JP2003324008A - High-magnetic loss material - Google Patents
High-magnetic loss materialInfo
- Publication number
- JP2003324008A JP2003324008A JP2002128592A JP2002128592A JP2003324008A JP 2003324008 A JP2003324008 A JP 2003324008A JP 2002128592 A JP2002128592 A JP 2002128592A JP 2002128592 A JP2002128592 A JP 2002128592A JP 2003324008 A JP2003324008 A JP 2003324008A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- soft magnetic
- composite material
- powder
- particle size
- 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
- 239000000463 material Substances 0.000 title claims description 12
- 239000000843 powder Substances 0.000 claims abstract description 36
- 239000002131 composite material Substances 0.000 claims abstract description 32
- 230000035699 permeability Effects 0.000 claims abstract description 27
- 239000002184 metal Substances 0.000 claims abstract description 16
- 229910052751 metal Inorganic materials 0.000 claims abstract description 16
- 239000011159 matrix material Substances 0.000 claims abstract description 12
- 229920001971 elastomer Polymers 0.000 claims abstract description 10
- 239000002245 particle Substances 0.000 claims description 23
- 229920006235 chlorinated polyethylene elastomer Polymers 0.000 claims description 3
- 229920000800 acrylic rubber Polymers 0.000 claims description 2
- 150000002739 metals Chemical class 0.000 claims description 2
- 229920000058 polyacrylate Polymers 0.000 claims description 2
- 239000004709 Chlorinated polyethylene Substances 0.000 claims 1
- 239000013528 metallic particle Substances 0.000 claims 1
- 239000004033 plastic Substances 0.000 abstract description 5
- 229920003023 plastic Polymers 0.000 abstract description 5
- 230000002745 absorbent Effects 0.000 abstract 2
- 239000002250 absorbent Substances 0.000 abstract 2
- 229910001004 magnetic alloy Inorganic materials 0.000 description 9
- 230000000694 effects Effects 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 239000006096 absorbing agent Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910017060 Fe Cr Inorganic materials 0.000 description 1
- 229910002544 Fe-Cr Inorganic materials 0.000 description 1
- 229910002060 Fe-Cr-Al alloy Inorganic materials 0.000 description 1
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical compound [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 229910000889 permalloy Inorganic materials 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 229910000702 sendust Inorganic materials 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、軟磁性金属の粉末
をゴムまたはプラスチックのマトリクス中に分散させて
なる複合材料であって、１０ＭＨｚ〜１ＧＨｚの周波数
領域に磁性損失のピークを有する高磁性損失材料に関す
る。この複合材料は、この周波数領域において損失材料
として使用したとき、電磁波を損失させる高い能力を示
す。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material in which soft magnetic metal powder is dispersed in a rubber or plastic matrix and has a high magnetic loss having a peak of magnetic loss in the frequency range of 10 MHz to 1 GHz. Regarding materials. This composite material exhibits a high ability to lose electromagnetic waves when used as a lossy material in this frequency range.
【０００２】[0002]
【従来の技術】種々の電子機器類において、外部から来
るノイズ電磁波の干渉を防いだり、外部への電磁波の放
射を抑制したりするために、さまざまな電磁波シールド
が行なわれている。その中で、簡易であり普遍性がある
手段として好んで実施されているものは、軟磁性金属の
粉末をゴムまたはプラスチックのマトリクスの中に分散
させた複合材料を、シートそのほか任意の形状に成形し
てなる電磁波損失体、すなわち電磁波吸収体を使用する
ことである。軟磁性金属の粉末としては、センダスト、
パーマロイ、Ｆｅ−Ｃｒ合金、Ｆｅ−Ｃｒ−Ａｌ合金な
どのアトマイズ粉末、とくにそれをアトライター処理に
より扁平化したフレーク状の粉末が使用され、マトリク
ス材料としては塩素化ポリエチレンゴムやアクリルゴム
が、好んで用いられている。2. Description of the Related Art In various electronic devices, various electromagnetic wave shields are provided in order to prevent interference of noise electromagnetic waves coming from the outside and to suppress the emission of electromagnetic waves to the outside. Among them, a simple and universal method that has been favorably implemented is to mold a composite material in which soft magnetic metal powder is dispersed in a rubber or plastic matrix into a sheet or any other shape. It is to use an electromagnetic wave loss body, that is, an electromagnetic wave absorber. As the soft magnetic metal powder, sendust,
Atomized powder such as permalloy, Fe-Cr alloy, Fe-Cr-Al alloy, etc., especially flaky powder obtained by flattening it by an attritor process is used, and chlorinated polyethylene rubber or acrylic rubber is preferable as the matrix material. It is used in
【０００３】この種の損失材料の電磁波損失能は、複合
材料のもつ透磁率の虚部（磁性損失項）の共鳴ピークの
位置や、大きさに比例して定まる。従来の複合材料の共
鳴ピークは、一般に１ＧＨｚより高い周波数領域、多く
の場合、４〜５ＧＨｚに現れるから、電磁波が損失する
ピークもまた、１ＧＨｚより高いところに出る。ところ
が、電磁的両立性（ＥＭＣ，ElectroMagnetic Compatib
ility）のために使用する電磁波吸収体では、共鳴ピー
クを１ＧＨｚより低い周波数領域に位置させなければな
らない。The electromagnetic wave loss capability of this type of lossy material is determined in proportion to the position and size of the resonance peak of the imaginary part (magnetic loss term) of the magnetic permeability of the composite material. Since the resonance peak of the conventional composite material generally appears in a frequency region higher than 1 GHz, often 4 to 5 GHz, a peak at which electromagnetic waves are lost also appears in a region higher than 1 GHz. However, electromagnetic compatibility (EMC, ElectroMagnetic Compatib
In the electromagnetic wave absorber used for the ility), the resonance peak must be located in the frequency region lower than 1 GHz.
