Lubricating oil additives, lubricating oils, and methods of making and using the same

Abstract

The application provides a lubricating oil additive, a lubricating oil and a preparation method and application thereof, and the lubricating oil additive comprises a methyl silicon type antifoaming agent, kerosene and a polyhydric alcohol ester, the weight ratio of the methyl silicon type antifoaming agent and the kerosene is 1:5-15, and the weight ratio of the polyhydric alcohol ester to the total weight of the methyl silicon type antifoaming agent and the kerosene is 99-80:1.The methyl silicon type antifoaming agent, the kerosene and the polyhydric alcohol ester are synergistically matched in a specific proportion as the additive of the lubricating oil, so that the antifoaming property of the lubricating oil is improved, meanwhile, the quality of the lubricating oil is stable, appearance turbidity does not occur, and the lubricating oil does not settle after long-time storage, and the storage stability of the oil product is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lubricating oil, in particular to a lubricating oil additive, a lubricating oil and a preparation method and application thereof. BACKGROUND

[0002] The increasingly stringent emission regulations promote the continuous improvement of engine aftertreatment technology. In order to meet the lubrication requirements of new engines, diesel engine oil is also constantly updated and replaced, such as from the earliest CC grade, CD grade diesel engine oil to the highest CJ-4 grade diesel engine oil today. With the upgrading of specifications, higher requirements are put forward for the foam properties of diesel engine oil, such as the high temperature (93.5℃) foam properties of diesel engine oil are improved from 150mL / 0mL of CC grade to 20mL / 0mL of CJ-4 grade. The foam properties of diesel engine oil have a great influence on the use performance of diesel engine oil.

[0003] During the use of diesel engine oil, air is mixed into the diesel engine oil due to various factors such as oscillation and stirring to produce foam. Under normal circumstances, diesel engine oil itself has good defoaming effect, and the foam will automatically break and disappear. However, due to long-term storage of diesel engine oil, the foam properties of the oil product will deteriorate, and a large amount of foam will be generated during use, which will bring many adverse effects to the use performance of diesel engine oil, such as causing poor lubrication of diesel engine parts, and even possibly causing air blockage to interrupt oil supply of the oil pump, resulting in increased wear of diesel engine parts.

[0004] To solve the problem of foam generated in the use of diesel engine oil, an anti-foaming agent is usually added in the lubricating oil in the prior art. At present, the anti-foaming agents on the market are mostly silicon type, non-silicon type and composite type. The anti-foaming effect of the silicon type anti-foaming agent is good, but its oil solubility is relatively poor, and it has a great influence on the air release value of the oil. At the same time, when the addition amount of the silicon type anti-foaming agent reaches a certain degree, the oil appears turbidity, the anti-foaming performance decreases, and the storage stability of the oil becomes poor. The non-silicon type anti-foaming agent can change the molecular attraction between the film layers, reduce the strength and toughness of the film, and make the foam stability decrease, and the diameter of the generated bubbles is large, which can be easily released, and has good air release property. However, the anti-foaming effect is relatively poor. The composite anti-foaming agent is developed by balancing and optimizing the performance characteristics of the silicon type and non-silicon type anti-foaming agents, such as anti-foaming property, air release property, applicable medium environment and the like. However, when the addition amount increases to a certain degree, the appearance of the oil begins to appear turbidity, which affects the oil properties, and the time is long enough to cause the precipitation phenomenon, resulting in poor oil stability. For example, patent No. CN104232246A discloses a composite anti-foaming agent for lubricating oil, which is composed of 80-99% solvent and 1-20% anti-foaming agent. The anti-foaming agent is composed of 1-5 parts of silicon oil type anti-foaming agent, 1-5 parts of fluorine-containing silicon oil type anti-foaming agent and 3-8 parts of acrylic ester copolymer by weight. When applied to lubricating oil, the addition amount of the lubricating oil composite anti-foaming agent is 0.005-0.01%. The anti-foaming agent can be used to improve the high temperature anti-foaming performance of the oil. However, the disadvantage is that the storage time of the lubricating oil is too long, the oil appears turbidity, which affects the oil properties, causes poor oil stability, and further makes the defoaming property of the lubricating oil poor.

