CN119307012B - Antistatic agent and preparation method and application thereof - Google Patents

Abstract

The present invention relates to an antistatic agent and a preparation method and application thereof, belonging to the technical field of plastic additives, and solving at least one of the problems of poor dispersibility, insufficient conductivity, easy oxidation, insufficient thermal stability and uniformity, easy aggregation or sedimentation of existing antistatic agents. The preparation method of the antistatic agent of the present invention comprises the steps of silane coupling agent modification, polyaniline coating, silica loading, etc., to obtain a novel SiO2 _- CNTs composite material. The antistatic agent has good dispersibility, excellent conductivity, good thermal stability and uniformity, and the oil prepared by the antistatic agent is used to treat ultra-high molecular weight polyethylene fiber, which helps to improve the continuity and uniformity of the fiber in the production process, and reduce the incidence of breakage and defects; and the fiber has excellent high temperature resistance and antistatic performance.

Description

Antistatic agent and preparation method and application thereof

Technical Field

The invention relates to the technical field of plastic additives, and in particular to an antistatic agent and a preparation method and application thereof.

Background Art

Ultra-high molecular weight polyethylene (UHMWPE) fiber has been widely used in many fields due to its excellent mechanical properties, such as bulletproof vests, cut-resistant gloves, ropes, fishing nets and medical devices. UHMWPE fiber has extremely high strength, excellent wear resistance, low friction coefficient and good impact resistance. However, this fiber also has some significant disadvantages in practical applications, mainly including poor heat resistance and poor antistatic performance.

The melting point of UHMWPE fiber is low, about 130°C, which is much lower than the melting point of other high-performance fibers (such as aramid fibers). In high-temperature environments, UHMWPE fibers are prone to deformation and degradation, resulting in a significant decrease in their mechanical properties. For example, in industrial high-temperature environment applications, the heat resistance of the material directly affects its service life and safety. In addition, the heat treatment processes involved in the textile processing, such as heat setting and ironing, will also have an adverse effect on UHMWPE fibers, limiting their application in these fields.

UHMWPE fiber has poor antistatic performance, which is mainly due to its extremely low conductivity, which makes it easy to accumulate static electricity during use. The accumulation of static electricity not only affects the processing performance of the fiber, such as easily absorbing dust and impurities during spinning, weaving and finishing, resulting in a decline in product quality; at the same time, in certain specific environments, such as flammable and explosive environments, the accumulation of static electricity may cause fire or explosion, posing a serious safety hazard.

At present, there are some modification methods and treatment technologies on the market to address the problems of poor heat resistance and poor antistatic performance of UHMWPE fibers. For example, by coating the fiber surface with high temperature resistant materials to improve its heat resistance, or adding antistatic agents to improve its antistatic performance. However, existing antistatic agents have problems such as poor dispersibility, insufficient conductivity, easy oxidation, insufficient thermal stability and uniformity, and easy aggregation or sedimentation, resulting in poor thermal stability, easy breakage, and high static voltage of the treated ultra-high molecular weight polyethylene (UHMWPE) fibers.

Therefore, it is necessary to develop an antistatic agent with good dispersibility, conductivity and thermal stability and a matching special oil for ultra-high molecular weight polyethylene (UHMWPE) fibers.

Summary of the invention

In view of the above analysis, the embodiments of the present invention aim to provide an antistatic agent and a preparation method and application thereof, so as to solve at least one of the problems of existing antistatic agents, such as poor dispersibility, insufficient conductivity, easy oxidation, insufficient thermal stability and uniformity, and easy aggregation or sedimentation.

The present invention provides a method for preparing an antistatic agent, comprising: firstly modifying carbon nanotubes with a silane coupling agent, then coating the modified carbon nanotubes with polyaniline, and finally loading the modified carbon nanotubes coated with polyaniline on a silicon dioxide carrier to obtain a finished _SiO2 -CNTs composite material, namely the antistatic agent.

The specific steps are as follows:

S1: weighing or measuring carbon nanotubes and ethanol, adding the carbon nanotubes into the ethanol and performing ultrasonic dispersion to obtain a carbon nanotube solution;

S2: taking a quantity of silane coupling agent and dissolving it in ethanol, slowly adding distilled water under stirring conditions, adjusting the pH value, and allowing the mixed solution to stand until the silane coupling agent is fully hydrolyzed to obtain a silane coupling agent solution;

S3: slowly adding the carbon nanotube solution into the silane coupling agent solution and stirring, and obtaining a reaction mixture after the reaction is completed;

S4: baking the reaction mixture, cooling it to room temperature and then vacuum drying it to obtain carbon nanotubes modified with a silane coupling agent;

S5: ultrasonically dispersing the carbon nanotubes modified with the silane coupling agent in an aqueous solution and adding aniline, stirring and mixing the mixture thoroughly; cooling the mixture in an ice bath and adding an ammonium persulfate solution, stirring the mixture at 0°C, and after the reaction is completed, filtering, washing and drying the mixture to obtain the polyaniline-coated carbon nanotubes;

S6: adding the polyaniline-coated carbon nanotubes to an aqueous solution containing sodium dodecylbenzene sulfonate, and subjecting the solution to ultrasonic treatment to obtain a carbon nanotube suspension; slowly adding silicon dioxide powder to the carbon nanotube suspension, stirring evenly, and heating and continuing to stir to obtain a composite semi-finished product;

S7: drying and heat treating the semi-finished composite material, and after cooling, screening and washing to obtain a finished SiO2-CNTs composite material, namely the antistatic agent.

Specifically, in step S1, the mass ratio of carbon nanotubes to ethanol is 1:100-120.

Specifically, in step S2, the volume ratio of the silane coupling agent to ethanol is 1:10-12; the volume ratio of the silane coupling agent to distilled water is 1:3-3.5; the pH value adjustment interval is 4-5, and the standing time is ≥2h; the silane coupling agent is KH-550 or KH-560.

Specifically, in step S3, the mass ratio of the silane coupling agent solution to the carbon nanotube solution is 0.2-0.4:1, and the stirring time is ≥4 hours.

Specifically, the specific operation of step S4 is: transferring the reaction mixture to a constant temperature oven and keeping it at 80-100° C. for 12-14 hours; after cooling to room temperature, drying the reaction mixture in a vacuum drying oven for 24-30 hours to obtain carbon nanotubes modified with a silane coupling agent.

Specifically, in step S5, the mass ratio of carbon nanotubes modified with silane coupling agent to aniline is 1:6-10; the mass ratio of ammonium persulfate to aniline is 0.05-0.1:1, and the reaction time is 4-6 hours.

