Additive masterbatch for hybrid engine oil, method for preparing the same, use thereof, and hybrid engine lubricating oil

Abstract

The present application relates to the technical field of lubricating oil additives, and discloses an additive mother liquor for hybrid engine oil, a preparation method and application thereof, and a hybrid engine lubricating oil. The mother liquor comprises a viscosity index improver, an ashless dispersant, a low total base number calcium alkyl salicylate detergent, zinc dialkyldithiophosphate, an amide ester type friction modifier, a hindered phenol antioxidant and an alkylated diphenylamine antioxidant, an alkyl succinate anti-rust agent, a phenolic resin modified polyester demulsifier without an oxyalkylene chain segment, an oil-soluble poly(meth)acrylate boundary lubrication enhancer with both ends capped by hydroxyl groups, and a polyether modified polysiloxane / dimethyl polysiloxane anti-foam system without a fluorine structure. By synergistically limiting the chemical structure, measurable parameters and dosage window of key components, the obtained hybrid engine lubricating oil has good demulsification, low foam, air release and boundary anti-wear performance in response to the requirements of low ash constraints, condensate water intrusion and fuel dilution working conditions.

Description

Technical Field

[0001] This invention relates to the field of lubricant additive technology, and in particular to a mother liquor additive for hybrid engine oil, its preparation method, its application, and hybrid engine lubricant. Background Technology

[0002] With the development of hybrid vehicles, the operating conditions of engines have changed significantly compared to traditional gasoline vehicles. Hybrid engines typically do not operate continuously but frequently switch between electric and hydraulic drive, resulting in characteristics such as longer low-temperature operating times, more intermittent operation, and more frequent start-stop cycles. Especially in short-distance urban driving, at low speeds, and in low ambient temperatures, it is more difficult for engines to maintain high oil temperatures for extended periods. This leads to significant differences in the thermal history, contamination accumulation patterns, and failure mechanisms of engine oils compared to traditional gasoline engine oils, thus placing more complex and comprehensive performance requirements on engine oils.

[0003] Under the aforementioned hybrid operating conditions, moisture is more likely to accumulate in the engine oil. Due to shorter engine operating hours and more frequent engine shutdowns, condensate entering the crankcase often cannot evaporate and be discharged in time, thus increasing the risk of water contamination in the engine oil. With the accumulation of moisture, the engine oil is more prone to emulsification, decreased water separation performance, and the formation of white sludge or mud, thereby affecting the oil's cleanliness, stability, and ability to protect metal surfaces.

[0004] At the same time, fuel is more likely to enter and remain in the engine oil. During cold starts, short-distance operation, and frequent start-stop cycles in hybrid engines, fuel is more likely to enter the crankcase due to cylinder wall wetting and fuel injection impact, and it is difficult to evaporate in time at lower oil temperatures, leading to fuel dilution in the engine oil. Fuel dilution reduces engine oil viscosity, thins the oil film, and further affects lubrication performance, anti-wear ability, and service life.

[0005] Water contamination and fuel dilution are usually not isolated phenomena under hybrid operating conditions, but can occur simultaneously and exacerbate each other. Their combined effect not only exacerbates emulsification and sludge formation, but also promotes the accumulation of acidic contaminants, increasing the risk of corrosion and rust on metal components, and interfering with the normal function of additive systems, leading to a decline in the overall protective performance of the engine oil. Therefore, hybrid engine oils not only need to possess conventional lubrication, detergency, dispersion, and oxidation resistance, but also need to better balance resistance to water contamination, fuel dilution, and corrosion.

[0006] Under low-temperature short-distance and frequent start-stop conditions, water pollution should be kept under control. This means avoiding the risk of cold start and functional stratification caused by abnormal agglomeration of the aqueous phase during low-temperature shutdown, while also reducing the tendency for reemulsification in subsequent operation, so as to balance corrosion control, sludge control and lubrication protection.

[0007] Furthermore, the frequent start-stop cycles of hybrid engines mean that the friction pairs will enter the boundary lubrication state more often. If this is compounded by factors such as water contamination, fuel dilution leading to a thinner oil film, and interference with additive effectiveness, it can easily lead to increased instantaneous and cumulative wear. Especially when the engine restarts from a stopped state or during rapid changes in operating conditions, the engine oil needs to recover and maintain sufficient lubrication protection capabilities within a short period of time. This places higher demands on the engine oil's boundary anti-wear performance, foam control capabilities, and air release performance.

[0008] Therefore, hybrid engine oils face not just a single failure problem, but a complex interplay of multiple factors including low temperature, contamination accumulation, emulsification, corrosion, foam / air entrainment, and boundary wear. Existing general-purpose engine oil systems often struggle to achieve a balance between multiple properties such as resistance to water contamination / demulsification, resistance to fuel dilution, low foaming and good air release, corrosion resistance, and boundary wear resistance. Therefore, there is an urgent need to develop an engine oil additive masterbatch and corresponding formulation system with a clearly defined component structure, a repeatable preparation process, and suitability for hybrid operating conditions to meet the comprehensive lubrication and protection requirements of hybrid engines. Summary of the Invention

[0009] To address the problems of existing hybrid engine oils, such as water contamination accumulation, fuel dilution, emulsification, corrosion, foam / air entrainment, and increased boundary wear under low-temperature, intermittent operation, and frequent start-stop conditions, and the difficulty of simultaneously achieving multiple properties such as demulsification, anti-contamination effects, low foaming, rapid air release, and boundary wear resistance in existing general-purpose engine oil systems, this invention provides a hybrid engine oil additive mother liquor, its preparation method, its application, and a hybrid engine lubricant. The additive mother liquor, through synergistic definition of the structure and dosage window of a low total base number calcium alkyl salicylate detergent, a phenolic resin-modified polyester demulsifier without oxidized olefin segments, a fluorine-free polyether-modified polysiloxane / polydimethylsiloxane parallel antifoaming system, and an oil-soluble poly(meth)acrylate boundary lubrication enhancer with hydroxyl-terminated ends, achieves hybrid engine lubricant with better demulsification performance, low foaming performance, air release performance, and boundary wear resistance, specifically addressing the requirements of condensate intrusion and fuel dilution conditions.

[0010] One objective of this invention is to provide a masterbatch additive for hybrid engine oils, thereby addressing at least one of the technical problems existing in the prior art. This invention achieves a balance between rapid demulsification, low foaming, good air release, and enhanced boundary lubrication through a multi-component synergistic design. It aims to alleviate the performance contradictions of hybrid engine oils under conditions of frequent start-stop cycles, condensate intrusion, fuel dilution, and the resulting emulsification, sludge deposition, corrosion, and decreased lubrication protection.

[0011] The second objective of this invention is to provide a method for preparing a mother liquor for additives in hybrid engine oils.

[0012] The third objective of this invention is to provide a hybrid engine oil additive mother liquor or a hybrid engine oil additive mother liquor prepared by the aforementioned preparation method, and its application in the preparation of hybrid engine lubricating oil.

[0013] The fourth objective of this invention is to provide a lubricating oil for hybrid engines.

