JP2005123531A - Powder for electromagnetic wave absorber - Google Patents
Powder for electromagnetic wave absorber Download PDFInfo
- Publication number
- JP2005123531A JP2005123531A JP2003359576A JP2003359576A JP2005123531A JP 2005123531 A JP2005123531 A JP 2005123531A JP 2003359576 A JP2003359576 A JP 2003359576A JP 2003359576 A JP2003359576 A JP 2003359576A JP 2005123531 A JP2005123531 A JP 2005123531A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- electromagnetic wave
- wave absorber
- alloy
- raw 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
- 239000000843 powder Substances 0.000 title claims abstract description 64
- 239000006096 absorbing agent Substances 0.000 title claims abstract description 23
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 27
- 239000001301 oxygen Substances 0.000 claims abstract description 27
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 27
- 239000002245 particle Substances 0.000 claims abstract description 15
- 239000007789 gas Substances 0.000 claims abstract description 6
- 239000002994 raw material Substances 0.000 claims description 19
- 229910045601 alloy Inorganic materials 0.000 claims description 17
- 239000000956 alloy Substances 0.000 claims description 17
- 229910017060 Fe Cr Inorganic materials 0.000 claims description 4
- 229910002544 Fe-Cr Inorganic materials 0.000 claims description 4
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 claims description 4
- 229910002796 Si–Al Inorganic materials 0.000 claims description 4
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical compound [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 claims description 4
- 238000009689 gas atomisation Methods 0.000 claims description 4
- 239000000463 material Substances 0.000 abstract description 6
- 239000000203 mixture Substances 0.000 abstract description 4
- 229910000846 In alloy Inorganic materials 0.000 abstract 1
- 230000001747 exhibiting effect Effects 0.000 abstract 1
- 238000010521 absorption reaction Methods 0.000 description 14
- 238000000034 method Methods 0.000 description 7
- 238000010298 pulverizing process Methods 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000002184 metal Substances 0.000 description 3
- 239000004709 Chlorinated polyethylene Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000009692 water atomization Methods 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000013467 fragmentation Methods 0.000 description 1
- 238000006062 fragmentation reaction Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000009700 powder processing Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000007779 soft material Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Abstract
Description
本発明は、電磁波吸収体に用いる偏平粉末に関するものである。 The present invention relates to a flat powder used for an electromagnetic wave absorber.
従来、パソコンや携帯電話等の各種電子機器の作動周波数は益々高周波化しており、これらの機器から発生する不要放射ノイズはＭＨｚ帯域からＧＨｚ帯域へ高周波化してきているため、従来のノイズフイルタではノイズ低減効果が不十分となってきている。一方、上記各種電子機器の小型化、軽量化、高周波化に伴い、電磁波障害が深刻化し、準マイクロ波帯での高周波ノイズを対策する製品が求められている。このような背景のもとに、例えば特開平１１−８７１１７号公報（特許文献１）に開示されているように、軟磁性材料の粉末を厚み３μｍ以下に偏平化し、ゴムシートに練り込んで２ＧＨｚ以上の高周波数の電磁波を吸収できるような電波吸収体が提案されている。 Conventionally, the operating frequency of various electronic devices such as personal computers and mobile phones has been increasing, and unnecessary radiation noise generated from these devices has been increasing from the MHz band to the GHz band. The reduction effect is becoming insufficient. On the other hand, with the miniaturization, weight reduction, and high frequency of the various electronic devices, electromagnetic interference becomes serious, and a product that measures high frequency noise in the quasi-microwave band is required. Against this background, for example, as disclosed in JP-A-11-87117 (Patent Document 1), the soft magnetic material powder is flattened to a thickness of 3 μm or less and kneaded into a rubber sheet to obtain 2 GHz. A radio wave absorber capable of absorbing the above high frequency electromagnetic waves has been proposed.
