JP4200421B2

JP4200421B2 - Laminated product of fibrous activated carbon knitted fabric with water repellency

Info

Publication number: JP4200421B2
Application number: JP2002204396A
Authority: JP
Inventors: 泰功河合; 弘生福井
Original assignee: Toyobo Co Ltd
Current assignee: Toyobo Co Ltd
Priority date: 2002-07-12
Filing date: 2002-07-12
Publication date: 2008-12-24
Anticipated expiration: 2022-07-12
Also published as: JP2004042494A

Description

【０００１】
【発明の属する技術分野】
本発明は、炭化可能な原料有機繊維の編物を炭化・賦活処理することによって得られる繊維状活性炭の編物であって、積層加工などの加工性に富み引裂きや折り曲げに対して耐久性があり、取り扱い性が良好で通気性の高い有機ガスの吸着性能に優れた撥水性を有する繊維状活性炭編物に関する。詳しくは、本発明はマスクや脱臭パッド、脱臭シーツなどのメディカル用品、有害ガスから身体を守る防護服、各種の空気清浄機等に使用される繊維状活性炭編物に関する。特に、本繊維状活性炭編物をシート材料や成形品と積層、貼付等で組み合わせた加工を施す際に、裂けや破れといった損傷が少なくかつ通気性の高い繊維状活性炭編物に関する。また、本繊維状活性炭編物を単独または他のシート状物と積層して用いたメディカル用品や防護服、フィルター等の用途に使用した際に、裂けや破れといった損傷が少なくかつ通気性が高く、水や汗などに濡れた場合でも高いガスバリア性を有する繊維状活性炭編物の積層品に関するものである。
【０００２】
【従来の技術】
従来、炭化可能な原料有機繊維に炭化処理および賦活処理を施して繊維状活性炭を得ることが提案されている。また、繊維状活性炭がシート形状を成すシート状の繊維状活性炭を得る方法としては、原料有機繊維をフェルトなどの不織布状あるいは織物状・編物状とした後、炭化および賦活処理する方法や原料有機繊維を炭化および賦活処理して繊維状活性炭を得た後にフェルト等の不織布状に加工する方法が挙げられる。
【０００３】
これら繊維状活性炭は元来有するミクロポアの発達した細孔構造によりガスの吸脱着速度が速くかつ非常に大きな吸着性能を有することで種々の用途に利用されている。しかし、炭化および賦活時の収縮により強度が弱く、シワや亀裂が発生したり、取り扱いや他の材料との積層等の加工時に活性炭布が折れたり、切れたりして粉化・脱落して実用に耐えない様態となる。
【０００４】
これらの問題を解決するために特公平１−２４７２５では編地状の繊維状活性炭布帛が提案されている。これによると、柔軟で加工性、耐引張り、引裂き、折り曲げに優れ、取り扱い性が良好な編地状の活性炭布帛が得られる。しかしながら、昨今の活性炭布帛としての高性能化や他の材料との組み合わせにおける高次加工性といった高い要求を満足することはできない。特に、吸着性能と通気性並びに引裂き強力のバランスが十分ではなかった。即ち、単位面積当たりの有機溶剤ガスに対する吸着性能を増大しようと繊維状活性炭編物の絶乾質量を増加させると、密度が増大して圧力損失が増し、通気性が低下すると共に繊維間の自由度が失われて剛性が増し、結果として強度、特に引裂き強度が低下する。
【０００５】
また、連続的な工業生産を想定した場合には、焼成時のコース方向の収縮によりテンションが掛かるために活性炭布の強度が弱い場合には、破れたり・切れたりする。又両端部がカール状として捲れたり、幅方向の収縮が不安定で一定で安定した幅の繊維状活性炭布帛を得ることが困難であった。さらには、収縮の変動が大きく、絶乾質量の変動が大きく、また編目曲がりが起こり、製品の品位が劣るものであった。また、これら繊維状活性炭シートは空気中の水分結露や汗等で濡れた場合にはフィルターや防護服として用いた場合に実用性能を十分発揮できなくなる。
【０００６】
【発明が解決しようとする課題】
本発明は上記の従来技術における問題を解決しようとするものである。すなわち、単位面積当たりの有機溶剤ガスに対する吸着性能が大きく、かつ通気性が高く、引裂強さの強い繊維状活性炭編物であって、さらに空気中の水分結露や汗等で濡れた場合にもフィルターや防護服として用いた場合に高いガスバリア性を維持させるために撥水性を有する繊維状活性炭編物と表布・裏布を重ねてキルティングした積層品を提供しようとするものである。
【０００７】
【課題を解決するための手段】
本発明者らは上記課題を解決するために鋭意検討の結果、本発明に至った。すなわち、本発明は、繊維状高分子前駆体を糸状化し製編した後、炭化・賦活して得られる繊維状活性炭編物において、トルエン吸着性能が２５ｇ／ｍ²以上であり、通気性が２５０cm³／cm²・s以上であり、かつ引裂強さが２．５Ｎ以上であることを特徴とし、さらには繊維状活性炭編物に撥水剤を付与することにより、撥水度が２以上より好ましくは４以上であることを特徴とする繊維状活性炭編物である。
また、繊維状高分子前駆体がフェノール系繊維であって、その糸状が１９７ｄtex以上の太さである繊維状高分子前駆体を炭化・賦活して得られる繊維状活性炭編物である。さらには、絶乾質量が８０〜２５０ｇ／ｍ²であり、ＢＥＴ法による比表面積が１０００〜３０００ｍ²／ｇであり、編組織がリブ編み又は両面編みである繊維状活性炭編物と表布・裏布を重ねてキルティングした積層品である。
【０００８】
【発明の実施の形態】
