JP4197934B2 - Method for producing dehydration reaction product - Google Patents

Description

【００２０】
本発明の脱水反応生成物の製造方法においては、例えば、表１において、Ｃの品種を製造した後にＢの品種を製造する場合、（１）反応開始前の仕込み量を「ｂ＋ｙ」とし、反応終了後に調整を行わない形態であってもよく、（２）反応開始前の仕込み量を「ｂ−ｘ」とし、反応終了後、例えば、溶剤留去前や溶剤留去後に無条件で「ｘ＋ｙ」の原料を投入して、最終的に「ｂ−ｘ＋ｘ＋ｙ」＝「ｂ＋ｙ」の原料を反応槽に投入する形態でもよい。すなわち（２）の形態においては、仕込み量を最小とし、調整分は分析・確認せずに前品種による調整量を無条件で投入することになる。例えば、アルコールと（メタ）アクリル酸とを反応させてエステルと（メタ）アクリル酸との混合物を得る場合、アルコールのモル量に対して（メタ）アクリル酸の投入モル量が過剰であれば、一部の（メタ）アクリル酸を脱水反応工程終了後に投入してもよい。具体的な数値で示すと、ｂ＝３５７０（ｋｇ）、ｘ＝６０（ｋｇ）、ｙ＝１５（ｋｇ）、エステル（脱水反応生成物）になるメタクリル酸の量は、１３６７ｋｇである。メタクリル酸の仕込み量は、ｂ−ｘ＝３５１０（ｋｇ）として、脱水反応工程終了後ｘ＋ｙ＝７５（ｋｇ）としても、初めからｂ＋ｙ＝３５８５（ｋｇ）として仕込んでもよく、脱水反応工程に大きな影響は与えない。
【００２１】
上記エステル化及び／又はアミド化工程により、エステル及び／又はアミドと過剰分の（メタ）アクリル酸とを含む生成物を製造する場合、上述したように生産性を向上するために同一の反応装置を用いて数品種を繰り返し製造し、かつ酸が同一種類のときには、溶剤留去工程で留去した脱水溶剤、すなわち水分離器中の脱水溶剤をそのまま精製せずに用いることが好適である。この場合、溶剤留去工程で留去した脱水溶剤の組成により反応原料の反応槽への投入量が調整されていないと、例えば、重合体の品質を考慮して設定されるＴＣＡＶの値にバラツキが生じ、それに起因して重合体を含むセメント添加剤等の品質の安定性が充分ではなくなるおそれがある。本発明では、上記形態のように溶剤留去工程で留去した脱水溶剤の組成により反応原料の反応槽への投入量が調整されてなると、ＴＣＡＶの値のバラツキが抑制されて重合体を含むセメント添加剤等の品質の安定性が向上すると共に、上記形態のように前品種を加味した（メタ）アクリル酸の反応槽への投入量を把握し、これにより反応原料の反応槽への投入量が調整されてなると、ＴＣＡＶの値を調整する工程を省略することができ、これにより生産性を向上することも可能となる。
【００２２】
本発明においては、上記脱水反応生成物が、セメント添加剤の製造原料として用いられることが好ましい。すなわち本発明の製造方法を用いて製造される脱水反応生成物をセメント添加剤の製造原料として用いることが好ましい。これにより、セメント添加剤の製造において、その性質や品質が低下することが抑制されて安定的に製造することが可能となる。
【００２３】
以下では、本発明における反応装置や反応原料、反応方法等について説明する。上記反応槽とは、反応器や、反応容器、反応釜等と同じ意味内容で用いられるものであって、脱水反応を行うことができる容器であれば特に限定されるものではない。反応槽の形状は、特に限定されるものではない。多角型、円筒型等があるが、攪拌効率、取扱い性、汎用性等の点から円筒型が好ましい。また邪魔板の有無は問わない。反応槽の加熱方式は外部ジャケットにスチーム等の熱媒を接触させることによって加熱するものであっても良いし、反応槽の内部にコイル等の伝熱装置を備えていて加熱するものであっても良い。このような反応槽の内部の材質としては特に限定されず、公知の材質が使用できるが、例えば、ＳＵＳ製、好ましくは、耐蝕性の点から、ＳＵＳ３０４、ＳＵＳ３１６、ＳＵＳ３１６Ｌ、より好ましくは、ＳＵＳ３１６、ＳＵＳ３１６Ｌ等が挙げられる。また、反応槽の内部にグラスライニング加工等が施されて反応原料及び生成物に対して不活性なものとしてもよい。このような反応槽は、通常では脱水反応を均一に効率よく行うため攪拌機が備えられている。攪拌機は特に限定されるものではない。攪拌機は通常、電動モーター、軸、攪拌機から構成されるがその攪拌翼も形状を問わない。攪拌機としては、デスクタービン、ファンタービン、わん曲ファンタービン、矢羽根タービン、多段ファンタービン翼、ファウドラー翼、ブルマージン型、角度付き羽根、プロペラ型、多段翼、アンカー型、ゲート型、二重リボン翼、スクリュー翼、マックスブレンド翼等を挙げることができ、なかでも多段ファンタービン翼、ファウドラー翼が汎用性の点で好ましい。
【００２４】
上記コンデンサの材質としては、ＳＵＳ３０４、ＳＵＳ３１６、ＳＵＳ３１６Ｌ等のＳＵＳ製や炭素鋼（ＣＳ）等、公知のものが使用できる。ゲル状物の発生をより低減するために、内面を鏡面仕上げやグラスライニング加工されたコンデンサを使用できるが、加工やメンテナンスにかかるコストの点から、ＳＵＳ３０４、ＳＵＳ３１６、ＳＵＳ３１６Ｌ、好ましくは、ＳＵＳ３１６、ＳＵＳ３１６Ｌ等のＳＵＳ製のコンデンサを用いることが好ましく、このようなコンデンサを用いた場合でも、本発明の作用効果を発揮させることができる。
【００２５】
上記コンデンサの伝熱面積としては、反応槽の容積等によって異なるが、例えば、反応槽３０ｍ³では、５０〜５００ｍ²とすることが好ましい。より好ましくは、１００〜２００ｍ²である。このようなコンデンサに使用される冷却媒体としては、例えば、水やオイル等が挙げられる。
【００２６】
上記水分離器の容積としては、反応槽の容積や留出物の留出量等によって異なるが、例えば、反応槽３０ｍ³では、１〜２０ｍ³とすることが好ましい。より好ましくは、３〜１０ｍ³である。このような水分離器としては、供給管がコンデンサに接続され、邪魔板を有する構造のもの、すなわち反応槽で発生したガス状留出物がコンデンサにより凝縮液化され、供給管を通過して、邪魔板より供給管側の水分離器内の室（Ａ）に入り、室（Ａ）では下相に生成水が溜まり、上相には脱水溶剤が溜まり、そして室（Ａ）の上相に溜まった脱水溶剤は、邪魔板の上を越流して室（Ｂ）に入って溜まるような構造のものが好適である。室（Ａ）に溜まった生成水は、生成水出口から除去され、また、室（Ｂ）に溜まった脱水溶剤は、脱水溶剤出口から抜き出されることになる。
【００２７】
上記水分離器及びそれに備えられる供給管や邪魔板の材質としては特に限定されず、公知の材質が使用できるが、例えば、ＳＵＳ製、好ましくは、耐蝕性の点から、ＳＵＳ３０４、ＳＵＳ３１６、ＳＵＳ３１６Ｌ、より好ましくは、ＳＵＳ３１６、ＳＵＳ３１６Ｌ等が挙げられる。また、水分離器の内部にグラスライニング加工やテフロン（Ｒ）加工等が施されて反応原料及び生成物の腐食性に対して不活性なものとしてもよい。
【００２８】
次に、脱水反応生成物を製造する方法として、脱水反応工程、溶剤留去工程を含み、必要に応じて中和工程を含んでなる方法について説明する。
上記脱水反応工程は、アルコール及び／又はアミンと（メタ）アクリル酸とを必須とする反応原料を脱水溶剤の存在下でエステル化及び／又はアミド化する工程である。これらの反応原料とされる化合物はそれぞれ単独で用いてもよく、２種以上を併用してもよい。なお、本明細書中、上記のエステルやアミドをそれぞれエステル化物やアミド化物ともいう。
【００２９】
上記エステル化反応に使用されるアルコールとしては、水酸基を有する化合物であれば特に限定されず、例えば、アルコール類、フェノール類、ジオール類、３価以上のアルコール類、ポリオール類等が挙げられる。例えば、アルコール類としては、メタノール、エタノール、ｎ−プロパノール、ｎ−ブタノール、２−エチルブタノール、ｎ−オクタノール、１−ドデカノール、１−オクタデカノール、２−エチルヘキサノール、シクロヘキサノール、アリルアルコール、３−メチル−３−ブテン−１−オール等の１級アルコール；ｉｓｏ−プロピルアルコール、２−ブタノール、２−ペンタノール、３−ペンタノール、２−ヘプタノール、３−ヘプタノール、メチルアミルアルコール、２−オクタノール、ノニルアルコールや、日本触媒社製「ソフタノール（商品名）」等の炭素数１２〜１４のアルコール等の２級アルコール；ｔｅｒｔ−ブタノール、ｔｅｒｔ−ペンタノール等の３級アルコール等が挙げられ、フェノール類としては、フェノール、クレゾール、ｏ−クレゾール、ｍ−クレゾール、ｐ−クレゾール等が挙げられ、ジオール類としては、モノエチレングリコール、ジエチレングリコール、トリエチレングリコール、テトラエチレングリコール、ポリエチレングリコール、モノプロピレングリコール、ジプロピレングリコール、ポリエチレンポリプロピレングリコール、ジエタノールアミン、Ｎ−ブチルジエタノールアミン等が挙げられ、３価以上のアルコール類やポリオール類としては、グリセリン、トリメチロールプロパン、１，３，５−ペンタントリオール、ペンタエリスリトール、グルコース、フラクトース、ソルビトール、グルコン酸、酒石酸、ポリビニルアルコール等が挙げられる。
【００３０】
上記アルコールとしてはまた、本発明により製造される脱水反応生成物をセメント添加剤用重合体の製造原料として用いる場合には、下記一般式（１）で表される化合物を含有することが好ましく、このような化合物は、アルコールにおける主成分として含有されることが好ましい。この場合、アルコール中には付加的にその他の成分を含んでいても含んでいなくてもよい。すなわち本発明の脱水生成物の製造方法において、上記脱水反応生成物は、下記一般式（１）で表されるアルコールと、（メタ）アクリル酸のエステル化物であることが好ましい。
【００３１】
Ｒ¹Ｏ（Ｒ²Ｏ）ｎＨ （１）
式（１）中、Ｒ¹は、炭素数１〜３０の炭化水素基を表す。Ｒ²Ｏは、同一又は異なって、炭素数２〜１８、好ましくは炭素数２〜８のオキシアルキレン基を表す。ｎは、Ｒ²Ｏで表されるオキシアルキレン基の平均付加モル数を表し、０〜３００、好ましくは２〜３００の数である。なお、平均付加モル数とは、当該化合物１モル中における当該繰り返し単位のモル数の平均値を意味する。
