JP2004315764A - Method for producing aromatic polyether - Google Patents

Abstract

［式中、Ｙ、Ｚは−ＳＯ_２−又は−ＣＯ−、Ｒ^１〜Ｒ^１６は水素等を表す。］
第一工程：化合物（１）と（２）を反応させて、副生塩とジフェニルスルホンと芳香族ポリエーテルを含む反応混合物を得る。
第二工程：反応混合物から副生塩を除去後、ジフェニルスルホンを分離して、芳香族ポリエーテルを得る。
第三工程：ジフェニルスルホンを水洗し、残存する水を除去する。
第四工程：水を除去したジフェニルスルホンを用いて化合物（１）と（２）を反応させ、上記反応混合物を得る。
第五工程：第二〜第四工程を繰り返す。
【選択図】 なしAn object of the present invention is to provide a method for producing an aromatic polyether having a low degree of coloring.
A method for producing an aromatic polyether by subjecting a dihydric phenol compound (1) and a dihalogenated biphenyl compound (2) to a condensation reaction in the presence of a base and diphenyl sulfone as a reaction solvent, A method for producing an aromatic polyether, comprising the following first to fifth steps.

[Wherein, Y and Z represent —SO ₂ — or —CO—, and R ^{1 to} R ¹⁶ represent hydrogen and the like. ]
First step: Compounds (1) and (2) are reacted to obtain a reaction mixture containing a by-product salt, diphenyl sulfone, and an aromatic polyether.
Second step: After removing by-product salts from the reaction mixture, diphenyl sulfone is separated to obtain an aromatic polyether.
Third step: diphenyl sulfone is washed with water to remove remaining water.
Fourth step: Compounds (1) and (2) are reacted with diphenylsulfone from which water has been removed to obtain the above reaction mixture.
Fifth step: The second to fourth steps are repeated.
[Selection diagram] None

Description

［式中、Ｙは単結合、炭素数１〜５のアルキレン基、式−ＣＨ（Ｔ_１）−｛式中、Ｔ_１はフェニル基を表す。｝で示される２価基、式−Ｃ（Ｔ_２）（Ｔ_３）−｛式中、Ｔ_２は炭素数１〜５のアルキル基を表し、Ｔ_３は水素原子、炭素数１〜５のアルキル基又は炭素数４〜７のシクロアルキル基を表す。｝で示される２価基、−Ｏ−、−ＣＯ−、−ＳＯ_２−、−Ｓ−又は下式（４）
【００１１】
【化５】

（４）
｛式中、ａは２〜５の整数を表す。｝
で示される２価基を表す。Ｒ^１〜Ｒ^８は、それぞれ独立に、水素原子、炭素数１〜４のアルキル基又は炭素数１〜４のアルコキシ基を表す。］
【００１２】
【化６】

（式中、Ｚは−ＳＯ_２−又は−ＣＯ−を表し、Ｒ^９〜Ｒ^１６は、それぞれ独立に、水素原子、炭素数１〜４のアルキル基又は炭素数１〜４のアルコキシ基を表す。ＸおよびＸ’は、それぞれ独立にハロゲン原子を表す。）
以下、本発明を詳細に説明する。
【００１３】
【発明の実施の形態】
式（１）におけるＹで表されるアルキレン基としては、例えば、メチレン基、エチレン基、プロピレン基、ブチレン基などが挙げられる。
また、式−Ｃ（Ｔ_２）（Ｔ_３）−で示される２価基におけるＴ_２及びＴ_３で表される炭素数１〜５のアルキル基としては、例えば、メチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、ｉ−ブチル基、ｎ−アミル基等が挙げられる。
上記のＴ_３で表される炭素数４〜７のシクロアルキル基としては、例えば、シクロペンチル基やシクロへキシル基等が挙げられる。
Ｒ^１〜Ｒ^８で表されるアルキル基としては、例えば、メチル基、エチル基、ｎ−プロピル基、ｔ−ブチル基等の炭素数１〜４のアルキル基が挙げられる。また、Ｒ^１〜Ｒ^８で表されるアルコキシ基としては、例えば、メトキシ基、エトキシ基、ｎ−ブトキシ基、ｔ−ブトキシ基等の炭素数１〜４のアルコキシ基が挙げられる。
【００１４】
式（１）で示されるビフェノール化合物の中でも、４，４’−ジヒドロキシジフェニルスルホン、４，４’−ジヒドロキシジフェニル、４，４’−ジヒドロキシジフェニルスルフィド、４，４’−ジヒドロキシベンゾフェノン、２，２−ビス−（４−ヒドロキシフェニル）プロパン又はビス−（４−ヒドロキシフェニル）メタン；該例示化合物の３位、５位、３’位及び５’位から選ばれる少なくとも１つの炭素原子にメチル基が結合したビスフェノールが好ましく、とりわけ４，４’−ジヒドロキシジフェニルスルホンが好適である。
【００１５】
式（２）におけるＺは、−ＳＯ_２−又は−ＣＯ−を表す。
式（２）におけるＲ^９〜Ｒ^１６で表される炭素数１〜４のアルキル基としては、例えば、式（１）におけるＲ^１〜Ｒ^８において説明した基と同様のアルキル基が挙げられる。また、式（２）におけるＲ^９〜Ｒ^１６で表される炭素数１〜４のアルコキシ基としては、例えば、式（１）におけるＲ^１〜Ｒ^８において説明した基と同様のアルコキシ基が挙げられる。
Ｘ及びＸ’で表されるハロゲン原子としては、例えば、フッ素、塩素、臭素等が挙げられる。好適なハロゲン原子は、フッ素又は塩素である。
式（２）で示されるジハロゲン化ビフェニル化合物の中でも、４，４’−ジクロロジフェニルスルホン、４，４’−ジフロロジフェニルスルホン、４，４’−ジクロロベンゾフェノン、４，４’−ジフロロベンゾフェノン；これらの例示化合物の３位、５位、３’位及び５’位から選ばれる少なくとも１つの炭素原子にメチル基が結合した化合物が好ましい。とりわけ、４，４’−ジクロロジフェニルスルホンが好ましい。
【００１６】
本発明においては、ビフェノール化合物（１）とジハロゲン化ビフェニル化合物（２）を反応させる際に、下式（３）
【００１７】
【化７】

