KR102563946B1 - Coating composition, conductive fiber aggregate manufactured therewith and method for manufacturing the conductive fiber aggregate - Google Patents

Abstract

The present invention relates to a coating composition, and more particularly, as a coating layer is easily formed even at a relatively low heat treatment temperature, it is possible to prevent damage to a support member due to heat treatment, and a coating layer due to the coating composition on the inner surface of the support member As it has excellent formability and excellent adhesiveness even without a separate binder component, it is possible to manufacture a conductive fiber assembly with excellent durability, and excellent electromagnetic wave shielding performance by significantly increasing the specific surface area of the formed coating layer compared to the surface area of the supporting member. It relates to a coating composition capable of expressing, a conductive fiber assembly prepared through the same, and a manufacturing method thereof.

Description

Coating composition, conductive fiber aggregate manufactured therewith and method for manufacturing the conductive fiber aggregate

The present invention relates to a coating composition, and more particularly, as a coating layer is easily formed even at a relatively low heat treatment temperature, it is possible to prevent damage to a support member due to heat treatment, and a coating layer due to the coating composition on the inner surface of the support member As it has excellent formability and excellent adhesiveness even without a separate binder component, it is possible to manufacture a conductive fiber assembly with excellent durability, and excellent electromagnetic wave shielding performance by significantly increasing the specific surface area of the formed coating layer compared to the surface area of the supporting member. It relates to a coating composition capable of expressing, a conductive fiber assembly prepared through the same, and a manufacturing method thereof.

With the development of scientific civilization, the use of various electrical, electronic and communication devices for the convenience of mankind is expanding. These devices simultaneously cause various unwanted harmful factors along with the convenience of human life, and a typical example is damage from electromagnetic waves. In particular, electromagnetic waves generated from high-frequency electronic devices may adversely affect the human brain, and may cause malfunctions of electronic devices due to electromagnetic interference (EMI) with nearby electronic devices. In addition, it has been reported that when the human body is exposed to microwaves generated from household appliances such as microwave ovens for a long time, the heat action of the microwaves adversely affects the human body and causes serious consequences such as deterioration of fertility.

In order to solve the damage of electromagnetic waves, it is possible by shielding electromagnetic waves from electronic devices. As a representative shielding product, there is a shielding paint, which is a product obtained by mixing a metal or conductive material such as Ni or Cu with a polymer material to make a paint, and Korean Patent Publication No. 2015-0077238 discloses a coating composition for shielding electromagnetic waves. there is. However, the disadvantages are that the thickness of the coating film is relatively thick with low resistance compared to the plating and deposition methods, there are problems with the uniformity and fall of the coating film, and the long-term shielding effect due to oxidation is poor. Recently, as the harmful effects of electromagnetic waves are known, regulations for electromagnetic waves in each country are becoming stricter, and high performance of electromagnetic wave shielding coatings is required. Against this background, in recent years, the development of an electromagnetic wave shielding material capable of exhibiting sufficient shielding efficiency and having a good resistance value even at a low coating film thickness by coating the surface to prevent oxidation of metal and improving conductivity has been actively conducted.

However, there is a problem in that process conditions applied when forming the coating layer, for example, high temperature, pressure, etc., cause physical/chemical damage to the support member on which the coating layer is to be formed.

Accordingly, when the conditions for forming the coating layer are relaxed, the coating layer is formed only on the outer surface of the support member to which heat or pressure is applied, and the coating layer cannot be formed on the inside.

In addition, the coating layer formed on the outer surface is easily cracked and can be peeled off, so there is a problem that the electromagnetic wave shielding property through the coating layer cannot be maintained for a long period of time.

Furthermore, when the support member on which the coating layer is formed is free of shape deformation by an external force, such as a fiber assembly, the coating layer having a relatively high hardness of a certain level or more is more easily cracked and peeled. There is a problem.

Accordingly, the coating layer can be formed on the inner surface as well as the outer surface of the support member even under relaxed process conditions, and at the same time, even without a separate binder, the adhesion between the coating layer and the support member is excellent and the shape is free from cracks or peeling even when applied to the support member. There is an urgent need for research on a coating composition for shielding electromagnetic waves with less.

The present invention has been devised in view of the above, and provides a coating composition capable of preventing physical/chemical damage to a support member in the process for forming a coating layer, as the coating layer is easily formed even under a relaxed coating layer forming condition. There is a purpose.

In addition, another object of the present invention is to provide a coating composition capable of improving coating layer formation due to the coating composition on the inner surface as well as the outer surface of the support member.

In addition, another object of the present invention is to provide a coating composition capable of realizing a conductive fiber assembly having excellent durability as it has excellent adhesion even without a separate binder component.

Furthermore, another object of the present invention is to provide a coating composition capable of exhibiting excellent electromagnetic wave shielding performance by significantly increasing the specific surface area of the formed coating layer compared to the surface area of the support member.

In addition, the present invention is provided with a wide specific surface area, and exhibits excellent electromagnetic wave shielding performance according to excellent coating properties of the outer and inner surfaces of the support member, and the conductive fiber having excellent durability of the coating layer even though it is coated on the support member free of shape change. Another object is to provide an assembly, its manufacturing method, and various electronic parts and electronic devices implemented therewith.

In order to solve the above problems, the present invention provides a coating composition for forming a metal layer provided on a conductive fiber assembly, wherein the coating composition includes a first metal precursor and a second metal.

According to a preferred embodiment of the present invention, the second metal may be granular to improve the ability to form a metal layer inside the fiber assembly and the specific surface area of the metal layer. At this time, the second metal may be a metal powder having a particle diameter of 100 ~ 100 nm.

According to another preferred embodiment of the present invention, the first metal precursor includes at least one selected from the group consisting of Cu, Ni, Co, Al and alloys thereof, and the second metal is Au, Pt, Pd , Ag, Cu, Ni, and one or more selected from the group consisting of alloys thereof.

According to another preferred embodiment of the present invention, the coating composition may include the first metal precursor and the second metal in a weight ratio of 1:0.9 to 4.5.

