JPH048224B2 - - Google Patents
Info
- Publication number
- JPH048224B2 JPH048224B2 JP58233440A JP23344083A JPH048224B2 JP H048224 B2 JPH048224 B2 JP H048224B2 JP 58233440 A JP58233440 A JP 58233440A JP 23344083 A JP23344083 A JP 23344083A JP H048224 B2 JPH048224 B2 JP H048224B2
- Authority
- JP
- Japan
- Prior art keywords
- conductive
- thermoplastic resin
- sheet
- electromagnetic wave
- plastic
- 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.)
- Expired - Lifetime
Links
- 229920005992 thermoplastic resin Polymers 0.000 claims description 28
- 239000002131 composite material Substances 0.000 claims description 12
- 239000011231 conductive filler Substances 0.000 claims description 11
- 239000002985 plastic film Substances 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 8
- 229920005989 resin Polymers 0.000 description 21
- 239000011347 resin Substances 0.000 description 21
- 230000000694 effects Effects 0.000 description 18
- 229920003023 plastic Polymers 0.000 description 16
- 239000004033 plastic Substances 0.000 description 16
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 14
- 239000010410 layer Substances 0.000 description 10
- 238000000034 method Methods 0.000 description 10
- 239000004793 Polystyrene Substances 0.000 description 7
- 239000002184 metal Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 238000000465 moulding Methods 0.000 description 6
- 229920002223 polystyrene Polymers 0.000 description 6
- XECAHXYUAAWDEL-UHFFFAOYSA-N acrylonitrile butadiene styrene Chemical compound C=CC=C.C=CC#N.C=CC1=CC=CC=C1 XECAHXYUAAWDEL-UHFFFAOYSA-N 0.000 description 5
- 239000002356 single layer Substances 0.000 description 5
- 229920000049 Carbon (fiber) Polymers 0.000 description 4
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 4
- 239000004917 carbon fiber Substances 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 239000006229 carbon black Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229920005604 random copolymer Polymers 0.000 description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000004040 coloring Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000003063 flame retardant Substances 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000007733 ion plating Methods 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 238000011282 treatment Methods 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 1
- 229920002972 Acrylic fiber Polymers 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 239000004605 External Lubricant Substances 0.000 description 1
- 239000004610 Internal Lubricant Substances 0.000 description 1
