A composite additive for internal combustion engine oil, its preparation method and application

Abstract

This invention belongs to the field of lubricating oil technology, specifically relating to a composite additive for internal combustion engine oil, its preparation method, and its application. The composite additive, by mass percentage, comprises the following raw materials: 5-25% sulfonate, 5-12.5% ​​antioxidant and corrosion inhibitor, 5-12.5% ​​anti-wear agent, 5-10% antioxidant, 1-2.5% heptadecanyl imidazoline succinate, 0.5-1% nanocomposite, and dispersant to make up the balance to 100%; the nanocomposite is a composite of nano-molybdenum carbide and nano-alumina. Lubricating oil using the composite additive of this invention exhibits good wear resistance, water resistance, and corrosion resistance, while also showing good low-temperature fluidity and low loss. It effectively inhibits oil oxidation and deterioration, as well as the formation of deposits, reducing the frequency of low-speed pre-ignition in the engine and providing protection against timing chain and valve system wear.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil technology, specifically relating to a composite additive for internal combustion engine oil, its preparation method, and its application. Background Technology

[0002] Currently, the green and low-carbon transformation of automobiles and vehicle energy is a global consensus in the automotive industry. Methanol, also known as hydroxymethane, is a liquid at room temperature and pressure. It is a low-cost, easy-to-transport, easy-to-store, and highly safe liquid fuel. Compared with gasoline, methanol has advantages in terms of economy, safety, environmental friendliness, reliability, and applicability.

[0003] Methanol fuel has been used as an alternative fuel for vehicles for a long time, and methanol vehicle technology is relatively mature. It is an ideal substitute for traditional energy engines while maintaining low nitrogen oxide emissions. Currently, the market penetration rate of methanol vehicles is gradually increasing, which will further increase the demand for methanol internal combustion engine lubricants.

[0004] Methanol fuel differs significantly from regular gasoline in its combustion characteristics and combustion products. Therefore, the requirements and impacts on lubricating oil in methanol internal combustion engines also differ. For example, the main combustion products of methanol are formic acid, formaldehyde, and water. Formic acid is a strong acid, so the lubricating oil needs to be corrosion-resistant. Methanol is highly hydrophilic and easily absorbs moisture at low temperatures, which can lead to emulsification of the lubricating oil and damage the oil film strength. Therefore, the lubricating oil needs to be water-resistant. Methanol easily dissolves additives, leading to lubrication failure. Therefore, the lubricating oil needs to be resistant to methanol dissolution.

[0005] Chinese Patent Publication No. CN 119931757 A discloses a methanol engine lubricating oil composition and its preparation method. The provided methanol engine lubricating oil composition, based on its mass, comprises the following components: 80%–98% lubricating oil base oil, 0.7%–1.2% calcium sulfonate, 0.3%–0.5% magnesium sulfonate, 0.5%–0.8% antioxidant, anti-wear, and anti-corrosion additives, and 6.0%–8.0% antioxidants. The antioxidant, anti-wear, and anti-corrosion additives include zinc dialkyl dithiophosphate; the antioxidants include at least two of ester compounds, phenolic compounds, or amine compounds. However, this technical solution does not address oxidation and wear resistance.

[0006] Chinese Patent Publication No. CN118185689A discloses a lubricating oil additive and its application. The lubricating oil additive of this invention includes an ashless dispersant, a metal detergent, a rust inhibitor, an antioxidant and corrosion inhibitor, an antioxidant, a metal deactivator, a friction reducer, an anti-wear agent, and a base oil. The antioxidant and corrosion inhibitor includes zinc dialkyl dithiophosphate as shown in Formula I. In Formula I, R1 to R4 may be the same or different, and each is independently selected from C3-C12 secondary or primary alkyl groups. However, the viscosity change at 40 degrees Celsius of this technical solution is 124.4-363.45%, and its antioxidant properties need improvement.

