Hydrogen fuel engine lubricating oil composition and preparation method thereof

Abstract

The invention provides a hydrogen fuel engine lubricating oil composition and a preparation method thereof. The lubricating oil composition for the hydrogen fuel engine comprises the following components: (A) phosphate ester and / or phosphate ester amine salt; (B) alkylated diphenylamine; (C) a polyisobutylene succinimide ashless dispersant and / or a polyisobutylene succinic acid pentaerythritol ester dispersant; (D) magnesium salicylate and / or calcium sulfonate; (E) zinc dialkyl dithiophosphate; (F) a thio phenolic ester type antioxidant; (G) a metal corrosion inhibitor; (H) a demulsifying agent; (I) a major amount of a lubricating base oil; wherein the structure of the phosphate ester and / or the phosphate ester amine salt is shown as a formula (X), and the definition of each group is shown in the specification. The lubricating oil composition for the hydrogen fuel engine has excellent high-temperature oxidation resistance, cleaning performance, anti-wear and anti-friction performance and anti-corrosion performance, and generation of high-temperature sediments can be remarkably reduced.

Description

Technical Field

[0001] This invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition for a hydrogen fuel engine and a method for preparing the same. Background Art

[0002] Hydrogen, as a clean fuel, possesses characteristics such as low carbon emissions, environmental friendliness, and lower cost after large-scale production, gaining increasing attention internationally and driving the development of hydrogen-powered internal combustion engine vehicles. Its technological development has become a research hotspot. During the research and development of hydrogen fuel cell engines, major automakers have discovered problems such as engine oil emulsification, sludge buildup, and shortened oil change intervals when using traditional gasoline engine oils. Simultaneously, the engines are prone to premature wear and piston scoring. During operation, hydrogen fuel cell engines experience high combustion chamber and exhaust temperatures, requiring the engine lubricant to have strong high-temperature oxidation resistance. Furthermore, the water vapor produced during combustion enters the engine oil, causing emulsification and deterioration, easily forming hard deposits on engine component surfaces, leading to increased carbon buildup and accelerated wear. Therefore, hydrogen fuel cell engine lubricants with anti-wear, anti-oxidation, anti-emulsification properties and low ash content represent the future development trend. Summary of the Invention

[0003] This invention proposes a lubricating oil composition for a hydrogen fuel engine and its preparation method.

[0004] The hydrogen fuel engine lubricating oil composition of the present invention comprises the following components:

[0005] (A) Phosphate esters and / or phosphate ester amine salts, comprising 0.1% to 15% (preferably 0.5% to 10%) of the total mass of the composition;

[0006] (B) Alkylated diphenylamine, comprising 0.1% to 10% (preferably 0.5% to 5%) of the total mass of the composition;

[0007] (C) Polyisobutylene succinimide ashless dispersant and / or polyisobutylene succinate pentaerythritol dispersant, accounting for 3% to 15% (preferably 5% to 10%) of the total mass of the composition;

[0008] (D) Magnesium salicylate and / or calcium sulfonate, comprising 0.2% to 10% (preferably 0.5% to 8%) of the total mass of the composition;

[0009] (E) Zinc dialkyl dithiophosphate, comprising 0.1% to 5% (preferably 0.2% to 3%) of the total mass of the composition;

[0010] (F) Thiophenol ester type antioxidant, accounting for 0.02% to 10% (preferably 0.1% to 4%) of the total mass of the composition;

[0011] (G) Metal corrosion inhibitor, comprising 0.01% to 3% (preferably 0.02% to 1%) of the total mass of the composition;

[0012] (H) Demulsifier, comprising 0.02% to 5% (preferably 0.1% to 3%) of the total mass of the composition;

[0013] (I) Main component of lubricating base oil;

[0014] The structure of the phosphate ester and / or phosphate ester amine salt is shown in formula (X):

[0015]

[0016] In formula (X), each R1 group is independently selected from H, C1 to C1. 30 Straight-chain or branched alkyl groups, C3-C 30 cycloalkyl, C7-C 30 alkylphenyl, C7-C 30 The alkoxyphenyl group, R2 group is selected from C8 to C9. 30 The linear or branched alkyl group, n is any number between 0 and 4.4; the formula (X) contains m R1 groups, each independently selected from C1 to C2. 30 Straight-chain or branched alkyl groups, C3-C 30 cycloalkyl, C7-C 30 alkylphenyl, C7-C 30 The alkoxyphenyl group, where m is any number between 1 and 4.

[0017] According to the present invention, n can be any number between 1 and 4, for example, any number between 1 and 2, any number between 2 and 3, or any number between 3 and 4.

[0018] According to the present invention, m can be any number between 1 and 4, for example, it can be 1, 1.5, 2, 2.5, 3, 3.5, 4, or it can be any number between 1 and 2, any number between 2 and 3, or any number between 3 and 4.

[0019] According to the present invention, C7 to C 30 The alkylphenyl group may be selected from the following groups: 4-eicosylphenyl, 4-nonadecanylphenyl, 4-octadecylphenyl, 4-heptadecylphenyl, 4-hexadecylphenyl, 4-pentadecanylphenyl, 4-tetradecylphenyl, 4-tridecylphenyl, 4-dodecylphenyl, 4-undecylphenyl, 4-decylphenyl, 4-decylphenyl, 4-nonylphenyl, 4-octylphenyl, 4-heptylphenyl, 4-hexylphenyl, 4-pentylphenyl, 4-butylphenyl, 4-propylphenyl, 4-ethylphenyl, 4-methylphenyl, 4-sec-octylphenyl; wherein C7~C 30The alkoxyphenyl group can be selected from the following groups: 4-eicosyloxyphenyl, 4-nonadecanoxyphenyl, 4-octadecyloxyphenyl, 4-heptadecyloxyphenyl, 4-pentadecanoxyphenyl, 4-tetradecyloxyphenyl, 4-tridecyloxyphenyl, 4-dodecyloxyphenyl, 4-undecyloxyphenyl, 4-decyloxyphenyl, 4-nonoxyphenyl, 4-octyloxyphenyl, 4-heptyloxyphenyl, 4-hexyloxyphenyl, 4-pentoxyphenyl, 4-butoxyphenyl, 4-propoxyphenyl, 4-ethoxyphenyl, 4-methoxyphenyl.

