Special conductive PVC (polyvinyl chloride) composite material for equipment table board and preparation method thereof
By using high-structure conductive carbon black, conductive nano-copper powder and modified carbon nanotubes in PVC composite materials, combined with specific additives and processes, the problems of unstable conductivity and poor chemical resistance are solved, and the excellent conductivity and chemical resistance of the equipment table material are achieved.
Patent Information
- Application Number
- CN202510807965.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-17
- Publication Date
- 2025-09-16
AI Technical Summary
Existing conductive PVC composite materials are difficult to form a continuous and stable conductive network, are prone to aging and corrosion in acidic, alkaline or solvent environments, and have poor chemical resistance.
High-structure conductive carbon black, conductive nano-copper powder and modified carbon nanotubes are used as conductive fillers, combined with dioctyl terephthalate and ACR processing aids. Through premixing, staged plasticization and optimization of melt blending parameters, a stable and continuous conductive network is constructed to enhance interfacial bonding and chemical resistance.
The material's electrical conductivity and chemical resistance have been significantly improved, making it suitable for various equipment countertops, ensuring long-term stability and impact resistance.
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Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of polymer materials, and specifically relates to a conductive PVC composite material specially used for equipment countertops and a preparation method thereof. Background Art
[0002] With the continuous development of modern industry and electronic manufacturing technology, the demand for electrostatic protection in production environments is increasing. In places like semiconductors, precision electronics, medical equipment, and chemical laboratories, equipment countertops, which directly contact products or handle tools, are prone to static charge accumulation on their surfaces, triggering electrostatic discharge (ESD), which can cause component damage, data loss, and even safety accidents. Therefore, the development of equipment countertop materials with excellent electrical conductivity has become a key research direction in related fields.
[0003] Polyvinyl chloride (PVC), a general-purpose plastic widely used in the industrial field, is widely used due to its good processability, corrosion resistance, and cost advantages. However, PVC material itself is a polymer insulator and cannot meet the conductivity requirements of equipment countertop materials. Therefore, it is necessary to add conductive fillers to achieve conductivity of the material. Currently, common conductive PVC composite materials mainly achieve conductivity of PVC materials by adding conductive components such as metal powder to the base material. However, there are still many problems and shortcomings in practical applications. First, the addition of a single conductive filler often makes it difficult to form a continuous and stable conductive network, resulting in unstable conductivity of the material or decay over time. Second, equipment countertops are often exposed to chemicals and are prone to aging and corrosion in acidic, alkaline or solvent environments. Existing conductive PVC materials perform poorly in terms of chemical resistance.
[0004] Therefore, there is an urgent need to develop a conductive PVC composite material for equipment countertops with excellent conductivity and chemical resistance to solve the above technical problems and meet the diverse needs of high-end industries for equipment countertop materials. Summary of the Invention
[0005] In view of this, the present application provides a conductive PVC composite material for equipment countertops and a preparation method thereof. The conductive PVC composite material for equipment countertops provided in the present application has excellent electrical conductivity and chemical resistance.
[0006] In the first aspect, the present application provides a conductive PVC composite material specially used for equipment countertops. The raw material composition thereof includes, by weight: 80 to 120 parts of polyvinyl chloride resin, 80 to 120 parts of dioctyl terephthalate, 3 to 8 parts of stabilizer, 30 to 50 parts of high-structure conductive carbon black, 20 to 30 parts of conductive nano-copper powder, 1 to 5 parts of ACR processing aid, 0.5 to 3 parts of lubricant, and 1 to 5 parts of modified carbon nanotubes.
[0007] By adopting the above technical solution, the conductive PVC composite material for equipment countertops provided by this application significantly improves the conductivity and chemical resistance of the material. This application adopts high-structure conductive carbon black, conductive nano copper powder and modified carbon nanotubes as the main conductive fillers. The high-structure conductive carbon black provides a basic conductive network, and its complex three-dimensional structure and large specific surface area help to form a preliminary conductive path. The conductive nano copper powder fills the gaps between the carbon black, further improving the overall conductive efficiency. The modified carbon nanotubes act as a "conductive bridge" to connect the carbon black and copper powder particles, constructing a denser and more stable conductive path, and can also enhance the interfacial bonding force with the PVC matrix, forming a physical barrier, effectively preventing chemicals from penetrating into the interior of the material, thereby significantly improving the chemical resistance of the material.
