JP4055058B2 - Process for producing polyarylene sulfide - Google Patents

Description

【００１４】
前記一般式（１）〜（４）中、Ｘはハロゲン原子を、またＹは水素原子、水酸基、炭素数１〜１８のアルキル基、炭素数３〜１８のシクロアルキル基、炭素数６〜１８のアリール基、カルボキシル基、炭素数１〜１８のアルコキシカルボニル基、ナトリウムカルボキシレート基、シアノ基、アミノ基若しくはニトロ基を表す。また、前記Ｘは塩素または臭素が好ましい。
【００１５】
また、一般式（４）中のＶは、下記構造式（５）〜（１０）で表わされる２価の連結基を表す。
【化２】

（式中、Ｒ’及びＲ”は、それぞれ独立に、水素原子、炭素数１〜１８のアルキル基、炭素数３〜１８のシクロアルキル基、炭素数６〜１８のアリール基を表す。）
【００１６】
一般式（１）中のｍは２を、ｎは、０〜４の整数を表す。また、一般式（２）中のａは２を、ｂは０〜６の整数を表す。一般式（３）中でｃは０〜２、ｄは０〜２、ｅは０〜３、ｆは０〜２の整数をそれぞれ表わし、且つｃとｄはｃ＋ｄ＝２を満足する。また、一般式（４）中でｇは０〜２、ｈは０〜２で且つｉ及びｊは、０≦ｉ、及びｊ≦２を満足する整数を表す。
【００１７】
前記、一般式（１）〜（４）のジハロ芳香族化合物の具体例としては、ｐ−ジハロベンゼン、ｍ−ジハロベンゼン、ｏ−ジハロベンゼン、２，５−ジハロトルエン、１，４−ジハロナフタリン、１−メトキシ−２，５−ジハロベンゼン、４，４’−ジハロビフェニル、３，５−ジハロ安息香酸、２，４−ジハロ安息香酸、２，５−ジハロニトロベンゼン、２，４−ジハロニトロベンゼン、２，４−ジハロアニソール、２，５−ジハロアニリン、３，５−ジハロアニリン、ｐ，ｐ’−ジハロジフェニルエーテル、４，４’−ジハロベンゾフェノン、４，４’−ジハロジフェニルスルホン、４，４’−ジハロジフェニルスルホキシド、４，４’−ジハロジフェニルスルフィド等であり、なかでも、ｐ−ジハロベンゼン、ｍ−ジハロベンゼン、４，４’−ジハロベンゾフェノンおよび４，４’−ジハロジフェニルスルホンが好ましく、その中でもｐ−ジクロロベンゼン、ｍ−ジクロロベンゼン、４，４’−ジクロロベンゾフェノンおよび４，４’−ジクロロジフェニルスルホンは特に好適に使用される。
【００１８】
ジハロ芳香族化合物の適当な選択組み合わせによって２種以上の異なる反応単位を含む共重合体を得ることもでき、その組み合わせには特に制限はない。ｐ−ジクロロベンゼンと４，４’−ジクロロベンゾフェノンもしくは４，４’−ジクロロフェニルスルホンとを組み合わせて使用すれば、種々の物性に優れたＰＡＳを得ることができるので、好ましい。また、ｐ−ジハロベンゼンをジハロ芳香族化合物中７０モル％以上、好ましくは９０モル％以上、更に好ましくは９５モル％以上用いて重合すると種々の物性に優れたＰＡＳが得られるのでとくに好ましい。また、ジハロベンゼンのみの重合体であるＰＰＳは種々の物性に優れており、中でもジクロロベンゼンの使用は生産性等の点でより好ましい。
【００１９】
なお、本発明によるＰＡＳは上記ジハロ芳香族化合物の重合体であるが、生成重合体の末端を形成させるため、あるいは重合反応ないし分子量を調節するためにモノハロ化合物を併用することも、分岐または架橋重合体を形成させるためにトリハロ以上のポリハロ化合物を併用することも可能である。これらのモノハロまたはポリハロ化合物を併用する場合は、例えばジハロベンゼンに若干量のトリクロロベンゼンを組み合わせて使用すれば、分岐を持ったフェニレンスルフィド重合体を得ることができ、トリクロロベンゼン等の３個以上のハロゲン原子を置換基として有するポリハロ化合物の使用は得られるポリマーの高粘度化の点で有用である。また、モノハロ化合物または３個以上のハロゲン原子を置換基として有するポリハロ化合物の使用量は目的あるいは反応条件によっても異なるので一概に規定できないが、ジハロ芳香族化合物１モルに対して好ましくは０．１モル％以下、更に好ましくは０．０６モル％以下である。トリクロロベンゼンに代表される３個以上のハロゲン原子を置換基として有するポリハロ化合物の使用量が上記範囲の場合には、得られるポリマーのリニアリティーをほとんど損なうことなく、高粘度化できるので好ましい。なお、モノハロ化合物及び３個以上のハロゲン原子を置換基として有するポリハロ化合物は共に必ずしも芳香族化合物でなくとも良い。
【００２０】
本発明の重合反応に使用する有機極性溶媒は、活性水素を有しない有機極性溶媒、すなわちアプロチックタイプの有機極性溶媒である。
【００２１】
前記有機極性溶媒は、前記重合反応を阻害せず、原料であるジハロ芳香族化合物及びＳ^２−を与える含水スルフィド化剤を反応に必要な濃度に溶解することができる程度の溶解能を持つものであれば、とくに限定されない。これらの中でも、この溶媒は、窒素原子、酸素原子、硫黄原子を有する極性溶媒であることが普通である。更に、この溶媒は原料ジハロ芳香族化合物と同様な脱ハロゲン化／硫化反応に関与しうるものでないことが望ましい。従って例えばハロ芳香族炭化水素ではないことが望ましい。
【００２２】
前記有機極性溶媒は、制御された少量の水を重合反応に提供するためのものであるから、溶質としてのこの水が溶媒和しうるものであることが望ましい。
【００２３】
また、本発明の製造方法から明らかなように、前記有機極性溶媒の沸点は水の沸点より高いことが望ましい。前述の条件を満足するものとしては、例えば、（１）アミド類、例えば、ヘキサメチルリン酸トリアミド（ＨＭＰＡ）、Ｎ−メチルピロリドン（ＮＭＰ）、Ｎ−シクロヘキシルピロリドン（ＮＣＰ）、Ｎ−メチルカプロラクタム、テトラメチル尿素（ＴＭＵ）、ジメチルホルムアミド（ＤＭＦ）、ジメチルアセトアミド（ＤＭＡ）等、（２）エーテル化ポリエチレングリコール類、例えばポリエチレングリコールジアルキルエーテル（重合度は２０００程度まで、アルキル基はＣ_１〜Ｃ_２０程度）等、（３）スルホキシド類、例えば、テトラメチレンスルホキシド、ジメチルスルホキシド（ＤＭＳＯ）等が挙げられる。前記溶媒の中でも、Ｎ−メチルカプロラクタムおよびＮＭＰは、化学的安定性が高いので、特に好ましい。
【００２４】
前記有機極性溶媒の使用量は、使用する溶媒の種類及び系内の溶媒に対する水分量によっても異なるが均一な重合反応が可能な反応系の粘度を保持すること、また、ある程度の生産性を維持するためには、重合に用いる含水スルフィド化剤中の硫黄原子１モル当り１．０〜８．０モルの範囲が好ましい。また、生産性を更に考慮すると、重合に用いる含水スルフィド化剤中の硫黄原子１モル当り１．０〜６．０モルの範囲が好ましく、また、更に好ましい使用溶媒量は重合に用いる含水スルフィド化剤中の硫黄原子１モル当り１．２〜５．０モルである。
【００２５】
重合系内の水分量、あるいは含水スルフィド化剤の水分量を調整するための水は、反応を阻害するものが含まれなければ良く、そのため蒸留水、イオン交換水等、反応を阻害するアニオンやカチオン等を除いた水が好ましい。
【００２６】
本発明の重合反応に存在させる水分は、加水分解反応などの併発を回避させるために、なるべく少ない方が良い。他方、重合反応が全く無水の状態である場合は、反応速度が著しく遅くなるといった問題がある。従って、本発明の重合反応において反応系内に存在すべき水分量は、重合に使用した該含水スルフィド化剤１モルに対して、重合反応終了時１モル未満でなければならない。また、反応が円滑に進行する点からは、重合に使用した該含水スルフィド化剤１モルに対して、０．０２モル以上存在させることが好ましい。これらの中でも重合に使用した該含水スルフィド化剤１モルに対して０．０３〜０．６０の範囲が好ましく、０．０５〜０．４０の範囲が特に好ましい。上記範囲を満たす場合には、反応速度の制御の制御性、及び高分子量化の両立がより容易に行える。
【００２７】
本発明においては、有機極性溶媒中で、ジハロ芳香族化合物と含水スルフィド化剤とを反応させるポリアリーレンスルフィドの製造において、含水スルフィド化剤がアルカリ金属硫化物とアルカリ金属水硫化物の混合物であり、重合反応終了時の反応系内の水と重合に使用した全該含水スルフィド化剤とのモル比（水／含水スルフィド化剤）が１未満で、重合反応終了時の残存するジハロ芳香族化合物と含水スルフィド化剤とのモル比（ジハロ芳香族化合物／含水スルフィド化剤）が１より小さいことを特徴とする。
【００２８】
含水スルフィド化剤を用いる本発明の製造方法の特徴を満たすためには脱水が必要となるが、本発明としては脱水と重合を同時に行っても良いし、あるいは脱水と重合を別々に行っても良いし、あるいは重合を行いながら適宜脱水を行っても良い。
【００２９】
脱水と重合を同時に行う方法としては、例えば重合反応が実質的に進行し得る温度、２００〜３００℃、好ましくは２１０〜２８０℃、更に好ましくは２１５〜２６０℃の温度に有機極性溶媒（有機極性溶媒に対して０．５モル以下の水を含んでいて良い）及びジハロ芳香族化合物の混合物を加熱して、反応系内の水分量が上記範囲内にコントロールされ得る速度で含水スルフィド化剤を混合物に導入して余分の水を系外に除去し、反応系内の水分量を上記範囲内にコントロールした後、さらに２００〜３００℃、好ましくは２１０〜２８０℃の温度に加熱して４０時間以下、好ましくは０．５〜２０時間、更に好ましくは１〜１０時間加熱して重合反応を行う方法でも良い。
【００３０】
