JP4309558B2 - Electromagnetic interference suppressor - Google Patents

Description

【００３７】
垂直燃焼試験は、試験片を５本用いて行うが、表１の第１残炎の欄には、１回目の接炎後の燃焼時間（秒）を、第２残炎の欄には、２回目の接炎後の燃焼時間（秒）を、第２残炎＋火種の欄には、２回目の接炎後の燃焼時間と火種時間の合計時間（秒）を記載した。ここで火種時間とは、有炎燃焼が停止してから、または有炎燃焼が生じない場合の材料の無炎燃焼を続ける時間をいう。
【００３８】
表１によれば、実施例1では各試験片の燃焼時間がすべて３秒以下であり、また全１０回の接炎後の残炎時間合計が１６秒である。実施例１は、表面に一定の厚みの酸化被膜を設けた軟磁性粉末を用いたものであり、Ｖ−０クラスの規格５０秒以下を満足した。これに対し、比較例１は全１０回の接炎後の残炎時間合計が４７秒であるが、試験片Ｎｏ.４の第1接炎が１０秒を越えていて、難燃規格ＵＬ９４Ｖ−１クラスに相当する。
【００３９】
（実施例２）
次に、第２の実施例について説明する。本実施例では、軟磁性粉末としてＦｅ−Ｓｉ−Ａｌ合金粉末を用いた。これは略球状粉末で、表面に厚みが５.０×１０^−１０ｍ以上１.２×１０^−９ｍ以下の範囲で窒化物被膜が形成されている。また、他の原材料及びその混合比率は、第１の実施例と同一とした。なお、製造工程も第１の実施例と同様に行い、複合磁性体を得た。更に第１の実施例と同様にして、難燃性を評価した。
【００４０】
本実施例の燃焼試験結果は、第１の実施例とともに表１に示した。
【００４１】
表１によると、各試験片の燃焼時間は、すべて３秒以下であり、また全１０回の接炎後の残炎時間の合計が２０秒である。これはＶ−０クラスの規格５０秒以下を満足し、軟磁性粉末の表面に一定厚みの窒化被膜を設けることによって、複合磁性体に自己消火性を付与することができた。
【００４２】
（実施例３）
次に、第３の実施例について説明する。本実施例では、軟磁性粉末としてＦｅ−Ｓｉ−Ａｌ合金粉末を用いた。これは形状が球状であり、粉末の比表面積が１.０×１０^−１ｍ^２／ｇ、酸化物層の厚みが１.２×１０^−９ｍである。即ち、単位重量あたりの酸化物層の体積は、１.２×１０^−１０ｍ^３／ｇである。この軟磁性粉末の酸化物層の調製法は、第１の実施例と同様である。
【００４３】
この粉末を用いて、第１の実施例と同様に複合磁性体用の混和物を得、燃焼試験用の試験片を作製して難燃性の評価を行った。但し、試験片の厚みは１.０ｍｍとした。また、比較に供するため、第２の比較例として、オーブンで酸化処理を施す前の、表面の酸化物層の平均厚みが４.０×１０ ^-10 ｍの軟磁性粉末を用いた複合磁性体についても同様に評価を行った。表２はその結果を示したものである。
【００４４】
【表２】

【００４５】
この結果によると、本実施例では各試験片とも、燃焼時間がすべて１０秒以下であり、また全１０回残炎時間の合計が２３秒と規格値の５０秒以下を満足する。よって、Ｖ−０クラスの規格を満足した。これに対して、第２の比較例では、各試験片の１回目のまたは、２回目の接炎後の残炎時間が、Ｖ−１の規格値の３０秒以下で、全１０回の接炎後の残炎時間の合計が７９秒であり、Ｖ−１の規格値の２５０秒以下である。従って、第２の比較例は、Ｖ−１クラスに相当する。
【００４６】
（実施例４）
次に、第４の実施例について説明する。本実施例では、軟磁性粉末として、表面に窒化物の被膜を有するＦｅ−Ｓｉ−Ａｌ合金粉末を用いた。これは形状が球状であり、粉末の比表面積と窒化物層の厚みの積、即ち単位重量あたりの窒化物層の体積は、１.０×１０^−１０ｍ^３／ｇ以上１.４×１０^−１０ｍ^３／ｇ以下の範囲に分布している。この粉末を用い、第３の実施例と同様にして複合磁性体用の混和物を得、燃焼試験用の試験片を作製して難燃性の評価を行った。
【００４７】
燃焼試験の結果を、第３の実施例とともに表２に示した。これによると、各試験片の燃焼時間がすべて１０秒以下であり、また全１０回の接炎後の残炎時間の合計が３４秒である。これは、Ｖ−０クラスの規格である５０秒以下を満足し、軟磁性粉末の比表面積と窒化物層の厚みを一定値とすることによって、自己消火性を付与することができた。
【００４８】
（実施例５）
次に、第５の実施例について説明する。本実施例では、軟磁性粉末として、ミルで粉砕したアスペクト比が３以上である扁平形状のＦｅ−Ｓｉ−Ａｌ合金を用いた。この粉末の表面には、厚みが１.５×１０^−９ｍの酸化物層が設けてあるが、これは、表面の酸化物層の厚みが４×１０^−１０ｍの軟磁性粉末を、オーブンを用いて６５０℃で１５分間、大気中で加熱処理して調製したものである。
【００４９】
この軟磁性粉末を用い、他の原材料及びその混合比率は、第１の実施例と同一とし、製造工程も第１の実施例と同様に行い、複合磁性体を得た。更に、第１の実施例と同様にして、難燃性を評価した。この結果を表３に示した。
【００５０】
【表３】