[0020] According to the present invention, the R2 group may be selected from tert-butyl, tert-hexyl, 1,1,3,3-tetramethylbutyl, 2-decyltetradecyl, preferably 1,1,3,3-4-methylbutyl or 2-decyltetradecyl.

[0021] According to the present invention, the phosphate ester and / or phosphate ester amine salt may be any group of compounds from group (a), group (b), group (c), and group (d) or a combination thereof in any proportion:

[0022] (a) (b)

[0023] (c) (d)

[0024] The method for preparing phosphate esters and / or phosphate ester amine salts according to the present invention includes the following steps (1) and optional steps (2):

[0025] (1) An esterification reaction is carried out between methylene diphosphate and R1OH, and the esterification product is collected; wherein the R1 group is selected from C1 to C1. 30 Straight-chain or branched alkyl groups, C3-C 30 cycloalkyl, C7-C 30 alkylphenyl, C7-C 30 Alkoxyphenyl;

[0026] (2) The esterification product from step (1) is subjected to an amination reaction with H2N-R2, and the product is collected; wherein the R2 group is selected from C8 to C6. 30 Straight-chain or branched alkyl groups.

[0027] According to the present invention, an example reaction formula for the preparation method of the phosphate ester and / or phosphate ester amine salt is shown below:

[0028]

[0029] According to the preparation method of the present invention, optionally, in step (1), the molar ratio between methylene diphosphate and R1OH is 1:1.1 to 4.1; the temperature at which methylene diphosphate and R1OH undergo esterification reaction is -30℃ to 50℃; and the time for which methylene diphosphate and R1OH undergo esterification reaction is 2 to 24 h.

[0030] According to the preparation method of the present invention, optionally, in step (1), a catalyst may be added to the esterification reaction of methylene diphosphonic acid and R1OH. The catalyst may be one or more of concentrated sulfuric acid, p-toluenesulfonic acid, pyridine, methylpyridine, 4-dimethylaminopyridine, triethylamine, diisopropylethylamine, dicyclohexylcarbodiimide, diisopropylcarbodiimide, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide. The molar ratio of each catalyst to methylene diphosphonic acid may be 1:0.15 to 4.1.

[0031] According to the preparation method of the present invention, optionally, in step (2), the molar ratio between the esterification product and H2N-R2 in step (1) is 1:0 to 4.1, for example, it can be 1:1 to 4.1, 1:0 to 1, 1:1 to 2, 1:2 to 3, or 1:3 to 4; the temperature at which the esterification product and H2N-R2 undergo amination reaction in step (1) is 40 to 120°C; the time for the amination reaction between the esterification product and H2N-R2 in step (1) is generally better the longer it is, generally 0.5 to 20 h; the pressure at which the esterification product and H2N-R2 undergo amination reaction in step (1) can be low pressure, normal pressure, or high pressure, without any particular limitation.

[0032] According to the preparation method of the present invention, preferably, in step (2), the esterification product of step (1) reacts with H2N-R2 at 40-90°C for 1-6 hours (preferably at 40-80°C for 2-4 hours), and then at 90-120°C for 1-6 hours (preferably at 90-100°C for 2-4 hours).

[0033] According to the preparation method of the present invention, optionally, a solvent is added to the reaction in step (1). The solvent can be an aprotic nonpolar solvent or a polar solvent, such as one or more of hexane, cyclohexane, petroleum ether, dichloromethane, 1,4-dioxane, N,N'-dimethylformamide, and tetrahydrofuran. The amount of solvent added is preferably sufficient to promote the smooth progress of the reaction and is not particularly limited. For example, the ratio between the weight of the solvent and the total weight of the methylene diphosphate and R1OH can be 10 to 20:1. The solvent can be removed after the reaction is completed by conventional methods in the art, such as distillation or rectification.

[0034] According to the preparation method of the present invention, optionally, a solvent is added to the reaction in step (2). The solvent is preferably a hydrocarbon solvent, more preferably an aromatic solvent, such as one or more of toluene, xylene, petroleum ether, n-hexane, and cyclohexane. The amount of solvent added is suitable for promoting the smooth progress of the reaction and is not particularly limited. For example, the ratio between the weight of the solvent and the total weight of the esterification product and H2N-R2 in step (1) can be 0.5 to 10:1. The solvent can be removed after the reaction is complete by conventional methods in the art, such as distillation or rectification.

[0035] According to the preparation method of the present invention, optionally, the R1OH can be selected from C1 to C2. 30 fatty alcohols, C7-C 30 Aromatic alcohols, C7-C 30 Alkoxy aromatic alcohols, for example, can be selected from ethanol, n-butanol, hexanol, isooctanol, nonanol, dodecanol, 1-octanol, 1-decanol, 1-tetradecylol, 1-hexadecylol, 1-octadecanol, oleyl alcohol, linolenic acid, phytol, triacontylol, lauryl alcohol, myristyl alcohol, stearyl alcohol, behenyl alcohol, 4-eicosylphenol, 4-nonadecanol, 4-octadecylphenol, 4-heptadecylphenol, 4-pentadecanol, 4-tetradecylphenol, 4-tridecylphenol, 4-dodecylphenol, 4-undecylphenol, 4-decylphenol, 4-decylphenol, 4-nonylphenol, 4-octylphenol, 4-heptylphenol, 4-hexylphenol, 4-pentylphenol. The following are some of the following: phenol, 4-butylphenol, 4-propylphenol, 4-ethylphenol, 4-methylphenol, 4-sec-octylphenol, 4-eicosyloxyphenol, 4-nonadecanoxyphenol, 4-octadecyloxyphenol, 4-heptadecyloxyphenol, 4-pentadecanoxyphenol, 4-tetradecyloxyphenol, 4-tridecyloxyphenol, 4-dodecyloxyphenol, 4-undecyloxyphenol, 4-decyloxyphenol, 4-nonoxyphenol, 4-octyloxyphenol, 4-heptyloxyphenol, 4-hexyloxyphenol, 4-pentoxyphenol, 4-butoxyphenol, 4-propoxyphenol, 4-ethoxyphenol, and 4-methoxyphenol.