また、脱水と重合を別々に行う方法としては、例えば重合反応が、ほとんど進行しない温度、即ち１２０〜２００℃、好ましくは１５０〜１９０℃に有機極性溶媒（有機極性溶媒に対して０．５モル以下の水を含んでいて良い）及びジハロ芳香族化合物の混合物を保ち、反応系内の水分量を含水スルフィド化剤１モルに対して１モル未満にコントロールされ得る速度で含水スルフィド化剤を混合物に導入して余分の水を系外に除去し、反応系内の水分量を含水スルフィド化剤１モルに対して１モル未満にコントロールした後、調製した有機極性溶媒、ジハロ芳香族化合物及び含水スルフィド化剤の混合物を重合反応が実質的に進行する温度、即ち、２００〜３００℃、好ましくは２１０〜２８０℃の温度に加熱して４０時間以下、好ましくは０．５〜２０時間、更に好ましくは１〜１０時間加熱して重合反応を行う方法でも良い。
【００３１】
また、重合を行いながら適宜脱水を行う方法としては、例えば、下記の方法が挙げられる。
【００３２】
▲１▼重合反応がほとんど進行しない温度、即ち１２０〜２００℃、好ましくは１５０〜１９０℃に有機極性溶媒（有機極性溶媒に対して０．５モル以下の水を含んでいて良い）及びジハロ芳香族化合物の混合物を保ち、反応系内の水分量がコントロールできる速度で含水スルフィド化剤を混合物に導入して余分の水を系外に除去し、反応系内の水分量を反応系内の含水スルフィド化剤１モルに対して１モル未満にコントロールした後、調製した有機極性溶媒、ジハロ芳香族化合物及び含水スルフィド化剤の混合物を重合反応が実質的に進行する温度、即ち、２００〜３００℃、好ましくは２１０〜２８０℃の温度に加熱して０．１〜４０時間、好ましくは０．５〜２０時間、更に好ましくは１〜１０時間加熱して重合反応を行い、重合反応を行っている間に、必要に応じて更に連続的にあるいは一時的にあるいは断続的に系内の水分を除去して更に水分量を低減する重合方法。
【００３３】
▲２▼重合反応が進行し得る温度、２００〜３００℃、好ましくは２１０〜２８０℃、更に好ましくは２１５〜２６０℃の温度に有機極性溶媒（有機極性溶媒に対して０．５モル以下の水を含んでいて良い）及びジハロ芳香族化合物の混合物を加熱して、反応系内の水分量がコントロールされ得る速度で含水スルフィド化剤を混合物に導入して余分の水を系外に除去し、反応系内の水分量を反応系内の含水スルフィド化剤１モルに対して１モル未満になるようにコントロールした後、さらに２００〜３００℃、好ましくは２１０〜２８０℃の温度に加熱して４０時間以下、好ましくは０．５〜２０時間、更に好ましくは１〜１０時間加熱して重合反応を行い、重合反応を行っている間に、連続的にあるいは一時的にあるいは断続的に系内の水分を除去して更に水分量を低減する重合方法。
【００３４】
上記重合方法の中でも、生産性等の点から、重合を行いながら適宜脱水をする方法が好ましい。これらの中でも重合反応が実質的に進行し得る温度に有機極性溶媒及びジハロ芳香族化合物の混合物を加熱して、反応系内の水分量がコントロールされ得る速度で含水スルフィド化剤を混合物に導入して余分の水を系外に除去し、反応系内の水分量をコントロールした後、さらに重合反応を行い、重合反応を行っている間に、必要に応じて連続的にあるいは一時的にあるいは断続的に系内の水分を除去して更に水分量を低減する重合方法が好ましく、特に重合工程全般を通じて反応系内の水分量が、反応系内の含水スルフィド化剤１モルに対して１モル未満になっている重合方法（前記▲２▼）が最も好ましい。
【００３５】
上記の含水スルフィド化剤を導入する速度は反応系内の水分量を該有機極性溶媒１モルに対して目的の範囲にコントロールできるように余分の水を系外に除去できる速度であれば特に制限はない。導入時間はコントロールする水分量、導入する際の温度、含水スルフィド化剤の含水率等によっても異なるので一概には規定できないが、含水スルフィド化剤を０．１〜２０時間、好ましくは０．５〜１０時間かけて導入することが好ましい。この時間内であると、反応系の水分量あるいは温度等を制御しやすく、また生産性も良い。
【００３６】
また、含水スルフィド化剤を導入する温度もコントロールする水分量、導入する際の速度、含水スルフィド化剤の含水率あるいは反応の形式によっても異なるので一概には規定できないが、脱水と重合を別々に行うのであれば、１２０〜２００℃、好ましくは１５０〜１９０℃で導入すると良い。また、脱水と重合を同時に行うのであれば、２００〜３００℃、好ましくは２１０〜２８０℃、更に好ましくは２１５〜２６０℃の温度で導入すれば良い。
【００３７】
重合反応は、２００〜３００℃、好ましくは２１０〜２８０℃の温度に加熱して０．１〜４０時間、好ましくは０．５〜２０時間、更に好ましくは１〜１０時間加熱して行うことが好ましい。この範囲内であると反応の進行がスムーズである。
【００３８】
なお、重合時の水の除去方法としては、反応系の温度・圧力をコントロールすることによって容易に行える。即ち、水、溶媒、ジハロ芳香族化合物の各蒸気圧曲線によりコントロールすべき温度・圧力が容易に推定でき、その温度・圧力でコントロールすれば所望の系内水分量にすることができる。
【００３９】
本発明の製造方法において使用するジハロ芳香族化合物及び含水スルフィド化剤の使用量には、重合反応終了時の残存するジハロ芳香族化合物と残存する含水スルフィド化剤とのモル比（ジハロ芳香族化合物／含水スルフィド化剤）が１未満であれば、特に制限はない。例えば、ジハロ芳香族化合物と含水スルフィド化剤とを添加する方法としては、下記の（ａ）、（ｂ）の方法が挙げられる
（ａ）予め、重合反応終了時の残存するジハロ芳香族化合物と残存する含水スルフィド化剤とのモル比（ジハロ芳香族化合物／含水スルフィド化剤）が１未満となるように、ジハロ芳香族化合物と含水スルフィド化剤とを仕込んで、反応してもよい。また、（ｂ）重合反応終了時の残存するジハロ芳香族化合物と残存する含水スルフィド化剤とのモル比（ジハロ芳香族化合物／含水スルフィド化剤）が１以上になるように、ジハロ芳香族化合物と含水スルフィド化剤とを仕込んだ後、重合途中でジハロ芳香族化合物を系外に除去して、重合反応終了時の残存するジハロ芳香族化合物と残存する含水スルフィド化剤とのモル比（ジハロ芳香族化合物／含水スルフィド化剤）が１未満となるように調整してもよい。これらの中でも、前記（ａ）が好ましい。
【００４０】
前記（ａ）または（ｂ）の方法の何れの場合でも、重合反応終了時の残存するジハロ芳香族化合物と残存する含水スルフィド化剤とのモル比（ジハロ芳香族化合物／含水スルフィド化剤）が１未満であることが必須であり、１以上の場合には本発明の目的であるポリマーの高分子量化が達成できず、好ましくない。但し、あまり小さすぎるとポリマーの分解反応により、分子量低下が起こりえるため、０．０５以上であることが好ましい。これらの中でも、重合反応終了時の残存するジハロ芳香族化合物と残存する含水スルフィド化剤とのモル比（ジハロ芳香族化合物／含水スルフィド化剤）が０．１〜０．５の範囲が特に好ましい。この範囲を満たす場合には分解反応を併発することなく、より高分子量化を達成し得る。
【００４１】
従って前記（ａ）または（ｂ）の方法の何れの場合でも、〔（全使用ジハロ芳香族化合物（モル））−（系外に除去したジハロ芳香族化合物（モル））〕と〔（全使用含水スルフィド化剤（モル））−（系外に除去した硫黄分（モル））〕との比が０．９０より大きく１より小さい範囲が物性の優れたポリマー、即ちより高分子量のポリマーを得るのに好ましい。上記範囲を満たす場合には、前記の残存するモノマー比の好ましい範囲を満足しやすいので好ましい。また、上記範囲が０．９２〜０．９９の場合には高分子量化の点で更に好ましい。
【００４２】
なおジハロ芳香族化合物の残存量については通常ガスクロマトグラフ法によって求められる。また、アルカリ金属硫化物及びアルカリ金属水硫化物等の含水スルフィド化剤の残存量は、例えば硝酸銀滴定法によって求めることができる。
【００４３】
本発明の重合反応においては、接液部がチタンあるいはクロムあるいはジルコニウム等でできた重合缶を用い、通常、窒素、ヘリウム、アルゴン等の不活性ガス雰囲気下で行うことが好ましく、特に、経済性及び取扱いの容易さの面から窒素が好ましい。
【００４４】
反応圧力については、使用した原料及び溶媒の種類や量、あるいは反応温度等に依存するので一概に規定できないので、特に制限はない。また、反応液の調整及び重合体の生成反応は一定温度で行う１段反応でも良いし、段階的に温度を上げていく多段階反応でも良いし、あるいは連続的に温度を変化させていく形式の反応でもかまわない。
【００４５】
本発明では、有機極性溶媒中で、ジハロ芳香族化合物と含水スルフィド化剤とを反応させるポリアリーレンスルフィドポリマーの製造において、含水スルフィド化剤がアルカリ金属硫化物とアルカリ金属水硫化物の混合物であり、重合反応終了時の反応系内の水と重合に使用した全該含水スルフィド化剤とのモル比（水／含水スルフィド化剤）が１未満で、重合反応終了時の残存するジハロ芳香族化合物と含水スルフィド化剤とのモル比（ジハロ芳香族化合物／含水スルフィド化剤）が１より小さいことを特徴とするが、前処理工程あるいは後処理工程などの付加的な工程があっても良い。
【００４６】
本発明においては、重合反応終了後の後処理を、常法によって行うことができる。例えば、重合反応終了後、反応混合物をそのまま、あるいは水で、あるいは反応溶媒等の有機溶媒で希釈して、必要に応じて酸あるいは塩基を加えた後、濾別し、更に必要に応じて中和を行い、水洗、濾別および乾燥をすることによって行うことができる。また、別法としては、反応混合物をそのまま、あるいは酸または塩基を加えた後、減圧下または常圧下で加熱して溶媒だけを留去し、ついで缶残固形物に必要に応じて酸あるいは塩基を加え、水あるいはアセトン等のケトン類あるいはメタノール等のアルコール類あるいは反応溶媒等の有機溶媒で１回または２回以上洗浄し、それから必要に応じて中和し、水洗、濾別および乾燥をすることによって行うことができる。なお、上記の洗浄及び濾別操作を行う温度には特に制限はない。また、酸、塩基の代わりに、塩化アンモニウム等の塩などで処理してももちろんかまわない。