[0008] The dioctyl terephthalate (DOTP) in this application improves the flexibility and processing fluidity of PVC. Its low volatility also provides better resistance to acid, alkali, and solvent corrosion. The ACR processing aid optimizes the rheological properties of PVC in its molten state, promoting uniform plasticization and preventing damage to the conductive filler due to excessive shear forces, thereby ensuring the integrity of the conductive network.
[0009] The raw materials of the present application work together to achieve a dual improvement in the electrical conductivity and chemical resistance of the conductive PVC composite material, and are suitable for various equipment countertops.
[0010] Optionally, the polyvinyl chloride resin is PVC-2500.
[0011] By adopting the above technical solution, the polyvinyl chloride resin of the present application is selected from the PVC-2500 model, which has a high degree of polymerization and can give the material excellent mechanical strength, heat resistance and processing stability, which helps to improve the overall structural stability and impact resistance of the composite material.
[0012] Optionally, the stabilizer includes at least one of calcium stearate, di-n-butyltin dilaurate, and methyltin mercaptan.
[0013] By adopting the above technical solution, the stabilizer of the present application can not only enable the conductive PVC composite material to maintain excellent thermal stability during the processing process, avoiding material degradation caused by high temperature, but also resist the influence of external environmental factors during long-term use, ensuring that the mechanical properties and conductive properties of the material do not decay over time.
[0014] Optionally, the specific surface area of the high-structure conductive carbon black is 800m 2 / g~1500m 2 / g.
[0015] By adopting the above technical solution, the specific surface area of the high-structure conductive carbon black in this application not only ensures that it forms an efficient and stable conductive network in the PVC matrix, but also takes into account the dispersion and fluidity requirements during the processing, effectively improving the chemical resistance of the conductive PVC composite material.
[0016] Optionally, the DBP oil absorption value of the high-structure conductive carbon black is 300 mL / 100 g to 400 mL / 100 g.
[0017] By adopting the above technical solution, the DBP oil absorption value of the high-structure conductive carbon black in this application ensures excellent dispersibility and conductivity of the carbon black in the PVC matrix, helping to enhance its ability to form a continuous conductive path in the PVC matrix, thereby improving the conductive properties of the material. In addition, a higher DBP value also indicates that the carbon black surface has a stronger adsorption capacity, which can better interact with plasticizers such as DOTP, promote their uniform distribution in the matrix, and further optimize the stability and conductivity efficiency of the conductive network.
[0018] Optionally, the average particle size of the conductive nano-copper powder is 70 nm to 100 nm.
[0019] By adopting the above technical solution, the average particle size range of the conductive nano-copper powder in this application ensures that the copper powder particles have good fluidity and can be relatively evenly dispersed in the PVC matrix. Furthermore, the nano-copper powder within this particle size range can better fill the gaps between the high-structure conductive carbon black, forming a denser and more continuous conductive path, thereby improving the overall conductive performance.
[0020] Optionally, the lubricant is selected from at least one of stearic acid, oxidized polyethylene wax, and fatty alcohol polyoxyethylene ether.
[0021] By adopting the above technical solution, the lubricant of the present application can significantly improve its processing fluidity and surface finish while ensuring that the conductive properties of the material are not affected. It not only optimizes the processing performance and surface quality of the conductive PVC composite material, but also enhances its applicability and stability under complex process conditions. Optionally, the weight ratio of the high-structure conductive carbon black to the modified carbon nanotubes is 15 to 25:1.
[0022] By adopting the above technical solution, the present application uses high-structure conductive carbon black and modified carbon nanotubes together, which can give full play to the joint effect of the two while ensuring the conductive performance. Carbon black provides the main conductive path, while a small amount of carbon nanotubes acts as a "connecting node", significantly reducing the overall resistivity. In addition, carbon nanotubes have a certain barrier effect, which can reduce the erosion of external corrosive media on the PVC matrix and conductive fillers, and help improve the stability of the material in acid, alkali or solvent environments. The specific ratio of high-structure conductive carbon black and modified carbon nanotubes not only optimizes the construction method of the conductive network, improves the conductive efficiency and stability of the material, but also improves the chemical resistance of the material.
