JP3685992B2 - Method for preparing reaction solution and reaction solution obtained thereby - Google Patents

Description

【００２８】
で表される単量体を含むことが好ましい。このような単量体がポリアルキレングリコール鎖を有する単量体（Ａ）の主成分として含有されることが好ましい。この場合、ポリアルキレングリコール鎖を有する単量体（Ａ）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。これにより、本発明における反応液をセメント添加剤用重合体等の製造原料として好適に用いることができる。
【００２９】
上記一般式（１）中、Ｒ¹ 及びＲ⁴ は、同一又は異なって、水素原子又は炭素数１〜３０の炭化水素基を表す。Ｒ² は、−ＣＯ−、−ＣＨ₂ −、−（ＣＨ₂ ）₂ −又は−Ｃ（ＣＨ₃ ）₂ −を表す。Ｒ³ Ｏ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。ｍは、Ｒ³ Ｏ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。
【００３０】
上記Ｒ¹ 及びＲ⁴ の炭素数が３０を超えたり、上記Ｒ³ Ｏの炭素数が１８を超えたりすると、本発明における反応液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ｍが３００を超えると、ポリアルキレングリコール鎖を有する単量体（Ａ）を調製しにくくなるおそれがある。
【００３１】
上記Ｒ¹ 及びＲ⁴ やＲ³ Ｏの好適な炭素数の範囲は、本発明における反応液の使用用途により設定されることになる。例えば、セメント分散剤用重合体等の製造原料として用いる場合には、Ｒ¹ としては、水素原子又はメチル基とすることが好ましい。また、Ｒ⁴ 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；ビニル基、アリル基、３−ブテニル基、３−メチル−３−ブテニル基等のアルケニル基；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。
【００３２】
上記Ｒ³ Ｏ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、Ｒ³ Ｏは、一般式（１）で表される単量体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。
【００３３】
上記ｍの範囲についても、本発明における反応液の使用用途により設定されることになり、例えば、セメント添加剤用重合体等の製造原料として用いる場合には、１５〜３００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。
【００３４】
上記ｍが０の場合には、水との溶解性や沸点の点から、上記Ｒ⁴ 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ｍが０の場合には、後述するようにアルコールと（メタ）アクリル酸等の不飽和単量体とを脱水しながらエステル化反応させてポリアルキレングリコール鎖を有する単量体（Ａ）を得るときに、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、目的とするポリアルキレングリコール鎖を有する単量体（Ａ）の収率が低下することから、これを防止するためである。
【００３５】
本発明ではまた、上記カルボキシル基を有する単量体（Ｂ）が、（メタ）アクリル酸であることが好ましい。これにより、本発明における反応液を用いて製造される重合体を各種の化学製品、特にセメント添加剤等に好適に適用することができることになる。
【００３６】
本発明では更に、上記反応液が、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。すなわち本発明における反応液から得られる重合体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、その性能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。
【００３７】
本発明はそして、上記反応液の調製方法により調製されてなる反応液でもある。このような反応液は、高い性能や品質を実現できる重合体を製造することができ、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ることができる重合体の製造原料として好適である。
【００３８】
本発明におけるポリアルキレングリコール鎖を有する単量体（Ａ）とカルボキシル基を有する単量体（Ｂ）とを必須とする混合液の製造方法について、本発明において好適な方法であるアルコキシ（ポリ）アルキレングリコールと過剰量のカルボキシル基を有する単量体（Ｂ）とをエステル化反応させることにより調製する方法を以下に詳述する。
【００３９】
上記エステル化反応による方法としては、例えば、エステル化反応工程に続けて、必要に応じて中和工程、溶剤留去工程等を含んでなる製造方法を好適に適用することができる。
上記エステル化反応工程は、アルコキシ（ポリ）アルキレングリコールと過剰量の（メタ）アクリル酸とを含むエステル化反応用反応液をエステル化反応させる工程であることが好ましい。これにより、一般式（１）で表される単量体と（メタ）アクリル酸とを含む混合液を工業的に簡便に製造することが可能となる。このような工程において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、このようなエステル化反応工程により生成する単量体は、エステル、エステル化物又は脱水反応生成物とも呼ばれる。
【００４０】
上記エステル化反応工程では、エステル化反応が化学平衡となるため、反応によって生成される反応生成水を反応槽から取り除くと反応が進行することになる。このような工程では、（１）反応槽中で生成する反応生成水を取り除きやすくするため、必要によりエステル化反応用反応液に脱水溶剤を混合し、該脱水溶剤と水とを共沸させることにより気化された留出物を生じさせる操作、（２）該留出物が反応槽とコンデンサとを接続する連結管を通過してコンデンサに入り、該コンデンサ中で留出物を凝縮液化させる操作、（３）凝縮液化された留出物をコンデンサに接続された水分離器中で脱水溶剤と水とに分離する操作、（４）分離された脱水溶剤を反応槽中に還流させる操作、等の操作が行われることになる。このような工程では、例えば、反応槽、コンデンサ及び該反応槽と該コンデンサとを接続する連結管を必須とするエステル化反応装置と、該コンデンサと供給管により接続された水分離器とを用いて行われることになる。
【００４１】
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、エステル化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、通常ではエステル化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。
【００４２】
上記コンデンサとは、反応槽から生じる留出物を凝縮液化させる装置であり、該凝縮液化は、冷却液である管外流体と留出物とを熱交換させることにより行われる。なお、留出物とは、エステル化反応工程やその他の工程により反応槽から留出されるものすべてを意味する。すなわち反応槽から留去される生成水や、必要に応じて生成水と共沸させるために用いられる脱水溶剤の他、留出された（メタ）アクリル酸等の反応原料等を含むものを意味し、その形態としては、ガス状、液状等が挙げられる。
【００４３】
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が、好ましくは、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い。
【００４４】
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。
【００４５】
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。
【００４６】
上記エステル化反応に使用されるアルコキシ（ポリ）アルキレングリコールとしては、下記一般式（２）で表される化合物を含有することが好ましい。このような化合物は、アルコキシ（ポリ）アルキレングリ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、アルコキシ（ポリ）アルキレングリ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。
Ｒ⁴ Ｏ（Ｒ³ Ｏ）ｍＨ （２）
一般式（２）中、Ｒ⁴ 、Ｒ³ Ｏ及びｍは、上記と同じである。
【００４７】
上記エステル化反応では、（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。
【００４８】
上記エステル化反応においては、必要に応じて、反応系に触媒を添加して行ってもよく、触媒の存在下で反応を行うことが好ましい。特にエステル化反応では酸触媒が好適であり、反応を速やかに進行させることができる。このような酸触媒としては、水和物及び／又は水溶液の形態で用いてもよく、例えば、硫酸、メタンスルホン酸、パラトルエンスルホン酸、パラトルエンスルホン酸水和物、キシレンスルホン酸、キシレンスルホン酸水和物、ナフタレンスルホン酸、ナフタレンスルホン酸水和物、トリフルオロメタンスルホン酸、「Ｎａｆｉｏｎ（商品名、デュポン社製）」レジン、「Ａｍｂｅｒｌｙｓｔ １５（商品名）」レジン、リンタングステン酸、リンタングステン酸水和物、塩酸等が挙げられる。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。
【００４９】
上記酸触媒の中でも、後述する脱水溶剤と水との共沸温度や反応温度等の点から、常圧（１０１３ｈＰａ）における沸点が高いもの、具体的には、常圧における沸点が１５０℃以上であるものが好ましい。より好ましくは、２００℃以上である。このような酸触媒としては、例えば、硫酸（常圧における沸点：３１７℃）、パラトルエンスルホン酸（沸点：１８５〜１８７℃／１３．３Ｐａ（０．１ｍｍＨｇ））、パラトルエンスルホン酸水和物、メタンスルホン酸（沸点：１６７℃／１３３３．２Ｐａ（１０ｍｍＨｇ））等が挙げられる。これらの中でも、パラトルエンスルホン酸、パラトルエンスルホン酸水和物を用いることが好適である。
【００５０】
上記酸触媒の使用量としては、所望の触媒作用を有効に発現することができる範囲であれば特に限定されず、例えば、０．４ミリ当量／ｇ以下とすることが好ましい。０．４ミリ当量／ｇを超えると、エステル化反応時に反応系内で形成されるジエステルの量が増加し、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、０．３６〜０．０１ミリ当量／ｇであり、更に好ましくは、０．３２〜０．０５ミリ当量／ｇである。なお、酸触媒の使用量（ミリ当量／ｇ）とは、反応に使用した酸触媒のＨ⁺ の当量数（ミリ当量）を、反応原料の合計仕込み量（ｇ）で割った値で表され、具体的には、下記式により算出される値を意味する。
【００５１】
【数１】

【００５２】
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。
【００５３】
上記エステル化反応は、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、反応原料中のカルボキシル基を有する単量体（Ｂ）とその生成物であるポリアルキレングリコール鎖を有する単量体（Ａ）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、エステル化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。
【００５４】
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、本発明における反応液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。
【００５５】
上記エステル化反応操作としては、脱水溶剤がなくても行なえるが、脱水溶剤を用いて行うことにより、例えば、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好ましい。これにより、エステル化反応で生成する反応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。
【００５６】
上記脱水溶剤を用いるエステル化反応操作において、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。
【００５７】
上記エステル化反応工程において、エステル化反応は、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、本発明における反応液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、本発明における反応液の性能及び品質の劣化等が生じるおそれがある。
【００５８】
上記反応条件において、反応時間としては、後述するようにエステル化の反応率（いわゆるエステル化率）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。
【００５９】
上記エステル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。
【００６０】
【数２】

