Energy-saving diesel engine oil with ultra-long oil change mileage and preparation method thereof

Abstract

The invention discloses energy-saving diesel engine oil with ultra-long oil change mileage and a preparation method thereof, and belongs to the technical field of engine oil. The preparation method of the diesel engine oil comprises the following steps: heating the base oil to 70-80 DEG C, then adding the viscosity index improver, the clearing agent, the dispersing agent, the extreme pressure anti-wear agent, the antioxidant preservative, the antirust agent, the pour point depressant and the anti-foaming agent, and stirring for 2.5-3.5 hours to obtain a semi-finished product of the diesel engine oil; and then cooling to 45 DEG C, filtering under the positive pressure of 0.2 MPa, and naturally cooling to normal temperature to obtain the finished product diesel engine oil. The prepared diesel engine oil has excellent wear resistance, oxidation resistance and cleaning performance, and the dynamic friction coefficient can be effectively reduced; and therefore, the operation efficiency of the internal combustion engine can be improved, power loss caused by friction and oxidation is reduced, and an ultra-long oil change period is achieved while energy consumption is saved.

Description

Technical Field

[0001] This invention belongs to the field of engine oil technology, specifically, it relates to an energy-saving diesel engine oil with an ultra-long oil change interval and its preparation method. Background Technology

[0002] With increasingly stringent energy conservation requirements, fuel economy for road vehicles has become a key focus for both vehicle manufacturers and lubricant suppliers, making engine oil fuel economy a crucial performance indicator. Friction and wear are common phenomena during the operation of mechanical equipment and are significant causes of energy consumption and equipment failure. Lubricating oil is an essential material for maintaining the normal operation of mechanical equipment, and reducing the friction coefficient of engine oil is one of the important ways to improve fuel economy.

[0003] Currently, mainstream diesel engine oils, in their pursuit of longer oil change intervals, often face challenges related to insufficient high-temperature oxidation stability and anti-wear performance. Traditional additives are prone to degradation or ineffectiveness under harsh operating conditions, leading to a decline in oil performance and failing to balance long-term effectiveness and fuel efficiency. Furthermore, conventional mineral base oils have limitations in low-temperature fluidity and high-temperature viscosity retention, affecting engine lubrication efficiency and cold-start performance across a wide temperature range.

[0004] Ionic liquids, due to their unique physicochemical properties such as high thermal and chemical stability, near-non-volatile nature, good solubility, and strong adsorption capacity, show broad application prospects in the lubrication field. In the lubricating oil industry, the application of ionic liquids mainly falls into two categories: direct use as base lubricants and use as functional additives to enhance the performance of existing lubricants. However, conventional ionic liquids often exhibit poor solubility (oil solubility) in hydrocarbon base oils, which limits their practical application as lubricating oil additives. Therefore, developing ionic liquid additives with excellent oil solubility and the ability to produce synergistic effects with other components of lubricating oils is of great significance for the development of next-generation high-performance, long-life diesel engine oils. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an energy-saving diesel engine oil with an ultra-long oil change interval and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for preparing an energy-saving diesel engine oil with an ultra-long oil change interval includes the following steps: heating the base oil to 70-80℃, then adding a viscosity index improver, detergent, dispersant, extreme pressure anti-wear agent, antioxidant corrosion inhibitor, rust inhibitor, pour point depressant, and antifoaming agent, stirring for 2.5-3.5 hours to obtain a semi-finished diesel engine oil; subsequently cooling to 45℃, filtering under 0.2MPa positive pressure, and naturally cooling to room temperature to obtain the finished diesel engine oil.

[0007] In a more optimized manner, the raw materials for preparing the finished diesel engine oil include the following components: by weight, 60-80 parts base oil, 2-10 parts viscosity index improver, 1-5 parts detergent, 1-5 parts dispersant, 0.2-5 parts extreme pressure anti-wear agent, 0.5-5 parts antioxidant corrosion inhibitor, 1-5 parts rust inhibitor, 0.2-1 part pour point depressant, and 0.05-1 part antifoaming agent.

[0008] More preferably, the extreme pressure anti-wear agent comprises an oil-soluble ionic liquid anti-wear agent, optionally comprising one or more of isobutylene sulfide, molybdenum dialkyl dithiocarbamate, and triphenyl thiophosphate.

[0009] Ideally, the oil-soluble ionic liquid anti-wear agent is one or more of phosphorus-containing anti-wear agents and organic molybdenum-containing anti-wear agents.