【００３２】
上記Ｒ¹の炭素数が３０を超えたり、上記Ｒ²Ｏの炭素数が１８を超えたりすると、エステル化物を製造原料として得られる重合体の水溶性が低下し、セメント添加剤等に用いる場合の用途性能、すなわちセメント分散性能等が低下するおそれがある。また、上記ｎが３００を超えると、一般式（１）で表される化合物と（メタ）アクリル酸との反応性が低下するおそれがある。
【００３３】
上記Ｒ¹やＲ²Ｏの好適な炭素数の範囲は、エステル化物の使用用途により設定されることになる。例えば、エステル化物をセメント添加剤用重合体の製造原料として用いる場合には、Ｒ¹としては、例えば、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、ｔｅｒｔ−ブチル基、ペンチル基、ヘキシル基、オクチル基、ノニル基、２−エチルヘキシル基、デシル基、ドデシル基、ウンデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基、ノナデシル基、エイコシル基、ヘンエイコシル基、ドコシル基等のアルキル基；フェニル基等のアリール基；ベンジル基、ノニルフェニル基等のアルキルフェニル基；シクロヘキシル基等のシクロアルキル基；アルケニル基；アルキニル基等が挙げられる。これらの中でも、炭素数１〜１８の直鎖又は枝分かれ鎖のアルキル基及びアリール基とすることが好ましい。より好ましくは、メチル基、エチル基、プロピル基、ブチル基、フェニル基である。
【００３４】
上記Ｒ²Ｏとしては、例えば、オキシエチレン基、オキシプロピレン基、オキシブチレン基、オキシスチレン基等が挙げられ、これらの中でも、オキシエチレン基、オキシプロピレン基、オキシブチレン基が好ましい。なお、Ｒ²Ｏは、一般式（１）で表される化合物を構成する繰り返し単位であり、各繰り返し単位は同一であってもよく、異なっていてもよい。このうち、２種以上の異なる繰り返し単位を有する場合には、各繰り返し単位はブロック状に付加していてもよく、ランダム状に付加していてもよく、特に限定されるものではない。
【００３５】
上記ｎの範囲についても、エステル化物の使用用途により設定されることになり、例えば、エステル化物をセメント添加剤用重合体の製造原料として用いる場合には、２〜３００とすることが好ましい。より好ましくは、５〜２００であり、更に好ましくは、８〜１５０である。また、増粘剤等として用いる場合には、１０〜２５０とすることが好ましい。より好ましくは、５０〜２００である。
【００３６】
上記ｎが０の場合には、水との溶解性や沸点の点から、上記Ｒ¹は、炭素数４以上の炭化水素基であることが好ましい。すなわちｎが０の場合には、特にメタノールやエタノール等のアルコールでは低沸点のため生成水と共に蒸発して生成水中に溶解することにより、当該アルコール原料の一部が反応系外に留去され、目的とするエステル化物の収率が低下することから、これを防止するためである。
【００３７】
上記一般式（１）で表される化合物の過酸化物価としては、０．７ｍｅｑ／ｋｇ以下であることが好ましい。０．７ｍｅｑ／ｋｇを超えると、エステル化工程時にゲルが発生し濾過による除去工程が必要になるおそれや、セメント添加剤用重合体を製造する際、共重合工程時に異常な分子量分布、ゲルの発生やゲル化をもたらすおそれがある。それらの結果、得られる重合体のセメント分散性能やスランプ保持性能が大きく低下することになる。より好ましくは、０．５ｍｅｑ／ｋｇ以下、更に好ましくは、０．３ｍｅｑ／ｋｇ以下である。
【００３８】
上記一般式（１）で表されるアルコールとしては、例えば、メトキシ（ポリ）エチレングリコール、メトキシ（ポリ）エチレングリコール（ポリ）プロピレングリコール、メトキシ（ポリ）プロピレングリコール、メトキシ（ポリ）エチレングリコール（ポリ）ブチレングリコール、メトキシ（ポリ）エチレングリコール（ポリ）プロピレングリコール（ポリ）ブチレングリコール、メトキシ（ポリ）ブチレングリコール、エトキシ（ポリ）エチレングリコール、エトキシ（ポリ）エチレングリコール（ポリ）プロピレングリコール、エトキシ（ポリ）プロピレングリコール、エトキシ（ポリ）エチレングリコール（ポリ）ブチレングリコール、エトキシ（ポリ）エチレングリコール（ポリ）プロピレングリコール（ポリ）ブチレングリコール、エトキシ（ポリ）ブチレングリコール、フェノキシ（ポリ）エチレングリコール、フェノキシ（ポリ）エチレングリコール（ポリ）プロピレングリコール、フェノキシ（ポリ）プロピレングリコール、フェノキシ（ポリ）エチレングリコール（ポリ）ブチレングリコール、フェノキシ（ポリ）エチレングリコール（ポリ）プロピレングリコール（ポリ）ブチレングリコール、フェノキシ（ポリ）ブチレングリコール、アルキルフェノキシ（ポリ）エチレングリコール、アルキルフェノキシ（ポリ）エチレングリコール（ポリ）プロピレングリコール、アルキルフェノキシ（ポリ）プロピレングリコール、アルキルフェノキシ（ポリ）エチレングリコール（ポリ）ブチレングリコール、アルキルフェノキシ（ポリ）エチレングリコール（ポリ）プロピレングリコール（ポリ）ブチレングリコール、アルキルフェノキシ（ポリ）ブチレングリコール等が挙げられる。これらの中でも、セメント添加剤用重合体の製造原料として用いる場合には、エチレングリコール鎖を多く有するものが好ましい。
【００３９】
上記アミド化反応に使用されるアミンとしては特に限定されず、例えば、アンモニア；メチルアミン、エチルアミン、プロピルアミン、ブチルアミン、ドデシルアミン、セチルアミン等の脂肪族第一アミン類；ジメチルアミン、ジエチルアミン、ジプロピルアミン、ジアミルアミン等の脂肪族第二アミン類；トリメチルアミン、トリエチルアミン、トリプロピルアミン、トリブチルアミン等の脂肪族第三アミン類；アリルアミン、ジアリルアミン等の脂肪族不飽和アミン類；シクロプロピルアミン、シクロブチルアミン、シクロヘキシルアミン等の脂環式アミン類；アニリン、モノメチルアニリン、ジメチルアニリン、ジフェニルアニリン等の芳香族モノアミン類；ｏ−フェニレンジアミン、ｍ−フェニレンジアミン等の芳香族ジアミン類；α−ナフチルアミン、β−ナフチルアミン等のアミノナフタリン類；ジエチレントリアミン、トリエチレンテトラミン、テトラエチレンペンタミン、ペンタエチレンヘキサミン、ジプロピレントリアミン、トリプロピレンテトラミン、テトラプロピレンペンタミン等のポリアルキレンポリアミン類；モノエタノールアミン、ジエタノールアミン、ポリエチレングリコール（モノ）アミン、ポリエチレングリコール（ジ）アミン等のオキシエチレンアミン類；尿素、チオ尿素等の尿素類；ポリエチレンイミン、ポリエチレンイミンへのエチレンオキサイド付加物、ポリエチレンイミンへのプロピレンオキサイド付加物等の高分子類等が挙げられる。
【００４０】
上記エステル化反応やアミド化反応では、（メタ）アクリル酸と共に、その他のカルボキシル基を有する不飽和単量体を用いることができる。カルボキシル基を有する不飽和単量体とは、少なくともカルボキシル基と不飽和結合を有する単量体である。具体的には、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。
【００４１】
上記エステル化反応やアミド化反応において、アルコールやアミドの転化率は、性能面からは必ずしも１００％である必要はなく、好ましくは、９０％以上、より好ましくは、９５％以上、更に好ましくは、９８％以上である。エステル化反応やアミド化反応を行う方法としては特に限定されず、公知の触媒、重合禁止剤及び必要に応じて公知の溶剤を用いて公知の方法により行うことができる。
【００４２】
上記エステル化反応やアミド化反応に用いる触媒としては特に限定されず、公知のものを用いることができる。このような触媒としては、例えば、硫酸、パラトルエンスルホン酸、メタンスルホン酸等の酸触媒が挙げられる。また、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。このような重合禁止剤としては、公知のものを用いることができ、特に限定されず、例えば、ハイドロキノン、メトキノン等のキノン類；クペロン；フェノチアジン等が挙げられる。これらの触媒や重合禁止剤は、１種又は２種以上を用いることができる。また、エステル化反応やアミド化反応は、減圧下又は常圧下で行うことができる。
【００４３】
上記脱水反応工程においては、エステル化及び／又はアミド化を脱水溶剤の存在下で行うことになる。これにより、エステル化反応やアミド化反応で生成する生成水を効率よく共沸させることができることになる。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。
【００４４】
上記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み量を１００質量％とすると、０．１〜１００質量％とすることが好ましい。１００質量％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。０．１質量％未満であると、生成水を効率よく共沸させることができなくなるおそれがある。より好ましくは、２〜５０質量％である。
【００４５】
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、酸触媒及び（メタ）アクリル酸の一部又は全部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。
【００４６】
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。
【００４７】
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質量％とすると、２０質量％以下、好ましくは、０．１〜１０質量％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。
【００４８】
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、より低い温度で効率よく脱水溶剤を除去することができることになる。
