JP3786610B2 - Method for producing crystallized aromatic polycarbonate - Google Patents

Description

【０００９】
［上記式（１）中、Ｒ₁、Ｒ₂、Ｒ₃およびＲ₄は、それぞれ独立に、水素原子、ハロゲン原子、炭素数１〜１０のアルキル基、炭素数７〜２０のアラルキル基または炭素数６〜２０のアリール基であり、Ｗは炭素数２〜１５のアルキリデン基、炭素数１〜１５のアルキレン基、炭素数３〜１５のシクロアルキリデン基、炭素数３〜１５のシクロアルキレン基、炭素数８〜２０のアルキレン−アリーレン−アルキレン基、酸素原子、硫黄原子、スルホキシド基、またはスルホン基である。］で表わされる固有粘度［η］が０．３８超〜０．５の非晶性芳香族ポリカーボネートをフェノール類と水を含む混合液または混合蒸気に接触させ、固有粘度［η］が０．０５〜０．３８の結晶化芳香族ポリカーボネートを得る結晶化芳香族ポリカーボネートの製造方法であり、第２の発明は上記の製造方法で得られた結晶化芳香族ポリカーボネートをそのガラス転移温度（Ｔｇ）以上融点（Ｔｍ）未満の温度範囲で、常圧かつ不活性ガス気流下、または減圧下で加熱し高重合度化する芳香族ポリカーボネート樹脂の製造方法である。
【００１０】
【発明の実施の形態】
本発明の製造方法における非晶性芳香族ポリカーボネートは主たる繰り返し単位が下記式（１）
【００１１】
【化３】

【００１２】
［上記式（１）中、Ｒ₁、Ｒ₂、Ｒ₃およびＲ₄は、それぞれ独立に、水素原子、ハロゲン原子、炭素数１〜１０のアルキル基、炭素数７〜２０のアラルキル基または炭素数６〜２０のアリール基であり、Ｗは炭素数２〜１５のアルキリデン基、炭素数１〜１５のアルキレン基、炭素数３〜１５のシクロアルキリデン基、炭素数３〜１５のシクロアルキレン基、炭素数８〜２０のアルキレン−アリーレン−アルキレン基、酸素原子、硫黄原子、スルホキシド基、またはスルホン基である。］
で表わされる。上記式（１）中、Ｒ₁，Ｒ₂，Ｒ₃，およびＲ₄は具体的には水素原子；フッ素原子、塩素原子、臭素原子等のハロゲン原子；メチル基、エチル基、プロピル基、ブチル基、ヘキシル基等の炭素数１〜１０のアルキル基；ベンジル基、フェネチル基等の炭素数７〜２０のアラルキル基；フェニル基、ナフチル基等の炭素数６〜２０のアリール基が挙げられる。Ｗは具体的にはエチリデン基、プロピリデン基、ブチリデン基等の炭素数２〜１５のアルキリデン基；メチレン基、エチレン基、プロピレン基、ブチレン基等の炭素数１〜１５のアルキレン基；シクロペンチリデン基、シクロヘキシリデン基等の炭素数３〜１５のシクロアルキリデン基；１，３−シクロペンチレン基、１，４−シクロヘキシレン基等の炭素数３〜１５のシクロアルキレン基、ｍ−ジイソピロピレンフェニレン基、ｐ−ジイソピロピレンフェニレン基等の炭素数８〜２０のアルキレン−アリーレン−アルキレン基；エーテル基、スルホキシド基、スルフィド基、スルホン基などが挙げられる。
【００１３】
これらの非晶性芳香族ポリカーボネートは、好ましくは、芳香族ジヒドロキシ化合物と炭酸ジエステルを、より好ましくはさらにエステル交換触媒の存在下、加熱溶融反応させる公知の溶融重合法、または固相重合法により製造される。
【００１４】
本願発明で使用される該芳香族ジヒドロキシ化合物としては、例えば２，２−ビス（４−ヒドロキシフェニル）プロパン（以下ビスフェノールＡと略す。）、ビス（２−ヒドロキシフェニル）メタン、１，１−ビス（４−ヒドロキシフェニル）エタン、１，１−ビス（４−ヒドロキシフェニル）プロパン、２，２−ビス（２−ヒドロキシフェニル）プロパン、２，２−ビス（４−ヒドロキシ−３，５−ジメチルフェニル）プロパン、２，２−ビス（４−ヒドロキシ−３，５−ジブロモフェニル）プロパン、２，２−ビス（４−ヒドロキシ−３−メチルフェニル）プロパン、２，２−ビス（４−ヒドロキシフェニル）ペンタン、３，３−ビス（４−ヒドロキシフェニル）ペンタン、１，１−ビス（４−ヒドロキシフェニル）シクロヘキサン、ビス（４−ヒドロキシフェニル）サルファイド、ビス（４−ヒドロキシフェニル）スルホン等およびその芳香環に例えばアルキル基、アリール基等が置換されたものがあげられる。これらは単独で用いても２種以上併用しても良い。これらの化合物の中で少なくとも１種は２，２−ビス（４−ヒドロキシフェニル）プロパンを含む化合物を用いることが好ましく、２，２−ビス（４−ヒドロキシフェニル）プロパンのみを用いることが更に好ましい。
【００１５】
また、該炭酸ジエステルとしては例えばジフェニルカーボネート、ジナフチルカーボネート、ビス（ジフェニル）カーボネート、ジメチルカーボネート、ジブチルカーボネート等が挙げられる。これらは単独で用いても２種以上併用しても良い。さらにはジフェニルカーボネートを用いることが好ましい。
【００１６】
本発明においては固有粘度［η］が０．３８超〜０．５、好ましくは０．３８超〜０．４５のものが好ましく使用される。なお、本発明で言う固有粘度［η］は、ジクロロメタン溶液にて温度２０℃で測定した粘度から算出される値である。本発明で使用する非晶性芳香族ポリカーボネートの固有粘度［η］が０．５を越えると十分な結晶化度を有する芳香族ポリカーボネートを得ることが非常に困難であり好ましくない。０．３８以下であると本発明の固相重合が早くなる効果が表れない。
【００１７】
本発明で用いる非晶性芳香族ポリカーボネートは結晶化度が０％の完全非晶状態のもの、あるいはそれに近い非晶性に富むものである。なお必要に応じて該非晶性ポリカーボネートは粉砕、分級などの操作を行い粒径、形状を整えることも好ましく選ばれる。
【００１８】
本発明において使用されるフェノール類としては、フェノール、ｏ−クロロフェノール、ｍ−クロロフェノール、ｐ−クロロフェノール、ｏ−クレゾール、ｍ−クレゾール、ｐ−クレゾール、１−ナフトール、２−ナフトール等のフェノール類を用いることが出来る。
