JP6293407B2 - Magnetic field shielding material - Google Patents

Description

  The present invention relates to a magnetic field shielding electromagnetic shielding material comprising a metal interwoven fabric. More specifically, the present invention relates to a magnetic field shielding electromagnetic shielding material that is lightweight and excellent in handling properties and moldability.

  In recent years, with rapid development of IT equipment and OA equipment, the influence of electromagnetic waves generated from electronic equipment, cables, motors, and inverters on other electronic equipment and information equipment has become a problem. Among them, the necessity of shielding measures against electromagnetic noise in the low frequency range (radio noise: mainly 100 MHz or less, AM radio: 0.51-1.60 MHz, FM radio: 76-108 MHz) is recognized. It has become to.

As countermeasures against electromagnetic wave noise, both electric field and magnetic field shielding is required, but improvement of magnetic field shielding performance is essential for shielding in a low frequency range, and various attempts have been made.
Conventionally, metal plates such as iron plates and wire meshes using metal wires have been used as electromagnetic shielding materials for low-frequency magnetic field shielding.

  However, these conventional electromagnetic shielding materials have problems such as large weight and thickness, and poor handling and molding processability. In particular, the magnetic field shielding performance in the low frequency range is not always satisfactory.

  For example, Patent Document 1-2 has a high electromagnetic shielding performance constituted by a mixed yarn formed by twisting and / or S twisting a metal wire such as a copper wire on a spinning fiber such as nylon or polyester. A conductive fabric (Patent Document 1), an electromagnetic shielding fabric or an electromagnetic shielding sheet (Patent Document 2) is disclosed. However, the electromagnetic shielding performance of the conductive fabric of Patent Document 1 is about 65 dB to 70 dB at 100 MHz, and does not mention the magnetic field shielding performance in the low frequency range. In addition, the conductive fabric of Patent Document 1 cannot be expected to have a sufficient magnetic field shielding performance in a low frequency range.

  Moreover, since the electromagnetic wave shielding sheet of Patent Document 2 is prepared by sandwiching an electromagnetic wave shielding fabric between resin sheets and bonding and pressing, it is not easy to sufficiently reduce the thickness. In addition, when the casing or the like is formed by insert molding or integral molding with a mold using the electromagnetic wave shielding sheet, molding processability is not always good.

  Patent Document 3 discloses a magnetic shield sheet in which a magnetic layer made of a magnetic powder and a binder is provided on one or both sides of a conductive layer such as an iron-based metal sheet, and an input-compatible display device using the same. However, with this configuration, only a magnetic shield sheet having a certain thickness can be produced.

Patent Document 4 discloses a low-frequency magnetic shielding material in which a metallic fine wire made of permalloy, SUS, or the like is twilled into a cloth-like material.
Patent Document 5 discloses a wire mesh for an electromagnetic shield that is configured by knitting a metal wire or a non-metal wire that has been plated with a metal, and has an uneven surface or a corrugated cross section.

  In Patent Document 6, metal fine fibers or metal-plated fibers are knitted as warp yarns on a base sheet made of woven or non-woven fabric, and metal ultrafine fibers or metal-plated fibers between the knitted warp yarns. Has been disclosed as an electromagnetic shielding material in which warp and weft conduction are ensured.

  However, although shielding materials mainly composed of these metal sheets and metal wires can be expected to have electric field shielding properties, they are insufficient in magnetic field shielding properties, particularly in a low frequency region. In order to impart magnetic field shielding properties only with a metal sheet or metal wire, the flexibility and light weight are impaired, such as increasing the density or increasing the wire diameter, and the cost is high and the cost is inferior. Also, it is not possible to create an extremely thin sheet with a small thickness. Furthermore, in the case of a metal wire-only woven fabric, there is no tension or stiffness in the woven fabric unless there is a certain amount of metal wire diameter and density. Therefore, the shape cannot be maintained, and distortion or misalignment is likely to occur. There were drawbacks such as increased costs for securing.