[0036] Optionally, according to the preparation method of the present invention, the H2N-R2 can be selected from C8 to C9. 30 The straight-chain or branched alkylamines may be selected from one or more of the following: n-octylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine, n-eicosylamine, n-docosahexadecylamine, n-triadecylamine, n-triadecylamine, 1,1,3,3-tetramethylbutylamine, 1,1,3,3,5,5-hexamethylhexylamine, 1,1,3,3,5,5,7,7,9,9-decamethyldecylamine, and 2-decyltetradecylamine.

[0037] According to the preparation method of the present invention, preferably, the reaction in step (1) and / or step (2) is carried out under the protection of an inert gas, which may be nitrogen or argon.

[0038] According to the preparation method of the present invention, optionally, after the reaction in step (1) and / or step (2) is completed, the reaction product can be purified. The purification method includes one or more of the following methods: water washing, extraction, distillation, rectification, molecular distillation, filtration, drying and recrystallization, without particular limitation.

[0039] According to the preparation method of the present invention, optionally, after the reaction in step (1) is completed, the reaction product can be extracted, and the extractant used can be one or more of diethyl ether, ethyl acetate, and dichloromethane.

[0040] According to the preparation method of the present invention, phosphate esters and / or phosphate amine salts with a single structure can be prepared as reaction products, as well as mixtures composed of phosphate esters and / or phosphate amine salts with multiple structures. These reaction products are all intended for the present invention, and their different forms do not affect the achievement of the effects of the present invention. Therefore, in the context of this specification, these reaction products are collectively referred to as phosphate esters and / or phosphate amine salts without distinction. In view of this, according to the present invention, there is no absolute necessity for further purification of the reaction product, or for further separation of a phosphate ester and / or phosphate amine salt with a specific structure from the reaction product. Of course, such purification or separation is preferred for further enhancing the intended effects of the present invention, but is not necessary for the present invention. Nevertheless, examples of purification or separation methods include silica gel column chromatography or preparative chromatography.

[0041] The phosphate esters and / or phosphate amine salts of the present invention have excellent anti-wear properties, friction reduction properties, extreme pressure properties, and good corrosion resistance.

[0042] According to the present invention, component B is alkylated diphenylamine, wherein the alkyl group is preferably C4-C6. 10The alkyl group can be straight-chain or branched, for example, one or more of tert-butyl / isooctyl diphenylamine, dioctyl diphenylamine, and p,p'-diisooctyl diphenylamine. Common commercial brands include IRGANOX L-01 and IRGANOX L-57 from BASF (Germany), T534 from Beijing Xingpu Co., Ltd., LZ5150A from Lubrizol Lanzhou Refinery Additives Co., Ltd., VANLUBE NA, VANLUBE 961, and VANLUBE 81 from Vanderbilt (USA), and RC7001 from Rheinland Chemical Company (Germany). The alkylated diphenylamine is more preferably tert-butyl / isooctyl diphenylamine.

[0043] According to the present invention, component C is a polyisobutylene succinimide ashless dispersant and / or a polyisobutylene succinate pentaerythritol dispersant. The polyisobutylene (PIB) portion of the polyisobutylene succinimide ashless dispersant has a number-average molecular weight of 800–4000, preferably 900–3000, and can be selected from T161 produced by Suzhou Special Oil Products Plant, T161A and T161B produced by Jinzhou Petrochemical Company Additives Plant, LZL157 produced by Lubrizol Lanzhou Refinery Additives Co., Ltd., LZ6418 and LZ6420 produced by Lubrizol, Hitec646 produced by Afton, etc. The polyisobutylene (PIB) portion of the polyisobutylene succinate dispersant has a number-average molecular weight of 500–4000, preferably 700–2500, and can be selected from Lubrizol LZ936.

[0044] According to the present invention, component D is magnesium salicylate and / or calcium sulfonate, preferably a mixture of magnesium salicylate with an alkalinity of (100-400) mgKOH / g and calcium sulfonate with an alkalinity of (200-450) mgKOH / g, with a preferred ratio of 1:0.1-1. Component D can be calcium sulfonate T106B (TBN400) or magnesium salicylate T109 (TBN300) produced by Wuxi Nanfang Additives Co., Ltd.

[0045] According to the present invention, component E is zinc dialkyl dithiophosphate, wherein the alkyl group in the zinc dialkyl dithiophosphate is an alkyl group containing 2 to 12 carbon atoms, preferably an alkyl group containing 2 to 8 carbon atoms, such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-octyl, 2-ethylhexyl. The zinc dialkyl dithiophosphate can be selected from primary alkyl group T202 and T203 produced by Wuxi Southern Petroleum Additives Co., Ltd., primary alkyl group T202, primary alkyl group T203, primary and secondary alkyl group T204, and secondary alkyl group T205 produced by Jinzhou Petrochemical Branch Additives Plant, LZ1371 and LZ1375 produced by Lubrizol, C9417, C9425, and C9426 produced by Infineum, and Hitec7169 and Hitec1656 produced by Afton. The zinc dialkyl dithiophosphate is preferably a mixture of zinc diprimary alkyl dithiophosphate and zinc disecondary alkyl dithiophosphate, with a preferred mass ratio of 1:0.2 to 5.

[0046] According to the present invention, component F is a thiophenol ester type antioxidant. The structure of the thiophenol ester type antioxidant is as follows:

[0047]

[0048] R1 and R2 are each independently H or C1~C 12 Alkyl groups, preferably each independently of H or C1-C9 alkyl groups, more preferably each independently of methyl or tert-butyl, m and n are each independently integers between 0 and 10, preferably each independently of 0, 1 or 2. The thiophenol ester type antioxidant can be selected as 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], common commercial brands include antioxidant 1035 produced by Sichuan Yongye Chemical Co., Ltd., and IRGANOX L115 produced by BASF AG, Germany, etc.

[0049] According to the present invention, component G is a metal corrosion inhibitor, which can be selected from one or more of triazole derivatives, thiazole derivatives, and thiadiazole derivatives. For example, it can be selected from one or more of benzotriazole, benzothiazole, toluenetriazole, octyltriazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-5-hydrocarbon-substituted-1,3,4-thiadiazole, 2-dimercapto-5-dithio-1,3,4-thiadiazole, N,N-dihexylaminomethylenetriazole, and 2-mercaptobenzothiazole. Common commercial brands include T551, T561, and T706 produced by Jinzhou Kangtai Lubricating Oil Additives Co., Ltd.

