JPH09275295A - Radio wave absorbent - Google Patents
Radio wave absorbentInfo
- Publication number
- JPH09275295A JPH09275295A JP8422396A JP8422396A JPH09275295A JP H09275295 A JPH09275295 A JP H09275295A JP 8422396 A JP8422396 A JP 8422396A JP 8422396 A JP8422396 A JP 8422396A JP H09275295 A JPH09275295 A JP H09275295A
- Authority
- JP
- Japan
- Prior art keywords
- radio wave
- wave absorber
- carbon particles
- electromagnetic wave
- ceramic fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Laminated Bodies (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、耐火性に優れた電
波吸収体に関する。TECHNICAL FIELD The present invention relates to a radio wave absorber having excellent fire resistance.
【０００２】[0002]
【従来の技術】電波吸収体は、電子装置を評価するため
の電波暗室の壁面や、電波障害の対策等に使用されてい
る。従来の電波吸収体は、発泡ウレタンや発泡スチレン
等の母材に、カーボン等の導電性材料を含浸、練り混
み、吹き付け、メッキ等の手法で付着させたものであ
る。2. Description of the Related Art Electromagnetic wave absorbers are used for wall surfaces of anechoic chambers for evaluating electronic devices, countermeasures against radio wave interference, and the like. A conventional radio wave absorber is obtained by impregnating, kneading, spraying, plating, or the like a conductive material such as carbon onto a base material such as urethane foam or styrene foam.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、従来の
電波吸収体では、母材となる発泡ウレタンや発泡スチレ
ンが、軽量で機械的強度に優れるものの、耐火性（不燃
性）に劣るという問題があった。一方、最近では安全上
の観点から、電波吸収体に耐火性が要求されている。特
に、電波暗室等のように閉塞した環境の中で用いられる
電波吸収体には、耐火性が強く要求されている。However, the conventional electromagnetic wave absorber has a problem that the urethane foam and the styrene foam as the base materials are light in weight and excellent in mechanical strength, but inferior in fire resistance (incombustibility). It was On the other hand, recently, from the viewpoint of safety, the wave absorber is required to have fire resistance. In particular, an electromagnetic wave absorber used in a closed environment such as an anechoic chamber is strongly required to have fire resistance.
【０００４】[0004]
【発明の目的】そこで、本発明の目的は、従来の軽量性
及び電波吸収特性を損なうことなく、耐火性を向上させ
ることにより、例えば電波暗室等に好適に用いることが
できる、電波吸収体を提供することにある。SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electromagnetic wave absorber which can be suitably used in, for example, an anechoic chamber by improving fire resistance without impairing the conventional lightweight and electromagnetic wave absorption characteristics. To provide.
【０００５】[0005]
【課題を解決するための手段】アルミナ、シリカ等を主
成分とするセラミック繊維は、耐火性（不燃性）に優れ
るので、不燃材料や断熱材料として用いられる。不織布
は、密度が非常に小さいので、発泡ウレタンと同様に大
型の四角錐や三角柱を形成しても軽量であり、電波吸収
体用の母材として適している。セラミック繊維を用いた
不織布の製造工程で導電性繊維を混ぜ合わせたり、セラ
ミック繊維の不織布にカーボン粒子を分散させた水溶液
を含浸させたりすることにより、本発明に係る電波吸収
体が製造される。本発明によれば、従来の電波吸収体と
同様の特性を得られるとともに、セラミック繊維特有の
不燃性を有するので、耐火性に優れた電波吸収体が得ら
れる。[Means for Solving the Problems] Ceramic fibers containing alumina, silica or the like as a main component are excellent in fire resistance (non-combustibility) and are therefore used as non-combustible materials or heat insulating materials. Since the non-woven fabric has a very low density, it is lightweight even if a large quadrangular pyramid or triangular prism is formed like the urethane foam, and is suitable as a base material for a radio wave absorber. The electromagnetic wave absorber according to the present invention is manufactured by mixing conductive fibers in a manufacturing process of a nonwoven fabric using ceramic fibers or impregnating a nonwoven fabric of ceramic fibers with an aqueous solution in which carbon particles are dispersed. According to the present invention, the characteristics similar to those of the conventional electromagnetic wave absorber can be obtained, and the electromagnetic wave absorber having excellent fire resistance can be obtained because it has the nonflammability peculiar to the ceramic fiber.
