Anti-static polyester staple fiber and preparation method thereof

Abstract

According to the anti-static polyester staple fiber and the preparation method thereof provided by the invention, acrylate soft monomers, acrylate hard monomers, a cross-linking agent and a functional monomer react to polymerize on the surface of the polyester staple fiber to obtain a polyacrylate protective film, hydrophilic groups and quaternary ammonium cation conductive groups are introduced, and the polyacrylate protective film is endowed with conductive performance; the anti-static performance of the polyester staple fiber is improved. Meanwhile, modified conductive particles with core-shell structures are introduced, and PNIPAM shell layers have temperature responsiveness, so that the anti-static performance, the mechanical performance and the temperature resistance of the polyester staple fibers can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyester fibers, and particularly relates to a method for preparing antistatic polyester staple fibers. Background Art

[0002] Polyester (polyethylene terephthalate, PET) fibers are widely used in the fields of textiles, medicine, electronics, and military industry due to their excellent mechanical properties, chemical resistance, and low cost. However, the high insulation and hydrophobicity of polyester fibers make them prone to accumulating static electricity due to friction, resulting in problems such as dust adsorption, electric shock risk, and damage to electronic devices. Generally, the methods for improving antistatic performance mainly include blending modification, surface treatment, and structural design. Structural design refers to optimizing the charge dissipation path through profiled cross-sections or composite spinning. For example, CN117845368A provides an antistatic skin-core composite nylon fiber with a skin-core structure. The core material nylon 6 chips and the skin material carbon black conductive masterbatch are respectively dried and then melt-compressed to obtain melt A and melt B. Melt A is used as the core layer, and melt B is used as the skin layer. After mixing, they are subjected to composite spinning and then ejected to obtain a melt with a skin-core structure. After side blowing cooling, bundling and oiling, secondary cooling in the channel, stretching and setting, and finally winding, an antistatic composite fiber with a skin-core structure is obtained, and its surface resistance value can reach 104Ω, but its spinnability and processing performance are poor. Blending modification is achieved by melt-blending and spinning PET with conductive materials or hydrophilic materials to endow the fibers with durable antistatic performance. For example, CN102851783A uses the conductive polymer polypyrrole as an antistatic agent. The antistatic agent and the carrier resin are blended and melt-extruded to form pellets. After blending the antistatic masterbatch and polyester fiber chips, antistatic polyester fibers are formed through spinning, winding, and stretching. However, its dispersibility is poor, and the antistatic effect is not good. Surface treatment is to construct a conductive layer and / or a hydrophilic layer on the fiber surface through coating or chemical modification. For example, CN101845753A immerses polyester fabrics in a dispersion solution of conductive polymer particles for wet impregnation treatment, followed by reduction cleaning, rinsing, and drying and setting to obtain antistatic fabrics with a conductive layer on the surface. However, the surface coating conductive layer is prone to peeling off, and the durability is poor. Summary of the Invention

[0003] In order to overcome the problems existing in the prior art, the object of the present invention is to provide an antistatic polyester staple fiber. Through the reaction of acrylate soft monomers, acrylate hard monomers, crosslinking agents, and functional monomers, a polyacrylate protective film is polymerized on the surface of the polyester staple fiber, introducing hydrophilic groups and quaternary ammonium cation conductive groups to endow the polyacrylate protective film with conductive properties and improve the antistatic performance of the polyester staple fiber. At the same time, modified conductive particles with a core-shell structure are introduced, and their PNIPAM shell layer has temperature responsiveness, which can improve the antistatic performance, mechanical properties, and temperature resistance durability of the polyester staple fiber.

