Ultra-long mileage total-synthesis heavy-load national 6b diesel engine oil composition and preparation method thereof

Abstract

The invention discloses an ultra-long mileage total-synthesis heavy-load national 6b diesel engine oil composition and a preparation method of the ultra-long mileage total-synthesis heavy-load national 6b diesel engine oil composition. Comprising the following raw materials in percentage by mass: 1%-5% of an antioxidant and anti-wear agent, 1.0%-5.0% of a metal detergent, 1.0%-15% of an ashless dispersant, 0.1%-0.5% of an antifriction and anti-wear agent, 5.0%-15.0% of a viscosity index improver, 0.1%-0.8% of a pour point depressant and 60%-92% of base oil. The lubricating oil is reasonable in formula and scientific and reasonable in formula, meets the lubricating core requirement of one-long-body, two-resistance and three-low, and finally achieves deep synergy of the lubricating oil, high detonation pressure, EGR and a post-processing system through engine oil integration development.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lubricating oil, in particular to a full synthetic heavy-duty national standard VI B diesel engine oil composition and a preparation method thereof. BACKGROUND

[0002] The national standard VI B emission standard is more stringent than the national standard VI A, and the operation stability, exhaust temperature and catalytic effect of the heavy-duty engine at low load are also higher. In order to meet the requirements of the emission standard, commercial vehicle manufacturers need to make more in-depth technical innovation and transformation, and adopt more efficient powertrains, catalytic converters, fuel systems and other new technologies. In terms of lubricating oil demand, it mainly reflects in several aspects: high temperature stability and oxidation resistance, the piston ring groove temperature is above 290 DEG C, the lubricating oil coking temperature is required to be > 300 DEG C, the peak temperature of the turbocharger vortex end bearing is 280 DEG C, and the oil sludge and carbon deposition caused by high temperature oxidation need to be inhibited. The oil change cycle is extended to 150-200 thousand kilometers, high load and wear resistance are required, the burst pressure is increased to 250-300 bar, the oil film strength and extreme pressure protection of the moving pair (piston ring-cylinder sleeve, bearing bush, etc.) are required to be stronger; adapt to low friction coating technology to avoid the conflict between coating and additive. Cleanliness and dispersion deposit control, inhibit the carbon deposition of the piston top / ring groove and the cylinder liner film; have high soot handling capacity, the EGR rate increases to cause the increase of soot content, the dispersion agent needs to be strengthened to prevent the filter screen from being blocked and worn due to soot agglomeration. The requirement of ultra-low ash and sulfur and phosphorus limitation reduces the DPF blockage; the requirement of strong acid neutralization capacity introduces acidic substances (NO x / SO x ) by EGR, high base reserve is required. The requirement of fuel economy and low viscosity adaptation reduces the friction technology of low viscosity oil, needs to match the friction reduction design (such as low elastic force piston ring, electric control pump), increases the friction modifier (FM), and optimizes the boundary lubrication performance. It also needs to resist fuel dilution, the diesel mixed by DPF regeneration cycle, and the lubricating oil needs to have strong oil film maintaining capacity. SUMMARY

[0003] The present application aims to provide a full synthetic heavy-duty national standard VI B diesel engine oil composition and a preparation method thereof, which has a scientific and reasonable formula and meets the lubricating core requirements of "one long two resistance three low": one long: 150-200 thousand kilometers of super long oil change cycle; two resistance: high temperature oxidation resistance (> 300 DEG C), wear resistance; three low: low sulfur (≤0.4%), low phosphorus (≤0.12%), ash content (≤0.8%), low fuel dilution risk. Finally, through "oil integration" development, the lubricating oil and high burst pressure, EGR and aftertreatment system are deeply coordinated.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0005] An ultra-long mileage full-synthetic heavy-duty Guo Liub diesel engine oil composition, comprising the following raw materials:

[0006] An antioxidant and anti-wear agent with a mass content of 1%-5%;

[0007] A metal detergent with a mass content of 1.0%-5.0%;

[0008] An ashless dispersant with a mass content of 1.0%-15%;

[0009] A friction-reducing and anti-wear agent with a mass content of 0.1%-0.5%;

[0010] A tackifier with a mass content of 5.0%-15.0%;

[0011] A pour point depressant with a mass content of 0.1%-0.8%;

[0012] A base oil with a mass content of 60%-92%;

[0013] The antioxidant and anti-wear agent is zinc diaryl dithiophosphate, an oligomer synthetic arylamine type antioxidant, and a long-chain alkyl thio hindered phenol, and the mass ratio is (0.5-1.0):(1.0-2.0):(1.0-2.0).