（式中、Ａは−ＳＯ_２−又は−ＣＯ−を表し、Ｒ^１７〜Ｒ^２４は、それぞれ独立に、水素原子、炭素数１〜４のアルキル基又は炭素数１〜４のアルコキシ基を表す。Ｘ”はハロゲン原子を表す。）
で示されるモノハロゲン化ビフェニル化合物を共存させてもよい。
【００１８】
モノハロゲン化ビフェニル化合物（３）におけるＲ^１７〜Ｒ^２４で表されるアルキル基としては、例えば、式（１）におけるＲ^１〜Ｒ^８において説明した基と同様の炭素数１〜４のアルキル基が挙げられる。
モノハロゲン化ビフェニル化合物（３）におけるＲ^１７〜Ｒ^２４で表されるアルコキシ基としては、例えば、式（１）におけるＲ^１〜Ｒ^８において説明した基と同様の炭素数１〜４のアルコキシ基が挙げられる。
モノハロゲン化ビフェニル化合物（３）におけるＸ”はハロゲン原子を表し、該ハロゲン原子としては前記式（２）におけるＸ及びＸ’と同様の原子が挙げられる。
モノハロゲン化ビフェニル化合物（３）の中でも、４−（４−クロロフェニルスルホニル）フェノール、４−（４−フロロフェニルスルホニル）フェノール、４−（４−クロロベンゾイル）フェノール、４−ヒドロキシ−４’−（４−クロロフェニルスルホニル）ビフェニル、４−（４−ヒドロキシフェニルスルホニル）−４’−（４−クロロフェニルスルホニル）ビフェニル等が好ましい。
【００１９】
本発明の第一工程においては、塩基と、反応溶媒としてのジフェニルスルホンの共存下に、ビフェノール化合物（１）及びジハロゲン化ビフェニル化合物（２）、更に必要に応じて、モノハロゲン化ビフェニル化合物（３）を縮合反応させて、該縮合反応により脱離したハロゲン化水素と塩基の反応生成物である副生塩と、ジフェニルスルホンと、芳香族ポリエーテルとを含む反応混合物を得る。
【００２０】
上記化合物（１）、（２）及び（３）の使用割合は、化合物（１）及び化合物（３）に含まれるフェノール性水酸基の合計１当量に対して、通常は化合物（２）及び化合物（３）に含まれるハロゲン原子の総使用量が０．９〜１．１当量の範囲であり、好ましくは０．９８〜１．０５当量の範囲である。
具体的に説明すると、例えば、化合物（１）と化合物（２）を縮合反応させて芳香族ポリエーテルを製造する場合、化合物（１）の１当量に対して、通常は化合物（２）を０．９〜１．１当量の範囲であり、好ましくは０．９８〜１．０５当量の範囲で使用する。
【００２１】
本発明において使用する塩基としては、好ましくは、アルカリ金属の炭酸塩及び／又はアルカリ金属の重炭酸塩である。中でも炭酸ナトリウム、炭酸カリウム；又は重炭酸ナトリウム、重炭酸カリウムが好適である。
塩基の使用量は、上記化合物（１）、（２）及び（３）における総フェノール性水酸基の１当量に対して、通常は１当量以上であり、好ましくは１．００５〜１．２５当量程度である。
塩基の使用量がフェノール性水酸基の１当量に対して１．２５当量以下であると、副反応が低減する傾向にあることから好ましい。また、塩基の使用量がフェノール性水酸基の１当量に対して１当量以上であると得られる芳香族ポリエーテルの分子量が増大する傾向にあることから好ましい。
本発明の製造法において、縮合反応温度は、通常は２１０〜３２０℃の範囲であり、好ましくは２４０〜２９０℃の範囲である。縮合反応温度が２１０℃を超えると、得られる芳香族ポリエーテルの分子量が増大する傾向にあることから好ましく、３２０℃未満であると着色が低減される傾向にあることから好ましい。
縮合反応に要する時間は、上記化合物（１）、（２）及び（３）の種類、反応形式や反応温度等により異なるが、通常は１〜２４時間程度であり、好ましくは２〜１２時間程度である。
【００２２】
本発明は、上記化合物（１）、（２）及び（３）の混合時や反応時等に、不活性ガス気流下で実施することが望ましい。これにより、上記の化合物（１）、（２）及び（３）や、縮合反応の生成物である芳香族ポリエーテルの酸化による着色を軽減することができる。
本発明における縮合反応は、通常は、芳香族ポリエーテルを含む反応混合物を冷却することにより停止することができる。また、芳香族ポリエーテルの末端フェノキサイドを不活性化させる目的で、ハロゲン化物等を添加して重合反応を停止させてもよい。
上記のハロゲン化物としては、メチルクロライド、エチルクロライド、メチルブロマイド等の脂肪族ハロゲン化物；４−クロロジフェニルスルホン、４−フロロジフェニルスルホン、４−クロロベンゾフェノン、４−フロロベンゾフェノン、４，４’−ジフロロジフェニルスルホン、４，４’−ジクロロジフェニルスルホン、４，４’−ジフロロベンゾフェノン、ｐ−クロロニトロベンゼン等の芳香族ハロゲン化物等が挙げられる。
【００２３】
本発明の第二工程は、第一工程で得た反応混合物から上記の塩基とハロゲン化水素の中和反応により生成した副生塩を除去し、その後、芳香族ポリエーテルとジフェニルスルホンを分離して、芳香族ポリエーテルを得る工程である。
縮合反応の終了後、得られた反応混合物から芳香族ポリエーテルを単離する方法としては、例えば、次の方法等が挙げられる。
先ず、芳香族ポリエーテルと、塩基（アルカリ金属炭酸塩及び／又はアルカリ金属重炭酸塩等）及びハロゲン化水素の中和反応により生成した副生塩と、ジフェニルスルホン溶媒との混合物を冷却して固化させた後、粉砕する。次いで、該粉砕物を水洗して、上記の副生塩を除去する。
その後、副生塩を除去した反応混合物から、固体のジフェニルスルホンを溶解するが、芳香族ポリエーテルを溶解しない溶媒を用いて洗浄することにより、ジフェニルスルホンを抽出することができる。
ジフェニルスルホンを溶解するが、芳香族ポリエーテルを溶解しない溶媒としては、例えば、メタノール、アセトン、イソプロパノール、メチルエチルケトン又はエタノール等の低沸点溶媒、及びこれらの混合物等が挙げられる。
【００２４】
本発明の第三工程では、第二工程で芳香族ポリエーテルと分離したジフェニルスルホンを水洗することにより精製し、その後、ジフェニルスルホン中に残存する水を除去する。
具体的には、例えば、下記の方法が挙げられる。
先ず、第二工程の抽出により得たジフェニルスルホン溶液から、上記例示の低沸点溶媒や低沸点溶媒混合物を蒸留により除去する。次いで、該溶媒を除去した後の回収ジフェニルスルホンを水洗する。その後、ジフェニルスルホン中に残存する水を除去することにより、反応溶媒としてのジフェニルスルホンを回収、再使用することができる。
上記の低沸点溶媒や低沸点溶媒混合物を蒸留する際の液の温度は、通常は１２５〜２００℃の範囲である。１２５℃未満ではジフェニルスルホンが固化して流動性がなくなり、２００℃を超えると回収したジフェニルスルホンの着色が著しくなる。ここで、上記の低沸点溶媒や低沸点溶媒混合物は凝縮させて回収し、再使用することもできる。
【００２５】
上記の蒸留後、蒸留釜内に残存するジフェニルスルホンを水で洗浄する際の温度は、通常０〜１８０℃の範囲である。
洗浄温度がジフェニルスルホンの融点（１２３〜１２５℃）未満である場合は、粉末状にしたジフェニルスルホンを水と混合して洗浄後、濾過すればよい＜水洗法（１）＞。
【００２６】
一方、洗浄温度がジフェニルスルホンの融点よりも高い場合は、０．１ＭＰａ以上の高圧下で洗浄を行い、洗浄後の混合物を静置して分液させた後、ジフェニルスルホン層を回収すればよい＜水洗法（２）＞。
洗浄温度が０℃よりも低いと水が固化し、一方、１８０℃よりも高いと洗浄時の圧力が１ＭＰａを超えて洗浄設備の耐圧化が要求される。
水洗法（１）及び（２）において、洗浄に使用する水の量は、ジフェニルスルホンに対して、通常は０．００１〜１０重量倍の範囲、好ましくは０．０１〜２重量倍の範囲である。
洗浄時間は、通常は５分〜５時間の範囲、好ましくは１０分〜２時間の範囲である。
【００２７】
水で洗浄後の精製ジフェニルスルホンを芳香族ポリエーテルの製造に再使用する際には、ジフェニルスルホン中の水分を除去する必要がある。
水の除去方法としては、水洗法（１）の場合は、粉末状のジフェニルスルホンを水と混合して洗浄、濾過後に乾燥すればよい。
また、水洗法（２）の場合は、上述した水で洗浄後のジフェニルスルホン層を、攪拌を停止して静置することによって水を分離させた後、ジフェニルスルホンを冷却、固化し、更に粉砕後、乾燥させる方法や、水で洗浄し、分液した後のジフェニルスルホン層を再度蒸留することによって水を除去する方法等が挙げられる。
【００２８】
本発明の製造法で得られた芳香族ポリエーテルは、必要に応じて乾燥することにより、透明性の優れた樹脂とすることができる。