【００６１】
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
【００６２】
上記エステル化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、エステル化反応により得られるポリアルキレングリコール鎖を有する単量体（Ａ）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。また、脱水溶剤を用いた場合には、該脱水溶剤を取り除くため、脱水溶剤を留去する溶剤留去工程を行うことが好ましい。
【００６３】
上記中和工程の方法としては、例えば、エステル化反応の終了後、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。
【００６４】
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。
【００６５】
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、ポリアルキレングリコール鎖を有する単量体（Ａ）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。
【００６６】
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、ゲル化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、ゲル化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、エステル化反応用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。
【００６７】
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。
【００６８】
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、エステル化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。
【００６９】
以下では、本発明における反応液を製造原料とするセメント分散剤用重合体の製造方法や、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。
【００７０】
上記セメント分散剤用重合体としては、ポリアルキレングリコール鎖を有する単量体（Ａ）とカルボキシル基を有する単量体（Ｂ）を必須成分とする単量体成分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。
【００７１】
上記ポリカルボン酸系重合体を製造する場合に用いるポリアルキレングリコール鎖を有する単量体（Ａ）としては、例えば、メトキシ（ポリ）エチレングリコールモノ（メタ）アクリレート、メトキシ（ポリ）プロピレングリコールモノ（メタ）アクリレート、メトキシ（ポリ）ブチレングリコールモノ（メタ）アクリレート、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モノ（メタ）アクリレート、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モノ（メタ）アクリレート、メトキシ（ポリ）プロピレングリコール（ポリ）ブチレングリコールモノ（メタ）アクリレート、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モノ（メタ）アクリレート、エトキシ（ポリ）エチレングリコールモノ（メタ）アクリレート、エトキシ（ポリ）プロピレングリコールモノ（メタ）アクリレート、エトキシ（ポリ）ブチレングリコールモノ（メタ）アクリレート、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モノ（メタ）アクリレート、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モノ（メタ）アクリレート、エトキシ（ポリ）プロピレングリコール（ポリ）ブチレングリコールモノ（メタ）アクリレート、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モノ（メタ）アクリレート等のポリアルキレングリコールモノ（メタ）アクリレート類、アリルアルコール、メタリルアルコール、３−ブテン−１−オール、３−メチル−３−ブテン−１−オール、３−メチル−２−ブテン−１−オール、２−メチル−３−ブテン−２−オール等のアルコールへのアルキレンオキシド付加物；アリルアミン等アミノ基含有単量体へのアルキレンオキシド付加物；ポリアルキレングリコールモノエーテルとアリルアルコール等とのエーテル化物等が挙げられる。また、カルボキシル基を有する単量体（Ｂ）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。
【００７２】
ポリカルボン酸系重合体には、必要に応じてポリアルキレングリコール鎖を有する単量体（Ａ）とカルボキシル基を有する単量体（Ｂ）以外の単量体を共重合させることもできる。すなわち本発明における反応液には、ポリアルキレングリコール鎖を有する単量体（Ａ）とカルボキシル基を有する単量体（Ｂ）以外の単量体を含有させることができる。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等が挙げられる。
【００７３】
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。
【００７４】
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。
【００７５】
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℃
【００７６】
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。
【００７７】
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。
【００７８】
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。
【００７９】
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。
【００８０】
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、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。
【００８１】
【発明の実施の形態】
本発明の反応液の調製方法について、混合液から高分子凝集物の一部又は全部を除去する方法、及び、成分調整の方法の一実施形態を説明する。なお、これらの実施形態は本発明をより具体的に説明するための例示であり、本発明の実施形態はこれらに限られるものではない。
【００８２】
先ず、混合液から高分子凝集物の一部又は全部を除去する方法として、ろ過方法が好適であることから、この方法について、図１及び図２を用いて説明する。
図１は、部分ろ過方法を行うための装置構成を示す概念図である。図１では、容器、ストレーナー及びポンプが設けられ、それぞれが配管により循環するように接続されている。この場合、混合液が容器に入れられ、容器中の混合液が循環するように設定されている。このような装置構成では、容器中の混合液の一部をろ過手段であるストレーナーを通過させて循環させることにより、部分ろ過を行うことができる。このとき、容器中の混合液を攪拌機等により攪拌すると、効率的に部分ろ過を行うことができる。
【００８３】
図２は、全ろ過方法を行うための装置構成を示す概念図である。図２では、容器、ストレーナー、ポンプ及び別の容器が設けられ、それぞれが配管により接続されている。この場合、混合液が容器１に入れられ、容器１中の混合液が別の容器２に移るように設定されている。このような装置構成では、容器１中の混合液の全部をろ過手段であるストレーナーを通過させて別の容器２に移すことにより、全ろ過を行うことができる。このときにも、容器１中の混合液を攪拌機等により攪拌すると、効率的に全ろ過を行うことができる。
【００８４】
上記ろ過方法では、いずれも混合液のろ過を行うにあたって、別の容器で調製され、必要により保存及び／又は移送した混合液を上記容器に入れることにより行ってもよく、混合液を得るために用いた反応槽を上記容器として行ってもよい。また、上記容器を重合反応を行う反応槽としてもよい。
【００８５】
上記ろ過方法において、ろ過を行う条件として、例えば、ろ過時間としては、作業効率や、反応液を用いて製造される重合体の性能や品質等を考慮して適宜設定すればよく特に限定されるものではない。また、ろ過温度としては、通常では常温で行えばよい。
【００８６】
次に、上記成分調整の方法として、本発明において混合液の調製方法として好適な方法である、アルコキシ（ポリ）アルキレングリコールと過剰量のカルボキシル基を有する単量体（Ｂ）とをエステル化反応させることにより調製する方法を行う場合について、下記エステル化反応の反応式を用いて説明する。
【００８７】
【化３】

【００８８】
式中、ＰＧは、アルコキシ（ポリ）アルキレングリコールを表し、ＭＡは、メタクリル酸を表し、ＰＭは、ポリアルキレングリコール鎖を有する単量体（Ａ）を表し、ＳＡは、酸触媒である硫酸を表し、ＣＨは、脱水溶剤であるシクロヘキサンを表す。また、１１５℃は、この反応式のエステル化を該温度で行うことを表す。
【００８９】
上記反応式における物質収支を計算した結果を表１に示す。この表において、Ｘは、ＰＧのモル数を表し、（Ｘ＋Ｙ）は、ＭＡのモル数を表し、Ｙは、Ｘに対して過剰量のＭＡのモル数を表し、ｅは、全てのＰＧがエステル化した場合を１とするエステル化の割合を表し、ｅ×１００の値がエステル化率（％）となる。ｅＸは、生成するＰＭと水のモル数を表し、Ｙ＋（１−ｅ）Ｘは、未反応として残るＭＡのモル数を表し、（１−ｅ）Ｘは、未反応として残るＰＧのモル数を表す。分子量とグラム数（ｇ）も同様に上記反応式における物質に対応して表したものである。また、ＳＡのモル数は、反応原料であるＰＧとＭＡの合計重量に対して２重量％と設定すると、下記式（１）により計算され、ＣＨの重量は、反応原料であるＰＧとＭＡの合計重量に対して５重量％と設定すると、下記式（２）により計算され、ＰＴＺの重量は、反応原料であるＰＧとＭＡの合計重量に対して２５０ｐｐｍと設定すると、下記式（３）により計算される。
０．０２×｛１１３２Ｘ＋８６（Ｘ＋Ｙ）｝ （１）
０．０５×｛１１３２Ｘ＋８６（Ｘ＋Ｙ）｝ （２）
２５０×１０^-6×｛１１３２Ｘ＋８６（Ｘ＋Ｙ）｝ （３）
【００９０】
【表１】

【００９１】
上記反応式で表されるエステル化反応に続けて、中和工程及び溶剤留去工程を行った場合の物質収支を計算した結果を表２に示す。この表２では、エステル化率を９８．０％とし、中和工程で中和剤として水酸化ナトリウムを用いた場合について計算している。
【００９２】
【表２】

【００９３】
表２中、反応前の列には、各反応原料を反応系に供給するときの供給量として、グラム数（ｇ）とモル数とが示されている。ＰＧ、ＭＡ、ＳＡ、ＰＴＺ及びＣＨの供給量は、エステル化反応工程を行うときの量であり、水の供給量は、中和工程を行うときの量である。反応後の列には、溶剤留去工程後の反応系の組成として、グラム数（ｇ）とモル数と表２に示す反応後の全量を１００重量％としたときの重量割合（重量％）とが示されている。反応後の単量体（ＰＧ、ＭＡ及びＳＭＡ）の合計重量割合は７５．３％である。なお、ＳＭＡは、ＭＡＡが中和されることにより生じたメタクリル酸ナトリウムを表し、ＳＳＡは、ＳＡが中和されることにより生じた硫酸ナトリウムを表す。なお、エステル化反応により生成する反応生成水や中和剤として使用する水酸化ナトリウムについては考慮しないものとする。
【００９４】
ここで、
目標組成物中の水分量は、
０．１＋０．３＋２０．９＝２１．３％
目標組成物中のＴＣＡＶは、
（２５３．７＋１３．４）×５６１１０／１８７２３４
＝８０．０ｍｇ−ＫＯＨ／ｇ
と、計算される。
表２に示されるように、上記反応式の物質収支を計算すると、下記のようになる。
（１）エステル化率：９８．０％
（２）ＴＣＡＶ：８０．０ｍｇ−ＫＯＨ／ｇ
（３）水分：２１．３重量％
【００９５】
実際には、ＭＡや水がシクロヘキサンと共に留去され、また、高分子凝集物（Ｃ）が形成されてこの一部又は全部を除去する工程を行うときには、表２の反応後の列に示されるような組成とはならないことになる。従って、管理値として、例えば、上記反応式の場合では下記のように設定して成分を調整することにより、得られる重合体の性能と品質を安定的に保つことができる反応液を調製することが可能となる。この場合、ＴＣＡＶの値を管理することを必須とすることが好ましい。より好ましくは、エステル化率や水分の値を管理することを組み合わせて行うことである。
【００９６】
管理値
（１）エステル化率：９８．０±０．５％
（２）ＴＣＡＶ：８０．０±２．０ｍｇ−ＫＯＨ／ｇ
（３）水分：２１．３±０．５重量％
【００９７】
表２に示される反応後の各物質の量を実際に知るためには、例えば、ＰＭ及びＰＧについては、（高速）液体クロマトグラフィーにより両者の比率を測定して各々の含有量を計算する方法を用い、また、その比率からエステル化率を計算することができる。ＭＡ及びＳＭＡについては、反応液の一部を試料として滴定することによりＴＣＡＶとして求めることができる。更に、ＳＡ、ＳＳＡ及びＰＴＺについては、反応系内に供給した量から求めることができ、水については、カールフィッシャー法による水分量測定方法を用いて求めることができる。このように反応後の各物質の量を測定した後に、管理値の範囲内となるように成分調整が行われることになる。
【００９８】
【表３】

