JP3724247B2 - Method for purifying hydrogen peroxide water - Google Patents
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- JP3724247B2 JP3724247B2 JP08241299A JP8241299A JP3724247B2 JP 3724247 B2 JP3724247 B2 JP 3724247B2 JP 08241299 A JP08241299 A JP 08241299A JP 8241299 A JP8241299 A JP 8241299A JP 3724247 B2 JP3724247 B2 JP 3724247B2
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Description
【０００１】
【発明の属する技術分野】
本発明は、過酸化水素水の精製方法に関するものである。更に詳しくは、本発明は、過酸化水素水をイオン交換樹脂との接触処理に付すことにより過酸化水素水中の不純物を除去する技術であって、連続運転中に過酸化水素の急激な分解が発生し危険であったり、不純物の除去効果が低下したりするといった長期にわたっての連続運転が困難になるという、工業的実施の観点から極めて不都合な問題を伴わず、よって好成績下に長期に渡っての連続運転が可能であるという特徴を有し、工業的実施の観点から極めて有利な技術を実現し得る過酸化水素水の精製法に関するものである。
【０００２】
【従来の技術】
半導体の製造プロセスにおいて、ウェハーの洗浄液の一成分として過酸化水素水が用いられる。ここで用いられる過酸化水素水は、高度に清浄で純粋であることが要求される。特に、過酸化水素水中に鉄イオンやアルミニウムイオンといった金属不純物、硝酸塩や硫酸塩等のアニオン不純物等の不純物が存在すると、得られる半導体の信頼性を著しく低下させるといわれている。一方で半導体の信頼性に対する要求水準は、近年一層高度なものとなりつつあり、不純物が極めて低い水準に制御された高純度の過酸化水素水がますます必要とされている。
【０００３】
ところで、過酸化水素水の精製方法として、過酸化水素水をイオン交換樹脂塔に充填されたアニオン交換樹脂やカチオン交換樹脂と接触させ、不純物を除去する方法が知られている。ここで製品充填バランス等の運転上の都合や工場の定期メンテナンス等により数日間あるいはそれ以上の期間、過酸化水素水精製装置の停止を余儀なくされることがある。ところがこういった場合、再度、精製をスタートさせるにあたり、それまで精製に使用してきたイオン交換樹脂は捨てて、新しいイオン交換樹脂を充填するという経済的観点から見るとはなはだ効率の悪いことが行われてきた。これは一度精製に使用した後に再使用されるイオン交換樹脂は新品のイオン交換樹脂と比較すると、劣化が進んでおり、そのため連続運転中に過酸化水素の急激な分解が発生し危険であったり、不純物の除去効果が低下したりするためであった。
【０００４】
【発明が解決しようとする課題】
かかる現状において本発明が解決しようとする課題は、イオン交換樹脂との接触処理に付すことにより過酸化水素水中の不純物を除去する技術であって、連続運転中に過酸化水素の急激な分解が発生し危険であったり、不純物の除去効果が低下したりするといった長期にわたっての連続運転が困難になるという、工業的実施の観点から極めて不都合な問題を伴わず、よって好成績下に長期に渡っての連続運転が可能であるという特徴を有し、工業的実施の観点から極めて有利な技術を実現し得る過酸化水素水の精製法を提供する点に存するものである。
【０００５】
【課題を解決するための手段】
本発明者らは、従来の技術が有する前記の問題について検討した結果、過酸化水素水とイオン交換樹脂が接触する場合、流通状態で接触する場合にはほとんど劣化しないにもかかわらず静置状態で接触する場合にはイオン交換樹脂の劣化が激しいこと、そのため精製終了後も放置しておくとイオン交換樹脂塔内に残存した過酸化水素水が樹脂を劣化させることが判明した。更に、本発明者らは、上記の問題を解消する方法について鋭意検討し、以下説明する本発明に到達したものである。
すなわち、本発明は、イオン交換樹脂充填塔に過酸化水素水を通液することにより過酸化水素水を精製する方法において、過酸化水素水の精製を行った後にイオン交換樹脂量の２０倍以上の水を通水することにより水置換を行ったイオン交換樹脂を再び過酸化水素水の精製に使用することを特徴とする過酸化水素水の精製方法に係るものである。
【０００６】
【発明の実施の形態】
本発明で精製に付される粗過酸化水素水としては、アントラキノン法等により工業的に製造された過酸化水素水を用いることができるが、工業用過酸化水素水を吸着樹脂、キレート樹脂、逆浸透膜等を使用してあらかじめ粗精製した過酸化水素水を用いてもよい。過酸化水素水の濃度については特に制限はないが、通常は１〜７０重量％、好ましくは１〜４０重量％である。
【０００７】
