-wear agents into the base lubricant. These phosphorus-containing anti-wear additives, due to their unique polarity, form a physical and chemical adsorption film on the surface of the friction pair, thus exerting an anti-wear effect. However, the polarity of phosphorus-containing anti-wear agents can adversely affect the insulation performance of the gearbox oil, and may even cause insulation failure, leading to safety issues. Resolving the contradiction between anti-wear and insulation is an inevitable trend and imperative for the future development of lubrication and cooling technology for electric vehicles.

[0005] Current lubrication and cooling technologies do not simultaneously address and resolve the three major contradictions and problems mentioned above. For example, Chinese invention patent application CN110643415A discloses an open gear oil composition containing 20 to 80 parts by weight of one or more mixtures selected from reduced-pressure four-line oil, 150BS, or 680 coarse feedstock; 10 to 50 parts by weight of recycled bottom oil; 5 to 50 parts by weight of asphalt; 0.1 to 1 part by weight of sulfur-containing extreme pressure additive; 0.1 to 1 part by weight of phosphorus-containing anti-wear additive; 0.1 to 1 part by weight of antioxidant additive; 0.1 to 1 part by weight of metal detergent; and 0.1 to 1 part by weight of friction modifier. This invention does not focus on the performance of gear oil in terms of lubrication, cooling, extreme pressure, anti-wear, and insulation.

[0006] Chinese invention patent application CN103509637A discloses an automotive automatic transmission fluid composition with excellent anti-wear properties, comprising (A) at least one high viscosity index hydrorefined Group III mineral oil, or synthetic oil, or any combination of the above components; (B) at least one viscosity index improver; (C) at least one pour point depressant; (D) at least one phosphorus-containing anti-wear additive; (E) at least one metal detergent; (F) at least one ashless dispersant; (G) at least one high-temperature antioxidant; (H) at least one friction modifier; and (I) at least one metal passivator. The above lubricating oil composition exhibits excellent high and low temperature performance, anti-wear properties, friction characteristics, anti-wear and friction durability, and thermal oxidation stability, but it does not address cooling, extreme pressure, and insulation properties.

[0007] Therefore, it is essential to develop a long-life gearbox oil composition for electric drive systems that can solve the above-mentioned technical problems and its preparation method. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a long-life electric drive system gearbox oil composition and its preparation method. It has excellent copper-containing material protection properties, thermal conductivity, insulation properties, extreme pressure anti-wear properties, friction improvement properties and thermal oxidation stability. It can meet the cooling and lubrication needs of motors and electronic devices in current and future new energy vehicles, as well as gearboxes and differentials. It is a general-purpose electric drive system gearbox oil.

[0009] To achieve the above objectives, this invention optimizes the selection of the base fluid and various additive components in the gearbox oil composition. It also conducts a comprehensive and systematic study of the various base fluids, functional additives, and interactions between them. The study focuses on the thermal conductivity, copper protection, extreme pressure performance, and insulation properties of the gearbox oil composition. The aim is to ensure that the gearbox oil composition of this invention can simultaneously meet the cooling requirements of current and future new energy vehicle motors and electronic components, as well as the lubrication needs of gearboxes and differentials, achieving universal lubrication and cooling, improving battery and motor efficiency, and extending the lifespan of the transmission system.

[0010] This invention is achieved through the following technical solutions:

[0011] A long-life electric drive system gearbox oil composition, comprising the following components by weight:

[0012] (A) At least one oxygen-containing synthetic hydrocarbon base liquid, 84.00-99.20 parts;

[0013] (B) At least one extreme pressure additive, 0.2-5.0 parts;

[0014] (C) At least one anti-wear additive, 0.1-2.0 parts;

[0015] (D) 0.1-1.0 parts of at least one friction-modifying additive;

[0016] (E) At least one antioxidant additive, 0.2-3.0 parts;

[0017] (F) At least one cleaning and dispersing additive, 0.2-5.0 parts.

[0018] Preferably, the composition comprises the following components in parts by weight:

[0019] (A) 84.0-96.2 parts of at least one oxygen-containing synthetic hydrocarbon base solution;

[0020] (B) At least one extreme pressure additive, 0.2-5.0 parts;

[0021] (C) At least one anti-wear additive, 0.3-2.0 parts;

[0022] (D) 0.3-1.0 parts of at least one friction-modifying additive;

[0023] (E) At least one antioxidant additive, 1.0-3.0 parts;

[0024] (F) At least 2.0-5.0 parts of at least one cleaning and dispersing additive.