【００１９】
これらの中でも、メタノール、エタノール、１−プロパノール、２−プロパノール、フェノールが好ましく、とりわけ、フェノールが特に好ましい。モノヒドロキシ化合物以外の有機化合物の液体または気体を用いると、非晶性芳香族ポリカーボネートの表面のみ結晶化し、内部に非晶部分が多く残るため融着しやすい問題が起こる。また表面の結晶化した部分だけが剥がれ落ち、微粉末を発生しやすい問題が起こりやすい。
【００２０】
次に本発明においては、非晶性芳香族ポリカーボネートをフェノール類と水の混合液または混合蒸気に接触させることによって結晶化する。該混合蒸気とは、フェノール類および水の両方とも完全に気体である場合、少なくとも一方が比較的液化しやすい条件下で両方とも気体として存在する場合、または蒸気圧に相当する微量以外の大部分は液体のまま存在する場合も含むものとする。フェノール類と水の混合液または混合蒸気は液体であることが好ましい。該混合液または混合蒸気と非晶性芳香族ポリカーボネートを接触させる温度は、該混合液または混合蒸気が固化しない温度である４０℃以上、１５０℃以下を好ましく選ぶことができるが、より好ましくは８０℃〜１１０℃である。この温度範囲はフェノールを用いた場合に特に好ましいものである。上記温度範囲より低い温度では結晶化芳香族ポリカーボネートの結晶化が不十分である、または結晶化しやすい固有粘度範囲である０．０５〜０．３８以下にまで解重合が進行せず好ましくない。逆に上記温度範囲より高い温度では結晶化芳香族ポリカーボネートの混合液または混合蒸気への溶解等が顕著となり好ましくない。該混合液または混合蒸気におけるフェノール類の含有量は１０重量％〜９０重量％であり、５０重量％〜８０重量％が好適に使用される。フェノール類含有量がこの範囲外の場合、芳香族ポリカーボネートの解重合が不十分である、結晶化が不十分である、または該混合液または混合蒸気が混合液の場合は該混合液への溶解が顕著となり目的達成が困難となる。非晶性芳香族ポリカーボネートの該混合液または混合蒸気への接触時間は１分〜１２０分の範囲が好ましく、これより短時間では結晶化が十分進行しない、また長時間では混合液または混合蒸気への溶解等の量が著しく多くなり好ましくない。このように決められた結晶化処理時間は、例えば加熱結晶化法で必要な時間に対して１/１０〜１/１００程度であり非常に短時間である。また、このようにして得られた結晶化芳香族ポリカーボネートは内部まで均一に結晶化され分子量が当初より低下するものの固有粘度が０．０５〜０．３８の範囲に自発的に制御され、また例えば加熱結晶化法で得られた同等の固有粘度をもつ結晶化芳香族ポリカーボネートと比較して固相重合速度が異常に速くなる。
【００２１】
本発明方法において非晶性芳香族ポリカーボネートにフェノール類と水の混合液または混合蒸気を接触する方法として以下の方法を例示できる。
（Ｉ）非晶性芳香族ポリカーボネートを粉砕・分級後、加熱したフェノール類と水の混合液または混合蒸気に浸漬させる方法。
（II）非晶性芳香族ポリカーボネートを、加熱したフェノール類水の混合液または混合蒸気に浸漬後、若しくは浸漬しながら造粒する方法。
（III）非晶性芳香族ポリカーボネートを造粒しながら固化させ、その後加熱したフェノール類と水の混合液または混合蒸気に浸漬させる方法。
（IV）上記（Ｉ）について混合液または混合蒸気の代わりにフェノール類と水の混合蒸気に暴露させる方法。
（Ｖ）上記（I）〜（IV）について、オートクレーブ等を使用し加圧下で実施する方法。
【００２２】
非晶性芳香族ポリカーボネートを該混合液または混合蒸気に接触させる場合、該混合液または混合蒸気と非晶性芳香族ポリカーボネートの量に制限はないが重量比で非晶性芳香族ポリカーボネート：混合液または混合蒸気＝１：０．５〜１：５００が好ましい。上記範囲外では非晶性芳香族ポリカーボネートが二次凝集してしまい内部の結晶化が困難になったり、溶解等してしまい結晶化芳香族ポリカーボネートの収率が低下するため好ましくない。
【００２３】
次にこのようにして製造した結晶化芳香族ポリカーボネートを使用して固相重合反応を進めることができる。また該結晶化芳香族ポリカーボネートを圧縮成形した圧縮粒状成形体を用いることも好ましい態様である。固相重合反応は固体状態を維持できるように、結晶化芳香族ポリカーボネートをそのガラス転移温度（Ｔｇ）以上融点（Ｔｍ）未満の温度で、常圧かつ不活性ガス気流下、または減圧下で加熱し高重合度化することが好ましい。そうして所望の分子量を有する高分子量の芳香族ポリカーボネート樹脂となる。
【００２４】
常圧下での重合は前述のとおり不活性ガス気流下で行われることが好ましい。固相重合槽に流通させる不活性ガスの種類としては、結晶化芳香族ポリカーボネート、その原料、および反応中で留出する化合物に対して不活性なヘリウム、アルゴン、窒素、二酸化炭素ガス等を例示できる。また固相重合温度は結晶化芳香族ポリカーボネートのガラス転移温度（Ｔｇ）以上融点（Ｔｍ）未満で行われることが好ましい。固相重合温度がＴｇ未満の場合は固相重合反応がほとんど起こらない。固相重合温度がＴｍ以上では結晶化芳香族ポリカーボネートが融着し、反応槽や配管を詰まらせる原因となる等の問題があり好ましくない。さらに具体的な好ましい態様として温度が上記の範囲内にある前提で、温度１４０〜３５０℃の不活性ガスを該結晶化芳香族ポリカーボネート１ｋｇあたり０．１ＮＬ／分以上の流量で、流通させることによって実施される。上記の不活性ガスの温度範囲内でも１４５〜３３０℃が更に好ましく、１５０〜３００℃が特に好ましい。例えば２，２−ビス（４−ヒドロキシフェニル）プロパンとジフェニルカーボネートとを溶融重縮合して芳香族ポリカーボネートを製造する場合、１５０〜３００℃の不活性ガスを流通させることが好ましく、１６０〜２８０℃が特に好ましい。また、重合度の上昇と共に、結晶化芳香族ポリカーボネートの融点も上昇するため、融点の上昇に伴い順次固相重合温度を上昇する方法も好ましく用いられる。