  Accordingly, it has been desired to develop an electromagnetic shielding material that is lightweight and thin, has excellent handling properties and molding processability, and is excellent in electromagnetic shielding performance, particularly in magnetic field shielding performance in a low frequency range.

JP 2006-124900 A JP2011-179162 JP2005-142551 JP 9-023085 A JP-A-6-302985 JP-A-5-283890

  The problem to be solved by the present invention is to provide an electromagnetic shielding material at a low cost that is light and thin, has good handling properties and moldability, and has excellent electromagnetic shielding performance, particularly magnetic shielding performance in a low frequency range. It is to be.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by applying metal plating to the surface of a metal interwoven fabric formed by interweaving non-metallic fibers and metal wires, and have reached the present invention.

That is, this invention relates to the magnetic field shielding electromagnetic shielding material shown below.
1) A magnetic field shielding electromagnetic shielding material, wherein metal plating is applied to the surface of a metal interwoven fabric obtained by interweaving a non-metallic fiber and a metal wire having a wire diameter of 100 to 300 μm.

2) The magnetic field shielding electromagnetic shielding material according to (1), wherein the nonmetallic fiber is a fiber material selected from the group consisting of synthetic fibers and carbon fibers.
3) At least a part of the warp and / or weft constituting the metal interwoven fabric is a metal wire, and the constituent ratio of the non-metal fiber to the metal wire is 10: 1 to 1: 5 (number ratio). 1) The magnetic field shielding electromagnetic shielding material according to 1).

4) The magnetic field shielding electromagnetic wave according to (1), wherein the metal plating is one layer or two or more layers made of at least one metal or alloy selected from the group consisting of copper, nickel, tin, and silver. Shield material.
5) the fineness of the non-metal fibers is 5~420dtex, (1) the magnetic field shielding electromagnetic wave shielding material according.

6) The magnetic field shielding electromagnetic shielding material according to (1), wherein the metal interwoven fabric has a weave density of 25 to 200 mesh (9.84 to 78.7 pieces / cm).

7) The magnetic field shielding electromagnetic shielding material according to (1), wherein the thickness is 1 mm or less.
8) A laminate product obtained by forming a resin layer on at least one side of the magnetic field shielding electromagnetic shielding material according to any one of (1) to (7).

  ADVANTAGE OF THE INVENTION According to this invention, the electromagnetic shielding material in which the magnetic field shielding performance, especially the magnetic field shielding property in the low frequency range of about 0.1-100 MHz was improved significantly can be provided at low cost. This electromagnetic wave shielding material is a lightweight and extremely thin sheet-like shielding material, and has excellent handling properties and moldability. More specifically, it has the following advantages.

(1) Improvement of magnetic field shielding performance According to the present invention, by applying metal plating to a woven fabric of non-metallic fibers such as synthetic fibers and metal wires, the magnetic field shielding performance in the vicinity of 1 MHz is improved from that of a conventional conductive cloth. Can be improved by 10 dB or more.

(2) Ultra-thinning By using an interwoven fabric of non-metallic fibers such as synthetic fibers and metal wires, it is lighter and thinner than conventional electromagnetic shielding materials consisting only of metal wires or metal-plated non-metal wires. An (ultra-thin) electromagnetic shielding material is obtained.

(3) Molding workability and handling properties According to the present invention, an electromagnetic shielding material with improved handling properties can be provided. That is, the interwoven fabric of non-metallic fibers such as synthetic fibers and metal wires has improved flexibility and texture compared to a fabric only of metal wires, and can retain the shape even when a thin metal wire is used. Therefore, handling properties are not impaired. In particular, the ability to follow distortion during molding is good due to the suppression of distortion and misalignment caused by non-metallic fibers, and wrinkles, tearing, line misalignment, etc. are reduced, so insert molding and integral molding with a mold are easier. For example, it is possible to achieve remarkably superior formability as compared with conventional metal plates and foils while maintaining sufficient magnetic field shielding properties.

