CN119307012A

CN119307012A - Antistatic agent and preparation method and application thereof

Info

Publication number: CN119307012A
Application number: CN202411586301.7A
Authority: CN
Inventors: 韦甜
Original assignee: Jiangsu New Vision Advanced Functional Fiber Innovation Center Co ltd
Current assignee: Jiangsu New Vision Advanced Functional Fiber Innovation Center Co ltd
Priority date: 2024-11-08
Filing date: 2024-11-08
Publication date: 2025-01-14
Anticipated expiration: 2044-11-08
Also published as: CN119307012B

Abstract

The invention relates to an antistatic agent and a preparation method and application thereof, belongs to the technical field of plastic additives, and solves at least one of the problems of poor dispersibility, insufficient conductivity, easiness in oxidization, insufficient thermal stability and uniformity, easiness in aggregation or sedimentation and the like of the existing antistatic agent. The preparation method of the antistatic agent comprises the steps of silane coupling agent modification, polyaniline coating, silica loading and the like, and the novel SiO ₂ -CNTs composite material is obtained. The antistatic agent has good dispersibility, excellent conductivity, good thermal stability and uniformity, and the oiling agent prepared by the antistatic agent is used for treating the ultra-high molecular weight polyethylene fiber, so that the continuity and uniformity of the fiber in the production process are improved, the occurrence rate of breakage and defects is reduced, 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, in particular to an antistatic agent and a preparation method and application thereof.

Background

Ultra High Molecular Weight Polyethylene (UHMWPE) fibers are widely used in various fields such as body armor, cut-resistant gloves, ropes, fishing nets, medical devices, etc., due to their excellent mechanical properties. UHMWPE fibers have extremely high strength, excellent wear resistance, low friction coefficient and good impact resistance, however, such fibers have some significant drawbacks in practical use, mainly including poor heat resistance and poor antistatic properties.

The melting point of UHMWPE fibers is low, on the order of 130 ℃, well below that of other high performance fibers such as aramid fibers. Under high temperature conditions, UHMWPE fibers are susceptible to deformation and degradation, resulting in a significant decrease in their mechanical properties. For example, in industrial high temperature environmental applications, the heat resistance of a material directly affects its service life and safety. Furthermore, the heat treatment processes involved in the textile processing, such as heat setting and ironing, can also adversely affect the UHMWPE fibres, limiting their use in these fields.

UHMWPE fibers have poor antistatic properties, mainly due to their extremely low electrical conductivity, and are prone to build up of static electricity during use. The accumulation of static electricity not only affects the processability of the fiber, such as dust and impurities easily adsorbed during spinning, weaving and finishing, resulting in degradation of product quality, but also causes fire or explosion in some specific environments, such as flammable and explosive environments, resulting in serious safety hazards.

Currently, some modification methods and treatment techniques are available on the market for the problems of poor heat resistance and poor antistatic properties of UHMWPE fibers. For example, the heat resistance of the fiber is improved by coating the surface of the fiber with a high temperature resistant material, or an antistatic agent is added to improve the antistatic property. However, the existing antistatic agent has the problems of poor dispersibility, insufficient conductivity, easiness in oxidation, insufficient thermal stability and uniformity, easiness in aggregation or sedimentation and the like, so that the treated ultrahigh molecular weight polyethylene (UHMWPE) fiber has poor thermal stability, easiness in breakage and high static pressure.

Therefore, development of an antistatic agent excellent in dispersibility, conductivity and thermal stability and a dedicated oil for ultra-high molecular weight polyethylene (UHMWPE) fiber, which is used as a material, is required.

Disclosure of Invention

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

The invention provides a preparation method of an antistatic agent, which comprises the steps of firstly modifying a carbon nano tube by using a silane coupling agent, then coating the modified carbon nano tube by using polyaniline, and finally loading the polyaniline-coated modified carbon nano tube on a silicon dioxide carrier to obtain a SiO ₂ -CNTs composite material finished product, namely the antistatic agent.

The method comprises the following specific 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;

and 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 SiO2-CNTs composite material, namely the antistatic agent.

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

Specifically, in the step S2, the volume ratio of the silane coupling agent to the ethanol is 1:10-12, the volume ratio of the silane coupling agent to the 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.

Specifically, 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.

The preparation method comprises the specific operation of step S4, namely transferring the reaction mixture into a constant temperature oven, preserving heat for 12-14 hours at the temperature of 80-100 ℃, cooling to room temperature, and drying the reaction mixture in a vacuum drying oven for 24-30 hours to obtain the carbon nanotube modified by the silane coupling agent.

Specifically, in the step S5, the mass ratio of the carbon nano tube modified by the silane coupling agent to the aniline 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.

