Polyamide 6 High Conductivity Fabric for Textile-Based Electronics and Its Preparation Method

Abstract

This invention discloses a polyamide 6 highly conductive fabric for textile-based electronic products and its preparation method, comprising the following steps: (1) mixing a certain amount of precursor with a complexing agent to obtain a mixture; (2) adding a certain amount of solvent to the mixture to obtain an ink mixture; (3) filtering to obtain conductive ink, and storing it in the dark; (4) preparing a modifier; (5) using a rolling mill to uniformly roll the modifier onto the polyamide 6 fabric; (6) drying, sealing and storing to obtain a modified polyamide 6 fabric; (7) uniformly brushing conductive ink onto the surface of the modified polyamide 6 fabric 2-4 times; (8) vacuum sintering treatment. This invention eliminates the reducing agent and other additives in the ink, avoiding the influence of many chemicals in the ink on the conductivity of the nano-silver layer. At the same time, by modifying the surface of the polyamide 6 fiber, the spreading and penetration of the ink on the fiber surface is controlled, thus realizing the preparation of a highly conductive silver layer.

Description

Technical Field

[0001] This invention belongs to the field of smart textile technology, and particularly relates to a polyamide 6 high conductivity fabric for textile-based electronic products and its preparation method. Background Technology

[0002] In recent years, with the rapid development of intelligent technologies, sensors have received increasing attention. Compared to traditional fixed sensing devices, textile-based flexible sensors combine sensing capabilities with the advantages of fabrics, converting human vital signs and movement intensity into electrical signals to transmit physiological information. By conforming closely to the human body, they also enable large-area sensing. These sensors can be widely used in motion monitoring, security monitoring, human-computer interaction, and healthcare. Consequently, the demand for high-performance textile-based electronic products is constantly increasing.

[0003] Currently, conductive fabrics, as a fundamental material in textile-based electronic products, determine the performance of these flexible electronic products based on their conductivity. Existing technologies mostly rely on adjusting the conductive ink formulation to improve the conductivity of conductive fabrics. By adjusting the types and amounts of each component, conductive fabrics can be prepared under milder conditions. Examples include the following patented technologies:

[0004] CN112694790A discloses a silver-based particle-free conductive ink, comprising the following components in parts by weight: 40-50 parts silver powder particles; 10-15 parts carbon nanotubes; 20-40 parts polyurethane fibers; 30-35 parts thermoplastic curing agent; and 6-10 parts additives. Silver powder particles and carbon nanotubes are the main conductive phases, wherein the silver powder particles are dendritic silver powder particles, and the carbon nanotubes can adhere to the silver powder particles. In the cured conductive ink, the dendritic silver powder particles interweave with each other, and the attached carbon nanotubes increase the contact area between particles, compensating for the shrinkage difference of the cured conductive ink, thus ensuring good conductivity even under bending and folding conditions. Furthermore, the conductive ink uses a thermoplastic curing agent supplemented with polyurethane fibers. The thermoplastic curing agent possesses both elasticity and toughness after curing, while the polyurethane fibers have good tensile strength. The combined effect of these two components gives the cured conductive ink good bending and tensile resistance.

[0005] CN106752384A discloses an elastic nanofiber conductive ink, comprising a conductive material, a matrix material, and a solvent. The matrix material is uniformly suspended in the solvent, and the conductive material is uniformly coated on the surface of the matrix material. The conductive material is one of polypyrrole, polyaniline, and polythiophene. The matrix material is nanofiber. The solvent is an organic volatile solvent. The preparation method includes: 1) mixing a thermoplastic elastomer with cellulose acetate ester uniformly, stretching it into elastic fibers using a screw extruder, and removing the cellulose acetate with acetone to obtain nanofibers; 2) adding an organic volatile solvent to the nanofibers and shearing and dispersing them to prepare a nanofiber suspension; 3) adding a conductive polymer monomer and an oxidizing dopant to the nanofiber suspension, performing an in-situ polymerization reaction to obtain a polymer solution, and washing the polymer solution to obtain the elastic nanofiber conductive ink.