[0014] The metal detergent is an alkyl salicylate and a sulfidized alkyl phenate mixed in a mass ratio of (0.5-2.0):(0.5-2.0).

[0015] Preferably, the ashless dispersant is a boronized polyisobutylene succinimide type dispersant.

[0016] Preferably, the friction-reducing and anti-wear agent is a molybdenum dialkyldithiocarbamate.

[0017] Preferably, the tackifier is a 4-pyridine ethylpropylene polymer tackifier.

[0018] Preferably, the pour point depressant is a polymethacrylate.

[0019] Preferably, the base oil is selected from the group consisting of Group III paraffin-based synthetic oil (consisting of 250N and 150N).

[0020] Preferably, the structure of the zinc diaryl dithiophosphate is preferably shown in Formula I:

[0021]

[0022] Formula I

[0023] Preferably, the structure of the long-chain alkyl thio hindered phenol is preferably shown in Formula II:

[0024]

[0025] Formula II

[0026] Preferably, the alkyl salicylate has a structure preferably as shown in Formula III:

[0027]

[0028] Formula III

[0029] wherein R is an alkyl group containing 10-20 carbon atoms, M is Ca or Mg, and m, n are positive integers not equal to zero.

[0030] Preferably, the sulfurized alkyl phenate has a structure preferably as shown in Formula IV:

[0031] ;

[0032] Formula IV

[0033] wherein R2 is an alkyl group containing 10-24 carbon atoms, M is Ca or Mg, and m2, n2, x are positive integers not equal to zero.

[0034] Preferably, the boronized polyisobutylene succinimide dispersant has a structure as shown in Formula V:

[0035] ;

[0036] Formula V

[0037] wherein PIB is polyisobutylene, the molecular weight is 900-1300, and r is a positive integer not equal to zero.

[0038] Preferably, the molybdenum dialkyldithiocarbamate has a structure as shown in Formula VI:

[0039]

[0040] Formula VI

[0041] wherein R = C n H 2n+1 , and n = 4-12.

[0042] Preferably, the pour point depressant is a polymethacrylate having a structure as shown in Formula VII:

[0043]

[0044] Formula VII

[0045] wherein R = C n H 2n+1 , and n = 10-20.

[0046] The low polymer synthesis arylamine type antioxidant is alkylated N-phenyl-alpha-naphthylamine and alkylated diphenylamine in a polyhydric alcohol ester solvent, and through the initiation of an initiator, chemical reaction of the reaction raw materials occurs under the condition of a reaction temperature of 135 DEG C to 185 DEG C, and through nitrogen gas, after reaction for 6 to 10 hours, red-brown viscous low polymer synthesis arylamine type antioxidant is obtained through reduced pressure distillation.

[0047] The application also provides a preparation method of the super-long mileage full-synthetic heavy-duty national VI B diesel engine composition.

[0048] 1) Sol: according to the formula proportion, first mix the tackifier block with the appropriate base oil, heat to 125-135 DEG C, stir and dissolve, stand for 4-6 hours, and obtain product a;

[0049] 2) Compound: put product a and the remaining base oil into a blending kettle, and according to the formula proportion, sequentially add ashless dispersant, antioxidant and anti-wear agent, metal detergent, and anti-wear agent, start stirring, heat to 50-60 DEG C and keep warm, continuously stir for 2-4 hours, and obtain product b;

[0050] 3) Blend: finally, add a pour point depressant to product b, the stirring temperature is 50-60 DEG C, continuously stir for 2-4 hours, and the super-long mileage full-synthetic heavy-duty national VI B diesel engine composition is prepared.

