Gasoline engine oil composition and base oil molecule modification method thereof

Abstract

The invention relates to the technical field of base oil molecular structure modification, in particular to a gasoline engine oil composition and a base oil molecular modification method thereof, the composition contains 70-85 parts of modified base oil, 5-10 parts of boric acid ester dispersing agent and other additives; when the modified base oil is prepared, the base oil firstly reacts with 3-mercaptopropyltrimethoxysilane, then glycidyl methacrylate and N-vinyl pyrrolidone are sequentially added, a multi-step temperature control reaction is carried out, siloxane groups, epoxy groups and pyrrolidone groups are grafted on molecular chains, and the modified base oil is obtained and used for preparing high-performance gasoline engine oil. Through base oil molecule modification and special additive compounding, the viscosity-temperature performance, the wear resistance and the oxidation stability of the gasoline engine oil are improved, and sediment generation is reduced; the process reduces energy consumption and cost, meets environmental protection requirements, and realizes unification of high performance and economical efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of base oil molecular structure modification, in particular to a gasoline engine oil composition and a base oil molecular modification method thereof. Background Art

[0002] In the modern automotive industry, the performance of gasoline engine oil directly impacts the engine's service life and fuel economy. Traditional gasoline engine oils are often formulated with mineral base oils and conventional additives. These base oils have a simple molecular structure and are susceptible to oxidative cracking under high-temperature, high-load conditions, resulting in decreased oil viscosity, increased deposits, and shortened oil change intervals. While conventional additive systems can provide basic lubrication and antioxidant properties, they struggle to meet the comprehensive requirements for wear resistance, anti-foaming, and low-temperature fluidity in the harsh operating environments brought about by technologies like engine miniaturization and turbocharging. For example, traditional diphenylamine antioxidants decompose rapidly at high temperatures and are unable to provide long-term protection for the oil. Polyisobutylene-based dispersants have limited sludge dispersion capabilities, which can easily lead to carbon deposits within the engine.

[0003] Existing base oil modification technologies have limitations. Improving base oil quality through hydroisomerization is expensive and difficult to alter at the molecular level. Simple physical mixing of additives fails to form a stable synergistic network, leading to significant performance degradation over long-term engine oil use. Furthermore, with increasingly stringent environmental regulations on engine oil volatility and phosphorus content, traditional formulations struggle to maintain high performance while minimizing environmental impact.

[0004] While emerging nanomaterials and ionic liquids have been explored for use in lubricants, large-scale application has yet to be achieved due to poor dispersibility, high costs, and limited compatibility with base oils. For example, unmodified graphene tends to aggregate in oil, exacerbating mechanical wear; and the high viscosity of ionic liquids can significantly increase engine resistance. Therefore, there is an urgent need to develop molecular modification and formulation solutions for gasoline engine oils that balance performance enhancement with cost optimization. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the deficiencies of the prior art, the present invention provides a gasoline engine oil composition and a method for modifying the base oil molecules thereof.

[0007] (2) Technical solution

[0008] A gasoline engine oil composition, comprising the following components in parts by weight: 70-85 parts of a molecularly modified base oil, 5-10 parts of a borate ashless dispersant, 3-6 parts of zinc dialkyl dithiophosphate, 2-5 parts of an aromatic amine antioxidant, 4-8 parts of a methacrylate viscosity index improver, and 0.5-1.5 parts of a benzotriazole derivative metal deactivator;

[0009] The molecularly modified base oil is prepared by the following method: mixing the base oil with 3-mercaptopropyltrimethoxysilane, heating to 150-180° C. under nitrogen protection, adding dibutyltin dilaurate as a catalyst for reaction, then adding glycidyl methacrylate and continuing the reaction, and finally adding N-vinylpyrrolidone and reacting at 80-100° C. to obtain a modified base oil having siloxane groups, epoxy groups, and pyrrolidone groups grafted onto the molecular chain. The chemical equation of the reaction is as follows:

[0010]

[0011]

[0012]

[0013] Preferably, 0.5-2 parts of graphene quantum dot additives are also included. The graphene quantum dots have a particle size of 2-8 nm, contain hydroxyl and carboxyl functional groups on the surface, and are uniformly dispersed in the base oil by ultrasonic dispersion.

