Heterogeneous double-sided conductive knitted fabric and preparation method thereof

Abstract

According to the heterogeneous double-sided conductive knitted fabric and the preparation method thereof, graphene oxide, hydroxylated single-walled carbon nanotubes and a temperature-resistant auxiliary agent are adopted for compounding a conductive material, so that the conductive fabric has temperature resistance, and the weight of the conductive fabric is reduced. The preparation method of the cross-section hollow conductive yarn is simple and easy to operate, the conductive yarn is obtained by dipping the cross-section hollow yarn and then woven into the conductive fabric, the size carrying amount of the conductive fabric can be increased, and the size carrying uniformity of the conductive fabric is improved. According to the invention, the pure cotton hollow yarns are adopted to weave the heterogeneous double-sided knitted fabric, the hygroscopicity is good, the heat retention property is good, and the adhesion of a conductive solution can be increased by plasma etching. By means of the heterogeneous double-face structural design, one face is the temperature-resistant conductive face, the other face is the non-conductive face, the functional requirements of conductivity, temperature resistance and the like are met, the protection performance, the comfort performance and the like are provided, and the problem that a traditional conductive fabric is single in function is solved.

Description

Technical Field

[0001] The present invention relates to a preparation method of conductive fabric, in particular to a heterogeneous double-sided conductive knitted fabric and a preparation method thereof. Background Art

[0002] With the development of intelligent textiles, conductive fabrics have been widely used in the fields of wearable electronic devices, sensors, electromagnetic shielding, etc. However, most of the existing conductive fabrics have problems such as poor wearing performance and single function. Patent CN114808241 A uses metal yarn as the conductive material. Although it has good conductivity, the fabric has poor wearing performance and is relatively heavy; Patent CN 111719212 A uses a single conductive material, graphene, to prepare conductive fabric. The fabric has a single function and poor wearing performance, and cannot meet the multiple requirements of conductivity and protection comfort at the same time. Therefore, it is of great significance to develop a soft, skin-friendly and multifunctional heterogeneous double-sided conductive fabric. Summary of the Invention

[0003] Aiming at the above existing problems, the purpose of the present invention is to provide a preparation method of a heterogeneous double-sided conductive knitted fabric.

[0004] The technical solution of the present invention specifically includes the following steps:

[0005] A preparation method of a heterogeneous double-sided conductive knitted fabric includes the following steps:

[0006] Step 1: Prepare a temperature-resistant conductive solution by using graphene oxide dispersion, hydroxylated single-walled carbon nanotube dispersion, ammonia water and a temperature-resistant additive.

[0007] Step 2: After surface etching the cross-shaped hollow yarn, immerse it in the temperature-resistant conductive solution for 5-10 minutes. During immersion, ultrasonic treatment is carried out, and after immersion, drying is carried out.

[0008] Step 3: Repeat Step 2 for 3-7 times, and then reduce the yarn at a high temperature of 100-160 °C to obtain a cross-shaped hollow conductive yarn.

[0009] Step 4: Use the cross-shaped hollow conductive yarn and the cross-shaped hollow yarn to carry out double-sided knitting to form a heterogeneous double-sided conductive fabric, where the cross-shaped hollow yarn weaves the non-conductive surface of the heterogeneous double-sided conductive fabric, and the cross-shaped hollow conductive yarn weaves the conductive surface of the heterogeneous double-sided conductive fabric.

[0010] Further, Step 1 specifically includes the following steps:

[0011] Step 1.1: Add 0.5-2 parts by volume of a temperature-resistant additive to 10-20 parts by volume of graphene oxide dispersion, and ultrasonically stir for 10-30 minutes to obtain a mixture.

[0012] Step 1.2: Add 1.5 - 3 wt% ammonia water to the mixed solution from the previous step. After adjusting the pH value to 7 - 9, add 30 - 60 volume parts of hydroxylated single-walled carbon nanotube dispersion, and stir evenly by ultrasonic wave.

[0013] Step 1.3: Slowly add 1 - 3 drops of polyurethane to the solution obtained in the previous step, and continue to stir evenly to obtain a temperature-resistant conductive solution.

