Diesel engine lubricating oil composition and preparation method thereof

Abstract

The invention discloses a diesel engine lubricating oil composition and a preparation method thereof, and the diesel engine lubricating oil composition comprises the following components by mass: 5.0%-7.5% of a high temperature detergent, 2.5%-5.4% of a bis-succinimide dispersant, 0.5%-2.0% of a zinc dialkyl dithiophosphate antioxidant preservative, 0.5%-1.5% of an auxiliary antioxidant, 0.5%-1.5% of a 2, 3-dihydro-2, 3, 4-trimethyl-1, 3-pentanediol monoisobutyrate, 0.5%-1.5% of a 2, 3, 4-trimethyl-1, 3-pentanediol monoisobutyrate, 0.5 The lubricating oil composition is prepared by uniformly stirring the following components in percentage by weight: 0.5 to 2.0 percent of 2, 2-dimethyl-7-benzofuryl-A-N-carbamate, 0.2 to 0.5 percent of pour point depressant, 0.0015 to 0.0050 percent of methyl silicone oil anti-foaming agent and the balance of catalytic hydrogenation base oil at the temperature of between 60 and 70 DEG C. The lubricating oil composition can be prepared by uniformly stirring the components at the temperature of between 60 and 70 DEG C. According to the diesel engine oil composition, various components are reasonably compounded, so that mutual inhibition of marine diesel engine oil water separation property, additive washing resistance, detergency and dispersibility, oxidation resistance, wear resistance and the like is solved, and the oil change period of an oil product is greatly prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of diesel engine lubricating oil compositions, and in particular relates to a diesel engine lubricating oil composition. The present invention also relates to a method for preparing the lubricating oil composition. Background Art

[0002] Ship diesel engines are quite different from ordinary marine diesel engines. Ship diesel engines are generally small medium- and high-speed diesel engines with high engine strengthening coefficients and high lubrication system temperatures. They require diesel engine lubricants to have a higher quality grade and excellent high-temperature oxidation resistance, high-temperature cleanliness, lubrication and anti-wear properties. However, the diesel fuel they use is of good quality and has a relatively low sulfur content, which generally does not exceed 0.5%. Therefore, the requirements for the base number of the lubricating oil are relatively low. Civilian ship diesel engines are generally large low-speed diesel engines with high engine power but low strengthening coefficient. They do not require high temperature performance and anti-wear performance of lubricants, but the diesel fuel they use is generally heavy oil, such as residual fuel. The sulfur content of the fuel is relatively high, even reaching more than 3%. The alkalinity value of the lubricant is very high, generally requiring the alkalinity value of the lubricant to be above 30mgKOH / g. Therefore, civil ship diesel engine lubricants generally have no quality grades. Different brands of lubricant products are distinguished according to the alkalinity value, such as No. 30, No. 40, No. 50, No. 60, No. 70, etc. Ship diesel engine lubricants and civil ship diesel engine lubricants are of completely different nature due to different working conditions and cannot be replaced by each other.

[0003] Lubricating oil for ship diesel engines and ordinary land diesel engine oil are also not interchangeable. Considering that a large amount of water may be mixed into ship diesel engines, most ship diesel engines are equipped with centrifugal equipment to separate the water and other impurities mixed into the lubricating oil. This requires the lubricating oil for ship diesel engines to have the ability to quickly separate from water, including water separation and additive water washing resistance. Ordinary land-based diesel engine oil does not have good water separation performance, and will be seriously emulsified after contacting water, which will cause serious reduction in lubrication, rust prevention and other performances. Long-term use will cause irreversible damage to the engine hardware. In order to improve the water separation performance of lubricating oil, a certain amount of demulsifier is usually added to the lubricating oil component to destroy the emulsion layer formed and realize the separation of oil and water as soon as possible. If the amount of demulsifier is too low, the water separation effect is not obvious. If the amount is too high, it is not easy to dissolve, affecting the appearance and transparency of the lubricating oil. How to solve the water separation performance requirements of ship diesel engine lubricating oil is also a major technical difficulty at present.

