US20190203383A1

US20190203383A1 - Conductive elastic fiber and method for fabricating the same

Info

Publication number: US20190203383A1
Application number: US15/858,512
Authority: US
Inventors: Chung-Yang Chuang; Kai-Jen Hsiao; Chih-Lung Chen; Jing-Wen Tang
Original assignee: Industrial Technology Research Institute ITRI
Current assignee: Industrial Technology Research Institute ITRI
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2019-07-04

Abstract

A conductive elastic fiber and a method for fabricating the conductive elastic fiber are provided. The method for fabricating the conductive elastic fiber includes following steps. A first solution is provided, where the first solution includes an elastic polymer dissolved in a first solvent, wherein the weight ratio of the elastic polymer to the first solvent is from 5:95 to 20:80. A second solution is provided, where the second solution includes a conductive material dispersed in a second solvent, wherein the weight ratio of the conductive material to the second solvent is from 5:95 to 20:80. Next, a wet spinning process employing the first solution and the second solution is performed to obtain the conductive elastic fiber.

Description

TECHNICAL FIELD

The disclosure relates to a conductive elastic fiber and a method for fabricating the conductive elastic fiber.

BACKGROUND

In the textile industry, conductive fibers are the key material for fabricating smart textiles and wearable devices. In general, metal fibers are main conventional conductive fibers and exhibits sufficient strength and rigidity. Since the metal fibers exhibit poor elasticity and stretchability, textiles made of the metal fibers has a low degree of wearing comfort.
Conventional fibers applied in textiles have a high degree of wearing comfort, but do not have electrical conductivity since the chemical structure of the conventional fibers does not have conjugating moiety. In order to improve the electrical conductivity, carbon black is used to blend with polymer via extrusion molding to form pellets for spinning. The obtained fiber prepared from the aforementioned process exhibits poor strength due to the excessively large addition amount of carbon black. In addition, due to the phase separation caused by the poor compatibility between the carbon black and the polymer, the electrical conductivity of the fiber is difficult to be improved by means of the addition of carbon black. Furthermore, in another process for increasing the electrical conductivity of the conventional fiber, a metal layer is formed on the fiber via evaporation or surface chemical deposition to improve the electrical conductivity of the fiber. Since the metal layer exhibits poor stretchability, the fiber is apt to loss electrical conductivity after stretching.
Therefore, a novel conductive fiber and a method for preparing the same are required to solve the aforementioned problems.

SUMMARY

According to embodiments of the disclosure, the disclosure provides a method for fabricating the conductive elastic fiber. The method includes providing a first solution, wherein the first solution includes an elastic polymer dissolved in a first solvent. The weight ratio of the elastic polymer to the first solvent is from 5:95 to 20:80. A second solution is provided, wherein the second solution includes a conductive material dispersed in a second solvent. The conductive material to the second solvent is from 5:95 to 20:80. Next, a wet spinning process employing the first solution and the second solution is performed, obtaining the conductive elastic fiber.
According to another embodiment of the disclosure, the disclosure provides a conductive elastic fiber. The conductive elastic fiber includes an elastic polymer and a conductive material, wherein the weight ratio of the elastic polymer and the conductive material from 1:2 to 3:1.
A detailed description is given in the following embodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a conductive elastic fiber according to an embodiment of the disclosure:

FIG. 2 is a cross-sectional view of a conductive elastic fiber according to some embodiments of the disclosure: and

FIG. 3 is a cross-sectional view of a conductive elastic fiber according to some embodiments of the disclosure.