Specifically, 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 nano tube 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 nano tube is 8-15:1, the heating temperature is 80-100 ℃, and the reaction time is more than or equal to 3 hours.

Specifically, the specific operation of the heat treatment in the step S7 is that 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.

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

The invention also discloses an oiling agent for the ultra-high molecular weight polyethylene fiber, which comprises the antistatic agent.

Compared with the prior art, the invention has at least one of the following beneficial effects:

1. The antistatic agent provided by the invention has good antistatic performance and excellent dispersibility, conductivity, oxidation resistance and thermal stability, the static voltage of the ultra-high molecular weight polyethylene fiber treated by the oiling agent containing the antistatic agent is less than or equal to 0.041kV, the initial modulus is more than or equal to 1900cN/dtex, the initial breaking strength is more than or equal to 40.0cN/dtex, and the breaking strength drop under the high-temperature condition is small.

The invention adopts the carbon nano tube as the main matrix of the antistatic agent, and the carbon nano tube has good heat conduction and electric conduction properties, so the antistatic agent can be used as a good heat conduction and antistatic material. However, carbon nanotubes are mainly hydrophobic on the surface due to their unique carbon structure, which makes their dispersibility in oils (organic solvents) poor. The invention adopts the silane coupling agent to modify the carbon nano tube, and the siloxane group can form covalent bonds with functional groups (such as carboxyl, hydroxyl and the like) on the surface of the carbon nano tube through condensation reaction, so that the carbon nano tube is anchored on the surface of the carbon nano tube. By introducing the soft segment, sufficient steric hindrance is provided, avoiding direct contact between carbon nanotubes and the effects of van der Waals forces. The modified carbon nano tube is not easy to aggregate or re-aggregate, so that the modified carbon nano tube is easier to interact with organic molecules in the oiling agent, and the dispersibility of the carbon nano tube in the oiling agent is improved.

Polyaniline has good conductivity relative to other macromolecules, and the carbon nano tube is rich in pi electron systems, and the continuous electron transport network formed by pi-pi stacking interaction can effectively improve the overall conductivity of the material. Carbon nanotubes provide fast electron transport channels, while the conductivity of polyaniline further enhances these channels. This enhanced electron transport capability enables charge to be rapidly conducted on or in the material surface, thereby effectively dissipating static charge buildup and reducing static charge generation and accumulation. Further, by pi-pi interaction, polyaniline molecular chains form a uniform and continuous coating layer on the surface of the carbon nanotube, which can serve as a physical barrier to prevent oxidation of the carbon nanotube during processing or application.

Silica has excellent thermal stability and can maintain its physical and chemical properties unchanged in high temperature environment, thus providing a stable substrate for the whole composite material. By introducing polyaniline-coated carbon nanotubes supported on a silica carrier into the spin finish, the thermal stability of the fiber in handling and application can be increased, particularly in environments where high temperature treatment or handling is required, avoiding loss or decomposition of antistatic agents under high temperature conditions and thus failure. On the other hand, the surface roughness and pore structure of the silica gel particles also help to physically embed or attach the carbon nanotubes, and reduce sedimentation or aggregation of the carbon nanotubes in the oil. Ensuring that the quality and performance of the treatment of each batch of fibres remains consistent. This improved dispersibility aids in the continuity and uniformity of the fibers during production, reducing the incidence of breakage and defects.

The static voltage of the ultra-high molecular weight polyethylene fiber treated by the oiling agent is less than or equal to 0.041kV, the initial modulus is more than or equal to 1900cN/dtex, the initial breaking strength is more than or equal to 40.0cN/dtex, and the breaking strength drop under the high-temperature condition is small.

2. When the preparation of the antistatic agent is carried out by adopting the preferable technological parameters of the invention, the uniformity and stability of the antistatic agent product can be improved, including but not limited to the full modification of the silane coupling agent, the uniformity and proper thickness of polyaniline coating, the loading effect of the silicon dioxide carrier and the like.

3. The antistatic agent and the oiling agent provided by the invention are easy to obtain, can be directly purchased from raw materials and equipment, are relatively simple in preparation process, mild in technological conditions and low in preparation difficulty, can be oiled by adopting the existing oiling process, and are suitable for large-scale production and wide application.

In the invention, the technical schemes can be mutually combined to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, like reference numerals being used to refer to like parts throughout the several views.

FIG. 1 is a photograph of an oil for ultra high molecular weight polyethylene fiber in example 1;

FIG. 2 is a flow chart of antistatic agent preparation.

Detailed Description

The following detailed description of preferred embodiments of the invention is made in connection with the accompanying drawings, which form a part hereof, and together with the description of the embodiments of the invention, are used to explain the principles of the invention and are not intended to limit the scope of the invention.