【００２５】
また不活性ガスの流量は、芳香族ポリカーボネートプレポリマーまたは圧縮粒状成形体１ｋｇあたり０．１ＮＬ／分以上１００ＮＬ／分以下が好ましく、特に１〜５０ＮＬ／分が特に好ましい。流通量が上記範囲より小さい場合、固相重合反応の進行が遅くなり、重合時間が長くなり好ましくない。流通量が上記範囲より大きい場合、熱エネルギーコストが高くなり好ましくない。
【００２６】
固相重合に要する時間は、通常、数時間〜数十時間が採用される。重合時間が長すぎると固相重合に使用する装置が大掛かりになり、設備製造コストの点で好ましくない。また芳香族ポリカーボネート樹脂の色相が悪化する問題もある。一方重合時間が短いと所望の重合度の芳香族ポリカーボネート樹脂が得られず、力学強度などが不十分な樹脂となる。また必要に応じて固相重合中に、結晶化芳香族ポリカーボネートを機械的に攪拌するか、あるいは気体流により攪拌してもよい。
【００２７】
本発明において使用される固相重合槽の形式について特に制限はないが、下部に不活性ガス導入部を有し上部に不活性ガス排出部を有する円筒型縦型反応装置、回転式の反応装置等を好ましい形態として例示できる。
【００２８】
また減圧下で固相重合を行う場合は非晶性芳香族ポリカーボネートを製造する時と同様に不活性ガス雰囲気の減圧下あるいはごく微量の不活性ガス気流下で重合を行うのが好ましい。圧力は低いほど、重合の効率は高いが、実用的な範囲を考慮すると概略１〜３０ｋＰａ、好ましくは５〜１５ｋＰａ程度である。この際に結晶化芳香族ポリカーボネートを機械的にあるいは気体流により撹拌しても良い。反応温度、時間については先述の常圧で重合する際と同様な条件で行うことが好ましく採用できる。
【００２９】
以上のごとき固相重合により製造された所望の重合度の芳香族ポリカーボネート樹脂（以下,「ポリカーボネート樹脂」ということがある）は、色相が良く、ゲル成分も少なく成形性に優れたものとなるが、必要に応じて、末端ヒドロキシ基の封鎖反応や溶融粘度の安定化を行うことができ、その方がポリカーボネート樹脂の成形時の熱安定性や、耐久安定性を向上させる上で好ましい。
【００３０】
本発明により製造されるポリカーボネート樹脂は、使用目的により、離型剤、耐熱安定剤、紫外線吸収剤、着色剤、帯電防止剤等の各種添加剤、ガラス繊維、鉱物、フィラーといった無機剤、アラミド繊維などの有機剤、または本発明のポリカーボネート樹脂以外のポリマーを混合し樹脂組成物を得ることができる。その樹脂組成物は成形用樹脂、フィルム、繊維等の用途に使用可能である。
【００３１】
【発明の効果】
本発明の製造方法を用いると、解重合して得られた結晶化芳香族ポリカーボネートの固相重合速度は、加熱結晶化で得られた同程度の固有粘度の結晶化芳香族ポリカーボネートを用いた場合と比較すると非常に速いものとなる。
【００３２】
【実施例】
以下、本発明を実施例により説明するが、本発明は、これらの実施例に限定されるものではない。
【００３３】
１）固有粘度［η］
ジクロロメタン溶液中、２０℃でウベローデ粘度管にて測定した。
【００３４】
２）ガラス転移温度（Ｔｇ）、融点（Ｔｍ）
デュポンインスツルメント ９１０ＤＳＣにより、昇温速度１０℃／分で測定してガラス転移温度Ｔｇ、融点Ｔｍを求めた。また、結晶融解のエンタルピー（ΔＨｍ）は、結晶融解に対応する部分の面積より算出した。また結晶化度はＤＳＣ測定によって得られたΔＨｍと、１００％結晶化芳香族ポリカーボネートのΔＨｍの値、すなわちジャーナル・オブ・ポリマー・サイエンス；パートＢ：ポリマー・フィジクス（Ｊ．Ｐｏｌｙｍ．Ｓｃｉ．：Ｂ：Ｐｏｌｙｍ．Ｐｈｙｓ．）１９７９年第２５巻１５１１〜１５１７ページ記載の１０９．８Ｊ／ｇから（ΔＨｍ／１０９．８Ｊ／ｇ）×１００％として計算した。
【００３５】
３）粘度平均分子量
粘度平均分子量Ｍｖは、上記１）によって求められた固有粘度[η]を元にして、マーク−ホーウインクの粘度式と呼ばれる下記式（２）を用いて算出した。なお、マーク−ホーウインク定数Ｋ、並びにαはシュネル氏の値を採用した。
[η]＝ＫＭｖ^α （２）
（上記式においてＭｖは粘度平均分子量を、Ｋ＝１．２３×１０^-4、α＝０．８３を表す。）
【００３６】
［参考例１：非晶性芳香族ポリカーボネートの合成例］
２，２−ビス（４−ヒドロキシフェニル）プロパン２２８重量部、ジフェニルカーボネート２２３重量部、テトラメチルアンモニウムヒドロキシド０．００９重量部、及びビスフェノールＡジナトリウム塩０．０００１４重量部を攪拌装置、減圧装置及び蒸留塔等を備えた反応装置に仕込み、１８０℃、窒素雰囲気下で３０分攪拌し溶解した。次いで、昇温と同時に徐々に減圧下とし、発生するフェノールを留去しながら反応させ、最終的に２８０℃、０．２ｍｍＨｇとした。この時点で、得られた非晶性芳香族ポリカーボネートの固有粘度［η］は０．３９、粘度平均分子量が１６５００、ガラス転移温度（Ｔｇ）は１４８℃であった。
【００３７】
［実施例１］
上記の参考例１で得られた固有粘度が０．３９の非晶性芳香族ポリカーボネートを粒径２〜３ｍｍに粉砕し、その５０ｇをフェノール／水＝８／２（重量比）からなる１００℃の混合液０．５Ｌ中に３０分間浸漬させた。浸漬後混合液を濾別し、１００℃で１６時間乾燥させて、粒径２〜３ｍｍ、固有粘度［η］０．１７、ガラス転移温度１４８℃、融点２３０．７℃、結晶化度２３．７％の結晶化芳香族ポリカーボネートを得た。
【００３８】
［実施例２］
フェノール／水＝５０／５０にした以外は実施例１と同等の方法で操作を行ったところ、固有粘度［η］０．１９、ガラス転移温度１４９℃、融点２２７．４℃、結晶化度２０．０％の結晶化芳香族ポリカーボネートを得た。
【００３９】
［実施例３］
