JP2008016458A - Electromagnetic wave absorbing sheet material - Google Patents
Electromagnetic wave absorbing sheet material Download PDFInfo
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- JP2008016458A JP2008016458A JP2004238169A JP2004238169A JP2008016458A JP 2008016458 A JP2008016458 A JP 2008016458A JP 2004238169 A JP2004238169 A JP 2004238169A JP 2004238169 A JP2004238169 A JP 2004238169A JP 2008016458 A JP2008016458 A JP 2008016458A
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0073—Shielding materials
- H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
- H05K9/0083—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising electro-conductive non-fibrous particles embedded in an electrically insulating supporting structure, e.g. powder, flakes, whiskers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
- H01F1/28—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder dispersed or suspended in a bonding agent
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/34—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials non-metallic substances, e.g. ferrites
- H01F1/342—Oxides
- H01F1/344—Ferrites, e.g. having a cubic spinel structure (X2+O)(Y23+O3), e.g. magnetite Fe3O4
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Abstract
Description
本発明はシート材料に関し、更に詳しくは不要な電磁波の反射・散乱を抑制する特性、すなわち電波吸収特性を有する電磁波吸収シートおよびその製造法に関する。 The present invention relates to a sheet material, and more particularly, to an electromagnetic wave absorbing sheet having properties for suppressing reflection / scattering of unnecessary electromagnetic waves, that is, an electromagnetic wave absorbing property, and a method for producing the same.
携帯電話、ＰＨＳなどの準マイクロ波〜マイクロ波帯域を使用する移動体通信機器類その他電磁波を使用する機器類にあっては、磁化物体その他の磁界発生源が他の物体や電気回路などに悪影響を及ぼさないようにするために、不要な電磁波の反射・散乱を抑制する特性が要求されている。また近年盛んに用いられている非接触型ＩＣカードにおいても、周辺電磁波による誤作動を抑制する必要がある。そのため電磁波吸収性を有する材料が必要とされている。 In mobile communication devices that use quasi-microwave to microwave bands such as mobile phones and PHS, and other devices that use electromagnetic waves, magnetized objects and other magnetic field sources adversely affect other objects and electrical circuits. In order to prevent the interference, it is required to have the characteristic of suppressing the reflection / scattering of unnecessary electromagnetic waves. In addition, even non-contact type IC cards that are actively used in recent years, it is necessary to suppress malfunction due to peripheral electromagnetic waves. Therefore, a material having electromagnetic wave absorptivity is required.
そのような電磁波吸収性を有する材料としては、高磁化率の金属板、磁性体粉末を有機バインダー中に分散させた塗料、ポリマー中に磁性体粉末を添加した組成物（例えば、特許文献１等参照）等が知られている。しかし、高透磁率の金属板は、電波を吸収する一方で電磁波を反射するため、電磁波が増幅されてしまうことがある。 Examples of such an electromagnetic wave absorbing material include a metal plate having a high magnetic susceptibility, a paint in which a magnetic powder is dispersed in an organic binder, and a composition in which the magnetic powder is added to a polymer (for example, Patent Document 1) For example). However, since a high magnetic permeability metal plate absorbs radio waves while reflecting electromagnetic waves, the electromagnetic waves may be amplified.
また、磁性体を有機バインダーに分散させた塗料は、別途成型したフィルムや成型品に塗布する必要があり、そのもの自体で形状を保持することができないといった問題点が存在する。 In addition, a paint in which a magnetic material is dispersed in an organic binder needs to be applied to a separately formed film or molded product, and there is a problem that the shape itself cannot be maintained.
さらに、ポリマー中に磁性体粉末を添加する方法は成型に自由度があるが、電波吸収能が十分発揮される程度に磁性体粉末の添加量を増やすと、成型が難しくなったり、機械的強度が低下して実用に耐えなくなったりするといった問題点が存在する。
本発明の目的は、上記従来技術が有していた問題を解決し、より薄く、高性能の電磁波吸収シートを提供することにある。 An object of the present invention is to solve the above-described problems of the prior art and to provide a thinner and higher performance electromagnetic wave absorbing sheet.