Specifically, in step S6, the mass concentration of the sodium dodecylbenzene sulfonate aqueous solution is 1-1.2%, the volume ratio of the polyaniline-coated carbon nanotubes to the sodium dodecylbenzene sulfonate aqueous solution is 1:400-500; the mass ratio of the silicon dioxide powder to the polyaniline-coated carbon nanotubes is 8-15:1, the heating temperature is 80° C.-100° C., and the reaction time is ≥3 hours.

Specifically, the specific operation of the heat treatment in step S7 is to dry the semi-finished composite material in air, and then heat it to 500±100° C. in a tube furnace at a heating rate of 5±1° C./min for a treatment time of 120 to 160 min.

The invention also discloses an antistatic agent, which is prepared by the preparation method.

The invention also discloses an oil agent for ultra-high molecular weight polyethylene fibers, wherein the oil agent comprises the above-mentioned antistatic agent.

Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

1. The antistatic agent provided by the present invention has good antistatic performance, excellent dispersibility, conductivity, antioxidant properties and thermal stability; the ultra-high molecular weight polyethylene fiber treated with the oil containing the antistatic agent has an electrostatic voltage of ≤0.041 kV, an initial modulus of ≥1900 cN/dtex, an initial breaking strength of ≥40.0 cN/dtex, and a small decrease in breaking strength under high temperature conditions.

The present invention adopts carbon nanotubes as the main matrix of the antistatic agent. Carbon nanotubes have good thermal and electrical conductivity, so they can be used as good thermal and antistatic materials. However, due to its unique carbon structure, the surface of carbon nanotubes is mainly hydrophobic, which makes them less dispersible in oil (organic solvent). The present invention adopts silane coupling agent to modify it, and the siloxane group can form a covalent bond with the functional group (such as carboxyl, hydroxyl, etc.) on the surface of the carbon nanotube through condensation reaction, thereby anchoring on the surface of the carbon nanotube. By introducing flexible segments to provide sufficient steric hindrance, direct contact between carbon nanotubes and the effect of van der Waals force are avoided. The modified carbon nanotubes are not easy to aggregate or re-aggregate, making it easier to interact with the organic molecules in the oil, thereby improving the dispersibility of the carbon nanotubes in the oil.

Compared with other polymers, polyaniline has good electrical conductivity. Both polyaniline and carbon nanotubes are rich in π electron systems. The continuous electron transport network formed by π-π stacking interaction can effectively improve the overall electrical conductivity of the material. Carbon nanotubes provide fast electron transport channels, and the conductivity of polyaniline further enhances these channels. This enhanced electron transport ability allows charges to be quickly conducted on the surface or in the body of the material, thereby effectively dissipating static electricity accumulation and reducing the generation and accumulation of static electricity. Furthermore, through π-π interactions, the polyaniline molecular chain forms a uniform and continuous coating on the surface of carbon nanotubes, which can act as a physical barrier to prevent the oxidation of carbon nanotubes during processing or application.

Silica has excellent thermal stability and can maintain its physical and chemical properties unchanged in high temperature environments, thus providing a stable base for the entire composite material. By introducing polyaniline-coated carbon nanotubes supported by silica carriers in the spinning oil, the thermal stability of the fiber during processing and application can be increased, especially in environments that need to withstand high temperature processing or operation, to avoid the loss or decomposition of antistatic agents under high temperature conditions and thus failure. On the other hand, the surface roughness and pore structure of silica particles also help to physically embed or attach carbon nanotubes, reducing the sedimentation or aggregation of carbon nanotubes in the oil. Ensure that the processing quality and performance of each batch of fibers are consistent. This improved dispersibility helps the continuity and uniformity of the fiber during the production process and reduces the incidence of breakage and defects.

The ultra-high molecular weight polyethylene fiber treated with the oil containing the antistatic agent has an electrostatic voltage of ≤0.041 kV, an initial modulus of ≥1900 cN/dtex, an initial breaking strength of ≥40.0 cN/dtex, and a small decrease in breaking strength under high temperature conditions.

2. When the antistatic agent is prepared by the preferred process parameters of the present invention, the uniformity and stability of the antistatic agent product can be improved, including but not limited to the sufficient modification of the silane coupling agent, the uniformity and appropriate thickness of the polyaniline coating, the loading effect of the silica carrier, etc.

3. The antistatic agent and oil agent provided by the present invention have readily available raw materials and equipment and can be purchased directly; the preparation process is relatively simple, the process conditions are relatively mild, the preparation difficulty is relatively low, and the existing oiling process can be used for oiling, which is suitable for large-scale production and wide application.

In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

FIG1 is a physical photograph of the oil for ultra-high molecular weight polyethylene fiber in Example 1;

Figure 2 is a flow chart for the preparation of an antistatic agent.

DETAILED DESCRIPTION

The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

The present invention provides a method for preparing an antistatic agent, comprising: firstly modifying carbon nanotubes with a silane coupling agent, then coating the modified carbon nanotubes with polyaniline, and finally loading the modified carbon nanotubes coated with polyaniline on a silicon dioxide carrier to obtain a finished _SiO2 -CNTs composite material, namely the antistatic agent.

The present invention adopts carbon nanotubes as the main matrix of the antistatic agent. Carbon nanotubes have good thermal and electrical conductivity, so they can be used as good thermal and antistatic materials. However, due to its unique carbon structure, the surface of carbon nanotubes is mainly hydrophobic, which makes them less dispersible in oil (organic solvent). The present invention adopts silane coupling agent to modify it, and the siloxane group can form a covalent bond with the functional group (such as carboxyl, hydroxyl, etc.) on the surface of the carbon nanotube through condensation reaction, thereby anchoring on the surface of the carbon nanotube. By introducing flexible segments to provide sufficient steric hindrance, direct contact between carbon nanotubes and the effect of van der Waals force are avoided. The modified carbon nanotubes are not easy to aggregate or re-aggregate, making it easier to interact with the organic molecules in the oil, thereby improving the dispersibility of the carbon nanotubes in the oil.

Compared with other polymers, polyaniline has good electrical conductivity. Both polyaniline and carbon nanotubes are rich in π electron systems. The continuous electron transport network formed by π-π stacking interaction can effectively improve the overall electrical conductivity of the material. Carbon nanotubes provide fast electron transport channels, and the conductivity of polyaniline further enhances these channels. This enhanced electron transport ability allows charges to be quickly conducted on the surface or in the body of the material, thereby effectively dissipating static electricity accumulation and reducing the generation and accumulation of static electricity. Furthermore, through π-π interactions, the polyaniline molecular chain forms a uniform and continuous coating on the surface of carbon nanotubes, which can act as a physical barrier to prevent the oxidation of carbon nanotubes during processing or application.