[0023] Optionally, the weight ratio of the high-structure conductive carbon black to the modified carbon nanotubes is 20:1.
[0024] In a second aspect, the present application provides a method for preparing the above-mentioned conductive PVC composite material for equipment countertops, comprising the following steps: Step S1, mixing the high-structure conductive carbon black, conductive nano-copper powder and modified carbon nanotubes for 10 to 20 minutes to prepare a premix; Step S2, mixing the polyvinyl chloride resin and 50% of the dioctyl terephthalate, heating the mixture to 120° C. to 130° C., stirring the mixture for 5 to 10 minutes at a stirring speed of 300 rpm to 500 rpm, and then sequentially adding another 50% of the dioctyl terephthalate, the premix, the stabilizer, the ACR processing aid, and the lubricant, heating the mixture to 160° C. to 190° C., and stirring the mixture for 10 to 15 minutes to obtain a mixture; Step S3: Extruding the mixture into a shape, cooling and granulating the mixture to obtain a conductive PVC composite material specifically for equipment countertops.
[0025] By adopting the above-mentioned technical solution, the preparation method provided in the present application achieves efficient dispersion and interaction of conductive fillers in the PVC matrix through premixing of conductive fillers, staged plasticization, optimization of melt blending parameters and reasonable selection of additives, thereby constructing a stable and continuous conductive network. The obtained conductive PVC composite material for equipment countertops not only has excellent conductive properties, but also has outstanding chemical resistance.
[0026] Optionally, the preparation steps of the modified carbon nanotubes are: Step 1: adding carbon nanotubes to ethanol, ultrasonically treating for 0.5 to 2 hours, adding a silane coupling agent, and stirring for 4 to 8 hours to prepare a mixture; wherein the mass volume ratio of carbon nanotubes to ethanol is 1:500 to 1000 g / mL, and the mass ratio of silane coupling agent to carbon nanotubes is 0.05 to 0.2:1; Step 2: Filter the mixture, wash it with ethanol for 3 to 5 times, and dry it to obtain modified carbon nanotubes.
[0027] By adopting the above technical solution, the present application functionalizes the carbon nanotubes, and the introduced functional groups improve the compatibility between the carbon nanotubes and PVC, which helps to build a stable conductive network and also makes it have good dispersibility, excellent conductivity and chemical resistance.
[0028] Optionally, the silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and vinyltriethoxysilane.
[0029] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The conductive PVC composite material for equipment countertops provided in this application achieves a dual improvement in conductivity and chemical resistance and is suitable for various equipment countertops.
[0030] 2. The preparation method provided in this application achieves efficient dispersion and interaction of conductive fillers in the PVC matrix through premixing of conductive fillers, staged plasticization, optimization of melt blending parameters and reasonable selection of additives, thereby constructing a stable and continuous conductive network. The resulting conductive PVC composite material for equipment countertops not only has excellent conductive properties, but also has outstanding chemical resistance. DETAILED DESCRIPTION
[0031] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0032] During their research on conductive PVC materials, the inventors of this application discovered that conventional conductive PVC materials have difficulty forming a continuous and stable conductive network in practical applications, resulting in unstable conductivity. Furthermore, they are susceptible to aging and corrosion when exposed to acidic, alkaline, or solvent environments, and exhibit poor chemical resistance.
[0033] In order to solve the above problems, the present application proposes a conductive PVC composite material specially used for equipment countertops. The raw material composition thereof includes, by weight: 80-120 parts of polyvinyl chloride resin, 80-120 parts of dioctyl terephthalate, 3-8 parts of stabilizer, 30-50 parts of high-structure conductive carbon black, 20-30 parts of conductive nano-copper powder, 1-5 parts of ACR processing aid, 0.5-3 parts of lubricant, and 1-5 parts of modified carbon nanotubes.
