JP2000133980A - Electromagnetic shielding gasket and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasket composed of a flexible core and a conductive covering material which is as soft as the core and covers the core and a manufacturing method thereof. SOLUTION: A conductive porous sheathing material 12 which is manufactured through a manner where a metal plating layer is formed on the outer and inner surface of a continuously foamed elastic resin body respectively and an elastic porous core 10 sheathed with the sheathing material 12 are prepared, adhesive agent is applied onto the one surface of the sheathing material 12, then the elastic porous core 10 is sheathed with the sheathing material 12, and the core material 10 and the sheathing material 12 are bonded together through the intermediary of the adhesive agent for the manufacture of an electromagnetic shielding gasket 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gasket for shielding electromagnetic waves and a method for manufacturing the same.

[0002]

2. Description of the Related Art OA of computers, word processors, etc.
Devices and other various electronic devices incorporating a microcomputer as a control element are liable to malfunction due to disturbance such as electromagnetic waves entering the device from the outside. In order to protect the OA equipment and the like from interference of this kind of electromagnetic wave (EMI) and interference of lower frequency radio waves (RFI), a shield (shield) is generally applied to the equipment housing.

[0003] This electromagnetic wave shielding is performed by, for example, applying a conductive paint to the inside of a housing that forms a housing of a computer, or covering a central processing unit (CPU) with a metal plate or a wire mesh. By the way, as an example, since the housing of the computer has a divided structure generally composed of a plurality of parts, a slight gap generated when these coppers are combined, a connector for a cord for connecting various modules, and the like. It is known that an electromagnetic wave intrudes from a gap inevitably generated at a place where a terminal or the like is installed, thereby causing a malfunction of the device. For this reason, by sticking a soft conductive member, for example, in the form of a sheet, at a location along the parting line in the housing or at an installation site of a connector terminal or the like, it is possible to prevent electromagnetic waves from entering the housing. Technology has been implemented. Since the conductive member fills a gap or the like of a division line when a plurality of patterns formed by the housing are combined, the conductive member is generally called a gasket in view of its function. Therefore, this term is used in this application.

As this type of technology, a core material is formed by forming a foamed material having elasticity such as polyurethane foam into a column shape, and a gasket in which the core material is covered with a woven cloth of conductive fiber, a conductive material, or the like. US Pat. No. 4,857,6 discloses a gasket in which the periphery of the core material is covered with a conductive cloth material provided with conductivity by applying wet or dry metal plating to a conductive cloth material.
No. 68 is disclosed. Japanese Patent Application Laid-Open No. 2-296396 discloses an electromagnetic wave shielding gasket in which an elastomer core is surrounded by a conductive wire mesh instead of using a conductive fiber or a conductive cloth.

[0005]

The above-mentioned gasket for shielding electromagnetic waves is provided along the dividing line of the housing or in a mounting opening of a connector terminal or the like so as to prevent the invasion of electromagnetic waves from the outside. This is extremely effective in that it can be performed. However, the conductive fibers, conductive cloths and other conductive wire meshes that form part of these gaskets lack material flexibility and are considerably more rigid than the polyurethane foam used as the core material. Has become. For this reason, there is no problem if the dividing line in the housing (which has been subjected to conductive treatment by applying a conductive paint or resin molding of a conductive powder) is straight, but the dividing line forms small irregularities in places. When the gasket is provided, the conductive fibers and the wire mesh are difficult to follow the shape change when the gasket is disposed, and the wrinkles are wrinkled when the gasket is provided. As a result, it was impossible to completely fill the gap, and there was a serious drawback that electromagnetic waves could enter from outside through the gap.

[0006]

SUMMARY OF THE INVENTION According to the present invention, the conventional gasket for shielding electromagnetic waves lacks structural flexibility as a whole.
For this reason, it has been proposed to preferably solve the problem that the shape following ability was inferior depending on a portion to be disposed, and a conductive covering material for covering a flexible core material is also flexible. It is an object of the present invention to provide a gasket and a method for manufacturing the gasket.

[0007]

Means for Solving the Problems In order to overcome the above-mentioned problems and achieve the intended object, an electromagnetic shielding gasket according to the present invention comprises a porous core material having elasticity, and this core material being provided from outside. A coating of a conductive porous body having elasticity for coating, the coating comprising an open-celled elastic resin body, and a metal plating layer formed on the outer and inner surfaces of the elastic resin body. It is characterized by having.