[0050] According to the present invention, component H is an antiemulsifier, which can be selected from one or more of the following: amine-epoxide condensate, ethylene oxide, propane block polyether, and polyethylene oxide-propylene oxide ether, preferably amine-epoxide condensate, and common commercial brands include T1001, etc.

[0051] According to the present invention, component I is the main component of the lubricating base oil, which may be selected from mineral lubricating oils and / or synthetic lubricating oils. The mineral lubricating oil may be one or more of API Group I, II, and III base oils, with common commercial brands including Group I 150SN, 600SN, Group II 100N, 150N, and Group III 100N, 150N, etc. The synthetic lubricating oil includes one or more of polymerized hydrocarbon oils, alkylbenzenes and their derivatives, ester oils, and Fischer-Tropsch synthetic hydrocarbon oils. Component I is preferably a lubricating base oil with a viscosity index greater than 80, a saturated hydrocarbon mass fraction greater than 90%, and a sulfur content mass fraction less than 0.03%.

[0052] The method for preparing the hydrogen fuel engine lubricating oil composition of the present invention includes the step of mixing the above-mentioned components. The mixing temperature is preferably between 40°C and 90°C, and the mixing time is preferably between 1 hour and 6 hours.

[0053] The hydrogen fuel engine lubricating oil composition of the present invention has excellent high-temperature oxidation resistance, detergency, anti-wear and friction-reducing properties and anti-rust properties, and can significantly reduce the formation of high-temperature deposits. Attached Figure Description

[0054] Figure 1 This is the mass spectrum of product P1 in Example 1 of the present invention.

[0055] Figure 2 This is the mass spectrum of product D1 in Comparative Example 1 of the present invention.

[0056] Figure 3 This is the mass spectrum of product P2 in Example 2 of the present invention.

[0057] Figure 4 This is the mass spectrum of product D2 in Comparative Example 2 of the present invention. Detailed Implementation

[0058] The present invention will be explained and described below through specific embodiments, but these do not constitute a limitation on the present invention.

[0059] The main raw materials used and their sources:

[0060] Methylene diphosphate (95%, Jiangxi Ruiwei Biotechnology Co., Ltd.), methylphosphonic acid (98%, Chongqing Zhangbang Pharmaceutical Technology Co., Ltd.), 2-ethylhexanol (99%, Aladdin Industrial Corporation), 1,1,3,3-tetramethylbutylamine (95%, Acros Organics), 2-decyltetradecylamine (95%, Suzhou Nakai Technology Co., Ltd.), 4-dimethylaminopyridine (99%, TCI (Shanghai) Chemical Industry Development Co., Ltd.), triethylamine (99%, ThermoScientific), dicyclohexylcarbodiimide (98%, TCI (Shanghai) Chemical Industry Development Co., Ltd.), toluene (AR, Tianjin Damao Chemical Reagent Factory), xylene (AR, Tianjin Damao Chemical Reagent Factory), dichloromethane (99%, Beijing Innoka Technology Co., Ltd.), ethyl acetate (99%, Beijing Innoka Technology Co., Ltd.), anhydrous sodium sulfate (98%, Shanghai Maclean Biochemical Technology Co., Ltd.), sodium bicarbonate (98%, Shanghai Maclean Biochemical Technology Co., Ltd.), sodium chloride (98%, Shanghai Maclean Biochemical Technology Co., Ltd.), V81 (4,4-di-tert-octyldiphenylamine) (Vanderbilt Company), T706 (benzotriazole) (Nanjing Ningjiang Chemical Plant).

[0061] The following example uses isooctanol to illustrate the reaction equation for the preparation of phosphate esters:

[0062]

[0063] The reaction products of the phosphate ester prepared by the present invention, as described above, include product A, product B, product C, and product D, which are a mixture. This mixture can be carried out in the next reaction without separation.

[0064] Taking 1,1,3,3-tetramethylbutylamine and the above product as examples, the reaction equation for the preparation of phosphate ester amine salts in this invention is as follows:

[0065]

[0066] Example 1

[0067] The main raw materials include: methylene diphosphonic acid, 2-ethylhexanol, triethylamine, 4-dimethylaminopyridine, dicyclohexylcarbodiimide, dichloromethane, ethyl acetate, anhydrous sodium sulfate, sodium chloride, and sodium bicarbonate.

[0068] The reaction steps for preparing phosphate ester compounds are as follows:

[0069] Disperse methylene diphosphonic acid (1 g, 5.68 mmol, 1.0 eq) in 30 mL of dry dichloromethane, add to a reaction flask, purge with N2 for protection, stir, and heat in an ice-water bath to 0–5 °C. Add dicyclohexylcarbodiimide (4.8075 g, 23.30 mmol, 4.1 eq), stir at 0–5 °C for 30 min, then add 2-ethylhexanol (3.0337 g, 23.30 mmol, 4.1 eq), 4-dimethylaminopyridine (0.4270 g, 3.495 mmol, 0.15 eq), and triethylamine (… 0.3537 g, 3.495 mmol, 0.15 eq) were added and stirred at 0–5 °C for 1 h. The reaction was then continued at room temperature for 24 h with stirring. During the reaction, a white solid (dicyclohexylurea) continuously precipitated from the clear and transparent reaction solution. After the reaction was completed, the white solid was removed by filtration. The reaction solution was washed with saturated sodium bicarbonate solution, extracted with ethyl acetate, and the organic phase was collected. The organic phase was washed with saturated brine and dried with anhydrous sodium sulfate. The solvent and residual 2-ethylhexanol were removed by filtration and rotary evaporation to obtain product P1, which is a pale yellow liquid.

[0070] Structural characterization of product P1 in Example 1

[0071] Product P1 was analyzed by mass spectrometry, see [see details]. Figure 1 .

[0072] The mass spectrometry conditions are as follows:

[0073] Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), model Bruker SolariX XR, magnetic field strength 15T. Experimental conditions: injection rate 120 μL / h, electrospray ionization source, positive ion mode (ESI+), capillary voltage 4500 V, nebulizer 1 bar, drying gas flow rate 4.0 L / min, desiccator temperature 200 °C, TOF 0.6 ms, Q1 mass 150 u, RF 800 Vpp, front and rear baffle voltage 1.8 V, SEP (Sweep Excitation Power) 15, mass-to-charge ratio (m / z) detection range 50–1500, cumulative scans 64 times during sampling. Sample preparation: approximately 0.1 mg / mL sample was prepared using chromatographically pure methanol.