According to another preferred embodiment of the present invention, the coating composition includes at least one dispersion solvent selected from the group consisting of ethylene glycol, glycol-based ethers and alcohols, polyvinyl alcohol (PVA), acrylic resin, urethane resin, polyester resin, At least one binder compound selected from the group consisting of polyvinylpyrronidone (PVP), ethylene vinyl acetate copolymer (EVA), and polyethylene oxide (PEO) may be further included.

According to another preferred embodiment of the present invention, the first metal precursor may be a copper precursor, and the second metal may be copper.

On the other hand, the present invention includes (1) treating the fiber aggregate with the coating composition according to the present invention; and (2) firing the coating composition to form a fiber assembly coated with a metal layer containing the first metal and the second metal.

According to a preferred embodiment of the present invention, in step (1), the coating composition may be treated in an amount of 200 to 1000 parts by weight based on 100 parts by weight of the fiber aggregate.

According to another preferred embodiment of the present invention, the firing may be performed at a temperature of 180 to 220 ° C for 1 to 30 minutes.

In addition, the present invention is a fiber assembly comprising a plurality of strands of mono yarn; and a metal layer including a first metal and a second metal and covering at least the outside of the fiber assembly.

According to a preferred embodiment of the present invention, the fiber assembly may be a yarn containing a plurality of monofilaments, or any one of woven fabric, knitted fabric, and nonwoven fabric containing a plurality of monofilaments.

According to another preferred embodiment of the present invention, the metal layer may be coated including at least a part of the surface of the mono yarn not exposed to the outside of the fiber assembly.

According to another preferred embodiment of the present invention, the second metal is provided in a granular form to improve the ability to form a metal layer inside the fiber assembly and the specific surface area of the metal layer, and the metal layer is a granular second metal and the second metal It may be formed of the first metal that connects the particles.

According to another preferred embodiment of the present invention, the mono yarn may have a diameter of 0.05 to 2.5 μm.

According to another preferred embodiment of the present invention, the particle diameter of the second metal may be 1/2 to 1/250 of the diameter of the monofilament provided in the fiber aggregate.

According to another preferred embodiment of the present invention, the first metal includes at least one selected from the group consisting of Cu, Ni, Co, Al, and alloys thereof, and the second metal includes Au, Pt, Pd, It may include at least one selected from the group consisting of Ag, Cu, Ni, and alloys thereof.

According to another preferred embodiment of the present invention, the fiber assembly may include fiber bundles including a plurality of monofilaments in warp and weft yarns, and satisfy the following conditions (a) and (b).

(a) 0.02 ≤ D (㎛) ≤ 2.5, (b) 40 × (D) ^-1.9 ≤ Y ≤ 60 × (D) ^-2.0

The D is the diameter of the mono yarn (㎛), and the Y is the number of mono yarns included per unit area (100 μm ² ) in the vertical cross section of the fabric.

According to another preferred embodiment of the present invention, the fiber aggregate may further satisfy the following condition (c).

(c)

Wherein D is the mono yarn diameter (μm), Y is the number of mono yarns included per unit area (100 μm ² ) in the vertical section of the fabric, and T is the thickness (μm) of the fabric.

In addition, the present invention provides electronic components such as conductive tapes and gaskets having the conductive fiber assembly according to the present invention, or electronic devices having the same.

According to the present invention, the coating composition according to one embodiment of the present invention can prevent physical/chemical damage to the support member in the process for forming the coating layer as the coating layer is easily formed even under the conditions for forming the relaxed coating layer. In addition, it is possible to improve the formation of a coating layer on the inner surface as well as the outer surface of the support member due to the coating composition, and at the same time, since the adhesion of the coating layer is excellent even without a separate binder component, a conductive fiber assembly with excellent durability can be implemented. there is. Furthermore, by significantly increasing the specific surface area of the formed coating layer compared to the surface area of the support member, excellent electromagnetic wave shielding performance can be expressed. In addition, it is provided with a wide specific surface area, exhibits excellent electromagnetic wave shielding performance according to the excellent coating properties of the outer and inner surfaces of the support member, and various electronic components due to the excellent durability of the coating layer even though it is coated on the support member free of shape change. , can be applied to electronic devices, etc.

1 is a flow chart of a manufacturing process of a conductive fiber assembly according to a preferred embodiment of the present invention;
Figure 2 is a view of a conductive fiber assembly according to a preferred embodiment of the present invention, Figure 2a is a partially enlarged perspective view of the conductive fiber assembly having a fiber assembly as a yarn, Figure 2b is a partial monofilament and the coating of the monofilament Figure 2c is an enlarged cross-sectional schematic diagram of some mono yarns and a metal layer coated on the mono yarns, Figure 2d is a SEM photograph showing the metal layer coated on the mono yarns,
Figure 3 is a view of a conductive fiber assembly according to a preferred embodiment of the present invention, Figure 3a is a view showing a conductive fiber assembly having a fiber assembly that is a fabric, Figure 3b is a conductive fiber assembly having a fiber assembly that is a non-woven fabric a drawing showing,
4 is a SEM picture of copper nanoparticles included in a coating composition according to a preferred embodiment of the present invention, and
5 is a schematic cross-sectional view of composite fibers for producing a fiber aggregate provided in a preferred embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein. In order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added to the same or similar components throughout the specification.

First, the coating composition according to the present invention will be described.

The coating composition is a composition for forming a metal layer provided in the conductive fiber assembly, and includes a first metal precursor and a second metal.

Conventionally, as a method of manufacturing a conductive substrate by forming a conductive layer, as described above, a method of forming a conductive layer on a substrate through a conductive coating composition and a method of forming a conductive layer through various plating or deposition methods have been used. However, the plating/deposition method has problems of oxidation of the conductive layer and weakening of adhesion. In addition, through the plating/deposition method, there is a problem in that it is not easy to form the conductive layer in the inner region of the support member having a complex and fine structure inside the conductive layer, such as a fiber assembly.

