Electro-magnetic shielding property cover material and electro-magnetic shielding cover

Abstract

To provide an electro-magnetic shielding property cover material having not only a good electro-magnetic shielding property, but also durability, a product holding shape property, a sewing operability, and a sewing product quality.SOLUTION: An electro-magnetic shielding property cover material comprises: first cloth 2; a metal skin film 3 that is formed onto at least both surfaces of the first cloth 2; and a support layer 4 that is laminated to a metal skin film 3a on one side surface of the metal skin film 3. It is conformed to ASTM D 4833, when a bore hole needle (a whole length (a tip end part + a base end part) is 40 mm, a circular corn of which a tip end part is 25 mm in a length*2 mm in a bottom surface diameter, and a circular column of which a base end part is 15 mm in a length*2 mm in a cross sectional diameter) is inserted from the support layer 4, an initial insertion resistance value R1 as an insertion resistance value until the tip end part is reached to a metal skin film 3b on the other surface side is 3 tot 9N, and a rear insertion resistance value R2 as an insertion resistance value until the base end part is reached to a front surface of the other metal skin film 3b is 7 to 13N.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electromagnetic wave shielding cover material and an electromagnetic wave shielding cover.

Background Art

[0002] Conventionally, RFID (Radio Frequency Identification) has been used in logistics management in warehouses and the like. RFID is a general term for technologies that read and write information on an IC tag in a non-contact manner using radio waves. Specifically, for example, it is configured to transmit and receive radio waves between an RFID reader and an IC tag via an antenna.

[0003] In this type of RFID, communication failures may occur between the RFID reader and the IC tag due to radio wave interference between multiple antennas or radio wave reflection from walls, and there is a risk that the RFID reader may misrecognize the information on the IC tag.

[0004] Therefore, for example, as a technology for suppressing misrecognition of an IC tag by RFID, a partition plate for preventing misrecognition of an IC tag in which conductive fibers coated with metal and non-conductive fibers are bonded via a binder has been proposed (see Patent Document 1). Further, as a technology for suppressing radio wave interference and radio wave reflection, an electromagnetic wave shielding material in which a metal plating film is formed on at least one side of a sheet made of synthetic fiber has been proposed (see Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in a shielding material using conductive fibers coated with a metal as in Patent Document 1 and non-conductive fibers, there is a risk that the electromagnetic wave shielding property may be insufficient. Further, when forming a metal film on a sheet made of synthetic fibers as in Patent Document 2, there is a risk of inferior durability such as bending durability and product shape retention (product shape retention).

[0007] In addition, when storing a plurality of products with IC tags in a storage or the like, it is necessary to suppress misrecognition of information of all the IC tags. For this purpose, it is necessary to suppress misrecognition in a relatively large area. Along with this, it is necessary to increase the size of the electromagnetic wave shielding cover material. For this purpose, it is necessary to sew a plurality of electromagnetic wave shielding cover materials. Therefore, the electromagnetic wave shielding cover material is also required to be easy to sew (excellent in sewing workability) and excellent in the quality of the product after sewing (sewing product quality). Further, durability is also required.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide an electromagnetic wave shielding cover material excellent not only in electromagnetic wave shielding property but also in durability, product shape retention, sewing workability, and sewing product quality, and an electromagnetic wave shielding cover formed by sewing this.

Means for Solving the Problems

[0009] The characteristic configuration of the electromagnetic wave shielding cover material of the present invention for solving the above problems is a first fabric, metal films formed on at least both surfaces of the first fabric, a support layer laminated on the metal film on one surface side of the metal films and, When penetrating a perforating needle (total length (tip + base end): 40 mm, tip: cone with a length of 25 mm and a bottom diameter of 2 mm, base end: cylinder with a length of 15 mm and a cross-sectional diameter of 2 mm) from the support layer side in accordance with ASTM D 4833, the initial penetration resistance value R1, which is the penetration resistance value until the tip reaches the surface of the metal film on the other surface side, is 3 to 9 N, The late penetration resistance value R2, which is the penetration resistance value until the base end portion reaches the surface of the metal film on the other surface side, is 7 to 13 N.

[0010] According to the electromagnetic shielding cover material of this configuration, since metal films are formed on at least both surfaces of the first fabric, the durability is enhanced. Since the support layer is laminated on the metal film on one surface side of the metal films, the product shape retention property is enhanced, and it becomes possible to appropriately set the initial penetration resistance value R1 and the late penetration resistance value R2. By setting the initial penetration resistance value R1 and the late penetration resistance value R2 within the respective appropriate ranges, the sewing workability and the quality of the sewn product can be enhanced. Therefore, the electromagnetic shielding cover material is excellent not only in electromagnetic shielding property but also in durability, product shape retention property, sewing workability, and the quality of the sewn product.

[0011] In the electromagnetic shielding cover material according to the present invention, The basis weight is preferably 200 to 800 g / m 2 is preferable.

[0012] According to the electromagnetic shielding cover material of this configuration, by setting the basis weight of the electromagnetic shielding cover material within the above range, while enhancing the strength of the electromagnetic shielding cover material, the initial penetration resistance value R1 and the late penetration resistance value R2 can be set in more appropriate ranges.

[0013] In the electromagnetic shielding cover material according to the present invention, The support layer is preferably a resin film or a second fabric.

[0014] According to the electromagnetic shielding cover material of this configuration, by selecting a resin film as the support layer, in particular, the durability, product shape retention property, sewing workability, and the quality of the sewn product can be further enhanced. Also, by selecting a second fabric as the support layer, in particular, the sewing workability and the quality of the sewn product can be further enhanced.

[0015] In the electromagnetic wave shielding cover material according to the present invention, the amount of metal in the metal film is preferably 10 to 40 g / m 2 .

[0016] According to the electromagnetic wave shielding cover material of this configuration, by setting the amount of metal in the metal film within the above range, in particular, the electromagnetic wave shielding property can be further enhanced.

