JP2004115473A - Production method for unsaturated quaternary ammonium salt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an unsaturated quaternary ammonium salt by the quaternization of an aminoalkyl (meth)acrylate with an alkyl halide, wherein a reaction solvent to be used is not limited and the unreacted alkyl halide is efficiently recovered and recycled. <P>SOLUTION: After the quaternization of the aminoalkyl (meth)acrylate with the alkyl halide, a gas containing the unreacted alkyl halide in a gas phase is brought into contact with the aminoalkyl (meth)acrylate in a liquid state; thus, the unreacted alkyl halide is absorbed by the (meth)acrylate. The resultant absorption liquid is recycled as a raw material for the quaternization. <P>COPYRIGHT: (C)2004,JPO

Description

（式中、Ｒ^１は水素原子またはメチル基を示し、ｎは２または３を示す。）
【００１３】
【化５】

（式中、Ｒ^２はメチル基またはエチル基を示し、Ｘは塩素、臭素、ヨウ素のいずれかの原子を示す。）
【００１４】
【化６】

（式中、Ｒ^１は水素原子またはメチル基を示し、Ｒ^２はメチル基またはエチル基を示し、ｎは２または３を示し、Ｘは塩素、臭素、ヨウ素のいずれかの原子を示す。）
【００１５】
【課題を解決するための手段】
本発明の第一は、前記式（１）で表される（メタ）アクリル酸アミノアルキルエステルと前記式（２）で表されるハロゲン化アルキルとを４級化反応させて前記式（３）で表される不飽和第４級アンモニウム塩を製造する方法において、４級化反応の終了後、気相部の未反応の前記ハロゲン化アルキルを含むガスと液体の前記式（１）で表される（メタ）アクリル酸アミノアルキルエステルとを接触させて未反応の前記ハロゲン化アルキルを吸収させ、得られた吸収液を４級化反応の原料として再利用する不飽和第４級アンモニウム塩の製造方法である。
【００１６】
本発明において、前記（メタ）アクリル酸アミノアルキルエステルと接触させた後の気相部のガスは、反応終了後の４級化反応液の残る反応容器内に戻すことが好ましい。
【００１７】
本発明において、前記（メタ）アクリル酸アミノアルキルエステルと接触させた後の気相部のガスは、反応終了後の４級化反応液に吹込むことが好ましい。
【００１８】
本発明において、前記（メタ）アクリル酸アミノアルキルエステルと接触させる気相部の未反応の前記式（２）で表されるハロゲン化アルキルを含むガス中の酸素濃度は、０．１〜１６容量％が好ましい。
【００１９】
本発明は、前記式（１）で表される（メタ）アクリル酸アミノアルキルエステルがアクリル酸ジメチルアミノエチルまたはメタクリル酸ジメチルアミノエチルの場合に好適である。
【００２０】
また本発明は、前記式（２）で表されるハロゲン化アルキルが、塩化メチルまたは塩化エチルの場合に好適である。
【００２１】
本発明の第二は、前記式（１）で表される（メタ）アクリル酸アミノアルキルエステルと前記式（２）で表されるハロゲン化アルキルとの４級化反応を行うための反応容器と、前記反応容器内気相部の未反応の前記ハロゲン化アルキルを含むガスと液体の前記式（１）で表される（メタ）アクリル酸アミノアルキルエステルを接触させて未反応の前記ハロゲン化アルキルを吸収させる気液接触が可能な吸収装置とを有する不飽和第４級アンモニウム塩の製造装置である。
【００２２】
【発明の実施の形態】
以下に本発明について詳細に説明する。本発明の不飽和第４級アンモニウム塩の製造方法で原料として使用する（メタ）アクリル酸アミノアルキルエステルは、前記式（１）で表される（メタ）アクリル酸アミノアルキルエステル（以下、（メタ）アクリル酸アミノアルキルエステルと言う。）である。具体的には、アクリル酸ジメチルアミノエチルエステル、メタクリル酸ジメチルアミノエチルエステル、アクリル酸ジメチルアミノプロピルエステル、およびメタクリル酸ジメチルアミノプロピルエステルである。原料として２種類以上の（メタ）アクリル酸アミノアルキルエステルの混合物を使用してもよい。（メタ）アクリル酸アミノアルキルエステルの品質は特に限定されず、工業用に市販されている低純度のものでも利用可能であるが、製品品質の観点から純度の高いものが好ましい。また、前記式（２）で表されるハロゲン化アルキルおよび／または目的製品である不飽和第４級アンモニウム塩を含んだ（メタ）アクリル酸アミノアルキルエステルも好適である。このような（メタ）アクリル酸アミノアルキルエステルとしては、例えば後述する本発明のハロゲン化アルキルの吸収工程で発生する吸収後の吸収液等が使用できる。
【００２３】
原料として使用するハロゲン化アルキルは、前記式（２）で表されるハロゲン化アルキル（以下、ハロゲン化アルキルと言う。）である。具体的には、塩化メチル、塩化エチル、臭化メチル、臭化エチル、ヨウ化メチル、およびヨウ化エチルである。原料として２種類以上のハロゲン化アルキルの混合物を使用してもよい。ハロゲン化アルキルの品質は特に限定されず、工業用に市販されている低純度のものでも利用可能であるが、製品品質の観点から純度の高いものが好ましい。
【００２４】
本発明では、（メタ）アクリル酸アミノアルキルエステルをハロゲン化アルキルと４級化反応させて前記式（３）で表される不飽和第４級アンモニウム塩（以下、不飽和第４級アンモニウム塩と言う。）を製造する。４級化反応は、回分式、連続式の何れの方法でも実施できる。以下、回分式で４級化反応を行う場合について説明する。
【００２５】
（メタ）アクリル酸アミノアルキルエステルとハロゲン化アルキルの仕込み比率は特に限定されず適宜決めることができる。通常、ハロゲン化アルキルの使用量（反応容器に導入する量）は、（メタ）アクリル酸アミノアルキルエステル１モルに対して１モル以上が好ましく、１．０１モル以上がより好ましい。また、ハロゲン化アルキルの使用量は、（メタ）アクリル酸アミノアルキルエステル１モルに対して１０モル以下が好ましく、１．３モル以下がより好ましい。
【００２６】
４級化反応の溶媒としては、アセトニトリル、アセトン等の有機溶媒、水、水と有機溶媒の混合溶媒等を用いることができる。不飽和第４級アンモニウム塩は水溶液で使用されることが多いことから、溶媒としては水を用いることが好ましい。
【００２７】
４級化反応は重合防止剤の存在下に行うことが好ましい。重合防止剤としては、例えば、モノメチルハイドロキノン、ハイドロキノン、フェノチアジン、クペロン、ｔ−ブチルカテコール、硫酸銅等が挙げられる。重合防止剤は、１種を用いても、２種以上を併用してもよい。重合防止剤の使用量は適宜決めることができる。反応に使用された重合防止剤を反応後もそのまま製品である不飽和第４級アンモニウム塩の重合防止剤として使用する場合、重合防止剤の使用量は製品中の重合防止剤の許容濃度等により決めればよい。一般に、重合防止剤の使用量は仕込みの（メタ）アクリル酸アミノアルキルエステルと溶媒の合計質量に対して、１００質量ｐｐｍ以上が好ましく、また２００００質量ｐｐｍ以下が好ましい。ただし、不飽和第４級アンモニウム塩中の重合防止剤の許容濃度はその用途により異なる。例えば、凝集剤用ポリマーの原料として使用する不飽和第４級アンモニウム塩水溶液の場合は、１００質量ｐｐｍ以上が好ましく、また２００００質量ｐｐｍ以下が好ましい。
