JP2020025093A - Radio wave absorption sheet - Google Patents
Radio wave absorption sheet Download PDFInfo
- Publication number
- JP2020025093A JP2020025093A JP2019136019A JP2019136019A JP2020025093A JP 2020025093 A JP2020025093 A JP 2020025093A JP 2019136019 A JP2019136019 A JP 2019136019A JP 2019136019 A JP2019136019 A JP 2019136019A JP 2020025093 A JP2020025093 A JP 2020025093A
- Authority
- JP
- Japan
- Prior art keywords
- radio wave
- wave absorbing
- absorbing sheet
- nonwoven fabric
- metal layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000010521 absorption reaction Methods 0.000 title claims abstract description 36
- 229910052751 metal Inorganic materials 0.000 claims abstract description 57
- 239000002184 metal Substances 0.000 claims abstract description 57
- 239000000835 fiber Substances 0.000 claims abstract description 33
- 239000004745 nonwoven fabric Substances 0.000 claims description 45
- 239000003562 lightweight material Substances 0.000 abstract description 5
- 239000010410 layer Substances 0.000 description 50
- 239000012811 non-conductive material Substances 0.000 description 11
- 230000005540 biological transmission Effects 0.000 description 10
- 238000000034 method Methods 0.000 description 10
- 238000002844 melting Methods 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 239000004743 Polypropylene Substances 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 238000011156 evaluation Methods 0.000 description 5
- 229920000728 polyester Polymers 0.000 description 5
- -1 polypropylene Polymers 0.000 description 5
- 229920001155 polypropylene Polymers 0.000 description 5
- 239000004952 Polyamide Substances 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229920001971 elastomer Polymers 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 229920002647 polyamide Polymers 0.000 description 4
- 239000005060 rubber Substances 0.000 description 4
- 238000004544 sputter deposition Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 229910000570 Cupronickel Inorganic materials 0.000 description 3
- 230000002745 absorbent Effects 0.000 description 3
- 239000002250 absorbent Substances 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 238000004891 communication Methods 0.000 description 3
- YOCUPQPZWBBYIX-UHFFFAOYSA-N copper nickel Chemical compound [Ni].[Cu] YOCUPQPZWBBYIX-UHFFFAOYSA-N 0.000 description 3
- 239000004744 fabric Substances 0.000 description 3
- 238000001755 magnetron sputter deposition Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 238000004876 x-ray fluorescence Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000012510 hollow fiber Substances 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 239000011241 protective layer Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000011088 calibration curve Methods 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000007733 ion plating Methods 0.000 description 1
- 238000001659 ion-beam spectroscopy Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- PXHVJJICTQNCMI-LZFNBGRKSA-N nickel-65 Chemical compound [65Ni] PXHVJJICTQNCMI-LZFNBGRKSA-N 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Landscapes
- Laminated Bodies (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
- Nonwoven Fabrics (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Abstract
Description
本発明は、電波吸収シート等に関する。 The present invention relates to a radio wave absorbing sheet and the like.
従来、携帯通信機器、電子機器、家庭用電化製品では、電波の漏洩や侵入を防止するために、電波吸収材料を施した部材が用いられている。近年では、特に電波を利用した電子機器（情報通信機器）においては、他の電子機器の誤作動及び信号劣化の防止、並びに、人体への悪影響の防止の観点から、不要な電磁波を吸収する電波吸収シートが広く採用されている。 2. Description of the Related Art Conventionally, members provided with a radio wave absorbing material have been used in portable communication devices, electronic devices, and household appliances in order to prevent leakage or intrusion of radio waves. In recent years, particularly in electronic devices (information communication devices) using radio waves, radio waves that absorb unnecessary electromagnetic waves from the viewpoint of preventing malfunctions and signal deterioration of other electronic devices and preventing adverse effects on the human body. Absorbent sheets are widely used.
電波吸収シートとしては、各種ゴムや樹脂材料に磁性体金属粉を分散させてなるものが従来から用いられている。また、例えば、布帛の表面上に金属が付着されたノイズ吸収布帛が報告されている（特許文献１）。 As a radio wave absorbing sheet, a sheet formed by dispersing a magnetic metal powder in various rubbers or resin materials has been conventionally used. Also, for example, a noise-absorbing fabric in which a metal is attached on the surface of the fabric has been reported (Patent Document 1).
本発明者は、研究を進める中で、ゴム系電波吸収シートは、重く厚みがあり、凸凹表面やＲの筐体の角などに対応させるために伸長すると電波吸収特性が悪化するという問題がある点に着目した。また、本発明者は、さらに研究を進める中で、布帛に金属を付着してなる従来の電波吸収シートは、比較的軽量であるものの、伸縮性が十分ではなく、凸凹表面やＲの筐体の角などには対応できないことに着目した。 In the course of research, the present inventor has a problem that the rubber-based radio wave absorption sheet is heavy and thick, and the radio wave absorption characteristics are deteriorated if the rubber radio wave absorption sheet is stretched to correspond to the uneven surface or the corner of the R case. We paid attention to the point. In addition, the present inventor has been conducting further research, and the conventional radio wave absorbing sheet formed by attaching a metal to a fabric is relatively lightweight, but has insufficient elasticity, and has an uneven surface or an R-shaped casing. We noticed that we could not handle the corners.
上記着目点に基づいて、本発明は、軽量素材を用いた、伸縮性がより優れた電波吸収シートを提供することを課題とする。好ましくは、本発明は、軽量素材を用いた、伸縮性に加えて耐伸長性（伸長後の電波吸収特性）にもより優れた電波吸収シートを提供することを課題とする。 It is an object of the present invention to provide a radio wave absorbing sheet using a lightweight material and having more excellent elasticity. Preferably, an object of the present invention is to provide a radio wave absorbing sheet using a lightweight material and having more excellent elongation resistance (wave absorption characteristics after elongation) in addition to elasticity.
本発明者は、上記課題に鑑みて鋭意研究を重ねた結果、不織布及び該不織布上に配置されている金属層を含み、且つ前記不織布が捲縮繊維を含む電波吸収シートであれば、上記課題を解決できることを見出した。本発明者はこの知見に基づいてさらに研究を進めた結果、本発明を完成させた。 The present inventor has conducted intensive studies in view of the above problems, and as a result, as long as the radio wave absorbing sheet includes a nonwoven fabric and a metal layer disposed on the nonwoven fabric, and the nonwoven fabric contains crimped fibers, the above problem has been solved. Can be solved. The present inventor has further studied based on this finding, and as a result, completed the present invention.