The method specifically comprises the following steps:

And 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.

Specifically, the main purpose of step S1 is to pretreat the carbon nanotubes, add the carbon nanotubes into ethanol, and ultrasonically disperse the carbon nanotubes for more than 30 minutes by using an ultrasonic processor, so that impurities and aggregates on the surfaces of the carbon nanotubes can be effectively removed.

Specifically, in the step S1, the mass ratio of the carbon nanotubes to the ethanol is 1:100-120, the adding amount of the carbon nanotubes is excessive, the impurity removing effect is poor, the adding amount of the carbon nanotubes is too small, and the preparation/production efficiency is reduced.

Specifically, in the step S2, the volume ratio of the silane coupling agent to the ethanol is 1:10-12, the volume ratio of the silane coupling agent to the 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. The hydrolysis reaction of silane coupling agents (e.g., KH-550 or KH-560) in water is significantly affected by the pH. Under neutral or slightly acidic conditions, the hydrolysis rate of the coupling agents is moderate, which is beneficial to controlling the reaction progress and the product quality. If the pH is too high (slightly alkaline), the silane coupling agent may hydrolyze too quickly, resulting in unstable products, and if the pH 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 react more effectively with the functional groups (e.g., carboxyl groups, hydroxyl groups, etc.) on the surface of the carbon nanotubes. The coupling effect can promote interface compatibility, so that the modified carbon nano tube is better dispersed in the final composite material. Under the specified pH value and standing time (at least 2 hours), preferably 2-6 hours, the silane coupling agent can be ensured to be fully hydrolyzed without excessive polymerization, subsequent processing and application are facilitated, and the full hydrolysis is a premise of ensuring that the coupling agent can effectively act on the carbon nano tube and other matrix materials.

Specifically, the pH regulator is potassium hydroxide or triethanolamine.

Specifically, 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, so that the sufficient contact and reaction between the carbon nanotubes and the coupling agent are ensured. The siloxane group can form covalent bond with the functional group (such as carboxyl and hydroxyl) on the surface of the carbon nano tube through condensation reaction, so that the siloxane group is anchored on the surface of the carbon nano tube. By introducing the soft segment, sufficient steric hindrance is provided, avoiding direct contact between carbon nanotubes and the effects of van der Waals forces. The modified carbon nano tube is not easy to aggregate or re-aggregate, so that the modified carbon nano tube is easier to interact with organic molecules in the oiling agent, and the dispersibility of the carbon nano tube in the oiling agent is improved.

Specifically, in the step S5, the mass ratio of the carbon nanotube modified by the silane coupling agent to the aniline is 1:6-100, the magnetic stirrer is used for stirring at room temperature, the sufficient mixing of the aniline and the carbon nanotube modified by the silane coupling agent is ensured, water is only used as a solvent or a dispersion matrix, and is removed through links such as drying, so that the water addition can ensure the dispersion effect, the specific dosage can be regulated according to practical conditions, the excessive or the insufficient dosage is not suitable, the mixed solution is placed in an ice bath for cooling, the pre-dissolved ammonium persulfate solution is slowly added, the polymerization reaction is started, the mass ratio of the ammonium persulfate (here, the solute mass) to the aniline is 0.05-0.1:1, the reaction time is 4-6 hours, and the reaction temperature is 0 ℃ in an ice bath.

The mass ratio (1:6-100) of the carbon nano tube modified by the silane coupling agent to the aniline is in order to ensure the full use of the aniline, so that the aniline can be subjected to uniform polymerization reaction on the surface of the carbon nano tube. The carbon nanotube is used as a core, and the polyaniline is polymerized on the surface of the carbon nanotube to form a polyaniline coating. If the aniline is added too much, unreacted aniline may remain, which affects the electrical and thermal stability of the composite material, and if it is added too little, it may be insufficient to completely cover the carbon nanotubes, resulting in a decrease in electrical conductivity and mechanical properties.

The mass ratio of ammonium persulfate to aniline (0.05-0.1:1), the ammonium persulfate is used as an initiator, and the polymerization rate and the polymerization degree of aniline are properly controlled, so that the controllability of the reaction and the uniformity of products are ensured. Too much ammonium persulfate may cause too fast polymerization reaction to affect the growth of polyaniline chains, so that polyaniline is unevenly distributed, and too little ammonium persulfate may cause incomplete polymerization reaction to reduce the performance of the product.