[0034] The present application also proposes a method for preparing the above-mentioned conductive PVC composite material for the equipment table, comprising the following steps: Step S1, mixing high-structure conductive carbon black, conductive nano-copper powder and modified carbon nanotubes for 10 minutes to 20 minutes to prepare a premix; Step S2, mixing polyvinyl chloride resin and 50% dioctyl terephthalate, heating to 120° C. to 130° C., stirring for 5 to 10 minutes at a stirring speed of 300 rpm to 500 rpm, then sequentially adding another 50% dioctyl terephthalate, premix, stabilizer, ACR processing aid, and lubricant, heating to 160° C. to 190° C., and stirring for 10 to 15 minutes to obtain a mixture; Step S3: Extruding the mixture into a shape, cooling and granulating the mixture to obtain a conductive PVC composite material specially used for equipment countertops.
[0035] The scheme of the present application is described below with reference to the following specific examples. Unless otherwise specified, the raw materials used in the following examples are all from common commercial products, and the devices or equipment used are all purchased from conventional market sales channels. Specific embodiments
[0036] The preparation steps of the modified carbon nanotubes used in Examples 1 to 3 are as follows: Step 1: adding carbon nanotubes to ethanol, ultrasonically treating for 2 hours, adding a silane coupling agent, stirring and reacting for 6 hours to prepare a mixture; wherein the mass volume ratio of carbon nanotubes to ethanol is 1g:800mL, and the mass ratio of silane coupling agent to carbon nanotubes is 0.1:1; the silane coupling agent is vinyltriethoxysilane; Step 2: Filter the mixture, wash it with ethanol 3 to 5 times, and dry it to obtain modified carbon nanotubes.
[0037] Examples 1 to 3 Example 1 This embodiment provides a conductive PVC composite material for equipment countertops, the raw materials of which are composed, by weight, of: 80 parts of polyvinyl chloride resin, 120 parts of dioctyl terephthalate, 8 parts of stabilizer, 30 parts of high-structure conductive carbon black, 30 parts of conductive nano-copper powder, 5 parts of ACR processing aid, 0.5 parts of lubricant, and 1 part of modified carbon nanotubes; Wherein, the polyvinyl chloride resin is PVC-2500; the stabilizer is calcium stearate; The specific surface area of high structure conductive carbon black is 800m 2 / g; DBP oil absorption value is 300mL / 100g; the average particle size of the conductive nano-copper powder is 70nm; the lubricant is oxidized polyethylene wax; The preparation method comprises the following steps: Step S1, mixing high-structure conductive carbon black, conductive nano-copper powder and modified carbon nanotubes for 10 minutes to prepare a premix; Step S2: Mixing polyvinyl chloride resin and 50% dioctyl terephthalate, heating to 120° C., stirring for 10 minutes at a stirring speed of 300 rpm, and then sequentially adding another 50% dioctyl terephthalate, premix, stabilizer, ACR processing aid, and lubricant, heating to 160° C., and stirring for 15 minutes to prepare a mixture; Step S3: Extruding the mixture into a shape, cooling and granulating the mixture to obtain a conductive PVC composite material specially used for equipment countertops.
[0038] Example 2 This embodiment provides a conductive PVC composite material for equipment countertops, the raw materials of which are composed, by weight, of: 100 parts of polyvinyl chloride resin, 100 parts of dioctyl terephthalate, 5 parts of stabilizer, 40 parts of high-structure conductive carbon black, 25 parts of conductive nano-copper powder, 3 parts of ACR processing aid, 1.5 parts of lubricant, and 3 parts of modified carbon nanotubes; Wherein, the polyvinyl chloride resin is PVC-2500; the stabilizer is calcium stearate; The specific surface area of high structure conductive carbon black is 800m 2 / g; DBP oil absorption value is 350mL / 100g; the average particle size of the conductive nano-copper powder is 70nm; the lubricant is oxidized polyethylene wax; The preparation method comprises the following steps: Step S1, mixing high-structure conductive carbon black, conductive nano-copper powder and modified carbon nanotubes for 15 minutes to prepare a premix; Step S2: Mixing polyvinyl chloride resin and 50% dioctyl terephthalate, heating to 125° C., stirring for 8 minutes at a stirring speed of 400 rpm, and then sequentially adding another 50% dioctyl terephthalate, premix, stabilizer, ACR processing aid, and lubricant, heating to 175° C., and stirring for 12 minutes to prepare a mixture; Step S3: Extruding the mixture into a shape, cooling and granulating the mixture to obtain a conductive PVC composite material specially used for equipment countertops.
