JP2003273569A - Wave absorber and manufacturing method of the same - Google Patents
Wave absorber and manufacturing method of the sameInfo
- Publication number
- JP2003273569A JP2003273569A JP2002071549A JP2002071549A JP2003273569A JP 2003273569 A JP2003273569 A JP 2003273569A JP 2002071549 A JP2002071549 A JP 2002071549A JP 2002071549 A JP2002071549 A JP 2002071549A JP 2003273569 A JP2003273569 A JP 2003273569A
- Authority
- JP
- Japan
- Prior art keywords
- particles
- radio wave
- wave absorber
- electromagnetic wave
- absorbing material
- 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.)
- Pending
Links
- 239000006096 absorbing agent Substances 0.000 title claims abstract description 31
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 239000002245 particle Substances 0.000 claims abstract description 43
- 239000011358 absorbing material Substances 0.000 claims abstract description 28
- 239000002612 dispersion medium Substances 0.000 claims abstract description 15
- 239000011230 binding agent Substances 0.000 claims abstract description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 19
- 229910052799 carbon Inorganic materials 0.000 claims description 19
- 229920005989 resin Polymers 0.000 claims description 8
- 239000011347 resin Substances 0.000 claims description 8
- 238000010521 absorption reaction Methods 0.000 abstract description 12
- 238000007711 solidification Methods 0.000 abstract 1
- 230000008023 solidification Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 7
- 230000005484 gravity Effects 0.000 description 6
- 239000010410 layer Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000003973 paint Substances 0.000 description 6
- -1 polyethylene Polymers 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 102100033041 Carbonic anhydrase 13 Human genes 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 101000867860 Homo sapiens Carbonic anhydrase 13 Proteins 0.000 description 1
- 101000777301 Homo sapiens Uteroglobin Proteins 0.000 description 1
- 229920002367 Polyisobutene Polymers 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 102100031083 Uteroglobin Human genes 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 229920005672 polyolefin resin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000013464 silicone adhesive Substances 0.000 description 1
- 239000007779 soft material Substances 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Landscapes
- Hard Magnetic Materials (AREA)
- Soft Magnetic Materials (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電波吸収特性の角度依
存性を低減させた電波吸収体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave absorber having reduced angular dependence of radio wave absorption characteristics.
【０００２】[0002]
【従来の技術】誘電損失型電波吸収体は一般に、電波の
入射角度により電波吸収特性が異なる電波吸収特性の角
度依存性を有する。そのため、一定の入射角の範囲で入
射した電波は吸収するが、その範囲を外れて入射した電
波は吸収しない。この電波吸収特性の角度依存性を改善
するためには電波吸収体の表面から背面にわたって材料
の複素比誘電率が連続的に変化するような構造とするの
が望ましいが、このような構造の傾斜材料を安定して製
造することは困難なため、従来、誘電損失型電波吸収体
の構造としては一般に、異なった複素比誘電率を持つ材
料により構成されたボードやシート、フィルムなどを積
層した多層構造が用いられてきた。2. Description of the Related Art In general, a dielectric loss type electromagnetic wave absorber has an angle dependency of an electromagnetic wave absorption characteristic in which an electromagnetic wave absorption characteristic varies depending on an incident angle of an electric wave. Therefore, the radio waves incident within a certain incident angle range are absorbed, but the radio waves incident outside the range are not absorbed. In order to improve the angle dependence of the electromagnetic wave absorption characteristics, it is desirable to have a structure in which the complex relative permittivity of the material continuously changes from the front surface to the back surface of the electromagnetic wave absorber. Since it is difficult to manufacture materials in a stable manner, the conventional structure of dielectric loss type electromagnetic wave absorbers has generally been a multilayer structure in which boards, sheets, films, etc., made of materials with different complex relative dielectric constants are laminated. Structures have been used.
【０００３】[0003]
【発明が解決すべき課題】しかしこのような多層構造で
は、前記したように複素比誘電率が連続的に変化してい
ないばかりでなく、多層の重ね合わせが煩雑であり重ね
合わせに専用の製造装置を必要としたり、各層の接着力
の確保が難しく、さらに接着層の複素比誘電率が全体の
特性に与える影響の評価が難しいという問題があった。However, in such a multi-layer structure, not only the complex relative permittivity does not change continuously as described above, but also the superposition of the multi-layers is complicated, and the dedicated manufacturing for the superposition is required. There is a problem that a device is required, it is difficult to secure the adhesive force of each layer, and it is difficult to evaluate the influence of the complex relative dielectric constant of the adhesive layer on the overall characteristics.