[0025] Preferably, the oxygen content of the synthetic hydrocarbon base liquid is 25.0-40.0 wt%.

[0026] Preferably, the extreme pressure additive comprises a multifunctional nano-copper additive modified with dimercaptothiadiazole, wherein the copper content is 0.001-20.0 wt%.

[0027] Preferably, the anti-wear additive comprises a non-polar phosphine-containing compound. The non-polar phosphine-containing compound contains an alkyl group.

[0028] The non-polar phosphine-containing compound of the present invention has a different P-containing structure from that in traditional isooctyl phosphate amine salt anti-wear additives. The former has CP linkage, while the latter has COP linkage. The non-polar phosphine-containing compound of the present invention has superior insulation and anti-wear properties, thus resolving the contradiction between anti-wear and insulation properties of gearbox oil.

[0029] More preferably, the alkyl group in the nonpolar phosphine compound has 3-18 carbon atoms.

[0030] Preferably, the friction-improving additive includes at least one of long-chain amines, long-chain alcohols, and long-chain esters.

[0031] More preferably, the alkyl group in the friction-improving additive has 8-24 carbon atoms.

[0032] Preferably, the antioxidant additive includes at least one of dialkyl diphenylamine and alkyl 2,6-di-tert-butylphenol acrylate.

[0033] Preferably, the alkyl group in the antioxidant additive has 4-12 carbon atoms.

[0034] Preferably, the cleaning and dispersing additive includes at least one of polyisobutylene succinimide and alkyl salicylate.

[0035] More preferably, the polyisobutylene molecular weight of the polyisobutylene succinimide is 800-2500.

[0036] More preferably, the alkyl group in the alkyl salicylic acid alkyl ester has 4-18 carbon atoms.

[0037] The present invention also relates to a method for preparing the above-mentioned composition, comprising the following steps:

[0038] Mix all components and stir until the mixture is uniform and transparent.

[0039] Preferably, the mixing temperature is 40-50°C.

[0040] Preferably, the stirring time is 1.5-2.5 hours.

[0041] The purpose of this invention is to solve the key core technology problems of lubrication protection and effective cooling of electric drive systems in new energy vehicles by discovering a brand-new lubrication and cooling mechanism, scientifically and rationally compounding various functional components, and combining lubricating oil and coolant into one, so as to improve the efficiency of batteries and motors and extend the life of transmission systems, and realize the safe, convenient, fast, green and healthy development of new energy vehicles.

[0042] The beneficial effects of this invention are:

[0043] The gearbox oil composition of this invention possesses excellent protective properties for copper-containing materials, thermal conductivity, insulation properties, extreme pressure anti-wear properties, friction-improving properties, and thermal oxidation stability. By selecting a high-oxygen synthetic hydrocarbon base fluid, the gearbox oil composition not only exhibits excellent thermal conductivity but also good lubrication properties, resolving the contradiction between lubrication and cooling. The selection of a dimercaptothiadiazole-modified nano-copper extreme pressure multifunctional additive resolves the contradiction between extreme pressure and corrosion. The selection of a non-polar phosphine-containing anti-wear additive resolves the contradiction between anti-wear and insulation. Compared with currently available electric vehicle lubricants, it exhibits no corrosion to copper materials, a 15% increase in thermal conductivity, double the extreme pressure performance, a 50% increase in anti-wear performance, and a 94% increase in volume resistivity, fully meeting the special requirements of future new energy vehicle electric drive systems for new lubrication and cooling materials. Detailed Implementation

[0044] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solutions of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0045] To screen the base fluid components, functional additive components, and gearbox oil composition, this invention employed various testing methods for analysis and evaluation. These included copper strip corrosion test (ASTM D130), oxidation stability test (CEC L-48-A-00), FZG extreme pressure test FZG A10 / 16.6R / 90 (CEC L-84-02), FE-8 bearing pitting test (VW PV1483) (300 r / min, 68 KN, 100℃), FE-8 bearing wear test (DIN51819-3) (7.5 r / min, 80 KN, 80℃, 80 h), gear pitting test (FZG FVA#2 / Ⅳ) (1450 r / min, 372.6 KN, 100℃), high-energy start-up test (BW C4), thermal conductivity (ASTM D7896), and specific heat capacity (ASTM D7896). E1269), insulation voltage (GB / T507), volume resistivity (GB / T5654), synchronizer durability test (SSP-180 carbon fiber, sintered copper, molybdenum spray), friction characteristic test (JASO M348), etc.