繊維状活性炭シートは可とう性に優れるために各種フィルターやエレメントとして各種有機溶剤のガスを吸着するために用いられる。シートの形成方法には前述のように、原料有機繊維をフェルトなどの不織布状あるいは織物状とした後、炭化および賦活処理する方法や原料有機繊維を炭化および賦活処理して繊維状活性炭を得た後にフェルト等の不織布状に加工する方法が挙げられるが、柔軟性や加工性から編地状の繊維状活性炭シートが優れる。他の繊維材料等との積層加工や防護衣のようにシート自体が動きを伴う場所で取り扱われる場合には特にその柔軟性から編物状であることが特に有利である。その繊維状活性炭編物を得る工程については繊維状高分子前駆体の糸状をあらかじめ編物にした後、炭化・賦活して繊維状活性炭編物とする方法が良く、活性炭繊維糸状を製編することは活性炭繊維の強度が弱いため実際工業的には不可能である。
【０００９】
該活性炭編物の吸着性能としてはＪＩＳＫ１４７７「繊維状活性炭試験方法」の５．７項に記載のトルエン吸着性能で２５ｇ／ｍ²以上（２５℃、１／１０希釈の条件下）、好ましくは４０ｇ／ｍ²以上必要である。この吸着量を下回る場合は、フィルタや防護服として用いた場合に実用性能を十分発揮できなくなる。又、該活性炭編物の通気性としては、ＪＩＳＬ１０１８「ニット生地試験方法」に記載の方法による通気性で２５０cm³／cm²・s以上必要である。これを下回る場合はフィルターにした場合には圧力損失の増大、又防護服にした場合には着用感の低下といった問題が起こる。
【００１０】
繊維状活性炭編物を目的に応じて加工する場合、例えば織編物や不織布といった他の繊維集合体と積層する場合、工業的に加工しようとすれば該繊維状活性炭編物に機械的応力が加わり、裂けや破れが生じる。これを防ぐためには少なくとも、ＪＩＳＬ１０１８に記載の方法による引張強さが１．０Ｎ以上、ＪＩＳＬ１０９６ 8.15.4項に記載の引裂強さ（トラペゾイド法）が１．０Ｎ以上好ましくは２．５Ｎ以上必要である。これを下回る場合は、積層加工やその他の製品化のための加工を施す場合に生産性が大幅に低下し実用的でなくなる。
【００１１】
このような、引裂強さの大きい繊維状活性炭編物を得るには、前駆体繊維がフェノール系繊維であることが望ましい。繊維状活性炭の前駆体繊維としては他にセルロース系、ピッチ系やＰＡＮ系が知られている。セルロース系繊維を前駆体とする場合は炭化・賦活により十分な吸着性能を発揮する比表面積を有する繊維状活性炭が得られるが、収率が低く、また収縮率が大きいので剛性が高く、布帛の強度、特に引裂強さの小さいものとなる。ＰＡＮ系繊維を前駆体繊維とする場合には、比較的布帛強度の高いものが得られるが、大きな吸着性能を有する繊維状活性炭を得ることが困難である。ピッチ系繊維を用いるとセルロース系とＰＡＮ系の中間程度の強度と吸着性能が得られるが、必ずしも両方の特性とも満足するものではない。
【００１２】
本発明においては、このような状況を鑑み前駆体繊維の糸状としてはステープルから得られる紡績糸あるいはフィラメント糸状いずれの場合でも良く、また両者を混合した混繊糸状でもかまわない。単繊維繊度は１．１ｄtex〜５．５ｄtexで、撚り合わせた糸状の繊度は１９７ｄtex以上、好ましくは２９５〜５９０ｄtexが良い。１９７ｄtex以下の場合、製編し炭化・賦活した後の繊維状活性炭編物の密度が緻密となって十分な通気性が得られない。また、柔軟性が不足して後加工時や使用時に裂けや破れの発生に繋がる。
【００１３】
このような糸状を用いて原料編地を製編するにあたって、繊維状活性炭にした後の生地の伸び率、柔軟性や通気性を保持するためには編組織としてはリブ編み又は両面編みが好ましい。この中でもフライス編みやスムース編みは連続焼成する際に生地の収縮によるコース方向の応力によって生じる生地の耳部の巻き込みがほとんどなく、繊維状活性炭編物の有効幅を確保する点で好ましい。
【００１４】
繊維状活性炭シートは炭化・賦活されることにより機械的強度が低下する。特に引裂強さが極端に低下すると後加工時や使用時の破壊に繋がり不都合である。
ここで、繊維状活性炭編物の柔軟性や強度を出来るだけ保持するためには、炭化・賦活前の原料編物の破断時伸び率がコース・ウェール方向ともに１００％以上を有することで解決できることが本発明によって見出された。破断時の伸び率が１００％以上を有するように製編を設計された原料編物を用いて炭化・賦活された繊維状活性炭編物も本発明に含まれる。
【００１５】
このようにして得られた原料編物を活性炭にする際には、バッチ式あるいは連続式に炭化・賦活工程を施すことで得られるが、繊維状活性炭編物の生地特性や吸着性能の均一性を得ることや工業的生産性を考慮すると炭化・賦活を連続的に行うことが好ましい。原料編物を３５０℃以上１０００℃以下の温度の不活性雰囲気で炭化し、次いで５００℃以上１０００℃以下の温度で炭素と反応する水蒸気、酸素、二酸化炭素などを含む活性な雰囲気で賦活し活性炭化する。又、場合によっては雰囲気条件を制御することにより炭化と賦活を同時に行うことも可能である。尚、賦活処理、すなわち活性炭化を行う際の最高到達温度を１０００℃以上にすると異常収縮などによりシワの発生を伴うことがあり、最高到達温度は１０００℃以下にすることが好ましい。これにより、比表面積が１０００〜３０００ｍ²／ｇである編物状の繊維状活性炭が得られる。
又、得られた活性炭布帛の絶乾質量は、８０〜２５０ｇ／ｍ²、好ましくは１００〜１５０ｇ／ｍ²が良い。８０ｇ／ｍ²以下の場合、活性炭の吸着性能が低くかつ引裂強さが弱く、２５０ｇ／ｍ²以上の場合通気性や柔軟性が悪くなるといった問題が起こるためである。
【００１６】
繊維状活性炭編物に撥水性を付与する方法としては、通常スプレーによる噴霧や含浸加工などが考えられるが、均一性を考えると含浸加工が好ましい。
【００１７】
又、撥水剤としてはフッ素樹脂系、ワックス系、セルロース反応系、シリコン樹脂系等特に限定されるものではなく、添着量は撥水剤固形分として０．１〜１５ｗｔ％、好ましくは０．５〜５ｗｔ％であればよい。添着量が０．１ｗｔ％以下では撥水度が低く、１５ｗｔ％以上であれば繊維状活性炭編物の性能が低下するためである。
【００１８】
繊維状活性炭編物を目的に応じて加工する場合、例えば織編物や不織布といった他の繊維集合体と積層する場合、不織布状のホットメルト接着剤を用いて積層する方法が知られているが、繊維状活性炭布の質量が大きい際にこの方法を用いると積層品の剛性が増し、防護衣等にした場合に着用感が悪くなったり、又、
接着剤によって活性炭布表面が被覆され吸着性能の低下や通気性の低下といった問題が起こる。そこで、これらの問題を解決するためにはキルティング加工により積層品とすることが好ましい。