【０００４】発明者は、軟磁性金属の粉末をゴムまたは
プラスチックのマトリクスの中に分散させた複合材料に
おいて、磁性損失項の共鳴周波数の位置を左右する諸因
子について、さまざまな実験や解析を行ない、その中
で、複合材料の複素比透磁率や複素比誘電率に与える影
響は、軟磁性金属の粉末の粒径が最も大きいことを突き
止め、粒径を選択することにより、所望の領域に共鳴周
波数を位置させることが可能であることを見出した。The inventor has conducted various experiments and analyzes on various factors that influence the position of the resonance frequency of the magnetic loss term in a composite material in which a soft magnetic metal powder is dispersed in a rubber or plastic matrix. Among them, the effect on the complex relative permeability and complex relative permittivity of the composite material is to find out that the particle size of the soft magnetic metal powder is the largest, and by selecting the particle size, resonance in the desired region can be achieved. It has been found that it is possible to position the frequency.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、発明
者が得た上記の新しい知見を利用し、所望の周波数領域
とくに１０ＭＨｚから１ＧＨｚの範囲で所望の周波数領
域に、電磁波損失のピークを有する損失材料として有用
な複合材料を提供することにある。SUMMARY OF THE INVENTION The object of the present invention is to utilize the above new findings obtained by the inventor and to set the peak of electromagnetic wave loss in a desired frequency region, particularly in a desired frequency region in the range of 10 MHz to 1 GHz. An object is to provide a composite material useful as a loss material.
【０００６】[0006]
【課題を解決するための手段】本発明の高磁性損失材料
は、軟磁性金属の粉末をゴムまたはプラスチックのマト
リクス中に分散させてなる複合材料において、誘電率ε
0εr1、透磁率μ0のマトリクス中に、半径α、複素比誘
電率εr＝−ｊ（σ／ωr0）、複素比透磁率μrの金属粒
子が存在するときの，複合材料の周波数特性を示す式The high magnetic loss material of the present invention is a composite material in which soft magnetic metal powder is dispersed in a matrix of rubber or plastic and has a dielectric constant ε.
When a metal particle having a radius α, a complex relative permittivity ε r = −j (σ / ω r0 ), and a complex relative permeability μ r is present in a matrix of 0 ε r1 and magnetic permeability μ 0 , Formula showing frequency characteristics
【数３】 ここで[Equation 3] here
【数４】
（ｆは周波数、ｃは光の速度、ｊ1 (2)およびｊ~ 1 (2)は
第一種ベッセル関数、ｈ1 (2)およびｈ~ 1 (2)は第三種ベ
ッセル関数である。）に従い、かつ、使用するマトリク
ス材料および軟磁性金属の誘電率、透磁率および導電率
の実測値を用いて、複合シートのもつ複素比透磁率の実
部μ'reffを計算して、その落ち始めの周波数を求める
とともに、虚部μ"reffを計算してその盛り上がり部分
の周波数を求め、それらの周波数が所望の周波数領域に
位置する粉末粒径を見出し、その粒径を平均粒径とする
粉末を使用して構成した複合材料である。[Equation 4]
(F is frequency, c is speed of light, j1 (2)And j~ 1 (2)Is
Bessel function of the first kind, h1 (2)And h~ 1 (2)Is the third kind
It is a Russell function. ) According to and used
Materials, soft magnetic metals, permittivity, permeability and conductivity
By using the measured value of, the real value of the complex relative permeability of the composite sheet
Part μ 'reffAnd calculate the frequency at which it begins to fall
With the imaginary part μ "reffCalculate the swelling part
Frequency of these, and those frequencies in the desired frequency range
Find the powder particle size that is located and use that particle size as the average particle size
It is a composite material composed of powder.