The reaction temperature is controlled (0 ℃) and the reaction in an ice bath can greatly control the polymerization rate and slow down the reaction, thereby being beneficial to obtaining a more uniform polyaniline coating. The 0 ℃ environment helps to reduce side reactions and unwanted polymerization pathways. In an ice bath environment at 0 ℃, polyaniline is formed as a free radical polymerization initiated by the initiator ammonium persulfate. The aniline molecules are first oxidized by ammonium persulfate to form free radicals, which are then linked to form polyaniline chains. The low temperature helps control the reaction rate, reducing chain scission and nonspecific reactions, resulting in a more uniform polyaniline layer.

Specifically, solid and liquid are separated by filtration, a large amount of distilled water is used for washing precipitate to remove unreacted monomers and byproducts, the washed carbon nano tube (in the process state) is transferred into a vacuum drying oven, and the carbon nano tube is dried for at least 24 hours at 60-80 ℃ to obtain the polyaniline-coated carbon nano tube.

It is worth noting that polyaniline has good conductivity compared with other polymers, and carbon nanotubes are rich in pi electron systems, and the continuous electron transport network formed by pi-pi stacking interaction can effectively improve the overall conductivity of the material. Carbon nanotubes provide fast electron transport channels, while the conductivity of polyaniline further enhances these channels. This enhanced electron transport capability enables charge to be rapidly conducted on or in the material surface, thereby effectively dissipating static charge buildup and reducing static charge generation and accumulation. Further, by pi-pi interaction, polyaniline molecular chains form a uniform and continuous coating layer on the surface of the carbon nanotube, which can serve as a physical barrier to prevent oxidation of the carbon nanotube during processing or application.

Specifically, 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 ultrasonic treatment time is more than or equal to 1h, so as 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 80-100 ℃, and the reaction time is more than or equal to 3 hours, so that the silicon dioxide and the carbon nanotubes are more tightly combined.

It is worth noting that silica has excellent thermal stability, and can maintain its physical and chemical properties unchanged in high temperature environment, thus providing a stable substrate for the whole composite material. By incorporating polyaniline-coated carbon nanotubes supported on a silica carrier in the spin finish, the thermal stability of the fiber in handling and application, particularly in environments where high temperature treatment or handling is required, can be increased. On the other hand, the surface roughness and pore structure of the silica gel particles also help to physically embed or attach the carbon nanotubes, and reduce sedimentation or aggregation of the carbon nanotubes in the oil. Ensuring that the quality and performance of the treatment of each batch of fibres remains consistent. This improved dispersibility aids in the continuity and uniformity of the fibers during production, reducing the incidence of breakage and defects.

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

Specifically, the specific operation of the heat treatment in the step S7 is that 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. The heat treatment may promote physical and chemical bonding between the different components in the composite. For example, the heat treatment between the polyaniline-coated carbon nanotubes and the silica can promote better bonding between the silica and the carbon nanotubes and between the polyaniline, enhancing the overall structural stability of the composite. And then, through a heating process, residual solvent and moisture in the composite material can be removed, so that the thermal stability of the material is further improved. This is particularly important for materials used in high temperature environments, ensuring that their performance in practical applications is not degraded by the high temperatures. For composite materials containing conductive polymers (e.g., polyaniline) and carbon nanotubes, heat treatment can help form a more continuous and uniform conductive network, improving the overall conductivity of the material.

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

The oiling agent is suitable for ultra-high molecular weight polyethylene fibers and comprises, by mass, 50-70 parts of a smoothing agent, 50-60 parts of an emulsifying agent, 4-8 parts of an antistatic agent and 1-2 parts of a stabilizing agent.

The functions and the content of each component are determined according to the following steps:

The smoothing agent can reduce the friction coefficient of the fiber in the processes of spinning, stretching, texturing, spinning, weaving and the like, and improve the oil film strength, thereby protecting the fiber. Too little amount of the smoothing agent can cause insufficient lubricity of the fiber surface and is easy to break in the processing process, and too much amount of the smoothing agent can cause too smooth of the fiber surface and affect the bonding force among the fibers. Experiments prove that the oil agent has better comprehensive performance when the smoothing agent is 50-70 parts.

And the emulsifier is used for enabling the two immiscible liquids to form stable emulsion (namely ensuring the uniformity of the oil agent) by reducing the interfacial tension between the oil phase and the water phase. Too little amount of emulsifier can cause uneven distribution of the oil agent on the surface of the fiber, affecting the lubrication effect, and too much amount can increase the cost and possibly affect the mechanical properties of the fiber. Experiments prove that the oil agent has better comprehensive performance when 50-60 parts of the emulsifier are used.

Antistatic agents, too little of which can not effectively reduce static buildup, and too much of which can affect the mechanical properties and hand feel of the fiber. Experiments prove that the oil solution has better comprehensive performance when the antistatic agent is 4-8 parts.