The same problem occurs in the method of forming a conductive layer through a coating composition. In particular, in the case of forming a metal coating layer through sintering in a metal precursor state, it is not very easy to form a metal coating layer inside the fiber assembly. However, there is a problem in that the metal coating layer is formed only on the outside of the fiber assembly. This is a result of poor heat resistance of the fiber assembly. Specifically, when heat is applied to the fiber assembly at a high temperature, there is a problem in that the shape deformation of the fiber assembly or the weakening of mechanical strength is caused. There is a problem with not being able to apply high temperatures. In this case, a metal layer is easily formed on the outer surface of the fiber, where even relatively low temperature heat is easily transferred, whereas heat is not easily transferred to the inside, so it is difficult to form a metal layer on the inside. When formed up to , there is a problem in that the shape of the fiber aggregate is deformed or collapsed.

When the metal layer is formed only on the outside of the fiber assembly, compared to the entire volume of the conductive fiber assembly, the improvement in conductivity is insignificant, making it difficult to achieve a desired level of electromagnetic wave shielding performance.

Accordingly, the inventors of the present invention have continued research to solve this problem, and as a result, when processing and sintering a composition in which a metal precursor and a metal are added together, it is easy to reach the inside of the fiber assembly even under relaxed process conditions that do not cause damage or deformation to the fiber assembly. A coating layer is formed, and a conductive fiber assembly having greatly improved durability such as adhesion of the coating layer has been realized, leading to the present invention.

The first all-metal precursor may be a precursor such as a metal salt for a metal selected when manufacturing a conventional conductive substrate. As an example of this, the first metal precursor may include at least one selected from the group consisting of Cu, Ni, Co, Al, and alloys thereof.

In addition, the second metal may be a metal selected when manufacturing a conventional conductive substrate, and for example, includes at least one selected from the group consisting of Au, Pt, Pd, Ag, Cu, Ni, and alloys thereof. can do.

The second metal may preferably be a granular metal powder, more preferably a metal powder having a particle size of 10 to 100 nm. Since the granular metal powder can act as a growth nucleus when the first metal precursor is sintered, the coating layer formability can be remarkably improved even in a relaxed coating condition even inside the fiber assembly where heat does not easily reach. In addition, durability can be increased by increasing the adhesion between the fiber aggregate and the coating layer. Furthermore, there is an advantage in that the specific surface area of the coating layer can be significantly increased due to the granular second metal, and through this, more improved electromagnetic wave shielding performance can be expressed. However, when the particle diameter of the metal powder is less than 10 nm, oxidation stability may be greatly reduced and conductivity may be deteriorated. Conductivity is lowered, and when the conductive fiber assembly described later is composed of fibers having a nanometer diameter, it is difficult for the second metal particles to penetrate into the space between the fibers, so the second metal is located only on the surface of the fiber assembly and inside the fiber assembly. There is a problem in that the target fiber assembly may be difficult to have excellent conductivity according to the difficulty in positioning. Meanwhile, the second metal is preferably included in the composition in a gel state to prevent oxidation of the surface of the metal particle.

The coating composition may include the first metal precursor and the second metal in a weight ratio of 1:0.9 to 4.5. If the second metal is provided in a weight ratio of less than 0.9 compared to the first metal precursor, the formation of the metal layer on the inner surface of the fiber assembly is significantly reduced, the degree of improvement in the specific surface area of the coating layer is insignificant compared to the surface area of the base material, and the sheet resistance value is There is a significant increase in the problem. In addition, if the second metal is included in a weight ratio of more than 4.5 compared to the first metal precursor, since the content of the first metal precursor is relatively small, the first metal may not be able to connect the second metal particles, In this case, there is a problem that the sheet resistance value rather increases as the second metal particles are only located in a bunch and cannot be connected to each other. Meanwhile, in this case, although the sheet resistance value increases, the resistance value may not be measured, which is due to an electrical short circuit as the metal layers are not connected to each other. In addition, since the second metal particles are not agglomerated and connected sparsely and may be provided in the support, there may be a problem in that adhesion to the fiber assembly described below is significantly lowered.

According to a preferred embodiment of the present invention, the first metal precursor may be a copper precursor, and the second metal may be copper, more preferably copper powder. When the first metal precursor and the second metal are a copper precursor and copper, respectively, they have excellent solvent dispersibility and can exhibit excellent conductivity even at a low unit price.

The coating composition may further include a dispersion solvent and a binder compound.

The dispersion solvent serves to uniformly disperse the first metal precursor and the second metal, and is a solvent capable of uniformly dispersing the two components without chemically affecting the first metal precursor and the second metal without limitation. can be used For example, the dispersion solvent may be at least one selected from the group consisting of ethylene glycol, glycol-based ether, and alcohol. The glycol-based ether is, for example, triethylene glycol dimethyl ether, triethylene glycol monobutyl ether, triethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, ethylene It may be at least one selected from the group consisting of glycol monopropyl ether and dipropylene glycol methyl ether, and the alcohol may be methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1- Propanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 2,2-dimethyl-1-propanol, 1-hexanol, cyclopentanol, 3-methyl-1- Butanol, 3-methyl-2-butanol, 2-methyl-1-butanol, 2,2-dimethyl-1-propanol, 3-hexanol, 2-hexanol, 4-methyl-2-pentanol, 2-methyl -1-pentanol, 2-ethylbutanol, 2,4-dimethyl-3-pentanol, 3-heptanol, 4-heptanol, 2-heptanol, 1-heptanol, 2-ethyl-1-hexanol , 2,6-dimethyl-4-heptanol, 2-methylcyclohexanol, 3-methylcyclohexanol, and 4-methylcyclohexanol.

In addition, the binder compound allows the second metal in the coating composition to be more easily attached to the support before sintering, and may be lost through thermal decomposition after sintering. If the binder compound is a component capable of thermal decomposition at a relatively low temperature, it may be used without limitation. For example, at least one selected from the group consisting of polyvinyl alcohol (PVA), acrylic resin, urethane resin, polyester resin, polyvinylpyrrolnidone (PVP), ethylene vinyl acetate copolymer (EVA) and polyethylene oxide (PEO) can

The dispersion solvent may be included in 600 to 700 parts by weight based on 100 parts by weight of the second metal, and the polymer compound may be included in 1 to 10 parts by weight based on 100 parts by weight of the second metal, but is not limited thereto.