実施例１で得られた結晶化芳香族ポリカーボネートを内径４０ｍｍの円筒型竪型反応装置に充填し、加熱窒素を線速度にして０．１ｍ／秒で流通させて常圧下で固相重合を開始した。重合温度は２００℃で３時間、２１０℃で３時間、２２０℃で３時間、２３０℃で３時間の順で昇温し、合計１２時間の固相重合反応を行ったところ固有粘度［η］＝０．８２、粘度平均分子量Ｍｖ＝４０５００の芳香族ポリカーボネートが得られた。なお、このとき融着は観測されなかった。
【００４０】
［比較例１］
実施例１と同様の操作を固有粘度が０．１６の非晶性芳香族ポリカーボネートで行ったところ、固有粘度［η］０．１５、融点２２３．１５℃、結晶化度２０．０％の結晶化芳香族ポリカーボネートを得た。
【００４１】
［比較例２］
比較例１で得られた結晶化芳香族ポリカーボネートを内径４０ｍｍの円筒型竪型反応装置に充填し、実施例３と同じ条件で固相重合を行ったところ固有粘度［η］＝０．３８、粘度平均分子量Ｍｖ＝１２６００にしか到達しなかった。
【００４２】
［比較例３］
実施例１と同様の操作を２５℃のアセトン中で行ったところ、結晶化は進行するものの仕込んだ非晶性芳香族ポリカーボネートの８％が微粉となった。また結晶化部分がチップ表層に集中し芯部は非晶のまま残ったため、固相重合温度に昇温すると表面クラックから非晶部分が融けだして融着した。
【００４３】
［比較例４］
上記の参考例１で得られた非晶性芳香族ポリカーボネートを２〜３ｍｍに粉砕し、２２０℃に制御された栗本鉄工所製２軸ニーダーＳ２に供給し、滞留時間１０分で混錬と押し出しを行ったがＤＳＣにおいて融点Ｔｍは観測されず結晶化が確認されなかった。[0001]
BACKGROUND OF THE INVENTION
The present invention is a method for producing a crystallized aromatic polycarbonate by crystallizing a relatively high molecular weight amorphous aromatic polycarbonate by contacting with a mixed solution or mixed vapor containing phenols and water, and using the same The present invention relates to a method for producing an aromatic polycarbonate having a high degree of polymerization.
[0002]
[Prior art]
Aromatic polycarbonate is essentially a polymer that is characterized by non-crystallinity, and in order to crystallize this, 1. heat crystallization method, 2. solvent crystallization method, 3. shearing the molten aromatic polycarbonate. Heat shearing crystallization methods are known. Japanese Examined Patent Publication No. 7-094546 discloses a method of heating and holding an amorphous aromatic polycarbonate at a temperature higher than its glass transition temperature (Tg) and lower than the temperature at which it begins to melt. The heat crystallization method merely holds the amorphous aromatic polycarbonate above a certain temperature, but it is known that crystallization is difficult if the intrinsic viscosity of the amorphous aromatic polycarbonate exceeds 0.38. It has been.
[0003]
Similarly, as a solvent crystallization method, in Japanese Patent Publication No. 7-094546, a method in which an amorphous aromatic polycarbonate is dissolved in a solvent and then precipitated and crystallized, or a solvent having a low solubility in an amorphous aromatic polycarbonate For example, a method of immersing in acetone, ethyl acetate, tetrahydrofuran or the like is shown. Although this method allows crystallization in a short time, if the intrinsic viscosity of the amorphous aromatic polycarbonate becomes high, the progress of crystallization becomes difficult and there is a high risk of fusion in the subsequent solid phase polymerization. .