(4) Laminated product Further, by laminating the metal union woven fabric of the present invention with a resin, the handling property can be further improved, and the integral molding can be performed more simply. When the metal interwoven fabric is a mesh fabric with a relatively low weave density and a high opening ratio (metal interwoven mesh), if a thermoplastic resin film such as polyethylene or polypropylene is laminated on both sides of the mesh, the resin adheres through the opening. Therefore, the adhesiveness of the obtained laminate product can be improved without using an adhesive or the like. When a laminate product with resin is used, the metal film part (metal interwoven fabric layer) does not appear on the outermost surface, so it is less susceptible to friction and wear, improving wear resistance, and reducing fabric flaking. Even if the product is directly touched, there is an advantage that the metal film portion (metal interwoven fabric layer) is not affected and the handling property is improved.

(5) Improvement of grounding performance According to the present invention, an electromagnetic shielding material having improved grounding performance (certainty of grounding of the ground wire) can be provided. Usually, a ground wire is connected to the electromagnetic shielding material, and a higher shielding performance can be obtained by grounding this, but the shielding material containing organic fibers such as the synthetic fiber of the present invention is a metal wire or a metal sheet. Therefore, the contact area can be increased in a ground wire connecting method such as a clip type, and the connection can be reliably performed.

(6) Cost reduction The metal interwoven fabric of the present invention is formed by interweaving with synthetic fibers, and the metal wire that retains the shape can be replaced with synthetic fibers to significantly reduce the metal dose, thereby reducing costs. This makes it possible to achieve much better economic efficiency than a conventional woven fabric made only of metal wires.

It is a schematic diagram of the metal interwoven fabric used by this invention. It is a graph which shows the relationship between the frequency and magnetic field shielding property in Example 1 and Comparative Examples 1-3 of this invention. It is a graph which shows the relationship between the frequency and magnetic field shielding property in Example 1, 2 of this invention, and the comparative example 1. FIG. It is a graph which shows the relationship between the frequency and magnetic field shielding property in Example 1, 3, 4 and Comparative Example 1 of this invention. It is a graph which shows the relationship between the frequency and magnetic field shielding property in Example 1, 5, 6 of this invention. It is a graph which shows the relationship between the frequency and magnetic field shielding property in Example 1, 7, 8, 9 of this invention.

The magnetic field shielding electromagnetic shielding material of the present invention is made of a metal interwoven fabric formed by interweaving synthetic fibers and metal wires, and the surface thereof is subjected to metal plating.

(1) Metal wire As a material of the metal wire used by this invention, electroconductive metals, such as copper, silver, gold | metal | money, stainless steel, nickel, aluminum, are mentioned. Other examples include alloy wires such as zinc-containing alloy copper and brass, and surface-treated products such as tin-plated copper wires. Of these, a metal wire having copper as a main component is particularly preferable.

The wire diameter of the metal wire is 100 to 300 μm. If the wire diameter of the metal wire is too thick, the weight may be increased and economically inferior, and defects such as troubles may easily occur in cutting and winding operations in the weaving process. On the other hand, when the wire diameter of the metal wire is too thin, there are cases where yarn breakage is likely to occur and the magnetic field shielding performance tends to be insufficient.

(2) Non-metallic fiber The non-metallic fiber used in the present invention is preferably selected from the group consisting of synthetic fibers and carbon fibers.

  Synthetic fibers are fibers composed of plastic, and specifically include nylon fibers, vinylon fibers, polyester fibers, polyolefin fibers, acrylic fibers, vinylidene chloride fibers, polyurethane fibers, aramid fibers, engineering plastic fibers, and the like. . Examples of the engineering plastic fiber include those made of liquid crystal polymer (LCP), polyphenylene sulfide (PPS) and the like as raw materials.

  Among these, nylon fibers or polyester fibers are preferable. Nylon fibers include nylon 6, nylon 66, nylon 12, nylon 46, and the like. Examples of the polyester fiber include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). Among these, polyester fibers are particularly preferable in terms of ease of weaving, versatility, and stability in plating.