[0006] While the aforementioned patented technologies have advantages, with the increase in chemical components, the amount of non-conductive substances in the ink also increases. The high thermal decomposition temperature of some chemicals makes it impossible to remove impurities during sintering, thus affecting the conductivity of the nano-silver layer. Furthermore, in the preparation of conductive fabrics, most ink formulations contain strong reducing agents, which makes silver in the ink easily precipitate, resulting in silver waste after filtration.

[0007] Furthermore, there is currently limited research on preparing nano-silver layers by printing particle-free nano-silver conductive ink onto the surface of polyamide 6 fibers. Therefore, simplifying the ink formulation, eliminating reducing agents and other additives in the ink, and avoiding the influence of various chemicals in the ink on the conductivity of the nano-silver layer; simultaneously, controlling the spreading and penetration of the ink on the fiber surface to achieve the preparation of a highly conductive silver layer; and simplifying the preparation process to effectively improve the utilization rate of chemicals while avoiding environmental pollution have become pressing challenges for technicians in the field of smart textiles. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the technical problem to be solved by this invention is to provide a polyamide 6 high-conductivity fabric for textile-based electronic products and its preparation method, which effectively solves the interference of the complex composition of conductive ink and the capillary phenomenon of the fabric itself on the highly conductive nano-silver layer, improves conductivity, and reduces resistivity.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing polyamide 6 highly conductive fabric for textile-based electronic products, characterized by comprising the following steps:

[0010] I. Preparation of conductive ink:

[0011] (1) Take a certain amount of precursor and complexing agent and mix them. The molar ratio of precursor to complexing agent is 2:1-1:2. After mixing, stir to obtain a mixture. Cool to room temperature and set aside.

[0012] (2) Add a certain amount of solvent to the mixture and stir thoroughly to dissolve it, thus obtaining the ink mixture;

[0013] (3) Filter the ink mixture obtained in step (2) to obtain conductive ink, and store it in the dark and cold.

[0014] II. Polyamide 6 fabric modification:

[0015] (4) Prepare a reducing agent aqueous solution with a mass fraction of 9%-21%, stir to dissolve, and then add a polymer solution with a mass fraction of 6%-14% to prepare a modifier;

[0016] (5) Use a rolling mill to evenly roll the modifier onto the polyamide 6 fabric, two dips and two grapples to four dips and four grapples, pressure 2-3 kg, speed 2-5 r / min;

[0017] (6) After impregnation, dry at 50-70℃ and seal for storage to obtain modified polyamide 6 fabric;

[0018] III. Preparation of a conductive silver layer:

[0019] (7) Using screen printing, evenly brush conductive ink 2-4 times onto the surface of the modified polyamide 6 fabric to make the conductive ink evenly deposited on the fiber surface of the modified polyamide 6 fabric.

[0020] (8) The modified polyamide 6 fabric after coating is subjected to vacuum sintering to obtain a polyamide 6 high conductivity fabric with a uniformly covered conductive silver layer.

[0021] In the above-mentioned method for preparing polyamide 6 high-conductivity fabric for textile-based electronic products, in step (1), the molar ratio of the precursor to the complexing agent is 1:1.2.

[0022] In the above-mentioned method for preparing polyamide 6 high-conductivity fabric for textile-based electronic products, in step (1), the precursor is any one of silver acetate, silver carbonate, silver citrate, and silver oxalate, and the complexing agent is any one of isopropanolamine, ammonia, diethanolamine, and triethanolamine.

[0023] In the above-mentioned method for preparing polyamide 6 high-conductivity fabric for textile-based electronic products, in step (2), the solvent is ethanol, and the mass percentage of the solvent in the ink mixture is 33.3%.

[0024] In the above-mentioned method for preparing polyamide 6 high-conductivity fabric for textile-based electronic products, in step (4), the reducing agent is any one of ascorbic acid, glucose, glutaraldehyde, and ethylene glycol, and the polymer is any one of hydroxypropyl methylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone, and polyvinyl alcohol.

