JP3850656B2 - Method for producing dehydration reaction product - Google Patents

Description

【００５４】
上記酸触媒の使用量としてはまた、各種の化学製品用途に適用される重合体の製造原料となるエステル化物やアミド化物の有用性や、このような適用用途に要求される基本性能である分散性能等に悪影響を及ぼすことになるゲル状物発生の防止・抑制の点から、反応原料の合計重量に対する酸触媒中の酸の重量の比をＸ（重量％）とし、酸触媒中の水和物及び／又は水溶液として存在する水分の重量の比をＹ（重量％）とした場合に、０＜Ｙ＜１．８１Ｘ−１．６２
の関係式を満足することが好ましい。
【００５５】
上記関係式について具体例を挙げて説明すれば、例えば、パラトルエンスルホン酸一水和物を例にとると、反応原料の合計重量に対するパラトルエンスルホン酸の重量の比がＸ（重量％）であり、反応原料の合計重量に対する一水和物として存在する水分の重量の比がＹ（重量％）であるのであって、決して、酸触媒以外の酸成分として、例えば、原料の（メタ）アクリル酸等や水分すなわちエステル化反応により生ずる反応生成水等は、上記ＸやＹの対象物とはなり得ない。
【００５６】
上記酸触媒の使用量が上記関係式を満足しない場合には、例えば、Ｙが０であると、酸触媒中に水和物及び／又は水溶液として存在する水分が存在しないこととなり、エステル化反応時に反応系内で形成されるゲルの量が増加し、それらを用いて合成されるセメント添加剤用重合体等の用途性能として、例えば、セメント分散能等が低下するおそれがある。また、Ｙ≧１．８１Ｘ−１．６２であると、エステル化反応時に反応系内で形成されるゲルの量が増加し、上記と同様となる。
上記酸触媒の反応系への添加方法としては、一括、連続又は順次行ってもよいが、作業性の面からは、反応槽に、反応原料と共に一括で仕込むことが好ましい。
【００５７】
上記エステル化反応やアミド化反応は、重合禁止剤の存在下で行われることが好ましい。これにより、反応原料中の不飽和カルボン酸とその生成物であるエステル化物及び／又はアミド化物の重合を防止することできる。このような重合禁止剤としては、公知の重合禁止剤が使用でき、特に限定されず、例えば、フェノチアジン、トリ−ｐ−ニトロフェニルメチル、ジ−ｐ−フルオロフェニルアミン、ジフェニルピクリルヒドラジル、Ｎ−（３−Ｎ−オキシアニリノ−１，３−ジメチルブチリデン）アニリンオキシド、ベンゾキノン、ハイドロキノン、メトキノン、ブチルカテコール、ニトロソベンゼン、ピクリン酸、ジチオベンゾイルジスルフィド、クペロン、塩化銅（II）等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。これらの中でも、溶解性の点から、フェノチアジン、ハイドロキノン、メトキノンを用いることが好ましい。これらは、脱水反応工程においても溶剤留去工程においても極めて有効に重合禁止能を発揮することができる点から極めて有用である。
【００５８】
上記重合禁止剤の使用量としては、反応原料であるアルコール、アミン及び酸の合計仕込量を１００重量％とすると、０．００１〜１重量％とすることが好ましい。０．００１重量％未満であると、重合禁止能の発現が充分でなく、反応原料や生成物の重合を有効に防止しにくくなり、１重量％を超えると、エステル化物中に残留する重合禁止剤量が増えるため、品質及び性能が低下するおそれがあり、また、過剰に添加することに見合う効果も得られず、経済的な面から不利となるおそれがある。より好ましくは０．００１〜０．１重量％である。
【００５９】
上記エステル化やアミド化反応においては、脱水溶剤の存在下で脱水反応操作を行うことにより、反応系外に生成水と脱水溶剤とを共沸させ、凝縮液化して生成水を分離除去させながら還流させることにより行うことができる。これにより、エステル化反応やアミド化反応で生成する反応生成水を効率よく共沸できる。このような脱水溶剤としては、水と共沸する溶剤であれば特に限定されず、例えば、ベンゼン、トルエン、キシレン、シクロヘキサン、ジオキサン、ペンタン、ヘキサン、ヘプタン、クロロベンゼン、イソプロピルエーテル等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。これらの中でも、水との共沸温度が１５０℃以下であるものが好ましく、６０〜９０℃であるものがより好ましい。このような脱水溶剤として具体的には、シクロヘキサン、トルエン、ジオキサン、ベンゼン、イソプロピルエーテル、ヘキサン、ヘプタン等が挙げられる。水との共沸温度が１５０℃を超えると、反応時の反応系内の温度管理や留出物の凝縮液化処理等の制御等を含む取り扱い性が低下するおそれがある。
【００６０】
上記脱水溶剤を用いる脱水反応操作において、脱水溶剤の使用量としては、反応原料であるアルコール、アミン及び酸の合計仕込量を１００重量％とすると、０〜１００重量％とすることが好ましい。１００重量％を超えると、過剰に添加することに見合う効果が得られず、また、反応温度を一定に維持するために多くの熱量が必要となり、経済的な面から不利となるおそれがある。より好ましくは、２〜５０重量％である。
【００６１】
上記脱水反応工程において、エステル化反応やアミド化反応は、回分式や連続式いずれの反応操作方法によっても行ない得るが、回分式で行うことが好ましい。また、反応条件としては特に限定されず、反応が円滑に進行する条件であればよいが、例えば、反応温度としては、３０〜１８０℃とすることが好ましい。より好ましくは、６０〜１３０℃であり、更に好ましくは、９０〜１２５℃であり、最も好ましくは、１００〜１２０℃である。３０℃未満であると、脱水溶剤の還流が遅くなり、脱水に時間がかかる他、反応が進行しにくくなるおそれがあり、１８０℃を超えると、反応原料の一部が分解することにより、エステル化物やアミド化物により得られる重合体において、セメント分散性能等の各種用途における分散性能や増粘特性の低下や、反応原料の重合、留出物への反応原料の混入量の増加、エステル化物やアミド化物の性能及び品質の劣化等が生じるおそれがある。
【００６２】
上記反応条件において、反応時間としては、後述するように反応率が７０％以上に達するまでとすることが好ましい。より好ましくは、８０％以上に達するまで、更により好ましくは、９８％以上に達するまでである。通常では、１〜１００時間、好ましくは３〜６０時間である。また、反応圧力としては、常圧又は減圧下のいずれで行ってもよいが、設備面から、常圧下で行うことが好ましい。
【００６３】
上記エステル化反応やアミド化反応の反応率としては、７０％以上となるように設定することが好ましい。７０％未満であると、製造されるエステルやアミドの収率が不充分であり、これを重合原料として得られるセメント添加剤用重合体等の用途性能、すなわちセメント分散能等が低下するおそれがある。より好ましくは、７０〜９９％、更に好ましくは、８０〜９８％である。なお、上記反応率とは、反応原料であるアルコールやアミンの仕込み時及び反応終了時の量の比率であって、例えば、下記測定条件で液体クロマトグラフィー（ＬＣ）により各々のピークの面積として測定することにより、下記式により算出される値（％）である。
【００６４】
【数２】

【００６５】
反応率測定条件
解析装置：Ｗａｔｅｒｓ社製 Ｍｉｌｌｅｎｎｉｕｍ クロマトグラフィーマネージャー（商品名）
検出器：Ｗａｔｅｒｓ社製 ４１０ ＲＩ検出器（商品名）
使用カラム：ＧＬサイエンス社製 イナートシルＯＤＳ−２（内径４．６ｍｍ、長さ２５０ｍｍ）（商品名） ３本
カラム温度：４０℃
溶離液：水８９４６ｇ、アセトニトリル６０００ｇ及び酢酸５４ｇを混合して、３０％水酸化ナトリウム水溶液でｐＨ４．０に調整した溶液を用いる。
流速：０．６ｍｌ／ｍｉｎ
【００６６】
本発明の脱水反応生成物の製造方法では、脱水反応工程において酸触媒を用いた場合には、酸触媒や（メタ）アクリル酸を中和する中和工程を行うことが好ましい。これにより、触媒が活性を失い、エステル化反応やアミド化反応により得られる脱水反応生成物の加水分解が抑制され、重合に関与しない不純物の発生が抑制された結果、重合体の品質や性能の低下を抑制することが可能となる。
【００６７】
上記中和工程の方法としては、例えば、エステル化反応やアミド化反応の終了後、酸触媒を中和剤で中和することにより行う方法が好ましい。
上記中和剤としては、酸触媒を中和できるものであれば特に制限はない。例えば、水酸化ナトリウム、水酸化カリウム、水酸化カルシウム、水酸化リチウム等のアルカリ金属、アルカリ土類金属の水酸化物；炭酸ナトリウム、炭酸カルシウム、炭酸リチウム等のアルカリ金属、アルカリ土類金属の炭酸塩；アンモニア、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン等のアミン類等を挙げらることができ、これらが１種又は２種以上使用される。また、中和剤の形態としては特に限定されず、例えば、アルカリ水溶液の形態とすることが好ましい。
【００６８】
上記中和工程では、酸触媒や（メタ）アクリル酸が中和されることになるが、酸触媒の全部と、（メタ）アクリル酸の一部が中和されるように設定することが好ましい。この場合、中和される（メタ）アクリル酸は、エステル化反応やアミド化反応後の残りの（メタ）アクリル酸を１００重量％とすると、２０重量％以下、好ましくは、０．０１〜５重量％であることが好ましい。なお、酸触媒と（メタ）アクリル酸とでは、酸触媒の方が酸強度が大きいため、酸触媒から中和されることになる。
【００６９】
上記中和工程における中和方法では、脱水溶剤中でエステル化反応やアミド化反応を行う場合には、アルカリと共に多量の水を反応系に添加することが好ましい。すなわち多量の水がない状態では、アルカリが脱水溶剤に難溶であるために濃い状態で系内に浮遊し、このような高濃度のアルカリの浮遊は中和に消費されるまでの長時間にわたって消失せず、エステル化物やアミド化物の加水分解を引き起こすことになる。この場合、水の添加量としては、アルカリの使用形態にもよるが、例えば、４０〜６０重量％のアルカリ水溶液を中和剤として添加する場合には、アルカリ水溶液とは別に、アルカリ水溶液の１重量部に対して、通常５〜１０００重量部とすることが好ましい。より好ましくは、１０〜１００重量部である。５重量部未満であると、アルカリが反応系内で不均一になるおそれがあり、１０００重量部を超えると、生産性を確保するために中和槽が別途必要となる等、生産コストが上昇するおそれがある。
【００７０】
上記中和工程における中和温度としては、例えば、９０℃以下とすることが好ましい。より好ましくは、０〜８０℃である。更により好ましくは２５〜６５℃である。９０℃を超えると、添加される中和剤が加水分解の触媒として作用し、加水分解生成物を多量に生成するようになるおそれがある。８０℃以下であると、加水分解生成物の生成がより充分に抑制されることになるが、０℃未満であると、反応液が粘稠になることに起因して攪拌がしにくくなる他、反応後に水を留去するため所定の温度まで降温するのに長時間を要したり、室温よりも低い温度まで降温するのに新たに冷却手段（装置）を設けたりする必要が生じて生産コストが上昇するおそれがある。
【００７１】
脱水溶剤を重合工程等に利用する場合を除いては、該脱水溶剤を留去することが好ましい。上記溶剤留去工程において、脱水溶剤の留去方法としては特に限定されず、例えば、脱水溶剤のみを留出するようにして留去してもよく、他の適当な添加剤を加えて留去してもよいが、水を用いて脱水溶剤と共沸させて留去することが好ましい。この場合、中和工程が行われたことにより、反応系内に酸触媒やアルカリが実質的に存在しないため、水を加えて昇温しても加水分解反応が起こらない。このような方法により、より低い温度で脱水溶剤を除去することができることになる。
【００７２】
上記留去方法の条件としては、反応系内の脱水溶剤を好適に留出（蒸発）させるように設定すれば特に限定されず、例えば、溶剤留去中の反応槽内の液温（常圧下）としては、水を用いる場合には、通常８０〜１２０℃とすることが好ましい。より好ましくは、９０〜１１０℃である。また、水を用いない場合には、通常８０〜１６０℃とすることが好ましい。より好ましくは、９０〜１５０℃である。上記のいずれも場合にも、上記温度よりも低いと、脱水溶剤を蒸発させるのに充分な温度（熱量）とはならないおそれがあり、上記温度よりも高いと、重合を引き起こすおそれがある他、多くの熱量が大量の低沸点原料の蒸発に消費されるおそれがある。反応槽内の圧力としては、常圧下又は減圧下いずれで行ってもよいが、設備面から、常圧下で行うことが好ましい。
上記溶剤留去工程において用いる装置系としては、脱水反応工程で用いた装置系をそのまま使用することが好ましい。
【００７３】
本発明の脱水反応生成物の製造方法により得られる脱水反応生成物は、各種の重合体、すなわちセメント添加剤や炭酸カルシウム、カーボンブラック、インク等の顔料分散剤、スケール防止剤、石膏・水スラリー用分散剤、石炭・水スラリー（ＣＷＭ）用分散剤、増粘剤等の化学製品に用いられる重合体を製造するための製造原料として好適に適用されることになる。
【００７４】
以下では、脱水反応生成物の製造方法により得られる脱水反応生成物を製造原料としてセメント分散剤用重合体を製造する方法や、該セメント分散剤用重合体を含有するセメント添加剤を製造する方法、該セメント添加剤を使用する方法について説明する。
【００７５】
上記セメント分散剤用重合体としては、得られた脱水反応生成物と不飽和カルボン酸系単量体を必須成分とする単量体を重合して得られるポリカルボン酸系重合体が挙げられる。このようなポリカルボン酸系重合体の重合方法としては、特に制限はなく、例えば、重合開始剤を用いての溶液重合や塊状重合等の公知の重合方法を採用できる。
【００７６】
上記不飽和カルボン酸系単量体としては例えば、（メタ）アクリル酸、クロトン酸、チグリン酸、シトロネル酸、ウンデシレン酸、エライジン酸、エルカ酸、ソルビン酸、リノール酸等の不飽和モノカルボン酸類；マレイン酸、フマル酸、シトラコン酸、メサコン酸、イタコン酸等の不飽和ジカルボン酸類；これらのジカルボン酸とアルコールのモノエステル類等を挙げることができ、それらの一価金属塩、二価金属塩、アンモニウム塩、有機アミン塩を挙げることができる。
【００７７】