【００４７】
単離した重合体は実質的に水等の溶媒が蒸発する温度に加熱して乾燥を行う。乾燥は真空下で行っても良いし、空気中あるいは窒素のような不活性ガス雰囲気下で行っても良い。
【００４８】
本発明により得られる重合体は従来のＰＡＳに比べて高分子量であるので、そのまま各種成形材料等に利用できるが、空気あるいは酸素富化空気中あるいは減圧下で熱処理することにより増粘することが可能であり、必要に応じてこのような増粘操作を行った後、各種成形材料等に利用しても良い。この熱処理温度は処理時間によっても異なるし処理する雰囲気によっても異なるので一概に規定できないが、通常は１８０℃以上で行うことが好ましい。熱処理温度が１８０℃未満では増粘速度が非常に遅く生産性が悪く好ましくない。熱処理は押出機等を用いて重合体の融点以上で、溶融状態で行っても良い。但し、重合体の劣化の可能性あるいは作業性等から、融点プラス１００℃以下で行うことが好ましい。
【００４９】
本発明により得られた重合体は、従来のＰＡＳ同様そのまま射出成形、押出成形、圧縮成形、ブロー成形のごとき各種溶融加工法により、耐熱性、成形加工性、寸法安定性等に優れた成形物にすることができる。しかしながら強度、耐熱性、寸法安定性等の性能をさらに改善するために、本発明の目的を損なわない範囲で各種充填材と組み合わせて使用することも可能である。充填材としては、繊維状充填材、無機充填材等が挙げられる。
【００５０】
また、成形加工の際に添加剤として本発明の目的を逸脱しない範囲で少量の、離型剤、着色剤、耐熱安定剤、紫外線安定剤、発泡剤、防錆剤、難燃剤、滑剤、カップリング剤を含有せしめることができる。更に、同様に下記のごとき合成樹脂及びエラストマーを混合して使用できる。これら合成樹脂としては、ポリエステル、ポリアミド、ポリイミド、ポリエーテルイミド、ポリカーボネート、ポリフェニレンエーテル、ポリスルフォン、ポリエーテルスルフォン、ポリエーテルエーテルケトン、ポリエーテルケトン、ポリアリーレン、ポリエチレン、ポリプロピレン、ポリ四弗化エチレン、ポリ二弗化エチレン、ポリスチレン、ＡＢＳ樹脂、エポキシ樹脂、シリコーン樹脂、フェノール樹脂、ウレタン樹脂、液晶ポリマー等が挙げられ、エラストマーとしては、ポリオレフィン系ゴム、弗素ゴム、シリコーンゴム、等が挙げられる。
【００５１】
本発明の重合体及びその組成物は、従来の方法で得られるＰＰＳ同様耐熱性、寸法安定性等が優れるので、例えば、コネクタ・プリント基板・封止成形品などの電気・電子部品、ランプリフレクター・各種電装部品などの自動車部品、各種建築物や航空機・自動車などの内装用材料、あるいはＯＡ機器部品・カメラ部品・時計部品などの精密部品等の射出成形・圧縮成形品、あるいは繊維・フィルム・シート・パイプなどの押出成形・引抜成形品等として幅広く利用可能である。
【００５２】
【実施例】
以下に本発明を実施例により具体的に説明するが、本発明はこれら実施例にのみ限定されるものではない。
【００５３】
使用原料
１．含水スルフィド化剤
含水フレーク状硫化ナトリウム（以下、Ｎａ２Ｓ・ｘＨ２Ｏと略称する。純度−Ｎａ２Ｓ：５８．９重量％、ＮａＳＨ：１．３重量％）はナガオ（株）製品を使用した。また、含水フレーク状水硫化ナトリウム（以下、ＮａＳＨ・ｙＨ２Ｏと略称する。純度−ＮａＳＨ：７１．２重量％、Ｎａ２Ｓ：２．７重量％）はナガオ（株）製品を使用した。
【００５４】
２．溶媒
Ｎ−メチルピロリドン（以下、ＮＭＰと略称する）はＢＡＳＦジャパン（株）製品を使用した。
【００５５】
３．ジハロ芳香族化合物
ｐ−ジクロロベンゼン（以下、ｐ−ＤＣＢと略称する）は保土谷化学（株）製品を使用した。
【００５６】
４．水
水道水を蒸留した後イオン交換を施したものを使用した。
【００５７】
５．水酸化ナトリウム（以下、ＮａＯＨと略称する）
和光純薬工業（株）試薬を使用した。
【００５８】
６．１，３，５−トリクロロベンゼン（以下、ＴＣＢと略称する）
東京化成（株）試薬を使用した。
【００５９】
物性評価
得られた重合体の溶融粘度（η）は、東洋精機（株）製キャピログラフ１Ｂを用いて測定した（３００℃、剪断速度１００／秒、ノズル孔径１ｍｍ、長さ１０ｍｍ）。
【００６０】
分子量は、（株）センシュー科学製高温ゲルパーミエーションクロマトグラフ（高温ＧＰＣ）ＳＳＣ−７０００を用いて測定した（溶媒：１−クロロナフタレン、温度：２１０℃、検出器：ＵＶ検出器（３６０ｎｍ）、サンプル注入量：２００μｌ（濃度：０．２重量%）。流速１ｍｌ／分）。なお、分子量はポリスチレン換算で算出し、分子量分布のピークトップの値Ｍｐで比較を行った。
【００６１】
実施例１
温度センサー、冷却塔、滴下槽、滴下ポンプ、留出物分離槽を連結した攪拌翼付ステンレス製（チタンライニング）４リットルオートクレーブにｐ−ＤＣＢ ７３５．０ｇ（５．０モル）、ＮＭＰ １９８３ｇ（２０モル）、水 ３６．０ｇ（２．０モル）を室温で仕込み、攪拌しながら窒素雰囲気下で１００℃まで２０分かけて昇温し、系を閉じ、更に２２０℃まで４０分かけて昇温し、その温度で内圧を０．２２ＭＰａにコントロールして、Ｎａ₂Ｓ・ｘＨ₂Ｏ ６００ｇ、ＮａＳＨ・ｙＨ₂Ｏ ９０ｇ、水１７０ｇの混合液（Ｎａ₂Ｓ：４．５６モル、ＮａＳＨ：１．２８モル、水分５０．３ｗｔ％）を３時間かけて滴下した。滴下中は同時に脱水操作を行い、水は系外に除去し、水と共に留出するｐ−ＤＣＢは連続的にオートクレーブに戻した。なお、脱水操作とｐ−ＤＣＢを戻す操作は２４０℃昇温完了まで行い、昇温完了時に系を密閉した。
【００６２】
その後、そのままの温度圧力で１時間保持した後、１時間かけて、内圧を０．１７ＭＰａに下げながら、内温を２４０℃まで昇温し、その温度で１時間保持して反応を終了し、室温まで冷却した。留出液の分析結果は、水が４５０ｇ、ＮＭＰ１８ｇであった。結果的に、反応終了時の反応系内の水分量は全使用含水スルフィド化剤に対して０．１８（モル／モル）であった。なお、ｐ−ＤＣＢについては、留出した全量をオートクレーブ内に戻したので、系外に除去したｐ−ＤＣＢは実質的に０であった。また系外に飛散した硫化水素量は１９ｇであった。従って反応の実質的なモル比〔（仕込みｐ−ＤＣＢ（モル））−（系外に除去したｐ−ＤＣＢ（モル））〕／〔（全使用含水スルフィド化剤（モル））−（系外に除去したＨ_２Ｓ（モル））〕は０．９５であった。得られた反応スラリーを一部サンプリングし、ガスクロマトグラフにより残存ＤＣＢ量を測定し、自動滴定装置を用いた硝酸銀滴定により残存スルフィド化剤量を測定した。その結果は、仕込みのＤＣＢ１モルに対して残存ＤＣＢ：１．５モル％、残存Ｎａ_２Ｓ：３．５モル％、残存ＮａＳＨ：４．４モル％であった。得られた反応スラリー２００ｇを１リットルの水に注いで８０℃で１時間攪拌した後、濾過した。このケーキを再び５００ミリリットルの湯で１時間攪拌、洗浄した後、濾過した。この操作を４回繰り返し、濾過後、熱風乾燥機で１２０℃−１０時間乾燥して白色粉末状のポリマーを得た。得られたポリマーの溶融粘度は１９００ポイズであり、分子量（Ｍｐ）は４２４００であった（精製法−１）。また、また、得られた反応スラリー２００ｇを減圧下（−０．０８ＭＰａ）、１２０℃に加熱することにより反応溶媒を留去し、残査に１リットルの水を注いで８０℃で１時間攪拌した後、濾過した。このケーキを再び５００ミリリットルの湯で１時間攪拌、洗浄した後、濾過した。この操作を３回繰り返し、更に５００ミリリットルの水を加え、２００℃で１時間攪拌後、濾過し、熱風乾燥機で１２０℃−１０時間乾燥して白色粉末状のポリマーを得た。得られたポリマーの溶融粘度は１９４０ポイズであった（精製法−２）。得られた反応スラリー２００ｇにＮＭＰを１００ｇ加え、８０℃で１時間攪拌した後、濾過した。このケーキを再び５００ミリリットルの湯で１時間攪拌、洗浄した後、濾過した。この操作を４回繰り返し、濾過後、熱風乾燥機で１２０℃−１０時間乾燥して白色粉末状のポリマーを得た。得られたポリマーの溶融粘度は２３６０ポイズであった（精製法−３）。結果を表１に示す。
【００６３】
実施例２、３
表１に示すような条件で、実施例１と同様に実施した。結果は表１に示すとおりである。
【００６４】
実施例４
滴下時間を５時間にする以外は実施例１と同様に実施した。結果を表２に示す。
【００６５】
実施例５
昇温前にＴＣＢ０．４５ｇ（０．００２５モル）を追加で仕込む以外は実施例１と同様に実施した。結果を表２に示す。
【００６６】
実施例６
ｐ−ＤＣＢの仕込量を７５０ｇ（５．１モル）として実施例１と同様に反応を行った。ただし、滴下中は留出したｐ−ＤＣＢを連続的に全量オートクレーブに戻し、昇温工程では留出したｐ−ＤＣＢのオートクレーブに戻す量を制御して、オートクレーブ内より１５ｇ系外に抜き出した。結果を表２に示す
【００６７】
比較例１
Ｎａ₂Ｓ・ｘＨ₂Ｏの使用量を６６８ｇ、ＮａＳH・ｙＨ₂Ｏを使用せずその代わりにＮａＯＨを１０ｇ使用し、水を１４０ｇ使用して実施例1と同様に実施した。滴下した混合液の組成はＮａ₂Ｓ：５．２０モル、ＮａＯＨ：０．１０モル、水分５０．３ｗｔ％であった。得られたポリマーは精製法−1で２１０ポイズと実施例に比較して低粘度であった。
【００６８】
比較例２
２２０℃滴下時のコントロールする圧力を０．５５ＭＰａ、２４０℃昇温時のコントロールする圧力を０．９０ＭＰａとする以外は実施例４と同様に実施した。反応終了時の水の量は全使用スルフィド化剤に対して１．１３（モル／モル）であった。得られたポリマーは精製法−１で１２０ポイズと実施例に比較して低粘度であった。
