Lubricating oil as well as preparation method and application thereof

Abstract

The invention provides lubricating oil as well as a preparation method and application thereof. The lubricating oil comprises the following components in parts by weight: 90-98 parts of base oil; 1.5 to 13 parts by weight of an additive; wherein the base oil at least comprises alkyl naphthalene, based on the total weight of the lubricating oil, the addition amount of the alkyl naphthalene is 5-98 parts by weight, and the kinematic viscosity of the alkyl naphthalene at 100 DEG C is 3-25 cSt; the additive at least comprises an antioxidant, the antioxidant is an aromatic amine compound, and the addition amount of the aromatic amine compound is 0.5-5 parts by weight based on the total weight of the lubricating oil. The lubricating oil is high-temperature-resistant and fluorescent self-tracing lubricating oil, the oxygen bomb rotation time of the lubricating oil at 150 DEG C can reach 2000 min or above, alkyl naphthalene in the lubricating oil can achieve a synergistic effect with aromatic amine compounds, and the oxidation resistance is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oils, and in particular to a lubricating oil, a preparation method thereof, and an application thereof. Background Art

[0002] High-temperature parts are common in various industrial machinery and equipment in industries such as steel metallurgy, petrochemicals, automobile manufacturing, thermal power generation, cigarette manufacturing, and mining. For example, vertical mill roller bearings often experience temperatures exceeding 100°C. These components, exposed to complex operating conditions such as high temperature, high humidity, and dust, place high demands on the high-temperature resistance of lubricants and greases. These oils must possess high-temperature resistance and oxidation resistance to ensure stable operation of the equipment under high-temperature conditions. Grease must also remain stable in high-temperature environments, preventing loss or decomposition. Improper lubricant selection for high-temperature areas can lead to adverse effects such as sludge deposition, component corrosion, and equipment wear. Long-term improper oil use can also lead to abnormal equipment shutdown, damage, or even premature scrapping, resulting in serious consequences such as safety hazards. Furthermore, oil leaks at high temperatures pose a fire risk.

[0003] To address the lubrication needs of high-temperature parts of industrial equipment, two main oil solutions are currently in use. One is based on polyglycol (PAG) as the primary base oil. This solution primarily utilizes PAG base oils, which are less prone to deposits and carbon buildup, supplemented with antioxidants, metal deactivators, and other additives to meet the lubrication needs of high-temperature components. The other technical solution primarily utilizes base oils that generate sludge and carbon buildup, such as isomerized hydrogenated base oils, polyalphaolefin (PAO) base oils, and synthetic esters. Through the rational combination of anti-wear agents, antioxidants, metal passivators, and metal detergents, the oil is designed to be less prone to sludge and carbon buildup at high temperatures, thus meeting the lubrication needs of high-temperature components. Because the pyrolysis products of PAG base oils are gases, they do not produce sludge or carbon buildup at high temperatures. However, this characteristic results in rapid oil consumption during use, and if the lubricant is not replenished for an extended period, a lack of lubrication can easily occur. However, achieving a balance between high-temperature resistance, wear resistance, emulsification resistance, corrosion resistance, and rust prevention through additive formulation technology combined with high-quality hydrocarbon base oils is technically challenging. Currently, high-temperature antioxidant formulation technology primarily relies on a combination of amine and phenolic antioxidants. Phenolic antioxidants readily generate hydroperoxides at high temperatures, which automatically undergo thermo-oxidative aging reactions and are unable to decompose by themselves. Furthermore, phenolic antioxidants may produce colored substances at high temperatures, causing discoloration of the product and affecting its appearance and quality. Furthermore, leaks in oils used in high-temperature environments pose a risk of fire or equipment contamination. Early detection of oil leaks through oil tracing technology combined with other monitoring technologies is key to addressing unnecessary losses caused by oil leaks in high-temperature environments. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the object of the present invention is to provide a lubricating oil and its preparation method and use, which are used to solve the problems of insufficient high temperature resistance and oxidation resistance of lubricating oils and greases in the prior art, limited synergistic effect of existing antioxidants after compounding, and easy discoloration and pollution at high temperatures.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides a lubricating oil, a preparation method thereof, and uses thereof.

[0006] The first aspect of the present invention provides a lubricating oil comprising the following components in parts by weight:

[0007] 90-98 parts by weight of base oil;

[0008] 1.5 to 13 parts by weight of additives;

[0009] The base oil at least includes alkyl naphthalene, and the amount of the alkyl naphthalene added is 5 to 98 parts by weight based on the total weight of the lubricating oil. The kinematic viscosity of the alkyl naphthalene at 100°C is 3 to 25 cSt. The additive at least includes an antioxidant, and the antioxidant is an aromatic amine compound. The amount of the aromatic amine compound added is 0.5 to 5 parts by weight based on the total weight of the lubricating oil.