[0004] At present, the oil change cycle of ship diesel engine lubricating oil is generally short, mostly 300h to 500h. With the increasing demand for ship ocean voyages, the continuous ocean running time of ship diesel engines is required to reach 5000h to 6000h or even longer. The current ship diesel engine oil needs to be replaced more than 10 times. The storage of new lubricating oil and replaced old oil requires a large amount of ship storage space, which seriously restricts the work efficiency and continuous running time of ships in ocean voyages. The invention patent CN02103532.6 applied by China discloses a lubricating oil composition suitable for two-stroke crosshead marine diesel engines, but the composition is only suitable for marine low-speed diesel engines, not for ship diesel engines; China's invention patent CN103184091 discloses a ship universal diesel engine lubricating oil composition, which is suitable for ship diesel engines, has good water separation performance and general performance, and can meet the lubrication needs of ship diesel engines, but the quality grade of the composition is equivalent to API CD level, and the oil change cycle is short, only 500h.

[0005] In summary, there is an urgent need to develop a diesel engine lubricant with a long oil change period and suitable for ships. Summary of the invention

[0006] The purpose of the present invention is to provide a diesel engine lubricating oil composition, which solves the problem of short lubricating oil replacement cycle in the prior art.

[0007] Another object of the present invention is to provide a method for preparing the above diesel engine lubricating oil composition.

[0008] The technical solution adopted by the present invention is that the diesel engine lubricating oil composition is composed of the following components in percentage by mass: 5.0% to 7.5% of high-temperature detergent, 2.5% to 5.4% of bis-succinimide dispersant, 0.5% to 2.0% of dialkyl dithiophosphate zinc antioxidant and preservative, 0.5% to 1.5% of auxiliary antioxidant, 0.5% to 2.0% of 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-methyl-N-yl carbamate, 0.2% to 0.5% of pour point depressant, 0.0015% to 0.0050% of methyl silicone oil antifoaming agent, and the balance is catalytic hydrogenation base oil.

[0009] The invention is characterized in that the high-temperature detergent is composed of sulphurized alkyl phenol salt, low-base sulfonate salt and alkyl salicylate salt, wherein the sulphurized alkyl phenol salt accounts for 25% to 35% by weight, the low-base sulfonate salt accounts for 25% to 35% by weight, and the balance is alkyl salicylate salt;

[0010] The sulphurized alkyl phenol salt is composed of medium alkalinity sulphurized alkyl phenol calcium and high alkalinity sulphurized alkyl phenol calcium. According to the percentage by mass, the medium alkalinity sulphurized alkyl phenol calcium accounts for 30% to 40% by mass, and the remainder is the high alkalinity sulphurized alkyl phenol calcium. The total alkalinity of the medium alkalinity sulphurized alkyl phenol calcium is 130 to 200 mgKOH / g, and the total alkalinity of the high alkalinity sulphurized alkyl phenol calcium is not less than 250 mgKOH / g.

[0011] The low base value sulfonate is any one of petroleum-based calcium sulfonate and synthetic calcium sulfonate, and its total base value is 20 to 35 mgKOH / g;

[0012] The alkyl salicylate is composed of medium-base calcium alkyl salicylate and high-base magnesium alkyl salicylate. Calculated by mass percentage, the medium-base calcium alkyl salicylate accounts for 60% to 70% by mass, and the remainder is high-base magnesium alkyl salicylate. The total alkalinity of the medium-base calcium alkyl salicylate is 160 to 250 mgKOH / g, and the total alkalinity of the high-base magnesium alkyl salicylate is not less than 290 mgKOH / g.

[0013] The zinc dialkyl dithiophosphate antioxidant preservative is any one of butyl octyl zinc dithiophosphate and bis-octyl zinc dithiophosphate.

[0014] The auxiliary antioxidant is any one of butyl octyl diphenylamine and dioctyl diphenylamine.

[0015] The catalytic hydrogenation base oil is composed of a medium component hydrogenation base oil and a heavy component hydrogenation base oil, wherein the mass of the medium component hydrogenation base oil accounts for 70% to 90% and the mass of the heavy component hydrogenation base oil accounts for 10% to 30%; the kinematic viscosity of the medium component hydrogenation base oil at 100°C is 9.0 to 11.0 mm 2 / s, viscosity index is not less than 95, the kinematic viscosity of the heavy component hydrogenated base oil at 100°C is 28.0~34.0mm 2 / s, viscosity index 80~90.

