electromagnetic wave shielding

Abstract

The present invention provides technology that achieves a decrease in bonding temperature, an improvement in the ability of a resin layer to release any bubbles therein, an improvement in the ease with which bonding work is performed, and a suppression of changes in appearance after bonding.　This electromagnetic wave shielding body is a laminate that blocks electromagnetic waves. The electromagnetic wave shielding body has a first dielectric layer, a second dielectric layer, a resin layer that adheres together the first dielectric layer and the second dielectric layer, and a metal mesh woven fabric positioned on the resin layer. The resin layer contains a thermoplastic ethylene vinyl acetate (EVA) resin, or a thermoplastic resin containing a block copolymer hydride in which some unsaturated bonds of a block copolymer are hydrogenated. The thermoplastic EVA resin does not contain an organic peroxide or a silane coupling agent. The tensile modulus of the resin layer at 100°C is less than 5.0×105 Pa.

Description

[Technical Field]

[0001] The present disclosure relates to an electromagnetic wave shield. [Background technology]

[0002] The electromagnetic wave shielding material described in Patent Document 1 includes a transparent substrate, an adhesive layer, and a metal mesh sheet. The adhesive layer contains a curable resin. The metal mesh sheet is made of metal foil with numerous holes formed therein using a photoresist method and an etching method or a punching method.

[0003] The glass resin laminate described in Patent Document 2 includes at least two glass plates, a silicone resin layer disposed between the two glass plates and bonding the main surfaces of the two glass plates together, and a metal layer disposed on the silicone resin layer. The metal layer has a mesh shape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-72010 [Patent Document 2] Japanese Patent Application Publication No. 2020-128314 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, a laminate is first produced by stacking a transparent substrate, an adhesive film, a metal mesh sheet, an adhesive film, and a transparent substrate in this order. The laminate is then placed in a vacuum bag, and the vacuum bag is heated to 85°C while the pressure inside the vacuum bag is reduced. The laminate is then removed from the vacuum bag and heated to 130°C to cure the adhesive sheet. Since the laminate is bonded at a high temperature of around 130°C, there is a problem in that the manufacturing cost is high.

[0006] In Patent Document 2, a silicone resin is sandwiched between two glass plates. Silicone resin has high fluidity even at room temperature and good defoaming properties. However, when the silicone resin is sandwiched between the two glass plates, there is a risk that the silicone resin may leak out from between the two glass plates, which makes it difficult to work with. In addition, silicone resin has a high water absorption property, which makes it prone to changes in appearance after lamination. Changes in appearance can also occur due to thermal cycling.

[0007] The problem of appearance change can also occur with polyvinyl butyral (PVB) resin, etc. PVB resin also has low fluidity at low temperatures of around 100°C, which can cause problems such as poor debubbling during lamination.

[0008] One aspect of the present disclosure provides a technique that realizes a reduction in lamination temperature, an improvement in bubble release properties of a resin layer, an improvement in workability of lamination work, and suppression of changes in appearance after lamination. [Means for solving the problem]

[0009] An electromagnetic wave shield according to one embodiment of the present disclosure is a laminate that shields electromagnetic waves. The electromagnetic wave shield includes a first dielectric layer, a second dielectric layer, a resin layer that bonds the first dielectric layer and the second dielectric layer, and a woven metal mesh fabric disposed on the resin layer. The woven metal mesh fabric has openings formed by metal wires that intersect with each other. The resin layer includes a thermoplastic resin containing a thermoplastic ethylene vinyl acetate (EVA) resin or a hydrogenated block copolymer in which a portion of the unsaturated bonds of the block copolymer are hydrogenated. The thermoplastic EVA resin does not include an organic peroxide or a silane coupling agent. The tensile modulus of the resin layer at 100°C is 5.0 × 10 5 It is less than Pa. An electromagnetic wave shield according to one embodiment of the present disclosure is a laminate that shields electromagnetic waves. The electromagnetic wave shield includes a first dielectric layer, a second dielectric layer, a resin layer that bonds the first dielectric layer and the second dielectric layer, and a metal mesh fabric disposed on the resin layer. The metal mesh fabric has openings formed by metal wires that intersect with each other. The resin layer has a water absorption rate of less than 0.1%, a tensile modulus of elasticity at 25°C of 10 kPa or more, and a tensile modulus of elasticity at 100°C of 5.0 x 10, as measured in accordance with ASTM D570 (Standard Water Absorption Test Method for Plastics). 5 It is less than Pa. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, even if a metal mesh fabric having steps is disposed in the resin layer of the electromagnetic wave shielding body, the resin layer has a tensile modulus of elasticity of 5.0 × 10 at 100°C. 5 By using an EVA resin or a resin containing a hydrogenated block copolymer having a modulus of less than Pa, it is possible to reduce the lamination temperature, improve the bubble release properties of the resin layer, improve the workability of the lamination work, and suppress changes in appearance after lamination. According to one aspect of the present disclosure, even if a metal mesh fabric having steps is disposed in the resin layer of the electromagnetic wave shielding body, the water absorption rate is less than 0.1%, the tensile modulus of elasticity at 25°C is 10 kPa or more, and the tensile modulus of elasticity at 100°C is 5.0 × 10 5 By using a resin layer having a viscosity of less than Pa, it is possible to reduce the lamination temperature, improve the bubble releasing properties of the resin layer, improve the workability of the lamination work, and suppress changes in appearance after lamination. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing an electromagnetic wave shield according to an embodiment. [Figure 2] FIG. 2 is a plan view showing an example of a metal mesh fabric. [Figure 3] FIG. 3 is a cross-sectional view showing an electromagnetic wave shield according to a first modification. [Figure 4] FIG. 4 is a plan view showing an example of a slit pattern of the conductive layer. [Figure 5] FIG. 5 is a cross-sectional view showing an electromagnetic wave shield according to a second modification. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their description may be omitted. In the specification, the symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0013] First, referring to FIG. 1, an electromagnetic wave shielding body 1 according to this embodiment will be described. The electromagnetic wave shielding body 1 is a laminate that shields electromagnetic waves. The electromagnetic wave shielding body 1 reflects electromagnetic waves. As will be described later, the electromagnetic wave shielding body 1 may not only reflect electromagnetic waves but also absorb them. When the frequency of the electromagnetic waves is 100 MHz to 1 GHz, the electromagnetic wave shielding rate is preferably 40 dB or more. In the above frequency band, the electromagnetic wave shielding rate is more preferably 50 dB or more, and even more preferably 60 dB or more. In addition, in the above frequency band, the electromagnetic wave shielding rate is preferably 100 dB or less. Here, the electromagnetic wave shielding rate is measured by the KEC method (a method for measuring electromagnetic wave shielding effectiveness developed by KEC Kansai Electronics Industry Development Center, a general incorporated association).