[0010] In the present invention, the base oil may consist solely of alkylnaphthalene or may be a mixed base oil with other base oils added. In lubricating oil, alkylnaphthalene as a base oil may also act in conjunction with aromatic amine compounds as an antioxidant.

[0011] Further preferably, based on the total weight of the lubricating oil, the amount of alkyl naphthalene added can be 5 parts by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight, 80 parts by weight, 90 parts by weight or 98 parts by weight.

[0012] Further preferably, the kinematic viscosity of the alkyl naphthalene at 100° C. may be 3 cSt, 5 cSt, 8 cSt, 10 cSt, 12 cSt, 15 cSt, 18 cSt, 20 cSt, 22 cSt or 25 cSt.

[0013] Further preferably, based on the total weight of the lubricating oil, the added amount of the aromatic amine compound can be 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight or 5 parts by weight.

[0014] More preferably, based on the total weight of the lubricating oil, the amount of the aromatic amine compound added is 0.5 to 3 parts by weight; for example, it can be 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight or 3 parts by weight.

[0015] Preferably, the base oil further comprises any one or more of hydrocarbon oil, ester oil, silicone oil or fluoro oil.

[0016] More preferably, the hydrocarbon oil is any one or two selected from PAO and CTL.

[0017] More preferably, the PAO is PAO2-200; for example, it can be PAO2, PAO5, PAO10, PAO20, PAO30, PAO40, PAO50, PAO60, PAO65, PAO70, PAO80, PAO90, PAO100, PAO120, PAO150, PAO160, PAO170, PAO180, or PAO200. The following number represents its kinematic viscosity at 100°C (in cSt). For example, the kinematic viscosity of PAO2 at 100°C is 2 cSt.

[0018] More preferably, the CTL is CTL5-15, for example, CTL5, CTL6, CTL7, CTL8, CTL9, CTL10, CTL11, CTL12, CTL13, CTL14, or CTL15. The number following the CTL represents the kinematic viscosity at 100°C (in cSt). For example, the kinematic viscosity of CTL5 at 100°C is 5 cSt.

[0019] More preferably, the ester oil is any one or more selected from diesters, polyol esters, complex esters, and phosphate esters.

[0020] More preferably, the silicone oil is any one or more selected from polydimethylsiloxane, phenyl silicone oil, and polyether-modified silicone oil.

[0021] More preferably, the fluoro oil is any one or more selected from perfluoropolyether oil, perfluorocarbon oil, and fluorosilicone oil.

[0022] Preferably, the aromatic amine compound is any one or more selected from phenothiazine, alkylphenothiazine, N-phenyl-α-naphthylamine, alkylated-N-phenyl-α-naphthylamine, and alkyldiphenylamine.

[0023] Preferably, the additive further comprises the following components in parts by weight:

[0024] 0.5-2 parts by weight of antiwear agent;

[0025] 0.5-1 parts by weight of friction modifier;

[0026] 0.15-1 parts by weight of metal passivator;

[0027] 0.05-0.2 parts by weight of rust inhibitor;

[0028] 0.01-0.1 parts by weight of antifoaming agent;

[0029] Adhesive 0.01 to 1 parts by weight.

[0030] Further preferably, based on the total weight of the lubricating oil, the added amount of the antiwear agent may be 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight or 2 parts by weight.

[0031] Further preferably, based on the total weight of the lubricating oil, the added amount of the friction modifier may be 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight or 1 part by weight.

[0032] Further preferably, based on the total weight of the lubricating oil, the added amount of the metal passivator can be 0.15 weight part, 0.2 weight part, 0.3 weight part, 0.4 weight part, 0.5 weight part, 0.6 weight part, 0.7 weight part, 0.8 weight part, 0.9 weight part or 1 weight part.

[0033] Further preferably, based on the total weight of the lubricating oil, the added amount of the rust inhibitor may be 0.05 parts by weight, 0.08 parts by weight, 0.1 parts by weight, 0.12 parts by weight, 0.15 parts by weight, 0.18 parts by weight or 0.2 parts by weight.

[0034] Further preferably, based on the total weight of the lubricating oil, the added amount of the antifoaming agent can be 0.01 parts by weight, 0.02 parts by weight, 0.04 parts by weight, 0.05 parts by weight, 0.06 parts by weight, 0.08 parts by weight or 0.1 parts by weight.

[0035] Further preferably, based on the total weight of the lubricating oil, the added amount of the adhesive may be 0.01 parts by weight, 0.05 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight or 1 part by weight.

[0036] Preferably, the base oil further comprises PAO.

[0037] More preferably, the ratio of the addition amount of PAO and alkyl naphthalene in the base oil is (70-90): (10-30).

[0038] More preferably, the ratio of the addition amount of PAO and alkyl naphthalene in the base oil is (75-90):(10-20); for example, it can be 75:10, 75:15, 75:20, 80:10, 80:15, 80:20, 85:10, 85:15, 85:20, 90:10, 90:15, 90:20.