Hereinafter, a method of manufacturing a conductive fiber assembly using the coating composition according to one embodiment of the present invention described above will be described.

First, as step (1) according to the present invention, the step (S100) of treating the fiber aggregate with the coating composition according to the present invention described above is performed.

As a method of treating the fiber aggregate with the coating composition, a method of treating the adhered surface with a liquid liquid in the form of a conventional ink or paste may be used. As non-limiting examples thereof, blade coating, flow coating, casting, printing method, transfer method, brushing, dipping, silk screen or spraying, etc. The coating composition can be added by the method of At this time, the coating amount may be set differently according to the degree of thickness of the metal layer to be formed, so the present invention is not particularly limited thereto. However, it may be preferably treated in an amount of 200 to 1000 parts by weight based on 100 parts by weight of the fiber aggregate. If the coating composition is treated with less than 200 parts by weight, there is a problem that the metal layer cannot be formed at a desired level. In addition, when treated in excess of 1000 weight, the thickness increases, the flexibility of the fiber assembly decreases, and the metal layer may be easily peeled off due to bending of the fiber assembly.

Next, in step (2), a step of firing the coating composition to form a fiber assembly coated with a metal layer including the first metal and the second metal is performed.

The firing in step (2) should be determined in consideration of the thermal characteristics of the fiber assembly as well as the sintering temperature of the metal precursor and metal particles in the coating composition. However, fiber-forming components forming conventional fiber aggregates are some polymer compounds, for example, except for components such as para-aramid, for example, deformation of the shape of the fiber aggregate at a temperature of 250 ° C or higher, in some cases, 230 ° C or higher. , there are problems that can cause damage. Accordingly, the sintering temperature of the metal precursor included in the coating composition cannot be increased to a desired level. Accordingly, the firing temperature is preferably 230 ℃ or less, more preferably carried out in the range of 180 ~ 220 ℃. If the firing temperature is less than 180 ° C., there is a problem in that the dispersion solvent and the polymer binder compound included in the coating composition may not be smoothly thermally decomposed and may remain in the metal layer. In addition, the metal layer may not be formed at a desired level or the adhesive force between the metal layer and the fibers may be weak. In addition, there is a problem in that cracks and the like may easily occur as the metal layer is not firmly formed. In addition, if the firing temperature exceeds 220 ° C., there is a problem in that the coating composition cannot be applied to the fiber aggregate formed of the fiber-forming component having poor thermal characteristics.

The firing may preferably be performed for 10 to 30 minutes. However, the firing time may be selected differently depending on the firing temperature, so it is not limited thereto.

On the other hand, the present invention is a fiber assembly comprising a plurality of strands of mono yarns prepared through the above-described manufacturing method; and a metal layer including a first metal and a second metal and covering at least the outside of the fiber assembly.

The fiber assembly may be a yarn containing multiple strands of monofilaments, or any one of woven, knitted and nonwoven fabrics containing multiple strands of monofilaments.

The mono yarn may be formed of a known fiber-forming component. As a non-limiting example of this, the fiber-forming component is nylon 4, nylon 6, nylon 7, nylon 11, nylon 12, nylon 66, nylon 6 10, poly-m-xylene adipamide, poly-para-xylene decaneamide, etc. of polyamides, polyesters such as polyethylene terephthalate, polytetramethylene terephthalate, polybutylene terephthalate, polyethyleneoxybenzoate, and poly 14-dimethylcyclohexane terephthalate, polyolefins such as polyethylene and polypropylene, poly One compound selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinylidene cyanide, polyacrylonitrile, and polystyrene, polyurethane, and polyurea, a mixture of two or more compounds, or two It may contain more than one species of copolymer.

The mono yarn may have a diameter of 0.02 μm or more, and the yarn may include at least two or more mono yarns.

In addition, the fabric may be woven, knitted and non-woven.

When the fabric is a fabric, the yarns may be single yarns or plied yarns to form warp and weft yarns. The fabric may be any one selected from the group consisting of plain weave, twill weave, satin weave and double weave. When the plain weave, twill weave, and satin weave are referred to as a ternary tissue, the specific weaving method for each ternary tissue is by a conventional weaving method. For example, there are ridge weave and basket weave as changeable plain weave, and new twill weave, broken twill weave, non-twill weave, mountain type twill weave, etc. there is The double weave is a weaving method of a fabric in which either one of the warp or weft is doubled or both are doubled, and a specific method may be a conventional double weaving method. However, it is not limited to the description of the fabric structure.

In addition, when the fabric is a knitted fabric, the fabric may be a knitted fabric knitted by single yarn or ply yarn. For example, it may be a weft knitted/circular knitted fabric or a warp knitted fabric, and each of the weft knitted fabric and the warp knitted fabric may have a known structure.

On the other hand, when the fabric is a non-woven fabric, it may be a non-woven fabric prepared by a known method by providing the yarn in a long fiber state or by providing a yarn cut into short fibers.

Since the basis weight and thickness of the fabric may be selected differently depending on the purpose, the present invention is not particularly limited thereto.

The metal layer is provided to cover at least the outside of the fiber assembly, including the first metal and the second metal. Specifically, as shown in FIG. 2A, when the conductive fiber assembly 100 is a yarn, the metal layer 120 is provided including the outer surface of the yarn having the plurality of mono yarns 111, 112, and 113 strands. In the metal layer 120, as shown in FIG. 2B, which partially enlarges the fourth mono yarn 114 of FIG. 2A, the surface of the mono yarn is discontinuously covered by the second metal particles 122a and 122b, and the discontinuous A metal layer may be formed by connecting the first metal 121a to the space between the second metal particles.

In addition, the metal layer may cover at least a portion of the surface of the monofilament not exposed to the outside of the fiber assembly. Specifically, as shown in FIG. 2C, which partially enlarges the first mono-yarn 111, the second mono-yarn 112, and the third mono-yarn 113 of FIG. 2A, the third mono-yarn that is not exposed to the outside of the yarn. Metal layers 121b and 122c are also formed on the outer surface of 113, and the metal layers 121b and 122c are interposed between the first monofilament 111, the second monofilament 112, and the third monofilament 113. are partially connected so that a more improved specific surface area and thus excellent electrical conductivity can be expressed. Specifically, as shown in FIG. 2D, it can be confirmed that the metal layer is formed very well on the surface of the multi-stranded mono yarn.