[0074] The relative molecular mass of tetraisooctyl methylene diphosphate is 624.46, and the relative molecular mass of triisooctyl methylene diphosphate is 512.34. Figure 1 In the mass spectrometry, the absorption peak with a mass-to-charge ratio of 625.47204 indicates that tetraisooctyl methylene diphosphate in product P1 has a hydrogen atom bound to an H atom. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 647.453985 is the molecular ion peak of product P1, where tetraisooctyl methylene diphosphate binds to a Na+ ion.+ The molecular ion peak (Na) + (Source: Mass spectrometry ion source); the mass-to-charge ratio mass absorption peak of 513.34684 indicates that product P1 contains triisooctyl methylene diphosphate bound to an H atom. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 535.328784 is the molecular ion peak of product P1, where triisooctyl methylene diphosphate binds to a Na group. + The molecular ion peak (Na) + (Originating from a mass spectrometry ion source).

[0075] In summary, product P1 is a mixture of the two compounds shown in the following formula.

[0076]

[0077] Comparative Example 1

[0078] The main raw materials include: methylphosphonic acid, 2-ethylhexanol, 4-dimethylaminopyridine, dicyclohexylcarbodiimide, dichloromethane, ethyl acetate, anhydrous sodium sulfate, sodium chloride, and sodium bicarbonate.

[0079] The reaction steps for preparing the comparative phosphate ester compounds are as follows:

[0080] Methylphosphoric acid (2 g, 22.828 mmol, 1.0 eq) was dispersed in 60 mL of dry dichloromethane and added to a reaction flask. Under N2 protection, the mixture was stirred and heated in an ice-water bath to 0–5 °C. Dicyclohexylcarbodiimide (4.5123 g, 21.8694 mmol, 1.05 eq) was added, and the mixture was stirred at 0–5 °C for 30 min. Then, 2-ethylhexanol (5.6960 g, 43.7388 mmol, 2.1 eq), 4-dimethylaminopyridine (0.3817 g, 5.207 mmol, 0.15 eq), and trimethylolpropionic acid were added. Ethylamine (0.5269 g, 5.207 mmol, 0.15 eq) was stirred at 0–5 °C for 1 h, and then stirred at room temperature for 24 h. During the reaction, a white solid (dicyclohexylurea) continuously precipitated from the clear and transparent reaction solution. After the reaction was completed, the white solid was removed by filtration. The reaction solution was washed with saturated sodium bicarbonate solution, extracted with ethyl acetate, and the organic phase was collected. The organic phase was washed with saturated brine and dried with anhydrous sodium sulfate. The solution was filtered, and the solvent and residual 2-ethylhexanol were removed by rotary evaporation to obtain product D1, which is a pale yellow liquid.

[0081] Characterization of product D1 in Comparative Example 1

[0082] Product D1 was analyzed by mass spectrometry, see [see details]. Figure 2 The mass spectrometry conditions were the same as those for product P1.

[0083] The relative molecular mass of isooctyl methylphosphonate is 208.12, and the relative molecular mass of diisooctyl methylphosphonate is 320.25. Figure 2 In the mass spectrometry, the absorption peak with a mass-to-charge ratio of 209.130108 indicates that isooctyl methylphosphonate in product D1 has a hydrogen atom bound to an H atom. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 231.112052 is the molecular ion peak of product D1, where isooctyl methylphosphonate binds to a Na group. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 321.255309 indicates that diisooctyl methylphosphonate in product D1 has a molecular ion peak; + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 343.237253 is the molecular ion peak of product D1, where diisooctyl methylphosphonate binds to a Na group. + The molecular ion peak. In summary, product D1 is a mixture of the two compounds shown in the following formula.

[0084]

[0085] Example 2

[0086] The main raw materials include: methylene diphosphonic acid, p-methylphenol, triethylamine, 4-dimethylaminopyridine, dicyclohexylcarbodiimide, dichloromethane, ethyl acetate, anhydrous sodium sulfate, sodium chloride, and sodium bicarbonate.

[0087] The reaction steps for preparing the phosphate ester compounds of the present invention are as follows:

[0088] Disperse methylene diphosphonic acid (1 g, 5.68 mmol, 1.0 eq) in 40 mL of dry dichloromethane, add to a reaction flask, purge with N2 for protection, stir, and heat in an ice-water bath to 0–5 °C. Add dicyclohexylcarbodiimide (4.8075 g, 23.30 mmol, 4.1 eq), stir at 0–5 °C for 30 min, then add p-cresol (2.4884 g, 23.01 mmol, 4.05 eq) and 4-dimethylaminopyridine (0.4270 g, 3.495 mmol, 0.15 eq). Triethylamine (0.3537 g, 3.495 mmol, 0.15 eq) was stirred at 0–5 °C for 1 h, and then stirred at room temperature for 24 h. During the reaction, white solids continuously precipitated from the clear and transparent reaction solution. After the reaction was completed, the white solids were removed by filtration, the reaction solution was washed with saturated sodium bicarbonate solution, extracted with ethyl acetate, and the organic phase was collected. The organic phase was washed with saturated brine and dried with anhydrous sodium sulfate. The solvent and residual p-methylphenol were removed by filtration and rotary evaporation to obtain product P2, which is a pale yellow liquid.

[0089] Characterization of product P2 in Example 2

[0090] The product P2 was analyzed by mass spectrometry, see [see details]. Figure 3 The mass spectrometry conditions were the same as those for product P1.

[0091] The relative molecular mass of tetramethylmethylene diphosphate is 536.15, and the relative molecular mass of trimethylmethylene diphosphate is 446.10. Figure 3 In the mass spectrometry, the absorption peak with a mass-to-charge ratio of 537.160235 indicates that tetramethylmethylene diphosphate ester in product P2 has a bound H atom. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 559.141312 is the molecular ion peak of product P2, where tetramethylmethylene diphosphate is bound to a Na+ ion. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 447.112808 indicates that the product P2 contains trimethylmethylene diphosphate ester bound to an H atom. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 469.094106 indicates that the product P2 contains trimethylmethylene diphosphate ester bound to a Na+ ion. + The molecular ion peak. In summary, product P2 is a mixture of the two compounds shown in the following formula.