Stabilizers the stabilizers can improve the stability, high temperature resistance, sun resistance, shelf life and dispersibility during high speed processing of the oil. Too little stabilizer can lead to failure of the oil agent in the high-temperature or long-term use process, and too much stabilizer can influence the oiling effect and the comprehensive performance of the oil agent. Experiments prove that the oil agent has better comprehensive performance when the stabilizer is 1-2 parts.

The synergistic effect is that the cooperation of the antistatic agent, the smoothing agent and the emulsifying agent can effectively reduce the static problem while not affecting the basic physical properties of the fiber, so that the fiber maintains good fluidity and handling property in the high-speed processing process.

When the smoothing agent and the emulsifying agent are used in a proper ratio, an oil agent having both good lubricity and excellent dispersibility can be formed, which helps to provide a continuous and uniform lubrication protection layer in spinning, weaving and the like processes, reducing the risk of yarn breakage and fiber damage.

Further, the smoothing agent is one or more of lauryl oleate, isooctyl stearate, triolein and mineral oil. The material has good lubricity, can increase the softness of the fibers, has excellent lubricity and stability, can effectively reduce friction among the fibers, and has certain oxidation resistance.

Further, the emulsifier is one or more of cardanol polyoxyethylene ether, polyglycerol fatty acid ester and castor oil polyoxyethylene ether. The above materials have good emulsifying property and chemical stability, no irritation to fiber, and certain lubricating effect.

Further, the antistatic agent is selected from the antistatic agents.

Further, the stabilizer is one or more of polyether silicone oil of allyl acid, tween 80, polyether modified silicone oil and trifluoropropyl methyl silicone oil. The stabilizers have higher chemical stability, can keep the structure unchanged under various processing and using conditions, thereby ensuring the long-term effective performance of the oiling agent, can improve the lubricity and the dispersity of the oiling agent, ensure the smoothness and uniform coating of the fiber in the processing process, can show good stability under different temperature and environmental conditions, and are particularly beneficial to protecting the performance of the fiber in the processing and using processes in high-temperature and high-speed industrial application.

Specifically, the oiling agent has excellent antistatic performance, the static voltage of the ultra-high molecular weight polyethylene fiber treated by the oiling agent is less than or equal to 0.041kV, the initial modulus is more than or equal to 1900cN/dtex, the initial breaking strength is more than or equal to 40.0cN/dtex, the breaking strength drop under the high-temperature condition is small, the fiber is taken out after being put into a 200 ℃ oven for 72 hours, and the breaking strength drop is less than or equal to 9.2%.

The invention also discloses a preparation method of the oiling agent, which comprises the following specific steps:

s21, weighing raw materials according to a preset formula, putting a smoothing agent and an emulsifying agent into a stirring tank, and uniformly stirring at room temperature;

s22, slowly adding the antistatic agent while continuing stirring to ensure that the antistatic agent is uniformly dispersed in the whole mixture;

S23, adding a stabilizer into the mixture, and continuously stirring for more than 30 minutes to ensure that all components are fully fused to obtain an oiling agent semi-finished product;

and S24, regulating the pH value and the viscosity of the semi-finished oil product, filtering and filling the semi-finished oil product into a storage container to obtain the finished oil product.

Specifically, in the step S21, the stirring speed is 800-1000 r/min, the mixing effect is poor due to the too slow stirring speed, and excessive foam can be generated due to the too fast stirring speed.

Specifically, the pH regulator is potassium hydroxide or triethanolamine.

Specifically, the pH value is in the range of 6-7, and the viscosity is in the range of 100 mPas-115 mPas.

Specifically, the viscosity of the mixture may be adjusted by adding an appropriate amount of distilled water or an appropriate diluent (one or more of ethanol, acetone, and water).

The invention also discloses a using method (oiling method) of the oiling agent, which comprises the following steps:

s31, preparing an ultrahigh molecular weight polyethylene high-viscosity solution;

s32, extruding the high-viscosity solution through a spinning nozzle, wherein the spinning aperture is 1mm, the length-diameter ratio is 6-12, filaments are formed, and the spinning temperature is 250-280 ℃, so that the ultra-high molecular weight polyethylene fiber is obtained;

s33, immediately feeding the fiber into an extender for thermal extension after primary cooling, wherein the extension temperature is set to be 120-140 ℃, and the extension proportion is 5-10 times of the original length;

And S34, oiling the extended fiber through coating equipment, cooling and drying the fiber after oiling, and winding the fiber on a winding drum to obtain a fiber finished product.