[0010] For oil-soluble ionic liquid phosphorus-containing anti-wear agents, the cationic moiety contains long alkyl chains (butyl and propyl). These two hydrophobic alkyl chains are key to giving the entire molecule good oil solubility, ensuring good compatibility with base oil molecules and uniform dispersion of the anti-wear agent in lubricating oil. Simultaneously, the imidazole ring in the cationic moiety forms a rigid structure with a positive charge, planar structure, and high electron cloud density. This planar structure allows it to easily and tightly adsorb onto metal surfaces through physical adsorption and electrostatic interactions. The anionic moiety uses phosphorus (P) as the core anti-wear / extreme pressure functional element. Under the high temperature and pressure conditions generated by friction, phosphorus can undergo a tribochemical reaction with the metal surface to generate a mixed chemical film of iron phosphate, iron phosphite, etc. This film is relatively soft and has low shear strength, effectively preventing direct contact between the metal surface and transforming severe wear into slippage within the protective film, thereby achieving a friction-reducing effect.

[0011] It should be noted that the effect of this phosphorus-containing ionic liquid anti-wear agent is not a simple superposition of the functions of cationic and anionic compounds, but rather exhibits an excellent synergistic effect. Specifically, this synergistic effect is reflected in the following aspects: (1) Strong adsorption and stable spreading: The positively charged imidazolium cation is strongly adsorbed on the surface of the normally negatively charged metal friction pair through electrostatic attraction. The adsorption is strong and provides a stable "anchoring" effect for subsequent reactions. At the same time, the alkyl chain on the cation extends outward, which helps the entire ionic liquid molecule to dissolve in the oil and form an initial physical adsorption layer on the metal surface. (2) High-efficiency reaction film formation: When friction occurs, the local high temperature will cause the phosphate ester anions "anchored" on the metal surface to decompose rapidly, release active phosphorus species and react with the metal substrate to form the above-mentioned phosphorus-iron chemical reaction film. Since the cations have "transported" and "fixed" the reactants in the area that needs the most protection, the film formation reaction efficiency is extremely high and occurs at the beginning of the friction. (3) "Cushion layer" effect: Ionic liquids will arrange themselves in an orderly manner under friction, and even form a liquid film with a certain load-bearing capacity. This film can play a buffering and lubricating role, and together with the chemical reaction film, it forms a dual protective structure of "physical adsorption layer + chemical reaction layer".

[0012] Another type of oil-soluble ionic liquid organic molybdenum-based anti-wear agent, as a type of molybdenum-based anti-wear agent, exhibits a particularly prominent mechanism of action when present in ionic liquid form, specifically as follows: 1) Adsorption and preliminary lubrication: The imidazolium cation first firmly adsorbs the entire molecule onto the metal surface, and under mild friction conditions, the adsorption film can already play a lubricating role. 2) Tribocatalytic formation of molybdenum disulfide-like film: This is the key step. Under the combined action of high temperature, high pressure and mechanical shear force generated by friction (this condition can be regarded as a "reactor"), the molybdenum-oxygen species in the ionic liquid will react with the sulfur commonly contained in lubricating oil (from sulfur-containing additives or the base oil itself), and catalyze the formation of molybdenum disulfide or similar low-friction molybdenum sulfur oxides with a layered structure in situ. 3) Superlubrication mechanism: Molybdenum disulfide (MoS2) has a typical layered hexagonal crystal structure, with weak van der Waals forces connecting the layers. The shear strength is extremely low. The generated MoS2 film adheres to the surface of the friction pair, similar to a deck of cards. When friction occurs, slippage is mainly concentrated between the layers, resulting in an extremely low coefficient of friction. This characteristic is often referred to as "superlubrication" or "self-lubrication", and its effect is far superior to that of iron phosphate film generated by phosphorus. 4) Synergistic reinforcement: Imidazole cations not only serve as molecular carriers, but their decomposition may also provide elements such as carbon and nitrogen to participate in the formation of more robust and durable friction polymer surface films such as molybdenum carbonitride, further enhancing wear resistance and extreme pressure performance.

[0013] In a more optimized manner, the preparation process of the phosphorus-containing anti-wear agent is as follows: A1: N-propylimidazolium and 1-bromobutane were reacted at 75±2℃ for 45-50 h, and the mixture was washed and dried to obtain intermediate A; wherein the molar ratio of N-propylimidazolium to 1-bromobutane was 1:1.05. A2: Intermediate A is reacted with phosphate ester under alkaline conditions, and the mixture is washed and dried to obtain a phosphorus-containing anti-wear agent; wherein the molar ratio of intermediate A to phosphate ester is 1:1.1.

[0014] The synthetic route for step A1 is shown below: The synthetic route for step A2 is shown below: Where R1 is R2 is H.

