Marine four-stroke methanol engine lubricating oil and preparation method and application thereof

Abstract

The invention relates to the technical field of lubricating oil, in particular to marine four-stroke methanol engine lubricating oil and a preparation method and application thereof. The marine four-stroke methanol engine lubricating oil is prepared from the following components in parts by weight: 80 to 95 parts of mineral oil, 1 to 5 parts of salicylate, 0 to 2.5 parts of sulfurized alkyl phenate, 3.5 to 4.5 parts of succinimide, 0.5 to 1.2 parts of zinc dioctyl dithiophosphate, 0.1 to 0.5 part of zinc butyl octyl dithiophosphate, 0 to 0.5 part of amine type antioxidant and 0.01 to 0.1 part of anti-foaming agent. The low-ash-content alkali-retaining agent has the advantages of being good in alkali-retaining performance, oxidation resistance and corrosion resistance and low in ash content.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lubricating oil, in particular to a marine four-stroke methanol engine lubricating oil and a preparation method and application thereof. BACKGROUND

[0002] At present, the replacement of traditional fuel by new clean energy fuel for marine has become an important trend, and the marine methanol fuel is expected to become one of the main clean energy in the future due to its wide source, low production cost, strong anti-knock ability, large latent heat of vaporization and other advantages, so the application market prospect of methanol engine oil in the field of marine engine is huge.

[0003] However, during the operation of the marine engine, the mixture of combustion by-products such as formic acid, methanol and water produced by the combustion of methanol fuel is easy to cause corrosion of the engine cylinder sleeve piston ring, and to cause attenuation of the base retention performance of the lubricating oil, so it is necessary to provide a special lubricating oil for the marine four-stroke methanol engine.

[0004] Chinese patent publication No. CN102851102A discloses a methanol gasoline engine special lubricating oil and a preparation method thereof, which is made of the following raw materials by weight: metal rust inhibitor 0.5-1 part, antioxidant 0.3-0.5 part, metal detergent 3-6 parts, viscosity index improver 3-5 parts, metal corrosion inhibitor 2-3 parts, metal extreme pressure anti-wear agent 2-6 parts, dispersant 1-3 parts, and base oil 80-90 parts. The lubricating oil has the advantages of high oxidation resistance and corrosion resistance, good high temperature lubricity, good alcohol resistance, and the preparation method is simple. However, the lubricating oil is mainly used for lubricating high-speed engine operation, and since the marine engine and the passenger car engine are different in engine structure, fuel oil use and operating conditions, the selection of the lubricating oil is also different, and the passenger car lubricating oil is not enough to meet the lubricating demand of marine oil.

[0005] CN115505443A discloses a lubricating oil composition suitable for methanol engine, preparation method and application thereof, mainly solves the problem that the detergent property, anti-wear property and water separation property of medium-speed engine oil used on methanol engine are not excellent. The lubricating oil composition suitable for methanol engine, by weight fraction, consists of: a) 0.1-10 parts of detergent; b) 0.1-10 parts of dispersant; c) 0.1-10 parts of antioxidant; d) 0.1-10 parts of rust inhibitor; e) 0.1-10 parts of anti-emulsifier; f) 0.001-1 parts of antifoaming agent; g) 65-98 parts of base oil, preferably solves the problem, can be used for lubrication and sealing of four-stroke medium-speed cylindrical piston methanol engine. However, the base retention property, antioxidant property and corrosion resistance of the lubricating oil composition need to be further improved, and the ash content of the metal salt such as detergent in the lubricating oil composition is high, which can aggravate the wear of engine parts, leading to the decrease of lubricating property, and the content of exhaust gas pollutants is high.

[0006] Therefore, it is necessary to develop a marine four-stroke methanol engine lubricating oil and its preparation method and application which can solve the above technical problems. SUMMARY

[0007] The purpose of the present application is to overcome the shortcomings of the prior art and provide a marine four-stroke methanol engine lubricating oil with good base retention property, antioxidant property and corrosion resistance, low ash content and its preparation method and application.