本発明で使用されるイオン交換樹脂としては強酸性カチオン交換樹脂、弱酸性カチオン交換樹脂、強塩基性アニオン交換樹脂、弱塩基性アニオン交換樹脂があげられるが、不純物の除去性の観点から強酸性カチオン交換樹脂、強塩基性アニオン交換樹脂を使用することが好ましい。カチオン交換樹脂は通常Ｎａ型で市販されている樹脂を鉱酸でコンディショニングしてＨ型に調製して用いられるが、Ｈ型で市販されている樹脂を使用してもよい。カチオン交換樹脂の架橋度は低すぎると過酸化水素水と接触したときの劣化が大きいことから中程度以上のものを使用することが望ましく、このような樹脂としては三菱化学社製ダイヤイオンＳＫ１Ｂ、同ＳＫ１ＢＨ、ローム＆ハース社製デュオライトＣ−２０、同Ｃ−２０Ｈ、オルガノ社製アンバーライトＩＲ−１２０Ｂ、同ＩＲ−１２０ＢＨ、ＥＳＧ−Ｋ、ダウ社製モノスフィア６５０Ｃ等があげられる。アニオン交換樹脂は通常Ｃｌ型で市販されており、これを炭酸水素型もしくは炭酸型に変換して用いられるが、ＯＨ型で市販されている樹脂を炭酸水素型もしくは炭酸型に変換して用いたり炭酸水素型で市販されている樹脂をそのまま用いてもよい。カチオン交換樹脂と同様にアニオン交換樹脂の架橋度は低すぎると過酸化水素水と接触したときの劣化が大きいことから中程度以上のものを使用することが望ましく、このような樹脂としては三菱化学社製ダイヤイオンＳＡ−１０Ａ、同ＳＡ−１２Ａ、オルガノ社製アンバーライトＩＲＡ−４０２ＢＬ、ＥＳＧ−Ａ、ローム＆ハース社製デュオライトＡ−１１３、同Ａ−１１３ＯＨ、ダウ社製モノスフィア５５０Ａ等があげられる。
【０００８】
本発明で使用されるイオン交換樹脂は単独で用いてもよいが、カチオン交換樹脂とアニオン交換樹脂と組み合わせたりあるいは混床で使用する方がより高純度の過酸化水素水を得ることができる。またより高度に精製する目的で多段で通液を行ったり、一部を原料側に返送するという循環精製運転をしたり、キレート樹脂、吸着樹脂、逆浸透膜等と組み合わせて精製を行ってもよい。
【０００９】
本発明において、イオン交換樹脂への過酸化水素水の通液速度は、通常はＳＶ（空間速度）で０．１〜１００ｈｏｕｒ-1、好ましくは２〜５０ｈｏｕｒ-1である。液温は分解を抑制するため、３０℃以下が好ましく、より好ましくは１５℃以下である。冷却の方法としては過酸化水素水を多管式熱交換器を通す方法、充填塔自体をジャケットを使用して直接冷却する方法等がある。充填塔、配管は場合によっては断熱材で覆ってもよい。イオン交換樹脂塔での過酸化水素水の通液方向は上昇流で行っても下降流で行ってもよいが、アニオン交換樹脂あるいはアニオン交換樹脂とカチオン交換樹脂の混床で通液を実施する際は、過酸化水素の分解による発泡を少なくするために、圧力をかけるのが一般的である。
【００１０】
本発明で各薬液および超純水の接液部に使用される材質としては低溶出型塩化ビニル樹脂、ＰＦＡ、ＰＴＦＥ等のフッ素樹脂等が使用される。またステンレススチールやカーボンスチールに低溶出型塩化ビニル樹脂、ＰＦＡ、ＰＴＦＥ等のフッ素樹脂をコーティングあるいはライニングしたものも使用できる。
【００１１】
本発明において、過酸化水素水の精製を停止する原因としては先にあげた製品充填バランス等の運転上の都合や工場の定期メンテナンスの他にイオン交換樹脂の破過によるものがあるが、いずれにせよ停止後直ちに水置換操作に移る必要がある。水置換に使用される水は特に制限はないが、純度が高いほうがより好ましく、一般的には超純水とよばれる比抵抗が１７ＭΩ・ｃｍ以上のものが使用される。通水速度はＳＶで１〜５０ｈｏｕｒ-1で行うのが一般的であり、通水量としてはイオン交換樹脂量の２０倍以上（ＢＶ２０）行う必要があり、より好ましくは５０倍以上、さらに好ましくは１００倍以上行うのがよい。通水温度は過酸化水素水の通液と同様、あまり高い温度で実施すると樹脂の分解がすすむので、３０℃以下より好ましくは２０℃以下で実施するのがよい。水置換を実施しない場合は停止期間中に過酸化水素水により樹脂の劣化が促進してしまい樹脂を再使用することができなくなる。過酸化水素水を流通させておく場合よりも静置させておく場合の方が樹脂の劣化の進行が桁違いに大きくなるのである。もしもこの状態でイオン交換樹脂を再使用すると金属やアニオン等の不純物が十分に除去できなかったり、アニオン交換樹脂の場合においては過酸化水素の急激な分解が発生したりして非常に危険である。また水置換を実施した場合でもその量が不十分であると、残存した過酸化水素水が樹脂を劣化させ、同様の結果となる。十分に水置換を行えば、１ヶ月以上放置しておいても樹脂の劣化は進まないので、イオン交換樹脂塔を２系列持ち、樹脂が破過したら交互に切り替えて運転する場合には特に都合がよい。なおキレート樹脂や逆浸透膜を併用して精製を行う場合にはこれらについても同様の処置を行うことが望ましい。
【００１２】
本発明でイオン交換樹脂を再使用する際はイオン交換樹脂は再生して使用することが好ましいが、交換容量に十分余裕がある場合には再生せずにそのまま過酸化水素水を通液してもよい。再生は精製塔と同じ塔で行ってもよいし、別の再生専用の樹脂塔に移送して行ってもよい。カチオン交換樹脂の再生の方法は一般には０．５〜３規定濃度の塩酸水溶液、硫酸水溶液等の鉱酸水溶液を通液後、超純水で水洗することにより行われる。ここで使用される鉱酸水溶液、超純水の純度はできるだけ高純度であることが望ましく、鉱酸水溶液の場合、各金属不純物の濃度が１重量ｐｐｂ以下好ましくは１０重量ｐｐｔ以下のものを用いるとよい。超純水の場合は各金属不純物の濃度が１０重量ｐｐｔ以下好ましくは１重量ｐｐｔ以下のものを用いるとよい。鉱酸による再生量は樹脂量の１倍〜５０倍の量が一般的であるが、樹脂に吸着した不純物の量によっては更に多くしたり少なくしたりしてもよい。超純水による水洗量は樹脂中に残存する不純物イオンが完全になくなるまで行う必要があり、通常はＢＶで１００倍以上、好ましくは２００倍以上行う。
【００１３】