【０００７】[0007]
【実施例】軟磁性金属であるＦｅ−７Ｃｒ−９Ａｌ合金
の溶湯をガス噴霧し、得られた粉末をＪＩＳに従ったフ
ルイでふるい分け、平均粒径がそれぞれ、１８１，１２
８，９０．５，６４，４２．５および２８．５μｍであ
る６種の粉末（ほぼ球形）を用意した。これらの粉末
を、塩素化ポリエチレンゴムと混練して金属粉末の充填
量が５０容積％である混練物を得、この混練物を圧延し
て、厚さ１mmのシートにした。EXAMPLE A molten metal of Fe-7Cr-9Al alloy, which is a soft magnetic metal, was gas-sprayed, and the obtained powder was sieved with a sieve according to JIS to obtain average particle sizes of 181 and 12, respectively.
Six types of powder (substantially spherical) having sizes of 8, 90.5, 64, 42.5 and 28.5 μm were prepared. These powders were kneaded with chlorinated polyethylene rubber to obtain a kneaded product having a metal powder filling amount of 50% by volume, and the kneaded product was rolled into a sheet having a thickness of 1 mm.
【０００８】Ｆｅ−７Ｃｒ−９Ａｌ合金の複素比透磁率
μrの実測値１２０および導電率σの実測値１／（１４
９×１０-6）［Ｓ／ｍ］を用いて、複合シートが示す複
素比透磁率の実部μ'reffの周波数特性を異なる平均粒
径の粉末ごとに計算して、図１のグラフを得た。また、
複合シートが示す複素比透磁率の実部μ'rの周波数特性
を実測して、図２のグラフを得た。計算値と実測値と
は、傾向として一致しており、軟磁性合金の粉末の粒径
が増大すると、複素比透磁率の実部μ'rが一定値から低
下を始める周波数は、低周波側へシフトしている。μ'r
の減少は、渦電流によるものと推測される。The measured value of complex relative permeability μ r of Fe-7Cr-9Al alloy 120 and the measured value of conductivity σ 1 / (14
9 × 10 −6 ) [S / m] was used to calculate the frequency characteristic of the real part μ ′ reff of the complex relative permeability of the composite sheet for each powder having different average particle diameters, and the graph of FIG. Obtained. Also,
The frequency characteristic of the real part μ ′ r of the complex relative permeability indicated by the composite sheet was measured, and the graph of FIG. 2 was obtained. Calculated and measured values are in agreement as trends, the particle size of the powder of the soft magnetic alloy is increased, the frequency of the real part mu 'r of the complex relative permeability starts to decrease from the predetermined value, the low-frequency side Are shifting to. μ ' r
It is speculated that the decrease in γ is due to the eddy current.
【０００９】同様にして、複合シートの複素比透磁率の
虚部μ”reffがもつ周波数特性を計算したものは図３の
グラフであり、虚部μ”rの実測値は、図４のグラフに
示すとおりである。ここでも、計算値および実測値の両
方において、曲線の盛り上がり部分が、粉末の平均粒径
の増大につれて、低周波側へシフトするという、一致し
た傾向が見られる。この盛り上がりは共鳴のあらわれで
あって、渦電流が引き起こしたものと解される。Similarly, the frequency characteristic of the imaginary part μ ″ reff of the complex relative permeability of the composite sheet is calculated as shown in the graph of FIG. 3, and the measured value of the imaginary part μ ″ r is shown in the graph of FIG. As shown in. Here again, in both the calculated value and the measured value, there is a consistent tendency that the rising portion of the curve shifts to the low frequency side as the average particle size of the powder increases. This swell is a manifestation of resonance and can be understood to be caused by eddy currents.
【００１０】この実施例における、軟磁性合金粉末の平
均粒径と複合材料の周波数特性との関連を直接見るた
め、図２のデータにもとづいて、各粉末の平均粒径につ
いて、複合材料の複素比透磁率の実部μ’rが４を下回
る周波数をプロットして、図５のグラフを得た。同様
に、複素比透磁率の虚部μ”rが０．５に達する周波数
をプロットして、図６のグラフを得た。In order to directly see the relationship between the average particle size of the soft magnetic alloy powder and the frequency characteristic of the composite material in this example, based on the data in FIG. the real part mu 'r of relative permeability by plotting the frequencies below 4, to give a graph of Fig. Similarly, the frequency at which the imaginary part μ ″ r of the complex relative permeability reaches 0.5 is plotted, and the graph of FIG. 6 is obtained.