The ultra-high molecular weight polyethylene high-viscosity solution is obtained by mixing UHMWPE powder with a solvent (one or more of paraxylene/decalin, tetralin, kerosene, liquid paraffin and white oil) in a heating and stirring container, and heating to 130-160 ℃ to completely dissolve the UHMWPE powder to form the high-viscosity solution, wherein the mass content of the ultra-high molecular weight polyethylene is 15-18%.

Specifically, in step S34, the coating device is a dip-coating tank or a spraying system, and the oiling speed is 20 m/min-30 m/min, so as to ensure that the fibers are uniformly coated with the oiling agent.

Specifically, in the cooling in step S34, air cooling or water bath cooling may be adopted, and the cooling time is 10-20S, so as to stabilize the coating of the oil agent on the fiber surface.

Further, the specification of the fiber product after winding is generally 5-10 kg/roll.

Description of sources of raw materials for testing:

The ultra-high molecular weight polyethylene is purchased from Zhejiang Jiding chemical materials Co., ltd, and has the brand of U-PE350-II, the molecular weight of 3500000-8000000g/mol and the bulk density of 0.30-0.50 g/cm ³.

The multi-wall carbon nano tube is purchased from Qianfeng nano, the model is XFM22, the purity is 95%, the length is 0.5-2 mu m, and the diameter is 20-30 nm.

The silica was purchased from Ai Jiexu chemical technology (Shanghai) Co., ltd, and had an average particle size of 5-10 μm, a surface area of 800m ²/g and a pore volume of 3cm ³/g.

Aniline was purchased from taifei (Shanghai) chemical industry development limited.

Example 1

Preparation of antistatic agent:

S1, weighing or measuring 1 part of carbon nano tube and 100 parts of ethanol according to the weight components, adding the carbon nano tube into the ethanol, and performing ultrasonic dispersion to obtain a carbon nano tube solution;

S2, 1 part of KH-550 is measured according to the volume ratio and dissolved in 10 parts of ethanol, 3 parts of distilled water is slowly added under the stirring condition, the pH value is regulated to be 4, the mixed solution is stood for 3 hours, and the silane coupling agent solution is obtained after the silane coupling agent is fully hydrolyzed;

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

And S4, baking the reaction mixture, cooling to room temperature, and then carrying out 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 for 5 hours at the temperature of 0 ℃, filtering, washing and drying after the reaction is finished to obtain the polyaniline-coated carbon nano tube, wherein the mass ratio of the carbon nano tube modified by the silane coupling agent to the aniline is 1:6, and the mass ratio of aniline to ammonium persulfate=1:0.05.

S6, adding polyaniline-coated carbon nanotubes into an aqueous solution containing 1wt.% of sodium dodecyl benzene sulfonate, wherein the mass ratio is 1:400, performing ultrasonic treatment to obtain a carbon nanotube suspension, slowly adding silicon dioxide powder into the carbon nanotube suspension, uniformly stirring, heating to 90 ℃ and continuously stirring for 3 hours to obtain a semi-finished product of the composite material, and the mass ratio of the silicon dioxide to the polyaniline-coated carbon nanotubes is 8:1.

And S7, drying the semi-finished product of the composite material in air, heating to 500+/-100 ℃ in a tube furnace at a temperature rising rate of 5+/-1 ℃ per minute for 120-160 min, cooling, screening and washing to obtain a finished product of the SiO ₂ -CNTs composite material, namely the antistatic agent.

Preparing an oil agent:

The formula is that the smoothing agent comprises 50 parts of laurinol oleate, 50 parts of emulsifier cardanol polyoxyethylene ether, 5 parts of antistatic agent and 1 part of stabilizer, namely polyether silicone oil of allyl acid.

S21, weighing raw materials according to a preset formula, putting a smoothing agent and an emulsifying agent into a stirring tank, and uniformly stirring at room temperature with a stirring speed of 900r/min;

s24, regulating the pH value of the semi-finished oil product to be 6 and the viscosity to be 110 mPa.s, filtering and filling the semi-finished oil product into a storage container to obtain the finished oil product.

And (3) oiling:

The high viscosity solution of ultra high molecular weight polyethylene may be obtained by mixing UHMWPE powder with white oil in a heated stirred vessel, heating to 130 ℃ to fully dissolve it to form a high viscosity solution, the ultra high molecular weight polyethylene content being 15wt.%.

S32, extruding the high-viscosity solution through a spinning nozzle, wherein the spinning aperture is 1mm, the length-diameter ratio is 6, and the ultra-high molecular weight polyethylene fiber is obtained after forming filaments and the spinning temperature is 250 ℃;

S33, immediately feeding the fiber into an extension machine for thermal extension after primary cooling, wherein the extension temperature is set at 120 ℃, and the extension proportion is 5 times of the original length;

And S34, oiling the extended fiber by coating equipment at the oiling speed of 20m/min, cooling, drying, and winding on a winding drum to obtain a fiber finished product.