[0014] Furthermore, the temperature-resistant additive is 1 - 2 volume parts of 1 - 2 wt% nano-silica or 0.5 - 1 volume part of 0.5 - 1 wt% silane coupling agent KH-550.

[0015] Furthermore, the hollow cross-section of the cross-shaped cross-section hollow conductive yarn is cross-shaped.

[0016] Furthermore, the graphene oxide dispersion is 10 volume parts.

[0017] Furthermore, the preparation method of the cross-shaped cross-section hollow yarn in Step 2 is as follows:

[0018] After subjecting the combed cotton fibers to alkalization treatment (soaked in 18% NaOH solution at 25°C for 2 hours), dissolve them in ionic liquid to form a cellulose spinning solution with a concentration of 8 - 12 wt%.

[0019] Using a wet spinning device with a cross-shaped spinneret hole, extrude the cellulose spinning solution from the cross-shaped spinneret hole into a 15% sodium sulfate aqueous solution coagulation bath to finally obtain a cross-shaped cross-section pure cotton hollow yarn.

[0020] Furthermore, in Step 4, a circular knitting machine equipped with a high-low double-hole yarn guide is used for double-sided knitting. Among them, the high-position hole guides the cross-shaped cross-section hollow conductive yarn to perform knitting actions above the knitting needles to form the conductive surface of the heterogeneous double-sided conductive fabric; the low-position hole simultaneously guides the cross-shaped cross-section hollow yarn to perform knitting below the knitting needles to form the non-conductive surface of the heterogeneous double-sided conductive fabric.

[0021] A heterogeneous double-sided conductive knitted fabric is prepared by the above method.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. The present invention uses materials such as graphene oxide, hydroxylated single-walled carbon nanotubes, and temperature-resistant additives to prepare a temperature-resistant conductive solution, and immerses the cross-shaped cross-section hollow yarn in it to obtain a temperature-resistant conductive yarn, so that the temperature-resistant conductive yarn has temperature-resistant characteristics while maintaining conductive performance. Through the synergistic effect of the materials, it not only effectively resists the influence of external temperature changes on the test results of conductive performance, but also significantly reduces the overall weight of the conductive yarn, and has better comprehensive performance than the traditional metal conductive yarn scheme.

[0024] 2. The preparation method of the cross-shaped cross-section hollow conductive yarn of the present invention is simple and easy to operate. By impregnating the cross-shaped cross-section hollow yarn to obtain the conductive yarn and then weaving it into a conductive fabric, the sizing amount of the conductive fabric can be increased, and the sizing uniformity of the conductive fabric can be improved.

[0025] 3. The present invention uses pure cotton hollow yarn to weave a heterogeneous double-sided knitted fabric, which has good hygroscopicity and warmth retention. Plasma etching can also increase the adhesion of the conductive solution.

[0026] 4. The present invention uses a circular knitting machine with a high and low double-hole yarn guide to weave a heterogeneous double-sided structure. The obtained heterogeneous double-sided knitted fabric has an anti-temperature conductive surface on one side and a non-conductive surface on the other side, which not only meets the functional requirements such as conductivity and anti-temperature, but also provides properties such as protection and comfort, solving the problem of single function of traditional conductive fabrics. Brief Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the cross-section and side view of the cross-shaped cross-section hollow conductive yarn;

[0028] Figure 2 It is a schematic diagram of the structure of the heterogeneous double-sided conductive knitted fabric. Detailed Embodiments

[0029] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0030] Example 1: As Figure 1 shown, 1 ml of 1 wt% nano-silica (with a particle size of 50 nm) was added dropwise to 10 ml of graphene oxide dispersion liquid, and ultrasonic stirring was carried out for 10 - 30 minutes to ensure uniform compounding of nano-silica and graphene oxide;

[0031] 1.5 wt% ammonia water was added to the above solution to adjust the pH value to 7 - 9;

[0032] 30 ml of hydroxylated single-walled carbon nanotube dispersion liquid was added to the above solution, and ultrasonic stirring was carried out until it was uniform;

[0033] 1 drop of polyurethane was slowly added, and stirring was continued for 5 minutes. Observe the viscosity and dispersibility of the mixed solution to ensure no obvious agglomeration phenomenon, and obtain an anti-temperature conductive solution.