【００１１】これらのグラフから、電磁波を損失させる
ピークの周波数を所望の領域に位置させるために適切
な、軟磁性合金粉末の平均粒径が選択できる。なお、軟
磁性合金それ自体の透磁率および導電率、ならびにマト
リクス材料の誘電率および透磁率は、材料の種類によっ
て若干の差異があり、それらの値が、図５および図６の
曲線をわずかながらずらすので、所望の周波数領域に吸
収のピークを位置させる上で最適な軟磁性合金粉末の平
均粒径には、わずかな変動がある。しかし、必要により
多少の実験を補充することにより、最適な平均粒径を見
出すことは容易である。From these graphs, the average particle size of the soft magnetic alloy powder can be selected so as to locate the peak frequency causing electromagnetic wave loss in a desired region. The magnetic permeability and conductivity of the soft magnetic alloy itself and the permittivity and magnetic permeability of the matrix material are slightly different depending on the type of material, and their values are slightly different from the curves in FIGS. 5 and 6. Since they are shifted, there is a slight variation in the average particle diameter of the soft magnetic alloy powder which is optimum for positioning the absorption peak in the desired frequency range. However, it is easy to find the optimum average particle size by supplementing some experiments if necessary.
【００１２】[0012]
【発明の効果】本発明に従って構成した複合材料は、所
望の周波数領域に吸収のピーク周波数を位置させること
が容易であるから、高度の損失率と高い効率において電
磁波を損失させることができる。従来は、ほとんど経験
的にしか決定することができなかった諸因子、とりわけ
軟磁性体の粉末の粒径を選択することが、本発明の体系
的な処理により効率化されて、実験を伴うとしても、従
来よりも、はるかに少ない労力で、製品の設計を行なう
ことが可能である。The composite material constructed according to the present invention can easily locate the peak frequency of absorption in a desired frequency range, and therefore can cause electromagnetic wave loss with a high loss rate and high efficiency. In the past, selecting factors that could be determined only almost empirically, especially the particle size of the soft magnetic powder, was made efficient by the systematic treatment of the present invention and involves experimentation. Also, it is possible to design a product with much less effort than before.
【００１３】とくに本発明は、これまで、有効な電磁波
損失材料を得ることが困難とされていた、１０ＭＨｚか
ら１ＧＨｚまでの周波数領域において有用な損失材料
を、設計・製作することを容易にしたものであって、Ｅ
ＭＣに対して寄与するところが大きい。In particular, the present invention facilitates the design and manufacture of a useful loss material in the frequency range from 10 MHz to 1 GHz, which has been difficult to obtain an effective electromagnetic wave loss material. And E
It greatly contributes to MC.
【図１】 軟磁性合金の粉末とゴムとの複合材料におい
て、粉末の粒径が複合材料の複素比透磁率の実部に与え
る影響を、計算結果として示すグラフ。FIG. 1 is a graph showing, as a calculation result, the effect of the particle size of the powder on the real part of the complex relative permeability of a composite material of a soft magnetic alloy powder and rubber.
【図２】 軟磁性合金の粉末とゴムとの複合材料におい
て、粉末の粒径が複合材料の複素比透磁率の実部に与え
る影響を、実測値として示すグラフ。FIG. 2 is a graph showing, as measured values, the effect of the particle size of the powder on the real part of the complex relative permeability of the composite material of the soft magnetic alloy powder and rubber.
【図３】 軟磁性合金の粉末とゴムとの複合材料におい
て、粉末の粒径が複合材料の複素比透磁率の虚部に与え
る影響を、計算結果として示すグラフ。FIG. 3 is a graph showing, as a calculation result, the effect of the particle size of the powder on the imaginary part of the complex relative permeability of the composite material in the composite material of the soft magnetic alloy powder and the rubber.
【図４】 軟磁性合金の粉末とゴムとの複合材料におい
て、粉末の粒径が複合材料の複素比透磁率の虚部に与え
る影響を、実測値として示すグラフ。FIG. 4 is a graph showing, as an actual measurement value, the effect of the particle size of the powder on the imaginary part of the complex relative permeability of the composite material in the composite material of the soft magnetic alloy powder and the rubber.