- 239000006057 Non-nutritive feed additive Substances 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004512 die casting Methods 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- VXNZUUAINFGPBY-UHFFFAOYSA-N ethyl ethylene Natural products CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 229920006244 ethylene-ethyl acrylate Polymers 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920005668 polycarbonate resin Polymers 0.000 description 1
- 239000004431 polycarbonate resin Substances 0.000 description 1
- 229920005990 polystyrene resin Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 239000011802 pulverized particle Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
- 238000007666 vacuum forming Methods 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
- 210000002268 wool Anatomy 0.000 description 1
Description
本発明は、熱可塑性樹脂シートと導電性熱可塑
性樹脂シートの複合シートで、しかも賦形性、着
色性、電磁波遮蔽性にすぐれた電磁波遮蔽性複合
プラスチツクシートに関する。
従来、事務機器、電子計算機、TVレシーバ
ー、などの電子機器は、それ自体が電磁波の発生
源となり得るものであり、また、周囲の電気機器
によつても影響を受け、誤動作やノイズの原因と
なつている。
さらに、電子機器の筐体には、板金やアルミダ
イキヤストなどが使用されていたが、この場合
は、電磁波による障害はある程度防止できた。
しかしながら近年、成形の容易さ、耐蝕性自由
なデザイン、外観の良さ、軽さ、生産コストの低
減などのメリツトにより、プラスチツク材料が電
子機器の筐体に使用される例が増加している。
プラスチツク材料は一般に電気絶縁性が高く、
電磁波に対して透明である為に、そのままでは遮
蔽効果が期待できないので、電子機器の筐体にプ
ラスチツク材料を用いる場合は、遮蔽処理が必要
となる。
特に最近では、電子機器からの電磁波の放射に
対して、厳しく制限が加えられて居り、遮蔽処理
に対する要求が高まつている。
プラスチツクに電磁波遮蔽効果を付与する方法
として、従来よりアルミ箔や導電テープの貼り
合せ、亜鉛熔射、導電性塗料、プラスチツ
クメツキ、真空蒸着、スパツタリング、イ
オンプレーテイング、導電性フイラー混入プラ
スチツクコンパウンドなど数多くの方法が検討さ
れている。
まず、
(1) アルミ箔や導電テープの貼り合せによる電磁
波遮蔽効果の付与は、作業に熟練を要する上に
複雑な形状に適さないなどの欠点を有する。
(2) 亜鉛熔射や導電性塗料の塗工は現在最も一般
的に用いられる方法であるが、複雑な形状では
膜厚が不均一になる上に、密着性が不充分で、
導電層の剥落により、火災の危険があるとされ
る。
(3) プラスチツクメツキは、耐久性、密着性が良
好であるが、ベースとなるプラスチツクに制限
がある。さらに、大型品に不向きなどの欠点を
有する。
(4) 真空蒸着、スパツタリング、イオンプレーテ
イングなどは蒸着技術の応用で、良好な電磁波
遮蔽効果が得られるが、装置が高価である上
に、高度な技術が必要であるので、コマーシヤ
ルベースでは殆んど行なわれていない。
以上に述べて来た様な、プラスチツク成形品
の表面に導電層を形成し、電磁波遮蔽効果を付
与する手法に対して、
(5) 導電性フイラーをプラスチツク中に分散複合
化した導電性プラスチツクの成形品は、導電層
の剥落による電磁波遮蔽効果の低下や、火災の
危険の心配はない。
しかしながら、この様な導電性プラスチツク成
形品は、導電性フイラーを多量に加えなければ、
電磁波の遮蔽効果が上がらず、添加量を増加する
とベースになるプラスチツクの力学物性を損なつ
たり、不良な外観となり、更にコスト的にも非常
に高価なものとなる、といつた欠点を有してい
た。
通常、射出成形品は生産性にすぐれ、安価に量
産されるため、多くの製品が開発されている。し
かし、成形品が大型化され、しかも重量軽減にと
もなう肉薄のものになると、歪、曲がり及びヒケ
等の不良現象を招く欠点がある。この欠点を解決
すべく、成形品の肉厚を厚くし、成形品の前記不
良現象を取り除く低発泡成形品が開発されている
が、この成形品は、外観が悪くかつ成形時間が長
くかかる問題点がある。また、電磁波遮蔽効果を
上げるための導電材料を含有する熱可塑性樹脂
も、前記の様な射出成形品では、物性不足、外観
不良及び着色性不良等欠点があつた。
また、一方、導電性フイラーを混入した熱可塑
性樹脂を単層シート、あるいは、導電性熱可塑性
樹脂シートの両面に、熱可塑性樹脂を共押出し法
により一体に積層した電磁波遮蔽性プラスチツク
シートがある。
まず、電磁波遮蔽性単層シートの場合は、導電
層の剥落はないが、力学物性、外観が低下する。
次に、外観及び力学物性を改良した、前記した
積層電磁波遮蔽性プラスチツクシートがあるが、
電磁波遮蔽効果を得る為に必要なアースが、とり
づらいという欠点がある。
本発明は、かかる欠点を解決したものであり、
熱可塑性樹脂シート基材の片面に導電性フイラー
を１〜40容量％を含有させた導電性熱可塑性樹脂
シートを熱可塑性樹脂シート基材の厚み１に対し
て0.1〜3.0の割合で、一体化することにより、導
電層で電磁波遮蔽性をもたせかつアースも簡単に
とることができ、また絶縁層により外観、着色性
及び補強効果をもたせる事により優れた電磁波遮
蔽性、良好な外観、着色性及び補強効果を有する
事を特徴とする複合プラスチツクシートを提供せ
んとするものである。
すなわち、本発明は、(A) 熱可塑性樹脂シート
基材、(B) １〜40容量％の導電フイラーを含有す
る導電性熱可塑性樹脂シートとの複合シートであ
り、かつ(A)と(B)との厚さ比率が１：0.1〜3.0から
なることを特徴とする。
本発明に用いられる導電性熱可塑性樹脂のベー
スとなる樹脂としては、硬質塩化ビニル樹脂、ア
