Highly detergent low base number marine diesel engine oil composition and method of making and marine two-stroke diesel engine oil

Abstract

This invention provides a high-purity, low-alkalinity marine diesel engine oil composition and preparation method, as well as a marine two-stroke diesel engine oil, belonging to the field of lubricating oil technology. By weight, the diesel engine oil composition comprises: detergent, 9-23 parts; dispersant, 2-9 parts; antioxidant, 1-5 parts; rust inhibitor, 0.1-1 part; base oil, 62-87.9 parts; the detergent is a mixture of sulfonate and sulfoalkylphenol salt, with a weight ratio of sulfonate to sulfoalkylphenol salt of 1-5:1; the dispersant is selected from succinimide dispersants. This invention possesses excellent comprehensive properties such as detergency, dispersibility, anti-wear properties, and thermal oxidation stability, and has obtained MAN Cat.II certification. It can be used for lubrication of the cylinder parts of marine low-speed two-stroke diesel engines using low-sulfur marine fuel with a sulfur content of less than 0.5%.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil technology, and relates to a high-purity, low-alkalinity marine diesel engine oil composition and preparation method, as well as a marine two-stroke diesel engine oil. Background Technology

[0002] With increasingly stringent environmental regulations limiting the sulfur content of marine fuel oils, a global trend towards low-sulfur marine fuel oils has emerged, posing a significant challenge to marine engine oils. From January 1, 2020, the 0.5% (mass fraction) international sulfur cap took full effect, and from March 1, ships were prohibited from carrying non-compliant fuel oils, although ships equipped with desulfurization equipment were temporarily exempt. The sulfur cap has significantly impacted marine cylinder oils; with the advent of the low-sulfur marine fuel era, low-alkalinity cylinder oils have become the mainstream in the market. In terms of engine technology, in recent years, both domestic and international two-stroke low-speed diesel engines have continuously developed towards high temperature, high pressure, high power, and low lubrication oil consumption, placing higher demands on the detergency, dispersancy, oxidation resistance, and anti-wear properties of cylinder oils. The comprehensive switch to low-sulfur marine fuels has greatly affected the product structure of marine engine oils; lower fuel sulfur content requires the use of low-alkalinity products, and 40BN marine cylinder oil is currently the most suitable matching oil.

[0003] As a crucial lubricating medium for low-speed two-stroke diesel engines, cylinder oil forms a lubricating film in the piston and cylinder liner areas of marine engines (diesel engines), playing roles such as lubrication, friction reduction, acid neutralization, and detergency dispersion to ensure normal engine operation and thus provide power to the ship. With the development of marine engine technology and increasingly stringent environmental regulations, the performance of marine cylinder oils is constantly being updated and upgraded. In the early stages of the transition to low-sulfur marine fuel, some marine engines experienced severe carbon buildup, and even piston ring seizure. In 2020, MAN, a leading international manufacturer of low-speed marine engines, classified marine cylinder oils into two grades, Cat I and Cat II, in a technical circular (Service Letter SL2020-694) (Cat II offering better detergency and suitable for all MAN marine engine models). MAN plans to discontinue all Cat I-grade marine cylinder oils by 2026 to further introduce the high-cleanliness 40BN cylinder oil, designed for low-sulfur fuels, to meet market demand.

[0004] Against this backdrop, there is a need to further improve the overall performance of marine cylinder oils, especially their high-temperature detergency and dispersancy properties, to meet the lubrication requirements of low-speed two-stroke marine engines. The performance of marine cylinder oils is related to the selection and proportion of additives, and the various additives have synergistic or antagonistic effects, which need to be comprehensively considered in the formulation system.

[0005] Chinese Invention Patent Publication CN115305134A discloses a low-alkalinity marine cylinder oil composition, which consists of the following components by weight: 6-20 parts detergent; 0.5-5 parts dispersant; 0-5 parts antioxidant; 70-90 parts base oil; the composition has a calcium content of not less than 10000ppm, an alkalinity of not less than 30mgKOH / g and not more than 50mgKOH / g, and can meet the technical requirements for lubrication of marine low-speed two-stroke diesel engines using fuel with a sulfur content of less than 0.5%, and can be used for lubrication of its cylinder parts.