また、特開２００２−１０５５１２号公報（特許文献２）および特開２００２−１３４３０９号公報（特許文献３）に開示されているように、電磁波吸収材用偏平粉末の製造方法において、粉末を偏平化する際の雰囲気中の酸素含有量を５〜２０％に制御することにより、処理中の再凝着を防止し効率の良い偏平化を可能とする電磁波吸収材用偏平粉末の製造方法や粉末の平均Ｓ／ｔ（粉末の断面積と厚みの比）が５０ｍｍ以上の偏平粉である電磁波吸収体用粉末について提案されている。
上述した特許文献１の場合は、偏平化する際の詳細な条件について、特に雰囲気について明確な開示がない。また、この偏平化はボールミルなどの手段によっているが、条件によっては、偏平化加工の際に生じる新生面が加工時の衝撃により、分断微細化、再凝集による粗大化といった悪循環が発生しやすく、粗大な粉末ができるという問題がある。特に電磁波吸収材等に用いる場合には、アスペクト比が大きく、かつ、一定以下の大きさの粉末が必要であり、粗大粉末では吸収特性が劣化すると言う問題がある。 In the case of Patent Document 1 described above, there is no clear disclosure regarding the detailed conditions for flattening, particularly the atmosphere. In addition, this flattening is performed by means such as a ball mill, but depending on the conditions, the new surface generated during flattening processing is subject to a vicious circle such as fragmentation and coarsening due to re-aggregation due to impact during processing. There is a problem that a simple powder can be formed. In particular, when used for an electromagnetic wave absorber or the like, a powder having a large aspect ratio and a certain size or less is required, and there is a problem that the absorption characteristics of a coarse powder deteriorate.
また、特許文献２の場合は、粉末を偏平化する際の雰囲気中の酸素含有量を５〜２０％に制御することが記載されているが、しかし、偏平加工する前の原料粉末の酸素濃度を制御するものでなく、従来の水アトマイズや鋳造−粉砕での原料粉末の酸素値は、０．２ｍａｓｓ％以上となるのが通常である。このように酸素値が高い粉末をボールミルやアトライタで偏平化した場合、十分な偏平化が進行する以前に粉砕が行われてしまい、アスペクト比が大きくとれないと言う問題がある。また、特許文献２の場合は、粉末の断面積と厚みの比が５０ｍｍ以上の偏平化については記載されているが、原料粉末に酸化物が含まれていることにより、加工時に偏平化と粉砕がバランス良く行われＧＨｚ帯域で高い吸収特性が出る形状を容易に製造することに関する記載は全く開示されていない。 In the case of Patent Document 2, it is described that the oxygen content in the atmosphere when flattening the powder is controlled to 5 to 20%. However, the oxygen concentration of the raw material powder before flattening is described. In general, the oxygen value of the raw material powder in conventional water atomization or casting-pulverization is 0.2 mass% or more. When the powder having a high oxygen value is flattened with a ball mill or an attritor as described above, there is a problem that the pulverization is performed before sufficient flattening proceeds and the aspect ratio cannot be increased. Further, in the case of Patent Document 2, although the flattening in which the ratio of the cross-sectional area of the powder to the thickness is 50 mm or more is described, since the raw material powder contains an oxide, the flattening and pulverization are performed during processing. Is not disclosed at all regarding the easy manufacture of a shape that is well balanced and exhibits high absorption characteristics in the GHz band.
上述したような問題を解消するために、発明者らは鋭意開発を進めた結果、粉末形状を決定する因子として、硬さ以外に原料粉末の酸素量との関係を見出し、０．０８ｍａｓｓ％以下にすることにより、アスペクト比が大きくなり、吸収特性も向上することが分かった。その発明の要旨とするところは、
（１）電磁波吸収体用の合金粉末おいて、偏平加工する前の原料粉末の酸素濃度が０．００１〜０．０８ｍａｓｓ％である粉末を偏平加工によりアスペクト比１０以上、平均粒径２０〜５０μｍにすることを特徴とする電磁波吸収体用粉末。
（２）前記（１）に記載の偏平加工する前の原料粉末の酸素濃度を０．０３〜０．０６ｍａｓｓ％とすることを特徴とする電磁波吸収体用粉末。
（３）前記（１）または（２）に記載の原料粉末をＯ2 混合ガスにてガスアトマイズ法により製造することを特徴とする電磁波吸収体用粉末。
（４）前記（１）〜（３）に記載の原料粉末として、Ｆｅ−Ｎｉ系合金、Ｆｅ−Ｃｒ系合金、Ｆｅ−Ｓｉ−Ａｌ系合金を用いることを特徴とする電磁波吸収体用粉末にある。
In order to solve the problems as described above, the inventors have intensively developed, and as a factor determining the powder shape, the relationship with the oxygen content of the raw material powder is found in addition to the hardness, and is 0.08 mass% or less. As a result, it was found that the aspect ratio was increased and the absorption characteristics were improved. The gist of the invention is that
(1) In an alloy powder for an electromagnetic wave absorber, a powder whose raw material powder has an oxygen concentration of 0.001 to 0.08 mass% before flattening is processed by flattening and has an aspect ratio of 10 or more and an average particle size of 20 to 50 μm. The powder for electromagnetic wave absorbers characterized by making it.