【００４９】
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。
【００５０】
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コンクリート混和剤、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。
【００５１】
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。
【００５２】
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。
【００５３】
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。
【００５４】
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。
【００５５】
上記ポリカルボン酸系重合体の分子量としては、例えば、５００〜１００００００であることが好ましい。より好ましくは、３０００〜５０００００であり、更に好ましくは、５０００〜１０００００であり、最も好ましくは７０００〜５００００である。
【００５６】
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。
【００５７】
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。
【００５８】
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、セメントの質量を１００質量％とすると、０．００１〜５質量％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質量％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質量％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質量％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。
【００５９】
【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、「質量％」を意味する。
【００６０】
製造例１（溶剤留去工程で留出した脱水溶剤）
温度計、攪拌機、生成水分離器及び縦型多管式熱交換器（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１４５００部、フェノチアジン５部、メタクリル酸７０４５部、パラトルエンスルホン酸水和物の７０％水溶液６８０部及びシクロへキサン１０８０部を順に仕込み、反応温度１１０〜１２０℃でエステル化反応を行った。反応槽には、内径３．０ｍ、高さ３．８ｍの円柱の上部と下部を楕円曲面（２対１）とした俵型の反応槽を用いた。コンデンサには、縦型固定管板式熱交換器を作製して用いた。コンデンサは、塔頂部にゲル化防止剤の溶液を噴霧できる構造となっている。
【００６１】
反応槽とコンデンサとは連結管で結ばれている。反応槽で気化した留出ガスは、連結管を通じてコンデンサに到達して凝縮される。コンデンサで凝縮された凝縮液は水分離器に流入する。水分離器には邪魔板が備えられ、邪魔板を隔てて室（Ａ）と室（Ｂ）とが設けられている。凝縮液は供給管を通して室（Ａ）に流入する。室（Ａ）にはシクロヘキサン３１１０部、室（Ｂ）にはシクロヘキサン５３０部を予め仕込んだ。このとき室（Ａ）は邪魔板の上部まで満たされている。コンデンサより流入した凝縮液は分離器の室（Ａ）で水層（下層）と油層（上層）に分離する。水層と油層の界面は高さを一定に保つように、水層の凝縮水を抜き出す。油層の凝縮液は邪魔板を超えて室（Ｂ）に溢れ出す。室（Ｂ）の液面高さを一定にするようにポンプで反応槽に戻す。反応槽に仕込んだシクロヘキサンは、気化してコンデンサで凝縮され、水分離器を通って再び反応槽に戻り、エステル化反応中は循環することになる。
【００６２】
別途、溶解槽にフェノチアジン０．３部とシクロへキサン３００部とを混合し、シクロヘキサンの還流開始（内温１０６℃）からエステル化反応終了までの間、コンデンサの塔頂部にモーノポンプ（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て、メタクリル酸の重合を防止した。１８時間でエステル化率が９８．５％に達したのを確認した。得られたエステル化反応液２６２９０部に６５℃以下で４．２％水酸化ナトリウム水溶液４８５３部を加えてパラトルエンスルホン酸全部とメタクリル酸の一部とを中和した。中和後１０１℃まで再び昇温して、シクロヘキサンを水との共沸を利用して留去した。シクロへキサンを留去中、コンデンサの塔頂部へハイドロキノン１部を含む水３５０部を噴霧した。液温が１０１℃になったのを確認後、窒素を１８Ｎｍ³／Ｈｒの流量で流してバブリングした。分離器内の室（Ａ）と室（Ｂ）の液量は一定に保ち、留去した溶剤は溶剤保存タンクへ、共沸した留去水は別途設けたタンクへ移送した。
反応槽では、脱水反応生成物（１）の水溶液２６４５０部が得られた。
水分離器の脱水溶剤中のメタクリル酸濃度を調べたところ、３．１％であった。１１２部のメタクリル酸が水分離器の溶剤中に溶解していることになる。
【００６３】
製造例２〜製造例５（脱水反応生成物（２）〜（５）の製造例）
製造例１と同様の方法により、表２に示す合成条件で脱水反応生成物の水溶液（２）〜（５）を得た。移送終了後、水分離器の脱水溶剤の組成を調べたところ、表３に示される組成であった。なお、表２中の投入された原料における数値及び表３中の数値は、「重量部」を表す。
【００６４】
【表２】

【００６５】
【表３】

【００６６】
実施例１
製造例１に示す方法で脱水反応生成物（１）を製造した後、反応槽を洗浄し、再び製造例１に示す脱水反応生成物（１）を製造した。反応槽及び溶解槽に仕込む脱水溶剤（１）及び脱水溶剤（２）には、先の製造例１実施後の溶剤留去工程で留去された脱水溶剤を一部含む溶剤保存タンク中のシクロヘキサンを使用した。この脱水溶剤はシクロへキサンの他、メタクリル酸２．０％、メタクリル酸メチル０．１％等が含まれていた。水分離器の脱水溶剤としては、先の製造例１での溶剤留去工程終了後のものをそのまま使用した。この脱水溶剤にはシクロヘキサンの他、メタクリル酸３．１％、メタクリル酸メチル０．２％等が含まれていた。
得られた脱水反応生成物（１）のＴＣＡＶ（全カルボン酸価数）は、１１０．３ｍｇＫＯＨ／ｇ］、水分＝１７．４［％］であり、それぞれ目標範囲内であった。
【００６７】
実施例２
製造例１に示す方法で脱水反応生成物（１）を製造した後、反応槽を洗浄し、製造例３に示す脱水反応生成物（３）を製造した。反応槽及び溶解槽に仕込む脱水溶剤（１）及び脱水溶剤（２）には、先の製造例１実施後の溶剤留去工程で留去された脱水溶剤を一部含む溶剤保存タンク中のシクロヘキサンを使用した。水分離器の脱水溶剤としては、先の製造例１での溶剤留去工程終了後のものをそのまま使用した。反応槽に仕込むメタクリル酸量は、前品種を考慮して調整した。すなわち次の通り計算した。
製造例１実施後、脱水溶剤の循環によって水分離器から反応槽に供給されるメタクリル酸の量は、表３より１１２部である。また、製造例３に示す脱水反応生成物（３）を合成後、水分離器の脱水溶剤には３５部のメタクリル酸が含まれる。水分離器の脱水溶剤中に含まれるメタクリル酸が反応槽へのメタクリル酸の仕込み量に影響することを考慮し、メタクリル酸仕込み量を７７部減らすと２９３３部と計算される。溶剤保存タンク中のシクロへキサンに含まれるメタクリル酸の量は２．０％であり、反応槽に脱水溶剤（１）を１２０６部仕込むときには、メタクリル酸が約２４部含まれることになる。また、溶解槽の脱水溶剤（２）５６０部にはメタクリル酸が約１１部含まれる。これらの量を考慮して反応槽へのメタクリル酸仕込み量を調整すれば、品質が更に安定になると考えられる。反応槽には２９３０部のメタクリル酸を仕込んでエステル化を行った。
得られた脱水反応生成物（３）のＴＣＡＶを測定したところ、４０．７［ｍｇＫＯＨ／ｇ］であり、目標管理範囲である３９．９〜４１．１［ｍｇＫＯＨ／ｇ］の範囲内であった。
【００６８】
実施例３
製造例１に示す方法で脱水反応生成物（１）を製造した後、反応槽を洗浄し、製造例３に示す脱水反応生成物（３）を製造した。反応槽及び溶解槽に仕込む脱水溶剤（１）及び脱水溶剤（２）には、先の製造例１実施後の溶剤留去工程で留去された脱水溶剤を一部含む溶剤保存タンク中のシクロヘキサンを使用した。水分離器の脱水溶剤としては、先の製造例１での溶剤留去工程終了後のものをそのまま使用した。反応槽に仕込むメタクリル酸量は、前品種を考慮せずに３０１０部とした。
得られた脱水反応生成物（３）のＴＣＡＶを測定したところ、４２．５［ｍｇＫＯＨ／ｇ］であり、目標管理範囲である３９．９〜４１．１［ｍｇＫＯＨ／ｇ］の範囲外となった。目標とする脱水反応生成物（３）のＴＣＡＶの範囲とならなかったため、更にメタクリル酸と水を添加して組成を調整し、脱水反応生成物（２）として使用した。
【００６９】
実施例４
実施例３の後、前品種を考慮してメタクリル酸の仕込み量を調整することにした。脱水反応生成物（１）〜（４）を、（１）→（３）→（２）→（４）→（３）→（２）→（４）→（３）→（１）→（２）→（３）の順で製造して全て目標範囲内であった。
【００７０】
比較例１
製造例５を行うに当たって、反応槽、溶解槽、分離器に仕込むシクロヘキサンは、予め次の操作を行って、脱水溶剤からメタクリル酸を取り除いて使用した。即ち、脱水溶剤に溶存しているメタクリル酸の濃度を測定し、中和に必重な量の水酸化ナトリウム水溶液を投入して１時間攪拌し、３０分間静置して、下層の中和水を抜き出して、上層の残存メタクリル酸濃度が０％であることを確認した。中和水は廃水とした。シクロへキサンからメタクリル酸を除去するには、このような洗浄作業が必要となる他、分離器の溶剤の入れ替え作業が増えて生産性が低下し、廃水が発生した。