[0051] Compared with the prior art, the application has the following technical advantages:

[0052] (1) The arylamine antioxidant is a high-efficiency radical terminator, and has excellent high-temperature antioxidant performance, outstanding ability to control the viscosity growth of oil products and high-temperature antioxidant performance. The antioxidant mechanism of alkylated diphenylamine is that alkylated diphenylamine generates amino radical at high temperature, and captures peroxide to form nitrogen-oxygen radical. The radical is subjected to molecular rearrangement to regenerate alkylated diphenylamine at high temperature. In addition to fast hydrogen supply, alkyl N-phenyl-alpha-naphthylamine can also generate stable substances. The high-temperature antioxidant effect of alkylated diphenylamine is weaker than that of alkyl N-phenyl-alpha-naphthylamine, but the oxidation product of alkylated diphenylamine is not easy to deposit into oil sludge. The antioxidant performance of alkyl N-phenyl-alpha-naphthylamine is stronger than that of alkylated diphenylamine, but it is easy to produce oil sludge. Therefore, the oligomer synthetic arylamine antioxidant is synthesized by reaction of alkylated N-phenyl-alpha-naphthylamine and alkylated diphenylamine, and has the advantages of both. The benzene ring and naphthalene ring in the structural formula form a larger π-electron conjugated system, the reaction ability of N-H bond with oxygen radical is enhanced, the electron delocalization effect makes the whole molecule form a stable radical after losing H, thereby reducing the oxidation rate of oil products, and the oligomer synthetic arylamine antioxidant has higher thermal stability (naphthalene ring conjugation is enhanced) than the monomer. In addition, the oligomer synthetic arylamine antioxidant has an alkyl chain (such as C8-C12) in the structure, which provides good oil solubility and avoids the problem of precipitation after oxidation of the monomer, and has the function of regenerating the antioxidant. The oligomer synthetic arylamine antioxidant overcomes the defects of the monomer, has higher thermal decomposition temperature and oxidation stability, has more outstanding antioxidant performance than conventional antioxidants, and can meet the antioxidant performance requirements of oil products under high-temperature working conditions.

[0053] (2) Compared with amine antioxidants, phenolic antioxidants have the best effect at low temperatures below 150°C, are more compatible with base oils, do not produce precipitation, and have stronger activity at low temperatures. Due to the limitation of the post-processing system on phosphorus, the amount of zinc dialkyldithiophosphate (ZDDP) needs to be controlled in the formula, and an additive with peroxide decomposition function needs to be supplemented. Due to the deep processing process, the natural sulfur component is missing in synthetic base oil, and synthetic base oil has good sensitivity to sulfur-containing antioxidants. Therefore, long-chain alkyl hindered phenolic antioxidants are preferred. The sulfur-containing hindered phenolic antioxidant containing a thioether group antioxidant functional group can not only terminate the chain oxidation reaction of hydrocarbon molecules by reacting with ROO· through phenolic hydroxyl group homolysis dehydrogenation, but also can decompose ROOH into ROH through the thioether group, thereby producing a self-synergistic antioxidant effect, so that the sulfur-containing hindered phenolic antioxidant has better antioxidant activity than the sulfur-free phenolic antioxidant. A C9 alkyl long chain is introduced at the para position of the hydroxyl group of the long-chain alkyl hindered phenolic antioxidant to increase the relative molecular mass and reduce the volatility. This long chain is like an "arm" of a monophenol, which can control the solubility and volatility of the antioxidant and improve the anti-aging efficiency. The long-chain alkyl hindered phenolic antioxidant has the dual functions of inhibiting oxidation chain reaction of the main antioxidant and decomposing hydroperoxide of the auxiliary antioxidant.

[0054] (3) Long chain alkyl thio hindered phenolic antioxidant can reduce the formation of deposits, amine antioxidant can effectively control the viscosity growth, and the two have good synergistic effect. The reaction rate of oligomer synthetic arylamine antioxidant with alkyl peroxide radical is faster than that of long chain alkyl thio hindered phenolic antioxidant, and the long chain alkyl thio hindered phenolic antioxidant provides hydrogen atoms for the regeneration of amine from the free radical of oligomer synthetic arylamine, that is, through the transfer of active hydrogen (H), the long chain alkyl thio hindered phenolic antioxidant with relatively weak activity is sacrificed, so that the oligomer synthetic arylamine antioxidant with relatively strong activity can be regenerated.

[0055] (4) Zinc diaryl dithiophosphate (usually refers to aryl as aromatic hydrocarbon) is used as antioxidant and anti-wear agent, compared with zinc dialkyl dithiophosphate (usually refers to alkyl chain as aliphatic hydrocarbon), the benzene ring conjugated system on aryl ZDDP makes the molecule more stable, and the C-O bond (connecting aryl and oxygen) is stronger than that in alkyl ZDDP. This makes aryl ZDDP decompose more slowly at high temperature (> 150°C), and aryl ZDDP can provide antioxidant protection more persistently; at the same time, steric hindrance and electronic effect make aryl ZDDP more difficult to be attacked by water and hydrolyzed, so that the phosphorus in the molecular structure remains very well. For long-life engine oil that needs to control phosphorus content to meet emission regulations (protect catalyst), aryl ZDDP has more advantages, so this patent selects zinc diaryl dithiophosphate as antioxidant and anti-wear agent.