[0017] In the electromagnetic wave shielding cover material according to the present invention, the metal film is preferably a multi-layered material composed of a copper film and a nickel film.

[0018] According to the electromagnetic wave shielding cover material of this configuration, by adopting the above multi-layered material as the metal film, the electromagnetic wave shielding property can be further enhanced.

[0019] In the electromagnetic wave shielding cover material according to the present invention, the thickness is preferably 0.2 to 1 mm.

[0020] According to the electromagnetic wave shielding cover material of this configuration, by setting the thickness of the electromagnetic wave shielding cover material within the above appropriate range, the electromagnetic wave shielding property, durability, product shape retention, sewing workability, and sewing product quality can be further enhanced.

[0021] In the electromagnetic wave shielding cover material according to the present invention, the support layer is preferably composed of polyvinyl chloride or polyester.

[0022] According to the electromagnetic wave shielding cover material of this configuration, by adopting the above appropriate type as the constituent material of the support layer, in particular, the durability, product shape retention, sewing workability, and sewing product quality can be further enhanced.

[0023] In the electromagnetic wave shielding cover material according to the present invention, it is preferably used for preventing misreading in radio frequency identification (RFID).

[0024] According to the electromagnetic wave shielding cover material of this configuration, by being used for preventing misreading in radio frequency identification (RFID), it can be suitably used for logistics management.

[0025] The characteristic configuration of the electromagnetic wave shielding cover of the present invention for solving the above problems is that the electromagnetic wave shielding cover material is sewn.

[0026] According to the electromagnetic wave shielding cover of this configuration, as described above, since an electromagnetic wave shielding cover material excellent in electromagnetic wave shielding property, durability, product shape retention property, sewing workability, and sewing product quality is sewn, while reducing sewing defects, the electromagnetic wave shielding property, durability, product shape retention property, sewing workability, and sewing product quality that the electromagnetic wave shielding cover material originally has can be exhibited.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0028] Hereinafter, embodiments of the electromagnetic shielding cover material and the electromagnetic shielding cover of the present invention will be described. However, the present invention is not intended to be limited to the configurations described below and the examples described later.

[0029] [Electromagnetic Shielding Cover Material] FIG. 1 is a schematic cross-sectional view of an electromagnetic shielding cover material 1 according to an embodiment of the present invention. In FIG. 1, each layer constituting the electromagnetic shielding cover material 1 does not accurately reflect the thickness relationship of each actual layer. The electromagnetic shielding cover material 1 of the present embodiment includes a first fabric 2, metal films 3 (3a, 3b) formed on at least both surfaces of the first fabric 2, and a support layer 4 laminated on the metal film 3a on one surface side (that is, one surface side of the first fabric 2) of the metal films 3.

[0030] (First Fabric) The first fabric 2 has metal films formed on at least both of its surfaces. Specifically, for the first fabric 2, not only are metal films formed on both of its surfaces, but in addition, metal films may be formed on a part or all of the end faces (side parts). The first fabric 2 is not particularly limited, and examples include woven fabrics such as plain weave, twill weave, and damask weave, knitted fabrics such as jersey knit, rib knit, pearl knit, and smooth knit, non-woven fabrics, etc. As the woven fabric, it can also be woven as a multi-layer fabric using connecting threads that connect between the surface fabric and the back fabric. As the knitted fabric, it can also be knitted as a multi-layer knitted fabric using connecting threads that connect between the surface knitted fabric and the back knitted fabric. The material of the thread constituting the fabric is not particularly limited, and examples include conventionally known fibers such as natural fibers, regenerated fibers, semi-synthetic fibers, and synthetic fibers. Among them, synthetic fibers are preferable from the viewpoints of heat resistance and light resistance. Examples of synthetic fibers include polyester fibers such as polyethylene terephthalate, polyvinyl fibers such as polyvinyl chloride, and polyolefin fibers such as polyethylene. The synthetic fibers may be a blend of two or more kinds of fibers.

[0031] Examples of the constituent raw materials of the thread constituting the first fabric 2 include polyester fibers, polyamide fibers, polyolefin fibers, polyurethane fibers, etc. Among these, polyester fibers are preferable. These fibers may be used alone or in a blend or mixed spinning of two or more kinds.

[0032] The yarn fineness is preferably 22 to 167 dtex, more preferably 33 to 56 dtex. By setting the yarn fineness within the above range, while increasing the strength of the first fabric 2, the penetration resistance values R1 and R2 described later can be set within an appropriate range.

[0033] The yarn density is preferably 100 to 200 threads / 2.54 cm, more preferably 120 to 160 threads / 2.54 cm. By setting the yarn density within the above range, while increasing the strength of the first fabric 2, the penetration resistance values R1 and R2 described later can be set within an appropriate range.

[0034] The cover factor of the first fabric 2 is preferably 1300 to 2600. The cover factor is measured by the measuring method described later. By setting the cover factor within the above range, while increasing the strength of the first fabric 2, the penetration resistance values R1 and R2 described later can be set within an appropriate range.

[0035] The basis weight of the first fabric 2 can be appropriately set so that the basis weight of the electromagnetic shielding cover material 1 described later is appropriate.

[0036] (Metal film) The metal film 3 is formed on at least both surfaces of the first fabric 2. Specifically, the metal film 3 is of course formed on both surfaces of the first fabric 2, and in addition to that, the metal film 3 may be formed on a part or all of the end faces (side parts). When the metal film 3 is formed on both surfaces and all of the end faces of the first fabric 2, it will cover the entire first fabric 2. Examples of the metal constituting the metal film 3 include gold, silver, copper, platinum, nickel, zinc, tin, etc. The metal may be used alone or in combination of two or more. When using two or more metals, the metal film 3 may be a multilayer, or may be a single-layer metal film 3 made of an alloy containing a plurality of metals. Among these, the metal is preferably copper or nickel, and preferably has a multilayer structure in which a nickel film is laminated on a copper film. By adopting the above multilayer structure as the metal film 3, the electromagnetic shielding property can be further enhanced.