【００６９】
比較例３
使用するＤＣＢの量を７９３．８ｇ（５．４モル）とする以外は実施例１と同様に実施した。残存したモノマーは、仕込みのＤＣＢ１モルに対して残存ＤＣＢ：８．９モル％、残存Ｎａ₂Ｓ：３．２モル％、残存ＮａＳＨ：３．９モル％であった。得られたポリマーは精製法−１で１５０ポイズと実施例に比較して低粘度であった。
【００７０】
【表１】

【００７１】
【表２】

【００７２】
なお、表１及び２中の「反応実質モル比」とは、次式で算出される値を表す。反応実質モル比＝〔（仕込みｐ−ＤＣＢ（モル））−（系外に除去したｐ−ＤＣＢ（モル））〕／〔（全使用含水スルフィド化剤（モル））−（系外に除去したＨ_２Ｓ（モル））〕
【００７３】
【発明の効果】
本発明の製造方法によれば、有機極性溶媒中で、ジハロ芳香族化合物と含水スルフィド化剤とを反応させるポリアリーレンスルフィドポリマーの製造において、含水スルフィド化剤としてアルカリ金属硫化物とアルカリ金属水硫化物の混合物を用い、かつ水分量及びモノマー比を特定範囲にコントロールすることにより、ＰＡＳの高分子量化が達成できる。従って靱性等の力学的強度が向上した製品を、高い生産性で提供できる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a polyarylene sulfide represented by polyphenylene sulfide by reaction of a sulfidizing agent with a dihaloaromatic compound. (Hereinafter, polyarylene sulfide is referred to as PAS, and polyphenylene sulfide is referred to as PPS.) More specifically, the present invention relates to a method for efficiently producing PAS having high molecular weight and excellent stability.
[0002]
[Prior art]
As a method for producing the PAS such as PPS, for example, alkali metal sulfide, particularly sodium sulfide having crystal water (hereinafter, abbreviated as hydrous sodium sulfide) is heated in a polar solvent to contain the hydrous sodium sulfide. There is a method in which water is removed and dichlorobenzene is added thereto to heat polymerize. However, in this method, in order to remove the water contained in hydrous sodium sulfide (including the reaction product of hydrous sodium hydrosulfide and sodium hydroxide), which is one of the raw materials, Due to the removal method, there was a problem that sufficient dehydration was difficult, that is, 1 mol or more of water remained in the system with respect to 1 mol of sodium sulfide, and it was difficult to increase the molecular weight.
[0003]
As a technique for solving the above problems, for example, in the method for producing a polyarylene sulfide polymer in which a dihaloaromatic compound and a sulfidizing agent are reacted under heating in an organic polar solvent, the amount of water in the reaction system is While maintaining a controlled state in the range of 0.05 to 0.5 mol per 1 mol of solvent, a water-containing sulfidizing agent is introduced into the dihaloaromatic compound solution under heating to remove its water content, The first step in which the reaction is carried out or the reaction is carried out after the introduction, and then the second step in which the water content in the system is changed to a range of 0.05 mol or less relative to 1 mol of the solvent and the reaction is continued. It is described that a high molecular weight PPS can be produced by setting the conversion rate in the first step to 60 to 90% and the conversion rate in the second step to 90% or more in the two-stage polymerization method (for example, patents). Reference 1 Irradiation) "
[0004]
[Patent Document 1]
JP-A-8-100064 (pages 2-7)
[0005]
[Problems to be solved by the invention]
However, in the above method, it is possible to obtain a polymer having a relatively high molecular weight, but it is necessary to strictly control the amount of water and the reaction rate in the polymerization system. An object of the present invention is to provide a method for efficiently producing a high molecular weight PAS by solving the above-mentioned problems.
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have obtained the following findings (1), (2), (3), and (4).
(1) It is difficult to efficiently produce a high molecular weight PAS only by simply controlling the amount of water in the polymerization system. (2) Side reactions can be suppressed by using a mixture of alkali metal sulfide and alkali metal hydrosulfide as a sulfidizing agent. (3) The reaction rate can be controlled by controlling the contents of the sulfidizing agent remaining at the end of the reaction and the water content in the reaction system remaining at the end of the reaction within a specific range. (4) A high molecular weight PAS can be obtained efficiently by setting the ratio of the dihaloaromatic compound remaining at the end of the reaction to the sulfidizing agent within a specific range.