【０００４】また前記の問題の対策として、繊維に導電
性塗料を染みこませて放置することにより、重力で塗料
が下方に溜まることで導電塗料の含有率に勾配をつけて
複素比誘電率を傾斜させることも試みられているが、こ
のような方法では塗料の含有率の勾配は、繊維間の空隙
の大きさや塗料粘度及び放置時間の影響を受け、さらに
塗料粘度は放置時間とともに変化するためその制御は非
常に困難となるという問題があった。As a countermeasure against the above-mentioned problem, the conductive paint is soaked in the fibers and left to stand, whereby the paint is accumulated downward due to gravity, so that the content ratio of the conductive paint is graded so that the complex relative permittivity is increased. Inclination has been attempted, but in such a method, the gradient of the content rate of the paint is affected by the size of the voids between the fibers, the viscosity of the paint and the standing time, and the viscosity of the paint changes with the standing time. There was a problem that its control would be very difficult.
【０００５】本発明は、これらの問題を解決するために
なされたもので、複素比誘電率または導電率の分布が厚
さ方向に連続的に分布した電波吸収体およびその製造方
法を提供することを目的とする。The present invention has been made to solve these problems, and provides a radio wave absorber in which the distribution of complex relative permittivity or conductivity is continuously distributed in the thickness direction, and a method of manufacturing the same. With the goal.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、前記課題
を解決するための方法について鋭意研究し、電波吸収材
料よりなる粒子を用いることにより、従来のボードやシ
ート、フィルムなどを積層した多層構造によらずに複素
比誘電率または導電率の分布を電波吸収体の厚さ方向に
連続的に分布させることが可能であることを見出し本発
明に至ったものである。DISCLOSURE OF THE INVENTION The present inventors have diligently studied a method for solving the above-mentioned problems, and laminated conventional boards, sheets, films, etc. by using particles made of an electromagnetic wave absorbing material. The present inventors have found that it is possible to continuously distribute the distribution of complex relative permittivity or conductivity in the thickness direction of the radio wave absorber without depending on the multilayer structure.
【０００７】即ち、前記課題を解決するために請求項１
記載の電波吸収体は、電波吸収材料よりなる粒子の集合
体であって、前記粒子の複素比誘電率が厚さ方向に連続
的に変化して分布していることを特徴としている。[0007] That is, in order to solve the above-mentioned problems, claim 1
The described electromagnetic wave absorber is an aggregate of particles made of an electromagnetic wave absorbing material, and is characterized in that the complex relative permittivity of the particles is continuously varied and distributed in the thickness direction.
【０００８】請求項２記載の電波吸収体は、請求項１記
載の電波吸収体において、前記電波吸収材料よりなる粒
子がカーボンを含有し、かつその含有量が異なる粒子で
あることを特徴としている。A radio wave absorber according to a second aspect of the present invention is the radio wave absorber according to the first aspect, characterized in that the particles made of the radio wave absorbing material contain carbon, and the contents thereof are different. .
【０００９】請求項３記載の電波吸収体は、前記粒子は
樹脂にカーボンが含有されたものであることを特徴とし
ている。The radio wave absorber according to claim 3 is characterized in that the particles are made of resin containing carbon.
【００１０】請求項４記載の電波吸収体は、請求項１〜
３記載のいずれか１項記載の電波吸収体において、前記
粒子の平均粒子径が入射電波の波長の１／１０以下であ
ることを特徴としている。The electromagnetic wave absorber according to claim 4 is the electromagnetic wave absorber according to claim 1.
3. The radio wave absorber according to any one of 3 above is characterized in that the average particle diameter of the particles is 1/10 or less of the wavelength of the incident radio wave.
【００１１】請求項５記載の電波吸収体の製造方法は、
カーボン含有量が異なる電波吸収材料よりなる粒子を分
散媒中で沈降させ、その後分散媒を除去し、バインダー
により固化することを特徴としている。A method of manufacturing a radio wave absorber according to claim 5 is
It is characterized in that particles made of radio wave absorbing materials having different carbon contents are settled in a dispersion medium, the dispersion medium is then removed, and the binder is solidified.