[0014] The electromagnetic wave shielding body 1 is preferably a laminate having a visible light transmittance of 30% or more. If the visible light transmittance is 30% or more, a user can view the scenery, etc. through the electromagnetic wave shielding body 1. The electromagnetic wave shielding body 1 is used, for example, as window glass for buildings or vehicles. The visible light transmittance is more preferably 40% or more, even more preferably 50% or more, and particularly preferably 60% or more. In addition, the visible light transmittance is preferably 90% or less. The visible light transmittance is measured in accordance with Japanese Industrial Standard JIS R 3106:1998 and calculated using a calculation formula when a standard D65 light source is used.

[0015] The electromagnetic wave shielding body 1 has a first dielectric layer 2, a second dielectric layer 3, and a resin layer 4 that bonds the first dielectric layer 2 and the second dielectric layer 3. The electromagnetic wave shielding body 1 also has a metal mesh fabric 5 that is disposed on the resin layer 4. The resin layer 4 includes, for example, a first adhesive layer 41 and a second adhesive layer 42. The metal mesh fabric 5 is disposed between the first adhesive layer 41 and the second adhesive layer 42. The metal mesh fabric 5 reflects electromagnetic waves.

[0016] A manufacturing method of the electromagnetic wave shielding body 1 will be briefly described. First, the first dielectric layer 2, the first adhesive layer 41, the metal mesh fabric 5, the second adhesive layer 42, and the second dielectric layer 3 are stacked in this order to form a laminate. Next, the laminate is placed in a vacuum bag, and the vacuum bag is air-baked with the pressure inside the vacuum bag reduced. The baking temperature is about 85°C. Next, the laminate is removed from the vacuum bag and heated in an autoclave while being pressurized. The heating temperature is about 100°C. As a result, the first adhesive layer 41 and the second adhesive layer 42 penetrate into the openings 52 (see FIG. 2) of the metal mesh fabric 5 and become integrated, thereby obtaining the electromagnetic wave shielding body 1.

[0017] In the present embodiment, the resin layer 4 is formed by integrating the first adhesive layer 41 and the second adhesive layer 42 with the metal mesh fabric 5 sandwiched therebetween, but the technology of the present disclosure is not limited to this. Only one of the first adhesive layer 41 and the second adhesive layer 42 may be used. Each layer constituting the electromagnetic wave shielding body 1 will be described below.

[0018] The first dielectric layer 2 may be disposed on either the indoor side or the outdoor side with respect to the second dielectric layer 3. The material of the first dielectric layer 2 is glass, ceramic, or resin. From the viewpoint of weight reduction, the material of the first dielectric layer 2 is preferably resin. Specific examples of resin include polyethylene terephthalate (PET) resin, polycarbonate (PC) resin, and acrylic resin. On the other hand, from the viewpoint of scratch resistance, the material of the first dielectric layer 2 is preferably glass or ceramic.

[0019] When the first dielectric layer 2 is a glass plate, the glass plate is manufactured by, for example, the float method or the fusion method. The glass plate is made of, for example, soda-lime glass, alkali-free borosilicate glass, borosilicate glass, high-silica glass, or other oxide-based glass containing silicon oxide as a main component.

[0020] When the first dielectric layer 2 is a glass plate or a ceramic plate, its thickness is, for example, 0.1 mm to 10 mm, preferably 1.0 mm to 10 mm, more preferably 1.0 mm to 5.0 mm, even more preferably 1.8 mm to 4.0 mm, and particularly preferably 1.8 mm to 3.0 mm. On the other hand, when the first dielectric layer 2 is a resin plate, its thickness is, for example, 0.1 mm to 10 mm, preferably 2.0 mm to 5.0 mm, and more preferably 2.0 mm to 4.0 mm.

[0021] When the first dielectric layer 2 is a glass plate, its average linear expansion coefficient at 50°C to 350°C is, for example, 120 × 10 -7 / °C or less, preferably 100 × 10 -7 / °C or less, and more preferably 90 × 10 -7 / °C or less. Warping or breakage due to temperature changes can be suppressed. The average linear expansion coefficient is measured in accordance with Japanese Industrial Standard JIS R 3102:1995 using a differential thermal dilatometer. The average linear expansion coefficient of the glass plate is, for example, 30 × 10 -7 / ℃ or more, 50 × 10 -7 / ℃ or more, 70 × 10 -7 / °C or more.

[0022] The second dielectric layer 3 is configured in the same manner as the first dielectric layer 2, and therefore a description thereof will be omitted. However, the combination of materials for the first dielectric layer 2 and the second dielectric layer 3 is not particularly limited. The first dielectric layer 2 and the second dielectric layer 3 may be made of the same material or different materials. As described above, the material for the first dielectric layer 2 and the second dielectric layer 3 is glass, ceramic, or resin.

[0023] The metal mesh fabric 5 is preferably manufactured using a loom. As shown in FIG. 2, the metal mesh fabric 5 is made by weaving metal wires 51 vertically and horizontally. The metal mesh fabric 5 includes a plurality of metal wires 51 that intersect with each other. The metal wires 51 are arranged in a mesh portion, and openings 52 are formed in the mesh portions. The shape of the openings 52 is, for example, rectangular. The rectangle includes a square. The shape of the openings 52 is not limited to a rectangle, and may be a triangle, rhombus, trapezoid, or polygon with pentagons or more sides. The resin of the resin layer 4 enters the openings 52 during lamination.

[0024] The opening rate of the metal mesh fabric 5 is, for example, 50% to 90%. If the opening rate is 50% or more, the electromagnetic wave shielding performance of the electromagnetic wave shielding body 1 is maintained, while the visible light transmittance is high, the visibility is good, and the bubble release property of the resin layer 4 during lamination is also good. The opening rate is preferably 60% or more, more preferably 70% or more, and even more preferably 75% or more. On the other hand, if the opening rate is 90% or less, the electromagnetic wave shielding rate of the electromagnetic wave shielding body 1 is high. The opening rate is preferably 80% or less. The opening rate is measured in a plan view.