[0037] The metal amount in the metal film 3 is preferably 10 to 40 g / m 2 By setting the metal amount in the metal film 3 within the above range, in particular, the electromagnetic shielding property can be further enhanced.

[0038] The thickness of the metal film 3 can be appropriately set so that the thickness of the laminate (hereinafter, also referred to as "metal film-forming fabric") formed by the metal film 3 on the first fabric 2 falls within an appropriate range described later.

[0039] As methods for forming the metal film 3, methods such as vapor deposition, sputtering, electroplating, electroless plating, etc. can be mentioned. Among these, electroless plating and / or electroplating are preferable in that a more uniform metal film 3 can be formed on at least both surfaces of the first fabric 2. According to such electroless plating and / or electroplating, since the entire first fabric 2 is immersed in the plating solution, in addition to both surfaces of the first fabric 2, a metal film 3 can also be formed as a metal plating film on all of the end faces, and the metal film 3 will cover the entire first fabric 2. Also, it is preferable to form the metal film 3 into a multilayer structure by first performing electroless plating on the first fabric 2 and then performing electroplating, and it is more preferable to perform electroless copper plating and then electro nickel plating.

[0040] When performing electroless copper plating and electro nickel plating, first, for the first fabric 2, an electroless plating catalyst is applied with a colloidal solution containing lead chloride (PbCl2) and tin chloride (SnCl2), and then electroless copper plating and then electro nickel plating can be continuously performed. In electroless copper plating, a plating solution containing copper chloride (CuCl2), formaldehyde, and sodium hydroxide can be used. In electro nickel plating, a plating solution containing nickel sulfate hexahydrate (NiSO4·6H2O) and sodium citrate can be used.

[0041] (Properties of the fabric for forming the metal film) The thickness of the fabric for forming the metal film can be appropriately set so that the total with the thickness of the support layer 4 is preferably 0.2 to 1 mm, more preferably 0.3 to 0.5 mm as described later. Among these, the thickness of the fabric for forming the metal film is preferably 0.1 to 0.5 mm, and more preferably 0.2 to 0.4 mm. By setting the thickness of the fabric for forming the metal film within the above range, electromagnetic wave shielding properties, durability, product shape retention, sewing workability, and sewing product quality can be further enhanced.

[0042] (Support layer) The support layer 4 is not particularly limited, but for example, a resin film or a second fabric is preferable. By selecting a resin film as the support layer 4, in particular, durability, product shape retention, sewing workability, and the quality of sewn products can be further enhanced. Also, by selecting a second fabric as the support layer 4, in particular, sewing workability and the quality of sewn products can be further enhanced.

[0043] Examples of the resin film include polyester films such as polyethylene terephthalate, polyvinyl films such as polyvinyl chloride, and polyolefin films such as polyethylene. The resin film may be a laminated film combining two or more films or a mixed resin film.

[0044] As the second fabric, the same fabric as the first fabric 2 can be used.

[0045] By adopting the above-mentioned appropriate components and materials for the support layer 4, in particular, durability, product shape retention, sewing workability, and the quality of sewn products can be further enhanced.

[0046] The thickness of the support layer 4 is preferably 0.1 to 0.5 mm, and more preferably 0.1 to 0.4 mm. By setting the thickness of the support layer 4 within the above-mentioned appropriate range, in particular, durability, product shape retention, sewing workability, and the quality of sewn products can be further enhanced.

[0047] (Lamination method of metal film-forming fabric and support layer) The lamination method of the metal film-forming fabric and the support layer 4 is not particularly limited. When the support layer 4 is a resin film, the metal film 3a on one surface side of the metal film-forming fabric and the support layer 4 are overlapped and adhered using a conventionally known lamination technique such as dry lamination. When the support layer 4 is a second fabric, the metal film 3a on one surface side of the metal film-forming fabric and the support layer 4 are overlapped and sewn using a conventionally known sewing technique.

[0048] <Characteristics of electromagnetic wave shielding cover material> (Thickness) The thickness of the electromagnetic shielding cover material 1 is represented by the sum of the thickness of the metal film-forming fabric and the thickness of the support layer 4. Such a sum is preferably 0.2 to 1 mm, and more preferably 0.3 to 0.5 mm. By setting the above sum within the above range, the electromagnetic shielding property, durability, product shape retention, sewing workability, and sewing product quality can be further enhanced.

[0049] (Areal density) The areal density of the electromagnetic shielding cover material 1 is preferably 200 to 800 g / m 2 . By setting the areal density of the electromagnetic shielding cover material 1 within the above range, while increasing the strength of the electromagnetic shielding cover material 1, the penetration resistance values R1 and R2 described later can be set within an appropriate range.

[0050] (Penetration resistance value) The electromagnetic shielding cover material 1 can be measured by a penetration resistance test conforming to ASTM D 4833. However, in the present invention, instead of the metal rod with a diameter of 8 mm specified in ASTM D 4833, a perforating needle made of metal (total length 40 mm) consisting of a tip portion and a base end portion is used. The tip portion (length 25 mm) is a conical portion with a bottom diameter of 2 mm, and the base end portion (length 15 mm) is a cylindrical portion with a cross-sectional diameter of 2 mm. The perforating needle can be configured as a portion that protrudes from the mounting portion to the device in a penetration jig attached to the penetration test device with the above dimensions and pierces the electromagnetic shielding cover material 1. When this perforating needle is penetrated into the electromagnetic shielding cover material 1 from the support layer 4 side, the penetration resistance value until the tip portion reaches the surface of the metal film 3b on the other surface side (that is, the other surface side of the first fabric 2) is defined as the initial penetration resistance value R1, and the penetration resistance value until the base end portion reaches the surface of the metal film 3b on the other surface side is defined as the later penetration resistance value R2. The initial penetration resistance value R1 and the later penetration resistance value R2 are measured by the measurement method described later. The electromagnetic shielding cover material 1 of the present invention is set such that the initial penetration resistance value R1 is 3 to 9 N and the later penetration resistance value R2 is 7 to 13 N. By setting the initial penetration resistance value R1 and the later penetration resistance value R2 above the respective lower limits, the sewing workability and the quality of the sewn product can be improved. Also, by setting the initial penetration resistance value R1 and the later penetration resistance value R2 below the respective upper limits, the sewing workability and the quality of the sewn product can be improved. If the initial penetration resistance value R1 and the later penetration resistance value R2 are less than the respective lower limits, the sewing needle becomes too easy to penetrate, making sewing difficult and potentially reducing the sewing workability and the quality of the sewn product. If the initial penetration resistance value R1 and the later penetration resistance value R2 exceed the respective upper limits, the sewing needle becomes too difficult to penetrate, potentially reducing the sewing workability and the quality of the sewn product.