[0046] The copper dimercaptothiadiazole salts used in the following examples were purchased from Taiyuan Anrun Petroleum Additives Co., Ltd., product number AR5389.

[0047] Component C in each embodiment (including tri-octadecyl phosphine-containing anti-wear additive, n-butyl phosphine-containing anti-wear additive, isooctyl phosphine-containing anti-wear additive, and dodecyl phosphine-containing anti-wear additive) was purchased from Taiyuan Anrun Petroleum Additives Co., Ltd.

[0048] POE6 indicates that the viscosity grade of POE is 6.

[0049] Example 1

[0050] The gearbox oil composition (I) comprises: 84.00 wt% of a high-oxygen (40.0 wt%) synthetic hydrocarbon base fluid ethylene oxide polymer (component A); 5.00 wt% of a dimercaptothiadiazole-modified nano-copper multifunctional additive dimercaptothiadiazole copper salt (20.0 wt% copper content) (component B); 2.00 wt% of a tri-octadecylphosphine-containing anti-wear additive (component C, catalog number AR5390); 0.10 wt% di-dodecylamine, 0.10 wt% dodecyl alcohol, and 0.80 wt% n-octyl oleate (component D); 1.00 wt% butyryldiphenylamine and 2.00 wt% n-butyl 2,6-di-tert-butylphenol acrylate (component E); 4.50 wt% polyisobutylene succinimide (polyisobutylene molecular weight 2500) and 0.50 wt% octadecyl salicylate (component F).

[0051] Gearbox oil composition (II) comprises: 84.00 wt% hydrogenated polyolefin synthetic base fluid PAO6 (Mobil) (component A); 5.00 wt% dimercaptothiadiazole modified nano-copper multifunctional additive dimercaptothiadiazole copper salt (copper content 20.0 wt%) (component B); 2.00 wt% tri-octadecylphosphine-containing anti-wear additive (component C); 0.10 wt% di-dodecylamine, 0.10 wt% dodecyl alcohol, 0.80 wt% n-octyl oleate (component D); 1.00 wt% butyryldiphenylamine, 2.00 wt% n-butyl 2,6-di-tert-butylphenol acrylate (component E); 4.50 wt% polyisobutylene succinimide (polyisobutylene molecular weight 2500), 0.50 wt% octadecyl salicylate (component F).

[0052] Gearbox oil composition (III) comprises: 84.00 wt% polyol ester synthesis base fluid POE6 (component A); 5.00 wt% dimercaptothiadiazole modified nano-copper multifunctional additive dimercaptothiadiazole copper salt (copper content 20.0 wt%) (component B); 2.00 wt% tri-octadecylphosphine-containing anti-wear additive (component C); 0.10 wt% di-dodecylamine, 0.10 wt% dodecyl alcohol, 0.80 wt% n-octyl oleate (component D); 1.00 wt% butyryldiphenylamine, 2.00 wt% 2,6-di-tert-butylphenol acrylate n-butyl ester (component E); 4.50 wt% polyisobutylene succinimide (polyisobutylene molecular weight 2500), 0.50 wt% octadecyl salicylate (component F).

[0053] Table 1 Comparison of thermal conductivity of compositions (I), (II), and (III)

[0054]

[0055] Experimental results show that the high oxygen content synthetic hydrocarbon base liquid of the present invention has superior heat transfer and cooling performance compared with hydrogenated polyolefin synthetic base liquid PAO and polyol ester synthetic base liquid POE.

[0056] Example 2:

[0057] Gearbox oil composition (Ⅳ) comprises: 95.95 wt% high oxygen content (25.0 wt%) synthetic hydrocarbon base fluid ethylene oxide polymer (component A); 0.45 wt% dimercaptothiadiazole modified nano-copper multifunctional additive dimercaptothiadiazole copper salt (copper content 0.001 wt%) (component B); 0.30 wt% n-butyl phosphine-containing anti-wear additive (component C); 0.05 wt% di-n-octylamine, 0.05 wt% tetradecyl alcohol, 0.20 wt% dodecyl stearate (component D); 0.50 wt% dioctyl diphenylamine, 0.50 wt% 2,6-di-tert-butylphenol acrylate n-octyl ester (component E); 2.00 wt% polyisobutylene succinimide (polyisobutylene molecular weight 1000) (component F).