【００７１】
実施例５
温度計、攪拌機、滴下装置、窒素導入管及び円柱型還流冷却管を備えたグラスライニング製反応容器に、水８３８０部を仕込み、攪拌しながら、反応容器内を窒素ガスで置換し、窒素雰囲気下で水の温度を８０℃まで加熱した。更に、実施例２で得られた脱水反応生成物（３）１３３００部をメルカプトプロピオン酸６２部に水６００部を加えた水溶液とスタティックミキサー（ノリタケ社製、商品名「Ｔ８−１５−４ＰＴ」）で混合しながら４時間かけて反応容器内に滴下し、この滴下開始と同時に重合開始剤として過硫酸アンモニウム１２５部を水１０００部に溶解した水溶液を５時間かけて滴下した。重合開始剤の滴下終了後、更に１時間引き続いて反応温度を８０℃に維持して重合反応を完結させ、４９％水酸化ナトリウム水溶液７８０部及び水３７７０部を加えてｐＨ７．２まで中和して、重量平均分子量３３０００の本発明の重合体水溶液（１）を得た。
【００７２】
【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、脱水溶剤を再利用することにより、効率的に製造コストを削減することができる。また、品質が前品種によらずに安定化され、同一の反応装置を用いて、数品種を効率よく安定的に製造することができるうえ、製品毎の反応装置が不要となり、同一種類の酸を用いる場合には、溶剤留去工程で留去した脱水溶剤をそのまま精製せずに次の脱水反応工程で用いることが可能となり、脱水溶剤の入れ替えや、脱水溶剤の精製（酸との分離）が不要となり、効率よく脱水反応生成物を製造することができる。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）やコンクリート混和剤、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】本発明の脱水反応生成物の製造方法に用いられる脱水反応装置の装置構成を例示した概念図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a dehydration reaction product obtained by esterification and / or amidation of alcohol and / or amine and (meth) acrylic acid, a dehydration reaction apparatus used therefor, and production of a cement additive obtained therefrom. Regarding the method.
[0002]
[Prior art]
A method for producing a dehydration reaction product comprising a dehydration reaction step has been 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), concrete admixtures, calcium carbonate, carbon black, pigment dispersants such as ink, scale inhibitors, gypsum / water slurry dispersants, coal / water It is suitably used for chemical products such as a slurry (CWM) dispersant and a thickener.
[0003]
By the way, in the dehydration reaction step, esterification reaction, amidation reaction, etc. are reactions that reach chemical equilibrium. Therefore, if the by-product water produced is not removed from the reaction system, that is, if the product water accumulates in the reaction system, And the reaction to produce amidated compounds do not proceed. Therefore, the generated water is removed by distilling (azeotropically) this and the generated water using a dehydrated solvent. For example, there is a method of separating and removing generated water from the distillate, refluxing the dehydrated solvent to the reaction system, performing the reaction, and removing the dehydrated solvent by removing it from the reaction tank containing the esterified product or amidated product after the reaction is completed. It has been taken.
[0004]
As a conventional technique, polyalkylene glycol (meth) acrylate obtained by esterification reaction of polyalkylene glycol and (meth) acrylic acid under a specific ratio and under specific conditions is copolymerized with (meth) acrylic acid. It is disclosed that the polycarboxylic acid obtained in this way is suitably used as a cement admixture (for example, see Patent Document 1).
Such a cement admixture is excellent in cement dispersion performance and slump retention performance, for example, when the performance is appropriately adjusted and various varieties are manufactured with the same manufacturing equipment, In addition, there is room to devise so that the quality is uniform and stable.
[0005]
In other words, stable production of high-quality dehydration reaction products while suppressing production costs makes it possible to improve the quality of dehydration reaction products that exhibit superior performance and to stabilize costs. There was room to devise so that it might supply.
For example, in the concrete industry, there is a strong demand for improving the durability and strength of concrete buildings, and these performances are improved by increasing the dispersibility of cement in the cement composition used in the manufacture of concrete buildings. Therefore, it is eagerly desired that a concrete admixture with higher quality and reduced cost can be stably supplied.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-60302 (pages 1 and 2)
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above situation, and is a method for producing a dehydration reaction product obtained by esterification and / or amidation of alcohol and / or amine and (meth) acrylic acid, and the quality is An object of the present invention is to provide a method for efficiently producing a dehydration reaction product that is stabilized regardless of the previous varieties, and has improved productivity.