【０００６】セラミック繊維の不織布に導電性繊維やカ
ーボン粒子等を分散して得られる材料は、これらの導電
性材料の混合量により等価的な導電率を制御できる。し
たがって、導電性により得られる電波的伝搬損失を調整
できる。このような材料は、従来の電波吸収体用の発泡
ウレタンや発泡スチレンと類似する点が多いので、これ
らと同様の設計方法で電波吸収体を製作できる。A material obtained by dispersing conductive fibers or carbon particles in a non-woven fabric of ceramic fibers can control the equivalent conductivity by adjusting the mixing amount of these conductive materials. Therefore, the radio wave propagation loss obtained by conductivity can be adjusted. Since such a material has many similarities to the conventional urethane foam and styrene foam for the electromagnetic wave absorber, the electromagnetic wave absorber can be manufactured by the same design method as these.
【０００７】電波吸収体の設計では、材料の透磁率μ、
誘電率ε、厚さｄ等を調整することにより、所定の周波
数ｆにて電波吸収体の反射係数Гを仕様以下とする。一
般に導電率δと誘電率εとは式のような関係があるた
め、導電率δの変化は誘電率εの変化として扱うことが
できる。 ε＝ε’−ｊ・｛δ／（ω・ε0 ）｝ ・・・ ε’：誘電率の実数項，ω：２πｆ，ε0 ：真空中の誘
電率In designing an electromagnetic wave absorber, the magnetic permeability μ of the material is
By adjusting the dielectric constant ε, the thickness d, etc., the reflection coefficient Γ of the electromagnetic wave absorber is set to be equal to or less than the specification at a predetermined frequency f. In general, since the conductivity δ and the permittivity ε have a relationship as shown in the equation, a change in the conductivity δ can be treated as a change in the permittivity ε. ε = ε′−j · {δ / (ω · ε 0 )} ... ε ′: real number term of permittivity, ω: 2πf, ε 0 : permittivity in vacuum
【０００８】また、反射係数Гは式で表される。実際
の設計では、透磁率μ、誘電率ε及び厚さｄを任意に選
択できないので、１又は２つのパラメータの選択により
設計する場合が多くなる。 Г＝（Ｚ−１）／（Ｚ＋１） ・・・ Ｚ＝（μ／ε）1/2 ・ｔａｎｈ｛ｊ・（２π／λ）・
（ε・μ）1/2 ・ｄ｝ λ＝ｃ／（２π・ｆ） ｃ：光速The reflection coefficient Γ is expressed by the equation. In the actual design, the magnetic permeability μ, the dielectric constant ε and the thickness d cannot be arbitrarily selected, so that the design is often performed by selecting one or two parameters. Γ = (Z−1) / (Z + 1) ... Z = (μ / ε) 1/2 · tanh {j · (2π / λ) ·
(Ε ・ μ) 1/2・ d} λ = c / (2π ・ f) c: speed of light
【０００９】この関係式の反射係数Гは、自由空間中の
無限に広い金属平板の前面に電波吸収体を置いた場合の
ものである。また、導電性材料にカーボンや黒鉛を使用
した場合は、磁性を示さない。この場合、透磁率μは自
由空間の透磁率値に固定されるので、電波吸収体は上式
の誘電率ε，厚さｄのみを調整することにより設計す
る。The reflection coefficient Γ of this relational expression is for the case where the electromagnetic wave absorber is placed in front of an infinitely wide metal flat plate in free space. Further, when carbon or graphite is used as the conductive material, it does not exhibit magnetism. In this case, since the magnetic permeability μ is fixed to the magnetic permeability value in free space, the electromagnetic wave absorber is designed by adjusting only the dielectric constant ε and the thickness d of the above equation.
