JP4172280B2 - Polyphenylene sulfide film and method for producing the same - Google Patents

Description

【００１２】
耐熱性の点から、上記構造式で示される繰返し単位を７０モル％以上、特に９０モル％以上を含む重合体であることが好ましい。またＰＰＳ樹脂はその繰り返し単位の３０モル％以下を、下記の構造式を有する繰り返し単位等で構成することが可能である。
【００１３】
【化２】

【００１４】
本発明で用いられるＰＰＳ樹脂は、例えば通常公知の方法即ち特公昭４５−３３６８号公報に記載される比較的分子量の小さな重合体を得る方法或いは特公昭５２−１２２４０号公報や特開昭６１−７３３２号公報に記載される比較的分子量の大きな重合体を得る方法などによって製造できる。本発明において上記の様に得られたＰＰＳ樹脂を空気中加熱による架橋／高分子量化、窒素などの不活性ガス雰囲気下あるいは減圧下での熱処理、有機溶媒、熱水、酸水溶液などによる洗浄、酸無水物、アミン、イソシアネート、官能基含有ジスルフィド化合物などの官能基含有化合物による活性化など種々の処理を施した上で使用することも可能であり、さらに、これらの処理を２種類以上行うことももちろん可能である。また、これらの処理を行ったＰＰＳ樹脂を、２種類以上の混合で使用することももちろん可能であり、２種類以上の混合で使用する場合の具体的方法として、空気中加熱により架橋したＰＰＳ樹脂と熱処理を行っていないＰＰＳ樹脂の混合、酸水溶液による洗浄を行ったＰＰＳ樹脂と有機溶媒による洗浄を行ったＰＰＳ樹脂の混合、有機溶媒で洗浄したＰＰＳ樹脂と有機溶媒で洗浄を行っていないＰＰＳ樹脂の混合などが例示できる。
【００１５】
本発明で用いられるＰＰＳ樹脂の分子量については、特に制限はないが、後述のスピノーダル分解する際の条件に関連するため、適宜選択する必要があり、この分子量に関するパラメーターである溶融粘度については、通常５〜１，０００Pa・s（３２０℃、剪断速度１０００ｓｅｃ^-1）のものが使用されるが、中でも１０〜５００Pa・sのものが好ましく用いられる。
【００１６】
ＰＰＳ樹脂の加熱による架橋／高分子量化する場合の具体的方法としては、空気、酸素などの酸化性ガス雰囲気下あるいは前記酸化性ガスと窒素、アルゴンなどの不活性ガスとの混合ガス雰囲気下で、所定の温度において希望する溶融粘度が得られるまで加熱を行う方法が例示できる。加熱処理温度は通常、１７０〜２８０℃が選択され、好ましくは２００〜２７０℃であり、時間は通常０．５〜１００時間が選択され、好ましくは２〜５０時間であるが、この加熱処理温度と時間を適宜コントロールすることにより目標とする粘度レベルを得ることができる。加熱処理の装置は減圧仕様、またはシール性の高い仕様の通常の熱風乾燥機でもまた回転式あるいは撹拌翼付の加熱装置であってもよいが、効率よくしかもより均一に処理する場合は回転式あるいは撹拌翼付の加熱装置を用いるのがより好ましい。
【００１７】
ＰＰＳ樹脂を窒素などの不活性ガス雰囲気下あるいは減圧下で熱処理する場合の具体的方法としては、窒素などの不活性ガス雰囲気下あるいは減圧下で、加熱処理温度１５０〜２８０℃、好ましくは２００〜２７０℃、加熱時間は０．５〜１００時間、好ましくは２〜５０時間加熱処理する方法が例示できる。加熱処理の装置は静置型の加熱装置でもまた回転式あるいは撹拌翼付の加熱装置であってもよいが、効率よくしかもより均一に処理する場合は回転式あるいは撹拌翼付の加熱装置を用いるのがより好ましい。
【００１８】
ＰＰＳ樹脂を有機溶媒で洗浄する場合の具体的方法としては以下の方法が例示できる。すなわち、洗浄に用いる有機溶媒としては、ＰＰＳ樹脂を分解する作用などを有しないものであれば特に制限はないが、例えばＮ−メチルピロリドン、ジメチルホルムアミド、ジメチルアセトアミドなどの含窒素極性溶媒、ジメチルスルホキシド、ジメチルスルホンなどのスルホキシド・スルホン系溶媒、アセトン、メチルエチルケトン、ジエチルケトン、アセトフェノンなどのケトン系溶媒、ジメチルエーテル、ジプロピルエーテル、テトラヒドロフランなどのエーテル系溶媒、クロロホルム、塩化メチレン、トリクロロエチレン、２塩化エチレン、ジクロルエタン、テトラクロルエタン、クロルベンゼンなどのハロゲン系溶媒、メタノール、エタノール、プロパノール、ブタノール、ペンタノール、エチレングリコール、プロピレングリコール、フェノール、クレゾール、ポリエチレングリコールなどのアルコール・フェノール系溶媒、ベンゼン、トルエン、キシレンなどの芳香族炭化水素系溶媒などがあげられる。これらの有機溶媒のなかでＮ−メチルピロリドン、アセトン、ジメチルホルムアミド、クロロホルムなどの使用が好ましい。また、これらの有機溶媒は、１種類または２種類以上の混合で使用することもできる。有機溶媒による洗浄の方法としては、有機溶媒中にＰＰＳ樹脂を浸漬せしめるなどの方法があり、必要により適宜撹拌または加熱することも可能である。有機溶媒でＰＰＳ樹脂を洗浄する際の洗浄温度については特に制限はなく、常温〜３００℃程度の任意の温度が選択できる。洗浄温度が高くなるほど洗浄効率が高くなる傾向があるが、通常は常温〜１５０℃の洗浄温度で十分効果が得られる。
【００１９】
また有機溶媒洗浄を施されたＰＰＳ樹脂は残留している有機溶媒を除去するため、水または温水で数回洗浄することが好ましい。
【００２０】
ＰＰＳ樹脂を熱水で処理する場合の具体的方法としては以下の方法が例示できる。すなわち熱水洗浄によるＰＰＳ樹脂の好ましい化学的変性の効果を発現するため、使用する水は蒸留水あるいは脱イオン水であることが好ましい。熱水処理の操作は、通常、所定量の水に所定量のＰＰＳ樹脂を投入し、常圧で或いは圧力容器内で加熱、撹拌することにより行われる。ＰＰＳ樹脂と水との割合は、水の多いほうが好ましいが、通常、水１リットルに対し、ＰＰＳ樹脂２００ｇ以下の浴比が選択される。
【００２１】
ＰＰＳ樹脂を酸処理する場合の具体的方法としては以下の方法が例示できる。
【００２２】
すなわち、酸または酸の水溶液にＰＰＳ樹脂を浸漬せしめるなどの方法があり、必要により適宜撹拌または加熱することも可能である。用いられる酸はＰＰＳ樹脂を分解する作用を有しないものであれば特に制限はなく、ギ酸、酢酸、プロピオン酸、酪酸などの脂肪族飽和モノカルボン酸、クロロ酢酸、ジクロロ酢酸などのハロ置換脂肪族飽和カルボン酸、アクリル酸、クロトン酸などの脂肪族不飽和モノカルボン酸、安息香酸、サリチル酸などの芳香族カルボン酸、シュウ酸、マロン酸、コハク酸、フタル酸、フマル酸などのジカルボン酸、硫酸、リン酸、塩酸、炭酸、珪酸などの無機酸性化合物などがあげられる。中でも酢酸、塩酸がより好ましく用いられる。酸処理を施されたＰＰＳ樹脂は残留している酸または塩などを除去するため、水または温水で数回洗浄することが好ましい。また洗浄に用いる水は、酸処理によるＰＰＳ樹脂の好ましい化学的変性の効果を損なわない意味で蒸留水、脱イオン水であることが好ましい。
【００２３】
本発明で用いられるポリエチレンテレフタレートを主たる構成単位とするポリエステル樹脂（以下ＰＥＴ樹脂と略す場合がある）は、ポリエチレンテレフタレート樹脂のホモポリマが最も好ましいが、テレフタル酸成分の一部をイソフタル酸、５−ナトリウムスルホイソフタル酸、２，６−ナフタレンジカルボン酸、ジフェノキシエタンジカルボン酸、アジピン酸、セバシン酸、アゼライン酸、ドデカンジカルボン酸等の一種またはそれ以上で置換したものでもよく、また、エチレングリコールの一部を１，４−ブタンジオール、プロピレングリコール、ネオペンチルグリコール、ヘキサメチレングリコール、ペンタメチレングリコール、１，４−シクロヘキサンジメタノール、グリセリン、ペンタエリスリトール、ポリエチレングリコール、ポリテトラメチレングリコール等の一種またはそれ以上で置換したものでもよい。この場合、共重合率は１５モル％以下の範囲とするのが望ましく、さらには５モル％以下の範囲とするのがより望ましい。
【００２４】
本発明で用いられるＰＥＴ樹脂の分子量については、特に制限がないが、後述のスピノーダル分解する際の条件に関連するため、適宜選択する必要があり、この分子量に関するパラメーターである極限粘度については、通常は０．６以上（２５℃、オルソクロロフェノール溶液）のものが使用されるが、中でも０．７以上のものが好ましく用いられる。上限としては１．５以下であることが好ましい。
【００２５】
本発明のポリフェニレンスルフィドフィルムは、ＰＰＳ樹脂とポリエチレンテレフタレートを主たる構成単位とするポリエステル樹脂を含んでなるものであり、かつ該ポリフェニレンスルフィドフィルムは、前記ポリフェニレンスルフィド樹脂と前記ポリエステル樹脂が構造周期０．００１μｍ〜２μｍの両相連続構造、または粒子間距離０．００１μｍ〜２μｍの分散構造を形成していることが必要である。かかる構造となるポリフェニレンスルフィドフィルムを得る方法としては、後述のスピノーダル分解を利用する方法が好ましく、さらには後述の剪断場依存型相溶解・相分解を利用する方法が、さらなる微細な構造制御を容易にすることからより好ましく用いられる。
【００２６】
以下、一般に２成分の樹脂からなるポリマーアロイにおける構造制御方法を説明する。２成分の樹脂からなるポリマーアロイには、これらの組成に対して、ガラス転移温度以上、熱分解温度以下の実用的な全領域において相溶する相溶系や、逆に全領域で非相溶となる非相溶系や、ある領域で相溶し、別の領域で相分離状態となる、部分相溶系があり、さらにこの部分相溶系には、その相分離状態の条件によってスピノーダル分解によって相分離するものと、核生成と成長によって相分離するものがある。
【００２７】
スピノーダル分解による相分離とは、異なる２成分の樹脂組成および温度に対する相図においてスピノーダル曲線の内側の不安定状態で生じる相分離のことを指し、また核生成と成長による相分離とは、該相図においてバイノーダル曲線の内側であり、かつスピノーダル曲線の外側の準安定状態で生じる相分離のことを指す。
【００２８】
かかるスピノーダル曲線とは、組成および温度に対して、異なる２成分の樹脂を混合した場合、相溶した場合の自由エネルギーと相溶しない２相における自由エネルギーの合計との差（ΔＧｍｉｘ）を濃度（φ）で二回偏微分したもの（∂²ΔＧmix／∂φ²）が０となる曲線のことであり、またスピノーダル曲線の内側では、∂²ΔＧmix／∂φ²＜０の不安定状態であり、外側では∂²ΔＧmix／∂φ²＞０である。
【００２９】
またかかるバイノーダル曲線とは、組成および温度に対して、系が相溶する領域と相分離する領域の境界の曲線のことである。
【００３０】
