KR20210029886A - Metal plated carbon fibers by non-electroplating process and manufacturing method thereof - Google Patents

Abstract

Electroless metal plated carbon fibers and a manufacturing method thereof are provided. In the electroless metal plated carbon fibers according to an embodiment of the present invention, metal is plated on carbon fibers by dipping the carbon fibers in an electroless plating solution, wherein the thickness of the metal plated on the carbon fibers is 0.3 to 1.0 μm.

Description

Electroless metal plating carbon fiber and its manufacturing method {METAL PLATED CARBON FIBERS BY NON-ELECTROPLATING PROCESS AND MANUFACTURING METHOD THEREOF}

The present invention relates to an electroless metal plated carbon fiber and a method of manufacturing the same.

Carbon fiber materials have limited applications due to low electrical conductivity problems compared to high strength, high elasticity, ultra-lightweight, and high-temperature strength retention compared to excellent physical properties. To solve this problem, metal is coated on carbon fiber by a physical or chemical method in order to apply it to electromagnetic wave shielding and heating elements.

As a physical method, a typical CVD process or sputtering method can increase the bonding strength between carbon fiber and metal, but has a disadvantage in that it does not have price competitiveness due to high production cost due to non-uniform coating of metal and high energy consumption.

On the other hand, there are electrolytic plating and electroless plating as a chemical method.

In the case of electrolytic plating, a method of depositing metal on the surface of carbon fibers by electric energy has a non-uniform thickness, and there are restrictions on plating depending on the shape of the product.

And, in the case of a method of continuously performing electroless plating and electrolytic plating, there is a disadvantage that the plating bath of the electrolytic plating bath must be frequently replaced by contaminating the electrolytic plating bath after the electroless plating.

Thus, although electroless plating is most often used to manufacture carbon fibers, it is necessary to secure electrical conductivity in the metal film, and it is difficult to control the plating thickness.

Republic of Korea Patent Publication No. 2018-0006523 (published on January 18, 2018) Korean Patent Registration No. 1197723 (registered on Oct. 30, 2012)

The present invention is to solve the above problems, and provides an electroless metal plated carbon fiber capable of forming a plated layer having a predetermined thickness on the surface of the carbon fiber, and a method of manufacturing the same.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

The electroless metal plated carbon fiber according to an embodiment of the present invention for achieving the above object is plated with a metal on the carbon fiber by immersing the carbon fiber in an electroless plating solution, and the metal plated on the carbon fiber It is characterized in that the thickness is 0.3 ~ 1.0 ㎛.

In addition, the carbon fiber may be a continuous carbon fiber having a predetermined length, and the fiber diameter may be 1 to 10 μm.

In addition, the metal may be characterized in that at least one selected from the group consisting of copper (Cu), nickel (Ni), and silver (Ag).

A method of manufacturing an electroless metal plated carbon fiber according to an embodiment of the present invention for achieving the above object comprises the steps of: surface-treating the carbon fiber by immersing it in ozone water; Dispersing the ozone water by irradiating ultrasonic waves; And immersing the carbon fiber in an electroless plating solution to plate a metal on the carbon fiber.

In addition, the step of surface treatment may be characterized in that it is immersed in ozone water having an ozone concentration of 10 to 60 ppm and a temperature of 5 to 50 °C for 3 minutes or more.

In addition, the step of performing the dispersion treatment may be characterized by irradiating ultrasonic waves of 19 to 21 kHz at 270 to 290 W for 25 to 35 minutes.

And, the step of the plating treatment, the carbon fiber with at least one metal salt selected from NiCl2, NiSO4, CuSO4, CuCN, AgNO3 and AgCN, NaH2PO2 of 40 ~ 150 g / ℓ concentration, and 40 ~ 150 g / ℓ concentration It may be characterized in that the metal is electrolessly plated on the carbon fiber by immersing in an electroless plating solution of pH 5 to 9 containing Na3C6H5O7 or NaCO2CH3.

Other specific details of the present invention are included in the detailed description and drawings.

According to the present invention, it is possible to form a plated layer of a certain thickness on the surface of the carbon fiber by electroless plating carbon fiber, thereby producing a metal-plated carbon fiber excellent in economy and electrical conductivity.

1 is a view photographing a carbon fiber plated by an electroless plating method.
2 is a flow chart of a method of manufacturing an electroless metal plated carbon fiber according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention belongs. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

Although the first, second, etc. are used to describe various elements, components and/or sections, of course, these elements, components and/or sections are not limited by these terms. These terms are only used to distinguish one element, component or section from another element, component or section. Therefore, it goes without saying that the first element, the first element, or the first section mentioned below may be a second element, a second element, or a second section within the technical scope of the present invention.

The terms used in the present specification are for describing exemplary embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprises" and/or "made of" a referenced component, step, operation and/or element is one or more of the other elements, steps, operations and/or elements. It does not exclude presence or addition.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a view photographing a carbon fiber plated by an electroless plating method.