【００１０】[0010]
【発明の実施の形態】図１及び図２は、本発明に係る電
波吸収体の第一及び第二実施形態を示す断面図である。
第一実施形態の電波吸収体１０は、導電性繊維１２を付
着させたセラミック繊維１４によって、不織布状に形成
されたものである。第二実施形態の電波吸収体２０は、
カーボン粒子２２を付着させたセラミック繊維１４によ
って、不織布状に形成されたものである。1 and 2 are sectional views showing first and second embodiments of a radio wave absorber according to the present invention.
The radio wave absorber 10 of the first embodiment is formed in a non-woven fabric shape by the ceramic fibers 14 to which the conductive fibers 12 are attached. The radio wave absorber 20 of the second embodiment is
The ceramic fibers 14 to which the carbon particles 22 are attached are formed into a non-woven fabric.
【００１１】ここで用いたセラミック繊維１４はアルミ
ナ、シリカを主成分とする平均直径２．８μｍの繊維で
ある。当然のことながら、不燃性かつ非導電性であれば
他の組成の繊維も使用可能である。また、セラミック繊
維１４の平均直径も２．８μｍに限定するものではない
が、あまり太いと同密度のシートに成形したときにカー
ボン粒子２２が付着するため表面積が少なくなってしま
う。これらを考慮すると、セラミック繊維１４の直径は
１〜１００μｍが望ましい。さらに、導電性繊維１２
は、金属や黒鉛等の導体からなるものである。The ceramic fiber 14 used here is a fiber containing alumina and silica as main components and having an average diameter of 2.8 μm. Of course, fibers of other compositions can be used as long as they are non-flammable and non-conductive. The average diameter of the ceramic fibers 14 is not limited to 2.8 μm, but if the average diameter is too large, the carbon particles 22 will adhere to the sheet when formed into a sheet of the same density, resulting in a small surface area. Considering these, the diameter of the ceramic fiber 14 is preferably 1 to 100 μm. Furthermore, the conductive fiber 12
Is made of a conductor such as metal or graphite.
【００１２】カーボン粒子２２をセラミック繊維１４に
付着させるために、厚さ１０ｍｍのシート状に成形され
たセラミック繊維１４からなる不織布を、カーボン粒子
２２を分散させた水溶液に浸漬した。続いて、これを乾
燥させて電波吸収体２０を形成した。カーボン粒子２２
の付着量を、１ｇ／ｌ、２ｇ／ｌ、３ｇ／ｌ、５ｇ／ｌ
（電波吸収体２０の容量１ｌあたりのカーボン量）とな
るように含浸させたところ、１０ＧＨｚにおいてそれぞ
れ３ｄＢ、５ｄＢ、５ｄＢ、１０ｄＢの電波吸収性能を
得た。このように、本実施形態によれば、従来の軽量性
及び電波吸収特性を損なうことなく、セラミック繊維１
４の作用により耐火性を向上できる。In order to adhere the carbon particles 22 to the ceramic fibers 14, a non-woven fabric composed of the ceramic fibers 14 formed into a sheet having a thickness of 10 mm was immersed in an aqueous solution in which the carbon particles 22 were dispersed. Subsequently, this was dried to form the radio wave absorber 20. Carbon particles 22
1g / l, 2g / l, 3g / l, 5g / l
When impregnated so as to be (carbon amount per 1 l capacity of the radio wave absorber 20), radio wave absorption performances of 3 dB, 5 dB, 5 dB, and 10 dB were obtained at 10 GHz, respectively. As described above, according to the present embodiment, the ceramic fiber 1 can be manufactured without impairing the conventional lightness and electromagnetic wave absorption characteristics.
By the action of 4, the fire resistance can be improved.