DETAILED DESCRIPTION

The conductive elastic fiber and the method for fabricating the conductive elastic fiber of the disclosure are described in detail in the following description. In the following detailed description, for purposes of explanation, numerous specific details and embodiments are set forth in order to provide a thorough understanding of the present disclosure. The specific elements and configurations described in the following detailed description are set forth in order to clearly describe the present disclosure. It will be apparent, however, that the exemplary embodiments set forth herein are used merely for the purpose of illustration, and the inventive concept may be embodied in various forms without being limited to those exemplary embodiments. In addition, the drawings of different embodiments may use like and/or corresponding numerals to denote like and/or corresponding elements in order to clearly describe the present disclosure. However, the use of like and/or corresponding numerals in the drawings of different embodiments does not suggest any correlation between different embodiments. In the drawings, the size, shape, or thickness of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The disclosure will be described with respect to particular embodiments and with reference to certain drawings but the disclosure is not limited thereto.
The disclosure provides a conductive elastic fiber and a method for fabricating the conductive elastic fiber. The conductive material is uniformly dispersed in the elastic polymer or combined with the elastic polymer via an adhesive. After subjecting a wet spinning process, a conductive elastic fiber, with a solid, hollow or core-shell structure, having electrical conductivity can be prepared. Besides electrical conductivity, the conductive elastic fiber further exhibits improved stretchability and mechanical strength.
According to embodiments of the disclosure, the disclosure provides a method for fabricating the conductive elastic fiber. The method includes providing a first solution, wherein the first solution includes an elastic polymer dissolved in a first solvent. The weight ratio of the elastic polymer to the first solvent is about from 5:95 to 20:80 (such as 7:93, 10:90, 12:88, 15:85, or 17:83). A second solution is provided, wherein the second solution includes a conductive material dispersed in a second solvent. The weight ratio of the conductive material to the second solution about from 5:95 to 20:80 (such as 7:93, 10:90, 12:88, 15:85, or 17:83). A wet spinning process employing the first solution and the second solution is performed to obtain the conductive elastic fiber.
According to embodiments of the disclosure, the first solution can have a solid content of about from 5 wt % to 20 wt %; and, the second solution can have a solid content of about from 5 wt % to 20 wt %.
According to embodiments of the disclosure, the elastic polymer can be polyurethane, polyester, styrene-butadiene-styrene resin (SBS), nitrile butadiene rubber (NBR) or a combination thereof. In addition, according to some embodiments of the disclosure, the elastic polymer can have a weight average molecular weight from 10,000 g/mol to 500,000 g/mol), such as 50,000 g/mol to 300,000 g/mol.
According to embodiments of the disclosure, the conductive material can be conductive powder. In particular, the conductive powder has an aspect ratio from about 1:2 to 2:1 (such as 15:2, 1:1, or 2:1.5), and the conductive powder can have a particle size from about 0.1 μm to 10 μm (such as 0.5 μm). According to some embodiments of the disclosure, the conductive material can be rod-like conductive material or conductive wire. In particular, the rod-like conductive material or conductive wire has an aspect ratio (aspect ratio)from about 2:1 to 100:1 (such as 5:1 10:1. 20:1, 30:1, 50:1 or 80:1). The width of the rod-like conductive material or conductive wire can be from about 10 nm to 0.2 μm (such as 70 nm). According to embodiments of the disclosure, the conductive material can be a metal or an alloy of the metal, wherein the metal can be gold, silver, copper, aluminum, nickel, or an alloy thereof. According to some embodiments of the disclosure, the conductive material can be transparent conductive material, such as indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), or indium gallium zinc oxide (IGZO). For example, the conductive material can be gold, silver, copper, aluminum, nickel, gold-containing alloy, silver-containing alloy, copper-containing alloy, aluminum-containing alloy, nickel-containing alloy, indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), or indium gallium zinc oxide (IGZO) or a combination thereof
According to embodiments of the disclosure, the first solvent and the second solvent can be the same or different. For example, the first solvent and the second solvent can be independently dimethylformamide, dimethylacetamide, dimethylsulfone, tetrahydrofuran, dichloromethane, chloroform, ethylene carbonate, propylene carbonate, or methylethyl ketone. According to embodiments of the disclosure, the first solvent can be miscible with the second solvent.