ここで本発明における相溶する場合とは、分子レベルで均一に混合している状態のことであり、具体的には異なる２成分の樹脂を主成分とする相がいずれも０．００１μｍ以上の相構造を形成していない場合を指し、また、非相溶の場合とは、相溶状態でない場合のことであり、すなわち異なる２成分の樹脂を主成分とする相が互いに０．００１μｍ以上の相構造を形成している状態のことを指す。相溶しているか否かは、例えばPolymer Alloys and Blends, Leszek A Utracki, hanser Publishers,Munich Viema New York,P64,に記載の様に、電子顕微鏡、示差走査熱量計（ＤＳＣ）、その他種々の方法によって判断することができる。
【００３１】
詳細な理論によると、スピノーダル分解では、一旦相溶領域の温度で均一に相溶した混合系の温度を、不安定領域の温度まで急速に変化させた場合、系は共存組成に向けて急速に相分離を開始する。その際濃度は一定の波長に単色化され、構造周期（Λｍ）で両分離相が共に連続して規則正しく絡み合った両相連続構造を形成する。この両相連続構造形成後、その構造周期を一定に保ったまま、両相の濃度差のみが増大する過程をスピノーダル分解の初期過程と呼ぶ。
【００３２】
さらに上述のスピノーダル分解の初期過程における構造周期（Λｍ）は熱力学的に下式のような関係がある。
Λｍ〜［│Ｔｓ−Ｔ│／Ｔｓ］^-1/2
（ここでＴｓはスピノーダル曲線上の温度）
ここで本発明でいうところの両相連続構造とは、混合する樹脂の両成分がそれぞれ連続相を形成し、互いに三次元的に絡み合った構造を指す。この両相連続構造の模式図は、例えば「ポリマーアロイ 基礎と応用（第２版）（第１０．１章）」（高分子学会編：東京化学同人）に記載されている。
【００３３】
スピノーダル分解では、この様な初期過程を経た後、波長の増大と濃度差の増大が同時に生じる中期過程、濃度差が共存組成に達した後、波長の増大が自己相似的に生じる後期過程を経て、最終的には巨視的な２相に分離するまで進行する。
【００３４】
ここで本発明にいうところの分散構造とは、片方の樹脂成分が主成分であるマトリックスの中に、もう片方の樹脂成分が主成分である粒子が点在している、いわゆる海島構造のことをさす。
【００３５】
一方、上述の準安定領域での相分離である核生成と成長では、その初期から海島構造である不規則な分散構造が形成されてしまい、それが成長するため最終的に均一な分散構造が得られにくい。
【００３６】
またこれらの両相連続構造もしくは分散構造が、スピノーダル分解によって形成されたものかを確認するためには、規則的な周期構造を有しているかを確認することが有効である。これは例えば、光学顕微鏡観察や透過型電子顕微鏡観察により、両相連続構造が形成されることの確認に加えて、光散乱装置や小角Ｘ線散乱装置を用いて行う散乱測定において、散乱極大が現れることの確認が必要である。なお、光散乱装置、小角Ｘ線散乱装置は最適測定領域が異なるため、構造周期の大きさに応じて適宜選択して用いられる。この散乱測定における散乱極大の存在は、ある周期を持った規則正しい相分離構造を持つ証明であり、その周期Λm は、両相連続構造の場合構造周期に対応し、分散構造の場合粒子間距離に対応する。またその値は、散乱光の散乱体内での波長λ、散乱極大を与える散乱角θm を用いて次式
Λm ＝（λ／２）／ｓｉｎ（θm ／２）
により計算することができる。
【００３７】
ここでＰＰＳ樹脂とＰＥＴ樹脂からなるポリマーアロイにおいて、スピノーダル分解を実現させるためには、ＰＰＳ樹脂とＰＥＴ樹脂を相溶状態とした後、スピノーダル曲線の内側の不安定状態とする。
【００３８】
まずこのＰＰＳ樹脂とＰＥＴ樹脂で相溶状態を実現する方法としては、共通溶媒に溶解後、この溶液から噴霧乾燥、凍結乾燥、非溶媒物質中の凝固、溶媒蒸発によるフィルム生成等の方法により得られる溶媒キャスト法や、溶解度パラメータの差の小さいＰＰＳ樹脂とＰＥＴ樹脂ではその分子量を選ぶことにより溶融混練で相溶化するため、それを利用した溶融混練法が挙げられる。中でも溶媒を用いないドライプロセスである溶融混練による相溶化が、実用上好ましく用いられる。
【００３９】
なお、ＰＰＳ樹脂とＰＥＴ樹脂とを溶融混練する場合、用いる樹脂のいずれもが繊維や三次元成形品などの成形用途に通常用いられるような程度の分子量を有する場合には、高度の剪断下で行うことにより相溶化することができ、いずれか一方もしくは両方の分子量を低下させることにより、より低剪断下で相溶化させることができる。
【００４０】
溶融混練により相溶化させるには、相溶化の条件を満たす限り、通常の単軸押出機、または２軸押出機を用いることができるが、中でも２軸押出機を用いることが好ましい。また相溶化のための温度は、ＰＰＳ樹脂、およびＰＥＴ樹脂の分子量の組み合わせによっても異なり、一概にはいえないが、溶融混練時の温度で相溶となる様、適宜ＰＰＳ樹脂および／またはＰＥＴ樹脂の分子量を低下させた場合の相図に基づき、簡単な予備実験をすることにより設定することができる。
【００４１】
そこで次に溶融混練により相溶状態としたＰＰＳ樹脂とＰＥＴ樹脂からなるポリマーアロイを、スピノーダル曲線の内側の不安定状態として、スピノーダル分解せしめるに際し、不安定状態とするための温度、その他の条件はＰＰＳ樹脂、およびＰＥＴ樹脂の分子量の組み合わせによっても異なり、一概にはいえないが、上記相図に基づき、簡単な予備実験をすることにより設定することができる。この低分子量ＰＰＳとしては、溶融粘度０．０１〜５未満Pa・sのものが好ましく用いられ、また低分子量ＰＥＴとしては、極限粘度０．６未満のものが好ましく用いられ、下限としては用いるＰＰＳ樹脂の分子量により異なるが、配合の結果、フィルムとして用い得る範囲であればよい。
【００４２】
このスピノーダル分解で相分離した後は、所望の構造周期に到達した段階で構造を固定すればよい。かかるスピノーダル分解による構造生成物を固定化する方法としては、急冷等による短時間での相分離相の一方または両方の成分の構造固定や、結晶化によって自由に運動できなくなることを利用した構造固定が挙げられる。また中期過程から後期過程にかける波長の増大過程において、組成や界面張力の影響によっては、片方の相の連続性が途切れ、上述の両相連続構造から分散構造に変化する場合もある。この場合には所望の粒子間距離に到達した段階で構造を固定すればよい。
【００４３】
ここで部分相溶系におけるスピノーダル分解を利用したＰＰＳフィルムの製法としては、フィルム製膜時において、単軸あるいは２軸押出機を用いて溶融混練時の温度において、ＰＰＳ樹脂とＰＥＴ樹脂を一旦相溶解させたポリマーアロイをＴダイから吐出し、吐出後の通常１０〜３０℃の範囲の雰囲気温度で冷却されることによりでスピノーダル分解させ、さらにキャストドラムで冷却固化して該スピノーダル分解の構造を固定化しフィルム化する方法や、吐出後の相溶化状態のポリマーアロイをスピノーダル分解する温度条件下に温調された２つのロール間で成形するポリッシング方法や、カレンダーリング方法で、スピノーダル分解させ所望の構造周期または粒子間距離を有するフィルムを得る方法等があるが、ここでは特に限定されるものではない。またキャストドラムにキャストする際、溶融樹脂をキャストドラムに密着させるには、静電印加を与える方法、エアーナイフを用いる方法、キャストドラムに対向する押さえのドラムを用いる方法等を用いることもできる。また、キャストドラムにキャストする場合は、キャストドラムを吐出口直下に設置し、急冷することが好ましい。さらにはフィルム化用の押出機に供給する前に、予め２軸押出機を用いて相溶化させその構造を凍結させたペレットを用いることがより好ましい。かかるＰＰＳフィルム中では、通常ＰＰＳ樹脂とＰＥＴ樹脂が構造周期０．００１〜２μｍの両相連続構造、または粒子間距離０．００１〜２μｍの分散構造とすることが好ましく、また構造周期０．００１〜１．２μｍの両相連続構造、または粒子間距離０．００１〜１．２μｍの分散構造とすることが優れた機械特性を得られることからより好ましく、さらには構造周期０．００１〜０．８μｍの両相連続構造、または粒子間距離０．００１〜０．８μｍの分散構造とすることがさらに好ましい。
【００４４】
また得られたフィルムを延伸することも可能であり、延伸する方法は、特に制限はなく、逐次２軸延伸、同時２軸延伸でも構わなく、また通常延伸倍率は２〜８倍の間、延伸速度は５００〜５０００％／分の間が多く用いられる。さらに延伸時の熱処理温度は、ＰＰＳ樹脂のガラス転移温度以上で熱処理する方法が通常好ましく用いられるが、ＰＰＳ樹脂とＰＥＴ樹脂が相溶化状態で単一のガラス転移温度を有する場合や、相分解が進行しつつある状態でポリマーアロイ中でのガラス転移温度が、ＰＰＳ樹脂とＰＥＴ樹脂のガラス転移温度間にある場合には、そのポリマーアロイ中のガラス転移温度のうち最も低い温度以上で熱処理することがより好ましい。また該熱処理温度を結晶性樹脂の昇温結晶化温度以下とすることは、結晶性樹脂の結晶化による延伸の阻害を受けにくくする観点から好ましい。この延伸フィルムは、さらに熱処理することによりその構造を安定化させ用いることが好ましい。この安定化のための熱処理温度は、通常ＰＰＳ樹脂のガラス転移温度以上で熱処理する方法が通常好ましく用いられるが、相分離が進行しつつある状態でポリマーアロイ中でのガラス転移温度が、ＰＰＳ樹脂とＰＥＴ樹脂のガラス転移温度間にある場合、そのポリマーアロイ中のガラス転移温度のうち最も低い温度以上で熱処理することがより好ましい。またこの延伸ポリマーアロイフィルムの構造周期や粒子間距離は、延伸により、増大する。かかる延伸ＰＰＳフィルム中では、ＰＰＳ樹脂とＰＥＴ樹脂が構造周期０．００１〜２μｍの両相連続構造、または粒子間距離０．００１〜２μｍの分散構造とすることが必要であり、また構造周期０．００１〜１．２μｍの両相連続構造、または粒子間距離０．００１〜１．２μｍの分散構造とすることが優れた機械特性を得られることから好ましく、さらには構造周期０．００１〜０．８μｍの両相連続構造、または粒子間距離０．００１〜０．８μｍの分散構造とすることがより好ましい。
【００４５】
またこの部分相溶系によるスピノーダル分解の他に、非相溶系においても溶融混練によってスピノーダル分解を誘発すること、例えば溶融混練時等の剪断下で一旦相溶し、非剪断下で再度不安定状態となり相分解するいわゆる剪断場依存型相溶解・相分解によってもスピノーダル分解による相分離が可能であり、この場合においても、上記部分相溶系の場合と同じくスピノーダル分解様式で分解が進行し規則的な両相連続構造を有する。さらにこの剪断場依存型相溶解・相分解は、スピノーダル曲線が剪断場により変化し、不安定状態領域が拡大するため、スピノーダル曲線が変化しない部分相溶系の温度変化による方法に比べて、その同じ温度変化幅においても実質的な過冷却度（│Ｔｓ−Ｔ│）が大きくなり、その結果、上述の関係式におけるスピノーダル分解の初期過程における構造周期を小さくすることが容易となり、構造の微細化が容易となるためより好ましく用いられる。
【００４６】