【００９９】
表３は、ＴＣＡＶと水分の値を管理する場合について、成分を調整する前と調整した後の全体量、ＴＣＡＶ及び水分の測定値を例示している。この場合、上記管理値を目標として成分調整され、ＭＡやＨ₂ Ｏのグラム数（ｇ）が調整されることになる。ＭＡやＨ₂ Ｏのグラム数（ｇ）を増加させる場合には、正の数として示され、減少させる場合には、負の数として示されている。このとき、ＭＡやＨ₂ Ｏを添加するだけでは調整できない場合は、一旦加熱してＭＡやＨ₂ Ｏの一部を除去した後に添加することで調整することができる。加熱する際には、（１）攪拌したり、（２）減圧したり、（３）窒素ガス等の不活性ガスを液中にバブリングしたりする等の操作を適宜組み合わせて行うことが好ましい。攪拌したり不活性ガスを液中にバブリングしたりすると、ＭＡやＨ₂ Ｏが留去されやすくなり、これらの除去が促進されることになり、減圧すると、低温で揮発しやすくなると共に、短時間で留去されやすくなる。このように管理値を目標として成分調整することにより、反応液を重合体の性能と品質をより確実に安定的に保つことができる製造原料とすることができることになる。
【０１００】
【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。
【０１０１】
製造例１
温度計、圧力計及び撹拌機を備えたオートクレーブに、フレーク状水酸化ナトリウム４部を仕込み、窒素加圧と排気を繰り返すことによって充分に窒素置換を行った。次にメタノール５７５部を仕込み、この混合液の温度を９０℃まで昇温した。初期圧力を０．１５ＭＰａに設定し、エチレンオキシド７９００部を８時間かけて添加した。この間の反応温度は１２５±５℃、反応圧力は０．７８ＭＰａ以下に維持した。更に２時間、反応温度を維持して、エチレンオキシドのメタノールへの付加反応を完結させ、メタノール１モルに対してエチレンオキシド１０モルが付加したメトキシポリ（ｎ＝１０）エチレングリコール［ＣＨ₃ Ｏ（ＣＨ₂ ＣＨ₂ Ｏ）₁₀Ｈ］を得た。このようにして得られたアルコキシポリアルキレングリコール（１）の付加反応直後の過酸化物価を以下のようにして測定したところ０．０ミリ当量／ｇであった。
【０１０２】
過酸化物価の測定方法
アルコキシポリアルキレングリコール１０ｇを活栓付き三角フラスコに精秤し、溶媒５０ｍｌ（イソプロピルアルコール５００ｍｌ、水１００ｍｌ及び酢酸１５０ｍｌの混合液）を入れて、試料を溶解した。試料が溶解したら、フラスコ内を窒素ガスで置換しながら、飽和ヨウ化カリウム１ｍｌを加えて１分間攪拌し、３０分間暗所で放置して、黄色透明の試験溶液を調製した。次に、この試験溶液に、０．０１Ｎのチオ硫酸ナトリウムを、上記試験溶液の褐色が消えるまで滴下し、この際のチオ硫酸ナトリウムの滴定量（ｍｌ）を測定し、下記式に従って、過酸化物価を算出した。なお、ブランク値（ｍｌ）は、試験溶液の代わりに、アルコキシポリアルキレングリコールを添加しない試験溶液を用いた以外は上記と同様の操作をすることによって得た。
【０１０３】
【数３】

【０１０４】
製造例２
温度計、圧力計及び撹拌機を備えたオートクレーブに、アルコキシポリアルキレングリコール（１）を７５１部仕込み、窒素加圧と排気を繰り返すことによって充分に窒素置換を行った。温度を１５３℃に設定した後、圧力を０．１５ＭＰａに設定し、エチレンオキシド１０５０部を６時間かけて添加した。この間の反応温度は１５３±５℃、反応圧力は０．７８ＭＰａ以下に維持した。更に１時間、反応温度を維持して、エチレンオキシドのメタノールへの付加反応を完結させ、メタノール１モルに対してエチレンオキシド２５モルが付加したメトキシポリ（ｎ＝２５）エチレングリコール［ＣＨ₃ Ｏ（ＣＨ₂ ＣＨ₂ Ｏ）₂₅Ｈ］を得た。このようにして得られたアルコキシポリアルキレングリコール（２）の付加反応直後の過酸化物価を測定したところ０．０ミリ当量／ｇであった。
【０１０５】
保存
アルコキシポリアルキレングリコール（２）を酸素濃度０．５〜１．０容積％に管理したガス（ＡＩＧガス）でシールしたタンク内に温度５０〜６０℃で、３ケ月間保存した。このとき通常過酸化物価が１．０ミリ当量／ｇ以下でならなければならないアルコキシポリアルキレングリコールの過酸化物価は、２．４ミリ当量／ｇまで上昇した。
【０１０６】
実施例１
エステル化
温度計、攪拌機、生成水分離器及び還流冷却管を備えたガラス製反応容器に、アルコキシポリアルキレングリコール（過酸化物価：２．４ミリ当量／ｇ）１１３２０部、メタクリル酸３３２０部、脱水溶剤としてのシクロヘキサン７３０部、酸触媒としてのパラトルエンスルホン酸一水和物２９３部及び重合禁止剤としてのフェノチアジン３．７部を仕込み、混合溶液を攪拌しながら温度を１０７℃にまで昇温してエステル化反応を開始した。２０時間後、エステル化率が９８％になったことを確認して６０℃以下まで冷却し、４．２％水酸化ナトリウム水溶液１７４０部及び水１９２３部を加えた。次に、再び昇温してシクロヘキサンを水との共沸によって追い出し、単量体混合物（Ｍ１）を得た。単量体混合物（Ｍ１）には、ゲル状高分子（高分子凝集物）が含まれていた。
【０１０７】
ろ過
単量体混合物（Ｍ１）をポンプで別の容器に移送した。ポンプの手前にはバケット型のストレーナー（６０メッシュ、管径４インチ）を付け、単量体（Ｍ１）中のゲル状高分子をろ過した。ろ過されたゲル状高分子は３２０部であった。ろ過により、ろ液（Ｍ２）を得た。
【０１０８】
分析と調整
得られたろ液（Ｍ２）は１８２５０部、ＴＣＡＶは８２．０ｍｇ−ＫＯＨ／ｇ、水分は１９．２％、エステル化率は９８．０％であった。目標のＴＣＡＶは、８７．０±１．５ｍｇ−ＫＯＨ／ｇ、水分は１９．５±０．５％、エステル化率は９８％以上であったので、ろ液（Ｍ２）にメタクリル酸１７８．５部、水１１１．３部を添加して、単量体混合物（Ｍ３）を得た。ゲル状高分子が除去された単量体混合物（Ｍ３）は、ＴＣＡＶは８７．０ｍｇ−ＫＯＨ／ｇ、水分は１９．０％、エステル化率９８．０％であった。この結果を表４に示した。
【０１０９】
【表４】