  The fineness of the nonmetallic fiber is not particularly limited, but is preferably 5 to 420 dtex. If the fineness of the non-metallic fiber is too high (too thick), the texture after metal plating may become hard and the flexibility may be impaired. If it is too low (too thin), thread breakage tends to occur. There is a case where wrinkles are easily formed in post-processing, and the density of the synthetic fiber to be used needs to be increased, and metal plating is excessively attached, resulting in inferior economically.

  The non-metallic fiber may be a monofilament yarn or a multifilament yarn. Further, the cross-sectional shape of the fiber may be a circular shape, or may be a so-called irregular cross-sectional yarn other than a circular shape.

  The fineness is a value representing the thickness of the fiber defined by JIS L 0101-1978 (Tex method), and is a value measured based on the JIS L 1013-1999 B method.

(3) Metal interwoven fabric The metal interwoven fabric used for the electromagnetic wave shielding material of the present invention is obtained by interweaving the above-described nonmetallic fibers and metal wires. Specifically, it is formed by weaving metal wires and non-metal fibers alternately with a loom. By interweaving non-metallic fibers and metal wires in this way, the degree of freedom for changing the amount, wire diameter, and type of metal wires and / or non-metallic fibers is increased.

  In the metal interwoven fabric of the present invention, at least a part of the warp and / or the weft constituting the fabric may be a metal wire. For example, metal wires may be inserted at intervals of at least one of the warp and the weft. In that case, the insertion density of the metal wire is not particularly limited, but for both warp and weft, for example, “one metal wire for 10 nonmetal fibers” to “metal wire 5 for one nonmetal fiber” It is preferable to insert at a ratio of “book”.

The insertion density of the metal wire may be constant throughout the fabric, or the insertion density of the metal wire may be partially changed. The metal lines may be inserted at regular intervals or at irregular intervals. In consideration of weaving properties, it is preferable that the entire woven fabric has a constant metal linear density and the metal wires are inserted at equal intervals. If the insertion density of the metal wires is within this range, sufficient magnetic field shielding performance can be obtained without impairing flexibility.
In addition, either one of the warp and the weft can be formed only with a metal wire and interwoven.

  In any embodiment, the composition ratio of the non-metallic fiber and the metal wire to the entire metal interwoven fabric is preferably 10: 1 to 1: 5 (number ratio), more preferably 6: 1 to 1: 1. desirable. If the composition ratio of the metal wire is too small, sufficient magnetic field shielding performance may not be obtained, and if it is too large, flexibility, handling properties and molding processability may be inferior.

  A schematic diagram of an example of a metal interwoven fabric used in the present invention is shown in FIG. In FIG. 1, white lines indicate non-metallic fibers, and black lines indicate metal lines, and metal lines are inserted into the non-metallic fibers at equal intervals. FIG. 1 schematically shows an example of a configuration (a weaving state) in a woven fabric of non-metallic fibers and metal wires, and the thickness of the non-metallic fibers and the metal wires is not considered. Moreover, this structure shows an example of the metal unwoven fabric in this invention, and the structure of the metal unwoven fabric of this invention is not limited to this.

  The woven density of the metal interwoven fabric is not particularly limited, but it is desirable to have a woven density that can maintain the shape. Specifically, it is desirable to have a woven density of 25-200 mesh (9.84-78.7 / cm), more preferably 50-150 mesh (19.7-59.1 / cm). If the woven density is within this range, the fabric is sufficiently provided with elasticity and stiffness, and can exhibit excellent flexibility while maintaining its shape. A metal unwoven fabric having a low weave density and a high aperture ratio may be referred to as a “metal union mesh”.

  The method for producing the metal interwoven fabric of the present invention is not particularly limited, and the metal interwoven fabric can be woven with a loom in the same manner as a normal fabric. As the loom, any conventionally known loom may be used. Examples of usable looms include shuttle looms, rapier looms, air jet looms, needle looms, water jet looms, gripper looms, and jacquard looms.