[0006] Chinese Invention Patent Publication CN117925303A discloses a high-antioxidant, low-alkalinity marine cylinder oil composition, which comprises the following components by weight: 10-25 parts detergent; 0.5-10 parts dispersant; 0.5-5 parts antioxidant; 70-85 parts base oil; the composition has an alkalinity of 30-50 mg KOH / g; the composition has a calcium content of not less than 16000 ppm; the detergent includes sulfonates and sulfurized alkylphenol salts, with a weight ratio of sulfonates to sulfurized alkylphenol salts of 5.5-10; suitable for lubrication of the cylinder parts of marine low-speed two-stroke diesel engines using fuel with a sulfur content of less than 0.5%.

[0007] However, the overall performance of the cylinder oil composition disclosed above, such as detergency, dispersibility, anti-wear properties, and thermal oxidation stability, is not excellent enough and there is still room for improvement. In addition, it has not obtained the internationally renowned two-stroke manufacturer MAN Cat.II certification, and the manufacturer does not recommend its use in its Mark 9 and above models. Summary of the Invention

[0008] In order to solve the above-mentioned problems in the prior art, the technical problem to be solved by the present invention is to improve the comprehensive performance of low-alkalinity marine low-speed (engine speed below 105 r / min) diesel engine oil, such as detergency, dispersancy, anti-wear and oxidation stability, so as to meet the MAN Cat.II technical level requirements and provide its application in low-speed two-stroke diesel engines.

[0009] This invention provides a high-purity, low-alkalinity marine low-speed diesel engine oil composition, comprising, by weight, a detergent, a dispersant, an antioxidant, a rust inhibitor, and a base oil; wherein the detergent is a mixture of sulfonate and sulfoalkylphenol salt, with a weight ratio of sulfonate to sulfoalkylphenol salt of 1 to 5:1; the dispersant is selected from succinimide dispersants; and the weight ratio of the dispersant to the detergent is 1:2 to 5.

[0010] As a preferred technical solution, the diesel engine oil composition comprises, by weight, the following components: detergent, 9-23 parts; dispersant, 2-9 parts; antioxidant, 1-5 parts; rust inhibitor, 0.1-1 part; and base oil, 62-87.9 parts.

[0011] As a preferred technical solution, the diesel engine oil composition comprises, by weight, the following components: detergent, 13-21 parts; dispersant, 4-6 parts; antioxidant, 1-4 parts; rust inhibitor, 0.1-0.5 parts; and base oil, 68.5-81.9 parts.

[0012] As a preferred technical solution, the diesel engine oil composition has a calcium content of not less than 20,000 ppm and an alkalinity of not less than 35 mg KOH / g and not more than 45 mg KOH / g.

[0013] In the above technical solution, preferably, the diesel engine oil composition comprises the following components by weight: 13 to 21 parts detergent, 4 to 6 parts dispersant, 1 to 4 parts antioxidant, 0.1 to 0.5 parts rust inhibitor, and 68.5 to 81.9 parts base oil.

[0014] In the above technical solution, preferably, the sulfonate in the detergent is selected from at least one of petroleum sulfonate calcium and synthetic calcium sulfonate; the petroleum sulfonate calcium is selected from at least one of low-alkalinity petroleum sulfonate calcium, medium-alkalinity petroleum sulfonate calcium, or high-alkalinity petroleum sulfonate calcium; and the synthetic calcium sulfonate calcium is selected from at least one of low-alkalinity synthetic calcium sulfonate calcium, medium-alkalinity synthetic calcium sulfonate calcium, high-alkalinity synthetic calcium sulfonate calcium, or ultra-high-alkalinity synthetic calcium sulfonate calcium. Low-alkalinity calcium petroleum sulfonate has an alkalinity of 20–30 mg KOH / g, medium-alkalinity calcium petroleum sulfonate has an alkalinity of 145–200 mg KOH / g, and high-alkalinity calcium petroleum sulfonate has an alkalinity of 300–350 mg KOH / g; low-alkalinity synthetic calcium sulfonate has an alkalinity of 20–30 mg KOH / g, medium-alkalinity synthetic calcium sulfonate has an alkalinity of 145–200 mg KOH / g, high-alkalinity synthetic calcium sulfonate has an alkalinity of 300–350 mg KOH / g, and ultra-high-alkalinity synthetic calcium sulfonate has an alkalinity of ≥395 mg KOH / g.

