JP2004059719A - Crosslinkable ionic water soluble polymer powder, its preparing method and its using method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crosslinkable ionic water soluble polymer powder which can be easily prepared at a low cost and with high performance, and its preparing method and its using method. <P>SOLUTION: The crosslinkable ionic water soluble polymer powder can be prepared by polymerizing a high concentration aqueous solution composed of a monomer mixture comprising (A) a water soluble cationic vinyl monomer and (B) a water soluble polycation crosslinking agent to be represented by formula (1) as the essential components, and optionally one or more kinds to be selected from (C) a water soluble anionic vinyl monomer and (D) a water soluble nonionic monomer, evaporating the water content of the above aqueous solution by polymerization heat of the above polymerization to obtain a low water content polymerized product, and rendering the obtained product fine particles suitably through a drying step. <P>COPYRIGHT: (C)2004,JPO

Description

一般式（１）
【化２】
ただしＡは、

一般式（２）
（Ｒ_１、Ｒ_２：水素、炭素数１〜３のアルキル基またはベンジル基。ただし水素である場合は、部分的に前記一般式［１］中のＡに置換されても良い。Ｒ_３：水素またはメチル基、Ｒ_４、Ｒ_５：炭素数１〜３のアルキル基、Ｒ_６：炭素数２〜４のアルキレン基またはヒドロキシ置換アルキレン基、ｎ：０〜７０の整数、Ｂ：−Ｏ−またはＮＨ−、Ｘ⁻は陰イオンである。）
【０００５】
請求項２の発明は、前記水溶液が４０〜９５重量％の範囲であることを特徴とする請求項１に記載の架橋性イオン性水溶性高分子粉末である。
【０００６】
請求項３の発明は、前記単量体混合物が、（Ａ）、（Ｃ）及び（Ｄ）の組成として（Ａ）水溶性カチオン性ビニル単量体５〜１００ｍｏｌ％、（Ｃ）水溶性アニオン性ビニル単量体０〜５０ｍｏｌ％、（Ｄ）水溶性非イオン性単量体０〜９５ｍｏｌ％であり、重合後の高分子が水溶性を保つ範囲で（Ａ）、（Ｃ）及び（Ｄ）に対し（Ｂ）水溶性ポリカチオン架橋剤が添加されたものであることを特徴とする請求項１あるいは２に記載の架橋性イオン性水溶性高分子粉末である。
【０００７】
請求項４の発明は、前記一般式（１）中のｎが１〜５０であることを特徴とする請求項１〜３に記載の架橋性イオン性水溶性高分子粉末である。
【０００８】
請求項５の発明は、前記架橋性水溶性高分子が、２５℃の１Ｎ硝酸ナトリウム水溶液中で極限粘度を測定した場合、０．１〜２０．０ｄｌ／ｇの範囲であることを特徴とする請求項１〜４に記載の架橋性イオン性水溶性高分子粉末である。
【０００９】
請求項６の発明は、前記（Ａ）水溶性カチオン性ビニル単量体、前記（Ｃ）水溶性アニオン性ビニル単量体及び前記（Ｄ）水溶性非イオン性単量体の合計重量に対して、前記（Ｂ）ポリカチオン架橋剤が５〜２００００ｐｐｍ含まれることを特徴とする請求項１〜５に記載の架橋性イオン性水溶性高分子粉末である。
【００１０】
請求項７の発明は、前記（Ａ）水溶性カチオン性ビニル単量体、前記（Ｃ）水溶性アニオン性ビニル単量体及び前記（Ｄ）水溶性非イオン性単量体の合計重量に対して、（Ｂ）ポリカチオン架橋剤が５〜２０００ｐｐｍの範囲にあるとき、下記数式（２）で表現されるカチオン保持率ａが０．９＜ａ≦１．０の範囲であることを特徴とする請求項１〜６に記載の架橋性イオン性水溶性高分子粉末である。
ａ＝ｂ／ｃ　　　　　　　　・・・数式（２）
ただし、ｂは架橋性水溶性高分子のカチオン当量値、ｃは（Ｂ）ポリカチオン架橋剤を除く単量体が同一組成において重合した場合の水溶性高分子のカチオン当量理論値である。
【００１１】
請求項８の発明は、前記（Ａ）水溶性カチオン性ビニル単量体、前記（Ｃ）水溶性アニオン性ビニル単量体及び前記（Ｄ）水溶性非イオン性単量体の合計重量に対して、（Ｂ）ポリカチオン架橋剤が５〜２００００ｐｐｍの範囲にあるとき、下記数式（２）で表現されるカチオン保持率ａが０．５≦ａ≦０．９の範囲であることを特徴とする請求項１〜６に記載の架橋性イオン性水溶性高分子粉末である。
ａ＝ｂ／ｃ　　　　　　　　・・・数式（２）
【００１２】
請求項９の発明は、（Ａ）水溶性カチオン性ビニル単量体及び（Ｂ）前記一般式（１）で表わされる水溶性ポリカチオン架橋剤を必須成分とし、適宜（Ｃ）水溶性アニオン性ビニル単量体及び（Ｄ）水溶性非イオン性単量体から選択される一種以上を加えた単量体混合物からなる高濃度の水溶液を重合させ、前記重合の重合熱により前記水溶液の水分を蒸発させ、低含水率の重合物を得た後、適宜乾燥工程を経て細粒化することを特徴とする架橋性イオン性水溶性高分子粉末の製造方法である。
【００１３】
請求項１０の発明は、請求項１〜８に記載の架橋性イオン性水溶性高分子粉末を溶解して水溶液とし、生物処理後の有機汚泥に添加、混合した後、脱水機により脱水することを特徴とする架橋性イオン性水溶性高分子粉末の使用方法である。
【００１４】
【発明の実施の形態】
本発明の架橋性イオン水溶性高分子粉末は、（Ａ）水溶性カチオン性ビニル単量体及び（Ｂ）下記一般式（１）で表わされるポリカチオン架橋剤を必須成分とし、適宜（Ｃ）水溶性アニオン性ビニル単量体及び（Ｄ）水溶性非イオン性単量体から選択される一種以上を加えた単量体混合物からなる高濃度の水溶液を重合させることにより重合物を得た後、適宜乾燥工程を経て細粒化して製造することができる。細粒化の方法としては、一般的に当該業者間で知られているいずれの方法も使用することができる。例えば、分散剤および分散媒の存在下で懸濁重合を行い噴霧乾燥する方法、貧溶媒中で分散剤の存在下分散重合し乾燥する方法、高濃度で水溶液重合した後強熱乾燥し粉砕する方法等があげられる。製造コストや製造の容易さを考慮すると、高濃度で水溶液重合した後乾燥し粉砕する方法が好適である。
【００１５】
本発明の架橋性イオン水溶性高分子粉末を重合する場合、重合時の水溶液中の単量体濃度は４０〜９５重量％の範囲であり、好ましくは７０重量％〜９５重量％の範囲である。４０重量％以下では、重合後の乾燥工程に多大なエネルギーと作業が要求され不必要なコストがかかる。また本発明の重合反応では７０重量％以上の濃度で水溶液重合を行うと、重合熱を利用することで水分を除去する乾燥工程において有利となる。９５重量％以上の濃度では、高分子量のカチオン水溶性架橋高分子を製造することが難しいだけでなく、単量体の濃縮、精製過程に不必要な作業とコストがかかり不利である。
【００１６】
従来、高濃度重合した後、直接重合物を粉砕して高分子の粉末を製造する方法においては、架橋剤は添加して重合しないことが一般的であった。その理由として、この方法では、Ｎ，Ｎ−メチレンビスアクリルアミドのような従来の架橋剤を添加して重合すると架橋反応が進みすぎて多くの場合、高分子ゲルを生成し、水溶性高分子を得ることは非常に困難であった。すなわち、対単量体当たり、重量で１〜数ｐｐｍの架橋剤を添加すれば水溶性高分子を得ることは、可能であっても目的とする架橋度の水溶性高分子を安定して製造することは、不可能に近い。
その点本発明で使用するポリカチオン架橋剤は、水溶性高分子を製造する場合、添加量範囲が非常に広く架橋度をコントロールすることが容易である。例えば対単量体当たり、重量で５〜２００００ｐｐｍ添加しても製造条件を変えることにより水溶性高分子を製造することができる。
【００１７】
次に本発明で使用するポリカチオン架橋剤について説明する。前記ポリカチオン架橋剤は、（Ｅ）エピハロヒドリンと（Ｆ）アンモニア、第一級アミン、または第ニ級アミン、および（Ｇ）第三級アミノ基含有アクリルモノマーを反応させ、その反応物の末端の少なくともニつがビニル基を有する。（Ｅ）エピハロヒドリンは、特に制限はなく、例えばエピクロロヒドリン、エピブロモヒドリン、エピヨードヒドリンなどを挙げることができる。これらの（Ｅ）成分は一種を単独で用いることができ、あるいは、ニ種以上を組み合わせて用いることもできる。これらのエピハロヒドリンの中で、好ましくは、エピクロロヒドリンである。
【００１８】
（Ｆ）成分のアンモニア、第一級アミンおよび第ニ級アミンは、それぞれを単独で用いることができ、アンモニアと第一級アミン、アンモニアと第ニ級アミン、第一級アミンと第ニ級アミンのニ成分を組み合わせて用いることもでき、あるいはアンモニアと第一級アミンと第ニ級アミンの三成分を組み合わせて用いることもできる。前記第１級アミンは、特に制限はなく、例えばメチルアミン、エチルアミン、ｎ−プロピルアミン、イソプロピルアミンなどを挙げることができる。これらの第一級アミンは一種を単独で用いることができ、あるいは、ニ種以上を組み合わせて用いることもできる。これらの第一級アミンの中で、好ましくは、メチルアミンおよびエチルアミンである。前記第ニ級アミンは、特に制限はなく、例えばジメチルアミン、ジエチルアミン、ジプロピルアミン、メチルエチルアミン、メチルプロピルアミン、ジベンジルアミンなどを挙げることができる。これらの第ニ級アミンの中で、好ましくは、ジメチルアミン、ジエチルアミンおよびメチルエチルアミンである。
【００１９】