[0006]
  The present invention has been made based on these technical findings. That is, the present invention provides a dihaloaromatic compound and an organic polar solvent.Hydrous sulfiding agent with water of crystallizationA process for producing polyarylene sulfide, wherein
1)Water contentThe sulfiding agent is a mixture of alkali metal sulfide and alkali metal hydrosulfide,
2)A method of reacting a mixture containing a heated organic polar solvent and a dihaloaromatic compound while introducing the water-containing sulfiding agent,
In addition, the introduction rate of the water-containing sulfiding agent is adjusted from the reaction mixture so that the water in the reaction system is less than 1 mol with respect to 1 mol of all the water-containing sulfiding agent used in the polymerization. Adjust and control to be removed,The molar ratio of water in the reaction system at the end of the polymerization reaction to the total sulfidizing agent used in the polymerization (water /Water contentThe sulfiding agent) is controlled to be less than 1,
3) The dihaloaromatic compound remaining at the end of the polymerization reaction andWater contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentA process for producing a polyarylene sulfide, wherein the sulfiding agent is controlled to be less than 1.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present invention will be specifically described.
Used in the present inventionWater contentThe sulfiding agent is a mixture of alkali metal sulfide and alkali metal hydrosulfide. Examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. Among these, sodium sulfide and potassium sulfide are preferable, and sodium sulfide is particularly preferable. These alkali metal sulfides may be used alone or in combination of two or more.Also,These alkali metal sulfides can be obtained by reacting an alkali metal hydrosulfide with an alkali metal hydroxide, or by reacting hydrogen sulfide with an alkali metal hydroxide. You may use the thing obtained.
[0008]
  Examples of the alkali metal hydrosulfide used in the present invention include lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and the like. Two or more kinds may be mixed and used.theseOf these, sodium hydrosulfide and potassium hydrosulfide are preferable, and sodium hydrosulfide is particularly preferable. These alkali metal hydrosulfides are either alkali metal hydrosulfides themselves or those obtained in advance by reacting hydrogen sulfide with alkali metal hydroxides. You may use what is obtained also by making it react with an oxide. The alkali metal sulfide and the alkali metal hydrosulfide have 1 mol or more of crystal water with respect to 1 mol of sulfur atom.It is.In the following, those having 1 mol or more of water of crystallization with respect to 1 mol of sulfur atom in alkali metal sulfide and alkali metal hydrosulfide were used.ThingsThis is referred to as a hydrous sulfiding agent.
[0009]
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide and the like. These may be used alone or in combination of two or more. May be used in combination. Among the alkali metal hydroxides, lithium hydroxide, sodium hydroxide and potassium hydroxide are preferable, and sodium hydroxide is particularly preferable.
[0010]
  Used in the present inventionWater contentThe sulfidizing agent is a mixture of an alkali metal sulfide and an alkali metal hydrosulfide. As described above, the sulfidizing agent may be obtained by reacting an alkali metal hydroxide with an excess of an alkali metal hydrosulfide. You may obtain by making a metal hydroxide and excess hydrogen sulfide react. Moreover, you may obtain by making an alkali metal sulfide and hydrogen sulfide react.
[0011]
In the mixture of alkali metal sulfide and alkali metal hydrosulfide, the ratio of alkali metal sulfide to alkali metal hydrosulfide is not particularly limited, but alkali metal hydrosulfide is 0 per 1 mol of alkali metal sulfide. The range of 0.02 to 2 mol is preferable, and the range of 0.04 to 1 mol is more preferable. When the amount falls within this range, a higher molecular weight polymer can be obtained.
[0012]
  The dihaloaromatic compound used in the present invention has an aromatic nucleus and two halo substituents on the nucleus, and is a mixture of an alkali metal sulfide and an alkali metal hydrosulfide.Water contentThe polymer is not particularly limited as long as it can be polymerized through a dehalogenation / sulfurization reaction with a sulfidizing agent. Therefore, the aromatic nucleus may have various substituents that do not inhibit this dehalogenation / sulfurization reaction, in addition to the case of consisting only of aromatic hydrocarbons.
[0013]
Examples of the dihaloaromatic compound include compounds represented by the following general formulas (1) to (4).
[Chemical 1]

[0014]
In the general formulas (1) to (4), X represents a halogen atom, Y represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, or 6 to 18 carbon atoms. An aryl group, a carboxyl group, an alkoxycarbonyl group having 1 to 18 carbon atoms, a sodium carboxylate group, a cyano group, an amino group, or a nitro group. X is preferably chlorine or bromine.
[0015]
Moreover, V in General formula (4) represents the bivalent coupling group represented by following Structural formula (5)-(10).
[Chemical formula 2]

(In the formula, R ′ and R ″ each independently represent a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.)
[0016]
In general formula (1), m represents 2 and n represents an integer of 0 to 4. Moreover, a in general formula (2) represents 2, and b represents the integer of 0-6. In the general formula (3), c represents an integer of 0 to 2, d represents 0 to 2, e represents an integer of 0 to 3, f represents an integer of 0 to 2, and c and d satisfy c + d = 2. In general formula (4), g is 0 to 2, h is 0 to 2, and i and j are integers satisfying 0 ≦ i and j ≦ 2.
[0017]
Specific examples of the dihaloaromatic compounds represented by the general formulas (1) to (4) include p-dihalobenzene, m-dihalobenzene, o-dihalobenzene, 2,5-dihalotoluene, 1,4-dihalonaphthalene, 1- Methoxy-2,5-dihalobenzene, 4,4′-dihalobiphenyl, 3,5-dihalobenzoic acid, 2,4-dihalobenzoic acid, 2,5-dihalonitrobenzene, 2,4-dihalonitrobenzene, 2 , 4-dihaloanisole, 2,5-dihaloaniline, 3,5-dihaloaniline, p, p'-dihalodiphenyl ether, 4,4'-dihalobenzophenone, 4,4'-dihalodiphenyl sulfone, 4,4 '-Dihalodiphenyl sulfoxide, 4,4'-dihalodiphenyl sulfide, etc. Among them, p-dihalobenzene, m-dihalobenzene, 4, '-Dihalobenzophenone and 4,4'-dihalodiphenylsulfone are preferred, and p-dichlorobenzene, m-dichlorobenzene, 4,4'-dichlorobenzophenone and 4,4'-dichlorodiphenylsulfone are particularly preferred. used.
[0018]
A copolymer containing two or more kinds of different reaction units can be obtained by appropriately selecting and combining dihaloaromatic compounds, and the combination is not particularly limited. It is preferable to use p-dichlorobenzene in combination with 4,4'-dichlorobenzophenone or 4,4'-dichlorophenylsulfone because PAS having various physical properties can be obtained. Polymerization using p-dihalobenzene in the dihaloaromatic compound in an amount of 70 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more is particularly preferable because PAS having various physical properties can be obtained. In addition, PPS, which is a polymer containing only dihalobenzene, is excellent in various physical properties. Among them, use of dichlorobenzene is more preferable in terms of productivity.
[0019]
The PAS according to the present invention is a polymer of the above-mentioned dihaloaromatic compound, but it may be used in combination with a monohalo compound in order to form the end of the resulting polymer or to adjust the polymerization reaction or molecular weight. In order to form a polymer, it is also possible to use a polyhalo compound of trihalo or higher in combination. When these monohalo or polyhalo compounds are used in combination, for example, if dihalobenzene is used in combination with a slight amount of trichlorobenzene, a branched phenylene sulfide polymer can be obtained, and three or more halogens such as trichlorobenzene can be obtained. Use of a polyhalo compound having an atom as a substituent is useful in terms of increasing the viscosity of the resulting polymer. The amount of the monohalo compound or the polyhalo compound having 3 or more halogen atoms as a substituent varies depending on the purpose or reaction conditions, and cannot be specified unconditionally, but is preferably 0.1 per mol of the dihaloaromatic compound. The mol% or less, more preferably 0.06 mol% or less. When the amount of the polyhalo compound having three or more halogen atoms represented by trichlorobenzene as a substituent is within the above range, it is preferable because the viscosity of the resulting polymer can be increased with almost no loss. Note that the monohalo compound and the polyhalo compound having three or more halogen atoms as substituents are not necessarily aromatic compounds.
[0020]
The organic polar solvent used in the polymerization reaction of the present invention is an organic polar solvent having no active hydrogen, that is, an aprotic type organic polar solvent.
[0021]
  The organic polar solvent does not inhibit the polymerization reaction, and is a raw material dihaloaromatic compound and S^2-giveWater contentThe sulfidizing agent is not particularly limited as long as it has a solubility enough to dissolve the sulfiding agent at a concentration necessary for the reaction. Among these, this solvent is usually a polar solvent having a nitrogen atom, an oxygen atom, or a sulfur atom. Furthermore, it is desirable that this solvent is not capable of participating in the same dehalogenation / sulfurization reaction as the raw material dihaloaromatic compound. Thus, for example, it is preferably not a haloaromatic hydrocarbon.
[0022]
Since the organic polar solvent is for providing a controlled small amount of water to the polymerization reaction, it is desirable that the water as a solute can be solvated.