[0092]

[0093] Comparative Example 2

[0094] The main raw materials include: methylphosphonic acid, p-methylphenol, 4-dimethylaminopyridine, dicyclohexylcarbodiimide, dichloromethane, ethyl acetate, anhydrous sodium sulfate, sodium chloride, and sodium bicarbonate.

[0095] The reaction steps for preparing the comparative phosphate ester compounds are as follows:

[0096] Methylphosphoric acid (1 g, 11.41 mmol, 1.0 eq) was dispersed in 40 mL of dry dichloromethane and added to a reaction flask. Under N2 protection, the mixture was stirred and heated in an ice-water bath to 0–5 °C. Dicyclohexylcarbodiimide (4.5123 g, 21.8694 mmol, 2.1 eq) was added, and the mixture was stirred at 0–5 °C for 30 min. Then, p-methylphenol (2.3650 g, 21.87 mmol, 2.1 eq), 4-dimethylaminopyridine (0.1907 g, 1.5615 mmol, 0.15 eq), and triethylamine were added. Amine (0.1580 g, 1.5615 mmol, 0.15 eq) was stirred at 0–5 °C for 1 h, and then stirred at room temperature for 24 h. During the reaction, a white solid (dicyclohexylurea) continuously precipitated from the clear and transparent reaction solution. After the reaction was completed, the white solid was removed by filtration. The reaction solution was washed with saturated sodium bicarbonate solution, extracted with ethyl acetate, and the organic phase was collected. The organic phase was washed with saturated brine and dried with anhydrous sodium sulfate. The solvent and residual p-methylphenol were removed by filtration and rotary evaporation to obtain product D2, which is a pale yellow liquid.

[0097] Characterization of product D2 in Comparative Example 2

[0098] Product D2 was analyzed by mass spectrometry, see [see details]. Figure 4 The mass spectrometry conditions were the same as those for product P1.

[0099] The relative molecular mass of di-p-cresol methylphosphonic acid is 276.09, and the relative molecular mass of p-cresol methylphosphonic acid is 186.15. Figure 4 In the mass spectrometry, the absorption peak with a mass-to-charge ratio of 277.098988 indicates that the product D2 contains bis(p-cresol) methylphosphonic acid ester bound with an H atom. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 299.080302 is the molecular ion peak of product D2, where methylphosphonic acid di-p-cresol ester binds to a Na group. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 187.156032 is the molecular ion peak of product D2, where methylphosphonic acid p-cresol ester binds to an H atom. + The molecular ion peak; the mass-to-charge ratio mass absorption peak of 209.157901 is the molecular ion peak of product D2, where methylphosphonic acid p-cresol ester binds to a Na group. + The molecular ion peak. In summary, product D2 is a mixture of the two compounds shown in the following formula.

[0100]

[0101] Example 3

[0102] The main raw materials include: product P1, 1,1,3,3-tetramethylbutylamine, and xylene.

[0103] The reaction steps for preparing the phosphate ester amine salt compounds of the present invention are as follows:

[0104] Product P1 (1g) was dispersed in 30ml of xylene solution and added to a reaction flask equipped with a magnetic stirrer, nitrogen delivery tube, spherical condenser and constant pressure dropping funnel. A xylene (5ml) solution containing 1,1,3,3-tetramethylbutylamine (0.4654g, 3.60mmol) was prepared and poured into the constant pressure dropping funnel. The reaction flask was placed in a 40℃ constant temperature oil bath, the magnetic stirrer was turned on and N2 was introduced for protection, and the xylene solution of 1,1,3,3-tetramethylbutylamine was added dropwise. After the addition was completed, the mixture was stirred at this temperature for 2h, then the temperature was raised to 90℃ and stirred at this temperature for 4h. The xylene was removed by rotary evaporation of the reaction mixture to obtain product P3. Analysis showed that product P3 was a mixture of methylene diphosphate triisooctyl ester-1,1,3,3-tetramethylbutylamine salt and methylene diphosphate tetraisooctyl ester, as shown in the following formula, and was a pale yellow viscous liquid.

[0105]

[0106] Comparative Example 3

[0107] The main raw materials include: product D1, 1,1,3,3-tetramethylbutylamine, and xylene.

[0108] The reaction steps for preparing the comparative phosphate ester amine salt compounds are as follows:

[0109] Product D1 (1g) was dispersed in 30ml of xylene solution and added to a reaction flask equipped with a magnetic stirrer, nitrogen delivery tube, spherical condenser and constant pressure dropping funnel. A xylene (15ml) solution of 1,1,3,3-tetramethylbutylamine (0.1891g, 1.463mmol) was prepared and poured into the constant pressure dropping funnel. The reaction flask was placed in a 40℃ constant temperature oil bath, the magnetic stirrer was turned on and N2 was introduced for protection, and the xylene solution of 1,1,3,3-tetramethylbutylamine was added dropwise. After the addition was completed, the mixture was stirred at this temperature for 2h, then the temperature was raised to 90℃ and stirred at this temperature for 4h. The xylene was removed by rotary evaporation of the reaction mixture to obtain product D3. Analysis showed that product D3 was a mixture of isooctyl methylphosphonate-1,1,3,3-tetramethylbutylamine salt and diisooctyl methylphosphonate as shown in the following formula, which was a pale yellow viscous liquid.

[0110]

[0111] Example 4

[0112] The main raw materials include: product P2, 1,1,3,3-tetramethylbutylamine, and xylene.

[0113] The reaction steps for preparing the phosphate ester amine salt compounds of the present invention are as follows:

[0114] Product P2 (1g) was dispersed in 30ml xylene solution and added to a reaction flask equipped with a magnetic stirrer, nitrogen delivery tube, spherical condenser and constant pressure dropping funnel. A xylene solution of 1,1,3,3-tetramethylbutylamine (0.3185g, 2.46mmol) was prepared and poured into the constant pressure dropping funnel. The reaction flask was placed in a 40℃ constant temperature oil bath, the magnetic stirrer was turned on and N2 was introduced for protection. The xylene solution of 1,1,3,3-tetramethylbutylamine was added dropwise. After the addition was completed, the mixture was stirred at this temperature for 2h. Then the temperature was raised to 90℃ and stirred at this temperature for 4h. The xylene was removed by rotary evaporation of the reaction mixture to obtain product P4. Analysis showed that product P4 was a mixture of trimethylmethylene diphosphate-1,1,3,3-tetramethylbutylamine salt and tetramethylmethylene diphosphate, as shown in the following formula, and was a pale yellow viscous liquid.