上記剪断場依存型相溶解・相分解する樹脂の組み合わせとしては、剪断下で相溶し、非剪断下でスピノーダル分解するような組み合わせであり、上述の通常用いられる分子量の範囲ＰＰＳ樹脂とＰＥＴ樹脂からなるポリマーアロイがこれに該当する。
【００４７】
剪断下での溶融混練により相溶化させるには、相溶化する条件を満足させ得る性能を有する限り、通常の単軸押出機、または２軸押出機を用いることができるが、中でも高剪断を賦与できるようスクリューアレンジとした２軸押出機を用いることが好ましい。ここで相溶化する温度、スピノーダル分解するための温度、その他の条件はＰＰＳ樹脂、およびＰＥＴ樹脂の分子量の組み合わせによっても異なり、一概にはいえないが、種々の剪断条件下での相図に基づき、簡単な予備実験をすることにより条件を設定することができる
次に上記剪断下で溶融混練により相溶状態としたＰＰＳ樹脂とＰＥＴ樹脂からなるポリマーアロイを、非剪断下でスピノーダル曲線の内側の不安定状態として、スピノーダル分解せしめるに際し、不安定状態とするための温度、その他の条件は、ＰＰＳ樹脂、およびＰＥＴ樹脂の分子量の組み合わせによっても異なり、一概にはいえないが、種々の剪断条件下での相図に基づき、簡単な予備実験をすることにより設定することができる。この剪断場依存型相溶解・相分解でのスピノーダル分解による、構造の微細化をより効果的に生じさせるためには、上記剪断条件下での相図の変化幅が大きくなるよう、ＰＰＳ樹脂、およびＰＥＴ樹脂の分子量の組み合わせを選択することが好ましい。
【００４８】
このスピノーダル分解で相分離した後は、所望の構造周期に到達した段階で構造を固定すればよい。かかるスピノーダル分解による構造生成物を固定化する方法としては、急冷等による短時間での相分離相の一方または両方の成分の構造固定や、結晶化によって自由に運動できなくなることを利用した構造固定が挙げられる。また中期過程から後期過程にかける波長の増大過程において、組成や界面張力の影響によっては、片方の相の連続性が途切れ、上述の両相連続構造から分散構造に変化する場合もある。この場合には所望の粒子間距離に到達した段階で構造を固定すればよい。
【００４９】
ここで剪断場依存型相溶解・相分解におけるスピノーダル分解を利用したＰＰＳフィルムの製法としては、まず溶融混練時の剪断下によりＰＰＳ樹脂とＰＥＴ樹脂とを相溶化させる必要があり、これには相溶化の条件を満足させ得る性能を有する限り、通常の単軸押出機、または２軸押出機が用いられるが、中でも高剪断を賦与できるようなスクリューアレンジとした２軸押出機を用いることが好ましい。また上記製膜装置の可塑化工程での相溶化を確実に実現させる方法として、予め２軸押出機で相溶化するのに十分な剪断をかけながら、溶融混練し相溶化させ、吐出後氷水中などで急冷し相溶化状態で構造を固定させた材料を用いて製膜する方法などが好ましい例として挙げられる。次にこの剪断下で一旦相溶化させたポリマーアロイは、Ｔダイから吐出後の非剪断下でスピノーダル分解させ、キャストドラムで冷却固化して該スピノーダル分解の構造を固定化しフィルム化する方法や、スピノーダル分解する温度条件下に温調された２つのロール間で成形するポリッシング方法や、カレンダーリング方法で、スピノーダル分解させ所望の構造周期または粒子間距離を有するフィルムを得る方法等があるが、ここでは特に限定されるものではない。またキャストドラムにキャストする際、溶融樹脂をキャストドラムに密着させるには、静電印加を与える方法、エアーナイフを用いる方法、キャストドラムに対向する押さえのドラムを用いる方法等を用いることもできる。また、キャストドラムにキャストする場合は、キャストドラムを吐出口直下に設置し、急冷することが好ましい。かかるＰＰＳフィルム中では、ＰＰＳ樹脂とＰＥＴ樹脂が構造周期０．００１〜２μｍの両相連続構造、または粒子間距離０．００１〜２μｍの分散構造とすることが必要であり、また構造周期０．００１〜１．２μｍの両相連続構造、または粒子間距離０．００１〜１．２μｍの分散構造とすることが優れた機械特性を得られることから好ましく、さらには構造周期０．００１〜０．８μｍの両相連続構造、または粒子間距離０．００１〜０．８μｍの分散構造とすることがより好ましい。
【００５０】
また得られたフィルムを延伸することも可能であり、延伸する方法は、特に制限はなく、逐次２軸延伸、同時２軸延伸でも構わなく、また通常延伸倍率は２〜８倍の間、延伸速度は５００〜５０００％／分の間が多く用いられる。さらに延伸時の熱処理温度は、ＰＰＳ樹脂のガラス転移温度以上で熱処理する方法が通常好ましく用いられるが、ＰＰＳ樹脂とＰＥＴ樹脂が相溶化状態で単一のガラス転移温度を有する場合や、相分解が進行しつつある状態でポリマーアロイ中でのガラス転移温度が、ＰＰＳ樹脂とＰＥＴ樹脂のガラス転移温度間にある場合には、そのポリマーアロイ中のガラス転移温度のうち最も低い温度以上で熱処理することがより好ましい。また該熱処理温度を結晶性樹脂の昇温結晶化温度以下とすることは、結晶性樹脂の結晶化による延伸の阻害を受けにくくする観点から好ましい。この延伸フィルムは、さらに熱処理することによりその構造を安定化させ用いることが好ましい。この安定化のための熱処理温度は、通常ＰＰＳ樹脂のガラス転移温度以上で熱処理する方法が通常好ましく用いられるが、相分離が進行しつつある状態でポリマーアロイ中でのガラス転移温度が、ＰＰＳ樹脂とＰＥＴ樹脂のガラス転移温度間にある場合、そのポリマーアロイ中のガラス転移温度のうち最も低い温度以上で熱処理することがより好ましい。またこの延伸ポリマーアロイフィルムの構造周期や粒子間距離は、延伸により、増大する。かかる延伸ＰＰＳフィルム中では、ＰＰＳ樹脂とＰＥＴ樹脂が構造周期０．００１〜２μｍの両相連続構造、または粒子間距離０．００１〜２μｍの分散構造とすることが必要であり、また構造周期０．００１〜１．２μｍの両相連続構造、または粒子間距離０．００１〜１．２μｍの分散構造とすることが優れた機械特性を得られることから好ましく、さらには構造周期０．００１〜０．８μｍの両相連続構造、または粒子間距離０．００１〜０．８μｍの分散構造とすることがより好ましい。
【００５１】
また、本発明を構成する２成分の樹脂からなるポリマーアロイに、さらにポリマーアロイを構成する成分を含むブロックコポリマーやグラフトコポリマーやランダムコポリマーなどのコポリマーである第３成分を添加することは、相分解した相間における界面の自由エネルギーを低下させ、両相連続構造における構造周期や、分散構造における分散粒子間距離の制御を容易にするため好ましく用いられる。この場合通常、かかるコポリマーなどの第３成分は、それを除く２成分の樹脂からなるポリマーアロイの各相に分配されるため、２成分の樹脂からなるポリマーアロイ同様に取り扱うことができる。
【００５２】
本発明でのＰＰＳフィルムを構成する樹脂成分の組成については特に制限はないが、ＰＰＳ樹脂／ＰＥＴ樹脂が、通常９５重量％／５重量％〜５重量％／９５重量％の範囲が好ましく用いられ、さらには９０重量％／１０重量％〜１０重量％／９０重量％の範囲がより好ましく、特に７５重量％／２５重量％〜２５重量％／７５重量％の範囲であれば両相連続構造が比較的得られやすいので好ましく用いられる。
【００５３】
なお、本発明のＰＰＳフィルムには、本発明の目的を損なわない範囲でさらに他の各種の添加剤を含有せしめることもできる。これら他の添加剤としては、例えば、滑剤としての無機粒子および／または架橋有機粒子や、酸化防止剤（リン系、硫黄系など）、紫外線吸収剤、熱安定剤（ヒンダードフェノール系など）、離型剤、帯電防止剤、ブロッキング防止剤、染料および顔料を含む着色剤、抗菌剤等が挙げられる。
【００５４】
これらの添加剤は、本発明のＰＰＳフィルムを製造する任意の段階で配合することが可能であるが、これらの添加剤を、予めポリマーアロイを構成する樹脂のいずれかに添加したマスターバッチを作製し、それを添加する方法が通常好ましく用いられる。
【００５５】
本発明におけるＰＰＳフィルムの厚さは特に限定されないが、通常１９０μｍ以下のものが好ましく、特に１００μｍ以下のものが好ましい。また下限としては特に制限はないが、１０μｍ以上であることが好ましい。
【００５６】
本発明におけるＰＰＳフィルムは、ポリフェニレンスルフィド樹脂の有する優れた耐熱性、機械特性、耐薬品性を有し、かつ優れた靱性を有するポリフェニレンスルフィドフィルムとして各種フィルム用途で好適に用いることができる。
【００５７】
【実施例】
以下、実施例を挙げて本発明の効果をさらに説明する。
【００５８】
参考例（ＰＰＳ樹脂の重合）
（ＰＰＳ−１）
攪拌機付きオートクレーブに硫化ナトリウム９水塩６．００４ｋｇ（２５モル）、およびＮ−メチル−２−ピロリドン（以下ＮＭＰと略す）４．５ｋｇを仕込み、窒素を通じながら徐々に２０５℃まで昇温し、水３．６リットルを留出した。次に反応容器を１８０℃に冷却後、１，４−ジクロロベンゼン３．７１９ｋｇ（２５．３モル）ならびにＮＭＰ３ｋｇを加えて、窒素下に密閉し、２７０℃まで昇温後、２７４℃で１．５時間反応した。冷却後、反応生成物を温水で２回洗浄し、次にこのスラリーを撹拌機付きオートクレーブにイオン交換水３ｋｇと共に入れ１９０℃まで昇温し、１９０℃到達後、室温まで冷却後濾過し、さらに熱湯で数回洗浄した。これを濾過後、８０℃で２４時間減圧乾燥してＰＰＳ樹脂、２．４８ｋｇを得た。このＰＰＳ樹脂は直鎖状であり、溶融粘度８０Pa・s（３２０℃、剪断速度１０００ｓｅｃ^-1）、ガラス転移温度８９℃、結晶融解温度２８０℃であった。
【００５９】
溶融粘度はキャピラリー型溶融粘度測定装置（東洋精機社製ＣＡＰＩＲＯＧＲＡＰＨ−１Ｃ）を用いて、オリフィスＬ／Ｄ＝２０（内径１ｍｍ）で測定し、ガラス転移温度、結晶融解温度はＤＳＣ（ＰＥＲＫＩＮ−ＥＬＭＥＲ社製ＤＳＣ−７）を用いて、昇温速度２０℃／分で測定した。
【００６０】
実施例１〜５
表１記載の組成からなる原料を、押出温度３２０℃に設定し、ニーディングゾーンを２箇所有し、スクリュー回転数を３００ｒｐｍの高速で回転させた２軸スクリュー押出機（池貝工業社製ＰＣＭ−３０）に供給し、ダイから吐出後のガットをすぐに氷水中に急冷し、構造を固定した。本ガットはいずれも透明であり、また該ガットから超薄切片を切り出したサンプルについて、透過型電子顕微鏡にて１０万倍に拡大して観察を行ったが、いずれのサンプルについても０．００１μｍ以上の構造物がみられず相溶化していることを確認した。このことから、本系は、押出温度３２０℃の押出機中の剪断下で相溶化することがわかる。
【００６１】
尚、本系はＬＣＳＴ型相図を有する系であり、押出機の剪断下で相溶領域が拡大したものである。
【００６２】