[0015] In the above technical solution, preferably, the alkylphenol salt in the detergent is selected from at least one of medium-alkalinity alkylphenol calcium sulfide, high-alkalinity alkylphenol calcium sulfide, and ultra-high-alkalinity alkylphenol calcium sulfide. The alkalinity of medium-alkalinity alkylphenol calcium sulfide is 145–245 mg KOH / g, the alkalinity of high-alkalinity alkylphenol calcium sulfide is 245–295 mg KOH / g, and the alkalinity of ultra-high-alkalinity alkylphenol calcium sulfide is ≥295 mg KOH / g.

[0016] In the above technical solution, preferably, the dispersant is selected from at least one of high molecular weight polyisobutylene succinimide, diene succinimide, monoalkenyl succinimide, high nitrogen diene succinimide, and boronized succinimide;

[0017] In the above technical solution, preferably, the antioxidant is selected from at least two of amine antioxidants, sulfur-phosphorus zinc salts, carbamates, phenolic esters, and thioether antioxidants, and the antioxidant includes at least sulfur-phosphorus zinc salts.

[0018] In the above technical solution, preferably, the rust inhibitor oil is selected from at least one of dinonylnaphthalenesulfonic acid metal salt, zinc naphthenate, barium petroleum sulfonate, and alkenyl succinic acid.

[0019] In the above technical solution, preferably, the base oil is selected from at least one of HVI Group I base oil or HVI Group II base oil.

[0020] Another aspect of the present invention provides a method for preparing any of the above-mentioned diesel engine oil compositions, comprising the step of mixing the components at 50°C to 60°C to obtain the diesel engine oil composition.

[0021] One specific embodiment of the present invention involves adding detergent, dispersant, antioxidant, and rust inhibitor to base oil at a ratio of 50°C to 60°C, stirring for 1 to 2 hours until completely dissolved, to obtain the diesel engine oil composition described above.

[0022] This invention relates to a high-purity, low-alkalinity marine low-speed diesel engine oil composition, which can be used to lubricate the cylinder parts of marine low-speed two-stroke diesel engines that use fuels with a sulfur content of less than 0.5%.

[0023] In another aspect, the present invention provides a marine two-stroke diesel engine oil containing any of the above-mentioned diesel engine oil compositions, particularly for use in marine low-speed two-stroke engines.

[0024] In the above technical solution, preferably, the sulfur content in the ship's fuel is less than 0.5%. Fuel with a sulfur content of less than 0.5% is marine residual fuel that meets the specifications for marine residual fuel as specified in ISO 8217.

[0025] This invention provides a high-purity, low-alkalinity marine low-speed diesel engine oil composition, which has excellent comprehensive properties such as detergency, dispersancy, anti-wear, and thermal oxidation stability. It has obtained MAN Cat.II certification from a well-known international two-stroke manufacturer through 2000 hours of sea trials and 2000 hours of confirmation trials. It is more suitable for the lubrication of cylinder parts of marine low-speed two-stroke diesel engines with low sulfur marine fuel containing less than 0.5% sulfur. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0027] In the embodiments and comparative examples of this invention, the sources of the raw material components are:

[0028] Cleaning agent:

[0029] Ultra-high base value synthetic calcium sulfonate T106D, base value 410, purchased from Jinzhou Kangtai Lubricating Oil Additives Co., Ltd.

[0030] High-base-value synthetic calcium sulfonate T106B, base value 316, was purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0031] High-base-value alkylphenol calcium S206, base value 280, purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0032] Medium-alkali-value synthetic calcium sulfonate T105, alkali value 160, purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0033] Low-base-value synthetic calcium sulfonate T104B, base value 25, purchased from Wuxi Southern Petroleum Additives Co., Ltd.; Dispersant:

[0034] Polyisobutylene succinimide T161 was purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0035] Monoalkenyl succinimide T151 was purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0036] Diene-succinimide T154 was purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0037] Antioxidants:

[0038] Phenolic ester antioxidant T508 was purchased from Jinzhou Runda Chemical Co., Ltd.

[0039] T205, a secondary alcoholic zinc salt of thiophosphoric acid, was purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0040] T202, a zinc salt of thiophosphoric butoctyl ester, was purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0041] Alkyl diphenylamine T534 was purchased from Jinzhou Kangtai Lubricating Oil Additives Co., Ltd.

[0042] The thioether-type antioxidant T535 was purchased from Jinzhou Kangtai Lubricating Oil Additives Co., Ltd.

