Conductive monofilament and method of making same

Abstract

The application discloses a conductive monofilament and a preparation method thereof. The conductive monofilament comprises an inner layer and an outer layer, the outer layer wraps the inner layer, the inner layer is a nylon monofilament, and the outer layer is a conductive coating. The conductive coating comprises the following components by weight: 50-55 parts of DMSO; 16-20 parts of polyurethane resin; 18-20 parts of conductive mica powder; 7-9 parts of conductive graphene; and 3-4 parts of superfine silicon dioxide powder. According to the technical scheme provided by the embodiment of the application, the inner and outer layer structure formed by wrapping the inner layer monofilament with the conductive coating slurry has the effect of conducting electricity, and the conductive coating is arranged by using materials such as conductive mica powder and conductive graphene, so that the formed conductive coating is light in color, the formed conductive monofilament is also light in color, the prepared conductive monofilament has high strength and good conductivity, and the light-colored conductive monofilament can have more application scenarios.

Description

Conductive monofilaments and their preparation methods Technical Field

[0001] This invention generally relates to the field of monofilament technology, and more particularly to conductive monofilaments and their preparation methods. Background Technology

[0002] Polyamide, commonly known as nylon, is an insulating material and does not possess conductive properties. However, with continuous technological advancements, functional fibers play a crucial role in national production sectors such as textiles, medicine, and communications, among which the research of conductive fibers is receiving increasing attention. Conductive fibers, based on their conductivity, can be widely used in fields such as antistatic applications, electromagnetic shielding, electrothermal functions, and electronic communications. To achieve conductivity in nylon monofilaments, two methods are generally used: one is to add conductive fillers, and the other is to composite them with conductive polymers.

[0003] Adding conductive fillers is currently the main method for making nylon monofilaments conductive. Commonly used conductive fillers include carbon black, metal powder, and metal fibers, which can transform the insulating properties of nylon into conductive properties. However, because carbon black is used as a conductive filler, the resulting conductive monofilaments are generally black, and the demand for other colors or light-colored conductive monofilaments has not been met, which also limits the application areas of conductive monofilaments. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a conductive monofilament and a method for its preparation.

[0005] In a first aspect, a conductive monofilament is provided, the conductive monofilament comprising an inner layer and an outer layer, the outer layer wrapping the inner layer, the inner layer being a nylon monofilament, and the outer layer being a conductive coating, the conductive coating being composed of:

[0006]

[0007]

[0008] The total weight of the DMSO, the polyurethane resin, the conductive mica powder, the conductive graphene, and the ultrafine silica is 100.

[0009] As an alternative method, the surface of the nylon monofilament is surface-treated using a plasma machine.

[0010] As an feasible approach, the conductive monofilament is light-colored, preferably pale yellow.

[0011] As an example, the conductive mica powder has a particle size of 40-50 micrometers.

[0012] As an example, the conductive graphene has a particle size of 20-30 nm.

[0013] As an example, the ultrafine silica powder has a particle size of 9-12 micrometers.

[0014] As an example, the conductive coating is deposited on the surface of the nylon monofilament by ultrasonic chemical deposition.

[0015] Secondly, a method for preparing a conductive monofilament is provided, comprising the following steps:

[0016] Preparation of slurry: Mix DMSO, polyurethane resin, conductive mica powder, conductive graphene, and ultrafine silica in a mass ratio of (50-55):(16-20):(18-20):(7-9):(3-4), and disperse the mixed material in a disperser for 2-4 hours.

[0017] Inner layer monofilament preparation: Nylon monofilament is provided, and the nylon monofilament is placed in a plasma machine to perform surface treatment on the nylon monofilament by oxygen or air;

[0018] Preparation of conductive monofilament: The slurry is placed in an ultrasonic coating tank, and the surface-treated nylon monofilament passes through the ultrasonic coating tank at a set speed. After passing through, the conductive monofilament is dried and wound up.

