JP4545472B2 - Manufacturing method of laminated structure of electromagnetic wave absorber and electromagnetic wave absorber - Google Patents

Description

Manufacture of a laminated structure of a new wave absorber / electromagnetic wave absorber that can quickly and accurately produce a film or sheet-like structure by polymerizing a large number of absorbers that absorb radio waves and electromagnetic waves about the law.

  In general, radio wave absorbers are widely used for interiors, ceilings, roofs, walls, floors, and the like in order to prevent irregular reflection of radio waves from buildings and the like and to maintain a favorable wireless environment.

  And the radio wave absorbers such as these are composed of, for example, a first fiber coated with a metal and oxidized or magnetized, and an insulating second fiber not coated with the metal. What was comprised with the nonwoven fabric (refer below, patent document 1) and the flat soft magnetic metal powder which has an insulating film on the surface were formed in the predetermined thickness by being laminated | stacked in the thickness direction. 2. Description of the Related Art An electromagnetic wave absorbing sheet (refer to Patent Document 2 below) including a soft magnetic layer and an electrical insulating layer covering the surface of the soft magnetic layer is known.

Also known are sheet-like absorbers in which ferrite or metal that absorbs radio waves and electromagnetic waves is blended with rubber or the like.
Japanese Patent Laid-Open No. 9-331183 JP 2004-39703 A

  In these conventional techniques, even if a thin-layer radio wave and electromagnetic wave absorber is obtained, both are single bodies, and in order to obtain a radio wave absorber as a desired final laminated product, a coating means using an adhesive is used. Or when the absorber uses rubber, the uncrosslinked material is vulcanized by heat and the layers to be polymerized are fused.

  Therefore, it is difficult to maintain the thickness accuracy, the work time becomes long and inefficient, the continuous work is difficult, the cost is high, the efficiency is inferior, and the mass production is not possible at a low cost.

The present invention has been made paying attention to the above points, and uses a fixed thickness adhesive intermediate film interposed between a large number of laminated radio wave and electromagnetic wave absorbing materials in a heating manner. Another object of the present invention is to provide a method for producing a laminated structure of a radio wave absorber and an electromagnetic wave absorber that can be integrally bonded by pressing, heating, or pressing means.

  The present invention can be solved by the following configuration.

(1) A 0.3 mm or 0.6 mm thick radio wave absorbing material obtained by blending radio wave and electromagnetic wave absorbers is polymerized in four or more stages , and between adjacent layers of the radio wave absorbing material, 45 .mu. An intermediate adhesive film having a uniform thickness of 250 μm is interposed, and the resulting laminated structure material is placed in a manufacturing apparatus equipped with a heating and pressurizing device. First, the pressure is reduced to 30 torr or less for 2 minutes at room temperature. In addition to removing air outside the system, heating with reduced pressure, maintaining the temperature of the laminated structure material at 90 to 150 ° C., heating for 1 to 10 minutes, melting the intermediate adhesive film, and fixing them together A method for producing a laminated structure of a radio wave absorber and an electromagnetic wave absorber, which is obtained.
(2) A 0.3 mm or 0.6 mm thick radio wave absorbing material obtained by blending radio wave and electromagnetic wave absorbers is polymerized into four or more layers , and on either side, radio wave and electromagnetic wave reflective An intermediate adhesive film having a uniform thickness of 45μ to 250μ is interposed between adjacent layers of the electromagnetic wave absorbing material and between the substrates, and the resulting laminated structure material is heated. First, the pressure is reduced to 30 torr or less at room temperature for 2 minutes to remove the air outside the system and heat while maintaining the reduced pressure, and the temperature of the laminated structure material is 90 to 150. A method for producing a laminated structure of a radio wave absorber and an electromagnetic wave absorber, which is obtained by maintaining at a temperature of 1 ° C. and heating for 1 to 10 minutes to melt and fix the intermediate adhesive film integrally.

  According to the present invention, when a large number of radio wave absorbing materials are bonded together, a certain shape-retained intermediate adhesive film is used. Therefore, the work interposed between the radio wave absorbing materials is mechanically and efficiently performed. Compared to liquid adhesives, it can be bonded easily even if it has a vertical surface and downward angle, and the melt flow rate is particularly low, so that the intermediate adhesive film oozes out from the mating edge. Almost no occurrence and uniform thickness matching is possible.

  Furthermore, when the laminated intermediate adhesive film is based on a hot melt type polymer, it can be carried out in a desired state such as a tape or a film, and by using this laminated intermediate adhesive film, there is no blocking, and handling is easy. Moreover, it has many effects such as single operation and continuous work.

  Furthermore, according to the present invention, since the radio wave absorbing material that reflects radio waves is arranged in multiple layers, radio waves incident on the laminated structure are gradually absorbed and attenuated according to the degree of penetration, and strong electromagnetic waves penetrate. When the base is provided, a reflection effect in the reverse direction is also produced, and the effect of greatly enhancing the absorption of radio waves and electromagnetic waves can be obtained.

  Examples of the present invention will be described below.