【００２８】
本発明の不飽和第４級アンモニウム塩の製造方法では、反応容器に（メタ）アクリル酸アミノアルキルエステルおよび溶媒、ならびに重合防止剤を適宜仕込んだ後、反応容器内にハロゲン化アルキルを導入して４級化反応を行う。反応条件は特に限定されないが、例えば特許文献１〜３に記載されている公知の条件等を採用することができる。
【００２９】
反応容器内気相部の酸素濃度は、酸素含有ガスを適宜使用して、通常０．１〜１６容量％、好ましくは１〜１０容量％、特に好ましくは４〜８容量％とする。気相部の酸素濃度を１６容量％以下とすることにより、ハロゲン化アルキルの爆発を抑制することができる。気相部の酸素濃度の調整は、（メタ）アクリル酸アミノアルキルエステルを仕込む前、（メタ）アクリル酸アミノアルキルエステルを仕込んだ後でハロゲン化アルキルを導入前、ハロゲン化アルキルの導入と同時、４級化反応途中から選ばれる少なくとも１つの時期で行えばよいが、ハロゲン化アルキルの導入前が好ましい。酸素濃度の調整に使用する酸素含有ガスとしては、例えば、空気、純酸素、空気を酸素以外のガスで希釈したもの、純酸素を酸素以外のガスで希釈したもの等が挙げられる。酸素以外のガスとしては、例えば、窒素、アルゴン等の不活性ガス等が挙げられる。
【００３０】
反応容器内の気相部に酸素を存在させないことも可能であるが、気相部に酸素を存在させると液相部に酸素が溶解するので液相部、特に不飽和第四級アンモニウム塩の重合抑制に効果がある。一方、気相部の酸素濃度は低いほど（メタ）アクリル酸アミノアルキルエステルと酸素から生成する着色原因物質が少なくなるので高品質の不飽和第４級アンモニウム塩を製造することができる。
【００３１】
ハロゲン化アルキルはガス状または液状の何れの状態で反応容器に導入してもよいが、操作性の点からガス状で導入することが好ましい。ガス状で導入する場合は、反応容器内の気相部または液相中のいずれか、またはその両方に導入する。ハロゲン化アルキルの導入効率の点から、ハロゲン化アルキルは液相中にバブリングして導入し、液相中に溶解させることが好ましい。またハロゲン化アルキルの溶解効率の点から、加圧状態でハロゲン化アルキルを導入することが好ましい。ハロゲン化アルキルの導入圧力（ゲージ圧）は０〜１５００ｋＰａが好ましく、１０〜３００ｋＰａがより好ましい。ハロゲン化アルキルを液状で導入する場合は液相の液面に滴下すればよい。
【００３２】
４級化反応はハロゲン化アルキルの導入と同時に開始する。４級化反応の反応温度は適宜決めることができる。反応温度の下限は、通常０℃以上、好ましくは２０℃以上である。また上限は、通常１００℃以下、好ましくは７０℃以下である。反応温度の制御は、ハロゲン化アルキルの導入前から開始しても、導入後から開始してもよいが、ハロゲン化アルキルの導入後から制御する方が好ましい。
【００３３】
反応圧力（反応容器内気相部の圧力）は適宜決めることができる。反応圧力（ゲージ圧）の下限は、通常−１０１．３ｋＰａ以上、好ましくは−１００ｋＰａ以上、特に好ましくは−５０ｋＰａ以上である。また上限は、通常５０００ｋＰａ以下、好ましくは１５００ｋＰａ以下、特に好ましくは３００ｋＰａ以下である。
【００３４】
反応時間は適宜決めることができる。反応時間の下限は、通常１時間以上、好ましくは２時間以上である。また上限は、通常１２時間以下、好ましくは８時間以下、特に好ましくは６時間以下である。反応時間は長いほど反応熱の除熱が容易になり、短いほど（メタ）アクリル酸エステルの加水分解が起こり難い。
【００３５】
４級化反応の終了後、気相部の未反応のハロゲン化アルキルを含むガス（以下、被吸収ガスとも言う。）と液体の（メタ）アクリル酸アミノアルキルエステル（以下、吸収液とも言う。）とを接触させて未反応のハロゲン化アルキルを吸収液に吸収させる（以下、吸収工程と言う。）。この吸収操作は、反応容器とは別に用意した気液接触が可能な吸収装置を用いて行うことが好ましい。気液接触が可能な吸収装置としては、例えば、気泡攪拌槽、充填塔、棚段塔、気泡塔、スプレー塔、流動充填塔等を挙げることができる。不飽和第４級アンモニウム塩は結晶として得られるため、取扱いの点で吸収装置としては気泡攪拌槽が好ましい。吸収装置は、同種または異なる形式のものを複数用いてもよい。
【００３６】
吸収工程では、ハロゲン化アルキルは（メタ）アクリル酸アミノアルキルエステルと反応し（メタ）アクリル酸アミノアルキルエステルに難溶の不飽和第４級アンモニウム塩になる。不飽和第４級アンモニウム塩を溶解させるため、吸収液には水を加えておくことが好ましい。水の添加量は特に限定されないが、吸収工程で生成する不飽和第４級アンモニウム塩が７０〜８５質量％の水溶液になる量が好ましい。水の量は少ないほど（メタ）アクリル酸アミノアルキルエステルの加水分解が少なくなり、多いほど不飽和第４級アンモニウム塩の析出が少なくなる。吸収液には重合防止剤を加えておくことが好ましい。重合防止剤は４級化反応で説明したものと同様のものが使用できる。
【００３７】
吸収液の温度は適宜決めることができる。この温度の下限は、通常０℃以上、好ましくは２０℃以上である。また上限は、通常１００℃以下、好ましくは７０℃以下である。温度は低いほど不飽和第４級アンモニウム塩等の重合が起き難い。吸収液の温度の制御は、被吸収ガスの導入前から開始しても、導入後から開始してもよいが、被吸収ガスの導入前から制御を開始する方が好ましい。
【００３８】
吸収装置に導入する被吸収ガスの流量は、装置形状等により適宜決めることができる。また吸収装置に導入する被吸収ガスの全体積は、吸収液の体積に対して１倍以上が好ましく、３０倍以上がより好ましい。また６０００倍以下が好ましく、２０００倍以下がより好ましい。
【００３９】
吸収液である（メタ）アクリル酸アミノアルキルエステルは、１６容量％を超える酸素含有ガスと長時間接触すると着色することがある。ハロゲン化アルキルを吸収した吸収液は４級化反応の原料として利用するので、吸収液が着色すると得られる不飽和第４級アンモニウム塩の品質が低下することがある。このため、被吸収ガスを導入する前の吸収装置内の酸素濃度は、好ましくは０．１〜１６容量％、より好ましくは１〜１０容量％、特に好ましくは４〜８容量％とする。同様に、被吸収ガスの酸素濃度は、好ましくは０．１〜１６容量％、より好ましくは１〜１０容量％、特に好ましくは４〜８容量％である。
【００４０】
吸収時間は、吸収装置の形式、吸収液の量、被吸収ガスの量等により異なるので一概に言えないが、吸収装置として気泡攪拌槽を使用した場合、通常１〜１２時間、好ましくは２〜６時間である。吸収時間は短いほど（メタ）アクリル酸アミノアルキルエステルの着色等による経時劣化が少なくなる。
【００４１】
吸収装置内の圧力は適宜決めることができる。吸収効率の観点から常圧または加圧が好ましい。
【００４２】
吸収工程を経た被吸収ガス（以下、吸収後ガスとも言う。）は、後述するように反応容器に導入して反応後の反応液中のハロゲン化アルキルを低減させるのに使用することが好ましい。
【００４３】
ハロゲン化アルキル吸収後の吸収液は４級化反応の原料として利用する。このようにして、吸収された未反応のハロゲン化アルキルは再利用される。４級化反応には吸収液の全量を利用しても、一部だけを利用してもよい。４級化反応は、前記の反応容器と同じものを用いて行うこともできるが、別の反応容器を用いてもよい。後者の方法として、例えば、吸収液が残る吸収装置にハロゲン化アルキルを導入して４級化反応を行う方法を挙げることができる。この方法は吸収装置から反応容器へ液を移動する必要がないので、工程時間が短く、操作が少ないという利点がある。