(2) An electromagnetic wave absorber powder characterized in that the oxygen concentration of the raw material powder before flattening according to (1) is 0.03 to 0.06 mass%.
(3) A powder for an electromagnetic wave absorber, wherein the raw material powder described in (1) or (2) is produced by a gas atomization method using an O 2 mixed gas.
(4) As a raw material powder according to (1) to (3), an Fe-Ni alloy, an Fe-Cr alloy, or an Fe-Si-Al alloy is used. is there.
本発明による電磁波吸収体用の合金粉末であるＦｅ−Ｎｉ系合金、Ｆｅ−Ｃｒ系合金およびＦｅ−Ｓｉ−Ａｌ系合金の偏平加工する前の原料粉末の酸素濃度が０．００１〜０．０８ｍａｓｓ％である粉末を偏平加工によりアスペクト比１０以上、平均粒径２０〜５０μｍなる粉末は電磁波吸収特性の優れた電磁波吸収体用粉末を得ることが出来る極めて優れた効果を奏するものである。 The oxygen concentration of the raw material powder before flattening of the Fe—Ni alloy, Fe—Cr alloy and Fe—Si—Al alloy, which are alloy powders for electromagnetic wave absorbers according to the present invention, is 0.001 to 0.08 mass % Powder having an aspect ratio of 10 or more and an average particle size of 20 to 50 μm by flattening has an excellent effect of obtaining an electromagnetic wave absorber powder having excellent electromagnetic wave absorption characteristics.
以下、本発明について詳細に説明する。
本発明における電磁波吸収体用の合金粉末である原料粉末としての金属組織は、Ｆｅ−Ｎｉ系合金、Ｆｅ−Ｃｒ系合金、Ｆｅ−Ｓｉ−Ａｌ系合金とした。その理由は、耐食性が大きく、硬さの観点並びに飽和磁束密度が大きく高周波対応が可能なことから定めたものである。
Hereinafter, the present invention will be described in detail.
The metal structure as the raw material powder that is an alloy powder for an electromagnetic wave absorber in the present invention was an Fe—Ni alloy, an Fe—Cr alloy, or an Fe—Si—Al alloy. The reason is determined from the fact that the corrosion resistance is high, the hardness is high, the saturation magnetic flux density is large, and high frequency response is possible.
また、偏平加工する前の原料粉末の酸素濃度を０．００１〜０．０８ｍａｓｓ％とした理由は、従来の水アトマイズや鋳造−粉砕での原料粉末の酸素値は、０．２ｍａｓｓ％以上となるのが通常である。このように酸素値が高い粉末をボールミルやアトライタで偏平化した場合、十分な偏平化が進行する以前に粉砕が行われてしまい、アスペクト比が大きくとれない。これを０．０８ｍａｓｓ％以下とすることにより、アスペクト比が大きくなり、吸収特性が向上するものである。しかし、０．００１ｍａｓｓ％未満では粉砕が行われにくくなり細粒粉が得にくくなる。さらに好ましくは０．０３〜０．０６ｍａｓｓ％とする。この原料粉末の製造方法は限定するものでないが、このような低酸素品を製造する方法としてガスアトマイズ法が有効である。例えばＯ2 混合ガス（好ましくは２〜１０ｍｓｓ％の酸素混合ガス）にてガスアトマイズ法により製造する方法や水アトマイズを水素還元して酸素を低減させる等の方法もある。 The reason why the oxygen concentration of the raw material powder before flattening is 0.001 to 0.08 mass% is that the oxygen value of the raw material powder in conventional water atomization or casting-pulverization is 0.2 mass% or more. It is normal. When the powder having such a high oxygen value is flattened by a ball mill or an attritor, the powder is pulverized before sufficient flattening proceeds, and the aspect ratio cannot be increased. By setting this to 0.08 mass% or less, the aspect ratio is increased and the absorption characteristics are improved. However, if it is less than 0.001 mass%, pulverization becomes difficult and it becomes difficult to obtain fine-grained powder. More preferably, it is 0.03 to 0.06 mass%. Although the manufacturing method of this raw material powder is not limited, the gas atomization method is effective as a method for manufacturing such a low oxygen product. For example, there are a method of producing by a gas atomizing method with an O 2 mixed gas (preferably an oxygen mixed gas of 2 to 10 mass%) and a method of reducing water by hydrogen reduction of water atomized.