[0004]
Further, as a method of heat shear crystallization, US Pat. No. 5,864,006 discloses that an amorphous aromatic polycarbonate is heated and held in a temperature range of a glass transition temperature (Tg) or more and a melting point (Tm) or less. Although a method for orientation and crystallization by applying force is shown, when the intrinsic viscosity of the aromatic polycarbonate exceeds 0.38, the melt viscosity becomes too high, and the crystallization speed approaches zero as much as possible. Therefore, crystallization was very difficult.
[0005]
[Problems to be solved by the invention]
The object of the present invention is to solve the problems of the conventional method as described above, and to crystallize an amorphous aromatic polycarbonate having an intrinsic viscosity of more than 0.38, which has been conventionally difficult to crystallize, thereby crystallizing the aromatic polycarbonate. It is to provide a manufacturing method.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above-mentioned problems, the present inventors have made efficient use of a solvent that has been considered unfavorable in conventional solvent crystallization, that is, a solvent that depolymerizes amorphous aromatic polycarbonate. Finding a method of producing a crystallized aromatic polycarbonate that is crystallized and difficult to fuse, and the use of the crystallized aromatic crystallized aromatic polycarbonate results in a very rapid polymerization rate in subsequent solid-phase polymerization The present invention has been achieved.
[0007]
That is, in the first invention in the present invention, the main repeating unit is represented by the following formula (1):
[0008]
[Chemical 2]

[0009]
[In the above formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or carbon. An aryl group having 6 to 20 carbon atoms, W is an alkylidene group having 2 to 15 carbon atoms, an alkylene group having 1 to 15 carbon atoms, a cycloalkylidene group having 3 to 15 carbon atoms, a cycloalkylene group having 3 to 15 carbon atoms, An alkylene-arylene-alkylene group having 8 to 20 carbon atoms, an oxygen atom, a sulfur atom, a sulfoxide group, or a sulfone group; An amorphous aromatic polycarbonate having an intrinsic viscosity [η] of more than 0.38 to 0.5 represented by the formula (1) is brought into contact with a mixed liquid or mixed steam containing phenols and water, and the intrinsic viscosity [η] is 0.05. A crystallized aromatic polycarbonate production method for obtaining a crystallized aromatic polycarbonate having a crystallized aromatic polycarbonate of .about.0.38. The second invention relates to a crystallized aromatic polycarbonate obtained by the above production method having a glass transition temperature (Tg) or higher. This is a method for producing an aromatic polycarbonate resin which is heated at a temperature lower than the melting point (Tm) at normal pressure and under an inert gas stream or under reduced pressure to increase the degree of polymerization.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the amorphous aromatic polycarbonate in the production method of the present invention, the main repeating unit is represented by the following formula (1).
[0011]
[Chemical 3]

[0012]
[In the above formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or carbon. An aryl group having 6 to 20 carbon atoms, W is an alkylidene group having 2 to 15 carbon atoms, an alkylene group having 1 to 15 carbon atoms, a cycloalkylidene group having 3 to 15 carbon atoms, a cycloalkylene group having 3 to 15 carbon atoms, An alkylene-arylene-alkylene group having 8 to 20 carbon atoms, an oxygen atom, a sulfur atom, a sulfoxide group, or a sulfone group; ]
It is represented by In the above formula (1), R ₁ , R ₂ , R ₃ , and R ₄ are specifically hydrogen atoms; halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms; methyl groups, ethyl groups, propyl groups, butyls Group, C1-C10 alkyl groups, such as a hexyl group; C7-C20 aralkyl groups, such as a benzyl group and a phenethyl group; C6-C20 aryl groups, such as a phenyl group and a naphthyl group. W is specifically an alkylidene group having 2 to 15 carbon atoms such as an ethylidene group, a propylidene group or a butylidene group; an alkylene group having 1 to 15 carbon atoms such as a methylene group, an ethylene group, a propylene group or a butylene group; Group, a cycloalkylidene group having 3 to 15 carbon atoms such as cyclohexylidene group; a cycloalkylene group having 3 to 15 carbon atoms such as 1,3-cyclopentylene group and 1,4-cyclohexylene group, m-diiso C8-C20 alkylene-arylene-alkylene groups such as a pyropyrenephenylene group and p-diisopropylopyrenephenylene group; ether groups, sulfoxide groups, sulfide groups, sulfone groups and the like.
[0013]
These amorphous aromatic polycarbonates are preferably produced by a known melt polymerization method or a solid phase polymerization method in which an aromatic dihydroxy compound and a carbonic acid diester are heated and melt-reacted, more preferably in the presence of a transesterification catalyst. Is done.
[0014]
Examples of the aromatic dihydroxy compound used in the present invention include 2,2-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as bisphenol A), bis (2-hydroxyphenyl) methane, and 1,1-bis. (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) propane, 2,2-bis (2-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) ) Propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxyphenyl) Pentane, 3,3-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone and the aromatic ring, for example, an alkyl group, an aryl group those substituted. These may be used alone or in combination of two or more. At least one of these compounds is preferably a compound containing 2,2-bis (4-hydroxyphenyl) propane, and more preferably only 2,2-bis (4-hydroxyphenyl) propane is used. .
[0015]
Examples of the carbonic acid diester include diphenyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, and dibutyl carbonate. These may be used alone or in combination of two or more. Furthermore, it is preferable to use diphenyl carbonate.
[0016]
In the present invention, those having an intrinsic viscosity [η] of more than 0.38 to 0.5, preferably more than 0.38 to 0.45 are preferably used. The intrinsic viscosity [η] referred to in the present invention is a value calculated from the viscosity measured at a temperature of 20 ° C. in a dichloromethane solution. If the intrinsic viscosity [η] of the amorphous aromatic polycarbonate used in the present invention exceeds 0.5, it is very difficult to obtain an aromatic polycarbonate having a sufficient crystallinity, which is not preferable. If it is 0.38 or less, the effect of rapid solid-phase polymerization of the present invention is not exhibited.
