Ultralow-viscosity lubricating oil composition and preparation method thereof

Abstract

The invention relates to the technical field of lubricating oil, in particular to an ultralow-viscosity lubricating oil composition and a preparation method thereof. The lubricating oil is especially suitable for cooling and lubricating an electric driving system of an electric automobile. The composition adopts poly-alpha-olefin (mPAO) prepared by catalyzing C-Calpha-olefin by a metallocene main catalyst taking Ti as a metal center as main base oil, and has the characteristics of regular structure, narrow molecular weight distribution, rich branched chains and the like. The kinematic viscosity of the base oil is 0.9366-3.0393 mm < 2 > / s (100 DEG C), the pour point is lower than-60 DEG C, the heat-conducting property is excellent, the volatilization loss is low, and the lubricating oil composition is endowed with good low-temperature startability, heat conductivity, shear stability and electrical insulating property. And high-VI and long-acting lubrication can be realized without adding a high-molecular viscosity index improver, and the lubricating oil is suitable for a high-load and high-rotating-speed electric drive system.

Description

Technical Field

[0001] The present application relates to the technical field of lubricating oils, and more particularly, to an ultra-low viscosity lubricating oil composition and a preparation method thereof. Background Art

[0002] The evolution of international standards for reducing CO2 emissions and energy consumption has forced automakers to come up with alternatives to internal combustion engines. One of the solutions identified by automakers is replacing internal combustion engines with electric motors, and research into reducing CO2 emissions has led a number of automakers to develop electric vehicles.

[0003] Electric vehicles (EVs), including battery electric vehicles (BEVs), hybrid vehicles (HVs), and plug-in hybrid vehicles (PHVs), which have electric motors and / or generators built into their powertrains, present unique challenges to the lubrication industry.

[0004] Lubricating oil compositions are composed of one or more base oils combined with various additives, such as friction modifiers, to enhance the lubricating properties of the base oils.

[0005] Typically, electric and hybrid vehicles require compositions that meet the dual constraints of cooling and lubricating the various drivetrain components. These requirements are met through the use of two distinct approaches: a lubricating composition on the one hand, and a cooling fluid on the other. Consequently, lubricating oil compositions, also known as "lubricants," are commonly used in engines, primarily to reduce friction between the various moving metal parts within the engine. Furthermore, they effectively prevent premature wear and even damage to these components, particularly their surfaces.

[0006] Electric motors generate heat during operation. If the heat generated is greater than the heat normally dissipated into the environment, the engine must be cooled. Compared to high-viscosity lubricants (such as Chinese invention patent CN116904244B), low-viscosity lubricants have better heat dissipation performance. Due to their better fluidity, low-viscosity lubricants can more effectively remove the heat generated by components such as motors and gears, reducing the surface temperature of the motors. This is particularly important for the electric drive systems of electric vehicles, as good heat dissipation can improve the stability and reliability of the system. In addition, low-viscosity lubricants require less energy to flow, which can significantly reduce the churning losses of the drive axle. In electric vehicles, this churning loss may account for 70% of the total loss of the drive axle, so using low-viscosity lubricants can effectively reduce energy loss and improve the operating efficiency of the vehicle.

[0007] Traditional engine oils with viscosity grades of SAE 0W-16 and above are prone to stagnation at temperatures below -40°C, causing a sudden increase in pumping power and delayed oil supply to bearings when starting. However, some ultra-low viscosity oils (≤3mm 2 / s@100℃) has a low pour point, but due to the lack of branched or cyclic "support" in the molecular structure of the base oil, wax crystal growth and stagnation are prone to occur in extremely cold environments, exacerbating cold start wear. In addition, the Joule heat and viscous heat of the tooth surface generated instantaneously by EV reducers and permanent magnet synchronous motors at high speeds (>20,000r / min) need to be quickly removed by the oil. The thermal conductivity of mineral-based or conventional cPAO base oils is usually between 0.155–0.170W / (m·K), which makes it difficult to meet the heat exchange requirements of the "oil cooling-spray" mode of high-power density electric drive systems, resulting in excessive local temperature rise, increased risk of magnetic steel demagnetization and insulation aging. In order to achieve a lower viscosity, some formulas tend to introduce low-molecular-weight isoparaffins or light esters. Although this strategy can reduce HTHS viscosity, its Noack evaporation loss at 250°C is often higher than 18wt%, causing oil concentration, viscosity increase, and additive ratio drift in the closed reducer; it may also cause secondary emissions in the crankcase ventilation (PCV) system, affecting the life of the exhaust after-treatment device.

[0008] To this end, existing solutions typically rely on adding high-molecular-weight viscosity index improvers (VIIs) to low-viscosity base oils to enhance high-temperature film strength, or employing polyesters to improve flow and extreme pressure resistance. However, VIIs are susceptible to mechanical degradation in high-shear zones, and esters significantly increase the oil's polarity and water absorption, thereby weakening electrical insulation and shortening service life. Striking a balance between extreme low-temperature pumpability, excellent thermal conductivity, and low evaporation volatility has become a core technical bottleneck that needs to be overcome in the development of next-generation ultra-low viscosity lubricant compositions. Summary of the Invention

[0009] To address the above technical problems, the present application provides an ultra-low viscosity lubricating oil composition, prepared by selectively adding a viscosity index improver and additives to a low-viscosity base oil with excellent low-temperature performance. The resulting lubricating oil composition exhibits low viscosity, excellent low-temperature performance, high thermal conductivity, and low Noack evaporation loss.