On the other hand, according to a preferred embodiment according to the present invention, as shown in FIG. 3A, the fiber assembly is a fabric including weft yarns 211 and warp yarns 212 including a plurality of mono yarns, and a metal layer 220 on the fabric. ) can be formed, and the fabric can satisfy the following conditions (a) and (b).

(a) 0.02 ≤ D (μm) ≤ 2.5

(b) 40×(D) ^-1.9 ≤ Y ≤ 60×(D) ^-2.0

In the condition (a), D means the diameter (㎛) of the mono yarn. Since the mono yarns 11, 12, and 13 satisfying the preferred diameter range according to the present invention are ultra-fine or nano-class ultra-fine fibers unlike conventional yarns, the external and internal specific surface areas of the fiber bundles formed by combining them are the fibers. Significantly improved compared to mono yarns of the same diameter as bundles. As the increase in the specific surface area of the fiber bundle is directly related to the increase in the area that can be coated with the conductive material, there is an advantage in that the absolute amount of the conductive material that can be provided in the fabric can be increased. In addition, in the case of ultrafine fibers coated with a conductive material and having a nanoscale diameter, there is an advantage in that electromagnetic wave removal performance can be further improved by increasing the scattering of electromagnetic waves incident to the fabric. Furthermore, in a fiber bundle formed of ultrafine fibers having a diameter of nanoscale, the gap between the fibers is also very narrow in micro or nano units, and electromagnetic waves incident toward such a narrow gap, for example, having a frequency of several to tens of Hz Since electromagnetic waves can be attenuated and shielded, there is an advantage in that electromagnetic wave removal performance can be further improved. Accordingly, it is preferable that the diameter of the monofilament included in the fiber bundle provided in the fabric satisfies the condition (a) according to the present invention. If the diameter of the mono yarn is less than 0.02㎛, it is very difficult to manufacture with the current technology level, and even if it can be realized through electrospinning, etc., compared to melt spinning, the production of yarn by electrospinning results in a decrease in productivity and a fiber-forming component that can be used. However, it is accompanied by technical problems that are difficult to wind the electrospun nanofibers like filament yarns. In addition, when the diameter of the mono yarn is too small, there may be a significant decrease in mechanical strength. In addition, the number of yarns that can be provided in the fabric of the same thickness increases and the specific surface area that can be coated with the conductive material can further increase. There is a problem in that the electromagnetic wave shielding effect is insignificant compared to the weight increase and the increased amount of the conductive material. In addition, if the diameter of the mono yarns exceeds 2.5㎛, the scattering effect of electromagnetic waves through the mono yarns can be significantly reduced, and the electromagnetic wave shielding effect is significantly reduced as a whole because the electromagnetic wave attenuation effect is not expressed through the gap between the mono yarns. There are possible problems. In addition, as the number of fibers that can be provided in the thickness direction on the cross section of the fabric decreases, there is a problem in that the electromagnetic wave shielding effect due to the multi-layered fiber structure decreases.

In addition, in the condition (b), D is the diameter of monofilament (μm), and as shown in FIGS. 2B and 2C, Y is the monofilament included per unit area (S, 100 μm ² ) in the cross section of the fabric. is the number of yarns (M).

As described above, in the case of a structure in which a conductive fiber assembly is laminated, the electromagnetic wave rejection performance is excellent depending on the difference in the amount of the conductive material coated, compared to a single-layer structure having the same thickness. In particular, there is a much structurally advantageous advantage in shielding high-frequency and broadband electromagnetic waves. Accordingly, the number of monofilaments per unit area (100㎛ ² ) in the cross section of the fabric is the condition ( b) must be satisfied. If the number of mono yarns per unit area (100㎛ ² ) in the cross section of the fabric is less than the lower limit considering the diameter of the mono yarns, the desired level of high frequency and broadband electromagnetic wave shielding performance may not be expressed. There is a problem that the removal performance cannot be expressed. In addition, if the number of mono yarns per unit area (100㎛ ² ) in the cross section of the fabric exceeds the upper limit in consideration of the diameter of the mono yarns, the amount of conductive material provided in the fabric is excessive, resulting in an increase in production cost and There is a problem in that the electromagnetic wave shielding effect is insignificant compared to the weight increase and the increased amount of the conductive material.

On the other hand, the number of mono yarns per unit area (100㎛ ² ) of the fabric is calculated by counting the mono yarns completely included in the unit area as one, and calculating the cross-sectional area of the part if it is included only partially, and then the cross-sectional area of the included mono yarns. Count the number by considering . For example, assuming that the cross-sectional area of the mono yarn is 10 μm ² , and the cross-sectional area of the mono yarn included in the unit area is 56.7 μm ² in total, the number of mono yarns included only partially over the unit area. is 56.7 μm ² /10 μm ² = 5.67 ≒ Defined as counting to 6. On the other hand, as an example, if the cross-sectional area of the mono yarn exceeds 100 μm ² , and only a portion of one mono yarn is included in the unit area (100 μm ² ), Y is counted as one. In addition, in the case of a fabric having mono yarns having different diameters, the number of mono yarns per unit area is obtained by considering the cross-sectional area of each mono yarn as described above to determine the number of mono yarns included only in part. As an example, it is a fabric provided with mono yarn A having a cross-sectional area of 2 μm ² and mono yarn B having a cross-sectional area of 6 μm ² , and assuming that some mono yarns per unit area in a vertical cross section span only a portion, the curvature for each diameter of the mono yarn According to the difference in the radius, the total cross-sectional area of the spanning mono yarn A and the total cross-sectional area of the spanning mono yarn B can be obtained and divided by each cross-sectional area to calculate the total number of spanning mono yarns.

In addition, according to a preferred embodiment of the present invention, despite being implemented to be slimmed down to suit the recent trend of light, thin, short and miniaturized low-profile parts, sufficient mechanical strength is ensured, and more improved high-frequency and broadband electromagnetic wave removal performance To express To this end, the fabric may further satisfy the following condition (c).