さらに、上記ダイから吐出後、氷水中に急冷し構造を固定し相溶化した状態のガットを、ストランドカッターに供給し、ペレットを作製した。次にかかるペレットを用いて、再度押出温度３２０℃に設定した先端部にＴダイを有する単軸押出機（φ３０ｍｍ）に供給し、フィルム化を行った。尚、フィルム化においては、Ｔダイの直下（３ｃｍ）に２０℃に温調したハードクロムの鏡面キャストドラムにＴダイの口金から吐出した樹脂をキャストし、８ｋＶの静電印加を加え、キャストドラムに密着させることにより急冷し構造を固定した。さらに、巻き取り速度が一定となる様、毎分５ｍに設定したロール間を通過後、巻き取りロールにより巻き取ることによりフィルムを得た。得られたフィルムの厚みは０．１ｍｍであった。また得られたフィルムは透明であったが、かかるフィルムから超薄切片を切り出したサンプルについて、透過型電子顕微鏡にて１０万倍に拡大して観察を行ったところ、いずれのサンプルも両相連続構造物、若しくは分散構造物が存在することを確認した。さらに得られたフィルムから別途サンプルを切り出し小角Ｘ線散乱もしくは光散乱を用いて測定したところ、いずれのサンプルもピークが観測された。表１には該ピーク位置（θm）から下式で計算した、構造周期（Λm）を記した。なお、分散構造を有する場合の粒子間距離も両相連続構造における構造周期と同じ方法で算出される。
Λm ＝（λ／２）／ｓｉｎ（θm ／２）
以上のことから、フィルム製膜時において、単軸押出機中の剪断下においても相溶化状態が保たれ、Ｔダイから吐出後の非剪断下でスピノーダル分解により相分離し、その後急冷することにより構造が固定されたものと考えられる。
【００６３】
次に該フィルムから、長さ×幅×厚み＝５０ｍｍ×１０ｍｍ×０．１ｍｍのサンプルを切り出し、チャック間距離２０ｍｍ、引張速度１０ｍｍ／分で測定した引張強度、引張伸びの測定結果を表１に記載した。
【００６４】
次に上記得られたフィルムから１００ｍｍ角のサンプルを切り出し、４辺をクリップで固定し、９０℃６０秒間予熱後、９０℃で温調されたオーブン内で、延伸速度２０００％／分、延伸倍率２倍、および４倍で、４辺のクリップを同時２軸延伸となるよう延伸させた。さらにこの延伸フィルムについては、４辺をアルミ製の枠に固定し、１８０℃に温調されたオーブン内を１５秒間通過させることによって熱処理を行い、延伸フィルムの構造の安定化を行った。延伸後のサンプルについても、上記同様に小角Ｘ線散乱もしくは光散乱から構造周期、及び透過型電子顕微鏡写真から構造の状態を観察した結果を表１に記載した。この延伸後のサンプルでは、延伸前と比較し構造周期が増大しており、この延伸時に構造発展がなされたものと考えられる。さらに延伸後得られたフィルムから長さ×幅×厚み＝５０ｍｍ×１０ｍｍ×０．０３ｍｍ（２倍延伸）、５０ｍｍ×１０ｍｍ×０．０１ｍｍ（４倍延伸）サンプルを切り出し、チャック間距離２０ｍｍ、引張速度１０ｍｍ／分で測定した引張強度、引張伸びを測定した結果を表１に記載した。
【００６５】
なお、使用樹脂は、以下に示すものを使用した。
ＰＰＳ−１：ＰＰＳ樹脂（上述の参考例で重合したＰＰＳ樹脂）
ＰＥＴ−１：ポリエチレンテレフタレート樹脂（極限粘度０．６２（ｏ．ｃ．ｐ法、２５℃；［η］）
比較例１〜３
フルフライト形状のスクリューを有する（φ４０ｍｍ）単軸押出機を用いて、スクリュー回転数５０ｒｐｍで始めに溶融混練した以外は、実施例２〜４と同様に溶融混練し、ダイから吐出後すぐに氷水中に急冷し、構造を固定したガットを得たが、本ガットは濁っており、また該ガットから超薄切片を切り出したサンプルについて、透過型電子顕微鏡にて１０００倍に拡大して観察を行うと、２μｍ以上の不均一な分散構造物が観測された。このことから、本系は、上記押出機中の剪断下で相溶化していないことがわかる。本系についても、実施例２〜４と同様にフィルムを作製し機械特性を測定した結果を表１に記載した。またさらにこれらのフィルムから、１００ｍｍ角のサンプルを切り出し、４辺をクリップで固定し、９０℃６０秒間予熱後、９０℃で温調されたオーブン内で、延伸速度２０００％／分、延伸倍率２倍、および４倍で、４辺のクリップを同時２軸延伸となるよう延伸させた。延伸倍率２倍では延伸できるものの、延伸倍率４倍では、いずれもクリップ部で破断し、延伸することができなかった。
【００６６】
【表１】

【００６７】
本発明のスピノーダル分解により、特定構造周期の両相連続構造物、若しくは分散構造物を形成したＰＰＳフィルム、及びそれを延伸させたＰＰＳフィルムは、優れた強度および靱性を有することがわかる。
【００６８】
【発明の効果】
以上説明した様に、本発明のＰＰＳフィルムは、ＰＰＳ樹脂の使用量を低減しても、ＰＰＳ樹脂の有する強度等の機械特性などの特性を有しながら、靱性に優れるものであり、この特性を活かして各種ＰＰＳフィルム用途に有用に用いることができる。さらには本発明のＰＰＳフィルムは、規則性に優れる特性も有しており、これを活かして機能性ＰＰＳフィルムとしても有用に用いることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polyphenylene sulfide film having excellent heat resistance, mechanical properties, chemical resistance, and excellent toughness possessed by a polyphenylene sulfide resin, and capable of reducing the amount of polyphenylene sulfide resin used, and It relates to the manufacturing method.
[0002]
[Prior art]
Polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) has excellent properties as engineering plastics such as excellent heat resistance, flame retardancy, chemical resistance, dimensional stability, rigidity and electrical insulation. It is used for various electrical / electronic parts, machine parts, automobile parts, etc., mainly for molding. PPS resins have been put into practical use as heat-resistant films by taking advantage of the above-mentioned features such as excellent heat resistance and chemical resistance. However, PPS resins have complicated manufacturing processes for raw materials and are used in polymerization processes. The production process is complicated and expensive, such as the need for a polymerization solvent treatment process, and there are drawbacks that it is relatively brittle. Therefore, the film application is limited in its use, and has hindered the development of new applications. It was. Under such circumstances, there is a demand for a high toughness PPS film that reduces the amount of PPS resin used, does not lose the characteristics of the PPS resin, is economical, and has improved brittleness of the PPS resin. A method of blending other thermoplastic resins and forming a polymer alloy is considered promising.
[0003]
Patent Document 1 discloses a blend film in which a PPS resin and a polyester resin whose repeating unit is ethylene terephthalate are blended. This document aims to provide a PPS film having excellent economic efficiency, and is obtained by mixing a polyester resin having a repeating unit of ethylene terephthalate using a commonly used single-screw extruder. The technical idea of improving the toughness of the PPS is not disclosed, and the literature does not disclose the dispersion diameter in the PPS film described in the present invention.
[0004]
In Patent Document 2, fibers obtained by melt-spinning partially compatible polymer blends that are compatible with each other in a specific temperature range are subjected to spinodal decomposition or nucleation and growth by heat treatment, etc. A polymer blend fiber having a dispersed structure of 0.001 to 0.4 μm formed in the cross section is described. However, in the invention described in the same document, a polyester resin is mainly used, the use of PPS resin is not described, and there is no mention of use in a film.