[0023]
Further, as apparent from the production method of the present invention, the boiling point of the organic polar solvent is desirably higher than that of water. Examples of satisfying the aforementioned conditions include (1) Amides such as hexamethylphosphoric triamide (HMPA), N-methylpyrrolidone (NMP), N-cyclohexylpyrrolidone (NCP), N-methylcaprolactam, Tetramethylurea (TMU), dimethylformamide (DMF), dimethylacetamide (DMA), etc. (2) Etherified polyethylene glycols such as polyethylene glycol dialkyl ether (degree of polymerization up to about 2000, alkyl group is C₁~ C₂₀(3) sulfoxides such as tetramethylene sulfoxide and dimethyl sulfoxide (DMSO). Among the solvents, N-methylcaprolactam and NMP are particularly preferable because of high chemical stability.
[0024]
  The amount of the organic polar solvent used varies depending on the type of solvent used and the amount of water with respect to the solvent in the system, but maintains the viscosity of the reaction system that allows a uniform polymerization reaction, and maintains a certain degree of productivity. To be used for polymerizationWater contentA range of 1.0 to 8.0 moles per mole of sulfur atoms in the sulfiding agent is preferred. In addition, considering the productivity further, it is used for polymerization.Water contentThe range of 1.0 to 6.0 moles per mole of sulfur atoms in the sulfidizing agent is preferred, and a more preferred amount of solvent used is used for the polymerization.Water contentThe amount is 1.2 to 5.0 moles per mole of sulfur atom in the sulfidizing agent.
[0025]
The water for adjusting the water content in the polymerization system or the water content of the water-containing sulfidizing agent is not required to contain water that inhibits the reaction. For this reason, distilled water, ion-exchanged water, etc. Water excluding cations is preferred.
[0026]
  The moisture present in the polymerization reaction of the present invention is preferably as small as possible in order to avoid the simultaneous occurrence of a hydrolysis reaction or the like. On the other hand, when the polymerization reaction is completely anhydrous, there is a problem that the reaction rate is remarkably slow. Therefore, the amount of water to be present in the reaction system in the polymerization reaction of the present invention is the same as that used for the polymerization.Water contentIt must be less than 1 mole at the end of the polymerization reaction, per mole of sulfiding agent. In addition, from the point that the reaction proceeds smoothly, the used for the polymerization.Water contentIt is preferable to make it exist 0.02 mol or more with respect to 1 mol of sulfidizing agents. Among these, the used for polymerizationWater contentThe range of 0.03-0.60 is preferable with respect to 1 mol of sulfiding agents, and the range of 0.05-0.40 is particularly preferable. When the above range is satisfied, both controllability of reaction rate control and high molecular weight can be easily achieved.
[0027]
  In the present invention, in an organic polar solvent, a dihaloaromatic compound andWater contentIn the production of polyarylene sulfide in which a sulfidizing agent is reacted,Water contentThe sulfiding agent is a mixture of an alkali metal sulfide and an alkali metal hydrosulfide, and the water in the reaction system at the end of the polymerization reaction and allWater contentMolar ratio with sulfiding agent (water /Water contentA disulfoaromatic compound remaining at the end of the polymerization reaction,Water contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentCharacterized in that the sulfiding agent) is less than 1.Do.
[0028]
  Water contentSulfiding agentUseIn order to satisfy the characteristics of the production method of the present invention, dehydration is required. In the present invention, dehydration and polymerization may be performed simultaneously, or dehydration and polymerization may be performed separately, or polymerization may be performed. You may perform dehydration suitably, performing.
[0029]
As a method for performing dehydration and polymerization at the same time, an organic polar solvent (organic polarity) is used, for example, at a temperature at which the polymerization reaction can substantially proceed, 200 to 300 ° C, preferably 210 to 280 ° C, more preferably 215 to 260 ° C. The water-containing sulfidizing agent is heated at a rate at which the amount of water in the reaction system can be controlled within the above range. After introducing into the mixture to remove excess water out of the system and controlling the amount of water in the reaction system within the above range, it is further heated to a temperature of 200 to 300 ° C., preferably 210 to 280 ° C. for 40 hours. Hereinafter, a method of performing the polymerization reaction by heating preferably 0.5 to 20 hours, more preferably 1 to 10 hours may be used.
[0030]
  In addition, as a method of performing dehydration and polymerization separately, for example, a temperature at which the polymerization reaction hardly proceeds, that is, 120 to 200 ° C., preferably 150 to 190 ° C. is set to an organic polar solvent (0.5 mol relative to the organic polar solvent). Keep the mixture of dihaloaromatic compounds and water content in the reaction systemWater contentAt a rate that can be controlled to less than 1 mole per mole of sulfiding agentWater contentA sulfidizing agent is introduced into the mixture to remove excess water from the system, and the water content in the reaction system is reduced.Water contentAfter controlling to less than 1 mole with respect to 1 mole of the sulfiding agent, the temperature at which the polymerization reaction substantially proceeds in the mixture of the prepared organic polar solvent, dihaloaromatic compound and hydrous sulfiding agent, ie, 200 to 300 ° C. The polymerization reaction may be performed by heating to a temperature of 210 to 280 ° C., preferably 40 hours or less, preferably 0.5 to 20 hours, more preferably 1 to 10 hours.
[0031]
  In addition, as a method of performing dehydration appropriately while performing polymerization, for example, the following method may be used.Can be mentioned.
[0032]
  ▲1▼ An organic polar solvent (which may contain 0.5 mol or less of water with respect to the organic polar solvent) and a dihaloaromatic compound at a temperature at which the polymerization reaction hardly proceeds, that is, 120 to 200 ° C., preferably 150 to 190 ° C. At a speed that can control the amount of water in the reaction system.Water contentA sulfidizing agent is introduced into the mixture to remove excess water from the system, and the water content in the reaction system is adjusted toWater contentAfter controlling to less than 1 mole with respect to 1 mole of the sulfiding agent, the temperature at which the polymerization reaction substantially proceeds in the mixture of the prepared organic polar solvent, dihaloaromatic compound and hydrous sulfiding agent, ie, 200 to 300 ° C. The polymerization reaction is performed by heating to a temperature of 210 to 280 ° C., preferably for 0.1 to 40 hours, preferably 0.5 to 20 hours, more preferably 1 to 10 hours. In the meantime, a polymerization method in which the moisture content in the system is further reduced by removing water in the system continuously or temporarily or intermittently as necessary.
[0033]
  ▲2▼ A temperature at which the polymerization reaction can proceed, 200 to 300 ° C., preferably 210 to 280 ° C., more preferably 215 to 260 ° C. An organic polar solvent (containing 0.5 mol or less of water relative to the organic polar solvent) And the dihaloaromatic compound mixture is heated, and a water-containing sulfidizing agent is introduced into the mixture at a rate at which the amount of water in the reaction system can be controlled to remove excess water from the system. The amount of water in the reaction systemWater contentAfter controlling to less than 1 mole per mole of sulfidizing agent, it is further heated to a temperature of 200 to 300 ° C., preferably 210 to 280 ° C. for 40 hours or less, preferably 0.5 to 20 hours, More preferably, the polymerization reaction is carried out by heating for 1 to 10 hours. During the polymerization reaction, the water content in the system is removed continuously or temporarily or intermittently to further reduce the water content. Method.
[0034]
  Among the above polymerization methods, from the viewpoint of productivity and the like, a method of appropriately dehydrating while performing polymerization is preferable. Among these, the mixture of the organic polar solvent and the dihaloaromatic compound is heated to a temperature at which the polymerization reaction can substantially proceed, and the water-containing sulfidizing agent is introduced into the mixture at a rate at which the amount of water in the reaction system can be controlled. After removing excess water outside the system and controlling the amount of water in the reaction system, further polymerization reaction is performed, and during the polymerization reaction, it is continuously or temporarily or intermittently as necessary. In particular, a polymerization method in which moisture in the system is removed to further reduce the amount of water is preferable. In particular, the amount of water in the reaction system throughout the polymerization process isWater contentThe polymerization method (above ▲2▼) is most preferred.
[0035]
The rate of introducing the water-containing sulfidizing agent is particularly limited as long as it can remove excess water from the system so that the amount of water in the reaction system can be controlled within the target range with respect to 1 mol of the organic polar solvent. There is no. The introduction time varies depending on the moisture content to be controlled, the temperature at the time of introduction, the moisture content of the water-containing sulfidizing agent and the like, and thus cannot be defined unconditionally. However, the water-containing sulfidizing agent is used for 0.1 to 20 hours, preferably 0.5 It is preferable to introduce over 10 hours. Within this time, it is easy to control the water content or temperature of the reaction system, and the productivity is good.
[0036]
In addition, although it depends on the amount of water that controls the temperature at which the hydrous sulfidizing agent is introduced, the rate at which it is introduced, the water content of the hydrous sulfidizing agent, or the type of reaction, it cannot be defined unconditionally, but dehydration and polymerization are performed separately If it is carried out, it may be introduced at 120 to 200 ° C., preferably 150 to 190 ° C. If dehydration and polymerization are performed simultaneously, the introduction may be performed at a temperature of 200 to 300 ° C, preferably 210 to 280 ° C, more preferably 215 to 260 ° C.
[0037]
The polymerization reaction is performed by heating to a temperature of 200 to 300 ° C., preferably 210 to 280 ° C., and heating for 0.1 to 40 hours, preferably 0.5 to 20 hours, more preferably 1 to 10 hours. preferable. Within this range, the reaction proceeds smoothly.