本発明者らは鋭意検討の結果、磁性体粉末を高濃度に含有するシートが高い電磁波吸収能と機械強度を併せ持つことを見出し、本発明に至った。
すなわち本発明は以下のものである。
１．磁性体粉末と熱可塑性樹脂とからなり厚みが５００μｍ以下である自立性シート材料であって、該磁性体粉末と該熱可塑性樹脂の合計量に基づいた重量百分率で該磁性体粉末を４０〜９８％、該熱可塑性樹脂を２〜６０％含有し、且つ、空孔率が０〜４５％であることを特徴とする電磁波吸収シート材料。
２．磁性体粉末が軟磁性粉末であるシート材料。
３．磁性体粉末がフェライト粉末であるシート材料。
４．熱可塑性樹脂が実質的にポリオレフィン樹脂であるシート材料。
５．熱可塑性樹脂が実質的に少なくとも５ｄｌ/ｇの固有粘度を有するポリエチレンからなるシート材料。
６．磁性体粉末の平均粒径が０．００５〜１００μｍであるシート材料。
７．磁性体粉末が長軸と短軸とを有する扁平な形状であって、該磁性体粉末の長軸方向とシート材料の面方向とが平行に配向するように該磁性体粉末がシート材料中に存在するシート材料。
８．磁性体粉末と熱可塑性樹脂とからなり厚みが５００μｍ以下である自立性シート材料であって、該磁性体粉末と該熱可塑性樹脂の合計量に基づいた重量百分率で該磁性体粉末を４０〜９８％、該熱可塑性樹脂を２〜６０％含有し、且つ、空孔率が０〜４５％である電磁波吸収シート材料を製造する方法であって、実質的に溶剤、磁性体粉末及び熱可塑性樹脂からなる熱可逆的ゲル化溶液を用いてゲル化製膜し、ついで延伸することによりシート状に形成することを特徴とする、磁性体粉末を含有する電磁波吸収シート材料の製造方法。
９．請求項１記載の磁性体粉末を含有するシート材料を、カレンダー処理あるいは熱プレス処理することによって得られる、空孔率０．１〜３９％の磁性体粉末を含有する電磁波吸収シート材料。
As a result of intensive studies, the present inventors have found that a sheet containing a magnetic substance powder at a high concentration has both high electromagnetic wave absorption ability and mechanical strength, leading to the present invention.
That is, the present invention is as follows.
1. A self-supporting sheet material comprising a magnetic powder and a thermoplastic resin and having a thickness of 500 μm or less, wherein the magnetic powder is 40 to 98 at a weight percentage based on the total amount of the magnetic powder and the thermoplastic resin. %, 2 to 60% of the thermoplastic resin, and the porosity is 0 to 45%.
2. A sheet material in which the magnetic powder is a soft magnetic powder.
3. A sheet material in which the magnetic powder is a ferrite powder.
4). A sheet material in which the thermoplastic resin is substantially a polyolefin resin.
5. A sheet material wherein the thermoplastic resin consists essentially of polyethylene having an intrinsic viscosity of at least 5 dl / g.
6). A sheet material having an average particle diameter of magnetic powder of 0.005 to 100 μm.
7). The magnetic powder has a flat shape having a major axis and a minor axis, and the magnetic powder is in the sheet material so that the major axis direction of the magnetic powder and the surface direction of the sheet material are oriented in parallel. Existing sheet material.
8). A self-supporting sheet material comprising a magnetic powder and a thermoplastic resin and having a thickness of 500 μm or less, wherein the magnetic powder is 40 to 98 at a weight percentage based on the total amount of the magnetic powder and the thermoplastic resin. %, A method for producing an electromagnetic wave absorbing sheet material containing 2 to 60% of the thermoplastic resin and having a porosity of 0 to 45%, which is substantially a solvent, a magnetic powder and a thermoplastic resin A method for producing an electromagnetic wave absorbing sheet material containing magnetic powder, characterized in that a gelled film is formed using a thermoreversible gelling solution comprising, and then stretched to form a sheet.