また、射出成形機や押出成形機等により、所望の成形品を得ることもできる。成形機で成形する際には、ミルドガラスファイバー、チョップドガラスファイバー等のガラス繊維、無機充填剤、シラン系カップリング剤、チタネート系カップリング剤、ボラン系カップリング剤等の反応性カップリング剤、高級脂肪酸、高級脂肪酸エステル、高級脂肪酸金属塩、フルオロカーボン系界面活性剤等の潤滑剤、フッ素樹脂、金属石鹸類などの離型改良剤、核剤、酸化防止剤、安定剤、可塑剤、滑剤、着色防止剤、着色剤、紫外線吸収剤、帯電防止剤、潤滑剤および難燃剤などを添加してもよい。
但し、ガラス代替材料等の透明性を求められる用途には、ガラス繊維、無機充填剤、着色剤等の透明性を低下せしめる添加剤を使用しないことが好ましい。
【００２９】
【実施例】
以下、実施例等によって本発明をより詳細に説明するが、本発明はこれらの例によって限定されるものではない。
【００３０】
（１）分子量
芳香族ポリエーテルの分子量は、還元粘度を測定することによって求めた。還元粘度の値が大きいほど、高分子量であることを示す。
実施例及び比較例中の還元粘度（ＲＶ）は、次式により定義される。
ＲＶ＝［１／Ｃ］×［（ｔ−ｔ_０）／ｔ_０］
ｔ：重合体溶液の流出時間（秒）
ｔ_０：純溶媒の流出時間（秒）
Ｃ：重合体の溶液の濃度（ｇ／１００ｍｌ溶媒で表示）
粘度の測定は、オストワルド型粘度管を使用して、２５℃で行った。粘度測定のための重合体溶液の濃度は、Ｎ，Ｎ−ジメチルホルムアミド（試薬特級）溶液中１．０ｇ／１００ｍｌとした。
（２）透過率（着色度）の測定
芳香族ポリエーテル６．０ｇを、Ｎ，Ｎ−ジメチルホルムアミド（試薬特級）１００ｍｌに溶解し、日本ウオーターズ社製のＷＴＰＳ Ｖｅｒｉｆｉｅｄ Ｆｉｌｔｅｒ（０．４５μｍ）で濾過した。続いて、得られた濾液を光路長１０ｃｍのガラスセルに入れ、島津製作所製の分光光度計ＵＶ−２４００ＰＣにより、４００ｎｍにおける光線透過率（％）を求めた。
透過率が大きいほど、その波長における着色度が小さく、透明性に優れることを表す。
【００３１】
実施例１−（１）
［試薬級のジフェニルスルホンを使用した芳香族ポリエーテルの製造例］
攪拌機、窒素導入管、温度計、及び先端に受器を付したコンデンサーを備えた反応容器中に、モノマーとしての４，４’−ジヒドロキシジフェニルスルホン１００．１１重量部、モノマーとしての４，４’−ジクロロジフェニルスルホン１１９．９２重量部、及びジフェニルスルホン１９６重量部（４００ｎｍの光線透過率９６．５％、ＵＣＢ社製）を仕込み、容器内を窒素雰囲気に置換した後、さらに窒素を容器内に流通させながら、１８０℃まで昇温して上記のモノマーを溶解させた。次いで、無水炭酸カリウムを５７．５重量部添加した。その後、２８０℃まで徐々に昇温して、同温度で４．５時間反応させた（本発明の第一工程に相当する）。
反応終了後、反応液を室温まで冷却して固化させ、細かく粉砕した。得られた芳香族ポリエーテル、塩基とハロゲン化水素の中和反応により生成した副生塩、及びジフェニルスルホンの粉末状混合物を温水で洗浄して、上記の副生塩を除去した。次に、副生塩を除去した後の混合物をアセトン／メタノール混合液で抽出後、アセトンとメタノール及び水分を留去して回収ジフェニルスルホンを得た。
アセトン／メタノール混合液で抽出した後の残分を１５０℃に加熱し、還元粘度が０．３５１ｄｌ／ｇである芳香族ポリエーテルを得た（本発明の第二工程に相当する）。
この芳香族ポリエーテルの４００ｎｍにおける光線透過率は、３８．４％であった。
【００３２】
比較例１
［実施例１−（１）で得た回収ジフェニルスルホンを用いた芳香族ポリエーテルの製造例］
ＵＣＢ社製のジフェニルスルホンに代えて、実施例１−（１）で得た回収ジフェニルスルホン（４００ｎｍにおける光線透過率は９２．０％）をそのまま使用した以外は実施例１−（１）と同様にして、還元粘度が０．３４３ｄｌ／ｇである芳香族ポリエーテルを得た。
この芳香族ポリエーテルの４００ｎｍにおける光線透過率は２６．７％であった。
【００３３】
実施例１−（１）で得た回収ジフェニルスルホンをそのまま用いて反応させたところ、得られた芳香族ポリエーテルの着色度は試薬級のジフェニルスルホンを用いた場合よりも大きく、透明性が劣っていた。
【００３４】
実施例１−（２）
［回収ジフェニルスルホンの精製｛水洗法（２）｝］
攪拌機、窒素導入管、温度計及びコンデンサーを備えた耐圧容器中に、実施例１−（１）で得た回収ジフェニルスルホンと同じジフェニルスルホンの５００重量部と純水２５０重量部とを仕込み、容器内を０．５ＭＰａの窒素ガスで加圧後、パージして常圧に戻す操作を３回繰り返すことにより、窒素で置換した。その後、容器を密閉し、１３０℃まで昇温した。容器内の温度が１３０℃に到達し、ジフェニルスルホンが融解したのを確認後、３０分攪拌した。次いで、攪拌を停止すると、５分以内に水層とジフェニルスルホン層の明瞭な界面が観測された。水層を分離後、１００℃以下に冷却し、耐圧容器から精製ジフェニルスルホンを取り出し、粉砕後、８０℃の減圧乾燥機で残存する水分を除去した（本発明の第三工程）。
水分除去後の精製ジフェニルスルホンの４００ｎｍにおける光線透過率は、９４．４％であった。
【００３５】
実施例１−（３）
［水分除去後の精製ジフェニルスルホンを用いた芳香族ポリエーテルの製造例］
実施例１−（２）で得た水分除去後の精製ジフェニルスルホン（４００ｎｍにおける光線透過率は９４．４％）を用いた以外は、比較例１と同様に反応して、反応混合物を得た（本発明の第四工程）。
実施例１−（１）と同様にして、反応混合物から副生塩を除去し、その後、芳香族ポリエーテルとジフェニルスルホンを分離した。
次に、実施例１−（２）と同様にして回収ジフェニルスルホンを水洗し、水層を分離した。水層を分離した後の精製ジフェニルスルホン層を１００℃以下に冷却し、耐圧容器からジフェニルスルホンを取り出して、粉砕した。粉砕後のジフェニルスルホンを８０℃の減圧乾燥機に入れて、ジフェニルスルホン中に残存する水分を除去した後、縮合反応を行って、還元粘度が０．３７３ｄｌ／ｇである芳香族ポリエーテルを得た（本発明の第五工程）。
この芳香族ポリエーテルの４００ｎｍにおける光線透過率は、３７．７％であり、ＵＣＢ社製のジフェニルスルホンを用いて製造した芳香族ポリエーテルの光線透過率（３８．４％）とほぼ同等であった［実施例１−（１）を参照］。
【００３６】
【発明の効果】
本発明によれば、縮合反応により得た反応混合物から回収したジフェニルスルホンを水洗して精製し、該精製ジフェニルスルホンを脱水後に再使用することにより、着色の度合いが僅かな芳香族ポリエーテルを工業的有利に製造することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing an aromatic polyether by subjecting a biphenol compound (1) and a dihalogenated biphenyl compound (2) to a condensation reaction in the presence of a base and diphenyl sulfone as a reaction solvent.
[0002]
[Prior art]
Aromatic polyether is useful as a polymer compound having excellent heat resistance, impact resistance, transparency, and the like. A method for producing an aromatic polyether by subjecting such an aromatic polyether to a condensation reaction between a biphenol compound (1) and a dihalogenated biphenyl compound (2) in the presence of a base and diphenyl sulfone as a reaction solvent is patented. It is disclosed in Reference 1.
[0003]
[Patent Document 1]
JP-A-53-97094 (see Examples)
[0004]
[Problems to be solved by the invention]
Since diphenyl sulfone has a high boiling point and excellent stability at high temperatures, it is useful as a reaction solvent when producing an aromatic polyether by the above condensation reaction. There is no mention of reuse.
