WO2023097480A1

WO2023097480A1 - Conductive fabric based on metal organic decomposition ink, preparation method therefor, and application thereof

Info

Publication number: WO2023097480A1
Application number: PCT/CN2021/134510
Authority: WO
Inventors: 万艳君; 廖思远; 王晓允; 朱朋莉; 孙蓉
Original assignee: 中国科学院深圳先进技术研究院
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2023-06-08

Abstract

Disclosed are a conductive fabric based on a metal organic decomposition ink, a preparation method therefor and an application thereof. According to the method, a fabric substrate is immersed in the metal organic decomposition ink and annealed to prepare the conductive fabric. The metal organic decomposition ink used comprises a metal salt precursor (copper salt, silver salt, aluminum salt and nickel salt), an organic amine complexing agent and an alcohol organic solvent carrier, and has a decomposition temperature of 150 to 200°C. According to the method, after the fabric substrate is fully immersed in the metal organic decomposition ink, metal ions in the ink permeating into the fabric substrate are reduced into metal particles through annealing, and a metal layer is formed through deposition to prepare the conductive fabric. According to the invention, the wettability of the metal organic decomposition ink in the fabric substrate is high, so that the metal ions in the ink can enter the fabric substrate more easily. The prepared conductive fabric not only has excellent electromagnetic shielding performance, but also maintains the mechanical property of the original fabric substrate.

Description

A kind of conductive fabric based on metal organic decomposition ink, preparation method and application thereof

technical field

The invention relates to the technical field of functional materials, in particular to a conductive fabric based on metal organic decomposition ink, a preparation method and an application thereof.

Background technique

With the rapid development of 5G communication technology, electromagnetic interference is becoming more and more serious, which will not only interfere with the normal operation of devices, but even endanger human health. Therefore, shielding materials that can be applied to electronic equipment in aerospace, 5G systems and other fields have emerged as the times require. As a kind of electromagnetic shielding material, conductive fabric has taken into account the requirements of flexibility and portability, and has been widely used in many fields. According to their increased conductive components, conductive fabrics can be classified into three categories: polymer-based conductive fabrics, metal-based conductive fabrics, and carbon-based conductive fabrics.

In the prior art, the preparation of polymer-based conductive fabrics is mainly through the blending or weaving of conductive fibers and fabric fibers in the early stage to form conductive fabrics. It is also possible to form conductive layers (such as metal layers, conductive polymers, etc.) by chemically modifying the surface of the fabrics. Even surface carbonization, etc.) to prepare conductive fabrics.

In the preparation method of the conductive layer, the electroless plating method is a kind of situation where no current passes, through a controllable redox reaction, using a strong reducing agent in a solution containing metal ions, the metal ions are reduced to metal and deposited on the fabric. A conductive layer is formed on the surface. The process flow is: mechanical roughening→chemical degreasing→water washing→chemical roughening→water washing→sensitization→water washing→activation→water washing→degumming→water washing→electroless plating→water washing→drying→plating post-treatment. In the process of electroless plating, it is generally necessary to pre-plate a catalyst seed layer on the surface of the fabric, and then reduce the metal layer by oxidation-reduction methods, but the catalyst palladium used is a heavy metal, which has high cost and large pollution of the plating solution. Shortcomings.

In order to improve the controllability of the surface coating of conductive fabrics, an electroplating method has been developed, which uses negative and positive electrodes to promote the oxidation-reduction reaction of metal compounds, thereby reducing the intervention of oxidizing agents and reducing agents. It uses fabric material as an electrode, and directly deposits conductive material on the surface of the fabric electrode. Because the fabric itself is an insulator, it cannot be directly used as an electrode. Therefore, it is often necessary to endow the fabric with a certain degree of conductivity or directly select commercial conductive yarns before performing the electroplating reaction. On this basis, the conductive layer is deposited by electrochemical method, the conductive fabric is coated on the metal electrode as the working electrode, and sufficient positive bias is applied to trigger a reaction on the working electrode, so that the metal cations are passively deposited on the fabric. . The electroplating method currently uses cyanide electroplating, which is highly toxic and potentially harmful to the human body and the environment. At the same time, the wastewater and waste gas generated by electroplating will also cause environmental pollution.