【０１１０】
重合
次に、温度計、攪拌機、滴下ロート、窒素導入管及び還流冷却管を備えたガラス製反応容器に、水８２２０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、上記で得られた単量体混合物（Ｍ３）１３２５０部にメルカプトプロピオン酸１００部を加えた溶液を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、反応溶液を５０％水酸化ナトリウム水溶液でｐＨ７まで中和して、重量平均分子量（ゲルパーミエーションクロマトグラフィー（ＧＰＣ）によるポリエチレングリコール換算：以下、同様とする）２００００の重合体水溶液（Ｐ１）を得た。
重合体水溶液（Ｐ１）のＧＰＣチャートに高分子量のピークはなかった。また、重合体水溶液（Ｐ１）を透明なガラスビン（２００ｍｌ）に採って目視で外観を確認したがゲルはなく、移送ポンプのストレーナーにもゲルは蓄積しなかった。
【０１１１】
比較例１
単量体混合物（Ｍ３）の代わりに、単量体混合物（Ｍ１）を重合に用いた以外は、実施例１と同様にして重合を行った。すなわち、ろ過はせずに分析と調整を行った後に重合を行った。単量体混合液（Ｍ１）中のゲル状高分子がポンプの閉塞を招き、一定速度で単量体溶液の滴下ができなかった。また得られた重合体（Ｇ１）には目視でゲルが観察された。ゲルはセメント組成物中で凝集剤として働き、セメント分散性能に悪影響を及ぼすことから、ゲルを含んだ重合体（Ｇ１）は、廃棄した。
【０１１２】
【発明の効果】
本発明の反応液の調製方法は、上述の構成よりなるので、高い性能や品質を実現する重合体を製造することができ、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ることとなる。また、本発明反応液から製造される重合体は、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】本発明における部分ろ過方法を行うための装置構成を示す概念図である。
【図２】本発明における全ろ過方法を行うための装置構成を示す概念図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for preparing a reaction solution containing a monomer having a polyalkylene glycol chain and a monomer having a carboxyl group as essential components, a reaction solution obtained thereby, and a method for producing a cement additive.
[0002]
[Prior art]
A reaction liquid containing a monomer having a polyalkylene glycol chain and a monomer having a carboxyl group is useful as a raw material for producing various polymers. 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]
As a method for preparing such a reaction solution, in addition to a method of mixing these monomers, a method of adjusting an esterification reaction between an alkoxy (poly) alkylene glycol and an excess amount of (meth) acrylic acid can be mentioned. It is done. The latter method is an industrially preferable method because a monomer having a polyalkylene glycol chain can be prepared and a reaction solution to be subjected to a polymerization reaction can be prepared at a time. A polymer is produced by carrying out the polymerization step using the reaction solution thus prepared as a production raw material.
[0004]
However, in a reaction solution containing a monomer produced due to a process abnormality or a reaction solution that has been prepared and stored or transported over time, polymer aggregates are formed. When a polymer is produced by using the polymer, polymer aggregates are contained as impurities in the polymer solution. Such impurities can cause problems in the manufacturing process and reduce the performance and quality of chemical products, so they cannot be used as raw materials for polymer production and are disposed of as waste. It will be.
[0005]
By the way, by adding a polymerization initiator or the like to a reaction solution containing a monomer having a polyalkylene glycol chain and a monomer having a carboxyl group, it is subjected to polymerization to obtain a polymer and various cement additives and the like. There is no effective method that can appropriately and easily manage the performance and quality of cement additives when used in chemical products, especially when polymer aggregates are contained in chemical products. , Research to be able to prepare a reaction liquid for producing a polymer that is difficult to regenerate as a raw material for polymer production while maintaining constant performance and quality, and that requires high performance and quality There was room.
[0006]
For example, a cement additive has the effect of improving the fluidity of the cement composition and improving the strength and durability of the cured product, but it can contain impurities and keep the quality stable. If it is not possible, the performance and quality will be reduced, and the strength and durability of the cured products such as civil engineering and building structures will decrease, which may lead to a decrease in safety and an increase in repair costs. There is a problem because high quality is required.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described situation, and is a method for preparing a reaction solution that essentially includes a monomer having a polyalkylene glycol chain and a monomer having a carboxyl group, and has high performance and quality. A method for preparing a reaction solution and a reaction obtained thereby can sufficiently suppress the occurrence of defects in the production process and the deterioration of the performance and quality of various chemical products. The object is to provide a liquid.
[0008]
[Means for Solving the Problems]
The present invention prepares a reaction liquid to be subjected to a polymerization reaction from a mixed liquid containing a monomer (A) having a polyalkylene glycol chain, a monomer (B) having a carboxyl group, and a polymer aggregate (C). A method of removing a part or all of the polymer aggregate (C) from the mixed solution and a step of adjusting the components by measuring the total amount of the reaction solution. This is a method for preparing a reaction solution.
[0009]
The present invention is also a method for preparing a reaction solution to be subjected to a polymerization reaction from a mixed solution containing a monomer (A) having a polyalkylene glycol chain and a monomer (B) having a carboxyl group, It is also a method for preparing a reaction liquid comprising essentially a step of adjusting the components by measuring the content of the monomer (B) having a carboxyl group in the reaction liquid.
[0010]
The present invention further relates to a method for preparing a reaction solution to be subjected to a polymerization reaction from a mixed solution containing a monomer (A) having a polyalkylene glycol chain and a monomer (B) having a carboxyl group, When the polymer aggregate (C) is present in the mixed solution, the method includes a step of removing a part or all of the polymer aggregate (C) from the mixed solution, and the total amount of the reaction solution It is also a method for preparing a reaction solution that essentially comprises a step of adjusting the components by measuring the content of the monomer (B) having a carboxyl group in the reaction solution.
The present invention is also a reaction solution prepared by the method for preparing a reaction solution.
[0011]
As a result of diligent research to prepare a reaction liquid that can be used as a raw material for producing a polymer that achieves high performance and quality, the present inventors have obtained mixed liquids containing monomers produced due to process abnormalities, In a mixed solution that has been stored or transferred after preparation and has passed through time, polymer aggregate (C) may be present, and in particular, the amount of polymer aggregate (C) increases with time. First, I focused on the increase. Such a mixed solution cannot be used as a raw material for producing a polymer as it is, but can be obtained by removing the polymer aggregate (C) and adjusting the total amount of the reaction solution and specific components. It has been found that the polymer is suitable as a production raw material capable of stably maintaining the performance and quality of the polymer. Specifically, (1) removing a part or all of the polymer aggregate (C), (2) measuring the total amount of the reaction solution, or a monomer having a carboxyl group in the reaction solution ( The inventors have arrived at the present invention by conceiving that the above problems can be solved by adjusting the components by measuring the content of B). Moreover, it discovered that the reaction liquid obtained by such a preparation method can be used suitably as manufacturing raw materials, such as a polymer for cement additives.
The present invention is described in detail below.
[0012]
The method for preparing a reaction solution of the present invention is a polymerization reaction from a mixed solution containing a monomer (A) having a polyalkylene glycol chain, a monomer (B) having a carboxyl group, and a polymer aggregate (C). This is a method for preparing a reaction solution to be attached.
In the method for preparing a reaction liquid of the present invention, the mixed liquid means a solution in which a monomer (A) having a polyalkylene glycol chain and a monomer (B) having a carboxyl group are mixed as an essential blend. In addition, it is preferable that the main component is a monomer (A) having a polyalkylene glycol chain and a monomer (B) having a carboxyl group. As a mixed liquid containing the monomer (A) having a polyalkylene glycol chain, the monomer (B) having a carboxyl group, and the polymer aggregate (C), for example, when preparing the mixed liquid, Those in which polymer aggregates (C) are formed due to abnormalities, or those in which polymer aggregates (C) are formed over time after being stored or transported after preparing a mixture, etc. Can be mentioned. Further, the reaction liquid means a solution for subjecting the monomer (A) having a polyalkylene glycol chain and the monomer (B) having a carboxyl group as essential blends to a polymerization reaction, Also called monomer mixture. The mixed solution or reaction solution may or may not contain components other than the essential components.
[0013]
Examples of a method for preparing a mixed liquid essentially comprising the monomer (A) having a polyalkylene glycol chain and the monomer (B) having a carboxyl group include (1) these monomers. A method of preparing by mixing; (2) a method of preparing by esterifying an alkoxy (poly) alkylene glycol and an excess amount of a monomer (B) having a carboxyl group; , (2) is suitably applied to the mixed solution obtained.
[0014]
In this invention, the process of removing one part or all part of the said polymer aggregate (C) from the said liquid mixture is included. As a result, the performance and quality of the chemical product produced by the polymer obtained using the reaction solution as a production raw material will be improved. As a result, it becomes possible to regenerate a liquid mixture that could not be used in the prior art to obtain a reaction liquid for producing a polymer. Process abnormalities are abnormalities in the manufacturing process that occur when, for example, new equipment is used or when manufacturing raw materials are changed, bumping, contamination, etc., or equipment such as pumps is abnormal, In such a case, polymer aggregate (C) may be formed. The polymer aggregate (C) is a monomer (A) having a polyalkylene glycol chain and / or a monomer (B) having a carboxyl group, other monomers present in a mixed liquid, etc. Means a polymer formed by polymerization and is called a so-called gel, gel-like material, gel-like polymer or the like.
[0015]
The method for confirming the polymer aggregate (C) in the mixed liquid is not particularly limited. For example, the method of visually observing the mixed liquid; the polymer aggregate (C ); A method of examining the peak of a high molecular weight substance considered to be a precursor of the polymer aggregate (C) by GPC, or the like.
[0016]
Examples of the method for removing a part or all of the polymer aggregate (C) from the mixed solution include, for example, a partial filtration method by filtering a part of the mixed solution, and a whole method by filtering the whole mixed solution. A filtration method is industrially suitable. In such a filtration method, for example, a strainer for protecting the pump, a pole filter, a wire mesh, or the like is used.
[0017]
In the present invention, the components are adjusted by measuring the total amount of the reaction solution. If the total amount of the reaction solution can be known, the components of the reaction solution can be adjusted accurately. In the polymer produced from such a reaction liquid, the quality is sufficiently controlled, and the performance and quality in various chemical products such as cement additives produced by the polymer are improved. . The total amount of the reaction solution means the total weight remaining after removing a part or all of the polymer aggregate (C) from the mixed solution. As a method for measuring the total weight of the reaction solution, for example, (1) the total amount of the reaction solution inside is directly measured by measuring the weight together with a pre-weighed reaction tank, or (2) Calculate from the flow rate and time when transported to another container, or (3) calculate the results of the material balance before and after the reaction by measuring it with various detectors such as a liquid level meter and flow meter. The total weight of the liquid can be measured. In the present invention, the method (1) is preferable when the scale is relatively small, and the method (2) or (3) is preferable when the scale cannot be directly measured. It is mentioned as a preferable form.
[0018]
A method for preparing a reaction solution to be subjected to a polymerization reaction from a mixed solution comprising a monomer (A) having a polyalkylene glycol chain and a monomer (B) having a carboxyl group, wherein the carboxyl in the reaction solution In the method for preparing a reaction solution which essentially includes a step of adjusting the components by measuring the content of the monomer (B) having a group, the monomer (B) having a carboxyl group in the reaction solution Since the content can be known, for example, when preparing a mixed solution by esterifying an alkoxy (poly) alkylene glycol and an excess amount of (meth) acrylic acid, excess or unreacted (meth) The components of the reaction solution are adjusted in consideration of the monomer (B) having a carboxyl group generated by hydrolysis of acrylic acid or the monomer (A) having a polyalkylene glycol chain. Possible and becomes, performance and quality of the polymers obtained from the reaction solution is improved. Such a method for preparing a reaction solution is also one aspect of the present invention.
[0019]
Examples of the method for measuring the content of the monomer (B) having a carboxyl group in the reaction solution include a method by titration, a method by (high-speed) liquid chromatography, and the like. Among these, in the former method, the content of the monomer (B) having a carboxyl group in the reaction solution can be directly measured by titrating a part of the reaction solution as a sample. Although the measurement accuracy is accurate, it can be applied when only one monomer is contained as the monomer (B) having a carboxyl group. Moreover, in the latter method, when measuring a part of the reaction solution as a sample, the measurement accuracy is reduced by a dilution operation, but when two or more kinds of monomers (B) having a carboxyl group are contained It is also possible to apply to. The content of the carboxyl group-containing monomer (B) is preferably measured as a total carboxylic acid amount (converted to KOH mg) in 1 g of the reaction solution, so-called TCAV (Total Carboxylic AcidValue). Thereby, it becomes possible to manage appropriately and simply performance and quality, such as a cement additive.
[0020]
A method for preparing a reaction solution to be subjected to a polymerization reaction from a mixed solution containing a monomer (A) having a polyalkylene glycol chain and a monomer (B) having a carboxyl group, In the case where the molecular aggregate (C) is present, it comprises a step of removing a part or all of the polymer aggregate (C) from the mixed liquid, and the total amount of the reaction liquid and the reaction liquid In the method for preparing a reaction solution which essentially includes the step of adjusting the components by measuring the content of the monomer (B) having a carboxyl group, the mixture in which the polymer aggregate (C) is formed It becomes possible to make a reaction solution for producing a polymer by regenerating the solution, and knowing the total amount of the reaction solution and the content of the monomer (B) having a carboxyl group in the reaction solution Therefore, the components of the reaction solution can be adjusted more appropriately. Becomes possible, the performance and quality of the polymers obtained from the reaction solution thereof can be further enhanced. Such a method for preparing a reaction solution is also one aspect of the present invention.
[0021]
In addition to the above component adjustment, it is possible to measure the content of the monomer (A) having a polyalkylene glycol chain in the reaction solution, measure the water content in the reaction solution, etc. It is preferable to carry out a combination of these. Further, as a method for preparing a mixed solution, when preparing a mixed solution by esterifying an alkoxy (poly) alkylene glycol and a monomer (B) having an excessive amount of carboxyl groups, a polyalkylene glycol chain is used. It is preferable to measure the content of the alkoxy (poly) alkylene glycol remaining in the reaction solution as unreacted or produced as a hydrolyzate while measuring the content of the monomer (A) it has. By measuring these contents, it becomes possible to adjust the components of the reaction solution more accurately.
[0022]
Examples of a method for measuring the content of the monomer (A) having a polyalkylene glycol chain in the reaction solution and a method for measuring the content of the alkoxy (poly) alkylene glycol in the reaction solution include ( Examples include a method in which the ratio between the two is measured by high-speed liquid chromatography and the respective contents are calculated, a method in which a calibration curve is created by liquid chromatography and the absolute amount is calculated. Among these, in the former method, if the ratio of the monomer (A) having a polyalkylene glycol chain and the alkoxy (poly) alkylene glycol is known, the absolute amount of both from the charged amount of the alkoxy (poly) alkylene glycol. Therefore, the ratio between the two is measured by (high-speed) liquid chromatography. At this time, when a part of the reaction solution is injected as a sample into (high-speed) liquid chromatography, a dilution operation is involved. However, since it is a ratio measurement, it is accurate because it is not affected by the dilution amount. Then, as the monomer (A) having a polyalkylene glycol chain, for example, an ester standard product may be difficult to obtain, so the former method is preferable.
[0023]
Examples of the method for measuring the water content in the reaction solution include a water content measurement method by the Karl Fischer method.
In the present invention, when the reaction solution is subjected to the polymerization reaction, in addition to performing the above measurement, for example, components such as a catalyst and a polymerization inhibitor are adjusted. The content can be calculated from the charged amount when attaching.
[0024]
In the present invention, component adjustment is performed after the measurement as described above. For example, the components can be adjusted by adjusting the composition of the reaction solution. That is, by adjusting the content of the monomer (A) having a polyalkylene glycol chain, the content of the monomer (B) having a carboxyl group, the water content, the content of a catalyst, a polymerization inhibitor, etc. The composition can be controlled. Moreover, when preparing a liquid mixture by esterifying the alkoxy (poly) alkylene glycol and the monomer (B) having an excessive amount of carboxyl groups, the components are adjusted by adjusting the esterification rate. be able to.
[0025]
In the above component adjustment, the method of adjusting the composition of the reaction solution can be performed, for example, by adding the above-mentioned compound to the reaction solution or by removing it by distillation. Moreover, as a method of adjusting esterification rate, content of the monomer (A) which has alkoxy (poly) alkylene glycol and a polyalkylene glycol chain | strand, content of the monomer (B) which has a carboxyl group, for example Etc. can be measured and reaction conditions etc. can be adjusted. In this case, the esterification rate is confirmed by measuring the above content. In the present invention, it is preferable to adjust TCAV and water as the content of the monomer (B) having a carboxyl group after measuring the esterification rate. Thereby, the reaction liquid in this invention can maintain the performance and quality of a polymer more reliably as a manufacturing raw material of a polymer more reliably.
[0026]
In the present invention, the monomer (A) having the polyalkylene glycol chain is represented by the following general formula (1);
[0027]
[Chemical 2]

