JP3656785B2

JP3656785B2 - Adsorption molding

Info

Publication number: JP3656785B2
Application number: JP275497A
Authority: JP
Inventors: 敏昭林; 康広飯塚
Original assignee: Toyobo Co Ltd
Current assignee: Toyobo Co Ltd
Priority date: 1997-01-10
Filing date: 1997-01-10
Publication date: 2005-06-08
Anticipated expiration: 2017-01-10
Also published as: JPH10192704A

Description

【０００１】
【発明の属する技術分野】
本発明は、一定の形状に成形した吸着成形体に関するもので、更に詳しく述べると、液相特に浄水用途に適しており、プラスチックケース等の容器に装填して通水したときのシール性が良く、ショートパスを起こさない吸着成形体に関するものである。
【０００２】
【従来の技術】
活性炭素繊維は外表面積が大きく、浄水用途に使用した場合に水との接触面積が大きくとれるために粒状活性炭に比べ残留塩素の分解除去性能に優れる特徴があり、取扱性の向上等を目的として、一定の形状にバインダーで成形した成形体とし、プラスチック製等の容器に装填されて使用されることが多い。
【０００３】
上記成形体にはバインダーとして繊維状や粉末状の熱溶融性合成樹脂を用い、該熱溶融性合成樹脂を加熱溶融して一体的に成形した成形体が広く知られているが、このように熱溶融性合成樹脂の熱溶融で接着した成形体では、プラスチック製等の容器に装填した時に該成形体と容器の間に僅かな間隙が生じた場合に、通水時にそこでショートパスを起こす問題があった。
【０００４】
【発明が解決しようとする課題】
本発明は以上の点を鑑みて、プラスチック製等の容器に装填して通水したときのシール性が良く、ショートパスを起こさない吸着成形体を提供することにある。
【０００５】
【課題を解決するための手段】
本発明者らは、活性炭素繊維とバインダーを含む一体的に成形した吸着成形体をプラスチック製等の容器に装填し、通水したときのシール性を向上させショートパスを防止する方法について鋭意検討した結果、バインダーとして保水度１５０％以上のフィブリル化繊維を使用し、吸水時の膨張が大きい吸着成形体にすることにより、通水時に吸着成形体が吸水すると同時に膨張して容器と密着し、ショートパスを防止できることを見出し、本発明に到達した。
【０００６】
本発明は、活性炭素繊維と保水度１５０％以上のフィブリル化繊維を含み、一体的に成形された成形体であって、通水時の流体流れ方向と直交方向の成形体膨張率が０．５〜５％であることを特徴とする吸着成形体に関するものである。
【０００７】
本発明において、保水度とはバインダーとして使用するフィブリル化繊維の膨潤の程度を表しており、試料の絶乾重量（ＷＯ）と試料を十分に水に浸漬した後に回転半径１０ｃｍの遠心脱水機中において回転速度３００ｒｐｍで５分間脱水した時の重量（Ｗ）を測定して、次式で求めたものである。
保水度（％）＝｛（Ｗ−ＷＯ）／ＷＯ｝×１００
【０００８】
上記フィブリル化繊維の保水度は１５０％以上、好ましくは２００％以上であることが重要である。このような保水度を有するフィブリル化繊維をバインダーとして使用すると、吸水時に膨張する吸着成形体が得られるのである。
【０００９】
本発明において、成形体膨張率とは、吸水したときの吸着成形体の寸法変化を表しており、この値が大きいほど吸着成形体を容器に装填し、通水したときのシール性が高いと言うことができ、吸着成形体の絶乾時の寸法（ＤＯ）と水中に３０秒浸漬後の寸法（Ｄ）を測定して、次式で求めたものである。
膨張率（％）＝｛（Ｄ−ＤＯ）／ＤＯ｝×１００
【００１０】
上記の方法で求めた吸着成形体の流体流れ方向と直交方向の寸法（例えば、円柱形状の吸着成形体で成形体の上面から底面に向かって流体が流れる場合には、該吸着成形体の直径）の吸水時の膨張率が０．５〜５％であることが本発明の必須要件である。この範囲未満では、吸着成形体の吸水時の膨張が小さく、十分なシール効果が得られない。また、一方この範囲を超えると、以下のような問題が生じる。つまり、本発明の吸着成形体は、後述するように、活性炭素繊維、フィブリル化繊維を水に分散させて均一なスラリーとして、成形型に該スラリーを吸引、あるいは加圧により流し込んで成形型から水を抜いて脱水し、脱型、乾燥する、いわゆる湿式成形法で製造できるが、吸水時の膨張率がこの範囲を超える吸着成形体では、製造時の乾燥工程で不均一に収縮が起き、均質な吸着成形体が得られないのである。
【００１１】
本発明において、活性炭素繊維としては、平均繊維径５〜５０μｍ、繊維長０．５〜１０ｍｍ、比表面積５００〜２０００ｍ²／ｇのものが使用できる。また、その原料については限定されず、セルロース系、ポリアクリロニトリル系、フェノール樹脂系、ピッチ系等のいずれであっても良い。また、活性炭素繊維の含有率は所望する吸着性能に応じて５０〜９９重量％の範囲内で設定することができる。
【００１２】