9. An electromagnetic wave absorbing sheet material containing magnetic powder having a porosity of 0.1 to 39%, obtained by calendering or hot pressing the sheet material containing the magnetic powder according to
本発明によれば、磁性体粉末４０〜９８％と熱可塑性樹脂２〜６０％を含有し、且つ、空孔率が０〜４５％であるする自立性シート材料を用いることにより、より薄く、高性能の電磁波吸収シート材料を提供することができる。 According to the present invention, by using a self-supporting sheet material containing 40 to 98% magnetic powder and 2 to 60% thermoplastic resin and having a porosity of 0 to 45%, it is thinner, A high-performance electromagnetic wave absorbing sheet material can be provided.
以下、本発明を詳細に説明する。
本発明の電磁波吸収シート材料（以下、単にシート材料と略記することがある。）は、電磁波吸収能を有するシート状の材料であり磁性体粉末を重量百分率で４０〜９８％、熱可塑性樹脂を２〜６０％含有する自立性シートである。
Hereinafter, the present invention will be described in detail.
The electromagnetic wave absorbing sheet material of the present invention (hereinafter sometimes abbreviated as “sheet material”) is a sheet-like material having an electromagnetic wave absorbing ability. The magnetic powder is 40 to 98% by weight, and a thermoplastic resin is used. It is a self-supporting sheet containing 2 to 60%.
本発明のシート材料は実質的に磁性体粉末と熱可塑性樹脂とからなり可塑剤等の液体成分を含まない。更には磁性体粉末を最大で９８％含有することが可能であるため、磁性体を高密度で保持することができ、薄膜化にきわめて有利である。またシート材料自体の力学強度が十分であり、小型化、薄層化に有利である。 The sheet material of the present invention substantially comprises a magnetic powder and a thermoplastic resin and does not contain a liquid component such as a plasticizer. Furthermore, since it is possible to contain up to 98% of the magnetic substance powder, the magnetic substance can be held at a high density, which is extremely advantageous for thinning. Further, the mechanical strength of the sheet material itself is sufficient, which is advantageous for downsizing and thinning.
磁性体粉末の含有率は、該磁性体粉末と該熱可塑性樹脂の合計量に基づいた重量百分率で４０〜９８％、好ましくは７５〜９８％、より好ましくは８５〜９８％である。９８％より磁性体成分の含有率が多い場合は、機械的強度に問題が生じる場合がある。逆に磁性体成分が少ない場合は、電磁波吸収能が不十分になる可能性がある。 The content of the magnetic powder is 40 to 98%, preferably 75 to 98%, more preferably 85 to 98% in terms of a weight percentage based on the total amount of the magnetic powder and the thermoplastic resin. When the content of the magnetic component is higher than 98%, a problem may occur in mechanical strength. On the contrary, when there are few magnetic substance components, electromagnetic wave absorption ability may become inadequate.
また、本発明のシート材料は、その空孔率が０〜４５％であることが必要である。該空孔率が４５％を越えると、電磁波吸収能が不十分になる可能性がある。 Further, the sheet material of the present invention needs to have a porosity of 0 to 45%. If the porosity exceeds 45%, the electromagnetic wave absorbing ability may be insufficient.
本発明のシート材料は磁性体成分とその結着剤としての熱可塑性樹脂以外には基本的には溶剤、可塑剤成分を含有しない。従って使用環境下での有機成分のブリードアウト等の問題が少ない。 The sheet material of the present invention basically contains no solvent or plasticizer component other than the magnetic component and the thermoplastic resin as the binder. Accordingly, there are few problems such as bleed-out of organic components under the use environment.
本発明のシート材料は自立性のシートである事を特徴としている。従ってベースフィルムのような不要な廃棄物を用いる必要もなく、引張強度に優れハンドリングの面でもきわめて優れている。 The sheet material of the present invention is characterized by being a self-supporting sheet. Therefore, there is no need to use unnecessary waste such as a base film, and the tensile strength is excellent and the handling is extremely excellent.
本発明のシート材料の熱可塑性樹脂成分は実質的にポリオレフィン樹脂が好ましい。ここで実質的というのはポリオレフィン樹脂中に安定剤、可塑剤等、少量の改質成分を含んでも問題ないということである。ポリオレフィン樹脂としてはポリエチレン樹脂、ポリプロピレン樹脂等が例示できる。 The thermoplastic resin component of the sheet material of the present invention is preferably substantially a polyolefin resin. Here, “substantially” means that a small amount of modifying components such as stabilizers and plasticizers may be contained in the polyolefin resin. Examples of the polyolefin resin include a polyethylene resin and a polypropylene resin.