[0025] In the above-mentioned method for preparing polyamide 6 high-conductivity fabric for textile-based electronic products, in step (4), the mass fraction of the reducing agent aqueous solution is 15% and the mass fraction of the polymer solution is 10%.

[0026] In the above-mentioned method for preparing polyamide 6 high-conductivity fabric for textile-based electronic products, in step (5), the padding is controlled as three dips and three slits, the pressure is 2.5 kg, and the rotation speed is 3 r / min.

[0027] In the above-mentioned method for preparing polyamide 6 high-conductivity fabric for textile-based electronic products, in step (8), the vacuum sintering temperature is 90℃~180℃ and the sintering time is 30min.

[0028] A polyamide 6 highly conductive fabric for textile-based electronic products is prepared by any of the above methods.

[0029] The aforementioned polyamide 6 highly conductive fabric for textile-based electronic products has a conductive silver layer covering its surface with a thickness of 8.7 × 10⁻⁶. -6 -4.3×10 -5 rice.

[0030] The advantages of this invention regarding the polyamide 6 high-conductivity fabric for textile-based electronic products and its preparation method are as follows: First, during the sintering process, ethanol evaporates rapidly, and the silver amine complex reacts quickly with the AA coated on the surface of the polyamide 6 fiber, reducing silver amine ions to elemental silver. Due to the strong reactivity of the hydroxyl groups on the AA, they readily form hydrogen bonds with oxygen on the HPMC molecular chain. Therefore, the AA is adsorbed onto the HPMC molecular chain, simultaneously masking low-surface-energy groups near the hydrogen bonds, allowing the ink to spread smoothly. Within the spreading range, silver particles nucleate and continuously grow with heating time. Furthermore, sintering at 150°C for 30 minutes decomposes the silver amine complex and isopropanolamine, resulting in a large number of high-purity, tightly packed silver particles. Second, HPMC forms a continuous film between adjacent fibers and at the interlacing of warp and weft yarns, preventing ink penetration and silver loss. The prepared nano-silver layer exhibits good conductivity and low resistivity, endowing the fabric with excellent high conductivity. Moreover, the preparation method of this invention is simple, with high raw material utilization, making it suitable for industrial-scale mass production. Attached Figure Description

[0031] Figure 1 A diagram showing the intermolecular forces on the surface of AA / HPMC modified nylon fabric and the chemical reaction mechanism on the surface of AA / HPMC modified nylon ink-dropping fabric;

[0032] Figure 2This is a 1000x magnified SEM image of the surface of the modified polyamide 6 fabric fibers in Example 2.

[0033] Figure 3 This is a 5000x magnified SEM image of the conductive silver layer on the surface of the polyamide 6 highly conductive fabric prepared in Example 2.

[0034] Figure 4 XPS energy spectrum of Ag3d on the surface of the polyamide 6 highly conductive fabric prepared in Example 2;

[0035] Figure 5 The XRD diffraction pattern of Ag on the surface of the polyamide 6 highly conductive fabric prepared in Example 2 is shown below.

[0036] Figure 6 The images show SEM images of the original fabric and the fabric samples after sintering with printing ink of the polyamide 6 fabric modified by mixing 15% AA with different mass fractions of HPMC in Examples 4-8.

[0037] Figure 7 The graph shows the surface resistivity curves of the polyamide 6 fabric printing ink modified by mixing 15% AA with different mass fractions of HPMC in Examples 4-8 after sintering. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] In this invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish an order. The term "multiple" means "two or more".

[0040] A method for preparing a polyamide 6 highly conductive fabric for textile-based electronic products includes the following steps:

[0041] I. Preparation of conductive ink:

[0042] (1) Take a certain amount of precursor and complexing agent and mix them. The molar ratio of precursor to complexing agent is 2:1-1:2. After mixing, stir to obtain a mixture. Cool to room temperature and set aside.

[0043] (2) Add a certain amount of solvent to the mixture and stir thoroughly to dissolve it, thus obtaining the ink mixture;

[0044] (3) Filter the ink mixture obtained in step (2) to obtain conductive ink, and store it in the dark and cold.