[0039] Example 3 This embodiment provides a conductive PVC composite material for equipment countertops, the raw materials of which are composed, by weight, of: 120 parts of polyvinyl chloride resin, 80 parts of dioctyl terephthalate, 3 parts of stabilizer, 50 parts of high-structure conductive carbon black, 20 parts of conductive nano-copper powder, 1 part of ACR processing aid, 3 parts of lubricant, and 5 parts of modified carbon nanotubes; Wherein, the polyvinyl chloride resin is PVC-2500; the stabilizer is calcium stearate; The specific surface area of high structure conductive carbon black is 800m 2 / g; DBP oil absorption value is 400mL / 100g; the average particle size of the conductive nano-copper powder is 70nm; the lubricant is oxidized polyethylene wax; The preparation method comprises the following steps: Step S1, mixing high-structure conductive carbon black, conductive nano-copper powder and modified carbon nanotubes for 20 minutes to prepare a premix; Step S2: Mixing polyvinyl chloride resin and 50% dioctyl terephthalate, heating to 130° C., stirring for 5 minutes at a stirring speed of 500 rpm, and then sequentially adding another 50% dioctyl terephthalate, premix, stabilizer, ACR processing aid, and lubricant, heating to 190° C., and stirring for 10 minutes to prepare a mixture; Step S3: Extruding the mixture into a shape, cooling and granulating the mixture to obtain a conductive PVC composite material specially used for equipment countertops.
[0040] Comparative Examples 1 to 3 Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that high-structure conductive carbon black is not added in Comparative Example 1.
[0041] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that no conductive nano-copper powder is added in Comparative Example 2.
[0042] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that no modified carbon nanotubes are added in Comparative Example 3.
[0043] Experimental testing Test items and test methods Conductivity: According to GB / T 1410-2006 "Test method for volume resistivity and surface resistivity of solid insulating materials", the volume resistivity of the prepared conductive PVC composite material at 23°C is tested. The smaller the volume resistivity, the better the conductivity of the material.
[0044] Chemical resistance: The chemical resistance of the conductive PVC composite material was tested according to GB / T 11547-2008 "Plastics - Determination of Resistance to Liquid Chemicals". The samples were immersed in 30% by mass hydrochloric acid at 70°C for 16 weeks. Changes in appearance were visually inspected. Appearance changes were graded as follows: no change, insignificant change, slight change, moderate change, and severe change.
[0045] The conductive PVC composite materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested for conductivity and chemical resistance. The test results are shown in Table 1.
[0046] Table 1 From the test results in Table 1, it can be seen that the conductive PVC composite materials prepared in Examples 1 to 3 have low volume resistivity, good conductivity and excellent chemical resistance.
[0047] Comparative Example 1 did not add high-structure conductive carbon black, Comparative Example 2 did not add conductive nano-copper powder, and Comparative Example 3 did not add modified carbon nanotubes. The conductivity and chemical resistance of the conductive PVC composite materials prepared in Comparative Examples 1 to 3 were significantly reduced.
[0048] Examples 4 to 9 Example 4 The difference between Example 4 and Example 2 is that in Example 4, the specific surface area of the high-structure conductive carbon black is 1100m 2 / g.
[0049] Example 5 The difference between Example 5 and Example 2 is that in Example 5, the specific surface area of the high-structure conductive carbon black is 1500m 2 / g.
[0050] Example 6 The difference between Example 6 and Example 4 is that in Example 6, the average particle size of the conductive nano-copper powder is 85 nm.
[0051] Example 7 The difference between Example 7 and Example 4 is that in Example 7, the average particle size of the conductive nano-copper powder is 100 nm.
[0052] Example 8 The difference between Example 8 and Example 6 is that in Example 8, the total weight of the high-structure conductive carbon black and the modified carbon nanotubes is 43 parts, and the mass ratio of the high-structure conductive carbon black to the modified carbon nanotubes is 20:1.