[0017]
The amorphous aromatic polycarbonate used in the present invention is in a completely amorphous state with a crystallinity of 0% or rich in amorphousness close to it. If necessary, the amorphous polycarbonate is preferably selected by adjusting the particle size and shape by pulverization and classification.
[0018]
Phenols used in the present invention include phenols such as phenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-cresol, m-cresol, p-cresol, 1-naphthol, 2-naphthol and the like. Can be used.
[0019]
Among these, methanol, ethanol, 1-propanol, 2-propanol and phenol are preferable, and phenol is particularly preferable. When a liquid or gas of an organic compound other than a monohydroxy compound is used, only the surface of the amorphous aromatic polycarbonate is crystallized, and a lot of amorphous portions remain inside, so that a problem of easy fusion occurs. In addition, only the crystallized portion of the surface is peeled off, and the problem of easily generating fine powder is likely to occur.
[0020]
Next, in the present invention, the amorphous aromatic polycarbonate is crystallized by contacting with a mixed solution or mixed steam of phenols and water. The mixed vapor means that when both phenols and water are completely gaseous, when at least one of them is present as a gas under a condition that is relatively liquefiable, or most other than a trace amount corresponding to the vapor pressure. Includes the case where it exists as a liquid. The mixed liquid or mixed vapor of phenols and water is preferably a liquid. The temperature at which the mixed liquid or mixed vapor and the amorphous aromatic polycarbonate are brought into contact can be preferably selected from 40 ° C. or higher and 150 ° C. or lower, which is the temperature at which the mixed liquid or mixed vapor does not solidify, more preferably 80 ° C to 110 ° C. This temperature range is particularly preferred when phenol is used. If the temperature is lower than the above temperature range, crystallization of the crystallized aromatic polycarbonate is not sufficient, or depolymerization does not proceed to 0.05 to 0.38 or less which is an intrinsic viscosity range which is easy to crystallize, which is not preferable. On the other hand, a temperature higher than the above temperature range is not preferable because the crystallized aromatic polycarbonate is remarkably dissolved in a mixed liquid or mixed vapor. The content of phenols in the mixed solution or mixed steam is 10% by weight to 90% by weight, and 50% by weight to 80% by weight is preferably used. If the phenol content is outside this range, the aromatic polycarbonate is insufficiently depolymerized, insufficiently crystallized, or dissolved in the mixture when the mixture or vapor is a mixture. Becomes conspicuous, making it difficult to achieve the objective. The contact time of the amorphous aromatic polycarbonate with the mixed solution or mixed vapor is preferably in the range of 1 minute to 120 minutes, and crystallization does not proceed sufficiently in a shorter time, and the mixed liquid or mixed vapor is used in a long time. This is not preferable because the amount of dissolution and the like is remarkably increased. The crystallization treatment time determined in this way is, for example, about 1/10 to 1/100 of the time required for the heat crystallization method, which is a very short time. The crystallized aromatic polycarbonate thus obtained is crystallized uniformly to the inside and the molecular weight is reduced from the beginning, but the intrinsic viscosity is spontaneously controlled in the range of 0.05 to 0.38. Compared with the crystallized aromatic polycarbonate having the same intrinsic viscosity obtained by the heat crystallization method, the solid phase polymerization rate becomes abnormally high.
[0021]
In the method of the present invention, the following method can be exemplified as a method of bringing the amorphous aromatic polycarbonate into contact with a mixed solution or mixed vapor of phenols and water.
(I) A method in which amorphous aromatic polycarbonate is pulverized and classified and then immersed in a mixed solution or mixed steam of heated phenols and water.
(II) A method in which an amorphous aromatic polycarbonate is granulated after being immersed in a mixed solution or mixed steam of heated phenolic water or while being immersed.
(III) A method in which an amorphous aromatic polycarbonate is solidified while being granulated and then immersed in a mixed solution or steam of heated phenols and water.
(IV) A method of exposing the above (I) to a mixed vapor of phenols and water instead of a mixed solution or mixed vapor.
(V) A method of performing the above (I) to (IV) under pressure using an autoclave or the like.
[0022]
When the amorphous aromatic polycarbonate is brought into contact with the mixed liquid or mixed vapor, the amount of the mixed liquid or mixed vapor and the amorphous aromatic polycarbonate is not limited, but the amorphous aromatic polycarbonate is mixed in a weight ratio: mixed liquid. Or mixed steam = 1: 0.5-1: 500 is preferable. Outside the above range, the amorphous aromatic polycarbonate is agglomerated and the internal crystallization becomes difficult or dissolves, and the yield of the crystallized aromatic polycarbonate is lowered.
[0023]
The crystallized aromatic polycarbonate thus produced can then be used to proceed with the solid state polymerization reaction. It is also a preferred embodiment to use a compressed granular molded body obtained by compression molding the crystallized aromatic polycarbonate. In order to maintain the solid state in the solid state polymerization reaction, the crystallized aromatic polycarbonate is heated at a temperature not lower than the glass transition temperature (Tg) and lower than the melting point (Tm) at normal pressure and under an inert gas stream or under reduced pressure. It is preferable to increase the degree of polymerization. Thus, a high molecular weight aromatic polycarbonate resin having a desired molecular weight is obtained.