(c)

The D is the diameter of the mono yarn (㎛), the Y is the number of mono yarns included per unit area (100 μm ² ) in the cross section of the fabric, and T is the thickness (μm) of the fabric.

If the value of the equation in condition (c) is less than 8, the thickness of the fabric is too thin, so even if the laminated fiber structure in the cross section of the fabric is multilayered with hundreds of layers or more, the absolute structure for shielding electromagnetic waves at the desired level There is a problem that the overall electromagnetic wave removal performance is lowered because the thickness is not reached, and the mechanical strength is also significantly lowered. In addition, if the value of the equation of the condition (c) exceeds 20, the thickness of the fabric is excessive, making it unsuitable for recent light, thin, short and miniaturized electronic parts and electronic devices, and there is a problem that the unit price of the product increases. .

In addition, as shown in FIG. 3B, the fiber assembly may be a nonwoven fabric in which a plurality of mono yarns 311 are formed in a three-dimensional network structure, and a metal layer 330 is provided outside and inside the nonwoven fabric to form a conductive fiber assembly ( 300) may be implemented.

The above-described conductive fiber assembly according to the present invention may be very suitable for excellent conductivity and shielding of high frequency and broadband electromagnetic waves. Accordingly, the conductive fiber assembly according to the present invention can be applied to a gasket having the same, an electronic product having the same, and the like. In addition, the conductive fiber assembly is provided with a conventional adhesive layer on at least one surface to be implemented as an electromagnetic wave shielding tape and can be widely applied to various electronic products.

Although the present invention will be described in more detail through the following examples, the following examples are not intended to limit the scope of the present invention, which should be interpreted to aid understanding of the present invention.

<Example 1>

In order to prepare a coating composition, the first copper precursor solution prepared in Preparation Example 1 below and the copper nanoparticle gel prepared in Preparation Example 2 below were mixed so that the weight of the copper precursor and the copper nanoparticles were 1: 1. . Thereafter, ethylene glycol was added in an amount of 660 parts by weight based on 100 parts by weight of the copper nanoparticles. The mixed solution was dispersed by high-frequency vibration for 1 hour and stirred for 2 hours to prepare a dispersed coating composition as shown in Table 1 below.

* Preparation example 1

To prepare the first copper precursor solution, 9.6 g of copper acetate was added to a 10 ml solution of a mixture of ethanol and ethylene glycol in a volume ratio of 1:1 and completely dissolved by stirring. To this solution, 8 ml of cyclohexylamine was reacted by dropping for 1 minute, and after 10 minutes, 4.4 ml of formic acid was added and reacted for 1 hour to prepare a first solution in which the color of the solution changed from blue to green. .

*Preparation example 2

To prepare copper nanogel, 200ml of a mixed solvent of distilled water and ethylene glycol in a volume ratio of 1:1 was raised to 60°C, and then 2.75 g of Cu(NO ₃ ) ₂ 3H ₂ O was added and stirred to dissolve completely. . 7.5 g of polyvinylpyrrolnidone (PVP MW 40,000, SIGMA-ALDRICH) was added to the solution and vigorously stirred. 12.5 ml of hydrazine (JUNSEI) was dropped and reacted for 1 minute in the solution in which polyvinylpyrronidone was dispersed, and after stirring for 1 hour, centrifugation at 5,000 rpm for 10 minutes through a centrifuge to obtain 2 g of precipitate. As a result, it was confirmed that copper nanoparticles having an average diameter of 100 nm were generated as shown in FIG.

<Example 2>

It was prepared in the same manner as in Example 1, but the coating composition shown in Table 1 was prepared by changing the weight ratio of the copper precursor and the copper nanoparticles in the coating composition as shown in Table 1 below.

<Comparative Examples 1 to 2>

It was prepared in the same manner as in Example 1, but the coating composition shown in Table 1 was prepared without using any one of the copper precursor and copper nanoparticles in the coating composition as shown in Table 1 below.

<Production Example 1>

The coating composition prepared in Examples and Comparative Examples was coated with 600 parts by weight of the coating composition based on 100 parts by weight of the fiber assembly using a bar coater on the fiber assembly prepared in Preparation Example 3 below, and the coating composition was heated at 200 ° C. for 20 minutes under a nitrogen atmosphere. By firing, a conductive fabric as shown in Table 1 was prepared.

*Preparation example 3

First, in order to manufacture composite fibers having a cross section as shown in FIG. 5, polyethylene as a fiber-forming component 15 is used by using a sea-island spinneret capable of spinning a total of 24 composite fibers in which 37 fiber-forming parts are arranged in a single composite fiber. Terephthalate was introduced into the island component supply unit, and the alkali-soluble component prepared in Preparation Example 4 below as the elution component 22 was introduced into the sea component supply unit and melted at 285° C. to obtain a spinning temperature of 275° C. and a spinning speed of 4200 Composite spinning was performed in mpm to obtain a composite fiber bundle having a total fineness of 75 denier and 24 strands, and a fiber-forming portion having a diameter of about 2 μm in a single composite fiber.

Using the obtained composite fiber bundles as warp and weft yarns, a plain weave fabric having a warp density of 212 yarns/inch and a weft yarn density of 86 yarns/inch, with a width of 20 cm and a thickness of 0.16 mm was woven.

The woven fabric was cut into 20 cm × 20 cm in length and width, and then immersed in 90 ° C. and 5% by weight aqueous sodium hydroxide solution for 1 hour, and then a process of reducing the alkali-soluble component, which is a sea component in the composite fiber, was performed. After the weight loss, the fabric is washed with water and dried for normal fabric, then immersed in a 2% by weight aqueous solution of a surfactant (Dow Chemical, Triton20), scoured at 40 ° C for 20 minutes, washed with distilled water and dried, and then dried. An aggregate was prepared.