[0005]
[Patent Document 1]
JP 7-88954 A (page 3-5)
[Patent Document 2]
JP-A-8-113829 (page 5-7)
[0006]
[Problems to be solved by the invention]
The present invention is a polyphenylene sulfide having excellent heat resistance, mechanical properties and chemical resistance possessed by a PPS resin, having excellent toughness and being able to reduce the amount of PPS resin used, and being excellent in economic efficiency. The object is to provide a film.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that in a polyphenylene sulfide film comprising a polyphenylene sulfide resin and a polyester resin having polyethylene terephthalate as a main structural unit, both of structural periods of 0.001 to 2 μm. The inventors have found that a polyphenylene sulfide film whose structure is controlled to a phase-continuous structure or a dispersed structure having a distance between particles of 0.001 to 2 μm has the above-mentioned properties, and has completed the present invention.
[0008]
  That is, the present invention
(1) A polyphenylene sulfide film comprising a polyphenylene sulfide resin and a polyester resin having polyethylene terephthalate as a main structural unit,Peaks are observed by measurement using small-angle X-ray scattering or light scattering,In the polyphenylene sulfide film, the polyphenylene sulfide resin and the polyester resin form a biphasic continuous structure having a structural period of 0.001 to 2 μm, or a dispersed structure with a distance between particles of 0.001 to 2 μm. Polyphenylene sulfide film,
(2) The two-phase continuous structure or dispersed structure in the polyphenylene sulfide film is formed by phase-separating a polyphenylene sulfide resin and a polyester resin mainly composed of polyethylene terephthalate by spinodal decomposition. 1) The polyphenylene sulfide film described in
(3) The polyphenylene sulfide film according to any one of (1) to (2) above, wherein the polyphenylene sulfide film is obtained through melt-kneading.
(4) The polyphenylene sulfide film described above (3), wherein the polyphenylene sulfide film is obtained by compatibilizing under shear during melt-kneading and then phase-separating under non-shear after discharge. Polyphenylene sulfide film,
(5) A stretched polyphenylene sulfide film characterized by obtaining a stretched polyphenylene sulfide film by stretching the polyphenylene sulfide film according to any one of the above (1) to (4) while being heat treated, and then further heat treating. ,
(6) A biphasic continuous structure in which the polyphenylene sulfide resin and the polyester resin mainly composed of polyethylene terephthalate in the stretched polyphenylene sulfide have a structural period of 0.001 to 2 μm.,Or a stretched polyphenylene sulfide film as described in (5) above, wherein a dispersed structure having a distance between particles of 0.001 to 2 μm is formed.
(7) A method for producing a polyphenylene sulfide film comprising a polyphenylene sulfide resin composition comprising a polyphenylene sulfide resin and a polyester resin comprising polyethylene terephthalate as a main constituent unit, wherein the polyphenylene sulfide resin and the polyester resin are subjected to spinodal decomposition. A process for producing a polyphenylene sulfide film, characterized in that a two-phase continuous structure having a structural period of 0.001 to 2 μm or a dispersed structure having a distance between particles of 0.001 to 2 μm is formed.
(8) The method for producing a polyphenylene sulfide film according to (7) above, wherein spinodal decomposition is induced by melt-kneading the polyphenylene sulfide resin composition,
(9) The polyphenylene sulfide described in (8) above, wherein the polyphenylene sulfide resin and the polyester resin mainly composed of polyethylene terephthalate are compatibilized under shear during melt-kneading and then phase-separated under non-shear after discharge. A method for producing a sulfide film,
(10) The polyphenylene sulfide according to (9), wherein the polyphenylene sulfide film phase-separated until a desired structural period or interparticle distance is obtained under non-shearing after the discharge is rapidly cooled to fix the structure. (11) After producing a polyphenylene sulfide film by the method for producing a polyphenylene sulfide film described in any one of (7) to (10) above, and then stretching the polyphenylene sulfide film while performing a heat treatment And a method for producing a stretched polyphenylene sulfide film, which is further heat-treated.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
[0010]
The PPS resin used in the present invention is a polymer containing a repeating unit represented by the following structural formula,
[0011]
[Chemical 1]

[0012]
From the viewpoint of heat resistance, a polymer containing 70 mol% or more, particularly 90 mol% or more of the repeating unit represented by the above structural formula is preferable. In addition, the PPS resin can comprise 30 mol% or less of the repeating units with repeating units having the following structural formula.
[0013]
[Chemical 2]

[0014]
The PPS resin used in the present invention is, for example, a generally known method, that is, a method for obtaining a polymer having a relatively small molecular weight described in JP-B-45-3368, or JP-B-52-12240 and JP-A-61-61. It can be produced by a method described in Japanese Patent No. 7332 for obtaining a polymer having a relatively large molecular weight. In the present invention, the PPS resin obtained as described above is crosslinked / polymerized by heating in air, heat treatment under an inert gas atmosphere such as nitrogen or under reduced pressure, washing with an organic solvent, hot water, aqueous acid solution, etc. It can also be used after being subjected to various treatments such as activation with functional group-containing compounds such as acid anhydrides, amines, isocyanates, functional group-containing disulfide compounds, and more than two types of these treatments. Of course it is possible. Of course, it is also possible to use two or more types of PPS resins subjected to these treatments. As a specific method for using two or more types of PPS resins, a PPS resin crosslinked by heating in air is used. And PPS resin that has not been heat-treated, PPS resin that has been washed with an aqueous acid solution and PPS resin that has been washed with an organic solvent, PPS resin that has been washed with an organic solvent, and PPS that has not been washed with an organic solvent Examples include mixing of resins.
[0015]
The molecular weight of the PPS resin used in the present invention is not particularly limited, but is related to the conditions for spinodal decomposition described later, and therefore needs to be selected as appropriate. 5 to 1,000 Pa · s (320 ° C., shear rate 1000 sec^-1) Are used, and those having 10 to 500 Pa · s are preferably used.
[0016]
As a specific method for crosslinking / high molecular weight by heating PPS resin, it can be performed in an oxidizing gas atmosphere such as air or oxygen, or in a mixed gas atmosphere of the oxidizing gas and an inert gas such as nitrogen or argon. Examples of the method include heating until a desired melt viscosity is obtained at a predetermined temperature. The heat treatment temperature is usually selected from 170 to 280 ° C., preferably from 200 to 270 ° C., and the time is usually selected from 0.5 to 100 hours, preferably from 2 to 50 hours. The target viscosity level can be obtained by appropriately controlling the time. The heat treatment apparatus may be a normal hot air dryer with reduced pressure specifications or a high-sealing specification, or a rotary type or a heating apparatus with a stirring blade, but it is a rotary type for efficient and more uniform treatment. Alternatively, it is more preferable to use a heating device with a stirring blade.
[0017]
As a specific method for heat-treating the PPS resin under an inert gas atmosphere such as nitrogen or under reduced pressure, a heat treatment temperature of 150 to 280 ° C., preferably 200 to 200 ° C. under an inert gas atmosphere such as nitrogen or under reduced pressure. A method of heat treatment at 270 ° C. and a heating time of 0.5 to 100 hours, preferably 2 to 50 hours can be exemplified. The heat treatment apparatus may be a stationary type heating apparatus, or a rotary type or a heating apparatus with a stirring blade, but a heating apparatus with a rotary type or a stirring blade is used for efficient and more uniform treatment. Is more preferable.
[0018]
The following method can be illustrated as a specific method when the PPS resin is washed with an organic solvent. That is, the organic solvent used for washing is not particularly limited as long as it does not have an action of decomposing the PPS resin. For example, nitrogen-containing polar solvents such as N-methylpyrrolidone, dimethylformamide, and dimethylacetamide, dimethyl sulfoxide , Sulfoxide / sulfone solvents such as dimethylsulfone, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, ether solvents such as dimethyl ether, dipropyl ether, tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene chloride, dichloroethane , Halogen solvents such as tetrachloroethane, chlorobenzene, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol Lumpur, phenol, cresol, alcohol phenol based solvents such as polyethylene glycol, benzene, toluene, and aromatic hydrocarbon solvents such as xylene. Among these organic solvents, use of N-methylpyrrolidone, acetone, dimethylformamide, chloroform or the like is preferable. Moreover, these organic solvents can also be used by 1 type or in mixture of 2 or more types. As a method of washing with an organic solvent, there is a method of immersing a PPS resin in an organic solvent, and if necessary, stirring or heating can be appropriately performed. There is no restriction | limiting in particular about the washing | cleaning temperature at the time of wash | cleaning PPS resin with an organic solvent, Arbitrary temperature of about normal temperature-about 300 degreeC can be selected. Although the cleaning efficiency tends to increase as the cleaning temperature increases, a sufficient effect is usually obtained at a cleaning temperature of room temperature to 150 ° C.
[0019]
The PPS resin that has been washed with an organic solvent is preferably washed several times with water or warm water in order to remove the remaining organic solvent.
[0020]
The following method can be illustrated as a specific method when the PPS resin is treated with hot water. That is, in order to express a preferable chemical modification effect of the PPS resin by hot water washing, the water used is preferably distilled water or deionized water. The operation of the hot water treatment is usually performed by putting a predetermined amount of PPS resin into a predetermined amount of water and heating and stirring at normal pressure or in a pressure vessel. The ratio of the PPS resin to water is preferably larger, but usually a bath ratio of 200 g or less of PPS resin is selected for 1 liter of water.
[0021]
The following method can be illustrated as a specific method in the case of acid-treating PPS resin.
[0022]
That is, there is a method of immersing a PPS resin in an acid or an aqueous solution of an acid, and stirring or heating can be performed as necessary. The acid used is not particularly limited as long as it does not have an action of decomposing PPS resin, and is saturated with aliphatic monocarboxylic acid such as formic acid, acetic acid, propionic acid and butyric acid, and halo-substituted aliphatic such as chloroacetic acid and dichloroacetic acid. Aliphatic unsaturated monocarboxylic acids such as saturated carboxylic acid, acrylic acid and crotonic acid, aromatic carboxylic acids such as benzoic acid and salicylic acid, dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, phthalic acid and fumaric acid, sulfuric acid Inorganic acid compounds such as phosphoric acid, hydrochloric acid, carbonic acid and silicic acid. Of these, acetic acid and hydrochloric acid are more preferably used. The acid-treated PPS resin is preferably washed several times with water or warm water in order to remove residual acid or salt. The water used for washing is preferably distilled water or deionized water in the sense that the effect of the preferred chemical modification of the PPS resin by acid treatment is not impaired.