本発明において、吸着成形体の嵩密度は０．１〜０．３ｇ／ｃｃ、好ましくは０．１２〜０．２５ｇ／ｃｃ、さらに好ましくは０．１５〜０．２ｇ／ｃｃとする。この範囲未満では、吸着成形体の強度が十分でなく、また、この範囲を超えると、吸着成形体の圧力損失が大きくなるのである。なお、嵩密度は吸着成形体の絶乾重量と体積を測定し、絶乾重量を体積で除して求める。
【００１３】
本発明において、一体的に成形された吸着成形体とは、活性炭素繊維とフィブリル化繊維が所定の形状に三次元的に組織化されたもので、該吸着成形体の成形は、活性炭素繊維、フィブリル化繊維を水に分散させて均一なスラリーとして、水が透過することができる多孔壁を有する所定形状の成形型に該スラリーを吸引、あるいは加圧により流し込んで成形型から水を抜いて脱水し、脱型、乾燥することにより行なうことができる。その場合、多孔壁面の配置によって、吸着成形体を構成する活性炭素繊維の配向が制御でき、流体流れ方向に対する活性炭素繊維の繊維軸方向の角度を直角あるいはランダムにすることができる。また、活性炭素繊維では発現できない機能を付加するために、粉末活性炭、粒状活性炭、抗菌活性炭やゼオライト等をスラリーに加えることができ、さらに、必要に応じてスラリーに凝集剤、添加剤等を適宜添加することもできる。
【００１４】
活性炭素繊維の配向について更に詳述すると、例えば、円柱形状で上面から底面に向かって流体が流れる吸着成形体を作製する場合、図１に示すような円柱の底面に多孔壁面４を設けた成形型１を用いて、スラリー供給口２からスラリーを供給し、水を排水口３から抜くと、活性炭素繊維は底面と平行に積層されるため、流体流れ方向に対する活性炭素繊維の繊維軸方向の角度が直角の吸着成形体ができ、図２に示すような円柱の外周面に多孔壁面８を設けた成形型５を用いて、スラリー供給口６からスラリーを供給し、水を排水口７から抜くと、活性炭素繊維は外周とほぼ平行に積層されるため、流体流れ方向に対する活性炭素繊維の繊維軸方向の角度がランダムな吸着成形体ができる。
【００１５】
吸着成形体は吸水時に吸着成形体を構成する活性炭素繊維が積層されている方向、つまり活性炭素繊維軸と直角方向への膨張がその他の方向への膨張に比べ大きい。従って、活性炭素繊維の繊維軸が流体流れ方向に対してランダムに配向している構造の吸着成形体では、より良好なシール効果が得られるので、好ましい。
【００１６】
本発明で、フィブリル化繊維とは枝状に多数分岐したフィブリル（数ｎｍ〜数μｍの太さを有する微細な繊維状組織）を有する繊維長１〜１０ｍｍ程度の繊維であり、その外部比表面積は１ｍ²／ｇ以上、好ましくは２ｍ²／ｇ以上、さらに好ましくは５ｍ²／ｇ以上である。フィブリル化繊維の外部比表面積は、該フィブリル化繊維のフィブリル化の状態を表しており、上記範囲未満ではフィブリル化繊維のフィブリル化が不十分で、吸着成形体を構成する活性炭素繊維同士を絡み合わせて十分に結合することができないのである。フィブリル化繊維の外部比表面積は、該フィブリル化繊維をシート状に積層したパッドを作製し、該パッドの水の透過速度を測り、Ｋｏｚｅｎｙ−Ｃａｒｍａｎの式とｄ’Ａｒｃｙの式を適用したＲｏｂｅｒｔｓｏｎ−Ｍａｓｏｎの方法から計算した。
【００１７】
フィブリル化繊維としては、重合析出法、フラッシュ紡糸法、フィブリッド法等で作られたアラミド系、ポリビニルアルコール系等の非叩解型のものや木材パルプやポリアクリロニトリル繊維を叩解してフィブリル化した叩解型のものがあり、これらの単独あるいは混合したものが使用できる。なかでも、外部比表面積を大きくできることから、叩解型のものが好ましいが、保水度を１５０％以上有することが必須である。また、木材パルプ等の天然のフィブリル化繊維は長期間湿潤状態で放置したりすると腐敗を生じ、バインダーとしての機能を果たさなくなる可能性があるため、吸着成形体に含有される全フィブリル化繊維に対する合成樹脂から成るフィブリル化繊維の割合が５０重量％以上であることが好ましい。
【００１８】
本発明における吸着成形体は、活性炭素繊維同士がフィブリル化繊維により絡み合って結合されており、フィブリル化繊維の含有率が少ないと実用に耐えうる強度を持ち、また、吸水により膨張する吸着成形体が得られない。従って、実用に耐えうる強度を持ち、吸水により膨張する吸着成形体を得るためにはフィブリル化繊維の含有率を１〜４０重量％、好ましくは３〜３０重量％、さらに好ましくは５〜２０重量％にする。この範囲未満では、吸着成形体の強度及び吸水による膨張が十分ではなく、この範囲を超えると、吸着成形体の流体通過抵抗が大きくなったり、前述したように均質な吸着成形体が得られないという問題が生じるのである。
【００１９】
活性炭素繊維は残留塩素分解除去や低分子量物質の吸着除去性能には優れるが、高分子量物質等はあまり効果的に除去できない。そこで、本発明における吸着成形体には、活性炭素繊維では発現できない機能を付加するために粒状活性炭、粉末活性炭、抗菌活性炭、イオン交換樹脂、ゼオライト等を添加することもできる。以下に実施例にて本発明をさらに詳しく説明する。
【００２０】
【実施例】
実施例に基づき本発明を詳述するが、本発明はこれら実施例に限定されるものではない。
【００２１】
〔実施例１〕