【００５１】
（実施例６）
次に、第６の実施例について説明する。第５の実施例と同様の方法で、アスペクト比が３以上、比表面積が０.６ｍ^２／ｇ、酸化物層の厚みが１.５×１０^−９ｍのＦｅ−Ｓｉ−Ａｌ合金からなる軟磁性粉末を調製した。つまり、この粉末の非表面積と酸化物層の厚みの積は、９.０×１０^−１０ｍ^３／ｇである。
【００５２】
この軟磁性粉末を用い、他の原材料及びその混合比率は、第１の実施例と同一とし、製造工程も第１の実施例と同様に行い、複合磁性体を得た。更に、第１の実施例と同様にして、難燃性を評価した。この結果を第５の実施例とともに表３に示した。
【００５３】
また、第５の実施例と第６の実施例との比較に供するために、アスペクト比が３以上で、比表面積と酸化物層の厚みの積が２.４×１０^−１０ｍ^３／ｇの軟磁性粉末を調製した。これについても、第１の実施例と同様にして、難燃性を評価した。この結果を第３の比較例として、第５の実施例、第６の実施例とともに表３に示した。
【００５４】
表３の結果から明らかなように、第５の実施例及び第６の実施例の複合磁性体は、Ｖ−０クラスの難燃性を有し、第３の比較例の複合磁性体は、Ｖ−１クラスの難燃性を有することが分かる。従って、軟磁性粉末表面の酸化物層の厚みと、軟磁性粉末の比表面積と酸化物層の厚みの積とを限定することにより、複合磁性体の難燃性を確保できることが確認できた。
【００５５】
（実施例７）
次に、第７の実施例として、軟磁性粉末にカップリング剤で表面処理を施して、混和物の混練性を向上する例を説明する。第５の実施例に用いたＦｅ−Ｓｉ−Ａｌ合金の軟磁性粉末３８５重量部に対し、チタネート系カップリング剤４重量部を加え、ミキサーで攪拌して表面処理を施した。この軟磁性粉末３８９重量部と、臭素系ポリマー難燃剤２０重量部と、さらに難燃助剤の三酸化アンチモン２０重量部とを、前記の実施例と同様な方法で混練することにより、複合磁性体用の混和物を得た。
【００５６】
これまでに説明した例では、均一な混和物を得るのに、混練に６０分間を要したが、本実施例では、混練時間が５０分間に短縮できた。これは、表面処理により、軟磁性粉末の結合剤への充填性が向上したためと解される。
【００５７】
また、本実施例では、シートの成形性においても改善が認められ、第５の実施例では、０.５ｍｍのシートを得るのに、複合磁性体をロールに４回通す必要があったが、本実施例では３回で所要の厚みを得ることができた。
【００５８】
また、本実施例で得られた複合磁性体についても、これまでに説明した実施例と同様に難燃性を評価した。この結果を表４に示した。
【００５９】
【表４】

【００６０】
表４によると、本実施例は、全１０回の接炎後の残炎時間の合計が１５秒で、Ｖ−０クラスに相当する。また第５の実施例に比較すると残炎時間の合計が７秒短くなり、かつ試験片の燃焼時間の差も少なくなっている。
【００６１】
（実施例８）
また、第８の実施例として、非表面積と酸化物層の厚みの積を限定した、Ｆｅ−Ｓｉ−Ａｌ合金粉末にカップリング剤で表面処理を施した例について説明する。第６の実施例で用いた、非表面積と酸化物層の厚みの積が９.０×１０^−１０ｍ^３／ｇであるＦｅ−Ｓｉ−Ａｌ合金粉末を、第７の実施例と同様にして表面処理、及び結合剤、難燃剤、難燃助剤と混練して複合磁性体用の混和物を得た。この場合も第７の実施例と同様に、混練性及び成形性が向上するという効果が認められた。
【００６２】
また、本実施例で得られた複合磁性体についても、これまでに説明した実施例と同様に難燃性を評価した。この結果を表５に示した。
【００６３】
【表５】

【００６４】
表５によると、本実施例は、全１０回の接炎後の残炎時間の合計が２５秒で、Ｖ−０クラスに相当する。また第６の実施例に比較すると残炎時間の合計が５秒短くなり、かつ試験片の燃焼時間の差も第７の実施例と同様に少なくなっている。
【００６５】
（実施例９）
次に、第９の実施例として、軟磁性粉末として、アスペクト比が３以上である扁平形状のパーマロイ粉末（Ｆｅ−Ｎｉ合金粉末）にカップリング剤で表面処理を施した例について説明する。まず、粉末表面に、酸化物層の厚みが、５×１０^−１０ｍ以上１×１０^−７ｍ以下の間に分布するように、酸化処理を施した。この軟磁性粉末を用い、第７の実施例、第８の実施例と同様にして複合磁性体を得、難燃性を評価したところ、Ｖ−０クラスの難燃性を有することが確認できた。
【００６６】
（実施例１０）
また、第１０の実施例として、第９の実施例に用いた軟磁性粉末を用いて、比表面積と厚みの積が限定された酸化物層を有する粉末に、カップリング剤で表面処理した例を説明する。ここでは、粉末の比表面積と厚みの積が５.０×１０^−１３ｍ^３／ｇ以上１.５×１０^−９ｍ^３／ｇ以下の範囲となるように、表面に酸化処理を施した。この軟磁性粉末にカップリング剤で表面処理を施し、第７の実施例、第８の実施例と同様にして複合磁性体を得、難燃性を評価したところ、Ｖ−０クラスの難燃性を有することが確認できた。
【００６７】
（実施例１１）
次に、第１１の実施例として、軟磁性粉末の表面処理にプライマー剤を用いた例について説明する。ここでは、プライマー剤としてエポキシ系のポリマーを用い、軟磁性粉末表面を被覆した。このプライマー剤の溶解度パラメータは２２であり、結合剤である塩素化ポリエチレンとほぼ同じである。なお、ここで使用している溶解度パラメータの数値の単位はＭＰａ^１／２である。
【００６８】
軟磁性粉末としてアスペクト比が３以上、比表面積が０.６ｍ^２／ｇ、酸化物層の厚みが１.５×１０^−９ｍのＦｅ−Ｓｉ−Ａｌ合金を用い、第１の実施例と同様に原材料の混練とシート成形を行った。その結果、この場合も第７の実施例、第８の実施例と同様に、混練性及び成形性が向上するという効果が認められた。
【００６９】
また、本実施例で得られた複合磁性体についても、これまでに説明した実施例と同様に難燃性を評価した。この結果を表６に示した。
【００７０】
【表６】

【００７１】
表６によると、本実施例は、全１０回の接炎後の残炎時間の合計が１６秒で、Ｖ−０クラスに相当する。また第５の実施例に比較すると残炎時間の合計が６秒短くなり、かつ試験片毎の燃焼時間の差も少なくなっている。
【００７２】
これは、軟磁性粉末の表面に一定の厚みを有する酸化物層が付与し、かつ軟磁性粉末に表面処理を施したことにより、分散性が向上したために、難燃性が向上するとともにばらつきも低減したものと解される。
【００７３】
（実施例１２）
また、第１２の実施例として、比表面積と厚みの積が限定された酸化物層を有する粉末に、プライマー剤で表面処理した例を説明する。軟磁性粉末として、アスペクト比が３以上で、比表面積と酸化物層の厚みの積が９.０×１０ ^-10 ｍ ³ ／ｇのＦｅ−Ｓｉ−Ａｌ合金粉末を準備した。この粉末を用い、第１１の実施例とまったく同様にして、粉末の表面処理、混練、シート成形を行った。その結果、この場合も第７の実施例、第８の実施例と同様に、混練性及び成形性が向上するという効果が認められた。
【００７４】
また、本実施例で得られた複合磁性体についても、これまでに説明した実施例と同様に難燃性を評価した。この結果を表７に示した。
【００７５】
【表７】