[0004] The object of the present invention is achieved by the following technical solutions: An antistatic polyester staple fiber, and its preparation method comprises the following steps: (1) Surface treatment of polyester staple fiber: Immerse the polyester staple fiber in an alkali treatment solution, react at 45 - 80 °C for 15 - 25 min to obtain the surface-treated polyester staple fiber; the alkali treatment solution is prepared by dissolving ethylenediamine and sodium hydroxide in deionized water, the mass concentration of ethylenediamine is 1 - 3%, and the mass concentration of sodium hydroxide is 25 - 30%; (2) Preparation of antistatic finishing agent: Using isooctyl acrylate 10 - 20%, butyl acrylate 10 - 20%, methyl methacrylate 5 - 12%, styrene 5 - 12%, acrylamide 0.2 - 1%, acryloyloxyethyl trimethyl ammonium chloride 0.5 - 4%, acryloyloxyethyl dimethyl benzyl ammonium chloride 0.5 - 4%, N,N'-methylenebisacrylamide 0.5 - 2%, diacetone acrylamide 0.5 - 3%, modified conductive particles 0.5 - 2%, emulsifier 0.2 - 0.8%, oxidant 0.01 - 0.05% and the balance of deionized water as raw materials, mix and stir for 10 - 25 min to obtain an antistatic finishing agent solution; (3) Impregnation reaction: Place the surface-roughened polyester staple fiber obtained in step (1) into the antistatic finishing agent solution obtained in step (2) according to a volume ratio of 1:25 - 1:60, stir, heat up, add 0.01 - 0.05% of a reducing agent dropwise at 25 - 40 °C, react for 15 - 40 min, cool down, filter, wash, and dry to obtain the antistatic polyester staple fiber.

[0005] Preferably, the modified conductive particles are conductive particles with a core-shell structure, the core layer is conductive particles with amino active groups on the surface, and the shell layer is PNIPAM with a temperature-responsive function.

[0006] Preferably, the conductive particles with amino active groups on the surface are conductive particles modified with an amino silane coupling agent, and the conductive particles are one or more of carbon nanotubes, montmorillonite, graphene, carbon black, metal particles, and metal oxide particles.

[0007] Preferably, the preparation method of the modified conductive particles comprises the following steps: Step A, Disperse the amino silane coupling agent and the conductive particles in water, stir to form a suspension, continue to stir and heat up to 25 - 55 °C, react for 0.5 - 1 h, filter, wash, and dry to obtain the conductive particles with amino active groups on the surface.

[0008] Step B, Mix N-isopropylacrylamide, N,N'-methylenebisacrylamide, emulsifier, and deionized water in sequence, stir until evenly dispersed to prepare a pre-emulsion.

[0009] Step C: Mix 1 / 3 of the pre-emulsion with the conductive particles having amino active groups on the surface obtained in Step A, and ultrasonicate for 10 - 30 min to obtain a seed pre-emulsion.

[0010] Step D: Add the seed pre-emulsion, emulsifier, initiator, and deionized water obtained in Step C into a reactor, start stirring, heat up to 25 - 65 °C, and react for 15 - 45 min to obtain a seed emulsion.

[0011] Step E: Then, add the remaining pre-emulsion dropwise into the reactor, finish dropping within 1 - 3 h, supplement the redox initiator, continue to keep warm for 0.5 - 2 h, cool down, and discharge to obtain modified conductive particles with a core-shell structure.

[0012] Preferably, the surface treatment of the polyester staple fibers in step (1) includes: cleaning the polyester staple fibers with acetone, ethanol, and water respectively, drying, and then immersing the polyester staple fibers in an alkali treatment solution at a volume ratio of 1:25 - 1:60, reacting at 45 - 80 °C for 15 - 25 min, washing with water, and drying to obtain surface-treated polyester staple fibers.

[0013] Preferably, the emulsifier includes one or more of cetyltrimethylammonium bromide, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, polyvinyl alcohol, Tween, and Span.

[0014] Preferably, the reducing agent is one or more of APS, KPS, BPO, AIBN, AIVN, ferrous sulfite, sodium bisulfite, hydrogen peroxide, and vitamin C.