【００１２】[0012]
【発明の実施の形態】本発明の電波吸収体の一実施形態
を、図に基づいて以下に説明する。図１は本発明による
電波吸収体の概念を示すものであり、電波吸収材料より
なる粒子１が厚さ方向に複素比誘電率が連続的に変化し
て分布している状態を示している。（複素比誘電率が大
きいほど濃く示してある）電波吸収材料粒子１はバイン
ダー２によって取り囲まれて固化している。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a radio wave absorber of the present invention will be described below with reference to the drawings. FIG. 1 shows the concept of a radio wave absorber according to the present invention, and shows a state in which particles 1 made of a radio wave absorbing material are distributed with the complex relative permittivity changing continuously in the thickness direction. The electromagnetic wave absorbing material particles 1 (which are darker as the complex relative permittivity is larger) are surrounded by the binder 2 and are solidified.
【００１３】次に本発明の電波吸収体の製造方法を図２
〜図７に基づいて説明する。本発明の電波吸収体は以下
に述べる方法により製造することができる。
（１） 電波吸収材料に導電性を付与するためカーボン
を予め電波吸収材料に一定の割合で混ぜ、ニーダー等で
混合する。この操作によりカーボンの含有量の異なる電
波吸収材料を作製する。電波吸収材料としては、セラミ
ックや樹脂等粒子状に加工できるものであれば特に限定
することなく使用できるが、加工性の点で樹脂が好まし
く例えばポリエチレン、ポリプロピレン、ポリイソブチ
レンなどのポリオレフィン系の樹脂やエポキシ樹脂、ポ
リエステル樹脂等の熱硬化型の樹脂を使用することがで
きる。混合するカーボンの種類についても特に限定され
ず、ＡＳＴＭコードＮ１００〜Ｎ９００の範囲で適宜選
定すればよい。
（２） （１）により作製したカーボンを添加した電波
吸収材料３を粉砕し粒子状とする。（図２）粉砕の方法
は樹脂等の軟らかい材料はペレタイザー等でペレット化
し、セラミック等の硬度の高い材料は、ボールミル等で
粉砕すればよい。粉砕した粒子形状は特に限定されない
が、電波の波長に対し１／１０以下の平均粒子径とする
ことが好ましい。１／１０を超えると誘電体である粒子
が個々に識別され、電波吸収特性が不均一となる。
（３） （１）により導電性を付与した電波吸収材料の
複素比誘電率を基にして、多層型とした場合の各層の厚
さと複素比誘電率を決定する。
（４） （３）の設計で得られた各層の厚さと複素比誘
電率に応じて、導電性を付与して粉砕した粒子状電波吸
収材料４の混合比を決定し混合する。（図３）
（５） カーボンを添加し粉砕した前記の材料より比重
がやや低い分散媒５中に（３）の混合物を投入し、攪拌
する。例えば電波吸収材料としてポリエチレンを用いカ
ーボンを添加して粒状とした場合は、粒子の比重は１．
１〜１．２程度となり分散媒としてアルコール等が使用
できる。
（６） カーボン含有量の異なる粒子状の各電波吸収材
料を分散媒５中で沈降させる。（図４）この操作により
カーボン含有量の多い粒子ほど比重が大きいため早く沈
降し、分散媒中で複素比誘電率を連続的に分布させるこ
とができる。この操作は重力沈降に限らず遠心分離等の
強制的な方法を用いてもよい。
（７） 分散媒を除去し、乾燥させる。この操作は分散
媒の種類により最適な加熱条件を選択すればよい。
（８） 分散媒を除去して乾燥させた状態の粒子にバイ
ンダー２を含浸させる。（図５）バインダーとしては、
一液性のシリコン系接着剤などを用いることができる。
（９） 必要に応じ余分なバインダー樹脂を吸引除去
し、軽量化、及び音響特性付与のため通気性を確保す
る。
（１０） バインダーを固化する。Next, a method of manufacturing the radio wave absorber of the present invention will be described with reference to FIG.