[0039] In some preferred embodiments of the present invention, the base oil is a mixture of PAO and alkyl naphthalene.

[0040] Most preferably, when the base oil is a mixture of PAO and alkyl naphthalene, the ratio of the added amounts of PAO and alkyl naphthalene is (8-9):1; for example, it can be 8:1, 8.5:1 or 9:1.

[0041] In some preferred embodiments of the present invention, the base oil is a mixture of PAO, alkyl naphthalene and CTL.

[0042] Most preferably, when the base oil is a mixture of PAO, alkyl naphthalene and CTL, the ratio of the added amounts of PAO, alkyl naphthalene and CTL is (4-6):2:(1-2); for example, it can be 4:2:1, 4:2:2, 5:2:1, 5:2:2, 6:2:1 or 6:2:2.

[0043] Most preferably, the PAO is any one or two selected from PAO65 and PAO150; the following number represents its kinematic viscosity at 100°C (in cSt).

[0044] Most preferably, the alkyl naphthalene is any one or more selected from AN5, AN12, and AN23; the following number represents its kinematic viscosity at 100°C (in cSt).

[0045] Most preferably, the CTL is CTL10; the number following it represents its kinematic viscosity at 100°C (in cSt).

[0046] Preferably, the anti-wear agent is any one or more selected from phosphate amine salts, phosphite amine salts, nitrogen-containing heterocyclic phosphite amine salts, dialkyl dithiophosphates or dialkyl dithiocarbamates.

[0047] More preferably, the anti-wear agent is a mixed anti-wear agent formed by compounding tricresyl phosphate, dibutyl phosphite and acidic phosphate amine salt.

[0048] Most preferably, the ratio of the added amounts of tricresyl phosphate, dibutyl phosphite and acidic phosphate amine salt in the mixed anti-wear agent is 5:(3-4):(1-2); for example, it can be 5:3:1, 5:3:1.5, 5:3:2, 5:3.5:1, 5:3.5:1.5, 5:3.5:2, 5:4:1, 5:4:1.5, 5:4:2.

[0049] Preferably, the friction modifier is any one or more selected from benzotriazole octadecylamine salt, dialkyldithiocarbamate molybdenum, borate, and triazine derivatives. The structural formula of the triazine derivative is shown in Formula II:

[0050] , wherein R is independently selected from H, a linear alkyl group having 8 to 18 carbon atoms, or a branched alkyl group having 8 to 18 carbon atoms.

[0051] More preferably, the friction modifier is a triazine derivative.

[0052] More preferably, the triazine derivative has the structural formula II-1 shown as follows:

[0053]

[0054] Preferably, the metal deactivator is any one or more selected from benzotriazole derivatives, thiadiazole derivatives, and imidazoline derivatives.

[0055] In some preferred embodiments of the present invention, the metal deactivator is a thiadiazole derivative.

[0056] In some preferred embodiments of the present invention, the metal deactivator is a benzotriazole derivative.

[0057] Preferably, the rust inhibitor is any one or two selected from petroleum sulfonate and stearamide.

[0058] More preferably, the base value of the petroleum sulfonate is less than 20 mg KOH / g.

[0059] More preferably, the base value of the petroleum sulfonate is 5 to 20 mg KOH / g; for example, it can be 5 mg KOH / g, 6 mg KOH / g, 8 mg KOH / g, 10 mg KOH / g, 12 mg KOH / g, 15 mg KOH / g, 18 mg KOH / g or 20 mg KOH / g.

[0060] Preferably, the antifoaming agent is any one or two selected from organic silicon polymers and organic polyether esters.

[0061] Further preferably, the number average molecular weight of the organosilicon polymer is 4000-7000 Da; for example, it can be 4000 Da, 5000 Da, 6000 Da or 7000 Da.

[0062] Further preferably, the number average molecular weight of the organosilicon polymer is 4000-7000 Da; for example, it can be 4000 Da, 5000 Da, 6000 Da or 7000 Da.

[0063] Preferably, the adhesion agent is any one or more selected from terpene resin, rosin, polyester.

[0064] Further preferably, the dynamic viscosity of the terpene resin is in the range of 80000-100000 mPa·s; for example, it can be 80000 mPa·s, 85000 mPa·s, 90000 mPa·s, 95000 mPa·s or 100000 mPa·s.

[0065] Further preferably, the dynamic viscosity of the rosin is in the range of 80000-100000 mPa·s; for example, it can be 80000 mPa·s, 85000 mPa·s, 90000 mPa·s, 95000 mPa·s or 100000 mPa·s.

[0066] Further preferably, the dynamic viscosity of the polyester is in the range of 80000-100000 mPa·s; for example, it can be 80000 mPa·s, 85000 mPa·s, 90000 mPa·s, 95000 mPa·s or 100000 mPa·s.