According to embodiments of the disclosure, the second solution further includes an adhesive, wherein the adhesive is dissolved in the second solvent. The weight ratio of the conductive material to the adhesive can be from 1:2 to 50:1, such as 1:1, 3:1, 5:1, 10:1, 20:1, 30:1, or 40:1. According to embodiments of the disclosure, the conductive material can combine with the elastic polymer without inducing phase separation, by means of the addition of the adhesive. According to some embodiments of the disclosure, the adhesive can be a polymer or oligomer, wherein the weight average molecular weight of the adhesive can be from 10,000 g/mol to 500,000 g/mol, such as from 50,000 to 300,000. According to some embodiments of the disclosure, the adhesive can be the elastic polymer. According to some embodiments of the disclosure, the weight average molecular weight of the adhesive is less than the weight average molecular weight of the elastic polymer. According to embodiments of the disclosure, the adhesive can be polyurethane, styrene-butadiene-styrene resin (SBS), nitrile butadiene rubber (NBR) or a combination thereof.
According to embodiments of the disclosure, the disclosure provides a conductive elastic fiber. The conductive elastic fiber includes an elastic polymer and a conductive material, wherein the weight ratio of the elastic polymer and the conductive material is about from 1:2 to 3:1, such as 1:1, 1.5:1, 2:1, or 2.5:1. When the weight ratio of the elastic polymer and the conductive material is too low, the obtained conductive elastic fiber exhibits reduced stretchability and mechanical strength. When the weight ratio of the elastic polymer and the conductive material is too high, the obtained conductive elastic fiber exhibits high electrical resistance. According to embodiments of the disclosure, the conductive elastic fiber of the disclosure can have a fiber fineness from 0.05 mm to 2 mm (such as from 0.1 mm to 1.5 mm, from 0.2 mm to 1.2 mm, from 0.3 mm to 1.0 mm, from 0.4 mm to 0.9 mm, or from 0.5 mm to 0.8 mm), and the conductive elastic fiber of the disclosure can have a resistivity about from 0.1 Ω/cm to 1000 Ω/cm (such as from 0.1 Ω/cm to 500 Ω/cm, from 0.1 Ω/cm to 300 Ω/cm, from 0.1 Ω/cm to 200 Ω/cm), from 0.1 Ω/cm to 100 Ω/cm, from 0.1 Ω/cm to 60/Ω/cm, from 0.1 Ω/cm to 50/Ω/cm, from 0.1 Ω/cm to 10 Ω/cm, from 0.1 Ω/cm to 3 Ω/cm, or from 0.3 Ω/cm to 1 Ω/cm).
According to embodiments of the disclosure. FIG. 1 is a cross-sectional view of a conductive elastic fiber 10 according to an embodiment of the disclosure. As shown in FIG. 1, the conductive elastic fiber 10 can be a solid conductive elastic fiber, and the conductive elastic fiber 10 can consist of elastic polymer 12 and conductive material 14. According to embodiments of the disclosure, the conductive elastic fiber 10 can consist of elastic polymer 12, conductive material 14, and adhesive (not shown). According to embodiments of the disclosure, the weight ratio of the elastic polymer and the conductive material is about 1:2 to 3:1, such as 1:1, 1.5:1, 2:1, or 2.5:1.
According to embodiments of the disclosure, the method for fabricating the solid conductive elastic fiber as show in FIG. 1 can include following steps. First, the aforementioned first solution and the aforementioned second solution are provided. Next, the first solution with the second solution are mixed, obtaining a third solution. The weight ratio of the first solution to the second solution is about 1:2 to 3:1. It should be noted that, the first solvent is miscible with the second solvent, and the elastic polymer should be soluble in the second solvent. Next, a wet spinning process employing the third solution served as a spinning solution is performed, obtaining the solid conductive elastic fiber. According to other embodiments of the disclosure, the second solution can further include the aforementioned adhesive, wherein the adhesive is dissolved in the second solvent. The weight ratio of the conductive material to the adhesive can be from 1:2 to 50:1, such as 1:1, 3:1, 5:1, 10:1. 20:1, 30:1. or 40:1. In addition, the adhesive should be soluble in the first solvent.
According to embodiments of the disclosure, FIG. 2 is a cross-sectional view of a conductive elastic fiber 10 according to some embodiments of the disclosure. As shown in FIG. 2, the conductive elastic fiber 10 can be a hollow conductive elastic fiber, wherein the hollow conductive elastic fiber includes a hollow portion 11 and a shell portion 13. The shell portion 13 consists of an elastic polymer 12 and a conductive material 14. According to embodiments of the disclosure, the shell portion 13 consists of the elastic polymer 12, the conductive material 14 and an adhesive (not shown). According to embodiments of the disclosure, the volume ratio of the hollow portion 11 to the shell portion 13 can be about 3:1 to 1:3. According to embodiments of the disclosure, the weight ratio of the elastic polymer and the conductive material is about 1:2 to 3:1, such as 1:1, 1.5:1, 2:1, or 2.5:1.