即ち、本発明は、下記の態様を包含する。 That is, the present invention includes the following embodiments.
項１．
不織布及び該不織布上に配置されている金属層を含み、且つ前記不織布が捲縮繊維を含む、電波吸収シート。
Item 1.
An electromagnetic wave absorbing sheet comprising a nonwoven fabric and a metal layer disposed on the nonwoven fabric, wherein the nonwoven fabric contains crimped fibers.
項２．
前記電波吸収シートの、ＪＩＳ Ｌ １９１３：２０１０に従って測定される任意の一方向の伸長率が、８０〜３００％である、項１に記載の電波吸収シート。
Item 2.
Item 2. The radio wave absorbing sheet according to item 1, wherein the elongation percentage in any one direction of the radio wave absorbing sheet measured in accordance with JIS L 1913: 2010 is 80 to 300%.
項３．
前記電波吸収シートの坪量が８０〜１００ｇ／ｍ２である、項１又は２に記載の電波吸収シート。
Item 3.
Item 3. The radio wave absorbing sheet according to Item 1 or 2, wherein the radio wave absorbing sheet has a basis weight of 80 to 100 g / m 2 .
項４．
前記電波吸収シートの厚みが０．３〜２．０ｍｍである、項１〜３のいずれかに記載の電波吸収シート。
Item 4.
Item 4. The radio wave absorbing sheet according to any one of Items 1 to 3, wherein the thickness of the radio wave absorbing sheet is 0.3 to 2.0 mm.
項５．
前記金属層の厚みが８０〜２５０ｎｍである、項１〜４のいずれかに記載の電波吸収シート。
Item 5.
Item 5. The radio wave absorbing sheet according to any one of Items 1 to 4, wherein the metal layer has a thickness of 80 to 250 nm.
項６．
抵抗値が１０〜１００００Ω／□である、項１〜５のいずれかに記載の電波吸収シート。
Item 6.
Item 6. The radio wave absorbing sheet according to any one of Items 1 to 5, having a resistance value of 10 to 10000 Ω / □.
本発明によれば、軽量素材を用いた、伸縮性がより優れた電波吸収シートを提供することができる。また、本発明は、軽量素材を用いた、伸縮性に加えて耐伸長性（伸長後の電波吸収特性）にもより優れた電波吸収シートを提供することも可能である。 ADVANTAGE OF THE INVENTION According to this invention, the electromagnetic wave absorption sheet which was excellent in elasticity using a lightweight material can be provided. Further, the present invention can provide a radio wave absorbing sheet using a lightweight material, which is excellent not only in stretchability but also in elongation resistance (wave absorption characteristics after elongation).
本明細書中において、「含有」及び「含む」なる表現については、「含有」、「含む」、「実質的にからなる」及び「のみからなる」という概念を含む。 In this specification, the expressions “contain” and “include” include the concepts of “contain”, “include”, “consisting essentially of”, and “consisting only of”.
本発明はその一態様において、不織布及び該不織布上に配置されている金属層を含み、且つ前記不織布が捲縮繊維を含む、電波吸収シート（本明細書において、「本発明の電波吸収シート」と示すこともある。）に関する。以下に、これについて説明する。なお、本発明の電波吸収シートにおいては、不織布に対して金層層側を「上」側とし、反対に不織布側を「下」側とする。 In one embodiment of the present invention, a radio wave absorbing sheet (hereinafter referred to as “the radio wave absorbing sheet of the present invention”) includes a nonwoven fabric and a metal layer disposed on the nonwoven fabric, and the nonwoven fabric includes crimped fibers. May be indicated as "). Hereinafter, this will be described. In the radio wave absorbing sheet of the present invention, the gold layer side is referred to as “upper side” with respect to the nonwoven fabric, and the nonwoven fabric side is referred to as “lower” side with respect to the nonwoven fabric.
＜１．不織布＞
不織布は、捲縮繊維を含むものであれば、特に制限されない。不織布は、本発明の効果が著しく損なわれない限りにおいて、捲縮繊維以外の成分が含まれていてもよい。その場合、不織布中の捲縮繊維の合計量は、例えば８０質量％以上、好ましくは９０質量％以上、より好ましくは９５質量％以上、さらに好ましくは９９質量％以上であり、通常１００質量％未満である。
<1. Non-woven fabric>
The nonwoven fabric is not particularly limited as long as it contains crimped fibers. The nonwoven fabric may contain components other than the crimped fiber as long as the effects of the present invention are not significantly impaired. In that case, the total amount of crimped fibers in the nonwoven fabric is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 99% by mass or more, and usually less than 100% by mass. It is.
不織布の層構成は特に制限されない。不織布は、１種単独の不織布から構成されるものであってもよいし、２種以上の不織布が複数組み合わされたものであってもよい。 The layer configuration of the nonwoven fabric is not particularly limited. The nonwoven fabric may be a single nonwoven fabric, or may be a combination of two or more nonwoven fabrics.
捲縮繊維は、捲縮部位を有する繊維である限り、特に制限されない。捲縮繊維の捲縮数は２山／２５ｍｍ以上であることが好ましい。捲縮数が２山／２５ｍｍ以上である捲縮繊維を用いることにより、本発明の優れた効果をより発揮することができる。上記捲縮数は５山／２５ｍｍ以上であることがより好ましく、２５山／２５ｍｍ以上であることが更に好ましく、５０山／２５ｍｍ以上であることが更に好ましく、９０山／２５ｍｍ以上であることが特に好ましい。上記捲縮数の上限は、例えば３００山／２５ｍｍ以下、、好ましくは２５０山／２５ｍｍ以下、より好ましくは２００山／２５ｍｍ、さらに好ましくは１５０山／２５ｍｍ以下である。上記捲縮数の上限以下であることで、捲縮繊維間の接触が生じやすくなり、金属層の導通性がより優れる。このため、電波吸収シートの抵抗値調整が容易になり、電波吸収性により優れる。 The crimped fiber is not particularly limited as long as it is a fiber having a crimped portion. The number of crimps of the crimped fiber is preferably 2 ridges / 25 mm or more. By using crimped fibers having a number of crimps of 2 ridges / 25 mm or more, the excellent effects of the present invention can be further exhibited. The number of crimps is more preferably 5 peaks / 25 mm or more, further preferably 25 peaks / 25 mm or more, further preferably 50 peaks / 25 mm or more, and preferably 90 peaks / 25 mm or more. Particularly preferred. The upper limit of the number of crimps is, for example, 300 peaks / 25 mm or less, preferably 250 peaks / 25 mm or less, more preferably 200 peaks / 25 mm, and still more preferably 150 peaks / 25 mm or less. When the number of the crimps is equal to or less than the upper limit, contact between the crimped fibers easily occurs, and the conductivity of the metal layer is more excellent. For this reason, the resistance value of the radio wave absorbing sheet can be easily adjusted, and the radio wave absorbing sheet is more excellent.