平均繊維径１８μｍ、繊維長１．５ｍｍ、比表面積１４５０ｍ²／ｇのセルロース系活性炭素繊維９５重量％とフィブリル化繊維として叩解処理によりフィブリル化した繊維長３．０ｍｍ、外部比表面積７．２ｍ²／ｇ、保水度２４６％のフィブリル化アクリル繊維５重量％を水に分散してミキサーで混合し均一なスラリーを調整し、図１に示す成形型を用いて排水口から吸引しながらスラリー供給口に流し込み、脱水、脱型、乾燥して円柱形状の吸着成形体を作製した。該吸着成形体の直径は４０．０ｍｍ、高さは４０．５ｍｍ、嵩密度０．１７ｇ／ｃｃであった。該吸着成形体を水中に３０秒浸漬後取り出し、直径及び高さを測定し、膨張率をそれぞれ求めたところ、直径膨張率は０．７８％、高さ膨張率は１．２４％であった。なお、吸着成形体の直径及び高さはレーザ寸法測定器（キーエンス製ＬＳ）を使用して非接触で測定した。
【００２２】
乾燥した状態で上記の吸着成形体を内径４０．２ｍｍの容器に装填し、簡易浄水器を作製し、成形体の上面から底面に向かって残留塩素濃度を２ｐｐｍに調整した水を流量３Ｌ／分で通水し、通水開始３０秒後に圧力損失と浄水器出口の水の残留塩素濃度を測定したところ、圧力損失は１．８ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。なお、残留塩素濃度は多項目迅速水質分析計（ハック社製ＤＲ／２０００）を用いて測定した。
【００２３】
さらに、上記簡易浄水器を、中に装填された吸着成形体が常に湿潤状態を保つように室温で６ヶ月間放置した後、上記と同じ試験を行ったところ、圧力損失は１．８ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００２４】
〔実施例２〕
平均繊維径１８μｍ、繊維長１．５ｍｍ、比表面積１４５０ｍ²／ｇのセルロース系活性炭素繊維９５重量％とフィブリル化繊維として叩解処理によりフィブリル化した繊維長３．０ｍｍ、外部比表面積７．２ｍ²／ｇ、保水度２４６％のフィブリル化アクリル繊維５重量％を水に分散してミキサーで混合し均一なスラリーを調整し、図２に示す成形型を用いて排水口から吸引しながらスラリー供給口に流し込み、脱水、脱型、乾燥して円柱形状の吸着成形体を作製した。該吸着成形体の直径は４０．０ｍｍ、高さは４０．２ｍｍ、嵩密度０．１７ｇ／ｃｃであった。該吸着成形体を実施例１と同様に水中に３０秒浸漬し、膨張率を求めたところ、直径膨張率は１．１２％、高さ膨張率は０．５１％であった。
【００２５】
乾燥した状態で該吸着成形体を内径４０．２ｍｍの容器に装填し、実施例１と同様に簡易浄水器を作製し、実施例１と同様の試験を行ったところ、圧力損失は１．５ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００２６】
さらに、上記簡易浄水器を、実施例１と同様に６ヶ月間放置した後、上記と同じ試験を行ったところ、圧力損失は１．５ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００２７】
〔実施例３〕
平均繊維径１８μｍ、繊維長１．５ｍｍ、比表面積１４５０ｍ²／ｇのセルロース系活性炭素繊維７０重量％、平均粒子径１９μｍの粉末活性炭２０重量％とフィブリル化繊維として外部比表面積４．０ｍ²／ｇ、保水度１８７％のフィブリル化アラミド繊維１０重量％を水に分散してミキサーで混合し均一なスラリーを調整し、図２に示す成形型を用いて排水口から吸引しながらスラリー供給口に流し込み、脱水、脱型、乾燥して円柱形状の吸着成形体を作製した。該吸着成形体の直径は４０．０ｍｍ、高さは４０．２ｍｍ、嵩密度０．１６ｇ／ｃｃであった。該吸着成形体を実施例１と同様に水中に３０秒浸漬し、膨張率を求めたところ、直径膨張率は１．１４％、高さ膨張率は０．５７％であった。
【００２８】
乾燥した状態で該吸着成形体を内径４０．２ｍｍの容器に装填し、実施例１と同様に簡易浄水器を作製し、実施例１と同様の試験を行ったところ、圧力損失は１．６ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００２９】
さらに、上記簡易浄水器を、実施例１と同様に６ヶ月間放置した後、上記と同じ試験を行ったところ、圧力損失は１．６ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００３０】
〔実施例４〕
平均繊維径１８μｍ、繊維長１．５ｍｍ、比表面積１４５０ｍ²／ｇのセルロース系活性炭素繊維９５重量％とフィブリル化繊維として叩解処理によりフィブリル化した繊維長３．０ｍｍ、外部比表面積７．２ｍ²／ｇ、保水度２４６％のフィブリル化アクリル繊維３重量％と外部比表面積５．２ｍ²／ｇ、保水度２０５％の木材パルプ２重量％を水に分散してミキサーで混合し均一なスラリーを調整し、図２に示す成形型を用いて排水口から吸引しながらスラリー供給口に流し込み、脱水、脱型、乾燥して円柱形状の吸着成形体を作製した。該吸着成形体の直径は４０．０ｍｍ、高さは４０．２ｍｍ、嵩密度０．１７ｇ／ｃｃであった。該吸着成形体を実施例１と同様に水中に３０秒浸漬し、膨張率を求めたところ、直径膨張率は１．０９％、高さ膨張率は０．５０％であった。
【００３１】
乾燥した状態で該吸着成形体を内径４０．２ｍｍの容器に装填し、実施例１と同様に簡易浄水器を作製し、実施例１と同様の試験を行ったところ、圧力損失は１．５ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００３２】
