This application is the National Stage Application of PCT/CN2021/098235, filed on Jun. 4, 2021, which claims priority to Chinese Patent Application No. CN 202110603872.7, filed on May 31, 2021, which is incorporated by reference for all purposes as if fully set forth herein.
The invention relates to the technical field of fiber modification and preparation, and specifically to a silver-plated conductive nylon fiber and a preparation method thereof.
With the development of industry, the types and quantities of various household appliances and electronic devices are increasing, and people pay more and more attention to antistatic fibers. Therefore, the technologies for preparing conductive fibers are also constantly developing. One of the main technologies is preparing conductive fibers by chemical silver plating. Among numerous fibers, nylon fibers have a smooth surface and a complete structure and few active reactive groups. Therefore, how to improve the conductivity of nylon fibers has always been one of the main challenges for antistatic fibers.
Biomimetic mussel chemistry, represented by the oxidative self-polymerization of polyphenols, has attracted great attention in the material industry due to its high utilization rate, excellent effect and environment-friendliness, and has been widely used in surface and interface modification and functionalization of materials. The invention patent with an application number of CN 201811166015.x discloses a novel environment-friendly natural textile dye prepared by oxidative self-polymerization of tea polyphenols. The invention patent with an application number of CN 202011158029.4 discloses a tea polyphenol-rich skincare antibacterial tea fiber and a preparation method thereof. The invention patent with an application number of CN 202010492930.9 discloses a method for preparing a filtration membrane by modifying a nanofiber coating base with polydopamine.
The application of silver-plated conductive nylon fibers is very extensive. At present, the method of chemical silver plating is mainly used to metalize the surface of nylon fibers. The invention patent with an application number of CN 201011373886.3 discloses a method for preparing silver-plated conductive nylon fibers by sensitizing nylon fibers using stannous chloride. The invention patent with an application number of CN 201910343930.X discloses an anti-oxidation silver-plated nylon fiber with a protective film. The invention patent with an application number of CN 201410148781.9 discloses a method for preparing a silver-plated electromagnetic shielding lining cloth from silver-plated nylon.
The common disadvantage of the current chemical silver plating processes is that stannous chloride used as the sensitizer in the chemical silver plating process is highly toxic, and it is easy to cause respiratory infections and skin diseases in the production and processing process. Therefore, it has extremely high requirements on production workshops, production equipment and worker protection. In addition, the surface of nylon is smooth with few reactive groups, and is often pretreated with a strong oxidant, resulting in a significant decrease in the strength of nylon fibers. If the surface of nylon is not pretreated with a strong oxidant, the silver coating is not firmly bonded to the nylon fiber and easily falls off. Therefore, developing a method for preparing conductive nylon fibers in an environment-friendly manner while maintaining the strength of nylon fibers and ensuring firm bonding between the silver coating and the nylon fibers without using a heavy metal sensitizer and pretreatment with a strong oxidant is critical for the development of antistatic, electromagnetic shielding, composite material, and other fields.
An object of the invention is to provide a silver-plated conductive nylon fiber and a preparation method thereof. This method does not use a heavy metal sensitizer and does not need pretreatment with a strong oxidant, so that the strength of nylon fibers is maintained, and the silver coating is firmly bonded to the nylon fibers.
The object of the invention is accomplished through the following technical solutions:
The invention provides a method for preparing a silver-plated conductive nylon fiber, including the following steps:
Preferably, before the step (1), the method further includes step (la): soaking the nylon fiber in sulfuric acid with a concentration of 20 mL/L to 100 mL/L at 40° C. to 60° C. for 20 to 120 min, followed by washing and dehydration. This step can coarsen the fiber surface and provide more reaction sites.
Preferably, the chemical silver plating includes: soaking the surface-activated nylon fiber obtained in the step (2) in a silver ammonia solution added with a reducing agent at 30° C. to 50° C. for reaction for 20 to 90 min. The treated fiber surface is covered with a layer of dense elemental silver by the silver mirror reaction under weak alkaline conditions.
Preferably, the reducing agent is selected from the group consisting of glucose, acetaldehyde, formaldehyde and any combination thereof.
Preferably, the silver ammonia solution is further added with a surfactant.
Preferably, the surfactant includes polyvinylpyrrolidone and/or sodium dodecylbenzenesulfonate. Preferably, the molecular weight of polyvinylpyrrolidone is 500,000 to 1,300,000. The surfactant can adjust the deposition rate, improve the gloss of the coating, and improve the surface evenness and smoothness of the coating.
Preferably, the surfactant has a concentration of 5 g/L to 15 g/L.
Preferably, in the step (1), the polyphenolic compound is selected from the group consisting of eugenol, tannic acid, ferulic acid, chlorogenic acid and any combination thereof; the water-soluble oxidant is selected from the group consisting of sodium perborate, sodium persulfate, potassium perborate and any combination thereof; and in the reaction solution, the water-soluble oxidant has a concentration of 1 g/L to 3 g/L. After the polyphenolic compound is polymerized, a polymerized polyphenolic layer can be formed, which has high adhesion and can serve as a secondary reaction platform.
Preferably, after the step (3), the method further includes a step (4): washing and dehydrating the silver-plated conductive nylon fiber, and drying at 90° C. to 140° C. for 2 to 10 min.