捲縮繊維は、通常、潜在捲縮繊維を加熱処理して捲縮させることにより、得ることができる。潜在捲縮繊維は、熱処理により立体捲縮を発現する繊維である。潜在捲縮繊維としては、例えば、融点の異なる複数の樹脂からなる複合繊維、単一成分からなる偏心中空繊維や繊維の一部に特定の熱履歴を施した繊維が使用される。複合繊維には、例えば、偏心型の芯鞘構造のものや、サイドバイサイド型の繊維が好適に用いられる。融点の異なる樹脂の組合せとして、ポリエステル−低融点ポリエステル、ポリアミド−低融点ポリアミド、ポリエステル−ポリアミド、ポリエステル−ポリプロピレン、ポリプロピレン−低融点ポリプロピレン、ポリプロピレン−ポリエチレンなど種々の合成樹脂を組み合わせたものが使用できる。特に、ポリエステル−低融点ポリエステル若しくはポリプロピレン−低融点ポリプロピレンの組合せからなる潜在捲縮繊維は、化学的な耐性と伸度特性の点で優れており好ましい。また、偏心中空繊維としては、ポリエステル、ポリアミド、ポリプロピレンやポリエチレンなどが使用できるが、特にポリエステル若しくはポリプロピレンが化学的な耐性と伸度特性の点で優れており好ましい。繊維の一部に特定の熱履歴を施した潜在捲縮繊維としては、例えば熱刃などにポリエステル、ポリアミド、ポリアクリルなどの熱可塑性樹脂からなる繊維の一側面をあてながら通過させたものが使用できる。 The crimped fiber can usually be obtained by heat-treating the latent crimped fiber to crimp it. Latent crimped fibers are fibers that develop a three-dimensional crimp by heat treatment. As the latently crimped fiber, for example, a composite fiber composed of a plurality of resins having different melting points, an eccentric hollow fiber composed of a single component, or a fiber obtained by subjecting a part of the fiber to a specific heat history is used. As the composite fiber, for example, an eccentric type core-sheath structure or a side-by-side type fiber is suitably used. As a combination of resins having different melting points, a combination of various synthetic resins such as polyester-low-melting polyester, polyamide-low-melting polyamide, polyester-polyamide, polyester-polypropylene, polypropylene-low-melting polypropylene, and polypropylene-polyethylene can be used. In particular, latently crimped fibers composed of a combination of polyester-low melting point polyester or polypropylene-low melting point polypropylene are preferable because of their excellent chemical resistance and elongation characteristics. As the eccentric hollow fiber, polyester, polyamide, polypropylene, polyethylene, or the like can be used, but polyester or polypropylene is particularly preferable because of its excellent chemical resistance and elongation characteristics. As the latently crimped fiber in which a specific heat history is applied to a part of the fiber, for example, a fiber that is made to pass while applying one side of a fiber made of a thermoplastic resin such as polyester, polyamide, or polyacryl to a hot blade is used. it can.
捲縮繊維及び潜在権縮繊維は、それぞれ、１種単独であってもよいし、２種以上の組み合わせであってもよい。 Each of the crimped fiber and the latently crimped fiber may be a single type or a combination of two or more types.
本発明で用いられる不織布は、例えば、潜在捲縮繊維を含む不織布を加熱することにより、立体捲縮を発現させることにより、得ることができる。 The nonwoven fabric used in the present invention can be obtained, for example, by heating a nonwoven fabric containing latently crimped fibers to develop a three-dimensional crimp.
不織布の坪量（目付）は、例えば１０〜２００ｇ／ｍ２である。該坪量（目付）は、電波吸収特性、耐伸長性等の観点から、好ましくは４０〜１５０ｇ／ｍ２、より好ましくは８０〜１００ｇ／ｍ２である。 The basis weight (basis weight) of the nonwoven fabric is, for example, 10 to 200 g / m 2 .該坪amount (basis weight), the radio wave absorption characteristics, in terms of stretch-resistance or the like, preferably 40~150g / m 2, more preferably 80-100 g / m 2.
不織布の厚みは、例えば０．１〜３．０ｍｍ、好ましくは０．３〜２．０ｍｍである。 The thickness of the nonwoven fabric is, for example, 0.1 to 3.0 mm, preferably 0.3 to 2.0 mm.
不織布の、ＪＩＳ Ｌ １９１３：２０１０に従って測定される任意の一方向の伸長率は、例えば５０〜５００％である。該伸長率は、伸縮性、電波吸収特性等の観点から、好ましくは８０〜４００％、より好ましくは１００〜３００％である。 The elongation in any one direction of the nonwoven fabric measured according to JIS L 1913: 2010 is, for example, 50 to 500%. The elongation percentage is preferably 80 to 400%, more preferably 100 to 300%, from the viewpoint of stretchability, radio wave absorption characteristics and the like.
＜２．金属層＞
金属層は、不織布上に配置される、換言すれば不織布の有する２つの主面の少なくとも１方の表面上に配置される。
<2. Metal layer>
The metal layer is disposed on the nonwoven fabric, in other words, on at least one of the two main surfaces of the nonwoven fabric.
金属層は、金属を素材として含む層である限り、特に制限されない。金属層は、本発明の効果が著しく損なわれない限りにおいて、金属以外の成分が含まれていてもよい。その場合、金属層中の金属量は、例えば８０質量％以上、好ましくは９０質量％以上、より好ましくは９５質量％以上、さらに好ましくは９９質量％以上であり、通常１００質量％未満である。 The metal layer is not particularly limited as long as it is a layer containing a metal as a material. The metal layer may contain components other than metal as long as the effects of the present invention are not significantly impaired. In that case, the amount of metal in the metal layer is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 99% by mass or more, and usually less than 100% by mass.
金属層を構成する金属としては、電波吸収特性を発揮できるものであれば特に制限されない。金属としては、例えば金、銀、銅、亜鉛、ニッケル、スズ、アルミニウム、チタン、白金、鉄、これらの金属を含む合金等が挙げられる。これらの中でも、電波吸収特性、経済コスト等の観点から、好ましくは銅、銅−ニッケル合金、銀、アルミ、ステンレス等が挙げられる。 The metal constituting the metal layer is not particularly limited as long as it can exhibit radio wave absorption characteristics. Examples of the metal include gold, silver, copper, zinc, nickel, tin, aluminum, titanium, platinum, iron, and alloys containing these metals. Among them, preferred are copper, copper-nickel alloy, silver, aluminum, stainless steel, and the like from the viewpoints of radio wave absorption characteristics and economic costs.