[0067] In some preferred embodiments of the present application, the antioxidant is a mixed antioxidant formed by compounding alkylated-N-phenyl-α-naphthylamine and alkyl diphenylamine.

[0068] More preferably, the ratio of the addition amount of the alkylated-N-phenyl-α-naphthylamine and the alkyl diphenylamine is 1:(0.5-1.5); for example, it can be 1:0.5, 1:1 or 1:1.5.

[0069] In some preferred embodiments of the present application, the antioxidant is a mixed antioxidant formed by compounding a mixture of alkyl phenothiazine and phenothiazine with alkylated-N-phenyl-α-naphthylamine.

[0070] More preferably, the ratio of the addition amount of the mixture of alkyl phenothiazine and phenothiazine and the alkylated-N-phenyl-α-naphthylamine is 1:(0.5-1.5); for example, it can be 1:0.5, 1:1 or 1:1.5.

[0071] Preferably, the alkylated-N-phenyl-α-naphthylamine is 1-octylated-N-phenyl-α-naphthylamine.

[0072] Preferably, the alkyl diphenylamine is any one or more selected from octyl / butyl diphenylamine, dioctyl diphenylamine, dinonyl diphenylamine, and butyl octyl diphenylamine.

[0073] Preferably, the structure of the alkyl phenothiazine is as shown in Formula I:

[0074]

[0075] Wherein, R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from H, a straight-chain alkyl group having 2 to 18 carbon atoms, or a branched-chain alkyl group having 2 to 18 carbon atoms, and R1, R2, R3, R4, R5, R6, R7, and R8 are not H at the same time.

[0076] For example, the number of carbon atoms in the alkyl group can be 2, 4, 6, 8, 10, 12, 14, 16, or 18.

[0077] A second aspect of the present invention provides a method for preparing an alkyl phenothiazine, characterized in that the method comprises: using phenothiazine and olefin as raw materials, reacting in the presence of a catalyst and a co-catalyst to obtain the alkyl phenothiazine.

[0078] Preferably, the olefin is diisobutylene or an α-olefin having 2 to 18 carbon atoms; for example, the α-olefin may be: ethylene, α-propylene, α-butene, α-pentene, α-hexene, α-heptene, α-octene, α-nonene, α-decene, α-undecene, α-dodecene, α-tridecene, α-tetradecene, α-pentadecene, α-hexadecene, α-heptadecene or α-octadecene.

[0079] Preferably, the catalyst is any one or more selected from Lewis acid, acidic oxide, sulfide, modified zeolite, acidic cation exchange resin, and metal halide.

[0080] Further preferably, the Lewis acid is any one or more selected from AlCl3, FeCl3, and BF3.

[0081] Preferably, the co-catalyst is any one or more selected from water, alcohol, and protonic acid.

[0082] Preferably, the reaction further comprises a reaction solvent, and the reaction solvent is any one or more selected from petroleum ether, tetrahydrofuran, toluene, n-hexane, cyclohexane, and n-heptane.

[0083] More preferably, the boiling point of the petroleum ether is 90-120°C.

[0084] Preferably, the reaction temperature is 120-160°C, including but not limited to 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C or 160°C.

[0085] Preferably, the reaction pressure is 0-0.5 MPa; for example, it may be 0 MPa, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa or 0.5 MPa.

[0086] Preferably, the reaction time is 0.5 to 20 hours.

[0087] More preferably, the reaction time is 2 to 10 h; for example, it can be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h.

[0088] Preferably, the method further comprises a post-processing step, wherein the post-processing step comprises separation and impurity removal.

[0089] Further preferably, the separation comprises any one or more of filtration, extraction or column chromatography.

[0090] More preferably, the impurity removal includes any one or more of water washing, drying, recrystallization, concentration, filtration or distillation.

[0091] The preparation method of the present invention uses phenothiazine and olefin as raw materials and directly alkylates phenothiazine. The yield of the generated alkyl phenothiazine is high and the post-processing is simple. The prior art preparation method of alkyl phenothiazine uses diphenylamine as raw material and performs sulfurization under the catalysis of iodine to obtain the alkyl phenothiazine. Specifically, diphenylamine, iodine tablets and sulfur are mixed, heated to 200°C for reaction for 2 hours, and then directly heated to 220-250°C with superheated steam. After separation of the reaction material from water, the reaction material is washed with a mixed solution of ethanol and hexamethylenetetramine (mass ratio of 1.5:1), and then dried and pulverized to obtain the product. The disadvantage of this method is that the post-processing is complicated and the yield is low. Therefore, the present invention provides a new preparation method of alkyl phenothiazine, which improves the yield and avoids the complicated post-processing steps.

[0092] Preferably, the rotating oxygen bomb time of the lubricating oil at 150° C. is greater than 2000 min.