クリル変性硬質塩化ビニル樹脂、耐衝撃スチレン
樹脂、ABS樹脂、エチレン樹脂、プロピレン樹
脂、ポリカーボネート樹脂、スチレン変性PPO
樹脂及びポリアミド樹脂が用いられ、これらにス
チレン樹脂、エチレン−酢酸ビニル共重合樹脂、
エチレン−エチルアクリレート共重合樹脂、エチ
レン−１−ブテンランダム共重合樹脂、ブタジエ
ンが20〜80重量％であるスチレン−ブタジエンブ
ロツク共重合体を混合することができる。
更に、本発明の導電性熱可塑性樹脂の性能を改
良する為に、酸化防止剤、安定剤、内部滑剤、外
部滑剤、可塑剤、難燃剤、難燃助剤などの加工助
剤を添加する事もできる。
次に、本発明に用いられる、導電性フイラーと
しては、カーボンブラツク、グラフアイト、金属
化ガラス繊維、金属繊維、金属フレーク、金属リ
ボン、金属ウール、金属粉、カーボン繊維、金属
化カーボン繊維、銅グラフト、Niコートグラフ
アイト、Niコートマイカアクリル繊維の内の一
種又は２種以上が用いられる。
導電性フイラーの添加量は、１〜40容量％、好
ましくは10〜30容量％であり、１容量％未満では
電磁波遮蔽効果が殆んど得られず、40容量％を超
えると押出成形が困難となり、力学的物性も劣る
ものとなる。
また、本発明の表面層、すなわち、絶縁層に用
いられる熱可塑性樹脂は、成形品の密着性の問題
から、前記導電性熱可塑性樹脂と同様なものが好
ましく、異種の樹脂を使用する場合は、接着に富
んだ樹脂を混合する必要がある。
また、導電性熱可塑性樹脂シート厚みは、熱可
塑性樹脂シート基材の厚み１に対して0.1〜3.0の
割合がよく、好ましくは0.5〜1.5の割合がよい。
熱可塑性樹脂シート厚み１に対して導電性熱可塑
性樹脂シート0.1未満では、押出し、製膜するの
が困難となり、しかも、電磁波遮蔽効果がほとん
ど得られなくなる。また、3.0を超えると差圧成
形及び機械的強度等の特性が低下する。
さらに、この様にして得られる本発明の電磁波
遮蔽性複合プラスチツクシートの全体の肉厚は、
0.5mm〜6.0mm好ましくは1.0mm〜4.0mm程度であり、
肉厚が0.5mm未満では、圧空又は真空成形した場
合に、成形品自体の強度が不足し、6.0mmを超え
ると、成形時間が長くかかり、偏肉が大きくなつ
て成形が困難となる。
次に、本発明の複合プラスチツクシートを製造
するには、熱可塑性樹脂と導電性フイラーをバン
バリーミキサー、加圧ニーダー、コニーダー、押
出機等の混練機、押出機にて混合、ペレツト化す
る。そして、得られたペレツトを一方の押出機に
供給し、他方の押出機に熱可塑性樹脂を供給して
ダイより共押出し一体化あるいは、熱可塑性樹脂
シートに、導電性熱可塑性樹脂を押出しコーテイ
ングして、電磁波遮蔽性プラスチツク複合プラス
チツクシートを得ることができる。
以上説明したとおり、本発明は、熱可塑性樹脂
シートと導電性熱可塑性樹脂シートとの複合プラ
スチツクシートとすることにより、外観、着色性
及び力学的物性が良好にして、しかも電磁波遮蔽
性にすぐれた効果を有するものである。
以下本発明を実施例により更に詳細に説明す
る。
実施例 １〜３
耐衝撃性スチレン樹脂（電気化学工業(株)製、商
品名デンカスチロールHI−Ｓ−３）、エチレン−
１−ブテンランダム共重合樹脂（三井石油化学工
業(株)製、商品名タフマ−Ａ−4085）、カーボンブ
ラツク（キヤボツト社製、商品名バルカンXC−
72）及びカーボンフアイバー（東邦レーヨン(株)製
商品名ベスフアイトHTA−C6S）を表に示す組
成で配合し、2.5バンバリーミキサーで混練し
た後、紛砕機で粉砕粒とした（導電性ポリスチレ
ン）。
次に、導電性ポリスチレンを40mmφの押出機
（Ｌ／Ｄ＝24）の供給口に供給し、溶融して一方
に、耐衝撃性スチレン樹脂（電気化学工業(株)製、
商品名デンカスチロールHI−Ｓ−３）を50mmφ
の押出機（Ｌ／Ｄ＝25）の供給口より供給し、溶
融して前記導電性ポリスチレンと共押出して、表
に示すような二層シートを得た。この電磁遮蔽性
複合プラスチツクシートの物性は、表に示す通
り、電磁波遮蔽効果、力学物性及び外観共すぐれ
ていた。
実施例 ４〜６
耐衝撃性スチレン樹脂の代わりにアクリロニト
リル−スチレン−ブタジエン共重合樹脂（電気化
学工業(株)商品名デンカABS GR−2000）を用い
た以外は、全て実施例１と同様の操作を行ない、
表に示すような厚みの二層シートを得た。この電
磁波遮蔽効果、力学物性及び外観共すぐれてい
た。
実施例 ７
実施例１の組成で、40ｍ／ｍφ押出機により耐
衝撃性ポリスチレン樹脂を用いて、厚さ１mmのポ
リスチレン単層シートを押出した。そのポリスチ
レン単層の片面に、実施例１と同様な方法で得た
導電性熱可塑性樹脂の粉砕粒を40ｍ／ｍφ押出機
の供給口に供給し、前記得られたポリスチレン単
層シートの片面にコーテイングをして、全体厚み
2.0mmの電磁波遮蔽性複合プラスチツクシートを
得た。この電磁波遮蔽効果、力学物性及び外観共
すぐれていた。
比較例 １〜２
導電性フイラーの添加量が、特許請求の範囲以
外とした事以外は、実施例１と同様の操作を行つ
た。電磁波遮蔽効果、力学的物性、外観のいずれ
かが劣つていた。
比較例 ３〜４
電磁波遮蔽層の厚みが特許請求の範囲以外とし
た事以外は、実施例１と同様の操作を行つた。電
磁波遮蔽効果、力学的物性、外観のいずれかが劣
つていた。
The present invention relates to an electromagnetic wave-shielding composite plastic sheet that is a composite sheet of a thermoplastic resin sheet and a conductive thermoplastic resin sheet, and has excellent shapeability, colorability, and electromagnetic wave-shielding properties. Conventionally, electronic devices such as office equipment, computers, and TV receivers can themselves be sources of electromagnetic waves, and are also affected by