KR20010026385A - Conducting fibers to screen electromagnetic wave and method to make them - Google Patents

Abstract

PURPOSE: A conductive fiber for blocking electron wave and a preparing method thereof are provided. CONSTITUTION: The conductive fiber is comprised of: a copper layer(20) formed on a basic fiber(10) and a nickel layer(30) formed on the copper layer(20). The conductive fiber is obtained by a process containing the steps of: (the first step) removing impurity from the basic fiber; (the second step) etching the basic fiber; (the third step) settling a solution added hydrochloric acid to a mixed solution of palladium chloride and tin chloride on the etched basic fiber, followed by removing the produced tin to form core on the basic fiber with only the palladium; (the fourth step) forming the copper layer on the basic fiber by a non-electrolytic method; and then (the fifth step) forming the nickel layer on the copper layer by the non-electrolytic method.

Description

Conductive fibers to screen electromagnetic wave and method to make them

The present invention relates to a conductive fiber for electromagnetic wave shield, and more particularly, to a conductive fiber having a function capable of absorbing and shielding electromagnetic waves by double-plating non-electrolytically on mesh-like fibers and a method of manufacturing the same.

Various electronic products such as home appliances, computer terminals, electronic medical devices, and electronic devices of automobiles, which are used as essential daily necessities in the modern society, generate various harmful electromagnetic waves in addition to the net function to promote the convenience of life, so that workers or users The development of more effective electromagnetic wave shielding device or electromagnetic wave blocking method is required in that it also has a dysfunction causing various disease syndrome.

Electrostatic shielding and the like are most effective for inducing and absorbing or shielding electromagnetic waves, but most electronic products have an interface between a person and a device. Therefore, it is practically impossible to completely block electromagnetic waves only by using such a shield plate. In particular, it is almost impossible to use a shielding plate to block electromagnetic waves generated in an automobile or the like, and in reality, there is no example of using a shielding plate as an electromagnetic wave shielding device.

Therefore, as the most useful approach to the interface between a person and a device, it may be considered to manufacture and use a computer terminal, special clothing, an apron, a hat, and glasses using conductive fibers or fibrous materials. In the process of weaving, we used a method such as weaving an ultra-fine copper wire together with fibers, but the fiber of such a composition is excessively strong and inflexible, causing unpleasant contact with the human body. It is extremely limited, heavy, and disadvantageous in terms of price and stability.

On the other hand, the technology for plating a conductive metal such as copper on the synthetic fiber has been developed and used in part, and its use is also increasingly diversified. However, a conductive metal plated with a single layer of copper on a synthetic fiber is easily oxidized in air, and has a problem in that the effectiveness of electromagnetic shielding is easily reduced because it is not properly protected from corrosion by organic solvents and abrasion due to long-term use.

In addition, conventionally known fibrous metal plating is known as electroplating, which uses a method of attaching a coating object to the cathode by using electricity to forcibly attract and ionize metal ions. There was a problem that it is difficult to raise the thickness of the plating thickly in time.

The present invention has been made to solve the above problems, an object of the present invention by sequentially electroless double-plating copper and nickel on a fiber substrate containing a synthetic fiber to maintain the inherent flexibility and at the same time give the conductivity It is to provide a conductive fiber that can be usefully used as an electromagnetic wave shielding agent by improving oxidation resistance, corrosion resistance and abrasion resistance.

Another object of the present invention is to provide a method for producing a conductive fiber significantly reduced plating speed by sequentially double-plating copper and nickel in a fiber base including a synthetic fiber in an electroless manner.

The conductive fiber for electromagnetic wave blocking according to the present invention for achieving the above object is a copper layer having excellent conductivity is formed on the base fiber, and the nickel layer excellent in oxidation resistance, corrosion resistance and abrasion resistance while conductivity is comparable to copper on the copper layer. Characterized in that it is formed, the method for producing a conductive fiber for blocking electromagnetic waves according to the present invention comprises a first step of removing impurities from the base fiber comprising a synthetic fiber; A second step of etching the substrate fiber from which the impurities are removed; A third step of forming a nucleus on the base fiber by only palladium as a catalyst by depositing a solution of hydrochloric acid added to the mixed solution of palladium chloride and tin chloride on the etched base fiber and removing the generated tin; A fourth step of forming a copper layer on the substrate fiber on which the palladium nucleus is formed in an electroless manner; And forming a nickel layer on the copper layer in an electroless manner.

