A thermally conductive and wear-resistant lubricating oil and its preparation method

Abstract

This invention discloses a thermally conductive and wear-resistant lubricating oil and its preparation method. The specific preparation method is as follows: Silicon carbide and boron nitride powders are ball-milled at a mass ratio of 1:(0.5-2) using methanol as the ball milling medium to obtain a ball milling fluid. Then, kojic acid and silane coupling agent are added to the ball milling fluid at a mass ratio of 1:(3-10), with the total mass of kojic acid and silane coupling agent being 2-10% of the ball milling fluid. The fluid is then sheared and emulsified in a high-speed shear mill. The sheared emulsion is centrifuged to obtain a precipitate. The precipitate is added to deionized water and then boiled until crystallization occurs. The precipitate is ground and passed through a 1000-3000 mesh sieve. The base oil is heated to 70-90 degrees Celsius, and then detergent, antioxidant, dispersant, passivator, rust inhibitor, and the sieved precipitate are added according to the mass proportions. The mixture is stirred and mixed to obtain the thermally conductive lubricating oil. This invention achieves a significant improvement in the thermal conductivity of lubricating oil by uniformly dispersing functionalized silicon carbide and boron nitride in the lubricating oil, thereby effectively dissipating heat and maintaining the stable operation of mechanical equipment in high-temperature environments.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil technology, specifically to a thermally conductive and wear-resistant lubricating oil and its preparation method. Background Technology

[0002] Lubricating oil plays a crucial role in the operation of mechanical equipment, its main functions being to reduce friction, wear, and heat dissipation. However, traditional lubricating oils often perform unsatisfactorily in high-temperature, high-load environments, primarily due to their insufficient thermal conductivity and wear resistance. With the ever-increasing demands for equipment performance and reliability in modern industry, the development of lubricating oils with high thermal conductivity and high wear resistance has become a research hotspot.

[0003] Silicon carbide (SiC) and boron nitride (BN) are two materials that excel in thermal conductivity and wear resistance. Silicon carbide possesses high hardness, high thermal conductivity, and good chemical stability, making it widely used in high-temperature and wear-resistant materials. Boron nitride, especially hexagonal boron nitride (h-BN), is renowned for its high thermal conductivity and lubricity, earning it the nickname "white graphite." However, directly adding silicon carbide and boron nitride powders to lubricating oils presents several problems:

[0004] Poor dispersibility: Silicon carbide and boron nitride powders tend to agglomerate in the oil phase, making it difficult to disperse evenly and affecting the performance of the lubricating oil.

[0005] Insufficient stability: Untreated powders have poor stability in lubricating oil and are prone to settling, resulting in unstable lubricating oil performance.

[0006] Lubrication performance is affected: Directly adding powder may change the viscosity and fluidity of the lubricating oil, affecting its original lubrication performance. Summary of the Invention

[0007] To address the above problems, this invention provides a thermally conductive and wear-resistant lubricating oil and its preparation method.

[0008] In its first aspect, this invention provides a method for preparing a thermally conductive and wear-resistant lubricating oil, which uses kojic acid to functionalize silicon carbide and boron nitride, thereby improving its thermal conductivity and wear resistance without affecting the lubrication effect. The components, by mass parts, are as follows:

[0009] The ingredients are: 85-95 parts base oil, 0.5-2 parts detergent, 0.1-1 part antioxidant, 0.5-2 parts dispersant, 0.2-0.9 parts passivator, 0.2-1 part rust inhibitor, and 1-3 parts functionalized silicon carbide and boron nitride mixed powder. The specific preparation method is as follows:

[0010] Step 1: Mix silicon carbide and boron nitride powders by ball milling at a mass ratio of 1:(0.5-2) with methanol as the ball milling medium to obtain a ball milling slurry. Then, add kojic acid and silane coupling agent to the ball milling slurry at a mass ratio of 1:(3-10), with the total mass of kojic acid and silane coupling agent being 2-10% of the ball milling slurry. Then, shear emulsify the mixture in a high-speed shear mill.

[0011] Step 2: Centrifuge the sheared emulsion to obtain a precipitate. Add deionized water to the precipitate and boil until crystallization occurs. Grind the precipitate and pass it through a 1000-3000 mesh sieve.

[0012] Step 3: Heat the base oil to 70-90 degrees Celsius, then add detergent, antioxidant, dispersant, passivator, rust inhibitor and sieved precipitate according to the mass fraction, and stir to obtain heat-conducting lubricating oil.

[0013] Preferably, in step one, the silane coupling agent is one or more of KH550, KH560, and KH570, the ball milling rate is 200-800 rpm, and the total high-speed shearing time is 8-12 h, wherein the shearing is paused for 5 min after every 30-60 min of shearing.