[0016] Another technical solution adopted by the present invention is a method for preparing a diesel engine lubricating oil composition, comprising the following steps:

[0017] Step 1: Weigh the following components by mass percentage: 5.0% to 7.5% of high temperature detergent, 2.5% to 5.4% of bis-succinimide dispersant, 0.5% to 2.0% of zinc dialkyl dithiophosphate antioxidant preservative, 0.5% to 1.5% of auxiliary antioxidant, 0.5% to 2.0% of 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-methyl-N-yl carbamate, 0.2% to 0.5% of pour point depressant, 0.0015% to 0.0050% of methyl silicone oil antifoaming agent, and the remainder is catalytic hydrogenation base oil;

[0018] Step 2: The components weighed in step 1 are heated to 60-70° C. and stirred evenly to obtain a diesel engine lubricating oil composition.

[0019] The present invention is also characterized in that the high-temperature detergent is composed of sulphurized alkyl phenol salt, low-base sulfonate salt and alkyl salicylate salt, wherein the sulphurized alkyl phenol salt accounts for 25% to 35% by weight, the low-base sulfonate salt accounts for 25% to 35% by weight, and the balance is alkyl salicylate salt;

[0020] The sulphurized alkyl phenol salt is composed of medium alkalinity sulphurized alkyl phenol calcium and high alkalinity sulphurized alkyl phenol calcium. According to the percentage by mass, the medium alkalinity sulphurized alkyl phenol calcium accounts for 30% to 40% by mass, and the remainder is the high alkalinity sulphurized alkyl phenol calcium. The total alkalinity of the medium alkalinity sulphurized alkyl phenol calcium is 130 to 200 mgKOH / g, and the total alkalinity of the high alkalinity sulphurized alkyl phenol calcium is not less than 250 mgKOH / g.

[0021] The low base value sulfonate is any one of petroleum-based calcium sulfonate and synthetic calcium sulfonate, and its total base value is 20 to 35 mgKOH / g;

[0022] The alkyl salicylate is composed of medium-base calcium alkyl salicylate and high-base magnesium alkyl salicylate. Calculated by mass percentage, the medium-base calcium alkyl salicylate accounts for 60% to 70% by mass, and the remainder is high-base magnesium alkyl salicylate. The total alkalinity of the medium-base calcium alkyl salicylate is 160 to 250 mgKOH / g, and the total alkalinity of the high-base magnesium alkyl salicylate is not less than 290 mgKOH / g.

[0023] The zinc dialkyl dithiophosphate antioxidant preservative is any one of butyl octyl zinc dithiophosphate and bis-octyl zinc dithiophosphate.

[0024] The auxiliary antioxidant is any one of butyl octyl diphenylamine and dioctyl diphenylamine.

[0025] The catalytic hydrogenation base oil is composed of a medium component hydrogenation base oil and a heavy component hydrogenation base oil, wherein the mass of the medium component hydrogenation base oil accounts for 70% to 90% and the mass of the heavy component hydrogenation base oil accounts for 10% to 30%; the kinematic viscosity of the medium component hydrogenation base oil at 100°C is 9.0 to 11.0 mm 2 / s, viscosity index is not less than 95, the kinematic viscosity of the heavy component hydrogenated base oil at 100°C is 28.0~34.0mm 2 / s, viscosity index 80~90.

[0026] The beneficial effects of the present invention are:

[0027] 1. The present invention balances and solves the mutual inhibition between the water separation property of ship diesel engine oil, the water wash resistance of additives, and the cleaning and dispersing properties, oxidation resistance, and wear resistance by reasonably compounding the components such as high-temperature detergent, ash-free dispersant, antioxidant preservative, auxiliary antioxidant, and additives;

[0028] 2. The composition of the present invention greatly prolongs the oil change cycle of oil products from 500h to 1000h. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a graph showing the kinematic viscosity change of the lubricating oil composition of Example 1 after a 1000-hour ship test;

[0030] Figure 2 This is a graph showing the pH value change of the lubricating oil composition of Example 1 after a 1000-hour ship test;

[0031] Figure 3 This is a graph showing the changes in the wear element content of the lubricating oil composition of Example 1 during a 1000-hour actual ship test. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with specific implementation modes and accompanying drawings.