[0019] According to the technical solution provided in the embodiments of this application, the inner and outer layer structure formed by wrapping the inner layer monofilament with conductive coating slurry has a conductive effect. Furthermore, by setting the conductive coating with materials such as conductive mica powder and conductive graphene, the conductive coating is light in color, and the conductive monofilament is also light in color. The prepared conductive monofilament has high strength and good conductivity, and the light-colored conductive monofilament can be used in more application scenarios. Attached Figure Description

[0020] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0021] Figure 1 is a flowchart of the preparation of the conductive monofilament in this embodiment;

[0022] Figure 2 is a schematic diagram of the equipment used for the conductive monofilament coating process in this embodiment.

[0023] Figure label:

[0024] 1-Ultrasonic coating tank; 2-Nylon monofilament; 3-Drying device;

[0025] 4- Winding device. Detailed Implementation

[0026] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] This embodiment provides a conductive monofilament, which includes an inner layer and an outer layer. The outer layer wraps around the inner layer. The inner layer is a nylon monofilament, and the outer layer is a conductive coating. The composition of the conductive coating is as follows:

[0029]

[0030] The total weight of the DMSO, the polyurethane resin, the conductive mica powder, the conductive graphene, and the ultrafine silica is 100.

[0031] The conductive monofilament provided in this embodiment is configured as an inner and outer layer. The inner layer is a nylon monofilament, which meets the requirement of high strength. In addition, the inner and outer layer structure formed by coating the inner monofilament with a conductive coating paste has a conductive effect. Furthermore, the conductive coating is made of materials such as conductive mica powder and conductive graphene, resulting in a light-colored conductive coating and a light-colored conductive monofilament. The prepared conductive monofilament has both high strength and good conductivity, and the light-colored conductive monofilament can be used in more application scenarios.

[0032] In this embodiment, conductive mica powder and conductive graphene are used as conductive materials. The conductive mica powder is a bright white, while the conductive graphene is transparent. Combined with other materials, the resulting conductive coating slurry ranges from white to pale yellow. When coated onto nylon monofilaments, it forms pale yellow conductive monofilaments. Because of the color of the conductive mica powder itself, it does not reveal the color of the nylon monofilaments, ensuring that the resulting conductive monofilaments are pale yellow. This allows for wider applications, such as wearable devices. Furthermore, other color dyes can be added to create a wider range of colors according to user needs.

[0033] The inner nylon monofilament is prepared by melt spinning from one or more of polycaprolactam (PA6), polyhexamethylene adipamide (PA66), and caprolactam-hexamethylene adipamide copolymer.

[0034] The original diameter of the nylon monofilament is 0.08-1 mm, and the monofilament strength is 3-5.9 cN / dtex. This results in a nylon monofilament core with high strength, ensuring that the manufactured supporting monofilament has both the conductivity of the outer layer structure and high monofilament strength. Furthermore, the nylon material can be a single material or a mixture of multiple materials without affecting its strength.

[0035] Optionally, the surface of the nylon monofilament is subjected to surface treatment using a plasma machine.

[0036] In this embodiment, the nylon monofilaments are all surface-treated by a plasma machine. Preferably, the surface of the nylon monofilaments is treated with oxygen or air to improve the adhesion of the nylon monofilaments, so that the conductive paste formed can be uniformly and firmly attached to the surface of the nylon monofilaments, thereby forming conductive monofilaments with good conductivity.

[0037] Optionally, the conductive monofilament is light-colored, preferably pale yellow. In this embodiment, conductive mica powder and conductive graphene are used as components of the conductive outer layer, while other components are transparent. Therefore, the resulting outer conductive coating is pale yellow, and the overall color remains pale yellow after encasing the inner nylon monofilament. Its light color allows for applications in fields such as wearable devices. Furthermore, the color can be changed by varying the amount of conductive mica powder and other components added, resulting in a light-colored conductive monofilament, such as white.

[0038] Optionally, the conductive mica powder has a particle size of 40-50 micrometers. The conductive mica powder used in this embodiment has a smaller particle size, which allows for better formation of the conductive coating slurry.

[0039] Optionally, the conductive graphene has a particle size of 20-30 nm. In this embodiment, both the conductive mica powder and the conductive graphene are used as conductive materials for the conductive coating, and their particle sizes are both set to be relatively small. When uniformly mixed, they can form a conductive coating with better conductivity.