[0025] The material of the metal wires 51 constituting the metal mesh fabric 5 may be, for example, a single metal element or an alloy. The material of the metal wires 51 is, for example, iron, copper, brass, stainless steel (SUS steel), aluminum, nickel, tungsten, or nichrome. The metal wires 51 may also be made by twisting together a plurality of metal fibers.

[0026] The wire diameter (diameter) of the metal wire 51 is, for example, 10 μm to 200 μm. If the wire diameter of the metal wire 51 is 10 μm or more, breakage such as wire breakage is reduced and handling is easy. The wire diameter of the metal wire 51 is preferably 20 μm or more. On the other hand, if the wire diameter of the metal wire 51 is 200 μm or less, the metal wire 51 is not noticeable to the naked eye and visibility is good. The wire diameter of the metal wire 51 is preferably 100 μm or less, and more preferably 60 μm or less.

[0027] The pitches P1 and P2 of the metal wires 51 are each, for example, 50 μm to 1000 μm. If the pitches P1 and P2 are each 50 μm or more, the electromagnetic wave shielding body 1 has high visible light transmittance, good transparency, and good bubble removal properties of the resin layer 4 during lamination. The pitches P1 and P2 are each preferably 100 μm or more, more preferably 150 μm or more. On the other hand, if the pitches P1 and P2 are each 1000 μm or less, the electromagnetic wave shielding rate of the electromagnetic wave shielding body 1 is high. The pitches P1 and P2 are each preferably 500 μm or less, more preferably 250 μm or less.

[0028] The metal mesh fabric 5 may be a heating element and may be connected to an electrode to generate heat. When the electrode passes a current through the metal mesh fabric 5, Joule heat is generated. The generated heat removes condensation on the surface of the electromagnetic wave shielding material 1.

[0029] Incidentally, when the metal mesh fabric 5 of this embodiment is manufactured using a loom, it can be manufactured at low cost without using photolithography, etching, or punching, unlike the metal mesh sheet of Patent Document 1. Therefore, the metal mesh fabric 5 can reduce the manufacturing cost of the electromagnetic wave shielding body 1 compared to the metal mesh sheet.

[0030] However, unlike the metal mesh sheet of Patent Document 1, the metal mesh fabric 5 of this embodiment has steps at the intersections of multiple metal wires 51. The height of the steps is approximately two to three times the wire diameter of the metal wires 51, and is, for example, 100 μm to 3000 μm, preferably 200 μm to 1500 μm, and more preferably 300 μm to 750 μm. These steps deteriorate the bubble releasing properties of the resin layer 4 during lamination. Therefore, in order to improve the bubble releasing properties of the resin layer 4 during lamination, it is considered to use the silicone resin of Patent Document 2 as the resin for the resin layer 4.

[0031] However, silicone resin has high fluidity even at room temperature, and there is a risk of leakage when sandwiched between the first dielectric layer 2 and the second dielectric layer 3, resulting in poor workability. Silicone resin also has high water absorption, and is prone to changes in appearance after lamination. Changes in appearance can also occur due to thermal cycling.

[0032] In this specification, the term "change in appearance" includes bubbles, discoloration (e.g., cloudiness), and peeling. The change in appearance may occur at the interface between the resin layer 4 and the metal mesh fabric 5, the interface between the resin layer 4 and the first dielectric layer 2, or the interface between the resin layer 4 and the second dielectric layer 3.

[0033] The problem of appearance changes due to high water absorption can also occur with polyvinyl butyral (PVB) resin, etc. PVB resin also has low fluidity at 100°C, which can cause problems such as poor debubbling during lamination.

[0034] Therefore, the resin layer 4 of this embodiment contains a thermoplastic resin containing a thermoplastic ethylene vinyl acetate (EVA) resin or a hydrogenated block copolymer in which a portion of the unsaturated bonds of the block copolymer is hydrogenated, and the tensile modulus E' of the resin layer 4 at 100°C is 5.0 × 10 5 It is less than Pa.

[0035] Tensile modulus E' is 5.0 x 10 5 If it is less than Pa, the resin of the resin layer 4 is soft and has good bubble releasing properties even when the lamination temperature is as low as about 100° C. Therefore, it is possible to lower the lamination temperature and improve the bubble releasing properties of the resin layer 4.

[0036] The tensile modulus E' is preferably 4.0 x 10 5 Pa or less, and more preferably 2.0×10 5 The tensile modulus E' is preferably 1.0 x 10 Pa or less. 4 Pa or more.

[0037] Furthermore, if the resin layer 4 contains a thermoplastic EVA resin or a thermoplastic resin containing a hydrogenated block copolymer, it will hardly flow at room temperature. Therefore, when the resin layer 4 is sandwiched between the first dielectric layer 2 and the second dielectric layer 3, there is no risk of the resin layer 4 flowing out, and workability is good. This improves the workability of the lamination operation.

[0038] Furthermore, EVA resin and resin containing hydrogenated block copolymer have lower water absorption and less change in appearance after lamination than silicone resin and PVB resin. Therefore, it is possible to suppress change in appearance after lamination. Furthermore, EVA resin and resin containing hydrogenated block copolymer have lower tensile modulus at 100°C and better defoaming properties than PVB resin.

[0039] The resin layer 4 preferably contains a resin containing a hydrogenated block copolymer. Resins containing hydrogenated block copolymers have lower water absorption than EVA resins, and cause less change in appearance after lamination. Furthermore, resins containing hydrogenated block copolymers have better adhesion to the metal wires 51 than EVA resins. Therefore, changes in appearance after lamination can be further suppressed.

[0040] The resin containing a hydrogenated block copolymer is, for example, a thermoplastic resin containing a hydrogenated block copolymer in which some of the unsaturated bonds of the block copolymer are hydrogenated, such as cycloolefin oligomer (COP). 90% or more of all the unsaturated bonds contained in the block copolymer may be hydrogenated.

[0041] The block copolymer includes a first component and a second component. The first component is a polymer block mainly composed of repeating units derived from an aromatic vinyl compound. The second component is a polymer block mainly composed of repeating units derived from a linear conjugated diene compound. The ratio (WA:WB) of the weight of the first component WA to the weight of the second component WB is 30:70 to 60:40.

[0042] The tensile modulus at 100°C of a resin containing a hydrogenated block copolymer is determined by the mixing ratio of the first and second components of the block copolymer. The smaller the proportion of the second component, the lower the softening point of the resin containing a hydrogenated block copolymer and the smaller the tensile modulus at 100°C of the resin containing a hydrogenated block copolymer. WA:WB is preferably 35:65 to 55:45, and more preferably 40:60 to 50:50.