更には該熱可塑性樹脂は実質的に少なくとも５ｄｌ／ｇの固有粘度を有するポリエチレン樹脂である。固有粘度が５ｄｌ／ｇ未満の場合、シートとしての強度が不十分となり自立性等が失われる可能性がある。このような条件を満たすポリエチレン樹脂としては超高分子量ポリエチレン（ＵＨＭＷＰＥ）や高密度ポリエチレン（ＨＤＰＥ）が例示できる。またこれらのブレンド物、あるいはこれらの高分子ポリマーと低分子ポリマーのブレンド体であっても、ブレンド体の固有粘度が５ｄｌ／ｇ以上であれば差し支えない。 Further, the thermoplastic resin is a polyethylene resin having an intrinsic viscosity of substantially at least 5 dl / g. When the intrinsic viscosity is less than 5 dl / g, the strength as a sheet becomes insufficient, and the self-supporting property may be lost. Examples of the polyethylene resin that satisfies such conditions include ultra high molecular weight polyethylene (UHMWPE) and high density polyethylene (HDPE). Moreover, even if it is a blend of these, or a blend of these high molecular polymer and low molecular polymer, the intrinsic viscosity of the blend may be 5 dl / g or more.
本発明のシート材料の厚みとしては、５００μｍ以下である。本発明のようなシートの場合、測定の方法により大きく厚みが異なる。本願発明での厚みは光学顕微鏡、レーザー顕微鏡あるいはＳＥＭ等の観察により、割断面を非接触で測定した厚みである。５００μｍより厚い場合は、近年の薄膜化の流れと相反することになる。 The thickness of the sheet material of the present invention is 500 μm or less. In the case of a sheet like the present invention, the thickness varies greatly depending on the measurement method. The thickness in the present invention is a thickness obtained by measuring the cut surface in a non-contact manner through observation with an optical microscope, a laser microscope, or an SEM. When it is thicker than 500 μm, it is contrary to the recent trend of thinning.
本発明の電磁波吸収シート材料に用いる磁性体粉末としては、軟磁性粉末、フェライト粉末等が例示できる。軟磁性粉末としては、カルボニル鉄、パーマロイ、センダスト、鉄−ケイ素合金、鉄−アルミ−クロム合金、電磁ステンレス鋼等を例示することができる。該磁性体粉末の平均粒径は通常０．００５〜１００μｍが好ましい。０．００５μｍより小さい場合、電磁波吸収能が不十分となることがある。１００μｍより大きい場合、シート材料中で、上手く分散できない可能性がある。 Examples of the magnetic powder used for the electromagnetic wave absorbing sheet material of the present invention include soft magnetic powder and ferrite powder. Examples of the soft magnetic powder include carbonyl iron, permalloy, sendust, iron-silicon alloy, iron-aluminum-chromium alloy, and electromagnetic stainless steel. The average particle size of the magnetic powder is usually preferably 0.005 to 100 μm. When it is smaller than 0.005 μm, the electromagnetic wave absorbing ability may be insufficient. If it is larger than 100 μm, there is a possibility that it cannot be dispersed well in the sheet material.
本発明の電磁波吸収シート材料は、磁性体粉末が長軸と短軸とを有する扁平な形状であって、該磁性体粉末の長軸方向と多孔質シート材料の面方向とが平行に配向するように該磁性体粉末が多孔質シート材料中に存在する。本発明のシート材料は平面方向に高倍率に延伸して製造するため、扁平な粉末を用いると面方向に平行に並ぶ。それにより、電磁波吸収能をより高めることが可能となる。 The electromagnetic wave absorbing sheet material of the present invention has a flat shape in which the magnetic powder has a major axis and a minor axis, and the major axis direction of the magnetic substance powder and the surface direction of the porous sheet material are oriented in parallel. Thus, the magnetic substance powder is present in the porous sheet material. Since the sheet material of the present invention is produced by stretching at a high magnification in the plane direction, when a flat powder is used, the sheet material is aligned in parallel to the plane direction. Thereby, the electromagnetic wave absorbing ability can be further increased.