Silica has excellent thermal stability and can maintain its physical and chemical properties unchanged in high temperature environments, thus providing a stable base for the entire composite material. By introducing polyaniline-coated carbon nanotubes supported by silica carriers in the spinning oil, the thermal stability of the fiber during processing and application can be increased, especially in environments that need to withstand high temperature processing or operation, to avoid the loss or decomposition of antistatic agents under high temperature conditions and thus failure. On the other hand, the surface roughness and pore structure of silica particles also help to physically embed or attach carbon nanotubes, reducing the sedimentation or aggregation of carbon nanotubes in the oil. Ensure that the processing quality and performance of each batch of fibers are consistent. This improved dispersibility helps the continuity and uniformity of the fiber during the production process and reduces the incidence of breakage and defects.

The specific steps include:

S1: weighing or measuring carbon nanotubes and ethanol, adding the carbon nanotubes into the ethanol and performing ultrasonic dispersion to obtain a carbon nanotube solution;

S2: taking a quantity of silane coupling agent and dissolving it in ethanol, slowly adding distilled water under stirring conditions, adjusting the pH value, and allowing the mixed solution to stand until the silane coupling agent is fully hydrolyzed to obtain a silane coupling agent solution;

S3: slowly adding the carbon nanotube solution into the silane coupling agent solution and stirring, and obtaining a reaction mixture after the reaction is completed;

S4: baking the reaction mixture, cooling it to room temperature and then vacuum drying it to obtain carbon nanotubes modified with a silane coupling agent;

S5: ultrasonically dispersing the carbon nanotubes modified with the silane coupling agent in an aqueous solution and adding aniline, stirring and mixing the mixture thoroughly; cooling the mixture in an ice bath and adding an ammonium persulfate solution, stirring the mixture at 0°C, and after the reaction is completed, filtering, washing and drying the mixture to obtain the polyaniline-coated carbon nanotubes;

S6: adding the polyaniline-coated carbon nanotubes to an aqueous solution containing sodium dodecylbenzene sulfonate, and subjecting the solution to ultrasonic treatment to obtain a carbon nanotube suspension; slowly adding silicon dioxide powder to the carbon nanotube suspension, stirring evenly, and heating and continuing to stir to obtain a composite semi-finished product;

S7: drying and heat treating the semi-finished composite material product, and after cooling, screening and washing to obtain a finished SiO ₂ -CNTs composite material product, namely the antistatic agent.

Specifically, the main purpose of step S1 is to pre-treat the carbon nanotubes by adding the carbon nanotubes into ethanol and ultrasonically dispersing them for more than 30 minutes using an ultrasonic processor, which can effectively remove impurities and aggregates on the surface of the carbon nanotubes.

Specifically, in step S1, the mass ratio of carbon nanotubes to ethanol is 1:100-120. If too much carbon nanotubes are added, the impurity removal effect is poor; if too little carbon nanotubes are added, the preparation/production efficiency is reduced.

Specifically, in step S2, the volume ratio of the silane coupling agent to ethanol is 1:10-12; the volume ratio of the silane coupling agent to distilled water is 1:3-3.5; the pH value adjustment interval is 4-5, and the standing time is ≥2h; the silane coupling agent is KH-550 or KH-560. The hydrolysis reaction of the silane coupling agent (such as KH-550 or KH-560) in water is significantly affected by the pH value. Under neutral or slightly acidic conditions, the hydrolysis rate of these coupling agents is moderate, which is conducive to controlling the progress of the reaction and the quality of the product. If the pH value is too high (alkaline), the silane coupling agent may hydrolyze too quickly, resulting in unstable products; if the pH value is too low (too acidic), the hydrolysis of the coupling agent may be inhibited, affecting the final reaction effect. The pH value in the range of 4 to 5 helps the silane groups on the silane coupling agent to react more effectively with the functional groups (such as carboxyl, hydroxyl, etc.) on the surface of the carbon nanotubes. This coupling effect can improve the interfacial compatibility and make the modified carbon nanotubes better dispersed in the final composite material. At a specified pH value and standing time (at least 2 hours), preferably 2 to 6 hours, it can ensure that the silane coupling agent is fully hydrolyzed without excessive polymerization, which is beneficial to subsequent processing and application. Sufficient hydrolysis is a prerequisite for ensuring that the coupling agent can effectively act on carbon nanotubes and other matrix materials.

Specifically, the pH regulator used is potassium hydroxide or triethanolamine.

Specifically, in step S3, the mass ratio of the silane coupling agent solution to the carbon nanotube solution is 0.2 to 0.4:1, and the stirring time is ≥4 hours to ensure sufficient contact and reaction between the carbon nanotubes and the coupling agent. The siloxane group can form a covalent bond with the functional groups (such as carboxyl and hydroxyl) on the surface of the carbon nanotube through a condensation reaction, thereby anchoring on the surface of the carbon nanotube. By introducing a flexible segment to provide sufficient steric hindrance, direct contact between the carbon nanotubes and the action of van der Waals forces are avoided. The modified carbon nanotubes are not easy to aggregate or re-aggregate, making it easier to interact with the organic molecules in the oil, thereby improving the dispersibility of the carbon nanotubes in the oil.

Specifically, the specific operation of step S4 is: transferring the reaction mixture to a constant temperature oven and keeping it at 80-100° C. for 12-14 hours; after cooling to room temperature, drying the reaction mixture in a vacuum drying oven for 24-30 hours to obtain carbon nanotubes modified with a silane coupling agent.

Specifically, in step S5, the mass ratio of carbon nanotubes modified with silane coupling agent to aniline is 1:6-100, and a magnetic stirrer is used to stir at room temperature to ensure that aniline and carbon nanotubes modified with silane coupling agent are fully mixed. Here, water is only used as a solvent or dispersion matrix, and will be removed later by drying and other steps. Therefore, the amount of water added can ensure its dispersion effect. The specific amount can be adjusted according to the actual situation and should not be too much or too little; the mixed solution is placed in an ice bath to cool, and the pre-dissolved ammonium persulfate solution is slowly added to start the polymerization reaction. The mass ratio of ammonium persulfate (here refers to the solute mass) to aniline is 0.05-0.1:1, the reaction time is 4-6 hours, and the reaction temperature is 0°C (ice bath).