[0014] Preferably, the invention further comprises 1-3 parts of an ionic liquid additive, wherein the ionic liquid is 1-butyl-3-methylimidazolium hexafluorophosphate, the purity of which is ≥99% and the moisture content is ≤0.05%.

[0015] Preferably, the borate ashless dispersant is polyisobutylene succinimide borate, which has a number average molecular weight of 1000-3000 and a boron content of 1.2-2.0 wt%.

[0016] Preferably, the aromatic amine antioxidant is a compound of octylated diphenylamine and N-phenyl-α-naphthylamine in a mass ratio of 2:1, and contains 0.5-1.5 wt % of nano-cerium dioxide synergist.

[0017] Preferably, the method for modifying the base oil molecules of the gasoline engine oil composition comprises the following steps:

[0018] S1: Heat the base oil to 100-120°C and dehydrate it under a vacuum of -0.08 to -0.1 MPa for 1-2 hours;

[0019] S2: Cool to 60-80°C, introduce nitrogen to replace the air three times, maintaining a positive nitrogen pressure of 0.02-0.03 MPa after each replacement; pre-dehydrate 3-mercaptopropyltrimethoxysilane at 40-50°C and vacuum of -0.09 MPa for 1 hour, then add it to the system under nitrogen protection; continue to introduce nitrogen for 30 minutes to ensure that the water content in the system is ≤50 ppm; then raise the temperature to 150-180°C;

[0020] S3: Add dibutyltin dilaurate catalyst, maintain the temperature for 4-6 hours, and apply 20-40kHz ultrasound during the reaction;

[0021] S4: Cooling to 120-140°C, adding glycidyl methacrylate, and then adding 0.1-0.3% of the total mass of the system with boron trifluoride etherate as an epoxy ring-opening catalyst, while introducing oxygen at a flow rate of 0.1-0.3 L / min·kg base oil, and continuing the reaction for 2-3 hours;

[0022] S5: Cooling again to 80-100°C, adding 0.5-1.0 parts of dibenzoyl peroxide as an initiator, stirring and dissolving; adding N-vinyl pyrrolidone in three batches, with an interval of 20 minutes between each batch, applying 0.2-0.3 MPa nitrogen pressure after each batch to suppress monomer volatilization, and maintaining it for 10 minutes; the initiator initiates polymerization and grafting of the double bonds of N-vinyl pyrrolidone with the residual active sites on the base oil molecular chain, and the reaction is carried out for 1-2 hours;

[0023] S6: After the reaction is completed, remove low-boiling substances at 120-140° C. and a vacuum degree of -0.09 to -0.1 MPa, filter through a 3-5 μm filter element, and filter at a filtration pressure of ≤0.3 MPa to obtain a modified base oil.

[0024] Preferably, the power density of the ultrasound in S3 is 0.5-1.5 W / cm², and is turned on for 5 minutes every 15 minutes.

[0025] Preferably, the oxygen in S4 is dried with a molecular sieve before being introduced, and the moisture content is ≤10 ppm.

[0026] Preferably, after each batch of N-vinyl pyrrolidone is added in S5, a nitrogen pressure of 1-2 MPa is immediately applied and maintained for 10 minutes.

[0027] Preferably, after the filtration in S6, the modified base oil is further subjected to a step of being treated in a strong magnetic field, wherein the magnetic field strength is 0.5-1.5 T and the treatment time is 30-60 minutes.

[0028] (3) Beneficial technical effects

[0029] Compared with the existing technology, the beneficial effects of the present invention are:

[0030] 1. Through grafting modification with siloxane, epoxy, and pyrrolidone groups, the base oil molecules form a three-dimensional network with polar adsorption and steric hindrance effects, increasing the viscosity index and enhancing high-temperature and high-shear viscosity, effectively improving the oil's film-forming stability under extreme operating conditions. The grafted functional groups, combined with borate ester and aromatic amine additives, form a composite antioxidant system that enhances oxidative stability, extending its life compared to traditional formulas and significantly reducing the oil's aging rate.