In another aspect of the present invention, a method of manufacturing a gasket for electromagnetic wave shielding which can overcome the above-mentioned problems is provided by forming a metal plating layer on an outer surface and an inner surface of an elastic resin body having open cells. A coating material for the manufactured conductive porous body and a core material for the porous body having elasticity to be wrapped by the coating material are prepared, and an adhesive is applied to one surface of the coating material for the conductive porous body. After the application, the core material of the porous body having elasticity is wrapped with the coating material from the outside, and the core material and the coating material are joined via the adhesive to produce a gasket for electromagnetic wave shielding. It is characterized by the following.

[0009] Still another invention of the present application, which is a method of manufacturing an electromagnetic wave shielding gasket which can also overcome the above-mentioned problems, comprises forming a metal plating layer on an outer surface and an inner surface of an elastic resin body having open cells. To produce a coating material of a conductive porous body, and inject a two-component foamed resin material into one surface of the coating material of the conductive porous body, and form the coating material into a tube while foaming the resin material. Involving in the shape
The present invention is characterized in that a gasket for electromagnetic wave shielding is manufactured using a porous material having elasticity generated by the foaming reaction as a core material.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a gasket for electromagnetic wave shielding according to the present invention has a core material 10 of a porous material having elasticity and a conductive porous material for covering the core material 10 from the outside. And body covering material 12. And covering material 1
No. 2 is based on the invention "conductive porous body" which has been previously filed by the present applicant as Japanese Patent Application No. 10-114300 and has not been disclosed at the present time. And a metal plating layer formed on the outer and inner surfaces of the elastic resin body. That is, as the core material 10, for example, a porous body having elasticity such as urethane foam is used. As the coating material 12 of the core material 10, for example, a multilayer of a copper plating layer and a nickel plating layer on the inner and outer surfaces of the urethane foam is used. What gave conductivity by giving metal plating etc. is used. The coating material 12 is made of an elastic porous material like the core material 10, and the metal plating layer applied thereto does not impair the flexibility of the porous material. 1
2 for shielding electromagnetic wave obtained by coating 2
Also has the same degree of flexibility as the core material 10 as a whole.

First, the elastic porous body constituting the core material 10 is preferably a soft urethane foam, which is obtained by mixing an isocyanate component, a polyol component and water, as in a so-called foamed polyurethane foam. It is suitably manufactured by a chemical reaction of manufacturing a foam using carbon dioxide generated by the reaction between the components and water. Further, the physical properties thereof are preferably, for example, in the following ranges. (1) Density: 20 to 100 kg / m ³ (2) Number of cells: 30 to 100 / inch (3) Tensile strength: 1.0 to 2.0 kg / cm ² (4) Elongation: 40 to 250% (5 ) Rebound resilience; 30 to 65% In addition to urethane foam, the material may be appropriately selected from elastic porous materials such as rubber sponge and foam rubber.

Next, since the conductive porous body having elasticity serving as the coating material 12 is composed of an elastic resin body having open cells and a metal plating layer formed on the outer and inner surfaces of the resin body. The details will be described. The material constituting the open-cell elastic resin body may be any material having open-cell elasticity, and may be an elastomer, another rubber, or another resin exhibiting elasticity (in the present invention, all of these materials are used). Is included in the category of “elastic resin”). Among them, soft urethane foam or silicone rubber is preferable, and other than the above, semi-rigid polyurethane foam, polyurea foam, melamine / formaldehyde resin foam, urea / formaldehyde resin foam or the like can also be used. As this soft urethane foam, for example, a soft urethane slab foam formed into a sheet shape is used. The physical properties suitable for the open-cell elastic resin body used for the covering material 12 are substantially the same as those of the porous body used for the core material 10 described above. However, processing into a sheet shape, formation of a metal plating layer, and From the viewpoint of ensuring electromagnetic shielding properties, it is desirable to have greater mechanical strength and a large surface area with a large number of cells. In this respect, ether polyol foams or ester polyol foams, especially the latter, are preferred. The physical properties of the urethane foam are preferably in the following ranges. (1) Density: 20 to 100 (preferably 20 to 60) kg /
m ³ (2) Number of cells: 5 to 100 (preferably 30 to 80) cells / i
nch (3) Tensile strength: 1.0 to 3.0 (preferably 1.5 to 2.0)
5) kg / cm ² (4) Elongation; 150 to 500 (preferably 200 to 350)
% (5) Rebound resilience; 30 to 65%