[0015] In a more optimized manner, the preparation process of the organic molybdenum-based anti-wear agent is as follows: B1: N-propylimidazolium and 1-bromobutane were reacted at 75±2℃ for 45-50 h, and the mixture was washed and dried to obtain intermediate B; wherein the molar ratio of N-propylimidazolium to 1-bromobutane was 1:1.05. B2: Intermediate B is reacted with sodium molybdate dihydrate under acidic conditions, and the mixture is washed and dried to obtain an organic molybdenum-type anti-wear agent; wherein the molar ratio of intermediate B to sodium molybdate dihydrate is 1:1.05-1.1.

[0016] The synthetic route for step B1 is as follows: The synthetic route for step B2 is as follows: More preferably, the base oil is selected from at least two of cPAO (conventional polyalphaolefin), mPAO (metallocene polyalphaolefin), ETL synthetic oil, and synthetic ester; wherein the synthetic ester is one or more of adipate, diisooctyl sebacate, and pentaerythritol ester.

[0017] More preferably, the viscosity index improver is one or two of polymethyl methacrylate (PMA), ethylene / propylene copolymer (OCP), and hydrogenated styrene / diene copolymer (HSD).

[0018] More preferably, the detergent and dispersant are selected from at least two of high-base-value alkylphenol calcium sulfide, medium-base-value calcium sulfonate, high molecular weight polyisobutylene bis(succinimide), boronized polyisobutylene bis(succinimide), and polyisobutylene bis(succinimide). The antioxidant preservative is selected from at least two of 4,4'-methylenebis(2,6-di-tert-butyl)phenol, octyl diphenylamine, octyl-N-phenyl-α-naphthylamine and zinc dialkyl dithiophosphate; The rust inhibitor is one or more of sodium petroleum sulfonate, linear dodecenyl succinic acid, alkenyl succinate, and neutral dinonylnaphthalene sulfonate calcium; The pour point depressant is a polymethyl methacrylate; The antifoaming agent is one or more of oil-soluble polyethers and polyether-modified silicones.

[0019] Further optimized, the pour point depressant is one of VISCOPLEX 1-180 and VISCOPLEX 1-248 from Evonik GmbH, Germany.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: Firstly, the anti-wear agent used in this invention is an ionic liquid with excellent oil solubility. Its molecules contain polar groups and have high chemical activity. It can be firmly adsorbed onto the metal surface through the interaction forces between molecules or atoms and form an adsorption film by tightly arranging itself, thereby reducing wear, lowering the coefficient of friction, effectively improving the anti-wear performance of lubricating oil, and achieving energy-saving effect.

[0021] Secondly, the base oil and viscosity index improver used in this invention have excellent low-temperature performance, which greatly improves the low-temperature cold start efficiency of the oil, provides the oil film strength required under different operating conditions, and fully meets the real-time lubrication needs of vehicle engines.

[0022] Thirdly, the base oil used in this invention is a high-quality synthetic oil, with added ionic liquids that have good oil solubility. The ionic liquids have a wide temperature adaptability range, and combined with the effect of antioxidants, they can effectively improve the antioxidant performance of the oil and achieve an ultra-long oil change interval. Attached Figure Description

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] Figure 1 The friction coefficients of Examples 1-2 and Comparative Examples 1-3 of the present invention under different loads. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1: A method for preparing an energy-saving diesel engine oil with an ultra-long oil change interval, comprising the following steps: 40 parts cPAO4, 34 parts ETL6#, and 5 parts dioctyl sebacate were added to a reaction vessel, mechanically stirred, and heated to 75°C. Then, 5 parts ethylene / propylene copolymer, 3 parts hydrogenated styrene / diene copolymer, 3 parts high-base-value alkylphenol calcium sulfate, 3.5 parts high molecular weight polyisobutylene bis(succinimide), 1.5 parts zinc dialkyl dithiophosphate, 0.1 parts oil-soluble ionic liquid organic molybdenum type anti-wear agent, 0.3 parts oil-soluble ionic liquid phosphorus-containing anti-wear agent, 2 parts octyl-N-phenyl-α-methylnaphthylamine, 2 parts sodium petroleum sulfonate, 0.3 parts VISCOPLEX 1-248, and 0.02 parts polyether modified silicone defoamer were added. The mixture was stirred at 75°C for 3 hours to obtain semi-finished diesel engine oil. After the oil cooled to about 45°C, it was filtered under 0.2 MPa positive pressure and allowed to cool naturally to room temperature to obtain finished diesel engine oil.