[0040] Optionally, the particle size of the ultrafine silica powder is 9-12 micrometers. In this embodiment, DMSO is used as the organic solvent, and polyamide resin is used to prepare the slurry. The prepared conductive coating slurry can be better coated on the surface of nylon monofilaments and is less prone to peeling. The ultrafine silica powder, as a thixotropic agent, mixed with conductive mica powder, can be evenly distributed in the slurry to prevent sedimentation. The conductive coating formed after the conductive slurry is coated on the surface of nylon monofilaments has good conductivity.

[0041] Furthermore, the conductive coating is deposited on the surface of the nylon monofilament by ultrasonic chemical deposition.

[0042] In this embodiment, the conductive coating slurry is coated onto the surface of the nylon monofilament using a chemical deposition method. Preferably, the structure shown in Figure 2 is adopted. The nylon monofilament 2 is first stretched and tensioned by multiple rollers at the front, so that the monofilament 2 between the rear winding device 4 and the rollers is kept taut, resulting in better winding and coating effects. The nylon monofilament passes through the ultrasonic coating tank 1, which is equipped with tensioning rollers located inside the slurry, ensuring that the monofilament is surrounded by the slurry for the conductive coating. Subsequently, the coated monofilament passes through the rear drying device 3 and is wound by the winding device. The winding speed of the winding device 4 corresponds to the time the nylon monofilament spends in the ultrasonic coating tank 1 and is related to the thickness and other properties of the conductive coating to be coated.

[0043] The conductive monofilament formed in this embodiment uses nylon monofilament as the inner core, exhibiting good overall strength. Simultaneously, the coated conductive paste can form a monochromatic conductive monofilament with excellent conductivity. The resulting conductive monofilament has a breaking strength of at least 6.4 cN / dtex and a resistivity of at least 10⁻⁶. 7 Ω / cm.

[0044] This embodiment provides a method for preparing a conductive monofilament, including the following steps:

[0045] Preparation of slurry: Mix DMSO, polyurethane resin, conductive mica powder, conductive graphene, and ultrafine silica in a mass ratio of (50-55):(16-20):(18-20):(7-9):(3-4), and disperse the mixed material in a disperser for 2-4 hours.

[0046] Inner layer monofilament preparation: Nylon monofilament is provided, and the nylon monofilament is placed in a plasma machine to perform surface treatment on the nylon monofilament by oxygen or air;

[0047] Preparation of conductive monofilament: The slurry is placed in an ultrasonic coating tank, and the surface-treated nylon monofilament passes through the ultrasonic coating tank at a set speed. After passing through, the conductive monofilament is dried and wound up.

[0048] The method provided in this embodiment first mixes the above components according to a certain mass ratio and disperses them in a disperser so that the components can be mixed evenly. The conductive mica powder and conductive graphene in the slurry can be evenly distributed, and the conductive coating formed has good conductivity everywhere.

[0049] The conductive paste is then placed in an ultrasonic coating tank, with the paste exceeding the rollers inside the tank to ensure that the nylon monofilament is completely coated with the paste and that the conductive paste can evenly cover the nylon monofilament. Finally, a winding device is used to wind the nylon monofilament. The winding speed of the winding device is preferably set to 20-40 r / min, while the drying device at the front end of the winding device dries the conductive monofilament in a timely manner.

[0050] The following are three specific implementation examples:

[0051] Example 1:

[0052] Step 1: Preparation of the slurry

[0053] 55 parts of DMSO, 18 parts of polyurethane resin, 18 parts of conductive mica powder, 9 parts of conductive graphene, and 4 parts of ultrafine SiO2 powder were dispersed in a disperser for 3 hours.

[0054] Step 2: Coating

[0055] First, the surface of the nylon monofilament is treated with plasma gas. The slurry is placed in the ultrasonic coating tank of the coating equipment to coat the monofilament. The control panel parameters are set, the drawing machine speed is 20.2 r / min, the coating is dried in an oven at 130℃, and finally the yarn is taken up by the yarn take-up device.