ポリカルボン酸系重合体には、必要に応じて不飽和カルボン酸系単量体以外の単量体を共重合させることもできる。この様な単量体としては、（メタ）アクリルアミド、（メタ）アクリルアルキルアミド等の不飽和アミド類；酢酸ビニル、プロピオン酸ビニル等のビニルエステル類；ビニルスルホン酸、（メタ）アリルスルホン酸、スルホエチル（メタ）アクリレート、２−メチルプロパンスルホン酸（メタ）アクリルアミド、スチレンスルホン酸等の不飽和スルホン酸類やそれらの一価金属塩、二価金属塩、アルモニウム塩、有機アミン塩類；スチレン、α−メチルスチレン等の芳香族ビニル類；炭素数１〜１８、好ましくは１〜１５の脂肪族アルコールやベンジルアルコール等のフェニル基を有するアルコールと（メタ）アクリル酸とのエステル類；ポリアルキレングリコールモノ（メタ）アクリレート；ポリアルキレングリコールモノ（メタ）アリルエーテル等が挙げられる。
【００７８】
上記ポリカルボン酸系重合体は、特定の重量平均分子量を有する重合体であることが好ましい。例えば、下記測定条件のゲルパーミエーションクロマトグラフィー（以下、「ＧＰＣ」という）によるポリエチレングリコール換算での重量平均分子量としては、例えば、５００〜５０００００であることが好ましい。５００未満であると、セメント添加剤の減水性能が低下するおそれがあり、５０００００を超えると、セメント添加剤の減水性能、スランプロス防止能が低下するおそれがある。より好ましくは、５０００〜３０００００であり、最も好ましくは８０００〜１０００００の範囲である。
【００７９】
上記ＧＰＣは、溶離液貯蔵槽、溶離液の送液装置、オートサンプラー、カラムオーブン、カラム、検出器、データ処理機等から構成される。例えば、下記の市販の装置を組み合わせることにより測定条件を設定して分子量を測定することができる。
【００８０】
分子量測定条件
機種 ：ＬＣモジュール１ｐｌｕｓ（商品名、ＷＡＴＥＲＳ社製）
検出器：示差屈折計（ＲＩ）４１０示差屈折計（商品名、ＷＡＴＥＲＳ社製）
溶離液：０．０５Ｍ 酢酸ナトリウム、アセトニトリル／イオン交換水＝４０／６０混合液を酢酸でｐＨを６に調整したものを使用する。
溶離液の流量：１．０ｍｌ／ｍｉｎ
カラム：
ＴＳＫ−ＧＥＬ ガードカラム（内径６ｍｍ、長さ４０ｍｍ）
＋ＴＳＫ−ＧＥＬ Ｇ−４０００ＳＷＸＬ（内径７．８ｍｍ、長さ３００ｍｍ）
＋ＴＳＫ−ＧＥＬ Ｇ−３０００ＳＷＸＬ（内径７．８ｍｍ、長さ３００ｍｍ）
＋ＴＳＫ−ＧＥＬ Ｇ−２０００ＳＷＸＬ（内径７．８ｍｍ、長さ３００ｍｍ）
（いずれも商品名、東ソー社製）
カラムオーブンの温度：４０℃
【００８１】
検量線：検量線は、標準試料の分子量や数、ベースラインの引き方、検量線近似式の作製方法等により変化する。このため、以下の条件を設定することが好ましい。
１．標準試料
標準試料には、市販の標準ポリエチレンオキシド（ＰＥＯ）と標準ポリエチレングリコール（ＰＥＧ）を使用する。標準試料には、次の分子量のものを使用することが好ましい。
１４７０、４２５０、７１００、１２６００、２４０００、４６０００、８５０００、２１９３００、２７２５００（合計９点）
これらの標準試料は、以下の点に配慮して選択した。
（１）分子量９００以上の標準試料を７点以上使用する。
（２）分子量９００〜２０００の標準試料を少なくとも１点含む。
（３）分子量２０００〜６００００の標準試料を少なくとも３点含む。
（４）分子量２０００００±３００００の標準試料を少なくとも１点含む。
（５）分子量２７００００±３００００の標準試料を少なくとも１点含む。
【００８２】
２．ベースラインの引き方
分子量の上限：水平で安定なベースラインからピークが立ち上がる点とする。
分子量の下限：主ピークの検出が終了した点とする。
３．検量線の近似式
上記標準試料を用いて作製した検量線（「溶出時間」対「ｌｏｇ分子量」）は３次式の近似式を作製し、これを計算に用いる。
【００８３】
上記ポリカルボン酸系重合体を含有するセメント分散剤では、良好なセメント分散性能及びスランプ保持性能を発揮することができるが、必要により、ポリカルボン酸系重合体以外の公知のセメント添加剤（セメント分散剤）を更に配合してもよい。
【００８４】
上記セメント分散剤ではまた、空気連行剤、セメント湿潤剤、膨張剤、防水剤、遅延剤、急結剤、水溶性高分子物質、増粘剤、凝集剤、乾燥収縮低減剤、強度増進剤、硬化促進剤、消泡剤等を配合することができる。
このようにして得られるセメント分散剤は、セメントや水を含有するセメント組成物として、例えば、ポルトランドセメント、ビーライト高含有セメント、アルミナセメント、各種混合セメント等の水硬セメントや、石膏等のセメント以外の水硬性材料に用いられることになる。
【００８５】
上記セメント分散剤の水硬性材料への添加量としては、従来のセメント分散剤に比較して少量の添加でも優れた効果を発揮することになるが、例えば、水硬セメントを用いるモルタルやコンクリート等に使用する場合には、セメントの重量を１００重量％とすると、０．００１〜５重量％となるような比率の量を練り混ぜの際に添加すればよい。０．００１重量％未満であると、セメント分散剤の作用効果が充分に発揮されないおそれがあり、５重量％を超えると、その効果は実質的に頭打ちとなり、経済性の面からも不利となるおそれがある。より好ましくは、０．０１〜１重量％である。これにより、高減水率の達成、スランプロス防止性能の向上、単位水量の低減、強度の増大、耐久性の向上等の各種の作用効果を奏することになる。
【００８６】
【発明の実施の形態】
本発明の脱水反応生成物の製造方法について、装置構成の一実施形態の概略図を示した図２を用いて説明する。なお、このような実施形態は本発明の代表的な一例であり、本発明の実施形態はこれに限られるものではない。
【００８７】
図２では、先ず所定温度まで昇温して脱水反応工程を行った後、所定温度まで降温して中和工程を行い、次いで所定温度まで昇温し脱水溶剤の溶剤留去工程を行うための装置構成が示されている。このような装置構成では、反応槽１０１内で脱水反応時に生成される反応生成水を含む留出物を留出させ、ゲル状物の発生を防止しながらコンデンサ１２５にて凝縮液化した後に、水分離器１２７にて反応生成水を分離除去し、残りの留出物をポンプ１４２により所定の溶剤循環速度で還流させて反応槽１０１に戻す循環機構が形成されている。このような循環機構では、反応槽１０１上部と向流又は並流接触形式の縦型多管式円管形コンデンサ１２５の塔頂部とが連結管１２３により連結され、コンデンサ１２５の下底部と水分離器１２７の上部とが供給管（配管）１２９により連結されることにより、反応槽１０１と水分離器１２７とが供給管１２９で繋がっている。
以下では、脱水反応としてエステル化反応を行う場合について説明する。
【００８８】
反応槽１０１は、熱交換手段として、温水や加庄スチーム等を熱媒体に使用し得る外部ジャケット１０２が設けられている。また、反応槽１０１内には、反応温度を計測するための温度センサ（図示せず）が適当な数カ所の部位に取り付けられている。このような温度センサは、反応温度を規定の温度に保つために制御部本体（図示せず）に電気的に接続されている。上記装置機構としては、例えば、反応槽１０１に取り付けられたジャケット１０２等が挙げられる。
【００８９】
上記実施形態における水分離器１２７としては、材質をＳＵＳ３０４製とし、その内部には邪魔板１３１が備えられ、邪魔板１３１で区切られた２つの室（Ａ）１３３及び室（Ｂ）１３４が形成されている。この水分離器１２７では、供給管１２９は、室（Ａ）１３３の液相部に開放口を有すると共に、供給管１２９の側面に空けた複数個の穴１６２により気相部にも開放口を有し、かつ、この気相部の開放口が邪魔板１３１と反対方向にある。図２中、水分離器１２７内部の矢印は、開放口からの留出物の流れ方向を示し、供給管１２９の複数個の穴１６２の部分が拡大図で示されている。また、水分離器１２７の下部の径が上部の径よりも細くなっている。更に、脱水溶剤と生成水との界面の検出装置として界面計（Ａ）１３６及び気相部と液相部（脱水溶剤）との気液界面の検出装置として界面計（Ｂ）１３８が設けられ、界面計（Ａ）１３６及び界面計（Ｂ）１３８の内部にゲル化防止剤を作用させている。
【００９０】
上記水分離器ではまた気相部にコンデンサ１２８が取付けられている。水分離器の気相部中の脱水溶剤や揮発性の（メタ）アクリル酸等は、コンデンサ１２８で充分に冷却されるため、系外に放出されることはない。また、コンデンサ１２８には開放口（いわゆるベント）が備えられ、これにより、反応槽を加熱したときにも反応系内の圧力が過剰に上昇することはなく、計器の破損を防止している。
【００９１】
上記水分離器１２７ではまた、コンデンサ１２５で凝縮液化された留出物が貯められる側の室（Ａ）１３３の下部と生成水の処理タンク１３５とが配管１３７により連結され、配管１３７にはコントロールバルブ１４０が備えられ、処理タンク１３５には廃水用の配管１３９が連結されている。水分離器１２７のもう一方の室（Ｂ）１３４の下部は反応槽１０１と配管１４１で連結され、この配管１４１にもコントロールバルブ（図示せず）が備えられ、反応槽１０１内の生成水と共沸する脱水溶剤を貯蔵する脱水溶剤貯蔵タンク１４３と連結された配管１４５が合流（連結）されている。また、合流点の手前（水分離器１２７側）の配管１４１の経路上には循環ポンプ１４２が設置され、合流点の後方（反応槽１０１側）の配管１４１の経路上には流量計１４４が設けられている。更に、該流量計１４４には、計測される流量を積算し、溶剤循環速度を算出するための流量計測システム本体（図示せず）と電気的に接続されている。
【００９２】
上記反応槽１０１には、アルコール原料用のステンレススチール（例えば、ＳＵＳ３０４）製の原料貯蔵タンク１０３、（メタ）アクリル酸原料用の原料貯蔵タンク１０５、酸触媒用の触媒貯蔵タンク１０７、及び、脱水反応後に酸触媒を中和処理するための中和剤（中和剤水溶液）を貯蔵したカーボンスチール（例えば、高炭素鋼）製の中和剤貯蔵タンク１１１が備えられ、それぞれ配管１１３、１１５、１１７及び１２１により連結されている。配管１１７には、ポンプ１６７が設けられている。また、脱水反応時の反応系（反応槽１０１）内の重合を防止するための重合禁止剤を貯蔵した重合禁止剤貯蔵タンク１０９が配管１１９によりポンプ１６９を介して連結されている。
【００９３】
上記原料貯蔵タンク１０５では、（メタ）アクリル酸が重合しやすく、例えば、メタクリル酸では、長期の保存や熱等によっても重合するため、通常では０．１重量％メトキノン等の微量の重合禁止剤が（メタ）アクリル酸に添加されている。また、図２では、常時３０〜４０℃に保温するため、ポンプ１１６を用いた外部ジャケット１５０（保温手段）を有する循環経路１５１が設けられ、（メタ）アクリル酸原料を常に３０〜４０℃に保持して重合しないように循環させるような装置構成となっている。
【００９４】
上記原料貯蔵タンク１０５、配管１１５、ポンプ１１６及び循環経路１５１内部には、腐食性を有する（メタ）アクリル酸による腐食を防止するため、合成樹脂等の耐食性材料によるライニング加工が施されているものを使用することが好ましい。同様に、触媒貯蔵タンク１０７、配管１１７、ポンプ１６７にも酸触媒による腐食を防止するためにテフロン（商品名）、塩化ビニル等合成樹脂等の耐酸性材料によるライニング加工が施されているものを使用することが好ましく、ポンプ１６７にはマグネットポンプを用いることが好ましい。重合禁止剤の貯蔵タンク１６９、ゲル化防止剤の貯蔵タンク１４７、１５９には、攪拌装置を備えている（図示せず）。粉末状の重合禁止剤を溶剤に溶解させる場合には、充分に攪拌を行い、完全に溶解させることが好ましい。しかしながら、何らかの原因で完全に溶解していない重合禁止剤又はゲル化防止剤の溶液を、ポンプ１６０、１６９、１７９で移送すると、ポンプは閉塞を起こし停止することがある。このような事態は、溶解さえ充分であれば起こり得ないことであるが、ポンプ１６０、１６９、１７９には、少々のスラリー状の液体が移送されても滞りなく移送を継続できるポンプが好ましい。また、溶剤に溶解した重合禁止剤又はゲル化防止剤を移送する場合には、テフロン、バイトン（いずれも商品名）等の耐薬性の材料でシールされたポンプを使用することが好ましい。この様な条件を満たすポンプとしては、モーノポンプ（兵神装備社製）に適当なシールを施すのが最適である。また、反応槽１０１の下部には、エステル化反応により反応槽１０１内部に合成されたエステル化物を回収するための配管１５３が連結されている。
【００９５】
上記図２ではまた、コンデンサ１２５におけるゲル状物の発生を抑制するため、コンデンサ１２５の塔頂部には噴霧ノズル１２６が設けられており、この噴霧ノズル１２６は、留出物のゲル化防止用のゲル化防止剤を貯蔵するゲル化防止剤貯蔵タンク１４７と配管１４９によりポンプ１７９を介して連結されている。同様に、反応槽１０１と連結管１２３の接続部付近には、噴霧ノズル（図示せず）が連結管１２３側から反応槽１０１側に向けて噴霧できるように設けられており、この噴霧ノズルは水分離器１２７と配管１４１により連結されている。
【００９６】
上記循環機構の一部は、脱水反応後に、系内（反応槽１０１内）の生成物であるエステル化物を含有する溶液から脱水溶剤を含む留出物を留出し、ゲル状物の発生を防止しながら凝縮液化した後に、脱水溶剤を含む留出物を系外に除去するための循環機構としても利用されている。このような循環機構では、水分離器１２７に、配管１５７を介して、脱水溶媒を減圧吸引により除去するために真空ポンプ（エゼクタ）１５５が取り付けられている。また、上記図２では、留出物中の水相でのゲル化を充分に防止するため、新たにコンデンサ１２５の塔頂部に設けられた噴霧ノズル１２６に、水溶性重合禁止剤を溶かした水溶液（以下、単に「水溶性ゲル化防止剤」ともいう）を貯蔵する水溶性ゲル化防止剤貯蔵タンク１５９が配管１６１により連結されている。
【００９７】
上記図２では、以上の装置構成により、以下に説明するように脱水反応生成物の製造が行われることになる。
先ず、脱水反応工程として、反応槽１０１内部に、各原料貯蔵タンク１０３及び１０５、触媒貯蔵タンク１０７、重合禁止剤貯蔵タンク１０９、並びに、脱水溶剤貯蔵タンク１４３より、配管１１３、１１５、１１７、１１９及び配管１４５を介した配管１４１を通じて、反応原料であるアルコール及び（メタ）アクリル酸、酸触媒、重合禁止剤及び脱水溶剤をそれぞれ所定量を仕込み、適宜設定された反応温度、ジャケット温度、圧力等の反応条件でエステル化反応を行う。これにより逐次生成する生成水は、反応槽１０１内に仕込まれた脱水溶剤と共沸され連結管１２３を通じて留出されることになる。留出されてきたガス流体、すなわち溶剤−水共沸物である留出物は、コンデンサ１２５に通され凝縮液化される。また、上記図２では、ゲル化防止剤貯蔵タンク１４７より配管１４９を通じてコンデンサ１２５の塔頂部に設けられた噴霧ノズル１２６から所定量のゲル化防止剤を連続的に噴霧して、ガス流体や凝縮液化物である留出物と接触させている。
【００９８】