[0015] A preparation method of antistatic polyester staple fibers specifically includes the following steps: (1) Surface treatment of polyester staple fibers: Clean the polyester staple fibers with acetone, ethanol, and water respectively, dry, and then immerse the polyester staple fibers in an alkali treatment solution at a volume ratio of 1:25 - 1:60, react at 45 - 80 °C for 15 - 25 min, wash with water, and dry to obtain surface-treated polyester staple fibers; the alkali treatment solution is prepared by dissolving ethylenediamine and sodium hydroxide in deionized water, the mass concentration of ethylenediamine is 1 - 3%, and the mass concentration of sodium hydroxide is 25 - 30%; (2) Preparation of antistatic finishing agent: Using isooctyl acrylate 10-20%, butyl acrylate 10-20%, methyl methacrylate 5-12%, styrene 5-12%, acrylamide 0.2-1%, acryloyloxyethyl trimethyl ammonium chloride 0.5-4%, acryloyloxyethyl dimethyl benzyl ammonium chloride 0.5-4%, N,N'-methylenebisacrylamide 0.5-2%, diacetone acrylamide 0.5-3%, modified conductive particles 0.5-2%, emulsifier 0.2-0.8%, oxidant 0.01-0.05% and deionized water as the balance of raw materials, mixing and stirring for 10-25 min to obtain an antistatic finishing agent solution.

[0016] (3) Impregnation reaction: Place the surface-roughened polyester staple fibers obtained in step (1) into the antistatic finishing agent solution obtained in step (2) according to a volume ratio of 1:25-1:60, stir, heat up, add 0.01-0.05% of reducing agent dropwise at 25-40 °C, react for 15-60 min, cool down, filter, wash, and dry to obtain antistatic polyester staple fibers.

[0017] The beneficial effects of the present invention are as follows: 1. The antistatic finishing agent of the present invention polymerizes a polyacrylate protective film on the surface of polyester staple fibers through the reaction of acrylate soft monomers, acrylate hard monomers, crosslinking agents, and functional monomers. On the one hand, the ester groups are similar to the ester structure of polyester fibers, which can improve the binding force between the polyacrylate protective film and polyester staple fibers. On the other hand, the cationic monomers acryloyloxyethyl trimethyl ammonium chloride and acryloyloxyethyl dimethyl benzyl ammonium chloride have quaternary ammonium cation conductive groups, which can endow the polyacrylate protective film with conductive properties. In addition, the hydrophilicity of the monomers can make the polyacrylate protective film hydrophilic, thereby improving the antistatic performance of polyester staple fibers.

[0018] 2. The modified conductive particles of the present invention have a core-shell structure, and its PNIPAM shell layer has temperature responsiveness, which can shrink above its LCST temperature, release conductive particles with surface amino groups, and improve the conductive properties of the polyacrylate protective film. At the same time, the modified conductive particles can improve the mechanical properties of the polyacrylate protective film. Thus, the antistatic performance, mechanical properties, and temperature resistance durability of polyester staple fibers are improved.

[0019] 3. The polyacrylate protective film of the present invention introduces diacetone acrylamide. The ketone group of diacetone acrylamide can react with the amino group on the surface of the modified conductive particles to form a reversible imine bond through a Schiff base reaction, enabling the polyacrylate protective film layer to have a self-healing function. When scratches or damages occur on the polyacrylate protective film, self-healing can be achieved through the Schiff base reaction, improving the antistatic performance, scratch resistance, and temperature resistance durability of polyester staple fibers. Detailed Embodiments

[0020] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] The present invention will be further explained below in conjunction with specific embodiments.

[0022] Preparation Example 1 Modified conductive particles, the preparation method includes the following steps: Step A, carbon nanotubes and amino silane coupling agent KH550 are dispersed in water according to a mass ratio of 1:20, stirred to form a suspension, and continuously stirred and heated to 35 °C, reacted for 1 h, filtered, washed, and dried to obtain KH550-modified carbon nanotubes.

[0023] Step B, 40 parts by weight of N-isopropylacrylamide, 5 parts by weight of N,N'-methylenebisacrylamide, 0.5 part by weight of emulsifier sodium dodecylbenzenesulfonate, and 120 parts by weight of deionized water are successively mixed and stirred until evenly dispersed to prepare a pre-emulsion.