~ It demonstrates based on FIG. The radio wave absorber of the present invention can be manufactured by the method described below. (1) In order to impart conductivity to the electromagnetic wave absorbing material, carbon is mixed in advance with the electromagnetic wave absorbing material at a constant ratio and mixed with a kneader or the like. By this operation, radio wave absorbing materials having different carbon contents are produced. The radio wave absorbing material can be used without particular limitation as long as it can be processed into particles such as ceramics and resins, but resin is preferable from the viewpoint of processability, for example, polyolefin resin such as polyethylene, polypropylene, polyisobutylene, or the like. Thermosetting resins such as epoxy resin and polyester resin can be used. The kind of carbon to be mixed is not particularly limited, and may be appropriately selected within the range of ASTM codes N100 to N900. (2) The radio wave absorbing material 3 containing carbon prepared in (1) is crushed into particles. (FIG. 2) As for the pulverization method, soft materials such as resin may be pelletized by a pelletizer or the like, and materials having high hardness such as ceramics may be pulverized by a ball mill or the like. The shape of the crushed particles is not particularly limited, but it is preferable that the average particle diameter is 1/10 or less with respect to the wavelength of radio waves. When it exceeds 1/10, the particles that are dielectrics are individually identified, and the electromagnetic wave absorption characteristics become non-uniform. (3) Based on the complex relative permittivity of the electromagnetic wave absorbing material to which conductivity is given in (1), the thickness of each layer and the complex relative permittivity in the case of the multilayer type are determined. (4) Depending on the thickness of each layer and the complex relative permittivity obtained in the design of (3), the mixing ratio of the particulate electromagnetic wave absorbing material 4 which has been provided with conductivity and pulverized is determined and mixed. (FIG. 3) (5) The mixture of (3) is put into a dispersion medium 5 having a specific gravity slightly lower than that of the above-mentioned material to which carbon has been added and ground, and the mixture is stirred. For example, when polyethylene is used as the radio wave absorbing material and carbon is added to form particles, the specific gravity of the particles is 1.
Alcohol or the like can be used as the dispersion medium. (6) The particulate electromagnetic wave absorbing materials having different carbon contents are settled in the dispersion medium 5. (FIG. 4) By this operation, particles having a higher carbon content have a larger specific gravity and thus settle faster and the complex relative permittivity can be continuously distributed in the dispersion medium. This operation is not limited to gravity sedimentation, and a forced method such as centrifugation may be used. (7) Remove the dispersion medium and dry. For this operation, optimum heating conditions may be selected depending on the type of dispersion medium. (8) The binder 2 is impregnated into the particles in a dried state after removing the dispersion medium. (Figure 5) As a binder,
A one-component silicone adhesive or the like can be used. (9) Excessive binder resin is suctioned and removed as needed to ensure air permeability for weight reduction and imparting acoustic characteristics. (10) Solidify the binder.
【００１４】[0014]
【発明の効果】本発明の電波吸収体によれば、電波吸収
材料よりなる粒子を前記粒子の複素比誘電率が厚さ方向
に連続的に変化するように分布しているので、電波吸収
特性の角度依存性が小さくなる。また、前記粒子がカー
ボン含有量の異なる粒子であることにより、導電率の異
なる電波吸収材料粒子の混合比を設計に応じて決定する
ことが可能となる。前記粒子を樹脂とすることにより、
カーボンの添加及び粒子形状への加工が容易となる。前
記粒子は、その平均粒子径を電波の波長に対し１／１０
以下の平均粒子径とすることにより電波吸収特性が均一
となる。According to the radio wave absorber of the present invention, since the particles made of the radio wave absorbing material are distributed so that the complex relative permittivity of the particles continuously changes in the thickness direction, the radio wave absorption characteristic is obtained. Angle dependence of is reduced. Further, since the particles have different carbon contents, it becomes possible to determine the mixing ratio of the radio wave absorbing material particles having different electric conductivity according to the design. By using the particles as a resin,
It becomes easy to add carbon and process it into a particle shape. The average particle size of the particles is 1/10 of the wavelength of radio waves.
By setting the average particle size below, the radio wave absorption characteristics become uniform.
【００１５】さらに、本発明の電波吸収体の製造方法に
よれば、従来困難であった電波吸収体の表面から背面に
わたって材料の複素比誘電率が連続的に変化するような
構造の傾斜材料を安定して製造することが可能となる。
また、粉砕器、混合層、沈殿槽のみで様々な複素比誘電
率の分布構造を実現できるため設計の自由度が高い。さ
らに、本製造方法では、粒子形状、粒子径、及び粒度分
布を制御することにより電波吸収体の空隙部分を考慮し
た全体の密度、また粒子間の空隙のサイズをコントロー
ルすることができ、これにより電波吸収特性だけでなく
音波吸収特性の制御も可能となる。Further, according to the method of manufacturing a radio wave absorber of the present invention, a gradient material having a structure in which the complex relative permittivity of the material continuously changes from the front surface to the back surface of the radio wave absorber, which has been difficult in the past, is obtained. It becomes possible to manufacture stably.