この偏平度と大きさは偏平加工時に決まり、これは材料の硬さが大きく影響する。硬さが大きい材料は偏平化せず、軟らかい材料は偏平化だけが進行し、粒径が大きく成り過ぎてしまう。従って、上述した金属組成は主に硬さの観点からも決定したものである。これらの金属組成において、偏平加工によりアスペクト比１０以上とする。粉末のアスペクト比（偏平度）が１０未満では、吸収特性が十分に得られず、望ましくは１０〜４０とする。粒径は細かいものが良く、その平均粒径２０〜５０μｍとする。平均粒径２０μｍ未満では細かすぎ、十分な吸収特性が得られない。 The flatness and size are determined at the time of flattening, which is greatly influenced by the hardness of the material. A material with high hardness will not be flattened, while a soft material will only flatten and the particle size will be too large. Therefore, the metal composition described above is determined mainly from the viewpoint of hardness. In these metal compositions, the aspect ratio is set to 10 or more by flattening. If the aspect ratio (flatness) of the powder is less than 10, sufficient absorption characteristics cannot be obtained, and preferably 10 to 40. The fine particle size is good, and the average particle size is 20 to 50 μm. If the average particle size is less than 20 μm, it is too fine to obtain sufficient absorption characteristics.
以下、本発明について実施例によって具体的に説明する。
表１に示す粉末組成の合金をＡｒガス（酸素を一定量混合し、粉末の酸素値を変化）アトマイズによって製造した後、−１０６μｍ分級し、偏平化処理装置であるアトライタ（媒体攪拌式粉砕機）で偏平化処理した。アトライタは縦型円筒容器中にスチール製のボールを装入し、垂直な軸により回転する攪拌アームで連続的にボールを振動させ、ボール相互の運動による粉砕作用により偏平化する手法である。この時のアトライタ処理条件としては、ボール径：φ４、ボール材質：ＳＵＪ２、回転数：２００ｒｐｍ、処理時間は平均粒径が１０〜４０μｍでアスペクト比が最も大きくなるところを選択する。また、成形条件は、粉末処理量２ｋｇに塩素化ポリエチレン（ＣＰＥ）樹脂を１０ｍａｓｓ％と微量の添加剤を６０体積％を混合し、厚さ１．０ｍｍのシート形状にロール成形を行って、シート状の電磁波吸収体を得た。その結果を表１に示す。
Hereinafter, the present invention will be specifically described with reference to examples.
An alloy having a powder composition shown in Table 1 is manufactured by atomizing an Ar gas (mixing a certain amount of oxygen and changing the oxygen value of the powder), followed by -106 μm classification, and an attritor (medium stirring mill) ) Was flattened. The attritor is a method in which a steel ball is placed in a vertical cylindrical container, the ball is continuously vibrated by a stirring arm rotated by a vertical shaft, and is flattened by a pulverizing action caused by the mutual movement of the balls. As the attritor processing conditions at this time, the ball diameter: φ4, the ball material: SUJ2, the rotation speed: 200 rpm, and the processing time are selected such that the average particle diameter is 10 to 40 μm and the aspect ratio is the largest. Also, the molding condition is that a powder processing amount of 2 kg is mixed with 10% by mass of chlorinated polyethylene (CPE) resin and 60% by volume of a small amount of additive, roll-formed into a sheet shape having a thickness of 1.0 mm, A shaped electromagnetic wave absorber was obtained. The results are shown in Table 1.
表１に示す酸素値は、原料粉末の酸素分析であり、その原料粉末を製造するためのアトマイズ時の混合酸素量を示す。また、偏平化後の粒度は、レーザー回折式粒度分布測定装置により平均粒径（ｄ５０）を測定した。また、アスペクト比は、シート断面を光学顕微鏡により観察し、その厚みと長軸長さを１００点測定し、その比の平均（長軸長さ／厚さ）を算出した。さらに、電磁波吸収特性（μ”）としては、ネットワークアナライザーで２ＧＨｚの電磁波吸収特性を測定した。 The oxygen value shown in Table 1 is an oxygen analysis of the raw material powder, and indicates the amount of mixed oxygen during atomization for producing the raw material powder. Further, the average particle size (d50) of the particle size after flattening was measured by a laser diffraction type particle size distribution measuring device. The aspect ratio was obtained by observing the sheet cross section with an optical microscope, measuring 100 thicknesses and major axis lengths, and calculating an average of the ratios (major axis length / thickness). Furthermore, as an electromagnetic wave absorption characteristic (μ ″), an electromagnetic wave absorption characteristic of 2 GHz was measured with a network analyzer.