[0024] Step C, 1 / 3 of the pre-emulsion and 6 parts by weight of KH550-modified carbon nanotubes are mixed and ultrasonicated for 10 - 30 min to obtain a seed pre-emulsion.

[0025] Step D, add the seed pre-emulsion obtained in Step C, 0.3 part by weight of emulsifier sodium dodecylbenzenesulfonate, 0.2 part by weight of initiator ammonium persulfate, and 50 parts by weight of deionized water to the reactor, start stirring, heat up to 45 °C, and react for 25 min to obtain a seed emulsion; Step E, then, the remaining pre-emulsion obtained in Step B is added dropwise to the reactor, and the addition is completed within 3 h. Add redox initiator H2O2 / sodium bisulfite, continue to keep warm for 2 h, cool down, and discharge to obtain modified conductive particles with a core-shell structure.

[0026] Preparation Example 2 Modified conductive particles are prepared according to the method of Preparation Example 1, and the only difference is that the amino silane coupling agent KH550 is replaced by titanate coupling agent CT-928.

[0027] Example 1 An antistatic polyester staple fiber, its preparation method includes the following steps: (2)Surface treatment of polyester staple fiber: Clean the polyester staple fiber with acetone, ethanol, and water respectively, dry it, and then immerse the polyester staple fiber in the alkali treatment solution at a volume ratio of 1:45, react at 45 °C for 20 min, wash with water, and dry to obtain the surface-treated polyester staple fiber; the alkali treatment solution is prepared by dissolving ethylenediamine and sodium hydroxide in deionized water, wherein the mass concentration of ethylenediamine is 3%, and the mass concentration of sodium hydroxide is 28%. (2)Preparation of antistatic finishing agent: Weigh the materials by weight. Using isooctyl acrylate 18%, butyl acrylate 12%, methyl methacrylate 6%, styrene 5%, acrylamide 0.8%, acryloyloxyethyl trimethyl ammonium chloride 3%, acryloyloxyethyl dimethyl benzyl ammonium chloride 0.8%, N,N'-methylenebisacrylamide 0.5%, diacetone acrylamide 1.2%, the modified conductive particles obtained in Preparation Example 1 1.5%, emulsifier sodium dodecylbenzenesulfonate 0.6%, oxidant ammonium persulfate 0.04%, and the balance of deionized water as raw materials, mix and stir for 25 min to obtain the antistatic finishing agent solution.

[0028] (3)Impregnation reaction: Place the surface-roughened polyester staple fiber obtained in step (1) in the antistatic finishing agent solution obtained in step (2) at a volume ratio of 1:30, stir, heat up, add 0.04% of reducing agent sodium bisulfite dropwise at 30 °C, react for 40 min, cool down, filter, wash, and dry to obtain the antistatic polyester staple fiber.

[0029] Comparative Example 1 An antistatic polyester staple fiber is prepared according to the method of Example 1, and the only difference is that acryloyloxyethyl trimethyl ammonium chloride and acryloyloxyethyl dimethyl benzyl ammonium chloride are replaced by acrylamide.

[0030] Comparative Example 2 An antistatic polyester staple fiber is prepared according to the method of Example 1, and the only difference is that the modified conductive particles obtained in Preparation Example 1 are replaced by the modified conductive particles obtained in Preparation Example 2.

[0031] Comparative Example 3 An antistatic polyester staple fiber is prepared according to the method of Example 1, and the only difference is that diacetone acrylamide is replaced by N,N-methylenebisacrylamide.

[0032] Comparative Example 4 An antistatic polyester staple fiber is prepared according to the method of Example 1, and the only difference is that the modified conductive particles obtained in Preparation Example 1 are replaced by the KH550-modified carbon nanotubes obtained in step A of Preparation Example 1.

[0033] Performance test The antistatic polyester staple fibers obtained in Example 1 and Comparative Examples 1-4 were characterized for their properties.

