JP4571318B2 - Conductive network - Google Patents
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- JP4571318B2 JP4571318B2 JP2001014083A JP2001014083A JP4571318B2 JP 4571318 B2 JP4571318 B2 JP 4571318B2 JP 2001014083 A JP2001014083 A JP 2001014083A JP 2001014083 A JP2001014083 A JP 2001014083A JP 4571318 B2 JP4571318 B2 JP 4571318B2
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Description
【0001】
【発明の属する技術分野】
本発明は、導電性を有した網状体に関する。さらに詳しくは、廃棄物処分場からの有害物質の地下水汚染防止を目的として、廃棄物処分場の底面に遮水シートが設置されているが、当該遮水シートの破損により有害物質の散逸を防止するため、遮水シート/中間層/遮水シートの構成の遮水構造体を用いたダブルライナー工法があり、該中間層に不織布/平面導電体/不織布として電気的に漏水を検知するものと、立体網状体として通気性もしくは圧力検知によって漏水を検知し、その部分へベントナイトなどの止水材を注入して、遮水効果を修復する2つのダブルライナー工法があり、後者も立体網状体に電気的漏水検知機能を付与することが求められており、本発明の導電性網状体は、かかる電気的検知法に好適に用い得る網状体に関するものである。
【0002】
【従来の技術】
廃棄物処分場からの有害物質の地下水汚染防止のため、廃棄物処分場の底面は遮水構造体で形成され、その上部に廃棄物層から逸流する汚水を集め排水する面状排水材が使用されている。該面状排水材には、特公昭58−9186号公報や特開平11−247060号公報開示されているフィラメントが融着接着して一体化し、かつ全体的に凹凸状になって一定の厚みを持ったマツト状の立体網状体が使用されている。
【0003】
また、上記廃棄物処分場の遮水構造体として、セメント打ちなどの剛性工法に比べ、ゴムシートやプラスチックシートを止水材として用いるのが、簡単であり、従来から行なわれてきたが、前記剛性工法に比べ、シート類は施工時や埋め立て時に重機で破損する可能性が高く、破損すると、漏水する問題があり、これらを改良する試みがなされ、上下に止水シート材を配置し中層に、圧力や通気性などの流体検知法による漏水検知する手法の、立体網状体や凹凸フィルムなどの多孔性体や、漏水の電気的検知法による平面導電体を配するダブルライナー工法が一般的に施工されている。
【0004】
電気的検知法による平面導電体は、漏水の検知が簡易であるが、漏水箇所の検知の後の修復に難があり、多孔性体との併用の方向が望ましいとされている。この漏水検知には、検知材として導電性繊維を混綿した導電性不織布や不織布とアルミニウムホイルなどの金属箔を一体化した導電性不織布を止水シート材に挟んだ遮水構造体とし廃棄物処分場の埋め立て部分の地表に、一方の電極を、もう一方の電極を遮水シートに挟まれた導電性不織布として、該止水シートが破損し、導電性不織布に漏水した場合、両電極間が繋がり、漏水を検知するものであり、導電性不織布を区切ることで漏水箇所ゾーンを特定したり、漏水規模を、該導電性不織布の電気抵抗で検知する応用も考えられる。
【0005】
【発明が解決しょうとする課題】
本発明者らは、前記したダブルライナー工法において、もっぱら漏水箇所の復旧機能に焦点を当てた止水シート材に挟まれる多孔性体である立体網状体の発明に注力し、特公昭58−9186号公報や特開平11−247060号公報開示されているフィラメントが融着接着して一体化し、かつ全体的に凹凸状になって一定の厚みを持ったマツト状になった立体網状体、また、最近、本発明者らが開発したより軽量で空隙率が高く従来の排水材より圧縮応力が大きいプリーツ形状の立体網状体は、軽量でも厚み方向への剛直性と耐圧性の向上できたが、漏水の検知機能は配慮されておらず、何らかの検知機能を別途設けなければならない問題があった。
【0006】
本発明の目的は、まず第一に、多孔性の網状体に導電性を持たせ、簡易に漏水検知ができる上記廃棄物処分場の遮水構造体の構成平面素材を提供することであり、第二の目的は、土圧が掛かって常に厚味方向に圧縮応力が掛かる用途で、従来の排水材より圧縮応力が大きくて、高加重下でも厚みの減少量が少なく高い空隙率を保持できる立体網状体に、前記遮水構造体として用いた時、漏水検知機能を与え、漏水箇所の遮水復旧と漏水検知機能をダブルライナー工法の遮水構造体に持たせ、より安全な廃棄物処分場を提供することにある。
【0007】
なお、前記した導電性不織布は、炭素繊維や金属繊維などの導電性繊維を使用している場合は、混綿して不織布化する手法で作成されるため、不織布として導電性を確保するには、該繊維同士が接触して、不織布全体として導電性繊維の網目を構成する都合上、該導電性繊維を少なくとも10〜20重量%混綿しないと導電性を確保できない問題がある。前記した導電性繊維は大半が剛直で、混綿に欠くことのできないカード掛けの大きな問題もあり、安価には導電性不織布を作れない大きな問題がある。また、導電素材としてアルミニウムホイルなどの金属箔を一体化して作った導電性不織布は、用いる用途が廃棄物処分場の遮水構造体であり、硫化水素などのガスでの腐食が避けられず、長期の導電性保持に問題がある。