1 is a cross-sectional view of the conductive fiber for blocking electromagnetic waves according to the present invention.

2 is a flow chart showing a first embodiment of the method for producing a conductive fiber for electromagnetic wave blocking according to the present invention.

3 is a flow chart showing a second embodiment of the method for producing a conductive fiber for electromagnetic wave blocking according to the present invention.

<Description of the code | symbol about the principal part of drawings>

10: base fiber 20: copper layer

30: nickel layer

The conductive fiber for electromagnetic wave blocking according to the present invention is produced through the following steps.

First of all, for ease of plating, treatment with a reagent such as caustic soda (NaOH) reduces weight by about 5-18%, optionally through roughening, for example, mesh or polytwill. (substrate fibers including polytwill, taffeta, rib stop, nonwoven fabric, etc.) using 0.3-0.8 wt% caustic soda (NaOH) and 3.0-8.0 wt% nonionic surfactant 4-5 minutes at 30-45 ℃ to remove dust, grease and fingerprints during handling.

In order to remove the oxide attached to the fiber or chemically bonded to the fiber without removing the impurity removal step and to remove the tip of the finely damaged fiber, the substrate fiber from which the impurity is removed is washed with hydrochloric acid (HCl). It is etched with a mixed solution of nitric acid.

After washing the etched substrate fibers, a solution of hydrochloric acid was added to a mixed solution of palladium chloride (PdCl ₂ ) as a catalyst for plating and tin chloride (SnCl ₂ ) as a catalyst additive at 25-40 ° C. Immerse for 10 minutes and remove the resulting tin. At this time, the remaining tin is removed by depositing in a caustic soda solution at room temperature to form nuclei of only the catalyst, paradium.

The copper layer was immersed in an electroless manner by washing the substrate fiber having the palladium nucleus and immersing a solution containing copper sulfate, caustic soda, Rochelle salt and formalin at 40-50 ° C. for 10-15 minutes. It is formed to a thickness of 0.6 mu m.

The base fiber with the copper layer formed thereon was washed with water, and a mixed solution of nickel sulfate, citric acid and sodium hypophosphite was deposited at 30-40 ° C. for about 10 minutes, and the nickel layer was approximately 0.2 μm in an electroless manner. Form to thickness.

Electromagnetic wave shielding conductive fiber prepared through the above steps is formed with a copper layer having excellent conductivity on the substrate fiber, and has a conductivity comparable to copper on the copper layer, and a nickel layer having excellent oxidation resistance, corrosion resistance and abrasion resistance. The electrical resistance value is 0.5-1.0 mm, and the thickness of the metal film is about 0.5-0.8 μm, so that a fine coating layer can be obtained on the base fiber, thereby obtaining a conductive fiber having electrical conductivity and electrical conductivity. do.

Meanwhile, instead of double-plating copper-nickel on the base fiber as described above, triple-plating of nickel-copper-nickel may be performed, and the thicker the plating, the better the electromagnetic wave shielding effect, and the better adhesion of nickel than copper. Since it is excellent, the adhesion of the whole plated product is particularly excellent.

On the other hand, if necessary, gold or silver coating may be performed by electrolytic or electrolessly to further reinforce the metal coating layer and increase conductivity.

In addition, since the fine model of the surface of the fiber that affects the plating may vary depending on the type of fiber or the weaving method, after the substrate fiber is etched with the mixed solution of hydrochloric acid and nitric acid, only the excess hydrochloric acid solution is used. The etching may be further performed.

Since the conductive fiber produced by the electroless method according to the present invention forms a coating around the nucleus on the fiber body in which the conductive layer is a non-conductor, it provides conductivity without changing the properties of the base fiber itself such as flexibility and strength. It can be used for various purposes, for example, clothes for electrostatic shielding in semiconductor assembly workshops, glasses for mesh type work, wallpaper for electromagnetic wave shielding, various EMI It can be used in process gaskets.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the conductive fiber and the manufacturing method for electromagnetic wave blocking according to the present invention will be described in detail.