[0027] Example 2: A method for preparing an energy-saving diesel engine oil with an ultra-long oil change interval, comprising the following steps: 40 parts of cPAO6, 30 parts of ETL4#, and 6 parts of pentaerythritol ester were added to a reaction vessel, mechanically stirred, and heated to 75°C. Then, 9 parts of ethylene / propylene copolymer, 3 parts of high-base-value sulfurized alkylphenol calcium, 4 parts of boronized polyisobutylene bis(succinimide), 0.1 parts of oil-soluble ionic liquid organic molybdenum type anti-wear agent, 0.3 parts of triphenyl thiophosphate, 1.5 parts of zinc dialkyl dithiophosphate, 2 parts of octyl diphenylamine, 1.5 parts of 4,4'-methylene bis(2,6-di-tert-butyl)phenol, 2 parts of neutral dinonylnaphthalene sulfonate calcium, 0.3 parts of VISCOPLEX 1-180, and 0.04 parts of oil-soluble polyether defoamer were stirred at 75°C for 3 hours to obtain semi-finished diesel engine oil. After the oil cooled to about 45°C, it was filtered under 0.2 MPa positive pressure and allowed to cool naturally to room temperature to obtain finished diesel engine oil.

[0028] Comparative Example 1: Mobil Delvac 5W-30 was used.

[0029] Comparative Example 2: Shell Rimula K Series CK-4 engine oil K15 5W-30 was used.

[0030] Comparative Example 3: A method for preparing an energy-saving diesel engine oil with an ultra-long oil change interval, comprising the following steps: 30 parts of cPAO6, 42 parts of ETL4#, and 5 parts of dioctyl sebacate were added to a reaction vessel, mechanically stirred, and heated to 75°C. Then, 8 parts of hydrogenated styrene / diene copolymer, 3 parts of high-base-value sulfurized alkylphenol calcium, 2.5 parts of boronized polyisobutylene bis(succinimide), 2.8 parts of polyisobutylene bis(succinimide), 0.2 parts of molybdenum dialkyldithiocarbamate, 0.35 parts of triphenyl thiophosphate, 1.5 parts of zinc dialkyldithiophosphate, 2 parts of octyl-N-phenyl-α-methylnaphthylamine, 2 parts of neutral dinonylnaphthalenesulfonate calcium, 0.3 parts of VISCOPLEX 1-248, and 0.02 parts of polyether-modified silicone defoamer were stirred at 75°C for 3 hours to obtain semi-finished diesel engine oil. After the oil cooled to about 45°C, it was filtered under 0.2 MPa positive pressure and allowed to cool naturally to room temperature to obtain finished diesel engine oil.

[0031] Testing and experimentation: The diesel engine oils of Examples 1-2 and Comparative Examples 1-3 were tested for kinematic viscosity at different temperatures according to GB / T 265; viscosity index was obtained according to GB / T 1995; pour point was tested according to GB / T 3535; low-temperature dynamic viscosity was tested according to GB / T 6538; wear scar diameter was tested according to NB / SH / T 0189; coefficient of friction was tested according to SH / T 0762; and oxidation stability (rotating oxygen bomb) of the lubricating oil was tested according to NB / SH / T 0193. The obtained structures are shown in Table 1 and Figure 1 As shown: Table 1 Test Project Example 1 Example 2 Comparative Example 3 Comparative Example 1 Comparative Example 2 <![CDATA[Kinematic viscosity at 100 °C (mm 2 / s)]]> 11.90 11.89 11.93 12.32 12.20 Viscosity Index 175 172 173 163 162 Pour point / ℃ -50 -50 -52 -40 -38 Low-temperature dynamic viscosity (-30℃) / mPa·s 1210 1300 1040 5230 5780 Wear scar diameter / mm 0.399 0.410 0.442 0.456 0.460 Rotating oxygen bomb (without water, 150℃) / min 2241 2217 1993 1977 1986 Conclusion: This invention successfully developed an energy-saving diesel engine oil with an ultra-long oil change interval and its preparation method. By using an oil-soluble ionic liquid as an extreme pressure anti-wear agent, combined with high-quality synthetic base oil and an optimized additive formulation, the prepared diesel engine oil exhibits significant advantages in anti-wear performance, oxidation resistance, and low-temperature fluidity. Experimental results show that this engine oil has a low coefficient of friction and wear scar diameter, excellent oxidation stability, and good low-temperature starting performance. It can significantly extend the oil change interval while achieving energy savings, meeting the demands of modern diesel engines for efficient lubrication and long service life.