[0033] A diesel engine lubricating oil composition consists of the following components, measured by mass percentage: 5.0% to 7.5% of a high-temperature detergent, 2.5% to 5.4% of a bis-succinimide dispersant, 0.5% to 2.0% of a zinc dialkyl dithiophosphate antioxidant and preservative, 0.5% to 1.5% of an auxiliary antioxidant, 0.5% to 2.0% of a 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-methyl-N-yl carbamate, 0.2% to 0.5% of a pour point depressant, 0.0015% to 0.0050% of a methyl silicone oil antifoaming agent, and the remainder being a catalytic hydrogenation base oil.

[0034] The high-temperature detergent is composed of sulphurized alkyl phenol salt, low-base sulfonate salt and alkyl salicylate salt. According to the mass percentage, the mass percentage of sulphurized alkyl phenol salt is 25% to 35%, the mass percentage of low-base sulfonate salt is 25% to 35%, and the balance is alkyl salicylate salt.

[0035] The sulfurized alkylphenol salt in the high-temperature detergent component is composed of medium-base sulfurized alkylphenol calcium and high-base sulfurized alkylphenol calcium. According to the mass percentage, the medium-base sulfurized alkylphenol calcium accounts for 30% to 40% by mass, and the remainder is high-base sulfurized alkylphenol calcium. Among them, too high or too low a proportion of medium-base sulfurized alkylphenol calcium will affect the anti-water washing performance and water separation performance of the additive of the composition of the present invention. The total base value of the medium-base sulfurized alkylphenol calcium is 130 to 200 mgKOH / g, and the total base value of the high-base sulfurized alkylphenol calcium is not less than 250 mgKOH / g.

[0036] The low-base sulfonate in the high-temperature detergent component is any one of petroleum-based calcium sulfonate and synthetic calcium sulfonate, and its total base value is 20 to 35 mgKOH / g;

[0037] The alkyl salicylate in the high-temperature detergent component is composed of medium-base calcium alkyl salicylate and high-base magnesium alkyl salicylate. According to the mass percentage, the mass of medium-base calcium alkyl salicylate accounts for 60% to 70%, and the balance is high-base magnesium alkyl salicylate. The total base value of medium-base calcium alkyl salicylate is 160 to 250 mgKOH / g, and the total base value of high-base magnesium alkyl salicylate is not less than 290 mgKOH / g. Among them, too high or too low a proportion of alkyl magnesium salicylate will affect the anti-water washing performance and water separation performance of the additive of the composition of the present invention;

[0038] The zinc dialkyl dithiophosphate antioxidant preservative is any one of butyl octyl zinc dithiophosphate and dioctyl zinc dithiophosphate;

[0039] The auxiliary antioxidant is any one of butyl octyl diphenylamine and dioctyl diphenylamine;

[0040] Among them, in the present invention, 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-methyl-N-ylcarbamate is used as an additive, and its structure is as follows:

[0041]

[0042] The carbamate and benzofuran groups contained in the additive structure can form a conjugated structure, which can timely capture the free radical intermediates generated during the oxidation process of the engine oil, block the oxidation reaction chain, and have a significant anti-oxidation effect; in addition, the additive has good metal adsorption capacity, and can form a firm adsorption film on the surface of the engine piston ring cylinder sleeve friction pair, crankshaft bearing friction pair, etc., to reduce friction and wear. The additive can greatly improve the antioxidant and anti-wear properties of the composition of the present invention, and can effectively extend the oil change cycle.

[0043] The catalytic hydrogenation base oil is composed of the middle component hydrogenation base oil and the heavy component hydrogenation base oil. The mass of the middle component hydrogenation base oil accounts for 70% to 90%. The kinematic viscosity of the middle component hydrogenation base oil at 100°C is 9.0 to 11.0 mm 2 / s, viscosity index is not less than 95, the mass proportion of heavy component hydrogenated base oil is 10% to 30%, and the kinematic viscosity of heavy component hydrogenated base oil at 100°C is 28.0 to 34.0 mm 2 / s, viscosity index is 80~90.