【００１９】
【実施例】
以下、実施例に基づいて本発明を詳細に述べる。ただし、下記実施例はこの発明を制限するものではなく、前・後記の主旨を逸脱しない範囲で変更実施することは全て本発明の技術範囲に包含される。
尚、編地の各特性値の測定法は次の通りである。布帛の絶乾質量、目付、厚さ、見掛比重、通気性、引張強さ、伸び率、剛軟性については、ＪＩＳＬ１０１８に準拠、引裂強さはＪＩＳＬ１０９６に準拠し、繊維状活性炭のトルエン吸着性能は、ＪＩＳＫ１４７７に準拠した。また、編物の撥水度はＪＩＳＬ１０９２６．２に準拠した。
【００２０】
（実施例１）
単繊維繊度２．２ｄtex、糸状の繊度２９５ｄtexのフェノール系繊維を使用し、２２ゲージ両面丸編み機によりフライス編地を編成した。この編地は、目付２２５ｇ／ｍ²、厚さ１．６５ｍｍ、見掛比重０．１４ｇ／cm³、通気性は３２０cm³／cm²・sであり、引張強さはコース方向３７．２Ｎ／cm、ウェール方向５３．９Ｎ／cm、伸び率はコース方向１４７％、ウェール方向１６０％に設定した。
この編地を常温から８９０℃まで３０分間、不活性雰囲気中で炭化させ、次に水蒸気１２ｗｔ％を含有する雰囲気中８９０℃の温度で９０分間賦活した。得られた編物状の繊維状活性炭布はコース方向に２０％、ウェール方向に２８％の収縮を生じたが、耳部のカールもなく、シワや歪みのないしなやかなものであった。得られた編地状の繊維状活性炭布は、絶乾質量１２０ｇ／ｍ²、厚さ１．０５ｍｍ、比重０．１１ｇ／cm³、通気性は３３０cm³／cm²・s、引張強さはコース方向２．０Ｎ／cm、ウェール方向１．５Ｎ／cm、伸び率はコース方向３５％、ウェール方向９５％、引裂強さはコース方向３．８Ｎ、ウェール方向４．０Ｎ、剛軟度はコース方向６．４mＮ・cm、ウェール方向６．２mＮ・cmと柔軟なものであった。又、この繊維状活性炭布のトルエン吸着性能は５６ｇ／ｍ²、ＢＥＴ比表面積は１３８０ｍ²／ｇと非常に高い吸着性能を有するものであった。
得られた編物状の繊維状活性炭布を８２．５ｄｔｅｘと２２ｄｔｅｘエステル使いの６５ｇ／ｍ²トリコット地の間に挟み、９８．５ｄｔｅｘのエステルスパン糸を用いて２．５４ｃｍダイヤ柄にキルティング加工した。加工時、活性炭布の破れや切断等トラブルはなく、また得られた積層品は非常に柔軟な物であった。この繊維状活性炭編物の積層品を、３ｗｔ％のフッ素系撥水剤(明成化学工業（株）アサヒガードAG970)、０．３ｗｔ％の架橋剤(住友化学工業（株）スミテックスレジンＭ−３)及び、０．１ｗｔ％の触媒(住友化学工業（株）スミテックスアクセラレータＡＣＸ)を含む加工浴にパッド乾燥後、１７０℃で固着処理を施し、撥水剤固形分で０．５ｗｔ％添着させた。
【００２１】
（比較例１）
実施例１と同じ繊維状活性炭編物で、撥水加工処理を施さないものを比較例１とした。
得られた編物状の繊維状活性炭布を、予め３ｗｔ％のフッ素系撥水剤(明成化学工業（株）アサヒガードAG970)、０．３ｗｔ％の架橋剤(住友化学工業（株）スミテックスレジンＭ−３)及び、０．１ｗｔ％の触媒(住友化学工業（株）スミテックスアクセラレータＡＣＸ)を含む加工浴にパッド乾燥後、１７０℃で固着処理を施し、撥水剤固形分で０．５ｗｔ％添着させた、８２．５ｄｔｅｘと２２ｄｔｅｘエステル使いの６５ｇ／ｍ²トリコット地の間に挟み、９８．５ｄｔｅｘのエステルスパン糸を用いて２．５４ｃｍダイヤ柄にキルティング加工した。加工時、活性炭布の破れや切断等トラブルはなく、また得られた積層品は非常に柔軟な物であった。
【００２２】
（比較例２）
単繊維繊度２．２ｄtex、糸状の繊度５９０ｄtexのフェノール系繊維を使用し、１４ゲージ片面丸編機により天竺編地を編成した。この編地は、目付２２０ｇ／ｍ²、厚さ０．９４ｍｍ、見掛比重０．２３ｇ／cm³、通気性は２１０cm³／cm²・s、引張強さはコース方向２０．６Ｎ／cm、ウェール方向１３．７Ｎ／cm、伸び率はコース方向８４％、ウェール方向１７７％に設定した。
この編地を常温から８９０℃まで３０分間で不活性雰囲気中で炭化させ、次に水蒸気１２ｗｔ％を含有する雰囲気中８９０℃の温度で９０分間賦活した。得られた編物状の繊維状活性炭布はコース方向に３０％、横方向に２５％の収縮を生じた。
得られた編地状の繊維状活性炭布は、絶乾質量１２５ｇ／ｍ²、厚さ０．８９ｍｍ、比重０．１４ｇ／cm³、引張強さはコース方向２．９Ｎ／cm、ウェール方向１．１Ｎ／cm、伸び率はコース方向２６％、ウェール方向８５％、引裂強さはコース方向２．５Ｎ、ウェール方向２．０Ｎ、剛軟度はコース方向６．７mＮ・cm、ウェール方向６．１mＮ・cmと柔軟なものであった。又、この繊維状活性炭布のトルエン吸着性能は５９ｇ／ｍ²、ＢＥＴ比表面積１３８０ｍ²／ｇと非常に高い吸着性能を有するものであったが、通気性が１７５cm³／cm²・sと低く、又、耳部にはカールが発生し加工性の非常に悪いものとなった。
得られた編物状の繊維状活性炭布を８２．５ｄｔｅｘと２２ｄｔｅｘエステル使いの６５ｇ／ｍ²トリコット地の間に挟み、９８．５ｄｔｅｘのエステルスパン糸を用いて２．５４ｃｍダイヤ柄にキルティング加工した。積層品は、非常に柔軟であったが、キルティング加工時、繊維状活性炭布の耳部カールの影響で非常に加工性が悪いものであった。
この繊維状活性炭編物の積層品を、０．０３ｗｔ％のフッ素系撥水剤(明成化学工業（株）アサヒガードAG970)、０．００３ｗｔ％の架橋剤(住友化学工業（株）スミテックスレジンＭ−３)及び、０．００１ｗｔ％の触媒(住友化学工業（株）スミテックスアクセラレータＡＣＸ)を含む加工浴にパッド乾燥後、１７０℃で固着処理を施し、撥水剤固形分で０．００５ｗｔ％添着させた。
【００２３】
上記実施例および比較例で得た材料の撥水度を表１に示す。
【００２４】
上記実施例および比較例で得た材料を純水の中に１分間浸漬後、取出し脱水した。この時の材料に対する純水の含水率は表２の通りであった。
【００２５】
この材料を、図１のように２５℃に設定したインキュベータ内の容器にセットし、容器内にトルエン１０μLを入れたポットを置き、下流側のガス濃度を一定時間ごとにシリンジでサンプリングした。
このとき、ガスクロで測定した結果を図２に示す。
【００２６】
【表１】