[0008]
[Means for Solving the Problems]
As a result of diligent research to efficiently produce a high-quality dehydration reaction product, the present inventors have found that a reaction raw material essentially comprising alcohol and / or amine and (meth) acrylic acid is present in the presence of a dehydration solvent. A method for producing a dehydration reaction product comprising a dehydration reaction step of esterification and / or amidation with a solvent and a solvent distillation step of distilling off the dehydration solvent is a raw material for producing various polymers, particularly cement additives. First, paying attention to the fact that it is useful as a method for producing raw materials for polymers, the dehydrated solvent distilled in the solvent evaporating step is used in the dehydration reaction step, that is, the dehydrated solvent is reused for efficient production. We focused on the ability to reduce costs. When the dehydration reaction step and the solvent distillation step are repeated in the method for producing a dehydration reaction product, the productivity is improved if the dehydration solvent distilled in the solvent distillation step is used in the next dehydration reaction step. It has been found that a dehydration reaction product can be produced more efficiently. In addition, when the water generated during the reaction is distilled off together with the dehydrating solvent, low-boiling substances such as (meth) acrylic acid which is the reaction raw material are volatilized, and the reaction raw material is contained in the dehydrating solvent distilled off in the solvent distilling step. Finding that it mixes and adjusting the amount of (meth) acrylic acid charged into the reaction tank and the amount of alcohol charged into the reaction tank, taking into account the amount of the reaction raw material in the dehydrating solvent, that is, in the solvent distillation step By adjusting the amount of reaction raw material charged into the reaction tank according to the composition of the dehydrated solvent distilled off, the quality is stabilized regardless of the product type, and several products are manufactured efficiently and stably using the same reactor. I found that I could do it. This eliminates the need for a reaction apparatus for each product, and when the same type of acid is used, it becomes possible to use the dehydrated solvent distilled off in the solvent distilling step as it is in the next dehydrating reaction step without purification. It was thought that the replacement of the dehydrated solvent and the purification of the dehydrated solvent (separation from the acid) became unnecessary, and the above problem could be solved brilliantly.
Further, since the dehydration reaction product obtained by such a production method is of high quality, it has been found that it can be suitably used as a raw material for production of a polymer for cement additives and the present invention has been achieved. Is.
[0009]
That is, the present invention includes a dehydration reaction step of esterifying and / or amidating a reaction raw material essentially comprising alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, and a solvent for distilling off the dehydrating solvent. A dehydration reaction product comprising a distillation step, wherein a part or all of the dehydration solvent used in the dehydration reaction step is distilled in the solvent distillation step It is a manufacturing method.
The present invention is described in detail below.
[0010]
The method for producing a dehydration reaction product of the present invention includes a dehydration reaction step and a solvent distillation step, but it is preferable that the dehydration reaction step and the solvent distillation step are repeatedly performed. In such a manufacturing method, the same kind or different kinds are produced using the same reaction apparatus.
In the present invention, part or all of the dehydration solvent used in the dehydration reaction step is distilled in the solvent distillation step. That is, when the dehydrated solvent distilled off in the solvent distilling step is refluxed into the reaction vessel or the dehydration reaction step is repeated, the dehydrating solvent in the water separator is not replaced in the reaction vessel in the next reaction. It will be refluxed.
[0011]
It is preferable that the said process is performed using the dehydration reaction apparatus which makes a reaction tank, a capacitor | condenser, and the connecting pipe which connects these essential. With such a dehydration reaction apparatus, a condensation liquefaction operation can be performed using a condenser while performing a dehydration reaction in a reaction vessel. Moreover, it is preferable to carry out using the water separator which isolate | separates a dehydration solvent and water as an essential. In such a form, using a water separator, for example, the distillate vaporized in the reaction tank and condensed and liquefied by the condenser is separated into the dehydrated solvent and the produced water to remove the produced water.
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.
[0012]
As one of the preferable embodiments of the present invention, the dehydration reaction step and the solvent distillation step are repeatedly performed, and the dehydration reaction step requires a reaction tank and a water separator for separating the dehydration solvent and water. The dehydrated solvent distilled in the solvent distillation step in the water separator is used in the next dehydration reaction step.
[0013]
In the present invention, in the form as described above, in the dehydration reaction step, (1) in order to easily remove the generated water generated in the reaction tank, a dehydrating solvent is mixed with the reaction solution, and the dehydrating solvent and water are mixed. (2) The distillate passes through a connecting pipe connecting the reaction vessel and the condenser, enters the condenser, and the distillate is removed from the condenser in the condenser. Operation to condense and liquefy, (3) Operation to separate the condensed and liquefied distillate into dehydrated solvent and water in a water separator connected to the condenser, and (4) Reflux the separated dehydrated solvent into the reaction tank. The operations such as the operation to be performed are repeatedly performed. FIG. 1 is a conceptual diagram illustrating an apparatus configuration when performing such an operation.
[0014]
In FIG. 1, a reaction vessel, a condenser, a water separator, and a pump are installed, and a pipe for connecting them is provided. In addition, dehydrated solvent tanks 1 and 2 are installed, and piping for supplying the dehydrated solvent to the reaction tank and piping for cleaning the condenser and the like are provided. In this case, after the dehydrating solvent is supplied from the dehydrating solvent tank 1 to the reaction tank and the reaction is started, the distillate vaporized in the reaction tank passes through the connecting pipe and enters the condenser, and is condensed and liquefied in the condenser. The distillate thus obtained is separated into the dehydrated solvent and water in the water separator, whereby the produced water is removed from the reaction tank and the dehydrated solvent is refluxed into the reaction tank by the pump.
[0015]
In the method for producing a dehydration reaction product of the present invention, it is also preferable that the input amount of the reaction raw material to the reaction tank is adjusted by the composition of the dehydration solvent distilled off in the solvent distillation step. For example, by esterifying and / or amidating a reaction raw material essentially comprising an alcohol and / or amine and an excess amount of (meth) acrylic acid in the presence of a dehydrating solvent, the ester and / or amide and an excess amount are obtained. After carrying out the esterification and / or amidation step for producing a product containing (meth) acrylic acid, a polymerization initiator is added to this to carry out the polymerization step, so that it can be efficiently used as a cement additive or the like. A suitable polymer can be produced. In this case, the dehydrated solvent distilled off in the solvent evaporating step includes a low boiling point reaction raw material such as (meth) acrylic acid volatilized together with the dehydrated solvent. Accordingly, the reaction raw material to be charged into the reaction tank next is adjusted in consideration of the amount of the reaction raw material in the dehydrated solvent in such a water separator. Thus, it is preferable that the amount of (meth) acrylic acid, alcohol, and / or amine, etc. charged into the reaction vessel is adjusted by the amount of (meth) acrylic acid in the dehydrated solvent distilled off in the solvent distillation step. . In addition, when adjusting with the amount of alcohol and / or amine, the amount of finish may change, and the amount of other auxiliary materials (catalyst, dehydrating solvent, inhibitor, etc.) must be changed. More preferably, the amount of (meth) acrylic acid charged into the reaction vessel is adjusted by the amount of (meth) acrylic acid in the dehydrated solvent distilled off in the solvent distillation step.
The amount charged into the reaction tank means the total amount of raw materials charged into the reaction tank, and not only the amount charged before starting the reaction but also after completion of the reaction, for example, before or after the solvent is distilled off. The amount of raw material to be input is included.
[0016]
Examples of the method for measuring the composition of the dehydrated solvent distilled off in the solvent distillation step include a titration method and a (high-speed) liquid chromatography method. In addition, as a method for adjusting the amount of the reaction raw material charged into the reaction tank, for example, the amount of (meth) acrylic acid charged before the start of the reaction, the amount of charged alcohol and / or amine, etc. are appropriately increased or decreased, or after completion of the reaction. For example, it is performed by adjusting the amount of (meth) acrylic acid introduced before or after the solvent is distilled off.
[0017]
The quality of the product containing the ester and / or amide produced by the esterification and / or amidation step and an excess of (meth) acrylic acid depends on the quality of the polymer produced using the product. As a method of evaluating the quality of the product produced by the esterification and / or amidation step, the total amount of carboxylic acid in 1 g of product (in terms of mg of KOH), so-called TCAV ( It is preferable to carry out by measuring Total Carboxylic Acid Value). Thereby, it becomes possible to manage appropriately and simply the performance and quality of a cement additive containing a polymer produced using the product.