さらに、上記簡易浄水器を、実施例１と同様に６ヶ月間放置した後、上記と同じ試験を行ったところ、圧力損失は１．７ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００３３】
〔実施例５〕
平均繊維径１８μｍ、繊維長１．５ｍｍ、比表面積１４５０ｍ²／ｇのセルロース系活性炭素繊維９５重量％とフィブリル化繊維として外部比表面積５．２ｍ²／ｇ、保水度２０５％の木材パルプ５重量％を水に分散してミキサーで混合し均一なスラリーを調整し、図２に示す成形型を用いて排水口から吸引しながらスラリー供給口に流し込み、脱水、脱型、乾燥して円柱形状の吸着成形体を作製した。該吸着成形体の直径は４０．０ｍｍ、高さは４０．２ｍｍ、嵩密度０．１７ｇ／ｃｃであった。該吸着成形体を実施例１と同様に水中に３０秒浸漬し、膨張率を求めたところ、直径膨張率は１．０９％、高さ膨張率は０．５０％であった。
【００３４】
乾燥した状態で該吸着成形体を内径４０．２ｍｍの容器に装填し、実施例１と同様に簡易浄水器を作製し、実施例１と同様の試験を行ったところ、圧力損失は１．５ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００３５】
さらに、上記簡易浄水器を、実施例１と同様に６ヶ月間放置した後、上記と同じ試験を行ったところ、圧力損失は２．４ｋｇｆ／ｃｍ²、残留塩素は検出されなかった。
【００３６】
〔比較例１〕
平均繊維径１８μｍ、繊維長１．５ｍｍ、比表面積１４５０ｍ²／ｇのセルロース系活性炭素繊維９０重量％と繊維長１．６ｍｍ、外部比表面積１．７４ｍ²／ｇ、保水度７１％のフィブリル化ポリエチレン繊維１０重量％を水に分散してミキサーで混合し均一なスラリーを調整し、図１に示す成形型を用いて排水口から吸引しながらスラリー供給口に流し込み、脱水、脱型、乾燥して円柱形状の吸着成形体を作製した。該吸着成形体の直径は４０．０ｍｍ、高さは４０．４ｍｍ、嵩密度０．１６ｇ／ｃｃであった。該吸着成形体を実施例１と同様に水中に３０秒浸漬し、膨張率を求めたところ、直径膨張率は０．０５％、高さ膨張率は０．１４％であった。
【００３７】
乾燥した状態で該吸着成形体を内径４０．２ｍｍの容器に装填し、実施例１と同様に簡易浄水器を作製し、実施例１と同様の試験を行ったところ、圧力損失は１．５ｋｇｆ／ｃｍ²、残留塩素濃度は０．３８ｐｐｍであった。
【００３８】
〔比較例２〕
平均繊維径１８μｍ、繊維長１．５ｍｍ、比表面積１４５０ｍ²／ｇのセルロース系活性炭素繊維９０重量％と繊維長１．６ｍｍ、外部比表面積１．７４ｍ²／ｇ、保水度７１％のフィブリル化ポリエチレン繊維１０重量％を水に分散してミキサーで混合し均一なスラリーを調整し、図２に示す成形型を用いて排水口から吸引しながらスラリー供給口に流し込み、脱水、脱型、乾燥して円柱形状の吸着成形体を作製した。該吸着成形体の直径は４０．０ｍｍ、高さは４０．２ｍｍ、嵩密度０．１６ｇ／ｃｃであった。該吸着成形体を実施例１と同様に水中に３０秒浸漬し、膨張率を求めたところ、直径膨張率は０．１８％、高さ膨張率は０．０６％であった。
【００３９】
乾燥した状態で該吸着成形体を内径４０．２ｍｍの容器に装填し、実施例１と同様に簡易浄水器を作製し、実施例１と同様の試験を行ったところ、圧力損失は１．３ｋｇｆ／ｃｍ²、残留塩素濃度は０．２４ｐｐｍであった。
【００４０】
比較例１、２は保水度が小さいフィブリル化繊維を使用して成形した吸着成形体であるが、吸水時の吸着成形体の膨張率が小さいため、成形体と容器の間の間隙でショートパスを生じる。
【００４１】
比較例に対し、保水度が大きいフィブリル化繊維を使用して作製した実施例は、いずれも吸水時の吸着成形体の膨張率が大きいため、吸着成形体と容器が密着し、ショートパスを起こさない。さらに、吸着成形体に含有される全フィブリル化繊維に対する合成樹脂から成るフィブリル化繊維の割合が５０重量％以上である実施例１〜４では、長期間の放置後も圧力損失の上昇が見られず、フィブリル化繊維のバインダーとしての機能が失われない。
【発明の効果】
以上記載の通り、本発明は、容器に装填して通水したときのシール性が良く、ショートパスを起こさない吸着成形体を提供できる。
【図面の簡単な説明】
【図１】吸着成形体の製法を示す概略図。
【図２】吸着成形体の製法を示す概略図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an adsorbent molded body molded into a fixed shape. More specifically, the present invention is suitable for liquid phase, particularly for water purification, and has a good sealing property when water is loaded in a container such as a plastic case. The present invention relates to an adsorption molded body that does not cause a short pass.