The mass ratio of carbon nanotubes modified with silane coupling agent to aniline (1:6-100) is to ensure the full use of aniline so that it can undergo uniform polymerization reaction on the surface of carbon nanotubes. The carbon nanotubes serve as the core, and aniline polymerizes on their surface to form a polyaniline wrapping layer. If too much aniline is added, unreacted aniline may remain, which will affect the electrical properties and thermal stability of the composite material; if too little is added, it may not be enough to completely cover the carbon nanotubes, resulting in decreased conductivity and mechanical properties.

The mass ratio of ammonium persulfate to aniline is (0.05-0.1:1). As an initiator, the amount of ammonium persulfate should be appropriate to control the polymerization reaction rate and degree of polymerization of aniline. This ratio is to ensure the controllability of the reaction and the uniformity of the product. Too much ammonium persulfate may cause the polymerization reaction to be too fast, affecting the growth of the polyaniline chain and making the polyaniline distribution uneven; too little may lead to incomplete polymerization and reduce the performance of the product.

Controlling the reaction temperature (0°C) and conducting the reaction in an ice bath can greatly control the polymerization rate and slow down the reaction, thereby facilitating a more uniform polyaniline coating. The 0°C environment helps reduce side reactions and undesirable polymerization pathways. In a 0°C ice bath environment, the formation of polyaniline is a free radical polymerization reaction initiated by the initiator ammonium persulfate. Aniline molecules are first oxidized by ammonium persulfate to form free radicals, which then connect to form polyaniline chains. Low temperatures help control the reaction rate, reduce chain breaks and nonspecific reactions, and thus obtain a more uniform polyaniline layer.

Specifically, the solid and the liquid are separated by filtration, and the precipitate is washed with a large amount of distilled water to remove unreacted monomers and by-products; the washed carbon nanotubes (process state) are transferred to a vacuum drying oven and dried at 60-80° C. for not less than 24 hours to obtain polyaniline-coated carbon nanotubes.

It is worth noting that polyaniline has good electrical conductivity compared to other polymers, and both polyaniline and carbon nanotubes are rich in π electron systems. The continuous electron transport network formed by π-π stacking interactions can effectively improve the overall electrical conductivity of the material. Carbon nanotubes provide fast electron transport channels, and the conductivity of polyaniline further enhances these channels. This enhanced electron transport capability allows charges to be quickly conducted on the surface or in the body of the material, thereby effectively dissipating static electricity accumulation and reducing the generation and accumulation of static electricity. Furthermore, through π-π interactions, the polyaniline molecular chains form a uniform and continuous coating on the surface of carbon nanotubes, which can act as a physical barrier to prevent the oxidation of carbon nanotubes during processing or application.

Specifically, in step S6, the mass concentration of the sodium dodecylbenzene sulfonate aqueous solution is 1-1.2%, the volume ratio of the polyaniline-coated carbon nanotubes to the sodium dodecylbenzene sulfonate aqueous solution is 1:400-500, and the ultrasonic treatment time is ≥1h to obtain a well-dispersed carbon nanotube suspension; the mass ratio of the silicon dioxide powder to the polyaniline-coated carbon nanotubes is 8-15:1, the heating temperature is 80°C-100°C, and the reaction time is ≥3 hours, so that the silicon dioxide and the carbon nanotubes are more closely combined.

It is worth noting that silica has excellent thermal stability and can maintain its physical and chemical properties unchanged in high temperature environments, thus providing a stable base for the entire composite material. By introducing polyaniline-coated carbon nanotubes supported by silica carriers in spinning oils, the thermal stability of the fibers in processing and applications can be increased, especially in environments that require high temperature processing or operation. On the other hand, the surface roughness and pore structure of silica particles also help to physically embed or attach carbon nanotubes, reducing the sedimentation or aggregation of carbon nanotubes in the oil. Ensure that the processing quality and performance of each batch of fibers are consistent. This improved dispersibility helps the continuity and uniformity of the fibers during the production process and reduces the incidence of breakage and defects.

Specifically, in step S7, the semi-finished composite material product is dried in air.

Specifically, the specific operation of heat treatment in step S7 is to dry the semi-finished composite material in air, and then heat it to 500±100°C in a tubular furnace at a heating rate of 5±1°C/min, and the treatment time is 120-160min. Heat treatment can promote the physical and chemical bonding between different components in the composite material. For example, between polyaniline-coated carbon nanotubes and silicon dioxide, heat treatment can promote better bonding between silicon dioxide, carbon nanotubes and polyaniline, and enhance the overall structural stability of the composite material. Secondly, through the heating process, residual solvents and moisture in the composite material can be removed, further improving the thermal stability of the material. This is particularly important for materials used in high temperature environments, and can ensure that their performance in practical applications will not be reduced by high temperature. For composite materials containing conductive polymers (such as polyaniline) and carbon nanotubes, heat treatment can help form a more continuous and uniform conductive network and improve the overall conductivity of the material.

After cooling, the unreacted materials were removed by conventional screening and washing processes to obtain the final SiO ₂ -CNTs composite material.

The invention also discloses an antistatic agent, which is prepared by the preparation method.

The invention also discloses an oil agent for ultra-high molecular weight polyethylene fibers, wherein the oil agent comprises the antistatic agent.

Specifically, the oil agent is suitable for ultra-high molecular weight polyethylene fiber, including a smoothing agent, an emulsifier, an antistatic agent and a stabilizer; by weight, the smoothing agent is 50 to 70 parts, the emulsifier is 50 to 60 parts, the antistatic agent is 4 to 8 parts, and the stabilizer is 1 to 2 parts.

The role and content of each component are determined as follows:

Smoothing agent: Smoothing agent can reduce the friction coefficient of fibers in spinning, stretching, stretching, spinning and weaving processes, improve the strength of the oil film, and thus protect the fibers. Too little amount of smoothing agent will lead to insufficient lubricity on the fiber surface, which is easy to break during processing; too much amount may cause the fiber surface to be too smooth, affecting the bonding force between fibers. Experimental verification shows that when the amount of smoothing agent is 50-70 parts, the comprehensive performance of the oil agent is better.

Emulsifier: By reducing the interfacial tension between the oil and water phases, the two immiscible liquids form a stable emulsion (i.e., ensure the uniformity of the oil). Too little emulsifier will cause uneven distribution of the oil on the fiber surface, affecting the lubrication effect; too much may increase costs and may affect the mechanical properties of the fiber. Experimental verification shows that when the emulsifier is 50 to 60 parts, the comprehensive performance of the oil is better.