【0008】
【課題を解決するための手段】
本発明は、平均粒子径が0.1〜5μmであるカーボンブラックを10〜40質量%含有する熱可塑性合成樹脂からなる、太さが0.1〜1.5mmの多数の導電性連続フィラメントが網状に重ね合わされ、その交差点で融着接着されて一体化しており、目付けが100g/m2 以上である、導電性を特徴とする網状体であって、当該カーボンブラックの添加によって、導電性連続フィラメントの表面電気抵抗が、1×105 Ω/cm以下となっている網状体である。
【0009】
さらには、さらに導電性が良い炭素繊維やステンレス繊維などの耐硫化水素性繊維の糸条が付加されて、導電性が強化されている網状体であり、具体的には、該網状体の連続フィラメントが未固化状態にある時に、上記糸条に圧着して、導電性網状体と一体化させて得ることができる。この場合は、導電性網状体の表面電気抵抗が、1×105 Ω/cmを若干超えても特に問題は無く、網状体全体として1×105 Ω/cm以下となっていれば良い。
【0010】
本発明は、耐圧性の良い導電性立体網状体であり、漏水箇所が検知された場所をその空隙に不透水材を注入して修復できる機能を持つ素材となすことであり、本発明の網状体を構成する導電性連続フィラメントを、凹凸が彫刻された金型上に流下させて、その交点を融着接着させながら、冷却固化させて、一体化と付型をさせた立体網状体としたものであり、さらには、産業廃棄物処分場の底面を構成する遮水構造体として用いるため、通常より耐圧性が求められているため、その使用する金型を断面が三角の頂点をわずか切断除去した様な、台形のブロックが平面上に配置されており、該台形の上辺と底面がそれぞれ同一の平面上にある形状の金型を用いるのが都合良く、該金型でブロックが長さ方向に平行して密に設置されたものが最も都合が良く、この金型で作られた、厚み方向断面において、プリーツ状で長さ方向に整然と平行して配列している連続した複数の畦部と溝部とが、交互に形成されているプリーツ形状の立体網状体が最適である。
【0011】
なお、本発明の基本の網状体は、前記金型が平らなものを用い、好ましくは、平滑平ロールで該平らな金型に網状体を押しつけて、実質厚みが0.1〜4mmのシート状としたもので、スパンボンド不織布や不透水層としてのポリエチシートとの張り合わせには、該平滑平ロールにこれらを添わせて供給し、該平滑平ロールで圧着させると容易に一体化したものとできる。
【0012】
【発明の実施の形態】
本発明の実施の形態について実施例の図示に基づいて以下に説明する。図1に本発明の一実施形態であるシート状の網状体に、ポリエステルスパンボンド不織布を張り合わせた、不織布と複合された導電性網状体の製造装置の側面概略図を示す。図2は図5Cの凹凸が彫刻された金型を用いた、導電性立体網状体の製造装置の側面概略図を示す。
【0013】
本発明による導電性網状体の形態は、例えばシート形状の網状体の図3、立体網状体の図4で例示するものであり、共に、前者は図5Aのフラット形状の金型を、後者は図5Cに例示する凹凸が彫刻された金型を用いており、図2に基付いて説明すると、平均粒子径が0.1〜5μmであるカーボンブラックを10〜40質量%練り込んだ熱可塑性合成樹脂からなる、太さが0.1〜1.5mmの多数の連続フィラメント1を溶融紡糸の紡糸口金2より、三角柱を寝かした形状が刻まれている金型4上に吐出して、網状に重ねてその交点を溶融接着させ、さらに圧着ロール6に添わせて平面体を供給し、これらを金型の凸面上部に圧着ローラー6で押しつけて、金型の凸部上の融着接着した網状体で圧着、一体化させると共に、凸部上の融着接着した網状体をさらに圧着させて、立体網状体の整形と畦部上端の補強を行なって、プリーツ状の立体網状体として、該立体網状体の畦下部と溝上部に三角柱形状の大きな空隙を有するマット形状の立体網状体で、該網状体を構成している導電性の導電性連続フィラメントで電気的検出を可能としたものである。
【0014】
本発明の連続フィラメントに使用する素材は、ポリプロピレン、ポリエチレン、ポリエチレンテレフタレートなどのポリエステルおよびナイロン6などのポリアミドなどの熱可塑性樹脂で、柔軟性を強化するためこれらの共重合体はさらに好ましく、これらのポリマーブレンドしたものやポリマーアロイも好ましい。
【0015】
本発明の連続フィラメントは、上記素材が平均粒子径が0.1〜5μmであるカーボンブラックを10〜40質量%含有することで、導電性を持つことを特徴としており、含有結果として表面電気抵抗が、1×105 Ω/cm以下となっている。本発明に使用するカーボンブラックは、ワックスなどで表面処理されていないものが好ましく、マスターバッチを使用して作成する場合は、安価品を使用すると上記条件を満足することが多い。また、その粒子径は、0.1〜5μmの平均粒子径のものが好ましく、細かすぎると分散しすぎてカーボン粒子間の接触が悪くなり過剰に添加しないと導電性が確保しにくく、大きすぎても粒子の接触不良で同様な状態となるので、いずれも、少ない添加量で導電性を確保するためには好ましくない。カーボンブラックの添加量は、10〜40質量%が好ましく、15〜25質量%がより好ましい。10質量%未満では、極端に導電性が低下し、40質量%以上では、連続フィラメントの形成が困難となるし、強度の低下が著しく好ましくない。
【0016】