According to embodiments of the disclosure, the method for fabricating the solid conductive elastic fiber as show in FIG. 2 can include following steps. First, the aforementioned first solution and the aforementioned second solution are provided. Next, the first solution with the second solution are mixed, obtaining a third solution. The weight ratio of the first solution and the second solution can be about 1:2 to 3:1. It should be noted that the first solvent is miscible with the second solvent, and the elastic polymer should be soluble in the second solvent. Next, a wet spinning process employing a spinning device with two spinning nozzles is performed, wherein water is provided to serve as a spinning solution of the inner spinning nozzle and the third solution serves as a spinning solution of the outer spinning nozzle, obtaining the hollow conductive elastic fiber. According to other embodiments of the disclosure, the second solution can further include the aforementioned adhesive, wherein the adhesive is dissolved in the second solvent. The weight ratio of the conductive material to the adhesive can be from 1:2 to 50:1, such as 1:1, 3:1, 5:1, 10:1, 20:1, 30:1, or 40:1. in addition, the adhesive should be soluble in the first solvent.
According to embodiments of the disclosure. FIG. 3 is a cross-sectional view of a conductive elastic fiber 10 according to some embodiments of the disclosure. As shown in FIG. 3, the conductive elastic fiber 10 can be a conductive elastic fiber with a core-shell structure, wherein the core-shell structure consist of a core portion 15 and a shell portion 17. The core portion 15 includes the elastic polymer, and the shell portion includes the conductive material 14 and the adhesive 16. According to embodiments of the disclosure, the core portion 15 consists of the elastic polymer, and the shell portion 17 consists of the conductive material 14 and the adhesive 16. According to embodiments of the disclosure, in the core-shell structure of the conductive elastic fiber, the volume ratio of the core portion 15 to the shell portion 17 can be about 3:1 to 1:3. Herein, the weight ratio of the conductive material to the adhesive can be about 1:2 to 3:1, such as 1.5:2, 1:1, 1.5: 1, 2:1, or 2.5:1. When the weight ratio of the conductive material to the adhesive is too low, the obtained conductive elastic fiber exhibits high electrical resistance. When the weight ratio of the conductive material to the adhesive is too high, the shell portion of the conductive elastic fiber is apt to separate from the core portion of the conductive elastic fiber.
According to embodiments of the disclosure, the method for preparing the conductive elastic fiber with a core-shell structure as shown in FIG. 3 can include following steps. First, the aforementioned first solution and the aforementioned second solution are provided. Next, a wet spinning process employing a spinning device with two spinning nozzles is performed, wherein the first solution is provided to serve as a spinning solution of the inner spinning nozzle and the second solution serves as a spinning solution of the outer spinning nozzle, obtaining the conductive elastic fiber with a core-shell structure. According to other embodiments of the disclosure, the first solution includes the aforementioned elastic polymer dissolved in the first solvent, wherein the weight ratio of the elastic polymer to the first solvent can be about from 5:95 to 20:80 (such as 7:93, 10:90. 12:88. 15:85. or 17:83). The second solution includes the aforementioned conductive material dispersed in the second solvent, and the second solution includes aforementioned adhesive dissolved in the second solvent, wherein the weight ratio of the sum conductive material and the adhesive to the second solution is about from 5:95 to 20:80 (such as 7:93. 10:90, 12:88. 15:85, or 17:83). According to embodiments of the disclosure, the weight ratio of the conductive material to the adhesive can be about from 1:2 to 50:1, such as 1:1, 3:1, 5:1, 10:1, 20:1, 30:1, or 40:1. According to embodiments of the disclosure, the first solution consists of the elastic polymer and the first solvent. The second solution consists of the conductive material and the adhesive. According to embodiments of the disclosure, the first solution has a solid content of about from 5 wt % to 20 wt %. The second solution has a solid content of about from 5 wt % to 20 wt %.
Below, exemplary embodiments will be described in detail so as to be easily realized by a person having ordinary knowledge in the art. The inventive concept may be embodied in various forms without being limited to the exemplary embodiments set forth herein. Descriptions of well-known parts are omitted for clarity.
Preparation of conductive elastic fiber