[0014] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a masterbatch for hybrid engine oil. Based on the total mass of the masterbatch (100%), excluding the amount of antifoaming agent (in ppm by mass), the masterbatch comprises: 35%-55% styrene-ethylene / propylene block copolymer viscosity index improver, 10%-18% polyisobutylene succinic anhydride polyamine ashless dispersant, 2%-5% polyester-type ashless dispersant, 3%-6% low total base number calcium alkyl salicylate detergent, 3.5%-6% zinc dialkyl dithiophosphate, 1%-3% amide ester-type friction modifier, and 0% hindered phenolic antioxidant. 0.8%-2%, alkylated diphenylamine antioxidant 2.5%-5%, alkyl succinate rust inhibitor 0.3%-1.5%, phenolic resin modified polyester demulsifier 0.1%-0.4%, polymethyl methacrylate pour point depressant 0.1%-1%, boundary lubrication enhancer 0.1%-0.6%, wherein the boundary lubrication enhancer is an oil-soluble poly(methyl)acrylate enhancer with hydroxyl-terminated ends and a number average molecular weight of 5000-20000; 50-200% fluorine-free polyether modified polysiloxane The additive contains ppm, 20-100 ppm of polydimethylsiloxane, and the balance carrier base oil; wherein the total base value of the low total base number calcium alkyl salicylate is 30-80 mg KOH / g, the phenolic resin modified polyester demulsifier is free of oxidized olefin segments, has a hydrophilic-lipophilic balance value of 4-6, and a number average molecular weight of 1500-3000, the number average molecular weight of the fluorine-free polyether modified polysiloxane is 3000-10000, the content of terminal active functional groups is not greater than 0.5%, and the additive mother liquor is free of magnesium-based detergents, molybdenum-containing compounds, demulsifiers mainly composed of ethylene oxide or propylene oxide block structures and ethoxylated alcohol structures, and fluorinated silicone polyether antifoaming agents.

[0015] Furthermore, the viscosity index improver of the styrene-ethylene / propylene block copolymer includes: styrene-ethylene / propylene diblock copolymer; preferably, the number average molecular weight of the viscosity index improver of the styrene-ethylene / propylene block copolymer is 80,000 to 200,000 (e.g., 120,000).

[0016] Preferably, the boundary lubrication enhancer is an oil-soluble poly(meth)acrylate with hydroxyl groups at both ends, and its number average molecular weight is 5000-20000. The repeating unit of the poly(meth)acrylate contains multiple ester carbonyl groups as polar action sites and terminal hydroxyl groups as hydrogen bond donors, so that the terminal groups and multiple acceptor sites in the main chain and / or side chain jointly provide multiple polar action sites, which is beneficial to the formation of a dynamic adsorption protective layer on the metal surface, and takes into account boundary anti-wear, demulsification and foam suppression / air release performance within the dosage range of 0.10% to 0.60%.

[0017] Preferably, the carrier base oil includes one or more of API Group III base oils (hydrocracking / hydroisomerization base oils), synthetic base oils, alkylated aromatic oils, and polyol esters. The synthetic base oil is a chemically synthesized base oil; the alkylated aromatic oil and polyol ester can generally also be classified as synthetic base oils in a broader sense (API Group V).

[0018] Preferably, the polymethacrylate pour point depressant has a number average molecular weight of 15,000; the polymethacrylate pour point depressant is mainly used to improve low-temperature fluidity.

[0019] Preferably, the polyether-modified polysiloxane and polydimethylsiloxane are used as antifoaming agents; the polyether-modified polysiloxane is a fluorine-free polyether-modified polysiloxane with a number-average molecular weight of 3000-10000 and a terminal active functional group content of no more than 0.5%; the polydimethylsiloxane is a methyl-terminated or hydroxyl-terminated polydimethylsiloxane with a kinematic viscosity of 1000-30000 mmHg at 25°C. 2 / s (e.g., 12500 mm) 2 / s), with a number average molecular weight of 5,000 to 30,000 (e.g., 15,000).

[0020] Secondly, the present invention provides a method for preparing a mother liquor for additives in hybrid engine oils, comprising the following steps: (a) Mix a portion of the carrier base oil with a viscosity index improver for styrene-ethylene / propylene block copolymers and a polymethyl methacrylate pour point depressant, and stir at 70-110°C until completely dissolved; (b) Add polyisobutylene succinic anhydride polyamine ashless dispersant, polyester ashless dispersant, low total base number calcium alkyl salicylate detergent, dialkyl dithiophosphate zinc and amide ester friction modifier at 90-110℃ and mix evenly; (c) After cooling, first add hindered phenolic antioxidant, alkylated diphenylamine antioxidant and alkyl succinate rust inhibitor at 68-75℃, then add phenolic resin modified polyester demulsifier and boundary lubrication enhancer at 55-65℃, and mix evenly. (d) Replenish the carrier base oil except for the one used to dilute the antifoaming agent, and filter it to remove polymer gel and solid impurities; (e) At 40-50°C, the polyether-modified polysiloxane and polydimethylsiloxane without fluorine structure are pre-diluted with the reserved carrier base oil and then slowly added to the mixture obtained in step (d), and mixed at low speed to obtain the additive mother liquor for the hybrid engine oil.

[0021] Preferably, the filtration accuracy of step (d) is no greater than 5 micrometers.

[0022] Thirdly, the present invention provides the application of the hybrid engine oil additive mother liquor or the hybrid engine oil additive mother liquor prepared by the preparation method in the preparation of hybrid engine lubricating oil. Preferably, the hybrid engine oil additive mother liquor is added to the lubricating base oil at 20% of the total mass of the hybrid engine lubricating oil for blending.

[0023] Fourthly, the present invention provides a hybrid engine lubricating oil, comprising a lubricating base oil and a hybrid engine oil additive mother liquor or a hybrid engine oil additive mother liquor prepared by the aforementioned preparation method, wherein the hybrid engine oil additive mother liquor accounts for 20% of the total mass of the hybrid engine lubricating oil. Preferably, the lubricating base oil comprises one or more of API Group III base oils, PAO base oils, alkylated aromatic oils, and polyol esters.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention addresses the complex problems of water pollution accumulation, fuel dilution, corrosion, and boundary wear in hybrid engines under low-temperature, intermittent operation, and frequent start-stop conditions. It synergistically limits the use of detergents, demulsifiers, anti-foaming systems, and boundary lubrication enhancers. The resulting additive mother liquor is not a single performance improvement system, but a hybrid engine-specific mother liquor system that can take into account demulsification, low foaming, rapid air release, and boundary wear resistance.

[0025] 2. This invention uses a low total base number calcium alkyl salicylate detergent, combined with a phenolic resin modified polyester demulsifier that does not contain oxidized olefin segments. While controlling the ash and metal element system, it is beneficial to improve the water separation performance under water pollution conditions, reduce the tendency of emulsification and sludge formation, and mitigate the impact of contaminant accumulation on the stability of lubricating oil.

[0026] 3. This invention uses a low-dose parallel antifoaming system composed of fluorine-free polyether-modified polysiloxane and polydimethylsiloxane. Without introducing fluorine-containing silicone polyether antifoaming agents, it can balance foam suppression and air release performance, which is beneficial to reducing the impact of air entrainment on lubrication stability and oil supply continuity.

[0027] 4. The present invention preferably uses an oil-soluble poly(meth)acrylate boundary lubrication enhancer with hydroxyl end caps. Under the conditions of frequent engine start-stop and repeated entry into the boundary lubrication state, it is beneficial to form a dynamic adsorption protective layer on the metal friction surface, thereby improving the boundary wear resistance and reducing the risk of cumulative wear.

[0028] 5. This invention binds the structure and dosage window of key components as a whole, and further limits the free use of magnesium-based detergents, molybdenum-containing compounds, demulsifiers mainly composed of ethylene oxide or propylene oxide block structures and ethoxylated alcohol structures, and fluorinated silicone polyether antifoaming agents. This helps to reduce mutual interference between systems, so that the resulting hybrid engine lubricating oil achieves a better comprehensive balance among multiple key indicators, and facilitates industrial formulation development and application.