[0023]
The polyester resin having polyethylene terephthalate as the main structural unit used in the present invention (hereinafter sometimes abbreviated as PET resin) is most preferably a homopolymer of polyethylene terephthalate resin. However, a part of the terephthalic acid component is isophthalic acid, 5-sodium. It may be substituted with one or more of sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenoxyethanedicarboxylic acid, adipic acid, sebacic acid, azelaic acid, dodecanedicarboxylic acid, etc., or a part of ethylene glycol 1,4-butanediol, propylene glycol, neopentyl glycol, hexamethylene glycol, pentamethylene glycol, 1,4-cyclohexanedimethanol, glycerin, pentaerythritol, polyethylene glycol Those substituted with one or more of polytetramethylene glycol may be. In this case, the copolymerization rate is desirably in the range of 15 mol% or less, and more desirably in the range of 5 mol% or less.
[0024]
The molecular weight of the PET resin used in the present invention is not particularly limited, but it is necessary to select it appropriately because it relates to the conditions for spinodal decomposition described later, and the intrinsic viscosity that is a parameter related to this molecular weight is usually Is 0.6 or more (25 ° C., orthochlorophenol solution), among which 0.7 or more is preferably used. The upper limit is preferably 1.5 or less.
[0025]
The polyphenylene sulfide film of the present invention comprises a polyester resin having PPS resin and polyethylene terephthalate as main structural units, and the polyphenylene sulfide film has a structural period of 0.001 μm between the polyphenylene sulfide resin and the polyester resin. It is necessary to form a two-phase continuous structure of ˜2 μm or a dispersed structure having a distance between particles of 0.001 μm to 2 μm. As a method for obtaining a polyphenylene sulfide film having such a structure, a method using spinodal decomposition described later is preferable, and a method using shear field-dependent phase dissolution / phase decomposition described later facilitates further fine structure control. Therefore, it is more preferably used.
[0026]
Hereinafter, a structure control method in a polymer alloy generally composed of a two-component resin will be described. Polymer alloys composed of two-component resins are compatible with these compositions in a compatible system that is compatible in all practical areas above the glass transition temperature and below the thermal decomposition temperature, and vice versa. There are incompatible systems and partial compatible systems that are compatible in one region and phase-separated in another region. Furthermore, this partial compatible system is phase-separated by spinodal decomposition depending on the conditions of the phase-separated state. Some are phase separated by nucleation and growth.
[0027]
Phase separation by spinodal decomposition refers to phase separation that occurs in an unstable state inside the spinodal curve in phase diagrams for different two-component resin compositions and temperatures, and phase separation by nucleation and growth refers to the phase separation. In the figure, it refers to phase separation that occurs in the metastable state inside the binodal curve and outside the spinodal curve.
[0028]
The spinodal curve refers to the difference (ΔGmix) between the free energy in the case of being compatible and the sum of the free energy in the incompatible phase (ΔGmix) when two different resin components are mixed with respect to the composition and temperature. φ) partial differential twice (∂²ΔGmix / ∂φ²) Is zero, and inside the spinodal curve,²ΔGmix / ∂φ²<Unstable state of 0²ΔGmix / ∂φ²> 0.
[0029]
The binodal curve is a boundary curve between the region where the system is compatible and the region where the system is separated with respect to the composition and temperature.
[0030]
Here, the case of being compatible in the present invention is a state in which they are uniformly mixed at the molecular level. Specifically, both phases having different two-component resins as main components are 0.001 μm or more. The case where the phase structure is not formed is indicated, and the case where the phase is incompatible is the case where the phase is not in a compatible state, that is, the phases mainly composed of two different resin components are 0.001 μm or more. It refers to the state of forming a phase structure. Whether or not they are compatible is determined by, for example, an electron microscope, a differential scanning calorimeter (DSC), or other various methods as described in Polymer Alloys and Blends, Leszek A Utracki, hanser Publishers, Munich Viema New York, P64. Can be judged by.
[0031]
According to detailed theory, in spinodal decomposition, if the temperature of a mixed system that has been uniformly mixed at the temperature of the compatible region is rapidly changed to the temperature of the unstable region, the system will rapidly move toward the coexisting composition. Initiate phase separation. At that time, the concentration is monochromatized at a constant wavelength, and a two-phase continuous structure is formed in which both separated phases are continuously intertwined regularly with a structure period (Λm). After the formation of the two-phase continuous structure, the process in which only the concentration difference between the two phases increases while keeping the structure period constant is called the initial process of spinodal decomposition.
[0032]
Further, the structural period (Λm) in the initial process of the above-mentioned spinodal decomposition has a thermodynamic relationship as shown in the following equation.
Λm ~ [│Ts-T│ / Ts]^-1/2
(Where Ts is the temperature on the spinodal curve)
Here, the two-phase continuous structure referred to in the present invention refers to a structure in which both components of the resin to be mixed each form a continuous phase and are entangled three-dimensionally. A schematic diagram of this two-phase continuous structure is described, for example, in “Polymer Alloy Fundamentals and Applications (Second Edition) (Chapter 10.1)” (edited by the Society of Polymer Science: Tokyo Kagaku Dojin).
[0033]
In spinodal decomposition, after going through such an initial process, it goes through a medium-term process in which an increase in wavelength and an increase in concentration difference occur simultaneously, and a later process in which an increase in wavelength occurs in a self-similar manner after the concentration difference reaches the coexisting composition. Finally, the process proceeds until separation into two macroscopic phases.
[0034]
Here, the dispersion structure referred to in the present invention is a so-called sea-island structure in which particles mainly composed of the other resin component are interspersed in a matrix mainly composed of one resin component. Point.
[0035]
On the other hand, in the above-described nucleation and growth, which is phase separation in the metastable region, an irregular dispersion structure, which is a sea-island structure, is formed from the initial stage. It is difficult to obtain.
[0036]
In order to confirm whether these two-phase continuous structure or dispersed structure is formed by spinodal decomposition, it is effective to confirm whether it has a regular periodic structure. For example, in addition to confirming that a two-phase continuous structure is formed by observation with an optical microscope or a transmission electron microscope, the scattering maximum in a scattering measurement performed using a light scattering device or a small-angle X-ray scattering device Confirmation of appearing is necessary. Note that the light scattering device and the small-angle X-ray scattering device have different optimum measurement regions, so that they are appropriately selected according to the size of the structure period. The existence of the scattering maximum in this scattering measurement is a proof that there is a regular phase separation structure with a certain period, and its period Λm corresponds to the structure period in the case of the biphasic continuous structure, and the interparticle distance in the case of the dispersion structure. Correspond. The value is calculated using the following equation using the wavelength λ of the scattered light within the scatterer and the scattering angle θm that gives the scattering maximum.
Λm = (λ / 2) / sin (θm / 2)
Can be calculated.
[0037]
Here, in order to realize spinodal decomposition in a polymer alloy composed of a PPS resin and a PET resin, the PPS resin and the PET resin are made in a compatible state, and then set to an unstable state inside the spinodal curve.
[0038]
First, as a method of realizing a compatible state between the PPS resin and the PET resin, after dissolving in a common solvent, the solution is obtained by spray drying, freeze drying, coagulation in a non-solvent substance, film formation by solvent evaporation, or the like. The solvent casting method and the PPS resin and the PET resin having a small difference in solubility parameter are compatible by melt kneading by selecting the molecular weight, and therefore, a melt kneading method using the method is used. Among these, compatibilization by melt kneading, which is a dry process that does not use a solvent, is preferably used in practice.
[0039]
In addition, when melt-kneading a PPS resin and a PET resin, if any of the resins used has a molecular weight that is usually used for molding applications such as fibers and three-dimensional molded products, It can be compatibilized by carrying out, and it can be compatibilized under lower shear by lowering the molecular weight of one or both.
[0040]
In order to achieve compatibilization by melt-kneading, a normal single-screw extruder or a twin-screw extruder can be used as long as the compatibilization conditions are satisfied. Among them, a twin-screw extruder is preferably used. The temperature for compatibilization varies depending on the combination of the molecular weights of the PPS resin and the PET resin, and cannot be generally specified, but the PPS resin and / or the PET resin is appropriately used so that the compatibility is achieved at the temperature at the time of melt kneading. Based on the phase diagram when the molecular weight is reduced, it can be set by performing a simple preliminary experiment.
[0041]
Therefore, when the polymer alloy composed of the PPS resin and the PET resin, which are made compatible by melt-kneading, is decomposed into the unstable state inside the spinodal curve, and the spinodal decomposition is performed, the temperature and other conditions are as follows. Although it differs depending on the combination of the molecular weights of the PPS resin and the PET resin and cannot be generally stated, it can be set by performing a simple preliminary experiment based on the above phase diagram. As the low molecular weight PPS, those having a melt viscosity of 0.01 to less than 5 Pa · s are preferably used, and as the low molecular weight PET, those having an intrinsic viscosity of less than 0.6 are preferably used, and the PPS used as the lower limit is used. Although it varies depending on the molecular weight of the resin, it may be in a range that can be used as a film as a result of blending.
[0042]
After phase separation by this spinodal decomposition, the structure may be fixed when the desired structural period is reached. As a method of immobilizing the structure product by such spinodal decomposition, structural fixation of one or both components of the phase-separated phase in a short time by rapid cooling or the like, which makes it impossible to move freely by crystallization, Is mentioned. In addition, in the process of increasing the wavelength from the mid-stage process to the late-stage process, depending on the influence of the composition and the interfacial tension, the continuity of one phase may be interrupted and the above-described biphasic continuous structure may be changed to a dispersed structure. In this case, the structure may be fixed when the desired interparticle distance is reached.
[0043]
Here, as a method for producing a PPS film using spinodal decomposition in a partially compatible system, the PPS resin and the PET resin are once dissolved at the temperature at the time of melt kneading using a single-screw or twin-screw extruder during film formation. The discharged polymer alloy is discharged from the T-die, and is cooled at an ambient temperature in the range of 10 to 30 ° C. after discharge. The spinodal is decomposed and then solidified by cooling with a cast drum to fix the structure of the spinodal decomposition. The desired structure is obtained by spinodal decomposition using a method for forming into a film, a polishing method for forming between two rolls temperature-controlled under a temperature condition for spinodal decomposition of a polymer alloy in a compatible state after discharge, or a calendering method. There is a method of obtaining a film having a period or an interparticle distance, etc. Not. In addition, when casting the cast drum, in order to bring the molten resin into close contact with the cast drum, a method of applying an electrostatic force, a method using an air knife, a method using a pressing drum facing the cast drum, or the like can be used. Moreover, when casting to a cast drum, it is preferable to install the cast drum directly under a discharge outlet and to cool rapidly. Furthermore, it is more preferable to use pellets that have been previously compatibilized using a twin-screw extruder and frozen in their structure before being supplied to the extruder for film formation. In such a PPS film, it is usually preferable that the PPS resin and the PET resin have a two-phase continuous structure with a structural period of 0.001 to 2 μm, or a dispersed structure with an interparticle distance of 0.001 to 2 μm. It is more preferable that a double phase continuous structure of ˜1.2 μm or a dispersed structure having a distance between particles of 0.001 to 1.2 μm is obtained because excellent mechanical properties can be obtained, and further, a structural period of 0.001 to 0.003. More preferably, it is a continuous structure having a biphasic structure of 8 μm or a dispersed structure having a distance between particles of 0.001 to 0.8 μm.