【００７６】
これによると、本実施例は、全１０回の接炎後の残炎時間の合計が２７秒で、Ｖ−０クラスに相当する。また、第６の実施例に比較すると残炎時間の合計が６秒短くなり、かつ試験片毎の燃焼時間の差も少なくなっていて、第１１の実施例と同様の結果が得られた。
【００７７】
（実施例１３）
次に、難燃剤と可塑剤の機能を併せ持つリン酸エステル化合物を用いた例について説明する。ここでは、軟磁性粉末として、アスペクト比が３以上で、表面の酸化物層の厚みが１.５×１０^−９ｍであるＦｅ−Ｓｉ−Ａｌ合金粉末を用いた。まず、この粉末３８５重量部に対し、チタネート系カップリング剤４重量部を用いて表面処理を施した。
【００７８】
この軟磁性粉末を３８９重量部、トリクレジルフォスフェートを４重量部、それぞれ秤量して、ミキサーで均一になるまで混合した。この操作は、カップリング剤による表面処理と同時に行ってもよい。次に、前記混合物を３９３重量部、塩素化ポリエチレンを１００重量部、臭素系ポリマー難燃剤を２０重量部、三酸化アンチモンを２０重量部、加圧ニーダーに投入して均一になるまで混練した。なお、ここで用いたトリクレジルフォスフェートの溶解度パラメータは１７.２である。
【００７９】
この混和物を用い、これまでに述べた実施例と同様に、シート成形と難燃性の評価を行った。表８は、難燃性の評価結果を示したものである。
【００８０】
【表８】

【００８１】
表８によると、全１０回の接炎後の残炎時間の合計が２１秒で、Ｖ−０クラスに相当する。またこの場合も各試験片の燃焼時間の差が少なく、難燃性のばらつきが減少していることが分かる。
【００８２】
また、同じくリン酸エステル化合物で、かつ溶解度パラメータが１４〜２５の範囲である、イソプロピルトリアリールフォスフェート、クレジルジフェニルフォスフェートを用いても同様の結果が得られた。
【００８３】
（実施例１４）
また、第１４の実施例として、比表面積と厚みの積が限定された酸化物層を有する軟磁性粉末を用い、第１３の実施例とまったく同一の方法で、表面処理、混練、シート成形を行った例を示す。ここでは、軟磁性粉末として、アスペクト比が３以上で、比表面積と酸化物層の厚みの積が９.０×１０ ^-10 ｍ ³ ／ｇのＦｅ−Ｓｉ−Ａｌ合金粉末を用いた。表９に、本実施例による複合磁性体の難燃性の評価結果を示す。この場合も第１３の実施例と同様に、難燃性の向上とばらつきの減少が認められた。
【００８４】
【表９】

【００８５】
（実施例１５）
次に、第１５の実施例として、リン系難燃剤の添加により難燃性の向上が認められたので、他の難燃剤を減少した例を説明する。まず、軟磁性粉末として、アスペクト比が３以上で、表面の酸化物層の厚みが１.５×１０^−９ｍであるＦｅ−Ｓｉ−Ａｌ合金粉末を準備し、この粉末３８５重量部に対し、チタネート系カップリング剤４重量部を用いて表面処理を施した。
【００８６】
次に、表面処理済の軟磁性粉末３８９重量部とトリクレジルフォスフェート４重量部をミキサーで混合した。この操作は、カップリング剤による表面処理と同時に行ってもよい。次に、前記混合物を３９３重量部、臭素系難燃剤を１４重量部、三酸化アンチモンを１４重量部、それぞれ秤量して加圧ニーダーに投入し、均一になるまで混練した。臭素系難燃剤と三酸化アンチモンは、これまで説明した実施例に比較して、それぞれ２０重量部から１４重量部に減らしている。
【００８７】
得られた複合磁性体について、これまでに説明した実施例と同様にして難燃性を評価した。表１０は、その結果を示したものである。
【００８８】
【表１０】

【００８９】
本実施例では、臭素系難燃剤と三酸化アンチモンをそれぞれ３０％減少したにも拘らず、全１０回の接炎の残炎時間の合計が２７秒であり、Ｖ−０クラスの難燃性を確保できた。これは、表面の酸化被膜の厚みを限定したこと、カップリング剤で表面処理を行ったこと、更にリン系難燃剤を分散させたことの相乗効果によると解される。
【００９０】
（実施例１６）
また、第１６の実施例として、比表面積と厚みの積が限定された酸化物層を有する軟磁性粉末を用い、第１５の実施例とまったく同一の方法で、表面処理、混練、シート成形を行った例を示す。ここでは、軟磁性粉末として、アスペクト比が３以上で、比表面積と酸化物層の厚みの積が９.０×１０ ^-10 ｍ ³ ／ｇのＦｅ−Ｓｉ−Ａｌ合金粉末を用いた。表１１に、本実施例による複合磁性体の難燃性の評価結果を示す。
【００９１】
【表１１】