アニオン交換樹脂の再生の方法は一般には０．５〜３規定濃度の水酸化ナトリウム、水酸化カリウム、テトラメチルアンモニウムハイドロオキサイド等のアルカリの水溶液を通液後、超純水で置換し、引き続き０．１〜２規定濃度の炭酸水素ナトリウム、炭酸ナトリウム等の炭酸水素塩もしくは炭酸塩の水溶液を通液し、さらに超純水で水洗することにより行われる。場合によってはアルカリの水溶液を通液する工程を省略したり、アルカリの水溶液を通液する前に塩酸等の鉱酸の水溶液により洗浄する工程を追加してもよい。塩酸等の鉱酸の水溶液を使用する場合はアニオン交換樹脂に残存する炭酸水素基あるいは炭酸基が酸と反応して炭酸ガスが大量に発生するのであらかじめ水酸化ナトリウムや塩化ナトリウム等を通液しＣｌ型やＯＨ型に置換しておくことが望ましい。ここで使用されるアルカリの水溶液、炭酸水素塩もしくは炭酸塩の水溶液、鉱酸の水溶液、超純水の純度もできるだけ高純度であることが望ましく、アルカリの水溶液、炭酸水素塩もしくは炭酸塩の水溶液の場合、各金属不純物の濃度が５重量ｐｐｂ以下好ましくは０．５重量ｐｐｂ以下のものを、鉱酸の水溶液の場合、各金属不純物の濃度が１重量ｐｐｂ以下好ましくは１０重量ｐｐｔ以下のものを、超純水の場合は各金属不純物の濃度が１０重量ｐｐｔ以下好ましくは１重量ｐｐｔ以下のものを用いるとよい。再生量は樹脂量のそれぞれ１倍〜５０倍の量が一般的であるが、樹脂に吸着した不純物の量によっては更に多くしたり少なくしたりしてもよい。超純水による水洗量は樹脂中に残存する不純物イオンが完全になくなるまで行う必要があり、通常はＢＶで５０倍以上、好ましくは１００倍以上行う。
【００１４】
鉱酸水溶液、アルカリの水溶液、炭酸水素塩もしくは炭酸塩の水溶液、超純水の通液温度は樹脂の耐熱温度以下であればよいが、通常は常温以下で行うのがよい。高濃度の鉱酸やアルカリ水溶液を配管上で水で希釈する場合や夏季は、温度が上昇してしまう場合があるので、その時は熱交換器等を使用して冷却してもよい。
【００１５】
再生の終了日から時間の経過があった場合には過酸化水素水の通液直前にイオン交換樹脂の水洗を行うことが好ましい。これは主に浸積水中のイオン交換樹脂から溶出した微量のＴＯＣ成分を取り除くためである。水洗に用いる水は再生で用いられる水と同様のいわゆる超純水を用いるのがよい。水洗量は場合にもよるが、ＢＶで５倍以上、好ましくは２０倍以上行うのがよい。過酸化水素水通液に際しては上記の水洗工程の実施中に過酸化水素水を切り込んでライン混合して徐々に濃度を上げていく方法をとってもよいし、水洗を停止して、いきなり所定濃度の過酸化水素水を通液してもよい。なお水洗の代わりに過酸化水素水による洗浄を行ったり、初期のイオン交換処理された過酸化水素水を捨てたり、原料リサイクルしたりすることでも同様の効果は得られる。
【００１６】
本発明においてイオン交換樹脂の性能劣化の有無を過酸化水素水の通液前に確認する方法は一般的な測定方法を用いればよく、化学的強度については樹脂中の水分（含水度）、総交換容量、中性塩分解容量、弱酸基交換容量、弱塩基交換容量等が、物理的強度については圧縮強度、外観指数（完球率）等が測定される。カチオン交換樹脂についてはこれで十分であるが、アニオン交換樹脂についてはこれらの一般的な測定項目で問題はなくても、実際に過酸化水素水の処理に供した時に過酸化水素の分解が大きい樹脂が存在する。この発熱・分解の有無を判断する方法として本発明者らが実施しているのが以下に示す試験方法である（以下、ジャーテストと呼ぶ）。まず、湿潤状態にある試料樹脂を１００ｍｌ秤取し、ろ布に包み、水を切る。前処理操作として、順に７．５重量％の過酸化水素水１５分間浸漬、３１重量％の過酸化水素水１５分間浸漬、３１重量％の過酸化水素水１０分間浸漬を行う。浸漬の間は上下運動を行う。液から樹脂を取り出し、全量をデュワー瓶等の断熱容器に移送する。移送にはテフロン製のスプーン等の汚染の無いものを使用する。続いて３１重量％の過酸化水素水を１００ｍｌ加え、温度測定を開始する。この時の温度をＴ0（℃）とする。５時間経過後の温度を測定し、この時の温度をＴ5（℃）とする。以上の操作は室温で行われ、試験に供される過酸化水素水としては電子工業用として市販されている過酸化水素水を用いるのが一般的である。液温の上昇速度ΔＴ（℃／ｈｏｕｒ）は下記の式で示される。
ΔＴ＝（Ｔ5−Ｔ0）／５ （℃／ｈｏｕｒ）
この液温の上昇速度ΔＴが２℃／ｈｏｕｒを超えるものを過酸化水素水の精製に使用すると連続運転中に過酸化水素の急激な分解が発生し危険であったり、その結果不純物の除去効果が低下したりするのである。もちろんジャーテストは新品の樹脂の選定にも適用し得る試験方法である。以上述べた試験方法は必ずしも過酸化水素水の精製を行うたびに毎回実施する必要はない。
【００１７】
本発明によれば先にあげた一般的な試験項目およびこのジャーテストにおいても新品とほとんど変わらないイオン交換樹脂を過酸化水素水の精製に供することができ、カチオン交換樹脂の場合１年以上、アニオン交換樹脂の場合６ヶ月以上にわたって、繰り返し使用することが可能となっている。
【００１８】
【実施例】
以下、本発明を実施例及び比較例により説明する。なお金属成分の分析はＩＣＰ−ＭＳ法で、アニオン成分の分析はイオンクロマト法で、全窒素の分析は触媒酸化吸光法で行った。
実施例１