[0043] Resins containing hydrogenated block copolymers may contain additives in addition to the hydrogenated block copolymers. The additives are conjugated polymers that are compatible with the hydrogenated block copolymers. The additives can control the tensile modulus at 100°C.

[0044] Examples of compatible conjugated polymers include hydrogenated block copolymers, which are precursors of hydrogenated block copolymers; olefin polymers such as polyethylene, polypropylene, ethylene-propylene copolymers, and propylene-ethylene-1-butene copolymers; isobutylene polymers such as polyisobutylene and hydrogenated isobutylene-isoprene copolymers; and petroleum resins and their hydrogenated products, such as 1,3-pentadiene petroleum resins, cyclopentadiene petroleum resins, and styrene-indene petroleum resins.

[0045] The resin layer 4 may contain a thermoplastic EVA resin. The thermoplastic EVA resin does not contain organic peroxides or silane coupling agents and is not thermally crosslinkable. In other words, the content of organic peroxides and silane coupling agents in the thermoplastic EVA resin is 0% by mass. Adding an organic peroxide or silane coupling agent to the EVA resin imparts thermal crosslinkability, resulting in a curable resin. Furthermore, if the EVA resin contains an organic peroxide or silane coupling agent, the EVA resin undergoes crosslinking and curing upon heating and pressurization in an autoclave. This increases the tensile modulus of the EVA resin as the crosslinking and curing process progresses, potentially leaving air bubbles between the metal mesh fabric and the EVA resin, potentially affecting transparency and reliability. On the other hand, adding an organic peroxide or silane coupling agent to a resin containing a hydrogenated block copolymer does not result in a curable resin.

[0046] The EVA resin, for example, contains 15% to 50% by weight of vinyl acetate and has a melt mass-flow rate of 0.1 g / 10 min to 100 g / 10 min as measured according to JIS K6924-1. The resin contains 0.5 to 10 parts by weight of a low-molecular-weight compound having a refractive index of 1.480 to 1.600 and a solubility parameter calculated by the Fedors method of 8.5 to 10.1, per 100 parts by weight of the EVA resin. The vinyl acetate content of the EVA resin is preferably in the range of 15% to 50% by weight, and more preferably in the range of 20% to 35% by weight, since this provides superior low-temperature adhesion to adherends and transparency. If the vinyl acetate content is 15% or higher, the resulting adhesive resin composition and molded articles thereof exhibit excellent low-temperature adhesion. On the other hand, if the vinyl acetate content is 50% or lower, the adhesiveness at room temperature is weak and the softening temperature is high, resulting in excellent blocking resistance of the resulting resin composition and molded articles. The vinyl acetate content of an EVA resin can be determined, for example, from the vinyl acetate content measured according to JIS K6924-1. The melt mass-flow rate (MFR) of the EVA resin, measured according to JIS K6924-1 at a temperature of 190°C and a load of 21.18 N, is in the range of 0.01 g / 10 min to 100 g / 10 min, and more preferably in the range of 0.5 g / 10 min to 40 g / 10 min to improve extrusion moldability. A melt mass-flow rate of 0.01 g / 10 min or higher reduces the extrusion load and resin pressure during molding, resulting in excellent processability. A melt mass-flow rate of 100 g / 10 min or lower reduces drawdown during melting, resulting in excellent handling and formability during compounding.

[0047] Low molecular weight compounds are primarily used to improve transparency. They are compounds with molecular weights of several thousand or less that have specific refractive indices and solubility parameters. Specific examples include phthalates, trimellitates, phosphates, benzoates, and sebacates, including dibutyl phthalate, tris-2-ethylhexyl trimellitate, tricresyl phosphate, triphenyl phosphate, diphenylmethane, and benzyl benzoate. Mixing EVA resin with low molecular weight compounds that have specific refractive indices and solubility parameters reduces the crystallinity of the EVA resin, improving its transparency.

[0048] The EVA resin may further contain a hydrogenated hydrocarbon resin. The hydrogenated hydrocarbon resin is blended to improve transparency and tackiness. Specific examples include aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, and aromatic hydrocarbon resins. Aliphatic hydrocarbon resins include polymers primarily composed of C4-C5 mono- or diolefins such as 1-butene, butadiene, isobutylene, and 1,3-pentadiene. Alicyclic hydrocarbon resins include resins obtained by cyclodimerizing and polymerizing diene components in spent C4-C5 fractions, and resins obtained by polymerizing cyclic monomers such as cyclopentadiene. Aromatic hydrocarbon resins include resins containing C2 vinyl aromatic hydrocarbon resins such as vinyltoluene, indene, and α-methyltoluene. Among these hydrocarbon resins, partially hydrogenated petroleum hydrocarbon resins with low softening temperatures are more preferred in terms of compatibility with ethylene-vinyl acetate copolymers and color. The blending amount of hydrogenated hydrocarbon resin relative to EVA resin is in the range of 5 to 30 parts by weight, and more preferably in the range of 10 to 20 parts by weight, since this gives a resin composition that is excellent in the transparency and tackiness of the molded product as well as in the handling of the molded product at room temperature.

[0049] Alternatively, the resin layer 4 of this embodiment has a water absorption rate of less than 0.1% as measured in accordance with ASTM D570 (standard water absorption test method for plastics), a tensile modulus of elasticity of the resin layer 4 at 25°C of 10 kPa or more, and a tensile modulus of elasticity E' of the resin layer 4 at 100°C of 5.0 × 105 It is less than Pa.

[0050] Tensile modulus E' is 5.0 x 10 5 If it is less than Pa, the resin of the resin layer 4 is soft and has good bubble releasing properties even when the lamination temperature is as low as about 100° C. Therefore, it is possible to lower the lamination temperature and improve the bubble releasing properties of the resin layer 4.

[0051] The tensile modulus E' is preferably 4.0 x 10 5 Pa or less, and more preferably 2.0×10 5 The tensile modulus E' is preferably 1.0 x 10 Pa or less. 4 Pa or more.

[0052] If the resin layer 4 has a tensile modulus of elasticity of 10 kPa or more at 25°C, it will hardly flow at room temperature. Therefore, when the resin layer 4 is sandwiched between the first dielectric layer 2 and the second dielectric layer 3, there is no risk of the resin layer 4 flowing out, and workability is good. This improves the workability of the lamination operation. The tensile modulus of elasticity at 25°C is preferably 30 kPa or more, and more preferably 50 kPa or less.