surrounding electrical devices, which can cause malfunctions and noise. It's summery. Furthermore, the housings of electronic devices used to be made of sheet metal, aluminum die-casting, etc., which could prevent electromagnetic interference to some extent. However, in recent years, plastic materials have been increasingly used for the housings of electronic devices due to their advantages such as ease of molding, corrosion resistance, free design, good appearance, light weight, and reduced production costs. Plastic materials generally have high electrical insulation properties;
Since it is transparent to electromagnetic waves, it cannot be expected to have a shielding effect as it is, so if plastic material is used for the housing of electronic equipment, shielding treatment is required. Particularly recently, strict restrictions have been placed on the radiation of electromagnetic waves from electronic devices, and there has been an increasing demand for shielding treatments. There are many conventional methods for imparting electromagnetic shielding effects to plastics, such as laminating aluminum foil or conductive tape, zinc spraying, conductive paint, plastic plating, vacuum deposition, sputtering, ion plating, and plastic compounds mixed with conductive fillers. methods are being considered. First, (1) Providing an electromagnetic wave shielding effect by laminating aluminum foil or conductive tape has drawbacks such as requiring skill and being unsuitable for complex shapes. (2) Zinc spraying and coating with conductive paint are currently the most commonly used methods, but with complex shapes, the film thickness becomes uneven and adhesion is insufficient.
There is a risk of fire due to the conductive layer peeling off. (3) Plastic plating has good durability and adhesion, but there are limitations to the base plastic. Furthermore, it has drawbacks such as being unsuitable for large items. (4) Vacuum evaporation, sputtering, ion plating, etc. are applications of evaporation technology that can provide good electromagnetic shielding effects, but the equipment is expensive and advanced technology is required, so they are not used on a commercial basis. Almost never done. In contrast to the above-mentioned method of forming a conductive layer on the surface of a plastic molded product to impart an electromagnetic wave shielding effect, (5) a method of forming a conductive plastic in which a conductive filler is dispersed and composited in the plastic is proposed. With molded products, there is no need to worry about deterioration of electromagnetic shielding effectiveness due to peeling of the conductive layer or risk of fire. However, such conductive plastic molded products cannot be manufactured without adding a large amount of conductive filler.