イオン交換樹脂塔に炭酸水素型に調製した三菱化学社製アニオン交換樹脂ＳＡ１０Ａ（ロット７Ｃ１０１）を充填し、別のイオン交換樹脂塔にＨ型に調製したローム＆ハース社製カチオン交換樹脂Ｃ−２０Ｈを充填した。逆浸透膜を使用して粗精製した過酸化水素水をアニオン交換樹脂にＳＶ＝３ｈｏｕｒ-1の速度で上昇流で通液し、続いてカチオン交換樹脂にＳＶ＝４ｈｏｕｒ-1の速度で下降流で通液した。通液は７℃で実施し、２０日間継続した。精製後の過酸化水素水の品質を表１に示す。通液終了後、直ちに超純水をＳＶ＝５ｈｏｕｒ-1の速度で２４時間通液し、水置換を行った。１ヶ月後、再度過酸化水素水の精製を行った。通液は一度目と同条件で行った。なおアニオン交換樹脂は再使用に先立ち、２規定濃度の水酸化ナトリウム水溶液をＳＶ＝５ｈｏｕｒ-1で２時間通液し、水置換してから、２規定濃度の塩酸水溶液をＳＶ＝５ｈｏｕｒ-1で１時間通液し、水置換後、２規定濃度の水酸化ナトリウム水溶液をＳＶ＝５ｈｏｕｒ-1で２時間通液し、水置換後０．７規定濃度の炭酸水素ナトリウム水溶液をＳＶ＝５ｈｏｕｒ-1で２時間通液して炭酸水素型に変換し、最後に超純水をＳＶ＝１０ｈｏｕｒ-1で７２時間通液し洗浄を行った。カチオン交換樹脂は再使用に先立ち、２規定濃度の塩酸水溶液をＳＶ＝５ｈｏｕｒ-1で４時間通液してＨ型に変換し、次に超純水をＳＶ＝５ｈｏｕｒ-1で９２時間通液し、洗浄を行った。また過酸化水素水の精製開始の直前には超純水をＳＶ＝５ｈｏｕｒ-1で１２時間通液し、洗浄を行った。精製後の過酸化水素水の過酸化水素水の品質を表１に示す。またあわせて、再生が終了した後、アニオン交換樹脂の一部を抜き出し、ジャーテストを実施した。
【００１９】
比較例１
一度目の精製終了後の水置換がＳＶ＝５ｈｏｕｒ-1の速度で２時間しか行わなかったこと以外は実施例１と同様のテストを実施した。結果を表１に示す。
【００２０】
実施例２
イオン交換樹脂塔に炭酸水素型に調製した三菱化学社製アニオン交換樹脂ＳＡ１０Ａ（ロット７Ｃ１０１）を充填し、別のイオン交換樹脂塔にＨ型に調製したオルガノ社製カチオン交換樹脂ＥＳＧ−Ｋを充填した。逆浸透膜を使用して粗精製した過酸化水素水をアニオン交換樹脂にＳＶ＝４ｈｏｕｒ-1の速度で上昇流で通液し、続いてカチオン交換樹脂にＳＶ＝４ｈｏｕｒ-1の速度で下降流で通液した。通液は５℃で実施し、１２日間継続した。精製後の過酸化水素水の品質を表２に示す。通液終了後、直ちに超純水をＳＶ＝１０ｈｏｕｒ-1の速度で２時間通液し、水置換を行った。１０日後、再度過酸化水素水の精製を行った。通液は一度目と同条件で行った。なおアニオン交換樹脂は再使用に先立ち、２規定濃度の水酸化ナトリウム水溶液をＳＶ＝５ｈｏｕｒ-1で２時間通液し、水置換後、０．７規定濃度の炭酸水素ナトリウム水溶液をＳＶ＝５ｈｏｕｒ-1で２時間通液して炭酸水素型に変換し、最後に超純水をＳＶ＝１０ｈｏｕｒ-1で２４時間通液し洗浄を行った。カチオン交換樹脂は再使用に先立ち、２規定濃度の塩酸水溶液をＳＶ＝５ｈｏｕｒ-1で６時間通液してＨ型に変換し、次に超純水をＳＶ＝１０ｈｏｕｒ-1で２４時間通液し、洗浄を行った。精製後の過酸化水素水の過酸化水素水の品質を表１に示す。
【００２１】
比較例２
一度目の精製終了後に水置換を行わなかったこと以外は実施例２と同様のテストを実施した。結果を表１に示す。
【００２２】
【表１】
【発明の効果】
以上説明したとおり、本発明により、イオン交換樹脂との接触処理に付すことにより過酸化水素水中の不純物を除去する技術であって、連続運転中に過酸化水素の急激な分解が発生し危険であったり、不純物の除去効果が低下したりするといった長期にわたっての連続運転が困難になるという、工業的実施の観点から極めて不都合な問題を伴わず、よって好成績下に長期に渡っての連続運転が可能であるという特徴を有し、工業的実施の観点から極めて有利な技術を実現し得る過酸化水素水の精製法を提供することができた。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for purifying hydrogen peroxide water. More specifically, the present invention is a technology for removing impurities in hydrogen peroxide water by subjecting the hydrogen peroxide water to contact treatment with an ion exchange resin, and hydrogen peroxide is rapidly decomposed during continuous operation. This is not a very inconvenient problem from the viewpoint of industrial implementation that it is difficult to perform continuous operation over a long period of time, such as being dangerous and reducing the effect of removing impurities. In particular, the present invention relates to a method for purifying hydrogen peroxide water that can realize a technology that is extremely advantageous from the viewpoint of industrial implementation.