[0051] The difference (R2 - R1) between the later (II - stage) penetration resistance value R2 and the initial (I - stage) penetration resistance value R1 is preferably 3.5 N or more. By setting such a difference within the above range, the sewing workability and the quality of the sewn product of the electromagnetic shielding cover material 1 can be improved.

[0052] (Electromagnetic shielding property) The electromagnetic shielding property of the electromagnetic shielding cover material 1 preferably has an electromagnetic shielding property of 40 dB or more for electromagnetic waves of 10 MHz and an electromagnetic shielding property of 40 dB or more for electromagnetic waves of 1000 MHz, more preferably an electromagnetic shielding property of 50 dB or more for electromagnetic waves of 10 MHz and an electromagnetic shielding property of 50 dB or more for electromagnetic waves of 1000 MHz, and even more preferably an electromagnetic shielding property of 60 dB or more for electromagnetic waves of 10 MHz and an electromagnetic shielding property of 60 dB or more for electromagnetic waves of 1000 MHz. By the electromagnetic shielding property of the electromagnetic waves of 10 MHz and 1000 MHz being within the above ranges, the electromagnetic shielding property of the electromagnetic shielding cover material 1 is enhanced.

[0053] (Rigidity-flexibility) The rigidity-flexibility, which is an index of the rigidity-flexibility of the electromagnetic shielding cover material 1, is preferably 60 to 120 mm, and more preferably 70 to 110 mm. The rigidity-flexibility is measured by the measurement method described later. By setting the rigidity-flexibility within the above range, the firmness and strength of the electromagnetic shielding cover material 1 can be enhanced.

[0054] (Surface resistance value (conductivity)) The surface resistance value, which is an index of the conductivity of the electromagnetic shielding cover material 1, is preferably 0.300 Ω / □ or less. The surface resistance value is measured by the measurement method described later. By setting the surface resistance value within the above range, the conductivity is further enhanced.

[0055] (Flexure durability) The flexure durability of the electromagnetic shielding cover material 1 is measured by the measurement method described later, and the change rate (%) of the surface resistance value before the flexure test (initial) with respect to the surface resistance value after the flexure test can be used as an index. Such a change rate is preferably 40% or less. By the above change rate being 40% or less, the flexure durability is more excellent.

[0056] (Friction durability) The frictional durability of the electromagnetic shielding cover material 1 can be measured by the measurement method described later, and the change rate (%) of the surface resistance value before the friction test (initial) with respect to the surface resistance value after the friction test can be used as an index. Such a change rate is preferably 40% or less. When the above change rate is 40% or less, the frictional durability becomes more excellent.

[0057] (Durability in a humid and hot environment) The durability of the electromagnetic shielding cover material 1 in a humid and hot environment can be measured by the measurement method described later, and the change rate (%) of the surface resistance value before the humid and hot environment test (initial) with respect to the surface resistance value after the humid and hot environment test can be used as an index. Such a change rate is preferably 40% or less. When the above change rate is 40% or less, the durability in a humid and hot environment becomes more excellent.

[0058] (Durability in neutral salt water) The durability of the electromagnetic shielding cover material 1 in neutral salt water can be measured by the measurement method described later, and the change rate (%) of the surface resistance value before the neutral salt water test (initial) with respect to the surface resistance value after the neutral salt water test can be used as an index. Such a change rate is preferably 50% or less. When the above change rate is 50% or less, the durability in neutral salt water becomes more excellent.

[0059] >[Use of the electromagnetic shielding cover material]< The electromagnetic shielding cover material 1 is preferably used for preventing misreading in radio frequency identification (RFID). In this case, the electromagnetic shielding cover material 1 can be suitably used for logistics management.

[0060] As described above, the electromagnetic shielding cover material 1 of the present embodiment is excellent not only in electromagnetic shielding performance, but also in durability, product shape retention, sewing workability, and the quality of sewn products.

[0061] [Cover for electromagnetic shielding] FIG. 2 is a schematic perspective view showing an electromagnetic shielding cover 10 formed by sewing the electromagnetic shielding cover material 1 of the present embodiment, a storage vault 100 as an example to which it is applied, and a state in which the electromagnetic shielding cover 10 is applied to the storage vault 100. The electromagnetic shielding cover 10 of the present embodiment is formed by sewing the electromagnetic shielding cover material 1 of the present embodiment. The shape of the electromagnetic shielding cover 10 and the quantity of the electromagnetic shielding cover material 1 used for sewing the electromagnetic shielding cover 10 are not particularly limited and can be set as appropriate. As the sewing method, a conventionally known sewing method can be used.

[0062] The electromagnetic shielding cover 10 is obtained by sewing a plurality of electromagnetic shielding cover materials 1 so as to have dimensions for covering, for example, the storage vault 100 or the like. Specifically, as shown in FIG. 2(b), when covering a box-shaped storage vault 100 with a length L of 800 mm, a width W of 1200 mm, and a height H of 1500 mm excluding the front opening / closing door, the electromagnetic shielding cover 10 shown in FIG. 2(a) can be formed by sewing four electromagnetic shielding cover materials 1 so as to have dimensions of 4000 mm or more in length and 3000 mm or more in width. Then, as shown in FIG. 2(c), the storage vault 100 can be covered with the electromagnetic shielding cover 10.