【００２７】
【表２】

【００２８】
以上のように、実施例１は、繊維状活性炭編物を撥水処理することによって、繊維状活性炭編物の積層品が水や汗等に濡れた場合においても高いガスバリア性を有するが、撥水処理をしていない比較例１ではガスバリア性の低下が起こる。
又、比較例２は繊維状活性炭編物の積層品を撥水処理したが、撥水度が低いために、繊維状活性炭編物の積層品が水や汗等に濡れた場合においてガスバリア性が低下する結果であった。
【００２９】
【発明の効果】
以上説明したように、本発明の繊維状活性炭編物は、糸状が１９７ｄtex以上の太さのフェノール系繊維を、破断時伸び率がコース方向、ウェール方向共に１００％以上であるリブ編み又は両面編みに製編した繊維状高分子前駆体を、炭化・賦活して活性炭化する事で、単位面積当たりの有機溶剤ガスに対する吸着性能が大きく、通気性が高く、かつ引裂強さの強い、品質および品位の優れた繊維状活性炭を提供する事が可能であり、かつ得られた繊維状活性炭編物を撥水処理する事によって、水や汗などで濡れた場合においても優れたガスバリア性能を有する繊維状活性炭編物の積層品を提供する事が可能である。
【図面の簡単な説明】
【図１】図１は、ガスバリア性を評価した試験容器の概略図である。
【図２】図２は、ガスバリア性を評価したときの結果をグラフ化したものである。
【符号の説明】
Ａ：繊維状活性炭編物Ｂ：ガラス容器Ｃ：ガラスポット
Ｄ：トルエン（液体）Ｅ：シリコンキャップ[0001]
BACKGROUND OF THE INVENTION
The present invention is a fibrous activated carbon knitted fabric obtained by carbonizing and activating a knitted raw material organic fiber knitted fabric, is rich in workability such as laminating, and is durable against tearing and bending, The present invention relates to a fibrous activated carbon knitted fabric having water repellency that is excellent in handling properties and has high air permeability and adsorbability of organic gas. Specifically, the present invention relates to a fibrous activated carbon knitted fabric used for medical supplies such as a mask, a deodorizing pad, and a deodorizing sheet, protective clothing for protecting the body from harmful gases, various air purifiers and the like. In particular, the present invention relates to a fibrous activated carbon knitted fabric that is less damaging such as tearing and tearing and has high air permeability when subjected to processing in which the fibrous activated carbon knitted fabric is combined with a sheet material or a molded product by lamination, sticking, or the like. In addition, when this fibrous activated carbon knitted fabric is used alone or laminated with other sheet-like materials for medical supplies, protective clothing, filters, etc., there is little damage such as tearing or tearing and high breathability, The present invention relates to a laminate of fibrous activated carbon knitted fabric having high gas barrier properties even when wet with water or sweat.
[0002]
[Prior art]
Conventionally, it has been proposed to obtain a fibrous activated carbon by subjecting a raw material organic fiber that can be carbonized to carbonization treatment and activation treatment. In addition, as a method of obtaining a sheet-like fibrous activated carbon in which the fibrous activated carbon forms a sheet shape, the raw material organic fiber is made into a nonwoven fabric such as felt or a woven / knitted fabric, and then carbonized and activated, or a raw organic material A method of carbonizing and activating the fiber to obtain a fibrous activated carbon and then processing it into a non-woven fabric such as felt.
[0003]
These fibrous activated carbons are utilized in various applications because they have a high gas adsorption / desorption rate and a very large adsorption performance due to the micropore structure developed by micropores. However, strength is weak due to carbonization and shrinkage during activation, wrinkles and cracks occur, activated carbon cloth breaks or breaks during processing such as handling and lamination with other materials, and it is pulverized and dropped off for practical use It becomes a state that can not stand.
[0004]
In order to solve these problems, Japanese Patent Publication No. 1-272525 proposes a knitted fabric fibrous activated carbon fabric. According to this, it is possible to obtain a knitted fabric-like activated carbon fabric that is flexible, excellent in workability, tensile resistance, tearing, bending, and handleability. However, it is not possible to satisfy high demands such as high performance as a recent activated carbon fabric and high-order workability in combination with other materials. In particular, the balance between adsorption performance, air permeability and tear strength was not sufficient. That is, increasing the absolute dry mass of the fibrous activated carbon knitted fabric to increase the adsorption performance to organic solvent gas per unit area increases the density and pressure loss, decreases the air permeability and reduces the degree of freedom between fibers. Is lost and rigidity is increased, resulting in a decrease in strength, particularly tear strength.
[0005]
In addition, assuming continuous industrial production, tension is applied due to the shrinkage in the course direction during firing, so that if the strength of the activated carbon cloth is weak, it may be torn or cut. Further, it has been difficult to obtain a fibrous activated carbon fabric having a constant and stable width, in which both ends are curled and the contraction in the width direction is unstable. Furthermore, the shrinkage variation was large, the absolute dry mass variation was large, the stitch was bent, and the product quality was inferior. In addition, when these fibrous activated carbon sheets are wet with moisture condensation or sweat in the air, they cannot sufficiently exhibit practical performance when used as a filter or protective clothing.
[0006]
[Problems to be solved by the invention]