金属層の層構成は特に制限されない。金属層は、１層からなる単層であってもよいし、同一又は異なる組成を有する複数の層であってもよい。金属層は、本発明の好ましい一態様においては、電波吸収特性の観点から選択される上記金属を主成分とする金属層（金属層ａ）と、該金属層の片側又は両側に配置される耐腐食性の観点から選択される金属（例えば、ニッケル、チタン、クロム、シリコン、アルミ等）を主成分とする金属層（金属層ｂ）とを含む複数の層から構成されていることが、耐湿熱性の観点から望ましい。金属層の層構成は、電波吸収シートの上側から順に、金属層ｂ／金属層ａとなる層構成であることがより好ましく、金属層ｂ／金属層ａ／金属層ｂとなる層構成であることが更に好ましい。
また、金属層は、その２つの主面の一方或いは両方において、表面が酸化皮膜等の皮膜で構成されていてもよい。
The layer configuration of the metal layer is not particularly limited. The metal layer may be a single layer composed of one layer or a plurality of layers having the same or different compositions. In a preferred embodiment of the present invention, the metal layer has a metal layer (metal layer a) containing the above-described metal as a main component selected from the viewpoint of radio wave absorption characteristics, and a metal layer provided on one or both sides of the metal layer. It is composed of a plurality of layers including a metal layer (metal layer b) mainly containing a metal selected from the viewpoint of corrosiveness (eg, nickel, titanium, chromium, silicon, aluminum, etc.). Desirable from the viewpoint of thermal properties. The layer configuration of the metal layer is more preferably a layer configuration of metal layer b / metal layer a in order from the upper side of the radio wave absorbing sheet, and is a layer configuration of metal layer b / metal layer a / metal layer b. Is more preferred.
In addition, the surface of the metal layer may be formed of a film such as an oxide film on one or both of the two main surfaces.
金属は、１種単独であってもよいし、２種以上の組み合わせであってもよい。 The metal may be used alone or in combination of two or more.
金属層の厚みは、例えば５０ｎｍ以上、好ましくは１００ｎｍ以上、より好ましくは２００ｎｍ以上、さらに好ましくは３００ｎｍ以上、よりさらに好ましくは３００〜４００ｎｍである。耐湿熱性の観点からは、より厚い（例えば２００ｎｍ以上、３００ｎｍ以上等である）ことが好ましい。該厚みの上限は、特に制限されず、例えば１０００ｎｍ、６００ｎｍ、４００ｎｍである。 The thickness of the metal layer is, for example, 50 nm or more, preferably 100 nm or more, more preferably 200 nm or more, further preferably 300 nm or more, and even more preferably 300 to 400 nm. From the viewpoint of wet heat resistance, the thickness is preferably thicker (for example, 200 nm or more, 300 nm or more). The upper limit of the thickness is not particularly limited, and is, for example, 1000 nm, 600 nm, and 400 nm.
金属層において、上記した金属層ａの厚みは、好ましくは５０〜３００ｎｍ、より好ましくは８０〜２００ｎｍである。また、上記した金属層ｂの厚みは、耐湿熱性等の観点から、好ましくは５０〜３００ｎｍ、より好ましくは８０〜２００ｎｍ、さらに好ましくは１３０〜２００ｎｍである。 In the metal layer, the thickness of the above-mentioned metal layer a is preferably 50 to 300 nm, more preferably 80 to 200 nm. In addition, the thickness of the metal layer b is preferably 50 to 300 nm, more preferably 80 to 200 nm, and still more preferably 130 to 200 nm from the viewpoint of wet heat resistance and the like.
金属層の厚みは、蛍光X線分析により求めることができる。具体的には、走査型蛍光X線分析装置（例えば、リガク社製走査型蛍光X線分析装置ZSX PrimusIII＋もしくは、同等品）を用いて加速電圧は５０ｋＶ、加速電流は５０ｍＡ、積分時間は６０秒として分析する。測定対象の成分のＫα線のＸ線強度を測定し、ピーク位置に加えてバックグラウンド位置での強度も測定し、正味の強度が算出できるようにする。あらかじめ作成した検量線から、測定した強度値を厚みに換算することができる。
同一のサンプルに５回分析を行い、その平均値を平均厚みとする。
The thickness of the metal layer can be determined by X-ray fluorescence analysis. Specifically, the acceleration voltage is 50 kV, the acceleration current is 50 mA, and the integration time is 60 seconds using a scanning X-ray fluorescence analyzer (for example, a scanning X-ray fluorescence analyzer ZSX PrimusIII + manufactured by Rigaku Corporation). Analyzed as The X-ray intensity of the Kα ray of the component to be measured is measured, and the intensity at the background position is also measured in addition to the peak position, so that the net intensity can be calculated. From the calibration curve created in advance, the measured intensity value can be converted into a thickness.
The same sample is analyzed five times, and the average value is defined as the average thickness.
＜３．構成、特性等＞
本発明の電波吸収シートの坪量（目付）は、例えば１０〜２００ｇ／ｍ２である。該坪量（目付）は、電波吸収特性、耐伸長性等の観点から、好ましくは４０〜１５０ｇ／ｍ２、より好ましくは８０〜１００ｇ／ｍ２である。
<3. Configuration, characteristics, etc.>
The basis weight (basis weight) of the radio wave absorbing sheet of the present invention is, for example, 10 to 200 g / m 2 .該坪amount (basis weight), the radio wave absorption characteristics, in terms of stretch-resistance or the like, preferably 40~150g / m 2, more preferably 80-100 g / m 2.
本発明の電波吸収シートの厚みは、例えば０．１〜３．０ｍｍ、好ましくは０．３〜２．０ｍｍである。 The thickness of the radio wave absorbing sheet of the present invention is, for example, 0.1 to 3.0 mm, preferably 0.3 to 2.0 mm.
電波吸収シートの厚みは、ＪＩＳ Ｌ １９１３：２０１０ Ａ法に従い、幅１ｍ内の１０箇所の厚みを測定し、その平均値を厚みとする。 The thickness of the radio wave absorbing sheet is measured at 10 points within a width of 1 m according to JIS L 1913: 2010 A method, and the average value is defined as the thickness.