[0002]
[Prior art]
Activated carbon fiber has a large outer surface area, and when used for water purification, it has a feature that is superior in the decomposition and removal performance of residual chlorine compared to granular activated carbon because of its large contact area with water. In many cases, the molded body is formed into a fixed shape with a binder and loaded into a plastic container or the like.
[0003]
For the above-mentioned molded body, a fibrous or powdery heat-meltable synthetic resin is used as a binder, and the heat-meltable synthetic resin is heat-melted and integrally molded. For molded products that are bonded by hot-melting synthetic resin, there is a problem that when a small gap is formed between the molded product and the container when it is loaded into a plastic container, a short path occurs when water is passed. was there.
[0004]
[Problems to be solved by the invention]
In view of the above points, the present invention is to provide an adsorbent molded body that has good sealing properties when loaded in a plastic container or the like and allows water to pass therethrough and does not cause a short pass.
[0005]
[Means for Solving the Problems]
The inventors of the present invention have made extensive studies on a method for preventing the short pass by improving the sealing property when water is passed through by placing an integrally formed adsorption molded body containing activated carbon fibers and a binder into a plastic container or the like. As a result, by using a fibrillated fiber having a water retention of 150% or more as a binder, and making an adsorption molded body having a large expansion at the time of water absorption, the adsorption molded body absorbs water at the time of water passage and expands to adhere to the container, The present inventors have found that a short path can be prevented and have reached the present invention.
[0006]
The present invention is an integrally molded article including activated carbon fibers and fibrillated fibers having a water retention of 150% or more, and has a molded article expansion coefficient in the direction perpendicular to the fluid flow direction during water passage of 0. The present invention relates to an adsorption molded body characterized by being 5 to 5%.
[0007]
In the present invention, the degree of water retention represents the degree of swelling of the fibrillated fiber used as a binder. In a centrifugal dehydrator with a rotating radius of 10 cm after the sample was completely immersed in water (WO) and the sample was sufficiently immersed in water. The weight (W) when dehydrating for 5 minutes at a rotational speed of 300 rpm was measured and determined by the following formula.
Water retention (%) = {(W-WO) / WO} × 100
[0008]
It is important that the water retention of the fibrillated fiber is 150% or more, preferably 200% or more. When a fibrillated fiber having such a water retention degree is used as a binder, an adsorption molded body that expands when water is absorbed can be obtained.
[0009]
In the present invention, the expansion ratio of the molded body represents a change in the dimensions of the adsorption molded body when water is absorbed, and the larger the value, the higher the sealing performance when the adsorption molded body is loaded into the container and water is passed through. It can be said that the dimension (DO) at the time of absolutely dry of the adsorption molded body and the dimension (D) after being immersed in water for 30 seconds are measured by the following formula.
Expansion rate (%) = {(D-DO) / DO} × 100
[0010]
The dimensions of the adsorption molded body obtained by the above method in the direction perpendicular to the fluid flow direction (for example, when a fluid flows from the top surface to the bottom surface of a cylindrical adsorption molded body, the diameter of the adsorption molded body It is an essential requirement of the present invention that the expansion coefficient at the time of water absorption is 0.5 to 5%. If it is less than this range, expansion | swelling at the time of water absorption of an adsorption molded object is small, and sufficient sealing effect is not acquired. On the other hand, if it exceeds this range, the following problems occur. That is, the adsorption molded body of the present invention, as will be described later, is obtained by dispersing activated carbon fibers and fibrillated fibers in water as a uniform slurry, and sucking or pressing the slurry into a molding die from the molding die. It can be produced by a so-called wet molding method that drains water, dehydrates, demolds, and dries, but in the case of an adsorbent molded body whose expansion coefficient during water absorption exceeds this range, shrinkage occurs unevenly during the drying process during production, A homogeneous adsorption molded body cannot be obtained.
[0011]
In the present invention, activated carbon fibers having an average fiber diameter of 5 to 50 μm, a fiber length of 0.5 to 10 mm, and a specific surface area of 500 to 2000 m ² / g can be used. Moreover, it is not limited about the raw material, Any of cellulose type, a polyacrylonitrile type, a phenol resin type, a pitch type etc. may be sufficient. Moreover, the content rate of activated carbon fiber can be set in the range of 50 to 99 weight% according to the desired adsorption | suction performance.
[0012]
In the present invention, the bulk density of the adsorption molded body is 0.1 to 0.3 g / cc, preferably 0.12 to 0.25 g / cc, and more preferably 0.15 to 0.2 g / cc. If it is less than this range, the strength of the adsorption molded body is not sufficient, and if it exceeds this range, the pressure loss of the adsorption molded body increases. The bulk density is determined by measuring the absolute dry weight and volume of the adsorbed molded body and dividing the absolute dry weight by the volume.
[0013]
In the present invention, the integrally formed adsorption molded body is one in which activated carbon fibers and fibrillated fibers are three-dimensionally organized into a predetermined shape. Then, the fibrillated fibers are dispersed in water as a uniform slurry, and the slurry is sucked or poured into a predetermined shape mold having a porous wall through which water can permeate to remove water from the mold. It can be carried out by dehydration, demolding and drying. In that case, the orientation of the activated carbon fibers constituting the adsorption molded body can be controlled by the arrangement of the porous wall surfaces, and the angle of the activated carbon fibers in the fiber axis direction with respect to the fluid flow direction can be made perpendicular or random. In addition, in order to add a function that cannot be expressed with activated carbon fiber, powdered activated carbon, granular activated carbon, antibacterial activated carbon, zeolite, etc. can be added to the slurry, and further, a flocculant, additive, etc. are added to the slurry as necessary. It can also be added.