次いで、凝縮液化された留出物は、コンデンサ１２５の下部より供給管１２９を通じて水分離器１２７の室（Ａ）１３３に貯められ、水相（下相）と溶剤相（上相）の２層に分離されることになる。このとき、供給管１２９の開放口が上述したように設定されていることから、水分離器１２７へ供給される留出物の圧力等が変動しても、突沸の発生、界面の検知精度の低下、界面の液ゆれ、ゲル状物の形成等の不具合が充分に抑制されることになる。また、下相の生成水は、配管１３７を通じて逐次抜かれ、生成水の処理タンク１３５に貯められる。このとき、界面計（Ａ）１３６で水相と溶剤相との界面を検知しながら該界面が水分離器１２７の下部の細い部分に保たれるように、配管１３７に備えられたコントロールバルブで水相の抜き取り量（留出量）を調整することにより制御されている。そして、処理タンク１３５内で、必要に応じて、環境基準（廃水基準）値を満足するように化学的又は生物学的に処理された後、配管１３９を通じて、本装置系外に廃水される。一方、室（Ａ）１３３において、ノズル１２６より噴霧されたゲル化防止剤を含有する上相となる溶剤相は、邪魔板１３１をオーバーフローして隣の室（Ｂ）１３４に貯められる。そして、溶剤相はポンプ１４２を介し、配管１４１を通じて所定の溶媒循環速度で還流され反応槽１０１に戻されることになる。このとき、配管１４１に備えられたコントロールバルブやポンプ１４２により溶媒循環速度が調整されることになる。これらの操作において、水分離器１２７が上述した構造であるため、本発明の作用効果を充分に発揮して、製造工程での不具合の発生を抑制すると共に、生成するエステル化物の性能や品質の低下を充分に抑制することが可能となる。このとき一部は反応槽１０１と連結管１２３の接続部付近に設けられた噴霧ノズルを通して噴霧され、反応槽１０１と連結管１２３の接続部付近でのゲル化を防止している。
【００９９】
更に、中和工程として、脱水反応終了後、降温し反応槽１０１の内温（液温）が、例えば、６０℃以下に降温するまで、反応槽１０１の外部ジャケット１０２に冷媒を通じて降温し、その後は所定温度以下を維持するように適宜調整しながら、中和剤貯蔵タンク１１１より配管１２１を通じて反応槽１０１内に、多量の水により所定の濃度まで薄められたアルカリ水溶液（中和剤）を添加することにより酸触媒や（メタ）アクリル酸の一部を部分中和することになる。
【０１００】
上記中和工程が終了後、溶剤留去工程として、常圧下に、反応槽１０１の外部ジャケット１０２に熱媒（加圧スチーム）を通じて所定の温度まで昇温することにより、反応槽１０１内の脱水溶剤及び部分中和処理の際に加えられている水の他、（メタ）アクリル酸等も共沸されて、連結管１２３を通じて留出されることになる。留出されてきたガス状流体である溶剤−水共沸物は、コンデンサ１２５に通され凝縮液化されることになる。
【０１０１】
上記溶剤留去工程において凝縮液化された留出物は、留出した脱水溶剤を反応槽１０１に還流させない以外は、上記脱水反応工程における凝縮液化された留出物と同様に処理されることになる。
上記溶剤留去工程においては、溶剤と共に脱水反応工程に比して多量の水がコンデンサ１２５に入る。重合性化合物が水相側においてゲル化することを防止するため、水溶性ゲル化防止剤貯蔵タンク１５９より配管１６１を通じてコンデンサ１２５の塔頂部に設けられた噴霧ノズル１２６から所定量の水溶性ゲル化防止剤を連続的に滴下して、留出物と接触させることが好ましい。
【０１０２】
上記溶剤留去工程の後、反応槽１０１内に、配管（図示せず）により連結されている水貯蔵タンク（図示せず）又は上水管（図示せず）より調整水を添加して所望の脱水反応生成物の水溶液を得ることになる。得られる脱水反応生成物の水溶液は、配管１５３より回収（貯蔵）される。
【０１０３】
【実施例】
以下に実施例を掲げて本発明を更に詳しく説明するが、本発明は、これら実施例のみに限定されるものではない。なお、「部」は、特に断りのない限り「重量部」を意味し、「％」は、「重量％」を意味する。
【０１０４】
実施例１
温度計、攪拌機、水分離器及び円柱型還流冷却管（コンデンサ）各１個を備えた外部ジャケット付円筒型反応槽にメトキシポリ（ｎ＝１０）エチレングリコール１２３４０部、メタクリル酸６０００部、硫酸３８１部、フェノチアジン４部及びシクロヘキサン５３００部を仕込み、反応温度８５℃でエステル化反応を行った。
反応槽は、外径が３．６ｍ（ジャケットの厚さを含む）、高さが３．８ｍ、内容量が３０ｍ³ であり、反応槽の中心から１．１５ｍの位置に内径０．２ｍの連結管を接続できる構造とした。コンデンサは、外径が０．９ｍ、高さが４ｍの縦型多管型熱交換器（固定管板型）であり、内部に長さが３．５ｍ、外径が２４ｍｍ、厚さが２ｍｍの伝熱管を６２４本もち、塔頂部に禁止剤の溶液を噴霧できる構造とした。
【０１０５】
水分離器は、円筒型槽であり、図１に示されるように、供給管及び邪魔板が備えられ、界面計（Ａ）及び（Ｂ）が設けら、上部及び下部により構成された構造とした。これらの材質はＳＵＳ３０４製とした。上部は高さ２．６ｍ、内径を直径２．２ｍとし、下部は高さ０．３６ｍ、内径を直径０．２ｍとした。また、邪魔板は平板とし、上部の底からの高さが２ｍとなるように円柱の中心から０．５５ｍの位置に設置した。更に、供給管は円管とし、内径を直径２５ｍｍとし、上部の底からの高さが０．４ｍとなる位置を液相部の開放口とし、気相部と液相部との界面となる位置から上に３０〜１００ｍｍの位置に、直径１３ｍｍ（１／２ｉｎｃｈ）の円形の穴４個を邪魔板とは反対方向に縦一列に等間隔に空け、気相部の開放口とした。そして、界面計（Ａ）及び（Ｂ）にはノズルを設け、ゲル化防止剤を注入することができるようにした。
【０１０６】
別途、溶解槽にフェノチアジン０．５部とシクロヘキサン５７８部を混合し、シクロヘキサンの還流開始（内温８２℃）からエステル化反応終了までの間、コンデンサの塔頂部へモーノポンプ（兵神装備社製）を用いてスプレーノズルから噴霧した。また、反応槽の連結部にも、シクロヘキサンをスプレーノズルから噴霧し、界面計（Ａ）及び（Ｂ）には５回に１回フェノチアジン１部を添加してメタクリル酸の重合を防止した。約２４時間でエステル化率が９９％に達したのを確認した。反応生成水の総量で反応率を随時監視した。この反応中、コントロールバルブによって反応生成水の抜き出し量を調整してシクロヘキサンと水との界面を水分離器の下部内に保つように制御した。また、水分離器から反応槽にシクロヘキサンを還流させた。
【０１０７】
得られたエステル化反応液に５０℃以下で４９％水酸化ナトリウム水溶液９６７部及び水３８００部を加えて硫酸とメタクリル酸の一部を中和した。中和後９８℃まで昇温し、シクロヘキサンを水との共沸で留去した。シクロヘキサンの留去中、コンデンサの塔頂部へ上記溶解槽のゲル化防止剤溶液を噴霧した。また連結管のジャケットには上部から蒸気を噴き込み、下部の２箇所の出口（反応槽側とコンデンサ側）からドレイン及び蒸気を抜き出すことによって保温した。そして、シクロヘキサン留去後冷却してエステル化物の水溶液（Ｍ１）を得た。得られた水溶液（Ｍ１）は、別途設けた容器に移送した。以上の操作を３０バッチ繰り返した。３０バッチ操作している間、水分離器内の界面は精度よく一定に保たれ、突沸等は認められなかった。更に、界面計におけるゲル化によるトラブルもなかった。
【０１０８】
比較例１
水分離器として、供給管が側面に開放口を有さず、液相部の開放口だけにした以外は、実施例１と同様にしてエステル化物の水溶液を得た。以上の操作を３０バッチ繰り返したがそのうち２回、反応槽における突沸が起こり、反応液の一部がコンデンサを通じて水分離管まで達した。そのため反応液と水分離管内の脱水溶剤（シクロヘキサン）を廃棄するとともに、脱水反応工程を停止して、連結管、コンデンサ、水分離管を洗浄した。
【０１０９】
比較例２
水分離器の界面の初期設定量を誤り、界面が水分離器の上部になった以外は、実施例１と同様にしてエステル化物の水溶液を得た。脱水反応工程中、反応生成水の量を正確に監視することができず、反応率の目標を達成したかどうか分からなくなった。
【０１１０】
比較例３
水分離器の界面計（Ａ）及び界面計（Ｂ）にフェノチアジン（ゲル化防止剤）を添加しなかった以外は、実施例１と同様にしてエステル化物の水溶液を得た。以上の操作を３０バッチ繰り返したがそのうち１回、溶剤留去工程で界面計（Ａ）及び（Ｂ）でのゲル化によるトラブルが起こった。それぞれの界面計には、ゲルが付着し界面や液面を監視することができなかった。
【０１１１】
実施例２
温度計、攪拌機、水分離器及び冷却管（コンデンサ）を備えた円筒型反応槽にジエチレントリアミン６０００部、アジピン酸７３０９部を仕込み、窒素雰囲気下で攪拌混合した。また水分離器にはコック部にゲル防止化剤としてメトキノン２部を仕込んだ。反応槽は外径が３０ｃｍ（オイルバスで加温）、高さが５０ｃｍ、内容量が０．０３ｍ³ であり、反応槽の中心から１０ｃｍの位置に内径約２ｃｍの連結管を接続できる構造である。コンデンサは市販のガラス製ジムロート（冷却筒長４０ｃｍ、柴田科学器械工業社製）を使用した。生成水分離器及び連結管には、市販の水分定量容器（容量２５ｍｌ、コック付き、柴田科学器械工業社製）を使用した。この水分離器は、コックを閉じた状態では生成水の量がガラスの側面に刻まれた標線から読み取れるため、液面計の機能も兼ね備えている。反応生成水の量は液面の示す標線を読み取ることで監視され、標線の最大値になったところで下部のコックをひねって反応生成水を系外に排出し、新たに反応生成水を読み取ることができる。反応混合物が１５０℃になるまで昇温し縮重合に伴う反応生成水を除きながら２０時間反応させ、縮重合物１１３３２部を得た（生成水は１９７７部であった）。次にハイドロキノンメチルエーテル１７部、メタクリル酸７０１部を仕込み、反応温度１５０℃でアミド化反応を行った。１０時間アミド化反応を行った結果、反応生成水１６０部が生成水分離器で分離され、ポリアミドポリアミンであるアミド化物（Ｍ２）１１８９０部を得た。反応中、生成水に含まれるメタクリル酸がゲル化することはなく、随時コックをひねって水を系外に排出し、生成水量を監視できた。
【０１１２】
比較例４
液面計の機能を兼ね備えた水分離器に、メトキノン（ゲル化防止剤）を添加しなかった以外は、実施例２と同様にしてアミド化物を得た。水分離器の標線の最大値に達したときに反応生成水を系外に排出するべくコックをひねったが、コックの部分でゲルが生じたため生成水を系外に排出できなかった。その時点より、反応生成水の量を監視できなくなった。
【０１１３】
【発明の効果】
本発明の脱水反応生成物の製造方法は、上述の構成よりなるので、製造工程での不具合の発生や、各種の化学製品の性能や品質の低下を充分に抑制することができ、また、得られる脱水反応生成物を高品質のものとすることができる。このような脱水反応生成物は、セメント添加剤（セメント分散剤）や炭酸カルシウム、カーボンブラック、インク等の顔料分散剤、スケール防止剤、石膏・水スラリー用分散剤、石炭・水スラリー（ＣＷＭ）用分散剤、増粘剤等の化学製品の製造原料として好適に用いることができるものである。
【図面の簡単な説明】
【図１】本発明における水分離器の一形態を示した概念図である。
【図２】本発明の脱水反応生成物の製造方法に用いられる装置構成の一形態を示した概略図である。
【符号の説明】
１０１ 反応槽
１０２、１５０ ジャケット
１０３ アルコール用の原料貯蔵タンク
１０５ （メタ）アクリル酸用の原料貯蔵タンク
１０７ 触媒貯蔵タンク
１０９ 重合禁止剤貯蔵タンク
１１１ 中和剤貯蔵タンク
１１３、１１５、１１７、１１９、１２１、１３０、１３７、１３９、１４１、１４５、１４９、１５３、１５７、１６１ 配管
１１６、１６０、１６７、１６９、１７９ ポンプ
１２３ 連結管
１２５、１２８ コンデンサ
１２６ 噴霧ノズル
１２７ 水分離器
１２９ 供給管（配管）
１３１ 邪魔板
１３３ 水分離器内部の室（Ａ）
１３４ 水分離器内部の室（Ｂ）
１３５ 生成水の処理タンク
１３６ 界面計（Ａ）
１３８ 界面計（Ｂ）
１４０ コントロールバルブ
１４２ 循環ポンプ
１４３ 脱水溶剤貯蔵タンク
１４４ 流量計
１４７ ゲル化防止剤貯蔵タンク
１５１ 循環経路
１５５ 真空ポンプ
１５９ 水溶性ゲル化防止剤貯蔵タンク
１６２ 供給管１２９に空けられた穴[0001]
BACKGROUND OF THE INVENTION
The present invention provides a method for producing a dehydration reaction product comprising a dehydration reaction step in which an alcohol and / or amine and (meth) acrylic acid are esterified and / or amidated in the presence of a dehydration solvent, and obtained thereby. The present invention relates to a method for producing a cement additive.
[0002]
[Prior art]
A method for producing a dehydration reaction product comprising a dehydration reaction step is applied to the production of various esters and amides produced by reactions involving dehydration reactions such as esterification and amidation. Such esters and amides are useful as raw materials for producing various polymers, for example, as (meth) acrylic acid ester monomers and (meth) acrylic acid amide monomers. Such polymers include, for example, cement additives (cement dispersants), calcium carbonate, carbon black, pigment dispersants such as ink, scale inhibitors, gypsum / water slurry dispersants, coal / water slurry (CWM). It is suitably used for chemical products such as dispersants and thickeners.