本発明の電波吸収シートは、伸縮性に優れる。例えば、本発明の電波吸収シートの、ＪＩＳ Ｌ １９１３：２０１０に従って測定される任意の一方向の伸長率は、例えば５０〜４００％である。該伸長率は、伸縮性及び電波吸収特性の両立、耐伸張性等の観点から、好ましくは８０〜３００％、より好ましくは１００〜２５０％である。 The radio wave absorbing sheet of the present invention is excellent in elasticity. For example, the elongation rate in any one direction of the radio wave absorbing sheet of the present invention measured in accordance with JIS L 1913: 2010 is, for example, 50 to 400%. The elongation is preferably from 80 to 300%, more preferably from 100 to 250%, from the viewpoint of compatibility between elasticity and radio wave absorption characteristics, and elongation resistance.
上記伸長率であることで、凸凹表面やＲの筐体の角などへの追従性が一層向上する。また、伸長や変形によって生じる残留応力が比較的小さくなるため、形状保持性にも優れる。 With the above elongation rate, the followability of the uneven surface and the corner of the R to the corner is further improved. In addition, since the residual stress caused by elongation or deformation is relatively small, the shape retention is excellent.
本発明の電波吸収シートの抵抗値（表面抵抗）は、例えば１０〜１００００Ω／□である。抵抗値は、吸収する電波の周波数により適宜調整される。例えば、１．５〜６ＧＨｚに対しては２０〜１１０Ω／□が好ましい。表面抵抗は、表面抵抗計（ＭＩＴＵＢＩＳＨＩ ＣＨＥＭＩＣＡＬ ＡＮＡＬＹＴＥＣＨ社製、商品名：Ｌｏｒｅｓｔａ−ＥＰ）を用いて４端子法により測定することができる。上記抵抗値であることで、電波吸収シートで対象周波数の電波が反射されることを抑制することができ、かつ、電波吸収性能により優れる。 The electric wave absorbing sheet of the present invention has a resistance (surface resistance) of, for example, 10 to 10000 Ω / □. The resistance value is appropriately adjusted according to the frequency of the radio wave to be absorbed. For example, for 1.5 to 6 GHz, 20 to 110 Ω / □ is preferable. The surface resistance can be measured by a four-terminal method using a surface resistance meter (manufactured by MITUBISHI CHEMICAL ANALYTECH, trade name: Loresta-EP). By having the above resistance value, it is possible to suppress the reflection of the radio wave of the target frequency on the radio wave absorbing sheet, and it is more excellent in the radio wave absorbing performance.
＜４．製造方法＞
本発明の電波吸収シートは、不織布の表面に金属層を付着させる工程を含む方法により得ることができる。金属層が複数の層から構成される場合は、さらに、最外層の金属層の表面に別の金属層を付着させる工程を含む方法により、得ることができる。
<4. Manufacturing method>
The radio wave absorbing sheet of the present invention can be obtained by a method including a step of attaching a metal layer to the surface of a nonwoven fabric. When the metal layer is composed of a plurality of layers, it can be further obtained by a method including a step of attaching another metal layer to the surface of the outermost metal layer.
特に限定されないが、前記付着は、例えば、スパッタリング法、真空蒸着法、イオンプレーティング法、化学蒸着法、パルスレーザーデポジション法等により行うことができる。これらの中でも、膜厚制御性の観点から、スパッタリング法が好ましい。 Although not particularly limited, the attachment can be performed by, for example, a sputtering method, a vacuum evaporation method, an ion plating method, a chemical vapor deposition method, a pulse laser deposition method, or the like. Among them, the sputtering method is preferable from the viewpoint of the film thickness controllability.
スパッタリング法としては、特に限定されないが、例えば、直流マグネトロンスパッタ、高周波マグネトロンスパッタ及びイオンビームスパッタ等が挙げられる。また、スパッタ装置は、バッチ方式であってもロール・ツー・ロール方式であってもよい。 The sputtering method is not particularly limited, and examples thereof include DC magnetron sputtering, high-frequency magnetron sputtering, and ion beam sputtering. Further, the sputtering apparatus may be of a batch type or a roll-to-roll type.
＜５．用途＞
本発明の電波吸収シートは電波吸収特性に優れるため、電波対策部材として好適に利用できる。例えば、光トランシーバや、次世代移動通信システム（５Ｇ）、自動車、道路、人の相互間で情報通信を行う高度道路交通システム（ＩＴＳ）等の用途において、電波干渉抑制やノイズ低減の目的で用いることができる。本発明の電波吸収シートが対象とする電波の周波数は、例えば１．５ＧＨｚ以上６ＧＨｚ以下である。
<5. Applications>
Since the radio wave absorbing sheet of the present invention has excellent radio wave absorbing properties, it can be suitably used as a radio wave countermeasure member. For example, in applications such as an optical transceiver, a next-generation mobile communication system (5G), an intelligent transportation system (ITS) for performing information communication between automobiles, roads, and people, it is used for the purpose of suppressing radio interference and reducing noise. be able to. The frequency of the radio wave targeted by the radio wave absorbing sheet of the present invention is, for example, 1.5 GHz or more and 6 GHz or less.
本発明の電波吸収シートは、電波吸収対象物の周囲を覆うことにより使用することができる。このため、対象物の形状に応じて、適宜成形される。成形されたものを、本明細書においては、「電波吸収成形体」と表す。 The radio wave absorbing sheet of the present invention can be used by covering the periphery of a radio wave absorbing object. For this reason, it is appropriately molded according to the shape of the object. The molded product is referred to as a “wave-absorbing molded product” in this specification.
電波吸収対象物としては特に限定されない。電波吸収対象物としては例えば、ＬＳＩ等の電子部品、ガラスエポキシ基盤及びFPC等の回路表面又はその裏面、部品間の接続ケーブル及びコネクター部、電子部品・装置を入れる筐体、保持体等の裏又は表、電源線、伝送線等のケーブル等が挙げられる。 The radio wave absorption target is not particularly limited. Examples of the electromagnetic wave absorption target include electronic components such as LSIs, glass epoxy substrates and circuit surfaces such as FPCs and the like, or the back surface thereof, connecting cables and connectors between components, housings for electronic components and devices, and the back of housings and the like. Alternatively, a cable such as a table, a power line, a transmission line, or the like may be used.
周囲を覆う方法は特に限定されず、巻き付け、貼付などが挙げられる。 The method of covering the periphery is not particularly limited, and examples thereof include winding and sticking.