【００４４】
４級化反応後、反応容器内の液相部（反応液）は、通常、未反応のハロゲン化アルキルを含む不飽和第４級アンモニウム塩の溶液である。本発明では液相部に溶解している未反応のハロゲン化アルキルを低減する（以下、脱ハロゲン化アルキル工程と言う。）ことが好ましい。ハロゲン化アルキルを低減する方法としては、例えば、液相部に各種のガスをバブリングさせて脱気する方法、気相部に各種のガスを導入する方法、気相部を減圧して脱気する方法、およびこれらを組み合わせた方法等が挙げられる。しかし、気相部を減圧する方法ではハロゲン化アルキルと溶解酸素が共沸脱気され、不飽和第４級アンモニウム塩の重合抑制に効果のある溶存酸素が減少することから、ガスをバブリングさせて脱気する方法が好ましい。また、ガスをバブリングさせて脱気する方法は、ハロゲン化アルキルを効率的に低減できるので好ましい。
【００４５】
液相部や気相部に導入するガス（以下、導入ガスとも言う。）としては、例えば、空気、純酸素、空気を酸素以外のガスで希釈したもの、純酸素を酸素以外のガスで希釈したもの等の酸素含有ガス、窒素、アルゴン等の不活性ガス等が使用できる。不飽和第４級アンモニウム塩の重合を抑制するという観点から酸素含有ガスを用いることが好ましい。酸素含有ガスを液相部にバブリングしている状態であれば、液相中の溶存酸素が無くならないので、気相部を減圧にしてもよい。
【００４６】
導入ガスとして酸素含有ガスを用いる場合、酸素以外の成分は不飽和第４級アンモニウム塩の用途等により適宜決めることができる。酸素以外の成分としては、例えば、窒素、アルゴン等の不活性ガス等が挙げられる。酸素含有ガスは系外から全量を新たに導入してもよいが、吸収後ガスを利用することが好ましい。吸収後ガスを利用する場合は、系外から新たに導入するガスと併用することもできる。吸収後ガスには低濃度のハロゲン化アルキルや（メタ）アクリル酸アミノアルキルエステルが含まれることがある。
【００４７】
導入ガスの酸素濃度は、不飽和第４級アンモニウム塩の重合を抑制する観点から、０．１容量％以上が好ましく、１容量％以上がより好ましく、４容量％以上が特に好ましい。また、酸素含有ガスの酸素濃度は、酸素含有ガスとハロゲン化アルキルによる爆鳴気形成を防止し、未反応（メタ）アクリル酸アミノアルキルエステルの経時着色を抑制する観点から、１６容量％以下が好ましく、１０容量％以下がより好ましく、８容量％以下が特に好ましい。
【００４８】
導入ガスとして吸収後ガスを利用する場合、爆発性のハロゲン化アルキルが含まれることがあので、ハロゲン化アルキルの爆発範囲を避けるような酸素濃度を採る必要がある。反応容器と吸収装置が密閉連結されていて、導入ガスとして吸収後ガスだけを利用する場合、被吸収ガスの酸素濃度を０．１〜１６容量％にしておくことで、導入ガスの酸素濃度を爆発範囲外の０．１〜１６容量％にすることができる。
【００４９】
反応容器に導入する導入ガスの流量は、装置形状等により適宜決めることができる。また反応容器に導入する導入ガスの全体積は、反応液の体積に対して１倍以上が好ましく、３０倍以上がより好ましい。また３０００倍以下が好ましく、１０００倍以下がより好ましい。
【００５０】
脱ハロゲン化アルキル工程後、２回目の吸収工程を実施することもできる。以後同様にして、脱ハロゲン化アルキル工程と吸収工程を繰り返し実施してもよい。これにより反応系内のハロゲン化アルキルの殆どを回収することができる。本発明を密閉系で実施すれば、ハロゲン化アルキルは系外に排出されないので大気汚染の防止に効果的である。
【００５１】
以下、図１を用いて本発明の不飽和第４級アンモニウム塩の製造方法に好適な製造装置の一例について説明する。
【００５２】
加圧反応容器１は（メタ）アクリル酸アミノアルキルエステルとハロゲン化アルキルとの４級化反応を行うために使用される。加圧反応容器１は（メタ）アクリル酸アミノアルキルエステル供給ライン２、攪拌機３、気相部のガス（被吸収ガス）を吸収装置に送るライン４、吸収後ガスを導入するライン５、気相部の酸素濃度を調節するための酸素含有ガス供給ライン６、ハロゲン化アルキル供給ライン７、水供給ライン８を備えている。ライン４に設けられたバルブは反応工程では閉止されており、吸収工程では開弁される。ライン５に設けられたバルブは反応工程では閉止されており、吸収工程では吸収後ガスで反応液をバブリングするために適宜開弁される。
【００５３】
加圧吸収装置９は４級化反応の終了後に被吸収ガスをハロゲン化アルキル反応の原料である（メタ）アクリル酸アミノアルキルエステル（吸収液）に接触させて被吸収ガスに含まれる未反応のハロゲン化アルキルを吸収させるために使用される。加圧吸収装置９は吸収液供給ライン１０、攪拌機１１、被吸収ガスを導入するライン１２、吸収後ガスを加圧反応容器１に送るライン５、気相部の酸素濃度を調節するための酸素含有ガス供給ライン１３を備えている。加圧吸収装置７と加圧反応容器１を繋ぐライン５の途中には、吸収後ガスに含まれる（メタ）アクリル酸アミノアルキルエステルが反応液に混入することを防ぐために、吸収後ガスを冷却して回収するトラップ１４が設置されている。
【００５４】
【実施例】
以下、実施例により本発明を具体的に説明するが、本発明はこれらの実施例に限定されるものではない。実施例は図１に記載した不飽和第４級アンモニウム塩の製造装置を用いて行った。実施例において、反応液中の未反応（メタ）アクリル酸アミノアルキルエステルはＨＰＬＣで、副生酸はアクリル酸として水酸化ナトリウム水溶液による滴定で定量した。
【００５５】
［実施例１］
加圧反応容器（内容積は１Ｌ）内を酸素濃度８容量％の酸素含有窒素ガスで置換した後、アクリル酸ジメチルアミノエチルエステル４７２．５ｇ（３．３モル）、水１５９．８ｇおよび重合防止剤としてモノメチルハイドロキノン１．６ｇ（得られると予想されるアクリロイルオキシエチルトリメチルアンモニウムクロライドの８０質量％水溶液に対して２０００質量ｐｐｍ）を仕込んだ。そして、この混合液を撹拌しながら、塩化メチル１６９．１ｇ（３．３５モル）を５時間かけてバブリングさせた。塩化メチルは混合液に吸収され、アクリル酸ジメチルアミノエチルエステルと反応してアクリロイルオキシエチルトリメチルアンモニウムクロライドを生成した。この際の反応温度は３０〜５５℃、反応圧力は−５０〜１５０ｋＰａ（ゲージ圧）であった。得られたアクリロイルオキシエチルトリメチルアンモニウムクロライドの８０質量％水溶液（反応液）は７９８．９ｇであり、気相部と反応液に残る未反応の塩化メチルは２．５ｇであった。４級化反応後、加圧反応容器内の温度は５５℃に保持した。
【００５６】
加圧吸収装置（内容積１Ｌ）内を酸素濃度８容量％の酸素含有窒素ガスで置換した後、吸収液としてアクリル酸ジメチルアミノエチルエステル４７２．５ｇ（３．３モル）と水２．４ｇとモノメチルハイドロキノン１．６ｇ（次回反応で得られると予想されるアクリロイルオキシエチルトリメチルアンモニウムクロライド８０質量％水溶液の質量に対して２０００質量ｐｐｍ）とを仕込んだ。この吸収液を攪拌しながら、加圧反応容器内の気相部のガスを吸収液中に２Ｌ／ｍｉｎの流量でバブリングさせた（吸収工程）。吸収後ガスは加圧反応容器内の液相部中にバブリングさせ、液相部に溶解している塩化メチルを除去した（脱ハロゲン化アルキル工程）。
【００５７】
以後同様にして、吸収工程と脱ハロゲン化アルキル工程を連続的に行い、未反応の塩化メチル２．５ｇを回収した。この操作は４時間で終了した。４級化反応後に加圧反応容器に導入した吸収後ガスの全体積は液相部の体積に対して６００倍であった。また、加圧吸収装置に導入した被吸収ガスの全体積は吸収液の体積に対して１０２１倍であった。
【００５８】