Further, when using foamed polyurethane,
It is preferable to remove the cell film from this. As a method of removing the cell membrane, for example, a method of obtaining a foam that has been broken by adjusting the raw material composition, a known dissolving method, a hydrogen explosion method, or the like is used. In order to adjust the blending, a method is employed in which a polyether polyol and a polyester polyol are used in combination, and a surfactant is further adjusted to increase the porosity of the foam to a blended formulation. Here, the dissolution method
This is an alkali dissolution method in which a foam is immersed in a concentrated alkali solution to hydrolyze ester bonding groups to remove a cell membrane. Further, the hydrogen explosion method refers to a method in which a combustible substance such as natural gas, hydrogen gas or acetylene and oxygen are mixed and ignited within an explosion limit to explode, and the cell membrane is removed by the impact.

The metal plating layer applied to the open-cell elastic resin body is not particularly limited in the type of metal, but is usually nickel, copper or the like. The thickness of the metal plating layer is not particularly limited, and a resistance value and a degree of elasticity (including an elastic body or an inelastic body) depending on the purpose or application are selectively used. That is, if a low resistance is intended, a relatively thick plating layer (for example, 0.1 μm or more, preferably 0.1 μm or more) is used.
5μm or more) and a thin plating layer for high resistance
(For example, 0.02 μm or less, preferably 0.01 μm or less), and a relatively thin plating layer (for example, 0.3 μm or less, preferably 0.2 μm or less) for an elastic body. For the purpose, a relatively thick plating layer (for example, 0.3 μm or more, preferably 0.4 μm or more) is used.

In order to form the metal plating layer, an anionic surfactant is preferably used, which is a soap such as a sodium carboxylate or a potassium fatty acid, wherein the fatty acid contains C _{12 to} C ₁₈ lauric acid, myristic acid, palmitic acid, stearic acid or oleic acid. Alkyl sulfonates are preferred among the sulfonates, and sulfonated sodium ricinoleate is particularly preferred from the viewpoint of foam stability of the ester polyurethane foam. This foam stabilizer is effective for the production of ester foam, and in order to obtain a foam having a better cell structure, a foam comprising sodium sulfonated sodium ricinoleate and an ester polyol is more preferable. For ether foam,
By reducing the amount of the silicone-based surfactant to about one half of the conventional amount and adding an anionic surfactant in an increased amount to adjust the foam stabilizer, an ether foam having predetermined physical properties can be obtained.

In order to apply a metal plating layer to the elastic resin body, preferably, a cationic surfactant is used as a plating surface conditioner. As the surfactant, an aliphatic amine salt or an aliphatic quaternary ammonium salt can be used, and specifically, a compound represented by the following chemical formula (first,
Secondary, tertiary or quaternary amine salts). Chemical formula (R
1) (R2) (R3) -N.X (R1, R2, R3 are those having 12 carbon atoms)
And X is an inorganic or organic acid. Organic acids include acetic acid, carboxylic acid, lactic acid or citric acid. Inorganic acids include hydrochloric acid or sulfuric acid.
However, the case where all of R1, R2, R3 and X are H is excluded. )

The relationship between the anionic surfactant added to the polyurethane foam or the like and the surface conditioner for plating will be described below. As a raw material of the polyurethane foam, a polyol component and an isocyanate component are used as main components, and auxiliaries such as a catalyst and a foaming agent are added thereto. This auxiliary is usually added to the polyol, where the surfactant is also added. The surfactant has an effect of stabilizing the foam of the foam by the action of mixing and uniformly dispersing the auxiliary agent and the main component, and obtaining a uniform cell structure. Normally, a foam stabilizer contributing to the dispersing action remains on at least the surface (surface portion) of the cell membrane or skeleton of the foamed polyurethane foam. In this embodiment, the surface of the cell membrane or skeleton is negatively charged by using an anionic surfactant as a foam stabilizer for the polyurethane foam. When an anionic surfactant is not used, it is considered that the zeta potential on the surface of the foamed polyurethane is mainly positive (or neutral).