本発明の電磁波吸収シート材料の製造方法としては、特に制限はないが、実質的にゲル化製膜及び得られたゲル化シートを延伸することにより製造することができる。例えば、磁性体粉末をミリング装置等を用いて適当なゲル化溶媒中に分散させた後、結着剤としての熱可塑性樹脂と適当な上記ゲル化溶媒の残りを加えて、該熱可塑性樹脂と該溶媒を加熱溶解させることによりゾル化させる。 Although there is no restriction | limiting in particular as a manufacturing method of the electromagnetic wave absorption sheet material of this invention, It can manufacture by extending | stretching substantially gelled film forming and the obtained gelled sheet. For example, after dispersing the magnetic powder in an appropriate gelling solvent using a milling device or the like, the thermoplastic resin as a binder and the remainder of the appropriate gelling solvent are added, and the thermoplastic resin and The solvent is dissolved in by heating to make a sol.
このようにして得られたゾル化組成物をゲル化温度以上の温度にてテープ状に付形し、該シート状物をゲル化点以下に急冷することによりゲル化シートを作成する。このゲル化シートを、熱可塑性樹脂のガラス転移点以上の温度で1軸あるいは2軸に延伸し、その後熱固定することにより製造することができる。かかる溶媒としては、例えばポリエチレンを熱可塑性樹脂として用いる場合、通常デカリン、ヘキサン、パラフィン、キシレン等が挙げられる。これらは２種類以上組み合わせて用いてもよい。 The solated composition thus obtained is shaped into a tape at a temperature equal to or higher than the gelation temperature, and the sheet is rapidly cooled below the gel point to prepare a gelled sheet. This gelled sheet can be produced by stretching uniaxially or biaxially at a temperature equal to or higher than the glass transition point of the thermoplastic resin, and then heat fixing. Examples of such a solvent include usually decalin, hexane, paraffin, xylene and the like when polyethylene is used as the thermoplastic resin. Two or more of these may be used in combination.
本発明の電磁波吸収シート材料はあらかじめ、カレンダー処理あるいは熱プレスしても良い。その際の空孔率は空孔率０．１〜３９％である。予め空孔率を低下させるかどうかは電磁波吸収体を用いる方法によるが、基本的には空孔率が小さい方が電磁波吸収能が高くなる傾向にある。 The electromagnetic wave absorbing sheet material of the present invention may be calendered or hot pressed in advance. The porosity in that case is 0.1 to 39%. Whether or not the porosity is lowered in advance depends on a method using an electromagnetic wave absorber, but basically, the smaller the porosity is, the higher the electromagnetic wave absorbing ability tends to be.
本発明の電磁波吸収シート材料は、空孔率を下げた状態から脱媒、焼成することにより、有機物を含まない電磁波吸収体を形成することも可能である。 The electromagnetic wave absorbing sheet material of the present invention can also form an electromagnetic wave absorber that does not contain an organic substance by removing and baking from a state where the porosity is lowered.
次に、本発明を以下の実施例により更に具体的に説明するが、本発明は以下の実施例に制限されるものではない。なお、実施例中の値は以下の方法で測定した。
（１）シート材料の厚さ：
凍結割断法で断面を出した後、走査型電子顕微鏡またはレーザー顕微鏡により非接触で測定した。
（２）シート材料の密度：
既知容量のシート材料片の重量を測定することにより決定した。
（３）空孔率：
測定したシート材料の密度ρと空孔のないシート材料の理論密度ρ０から以下の式により求めた。
空孔率 ＝ （ρ０−ρ） ／ ρ０ × １００ （％）
（４）電界シールド効果：
シールド効果の測定は、社団法人関西電子工業振興センターに測定を依頼し、測定法「ＫＥＣ法」により行なわれた。
Next, the present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the following examples. In addition, the value in an Example was measured with the following method.
(1) Sheet material thickness:
After the cross section was taken out by the freezing cleaving method, it was measured in a non-contact manner with a scanning electron microscope or a laser microscope.
(2) Density of sheet material:
It was determined by measuring the weight of a known volume of sheet material.