このようにして得られた加圧反応容器内の液相部は、未反応のアクリル酸ジメチルアミノエチルエステル０．１６質量％、酸分０．０６質量％を含むアクリロイルオキシエチルトリメチルアンモニウムクロライド８０質量％水溶液であった。
【００５９】
また、このようにして得られた吸収液は、アクリル酸ジメチルアミノエチルエステル４６５．４ｇ、アクリロイルオキシエチルトリメチルアンモニウムクロライド９．５９ｇ、水２．４ｇおよびモノメチルハイドロキノン１．６ｇ（次回反応で得られると予想されるアクリロイルオキシエチルトリメチルアンモニウムクロライドの８０質量％水溶液の質量に対して２０００質量ｐｐｍ）の混合物であった。
【００６０】
加圧反応容器内の液相部を製品として取り出した後、加圧吸収装置内の吸収液を加圧反応容器に移し、水１５７．４ｇを加えた。そして、塩化メチルの使用量を１６６．６ｇとした以外は初回と同様にして４級化反応と塩化メチルの回収を行った。この結果、得られた製品と吸収液は初回のものと変わりなかった。
【００６１】
【発明の効果】
本発明によれば、前記式（１）で表される（メタ）アクリル酸アミノアルキルエステルと前記式（２）で表されるハロゲン化アルキルとを４級化反応させて前記式（３）で表される不飽和第４級アンモニウム塩を製造する方法において、使用できる反応溶媒に制限がなく、未反応のハロゲン化アルキルを効率良く回収し再利用することができる。
【００６２】
また本発明の不飽和第４級アンモニウム塩の製造装置は、本発明の不飽和第４級アンモニウム塩の製造方法を実施するのに好適である。
【図面の簡単な説明】
【図１】本発明に係る不飽和第４級アンモニウム塩の製造装置の構成を示す概略図。
【符号の説明】
１　　加圧型反応容器
２　　（メタ）アクリル酸アミノアルキルエステル供給ライン
３　　攪拌機
４　　ライン
５　　ライン
６　　酸素含有ガス供給ライン
７　　ハロゲン化アルキル供給ライン
８　　水供給ライン
９　　加圧吸収装置
１０　吸収液供給ライン
１１　攪拌機
１２　ライン
１３　酸素含有ガス供給ライン
１４　トラップ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing an unsaturated quaternary ammonium salt and an apparatus used for the method.
[0002]
[Prior art]
Unsaturated quaternary ammonium salts impart functions such as cationicity, conductivity, water solubility and adhesiveness to polymers obtained by homopolymerization or copolymerization with other monomers (including graft polymerization). Can be. Therefore, unsaturated quaternary ammonium salts are used as coagulants, antistatic agents, soil improvers, conductive processing agents, dye improvers, paper strength enhancers, paper drainage improvers, cosmetics, resin modifiers, etc. Widely used as a raw material monomer.
[0003]
As a method of producing an unsaturated quaternary ammonium salt, a method of quaternizing an aminoalkyl (meth) acrylate with an alkyl halide is known. In this method, unreacted alkyl halide remains in the reaction solution after the completion of the quaternization reaction and in the gas phase of the reactor.
[0004]
For example, Patent Documents 1 and 2 disclose a quaternization of an acrylic monomer such as aminoalkyl (meth) acrylate and a quaternizing agent such as an alkyl halide using water as a solvent in the presence of oxygen. It is described that the reaction is carried out, and the exhaust gas discharged from the reactor in the course of the reaction is sent to another processing device to absorb the quaternizing agent contained in the exhaust gas into the acrylic monomer. It also describes that after the reaction is completed, a large amount of an oxygen-containing gas is used to remove the quaternizing agent from the reaction solution.
[0005]
Patent Document 3 discloses a method for producing a quaternary ammonium salt by quaternizing an amine with an organic halide as a quaternizing agent, wherein an unreacted quaternizing agent after completion of the reaction is used as a reaction solvent. It describes dissolving, recovering, and reusing.
[0006]
[Patent Document 1] JP-A-63-005064
[0007]
[Patent Document 2] Japanese Patent Publication No. 03-502451
[0008]
[Patent Document 3] JP-A-11-279133
[0009]
[Problems to be solved by the invention]
However, in the methods described in Patent Literature 1 and Patent Literature 2, the quaternizing agent contained in the reaction solution is not used at the end of the reaction, and a large amount of the quaternizing agent is removed after the reaction is completed. Since an oxygen-containing gas is separately required, there is a problem that economic efficiency is low.