【００１３】図３は、本発明に係る電波吸収体の第三実
施形態を示す断面図である。以下、図２及び図３に基づ
き説明する。第三実施形態の電波吸収体３０は、カーボ
ン粒子２２の付着量の異なる三枚の第二実施形態の電波
吸収体２０ａ，２０ｂ，２０ｃを積層したものである。
このとき、電磁波の入射する側から見て、カーボン粒子
２２の付着量の少ない順に積層する。ここでは、カーボ
ン粒子２２の付着量が１ｇ／ｌ，３ｇ／ｌ，５ｇ／ｌの
電波吸収体２０ａ，２０ｂ，２０ｃを積層したところ、
１０ＧＨｚにおいて２５ｄＢの電波吸収性能を得た。本
実施形態では、表面で反射する電磁波を減少させること
ができるので、電波吸収特性をより向上できる。また、
電波吸収体２０ａ側が比較的明るい色になるので、電波
暗室等を明るく構成でき、作業環境を改善できる。FIG. 3 is a sectional view showing a third embodiment of a radio wave absorber according to the present invention. Hereinafter, description will be made with reference to FIGS. The radio wave absorber 30 of the third embodiment is a laminate of three radio wave absorbers 20a, 20b, 20c of the second embodiment having different amounts of adhered carbon particles 22.
At this time, the carbon particles 22 are stacked in the ascending order of the adhesion amount of the carbon particles 22 as viewed from the side where the electromagnetic waves are incident. Here, when the electromagnetic wave absorbers 20a, 20b and 20c having the adhered amounts of the carbon particles 22 of 1 g / l, 3 g / l and 5 g / l are laminated,
A radio wave absorption performance of 25 dB was obtained at 10 GHz. In this embodiment, since the electromagnetic waves reflected on the surface can be reduced, the radio wave absorption characteristics can be further improved. Also,
Since the radio wave absorber 20a side has a relatively bright color, the anechoic chamber and the like can be made brighter and the working environment can be improved.
【００１４】図４は本発明に係る電波吸収体の第四実施
形態を示し、図４〔１〕が斜視図、図４〔２〕が図４
〔１〕におけるIV−IV線縦断面図である。以下、図２及
び図４に基づき説明する。第四実施形態の電波吸収体４
０は、カーボン粒子２２をセラミック繊維１２に付着さ
せるために、厚さ１０ｍｍのセラミック繊維１２からな
る不織布を、カーボン粒子２２を分散した水溶液に浸
し、乾燥中に高さ１５ｃｍの正四角錐に成形したもので
ある。FIG. 4 shows a fourth embodiment of a radio wave absorber according to the present invention. FIG. 4 [1] is a perspective view and FIG. 4 [2] is FIG.
FIG. 4 is a vertical sectional view taken along line IV-IV in [1]. Hereinafter, description will be given with reference to FIGS. 2 and 4. Radio wave absorber 4 of the fourth embodiment
In order to make the carbon particles 22 adhere to the ceramic fibers 12, a nonwoven fabric made of the ceramic fibers 12 having a thickness of 10 mm was dipped in an aqueous solution in which the carbon particles 22 were dispersed and formed into a regular pyramid having a height of 15 cm during drying. It is a thing.
【００１５】図５は本発明に係る電波吸収体の第五実施
形態を示し、図５〔１〕が斜視図、図５〔２〕が図５
〔１〕におけるＶ−Ｖ線縦断面図である。以下、図２及
び図５に基づき説明する。第五実施形態の電波吸収体５
０は、カーボン粒子２２をセラミック繊維１２に付着さ
せるために、厚さ１０ｍｍのセラミック繊維１２からな
る不織布を、カーボン粒子２２を分散した水溶液に浸
し、乾燥中に高さ１５ｃｍの正三角柱に成形したもので
ある。FIG. 5 shows a fifth embodiment of a radio wave absorber according to the present invention. FIG. 5 [1] is a perspective view and FIG. 5 [2] is FIG.
It is a VV line vertical cross-sectional view in [1]. Hereinafter, description will be made with reference to FIGS. Radio wave absorber 5 of the fifth embodiment
In order to make the carbon particles 22 adhere to the ceramic fibers 12, a non-woven fabric made of the ceramic fibers 12 having a thickness of 10 mm was dipped in an aqueous solution in which the carbon particles 22 were dispersed and formed into a regular triangular prism having a height of 15 cm during drying. It is a thing.