[0093] Further preferably, the rotating oxygen bomb time of the lubricating oil at 150° C. is 2000 to 5000 min; for example, it can be 2000 min, 2500 min, 3000 min, 3500 min, 4000 min, 4500 min or 5000 min.

[0094] Preferably, the wear spot diameter of the lubricating oil is less than 0.45 mm.

[0095] Further preferably, the wear spot diameter of the lubricating oil is 0.3-0.45 mm; for example, it can be 0.3 mm, 0.32 mm, 0.34 mm, 0.35 mm, 0.37 mm, 0.39 mm, 0.4 mm, 0.41 mm, 0.42 mm, 0.43 mm, 0.44 mm or 0.45 mm.

[0096] A third aspect of the present invention provides a method for preparing lubricating oil, characterized by comprising:

[0097] The additive is added into a stirring kettle, stirred at 40-80° C. and a rotation speed of 100-300 rpm for 40-120 minutes, and cooled to obtain an additive mixed liquid; the additive mixed liquid is mixed with base oil, stirred at 40-80° C. and a rotation speed of 100-500 rpm for 60-120 minutes, cooled and filtered to obtain the lubricating oil.

[0098] Preferably, the stirring temperature of the additive may be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[0099] Preferably, the stirring speed of the additive may be 100 rpm, 120 rpm, 150 rpm, 160 rpm, 180 rpm, 200 rpm, 220 rpm, 250 rpm, 280 rpm or 300 rpm.

[0100] Preferably, the stirring time of the additive may be 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min or 120 min.

[0101] Preferably, the stirring temperature for mixing the additive with the base oil may be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[0102] Preferably, the stirring speed of mixing the additive and the base oil may be 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm or 500 rpm.

[0103] Preferably, the stirring time for mixing the additive with the base oil can be 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min or 120 min.

[0104] Preferably, the filtration is any one or more selected from mechanical filtration, vacuum filtration, and centrifugal filtration.

[0105] Further preferably, the mechanical filtration is filter paper filtration or filter mesh filtration.

[0106] A fourth aspect of the present invention provides a use of the above-mentioned lubricating oil as a bearing and / or gear lubricating oil at -40 to 150°C.

[0107] As described above, the lubricating oil of the present invention has the following beneficial effects:

[0108] The lubricating oil of the present invention is high-temperature resistant and fluorescently traceable. Its rotary oxygen bomb time at 150° C. can reach over 2000 minutes. The alkylnaphthalene in the lubricating oil can synergistically act with the aromatic amine compound to enhance the antioxidant performance, thereby avoiding the problems of limited synergy, uncontrollable compounding ratio, high cost, and easy discoloration and pollution at high temperatures caused by the combination of different types of antioxidants. In addition, the conjugated benzene ring structure of the alkylnaphthalene and aromatic amine compound itself enables a fluorescent effect under ultraviolet light irradiation, and can be used as an indicator to indicate the consumption of lubricating oil and / or grease or detect leakage without the need for additional indicators. This is a solution with significant effects and low cost, and has broad industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0109] Figure 1 Shown is a chromatogram of the alkylphenothiazine and phenothiazine mixture prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0110] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0111] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0112] Furthermore, it should be understood that the one or more method steps mentioned in the present invention do not exclude the presence of other method steps before or after the combination step, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. It should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the presence of other devices / apparatuses before or after the combination device / apparatus, or the insertion of other devices / apparatuses between two explicitly mentioned devices / apparatuses. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be considered within the scope of the present invention.

[0113] Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific specific embodiments described below; it should also be understood that the terms used in the examples of the present invention are for describing specific specific embodiments rather than for limiting the scope of protection of the present invention; in the present specification and claims, unless otherwise expressly stated herein, the singular forms "a", "an" and "the" include plural forms.

[0114] When the embodiments provide numerical ranges, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any numerical value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those generally understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the embodiments, according to the understanding of the prior art by those skilled in the art and the description of the present invention, any methods, equipment, and materials of the prior art similar or equivalent to the methods, equipment, and materials described in the embodiments of the present invention may also be used to implement the present invention.

[0115] The applicant of the present application has found through a large number of studies that the amine antioxidant and the alkyl naphthalene base oil have a significant synergistic effect on the antioxidant performance, and the alkyl naphthalene base oil and the amine antioxidant have a fluorescence effect under ultraviolet light irradiation. Therefore, the present application is different from the technical route of improving the high-temperature resistance of the conventional high-temperature resistant lubricating oil or grease by compounding different types of antioxidants to improve the high-temperature resistance of the lubricating oil or grease, and the synergistic effect and fluorescence characteristics of the alkyl naphthalene base oil and the amine antioxidant, especially the phenothiazine and its derivatives and the alkylated phenyl alpha naphthylamine antioxidant, are fully utilized, so that the composition can emit fluorescence under ultraviolet excitation in a dark environment without additional addition of a fluorescent agent, and can be used as an indicator for oil leakage and consumption of effective components such as alkyl naphthalene and antioxidants in lubricants. Further assisted by friction modifiers and metal deactivators, the lubrication and heat resistance and antioxidant capacity of the oil product are comprehensively improved, thereby realizing the development of high-temperature resistant and fluorescent self-tracing lubricants, which is a technical solution with remarkable effect and low cost.