表１に示すように、Ｎｏ．１〜８は本発明例であり、Ｎｏ．９〜１２は比較例である。比較例Ｎｏ．９は酸素値が高いために、電磁波吸収特性が悪い。Ｎｏ．１０は酸素値が低いために加工時に粉末が粗大化し平均粒径が大きく、電磁波吸収特性が悪い。Ｎｏ．１１は酸素値が高いために、加工時に粉砕が進行し過ぎて平均粒径が小さく、アスペクト比が得られず、電磁波吸収特性が悪い。Ｎｏ．１２は酸素値が低いために加工時に粉末が粗大化し平均粒径が大きく、アスペクト比が大きいために、電磁波吸収特性が悪い。これに対し、本発明Ｎｏ．１〜８はいずれも優れた電磁波吸収特性を示していることが分かる。
特許出願人 山陽特殊製鋼株式会社
代理人 弁理士 椎 名 彊
As shown in Table 1, no. 1-8 are examples of the present invention. 9 to 12 are comparative examples. Comparative Example No. Since No. 9 has a high oxygen value, it has poor electromagnetic wave absorption characteristics. No. No. 10 has a low oxygen value, so that the powder becomes coarse during processing, the average particle size is large, and the electromagnetic wave absorption characteristics are poor. No. Since No. 11 has a high oxygen value, pulverization proceeds too much during processing, the average particle size is small, the aspect ratio cannot be obtained, and the electromagnetic wave absorption characteristics are poor. No. Since No. 12 has a low oxygen value, the powder becomes coarse during processing, the average particle size is large, and the aspect ratio is large, so that the electromagnetic wave absorption characteristics are poor. On the other hand, the present invention No. 1 to 8 all show excellent electromagnetic wave absorption characteristics.
Patent Applicant Sanyo Special Steel Co., Ltd.
Attorney: Attorney Shiina
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003359576A JP2005123531A (en) | 2003-10-20 | 2003-10-20 | Powder for electromagnetic wave absorber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003359576A JP2005123531A (en) | 2003-10-20 | 2003-10-20 | Powder for electromagnetic wave absorber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2005123531A true JP2005123531A (en) | 2005-05-12 |
| JP2005123531A5 JP2005123531A5 (en) | 2007-08-23 |
Family
ID=34615756
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2003359576A Pending JP2005123531A (en) | 2003-10-20 | 2003-10-20 | Powder for electromagnetic wave absorber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2005123531A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2117017A1 (en) | 2008-04-23 | 2009-11-11 | TDK Corporation | Flat soft magnetic material and process for its production |
| WO2014156848A1 (en) | 2013-03-29 | 2014-10-02 | パウダーテック株式会社 | Noise-suppressing composite magnetic powder |
| WO2016147943A1 (en) * | 2015-03-17 | 2016-09-22 | 山陽特殊製鋼株式会社 | Flat soft magnetic powder and production method therefor |
| US9468134B2 (en) | 2012-02-21 | 2016-10-11 | Nec Tokin Corporation | Soft magnetic powder, method of manufacturing the same, noise suppression sheet using the same, and method of manufacturing the same |
| JP2020057817A (en) * | 2020-01-06 | 2020-04-09 | 山陽特殊製鋼株式会社 | Manufacturing method of soft magnetic flat powder |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62130207A (en) * | 1985-11-29 | 1987-06-12 | Daido Steel Co Ltd | Production of metallic powder |
| JPH10330806A (en) * | 1997-06-02 | 1998-12-15 | Sanyo Special Steel Co Ltd | Production of metal powder of pseudo-spherical irregular shape |
| JP2001152211A (en) * | 1999-11-25 | 2001-06-05 | Daido Steel Co Ltd | Method for producing flat metal powder for electromagnetic wave absorber |
| JP2002158482A (en) * | 2000-11-16 | 2002-05-31 | Kitagawa Ind Co Ltd | Metallic powder for electromagnetic wave absorber, electromagnetic wave absorber, and paint |
-
2003
- 2003-10-20 JP JP2003359576A patent/JP2005123531A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62130207A (en) * | 1985-11-29 | 1987-06-12 | Daido Steel Co Ltd | Production of metallic powder |
| JPH10330806A (en) * | 1997-06-02 | 1998-12-15 | Sanyo Special Steel Co Ltd | Production of metal powder of pseudo-spherical irregular shape |
| JP2001152211A (en) * | 1999-11-25 | 2001-06-05 | Daido Steel Co Ltd | Method for producing flat metal powder for electromagnetic wave absorber |
