JPH01261897A - Magnetic shielding sheet - Google Patents
Magnetic shielding sheetInfo
- Publication number
- JPH01261897A JPH01261897A JP63088967A JP8896788A JPH01261897A JP H01261897 A JPH01261897 A JP H01261897A JP 63088967 A JP63088967 A JP 63088967A JP 8896788 A JP8896788 A JP 8896788A JP H01261897 A JPH01261897 A JP H01261897A
- Authority
- JP
- Japan
- Prior art keywords
- iron powder
- magnetic
- carbonyl iron
- shielding
- sheet
- 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.)
- Granted
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 50
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 30
- 239000011230 binding agent Substances 0.000 claims abstract description 10
- 239000000203 mixture Substances 0.000 claims abstract description 8
- 239000011347 resin Substances 0.000 claims abstract description 7
- 229920005989 resin Polymers 0.000 claims abstract description 7
- 239000002245 particle Substances 0.000 claims description 10
- 239000003973 paint Substances 0.000 claims description 5
- 239000002904 solvent Substances 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 16
- 239000000463 material Substances 0.000 abstract description 16
- 230000035699 permeability Effects 0.000 abstract description 16
- 229910052742 iron Inorganic materials 0.000 abstract description 4
- 230000007423 decrease Effects 0.000 abstract description 3
- 239000000843 powder Substances 0.000 description 9
- 239000000696 magnetic material Substances 0.000 description 4
- 239000000956 alloy Substances 0.000 description 3
- 230000005415 magnetization Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000003302 ferromagnetic material Substances 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- 239000006247 magnetic powder Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 229920002799 BoPET Polymers 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 229940087654 iron carbonyl Drugs 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000005476 size effect Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、各種磁気記録媒体の記録保護を目的とした強
磁界シールド用磁気シールドシートに関するものである
。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic shield sheet for shielding strong magnetic fields for the purpose of protecting recording of various magnetic recording media.
（従来の技術）
従来各種磁気記録媒体の記録保護の目的で、さまざまな
磁気シールド材が作られているが、多くのものが、Ｆｅ
５Ｎｉ等の強磁性体及びその合金の薄板を用いたもので
あって、可撓性に乏しく、また塑性変形する等の取扱い
上の欠点を有している。(Prior Art) Various magnetic shielding materials have been produced for the purpose of protecting the recording of various magnetic recording media, but many of them are made of Fe.
It uses a thin plate of a ferromagnetic material such as 5Ni or its alloy, and has disadvantages in handling such as poor flexibility and plastic deformation.
−力強磁性体金属あるいはその合金の粉末を塗料化して
、各種シート状基体上に塗布して用いる方法があるが、
この場合塗料化するために粉末を微粒化すると塗布した
シートとして出来上ったものの透磁率が悪くなり、シー
ルド効果が劣化する。- There is a method of making a powder of ferromagnetic metal or its alloy into a paint and applying it on various sheet-like substrates.
In this case, if the powder is atomized to make it into a paint, the magnetic permeability of the coated sheet will deteriorate, and the shielding effect will deteriorate.
（本発明が解決しようとする問題点）
通常百ガウス以上の直流強磁界のシールドを行う場合、
磁気遮蔽体として、強磁性体とりわけ軟磁性体を用いる
方法が一般的である。しかし、直流の弱磁界シールドの
場合は低保磁力で高透磁率の材料が必要であるが、百ガ
ウス以上の強磁界を何割か減少させることを目的とする
ような場合には必ずしも高透磁率材が最良とは云えない
。すなわち、シールドすべき外部磁界強度において、透
磁率が大きいことが必要である。高透磁率材の場合、１
００ガウス以上の磁界ではほぼ飽和しておリ、従って、
飽和磁化が大きい材料の方が透磁率が太き（なり、磁気
遮蔽効果は大きい。一方有機バインダーと磁性材料粉を
混合して、塗料あるいはインキ化する場合には磁性粉が
沈降あるいは分離しない程度に微粒であることが必要で
ある。この為には通常比重で７〜８程度の金属粉の場合
、粒径で１５μ以下の微粉とする必要がある。しかし、
はとんどの軟磁性材を１５μ以下の微粉とすると透磁率
が低下する。これは、１５μ以下の微粉を効率よく安価
に製造する方法として、粉砕、あるいはアトマイズ等の
方法によるため歪による応力の影響があることと、サイ
ズ効果のためである。このような観点から我々は、１０
０ガウス以上の強磁界シールドには、種々の高透磁率合
金材を粉末化するよりも、透磁率は、種々の高透磁率材
に比して若干劣るが飽和磁化が大きい純鉄に注目し、鉄
粉の特性を改良した方が有利であると考え、種々の方法
で作製された鉄粉を試験した。この結果、鉄カルボニル
（Ｆｅ （Ｃｏ） ｓ）を分解させて作る粒径３〜１０
μのカルボニル鉄粉が、１００ガウス以上の強磁界シー
ルドには、むしろ良好であることを見出した。(Problems to be solved by the present invention) When shielding a direct current strong magnetic field of 100 Gauss or more,