[0028]
It is preferable that the monomer represented by these is included. Such a monomer is preferably contained as a main component of the monomer (A) having a polyalkylene glycol chain. In this case, the monomer (A) having a polyalkylene glycol chain may or may not contain other components additionally. Thereby, the reaction liquid in this invention can be used suitably as manufacturing raw materials, such as a polymer for cement additives.
[0029]
In the general formula (1), R¹ And R^Four Are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. R² Are —CO—, —CH₂ -,-(CH₂ )₂ -Or -C (CH_Three )₂ -Represents. R^Three O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms, preferably 2 to 8 carbon atoms. m is R^Three The average added mole number of the oxyalkylene group represented by O is represented by 0 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.
[0030]
R above¹ And R^Four The number of carbons exceeds 30 or the above R^Three When the carbon number of O exceeds 18, the water solubility of the polymer obtained using the reaction liquid in the present invention as a production raw material is lowered, and the application performance when used as a cement additive or the like, that is, the cement dispersion performance is lowered. There is a fear. If m exceeds 300, it may be difficult to prepare the monomer (A) having a polyalkylene glycol chain.
[0031]
R above¹ And R^Four Or R^Three The range of the preferable carbon number of O is set according to the use application of the reaction liquid in the present invention. For example, when used as a raw material for producing a polymer for cement dispersant, R¹ Is preferably a hydrogen atom or a methyl group. R^Four 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, alkyl group such as eicosyl group, heneicosyl group, docosyl group; aryl group such as phenyl group; Examples thereof include alkylphenyl groups such as phenyl group; cycloalkyl groups such as cyclohexyl group; alkenyl groups such as vinyl group, allyl group, 3-butenyl group, and 3-methyl-3-butenyl group; alkynyl groups. 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.
[0032]
R above^Three 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^Three O is a repeating unit constituting the monomer 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.
[0033]
The range of m is also set depending on the intended use of the reaction liquid in the present invention. For example, when used as a raw material for producing a polymer for cement additives, it is preferably 15 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.
[0034]
When m is 0, from the viewpoint of solubility in water and boiling point, R^Four Is preferably a hydrocarbon group having 4 or more carbon atoms. That is, when m is 0, the monomer (A) having a polyalkylene glycol chain is obtained by esterification reaction while dehydrating an alcohol and an unsaturated monomer such as (meth) acrylic acid as described later. When obtained, especially alcohols such as methanol and ethanol have a low boiling point and evaporate with the produced water and dissolve in the produced water, whereby a part of the alcohol raw material is distilled out of the reaction system and the desired polyalkylene is obtained. This is to prevent the yield of the monomer (A) having a glycol chain from being lowered.
[0035]
In the present invention, the monomer (B) having a carboxyl group is preferably (meth) acrylic acid. Thereby, the polymer manufactured using the reaction liquid in the present invention can be suitably applied to various chemical products, particularly cement additives.
[0036]
In the present invention, the reaction solution is preferably used as a raw material for producing a cement additive. That is, it is preferable to use a polymer obtained from the reaction solution in the present invention as a raw material for producing a cement additive. Thereby, in manufacture of a cement additive, the fall of the performance and quality is suppressed, and it becomes possible to manufacture stably.
[0037]
The present invention is also a reaction solution prepared by the method for preparing a reaction solution. Such a reaction solution can produce a polymer that can realize high performance and quality, pigment additive such as cement additive, calcium carbonate, carbon black, ink, scale inhibitor, dispersion for gypsum / water slurry. It is suitable as a raw material for producing a polymer that can be used in chemical products such as an agent, a dispersant for coal / water slurry (CWM), and a thickener.
[0038]
In the present invention, the method for producing a mixed liquid essentially comprising the monomer (A) having a polyalkylene glycol chain and the monomer (B) having a carboxyl group is alkoxy (poly) which is a preferred method in the present invention. The method of preparing by esterifying the alkylene glycol and the monomer (B) having an excess amount of carboxyl groups will be described in detail below.
[0039]
As the method by the esterification reaction, for example, a production method including a neutralization step, a solvent distillation step and the like can be suitably applied as necessary following the esterification reaction step.
The esterification reaction step is preferably a step in which an esterification reaction liquid containing an alkoxy (poly) alkylene glycol and an excess amount of (meth) acrylic acid is esterified. Thereby, it becomes possible to manufacture industrially simply the liquid mixture containing the monomer represented by General formula (1) and (meth) acrylic acid. The compounds used as reaction raw materials in such steps may be used alone or in combination of two or more. In addition, the monomer produced | generated by such an esterification reaction process is also called ester, esterified substance, or a dehydration reaction product.
[0040]
In the esterification reaction step, since the esterification reaction is in chemical equilibrium, the reaction proceeds when the reaction product water generated by the reaction is removed from the reaction vessel. In such a process, (1) in order to facilitate removal of reaction product water generated in the reaction vessel, if necessary, a dehydrating solvent is mixed with the reaction liquid for esterification reaction, and the dehydrating solvent and water are azeotroped. (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 for separating the condensed and liquefied distillate into dehydrated solvent and water in a water separator connected to the condenser, (4) Operation for refluxing the separated dehydrated solvent into the reaction tank, etc. Will be performed. In such a process, for example, a reaction vessel, a condenser, an esterification reaction apparatus that essentially requires a connecting pipe for connecting the reaction tank and the condenser, and a water separator connected by the condenser and a supply pipe are used. Will be done.
[0041]
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 an esterification reaction. The shape of the reaction vessel is not particularly limited. Although there are a polygonal shape and a cylindrical shape, the cylindrical shape 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. 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 the 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 in order to perform the esterification 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 Examples of the blade include a blade, a screw blade, and a max blend blade, and among them, a multi-stage fan turbine blade and a Faudler blade are preferable from the viewpoint of versatility.
[0042]
The condenser is a device that condensates and distills the distillate generated from the reaction tank, and the condensate is performed by exchanging heat between the extra-fluid fluid that is the cooling liquid and the distillate. In addition, a distillate means all what is distilled from a reaction tank by an esterification reaction process or another process. In other words, it means water that is distilled from the reaction vessel, and contains reaction raw materials such as distilled (meth) acrylic acid in addition to dehydrated solvent used to azeotrope with water as needed. And as the form, gaseous form, liquid form, etc. are mentioned.
[0043]
As the material of the capacitor, known materials such as SUS304, SUS316, SUS316L, etc., or carbon steel (CS) can be used. Preferably, the inner surface is mirror-finished in order to further reduce the generation of gel-like materials. A finished or glass-lined capacitor can be used, but from the viewpoint of processing and maintenance costs, it is preferable to use a SUS capacitor such as SUS304, SUS316, SUS316L, or preferably SUS316, SUS316L.
[0044]
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.
[0045]
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.
[0046]
The alkoxy (poly) alkylene glycol used for the esterification reaction preferably contains a compound represented by the following general formula (2). Such a compound is preferably contained as a main component in the alkoxy (poly) alkylene glycol. In this case, the alkoxy (poly) alkylene glycol may or may not contain other components additionally.
R^Four O (R^Three O) mH (2)
In general formula (2), R^Four , R^Three O and m are the same as described above.
[0047]
In the esterification 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.
[0048]
In the esterification 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.
[0049]
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.
[0050]
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 etc. of the polymer for cement additives synthesized using them will decrease. There is a risk. 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.
[0051]
[Expression 1]