【００９２】
表１１から明らかなように、本実施例においても、リン系難燃剤を添加したことによって、臭素系難燃剤と三酸化アンチモンをそれぞれ３０％減少したにも拘らず、全１０回の接炎の残炎時間の合計が３６秒であり、Ｖ−０クラスの難燃性を確保できた。この結果から、軟磁性粉末の表面処理の条件に拘らず、リン系難燃剤の添加が一定の効果を示すことが確認できた。
【００９３】
【発明の効果】
以上に詳しく説明したように、本発明によれば、表面に酸化被膜を有する軟磁性粉末の酸化物層の厚みと、軟磁性粉末の比表面積と酸化物層の厚みの積とを一定範囲に限定することにより、難燃性に優れた複合磁性体および電磁干渉抑制体が得られる。また、本発明によれば、表面に窒化被膜を有する軟磁性粉末の窒化物層の厚みと、軟磁性粉末の比表面積と窒化物層の厚みの積とを一定範囲に限定することにより、難燃性に優れた複合磁性体および電磁干渉抑制体が得られる。
【００９４】
更に、本発明によれば、溶解度パラメータが結合剤とほぼ同じである表面処理剤で、粉末表面に表面処理を施したり、溶解度パラメータが結合剤とほぼ同じであるリン系難燃剤を添加したりすることで、複合磁性体を構成する各成分の分散性を向上することにより、混練性や成形性の向上、ひいては難燃性の向上やそのばらつきの低減にも寄与することができる。
【００９５】
なお、これまでに説明した実施例における複合磁性体は、電気機器の内部及び周辺部で使用することによって、不要電波の干渉によって生じる電磁障害を抑制する電磁干渉抑制体として機能することは勿論である。
【図面の簡単な説明】
【図１】本発明による複合磁性体の模式図。
【符号の説明】
１０ 複合磁性体
１１ 軟磁性粉末
１２ 結合剤
１３ 難燃剤
１４ 難燃助剤[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite magnetic body used for suppressing electromagnetic interference caused by interference of unnecessary electromagnetic waves in a high frequency region, and an electromagnetic interference suppressor using the composite magnetic body, and particularly to a flame retarding technique for a composite magnetic body. is there.
[0002]
[Prior art]
In recent years, electronic devices using a high frequency, such as mobile phones and personal computers, have become widespread. For these devices, there is a significant demand for miniaturization and weight reduction, and an increase in calculation processing speed causes a problem of electromagnetic noise interference. Therefore, composite magnetic bodies and electromagnetic interference suppressors using the same have been commercialized as measures against such high-frequency electromagnetic interference.
[0003]
On the other hand, many recent electronic devices have built-in circuits that generate heat, such as a CPU, a power supply circuit, and a high-voltage circuit, and the devices have been downsized. The risk of fire due to is becoming more difficult to ignore. For this reason, the parts to be used are required to ensure self-extinguishing properties, which are the main element of flame retardancy.
[0004]
Therefore, it is necessary to ensure flame retardancy equivalent to UL94V-0 or UL94V-1 of the US UL standard in case of an electronic device fire. For example, a coating material such as an electric wire or a housing of an electronic device uses a halogen-based flame retardant as a flame retardant formulation and antimony trioxide as a flame retardant aid. These are the most common methods.
[0005]
However, in the case of a composite magnetic body and an electromagnetic interference suppressor using the same, it is very difficult to ensure flame retardancy. The main factor is a phenomenon in which the soft magnetic alloy powder, which is one of the constituent materials, has an action of improving catalytic action and thermal conductivity, thereby further promoting combustion.
[0006]
Therefore, conventionally, various flame retardant compounding recipes have been devised, and the flame retardant properties have been secured by increasing the compounding amount. By the way, the so-called decabro flame retardant represented by decabromodiphenyl oxide, which is said to have a high flame retardant effect, has not been clarified yet, but there are concerns about its impact on the environment, There were restrictions.
[0007]
Also, when using the soft magnetic powder in the production of a composite magnetic body, the same kind of soft magnetic powder is used, and even if the particle size of the powder is the same, there is a difference in the flame retardancy, that is, the combustion test result was there.
[0008]
Furthermore, the kneading process that uniformly disperses soft magnetic powders and flame retardants in the binder, which is one of the manufacturing processes of the composite magnetic material, is a technically very difficult task. Although the composite magnetic material produced in (1) satisfied the flame retardant standard, there was a problem in that the combustion test results varied. Therefore, the blending amount of the flame retardant is set to be larger than the necessary minimum amount. And there is a problem that increasing the flame retardant leads to deterioration of various properties of the composite magnetic body.
[0009]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to improve the characteristics of the composite magnetic body by ensuring the flame retardancy of the composite magnetic body without causing variations in the combustion test and minimizing the amount of flame retardant added. And to reduce the manufacturing cost.
[0010]
Another object of the present invention is to provide a composite magnetic body and an electromagnetic interference suppressor that improve the uniformity and formability of a mixture comprising a soft magnetic powder, a binder, and a flame retardant while considering the above problems. It is to provide.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention prevents the soft magnetic powder from promoting the combustion of the composite magnetic material by forming an oxide film or a nitride film on the surface of the soft magnetic powder, and uses each component. By adjusting the solubility parameter, the affinity of each component is increased and the properties such as moldability are improved.
[0012]
  That is, the present invention provides a soft magnetic powder having an oxide film on the surface and, Binder, flame retardant, flame retardant aidElectromagnetic interference suppressor using composite magnetic material consisting ofBecauseThe thickness of the oxide layer of the soft magnetic powder is 5 × 10^-Tenm or more 1 × 10^-7The product of the specific surface area of the soft magnetic powder and the thickness of the oxide layer of the soft magnetic powder, that is, the volume of the oxide layer per unit weight is 1.2 × 10.^-Tenm^Three/ G or more 3 × 10^-7m^ThreeIt is an electromagnetic interference suppressor characterized by being in the range of not more than / g.
[0014]
  The present invention also provides a soft magnetic powder having a nitride film on the surface and, Binder, flame retardant, flame retardant aidElectromagnetic interference suppressor using composite magnetic material consisting ofBecauseThe thickness of the nitride layer of the soft magnetic powder is 5 × 10^-Tenm or more 1 × 10^-7The product of the specific surface area of the soft magnetic powder and the thickness of the nitride layer of the soft magnetic powder, that is, the volume of the nitride layer per unit weight is 1.0 × 10.^-Tenm^Three/ G or more 3 × 10^-7m^ThreeIt is an electromagnetic interference suppressor characterized by being in the range of not more than / g.
[0016]
  Further, the present invention provides the above-mentionedElectromagnetic interference suppressorWherein the soft magnetic powder has a flat shape and an aspect ratio of 3 or more.Electromagnetic interference suppressorIt is.
[0017]
  Further, the present invention provides the above-mentionedElectromagnetic interference suppressorThe soft magnetic powder is surface-treated with at least one coupling agent among titanate, silane, and aluminum coupling agents.Electromagnetic interference suppressorIt is.
[0018]
  Further, the present invention provides the above-mentionedElectromagnetic interference suppressorWherein the soft magnetic powder is surface-treated with a primer agent having a solubility parameter that is within 10 differences from the solubility parameter of the binder.Electromagnetic interference suppressorIt is.
[0019]
  Further, the present invention provides the above-mentionedElectromagnetic interference suppressorIn the present invention, a phosphorus-based flame retardant having a solubility parameter in the range of 14 to 25 is dispersed in the binder.Electromagnetic interference suppressorIt is.
[0020]
  Further, the present invention provides the above-mentionedElectromagnetic interference suppressorThe soft magnetic powder is composed of an alloy powder containing at least Fe and Si.Electromagnetic interference suppressorIt is.
[0021]
  Further, the present invention provides the above-mentionedElectromagnetic interference suppressorWherein the soft magnetic powder is made of an alloy powder containing at least Ni and Fe.Electromagnetic interference suppressorIt is.
[0023]
[Action]
In the composite magnetic body according to the present invention, an oxide film or nitride film having a certain thickness is formed on the surface of the soft magnetic powder. For this reason, there is no contact between the metal and the binder, and the catalytic action and heat transfer action of the metal are less likely to reach the binder.
[0024]
In general, substances having similar solubility parameter values have a high affinity. However, in the composite magnetic material according to the present invention, the surface of the soft magnetic powder is surface-treated with a primer or a coupling agent. The surface solubility parameter is close to the binder. Thereby, the dispersibility of the soft magnetic powder in the binder can be improved.
[0025]
Furthermore, in the composite magnetic body according to the present invention, by adjusting the solubility parameter of the flame retardant, the dispersibility of the flame retardant in the binder can be improved, and variations in the combustion test can be reduced. In the present invention, the thickness of the oxide layer or nitride layer on the surface of the soft magnetic powder and the product of the thickness and the specific surface area of the soft magnetic powder are limited. In this range, the volume of the soft magnetic powder becomes relatively insufficient, and the effect as an electromagnetic interference suppressor cannot be sufficiently exhibited.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with specific examples. Note that the composite magnetic body functions as an electromagnetic interference suppressor that suppresses electromagnetic interference caused by interference of unnecessary electromagnetic waves when it is used in and around electrical equipment.
[0027]
Therefore, in the present embodiment, the composite magnetic body is treated as if the composition described below is obtained by the following method, and the obtained composite magnetic body is used in and around an electric device or the like. In this case, it will be called an electromagnetic interference suppressor. That is, the composite magnetic body and the electromagnetic interference suppressor are described as different expressions because they are the same when paying attention to the constituent components and the manufacturing process, but are different when paying attention to the application. For the above reasons, the names of the composite magnetic body and the electromagnetic interference suppressor are used differently hereinafter.
[0028]
FIG. 1 is a schematic cross-sectional view of a composite magnetic body 10 according to the present invention. The composite magnetic body 10 is composed of a soft magnetic powder 11 whose surface is covered with an oxide layer or a nitride layer having a defined thickness, a binder 12, a flame retardant 13, and a flame retardant aid 14.
[0029]
【Example】
    Example 1
  First, a first embodiment of the present invention will be described. Fe-Si-Al alloy powder was prepared as soft magnetic powder. The shape of this powder is approximately spherical, and the thickness of the oxide layer on the surface is 1.2 × 10^-9m. Here, this powder has an average thickness of the oxide layer.4.0 × 10 ^-Ten The powder of m was prepared by heating in the atmosphere using an oven at a temperature of 650 ° C. for 15 minutes. Further, even if the temperature was changed to 600 ° C., 700 ° C., etc., and the time for the change was controlled variously, it could be produced similarly. Note that the surface oxide layer is not limited to this method.
[0030]
The composition of this powder is 6-11% by weight of Si, 4-7% by weight of Al, and the balance is Fe. The soft magnetic powder may be Fe-Si-Al-Ni based composition.
[0031]
Next, the manufacturing process of a present Example is demonstrated. First, 100 parts by weight of chlorinated polyethylene as a binder, 385 parts by weight of soft magnetic powder, 20 parts by weight of a brominated polymer flame retardant as a flame retardant, and function as a flame retardant aid for brominated flame retardants 20 parts by weight of antimony trioxide was weighed. This was put into a pressure kneader and kneaded until uniform to obtain an admixture for a composite magnetic body.
[0032]
In addition, as the kneader, an intensive mixer or a mixing roll for kneading may be used, and an equivalent mixture can be obtained. In addition, in order to improve the dispersibility of each component in the mixture and shorten the mixing time, soft magnetic powder, bromine-based polymer flame retardant, and flame retardant auxiliary antimony trioxide may be mixed in advance with a mixer.
[0033]
Next, the obtained mixture was rolled through rolls arranged in parallel and formed into a sheet shape. For comparison with the present example, a composite magnetic material sheet was prepared by the same method as described above using the powder before being subjected to the oxidation treatment in an oven, and used as a first comparative example. In order to obtain a sheet-like composite magnetic body, extrusion molding or press molding may be used in addition to roll molding.
[0034]
As described above, by using the composite magnetic body manufactured by the above method in the inside and the peripheral part of an electric device or the like, the composite magnetic body suppresses electromagnetic interference caused by interference of unnecessary electromagnetic waves. Functions as a body.
[0035]
Although the flame retardancy was evaluated for these composite magnetic bodies, the use of the composite magnetic body is often an electronic component, so the UL standard, which is a standard for the safety of plastic materials for parts of electrical and electronic equipment, is used here. The vertical combustion test UL94V was conducted according to the above. The test piece has a length of 127 mm, a width of 12.7 mm, and a thickness of 0.5 mm. The results are shown in Table 1.
[0036]
[Table 1]