It has the disadvantages that it does not improve the electromagnetic wave shielding effect, and if the amount added is increased, it impairs the mechanical properties of the base plastic, gives a poor appearance, and becomes extremely expensive. was. Generally, injection molded products have excellent productivity and can be mass-produced at low cost, so many products have been developed. However, as molded products become larger and thinner due to weight reduction, they have the disadvantage of causing defects such as distortion, bending, and sink marks. In order to solve this drawback, a low-foam molded product has been developed that increases the wall thickness of the molded product and eliminates the defective phenomenon of the molded product, but this molded product has problems such as poor appearance and long molding time. There is a point. In addition, thermoplastic resins containing conductive materials to enhance the electromagnetic wave shielding effect also have drawbacks such as insufficient physical properties, poor appearance, and poor colorability in injection molded products as described above. On the other hand, there are electromagnetic wave-shielding plastic sheets in which a thermoplastic resin mixed with a conductive filler is laminated as a single layer, or a thermoplastic resin is integrally laminated on both sides of a conductive thermoplastic resin sheet by a coextrusion method. First, in the case of an electromagnetic wave shielding single-layer sheet, the conductive layer does not peel off, but the mechanical properties and appearance deteriorate. Next, there is the above-mentioned laminated electromagnetic wave shielding plastic sheet with improved appearance and mechanical properties.
The drawback is that it is difficult to provide the grounding needed to obtain the electromagnetic shielding effect. The present invention solves these drawbacks,
A conductive thermoplastic resin sheet containing 1 to 40% by volume of conductive filler is integrated on one side of a thermoplastic resin sheet base material at a ratio of 0.1 to 3.0 to 1 thickness of the thermoplastic resin sheet base material. By doing so, the conductive layer provides electromagnetic wave shielding properties and can be easily grounded, and the insulating layer provides appearance, coloring properties, and reinforcing effects, resulting in excellent electromagnetic shielding properties, good appearance, coloring properties, and It is an object of the present invention to provide a composite plastic sheet characterized by having a reinforcing effect. That is, the present invention is a composite sheet of (A) a thermoplastic resin sheet base material, (B) a conductive thermoplastic resin sheet containing 1 to 40% by volume of a conductive filler, and (A) and (B). ) is characterized by a thickness ratio of 1:0.1 to 3.0. The base resins for the conductive thermoplastic resin used in the present invention include hard vinyl chloride resin, acrylic modified hard vinyl chloride resin, impact-resistant styrene resin, ABS resin, ethylene resin, propylene resin, polycarbonate resin, and styrene-modified PPO.
Resins and polyamide resins are used, and these include styrene resins, ethylene-vinyl acetate copolymer resins,
Ethylene-ethyl acrylate copolymer resin, ethylene-1-butene random copolymer resin, and styrene-butadiene block copolymer containing 20 to 80% by weight of butadiene can be mixed. Furthermore, in order to improve the performance of the conductive thermoplastic resin of the present invention, processing aids such as antioxidants, stabilizers, internal lubricants, external lubricants, plasticizers, flame retardants, and flame retardant aids may be added. You can also do it. Next, examples of the conductive filler used in the present invention include carbon black, graphite, metallized glass fiber, metal fiber, metal flake, metal ribbon, metal wool, metal powder, carbon fiber, metallized carbon fiber, copper One or more of graft, Ni-coated graphite, and Ni-coated mica acrylic fibers are used. The amount of conductive filler added is 1 to 40% by volume, preferably 10 to 30% by volume. If it is less than 1% by volume, almost no electromagnetic wave shielding effect can be obtained, and if it exceeds 40% by volume, extrusion molding is difficult. Therefore, the mechanical properties are also inferior. Further, the thermoplastic resin used for the surface layer of the present invention, that is, the insulating layer, is preferably the same as the above-mentioned conductive thermoplastic resin from the viewpoint of adhesion of the molded product.If a different type of resin is used, , it is necessary to mix a resin rich in adhesion. Further, the thickness of the conductive thermoplastic resin sheet has a good ratio of 0.1 to 3.0, preferably 0.5 to 1.5, with respect to the thickness 1 of the thermoplastic resin sheet base material.