【００１６】図６は本発明に係る電波吸収体の第六実施
形態を示し、図６〔１〕が斜視図、図６〔２〕が図６
〔１〕におけるVI−VI線縦断面図である。以下、図２、
図３及び図６に基づき説明する。第六実施形態の電波吸
収体６０は、カーボン粒子２２の付着量の異なる三枚の
電波吸収体２０ａ，２０ｂ，２０ｃを積層したものであ
る。このとき、電磁波の入射する側から見て、カーボン
粒子２２の付着量の少ない順に積層する。積層後乾燥中
に、高さ１５ｃｍの正四角錐型に成形した。なお、底面
には、第二実施形態の電波吸収体２０を設けている。FIG. 6 shows a sixth embodiment of a radio wave absorber according to the present invention. FIG. 6 [1] is a perspective view and FIG. 6 [2] is FIG.
FIG. 6 is a vertical sectional view taken along line VI-VI in [1]. Hereinafter, FIG.
A description will be given based on FIGS. 3 and 6. The radio wave absorber 60 of the sixth embodiment is a stack of three radio wave absorbers 20a, 20b, 20c having different amounts of carbon particles 22 attached. At this time, the carbon particles 22 are stacked in the ascending order of the adhesion amount of the carbon particles 22 as viewed from the side where the electromagnetic waves are incident. During lamination and drying, it was formed into a regular pyramid shape with a height of 15 cm. The electromagnetic wave absorber 20 of the second embodiment is provided on the bottom surface.
【００１７】図７は本発明に係る電波吸収体の第七実施
形態を示し、図７〔１〕が斜視図、図７〔２〕が図７
〔１〕におけるVII −VII 線縦断面図である。以下、図
２、図３及び図７に基づき説明する。第七実施形態の電
波吸収体７０は、カーボン粒子２２の付着量の異なる三
枚の電波吸収体２０ａ，２０ｂ，２０ｃを積層したもの
である。このとき、電磁波の入射する側から見て、カー
ボン粒子２２の付着量の少ない順に積層する。積層後乾
燥中に、高さ１５ｃｍの正三角柱に成形した。なお、底
面には、第二実施形態の電波吸収体２０を設けている。FIG. 7 shows a seventh embodiment of a radio wave absorber according to the present invention. FIG. 7 [1] is a perspective view and FIG. 7 [2] is FIG.
FIG. 7 is a vertical sectional view taken along line VII-VII in [1]. Hereinafter, description will be given with reference to FIGS. 2, 3, and 7. The radio wave absorber 70 of the seventh embodiment is a stack of three radio wave absorbers 20a, 20b, 20c having different amounts of carbon particles 22 attached. At this time, the carbon particles 22 are stacked in the ascending order of the adhesion amount of the carbon particles 22 as viewed from the side where the electromagnetic waves are incident. During lamination and drying, it was formed into a regular triangular prism having a height of 15 cm. The electromagnetic wave absorber 20 of the second embodiment is provided on the bottom surface.
【００１８】図８は本発明に係る電波吸収体の第八実施
形態を示す縦断面図である。以下、図６乃至図８に基づ
き説明する。第八実施形態の電波吸収体８０は、第六又
は第七実施形態の電波吸収体６０，７０の底面に、厚さ
５ｍｍの平板状のフェライト８２を接合させたものであ
る。本実施形態では、フェライト８２の作用によって低
周波数の電磁波も吸収できるので、電波吸収特性をより
向上できる。FIG. 8 is a vertical sectional view showing an eighth embodiment of a radio wave absorber according to the present invention. Hereinafter, description will be given with reference to FIGS. 6 to 8. The radio wave absorber 80 of the eighth embodiment is obtained by joining a flat ferrite 82 having a thickness of 5 mm to the bottom surface of the radio wave absorbers 60 and 70 of the sixth or seventh embodiment. In the present embodiment, since the low-frequency electromagnetic wave can be absorbed by the action of the ferrite 82, the radio wave absorption characteristic can be further improved.