本発明の電波吸収成形体は、その一態様において、非導電性材料をさらに含む。該非導電性材料を含むことにより、成形体の形状保持性を高めることができる。 In one aspect, the radio wave absorption molded article of the present invention further includes a non-conductive material. By including the non-conductive material, the shape retention of the molded body can be improved.
本発明の電波吸収シートは、接着剤等を介して種々の非導電性材料からなる部材に貼付することにより、優れた電波吸収性を有する電波吸収成形体を得ることができる。なかでも、電子デバイスを内蔵するための筐体を、非導電性材料を用いて製造する際に、筐体の表面に貼着して電波吸収を付与する用途に好適である。非導電性材料からなる部材の表面に、本発明の電波吸収シートが貼付されている電波吸収成形体もまた、本発明の１つである。非導電性材料からなる部材の表面に本発明の電波吸収シートが貼付された筐体に、電子デバイスが内蔵されている電子デバイスを内蔵する筐体もまた、本発明の１つである。 The electromagnetic wave absorbing sheet of the present invention can obtain a radio wave absorbing molded article having an excellent electromagnetic wave absorbing property by sticking to a member made of various non-conductive materials via an adhesive or the like. In particular, when a housing for incorporating an electronic device is manufactured using a non-conductive material, it is suitable for use in attaching radio wave absorption by attaching to a surface of the housing. A radio wave absorbing molded article in which the radio wave absorbing sheet of the present invention is adhered to the surface of a member made of a non-conductive material is also one of the present invention. A case in which an electronic device is incorporated in a case in which an electronic device is incorporated in a case in which the radio wave absorbing sheet of the present invention is attached to the surface of a member made of a non-conductive material is also one of the present invention.
本発明の電波吸収シートは、非導電性材料からなる部材の表面に貼付するだけでなく、非導電性材料からなる部材の内部に保持することによっても、優れた電波吸収性を有す電波吸収成形体を得ることができる。非導電性材料からなる部材の内部に保持する方法は特に限定されず、インサート成型などが挙げられる。
非導電性材料からなる部材の内部に、本発明の電波吸収シートが保持されている電波吸収成形体もまた、本発明の１つである。非導電性材料からなる部材の内部に本発明の電波吸収シートが保持された筐体に、電子デバイスが内蔵されている電子デバイスを内蔵する筐体もまた、本発明の１つである。
The electromagnetic wave absorbing sheet of the present invention is not only affixed to the surface of a member made of a non-conductive material, but also has an excellent electromagnetic wave absorbing property by being held inside a member made of a non-conductive material. A molded article can be obtained. The method of holding the member inside the member made of a non-conductive material is not particularly limited, and examples include insert molding.
A radio wave absorption molded article in which the radio wave absorption sheet of the present invention is held inside a member made of a non-conductive material is also one of the present invention. A case in which the electronic device is built in the case in which the electronic device is built in the case in which the radio wave absorbing sheet of the present invention is held inside a member made of a non-conductive material is also one of the present invention.
以下に、実施例に基づいて本発明を詳細に説明するが、本発明はこれらの実施例によって限定されるものではない。なお、実施例及び比較例は対象とする電波の周波数が１．５ＧＨｚ〜６ＧＨｚである電波吸収シートを製造した。 Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples. In the examples and comparative examples, radio wave absorbing sheets in which the frequency of the target radio wave was 1.5 GHz to 6 GHz were manufactured.
（１）電波吸収シートの製造
（実施例１）
不織布として、サイドバイサイド型構造を有する捲縮繊維（ＰＥＴ）からなる不織布（スパンレース、山数２４０山／２５ｍｍ、坪量１２５ｇ／ｍ２厚み１．５ｍｍ）を用いた。不織布を真空装置内に設置し、５．０×１０−４Ｐａ以下となるまで真空排気した。続いて、アルゴンガスを導入して、ＤＣマグネトロンスパッタリング法により、不織布の片面に、厚み３０ｎｍの銅−ニッケル合金（銅３５％、ニッケル６５％）からなる保護層、厚み１００ｎｍの銅からなる金属皮膜、及び厚み３０ｎｍの銅−ニッケル合金（銅３５％、ニッケル６５％）からなる保護層をこの順に積層させ、電波吸収シートを得た。
(1) Production of radio wave absorbing sheet (Example 1)
As the nonwoven fabric, it was used a nonwoven fabric made of crimped fibers (PET) having a side-by-side type structure (spunlace, elevated portions 240 Mountain / 25 mm, basis weight 125 g / m 2 thickness 1.5 mm). The nonwoven fabric was placed in a vacuum device and evacuated to a pressure of 5.0 × 10 −4 Pa or less. Subsequently, an argon gas is introduced, and a protective layer made of a 30 nm thick copper-nickel alloy (35% copper, 65% nickel) and a metal film made of 100 nm thick copper are formed on one surface of the nonwoven fabric by DC magnetron sputtering. And a protective layer made of a copper-nickel alloy (copper 35%, nickel 65%) having a thickness of 30 nm was laminated in this order to obtain a radio wave absorbing sheet.
（実施例２〜６）
不織布の坪量、山数及び厚みを変える以外は、実施例１と同様にして電波吸収シートを得た。
(Examples 2 to 6)
A radio wave absorbing sheet was obtained in the same manner as in Example 1 except that the basis weight, the number of peaks, and the thickness of the nonwoven fabric were changed.
（実施例７〜１０）
金属層のうち金属皮膜の厚みを変える以外は、実施例２と同様にして電波吸収シートを得た。
(Examples 7 to 10)
A radio wave absorbing sheet was obtained in the same manner as in Example 2, except that the thickness of the metal film in the metal layer was changed.
（実施例１１）
不織布の坪量、山数、厚み及び金属層のうち金属皮膜の厚みを変える以外は、実施例１と同様にして電波吸収シートを得た。
(Example 11)
A radio wave absorbing sheet was obtained in the same manner as in Example 1 except that the basis weight, the number of peaks, the thickness of the nonwoven fabric, and the thickness of the metal film among the metal layers were changed.
（比較例１〜３）
不織布として、非捲縮繊維からなる不織布を用いる以外は、実施例１と同様にして電波吸収シートを得た。
(Comparative Examples 1 to 3)
A radio wave absorbing sheet was obtained in the same manner as in Example 1, except that a nonwoven fabric made of non-crimped fibers was used as the nonwoven fabric.
（比較例４）
不織布に代えて、ウレタンフィルムを用いる以外は、実施例１と同様にして電波吸収シートを得た。
(Comparative Example 4)
A radio wave absorbing sheet was obtained in the same manner as in Example 1 except that a urethane film was used instead of the nonwoven fabric.