[0044] A method for preparing a diesel engine lubricating oil composition comprises the following steps:

[0045] Step 1: Weigh the following components by mass percentage: 5.0% to 7.5% of high temperature detergent, 2.5% to 5.4% of bis-succinimide dispersant, 0.5% to 2.0% of zinc dialkyl dithiophosphate antioxidant preservative, 0.5% to 1.5% of auxiliary antioxidant, 0.5% to 2.0% of 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-methyl-N-yl carbamate, 0.2% to 0.5% of pour point depressant, 0.0015% to 0.0050% of methyl silicone oil antifoaming agent, and the remainder is catalytic hydrogenation base oil;

[0046] Step 2: heating the components weighed in step 1 to 60-70° C. and stirring evenly to obtain a diesel engine lubricating oil composition;

[0047] In step 1, the high-temperature detergent is composed of 25% to 35% of sulfurized alkylphenol salt, 25% to 35% of low-base sulfonate, and the balance is alkyl salicylate; further, the sulfurized alkylphenol salt in the high-temperature detergent component is composed of medium-base sulfurized alkylphenol calcium and high-base sulfurized alkylphenol calcium, wherein, in terms of mass percentage, the medium-base sulfurized alkylphenol calcium accounts for 30% to 40% by mass, and the balance is high-base sulfurized alkylphenol calcium. Too high or too low a proportion of the medium-base sulfurized alkylphenol calcium will affect the anti-water washing performance and water separation performance of the additive of the composition of the present invention. The total base value of the medium-base sulfurized alkylphenol calcium is 130 to 200 mgKOH / g, and the total base value of the high-base sulfurized alkylphenol calcium is not less than 250 mgKOH / g. OH / g; the low-base sulfonate in the high-temperature detergent component is any one of petroleum-based calcium sulfonate and synthetic calcium sulfonate, and its total base number is 20-35 mgKOH / g; the alkyl salicylate in the high-temperature detergent component is composed of medium-base alkyl salicylate calcium and high-base alkyl salicylate magnesium. According to the mass percentage, the mass of medium-base alkyl salicylate calcium accounts for 60%-70%, and the balance is high-base alkyl salicylate magnesium. The total base number of medium-base alkyl salicylate calcium is 160-250 mgKOH / g, and the total base number of high-base alkyl salicylate magnesium is not less than 290 mgKOH / g. Among them, too high or too low a proportion of alkyl salicylate magnesium will affect the anti-water washing performance and water separation performance of the additive of the composition of the present invention;

[0048] The zinc dialkyl dithiophosphate antioxidant preservative is any one of butyl octyl zinc dithiophosphate and dioctyl zinc dithiophosphate; the auxiliary antioxidant is any one of butyl octyl diphenylamine and dioctyl diphenylamine;

[0049] The catalytic hydrogenation base oil is composed of the middle component hydrogenation base oil and the heavy component hydrogenation base oil. The mass of the middle component hydrogenation base oil accounts for 70% to 90%. The kinematic viscosity of the middle component hydrogenation base oil at 100°C is 9.0 to 11.0 mm 2 / s, viscosity index is not less than 95, the mass proportion of heavy component hydrogenated base oil is 10% to 30%, and the kinematic viscosity of heavy component hydrogenated base oil at 100°C is 28.0 to 34.0 mm 2 / s, viscosity index is 80~90.

[0050] Example 1

[0051] Lubricant: 100%

[0052] Table 1 Composition and ratio of lubricating oil composition of Example 1

[0053] Components content(%) Medium base value sulphurized calcium alkyl phenol 0.6 High base value sulphurized calcium alkyl phenol 1.2 Low base petroleum calcium sulfonate 1.8 Medium base calcium alkyl salicylate 1.5 Overbased magnesium alkyl salicylate 0.9 Bisuccinimide dispersant 4.0 Butyloctyl zinc dithiophosphate 1.5 Butyl octyl diphenylamine 1.0 additive 1.5 Pour Point Depressant 0.3 Methyl silicone oil antifoaming agent 0.002 Base oil margin

[0054] The base oil composition is shown in Table 2:

[0055] Base oil: 100%

[0056] Table 2 Example 1 Base oil composition and ratio

[0057] Components content(%) Medium component hydrogenated base oil 80 Heavy component hydrogenated base oil 20

[0058] The above ingredients were heated to 60° C. and mixed evenly to obtain a lubricating oil composition A. The test results of the physical and chemical properties of the lubricating oil composition A are shown in Table 3.