[0005] In summary, the lubricating oil in the prior art has the problems of poor anti-foaming property, poor oil stability or high cost. Therefore, it is necessary to provide a new lubricating oil additive which can effectively improve the above problems. SUMMARY

[0006] The main purpose of the present application is to provide a lubricating oil additive, a lubricating oil and a preparation method and application thereof, so as to solve the problems of poor anti-foaming property, poor oil stability or high cost of the lubricating oil in the prior art.

[0007] In order to achieve the above purpose, according to one aspect of the present application, a lubricating oil additive is provided, which comprises a methyl silicon type anti-foaming agent, kerosene and a polyol ester. The weight ratio of the methyl silicon type anti-foaming agent to the kerosene is 1:5-15, and the weight ratio of the polyol ester to the total weight of the methyl silicon type anti-foaming agent and the kerosene is 99-80:1.

[0008] Further, in the lubricating oil additive, the weight ratio of the methyl silicon type anti-foaming agent to the kerosene is 1:8-10.

[0009] Further, the weight ratio of the weight of the polyol ester to the total weight of the methyl silicone antifoam agent and the kerosene is 99-95:1.

[0010] Further, the polyol ester is selected from one or more of the group consisting of Prilube 3970, Mobil NP343, Mobil NP451, Mobil A32, and Mobil A51.

[0011] Further, the polyol ester is Prilube 3970.

[0012] Further, the methyl silicone antifoam agent is one or more of T901, T902, T903, or 2# compound antifoam agent.

[0013] Further, the methyl silicone antifoam agent is T901.

[0014] According to another aspect of the present application, there is provided a lubricating oil, comprising a finished oil and a lubricating oil additive, the lubricating oil additive being the aforementioned lubricating oil additive.

[0015] Further, the finished oil comprises synthetic base oil PAO40, coal-based base oil CTL10, and coal-based base oil CTL8.

[0016] Further, the amount of the lubricating oil additive is 0.5-3wt% of the weight of the finished oil.

[0017] According to another aspect of the present application, there is provided a method for preparing a lubricating oil, comprising: mixing a methyl silicone antifoam agent, kerosene, and a polyol ester to obtain a lubricating oil additive; and mixing the lubricating oil additive and a finished oil to obtain the lubricating oil.

[0018] Further, the method for preparing a lubricating oil further comprises the following steps: step S1, first mixing the methyl silicone antifoam agent and the kerosene to form a mixed solution; step S2, second mixing the mixed solution and the polyol ester to form the lubricating oil additive; and step S3, third mixing the lubricating oil additive and the finished oil to obtain the lubricating oil.

[0019] Further, in step S1, the first mixing is performed at a temperature of 20-25℃; in step S2, the second mixing is performed at a temperature of 40-50℃; and in step S3, the third mixing is performed at a temperature of 40-70℃.

[0020] Further, before step S1, the method for preparing a lubricating oil further comprises a step of grinding the methyl silicone antifoam agent. Further preferably, the grinding is performed for 20-30min.

[0021] Further, in step S2, the mixed solution and the polyol ester are stirred at a stirring speed of 500-800 rpm for 5-10 min, and then the mixed solution and the polyol ester are ultrasonically treated for 5-10 min. Further preferably, the power of the ultrasonic treatment is 80-500 W.

[0022] Further, in step S3, the lubricating oil additive is added to the finished oil in the form of spraying to obtain the lubricating oil.

[0023] Further, the flow rate of the spraying is 5-20 mg / L.

[0024] According to another aspect of the present application, there is provided a use of the lubricating oil in a diesel engine.