[0029] 6. This invention addresses the challenges of frequent start-stop cycles, condensate intrusion, fuel dilution, air entrainment, and the coexistence of low ash content and specific component limitations in hybrid engines. By synergistically limiting the structure, measurable parameters, and dosage window of low total base number calcium alkyl salicylate, phenolic resin modified polyester demulsifier without oxidized olefin segments, a parallel system of polyether modified polysiloxane and polydimethylsiloxane without fluorine structure, and oil-soluble poly(meth)acrylate boundary lubrication enhancer with hydroxyl end caps, the resulting hybrid engine lubricating oil simultaneously achieves better demulsification, low foaming, air release, and boundary anti-wear performance. Detailed Implementation

[0030] Unless otherwise defined herein, the scientific and technical terms used in this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0031] The technical solution of the present invention will be clearly and completely described below with reference to embodiments. The described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention. In view of this, the present invention provides a mother liquor for hybrid engine oil additives. This mother liquor is not a general-purpose concentrated composition, but is specifically designed for hybrid engines with frequent start-stop cycles, condensate and fuel dilution, air entrainment, and low ash content and specific component restrictions. By synergistically limiting a low total base number calcium alkyl salicylate, a phenolic resin modified polyester demulsifier without oxidized olefin segments, a fluorine-free polyether modified polysiloxane / polydimethylsiloxane parallel system, and an oil-soluble poly(meth)acrylate boundary lubrication enhancer with hydroxyl-terminated ends in a single mother liquor, it achieves synergistic optimization of demulsification, low foaming / rapid air release, and boundary wear resistance. The hybrid engine oil additive mother liquor provided by the present invention is a special concentrated composition for the development of hybrid engine lubricant formulations.

[0032] In a preferred embodiment, based on 100% of the total mass of the additive mother liquor for hybrid engine oil, the components, excluding the antifoaming agent (in ppm by mass), include the following components by mass percentage: The viscosity index improver for styrene-ethylene / propylene block copolymers is 35% to 55%, for example, it can be 35%, 40%, 45%, 50%, 55%, etc. The ashless dispersant is polyisobutylene-based succinic anhydride polyamine at 10%–18%, for example, 10%, 12%, 14%, 16%, 18%, etc. Polyester-type ashless dispersant 2% to 5%, for example, 2%, 3%, 4%, 5%, etc.; Low total base number calcium alkyl salicylate detergents are available at 3% to 6%, for example, 3%, 4%, 5%, 6%, etc. Zinc dialkyl dithiophosphate 3.5% to 6%, for example, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, etc.; Amide ester type friction modifiers: 1% to 3%, for example, 1%, 2%, 3%, etc.; Hindered phenolic antioxidants: 0.8%–2%, for example, 0.8%, 1%, 1.5%, 2%, etc. Alkylated diphenylamine antioxidant 2.5% to 5%, for example, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.; Alkyl succinate rust inhibitors are used at concentrations of 0.3% to 1.5%, for example, 0.3%, 0.5%, 1%, 1.5%, etc. The phenolic resin modified polyester demulsifier is used at a concentration of 0.1% to 0.4%, for example, it can be 0.1%, 0.2%, 0.3%, 0.4%, etc. Polymethyl methacrylate pour point depressants are used at a concentration of 0.1% to 1%, for example, 0.1%, 0.5%, 1%, etc. Boundary lubrication enhancer 0.1% to 0.6%, wherein the boundary lubrication enhancer is an oil-soluble poly(meth)acrylate with hydroxyl ends capped; for example, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, etc.; Polyether-modified polysiloxane 50-200 ppm, for example, 50 ppm, 100 ppm, 150 ppm, 200 ppm, etc.; Polydimethylsiloxane 20-100 ppm, for example, 20 ppm, 40 ppm, 60 ppm, 80 ppm, 100 ppm, etc.; The remainder is carrier base oil.

[0033] Except for antifoaming agents at mass ppm (10 -6 Except for the amount of antifoaming agent, the remaining components are expressed as a percentage by mass; after converting the amount of antifoaming agent to a percentage by mass, the total amount of each component and the carrier base oil is 100%.

[0034] In this application, unless otherwise stated, the number average molecular weight was determined by gel permeation chromatography using polystyrene as a standard; the total base number was determined according to ASTM D2896; the kinematic viscosity was determined according to ASTM D445; the hydrophilic-lipophilic balance was calculated using the Davis method; 'free' means not actively added as an effective functional component, and if unavoidable trace impurities are introduced due to raw materials, the mass fraction of any single impurity in the additive mother liquor is not higher than 0.01%; 'fluorine-free structure' means that the molecular structure does not contain CF bonds; 'free of oxidized olefin segments' means that the molecular structure does not contain polyether segments with -CH2CH2O- or -CH2CH(CH3)O- as repeating units; 'oil-soluble' means that after adding 1.0% by mass of the carrier base oil described in the examples at 25°C and standing for 24 h, there is no visible layering, precipitation, or flocculation.

[0035] In this application, the content of terminal active functional groups refers to the mass percentage of reactive terminal functional groups such as hydroxyl, amino, alkoxy, and silane in the total mass of polyether-modified polysiloxane, which can be determined by ¹H NMR or chemical titration.

[0036] The "4" in PAO 4 and the "4 cSt" in API Group III base oil (4 cSt) both refer to a kinematic viscosity of approximately 4 mmHg at 100°C. 2 / s.

[0037] The hybrid engine described in this application includes a gasoline engine that works in conjunction with an electric motor in hybrid electric vehicles and plug-in hybrid electric vehicles; the fuel used in the fuel dilution is preferably automotive gasoline.

[0038] In some preferred embodiments, the viscosity index improver of the styrene-ethylene / propylene block copolymer comprises a styrene-ethylene / propylene diblock copolymer; the number average molecular weight of the styrene-ethylene / propylene block copolymer viscosity index improver is 80,000 to 200,000 (e.g., 120,000). Preferably, the copolymer contains 5% to 17% by mass of styrene structural units, and the ethylene / propylene blocks are hydrogenated diene blocks with a degree of hydrogenation of not less than 95%.

[0039] Zinc dialkyl dithiophosphate is a multifunctional additive with anti-wear, anti-oxidation, and anti-corrosion functions. It can form a protective layer with a phosphorus-containing reactive film (mainly polyphosphate / thiophosphate structure) on the surface of the friction pair metals, thereby effectively inhibiting the wear and corrosion of engine components under high load and high temperature conditions. Preferably, the alkyl group in the zinc dialkyl dithiophosphate is a C3-C12 primary alkyl group, a C3-C12 secondary alkyl group, or a combination thereof.

[0040] Amide ester-type friction modifiers can form a directional adsorption film on metal surfaces (polar group adsorption, long chain extension), reducing direct metal-to-metal contact. Especially under boundary lubrication conditions such as start-stop, low speed, and high load, they maintain the oil film and reduce instantaneous wear. By reducing frictional resistance and energy loss, they improve efficiency (especially noticeable in hybrid systems with frequent start-stop cycles). Preferably, the amide ester friction modifier is N-(2-hydroxyethyl)-N-(2-C12~C22 fatty acyl oxyethyl)C12~C22 fatty amide; more preferably, the fatty acyl group is C16~C18.

[0041] Preferably, the ashless dispersant includes polyisobutylene succinic anhydride polyamine-based ashless dispersant and polyester-based ashless dispersant, both of which are used together. The polyisobutylene succinic anhydride polyamine-based ashless dispersant can be prepared by condensing polyisobutylene succinic anhydride with a number average molecular weight of 700–2300 with ethylene polyamine; the polyester-based ashless dispersant can be prepared by esterifying polyisobutylene succinic anhydride with a number average molecular weight of 700–2300 with C3–C6 polyols.