（Ｇ）の第三級アミノ基含有アクリルモノマーは、特に制限はなく、例えばＮ，Ｎ−ジメチルアミノプロピル（メタ）アクリルアミド、Ｎ，Ｎ−ジエチルアミノプロピル（メタ）アクリルアミド、Ｎ，Ｎ−ジメチルアミノブチル（メタ）アクリルアミド、Ｎ，Ｎ−ジエチルアミノブチル（メタ）アクリルアミド、Ｎ，Ｎ−ジメチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ−ジエチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ−メチルエチルアミノプロピル（メタ）アクリルアミド、Ｎ，Ｎ−メチルエチルアミノエチル（メタ）アクリレートなどを挙げることができる。これらの（Ｆ）成分は一種を単独で用いることができ、あるいは、２種以上を組み合わせて用いることもできる。これらモノマーのうち、Ｎ，Ｎ−ジメチルアミノプロピルアクリルアミドは、分子中にエステル結合をもつ第三級アミノ基含有アクリルモノマーよりも耐アルカリ加水分解性があるので、本発明の（Ｃ）成分に用いる（Ｆ）第三級アミノ基含有アクリルモノマーとして好ましい。
【００２０】
本発明で使用するポリカチオン架橋剤は、その末端の少なくとも二つがビニル基を有するものである。それ以外の末端の構造については特に制限はなくアミノ基、第ニ級アミン構造、第三級アミン構造、ハロヒドリン構造、グリシジル基、ヒドロキシプロピル基などとすることができる。前記一般式（１）で表される構造単位数ｎは、（Ｅ）成分に対する（Ｆ）成分の比により任意に調節する事ができるが、ｎは好ましくは１以上７０以下であり、さらに好ましくは１以上５０以下である。一般的に（Ｅ）成分と（Ｆ）成分の反応物は分子量の異なる高分子の混合物であるが、ｎが０である反応物は架橋剤としての反応性が高く、本発明の水溶性架橋高分子の製造に使用した場合、高分子が不溶化しやすく不都合である。ｎが７１以上のポリカチオン架橋剤を製造することは難しく、さらにｎが５０以上の反応物を製造するためには多量の残存単量体が残る条件が必要であり、残存単量体の影響が大きい系では好ましくない。
【００２１】
本発明で使用する水溶性ポリカチオン架橋剤は、（Ｅ）成分と（Ｆ）成分および（Ｇ）成分を反応させて製造することができる。本発明の水溶性ポリカチオン架橋剤の製造方法に特に制限はなく、例えば（Ｅ）成分を反応器に仕込み（Ｆ）成分を滴下し、（Ｅ）成分と（Ｆ）成分を反応した後、（Ｇ）成分を加えて反応することができる。好ましい方法は、（Ｅ）成分を反応器に仕込み、（Ｆ）成分を滴下し、（Ｅ）成分と（Ｆ）成分を反応した後、（Ｇ）成分を加えて反応する方法が好ましい。（Ｆ）成分と（Ｇ）成分を混合するとミカエル付加反応により反応し不都合である。また、（Ｅ）成分を先に反応器に仕込むことで、（Ｅ）成分と（Ｆ）成分を反応して得られるカチオン性高分子の末端が、グリシジル基及び／またはハロヒドリン構造になりやすくなり、（Ｇ）成分を反応するのに好都合である。（Ｅ）成分に対する（Ｆ）成分のモル比は、所望する架橋剤の性状、構造、分子量などによって適宜選択されるが一般的には０．２５〜１．２０の範囲である。（Ｅ）成分に対する（Ｆ）成分のモル比が０．２５以下の場合、（Ｅ）成分が残存する。（Ｅ）成分に対する（Ｆ）成分のモル比が１．２０以上の場合、（Ｅ）成分と（Ｆ）成分の反応により得られるカチオン性高分子の末端にハロヒドリン構造および／またはグリシジル基が存在せず、（Ｇ）成分と反応しない。
【００２２】
（Ｅ）成分に対する（Ｇ）成分のモル比は特に制限はないが、好ましくは０．２４以下の範囲である。（Ｅ）成分に対する（Ｇ）成分のモル比が０．２４より大きいとポリカチオン架橋剤中に（Ｇ）成分が残存する。（Ｅ）成分と（Ｆ）成分は容易に反応するため、カチオン性高分子を得ることができる。またエピハロヒドリンに対してモル比で１．０以下の範囲の、水酸化ナトリウム等のアルカリ触媒を加えて反応を行うこともできる。反応を行う温度の範囲は、所望する架橋剤の性状、構造、分子量などによって適宜選択されるが一般的には１０〜９０℃、好ましくは２０〜６０℃の範囲である。反応を行う温度が２０℃以下では、反応速度が遅く実用的でないし、６０℃以上では（Ｅ）成分と（Ｆ）成分の反応により得られるカチオン性高分子の末端のハロヒドリン構造が加水分解され（Ｇ）成分と反応せしめることができなくなる。反応時間は反応温度などにより左右されるが通常は２４時間以内で充分である。
【００２３】
本発明の架橋性イオン性水溶性高分子粉末を製造する場合使用する、水溶性カチオンビニル単量体は、共重合する場合使用するアニオン性単量体や水溶性非イオン性単量体と共重合可能な水溶性カチオンビニル単量体であれば特に制限はなく、例えば、Ｎ，Ｎ−ジメチルアミノプロピル（メタ）アクリルアミド、Ｎ，Ｎ−ジエチルアミノプロピル（メタ）アクリルアミド、Ｎ，Ｎ−ジメチルアミノブチル（メタ）アクリルアミド、Ｎ，Ｎ−ジエチルアミノプロピル（メタ）アクリルアミド、Ｎ，Ｎ−ジメチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ−ジエチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ−メチルエチルアミノプロピル（メタ）アクリルアミド、Ｎ，Ｎ−メチルエチル（メタ）アクリレート等の第三級アミノ基含有ビニル単量体または、塩酸、硫酸あるいは酢酸等の無機または有機酸の塩類、あるいは、第三級アミノ基含有ビニル単量体とメチルクロライド、ベンジルクロライドもしくはエピクロロヒドリン等の四級化剤との反応によって得られる第四級アンモニウム塩、ビニルイミダゾリン、２−ビニルピリジン、４−ビニルピリジン、あるいはジアリルジメチルアンモニウム塩化物、ジアリルメチルベンジルアンモニウム塩化物といったジメチルジアリルアンモニウム系単量体、さらには（Ｃ）成分であるポリカチオン架橋剤の副生成物であるマクロモノマー等があげられる。これら水溶性カチオン性ビニル単量体は、その一種または二種以上を用いることができる。また、水溶性非イオン性単量体は、共重合可能な任意ものが使用できるが、最もこのましいのはアクリルアミドである。
【００２４】
両性水溶性高分子を製造する場合には、前記水溶性カチオン性ビニル単量体と水溶性非イオン性ビニル単量体に加えて、さらに一般式（３）で表される水溶性アニオン性ビニル単量体を共重合する。その例としては、スルフォン基でもカルボキシル基でもさしつかいなく、両方を併用しても良い。スルフォン基含有単量体の例は、ビニルスルフォン酸、ビニルベンゼンスルフォン酸あるいは２−アクリルアミド２−メチルプロパンスルフォン酸などである。またカルボキシル基含有単量体の例は、メタクリル酸、アクリル酸、イタコン酸、マレイン酸あるいはｐ−カルボキシスチレンなどである。
【００２５】
前記水溶性カチオン性ビニル単量体、水溶性非イオン性ビニル単量体および水溶性カチオン性ビニル単量体の架橋性水溶性イオン性高分子中の共重合モル％は、
以下のようになる。すなわち、架橋性水溶性カチオン性高分子の場合は、水溶性カチオン性ビニル単量体５〜１００モル％、水溶性非イオン性ビニル単量体０〜９５モル％であり、好ましくは水溶性カチオン性ビニル単量体２０〜１００モル％、水溶性非イオン性ビニル単量体０〜８０モル％である。また、架橋性水溶性両性高分子の場合は、水溶性カチオン性ビニル単量体５〜１００モル％、水溶性非イオン性ビニル単量体０〜９０モル％、水溶性アニオン性ビニル単量体５〜５０モル％であり、好ましくは水溶性カチオン性ビニル単量体２０〜１００モル％、水溶性非イオン性ビニル単量体０〜８０モル％、水溶性アニオン性ビニル単量体１０〜５０モル％である。またその使用目的によって適宜選択されることは当然であるが、汚泥の脱水剤等、高いカチオン密度が要求される場合は一般的には、水溶性カチオン性ビニル単量体５０〜１００ｍｏｌ％、水溶性非イオン性ビニル単量体０〜５０ｍｏｌ％である。
【００２６】
本発明のカチオン水溶性架橋高分子を重合する場合、ラジカル重合開始剤としては一般的な水溶性ポリマーの重合に用いられるラジカル重合開始剤のいずれも用いることができる。これら開始剤は油溶性あるいは水溶性のどちらでも良く、アゾ系、過酸化物系、レドックス系、さらには、可視光または紫外線照射によって開始される光ラジカル重合開始系のいずれでも重合することが可能である。例えば油溶性アゾ系開始剤の例としては、２、２’−アゾビスイソブチロニトリル、１、１’−アゾビス（シクロヘキサンカルボニトリル）、２、２’−アゾビス（２−メチルブチロニトリル）、２、２’−アゾビス（２−メチルプロピオネ−ト）、４、４−アゾビス（４−メトキシ−２、４ジメチル）バレロニトリルなどがあげられ、水混溶性溶剤に溶解し添加する。水溶性アゾ系開始剤の例としては、２、２’−アゾビス（アミジノプロパン）二塩化水素化物、２、２’−アゾビス〔２−（５−メチル−２−イミダゾリン−２−イル）プロパン〕二塩化水素化物、４、４’−アゾビス（４−シアノ吉草酸）などがあげられる。
【００２７】
またレドックス系の例としては、ペルオキソ二硫酸アンモニウムと亜硫酸ナトリウム、亜硫酸水素ナトリウム、トリメチルアミン、テトラメチルエチレンジアミンなどとの組み合わせがあげられる。過酸化物の例としては、ペルオキソ二硫酸アンモニウムあるいはカリウム、過酸化水素、ベンゾイルペルオキサイド、ラウロイルペルオキサイド、オクタノイルペルオキサイド、サクシニックペルオキサイド、ｔ−ブチルペルオキシ２−エチルヘキサノエ−トなどをあげることができる。光ラジカル重合開始剤の例としては、ベンゾインエチルエステル、ベンゾインイソプロピルエステル、ベンゾインイソブチルエステル等のベンゾインエステル類、あるいは２，２−ジエトキシアセトフェノン等のアセトフェノン類などのような１成分系、また、ベンジル、ベンゾフェノン、アントラキノン、チオキサントン等の芳香族ケトンとＮ−メチル−Ｎ，Ｎ−ジエタノールアミン等の水素供与体の組み合わせである２成分系があげられる。水素供与体の例としてはＮ−メチル−Ｎ，Ｎ−ジエタノールアミン等のアミン類のほか、イソプロピルアルコール等のアルコール類、２−メルカプトエタノール等のチオール類をあげることができる。また、開始剤の無い状態でラジカルを発生させることができる放射線重合を行うこともできる。
【００２８】