[0007] Furthermore, starting May 1, 2020, the latest ILSAC passenger car engine oil standards GF-6A and GF-6B, as well as the highest quality API SP, began their first certification processes. Domestic and international lubricant manufacturers have also successively launched SP quality-level gasoline engine oils that meet the China VI emission standards. GF-6A will replace GF-5 and lower standards upon its implementation. GF-6B is incompatible with traditional engine oil standards and is only recommended for new vehicles using 0W-16. Small-displacement turbocharging, direct injection technology, GPF, hybrid power, and energy conservation and environmental protection will be future development trends for passenger car engines. China VI engines have higher requirements for gasoline engine oils, with specific requirements for preventing low-speed pre-ignition (LSPI) caused by TGDI direct injection technology, and for suppressing sludge and carbon deposits around the combustion chamber and fuel injectors.

[0008] In order to combine methanol engine oil with high-end gasoline engine oil and achieve "one oil for multiple uses", the applicant hereby proposes this invention. Summary of the Invention

[0009] The present invention aims to solve one or more technical problems existing in the prior art, and at least provide a beneficial solution. Specifically, the present invention provides a composite additive for internal combustion engine oil, its preparation method and application, which has good wear resistance, water resistance and corrosion resistance, good low-temperature fluidity, low loss, can effectively inhibit oil oxidation and deterioration and the formation of deposits, can reduce the frequency of low-speed pre-ignition in the engine, and provides timing chain wear protection and valve system wear protection for the engine.

[0010] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0011] In a first aspect, the present invention provides a compound additive for internal combustion engine oil, comprising, by mass percentage, the following raw materials: 5-25% sulfonate, 5-12.5% ​​antioxidant and corrosion inhibitor, 5-12.5% ​​anti-wear agent, 5-10% antioxidant, 1-2.5% heptadecanyl imidazoline succinate, 0.5-1% nanocomposite, and dispersant to make up the balance to 100%; wherein the nanocomposite is a composite of nano molybdenum carbide and nano alumina.

[0012] In some preferred embodiments, the sulfonate is selected from superbase synthetic sulfonic acid and / or superbase synthetic alkylbenzene sulfonate magnesium.

[0013] Preferably, the calcium content of the super-alkalinity synthetic calcium sulfonate is ≥14mg, and the total alkalinity is ≥395mgKOH / g.

[0014] Preferably, the magnesium content of the super-alkaline synthetic alkylbenzene sulfonate is ≥8.5 mg, and the total alkalinity is ≥395 mg KOH / g.

[0015] More preferably, the magnesium content of the super-alkaline synthetic alkylbenzene sulfonate magnesium is 8.5-10 mg, and the total alkalinity is 395-410 mg KOH / g.

[0016] In some preferred embodiments, the antioxidant and anticorrosive agent is selected from zinc thiophosphate secondary alcohol salt and / or zinc dipentyl dithiocarbamate.

[0017] Preferably, the zinc salt has a zinc content ≥9.5 mg, a phosphorus content ≥8.5 mg, and a sulfur content ≥16 mg.

[0018] More preferably, the zinc content of the zinc thiophosphate secondary alcohol is 9.5-10.8 mg, the phosphorus content is 8.5-9.5 mg, and the sulfur content is 16-18.5 mg.

[0019] In some preferred embodiments, the anti-wear agent is selected from aminothioesters and / or triphenyl thiophosphates.

[0020] In some preferred embodiments, the antioxidant is alkylated diphenylamine.

[0021] In some preferred embodiments, the preparation method of the nanocomposite includes the following steps: ammonium heptamolybdate, aluminum nitrate nonahydrate and glucose are placed in water and stirred evenly, heated to boiling to completely evaporate the water, to obtain composite powder; the composite powder is carbonized to obtain nanocomposite.

[0022] Preferably, the mass ratio of ammonium heptamolybdate, aluminum nitrate nonahydrate, glucose, and water is 14-16:14-16:6-8:80-120.

[0023] Preferably, the carbonization conditions are: nitrogen as the protective gas, 900-1200℃ at a time, and 1-3 hours.

[0024] In some preferred embodiments, the dispersant is a mixture of phosphobically borated polyisobutylene bis(succinimide) and high molecular weight polyisobutylene succinimide.

[0025] Preferably, the mass ratio of the phosphobically borated polyisobutylene bis(succinimide) to the high molecular weight polyisobutylene succinimide is 1.2-1.7:1.