[0018]
In the method for producing a dehydration reaction product of the present invention, an embodiment in which the input amount of the reaction raw material to the reaction tank is adjusted by the composition of the dehydration solvent distilled in the solvent distillation step will be described.
Table 1 shows four varieties of products containing ester and / or amide and excess (meth) acrylic acid as A, B, C, and D, respectively, and the amount of (meth) acrylic acid charged into the reaction vessel. Is a conceptual diagram showing how the amount of (meth) acrylic acid charged into the reaction vessel will be changed according to the previously produced varieties, if they are manufactured repeatedly using the same reactor. It is. In the table, a, b, c and d are positive numbers and represent the amount of (meth) acrylic acid charged into the reaction vessel, and x, x ′, x ″, y, y ′ and z are Represents the adjustment amount of (meth) acrylic acid with respect to a, b, c and d, for example, the amount of (meth) acrylic acid required to produce varieties of A, B, C and D Assuming A, B, C, and D in descending order, the amount of (meth) acrylic acid charged into the reaction tank is a when the same type A is manufactured after the type A is manufactured. In the case of producing the same type of A after the production of A, the amount of (meth) acrylic acid charged into the reaction tank becomes a + x, and in the case of producing the same type of B after producing the type of A, (meth) The amount of acrylic acid charged into the reaction tank is b-x, which is also dehydrated as a dehydrating solvent. When not used, input amount to the reaction vessel of (meth) acrylic acid in the production of varieties of A is greater than a.
[0019]
[Table 1]

[0020]
In the method for producing a dehydration reaction product of the present invention, for example, in Table 1, when producing a variety of B after producing a variety of C, (1) the amount charged before starting the reaction is “b + y” (2) The amount of charge before the start of the reaction is “b−x”, and after completion of the reaction, for example, before the solvent is distilled off or after the solvent is distilled off, “x + y” The raw material of “b−x + x + y” = “b + y” may be finally charged into the reaction vessel. That is, in the form (2), the preparation amount is minimized, and the adjustment amount for the previous product is unconditionally input without analyzing and confirming the adjustment amount. For example, when a mixture of ester and (meth) acrylic acid is obtained by reacting alcohol and (meth) acrylic acid, if the molar amount of (meth) acrylic acid is excessive with respect to the molar amount of alcohol, A part of (meth) acrylic acid may be added after completion of the dehydration reaction step. When expressed by specific numerical values, b = 3570 (kg), x = 60 (kg), y = 15 (kg), and the amount of methacrylic acid to be an ester (dehydration reaction product) is 1367 kg. The amount of methacrylic acid charged may be set as b + x = 3510 (kg), x + y = 75 (kg) after completion of the dehydration reaction step, or b + y = 3585 (kg) from the beginning, which greatly affects the dehydration reaction step. Will not give.
[0021]
In the case of producing a product containing an ester and / or amide and an excess amount of (meth) acrylic acid by the esterification and / or amidation step, the same reactor is used to improve the productivity as described above. It is preferable to use the dehydrated solvent distilled off in the solvent distilling step, that is, the dehydrated solvent in the water separator as it is without purification. In this case, if the input amount of the reaction raw material to the reaction vessel is not adjusted by the composition of the dehydrated solvent distilled off in the solvent distillation step, for example, the value of TCAV set in consideration of the quality of the polymer varies. This may cause the quality stability of the cement additive containing the polymer to be insufficient. In the present invention, when the input amount of the reaction raw material to the reaction vessel is adjusted by the composition of the dehydrated solvent distilled off in the solvent distillation step as in the above embodiment, the variation in the TCAV value is suppressed and the polymer is contained. As well as improving the stability of the quality of cement additives, etc., the amount of (meth) acrylic acid added to the reaction tank, taking into account the previous varieties as in the above form, is ascertained. If the amount is adjusted, the step of adjusting the value of TCAV can be omitted, thereby improving the productivity.
[0022]
In the present invention, the dehydration reaction product is preferably used as a raw material for producing a cement additive. That is, it is preferable to use the dehydration reaction product produced using the production method of the present invention as a raw material for producing the cement additive. Thereby, in manufacture of a cement additive, the fall of the property and quality is suppressed, and it becomes possible to manufacture stably.
[0023]
Below, the reaction apparatus, reaction raw material, reaction method, etc. in this invention are demonstrated. 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 the 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.
[0024]
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 the above, and even when such a capacitor is used, the effects of the present invention can be exhibited.
[0025]
The heat transfer area of the capacitor varies depending on the volume of the reaction tank, etc. ^Three Then, 50-500m ² It is preferable that More preferably, 100-200m ² It is. Examples of the cooling medium used in such a condenser include water and oil.
[0026]
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. As such a water separator, the supply pipe is connected to the condenser, and has a structure having a baffle plate, that is, the gaseous distillate generated in the reaction vessel is condensed and liquefied by the condenser, passes through the supply pipe, It enters the chamber (A) in the water separator on the supply pipe side from the baffle plate, and in the chamber (A), the generated water accumulates in the lower phase, the dehydrated solvent accumulates in the upper phase, and the upper phase in the chamber (A). The accumulated dehydrated solvent preferably has a structure that flows over the baffle plate and enters the chamber (B) and accumulates. The produced water accumulated in the chamber (A) is removed from the produced water outlet, and the dehydrated solvent accumulated in the chamber (B) is extracted from the dehydrated solvent outlet.
[0027]
The material of the water separator and the supply pipe and baffle plate provided in the water separator are not particularly limited, and known materials can be used. For example, SUS304, SUS316, SUS316L, More preferably, SUS316, SUS316L, etc. are mentioned. Further, the inside of the water separator may be subjected to glass lining processing, Teflon (R) processing, or the like so as to be inert to the corrosiveness of the reaction raw materials and products.
[0028]
Next, as a method for producing a dehydration reaction product, a method including a dehydration reaction step and a solvent distillation step and, if necessary, a neutralization step will be described.
The dehydration reaction step is a step of esterifying and / or amidating a reaction raw material essentially comprising alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent. These compounds used as reaction raw materials 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.
[0029]
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.
[0030]
As the alcohol, when the dehydration reaction product produced according to the present invention is used as a raw material for producing a polymer for cement additive, it preferably contains a compound represented by the following general formula (1), Such a compound is preferably contained as a main component in alcohol. In this case, the alcohol may or may not contain other components. That is, in the method for producing a dehydrated product of the present invention, the dehydrated reaction product is preferably an esterified product of an alcohol represented by the following general formula (1) and (meth) acrylic acid.
[0031]
R ¹ O (R ² O) nH (1)
In formula (1), 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, preferably 2 to 8 carbon atoms. n is R ² 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.
[0032]
R above ¹ The number of carbons exceeds 30 or the above R ² 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. . Moreover, when said n exceeds 300, there exists a possibility that the reactivity of the compound represented by General formula (1) and (meth) acrylic acid may fall.
[0033]
R above ¹ Or R ² 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, R ¹ 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, etc. alkyl group; 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.
[0034]
R above ² 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. R ² 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.
[0035]
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.
[0036]
When n is 0, from the viewpoint of solubility in water and boiling point, R ¹ 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.
[0037]
The peroxide value of the compound represented by the general formula (1) is preferably 0.7 meq / kg or less. If it exceeds 0.7 meq / kg, a gel may be generated during the esterification process and a removal process by filtration may be necessary. When producing a polymer for cement additive, an abnormal molecular weight distribution may occur during the copolymerization process. May cause generation or gelation. As a result, the cement dispersion performance and slump retention performance of the resulting polymer are greatly reduced. More preferably, it is 0.5 meq / kg or less, and still more preferably 0.3 meq / kg or less.