[0014]
More specifically, the orientation of the activated carbon fibers will be described in detail. For example, in the case of producing an adsorption molded body in which a fluid flows in a cylindrical shape from the upper surface to the bottom surface, molding in which a porous wall surface 4 is provided on the bottom surface of the cylinder as shown in FIG. When the slurry is supplied from the slurry supply port 2 using the mold 1 and the water is extracted from the drain port 3, the activated carbon fibers are stacked in parallel with the bottom surface. An adsorption molded body having a right angle is formed, and a slurry is supplied from a slurry supply port 6 and water is discharged from a drain port 7 using a molding die 5 in which a porous wall surface 8 is provided on the outer peripheral surface of a cylinder as shown in FIG. When extracted, the activated carbon fibers are laminated almost parallel to the outer periphery, so that an adsorption molded body in which the angle of the activated carbon fibers in the fiber axis direction with respect to the fluid flow direction is random can be obtained.
[0015]
The adsorption molded body has a larger expansion in the direction in which the activated carbon fibers constituting the adsorption molded body are laminated at the time of water absorption, that is, the expansion in the direction perpendicular to the activated carbon fiber axis compared to the expansion in other directions. Therefore, an adsorption molded body having a structure in which the fiber axes of the activated carbon fibers are randomly oriented with respect to the fluid flow direction is preferable because a better sealing effect can be obtained.
[0016]
In the present invention, a fibrillated fiber is a fiber having a fiber length of about 1 to 10 mm having fibrils (a fine fibrous structure having a thickness of several nm to several μm) branched in a branch shape, and its external specific surface area. Is 1 m ² / g or more, preferably 2 m ² / g or more, more preferably 5 m ² / g or more. The external specific surface area of the fibrillated fiber represents the state of fibrillation of the fibrillated fiber. If the fibrillated fiber is less than the above range, the fibrillated fiber is insufficiently fibrillated and entangles the activated carbon fibers constituting the adsorption molded body. They cannot be combined together. The external specific surface area of the fibrillated fiber was determined by preparing a pad in which the fibrillated fiber was laminated in a sheet shape, measuring the water permeation rate of the pad, and applying Robertson-- applying the Kozeny-Carman equation and the d'Arcy equation. Calculated from Mason's method.
[0017]
As the fibrillated fibers, non-beating type such as aramid type and polyvinyl alcohol type made by polymerization precipitation method, flash spinning method, fibrid method, etc., and beating type obtained by beating wood pulp and polyacrylonitrile fiber These can be used alone or in combination. Among these, a beating type is preferable because the external specific surface area can be increased, but it is essential to have a water retention of 150% or more. In addition, natural fibrillated fibers such as wood pulp may rot when left in a wet state for a long period of time, and may not function as a binder. The proportion of fibrillated fibers made of synthetic resin is preferably 50% by weight or more.
[0018]
The adsorption molded body in the present invention is an adsorption molded body in which activated carbon fibers are entangled and bonded with each other by fibrillated fibers, has a strength that can withstand practical use when the content of fibrillated fibers is small, and expands by water absorption. Cannot be obtained. Therefore, in order to obtain an adsorbent molded body having a strength that can be practically used and expands by absorbing water, the content of the fibrillated fiber is 1 to 40% by weight, preferably 3 to 30% by weight, more preferably 5 to 20% by weight. %. If it is less than this range, the strength of the adsorption molded body and the expansion due to water absorption are not sufficient, and if it exceeds this range, the fluid passage resistance of the adsorption molded body is increased, or a homogeneous adsorption molded body cannot be obtained as described above. The problem arises.
[0019]
Activated carbon fibers are excellent in residual chlorine decomposition removal and adsorption removal performance of low molecular weight substances, but high molecular weight substances cannot be removed very effectively. Therefore, granular activated carbon, powdered activated carbon, antibacterial activated carbon, ion exchange resin, zeolite, and the like can be added to the adsorption molded body of the present invention in order to add a function that cannot be expressed with activated carbon fibers. Hereinafter, the present invention will be described in more detail with reference to examples.
[0020]
【Example】
The present invention will be described in detail based on examples, but the present invention is not limited to these examples.
[0021]
[Example 1]
95% by weight of cellulosic activated carbon fiber having an average fiber diameter of 18 μm, fiber length of 1.5 mm, specific surface area of 1450 m ² / g, fiber length of 3.0 mm fibrillated by beating as a fibrillated fiber, external specific surface area of 7.2 m ² / G, 5% by weight of fibrillated acrylic fiber with a water retention of 246% is dispersed in water and mixed with a mixer to prepare a uniform slurry, and the slurry supply port is sucked from the drain port using the mold shown in FIG. Then, dehydration, demolding and drying were carried out to produce a cylindrical adsorption molded body. The adsorption molded body had a diameter of 40.0 mm, a height of 40.5 mm, and a bulk density of 0.17 g / cc. The adsorption molded body was immersed in water for 30 seconds and then taken out. The diameter and the height were measured and the expansion coefficient was obtained. The expansion coefficient was 0.78% and the expansion coefficient was 1.24%. . In addition, the diameter and height of the adsorption molded body were measured in a non-contact manner using a laser dimension measuring device (LS made by Keyence).