[0037]
The vertical combustion test is performed using five test pieces. In the column of the first after flame in Table 1, the combustion time (seconds) after the first flame contact is shown, and in the column of the second after flame, The combustion time (seconds) after the second flame contact is shown in the second residual flame + fire type column, and the total time (seconds) of the combustion time and the fire time after the second flame contact is described. Here, the fire type time refers to the time during which the flameless combustion of the material is continued after the flammable combustion stops or when the flammable combustion does not occur.
[0038]
According to Table 1, in Example 1, the burning time of each test piece is all 3 seconds or less, and the total afterflame time after all 10 flame contact is 16 seconds. In Example 1, soft magnetic powder having an oxide film with a constant thickness on the surface was used, and V-0 class standard of 50 seconds or less was satisfied. On the other hand, in Comparative Example 1, the total afterflame time after 10 times of flame contact was 47 seconds, but the first flame contact of test piece No. 4 exceeded 10 seconds, and the flame retardant standard UL94V- It corresponds to one class.
[0039]
(Example 2)
Next, a second embodiment will be described. In this example, Fe—Si—Al alloy powder was used as the soft magnetic powder. This is a roughly spherical powder with a surface thickness of 5.0 × 10^-10m or more 1.2 × 10^-9A nitride film is formed in a range of m or less. The other raw materials and the mixing ratio thereof were the same as those in the first example. The manufacturing process was also performed in the same manner as in the first example to obtain a composite magnetic body. Furthermore, the flame retardancy was evaluated in the same manner as in the first example.
[0040]
The combustion test result of this example is shown in Table 1 together with the first example.
[0041]
According to Table 1, the burning time of each test piece is all 3 seconds or less, and the total afterflame time after all 10 flame contact is 20 seconds. This satisfied the V-0 class standard of 50 seconds or less, and a self-extinguishing property could be imparted to the composite magnetic body by providing a nitride film having a certain thickness on the surface of the soft magnetic powder.
[0042]
(Example 3)
Next, a third embodiment will be described. In this example, Fe—Si—Al alloy powder was used as the soft magnetic powder. This is spherical in shape and the specific surface area of the powder is 1.0 × 10^-1m²/ G, the thickness of the oxide layer is 1.2 × 10^-9m. That is, the volume of the oxide layer per unit weight is 1.2 × 10^-10m³/ G. The method for preparing the oxide layer of this soft magnetic powder is the same as in the first embodiment.
[0043]
  Using this powder, an admixture for a composite magnetic material was obtained in the same manner as in the first example, and a test piece for a combustion test was prepared to evaluate flame retardancy. However, the thickness of the test piece was 1.0 mm. In addition, for comparison, as a second comparative example, the average thickness of the oxide layer on the surface before being oxidized in the oven is4.0 × 10 ^-Ten A composite magnetic body using m soft magnetic powder was also evaluated in the same manner. Table 2 shows the results.
[0044]
[Table 2]