本発明の連続フィラメントの太さは、強度と剛性の面から0.1〜1.5mmが好ましく1.5mmより太いと、本発明の網状体を成形しにくく、0.1mmより細いと剛性に問題が出やすくなるため好ましくない。また本発明のシート状網状体の目付けは用途によるが、概ね100〜1000g/m2 であり、空隙を有する立体網状体は、用途によるが、概ね100〜3000g/m2 の範囲であり、耐圧性強化を意図する場合は、連続フィラメントの強度と本数の積による耐圧強度の問題があり、250〜1500g/m2 が好ましい。なお、本発明の目的の網状体は、導電性の確保をするため、フィラメントの太さを細くして、フィラメント密度を上げても、その目付けが100g/m2 を下回ると、繊維構成本数が不足して繊維の交点が不足し導電性の確保が困難となり好ましくない。
【0017】
本発明の導電性、および本発明に用いる非導電性の立体網状体の厚みは、耐圧性強化を意図するには、4〜50mmが好ましく、なお50mmを超えると、連続フィラメントが金型に接触して、冷やされて到達しにくくなって不揃いとなるし、融着接着不良で、事実上製造が困難であるので好ましくない。なお、本発明に用いる金型は、圧着ロール6を用いる都合上、金型上面と底面が平行で、金型の凸部上面はすべての凸部上面が同一平面にあることが好ましい。
【0018】
本発明に用いる導電性糸条は、耐薬品性に優れた炭素繊維、ステンレスなどの耐硫化水素性の通電性に優れた金属線や金属繊維、これら金属のメッキ繊維であって、マルチフィラメント、モノフィラメント、紡績糸やスプリットヤーンなど、通電性の糸条を言う。
【0019】
張りつける平面体は、ポリエチレンなどの遮水シートや、スパンボンドやニードルパンチ、スパンレースや含浸接着した不織布を言い、不織布の場合は、経済的に、20〜300g/m2 目付けのポリエチレンテレフタレートスパンボンド不織布が特に好ましい。また、厚み方向に凹凸の突起が多数形成されている熱可塑性フイルムを接着したものであってもよい。該フイルムとしては、市販されているものが適宜採用されるが、例えばタキロン社製の「ジオグリッド」が好適である。
【0020】
本発明の立体網状体は可撓性ネットで補強されているのも好ましく、該可撓性ネットは、網目が15〜50mm□の漁網などの編みたてネット、スプリットヤーンを使用する寒冷紗、マルチまたはモノフィラメントなどの糸条を縦と横方向に織ったり引き揃えたものやスクリムネットなどが都合良く用いられ、強度補強の点でポリエチレンテレフタレート製漁網が特に好ましい。
【0021】
(作用) 本発明の網状体は、通電性を生じるカーボンブラックが適当量添加され、少なくとも表面電気抵抗が、1×105 Ω/cmの通電性を保有しているため、廃棄物処分場の底面に、遮水シートに挟んで、ダブルライナー工法の遮水構造体とすると、当該遮水シートが破損して漏水した場合、電気的な検出によって、極めて容易に、漏水の可否、工夫によって漏水場所まで特定可能になり、都合良く用いることができる。また、本発明の網状体を立体網状体形状とするか、立体網状体と組み合わせることで、当該立体網状体が連続したフィラメントで構成されており、水などの液体は容易に網状体を通過さすことができ、廃棄物処分場の底面漏水検知と漏水補修に極めて利便性が良い。具体的には、導電性不織布を使用している物に比べ、遮水シート間の空隙を大きく確保できるため、ベントナイト懸濁液などの遮水性物質を漏水箇所に送り込んで漏水修復が容易にできる。さらには、金属箔を使用した導電性不織布を使用している物に比べ、本発明の網状体は、導電性素材としてカーボンブラックを用いているため耐腐食ガスによる影響を受けにくいことと、単に市場にある導電性体を使用しているため、大変経済的である。
【0022】
【実施例】
次に本発明の効果を実施例と比較例で具体的に説明する。
(実施例1〜3、比較例1〜2) 本発明の網状体は第1図に例示する装置に、図5Aのフラット金型4を用い、斜め上方から圧着ロール6に添わせて目付け80g/m2 のポリエチレンテレフタレート製スパンボンド不織布を供給する様セットし、融点が140℃でメルトフローレートが18g/10分のエチレンープロピレン共重合体に、平均粒子径が1μmであるカーボンブラック(大日本インキ社製PEONY BLACK F30940を使用)を表1の割合で練り込んだ樹脂の溶融物を、孔径1mm、5mmピッチで多数の紡糸ノズルが複数列列設された紡糸口金2より連続フィラメント1を紡出し、等速で移動しているフラット金型4に垂らし、網状に重ね、その交差点を融着接着させて網状物3を形成させ、該網状物が固化しない場所に設置した、圧着ロール6で、金型をベースとし、網状物を圧着成分として、不織布8を圧着して一体化させ図3に例示する実施例1〜3の導電性を特徴とする網状体を得た。同様にして比較例1〜2の網状体を得た。尚、表1におけるCBはカーボンブラックを示す。
【0023】
【表1】
【0024】
実施例1〜3の立体網状体は、何れも、長さ10mでも、通電できたが、比較例1〜2は通電できなかった。さらに、実施例1の立体網状体の上下を厚み1mmのポリエチレンシートで挟み、幅方向の側面を粘土で密封した後、僅かに折り曲げ、凹型とし、電気ごてで、5mmの穴を***部に開け、その上に、5cmの厚みで腐葉土を押し固めて乗せた、この腐葉土の穴の上の位置に、リード銅線を付けた釘を3cm打ち込み、立体網状体の導電性糸条に接続した銅線に乾電池を繋ぎ、それに、豆電球を繋ぎ、前記リード銅線も接続したが、豆電球は点かなかった。そこで、2Lの水を入れたポリエチレン袋を用意し、上記の穴の上の辺を目がけ、袋に穴を開けて散水した。しばらくすると、豆電球が点灯し、本発明の立体網状体が検知機能を持っていることを確認した。その後、側面の粘土を外して、立体網状体の状態を確認したところ、かなりの水の漏水が確認された。
【0025】