[0008] The present application is realized by the following technical solutions:

[0009] The present application provides a marine four-stroke methanol engine lubricating oil, which consists of the following components by weight fraction: mineral oil 80-95 parts, salicylate 1-5 parts, sulfided alkyl phenate 0-2.5 parts, succinimide 3.5-4.5 parts, zinc bis-octyl dithiophosphate 0.5-1.2 parts, zinc butyl-octyl dithiophosphate 0.1-0.5 parts, amine antioxidant 0-0.5 parts and antifoaming agent 0.01-0.1 parts.

[0010] Preferably, the marine four-stroke methanol engine lubricating oil comprises the following components by weight fraction: mineral oil 90-95 parts, salicylate 1-3 parts, sulfided alkyl phenate 0.2-0.5 parts, succinimide 3.5-4.5 parts, zinc bis-octyl dithiophosphate 0.5-1.2 parts, zinc butyl-octyl dithiophosphate 0.1-0.5 parts, amine antioxidant 0-0.5 parts and antifoaming agent 0.01-0.1 parts.

[0011] Preferably, the salicylate comprises at least one of calcium alkyl salicylate and magnesium alkyl salicylate.

[0012] Preferably, the sulfide alkyl phenate is calcium sulfide alkyl phenate.

[0013] Preferably, the amine type antioxidant includes benzene diamine, diphenylamine and the like, and is further preferably at least one of alkyl diphenylamine and bis octyl diphenylamine.

[0014] Preferably, the anti-foaming agent includes a silicon type anti-foaming agent.

[0015] The second aspect of the present application provides a preparation method of the marine four-stroke methanol engine lubricating oil, comprising the following steps:

[0016] The mineral oil is added into a blending kettle, and then the salicylate, sulfide alkyl phenate, succinimide, bis octyl zinc dithiophosphate, butyl octyl zinc dithiophosphate, and amine type antioxidant are added into the blending kettle for first blending, and then the anti-foaming agent is added for second blending, and the marine four-stroke methanol engine lubricating oil is obtained.

[0017] Preferably, the first blending process parameters are: mixing and stirring for 1-2 hours under the temperature condition of 65±5℃; and the second blending process parameters are: mixing and stirring for 2-4 hours under the temperature condition of 65±5℃.

[0018] The third aspect of the present application provides an application of the marine four-stroke methanol engine lubricating oil in a marine four-stroke methanol engine.

[0019] The present application has the following advantages:

[0020] Compared with the conventional lubricating oil, the marine four-stroke methanol engine lubricating oil has good base retention performance, excellent water separation performance, good corrosion resistance and wear resistance.

[0021] The present application uses bis octyl zinc dithiophosphate, butyl octyl zinc dithiophosphate, and amine type antioxidant to provide partial base value, excellent base retention performance, good wear resistance, excellent oxidation resistance and water separation performance, and low ash value, which contributes to the anti-knock and emission requirements of the engine. DETAILED DESCRIPTION

[0022] The present application will be further described in conjunction with specific embodiments, and the advantages and characteristics of the present application will be more apparent with the description. However, these embodiments are only exemplary and do not constitute any limitation on the scope of the present application. Those skilled in the art should understand that the details and forms of the technical solutions of the present application can be modified or replaced without departing from the spirit and scope of the present application, and such modifications and replacements all fall within the protection scope of the present application.

[0023] Example 1

[0024] The mineral base oil is added into the blending kettle according to the content in Table 1 by mass percentage; then the salicylate, succinimide, zinc bis-octyl dithiophosphate, zinc dioctyl dithiophosphate are added into the blending kettle according to the content by mass percentage; fully mixed and stirred for 1 hour at 65℃, then the antifoaming agent is added and fully mixed and stirred for 2 hours, and the blending is completed.

[0025] Example 2

[0026] The mineral base oil is added into the blending kettle according to the content in Table 1 by mass percentage

[0027] The salicylate, sulfized alkyl phenate, succinimide, zinc bis-octyl dithiophosphate, zinc dioctyl dithiophosphate, amine antioxidant are added into the blending kettle according to the content by mass percentage; fully mixed and stirred for 2 hours at 60℃, then the antifoaming agent is added and fully mixed and stirred for 4 hours, and the blending is completed.