A common method is to use a ferromagnetic material, particularly a soft magnetic material, as the magnetic shield. However, in the case of direct current weak magnetic field shielding, a material with low coercive force and high magnetic permeability is required, but if the purpose is to reduce a strong magnetic field of 100 Gauss or more by some percentage, it is not necessary to use a material with high magnetic permeability. The material is not the best. That is, it is necessary that the magnetic permeability is large at the external magnetic field strength to be shielded. For high permeability materials, 1
It is almost saturated in a magnetic field of 0.00 Gauss or more, therefore,
Materials with higher saturation magnetization have higher magnetic permeability (and therefore have a greater magnetic shielding effect).On the other hand, when mixing an organic binder and magnetic material powder to form a paint or ink, it is necessary to use a material that does not settle or separate. For this reason, in the case of metal powder with a normal specific gravity of about 7 to 8, it is necessary to make it a fine powder with a particle size of 15μ or less.However,
When most soft magnetic materials are made into fine powder of 15μ or less, the magnetic permeability decreases. This is because pulverization, atomization, or other methods are used to efficiently and inexpensively produce fine powder of 15 μm or less, which is affected by stress due to strain, and because of the size effect. From this perspective, we
For strong magnetic field shielding of 0 Gauss or more, rather than powdering various high magnetic permeability alloy materials, we focus on pure iron, which has a large saturation magnetization although its magnetic permeability is slightly inferior to various high magnetic permeability materials. They thought that it would be advantageous to improve the properties of iron powder, and tested iron powder made by various methods. As a result, particles with a diameter of 3 to 10 made by decomposing iron carbonyl (Fe (Co) s)
It has been found that carbonyl iron powder of μ is rather good for shielding strong magnetic fields of 100 Gauss or more.
即ち、本発明は、磁性粉末の層を形成した磁気シールド
シートを提供することを、解決すべき課題とする。That is, an object of the present invention is to provide a magnetic shield sheet in which a layer of magnetic powder is formed.
（課題を解決するための手段とその作用）本発明は、前
述した課題を解決するために、平均粒径で３−１０μｍ
のカルボニル鉄粉を重量比で２０％以上を含む少くとも
有機バインダーとの混合体を祇あるいは樹脂フィルム上
にシート状に配した磁気シールドシートを提供する。(Means for Solving the Problems and Their Effects) In order to solve the above-mentioned problems, the present invention has an average particle size of 3 to 10 μm.
To provide a magnetic shielding sheet in which a mixture of carbonyl iron powder containing at least 20% by weight of carbonyl iron powder and at least an organic binder is arranged in a sheet form on a resin film.
カルボニル鉄粉は、熱分解により製造される為、十分に
焼鈍された純鉄の特性に近く、保磁力も平均粒径３〜１
０μの範囲の粒径であれば、６ｏｅ前後の小さな値であ
り、透磁率も比較的良好である。Since carbonyl iron powder is manufactured by thermal decomposition, it has properties close to that of fully annealed pure iron, and its coercive force has an average particle size of 3 to 1.
If the particle size is in the range of 0 μ, the value is small, around 6 oe, and the magnetic permeability is also relatively good.
表１に各種高ｙｉ磁率材粉末との磁気特性の比較を示す
、この表から判るように、同じ粒径の他の高透磁率材に
比較すると、高磁界のシールド効果において、優位であ
ることが判る。但し、平均粒径で、３μ以下のものは、
保磁力も大きくなり、表面の酸化の影響により飽和磁化
が低下するので、他の材料に比して優位であるとは云え
なくなる。Table 1 shows a comparison of magnetic properties with various high yi magnetic material powders.As can be seen from this table, it is superior in shielding effect in high magnetic fields when compared to other high magnetic permeability materials with the same particle size. I understand. However, if the average particle size is 3μ or less,
Since the coercive force also increases and the saturation magnetization decreases due to the influence of surface oxidation, it cannot be said that it is superior to other materials.