[0010]
In addition, since unsaturated quaternary ammonium salts are often used as an aqueous solution, water is usually used as a reaction solvent in the reaction of quaternizing an aminoalkyl (meth) acrylate with an alkyl halide. . Since the solubility of the alkyl halide in water is low, it is difficult to apply the method described in Patent Document 3. Further, the method described in Patent Document 3 has a limitation that even if a solvent other than water is used as the reaction solvent, only a solvent having high solubility of the alkyl halide can be selected.
[0011]
Therefore, an object of the present invention is to carry out a quaternization reaction between an aminoalkyl (meth) acrylate represented by the formula (1) and an alkyl halide represented by the formula (2) to obtain a compound represented by the formula (3). An object of the present invention is to provide a method for producing an unsaturated quaternary ammonium salt, which does not limit the reaction solvent that can be used, and to efficiently recover and reuse unreacted alkyl halide. Another object of the present invention is to provide an apparatus for producing an unsaturated quaternary ammonium salt suitable for carrying out this production method.
[0012]
Embedded image

(Where R ¹ Represents a hydrogen atom or a methyl group, and n represents 2 or 3. )
[0013]
Embedded image

(Where R ² Represents a methyl group or an ethyl group, and X represents any one of chlorine, bromine and iodine. )
[0014]
Embedded image

(Where R ¹ Represents a hydrogen atom or a methyl group; ² Represents a methyl group or an ethyl group, n represents 2 or 3, and X represents any atom of chlorine, bromine and iodine. )
[0015]
[Means for Solving the Problems]
The first aspect of the present invention is to carry out a quaternization reaction between the aminoalkyl (meth) acrylate represented by the formula (1) and the alkyl halide represented by the formula (2), and In the method for producing an unsaturated quaternary ammonium salt represented by the formula, after completion of the quaternization reaction, the gas and liquid containing the unreacted alkyl halide in the gas phase are represented by the above formula (1). Production of unsaturated quaternary ammonium salt by contacting the unreacted alkyl halide by contacting it with an aminoalkyl (meth) acrylate and reusing the resulting absorbent as a raw material for a quaternization reaction Is the way.
[0016]
In the present invention, the gas in the gas phase after contact with the aminoalkyl (meth) acrylate is preferably returned to the reaction vessel in which the quaternized reaction solution after the reaction is left.
[0017]
In the present invention, the gas in the gas phase after contact with the aminoalkyl (meth) acrylate is preferably blown into the quaternized reaction solution after the reaction.
[0018]
In the present invention, the oxygen concentration in the gas containing the unreacted alkyl halide represented by the above formula (2) in the gas phase to be brought into contact with the aminoalkyl (meth) acrylate is 0.1 to 16 vol. % Is preferred.
[0019]
The present invention is suitable when the aminoalkyl (meth) acrylate represented by the formula (1) is dimethylaminoethyl acrylate or dimethylaminoethyl methacrylate.
[0020]
Further, the present invention is suitable when the alkyl halide represented by the formula (2) is methyl chloride or ethyl chloride.
[0021]
A second aspect of the present invention is a reaction container for performing a quaternization reaction between the aminoalkyl (meth) acrylate represented by the formula (1) and the alkyl halide represented by the formula (2). Contacting a gas containing the unreacted alkyl halide in the gas phase in the reaction vessel with a liquid aminoalkyl (meth) acrylate represented by the formula (1) to remove the unreacted alkyl halide; This is an apparatus for producing an unsaturated quaternary ammonium salt having an absorbing device capable of gas-liquid contact for absorption.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail. The aminoalkyl (meth) acrylate used as a raw material in the method for producing an unsaturated quaternary ammonium salt of the present invention is an aminoalkyl (meth) acrylate represented by the formula (1) (hereinafter referred to as (meth) acrylate). ) Acrylic acid aminoalkyl ester). Specifically, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, dimethylaminopropyl acrylate, and dimethylaminopropyl methacrylate are used. As a raw material, a mixture of two or more aminoalkyl (meth) acrylates may be used. The quality of the aminoalkyl (meth) acrylate is not particularly limited, and a low-purity product commercially available for industrial use can be used, but a high-purity product is preferred from the viewpoint of product quality. Further, an aminoalkyl (meth) acrylate containing an alkyl halide represented by the formula (2) and / or an unsaturated quaternary ammonium salt as a target product is also suitable. As such an aminoalkyl (meth) acrylate, for example, an absorbing solution after absorption generated in an alkyl halide absorbing step of the present invention described later can be used.
[0023]
The alkyl halide used as a raw material is an alkyl halide represented by the formula (2) (hereinafter, referred to as an alkyl halide). Specifically, methyl chloride, ethyl chloride, methyl bromide, ethyl bromide, methyl iodide, and ethyl iodide. A mixture of two or more alkyl halides may be used as a raw material. The quality of the alkyl halide is not particularly limited, and a low-purity product commercially available for industrial use can be used, but a high-purity product is preferred from the viewpoint of product quality.
[0024]
In the present invention, the aminoalkyl (meth) acrylate is subjected to a quaternization reaction with an alkyl halide to form an unsaturated quaternary ammonium salt represented by the formula (3) (hereinafter referred to as an unsaturated quaternary ammonium salt). Say)). The quaternization reaction can be carried out by any of a batch system and a continuous system. Hereinafter, the case where the quaternization reaction is performed in a batch system will be described.
[0025]
The charge ratio between the aminoalkyl (meth) acrylate and the alkyl halide is not particularly limited and can be determined as appropriate. Usually, the amount of the alkyl halide used (the amount introduced into the reaction vessel) is preferably at least 1 mol, more preferably at least 1.01 mol, per mol of the aminoalkyl (meth) acrylate. The amount of the alkyl halide used is preferably 10 mol or less, more preferably 1.3 mol or less, per 1 mol of the aminoalkyl (meth) acrylate.
[0026]
As a solvent for the quaternization reaction, an organic solvent such as acetonitrile and acetone, water, a mixed solvent of water and an organic solvent, and the like can be used. Since the unsaturated quaternary ammonium salt is often used in an aqueous solution, it is preferable to use water as the solvent.
[0027]
The quaternization reaction is preferably performed in the presence of a polymerization inhibitor. Examples of the polymerization inhibitor include monomethylhydroquinone, hydroquinone, phenothiazine, cuperon, t-butylcatechol, and copper sulfate. One type of polymerization inhibitor may be used alone, or two or more types may be used in combination. The amount of the polymerization inhibitor used can be appropriately determined. When the polymerization inhibitor used in the reaction is used as it is as the polymerization inhibitor of the unsaturated quaternary ammonium salt which is a product even after the reaction, the amount of the polymerization inhibitor used depends on the allowable concentration of the polymerization inhibitor in the product and the like. You just have to decide. In general, the amount of the polymerization inhibitor to be used is preferably at least 100 ppm by mass, more preferably at most 20,000 ppm by mass, based on the total mass of the charged aminoalkyl (meth) acrylate and the solvent. However, the allowable concentration of the polymerization inhibitor in the unsaturated quaternary ammonium salt varies depending on the use. For example, in the case of an aqueous solution of an unsaturated quaternary ammonium salt used as a raw material of a polymer for a flocculant, the amount is preferably 100 ppm by mass or more, and more preferably 20,000 ppm by mass or less.