重合開始剤の濃度は、通常アゾ化合物では単量体の重量に対して５〜５００００ｐｐｍの重量の範囲、レドックス開始剤の過酸化物と還元剤はどちらも単量体の重量に対して５〜５００００ｐｐｍの重量の範囲であり、光ラジカル重合開始剤では１成分系ではモノマーの重量に対して５〜５００００ｐｐｍの重量の範囲、２成分系では芳香族ケトンと水素供与体ともに単量体の重量に対して５〜５００００ｐｐｍの重量の範囲である。
【００２９】
重合反応は、不活性ガス雰囲気下で反応温度１５〜１００℃にて行われ、好ましくは２０〜９０℃の範囲である。反応温度が２０℃以下では重合速度が遅く非効率的であるし、９０℃以上では反応速度が速く、高分子鎖の枝分かれ等目的の高分子を得るのに不都合な反応が発生しやすい。
【００３０】
以上のようにして得られる本発明の架橋性水溶性イオン性高分子は、本発明で使用する水溶性ポリカチオン架橋剤を共存させて重合した場合には、側鎖にカチオン性単位構造を持つグラフト共重合体を生成する。あるいはまた架橋点間に同一のカチオン性構造を持つブロック共重合体の構造からなる架橋型高分子である。すなわち、水溶性ポリカチオン架橋剤を製造する場合の原料となるエピハロヒドリンとアミン類との縮合物の構造単位を側鎖あるいは架橋点間に有するグラフト構造やブロック構造を有する水溶性イオン性高分子となる。
【００３１】
本発明の架橋性水溶性イオン性高分子の２５℃における１Ｎ硝酸ナトリウム水溶液中での極限粘度は、必要とされるカチオン水溶性高分子の性質、反応条件あるいは使用目的によって異なるが、一般的に０．１〜２０ｄｌ／ｇの範囲であり、凝集剤として使用する場合は１〜２０ｄｌ／ｇであり、好ましくは２〜１５ｄｌ／ｇである。
【００３２】
本発明の架橋性水溶性イオン性高分子は、前期水溶性ポリカチオン架橋剤が水溶性カチオン性ビニル単量体、水溶性非イオン性ビニル単量体及び水溶性アニオン性ビニル単量体の合計重量に対して、重量で５〜２００００ｐｐｍ含まれることが好ましい。水溶性ポリカチオン架橋剤が５ｐｐｍ以下では、イオン性水溶性高分子に架橋した効果が現れないし、２００００ｐｐｍ以上では、架橋度の調整が困難であるだけでなく、不溶解分の増大による性能の低下と製造コストの増大につながり不利である。
【００３３】
本発明における架橋剤を用いた架橋性水溶性イオン性高分子は、その物性から二つに分類することができる。第一は、架橋性水溶性イオン性高分子の分子量が相対的に高い場合である。この場合、架橋性水溶性イオン性高分子中の架橋度、すなわち重合連鎖中の架橋点の数であるが、この架橋度が少ない場合である。この場合、水溶性ビニル単量体の合計重量に対し５〜２０００ｐｐｍの架橋剤を添加して重合する、いわゆる低架橋度の架橋性水溶性イオン性高分子（１）である。
【００３４】
もう一つは、架橋性水溶性イオン性高分子の分子量が相対的に低い場合である。この場合、架橋性水溶性イオン性高分子中の架橋度が高い場合である。この場合、水溶性ビニル単量体の合計重量に対し１００〜２００００ｐｐｍの架橋剤を添加して重合する、いわゆる高架橋度の架橋性水溶性イオン性高分子（２）である。
【００３５】
通常、カチオン性あるいは両性水溶性高分子は、コロイド滴定法等によりカチオン当量値を測定することができる。一般的に架橋性水溶性イオン性高分子は、架橋を架けていない水溶性イオン高分子と比較してカチオン当量値が低く測定され、架橋剤の添加量が多く架橋度が高いものほどカチオン当量値が低く測定される傾向がある。本発明では、数式（２）で表されるカチオン保持率ａにより低架橋度のカチオン水溶性高分子（１）と高架橋度のカチオン水溶性高分子（２）を区分する。
ａ＝ｂ／ｃ　　　　　　　　・・・数式（２）
ただし、ｂはカチオン水溶性架橋高分子のカチオン当量値、ｃは同一組成で架橋剤を含まないカチオン水溶性高分子のカチオン当量理論値である。
【００３６】
本発明の請求項７の発明は、請求項１〜６に記載の製造方法において、水溶性単量体の合計重量に対して重量で５〜２０００ｐｐｍの範囲にあるとき、数式（２）で表現されるカチオン保持率ａが０．９＜ａ≦１．０の範囲であることを特徴とする架橋性水溶性イオン性高分子の製造方法である。この架橋性水溶性イオン性高分子は、低架橋度の架橋性水溶性イオン性高分子（１）に充当する。
【００３７】
本発明の請求項８の発明は、請求項１〜６に記載の製造方法において、水溶性単量体の合計重量に対し１００〜２００００ｐｐｍの範囲で水溶性ポリカチオン架橋剤を添加した場合、数式（２）で表現されるカチオン保持率ａが０．５≦ａ≦０．９の範囲であることを特徴とする架橋性水溶性イオン高分子粉末の製造方法である。また好ましくは０．８≦ａ≦０．９の範囲である。このカチオン水溶性架橋高分子は、高架橋度のカチオン水溶性高分子（２）に充当する。カチオン保持率ａが０．８より低くなると０．８以上のものと比較して、汚泥脱水剤として用いた場合、凝集性能、汚泥の脱水性能等が低下する。さらに、０．５より低くなると凝集、汚泥の脱水に対してほとんど効果が無くなる。
【００３８】
本発明の架橋性水溶性イオン高分子粉末は、例えば汚泥脱水剤として使用することができる。適用可能な汚泥は、製紙排水、化学工業排水、食品工業排水などの生物処理したときに発生する余剰汚泥、あるいは都市下水の生汚泥、混合生汚泥、余剰汚泥、消化汚泥などの有機汚泥であるが、最も適する汚泥は、都市下水の混合生汚泥および消化汚泥である。また、本発明のイオン性高分子の添加量は、汚泥固形分に対し重量で０．１〜３．０％であり、好ましくは０．２〜２．０％である。
【００３９】
【実施例】
以下、実施例および比較例によって本発明をさらに詳しく説明するが、本発明はその要旨を超えない限り、以下の実施例に制約されるものではない。
【００４０】
（架橋剤合成例）温度計、攪拌機、滴下漏斗を備えた４つ口のセパラブルフラスコに、エピクロロヒドリン１４６．６ｇを仕込み、ジメチルアミンの５０重量％水溶液１２３．８ｇを４０〜４５℃で２時間かけて滴下し、滴下終了後４５℃で１時間反応した。コロイド滴定を行った結果、このもののジメチルアミンの反応率は１００．０％だった。またアミンの中和滴定を行った結果、第３級アミンは１％以下だった。このものをガスクロマトグラフィーにより測定したところ、残存するエピクロロヒドリンは検出されなかった。反応後、ジメチルアミノプロピルアクリルアミド２１．０ｇ添加して２５℃で１５時間反応し、３６．５ｇのイオン交換水を加えて、７０．０重量％濃度の淡黄色透明の水溶性ポリカチオン架橋剤３２７．９ｇを得た。アミンの中和滴定を行った結果、第三級アミンは８．５％だった。このものの分子量をゲルパーミエーションクロマトグラフィーにより測定したところ、ポリアクリルアミド換算の重量平均分子量は、１，４６０であった。このもののカチオン当量値は、６．５２ｍｅｑ／ｇだった。
【００４１】
【実施例１】
容器にメタクリロイロキシエチルトリメチルアンモニウムクロライド１００ｍｏｌ％（８０重量％水溶液２５．０ｇ）と架橋剤合成例で合成した水溶性ポリカチオン架橋剤をメタクリロイロキシエチルトリメチルアンモニウムクロライドの重量に対して重量で１０ｐｐｍ（０．１重量％水溶液０．２ｇ）を仕込み、２，２’−アゾビス（２−アミジノプロパン）ジヒドロクロライドをメタクリロイロキシエチルトリメチルアンモニウムクロライドの重量に対して０．１重量％（１０重量％水溶液０．２ｇ）添加後攪拌しモノマー溶液を得た。この溶液を、窒素雰囲気下５０℃で２時間重合を行った。重合後、ポリビーカーから取り出し１００℃で１５時間乾燥した。乾燥後、粉砕して粉末状にし２１．２ｇの架橋性水溶性カチオン性高分子粉末を得た。（試料１）このものの０．５％水溶液の粘度をブルックフィールド型粘度計で測定した。さらに、１Ｎ硝酸ナトリウム水溶液中での２５℃において、０．２、０．１、０．０５ｇ／ｄｌの各濃度の溶液を調製し、
還元粘度をオストワルト型粘度計で測定したのち、濃度０に外挿することにより極限粘度を求めた。またコロイド滴定によるカチオン当量値を測定した。更に、この架橋性水溶性高分子のカチオン当量値と、同一組成で架橋剤を含まないカチオン水溶性高分子のカチオン当量理論値から数式（２）で表されるカチオン保持率を計算した。この結果を表２に示す。
【００４２】
【実施例２〜７】
架橋剤合成例で合成したポリカチオン架橋剤と２，２’−アゾビス（２−アミジノプロパン）ジヒドロクロライドの添加量を表１に示す量に変えた以外は実施例１と同様な方法で架橋性水溶性イオン性高分子粉末を得た。（試料２〜７）これらの０．５％水溶液の粘度、２５℃の１Ｎ硝酸ナトリウム水溶液中での還元粘度、カチオン当量値とカチオン保持率を実施例１と同様に評価した。この結果を表２に示す。
【００４３】
【実施例８〜１１】
単量体の種類と組成、架橋剤合成例で合成したポリカチオン架橋剤および２，２’−アゾビス（２−アミジノプロパン）ジヒドロクロライドの添加量を表１に示す量に変えた以外は実施例１と同様な方法で架橋性水溶性イオン性高分子粉末を得た。（試料８および９）これらの０．５％水溶液の粘度、２５℃の１Ｎ硝酸ナトリウム水溶液中での還元粘度、カチオン当量値とカチオン保持率を実施例１と同様に評価した。この結果を表２に示す。
【００４４】
【比較例１】
架橋剤を添加しないこと以外は実施例１と同様な方法で架橋性水溶性イオン性高分子粉末を得た。（比較１）この重合物の０．５％水溶液の粘度、２５℃の１Ｎ硝酸ナトリウム水溶液中での還元粘度、カチオン当量値とカチオン保持率を実施例１と同様に評価した。この結果を表２に示す。
【００４５】
【比較例２〜３】
架橋剤の種類と添加量を表１に示すように変えた以外は、実施例１と同様な方法で架橋性水溶性カチオン性高分子粉末を得た。（比較２および３）これらの０．５％水溶液の粘度、２５℃の１Ｎ硝酸ナトリウム水溶液中での還元粘度、カチオン当量値とカチオン保持率を実施例１と同様に評価した。この結果を表２に示す。
【００４６】
【比較例４】
単量体の種類と組成を表１に示すように変え、さらに架橋剤を添加しないこと以外は実施例１と同様な方法で架橋性水溶性イオン性高分子粉末を得た。（比較４）このものの０．５％水溶液の粘度、２５℃の１Ｎ硝酸ナトリウム水溶液中での還元粘度、カチオン当量値とカチオン保持率を実施例１と同様に評価した。この結果を表２に示す。
【００４７】
【比較例５〜９】
単量体の種類と組成および架橋剤の種類と添加量を表１に示すように変えた以外は、実施例１と同様な方法で架橋性水溶性イオン性高分子粉末を得た。（比較５および６）これらの０．５％水溶液の粘度、２５℃の１Ｎ硝酸ナトリウム水溶液中での還元粘度、カチオン当量値とカチオン保持率を実施例１と同様に評価した。この結果を表２に示す。
【００４８】
【表１】