[0010] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0011] An ultra-low viscosity lubricating oil composition comprises the following components in percentage by weight:

[0012] a. A first base oil having a kinematic viscosity at 100° C. of 0.9366 to 3.0393 mm² as measured according to ASTM D445. 2 / s and a pour point of not higher than -60°C as measured according to ASTM D97, and a content of 90 to 98% by weight of the composition;

[0013] b. Viscosity regulator, content is 0-5%;

[0014] c. Additives 0-5%;

[0015] The first base oil is poly-α-olefin, which is prepared from α-olefin raw materials in the presence of a metallocene catalyst system consisting of a metallocene main catalyst, an organic borate co-catalyst and a Lewis acid co-catalyst;

[0016] The metallocene catalyst is an organic compound with Ti as the metal center (hereinafter referred to as Metallocene-Ti), and its chemical structure is:

[0017]

[0018] Wherein, A1, A2, and A3 are each independently selected from halogen, a substituted or unsubstituted B group, and the B group includes any one of a C1-C40 alkyl group, a C3-C40 cycloalkyl group, a C2-C40 heterocycloalkyl group, a C6-C60 aryl group, a C4-C60 heteroaryl group, a C7-C60 aralkyl group, and a C6-C60 heteroaralkyl group.

[0019] Preferably, the B group includes any one of a C1-C5 alkyl group, a C3-C10 cycloalkyl group, a C2-C6 heterocycloalkyl group, a C2-C10 unsaturated hydrocarbon group, a C6-C15 aryl group, a C4-C15 heteroaryl group, a C7-C15 aralkyl group, and a C6-C15 heteroaralkyl group.

[0020] Preferably, the preparation method of the first base oil poly-α-olefin is:

[0021] (1) α-olefin as raw material is added to the kettle;

[0022] (2) preparing a metallocene catalyst: uniformly mixing a metallocene primary catalyst, an organic borate cocatalyst, a Lewis acid cocatalyst, and a solvent;

[0023] (3) adding a metallocene catalyst to a kettle, heating and reacting for a period of time to obtain a crude product;

[0024] (4) post-processing the crude product to obtain the poly-α-olefin.

[0025] Preferably, in step (1), the raw α-olefin is added to the reactor, replaced with nitrogen three times, and cooled to 10-15°C.

[0026] Preferably, a metallocene catalyst is added in step (3), stirring is continued for 10-20 min, then the temperature is raised to 20-25 ° C and stirred for 20-30 h.

[0027] Preferably, a quenching solution is added in step (4), and the temperature is raised to 40-60° C. and stirred for 1-3 hours for quenching. After the quenching is completed, the mixture is allowed to stand for 15-30 minutes, cooled to room temperature, separated, the upper layer of the reaction liquid is collected, granular clay is added for filtration, the filtrate is collected and subjected to reduced pressure distillation, and the fractions are collected and hydrogenated.

[0028] Preferably, the organic borate co-catalyst is any one or more boron compounds selected from trityltetrakis(pentafluorophenyl)borate, tri(p-octylphenyl)methyltetrakis(pentafluorophenyl)borate, dimethylphenylammoniumtetrakis(pentafluorophenyl)borate, diethylphenylammoniumtetrakis(pentafluorophenyl)borate, methyldiphenylammoniumtetrakis(pentafluorophenyl)borate, ethyldiphenylammoniumtetrakis(pentafluorophenyl)borate, methyldioctadecylammoniumtetrakis(pentafluorophenyl)borate, and trioctylammoniumtetrakis(pentafluorophenyl)borate. More preferably, the organic borate co-catalyst is N,N-dimethylphenylammoniumtetrakis(pentafluorophenyl)borate.

[0029] Preferably, the Lewis acid co-catalyst is a decane solution of triisobutylaluminum.

[0030] When the base oil polyα-olefin is prepared by the above preparation method, the α-olefin described in the present application is selected from one or more of α-pentene, α-hexene, α-heptene, α-octene, α-nonene and α-decene. The prepared polyα-olefin PAO has a trimer structure of the above α-olefin, and the polyα-olefin is composed of a mixture of compounds represented by the following formulas (I) and (II):

[0031]

[0032] wherein R1 to R6 are each independently a straight-chain C3-C8 alkane.

[0033] Preferably, the lubricating oil composition has a viscosity of 1.5 to 4.0 mm as measured according to ASTM D445. 2 / s at 100°C kinematic viscosity, a pour point not higher than -60°C as measured according to ASTM D97, a thermal conductivity not higher than 0.135 W / (m·K) as measured according to ASTM E1269, and a Noack evaporation loss not higher than 15 wt% as measured according to ASTM D5800.

[0034] Furthermore, the lubricating oil composition of the present application has excellent Noack volatility measured by ASTM D 5800. Preferably, the Noack volatility of the lubricating oil composition is less than 15 wt% loss, preferably, less than 11 wt% loss.

[0035] Furthermore, the kinematic viscosity of the lubricating oil composition of the present application at 100°C is 1.5 to 4.0 mm 2 / s, preferably, the kinematic viscosity at 100°C is 2 to 3 mm 2 / s.

[0036] Furthermore, the viscosity index of the lubricating oil composition described in the present application is not less than 100, preferably, the viscosity index is not less than 110.

[0037] Furthermore, the pour point of the lubricating oil composition described in the present application is not higher than -60°C.

[0038] Furthermore, the thermal conductivity of the lubricating oil composition described in the present application is not higher than 0.135 W / (m·K).

[0039] The viscosity modifiers described herein include viscosity index improvers that can improve the shear stability of the lubricating oil composition, such as polyesters and high molecular weight hydrocarbons with a molecular weight of 1,000-1,000,000; and also include second base oils that can increase the viscosity of the lubricating oil composition, such as API Group IV base oils.