[0038]
The method for removing water at the time of polymerization can be easily performed by controlling the temperature and pressure of the reaction system. That is, the temperature and pressure to be controlled can be easily estimated from the vapor pressure curves of water, solvent, and dihaloaromatic compound, and the desired moisture content in the system can be obtained by controlling the temperature and pressure.
[0039]
  Dihaloaromatic compounds used in the production method of the present invention andWater contentThe amount of sulfidizing agent used is the amount of dihaloaromatic compound remaining at the end of the polymerization reaction.Water contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentIf the sulfiding agent is less than 1, there is no particular limitation. For example, dihaloaromatic compounds andWater contentExamples of the method for adding the sulfidizing agent include the following methods (a) and (b).
(A) Remaining dihaloaromatic compound remaining at the end of the polymerization reaction in advanceWater contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentThe dihaloaromatic compound and the sulfiding agent) to be less than 1.Water contentA sulfidizing agent may be charged and reacted. Further, (b) the remaining dihaloaromatic compound at the end of the polymerization reaction and the remainingWater contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentA dihaloaromatic compound and a sulfiding agent)Water contentAfter charging the sulfidizing agent, the dihaloaromatic compound is removed from the system during the polymerization, and the dihaloaromatic compound remaining at the end of the polymerization reaction remains.Water contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentThe sulfiding agent may be adjusted to be less than 1. Among these, (a) is preferable.
[0040]
  In any case of the method (a) or (b), it remains with the dihaloaromatic compound remaining at the end of the polymerization reaction.Water contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentIt is essential that the sulfidizing agent is less than 1, and if it is 1 or more, the high molecular weight of the polymer that is the object of the present invention cannot be achieved, which is not preferable. However, if it is too small, the molecular weight may decrease due to the decomposition reaction of the polymer, so 0.05 or more is preferable. Among these, the dihaloaromatic compound remaining at the end of the polymerization reaction and remainingWater contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentA range of 0.1 to 0.5 is particularly preferred for the sulfiding agent. If this range is satisfied, higher molecular weight can be achieved without causing simultaneous decomposition reactions.
[0041]
  Therefore, in either case of the method (a) or (b), [(totally used dihaloaromatic compound (mol))-(dihaloaromatic compound removed outside the system (mol))] and [(totally usedWater contentThe ratio of the sulfidizing agent (mole))-(sulfur content removed out of the system (mole))] is greater than 0.90 and less than 1 gives a polymer having excellent physical properties, that is, a polymer having a higher molecular weight. Is preferable. When the above range is satisfied, it is preferable because the preferable range of the remaining monomer ratio is easily satisfied. Moreover, when the said range is 0.92-0.99, it is still more preferable at the point of high molecular weight.
[0042]
  The residual amount of dihaloaromatic compound is usually determined by gas chromatography. In addition, alkali metal sulfide and alkali metal hydrosulfideWater contentThe remaining amount of the sulfidizing agent can be determined, for example, by a silver nitrate titration method.
[0043]
The polymerization reaction of the present invention is preferably carried out in an inert gas atmosphere such as nitrogen, helium, argon, etc. using a polymerization can whose wetted part is made of titanium, chromium, zirconium or the like. Nitrogen is preferable from the viewpoint of easy handling.
[0044]
The reaction pressure is not particularly limited because it depends on the type and amount of the raw material and solvent used, or the reaction temperature and cannot be defined unconditionally. Further, the reaction liquid preparation and the polymer formation reaction may be a one-stage reaction performed at a constant temperature, a multi-stage reaction in which the temperature is raised stepwise, or a form in which the temperature is continuously changed. The reaction may be
[0045]
  In the present invention, in an organic polar solvent, a dihaloaromatic compound andWater contentIn the production of a polyarylene sulfide polymer that is reacted with a sulfidizing agent,Water contentThe sulfiding agent is a mixture of an alkali metal sulfide and an alkali metal hydrosulfide, and the water in the reaction system at the end of the polymerization reaction and allWater contentMolar ratio with sulfiding agent (water /Water contentA disulfoaromatic compound remaining at the end of the polymerization reaction,Water contentMolar ratio with sulfiding agent (dihaloaromatic compound /Water contentThe sulfiding agent) is smaller than 1, but there may be additional steps such as a pretreatment step or a posttreatment step.
[0046]
In the present invention, the post-treatment after completion of the polymerization reaction can be performed by a conventional method. For example, after completion of the polymerization reaction, the reaction mixture is left as it is or diluted with water or an organic solvent such as a reaction solvent, and an acid or a base is added as necessary, followed by filtration, and further, if necessary It can be done by performing summing, washing with water, filtering off and drying. As another method, the reaction mixture is left as it is or after addition of an acid or base, and then heated under reduced pressure or normal pressure to distill off only the solvent, and then the residual solid can be acid or base as necessary. Wash with water or ketones such as acetone, alcohols such as methanol, or organic solvents such as reaction solvent, and then neutralize, wash, filter, and dry as necessary. Can be done. In addition, there is no restriction | limiting in particular in the temperature which performs said washing | cleaning and filtration operation. Of course, it may be treated with a salt such as ammonium chloride instead of acid or base.
[0047]
The isolated polymer is dried by heating to a temperature at which a solvent such as water substantially evaporates. Drying may be performed under vacuum, or may be performed in air or in an inert gas atmosphere such as nitrogen.
[0048]
Since the polymer obtained by the present invention has a higher molecular weight than conventional PAS, it can be used as it is for various molding materials, but it can be thickened by heat treatment in air or oxygen-enriched air or under reduced pressure. It is possible, and after performing such a thickening operation as necessary, it may be used for various molding materials. This heat treatment temperature varies depending on the treatment time and also varies depending on the atmosphere to be treated, so it cannot be specified unconditionally. If the heat treatment temperature is less than 180 ° C., the speed of thickening is very slow and the productivity is poor, which is not preferable. The heat treatment may be performed in a molten state using an extruder or the like above the melting point of the polymer. However, it is preferable to carry out at melting | fusing point plus 100 degrees C or less from the possibility of deterioration of a polymer or workability | operativity.
[0049]
The polymer obtained by the present invention is a molded product excellent in heat resistance, molding processability, dimensional stability, etc. by various melt processing methods such as injection molding, extrusion molding, compression molding and blow molding as in the case of conventional PAS. Can be. However, in order to further improve performance such as strength, heat resistance, and dimensional stability, it can be used in combination with various fillers as long as the object of the present invention is not impaired. Examples of the filler include a fibrous filler and an inorganic filler.
[0050]
In addition, a small amount of a release agent, a colorant, a heat stabilizer, an ultraviolet stabilizer, a foaming agent, a rust inhibitor, a flame retardant, a lubricant, a cup as long as they do not deviate from the object of the present invention as additives during molding processing A ring agent can be contained. Furthermore, the following synthetic resins and elastomers can also be mixed and used. These synthetic resins include polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone, polyetherketone, polyarylene, polyethylene, polypropylene, polytetrafluoroethylene, Examples thereof include poly (difluoroethylene), polystyrene, ABS resin, epoxy resin, silicone resin, phenol resin, urethane resin, liquid crystal polymer, and the like, and examples of the elastomer include polyolefin rubber, fluorine rubber, silicone rubber, and the like.
[0051]
Since the polymer of the present invention and the composition thereof are excellent in heat resistance and dimensional stability, etc., as in PPS obtained by a conventional method, for example, electrical / electronic parts such as connectors, printed boards, sealing molded products, lamp reflectors, etc.・ Automotive parts such as various electrical parts, interior materials such as various buildings, aircraft and automobiles, or injection molding and compression molded parts such as precision parts such as OA equipment parts, camera parts and watch parts, or fibers, films, etc. It can be widely used as extrusion and pultrusion products such as sheets and pipes.
[0052]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited only to these examples.
[0053]
  Raw materials used
1.Water contentSulfiding agent
Nagao Co., Ltd. product was used as the hydrated flaky sodium sulfide (hereinafter abbreviated as Na 2 S · xH 2 O. Purity—Na 2 S: 58.9 wt%, NaSH: 1.3 wt%). Also, Nagao Co., Ltd. product was used for hydrous flaky sodium hydrosulfide (hereinafter abbreviated as NaSH · yH 2 O. Purity—NaSH: 71.2 wt%, Na 2 S: 2.7 wt%).
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2. solvent
NSF-pyrrolidone (hereinafter abbreviated as NMP) was a product of BASF Japan.
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3. Dihaloaromatic compounds
As p-dichlorobenzene (hereinafter abbreviated as p-DCB), a product from Hodogaya Chemical Co., Ltd. was used.
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4). water
The tap water was distilled and used after ion exchange.
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5. Sodium hydroxide (hereinafter abbreviated as NaOH)
Wako Pure Chemical Industries, Ltd. reagent was used.
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6.1,3,5-trichlorobenzene (hereinafter abbreviated as TCB)
Tokyo Chemical Co., Ltd. reagent was used.
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Evaluation of the physical properties
The melt viscosity (η) of the obtained polymer was measured using a Capillograph 1B manufactured by Toyo Seiki Co., Ltd. (300 ° C., shear rate 100 / sec, nozzle hole diameter 1 mm, length 10 mm).