[0002]
[Prior art]
In a semiconductor manufacturing process, hydrogen peroxide is used as one component of a wafer cleaning solution. The hydrogen peroxide solution used here is required to be highly clean and pure. In particular, the presence of metal impurities such as iron ions and aluminum ions and anionic impurities such as nitrates and sulfates in hydrogen peroxide water is said to significantly reduce the reliability of the resulting semiconductor. On the other hand, the required level of reliability of semiconductors is becoming more advanced in recent years, and there is an increasing need for high-purity hydrogen peroxide water in which impurities are controlled to a very low level.
[0003]
By the way, as a method for purifying hydrogen peroxide, a method is known in which hydrogen peroxide is brought into contact with an anion exchange resin or cation exchange resin packed in an ion exchange resin tower to remove impurities. Here, the hydrogen peroxide solution purifier may be stopped for a period of several days or longer due to operational reasons such as product filling balance and regular maintenance of the factory. However, in such a case, when starting the purification again, the ion exchange resin that has been used for the purification is discarded and filled with a new ion exchange resin from the economical point of view. I came. This is because ion exchange resins that are reused after being used for purification have deteriorated compared to new ion exchange resins, and as a result, hydrogen peroxide can be rapidly decomposed during continuous operation. This is because the effect of removing impurities decreases.
[0004]
[Problems to be solved by the invention]
Under such circumstances, the problem to be solved by the present invention is a technique for removing impurities in hydrogen peroxide water by subjecting it to a contact treatment with an ion exchange resin, in which hydrogen peroxide is rapidly decomposed during continuous operation. This is not a very inconvenient problem from the viewpoint of industrial implementation that it is difficult to perform continuous operation over a long period of time, such as being dangerous and reducing the effect of removing impurities. Therefore, the present invention is to provide a method for purifying hydrogen peroxide solution, which has the feature that it can be continuously operated and can realize a technique that is extremely advantageous from the viewpoint of industrial implementation.
[0005]
[Means for Solving the Problems]
As a result of studying the above-mentioned problems of the prior art, the present inventors have found that the hydrogen peroxide solution and the ion exchange resin are in contact with each other, and in a stationary state despite being hardly deteriorated when contacting in a flow state. It has been found that the ion exchange resin deteriorates drastically when it comes into contact with the water, so that the hydrogen peroxide solution remaining in the ion exchange resin tower deteriorates the resin if left after the completion of purification. Furthermore, the present inventors diligently studied a method for solving the above-described problems, and reached the present invention described below.
That is, the present invention is a method of purifying hydrogen peroxide solution by passing hydrogen peroxide solution through an ion exchange resin packed tower, and after purifying hydrogen peroxide solution, the amount of ion exchange resin is 20 times or more. The present invention relates to a method for purifying hydrogen peroxide solution, characterized in that the ion exchange resin that has been subjected to water replacement by passing water is used again for purifying hydrogen peroxide solution.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As the crude hydrogen peroxide solution subjected to purification in the present invention, hydrogen peroxide solution industrially produced by an anthraquinone method or the like can be used, but industrial hydrogen peroxide solution is adsorbed resin, chelate resin, Hydrogen peroxide solution roughly purified in advance using a reverse osmosis membrane or the like may be used. Although there is no restriction | limiting in particular about the density | concentration of hydrogen peroxide water, Usually, 1 to 70 weight%, Preferably it is 1 to 40 weight%.
[0007]
Examples of the ion exchange resin used in the present invention include strongly acidic cation exchange resins, weakly acidic cation exchange resins, strongly basic anion exchange resins, and weakly basic anion exchange resins. It is preferable to use a cation exchange resin or a strongly basic anion exchange resin. The cation exchange resin is usually prepared by conditioning a resin commercially available in Na type with a mineral acid to form H type, but a resin marketed in H type may be used. If the degree of cross-linking of the cation exchange resin is too low, it is desirable to use a medium or higher resin since the deterioration when contacted with hydrogen peroxide is large. As such a resin, Diaion SK1B manufactured by Mitsubishi Chemical Corporation, Examples include SK1BH, Rohm & Haas Duolite C-20, C-20H, Organo Amberlite IR-120B, IR-120BH, ESG-K, Dow Monosphere 650C, and the like. Anion exchange resins are usually commercially available in the Cl type, and are used by converting them to a hydrogen carbonate type or a carbonate type, but the resins marketed in the OH type can be used by converting them to a hydrogen carbonate type or a carbonate type. Resin commercially available in the hydrogen carbonate type may be used as it is. As with the cation exchange resin, if the degree of crosslinking of the anion exchange resin is too low, it is desirable to use a medium or higher one because the deterioration upon contact with hydrogen peroxide is large. Diaion SA-10A, SA-12A, Organo Amberlite IRA-402BL, ESG-A, Rohm & Haas Duolite A-113, A-113OH, Dow Monosphere 550A, etc. can give.