Therefore, no matter the electroplating method or the electroless plating method, there are problems such as too complicated process flow, high cost, serious chemical pollution, etc., and it is difficult to mass-produce and meet the requirements of environmental protection. Therefore, it is necessary to develop a simple, environmentally friendly, and low-cost preparation method.

Contents of the invention

Based on the above background technology, the present invention provides a conductive fabric based on metal organic decomposition ink, a preparation method and its application.

In order to achieve the above object, the technical scheme that the present invention takes is:

The first aspect of the present invention provides a metal-organic decomposition ink, the metal-organic decomposition ink includes a metal salt precursor, a complexing agent and an organic solvent carrier;

The metal salt precursor is selected from any one of copper salt precursor, silver salt precursor, aluminum salt precursor and nickel salt precursor;

The complexing agent is selected from any one or several of organic amines;

The organic solvent carrier is selected from any one or several alcohols;

The decomposition temperature of the metal organic decomposition ink is 150-200°C.

In some specific embodiments, the decomposition temperature of the metal organic decomposition ink is 150°C, 160°C, 170°C, 180°C, 190°C, 200°C or any temperature between them.

As a preferred embodiment, the copper salt precursor is selected from any one of copper acetate, copper formate, copper glycolate, copper chloride, copper oleate and copper hydroxide;

As a preferred embodiment, the silver salt precursor is selected from any one of silver decanoate, silver oxide, silver carbonate, silver tartrate, hexafluoroacetylacetone-cyclooctadiene silver, silver sulfate and silver nitrate;

As a preferred embodiment, the aluminum salt precursor is selected from any one of aluminum trichloride and aluminum sulfate;

As a preferred embodiment, the nickel salt precursor is selected from any one of nickel acetate, nickel sulfate, nickel halide, nickel sulfamate, nickel bromide and nickel hydroxide;

Preferably, the organic amine is selected from methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, ethylenediamine, ammonium hydroxide, triethanolamine, ethanolamine, N,N-dimethylformamide and iso Any one or more of propionate;

Preferably, the alcohols are selected from the group consisting of methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, glycol ether, glycerin, diethylene glycol, triethylene glycol, β-terpineol, γ-terpene Any one or several of pinol and delta-terpineol.

As a preferred embodiment, in the organometallic decomposition ink, the molar ratio of the metal ion in the metal salt precursor to the complexing agent is ≤1:2; for example, 0.1, 0.2, 0.3, 0.4, 0.5 or one of them Any molar ratio between.

Preferably, the molar ratio of the metal salt in the metal salt precursor to the organic solvent carrier is 1:1-10, such as 1:1, 1:2, 1:3, 1:4, 1:5, 1 :6, 1:7, 1:8, 1:9, 1:10 or any molar ratio between them.

The second aspect of the present invention provides the preparation method of the metal organic decomposition ink, comprising the following steps:

After mixing the complexing agent and the metal salt precursor, stirring once, adding an organic solvent carrier after cooling, and stirring again.

As a preferred embodiment, the rotational speed of the primary stirring is 100-1000 rpm, and the stirring time is 10-60 minutes;

Preferably, the rotation speed of the secondary stirring is 100-1000 rpm, and the stirring time is 10-60 minutes.

In some specific embodiments, the rotation speed of the primary stirring is 100 rpm, 200 rpm, 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm , 800 rpm, 900 rpm, 1000 rpm or any rotation speed between them; the stirring time is 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes or any stirring between them time.

In some specific embodiments, the rotation speed of the secondary stirring is 100 rpm, 200 rpm, 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm minute, 800 rpm, 900 rpm, 1000 rpm or any rotation speed between them; stirring time is 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes or any of them Stiring time.

As a preferred embodiment, the preparation method of the above-mentioned metal organic decomposition ink also includes an impurity removal operation;

Preferably, the impurity removal operation is centrifugal filtration or syringe filtration.

The third aspect of the present invention provides a method for preparing a conductive fabric based on metal-organic decomposition ink, which includes the following steps: soaking the fabric substrate in the above-mentioned metal-organic decomposition ink, and then annealing to obtain a conductive fabric.

In the technical solution of the present invention, after the metal organic decomposition ink is fully infiltrated with the fabric substrate, since the metal in the ink is in an ion state, it can fully infiltrate with the fabric substrate and penetrate into the interior of the fabric substrate. During the slow annealing reduction process, The metal particles are reduced, and finally the metal particles will deposit a layer of metal on the surface of the fabric, realizing one-step reduction to prepare conductive fabrics.