[0052]
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.
[0053]
The esterification reaction is preferably performed in the presence of a polymerization inhibitor. Thereby, the polymerization of the monomer (B) having a carboxyl group in the reaction raw material and the monomer (A) having a polyalkylene glycol chain as a 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 esterification reaction step and in the solvent distillation step.
[0054]
As the usage-amount of the said polymerization inhibitor, when the total preparation amount of the alcohol 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 polymerization inhibiting ability is not sufficiently expressed, and it is difficult to effectively prevent polymerization of reaction raw materials and products, and if it exceeds 1% by weight, it remains in the reaction solution in the present invention. Since the amount of the polymerization inhibitor to be increased 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%.
[0055]
The esterification reaction operation can be performed without a dehydrating solvent, but by using a dehydrated solvent, for example, the generated water and the dehydrated solvent are azeotroped outside the reaction system, and condensed to liquefy to form product water. It is preferable to carry out by refluxing while separating and removing. Thereby, the reaction product water produced | generated by esterification 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.
[0056]
In the esterification reaction operation using the dehydrating solvent, the dehydrating solvent is preferably used in an amount of 0 to 100% by weight when the total charge of alcohol 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.
[0057]
In the esterification reaction step, the esterification 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. If the temperature is lower than 30 ° C., the dehydrating solvent is slow to be refluxed, and it takes time for dehydration, and the reaction may be difficult to proceed. If the temperature exceeds 180 ° C., a part of the reaction raw material is decomposed. In the polymer obtained from the reaction liquid in the invention, the dispersion performance and viscosity increase characteristics in various applications such as cement dispersion performance, the polymerization of the reaction raw material, the increase in the amount of the reaction raw material mixed in the distillate, The performance and quality of the reaction solution may be deteriorated.
[0058]
In the above reaction conditions, the reaction time is preferably set until the reaction rate of esterification (so-called esterification rate) reaches 70% or more as will be 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.
[0059]
The reaction rate of the esterification reaction is preferably set to be 70% or more. If it is less than 70%, the yield of the produced ester 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. will be lowered. More preferably, it is 70-99%, More preferably, it is 80-98%. The reaction rate is the ratio of the amount of alcohol as a reaction raw material when charged and the amount at the end of the reaction. For example, by measuring each peak area by liquid chromatography (LC) under the following measurement conditions. Is a value (%) calculated by the following equation.
[0060]
[Expression 2]