[0014] Preferably, in step two, the centrifugation rate is 3500–7200 rcf, the centrifugation time is 30–90 min, and the mass of deionized water added is 50–100 times that of the precipitate.

[0015] Preferably, in step three, the stirring rate is 200-600 rpm and the stirring time is 0.5-4 h.

[0016] The present invention provides, in a second aspect, a thermally conductive and wear-resistant lubricating oil prepared by the preparation method of the first aspect of the present invention.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. The present invention achieves a significant improvement in the thermal conductivity of lubricating oil by uniformly dispersing functionalized silicon carbide and boron nitride in the lubricating oil, thereby effectively dissipating heat and maintaining the stable operation of mechanical equipment in high-temperature environments.

[0019] 2. The high hardness of silicon carbide and boron nitride in this invention endows the lubricating oil with excellent wear resistance, effectively reducing wear between mechanical parts and extending the service life of the equipment.

[0020] 3. The functionalization process in this invention ensures the uniform dispersion of silicon carbide and boron nitride powders in the lubricating oil, without affecting the viscosity and fluidity of the lubricating oil, thus maintaining the good lubrication effect of the lubricating oil. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a comparison diagram of the thermal conductivity of the lubricating oils prepared in the embodiments and comparative examples of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1:

[0025] A thermally conductive and wear-resistant lubricating oil and its preparation method, wherein the components are as follows by mass parts:

[0026] Base oil: 90 parts, detergent: 1.5 parts, antioxidant: 0.5 parts, dispersant: 1.5 parts, passivator: 0.5 parts, rust inhibitor: 0.5 parts, functionalized silicon carbide and boron nitride mixed powder: 2 parts

[0027] The preparation method is as follows:

[0028] Silicon carbide and boron nitride powders were ball-milled at a mass ratio of 1:1 using methanol as the milling medium to obtain a ball milling slurry. Kojic acid and silane coupling agent KH550 were added at a mass ratio of 1:5, with the total mass being 5% of the ball milling slurry. The mixture was then sheared at 600 rpm for 10 hours in a high-speed shear mill, with a 5-minute pause after every 30 minutes of shearing.

[0029] The sheared emulsion was centrifuged at 5000 rcf for 60 minutes to obtain a precipitate. Deionized water was added to the precipitate in an amount 75 times its mass, and the mixture was boiled until crystallization occurred. The precipitate was then ground and passed through a 2000-mesh sieve.

[0030] Heat the base oil to 80 degrees Celsius, then add detergent, antioxidant, dispersant, passivator, rust inhibitor and sieved precipitate according to the mass fraction. Stir at 400 rpm for 2 hours to obtain the heat-conducting lubricating oil.

[0031] Example 2:

[0032] A thermally conductive and wear-resistant lubricating oil and its preparation method, wherein the components are as follows by mass parts:

[0033] Base oil: 85 parts, detergent: 1 part, antioxidant: 0.8 parts, dispersant: 1.2 parts, passivator: 0.7 parts, rust inhibitor: 0.8 parts, functionalized silicon carbide and boron nitride mixed powder: 1.5 parts

[0034] The preparation method is as follows:

[0035] Silicon carbide and boron nitride powders were ball-milled at a mass ratio of 1:1.5 using methanol as the milling medium to obtain a ball milling slurry. Kojic acid and silane coupling agent KH560 were added at a mass ratio of 1:7, with the total mass being 8% of the ball milling slurry. The mixture was then sheared at 500 rpm for 8 hours in a high-speed shear mill, with a 5-minute pause after every 45 minutes of shearing.

[0036] The sheared emulsion was centrifuged at 6000 rcf for 45 minutes to obtain a precipitate. Deionized water (60 times its mass) was added to the precipitate, and the mixture was boiled until crystallization occurred. The precipitate was then ground and passed through a 1500-mesh sieve.

[0037] Heat the base oil to 75 degrees Celsius, then add detergent, antioxidant, dispersant, passivator, rust inhibitor and sieved precipitate according to the mass fraction. Stir at 300 rpm for 1 hour to obtain the heat-conducting lubricating oil.

[0038] Example 3:

[0039] A thermally conductive and wear-resistant lubricating oil and its preparation method, wherein the components are as follows by mass parts:

[0040] Base oil: 95 parts, detergent: 0.5 parts, antioxidant: 0.2 parts, dispersant: 0.8 parts, passivator: 0.3 parts, rust inhibitor: 0.3 parts, functionalized silicon carbide and boron nitride mixed powder: 3 parts

[0041] The preparation method is as follows:

[0042] Silicon carbide and boron nitride powders were ball-milled at a mass ratio of 1:2 using methanol as the milling medium to obtain a ball milling slurry. Kojic acid and silane coupling agent KH570 were added at a mass ratio of 1:3, with the total mass being 10% of the ball milling slurry. The mixture was then sheared at 400 rpm for 12 hours in a high-speed shear mill, with a 5-minute pause after every 60 minutes of shearing.