[0040] Preferably, the second base oil is a polyalphaolefin. The polyalphaolefin described herein is a polymer prepared by polymerizing alpha-olefins in the presence of a catalyst system and optionally hydrogenating them to remove residual carbon-carbon double bonds. The polyalphaolefin specifically includes metallocene PAO (mPAO) and conventional non-metallocene PAO (cPAO). The mPAO is prepared using a metallocene catalyst system, while the cPAO is prepared using a conventional non-metallocene catalyst system.

[0041] in,

[0042] The α-olefin is a linear α-olefin composed of monomers with 5 to 10 carbon atoms, which is prepared by low-carbon olefin homopolymerization, high-carbon alcohol dehydration, Fischer-Tropsch process or ethylene oligomerization.

[0043] Preferably, the α-olefin is one or more of α-pentene, α-hexene, α-heptene, α-octene, α-nonene and α-decene.

[0044] The metallocene catalyst system comprises at least one metallocene catalyst, which is an inorganic-organic complex containing at least one cyclopentadienyl or cyclopentadienyl derivative as a ligand and at least one Group IVB transition element as a central atom.

[0045] The non-metallocene catalyst system comprises at least one non-metallocene catalyst, wherein the non-metallocene catalyst comprises: a non-metallocene inorganic-organic complex formed by a ligand without a cyclopentadiene structure and a transition metal or a rare earth metal element, wherein the metal center comprises a transition metal and a rare earth metal element from Group IIIB to Group VIII, coordinated with a ligand containing heteroatoms such as N, O, S, and P, such as an α-diimine metal organic compound, a β-diimine metal organic compound, a β-diketoimine metal organic compound, an amidine metal organic compound, and a P-containing metal organic compound; a homogeneous Lewis acid catalyst catalytic agents, such as AlCl3, AlBr3, TiCl3, SiCl3, BiCl3, FeCl3, BF3 and BF3-ROH; heterogeneous Lewis acid catalysts, composed of the above homogeneous Lewis acid catalysts and inorganic porous substances, wherein the inorganic porous substances are selected from one or more of mesoporous carbon, carbon nanotubes, activated carbon fibers, acetylene black, carbon black, expanded graphite, and graphene; Ziegler-Natta catalysts, composed of Et3Al and TiCl4; chromium-based catalysts, such as chromium oxide, chromium halides, chromium phosphates, sulfates, nitrates, oxalates, etc.,

[0046] Preferably, the metallocene catalyst system consists of a metallocene main catalyst, an organic borate cocatalyst and a Lewis acid cocatalyst.

[0047] Preferably, the viscosity modifier is one or more of API-IV base oil and API-V base oil; preferably one of mPAO40, mPAO150 and alkyl naphthalene.

[0048] Preferably, the additives described herein include, but are not limited to, one or more of antioxidants, detergent dispersants, ashless dispersants, antifoaming agents, and extreme pressure and antiwear agents. These additives may be added individually or in combination.

[0049] Furthermore, the antioxidant is one or more of phenolic antioxidants, phosphite antioxidants and amine antioxidants; the added amount of the antioxidant can be 0.01-5wt%, preferably 0.01-3wt%, more preferably 0.1-2wt%.

[0050] Wherein, the phenolic antioxidant is selected from 2,4-di-tert-butylphenol, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate n-octadecyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl) propionate, )benzene, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, triethylene glycol-bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, 4,4'-thiobis(6-tert-butyl-3-methylphenol), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid isooctyl ester, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 2,2'-thiodiethylbis (3-(3,5-di-tert-butyl-4-hydroxyphenyl) acrylic acid) one or more; the phosphite antioxidant is selected from tris-nonylphenol phosphite, tris[2,4-di-tert-butylphenyl] phosphite, bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, 2,2'-ethylenebis(4,6-di-tert-butylphenyl) fluorophosphite, carbonyl-4,4'-diisopropyl-fatty alcohol-phosphite, diphenyl monoisodecyl phosphite, phosphorous acid The antioxidant is selected from the group consisting of triethyl phosphite, tributyl phosphite, and trioctyl phosphite; the amine antioxidant is selected from the group consisting of diphenylamine, hydroxylamine, N,N'-diaryl-p-phenylenediamine, N,N'-diarylbutyl-p-phenylenediamine, N-aryl-N'-alkyl-p-phenylenediamine, 3,5-diethyltoluenediamine, N-phenylnaphthylamine, N,N'-dialkyl-p-phenylenediamine, dialkyldiphenylamine, diaminotoluene and its derivatives, 1,8-diaminonaphthalene and its derivatives.

[0051] Preferably, the antioxidant is antioxidant TH-1135, whose chemical name is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate.

[0052] Furthermore, the detergent dispersant is a polyisobutylenyl succinimide derivative, selected from one or more of monoalkenyl succinimide, polyisobutylenyl succinimide, polyisobutylene polysuccinimide and boronated polysuccinimide.

[0053] Preferably, the detergent dispersant is T154A or T154B, wherein T154A is polyisobutylene succinimide and T154B is boronated polysuccinimide.

[0054] Furthermore, the ashless dispersant is ADDITINRC 8210 or ADDITINRC 8213, whose chemical components are thiadiazole derivatives.

[0055] Furthermore, the anti-foaming agent is one or more of silicone oil, fluorosilicone oil and other silicone series, and ether series such as fluoroalkyl ether and other ether series.

[0056] Preferably, the anti-foaming agent is Xinxing No. 1 composite anti-foaming agent, the chemical composition of which is a compound of polydimethylsiloxane and alkyl acrylate polymer.