表 １
一方、本鉄粉を塗料化して塗布するか、種々のプラスチ
ック材と混合してシート状に成形することにより磁気シ
ールド層を形成する場合において、磁気シールド層中に
おいては、磁性粉が密に充填されている方がシールド効
果が大きい、この点、本発明になるカルボニル鉄粉は、
粒子が球形に近く高密度の充填が可能であるという特徴
を有している０図にバインダーとカルボニル鉄粉の量比
を変えた場合のシールド効果の様子を示す。これから判
るように重量比で２０％以下では、シールド効果が大き
く低下し、実用上の効果がなくなる。Table 1 On the other hand, when forming a magnetic shielding layer by applying real iron powder as a paint or mixing it with various plastic materials and forming it into a sheet, the magnetic powder is densely packed in the magnetic shielding layer. In this respect, the carbonyl iron powder of the present invention has a greater shielding effect when filled with
Figure 0 shows the shielding effect when the ratio of binder to carbonyl iron powder is varied. As can be seen, if the weight ratio is less than 20%, the shielding effect is greatly reduced and the practical effect is lost.
なお、純鉄は耐食性が問題となるが、本発明のごとく有
機バインダーと混合して用いる場合は、バインダーが鉄
粉表面を覆うため錆の問題は余りない。Note that corrosion resistance is a problem with pure iron, but when used in combination with an organic binder as in the present invention, the binder covers the surface of the iron powder, so there is not much of a problem with rust.
一方、カルボニル鉄粉は、従来圧粉磁芯等に用いられて
いるが、電磁波シールド材として用いる提案もなされて
いる（例えば、特開昭６０−１５４６４、特開昭６ｌ−
９７９９８）。しかし、これらの技術は、交流電磁界の
しゃへいを目的としたものであり、カルボニル鉄粉と他
の導伝性材料を複合し、その複合したもの交流損失を利
用してしゃへいを行うものであるのに対して、直流磁気
シールドは磁束をしゃへい材の中に吸い寄せることによ
り、しゃへいを行うものであるので、材料に要求される
特性は異なる。すなわち、交流磁界シールドにおいては
、低磁界の交流磁界での透磁率と電気抵抗が問題になる
のに対して、直流高磁界では、その磁界における見掛上
の透磁率が問題となる。従って、本発明は、上に述べた
先行技術とは目的が異る他に材料探索の観点も異るもの
であり、上記先行技術に示されているしゃへい材は、非
磁性体を含んでいて、本発明の意図する用途には、かえ
って不利である。On the other hand, carbonyl iron powder has been conventionally used in powder magnetic cores, etc., but it has also been proposed to be used as an electromagnetic shielding material (for example, JP-A-60-15464, JP-A-6L-
97998). However, these technologies are aimed at shielding AC electromagnetic fields, and shield carbonyl iron powder and other conductive materials by combining them and utilizing the AC loss of the composite. On the other hand, DC magnetic shielding achieves shielding by attracting magnetic flux into the shielding material, so the characteristics required of the material are different. That is, in an AC magnetic field shield, the problem is magnetic permeability and electrical resistance in a low AC magnetic field, whereas in a DC high magnetic field, the apparent magnetic permeability in the magnetic field is a problem. Therefore, the present invention differs from the prior art described above not only in purpose but also in terms of material exploration. , which is rather disadvantageous for the intended use of the present invention.
（実施例）
（１） 平均粒径５μのカルボニル鉄粉と有機バイン
ダーとしてのアクリル樹脂とを重量比でｌＯＯ：２０混
合して、溶剤を添加し、ＰＥＴフィルム上にコーティン
グし、約０．２鶴のシールド層を形成した。このシート
のシールド効果を測定した結果、７００Ｇ（磁場源の大
きさ５ｆｌφ）の磁場を約１２％減少させた。なお、こ
のコーティングフィルムは大気中に１ケ月放置しても発
錆は見られない。(Example) (1) Carbonyl iron powder with an average particle size of 5 μm and acrylic resin as an organic binder were mixed at a weight ratio of 100:20, a solvent was added, and the mixture was coated on a PET film to form a mixture of approximately 0.2 Formed a shield layer for the crane. As a result of measuring the shielding effect of this sheet, the magnetic field of 700G (magnetic field source size 5flφ) was reduced by about 12%. Note that this coating film showed no rusting even after being left in the atmosphere for one month.
（２）平均粒径５μのカルボニル鉄粉と有機バインダー
としてのスチレン樹脂とを重量比で１００：２０混合し
て、加熱プレスして、０．５鶴のシートを形成して、そ
のシールド効果を測定した結果、７００Ｇ（磁場源の大
きさ５Ｈφ）を約３０％減少させた。（１）と同様大気
中で１ケ月放置したが錆は認められない。(2) Carbonyl iron powder with an average particle size of 5μ and styrene resin as an organic binder are mixed at a weight ratio of 100:20, and heated and pressed to form a sheet of 0.5 tsuru to obtain its shielding effect. As a result of measurement, 700G (magnetic field source size 5Hφ) was reduced by about 30%. Similar to (1), it was left in the atmosphere for one month, but no rust was observed.