ＤＭＣ：メタクリロイロキシエチルトリメチルアンモニウムクロライド、ＤＭＱ：アクリロイロキシエチルトリメチルアンモニウムクロライド、ＡＡＭ：アクリルアミド、ＭＢＡＡ：メチレンビスアクリルアミド、ＱＣＬ：本発明一般式（１）で表されるポリカチオン架橋剤、Ｖ−５０：２，２’−アゾビス（２−アミジノプロパン）ジヒドロクロライド、架橋剤添加量：対単量体重量ｐｐｍ、重合開始剤添加量：対単量体重量ｐｐｍ
【００４９】
【表２】

０．５重量％水溶液粘度：ｍＰａ・ｓ、カチオン当量値：ｍｅｑ／ｇ
還元粘度：ｄｌ／ｇ、測定不能は未溶解物が多く測定ができなかったことを示す。
架橋度分類：（イ）は請求項７記載の本発明低架橋度の架橋性水溶性イオン性高分子粉末、（ロ）は請求項８記載の本発明高架橋度の架橋性水溶性イオン性高分子粉末、（ハ）は（イ）、（ロ）のどちらにも属さない（架橋性）水溶性イオン性高分子粉末を示す。
【００５０】
【表１】および
【表２】の結果を考察すると明らかなように、実施例１〜９では本発明のポリカチオン架橋剤を用いており、いずれの架橋剤添加量においても水溶性の高分子が得られた。一方、架橋剤としてメチレンビスアクリルアミドを用いた比較例３と６は僅かな添加量でも、水に不溶なゲル状の粉末となった。また比較例２と５では、水溶性の架橋性イオン高分子粉末が得られたが、比較例３、６よりさらに微量であり、本発明のポリカチオン架橋剤と比較すると、架橋剤の添加量に対する水溶性高分子のゲル化点は１／１０以下の点であるため、架橋剤添加量の調整、すなわち架橋性水溶性高分子の架橋度の調整は非常に難しいと考えられる。
【００５１】
【実施例１２〜１６】
つぎに、本発明のカチオン水溶性架橋高分子粉末の特徴を明らかにするため、都市下水混合生汚泥（ｐＨ５．５６、全ｓｓ分２５，７５０ｍｇ／Ｌ）２００ｍｌに関する脱水試験行った。前記汚泥をポリビ−カ−に採取し、表１中の試料１、試料３、試料５、試料９および試料１１についてそれぞれを対汚泥固形分６０００ｐｐｍ添加し、ビ−カ−移し変え攪拌１０回行った後、Ｔ−１１７９Ｌのナイロン製濾布により濾過し、３０秒後の濾液量を測定した。また濾過した汚泥をプレス圧２ｋｇ／ｍ^２で１分間脱水した。その後、濾布剥離性とケ−キ自己支持性（乾燥ケ−キの硬さ、含水率と関係）を目視によりチェックし、ケ−キ含水率（１０５℃で２０ｈｒ乾燥）を測定した。結果を表３に示す。
【００５２】
【比較例１０〜１３】
実施例１２〜１６と同様な操作により比較１、比較２、比較５及び比較８について試験を行った。結果を表３に示す。
【００５３】
【実施例１７〜２１】
次に都市下水消化汚泥（ｐＨ７．３７、全ｓｓ分１１，２５０ｍｇ／Ｌ）に関する試験を行った。前期汚泥２００ｍｌをポリビ−カ−に採取し、表１中の試料１、試料３、試料５、試料９および試料１１を、それぞれを対汚泥固形分１８，０００ｐｐｍ添加し、ビ−カ−移し変え攪拌１０回行った後、Ｔ−１１７９Ｌのナイロン製濾布により濾過し、３０秒後の濾液量を測定した。また濾過した汚泥をプレス圧２ｋｇ／ｍ^２で１分間脱水した。その後、濾布剥離性とケ−キ自己支持性（乾燥ケ−キの硬さ、含水率と関係）を目視によりチェックし、ケ−キ含水率（１０５℃で２０ｈｒ乾燥）を測定した。結果を表４に示す。
【００５４】
【比較例１４〜１７】
実施例１７〜２１と同様な操作により比較１、比較２、比較５及び比較８について試験を行った。結果を表４に示す。
【００５５】
【表３】

３０秒後濾液量：ｍｌ、ケーキ含水率：質量％
濾布剥離性、ケーキ支持性：◎＞○＞△＞×の順に良好なことを示す。
【００５６】
【表４】

３０秒後濾液量：ｍｌ、ケーキ含水率：質量％
濾布剥離性、ケーキ支持性：○＞△＞×の順に良好なことを示す。
【００５７】
表３、表４の結果を考察すると明らかなように都市下水消化汚泥、都市下水混合生汚泥のいずれも、比較３を除くと水溶性カチオン高分子を架橋することで、３０秒後濾液量、濾布剥離性、ケーキ支持性、ケーキ含水率のいずれも効果が良好な結果であった。本発明で使用するポリカチオン架橋剤を用いた場合、架橋度の区分が高架橋度（ロ）である試料３は汚泥の種類に関わらず特にケーキ含水率が低下した。一方、架橋度の区分が低架橋度（イ）である試料５は特に３０秒後濾水量が多く効果良好であった。しかし、カチオン保持率ａが０．６２であった試料７は試料３と比較すると３０秒後濾水量、濾布剥離性、ケーキ支持性、ケーキ含水率のいずれも効果は劣るものの、架橋剤を用いなかった比較１と比較すると効果同等かそれ以上の効果を示した。カチオン保持率ａが０．５以下である比較３の試料は、３０秒後濾水量、濾布剥離性、ケーキ支持性、ケーキ含水率のいずれも効果が極度に低下した。
【００５８】
一般的にはケーキ含水率が低く、脱水された汚泥の濾液量は多いほうがよいが、必ずしも両方を満たしている必要はなく、脱水機の形状によって要求される性能が異なる。要求される性能により架橋度の調整が必要であるが、本発明のポリカチオンを用いた場合、架橋剤の添加量によりケーキ含水率と濾液量を調整することができ有利である。
【００５９】
【発明の効果】
本発明のカチオン水溶性架橋高分子粉末の製造方法は、一般的にカチオン水溶性架橋高分子が使用できる用途に使用することができる。例えば、各種固液分離用のカチオン性高分子凝集剤、汚泥脱水剤、製紙用歩留向上剤、濾水性向上剤等への応用が期待される。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a crosslinkable water-soluble polymer powder, and more specifically, comprises a specific monomer and a polycationic cross-linking agent as essential components, and optionally (C) a water-soluble anionic vinyl monomer and (D) a water-soluble polymer. After polymerizing a high-concentration aqueous solution composed of a monomer mixture to which at least one selected from a nonionic monomer is added, and obtaining a polymer having a low moisture concentration, finely granulate through an appropriate drying step And a method for producing a crosslinkable ionic water-soluble polymer powder.
[0002]
[Prior art]
Conventionally, a cationic water-soluble polymer is used as a cationic polymer flocculant for dehydration of organic sludge generated by activated sludge treatment. The product shape of the cationic polymer flocculant is various, such as a powdery product, a low-concentration aqueous solution product, an emulsion product, and a suspension product. The powdery product is characterized in that the active ingredient concentration is high, the production cost and the transportation cost are low, and the product has excellent stability over time. On the other hand, due to the increase in sludge generation and the deterioration of sludge properties, conventional cationic polymer flocculants have a limited sludge treatment amount, and dry cake moisture content, SS recovery rate, and peeling of cake from filter cloth The processing state is not always satisfactory in terms of properties and the like, and improvement is required. In order to improve the drawbacks of these conventional cationic polymer flocculants, it has been proposed that organic polymer compositions cross-linked using a crosslinking agent such as methylenebisacrylamide are effective for various solid-liquid separations. I have. For example, JP-A-64-85199 and JP-A-2-21887 disclose a sludge dewatering agent using a cross-linking agent such as methylenebisacrylamide, and exhibit excellent points such as a decrease in the moisture content of a dry cake. However, these are all synthesized by reversed-phase emulsion polymerization, and the amount of the crosslinking agent added is also in a low range in order to avoid insolubilization of the product. Furthermore, in order to obtain a powdery product that does not require transportation costs, a method of obtaining a powdery crosslinked product by spray-drying after polymerization by reverse phase emulsion polymerization has been proposed, but the operation at the time of production is complicated and the production cost is high. There is such a problem.
[0003]
[Problems to be solved by the invention]
The method of polymerizing the ion-soluble cross-linked polymer at a high concentration, drying and pulverizing is a method that can be easily imagined by those skilled in the art, but uses a generally used cross-linking agent such as methylenebisacrylamide. When the polymerization is carried out by adding a small amount of a crosslinking agent, it is easily insolubilized and cannot exert its performance as a polymer flocculant. Further, since the amount of the crosslinking agent added is small, there is a problem that it is very difficult to adjust the degree of crosslinking so as to exhibit the performance as a crosslinking polymer flocculant. Against this background, there is a demand for high performance and low cost polymer flocculants. Accordingly, an object of the present invention is to develop a method for producing a crosslinkable ionic water-soluble polymer powder which can be easily produced at a low cost and high performance.
[0004]
[Means for Solving the Problems]
The present inventor has conducted intensive studies to solve the above-mentioned problems, and as a result, (A) a water-soluble cationic vinyl monomer and (B) a water-soluble polycation crosslinking agent represented by the following general formula (1) as essential components. Appropriately polymerizing a high-concentration aqueous solution comprising a monomer mixture to which at least one selected from (C) a water-soluble anionic vinyl monomer and (D) a water-soluble nonionic monomer is added, The above-mentioned problem can be solved by a cross-linkable ionic water-soluble polymer powder obtained by evaporating the water content of the aqueous solution by the heat of polymerization at the time and obtaining a polymer having a low water content, and then appropriately subjecting it to a fine drying step. And reached the present invention.
Embedded image