[0045] II. Polyamide 6 fabric modification:

[0046] (4) Prepare a reducing agent aqueous solution with a mass fraction of 9%-21%, stir to dissolve, and then add a polymer solution with a mass fraction of 6%-14% to prepare a modifier;

[0047] (5) Use a rolling mill to evenly roll the modifier onto the polyamide 6 fabric, two dips and two grapples to four dips and four grapples, pressure 2-3 kg, speed 2-5 r / min;

[0048] (6) After impregnation, dry at 50-70℃ and seal for storage to obtain modified polyamide 6 fabric;

[0049] III. Preparation of a conductive silver layer:

[0050] (7) Using screen printing, evenly brush conductive ink 2-4 times onto the surface of the modified polyamide 6 fabric to make the conductive ink evenly deposited on the fiber surface of the modified polyamide 6 fabric.

[0051] (8) The modified polyamide 6 fabric after coating is subjected to vacuum sintering to obtain a polyamide 6 high conductivity fabric with a uniformly covered conductive silver layer.

[0052] The precursor is any one of silver acetate, silver carbonate, silver citrate, and silver oxalate; the complexing agent is any one of isopropanolamine, ammonia, diethanolamine, and triethanolamine. In step (2), the solvent is ethanol, and the solvent accounts for 33.3% of the ink mixture by mass. The reducing agent is any one of ascorbic acid (AA), glucose, glutaraldehyde, and ethylene glycol; the polymer is any one of hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose, polyvinylpyrrolidone, and polyvinyl alcohol. The vacuum sintering temperature is 90℃~180℃, and the sintering time is 30min. The thickness of the conductive silver layer covering the surface of the polyamide 6 high-conductivity fabric used in textile-based electronic products is 8.7×10⁻⁶. -6 -4.3×10 -5 rice.

[0053] like Figure 1As shown, HPMC long molecules are intertwined to form a high-density complex network, with AA molecules embedded in the HPMC molecular chains and uniformly arranged. This facilitates the uniform formation of nano-silver. Numerous hydrophobic groups on the HPMC molecules point towards the air, thus spatially aligning them above the AA molecules. When conductive ink is dropped onto the fabric surface, ethanol molecules increase the ink's spreadability, and AA rapidly reacts with the silver amine complex to generate elemental silver and dehydroascorbic acid. During thermal sintering, the high temperature accelerates the redox reaction. Simultaneously, the thermal decomposition of the silver amine complex also generates elemental silver, CO2, CH4, H2O, and other byproducts. Under continuous heating conditions, AA oxidation products (such as dehydroascorbic acid, furfural and its derivatives) undergo a Maillard-like reaction with nylon-6 or amine-containing compounds, generating brown melanin. Furthermore, the breakage of some hydrogen bonds on the HPMC molecular chains reduces the HPMC molecular weight, and molecular condensation allows nano-silver to adhere to a larger area on the fabric surface. Therefore, it not only solves the interference of the complex composition of conductive ink and the capillary phenomenon of the fabric itself on the highly conductive nano-silver layer, but also prevents the ink from penetrating downwards and avoids the loss of silver because the ink can spread smoothly and form a continuous film between adjacent fibers and at the intersection of warp and weft yarns. Ultimately, it greatly reduces the resistivity of the fabric and significantly improves its conductivity.

[0054] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0055] Example 1:

[0056] A method for preparing a polyamide 6 highly conductive fabric for textile-based electronic products includes the following steps:

[0057] I. Preparation of conductive ink:

[0058] (1) Take a certain amount of silver carbonate and ammonia water and mix them. The molar ratio of silver carbonate to ammonia water is 2:1. After mixing, stir to obtain a mixed solution. Cool to room temperature and set aside.

[0059] (2) Add a certain amount of ethanol to the mixture and stir thoroughly to dissolve it, so as to obtain an ink mixture with an ethanol mass fraction of 33.3%;

[0060] (3) Filter the ink mixture obtained in step (2) using 20μm PTFE filter paper to obtain conductive ink. Store the filtered conductive ink in a brown bottle and refrigerate it.