[0063] According to the electromagnetic shielding cover 10 (that is, the electromagnetic shielding cover material 1) in the aspect shown in FIG. 2, electromagnetic waves from above, in the left-right direction, and from the rear of the storage vault 100 can be shielded. However, the electromagnetic shielding cover 10 is not limited to such an aspect, and for example, as shown in FIG. 3, an aspect of shielding only the direction where shielding is required can be adopted. Also, for example, as shown in FIG. 4, an aspect of combining the electromagnetic shielding cover 10 with a wall portion or the like having electromagnetic shielding properties to shield electromagnetic waves can also be adopted.

[0064] FIG. 3 is a schematic perspective view showing an electromagnetic shielding cover 10 formed by sewing the electromagnetic shielding cover material 1 of the present embodiment, another example of a partition 200 and a curtain 300 to which it is applied, and a state in which the electromagnetic shielding cover 10 is applied to the partition 200 and the curtain 300, respectively. In the aspect shown in FIG. 3(a), the electromagnetic shielding cover 10 covers a U-shaped partition frame 210 (viewed from above), and the partition 200 is constituted by the electromagnetic shielding cover 10 and the partition frame 210. By configuring in this way, according to the shape of the partition 200 (that is, the partition frame 210), it is possible to shield electromagnetic waves from the direction covered by the partition 200. Further, in the aspect shown in FIG. 3(b), the electromagnetic shielding cover 10 is suspended in a curtain shape on a U-shaped curtain rail 310 installed on the ceiling 350 (viewed from above), and the curtain 300 is constituted by the electromagnetic shielding cover 10 and the curtain rail 310. By configuring in this way, according to the shape of the curtain 300 (that is, the curtain rail 310), it is possible to shield electromagnetic waves from the direction covered by the curtain 300.

[0065] Although illustration is omitted, in Fig. 3(a), a flat partition frame is installed at the upper end of the U-shaped partition frame 210 to serve as a ceiling, and the ceiling is covered with the electromagnetic wave shielding cover 10. Also, a flat partition frame may be installed in an openable and closable manner at the open portion (front in Fig. 3(a)) of the partition frame 210 to serve as a door, and the door may be covered with the electromagnetic wave shielding cover 10. According to such an aspect, the space surrounded by the partition frame 210, the ceiling, and the door becomes a space where electromagnetic waves from the surroundings are blocked, and it becomes possible to use the space as a shield room. Although illustration is omitted, in Fig. 3(b), a curtain rail 310 may be formed in a C shape, and a curtain-shaped electromagnetic wave shielding cover 10 may be suspended from the curtain rail 310. According to such an aspect, the space surrounded by the curtain-shaped electromagnetic wave shielding cover 10 becomes a space where electromagnetic waves from the surroundings are blocked, and it becomes possible to use the space as a shield room. In this case, if necessary, a ceiling may be installed by bridging a frame (illustration omitted) over the curtain rail 310, etc., and the ceiling may be covered with the electromagnetic wave shielding cover 10. According to such an aspect, it becomes possible to use the space surrounded by the curtain-shaped electromagnetic wave shielding cover 10 and the ceiling as a shield room.

[0066] FIG. 4 is a schematic perspective view showing an electromagnetic shielding cover 10 formed by sewing the electromagnetic shielding cover material 1 of the present embodiment, another example of a radio frequency identification (RFID) reader 400 to which it is applied, and a state in which the electromagnetic shielding cover 10 is applied to the RFID reader 400. In the aspect shown in FIG. 4, the electromagnetic shielding cover 10 is attached to the RFID reader 400. As shown in FIG. 4(a), the RFID reader 400 includes two side wall portions 410 arranged opposite to each other and an upper wall portion 430 connecting the upper end portions of the two side wall portions 410, and a radio frequency identification (RFID) reading portion 450 is provided on the upper wall portion 430. The two side wall portions 410 and the portions of the upper wall portion 430 other than the RFID reading portion 450 all have electromagnetic shielding properties. When an article 470 provided with an IC tag 490 for RFID reading passes from one side (for example, the rear in FIG. 4) to the other side (for example, the front in FIG. 4) through the space (passage) portion surrounded by the two side wall portions 410 and the upper wall portion 430, the IC tag 490 is read by the RFID reading portion 450 on the upper wall portion 430. At this time, the side wall portions 410 and the upper wall portion 430 shield electromagnetic waves from above and from the side (left and right directions). However, these side wall portions 410 and the upper wall portion 430 alone cannot shield electromagnetic waves from the front and the rear. Therefore, in order to shield such electromagnetic waves from the front and / or the rear, in the aspects shown in FIGS. 4(b) and 4(c), the electromagnetic shielding cover 10 is attached to the upper wall portion 430 so as to openably and closably cover the space portion surrounded by the side wall portions 410 and the upper wall portion 430. Specifically, in the aspect shown in FIG. 4(b), a curtain-shaped electromagnetic shielding cover 10 is attached to the upper wall portion 430. In the aspect shown in FIG. 4(c), a noren-shaped electromagnetic shielding cover 10 is attached to the upper wall portion 430. In this way, by combining the electromagnetic shielding cover 10 with the side wall portions 410 and the upper wall portion 430 having electromagnetic shielding properties, misreading of the RFID reader 400 can be further prevented. Further, in this way, by using the electromagnetic shielding cover 10 (that is, the electromagnetic shielding cover material 1) for preventing misreading in RFID, it can be suitably used for logistics management.

[0067] According to the electromagnetic wave shielding cover 10 of the present embodiment, as described above, the electromagnetic wave shielding cover material 1 excellent in electromagnetic wave shielding property, durability, product shape retention property, sewing workability, and sewing product quality is sewn, so that while reducing sewing defects, the electromagnetic wave shielding property, durability, product shape retention property, sewing workability, and sewing product quality inherent in the electromagnetic wave shielding cover material 1 can be exhibited.