If the thickness of the conductive thermoplastic resin sheet is less than 0.1 to 1 of the thickness of the thermoplastic resin sheet, it will be difficult to extrude and form a film, and moreover, the electromagnetic wave shielding effect will hardly be obtained. Moreover, if it exceeds 3.0, properties such as differential pressure molding and mechanical strength will deteriorate. Furthermore, the total thickness of the electromagnetic wave shielding composite plastic sheet of the present invention obtained in this manner is as follows:
0.5mm to 6.0mm, preferably about 1.0mm to 4.0mm,
If the wall thickness is less than 0.5 mm, the strength of the molded product itself will be insufficient when air pressure or vacuum forming is performed, and if it exceeds 6.0 mm, the molding time will be long and the uneven thickness will become large, making molding difficult. Next, to produce the composite plastic sheet of the present invention, the thermoplastic resin and the conductive filler are mixed and pelletized using a kneader or extruder such as a Banbury mixer, pressure kneader, co-kneader, or extruder. Then, the obtained pellets are fed to one extruder, and the thermoplastic resin is fed to the other extruder, and the pellets are coextruded from a die and integrated, or the thermoplastic resin sheet is extruded and coated with a conductive thermoplastic resin. Thus, an electromagnetic wave shielding plastic composite plastic sheet can be obtained. As explained above, the present invention provides a composite plastic sheet made of a thermoplastic resin sheet and a conductive thermoplastic resin sheet, which has good appearance, colorability, and mechanical properties, and has excellent electromagnetic wave shielding properties. It is effective. The present invention will be explained in more detail below with reference to Examples. Examples 1 to 3 Impact-resistant styrene resin (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name Denka Styrol HI-S-3), ethylene-
1-Butene random copolymer resin (manufactured by Mitsui Petrochemical Industries, Ltd., trade name: TAFMER-A-4085), carbon black (manufactured by CABOT Co., Ltd., trade name: Vulcan XC-)
72) and carbon fiber (product name Besphite HTA-C6S, manufactured by Toho Rayon Co., Ltd.) were blended in the composition shown in the table, kneaded with a 2.5 Banbury mixer, and then made into pulverized particles with a pulverizer (conductive polystyrene). Next, conductive polystyrene was supplied to the supply port of a 40 mmφ extruder (L/D = 24), melted, and on the other hand, impact-resistant styrene resin (manufactured by Denki Kagaku Kogyo Co., Ltd.),
Product name Denka Styrol HI-S-3) 50mmφ
The mixture was supplied from the feed port of an extruder (L/D=25), melted, and coextruded with the conductive polystyrene to obtain a two-layer sheet as shown in the table. As shown in the table, the physical properties of this electromagnetic shielding composite plastic sheet were excellent in terms of electromagnetic shielding effect, mechanical properties, and appearance. Examples 4 to 6 All operations were the same as in Example 1, except that acrylonitrile-styrene-butadiene copolymer resin (Denka Kagaku Kogyo Co., Ltd., trade name Denka ABS GR-2000) was used instead of the impact-resistant styrene resin. do the
A two-layer sheet having the thickness shown in the table was obtained. This electromagnetic wave shielding effect, mechanical properties, and appearance were excellent. Example 7 A single-layer polystyrene sheet having the composition of Example 1 and having a thickness of 1 mm was extruded using an impact-resistant polystyrene resin using a 40 m/mφ extruder. On one side of the polystyrene single layer sheet, pulverized conductive thermoplastic resin particles obtained in the same manner as in Example 1 were supplied to the supply port of a 40 m/mφ extruder, and on one side of the polystyrene single layer sheet obtained above, Coating, overall thickness
A 2.0 mm electromagnetic wave shielding composite plastic sheet was obtained. This electromagnetic wave shielding effect, mechanical properties, and appearance were excellent. Comparative Examples 1-2 The same operation as in Example 1 was performed except that the amount of conductive filler added was outside the claimed range. It was inferior in electromagnetic shielding effect, mechanical properties, or appearance. Comparative Examples 3 to 4 The same operations as in Example 1 were performed except that the thickness of the electromagnetic wave shielding layer was outside the claimed range. It was inferior in electromagnetic shielding effect, mechanical properties, or appearance.