[0025] According to the technical solution of the present application, the polyol ester is first selected and added as a dissolving carrier. The polyol ester has a high polarity and a strong affinity to the methyl silicon type antifoam agent and kerosene in the lubricating oil additive. The polyol ester has a small surface tension and can easily dissolve a small amount of the methyl silicon type antifoam agent. The polyol ester in which the methyl silicon type antifoam agent is dissolved has a strong binding force with kerosene, thereby forming a stable system of the methyl silicon type antifoam agent, the polyol ester and kerosene. The addition of the polyol ester improves the solubility and stability of the methyl silicon type antifoam agent in kerosene, so that the methyl silicon type antifoam agent can be uniformly and stably dissolved in the lubricating oil system, thereby greatly exerting the antifoam performance of the methyl silicon type antifoam agent. The product oil has excellent foam suppressing performance (for dispersing bubbles, the silicon type antifoam agent reduces the surface tension, thereby reducing the diameter of the bubbles, so that the bubbles are relatively difficult to rise, thereby suppressing the release of air) and defoaming performance (reducing the surface tension of the foam to achieve the effect of defoaming), and the oil product has better storage stability. DETAILED DESCRIPTION

[0026] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments.

[0027] As described in the background section, the lubricating oil in the prior art cannot simultaneously meet the lower cost, the better antifoam performance and the stable oil product. In order to solve this problem, the present application provides a lubricating oil additive, which comprises a methyl silicon type antifoam agent, kerosene and a polyol ester. The weight ratio of the methyl silicon type antifoam agent to the kerosene is 1:5-15, and the weight ratio of the polyol ester to the total weight of the methyl silicon type antifoam agent and the kerosene is 99-80:1.

[0028] The application adopts the methyl silicon type antifoaming agent, kerosene and polyhydric alcohol ester compounded lubricating oil additive, the methyl silicon type antifoaming agent, kerosene and polyhydric alcohol ester are synergistically matched, so that the antifoaming property of the lubricating oil and the stability of the oil product can be further significantly improved on the basis of meeting lower production cost, and the lubricating oil has good foam property when applied as diesel engine oil, and does not cause the interruption of oil supply of the diesel engine oil pump, the increase of wear of diesel engine parts and other adverse effects.

[0029] The lubricating oil additive of the application includes the kerosene component, the cost of which is low and the cost performance is high. In this way, the lubricating oil with excellent application performance can be obtained at low cost. Meanwhile, the methyl silicon type antifoaming agent component is adopted in the application, which has excellent antifoaming effect, good thermal stability, chemical inertness and oxidation resistance, and is not prone to react with other substances in the lubricating oil, and also has good viscosity-temperature performance.

[0030] However, the applicant further found that when the above-mentioned two components are used, the methyl silicon type antifoaming agent cannot be uniformly dispersed in the kerosene, which makes it not fully release the antifoaming property, on the one hand, and on the other hand, as the amount of the methyl silicon type antifoaming agent increases, the turbidity of the product oil is particularly obvious. This is because the organic silicon type antifoaming agent is not dissolved in the oil product, but dispersed in the oil product. When the amount of the antifoaming agent is large, the small particles of the antifoaming agent are aggregated into droplets, which causes the appearance of the oil product to be turbid. At the same time, due to the large aggregation of the droplets, the surface tension system of the oil product is destroyed, which also leads to the decrease of the antifoaming property of the oil product. After long storage, sedimentation phenomenon occurs, which leads to the poor storage stability of the oil product, and further brings many adverse effects to the use performance of the diesel engine oil, such as causing poor lubrication of the diesel engine parts, and even possibly causing air blockage to interrupt the oil supply of the oil pump, which causes the increase of wear of the diesel engine parts.

[0031] Based on this, the application first proposes to select and join polyol ester as a dissolving carrier. The polarity of polyol ester is relatively high, and the affinity with the methyl silicon type antifoam in the lubricating oil additive and kerosene is relatively strong. The surface tension of polyol ester is small, and the methyl silicon type antifoam can be easily dissolved in polyol ester. The polyol ester in which the methyl silicon type antifoam is dissolved has strong binding force with kerosene, thereby forming a stable system of the methyl silicon type antifoam, polyol ester and kerosene. The addition of polyol ester improves the solubility and stability of the methyl silicon type antifoam in kerosene, so that the methyl silicon type antifoam can be uniformly and stably dissolved in the lubricating oil system, thereby more greatly exerting the antifoam performance of the methyl silicon type antifoam, so that the product oil has excellent foam inhibition performance (for dispersed bubbles, the silicon type antifoam reduces the surface tension, thereby making the diameter of the bubbles small, so that the bubbles are relatively difficult to rise, thereby inhibiting the release of air) and defoaming performance (reducing the surface tension of the foam to achieve the effect of defoaming), and the oil product has better storage stability.