Example

[0068] [Example 1] (Production of the first fabric) As shown in Table 1, using a warp thread with a yarn fineness of 56 dtex and a yarn density of 160 threads / 2.54 cm, and a weft thread with a yarn fineness of 56 dtex and a yarn density of 120 threads / 2.54 cm, and weaving in a plain weave so as to obtain the cover factor (CF) shown in Table 1 and the basis weight of the electromagnetic wave shielding cover material, a first fabric, which is a woven fabric, was obtained. The thickness of the first fabric was set so that the thickness of the laminate (metal film formed fabric) in which the metal film was formed on the first fabric and the sum of the thickness and the thickness of the support layer would be the values shown in Table 1, respectively.

[0069] The cover factor (CF) of the first fabric was calculated by the following formula (1) using the product of the respective weaving densities N and the total fineness D of the warp and weft threads. CF = Nw×(Dw) 1 / 2 + Nf×(Df) 1 / 2 ··· (1) Nw and Nf are the weaving densities (threads / 2.54 cm) of the warp and weft threads, respectively, and Dw and Df are the total finenesses (dtex) of the warp and weft threads, respectively.

[0070] (Formation of the metal film) For the first fabric, a catalyst for electroless plating was applied with a colloidal solution containing lead chloride (PbCl2) and tin chloride (SnCl2). Then, electroless copper (Cu) plating and then electroplated nickel (Ni) plating were successively carried out to perform metal plating so as to obtain the metal amounts shown in Table 1. In the electroless copper plating, a plating solution containing copper chloride (CuCl2), formaldehyde, and sodium hydroxide was used. In the electroplated nickel plating, a plating solution containing nickel sulfate hexahydrate (NiSO4·6H2O) and sodium citrate was used.

[0071] In this way, a metal film-forming fabric in which a metal plating film (metal film) is formed on the entire surfaces and end faces (i.e., the whole of the first fabric) of the first fabric was obtained.

[0072] (Lamination of the metal film-forming fabric and the support layer) A vinyl chloride (PVC) film was used as the support layer, and the metal film-forming fabric and the support layer were laminated by lamination. The thickness of the support layer is shown in Table 1. In this way, an electromagnetic shielding cover material of Example 1 in which the metal film-forming fabric and the support layer are laminated was obtained.

[0073] [Examples 2 to 19, Comparative Examples 1 to 4] Except for changing to the conditions shown in Tables 1 to 5, electromagnetic shielding cover materials of Examples 2 to 19 and Comparative Examples 1 to 4 were obtained in the same manner as in Example 1. In Tables 1 to 5, "PET fabric" represents a fabric woven in a plain weave using polyethylene terephthalate (PET) yarns, corresponding to the second fabric. "PET fabric (double weave)" represents a fabric woven in a double weave using polyethylene terephthalate (PET) yarns, corresponding to the second fabric. "PET film" represents a polyethylene terephthalate film, and "PE film" represents a polyethylene film. "Sewing" in the method of laminating the metal film-forming fabric and the support layer indicates that the metal film-forming fabric and the support layer were sewn together. In Comparative Example 1, the support layer was not laminated on the metal film-forming fabric. In Comparative Example 4, instead of metal plating, metal vapor deposition was performed to deposit copper (Cu) and nickel (Ni) in this order only on one side (single side) of the fabric to form a metal vapor deposition layer (metal film).

[0074] The electromagnetic shielding cover materials of Examples 1 to 19 and Comparative Examples 1 to 4 were evaluated as follows. The results are shown in Tables 1 to 5.

[0075] [Penetration resistance value] The penetration resistance value of the electromagnetic wave shielding cover material was measured by a method in accordance with the measurement method of ASTM D 4833. FIG. 5 is a schematic diagram for explaining an example of the penetration resistance test and the penetration resistance force. Note that FIG. 5 is a diagram showing the mechanism of the penetration test and the concept of the penetration resistance force, and the dimensions of the perforating needle actually used were set as follows. In ASTM D 4833, the measurement is performed using a cylindrical penetration rod with a diameter of 8 mm. In this test, instead of the penetration rod, a perforating needle (reference numeral 1000 in FIG. 5) having a total length of 40 mm and a diameter of 2 mm, which is formed in a conical shape over 25 mm from the tip, was used. Specifically, the perforating needle 1000 has a total length (tip portion + base portion) of 40 mm, the tip portion is a cone with a length of 25 mm and a bottom diameter of 2 mm, and the base portion is a cylinder with a length of 15 mm and a cross-sectional diameter of 2 mm. The perforating needle 1000 protrudes from the mounting portion (length 17 mm) to the test apparatus so as to have the above dimensions, and the total length of the penetration jig including the perforating needle 1000 and the mounting portion is 57 mm. The dropping speed of the perforating needle 1000 was 300 mm / min. As shown in FIG. 5, in the I period (initial period), the penetration resistance is during the period when the tip portion of the perforating needle 1000 contacts one surface (support layer side or the side where the metal film is not formed) α of the electromagnetic wave shielding cover material and penetrates to the other surface β of the electromagnetic wave shielding cover material (in FIG. 5, between the state of the first perforating needle 1000 from the left and the state of the second perforating needle 1000 from the left). That is, in the initial (I period), when the perforating needle 1000 is penetrated from the support layer side, it is the penetration resistance until the tip portion reaches the surface of the other metal film. The II period (latter period) is the penetration resistance during the period when the base portion reaches the surface β after the tip portion of the perforating needle 1000 penetrates the electromagnetic wave shielding cover material (in FIG. 5, between the state of the second perforating needle 1000 from the left and the state of the third perforating needle 1000 from the left). That is, in the latter (II period), it is the penetration resistance until the base portion reaches the surface of the metal film on the other surface side. The III period (final period) is the penetration resistance when the conical tip portion of the perforating needle 1000 exceeds the other surface β and the base portion with a diameter of 2 mm (cylindrical portion) passes through the electromagnetic wave shielding cover material (state of the fourth perforating needle 1000 from the left in FIG. 5).In this test, the maximum value of the penetration resistance in the initial (Phase I) was measured as the initial (Phase I) penetration resistance value R1 (N), and the maximum value of the penetration resistance in the later stage (Phase II) was measured as the later stage (Phase II) penetration resistance value R2 (N). Also, the difference (R2 - R1) (N) between the initial (Phase I) penetration resistance value R1 and the later stage (Phase II) penetration resistance value R2 was calculated.