[0053] If the resin layer 4 has a water absorption rate of less than 0.1% as measured in accordance with ASTM D570 (standard water absorption test method for plastics), the resin layer 4 has low water absorption and can suppress changes in appearance after lamination. The water absorption rate is preferably 0.05% or less, and more preferably 0.03% or less.

[0054] The resin layer 4 may be, for example, a resin containing thermoplastic polyurethane (TPU). Thermoplastic polyurethane is obtained, for example, by copolymerizing polyisocyanate, polymer polyol, and chain extender. The tensile modulus of thermoplastic polyurethane (TPU) varies depending on the inter-crosslink molecular weight, which is the molecular weight between the linking functional group of polyisocyanate and the linking functional group of polymer polyol. Specifically, the modulus of elasticity tends to decrease as the inter-crosslink molecular weight increases, and tends to increase as the inter-crosslink molecular weight decreases.

[0055] Examples of polyisocyanates include aliphatic, alicyclic, and aromatic diisocyanates, which can reduce water absorption, and aromatic diisocyanates are preferred. More specifically, examples include aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate; alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate; and aromatic diisocyanates such as p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, and 4,4'-diphenylmethane diisocyanate. Among these, 4,4'-diphenylmethane diisocyanate is preferred.

[0056] The polymer polyol is preferably a polyether polyol or polyester polyol having a molecular weight of about 500 to 8,000, more preferably about 600 to 4,000.

[0057] Examples of polyether polyols include polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethyleneoxypropylene glycol, polyoxytetramethylene glycol, polyoxyhexamethylene glycol, etc. Among these, polyoxytetramethylene glycol is preferred.

[0058] The polyester polyol is preferably an aliphatic polyester polyol derived from an aliphatic dicarboxylic acid and an aliphatic diol, which can reduce water absorption. More specifically, examples of the polyester polyol include polyethylene adipate, polytetramethylene adipate, polyhexamethylene adipate, polytetramethylene sebacate, poly(diethylene glycol adipate), poly(hexamethylene glycol-1,6-carbonate), and polycaprolactone, which have diol components at both ends.

[0059] Examples of the chain extender include diols having a molecular weight of preferably 400 or less, more preferably 300 or less. Specific examples include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, bisphenol A, and p-xylylene glycol.

[0060] Next, an electromagnetic wave shielding device 1 according to a first modification will be described with reference to Fig. 3 and Fig. 4. Similar to the electromagnetic wave shielding device 1 according to the above embodiment, the electromagnetic wave shielding device 1 according to this modification includes a first dielectric layer 2, a second dielectric layer 3, and a resin layer 4 that bonds the first dielectric layer 2 and the second dielectric layer 3 together. The electromagnetic wave shielding device 1 further includes a metal mesh fabric 5 that is disposed on the resin layer 4. The resin layer 4 includes, for example, a first adhesive layer 41 and a second adhesive layer 42. The metal mesh fabric 5 is disposed between the first adhesive layer 41 and the second adhesive layer 42.

[0061] Unlike the electromagnetic wave shielding body 1 of the above embodiment, the electromagnetic wave shielding body 1 of this modified example has a third dielectric layer 6 arranged on the opposite side of the second dielectric layer 3 from the first dielectric layer 2, and a conductive layer 7 arranged between the second dielectric layer 3 and the third dielectric layer 6.

[0062] 4, the conductive layer 7 includes a plurality of conductors 71-1 to 71-4 that are spaced apart from one another and insulated from one another. The conductive layer 7 is preferably a transparent conductive film such as an ITO (indium tin oxide) film. The conductive layer 7 may also be a so-called FSS (frequency selective shield).

[0063] The conductive layer 7 reflects a portion of the electromagnetic waves propagating in the direction of arrow A in Figure 3, absorbs another portion, and transmits the remainder. The electromagnetic waves that have transmitted through the conductive layer 7 are reflected by the metal mesh fabric 5. The electromagnetic waves reflected by the conductive layer 7 and the electromagnetic waves reflected by the metal mesh fabric 5 interfere with each other and cancel each other out. As a result, the electromagnetic waves are absorbed.

[0064] When the electromagnetic wave reaches the conductive layer 7, free electrons in the conductors 71-1 to 71-4 move in the direction opposite to the electric field direction of the electromagnetic wave, causing a current to flow through the conductors 71-1 to 71-4. At this time, energy is periodically accumulated and released in the gaps between the conductors 71-1 to 71-4 due to the electric field generated. As a result, a propagation delay occurs in the electromagnetic wave passing through the conductive layer 7. In other words, a delay occurs between the electromagnetic wave entering the conductive layer 7 and the time it is re-radiated. Therefore, the distance between the conductive layer 7 and the metal mesh fabric 5 can be made shorter than λ / 4, allowing the electromagnetic wave shielding body 1 to be made thinner.

[0065] 4, the conductive layer 7 includes a plurality of first slits 72 and a plurality of second slits 73 that are perpendicular to each other and serve as gaps separating the plurality of conductors 71-1 to 71-4. The plurality of first slits 72 and the plurality of second slits 73 form a tetragonal lattice, and the conductors 71-1 to 71-4 are formed in a rectangular shape in plan view. The rectangular shape includes a square.

[0066] The interval between adjacent first slits 72 is set alternately to a first interval L1 and a second interval L2 that is smaller than the first interval L1. Similarly, the interval between adjacent second slits 73 is also set alternately to the first interval L1 and the second interval L2. As a result, four types of conductors 71-1, 71-2, 71-3, and 71-4 are formed in a plan view.

[0067] Conductor 71-1 is a square with four sides each having a length of L1. Conductor 71-2 is a square with four sides each having a length of L2. The remaining two conductors 71-3 and 71-4 have two opposing sides each having a length of L1 and two remaining sides each having a length of L2.

[0068] The average perimeter of the four types of conductors 71-1 to 71-4 is expressed by the formula 2 × (L1 + L2). The average perimeter is, for example, 60 mm to 180 mm, and preferably 80 mm to 150 mm.

[0069] Although L1 and L2 are different in this modification, they may be the same. In this case, the average perimeter is also expressed by the formula 2×(L1+L2).

[0070] The line width G of each of the first slit 72 and the second slit 73 is preferably, for example, 30 μm to 150 μm. If G is 30 μm or more, processing is easy. If G is 150 μm or less, the electric field generated between the conductors 71-1 to 71-4 is strong, and the delay time is long. In this embodiment, the line width of the first slit 72 and the line width of the second slit 73 are the same, but they may be different.