[0116] Example 1

[0117] The present embodiment provides a specific lubricating oil, and the formula is shown in Table 1.

[0118] The specific preparation method is as follows:

[0119] S1, the anti-wear agent, the friction modifier, the metal deactivator, the antioxidant, the anti-rust agent, the anti-foaming agent and the adhesion agent are put into a stirring kettle, heated and stirred at 60℃ and a speed of 200rmp for 60min, and then cooled to obtain an additive mixture, which is filled into a clean sealed container for storage;

[0120] S2, the base oil is put into a stirring kettle to form a base oil mixture, and the additive mixture prepared in S1 is added to the base oil mixture, which is stirred at 60℃ and a speed of 150rmp for 100min, and then filtered after cooling to obtain the lubricating oil.

[0121] Example 2

[0122] The difference between the present embodiment and Example 1 is that AN23 is replaced by AN5, and the other components, the amount of addition and the preparation method are the same as those of Example 1, and the formula is shown in Table 1.

[0123] Example 3

[0124] The difference between the present embodiment and Example 1 is that octyl / pentyl diphenylamine (Basf Irganox L57) is replaced by a mixture of alkyl phenothiazine and phenothiazine, and the other components, the amount of addition and the preparation method are the same as those of Example 1, and the formula is shown in Table 1. The preparation method of alkyl phenothiazine is as follows:

[0125] 20g of phenothiazine, 1g of aluminum chloride and 150mL of petroleum ether (PE) with a boiling point of 120°C were added to a three-necked flask. The reaction was carried out under nitrogen protection. 20g of diisobutylene was slowly added dropwise under reflux and the addition was completed within 1 hour. The reaction was allowed to react at 120°C under normal pressure for 5 hours and then cooled to terminate the reaction. The reaction mixture was filtered and washed with a 50% aqueous NaOH solution until neutral and dried over anhydrous NaSO4. The solvent, diisobutylene and other residual reagents were evaporated under reduced pressure to obtain 34.5g of a dark brown alkylphenothiazine product with a reaction yield of 86.2%. Gas chromatography analysis showed that the product was a mixture of alkylphenothiazines with different alkylation sites and partially unalkylated phenothiazines, of which the proportion of alkylphenothiazines was 86%. The specific test results are as follows: Figure 1 As shown, the retention time of phenothiazine is 14.6 min, and the peak that appears after phenothiazine is the absorption peak of alkylphenothiazine.

[0126]

[0127] wherein R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from H or Any one of .

[0128] Example 4

[0129] This embodiment differs from embodiment 1 in that the thiadiazole derivative T561 is replaced by the benzotriazole derivative BasfIRGAMET 39. The remaining components, addition amounts, and preparation methods are the same as those in embodiment 1. The formula is shown in Table 1.

[0130] Example 5

[0131] The difference between this embodiment and embodiment 1 lies in the type and amount of base oil added, while the remaining components, amounts added and preparation method are the same as those in embodiment 1. The specific formula of the base oil is shown in Table 1.

[0132] Comparative Example 1

[0133] The difference between Comparative Example 1 and Example 1 is that AN23 is replaced by polyol ester (Priolube 3970), and the remaining components, addition amounts and preparation methods are the same as those in Example 1. The formula is shown in Table 1.

[0134] Comparative Example 2

[0135] The difference between Comparative Example 2 and Example 1 is that octyl / pentyl diphenylamine (BasfIrganox L57) is replaced by a liquid high molecular weight mixed phenol antioxidant (BasfIrganox L135). The remaining components, addition amounts and preparation methods are the same as those in Example 1. The formula is shown in Table 1.

[0136] Table 1

[0137]

[0138]

[0139] The specific structural formula of the triazine derivatives in Table 1 above is as follows:

[0140]

[0141] Its specific preparation method is as follows:

[0142] 1) 2,2',2"-((1,3,5-triazine-2,4,6-triyl)tris(azodiyl))triacetic acid (intermediate) was prepared according to the method of the literature (Effects of the Chain Length of Tris(carboxyalkylamino)triazineon Corrosion Inhibition Properties; DOI: 10.1002 / bkcs.10090).

[0143] 2) In a 500 mL three-necked flask, 1 eq of the intermediate prepared in step 1) (3.151 g, 10.5 mmol), 3.6 eq of p-toluenesulfonic acid (6.27 g, 36.45 mmol), and 3.6 eq of n-dodecanol (6.77 g, 36.40 mmol) were added to a 500 mL three-necked flask, and 150 ml of toluene solution was added to form a mixture. The mixture was then azeotropically refluxed at 165 ° C. and monitored by TLC spot plate. The reaction was completed when the raw material spot disappeared.