（効果）
以上述べたごとく、本発明になる磁気シールドシートは
、大きなシールド効果を持ち、しかも可撓性に富んでい
て、しかも、安価であるという特徴を有している。(Effects) As described above, the magnetic shielding sheet according to the present invention has the characteristics of having a large shielding effect, being highly flexible, and being inexpensive.
図はカルボニル鉄粉重量％に対するカットオフ磁束の関
係を示すグラフ図である。The figure is a graph showing the relationship between the cutoff magnetic flux and the weight percent of carbonyl iron powder.
Claims (3)
比で２０％以上を含む少くとも有機バインダーとの混合
体を紙あるいは樹脂フィルム上にシート状に配した磁気
シールドシート。(1) A magnetic shielding sheet in which a mixture of carbonyl iron powder having an average particle size of 3 to 10 μm and at least an organic binder containing 20% or more by weight is arranged in a sheet form on paper or a resin film.
は樹脂フィルム上に塗布する請求項（１）の磁気シール
ドシート。(2) The magnetic shield sheet according to claim 1, wherein the mixture is made into a paint using a solvent and applied onto the paper or resin film.
ィルム上にシート状にした請求項（１）の磁気シールド
シート。(3) The magnetic shielding sheet according to claim (1), wherein the mixture is thermally deformed to form a sheet on the paper or resin film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63088967A JP2671368B2 (en) | 1988-04-13 | 1988-04-13 | Magnetic shield sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63088967A JP2671368B2 (en) | 1988-04-13 | 1988-04-13 | Magnetic shield sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01261897A true JPH01261897A (en) | 1989-10-18 |
| JP2671368B2 JP2671368B2 (en) | 1997-10-29 |
Family
ID=13957587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63088967A Expired - Lifetime JP2671368B2 (en) | 1988-04-13 | 1988-04-13 | Magnetic shield sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2671368B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05327275A (en) * | 1992-01-02 | 1993-12-10 | Internatl Business Mach Corp <Ibm> | Electromagnetic shield and manufacture thereof |
| JP2018203812A (en) * | 2017-05-30 | 2018-12-27 | 日立化成株式会社 | Sheet |
| WO2022118916A1 (en) | 2020-12-04 | 2022-06-09 | 昭和電工マテリアルズ株式会社 | Paste |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5998841A (en) * | 1982-10-25 | 1984-06-07 | アライド・コ−ポレ−ション | Polymer composite body, which has emi/rfi shielding layer and can be pressed by die |
| JPS61500338A (en) * | 1983-11-07 | 1986-02-27 | ザ ダウ ケミカル カンパニ− | Low density electromagnetic radiation absorbing composition |
| JPS6197998A (en) * | 1984-10-19 | 1986-05-16 | ティーディーケイ株式会社 | Electromagnetic shield material |
| JPS61137699U (en) * | 1985-02-14 | 1986-08-27 |
-
1988
- 1988-04-13 JP JP63088967A patent/JP2671368B2/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5998841A (en) * | 1982-10-25 | 1984-06-07 | アライド・コ−ポレ−ション | Polymer composite body, which has emi/rfi shielding layer and can be pressed by die |
| JPS61500338A (en) * | 1983-11-07 | 1986-02-27 | ザ ダウ ケミカル カンパニ− | Low density electromagnetic radiation absorbing composition |
| JPS6197998A (en) * | 1984-10-19 | 1986-05-16 | ティーディーケイ株式会社 | Electromagnetic shield material |
| JPS61137699U (en) * | 1985-02-14 | 1986-08-27 |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05327275A (en) * | 1992-01-02 | 1993-12-10 | Internatl Business Mach Corp <Ibm> | Electromagnetic shield and manufacture thereof |
| JPH07123197B2 (en) * | 1992-01-02 | 1995-12-25 | インターナショナル・ビジネス・マシーンズ・コーポレイション | Electromagnetic shield and manufacturing method thereof |
| US5571991A (en) * | 1992-01-02 | 1996-11-05 | International Business Machines Corporation | Electro-magnetic shielding structure having surface layers connected to each other at edges |
| US5714102A (en) * | 1992-01-02 | 1998-02-03 | International Business Machines Corporation | Method for manufacturing electro-magnetic shield having multiple polymeric layers of differing fill compositions |
| JP2018203812A (en) * | 2017-05-30 | 2018-12-27 | 日立化成株式会社 | Sheet |
| WO2022118916A1 (en) | 2020-12-04 | 2022-06-09 | 昭和電工マテリアルズ株式会社 | Paste |
| KR20230114270A (en) | 2020-12-04 | 2023-08-01 | 가부시끼가이샤 레조낙 | paste |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2671368B2 (en) | 1997-10-29 |
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