[0034] Surface etching was carried out on the cross-shaped cross-section hollow yarn to increase the surface roughness to make the conductive solution better adhere (the cross-shaped cross-section hollow yarn uses pure cotton hollow yarn);

[0035] The cross-shaped cross-section hollow yarn was impregnated in the anti-temperature conductive solution for 5 minutes, and ultrasonic treatment was carried out during impregnation;

[0036] After impregnation, a drying treatment is carried out. The drying temperature is 50 °C and the treatment time is 20 minutes; the impregnation-drying treatment is repeated 4 times;

[0037] Finally, reduction is carried out at a high temperature of 120 °C to obtain a cross-shaped cross-section hollow conductive yarn.

[0038] As Figure 2 shown, double-sided knitting is carried out using the cross-shaped cross-section hollow conductive yarn and the cross-shaped cross-section hollow yarn to form a heterogeneous double-sided conductive fabric. Among them, the cross-shaped cross-section hollow yarn weaves the non-conductive surface of the heterogeneous double-sided conductive fabric, and the cross-shaped cross-section hollow conductive yarn weaves the conductive surface of the heterogeneous double-sided conductive fabric, and finally a heterogeneous double-sided conductive knitted fabric is formed.

[0039] Example 2: 2 ml of 1 wt% nano-silica (with a particle size of 45 nm) is added dropwise to 15 ml of graphene oxide dispersion liquid, and ultrasonic stirring is carried out for 20 minutes to ensure the uniform composite of nano-silica and graphene oxide;

[0040] 2 wt% ammonia water is added to the above solution to adjust the pH value to 7-9;

[0041] 45 ml of hydroxylated single-walled carbon nanotube dispersion liquid is added to the above solution, and ultrasonic stirring is carried out until it is uniform;

[0042] 2 drops of polyurethane are slowly added, and stirring is continued for 10 minutes. Observe the viscosity and dispersibility of the mixed solution to ensure that there is no obvious agglomeration phenomenon to obtain a temperature-resistant conductive solution.

[0043] Surface etching is carried out on the cross-shaped cross-section hollow yarn to increase the surface roughness so that the conductive solution adheres better (the cross-shaped cross-section hollow yarn uses pure cotton hollow yarn);

[0044] The cross-shaped cross-section hollow yarn is impregnated into the temperature-resistant conductive solution for 10 minutes, and ultrasonic treatment is carried out during impregnation;

[0045] After impregnation, a drying treatment is carried out. The drying temperature is 80 °C and the treatment time is 30 minutes; the impregnation-drying treatment is repeated 3 times;

[0046] Finally, reduction is carried out at a high temperature of 140 °C to obtain a cross-shaped cross-section hollow conductive yarn.

[0047] Double-sided knitting is carried out using the cross-shaped cross-section hollow conductive yarn and the cross-shaped cross-section hollow yarn to form a heterogeneous double-sided conductive fabric. Among them, the cross-shaped cross-section hollow yarn weaves the non-conductive surface of the heterogeneous double-sided conductive fabric, and the cross-shaped cross-section hollow conductive yarn weaves the conductive surface of the heterogeneous double-sided conductive fabric, and finally a heterogeneous double-sided conductive knitted fabric is formed.

[0048] Example 3: Add 1 ml of 1 wt% silane coupling agent KH-550 to 20 ml of graphene oxide dispersion, and ultrasonically stir for 10 - 30 minutes to ensure the uniform compounding of silane coupling agent KH-550 and graphene oxide;

[0049] Add 3 wt% ammonia water to the above solution to adjust the pH value to 7 - 9;

[0050] Add 60 ml of hydroxylated single-walled carbon nanotube dispersion to the above solution and ultrasonically stir until uniform;

[0051] Slowly add 3 drops of polyurethane and continue stirring for 10 minutes. Observe the viscosity and dispersibility of the mixed solution to ensure no obvious agglomeration phenomenon, and obtain a temperature-resistant conductive solution.