(3) Porosity:
From the measured density ρ of the sheet material and the theoretical density ρ0 of the sheet material having no pores, the following formula was used.
Porosity = (ρ0−ρ) / ρ0 × 100 (%)
(4) Electric field shielding effect:
The shield effect was measured by the Kansai Electronics Industry Promotion Center and measured by the measurement method “KEC method”.
［実施例１］
デカリン１７重量部に、パラフィン油（Ｓｈｅｌｌ社製 Ｏｎｄｉｎａ Ｏｉｌ ６８）１１重量部および１５ｄｌ／ｇの極限粘度（デカリン中１３５℃で測定）を有する超高分子量ポリエチレン（三井化学株式会社製「ハイゼックスミリオン」２４０Ｍ）３重量部を加え、Ｄ５０＝６０μｍの扁平状パーマロイ６９重量部を分散させた。
[Example 1]
Ultrahigh molecular weight polyethylene ("Hi-Zex Million" manufactured by Mitsui Chemicals, Inc.) having 11 parts by weight of paraffin oil (Ondina Oil 68 manufactured by Shell) and an intrinsic viscosity of 15 dl / g (measured at 135 ° C in decalin) in 17 parts by weight of decalin 240M) 3 parts by weight was added and 69 parts by weight of flat permalloy with D50 = 60 μm was dispersed.
該分散体を２軸混練押し出し機を用いて１８０℃で溶解させてゾル化し、該ゾル化物をフラットフィルム押し出しダイを介して１５０℃で押し出した。ついで、該押し出し品を水浴を通過させて冷却し、ゲル化させた。この様にして成型されたシートを８０℃で１時間乾燥させることにより、デカリンを除去した。このシート厚みは１ｍｍであった。 The dispersion was melted at 180 ° C. using a biaxial kneading extruder to form a sol, and the sol was extruded at 150 ° C. through a flat film extrusion die. The extrudate was then allowed to cool by passing through a water bath and gelled. Decalin was removed by drying the sheet thus molded at 80 ° C. for 1 hour. The sheet thickness was 1 mm.
このパラフィン油がシート中に残留したパラフィン油含有シートを、延伸中の温度を１１５℃でＭＤ方向に３倍、１２０℃でＴＤ方向に７倍に２軸延伸した。その後パラフィン油をヘキサンを用いてシートから抽出し、６０℃で１０分間乾燥し、１４０℃で３分間熱固定し、シートを得た。得られたシート厚みは１２０μｍ、空孔率は７６％であった。このシートを１０枚重ねて１３５℃でプレスし、厚み３００μｍ、空孔率３０％のシートを得た。得られたシートのシールド効果測定の結果を図１に、引っ張り強度試験結果を表１にそれぞれ示す。 The paraffin oil-containing sheet in which the paraffin oil remained in the sheet was biaxially stretched 3 times in the MD direction at 115 ° C. and 7 times in the TD direction at 120 ° C. Thereafter, paraffin oil was extracted from the sheet using hexane, dried at 60 ° C. for 10 minutes, and heat-fixed at 140 ° C. for 3 minutes to obtain a sheet. The obtained sheet thickness was 120 μm and the porosity was 76%. Ten sheets were stacked and pressed at 135 ° C. to obtain a sheet having a thickness of 300 μm and a porosity of 30%. The result of the shielding effect measurement of the obtained sheet is shown in FIG. 1, and the result of the tensile strength test is shown in Table 1.