[0008]
The ion exchange resin used in the present invention may be used alone, but a higher purity hydrogen peroxide solution can be obtained by combining the cation exchange resin and the anion exchange resin or using them in a mixed bed. In addition, it is possible to perform liquid purification in multiple stages for the purpose of purifying to a higher degree, carry out a circulating purification operation in which a part is returned to the raw material side, or perform purification in combination with chelate resin, adsorption resin, reverse osmosis membrane, etc Good.
[0009]
In the present invention, liquid permeation rate of hydrogen peroxide to the ion-exchange resin, 0.1～100Hour -1 is usually SV (space velocity), preferably 2~50hour -1. In order to suppress decomposition, the liquid temperature is preferably 30 ° C. or lower, more preferably 15 ° C. or lower. As a cooling method, there are a method of passing hydrogen peroxide solution through a multi-tube heat exchanger, a method of directly cooling the packed tower itself using a jacket, and the like. In some cases, the packed tower and the piping may be covered with a heat insulating material. The flow direction of the hydrogen peroxide solution in the ion exchange resin tower may be an upward flow or a downward flow, but the flow is performed in an anion exchange resin or a mixed bed of anion exchange resin and cation exchange resin. At this time, pressure is generally applied to reduce foaming due to decomposition of hydrogen peroxide.
[0010]
In the present invention, low elution vinyl chloride resin, fluorine resin such as PFA, PTFE, or the like is used as the material used for the liquid contact part of each chemical solution and ultrapure water. Further, stainless steel or carbon steel coated with a low-elution vinyl chloride resin, fluorine resin such as PFA, PTFE or the like can be used.
[0011]
In the present invention, the cause of stopping the purification of the hydrogen peroxide solution is due to breakthrough of the ion exchange resin in addition to the operational convenience such as the product filling balance and the periodic maintenance of the factory. In any case, it is necessary to move to the water replacement operation immediately after stopping. The water used for water replacement is not particularly limited, but it is more preferable that the purity is higher. Generally, water having a specific resistance of 17 MΩ · cm or more called ultrapure water is used. The water flow rate is generally 1 to 50 hour -1 in SV, and the water flow amount needs to be 20 times or more (BV20) of the ion exchange resin amount, more preferably 50 times or more, and still more preferably It is better to do it 100 times or more. The water passage temperature is the same as that for hydrogen peroxide solution. If it is carried out at a very high temperature, the resin will be decomposed. Therefore, the water passage temperature is preferably 30 ° C. or lower, more preferably 20 ° C. or lower. If water replacement is not performed, the deterioration of the resin is accelerated by the hydrogen peroxide solution during the stop period, and the resin cannot be reused. In the case where the hydrogen peroxide solution is allowed to stand still, the deterioration of the resin progresses by an order of magnitude. If ion exchange resin is reused in this state, impurities such as metals and anions cannot be removed sufficiently, and in the case of anion exchange resin, hydrogen peroxide is rapidly decomposed, which is very dangerous. . In addition, even when water replacement is performed, if the amount is insufficient, the remaining hydrogen peroxide solution deteriorates the resin, and the same result is obtained. If sufficient water replacement is performed, the resin will not deteriorate even if it is left for more than 1 month. Therefore, it is particularly convenient to operate with two ion exchange resin towers that are alternately switched when the resin breaks through. Is good. In addition, when refine | purifying using a chelate resin and a reverse osmosis membrane together, it is desirable to perform the same treatment also about these.
[0012]
When the ion exchange resin is reused in the present invention, it is preferable to regenerate and use the ion exchange resin. However, when there is a sufficient margin for the exchange capacity, the hydrogen peroxide solution is directly passed without regeneration. Also good. Regeneration may be performed in the same tower as the purification tower, or may be performed by transferring to another resin tower dedicated to regeneration. The method for regenerating the cation exchange resin is generally carried out by passing a mineral acid aqueous solution such as a hydrochloric acid aqueous solution or a sulfuric acid aqueous solution having a concentration of 0.5 to 3 N and washing with ultrapure water. The purity of the mineral acid aqueous solution and ultrapure water used here is desirably as high as possible. In the case of the mineral acid aqueous solution, the concentration of each metal impurity is 1 weight ppb or less, preferably 10 weight ppt or less. Good. In the case of ultrapure water, the concentration of each metal impurity may be 10 weight ppt or less, preferably 1 weight ppt or less. The amount of regeneration with mineral acid is generally 1 to 50 times the amount of resin, but may be increased or decreased depending on the amount of impurities adsorbed on the resin. The amount of washing with ultrapure water needs to be performed until the impurity ions remaining in the resin completely disappear, and is usually 100 times or more, preferably 200 times or more in BV.