[0057] Furthermore, the extreme pressure anti-wear agent is one or more of sulfided olefins, disulfide aromatic hydrocarbons, sulfided oils and fats, thiophosphates, alkyl phosphates, sulfur and phosphorus nitrogen derivatives and thiophosphate complex ester amine salts.

[0058] Preferably, the extreme pressure anti-wear agent is T304, Irgalube TPPT or Irgalube 353, wherein T304 is dibutyl phosphite, Irgalube TPPT is triphenylthiophosphate, and Irgalube 353 is dithiophosphate.

[0059] The present invention adopts the above technical solution and adopts a metallocene main catalyst system with Ti as the metal center, by precisely controlling the C5-C 10 The trimerization reaction of α-olefins produces a poly-α-olefin (mPAO) base oil with a regular structure, narrow distribution, and clear branching structure, which is then formulated into a lubricating oil composition with ultra-low viscosity and high performance. The low-viscosity base oil prepared in this application has excellent low-temperature performance, lubricating and friction-reducing ability, and shear stability. Compared with products formulated with commercially available base oils, lubricants formulated with this base oil have better high- and low-temperature performance, higher oxidation stability, anti-wear performance, and mechanical shear stability, and have lower evaporation loss. The comprehensive indicators are far superior to commercially available products. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a high temperature GC chart of the product in Preparation Example 2 of this application;

[0061] Figure 2 This is a high temperature GC chart of the product in Preparation Example 3 of this application;

[0062] Figure 3 This is a high temperature GC chart of the product in Preparation Example 4 of this application;

[0063] Figure 4 This is a high temperature GC chart of the product in Preparation Example 5 of this application;

[0064] Figure 5 This is a relationship diagram between different sliding-rolling ratios and traction coefficients of mAPO2.5 prepared in Example 4 of this application and PAO2.5 prepared in Comparative Preparation Example 2;

[0065] Figure 6This is a graph showing the relationship between different rates and traction coefficients for mAPO2.5 prepared in Example 4 of this application and PAO2.5 prepared in Comparative Example 2;

[0066] Figure 7 This is a relationship diagram between different sliding-rolling ratios and traction coefficients of mPAO3 in Preparation Example 5 of this application and PAO3 in Comparative Preparation Example 3;

[0067] Figure 8 This is a relationship diagram between different rates and traction coefficients of mPAO3 in Preparation Example 5 of this application and PAO3 formulated in Comparative Preparation Example 3. DETAILED DESCRIPTION

[0068] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0069] Preparation Example: Polyalphaolefin Base Oil

[0070] Table 1 below shows the properties of the raw materials used in Preparation Examples 1-4.

[0071] Table 1

[0072]

[0073] Preparation Example 1

[0074] (1) Raw materials were added to the kettle: 37.0 kg C5H 10 Add to a 150L reactor, replace with nitrogen three times, and cool to 10-15°C;

[0075] (2) Preparation of metallocene catalyst: 31.8 g of metallocene catalyst, 32.0 g of 4PHB-N, and 150 g of o-difluorobenzene were added to a batching kettle, stirred until clear, and set aside;

[0076] (3) 2.3 kg Al i Add Bu3 to the reactor in (1), stir for 10-20 minutes, then add the metallocene catalyst prepared in (2) at one time, continue stirring for 10-20 minutes, then heat to 20-25°C and stir for 24 hours;

[0077] (4) After the reaction is completed, 1.5 kg of 30% sodium hydroxide solution is added, and the temperature is raised to 50° C. and stirred for 2 h to quench. After the quenching is completed, the mixture is allowed to stand for 15-30 min, cooled to room temperature, and separated. The upper layer of the reaction liquid is collected, 370 g of granular clay is added, filtered, and the filtrate is collected and distilled under reduced pressure. The fractions are collected and hydrogenated to obtain the product mPAO1, and its kinematic viscosity at 100° C. is 0.9366 mm 2 / s.

[0078] Preparation Example 2

[0079] (1) Raw materials were added to the kettle: 37.0 kg C6H 12 Add to a 150L reactor, replace with nitrogen three times, and cool to 10-15°C;

[0080] (2) Preparation of metallocene catalyst: Add 31.0 g of metallocene catalyst, 31.5 g of 4PHB-N, and 150 g of o-difluorobenzene into a batching kettle, stir until clear, and set aside;

[0081] (3) 2.2 kg Al i Add Bu3 to the reactor in (1), stir for 10-20 minutes, then add the metallocene catalyst prepared in (2) at one time, continue stirring for 10-20 minutes, then heat to 20-25°C and stir for 24 hours;

[0082] (4) After the reaction is completed, 1.5 kg of 30% sodium hydroxide solution is added, and the temperature is raised to 50° C. and stirred for 2 h to quench. After the quenching is completed, the mixture is allowed to stand for 15-30 min, cooled to room temperature, and separated. The upper layer of the reaction liquid is collected, 370 g of granular clay is added, filtered, and the filtrate is collected and distilled under reduced pressure. The fractions are collected and hydrogenated to obtain the product mPAO1.3, whose kinematic viscosity at 100° C. is 1.3310 mm 2 / s, high temperature GC see attached Figure 1 .