[0076] [Electromagnetic shielding property] The electromagnetic shielding property (electromagnetic shielding performance, unit: dB) of the electromagnetic shielding cover material at 10 MHz and 1000 MHz was measured using the KEC (KEC Kansai Electronic Industry Promotion Center, Incorporated Association) method. Specifically, the magnetic field strength between a probe with a transmitting antenna for a signal transmitting a pseudo-noise source and a probe with a receiving antenna (the magnetic field strength in the space without the electromagnetic shielding cover material), and the magnetic field strength when an electromagnetic shielding cover material was inserted between both probes (the magnetic field strength in the space with the electromagnetic shielding cover material) were measured. Next, 10 MHz and 1000 MHz were each transmitted as pseudo-noise sources, the difference in magnetic field strength due to the presence or absence of the electromagnetic shielding cover material was obtained, and the electromagnetic shielding property (shielding effect, SE) at 10 MHz and 1000 MHz was calculated based on the following formula (2). Note that there are a probe for measuring the electric field shielding property and a probe for measuring the magnetic field shielding property for the probe, and in this example, the probe for measuring the magnetic field shielding property was used. SE (shielding effect) = 20 × log10 (Mo / Mx) ··· (2) Mo: The magnetic field strength in the space without the electromagnetic shielding cover material Mx: The magnetic field strength in the space with the electromagnetic shielding cover material And the electromagnetic shielding property was evaluated according to the following criteria. (Criteria) Good: 40 dB or more at both 10 MHz and 1000 MHz Poor: Less than 40 dB in at least one of 10 MHz and 1000 MHz

[0077] [Rigidity-flexibility] The stiffness (mm) of the electromagnetic shielding cover material was measured in accordance with JIS L 1096, and the stiffness (rigidity and flexibility) of the electromagnetic shielding cover material was evaluated according to the following criteria. (Criteria) Excellent: 80 mm or more and 120 mm or less Good: 60 mm or more and less than 80 mm Poor: Less than 60 mm and more than 120 mm

[0078] [Surface resistance value (conductivity)] Using a resistance measuring instrument (manufactured by Mitsubishi Chemical Analytech Co., Ltd., Loresta MP), the surface resistance value (Ω / □) of the metal film side of the electromagnetic shielding cover material was measured by the four-terminal four-probe measurement method (JIS-K-7194), and the conductivity of the electromagnetic shielding cover material was evaluated according to the following criteria. (Criteria) Excellent: Less than 0.300 Ω / □ Good: 0.300 Ω / □ or more and 1.000 Ω / □ or less Poor: More than 1.000 Ω / □

[0079] [Durability] <Bending test> In accordance with JIS P 8115, the electromagnetic shielding cover material was bent 1000 times to conduct a bending test. Similar to the evaluation of the above "surface resistance value (conductivity)", the surface resistance value (Ω / □) of the electromagnetic shielding cover material before the start (initial) and after the test was measured. Also, the ratio (percentage) of the variation value (difference) of the surface resistance value after the test to the initial surface resistance value to the initial surface resistance value was calculated as the surface resistance variation rate (%) according to the following formula (3), and the bending durability of the electromagnetic shielding cover material was evaluated according to the following criteria. Variation rate (%) = {(Surface resistance value after the test) - (Initial surface resistivity)} / (Initial surface resistivity) × 100 ···(3) (Criteria) Good: The variation rate is 40% or less Poor: The variation rate is more than 40%

[0080] <Friction test> The friction test was conducted by rubbing the electromagnetic shielding cover material 1,000 times in accordance with JIS L 0849. Similar to the evaluation of the "surface resistance value (conductivity)", the surface resistance value (Ω / sq.) of the electromagnetic shielding cover material before the start (initial) and after the test was measured. Also, the ratio (percentage) of the variation value (difference) of the surface resistance value after the test to the initial surface resistance value to the initial surface resistance value was calculated as the variation rate (%) of the surface resistance value according to the above formula (3), and the friction durability of the electromagnetic shielding cover material was evaluated according to the following criteria. (Criteria) Good: The variation rate is 40% or less Poor: The variation rate exceeds 40%

[0081] <Humid heat environment test> The humid heat environment test was conducted by storing the electromagnetic shielding cover material at 60 °C and 90% RH for 100 hours in accordance with JIS C 7022. Similar to the evaluation of the "surface resistance value (conductivity)", the surface resistance value (Ω / sq.) of the electromagnetic shielding cover material before the start (initial) and after the test was measured. Also, the ratio (percentage) of the variation value (difference) of the surface resistance value after the test to the initial surface resistance value to the initial surface resistance value was calculated as the variation rate (%) of the surface resistance value according to the above formula (3), and the humid heat environment durability of the electromagnetic shielding cover material was evaluated according to the following criteria. (Criteria) Good: The variation rate is 40% or less Poor: The variation rate exceeds 40%

[0082] <Neutral salt water test> The neutral salt water test was conducted in accordance with JIS Z 2371. Similar to the evaluation of the "surface resistance value (conductivity)", the surface resistance value (Ω / sq.) before the start (initial) and after the test was measured. Also, the ratio (percentage) of the variation value (difference) of the surface resistance value after the test to the initial surface resistance value to the initial surface resistance value was calculated as the variation rate (%) of the surface resistance value according to the above formula (3), and the durability against neutral salt water was evaluated according to the following criteria. (Criteria) Good: The variation rate is 50% or less Poor: The variation rate exceeds 50%