[0013]
In general, the anion exchange resin is regenerated by passing an aqueous solution of an alkali such as sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide or the like having a concentration of 0.5 to 3 N, and replacing with ultrapure water. .1 to 2N concentration of sodium hydrogen carbonate, sodium hydrogen carbonate such as sodium carbonate or an aqueous solution of carbonate is passed through and further washed with ultrapure water. In some cases, a step of passing an alkaline aqueous solution may be omitted, or a step of washing with an aqueous solution of a mineral acid such as hydrochloric acid may be added before passing an alkaline aqueous solution. When using an aqueous solution of mineral acid such as hydrochloric acid, hydrogen carbonate groups or carbonate groups remaining in the anion exchange resin react with the acid and a large amount of carbon dioxide gas is generated. It is desirable to substitute it with Cl type or OH type. The alkali aqueous solution, bicarbonate or carbonate aqueous solution, mineral acid aqueous solution, and ultrapure water used here are preferably as pure as possible. The alkali aqueous solution, bicarbonate or carbonate aqueous solution is desirable. When the concentration of each metal impurity is 5 wt ppb or less, preferably 0.5 wt ppb or less, and in the case of an aqueous mineral acid solution, the concentration of each metal impurity is 1 wt ppb or less, preferably 10 wt ppt or less. In the case of ultrapure water, the concentration of each metal impurity may be 10 wt ppt or less, preferably 1 wt ppt or less. The amount of regeneration is generally 1 to 50 times the amount of the resin, but may be further increased or decreased depending on the amount of impurities adsorbed on the resin. The amount of washing with ultrapure water needs to be performed until the impurity ions remaining in the resin are completely eliminated, and is usually 50 times or more, preferably 100 times or more in BV.
[0014]
The passing temperature of the mineral acid aqueous solution, alkaline aqueous solution, bicarbonate or carbonate aqueous solution, and ultrapure water may be any temperature that is not higher than the heat resistance temperature of the resin, but it is usually preferable that the temperature is normal temperature or lower. When a high concentration mineral acid or alkaline aqueous solution is diluted with water on a pipe or in summer, the temperature may increase. At that time, the heat may be cooled using a heat exchanger or the like.
[0015]
When there is a lapse of time from the end date of regeneration, it is preferable to wash the ion exchange resin with water just before passing the hydrogen peroxide solution. This is mainly for removing a small amount of TOC component eluted from the ion exchange resin in the immersion water. As the water used for washing, so-called ultrapure water similar to the water used for regeneration is preferably used. Although the amount of washing depends on the case, it is better to carry out 5 times or more, preferably 20 times or more by BV. When the hydrogen peroxide solution is passed, a method may be used in which the hydrogen peroxide solution is cut and mixed in line during the above water washing step to gradually increase the concentration. Hydrogen peroxide water may be passed. The same effect can be obtained by washing with hydrogen peroxide solution instead of washing with water, discarding the hydrogen peroxide solution subjected to the initial ion exchange treatment, or recycling the raw materials.
[0016]
In the present invention, a general measurement method may be used as a method for confirming the presence or absence of performance deterioration of the ion exchange resin before passing the hydrogen peroxide solution, and regarding the chemical strength, the moisture (water content) in the resin, the total Exchange capacity, neutral salt decomposition capacity, weak acid group exchange capacity, weak base exchange capacity, etc., and physical strength, compressive strength, appearance index (complete ball ratio), etc. are measured. This is sufficient for the cation exchange resin, but for the anion exchange resin, there is no problem with these general measurement items, but the decomposition of hydrogen peroxide is large when it is actually used for the treatment with hydrogen peroxide water. Resin is present. As a method for determining the presence or absence of this heat generation / decomposition, the present inventors are carrying out the following test method (hereinafter referred to as jar test). First, 100 ml of wet sample resin is weighed, wrapped in a filter cloth, and drained. As pretreatment operations, immersion is performed in order of 7.5% by weight of hydrogen peroxide solution for 15 minutes, 31% by weight of hydrogen peroxide solution for 15 minutes, and 31% by weight of hydrogen peroxide solution for 10 minutes. Move up and down during immersion. Remove the resin from the liquid and transfer the entire amount to a heat insulating container such as a Dewar bottle. Use non-contaminated items such as Teflon spoons for transportation. Subsequently, 100 ml of 31 wt% hydrogen peroxide water is added, and temperature measurement is started. The temperature at this time is T 0 (° C.). The temperature after 5 hours is measured, and the temperature at this time is defined as T 5 (° C.). The above operation is performed at room temperature, and as a hydrogen peroxide solution to be used for the test, a hydrogen peroxide solution commercially available for use in the electronics industry is generally used. The liquid temperature increasing rate ΔT (° C./hour) is expressed by the following equation.
ΔT = (T 5 −T 0 ) / 5 (° C./hour)
If the liquid temperature rise rate ΔT exceeds 2 ° C / hour for purification of hydrogen peroxide solution, hydrogen peroxide may be rapidly decomposed during continuous operation, resulting in danger of removing impurities. Will fall. Of course, the jar test is a test method that can be applied to the selection of a new resin. The test method described above does not necessarily need to be performed every time the hydrogen peroxide solution is purified.
[0017]
According to the present invention, the above-described general test items and ion exchange resins that are almost the same as new ones in this jar test can be used for the purification of hydrogen peroxide solution. In the case of an anion exchange resin, it can be used repeatedly over 6 months.
[0018]
【Example】
Hereinafter, the present invention will be described with reference to examples and comparative examples. The metal component was analyzed by ICP-MS, the anion component was analyzed by ion chromatography, and the total nitrogen was analyzed by catalytic oxidation absorption.