[0144] 3) After the reaction is completed, 300 ml of water is added to the reaction mixture, and then ethyl acetate is added for extraction. The reaction solution is then washed with water (200 mL) for three consecutive washes, the organic phase is separated, and dried over anhydrous sodium sulfate. Finally, the reaction mixture is concentrated under reduced pressure. The eluate obtained by column chromatography is subjected to reduced pressure distillation to remove the solvent and vacuum dried to obtain a light yellow solid, which is the compound of formula II-1.

[0145] The lubricating oils prepared in Examples 1 to 5 and Comparative Examples 1 to 2 were further subjected to performance tests. The specific testing methods included:

[0146] Rotating oxygen bomb time / minTest method / standard: NB / SH / T 0193-2022 (Method A).

[0147] Fluorescence intensity test method: Take 1 mL of the oil to be tested and drop it on a steel sheet. After spreading for 10 minutes, irradiate the samples simultaneously with a 365 nm ultraviolet lamp and observe the fluorescence intensity of different samples by visual inspection.

[0148] Wear spot diameter / mmTest method / standard: Four-ball long grinding: SH / T 0189-2017 (Condition B).

[0149] Copper strip corrosion (100°C, 24h) test method / standard: GB / T 5096-2017.

[0150] The specific test results are shown in Table 2 below.

[0151] Table 2 Lubricant performance test data of Examples 1 to 5 and Comparative Examples 1 to 2

[0152] Test item Rotating oxygen bomb time / min Fluorescence intensity Grinding crater diameter / mm Copper sheet corrosion (100°C, 24h) Example 1 2467 Weak 0.412 1A Example 2 2145.6 Weak 0.432 1A Example 3 4388 Strong 0.404 1A Example 4 2790 Weak 0.421 1B Example 5 3400 Strong 0.37 1B Comparative Example 1 1150 Very weak 0.44 2B Comparative Example 2 754 Weak 0.414 2A

[0153] As can be seen from the data in Table 3, the lubricating oils prepared in Examples 1 to 5 exhibit excellent heat and oxidation resistance, with a rotating oxygen bomb time of more than 2000 min; excellent anti-wear performance, with a four-ball wear spot diameter of less than 0.45 mm; and excellent corrosion resistance. After a 24-hour copper sheet corrosion test at 150°C, the copper sheet corrosion grade was level 1, with no corrosion phenomenon; and fluorescence could be observed under ultraviolet light, thereby facilitating oil leak detection and component consumption.

[0154] According to the performance data of Examples 1 and 2, it can be seen that the reduction in the viscosity of alkyl naphthalene has a certain negative impact on the rotary oxygen bomb time of the lubricating oil; according to the performance data of Examples 1 and 3, it can be seen that the addition of alkyl phenothiazine can significantly improve the rotary oxygen bomb time of the lubricating oil, and due to the presence of a large conjugated system in the alkyl phenothiazine structure, it can produce strong fluorescence under ultraviolet light; according to the results of Examples 1 and 5, it can be seen that increasing the amount of alkyl naphthalene added can increase the rotary oxygen bomb time of the lubricating oil, and due to the increase in alkyl naphthalene, the conjugated system in the lubricating oil increases, so that it can produce strong fluorescence under ultraviolet light.

[0155] As can be seen from the performance data of examples 1-5 and comparative examples 1-2, the rotary oxygen bomb time of the lubricating oil in comparative examples 1-2 is greatly reduced compared with examples 1-5, and corrosion will be produced, and the anti-corrosion ability is poor. Specifically: according to the performance data of example 1 and comparative example 1, it can be seen that when the alkyl naphthalene in the lubricating oil is replaced by polyol ester, the rotary oxygen bomb time of the lubricating oil is greatly reduced; according to the performance data of example 1 and comparative example 2, it can be seen that when the antioxidant is compounded by phenolic antioxidant and amine antioxidant, the antioxidant performance of the lubricating oil is greatly reduced; it is proved that the antioxidant performance of the lubricating oil containing alkyl naphthalene and amine antioxidant in the application is significantly better than that of the antioxidant in the prior art, and has broad application prospect.

[0156] The above is only the preferred embodiment of the present application, and is not any form and substantial limitation of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the method of the present application, a number of improvements and supplements can also be made, which should be considered as the protection scope of the present application. For those skilled in the art, without departing from the spirit and scope of the present application, some changes, modifications and equivalent changes made by using the disclosed technical content are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above-mentioned embodiments according to the essential technology of the present application are still within the scope of the technical solutions of the present application.