Antistatic agent: Too little antistatic agent cannot effectively reduce static electricity accumulation; too much antistatic agent may affect the mechanical properties and feel of the fiber. Experimental verification shows that when the antistatic agent is 4 to 8 parts, the overall performance of the oil is better.

Stabilizer: Stabilizer can improve the stability, high temperature resistance, sun resistance, storage resistance and dispersibility of the oil during high-speed processing. Too little stabilizer will cause the oil to fail during high temperature or long-term use, and too much will affect the oiling effect and comprehensive performance of the oil. Experimental verification shows that when the stabilizer is 1 to 2 parts, the comprehensive performance of the oil is better.

Synergistic effect: The use of antistatic agents in combination with smoothing agents and emulsifiers can effectively reduce static electricity problems without affecting the basic physical properties of the fiber, allowing the fiber to maintain good fluidity and handling properties during high-speed processing.

When the smoothing agent and the emulsifier are used in a proper proportion, an oil with both good lubricity and excellent dispersibility can be formed, which helps to provide a continuous and uniform lubricating protective layer in the spinning, weaving and other processes, reducing the risk of broken wires and fiber damage.

Furthermore, the lubricant is one or more of lauryl oleate, isooctyl oleate, isooctyl stearate, triolein, and mineral oil. The above substances have good lubricity, can increase the softness of the fiber, and have excellent lubricity and stability, can effectively reduce the friction between the fibers, and have certain anti-oxidation properties.

Furthermore, the emulsifier is one or more of cardanol polyoxyethylene ether, polyglycerol monofatty acid ester, and castor oil polyoxyethylene ether. The above substances have good emulsifying properties and chemical stability, are non-irritating to fibers, and have a certain lubricating effect.

Furthermore, the antistatic agent is the antistatic agent described in the present invention.

Furthermore, the stabilizer is one or more of acrylic acid polyether silicone oil, Tween 80, polyether modified silicone oil, and trifluoropropyl methyl silicone oil. These stabilizers have high chemical stability and can maintain their structure unchanged under various processing and use conditions, thereby ensuring the long-term effectiveness of the oil performance; these stabilizers can improve the lubricity and dispersibility of the oil, ensuring the smoothness and uniform coating of the fiber during the processing; these stabilizers can show good stability under different temperature and environmental conditions, especially in high-temperature and high-speed industrial applications, which helps to protect the performance of the fiber during processing and use.

Specifically, the oil agent has excellent antistatic properties. The ultra-high molecular weight polyethylene fiber treated with the oil agent has an electrostatic voltage of ≤0.041 kV, an initial modulus of ≥1900 cN/dtex, an initial breaking strength of ≥40.0 cN/dtex, and a small decrease in breaking strength under high temperature conditions. The fiber is placed in a 200°C oven for 72 hours and then taken out, and the breaking strength decreases by ≤9.2%.

The present invention also discloses a method for preparing the oil, and the specific steps are as follows:

S21: weigh the raw materials according to the preset formula, put the smoothing agent and the emulsifier into a stirring tank, and stir them evenly at room temperature;

S22: While continuing to stir, slowly add the antistatic agent to ensure that the antistatic agent is evenly dispersed throughout the mixture;

S23: Add stabilizer to the mixture and continue stirring for more than 30 minutes to ensure that all ingredients are fully blended to obtain a semi-finished oil preparation;

S24: adjusting the pH value and viscosity of the semi-finished oil, filtering and filling into a storage container, i.e., the finished oil.

Specifically, in step S21, the stirring speed is 800-1000 r/min. If the stirring speed is too slow, the mixing effect is poor, and if the speed is too fast, too much foam will be generated.

Specifically, the pH adjuster is potassium hydroxide or triethanolamine.

Specifically, the pH value ranges from 6 to 7, and the viscosity ranges from 100 mPa·s to 115 mPa·s.

Specifically, the viscosity of the mixture can be adjusted by adding a proper amount of distilled water or a suitable diluent (one or more of ethanol, acetone and water).

The present invention also discloses a method for using the oil agent (oiling method), which specifically comprises the following steps:

S31: preparing an ultra-high molecular weight polyethylene high viscosity solution;

S32: Extruding the high viscosity solution through a spinning nozzle with a spinneret aperture of 1 mm and an aspect ratio of 6 to 12 to form filaments at a spinning temperature of 250° C. to 280° C. to obtain ultra-high molecular weight polyethylene fibers;

S33: After the initial cooling, the fiber is immediately sent to the stretching machine for heat stretching; the stretching temperature is set at 120℃～140℃, and the stretching ratio is 5～10 times of the original length;

S34: The stretched fiber is oiled by a coating device, cooled and dried after oiling, and then rolled up on a reel to obtain a finished fiber product.

Exemplarily, a high-viscosity solution of ultra-high molecular weight polyethylene can be obtained by the following method: mixing UHMWPE powder with a solvent (one or more of p-xylene/decalin, tetralin, kerosene, liquid paraffin, and white oil) in a heated and stirred container, and fully heating to 130° C. to 160° C. to completely dissolve it to form a high-viscosity solution; the mass content of ultra-high molecular weight polyethylene is 15 to 18%.

Specifically, the coating equipment in step S34 is a dipping tank or a spray system, and the oiling speed is 20m/min to 30m/min to ensure that the fibers are evenly coated with the oiling agent.

Specifically, the cooling in step S34 can be air cooling or water bath cooling, and the cooling time is 10 to 20 seconds to stabilize the coating of the oil on the fiber surface.

Furthermore, generally speaking, the fiber product specification after winding is 5 to 10 kg/roll.

Source of raw materials for testing:

Ultra-high molecular weight polyethylene was purchased from Zhejiang Jiuding Chemical Materials Co., Ltd., brand: U-PE350-II, molecular weight of 3500000-8000000 g/mol, bulk density of 0.30-0.50 g/cm ³ .

Multi-walled carbon nanotubes were purchased from Xianfeng Nano, model number XFM22, with a purity of 95%, a length of 0.5 μm to 2 μm, and a diameter of 20 nm to 30 nm.

Silica was purchased from Aijiexu Chemical Technology (Shanghai) Co., Ltd., with an average particle size of 5-10 μm, a surface area of 800 m ² /g, and a pore volume of 3 cm ³ /g.

Aniline was purchased from Tokyo Chemical Industry Co., Ltd.