[0043] T203, a zinc thiophosphate dioctyl zinc salt, was purchased from Wuxi Southern Petroleum Additives Co., Ltd.

[0044] Zinc naphthenate T704 was purchased from Suzhou Sanli Special Additives Co., Ltd.

[0045] Dinonylnaphthalenesulfonic acid metal salt T705 was purchased from Suzhou Sanli Special Additives Co., Ltd.

[0046] The performance of the diesel engine oil compositions in the embodiments and comparative examples of this invention was determined according to the following method:

[0047] The high-temperature detergency and thermal oxidation stability of the oil were investigated using the compositions of the examples or comparative examples as test samples and the Komatsu heat pipe test (JPI-5S-55-99) was conducted at a temperature of 320°C for 16 hours.

[0048] The dispersibility of marine low-speed diesel engine oil compositions for low-sulfur fuel oil was determined using the filter paper spot dispersion test (ASTM D7899). The marine low-speed diesel engine oil composition was mixed evenly with a certain proportion of low-sulfur fuel oil and then dropped onto specially prepared filter paper. After being placed in an 80°C oven for 1 hour, the mixture was photographed and rapidly measured using a DT100 dispersibility tester. The dispersibility value (0–100, ideal value 100) characterizes the degree of dispersion of suspended matter in the oil spot; a higher value indicates better dispersibility of the test oil.

[0049] The thermal oxidation stability of the samples was evaluated by the oxidation induction period determination method (pressure differential scanning calorimetry) (SH / T 0719). The test temperature was 210℃ and the pressure was 3.5MPa.

[0050] The extreme pressure anti-wear properties of the oil were investigated using the wear scar diameter test (ASTM D4172). The test conditions were: rotation speed 1800 r / min, pressure 392 N, time 60 min, and temperature 75 ℃.

[0051] Example 1

[0052] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the high-purity, low-alkalinity marine low-speed diesel engine oil composition.

[0053] Example 2

[0054] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the high-purity, low-alkalinity marine low-speed diesel engine oil composition.

[0055] Example 3

[0056] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the high-purity, low-alkalinity marine low-speed diesel engine oil composition.

[0057] Example 4

[0058] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the high-purity, low-alkalinity marine low-speed diesel engine oil composition.

[0059] Example 5

[0060] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the high-purity, low-alkalinity marine low-speed diesel engine oil composition.

[0061] Comparative Example 1

[0062] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the diesel engine oil composition.

[0063] Comparative Example 2

[0064] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the diesel engine oil composition.

[0065] Comparative Example 3

[0066] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the diesel engine oil composition.

[0067] Comparative Example 4

[0068] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the diesel engine oil composition.

[0069] Comparative Example 5

[0070] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the diesel engine oil composition.

[0071] Comparative Example 6

[0072] Preparation process: Mix the additives and base oil, and stir the mixture including each raw material component at 60°C for 1 hour until completely homogeneous to obtain the diesel engine oil composition.

[0073] Table 1. Formulations of Examples and Comparative Examples

[0074]

[0075]

[0076] Table 2 Test data for the examples and comparative examples

[0077]

[0078] The comparison data between the examples and comparative examples show that the comparison of the results of Komatsu heat pipe, oxidation induction period, filter paper spot dispersion test, and wear scar diameter indicates that the high-purity, low-alkalinity marine low-speed diesel engine oil composition obtained by the present invention has achieved very good technical effects and has excellent detergency, dispersibility, anti-wear properties, and thermal oxidation stability.

[0079] The diesel engine oil composition of Example 2 passed 2000 hours of sea trials and 2000 hours of validation trials on a MAN Mark 9 engine, a model manufactured by the internationally renowned two-stroke engine manufacturer, and obtained the MAN Cat.II certification certificate issued by the manufacturer. The comparative examples, however, failed due to insufficient detergency.

[0080] Any numerical value mentioned in this invention, if there is only a two-unit interval between any minimum and any maximum value, includes all values ​​that increase by one unit each time from the minimum to the maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, or time, is stated as 50–90, in this specification it means specifically listing values ​​such as 51–89, 52–88, ..., 69–71, and 70–71. For non-integer values, it may be appropriately considered that a unit is 0.1, 0.01, 0.001, or 0.0001. These are merely some specifically specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0081] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A diesel engine oil composition, comprising the following components: Detergents, dispersants, antioxidants, rust inhibitors, and base oils; The detergent is a mixture of sulfonate and sulfide alkylphenol salt; The weight ratio of the sulfonate to the sulfoalkylphenolate is 1 to 5:1; The dispersant is selected from succinimide dispersants; The weight ratio of the dispersant to the detergent is 1:2 to 5.