[0003]
By the way, in the dehydration reaction step, the esterification reaction or amidation reaction is a reaction that reaches chemical equilibrium. Therefore, if the by-product water produced is not removed from the reaction system, that is, if the produced water is accumulated in the reaction system, The reaction to produce an amidate does not proceed. Therefore, the generated water is removed by distilling (azeotropically) this and the generated water using a dehydrated solvent. For example, a method of separating and removing generated water from the distillate, refluxing the dehydrated solvent to the reaction system and performing the reaction, and removing the dehydrated solvent by removing it from the reaction vessel containing the esterified product or amidated product after the reaction is completed. It has been.
[0004]
In JP-A-9-328346, in Comparative Examples 1 and 2, a reactor (separable flask) is provided with a thermometer, a stirrer, and a generated water separator so that the generated water can be separated. As methacrylic acid and methoxypolyethylene glycol (average addition mole number of oxyethylene group: 10 mol), sulfuric acid (Comparative Example 1) or paratoluenesulfonic acid (Comparative Example 2) as an acid catalyst, phenothiazine as a polymerization inhibitor, and dehydrating solvent Cyclohexane is charged and heated with stirring, the cyclohexane-water azeotrope is distilled off under normal pressure, and the esterification reaction is carried out by refluxing cyclohexane while removing the produced water with a water separator. A method of synthesizing a target esterified product by distilling off the cyclohexane thus produced is disclosed.
[0005]
However, in such a manufacturing method, after distilling the distillate with a condenser, the dehydrated solvent is refluxed while forming the interface between the dehydrated solvent and the produced water using a water separator to remove the produced water. However, when the distillate condensed and liquefied by the condenser is discharged to the water separator, there are the following problems.
[0006]
That is, (A) If a distillate discharge port is provided in the gas phase part of the water separator, the interface will be shaken by impact when the distillate reaches the liquid level, and the interface between the dehydrated solvent and the produced water will be It cannot be detected accurately. On the other hand, when the discharge port is provided in the liquid phase part of the water separator, not only is the interface swayed, but pressure is applied to the discharge port when distillate is discharged, and from the discharge port at the moment of discharge. The inside of the pipe connected to the reaction tank through the condenser is in a depressurized state, so that a pressure fluctuation occurs in the reaction tank, and the reaction liquid in the reaction tank bumps. (B) The interface cannot be detected accurately. In particular, when the amount of generated water is small or the liquid level is shaken, it is difficult to detect with high accuracy. (C) In the liquid level gauge attached to the water separator, since there is little substantial replacement of the liquid and the liquid pool is generated, a polymerizable such as (meth) acrylic acid distilled with the dehydrated solvent and the generated water is used. The monomer is polymerized to form a gel, so that the liquid level gauge does not function. There was a problem. When such a problem occurs, not only the dehydration reaction product cannot be stably produced, but also the safety is lowered, the repair cost is increased, and the production cost of the dehydration reaction product is increased.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above situation, and includes a dehydration reaction step of esterifying and / or amidating alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, A method for producing a dehydration reaction product using a reaction vessel and a water separator as essential components, wherein (A) the by-product water produced is removed from the reaction system, while preventing bumping of the reaction solution, and (B) dehydration. By improving and stabilizing the detection accuracy of the interface between the solvent and the produced water, and (C) the formation of the gel-like substance is sufficiently suppressed, the occurrence of defects in the production process is sufficiently prevented. It aims at providing the manufacturing method of the dehydration reaction product which can be suppressed.
[0008]
[Means for Solving the Problems]
The present invention is a method for producing a dehydration reaction product comprising a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, The dehydration reaction step is performed using a reaction vessel and a water separator as essential, the water separator is provided with a supply pipe connected to the reaction vessel, and a gas phase part and a liquid phase part are provided therein. The supply pipe is a method for producing a dehydration reaction product having an open port in a gas phase part and a liquid phase part.
[0009]
The present invention is also a method for producing a dehydration reaction product comprising a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, The dehydration reaction step is performed using a reaction tank and a water separator as essential, the water separator is provided with a supply pipe connected to the reaction tank, and a gas phase part and a liquid phase part are provided therein. And a method for producing a dehydration reaction product in which the diameter of the lower part is smaller than the diameter of the upper part, and the interface between the dehydrating solvent and the produced water is maintained at the lower part.
[0010]
The present invention further relates to a method for producing a dehydration reaction product comprising a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, The dehydration reaction step is performed using a reaction tank and a water separator as essential, the water separator is provided with a supply pipe connected to the reaction tank, and a gas phase part and a liquid phase part are provided therein. And a method for producing a dehydrated reaction product in which a detection device for the interface between the dehydrated solvent and the generated water and / or the gas-liquid interface is provided, and an antigelling agent is allowed to act inside the detection device.
[0011]
As a result of diligent research to efficiently produce a high-quality dehydration reaction product, the present inventors have devised the supply pipe provided in the water separator used in the (A) dehydration reaction step, and the reaction solution suddenly boiled. (B) the interface between the dehydrated solvent and the produced water is stabilized and the detection accuracy is improved, and (B) the detection accuracy of the interface between the dehydrated solvent and the produced water is improved by devising the shape of the water separator; It has also been found that if the detection device provided in the water separator is devised, clogging with a gel-like substance in the detection device is sufficiently suppressed. Specifically, (1) the supply pipe provided in the water separator is set so as to have an opening in the gas phase portion and the liquid phase portion in the water separator, and (2) the shape of the water separator The lower diameter is smaller than the upper diameter, and the interface between the dehydrated solvent and the generated water is kept at the lower part, and (3) gelation is prevented inside the detection device provided in the water separator. The inventors have conceived that the above-mentioned problems can be solved brilliantly by acting an agent, and the present invention has been achieved. Further, since the product obtained by the method for producing a dehydration reaction product using such a water separator is of high quality, this product is preferably used as a raw material for producing a polymer for cement additives. It has also been found that it can be used.
The present invention is described in detail below.
[0012]
The method for producing a dehydration reaction product of the present invention comprises a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent. Moreover, in the form normally implemented of the manufacturing method of such a dehydration reaction product, following the dehydration reaction process, the neutralization process mentioned later, a solvent distillation process, etc. are included.
[0013]
First, the apparatus in the present invention used in the dehydration reaction step will be described.
The dehydration reaction step is performed using a reaction tank and a water separator as essential, and the water separator is provided with (1) a supply pipe connected to the reaction tank, and a gas phase section inside. A liquid phase part, and the supply pipe has an opening in the gas phase part and the liquid phase part. (2) a supply pipe connected to the reaction vessel is provided, and the gas phase part is provided inside. And a liquid phase part, and the lower diameter is smaller than the upper diameter, and the interface between the dehydrated solvent and the generated water is maintained at the lower part. (3) Connected to the reaction vessel And a gas phase part and a liquid phase part inside, and a detection device for the interface between the dehydrated solvent and the generated water and / or the gas-liquid interface is provided inside the detection device. It is the form which combined either of the forms which make a gelatinization inhibitor act, or these. A preferable form of such a water separator is a form in which all of the above (1) to (3) are combined.
In the present invention, the water separator is used, for example, the distillate vaporized in a reaction tank and condensed and liquefied by a condenser is separated into a dehydrated solvent and produced water, and the dehydrated solvent is reacted while removing the produced water. The operation of refluxing to the tank will be performed.
[0014]
In addition, a distillate means all the things distilled from a reaction tank by a dehydration reaction process and other processes. That is, the reaction product water distilled off from the reaction vessel, the product water from the raw material charged in the form of an aqueous solution, and a dehydrated solvent used for azeotroping with the product water as needed, was distilled (meta ) Means containing reaction raw materials such as acrylic acid, and examples of the form include gaseous and liquid forms.
[0015]
In the form (1), the supply pipe has open ports in the gas phase portion and the liquid phase portion. In this case, the liquid distillate is supplied from the opening of the liquid phase part of the supply pipe into the water separator, and the gaseous distillate is discharged from the opening of the gas phase part. The fluctuation of the pressure in the liquid phase portion can be suppressed, and thereby the operational effect of the present invention can be exhibited.
[0016]
In the water separator, the supply pipe connected to the reaction tank is a pipe for supplying a distillate from the reaction tank into the water separator. The form in which the reaction vessel and the water separator are connected is usually connected via a condenser, but is particularly limited as long as the distillate from the reaction vessel is supplied into the water separator. It is not something. The supply pipe may be a single pipe or a plurality of pipes, and may be branched or unbranched. Further, when branched, it has a branch pipe. For example, even if it has a branch pipe from the gas phase part to the liquid phase part, it is directed from the liquid phase part to the gas phase part. And may have a branch pipe. Furthermore, the cross-sectional shape is not particularly limited, and for example, a circular shape is preferable. Such a supply pipe is preferably in the form of a single pipe (circular pipe) having a circular cross section and no branch pipe. An open port means the supply port into the water separator of the distillate supplied from a supply pipe, and is a 1 or several hole provided in the front-end | tip and side surface of a supply pipe or a branch pipe. Although there is no restriction | limiting in particular as a shape of such an open port, For example, it is preferable that it is circular.
[0017]
In the form of (1), it is preferable that the opening of the gas phase part of the supply pipe is one or a plurality of holes formed in the side surface of the supply pipe. More preferably, it is preferable to devise so that liquid distillate is not ejected by discharging only gas through the opening of the gas phase portion. The diameter of the opening to the gas phase is preferably 1 to 200 mm, more preferably 5 to 100 mm, and even more preferably 10 to 50 mm. The number of open ports in the gas phase part is preferably 1 to 50, for example, depending on the size. More preferably, it is 1-10. By doing in this way, it becomes possible to fully suppress the fluctuation | variation of the pressure of the liquid phase part in a water separator.
[0018]
In the mode (1), it is preferable that the water separator is further provided with a baffle plate, and the opening of the gas phase part of the supply pipe is in the direction opposite to the baffle plate. By providing the baffle plate, in the liquid phase part in the water separator, the dehydrated solvent is present in the upper phase and the generated water is present in the lower phase (A), and overflow (overflow) from above the baffle plate. ) And the chamber (B) where the dehydrated solvent is present, the generated water can be efficiently removed and the dehydrated solvent can be refluxed. At this time, the opening of the liquid phase part that the supply pipe has is in the chamber (A), and the opening of the gas phase part that the supply pipe has is in the direction opposite to the baffle plate, The distillate to be discharged is prevented from being mixed into the chamber (B), thereby preventing the generated water from being mixed in the dehydrated solvent to be refluxed.
[0019]
In the form (2), the lower diameter of the water separator is smaller than the upper diameter, and the interface between the dehydrated solvent and the produced water is maintained at the lower part. Thereby, the detection accuracy of the interface between the dehydrated solvent and the generated water can be improved. Therefore, it is possible to stably perform the dehydration reaction in the dehydration reaction process by accurately controlling the reflux amount of the dehydrated solvent and the amount of extracted water and maintaining a stable interface between the dehydrated solvent and the generated water. It becomes. In this case, the form in which the diameter of the lower part becomes thinner than the diameter of the upper part includes, for example, a form that gradually or continuously narrows from the upper part to the lower part. It is preferable that the lower diameter is substantially constant and the lower diameter is smaller than the upper diameter. By making the diameter of the lower part substantially constant, the liquid volume can be easily converted from the height of the interface, and there is no error due to complicated calculation. In addition, as a method for controlling the interface between the dehydrated solvent and the produced water to be kept at the lower part, for example, the distillate is detected in the water separator while detecting the interface between the dehydrated solvent and the produced water using an interface meter. The speed can be adjusted by adjusting the speed supplied to the inside and the speed at which the dehydrated solvent and produced water separated in the water separator are removed to the outside of the water separator. At this time, it is preferable to control the position of the interface by adjusting the opening of the control valve.
[0020]
In the form (3), the water separator is provided with a detection device for the interface between the dehydrated solvent and the produced water, and the gelling inhibitor is allowed to act inside the detection device. Further, when the water separator is further provided with a baffle plate and a detection device for the interface between the gas phase portion and the liquid phase portion (dehydrated solvent) is provided in the chamber (B), the inside of the detection device is also gelled. It is preferable to make an inhibitor act. By causing an anti-gelling agent to act inside the detection device, it is sufficiently suppressed that the detection device is clogged with a gel-like material, causing problems in the manufacturing process and the performance and quality of various chemical products. The decrease can be sufficiently suppressed. The detection device is not particularly limited as long as it has a means capable of detecting the interface. For example, an apparatus having a detecting means using a specific gravity difference or electric resistance is mentioned. As will be described later in FIG. 1, a distillate liquefied from a water separator is introduced into a pipe to detect an interface, so-called It is preferable to use an interface meter.
[0021]
Examples of the anti-gelling agent include polymerization inhibitors, and specific examples include phenothiazine, tri-p-nitrophenylmethyl, di-p-fluorophenylamine, diphenylpicrylhydrazyl, N- ( 3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide, benzoquinone, hydroquinone, methoquinone, butylcatechol, nitrosobenzene, picric acid, dithiobenzoyl disulfide, cuperone, copper (II) chloride and the like. These may be used alone or in combination of two or more. Among these, it is preferable to use phenothiazine, hydroquinone, and methoquinone.
[0022]
The amount of the above-mentioned gelation inhibitor is appropriately set to an amount suitable for the amount of distillate depending on, for example, the dehydration reaction conditions, especially the amount of heat acting on the reaction system and the amount of dehydrated solvent charged into the reaction system. For example, it is preferable to set it as 0.1-5000 weight ppm with respect to the total weight of the charging amount of alcohol and amine which are reaction raw materials, and (meth) acrylic acid. If the amount is less than 0.1 ppm by weight, the effect of the gelation inhibitor may not be sufficiently exhibited. If the amount exceeds 5000 ppm by weight, the expression of the effect corresponding to the amount to be acted on cannot be expected, which is uneconomical. There is a risk of becoming. More preferably, it is 5 to 500 ppm by weight.
[0023]
The method for causing the anti-gelling agent to act on the detection device is not particularly limited as long as it is a method that can effectively exhibit the action and effect of the anti-gelling agent. For example, a nozzle is provided at a site in the detecting device to be acted on. An antigelling agent can be injected from the nozzle. The site to be acted on is preferably near the interface between the dehydrated solvent and the generated water or near the interface between the gas phase part and the liquid phase part (dehydrated solvent). In addition, the time of action is when the dehydrating solvent or water is present in the water separator. In particular, it is preferable to act while a polymerizable monomer such as (meth) acrylic acid is present in the dehydrating solvent or water phase of the water separator. In particular, it is preferable to act when the monomer is supplied to the water separator, that is, during the dehydration of the dehydration reaction product or during the dehydration solvent distillation. Furthermore, examples of the form of the antigelling agent to be acted include a form liquefied (dissolved) with a solvent, a solidified form such as a powder, a vaporized form including a sublimated state, etc. Among these, a solvent or the like It is preferable to use a form liquefied by the above, particularly a form liquefied by the same kind of solvent as the dehydrated solvent.
[0024]
The material of the water separator and the supply pipe and baffle plate provided in the present invention is not particularly limited, and known materials can be used. For example, SUS304, SUS316, preferably SUS304, SUS316, SUS316L, More preferably, SUS316, SUS316L, etc. are mentioned. Further, the water separator may be subjected to glass lining processing, Teflon processing, or the like so as to be inert to the corrosiveness of the reaction raw materials and products.