[0056] As a peroxide decomposer, the sulfur atom in the molecule of zinc diaryl dithiophosphate (ZDDP) has strong nucleophilicity, can attack and decompose organic hydroperoxide produced in the oxidation process of lubricating oil, convert it into relatively inert substances such as alcohol, and at the same time, itself is oxidized into various complex sulfur-containing and phosphorus-containing oxidation products (such as sulfate, phosphate, etc.), interrupting the key link (ROOH decomposition producing new free radicals RO· and ROO·) in the free radical chain reaction, significantly slowing down the further oxidation of the oil.

[0057] Zinc diaryl dithiophosphate (ZDDP) also acts as a free radical terminator in the reaction, and ZDDP and its thermal decomposition / oxidation products can capture alkyl radicals and alkoxy radicals produced in the oxidation process of lubricating oil. The S or P atoms in the ZDDP molecule can provide electrons or hydrogen atoms to react with free radicals to generate more stable substances, thereby terminating the free radical chain reaction.

[0058] Zinc diaryl dithiophosphate (ZDDP) can form an adsorption film or a reaction film on the surface of metal (such as copper, iron), preventing metal ions (especially copper ions) from dissolving into the oil. Dissolved metal ions are strong oxidation catalysts (catalyzing the decomposition of ROOH), so passivating the metal surface indirectly inhibits the oxidation process.

[0059] (5) Long-chain alkyl thio hindered phenol and oligomer synthesis arylamine antioxidant as free radical terminator and peroxide radical reaction, prevent the free radical chain transmission and growth, and zinc diaryl dithiophosphate (ZDDP) as a hydrogen peroxide decomposer, prevent the chain branching reaction, both synergistic, at the same time break the chain growth and chain branching reaction of chain reaction, avoid the mutual causality and mutual catalysis of free and peroxidation, and the cyclic reaction.

[0060] (6) Molybdenum dialkyldithiocarbamate (MoDTC) has the dual function of friction modifier + antioxidant, molybdenum dialkyldithiocarbamate (MoDTC) is decomposed into nanometer molybdenum disulfide (MoS2) on the friction surface, forming a layered solid lubricating film; as a peroxide decomposer, the decomposition product molybdate catalyzes the decomposition of hydrogen peroxide (ROOH), interrupting the free radical chain reaction. Molybdenum dialkyldithiocarbamate has a synergistic effect with long-chain alkyl thio hindered phenol and oligomer synthesis arylamine antioxidant. Molybdenum dialkyldithiocarbamate can provide a sulfur source, and zinc diaryl dithiophosphate has a synergistic effect in reducing engine wear. The two complement each other in film formation, forming a double-layer protective barrier, zinc diaryl dithiophosphate (ZDDP) forms a phosphate glass film, the film structure is amorphous and high hardness, which plays a role in anti-extrusion, preventing micro-point corrosion, and adding more becomes an extrusion agent, that is, the reason, as the bottom layer to bear high impact load; while molybdenum dialkyldithiocarbamate (MoDTC) generates a layered molybdenum disulfide film, the film structure is hexagonal, low shear strength, which plays a role in super sliding and friction reduction, providing a sliding interface in the upper layer, reducing friction heat and reducing the friction coefficient of the engine friction pair. In the field of tribology, it has a synergistic effect of catalytic activation and film regeneration, MoO3 produced by pyrolysis of molybdenum dialkyldithiocarbamate (MoDTC) catalyzes the hydrolysis of zinc diaryl dithiophosphate (ZDDP), accelerating the formation of zinc phosphate film, and the zinc phosphate film formed by zinc diaryl dithiophosphate (ZDDP) fills the surface microcracks, providing a flat substrate for MoS2, stabilizing the MoS2 film and prolonging its service life.