[0043] The sheared emulsion was centrifuged at 7200 rcf for 90 minutes to obtain a precipitate. Deionized water (100 times its mass) was added to the precipitate, and the mixture was boiled until crystallization occurred. The precipitate was then ground and passed through a 3000-mesh sieve.

[0044] Heat the base oil to 90 degrees Celsius, then add detergent, antioxidant, dispersant, passivator, rust inhibitor and sieved precipitate according to the mass fraction. Stir at 600 rpm for 4 hours to obtain the heat-conducting lubricating oil.

[0045] Comparative example:

[0046] A thermally conductive and wear-resistant lubricating oil and its preparation method, wherein the components are as follows by mass parts:

[0047] Base oil: 90 parts, detergent: 1.5 parts, antioxidant: 0.5 parts, dispersant: 1.5 parts, passivator: 0.5 parts, rust inhibitor: 0.5 parts, unfunctionalized silicon carbide and boron nitride mixed powder: 2 parts

[0048] The preparation method is as follows:

[0049] Silicon carbide and boron nitride powders were ball-milled at a mass ratio of 1:1 using methanol as the milling medium to obtain a ball milling slurry. A silane coupling agent, KH550, was added, with a total mass of 5% of the ball milling slurry. The mixture was then sheared at 600 rpm for 10 hours in a high-speed shear mill, with a 5-minute pause after every 30 minutes of shearing.

[0050] The sheared emulsion was centrifuged at 5000 rcf for 60 minutes to obtain a precipitate. Deionized water was added to the precipitate in an amount 75 times its mass, and the mixture was boiled until crystallization occurred. The precipitate was then ground and passed through a 2000-mesh sieve.

[0051] Heat the base oil to 80 degrees Celsius, then add detergent, antioxidant, dispersant, passivator, rust inhibitor and sieved precipitate according to the mass fraction. Stir at 400 rpm for 2 hours to obtain the heat-conducting lubricating oil.

Claims

1. A method for preparing a thermally conductive and wear-resistant lubricating oil, characterized in that, Kojic acid is used to functionalize silicon carbide and boron nitride, thereby improving their thermal conductivity and wear resistance without affecting lubrication performance. The components, by mass parts, are: The ingredients are: 85-95 parts base oil, 0.5-2 parts detergent, 0.1-1 part antioxidant, 0.5-2 parts dispersant, 0.2-0.9 parts passivator, 0.2-1 part rust inhibitor, and 1-3 parts functionalized silicon carbide and boron nitride mixed powder. The specific preparation method is as follows: Step 1: Mix silicon carbide and boron nitride powders by ball milling at a mass ratio of 1:(0.5~2) with methanol as the ball milling medium to obtain a ball milling slurry. Then, add kojic acid and silane coupling agent to the ball milling slurry at a mass ratio of 1:(3~10), with the total mass of kojic acid and silane coupling agent being 2~10% of the ball milling slurry. Then, shear emulsify the mixture in a high-speed shear mill. Step 2: Centrifuge the sheared emulsion to obtain a precipitate. Add deionized water to the precipitate and boil until crystallization occurs. Grind the precipitate and pass it through a 1000-3000 mesh sieve. Step 3: Heat the base oil to 70-90 degrees Celsius, then add detergent, antioxidant, dispersant, passivator, rust inhibitor and sieved precipitate according to the mass fraction, and stir to obtain heat-conducting lubricating oil.

2. The method for preparing thermally conductive and wear-resistant lubricating oil according to claim 1, characterized in that, In step one, the silane coupling agent is one or more of KH550, KH560, and KH570, the ball milling rate is 200~800 rpm, and the total high-speed shearing time is 8~12 h, with a 5 min pause after every 30~60 min of shearing.

3. The method for preparing thermally conductive and wear-resistant lubricating oil according to claim 1, characterized in that, In step two, the centrifugation rate is 3500~7200 rcf, the centrifugation time is 30~90 min, and the mass of deionized water added is 50~100 times that of the precipitate.

4. The method for preparing thermally conductive and wear-resistant lubricating oil according to claim 1, characterized in that, In step three, the stirring speed is 200~600 rpm and the stirring time is 0.5~4h.

5. A thermally conductive and wear-resistant lubricating oil prepared by any one of claims 1 to 4.

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