[0025]
The water separator in the present invention will be described with reference to FIG.
FIG. 1 is a conceptual diagram illustrating a water separator in the present invention. In FIG. 1, a supply pipe is provided, a gas phase part and a liquid phase part are provided therein, a baffle plate is further provided, and an interface meter (A ) And an interface meter (B) as a device for detecting the gas-liquid interface between the gas phase part and the liquid phase part (dehydrated solvent) in the water separator chamber (chamber (B)) opposite to the supply pipe from the baffle plate One form of the water separator which is provided and has a product water outlet and a dehydrated solvent outlet at the bottom is shown. In this form, the opening of the gas phase section of the supply pipe is a plurality of holes formed in the side surface of the supply pipe, and is in the direction opposite to the baffle plate, and the diameter of the lower part of the water separator is A control valve (not shown) is provided in the pipe that is narrower than the upper diameter and connected to the product water outlet and the dehydrated solvent outlet, and is controlled so that the interface between the dehydrated solvent and the produced water is maintained at the lower part. The nozzle is controlled by a valve, and further provided with a nozzle (anti-gelling agent injection port) for allowing the anti-gelling agent to act inside the interfacial meter (A) and interfacial meter (B).
[0026]
In FIG. 1 above, the supply pipe is connected to a condenser (not shown), and the gaseous distillate generated in the reaction tank is condensed and liquefied by the condenser, passes through the supply pipe, and is provided on the supply pipe side from the baffle plate. In the chamber [A], the generated water accumulates in the lower phase and the dehydrated solvent accumulates in the upper phase. Further, the dehydrated solvent collected in the upper phase of the chamber (A) flows over the baffle plate and enters the chamber (B) and accumulates. The generated water accumulated in the chamber (A) is removed from the generated water outlet by being adjusted by the control valve while detecting the interface with the interface meter (A) so that the interface between the dehydrated solvent and the generated water is at a fixed position. The dehydrated solvent accumulated in the chamber (B) is adjusted by the control valve while detecting the interface with the interface meter (B), extracted from the dehydrated solvent outlet, and returned to the reaction vessel. At this time, an anti-gelling agent acts inside the interfacial meter (A) and the interfacial meter (B) to prevent clogging due to the formation of a gel-like material. In FIG. 1, the dehydrated solvent and the generated water are indicated by oblique lines.
[0027]
In FIG. 1 above, as the positions of the gas phase part and the liquid phase part opening port of the supply pipe, for example, distillate from the gas phase part or liquid phase part opening port enters the chamber (B). It is preferable to set in a place where it is difficult to adhere to the inner wall of the water separator. Further, it is preferable that the baffle plate is sufficiently high. If the baffle plate is too low, the distillate may overflow over the baffle plate before entering the chamber (B) before the distillate is separated into the dehydrated solvent and generated water in the chamber (A). Moreover, it is because the capacity of the water separator cannot be fully utilized effectively.
[0028]
In the form of FIG. 1, it is preferable that the lower diameter of the water separator is set to be sufficiently thinner than the upper diameter. For example, it is preferable that the ratio of the diameters of the lower and upper diameters is set to 1/20 to 1/2. If the diameter of the lower part is less than 1/20, if the height is not increased, the water storage capacity is reduced and the water separator may become too large. If the diameter of the lower part is less than 1/2, There is a possibility that the detection accuracy of the interface with the generated water is not sufficiently improved. More preferably, it is 1/10 to 1/3.
[0029]
In the form of FIG. 1 described above, it is also preferable that the ratio between the lower height and the upper height in the water separator is set to 1/30 to 1/1. If the height of the lower part is too lower than 1/30, the generated water accumulated in the lower part may flow into the upper part and the detection accuracy of the interface between the dehydrated solvent and the generated water may not be sufficiently improved. However, if the height of the lower part is too high, the device may become too large. More preferably, it is 1/10 to 1/2.
[0030]
As described above, the water separator used in the method for producing a dehydration reaction product of the present invention esterifies and / or amidates alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent. In a method for producing a dehydration reaction product comprising a dehydration reaction step and using a reaction vessel and a water separator as essential, byproduct water produced as a by-product is removed from the reaction system, and bumping in the reaction vessel is prevented. In addition, by improving and stabilizing the detection accuracy of the interface between the dehydrated solvent and the produced water, and by sufficiently suppressing the formation of gel-like substances, the occurrence of problems in the manufacturing process and various It has the effect of being able to sufficiently suppress the deterioration of the performance and quality of chemical products. Such a water separator is one of the preferred embodiments of the present invention.
[0031]
In the present invention, the dehydration reaction product is also preferably used as a raw material for producing a polymer for cement additive. That is, it is preferable to use a polymer obtained from a dehydration reaction product produced using the production method of the present invention as a raw material for producing cement additives. Thereby, in manufacture of a cement additive, the fall of the performance and quality is suppressed, and it becomes possible to manufacture stably.
[0032]
Next, as a method for producing a dehydration reaction product, a method comprising a neutralization step, a solvent distillation step, etc. as necessary following the dehydration reaction step will be described.
In the dehydration reaction step, for example, using a dehydration reaction apparatus that essentially includes a reaction tank, a condenser, and a connecting pipe for connecting the reaction tank and the condenser, and a water separator connected to the condenser and a supply pipe. Done. Using such a dehydration reaction apparatus, a distillation operation is performed using a condenser and a water separator while performing a dehydration reaction in a reaction vessel.
[0033]
In the dehydration reaction step, when the dehydration reaction is in chemical equilibrium, the reaction proceeds when the reaction water generated by the reaction is removed from the reaction tank. In such a process, (1) in order to make it easy to remove the reaction product water generated in the reaction vessel, if necessary, a dehydrating solvent is mixed with the reaction solution, and the dehydrated solvent and the generated water are azeotropically vaporized. (2) an operation in which the distillate passes through a connecting pipe connecting the reaction vessel and the condenser and enters the condenser, and the distillate is condensed and liquefied in the condenser; (3 ) Operation to separate the condensed and liquefied distillate into dehydrated solvent and produced water in a water separator connected to the condenser, (4) Operation to recirculate the separated dehydrated solvent into the reaction tank, etc. Will be done.
[0034]
The reaction vessel is used in the same meaning as the reactor, reaction vessel, reaction kettle and the like, and is not particularly limited as long as it is a vessel capable of performing a dehydration reaction. The shape of the reaction vessel is not particularly limited. Although there are a polygonal type and a cylindrical type, a cylindrical type is preferable from the viewpoints of stirring efficiency, handleability, and versatility. The presence or absence of a baffle plate does not matter. The reaction tank may be heated by bringing a heating medium such as steam into contact with the outer jacket, or it is equipped with a heat transfer device such as a coil inside the reaction tank for heating. Also good. The material inside such a reaction vessel is not particularly limited, and a known material can be used. For example, SUS304, SUS316, SUS316L, more preferably SUS316, made of SUS, preferably from the viewpoint of corrosion resistance. SUS316L etc. are mentioned. Moreover, it is good also as what is inactive with respect to a reaction raw material and a product by giving the glass lining process etc. inside the reaction tank. Such a reaction tank is usually equipped with a stirrer to perform a dehydration reaction uniformly and efficiently. The stirrer is not particularly limited. The stirrer is usually composed of an electric motor, a shaft, and a stirrer, but the stirrer may have any shape. As a stirrer, desk turbine, fan turbine, curved fan turbine, arrow blade turbine, multistage fan turbine blade, fowler blade, bull margin type, angled blade, propeller type, multistage blade, anchor type, gate type, double ribbon A blade, a screw blade, a Max blend blade, etc. can be mentioned. Among them, a multistage fan turbine blade and a Faudler blade are preferable from the viewpoint of versatility.
[0035]
The condenser is a device that condensates and distills the distillate generated from the reaction tank, and the condensation is performed by exchanging heat between the extra-fluid fluid that is the cooling liquid and the distillate.
[0036]
As the material of the capacitor, known materials such as SUS304, SUS316, SUS316L, etc., carbon steel (CS), and the like can be used. In order to further reduce the generation of gel-like substances, a capacitor whose inner surface is mirror-finished or glass-lined can be used. However, from the viewpoint of cost for processing and maintenance, SUS304, SUS316, SUS316L, preferably SUS316, SUS316L. It is preferable to use a SUS capacitor such as
[0037]
The heat transfer area of the capacitor varies depending on the volume of the reaction tank, etc.^Three Then, 50-500m² It is preferable that More preferably, 100-200m² It is. Examples of the cooling medium used in such a condenser include water and oil.
[0038]
The volume of the water separator varies depending on the volume of the reaction tank, the amount of distillate, etc.^Three Then, 1-20m^Three It is preferable that More preferably, 3-10m^Three It is.
[0039]
The dehydration reaction step is a step of esterifying and / or amidating alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, thereby producing an ester and / or amide. . The compounds used as reaction raw materials in such steps may be used alone or in combination of two or more. In the present specification, the above esters and amides are also referred to as esterified products and amidated products, respectively.
[0040]
The alcohol used in the esterification reaction is not particularly limited as long as it is a compound having a hydroxyl group, and examples thereof include alcohols, phenols, diols, trivalent or higher alcohols, and polyols. For example, alcohols include methanol, ethanol, n-propanol, n-butanol, 2-ethylbutanol, n-octanol, 1-dodecanol, 1-octadecanol, 2-ethylhexanol, cyclohexanol, allyl alcohol, 3 Primary alcohols such as methyl-3-buten-1-ol; iso-propyl alcohol, 2-butanol, 2-pentanol, 3-pentanol, 2-heptanol, 3-heptanol, methylamyl alcohol, 2-octanol Secondary alcohols such as nonyl alcohol and alcohols having 12 to 14 carbon atoms such as “Softanol (trade name)” manufactured by Nippon Shokubai Co., Ltd .; tertiary alcohols such as tert-butanol and tert-pentanol; For example, phenol, And diols include monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, monopropylene glycol, dipropylene glycol, polyethylene, and the like. Polypropylene glycol, diethanolamine, N-butyldiethanolamine and the like, and trivalent or higher alcohols and polyols include glycerin, trimethylolpropane, 1,3,5-pentanetriol, pentaerythritol, glucose, fructose, sorbitol, Examples thereof include gluconic acid, tartaric acid, polyvinyl alcohol and the like.
[0041]
The alcohol preferably contains a compound represented by the following general formula (1), and such a compound is preferably contained as a main component in the alcohol. In this case, the alcohol may or may not contain other components.
[0042]
R¹ (R² O) nH (1)
In formula (1), R¹ Represents a hydrocarbon group having 1 to 30 carbon atoms. R² O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms, preferably 2 to 8 carbon atoms. n is R² The average added mole number of the oxyalkylene group represented by O is represented by 0 to 300, preferably 2 to 300. The average added mole number means an average value of the number of moles of the repeating unit in 1 mole of the compound.
[0043]
R above¹ The number of carbons exceeds 30 or the above R² If the carbon number of O exceeds 18, the water solubility of the polymer obtained by using the esterified product as a production raw material is lowered, and there is a possibility that the use performance when used as a cement additive or the like, that is, the cement dispersion performance is lowered. . On the other hand, when n exceeds 300, the reactivity between the compound represented by the general formula (1) and (meth) acrylic acid may be lowered.
[0044]
R above¹ Or R² The range of the suitable carbon number of O will be set by the intended use of the esterified product. For example, when an esterified product is used as a raw material for producing a cement additive polymer, R¹ As, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, 2-ethylhexyl group, decyl group, dodecyl Group, undecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, heneicosyl group, docosyl group and other alkyl groups; aryl group such as phenyl group; benzyl group, nonyl An alkylphenyl group such as a phenyl group; a cycloalkyl group such as a cyclohexyl group; an alkenyl group; an alkynyl group. Among these, it is preferable to set it as a C1-C18 linear or branched alkyl group and aryl group. More preferably, they are a methyl group, an ethyl group, a propyl group, a butyl group, and a phenyl group.
[0045]
R above² Examples of O include an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxystyrene group. Among these, an oxyethylene group, an oxypropylene group, and an oxybutylene group are preferable. R² O is a repeating unit constituting the compound represented by the general formula (1), and each repeating unit may be the same or different. Among these, in the case of having two or more different repeating units, each repeating unit may be added in a block shape or may be added in a random shape, and is not particularly limited.
[0046]
The range of n is also set depending on the intended use of the esterified product. For example, when the esterified product is used as a raw material for producing a polymer for a cement additive, it is preferably 2 to 300. More preferably, it is 5-200, More preferably, it is 8-150. Moreover, when using as a thickener etc., it is preferable to set it as 10-250. More preferably, it is 50-200.
[0047]
When n is 0, from the viewpoint of solubility in water and boiling point, R¹ Is preferably a hydrocarbon group having 4 or more carbon atoms. That is, when n is 0, alcohol such as methanol or ethanol has a low boiling point, and therefore, it evaporates with the produced water and dissolves in the produced water, whereby a part of the alcohol raw material is distilled out of the reaction system, This is because the yield of the target esterified product is lowered, and this is prevented.
[0048]
The amine used in the amidation reaction is not particularly limited. For example, ammonia; aliphatic primary amines such as methylamine, ethylamine, propylamine, butylamine, dodecylamine, cetylamine; dimethylamine, diethylamine, dipropyl Aliphatic secondary amines such as amine and diamylamine; aliphatic tertiary amines such as trimethylamine, triethylamine, tripropylamine and tributylamine; aliphatic unsaturated amines such as allylamine and diallylamine; cyclopropylamine, cyclobutylamine, Alicyclic amines such as cyclohexylamine; aromatic monoamines such as aniline, monomethylaniline, dimethylaniline and diphenylaniline; aromatic diamines such as o-phenylenediamine and m-phenylenediamine; Aminonaphthalines such as naphthylamine and β-naphthylamine; polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine; monoethanolamine, Oxyethylene amines such as diethanolamine, polyethylene glycol (mono) amine, polyethylene glycol (di) amine; ureas such as urea and thiourea; polyethyleneimine, ethylene oxide adducts to polyethyleneimine, propylene oxide additions to polyethyleneimine And high polymers such as products.
[0049]
In the esterification reaction or amidation reaction, an unsaturated monomer having another carboxyl group can be used together with (meth) acrylic acid. The unsaturated monomer having a carboxyl group is a monomer having at least a carboxyl group and an unsaturated bond. Specifically, unsaturated monocarboxylic acids such as crotonic acid, tiglic acid, citronellic acid, undecylenic acid, elaidic acid, erucic acid, sorbic acid, linoleic acid; maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid And the like, and the like. These may be used alone or in combination of two or more.
[0050]
In the esterification reaction or amidation reaction, a catalyst may be added to the reaction system as necessary, and the reaction is preferably performed in the presence of the catalyst. In particular, an acid catalyst is suitable for the esterification reaction, and the reaction can proceed rapidly. Such an acid catalyst may be used in the form of a hydrate and / or an aqueous solution. For example, sulfuric acid, methanesulfonic acid, paratoluenesulfonic acid, paratoluenesulfonic acid hydrate, xylenesulfonic acid, xylenesulfone Acid hydrate, naphthalene sulfonic acid, naphthalene sulfonic acid hydrate, trifluoromethane sulfonic acid, “Nafion (trade name, manufactured by DuPont)” resin, “Amberlyst 15 (trade name)” resin, phosphotungstic acid, phosphotungsten An acid hydrate, hydrochloric acid, etc. are mentioned. These may be used alone or in combination of two or more.