[0032] In order to balance the stability, antifoam property and application performance of the lubricating oil, on the one hand, the weight ratio of the methyl silicon type antifoam and kerosene is limited to 1:5-15 (for example, it can be 1:5, 1:8, 1:10, 1:12, 1:14, 1:15). Controlling the weight ratio of the methyl silicon type antifoam and kerosene in the above range can make the methyl silicon type antifoam well dispersed in kerosene, so that the methyl silicon type antifoam can exert better antifoam performance. On the other hand, the weight ratio of the polyol ester to the total weight of the methyl silicon type antifoam and kerosene is limited to 99-80:1 (for example, it can be 99:1, 95:1, 92:1, 90:1, 88:1, 85:1, 82:1, 80:1). When the amount of polyol ester is too high, the concentration of the methyl silicon type antifoam in the lubricating oil is reduced, which affects the antifoam effect of the lubricating oil. If the amount of polyol ester is too low, the methyl silicon type antifoam cannot be well dissolved in the lubricating oil, which leads to poor stability of the oil product and affects the properties of the oil product.

[0033] In summary, the methyl silicon type antifoam, kerosene and polyol ester are synergistically combined in a specific ratio as an additive of the lubricating oil, which not only improves the antifoam property of the lubricating oil, but also stabilizes the quality of the lubricating oil, so that the appearance is not turbid, and the oil product does not settle after long-term storage, thereby improving the storage stability of the oil product.

[0034] To further balance the stability, anti-foaming property and application performance of the lubricating oil, the weight ratio of the methyl silicone type anti-foaming agent and the kerosene is preferably 1:8-10. When the amount of the kerosene is too high, the concentration of the methyl silicone type anti-foaming agent in the lubricating oil is reduced, the anti-foaming effect of the lubricating oil is affected, and the flash point of the lubricating oil is also reduced, thereby affecting the safety of the lubricating oil. When the amount of the kerosene is lower than the range, the dissolving effect of the methyl silicone type anti-foaming agent in the lubricating oil additive is reduced, thereby affecting the anti-foaming property and stability of the lubricating oil.

[0035] To further balance the stability, anti-foaming property and application performance of the lubricating oil, the weight ratio of the polyol ester to the total weight of the methyl silicone type anti-foaming agent and the kerosene is preferably 99-95:1.

[0036] To further improve the anti-foaming property and oil stability of the lubricating oil, the polyol ester is preferably selected from one or more of the following: Priolube 3970 (purchased from HOD Chemicals (Shanghai) Co., Ltd.), NP343 (purchased from ExxonMobil Corporation), NP451, A32 (purchased from ExxonMobil Corporation) or A51 (purchased from ExxonMobil Corporation). Further preferably, the polyol ester is Priolube 3970.

[0037] To further improve the anti-foaming property of the lubricating oil, the methyl silicone type anti-foaming agent is preferably one or more of the following: T901 (purchased from Jinzhou Xinxing Petroleum Additives Co., Ltd.), T902 (purchased from Jinzhou Xinxing Petroleum Additives Co., Ltd.), T903 (purchased from Jinzhou Xinxing Petroleum Additives Co., Ltd.) or 2# compound defoaming agent (purchased from Jinzhou Xinxing Petroleum Additives Co., Ltd.). More preferably, the methyl silicone type anti-foaming agent is T901.

[0038] The application also provides a lubricating oil, which comprises a finished oil and a lubricating oil additive, and the lubricating oil additive is the lubricating oil additive described above.

[0039] Based on the above reasons, the lubricating oil of the application not only can improve the anti-foaming property of the lubricating oil, but also can stabilize the quality of the lubricating oil, and the appearance of the lubricating oil is not turbid, and the lubricating oil will not be precipitated after long-term storage, and the storage stability of the lubricating oil is improved.