[0005]
Therefore, the present inventors have found that when diphenyl sulfone which is solid at room temperature is recovered from the reaction mixture obtained after the above condensation reaction, the reaction mixture is cooled to a powder, and then the reaction between the hydrogen halide and the base is performed. The by-product salt, which is a product, is removed by washing with water, and then the powder after removing the by-product salt is washed with a low boiling point solvent that dissolves diphenylsulfone but does not dissolve aromatic polyether. Can be recovered as a solution with a low boiling point solvent.
However, the present inventors have found that the recovered diphenylsulfone obtained by distilling the low-boiling solvent from the solution of diphenylsulfone and the low-boiling solvent is used as it is as a reaction solvent when producing an aromatic polyether. It has been found that the obtained aromatic polyether has a more remarkable degree of coloring than the aromatic polyether produced using diphenyl sulfone which is not a recovered product as described in Patent Document 1.
[0006]
An object of the present invention is to recover and reuse diphenyl sulfone as a reaction solvent from a reaction mixture containing an aromatic polyether, and to produce an aromatic polyether having a small degree of coloration in an industrially advantageous manner. It is to provide.
[0007]
[Means for Solving the Problems]
The present inventors have conducted intensive studies and, as a result, in the presence of a base and diphenyl sulfone as a reaction solvent, a reaction obtained when an aromatic polyether is produced by subjecting a plurality of specific starting compounds to a condensation reaction. The by-product salt, which is a reaction product of hydrogen halide and base, is removed from the mixture, and then the aromatic polyether and diphenyl sulfone are separated, and the separated diphenyl sulfone is purified by washing with water. It has been found that the above object can be achieved by reusing as a reaction solvent after removing, and the present invention has been completed.
[0008]
That is, the present invention provides an aromatic compound by a condensation reaction between a biphenol compound represented by the following formula (1) and a dihalogenated biphenyl compound represented by the following formula (2) in the presence of a base and diphenyl sulfone as a reaction solvent. The present invention provides a method for producing an aromatic polyether, which comprises the following first to fifth steps.
[0009]
First step)
The above-mentioned biphenol compound (1) and the dihalogenated biphenyl compound (2) are subjected to a condensation reaction in the coexistence of a base and diphenyl sulfone, and a by-product which is a reaction product of the hydrogen halide released by the condensation reaction and the base. Obtaining a reaction mixture containing a salt, diphenylsulfone, and an aromatic polyether,
Second step)
Removing the by-product salt from the obtained reaction mixture, and then separating the aromatic polyether and diphenyl sulfone to obtain an aromatic polyether,
Third step)
After washing the diphenyl sulfone separated in the second step with water, removing water remaining in the diphenyl sulfone,
4th process)
The above-mentioned biphenol compound (1) and the dihalogenated biphenyl compound (2) are reacted in the presence of a base and diphenyl sulfone after removing the remaining water obtained in the third step, and A step of obtaining a reaction mixture containing a by-product salt that is a reaction product of a base, diphenyl sulfone, and an aromatic polyether;
Fifth process)
A step of repeating the above-mentioned second step to fourth step).
[0010]
Embedded image