[0031] 2. Nanoscale graphene quantum dots are evenly dispersed in the oil, forming a nano-lubricating film that reduces the diameter of wear spots and significantly reduces engine friction losses. The low volatility and high polarity of the ionic liquid suppress foam generation to less than 10ml, while also minimizing oil evaporation losses. The modified base oil preparation process utilizes ultrasonic enhancement and staged temperature control to improve reaction efficiency while reducing energy consumption, resulting in lower production costs compared to hydrogenation processes. This solution achieves an optimal combination of high performance, long life, and low environmental impact, providing a new path for upgrading gasoline engine oil technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a flow chart of the method for modifying the base oil molecules of the gasoline engine oil composition disclosed in the present invention;

[0033] Figure 2 1. It is a broken line comparison diagram of kinematic viscosity and high temperature high shear viscosity of the embodiment and the comparative example;

[0034] Figure 3 1. is a graph comparing the weight of sediment and the growth of acid value of the embodiment and the comparative example;

[0035] Figure 4 This is a radar comparison chart made by quantizing the performance data of the embodiment and the comparative example. DETAILED DESCRIPTION

[0036] according to Figures 1 to 4 , the specific implementation methods of the present invention are as follows:

[0037] Example 1

[0038] This embodiment provides a method for modifying base oil molecules of a gasoline engine oil composition, comprising the following steps:

[0039] Dehydration treatment: 1000g of API Group III base oil (viscosity index 130, kinematic viscosity 6.5mm² / s at 100°C) was added to a four-necked flask equipped with a stirrer, thermometer, and condenser. The temperature was raised to 110°C and dehydrated at a vacuum of -0.09MPa for 1.5 hours. The moisture content after dehydration was detected to be 20ppm.

[0040] To carry out the silane grafting reaction, cool the mixture to 70°C and introduce nitrogen to displace the air for 30 minutes. Then, add 45g of 3-mercaptopropyltrimethoxysilane. The mixture had previously been vacuum-dehydrated at 45°C and -0.09 MPa for 1 hour. Continue purging with nitrogen for 10 minutes after addition, and the system moisture level should be 35ppm. Then, slowly raise the temperature to 165°C. Add 3.2g of dibutyltin dilaurate catalyst (previously diluted with 15g of base oil). Turn on an ultrasonic generator (frequency 30kHz, power density 1.0W / cm²) for 5 minutes every 15 minutes, and maintain the reaction temperature for 5 hours.

[0041] The epoxy grafting reaction was carried out by cooling the mixture to 130°C, adding 35 g of glycidyl methacrylate, and then adding 0.5 g of boron trifluoride etherate as a catalyst. Dry oxygen (moisture content 8 ppm) was introduced at a flow rate of 0.2 L / min, and the reaction was carried out for 2.5 hours.

[0042] Carry out pyrrolidone-based grafting reaction: cool to 90°C, add 0.2g of dibenzoyl peroxide dissolved in base oil, and stir for 5 minutes; add 20g of N-vinyl pyrrolidone in 3 batches, with an interval of 20 minutes between each batch. Immediately after each addition, apply 0.25MPa nitrogen pressure and maintain for 10 minutes. Continue the reaction for 1.5 hours.

[0043] Product post-treatment: the temperature was raised to 130°C, low-boiling substances were removed at a vacuum of -0.095 MPa for 1 hour, and then the product was filtered through a 4 μm filter element (filtration pressure 0.2 MPa), and finally treated in a 1.0 T strong magnetic field for 45 minutes to obtain modified base oil A.

[0044] This embodiment provides a method for preparing a gasoline engine oil composition, comprising the following steps:

[0045] Weigh the following components by weight:

[0046] Modified base oil A: 80 parts; borate ashless dispersant (polyisobutylene succinimide borate, number average molecular weight 2000, boron content 1.6wt%): 7 parts; zinc dialkyl dithiophosphate (ZDDP): 4.5 parts; aromatic amine antioxidant (octylated diphenylamine: N-phenyl-α-naphthylamine = 2:1, containing 1.0wt% nano-cerium dioxide): 3.5 parts; methacrylate viscosity index improver: 6 parts; benzotriazole derivative metal passivator: 1 part; graphene quantum dot additive (particle size 5nm, hydroxyl and carboxyl functional group content 15%): 1.2 parts; ionic liquid additive (1-butyl-3-methylimidazolium hexafluorophosphate, purity 99.2%, moisture 0.04%): 1.8 parts;

[0047] The above components were stirred and mixed at 60° C. for 2 hours, and then degassed at a vacuum degree of −0.09 MPa for 30 minutes to obtain a gasoline engine oil composition S1.