[0042] The polyisobutylene succinic anhydride polyamine ashless dispersant can be prepared by condensation and dehydration of polyisobutylene succinic anhydride with a number average molecular weight of 700-2300 and ethylene polyamine at 120-180°C; the ethylene polyamine includes one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and polyethylene polyamine. The polyester-type ashless dispersant can be prepared by esterification of polyisobutylene succinic anhydride with a number average molecular weight of 700-2300 and C3-C6 polyol at 150-220°C; the C3-C6 polyol includes one or more of glycerol, trimethylolpropane, and pentaerythritol.

[0043] Preferably, the metal detergent is a low total base calcium alkyl salicylate; the alkyl group in the calcium alkyl salicylate is C12-C24 alkyl, and its total base value, as measured by ASTM D2896, is 30-80 (e.g., 64) mg KOH / g. The low total base calcium alkyl salicylate can be obtained by neutralizing C12-C24 alkyl salicylic acid with a calcium source, followed by low-degree carbonation or no carbonation treatment; alternatively, commercially available calcium alkyl salicylate detergents that meet the above structure and total base value range can be selected.

[0044] Preferably, the hindered phenolic antioxidant includes one or more of 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butylphenol derivatives, and alkylated hindered phenols. The alkylated diphenylamine antioxidant includes one or more of C4-C12 alkyl-substituted diphenylamines.

[0045] Preferably, the alkyl succinate rust inhibitor is a C8-C24 alkyl succinate monoester, a C8-C24 alkyl succinate half-ester, or a combination thereof.

[0046] Preferably, the alkyl succinate rust inhibitor is a C8-C24 alkyl succinate monoester, a C8-C24 alkyl succinate half-ester, or a combination thereof.

[0047] Preferably, the demulsifier includes a phenolic resin modified polyester demulsifier; the phenolic resin modified polyester demulsifier is a phenolic resin modified polyester without oxidized olefin segments; the hydrophilic-lipophilic balance value of the phenolic resin modified polyester demulsifier is 4 to 6 calculated by the Davis method; the number average molecular weight of the phenolic resin modified polyester demulsifier is 1500 to 3000; when coexisting with ashless dispersants, low total base number calcium alkyl salicylate detergents and siloxane systems within the above range, it is beneficial to obtain rapid demulsification and a lower reemulsification tendency when addressing the requirements of condensate intrusion and fuel dilution conditions in hybrid engine oils. Specifically, the phenolic resin modified polyester demulsifier, within the hydrophilic-lipophilic balance value and number-average molecular weight range defined in this invention, coexists with polyisobutylene succinic anhydride polyamine ashless dispersant, polyester ashless dispersant, low total base number calcium alkyl salicylate detergent, and polyether modified polysiloxane and polydimethylsiloxane, so that the hybrid engine oil using this mother liquor has rapid demulsification and low reemulsification tendency under the conditions of condensate intrusion and fuel dilution.

[0048] The phenolic resin modified polyester demulsifier without oxidized olefin segments can be obtained by esterification reaction of alkylphenolic resin formed from C8-C12 alkylphenol and formaldehyde with C16-C22 fatty acids, C4-C10 diacids or their anhydrides and C2-C6 polyols; its molecule contains hydrophobic segments of phenolic resin and fatty acid polyester segments, but does not contain polyether repeating segments formed by ring opening of ethylene oxide or propylene oxide.

[0049] Preferably, the boundary lubrication enhancer is an oil-soluble poly(meth)acrylate with hydroxyl groups at both ends. Within the dosage range of 0.10% to 0.60%, it is beneficial to form an adsorption layer containing hydroxyl and ester carbonyl interaction sites on the metal surface, reducing boundary friction and wear under hybrid start-stop and low-speed high-load conditions, and within this dosage range, it does not impair demulsification, foam suppression and air release performance.

[0050] More preferably, the boundary lubrication enhancer is an oil-soluble poly(meth)acrylate with hydroxyl groups at both ends; its number average molecular weight is 5000-20000; the poly(meth)acrylate repeating unit contains multiple ester carbonyl groups as polar action sites, and the hydroxyl groups at both ends as polar end groups, which together provide multiple polar action sites, thereby facilitating the formation of a dynamic adsorption protective layer on the metal surface.

[0051] The oil-soluble poly(meth)acrylate with hydroxyl-terminated ends can be obtained by free radical polymerization of C8-C22 alkyl(meth)acrylate monomers in a system containing a dihydroxyl chain transfer agent or a hydroxyl-initiated system; its terminal hydroxyl groups can be obtained by... 1 Confirmed by H NMR or hydroxyl value testing, the preferred hydroxyl value is 5–30 mg KOH / g.

[0052] Preferably, the carrier base oil includes one or more of API Group III base oils (hydrocracking / hydroisomerization base oils), PAO base oils, alkylated aromatic oils, and polyol esters. Specifically, the alkylated aromatic oils (such as alkylated naphthalene / alkylated benzene) include one or more of C8-C20 alkylated naphthalene oils and C8-C20 alkylated benzene oils; and the polyol esters (such as TMPTO / pentaerythritol esters) include one or more of trimethylolpropane esters and pentaerythritol esters, which are generally also classified as broadly synthetic base oils (API Group V).

[0053] More preferably, in order to improve the stability of the mother liquor during low-temperature storage and transportation and reduce the risk of precipitation, turbidity, and gelation, the mass percentage of alkylated aromatic oil and / or polyol ester (total) in the carrier base oil is preferably 10% to 60%; when the carrier base oil is a low-polarity system (e.g., mainly PAO or high-saturation Group III), it is preferable to introduce not less than 10% of alkylated aromatic oil and / or polyol ester for solubility compensation.

[0054] Preferably, the polymethacrylate pour point depressant is a C8-C18 alkylmethacrylate copolymer with a number average molecular weight of 10,000-50,000, and more preferably a number average molecular weight of 15,000. Preferably, the antifoaming agent includes polyether-modified polysiloxane and polydimethylsiloxane; the polyether-modified polysiloxane is a fluorine-free polyether-modified polysiloxane, that is, a siloxane-based antifoaming agent with polysiloxane as the main chain, containing polyether side chains and without CF bonds. The number average molecular weight of the polyether-modified polysiloxane is 3000-10000, and the content of terminal active functional groups of the polyether-modified polysiloxane is not greater than 0.5%. It exists in parallel with polydimethylsiloxane at a dosage of 20-100 ppm by mass, achieving low foaming and rapid air release within the above-mentioned dosage ranges, while maintaining the interfacial synergistic effect with the phenolic resin-modified polyester demulsifier.

[0055] Preferably, the polydimethylsiloxane is a methyl-terminated or hydroxyl-terminated polydimethylsiloxane, and its kinematic viscosity at 25°C, measured according to ASTM D445, is 1000–30000 mmHg. 2 / s (e.g., 12500 mm) 2 / s), with a number average molecular weight of 5,000 to 30,000 (e.g., 15,000).