[0032] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0033] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for preparing an energy-saving, ultra-long drain diesel engine oil, characterized by, The method comprises the following steps: The base oil is heated to 70-80℃, then the viscosity index improver, detergent, dispersant, extreme pressure anti-wear agent, antioxidant preservative, rust inhibitor, pour point depressant and antifoaming agent are added, stirred for 2.5-3.5h to obtain a semi-finished diesel engine oil; then cooled to 45℃, filtered under 0.2MPa positive pressure, and naturally cooled to room temperature to obtain a finished diesel engine oil.

2. The method for preparing an energy-saving diesel engine oil with an ultra-long oil change interval according to claim 1, characterized in that, The raw materials for preparing the finished diesel engine oil comprise the following components by weight fraction: 60-80 parts of base oil, 2-10 parts of viscosity index improver, 1-5 parts of detergent, 1-5 parts of dispersant, 0.2-5 parts of extreme pressure anti-wear agent, 0.5-5 parts of antioxidant preservative, 1-5 parts of rust inhibitor, 0.2-1 parts of pour point depressant and 0.02-1 parts of antifoaming agent.

3. The method of claim 1, wherein the energy-saving, super-long drain diesel engine oil is prepared by adding 0.1 to 1 wt% of the compound of formula (1) to a base oil. The extreme pressure anti-wear agent comprises an oil-soluble ionic liquid anti-wear agent, and optionally one or more of sulfurized isobutylene, molybdenum dialkyldithiocarbamate and triphenyl phosphate. ​ 4. The method of claim 3, wherein the energy-saving, super-long drain diesel engine oil is prepared by adding 0.1 to 1.0 wt% of the compound of formula (I) to a base oil. The oil-soluble ionic liquid anti-wear agent is one or more of phosphorus-containing anti-wear agent and organic molybdenum anti-wear agent.

5. The method of claim 4, wherein the energy-saving, super-long drain diesel engine oil is prepared by adding the additive package to a base oil. The preparation process of the phosphorus-containing anti-wear agent is as follows: A1: N-propylimidazole is reacted with 1-bromon-butane at 75±2℃ for 45-50h, washed and dried to obtain intermediate A; wherein the molar ratio of N-propylimidazole to 1-bromon-butane is 1:1.05; A2: intermediate A is reacted with phosphate under alkaline conditions, washed and dried to obtain the phosphorus-containing anti-wear agent; wherein the molar ratio of intermediate A to phosphate is 1:1.

1.

6. The method of claim 4, wherein the energy-saving, super-long drain diesel engine oil is prepared by adding 0.1 to 1 wt% of the compound of formula (I) to a base oil. The preparation process of the organic molybdenum anti-wear agent is as follows: B1: N-propylimidazole is reacted with 1-bromon-butane at 75±2℃ for 45-50h, washed and dried to obtain intermediate B; wherein the molar ratio of N-propylimidazole to 1-bromon-butane is 1:1.05; B2: intermediate B is reacted with sodium molybdate dihydrate under acidic conditions, washed and dried to obtain the organic molybdenum anti-wear agent; wherein the molar ratio of intermediate B to sodium molybdate dihydrate is 1:1.05-1.

1.

7. The method for preparing an energy-saving diesel engine oil with an ultra-long oil change interval according to claim 1, characterized in that, The base oil is selected from at least two of cPAO, mPAO, ETL synthetic oil and synthetic ester; wherein the synthetic ester is one or more of adipate ester, diisooctyl sebacate and pentaerythritol ester.

8. The method for preparing an energy-saving diesel engine oil with an ultra-long oil change interval according to claim 1, characterized in that, The viscosity index improver is one or two of polymethacrylate, ethylene / propylene copolymer and hydrogenated styrene / diene copolymer.

9. The method for preparing an energy-saving diesel engine oil with an ultra-long oil change interval according to claim 1, characterized in that, The detergent and dispersant are selected from at least two of high-base-value calcium sulfidated alkylphenol, medium-base-value calcium sulfonate, high-molecular-weight polyisobutylene bis succinimide, boronized polyisobutylene bis succinimide and polyisobutylene bis succinimide; The antioxidant preservative is selected from at least two of 4,4'-methylenebis(2,6-di-tert-butyl)phenol, octyl diphenylamine, octyl-N-phenyl-alpha-naphthylamine and zinc dialkyldithiophosphate; The rust inhibitor is one or more of petroleum sodium sulfonate, straight-chain dodecenyl succinic acid, alkenyl succinate and neutral calcium dinonylnaphthalene sulfonate; The pour point depressant is polymethacrylate; The antifoaming agent is one or more of oil-soluble polyether and polyether-modified silicon.

10. A finished diesel engine oil obtained by the process according to any one of claims 1 to 9.

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