[0038]
Examples of the alcohol represented by the general formula (1) include methoxy (poly) ethylene glycol, methoxy (poly) ethylene glycol (poly) propylene glycol, methoxy (poly) propylene glycol, methoxy (poly) ethylene glycol (poly ) Butylene glycol, methoxy (poly) ethylene glycol (poly) propylene glycol (poly) butylene glycol, methoxy (poly) butylene glycol, ethoxy (poly) ethylene glycol, ethoxy (poly) ethylene glycol (poly) propylene glycol, ethoxy (poly ) Propylene glycol, ethoxy (poly) ethylene glycol (poly) butylene glycol, ethoxy (poly) ethylene glycol (poly) propylene glycol (poly) butylene glycol , Ethoxy (poly) butylene glycol, phenoxy (poly) ethylene glycol, phenoxy (poly) ethylene glycol (poly) propylene glycol, phenoxy (poly) propylene glycol, phenoxy (poly) ethylene glycol (poly) butylene glycol, phenoxy (poly) Ethylene glycol (poly) propylene glycol (poly) butylene glycol, phenoxy (poly) butylene glycol, alkylphenoxy (poly) ethylene glycol, alkylphenoxy (poly) ethylene glycol (poly) propylene glycol, alkylphenoxy (poly) propylene glycol, alkyl Phenoxy (poly) ethylene glycol (poly) butylene glycol, alkylphenoxy (poly) ethylene glycol (polyethylene glycol) ) Propylene glycol (poly) butylene glycol, alkylphenoxy (poly) butylene glycol, and the like. Among these, when used as a raw material for producing a polymer for a cement additive, those having a lot of ethylene glycol chains are preferable.
[0039]
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.
[0040]
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.
[0041]
In the esterification reaction or amidation reaction, the conversion rate of alcohol or amide is not necessarily 100% from the viewpoint of performance, preferably 90% or more, more preferably 95% or more, and still more preferably, 98% or more. It does not specifically limit as a method of performing esterification reaction or amidation reaction, It can carry out by a well-known method using a well-known catalyst, a polymerization inhibitor, and a well-known solvent as needed.
[0042]
It does not specifically limit as a catalyst used for the said esterification reaction or amidation reaction, A well-known thing can be used. Examples of such a catalyst include acid catalysts such as sulfuric acid, paratoluenesulfonic acid, and methanesulfonic acid. The esterification reaction or amidation reaction is preferably performed in the presence of a polymerization inhibitor. As such a polymerization inhibitor, known ones can be used, and are not particularly limited. Examples thereof include quinones such as hydroquinone and methoquinone; cuperone; phenothiazine and the like. These catalysts and polymerization inhibitors can be used alone or in combination of two or more. The esterification reaction or amidation reaction can be carried out under reduced pressure or normal pressure.
[0043]
In the dehydration reaction step, esterification and / or amidation are performed in the presence of a dehydrating solvent. Thereby, the produced water produced | generated by esterification reaction or amidation reaction can be efficiently azeotroped. 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.
[0044]
As the usage-amount of the said dehydrating solvent, when the total preparation amount of the alcohol, amine, and acid which are reaction raw materials shall be 100 mass%, it is preferable to set it as 0.1-100 mass%. If it exceeds 100% by mass, an effect commensurate with 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. If it is less than 0.1% by mass, the produced water may not be efficiently azeotroped. More preferably, it is 2-50 mass%.
[0045]
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 part or all of the acid catalyst and (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.
[0046]
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.
[0047]
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 neutralized (meth) acrylic acid is 20% by mass or less, preferably 0.1 to 10%, assuming that the remaining (meth) acrylic acid after the esterification reaction or amidation reaction is 100% by mass. It is preferable that it is mass%. 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.
[0048]
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 efficiently removed at a lower temperature.
[0049]
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) is not sufficient to evaporate the dehydrated solvent. 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.
[0050]
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, concrete admixtures, calcium carbonate, carbon black, inks, scale inhibitors, The present invention is suitably applied as a raw material for producing polymers used in chemical products such as a dispersant for gypsum / water slurry, a dispersant for coal / water slurry (CWM), and a thickener.
[0051]
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.
[0052]
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.
[0053]
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.
[0054]
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.
[0055]
The molecular weight of the polycarboxylic acid polymer is preferably 500 to 1,000,000, for example. More preferably, it is 3000-500000, More preferably, it is 5000-100000, Most preferably, it is 7000-50000.
[0056]
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.
[0057]
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.
[0058]
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. In the case of use in the above, when the mass of the cement is 100% by mass, an amount of 0.001 to 5% by mass may be added at the time of mixing. When the amount is less than 0.001% by mass, the effect of the cement dispersant may not be sufficiently exhibited. When the amount exceeds 5% by mass, the effect is substantially peaked, which is disadvantageous from the viewpoint of economy. There is a fear. More preferably, it is 0.01-1 mass%. 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.
[0059]
【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 “mass%”.
[0060]
Production Example 1 (dehydrated solvent distilled in the solvent distillation step)
In a cylindrical reaction tank with an external jacket each equipped with a thermometer, stirrer, product water separator and vertical multitubular heat exchanger (condenser), 14500 parts of methoxypoly (n = 10) ethylene glycol, 5 parts of phenothiazine, 7045 parts of methacrylic acid, 680 parts of a 70% aqueous solution of paratoluenesulfonic acid hydrate and 1080 parts of cyclohexane were charged in this order, and an esterification reaction was performed at a reaction temperature of 110 to 120 ° C. A vertical reaction vessel having an elliptical curved surface (2 to 1) at the top and bottom of a cylinder having an inner diameter of 3.0 m and a height of 3.8 m was used as the reaction vessel. For the condenser, a vertical fixed tube plate heat exchanger was produced and used. The capacitor has a structure in which a solution of an antigelling agent can be sprayed on the top of the tower.
[0061]
The reaction vessel and the condenser are connected by a connecting pipe. The distillate gas vaporized in the reaction tank reaches the condenser through the connecting pipe and is condensed. The condensate condensed in the condenser flows into the water separator. The water separator is provided with a baffle plate, and a chamber (A) and a chamber (B) are provided across the baffle plate. The condensate flows into the chamber (A) through the supply pipe. The chamber (A) was charged with 3110 parts of cyclohexane and the chamber (B) with 530 parts of cyclohexane. At this time, the chamber (A) is filled up to the upper part of the baffle plate. The condensate flowing in from the condenser is separated into a water layer (lower layer) and an oil layer (upper layer) in the separator chamber (A). The condensed water in the water layer is drawn out so that the interface between the water layer and the oil layer is kept constant. The oil layer condensate overflows the baffle plate and overflows into the chamber (B). It returns to a reaction tank with a pump so that the liquid level height of a chamber (B) may become fixed. The cyclohexane charged in the reaction vessel is vaporized and condensed in the condenser, returns to the reaction vessel again through the water separator, and circulates during the esterification reaction.
[0062]
Separately, 0.3 parts of phenothiazine and 300 parts of cyclohexane were mixed in the dissolution tank, and a MONO pump (Hyojin equipment was installed at the top of the condenser tower from the start of reflux of cyclohexane (internal temperature 106 ° C) to the end of the esterification reaction. From the spray nozzle. Further, cyclohexane was sprayed from the spray nozzle to the connecting part of the reaction tank to prevent polymerization of methacrylic acid. It was confirmed that the esterification rate reached 98.5% in 18 hours. To 26290 parts of the obtained esterification reaction liquid, 4853 parts of a 4.2% sodium hydroxide aqueous solution was added at 65 ° C. or less to neutralize all of the paratoluenesulfonic acid and a part of methacrylic acid. After neutralization, the temperature was raised again to 101 ° C., and cyclohexane was distilled off using azeotropy with water. While distilling off cyclohexane, 350 parts of water containing 1 part of hydroquinone was sprayed onto the top of the condenser tower. After confirming that the liquid temperature reached 101 ° C, nitrogen was reduced to 18 Nm. ^Three Bubbling was performed at a flow rate of / Hr. The liquid amounts in the chambers (A) and (B) in the separator were kept constant, the distilled solvent was transferred to a solvent storage tank, and the azeotropic distilled water was transferred to a separate tank.
In the reaction vessel, 26450 parts of an aqueous solution of the dehydration reaction product (1) was obtained.
When the concentration of methacrylic acid in the dehydrated solvent of the water separator was examined, it was 3.1%. 112 parts of methacrylic acid are dissolved in the solvent of the water separator.
[0063]
Production Example 2 to Production Example 5 (Production Examples of Dehydration Reaction Products (2) to (5))
By the same method as in Production Example 1, aqueous solutions (2) to (5) of dehydration reaction products were obtained under the synthesis conditions shown in Table 2. After the transfer, the composition of the dehydrating solvent in the water separator was examined. The composition shown in Table 3 was obtained. In addition, the numerical value in the raw material input in Table 2 and the numerical value in Table 3 represent “parts by weight”.