[0056] In a preferred embodiment of the present invention, the preparation method of the additive mother liquor for hybrid engine oil specifically includes the following steps: S1. Add 50% to 80% of the carrier base oil to a mixing vessel equipped with a stirring and heating device, heat to about 70°C, add styrene-ethylene / propylene block copolymer viscosity index improver and polymethyl methacrylate pour point depressant, raise the temperature to about 110°C, stir at 300 to 800 r / min for 1 to 4 h until no visible particles are observed and a homogeneous solution is formed. S2. Add polyisobutylene succinic anhydride polyamine ashless dispersant, polyester ashless dispersant and low total base number calcium alkyl salicylate detergent sequentially within the range of 90-110℃, and stir for 30-90 min until uniform. S3. Add zinc dialkyl dithiophosphate and amide ester friction modifier in the same temperature range, and continue stirring for 30-90 min until homogeneous; S4. Cool to approximately 70°C, add hindered phenolic antioxidant, alkylated diphenylamine antioxidant and alkyl succinate rust inhibitor, and mix thoroughly. S5. Cool to about 60°C, add phenolic resin modified polyester demulsifier and boundary lubrication enhancer, and stir for 30-90 minutes until completely homogeneous; S6. Cool down to 45°C, add carrier base oil (excluding that used to dilute the antifoaming agent), and filter (filtration accuracy preferably not greater than 5 microns) to remove any possible polymer gels and solid impurities. S7. At 40-50℃, pre-dilute the fluorine-free polyether-modified polysiloxane and polydimethylsiloxane with the reserved carrier base oil at a mass ratio of 1:5 to 1:20 and slowly add them to the mixture obtained in step S6. Stir at a low speed of 100-300 r / min for 20-60 min to avoid a large amount of air entrainment and obtain a transparent or slightly light-colored stable mother liquor.

[0057] It is understood that the hybrid engine lubricating oil provided by this invention can also be used to monitor its performance status using the three-channel fluorescence diagnostic enhancer disclosed in the invention patent application with application number 202610570553.3.

[0058] The present invention will be further illustrated below through examples. Unless otherwise specified, the materials in the examples can be prepared according to the methods disclosed in this specification, or commercial products that meet the structural and parameter ranges defined in this specification can be selected.

[0059] Example 1 This embodiment provides a hybrid engine oil additive mother liquor. Based on the total mass of the hybrid engine oil additive mother liquor as 100%, except for the antifoaming agent (measured in ppm by mass), the remaining components (measured as a percentage by mass) include: The viscosity index improver for styrene-ethylene / propylene block copolymers is a styrene-ethylene / propylene diblock copolymer with a number average molecular weight of approximately 120,000, a styrene structural unit mass fraction of approximately 5%, and a hydrogenation degree of not less than 95%. The specific chemical is Baling Petrochemical YH-4030, 45%. The polyisobutylene succinic anhydride polyamine ashless dispersant selected is a polyisobutylene succinic anhydride (PIBSA) with a number average molecular weight of 950, prepared by condensation with tetraethylenepentamine. The dispersant is Wuxi Southern Petroleum T154A, 14%. The polyester-type ashless dispersant is a polyisobutylene succinate-based ashless dispersant (PIBSA-pentaerythritol ester) prepared by reacting polyisobutylene succinic anhydride (PIBSA) with pentaerythritol, with a number average molecular weight of 950. Jinzhou Huifa Tianhe T152, 3.5%; The low total base number calcium alkyl salicylate detergent selected was a calcium alkyl salicylate detergent with a total base number of 64 mg KOH / g as measured according to ASTM D2896, Lanzhou Additive T109A, 4.5%; Dialkyl dithiophosphate zinc, selected from C3-C8 primary / secondary alkyl dialkyl dithiophosphate zinc, Kangtai T203, 5%; The amide ester type friction modifier uses N-(2-hydroxyethyl)-N-(2-fatty acyl oxyethyl) fatty amide, with a fatty acyl group of C16 to C18, such as Zschimmer & Schwarz LUBRICIT 2-EHC16 (2%) from Germany. The hindered phenolic antioxidant selected was 2,6-di-tert-butyl-4-methylphenol, Shanghai Keying Chemical T501, 1.4%; Alkylated diphenylamine antioxidants are selected from N,N'-di(nonyl / dodecyl)diphenylamine mixtures (nonyl to dodecyl mass ratio approximately 1:1), Luoyang Xipeng T534, 4%; The alkyl succinate rust inhibitor selected is a C12-C18 monoalkyl succinate half-ester rust inhibitor, Clariant Genapur ASA, 0.9%; The phenolic resin modified polyester demulsifier selected is an alkylphenolic resin modified fatty acid polyester demulsifier that does not contain oxidized olefin segments (e.g., does not contain EO / PO segments), has a hydrophilic-lipophilic balance (HLB) of 4-6 calculated by the Davis method, and a number average molecular weight of 1500-3000, such as Lubrizol LZ859, 0.3%; The polymethyl methacrylate pour point depressant is a C8-C18 alkyl methacrylate copolymer with a number average molecular weight of approximately 15,000, Jinzhou Shengda V-248, 0.5%; Oil-soluble poly(meth)acrylate boundary lubricant enhancer with hydroxyl-terminated ends, number average molecular weight 5000-20000, hydroxyl value 5-30 mg KOH / g, Hebei Tuofu Technology TF-075, 0.4%; The polyether-modified polysiloxane is selected from polyether-modified polysiloxanes with a fluorine-free structure, a number average molecular weight of 3000-10000, and a terminal active functional group content of no more than 0.5%, such as Ningbo Runhe BD3071, 150 ppm by mass. The polydimethylsiloxane used has a kinematic viscosity of approximately 12,500 mmHg at 25°C. 2 / s, polydimethylsiloxane with a number average molecular weight of approximately 15,000, Anhui Aiyueta IOTA 12500, 60 ppm by mass; The balance is carrier base oil, which comprises carrier base oil in a mass ratio of 1:1:1:1: The API Group III base oil (4 cSt) selected is Maoming Petrochemical HVI III 4 cSt; PAO 4 (4cSt) was selected from Zhengmao Petrochemical's PAO 4; Alkylated naphthalene oil was selected from Shanghai Nake AN5; Trimethylolpropane trioleate (TMPTO) was selected from Cangzhou Zhongke Oils & Fats TMPTO-demulsifiable type.

[0060] The preparation process of the additive mother liquor for hybrid engine oil is as follows: S1. Add 80% carrier base oil to a mixing vessel equipped with a stirring and heating device, heat to about 70°C, add styrene-ethylene / propylene block copolymer viscosity index improver and polymethyl methacrylate pour point depressant, heat to about 110°C, stir at 300 r / min for 90 min, until no visible particles are observed and a homogeneous solution is formed. S2. Add polyisobutylene succinic anhydride polyamine ashless dispersant, polyester ashless dispersant and low total base number calcium alkyl salicylate detergent sequentially at 110℃, and stir for 90 min until uniform. S3. Add zinc dialkyl dithiophosphate and amide ester friction modifier in the same temperature range, and continue stirring for 90 min until homogeneous; S4. Cool to approximately 70°C, add hindered phenolic antioxidant, alkylated diphenylamine antioxidant and alkyl succinate rust inhibitor, and mix thoroughly. S5. Cool to about 60°C, add phenolic resin modified polyester demulsifier and boundary lubrication enhancer, and stir for 90 min until completely homogeneous; S6. Cool down to 45°C, add carrier base oil (excluding the one used to dilute the antifoaming agent), and filter with a filter + filter bag with a filtration accuracy of 5 microns to remove any possible polymer gels and solid impurities. S7. At 45°C, the polyether-modified polysiloxane and polydimethylsiloxane without fluorine structure are pre-diluted with the reserved carrier base oil and then slowly added to the mixture obtained in step S6. The mixture is stirred at a low speed of 100 r / min for 60 min to avoid a large amount of air entrainment, resulting in a transparent or slightly light-colored stable mother liquor. After the mother liquor is cooled to room temperature, it is allowed to stand at 25°C for 24 h without visible layering, precipitation or flocculation.