General formula (1)
Embedded image
Where A is

General formula (2)
(R ₁ , R ₂ : Hydrogen, an alkyl group having 1 to 3 carbon atoms or a benzyl group. However, when it is hydrogen, it may be partially substituted by A in the general formula [1]. R ₃ : Hydrogen or methyl group, R ₄ , R ₅ : An alkyl group having 1 to 3 carbon atoms, R ₆ : An alkylene group having 2 to 4 carbon atoms or a hydroxy-substituted alkylene group, n: an integer of 0 to 70, B: -O- or NH-, X ⁻ Is an anion. )
[0005]
The invention according to claim 2 is the crosslinkable ionic water-soluble polymer powder according to claim 1, wherein the aqueous solution is in a range of 40 to 95% by weight.
[0006]
The invention according to claim 3 is characterized in that the monomer mixture is composed of (A) 5 to 100 mol% of a water-soluble cationic vinyl monomer as a composition of (A), (C) and (D), and (C) a water-soluble anion. (A), (C) and (D) as long as the polymer after polymerization has a water solubility of 0 to 50 mol% and (D) a water-soluble nonionic monomer of 0 to 95 mol%. 3. The crosslinkable ionic water-soluble polymer powder according to claim 1, wherein (B) a water-soluble polycationic crosslinking agent is added to the powder.
[0007]
The invention according to claim 4 is the crosslinkable ionic water-soluble polymer powder according to claims 1 to 3, wherein n in the general formula (1) is 1 to 50.
[0008]
The invention according to claim 5 is characterized in that the crosslinkable water-soluble polymer has a range of 0.1 to 20.0 dl / g when the intrinsic viscosity is measured in a 1N aqueous solution of sodium nitrate at 25 ° C. The crosslinkable ionic water-soluble polymer powder according to claim 1.
[0009]
The invention of claim 6 is directed to the total weight of the (A) water-soluble cationic vinyl monomer, the (C) water-soluble anionic vinyl monomer and the (D) water-soluble nonionic monomer. The crosslinkable ionic water-soluble polymer powder according to any one of claims 1 to 5, wherein the polycationic crosslinking agent (B) is contained in an amount of 5 to 20,000 ppm.
[0010]
The invention of claim 7 is based on the total weight of (A) the water-soluble cationic vinyl monomer, (C) the water-soluble anionic vinyl monomer, and (D) the water-soluble nonionic monomer. (B) when the polycationic crosslinking agent is in the range of 5 to 2,000 ppm, the cation retention a expressed by the following formula (2) is in the range of 0.9 <a ≦ 1.0. The crosslinkable ionic water-soluble polymer powder according to claim 1.
a = b / c Equation (2)
Here, b is the cation equivalent value of the cross-linkable water-soluble polymer, and c is the theoretical value of the cation equivalent of the water-soluble polymer when the monomers excluding the (B) polycation cross-linking agent are polymerized in the same composition.
[0011]
The invention of claim 8 is based on the total weight of (A) the water-soluble cationic vinyl monomer, (C) the water-soluble anionic vinyl monomer, and (D) the water-soluble nonionic monomer. (B) when the polycationic crosslinking agent is in the range of 5 to 20,000 ppm, the cation retention a expressed by the following formula (2) is in the range of 0.5 ≦ a ≦ 0.9. The crosslinkable ionic water-soluble polymer powder according to claim 1.
a = b / c Equation (2)
[0012]
The invention of claim 9 comprises (A) a water-soluble cationic vinyl monomer and (B) a water-soluble polycationic crosslinking agent represented by the general formula (1) as essential components, and (C) a water-soluble anionic A high-concentration aqueous solution composed of a monomer mixture to which at least one selected from a vinyl monomer and (D) a water-soluble nonionic monomer is added is polymerized, and the water content of the aqueous solution is reduced by the heat of polymerization. This is a method for producing a crosslinkable ionic water-soluble polymer powder, which comprises evaporating to obtain a polymer having a low water content, and then appropriately subjecting the polymer to a fine drying step.
[0013]
According to a tenth aspect of the present invention, the crosslinkable ionic water-soluble polymer powder according to any one of the first to eighth aspects is dissolved into an aqueous solution, added to the organic sludge after the biological treatment, mixed, and then dehydrated by a dehydrator. A method for using a crosslinkable ionic water-soluble polymer powder characterized by the following.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
The crosslinkable ion water-soluble polymer powder of the present invention comprises (A) a water-soluble cationic vinyl monomer and (B) a polycationic cross-linking agent represented by the following general formula (1) as essential components. After obtaining a polymer by polymerizing a high-concentration aqueous solution comprising a monomer mixture to which at least one selected from a water-soluble anionic vinyl monomer and (D) a water-soluble nonionic monomer is added It can be manufactured by appropriately granulating through a drying step. As a method for refining, any method generally known to those skilled in the art can be used. For example, a method in which suspension polymerization is carried out in the presence of a dispersant and a dispersion medium and spray drying, a method in which dispersion polymerization is carried out in a poor solvent in the presence of a dispersant and drying, a method in which an aqueous solution is polymerized at a high concentration, and then intensive drying and grinding Method and the like. Considering the production cost and the ease of production, a method of polymerizing an aqueous solution at a high concentration, followed by drying and pulverization is preferred.
[0015]
When polymerizing the crosslinkable ion water-soluble polymer powder of the present invention, the monomer concentration in the aqueous solution at the time of polymerization is in the range of 40 to 95% by weight, preferably in the range of 70 to 95% by weight. . If the amount is less than 40% by weight, a large amount of energy and work are required for the drying step after polymerization, and unnecessary costs are required. Further, in the polymerization reaction of the present invention, when the aqueous solution polymerization is performed at a concentration of 70% by weight or more, it is advantageous in a drying step of removing water by utilizing heat of polymerization. At a concentration of 95% by weight or more, it is not only difficult to produce a high molecular weight cationic water-soluble crosslinked polymer, but also unnecessary steps and costs are required for the concentration and purification steps of the monomer, which is disadvantageous.
[0016]
Conventionally, in a method for producing a polymer powder by directly pulverizing a polymer after high-concentration polymerization, it has been general that a crosslinking agent is not added and polymerization is performed. For this reason, in this method, when a conventional crosslinking agent such as N, N-methylenebisacrylamide is added and polymerized, a crosslinking reaction proceeds too much, and in many cases, a polymer gel is formed, and a water-soluble polymer is formed. It was very difficult to get. That is, it is possible to obtain a water-soluble polymer by adding a crosslinking agent of 1 to several ppm by weight per monomer, and it is possible to stably produce a water-soluble polymer having a desired degree of crosslinking even if possible. It is almost impossible to do.
In that regard, the polycationic crosslinking agent used in the present invention has a very wide range of addition amount when producing a water-soluble polymer, and it is easy to control the degree of crosslinking. For example, a water-soluble polymer can be produced by changing production conditions even when 5 to 20,000 ppm by weight per monomer is added.
[0017]
Next, the polycationic crosslinking agent used in the present invention will be described. The polycationic crosslinking agent reacts (E) epihalohydrin with (F) ammonia, a primary amine, or a secondary amine, and (G) a tertiary amino group-containing acrylic monomer, and reacts the terminal of the reaction product. At least two have a vinyl group. (E) The epihalohydrin is not particularly limited, and examples thereof include epichlorohydrin, epibromohydrin, epiiodohydrin and the like. One of these components (E) can be used alone, or two or more of them can be used in combination. Of these epihalohydrins, epichlorohydrin is preferred.
[0018]
As the component (F), ammonia, primary amine and secondary amine can be used alone, respectively, ammonia and primary amine, ammonia and secondary amine, primary amine and secondary amine Can be used in combination, or the three components of ammonia, primary amine and secondary amine can be used in combination. The primary amine is not particularly limited, and examples thereof include methylamine, ethylamine, n-propylamine, and isopropylamine. These primary amines can be used alone or in combination of two or more. Among these primary amines, preferred are methylamine and ethylamine. The secondary amine is not particularly limited, and examples thereof include dimethylamine, diethylamine, dipropylamine, methylethylamine, methylpropylamine, and dibenzylamine. Among these secondary amines, dimethylamine, diethylamine and methylethylamine are preferred.
[0019]
The tertiary amino group-containing acrylic monomer (G) is not particularly limited, and may be, for example, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N, N-dimethylaminobutyl (Meth) acrylamide, N, N-diethylaminobutyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-methylethylaminopropyl (meth) Acrylamide, N, N-methylethylaminoethyl (meth) acrylate and the like can be mentioned. One of these components (F) can be used alone, or two or more of them can be used in combination. Among these monomers, N, N-dimethylaminopropyl acrylamide is used as the component (C) of the present invention because it has higher alkali hydrolysis resistance than a tertiary amino group-containing acrylic monomer having an ester bond in the molecule. (F) It is preferable as a tertiary amino group-containing acrylic monomer.
[0020]
The polycationic crosslinking agent used in the present invention has at least two terminal groups having a vinyl group. The other terminal structure is not particularly limited, and may be an amino group, a secondary amine structure, a tertiary amine structure, a halohydrin structure, a glycidyl group, a hydroxypropyl group, or the like. The number n of the structural units represented by the general formula (1) can be arbitrarily adjusted by a ratio of the component (F) to the component (E), but n is preferably 1 or more and 70 or less, and more preferably. Is 1 or more and 50 or less. In general, the reactant of the component (E) and the component (F) is a mixture of polymers having different molecular weights. The reactant having n of 0 has high reactivity as a crosslinking agent, and the water-soluble crosslinking of the present invention When used in the production of a polymer, the polymer tends to be insoluble, which is inconvenient. It is difficult to produce a polycationic cross-linking agent having n of 71 or more, and in order to produce a reactant having n of 50 or more, a condition that a large amount of residual monomer remains is required. Is not preferable in a system having a large value.