（比較例５）
不織布に代えて、ゴムシートを用いる以外は、実施例１と同様にして電波吸収シートを得た。
(Comparative Example 5)
A radio wave absorbing sheet was obtained in the same manner as in Example 1 except that a rubber sheet was used instead of the nonwoven fabric.
（２）評価
（２−１）抵抗値の測定
得られた電波吸収シートの金属層の表面抵抗値を、表面抵抗計（ＭＩＴＵＢＩＳＨＩ ＣＨＥＭＩＣＡＬ ＡＮＡＬＹＴＥＣＨ社製、商品名：Ｌｏｒｅｓｔａ−ＥＰ）を用いて４端子法により測定した。
(2) Evaluation (2-1) Measurement of Resistance Value The surface resistance value of the metal layer of the obtained electromagnetic wave absorbing sheet was measured by using a surface resistance meter (MITSUBISHI CHEMICAL ANALYTECH Co., Ltd., trade name: Loresta-EP) using four terminals. It was measured by the method.
（２−２）不織布伸長率の測定
ＪＩＳ Ｌ １９１３：２０１０に従い、引張試験機を用いて、不織布が切断（破断）したときの伸びを求め、伸長率を下記の式によって算出した。
伸長率（％）＝１００×（（破断時の不織布長さ）−（引っ張り前の不織布長さ））
(2-2) Measurement of nonwoven fabric elongation rate According to JIS L 1913: 2010, the elongation when the nonwoven fabric was cut (ruptured) was determined using a tensile tester, and the elongation rate was calculated by the following equation.
Elongation rate (%) = 100 × ((length of nonwoven fabric at break) − (length of nonwoven fabric before tension))
（２−３）吸収体伸長率の測定
ＪＩＳ Ｌ １９１３：２０１０に従い、引張試験機を用いて、吸収シートが切断（破断）したときの伸びを求め、伸長率を以下の式によって算出した。
伸長率（％）＝１００×（（破断時吸収シート長さ）−（引っ張り前吸収シート長さ））
(2-3) Measurement of Absorbent Elongation Rate According to JIS L 1913: 2010, the elongation when the absorbent sheet was cut (broken) was determined using a tensile tester, and the elongation rate was calculated by the following equation.
Elongation rate (%) = 100 x ((absorption sheet length at break)-(absorption sheet length before pulling))
（２−４）伸長性の評価
ＪＩＳ Ｌ １９１３：２０１０に従い、引っ張り試験機を用いて、１２０％まで伸長し、そのときに電波吸収シートに破断が起きたかで評価した。評価は以下の基準により判断した。なお伸長方向は、吸収体伸長率の大きい方向を伸長方向とした。
○：伸長時に破れ無し
×：伸長時に破れ有り
(2-4) Evaluation of extensibility In accordance with JIS L 1913: 2010, the elongation up to 120% was performed using a tensile tester, and it was evaluated whether or not the radio wave absorbing sheet was broken at that time. Evaluation was made based on the following criteria. In addition, the extending direction was defined as the direction in which the absorber elongation rate was large.
：: No break during extension ×: Break during extension
（２−５）電波吸収特性（伸長前）の評価
得られた電波吸収シートについて、ＩＥＣ６２３３３規格に準拠したマイクロストリップライン法に従って測定した。具体的には、インピーダンスが５０Ωであるマイクロストリップライン上に１０ｃｍ角に切り出した電波吸収シートを載置し、試料の上から５００ｇの荷重をかけた。次いで、マイクロストリップライン上に、ネットワークアナライザ（Ｈｅｗｌｅｔｔ−Ｐａｃｋａｒｄ製Ｅ８３６１Ａ）より０．１ＧＨｚ〜６．０ＧＨｚの高周波信号を入射し、Ｓパラメータを測定した。測定された試料の積載位置からの反射量：Ｓ１１（ｄＢ）および透過量：Ｓ２１（ｄＢ）を用いて、以下の式（Ａ）より伝送減衰率［Ｒｔｐ］を算出した。
（式Ａ）
Ｒｔｐ［ｄＢ］＝−１０×ｌｏｇ（１０Ｓ２１／１０／１−１０Ｓ１１／１０）
(2-5) Evaluation of radio wave absorption characteristics (before elongation) The obtained radio wave absorption sheet was measured according to the microstrip line method based on the IEC62333 standard. Specifically, a 10 cm square radio wave absorbing sheet cut out was placed on a microstrip line having an impedance of 50Ω, and a load of 500 g was applied from above the sample. Next, a high frequency signal of 0.1 GHz to 6.0 GHz was incident on the microstrip line from a network analyzer (E8361A manufactured by Hewlett-Packard), and the S parameter was measured. Reflection amount from the measured loading position of the sample: S 11 (dB) and the transmission weight: with S 21 a (dB), was calculated transmission attenuation factor [Rtp] from the following formula (A).
(Formula A)
R tp [dB] = − 10 × log (10 S21 / 10 / 1-10 S11 / 10 )
なお、電波吸収特性は以下の基準により評価した。
◎：１．５ＧＨｚ〜６ＧＨｚの周波数帯において、伝送減衰率［Ｒｔｐ］が２０ｄＢ以上
○：１．５ＧＨｚ〜６ＧＨｚの周波数帯において、伝送減衰率［Ｒｔｐ］が２０ｄＢ未満、１０ｄＢ以上
×：１．５ＧＨｚ〜６ＧＨｚの周波数帯において、伝送減衰率［Ｒｔｐ］が１０ｄＢ未満
The radio wave absorption characteristics were evaluated according to the following criteria.
◎: Transmission attenuation rate [R tp ] is 20 dB or more in a frequency band of 1.5 GHz to 6 GHz ：: Transmission attenuation rate [R tp ] is less than 20 dB and 10 dB or more in a frequency band of 1.5 GHz to 6 GHz In a frequency band of 0.5 GHz to 6 GHz, the transmission attenuation rate [R tp ] is less than 10 dB.