[0028]
In the method for producing an unsaturated quaternary ammonium salt of the present invention, (meth) acrylic acid aminoalkyl ester, a solvent, and a polymerization inhibitor are appropriately charged into a reaction vessel, and then an alkyl halide is introduced into the reaction vessel. A quaternization reaction is performed. The reaction conditions are not particularly limited. For example, known conditions described in Patent Documents 1 to 3 and the like can be employed.
[0029]
The oxygen concentration in the gas phase portion in the reaction vessel is usually 0.1 to 16% by volume, preferably 1 to 10% by volume, particularly preferably 4 to 8% by volume, using an oxygen-containing gas as appropriate. By setting the oxygen concentration in the gas phase to 16% by volume or less, the explosion of the alkyl halide can be suppressed. Adjustment of the oxygen concentration in the gas phase portion is performed before the introduction of the alkyl halide (alkyl) before charging the aminoalkyl (meth) acrylate, before the introduction of the alkyl halide after charging the aminoalkyl (meth) acrylate, The reaction may be performed at least one time selected during the quaternization reaction, but is preferably performed before the introduction of the alkyl halide. Examples of the oxygen-containing gas used for adjusting the oxygen concentration include air, pure oxygen, air diluted with a gas other than oxygen, pure oxygen diluted with a gas other than oxygen, and the like. Examples of the gas other than oxygen include an inert gas such as nitrogen and argon.
[0030]
Although it is possible to prevent oxygen from being present in the gas phase in the reaction vessel, it is possible to dissolve oxygen in the liquid phase if oxygen is present in the gas phase, so that the liquid phase, particularly the unsaturated quaternary ammonium salt, Effective for inhibiting polymerization. On the other hand, the lower the oxygen concentration in the gas phase, the less the color-causing substance generated from the aminoalkyl (meth) acrylate and oxygen, so that a high-quality unsaturated quaternary ammonium salt can be produced.
[0031]
The alkyl halide may be introduced into the reaction vessel in a gaseous or liquid state, but is preferably introduced in a gaseous state from the viewpoint of operability. When gaseous is introduced, it is introduced into either the gas phase or the liquid phase in the reaction vessel, or both. From the viewpoint of the introduction efficiency of the alkyl halide, the alkyl halide is preferably introduced by bubbling into the liquid phase and dissolved in the liquid phase. Further, from the viewpoint of the dissolution efficiency of the alkyl halide, it is preferable to introduce the alkyl halide in a pressurized state. The introduction pressure (gauge pressure) of the alkyl halide is preferably from 0 to 1500 kPa, more preferably from 10 to 300 kPa. When the alkyl halide is introduced in a liquid state, it may be dropped on the liquid surface of the liquid phase.
[0032]
The quaternization reaction starts simultaneously with the introduction of the alkyl halide. The reaction temperature of the quaternization reaction can be appropriately determined. The lower limit of the reaction temperature is usually 0 ° C or higher, preferably 20 ° C or higher. The upper limit is usually 100 ° C. or lower, preferably 70 ° C. or lower. The control of the reaction temperature may be started before or after the introduction of the alkyl halide, but is preferably controlled after the introduction of the alkyl halide.
[0033]
The reaction pressure (the pressure of the gas phase in the reaction vessel) can be appropriately determined. The lower limit of the reaction pressure (gauge pressure) is usually -101.3 kPa or more, preferably -100 kPa or more, and particularly preferably -50 kPa or more. The upper limit is usually 5,000 kPa or less, preferably 1500 kPa or less, particularly preferably 300 kPa or less.
[0034]
The reaction time can be determined appropriately. The lower limit of the reaction time is usually at least 1 hour, preferably at least 2 hours. The upper limit is usually 12 hours or less, preferably 8 hours or less, particularly preferably 6 hours or less. The longer the reaction time, the easier the heat removal from the reaction heat, and the shorter the reaction time, the less likely the (meth) acrylic acid ester hydrolysis occurs.
[0035]
After completion of the quaternization reaction, a gas containing an unreacted alkyl halide in the gas phase (hereinafter also referred to as a gas to be absorbed) and a liquid aminoalkyl (meth) acrylate (hereinafter also referred to as an absorption liquid). ) To cause the unreacted alkyl halide to be absorbed in the absorbing solution (hereinafter, referred to as an absorbing step). This absorption operation is preferably performed using an absorption device prepared separately from the reaction vessel and capable of gas-liquid contact. Examples of the absorbing device capable of gas-liquid contact include a bubble stirring tank, a packed tower, a plate tower, a bubble tower, a spray tower, a fluidized packed tower, and the like. Since the unsaturated quaternary ammonium salt is obtained as crystals, a bubble stirring tank is preferable as the absorber in terms of handling. A plurality of absorbers of the same type or different types may be used.
[0036]
In the absorption step, the alkyl halide reacts with the aminoalkyl (meth) acrylate to form an unsaturated quaternary ammonium salt which is hardly soluble in the aminoalkyl (meth) acrylate. In order to dissolve the unsaturated quaternary ammonium salt, it is preferable to add water to the absorbing solution. The amount of water to be added is not particularly limited, but is preferably such that the amount of the unsaturated quaternary ammonium salt generated in the absorption step becomes an aqueous solution of 70 to 85% by mass. The smaller the amount of water, the less the hydrolysis of aminoalkyl (meth) acrylate, and the larger the amount of water, the less the unsaturated quaternary ammonium salt precipitates. It is preferable to add a polymerization inhibitor to the absorbing solution. As the polymerization inhibitor, those described in the quaternization reaction can be used.
[0037]
The temperature of the absorbing liquid can be appropriately determined. The lower limit of this temperature is usually 0 ° C. or higher, preferably 20 ° C. or higher. The upper limit is usually 100 ° C. or lower, preferably 70 ° C. or lower. As the temperature is lower, polymerization of the unsaturated quaternary ammonium salt or the like is less likely to occur. The control of the temperature of the absorbing liquid may be started before or after the introduction of the gas to be absorbed, but it is preferable to start the control before the introduction of the gas to be absorbed.
[0038]
The flow rate of the gas to be absorbed introduced into the absorption device can be appropriately determined depending on the device shape and the like. Further, the total volume of the gas to be absorbed introduced into the absorption device is preferably at least 1 times, more preferably at least 30 times the volume of the absorbing liquid. Moreover, it is preferably 6000 times or less, more preferably 2000 times or less.
[0039]
Aminoalkyl (meth) acrylate, which is an absorbing liquid, may be colored when it is brought into contact with an oxygen-containing gas exceeding 16% by volume for a long time. Since the absorbing solution that has absorbed the alkyl halide is used as a raw material for the quaternization reaction, the quality of the unsaturated quaternary ammonium salt obtained when the absorbing solution is colored may decrease. For this reason, the oxygen concentration in the absorber before introducing the gas to be absorbed is preferably 0.1 to 16% by volume, more preferably 1 to 10% by volume, and particularly preferably 4 to 8% by volume. Similarly, the oxygen concentration of the gas to be absorbed is preferably 0.1 to 16% by volume, more preferably 1 to 10% by volume, particularly preferably 4 to 8% by volume.