[0052] Etch the surface of the hollow yarn with a cross-shaped cross-section to increase the surface roughness to make the conductive solution adhere better (the hollow yarn with a cross-shaped cross-section uses pure cotton hollow yarn);

[0053] Immerse the hollow yarn with a cross-shaped cross-section into the temperature-resistant conductive solution for 10 minutes, and perform ultrasonic treatment during immersion;

[0054] After immersion, perform a drying treatment. The drying temperature is 80 °C and the treatment time is 40 minutes; Repeat the immersion-drying treatment 7 times;

[0055] Finally, perform reduction at a high temperature of 160 °C to obtain a hollow conductive yarn with a cross-shaped cross-section.

[0056] Use the hollow conductive yarn with a cross-shaped cross-section and the hollow yarn with a cross-shaped cross-section for double-sided weaving to form a heterogeneous double-sided conductive fabric. Among them, the hollow yarn with a cross-shaped cross-section weaves the non-conductive surface of the heterogeneous double-sided conductive fabric, and the hollow conductive yarn with a cross-shaped cross-section weaves the conductive surface of the heterogeneous double-sided conductive fabric, and finally forms a heterogeneous double-sided conductive knitted fabric.

[0057] Example 4: Ultrasonically stir 20 ml of graphene oxide dispersion for 10 - 30 minutes;

[0058] Add 3 wt% ammonia water to the above solution to adjust the pH value to 7 - 9;

[0059] Add 60 ml of hydroxylated single-walled carbon nanotube dispersion to the above solution and ultrasonically stir until uniform;

[0060] Slowly add 3 drops of polyurethane and continue stirring for 10 minutes. Observe the viscosity and dispersibility of the mixed solution to ensure no obvious agglomeration phenomenon, and obtain a conductive solution.

[0061] Etch the surface of the hollow yarn with a cross-shaped cross-section to increase the surface roughness to make the conductive solution adhere better (the hollow yarn with a cross-shaped cross-section uses pure cotton hollow yarn);

[0062] Immerse the hollow yarn with a cross-shaped cross-section in a conductive solution for 10 minutes, and perform ultrasonic treatment during immersion;

[0063] After immersion, perform a drying treatment. The drying temperature is 80 °C and the treatment time is 40 minutes; Repeat the immersion-drying treatment 7 times;

[0064] Finally, perform reduction at a high temperature of 160 °C to obtain a hollow conductive yarn with a cross-shaped cross-section.

[0065] Use the hollow conductive yarn with a cross-shaped cross-section and the hollow yarn with a cross-shaped cross-section for double-sided weaving to form a heterogeneous double-sided conductive fabric. Among them, the hollow yarn with a cross-shaped cross-section weaves the non-conductive surface of the heterogeneous double-sided conductive fabric, and the hollow conductive yarn with a cross-shaped cross-section weaves the conductive surface of the heterogeneous double-sided conductive fabric, and finally forms a heterogeneous double-sided conductive knitted fabric.

[0066] Comparative Example 1: Gradually add 1 ml of 1 wt% nano-silica (with a particle size of 50 nm) to 10 ml of graphene oxide dispersion liquid, and perform ultrasonic stirring for 10 - 30 minutes to ensure uniform compounding of nano-silica and graphene oxide;

[0067] Add 1.5 wt% ammonia water to the above solution to adjust the pH value to 7 - 9;

[0068] Add 30 ml of hydroxylated single-walled carbon nanotube dispersion liquid to the above solution, and perform ultrasonic stirring until uniform;

[0069] Slowly add 1 drop of polyurethane, and continue stirring for 5 minutes. Observe the viscosity and dispersibility of the mixed solution to ensure no obvious agglomeration phenomenon, and obtain a temperature-resistant conductive solution.

[0070] Perform surface etching on the circular hollow yarn to increase the surface roughness to make the conductive solution adhere better;

[0071] Immerse the circular hollow yarn in the temperature-resistant conductive solution for 5 minutes, and perform ultrasonic treatment during immersion;

[0072] After immersion, perform a drying treatment. The drying temperature is 50 °C and the treatment time is 20 minutes; Repeat the immersion-drying treatment 4 times;

[0073] Finally, perform reduction at a high temperature of 120 °C to obtain a circular hollow conductive yarn.