Claims (9)
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004238169A JP2008016458A (en) | 2004-08-18 | 2004-08-18 | Electromagnetic wave absorbing sheet material |
| PCT/JP2005/015299 WO2006019172A1 (en) | 2004-08-18 | 2005-08-17 | Electromagnetic wave absorbing sheet |
| TW094128232A TW200612817A (en) | 2004-08-18 | 2005-08-18 | Electromagnetic wave absorbing sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004238169A JP2008016458A (en) | 2004-08-18 | 2004-08-18 | Electromagnetic wave absorbing sheet material |
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| JP2008016458A true JP2008016458A (en) | 2008-01-24 |
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|---|---|---|---|
| JP2004238169A Pending JP2008016458A (en) | 2004-08-18 | 2004-08-18 | Electromagnetic wave absorbing sheet material |
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| Country | Link |
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| JP (1) | JP2008016458A (en) |
| TW (1) | TW200612817A (en) |
| WO (1) | WO2006019172A1 (en) |
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| JP2011003583A (en) * | 2009-06-16 | 2011-01-06 | Asahi Kasei E-Materials Corp | Composite sheet |
| EP2521143A1 (en) * | 2011-05-06 | 2012-11-07 | Voigt, Volker | Magnetically active material |
| JP5474251B1 (en) * | 2013-02-04 | 2014-04-16 | Ｎｅｃトーキン株式会社 | Magnetic core and inductor |
| JP2018083079A (en) * | 2016-11-22 | 2018-05-31 | 佛山市▲順▼▲徳▼区美的▲電▼▲熱▼▲電▼器制造有限公司Ｆｏｓｈａｎ Ｓｈｕｎｄｅ Ｍｉｄｅａ Ｅｌｅｃｔｒｉｃａｌ Ｈｅａｔｉｎｇ Ａｐｐｌｉａｎｃｅｓ Ｍａｎｕｆａｃｔｕｒｉｎｇ Ｃｏ．，Ｌｉｍｉｔｅｄ | Compact-structure magnetically conductive coating layer, method of manufacturing compact-structure magnetically conductive coating layer, pot body, and cooking appliance |
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| EP1819211A4 (en) * | 2004-12-03 | 2011-02-23 | Nitta Corp | Electromagnetic interference inhibitor, antenna device and electronic communication apparatus |
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| JP4177523B2 (en) * | 1999-07-16 | 2008-11-05 | 京セラ株式会社 | Radio wave absorber |
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| JP2001126910A (en) * | 1999-10-25 | 2001-05-11 | Tokin Corp | Composite magnetic material, composite magnetic material sheet and manufacturing method of them |
| JP4446593B2 (en) * | 2000-12-26 | 2010-04-07 | 京セラ株式会社 | Electromagnetic wave absorber |
| JP2003229694A (en) * | 2002-02-05 | 2003-08-15 | Sony Corp | Electromagnetic wave absorbent and its manufacturing method |
| JP2003324299A (en) * | 2002-05-01 | 2003-11-14 | Daido Steel Co Ltd | Halogen-free flame retardant electromagnetic wave suppressing sheet and its manufacturing method |
| JP2004059832A (en) * | 2002-07-31 | 2004-02-26 | Hitachi Cable Ltd | Electromagnetic wave absorbing material composition and electromagnetic wave absorber |
-
2004
- 2004-08-18 JP JP2004238169A patent/JP2008016458A/en active Pending
-
2005
- 2005-08-17 WO PCT/JP2005/015299 patent/WO2006019172A1/en not_active Application Discontinuation
- 2005-08-18 TW TW094128232A patent/TW200612817A/en unknown
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2011003583A (en) * | 2009-06-16 | 2011-01-06 | Asahi Kasei E-Materials Corp | Composite sheet |
| EP2521143A1 (en) * | 2011-05-06 | 2012-11-07 | Voigt, Volker | Magnetically active material |
| JP5474251B1 (en) * | 2013-02-04 | 2014-04-16 | Ｎｅｃトーキン株式会社 | Magnetic core and inductor |
| JP2018083079A (en) * | 2016-11-22 | 2018-05-31 | 佛山市▲順▼▲徳▼区美的▲電▼▲熱▼▲電▼器制造有限公司Ｆｏｓｈａｎ Ｓｈｕｎｄｅ Ｍｉｄｅａ Ｅｌｅｃｔｒｉｃａｌ Ｈｅａｔｉｎｇ Ａｐｐｌｉａｎｃｅｓ Ｍａｎｕｆａｃｔｕｒｉｎｇ Ｃｏ．，Ｌｉｍｉｔｅｄ | Compact-structure magnetically conductive coating layer, method of manufacturing compact-structure magnetically conductive coating layer, pot body, and cooking appliance |
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Also Published As
| Publication number | Publication date |
|---|---|
| TW200612817A (en) | 2006-04-16 |
| WO2006019172A1 (en) | 2006-02-23 |
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