[0061] II. Polyamide 6 fabric modification:

[0062] (4) Prepare a 9% glucose aqueous solution by stirring and dissolving, then add a 6% hydroxyethyl cellulose solution to prepare a modifier;

[0063] (5) Use a rolling mill to evenly roll the modifier onto the polyamide 6 fabric, dip and rub twice, pressure 2kg, speed 2r / min;

[0064] (6) After impregnation, the fabric is dried at 50°C and sealed for storage to obtain modified polyamide 6 fabric.

[0065] III. Preparation of a conductive silver layer:

[0066] (7) Using screen printing, a 120-mesh screen is used to uniformly brush conductive ink twice onto the surface of the modified polyamide 6 fabric, so that the conductive ink is uniformly deposited on the fiber surface of the modified polyamide 6 fabric.

[0067] (8) The modified polyamide 6 fabric after coating is placed in a vacuum drying oven for vacuum sintering treatment. The vacuum sintering treatment temperature is 90℃ and the sintering time is 30min to obtain a polyamide 6 high conductivity fabric with a uniformly covered conductive silver layer.

[0068] In this embodiment, the final polyamide 6 highly conductive fabric with a conductive silver layer covering its surface has a thickness of 8.7 × 10⁻⁶. -6 rice.

[0069] Example 2:

[0070] A method for preparing a polyamide 6 highly conductive fabric for textile-based electronic products includes the following steps:

[0071] I. Preparation of conductive ink:

[0072] (1) Take a certain amount of silver acetate and isopropanolamine and mix them. The molar ratio of silver acetate to isopropanolamine is 1:1.2. After mixing, stir to obtain a mixed solution, cool to room temperature and set aside.

[0073] (2) Add a certain amount of ethanol to the mixture and stir thoroughly to dissolve it, so as to obtain an ink mixture with an ethanol mass fraction of 33.3%;

[0074] (3) Filter the ink mixture obtained in step (2) using 20μm PTFE filter paper to obtain conductive ink. Store the filtered conductive ink in a brown bottle and refrigerate it.

[0075] II. Polyamide 6 fabric modification:

[0076] (4) Prepare an aqueous solution of ascorbic acid with a mass fraction of 15%, stir to dissolve, and then add a hydroxypropyl methylcellulose solution with a mass fraction of 10% to prepare a modifier;

[0077] (5) Use a rolling mill to evenly roll the modifier onto the polyamide 6 fabric, three dips and three slits, with a pressure of 2.5 kg and a rotation speed of 3 r / min;

[0078] (6) After impregnation, the fabric is dried at 60°C and sealed for storage to obtain modified polyamide 6 fabric;

[0079] III. Preparation of a conductive silver layer:

[0080] (7) Using screen printing, a 120-mesh screen is used to uniformly brush conductive ink three times onto the surface of the modified polyamide 6 fabric, so that the conductive ink is uniformly deposited on the fiber surface of the modified polyamide 6 fabric.

[0081] (8) The modified polyamide 6 fabric after coating is placed in a vacuum drying oven for vacuum sintering treatment. The vacuum sintering treatment temperature is 150℃ and the sintering time is 30min, so as to obtain a polyamide 6 high conductivity fabric with a uniformly covered conductive silver layer on the surface.

[0082] In this embodiment, the final polyamide 6 highly conductive fabric has a conductive silver layer covering a thickness of 1.2 × 10⁻⁶. -5 rice.

[0083] Example 3:

[0084] A method for preparing a polyamide 6 highly conductive fabric for textile-based electronic products includes the following steps:

[0085] I. Preparation of conductive ink:

[0086] (1) Take a certain amount of silver citrate and triethanolamine and mix them. The molar ratio of silver citrate to triethanolamine is 1:2. After mixing, stir to obtain a mixed solution. Cool to room temperature and set aside.

[0087] (2) Add a certain amount of ethanol to the mixture and stir thoroughly to dissolve it, so as to obtain an ink mixture with an ethanol mass fraction of 33.3%;

[0088] (3) Filter the ink mixture obtained in step (2) using 20μm PTFE filter paper to obtain conductive ink. Store the filtered conductive ink in a brown bottle and refrigerate it.