[0048] Example 2

[0049] This embodiment provides a method for modifying base oil molecules of a gasoline engine oil composition, comprising the following steps:

[0050] Dehydration treatment: 1000g of API Group III base oil (viscosity index 125, kinematic viscosity 5.8mm² / s at 100°C) was added to the reactor, heated to 105°C, and dehydrated at a vacuum of -0.085MPa for 2 hours. The moisture content after dehydration was 18ppm.

[0051] To carry out the silane grafting reaction, cool the reaction mixture to 65°C and replace the air with nitrogen three times, maintaining a positive nitrogen pressure of 0.02-0.03 MPa after each replacement. Add 38g of 3-mercaptopropyltrimethoxysilane, which had previously been dehydrated at 40-50°C and -0.09 MPa under vacuum for one hour to control the moisture content to ≤ 0.02%. Continue purging with nitrogen for 30 minutes, and the system water content should be 40 ppm. Raise the temperature to 155°C. Add 2.8g of dibutyltin dilaurate catalyst, and operate ultrasonic waves (25 kHz frequency, 0.8 W / cm² power density) for 5 minutes every 15 minutes, allowing the reaction to proceed for 6 hours.

[0052] Carry out epoxy grafting reaction: cool to 125°C, add 28g of glycidyl methacrylate, then add 0.1-0.3% of the total system weight of boron trifluoride etherate complex as an epoxy ring-opening catalyst, and introduce dry oxygen (flow rate 0.15L / min, moisture 5ppm) for 3 hours.

[0053] Carry out pyrrolidone-based grafting reaction: cool to 85°C, add 0.15g dibenzoyl peroxide as an initiator, stir and dissolve; add 15g N-vinyl pyrrolidone in 3 batches, with an interval of 25 minutes between each batch, pressurize with 0.2MPa nitrogen pressure for 10 minutes each time, and react for 2 hours.

[0054] Product post-treatment: remove low-boiling substances at 125°C and -0.09 MPa for 1.5 hours, filter through a 3 μm filter element (pressure 0.25 MPa), and treat in a 0.8 T strong magnetic field for 50 minutes to obtain modified base oil B.

[0055] This embodiment provides a method for preparing a gasoline engine oil composition, comprising the following steps:

[0056] Weigh the following components by weight:

[0057] Modified base oil B: 75 parts; borate ashless dispersant (number average molecular weight 1800, boron content 1.4wt%): 8 parts; ZDDP: 5 parts; aromatic amine antioxidant (containing 0.8wt% nano-cerium dioxide): 4 parts; viscosity index improver: 7 parts; metal passivator: 0.8 parts; graphene quantum dot additive (particle size 3nm, functional group content 12%): 0.8 parts; ionic liquid additive: 2.4 parts;

[0058] The mixture was stirred and mixed at 55° C. for 2.5 hours and degassed for 40 minutes to obtain gasoline engine oil composition S2.

[0059] Example 3

[0060] This embodiment provides a method for modifying base oil molecules of a gasoline engine oil composition, comprising the following steps:

[0061] Dehydration treatment: 1000g of API Group III base oil (viscosity index 135, kinematic viscosity 7.2mm² / s at 100°C) was heated to 115°C and dehydrated at -0.095MPa vacuum for 1 hour to reduce the moisture content to 25ppm.

[0062] To carry out the silane grafting reaction: cool the system to 75°C and replace the air with nitrogen three times. Add 52g of 3-mercaptopropyltrimethoxysilane. Dehydrate the system at 40-50°C and -0.09 MPa vacuum for one hour to control the moisture content to ≤0.02%. Continue purging with nitrogen for 30 minutes, and check the system water content to ≤50ppm. Then, raise the temperature to 175°C. Add 4.0g of dibutyltin dilaurate catalyst. Ultrasonic wave (frequency 35kHz, power density 1.2W / cm²) is used for 5 minutes every 15 minutes, and the reaction is allowed to proceed for 4 hours.