  The embodiment of the present invention will be described with reference to the cross-sectional explanatory view of FIG.

  The illustration shows an enlarged view of the laminated structure. 1, 1, 2 and 2 are two types of thin films that are pre-formed into a film shape by compounding chemical substances that absorb radio waves and electromagnetic waves polymerized in multiple stages. An electromagnetic wave absorbing material 3 is a metal material corresponding to the base of the lowermost layer. That is, the upper two wave absorbing materials 1 and 1 have a thickness of 0.30 mm, the lower wave absorbing materials 2 and 2 have a thickness of 0.60 mm, and the base 3 has a thickness of 2 mm. An intermediate adhesive film 4 having a thickness of 20 to 250 μm can be interposed between the equal wave absorbing materials 1, 2, 2, and the substrate 3.

  Thus, the laminated structure material in which the intermediate adhesive film 4 is interposed in the radio wave absorbing materials 1, 1, 2 and 2 and the substrate 3 is disposed in a manufacturing facility equipped with a heating and pressurizing device. Hold at reduced pressure (less than 30 torr) for 2 minutes to remove outside air and apply a constant pressure.

  Next, heating is performed under reduced pressure, the temperature of the laminated structure material is maintained at 90 to 150 ° C., heating is performed for 1 to 10 minutes, the intermediate adhesive film 4 is melted, and the prepared radio wave absorbing materials 1, 1, 2, 2 and The base 3 can be fixed integrally.

  By the way, the radio wave absorbing material is not limited to the above-described configuration and number, and any polymer material such as rubber or plastic polymer can be used, and metals such as ferrite and iron that can absorb and reflect radio waves and electromagnetic waves can be used. You can freely select and use the powder.

  The above shows an example of forming a sheet, but in the case of a long sheet, it is continuously heated and pressurized from the respective radio wave absorbing materials wound in a roll, the intermediate adhesive film, and the substrate. The same can be carried out.

  Further, as the composition constituting the intermediate adhesive film, for example, a combination of petroleum wax as a hot melt adhesive and petroleum adhesive such as low molecular weight polystyrene, atactic polypropylene, rosin and pentene resin is used. Specifically, for example, the following hot-melt type plastic polymers can be considered. The strength can be freely adjusted by changing the thickness.

なお、必要に応じて基盤３は硬質のゴム，プラスチックの外、Ｆｅ，Ａｌ，Ｚｎ，Ｓｎ，Ｃｕ，ステンレスなどの電波・電磁波反射性の良い金属にも応用できる。

If necessary, the substrate 3 can be applied not only to hard rubber and plastic but also to metals having good radio wave and electromagnetic wave reflectivity such as Fe, Al, Zn, Sn, Cu, and stainless steel.

  Table 1 and Table 2 show the thickness accuracy and adhesive strength according to the type, thickness, temperature, pressure, and time of the intermediate adhesive film 4 shown in FIG.

  According to the present invention, since highly efficient laminating adhesion is performed using an intermediate adhesive film, a large number of thin wave absorbers are polymerized to reflect and absorb extremely highly absorbing radio wave absorbers and electromagnetic wave absorbers. A structure can be provided at low cost with high productivity and high accuracy.

Expanded cross-sectional explanatory view of a laminated structure showing a manufacturing process of a laminated structure of radio wave absorber and electromagnetic wave absorber according to the present invention

Explanation of symbols

1, 1, 2, 2 Electromagnetic wave absorbing material 3 Base 4 Intermediate adhesive film

Claims (2)

A 0.3 mm or 0.6 mm thick wave absorbing material obtained by blending an electromagnetic wave and electromagnetic wave absorber is polymerized into four or more layers, and uniform between 45 μm and 250 μm between adjacent layers of such wave absorbing materials. An intermediate adhesive film having an appropriate thickness is interposed, and the resulting laminated structure material is placed in a manufacturing apparatus equipped with a heating and pressurizing device. First, the pressure is reduced to 30 torr or less at room temperature for 2 minutes, It can be obtained by removing the air and heating under reduced pressure, maintaining the temperature of the laminated structure material at 90 to 150 ° C., heating for 1 to 10 minutes, melting the intermediate adhesive film, and fixing them together. Manufacturing method of laminated structure of radio wave absorber and electromagnetic wave absorber characterized by A 0.3 mm or 0.6 mm thick radio wave absorbing material obtained by blending a radio wave and electromagnetic wave absorber is polymerized into four or more layers , and a metal having radio wave and electromagnetic wave reflectivity is formed on either side. An intermediate adhesive film having a uniform thickness of 45 μ to 250 μ is interposed between adjacent layers of the electromagnetic wave absorbing material and between the substrates, and the resulting laminated material is provided with a heating and pressing device. First, the pressure is reduced to 30 torr or lower for 2 minutes at room temperature to remove air outside the system and heat the vacuum while maintaining the temperature of the laminated structure material at 90 to 150 ° C. And a method of producing a laminated structure of a radio wave absorber and an electromagnetic wave absorber, which is obtained by heating for 1 to 10 minutes, melting the intermediate adhesive film, and integrally fixing.

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