[0074] Use the circular hollow conductive yarn and the circular hollow yarn for double-sided weaving to form a heterogeneous double-sided conductive fabric. Among them, the circular hollow yarn weaves the non-conductive surface of the heterogeneous double-sided conductive fabric, and the circular hollow conductive yarn weaves the conductive surface of the heterogeneous double-sided conductive fabric, and finally forms a heterogeneous double-sided conductive knitted fabric.

[0075] Comparative Example 2: 1 ml of 1 wt% nano-silica (with a particle size of 50 nm) was added dropwise to 10 ml of graphene oxide dispersion, and ultrasonic stirring was carried out for 10 - 30 minutes to ensure uniform composite of nano-silica and graphene oxide;

[0076] 1.5 wt% ammonia water was added to the above solution to adjust the pH value to 7 - 9;

[0077] 30 ml of hydroxylated single-walled carbon nanotube dispersion was added to the above solution, and ultrasonic stirring was carried out until it was uniform;

[0078] 1 drop of polyurethane was slowly added, and stirring was continued for 5 minutes. The viscosity and dispersibility of the mixed solution were observed to ensure no obvious agglomeration phenomenon, and a temperature-resistant conductive solution was obtained.

[0079] The surface of the triangular hollow yarn was etched to increase the surface roughness to make the conductive solution adhere better;

[0080] The triangular hollow yarn was immersed in the temperature-resistant conductive solution for 5 minutes, and ultrasonic treatment was carried out during immersion;

[0081] After immersion, drying treatment was carried out. The drying temperature was 50 °C, and the treatment time was 20 minutes; the immersion-drying treatment was repeated 4 times;

[0082] Finally, reduction was carried out at a high temperature of 120 °C to obtain a triangular hollow conductive yarn.

[0083] The triangular hollow conductive yarn and the flat hollow yarn were used for double-sided weaving to form a heterogeneous double-sided conductive fabric. Among them, the triangular hollow yarn weaved the non-conductive side of the heterogeneous double-sided conductive fabric, and the triangular hollow conductive yarn weaved the conductive side of the heterogeneous double-sided conductive fabric, and finally a heterogeneous double-sided conductive knitted fabric was formed.

[0084] In summary, in order to verify the electrical properties of the heterogeneous double-sided conductive knitted fabric prepared by the present invention, the conductive properties of the heterogeneous double-sided conductive knitted fabrics obtained in Examples 1 - 3 and Comparative Examples 1 - 2 were tested respectively, and the specific results are shown in Table 1.

[0085] Table 1

[0086]

[0087] It can be found from Table 1 that in Examples 1 - 3 of the present invention, with the increase of the content of the conductive solution, the surface resistance gradually decreased from 18 Ω / sq to 15 Ω / sq, and the conductive layer coverage rate increased from 91% to 94%. Moreover, Example 3 showed the best comprehensive performance (response time 50 ms, resistance change rate +7.8% after washing), and the high-content solution could effectively construct a dense conductive network.

[0088] Example 4 (without adding temperature-resistant additives) has the same conductive layer coverage as Example 3, but its surface resistance increases to 20 Ω / sq, and the corresponding time is 54 ms. This is because the temperature-resistant additives can improve the conductive stability by suppressing the influence of temperature changes on the conductivity.

[0089] Comparing the yarn hollow structures of Example 1, Comparative Example 1, and Comparative Example 2, the surface resistance of the heterogeneous double-sided conductive fabric prepared using the cross-shaped pure cotton hollow conductive yarn is reduced to 18 Ω / sq, the conductive layer coverage is increased to 91%, and the response time is reduced to 55 ms. Moreover, the resistance change rate after 50 washes and the resistance attenuation rate after 500 bends are both reduced. This is because the amount of sizing on the cross-shaped pure cotton hollow yarn used in Example 1 is relatively large when impregnated into the conductive solution, and the effective contact area between the yarn and the conductive solution is large, thereby improving the conductivity of the heterogeneous double-sided conductive fabric.