Example 1

The net base fiber 11 woven from a polyester fiber material is treated with 0.5 wt% caustic soda and 5.0 wt% nonionic surfactant at 40 ° C. for 5 minutes to remove impurities on the base fiber 11. (S1). The substrate fiber 11 from which the impurities were removed was sufficiently washed with hot water at about 65 ° C., and then etched at room temperature in a solution of 50 mL of hydrochloric acid and 10 mL of nitric acid (S2). After washing the etched substrate fiber 11, a solution containing 2 g / L of palladium chloride and 2 g / L of tin chloride was added to the same ratio of hydrochloric acid, which was then immersed at 35 DEG C for about 10 minutes, and the resulting tin was removed. Next, the remaining tin was removed by depositing at room temperature in a caustic soda 50g / L solution (S3). 20 g / L of copper sulfate, 40 g / L of caustic soda, 160 g / L of lotel salt, and 37% of formalin were deposited in a mixed solution at 40-50 ° C. for 12 minutes to form a copper layer 12 (S4). . The thickness of the copper layer 12 formed at this time was about 0.6 μm. After washing the base fiber 11 having the copper layer 12 formed thereon, it was immersed in a solution of 20 g / L nickel sulfate, 15 g / L citric acid and 30 g / L hypophosphite at a temperature of 35 ° C. for about 10 minutes to give about 0.2 μm. A nickel layer 13 having a thickness of was formed (S5).

The conductive fiber produced as described above satisfies the inherent flexibility and exhibits an electrical resistance of 0.3 m 3 and an electromagnetic shielding effect of about 50 dB.

Example 2

After the step S1 of removing impurities from the base fiber 11, 20 mL of hydrochloric acid and 5 mL of nitric acid were etched at 40 ° C. for about 20 minutes (S21), followed by washing with water again. The conductive fiber for blocking electromagnetic waves of the present invention was manufactured in the same manner as in Example 1 except that the secondary etching (S22) was performed by dipping for a minute.

The conductive fiber prepared as described above, while satisfying the inherent flexibility of the fiber, exhibited an electrical resistance value of 0.5 dBm, and exhibited an electromagnetic shielding effect of about 50 dB or more.

As described above, according to the conductive fiber for electromagnetic wave blocking according to the present invention, a nickel layer which provides conductivity without losing the characteristics of a conventional fiber body and which has conductivity equal to copper and has excellent oxidation resistance on the copper layer is further formed. It can be used in various fields for preventing electromagnetic waves by reducing the effect of oxidation. Especially, the mesh window for the lower part of the bonnet, the front and side of the radiator, and the various instrument panels which have not been developed yet. It can also be used as a material that can block strong electromagnetic waves generated in automobiles (mesh-window) or emitted from other vehicles.

Claims (10)

A conductive layer for electromagnetic wave blocking, characterized in that a copper layer (12) is formed on the base fiber (11), and a nickel layer (13) is formed on the copper layer (12). The conductive fiber for electromagnetic wave shielding according to claim 1, wherein a gold (Au) or silver (Ag) layer is further formed on the nickel layer (13). In the manufacturing method of the conductive fiber for electromagnetic wave blocking, A first step of removing impurities from the base fiber; A second step of etching the substrate fiber from which the impurities are removed; A third step of depositing a solution containing hydrochloric acid in a mixed solution of palladium chloride and tin chloride on the etched base fiber and removing the generated tin to form nuclei on the base fiber alone. ; A fourth step of forming a copper layer on the tin-free base fiber by electroless method; And A method of manufacturing a conductive fiber comprising a fifth step of forming a nickel layer on the copper layer in an electroless manner. 4. The method of claim 3, wherein the first step is performed by treating the base fiber with caustic soda and a nonionic surfactant. The method for producing a conductive fiber according to claim 3 or 4, wherein the fourth step is performed by depositing a mixed solution of copper sulfate, caustic soda, Rochelle salt, and formalin. 6. The method of manufacturing a conductive fiber according to claim 5, wherein said fifth step is performed by immersing a mixed solution of nickel sulfate, citric acid and sodium hypophosphate. 7. The method of manufacturing a conductive fiber according to claim 6, wherein the triple plating is performed by changing the order of the fourth step and the fifth step and further performing the fifth step. The method of claim 6, further comprising forming a gold (Au) or silver (Ag) layer after the fifth step. 9. The method of claim 6, further comprising depositing the etched base fiber in a hydrochloric acid solution to perform a secondary etching between the second step and the third step. 10. The manufacturing method of the conductive fiber made into. The method of manufacturing a conductive fiber according to claim 9, further comprising a step of washing between steps.