As a preferred embodiment, the soaking time is 10min to 24h;

Preferably, the temperature of the annealing is 150-200° C., and the time is 10-60 minutes;

Preferably, the annealing is vacuum annealing.

In some specific embodiments, the soaking time is 10min, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 15h, 20h, 21h, 24 or their any time between

In some specific embodiments, the annealing temperature is 150°C, 160°C, 170°C, 180°C, 190°C, 200°C or any temperature between them, and the time is 10min, 20min, 30min, 40min , 50min, 60min or any time in between.

In the technical solution of the present invention, the thickness of the metal layer deposited by the metal particles is related to the soaking time before annealing, and the thickness of the deposited metal layer can be changed by changing the soaking time, thereby affecting the conductivity and shielding performance of the conductive fabric.

In the technical solution of the present invention, during the annealing process, the metal ions are gradually reduced to form a conductive network, but after the annealing reaches a certain level, the shielding effectiveness of the conductive fabric will reach the upper limit, and continuing to prolong the annealing time will not only not improve the shielding effect of the conductive fabric. Effectiveness, on the contrary, will reduce the mechanical properties of the material, so it is necessary to control the annealing time.

In some specific embodiments, the fabric base includes but is not limited to non-woven fabrics, cellulose, cotton cloth and filter paper, polyamide fibers, polyurethane fibers, polyester fibers, polyacrylonitrile, polyvinyl acetal fiber, polyvinyl chloride fiber, polypropylene fiber, polyethylene fiber or aramid fiber, etc.

The fourth aspect of the present invention provides the conductive fabric based on metal organic decomposition ink obtained by the above preparation method.

The fifth aspect of the present invention provides the use of the above-mentioned conductive fabric based on metal organic decomposition ink as an electromagnetic shielding material.

The above technical solution has the following advantages or beneficial effects:

The invention provides a conductive fabric based on a metal organic decomposition ink and a preparation method thereof. After the metal organic decomposition ink is fully infiltrated with the fabric base, the metal ions in the ink infiltrated into the fabric base are reduced to metal particles through an annealing process. A metal layer is deposited to prepare a conductive fabric. The present invention selects organic amine as the organic solvent carrier of the ink, and the functional groups contained in it have interaction with the polar functional groups (hydroxyl and carboxyl) of the fabric substrate, so the metal organic decomposition ink and the fabric substrate can be easily blended and infiltrated, making the ink in the ink The metal ions in the fabric are more likely to enter the interior of the fabric substrate, and are used for metallization of the fabric surface through in-situ sintering to form a conductive network.

The present invention has the following advantages:

1. The metal-organic decomposition ink provided by the present invention has a decomposition temperature of ≤200°C. While improving the electromagnetic shielding effectiveness of conductive fabrics, it will not affect the mechanical properties of the fabrics. The optimum electromagnetic shielding effectiveness and mechanical properties can be achieved by controlling the preparation process. Excellent solution;

3. The conductive fabric provided by the present invention has excellent electromagnetic shielding efficiency and mechanical properties, its electrical conductivity can reach up to 1.35×10 ² S/cm, its shielding efficiency can reach up to 63dB, its tensile strength can reach up to 43MPa, and its breaking elongation The elongation rate can reach up to 17%;

2. Compared with the traditional electroless plating method, the metal organic decomposition ink provided by the present invention does not need to introduce palladium and other catalysts, but uses complexing agent, metal salt precursor and organic solvent carrier to realize one-step reduction in the annealing process to prepare the metal layer. Heavy metal pollution is avoided, the preparation process is simplified and the cost is reduced.

Description of drawings

Fig. 1 is the 50 times SEM enlargement figure of polypropylene fiber fabric substrate in embodiment 1-3.

Figure 2 is a 250-fold SEM magnification of the polypropylene fiber fabric substrate in Examples 1-3.

3 is a 50 times SEM magnified view of the silver-based conductive fabric in Example 1.

4 is a 250-fold SEM magnified view of the silver-based conductive fabric in Example 1.

Figure 5 is a 2500 times SEM magnified view of the silver-based conductive fabric in Example 1.

6 is a 40,000-fold SEM magnified view of the silver-based conductive fabric in Example 1.