[0061]
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
[0062]
When an acid catalyst is used in the esterification 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 monomer (A) having a polyalkylene glycol chain obtained by the esterification reaction is suppressed, and the generation of impurities not involved in the polymerization is suppressed. It becomes possible to suppress deterioration in quality and performance. Further, when a dehydrated solvent is used, it is preferable to perform a solvent distillation step for distilling off the dehydrated solvent in order to remove the dehydrated solvent.
[0063]
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 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.
[0064]
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 weight or less, preferably 0.01 to 5% by weight, assuming that the remaining (meth) acrylic acid after the esterification reaction is 100% by weight. It is preferable. 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.
[0065]
In the neutralization method in the neutralization step, when an esterification 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 the monomer (A) having a polyalkylene glycol chain. 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.
[0066]
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 gelled product is generated. When it is 80 ° C. or lower, the formation of a gelled product is more sufficiently suppressed, but when it is lower than 0 ° C., it is difficult to stir because the reaction liquid for esterification reaction becomes viscous. In addition, it takes a long time to lower the temperature to a predetermined temperature in order to distill off water after the reaction, and it is necessary to provide a cooling means (device) to lower the temperature to a temperature lower than room temperature. Production costs may increase.
[0067]
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.
[0068]
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 step, the apparatus system used in the esterification reaction step is preferably used as it is.
[0069]
Hereinafter, a method for producing a polymer for a cement dispersant using the reaction liquid in the present invention as a production raw material, a method for producing a cement additive containing the polymer for a cement dispersant, and a method using the cement additive Will be described.
[0070]
The polymer for cement dispersant is a polycarboxylic acid obtained by polymerizing a monomer component having a monomer (A) having a polyalkylene glycol chain and a monomer (B) having a carboxyl group as essential components. An acid polymer is mentioned. 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.
[0071]
Examples of the monomer (A) having a polyalkylene glycol chain used in the production of the polycarboxylic acid polymer include methoxy (poly) ethylene glycol mono (meth) acrylate, methoxy (poly) propylene glycol mono ( (Meth) acrylate, methoxy (poly) butylene glycol mono (meth) acrylate, methoxy (poly) ethylene glycol (poly) propylene glycol mono (meth) acrylate, methoxy (poly) ethylene glycol (poly) butylene glycol mono (meth) acrylate, Methoxy (poly) propylene glycol (poly) butylene glycol mono (meth) acrylate, methoxy (poly) ethylene glycol (poly) propylene glycol (poly) butylene glycol mono (meth) acrylate , Ethoxy (poly) ethylene glycol mono (meth) acrylate, ethoxy (poly) propylene glycol mono (meth) acrylate, ethoxy (poly) butylene glycol mono (meth) acrylate, ethoxy (poly) ethylene glycol (poly) propylene glycol mono ( (Meth) acrylate, ethoxy (poly) ethylene glycol (poly) butylene glycol mono (meth) acrylate, ethoxy (poly) propylene glycol (poly) butylene glycol mono (meth) acrylate, ethoxy (poly) ethylene glycol (poly) propylene glycol ( Poly (alkylene glycol mono (meth) acrylates such as poly) butylene glycol mono (meth) acrylate, allyl alcohol, methallyl alcohol, 3-butene- Alkylene oxide adducts to alcohols such as -ol, 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol; Examples include alkylene oxide adducts to amino group-containing monomers; etherified products of polyalkylene glycol monoethers and allyl alcohol, and the like. Examples of the monomer (B) having a carboxyl group include unsaturated groups such as (meth) acrylic acid, crotonic acid, tiglic acid, citronellic acid, undecylenic acid, elaidic acid, erucic acid, sorbic acid, and linoleic acid. Monocarboxylic acids; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid and itaconic acid; monoesters of these dicarboxylic acids and alcohols, monovalent metal salts, Examples thereof include valent metal salts, ammonium salts, and organic amine salts.
[0072]
If necessary, the polycarboxylic acid polymer may be copolymerized with a monomer other than the monomer (A) having a polyalkylene glycol chain and the monomer (B) having a carboxyl group. That is, the reaction liquid in the present invention can contain a monomer other than the monomer (A) having a polyalkylene glycol chain and the monomer (B) having a carboxyl group. 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- Examples thereof include aromatic vinyls such as methylstyrene; esters of (meth) acrylic acid with an alcohol having a phenyl group such as an aliphatic alcohol having 1 to 18 carbon atoms, preferably 1 to 15 carbon atoms, and benzyl alcohol.
[0073]
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.
[0074]
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.
[0075]
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
[0076]
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.
[0077]
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.
[0078]
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.
[0079]
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.
[0080]
As the amount of the cement dispersant added to the hydraulic material, an excellent effect can be obtained even when added in a small amount compared to 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 is substantially peaked, which is disadvantageous from the viewpoint of economy. There is a fear. More preferably, it is preferably 0.01 to 1% by 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.
[0081]
DETAILED DESCRIPTION OF THE INVENTION
Regarding the method for preparing a reaction solution of the present invention, an embodiment of a method for removing a part or all of polymer aggregates from a mixed solution and a method for adjusting components will be described. In addition, these embodiment is an illustration for demonstrating this invention more concretely, and embodiment of this invention is not restricted to these.
[0082]
First, since a filtration method is suitable as a method for removing a part or all of the polymer aggregates from the mixed solution, this method will be described with reference to FIGS. 1 and 2.
FIG. 1 is a conceptual diagram showing an apparatus configuration for performing a partial filtration method. In FIG. 1, a container, a strainer, and a pump are provided, and each is connected so that it may circulate by piping. In this case, it is set so that the mixed liquid is put in the container and the mixed liquid in the container is circulated. In such an apparatus configuration, partial filtration can be performed by circulating a part of the mixed liquid in the container through a strainer which is a filtering means. At this time, if the mixed liquid in the container is stirred with a stirrer or the like, partial filtration can be performed efficiently.
[0083]
FIG. 2 is a conceptual diagram showing a device configuration for performing the total filtration method. In FIG. 2, a container, a strainer, a pump, and another container are provided, and each is connected by piping. In this case, it is set so that the mixed liquid is put in the container 1 and the mixed liquid in the container 1 is transferred to another container 2. In such an apparatus configuration, all the mixed liquid in the container 1 can be passed through a strainer, which is a filtering means, and transferred to another container 2, whereby total filtration can be performed. Also at this time, if the mixed liquid in the container 1 is stirred by a stirrer or the like, total filtration can be efficiently performed.
[0084]
In any of the above filtration methods, in order to filter the mixed solution, the mixed solution prepared in a separate container and stored and / or transferred as necessary may be put into the container. You may perform the used reaction tank as the said container. Moreover, it is good also considering the said container as a reaction tank which performs a polymerization reaction.
[0085]
In the above filtration method, for example, the filtration time is particularly limited as long as the filtration time is appropriately set in consideration of work efficiency, performance and quality of the polymer produced using the reaction liquid, and the like. It is not a thing. Moreover, what is necessary is just to perform at normal temperature as filtration temperature normally.
[0086]
Next, as a method for adjusting the components, an esterification reaction between alkoxy (poly) alkylene glycol and a monomer (B) having an excessive amount of carboxyl groups, which is a preferred method for preparing a mixed solution in the present invention. The case where the method of preparing by carrying out is performed is demonstrated using the reaction formula of the following esterification reaction.
[0087]
[Chemical 3]

[0088]
In the formula, PG represents alkoxy (poly) alkylene glycol, MA represents methacrylic acid, PM represents a monomer (A) having a polyalkylene glycol chain, and SA represents sulfuric acid which is an acid catalyst. And CH represents cyclohexane as a dehydrating solvent. Moreover, 115 degreeC represents performing esterification of this reaction formula at this temperature.
[0089]
The results of calculating the mass balance in the above reaction formula are shown in Table 1. In this table, X represents the number of moles of PG, (X + Y) represents the number of moles of MA, Y represents the number of moles of MA in excess relative to X, and e represents all PGs. The ratio of esterification is set to 1 when esterified, and the value of e × 100 is the esterification rate (%). eX represents the number of moles of PM and water to be generated, Y + (1-e) X represents the number of moles of MA remaining unreacted, and (1-e) X is the number of moles of PG remaining unreacted. Represents. Similarly, the molecular weight and the number of grams (g) are also expressed corresponding to the substances in the above reaction formula. Further, when the number of moles of SA is set to 2% by weight with respect to the total weight of the reaction raw materials PG and MA, the weight of CH is calculated by the following formula (1). When set to 5% by weight with respect to the total weight, it is calculated by the following formula (2). When the weight of PTZ is set to 250 ppm with respect to the total weight of the reaction raw materials PG and MA, the following formula (3) Calculated.
0.02 × {1132X + 86 (X + Y)} (1)
0.05 × {1132X + 86 (X + Y)} (2)
250x10^-6× {1132X + 86 (X + Y)} (3)
[0090]
[Table 1]

[0091]
Table 2 shows the results of calculation of the material balance when the neutralization step and the solvent distillation step were performed following the esterification reaction represented by the above reaction formula. In Table 2, the esterification rate is set to 98.0%, and calculation is performed for the case where sodium hydroxide is used as the neutralizing agent in the neutralization step.
[0092]
[Table 2]

[0093]
In Table 2, the column before the reaction shows the number of grams (g) and the number of moles as the supply amount when each reaction raw material is supplied to the reaction system. The supply amounts of PG, MA, SA, PTZ and CH are amounts when the esterification reaction step is performed, and the supply amounts of water are amounts when the neutralization step is performed. In the column after the reaction, as the composition of the reaction system after the solvent distillation step, the gram (g), the number of moles, and the weight ratio (wt%) when the total amount after reaction shown in Table 2 is 100 wt%. Is shown. The total weight ratio of the monomers (PG, MA and SMA) after the reaction is 75.3%. In addition, SMA represents sodium methacrylate produced by neutralizing MAA, and SSA represents sodium sulfate produced by neutralizing SA. Note that the reaction product water produced by the esterification reaction and sodium hydroxide used as a neutralizing agent are not considered.
[0094]
here,
The amount of water in the target composition is
0.1 + 0.3 + 20.9 = 21.3%
The TCAV in the target composition is
(253.7 + 13.4) x 56110/187234
= 80.0 mg-KOH / g
And calculated.
As shown in Table 2, the mass balance of the above reaction formula is calculated as follows.
(1) Esterification rate: 98.0%
(2) TCAV: 80.0 mg-KOH / g
(3) Moisture: 21.3% by weight
[0095]
Actually, MA and water are distilled off together with cyclohexane, and when the polymer aggregate (C) is formed and a part or all of this is removed, it is shown in the column after reaction in Table 2. It will not be such a composition. Therefore, as a control value, for example, in the case of the above reaction formula, by preparing the following settings and adjusting the components, a reaction solution capable of stably maintaining the performance and quality of the obtained polymer is prepared. Is possible. In this case, it is preferable to manage the TCAV value. More preferably, it is performed in combination with managing the esterification rate and the moisture value.
[0096]
Management value
(1) Esterification rate: 98.0 ± 0.5%
(2) TCAV: 80.0 ± 2.0 mg-KOH / g
(3) Moisture: 21.3 ± 0.5% by weight
[0097]
In order to actually know the amount of each substance after the reaction shown in Table 2, for example, for PM and PG, a method of measuring the ratio of both by (high performance) liquid chromatography and calculating the content of each And the esterification rate can be calculated from the ratio. About MA and SMA, it can obtain | require as TCAV by titrating a part of reaction liquid as a sample. Further, SA, SSA, and PTZ can be obtained from the amount supplied into the reaction system, and water can be obtained using a water content measurement method by the Karl Fischer method. Thus, after measuring the quantity of each substance after reaction, a component adjustment is performed so that it may become in the range of a control value.
[0098]
[Table 3]