[0026] Preferably, the phosphorus-boronized polyisobutylene bis(succinimide) has a nitrogen content ≥1m, a phosphorus content ≥0.6m, and a boron content ≥0.8m.

[0027] More preferably, the phosphorus-boronized polyisobutylene bis(succinimide) has a nitrogen content of 1.55-1.9 mg, a phosphorus content of 0.6-0.9 mg, and a boron content of 0.85-1.15 mg.

[0028] Preferably, the high molecular weight polyisobutylene succinimide has a nitrogen content ≥0.8 mg and a total base value ≥20 mg KOH / g.

[0029] More preferably, the high molecular weight polyisobutylene succinimide has a nitrogen content of 0.85-1.05 mg and a total alkali value of 20-30 mg KOH / g.

[0030] Secondly, the present invention provides a method for preparing the above-mentioned internal combustion engine oil composite additive, comprising the following steps: stirring a dispersant, a sulfonate, an antioxidant and corrosion inhibitor, an anti-wear agent, an antioxidant, a heptadecanyl imidazoline succinate, and a nanocomposite until homogeneous.

[0031] Thirdly, the present invention provides the application of the above-mentioned internal combustion engine oil composite additive in methanol internal combustion engine lubricating oil or gasoline internal combustion engine lubricating oil.

[0032] Fourthly, the present invention provides an internal combustion engine lubricating oil comprising the above-mentioned internal combustion engine oil composite additive.

[0033] Preferably, the internal combustion engine lubricating oil, by mass percentage, comprises 30-40% polyalphaolefin, 5-10% trimethylolpropane ester, 5-10% of the above-mentioned internal combustion engine oil compound additives, and base oil to make up to 100%.

[0034] Preferably, the base oil is a Group II hydrotreated base oil.

[0035] More preferably, the Group II hydrotreated base oil is a mixture of Group II hydrotreated base oil 500N and Group II hydrotreated base oil 150N.

[0036] More preferably, the mass ratio of Group II hydrotreated base oil 500N to Group II hydrotreated base oil 150N is 1.1-1.3:1.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. In response to the technical problem that existing technologies improve the anti-wear and anti-corrosion properties of lubricating oil by adding zinc dialkyl dithiophosphate, but methanol combustion produces water, and zinc dialkyl dithiophosphate decomposes into phosphoric acid and other products under hydrolysis, losing its anti-wear effect. At the same time, hydrolysis also increases the acid value of the lubricating oil, accelerates the corrosion of metal parts, and seriously affects the service life of the engine, this invention uses a self-made nanocomposite, namely a composite of nano molybdenum carbide and nano alumina, which significantly improves the wear resistance, water resistance and corrosion resistance of lubricating oil.

[0039] 2. Addressing the technical problem that methanol combustion produces acid and water, easily leading to lubricating oil stratification and strong corrosion, this invention utilizes a self-made nanocomposite with the synergistic addition of heptadecanylimidazoline succinate. This enables the lubricating oil to remain stable for extended periods at both room and high temperatures, exhibiting excellent corrosion resistance. During this process, the inventors discovered that heptadecanylimidazoline succinate exhibits better corrosion resistance than toluene-triazole derivatives. This may be due to two main reasons: firstly, heptadecanylimidazoline succinate can neutralize acidic substances; the bifunctional groups of the imidazoline ring and succinate adsorb onto the metal surface to form a dense passivation film while also possessing dehydration and demulsification functions, preventing the lubricating oil from separating due to moisture; secondly, the high-temperature stability of heptadecanylimidazoline succinate itself and its polar interaction with the nanocomposite form a denser protective film.