(実施例4〜5) 本発明の網状体は第1図に例示する装置に、図5Cに例示する凹凸が彫刻された金型4を用い、融点が140℃でメルトフローレートが18g/10分のエチレンープロピレン共重合体に、平均粒子径が1μmであるカーボンブラックを表1の割合で練り込んだ樹脂の溶融物を、孔径1mm、5mmピッチで多数の紡糸ノズルが複数列列設された紡糸口金2より連続フィラメント1を紡出し、等速で移動している三角柱が寝かされた形状が刻まれている金型4に垂らし、網状に重ね、その交差点を融着接着させて網状物を形成させ、該網状物が固化しない場所に設置した圧着ロール6で網状物7の凸部を圧迫して、より一体化させ、図4に例示する実施例4〜5の導電性を特徴とする立体網状体を得た。
【0026】
これらの導電性は実施例1と同様であり、実施例4を実施例1と同様にして、ポリエチレンシートで挟み、漏水テストを実施したところ、実施例1と同様の良い結果を得た。さらに、粘土で再び密閉し、上記のポリエチレンシートの穴の上の腐葉土の上に、鉄板で重しし、凹型となっているポリエチレンシートで挟まれた立体網状体の片方の端から水道水をホースで勢い良く注入すると、反対側の端からかなりの勢いで水がでてきたので、修復も可能と推定する。
【0027】
【発明の効果】
本発明の導電性網状体の一つは、立体網状体の断面が、三角形が横に繋がったプリーツ形状で、その一辺を立体網状体の上下面と仮想する、三角形状がしっかりと固定されて耐圧性を向上させたものであるが、該網状体の内部は網状物の壁で構成されており、該網状物は熱可塑性樹脂のフィラメントで構成されているため、嵩高で、通気性と通水性に優れており、空隙率が極めて大きいため軽量で、施工場所に運びかつ施工するに便利であり、従来のものより強度が向上しているため、従来品よりきつい使用条件に耐え得ることができるため、廃棄物処分場の遮水構造体である、ダブルライナー工法の立体網状体として最適であり、さらに、電気的漏水検知機能も付与されているため、本発明の網状体を用いると、より優れた遮水構造体とでき、廃棄物処分場の安全性の向上に寄与できる。またベントナイト懸濁液などの遮水性物質を漏水箇所に送り込んで漏水修復が容易にでき得るものとなる。また、本発明の導電性網状体は、熱可塑性樹脂から成る網状体であるため柔軟性に優れ、劣化もなく、且つ該樹脂中に導電性素材としてカーボンブラックを含有しているため、廃棄物処分場における耐腐食ガスによる影響を受けにくく、遮水シート材として信頼性の高いものとなり得る。
【図面の簡単な説明】
【図1】 本発明の導電性のシート状網状体の製造装置の概略図。
【図2】 本発明の導電性の立体網状体の製造装置の概略図。
【図3】 本発明のシート状網状体の一実施形態5を示す斜視図。
【図4】 本発明の立体網状体の一実施形態7を示す斜視図。
【図5】 金型の例 A:シート状網状体に使用するフラット金型
B:プリーツ断面の立体網状体に使用する例
C:フラット部を彫刻した金型A
D:従来の金型の例
【符号の説明】
1 連続フィラメント
2 紡糸口金
3 連続フィラメントが金型の上で融着接着した網状物
4、14、15、16 金型
5、7 本発明の導電性網状体
6 圧着ロール
8 平面状シート[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a network having conductivity. More specifically, a water shielding sheet is installed on the bottom of the waste disposal site for the purpose of preventing groundwater contamination of hazardous substances from the waste disposal site. Therefore, there is a double liner construction method using a water shielding structure having a structure of a water shielding sheet / intermediate layer / water shielding sheet, and the middle layer electrically detects water leakage as a nonwoven fabric / planar conductor / nonwoven fabric. There are two double liner construction methods to detect water leakage by air permeability or pressure detection as a three-dimensional network, and to inject a water-stopping material such as bentonite to the part to repair the water shielding effect. It is required to provide an electrical water leakage detection function, and the conductive network of the present invention relates to a network that can be suitably used for such an electrical detection method.