[0028] Example 3

[0029] The mineral base oil is added into the blending kettle according to the content in Table 1 by mass percentage; then the salicylate, sulfized alkyl phenate, succinimide, zinc bis-octyl dithiophosphate, zinc dioctyl dithiophosphate, amine antioxidant are added into the blending kettle according to the content by mass percentage; fully mixed and stirred for 1 hour at 70℃, then the antifoaming agent is added and fully mixed and stirred for 2 hours, and the blending is completed.

[0030] Example 4

[0031] The mineral base oil is added into the blending kettle according to the content in Table 1 by mass percentage; then the salicylate, sulfized alkyl phenate, succinimide, zinc bis-octyl dithiophosphate, zinc dioctyl dithiophosphate, amine antioxidant are added into the blending kettle according to the content by mass percentage; fully mixed and stirred for 1 hour at 65℃, then the antifoaming agent is added and fully mixed and stirred for 2 hours, and the blending is completed.

[0032] Example 5

[0033] The mineral base oil is added into the blending kettle according to the content in Table 1 by mass percentage; then the salicylate, sulfized alkyl phenate, succinimide, zinc bis-octyl dithiophosphate, zinc dioctyl dithiophosphate, amine antioxidant are added into the blending kettle according to the content by mass percentage; fully mixed and stirred for 1 hour at 65℃, then the antifoaming agent is added and fully mixed and stirred for 2 hours, and the blending is completed.

[0034] Table 1 Component content table of each example

[0035]

[0036] Comparative Example 1

[0037] The difference from Example 5 is that the zinc dioctyldithiophosphate is not contained, the zinc butyl octyl dithiophosphate is 1.3 parts, and the rest of the conditions are the same.

[0038] Comparative Example 2

[0039] The difference from Example 5 is that the zinc dioctyldithiophosphate is not contained, the zinc butyl octyl dithiophosphate is 1.3 parts, and the rest of the conditions are the same.

[0040] Comparative Example 3

[0041] The difference from Example 5 is that the zinc butyl octyl dithiophosphate is replaced by the same amount of zinc isopropyl isooctyl dithiophosphate, and the rest of the conditions are the same.

[0042] According to SH / T 0754-2005 Corrosion Performance Evaluation Method of Diesel Engine Oil at 135°C, the mixture of 1% methanol, 0.5% formic acid and 0.5% water (based on the mass percentage of the sample, the comparative sample or the reference oil) is added to the sample, the comparative sample and the reference oil, and the simulation experiment is evaluated. The reference oil is a traditional marine four-stroke low base engine lubricating oil, and the results are shown in Table 2.

[0043] Table 2 Simulation Experiment Results

[0044]

[0045]

[0046] Note: 1. The additive element change value (calcium element, phosphorus element) is: new oil element value - element value after corrosion test;

[0047] 2. The corrosion element value is: the metal content in the test oil after the test is completed;

[0048] 3. ICP: Inductively Coupled Plasma Emission Spectrometer.

[0049] 4. Water separation / mL, water layer: not less than 1.2 mL; emulsion layer: not less than 0.5 mL (Q / SY RH 2014-2020).

[0050] The calcium element change amount in the above simulation experiment result analysis is used to detect the base value decay of the experimental oil affected by formic acid, water and other pollutants; the phosphorus element content change is used to detect the evaluation of the antioxidant extraction of methanol, water and other pollutants, causing the evaluation of the antioxidant performance decay of the experimental oil; the corrosion elements Cu, Sn and Pb content reflects the corrosion performance of methanol fuel and its combustion by-products on engine metal parts; the water separation performance test shows the influence of the water generated by methanol combustion on the water separation performance of the lubricating oil; the four-ball long wear test tests the influence of methanol experimental oil on the anti-wear performance of methanol fuel and its by-products formic acid, water and the like; the sulfate ash content: the ash content after complete combustion is too high, which will aggravate the wear of engine parts; the base value decrease rate % and the change rate % of the kinematic viscosity (100℃) are used to represent the overall performance decay of the experimental oil.