[0058] The gearbox oil composition (V) comprises: 95.95 wt% of a high-oxygen (25.0 wt%) synthetic hydrocarbon base fluid ethylene oxide polymer (component A); 0.45 wt% of diisooctyl trisulfide (component B); 0.30 wt% of a n-butyl phosphine-containing anti-wear additive (component C); 0.05 wt% di-n-octylamine, 0.05 wt% tetradecyl alcohol, and 0.20 wt% dodecyl stearate (component D); 0.50 wt% dioctyl diphenylamine and 0.50 wt% 2,6-di-tert-butylphenol acrylate (component E); and 2.00 wt% polyisobutylene succinimide (polyisobutylene molecular weight 1000) (component F).

[0059] Table 2 Comparison of extreme pressure corrosion performance of compositions (Ⅳ)(Ⅴ)

[0060]

[0061] The experimental results show that, compared with traditional sulfur-containing dialkyl trisulfides, the dimercaptothiadiazole-modified nano-copper multifunctional extreme pressure additive of the present invention not only has more outstanding extreme pressure performance, but also can reduce the copper content in the oil after the enhanced copper corrosion test and keep the copper sheets clean and new. It has excellent anti-corrosion performance and completely solves the natural contradiction between extreme pressure and corrosion of gearbox oil.

[0062] Example 3:

[0063] The gearbox oil composition (VI) comprises: 90.90 wt% of a high-oxygen (34.0 wt%) synthetic hydrocarbon base fluid ethylene oxide polymer (component A); 0.20 wt% of a dimercaptothiadiazole modified nano-copper multifunctional additive dimercaptothiadiazole copper salt (copper content 0.20 wt%) (component B); 2.00 wt% of an isooctyl phosphine-containing anti-wear additive (component C); 0.10 wt% of C11-14 tert-alkyl primary amine, 0.10 wt% octadecyl alcohol, and 0.50 wt% isooctyl oleate (component D); 0.80 wt% dinonyldiphenylamine and 0.40 wt% 2,6-di-tert-butylphenol acrylate (component E); 4.50 wt% polyisobutylene succinimide (polyisobutylene molecular weight 800) and 0.50 wt% octadecyl salicylate (component F).

[0064] The gearbox oil composition (VII) comprises: 90.90 wt% of a high-oxygen (34.0 wt%) synthetic hydrocarbon base fluid ethylene oxide polymer (component A); 0.20 wt% of a dimercaptothiadiazole-modified nano-copper multifunctional additive dimercaptothiadiazole copper salt (copper content 0.20 wt%) (component B); 2.00 wt% of isooctyl phosphate amine salt anti-wear additive (component C); 0.10 wt% of C11-14 tert-alkyl primary amine, 0.10 wt% octadecyl alcohol, and 0.50 wt% isooctyl oleate (component D); 0.80 wt% dinonyldiphenylamine and 0.40 wt% 2,6-di-tert-butylphenol acrylate (component E); 4.50 wt% polyisobutylene succinimide (polyisobutylene molecular weight 800) and 0.50 wt% octadecyl salicylate (component F).

[0065] Table 3 Comparison of wear resistance and insulation properties of compositions (VI) and (VII)

[0066]

[0067] The test results show that the isooctyl phosphine-containing anti-wear additive of the present invention has superior insulation and anti-wear properties compared with the traditional isooctyl phosphate amine salt anti-wear additive, thus resolving the contradiction between anti-wear and insulation properties of gearbox oil.

[0068] Example 4:

[0069] The gearbox oil composition (VIII) comprises: 91.00 wt% of a high-oxygen (38.0 wt%) synthetic hydrocarbon base fluid ethylene oxide polymer (component A); 0.45 wt% of a dimercaptothiadiazole-modified nano-copper multifunctional additive dimercaptothiadiazole copper salt (copper content 0.001 wt%) (component B); 0.55 wt% of a dodecyl phosphorus-containing anti-wear additive (component C); 0.20 wt% di-n-octylamine, 0.20 wt% dodecyl alcohol, and 0.60 wt% n-octyl oleate (component D); 0.80 wt% butyryldiphenylamine and 1.20 wt% n-octyl 2,6-di-tert-butylphenol acrylate (component E); 4.50 wt% polyisobutylene succinimide (polyisobutylene molecular weight 2500) and 0.50 wt% octadecyl salicylate (component F). The reference fluid in Table 4 is a commercially available gearbox oil for electric drive systems.