In the electroless metal plating carbon fiber according to an embodiment of the present invention, metal is plated on the carbon fiber by immersing the carbon fiber in an electroless metal plating solution. Carbon fiber plated by electrolytic plating method shows non-uniformity of metal plated on carbon fiber and very high resistance of carbon fiber, while carbon fiber plated by electroless plating method can form a plated layer of a certain thickness on the surface. And can have excellent electrical conductivity.

The carbon fiber may be at least one selected from PAN-based, pitch-based, and rayon-based carbon fibers, and carbon nanofibers.

In addition, the carbon fiber may have a one-dimensionally elongated structure, and the carbon fiber may be a continuous carbon fiber having a predetermined length.

In addition, the fiber diameter of the carbon fiber may be 1 ~ 10μm.

In particular, in order to activate the surface of the carbon fiber before electroless plating, the carbon fiber used in the electroless plating may be subjected to a pretreatment of removing impurities from the surface.

For example, carbon fibers can be immersed in a solution in which ozone is dissolved. At this time, in order to immerse the continuous carbon fibers in ozone water, the carbon fibers may have a shape rolled into a circular or elliptical shape. The carbon fiber becomes a surface condition suitable for electroless plating by ozone treatment. Specifically, carbon fibers react with ozone to generate OH groups, COOH groups, CO groups, and the like, and may be hydrophilic. As the carbon fiber becomes hydrophilic, the adhesion of metal becomes easier by electroless plating. In this way, by pretreatment using ozone water, electroless plating can be performed at low cost without affecting the environment.

In addition, pretreatment of removing impurities from the surface may be performed by activating the surface of the carbon fiber with SnCl2, PdCl2, or the like. Specifically, tin (Sn) or palladium (Pd) nuclei are formed on the surface of the carbon fiber, and these nuclei may serve to catalyze metal precipitation.

In this case, it is preferable that the thickness of the metal plated on the carbon fiber is 0.3 to 1.0 μm. At a thickness of less than 0.3 μm, sufficient electrical conductivity could not be obtained, and coating non-uniformity and a state in which the coating was peeled off the surface were observed. In addition, when the thickness exceeds 1.0 μm, the flexibility of the carbon fiber may be lost and hardened.

In particular, as shown in FIG. 1, when the thickness of the metal layer of the metal-plated carbon fiber is 0.5 to 0.7 µm, the amount of metal plating per 1 g of the carbon fiber is 1,000 to 2,000 mg.

In addition, when the thickness of the metal is 0.3 to 1.0 ㎛, the amount of metal plating per 1 g of carbon fiber is 500 to 4,000 mg. In particular, if the amount of metal plating is less than 500 mg/g, the plating layer is not evenly formed on the surface of the carbon fiber, resulting in poor electrical conductivity. If the amount of metal plating exceeds 4,000 mg/g, the metal plating layer formed on the surface of the carbon fiber is too thick. It is roughened or friction occurs between adjacent plated carbon fibers. From this, a crack phenomenon or a peeling phenomenon may occur, and a problem of deteriorating the formability of the metal-plated carbon fiber occurs. Therefore, it is preferable that the thickness of the metal plating layer to be plated on the carbon fiber is 0.3 to 1.0 µm.

Here, the metal may be at least one selected from the group consisting of copper (Cu), nickel (Ni), and silver (Ag). That is, the metal plating layer may be formed of only one of copper (Cu), nickel (Ni), and silver (Ag), or may be a double plating layer or more. In this case, in the case of a multiple plating layer, it may be formed of a double plating layer or a triple plating layer sequentially plated with different metals. For example, Ni may be used as a first plating layer, Cu may be used as a second plating layer, and Ag may be used as a third plating layer.

Specifically, in order to form a metal plating layer, carbon fibers are added to an electroless metal plating solution containing at least one metal salt selected from copper (Cu), nickel (Ni), and silver (Ag), a reducing agent, and a complexing agent. Can be immersed. Metal (at least one or more of copper, nickel, and silver) ions of the metal salt are adsorbed on the surface of the carbon fiber by the reducing agent to form a metal plating layer. In addition, the reducing agent may be hydrazine, a borohydride compound, a cobalt-ethylenediamine complex, Na3C6H5O7, NaCO2CH3, or the like. In addition, as the complexing agent, NaH2PO2, Na3C6H5O7, or the like may be used. In addition, the electroless metal plating solution may further include a small amount of a stabilizer. At this time, the stabilizer may use PbNO3 or the like.

2 is a flow chart of a method of manufacturing an electroless metal plated carbon fiber according to an embodiment of the present invention.

Referring to FIG. 2, in the method of manufacturing an electroless metal plated carbon fiber according to an embodiment of the present invention, the carbon fiber is surface-treated by immersing it in ozone water (S10), and the ozone water is irradiated with ultrasonic waves to perform dispersion treatment ( S20), the carbon fiber is immersed in an electroless plating solution to plate a metal on the carbon fiber (S30).