EXAMPLE 1

Polyurethane (serving as the elastic polymer) (sold by Formosa Asahi spandex, with a trade number of Roica) was dissolved in N,N-dimethyl acetamide, obtaining a first solution (with a solid content of 15 wt %). In addition, silver nanowires (serving as the conductive material) (having a diameter of 60 nm and a length of 22 μm) were dispersed in N,N-dimethyl acetamide, obtaining a second solution (with a solid content of 15 wt %). Next, the first solution was mixed with the second solution (the weight ratio of the first solution to the second solution was 1:1). Next, after stirring for 120 min at 60° C. (with a stirring rate of 200 rpm), silver nanowires were sufficiently dispersed in the mixture (including polyurethane). Next, the result served as a spinning solution. A wet spinning process employing a spinning device was performed, obtaining solid Conductive elastic fiber (1). The spinning process was performed under the following conditions: the spinning nozzle had a diameter of 0.7 mm: the spinning temperature was about 60° C.; the spinning nozzle had a liquid flow speed of Zee/min; the spinning speed of the spinning process was 6.5 m/min; water served as the coagulating bath; and, the temperature of the coagulating bath was 40° C. Next, the fiber fineness of Conductive elastic fiber (1) was measured with a scanning electron microscope (JEOL JSM-6480), and the resistivity of Conductive elastic fiber (1) was measured using a resistance meter (RM3544, made by Hioki Co., Ltd.). The results are shown in Table 1.

EXAMPLE 2

Polyurethane (serving as the elastic polymer) (sold by Formosa Asahi spandex, with a trade number of Roica) was dissolved in N,N-dimethyl acetamide, obtaining a first solution (with a solid content of 15 wt %). In addition, silver nanowires (serving as the conductive material) (having a diameter of 60 nm and a length of 22 μm) were dispersed in N,N-dimethyl acetamide, obtaining a second solution (with a solid content of 15 wt %). Next, the first solution was mixed with the second solution (the weight ratio of the first solution to the second solution was 1:1). Next, after stirring at 60° C. for 120 min (with a stirring rate of 200 rpm), silver nanowires were sufficiently dispersed in the mixture (including polyurethane). Next, a wet spinning process employing a device with two spinning nozzles was performed, wherein the mixture of first solution and the second solution served as the spinning solution of outer spinning nozzle, and water served as the spinning solution of the inner spinning nozzle, obtaining hollow Conductive elastic fiber (2). The spinning process was performed under the following conditions: the inner spinning nozzle had a diameter of 0.4 mm; the outer spinning nozzle had a diameter of 0.6 mm; the spinning temperature was about 60° C.; the inner spinning nozzle had a liquid flow speed of 0.6 cc/min; the outer spinning nozzle had a liquid flow speed of 1.2 cc/m in: the spinning speed of the spinning process was 5 m/min; water served as the coagulating bath; and the temperature of the coagulating bath was 40° C. Next, the fiber fineness of Conductive elastic fiber (2) was measured with a scanning electron microscope (JEOL JSM-6480), and the resistivity of Conductive elastic fiber (2) was measured using a resistance meter (RM3544, made by Hioki Co., Ltd.). The results are shown in Table 1.