[0063] Carry out epoxy grafting reaction: cool to 135°C, add 42g of glycidyl methacrylate, then add 0.1-0.3% of the total system weight of boron trifluoride etherate as an epoxy ring-opening catalyst, and introduce dry oxygen (flow rate 0.25L / min, moisture 10ppm) for 2 hours.

[0064] Carry out the pyrrolidone-based grafting reaction: cool to 95°C, add 0.25g of dibenzoyl peroxide as an initiator, and stir to dissolve; add 25g of N-vinyl pyrrolidone in three batches, with an interval of 15 minutes between each batch. Pressurize with 0.3MPa nitrogen pressure each time to suppress monomer volatilization, hold for 8 minutes, and react for 1 hour.

[0065] Product post-treatment: remove low-boiling substances at 135°C and -0.1 MPa for 0.5 hour, filter through a 5 μm filter element (pressure 0.15 MPa), and treat in a 1.2 T strong magnetic field for 35 minutes to obtain modified base oil C.

[0066] This embodiment provides a method for preparing a gasoline engine oil composition, comprising the following steps:

[0067] Weigh the following components by weight:

[0068] Modified base oil C: 82 parts; borate ashless dispersant (number average molecular weight 2500, boron content 1.8wt%): 6 parts; ZDDP: 3.8 parts; aromatic amine antioxidant (containing 1.2wt% nano-cerium dioxide): 3 parts; viscosity index improver: 5 parts; metal passivator: 1.2 parts; graphene quantum dot additive (particle size 7nm, functional group content 18%): 1.5 parts; ionic liquid additive: 1.5 parts;

[0069] The mixture was stirred and mixed at 65° C. for 1.5 hours and degassed for 25 minutes to obtain gasoline engine oil composition S3.

[0070] Comparative Example

[0071] Base oil treatment method

[0072] 1000g of the same API Group III base oil (viscosity index 130, kinematic viscosity 6.5 mm² / s at 100°C) was dehydrated at 110°C and -0.09 MPa for 1.5 hours without grafting modification and was designated as base oil D.

[0073] Preparation of gasoline engine oil composition

[0074] Weigh by weight:

[0075] Base oil D: 80 parts; conventional polyisobutylene succinimide dispersant: 7 parts; ZDDP: 4.5 parts; diphenylamine antioxidant: 3.5 parts; viscosity index improver: 6 parts; metal passivator: 1 part

[0076] The mixture was stirred and mixed at 60° C. for 2 hours and degassed for 30 minutes to obtain gasoline engine oil composition D1.

[0077] The performance results of the embodiments and comparative examples are shown in the following table:

[0078] Table 1

[0079] Test items Example 1 Example 2 Example 3 Comparative Example Kinematic viscosity (100℃, mm² / s) 11.8 10.9 12.3 11.5 Viscosity Index 185 180 190 165 High temperature and high shear viscosity (150℃, mPa・s) 3.5 3.3 3.6 3.0 Pour point (℃) -39 -37 -38 -35 Foaming (ml / ml) 10 / 0 15 / 0 5 / 0 45 / 10 Oxidation stability (TOST life, h) >5000 4800 >5000 2200 Wear spot diameter (mm) 0.42 0.45 0.40 0.65 Sediment weight (mg) 8 10 7 25 Acid value increase (mg KOH / g) 0.8 1.0 0.7 3.2

[0080] The test results show that the gasoline engine oil compositions of Examples 1-3 are significantly superior to the comparative examples in terms of viscosity index, high temperature stability, anti-wear performance and oxidation stability, demonstrating the synergistic effect of the molecularly modified base oil and additive formulation of the present invention.