In the case of surface treatment (S10), it can be immersed in ozone water having an ozone concentration of 10 to 60 ppm and a temperature of 5 to 50° C. for 3 minutes or more. First, if the ozone concentration is less than 10 ppm, there is no effect of ozonated water treatment even if time elapses, and if it exceeds 60 ppm, it is difficult to dissolve ozone further. In addition, when the temperature is less than 5° C., the reaction rate becomes slow and ozone is not sufficiently treated, and when it exceeds 50° C., it is difficult to dissolve ozone so that the pre-ozone treatment effect can be exhibited. And, when the immersion time is less than 3 minutes, hydrophilization by ozone does not occur.

Here, it is preferable to use carbon fibers having a fiber diameter of 1 to 10 μm. That is, in order to increase processability and dispersibility, continuous carbon fibers having a diameter of 1 to 10 μm of a predetermined length are preferred, and if the fiber diameter deviates from 1 to 10 μm, the fibers are dispersed in a network type that connects the fibers to each other. Therefore, it is impossible to obtain a low surface resistance. In addition, the carbon fiber is preferably 50 to 100 parts by weight relative to 100 parts by weight of ozonated water for a hydrophilic effect due to ozone water.

In the case of dispersion treatment (S20), ultrasonic waves of 19 to 21 kHz can be irradiated at 270 to 290 W for 25 to 35 minutes. For example, by dispersing carbon fibers in ozone water by ultrasonic waves using a bath type sonicator, it is possible to promote hydrophilization by ozone and remove impurities on the surface of carbon fibers. At this time, even if ultrasonic waves were irradiated outside the range of 19 to 21 kHz at 270 to 290 W, the effect of removing impurities on the surface of the carbon fiber did not appear. In addition, if the usage time of the ultrasonic irradiation time is insufficient, the hydrophilic effect of ozone water may not occur properly on the carbon fiber, and if the usage time is excessive, the surface of the carbon fiber goes beyond the removal of impurities on the surface of the carbon fiber by excessive ultrasonic waves. The destruction of can proceed.

In the case of plating treatment (S20), carbon fibers are treated with at least one metal salt selected from NiCl2, NiSO4, CuSO4, CuCN, AgNO3 and AgCN, NaH2PO2 at a concentration of 40 ~ 150 g/ℓ, and Na3C6H5O7 at a concentration of 40 ~ 150 g/ℓ. Alternatively, metal may be electrolessly plated on the carbon fiber by immersion in an electroless plating solution containing NaCO2CH3 and pH 5 to 9.

By the surface treatment, dispersion treatment, and plating treatment described above, the thickness of the metal-plated plating layer becomes 0.3 to 1.0 µm. When the thickness of the metal plating layer is 0.3 ~ 1.0 ㎛, the plating amount of metal per 1 g of carbon fiber is 500 ~ 4,000 mg, and the plating layer is formed evenly on the surface of the carbon fiber, from which it is possible to prevent cracking and deterioration of formability. have. Therefore, it is preferable that the thickness of the metal plating layer to be plated on the carbon fiber is 0.3 to 1.0 µm.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features. You will be able to understand. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects.

S10: surface treatment step
S20: distributed processing step
S30: plating treatment step

Claims (7)

Metal is plated on the carbon fiber by immersing the carbon fiber in an electroless plating solution,
Electroless metal plating carbon fiber, characterized in that the thickness of the metal plated on the carbon fiber is 0.3 ~ 1.0 ㎛. The method of claim 1,
The carbon fiber,
It is a continuous carbon fiber of a predetermined length, characterized in that the fiber diameter is 1 ~ 10μm, electroless metal plated carbon fiber. The method of claim 1,
The metal is,
Copper (Cu), nickel (Ni), and characterized in that at least one selected from the group consisting of silver (Ag), electroless metal plated carbon fiber. Surface treatment by immersing the carbon fibers in ozone water;
Dispersing the ozone water by irradiating ultrasonic waves; And
A method of manufacturing an electroless metal plated carbon fiber comprising the step of plating a metal on the carbon fiber by immersing the carbon fiber in an electroless plating solution. The method of claim 4,
The step of surface treatment,
A method for producing an electroless metal plated carbon fiber, characterized in that it is immersed in ozone water having an ozone concentration of 10 to 60 ppm and a temperature of 5 to 50 °C for 3 minutes or more. The method of claim 4,
The step of performing the dispersion treatment,
Method for producing an electroless metal-plated carbon fiber, characterized in that irradiation of 19 to 21 kHz ultrasonic waves at 270 to 290 W for 25 to 35 minutes. The method of claim 4,
The plating treatment step,
PH 5 containing the carbon fiber at least one metal salt selected from NiCl2, NiSO4, CuSO4, CuCN, AgNO3 and AgCN, NaH2PO2 at a concentration of 40 to 150 g/L, and Na3C6H5O7 or NaCO2CH3 at a concentration of 40 to 150 g/L A method for producing an electroless metal plated carbon fiber, characterized in that the metal is electrolessly plated on the carbon fiber by immersing in the electroless plating solution of ~9.

Images