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Molecular weight was measured using Senshu Scientific high temperature gel permeation chromatograph (high temperature GPC) SSC-7000 (solvent: 1-chloronaphthalene, temperature: 210 ° C., detector: UV detector (360 nm), Sample injection volume: 200 μl (concentration: 0.2 wt%), flow rate 1 ml / min). The molecular weight was calculated in terms of polystyrene, and the comparison was performed using the peak top value Mp of the molecular weight distribution.
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Example 1
A stainless steel (titanium lining) 4 liter autoclave with stirring blades connected to a temperature sensor, a cooling tower, a dropping tank, a dropping pump, and a distillate separation tank, p-DCB 735.0 g (5.0 mol), NMP 1983 g (20 Mol) and 36.0 g (2.0 mol) of water at room temperature, the temperature was raised to 100 ° C over 20 minutes under stirring in a nitrogen atmosphere, the system was closed, and the temperature was further raised to 220 ° C over 40 minutes. At that temperature, the internal pressure is controlled to 0.22 MPa, and Na₂S xH₂O 600g, NaSH · yH₂Mixed solution of 90 g of O and 170 g of water (Na₂S: 4.56 mol, NaSH: 1.28 mol, moisture 50.3 wt%) was added dropwise over 3 hours. During the dropping, dehydration was performed simultaneously, water was removed from the system, and p-DCB distilled together with water was continuously returned to the autoclave. The dehydration operation and the operation for returning the p-DCB were performed until the temperature increase at 240 ° C. was completed, and the system was sealed when the temperature increase was completed.
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  Then, after maintaining for 1 hour at the same temperature and pressure, while lowering the internal pressure to 0.17 MPa over 1 hour, the internal temperature was raised to 240 ° C. and held at that temperature for 1 hour to complete the reaction, Cooled to room temperature. The analysis results of the distillate were 450 g of water and 18 g of NMP. As a result, the amount of water in the reaction system at the end of the reaction is completely used.Water contentIt was 0.18 (mol / mol) with respect to the sulfidizing agent. In addition, about p-DCB, since the whole distilled amount was returned in the autoclave, p-DCB removed out of the system was substantially zero. The amount of hydrogen sulfide scattered outside the system was 19 g. Accordingly, the substantial molar ratio of the reaction [(charged p-DCB (mol))-(p-DCB (mol) removed outside the system)]] / [(total useWater contentSulfiding agent (mole))-(H removed outside system)₂S (mol))] was 0.95. A part of the obtained reaction slurry was sampled, the amount of residual DCB was measured by a gas chromatograph, and the amount of residual sulfiding agent was measured by silver nitrate titration using an automatic titrator. The results are as follows: Residual DCB: 1.5 mol%, residual Na₂S: 3.5 mol% and residual NaSH: 4.4 mol%. 200 g of the resulting reaction slurry was poured into 1 liter of water, stirred at 80 ° C. for 1 hour, and then filtered. The cake was again stirred and washed with 500 ml of hot water for 1 hour and then filtered. This operation was repeated 4 times, and after filtration, dried in a hot air dryer at 120 ° C. for 10 hours to obtain a white powdery polymer. The resulting polymer had a melt viscosity of 1900 poise and a molecular weight (Mp) of 42400 (Purification Method-1). Also, 200 g of the resulting reaction slurry was heated to 120 ° C. under reduced pressure (−0.08 MPa) to distill off the reaction solvent, and 1 liter of water was poured into the residue and stirred at 80 ° C. for 1 hour. And then filtered. The cake was again stirred and washed with 500 ml of hot water for 1 hour and then filtered. This operation was repeated three times, 500 ml of water was further added, the mixture was stirred at 200 ° C. for 1 hour, filtered, and dried with a hot air dryer at 120 ° C. for 10 hours to obtain a white powdery polymer. The melt viscosity of the obtained polymer was 1940 poise (Purification Method-2). 100 g of NMP was added to 200 g of the obtained reaction slurry, stirred at 80 ° C. for 1 hour, and then filtered. The cake was again stirred and washed with 500 ml of hot water for 1 hour and then filtered. This operation was repeated 4 times, and after filtration, dried in a hot air dryer at 120 ° C. for 10 hours to obtain a white powdery polymer. The melt viscosity of the obtained polymer was 2360 poise (Purification Method-3). The results are shown in Table 1.
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Examples 2 and 3
The same operation as in Example 1 was performed under the conditions shown in Table 1. The results are as shown in Table 1.
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Example 4
The same operation as in Example 1 was performed except that the dropping time was 5 hours. The results are shown in Table 2.
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Example 5
The same operation as in Example 1 was conducted except that 0.45 g (0.0025 mol) of TCB was additionally charged before the temperature was raised. The results are shown in Table 2.
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Example 6
The reaction was carried out in the same manner as in Example 1 except that the amount of p-DCB charged was 750 g (5.1 mol). However, during the dropwise addition, the entire amount of p-DCB distilled was returned to the autoclave, and the amount of p-DCB returned to the autoclave was controlled in the temperature raising step, and 15 g was extracted from the autoclave outside the system. The results are shown in Table 2.
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Comparative Example 1
Na₂S xH₂The amount of O used is 668 g, NaSH · yH₂This was carried out in the same manner as in Example 1 except that 10 g of NaOH was used instead of O and 140 g of water was used. The composition of the dropped liquid mixture is Na₂S: 5.20 mol, NaOH: 0.10 mol, moisture 50.3 wt%. The obtained polymer had a viscosity of 210 poise in the purification method-1 and a low viscosity compared to the examples.
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Comparative Example 2
The same operation as in Example 4 was performed except that the pressure controlled at the time of dropping at 220 ° C. was 0.55 MPa, and the pressure controlled at the time of heating at 240 ° C. was 0.90 MPa. The amount of water at the end of the reaction was 1.13 (mol / mol) based on the total sulfidizing agent used. The obtained polymer had a viscosity of 120 poise in the purification method-1 and a low viscosity compared to the examples.
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Comparative Example 3
The same procedure as in Example 1 was performed except that the amount of DCB used was 793.8 g (5.4 mol). The remaining monomer was 8.9 mol% of residual DCB with respect to 1 mol of charged DCB, residual Na.₂S: 3.2 mol% and residual NaSH: 3.9 mol%. The obtained polymer had a viscosity of 150 poise in the refining method-1 and a low viscosity compared to the examples.
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[Table 1]

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[Table 2]

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  The “reaction substantial molar ratio” in Tables 1 and 2 represents a value calculated by the following formula. Reaction real molar ratio = [(charged p-DCB (mol)) − (p-DCB removed outside the system (mol))] / [(all useWater contentSulfiding agent (mole))-(H removed outside system)₂S (mol))]
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【The invention's effect】
  According to the production method of the present invention, in an organic polar solvent, a dihaloaromatic compound andWater contentIn the production of a polyarylene sulfide polymer that is reacted with a sulfidizing agent,Water contentBy using a mixture of an alkali metal sulfide and an alkali metal hydrosulfide as a sulfidizing agent and controlling the water content and the monomer ratio within a specific range, it is possible to achieve high molecular weight of PAS. Therefore, a product with improved mechanical strength such as toughness can be provided with high productivity.

Claims (5)

A method for producing polyarylene sulfide, comprising reacting a dihaloaromatic compound and a hydrous sulfiding agent having crystal water in an organic polar solvent,
1) The hydrous sulfiding agent is a mixture of alkali metal sulfide and alkali metal hydrosulfide,
2) A method of reacting a mixture containing a heated organic polar solvent and a dihaloaromatic compound while introducing the water-containing sulfiding agent,
In addition, the introduction rate of the water-containing sulfiding agent is adjusted from the reaction mixture so that the water in the reaction system is less than 1 mol with respect to 1 mol of all the water-containing sulfiding agent used in the polymerization. Adjust and control to be removed so that the molar ratio of water in the reaction system at the end of the polymerization reaction to the total hydrous sulfiding agent used in the polymerization (water / hydrous sulfiding agent) is less than 1. And
3) A polyarylene, wherein the molar ratio of the dihaloaromatic compound remaining at the end of the polymerization reaction to the water-containing sulfiding agent (dihaloaromatic compound / water-containing sulfiding agent) is controlled to be less than 1. A method for producing sulfide. Mixing ratio of the alkali metal sulfide and an alkali metal hydrosulfide in the water-containing sulfiding agent, according to claim 1 an alkali metal hydrosulfide is in the range of 0.04 to 1 mole of the alkali metal sulfide 1 mole A process for producing the polyarylene sulfide as described. [(All-used dihaloaromatic compound (mol))-(Dihaloaromatic compound removed outside system (mol))] and [(All-use hydrous sulfidizing agent (mol))-(Sulfur content removed outside system) The method for producing a polyarylene sulfide according to claim 1 or 2 , wherein the ratio of (mol))] is in the range of 0.92 to 0.99. The method for producing polyarylene sulfide according to any one of claims 1 to 3 , wherein the polyarylene sulfide is polyphenylene sulfide. The method for producing polyarylene sulfide according to any one of claims 1 to 4 , wherein the polyarylene sulfide is polyphenylene sulfide containing a branched structure of 0.1 mol% or less.