[0051]
Among the above acid catalysts, those having a high boiling point at normal pressure (1013 hPa) in terms of the azeotropic temperature and reaction temperature of the dehydrating solvent and water described later, specifically, the boiling point at normal pressure is 150 ° C. or higher. Some are preferred. More preferably, it is 200 ° C. or higher. Examples of such an acid catalyst include sulfuric acid (boiling point at normal pressure: 317 ° C.), paratoluenesulfonic acid (boiling point: 185 to 187 ° C./13.3 Pa (0.1 mmHg)), paratoluenesulfonic acid hydrate. And methanesulfonic acid (boiling point: 167 ° C./1333.2 Pa (10 mmHg)). Among these, it is preferable to use paratoluenesulfonic acid and paratoluenesulfonic acid hydrate.
[0052]
The amount of the acid catalyst used is not particularly limited as long as a desired catalytic action can be effectively expressed. For example, it is preferably 0.4 meq / g or less. If it exceeds 0.4 meq / g, the amount of diester formed in the reaction system during the esterification reaction will increase, and the cement dispersibility of the polymer for cement additives synthesized using these may decrease. There is. More preferably, it is 0.36-0.01 meq / g, More preferably, it is 0.32-0.05 meq / g. In addition, the usage-amount (milli equivalent / g) of an acid catalyst is H of the acid catalyst used for reaction.⁺ Is represented by a value obtained by dividing the number of equivalents (milliequivalent) by the total charged amount (g) of the reaction raw material, and specifically means a value calculated by the following formula.
[0053]
[Expression 1]

[0054]
The amount of the acid catalyst used is also the usefulness of esterified products and amidated products used as raw materials for producing polymers applied to various chemical products, and the basic performance required for such applications. From the viewpoint of preventing or suppressing the generation of gel-like substances that adversely affect performance, etc., the ratio of the weight of the acid in the acid catalyst to the total weight of the reaction raw material is X (wt%), and hydration in the acid catalyst 0 <Y <1.81X-1.62, where Y (% by weight) is the weight ratio of water present as a product and / or aqueous solution.
It is preferable that the following relational expression is satisfied.
[0055]
The above relational expression will be described with a specific example. For example, taking paratoluenesulfonic acid monohydrate as an example, the ratio of the weight of paratoluenesulfonic acid to the total weight of the reaction raw materials is X (wt%). Yes, the ratio of the weight of water present as a monohydrate to the total weight of the reaction raw material is Y (% by weight), and never as an acid component other than the acid catalyst, for example, (meth) acrylic of the raw material Acids and moisture, that is, reaction product water generated by the esterification reaction, cannot be the above X and Y objects.
[0056]
In the case where the amount of the acid catalyst used does not satisfy the above relational expression, for example, when Y is 0, there is no moisture present as a hydrate and / or an aqueous solution in the acid catalyst. Occasionally, the amount of gel formed in the reaction system increases, and there is a risk that, for example, cement dispersibility may be reduced as the performance of the polymer for cement additive synthesized using them. If Y ≧ 1.81X−1.62, the amount of gel formed in the reaction system during the esterification reaction increases, and the same as above.
The acid catalyst may be added to the reaction system all at once, continuously or sequentially, but from the viewpoint of workability, it is preferable to charge the reaction tank together with the reaction raw materials.
[0057]
The esterification reaction or amidation reaction is preferably performed in the presence of a polymerization inhibitor. Thereby, polymerization of the unsaturated carboxylic acid in the reaction raw material and the esterified product and / or amidated product thereof can be prevented. As such a polymerization inhibitor, a known polymerization inhibitor can be used, and is not particularly limited. For example, phenothiazine, tri-p-nitrophenylmethyl, di-p-fluorophenylamine, diphenylpicrylhydrazyl, N -(3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide, benzoquinone, hydroquinone, methoquinone, butylcatechol, nitrosobenzene, picric acid, dithiobenzoyl disulfide, cuperone, copper (II) chloride and the like. These may be used alone or in combination of two or more. Among these, phenothiazine, hydroquinone, and methoquinone are preferably used from the viewpoint of solubility. These are extremely useful in that they can exhibit the polymerization inhibiting ability very effectively both in the dehydration reaction step and in the solvent distillation step.
[0058]
As the usage-amount of the said polymerization inhibitor, when the total preparation amount of the alcohol, amine, and acid which are reaction raw materials shall be 100 weight%, it is preferable to set it as 0.001-1 weight%. If it is less than 0.001% by weight, the ability to inhibit polymerization is not sufficiently exhibited, and it is difficult to effectively prevent polymerization of reaction raw materials and products, and if it exceeds 1% by weight, polymerization remaining in the esterified product is prohibited. Since the amount of the agent increases, the quality and performance may be deteriorated, and an effect commensurate with the excessive addition may not be obtained, which may be disadvantageous from an economical viewpoint. More preferably, it is 0.001 to 0.1 weight%.
[0059]
In the above esterification or amidation reaction, by performing a dehydration reaction in the presence of a dehydrating solvent, the generated water and the dehydrated solvent are azeotroped outside the reaction system, and the product water is separated and removed by condensing into liquid. This can be done by refluxing. Thereby, the reaction product water produced | generated by esterification reaction or amidation reaction can be azeotroped efficiently. Such a dehydrating solvent is not particularly limited as long as it is an azeotropic solvent with water, and examples thereof include benzene, toluene, xylene, cyclohexane, dioxane, pentane, hexane, heptane, chlorobenzene, and isopropyl ether. These may be used alone or in combination of two or more. Among these, those having an azeotropic temperature with water of 150 ° C. or lower are preferable, and those having an azeotropic temperature of 60 to 90 ° C. are more preferable. Specific examples of such a dehydrating solvent include cyclohexane, toluene, dioxane, benzene, isopropyl ether, hexane, heptane, and the like. When the azeotropic temperature with water exceeds 150 ° C., handling properties including temperature control in the reaction system during the reaction and control such as a condensate liquefaction treatment of the distillate may be deteriorated.
[0060]
In the dehydration reaction operation using the dehydrating solvent, the amount of the dehydrating solvent used is preferably 0 to 100% by weight when the total amount of alcohol, amine and acid as reaction raw materials is 100% by weight. If it exceeds 100% by weight, an effect commensurate with the excessive addition cannot be obtained, and a large amount of heat is required to keep the reaction temperature constant, which may be disadvantageous from an economical viewpoint. More preferably, it is 2 to 50% by weight.
[0061]
In the dehydration reaction step, the esterification reaction and the amidation reaction can be carried out by either a batch or continuous reaction operation method, but it is preferably carried out in a batch manner. Moreover, it does not specifically limit as reaction conditions, What is necessary is just the conditions which reaction advances smoothly, For example, as reaction temperature, it is preferable to set it as 30-180 degreeC. More preferably, it is 60-130 degreeC, More preferably, it is 90-125 degreeC, Most preferably, it is 100-120 degreeC. When the temperature is lower than 30 ° C, the reflux of the dehydrating solvent is slowed down, and it takes time for dehydration, and the reaction may not easily proceed. In polymers obtained by chemicals and amidated products, the dispersion performance and viscosity increase characteristics in various applications such as cement dispersion performance, polymerization of reaction raw materials, increase in the amount of reaction raw materials mixed in the distillate, There is a risk of degradation of performance and quality of the amidated product.
[0062]
In the above reaction conditions, the reaction time is preferably set until the reaction rate reaches 70% or more as described later. More preferably, it reaches 80% or more, and even more preferably, it reaches 98% or more. Usually, it is 1 to 100 hours, preferably 3 to 60 hours. In addition, the reaction pressure may be performed under normal pressure or reduced pressure, but it is preferably performed under normal pressure from the viewpoint of equipment.
[0063]
The reaction rate of the esterification reaction or amidation reaction is preferably set to 70% or more. If it is less than 70%, the yield of the ester or amide produced is insufficient, and there is a risk that the application performance of the polymer for cement additive obtained using this as a polymerization raw material, that is, the cement dispersibility, etc. may be lowered. is there. More preferably, it is 70-99%, More preferably, it is 80-98%. The above reaction rate is the ratio of the amount of alcohol or amine that is a reaction raw material when charged and the amount at the end of the reaction. For example, it is measured as the area of each peak by liquid chromatography (LC) under the following measurement conditions. By doing so, it is a value (%) calculated by the following formula.
[0064]
[Expression 2]

[0065]
Reaction rate measurement conditions
Analysis device: Millennium Chromatography Manager (trade name) manufactured by Waters
Detector: 410 RI detector manufactured by Waters (trade name)
Column used: Inertsil ODS-2 (inner diameter 4.6 mm, length 250 mm) (product name), manufactured by GL Science
Column temperature: 40 ° C
Eluent: 8946 g of water, 6000 g of acetonitrile and 54 g of acetic acid are mixed, and a solution adjusted to pH 4.0 with 30% aqueous sodium hydroxide solution is used.
Flow rate: 0.6 ml / min
[0066]
In the method for producing a dehydration reaction product of the present invention, when an acid catalyst is used in the dehydration reaction step, it is preferable to perform a neutralization step of neutralizing the acid catalyst or (meth) acrylic acid. As a result, the catalyst loses its activity, the hydrolysis of the dehydration reaction product obtained by the esterification reaction or amidation reaction is suppressed, and the generation of impurities not involved in the polymerization is suppressed. It is possible to suppress the decrease.
[0067]
As the method of the neutralization step, for example, a method of neutralizing the acid catalyst with a neutralizing agent after completion of the esterification reaction or amidation reaction is preferable.
The neutralizing agent is not particularly limited as long as it can neutralize the acid catalyst. For example, alkali metal such as sodium hydroxide, potassium hydroxide, calcium hydroxide and lithium hydroxide, hydroxide of alkaline earth metal; alkali metal such as sodium carbonate, calcium carbonate and lithium carbonate, carbonate of alkaline earth metal Salts: Amines such as ammonia, monoethanolamine, diethanolamine, triethanolamine and the like can be mentioned, and one or more of these are used. Moreover, it does not specifically limit as a form of a neutralizing agent, For example, it is preferable to set it as the form of alkaline aqueous solution.
[0068]
In the neutralization step, the acid catalyst and (meth) acrylic acid are neutralized, but it is preferable to set so that all of the acid catalyst and part of (meth) acrylic acid are neutralized. . In this case, the (meth) acrylic acid to be neutralized is 20% by weight or less, preferably 0.01 to 5 when the remaining (meth) acrylic acid after the esterification reaction or amidation reaction is 100% by weight. It is preferable that it is weight%. It should be noted that the acid catalyst and (meth) acrylic acid are neutralized from the acid catalyst because the acid catalyst has higher acid strength.
[0069]
In the neutralization method in the neutralization step, when an esterification reaction or an amidation reaction is performed in a dehydrating solvent, it is preferable to add a large amount of water together with an alkali to the reaction system. In other words, in the absence of a large amount of water, the alkali is hardly soluble in the dehydrating solvent, so it floats in the system in a concentrated state, and such a high concentration of alkali floats for a long time until it is consumed for neutralization. It does not disappear and causes hydrolysis of esterified products and amidated products. In this case, the amount of water added depends on the form of alkali used. For example, when 40 to 60% by weight of an alkaline aqueous solution is added as a neutralizing agent, the alkaline aqueous solution 1 is added separately from the alkaline aqueous solution. Usually, it is preferably 5 to 1000 parts by weight with respect to parts by weight. More preferably, it is 10 to 100 parts by weight. If the amount is less than 5 parts by weight, the alkali may become non-uniform in the reaction system. If the amount exceeds 1000 parts by weight, the production cost increases, such as a separate neutralization tank is required to ensure productivity. There is a risk.
[0070]
For example, the neutralization temperature in the neutralization step is preferably 90 ° C. or lower. More preferably, it is 0-80 degreeC. More preferably, it is 25-65 degreeC. When it exceeds 90 ° C., the added neutralizing agent acts as a catalyst for hydrolysis, and there is a possibility that a large amount of hydrolysis products may be generated. When the temperature is 80 ° C. or lower, the formation of hydrolysis products is more sufficiently suppressed. However, when the temperature is lower than 0 ° C., the reaction solution becomes viscous, which makes stirring difficult. In order to distill off water after the reaction, it takes a long time to lower the temperature to a predetermined temperature, or it is necessary to install cooling means (equipment) to lower the temperature to a temperature lower than room temperature. Cost may increase.
[0071]
Except for the case where the dehydrated solvent is used in the polymerization step or the like, the dehydrated solvent is preferably distilled off. In the solvent distillation step, the method for distilling off the dehydrated solvent is not particularly limited. For example, the solvent may be distilled off by distilling only the dehydrated solvent, or may be distilled off by adding other appropriate additives. However, it is preferable to azeotropically distill off with a dehydrating solvent using water. In this case, since the neutralization step is performed, there is substantially no acid catalyst or alkali in the reaction system. Therefore, the hydrolysis reaction does not occur even if the temperature is increased by adding water. By such a method, the dehydrated solvent can be removed at a lower temperature.
[0072]
The conditions for the distillation method are not particularly limited as long as the dehydrating solvent in the reaction system is suitably distilled (evaporated). For example, the liquid temperature in the reaction vessel during solvent distillation (under normal pressure) ), When water is used, it is usually preferably 80 to 120 ° C. More preferably, it is 90-110 degreeC. Moreover, when not using water, it is preferable to set it as 80-160 degreeC normally. More preferably, it is 90-150 degreeC. In any of the above cases, if the temperature is lower than the above temperature, there is a possibility that the temperature (calorie) sufficient to evaporate the dehydrated solvent may not be obtained. If the temperature is higher than the above temperature, polymerization may be caused. A large amount of heat may be consumed for evaporation of a large amount of low-boiling-point raw materials. The pressure in the reaction vessel may be under normal pressure or under reduced pressure, but it is preferably from the equipment side under normal pressure.
As the apparatus system used in the solvent distillation process, it is preferable to use the apparatus system used in the dehydration reaction process as it is.
[0073]
The dehydration reaction product obtained by the method for producing a dehydration reaction product of the present invention includes various polymers, that is, pigment additives such as cement additives, calcium carbonate, carbon black, ink, scale inhibitors, gypsum / water slurry. It is suitably applied as a production raw material for producing a polymer used in chemical products such as a dispersant for coal, a dispersant for coal / water slurry (CWM), and a thickener.
[0074]
In the following, a method for producing a polymer for cement dispersant using a dehydration reaction product obtained by the method for producing a dehydration reaction product as a production raw material, and a method for producing a cement additive containing the polymer for cement dispersant A method of using the cement additive will be described.
[0075]
Examples of the polymer for cement dispersant include a polycarboxylic acid polymer obtained by polymerizing a monomer having the obtained dehydration reaction product and an unsaturated carboxylic acid monomer as essential components. There is no restriction | limiting in particular as a polymerization method of such a polycarboxylic acid type polymer, For example, well-known polymerization methods, such as solution polymerization using a polymerization initiator, and block polymerization, are employable.