Example 2

Preparation of antistatic agent:

s1, weighing or measuring 1 part of carbon nano tube and 120 parts of ethanol according to the weight components, adding the carbon nano tube into the ethanol, and performing ultrasonic dispersion to obtain a carbon nano tube solution;

S2, 1 part of KH-560 is measured according to the volume ratio and dissolved in 11 parts of ethanol, 3.5 parts of distilled water is slowly added under the stirring condition, the pH value is regulated to be 4.5, the mixed solution is kept stand for 2.5 hours, and the silane coupling agent is fully hydrolyzed to obtain a silane coupling agent solution;

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

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 for 4 hours at the temperature of 0 ℃, filtering, washing and drying after the reaction is finished to obtain the polyaniline-coated carbon nano tube, wherein the mass ratio of the carbon nano tube modified by the silane coupling agent to the aniline is 1:10, and the mass ratio of the aniline to the ammonium persulfate=1:0.1.

S6, adding polyaniline-coated carbon nanotubes into a sodium dodecyl benzene sulfonate aqueous solution containing 1.1wt.% of sodium dodecyl benzene sulfonate, wherein the mass ratio is 1:500, performing ultrasonic treatment to obtain a carbon nanotube suspension, slowly adding silicon dioxide powder into the carbon nanotube suspension, uniformly stirring, heating to 85 ℃ and continuously stirring for 3.5 hours to obtain a semi-finished product of the composite material, and the mass ratio of the silicon dioxide to the polyaniline-coated carbon nanotubes is 13:1.

Preparing an oil agent:

the pre-set formula comprises, by mass, 70 parts of a smoothing agent isooctyl oleate, 53 parts of an emulsifier polyglycerol fatty acid ester, 6 parts of an antistatic agent and 1.5 parts of a stabilizer Tween 80.

The preparation method and the oiling method of the oiling agent are the same as those of the example 1.

Example 3

Preparation of antistatic agent:

s1, weighing or measuring 1 part of carbon nano tube and 110 parts of ethanol according to the weight components, adding the carbon nano tube into the ethanol, and performing ultrasonic dispersion to obtain a carbon nano tube solution;

S2, 1 part of KH-550 is measured according to the volume ratio and dissolved in 12 parts of ethanol, 3 parts of distilled water is slowly added under the stirring condition, the pH value is regulated to be 5, the mixed solution is stood for 4 hours, and the silane coupling agent solution is obtained after the silane coupling agent is fully hydrolyzed;

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

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 for 4.5 hours at the temperature of 0 ℃, filtering, washing and drying after the reaction is finished to obtain the polyaniline-coated carbon nano tube, wherein the mass ratio of the carbon nano tube modified by the silane coupling agent to the aniline is 1:8, and the aniline is ammonium persulfate=1:0.07.

S6, adding polyaniline-coated carbon nanotubes into a sodium dodecyl benzene sulfonate aqueous solution containing 1.2wt.% of sodium dodecyl benzene sulfonate, wherein the mass ratio is 1:480, performing ultrasonic treatment to obtain a carbon nanotube suspension, slowly adding silicon dioxide powder into the carbon nanotube suspension, uniformly stirring, heating to 95 ℃ and continuously stirring for 3 hours to obtain a semi-finished product of the composite material, and the mass ratio of the silicon dioxide to the polyaniline-coated carbon nanotubes is 10:1.

Preparing an oil agent:

the pre-set formula comprises 65 parts by weight of isooctyl stearate serving as a smoothing agent, 60 parts by weight of castor oil polyoxyethylene ether serving as an emulsifying agent, 8 parts by weight of antistatic agent and 1.8 parts by weight of polyether modified silicone oil serving as a stabilizing agent.

Example 4

Preparation of antistatic agent:

s1, weighing or measuring 1 part of carbon nano tube and 105 parts of ethanol according to the weight components, adding the carbon nano tube into the ethanol, and performing ultrasonic dispersion to obtain a carbon nano tube solution;

S2, 1 part of KH-560 is measured according to the volume ratio and dissolved in 10 parts of ethanol, 3.5 parts of distilled water is slowly added under the stirring condition, the pH value is regulated to be 4.5, the mixed solution is stood for 3 hours, and the silane coupling agent is fully hydrolyzed to obtain a silane coupling agent solution;

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

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 for 6 hours at the temperature of 0 ℃, filtering, washing and drying after the reaction is finished to obtain the polyaniline-coated carbon nano tube, wherein the mass ratio of the carbon nano tube modified by the silane coupling agent to the aniline is 1:7, and the mass ratio of aniline to ammonium persulfate=1:0.09.