[0024]
Polymerization under normal pressure is preferably performed under an inert gas stream as described above. Examples of the inert gas to be circulated in the solid phase polymerization tank include crystallized aromatic polycarbonate, its raw material, and helium, argon, nitrogen, carbon dioxide gas, etc. that are inert to the compound distilled in the reaction. it can. The solid phase polymerization temperature is preferably carried out at a glass transition temperature (Tg) or higher and lower than a melting point (Tm) of the crystallized aromatic polycarbonate. When the solid phase polymerization temperature is less than Tg, the solid phase polymerization reaction hardly occurs. If the solid-phase polymerization temperature is Tm or higher, the crystallized aromatic polycarbonate is fused, which causes problems such as clogging of the reaction tank and piping, which is not preferable. As a more specific preferred embodiment, on the premise that the temperature is within the above range, an inert gas having a temperature of 140 to 350 ° C. is circulated at a flow rate of 0.1 NL / min or more per 1 kg of the crystallized aromatic polycarbonate. To be implemented. Even within the temperature range of the above inert gas, 145 to 330 ° C is more preferable, and 150 to 300 ° C is particularly preferable. For example, when an aromatic polycarbonate is produced by melt polycondensation of 2,2-bis (4-hydroxyphenyl) propane and diphenyl carbonate, it is preferable to pass an inert gas at 150 to 300 ° C., 160 to 280 ° C. Is particularly preferred. In addition, since the melting point of the crystallized aromatic polycarbonate increases as the degree of polymerization increases, a method in which the solid-state polymerization temperature is sequentially increased as the melting point increases is preferably used.
[0025]
The flow rate of the inert gas is preferably from 0.1 NL / min to 100 NL / min, particularly preferably from 1 to 50 NL / min, per kg of the aromatic polycarbonate prepolymer or the compressed granular molded body. When the flow rate is smaller than the above range, the progress of the solid phase polymerization reaction is slow, and the polymerization time is prolonged, which is not preferable. When the amount of circulation is larger than the above range, the heat energy cost increases, which is not preferable.
[0026]
Usually, several hours to several tens of hours are employed as the time required for the solid phase polymerization. If the polymerization time is too long, an apparatus used for solid phase polymerization becomes large, which is not preferable from the viewpoint of equipment production cost. There is also a problem that the hue of the aromatic polycarbonate resin deteriorates. On the other hand, if the polymerization time is short, an aromatic polycarbonate resin having a desired degree of polymerization cannot be obtained, resulting in a resin having insufficient mechanical strength. If necessary, the crystallized aromatic polycarbonate may be mechanically stirred during solid phase polymerization or may be stirred by a gas flow.
[0027]
There is no particular limitation on the type of the solid phase polymerization tank used in the present invention, but a cylindrical vertical reactor having an inert gas inlet at the bottom and an inert gas outlet at the top, a rotary reactor Etc. can be illustrated as a preferable form.
[0028]
When solid phase polymerization is carried out under reduced pressure, it is preferred to carry out the polymerization under reduced pressure in an inert gas atmosphere or in a very small amount of inert gas flow as in the case of producing an amorphous aromatic polycarbonate. The lower the pressure is, the higher the polymerization efficiency is. However, considering the practical range, it is about 1 to 30 kPa, preferably about 5 to 15 kPa. At this time, the crystallized aromatic polycarbonate may be stirred mechanically or by a gas flow. Regarding the reaction temperature and time, it is preferable to carry out the reaction under the same conditions as those used for polymerization at normal pressure described above.
[0029]
An aromatic polycarbonate resin having a desired degree of polymerization (hereinafter sometimes referred to as “polycarbonate resin”) produced by solid-phase polymerization has a good hue, a small gel component, and excellent moldability. If necessary, the terminal hydroxy group blocking reaction and the melt viscosity can be stabilized, and this is preferable for improving the heat stability and durability stability of the polycarbonate resin.
[0030]
Depending on the purpose of use, the polycarbonate resin produced according to the present invention can be used in various additives such as mold release agents, heat stabilizers, UV absorbers, colorants, antistatic agents, inorganic agents such as glass fibers, minerals and fillers, and aramid fibers. A resin composition can be obtained by mixing an organic agent such as the above or a polymer other than the polycarbonate resin of the present invention. The resin composition can be used for applications such as molding resins, films and fibers.
[0031]
【The invention's effect】
When the production method of the present invention is used, the rate of solid-phase polymerization of a crystallized aromatic polycarbonate obtained by depolymerization is the same as that when a crystallized aromatic polycarbonate of the same intrinsic viscosity obtained by heat crystallization is used. Compared with, it is very fast.
[0032]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
[0033]
1) Intrinsic viscosity [η]
It measured in the dichloromethane solution at 20 degreeC with the Ubbelohde viscosity tube.
[0034]
2) Glass transition temperature (Tg), melting point (Tm)
The glass transition temperature Tg and the melting point Tm were determined by DuPont Instrument 910DSC at a temperature elevation rate of 10 ° C./min. Moreover, the enthalpy (ΔHm) of crystal melting was calculated from the area of the portion corresponding to crystal melting. The crystallinity is ΔHm obtained by DSC measurement and ΔHm of 100% crystallized aromatic polycarbonate, that is, Journal of Polymer Science; Part B: Polymer Physics (J. Polym. Sci .: B). : Polym.Phys.) It was calculated as (ΔHm / 109.8 J / g) × 100% from 109.8 J / g described in Vol.
[0035]
3) Viscosity average molecular weight The viscosity average molecular weight Mv was calculated based on the intrinsic viscosity [η] determined in 1) above, using the following formula (2) called the Mark-Hou ink viscosity formula. For the Mark-Houwink constant K and α, Schnell values were adopted.
[η] = KMv ^α (2)
(In the above formula, Mv represents the viscosity average molecular weight, K = 1.23 × 10 ⁻⁴ , α = 0.83)
[0036]
[Reference Example 1: Synthesis Example of Amorphous Aromatic Polycarbonate]
228 parts by weight of 2,2-bis (4-hydroxyphenyl) propane, 223 parts by weight of diphenyl carbonate, 0.009 part by weight of tetramethylammonium hydroxide, and 0.00014 part by weight of bisphenol A disodium salt were stirred and decompressed. And charged in a reactor equipped with a distillation column and the like, and stirred for 30 minutes in a nitrogen atmosphere at 180 ° C. to dissolve. Next, the pressure was gradually reduced at the same time as raising the temperature, and the reaction was carried out while distilling off the generated phenol. At this time, the obtained amorphous aromatic polycarbonate had an intrinsic viscosity [η] of 0.39, a viscosity average molecular weight of 16,500, and a glass transition temperature (Tg) of 148 ° C.