[Wherein, Y represents a single bond, an alkylene group having 1 to 5 carbon atoms, and formula -CH (T ₁ )-}, wherein T ₁ represents a phenyl group. Divalent group represented by}, the formula _{-C (T 2) (T 3} ) - { wherein, _{T 2} represents an alkyl group having 1 to 5 carbon atoms, _{T 3} is hydrogen atom, a C1-5 Represents an alkyl group or a cycloalkyl group having 4 to 7 carbon atoms. Divalent group represented by}, -O -, - CO - , - SO 2 -, - S- or the formula (4)
[0011]
Embedded image

(4)
ＡIn the formula, a represents an integer of 2 to 5. ｝
Represents a divalent group represented by R ^{1 to} R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. ]
[0012]
Embedded image

(Wherein, Z represents —SO ₂ — or —CO—, and R ^{9 to} R ¹⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. X and X 'each independently represent a halogen atom.)
Hereinafter, the present invention will be described in detail.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Examples of the alkylene group represented by Y in the formula (1) include a methylene group, an ethylene group, a propylene group, and a butylene group.
Examples of the alkyl group having 1 to 5 carbon atoms represented by T ₂ and T ₃ in the divalent group represented by the formula —C (T ₂ ) (T ₃ ) — include, for example, a methyl group, an ethyl group, and n -Propyl group, i-propyl group, n-butyl group, i-butyl group, n-amyl group and the like.
Examples of the cycloalkyl group having a carbon number of 4-7 represented by the above T _3, e.g., cyclohexyl group and the like into a cyclopentyl group or a cycloalkyl.
Examples of the alkyl group represented by R ^{1 to} R ⁸ include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, and a t-butyl group. Examples of the alkoxy group represented by R ^{1 to} R ⁸ include a C ¹ to C 4 alkoxy group such as a methoxy group, an ethoxy group, an n-butoxy group, and a t-butoxy group.
[0014]
Among the biphenol compounds represented by the formula (1), 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxybenzophenone, 2,2- Bis- (4-hydroxyphenyl) propane or bis- (4-hydroxyphenyl) methane; a methyl group bonded to at least one carbon atom selected from the 3-, 5-, 3'- and 5'-positions of the exemplified compound Bisphenol is preferred, and 4,4'-dihydroxydiphenylsulfone is particularly preferred.
[0015]
Z in the formula (2) is, -SO ₂ - represents a or -CO-.
Examples of the alkyl group having 1 to 4 carbon atoms represented by R ^{9 to} R ¹⁶ in the formula (2) include the same alkyl groups as the groups described in R ^{1 to} R ⁸ in the formula (1). In addition, examples of the alkoxy group having 1 to 4 carbon atoms represented by R ^{9 to} R ¹⁶ in Formula (2) include the same alkoxy groups as the groups described in R ^{1 to} R ⁸ in Formula (1). Can be
Examples of the halogen atom represented by X and X ′ include fluorine, chlorine, bromine and the like. Preferred halogen atoms are fluorine or chlorine.
Among the dihalogenated biphenyl compounds represented by the formula (2), 4,4′-dichlorodiphenylsulfone, 4,4′-difluorodiphenylsulfone, 4,4′-dichlorobenzophenone, 4,4′-difluorobenzophenone; Compounds in which a methyl group is bonded to at least one carbon atom selected from the 3-, 5-, 3'- and 5'-positions of these exemplified compounds are preferred. Especially, 4,4'-dichlorodiphenyl sulfone is preferable.
[0016]
In the present invention, when reacting the biphenol compound (1) with the dihalogenated biphenyl compound (2), the following formula (3)
[0017]
Embedded image