Next, a primer treatment is performed to plate the foam. That is, in order to enhance the permeability of the plating catalyst and the adsorption of the plating metal, this is a treatment of immersion in a surface conditioner. At this time, the cell film or skeleton, which is the plating surface, must be sufficiently wet by the surface conditioner. Here, by using a cationic surfactant as the surface conditioner, the cell membrane or the skeleton surface shows an action of attracting the negative charge charged to the surface of the skeleton and the cell membrane or the skeleton surface sufficiently. You will be wet. Next, the catalyst is applied by immersing the polyurethane foam in the plating catalyst solution. Normal,
Since the plating catalyst is negatively charged, it is uniformly adsorbed on the plating surface adjusted by the surface conditioner by an electric suction force. The same applies to elastic resins other than foamed polyurethane when the surface potential is neutral or positive. Thus, a conductive porous body made of polyurethane or the like in which the metal plating layer is uniformly applied to the outer surface and the inner surface is obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a gasket for electromagnetic wave shielding and a method of manufacturing the same according to the present invention will be described in detail with reference to specific examples. (1) Production of conductive porous body A polyurethane foam was produced using an anionic surfactant (sulfonated sodium ricinoleate) without using a silicone-based surfactant. That is, the following liquids A and B were adjusted so that the isocyanate index became 110, and injection foaming was performed with a low-pressure injection machine to obtain a slab. [A liquid (polyol component)]: (1) Polyol (trade name: F21-79T, manufactured by Asahi Glass Co., Ltd.) (molecular weight: 2200, OHV: 60, polyester polyol) ... 100 parts by weight (2) Blowing agent : Tap water 4.0 parts by weight (3) Foam stabilizer: sulfonated sodium ricinoleate 0.5 parts by weight (4) Amine catalyst: (trade name LV33, manufactured by Nippon Emulsifier Co., Ltd.) 0.3 parts by weight (5) Resin conversion catalyst: (trade name: STANAZ octoate manufactured by Chukyo Yushi Co., Ltd.) 0.3 parts by weight The above components are mixed to prepare a polyol component. did. [Liquid B (isocyanate component)]: polyisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name: Millionate MTL)

Further, the cell film was removed by the following method.
That is, the above foam slab cut into a rectangular parallelepiped is placed in a box-shaped closed container provided with a spark gap terminal and a gas injection hole in the lid of the container. Hydrogen: oxygen molar ratio 2:
Fill until the concentration of the military is 1 at the rate of 1. After closing the injection hole, a spark discharge was generated between the terminals to explode, thereby removing the cell film. The obtained foam is dried at room temperature because it contains moisture. Next, it was processed into a sheet shape (flat plate shape, 100 × 100 × 10 mm).

The physical properties of the polyurethane foam are as follows. (1) Density: 30 to 32 kg / m ³ (2) Number of cells: 65 cells / inch (3) Tensile strength: 2.2 to 2.3 kg / cm ² (4) Elongation: about 400%

After that, this was added to a plastic plating surface conditioner (conditioner K, trade name, manufactured by Okuno Pharmaceutical Co., Ltd.) 50 m
Immerse in l / l for 5 minutes at room temperature. Thereafter, the excess liquid is squeezed sufficiently with a roller or the like, and then rinsed twice with water.
Further, 200 ml of a 35% hydrochloric acid solution containing 30 ml / l of a palladium tin catalyst (trade name: Catalyst C, manufactured by Okuno Pharmaceutical Co., Ltd.)
/ l for 5 minutes at room temperature. Next, they are washed with water, then immersed in 96% sulfuric acid 100 ml / l at room temperature for 5 minutes, and then washed with water. This was immersed in an electroless nickel solution (trade name: TMP Chemical Nickel HR-T, manufactured by Okuno Pharmaceutical Co., Ltd., 150 ml / l for both A solution and B wave) at 40 ° C. for 1 minute, and further washed with water and dried.

As described above, the metal plating layer is formed on the inner surface and the outer peripheral surface of the polyurethane foam. The thickness of the plating layer was 0.06 μm, and the resistance value was 40Ω. Further, it was found that the flexibility was not changed in any of 30 ° C. and 15 ° C., and that the flexibility was not impaired even at 15 ° C. The results are shown in Table 1.