[0071] As shown in Fig. 3, the conductive layer 7 is preferably formed on the surface of the second dielectric layer 3 facing the third dielectric layer 6. For example, a transparent conductive film is formed on the facing surface by vapor deposition, sputtering, or the like, and the formed transparent conductive film is patterned by laser processing or the like. The conductive layer 7 may also be formed by printing using a conductive ink. The conductive layer 7 is adhered to the third dielectric layer 6 via a third adhesive layer 8.

[0072] In this modification, the conductive layer 7 is formed on the surface of the second dielectric layer 3 facing the third dielectric layer 6, and the third adhesive layer 8 is disposed between the conductive layer 7 and the third dielectric layer 6; however, the technology of the present disclosure is not limited to this. For example, the conductive layer 7 may be formed on the surface of the third dielectric layer 6 facing the second dielectric layer 3, and the third adhesive layer 8 may be disposed between the conductive layer 7 and the second dielectric layer 3. Alternatively, the conductive layer 7 may be formed on an insulating base material (not shown), and the third adhesive layer 8 may be disposed between the conductive layer 7 and the second dielectric layer 3, and between the conductive layer 7 and the third dielectric layer 6.

[0073] The third dielectric layer 6 protects the conductive layer 7. Like the first dielectric layer 2 and the second dielectric layer 3, the third dielectric layer 6 is made of glass, ceramics, or resin. From the viewpoint of weight reduction, the material of the third dielectric layer 6 is preferably resin. Specific examples of resin include PET resin, PC resin, and acrylic resin. On the other hand, from the viewpoint of scratch resistance, the material of the third dielectric layer 6 is preferably glass or ceramics.

[0074] When the third dielectric layer 6 is a glass plate or a ceramic plate, its thickness is, for example, 1.8 mm to 4.0 mm, and preferably 1.8 mm to 3.0 mm. On the other hand, when the third dielectric layer 6 is a resin plate, its thickness is, for example, 2.0 mm to 5.0 mm, and preferably 2.0 mm to 4.0 mm.

[0075] When the third dielectric layer 6 is a glass plate, the tan δ (also referred to as the dielectric loss tangent) of the glass plate is preferably 0.025 or less, more preferably 0.020 or less, and even more preferably 0.010 or less. The tan δ of the glass plate is preferably 0.0001 or more. The relative dielectric constant of the glass plate is preferably 8 or less, more preferably 6 or less. The relative dielectric constant of the glass plate is preferably 3.5 or more.

[0076] When the third dielectric layer 6 is a resin plate, the tan δ of the resin plate is preferably 0.2 or less, more preferably 0.1 or less. The tan δ of the resin plate is preferably 0.0005 or more. The relative dielectric constant of the resin plate is preferably 5 or less, more preferably 4 or less. The relative dielectric constant of the resin plate is preferably 2 or more.

[0077] Here, tan δ is a value expressed as ε2 / ε1 using the complex dielectric constant, where ε1 is the relative permittivity and ε2 is the dielectric loss. The smaller the value of tan δ, the less radio wave absorption there is in that frequency band. Tan δ and the relative permittivity are values ​​measured at a measurement frequency of 1 GHz according to the method specified in IEC (International Electrotechnical Commission) 61189-2-721 (2015).

[0078] Next, an electromagnetic wave shielding device 1 according to a second modification will be described with reference to Fig. 5. Like the electromagnetic wave shielding device 1 according to the above embodiment, the electromagnetic wave shielding device 1 according to this modification also includes a first dielectric layer 2, a second dielectric layer 3, and a resin layer 4 that bonds the first dielectric layer 2 and the second dielectric layer 3 together. The electromagnetic wave shielding device 1 further includes a metal mesh fabric 5 that is disposed on the resin layer 4. The resin layer 4 includes, for example, a first adhesive layer 41 and a second adhesive layer 42. The metal mesh fabric 5 is disposed between the first adhesive layer 41 and the second adhesive layer 42.

[0079] Unlike the electromagnetic wave shielding body 1 of the above embodiment, the electromagnetic wave shielding body 1 of this modified example has a third dielectric layer 6 arranged on the opposite side of the second dielectric layer 3 from the first dielectric layer 2, and an air layer 9 arranged between the second dielectric layer and the third dielectric layer 6. The air layer 9 is surrounded by a spacer 10. The air layer 9 ensures heat insulation.

[0080] The third dielectric layer 6 is made of glass, ceramics, or resin, similar to the first dielectric layer 2 and the second dielectric layer 3. From the viewpoint of weight reduction, the material of the third dielectric layer 6 is preferably resin. Specific examples of resin include PET resin, PC resin, and acrylic resin. On the other hand, from the viewpoint of scratch resistance, the material of the third dielectric layer 6 is preferably glass or ceramics.

[0081] When the third dielectric layer 6 is a glass plate or a ceramic plate, its thickness is, for example, 1.8 mm to 4.0 mm, and preferably 1.8 mm to 3.0 mm. On the other hand, when the third dielectric layer 6 is a resin plate, its thickness is, for example, 2.0 mm to 5.0 mm, and preferably 2.0 mm to 4.0 mm.

[0082] A low-E film (low emissivity film) (not shown) may be formed on the opposing surfaces of the third dielectric layer 6 and the second dielectric layer 3. The low-E film includes a tin oxide layer or an indium oxide layer, and a silver (Ag) layer.

[0083] Low-E films containing tin oxide or indium oxide layers have the advantage of being less susceptible to thermal degradation, but because they have a high inherent emissivity (normal emissivity εn of about 0.15 or higher), little improvement in thermal insulation or heat shielding properties can be expected, and heat shielding properties during a fire cannot be expected either. In other words, a significant improvement in fire protection performance cannot be expected.

[0084] On the other hand, Low-E films containing a silver layer have low emissivity (normal emissivity εn is approximately 0.1 or less) and excellent heat insulation and heat shielding properties, so as long as their emissivity is maintained even in the event of a fire, they can effectively prevent glass panels from breaking.

[0085] Therefore, it is preferable to use a low-E film containing a silver layer for the low-E film used as a heat-resistant low-E film. Since silver is easily oxidized by heating and its performance is easily deteriorated, a structure that can withstand heat, that is, a structure in which the silver is not easily deteriorated by heat, is preferable. For example, the following structures (A) and (B) can be mentioned.