[0040] In consideration of the application of the lubricating oil described above in the field of subsequent diesel engine oil engines, the finished oil preferably comprises synthetic base oil PAO40, coal-based base oil CTL10 and coal-based base oil CTL8. Further preferably, the finished oil comprises 5-10wt% of synthetic base oil PAO40, 65-85wt% of coal-based base oil CTL10 and 5-15wt% of coal-based base oil CTL8.

[0041] In a preferred embodiment, the amount of the lubricating oil additive is 0.5-3 wt% of the weight of the finished oil. The present application controls the amount of the lubricating oil additive in the range of 0.5-3 wt%, which can fully exert the performance of inhibiting foam and defoaming on the basis of meeting the conventional performance requirements of the lubricating oil, so that the stability of the oil product is better. If it is too high, the cost is higher, and the stability is also decreased.

[0042] The present application also provides a preparation method of the above lubricating oil, which comprises: mixing the methyl silicon type antifoam agent, kerosene and polyol ester to obtain a lubricating oil additive, and mixing the lubricating oil additive and the finished oil to obtain the lubricating oil.

[0043] Based on the above reasons, the present application creatively uses the lubricating oil additive compounded by the methyl silicon type antifoam agent, kerosene and polyol ester on the basis of the conventional lubricating oil formula, and the three components are synergistically combined, so that the anti-foaming performance of the lubricating oil and the stability of the oil product can be further significantly improved.

[0044] Preferably, the preparation method comprises the following steps: step S1, mixing the methyl silicon type antifoam agent and kerosene to form a mixed solution; step S2, secondly mixing the mixed solution and the polyol ester to form a lubricating oil additive; and step S3, adding the lubricating oil additive to the finished oil to obtain the lubricating oil. The polyol ester is added to the system after the methyl silicon type antifoam agent and kerosene are mixed, so that the solubility of the kerosene and the methyl silicon type antifoam agent is better, and the performance of the kerosene and the methyl silicon type antifoam agent can be exerted to a greater extent, and then the obtained lubricating oil has better foam inhibiting and defoaming capacity, and the performance stability of the oil product is better.

[0045] In a preferred embodiment, before step S1, the preparation method further comprises a step of grinding the methyl silicon type antifoam agent; and the grinding time is 20-30 min. Grinding the methyl silicon type antifoam agent can make the solubility of the methyl silicon type antifoam agent in the lubricating oil system better, and then the performance uniformity of the product oil is better.

[0046] In order to further improve the solubility and stability of the methyl silicon type antifoam agent in the lubricating oil system, in step S1, the first mixing temperature is 20-25℃.

[0047] In a preferred embodiment, in step S2, the second mixing temperature is 40-50℃, and the polyol ester is mixed with the mixed solution under heating, which can better combine the methyl silicon type antifoam agent with the polyol ester, and the polyol ester as a dissolving carrier can make the methyl silicon type antifoam agent dissolve in the lubricating oil system more quickly and uniformly.

[0048] In a preferred embodiment, in step S2, the mixture and the polyol ester are stirred at a stirring rate of 500-800 rpm for 5-10 min, and then the mixture and the polyol ester are ultrasonically treated for 5-10 min; further preferably, the ultrasonic power is 80-500 W; during the above steps, controlling the stirring rate and the stirring time within the above ranges can further improve the solubility and stability of the methyl silicon type antifoam agent in the lubricating oil system. Controlling the ultrasonic time and the ultrasonic power of the mixture and the polyol ester can further improve the performance uniformity of the lubricating oil additive.

[0049] In a preferred embodiment, in step S3, the lubricating oil additive is added to the finished oil in a spraying manner to obtain the lubricating oil. The spraying manner can more uniformly add the lubricating oil additive to the finished oil, thereby improving the uniformity of the oil product. Further preferably, the flow rate of the spraying is 5-20 mg / L.

[0050] The application also provides the above lubricating oil for use in a diesel engine. The lubricating oil of the application has good foam properties when used as diesel engine oil, and does not cause the diesel engine oil pump to interrupt oil supply, increase the wear of diesel engine parts, and other adverse effects.