[0083] [Product conformability] Using a sewing machine, by sewing four electromagnetic shielding cover materials with sewing thread, a box-shaped storage vault with a vertical length L of 800 mm, a horizontal width W of 1200 mm, and a height H of 1500 mm as shown in Fig. 2(b) was covered except for the front surface provided with an opening / closing door. The electromagnetic shielding cover with the shape shown in Fig. 2(a) was obtained so as to have dimensions and a shape that would cover it. As the sewing thread, 235 dtex PET thread was used as the upper thread and the lower thread, and each sewing was performed at 30 stitches / 10 cm. As shown in Fig. 2(c), with the electromagnetic shielding cover covering the storage vault, with a 1 m interval from the right side surface, parallel to the side surface, from the front side towards the back side, one of the two testers ran through at a speed of 7 m per second. When running through, the other tester measured the degree of flapping (the distance floating away from the storage vault) of the lower corner on the front side of the side surface of the electromagnetic shielding cover (the lower right corner in Fig. 2(c)). This was repeated 10 times, and the average value of the degree of flapping was taken as the flapping length and evaluated according to the following criteria. (Criteria) Excellent: The flapping length is 5 cm or less Good: The flapping length is more than 5 cm and 10 cm or less Poor: The flapping length is more than 10 cm

[0084] [Sewing workability] Two electromagnetic shielding cover materials were overlapped and sewn together using a sewing machine with sewing thread in two different types of sewing (circular sewing, straight sewing). As the sewing thread, 235 dtex PET thread was used as the upper thread and the lower thread, and each sewing was performed at 30 stitches / 10 cm. For circular sewing, circular sewing with a diameter of 200 mm was performed. For straight sewing, straight sewing was performed at a distance of 10 cm. Then, after sewing, the number of sewing wrinkles and fabric tears was visually confirmed and evaluated according to the following criteria. (Criteria) Excellent: No sewing wrinkles or fabric tears occur, or the total number of occurrences is 1 or less Good: The total number of occurrences of sewing wrinkles and fabric tears is 2 or more and 3 or less Poor: The total number of occurrences of sewing wrinkles and fabric tears is 4 or more, or at least a sewing needle break occurs during any sewing (sewing is impossible)

[0085] [Sewn product quality] Regarding the electromagnetic shielding cover obtained by the above "product shape retention", the number of sewing wrinkles and fabric tears was visually confirmed and evaluated according to the following criteria. (Criteria) Excellent: No sewing wrinkles or fabric tears occur, or the total number of occurrences is 4 or less. Good: The total number of occurrences of sewing wrinkles and fabric tears is 5 or more and 8 or less. Poor: The total number of occurrences of sewing wrinkles and fabric tears is 9 or more.

[0086] [Table 1]

[0087] [Table 2]

[0088] [Table 3]

[0089] [Table 4]

[0090] [Table 5]

[0091] The electromagnetic shielding cover materials of Examples 1 to 19 have metal films formed on at least both surfaces of the first fabric, and a support layer is laminated on the metal film on one surface side of the first fabric (metal film-forming fabric) where the metal film is formed. By satisfying the initial penetration resistance value R1 of 3 to 9 N and the later penetration resistance value R2 of 7 to 13 N, it has been shown that they are excellent in electromagnetic shielding properties, durability, product shape retention, sewing workability, and sewn product quality.

[0092] On the other hand, the electromagnetic shielding cover material of Comparative Example 1 without a support layer does not satisfy the penetration resistance value R1 of 3 to 9 N and does not satisfy the penetration resistance value R2 of 7 to 13 N, so the sewing workability and product quality were inferior. Comparative Examples 2 to 3, although having a support layer, do not satisfy the initial penetration resistance value R1 of 3 to 9 N and do not satisfy the later penetration resistance value R2 of 7 to 13 N, and were inferior in sewing workability and product quality. Comparative Example 4 in which a metal film was formed only on one surface of the fabric was inferior in bending durability, friction durability, durability in a humid heat environment, and water resistance to neutral salt water.

Industrial Applicability

[0093] The electromagnetic shielding cover material and the cover for electromagnetic shielding of the present invention can be suitably used, for example, as an IC using RFID.

Explanation of Symbols

[0094] 1 Electromagnetic shielding cover material 2 First fabric 3, 3a, 3b Metal film 4 Support layer 10 Cover for electromagnetic shielding

Claims

1. The first fabric; A metal coating formed on at least both sides of the first fabric; a support layer laminated on one surface of the metal coating; Equipped with According to ASTM D 4833, when a perforation needle (total length (tip + base): 40 mm, tip: cone with length 25 mm × bottom diameter 2 mm, base: cylinder with length 15 mm × cross-sectional diameter 2 mm) was inserted from the support layer side, The initial penetration resistance value R1, which is the penetration resistance value until the tip portion reaches the surface of the metal coating on the other side, is 3 to 9 N, The electromagnetic wave shielding cover material has a later penetration resistance value R2, which is the penetration resistance value until the base end reaches the surface of the metal coating on the other side, of 7 to 13 N.

2. Weight per unit area: 200 to 800 g / m ２ 2. The electromagnetic wave shielding covering material according to claim 1, which is

3. 2. The electromagnetic shielding cover material according to claim 1, wherein the support layer is a resin film or a second fabric.

4. The amount of metal in the metal coating is 10 to 40 g / m ２ 2. The electromagnetic wave shielding covering material according to claim 1, which is

5. 2. The electromagnetic shielding covering material according to claim 1, wherein the metal coating is a multi-layered product made of a copper coating and a nickel coating.

6. 2. The electromagnetic shielding covering material according to claim 1, which has a thickness of 0.2 to 1 mm.

7. 2. The electromagnetic shielding covering material according to claim 1, wherein the support layer is made of polyvinyl chloride or polyester.

8. 2. The electromagnetic shielding cover material according to claim 1, which is used to prevent misreading in radio frequency identification (RFID).

9. 9. An electromagnetic shielding cover obtained by sewing the electromagnetic shielding covering material according to claim 1.

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