[0002]
[Prior art]
In order to prevent groundwater contamination of hazardous substances from the waste disposal site, the bottom surface of the waste disposal site is formed with a water-blocking structure, and a planar drainage material that collects and drains sewage flowing away from the waste layer is formed on the bottom. in use. Filaments disclosed in Japanese Patent Publication No. 58-9186 and Japanese Patent Laid-Open No. 11-247060 are fused and integrated into the surface drainage material, and the entire surface drainage material has an uneven shape and has a certain thickness. A pine-like three-dimensional network is used.
[0003]
Moreover, as a water-impervious structure of the above-mentioned waste disposal site, it is simpler to use a rubber sheet or a plastic sheet as a water-stopping material as compared with a rigid construction method such as cementing. Compared to the rigid construction method, sheets are more likely to be damaged by heavy machinery during construction or landfilling, and there is a problem of water leakage if they are damaged.Attempts to improve these have been made, and water-stop sheet materials are placed above and below in the middle layer. In general, the double liner method of arranging a porous body such as a three-dimensional network or concavo-convex film, and a planar conductor using an electrical detection method for water leakage, is a method for detecting water leakage using fluid detection methods such as pressure and air permeability. It is being constructed.
[0004]
The planar conductor by the electrical detection method is easy to detect water leakage, but is difficult to repair after detection of the water leakage location, and the combined use with the porous body is desirable. For this water leak detection, a conductive non-woven fabric mixed with conductive fibers as a detection material or a non-woven fabric integrated with a non-woven fabric and a metal foil such as aluminum foil is used as a water-proof structure that sandwiches a water-stop sheet material to dispose of waste. If the ground surface of the landfill portion of the field is a conductive nonwoven fabric with one electrode sandwiched between water-impervious sheets and the other electrode, the water-stop sheet is damaged and water leaks into the conductive nonwoven fabric. It is connected and detects water leakage, and it is also conceivable to specify a water leakage zone by dividing the conductive nonwoven fabric or to detect the scale of water leakage with the electrical resistance of the conductive nonwoven fabric.
[0005]
[Problems to be solved by the invention]
In the double liner construction method described above, the inventors focused on the invention of a three-dimensional network body, which is a porous body sandwiched between water-stopping sheet materials, focusing on the recovery function of a leaked portion. And a three-dimensional network formed into a mat-like shape having a certain thickness as a whole, and the filaments disclosed in Japanese Patent Application Laid-Open No. 11-247060 are fused and integrated. Recently, we developed a three-dimensional network of pleats that is lighter, has a higher porosity, and a higher compressive stress than conventional drainage materials, and has improved rigidity and pressure resistance in the thickness direction. The detection function of water leakage was not considered, and there was a problem that some kind of detection function had to be provided separately.
[0006]
The object of the present invention is, first of all, to provide a planar material for the water-impervious structure of the above-mentioned waste disposal site, which has conductivity to the porous mesh body and can easily detect water leakage. The second purpose is the application where the earth pressure is applied and the compressive stress is always applied in the thick direction. The compressive stress is larger than that of the conventional drainage material, and the high porosity can be maintained with less decrease in thickness even under high load. When a three-dimensional network is used as the above-mentioned water-impervious structure, it provides a water leakage detection function, and has a double liner construction method for water leakage restoration and water leakage detection function for safer waste disposal. Is to provide a place.
[0007]
In addition, in order to ensure electroconductivity as a nonwoven fabric, since the above-mentioned conductive nonwoven fabric is created by the method of blending into a nonwoven fabric when using conductive fibers such as carbon fibers and metal fibers, There is a problem that the conductivity cannot be ensured unless the fibers are mixed with at least 10 to 20% by weight for the convenience of forming a network of conductive fibers as a whole nonwoven fabric by contacting the fibers. Most of the conductive fibers described above are rigid, and there is a big problem of carding that is indispensable for blending, and there is a big problem that a conductive nonwoven fabric cannot be made at low cost. In addition, conductive non-woven fabric made by integrating metal foil such as aluminum foil as a conductive material is a water shielding structure for waste disposal sites, and it is inevitable to corrode with gas such as hydrogen sulfide, There is a problem in long-term conductivity retention.
[0008]
[Means for Solving the Problems]
The present invention comprises a large number of conductive continuous filaments having a thickness of 0.1 to 1.5 mm, which are made of a thermoplastic synthetic resin containing 10 to 40% by mass of carbon black having an average particle size of 0.1 to 5 μm. It is a net-like body that is superposed in a net shape, fused and bonded at the intersection, and has a basis weight of 100 g / m 2 or more, characterized by conductivity. This is a network having a filament surface electrical resistance of 1 × 10 5 Ω / cm or less.