The plating film thickness was measured by observing a cross section of the urethane skeleton by SEM. The resistance value was measured using a resistance tester using a Lorester FP manufactured by Yuka Denshi Co., Ltd., a four-terminal method separate probe. This resistance is between the opposing faces of the 1 cm ³ sample. This flexibility was determined to be flexible by compressing the foam layer to a thickness of 50% with the elastic foam layer attached to the shaft and confirming that the foam layer recovered to its original thickness and did not buckle. did.

(2) Examination of plating film thickness Various plating film thicknesses were formed on a polyurethane foam (ester urethane having 65 cells, from which the cell film was removed), and the plating film thickness and the resistance value or flexibility were measured. The relationship with was examined. 5 "Conditioner K" as a surface conditioner
It was immersed in a solution consisting of 0 ml / l and 100 ml / l of “Contilizer FR” (all manufactured by Okuno Pharmaceutical) at 25 ° C. for 5 minutes. After that, it was thoroughly washed with water, and a palladium-tin catalyst (catalyst C, manufactured by Okuno Pharmaceutical Co., Ltd.) 30 ml / l
And 200 ml / l of concentrated hydrochloric acid at 25 ° C. for 5 minutes. Further, wash with water sufficiently and add 96% sulfuric acid 10
It was immersed in 0 ml / l at 25 ° C for 5 minutes.

Then, wash thoroughly with water and electroless copper plating
(Product name Omni Shield 1 manufactured by Shipley Far East
598) (copper ion concentration; 2 g / l, 45
° C) for the time shown in Table 1 below. Further, it was washed with water and immersed in a bath (nickel ion concentration: 3.6 g / l, 35 ° C.) having a standard composition of electroless nickel plating (trade name: Omnishield 1580, manufactured by Shipley Far East) for 1 minute.
Washed and dried. As described above, various plating film thicknesses were formed (see Table 1). The plating film thickness, resistance value and flexibility of the conductive sheet-shaped material were measured by the method described above,
The results are shown in Table 1.

Table 1 ─────────────────────────────────── Plating time (min) Plating film thickness (μm ) Resistance value (Ω) Flexibility １1 0.01 or less 2 × 10 ⁶ or more Yes 2 0.06 40 Yes 3 0.106 Yes 5 0.16 0.07 Yes 7 0.21 0.03 Slightly hard, compressive deformation Strain recovery is somewhat poor. 10 0.35 0.02 Deformation irrecoverable due to compression. ───────────────────────────────────

As described above, the plating film thickness or the resistance value can be appropriately changed by adjusting the immersion time. That is,
When the immersion time is 7 minutes or less, the film thickness can be 0.21 μm or less. In this case, the film thickness is thin, so that the flexibility is excellent. Further, by changing the film thickness in the range of 0.21 to 0.01 μm or less, the resistance value can be freely changed in the range of 0.03 to 2 × 10 ⁶ Ω. Therefore, the desired resistance value, that is, low resistance (0.01 Ω) is maintained while maintaining flexibility.
) To an intermediate resistance value of about 10 ³ Ω to 10 ⁶ Ω, and a conductive porous body having a predetermined low resistance value (or even higher resistance value) can be manufactured. In particular, a material excellent in low resistance (50Ω or less or 10Ω or less) and elasticity suitable for an electromagnetic wave shielding material could be easily manufactured.

The core material 10 is appropriately obtained from, for example, urethane foam, rubber sponge, foam rubber, or the like. In this embodiment, a core-shaped material made of foamed polyurethane is used. The core material 10 was covered with the conductive porous material covering material 12 obtained in the above-described process, thereby obtaining an electromagnetic wave shielding gasket 14 as a product. As a method of manufacturing the gasket 14, as shown in FIG. 2, the core material 10 and the coating material 12 are prepared in advance, the core material 10 is wrapped with the coating material 12, and the two materials are joined via an adhesive. As shown in FIG. 3, there is a means for injecting a two-component foamed resin material into the covering material 12 and winding it into a cylindrical shape, thereby forming a foamed core material 10 therein.