2. The diesel engine oil composition according to claim 1, characterized in that, The diesel engine oil composition comprises, by weight, the following components: Cleaning agent, 9–23 parts; Dispersant, 2-9 parts; Antioxidant, 1-5 parts; Rust inhibitor, 0.1 to 1 part; Base oil, 62–87.9 parts; And / or, by weight, the diesel engine oil composition comprises the following components: Cleaning agent, 13-21 parts; Dispersant, 4-6 parts; Antioxidant, 1-4 parts; Rust inhibitor, 0.1 to 0.5 parts; Base oil, 68.5–81.9 parts.

3. The diesel engine oil composition according to claim 1 or 2, characterized in that, The diesel engine oil composition has a calcium content ≥16000ppm and an alkalinity of 35mgKOH / g ≤ 45mgKOH / g.

4. The diesel engine oil composition according to claim 1, 2, or 3, characterized in that, The sulfonate is selected from at least one of petroleum calcium sulfonate and synthetic calcium sulfonate; And / or, the calcium petroleum sulfonate is selected from at least one of low-alkalinity calcium petroleum sulfonate, medium-alkalinity calcium petroleum sulfonate, or high-alkalinity calcium petroleum sulfonate; the alkalinity of low-alkalinity calcium petroleum sulfonate is 20-30 mg KOH / g, the alkalinity of medium-alkalinity calcium petroleum sulfonate is 145-200 mg KOH / g, and the alkalinity of high-alkalinity calcium petroleum sulfonate is 300-350 mg KOH / g; And / or, the synthetic calcium sulfonate in the detergent is selected from at least one of low-alkalinity synthetic calcium sulfonate, medium-alkalinity synthetic calcium sulfonate, high-alkalinity synthetic calcium sulfonate, or ultra-high-alkalinity synthetic calcium sulfonate; the alkalinity of low-alkalinity synthetic calcium sulfonate is 20-30 mgKOH / g, the alkalinity of medium-alkalinity synthetic calcium sulfonate is 145-200 mgKOH / g, the alkalinity of high-alkalinity synthetic calcium sulfonate is 300-350 mgKOH / g, and the alkalinity of ultra-high-alkalinity synthetic calcium sulfonate is ≥395 mgKOH / g; The alkylphenol salt in the detergent is selected from at least one of medium-alkalinity alkylphenol calcium sulfide, high-alkalinity alkylphenol calcium sulfide, and ultra-high-alkalinity alkylphenol calcium sulfide; the alkalinity of medium-alkalinity alkylphenol calcium sulfide is 145-245 mgKOH / g, the alkalinity of high-alkalinity alkylphenol calcium sulfide is 245-295 mgKOH / g, and the alkalinity of ultra-high-alkalinity alkylphenol calcium sulfide is ≥295 mgKOH / g.

5. The diesel engine oil composition according to any one of claims 1-4, characterized in that, The dispersant is selected from at least one of high molecular weight polyisobutylene succinimide, diene succinimide, monoalkenyl succinimide, high nitrogen diene succinimide, and boronized succinimide; the molecular weight of the high molecular weight polyisobutylene succinimide is 500 to 5000.

6. The diesel engine oil composition according to any one of claims 1-5, characterized in that, The antioxidant contains a sulfur-phosphorus type zinc salt; The antioxidants also include at least one of amine antioxidants, carbamate antioxidants, phenolic ester antioxidants, and thioether antioxidants.

7. The diesel engine oil composition according to any one of claims 1-6, characterized in that, The rust inhibitor oil is selected from at least one of dinonylnaphthalene sulfonate metal salt, zinc naphthenate, barium petroleum sulfonate, and alkenyl succinic acid.

8. A method for preparing the diesel engine oil composition according to any one of claims 1-7, comprising the steps of: The components are mixed at 50°C to 60°C to obtain the diesel engine oil composition.

9. Marine two-stroke diesel engine oil, comprising the diesel engine oil composition according to any one of claims 1-7.

10. The marine two-stroke diesel engine oil according to claim 9, characterized in that, The sulfur content in the ship's fuel is less than 0.5%.

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