Moreover, since various complex relative permittivity distribution structures can be realized only with a crusher, a mixing layer, and a settling tank, the degree of freedom in design is high. Furthermore, in the present production method, the overall density in consideration of the void portion of the radio wave absorber and the size of voids between particles can be controlled by controlling the particle shape, particle size, and particle size distribution. It is possible to control not only the radio wave absorption characteristics but also the sound wave absorption characteristics.
【図１】本発明の電波吸収体の概念を示す図。FIG. 1 is a diagram showing the concept of a radio wave absorber of the present invention.
【図２】電波吸収材料を粉砕し粒子状とする工程を示す
図。FIG. 2 is a diagram showing a step of pulverizing a radio wave absorbing material into particles.
【図３】粉砕した粒子状の電波吸収材料を混合した状態
を示す図。FIG. 3 is a view showing a state in which a pulverized particulate radio wave absorbing material is mixed.
【図４】粉砕した粒子状の電波吸収材料を分散媒中で沈
降させた状態を示す図。FIG. 4 is a view showing a state in which a pulverized particulate electromagnetic wave absorbing material is settled in a dispersion medium.
【図５】粉砕した粒子状の電波吸収材料にバインダーを
含浸させた状態を示す図。FIG. 5 is a view showing a state in which a crushed particulate radio wave absorbing material is impregnated with a binder.
１・・・・粒子状の電波吸収材料
２・・・・バインダー
３・・・・カーボンの含有量の異なる電波吸収材料
４・・・・粉砕された粒子状の電波吸収材料
５・・・・分散媒
６・・・・比重に応じて沈降したカーボン含有量の異な
る粒子状の電波吸収材料1 ... ・ Particulate electromagnetic wave absorbing material 2 ... Binder 3 ... Electromagnetic wave absorbing material with different carbon content 4 ... Grinded particulate electromagnetic wave absorbing material 5 ... Dispersion medium 6 ... Particulate electromagnetic wave absorbing material with different carbon content settled according to specific gravity
───────────────────────────────────────────────────── フロントページの続き (72)発明者 丹田 修 神奈川県川崎市川崎区小田栄２丁目１番１ 号 昭和電線電纜株式会社内 (72)発明者 小林 由紀 神奈川県川崎市川崎区小田栄２丁目１番１ 号 昭和電線電纜株式会社内 Ｆターム(参考） 5E040 BB03 CA13 HB19 5E321 BB32 CC16 GG05 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Osamu Tanda 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa No. Showa Densen Denki Co., Ltd. (72) Inventor Yuki Kobayashi 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa No. Showa Densen Denki Co., Ltd. F-term (reference) 5E040 BB03 CA13 HB19 5E321 BB32 CC16 GG05
Claims (5)
て、前記粒子の複素比誘電率が厚さ方向に連続的に変化
して分布していることを特徴とする電波吸収体。1. An electromagnetic wave absorber comprising an aggregate of particles made of an electromagnetic wave absorbing material, wherein the complex relative permittivity of the particles is continuously varied and distributed in a thickness direction.
粒子はカーボンを含有し、かつカーボン含有量が異なる
粒子であることを特徴とする電波吸収体。2. The radio wave absorber according to claim 1, wherein the particles contain carbon and have different carbon contents.
波吸収体において、前記粒子は樹脂にカーボンが含有さ
れたものであることを特徴とする電波吸収体。3. The radio wave absorber according to claim 1, wherein the particles are made of resin containing carbon.
波吸収体において、前記粒子の平均粒子径が入射電波の
波長の１／１０以下であることを特徴とする電波吸収
体。4. The radio wave absorber according to any one of claims 1 to 3, wherein the average particle diameter of the particles is 1/10 or less of the wavelength of incident radio waves.