[0030]

[Manufacturing means 1] A means for preparing the core material 10 and the covering material 12 in advance, wrapping the core material 10 with the covering material 12 and joining the two materials via an adhesive to produce a gasket for electromagnetic wave shielding. This will be described below with reference to FIG. As the open-cell elastic resin body constituting the coating material 12, a polyurethane foam subjected to a cell membrane removal treatment is used.
(Product name MF manufactured by INOAC CORPORATION
-65) was used. The physical properties of this product "MF-65" are as follows. (1) Density: 57 kg / m ³ (2) Number of cells: 65 cells / inch (3) Tensile strength: 1.5 kg / cm ² (4) Elongation: 200% This product “MF-65” is 1 mm thick, The sheet was processed into a sheet shape having dimensions of 40 mm in width and 300 mm in length.
Then, the above-mentioned conditioner, catalyst and accelerator treatment are applied to the open-cell elastic resin body, and electroless copper plating and electroless nickel plating are deposited on the foam skeleton by 0.5 μm and 0.1 μm, respectively. After that, it was washed and dried to obtain a coating material 12.

As the core material 10, a polyurethane foam (trade name, manufactured by INOAC CORPORATION)
CF-50) processed into a size of 8 mm square and 300 mm in length was used. The physical properties of this product "CF-50" are as follows. (1) Density: 30 kg / m ³ (2) Number of cells: 45 cells / inch (3) Tensile strength: 1.8 kg / cm ² (4) Elongation: 100%

Then, as shown in FIG.
2, an acrylic emulsion pressure-sensitive adhesive (trade name: TS-153, manufactured by Nippon Carbide Industry) was used as the adhesive 20.
7) is applied under the condition of a dry thickness of 20 g / m ² to form an adhesive layer, and as shown in FIG.
And cover material 12 so as to cover around core material 10.
Was bonded and integrated to produce a gasket 14 for shielding electromagnetic waves. At this time, the electromagnetic shielding gasket 1
4 is straightened by using a predetermined jig.
Was fixed while fixing. The adhesive for bonding and integrating the core material 10 and the coating material 12 is, for example, a synthetic rubber-based one-component solvent-evaporating type that can maintain flexibility so as to become a low-hardness elastomer after curing. Is preferably used, and in addition to the above-mentioned product "TS-1537", for example, "Chemedyne Co., Ltd. product name Bond G" and the like can be mentioned.

[0033]

[Manufacturing means 2] The means for manufacturing a gasket for electromagnetic wave shielding by injecting a two-component foamed resin material into the covering material 12 shown in FIG. The coating material 12 plated with metal in the same manner as in the above-mentioned manufacturing method 1 is used.
It was formed into an outer shape required as the electromagnetic shielding gasket 14. As shown in FIG. 3 (a), the following two raw materials to be the core material 10 inside the core material are adjusted so that the isocyanate index becomes 105: A component; polyol component and B component; Then, the mixture was poured and foamed to form a core material 10 in order. The raw material used here is preferably a composition that can be foamed and cured by discharging a small amount. [Liquid A (polyol component)]: (1) Polyether polyol (molecular weight: 3000, number of functional groups: 3, primary hydroxyl group content: 40%) 100 parts by weight (2) Blowing agent: tap water 5.0 parts by weight (3) Foam stabilizer : Silicone foam stabilizer (trade name: SF2964, manufactured by Toray Dow) 0.5 parts by weight (4) Amine catalyst: triethylenediamine (manufactured by Toyo Soda Kogyo Co., Ltd.) 1 part by weight (5) Crosslinking agent: diethylene glycol 15 parts by weight The ingredients were adjusted. [Liquid B (isocyanate component)]: Crude MDI (Nippon Polyurethane Co., Ltd., product name: Silionate MR200)

Then, as shown in FIG.
From the place where the two-component raw material to be injected had been injected, a procedure was carried out in which the covering material 12 was surrounded to form a gasket for electromagnetic shielding in order. The core material 10 is a closed covering material 1
2 sequentially foamed inside, thereby gradually growing along the coating material 12. At this time, since the core material 10 during foaming has a high viscosity, the core material 10 also functions as an adhesive to the coating material 12.

As a result of measuring the electromagnetic wave shielding effect of the gasket for electromagnetic wave shielding manufactured by these manufacturing means by the KEC method, both of them were measured at 70 MHz at 500 MHz.
A numerical value as high as dB or more was obtained. Further, the gasket for electromagnetic wave shielding according to the present invention can be used in an anechoic chamber,
It can also be used for building materials in places where it is necessary to prevent intrusion and leakage of various electromagnetic waves, such as rooms where medical equipment is installed.