Example 1

Preparation of antistatic agent:

S1: weighing or measuring 1 part of carbon nanotubes and 100 parts of ethanol by weight, adding the carbon nanotubes into the ethanol and performing ultrasonic dispersion to obtain a carbon nanotube solution;

S2: According to the volume ratio, 1 part of KH-550 was measured and dissolved in 10 parts of ethanol, and 3 parts of distilled water were slowly added under stirring, and the pH value was adjusted to 4. The mixed solution was allowed to stand for 3 hours until the silane coupling agent was fully hydrolyzed to obtain a silane coupling agent solution;

S3: slowly adding the carbon nanotube solution into the silane coupling agent solution and stirring for 4 hours, and obtaining a reaction mixture after the reaction is completed; the mass ratio of the silane coupling agent to the carbon nanotube is 0.2:1.

S4: baking the reaction mixture, cooling it to room temperature and then vacuum drying it to obtain carbon nanotubes modified with a silane coupling agent.

S5: Ultrasonic dispersion of carbon nanotubes modified with silane coupling agent in aqueous solution and addition of aniline, stirring and mixing thoroughly; ice-cooling and addition of ammonium persulfate solution, stirring continued at 0°C for 5 hours, after the reaction was completed, filtering, washing and drying to obtain polyaniline-coated carbon nanotubes; the mass ratio of carbon nanotubes modified with silane coupling agent to aniline was 1:6, and aniline:ammonium persulfate = 1:0.05.

S6: Adding polyaniline-coated carbon nanotubes to an aqueous solution containing 1 wt.% sodium dodecylbenzene sulfonate at a mass ratio of 1:400, and obtaining a carbon nanotube suspension after ultrasonic treatment; slowly adding silica powder to the carbon nanotube suspension, stirring evenly, heating to 90°C and continuing stirring for 3 hours to obtain a composite material semi-finished product; the mass ratio of silica to polyaniline-coated carbon nanotubes is 8:1.

S7: drying the semi-finished composite material in air, and then heating it to 500±100°C in a tube furnace at a heating rate of 5±1°C/min for 120-160 min. After cooling, sieving and washing, a finished SiO ₂ -CNTs composite material, namely the antistatic agent, is obtained.

Oil configuration:

The preset formula is: by mass, 50 parts of lauryl oleate as a lubricant, 50 parts of cardanol polyoxyethylene ether as an emulsifier, 5 parts of an antistatic agent, and 1 part of acrylic acid polyether silicone oil as a stabilizer.

S21: weigh the raw materials according to the preset formula, put the smoothing agent and emulsifier into a stirring tank, and stir them evenly at room temperature at a stirring speed of 900 r/min;

S22: While continuing to stir, slowly add the antistatic agent to ensure that the antistatic agent is evenly dispersed throughout the mixture;

S23: Add stabilizer to the mixture and continue stirring for more than 30 minutes to ensure that all ingredients are fully blended to obtain a semi-finished oil preparation;

S24: The pH value of the semi-finished oil is adjusted to 6 and the viscosity is adjusted to 110 mPa·s, and the semi-finished oil is filtered and filled into a storage container, i.e., the finished oil.

Oiling process:

S31: preparing an ultra-high molecular weight polyethylene high viscosity solution;

The ultra-high molecular weight polyethylene high viscosity solution can be obtained by the following method: UHMWPE powder and white oil are mixed in a heated and stirred container, and fully heated to 130° C. to completely dissolve them to form a high viscosity solution; the content of ultra-high molecular weight polyethylene is 15wt.%.

S32: extruding the high viscosity solution through a spinning nozzle with a spinneret aperture of 1 mm and an aspect ratio of 6 to form filaments at a spinning temperature of 250° C. to obtain ultra-high molecular weight polyethylene fibers;

S33: After the initial cooling, the fiber is immediately sent to the stretching machine for thermal stretching; the stretching temperature is set at 120°C and the stretching ratio is 5 times the original length;

S34: The stretched fiber is oiled through a coating device at an oiling speed of 20 m/min. After oiling, the fiber is cooled and dried, and then rolled up on a reel to obtain a finished fiber product.

Example 2

Preparation of antistatic agent:

S1: weighing or measuring 1 part of carbon nanotubes and 120 parts of ethanol by weight, adding the carbon nanotubes into the ethanol and performing ultrasonic dispersion to obtain a carbon nanotube solution;

S2: According to the volume ratio, 1 part of KH-560 was measured and dissolved in 11 parts of ethanol, and 3.5 parts of distilled water were slowly added under stirring, and the pH value was adjusted to 4.5. The mixed solution was allowed to stand for 2.5 hours until the silane coupling agent was fully hydrolyzed to obtain a silane coupling agent solution;

S3: slowly adding the carbon nanotube solution into the silane coupling agent solution and stirring for 4.5 hours, and obtaining a reaction mixture after the reaction is completed; the mass ratio of the silane coupling agent to the carbon nanotube is 0.4:1.

S4: baking the reaction mixture, cooling it to room temperature and then vacuum drying it to obtain carbon nanotubes modified with a silane coupling agent.

S5: Ultrasonic dispersion of carbon nanotubes modified with silane coupling agent in aqueous solution and adding aniline, stirring and mixing thoroughly; cooling in an ice bath and adding ammonium persulfate solution, stirring is continued at 0°C for 4 hours, and after the reaction is completed, polyaniline-coated carbon nanotubes are obtained by filtering, washing and drying; the mass ratio of carbon nanotubes modified with silane coupling agent to aniline is 1:10, and aniline:ammonium persulfate = 1:0.1.

S6: Adding polyaniline-coated carbon nanotubes to an aqueous solution containing 1.1wt.% sodium dodecylbenzene sulfonate at a mass ratio of 1:500, and obtaining a carbon nanotube suspension after ultrasonic treatment; slowly adding silica powder to the carbon nanotube suspension, stirring evenly, heating to 85°C and continuing stirring for 3.5h to obtain a composite material semi-finished product; the mass ratio of silica to polyaniline-coated carbon nanotubes is 13:1.

S7: drying the semi-finished composite material in air, and then heating it to 500±100°C in a tube furnace at a heating rate of 5±1°C/min for 120-160 min. After cooling, sieving and washing, a finished SiO ₂ -CNTs composite material, namely the antistatic agent, is obtained.

Oil configuration:

The preset formula is: by mass, 70 parts of lubricant isooctyl oleate, 53 parts of emulsifier polyglycerol monofatty acid ester, 6 parts of antistatic agent, and 1.5 parts of stabilizer Tween 80.