| JP2002158482A (en) * | 2000-11-16 | 2002-05-31 | Kitagawa Ind Co Ltd | Metallic powder for electromagnetic wave absorber, electromagnetic wave absorber, and paint |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2117017A1 (en) | 2008-04-23 | 2009-11-11 | TDK Corporation | Flat soft magnetic material and process for its production |
| US8038808B2 (en) | 2008-04-23 | 2011-10-18 | Tdk Corporation | Flat soft magnetic material and process for its production |
| US9468134B2 (en) | 2012-02-21 | 2016-10-11 | Nec Tokin Corporation | Soft magnetic powder, method of manufacturing the same, noise suppression sheet using the same, and method of manufacturing the same |
| WO2014156848A1 (en) | 2013-03-29 | 2014-10-02 | パウダーテック株式会社 | Noise-suppressing composite magnetic powder |
| KR20160114734A (en) | 2013-03-29 | 2016-10-05 | 파우더테크 컴퍼니 리미티드 | Noise-suppressing composite magnetic powder |
| WO2016147943A1 (en) * | 2015-03-17 | 2016-09-22 | 山陽特殊製鋼株式会社 | Flat soft magnetic powder and production method therefor |
| JP2016174065A (en) * | 2015-03-17 | 2016-09-29 | 山陽特殊製鋼株式会社 | Flat soft magnetic powder and method for manufacturing the same |
| US10576539B2 (en) | 2015-03-17 | 2020-03-03 | Sanyo Special Steel Co., Ltd. | Flat soft magnetic powder and production method therefor |
| JP2020057817A (en) * | 2020-01-06 | 2020-04-09 | 山陽特殊製鋼株式会社 | Manufacturing method of soft magnetic flat powder |
| JP7165690B2 (en) | 2020-01-06 | 2022-11-04 | 山陽特殊製鋼株式会社 | Method for producing flat soft magnetic powder |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5617173B2 (en) | Method for producing flat soft magnetic powder and electromagnetic wave absorber | |
| WO2009054369A9 (en) | Sputtering target for magnetic recording film and method for manufacturing such sputtering target | |
| JP6738160B2 (en) | Soft magnetic flat powder and method for producing the same | |
| JP4717754B2 (en) | Flat powder for electromagnetic wave absorber and electromagnetic wave absorber | |
| KR102369149B1 (en) | Magnetic flat powder and magnetic sheet containing same | |
| JP2016072577A (en) | Soft magnetic flat powder and method for manufacturing the same | |
| JP2014204051A (en) | Soft magnetic flat-particle powder, and magnetic sheet arranged by use thereof | |
| JP2005123531A (en) | Powder for electromagnetic wave absorber | |
| JP6955685B2 (en) | Soft magnetic metal powder and its manufacturing method | |
| KR102393236B1 (en) | soft magnetic flat powder | |
| JP2003332113A (en) | Flat soft magnetic powder and composite magnetic sheet using the same | |
| JP4209614B2 (en) | Ni-Fe alloy powder | |
| JP2018131640A (en) | Soft magnetic flat powder | |
| JP2009114505A (en) | Magnetite-iron composite powder and its manufacturing method | |
| JP4304668B2 (en) | Metal fine particles and method for producing metal fine particles | |
| JP7257150B2 (en) | Flame-retardant powder for magnetic components | |
| JP2007009288A (en) | Soft magnetic alloy powder | |
| JP2002344192A (en) | Composite powder for radio wave absorber | |
| JP2005240138A (en) | Soft magnetic metal powder, composite insulating magnetic composition and electronic component | |
| JP2002134309A (en) | Method for manufacturing electromagnetic wave absorbent powder | |
| JP6738502B2 (en) | Method for producing soft magnetic flat powder | |
| JP7133666B2 (en) | Soft magnetic flat powder | |
| JP7277076B2 (en) | Powder for magnetic parts | |
| CN102744398A (en) | Porous iron powder, process for producing the same and radio wave absorber | |
| JP2020152997A (en) | Iron-based soft magnetic powder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20060308 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070710 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20080827 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080909 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20090203 |