[0086] (A) The Low-E film includes an oxide dielectric layer, a barrier layer, a silver layer, a barrier layer, and an oxide dielectric layer, in this order, and is formed directly on a glass plate. Each barrier layer is made of metal, and each barrier layer has a thickness of 2 nm or more. By interposing a barrier layer between the silver layer and the oxide dielectric layer, oxidation of silver can be suppressed, and deterioration of heat ray reflection performance can be suppressed. Furthermore, if each barrier layer is made of metal, and each barrier layer has a thickness of 2 nm or more, heat resistance is good. The metal constituting the barrier layer is, for example, a zinc alloy (Zn alloy) or titanium (Ti).

[0087] When a metal barrier layer is provided using a normal Low-E film, the thickness of the Zn alloy barrier layer is about 0.7 nm, and the thickness of the Ti barrier layer is about 1.5 nm.

[0088] The thicker the barrier layer (A), the better the heat resistance but the lower the permeability. The thickness of the barrier layer (A) is determined taking into consideration the heat resistance and permeability.

[0089] (B) The Low-E film includes a non-oxide dielectric layer, a barrier layer, a silver layer, a barrier layer, and a non-oxide dielectric layer, in this order, and is formed directly on the glass plate. By sandwiching the silver layer between the non-oxide dielectric layers, oxidation of the silver can be suppressed in high-temperature environments, ensuring high heat resistance while maintaining high heat ray reflection performance.

[0090] The barrier layer (B) is formed of a Zn alloy, Ti, or the like, similar to the barrier layer (A), thereby further improving heat resistance. The barrier layer (B) may be formed of the same material as the non-oxide dielectric layer.

[0091] The Low-E film may include multiple silver layers. Forming multiple silver layers can further reduce the emissivity and make εn significantly smaller than 0.1. For example, the Low-E film may include an oxide dielectric layer, a barrier layer, a silver layer, a barrier layer, an oxide dielectric layer, a barrier layer, a silver layer, a barrier layer, and an oxide dielectric layer, in this order, and is formed directly on the glass plate in this order. [Example]

[0092] The experimental data will be explained below: Examples 1 to 7 are comparative examples, and Examples 3 and 5 are working examples.

[0093] [Example 1] In Example 1, a laminate was fabricated by stacking a first dielectric layer, a first adhesive layer, a metal mesh fabric, a second adhesive layer, and a second dielectric layer in this order. Soda-lime glass plates measuring 600 mm in length, 600 mm in width, and 2.7 mm in thickness were prepared for the first dielectric layer and the second dielectric layer, respectively. A fiber sheet (manufactured by Asada Mesh, model number: 0500A00-00) made of stainless steel wire with a wire diameter of 50 μm was prepared for the metal mesh fabric. A TPU resin sheet (manufactured by Huntsman, product number PE399) was prepared for the first adhesive layer and the second adhesive layer, respectively.

[0094] Next, the laminate was placed in a vacuum bag, and the vacuum bag was air-baked with the pressure inside the vacuum bag reduced. The baking temperature was 85°C. Next, the laminate was removed from the vacuum bag and heated in an autoclave while being pressurized. The heating temperature was 100°C. As a result, the first adhesive layer and the second adhesive layer penetrated into the openings of the metal mesh fabric and were integrated, resulting in an electromagnetic wave shield.

[0095] [Example 2] In Example 2, an electromagnetic wave shield was produced under the same conditions as in Example 1, except that PVB resin sheets (manufactured by Sekisui Chemical Co., Ltd., product number RZRX) were prepared as the first adhesive layer and the second adhesive layer, respectively.

[0096] [Example 3] In Example 3, an electromagnetic wave shield was produced under the same conditions as in Example 1, except that a thermoplastic EVA resin sheet (manufactured by Tosoh-Nikkemi Co., Ltd., product number G7055) containing no organic peroxide or silane coupling agent was prepared as the first adhesive layer and the second adhesive layer, respectively.

[0097] [Example 4] In Example 4, an electromagnetic wave shield was produced under the same conditions as in Example 1, except that a thermosetting EVA resin sheet (manufactured by Bridgestone Corporation, product number EVASAFE) containing 0.04 mass% organic peroxide and no silane coupling agent was prepared as the first adhesive layer and the second adhesive layer, respectively.

[0098] [Example 5] In Example 5, an electromagnetic wave shield was produced under the same conditions as in Example 1, except that a thermoplastic resin sheet containing a hydrogenated block copolymer (manufactured by Nippon Zeon Co., Ltd., product number LS-XT) was prepared as the first adhesive layer and the second adhesive layer, respectively.

[0099] [Example 6] In Example 6, an electromagnetic wave shield was produced under the same conditions as in Example 1, except that a thermoplastic resin sheet containing a hydrogenated block copolymer (manufactured by Nippon Zeon Co., Ltd., product number LS) was prepared as the first adhesive layer and the second adhesive layer, respectively.

[0100] [Example 7] In Example 7, the same two glass plates and metal mesh fabric as in Example 1 were prepared, and an electromagnetic wave shielding body was produced by the method described in Patent Document 2. Specifically, the metal mesh fabric was placed on one glass plate, silicone resin (manufactured by Momentive, product number SN3001) was applied to the metal mesh fabric, and another glass plate was placed on top of that, and the silicone resin was heated and cured.

[0101] [evaluation] <Resin tensile modulus E' at 100°C> The tensile modulus E' of the resin at 100°C is the tensile storage modulus, and was determined from the stress-strain curve obtained by conducting a tensile test in accordance with JIS K7244-4:1999. The test piece for the tensile test had a width of 5 mm and a length of 20 mm. The tensile tester used was a DVA-200 model manufactured by IT Measurement & Control Co., Ltd. The tensile speed was 500 mm / min, the measurement frequency was 1 Hz, and the heating rate and temperature increase rate were 2°C / min.

[0102] <Water absorption rate of resin> The water absorption rate of the resin was measured in accordance with ASTM D570 (standard water absorption test method for plastics).

[0103] <Air bubbles during lamination> The presence or absence of air bubbles during lamination was checked by observing the intersections of the multiple metal wires that make up the metal mesh fabric immediately after the electromagnetic wave shielding body was produced.

[0104] <Heat and humidity resistance test> The heat and humidity resistance test of the electromagnetic wave shielding body was carried out using a thermo-humidistat chamber. The treatment conditions of the thermo-humidistat chamber were a temperature of 60°C, a humidity of 95%, and a time of 1000 hours. After treatment in the thermo-humidistat chamber, the electromagnetic wave shielding body was left in the air for one day, and then the presence or absence of any change in appearance was observed.