Figure 7 is the mechanical properties of the silver-based conductive fabric in Example 1.

FIG. 8 is a test chart of the shielding effectiveness of the silver-based conductive fabric in the X-band in Example 1. FIG.

Detailed ways

The following embodiments are only some of the embodiments of the present invention, not all of them. Therefore, the detailed description in the embodiments of the invention provided below is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or commonly used in this industry. The methods in the following examples, unless otherwise specified, are conventional methods in the art.

Example 1:

Preparation of metal-organic ink: Weigh 0.03 mol of silver acetate in a beaker, then slowly drop 0.06 mol of ethylenediamine into the beaker containing silver acetate, while stirring continuously at a rate of 300 rpm. After stirring for 10 minutes, cool to room temperature, slowly add 0.3 mol of ethylene glycol into the mixed solution, stir for 30 minutes, the stirring speed is 300 rpm, the color of the mixed solution gradually changes from grayish black to transparent. Finally, the prepared mixed solution is centrifugally filtered to remove suspended impurity particles to obtain metal silver organic decomposition ink.

Preparation of conductive fabric: Clean the polypropylene fiber fabric substrate (see Figure 1 and Figure 2 for its SEM images) with deionized water, then soak it in the above-mentioned metallic silver organic decomposition ink for one hour, then take it out and put it in a vacuum oven at 200°C Anneal for 10 minutes, during the annealing process: the silver ions in the metal ink are reduced and sintered to form a conductive path, and a silver-based conductive fabric is obtained (see Figure 3, Figure 4, Figure 5, and Figure 6 for the SEM images). By comparing the SEM images of the original polypropylene fiber fabric substrate and the silver-based conductive fabric, it can be seen in the SEM image with a magnification of 2500 times in Figure 5 that silver has formed a dense and continuous conductive network after sintering; while the magnification of Figure 6 is In the 40,000X SEM image, it can be seen that the silver particles formed after the annealing of the metal silver organic decomposition ink are partially embedded in the fabric, forming an embedded structure, which provides good interface bonding.

Performance Testing:

The mechanical properties of the polypropylene fiber fabric base and the conductive fabric adopted in the present embodiment are measured by DMAQ800 instrument: the tensile strength of the polypropylene fiber fabric base is 26MPa, and the elongation at break is 25%; The tensile strength was 43MPa, and the elongation at break was 17% (see Figure 7 for test results).

The conductivity of the silver-based conductive fabric prepared in this example is 1.35×10 ² S/cm measured by the four-probe method, and its shielding in the X-band (8.2-12.5GHz) is measured by the rectangular waveguide method. The performance is 63dB (see Figure 8 for test results).

Example 2:

Preparation of metal-organic ink: Weigh 0.03mol copper formate in a beaker, then draw 0.06mol N,N-dimethylformamide slowly drop into the beaker containing copper formate, while stirring continuously, the stirring rate is 300 rpm Minutes, after stirring for 10 minutes, cool to room temperature, slowly add 0.3mol ethylene glycol to the mixed solution, stir for 30 minutes, the stirring speed is 300 rpm, the color of the mixed solution is light blue. Finally, the prepared mixed solution is removed by injection filtration to remove suspended impurity particles to obtain the metal copper organic decomposition ink.

Preparation of conductive fabric: Clean the base of the polypropylene fiber fabric with deionized water, soak it in the above metal copper organic decomposition ink for one hour, then take it out and put it in a vacuum oven for annealing at 200°C for 10 minutes. During the annealing process, the metal ink The copper ions are reduced and sintered to form a conductive path to obtain a copper-based conductive fabric.

Performance Testing:

Mechanical properties of the copper-based conductive fabric prepared in this example: the tensile strength is 35 MPa, and the elongation at break is 8%.

The conductivity of the copper-based conductive fabric prepared in this example is 8.72×10 ¹ S/cm measured by the four-probe method, and its shielding effectiveness in the X-band (8.2-12.5GHz) is measured by the rectangular waveguide method is 45dB.

Example 3:

Preparation of metal-organic ink: Weigh 0.03mol of nickel acetate in a beaker, then slowly drop 0.06mol of ethylenediamine into the beaker containing nickel acetate, while stirring continuously at a stirring rate of 300 rpm, after stirring for 10 minutes After cooling to room temperature, slowly add 0.3 mol of ethanol to the mixed solution, and stir for 30 minutes at a stirring rate of 300 rpm. Finally, the prepared mixed solution is centrifugally filtered to remove suspended impurity particles to obtain a clarified metallic nickel organic decomposition ink.