[0076]
Examples of the unsaturated carboxylic acid-based monomer include unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, tiglic acid, citronellic acid, undecylenic acid, elaidic acid, erucic acid, sorbic acid, and linoleic acid; Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid; monoesters of these dicarboxylic acids and alcohols, etc., and monovalent metal salts, divalent metal salts thereof, Examples thereof include ammonium salts and organic amine salts.
[0077]
The polycarboxylic acid polymer may be copolymerized with a monomer other than the unsaturated carboxylic acid monomer, if necessary. Examples of such monomers include unsaturated amides such as (meth) acrylamide and (meth) acrylalkylamide; vinyl esters such as vinyl acetate and vinyl propionate; vinyl sulfonic acid, (meth) allyl sulfonic acid, Unsaturated sulfonic acids such as sulfoethyl (meth) acrylate, 2-methylpropanesulfonic acid (meth) acrylamide, and styrene sulfonic acid, and their monovalent metal salts, divalent metal salts, aluminum salts, organic amine salts; styrene, α- Aromatic vinyls such as methylstyrene; esters of (meth) acrylic acid with an alcohol having a phenyl group such as an aliphatic alcohol or benzyl alcohol having 1 to 18, preferably 1 to 15 carbon atoms; polyalkylene glycol mono ( (Meth) acrylate; polyalkylene glycol mono (meth) allyl Ether and the like.
[0078]
The polycarboxylic acid polymer is preferably a polymer having a specific weight average molecular weight. For example, the weight average molecular weight in terms of polyethylene glycol by gel permeation chromatography (hereinafter referred to as “GPC”) under the following measurement conditions is preferably, for example, 500 to 500,000. If it is less than 500, the water reducing performance of the cement additive may be lowered, and if it exceeds 500,000, the water reducing performance and slump loss preventing ability of the cement additive may be lowered. More preferably, it is 5000-300000, Most preferably, it is the range of 8000-100,000.
[0079]
The GPC includes an eluent storage tank, an eluent liquid feeder, an autosampler, a column oven, a column, a detector, a data processor, and the like. For example, the molecular weight can be measured by setting measurement conditions by combining the following commercially available apparatuses.
[0080]
Molecular weight measurement conditions
Model: LC module 1plus (trade name, manufactured by WATERS)
Detector: differential refractometer (RI) 410 differential refractometer (trade name, manufactured by WATERS)
Eluent: 0.05M sodium acetate, acetonitrile / ion-exchanged water = 40/60 mixture whose pH is adjusted to 6 with acetic acid is used.
Eluent flow rate: 1.0 ml / min
column:
TSK-GEL guard column (inner diameter 6mm, length 40mm)
+ TSK-GEL G-4000SWXL (inner diameter 7.8 mm, length 300 mm)
+ TSK-GEL G-3000SWXL (inner diameter 7.8 mm, length 300 mm)
+ TSK-GEL G-2000SWXL (inner diameter 7.8 mm, length 300 mm)
(Both are trade names, manufactured by Tosoh Corporation)
Column oven temperature: 40 ° C
[0081]
Calibration curve: The calibration curve varies depending on the molecular weight and number of standard samples, how to draw a baseline, the method of preparing a calibration curve approximation formula, and the like. For this reason, it is preferable to set the following conditions.
1. Standard sample
As the standard sample, commercially available standard polyethylene oxide (PEO) and standard polyethylene glycol (PEG) are used. It is preferable to use a standard sample having the following molecular weight.
1470, 4250, 7100, 12600, 24000, 46000, 85000, 219300, 272500 (9 points in total)
These standard samples were selected in consideration of the following points.
(1) Use 7 or more standard samples having a molecular weight of 900 or more.
(2) At least one standard sample having a molecular weight of 900 to 2000 is included.
(3) At least three standard samples having a molecular weight of 2000 to 60000 are included.
(4) At least one standard sample having a molecular weight of 200,000 ± 30000 is included.
(5) At least one standard sample having a molecular weight of 270000 ± 30000 is included.
[0082]
2. How to draw a baseline
Upper limit of molecular weight: The peak rises from a horizontal and stable baseline.
Lower limit of molecular weight: The point where the detection of the main peak is completed.
3. Approximation formula of calibration curve
A calibration curve (“elution time” vs. “log molecular weight”) prepared using the above standard sample is prepared as an approximate expression of a cubic equation and used for the calculation.
[0083]
The cement dispersant containing the above-mentioned polycarboxylic acid polymer can exhibit good cement dispersion performance and slump retention performance, but if necessary, known cement additives (cement other than polycarboxylic acid polymer) A dispersant may be further blended.
[0084]
In the above cement dispersant, air entraining agent, cement wetting agent, swelling agent, waterproofing agent, retarder, quick setting agent, water-soluble polymer substance, thickener, flocculant, drying shrinkage reducing agent, strength enhancer, A hardening accelerator, an antifoamer, etc. can be mix | blended.
The cement dispersant obtained in this way is a cement composition containing cement and water, such as, for example, hydraulic cement such as Portland cement, high belite cement, alumina cement, various mixed cements, and cement such as gypsum. It will be used for other hydraulic materials.
[0085]
As the addition amount of the cement dispersant to the hydraulic material, an excellent effect is exhibited even when added in a small amount as compared with conventional cement dispersants. For example, mortar or concrete using hydraulic cement, etc. When the weight of cement is 100% by weight, a ratio of 0.001 to 5% by weight may be added at the time of mixing. If the amount is less than 0.001% by weight, the effect of the cement dispersant may not be sufficiently exhibited. If the amount exceeds 5% by weight, the effect substantially reaches its peak, which is disadvantageous in terms of economy. There is a fear. More preferably, it is 0.01 to 1 weight%. As a result, various effects such as achievement of a high water reduction rate, improvement in slump loss prevention performance, reduction in unit water volume, increase in strength, and improvement in durability are exhibited.
[0086]
DETAILED DESCRIPTION OF THE INVENTION
The method for producing a dehydration reaction product of the present invention will be described with reference to FIG. 2 showing a schematic diagram of one embodiment of the apparatus configuration. Such an embodiment is a typical example of the present invention, and the embodiment of the present invention is not limited to this.
[0087]
In FIG. 2, the temperature is first raised to a predetermined temperature to perform a dehydration reaction step, then the temperature is lowered to a predetermined temperature to perform a neutralization step, and then the temperature is raised to a predetermined temperature to perform a dehydrating solvent evaporating step. The device configuration is shown. In such an apparatus configuration, the distillate containing the reaction product water generated during the dehydration reaction is distilled in the reaction tank 101, and after condensing and liquefying in the condenser 125 while preventing the generation of gelled substances, A circulation mechanism is formed in which the reaction product water is separated and removed by the separator 127, and the remaining distillate is refluxed by the pump 142 at a predetermined solvent circulation rate and returned to the reaction tank 101. In such a circulation mechanism, the upper part of the reaction tank 101 and the top of the vertical multi-tube type circular tube condenser 125 of the countercurrent or cocurrent contact type are connected by the connecting pipe 123, and the bottom bottom of the condenser 125 is separated from the water. The upper part of the vessel 127 is connected by a supply pipe (pipe) 129, whereby the reaction tank 101 and the water separator 127 are connected by the supply pipe 129.
Below, the case where an esterification reaction is performed as a dehydration reaction is demonstrated.
[0088]
The reaction tank 101 is provided with an external jacket 102 that can use hot water, Kajo steam, or the like as a heat medium as a heat exchange means. In the reaction tank 101, temperature sensors (not shown) for measuring the reaction temperature are attached to several appropriate parts. Such a temperature sensor is electrically connected to a control unit main body (not shown) in order to keep the reaction temperature at a specified temperature. Examples of the device mechanism include a jacket 102 attached to the reaction vessel 101.
[0089]
The water separator 127 in the above embodiment is made of SUS304, and a baffle plate 131 is provided in the interior, and two chambers (A) 133 and a chamber (B) 134 separated by the baffle plate 131 are formed. Has been. In this water separator 127, the supply pipe 129 has an opening in the liquid phase part of the chamber (A) 133 and also has an opening in the gas phase part by a plurality of holes 162 formed in the side surface of the supply pipe 129. And the opening of the gas phase portion is in the direction opposite to the baffle plate 131. In FIG. 2, the arrow inside the water separator 127 indicates the flow direction of the distillate from the open port, and a plurality of holes 162 of the supply pipe 129 are shown in an enlarged view. Further, the lower diameter of the water separator 127 is smaller than the upper diameter. Further, an interface meter (A) 136 is provided as a detection device for the interface between the dehydrated solvent and the produced water, and an interface meter (B) 138 is provided as a device for detecting the gas-liquid interface between the gas phase portion and the liquid phase portion (dehydrated solvent). The antigelling agent is allowed to act on the inside of the interface meter (A) 136 and the interface meter (B) 138.
[0090]
The water separator also has a condenser 128 attached to the gas phase. Since the dehydrated solvent, volatile (meth) acrylic acid, and the like in the gas phase portion of the water separator are sufficiently cooled by the condenser 128, they are not released out of the system. Further, the condenser 128 is provided with an open port (so-called vent), so that even when the reaction tank is heated, the pressure in the reaction system does not increase excessively, and the instrument is prevented from being damaged.
[0091]
In the water separator 127, the lower part of the chamber (A) 133 on the side where the distillate condensed by the condenser 125 is stored is connected to the generated water treatment tank 135 by a pipe 137, and the pipe 137 has a control. A valve 140 is provided, and a wastewater pipe 139 is connected to the processing tank 135. The lower part of the other chamber (B) 134 of the water separator 127 is connected to the reaction tank 101 by a pipe 141, and this pipe 141 is also provided with a control valve (not shown), and the generated water in the reaction tank 101 A pipe 145 connected to a dehydrated solvent storage tank 143 for storing the azeotropic dehydrated solvent is joined (connected). A circulation pump 142 is installed on the path of the pipe 141 before the junction (water separator 127 side), and a flow meter 144 is installed on the path of the pipe 141 behind the junction (on the reaction tank 101 side). Is provided. Further, the flow meter 144 is electrically connected to a flow rate measurement system main body (not shown) for integrating the measured flow rate and calculating the solvent circulation rate.
[0092]
The reaction tank 101 includes a raw material storage tank 103 made of stainless steel (for example, SUS304) for alcohol raw material, a raw material storage tank 105 for (meth) acrylic acid raw material, a catalyst storage tank 107 for acid catalyst, and dehydration A neutralizing agent storage tank 111 made of carbon steel (for example, high carbon steel) storing a neutralizing agent (neutralizing agent aqueous solution) for neutralizing the acid catalyst after the reaction is provided, and pipes 113 and 115, respectively. 117 and 121 are connected. The pipe 117 is provided with a pump 167. Further, a polymerization inhibitor storage tank 109 storing a polymerization inhibitor for preventing polymerization in the reaction system (reaction tank 101) during the dehydration reaction is connected via a pump 169 via a pipe 119.
[0093]
In the raw material storage tank 105, (meth) acrylic acid is easily polymerized. For example, methacrylic acid is polymerized by long-term storage, heat, or the like. Is added to (meth) acrylic acid. In FIG. 2, a circulation path 151 having an external jacket 150 (thermal insulation means) using a pump 116 is provided to keep the temperature constant at 30 to 40 ° C., and the (meth) acrylic acid raw material is always kept at 30 to 40 ° C. The apparatus configuration is such that it is held and circulated so as not to be polymerized.
[0094]
The raw material storage tank 105, the pipe 115, the pump 116, and the circulation path 151 are subjected to lining processing with a corrosion-resistant material such as synthetic resin in order to prevent corrosion due to corrosive (meth) acrylic acid. Is preferably used. Similarly, the catalyst storage tank 107, the pipe 117, and the pump 167 are also subjected to lining processing using acid-resistant materials such as Teflon (trade name) and synthetic resin such as vinyl chloride in order to prevent corrosion by the acid catalyst. It is preferable to use a magnet pump as the pump 167. The polymerization inhibitor storage tank 169 and the anti-gelation agent storage tanks 147 and 159 are each provided with a stirring device (not shown). In the case where the powdery polymerization inhibitor is dissolved in a solvent, it is preferable that the powdery polymerization inhibitor is sufficiently stirred and completely dissolved. However, if a solution of a polymerization inhibitor or an antigelling agent that is not completely dissolved for some reason is transferred by the pumps 160, 169, and 179, the pump may become blocked and stop. Such a situation cannot occur as long as dissolution is sufficient, but pumps 160, 169, and 179 are preferably pumps that can continue the transfer without delay even if a small amount of slurry liquid is transferred. Moreover, when transferring the polymerization inhibitor or the gelation inhibitor dissolved in the solvent, it is preferable to use a pump sealed with a chemical-resistant material such as Teflon or Viton (both are trade names). As a pump that satisfies such conditions, it is optimal to provide an appropriate seal to the MONO pump (manufactured by Hyojin Equipment Co., Ltd.). Further, a pipe 153 for recovering the esterified product synthesized in the reaction tank 101 by the esterification reaction is connected to the lower part of the reaction tank 101.
[0095]
In FIG. 2, a spray nozzle 126 is provided at the top of the condenser 125 in order to suppress the generation of gel-like substances in the condenser 125. The spray nozzle 126 is used for preventing gelation of distillate. The antigelling agent storage tank 147 for storing the antigelling agent is connected to the piping 149 via a pump 179. Similarly, a spray nozzle (not shown) is provided in the vicinity of the connection portion between the reaction tank 101 and the connecting pipe 123 so as to spray from the connecting pipe 123 side toward the reaction tank 101 side. The water separator 127 and the pipe 141 are connected.
[0096]
Part of the circulation mechanism is to distill distillate containing dehydrated solvent from the solution containing esterified product, which is a product in the system (inside reaction tank 101), after the dehydration reaction, thereby preventing the generation of gel-like substances. While being condensed and liquefied, it is also used as a circulation mechanism for removing distillate containing a dehydrated solvent out of the system. In such a circulation mechanism, a vacuum pump (ejector) 155 is attached to the water separator 127 in order to remove the dehydrated solvent by vacuum suction through a pipe 157. Further, in FIG. 2 above, an aqueous solution in which a water-soluble polymerization inhibitor is newly dissolved in the spray nozzle 126 newly provided at the top of the condenser 125 in order to sufficiently prevent gelation in the aqueous phase in the distillate. A water-soluble gelation inhibitor storage tank 159 for storing (hereinafter, also simply referred to as “water-soluble gelation inhibitor”) is connected by a pipe 161.
[0097]
In FIG. 2 described above, the dehydration reaction product is produced by the above apparatus configuration as described below.