[0064]
[Table 2]

[0065]
[Table 3]

[0066]
Example 1
After the dehydration reaction product (1) was produced by the method shown in Production Example 1, the reaction vessel was washed, and the dehydration reaction product (1) shown in Production Example 1 was produced again. The dehydrated solvent (1) and dehydrated solvent (2) charged in the reaction tank and dissolution tank are cyclohexane in a solvent storage tank partially containing the dehydrated solvent distilled off in the solvent distilling step after the previous Production Example 1. It was used. In addition to cyclohexane, the dehydrating solvent contained 2.0% methacrylic acid, 0.1% methyl methacrylate and the like. As the dehydrating solvent for the water separator, the dehydrated solvent after completion of the solvent distilling step in Production Example 1 was used as it was. In addition to cyclohexane, this dehydrated solvent contained 3.1% methacrylic acid, 0.2% methyl methacrylate, and the like.
The TCAV (total carboxylic acid valence) of the obtained dehydration reaction product (1) was 110.3 mgKOH / g] and moisture = 17.4 [%], which were within the target ranges.
[0067]
Example 2
After the dehydration reaction product (1) was produced by the method shown in Production Example 1, the reaction vessel was washed to produce the dehydration reaction product (3) shown in Production Example 3. The dehydrated solvent (1) and dehydrated solvent (2) charged in the reaction tank and dissolution tank are cyclohexane in a solvent storage tank partially containing the dehydrated solvent distilled off in the solvent distilling step after the previous Production Example 1. It was used. As the dehydrating solvent for the water separator, the dehydrated solvent after completion of the solvent distilling step in Production Example 1 was used as it was. The amount of methacrylic acid charged into the reaction vessel was adjusted in consideration of the previous variety. That is, it calculated as follows.
After implementation of Production Example 1, the amount of methacrylic acid supplied from the water separator to the reaction vessel by circulation of the dehydrated solvent is 112 parts from Table 3. In addition, after synthesizing the dehydration reaction product (3) shown in Production Example 3, the dehydration solvent of the water separator contains 35 parts of methacrylic acid. Considering that the amount of methacrylic acid contained in the dehydrating solvent of the water separator affects the amount of methacrylic acid charged into the reaction vessel, the amount is calculated as 2933 parts when the amount of methacrylic acid charged is reduced by 77 parts. The amount of methacrylic acid contained in cyclohexane in the solvent storage tank is 2.0%. When 1206 parts of dehydrated solvent (1) is charged into the reaction tank, about 24 parts of methacrylic acid are contained. Moreover, about 11 parts of methacrylic acid is contained in 560 parts of dehydration solvent (2) of a dissolution tank. If these amounts are taken into consideration and the amount of methacrylic acid charged into the reaction vessel is adjusted, the quality will be further stabilized. The reaction vessel was charged with 2930 parts of methacrylic acid for esterification.
The TCAV of the obtained dehydration reaction product (3) was measured and found to be 40.7 [mg KOH / g], which was within the target management range of 39.9 to 41.1 [mg KOH / g]. It was.
[0068]
Example 3
After the dehydration reaction product (1) was produced by the method shown in Production Example 1, the reaction vessel was washed to produce the dehydration reaction product (3) shown in Production Example 3. The dehydrated solvent (1) and dehydrated solvent (2) charged in the reaction tank and dissolution tank are cyclohexane in a solvent storage tank partially containing the dehydrated solvent distilled off in the solvent distilling step after the previous Production Example 1. It was used. As the dehydrating solvent for the water separator, the dehydrated solvent after completion of the solvent distilling step in Production Example 1 was used as it was. The amount of methacrylic acid charged into the reaction vessel was 3010 parts without considering the previous variety.
When the TCAV of the obtained dehydration reaction product (3) was measured, it was 42.5 [mg KOH / g], which was outside the target management range of 39.9 to 41.1 [mg KOH / g]. It was. Since the target dehydration reaction product (3) did not fall within the range of TCAV, methacrylic acid and water were further added to adjust the composition and used as the dehydration reaction product (2).
[0069]
Example 4
After Example 3, the amount of methacrylic acid charged was adjusted in consideration of the previous variety. Dehydration reaction products (1) to (4) are converted into (1) → (3) → (2) → (4) → (3) → (2) → (4) → (3) → (1) → ( 2) → Production in order of (3) was all within the target range.
[0070]
Comparative Example 1
In carrying out Production Example 5, cyclohexane charged into the reaction vessel, dissolution vessel, and separator was used in advance by performing the following operation in advance to remove methacrylic acid from the dehydrated solvent. That is, the concentration of methacrylic acid dissolved in the dehydrating solvent is measured, an amount of sodium hydroxide aqueous solution necessary for neutralization is added, stirred for 1 hour, and allowed to stand for 30 minutes. The residual methacrylic acid concentration in the upper layer was confirmed to be 0%. The neutralized water was wastewater. In order to remove methacrylic acid from cyclohexane, in addition to such a cleaning operation, the operation of replacing the solvent in the separator increased, resulting in a decrease in productivity and generation of waste water.
[0071]
Example 5
A glass-lined reaction vessel equipped with a thermometer, stirrer, dripping device, nitrogen inlet tube and cylindrical reflux condenser was charged with 8380 parts of water, and while stirring, the inside of the reaction vessel was replaced with nitrogen gas. The water temperature was heated to 80 ° C. Further, 13300 parts of the dehydration reaction product (3) obtained in Example 2 and an aqueous solution obtained by adding 600 parts of water to 62 parts of mercaptopropionic acid and a static mixer (trade name “T8-15-4PT” manufactured by Noritake Co., Ltd.) The mixture was dropped into the reaction vessel over 4 hours while mixing, and simultaneously with the start of dropping, an aqueous solution in which 125 parts of ammonium persulfate was dissolved in 1000 parts of water as a polymerization initiator was dropped over 5 hours. After completion of the addition of the polymerization initiator, the reaction temperature was continuously maintained at 80 ° C. for 1 hour to complete the polymerization reaction, and 780 parts of 49% aqueous sodium hydroxide solution and 3770 parts of water were added to neutralize to pH 7.2. Thus, an aqueous polymer solution (1) of the present invention having a weight average molecular weight of 33,000 was obtained.
[0072]
【The invention's effect】
Since the method for producing a dehydration reaction product of the present invention has the above-described configuration, the production cost can be efficiently reduced by reusing the dehydration solvent. In addition, the quality is stabilized regardless of the previous type, and several types can be efficiently and stably manufactured using the same reaction apparatus. Can be used in the next dehydration reaction step without refining the dehydrated solvent distilled off in the solvent evaporating step. Replacement of the dehydrated solvent or purification of the dehydrated solvent (separation from acid) Is eliminated, and the dehydration reaction product can be produced efficiently. Such dehydration reaction products include cement additives (cement dispersants), concrete admixtures, calcium carbonate, carbon black, pigment dispersants such as ink, scale inhibitors, gypsum / water slurry dispersants, coal / water. It can be suitably used as a raw material for producing chemical products such as a slurry (CWM) dispersant and a thickener.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram illustrating an apparatus configuration of a dehydration reaction apparatus used in a method for producing a dehydration reaction product of the present invention.

Claims (4)

A dehydration reaction step of esterifying and / or amidating a reaction raw material essentially comprising alcohol and / or amine and (meth) acrylic acid in the presence of a dehydration solvent; and a solvent distillation step of distilling off the dehydration solvent. A method for producing a dehydration reaction product comprising:
Some or all of the dehydrating solvent used in the dehydration reaction step, all SANYO distilling off a solvent distillation step,
The production method of the dehydration reaction product is such that the amount of (meth) acrylic acid charged into the reaction vessel is adjusted by the amount of (meth) acrylic acid in the dehydration solvent distilled off in the solvent evaporating step <br / > A method for producing a dehydration reaction product. The method for producing the dehydration reaction product is such that a dehydration reaction step and a solvent distillation step are repeatedly performed,
The dehydration reaction step is performed using a reaction tank and a water separator that separates the dehydration solvent and water as essential.
The method for producing a dehydration reaction product according to claim 1, wherein the dehydration solvent distilled off in the solvent distillation step in the water separator is used in the next dehydration reaction step. The dehydration reaction product 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. The average addition mole number of the oxyalkylene group by which it represents, and is the number of 0-300.) It is an esterified product of alcohol and (meth) acrylic acid represented by Claim 1 or 2 A method for producing a dehydration reaction product. The method for producing a dehydration reaction product according to claim 1, 2 or 3, wherein the dehydration reaction product is used as a raw material for producing a polymer for a cement additive.

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