[0040]
The absorption time cannot be said unconditionally because it differs depending on the type of the absorption device, the amount of the absorption liquid, the amount of the gas to be absorbed, etc., but when a bubble stirring tank is used as the absorption device, usually 1 to 12 hours, preferably 2 6 hours. The shorter the absorption time, the less the deterioration with time due to coloring of the aminoalkyl (meth) acrylate and the like.
[0041]
The pressure in the absorber can be determined as appropriate. Normal pressure or pressurization is preferable from the viewpoint of absorption efficiency.
[0042]
The gas to be absorbed after the absorption step (hereinafter also referred to as “absorbed gas”) is preferably introduced into a reaction vessel and used to reduce alkyl halide in the reaction solution after the reaction, as described later.
[0043]
The absorption liquid after absorption of the alkyl halide is used as a raw material for a quaternization reaction. In this way, the absorbed unreacted alkyl halide is recycled. For the quaternization reaction, the entire amount of the absorbing solution may be used, or only a part thereof may be used. The quaternization reaction can be carried out using the same reaction vessel as described above, but another reaction vessel may be used. As the latter method, for example, a method in which an alkyl halide is introduced into an absorbing device in which an absorbing solution remains to perform a quaternization reaction can be given. This method has the advantage that the process time is short and the number of operations is small because it is not necessary to transfer the liquid from the absorption device to the reaction vessel.
[0044]
After the quaternization reaction, the liquid phase part (reaction liquid) in the reaction vessel is usually a solution of an unsaturated quaternary ammonium salt containing an unreacted alkyl halide. In the present invention, it is preferable to reduce unreacted alkyl halide dissolved in the liquid phase (hereinafter, referred to as a dehalogenated alkyl step). As a method for reducing the alkyl halide, for example, a method of degassing by bubbling various gases in the liquid phase, a method of introducing various gases in the gas phase, and degassing by depressurizing the gas phase And a combination thereof. However, in the method of reducing the pressure in the gas phase, the alkyl halide and dissolved oxygen are azeotropically degassed, and the dissolved oxygen that is effective in suppressing the polymerization of the unsaturated quaternary ammonium salt is reduced. A method of degassing is preferred. Further, a method of degassing by bubbling a gas is preferable because the alkyl halide can be efficiently reduced.
[0045]
Examples of the gas to be introduced into the liquid phase portion or the gas phase portion (hereinafter, also referred to as an introduced gas) include air, pure oxygen, air diluted with a gas other than oxygen, and pure oxygen diluted with a gas other than oxygen. An inert gas such as an oxygen-containing gas, nitrogen, argon or the like can be used. It is preferable to use an oxygen-containing gas from the viewpoint of suppressing polymerization of the unsaturated quaternary ammonium salt. If oxygen-containing gas is being bubbled through the liquid phase, the dissolved oxygen in the liquid phase does not disappear, so the pressure in the gas phase may be reduced.
[0046]
When an oxygen-containing gas is used as the introduction gas, components other than oxygen can be appropriately determined depending on the use of the unsaturated quaternary ammonium salt and the like. Examples of the component other than oxygen include an inert gas such as nitrogen and argon. The entire amount of the oxygen-containing gas may be newly introduced from outside the system, but it is preferable to use the gas after absorption. When the gas after absorption is used, it can be used together with a gas newly introduced from outside the system. The gas after absorption may contain a low concentration of alkyl halide or aminoalkyl (meth) acrylate.
[0047]
From the viewpoint of suppressing the polymerization of the unsaturated quaternary ammonium salt, the oxygen concentration of the introduced gas is preferably 0.1% by volume or more, more preferably 1% by volume or more, and particularly preferably 4% by volume or more. Further, the oxygen concentration of the oxygen-containing gas is preferably 16% by volume or less from the viewpoint of preventing the formation of explosive gas due to the oxygen-containing gas and the alkyl halide and suppressing the coloring with time of the unreacted aminoalkyl (meth) acrylate. It is preferably at most 10% by volume, particularly preferably at most 8% by volume.
[0048]
When the gas after absorption is used as the introduced gas, an explosive alkyl halide may be contained. Therefore, it is necessary to adopt an oxygen concentration that avoids the explosion range of the alkyl halide. When the reaction vessel and the absorption device are hermetically connected and only the gas after absorption is used as the introduced gas, the oxygen concentration of the gas to be absorbed is set to 0.1 to 16% by volume to reduce the oxygen concentration of the introduced gas. It can be 0.1 to 16% by volume outside the explosion range.
[0049]
The flow rate of the introduced gas introduced into the reaction vessel can be appropriately determined depending on the shape of the apparatus and the like. The total volume of the gas introduced into the reaction vessel is preferably at least 1 time, more preferably at least 30 times the volume of the reaction solution. Moreover, it is preferably 3000 times or less, more preferably 1000 times or less.
[0050]
After the dehalogenation alkylation step, a second absorption step may be performed. Thereafter, the dehalogenation alkylation step and the absorption step may be repeatedly performed in the same manner. Thereby, most of the alkyl halide in the reaction system can be recovered. If the present invention is carried out in a closed system, the alkyl halide is not discharged out of the system, which is effective in preventing air pollution.
[0051]
Hereinafter, an example of a production apparatus suitable for the method for producing an unsaturated quaternary ammonium salt of the present invention will be described with reference to FIG.
[0052]
The pressurized reaction vessel 1 is used for performing a quaternization reaction between an aminoalkyl (meth) acrylate and an alkyl halide. The pressurized reaction vessel 1 includes a (meth) acrylic acid aminoalkyl ester supply line 2, a stirrer 3, a line 4 for sending gas in the gas phase (gas to be absorbed) to the absorber, a line 5 for introducing gas after absorption, a gas phase An oxygen-containing gas supply line 6, an alkyl halide supply line 7, and a water supply line 8 for adjusting the oxygen concentration of the section are provided. The valve provided in the line 4 is closed in the reaction step, and is opened in the absorption step. The valve provided in the line 5 is closed in the reaction step, and is appropriately opened in the absorption step for bubbling the reaction solution with the absorbed gas.
[0053]
After the quaternization reaction is completed, the pressure absorption device 9 brings the gas to be absorbed into contact with the aminoalkyl (meth) acrylate (absorbing liquid), which is a raw material for the alkyl halide reaction, and causes unreacted gas contained in the gas to be absorbed. Used to absorb alkyl halides. The pressure absorption device 9 includes an absorption liquid supply line 10, a stirrer 11, a line 12 for introducing a gas to be absorbed, a line 5 for sending the gas after absorption to the pressure reaction vessel 1, and oxygen for adjusting the oxygen concentration in the gas phase. A gas supply line 13 is provided. The gas after absorption is cooled in the middle of the line 5 connecting the pressure absorption device 7 and the pressure reaction vessel 1 in order to prevent the aminoalkyl (meth) acrylate contained in the gas after absorption from being mixed into the reaction solution. A trap 14 is provided for collection.
[0054]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. Examples were carried out using the apparatus for producing unsaturated quaternary ammonium salts shown in FIG. In Examples, unreacted aminoalkyl (meth) acrylate in the reaction solution was quantified by HPLC, and by-product acid was quantified by titration with an aqueous sodium hydroxide solution as acrylic acid.