[0059] Table 3 Physical and chemical properties test results of lubricating oil composition A in Example 1

[0060]

[0061] It can be found from the data in Table 3 that the lubricating oil composition blended in this embodiment has excellent water separation and additive resistance to water washing, and the volume of the emulsion layer after the water separation test is only 0.1 mL; on the other hand, the high-temperature detergency, oxidation resistance and extreme pressure wear resistance are improved. The high-temperature detergency is measured by the coking plate test, and the coking weight is only 23 mg, while the coking weight of ordinary ship diesel engine oil is about 40 mg or more; the PDSC oxidation induction period is tested to be 86 min, far exceeding the ACEA E8-22 heavy-duty diesel engine oil specification requirement of not less than 65 min; the maximum no-seizure load of the SRV test machine can reach 1800 N, while that of ordinary ship diesel engine oil is only about 1200 N.

[0062] The changes in the physical and chemical properties of the lubricating oil composition prepared in this embodiment during the 1000h ship sailing test are as follows: Figures 1 to 3 shown.

[0063] pass Figure 1 It can be seen that the blended lubricating oil composition in this embodiment has been verified by a 1000h actual ship test. The kinematic viscosity of the oil remains stable during the test, and no oxidation viscosity increase occurs. Figure 2It can be seen that the base value has not decayed, the acid value has increased very little, and there is still a very large margin between the pH value, indicating that the oil has excellent alkalinity retention and the ability to inhibit the increase of oxidation acid value; Figure 3 It can be seen that the content of wear elements such as iron, copper, aluminum, lead, etc. is extremely low, indicating that the oil has excellent anti-wear properties.

[0064] In summary, the lubricating oil composition can meet the use requirement of 1000h oil change cycle of marine diesel engines and has the potential to be further extended.

[0065] Example 2

[0066] Lubricant: 100%

[0067] Table 4 Composition and ratio of lubricating oil composition in Example 2

[0068]

[0069]

[0070] The base oil composition is shown in Table 5:

[0071] Base oil: 100%

[0072] Table 5 Example 2 Base oil composition and ratio

[0073] Components content(%) Medium component hydrogenated base oil 70 Heavy component hydrogenated base oil 30

[0074] The above ingredients were heated to 70° C. and mixed evenly to obtain a lubricating oil composition B. The test results of the physical and chemical properties of the blended lubricating oil composition B in this example are shown in Table 6.

[0075] Table 6 Physical and chemical properties test results of lubricant combination B in Example 2

[0076]

[0077]

[0078] It can be found from the data in Table 6 that the lubricating oil composition blended in this embodiment has excellent water separation and additive resistance to water washing, and the volume of the emulsion layer after the water separation test is only 0.1 mL; on the other hand, it improves high-temperature detergency, oxidation resistance and extreme pressure wear resistance. The high-temperature detergency is measured by the coking plate test, and the coking weight is only 20 mg, while the coking weight of ordinary ship diesel engine oil is about 40 mg or more; the PDSC oxidation induction period is tested to be 88 min, far exceeding the ACEA E8-22 heavy-duty diesel engine oil specification requirement of not less than 65 min; the maximum no-seizure load of the SRV test machine can reach 1900 N, while that of ordinary ship diesel engine oil is only about 1200 N.

[0079] The lubricating oil composition prepared in this embodiment has been verified through a 1000-hour actual ship test, and the lubricating oil composition can meet the 1000-hour oil change cycle requirement of a ship diesel engine, and has the potential to be further extended. During the test, the kinematic viscosity of the oil remains stable, and no oxidation viscosity increase occurs.

[0080] Example 3

[0081] Lubricant: 100%

[0082] Table 7 Composition and ratio of lubricating oil composition in Example 3

[0083]

[0084]

[0085] The base oil composition is shown in Table 8:

[0086] Base oil: 100%

[0087] Table 8 Example 3 Base oil composition and ratio

[0088] Components content(%) Medium component hydrogenated base oil 90 Heavy component hydrogenated base oil 10

[0089] The above ingredients were heated to 65° C. and mixed evenly to obtain a lubricating oil composition C. The test results of the physical and chemical properties of the blended lubricating oil composition C in this example are shown in Table 9.