The present invention seeks to solve the above-described problems in the prior art. In other words, it is a fibrous activated carbon knitted fabric with high adsorption performance for organic solvent gas per unit area, high air permeability, and strong tear strength, and even when wet with moisture condensation or sweat in the air. In order to maintain a high gas barrier property when used as protective clothing, it is intended to provide a laminated product in which a fibrous activated carbon knitted fabric having water repellency and a quilting are overlapped with a front fabric and a back fabric.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. That is, according to the present invention, a fibrous activated carbon knitted fabric obtained by knitting a fibrous polymer precursor into a filament and then carbonizing and activating it has a toluene adsorption performance of 25 g / m ² or more and a breathability of 250 cm ^3. / Cm ² · s or more, and the tear strength is ^2.5 N or more. Further, by imparting a water repellent to the fibrous activated carbon knitted fabric, the water repellency is more preferably 2 or more. It is a fibrous activated carbon knitted fabric characterized by being 4 or more.
In addition, the fibrous activated carbon knitted fabric is obtained by carbonizing and activating a fibrous polymer precursor whose fibrous polymer precursor is a phenolic fiber and whose thread has a thickness of 197 dtex or more. Furthermore, an absolute dry mass 80~250g / m ^2, specific surface area by the BET method is 1000~3000m ² / g, the activated carbon fiber knit knitting structure is ribbed or double-sided knitted and table cloths and back It is a laminated product in which cloth is quilted.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Since the fibrous activated carbon sheet is excellent in flexibility, it is used as various filters and elements for adsorbing various organic solvent gases. As described above, in the sheet forming method, the raw material organic fiber was made into a nonwoven fabric or woven fabric such as felt, and then carbonized and activated, and the raw organic fiber was carbonized and activated to obtain fibrous activated carbon. Although the method of processing it into nonwoven fabrics, such as felt later, is mentioned, the knitted fabric-like fibrous activated carbon sheet is excellent from a softness | flexibility and workability. When the sheet itself is handled in a place with movement, such as laminating with other fiber materials or protective clothing, a knitted shape is particularly advantageous because of its flexibility. As for the process of obtaining the fibrous activated carbon knitted fabric, it is good to make the fibrous polymer precursor yarn into a knitted fabric in advance and then carbonize and activate it to make a fibrous activated carbon knitted fabric. Actually industrially impossible due to weak fiber strength.
[0009]
The adsorption performance of the activated carbon knitted fabric is 25 g / m ² or more (25 ° C., 1/10 dilution condition), preferably 40 g in terms of toluene adsorption performance described in 5.7 of JIS K1477 “Fibrous activated carbon test method”. there is a need / m ² or more. When the amount is less than this adsorption amount, practical performance cannot be sufficiently exhibited when used as a filter or protective clothing. Further, the air permeability of the activated carbon knitted fabric needs to be 250 cm ³ / cm ² · s or more according to the method described in JIS L1018 “Testing method for knit fabric”. Below this, problems such as an increase in pressure loss when used as a filter and a decrease in wearing feeling occur when used as a protective suit.
[0010]
When processing a fibrous activated carbon knitted fabric according to the purpose, for example, when laminating with other fiber aggregates such as a woven or non-woven fabric, mechanical stress is applied to the fibrous activated carbon knitted fabric and the fiber activated carbon knitted fabric is torn. And tearing occurs. In order to prevent this, at least the tensile strength according to the method described in JIS L1018 is 1.0 N or more, and the tear strength (trapezoid method) described in JIS L1096 8.15.4 is 1.0 N or more, preferably 2.5 N or more. is necessary. Below this range, productivity is drastically reduced when lamination processing or other processing for commercialization is performed, which is not practical.
[0011]
In order to obtain such a fibrous activated carbon knitted fabric with high tear strength, it is desirable that the precursor fiber is a phenol fiber. Other cellulose-based, pitch-based, and PAN-based fibers are known as precursor fibers for fibrous activated carbon. When cellulosic fiber is used as a precursor, fibrous activated carbon having a specific surface area that exhibits sufficient adsorption performance can be obtained by carbonization / activation. However, the yield is low and the shrinkage rate is large, so that the rigidity is high, The strength, particularly the tear strength is small. When PAN-based fibers are used as precursor fibers, those having relatively high fabric strength can be obtained, but it is difficult to obtain fibrous activated carbon having large adsorption performance. When pitch fibers are used, intermediate strength and adsorption performance between cellulose and PAN can be obtained, but both properties are not necessarily satisfied.
[0012]
In the present invention, in view of such a situation, the precursor fiber may be either a spun yarn obtained from staples or a filament yarn, or may be a mixed fiber obtained by mixing the two. The single fiber fineness is 1.1 to 5.5 dtex, and the twisted yarn-like fineness is 197 dtex or more, preferably 295 to 590 dtex. In the case of 197 dtex or less, the density of the fibrous activated carbon knitted fabric after knitting, carbonization and activation becomes dense, and sufficient air permeability cannot be obtained. In addition, lack of flexibility leads to tearing and tearing during post-processing and use.
[0013]
In knitting a raw material knitted fabric using such a yarn shape, rib knitting or double-sided knitting is preferable as a knitted structure in order to maintain the elongation rate, flexibility and breathability of the fabric after it is made into fibrous activated carbon. . Of these, milling and smooth knitting are preferable in that the continuous portions of the fabric are hardly involved in the ears of the fabric caused by the stress in the course direction due to shrinkage of the fabric, and the effective width of the fibrous activated carbon knitted fabric is ensured.