[0009]
Further, a mesh body in which conductivity is enhanced by adding yarns of hydrogen sulfide-resistant fibers such as carbon fiber and stainless steel fiber having better conductivity, specifically, a continuous structure of the mesh body. When the filament is in an unsolidified state, it can be obtained by pressure-bonding to the yarn and integrating it with the conductive mesh. In this case, there is no particular problem even if the surface electrical resistance of the conductive network slightly exceeds 1 × 10 5 Ω / cm, and it is sufficient that the entire network is 1 × 10 5 Ω / cm or less.
[0010]
The present invention is a conductive solid network having a good pressure resistance, and is a material having a function capable of repairing a place where a water leakage point is detected by injecting a water-impermeable material into the gap. The conductive continuous filaments constituting the body were allowed to flow down onto a mold with concavo-convex sculptures and cooled and solidified while fusing and bonding the intersections to form a three-dimensional network that was integrated and shaped. In addition, because it is used as a water-blocking structure that forms the bottom of an industrial waste disposal site, pressure resistance is required more than usual. It is convenient to use a mold having a trapezoidal block arranged on a plane, such as removed, and having a shape in which the upper side and the bottom side of the trapezoid are on the same plane. The one that is densely installed parallel to the direction A pleat made of this mold, in which a plurality of continuous ridges and grooves arranged in a pleated form and arranged in order in the length direction are alternately formed in a cross section in the thickness direction. The shape of the solid network is optimal.
[0011]
The basic mesh body of the present invention uses a sheet having a flat mold, preferably a sheet having a substantial thickness of 0.1 to 4 mm by pressing the mesh body against the flat mold with a smooth flat roll. It is easy to integrate with a spunbond nonwoven fabric or a polyethylene sheet as a water-impermeable layer when they are supplied together with the smooth flat roll and pressed with the smooth flat roll. And can.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples. FIG. 1 shows a schematic side view of an apparatus for producing a conductive network combined with a nonwoven fabric, in which a polyester spunbond nonwoven fabric is bonded to a sheet-like network according to an embodiment of the present invention. FIG. 2 shows a schematic side view of an apparatus for producing a conductive three-dimensional network using a mold engraved with irregularities in FIG. 5C.
[0013]
The form of the conductive mesh according to the present invention is exemplified by, for example, FIG. 3 of the sheet-like mesh and FIG. 4 of the three-dimensional mesh, both of which are the flat mold shown in FIG. 5C is used. The mold illustrated in FIG. 5C is engraved with unevenness, and will be described with reference to FIG. 2. Thermoplastic in which 10 to 40% by mass of carbon black having an average particle diameter of 0.1 to 5 μm is kneaded. A large number of continuous filaments 1 made of a synthetic resin and having a thickness of 0.1 to 1.5 mm are discharged from a spinneret 2 for melt spinning onto a
[0014]
The material used for the continuous filament of the present invention is a thermoplastic resin such as a polyester such as polypropylene, polyethylene, polyethylene terephthalate, and a polyamide such as nylon 6, and these copolymers are more preferable in order to reinforce flexibility. Polymer blends and polymer alloys are also preferred.
[0015]
The continuous filament of the present invention is characterized in that the material contains 10 to 40% by mass of carbon black having an average particle diameter of 0.1 to 5 μm and has electrical conductivity. However, it is 1 × 10 5 Ω / cm or less. The carbon black used in the present invention is preferably one that has not been surface-treated with wax or the like, and when it is prepared using a master batch, the above conditions are often satisfied when an inexpensive product is used. Also, the average particle size is preferably 0.1 to 5 μm, and if it is too fine, it will disperse too much, resulting in poor contact between carbon particles, and if it is not added excessively, it will be difficult to ensure conductivity and it will be too large. However, since the same state occurs due to poor contact of the particles, both are not preferable in order to ensure conductivity with a small addition amount. 10-40 mass% is preferable and, as for the addition amount of carbon black, 15-25 mass% is more preferable. If it is less than 10% by mass, the conductivity is extremely lowered, and if it is 40% by mass or more, it becomes difficult to form a continuous filament, and the decrease in strength is extremely undesirable.
[0016]
The thickness of the continuous filament of the present invention is preferably 0.1 to 1.5 mm from the viewpoint of strength and rigidity, and if it is thicker than 1.5 mm, it is difficult to form the mesh of the present invention, and if it is thinner than 0.1 mm, it becomes rigid. This is not preferable because problems are likely to occur. Further, the basis weight of the sheet-like network according to the present invention is approximately 100 to 1000 g / m 2 depending on the application, and the three-dimensional network having voids is approximately in the range of 100 to 3000 g / m 2 depending on the application. In the case of intending to enhance the strength, there is a problem of pressure resistance due to the product of the strength and the number of continuous filaments, and 250 to 1500 g / m 2 is preferable. In order to ensure conductivity, the network object of the present invention reduces the thickness of the filament and increases the filament density. However, if the basis weight is less than 100 g / m 2 , the number of fiber constituents will be reduced. Insufficient fiber intersections make it difficult to secure conductivity, which is not preferable.