[0090] Table 9 Physical and chemical properties test results of lubricating oil composition C of Example 3

[0091]

[0092]

[0093] It can be found from the data in Table 9 that the lubricating oil composition blended in this embodiment has excellent water separation and additive resistance to water washing, and the volume of the emulsion layer after the water separation test is only 0.1 mL; on the other hand, it improves high-temperature detergency, oxidation resistance and extreme pressure wear resistance. The high-temperature detergency is measured by the coking plate test, and the coking weight is only 25 mg, while the coking weight of ordinary ship diesel engine oil is about 40 mg or more; the PDSC oxidation induction period is tested to be up to 92 min, far exceeding the ACEA E8-22 heavy-duty diesel engine oil specification requirement of not less than 65 min; the maximum no-seizure load of the SRV test machine can reach 1900 N, while that of ordinary ship diesel engine oil is only about 1200 N.

[0094] The lubricating oil composition prepared in this embodiment has been verified through a 1000-hour actual ship test, and the lubricating oil composition can meet the 1000-hour oil change cycle requirement of a ship diesel engine, and has the potential to be further extended. During the test, the kinematic viscosity of the oil remains stable, and no oxidation viscosity increase occurs.

[0095] In summary, the test results of the physical and chemical properties of the lubricating oil composition in each embodiment and the 1000h actual ship test results show that the parameters of the lubricating oil composition blended in Examples 1 to 3 are all within the index range, and on the one hand, it has excellent water separation performance, and on the other hand, it significantly improves the high temperature detergency, oxidation resistance and wear resistance. When the lubricating oil composition blended in each embodiment is used in the actual ship test, the oil change cycle of the oil product can be extended to more than 1000h, which is significantly improved compared with ordinary ship general diesel engine oil.

Claims

1. A diesel engine lubricating oil composition, characterized in that: The invention is composed of the following components in percentage by mass: 5.0% to 7.5% of high-temperature detergent, 2.5% to 5.4% of bis-succinimide dispersant, 0.5% to 2.0% of dialkyl dithiophosphate zinc antioxidant and preservative, 0.5% to 1.5% of auxiliary antioxidant, 0.5% to 2.0% of 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-methyl-N-yl carbamate, 0.2% to 0.5% of pour point depressant, 0.0015% to 0.0050% of methyl silicone oil antifoaming agent, and the balance is catalytic hydrogenation base oil.

2. The diesel engine lubricating oil composition according to claim 1, characterized in that: The high-temperature detergent is composed of sulfurized alkyl phenol salt, low-base sulfonate salt, and alkyl salicylate salt. In terms of mass percentage, the sulfurized alkyl phenol salt accounts for 25% to 35% by mass, the low-base sulfonate salt accounts for 25% to 35% by mass, and the balance is alkyl salicylate salt. The sulphurized alkyl phenol salt is composed of medium alkalinity sulphurized alkyl phenol calcium and high alkalinity sulphurized alkyl phenol calcium. According to the mass percentage, the medium alkalinity sulphurized alkyl phenol calcium accounts for 30% to 40% by mass, and the balance is high alkalinity sulphurized alkyl phenol calcium. The total alkalinity of the medium alkalinity sulphurized alkyl phenol calcium is 130 to 200 mgKOH / g, and the total alkalinity of the high alkalinity sulphurized alkyl phenol calcium is not less than 250 mgKOH / g. The low-base sulfonate is any one of petroleum-based calcium sulfonate and synthetic calcium sulfonate, and its total base value is 20-35 mgKOH / g; The alkyl salicylate is composed of medium-base alkyl salicylate calcium and high-base alkyl salicylate magnesium. According to the mass percentage, the medium-base alkyl salicylate calcium accounts for 60% to 70% by mass, and the remainder is high-base alkyl salicylate magnesium. The total alkalinity of the medium-base alkyl salicylate calcium is 160 to 250 mgKOH / g, and the total alkalinity of the high-base alkyl salicylate magnesium is not less than 290 mgKOH / g.

3. The diesel engine lubricating oil composition according to claim 1, characterized in that: The dialkyl zinc dithiophosphate antioxidant preservative is any one of butyl octyl zinc dithiophosphate and dioctyl zinc dithiophosphate.