【００１９】図９は本発明に係る電波吸収体の第九実施
形態を示す縦断面図である。以下、図３、図６、図７及
び図９に基づき説明する。第九実施形態の電波吸収体９
０は、第六又は第七実施形態の電波吸収体６０，７０の
底面に、厚さ３０ｍｍの積層した第三実施形態の電波吸
収体３０を接合させたものである。本実施形態では、電
波吸収体３０の作用によって電波吸収特性をより向上で
きる。FIG. 9 is a vertical sectional view showing a ninth embodiment of a radio wave absorber according to the present invention. Hereinafter, description will be given with reference to FIGS. 3, 6, 7, and 9. Radio wave absorber 9 of the ninth embodiment
No. 0 is obtained by joining the radio wave absorber 30 of the third embodiment having a thickness of 30 mm to the bottom surface of the radio wave absorber 60 or 70 of the sixth or seventh embodiment. In the present embodiment, the radio wave absorber 30 can further improve the radio wave absorption characteristics.
【００２０】なお、本発明は、言うまでもなく、上記実
施形態に限定されるものではない。例えば、第二乃至第
九実施形態では、導電性材料としてカーボン粒子を用い
ているが、カーボン粒子の代わりに金属粒子や導電性繊
維等を用いてもよい。Needless to say, the present invention is not limited to the above embodiment. For example, in the second to ninth embodiments, carbon particles are used as the conductive material, but metal particles, conductive fibers, or the like may be used instead of carbon particles.
【００２１】[0021]
【発明の効果】請求項１乃至８記載の電波吸収体によれ
ば、導電性材料を付着させたセラミック繊維によって不
織布状に形成したことにより、従来の軽量性及び電波吸
収特性を損なうことなく、耐火性を向上できる。したが
って、電波暗室等に好適に用いることができる。According to the electromagnetic wave absorbers of claims 1 to 8, the non-woven fabric is made of the ceramic fibers to which the conductive material is adhered, so that the conventional light weight and the electromagnetic wave absorption characteristics are not impaired. Fire resistance can be improved. Therefore, it can be suitably used in an anechoic chamber or the like.
【００２２】請求項２，５及び６記載の電波吸収体によ
れば、導電性材料の付着量の異なる複数の請求項１記載
の電波吸収体を、当該付着量の少ない順又は多い順に積
層させたことにより、表面で反射する電磁波を減少させ
ることができるので、電波吸収特性をより向上できる。
また、電波吸収体の一方の面が比較的明るい色になるの
で、電波暗室等を明るく構成でき、作業環境を改善でき
る。According to the electromagnetic wave absorbers of claims 2, 5 and 6, a plurality of electromagnetic wave absorbers of claim 1 having different amounts of conductive material are laminated in order of increasing or decreasing amount of adhesion. As a result, the electromagnetic waves reflected on the surface can be reduced, and the radio wave absorption characteristics can be further improved.
Further, since one surface of the electromagnetic wave absorber has a relatively bright color, the anechoic chamber or the like can be made bright, and the working environment can be improved.
【００２３】請求項７記載の電波吸収体によれば、請求
項３，４，５又は６記載の電波吸収体の正方形乃至長方
形状の底面に、平板状のフェライトを接合したことによ
り、このフェライトの作用によって低周波数の電磁波も
吸収できるので、電波吸収特性をより向上できる。According to the electromagnetic wave absorber of the seventh aspect, the flat plate-shaped ferrite is bonded to the square or rectangular bottom surface of the electromagnetic wave absorber of the third, fourth, fifth or sixth aspect, so that the ferrite is obtained. Since the action of can also absorb low-frequency electromagnetic waves, the radio wave absorption characteristics can be further improved.