EXAMPLE 3

Polyurethane (serving as the elastic polymer) (sold by Formosa Asahi spandex, with a trade number of Roica) was dissolved in N,N-dimethyl acetamide, obtaining a first solution (with a solid content of 15 wt %). In addition, silver nanowires (serving as the conductive material) (having a diameter of 60 nm and a length of 22 μm) and an adhesive (sold by Anfong with a trade number of U3251) were dispersed in N,N-dimethyl acetamide, obtaining a second solution (with a solid content of 15 wt %), wherein the weight ratio of the silver nanowire to the adhesive was 1:1. Next, a wet spinning process employing a device with two spinning nozzles was performed, wherein the first solution served as the spinning solution of the inner spinning nozzle and the second solution served as the spinning solution of the outer spinning nozzle, obtaining Conductive elastic fiber (3) with a core-shell structure (wherein the core portion consisted of the elastic polymer, and the shell portion consisted of the silver nanowire and the adhesive). The spinning process was performed under the following conditions: The inner spinning nozzle had a diameter of 0.4 mm; the outer spinning nozzle had a diameter of 0.6 mm; the spinning temperature was about 60° C.; the inner spinning nozzle had a liquid flow speed of 1.0 cc/min; the outer spinning nozzle had a liquid flow speed of 1.2 cc/min; the spinning speed of the spinning process was 5 m/min; water served as the coagulating bath; and, the temperature of the coagulating bath was 40° C. Next, the fiber fineness of Conductive elastic fiber (3) was measured with a scanning electron microscope (JEOL JSM-6480), and the resistivity of Conductive elastic fiber (3) was measured using a resistance meter (RM3544, made by Hioki Co., Ltd.). The results are shown in Table 1.

EXAMPLE 4

Polyurethane (serving as the elastic polymer) (sold by Formosa Asahi spandex, with a trade number of Roica) was dissolved in N,N-dimethyl acetamide, obtaining a first solution (with a solid content of 15 wt %). In addition, silver nanowires (serving as the conductive material) (having a diameter of 60 nm and a length of 22 μm) and an adhesive (sold by Anfong with a trade number of U3251) were dispersed in N,N-dimethyl acetamide, obtaining a second solution (with a solid content of 15 wt %), wherein the weight ratio of the silver nanowire to the adhesive was 4:3. Next, a wet spinning process employing a device with two spinning nozzles was performed, wherein the first solution served as the spinning solution of the inner spinning nozzle, and the second solution served as the spinning solution of the outer spinning nozzle, obtaining Conductive elastic fiber (4) with a core-shell structure (wherein the core portion consisted of the elastic polymer, and the shell portion consisted of the silver nanowire and the adhesive). The spinning process was performed under the following conditions: the inner spinning nozzle had a diameter of 0.4 mm; the outer spinning nozzle had a diameter of 0.6 mm; the spinning temperature was about 60° C.; the inner spinning nozzle had a liquid flow speed of 1.0 cc/m in; the outer spinning nozzle had a liquid flow speed of 1.2 cc/min; the spinning speed of the spinning process was 5 m/min; water served as the coagulating bath; and, the temperature of the coagulating bath was 40° C. Next, the fiber fineness of Conductive elastic fiber (4) was measured with a scanning electron microscope (JEOL JSM-6480) and the resistivity of Conductive elastic fiber (4) was measured using a resistance meter (RM3544, made by Hioki Co., Ltd.). The results are shown in Table 1.

EXAMPLE 5

Polyurethane (serving as the elastic polymer) (sold by Formosa Asahi spandex, with a trade number of Roica) was dissolved in N,N-dimethyl acetamide, obtaining a first solution (with a solid content of 15 wt %). In addition, silver nanowires (serving as the conductive material) (having a diameter of 60 nm and a length of 22 μm) and an adhesive (sold by Anfong with a trade number of U3251) were dispersed in N,N-dimethyl acetamide, obtaining a second solution (with a solid content of 15 wt %), wherein the weight ratio of the silver nanowire and the adhesive was 3:2. Next, a wet spinning process employing a device with two spinning nozzles was performed, wherein the first solution served as the spinning solution of inner spinning nozzle, and the second solution served as the spinning solution of outer spinning nozzle, obtaining a conductive elastic fiber with a core-shell structure (5) (wherein the core portion consisted of the elastic polymer, and the shell portion consisted of the silver nanowire and the adhesive). The spinning process was performed under the following conditions: the inner spinning nozzle had a diameter of 0.4 mm; the outer spinning nozzle had a diameter of 0.6 mm; the spinning temperature was about 60° C.; the inner spinning nozzle had a liquid flow speed of 1.0 cc/min; the outer spinning nozzle had a liquid flow speed of 1.2 cc/min; the spinning speed of the spinning process was 5 m/min; water served as the coagulating bath; and, the temperature of the coagulating bath was 40° C. Next, the fiber fineness of Conductive elastic fiber (5) was measured with a scanning electron microscope (JEOL JSM-6480), and the resistivity of Conductive elastic fiber (5) was measured using a resistance meter (RM3544, made by Hioki Co., Ltd.). The results are shown in Table 1.