[0045]
According to this result, in each of the test pieces in this example, the combustion time is all 10 seconds or less, and the total of all 10 afterflame times is 23 seconds, which satisfies the standard value of 50 seconds or less. Therefore, the standard of V-0 class was satisfied. On the other hand, in the second comparative example, the afterflame time after the first or second flame contact of each test piece is 30 seconds or less of the standard value of V-1, and all the ten contact times. The total after flame time after the flame is 79 seconds, which is 250 seconds or less of the standard value of V-1. Therefore, the second comparative example corresponds to the V-1 class.
[0046]
(Example 4)
Next, a fourth embodiment will be described. In this example, Fe-Si-Al alloy powder having a nitride film on its surface was used as the soft magnetic powder. This is spherical in shape, and the product of the specific surface area of the powder and the thickness of the nitride layer, that is, the volume of the nitride layer per unit weight is 1.0 × 10^-10m³/ G or more 1.4 × 10^-10m³/ G or less. Using this powder, an admixture for a composite magnetic material was obtained in the same manner as in the third example, and a test piece for a combustion test was prepared to evaluate flame retardancy.
[0047]
The results of the combustion test are shown in Table 2 together with the third example. According to this, all the burning times of each test piece are 10 seconds or less, and the total afterflame time after all 10 times of flame contact is 34 seconds. This satisfied the V-0 class standard of 50 seconds or less, and self-extinguishing properties could be imparted by setting the specific surface area of the soft magnetic powder and the thickness of the nitride layer to constant values.
[0048]
(Example 5)
Next, a fifth embodiment will be described. In this example, a flat Fe-Si-Al alloy having an aspect ratio of 3 or more pulverized by a mill was used as the soft magnetic powder. The surface of this powder has a thickness of 1.5 × 10^-9m oxide layer is provided. The thickness of the oxide layer on the surface is 4 × 10^-10m soft magnetic powder was prepared by heat treatment in the atmosphere at 650 ° C. for 15 minutes using an oven.
[0049]
Using this soft magnetic powder, the other raw materials and the mixing ratio thereof were the same as in the first example, and the manufacturing process was performed in the same manner as in the first example to obtain a composite magnetic body. Furthermore, the flame retardancy was evaluated in the same manner as in the first example. The results are shown in Table 3.
[0050]
[Table 3]

[0051]
(Example 6)
Next, a sixth embodiment will be described. In the same manner as in the fifth embodiment, the aspect ratio is 3 or more and the specific surface area is 0.6 m.²/ G, the thickness of the oxide layer is 1.5 × 10^-9A soft magnetic powder made of m Fe—Si—Al alloy was prepared. That is, the product of the non-surface area of this powder and the thickness of the oxide layer is 9.0 × 10^-10m³/ G.
[0052]
Using this soft magnetic powder, the other raw materials and the mixing ratio thereof were the same as in the first example, and the manufacturing process was performed in the same manner as in the first example to obtain a composite magnetic body. Furthermore, the flame retardancy was evaluated in the same manner as in the first example. The results are shown in Table 3 together with the fifth example.
[0053]
For comparison with the fifth and sixth embodiments, the aspect ratio is 3 or more, and the product of the specific surface area and the thickness of the oxide layer is 2.4 × 10.^-10m³/ G soft magnetic powder was prepared. Also in this case, the flame retardancy was evaluated in the same manner as in the first example. The results are shown in Table 3 together with the fifth and sixth examples as a third comparative example.
[0054]
As is apparent from the results of Table 3, the composite magnetic bodies of the fifth and sixth examples have flame retardancy of V-0 class, and the composite magnetic body of the third comparative example is It turns out that it has the flame retardance of V-1 class. Therefore, it was confirmed that the flame retardancy of the composite magnetic material can be secured by limiting the thickness of the oxide layer on the surface of the soft magnetic powder and the product of the specific surface area of the soft magnetic powder and the thickness of the oxide layer.
[0055]
(Example 7)
Next, as a seventh embodiment, an example in which the soft magnetic powder is surface treated with a coupling agent to improve the kneadability of the admixture will be described. 4 parts by weight of a titanate coupling agent was added to 385 parts by weight of the soft magnetic powder of the Fe—Si—Al alloy used in the fifth example, followed by surface treatment by stirring with a mixer. By kneading 389 parts by weight of this soft magnetic powder, 20 parts by weight of a bromine-based polymer flame retardant, and 20 parts by weight of antimony trioxide as a flame retardant aid in the same manner as in the above examples, composite magnetism was obtained. A body blend was obtained.
[0056]
In the examples described so far, it took 60 minutes to knead to obtain a uniform mixture, but in this example, the kneading time could be shortened to 50 minutes. This is considered to be because the filling property of the soft magnetic powder into the binder is improved by the surface treatment.
[0057]
Further, in this example, an improvement was also observed in the formability of the sheet. In the fifth example, it was necessary to pass the composite magnetic body through the roll four times in order to obtain a 0.5 mm sheet. In this example, the required thickness could be obtained three times.
[0058]
Moreover, the flame retardance was evaluated also about the composite magnetic body obtained by the present Example similarly to the Example demonstrated so far. The results are shown in Table 4.
[0059]
[Table 4]

[0060]
According to Table 4, this example corresponds to the V-0 class with a total of 15 seconds after flame contact after all 10 flames. Compared to the fifth embodiment, the total afterflame time is shortened by 7 seconds, and the difference in the burning time of the test pieces is also reduced.
[0061]
(Example 8)
As an eighth embodiment, an example will be described in which a surface treatment is performed on a Fe—Si—Al alloy powder with a coupling agent, in which the product of the non-surface area and the thickness of the oxide layer is limited. The product of the non-surface area and the thickness of the oxide layer used in the sixth example is 9.0 × 10^-10m³/ G Fe-Si-Al alloy powder was kneaded with a surface treatment, a binder, a flame retardant, and a flame retardant aid in the same manner as in Example 7 to obtain an admixture for a composite magnetic material. . Also in this case, the effect of improving the kneadability and moldability was recognized as in the seventh example.
[0062]
Moreover, the flame retardance was evaluated also about the composite magnetic body obtained by the present Example similarly to the Example demonstrated so far. The results are shown in Table 5.
[0063]
[Table 5]