[0083] Preparation Example 3

[0084] (1) Raw materials were added to the kettle: 37.0 kg C7H 14 Add to a 150L reactor, replace with nitrogen three times, and cool to 10-15°C;

[0085] (2) Preparation of metallocene catalyst: Add 30.0 g of metallocene catalyst, 31.1 g of 4PHB-N, and 150 g of o-difluorobenzene into a batching kettle, stir until clear, and set aside;

[0086] (3) 2.1 kg Al iAdd Bu3 to the reactor in (1), stir for 10-20 minutes, then add the metallocene catalyst prepared in (2) at one time, continue stirring for 10-20 minutes, then heat to 20-25°C and stir for 24 hours;

[0087] (4) After the reaction is completed, 1.5 kg of 30% sodium hydroxide solution is added, and the temperature is raised to 50 ° C. and stirred for 2 hours for quenching. After the quenching is completed, it is allowed to stand for 15-30 minutes, cooled to room temperature, and separated. The upper layer of the reaction liquid is collected, 370 g of granular white clay is added, filtered, and the filtrate is collected and distilled under reduced pressure. The fractions are collected and hydrogenated to obtain the product mPAO2. The kinematic viscosity at 100 ° C is 1.8940 mm 2 / s, high temperature GC see attached Figure 2 .

[0088] Preparation Example 4

[0089] (1) Raw materials are put into the kettle: 12.1 kg C 10 H 20 and 24.9kg C8H 16 Add to a 150L reactor, replace with nitrogen three times, and cool to 10-15°C;

[0090] (2) Preparation of metallocene catalyst: Add 28.3 g of metallocene catalyst, 29.0 g of 4PHB-N, and 150 g of o-difluorobenzene into a batching kettle, stir until clear, and set aside;

[0091] (3) 2.0 kg Al i Add Bu3 to the reactor in (1), stir for 10-20 minutes, then add the metallocene catalyst prepared in (2) at one time, continue stirring for 10-20 minutes, then heat to 20-25°C and stir for 24 hours;

[0092] (4) After the reaction is completed, 1.5 kg of 30% sodium hydroxide solution is added, and the temperature is raised to 50° C. and stirred for 2 h to quench. After the quenching is completed, the mixture is allowed to stand for 15-30 min, cooled to room temperature, and separated. The upper layer of the reaction liquid is collected, 370 g of granular clay is added, filtered, and the filtrate is collected and distilled under reduced pressure. The fractions are collected and hydrogenated to obtain the product mPAO2.5, and its kinematic viscosity at 100° C. is 2.5651 mm 2 / s, high temperature GC see attached Figure 3 .

[0093] Preparation Example 5

[0094] (1) Raw materials are put into the kettle: 26.3 kg C 10 H 20 and 10.7kg C8H 16Add to a 150L reactor, replace with nitrogen three times, and cool to 10-15°C;

[0095] (2) Preparation of metallocene catalyst: Add 25.0 g of metallocene catalyst, 25.6 g of 4PHB-N, and 150 g of o-difluorobenzene into a batching kettle, stir until clear, and set aside;

[0096] (3) 1.77 kg Al i Add Bu3 to the reactor in (1), stir for 10-20 minutes, then add the metallocene catalyst prepared in (2) at one time, continue stirring for 10-20 minutes, then heat to 20-25°C and stir for 24 hours;

[0097] (4) After the reaction is completed, 1.5 kg of 30% sodium hydroxide solution is added, and the temperature is raised to 50 ° C. and stirred for 2 hours for quenching. After the quenching is completed, it is allowed to stand for 15-30 minutes, cooled to room temperature, and separated. The upper reaction liquid is collected, 370 g of granular white clay is added and filtered, the filtrate is collected and distilled under reduced pressure, and the heavy fraction is collected and hydrogenated to obtain the product mPAO3. The kinematic viscosity at 100 ° C is 3.0393 mm 2 / s, high temperature GC see attached Figure 4 .

[0098] Comparative Example Preparation 1

[0099] The kinematic viscosity of commercially available PAO2 at 100°C is 1.8270 mm 2 / s, and the kinematic viscosity at 40℃ is 5.0131mm 2 / s, pour point is -54℃, flash point is 149℃.

[0100] Comparative Preparation Example 2

[0101] PAO2.5 was prepared by mixing commercially available PAO2 and commercially available PAO4 in a weight ratio of 1.43:1. Its kinematic viscosity at 100°C was 2.5538 mm 2 / s.

[0102] Among them, the commercially available PAO2 has a kinematic viscosity of 1.8270 mm at 100°C. 2 / s, and the kinematic viscosity at 40℃ is 5.0131mm 2 / s, pour point is -54℃, flash point is 140℃. Commercially available PAO4: kinematic viscosity at 100℃ is 4.1mm 2 / s, kinematic viscosity at 40℃ is 19.0mm 2 / s, pour point is less than -60℃, and flash point is 252℃.

[0103] Comparative Preparation Example 3

[0104] PAO3 was prepared by mixing commercially available PAO2 and commercially available PAO4 in a weight ratio of 1:1.62. The kinematic viscosity at 100°C was 3.0124 mm 2 / s.

[0105] Among them, the commercially available PAO2 has a kinematic viscosity of 1.8270 mm at 100°C. 2 / s, and the kinematic viscosity at 40℃ is 5.0131mm 2 / s, pour point is -54℃, flash point is 140℃. Commercially available PAO4: kinematic viscosity at 100℃ is 4.1mm 2 / s, kinematic viscosity at 40℃ is 19.0mm 2 / s, pour point is less than -60℃, and flash point is 252℃.

[0106] Test 1: The base oils in Preparation Examples 1-5 and Comparative Preparation Examples 1-3 were subjected to physical and chemical property tests. The test results are shown in Table 2 below.

[0107] It can be seen from the test results in Table 2 that, under the premise of the same kinematic viscosity, the base oil prepared in the present application has a higher viscosity index and better high and low temperature performance, especially the flash point is much higher than that of commercially available or formulated base oils.

[0108] Table 2

[0109]

[0110] Test 2: The base oils in Preparation Examples 4 and 5 and Comparative Preparation Examples 2 and 3 were tested for traction coefficient.