S6, adding polyaniline-coated carbon nanotubes into an aqueous solution containing 1wt.% of sodium dodecyl benzene sulfonate, wherein the mass ratio is 1:430, performing ultrasonic treatment to obtain a carbon nanotube suspension, slowly adding silicon dioxide powder into the carbon nanotube suspension, uniformly stirring, heating to 80 ℃ and continuously stirring for 3.5 hours to obtain a semi-finished product of the composite material, and the mass ratio of the silicon dioxide to the polyaniline-coated carbon nanotubes is 15:1.

Preparing an oil agent:

The formula is that according to the weight portion, the smoothing agent glycerol trioleate is 55 portions, the emulsifier cardanol polyoxyethylene ether is 23 portions+polyglycerol fatty acid ester is 34 portions, the antistatic agent is 4 portions, and the stabilizer is 2 portions.

Comparative example 1

Compared with example 4, the carbon nanotubes were not modified with a silane coupling agent (no steps S2, S3), and the rest of the process conditions and operations were the same.

Comparative example 2

Compared with example 4, polyethylene glycol is adopted to replace polyaniline to coat the carbon nano tube, and the rest process conditions and operation are the same.

Comparative example 3

Compared with example 4, the process of loading the carbon nanotubes with silicon dioxide (without step S6) was omitted, and the other process conditions and operations were the same.

And (3) performance detection:

the breaking strength and initial modulus of the ultra-high molecular weight polyethylene fiber are tested by referring to the GB/T19975-2005 high strength fiber filament tensile property test method. The static voltage is measured by a Kernel SK-H static measuring instrument. And (3) high temperature resistance test, namely putting the fiber into a 200 ℃ oven for 72 hours, taking out, and testing the breaking strength of the fiber. The test results are shown in Table 1.

TABLE 1 list of ultra high molecular weight polyethylene fiber properties

As can be seen from the above table, comparative example 1 resulted in aggregation and accumulation of carbon nanotubes, a decrease in antistatic property, an increase in electrostatic pressure, and a decrease in initial modulus and breaking strength due to lack of reinforcement of carbon nanotubes, since the carbon nanotubes were not modified with the silane coupling agent.

In comparative example 2, the polyaniline is replaced by polyethylene glycol, so that the synergistic conductive effect of the polyaniline and the carbon nanotubes cannot be exerted, the antistatic performance is reduced, and the electrostatic pressure is increased.

In comparative example 3, silica is omitted as a carrier, and polyaniline-coated carbon nanotubes are directly added into an oiling agent, so that the thermal stability of fibers is reduced due to the lack of silica, and the breaking strength is obviously reduced after high-temperature treatment. Meanwhile, the dispersion uniformity of the carbon nano tube is reduced, the carbon nano tube is easy to settle and aggregate in the oiling agent, and the fiber breaking strength is reduced.

In conclusion, the ultra-high molecular weight polyethylene fiber treated by the oiling agent (containing the electrostatic agent provided by the invention) has the electrostatic voltage less than or equal to 0.041kV, the initial modulus more than or equal to 1900cN/dtex, the initial breaking strength more than or equal to 40.0cN/dtex and smaller breaking strength drop under the high-temperature condition, and the fiber is taken out after being put into a 200 ℃ oven for 72 hours, and the breaking strength drop is less than or equal to 9.2 percent.

The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. The preparation method of the antistatic agent is characterized by comprising the steps of firstly modifying a carbon nano tube by using a silane coupling agent, then coating the modified carbon nano tube by using polyaniline, and finally loading the polyaniline-coated modified carbon nano tube on a silicon dioxide carrier to obtain a SiO ₂ -CNTs composite material finished product, namely the antistatic agent.

2. The preparation method according to claim 1, characterized by comprising the following steps:

3. 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.

4. The preparation method of claim 2, 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.

5. The preparation method according to claim 2, 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.

6. The preparation method of the catalyst according to claim 2, 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.

7. The preparation method of the polyaniline-coated carbon nanotube composite material according to claim 2, 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.

8. The method according to claim 2, wherein the heat treatment in step S7 is specifically performed by drying the semi-finished composite material in air, and then heating to 500±100 ℃ in a tube furnace at a temperature rising rate of 5±1 ℃ per minute for 120 to 160 minutes.

9. An antistatic agent, characterized in that it is produced by the production method according to any one of claims 1 to 8.

10. An oil for ultra-high molecular weight polyethylene fibers, characterized in that the oil comprises the antistatic agent according to claim 9.