[0055]
[Example 1]
After replacing the inside of the pressurized reaction vessel (with an internal volume of 1 L) with an oxygen-containing nitrogen gas having an oxygen concentration of 8% by volume, dimethylaminoethyl acrylate (472.5 g (3.3 mol), water (159.8 g) and polymerization prevention) 1.6 g of monomethylhydroquinone (2000 ppm by mass with respect to an 80% by mass aqueous solution of acryloyloxyethyltrimethylammonium chloride expected to be obtained) was charged as an agent. Then, while stirring the mixture, 169.1 g (3.35 mol) of methyl chloride was bubbled over 5 hours. Methyl chloride was absorbed into the mixture and reacted with dimethylaminoethyl acrylate to form acryloyloxyethyltrimethylammonium chloride. At this time, the reaction temperature was 30 to 55 ° C, and the reaction pressure was -50 to 150 kPa (gauge pressure). The obtained 80% by mass aqueous solution (reaction liquid) of acryloyloxyethyltrimethylammonium chloride was 798.9 g, and the unreacted methyl chloride remaining in the gas phase and the reaction liquid was 2.5 g. After the quaternization reaction, the temperature in the pressurized reaction vessel was kept at 55 ° C.
[0056]
After replacing the inside of the pressure absorption device (1 L of internal volume) with an oxygen-containing nitrogen gas having an oxygen concentration of 8% by volume, 472.5 g (3.3 mol) of dimethylaminoethyl acrylate and 2.4 g of water were used as an absorbing solution. 1.6 g of monomethylhydroquinone (2000 ppm by mass with respect to the mass of an aqueous 80% by mass acryloyloxyethyltrimethylammonium chloride expected to be obtained in the next reaction) was charged. While stirring the absorbing solution, the gas in the gas phase in the pressurized reaction vessel was bubbled into the absorbing solution at a flow rate of 2 L / min (absorbing step). After the absorption, the gas was bubbled into the liquid phase in the pressurized reaction vessel to remove methyl chloride dissolved in the liquid phase (dehalogenation alkylation step).
[0057]
Thereafter, similarly, the absorption step and the dehalogenation alkylation step were continuously performed, and 2.5 g of unreacted methyl chloride was recovered. This operation was completed in 4 hours. The total volume of the gas after absorption introduced into the pressurized reaction vessel after the quaternization reaction was 600 times the volume of the liquid phase. The total volume of the gas to be absorbed introduced into the pressure absorption device was 1021 times the volume of the absorption liquid.
[0058]
The liquid phase portion in the pressurized reaction vessel obtained in this manner contains 80% by mass of acryloyloxyethyltrimethylammonium chloride containing 0.16% by mass of unreacted dimethylaminoethyl acrylate and 0.06% by mass of an acid component. % Aqueous solution.
[0059]
In addition, the absorption solution obtained in this manner contained 465.4 g of dimethylaminoethyl acrylate, 9.59 g of acryloyloxyethyltrimethylammonium chloride, 2.4 g of water, and 1.6 g of monomethylhydroquinone (the next reaction). 2000 mass ppm based on the expected mass of an 80% by mass aqueous solution of acryloyloxyethyltrimethylammonium chloride).
[0060]
After taking out the liquid phase portion in the pressurized reaction vessel as a product, the absorbing solution in the pressurized absorption device was transferred to the pressurized reaction vessel, and 157.4 g of water was added. Then, a quaternization reaction and the recovery of methyl chloride were carried out in the same manner as in the first step except that the amount of methyl chloride used was changed to 166.6 g. As a result, the obtained product and the absorbing solution were not different from those of the first time.
[0061]
【The invention's effect】
According to the present invention, the aminoalkyl (meth) acrylate represented by the formula (1) and the alkyl halide represented by the formula (2) undergo a quaternization reaction, and the quaternary reaction is performed by the formula (3). In the method for producing the represented unsaturated quaternary ammonium salt, there is no limitation on the reaction solvent that can be used, and the unreacted alkyl halide can be efficiently recovered and reused.
[0062]
Further, the apparatus for producing an unsaturated quaternary ammonium salt of the present invention is suitable for carrying out the method for producing an unsaturated quaternary ammonium salt of the present invention.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the configuration of an apparatus for producing an unsaturated quaternary ammonium salt according to the present invention.
[Explanation of symbols]
1 Pressurized reaction vessel
2 (Meth) acrylic acid aminoalkyl ester supply line
3 stirrer
4 lines
5 lines
6 Oxygen-containing gas supply line
7 Alkyl halide supply line
8 Water supply line
9 Pressure absorption device
10 Absorbent supply line
11 Stirrer
12 lines
13 Oxygen-containing gas supply line
14 trap

Claims (7)

The quaternization reaction of the aminoalkyl (meth) acrylate represented by the formula (1) and the alkyl halide represented by the formula (2) causes the unsaturated quaternary ammonium represented by the formula (3) In the method for producing a salt, after the quaternization reaction is completed, the gas containing the unreacted alkyl halide in the gas phase is converted into a liquid aminoalkyl (meth) acrylate represented by the formula (1). A method for producing an unsaturated quaternary ammonium salt in which the unreacted alkyl halide is absorbed by contact and the resulting absorbent is reused as a raw material for a quaternization reaction.

(In the formula, R ¹ represents a hydrogen atom or a methyl group, and n represents 2 or 3.)

(In the formula, R ² represents a methyl group or an ethyl group, and X represents any atom of chlorine, bromine, and iodine.)

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a methyl group or an ethyl group, n represents 2 or 3, and X represents any atom of chlorine, bromine, and iodine.) The unsaturated gas according to claim 1, wherein the gas in the gas phase after contacting with the aminoalkyl (meth) acrylate is returned to the reaction vessel in which the quaternized reaction solution after the reaction is completed. A method for producing a quaternary ammonium salt. 3. The unsaturated quaternary ammonium salt according to claim 2, wherein the gas in the gas phase after the contact with the aminoalkyl (meth) acrylate is blown into the quaternized reaction solution after the reaction. Manufacturing method. The unsaturated oxygen-containing compound according to any one of claims 1 to 3, wherein an oxygen concentration in an unreacted gas containing the alkyl halide in a gas phase portion to be brought into contact with the aminoalkyl (meth) acrylate is 0.1 to 16% by volume. A method for producing a quaternary ammonium salt. The method for producing an unsaturated quaternary ammonium salt according to any one of claims 1 to 4, wherein the aminoalkyl (meth) acrylate represented by the formula (1) is dimethylaminoethyl acrylate or dimethylaminoethyl methacrylate. The method for producing an unsaturated quaternary ammonium salt according to claim 1, wherein the alkyl halide represented by the formula (2) is methyl chloride or ethyl chloride. A reaction vessel for performing a quaternization reaction between the aminoalkyl (meth) acrylate represented by the formula (1) and the alkyl halide represented by the formula (2), and a gas phase portion in the reaction vessel Gas-liquid contact is possible in which a gas containing the unreacted alkyl halide is brought into contact with a liquid aminoalkyl (meth) acrylate represented by the formula (1) to absorb the unreacted alkyl halide. An apparatus for producing an unsaturated quaternary ammonium salt having a simple absorption device.

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