*Preparation example 4

Terephthalic acid (TPA) and ethylene glycol (EG) were adjusted in a 1: 1.2 molar ratio, and 1.5 moles of sodium 3,5-dicarbomethoxybenzene sulfonate were compared to the total of terephthalic acid and sodium 3,5-dicarbomethoxybenzene sulfonate. % was mixed. In addition, 10.0 parts by weight of lithium acetate as a catalyst was mixed with 100 parts by weight of sodium 3,5-dicarbomethoxybenzene sulfonate, followed by esterification at 250 ° C. under a pressure of 1140 Torr to obtain an ester reactant, The response rate was 97.5%.

The formed ester reactant is transferred to a condensation polymerization reactor, 10.0 parts by weight of polyethylene glycol (PEG) having a molecular weight of 6000 is added to 100 parts by weight of the ester reactant, and then 400 ppm of antimony trioxide is added as a condensation polymerization catalyst so that the final pressure is 0.5 Torr. A polycondensation reaction was performed by raising the temperature to 285° C. while gradually reducing the pressure, and then an alkali-soluble copolyester resin was obtained.

<Experimental Example 1>

The following physical properties of the conductive fabric prepared in Preparation Example were evaluated and are shown in Table 1 below.

1. Surface resistance

The specific resistance value was measured using a surface resistivity meter (SR2000N).

2. Formation amount of metal layer

The weight of the fiber assembly was measured before the formation of the metal layer, and the weight of the fiber assembly was measured after the formation of the metal layer, and the weight (g) of the provided metal layer was divided by the weight (g) of the fiber assembly to determine the weight of the metal layer per unit weight (g) of the fiber assembly. Calculated.

3. Adhesion evaluation

Scotch tape was attached to the prepared conductive fabric and then peeled off to evaluate the transfer state of the metal layer on the adhesive surface. As a result of evaluation, if there is no transfer on the adhesive surface of the tape ○, if less than 30% of the total area of the adhesive surface of the tape is transferred to the adhesive surface and separated from the substrate △, if more than 30% of the total area of the adhesive surface of the tape is transferred to the adhesive surface When transcribed, it is indicated by ×.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 covering
composition Copper precursor:
Copper nanoparticle weight ratio 1:1 1:0.8 1:2 1:4 1:5 Does not contain copper nanoparticles copper
Precursor Free conductivity
fiber aggregate Metal layer formation amount per unit weight of fiber aggregate
(g/g) 1.8 1.1 5.6 8.0 8.2 1.4 0.8 Properties Resistivity (Ω/□) 2.4 4.6 0.4 4 12 10 measurement
no adhesiveness ○ △ ○ ○ △ △ ×

As can be seen from Table 1 above,

It can be seen that the conductive fiber aggregate coated with the coating composition without copper nanoparticles has a specific resistance of 10 Ω/□, which is significantly lowered in physical properties compared to Example 1, and also lowered in adhesiveness.

In addition, the specific resistance of the conductive fiber assembly coated with the coating composition containing no copper precursor was not measured, which is expected because the copper nanoparticles were fired to form a metal layer, but the connectivity between them was very weak and the resistance was not measured due to an electrical short circuit. , It can be seen that the adhesiveness is very reduced compared to the examples. In particular, it can be confirmed that the weight of the metal layer formed per unit weight of the fiber assembly is very small as the adhesion of the metal layer is weak and easily detached from the fiber assembly after firing.

In addition, among the Examples, Examples 2 and 5, in which the weight ratio between the copper precursor and the copper nanoparticles in the coating composition is out of the preferred range of the present invention, have very high specific resistance and adhesiveness compared to Examples 1, 3, and 4. You can see what's not good.

<Preparation Examples 2 to 8>

A fiber assembly was prepared in the same manner as in Preparation Example 1, but the fiber assembly was prepared by changing the fiber assembly as shown in Table 2 below, and then the coating composition of Example 1 was treated and fired under the same conditions to conduct conductivity as shown in Table 2 below. A fiber assembly was prepared.

<Experimental Example 2>

The following physical properties of the conductive fiber aggregates prepared in Preparation Examples 1 to 8 were evaluated and are shown in Table 2 below.

1. Surface resistance

Specific resistance values were measured using a surface resistance meter (SR2000N) and are shown in Table 2 below. At this time, based on the specific resistance value in Preparation Example 1 as 100, the specific resistance values of the fiber aggregates according to other Preparation Examples were shown relatively.

2. Satisfaction of conditions

Satisfaction of the following conditions (a) to (c) was evaluated.

(a) 0.02 ≤ D (μm) ≤ 2.5

(b) 40×(D) ^-1.9 ≤ Y ≤ 60×(D) ^-2.0

(c)

Wherein D is the mono yarn diameter (μm), Y is the number of mono yarns included per unit area (100 μm ² ) in the vertical section of the fabric, and T is the thickness (μm) of the fabric.

At this time, after cutting the fabric in the warp direction and the weft direction, Y counted the number of monofilaments included per unit area through an SEM image of the cut surface. At this time, the number of monoyarns per unit area counted by cutting in the warp direction is displayed as the weft condition (b), and the number of monoyarns per unit area counted by cutting in the weft direction is displayed on the table as the warp condition (b). showed up

3. Formation amount of metal layer

The weight of the metal layer was calculated by measuring the weight of the fiber assembly before forming the metal layer and measuring the weight of the fiber assembly after forming the metal layer. At this time, based on the weight of the metal layer in Preparation Example 1 as 100, the weight of the metal layer of the other Preparation Examples was shown relatively.