[0061] Example 2 This embodiment provides a hybrid engine oil additive mother liquor, which differs from Embodiment 1 in that: based on the total mass of the hybrid engine oil additive mother liquor as 100%, except for the antifoaming agent (in ppm by mass), the specifications of the raw materials, the composition of the carrier base oil, and the preparation method are the same as in Embodiment 1. The remaining components, in ppm by mass, include: 35% viscosity index improver for styrene-ethylene / propylene block copolymers; 18% polyisobutylene-based succinic anhydride polyamine ashless dispersant; 2% polyester-type ashless dispersant; Low total base number calcium alkyl salicylate detergent 6%; Zinc dialkyl dithiophosphate 3.5%; 3% of amide ester type friction modifiers; Hindered phenolic antioxidants 0.8%; Alkylated diphenylamine antioxidant 5%; Alkyl succinate rust inhibitor 0.3%; Phenolic resin modified polyester demulsifier 0.4%; Polymethyl methacrylate pour point depressant 0.5%; 0.6% of an oil-soluble poly(meth)acrylate boundary lubricant with hydroxyl-terminated ends; Polyether-modified polysiloxane 50 ppm by mass; Polydimethylsiloxane 100 ppm by mass; The remainder is carrier base oil.

[0062] Example 3 This embodiment provides a hybrid engine oil additive mother liquor, which differs from Embodiment 1 in that: based on the total mass of the hybrid engine oil additive mother liquor as 100%, except for the antifoaming agent (in ppm by mass), the specifications of the raw materials, the composition of the carrier base oil, and the preparation method are the same as in Embodiment 1. The remaining components, in ppm by mass, include: 55% viscosity index improver for styrene-ethylene / propylene block copolymers; 10% polyisobutylene-based succinic anhydride polyamine ashless dispersant; 5% polyester-type ashless dispersant; Low total base number calcium alkyl salicylate detergent 3%; Zinc dialkyl dithiophosphate 6%; 1% amide ester type friction modifier; Hindered phenolic antioxidants 2%; Alkylated diphenylamine antioxidant 2.5%; Alkyl succinate rust inhibitor 1.5%; Phenolic resin modified polyester demulsifier 0.1%; Polymethyl methacrylate pour point depressant 0.4%; 0.1% oil-soluble poly(meth)acrylate boundary lubricant with hydroxyl-terminated ends; Polyether-modified polysiloxane 200 ppm by mass; Polydimethylsiloxane 20 ppm by mass; The remainder is carrier base oil.

[0063] Comparative Example 1 This comparative example provides a hybrid engine oil additive mother liquor, which differs from Example 1 in that: based on the total mass of the hybrid engine oil additive mother liquor as 100%, except for the antifoaming agent (in ppm by mass), the specifications of the raw materials, the composition of the carrier base oil, and the preparation method are the same as in Example 1. The remaining components, in ppm by mass, include: 58% viscosity index improver for styrene-ethylene / propylene block copolymers; 8% of polyisobutylene-based succinic anhydride polyamine ashless dispersants; 6% polyester-type ashless dispersant; Low total base number calcium alkyl salicylate detergent 2%; 7% of zinc dialkyl dithiophosphate; Amide ester type friction modifier 0.5%; Hindered phenolic antioxidants 3%; Alkylated diphenylamine antioxidant 1%; Alkyl succinate rust inhibitor 2.5%; Phenolic resin modified polyester demulsifier 0.3%; Polymethyl methacrylate pour point depressant 0.5%; 0.4% of an oil-soluble poly(meth)acrylate boundary lubricant with hydroxyl-terminated ends; Polyether-modified polysiloxane 250 ppm; Polydimethylsiloxane 10 ppm; The remainder is carrier base oil.

[0064] Comparative Example 2 This comparative example provides a hybrid engine oil additive mother liquor, which differs from Example 1 in that: based on the total mass of the hybrid engine oil additive mother liquor as 100%, except for the antifoaming agent (in ppm by mass), the specifications of the raw materials, the composition of the carrier base oil, and the preparation method are the same as in Example 1. The remaining components, in ppm by mass, include: 30% viscosity index improver for styrene-ethylene / propylene block copolymers; 20% polyisobutylene-based succinic anhydride polyamine ashless dispersant; 1% polyester-type ashless dispersant; Low total base number calcium alkyl salicylate detergent 7%; 3% of zinc dialkyl dithiophosphate; 4% of amide ester type friction modifiers; Hindered phenolic antioxidants 0.5%; Alkylated diphenylamine antioxidant 6%; Alkyl succinate rust inhibitor 0.1%; Phenolic resin modified polyester demulsifier 0.6%; Polymethyl methacrylate pour point depressant 0.5%; 1% of oil-soluble poly(meth)acrylate boundary lubricant with hydroxyl-terminated ends; Polyether-modified polysiloxane 40 ppm; Polydimethylsiloxane 150 ppm; The remainder is carrier base oil.

[0065] Comparative Example 3 This comparative example provides a hybrid engine oil additive mother liquor, which differs from Example 1 in that it does not contain pour point depressants and is supplemented with an equal amount of carrier base oil. The specifications of other raw materials, the composition of the carrier base oil, and the preparation method are the same as in Example 1.

[0066] Comparative Example 4 This comparative example provides a hybrid engine oil additive mother liquor, which differs from Example 1 in that it does not contain polyether-modified polysiloxane and is supplemented with an equal amount of carrier base oil. The specifications of other raw materials, the composition of the carrier base oil, and the preparation method are the same as those in Example 1.

[0067] Comparative Example 5 The difference between this comparative example and Example 1 is that the polydimethylsiloxane used has a kinematic viscosity of 100,000 mmHg at 25°C. 2 The raw materials, carrier base oil composition, and preparation method are the same as in Example 1, consisting of polydimethylsiloxane with a number average molecular weight of 40,000 and s.

[0068] Comparative Example 6 The difference between this comparative example and Example 1 is that the non-fluorinated polyether modified polysiloxane in Example 1 is replaced with an equal mass of fluorinated polyether modified polysiloxane, while the specifications of other raw materials, the composition of the carrier base oil, and the preparation method are the same as in Example 1.

[0069] Comparative Example 7 The difference between this comparative example and Example 1 is that an equal mass of highly hydrophilic silicone polyether is used instead of the fluorine-free polyether-modified polysiloxane in Example 1 (e.g., containing a high proportion of EO / PO segments, a hydrophilic-lipophilic balance (HLB) of approximately 10 calculated by the Davis method, a number-average molecular weight of approximately 6000, and a terminal active functional group content of 0.8%). This does not meet the limitation of the present invention that the terminal active functional group content of the polyether-modified polysiloxane should not exceed 0.5%. The remaining raw material specifications, carrier base oil composition, and preparation method are the same as in Example 1.

[0070] Comparative Example 8 This comparative example provides a hybrid engine oil additive mother liquor, which differs from Example 1 in that it does not contain boundary lubrication enhancer and is supplemented with an equal mass of carrier base oil. The specifications of other raw materials, the composition of the carrier base oil, and the preparation method are the same as those in Example 1.

[0071] Comparative Example 9 This comparative example provides a hybrid engine oil additive mother liquor, which differs from Example 1 in that: an equal mass of magnesium alkyl salicylate detergent is used instead of the low total base number calcium alkyl salicylate detergent in Example 1; an equal mass of molybdenum dialkyl dithiocarbamate is used instead of the amide ester friction modifier in Example 1; and 210 ppm of fluorinated silicone polyether antifoaming agent is used instead of the 150 ppm of fluorine-free polyether-modified polysiloxane and 60 ppm of polydimethylsiloxane parallel antifoaming system in Example 1. The remaining raw material specifications, carrier base oil composition, and preparation method are the same as in Example 1.