Example 1
An ion exchange resin tower filled with anion exchange resin SA10A (Lot 7C101) manufactured by Mitsubishi Chemical Co., Ltd. prepared in a hydrogen carbonate type, and a cation exchange resin C-20H manufactured by Rohm & Haas Co., Ltd. prepared in an H type in another ion exchange resin tower. Filled. The roughly purified hydrogen peroxide solution using a reverse osmosis membrane was passed through the anion exchange resin at a rate of SV = 3 hour −1 at a rate of upflow, and then the cation exchange resin was downflowed at a rate of SV = 4 hour −1. The liquid was passed through. The liquid flow was carried out at 7 ° C. and continued for 20 days. Table 1 shows the quality of the hydrogen peroxide solution after purification. Immediately after completion of the flow, ultrapure water was passed at a rate of SV = 5 hour −1 for 24 hours to perform water replacement. One month later, the hydrogen peroxide solution was purified again. The liquid was passed under the same conditions as the first time. Prior to re-use of the anion exchange resin, a 2N aqueous sodium hydroxide solution was passed for 2 hours at SV = 5 hour -1 and the water was replaced, and then a 2N aqueous hydrochloric acid solution was supplied at SV = 5 hour -1 . The solution was passed through for 1 hour, and after substitution with water, a 2N aqueous sodium hydroxide solution was passed through for 2 hours at SV = 5 hour −1. After the water substitution, a 0.7N aqueous sodium hydrogen carbonate solution was delivered at SV = 5 hour −1. For 2 hours to convert to the hydrogen carbonate type, and finally, ultrapure water was passed for 72 hours at SV = 10 hour −1 for washing. Prior to re-use of the cation exchange resin, a 2N hydrochloric acid aqueous solution is passed for 4 hours at SV = 5 hour -1 to convert to H type, and then ultrapure water is passed for 92 hours at SV = 5 hour -1 for 92 hours. And washed. Immediately before the start of purification of the hydrogen peroxide solution, ultrapure water was passed for 12 hours at SV = 5 hour −1 for washing. Table 1 shows the quality of the hydrogen peroxide solution after purification. In addition, after the regeneration was completed, a part of the anion exchange resin was extracted and a jar test was performed.
[0019]
Comparative Example 1
The same test as in Example 1 was performed, except that the water replacement after the first purification was performed only for 2 hours at a rate of SV = 5 hour −1 . The results are shown in Table 1.
[0020]
Example 2
An ion exchange resin tower is filled with an anion exchange resin SA10A (lot 7C101) manufactured by Mitsubishi Chemical Co., which is prepared in a hydrogen carbonate type, and another ion exchange resin tower is filled with an cation exchange resin ESG-K made by Organo, which is prepared in an H type. did. The roughly purified hydrogen peroxide solution using a reverse osmosis membrane is passed through the anion exchange resin at a rate of SV = 4 hour −1 , followed by a downward flow at the rate of SV = 4 hour −1 through the cation exchange resin. The liquid was passed through. The liquid flow was carried out at 5 ° C. and continued for 12 days. Table 2 shows the quality of the hydrogen peroxide solution after purification. Immediately after completion of the flow, ultrapure water was passed for 2 hours at a rate of SV = 10 hour −1 to perform water replacement. Ten days later, the hydrogen peroxide solution was purified again. The liquid was passed under the same conditions as the first time. Prior to re-use of the anion exchange resin, a 2N aqueous sodium hydroxide solution was passed for 2 hours at SV = 5hour −1 and after water replacement, a 0.7N aqueous sodium hydrogen carbonate solution was added to SV = 5hour −. The solution was passed through 1 for 2 hours to convert to the hydrogen carbonate type. Finally, ultrapure water was passed for 24 hours at SV = 10 hour −1 for washing. Prior to re-use of the cation exchange resin, a 2N hydrochloric acid aqueous solution is passed for 6 hours at SV = 5 hour -1 to convert to H type, and then ultrapure water is passed for 24 hours at SV = 10 hour -1. And washed. Table 1 shows the quality of the hydrogen peroxide solution after purification.
[0021]
Comparative Example 2
A test was performed in the same manner as in Example 2 except that water replacement was not performed after the first purification. The results are shown in Table 1.
[0022]
[Table 1]
【The invention's effect】
As described above, according to the present invention, it is a technique for removing impurities in hydrogen peroxide water by subjecting it to a contact treatment with an ion exchange resin, and it is dangerous because hydrogen peroxide rapidly decomposes during continuous operation. There is no extremely inconvenient problem from the viewpoint of industrial implementation that continuous operation over a long period of time, such as the effect of removing impurities or reduced, is difficult. It was possible to provide a method for purifying hydrogen peroxide that has the characteristics of being possible and that can realize a technique that is extremely advantageous from the viewpoint of industrial implementation.
Claims (4)
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| JP08241299A JP3724247B2 (en) | 1999-03-25 | 1999-03-25 | Method for purifying hydrogen peroxide water |
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| KR101814304B1 (en) * | 2013-12-26 | 2018-01-04 | 오르가노 코포레이션 | Anion exchanger, mixture of anion exchanger and cation exchanger, mixed bed comprising anion exchanger and cation exchanger, production processes therefor, and method for purifying aqueous hydrogen peroxide solution |
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| JP5704979B2 (en) * | 2011-03-10 | 2015-04-22 | 三徳化学工業株式会社 | Method for producing purified hydrogen peroxide water |
| JP6444392B2 (en) * | 2013-10-02 | 2018-12-26 | ソルヴェイ（ソシエテ アノニム） | Method for producing purified aqueous hydrogen peroxide solution |
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| JP7477373B2 (en) | 2020-06-04 | 2024-05-01 | オルガノ株式会社 | Method for changing ion type of monolithic organic porous anion exchanger and method for producing monolithic organic porous anion exchanger |
| JP7421019B1 (en) | 2022-10-06 | 2024-01-23 | オルガノ株式会社 | Method for producing cation exchange resin and method for purifying organic acid solution |
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1999
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101814304B1 (en) * | 2013-12-26 | 2018-01-04 | 오르가노 코포레이션 | Anion exchanger, mixture of anion exchanger and cation exchanger, mixed bed comprising anion exchanger and cation exchanger, production processes therefor, and method for purifying aqueous hydrogen peroxide solution |
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