[0022]
In a dried state, the adsorption molded body is loaded into a container having an inner diameter of 40.2 mm, a simple water purifier is produced, and water whose residual chlorine concentration is adjusted to 2 ppm from the upper surface to the bottom surface of the molded body is flowed at 3 L / min. When the pressure loss and the residual chlorine concentration at the water purifier outlet were measured 30 seconds after the start of water flow, the pressure loss was 1.8 kgf / cm ² and no residual chlorine was detected. The residual chlorine concentration was measured using a multi-item rapid water quality analyzer (DR / 2000 manufactured by Hack).
[0023]
Further, after the simple water purifier was left at room temperature for 6 months so that the adsorption molded body loaded therein was always kept in a wet state, the same test as described above was performed. As a result, the pressure loss was 1.8 kgf / cm. ^2. Residual chlorine was not detected.
[0024]
[Example 2]
95% by weight of cellulosic activated carbon fiber having an average fiber diameter of 18 μm, fiber length of 1.5 mm, specific surface area of 1450 m ² / g, fiber length of 3.0 mm fibrillated by beating as a fibrillated fiber, external specific surface area of 7.2 m ² / G, 5% by weight of fibrillated acrylic fiber having a water retention of 246% is dispersed in water and mixed with a mixer to prepare a uniform slurry, and the slurry supply port is sucked from the drain port using the mold shown in FIG. Then, dehydration, demolding and drying were carried out to produce a cylindrical adsorption molded body. The adsorption molded body had a diameter of 40.0 mm, a height of 40.2 mm, and a bulk density of 0.17 g / cc. The adsorption molded body was immersed in water for 30 seconds in the same manner as in Example 1, and the expansion coefficient was determined. The diameter expansion coefficient was 1.12% and the height expansion coefficient was 0.51%.
[0025]
When the adsorption molded body was loaded in a container having an inner diameter of 40.2 mm in a dried state, a simple water purifier was produced in the same manner as in Example 1, and the same test as in Example 1 was performed. As a result, the pressure loss was 1.5 kgf. / Cm ² , residual chlorine was not detected.
[0026]
Further, after the simple water purifier was allowed to stand for 6 months in the same manner as in Example 1, the same test was performed. As a result, the pressure loss was 1.5 kgf / cm ² and no residual chlorine was detected.
[0027]
Example 3
Cellulose activated carbon fiber with an average fiber diameter of 18 μm, fiber length of 1.5 mm, specific surface area of 1450 m ² / g, 70% by weight of powdered activated carbon with an average particle diameter of 19 μm and an external specific surface area of 4.0 m ² / g. Disperse 10% by weight of fibrillated aramid fiber having a water retention of 187% in water and mix with a mixer to prepare a uniform slurry, and use the mold shown in FIG. Casting, dehydration, demolding, and drying were performed to produce a cylindrical adsorption molded body. The adsorption molded body had a diameter of 40.0 mm, a height of 40.2 mm, and a bulk density of 0.16 g / cc. The adsorption molded body was immersed in water for 30 seconds in the same manner as in Example 1, and the expansion coefficient was determined. The diameter expansion coefficient was 1.14% and the height expansion coefficient was 0.57%.
[0028]
The adsorbed molded body was loaded in a container having an inner diameter of 40.2 mm in a dried state, and a simple water purifier was produced in the same manner as in Example 1. When a test similar to that in Example 1 was performed, the pressure loss was 1.6 kgf. / Cm ² , residual chlorine was not detected.
[0029]
Further, after the simple water purifier was allowed to stand for 6 months in the same manner as in Example 1, the same test as described above was performed. As a result, the pressure loss was 1.6 kgf / cm ² and no residual chlorine was detected.
[0030]
Example 4
95% by weight of cellulosic activated carbon fiber having an average fiber diameter of 18 μm, fiber length of 1.5 mm, specific surface area of 1450 m ² / g, fiber length of 3.0 mm fibrillated by beating as a fibrillated fiber, external specific surface area of 7.2 m ² / G, 3% by weight of fibrillated acrylic fiber with a water retention of 246% and 2% by weight of wood pulp with an external specific surface area of 5.2 m ² / g and a water retention of 205% are dispersed in water and mixed with a mixer to form a uniform slurry. It adjusted, poured into the slurry supply port, attracting | sucking from a drain port using the shaping | molding die shown in FIG. 2, and spin-dry | dehydrated, demolded, and dried and produced the column-shaped adsorption molding. The adsorption molded body had a diameter of 40.0 mm, a height of 40.2 mm, and a bulk density of 0.17 g / cc. The adsorption molded body was immersed in water for 30 seconds in the same manner as in Example 1, and the expansion coefficient was determined. The diameter expansion coefficient was 1.09% and the height expansion coefficient was 0.50%.
[0031]
When the adsorption molded body was loaded in a container having an inner diameter of 40.2 mm in a dried state, a simple water purifier was produced in the same manner as in Example 1, and the same test as in Example 1 was performed. As a result, the pressure loss was 1.5 kgf. / Cm ² , residual chlorine was not detected.
[0032]
Further, after the simple water purifier was allowed to stand for 6 months in the same manner as in Example 1, the same test as described above was performed. As a result, the pressure loss was 1.7 kgf / cm ² and no residual chlorine was detected.