[0111] in Figure 5 This is a relationship diagram between different sliding-rolling ratios and traction coefficients of mAPO2.5 prepared in Example 4 of this application and PAO2.5 prepared in Comparative Example 2. Figure 7 This is a relationship diagram between different sliding-rolling ratios and traction coefficients of mPAO3 in Preparation Example 5 of this application and PAO3 formulated in Comparative Preparation Example 3. The test conditions are: load 37N, temperature 80°C, and rotation speed 2m / s.

[0112] Figure 6 This is a graph showing the relationship between different rates and traction coefficients for mAPO2.5 prepared in Example 4 of this application and PAO2.5 prepared in Comparative Example 2. Figure 8 This is a relationship diagram between different speeds and traction coefficients of mPAO3 in Preparation Example 5 of this application and PAO3 formulated in Comparative Preparation Example 3. The test conditions are: load 37N, temperature 40°C, and slide-to-roll ratio 50%.

[0113] The traction coefficient of lubricating oil refers to the adhesion between the lubricating oil and the friction surface, which directly affects the friction, wear and energy consumption of the machine. The smaller the traction coefficient, the smaller the friction and wear, and the energy consumption is also reduced accordingly. Figure 5-8The results show that the traction coefficients of mPAO2.5 and mPAO3 prepared in this application are smaller than those of formulated PAO2.5 and PAO3.

[0114] Example: Lubricating oil composition

[0115] The preparation method of the lubricating oil composition is as follows: base oil and viscosity modifier are mixed and stirred evenly, optionally heated to 40° C., and then various additives are added and stirred evenly to obtain the lubricating oil composition.

[0116] Table 3 shows the formulations of Examples 1-5 and Comparative Examples 1-3.

[0117] in,

[0118] The polyalphaolefin base oil includes mPAO1 in Preparation Example 1, mPAO2 in Preparation Example 2, mPAO2.5 in Preparation Example 3, mPAO3 in Preparation Example 4, the commercially available PAO2 in the comparative preparation example, the formulated PAO2.5 in the comparative preparation example, and the formulated PAO3 in the comparative preparation example;

[0119] Viscosity modifiers include mPAO40 (kinematic viscosity at 100°C is 39.6 mm 2 / s, viscosity index is 173, pour point is -48 ° C), mPAO150 (100 ° C kinematic viscosity is 159mm 2 / s, viscosity index is 212, pour point is -24 ° C);

[0120] Additives include: antioxidant TH-1135, chemical name is 3,5-di-tert-butyl-4-hydroxyphenylpropionate (2-ethylhexyl ester); detergent dispersants T154A and T154B, T154A is polyisobutylene succinimide, T154B is a boronated polysuccinimide dispersant; ashless extreme pressure agent ADDITIN RC8213, its chemical composition is a thiadiazole derivative; Xinxing No. 1 composite anti-foaming agent, the chemical composition is a compound of polydimethylsiloxane and alkyl acrylate polymer; extreme pressure and anti-wear agents include T304, Irgalube TPPT or Irgalube 353, among which T304 is dibutyl phosphite, Irgalube TPPT is triphenylthiophosphate, and Irgalube353 is dithiophosphate.

[0121] Examples 1-5, Comparative Examples 1-3

[0122] Table 3 (Unit: mass percentage %)

[0123]

[0124]

[0125] Performance testing

[0126] Relevant test methods and standards:

[0127] Kinematic viscosity and viscosity index: The kinematic viscosity of the lubricating oil composition is tested using ASTM D445, with the unit being mm 2 / s (or cSt), and the corresponding viscosity index is tested and calculated using the table method in ASTM D2270 (the kinematic viscosity of the lubricating oil composition of this application at 100°C is 2.5 mm 2 / s, between 2-70mm 2 / s).

[0128] Pour point: The pour point of the lubricating oil composition is tested using ASTM D97, with the unit being °C.

[0129] Flash point: The flash point of the lubricating oil composition is tested using ASTM D92, with the unit being °C.

[0130] Copper sheet rust resistance: The lubricating oil composition was tested at 100°C for 24 hours using GB / T 5096 standard, and the rust grade obtained from the test was recorded.

[0131] Liquid phase corrosion: GB / T 11143 (Method A) was used to test the liquid phase corrosion resistance of the lubricating oil composition.

[0132] Oxidation resistance: The rotating oxygen bomb test (RBOT) in the SH / T 0193 standard is used to test the oxidation stability of the lubricating oil composition. The oxidation stability of the sample is expressed in minutes based on the oxygen bomb test time. A longer oxygen bomb test time indicates a higher oxidation stability.

[0133] Acid value: The acid value of the lubricating oil composition is measured using ASTM D974, and the unit is mgKOH / g.

[0134] Viscosity shear stability: The viscosity shear stability of the lubricating oil composition was measured using a tapered roller bearing tester according to the NB / SH / T 0845-2010 standard. After 20 hours of testing, the shear stability of the lubricating oil composition at 100°C was recorded before and after the test, and the relative viscosity loss R was calculated. v (%), by R v Characterize the viscosity shear stability of different samples, R v The lower the value, the higher the viscosity shear stability. v The calculation formula is: Where V s is the kinematic viscosity of the lubricating oil composition at 100°C before the test, V E It is the kinematic viscosity of the lubricating oil composition at 100°C after the test.

[0135] Anti-friction properties: The anti-wear properties of the lubricating oil compositions were tested using a four-ball testing machine according to the NB / SH / T 0189-2017 standard. The four-ball test conditions were: load 392N (40kgf), spindle speed 1200r / min, test time 60min, and test temperature 75°C. After the test, the wear spot diameter of the steel balls was measured (in mm). The smaller the wear spot diameter, the better the anti-wear properties of the composition.