[0044]
The obtained film can be stretched, and the stretching method is not particularly limited, and may be sequential biaxial stretching or simultaneous biaxial stretching, and the stretching ratio is usually between 2 and 8 times. A speed of between 500 and 5000% / min is often used. Furthermore, the heat treatment temperature at the time of stretching is usually preferably a method of heat treatment at a temperature higher than the glass transition temperature of the PPS resin. However, when the PPS resin and the PET resin have a single glass transition temperature in a compatibilized state, phase decomposition may occur. When the glass transition temperature in the polymer alloy in the state of progress is between the glass transition temperatures of the PPS resin and the PET resin, heat treatment is performed at the lowest temperature or higher among the glass transition temperatures in the polymer alloy. Is more preferable. Moreover, it is preferable to make this heat processing temperature below the temperature rising crystallization temperature of crystalline resin from a viewpoint of making it difficult to receive the inhibition of extending | stretching by crystallization of crystalline resin. The stretched film is preferably used by further heat treatment to stabilize the structure. The heat treatment temperature for stabilization is usually preferably a method of heat treatment at a temperature equal to or higher than the glass transition temperature of the PPS resin. However, the glass transition temperature in the polymer alloy is in the state where the phase separation is proceeding. And the glass transition temperature of the PET resin, it is more preferable to perform heat treatment at the lowest temperature or higher among the glass transition temperatures in the polymer alloy. Further, the structural period and the interparticle distance of the stretched polymer alloy film increase due to stretching. In such a stretched PPS film, it is necessary that the PPS resin and the PET resin have a two-phase continuous structure with a structural period of 0.001 to 2 μm, or a dispersed structure with an interparticle distance of 0.001 to 2 μm. It is preferable to obtain a double-phase continuous structure of 0.001 to 1.2 μm or a dispersed structure having a distance between particles of 0.001 to 1.2 μm because excellent mechanical properties can be obtained, and further, a structural period of 0.001 to 0 More preferably, it is a continuous structure having a double phase of 8 μm or a dispersed structure having a distance between particles of 0.001 to 0.8 μm.
[0045]
In addition to spinodal decomposition by this partially compatible system, spinodal decomposition is also induced by melt kneading in non-compatible systems, for example, once compatible under shearing during melt kneading, etc., and then in an unstable state again under non-shearing. Phase separation by spinodal decomposition is also possible by so-called shear field-dependent phase dissolution / phase decomposition in which phase decomposition occurs. Has a phase continuous structure. Furthermore, this shear field-dependent phase dissolution / phase decomposition is the same as the method based on the temperature change of the partially miscible system in which the spinodal curve does not change because the spinodal curve changes due to the shear field and the unstable region expands. Even in the temperature change range, the substantial degree of supercooling (| Ts−T |) increases, and as a result, it becomes easy to reduce the structural period in the initial process of spinodal decomposition in the above relational expression, and the structure is refined. Is more preferable because it becomes easier.
[0046]
As a combination of the above-mentioned shear field-dependent phase dissolving / phase-decomposing resin, it is a combination that is compatible under shearing and spinodal decomposition under non-shearing. A polymer alloy consisting of
[0047]
In order to achieve compatibilization by melt-kneading under shear, an ordinary single-screw extruder or twin-screw extruder can be used as long as it has performance capable of satisfying the compatibilizing conditions. It is preferable to use a twin screw extruder having a screw arrangement so that it can be used. Here, the compatibilizing temperature, the temperature for spinodal decomposition, and other conditions vary depending on the combination of the molecular weights of the PPS resin and the PET resin, and cannot be generally specified, but are based on phase diagrams under various shear conditions. You can set conditions by doing a simple preliminary experiment
Next, the polymer alloy composed of the PPS resin and the PET resin made into a compatible state by melt-kneading under shear is set to an unstable state when the spinodal decomposition is performed as an unstable state inside the spinodal curve under non-shear. The temperature and other conditions vary depending on the combination of the molecular weights of the PPS resin and the PET resin, and cannot be generally specified, but are set by performing simple preliminary experiments based on phase diagrams under various shear conditions. can do. In order to more effectively produce a fine structure by spinodal decomposition in this shear field-dependent phase dissolution / phase decomposition, PPS resin, It is preferable to select a combination of the molecular weights of PET and PET resin.
[0048]
After phase separation by this spinodal decomposition, the structure may be fixed when the desired structural period is reached. As a method of immobilizing the structure product by such spinodal decomposition, structural fixation of one or both components of the phase-separated phase in a short time by rapid cooling or the like, which makes it impossible to move freely by crystallization, Is mentioned. In addition, in the process of increasing the wavelength from the mid-stage process to the late-stage process, depending on the influence of the composition and the interfacial tension, the continuity of one phase may be interrupted and the above-described biphasic continuous structure may be changed to a dispersed structure. In this case, the structure may be fixed when the desired interparticle distance is reached.
[0049]
Here, as a method of producing a PPS film using spinodal decomposition in shear field-dependent phase dissolution / phase decomposition, it is necessary to first compatibilize the PPS resin and the PET resin under shear during melt kneading. As long as it has performance capable of satisfying the conditions for solubilization, a normal single-screw extruder or a twin-screw extruder is used. Among them, it is preferable to use a twin-screw extruder having a screw arrangement capable of imparting high shear. . Further, as a method for surely realizing the compatibilization in the plasticizing step of the film forming apparatus, the mixture is melt-kneaded and compatibilized while applying sufficient shear to be compatibilized with a twin-screw extruder in advance, and after discharging, the ice water A preferred example is a method of forming a film using a material having a structure fixed in a compatibilized state by quenching. Next, the polymer alloy once compatibilized under shearing is subjected to spinodal decomposition under non-shearing after discharging from the T die, and cooled and solidified with a cast drum to fix the spinodal decomposition structure and form a film, There are a polishing method in which molding is performed between two rolls that are temperature-controlled under a temperature condition for spinodal decomposition, and a method for obtaining a film having a desired structural period or interparticle distance by spinodal decomposition by a calendering method. However, it is not particularly limited. In addition, when casting the cast drum, in order to bring the molten resin into close contact with the cast drum, a method of applying an electrostatic force, a method using an air knife, a method using a pressing drum facing the cast drum, or the like can be used. Moreover, when casting to a cast drum, it is preferable to install the cast drum directly under a discharge outlet and to cool rapidly. In such a PPS film, it is necessary that the PPS resin and the PET resin have a two-phase continuous structure with a structural period of 0.001 to 2 μm, or a dispersed structure with an interparticle distance of 0.001 to 2 μm. It is preferable to obtain a double-phase continuous structure of 001 to 1.2 μm or a dispersed structure having a distance between particles of 0.001 to 1.2 μm because excellent mechanical properties can be obtained, and further, a structural period of 0.001 to 0.003. It is more preferable to use a double-phase continuous structure of 8 μm or a dispersed structure having a distance between particles of 0.001 to 0.8 μm.
[0050]
The obtained film can be stretched, and the stretching method is not particularly limited, and may be sequential biaxial stretching or simultaneous biaxial stretching, and the stretching ratio is usually between 2 and 8 times. A speed of between 500 and 5000% / min is often used. Furthermore, the heat treatment temperature at the time of stretching is usually preferably a method of heat treatment at a temperature higher than the glass transition temperature of the PPS resin. However, when the PPS resin and the PET resin have a single glass transition temperature in a compatibilized state, phase decomposition may occur. When the glass transition temperature in the polymer alloy in the state of progress is between the glass transition temperatures of the PPS resin and the PET resin, heat treatment is performed at the lowest temperature or higher among the glass transition temperatures in the polymer alloy. Is more preferable. Moreover, it is preferable to make this heat processing temperature below the temperature rising crystallization temperature of crystalline resin from a viewpoint of making it difficult to receive the inhibition of extending | stretching by crystallization of crystalline resin. The stretched film is preferably used by further heat treatment to stabilize the structure. The heat treatment temperature for stabilization is usually preferably a method of heat treatment at a temperature equal to or higher than the glass transition temperature of the PPS resin. However, the glass transition temperature in the polymer alloy is in the state where the phase separation is proceeding. And the glass transition temperature of the PET resin, it is more preferable to perform heat treatment at the lowest temperature or higher among the glass transition temperatures in the polymer alloy. Further, the structural period and the interparticle distance of the stretched polymer alloy film increase due to stretching. In such a stretched PPS film, it is necessary that the PPS resin and the PET resin have a two-phase continuous structure with a structural period of 0.001 to 2 μm, or a dispersed structure with an interparticle distance of 0.001 to 2 μm. It is preferable to obtain a double-phase continuous structure of 0.001 to 1.2 μm or a dispersed structure having a distance between particles of 0.001 to 1.2 μm because excellent mechanical properties can be obtained, and further, a structural period of 0.001 to 0 More preferably, it is a continuous structure having a double phase of 8 μm or a dispersed structure having a distance between particles of 0.001 to 0.8 μm.
[0051]
In addition, adding a third component which is a copolymer such as a block copolymer, a graft copolymer or a random copolymer containing a component constituting the polymer alloy to the polymer alloy comprising the two component resins constituting the present invention is a phase decomposition. It is preferably used in order to reduce the free energy at the interface between the two phases and to facilitate the control of the structural period in the two-phase continuous structure and the distance between the dispersed particles in the dispersed structure. In this case, the third component such as the copolymer is usually distributed to each phase of the polymer alloy composed of the two-component resin except the copolymer, and thus can be handled in the same manner as the polymer alloy composed of the two-component resin.
[0052]
Although there is no restriction | limiting in particular about the composition of the resin component which comprises the PPS film in this invention, Usually, the range of 95 weight% / 5 weight%-5 weight% / 95 weight% is preferably used for PPS resin / PET resin. Further, the range of 90% / 10% -10% / 90% by weight is more preferable, and if the range is 75% / 25% -25% / 75% by weight, the two-phase continuous structure is Since it is relatively easy to obtain, it is preferably used.
[0053]
The PPS film of the present invention may further contain other various additives as long as the object of the present invention is not impaired. As these other additives, for example, inorganic particles and / or crosslinked organic particles as a lubricant, antioxidants (phosphorous-based, sulfur-based, etc.), ultraviolet absorbers, heat stabilizers (hindered phenol-based), Examples include release agents, antistatic agents, antiblocking agents, colorants including dyes and pigments, and antibacterial agents.
[0054]
These additives can be blended at any stage for producing the PPS film of the present invention, but a master batch is prepared by adding these additives to any of the resins constituting the polymer alloy in advance. In general, a method of adding it is preferably used.