(4) Metal plating The electromagnetic wave shielding material of the present invention is obtained by performing metal plating on the surface of the above-described metal interwoven fabric. Examples of the metal for plating include at least one metal selected from the group consisting of copper, nickel, tin, and silver, or an alloy thereof (for example, an alloy of copper and tin), and particularly preferably copper and nickel. is there. By this metal plating, surface conductivity is imparted to the entire metal interwoven fabric, and electromagnetic wave shielding performance, particularly magnetic field shielding performance in a low frequency region can be improved while maintaining flexibility and lightness.

As a specific metal plating method, the metal layer is preferably formed by electroless plating (immersion method) in consideration of the uniformity, conductivity, and electromagnetic wave shielding of the metal layer. After pre-treatment such as application of catalyst and activation performed in normal electroless plating treatment, the metal is subjected to electroless plating treatment with a desired metal such as copper, nickel, tin, silver, or alloys thereof. A layer is formed. A metal layer of the same kind may be laminated by electroplating on the metal layer formed by electroless plating. Also, a state in which metal layers made of two or more different metals such as copper + nickel, copper + silver, nickel + cobalt, nickel + copper + nickel are laminated by a combination of electroless plating and electroplating May be formed.
A particularly preferred metal plating method in the present invention is a method of laminating two metal plating layers of copper and nickel by performing electro nickel plating treatment following electroless copper plating treatment.

  In the present invention, it is preferable to form a metal layer on the entire front and back surfaces including the inner surface of the electromagnetic wave shielding material by metal plating. High magnetic field shielding properties can be obtained by forming a metal layer on the entire surface of the electromagnetic shielding material.

  In the present invention, the thickness of the electromagnetic shielding material having high magnetic field shielding performance in the low frequency range is increased by applying metal plating to the surface of the metallic unwoven fabric formed by interweaving the synthetic fiber and the metal wire. It can be formed as a lightweight and extremely thin sheet. Moreover, this thing is excellent in a softness | flexibility, and has high handling property and moldability.

(5) Electromagnetic wave shielding material The thickness of the electromagnetic wave shielding material of the present invention is not particularly limited, but it is preferably 1 mm or less, more preferably 0.5 mm or less, and particularly preferably 0.2 mm or less. Can do. Conventional electromagnetic shielding materials can only produce sheets with a certain thickness due to the use of magnetic materials, etc., but according to the present invention, it is possible to create a lightweight and extremely thin electromagnetic shielding sheet It becomes.

  By laminating the surface of the electromagnetic wave shielding material of the present invention with a resin, the electromagnetic shielding material can be made less susceptible to the effects of friction and wear, and the handling properties can be improved. The laminate layer can be provided on one side or both sides of the electromagnetic shielding material, but is preferably provided on both sides. Further, the laminate layer can be not only one layer but also two or more layers (for example, 2 to 3 layers).

  Examples of the resin to be laminated include polyolefin resins such as polypropylene and polyethylene, styrene resins such as polystyrene and ABS resin, and thermoplastic resins such as engineering plastics such as polyphenylene sulfide and liquid crystal polymer.

  Further, when the metal union woven fabric is a metal union mesh with a high opening ratio, since the resin adheres through the openings when the resin is laminated on both sides of the mesh, an adhesive or the like is used for the adhesion of the obtained laminate product. It can be improved without. The thickness of the laminate is preferably 1 mm or less, more preferably 0.5 mm or less, and particularly preferably 0.2 mm or less. According to the present invention, a lightweight and extremely thin electromagnetic shielding sheet (laminate) is produced. Is possible.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
In addition, each measured value in the following Examples was calculated | required with the following method.