[0051] The application will be further described in detail below in combination with specific examples, which cannot be understood as limiting the scope of the application.

[0052] Example 1

[0053] T901 (Jinzhou Xinxing Petroleum Additives Co., Ltd.) was ground for 30 min;

[0054] The ground T901 was mixed with kerosene (purchased from Jiage New Material Technology Co., Ltd.) at room temperature (25°C), and the weight ratio of T901 to kerosene was 1:9 to form a mixture;

[0055] The above mixture was mixed with Weida Priolube 3970 (purchased from Weida Chemical (Shanghai) Co., Ltd.) at 50°C (the weight ratio of Weida Priolube 3970 to the mixture was 99:1), and then stirred at a stirring rate of 700 rpm for 5 min, and then ultrasonically treated for 10 min at a power of 300 W to form a lubricating oil additive;

[0056] The lubricant additive was mixed with a finished oil at 65°C by spraying to form a lubricant. The finished oil consisted of 10 wt% of the synthetic base oil PAO40 (purchased from ExxonMobil), 70 wt% of the coal-based base oil CTL10 (purchased from Lu'an Chemical Group Co., Ltd.), and 20 wt% of the coal-based base oil CTL8 (purchased from Lu'an Chemical Group Co., Ltd.). The spray flow rate was 5 mg / L, and the amount of the lubricant additive was 3 wt% of the weight of the finished oil.

[0057] Example 2

[0058] The only difference from Example 1 is that the weight ratio of T901 to kerosene is 1:5.

[0059] Example 3

[0060] The only difference from Example 1 is that the weight ratio of T901 to kerosene is 1:15.

[0061] Example 4

[0062] The only difference from Example 1 is that the weight ratio of Croda Priolube 3970 to the sum of T901 and kerosene is 95:1.

[0063] Example 5

[0064] The only difference from Example 1 is that the weight ratio of Croda Priolube 3970 to the sum of T901 and kerosene is 80:1.

[0065] Example 6

[0066] The only difference from Example 1 is that the amount of the lubricating oil additive is 0.5 wt % of the weight of the finished oil.

[0067] Example 7

[0068] The only difference from Example 1 is that the ground T901, kerosene and Croda Priolube 3970 are mixed at room temperature (25° C.) to form a lubricating oil additive;

[0069] The lubricating oil additive was mixed with finished oil (composed of 10 wt% synthetic base oil PAO40, 70 wt% coal-based base oil CTL10, and 20 wt% coal-based base oil CTL8) at 65° C. by spraying to form lubricating oil.

[0070] Example 8

[0071] The only difference from Example 1 is that Croda Priolube 3970 is replaced by Mobil NP451 (purchased from ExxonMobil).

[0072] Comparative Example 1

[0073] The difference from Example 1 is only that no Prista Priolube 3970 is added.

[0074] Comparative Example 2

[0075] The difference from Example 1 is only that T901 is replaced by T912 (purchased from Jinzhou Shengda Chemical Co., Ltd., a non-silicon type antifoaming agent, the main component of which is polyacrylate).

[0076] Comparative Example 3

[0077] The difference from Example 1 is only that the weight ratio of T901 to kerosene is 1:2.

[0078] Comparative Example 4

[0079] The difference from Example 1 is only that the weight ratio of T901 to kerosene is 1:20.

[0080] Comparative Example 5

[0081] The difference from Example 1 is only that the weight ratio of Prista Priolube 3970 to the sum of T901 and kerosene is 70:1.

[0082] Comparative Example 6

[0083] The difference from Example 1 is only that the weight ratio of Prista Priolube 3970 to the sum of T901 and kerosene is 110:1.

[0084] Performance characterization:

[0085] The above examples and comparative examples are tested for antifoaming property and oil stability, and the test results are shown in Table 1.

[0086] Test method:

[0087] Foam property: GB / T 12579

[0088] Appearance: 100 ml of the lubricating oil prepared in the above examples and comparative examples is taken into a clean measuring cylinder, and the quality of the oil product is observed to see if turbidity or flocculent matter appears. If it is uniform and transparent, without turbidity and flocculent matter, it indicates that the oil product is stable.