[0014]
The mechanical strength of the fibrous activated carbon sheet decreases due to carbonization and activation. In particular, if the tear strength is extremely reduced, it is inconvenient because it leads to breakage during post-processing or use.
Here, in order to maintain the flexibility and strength of the fibrous activated carbon knitted fabric as much as possible, it can be solved by having the elongation at break of the raw material knitted fabric before carbonization / activation at least 100% in both the course and the wale direction. Found by the invention. A fibrous activated carbon knitted fabric that has been carbonized and activated using a raw material knitted fabric designed so as to have an elongation at break of 100% or more is also included in the present invention.
[0015]
When the raw material knitted fabric thus obtained is made into activated carbon, it can be obtained by subjecting it to a carbonization / activation process in a batch or continuous manner, but it can obtain uniform fabric characteristics and adsorption performance of the fibrous activated carbon knitted fabric. In view of the above and industrial productivity, it is preferable to perform carbonization and activation continuously. Activated carbonization by carbonizing raw material knitted fabric in an inert atmosphere at a temperature of 350 ° C. or higher and 1000 ° C. or lower, and then activated in an active atmosphere containing water vapor, oxygen, carbon dioxide, etc. that reacts with carbon at a temperature of 500 ° C. or higher and 1000 ° C. or lower. To do. In some cases, carbonization and activation can be performed simultaneously by controlling the atmospheric conditions. In addition, when the maximum reached temperature at the time of activation treatment, that is, activated carbonization is set to 1000 ° C. or higher, wrinkles may be generated due to abnormal shrinkage or the like, and the maximum reached temperature is preferably set to 1000 ° C. or lower. Thereby, a knitted fibrous activated carbon having a specific surface area of 1000 to 3000 m ² / g is obtained.
The obtained dry mass of the activated carbon fabric is 80 to 250 g / m ² , preferably 100 to 150 g / m ² . This is because when the amount is 80 g / m ² or less, the adsorption performance of activated carbon is low and the tear strength is weak, and when it is 250 g / m ² or more, problems such as poor air permeability and flexibility occur.
[0016]
As a method for imparting water repellency to the fibrous activated carbon knitted fabric, spraying by spraying or impregnation is usually considered, but in view of uniformity, impregnation is preferable.
[0017]
Further, the water repellent is not particularly limited, such as fluororesin, wax, cellulose reaction system, silicon resin, etc., and the amount added is 0.1 to 15 wt%, preferably 0. What is necessary is just 5-5 wt%. This is because the water repellency is low when the amount of attachment is 0.1 wt% or less, and the performance of the fibrous activated carbon knitted fabric is deteriorated when the amount is 15 wt% or more.
[0018]
When processing a fibrous activated carbon knitted fabric according to the purpose, for example, when laminating with other fiber assemblies such as a woven or knitted fabric, a method of laminating using a non-woven hot melt adhesive is known. If this method is used when the mass of the activated carbon cloth is large, the rigidity of the laminated product will increase, and if it is used as a protective garment, the feeling of wearing will worsen,
The surface of the activated carbon cloth is coated with the adhesive, causing problems such as a decrease in adsorption performance and a decrease in air permeability. Therefore, in order to solve these problems, it is preferable to form a laminated product by quilting.
[0019]
【Example】
Hereinafter, the present invention will be described in detail based on examples. However, the following examples do not limit the present invention, and all modifications made without departing from the gist of the preceding and following descriptions are all included in the technical scope of the present invention.
In addition, the measuring method of each characteristic value of a knitted fabric is as follows. The absolute dry mass, fabric weight, apparent specific gravity, air permeability, tensile strength, elongation rate, stiffness and softness of the fabric conform to JIS L1018, tear strength conforms to JIS L1096, and fibrous activated carbon toluene The adsorption performance conformed to JIS K1477. The water repellency of the knitted fabric conformed to JIS L1092 6.2.
[0020]
(Example 1)
A milled knitted fabric was knitted with a 22 gauge double-side circular knitting machine using phenolic fibers having a single fiber fineness of 2.2 dtex and a yarn-like fineness of 295 dtex. This knitted fabric has a basis weight of 225 g / m ² , a thickness of 1.65 mm, an apparent specific gravity of 0.14 g / cm ³ , an air permeability of 320 cm ³ / cm ² · s, and a tensile strength of 37.2 N / s in the course direction. cm, the wale direction was 53.9 N / cm, and the elongation was set to 147% in the course direction and 160% in the wale direction.