[0036]

As described above, according to the gasket for electromagnetic wave shielding according to the present invention, not only the core material has sufficient flexibility, but also the covering material having the conductive function has the same degree. Because it has flexibility, it can exhibit high shape following ability, for example, irregular shapes that can occur there from small things such as OA equipment to large things like building materials, and various shapes that curve with a small curvature It is easy to arrange them in close contact with each other, and therefore, there is an advantage that intrusion of electromagnetic waves can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a preferred electromagnetic wave shielding gasket according to the present invention.

FIG. 2 is a manufacturing process diagram showing a first manufacturing means according to the present invention.

FIG. 3 is a manufacturing process diagram showing a second manufacturing means according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Core material 12 Coating agent 14 Gasket for electromagnetic wave shielding 20 Adhesive

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B32B 15/08 B32B 15/08 EK C23C 18/38 C23C 18/38 18/52 18/52 B // C09K 3/10 C09K 3/10 RF terms (reference) 4H017 AA03 AA23 AA31 AA39 AB03 AB04 AB06 AC10 AC13 AE04 AE05 4K022 AA13 AA37 AA41 BA08 BA14 BA36 CA05 CA06 CA07 CA15 CA18 CA21 DA01 DB04 DB07 DB08 EA02 5E321 BB02 EA02 5E321 A03 BB02 GG05

Claims (11)

[Claims] 1. A core material (10) of a porous body having elasticity, and a coating material (12) of a conductive porous body having elasticity for covering the core material (10) from the outside. The material (12) is a gasket for electromagnetic wave shielding, comprising: an open-cell elastic resin body; and metal plating layers formed on the outer surface and the inner surface of the elastic resin body. 2. The gasket for an electromagnetic wave shield according to claim 1, wherein the elastic porous body constituting the core material (10) is appropriately selected from urethane foam, rubber sponge, and foam rubber. 3. The gasket for electromagnetic wave shielding according to claim 1, wherein the open-cell elastic resin body constituting a part of the coating material (12) is made of foamed polyurethane from which a cell membrane has been removed. 4. The open-cell elastic resin body constituting a part of the coating material (12) may be, for example, urethane foam, polyurethane-urea foam, polyurea foam, melamine-formaldehyde resin foam, urea-formaldehyde resin foam. 2. The gasket for an electromagnetic wave shield according to claim 1, which is appropriately selected from the group. 5. The electromagnetic wave according to claim 1, wherein the open-cell elastic resin body constituting a part of the coating material (12) is formed by foaming an anionic surfactant as a foam stabilizer. Gasket for shielding. 6. The electromagnetic wave shielding gasket according to claim 1, wherein the metal plating layer constituting a part of the coating material (12) is formed by using a cationic surfactant as a surface conditioner. 7. The metal plating layer constituting a part of the coating material (12) has a multilayer structure of an electroless copper plating layer and an electroless copper nickel plating layer. Gasket for electromagnetic wave shielding. 8. A coating material (12) of a conductive porous body manufactured by forming a metal plating layer on an outer surface and an inner surface of an elastic resin body having open cells, and wrapped by the coating material (12). Prepare a porous core material (10) having elasticity to be provided, apply an adhesive (20) to one surface of the conductive porous material covering material (12), and then provide the elastic material. A core material (10) of a porous body is wrapped from the outside with the coating material (12), and the core material (10) and the coating material (12) via the adhesive (20).
And gasket for electromagnetic shielding (14)
A method of manufacturing a gasket for electromagnetic wave shielding, characterized by manufacturing a gasket. 9. The method according to claim 8, wherein a synthetic rubber-based adhesive is suitably used as the adhesive. 10. A coating material (12) for a conductive porous body is produced by forming a metal plating layer on the outer surface and the inner surface of an elastic resin body having open cell properties, and coating the conductive porous body. Lumber
The two-component foamed resin material is injected into one surface of (12), and the coating material (12) is rolled up in a tubular shape while foaming the resin material. A method of manufacturing a gasket for electromagnetic wave shielding, comprising manufacturing a gasket for electromagnetic wave shielding (14) using a base material as a core material (10). 11. The method for producing a gasket for electromagnetic wave shielding according to claim 10, wherein a polyol component and an isocyanate component are preferably used as said two-component foamed resin raw material.