The preparation method of the oil agent and the oiling method are the same as those in Example 1.

Example 3

Preparation of antistatic agent:

S1: weighing or measuring 1 part of carbon nanotubes and 110 parts of ethanol by weight, adding the carbon nanotubes into the ethanol and performing ultrasonic dispersion to obtain a carbon nanotube solution;

S2: According to the volume ratio, 1 part of KH-550 was measured and dissolved in 12 parts of ethanol, and 3 parts of distilled water were slowly added under stirring, and the pH value was adjusted to 5. The mixed solution was allowed to stand for 4 hours until the silane coupling agent was fully hydrolyzed to obtain a silane coupling agent solution;

S3: slowly adding the carbon nanotube solution into the silane coupling agent solution and stirring for 5 hours, and obtaining a reaction mixture after the reaction is completed; the mass ratio of the silane coupling agent to the carbon nanotube is 0.3:1.

S4: baking the reaction mixture, cooling it to room temperature and then vacuum drying it to obtain carbon nanotubes modified with a silane coupling agent.

S5: Ultrasonic dispersion of carbon nanotubes modified with silane coupling agent in aqueous solution and addition of aniline, stirring and mixing thoroughly; ice-cooling and addition of ammonium persulfate solution, stirring continued at 0°C for 4.5h, after the reaction was completed, filtration, washing and drying were performed to obtain polyaniline-coated carbon nanotubes; the mass ratio of carbon nanotubes modified with silane coupling agent to aniline was 1:8, and aniline:ammonium persulfate = 1:0.07.

S6: Adding polyaniline-coated carbon nanotubes to an aqueous solution containing 1.2wt.% sodium dodecylbenzenesulfonate at a mass ratio of 1:480, and obtaining a carbon nanotube suspension after ultrasonic treatment; slowly adding silica powder to the carbon nanotube suspension, stirring evenly, heating to 95°C and continuing stirring for 3h to obtain a composite material semi-finished product; the mass ratio of silica to polyaniline-coated carbon nanotubes is 10:1.

S7: drying the semi-finished composite material in air, and then heating it to 500±100°C in a tube furnace at a heating rate of 5±1°C/min for 120-160 min. After cooling, sieving and washing, a finished SiO ₂ -CNTs composite material, namely the antistatic agent, is obtained.

Oil configuration:

The preset formula is: by mass, 65 parts of lubricant isooctyl stearate, 60 parts of emulsifier castor oil polyoxyethylene ether, 8 parts of antistatic agent, and 1.8 parts of stabilizer polyether modified silicone oil.

The preparation method of the oil agent and the oiling method are the same as those in Example 1.

Example 4

Preparation of antistatic agent:

S1: weigh or measure 1 part of carbon nanotubes and 105 parts of ethanol by weight, add the carbon nanotubes into the ethanol and perform ultrasonic dispersion to obtain a carbon nanotube solution;

S2: According to the volume ratio, 1 part of KH-560 was measured and dissolved in 10 parts of ethanol, and 3.5 parts of distilled water were slowly added under stirring, and the pH value was adjusted to 4.5. The mixed solution was allowed to stand for 3 hours until the silane coupling agent was fully hydrolyzed to obtain a silane coupling agent solution;

S3: slowly adding the carbon nanotube solution into the silane coupling agent solution and stirring for 4 hours, and obtaining a reaction mixture after the reaction is completed; the mass ratio of the silane coupling agent to the carbon nanotube is 0.25:1.

S4: baking the reaction mixture, cooling it to room temperature and then vacuum drying it to obtain carbon nanotubes modified with a silane coupling agent.

S5: Ultrasonic dispersion of carbon nanotubes modified with silane coupling agent in aqueous solution and adding aniline, stirring and mixing thoroughly; cooling in an ice bath and adding ammonium persulfate solution, stirring is continued at 0°C for 6 hours, and after the reaction is completed, polyaniline-coated carbon nanotubes are obtained by filtering, washing and drying; the mass ratio of carbon nanotubes modified with silane coupling agent to aniline is 1:7, and aniline:ammonium persulfate = 1:0.09.

S6: Adding polyaniline-coated carbon nanotubes to an aqueous solution containing 1 wt.% sodium dodecylbenzene sulfonate at a mass ratio of 1:430, and obtaining a carbon nanotube suspension after ultrasonic treatment; slowly adding silica powder to the carbon nanotube suspension, stirring evenly, heating to 80°C and continuing stirring for 3.5 hours to obtain a composite material semi-finished product; the mass ratio of silica to polyaniline-coated carbon nanotubes is 15:1.

S7: drying the semi-finished composite material in air, and then heating it to 500±100°C in a tube furnace at a heating rate of 5±1°C/min for 120-160 min. After cooling, sieving and washing, a finished SiO ₂ -CNTs composite material, namely the antistatic agent, is obtained.

Oil configuration:

The preset formula is: by mass, 55 parts of smoothing agent glyceryl trioleate, 23 parts of emulsifier cardanol polyoxyethylene ether + 34 parts of polyglycerol monofatty acid ester, 4 parts of antistatic agent, and 2 parts of stabilizer trifluoropropyl methyl silicone oil.

The preparation method of the oil agent and the oiling method are the same as those in Example 1.

Comparative Example 1

Compared with Example 4, the carbon nanotubes are not modified with a silane coupling agent (no steps S2 and S3), and the other process conditions and operations are the same.

Comparative Example 2

Compared with Example 4, polyethylene glycol is used instead of polyaniline to coat the carbon nanotubes, and the other process conditions and operations are the same.

Comparative Example 3

Compared with Example 4, the process of loading carbon nanotubes with silicon dioxide is omitted (no step S6), and the other process conditions and operations are the same.

Performance testing:

Test standards for breaking strength and initial modulus of ultra-high molecular weight polyethylene fiber: refer to GB/T19975-2005 high-strength fiber filament tensile performance test method. Static voltage is measured using Keyence SK-H static meter. High temperature resistance test: put the fiber into a 200℃ oven for 72 hours and then take it out to test its breaking strength. The test results are shown in Table 1.

Table 1 Ultra-high molecular weight polyethylene fiber properties

It can be seen from the above table that in Comparative Example 1, since the carbon nanotubes were not modified with a silane coupling agent, the carbon nanotubes aggregated and piled up, the antistatic performance decreased, the static voltage increased, and the lack of the reinforcing effect of the carbon nanotubes caused the initial modulus and breaking strength to decrease.