【００２４】請求項８記載の電波吸収体によれば、請求
項３，４，５又は６記載の電波吸収体の正方形乃至長方
形状の底面に、請求項１又は２記載の電波吸収体を積層
したことにより、電波吸収特性をより向上できる。According to the electromagnetic wave absorber of claim 8, the electromagnetic wave absorber of claim 1 or 2 is laminated on the square or rectangular bottom surface of the electromagnetic wave absorber of claim 3, 4, 5 or 6. By doing so, the electromagnetic wave absorption characteristics can be further improved.
【図１】本発明に係る電波吸収体の第一実施形態を示す
断面図である。FIG. 1 is a cross-sectional view showing a first embodiment of a radio wave absorber according to the present invention.
【図２】本発明に係る電波吸収体の第二実施形態を示す
断面図である。FIG. 2 is a sectional view showing a second embodiment of a radio wave absorber according to the present invention.
【図３】本発明に係る電波吸収体の第三実施形態を示す
断面図である。FIG. 3 is a cross-sectional view showing a third embodiment of a radio wave absorber according to the present invention.
【図４】本発明に係る電波吸収体の第四実施形態を示
し、図４〔１〕が斜視図、図４〔２〕が図４〔１〕にお
けるIV−IV線縦断面図である。FIG. 4 shows a fourth embodiment of a radio wave absorber according to the present invention, FIG. 4 [1] is a perspective view, and FIG. 4 [2] is a vertical sectional view taken along line IV-IV in FIG. 4 [1].
【図５】本発明に係る電波吸収体の第五実施形態を示
し、図５〔１〕が斜視図、図５〔２〕が図５〔１〕にお
けるＶ−Ｖ線縦断面図である。5 shows a fifth embodiment of a radio wave absorber according to the present invention, FIG. 5 [1] is a perspective view, and FIG. 5 [2] is a vertical sectional view taken along line VV in FIG. 5 [1].
【図６】本発明に係る電波吸収体の第六実施形態を示
し、図６〔１〕が斜視図、図６〔２〕が図６〔１〕にお
けるVI−VI線縦断面図である。6 shows a sixth embodiment of a radio wave absorber according to the present invention, FIG. 6 [1] is a perspective view, and FIG. 6 [2] is a vertical sectional view taken along line VI-VI in FIG. 6 [1].
【図７】本発明に係る電波吸収体の第七実施形態を示
し、図７〔１〕が斜視図、図７〔２〕が図７〔１〕にお
けるVII −VII 線縦断面図である。FIG. 7 shows a seventh embodiment of a radio wave absorber according to the present invention, FIG. 7 [1] is a perspective view, and FIG. 7 [2] is a vertical sectional view taken along line VII-VII in FIG. 7 [1].
【図８】本発明に係る電波吸収体の第八実施形態を示す
縦断面図である。FIG. 8 is a vertical cross-sectional view showing an eighth embodiment of a radio wave absorber according to the present invention.
【図９】本発明に係る電波吸収体の第九実施形態を示す
縦断面図である。FIG. 9 is a vertical cross-sectional view showing a ninth embodiment of a radio wave absorber according to the present invention.
１０，２０，３０，４０，５０，６０，７０，８０，９
０ 電波吸収体 １２ 導電性繊維（導電性材料） １４ セラミック繊維 ２２ カーボン粒子（導電性材料） ８２ フェライト10, 20, 30, 40, 50, 60, 70, 80, 9
0 Radio Wave Absorber 12 Conductive Fiber (Conductive Material) 14 Ceramic Fiber 22 Carbon Particles (Conductive Material) 82 Ferrite
───────────────────────────────────────────────────── フロントページの続き (72)発明者 戸川 斉 宮城県仙台市太白区郡山六丁目７番１号 株式会社トーキン内 (72)発明者 西村 幹夫 栃木県那須郡南那須町藤田1200 東北化工 株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Togawa 6-7-1 Koriyama, Taichiro-ku, Sendai-shi, Miyagi Tokin Co., Ltd. In the company
Claims (8)
によって不織布状に形成された電波吸収体。1. A radio wave absorber formed of a non-woven fabric of ceramic fibers to which a conductive material is attached.