This knitted fabric was carbonized from normal temperature to 890 ° C. for 30 minutes in an inert atmosphere, and then activated for 90 minutes at a temperature of 890 ° C. in an atmosphere containing 12 wt% of water vapor. The obtained knitted fibrous activated carbon cloth had a shrinkage of 20% in the course direction and 28% in the wale direction, but had no curling at the ears and was not wrinkled or distorted. The resulting knitted fabric-like fibrous activated carbon cloth has an absolutely dry mass of 120 g / m ² , a thickness of 1.05 mm, a specific gravity of 0.11 g / cm ³ , a breathability of 330 cm ³ / cm ² · s, and a tensile strength of Course direction 2.0N / cm, Wale direction 1.5N / cm, Elongation rate 35% Course direction, Wale direction 95%, Tear strength 3.8N Course direction, Wale direction 4.0N, Bending softness is Course It was flexible with a direction of 6.4 mN · cm and a wale direction of 6.2 mN · cm. The fibrous activated carbon cloth had a very high adsorption performance with a toluene adsorption performance of 56 g / m ² and a BET specific surface area of 1380 m ² / g.
The obtained knitted fabric-like activated carbon fiber cloth sandwiched between 82.5dtex and 22dtex ester Tsukai of 65 g / m ² tricot, it was quilted to 2.54cm diamond pattern with ester spun yarn 98.5Dtex. At the time of processing, there was no trouble such as breaking or cutting of the activated carbon cloth, and the obtained laminate was very flexible. This fibrous activated carbon knitted product is made up of 3 wt% fluorine-based water repellent (Asahi Guard AG970, Meisei Chemical Co., Ltd.) and 0.3 wt% cross-linking agent (Sumitomo Chemical Co., Ltd., Sumitex Resin M-3). ) And 0.1 wt% catalyst (Sumitomo Chemical Co., Ltd., Smitex Accelerator ACX) after drying the pad, it is fixed at 170 ° C., and 0.5 wt% of water repellent is added. It was.
[0021]
(Comparative Example 1)
The same fibrous activated carbon knitted fabric as in Example 1 that was not subjected to the water repellent treatment was designated as Comparative Example 1.
The obtained knitted fibrous activated carbon cloth was preliminarily made up of 3 wt% fluorine-based water repellent (Asahi Guard AG970, Meisei Chemical Industry Co., Ltd.) and 0.3 wt% cross-linking agent (Sumitomo Chemical Industries, Ltd. M-3) and 0.1 wt% of a catalyst (Sumitomo Chemical Co., Ltd., Sumitex Accelerator ACX) after drying the pad, a fixing treatment is performed at 170 ° C., and the water repellent solid content is 0.5 wt. It was sandwiched between 65 g / m ² tricot fabric using 82.5 dtex and 22 dtex ester, and quilted into a 2.54 cm diamond pattern using 98.5 dtex ester spun yarn. At the time of processing, there was no trouble such as breaking or cutting of the activated carbon cloth, and the obtained laminate was very flexible.
[0022]
(Comparative Example 2)
Tendon knitted fabric was knitted with a 14 gauge single-sided circular knitting machine using phenolic fibers with a single fiber fineness of 2.2 dtex and a yarn-like fineness of 590 dtex. This knitted fabric has a basis weight of 220 g / m ² , a thickness of 0.94 mm, an apparent specific gravity of 0.23 g / cm ³ , a breathability of 210 cm ³ / cm ² · s, a tensile strength of 20.6 N / cm in the course direction, The wale direction was set to 13.7 N / cm, the elongation was set to 84% in the course direction, and 177% in the wale direction.
The knitted fabric was carbonized in an inert atmosphere for 30 minutes from room temperature to 890 ° C., and then activated for 90 minutes at a temperature of 890 ° C. in an atmosphere containing 12 wt% of water vapor. The obtained knitted fibrous activated carbon cloth had a shrinkage of 30% in the course direction and 25% in the transverse direction.
The obtained knitted fabric-like activated carbon fiber cloth, the absolute dry weight 125 g / m ^2, thickness 0.89 mm, specific gravity of 0.14 g / cm ^3, tensile strength is the course direction 2.9 N / cm, wale direction 1 0.1 N / cm, elongation is 26% in the course direction, 85% in the wale direction, tear strength is 2.5N in the course direction, 2.0N in the wale direction, bending resistance is 6.7 mN · cm in the course direction, 6. It was as flexible as 1 mN · cm. This fibrous activated carbon cloth had a very high adsorption performance of 59 g / m ² and a BET specific surface area of 1380 m ² / g, but its breathability was as low as 175 cm ³ / cm ² · s. Also, curling occurred in the ear part, and the processability was very poor.
The obtained knitted fibrous activated carbon cloth was sandwiched between 82.5 dtex and 65 g / m ² tricot using 22 dtex ester, and quilted into a 2.54 cm diamond pattern using an ester spun yarn of 98.5 dtex. The laminated product was very flexible, but at the time of quilting, the processability was very poor due to the effect of the curl of the edge of the fibrous activated carbon cloth.
A laminate of this fibrous activated carbon knitted fabric was prepared by using 0.03 wt% of a fluorine-based water repellent (Asahi Guard AG970, Meisei Chemical Industry Co., Ltd.) and 0.003 wt% of a cross-linking agent (Sumitomo Chemical Industries, Ltd. -3) and pad drying in a processing bath containing 0.001 wt% catalyst (Sumitomo Chemical Co., Ltd., Sumitex Accelerator ACX), and then a fixing treatment at 170 ° C., and a water repellent solid content of 0.005 wt% It was attached.
[0023]
Table 1 shows the water repellency of the materials obtained in the above Examples and Comparative Examples.
[0024]
The materials obtained in the above Examples and Comparative Examples were immersed in pure water for 1 minute, then taken out and dehydrated. The water content of pure water with respect to the material at this time was as shown in Table 2.
[0025]
This material was set in a container in an incubator set to 25 ° C. as shown in FIG. 1, a pot containing 10 μL of toluene was placed in the container, and the downstream gas concentration was sampled with a syringe at regular intervals.
At this time, the result measured by gas chromatography is shown in FIG.
[0026]
[Table 1]