[0099]
Table 3 illustrates the measured values of the total amount, TCAV and moisture before and after adjusting the components for the case of managing TCAV and moisture values. In this case, the component is adjusted with the control value as a target, and MA and H₂ The number of grams of O (g) will be adjusted. MA and H₂ When increasing the number of grams (g) of O, it is shown as a positive number, and when decreasing, it is shown as a negative number. At this time, MA and H₂ If adjustment is not possible simply by adding O, once heated, MA or H₂ It can adjust by adding, after removing a part of O. When heating, it is preferable to appropriately combine operations such as (1) stirring, (2) depressurization, and (3) bubbling an inert gas such as nitrogen gas into the liquid. When stirring or bubbling inert gas into the liquid, MA and H₂ O is easily distilled off, and the removal of these is promoted. When the pressure is reduced, it becomes easier to volatilize at a low temperature and it is easily distilled off in a short time. Thus, by adjusting the components with the control value as a target, the reaction solution can be used as a production raw material capable of maintaining the performance and quality of the polymer more reliably and stably.
[0100]
【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”.
[0101]
Production Example 1
An autoclave equipped with a thermometer, a pressure gauge, and a stirrer was charged with 4 parts of flaky sodium hydroxide, and nitrogen substitution was sufficiently performed by repeating nitrogen pressurization and exhaust. Next, 575 parts of methanol was charged, and the temperature of this mixed solution was raised to 90 ° C. The initial pressure was set to 0.15 MPa, and 7900 parts of ethylene oxide was added over 8 hours. During this period, the reaction temperature was maintained at 125 ± 5 ° C., and the reaction pressure was maintained at 0.78 MPa or less. Further, the reaction temperature was maintained for 2 hours to complete the addition reaction of ethylene oxide to methanol. Methoxypoly (n = 10) ethylene glycol [CH = 10 mol of ethylene oxide per 1 mol of methanol]_Three O (CH₂ CH₂ O)_TenH] was obtained. The peroxide value immediately after the addition reaction of the alkoxypolyalkylene glycol (1) thus obtained was measured as follows and found to be 0.0 meq / g.
[0102]
Method for measuring peroxide value
10 g of alkoxypolyalkylene glycol was precisely weighed in an Erlenmeyer flask equipped with a stopcock, and 50 ml of a solvent (mixed solution of 500 ml of isopropyl alcohol, 100 ml of water and 150 ml of acetic acid) was added to dissolve the sample. When the sample was dissolved, 1 ml of saturated potassium iodide was added while the inside of the flask was replaced with nitrogen gas, stirred for 1 minute, and left in the dark for 30 minutes to prepare a yellow transparent test solution. Next, 0.01N sodium thiosulfate was added dropwise to the test solution until the brown color of the test solution disappeared, and the titration amount (ml) of sodium thiosulfate at this time was measured. Prices were calculated. In addition, the blank value (ml) was obtained by performing operation similar to the above except having used the test solution which does not add alkoxy polyalkylene glycol instead of the test solution.
[0103]
[Equation 3]

[0104]
Production Example 2
An autoclave equipped with a thermometer, a pressure gauge, and a stirrer was charged with 751 parts of alkoxypolyalkylene glycol (1), and nitrogen substitution was sufficiently performed by repeating nitrogen pressurization and exhaust. After setting the temperature to 153 ° C., the pressure was set to 0.15 MPa, and 1050 parts of ethylene oxide was added over 6 hours. During this period, the reaction temperature was maintained at 153 ± 5 ° C., and the reaction pressure was maintained at 0.78 MPa or less. The reaction temperature was maintained for an additional hour to complete the addition reaction of ethylene oxide to methanol. Methoxypoly (n = 25) ethylene glycol [CH = 25 mol of ethylene oxide added to 1 mol of methanol [CH_Three O (CH₂ CH₂ O)_{twenty five}H] was obtained. The peroxide value immediately after the addition reaction of the alkoxypolyalkylene glycol (2) thus obtained was measured and found to be 0.0 meq / g.
[0105]
Save
The alkoxypolyalkylene glycol (2) was stored in a tank sealed with a gas (AIG gas) controlled to have an oxygen concentration of 0.5 to 1.0% by volume at a temperature of 50 to 60 ° C. for 3 months. At this time, the peroxide value of the alkoxypolyalkylene glycol, which normally had to have a peroxide value of 1.0 meq / g or less, increased to 2.4 meq / g.
[0106]
Example 1
Esterification
In a glass reaction vessel equipped with a thermometer, a stirrer, a product water separator and a reflux condenser, 11320 parts of alkoxypolyalkylene glycol (peroxide value: 2.4 meq / g), 3320 parts of methacrylic acid, as a dehydrating solvent Was charged with 730 parts of cyclohexane, 293 parts of p-toluenesulfonic acid monohydrate as an acid catalyst, and 3.7 parts of phenothiazine as a polymerization inhibitor. The conversion reaction was started. After 20 hours, it was confirmed that the esterification rate reached 98%, and the mixture was cooled to 60 ° C. or lower, and 1740 parts of a 4.2% aqueous sodium hydroxide solution and 1923 parts of water were added. Next, the temperature was raised again, and cyclohexane was driven off by azeotropy with water to obtain a monomer mixture (M1). The monomer mixture (M1) contained a gel polymer (polymer aggregate).
[0107]
Filtration
The monomer mixture (M1) was transferred to another container by a pump. A bucket-type strainer (60 mesh, 4 inches in diameter) was attached in front of the pump to filter the gel polymer in the monomer (M1). The filtered gel polymer was 320 parts. Filtration (M2) was obtained by filtration.
[0108]
Analysis and adjustment
The obtained filtrate (M2) was 18250 parts, TCAV was 82.0 mg-KOH / g, moisture was 19.2%, and the esterification rate was 98.0%. Since the target TCAV was 87.0 ± 1.5 mg-KOH / g, the water content was 19.5 ± 0.5%, and the esterification rate was 98% or more, 178.methacrylic acid was added to the filtrate (M2). 5 parts and 111.3 parts of water were added to obtain a monomer mixture (M3). The monomer mixture (M3) from which the gel polymer was removed had a TCAV of 87.0 mg-KOH / g, a water content of 19.0%, and an esterification rate of 98.0%. The results are shown in Table 4.
[0109]
[Table 4]

[0110]
polymerization
Next, 8220 parts of water was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, and the inside of the reaction vessel was replaced with nitrogen gas while stirring. The water temperature was heated to 80 ° C. Furthermore, a solution obtained by adding 100 parts of mercaptopropionic acid to 13250 parts of the monomer mixture (M3) obtained above was dropped into the reaction vessel over 4 hours. An aqueous solution having 1000 parts dissolved therein was added dropwise over 5 hours. After completion of the addition of the polymerization initiator, the reaction temperature was maintained at 80 ° C. for another 1 hour to complete the polymerization reaction, and the reaction solution was neutralized with 50% aqueous sodium hydroxide solution to pH 7 to obtain a weight average molecular weight (gel Polyethylene glycol conversion by permeation chromatography (GPC): hereinafter the same) 20000 aqueous polymer solution (P1) was obtained.
There was no high molecular weight peak in the GPC chart of the aqueous polymer solution (P1). Further, the polymer aqueous solution (P1) was taken in a transparent glass bottle (200 ml), and the appearance was visually confirmed. However, there was no gel, and no gel accumulated in the strainer of the transfer pump.
[0111]
Comparative Example 1
Polymerization was carried out in the same manner as in Example 1 except that the monomer mixture (M1) was used for the polymerization instead of the monomer mixture (M3). That is, polymerization was performed after analysis and adjustment without filtration. The gel-like polymer in the monomer mixture (M1) caused clogging of the pump, and the monomer solution could not be dropped at a constant rate. In addition, gel was visually observed in the obtained polymer (G1). Since the gel acts as a coagulant in the cement composition and adversely affects cement dispersion performance, the polymer (G1) containing the gel was discarded.
[0112]
【The invention's effect】
Since the method for preparing a reaction solution of the present invention has the above-described configuration, it is possible to produce a polymer that achieves high performance and quality, generation of defects in the production process, and performance and quality of various chemical products. That is, it is possible to sufficiently suppress the decrease in the above. The polymer produced from the reaction solution of the present invention includes cement additives, calcium carbonate, carbon black, pigment dispersants such as ink, scale inhibitors, gypsum / water slurry dispersant, 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 apparatus configuration for performing a partial filtration method according to the present invention.
FIG. 2 is a conceptual diagram showing an apparatus configuration for performing a total filtration method in the present invention.

Claims (8)

And with a mixture containing monomer and (B) a polymer agglomerates and (C) having a monomer (A) and the carboxyl groups of the polyalkylene glycol chain in the polymerization reaction, a raw material for cement additive A method for preparing a reaction solution used as
A step of removing a part or all of the polymer aggregate (C) from the mixed solution by a filtration method , the total amount of the reaction solution, and the inclusion of the monomer (B) having a carboxyl group in the reaction solution And a step of adjusting the composition by adjusting the composition of the reaction solution after measuring the amount. In the preparation method, it is essential to measure and manage the content of the monomer (B) having a carboxyl group as the total amount of carboxylic acid in 1 g of the reaction solution (in terms of mg of KOH). A method for preparing the reaction solution according to claim 1. The preparation method comprises a step of esterifying an alkoxy (poly) alkylene glycol and a monomer (B) having an excess amount of carboxyl groups to prepare a mixed solution, the step comprising the esterification The method for preparing a reaction solution according to claim 1 or 2, wherein the component adjustment is essential by adjusting the esterification rate of the reaction. The method for preparing a reaction solution according to claim 3, wherein the esterification rate is 98.0 ± 0.5%. The method for removing a part or all of the polymer aggregate (C) from the mixed solution by a filtration method is a total filtration method by filtering the entire mixed solution. A method for preparing a reaction solution according to any one of the above. The method for preparing a reaction solution according to claim 5, wherein the filtration method uses a strainer. The monomer (A) having a polyalkylene glycol chain is represented by the following general formula (1);

(Wherein, ^{R 1} and ^{R 4} are the same or different, a hydrogen atom, or, ^.R 2 representing a hydrocarbon group having 1 to 30 carbon _{atoms, -CO -, - CH 2 -} , - (CH 2 ) ₂ -or -C (CH ₃ ) _2- , R ³ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms, m is an oxyalkylene group represented by R ³ O The average addition mole number of this is represented, and it is the number of 0-300.) The reaction liquid preparation method in any one of Claims 1-6 characterized by the above-mentioned. The method for preparing a reaction solution according to claim 1, wherein the monomer (B) having a carboxyl group is (meth) acrylic acid.

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