[0053] Example 9 The difference between Example 9 and Example 6 is that in Example 9, the total weight of the high-structure conductive carbon black and the modified carbon nanotubes is 43 parts, and the mass ratio of the high-structure conductive carbon black to the modified carbon nanotubes is 25:1.
[0054] The conductive PVC composite materials prepared in Examples 4 to 9 were tested for conductivity and chemical resistance. The test results are shown in Table 2.
[0055] Table 2 From the test results in Table 2, it can be seen that the difference between Example 4 and Example 5 and Example 2 is that the specific surface areas of the high-structure conductive carbon black are different. Among them, the conductive PVC composite material prepared in Example 4 has the best conductivity.
[0056] The difference between Example 6 and Example 7 and Example 4 is that the average particle sizes of the conductive nano-copper powders are different. Among them, the conductive PVC composite material prepared in Example 6 has the best conductivity.
[0057] The difference between Example 8 and Example 9 and Example 6 is that the mass ratios of high-structure conductive carbon black and modified carbon nanotubes are different. Among them, the conductive PVC composite material prepared in Example 8 has the best conductivity.
[0058] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the principles of the present application should be included in the scope of protection of the present application.
Claims
1. A conductive PVC composite material for equipment countertops, characterized in that: The raw material composition includes, by weight, 80 to 120 parts of polyvinyl chloride resin, 80 to 120 parts of dioctyl terephthalate, 3 to 8 parts of stabilizer, 30 to 50 parts of high-structure conductive carbon black, 20 to 30 parts of conductive nano copper powder, 1 to 5 parts of ACR processing aid, 0.5 to 3 parts of lubricant, and 1 to 5 parts of modified carbon nanotubes.
2. The composite material according to claim 1, characterized in that The polyvinyl chloride resin is PVC-2500.
3. The composite material according to claim 1, characterized in that The stabilizer includes at least one of calcium stearate, di-n-butyltin dilaurate, and methyltin mercaptan.
4. The composite material according to claim 1, characterized in that The specific surface area of the high-structure conductive carbon black is 800m 2 / g~1500m 2 / g.
5. The composite material according to claim 1, characterized in that The DBP oil absorption value of the high-structure conductive carbon black is 300 mL / 100 g to 400 mL / 100 g.
6. The composite material according to claim 1, characterized in that The average particle size of the conductive nano copper powder is 70nm to 100nm.
7. The composite material according to claim 1, characterized in that The lubricant is selected from at least one of stearic acid, oxidized polyethylene wax, and fatty alcohol polyoxyethylene ether.
8. The composite material according to claim 1, characterized in that The weight ratio of the high-structure conductive carbon black to the modified carbon nanotubes is 15-25:
1.
9. A method for preparing the conductive PVC composite material for equipment countertops according to claim 1, characterized in that: The following steps are involved: Step S1, mixing the high-structure conductive carbon black, conductive nano-copper powder and modified carbon nanotubes for 10 to 20 minutes to prepare a premix; Step S2, mixing the polyvinyl chloride resin and 50% of the dioctyl terephthalate, heating the mixture to 120° C. to 130° C., stirring the mixture for 5 to 10 minutes at a stirring speed of 300 rpm to 500 rpm, and then sequentially adding another 50% of the dioctyl terephthalate, the premix, the stabilizer, the ACR processing aid, and the lubricant, heating the mixture to 160° C. to 190° C., and stirring the mixture for 10 to 15 minutes to obtain a mixture; Step S3: Extruding the mixture into a shape, cooling and granulating the mixture to obtain a conductive PVC composite material specifically for equipment countertops.
10. The preparation method according to claim 9, characterized in that The preparation steps of the modified carbon nanotubes are: Step 1: adding carbon nanotubes to ethanol, ultrasonically treating for 0.5 to 2 hours, adding a silane coupling agent, and stirring for 4 to 8 hours to prepare a mixture; wherein the mass volume ratio of carbon nanotubes to ethanol is 1:500 to 1000 g / mL, and the mass ratio of silane coupling agent to carbon nanotubes is 0.05 to 0.2:1; Step 2: Filter the mixture, wash it with ethanol for 3 to 5 times, and dry it to obtain modified carbon nanotubes.