[0027]
[Table 2]

[0028]
As described above, Example 1 has a high gas barrier property even when the laminated product of the fibrous activated carbon knitted fabric is wet with water, sweat, or the like by subjecting the fibrous activated carbon knitted fabric to a water repellent treatment. In Comparative Example 1 in which no gas was added, the gas barrier property was lowered.
In Comparative Example 2, the laminated product of the fibrous activated carbon knitted fabric was treated with water repellency. However, since the water repellency is low, the gas barrier property is lowered when the laminated product of the fibrous activated carbon knitted fabric is wet with water or sweat. It was a result.
[0029]
【The invention's effect】
As described above, the fibrous activated carbon knitted fabric of the present invention is a knitted rib-type or double-sided knitted phenolic fiber having a yarn shape of 197 dtex or more and having an elongation at break of 100% or more in both the course direction and the wale direction. Carbonized, activated, and activated carbonized knitted fibrous polymer precursors provide high adsorption performance for organic solvent gas per unit area, high air permeability, strong tear strength, quality and quality Fibrous activated carbon with excellent gas barrier performance even when wet with water or sweat, etc., by providing water-repellent treatment to the obtained fibrous activated carbon knitted fabric. It is possible to provide a knitted laminate.
[Brief description of the drawings]
FIG. 1 is a schematic view of a test container evaluated for gas barrier properties.
FIG. 2 is a graph showing the results when gas barrier properties are evaluated.
[Explanation of symbols]
A: Fibrous activated carbon knitted fabric B: Glass container C: Glass pot D: Toluene (liquid) E: Silicon cap

Claims

The fibrous activated carbon knitted fabric obtained by carbonizing and activating the fibrous polymer precursor after knitting and knitting, the knitting structure is rib knitting or double-sided knitting, toluene adsorption performance is 25 g / m ² or more, and ventilation Is 250 cm ³ / cm ² · s or more and tear strength is 2.5 N or more, and any one of fluorine resin, wax, cellulose reaction system, and silicone resin water repellent is used as a solid content. Laminated layer for protective clothing with 0.5-5 wt% attached and quilted by overlaying front and back fabric and back fabric of fibrous activated carbon knitted fabric characterized by water repellency of 2 or more according to JIS L1092 6.2 Goods.

Protective taking laminate of claim 1 in which the absolute dry weight of the fibrous activated carbon or knitted fabric characterized in that it is a 80~250g / m ^2.

The laminated article for protective clothing according to any one of claims 1 to ^{2, wherein the} specific surface area of the fibrous activated carbon knitted fabric by the BET method is 1000 to 3000 m ² / g.

The protective article laminated article according to any one of claims 1 to 3, wherein the fibrous polymer precursor has a filament shape having a thickness of 197 dtex or more.

The laminate for protective clothing according to any one of claims 1 to 4, wherein the fibrous polymer precursor is a phenol fiber.

The laminate for protective clothing according to any one of claims 1 to 5, wherein the elongation at break of the fibrous polymer precursor knitted fabric before carbonization / activation is 100% or more in both the course direction and the wale direction. .