[0061] (7) The polymer chains in the 4-pyridine ethylene propylene polymer viscosity index agent extend at high temperatures (increasing hydrodynamic volume) and coil at low temperatures (reducing flow resistance), balancing viscosity-temperature performance. The ethylene propylene segments (high C / C bond energy) can resist mechanical shearing, maintaining the stability of engine oil viscosity and engine oil pressure. The pyridine group (nitrogen-containing heterocycle) electrostatically adsorbs and binds to the carboxyl groups (-COOH, Lewis acid) on the soot surface through charge interaction and hydrogen bonding. The sterically hindered polymer chains encapsulate soot particles, preventing aggregation (particle size control <1μm). At the same time, the pyridine group can capture free radicals and delay polymer chain scission. For high EGR rate China VI b engines that produce a large amount of soot, the 4-pyridine ethylene propylene polymer viscosity index agent can inhibit viscosity growth and avoid "oil thickening" faults. 4-Pyridine ethylene propylene polymer viscosity index agent can disperse antioxidants and anti-wear agents, as well as friction-reducing and anti-wear agents and their own oxidation products, thereby improving antioxidant efficiency. Antioxidants and anti-wear agents can improve the thermal stability of 4-pyridine ethylene propylene polymer viscosity index agent and prevent thermal oxidation chain scission, thus exhibiting a synergistic effect.

[0062] (8) Detergent compound (high-alkalinity alkyl salicylate magnesium + high-alkalinity alkylphenol calcium sulfate): High-alkalinity alkyl salicylate magnesium can instantly neutralize explosive acids. Its salicylic acid aromatic ring structure can adsorb soot, promote the microcrystallization of deposits, form a dense metal soap film to isolate oxidation products, promote the decomposition of hydrogen peroxide, block the oxidation chain reaction, and generate a friction polymerization film under boundary lubrication to repair micro-scratches. High-alkalinity alkylphenol calcium sulfate can provide long-term neutralization protection. Its CaCO3 colloidal nucleus can physically abrade the deposit layer, alkylphenol sulfate can inhibit high-temperature polymerization, phenolic free radicals can terminate the oxidation chain reaction, and can also transfer some heat, reduce the ignition point of micelle CaCO3, thereby reducing the risk of low-speed pre-ignition. Under boundary lubrication, the sulfide groups decompose to form a FeS anti-wear film. The synergistic effect of the two enhances the acid neutralization ability, achieves a breakthrough in high-temperature cleaning performance, and also synergistically improves the antioxidant and anti-wear properties. Attached Figure Description

[0063] Figure 1 This is a result diagram of the crankcase simulation test in Example 3, where the adhesive weight is 5.0 mg.

[0064] Figure 2 This is a result diagram of the crankcase simulation test in Example 4, where the adhesive weight is 6.0 mg.

[0065] Figure 3 This is the result graph of the crankcase simulation test in Comparative Example 1, where the adhesive weight is 15.9 mg.

[0066] Figure 4 This is the result graph of the crankcase simulation test in Comparative Example 2, where the adhesive weight is 9.0 mg.

[0067] Figure 5 This is the result diagram after the engine oil thermal stability test in Example 3. The score is 9 points, and the score ranges from 0 to 9, indicating that the cleaner the glass tube, the higher the score.

[0068] Figure 6 This is the result diagram after the engine oil thermal stability test in Example 4, with a score of 8 points;

[0069] Figure 7 This is a graph showing the results of the engine oil thermal stability test in Comparative Example 1, with a score of 5 points.

[0070] Figure 8 This is the result diagram of the engine oil thermal stability test in Comparative Example 2, with a score of 6 points.

[0071] Figure 9 This is a graph showing the rate of change of KV100 viscosity;

[0072] Figure 10 This is a graph showing the change in oxidation value;

[0073] Figure 11 This is a graph showing the changes in smoke intensity;

[0074] Figure 12 This is a graph showing the variation of Fe element. Detailed Implementation

[0075] Before further describing 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 embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention.

[0076] Examples 1-4 and Comparative Examples 1-2

[0077] A fully synthetic heavy-duty diesel engine oil composition suitable for ultra-long mileage and heavy load (China VI b standard) is provided. The composition and content of its raw materials are shown in Table 1, calculated by mass percentage based on the total mass of the diesel engine oil.