Since comparative example 2 uses polyethylene glycol instead of polyaniline, the synergistic conductive effect of polyaniline and carbon nanotubes cannot be exerted, so the antistatic performance is reduced and the static voltage is increased.

In Comparative Example 3, since silicon dioxide was omitted as a carrier, polyaniline-coated carbon nanotubes were directly added to the oil. Due to the lack of silicon dioxide, the thermal stability of the fiber decreased, and the breaking strength decreased significantly after high-temperature treatment. At the same time, the dispersion uniformity of the carbon nanotubes decreased, and the carbon nanotubes were easy to settle and aggregate in the oil, resulting in a decrease in the fiber breaking strength.

In summary, the ultra-high molecular weight polyethylene fiber treated with the oil agent (including the electrostatic agent provided by the present invention) has an electrostatic voltage of ≤0.041 kV, an initial modulus ≥1900 cN/dtex, an initial breaking strength ≥40.0 cN/dtex, and a small decrease in breaking strength under high temperature conditions; the fiber is placed in a 200°C oven for 72 hours and then taken out, and the breaking strength decreases by ≤9.2%.

The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims (8)

1. A preparation method of an antistatic agent is characterized by comprising the steps of firstly modifying carbon nanotubes by using a silane coupling agent, forming covalent bonds between siloxane groups and functional groups on the surfaces of the carbon nanotubes through condensation reaction so as to anchor the functional groups on the surfaces of the carbon nanotubes, providing enough steric hindrance by introducing a flexible chain segment, avoiding direct contact between the carbon nanotubes and the action of Van der Waals force, and enabling the modified carbon nanotubes not to be easily aggregated or re-aggregated so as to enable the modified carbon nanotubes to be more easily interacted with organic molecules in an oiling agent, thereby improving the dispersibility of the carbon nanotubes in the oiling agent;

The polyaniline is used for coating the modified carbon nano tube, the polyaniline has good conductivity, and the carbon nano tube is rich in pi electron systems, a continuous electron transport network formed by pi-pi stacking interaction can effectively improve the overall conductivity of the material, the carbon nano tube provides rapid electron transport channels, the conductivity of the polyaniline further enhances the channels, the enhanced electron transport capability enables charges to be rapidly conducted on the surface or in the body of the material, thereby effectively dissipating static electricity accumulation and reducing the generation and accumulation of static electricity, and a uniform and continuous coating layer is formed on the surface of the carbon nano tube by pi-pi interaction through polyaniline molecular chains to serve as a physical barrier to prevent the oxidation of the carbon nano tube in the treatment or application process;

Finally, loading the polyaniline-coated modified carbon nano tube on a silicon dioxide carrier to obtain a finished product of the SiO ₂ -CNTs composite material, namely the antistatic agent, wherein the silicon dioxide has excellent thermal stability, and can keep the physical and chemical properties unchanged in a high-temperature environment, so that a stable substrate is provided for the whole composite material;

The preparation method specifically comprises the following steps:

s1, weighing or measuring carbon nanotubes and ethanol, adding the carbon nanotubes into the ethanol, and performing ultrasonic dispersion to obtain a carbon nanotube solution;

S2, measuring a silane coupling agent, dissolving the silane coupling agent in ethanol, slowly adding distilled water under the stirring condition, adjusting the pH value, standing the mixed solution, and obtaining a silane coupling agent solution after the silane coupling agent is fully hydrolyzed;

S3, slowly adding the carbon nano tube solution into the silane coupling agent solution, stirring, and obtaining a reaction mixture after the reaction is completed;

S4, baking the reaction mixture, cooling to room temperature, and then performing vacuum drying to obtain the carbon nanotube modified by the silane coupling agent;

S5, ultrasonically dispersing the carbon nano tube modified by the silane coupling agent in an aqueous solution, adding aniline, stirring and fully mixing, cooling in an ice bath, adding an ammonium persulfate solution, continuously stirring at 0 ℃, and filtering, washing and drying after the reaction is completed to obtain the polyaniline-coated carbon nano tube;

s6, adding polyaniline-coated carbon nanotubes into an aqueous solution containing sodium dodecyl benzene sulfonate, and performing ultrasonic treatment to obtain a carbon nanotube suspension;

S7, drying and heat-treating the semi-finished product of the composite material, and screening and washing after cooling to obtain a finished product of the SiO ₂ -CNTs composite material, namely the antistatic agent;

And S7, the heat treatment is specifically carried out, namely, the semi-finished product of the composite material is dried in the air, and then is heated to 500+/-100 ℃ in a tube furnace at a temperature rising rate of 5+/-1 ℃ per minute, and the treatment time is 120-160 minutes.

2. The preparation method of the aqueous solution of the silane coupling agent is characterized in that in the step S2, the volume ratio of the silane coupling agent to ethanol is 1:10-12, the volume ratio of the silane coupling agent to distilled water is 1:3-3.5, the pH value adjustment interval is 4-5, the standing time is more than or equal to 2 hours, and the silane coupling agent is KH-550 or KH-560.

3. The preparation method of claim 1, wherein in the step S3, the mass ratio of the silane coupling agent solution to the carbon nanotube solution is 0.2-0.4:1, and the stirring time is more than or equal to 4 hours.

4. The preparation method according to claim 1, wherein the specific operation of the step S4 is that the reaction mixture is transferred into a constant temperature oven, kept at 80-100 ℃ for 12-14 hours, cooled to room temperature, and dried in a vacuum drying oven for 24-30 hours to obtain the carbon nanotube modified by the silane coupling agent.

5. The preparation method of the catalyst according to claim 1, wherein the mass ratio of the carbon nanotubes modified by the silane coupling agent to the aniline in the step S5 is 1:6-10, the mass ratio of ammonium persulfate to the aniline is 0.05-0.1:1, and the reaction time is 4-6 hours.

6. The preparation method of the polyaniline-coated carbon nanotube composite material according to claim 1, wherein in the step S6, the mass concentration of the sodium dodecyl benzene sulfonate aqueous solution is 1-1.2%, the volume ratio of the polyaniline-coated carbon nanotubes to the sodium dodecyl benzene sulfonate aqueous solution is 1:400-500, the mass ratio of the silicon dioxide powder to the polyaniline-coated carbon nanotubes is 8-15:1, the heating temperature is 80-100 ℃, and the reaction time is more than or equal to 3 hours.

7. An antistatic agent, characterized in that it is produced by the production method according to any one of claims 1 to 6.

8. An oil for ultra-high molecular weight polyethylene fibers, characterized in that the oil comprises the antistatic agent according to claim 7.