[0040] 3. This invention, through the combined action of sulfonates, antioxidants and corrosion inhibitors, anti-wear agents, antioxidants, heptadecanyl imidazoline succinate, nanocomposites and dispersants, achieves good low-temperature fluidity and low loss, effectively inhibiting oil oxidation and deterioration and the formation of deposits, reducing the frequency of low-speed pre-ignition in engines, providing timing chain wear protection and valve system wear protection for engines, and filling the gap in the domestic market for universal high-end gasoline engine oil and methanol engine oil. Attached Figure Description

[0041] Figure 1 Here is a SEM image of the nanocomposite from Example 1;

[0042] Figure 2 The graph shows the performance test results of the internal combustion engine oil composite additive in Example 3;

[0043] Figure 3 and Figure 4 The graph shows the test results of the lubricating oil prepared using the internal combustion engine oil composite additive of Example 3. Detailed Implementation

[0044] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0045] Unless otherwise specified, the raw materials, reagents or apparatus used in the following examples and comparative examples are available from conventional commercial sources or can be obtained by existing known methods.

[0046] Super-alkalinity synthetic alkylbenzene sulfonate: magnesium content 8.5-10 mg%, total alkalinity 395-410 mg KOH / g, Jinzhou Mingyue Technology Co., Ltd., model: MY-T107.

[0047] Zinc sulfate secondary alcohol salt: zinc content 9.5-10.8 mg, phosphorus content 8.5-9.5 mg, sulfur content 16-18.5 mg, Jinzhou Shengda Chemical Co., Ltd., model: T-205.

[0048] Aminothioesters: Shanghai Demao Chemical Co., Ltd., Model: T323.

[0049] Alkylated diphenylamine: Xiangyang Chemical Plant, Jiaxing City.

[0050] Heptadecanyl imidazoline succinate: Luoyang Pacific United Petrochemical Co., Ltd., Model: CMET T703.

[0051] Phosphorus-boron-modified polyisobutylene bis(succinimide): nitrogen content 1.55-1.9 mg, phosphorus content 0.6-0.9 mg, boron content 0.85-1.15 mg, Kangtai Lubricating Oil Additives Co., Ltd., Model: KT 1356PB

[0052] High molecular weight polyisobutylene succinimide: nitrogen content 0.85-1.05 mg, total base value 20-30 mg KOH / g, Kangtai Lubricating Oil Additives Co., Ltd., model: KT 1963.

[0053] Nano-molybdenum carbide: 80nm particle size, Zhongke Leiming (Beijing) Technology Co., Ltd., model: DK-Mo2C-001.

[0054] Nano-alumina: Particle size 200-300nm, Suzhou Baird New Material Technology Co., Ltd., Model: BRD001-N200.

[0055] Zinc dialkyl dithiophosphate: Wuhan Jiyesheng Chemical Co., Ltd.

[0056] Group II hydrotreated base oil 500N: Wuxi Kema Materials Co., Ltd.

[0057] Group II hydrotreated base oil 150N: Wuxi Yongzhen Industrial Oil Co., Ltd.

[0058] Polyalphaolefin: SpectraSyn 6: Dongguan Hongli Chemical Technology Co., Ltd.

[0059] BASF Irgamet 30, a toluene-triazole derivative: Shanghai Kaiyin Chemical Co., Ltd.

[0060] Example 1

[0061] Preparation of nanocomposite: 15g ammonium heptamolybdate, 15g aluminum nitrate nonahydrate, and 7g glucose were placed in 100g water and stirred until homogeneous. The mixture was heated to boiling to completely evaporate the water, yielding a composite powder. The composite powder was then carbonized under nitrogen at 1000℃ for 2 hours to obtain the nanocomposite. The SEM image of the nanocomposite is shown below. Figure 1 As shown.

[0062] Examples 2-4

[0063] The formulation of the internal combustion engine oil composite additive, by mass percentage, is shown in Table 1:

[0064] Table 1

[0065]

[0066] The preparation method of the above-mentioned internal combustion engine oil composite additive is as follows: the dispersant, sulfonate, antioxidant and corrosion inhibitor, anti-wear agent, antioxidant, heptadecanyl imidazoline succinate and nanocomposite are stirred evenly to obtain the additive.

[0067] The quality indicators of the internal combustion engine oil compound additive in Example 3 are as follows: Figure 2 As shown.

[0068] Comparative Example 1

[0069] The only difference from Example 3 is that the nanocomposite is replaced with molybdenum oxide nanoparticles; everything else is the same.

[0070] Comparative Example 2

[0071] The only difference from Example 3 is that the nanocomposite is replaced with nano-alumina; everything else is the same.