1) Magnetic field shielding properties Magnetic field shielding properties (electromagnetic wave shielding performance, unit: dB) were measured using the KEC method (KEC: abbreviation of “Kansai Electronics Industry Promotion Center”). More specifically, the magnetic field strength (the magnetic field strength in the space when there is no shield material) between the probe with the signal transmitting antenna that transmits the pseudo noise source and the probe with the receiving antenna, and both probes The magnetic field strength when a sample (shielding material) was inserted between them (the magnetic field strength of the space when there was a shielding material) was measured. Next, the difference in magnetic field strength depending on the presence or absence of the sample was determined, and the magnetic field shielding property (= shielding effect; SE) was calculated based on the following formula (1). The probes include an electric field shielding property measuring probe and a magnetic field shielding property measuring probe. In this embodiment, a magnetic field shielding property measuring probe is used.

[Equation 1]
SE (shield effect) = 20 log ₁₀ (Mo / Mx)
Mo: Magnetic field strength in the space when there is no shield material Mx: Magnetic field strength in the space when there is a shield material

2) Fineness The fineness was measured based on JIS L 1013-1999 B method. A value obtained by taking 20 samples exactly 90 cm in length with the initial load, measuring the absolute dry mass, calculating the correct fineness (tex) by the following formula (2), and taking the average value of the two times It is.
[Equation 2]
Positive fineness = 1000 × (absolute dry mass of sample) / (length of sample) × (100 + R ₀ ) / 100
* Here, R ₀ represents the official moisture content (%) specified in 3.1 of JIS L 0105.

<Example 1>
Synthetic fibers (PET fibers with a fiber diameter of 40 μm and fineness of 16.5 dtex) and metal wires (copper wires with a wire diameter of 0.1 mm) are interwoven with a composition ratio of synthetic fibers: metal wires = 6: 1 (number ratio). Thus, a metal interwoven fabric was obtained in which metal wires were inserted into both the warp and the weft at equal intervals (2.0 mm pitch). The woven density of this product was 70 mesh (27.55 pieces / cm).

The obtained metal unwoven fabric was immersed in a treatment aqueous solution at 40 ° C. containing 0.3 g / L of palladium chloride, 30 g / L of stannous chloride and 300 ml / L of 36% hydrochloric acid, and then washed with water. Subsequently, the metal unwoven fabric was immersed in borohydrofluoric acid having an acid concentration of 0.1 N at 30 ° C. for 5 minutes, and then washed with water. Next, it was immersed in an electroless copper plating solution consisting of copper sulfate 7.5 g / L, 37% formalin 30 ml / L, and Rochelle salt 85 g / L at 30 ° C. for 5 minutes and then washed with water. Subsequently, nickel is laminated by dipping in an electric nickel plating solution of nickel sulfamate 300 g / L, boric acid 30 g / L, nickel chloride 15 g / L, pH 3.7 at 35 ° C. for 10 minutes at a current density of 5 A / dm ^2. Thereafter, it was washed with water and dried to obtain an electromagnetic wave shielding material having two metal plating layers of a copper plating layer and a nickel plating layer, and having an overall thickness of 0.2 mm. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in Table 1 and FIG.

<Comparative Example 1>
A metal wire made of SUS304 steel having a diameter of 0.22 mm was used to weave a plain weave into a 40 mesh (15.7 pieces / cm) cloth to obtain an electromagnetic wave shielding material. The thickness of this thing was 0.5 mm. About the obtained electromagnetic shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured like Example 1. FIG. The results are shown in Table 1 and FIG.

<Comparative example 2>
Synthetic fibers (PET fibers having a fiber diameter of 27 μm and a fineness of 7.5 dtex) were woven to obtain a PET fiber fabric. The woven density of this product was 138 mesh (54.3 pieces / cm). The obtained PET fiber fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.05 mm.
About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in Table 1 and FIG.

<Comparative Example 3>
An electromagnetic wave shielding material was obtained in the same manner as in Example 1 except that the metal plating treatment was not performed. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in Table 1 and FIG.