[0115]

[0116] Comparative Example 4

[0117] The main raw materials include: product D2, 1,1,3,3-tetramethylbutylamine, and xylene.

[0118] The reaction steps for preparing the comparative phosphate ester amine salt compounds are as follows:

[0119] Product D2 (1g) was dispersed in 30ml of xylene solution and added to a reaction flask equipped with a magnetic stirrer, nitrogen delivery tube, spherical condenser and constant pressure dropping funnel. A xylene (15ml) solution of 1,1,3,3-tetramethylbutylamine (0.7637g, 5.91mmol) was prepared and poured into the constant pressure dropping funnel. The reaction flask was placed in a 40℃ constant temperature oil bath, the magnetic stirrer was turned on and N2 was introduced for protection, and the xylene solution of 1,1,3,3-tetramethylbutylamine was added dropwise. After the addition was completed, the mixture was stirred at this temperature for 2h, then the temperature was raised to 90℃ and stirred at this temperature for 4h. The xylene was removed by rotary evaporation of the reaction mixture to obtain product D4. Analysis showed that product D4 was a mixture of methylphosphonic acid p-cresol ester-1,1,3,3-tetramethylbutylamine salt and methylphosphonic acid xylenol ester as shown in the following formula, which was a pale yellow viscous liquid.

[0120]

[0121] Examples 5-11 and Comparative Examples 5-8 of the hydrogen fuel engine lubricating oil compositions

[0122] According to the formulation in Table 1, each component was added to a mixing container and stirred at 50°C for 3 hours to prepare the hydrogen fuel engine lubricating oil compositions of the present invention, Examples 5-11 and Comparative Examples 5-8.

[0123] The high-temperature oxidation resistance of the oils in Examples 5-11 and Comparative Examples 5-8 was tested using pressure differential scanning calorimetry (PDSC). The test results are expressed as the oxidation induction period (in minutes) of the test samples. The test conditions were: pressure 3.5 MPa and oxygen flow rate 100 mL / min. A longer oxidation induction period indicates better high-temperature oxidation resistance of the test sample.

[0124] The oxidation resistance of the gasoline engine lubricating oils in Examples 5-11 and Comparative Examples 5-8 was tested using the Thin Film Oxygen Outcome (TFOUT) test. The test results are expressed as the oxidation induction period (in minutes) of the test samples. The TFOUT test conditions were: 160°C, IIIE catalyst, and oxygen pressure of 620 kPa. A longer oxidation induction period indicates better oxidation resistance of the test sample.

[0125] Table 1. Lubricating Oil Compositions for Hydrogen Fuel Engines

[0126]

[0127] The detergency of the oils in Examples 5-11 and Comparative Examples 5-8 was tested using an engine crankcase coking simulation test. The method involved adding 300 ml of the test sample to a coking plate simulator, heating it to 160°C, and continuously splashing the oil onto an aluminum plate. After 6 hours, the amount of coke formed on the aluminum plate was weighed and expressed as deposits (mg), simulating deposits on a piston. Higher coke levels indicate poorer detergency of the test sample.

[0128] The detergency of the oils in Examples 5-11 and Comparative Examples 5-8 was tested using a heat pipe coking simulation test. The method involved circulating 15 ml of the test sample in a heat pipe while simultaneously injecting oxygen to accelerate oil aging. The sample was heated to 330°C, and the glass tube wall was scored after 8 hours. The maximum score was 10; a lower score indicated poorer detergency of the test sample.

[0129] High-temperature wear resistance tests were conducted on the oils in Examples 5-11 and Comparative Examples 5-8 using a high-frequency reciprocating friction testing machine. The test conditions were: load 1000g, temperature 120℃, and test time 60min. The smaller the measured wear scar diameter and the smaller the friction coefficient, the better the wear resistance and friction reduction performance of the test sample.

[0130] BRT ball corrosion tests were conducted on the oils from Examples 5-11 and Comparative Examples 5-8. Using the lubricating oil compositions prepared in the examples or comparative examples as test samples, the metal balls protected by the test samples were continuously exposed to acidic liquid and air during the entire 18-hour bench test. After the test, the reflective surface intensity of the metal balls was measured to obtain grayscale test values, which were used to determine the corrosion area and thus evaluate the rust resistance of the test samples. The test conditions were: an injection rate of acetic acid / hydrobromic acid / hydrochloric acid / deionized water of 0.19 ml / h, an air flow rate of 40 ml / min, and an oil temperature of 48°C. A higher score indicates better rust prevention performance of the test sample.

[0131] The test results of PDSC test, TFOUT test, coking simulation test, high frequency reciprocating friction test and BRT ball corrosion test are shown in Table 2.

[0132] As can be seen from Table 2, the hydrogen fuel engine lubricating oil composition of the present invention has excellent high-temperature oxidation resistance, detergency, anti-wear and friction reduction properties and anti-rust properties.

[0133] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features.

[0134] Table 2

[0135]

Claims

1. A lubricating oil composition for a hydrogen fuel engine, comprising the following components: (A) Phosphate esters and / or phosphate ester amine salts, comprising 0.1% to 15% (preferably 0.5% to 10%) of the total mass of the composition; (B) Alkylated diphenylamine, comprising 0.1% to 10% (preferably 0.5% to 5%) of the total mass of the composition; (C) Polyisobutylene succinimide ashless dispersant and / or polyisobutylene succinate pentaerythritol dispersant, accounting for 3% to 15% (preferably 5% to 10%) of the total mass of the composition; (D) Magnesium salicylate and / or calcium sulfonate, comprising 0.2% to 10% (preferably 0.5% to 8%) of the total mass of the composition; (E) Zinc dialkyl dithiophosphate, comprising 0.1% to 5% (preferably 0.2% to 3%) of the total mass of the composition; (F) Thiophenol ester type antioxidant, accounting for 0.02% to 10% (preferably 0.1% to 4%) of the total mass of the composition; (G) Metal corrosion inhibitor, comprising 0.01% to 3% (preferably 0.02% to 1%) of the total mass of the composition; (H) Demulsifier, comprising 0.02% to 5% (preferably 0.1% to 3%) of the total mass of the composition; (I) Main component of lubricating base oil; The structure of the phosphate ester and / or phosphate ester amine salt is shown in formula (X): In formula (X), each R1 group is independently selected from H, C1 to C1. 30 Straight-chain or branched alkyl groups, C3-C4 30 cycloalkyl, C7-C 30 Alkylphenyl, C7-C 30 The alkoxyphenyl group, R2 group is selected from C8 to C9. 30 The linear or branched alkyl group, n is any number between 0 and 4.4; the formula (X) contains m R1 groups, each independently selected from C1 to C2. 30 Straight-chain or branched alkyl groups, C3-C4 30 cycloalkyl, C7-C 30 Alkylphenyl, C7-C 30 The alkoxyphenyl group, where m is any number between 1 and 4.