【表】
表中の略語は、次の通りである。
(1) HI−PS：耐衝撃スチレン樹脂、「電気化学
工業(株)製、商品名デンカスチロール、HI−Ｓ
−３」
(2) ABS：アクリロニトリル−スチレン−ブタ
ジエン共重合樹脂「電気化学工業(株)製、商品名
デンカABS、GR−2000」
(3) タフマー：エチレン−１−ブテンランダム共
重合樹脂、「三井石油化学工業(株)製、商品名、
タフマーＡ−4085」
(4) カーボンブラツク：キヤボツト社製、商品
名、バルカンXC−72
(5) カーボンフアイバー：東邦レーヨン(株)製、商
品名、ベスフアイトHTA−C6S
実施例及び比較例に示す成形品物性は、下記の
方式により測定を行なつた。
(1) 電磁波遮蔽効果：デカン法により、図面に示
す電磁波遮蔽効果測定装置を使用し、トラツキ
ングジエネレータにて励起した高周波電圧を発
信アンテナに印加し、試料を介して受信した受
信電圧と発信電圧との比をスペクトラムアナラ
イザーにて測定した。
(2) 引張強度：JIS Ｋ−6871準拠法
(3) 曲げ弾性率：ASTM Ｄ−790準拠法
(4) アイゾツト衝撃強度：JIS Ｋ−6871準拠法[Table] The abbreviations in the table are as follows. (1) HI-PS: Impact-resistant styrene resin, “manufactured by Denki Kagaku Kogyo Co., Ltd., trade name Dencastyrol, HI-S”
-3" (2) ABS: Acrylonitrile-styrene-butadiene copolymer resin "manufactured by Denki Kagaku Kogyo Co., Ltd., trade name Denka ABS, GR-2000" (3) Tafmer: Ethylene-1-butene random copolymer resin, " Manufactured by Mitsui Petrochemical Industries, Ltd., product name,
"Tafmar A-4085" (4) Carbon black: manufactured by Kayabot Co., Ltd., trade name, Vulcan XC-72 (5) Carbon fiber: manufactured by Toho Rayon Co., Ltd., trade name, Besphite HTA-C6S Molding shown in Examples and Comparative Examples Product properties were measured using the following method. (1) Electromagnetic shielding effect: Using the Deccan method and using the electromagnetic shielding effect measurement device shown in the drawing, a high-frequency voltage excited by a tracking generator is applied to the transmitting antenna, and the received voltage received through the sample and the transmitter are measured. The ratio to the voltage was measured using a spectrum analyzer. (2) Tensile strength: JIS K-6871 compliant method (3) Flexural modulus: ASTM D-790 compliant method (4) Izot impact strength: JIS K-6871 compliant method
図面は、本発明のプラスチツク成形体の電磁波
遮蔽効果の測定装置の概略図である。
符号、１……シールドボツクス、２……プラス
チツク成形品、３……発信アンテナ、４……受信
アンテナ、５……スペクトラムアナライザー、６
……トラツキングジエネレーター。
The drawing is a schematic diagram of an apparatus for measuring the electromagnetic wave shielding effect of a plastic molded body according to the present invention. Code, 1... Shield box, 2... Plastic molded product, 3... Transmitting antenna, 4... Receiving antenna, 5... Spectrum analyzer, 6
...Tracking Generator.
Claims (1)
量％の導電フイラーを含有する導電性熱可塑性樹
脂シートとの複合シートであり、かつ(A)と(B)との
厚さ比率が１：0.1〜3.0からなる電磁波遮蔽性複
合プラスチツクシート。1. A composite sheet of (A), a thermoplastic resin sheet base material, and (B), a conductive thermoplastic resin sheet containing 1 to 40% by volume of a conductive filler, and (A) and (B). Electromagnetic wave shielding composite plastic sheet with a thickness ratio of 1:0.1 to 3.0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58233440A JPS60125656A (en) | 1983-12-10 | 1983-12-10 | Electromagnetic wave shielding composite plastic sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58233440A JPS60125656A (en) | 1983-12-10 | 1983-12-10 | Electromagnetic wave shielding composite plastic sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60125656A JPS60125656A (en) | 1985-07-04 |
| JPH048224B2 true JPH048224B2 (en) | 1992-02-14 |
Family
ID=16955073
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58233440A Granted JPS60125656A (en) | 1983-12-10 | 1983-12-10 | Electromagnetic wave shielding composite plastic sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60125656A (en) |
-
1983
- 1983-12-10 JP JP58233440A patent/JPS60125656A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60125656A (en) | 1985-07-04 |
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