In the invention, the biomimetic mussel chemistry represented by the oxidative self-polymerization of polyphenols replaces the sensitizer stannous chloride in the conventional processes with natural polyphenols, which is environment-friendly and ensures that the fiber strength is hardly affected. The polymerized polyphenol has strong adhesion, can be deposited on various materials as a secondary reaction platform, and can also well ensure the fastness after silver plating. Compared with the conventional methods for preparing silver-plated conductive fibers, the invention provides a new idea for preparing a novel silver-plated conductive nylon fiber.
Another object of the invention is to provide a silver-plated conductive nylon fiber, which is prepared by any of the above preparation method.
Preferably, the silver-plated conductive nylon fiber of the invention includes a nylon fiber body, where a polymerized polyphenolic layer and a conductive layer are provided on the surface of the nylon fiber body in sequence from the inside to the outside, and the conductive layer includes a plurality of silver nanoparticles.
Preferably, the thickness of the conductive layer is 50 nm to 400 nm.
Preferably, the thickness of the polymerized polyphenolic layer is 1.5 nm to 2.2 μm.
The principle underlying the preparation method provided in the invention is as follows.
First, the surface of the fiber is optionally coarsened with sulfuric acid, which can degrade part of the polyamide and expose more reactive sites such as carboxyl and amino groups on the surface of the nylon fiber. Then polyphenols are easily oxidized and self-polymerized in the presence of an oxidant under alkaline conditions, where the catechol group is induced to be oxidized to quinone, which undergoes Michael addition and Schiff reaction with the amino groups on the surface of the nylon fiber (see
By means of the above solution, the invention has the following advantages.
The method for preparing a silver-plated conductive nylon fiber provided by the invention can achieve the sensitization effect without using a heavy metal sensitizer, such as stannous chloride. The preparation process is non-toxic and environment-friendly. The preparation method does not require pretreatment of the nylon fiber with a strong oxidant, so that the strength of the nylon fiber is maintained, and a strong bonding force can be achieved between the silver coating and the nylon fiber. The polymerized polyphenol on the fiber surface has strong adhesion and can be used as a reaction platform for silver plating to improve the fastness of silver plated and prolong the service life. The preparation method is of low energy consumption, short reaction period, simple operation, and high energy utilization rate, and can expand the use value of nylon fibers and increase the additional value of products.
The silver-plated conductive nylon fiber provided by the invention has the advantages of high fiber strength and firm bonding of the coating which does not easily fall off. In addition, the polymerized polyphenol has good biocompatibility, and naturally has antibacterial, anti-mite and other properties. Therefore, the prepared conductive nylon fiber integrates multiple functions.
The above description is only a summary of the technical solutions of the invention. To make the technical means of the invention clearer and implementable in accordance with the disclosure of the specification, the preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
The specific embodiments of the invention will be described in further detail with reference to tables and examples. The following examples are intended to illustrate the invention, instead of limiting the scope of the invention.
The surface of the nylon 56 fiber treated with eugenol was covered with dense silver elemental grains, and the fiber surface was rough, had certain fastness and strength, and had good electrical conductivity.
The surface of the nylon 56 fiber treated with chlorogenic acid was covered with dense silver elemental grains, and the fiber surface was rough, had certain fastness and strength, and had good electrical conductivity.
The surface of the nylon 66 fiber treated with ferulic acid was covered with dense silver elemental grains, and the fiber surface was rough, had certain fastness and strength, and had good electrical conductivity.
The surface of the nylon 6 fiber treated with eugenol was covered with dense silver elemental grains, and the fiber surface was rough, had certain fastness and strength, and had good electrical conductivity.
A fiber mechanical test (according to GB/T 14337-2008), electrical performance test (according to FZ/T 52032-2014), and fastness to soaping test (according to GB/T 14337-2008) were carried out on the conductive fibers prepared in the above examples. The results are shown in Tables 1 to 3.
To sum up, it can be clearly seen that in the embodiments provided by the invention, a polymerized polyphenol layer and a conductive layer are formed on the surface of nylon fiber without using a heavy metal sensitizer, to obtain a conductive nylon fiber. The preparation process is safe and environment-friendly. The conductive nylon fiber obtained by the method has excellent electrical conductivity and the strength of the nylon fiber is basically not damaged. The conductive layer is firmly bonded and does not easily fall off.
While preferred embodiments of the invention have been described above, the invention is not limited thereto. It should be appreciated that some improvements and variations can be made by those skilled in the art without departing from the technical principles of the invention, which are also contemplated to be within the scope of the invention.
Number | Date | Country | Kind |
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202110603872.7 | May 2021 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2021/098235 | 6/4/2021 | WO |
Publishing Document | Publishing Date | Country | Kind |
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WO2022/252199 | 12/8/2022 | WO | A |
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3003975 | Louis | Oct 1961 | A |
4362779 | Arsac | Dec 1982 | A |
20210032755 | Philibert | Feb 2021 | A1 |
Number | Date | Country |
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106917075 | Jul 2017 | CN |
109161876 | Jan 2019 | CN |
111005215 | Apr 2020 | CN |
Number | Date | Country | |
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20240026601 A1 | Jan 2024 | US |