[0064]
According to Table 5, this example corresponds to the V-0 class with a total of after-flame time after 10 times of flame contact of 25 seconds. Compared to the sixth embodiment, the total after-flame time is shortened by 5 seconds, and the difference in the burning time of the test pieces is also reduced as in the seventh embodiment.
[0065]
Example 9
Next, as a ninth embodiment, an example will be described in which a flat permalloy powder (Fe—Ni alloy powder) having an aspect ratio of 3 or more is subjected to a surface treatment with a coupling agent as a soft magnetic powder. First, the thickness of the oxide layer on the powder surface is 5 × 10^-10m or more 1 × 10^-7Oxidation treatment was performed so as to distribute between m and below. Using this soft magnetic powder, a composite magnetic material was obtained in the same manner as in the seventh and eighth examples, and the flame retardancy was evaluated. As a result, it was confirmed that it had V-0 class flame retardancy. It was.
[0066]
(Example 10)
In addition, as a tenth example, an example in which a soft magnetic powder used in the ninth example is used, and a powder having an oxide layer whose product of specific surface area and thickness is limited is surface-treated with a coupling agent. Will be explained. Here, the product of the specific surface area and the thickness of the powder is 5.0 × 10^-13m³/ G or more 1.5 × 10^-9m³The surface was subjected to an oxidation treatment so as to be in a range of / g or less. The soft magnetic powder was subjected to a surface treatment with a coupling agent to obtain a composite magnetic body in the same manner as in the seventh and eighth examples, and the flame retardancy was evaluated. It has been confirmed that it has sex.
[0067]
(Example 11)
Next, as an eleventh embodiment, an example in which a primer agent is used for the surface treatment of the soft magnetic powder will be described. Here, an epoxy-based polymer was used as a primer agent, and the soft magnetic powder surface was coated. The solubility parameter of this primer agent is 22, which is almost the same as that of the chlorinated polyethylene as the binder. The unit of the numerical value of the solubility parameter used here is MPa.^1/2It is.
[0068]
Soft magnetic powder with an aspect ratio of 3 or more and a specific surface area of 0.6 m²/ G, the thickness of the oxide layer is 1.5 × 10^-9Using the Fe-Si-Al alloy of m, the raw materials were kneaded and sheet-formed in the same manner as in the first example. As a result, in this case as well, as in the seventh and eighth examples, the effect of improving the kneadability and moldability was recognized.
[0069]
Moreover, the flame retardance was evaluated also about the composite magnetic body obtained by the present Example similarly to the Example demonstrated so far. The results are shown in Table 6.
[0070]
[Table 6]

[0071]
According to Table 6, this example corresponds to the V-0 class with a total of 16 seconds after flame contact after all 10 flames contact. Further, compared with the fifth embodiment, the total after-flame time is shortened by 6 seconds, and the difference in the combustion time for each test piece is also reduced.
[0072]
This is because the oxide layer having a certain thickness is provided on the surface of the soft magnetic powder and the surface treatment is applied to the soft magnetic powder, so that the dispersibility is improved, so that the flame retardancy is improved and the variation is also caused. It is understood that it has been reduced.
[0073]
    Example 12
  As a twelfth embodiment, an example will be described in which a powder having an oxide layer with a product of specific surface area and thickness is subjected to a surface treatment with a primer agent. As a soft magnetic powder, the aspect ratio is 3 or more, and the product of the specific surface area and the thickness of the oxide layer is9.0 × 10 ^-Ten m ^Three / GFe-Si-Al alloy powder was prepared. Using this powder, the surface treatment, kneading and sheet molding of the powder were carried out in exactly the same manner as in the eleventh example. As a result, in this case as well, as in the seventh and eighth examples, the effect of improving the kneadability and moldability was recognized.
[0074]
Moreover, the flame retardance was evaluated also about the composite magnetic body obtained by the present Example similarly to the Example demonstrated so far. The results are shown in Table 7.
[0075]
[Table 7]

[0076]
According to this, this example corresponds to the V-0 class with a total of 27 seconds after the flame contact after all 10 flames. Further, compared with the sixth example, the total afterflame time was shortened by 6 seconds, and the difference in the combustion time for each test piece was also reduced, and the same result as in the eleventh example was obtained.
[0077]
(Example 13)
Next, an example using a phosphate ester compound having both functions of a flame retardant and a plasticizer will be described. Here, as the soft magnetic powder, the aspect ratio is 3 or more and the thickness of the oxide layer on the surface is 1.5 × 10.^-9Fe-Si-Al alloy powder which is m was used. First, surface treatment was performed on 385 parts by weight of the powder using 4 parts by weight of a titanate coupling agent.
[0078]
389 parts by weight of this soft magnetic powder and 4 parts by weight of tricresyl phosphate were weighed and mixed with a mixer until uniform. This operation may be performed simultaneously with the surface treatment with the coupling agent. Next, 393 parts by weight of the mixture, 100 parts by weight of chlorinated polyethylene, 20 parts by weight of brominated polymer flame retardant, 20 parts by weight of antimony trioxide, were charged into a pressure kneader and kneaded until uniform. The solubility parameter of tricresyl phosphate used here is 17.2.
[0079]
Using this mixture, sheet molding and evaluation of flame retardancy were performed in the same manner as in the examples described above. Table 8 shows the evaluation results of flame retardancy.
[0080]
[Table 8]

[0081]
According to Table 8, the total afterflame time after all 10 flame contact is 21 seconds, which corresponds to the V-0 class. Also in this case, it can be seen that there is little difference in the burning time of each test piece, and the variation in flame retardancy is reduced.
[0082]
Similar results were obtained using isopropyl triaryl phosphate and cresyl diphenyl phosphate, which are also phosphoric acid ester compounds and have a solubility parameter in the range of 14 to 25.
[0083]
    (Example 14)
  Further, as a fourteenth embodiment, surface treatment, kneading, and sheet forming are performed in exactly the same manner as in the thirteenth embodiment using a soft magnetic powder having an oxide layer with a product of specific surface area and thickness. An example is shown. Here, as the soft magnetic powder, the aspect ratio is 3 or more, and the product of the specific surface area and the thickness of the oxide layer is9.0 × 10 ^-Ten m ^Three / GFe-Si-Al alloy powder was used. Table 9 shows the evaluation results of the flame retardancy of the composite magnetic body according to this example. In this case, as in the thirteenth example, an improvement in flame retardancy and a reduction in variation were observed.
[0084]
[Table 9]