[0072] Comparative Example 10 This comparative example provides a hybrid engine oil additive mother liquor, which differs from Example 1 in that: an emulsifier with an equal mass of olefin oxide as the main component replaces the phenolic resin modified polyester demulsifier in Example 1, while the specifications of other raw materials, the composition of the carrier base oil, and the preparation method are the same as in Example 1.

[0073] Application Example 1 This application example provides a hybrid engine lubricant. Based on 100% of the total mass of the hybrid engine lubricant, its components, by mass percentage, include 20% of the hybrid engine oil additive mother liquor prepared in Example 1 and the balance being a lubricating base oil. The lubricating base oil comprises: API Group III base oil (4 cSt, kinematic viscosity approximately 4 mmHg at 100°C) in a mass ratio of 1:1:1:1. 2 The mixture consists of PAO 4 cSt, alkylated naphthalene oil, and trimethylolpropane trioleate. The preparation process involves adding the mother liquor to the lubricating base oil at a mass percentage of 20% to obtain the hybrid engine lubricating oil.

[0074] Application Example 2 This application example provides a hybrid engine lubricating oil, which differs from Application Example 1 in that it uses the hybrid engine oil additive mother liquor prepared in Example 2.

[0075] Application Example 3 This application example provides a hybrid engine lubricating oil, which differs from Application Example 1 in that it uses the hybrid engine oil additive mother liquor prepared in Example 3.

[0076] Comparative Application Example 1 This comparative application example provides a hybrid engine lubricating oil, which differs from Application Example 1 in that it uses the hybrid engine oil additive mother liquor prepared in Comparative Example 1.

[0077] Comparative Application Example 2 This comparative application example provides a hybrid engine lubricating oil, which differs from application example 1 in that it uses the hybrid engine oil additive mother liquor prepared in comparative example 2.

[0078] Comparative Application Example 3 This comparative application example provides a hybrid engine lubricating oil, which differs from application example 1 in that it uses the hybrid engine oil additive mother liquor prepared in comparative example 3.

[0079] Comparative Application Example 4 This comparative application example provides a hybrid engine lubricating oil, which differs from application example 1 in that it uses the hybrid engine oil additive mother liquor prepared in comparative example 4.

[0080] Comparative Application Example 5 This comparative application example provides a hybrid engine lubricating oil, which differs from application example 1 in that it uses the hybrid engine oil additive mother liquor prepared in comparative example 5.

[0081] Comparative Application Example 6 This comparative application example provides a hybrid engine lubricating oil, which differs from application example 1 in that it uses the hybrid engine oil additive mother liquor prepared in comparative example 6.

[0082] Comparative Application Example 7 This comparative application example provides a hybrid engine lubricating oil, which differs from application example 1 in that it uses the hybrid engine oil additive mother liquor prepared in comparative example 7.

[0083] Comparative Application Example 8 This comparative application example provides a hybrid engine lubricating oil, which differs from application example 1 in that it uses the hybrid engine oil additive mother liquor prepared in comparative example 8.

[0084] Comparative Application Example 9 This comparative application example provides a hybrid engine lubricating oil, which differs from application example 1 in that it uses the hybrid engine oil additive mother liquor prepared in comparative example 9.

[0085] Comparative Application Example 10 This comparative application example provides a hybrid engine lubricating oil, which differs from Application Example 1 in that it uses the hybrid engine oil additive mother liquor prepared in Comparative Example 10.

[0086] Comparative Application Example 11 This comparative application example provides a hybrid engine lubricating oil, which differs from Application Example 1 in that its components include 15% of the hybrid engine oil additive mother liquor prepared in Example 1 and the balance being lubricating base oil.

[0087] Comparative Application Example 12 This comparative application example provides a hybrid engine lubricating oil, which differs from Application Example 1 in that its components include 10% of the hybrid engine oil additive mother liquor prepared in Example 1 and the balance being lubricating base oil.

[0088] Test case Test methods: Demulsification was determined according to ASTM D1401 at 54°C to achieve a separation time of 40-40-0, where 40-40-0 represents the volume of the oil layer-water layer-emulsion layer; foaming was determined according to ASTM D892 to measure the foaming / defoaming volume of the I, II, and III sequences; air release was determined according to ASTM D3427 at 50°C; boundary lubrication and wear resistance were determined according to ASTM D4172 at 75°C, 1200 r / min, 392 N, and 60 min, with the wear scar diameter being the average of the diameters of the three test ball wear scars.

[0089] Table 1. Overall Performance of Lubricating Oil for Hybrid Engines

[0090] Table Notes: 1. Demulsification was determined according to ASTM D1401 at a test temperature of 54°C, and the separation time to reach 40-40-0 was recorded.

[0091] 2. Foam was measured according to ASTM D892. Foam I, Foam II, and Foam III correspond to the results of the I, II, and III sequences, respectively. The results are expressed as foaming / defoaming volume in mL.

[0092] 3. Gas release shall be determined according to ASTM D3427, at a test temperature of 50°C, in minutes.

[0093] 4. Wear scars were measured according to ASTM D4172 at 75°C, 1200 r / min, 392 N, and 60 min, and the unit is mm.

[0094] As shown in Table 1, Application Example 1 achieves a relatively balanced combination of comprehensive performance in terms of demulsification, foaming, air release, and boundary lubrication and anti-wear: demulsification time is 6 min, foam I, foam II, and foam III are all 0 / 0, air release time is 2.0 min, and wear scar diameter is 0.38 mm. Application Examples 2-3 maintain stable performance at the same order of magnitude in key indicators, indicating that the mother liquor composition and process parameters defined in this invention have good feasibility and adaptability to operating conditions.

[0095] When the formulation is further adjusted or key components are replaced, the overall margin for demulsification time, foam, air release, and anti-wear performance decreases, or at least one of them deteriorates to varying degrees. For example, when the key structural parameters of the antifoaming / degassing system are changed or a highly hydrophilic system is used, the demulsification time increases, the foam sequence increases, and the degassing time is prolonged; when the amount of mother liquor added is reduced from 20% to 15% or 10%, the demulsification time increases accordingly, the foam sequence increases, the degassing time is prolonged, and the wear scar diameter increases; when the boundary lubrication enhancer is removed, the wear scar diameter increases significantly; when an olefin-based demulsifier is used to replace the phenolic resin modified polyester demulsifier of this invention that does not contain olefin segments, the demulsification, foam, and air release indicators also deteriorate significantly.

[0096] Comparative application example 9 shows that although multi-factor composite replacement can result in a lower wear scar diameter in local wear resistance indicators, it also leads to prolonged demulsification time, significantly increased foam, and worsened air release, indicating that multi-metal / fluorine composite replacement will lead to an imbalance in overall performance.

[0097] The above results indicate that by synergistically limiting the structure and dosage windows of the low total base calcium alkyl salicylate, demulsifier, siloxane system and boundary lubrication enhancement system, the present invention helps to obtain a more stable combination of comprehensive performance under the constraints of low ash and mixed operating conditions.