[0089] II. Polyamide 6 fabric modification:

[0090] (4) Prepare a glutaraldehyde aqueous solution with a mass fraction of 21%, stir to dissolve, and then add a polyvinylpyrrolidone solution with a mass fraction of 14% to prepare a modifier.

[0091] (5) Use a rolling mill to evenly roll the modifier onto the polyamide 6 fabric, four dips and four rolls, pressure 3 kg, speed 5 r / min;

[0092] (6) After impregnation, the fabric is dried at 70°C and sealed for storage to obtain modified polyamide 6 fabric;

[0093] III. Preparation of a conductive silver layer:

[0094] (7) Using screen printing, a 120-mesh screen is used to uniformly brush conductive ink 4 times on the surface of the modified polyamide 6 fabric, so that the conductive ink is uniformly deposited on the fiber surface of the modified polyamide 6 fabric.

[0095] (8) The modified polyamide 6 fabric after coating is placed in a vacuum drying oven for vacuum sintering treatment. The vacuum sintering treatment temperature is 180℃ and the sintering time is 30min, so as to obtain a polyamide 6 high conductivity fabric with a uniformly covered conductive silver layer on the surface.

[0096] In this embodiment, the final polyamide 6 highly conductive fabric has a conductive silver layer thickness of 4.3 × 10⁻⁶. -5 rice.

[0097] To investigate the effect of different concentrations of HPMC (2%, 4%, 6%, 8%, and 10%) on the conductivity of polyamide 6 highly conductive fabrics under the same conditions, examples with different concentrations of HPMC were conducted based on the technical solution of Example 2:

[0098] Example 4:

[0099] (1) Mix 5g silver acetate with 7g isopropanolamine, cool to room temperature, add 6g ethanol, stir thoroughly to dissolve, filter with 20μm PTFE filter paper, store the filtered ink in a brown bottle and refrigerate.

[0100] (2) Prepare a 15% AA aqueous solution, stir to dissolve, add a 10% HPMC solution to prepare a modifier, use a rolling mill to evenly roll the modifier onto the polyamide 6 fiber, three dips and three nips, pressure 2.5 kg, speed 3 r / min, and dry at 60℃ after dipping and nipping.

[0101] (3) Using a 120-mesh screen, the conductive ink is uniformly deposited on the modified polyamide 6 fiber and sintered at 150°C for 30 minutes in a vacuum drying oven.

[0102] Example 5:

[0103] (1) Mix 5g silver acetate with 7g isopropanolamine, cool to room temperature, add 6g ethanol, stir thoroughly to dissolve, filter with 20μm PTFE filter paper, store the filtered ink in a brown bottle and refrigerate.

[0104] (2) Prepare a 15% AA aqueous solution, stir to dissolve, add 8% HPMC solution to prepare a modifier, use a rolling mill to evenly roll the modifier onto polyamide 6 fiber, three dips and three rolls, pressure 2.5 kg, speed 3 r / min, and dry at 60℃ after dipping and rolling.

[0105] (3) Using a 120-mesh screen, the conductive ink is uniformly deposited on the modified polyamide 6 fiber and sintered at 150°C for 30 minutes in a vacuum drying oven.

[0106] Example 6:

[0107] (1) Mix 5g silver acetate with 7g isopropanolamine, cool to room temperature, add 6g ethanol, stir thoroughly to dissolve, filter with 20μm PTFE filter paper, store the filtered ink in a brown bottle and refrigerate.

[0108] (2) Prepare a 15% AA aqueous solution, stir to dissolve, add 6% HPMC solution to prepare a modifier, use a rolling mill to evenly roll the modifier onto polyamide 6 fiber, three dips and three nips, pressure 2.5 kg, speed 3 r / min, and dry at 60℃ after dipping and nipping.

[0109] (3) Using a 120-mesh screen, the conductive ink is uniformly deposited on the modified polyamide 6 fiber and sintered at 150°C for 30 minutes in a vacuum drying oven.