請求項１記載の電波吸収体を、当該付着量の少ない順又
は多い順に積層させた電波吸収体。2. A radio wave absorber in which a plurality of the radio wave absorbers according to claim 1 having different amounts of adhesion of the conductive material are stacked in order of increasing or decreasing amount of adhesion.
錐状に形成された電波吸収体。3. A radio wave absorber formed in the shape of a quadrangular pyramid by the radio wave absorber according to claim 1.
柱状に形成された電波吸収体。4. A radio wave absorber formed by the radio wave absorber according to claim 1 in a triangular prism shape.
記導電性材料の付着量の少ない層が外側になるように、
四角錐状に形成された電波吸収体。5. The electromagnetic wave absorber according to claim 2, so that the layer having a small amount of the conductive material adhered is on the outside.
An electromagnetic wave absorber formed in the shape of a quadrangular pyramid.
記導電性材料の付着量の少ない層が外側になるように、
三角柱状に形成された電波吸収体。6. The electromagnetic wave absorber according to claim 2, wherein the layer having a small amount of the conductive material attached is on the outside.
An electromagnetic wave absorber formed in a triangular prism shape.
体の正方形乃至長方形状の底面に、平板状のフェライト
が接合された電波吸収体。7. A radio wave absorber in which a flat ferrite is bonded to a square or rectangular bottom surface of the radio wave absorber according to claim 3, 4, 5 or 6.
体の正方形乃至長方形状の底面に、請求項１又は２記載
の電波吸収体が積層された電波吸収体。8. A radio wave absorber in which the radio wave absorber according to claim 1 or 2 is laminated on a square or rectangular bottom surface of the radio wave absorber according to claim 3, 4, 5 or 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8422396A JPH09275295A (en) | 1996-04-05 | 1996-04-05 | Radio wave absorbent |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8422396A JPH09275295A (en) | 1996-04-05 | 1996-04-05 | Radio wave absorbent |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09275295A true JPH09275295A (en) | 1997-10-21 |
Family
ID=13824489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8422396A Pending JPH09275295A (en) | 1996-04-05 | 1996-04-05 | Radio wave absorbent |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09275295A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6407693B1 (en) | 1999-01-21 | 2002-06-18 | Tdk Corporation | Radio wave absorbent assembling member radio wave absorbent and method for producing the same |
| JP2003328469A (en) * | 1999-06-15 | 2003-11-19 | Nitto Boseki Co Ltd | Ceiling board with noncombustibility, sound absorption and radio wave absorption |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6452920A (en) * | 1987-08-21 | 1989-03-01 | Ohbayashi Corp | Pipe connection of excavator |
| JPH01187896A (en) * | 1988-01-21 | 1989-07-27 | Nec Corp | Material for radio wave absorber |
| JPH0444300A (en) * | 1990-06-12 | 1992-02-14 | W R Grace & Co | Electric wave absorber |
-
1996
- 1996-04-05 JP JP8422396A patent/JPH09275295A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6452920A (en) * | 1987-08-21 | 1989-03-01 | Ohbayashi Corp | Pipe connection of excavator |
| JPH01187896A (en) * | 1988-01-21 | 1989-07-27 | Nec Corp | Material for radio wave absorber |
| JPH0444300A (en) * | 1990-06-12 | 1992-02-14 | W R Grace & Co | Electric wave absorber |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6407693B1 (en) | 1999-01-21 | 2002-06-18 | Tdk Corporation | Radio wave absorbent assembling member radio wave absorbent and method for producing the same |
| JP2003328469A (en) * | 1999-06-15 | 2003-11-19 | Nitto Boseki Co Ltd | Ceiling board with noncombustibility, sound absorption and radio wave absorption |
| JP4576801B2 (en) * | 1999-06-15 | 2010-11-10 | 日東紡績株式会社 | Radio wave absorbing ceiling panel, method for manufacturing the same, and method for preventing indoor wireless communication failure using the same |
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