[0055]
The thickness of the PPS film in the present invention is not particularly limited, but is usually preferably 190 μm or less, and particularly preferably 100 μm or less. Moreover, there is no restriction | limiting in particular as a minimum, However, It is preferable that it is 10 micrometers or more.
[0056]
The PPS film in the present invention can be suitably used for various film applications as a polyphenylene sulfide film having excellent heat resistance, mechanical properties and chemical resistance possessed by polyphenylene sulfide resin and having excellent toughness.
[0057]
【Example】
Hereinafter, an example is given and the effect of the present invention is further explained.
[0058]
Reference example (polymerization of PPS resin)
(PPS-1)
A sodium sulfide nonahydrate 6.004 kg (25 mol) and N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) 4.5 kg are charged into an autoclave equipped with a stirrer, and the temperature is gradually raised to 205 ° C. while passing through nitrogen. Distilled 3.6 liters. Next, after cooling the reaction vessel to 180 ° C., 3.719 kg (25.3 mol) of 1,4-dichlorobenzene and 3 kg of NMP were added, sealed under nitrogen, heated to 270 ° C., heated to 270 ° C. and 1. Reacted for 5 hours. After cooling, the reaction product is washed twice with warm water, and then this slurry is placed in an autoclave equipped with a stirrer together with 3 kg of ion-exchanged water and heated to 190 ° C. After reaching 190 ° C., cooled to room temperature, filtered, and further filtered. Washed several times with hot water. This was filtered and then dried under reduced pressure at 80 ° C. for 24 hours to obtain 2.48 kg of PPS resin. This PPS resin is linear and has a melt viscosity of 80 Pa · s (320 ° C., shear rate of 1000 sec.^-1), Glass transition temperature 89 ° C., crystal melting temperature 280 ° C.
[0059]
The melt viscosity is measured with a capillary type melt viscosity measuring apparatus (CAPIROGRAPH-1C manufactured by Toyo Seiki Co., Ltd.) with an orifice L / D = 20 (inner diameter 1 mm), and the glass transition temperature and the crystal melting temperature are determined by DSC (PERKIN-ELMER). Using DSC-7), the temperature was increased at a rate of 20 ° C./min.
[0060]
Examples 1-5
A raw material having the composition shown in Table 1 was set at an extrusion temperature of 320 ° C., had two kneading zones, and was rotated at a high speed of 300 rpm. 30), and the gut discharged from the die was immediately quenched into ice water to fix the structure. All of these guts were transparent, and the samples obtained by cutting out ultrathin sections from the guts were observed with a transmission electron microscope at a magnification of 100,000 times. It was confirmed that the structure was compatibilized without being seen. This shows that this system is compatibilized under shear in an extruder having an extrusion temperature of 320 ° C.
[0061]
In addition, this system is a system having an LCST type phase diagram, and the compatible region is expanded under shearing of an extruder.
[0062]
Furthermore, after discharging from the die, the gut in a state of being rapidly cooled in ice water to fix the structure and compatibilized was supplied to the strand cutter to produce pellets. Next, using this pellet, it was supplied to a single-screw extruder (φ30 mm) having a T-die at the tip portion set again at an extrusion temperature of 320 ° C. to form a film. In addition, in the film production, the resin discharged from the die of the T die is cast on a mirror cast drum of hard chrome whose temperature is adjusted to 20 ° C. directly under the T die (3 cm), and an electrostatic application of 8 kV is applied to the cast drum. The structure was fixed by rapid cooling by bringing it into close contact. Furthermore, after passing between rolls set to 5 m / min so that the winding speed becomes constant, a film was obtained by winding with a winding roll. The thickness of the obtained film was 0.1 mm. Moreover, although the obtained film was transparent, when the sample which cut out the ultra-thin section from this film was magnified by 100,000 times with the transmission electron microscope, all the samples were continuous in both phases. It was confirmed that a structure or a dispersed structure was present. Furthermore, when another sample was cut out from the obtained film and measured using small-angle X-ray scattering or light scattering, a peak was observed in all samples. Table 1 shows the structural period (Λm) calculated from the peak position (θm) by the following equation. In addition, the interparticle distance in the case of having a dispersed structure is also calculated by the same method as the structural period in the two-phase continuous structure.
Λm = (λ / 2) / sin (θm / 2)
From the above, at the time of film formation, the compatibilized state is maintained even under shearing in a single screw extruder, phase separation is performed by spinodal decomposition under non-shearing after discharging from the T die, and then rapidly cooled It is thought that the structure was fixed.
[0063]
Next, a sample of length × width × thickness = 50 mm × 10 mm × 0.1 mm was cut out from the film, and the measurement results of tensile strength and tensile elongation measured at a chuck distance of 20 mm and a tensile speed of 10 mm / min are shown in Table 1. Described.
[0064]
Next, a 100 mm square sample was cut out from the film obtained above, the four sides were fixed with a clip, preheated at 90 ° C. for 60 seconds, and then stretched at a rate of 2000% / min and a draw ratio in an oven temperature-controlled at 90 ° C. Four-sided clips were stretched simultaneously and biaxially at 2x and 4x. Furthermore, about this stretched film, heat treatment was performed by fixing four sides to an aluminum frame and passing it through an oven adjusted to 180 ° C. for 15 seconds to stabilize the structure of the stretched film. For the sample after stretching, the results of observing the structural period from small-angle X-ray scattering or light scattering and the state of the structure from a transmission electron micrograph are shown in Table 1, as described above. In the sample after the stretching, the structural period is increased as compared with that before the stretching, and it is considered that the structure has been developed at the time of the stretching. Furthermore, samples of length × width × thickness = 50 mm × 10 mm × 0.03 mm (2 times stretching), 50 mm × 10 mm × 0.01 mm (4 times stretching) were cut out from the film obtained after stretching, the distance between chucks was 20 mm, and the tension was Table 1 shows the results of measuring the tensile strength and tensile elongation measured at a speed of 10 mm / min.
[0065]
The following resins were used.
PPS-1: PPS resin (PPS resin polymerized in the above reference example)
PET-1: Polyethylene terephthalate resin (Intrinsic viscosity 0.62 (ocp method, 25 ° C .; [η])
Comparative Examples 1-3
Using a single screw extruder having a full flight-shaped screw (φ40 mm), melt and kneaded in the same manner as in Examples 2 to 4 except that the melt was first kneaded at a screw rotation speed of 50 rpm. The gut with a fixed structure was obtained by rapid cooling inside, but the gut was cloudy, and a sample obtained by cutting an ultrathin section from the gut was observed with a transmission electron microscope at a magnification of 1000 times In addition, a non-uniform dispersion structure of 2 μm or more was observed. This shows that this system is not compatibilized under shear in the extruder. For this system, the results of producing films and measuring mechanical properties in the same manner as in Examples 2 to 4 are shown in Table 1. Further, a 100 mm square sample was cut out from these films, the four sides were fixed with clips, preheated at 90 ° C. for 60 seconds, and then in an oven controlled at 90 ° C., a stretching speed of 2000% / min, a stretching ratio of 2 The four-sided clip was stretched so as to be simultaneously biaxially stretched at double and quadruples. Although the film could be stretched at a stretch ratio of 2 times, it could not be stretched at all at the stretch ratio of 4 because it was broken at the clip portion.
[0066]
[Table 1]

[0067]
It can be seen that the PPS film formed with a biphasic continuous structure having a specific structure period or a dispersed structure and the PPS film obtained by stretching the PPS film by the spinodal decomposition of the present invention have excellent strength and toughness.
[0068]
【The invention's effect】
As described above, the PPS film of the present invention is excellent in toughness while having properties such as strength and the like that the PPS resin has, even if the amount of PPS resin used is reduced. It can be usefully used for various PPS film applications. Furthermore, the PPS film of the present invention also has characteristics that are excellent in regularity, and can be used effectively as a functional PPS film by utilizing this.

Claims (11)

It is a polyphenylene sulfide film comprising a polyphenylene sulfide resin and a polyester resin mainly composed of polyethylene terephthalate, and a peak is observed by measurement using small-angle X-ray scattering or light scattering. In the polyphenylene sulfide film, A polyphenylene sulfide film, wherein the polyphenylene sulfide resin and the polyester resin form a two-phase continuous structure having a structural period of 0.001 to 2 μm, or a dispersed structure with a distance between particles of 0.001 to 2 μm. The biphasic continuous structure or dispersed structure in the polyphenylene sulfide film is formed by phase-separating a polyphenylene sulfide resin and a polyester resin mainly composed of polyethylene terephthalate by spinodal decomposition. Polyphenylene sulfide film. The polyphenylene sulfide film according to claim 1, wherein the polyphenylene sulfide film is obtained through melt-kneading. 4. The polyphenylene sulfide film according to claim 3, wherein the polyphenylene sulfide film is obtained by being phase-separated under non-shearing after discharging after being compatible under shearing during melt kneading. A stretched polyphenylene sulfide film obtained by stretching the polyphenylene sulfide film according to any one of claims 1 to 4 while being heat-treated, and further heat-treating the stretched polyphenylene sulfide film. In the stretched polyphenylene sulfide, a polyphenylene sulfide resin and a polyester resin mainly composed of polyethylene terephthalate form a biphasic continuous structure having a structural period of 0.001 to 2 μm , or a dispersed structure having a distance between particles of 0.001 to 2 μm. The stretched polyphenylene sulfide film according to claim 5, wherein A method for producing a polyphenylene sulfide film comprising a polyphenylene sulfide resin and a polyphenylene sulfide resin composition comprising a polyester resin comprising polyethylene terephthalate as a main structural unit, wherein the polyphenylene sulfide resin and the polyester resin are phase-separated by spinodal decomposition. A method for producing a polyphenylene sulfide film, comprising forming a two-phase continuous structure having a structural period of 0.001 to 2 μm or a dispersed structure having a distance between particles of 0.001 to 2 μm. 8. The method for producing a polyphenylene sulfide film according to claim 7, wherein spinodal decomposition is induced by melt-kneading the polyphenylene sulfide resin composition. 9. The production of a polyphenylene sulfide film according to claim 8, wherein the polyphenylene sulfide resin and the polyester resin mainly comprising polyethylene terephthalate are compatibilized under shear during melt-kneading and then phase-separated under non-shear after discharge. Method. 10. The production of a polyphenylene sulfide film according to claim 9, wherein the polyphenylene sulfide film phase-separated until the desired structural period or interparticle distance is reached under non-shearing after the discharge is rapidly cooled to fix the structure. Method. A polyphenylene sulfide film produced by the method for producing a polyphenylene sulfide film according to any one of claims 7 to 10, and then stretched while heat-treating the polyphenylene sulfide film, and further heat-treated. A method for producing a sulfide film.