[0072] Comparative Example 3, by mass percentage, has the following formulation as shown in Table 2:

[0073] Table 2

[0074]

[0075] The preparation method of the above-mentioned internal combustion engine oil composite additive is as follows: the dispersant, sulfonate, antioxidant and corrosion inhibitor, anti-wear agent, antioxidant, heptadecanyl imidazoline succinate and dialkyl dithiophosphate zinc are stirred evenly to obtain the additive.

[0076] Comparative Example 4

[0077] The only difference from Example 3 is that the nanocomposite is replaced with an equal mass of heptadecenyl imidazoline succinate; all else is the same.

[0078] Comparative Example 5

[0079] The only difference from Example 3 is that heptadecanyl imidazoline succinate is replaced with an equal mass of nanocomposite; all else is the same.

[0080] Comparative Example 6

[0081] The only difference from Example 3 is that heptadecanyl imidazoline succinate is replaced with an equal mass of the toluenetriazole derivative BASF Irgamet 30; all other aspects are the same.

[0082] Application examples

[0083] Internal combustion engine lubricating oils were prepared using the internal combustion engine oil composite additives of Examples 1-3 and Comparative Examples 1-6, respectively. The formulations, by mass percentage, are as follows:

[0084] Group II hydrotreated base oil 500N 25%;

[0085] Group II hydrotreated base oil 150N 20%;

[0086] Polyalphaolefin 38.5%;

[0087] Trimethylolpropane 8.0%;

[0088] Examples 1-3 and Comparative Examples 1-6: 8.5% of internal combustion engine oil composite additives.

[0089] The preparation method is as follows: Mix Group II hydrotreated base oil 500N, Group II hydrotreated base oil 150N, polyalphaolefin, trimethylolpropane ester, and the internal combustion engine oil composite additives of Examples 1-3 and Comparative Examples 1-6 evenly to obtain the product.

[0090] Test Example 1: Wear resistance performance

[0091] Three steel balls with a diameter of 12.7 mm were clamped in an oil box and submerged in test oil. Another steel ball of the same diameter was placed on top of the three balls. Under the action of a force of 392 N, they formed a "three-point contact". After the test oil reached 75 °C, the top ball was rotated at 1200 r / min for 60 min. After the test, the wear resistance performance was evaluated by the average wear scar diameter dm of the three balls. The results are shown in Table 3.

[0092] Table 3

[0093]

[0094] As can be seen from Table 3, the wear resistance of nano molybdenum oxide, nano alumina, or zinc dialkyl dithiophosphate alone is not as good as that of the nanocomposite of the present invention.

[0095] Test Example 2: Water Resistance Performance

[0096] Add 20g of internal combustion engine lubricating oil, 2g of methanol, and 2g of water to a beaker, and stir at 10000r / min±2000r / min for 2min±2s. Observe whether stratification occurs after placing the mixture at 25℃ and 150℃ for 3 months respectively. If stratification occurs, it is considered unqualified. The results are shown in Table 4.

[0097] Table 4

[0098]

[0099] As can be seen from Table 4, when the nanocomposite was replaced with zinc dialkyl dithiophosphate, it delaminated after being placed at 25℃ and 150℃ for 3 months, indicating poor water resistance.

[0100] When the nanocomposite was replaced with an equal mass of heptadecenyl imidazoline succinate, it delaminated after being placed at 150°C for 3 months, indicating poor water resistance.

[0101] When heptadecanyl imidazoline succinate was replaced with an equal mass of nanocomposite, delamination occurred after being placed at 25°C and 150°C for 3 months, indicating poor water resistance.

[0102] Replacing heptadecanyl imidazoline succinate with an equal mass of the toluenetriazole derivative BASF Irgamet 30 resulted in stratification after being placed at 150°C for 3 months, indicating poor water resistance.

[0103] In summary, the use of nanocomposites combined with heptadecanyl imidazoline succinate gives the lubricating oil excellent water resistance, thus meeting the requirements of methanol vehicles.