[0033]
Example 5
The average fiber diameter of 18 [mu] m, fiber length 1.5 mm, an external specific surface area as cellulosic activated carbon fiber 95% by weight fibrillated fibers having a specific surface area of ^{^{1450m 2 / g 5.2m 2 / g}} , a water retention value 205% wood pulp 5 wt % Is dispersed in water and mixed with a mixer to prepare a uniform slurry, which is poured into the slurry supply port while sucking from the drainage port using the mold shown in FIG. An adsorption molded body was produced. The adsorption molded body had a diameter of 40.0 mm, a height of 40.2 mm, and a bulk density of 0.17 g / cc. The adsorption molded body was immersed in water for 30 seconds in the same manner as in Example 1, and the expansion coefficient was determined. The diameter expansion coefficient was 1.09% and the height expansion coefficient was 0.50%.
[0034]
When the adsorption molded body was loaded in a container having an inner diameter of 40.2 mm in a dried state, a simple water purifier was produced in the same manner as in Example 1, and the same test as in Example 1 was performed. As a result, the pressure loss was 1.5 kgf. / Cm ² , residual chlorine was not detected.
[0035]
Further, after the simple water purifier was allowed to stand for 6 months in the same manner as in Example 1, the same test as described above was performed. As a result, the pressure loss was 2.4 kgf / cm ² and no residual chlorine was detected.
[0036]
[Comparative Example 1]
The average fiber diameter of 18 [mu] m, fiber length 1.5 mm, 90 wt% cellulosic activated carbon fiber having a specific surface area of 1450 m ² / g and a fiber length of 1.6 mm, an external specific surface area 1.74m ² / g, a water retention value of 71% fibrillated Disperse 10% by weight of polyethylene fiber in water and mix with a mixer to prepare a uniform slurry. Pour it into the slurry supply port while sucking it from the drainage port using the mold shown in FIG. 1, dewatering, demolding and drying. Thus, a cylindrical adsorption molded body was produced. The adsorption molded body had a diameter of 40.0 mm, a height of 40.4 mm, and a bulk density of 0.16 g / cc. The adsorption molded body was immersed in water for 30 seconds in the same manner as in Example 1, and the expansion coefficient was determined. As a result, the diameter expansion coefficient was 0.05%, and the height expansion coefficient was 0.14%.
[0037]
When the adsorption molded body was loaded in a container having an inner diameter of 40.2 mm in a dried state, a simple water purifier was produced in the same manner as in Example 1, and the same test as in Example 1 was performed. As a result, the pressure loss was 1.5 kgf. / Cm ² and the residual chlorine concentration was 0.38 ppm.
[0038]
[Comparative Example 2]
The average fiber diameter of 18 [mu] m, fiber length 1.5 mm, 90 wt% cellulosic activated carbon fiber having a specific surface area of 1450 m ² / g and a fiber length of 1.6 mm, an external specific surface area 1.74m ² / g, a water retention value of 71% fibrillated Disperse 10% by weight of polyethylene fiber in water and mix with a mixer to prepare a uniform slurry. Pour it into the slurry supply port while sucking it from the drainage port using the mold shown in Fig. 2, dehydrating, demolding and drying. Thus, a cylindrical adsorption molded body was produced. The adsorption molded body had a diameter of 40.0 mm, a height of 40.2 mm, and a bulk density of 0.16 g / cc. The adsorption molded body was immersed in water for 30 seconds in the same manner as in Example 1, and the expansion coefficient was determined. As a result, the diameter expansion coefficient was 0.18%, and the height expansion coefficient was 0.06%.
[0039]
The adsorbed molded body was loaded in a container having an inner diameter of 40.2 mm in a dried state, a simple water purifier was produced in the same manner as in Example 1, and the same test as in Example 1 was performed. The pressure loss was 1.3 kgf. / Cm ² , and the residual chlorine concentration was 0.24 ppm.
[0040]
Comparative Examples 1 and 2 are adsorption molded articles formed using fibrillated fibers having a low water retention, but because the expansion coefficient of the adsorption molded article at the time of water absorption is small, there is a short path in the gap between the molded article and the container. Produce.
[0041]
In contrast to the comparative example, all of the examples prepared using fibrillated fibers having a high water retention rate have a large expansion coefficient of the adsorption molded body at the time of water absorption, so that the adsorption molded body and the container are in close contact with each other, causing a short pass. Absent. Furthermore, in Examples 1 to 4 in which the ratio of the fibrillated fibers made of a synthetic resin to the total fibrillated fibers contained in the adsorbed molded body is 50% by weight or more, an increase in pressure loss is observed even after standing for a long time. Therefore, the function of the fibrillated fiber as a binder is not lost.
【The invention's effect】
As described above, the present invention can provide an adsorptive molded article that has good sealing properties when loaded into a container and passed through water and does not cause a short pass.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a production method of an adsorption molded body.
FIG. 2 is a schematic view showing a production method of an adsorption molded body.

Claims

A molded body that includes activated carbon fibers and fibrillated fibers having a water retention of 150% or more and is integrally molded, and has a molded body expansion coefficient of 0.5 to 5% in a direction perpendicular to the direction of fluid flow during water flow. A three-dimensionally organized adsorption molded body characterized in that

2. The adsorption molded body according to claim 1, wherein the fiber axis of the activated carbon fiber is randomly oriented with respect to the fluid flow direction.

The adsorptive molded article according to claim 1 or 2, wherein the ratio of the fibrillated fibers made of a synthetic resin to the total fibrillated fibers contained is 50% by weight or more.