[0017]
The thickness of the conductive and non-conductive three-dimensional network used in the present invention is preferably 4 to 50 mm for the purpose of strengthening the pressure resistance. If the thickness exceeds 50 mm, the continuous filament contacts the mold. In addition, it is not preferable because it is cooled and difficult to reach and becomes uneven, and because of poor adhesion due to fusion bonding, it is practically difficult to manufacture. In addition, the metal mold | die used for this invention WHEREIN: For the convenience of using the press roll 6, it is preferable that a metal mold | die upper surface and a bottom face are parallel, and the convex part upper surface of a metal mold | die has all the convex part upper surfaces in the same plane.
[0018]
The conductive yarn used in the present invention is a carbon fiber excellent in chemical resistance, a metal wire or metal fiber excellent in hydrogen sulfide resistance electrical conductivity such as stainless steel, and a plated fiber of these metals, including a multifilament, This refers to electrically conductive yarn such as monofilament, spun yarn and split yarn.
[0019]
The flat body to be attached means a water shielding sheet such as polyethylene, spunbond, needle punch, spunlace or impregnated non-woven fabric, and in the case of non-woven fabric, it is economically polyethylene terephthalate spunbond with a weight of 20 to 300 g / m2. Nonwoven fabrics are particularly preferred. Moreover, what adhered the thermoplastic film in which many uneven | corrugated protrusions are formed in the thickness direction may be used. As the film, a commercially available film is appropriately adopted. For example, “Geogrid” manufactured by Takiron is suitable.
[0020]
The three-dimensional net-like body of the present invention is preferably reinforced with a flexible net, and the flexible net is a woven net such as a fishing net having a mesh size of 15 to 50 mm □, a cold raft using a split yarn, a multiple Alternatively, yarns such as monofilaments that are woven or stretched in the vertical and horizontal directions, scrim nets, and the like are conveniently used, and a polyethylene terephthalate fishing net is particularly preferable in terms of strength reinforcement.
[0021]
(Operation) Since the network of the present invention is added with an appropriate amount of carbon black that generates electric conductivity and has at least a surface electric resistance of 1 × 10 5 Ω / cm, When the water-impervious structure of the double liner method is sandwiched between the water-impervious sheet on the bottom surface, if the water-impervious sheet breaks and leaks water, it is extremely easy to detect water leaks through electrical detection. The location can be specified and can be used conveniently. Further, by forming the network of the present invention into a three-dimensional network or combining it with the three-dimensional network, the three-dimensional network is composed of continuous filaments, and liquids such as water easily pass through the network. Therefore, it is very convenient for detecting water leakage at the waste disposal site and repairing water leakage. Specifically, since the gaps between the water shielding sheets can be secured larger than those using a conductive nonwoven fabric, a water blocking material such as bentonite suspension can be sent to the water leaking location to facilitate water leakage repair. . Furthermore, compared to the one using a conductive nonwoven fabric using a metal foil, the network of the present invention uses carbon black as a conductive material, and therefore is less susceptible to corrosion-resistant gas. It is very economical because it uses conductive materials on the market.
[0022]
【Example】
Next, the effects of the present invention will be specifically described with reference to examples and comparative examples.
(Examples 1-3, Comparative Examples 1-2) The mesh body of the present invention uses the
[0023]
[Table 1]
[0024]
All of the three-dimensional networks of Examples 1 to 3 could be energized even with a length of 10 m, but Comparative Examples 1 to 2 could not be energized. Furthermore, after sandwiching the upper and lower sides of the three-dimensional network of Example 1 with a polyethylene sheet having a thickness of 1 mm and sealing the side surface in the width direction with clay, it is bent slightly to form a concave shape, and an electric iron is used to form a 5 mm hole in the upper center portion. A nail with a lead copper wire is driven into the position above the hole in the mulch, which is pressed and solidified with a thickness of 5 cm, and connected to the conductive thread of the three-dimensional network. A dry battery was connected to the copper wire, a miniature bulb was connected to it, and the lead copper wire was also connected, but the miniature bulb was not turned on. Therefore, a polyethylene bag containing 2 L of water was prepared, the side above the hole was aimed, and a hole was made in the bag to spray water. After a while, the light bulb was turned on, and it was confirmed that the three-dimensional network of the present invention has a detection function. After that, when the clay on the side was removed and the state of the three-dimensional network was confirmed, considerable water leakage was confirmed.
[0025]
(Examples 4 to 5) The mesh body of the present invention uses the
[0026]
These conductivities were the same as in Example 1. Example 4 was sandwiched between polyethylene sheets in the same manner as in Example 1, and a water leak test was conducted. As a result, the same good results as in Example 1 were obtained. Furthermore, it is sealed again with clay, overlaid on the mulch above the hole in the polyethylene sheet, overlaid with an iron plate, and tap water is poured from one end of the three-dimensional network sandwiched between the concave polyethylene sheets. If the hose was injected vigorously, water came out from the opposite end, and it was estimated that it could be repaired.