  As can be seen from FIG. 2 and Table 1, the electromagnetic wave shielding material of the present invention is obtained by applying metal plating to a conductive fabric made of only metal wires, a metal interwoven fabric that only includes metal wires, or a fabric made of synthetic fibers. Compared with conductive fabrics only, magnetic field shielding performance in the low frequency range is greatly improved.

<Example 2>
Synthetic fibers (PET fibers with a fiber diameter of 40 μm and fineness of 16.5 dtex) and metal wires (copper wires with a wire diameter of 0.1 mm) are used in a composition ratio of synthetic fibers: metal wires = 6: 1, and metal interweaving A woven fabric was created. The warp of this product is configured by inserting a metal wire and a synthetic fiber at equal intervals (2.0 mm pitch), and the weft is configured of only a synthetic fiber. The woven density of this product was 70 mesh (27.55 pieces / cm).

  The obtained metal unwoven fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.2 mm. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in FIG. 3 together with the results of Example 1 and Comparative Example 1.

<Example 3>
Synthetic fiber (PET fiber with 40 μm fiber and fineness of 16.5 dtex) and metal wire (copper wire with a wire diameter of 0.1 mm) are interwoven in a composition ratio of synthetic fiber: metal wire = 2: 1. A metal interwoven fabric was obtained in which both the warp and the weft were inserted at equal intervals (a ratio of one metal wire to two synthetic fibers). The woven density of this product was 70 mesh (27.55 pieces / cm).

  The obtained metal unwoven fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.2 mm. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in FIG. 4 together with the results of Example 1 and Comparative Example 1.

<Example 4>
Synthetic fibers (PET fibers having a fiber diameter of 40 μm and a fineness of 16.5 dtex) and metal wires (copper wires having a wire diameter of 0.1 mm) are interwoven with a composition ratio of synthetic fibers: metal wires = 4: 1 to obtain metal wires. Was obtained by inserting metal warp and weft at equal intervals (a ratio of one metal wire to four synthetic fibers). The woven density of this product was 70 mesh (27.55 pieces / cm).

  The obtained metal unwoven fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.2 mm. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in FIG. 4 together with the results of Example 1 and Comparative Example 1.

  As can be seen from FIG. 4, in Example 3, the magnetic field shielding property is improved by about 13 dB at 1 MHz and about 5 dB at 10 MHz, compared to the fabric made of only metal (Comparative Example 1). In Example 4, the magnetic field shielding property is improved by about 10 dB at 1 MHz and 3 dB at 10 MHz. As described above, the electromagnetic shielding material of the present invention has greatly improved magnetic field shielding properties in the low frequency range.

<Example 5>
Synthetic fiber (PET fiber having a fiber diameter of 40 μm and fineness of 16.5 dtex) and a metal wire (copper wire having a wire diameter of 0.2 mm) are interwoven with a composition ratio of synthetic fiber: metal wire = 6: 1 to obtain a metal wire. A metal union woven fabric was inserted into both the warp and the weft at equal intervals (a ratio of one metal wire to six synthetic fibers). The woven density of this product was 70 mesh (27.55 pieces / cm).
The obtained metal interwoven fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.4 mm. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in FIG.

<Example 6 (comparative example) >
Synthetic fiber (PET fiber having a fiber diameter of 40 μm and fineness of 16.5 dtex) and a metal wire (copper wire having a wire diameter of 0.05 mm) are interwoven with a composition ratio of synthetic fiber: metal wire = 6: 1 to obtain a metal wire. A metal union woven fabric was inserted into both the warp and the weft at equal intervals (a ratio of one metal wire to six synthetic fibers). The woven density of this product was 70 mesh (27.55 pieces / cm).
The obtained metal unwoven fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.1 mm. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in FIG.

In Example 5, compared to Example 6 (Comparative Example) , the shielding performance is improved by about 8 dB at 1 MHz and 3 dB at 10 MHz, and the magnetic field shielding performance in the low frequency range is greatly improved. I understand. By increasing the wire diameter, it is possible to improve the magnetic field shielding property in a low frequency region even with a woven fabric having the same weave density.