[0136] Friction and Coefficient of Friction: In the four-ball test described above, the friction force f (in gf) is automatically recorded by the testing machine at intervals during the 60-minute test. The arm length of the testing machine is 3 inches (7.62 cm). The coefficient of friction u at each time point is calculated using the following formula from the recorded friction force f. The calculation formula for u is: Where u is the friction coefficient at each time point, f is the friction force, and p is the test load. The average friction coefficient u for each lubricant composition is obtained by summing the friction coefficients u at each time point. A lower average friction coefficient indicates a stronger inter-friction performance of the corresponding lubricant composition, and is therefore more effective in reducing the friction coefficient between steel balls.

[0137] Evaporation loss: The lubricating oil composition was heated at 250° C. for 60 min using the Noack evaporation loss test method of standard ASTM D5800, and the corresponding evaporation loss mass percentage was recorded in wt %.

[0138] Anti-foaming performance: The anti-foaming performance of the lubricating oil composition was tested according to GB / T 12579. The foam volume immediately after the introduction of air (foaming tendency) and the foam volume after standing for 5 minutes (foam stability) at different temperatures were recorded.

[0139] Thermal conductivity: The thermal conductivity of the lubricating oil composition was measured using ASTM E1269, and the unit is W / (m·K).

[0140] The test results are shown in Table 4.

[0141] Table 4

[0142]

[0143]

[0144] It can be seen from the test results in Table 4 that the present invention uses a self-made 100°C kinematic viscosity of 1.0-3.0 mm 2 / s PAO is used as the base oil. Regardless of whether a viscosity modifier is added, the formulated lubricating oil composition has excellent high and low temperature performance, mechanical shear stability, anti-friction performance and thermal conductivity, and has low Noack evaporation loss. The comprehensive indicators are far superior to market products.

[0145] The above is a description of the embodiments of the present invention. The above description of the disclosed embodiments will enable professionals in the field to implement or use the present invention. Various modifications to these embodiments will be apparent to professionals in the field. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An ultra-low viscosity lubricating oil composition, characterized in that: The composition comprises the following components in weight percentage: a. A first base oil having a kinematic viscosity at 100° C. of 0.9366 to 3.0393 mm² as measured in accordance with ASTM D445. 2 / s and a pour point of not higher than -60°C as determined in accordance with ASTM D97, in an amount of 90 to 98% by weight of the composition; b. Viscosity regulator, content is 0-5%; c. Additives 0-5%; The first base oil is poly-α-olefin, which is prepared from α-olefin raw materials in the presence of a metallocene catalyst system consisting of a metallocene main catalyst, an organic borate co-catalyst and a Lewis acid co-catalyst; The metallocene primary catalyst is an organic compound with Ti as the metal center, and its chemical structure is: Wherein, A1, A2, and A3 are each independently selected from halogen, a substituted or unsubstituted B group, and the B group includes any one of a C1-C40 alkyl group, a C3-C40 cycloalkyl group, a C2-C40 heterocycloalkyl group, a C6-C60 aryl group, a C4-C60 heteroaryl group, a C7-C60 aralkyl group, and a C6-C60 heteroaralkyl group.

2. The ultra-low viscosity lubricating oil composition according to claim 1, characterized in that: The B group includes any one of a C1-C5 alkyl group, a C3-C10 cycloalkyl group, a C2-C6 heterocycloalkyl group, a C2-C10 unsaturated hydrocarbon group, a C6-C15 aryl group, a C4-C15 heteroaryl group, a C7-C15 aralkyl group, and a C6-C15 heteroaralkyl group.

3. The ultra-low viscosity lubricating oil composition according to claim 1, characterized in that: The preparation method of the first base oil polyalphaolefin is: (1) α-olefin as raw material is added to the kettle; (2) preparing a metallocene catalyst: uniformly mixing a metallocene primary catalyst, an organic borate cocatalyst, a Lewis acid cocatalyst, and a solvent; (3) adding a metallocene catalyst to a kettle, heating and reacting for a period of time to obtain a crude product; (4) post-processing the crude product to obtain the poly-α-olefin.

4. The ultra-low viscosity lubricating oil composition according to claim 3, characterized in that: The α-olefin is selected from one or more of α-pentene, α-hexene, α-heptene, α-octene, α-nonene and α-decene. The prepared poly α-olefin PAO is a trimer structure of the above α-olefin. The poly α-olefin is composed of a mixture of compounds represented by the following formulas (I) and (II): wherein R1 to R6 are each independently a straight-chain C3-C8 alkane; And / or, the organic borate co-catalyst is any one or more of a boron compound such as trityltetrakis(pentafluorophenyl)borate, tri(p-octylphenyl)methyltetrakis(pentafluorophenyl)borate, dimethylphenylammoniumtetrakis(pentafluorophenyl)borate, diethylphenylammoniumtetrakis(pentafluorophenyl)borate, methyldiphenylammoniumtetrakis(pentafluorophenyl)borate, ethyldiphenylammoniumtetrakis(pentafluorophenyl)borate, methyldi(octadecyl)ammoniumtetrakis(pentafluorophenyl)borate, and trioctylammoniumtetrakis(pentafluorophenyl)borate; And / or, the Lewis acid co-catalyst is a decane solution of triisobutylaluminum.

5. The ultra-low viscosity lubricating oil composition according to claim 1, characterized in that: The lubricating oil composition has a viscosity of 1.5 to 4.0 mm as measured according to ASTM D445. 2 / s at 100°C kinematic viscosity, a pour point not higher than -60°C as measured according to ASTM D97, a thermal conductivity not higher than 0.135 W / (m·K) as measured according to ASTM E1269, and a Noack evaporation loss not higher than 15 wt% as measured according to ASTM D5800.