[0034] Volume resistivity: According to the test standard GB / T 1410-2006, the antistatic polyester staple fibers were evenly spread on an insulating substrate, a voltage of 100 V was applied, and the current was measured to calculate the resistivity.

[0035] Electrostatic half-life: According to the test standard GB / T 12703.1-2021, using an electrostatic decay tester Honestest H011 equipped with a fiber fixing device, a high voltage (±5 kV) was applied to charge the fiber sample, and the time when the voltage decayed to 50% of the initial value was recorded.

[0036] Tensile strength: According to the test standard GB / T 14344-2008, using an electronic single fiber strength tester Instron 3343 equipped with a pneumatic clamping fixture, the test was carried out under the conditions of a gauge length of 10 mm and a tensile speed of 10 mm / min.

[0037] Table 1 Properties of antistatic polyester staple fibers

[0038] From the comparison of Example 1, Comparative Example 1, and Comparative Example 4, it can be seen that the antistatic polyester staple fibers prepared in Example 1 of the present invention have better effects in terms of volume resistivity, electrostatic half-life, volume resistivity after washing 500 times at 45 °C, and tensile strength. This may be because in Example 1, through the reaction of acrylate soft monomers, acrylate hard monomers, crosslinking agents, and functional monomers, a polyacrylate protective film was polymerized on the surface of the polyester staple fibers. On the one hand, the cationic monomers acryloyloxyethyltrimethylammonium chloride and acryloyloxyethyldimethylbenzylammonium chloride have quaternary ammonium cation conductive groups, which can endow the polyacrylate protective film with conductive properties; on the other hand, the polar groups of the copolymer monomers can improve the binding force between the polyacrylate protective film and the polyester staple fibers, and the hydrophilicity of the monomers can make the polyacrylate protective film hydrophilic, thereby improving the antistatic performance of the polyester staple fibers; in addition, the modified conductive particles have a core-shell structure, the core is KH550-modified carbon nanotubes, and the shell is a PNIPAM shell layer, which can simultaneously improve the hydrophilicity, conductivity, and mechanical properties of the polyacrylate protective film.

[0039] From the comparison among Example 1, Comparative Example 2 and Comparative Example 3, it can be seen that the antistatic polyester staple fibers prepared in Example 1 of the present invention have better effects in terms of volume resistivity, electrostatic half-life, volume resistivity after 500 washes at 45°C, and tensile strength. This may be because in Example 1, the polyacrylate protective film uses diacetone acrylamide as a functional monomer to introduce a ketone group, which can react with the amino group on the surface of KH550-modified carbon nanotubes to form a reversible imine bond through a Schiff base reaction, enhancing the three-dimensional network structure and network path of the polyacrylate protective film, thereby improving the electrical conductivity, mechanical properties, and scratch and abrasion resistance of the polyacrylate protective film, and improving the antistatic performance, mechanical properties, and water wash resistance of the polyester staple fibers.

[0040] From the comparison between Example 1 and Comparative Example 4, it can be seen that the antistatic polyester staple fibers prepared in Example 1 of the present invention have better effects in terms of electrostatic half-life, volume resistivity after 500 washes at 45°C, and tensile strength. This may be because in Example 1, on the one hand, the modified conductive particles have a core-shell structure, which can improve the mechanical properties of the polyacrylate protective film; on the other hand, the PNIPAM shell layer of the modified conductive particles has a temperature responsiveness and can shrink above its LCST, releasing the conductive particles KH550-modified carbon nanotubes. The amino group on the surface of the KH550-modified carbon nanotubes reacts with the ketone group of the comonomer diacetone acrylamide of the polyacrylate through a Schiff base reaction to form a reversible imine bond, enhancing the three-dimensional network structure and network path of the polyacrylate protective film, thereby improving the electrical conductivity, mechanical properties, high-temperature resistance, and scratch and abrasion resistance of the polyacrylate protective film, and improving the antistatic performance, mechanical properties, temperature resistance durability, and water wash resistance of the polyester staple fibers.