(Wherein, A represents —SO ₂ — or —CO—, and R ^{17 to} R ²⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. X "represents a halogen atom.)
And a monohalogenated biphenyl compound represented by
[0018]
Examples of the alkyl group represented by R ^{17 to} R ²⁴ in the monohalogenated biphenyl compound (3) include, for example, an alkyl group having 1 to 4 carbon atoms similar to the groups described for R ^{1 to} R ⁸ in the formula (1). Is mentioned.
Examples of the alkoxy group represented by R ^{17 to} R ²⁴ in the monohalogenated biphenyl compound (3) include, for example, the same alkoxy group having 1 to 4 carbon atoms as described for R ^{1 to} R ⁸ in the formula (1). Is mentioned.
X ″ in the monohalogenated biphenyl compound (3) represents a halogen atom, and examples of the halogen atom include the same atoms as X and X ′ in the formula (2).
Among the monohalogenated biphenyl compounds (3), 4- (4-chlorophenylsulfonyl) phenol, 4- (4-fluorophenylsulfonyl) phenol, 4- (4-chlorobenzoyl) phenol, 4-hydroxy-4 ′-( 4-Chlorophenylsulfonyl) biphenyl, 4- (4-hydroxyphenylsulfonyl) -4 ′-(4-chlorophenylsulfonyl) biphenyl and the like are preferable.
[0019]
In the first step of the present invention, the biphenol compound (1) and the dihalogenated biphenyl compound (2) and, if necessary, the monohalogenated biphenyl compound (3) are used in the presence of a base and diphenyl sulfone as a reaction solvent. Is subjected to a condensation reaction to obtain a reaction mixture containing a by-product salt which is a reaction product of hydrogen halide eliminated by the condensation reaction and a base, diphenyl sulfone, and an aromatic polyether.
[0020]
The use ratio of the above compounds (1), (2) and (3) is usually the compound (2) and the compound (2) based on 1 equivalent of the total of phenolic hydroxyl groups contained in the compound (1) and the compound (3). The total amount of halogen atoms contained in 3) is in the range of 0.9 to 1.1 equivalents, and preferably in the range of 0.98 to 1.05 equivalents.
Specifically, for example, when a compound (1) and a compound (2) are subjected to a condensation reaction to produce an aromatic polyether, the compound (2) is usually added with 0 per equivalent of the compound (1). It is used in the range of 0.9 to 1.1 equivalents, preferably in the range of 0.98 to 1.05 equivalents.
[0021]
The base used in the present invention is preferably an alkali metal carbonate and / or an alkali metal bicarbonate. Among them, sodium carbonate and potassium carbonate; or sodium bicarbonate and potassium bicarbonate are preferable.
The amount of the base to be used is generally 1 equivalent or more, preferably about 1.005 to 1.25 equivalent, relative to 1 equivalent of the total phenolic hydroxyl group in the compounds (1), (2) and (3). It is.
It is preferable that the amount of the base used is 1.25 equivalent or less based on 1 equivalent of the phenolic hydroxyl group, since a side reaction tends to be reduced. Further, it is preferable that the amount of the base used is 1 equivalent or more with respect to 1 equivalent of the phenolic hydroxyl group, since the molecular weight of the obtained aromatic polyether tends to increase.
In the production method of the present invention, the condensation reaction temperature is usually in the range of 210 to 320 ° C, and preferably in the range of 240 to 290 ° C. When the condensation reaction temperature exceeds 210 ° C., the molecular weight of the obtained aromatic polyether tends to increase, and when it is less than 320 ° C., the coloring tends to decrease, so that it is preferable.
The time required for the condensation reaction varies depending on the types of the compounds (1), (2) and (3), the reaction mode and the reaction temperature, but is usually about 1 to 24 hours, preferably about 2 to 12 hours. It is.
[0022]
The present invention is desirably carried out in an inert gas stream when mixing or reacting the compounds (1), (2) and (3). Thereby, coloring of the compounds (1), (2) and (3) and the aromatic polyether, which is a product of the condensation reaction, due to oxidation can be reduced.
The condensation reaction in the present invention can be usually stopped by cooling the reaction mixture containing the aromatic polyether. For the purpose of inactivating the terminal phenoxide of the aromatic polyether, a polymerization reaction may be stopped by adding a halide or the like.
Examples of the halide include aliphatic halides such as methyl chloride, ethyl chloride, and methyl bromide; 4-chlorodiphenylsulfone, 4-fluorodiphenylsulfone, 4-chlorobenzophenone, 4-fluorobenzophenone, and 4,4′-diamine. Aromatic halides such as fluorodiphenylsulfone, 4,4'-dichlorodiphenylsulfone, 4,4'-difluorobenzophenone, p-chloronitrobenzene and the like can be mentioned.
[0023]
In the second step of the present invention, the base and the by-product salt generated by the neutralization reaction of hydrogen halide are removed from the reaction mixture obtained in the first step, and thereafter, the aromatic polyether and diphenyl sulfone are separated. To obtain an aromatic polyether.
As a method for isolating the aromatic polyether from the obtained reaction mixture after completion of the condensation reaction, for example, the following methods can be mentioned.
First, a mixture of an aromatic polyether, a base (such as an alkali metal carbonate and / or an alkali metal bicarbonate) and a by-product salt generated by a neutralization reaction of hydrogen halide, and a diphenyl sulfone solvent are cooled. After solidifying, pulverize. Next, the pulverized material is washed with water to remove the by-product salt.
Thereafter, diphenyl sulfone can be extracted from the reaction mixture from which by-product salts have been removed, by washing with a solvent in which solid diphenyl sulfone is dissolved but aromatic polyether is not dissolved.
Examples of the solvent that dissolves diphenyl sulfone but does not dissolve aromatic polyether include low-boiling solvents such as methanol, acetone, isopropanol, methyl ethyl ketone, and ethanol, and mixtures thereof.
[0024]
In the third step of the present invention, the diphenyl sulfone separated from the aromatic polyether in the second step is purified by washing with water, and thereafter water remaining in the diphenyl sulfone is removed.
Specifically, for example, the following method is mentioned.
First, the low-boiling solvent or low-boiling solvent mixture exemplified above is removed from the diphenylsulfone solution obtained by the extraction in the second step by distillation. Next, the recovered diphenyl sulfone after removing the solvent is washed with water. Thereafter, diphenyl sulfone as a reaction solvent can be recovered and reused by removing water remaining in the diphenyl sulfone.
The temperature of the liquid at the time of distilling the above-mentioned low-boiling solvent or low-boiling solvent mixture is usually in the range of 125 to 200 ° C. If the temperature is lower than 125 ° C., diphenyl sulfone solidifies and loses fluidity. If the temperature exceeds 200 ° C., the color of the recovered diphenyl sulfone becomes remarkable. Here, the above-mentioned low-boiling-point solvent or low-boiling-point solvent mixture can be condensed and recovered, and reused.
[0025]
After the above-mentioned distillation, the temperature at which diphenyl sulfone remaining in the still is washed with water is usually in the range of 0 to 180 ° C.
When the washing temperature is lower than the melting point of diphenylsulfone (123 to 125 ° C.), the powdered diphenylsulfone may be mixed with water, washed, and then filtered (water washing method (1)).
[0026]
On the other hand, when the washing temperature is higher than the melting point of diphenylsulfone, washing is performed under a high pressure of 0.1 MPa or more, the mixture after washing is allowed to stand, and liquid separation is performed, and then the diphenylsulfone layer may be collected. <Washing method (2)>.
If the washing temperature is lower than 0 ° C., the water solidifies, while if it is higher than 180 ° C., the pressure at the time of washing exceeds 1 MPa and the pressure of the washing equipment must be increased.
In the water washing methods (1) and (2), the amount of water used for washing is usually in the range of 0.001 to 10 times by weight, preferably in the range of 0.01 to 2 times by weight, based on diphenyl sulfone. is there.
The washing time is usually in the range from 5 minutes to 5 hours, preferably in the range from 10 minutes to 2 hours.
[0027]
When reusing purified diphenyl sulfone after washing with water for the production of aromatic polyethers, it is necessary to remove water in the diphenyl sulfone.