[0070] Table 4 Performance evaluation results of composition (VIII)

[0071]

[0072]

[0073] Test results show that the gearbox oil composition of this invention possesses excellent copper-containing material protection properties, thermal conductivity, insulation properties, extreme pressure anti-wear properties, friction improvement properties, and thermal oxidation stability. This invention resolves the contradiction between lubrication and cooling through a high-oxygen synthetic hydrocarbon base fluid; resolves the contradiction between extreme pressure and corrosion through a multifunctional nano-copper additive modified with dimercaptothiadiazole; and resolves the contradiction between anti-wear and insulation through a non-polar phosphine-containing anti-wear additive. Compared with traditional electric vehicle gearbox oils, it provides no corrosion to copper materials, increases thermal conductivity by 15%, doubles extreme pressure performance, improves anti-wear performance by 50%, and increases volume resistivity by 94%. It fully meets the cooling requirements of motors and electronic components in current and future new energy vehicles, as well as the lubrication needs of gearboxes and differentials, achieving universal lubrication and cooling, and significantly improving battery and motor efficiency and extending the lifespan of the transmission system.

[0074] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A long life electric drive system reduction gearbox oil composition characterized in that, By weight parts, comprising the following components: (A) at least one oxygen-containing synthetic hydrocarbon base fluid 84.0-99.2 parts; (B) at least one extreme pressure additive 0.2-5.0 parts; (C) at least one anti-wear additive 0.1-2.0 parts; (D) at least one friction modifier additive 0.1-1.0 parts; (E) at least one antioxidant additive 0.2-3.0 parts; (F) at least one detergent dispersant additive 0.2-5.0 parts.

2. The composition of claim 1, wherein, The oxygen content of the synthetic hydrocarbon base fluid is 25.0-40.0 wt%.

3. The composition of claim 1, wherein, The extreme pressure additive comprises a dithiozole-modified nano-copper multifunctional additive, wherein the copper content is 0.001-20.0 wt%.

4. The composition of claim 1, wherein, The anti-wear additive comprises a non-polar phosphine-containing compound.

5. The composition of claim 4, wherein, The number of carbon atoms of the alkyl group in the non-polar phosphine-containing compound is 3-18.

6. The composition of claim 1, wherein, The friction modifier additive comprises at least one of a long-chain amine, a long-chain alcohol, and a long-chain ester.

7. The composition of claim 6, wherein, The number of carbon atoms of the alkyl group in the friction modifier additive is 8-24.

8. The composition of claim 1, wherein, The antioxidant additive comprises at least one of a dialkyldiphenylamine and a 2,6-di-tert-butyl phenyl acrylate.

9. The composition of claim 8, wherein, The number of carbon atoms of the alkyl group in the antioxidant additive is 4-12.

10. The composition of claim 1, wherein, The detergent dispersant additive comprises at least one of a polyisobutenyl succinimide and an alkyl alkylsalicylate.

11. The composition of claim 10, wherein, The polyisobutenyl succinimide has a polyisobutenyl molecular weight of 800-2500.

12. The composition of claim 10, wherein, The number of carbon atoms of the alkyl group in the alkyl alkylsalicylate is 4-18.

13. The composition of claim 1, wherein, By weight parts, comprising the following components: (A) at least one oxygen-containing synthetic hydrocarbon base fluid 84.0-96.2 parts; (B) at least one extreme pressure additive 0.2-5.0 parts; (C) at least one anti-wear additive 0.3-2.0 parts; (D) at least one friction modifier additive 0.3-1.0 parts; (E) at least one antioxidant additive 1.0-3.0 parts; (F) at least one detergent dispersant additive 2.0-5.0 parts.

14. Process for the preparation of a composition according to any one of claims 1 to 13, characterized in that, Comprising the following steps: Mixing the components, stirring until the mixture is uniform and transparent, and obtaining.

15. The preparation method according to claim 14, characterized in that, The temperature of the mixing is 40-50℃.

16. The method of claim 14, wherein, The time of the stirring is 1.5-2.5h.

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