[0110] Example 7:

[0111] (1) Mix 5g silver acetate with 7g isopropanolamine, cool to room temperature, add 6g ethanol, stir thoroughly to dissolve, filter with 20μm PTFE filter paper, store the filtered ink in a brown bottle and refrigerate.

[0112] (2) Prepare a 15% AA aqueous solution, stir to dissolve, add 4% HPMC solution to prepare a modifier, use a rolling mill to evenly roll the modifier onto polyamide 6 fiber, three dips and three nips, pressure 2.5 kg, speed 3 r / min, and dry at 60℃ after dipping and nipping.

[0113] (3) Using a 120-mesh screen, the conductive ink is uniformly deposited on the modified polyamide 6 fiber and sintered at 150°C for 30 minutes in a vacuum drying oven.

[0114] Example 8:

[0115] (1) Mix 5g silver acetate with 7g isopropanolamine, cool to room temperature, add 6g ethanol, stir thoroughly to dissolve, filter with 20μm PTFE filter paper, store the filtered ink in a brown bottle and refrigerate.

[0116] (2) Prepare a 15% AA aqueous solution, stir to dissolve, add 2% HPMC solution to prepare a modifier, use a rolling mill to evenly roll the modifier onto polyamide 6 fiber, three dips and three nips, pressure 2.5 kg, speed 3 r / min, and dry at 60℃ after dipping and nipping.

[0117] (3) Using a 120-mesh screen, the conductive ink is uniformly deposited on the modified polyamide 6 fiber and sintered at 150°C for 30 minutes in a vacuum drying oven.

[0118] The performance test results of the polyamide 6 highly conductive fabrics obtained in Examples 4-8 of this invention are as follows:

[0119] The method for calculating the resistivity of the conductive silver layer prepared in this invention:

[0120] (1) Use a thickness gauge to measure the thickness of the silver-containing part and the non-silver-containing part of the polyamide 6 surface respectively. The difference is the thickness of the silver layer.

[0121] (2) Cut the fabric into 1cm×1cm squares, use a multimeter to measure the resistance at both ends of a unit length, and calculate the resistivity of the silver layer using the resistivity formula.

[0122] like Figure 2 As shown in the SEM image, the pores between adjacent fibers and between warp and weft yarns are almost completely blocked by the AA / HPMC coating. A continuous film is formed between adjacent fibers and at the intersections of warp and weft yarns, preventing ink from penetrating downwards and avoiding silver loss.

[0123] like Figure 3 As shown, the microstructure of the polyamide 6 fiber after printing ink and sintering reveals that the fiber surface is covered by a continuous and dense layer of silver nanoparticles. The silver nanoparticles are numerous and arranged in a staggered manner, which helps to reduce porosity and thus improve the conductivity of the silver nanoparticle layer.

[0124] like Figure 4-5 As shown, the results indicate that there is a distinct characteristic peak at around 368.2 eV, and the particulate matter on the fiber surface is silver nanoparticles, which exist in both elemental and silver oxide forms. Furthermore, the diffraction peaks of each crystal plane of the silver nanoparticles correspond one-to-one with the standard PDF card, indicating that it has an octahedral crystal structure dominated by the (111) crystal plane.

[0125] like Figure 6As shown, the original fabric and the fabric samples after sintering with printing ink are made of polyamide 6 fibers modified with 15% AA and different mass fractions of HPMC. With the increase of HPMC mass fraction, the exposed pores between fibers are significantly reduced. The nano-silver particles between adjacent fibers and at the interlacing points of warp and weft yarns gradually connect from a "discontinuous" state to form continuous pathways. When the HPMC mass fraction reaches 10%, the pores are almost completely covered. Figure 7 The figure shows the surface resistivity of polyamide 6 fiber printing ink modified by mixing 15% AA with different mass fractions of HPMC after sintering. At 2% and 4% HPMC content, the resistivity is extremely high because the silver nanoparticles at the fiber interlacing points are not connected, indicating an overall insulating state. At higher mass fractions, the silver particles interconnect to form conductive pathways, and the resistivity decreases rapidly, further decreasing with increasing silver nanoparticle content. At 10% HPMC content, the resistivity is on the order of 10 times that of pure silver. 3 This achieves the goal of high conductivity. Therefore, a mass fraction of 10% HPMC is optimal for this invention.