[0105] <Thermal cycle test> A thermal cycle test of the electromagnetic wave shielding material was also carried out using a thermo-hygrostat. The temperature of the thermo-hygrostat was kept at -20°C for 1 hour, raised from -20°C to 50°C over 2 hours, kept at 50°C for 1 hour, and lowered from 50°C to -20°C over 2 hours, which was repeated 48 times. After treatment in the thermo-hygrostat, the electromagnetic wave shielding material was left in the air for 1 day, and then observed for any changes in appearance.

[0106] <Summary> The evaluation results are summarized in Table 1.

[0107] [Table 1] In Table 1, "x" indicates that a change in appearance was visible to the naked eye from a distance of 3 m, and the problem of the present application could not be solved. "△" indicates that the change in appearance was not visible to the naked eye from a distance of 3 m, and was a better result than "x." "◯" indicates that no change in appearance occurred, and was the best result in solving the problem of the present application. Furthermore, in Table 1, "edge" indicates that the location where the appearance change was observed was the outer edge of the resin layer, and "interface" indicates that the location where the appearance change was observed was the interface between the metal wire and the resin and the interface between the resin and the glass plate. In Table 1, COP1 and COP2 refer to thermoplastic resins containing hydrogenated block copolymers.

[0108] In Examples 3 and 5, the resin of the resin layer was a thermoplastic EVA resin or a thermoplastic resin containing a hydrogenated block copolymer. The tensile modulus E' of the resin layer at 100°C was 5.0 × 10 5 The compressive strength was less than Pa. Therefore, it was possible to reduce the lamination temperature, improve the bubble releasing property of the resin layer, improve the workability of the lamination work, and suppress changes in appearance after lamination.

[0109] On the other hand, in Examples 1 to 6, the tensile modulus E' of the resin layer at 100°C was 5.0 × 10 5Since the pressure was above 100 Pa, the resin layer had poor defoaming properties, causing bubbles to form during lamination. In addition, in Examples 1 and 2, the resin used in the resin layer was a TPU resin or PVB resin with a water absorption rate of 0.1% or more, causing changes in appearance after lamination.

[0110] In addition, in Example 4, since the resin of the resin layer was a thermosetting EVA resin, a change in appearance occurred after lamination.

[0111] In Example 7, the resin of the resin layer was a silicone resin, which caused a change in appearance after lamination. Furthermore, in Example 7, the resin of the resin layer was a silicone resin, which made it impossible to laminate the resin layer in the form of a sheet, resulting in poor workability.

[0112] The electromagnetic wave shield according to the present disclosure has been described above, but the present disclosure is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure. The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2020-189668, filed on November 13, 2020, are hereby incorporated by reference as the disclosure of the specification of the present invention. [Explanation of symbols]

[0113] 1 Electromagnetic wave shield 2. First dielectric layer 3 Second dielectric layer 4 Resin layer 5. Metal mesh fabric

Claims

1. An electromagnetic wave shield that shields electromagnetic waves, a first dielectric layer, a second dielectric layer, a resin layer that bonds the first dielectric layer and the second dielectric layer, and a metal mesh fabric that is disposed on the resin layer; The metal mesh fabric has openings formed by metal wires that cross each other, the resin layer includes a thermoplastic resin containing a thermoplastic ethylene vinyl acetate (EVA) resin or a thermoplastic resin containing a hydrogenated block copolymer in which a portion of the unsaturated bonds of the block copolymer is hydrogenated; The thermoplastic EVA resin does not contain an organic peroxide or a silane coupling agent, the resin layer has a water absorption rate of less than 0.1% as measured in accordance with ASTM D570 (standard water absorption test method for plastics); The tensile modulus of the resin layer at 100°C is 5.0 x 10 ５ An electromagnetic wave shielding body having a tensile strength of less than 100 Pa.

2. The electromagnetic wave shield according to claim 1 , wherein the resin layer contains a thermoplastic resin containing the hydrogenated block copolymer.

3. 3. The electromagnetic wave shielding material according to claim 2, wherein the block copolymer comprises a polymer block whose main component is a repeating unit derived from an aromatic vinyl compound, and a polymer block whose main component is a repeating unit derived from a chain conjugated diene compound.

4. The electromagnetic wave shield according to claim 1 , wherein the resin layer contains the thermoplastic EVA resin.

5. An electromagnetic wave shield that shields electromagnetic waves, a first dielectric layer, a second dielectric layer, a resin layer that bonds the first dielectric layer and the second dielectric layer, and a metal mesh fabric that is disposed on the resin layer; The metal mesh fabric has openings formed by metal wires that cross each other, the resin layer has a water absorption rate of less than 0.1% as measured in accordance with ASTM D570 (standard water absorption test method for plastics); the resin layer has a tensile modulus of elasticity at 25°C of 10 kPa or more; The tensile modulus of the resin layer at 100°C is 5.0 x 10 ５ An electromagnetic wave shielding body having a tensile strength of less than 100 Pa.

6. 6. The electromagnetic wave shield according to claim 1, wherein the metal mesh fabric has metal wires with a diameter of 10 μm to 200 μm and an opening ratio of 50% to 90%.

7. 7. The electromagnetic wave shield according to claim 6, wherein the pitch of the metal wires in the metal mesh fabric is 50 μm to 1000 μm.

8. The electromagnetic wave shield according to any one of claims 1 to 7, which has a visible light transmittance of 30% or more.

9. 9. The electromagnetic wave shield according to claim 1, wherein the electromagnetic wave shielding rate is 40 dB or more when the frequency of the electromagnetic wave is 100 MHz to 1 GHz.

10. 10. The electromagnetic wave shield according to claim 1, wherein at least one of the first dielectric layer and the second dielectric layer is glass.

11. 11. The electromagnetic wave shield according to claim 1, wherein at least one of the first dielectric layer and the second dielectric layer is made of polycarbonate (PC) resin or acrylic resin.

12. a third dielectric layer disposed on the opposite side of the second dielectric layer from the first dielectric layer, and a conductive layer disposed between the second dielectric layer and the third dielectric layer, The electromagnetic wave shield according to any one of claims 1 to 11, wherein the conductive layer comprises a plurality of conductors and gaps that separate the plurality of conductors from one another, and the plurality of conductors are insulated from one another.

13. 12. The electromagnetic wave shield according to claim 1, further comprising: a third dielectric layer disposed on the opposite side of the second dielectric layer from the first dielectric layer; and an air layer disposed between the second dielectric layer and the third dielectric layer.

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