[0085]
(Example 15)
Next, as a fifteenth embodiment, an improvement in flame retardancy was recognized by the addition of a phosphorus-based flame retardant, so an example in which other flame retardants were reduced will be described. First, as a soft magnetic powder, the aspect ratio is 3 or more, and the thickness of the oxide layer on the surface is 1.5 × 10.^-9m-Fe—Si—Al alloy powder was prepared, and surface treatment was performed on 385 parts by weight of the powder using 4 parts by weight of a titanate coupling agent.
[0086]
Next, 389 parts by weight of the surface-treated soft magnetic powder and 4 parts by weight of tricresyl phosphate were mixed with a mixer. This operation may be performed simultaneously with the surface treatment with the coupling agent. Next, 393 parts by weight of the mixture, 14 parts by weight of brominated flame retardant, and 14 parts by weight of antimony trioxide were weighed, put into a pressure kneader, and kneaded until uniform. The brominated flame retardant and antimony trioxide are reduced from 20 parts by weight to 14 parts by weight, respectively, as compared with the examples described so far.
[0087]
About the obtained composite magnetic body, the flame retardance was evaluated similarly to the Example demonstrated so far. Table 10 shows the results.
[0088]
[Table 10]

[0089]
In this example, although the brominated flame retardant and antimony trioxide were each reduced by 30%, the total afterflame time of all 10 flame contact was 27 seconds, and the flame retardancy of V-0 class We were able to secure. This is understood to be due to the synergistic effect of limiting the thickness of the oxide film on the surface, performing the surface treatment with the coupling agent, and further dispersing the phosphorus-based flame retardant.
[0090]
    (Example 16)
  Further, as a sixteenth embodiment, surface treatment, kneading, and sheet forming are performed in exactly the same manner as in the fifteenth embodiment using a soft magnetic powder having an oxide layer with a product of specific surface area and thickness. An example is shown. Here, as the soft magnetic powder, the aspect ratio is 3 or more, and the product of the specific surface area and the thickness of the oxide layer is9.0 × 10 ^-Ten m ^Three / GFe-Si-Al alloy powder was used. Table 11 shows the evaluation results of the flame retardancy of the composite magnetic material according to this example.
[0091]
[Table 11]

[0092]
As is apparent from Table 11, also in this example, the addition of the phosphorus-based flame retardant reduced the brominated flame retardant and antimony trioxide by 30%, respectively. The total afterflame time was 36 seconds, and the flame retardancy of V-0 class could be secured. From this result, it was confirmed that the addition of the phosphorus-based flame retardant showed a certain effect regardless of the surface treatment conditions of the soft magnetic powder.
[0093]
【The invention's effect】
  As explained in detail above, according to the present invention, the thickness of the oxide layer of the soft magnetic powder having an oxide film on the surface.And the product of the specific surface area of the soft magnetic powder and the thickness of the oxide layerBy limiting to a certain range, a composite magnetic body and an electromagnetic interference suppressor excellent in flame retardancy can be obtained. Further, according to the present invention, the thickness of the nitride layer of the soft magnetic powder having a nitride film on the surfaceAnd the product of the specific surface area of the soft magnetic powder and the thickness of the nitride layer,By limiting to a certain range, a composite magnetic body and an electromagnetic interference suppressor excellent in flame retardancy can be obtained.
[0094]
Further, according to the present invention, a surface treatment agent having a solubility parameter substantially the same as that of a binder, surface treatment is performed on the powder surface, or a phosphorus flame retardant having a solubility parameter substantially the same as that of a binder is added. Thus, by improving the dispersibility of each component constituting the composite magnetic body, it is possible to contribute to the improvement of the kneading property and the moldability, and the improvement of the flame retardancy and the variation thereof.
[0095]
It should be noted that the composite magnetic body in the embodiments described so far functions as an electromagnetic interference suppressor that suppresses electromagnetic interference caused by interference of unnecessary radio waves when used in and around electrical equipment. is there.
[Brief description of the drawings]
FIG. 1 is a schematic view of a composite magnetic material according to the present invention.
[Explanation of symbols]
10 Composite magnetic material
11 Soft magnetic powder
12 Binder
13 Flame retardant
14 Flame retardant aid

Claims (8)

A soft magnetic powder having an oxide film on a surface, binding agents, flame retardants, an electromagnetic interference suppressing body using the composite magnetic body made of a flame retardant aid, a thickness of the oxide layer of the soft magnetic powder is 5 × 10 ⁻¹⁰ m to 1 × 10 ⁻⁷ m, and the product of the specific surface area of the soft magnetic powder and the thickness of the oxide layer of the soft magnetic powder, that is, the volume of the oxide layer per unit weight Is in the range of 1.2 × 10 ⁻¹⁰ m ³ / g or more and 3 × 10 ⁻⁷ m ³ / g or less. And the soft magnetic powder having a nitride film on a surface, binding agents, flame retardants, an electromagnetic interference suppressing body using the composite magnetic body made of a flame retardant aid, the thickness of the nitride layer of the soft magnetic powder is 5 × 10 ⁻¹⁰ m to 1 × 10 ⁻⁷ m, the product of the specific surface area of the soft magnetic powder and the thickness of the nitride layer of the soft magnetic powder, that is, the volume of the nitride layer per unit weight Is in the range of 1.0 × 10 ⁻¹⁰ m ³ / g to 3 × 10 ⁻⁷ m ³ / g.   3. The electromagnetic interference suppressor according to claim 1, wherein the soft magnetic powder has a flat shape and an aspect ratio of 3 or more.   4. The electromagnetic interference suppressor according to claim 1, wherein the soft magnetic powder is surface-treated with at least one coupling agent selected from a titanate-based, silane-based, and aluminum-based coupling agent. The electromagnetic interference suppression body characterized by being given.   5. The electromagnetic interference suppressor according to claim 1, wherein the soft magnetic powder is subjected to a surface treatment with a primer having a solubility parameter whose difference from the solubility parameter of the binder is 10 or less. An electromagnetic interference suppressor characterized by being made.   6. The electromagnetic interference suppressor according to claim 1, wherein a phosphorus-based flame retardant having a solubility parameter in the range of 14 to 25 is dispersed in the binder. Suppressor.   7. The electromagnetic interference suppressor according to claim 1, wherein the soft magnetic powder is made of an alloy powder containing at least Fe and Si. 8.   7. The electromagnetic interference suppressor according to claim 1, wherein the soft magnetic powder is made of an alloy powder containing at least Ni and Fe. 8.

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