As a method for removing water, in the case of the water washing method (1), powdery diphenyl sulfone may be mixed with water, washed, filtered, and dried.
In the case of the water washing method (2), the diphenyl sulfone layer washed with water is separated from the water by stopping stirring and leaving it to stand, and then cooled, solidified, and further pulverized. Thereafter, a method of drying, a method of washing with water and separating the diphenylsulfone layer after liquid separation to remove water by distillation again, and the like can be given.
[0028]
The aromatic polyether obtained by the production method of the present invention can be made into a resin having excellent transparency by drying as necessary.
Also, a desired molded product can be obtained by an injection molding machine or an extrusion molding machine. When molding with a molding machine, glass fiber such as milled glass fiber, chopped glass fiber, inorganic filler, silane coupling agent, titanate coupling agent, reactive coupling agent such as borane coupling agent, Lubricants such as higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, fluorocarbon surfactants, release improvers such as fluororesins, metal soaps, nucleating agents, antioxidants, stabilizers, plasticizers, lubricants, You may add a coloring prevention agent, a coloring agent, an ultraviolet absorber, an antistatic agent, a lubricant, a flame retardant, and the like.
However, for applications requiring transparency, such as glass substitute materials, it is preferable not to use additives such as glass fibers, inorganic fillers, and coloring agents that reduce the transparency.
[0029]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples and the like, but the present invention is not limited to these examples.
[0030]
(1) Molecular Weight The molecular weight of the aromatic polyether was determined by measuring the reduced viscosity. The higher the value of the reduced viscosity, the higher the molecular weight.
The reduced viscosity (RV) in Examples and Comparative Examples is defined by the following equation.
RV = [1 / C] × [(t−t ₀ ) / t ₀ ]
t: Outflow time of polymer solution (second)
t ₀ : Outflow time of pure solvent (second)
C: Concentration of polymer solution (expressed in g / 100 ml solvent)
The viscosity was measured at 25 ° C. using an Ostwald type viscosity tube. The concentration of the polymer solution for viscosity measurement was 1.0 g / 100 ml in a N, N-dimethylformamide (special grade reagent) solution.
(2) Measurement of transmittance (degree of coloring) 6.0 g of aromatic polyether was dissolved in 100 ml of N, N-dimethylformamide (special grade of reagent), and filtered through a WTPS Verifyed Filter (0.45 μm) manufactured by Nippon Waters. did. Subsequently, the obtained filtrate was put into a glass cell having an optical path length of 10 cm, and the light transmittance (%) at 400 nm was obtained with a spectrophotometer UV-2400PC manufactured by Shimadzu Corporation.
The higher the transmittance, the lower the degree of coloration at that wavelength, and the better the transparency.
[0031]
Example 1- (1)
[Production Example of Aromatic Polyether Using Reagent Grade Diphenyl Sulfone]
100.11 parts by weight of 4,4′-dihydroxydiphenylsulfone as a monomer and 4,4 ′ as a monomer were placed in a reaction vessel equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a condenser equipped with a receiver at the tip. -119.92 parts by weight of dichlorodiphenylsulfone and 196 parts by weight of diphenylsulfone (light transmittance of 400 nm: 96.5%, manufactured by UCB) were charged, and the atmosphere in the vessel was replaced with a nitrogen atmosphere. While flowing, the temperature was raised to 180 ° C. to dissolve the above monomers. Next, 57.5 parts by weight of anhydrous potassium carbonate was added. Thereafter, the temperature was gradually raised to 280 ° C., and the mixture was reacted at the same temperature for 4.5 hours (corresponding to the first step of the present invention).
After the completion of the reaction, the reaction solution was cooled to room temperature, solidified, and pulverized. The powdery mixture of the obtained aromatic polyether, a by-product salt formed by a neutralization reaction of a base and hydrogen halide, and diphenyl sulfone was washed with warm water to remove the by-product salt. Next, the mixture after removing the by-product salt was extracted with an acetone / methanol mixture, and acetone, methanol and water were distilled off to obtain recovered diphenylsulfone.
The residue after extraction with an acetone / methanol mixture was heated to 150 ° C. to obtain an aromatic polyether having a reduced viscosity of 0.351 dl / g (corresponding to the second step of the present invention).
The light transmittance at 400 nm of this aromatic polyether was 38.4%.
[0032]
Comparative Example 1
[Example of production of aromatic polyether using recovered diphenyl sulfone obtained in Example 1- (1)]
Same as Example 1- (1) except that the recovered diphenylsulfone (light transmittance at 400 nm: 92.0% at 400 nm) obtained in Example 1- (1) was used in place of diphenyl sulfone manufactured by UCB. Thus, an aromatic polyether having a reduced viscosity of 0.343 dl / g was obtained.
The light transmittance at 400 nm of this aromatic polyether was 26.7%.
[0033]
When the reaction was carried out using the recovered diphenylsulfone obtained in Example 1- (1) as it was, the coloring degree of the obtained aromatic polyether was larger than that obtained when reagent-grade diphenylsulfone was used, and the transparency was poor. I was
[0034]
Example 1- (2)
[Purification of recovered diphenyl sulfone {water washing method (2)}]
500 parts by weight of the same diphenyl sulfone as the recovered diphenyl sulfone obtained in Example 1- (1) and 250 parts by weight of pure water were charged into a pressure-resistant vessel equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a condenser. After pressurizing the inside with a nitrogen gas of 0.5 MPa, the operation of purging and returning to normal pressure was repeated three times, thereby purging with nitrogen. Thereafter, the vessel was sealed and heated to 130 ° C. After confirming that the temperature in the container reached 130 ° C. and the diphenyl sulfone was melted, the mixture was stirred for 30 minutes. Then, when stirring was stopped, a clear interface between the aqueous layer and the diphenylsulfone layer was observed within 5 minutes. After separating the aqueous layer, the mixture was cooled to 100 ° C. or lower, purified diphenylsulfone was taken out from the pressure-resistant container, and after pulverization, remaining water was removed by a vacuum dryer at 80 ° C. (third step of the present invention).
The light transmittance at 400 nm of the purified diphenylsulfone after removing the water was 94.4%.
[0035]
Example 1- (3)
[Production example of aromatic polyether using purified diphenyl sulfone after removal of water]
A reaction mixture was obtained in the same manner as in Comparative Example 1, except that the purified diphenylsulfone obtained after the removal of water obtained in Example 1- (2) (light transmittance at 400 nm was 94.4%) was used. (Fourth step of the present invention).
By-product salts were removed from the reaction mixture in the same manner as in Example 1- (1), and thereafter, aromatic polyether and diphenyl sulfone were separated.
Next, the recovered diphenyl sulfone was washed with water in the same manner as in Example 1- (2), and the aqueous layer was separated. After the aqueous layer was separated, the purified diphenylsulfone layer was cooled to 100 ° C. or lower, and diphenylsulfone was taken out from the pressure-resistant container and pulverized. The pulverized diphenylsulfone is placed in a vacuum drier at 80 ° C. to remove water remaining in the diphenylsulfone, and then subjected to a condensation reaction to obtain an aromatic polyether having a reduced viscosity of 0.373 dl / g. (Fifth step of the present invention).
The light transmittance at 400 nm of this aromatic polyether was 37.7%, which was almost equal to the light transmittance (38.4%) of the aromatic polyether produced using diphenyl sulfone manufactured by UCB. [See Example 1- (1)].
[0036]
【The invention's effect】
According to the present invention, diphenyl sulfone recovered from a reaction mixture obtained by a condensation reaction is purified by washing with water, and the purified diphenyl sulfone is reused after dehydration, whereby aromatic polyether with a small degree of coloring can be industrially produced. It can be advantageously manufactured.