EXAMPLE 6

Polyurethane (serving as the elastic polymer) (sold by Formosa Asahi spandex, with a trade number of Roica) was dissolved in N,N-dimethyl acetamide, obtaining a first solution (with a solid content of 15 wt %). In addition, silver nanowires (serving as the conductive material) (having a diameter of 60 nm and a length of 22 μm) and an adhesive (poly(styrene-butadiene-styrene), manufactured by JSR, with a trade number of TRD1002) were dispersed in N,N-dimethyl acetamide, obtaining a second solution (with a solid content of 15 wt %), wherein the weight ratio of the silver nanowire to the adhesive was 1:1. Next, a wet spinning process employing a device with two spinning nozzles was performed, wherein the first solution served as the spinning solution of inner spinning nozzle, and the second solution served as the spinning solution of outer spinning nozzle, obtaining Conductive elastic fiber (6) with a core-shell structure (wherein the core portion consisted of the elastic polymer, and the shell portion consisted of the silver nanowire and the adhesive). The spinning process was performed under the following conditions: the inner spinning nozzle had a diameter of 0.4 mm; the outer spinning nozzle had a diameter of 0.6 mm; the spinning temperature was about 60° C.; the inner spinning nozzle had a liquid flow speed of 1.0 cc/min; the outer spinning nozzle had a liquid flow speed of 1.2 cc/min; the spinning speed of the spinning process was 5 m/min; water served as the coagulating bath; and, the temperature of the coagulating bath was 40° C. Next, the fiber fineness of Conductive elastic fiber (6) was measured with a scanning electron microscope (JEOL JSM-6480), and the resistivity of Conductive elastic fiber (6) was measured using a resistance meter (RM3544, made by Hioki Co., Ltd.). The results are shown in Table 1.

COMPARATIVE EXAMPLE 1

Silver nanowires (serving as the conductive material) (having a diameter of 22 nm and a length of 22 μm) were dispersed in N,N-dimethyl acetamide, obtaining a first solution (with a solid content of 7.5 wt %). Next, polyurethane (serving as the elastic polymer) (sold by Formosa Asahi spandex, with a trade number of Roica) was added into the first solution during stirring at 60° C. with a stirring rate of 200 rpm. T weight ratio of polyurethane and the first solution was 7.5:100. After stirring for 12 hr, polyurethane was still not dissolved in the first solution, and a gel-like precipitate was observed, thereby inducing phase separation. Therefore, the result could not serve as a spinning solution for a spinning process.

	TABLE 1

	fiber fineness	resistivity

Conductive elastic fiber (1)	0.56 mm	14.4 Ω/cm
Conductive elastic fiber (2)	0.30 mm	55.0 Ω/cm
Conductive elastic fiber (3)	0.46 mm	4.68 Ω/cm
Conductive elastic fiber (4)	0.48 mm	1.10 Ω/cm
Conductive elastic fiber (5)	0.48 mm	0.90 Ω/cm
Conductive elastic fiber (6)	0.46 mm	33.0 Ω/cm

Accordingly, since the conductive material is uniformly dispersed in the elastic polymer or combined with the elastic polymer via an adhesive, the method for fabricating the conductive elastic fiber of the disclosure can prepare solid conductive elastic fibers, hollow conductive elastic fibers, or conductive elastic fibers with a core-shell structure.
It will be clear that various modifications and variations can be made to the disclosed methods and materials. It is intended that the specification and examples be considered as exemplary only, with the true scope of the disclosure being indicated by the following claims and their equivalents.