[0027]
【The invention's effect】
One of the conductive nets of the present invention is a three-dimensional network pleated cross-section with a triangle connected horizontally, and one side of the three-dimensional network is virtually fixed to the upper and lower surfaces of the three-dimensional network. Although the pressure resistance is improved, the inside of the mesh body is composed of a wall of the mesh body, and the mesh body is composed of a filament of a thermoplastic resin, so that it is bulky and has air permeability and permeability. It is water-based and has a very high porosity, so it is lightweight, convenient to carry and work at the construction site, and has improved strength compared to conventional products, so it can withstand the tougher usage conditions than conventional products. Since it is possible, it is optimal as a three-dimensional network body of a double liner construction method, which is a water-impervious structure of a waste disposal site, and furthermore, since an electrical water leakage detection function is also given, when using the network body of the present invention, With a better water shielding structure , It can contribute to the improvement of the safety of waste disposal sites. Further, a water-impervious substance such as bentonite suspension can be sent to the water leakage location to easily repair the water leakage. In addition, since the conductive network of the present invention is a network made of a thermoplastic resin, it is excellent in flexibility, has no deterioration, and contains carbon black as a conductive material in the resin. It is difficult to be affected by the corrosion-resistant gas at the disposal site, and can be highly reliable as a water shielding sheet material.
[Brief description of the drawings]
FIG. 1 is a schematic view of an apparatus for producing a conductive sheet network according to the present invention.
FIG. 2 is a schematic view of an apparatus for producing a conductive three-dimensional network according to the present invention.
FIG. 3 is a perspective view showing an
FIG. 4 is a perspective view showing a seventh embodiment of the three-dimensional network according to the present invention.
FIG. 5: Example of mold A: Flat mold B used for a sheet-like network B: Example C used for a three-dimensional network with a pleat cross section C: Mold A engraved with a flat part
D: Example of conventional mold [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Continuous filament 2 Spinneret 3
Claims (11)
Priority Applications (1)
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JP2001014083A JP4571318B2 (en) | 2001-01-23 | 2001-01-23 | Conductive network |
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JP2001014083A JP4571318B2 (en) | 2001-01-23 | 2001-01-23 | Conductive network |
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JP5866894B2 (en) * | 2011-09-07 | 2016-02-24 | 株式会社大林組 | Water leak detection system |
JP2013094254A (en) * | 2011-10-28 | 2013-05-20 | Suzuran Kk | Method and device for manufacturing absorbing material with x-ray contrast medium |
JP6714788B1 (en) | 2018-09-26 | 2020-06-24 | 住友理工株式会社 | Capacitance sensor, manufacturing method thereof, and mesh-like flexible electrode for capacitance sensor |
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JPS6014136U (en) * | 1983-07-04 | 1985-01-30 | 大和紡績株式会社 | Vegetation mesh |
JPS63295761A (en) * | 1987-05-26 | 1988-12-02 | カネボウ株式会社 | Antistatic fiber and its production |
JPH07145513A (en) * | 1993-11-24 | 1995-06-06 | Kanebo Ltd | Polyolefin-based electrically conductive conjugate fiber |
JPH07197438A (en) * | 1994-01-07 | 1995-08-01 | Daiwabo Co Ltd | Civil engineering material |
JPH09210836A (en) * | 1996-01-31 | 1997-08-15 | Takiron Co Ltd | Water shielding sheet and laying structure of its protective member |
JPH10227033A (en) * | 1997-02-14 | 1998-08-25 | Daiwabo Co Ltd | Impervious vegetation block material |
JPH10252087A (en) * | 1997-03-13 | 1998-09-22 | Daiwabo Co Ltd | Earth retaining material with drainage function |
JPH11210394A (en) * | 1998-01-22 | 1999-08-03 | Ozeki Kagaku Kogyo Kk | Waterproof sheet and waterproof construction method |
JPH11247060A (en) * | 1998-03-04 | 1999-09-14 | Daiwabo Co Ltd | Biodegradable steric mesh structure |
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2001
- 2001-01-23 JP JP2001014083A patent/JP4571318B2/en not_active Expired - Fee Related
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JPS6014136U (en) * | 1983-07-04 | 1985-01-30 | 大和紡績株式会社 | Vegetation mesh |
JPS63295761A (en) * | 1987-05-26 | 1988-12-02 | カネボウ株式会社 | Antistatic fiber and its production |
JPH07145513A (en) * | 1993-11-24 | 1995-06-06 | Kanebo Ltd | Polyolefin-based electrically conductive conjugate fiber |
JPH07197438A (en) * | 1994-01-07 | 1995-08-01 | Daiwabo Co Ltd | Civil engineering material |
JPH09210836A (en) * | 1996-01-31 | 1997-08-15 | Takiron Co Ltd | Water shielding sheet and laying structure of its protective member |
JPH10227033A (en) * | 1997-02-14 | 1998-08-25 | Daiwabo Co Ltd | Impervious vegetation block material |
JPH10252087A (en) * | 1997-03-13 | 1998-09-22 | Daiwabo Co Ltd | Earth retaining material with drainage function |
JPH11210394A (en) * | 1998-01-22 | 1999-08-03 | Ozeki Kagaku Kogyo Kk | Waterproof sheet and waterproof construction method |
JPH11247060A (en) * | 1998-03-04 | 1999-09-14 | Daiwabo Co Ltd | Biodegradable steric mesh structure |
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