[0021]
The water-soluble polycationic crosslinking agent used in the present invention can be produced by reacting the component (E) with the components (F) and (G). The method for producing the water-soluble polycationic crosslinking agent of the present invention is not particularly limited. For example, the component (E) is charged into a reactor, the component (F) is dropped, and the component (E) and the component (F) are reacted. The reaction can be performed by adding the component (G). A preferred method is to charge component (E) into a reactor, drop component (F), react component (E) with component (F), and then add component (G) to react. Mixing the components (F) and (G) is inconvenient because of the Michael addition reaction. Further, by charging the component (E) into the reactor first, the terminal of the cationic polymer obtained by reacting the component (E) with the component (F) tends to have a glycidyl group and / or halohydrin structure. , (G). The molar ratio of the component (F) to the component (E) is appropriately selected depending on the desired properties, structure, molecular weight and the like of the crosslinking agent, but is generally in the range of 0.25 to 1.20. When the molar ratio of the component (F) to the component (E) is 0.25 or less, the component (E) remains. When the molar ratio of the component (F) to the component (E) is 1.20 or more, a halohydrin structure and / or a glycidyl group are present at the terminal of the cationic polymer obtained by the reaction between the component (E) and the component (F). Not react with component (G).
[0022]
The molar ratio of component (G) to component (E) is not particularly limited, but is preferably in the range of 0.24 or less. When the molar ratio of the component (G) to the component (E) is more than 0.24, the component (G) remains in the polycationic crosslinking agent. Since the component (E) and the component (F) react easily, a cationic polymer can be obtained. The reaction can also be carried out by adding an alkali catalyst such as sodium hydroxide in a molar ratio of 1.0 or less to epihalohydrin. The range of the temperature at which the reaction is carried out is appropriately selected depending on the desired properties, structure, molecular weight and the like of the crosslinking agent, but is generally in the range of 10 to 90 ° C, preferably 20 to 60 ° C. If the temperature at which the reaction is carried out is not higher than 20 ° C., the reaction rate is too slow to be practical, and if it is higher than 60 ° C., the terminal halohydrin structure of the cationic polymer obtained by the reaction of the components (E) and (F) is hydrolyzed. It will not be possible to react with the component (G). The reaction time depends on the reaction temperature and the like, but usually 24 hours or less is sufficient.
[0023]
The water-soluble cationic vinyl monomer used for producing the crosslinkable ionic water-soluble polymer powder of the present invention is used together with the anionic monomer or water-soluble nonionic monomer used for copolymerization. There is no particular limitation as long as it is a polymerizable water-soluble cationic vinyl monomer. For example, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N, N-dimethylaminobutyl (Meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-methylethylaminopropyl (meth) Tertiary amino group-containing vinyl such as acrylamide and N, N-methylethyl (meth) acrylate Reaction of a monomer or an inorganic or organic acid salt such as hydrochloric acid, sulfuric acid or acetic acid, or a tertiary amino group-containing vinyl monomer with a quaternizing agent such as methyl chloride, benzyl chloride or epichlorohydrin Quaternary ammonium salt, vinylimidazoline, 2-vinylpyridine, 4-vinylpyridine, dimethyldiallylammonium-based monomer such as diallyldimethylammonium chloride, diallylmethylbenzylammonium chloride, and component (C) And a macromonomer which is a by-product of the polycationic crosslinking agent. One or more of these water-soluble cationic vinyl monomers can be used. As the water-soluble nonionic monomer, any copolymerizable one can be used, but acrylamide is most preferable.
[0024]
When producing the amphoteric water-soluble polymer, in addition to the water-soluble cationic vinyl monomer and the water-soluble nonionic vinyl monomer, a water-soluble anionic vinyl represented by the general formula (3) is further added. The monomers are copolymerized. For example, a sulfone group or a carboxyl group may be used, and both may be used in combination. Examples of the sulfone group-containing monomer include vinylsulfonic acid, vinylbenzenesulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid. Examples of the carboxyl group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, maleic acid and p-carboxystyrene.
[0025]
The copolymer mole% of the water-soluble cationic vinyl monomer, the water-soluble nonionic vinyl monomer and the water-soluble cationic vinyl monomer in the cross-linkable water-soluble ionic polymer,
It looks like this: That is, in the case of a crosslinkable water-soluble cationic polymer, the content of the water-soluble cationic vinyl monomer is 5 to 100 mol% and the water-soluble non-ionic vinyl monomer is 0 to 95 mol%. 20 to 100 mol% of a water-soluble vinyl monomer and 0 to 80 mol% of a water-soluble nonionic vinyl monomer. In the case of a crosslinkable water-soluble amphoteric polymer, 5 to 100 mol% of a water-soluble cationic vinyl monomer, 0 to 90 mol% of a water-soluble nonionic vinyl monomer, and a water-soluble anionic vinyl monomer 5 to 50 mol%, preferably 20 to 100 mol% of a water-soluble cationic vinyl monomer, 0 to 80 mol% of a water-soluble nonionic vinyl monomer, and 10 to 50 mol% of a water-soluble anionic vinyl monomer. Mol%. In addition, when a high cation density is required, such as a sludge dehydrating agent, the water-soluble cationic vinyl monomer is generally selected from 50 to 100 mol%, 0 to 50 mol% of the nonionic vinyl monomer.
[0026]
When polymerizing the cationic water-soluble crosslinked polymer of the present invention, any of radical polymerization initiators generally used for polymerization of water-soluble polymers can be used as the radical polymerization initiator. These initiators may be oil-soluble or water-soluble, and can be polymerized by any of azo, peroxide, redox, and photoradical polymerization initiation systems initiated by irradiation with visible light or ultraviolet light. It is. For example, examples of the oil-soluble azo-based initiator include 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexanecarbonitrile), and 2,2′-azobis (2-methylbutyronitrile). 2,2'-azobis (2-methylpropionate), 4,4-azobis (4-methoxy-2,4dimethyl) valeronitrile and the like, which are dissolved in a water-miscible solvent and added. Examples of the water-soluble azo initiator include 2,2′-azobis (amidinopropane) dichloride and 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] Hydrogen chloride, 4,4′-azobis (4-cyanovaleric acid) and the like.
[0027]
Examples of the redox system include a combination of ammonium peroxodisulfate with sodium sulfite, sodium hydrogen sulfite, trimethylamine, tetramethylethylenediamine, and the like. Examples of peroxides include ammonium or potassium peroxodisulfate, hydrogen peroxide, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, succinic peroxide, t-butylperoxy 2-ethylhexanoate and the like. be able to. Examples of the photo-radical polymerization initiator include benzoin esters such as benzoin ethyl ester, benzoin isopropyl ester, and benzoin isobutyl ester; and one-component systems such as acetophenones such as 2,2-diethoxyacetophenone; , Benzophenone, anthraquinone, thioxanthone and other aromatic ketones and hydrogen donors such as N-methyl-N, N-diethanolamine. Examples of the hydrogen donor include amines such as N-methyl-N, N-diethanolamine, alcohols such as isopropyl alcohol, and thiols such as 2-mercaptoethanol. Further, radiation polymerization capable of generating radicals in the absence of an initiator can also be performed.
[0028]
The concentration of the polymerization initiator is usually in the range of 5 to 50,000 ppm based on the weight of the monomer for the azo compound, and the peroxide and the reducing agent of the redox initiator are both 5 to 5 based on the weight of the monomer. In the case of the photo-radical polymerization initiator, the weight is in the range of 5 to 50,000 ppm with respect to the weight of the monomer in the one-component system, and in the case of the two-component system, both the aromatic ketone and the hydrogen donor are in the weight of the monomer. In the range of 5 to 50,000 ppm by weight.
[0029]
The polymerization reaction is carried out under an inert gas atmosphere at a reaction temperature of 15 to 100 ° C, and preferably in a range of 20 to 90 ° C. When the reaction temperature is lower than 20 ° C., the polymerization rate is slow and inefficient, and when the reaction temperature is higher than 90 ° C., the reaction rate is high, and an unfavorable reaction such as branching of the polymer chain tends to occur.
[0030]
The crosslinkable water-soluble ionic polymer of the present invention obtained as described above has a cationic unit structure in a side chain when polymerized in the presence of the water-soluble polycationic crosslinker used in the present invention. Produce a graft copolymer. Alternatively, it is a crosslinked polymer having the structure of a block copolymer having the same cationic structure between crosslinking points. That is, a water-soluble ionic polymer having a graft structure or a block structure having a structural unit of a condensate of epihalohydrin and an amine as a raw material in the case of producing a water-soluble polycationic cross-linking agent with a side chain or a cross-linking point. Become.
[0031]
The intrinsic viscosity of the crosslinkable water-soluble ionic polymer of the present invention in a 1N aqueous sodium nitrate solution at 25 ° C. varies depending on the required properties of the cationic water-soluble polymer, reaction conditions and intended use. It is in the range of 0.1 to 20 dl / g, and when used as a flocculant, it is 1 to 20 dl / g, preferably 2 to 15 dl / g.
[0032]