<Example 7>
Synthetic fibers (PET fibers having a fiber diameter of 40 μm and fineness of 16.5 dtex) and metal wires (tin-plated copper wires having a wire diameter of 0.1 mm) are interwoven in a composition ratio of synthetic fibers: metal wires = 6: 1. A metal interwoven fabric was obtained in which metal wires were inserted into both warp and weft at equal intervals (a ratio of one metal wire to six synthetic fibers). The woven density of this product was 70 mesh (27.55 pieces / cm).
The obtained metal unwoven fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.2 mm. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in FIG.

<Example 8>
Synthetic fibers (PET fibers having a fiber diameter of 40 μm and fineness of 16.5 dtex) and metal wires (zinc-containing alloy copper wires having a wire diameter of 0.1 mm) are interwoven in a composition ratio of synthetic fibers: metal wires = 6: 1. A metal interwoven fabric was obtained in which metal wires were inserted into both the warp and the weft at equal intervals (a ratio of one metal wire to six synthetic fibers). The woven density of this product was 70 mesh (27.55 pieces / cm).
The obtained metal unwoven fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.2 mm. About the obtained electromagnetic wave shielding material, the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz was measured. The results are shown in FIG.

<Example 9>
Synthetic fiber (PET fiber having a fiber diameter of 40 μm and fineness of 16.5 dtex) and a metal wire (brass wire having a wire diameter of 0.1 mm) are interwoven in a composition ratio of synthetic fiber: metal wire = 6: 1 to obtain a metal wire. A metal union woven fabric was inserted into both the warp and the weft at equal intervals (a ratio of one metal wire to six synthetic fibers). The woven density of this product was 70 mesh (27.55 pieces / cm).
The obtained metal unwoven fabric was subjected to metal plating (copper-nickel) treatment in the same manner as in Example 1 to obtain an electromagnetic wave shielding material having a thickness of 0.2 mm. About the obtained electromagnetic shielding material, the result of having measured the magnetic field shielding property (unit; dB) in the low frequency range of 0.1 MHz-100 MHz is shown in FIG.

According to the present invention, it is possible to obtain an electromagnetic shielding material having significantly improved magnetic field shielding performance, particularly magnetic field shielding performance in a low frequency range of about 0.1 to 100 MHz, at a low cost. This electromagnetic shielding material is a lightweight and extremely thin sheet-shaped shielding material that has excellent handling and molding processability, and electromagnetic waves such as noise generated from drive systems such as inverters, motors, and batteries, and ECUs. It can be used suitably for a shield countermeasure member.

Claims (8)

A magnetic field shielding electromagnetic shielding material, wherein metal plating is applied to the surface of a metal interwoven fabric formed by interweaving a non-metallic fiber and a metal wire having a wire diameter of 100 to 300 μm.   The magnetic field shielding electromagnetic shielding material according to claim 1, wherein the nonmetallic fiber is a fiber material selected from the group consisting of synthetic fibers and carbon fibers.   The warp and weft constituting the metal interwoven fabric are at least part of metal wires, and the composition ratio of the non-metal fibers to the metal wires is 10: 1 to 1: 5 (number ratio). Magnetic field shielding material.   2. The magnetic field shielding electromagnetic shielding material according to claim 1, wherein the metal plating is one layer or two or more layers made of at least one metal or alloy selected from the group consisting of copper, nickel, tin, and silver. . The fineness of the non-metal fibers is 5～420Dtex, claim 1 field shielding electromagnetic wave shielding material according.   The magnetic field shielding electromagnetic shielding material according to claim 1, wherein the metal interwoven fabric has a weave density of 25 to 200 mesh (9.84 to 78.7 pieces / cm).   2. The magnetic field shielding electromagnetic shielding material according to claim 1, wherein the thickness is 1 mm or less.   A laminate product comprising a resin layer formed on at least one side of the magnetic field shielding electromagnetic shielding material according to claim 1.

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