Claims (3)

An aromatic polyether is produced by subjecting a biphenol compound represented by the following formula (1) and a dihalogenated biphenyl compound represented by the following formula (2) to a condensation reaction in the presence of a base and diphenyl sulfone as a reaction solvent. A method for producing an aromatic polyether, comprising the following first to fifth steps:
First step)
The above-mentioned biphenol compound (1) and the dihalogenated biphenyl compound (2) are subjected to a condensation reaction in the coexistence of a base and diphenyl sulfone, and a by-product which is a reaction product of the hydrogen halide released by the condensation reaction and the base. Obtaining a reaction mixture containing a salt, diphenylsulfone, and an aromatic polyether,
Second step)
Removing the by-product salt from the obtained reaction mixture, and then separating the aromatic polyether and diphenyl sulfone to obtain an aromatic polyether,
Third step)
After washing the diphenyl sulfone separated in the second step with water, removing water remaining in the diphenyl sulfone,
4th process)
The above-mentioned biphenol compound (1) and the dihalogenated biphenyl compound (2) are reacted in the presence of a base and diphenyl sulfone after removing the remaining water obtained in the third step, and A step of obtaining a reaction mixture containing a by-product salt that is a reaction product of a base, diphenyl sulfone, and an aromatic polyether;
Fifth step)
A step of repeating the above-mentioned second step to fourth step).

[Wherein, Y represents a single bond, an alkylene group having 1 to 5 carbon atoms, and formula -CH (T ₁ )-}, wherein T ₁ represents a phenyl group. Divalent group represented by}, the formula _{-C (T 2) (T 3} ) - { wherein, _{T 2} represents an alkyl group having 1 to 5 carbon atoms, _{T 3} is hydrogen atom, a C1-5 Represents an alkyl group or a cycloalkyl group having 4 to 7 carbon atoms. Divalent group represented by}, -O -, - CO - , - SO 2 -, - S- or the formula (4)

(4)
ＡIn the formula, a represents an integer of 2 to 5. ｝
Represents a divalent group represented by R ^{1 to} R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. ]

(Wherein, Z represents —SO ₂ — or —CO—, and R ^{9 to} R ¹⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. X and X 'each independently represent a halogen atom.) The production according to claim 1, wherein the biphenol compound represented by the formula (1) is 4,4'-dihydroxydiphenylsulfone, and the dihalogenated biphenyl compound represented by the formula (2) is 4,4'-dichlorodiphenylsulfone. Law. 3. The method according to claim 1, wherein the base is an alkali metal carbonate and / or an alkali metal bicarbonate.