6. The ultra-low viscosity lubricating oil composition according to claim 1, characterized in that: The viscosity modifier includes a viscosity index improver for improving the shear stability of the lubricating oil composition and / or a second base oil for improving the viscosity of the lubricating oil composition.

7. The ultra-low viscosity lubricating oil composition according to claim 1, characterized in that: The second base oil is a polyalphaolefin; the polyalphaolefin is a polymer prepared by polymerizing alpha-olefins in the presence of a catalyst system and selectively hydrogenating to remove residual carbon-carbon double bonds; the polyalphaolefin specifically includes metallocene PAO (mPAO) and conventional non-metallocene PAO (cPAO); the mPAO is prepared using a metallocene catalyst system, and the cPAO is prepared using a conventional non-metallocene catalyst system; in, The α-olefin is a linear α-olefin composed of monomers with 5 to 10 carbon atoms, which is prepared by low-carbon olefin homopolymerization, high-carbon alcohol dehydration, Fischer-Tropsch process or ethylene oligomerization; The metallocene catalyst system comprises at least one metallocene catalyst, which is an inorganic-organic complex containing at least one cyclopentadiene or cyclopentadiene derivative as a ligand and at least one Group IVB transition element as a central atom. The non-metallocene catalyst system comprises at least one non-metallocene catalyst, which includes: a non-metallocene inorganic-organic complex formed by a ligand without a cyclopentadiene structure and a transition metal or rare earth metal element, wherein the metal center includes a transition metal and a rare earth metal element from Group IIIB to Group VIII, coordinated with a ligand containing heteroatoms such as N, O, S, and P; a homogeneous Lewis acid catalyst; a heterogeneous Lewis acid catalyst composed of the above homogeneous Lewis acid catalyst and an inorganic porous material, wherein the inorganic porous material is selected from one or more of mesoporous carbon, carbon nanotubes, activated carbon fibers, acetylene black, carbon black, expanded graphite, and graphene; a Ziegler-Natta catalyst composed of Et3Al and TiCl4; and a chromium-based catalyst.

8. The ultra-low viscosity lubricating oil composition according to claim 1, characterized in that: The additives include, but are not limited to, one or more of antioxidants, detergent dispersants, ashless dispersants, antifoaming agents, and extreme pressure antiwear agents.

9. The ultra-low viscosity lubricating oil composition according to claim 8, characterized in that: The antioxidant is one or more of a phenolic antioxidant, a phosphite antioxidant and an amine antioxidant; the amount of the antioxidant added is 0.01-5wt%; Wherein, the phenolic antioxidant is selected from 2,4-di-tert-butylphenol, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate n-octadecyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl) propionate, )benzene, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, triethylene glycol-bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, 4,4'-thiobis(6-tert-butyl-3-methylphenol), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid isooctyl ester, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 2,2'-thiodiethylbis (3-(3,5-di-tert-butyl-4-hydroxyphenyl) acrylic acid) one or more; the phosphite antioxidant is selected from tris-nonylphenol phosphite, tris[2,4-di-tert-butylphenyl] phosphite, bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, 2,2'-ethylenebis(4,6-di-tert-butylphenyl) fluorophosphite, carbonyl-4,4'-diisopropyl-fatty alcohol-phosphite, diphenyl monoisodecyl phosphite, phosphorous acid One or more of triethyl phosphite, tributyl phosphite, and trioctyl phosphite; the amine antioxidant is one or more selected from diphenylamine, hydroxylamine, N,N'-diaryl-p-phenylenediamine, N,N'-diarylbutyl-p-phenylenediamine, N-aryl-N'-alkyl-p-phenylenediamine, 3,5-diethyltoluenediamine, N-phenylnaphthylamine, N,N'-dialkyl-p-phenylenediamine, dialkyldiphenylamine, diaminotoluene and its derivatives, 1,8-diaminonaphthalene and its derivatives; The antioxidant used is antioxidant TH-1135, whose chemical name is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; The detergent dispersant is a polyisobutylenyl succinimide derivative selected from one or more of monoalkenyl succinimide, polyisobutylenyl succinimide, polyisobutylene polysuccinimide and boronated polysuccinimide; The detergent dispersant is T154A or T154B, wherein T154A is polyisobutylene succinimide and T154B is boronated polysuccinimide; The ashless dispersant is ADDITIN RC8210 or ADDITIN RC8213, whose chemical composition is a thiadiazole derivative; The anti-foaming agent is one or more of silicone oil, fluorosilicone oil and other silicone series, fluoroalkyl ether and other ether series; The antifoaming agent is Xinxing No. 1 composite antifoaming agent, whose chemical composition is a compound of polydimethylsiloxane and alkyl acrylate polymer; The extreme pressure anti-wear agent is one or more of sulfided olefins, disulfide aromatic hydrocarbons, sulfided oils and fats, thiophosphates, alkyl phosphates, sulfur and phosphorus nitrogen derivatives, and thiophosphate complex ester amine salts; The extreme pressure anti-wear agent is T304, Irgalube TPPT or Irgalube 353, wherein T304 is dibutyl phosphite, Irgalube TPPT is triphenyl thiophosphate, and Irgalube 353 is dithiophosphate.

10. The method for preparing an ultra-low viscosity lubricating oil composition according to any one of claims 1 to 9, characterized in that: The first base oil and the viscosity modifier are mixed and stirred uniformly, heated to 40-80° C., and then various additives are added and stirred uniformly to obtain a lubricating oil composition.

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