Claims

What is claimed is:

1. A method for fabricating the conductive elastic fiber, comprising:

providing a first solution, wherein the first solution comprises an elastic polymer dissolved in a first solvent, wherein the weight ratio of the elastic polymer to the first solvent is from 5:95 to 20:80;

providing a second solution, wherein the second solution comprises a conductive material dispersed in a second solvent, wherein the conductive material to the second solvent is from 5:95 to 20:80; and

subjecting the first solution and the second solution to a wet spinning process, obtaining the conductive elastic fiber.

2. The method as claimed in claim 1, wherein the elastic polymer is polyurethane, polyester, styrene-butadiene-styrene resin (SBS), nitrile butadiene rubber (NBR) or a combination thereof.

3. The method as claimed in claim 1, wherein the conductive material is conductive powder, rod-like conductive material, or conductive wire.

4. The method as claimed in claim 1, wherein the conductive material is a metal or an alloy of the metal, wherein the metal is gold, silver, copper, aluminum, or nickel.

5. The method as claimed in claim 1, wherein the conductive material is transparent conductive material.

6. The method as claimed in claim 1, wherein the first solution and the second solution is independently dimethylformamide, dimethylacetamide, dimethylsulfone, tetrahydrofuran, dichloromethane, chloroform, ethylene carbonate, propylene

7. The method as claimed in claim 1, wherein the second solution further comprising an adhesive, wherein the adhesive dissolved in the second solvent, wherein the weight ratio of the conductive material to the adhesive is from 1:2 to 50:1.

8. The method as claimed in claim 7, wherein the adhesive is a polymer or oligomer.

9. The method as claimed in claim 8, wherein the adhesive is polyurethane, styrene-butadiene-styrene resin (SBS), nitrile butadiene rubber (NBR) or a combination thereof.

10. The method as claimed in claim 1, wherein steps of subjecting the first solution and the second solution to a wet spinning process comprise:

mixing the first solution with the second solution, obtaining a third solution, wherein the first solvent is miscible with the second solvent, and the elastic polymer is dissolved in the second solvent; and

subjecting the third solution serving as a spinning solution to a wet spinning process.

11. The method as claimed in claim 10, wherein the weight ratio of the first solution and the second solution is from 1:2 to 3:1.

12. The method as claimed in claim 1, wherein steps of subjecting the first solution and the second solution to a wet spinning process comprise:

subjecting water serving as a spinning solution of inner spinning nozzle and the third solution serving as a spinning solution of outer spinning nozzle to a wet spinning process via a spinning device with two spinning nozzles.

13. The method as claimed in claim 12, wherein the weight ratio of the first solution and the second solution is from 1:2 to 3:1.

14. The method as claimed in claim 7, wherein steps of subjecting the first solution and the second solution to a wet spinning process, comprise:

subjecting the first solution serving as a spinning solution of the inner spinning nozzle and the second solution serving as a spinning solution of the outer spinning nozzle to a wet spinning process via a spinning device with two spinning nozzles.

15. A conductive elastic fiber, comprising:

an elastic polymer and a conductive material, wherein the weight ratio of the elastic polymer and the conductive material from 1:2 to 3:1.

16. The conductive elastic fiber as claimed in claim 15, wherein the conductive elastic fiber is a solid conductive elastic fiber.

17. The conductive elastic fiber as claimed in claim 15, wherein the conductive elastic fiber is a hollow conductive elastic fiber.

18. The conductive elastic fiber as claimed in claim 15, further comprising an adhesive, wherein the weight ratio of the conductive material to the adhesive is from 1:2 to 50:1.

19. The conductive elastic fiber as claimed in claim 18, wherein the conductive elastic fiber is a conductive elastic fiber with a core-shell structure, wherein the core-shell structure consists of a core portion and a shell portion, wherein the core portion comprises the elastic polymer, and the shell portion comprises the conductive material and the adhesive.

20. The conductive elastic fiber as claimed in claim 18, wherein the adhesive is a polymer or oligomer.