First, as a dehydration reaction step, pipes 113, 115, 117, and 119 are provided in the reaction tank 101 from the raw material storage tanks 103 and 105, the catalyst storage tank 107, the polymerization inhibitor storage tank 109, and the dehydration solvent storage tank 143. In addition, a predetermined amount of alcohol and (meth) acrylic acid, an acid catalyst, a polymerization inhibitor, and a dehydrating solvent as reaction raw materials are charged through a pipe 141 through a pipe 145, and appropriately set reaction temperature, jacket temperature, pressure, etc. The esterification reaction is performed under the following reaction conditions. As a result, the produced water successively produced is azeotroped with the dehydrated solvent charged in the reaction tank 101 and distilled through the connecting pipe 123. The gas fluid that has been distilled, that is, the distillate that is a solvent-water azeotrope, is passed through the condenser 125 to be condensed and liquefied. Further, in FIG. 2 described above, a predetermined amount of the antigelling agent is continuously sprayed from the spraying nozzle 126 provided at the top of the condenser 125 from the antigelling agent storage tank 147 through the pipe 149, and the gas fluid or condensation is sprayed. It is in contact with a distillate that is a liquefied product.
[0098]
Next, the condensed and liquefied distillate is stored in the chamber (A) 133 of the water separator 127 through the supply pipe 129 from the lower part of the condenser 125, and is divided into two layers of an aqueous phase (lower phase) and a solvent phase (upper phase). Will be separated. At this time, since the opening of the supply pipe 129 is set as described above, even if the pressure of the distillate supplied to the water separator 127 fluctuates, the occurrence of bumping and the detection accuracy of the interface are improved. Problems such as lowering, liquid fluctuation at the interface, and formation of a gel-like substance are sufficiently suppressed. Further, the generated water of the lower phase is sequentially extracted through the pipe 137 and stored in the generated water treatment tank 135. At this time, the interface valve (A) 136 detects the interface between the aqueous phase and the solvent phase, and the control valve provided in the pipe 137 keeps the interface in the narrow portion below the water separator 127. It is controlled by adjusting the extraction amount (distillation amount) of the aqueous phase. Then, after being chemically or biologically treated so as to satisfy the environmental standard (waste water standard) value in the treatment tank 135 as necessary, the waste water is discharged outside the apparatus system through the pipe 139. On the other hand, in the chamber (A) 133, the upper solvent phase containing the gelation inhibitor sprayed from the nozzle 126 overflows the baffle plate 131 and is stored in the adjacent chamber (B) 134. Then, the solvent phase is refluxed at a predetermined solvent circulation speed through the pipe 141 via the pump 142 and returned to the reaction tank 101. At this time, the solvent circulation speed is adjusted by the control valve and the pump 142 provided in the pipe 141. In these operations, since the water separator 127 has the above-described structure, the effects of the present invention are fully exhibited, the occurrence of defects in the production process is suppressed, and the performance and quality of the esterified product to be produced are reduced. It is possible to sufficiently suppress the decrease. At this time, a part is sprayed through a spray nozzle provided in the vicinity of the connection between the reaction tank 101 and the connecting pipe 123 to prevent gelation in the vicinity of the connection between the reaction tank 101 and the connecting pipe 123.
[0099]
Further, as a neutralization step, after completion of the dehydration reaction, the temperature is lowered and the internal temperature (liquid temperature) of the reaction vessel 101 is lowered through the refrigerant to the outer jacket 102 of the reaction vessel 101 until the temperature falls to, for example, 60 ° C. or lower. Add an alkaline aqueous solution (neutralizing agent) diluted to a predetermined concentration with a large amount of water into the reaction tank 101 from the neutralizing agent storage tank 111 through the pipe 121 while appropriately adjusting to maintain the temperature below a predetermined temperature. By doing so, a part of the acid catalyst or (meth) acrylic acid is partially neutralized.
[0100]
After the neutralization step is completed, as the solvent distillation step, dehydration in the reaction vessel 101 is performed by heating the external jacket 102 of the reaction vessel 101 to a predetermined temperature through a heating medium (pressurized steam) under normal pressure. In addition to the solvent and water added during the partial neutralization treatment, (meth) acrylic acid and the like are azeotropically distilled through the connecting pipe 123. The solvent-water azeotrope, which is a gaseous fluid that has been distilled off, is passed through the condenser 125 to be condensed and liquefied.
[0101]
The distillate condensed in the solvent distillation step is treated in the same manner as the distillate condensed in the dehydration reaction step, except that the distilled dehydrated solvent is not refluxed to the reaction vessel 101. Become.
In the solvent distillation step, a larger amount of water enters the condenser 125 together with the solvent than in the dehydration reaction step. In order to prevent the polymerizable compound from gelling on the aqueous phase side, a predetermined amount of water-soluble gelation is obtained from the water-soluble gelation inhibitor storage tank 159 through the pipe 161 through the spray nozzle 126 provided at the top of the condenser 125. It is preferable that the inhibitor is continuously dropped and brought into contact with the distillate.
[0102]
After the solvent evaporating step, adjusted water is added to the reaction tank 101 from a water storage tank (not shown) or a water pipe (not shown) connected by a pipe (not shown). An aqueous solution of the dehydration reaction product is obtained. The resulting aqueous solution of the dehydration reaction product is recovered (stored) from the pipe 153.
[0103]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. “Part” means “part by weight” unless otherwise specified, and “%” means “% by weight”.
[0104]
Example 1
A cylindrical reaction vessel with an external jacket equipped with a thermometer, a stirrer, a water separator, and a columnar reflux condenser (condenser) each was 12340 parts of methoxypoly (n = 10) ethylene glycol, 6000 parts of methacrylic acid, 381 parts of sulfuric acid. Then, 4 parts of phenothiazine and 5300 parts of cyclohexane were charged, and an esterification reaction was performed at a reaction temperature of 85 ° C.
The reaction tank has an outer diameter of 3.6 m (including the thickness of the jacket), a height of 3.8 m, and an internal volume of 30 m.^Three The connecting tube having an inner diameter of 0.2 m can be connected to the position of 1.15 m from the center of the reaction vessel. The condenser is a vertical multi-tube heat exchanger (fixed tube plate type) with an outer diameter of 0.9 m and a height of 4 m. The length is 3.5 m inside, the outer diameter is 24 mm, and the thickness is 2 mm. This structure has 624 heat transfer tubes and can spray the inhibitor solution on the top of the tower.
[0105]
The water separator is a cylindrical tank, as shown in FIG. 1, provided with a supply pipe and a baffle plate, provided with interface meters (A) and (B), and constituted by an upper part and a lower part. did. These materials were made of SUS304. The upper part was 2.6 m in height and the inner diameter was 2.2 m, and the lower part was 0.36 m in height and the inner diameter was 0.2 m. The baffle plate was a flat plate, and was installed at a position 0.55 m from the center of the cylinder so that the height from the bottom of the upper part was 2 m. Furthermore, the supply pipe is a circular pipe, the inner diameter is 25 mm, the position where the height from the bottom of the upper part is 0.4 m is the opening of the liquid phase part, and it becomes the interface between the gas phase part and the liquid phase part Four circular holes with a diameter of 13 mm (1/2 inch) were formed at equal intervals in the vertical direction in the opposite direction to the baffle plate at positions 30 to 100 mm above the position to provide an opening for the gas phase part. The interface meters (A) and (B) were provided with nozzles so that an antigelling agent could be injected.
[0106]
Separately, 0.5 part of phenothiazine and 578 parts of cyclohexane were mixed in the dissolution tank, and the MONO pump (manufactured by Hyojin Equipment Co., Ltd.) was passed to the top of the condenser from the beginning of the reflux of cyclohexane (internal temperature 82 ° C) to the end of the esterification reaction. Was sprayed from a spray nozzle. Moreover, cyclohexane was sprayed also from the spray nozzle also to the connection part of the reaction tank, and 1 part of phenothiazine was added to the interfacial meters (A) and (B) once every 5 times to prevent polymerization of methacrylic acid. It was confirmed that the esterification rate reached 99% in about 24 hours. The reaction rate was monitored from time to time with the total amount of reaction product water. During this reaction, the amount of reaction product water extracted was adjusted by a control valve so that the interface between cyclohexane and water was kept in the lower part of the water separator. Cyclohexane was refluxed from the water separator to the reaction vessel.
[0107]
To the obtained esterification reaction solution, 967 parts of a 49% aqueous sodium hydroxide solution and 3800 parts of water were added at 50 ° C. or lower to neutralize a part of sulfuric acid and methacrylic acid. After neutralization, the temperature was raised to 98 ° C., and cyclohexane was distilled off azeotropically with water. During the distillation of cyclohexane, the gelation inhibitor solution in the dissolution tank was sprayed onto the top of the condenser tower. Further, steam was blown into the jacket of the connecting pipe from the upper part, and the drain and steam were extracted from two outlets (reaction tank side and condenser side) at the lower part to keep the temperature. Then, after cyclohexane was distilled off, cooling was performed to obtain an aqueous solution (M1) of the esterified product. The obtained aqueous solution (M1) was transferred to a separately provided container. The above operation was repeated 30 batches. During the 30 batch operations, the interface in the water separator was kept accurately and constant, and no bumping or the like was observed. Furthermore, there was no trouble due to gelation in the interface meter.
[0108]
Comparative Example 1
As the water separator, an aqueous solution of an esterified product was obtained in the same manner as in Example 1 except that the supply pipe did not have an opening on the side surface but only an opening in the liquid phase part. The above operation was repeated 30 batches, but twice of which, bumping occurred in the reaction tank, and a part of the reaction solution reached the water separation pipe through the condenser. Therefore, the reaction solution and the dehydrated solvent (cyclohexane) in the water separation tube were discarded, the dehydration reaction process was stopped, and the connecting tube, the condenser, and the water separation tube were washed.
[0109]
Comparative Example 2
An aqueous solution of an esterified product was obtained in the same manner as in Example 1 except that the initial setting amount of the interface of the water separator was incorrect and the interface became the upper part of the water separator. During the dehydration reaction process, the amount of reaction product water could not be accurately monitored, and it was not known whether the reaction rate target was achieved.
[0110]
Comparative Example 3
An aqueous solution of an esterified product was obtained in the same manner as in Example 1 except that phenothiazine (antigelling agent) was not added to the interface meter (A) and the interface meter (B) of the water separator. The above operation was repeated 30 batches, but once a problem occurred due to gelation in the interface meters (A) and (B) in the solvent distillation step. Gels adhered to each interface meter, and the interface and liquid level could not be monitored.
[0111]
Example 2
6000 parts of diethylenetriamine and 7309 parts of adipic acid were charged into a cylindrical reaction tank equipped with a thermometer, a stirrer, a water separator and a condenser (condenser), and stirred and mixed in a nitrogen atmosphere. The water separator was charged with 2 parts of methoquinone as a gel inhibitor in the cock part. The reaction tank has an outer diameter of 30 cm (heated with an oil bath), a height of 50 cm, and an inner volume of 0.03 m.^Three The connecting tube having an inner diameter of about 2 cm can be connected to a position 10 cm from the center of the reaction vessel. A commercially available glass funnel (cooling cylinder length 40 cm, manufactured by Shibata Scientific Instruments Co., Ltd.) was used as the capacitor. A commercially available water determination container (capacity 25 ml, with a cock, manufactured by Shibata Kagaku Kikai Kogyo Co., Ltd.) was used for the produced water separator and the connecting tube. This water separator also has the function of a level gauge because the amount of generated water can be read from a marked line engraved on the side surface of the glass when the cock is closed. The amount of reaction product water is monitored by reading the marked line indicated by the liquid level. When the maximum value of the marked line is reached, the bottom cock is twisted to discharge the reaction product water out of the system, Can be read. The reaction mixture was heated to 150 ° C. and reacted for 20 hours while removing the reaction product water accompanying the condensation polymerization to obtain 11332 parts of the condensation polymer (product water was 1977 parts). Next, 17 parts of hydroquinone methyl ether and 701 parts of methacrylic acid were charged, and an amidation reaction was performed at a reaction temperature of 150 ° C. As a result of carrying out the amidation reaction for 10 hours, 160 parts of the reaction product water was separated by a product water separator to obtain 11890 parts of an amidated product (M2) which is a polyamide polyamine. During the reaction, methacrylic acid contained in the produced water did not gel, and the cock was twisted at any time to discharge water out of the system, and the amount of produced water could be monitored.
[0112]
Comparative Example 4
An amidated product was obtained in the same manner as in Example 2 except that methoquinone (anti-gelling agent) was not added to the water separator having the function of a liquid level gauge. When the maximum value of the water separator marked line was reached, the cock was twisted to discharge the reaction product water out of the system, but gel was formed in the cock part, so the product water could not be discharged out of the system. From that point on, the amount of reaction product water could not be monitored.
[0113]
【The invention's effect】
Since the method for producing a dehydration reaction product of the present invention has the above-described configuration, it is possible to sufficiently suppress the occurrence of defects in the production process and the degradation of performance and quality of various chemical products. The resulting dehydration reaction product can be of high quality. Such dehydration reaction products include cement additives (cement dispersants), calcium carbonate, carbon black, pigment dispersants such as ink, scale inhibitors, gypsum / water slurry dispersants, coal / water slurry (CWM). It can be suitably used as a raw material for producing chemical products such as dispersants and thickeners.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an embodiment of a water separator according to the present invention.
FIG. 2 is a schematic view showing an embodiment of an apparatus configuration used in the method for producing a dehydration reaction product of the present invention.
[Explanation of symbols]
101 reactor
102, 150 jacket
103 Raw material storage tank for alcohol
105 Raw material storage tank for (meth) acrylic acid
107 catalyst storage tank
109 Polymerization inhibitor storage tank
111 Neutralizing agent storage tank
113, 115, 117, 119, 121, 130, 137, 139, 141, 145, 149, 153, 157, 161 Piping
116, 160, 167, 169, 179 Pump
123 Connecting pipe
125, 128 capacitors
126 Spray nozzle
127 water separator
129 Supply pipe (pipe)
131 baffle
133 Chamber inside water separator (A)
134 Inside the water separator (B)
135 Generated water treatment tank
136 Interface meter (A)
138 Interface meter (B)
140 Control valve
142 Circulation pump
143 Dehydrated solvent storage tank
144 Flow meter
147 Anti-gelling agent storage tank
151 Circulation route
155 vacuum pump
159 Water-soluble anti-gelling agent storage tank
162 Hole drilled in supply pipe 129

Claims (5)

A method for producing a dehydration reaction product comprising a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent,
The dehydration reaction step is performed using a reaction vessel and a water separator as essential,
The water separator is provided with a supply pipe connected to the reaction tank, and has a gas phase part and a liquid phase part inside,
The method for producing a dehydration reaction product, wherein the supply pipe has open ports in a gas phase portion and a liquid phase portion. The method for producing a dehydration reaction product according to claim 1, wherein the opening of the gas phase portion of the supply pipe is one or a plurality of holes formed in a side surface of the supply pipe. The water separator further includes a baffle plate,
3. The method for producing a dehydration reaction product according to claim 1, wherein an opening of the gas phase portion of the supply pipe is in a direction opposite to the baffle plate . The alcohol has the following general formula (1);
R ¹ O (R ² O) nH (1)
(In the formula, R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms. R ² O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. N represents R ² O. 4. The method for producing a dehydration reaction product according to claim 1, 2 or 3 , wherein the average added mole number of the oxyalkylene group is 0 to 300. The dehydration reaction product manufacturing method according to claim 1, 2, 3 or 4 dehydration reaction products, wherein the used as a raw material for the production of cement additives polymers.

Images