4. The diesel engine lubricating oil composition according to claim 1, characterized in that: The auxiliary antioxidant is any one of butyl octyl diphenylamine and dioctyl diphenylamine.

5. The diesel engine lubricating oil composition according to claim 1, characterized in that: The catalytic hydrogenation base oil is composed of a middle component hydrogenation base oil and a heavy component hydrogenation base oil, wherein the middle component hydrogenation base oil accounts for 70% to 90% by weight, and the heavy component hydrogenation base oil accounts for 10% to 30% by weight; the kinematic viscosity of the middle component hydrogenation base oil at 100° C. is 9.0 to 11.0 mm 2 / s, the viscosity index is not less than 95, and the kinematic viscosity of the heavy component hydrogenated base oil at 100°C is 28.0-34.0 mm 2 / s, viscosity index 80~90.

6. A method for preparing a diesel engine lubricating oil composition, characterized in that: The following steps are involved: Step 1: Weigh the following components by mass percentage: 5.0% to 7.5% of high temperature detergent, 2.5% to 5.4% of bis-succinimide dispersant, 0.5% to 2.0% of zinc dialkyl dithiophosphate antioxidant preservative, 0.5% to 1.5% of auxiliary antioxidant, 0.5% to 2.0% of 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-methyl-N-yl carbamate, 0.2% to 0.5% of pour point depressant, 0.0015% to 0.0050% of methyl silicone oil antifoaming agent, and the remainder is catalytic hydrogenation base oil; Step 2: The components weighed in step 1 are heated to 60-70° C. and stirred evenly to obtain a diesel engine lubricating oil composition.

7. The method for preparing the diesel engine lubricating oil composition according to claim 6, characterized in that: The high-temperature detergent is composed of sulfurized alkyl phenol salt, low-base sulfonate salt, and alkyl salicylate salt. In terms of mass percentage, the sulfurized alkyl phenol salt accounts for 25% to 35% by mass, the low-base sulfonate salt accounts for 25% to 35% by mass, and the balance is alkyl salicylate salt. The sulphurized alkyl phenol salt is composed of medium alkalinity sulphurized alkyl phenol calcium and high alkalinity sulphurized alkyl phenol calcium. According to the mass percentage, the medium alkalinity sulphurized alkyl phenol calcium accounts for 30% to 40% by mass, and the balance is high alkalinity sulphurized alkyl phenol calcium. The total alkalinity of the medium alkalinity sulphurized alkyl phenol calcium is 130 to 200 mgKOH / g, and the total alkalinity of the high alkalinity sulphurized alkyl phenol calcium is not less than 250 mgKOH / g. The low-base sulfonate is any one of petroleum-based calcium sulfonate and synthetic calcium sulfonate, and its total base value is 20-35 mgKOH / g; The alkyl salicylate is composed of medium-base calcium alkyl salicylate and high-base magnesium alkyl salicylate. According to the mass percentage, the medium-base calcium alkyl salicylate accounts for 60% to 70% by mass, and the remainder is high-base magnesium alkyl salicylate. The total base value of the medium-base calcium alkyl salicylate is 160 to 250 mgKOH / g, and the total base value of the high-base magnesium alkyl salicylate is not less than 290 mgKOH / g.

8. The method for preparing the diesel engine lubricating oil composition according to claim 6, characterized in that: The dialkyl zinc dithiophosphate antioxidant preservative is any one of butyl octyl zinc dithiophosphate and dioctyl zinc dithiophosphate.

9. The method for preparing the diesel engine lubricating oil composition according to claim 6, characterized in that: The auxiliary antioxidant is any one of butyl octyl diphenylamine and dioctyl diphenylamine.

10. The method for preparing the diesel engine lubricating oil composition according to claim 6, characterized in that: The catalytic hydrogenation base oil is composed of a middle component hydrogenation base oil and a heavy component hydrogenation base oil, wherein the middle component hydrogenation base oil accounts for 70% to 90% by weight, and the heavy component hydrogenation base oil accounts for 10% to 30% by weight; the kinematic viscosity of the middle component hydrogenation base oil at 100° C. is 9.0 to 11.0 mm 2 / s, the viscosity index is not less than 95, and the kinematic viscosity of the heavy component hydrogenated base oil at 100°C is 28.0-34.0 mm 2 / s, viscosity index 80~90.

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