In the crosslinkable water-soluble ionic polymer of the present invention, the water-soluble polycationic crosslinking agent is a total of a water-soluble cationic vinyl monomer, a water-soluble nonionic vinyl monomer and a water-soluble anionic vinyl monomer. It is preferably contained in an amount of 5 to 20,000 ppm by weight based on the weight. When the amount of the water-soluble polycationic crosslinking agent is 5 ppm or less, the effect of crosslinking to the ionic water-soluble polymer does not appear. When the amount is 20,000 ppm or more, not only the adjustment of the degree of crosslinking is difficult, but also the performance decreases due to an increase in the insoluble content. This leads to an increase in manufacturing costs and is disadvantageous.
[0033]
The crosslinkable water-soluble ionic polymer using the crosslinking agent in the present invention can be classified into two types based on its physical properties. The first case is when the molecular weight of the crosslinkable water-soluble ionic polymer is relatively high. In this case, the degree of crosslinking in the crosslinkable water-soluble ionic polymer, that is, the number of crosslinking points in the polymerization chain, is a case where the degree of crosslinking is small. In this case, it is a so-called cross-linkable water-soluble ionic polymer (1) having a low degree of cross-linking, which is polymerized by adding a cross-linking agent in an amount of 5 to 2000 ppm based on the total weight of the water-soluble vinyl monomer.
[0034]
The other case is when the molecular weight of the crosslinkable water-soluble ionic polymer is relatively low. In this case, the degree of crosslinking in the crosslinkable water-soluble ionic polymer is high. In this case, it is a so-called crosslinkable water-soluble ionic polymer (2) having a high degree of crosslinking, which is polymerized by adding a crosslinking agent of 100 to 20,000 ppm based on the total weight of the water-soluble vinyl monomer.
[0035]
Usually, the cationic or amphoteric water-soluble polymer can be measured for the cation equivalent value by a colloid titration method or the like. Generally, a crosslinkable water-soluble ionic polymer is measured to have a lower cation equivalent value than a water-soluble ionic polymer that is not cross-linked, and the higher the amount of the crosslinking agent added and the higher the degree of crosslinking, the higher the cation equivalent. Values tend to be measured low. In the present invention, the cationic water-soluble polymer (1) having a low degree of cross-linking and the cationic water-soluble polymer (2) having a high degree of cross-linking are classified according to the cation retention a represented by the formula (2).
a = b / c Equation (2)
Here, b is the cation equivalent value of the cationic water-soluble crosslinked polymer, and c is the theoretical cation equivalent value of the cationic water-soluble polymer having the same composition but not containing the crosslinking agent.
[0036]
According to a seventh aspect of the present invention, in the production method according to the first to sixth aspects, when the weight is in the range of 5 to 2,000 ppm with respect to the total weight of the water-soluble monomer, the expression is represented by Formula (2). Wherein the cation retention a is in the range of 0.9 <a ≦ 1.0. This crosslinkable water-soluble ionic polymer is applied to the crosslinkable water-soluble ionic polymer (1) having a low degree of crosslinking.
[0037]
The invention according to claim 8 of the present invention provides the method according to claims 1 to 6, wherein a water-soluble polycationic crosslinking agent is added in a range of 100 to 20,000 ppm based on the total weight of the water-soluble monomer. A method for producing a crosslinkable water-soluble ionic polymer powder, wherein the cation retention a represented by (2) is in the range of 0.5 ≦ a ≦ 0.9. Also preferably, the range is 0.8 ≦ a ≦ 0.9. This cationic water-soluble crosslinked polymer is used for the cationic water-soluble polymer (2) having a high degree of crosslinking. When the cation retention ratio a is lower than 0.8, the flocculation performance, the sludge dewatering performance, and the like are reduced when used as a sludge dewatering agent as compared with those having a cation retention ratio of 0.8 or more. Further, when it is lower than 0.5, there is almost no effect on coagulation and dewatering of sludge.
[0038]
The crosslinkable water-soluble ionic polymer powder of the present invention can be used, for example, as a sludge dewatering agent. Applicable sludge is excess sludge generated during biological treatment of paper wastewater, chemical industrial wastewater, food industry wastewater, or organic sludge such as raw sludge, mixed raw sludge, excess sludge, digestive sludge, etc. However, the most suitable sludges are mixed raw sludge and digested sludge of municipal sewage. The amount of the ionic polymer of the present invention is 0.1 to 3.0% by weight, preferably 0.2 to 2.0%, based on the solid content of sludge.
[0039]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.
[0040]
(Synthesis Example of Crosslinking Agent) In a four-neck separable flask equipped with a thermometer, a stirrer, and a dropping funnel, 146.6 g of epichlorohydrin was charged, and 123.8 g of a 50% by weight aqueous solution of dimethylamine was added at 40 to 45 ° C. For 2 hours, and reacted at 45 ° C. for 1 hour after completion of the dropwise addition. As a result of a colloid titration, the conversion of dimethylamine was 100.0%. As a result of neutralization titration of the amine, the content of the tertiary amine was 1% or less. When this was measured by gas chromatography, residual epichlorohydrin was not detected. After the reaction, 21.0 g of dimethylaminopropylacrylamide was added and reacted at 25 ° C. for 15 hours. 36.5 g of ion-exchanged water was added, and a light yellow transparent water-soluble polycationic crosslinking agent 327 of 70.0% by weight concentration was added. 0.9 g was obtained. As a result of neutralization titration of the amine, the tertiary amine was found to be 8.5%. The molecular weight of this product was measured by gel permeation chromatography, and the weight average molecular weight in terms of polyacrylamide was 1,460. Its cation equivalent value was 6.52 meq / g.
[0041]
Embodiment 1
In a container, 100 mol% of methacryloyloxyethyltrimethylammonium chloride (25.0 g of an 80% by weight aqueous solution) and a water-soluble polycationic crosslinker synthesized in a crosslinker synthesis example are 10 ppm by weight based on the weight of methacryloyloxyethyltrimethylammonium chloride. (0.2 g of a 0.1% by weight aqueous solution), and 2,2′-azobis (2-amidinopropane) dihydrochloride was added to 0.1% by weight (10% by weight) based on the weight of methacryloyloxyethyltrimethylammonium chloride. After adding 0.2 g of an aqueous solution, the mixture was stirred to obtain a monomer solution. This solution was polymerized at 50 ° C. for 2 hours under a nitrogen atmosphere. After the polymerization, it was taken out of the polybeaker and dried at 100 ° C. for 15 hours. After drying, the mixture was pulverized into a powder to obtain 21.2 g of a crosslinkable water-soluble cationic polymer powder. (Sample 1) The viscosity of a 0.5% aqueous solution of this was measured with a Brookfield viscometer. Further, at 25 ° C. in a 1N aqueous solution of sodium nitrate, solutions having concentrations of 0.2, 0.1, and 0.05 g / dl were prepared,
After measuring the reduced viscosity with an Ostwald viscometer, the limiting viscosity was determined by extrapolating to a concentration of 0. The cation equivalent value was measured by colloid titration. Further, the cation holding ratio represented by the formula (2) was calculated from the cation equivalent value of the crosslinkable water-soluble polymer and the theoretical value of the cation equivalent of a cationic water-soluble polymer having the same composition and containing no crosslinking agent. Table 2 shows the results.
[0042]
[Examples 2 to 7]
Crosslinkability was obtained in the same manner as in Example 1 except that the amounts of the polycationic crosslinker synthesized in the crosslinker synthesis example and 2,2′-azobis (2-amidinopropane) dihydrochloride were changed to the amounts shown in Table 1. A water-soluble ionic polymer powder was obtained. (Samples 2 to 7) The viscosities of these 0.5% aqueous solutions, reduced viscosities in a 1N aqueous sodium nitrate solution at 25 ° C., cation equivalent values and cation retention were evaluated in the same manner as in Example 1. Table 2 shows the results.
[0043]
Embodiments 8 to 11
Example 1 Except that the kinds and compositions of the monomers, the polycationic cross-linking agent synthesized in the cross-linking agent synthesis example, and the added amount of 2,2′-azobis (2-amidinopropane) dihydrochloride were changed to the amounts shown in Table 1. In the same manner as in Example 1, a crosslinkable water-soluble ionic polymer powder was obtained. (Samples 8 and 9) The viscosities of these 0.5% aqueous solutions, reduced viscosities in a 1N aqueous sodium nitrate solution at 25 ° C., cation equivalent values and cation retention were evaluated in the same manner as in Example 1. Table 2 shows the results.
[0044]
[Comparative Example 1]
A crosslinkable water-soluble ionic polymer powder was obtained in the same manner as in Example 1 except that no crosslinking agent was added. (Comparative 1) The viscosity of a 0.5% aqueous solution of this polymer, the reduced viscosity in a 1N aqueous sodium nitrate solution at 25 ° C., the cation equivalent value and the cation retention were evaluated in the same manner as in Example 1. Table 2 shows the results.
[0045]
[Comparative Examples 2-3]
A crosslinkable water-soluble cationic polymer powder was obtained in the same manner as in Example 1, except that the type and amount of the crosslinking agent were changed as shown in Table 1. (Comparative Examples 2 and 3) The viscosities of these 0.5% aqueous solutions, reduced viscosities in a 1N aqueous sodium nitrate solution at 25 ° C., cation equivalent values and cation retention were evaluated in the same manner as in Example 1. Table 2 shows the results.
[0046]
[Comparative Example 4]
A crosslinkable water-soluble ionic polymer powder was obtained in the same manner as in Example 1 except that the type and composition of the monomer were changed as shown in Table 1, and that no crosslinking agent was further added. (Comparative 4) The viscosity of a 0.5% aqueous solution, the reduced viscosity in a 1N aqueous sodium nitrate solution at 25 ° C., the cation equivalent value and the cation retention were evaluated in the same manner as in Example 1. Table 2 shows the results.
[0047]
[Comparative Examples 5 to 9]
A crosslinkable water-soluble ionic polymer powder was obtained in the same manner as in Example 1, except that the type and composition of the monomer and the type and amount of the crosslinking agent were changed as shown in Table 1. (Comparative Examples 5 and 6) The viscosities of these 0.5% aqueous solutions, reduced viscosities in a 1N aqueous sodium nitrate solution at 25 ° C., cation equivalent values and cation retention were evaluated in the same manner as in Example 1. Table 2 shows the results.
[0048]
[Table 1]