[0078] Differences between the examples and the comparative examples:

[0079] 1. The formulation differs from Example 1. Example 2 reduces the amount of detergent magnesium alkyl salicylate and calcium sulfide alkylphenol, increases the amount of dispersant boronized polyisobutylene succinimide, and increases the amounts of antioxidant and anti-wear agents zinc diaryldithiophosphate, oligomer synthetic amine antioxidant, and long-chain alkylthiohedral phenol. The preparation method of the ultra-long mileage fully synthetic heavy-duty China VI b diesel engine composition is the same as in Example 1, including the following steps:

[0080] 1) Sol: According to the formula ratio, first mix the adhesive block with an appropriate amount of base oil, heat to 126℃ and stir to dissolve, let stand for 6 hours to obtain product a;

[0081] 2) Compounding: Place product a and the remaining base oil into a mixing tank, and add dispersant, antioxidant and anti-wear agent, detergent and friction-reducing and anti-wear agent in sequence according to the formula ratio. Start stirring and heat to 51°C and keep warm. Continue stirring for 4 hours to obtain product b.

[0082] 3) Blending: Finally, add the pour point depressant to product b, stir at 50°C for 4 hours.

[0083] 2. The formulation differs from Example 2; Example 3 increases the amount of 4-pyridine ethylene propylene polymer adhesive indexer. The preparation method of the ultra-long mileage fully synthetic heavy-duty China VI b diesel engine composition is the same as in Example 1, including the following steps:

[0084] 1) Sol: According to the formula ratio, first mix the viscosity index block with an appropriate amount of base oil, heat to 132℃ and stir to dissolve, let stand for 5 hours to obtain product a;

[0085] 2) Compounding: Place product a and the remaining base oil into a mixing tank, and add dispersant, antioxidant and anti-wear agent, detergent and friction-reducing and anti-wear agent in sequence according to the formula ratio. Start stirring and heat to 56°C and keep warm. Continue stirring for 3 hours to obtain product b.

[0086] 3) Blending: Finally, add the pour point depressant to product b, stir at 55℃ for 3 hours.

[0087] 3. The formulation differs from Example 3. Example 4 increases the amount of boronized polyisobutylene succinimide dispersant, and increases the amounts of zinc diaryldithiophosphate, oligomerized amine antioxidant, and long-chain alkyl thiohedral phenol antioxidant; it also decreases the amount of 4-pyridine ethylene propylene polymer viscosity index agent. The preparation method of the ultra-long mileage fully synthetic heavy-duty China VI b diesel engine composition is the same as in Example 1, including the following steps:

[0088] 1) Sol: According to the formula ratio, first mix the adhesive block with an appropriate amount of base oil, heat to 134℃ and stir to dissolve, let stand for 4 hours to obtain product a;

[0089] 2) Compounding: Place product a and the remaining base oil into a mixing tank, and add dispersant, antioxidant and anti-wear agent, detergent and friction-reducing and anti-wear agent in sequence according to the formula ratio. Start stirring and heat to 59°C and keep warm. Continue stirring for 2 hours to obtain product b.

[0090] 3) Blending: Finally, add the pour point depressant to product b, stir at 60℃ for 2 hours.

[0091] 4. The formulation differs from Example 3. In Comparative Example 1, alkyl diphenylamine was used to replace the oligomer-synthesized amine antioxidant. The preparation method of the ultra-long mileage fully synthetic heavy-duty China VI b diesel engine composition is basically the same as in Example 3.

[0092] 5. The formulation differs from Example 3. In Comparative Example 2, an ethylene-propylene polymer adhesive indexer was used instead of the 4-pyridine ethylene-propylene polymer adhesive indexer. The preparation method of the ultra-long mileage fully synthetic heavy-duty China VI b diesel engine composition is basically the same as in Example 3.

[0093]

[0094] In Table 1:

[0095] The structural formula of the diaryl dithiophosphate zinc is shown in Formula I:

[0096]

[0097] Formula I

[0098] The structural formula of the long-chain alkyl thiohed phenol is shown in Formula II:

[0099]

[0100] Formula II

[0101] The structure of the boronized polyisobutylene succinimide dispersant is shown in Formula V:

[0102] ;

[0103] Formula V

[0104] Wherein, PIB stands for polyisobutylene, and r is a non-zero positive integer.

[0105] The structure of the dialkyldithiocarbamate molybdenum is shown in Formula VI:

[0106]

[0107] Formula VI

[0108] In the formula, R = C n H 2n+1 .

[0109] The pour point depressant is a polymethacrylate with the structure shown in Formula VI:

[0110]

[0111] Formula VII

[0112] In the formula, R = C n H 2n+1 .