【図５】 図２のデータにもとづいて、複合材料の複素
比透磁率の実部が一定値を下回る周波数と、各粉末の平
均粒径との関係をプロットして得たグラフ。FIG. 5 is a graph obtained by plotting the relationship between the frequency at which the real part of the complex relative permeability of the composite material falls below a certain value and the average particle size of each powder based on the data of FIG.
【図６】 図４のデータにもとづいて、複合材料の複素
比透磁率の虚部が一定値に達する周波数と、各粉末の平
均粒径との関係をプロットして得たグラフ。FIG. 6 is a graph obtained by plotting the relationship between the frequency at which the imaginary part of the complex relative permeability of the composite material reaches a constant value and the average particle size of each powder, based on the data in FIG.
Claims (2)
ックのマトリクス中に分散させてなる複合材料におい
て、誘電率ε0εr1、透磁率μ0のマトリクス中に、半径
α、複素比誘電率εr＝−ｊ（σ／ωr0）、複素比透磁
率μrの金属粒子が存在するときの，複合材料の周波数
特性を示す式 【数１】 ここで 【数２】 （ｆは周波数、ｃは光の速度、ｊ1 (2)およびｊ~ 1 (2)は
第一種ベッセル関数、ｈ1 (2)およびｈ~ 1 (2)は第三種ベ
ッセル関数である。）に従い、かつ、使用するマトリク
ス材料および軟磁性金属の誘電率、透磁率および導電率
の実測値を用いて、複合シートのもつ複素比透磁率の実
部μ'reffを計算してその落ち始めの周波数を求めると
ともに、虚部μ"reffを計算してその盛り上がり部分の
周波数を求め、それらの周波数が所望の周波数領域に位
置する粉末粒径を見出し、その粒径を平均粒径とする粉
末を使用して構成した複合材料。1. A soft magnetic metal powder made of rubber or plastis.
Smell of composite material dispersed in matrix
And permittivity ε0εr1, Permeability μ0In the matrix of the radius
α, complex relative permittivity εr= -J (σ / ωr0), Complex relative permeability
Rate μrFrequency of composite materials in the presence of metallic particles
Expression that shows the characteristic [Equation 1] here [Equation 2] (F is frequency, c is speed of light, j1 (2)And j~ 1 (2)Is
Bessel function of the first kind, h1 (2)And h~ 1 (2)Is the third kind
It is a Russell function. ) According to and used
Materials, soft magnetic metals, permittivity, permeability and conductivity
By using the measured value of, the real value of the complex relative permeability of the composite sheet
Part μ 'reffAnd calculate the frequency at which it begins to fall
Both, imaginary part μ "reffAnd calculate the
Find frequencies and place them in the desired frequency range.
Find the particle size of the powder to be placed and use that particle size as the average particle size
Composite material made from powder.
レンまたはアクリルゴムを使用した請求項１の高磁性損
失材料。2. The high magnetic loss material according to claim 1, wherein chlorinated polyethylene or acrylic rubber is used as the matrix material.
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| Application Number | Priority Date | Filing Date | Title |
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| JP2002128592A JP2003324008A (en) | 2002-04-30 | 2002-04-30 | High-magnetic loss material |
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| JP2002128592A JP2003324008A (en) | 2002-04-30 | 2002-04-30 | High-magnetic loss material |
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| JP2003324008A true JP2003324008A (en) | 2003-11-14 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004165431A (en) * | 2002-11-13 | 2004-06-10 | Sanyo Special Steel Co Ltd | Electromagnetic wave absorber powder |
| WO2012129924A1 (en) * | 2011-03-31 | 2012-10-04 | 深圳光启高等理工研究院 | Wave-absorbing metamaterial |
| US9450312B2 (en) | 2013-09-20 | 2016-09-20 | Kabushiki Kaisha Toshiba | Magnetic metal particle aggregate and radio wave absorber |
-
2002
- 2002-04-30 JP JP2002128592A patent/JP2003324008A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004165431A (en) * | 2002-11-13 | 2004-06-10 | Sanyo Special Steel Co Ltd | Electromagnetic wave absorber powder |
| WO2012129924A1 (en) * | 2011-03-31 | 2012-10-04 | 深圳光启高等理工研究院 | Wave-absorbing metamaterial |
| US9208913B2 (en) | 2011-03-31 | 2015-12-08 | Kuang-Chi Innovative Technology Ltd. | Wave-absorbing metamaterial |
| US9450312B2 (en) | 2013-09-20 | 2016-09-20 | Kabushiki Kaisha Toshiba | Magnetic metal particle aggregate and radio wave absorber |
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