Preparation of conductive fabric: Clean the polypropylene fiber fabric base with deionized water, soak it in the above-mentioned metal nickel organic decomposition ink for one hour, then take it out and put it in a vacuum oven for annealing treatment at 200°C for 10 minutes. During the annealing process: metal ink The nickel ions in the fabric are reduced and sintered to form a conductive path to obtain a nickel-based conductive fabric.

Performance Testing:

Mechanical properties of the nickel-based conductive fabric prepared in this example: the tensile strength is 30 MPa, and the elongation at break is 11%.

The conductivity of the nickel-based conductive fabric prepared in this example is 4.75 S/cm measured by the four-probe method, and its shielding effectiveness in the X-band (8.2-12.5 GHz) is measured to be 32 dB by the rectangular waveguide method.

The above is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent transformations made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields, are the same as The theory is included in the patent protection scope of the present invention.

Claims

A metal-organic decomposition ink, characterized in that the metal-organic decomposition ink includes a metal salt precursor, a complexing agent and an organic solvent carrier;

The metal salt precursor is selected from any one of copper salt precursor, silver salt precursor, aluminum salt precursor and nickel salt precursor;

The complexing agent is selected from any one or several of organic amines;

The organic solvent carrier is selected from any one or several alcohols;

The decomposition temperature of the metal organic decomposition ink is 150-200°C.
The organometallic decomposition ink according to claim 1, wherein the copper salt precursor is selected from any one of copper acetate, copper formate, copper glycolate, copper chloride, copper oleate and copper hydroxide ;

Preferably, the silver salt precursor is selected from any one of silver decanoate, silver oxide, silver carbonate, silver tartrate, silver hexafluoroacetylacetonate-cyclooctadiene, silver sulfate and silver nitrate;

Preferably, the aluminum salt precursor is selected from any one of aluminum trichloride and aluminum sulfate;

Preferably, the nickel salt precursor is selected from any one of nickel acetate, nickel sulfate, nickel halide, nickel sulfamate, nickel bromide and nickel hydroxide;

Preferably, the organic amine is selected from methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, ethylenediamine, ammonium hydroxide, triethanolamine, ethanolamine, N,N-dimethylformamide and iso Any one or more of propionate;

Preferably, the alcohols are selected from the group consisting of methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, glycol ether, glycerin, diethylene glycol, triethylene glycol, β-terpineol, γ-terpene Any one or several of pinol and delta-terpineol.
The metal organic decomposition ink according to claim 1, characterized in that, in the metal organic decomposition ink, the molar ratio of the metal ion in the metal salt precursor to the complexing agent is ≤1:2;

Preferably, the molar ratio of the metal salt in the metal salt precursor to the organic solvent carrier is 1:1-10.
According to the preparation method of the arbitrary described metal organic decomposition printing ink of claim 1-3, it is characterized in that, comprises the steps:

After mixing the complexing agent and the metal salt precursor, stirring once, adding an organic solvent carrier after cooling, and stirring again.
The preparation method according to claim 4, characterized in that, the rotational speed of the primary stirring is 100-1000 rpm, and the stirring time is 10-60 minutes;

Preferably, the rotation speed of the secondary stirring is 100-1000 rpm, and the stirring time is 10-60 minutes.
The preparation method according to claim 4, further comprising an impurity removal operation.
A method for preparing a conductive fabric based on metal-organic decomposition ink, characterized in that it comprises the following steps: soaking the fabric base in the metal-organic decomposition ink, and then annealing to obtain a conductive fabric;

Wherein, the metal organic decomposition ink is the metal organic decomposition ink described in any one of claims 1-3.
The preparation method according to claim 7, characterized in that, the soaking time is 10min to 24h;

Preferably, the temperature of the annealing is 150-200° C., and the time is 10-60 minutes;

Preferably, the annealing is vacuum annealing.
The conductive fabric based on metal organic decomposition ink obtained by the preparation method according to claim 7.
The use of the conductive fabric based on metal organic decomposition ink according to claim 9 as an electromagnetic shielding material.