Preparation Example 1 Preparation Example 2 Preparation Example 3 Production Example 4 Preparation Example 5 Preparation Example 6 Preparation Example 7 Preparation Example 8 yarn for weaving Fiber-forming part in composite fiber
(number/diameter (μm)) 37/2 37/2 37/2 37/2 37/2 - 37/3 37/2 composite fiber bundle
(total fineness (de')/
number of strands) 75/24 75/24 75/24 75/24 75/24 - 75/24 75/24 non-composite fiber bundle
(number/diameter (μm)) - - - - - 48/12 - - before weight loss
textile warp density
(count/inch) 212 180 170 170 620 - 212 150 weft density
(count/inch) 86 70 65 50 430 - 86 45 Thickness (㎛) 160 130 116 100 300 - 160 80 fabric after weight loss warp density
(count/inch) 188,256 159,840 150,960 150,960 550,560 122 188,256 159,840 weft density
(count/inch) 76,368 62,160 57,720 44,400 381,840 98 76,368 44,400 Thickness (㎛) 80 65 58 50 150 60 80 40 Properties Whether condition (a) is satisfied ○ ○ ○ ○ ○ × × ○ Condition (b) Scope 10.7~15 10.7~15 10.7~15 10.7~15 10.7~15 0.36~0.42 5.0 to 6.7 10.7~15 Whether condition (b) is satisfied
(Warp direction section/Weft direction section) ○
(13/13) ○
(12/12) ○
(12/12) ○
(10/10) ○
(15/15) ○
(1/1) ○ (6/6) ×
(9/9) Whether condition (c) is satisfied
(value) ○/
11.09 ○/
9.01 ○/
8.37 ×/
7.91 ×/
20.80 ×/
5.00 ○/
11.16 ○/
10.00 Resistivity (%) 100 106 109 121 94 128 126 133 Metal layer weight (%) 100 110 96 90 180 60 90 90

As can be seen from Table 2 above,

It can be seen that the conductive fiber aggregates according to Preparation Examples 6 to 8 prepared with fiber aggregates that do not satisfy either condition a or condition b according to the present invention have significantly increased specific resistance values compared to Preparation Example 1.

In addition, even in the case of Preparation Examples 1 to 5 satisfying condition a and condition b according to the present invention, the conductivity of Preparation Examples 1 to 3 satisfying condition c is superior to that of Preparation Example 4. In addition, in the case of Preparation Example 5, although the thickness of the fabric is thick and the weight of the metal layer loaded on the surface of each mono yarn will significantly increase compared to Preparation Example 1, the degree of improvement in conductivity is compared to the increasing weight of the metal layer. It can be confirmed that this is an insignificant level, and accordingly, it can be confirmed that Preparation Example 1 exhibits excellent conductivity even though it is implemented in a thinner and slimmer form.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention may add elements within the scope of the same spirit. However, other embodiments can be easily proposed by means of changes, deletions, additions, etc., but these will also fall within the scope of the present invention.

15: fiber forming component 22: elution component
100,200,300: conductive fiber assembly 111,112,113,114,311: mono yarn
120: metal coating layer 121a, 121b: first metal
122a, 122b, 122c: second metal particle

Claims (20)

In the coating composition for forming a metal layer provided in the conductive fiber assembly,
The coating composition comprises a first metal precursor and a second metal in a weight ratio of 1: 0.9 to 4.5. According to claim 1,
The second metal is a granular coating composition to improve the ability to form a metal layer inside the fiber assembly and the specific surface area of the metal layer. According to claim 1,
The first metal precursor includes at least one selected from the group consisting of Cu, Ni, Co, Al, and alloys thereof,
The second metal is a coating composition comprising at least one selected from the group consisting of Au, Pt, Pd, Ag, Cu, Ni, and alloys thereof. delete According to claim 1,
The coating composition includes at least one dispersion solvent selected from the group consisting of ethylene glycol, glycol-based ethers and alcohols; and
At least one binder compound selected from the group consisting of polyvinyl alcohol (PVA), acrylic resin, urethane resin, polyester resin, polyvinylpyrronidone (PVP), ethylene vinyl acetate copolymer (EVA) and polyethylene oxide (PEO) A coating composition further comprising: According to claim 2,
Wherein the second metal is a metal powder having a particle size of 10 to 100 nm. According to claim 3,
Wherein the first metal precursor is a copper precursor, and the second metal is copper. (1) processing the fiber aggregate with the coating composition according to any one of claims 1 to 3 and 5 to 7; and
(2) forming a fiber assembly coated with a metal layer containing a first metal and a second metal by firing the coating composition; According to claim 8,
In step (1), the coating composition is treated in an amount of 200 to 1000 parts by weight based on 100 parts by weight of the fiber assembly. According to claim 8,
The method for producing a conductive fiber assembly in which the firing is performed at a temperature of 180 to 220 ° C. for 1 to 30 minutes. A fiber assembly comprising a plurality of monofilaments; and
A metal layer covering at least the outside of the fiber assembly, including a first metal and a second metal,
The fiber assembly includes a fiber bundle including a plurality of monofilaments in warp and weft yarns, and satisfies the following conditions (a) and conditions (b):
(a) 0.02 ≤ D (μm) ≤ 2.5
(b) 40×(D) ^-1.9 ≤ Y ≤ 60×(D) ^-2.0
The D is the mono yarn diameter (㎛), and the Y is the number of mono yarns included per unit area (100 μm ² ) in the vertical cross section of the fabric.
According to claim 11,
The fiber assembly is a yarn containing a plurality of strands of mono yarns, or a conductive fiber assembly that is a fabric of any one of a woven fabric, a knitted fabric, and a non-woven fabric containing a plurality of mono yarns. According to claim 11,
The metal layer is a conductive fiber assembly coated with at least a portion of the surface of the mono yarn not exposed to the outside of the fiber assembly. According to claim 11,
The second metal is provided in granular form to improve the ability to form a metal layer inside the fiber assembly and the specific surface area of the metal layer,
The metal layer is a conductive fiber assembly formed of a granular second metal and a first metal connecting the second metal particles. According to claim 14,
The particle diameter of the second metal is 1/2 to 1/250 of the diameter of the mono yarn provided in the fiber assembly conductive fiber assembly. According to claim 11,
The first metal includes at least one selected from the group consisting of Cu, Ni, Co, Al, and alloys thereof,
The second metal is a conductive fiber assembly comprising at least one selected from the group consisting of Au, Pt, Pd, Ag, Cu, Ni, and alloys thereof. delete According to claim 11,
The fiber assembly further satisfies the following condition (c):
(c)
The D is the mono yarn diameter (㎛), the Y is the number of mono yarns included per unit area (100 µm ² ) in the vertical cross section of the fabric, and T is the thickness (㎛) of the fabric. A gasket comprising the conductive fiber assembly according to claim 11 or claim 18. An electronic device comprising the conductive fiber assembly according to claim 11 or claim 18.

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