なる粒子を分散媒中で沈降させ、その後分散媒を除去
し、バインダーにより固化することを特徴とする電波吸
収体の製造方法。5. A method for producing an electromagnetic wave absorber, characterized in that particles made of an electromagnetic wave absorbing material having different carbon contents are settled in a dispersion medium, the dispersion medium is removed thereafter, and the solidified by a binder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002071549A JP2003273569A (en) | 2002-03-15 | 2002-03-15 | Wave absorber and manufacturing method of the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002071549A JP2003273569A (en) | 2002-03-15 | 2002-03-15 | Wave absorber and manufacturing method of the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003273569A true JP2003273569A (en) | 2003-09-26 |
Family
ID=29201795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002071549A Pending JP2003273569A (en) | 2002-03-15 | 2002-03-15 | Wave absorber and manufacturing method of the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003273569A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005197307A (en) * | 2003-12-26 | 2005-07-21 | Nippon Muki Co Ltd | Solid electromagnetic wave absorption material |
| WO2006064782A1 (en) * | 2004-12-17 | 2006-06-22 | Kabushiki Kaisha Fine Rubber Kenkyuusho | Dielectric raw material, antenna device, portable phone and electromagnetic wave shielding body |
| WO2017217098A1 (en) * | 2016-06-14 | 2017-12-21 | 日立オートモティブシステムズ株式会社 | Millimeter-wave band communication device |
| WO2025173674A1 (en) * | 2024-02-13 | 2025-08-21 | 出光興産株式会社 | Radio wave absorber |
-
2002
- 2002-03-15 JP JP2002071549A patent/JP2003273569A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005197307A (en) * | 2003-12-26 | 2005-07-21 | Nippon Muki Co Ltd | Solid electromagnetic wave absorption material |
| WO2006064782A1 (en) * | 2004-12-17 | 2006-06-22 | Kabushiki Kaisha Fine Rubber Kenkyuusho | Dielectric raw material, antenna device, portable phone and electromagnetic wave shielding body |
| US8715533B2 (en) | 2004-12-17 | 2014-05-06 | Asahi R&D Co., Ltd. | Dielectric raw material, antenna device, portable phone and electromagnetic wave shielding body |
| WO2017217098A1 (en) * | 2016-06-14 | 2017-12-21 | 日立オートモティブシステムズ株式会社 | Millimeter-wave band communication device |
| JP2017224904A (en) * | 2016-06-14 | 2017-12-21 | 日立オートモティブシステムズ株式会社 | Millimeter wave band communication device |
| US10756426B2 (en) | 2016-06-14 | 2020-08-25 | Hitachi Automotive Systems, Ltd. | Millimeter-wave band communication device |
| WO2025173674A1 (en) * | 2024-02-13 | 2025-08-21 | 出光興産株式会社 | Radio wave absorber |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Li et al. | Stereolithography based additive manufacturing of high-k polymer matrix composites facilitated by thermal plasma processed barium titanate microspheres | |
| WO2001078085A3 (en) | Low density dielectric having low microwave loss | |
| CN100482775C (en) | Solid lubricant agglomerates for coating applications and method for producing the same | |
| WO1994020280A1 (en) | Method of manufacturing wood-like product and the product | |
| KR940021421A (en) | Lamellar alumina | |
| US20130120959A1 (en) | Dielectric material sheet and process for production thereof, and electromagnetic wave absorber | |
| US11081802B2 (en) | Electromagnetic-wave-absorbing materials for various applications | |
| WO2004038834A3 (en) | Particle comprising a graphite core coated with at least a continuous or discontinuous coating, method for obtaining same and uses thereof | |
| CN106794997A (en) | Aggregation of hexaboride fine particles, hexaboride fine particle dispersion, hexaboride fine particle dispersion, hexaboride fine particle dispersion interlayer transparent substrate, infrared absorbing film and infrared absorbing glass | |
| CN105304260B (en) | A kind of three-dimensionally shaped electromagnetic material preparation method and preparation system | |
| KR100722798B1 (en) | Method of manufacturing electromagnetic wave absorption sheet, method for sorting powder and electromagnetic wave absorption sheet | |
| JP2003273569A (en) | Wave absorber and manufacturing method of the same | |
| WO2011052160A1 (en) | Method for producing ito sintered body and method for producing ito sputtering target | |
| JP7768486B2 (en) | Antistatic sound-absorbing material and its manufacturing method, speakers and electronic devices | |
| JP2002100238A (en) | Sheet-shaped moldings and laminates | |
| JP2008311255A (en) | Composite magnetic material and method for producing the same | |
| JP2000277973A (en) | Ferrite containing fiber and manufacture thereof | |
| CN100413002C (en) | Method for producing electromagnetic wave absorbing sheet, method for classifying powder | |
| Sari et al. | Effect of Milling Time on the Microstructure and Dielectric Properties of Chitosan Nanopowder. | |
| EP4538229A1 (en) | Method for producing spherical silica powder | |
| JP3751990B2 (en) | Granular polymer composite and method for producing the same | |
| JP2006093288A (en) | Wave absorption sheet | |
| JP2673916B2 (en) | High bulk density wood flour and method for producing high bulk density wood flour | |
| JP7666595B2 (en) | Method for producing liquid crystal polymer web | |
| DE29621804U1 (en) | Radiation absorbing material |