[0090] The above are examples of the best implementation modes of the present invention. The parts not described in detail are common general knowledge in the art. The protection scope of the present invention is subject to the content of the claims, and any equivalent transformation based on the technical inspiration of the present invention is also within the protection scope of the present invention.

Claims

1. A preparation method of a heterogeneous double-sided conductive knitted fabric, characterized in that, It includes the following steps: Step 1: Prepare a temperature-resistant conductive solution by using a graphene oxide dispersion, a hydroxylated single-walled carbon nanotube dispersion, ammonia water, and a temperature-resistant additive. Step 2: After surface etching the hollow yarn with a cross-shaped cross-section, immerse it in the temperature-resistant conductive solution for 5 - 10 minutes. During immersion, perform ultrasonic treatment, and after immersion, conduct drying. Step 3: Repeat Step 2 for 3 - 7 times, and then reduce the yarn at a high temperature of 100 - 160 °C to obtain a hollow conductive yarn with a cross-shaped cross-section. Step 4: Use the hollow conductive yarn with a cross-shaped cross-section and the hollow yarn with a cross-shaped cross-section to perform double-sided knitting to form a heterogeneous double-sided conductive fabric. Among them, the hollow yarn with a cross-shaped cross-section weaves the non-conductive surface of the heterogeneous double-sided conductive fabric, and the hollow conductive yarn with a cross-shaped cross-section weaves the conductive surface of the heterogeneous double-sided conductive fabric.

2. The preparation method of the heterogeneous double-sided conductive knitted fabric according to claim 1, characterized in that The specific steps of Step 1 include the following steps: Step 1.1: Add 0.5 - 2 volume parts of the temperature-resistant additive to 10 - 20 volume parts of the graphene oxide dispersion, and perform ultrasonic stirring for 10 - 30 minutes to obtain a mixed solution. Step 1.2: Add 1.5 - 3 wt% ammonia water to the mixed solution in the previous step. After adjusting the pH value to 7 - 9, then add 30 - 60 volume parts of the hydroxylated single-walled carbon nanotube dispersion, and stir evenly by ultrasonic treatment. Step 1.3: Slowly add 1 - 3 drops of polyurethane to the solution obtained in the previous step, and continue to stir evenly to obtain the temperature-resistant conductive solution.

3. The preparation method of the heterogeneous double-sided conductive knitted fabric according to claim 1, wherein The temperature-resistant additive is 1 - 2 volume parts of 1 - 2 wt% nano-silica or 0.5 - 1 volume parts of 0.5 - 1 wt% silane coupling agent KH-550.

4. The preparation method of the heterogeneous double-sided conductive knitted fabric according to claim 1, wherein, The hollow cross-section of the hollow conductive yarn with a cross-shaped cross-section is cross-shaped.

5. The preparation method of the heterogeneous double-sided conductive knitted fabric according to claim 1, characterized in that, The graphene oxide dispersion is 10 volume parts.

6. The preparation method of the heterogeneous double-sided conductive knitted fabric according to claim 1, wherein, The preparation method of the hollow yarn with a cross-shaped cross-section in Step 2 is as follows: After subjecting the combed cotton fibers to alkalization treatment, dissolve them in an ionic liquid to form a cellulose spinning solution with a concentration of 8 - 12 wt%. Adopt a wet spinning device with a cross-shaped spinneret hole, extrude the cellulose spinning solution from the cross-shaped spinneret hole into a 15% sodium sulfate aqueous solution coagulation bath, and finally obtain a pure cotton hollow yarn with a cross-shaped cross-section.

7. The preparation method of the heterogeneous double-sided conductive knitted fabric according to claim 1, wherein, In Step 4, use a circular knitting machine equipped with a high and low double-hole yarn guide to perform double-sided knitting. Among them, the high-position hole guides the hollow conductive yarn with a cross-shaped cross-section to perform knitting actions above the knitting needles to form the conductive surface of the heterogeneous double-sided conductive fabric; the low-position hole simultaneously guides the hollow yarn with a cross-shaped cross-section to perform knitting below the knitting needles to form the non-conductive surface of the heterogeneous double-sided conductive fabric.

8. A heterogeneous double-sided conductive knitted fabric, characterized in that, Prepared by the method according to any one of claims 1 - 7.

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