DMC: methacryloyloxyethyltrimethylammonium chloride, DMQ: acryloyloxyethyltrimethylammonium chloride, AAM: acrylamide, MBAA: methylenebisacrylamide, QCL: polycationic crosslinking agent represented by the general formula (1) of the present invention, V- 50: 2,2'-azobis (2-amidinopropane) dihydrochloride, the amount of the crosslinking agent added: based on the weight of the monomer, and the amount of the polymerization initiator added: the weight of the monomer based on the ppm.
[0049]
[Table 2]

0.5% by weight aqueous solution viscosity: mPa · s, cation equivalent value: meq / g
Reduced viscosity: dl / g, unmeasurable means that the amount of undissolved material was large and could not be measured.
Crosslinking degree classification: (A) is a low crosslinkable water-soluble ionic polymer powder of the present invention according to claim 7, and (B) is a high crosslinkable water soluble ionic high powder of the present invention according to claim 8. The molecular powder, (c) indicates a (crosslinkable) water-soluble ionic polymer powder that does not belong to either (a) or (b).
[0050]
Table 1 and
As is apparent from the results shown in Table 2, the polycationic crosslinking agents of the present invention were used in Examples 1 to 9, and water-soluble polymers were obtained regardless of the amount of the crosslinking agent added. On the other hand, Comparative Examples 3 and 6 using methylene bisacrylamide as a cross-linking agent turned into a water-insoluble gel-like powder even with a small addition amount. In Comparative Examples 2 and 5, a water-soluble crosslinkable ionic polymer powder was obtained, but the amount was smaller than those in Comparative Examples 3 and 6, and compared with the polycationic crosslinker of the present invention, the amount of the crosslinker added Since the gel point of the water-soluble polymer is 1/10 or less, it is considered to be very difficult to adjust the amount of the crosslinking agent added, that is, to adjust the degree of crosslinking of the cross-linkable water-soluble polymer.
[0051]
Embodiments 12 to 16
Next, in order to clarify the characteristics of the cationic water-soluble crosslinked polymer powder of the present invention, a dehydration test was conducted on 200 ml of municipal sewage mixed raw sludge (pH 5.56, total ss content: 25,750 mg / L). The sludge was collected in a polybeaker, and 6000 ppm of the solid content with respect to the sludge was added to each of Sample 1, Sample 3, Sample 5, Sample 9, and Sample 11 in Table 1, and the beaker was transferred and stirred 10 times. After that, the solution was filtered through a T-1179L nylon filter cloth, and the filtrate amount after 30 seconds was measured. The filtered sludge is pressed at a pressure of 2 kg / m. ² For 1 minute. Thereafter, the releasability of the filter cloth and the self-supporting property of the cake (the relationship between the hardness of the dried cake and the water content) were visually checked, and the water content of the cake (dried at 105 ° C. for 20 hours) was measured. Table 3 shows the results.
[0052]
[Comparative Examples 10 to 13]
Tests were performed for Comparative 1, Comparative 2, Comparative 5 and Comparative 8 by the same operation as in Examples 12 to 16. Table 3 shows the results.
[0053]
Examples 17 to 21
Next, a test on municipal sewage digested sludge (pH 7.37, total ss content: 11,250 mg / L) was performed. 200 ml of the sludge was collected in a polybeaker, and Samples 1, 3, 5, 9, and 11 shown in Table 1 were added to each of the solids with a solid content of 18,000 ppm and transferred to a beaker. After stirring 10 times, the mixture was filtered with a T-1179L nylon filter cloth, and the filtrate amount after 30 seconds was measured. The filtered sludge is pressed at a pressure of 2 kg / m. ² For 1 minute. Thereafter, the releasability of the filter cloth and the self-supporting property of the cake (the relationship between the hardness of the dried cake and the water content) were visually checked, and the water content of the cake (dried at 105 ° C. for 20 hours) was measured. Table 4 shows the results.
[0054]
[Comparative Examples 14 to 17]
Tests were performed for Comparative 1, Comparative 2, Comparative 5 and Comparative 8 by the same operation as in Examples 17 to 21. Table 4 shows the results.
[0055]
[Table 3]

After 30 seconds, the filtrate volume: ml, cake water content: mass%
Filter cloth releasability, cake supportability: Good is shown in the order of ×>○>△> ×.
[0056]
[Table 4]

After 30 seconds, the filtrate volume: ml, cake water content: mass%
Filter cloth releasability, cake supportability: Good in the order of △>△> ×.
[0057]
As is clear from the results of Tables 3 and 4, all of the municipal sewage digested sludge and the municipal sewage mixed raw sludge were crosslinked with the water-soluble cationic polymer except for Comparative Example 3, so that the amount of filtrate after 30 seconds, All of the filter cloth release properties, cake supportability, and cake moisture content were good results. In the case where the polycationic crosslinking agent used in the present invention was used, Sample 3 in which the degree of crosslinking was high (B) had a particularly low cake moisture content regardless of the type of sludge. On the other hand, in Sample 5, in which the degree of crosslinking was low (A), the amount of drainage was particularly large after 30 seconds, and the effect was good. However, Sample 7 having a cation retention a of 0.62 was inferior in all of the drainage amount, filter cloth releasability, cake supportability and cake moisture content after 30 seconds compared to Sample 3, but the crosslinking agent was not used. As compared with Comparative Example 1 which was not used, the effect was the same or more. In the sample of Comparative Example 3 in which the cation retention a was 0.5 or less, the effects of the drainage amount, filter cloth releasability, cake supportability, and cake moisture content were extremely reduced after 30 seconds.
[0058]
In general, it is better that the cake has a low water content and the filtrate of the dewatered sludge is large, but it is not always necessary to satisfy both, and the required performance differs depending on the shape of the dehydrator. It is necessary to adjust the degree of crosslinking depending on the required performance. However, when the polycation of the present invention is used, the water content of the cake and the amount of the filtrate can be advantageously adjusted by the amount of the crosslinking agent added.
[0059]
【The invention's effect】
The method for producing a cationic water-soluble crosslinked polymer powder of the present invention can be generally used for applications in which a cationic water-soluble crosslinked polymer can be used. For example, application to various cationic polymer flocculants for solid-liquid separation, sludge dewatering agents, retention improvers for papermaking, drainage improvers, and the like are expected.

Claims (10)

(A) a water-soluble cationic vinyl monomer and (B) a water-soluble polycation crosslinking agent represented by the following general formula (1) as essential components, and (C) a water-soluble anionic vinyl monomer and (D) A) polymerizing a high-concentration aqueous solution comprising a monomer mixture to which at least one selected from water-soluble nonionic monomers is added, and evaporating the water content of the aqueous solution by the heat of polymerization during the polymerization; A cross-linkable ionic water-soluble polymer powder obtained by obtaining a polymer of the above, followed by an appropriate drying step to obtain fine particles.

General formula (1)
Where A is

General formula (2)
(R ₁ , R ₂ : hydrogen, an alkyl group having 1 to 3 carbon atoms or a benzyl group. However, when it is hydrogen, it may be partially substituted by A in the general formula (1). R ₃ : Hydrogen or a methyl group, R ₄ , R ₅ : an alkyl group having 1 to 3 carbon atoms, R ₆ : an alkylene group or a hydroxy-substituted alkylene group having 2 to 4 carbon atoms, n: an integer of 0 to 70, B: -O- or -NH-, X ^- is an anion). The crosslinkable ionic water-soluble polymer powder according to claim 1, wherein the aqueous solution is in a range of 40 to 95% by weight. The monomer mixture contains (A) 5 to 100 mol% of a water-soluble cationic vinyl monomer as a composition of (A), (C) and (D), and (C) a water-soluble anionic vinyl monomer 0 to 50 mol%, (D) 0 to 95 mol% of a water-soluble nonionic monomer, and (B) water-soluble to (A), (C) and (D) as long as the polymer after polymerization keeps water solubility. The crosslinkable ionic water-soluble polymer powder according to claim 1 or 2, further comprising a water-soluble polycationic crosslinking agent. 4. The crosslinkable ionic water-soluble polymer powder according to claim 1, wherein n in the general formula (1) is 1 to 50. 5. The crosslinkable water-soluble polymer according to claim 1, wherein the intrinsic viscosity is 0.1 to 20.0 dl / g when measured in a 1N aqueous sodium nitrate solution at 25 ° C. Ionic water-soluble polymer powder. With respect to the total weight of (A) the water-soluble cationic vinyl monomer, (C) the water-soluble anionic vinyl monomer and (D) the water-soluble nonionic monomer, The crosslinkable ionic water-soluble polymer powder according to any one of claims 1 to 5, wherein the cationic crosslinker is contained in an amount of 5 to 20,000 ppm. (B) polycation based on the total weight of (A) the water-soluble cationic vinyl monomer, (C) the water-soluble anionic vinyl monomer and (D) the water-soluble nonionic monomer When the crosslinking agent is in the range of 5 to 2,000 ppm, the cation retention a expressed by the following formula (2) is in the range of 0.9 <a ≦ 1.0. The crosslinkable ionic water-soluble polymer powder according to the above.
a = b / c Equation (2)
Here, b is the cation equivalent value of the cross-linkable water-soluble polymer, and c is the theoretical value of the cation equivalent of the water-soluble polymer when the monomers excluding the (B) polycation cross-linking agent are polymerized in the same composition. (B) polycation based on the total weight of (A) the water-soluble cationic vinyl monomer, (C) the water-soluble anionic vinyl monomer and (D) the water-soluble nonionic monomer When the crosslinking agent is in the range of 5 to 20,000 ppm, the cation retention a represented by the following formula (2) is in the range of 0.5 ≦ a ≦ 0.9. The crosslinkable ionic water-soluble polymer powder according to the above.
a = b / c Equation (2) (A) a water-soluble cationic vinyl monomer and (B) a water-soluble polycationic crosslinking agent represented by the general formula (1) as essential components, and (C) a water-soluble anionic vinyl monomer and (D) A) polymerizing a high-concentration aqueous solution comprising a monomer mixture to which at least one selected from water-soluble nonionic monomers is added, and evaporating the water content of the aqueous solution by the heat of polymerization during the polymerization; A method for producing a crosslinkable ionic water-soluble polymer powder, which comprises obtaining a polymer of the above, and then appropriately subjecting it to a fine drying step. A crosslinkable ion, comprising dissolving the crosslinkable ionic water-soluble polymer powder according to claim 1 to form an aqueous solution, adding to and mixing with the organic sludge after biological treatment, and then dehydrating with a dehydrator. Of water-soluble water-soluble polymer powder.