[0089] Table 1

[0090] Foam properties (93.5°C, mL / mL) Appearance Example 1 0 / 0 Transparent, no floe Example 2 30 / 0 Transparent, no floe Example 3 60 / 0 Transparent, no floe Example 4 60 / 0 Transparent, no floe Example 5 30 / 0 Slightly hazy Example 6 40 / 0 Slightly hazy Example 7 60 / 0 Slightly hazy Example 8 30 / 0 Transparent, no floe Comparative Example 1 180 / 0 Hazy Comparative Example 2 80 / 0 Transparent, no floe Comparative Example 3 50 / 0 Slightly hazy Comparative Example 4 80 / 0 Transparent, no floe Comparative Example 5 80 / 0 Slightly hazy Comparative Example 6 60 / 1 Transparent, no floe

[0091] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A lubricating oil additive, characterized in that: The invention is composed of the following ingredients: a methyl silicone antifoaming agent, kerosene and a polyol ester, wherein the weight ratio of the methyl silicone antifoaming agent to the kerosene is 1:5-15, and the weight ratio of the polyol ester to the total weight of the methyl silicone antifoaming agent and the kerosene is 99-80:1; the polyol ester is selected from one or more of Croda Priolube 3970, Mobil NP343 and Mobil NP451; the methyl silicone antifoaming agent is T901; The preparation method of the lubricating oil additive comprises the following steps: Step S1, first mixing the methyl silicone antifoaming agent and the kerosene to form a mixed liquid; Step S2, mixing the mixed liquid and the polyol ester for a second time to form the lubricating oil additive; In the step S1, the temperature of the first mixing is 20-25°C; in the step S2, the temperature of the second mixing is 40-50°C.

2. The lubricating oil additive according to claim 1, characterized in that In the lubricating oil additive, the weight ratio of the methyl silicone antifoaming agent to the kerosene is 1:8-10; the weight ratio of the polyol ester to the total weight of the methyl silicone antifoaming agent and the kerosene is 99-95:

1.

3. The lubricating oil additive according to claim 1 or 2, characterized in that The polyol ester is Croda Priolube 3970.

4. A lubricating oil comprising a finished oil and a lubricating oil additive, characterized in that: The lubricating oil additive is the lubricating oil additive according to any one of claims 1 to 3.

5. The lubricating oil according to claim 4, characterized in that The finished oil includes synthetic base oil PAO40, coal-based base oil CTL10 and coal-based base oil CTL8.

6. The lubricating oil according to claim 5, characterized in that The amount of the lubricating oil additive is 0.5-3 wt % of the weight of the finished oil.

7. A method for preparing the lubricating oil according to claim 4, characterized in that: The preparation method of the lubricating oil comprises: Step S1, first mixing the methyl silicone antifoaming agent and the kerosene to form a mixed liquid; Step S2, mixing the mixed liquid and the polyol ester for a second time to form a lubricating oil additive; Step S3: mixing the lubricating oil additive and the finished oil for a third time to obtain the lubricating oil.

8. The method for preparing lubricating oil according to claim 7, characterized in that: In the step S1, the temperature of the first mixing is 20-25°C; in the step S2, the temperature of the second mixing is 40-50°C; and in the step S3, the temperature of the third mixing is 40-70°C.

9. The method for preparing lubricating oil according to claim 8, characterized in that: Prior to step S1, the preparation method further includes a step of grinding the methyl silicone antifoaming agent; the grinding time is 20 to 30 minutes; in step S2, the mixed liquid and the polyol ester are first stirred at a stirring rate of 500 to 800 rpm for 5 to 10 minutes, and then the mixed liquid and the polyol ester are ultrasonically treated for 5 to 10 minutes; the power of the ultrasonication is 80 W to 500 W; in step S3, the lubricating oil additive is added to the finished oil by spraying to obtain the lubricating oil; the flow rate of the spray is 5 to 20 mg / L.

10. Use of the lubricating oil according to any one of claims 4 to 6 in a diesel engine.