[0081] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A gasoline engine oil composition, characterized in that: The invention is composed of the following components in parts by weight: 70-85 parts of molecularly modified base oil, 5-10 parts of borate ashless dispersant, 3-6 parts of zinc dialkyl dithiophosphate, 2-5 parts of aromatic amine antioxidant, 4-8 parts of methacrylate viscosity index improver, and 0.5-1.5 parts of benzotriazole derivative metal deactivator; The molecularly modified base oil is prepared by the following method: mixing the base oil with 3-mercaptopropyltrimethoxysilane, heating to 150-180° C. under nitrogen protection, adding dibutyltin dilaurate as a catalyst for reaction, then adding glycidyl methacrylate and continuing the reaction, and finally adding N-vinylpyrrolidone and reacting at 80-100° C. to obtain a modified base oil having siloxane groups, epoxy groups, and pyrrolidone groups grafted onto the molecular chain. The chemical equation of the reaction is as follows: ； ； 。 2. The gasoline engine oil composition according to claim 1, characterized in that The invention also includes 0.5-2 parts of graphene quantum dot additives. The graphene quantum dots have a particle size of 2-8 nm, contain hydroxyl and carboxyl functional groups on the surface, and are uniformly dispersed in the base oil by ultrasonic dispersion.

3. The gasoline engine oil composition according to claim 1, characterized in that The invention also includes 1-3 parts of an ionic liquid additive, wherein the ionic liquid is 1-butyl-3-methylimidazolium hexafluorophosphate, the purity of which is ≥99% and the moisture content is ≤0.05%.

4. The gasoline engine oil composition according to claim 1, characterized in that The borate ashless dispersant is polyisobutylene succinimide borate, which has a number average molecular weight of 1000-3000 and a boron content of 1.2-2.0 wt%.

5. The gasoline engine oil composition according to claim 1, characterized in that The aromatic amine antioxidant is a compound of octylated diphenylamine and N-phenyl-α-naphthylamine, with a mass ratio of 2:1, and contains 0.5-1.5wt% of a nano-cerium dioxide synergist.

6. A method for modifying base oil molecules of the gasoline engine oil composition according to claim 1, characterized in that: The following steps are involved: S1: Heat the base oil to 100-120°C and dehydrate it under a vacuum of -0.08 to -0.1 MPa for 1-2 hours; S2: Cooling to 60-80°C, introducing nitrogen to replace the air, then adding 3-mercaptopropyltrimethoxysilane, and raising the temperature to 150-180°C; the 3-mercaptopropyltrimethoxysilane must be vacuum dehydrated in advance, and the total water content of the system must be controlled to ≤50ppm after addition; S3: Add dibutyltin dilaurate catalyst, maintain the temperature for 4-6 hours, and apply 20-40kHz ultrasound during the reaction; S4: Cooling to 120-140°C, adding glycidyl methacrylate, and then adding 0.1-0.3% of the total mass of the system of boron trifluoride etherate complex as an epoxy ring-opening catalyst, while introducing oxygen at an oxygen flow rate of 0.1-0.3 L / min·kg base oil, and continuing the reaction for 2-3 hours; S5: Cooling again to 80-100°C, adding 0.5-1.0 parts of dibenzoyl peroxide as an initiator, stirring and dissolving; adding N-vinyl pyrrolidone in three batches, with an interval of 20 minutes between each batch, applying 0.2-0.3 MPa nitrogen pressure after each batch to suppress monomer volatilization, and maintaining it for 10 minutes; the initiator initiates polymerization and grafting of the double bonds of N-vinyl pyrrolidone with the residual active sites on the base oil molecular chain, and the reaction is carried out for 1-2 hours; S6: After the reaction is completed, remove low-boiling substances at 120-140° C. and a vacuum degree of -0.09 to -0.1 MPa, filter through a 3-5 μm filter element, and filter at a filtration pressure of ≤0.3 MPa to obtain a modified base oil.

7. The base oil molecule modification method according to claim 6, characterized in that: The power density of the ultrasound in S3 is 0.5-1.5 W / cm² and is turned on for 5 minutes every 15 minutes.

8. The base oil molecule modification method according to claim 6, characterized in that: The oxygen in S4 is dried by molecular sieve before being introduced, and the moisture content is ≤10ppm.

9. The base oil molecule modification method according to claim 6, characterized in that: After each batch of N-vinyl pyrrolidone was added in S5, a nitrogen pressure of 1-2 MPa was immediately applied and maintained for 10 minutes.

10. The base oil molecule modification method according to claim 6, characterized in that: After the filtration in S6, the modified base oil is further subjected to a step of being treated in a strong magnetic field, wherein the magnetic field strength is 0.5-1.5 T and the treatment time is 30-60 minutes.

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