（２−６）電波吸収特性（伸長後）の評価
得られた電波吸収シートを１０ｃｍ角に切り出し、対向する二辺間の距離が、伸長前を基準に１２０％になるように伸長、固定した。この状態で、上記（２−５）と同様にしてマイクロストリップライン法にて測定し、伝送減衰率を算出、評価した。なお、電波吸収特性は以下の基準により評価した。なお伸長方向は、吸収体伸長率の大きい方向を伸長方向とした。
◎：１．５ＧＨｚ〜６ＧＨｚの周波数帯において、伝送減衰率［Ｒｔｐ］が２０ｄＢ以上
○：１．５ＧＨｚ〜６ＧＨｚの周波数帯において、伝送減衰率［Ｒｔｐ］が２０ｄＢ未満、１０ｄＢ以上
×：１．５ＧＨｚ〜６ＧＨｚの周波数帯において、伝送減衰率［Ｒｔｐ］が１０ｄＢ未満
−：破れにより測定不能
(2-6) Evaluation of radio wave absorption characteristics (after elongation) The obtained radio wave absorption sheet was cut out into a 10 cm square, and stretched and fixed such that the distance between two opposing sides was 120% based on the length before elongation. . In this state, measurement was performed by the microstrip line method in the same manner as in (2-5) above, and the transmission attenuation rate was calculated and evaluated. The radio wave absorption characteristics were evaluated according to the following criteria. In addition, the extending direction was defined as the direction in which the absorber elongation rate was large.
◎: Transmission attenuation rate [R tp ] is 20 dB or more in a frequency band of 1.5 GHz to 6 GHz ：: Transmission attenuation rate [R tp ] is less than 20 dB and 10 dB or more in a frequency band of 1.5 GHz to 6 GHz In the frequency band of 5 GHz to 6 GHz, the transmission attenuation rate [R tp ] is less than 10 dB.
Claims (6)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018139190 | 2018-07-25 | ||
| JP2018139190 | 2018-07-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2020025093A true JP2020025093A (en) | 2020-02-13 |
Family
ID=69618941
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2019136019A Pending JP2020025093A (en) | 2018-07-25 | 2019-07-24 | Radio wave absorption sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2020025093A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11958308B1 (en) | 2023-05-31 | 2024-04-16 | G13 Innovation In Production Ltd | Thermal paper, and methods and systems for forming the same |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03166797A (en) * | 1989-11-27 | 1991-07-18 | Daiwabo Co Ltd | Knitting for electromagnetic wave shielding |
| JPH04108168A (en) * | 1990-08-24 | 1992-04-09 | Japan Vilene Co Ltd | Electrically conductive fiber sheet |
| JPH04174777A (en) * | 1990-11-02 | 1992-06-22 | Japan Vilene Co Ltd | Conductive fiber sheet and preparation thereof |
| JP2005200794A (en) * | 2004-01-16 | 2005-07-28 | Daiwa Fine Chemicals Co Ltd (Laboratory) | Method for producing metal-covered fabric for preventing electromagnetic disturbance, the metal-covered fabric for preventing the electromagnetic disturbance using the production method, and product for preventing the electromagnetic disturbance using the metal-covered fabric |
| JP2010080911A (en) * | 2008-04-30 | 2010-04-08 | Tayca Corp | Wide band electromagnetic wave absorbing material and method of manufacturing same |
| JP2015162647A (en) * | 2014-02-28 | 2015-09-07 | 東レ株式会社 | electromagnetic wave absorber for microwave region |
-
2019
- 2019-07-24 JP JP2019136019A patent/JP2020025093A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03166797A (en) * | 1989-11-27 | 1991-07-18 | Daiwabo Co Ltd | Knitting for electromagnetic wave shielding |
| JPH04108168A (en) * | 1990-08-24 | 1992-04-09 | Japan Vilene Co Ltd | Electrically conductive fiber sheet |
| JPH04174777A (en) * | 1990-11-02 | 1992-06-22 | Japan Vilene Co Ltd | Conductive fiber sheet and preparation thereof |
| JP2005200794A (en) * | 2004-01-16 | 2005-07-28 | Daiwa Fine Chemicals Co Ltd (Laboratory) | Method for producing metal-covered fabric for preventing electromagnetic disturbance, the metal-covered fabric for preventing the electromagnetic disturbance using the production method, and product for preventing the electromagnetic disturbance using the metal-covered fabric |
| JP2010080911A (en) * | 2008-04-30 | 2010-04-08 | Tayca Corp | Wide band electromagnetic wave absorbing material and method of manufacturing same |
| JP2015162647A (en) * | 2014-02-28 | 2015-09-07 | 東レ株式会社 | electromagnetic wave absorber for microwave region |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11958308B1 (en) | 2023-05-31 | 2024-04-16 | G13 Innovation In Production Ltd | Thermal paper, and methods and systems for forming the same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101399022B1 (en) | Sheet for absorbing electromagnetic wave, manufacturing method thereof and electronic equipment including the same | |
| KR20160072189A (en) | Noise-absorbing sheet | |
| JP2018195854A (en) | Electromagnetic wave-shielding film, and electronic component-mounted substrate | |
| JP3103597U (en) | Metal-coated fiber cloth for electromagnetic wave shielding | |
| WO2020111210A1 (en) | Conductive nonwoven fabric | |
| Esen et al. | Investigation of electromagnetic and ultraviolet properties of nano-metal-coated textile surfaces | |
| CN213951063U (en) | Noise-suppressing graphite articles and assemblies | |
| EP0877394B1 (en) | Composite magnetic tape | |
| KR20180068312A (en) | Flexible EMI shielding material and manufacturing method thereof | |
| US20190381763A1 (en) | Graphite composite film and method for producing same | |
| JP2008130630A (en) | Electromagnetic wave shielding sheet | |
| JP2020025093A (en) | Radio wave absorption sheet | |
| CN105025694A (en) | Electromagnetic wave absorbing material with protective layer and manufacturing method of electromagnetic wave absorbing material | |
| Jayasree et al. | Analysis of shielding effectiveness of single, double and laminated shields for oblique incidence of EM waves | |
| CN104332220B (en) | A kind of flexibility anti-nuclear electromagnetic pulse wisdom information system cable | |
| KR101906981B1 (en) | Near-field noise suppression film | |
| JP2019075375A (en) | cable | |
| JP2006245452A (en) | Electromagnetic wave shield material | |
| KR102227015B1 (en) | EMI shielding-Heat radiation composite sheet and manufacturing method thereof | |
| KR20160013602A (en) | Hybrid sheet for digitizer, method of manufacturing the same and apparatus having the same | |
| CN207409638U (en) | A kind of aerospace lightweight radio frequency coaxial-cable | |
| JP6562834B2 (en) | Electromagnetic wave shielding material and method for producing electromagnetic wave shielding material | |
| JPWO2013024758A1 (en) | Electromagnetic wave absorber | |
| JP2015088658A (en) | Sheet-like electromagnetic wave shield material | |
| JP2020013848A (en) | Electromagnetic wave absorbing adhesive sheet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20220419 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20230317 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20230509 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20230630 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20231010 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20240409 |