[0037]
[Example 1]
The amorphous aromatic polycarbonate having an intrinsic viscosity of 0.39 obtained in the above Reference Example 1 is pulverized to a particle size of 2 to 3 mm, and 50 g thereof is 100 ° C. consisting of phenol / water = 8/2 (weight ratio). For 30 minutes. After immersion, the mixed solution was filtered off and dried at 100 ° C. for 16 hours, and the particle size was 2 to 3 mm, the intrinsic viscosity [η] was 0.17, the glass transition temperature was 148 ° C., the melting point was 230.7 ° C., and the crystallinity was 23. 7% of crystallized aromatic polycarbonate was obtained.
[0038]
[Example 2]
An operation was carried out in the same manner as in Example 1 except that phenol / water = 50/50, and an intrinsic viscosity [η] of 0.19, a glass transition temperature of 149 ° C., a melting point of 227.4 ° C., and a crystallinity of 20 0.0% crystallized aromatic polycarbonate was obtained.
[0039]
[Example 3]
The crystallized aromatic polycarbonate obtained in Example 1 is filled into a cylindrical vertical reactor having an inner diameter of 40 mm, and heated nitrogen is allowed to flow at a linear velocity of 0.1 m / second to initiate solid-phase polymerization under normal pressure. did. The polymerization temperature was 200 ° C. for 3 hours, 210 ° C. for 3 hours, 220 ° C. for 3 hours, and 230 ° C. for 3 hours in order, and the solid state polymerization reaction was carried out for a total of 12 hours. = 0.82 and an aromatic polycarbonate having a viscosity average molecular weight Mv = 40500 was obtained. At this time, no fusion was observed.
[0040]
[Comparative Example 1]
When the same operation as in Example 1 was performed on an amorphous aromatic polycarbonate having an intrinsic viscosity of 0.16, crystals having an intrinsic viscosity [η] of 0.15, a melting point of 223.15 ° C., and a crystallinity of 20.0% were obtained. A aromatic aromatic polycarbonate was obtained.
[0041]
[Comparative Example 2]
The crystallized aromatic polycarbonate obtained in Comparative Example 1 was charged into a cylindrical vertical reactor having an inner diameter of 40 mm, and solid phase polymerization was performed under the same conditions as in Example 3. As a result, intrinsic viscosity [η] = 0.38, The viscosity average molecular weight Mv reached only 12600.
[0042]
[Comparative Example 3]
When the same operation as in Example 1 was performed in acetone at 25 ° C., although crystallization proceeded, 8% of the prepared amorphous aromatic polycarbonate became fine powder. Further, since the crystallized portion was concentrated on the chip surface layer and the core portion remained amorphous, when the temperature was raised to the solid phase polymerization temperature, the amorphous portion melted from the surface crack and fused.
[0043]
[Comparative Example 4]
The amorphous aromatic polycarbonate obtained in the above Reference Example 1 is pulverized to 2 to 3 mm and supplied to the Kurimoto Iron Works 2-axis kneader S2 controlled at 220 ° C., and kneaded and extruded in a residence time of 10 minutes. However, the melting point Tm was not observed by DSC, and crystallization was not confirmed.

Claims (10)

The main repeating unit is the following formula (1)

[In the above formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or carbon. An aryl group having 6 to 20 carbon atoms, W is an alkylidene group having 2 to 15 carbon atoms, an alkylene group having 1 to 15 carbon atoms, a cycloalkylidene group having 3 to 15 carbon atoms, a cycloalkylene group having 3 to 15 carbon atoms, An alkylene-arylene-alkylene group having 8 to 20 carbon atoms, an oxygen atom, a sulfur atom, a sulfoxide group, or a sulfone group; ] An amorphous aromatic polycarbonate having an intrinsic viscosity [η] of more than 0.38 to 0.5 represented by the following formula is brought into contact with a mixed liquid or mixed steam containing phenols and water, and the intrinsic viscosity [η] is 0.05. A process for producing a crystallized aromatic polycarbonate to obtain a crystallized aromatic polycarbonate of ~ 0.38. The method for producing a crystallized aromatic polycarbonate according to claim 1, wherein the mixed solution or mixed vapor containing the phenol and water is a liquid. The method for producing a crystallized aromatic polycarbonate according to claim 1 or 2, wherein the phenol is phenol.   The method for producing a crystallized aromatic polycarbonate according to any one of claims 1 to 3, wherein the temperature of the mixed liquid or mixed steam when being brought into contact with the mixed liquid or mixed steam is 40 ° C to 150 ° C.   The method for producing a crystallized aromatic polycarbonate according to any one of claims 1 to 3, wherein the temperature of the mixed liquid or mixed steam when contacting the mixed liquid or mixed steam is 80C to 110C. The method for producing a crystallized aromatic polycarbonate according to any one of claims 1 to 5, wherein the content of phenols in the mixed solution or mixed steam is 10 wt% or more and 90 wt% or less. The method for producing a crystallized aromatic polycarbonate according to any one of claims 1 to 5, wherein the content of phenols in the mixed solution or the mixed steam is 50 wt% or more and 80 wt% or less.   The method for producing a crystallized aromatic polycarbonate according to any one of claims 1 to 7, wherein the contact time between the mixed liquid or the mixed vapor and the amorphous aromatic polycarbonate is 1 minute or more and 120 minutes or less.   The method for producing a crystallized aromatic polycarbonate according to any one of claims 1 to 8, wherein the particle size of the amorphous aromatic polycarbonate to be brought into contact with the mixed liquid or mixed vapor is 0.1 to 5 mm.   The crystallized aromatic polycarbonate obtained by the production method according to any one of claims 1 to 9, at a temperature not lower than the glass transition temperature (Tg) and lower than the melting point (Tm), at normal pressure and in an inert gas stream A process for producing an aromatic polycarbonate resin which is heated under reduced pressure or under reduced pressure to increase the degree of polymerization.