[0098] To further evaluate the synergistic effect of the key components of this invention, comparative experiments can be set up using the single-factor substitution principle and the contamination challenge principle. The single-factor substitution principle refers to replacing only the demulsifier system, antifoaming / gas release system, detergent system, boundary lubrication enhancer, or mother liquor amount, while keeping the composition, amount, base oil composition, and mother liquor amount of all components except the component under investigation constant. The contamination challenge principle refers to introducing water and / or fuel contaminants into the finished oil in addition to a clean oil sample to evaluate the demulsification performance, foaming characteristics, air release, rust / corrosion prevention performance, and boundary lubrication anti-wear performance under hybrid operating conditions. The corresponding experimental design and evaluation items are shown in Tables 2-4.

[0099] Table 2. Single-factor design and evaluation items

[0100] Table 3. Pollution Challenge Conditions and Assessment Items

[0101] In Table 3, water is deionized water and gasoline is automotive gasoline; the amount of water and gasoline added are calculated according to the mass fraction of the finished oil. The preparation method of the pollution challenge sample is as follows: after adding water and / or gasoline according to Table 3, stir at 1000 r / min for 10 min at 25℃, let stand for 30 min, and then perform the corresponding test.

[0102] Table 4. Evaluation Methods and Judgment Criteria

[0103] Furthermore, in some embodiments, by adjusting the type and ratio of the lubricating base oil, the mother liquor of the present invention can be added to the compatible base oil system at a dosage of 20%, thereby formulating hybrid engine lubricating oils of different viscosity grades. The formulation of these different viscosity grades should be carried out under the mother liquor addition amount, base oil compatibility, and finished oil performance testing standards disclosed in this application. This indicates that the mother liquor of the present invention has the potential to be adapted as a platform mother liquor for multi-viscosity grade hybrid engine lubricating oils.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A masterbatch for additives in hybrid engine oil, characterized in that, Based on the total mass of the additive mother liquor, except for the amount of antifoaming agent expressed in ppm by mass, the remaining components are expressed as a percentage by mass. The additive mother liquor includes the following components: Viscosity index improver 35%-55%, wherein the viscosity index improver includes styrene-ethylene / propylene block copolymer viscosity index improver, wherein the styrene-ethylene / propylene block copolymer viscosity index improver includes styrene-ethylene / propylene diblock copolymer, and wherein the number average molecular weight of the styrene-ethylene / propylene block copolymer viscosity index improver is 80,000-200,000; 10%-18% polyisobutylene-based succinic anhydride polyamine ashless dispersant; Polyester-based ashless dispersant 2%-5%; Low total base number calcium alkyl salicylate detergent 3%-6%, with a total base number of 30-80 mgKOH / g as measured by ASTM D2896; Zinc dialkyl dithiophosphate 3.5%-6%; Amide ester type friction modifiers 1%-3%; Hindered phenolic antioxidants: 0.8%-2%; Alkylated diphenylamine antioxidant 2.5%-5%; Alkyl succinate rust inhibitor 0.3%-1.5%; The phenolic resin modified polyester demulsifier is 0.1%-0.4%, wherein the phenolic resin modified polyester demulsifier does not contain oxidized olefin segments, has a hydrophilic-lipophilic balance value of 4-6 calculated by the Davies method, and has a number average molecular weight of 1500-3000. Boundary lubrication enhancer 0.1%-0.6%, wherein the boundary lubrication enhancer is an oil-soluble poly(meth)acrylate with hydroxyl ends capped at both ends, and the number average molecular weight of the boundary lubrication enhancer, measured by gel permeation chromatography with polystyrene as a standard, is 5000-20000. Polymethyl methacrylate pour point depressant 0.1%-1%; 50-200 ppm of fluorine-free polyether-modified polysiloxanes with a number average molecular weight of 3000-10000, according to... 1 The content of terminal active functional groups, as determined by H NMR or chemical titration, is no more than 0.5%; Polydimethylsiloxane, 20-100 ppm, has a kinematic viscosity of 1000-30000 mm at 25°C. 2 / s; The remainder is carrier base oil; The additive mother liquor contains no magnesium-based detergents, no molybdenum-containing compounds, no demulsifiers mainly composed of ethylene oxide block structures, propylene oxide block structures, or ethoxylated alcohol structures, and no fluorinated silicone polyether antifoaming agents.

2. The additive mother liquor for hybrid engine oil according to claim 1, characterized in that, The carrier base oil includes one or more of API Group III base oil, PAO base oil, alkylated aromatic oil and polyol ester, and the total content of the alkylated aromatic oil and / or polyol ester in the carrier base oil is 10%-60%.

3. A method for preparing a mother liquor for a hybrid engine oil as described in claim 1 or 2, characterized in that, Includes the following steps: (a) Mix a portion of the carrier base oil with the styrene-ethylene / propylene block copolymer viscosity index improver and polymethyl methacrylate pour point depressant, and heat and stir until a homogeneous solution is formed; (b) Add polyisobutylene succinic anhydride polyamine ashless dispersant, polyester ashless dispersant, low total base number calcium alkyl salicylate detergent, dialkyl dithiophosphate zinc and amide ester friction modifier, and mix evenly; (c) Add hindered phenolic antioxidants, alkylated diphenylamine antioxidants, alkyl succinate rust inhibitors, phenolic resin modified polyester demulsifiers and boundary lubrication enhancers, and mix thoroughly; (d) Replenish the carrier base oil (excluding that used to dilute the antifoaming agent) and filter it; (e) The polyether-modified polysiloxane without fluorine structure and the polydimethylsiloxane are pre-diluted with reserved carrier base oil and added to the mixture obtained in step (d), and mixed at low speed to obtain the homogeneous and stable additive mother liquor for hybrid engine oil.

4. The preparation method according to claim 3, characterized in that, The processing temperature in step (a) is 70-110℃; Preferably, the processing temperature in step (b) is 90-110°C; Preferably, the treatment temperature when adding hindered phenolic antioxidants, alkylated diphenylamine antioxidants and alkyl succinate rust inhibitors in step (c) is 68-75°C, and the treatment temperature when adding phenolic resin modified polyester demulsifier and boundary lubrication enhancer is 55-65°C. Preferably, the processing temperature in steps (d) and (e) is 40-50°C; Preferably, the filtration accuracy of step (d) is no greater than 5 micrometers.

5. The application of the hybrid engine oil additive mother liquor as described in claim 1 or 2, or the hybrid engine oil additive mother liquor prepared by the preparation method described in claim 3 or 4, in the preparation of hybrid engine lubricating oil, characterized in that, The additive mother liquor for hybrid engine oil is added to the lubricating base oil at 20% of the total mass of the hybrid engine lubricating oil for blending.

6. A hybrid engine lubricating oil, characterized in that, The hybrid engine lubricating oil is formulated from a lubricating base oil and the hybrid engine oil additive mother liquor as described in claim 1 or 2, or the hybrid engine oil additive mother liquor prepared by the preparation method described in claim 3 or 4, wherein the hybrid engine oil additive mother liquor accounts for 20% of the total mass of the hybrid engine lubricating oil.

7. The hybrid engine lubricating oil according to claim 6, characterized in that, The lubricating base oil includes one or more of API Group III base oil, PAO 4 cSt, alkylated naphthalene oil, and trimethylolpropane trioleate.

8. The hybrid engine lubricating oil according to claim 6 or 7, characterized in that, According to ASTM D1401, the demulsification time to reach 40-40-0 at 54℃ should not exceed 8 min; according to ASTM D892, the foam volume (foaming / defoaming) of the I / II / III series should be 0 / 0 mL / mL; according to ASTM D3427, the air release time at 50℃ should not exceed 2.4 min; according to ASTM D4172, the wear scar diameter should not exceed 0.41 mm under the conditions of 75℃, 1200 r / min, 392 N, and 60 min.

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