2. The hydrogen fuel engine lubricating oil composition according to claim 1, characterized in that, n is any number between 1 and 4.

3. The hydrogen fuel engine lubricating oil composition according to claim 1, characterized in that, The C7~C 30 The alkylphenyl group is selected from the following groups: 4-eicosylphenyl, 4-nonadecanylphenyl, 4-octadecylphenyl, 4-heptadecylphenyl, 4-hexadecylphenyl, 4-pentadecanylphenyl, 4-tetradecylphenyl, 4-tridecylphenyl, 4-dodecylphenyl, 4-undecylphenyl, 4-decylphenyl, 4-decylphenyl, 4-nonylphenyl, 4-octylphenyl, 4-heptylphenyl, 4-hexylphenyl, 4-pentylphenyl, 4-butylphenyl, 4-propylphenyl, 4-ethylphenyl, 4-methylphenyl, 4-sec-octylphenyl; wherein C7~C 30 The alkoxyphenyl group is selected from the following groups: 4-eicosethoxyphenyl, 4-nonadecanethoxyphenyl, 4-octadecethoxyphenyl, 4-heptadecethoxyphenyl, 4-hexadecethoxyphenyl, 4-pentadecanethoxyphenyl, 4-tetradecethoxyphenyl, 4-tetanecanethoxyphenyl, 4-dodecethoxyphenyl, 4-undecethoxyphenyl, 4-decyloxyphenyl, 4-nonoxyphenyl, 4-octyloxyphenyl, 4-heptyloxyphenyl, 4-hexyloxyphenyl, 4-pentoxyphenyl, 4-butoxyphenyl, 4-propoxyphenyl, 4-ethoxyphenyl, 4-methoxyphenyl; the R2 group is selected from tert-butyl, tert-hexyl, 1,1,3,3-tetramethylbutyl, 2-decyltetradecyl.

4. The hydrogen fuel engine lubricating oil composition according to claim 1, characterized in that, The phosphate ester and / or phosphate ester amine salt is any one group of compounds from group (a), group (b), group (c), and group (d) below, or a combination thereof in any proportion:

5. The hydrogen fuel engine lubricating oil composition according to claim 1, characterized in that, The method for preparing the phosphate ester and / or phosphate ester amine salt includes the following steps (1) and optional step (2): (1) An esterification reaction is carried out between methylene diphosphate and R1OH, and the esterification product is collected; wherein the R1 group is selected from C1 to C1. 30 Straight-chain or branched alkyl groups, C3-C4 30 cycloalkyl, C7-C 30 Alkylphenyl, C7-C 30 alkoxyphenyl; (2) The esterification product from step (1) is subjected to an amination reaction with H2N-R2, and the product is collected; wherein the R2 group is selected from C8 to C6. 30 Straight-chain or branched alkyl groups.

6. The hydrogen fuel engine lubricating oil composition according to claim 5, characterized in that, In step (1), the molar ratio between methylene diphosphate and R1OH is 1:1.1 to 4.1; the temperature at which methylene diphosphate and R1OH undergo esterification is -30℃ to 50℃; and the time for the esterification reaction between methylene diphosphate and R1OH is 2 to 24 hours.

7. The hydrogen fuel engine lubricating oil composition according to claim 5, characterized in that, In step (2), the molar ratio between the esterification product of step (1) and H2N-R2 is 1:1 to 4.1; the temperature at which the esterification product of step (1) undergoes amination reaction with H2N-R2 is 40 to 120°C; and the time for the amination reaction between the esterification product of step (1) and H2N-R2 is 0.5 to 20 h.

8. The hydrogen fuel engine lubricating oil composition according to claim 5, characterized in that, The R1OH is selected from C1 to C1. 30 fatty alcohols, C7-C 30 Aromatic alcohols, C7-C 30 Alkoxy aromatic alcohols; the H2N-R2 is selected from C8 to C96. 30 Straight-chain or branched alkylamines.

9. The hydrogen fuel engine lubricating oil composition according to any one of claims 1 to 8, characterized in that, The alkyl group in the alkylated diphenylamine is C4-C6. 10 The polyisobutylene succinimide dispersant contains linear or branched alkyl groups; the polyisobutylene moiety in the polyisobutylene succinate dispersant has a number-average molecular weight of 800–4000, and the polyisobutylene pentaerythritol succinate dispersant has a number-average molecular weight of 500–4000; the magnesium salicylate is magnesium salicylate with an alkalinity of (100–400) mgKOH / g, and the calcium sulfonate is calcium sulfonate with an alkalinity of (200–450) mgKOH / g; the alkyl group in the dialkyl dithiophosphate zinc is an alkyl group containing 2 to 12 carbon atoms; the structure of the thiophenol ester type antioxidant is: R1 and R2 are each independently H or C1~C 12 Alkyl groups, m and n are each independently integers between 0 and 10; the metal corrosion inhibitor is selected from one or more of triazole derivatives, thiazole derivatives and thiadiazole derivatives; the demulsifier is selected from one or more of amine-epoxide condensates, ethylene oxide, propane block polyethers, and polyethylene oxide-propylene oxide ethers; the lubricating base oil is selected from mineral lubricating oils and / or synthetic lubricating oils.

10. A method for preparing a hydrogen fuel engine lubricating oil composition according to any one of claims 1 to 9, comprising the step of mixing the components therein.

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