Claims

1. A lubricating oil, characterized in that: The composition comprises the following components in parts by weight: 90-98 parts by weight of base oil; 1.5 to 13 parts by weight of additives; The base oil at least includes alkyl naphthalene, and the amount of the alkyl naphthalene added is 5 to 98 parts by weight based on the total weight of the lubricating oil. The kinematic viscosity of the alkyl naphthalene at 100°C is 3 to 25 cSt. The additive at least includes an antioxidant, and the antioxidant is an aromatic amine compound. The amount of the aromatic amine compound added is 0.5 to 5 parts by weight based on the total weight of the lubricating oil.

2. The lubricating oil according to claim 1, characterized in that The base oil further comprises any one or more of hydrocarbon oil, ester oil, silicone oil or fluoro oil; and / or the aromatic amine compound is any one or more selected from phenothiazine, alkylphenothiazine, N-phenyl-α-naphthylamine, alkylated-N-phenyl-α-naphthylamine, alkyldiphenylamine; and / or the additive further comprises the following components in parts by weight: 0.5-2 parts by weight of antiwear agent; 0.5-1 parts by weight of friction modifier; 0.15-1 parts by weight of metal passivator; 0.05-0.2 parts by weight of rust inhibitor; 0.01-0.1 parts by weight of antifoaming agent; Adhesive 0.01 to 1 parts by weight.

3. The lubricating oil according to claim 2, characterized in that The base oil also includes PAO; and / or the antiwear agent is any one or more selected from phosphate amine salts, phosphite amine salts, nitrogen-containing heterocyclic phosphite amine salts, dialkyl dithiophosphates or dialkyl dithiocarbamates; and / or the friction modifier is any one or more selected from benzotriazole octadecylamine salts, dialkyl dithiocarbamate molybdenum, borates, and triazine derivatives; and / or the metal passivator is any one or more selected from benzotriazole derivatives, thiadiazole derivatives, and imidazoline derivatives; and / or the rust inhibitor is any one or two selected from petroleum sulfonates and stearic acid amides; and / or the antifoaming agent is any one or two selected from silicone polymers and organic polyether esters; and / or the adhesive is any one or more selected from terpene resins, rosin, and polyesters.

4. The lubricating oil according to claim 3, characterized in that The ratio of the added amounts of PAO and alkyl naphthalene in the base oil is (70-90):(10-30); and / or the kinematic viscosity of the PAO at 100° C. is 2-200 cSt.

5. The lubricating oil according to claim 2, characterized in that The structure of the alkyl phenothiazine is shown in Formula I: wherein R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from H, a linear alkyl group having 2 to 18 carbon atoms, or a branched alkyl group having 2 to 18 carbon atoms, and R1, R2, R3, R4, R5, R6, R7, and R8 are not H at the same time; and / or the alkylated-N-phenyl-α-naphthylamine is 1-octylated-N-phenyl-α-naphthylamine; and / or the alkyldiphenylamine is any one or more selected from octyl / butyldiphenylamine, dioctyldiphenylamine, dinonyldiphenylamine, and butyloctyldiphenylamine.

6. A lubricating oil according to any one of claims 2 to 5, characterized in that: The preparation method of the alkyl phenothiazine comprises: taking phenothiazine and olefin as raw materials, reacting in the presence of a catalyst and a co-catalyst to obtain the alkyl phenothiazine.

7. The lubricating oil according to claim 6, characterized in that The olefin is diisobutylene or an alpha-olefin having 2 to 18 carbon atoms; and / or the catalyst is any one or more selected from Lewis acids, acidic oxides, sulfides, modified zeolites, acidic cation exchange resins, and metal halides; preferably, the Lewis acid is any one or more selected from AlCl3, FeCl3, and BF3; and / or the co-catalyst is any one or more selected from water, alcohols, and protic acids; and / or the reaction further comprises a reaction solvent, which is any one or more selected from petroleum ether, tetrahydrofuran, toluene, n-hexane, cyclohexane, and n-heptane; and / or the reaction temperature is 120 to 160°C; and / or the reaction pressure is 0 to 0.5 MPa; and / or the reaction time is 0.5 to 20 hours; and / or the method further comprises a post-treatment step, which includes separation and impurity removal.

8. The lubricating oil according to any one of claims 1 to 7, characterized in that The rotating oxygen bomb time of the lubricating oil at 150° C. is greater than 2000 min; and / or the wear spot diameter of the lubricating oil is less than 0.45 mm.

9. A method for preparing the lubricating oil according to any one of claims 1 to 8, characterized in that: include: The additive is added into a stirring kettle, stirred at 40-80° C. and a rotation speed of 100-300 rpm for 60-120 minutes, and cooled to obtain an additive mixed liquid; the additive mixed liquid is mixed with base oil, stirred at 40-80° C. and a rotation speed of 100-500 rpm for 60-120 minutes, cooled and filtered to obtain the lubricating oil.

10. Use of the lubricating oil according to any one of claims 1 to 9 as a bearing and / or gear lubricating oil at -40 to 150°C.

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