[0104] Test Example 3: Corrosion resistance performance:

[0105] The steel plate was immersed in internal combustion engine lubricating oil with 3% formic acid (relative to the mass of the internal combustion engine lubricating oil) and placed at 120℃ for 3 days. The corrosion was observed. If corrosion occurred, it was considered unqualified. The results are shown in Table 5.

[0106] Table 5

[0107]

[0108] As can be seen from Table 5, lubricants with poor water resistance also have poor corrosion resistance. The present invention adds specific heptadecenyl imidazoline succinate and nanocomposite to make the lubricant have excellent corrosion resistance.

[0109] Test Example 4

[0110] Basic performance tests were conducted on the lubricating oil prepared using the internal combustion engine oil composite additive of Example 3. The test items and results are as follows: Figure 3 As shown.

[0111] Depend on Figure 3 It can be seen that the lubricating oil of the present invention has low low-temperature dynamic viscosity and low-temperature pumping viscosity, indicating good low-temperature fluidity and low evaporation loss, indicating low loss.

[0112] Test Example 5

[0113] The lubricating oil prepared using the internal combustion engine oil composite additive of Example 3 was subjected to an SP bench test. The test items and results are as follows: Figure 4 As shown.

[0114] Depend on Figure 4 It can be seen that the lubricating oil of the present invention can effectively inhibit the oxidation and deterioration of engine oil and the formation of deposits, reduce the number of low-speed pre-ignition occurrences in the engine, and provide timing chain wear protection and valve system wear protection for the engine.

[0115] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A compound additive for internal combustion engine oil, characterized in that, The product comprises, by weight percentage, the following raw materials: 5-25% sulfonate, 5-12.5% ​​antioxidant and anti-corrosion agent, 5-12.5% ​​anti-wear agent, 5-10% antioxidant, 1-2.5% heptadecenyl imidazoline succinate, 0.5-1% nanocomposite, and dispersant to make up the balance to 100%; the nanocomposite is a composite of nano molybdenum carbide and nano alumina.

2. The internal combustion engine oil composite additive according to claim 1, characterized in that, The dispersant is a mixture of phosphobically borated polyisobutylene bis(succinimide) and high molecular weight polyisobutylene succinimide; the phosphobically borated polyisobutylene bis(succinimide) has a nitrogen content ≥1 mg, a phosphorus content ≥0.6 mg, and a boron content ≥0.8 mg; the phosphobically borated polyisobutylene bis(succinimide) has a nitrogen content of 1.55-1.9 mg, a phosphorus content of 0.6-0.9 mg, and a boron content of 0.85-1.15 mg.

3. The internal combustion engine oil composite additive according to claim 2, characterized in that, The sulfonate is magnesium alkylbenzene sulfonate synthesized with superbase value.

4. The internal combustion engine oil composite additive according to claim 3, characterized in that, The magnesium content of the super-alkalinity synthesized alkylbenzene sulfonate is ≥8.5 mg, and the total alkalinity is ≥395 mg KOH / g.

5. The internal combustion engine oil composite additive according to claim 4, characterized in that, The preparation method of the nanocomposite includes the following steps: ammonium heptamolybdate, aluminum nitrate nonahydrate and glucose are placed in water and stirred evenly, heated to boiling and the water is completely evaporated to obtain composite powder; the composite powder is carbonized to obtain nanocomposite.

6. The method for preparing the internal combustion engine oil composite additive according to any one of claims 1-5, characterized in that, The process includes the following steps: mixing the dispersant, sulfonate, antioxidant and anti-corrosion agent, anti-wear agent, antioxidant, heptadecenyl imidazoline succinate and nanocomposite until homogeneous.

7. The application of the internal combustion engine oil composite additive according to any one of claims 1-5 in methanol internal combustion engine lubricating oil or gasoline internal combustion engine lubricating oil.

8. An internal combustion engine lubricating oil, characterized in that, Includes the internal combustion engine oil compound additive as described in any one of claims 1-5.

9. The internal combustion engine lubricating oil according to claim 8, characterized in that, By weight percentage, it includes 30-40% polyalphaolefin, 5-10% trimethylolpropane ester, 5-10% of the above-mentioned internal combustion engine oil compound additives, and base oil to make up to 100%.

Images