[0051] The base retention performance, antioxidant performance and corrosion resistance of the marine four-stroke methanol engine lubricating oil of examples 1-5 are better than those of the reference oil, and the comprehensive performance of example 5 is better. The present application reduces the emission of pollutants while having excellent performance: too high ash content will cause carbon deposition, and has a negative impact on engine particulate matter emission. The reference oil methanol special oil does not meet the emission requirements of particulate matter in the standard of “Limits and Measurement Methods for Exhaust Emission from Marine Engine (China First and Second Stage)” (GB 15097-2016), and needs to be screened for ash-free additives for formula development to reduce the ash content.

[0052] Compared with example 5, the results of comparative examples 1-3 significantly decreased in various aspects by changing the composition of sulfur-phosphorus type zinc salt. It is shown that only by using double octyl zinc dithiophosphate and butyl octyl zinc dithiophosphate for compounding, excellent anti-wear ability, better base value, kinematic viscosity retention ability, excellent antioxidant performance, water separation performance and low ash content can be achieved.

[0053] The above detailed description is a specific description of one of the feasible embodiments of the present application, and this embodiment is not used to limit the patent scope of the present application. Any equivalent implementation or change without departing from the present application shall be included in the scope of the technical solutions of the present application.

Claims

1. A marine four-stroke methanol engine lubricating oil, characterized in that, Based on parts by weight, it consists of the following components: 80-95 parts mineral oil, 1-5 parts salicylate, 0-2.5 parts sulfide alkylphenol salt, 3.5-4.5 parts succinimide, 0.5-1.2 parts bis(octyl)dithiophosphate zinc, 0.1-0.5 parts butyl(octyl)dithiophosphate zinc, 0-0.5 parts amine antioxidant, and 0.01-0.1 parts antifoaming agent.

2. The marine four-stroke methanol engine lubricating oil according to claim 1, characterized in that, The product comprises the following components by weight: 90-95 parts mineral oil, 1-3 parts salicylate, 0.2-0.5 parts sulfide alkylphenol salt, 3.5-4.5 parts succinimide, 0.5-1.2 parts bis(octyl)dithiophosphate zinc, 0.1-0.5 parts butyl(octyl)dithiophosphate zinc, 0-0.5 parts amine antioxidant, and 0.01-0.1 parts antifoaming agent.

3. The marine four-stroke methanol engine lubricating oil according to claim 1, characterized in that, The salicylates include at least one of alkyl salicylate calcium and alkyl salicylate magnesium.

4. The marine four-stroke methanol engine lubricating oil according to claim 1, characterized in that, The sulfidated alkylphenol salt is sulfidated alkylphenol calcium.

5. The marine four-stroke methanol engine lubricating oil according to claim 1, characterized in that, The amine-type antioxidants include at least one of alkyl diphenylamine and bis(octyl)diphenylamine.

6. The marine four-stroke methanol engine lubricating oil according to claim 1, characterized in that, The antifoaming agent mentioned includes silicone-based antifoaming agents.

7. The method for preparing the lubricating oil for marine four-stroke methanol engines according to any one of claims 1-6, characterized in that, Includes the following steps: Mineral oil is added to a mixing tank; then salicylate, sulfide alkylphenol salt, succinimide, zinc dioctyl dithiophosphate, zinc butyl octyl dithiophosphate, and amine antioxidant are added to the mixing tank for the first mixing; then an antifoaming agent is added for the second mixing to obtain the final product.

8. The preparation method according to claim 7, characterized in that, The initial mixing process parameters are: mixing and stirring at a temperature of 65±5℃ for 1-2 hours.

9. The preparation method according to claim 7, characterized in that, The second mixing process parameters are: mixing and stirring at a temperature of 65±5℃ for 2-4 hours.

10. The application of the marine four-stroke methanol engine lubricating oil according to any one of claims 1-6 in a marine four-stroke methanol engine.

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