[0113] The oligomer-synthesized aromatic amine antioxidant is prepared by reacting alkylated N-phenyl-α-naphthylamine and alkylated diphenylamine in a polyol ester solvent under inert nitrogen gas at a reaction temperature of 160°C. The reactants undergo a chemical reaction initiated by an initiator. After 8 hours of reaction, the mixture is distilled under reduced pressure to obtain a reddish-brown viscous oligomer-synthesized amine antioxidant.

[0114] The physicochemical test indicators of the embodiments and comparative examples of this invention are shown in Table 2, the physicochemical index table of the lubricating oil composition. As can be seen from Table 2, each scheme belongs to the low-sulfur, low-phosphorus, and low-ash schemes, protecting the after-treatment system of the China VI b diesel engine. Both the embodiments and comparative examples are designed with high base number and low ash content to meet the acid neutralization requirements. Using Group III paraffinic synthetic oil results in very low evaporation losses, thus achieving low oil consumption and saving customers money. The high-temperature high-shear viscosity of Examples 1-4 is higher than that of Comparative Example 1, with Example 3 showing the highest viscosity. This indicates that the use of 4-pyridine ethylene propylene polymer viscosity indexer results in a larger oil film at high temperatures than that of ethylene propylene polymer viscosity indexer, ensuring the engine's oil pressure.

[0115]

[0116] II. Simulated Performance Testing of Oil Products

[0117] Simulated performance tests were conducted using both the implementation examples and comparative examples. The test results are shown in Table 3.

[0118]

[0119] Table 3 shows the simulation performance test results, with Example 3 exhibiting the best performance. Although Example 4 had a higher dosage of antioxidant and anti-wear agent than Example 3, the simulation performance test results indicate that the raw material combination in Example 3 was optimal, and the performance of each individual agent was well utilized. Figures 1-8 It can be seen that the results of Comparative Example 1 in the crankcase simulation test and thermal oxidation simulation test are significantly worse than those of Example 3, indicating that the 4-pyridine ethylene propylene polymer viscosity index agent has excellent deposit dispersion performance at high temperatures. The results of Comparative Example 2 in the oxidation induction period, rotating oxygen bomb, and propellant thermal stability tests are significantly worse than those of Example 3, indicating that the oligomer-synthesized amine antioxidant overcomes the defects of monomers, has a higher thermal decomposition temperature and oxidation stability, and has more outstanding antioxidant performance than conventional antioxidants, which can meet the antioxidant performance requirements of oil products under the high-temperature conditions of China VI b diesel engines.

[0120] III. Bench Performance Testing of Oil Products

[0121] 1. A reliability bench test of the YCA08280 engine was conducted on Example 3 and Comparative Example 1. By increasing the soot content under the designed operating conditions, the soot dispersion performance of the oil was examined.

[0122]

[0123] The high molecular weight viscosity index (VPI) compounds in engine oil will break down and degrade under the mechanical force and high temperature of the engine, and the kinematic viscosity at 100°C will decrease. As can be seen from the results of the high soot engine bench test in Table 4, the two bench test conditions are the same and the amount of soot produced is the same. However, the changes in kinematic viscosity at 100°C are different between Example 3 and Comparative Example 1. The kinematic viscosity at 100°C of Example 3 gradually decreases, while the kinematic viscosity at 100°C of Comparative Example 1 gradually increases. This indicates that Example 3 has the best soot dispersion performance and can disperse large soot particles into small soot particles in the oil, thereby preventing the viscosity from increasing. At the same time, judging from the oxidation value and nitration value data, the antioxidant performance of Example 3 is better than that of Comparative Example 1.

[0124] 2. A 150,000-kilometer road test was conducted on Example 3 to examine the reliability of the fuel. A total of three vehicles participated in the road test. The test results are as follows: Figure 1 .

[0125] from Figures 9-12 The test results show that after 150,000 kilometers of actual road conditions, no abnormalities were found in the KV100 of the engine oil, as well as in the indicators such as soot, oxidation value, and iron wear. This indicates that Example 3 can meet the technical requirements of the 150,000-kilometer oil change period for China VI b diesel engines.