[0041] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for preparing antistatic polyester staple fibers, characterized in that, It includes the following steps: (1) Surface treatment of polyester staple fiber: Immerse the polyester staple fiber in an alkali treatment solution and react at 45 - 80 °C for 15 - 25 min to obtain surface-treated polyester staple fiber; the alkali treatment solution is prepared by dissolving ethylenediamine and sodium hydroxide in deionized water, the mass concentration of ethylenediamine is 1 - 3%, and the mass concentration of sodium hydroxide is 25 - 30%; (2) Preparation of antistatic finishing agent: Using isooctyl acrylate 10 - 20%, butyl acrylate 10 - 20%, methyl methacrylate 5 - 12%, styrene 5 - 12%, acrylamide 0.2 - 1%, acryloyloxyethyl trimethyl ammonium chloride 0.5 - 4%, acryloyloxyethyl dimethyl benzyl ammonium chloride 0.5 - 4%, N,N'-methylenebisacrylamide 0.5 - 2%, diacetone acrylamide 0.5 - 3%, modified conductive particles 0.5 - 2%, emulsifier 0.2 - 0.8%, oxidant 0.01 - 0.05% and the balance of deionized water as raw materials, mix and stir to obtain an antistatic finishing agent solution; (3) Impregnation reaction: Place the surface-roughened polyester staple fiber obtained in step (1) in the antistatic finishing agent solution obtained in step (2) according to a volume ratio of 1:25 - 1:60, stir, heat up, add 0.01 - 0.05% of reducing agent dropwise at 25 - 40 °C, and react for 15 - 40 min to obtain antistatic polyester staple fiber.

2. The antistatic polyester staple fiber according to claim 1, wherein The modified conductive particles have a core-shell structure, the core layer is a conductive particle with an amino active group on the surface, and the shell layer is PNIPAM.

3. The antistatic polyester staple fiber according to claim 2, wherein, The conductive particle with an amino active group on the surface is a conductive particle modified by an amino silane coupling agent.

4. The antistatic polyester staple fiber according to claim 2, wherein The conductive particle is one or more of carbon nanotubes, montmorillonite, graphene, carbon black, metal particles, and metal oxide particles.

5. The antistatic polyester staple fiber according to any one of claims 1-4, characterized in that, The preparation method of the modified conductive particles includes the following steps: Step A, Disperse the amino silane coupling agent and the conductive particle in water, stir to form a suspension, continue to stir and heat up to 25 - 55 °C, react for 0.5 - 1 h, filter, wash, and dry to obtain a conductive particle with an amino active group on the surface; Step B, Mix N-isopropylacrylamide, N,N'-methylenebisacrylamide, emulsifier, and deionized water in sequence, and stir until evenly dispersed to make a pre-emulsion; Step C, Mix 1 / 3 of the pre-emulsion and the conductive particle with an amino active group on the surface obtained in step A, and ultrasonicate for 10 - 30 min to obtain a seed pre-emulsion; Step D, Add the seed pre-emulsion, emulsifier, initiator, and deionized water obtained in step C to a reactor, start stirring, heat up to 25 - 65 °C, and react for 15 - 45 min to obtain a seed emulsion; Step E, Then, dropwise add the remaining pre-emulsion to the reactor, finish dropping within 1 - 3 h, add redox initiator, continue to keep warm for 0.5 - 2 h, cool down, and discharge to obtain modified conductive particles with a core-shell structure.

6. The antistatic polyester staple fiber according to claim 1, wherein The reducing agent is one or more of APS, KPS, BPO, AIBN, AIVN, ferrous sulfite, sodium bisulfite, hydrogen peroxide, and vitamin C.

7. The antistatic polyester staple fiber according to claim 1, characterized in that, The emulsifier includes one or more of cetyltrimethylammonium bromide, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, polyvinyl alcohol, Tween, and Span.

8. An antistatic polyester staple fiber, characterized in that, The antistatic polyester staple fiber is prepared by the preparation method according to any one of claims 1-7.

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