[0126] This method employs the simplest ink formulation, eliminating reducing agents and other additives from the ink, thus avoiding the impact of many chemicals in the ink on the conductivity of the nano-silver layer. Simultaneously, by modifying the surface of polyamide 6 fibers, the spreading and penetration of the ink on the fiber surface are controlled, achieving the preparation of a highly conductive silver layer. This method is simple to operate, has high chemical utilization, and does not cause environmental pollution.

[0127] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should be protected by the present invention.

Claims

1. A method for preparing a polyamide 6 highly conductive fabric for textile-based electronic products, characterized in that, Includes the following steps: I. Preparation of conductive ink: (1) Take a certain amount of precursor and complexing agent and mix them. The molar ratio of precursor to complexing agent is 2:1-1:

2. After mixing, stir to obtain a mixture. Cool to room temperature and set aside. (2) Add a certain amount of solvent to the mixture. The solvent is ethanol. The mass percentage of the solvent in the ink mixture is 33.3%. Stir thoroughly to dissolve and obtain the ink mixture. (3) Filter the ink mixture obtained in step (2) to obtain conductive ink, and store it in the dark and cold. II. Polyamide 6 fabric modification: (4) Prepare a reducing agent aqueous solution with a mass fraction of 9%-21%, stir to dissolve, and then add a polymer solution with a mass fraction of 6%-14% to prepare a modifier; (5) Use a rolling mill to evenly roll the modifier onto the polyamide 6 fabric, two dips and two grouts to four dips and four grouts, pressure 2-3 kg, speed 2-5 r / min; (6) After impregnation, dry at 50-70℃ and seal for storage to obtain modified polyamide 6 fabric; III. Preparation of a conductive silver layer: (7) Using screen printing, evenly brush conductive ink 2-4 times onto the surface of the modified polyamide 6 fabric to make the conductive ink evenly deposited on the fiber surface of the modified polyamide 6 fabric. (8) The modified polyamide 6 fabric after coating is subjected to vacuum sintering to obtain a polyamide 6 high conductivity fabric with a uniformly covered conductive silver layer. In step (1), the precursor is any one of silver acetate, silver carbonate, silver citrate, and silver oxalate, and the complexing agent is any one of isopropanolamine, ammonia, diethanolamine, and triethanolamine. In step (4), the reducing agent is any one of ascorbic acid, glucose, glutaraldehyde, and ethylene glycol, and the polymer is any one of hydroxypropyl methylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone, and polyvinyl alcohol.

2. The method for preparing polyamide 6 highly conductive fabric for textile-based electronic products according to claim 1, characterized in that: In step (1), the molar ratio of the precursor to the complexing agent is 1:1.

2.

3. The method for preparing polyamide 6 highly conductive fabric for textile-based electronic products according to claim 1, characterized in that: In step (4), the mass fraction of the reducing agent aqueous solution is 15%, and the mass fraction of the polymer solution is 10%.

4. The method for preparing polyamide 6 highly conductive fabric for textile-based electronic products according to claim 1, characterized in that: In step (5), the immersion rolling is controlled as three immersions and three rollings, with a pressure of 2.5 kg and a rotation speed of 3 r / min.

5. The method for preparing polyamide 6 highly conductive fabric for textile-based electronic products according to claim 1, characterized in that: In step (8), the vacuum sintering temperature is 90℃~180℃ and the sintering time is 30min.

6. A polyamide 6 highly conductive fabric for textile-based electronic products, characterized in that: It is prepared by the preparation method according to any one of claims 1-5.

7. The polyamide 6 highly conductive fabric for textile-based electronic products according to claim 6, characterized in that: The conductive silver layer covering the surface of the polyamide 6 highly conductive fabric has a thickness of 8.7 × 10⁻⁶. -6 -4.3×10 -5 rice.

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