[0126] The above are merely specific embodiments of the present invention. It should be noted that the rest, which are not described in detail, are prior art. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A long-mileage fully synthetic heavy-duty China VI b diesel engine oil composition, characterized in that, Including the following raw materials: Antioxidant and anti-wear agent with a mass content of 1%-5%; Metal cleaning agent with a mass content of 1.0%-5.0%; Ashless dispersant with a mass content of 1.0%-15%; Friction-reducing and wear-resistant agents with a mass content of 0.1%-0.5%; Adhesive finger binder with a mass content of 5.0%-15.0%; Pour point depressant with a mass content of 0.1%-0.8%; Base oils with a mass content of 60%-92%; The antioxidant and anti-wear agent is composed of zinc diaryl dithiophosphate, oligomer-synthesized aromatic amine antioxidant, and long-chain alkyl thiohedral phenol in a mass ratio of (0.5-1.0): (1.0-2.0): (1.0-2.0). The metal cleaning agent is a mixture of alkyl salicylate and sulfide alkylphenol salt in a mass ratio of (0.5-2.0):(0.5-2.0).

2. The ultra-long mileage fully synthetic heavy-duty China VI b diesel engine oil composition according to claim 1, characterized in that, The ashless dispersant is a boronized polyisobutylene succinimide dispersant; The structural formula of the boronized polyisobutylene succinimide dispersant is shown below: ； Wherein, PIB stands for polyisobutylene, with a molecular weight of 900-1300, and r is a non-zero positive integer.

3. The ultra-long mileage fully synthetic heavy-duty China VI b diesel engine oil composition according to claim 1, characterized in that, The friction-reducing and wear-resistant agent is molybdenum dialkyldithiocarbamate; The structural formula of the dialkyldithiocarbamate molybdenum is shown below: In the formula, R = C n H 2n+1 , n = 4 - 12.

4. The ultra-long mileage fully synthetic heavy-duty China VI b diesel engine oil composition according to claim 1, characterized in that, The adhesive finger agent is a 4-pyridine ethylene propylene polymer adhesive finger agent.

5. The ultra-long mileage fully synthetic heavy-duty China VI b diesel engine oil composition according to claim 1, characterized in that, The pour point depressant is polymethacrylate, and the structural formula of the polymethacrylate is shown below: In the formula, R = C n H 2n+1 , n = 10 - 20.

6. The ultra-long mileage fully synthetic heavy-duty China VI b diesel engine oil composition according to claim 1, characterized in that, The base oil is selected from Group III paraffinic synthetic oils.

7. The ultra-long mileage fully synthetic heavy-duty China VI b diesel engine oil composition according to claim 1, characterized in that, The structural formula of the diaryl dithiophosphate zinc is shown below: ； The structural formula of the long-chain alkyl thiohed phenol is shown below: 。 8. The ultra-long mileage fully synthetic heavy-duty China VI b diesel engine oil composition according to claim 1, characterized in that, The structural formula of the alkyl salicylate is shown below: ； Where R is an alkyl group containing 10-20 carbon atoms, M is Ca or Mg, and m and n are non-zero positive integers; The structural formula of the sulfurized alkylphenol salt is shown below: ； In the formula, R2 is an alkyl group containing 10-24 carbon atoms, M is Ca or Mg, and m2, n2, and x are non-zero positive integers.

9. The ultra-long mileage fully synthetic heavy-duty China VI b diesel engine oil composition according to claim 1, characterized in that, The oligomer-synthesized aromatic amine antioxidant is obtained by reacting alkylated N-phenyl-α-naphthylamine and alkylated diphenylamine in a polyol ester solvent, under inert nitrogen gas, at a reaction temperature of 135℃-185℃. The reactants undergo a chemical reaction initiated by an initiator. After 6-10 hours of reaction, the oligomer-synthesized amine antioxidant is obtained by vacuum distillation.

10. A method for preparing an ultra-long mileage fully synthetic heavy-duty China VI b diesel engine composition according to any one of claims 1-9, characterized in that, Includes the following steps: 1) Sol: Mix the adhesive block with an appropriate amount of base oil according to the formula ratio, heat to 125-135℃ and stir to dissolve, let stand for 4-6 hours to obtain product a; 2) Compounding: Place product a and the remaining base oil into a mixing tank, and add ashless dispersant, antioxidant and anti-wear agent, metal detergent and friction-reducing and anti-wear agent in sequence according to the formula ratio. Start stirring and heat to 50℃-60℃ and keep warm. Continue stirring for 2-4 hours to obtain product b. 3) Blending: Finally, add pour point depressant to product b, stir at 50℃-60℃ for 2-4 hours to obtain the ultra-long mileage fully synthetic heavy-duty China VI b diesel engine composition.

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