[0056] The conductor has a breaking strength of 6.1 cN / dtex and a resistivity of 10. 3 Ω / cm.

[0057] Example 2:

[0058] Step 1: Preparation of the slurry

[0059] 55 parts of DMSO, 18 parts of polyurethane resin, 20 parts of conductive mica, 7 parts of conductive graphene, and 4 parts of ultrafine SiO2 powder were dispersed in a disperser for 4 hours.

[0060] Step 2: Coating

[0061] First, the surface of the nylon monofilament is treated with plasma gas. Then, the slurry is placed in the ultrasonic coating tank of the coating equipment and coated onto the monofilament. The control panel parameters are set: the drawing machine speed is 30.5 r / min, the post-coating oven temperature is 130℃, and finally, the nylon monofilament is taken up by the take-up device.

[0062] The conductor has a breaking strength of 6.3 cN / dtex and a resistivity of 10. 3 Ω / cm.

[0063] Example 3

[0064] Step 1: Preparation of the slurry

[0065] 55 parts of DMSO, 18 parts of polyurethane resin, 19 parts of conductive mica, 8 parts of conductive graphene, and 3 parts of ultrafine SiO2 were dispersed in a disperser for 2 hours.

[0066] Step 2: Coating

[0067] First, the surface of the nylon monofilament is treated with plasma gas. Then, the slurry is placed in the ultrasonic coating tank of the coating equipment to coat the monofilament. The control panel parameters are set: the drawing machine speed is 35 r / min, the post-coating oven temperature is 130℃, and finally, the nylon monofilament is taken up by the take-up device.

[0068] The conductor has a breaking strength of 6.3 cN / dtex and a resistivity of 10. 3 Ω / cm.

[0069] The embodiments given above illustrate that the monofilaments provided in this application possess both high strength and good electrical conductivity. Furthermore, the conductive monofilaments provided in this embodiment are all light-colored monofilaments.

[0070] It should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used above to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention; the directional terms "inner" and "outer" refer to the inside or outside relative to the outline of each component itself. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0071] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, rotated 90 degrees, or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0072] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A conductive monofilament, characterized in that, The conductive monofilament comprises an inner layer and an outer layer, the outer layer wrapping the inner layer. The inner layer is a nylon monofilament, and the outer layer is a conductive coating. The conductive coating is composed of: 50-55 parts by weight of DMSO; 16-20 parts by weight of polyurethane resin; 18-20 parts by weight of conductive mica powder; 7-9 parts by weight of conductive graphene; and 3-4 parts by weight of ultrafine silica powder. The total weight of the DMSO, polyurethane resin, conductive mica powder, conductive graphene, and ultrafine silica is 100.

2. The conductive monofilament according to claim 1, characterized in that, The surface of the nylon monofilament is treated with a plasma machine.

3. The conductive monofilament according to claim 1, characterized in that, The conductive monofilament is light-colored.

4. The conductive monofilament according to claim 1, characterized in that, The conductive mica powder has a particle size of 40-50 micrometers.

5. The conductive monofilament according to claim 1, characterized in that, The conductive graphene has a particle size of 20-30 nm.

6. The conductive monofilament according to claim 1, characterized in that, The particle size of the ultrafine silica powder is 9-12 micrometers.

7. The conductive monofilament according to claim 1, characterized in that, The conductive coating is deposited on the surface of the nylon monofilament by ultrasonic chemical deposition.

8. A method for preparing a conductive monofilament according to any one of claims 1-7, characterized in that, The process includes the following steps: Slurry preparation: DMSO, polyurethane resin, conductive mica powder, conductive graphene, and ultrafine silica are mixed in a mass ratio of (50-55):(16-20):(18-20):(7-9):(3-4), and the mixed material is dispersed in a disperser for 2-4 hours; Inner layer monofilament preparation: Nylon monofilaments are provided and placed in a plasma machine for surface treatment with oxygen or air; Conductive monofilament preparation: The slurry is placed in an ultrasonic coating tank, and the surface-treated nylon monofilaments pass through the ultrasonic coating tank at a set speed. The conductive monofilaments are then dried and wound up.

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