JP4411835B2 - Process for producing polyphenylene sulfide film roll and condenser - Google Patents

Description

【００１３】
かかる成分が２０モル％未満ではポリマーの結晶性、軟化点等が低くなり、得られるフィルムの耐熱性、寸法安定性および機械的特性などを損なう。繰り返し単位の２０モル％未満であれば、共重合可能なスルフィド結合を含有する単位が含まれていても差し支えない。該重合体の共重合の仕方はランダム、ブロックを問わない。
【００１４】
本発明においてポリフェニレンサルファイド樹脂組成物とは上記ポリフェニレンサルファイド（好ましくはポリ−ｐ−フェニレンサルファイド）を９０重量％以上含む樹脂組成物をいう。樹脂組成物中の残りの１０重量％未満は、ポリフェニレンサルファイド以外のポリマーおよび／または充填剤、滑剤、着色剤、紫外線吸収剤、帯電防止剤、酸化防止剤等の添加剤であってもかまわない。また、本発明のポリフェニレンサルファイド樹脂組成物の溶融粘度は温度３００℃、せん断速度２００ｓｅｃ^-1のもとで１００〜５００００ポイズ、さらには５００〜１２０００ポイズ）の範囲が製膜性の面で好ましい。
【００１５】
本発明のポリフェニレンサルファイドフィルムとは上記のポリフェニレンサルファイド樹脂組成物を溶融成形した未延伸フィルム、一軸延伸および二軸延伸フィルムであるが、コンデンサー用途には二軸延伸フィルムを用いるのが好ましい。該フィルムの厚さは０．５〜１２μｍの範囲が本発明の目的を効果的に達成する点で好ましい。また、易接着効果を持たせる目的で、コロナ処理、プラズマ処理、プライマー処理を単体または複合の表面処理が施されてもよい。
【００１６】
本発明におけるフィルムの長手方向の熱伸び率とは短冊状のフィルムを熱伸び測定機にてフィルム断面積に対して１．０Ｋｇ／ｍｍ²の荷重をかけて１０℃／分で３０℃から１５０℃まで昇温し連続的にフィルムの長手方向の寸法変化を測定したとき、測定前のフィルムに対しての７０℃以上、１５０℃以下での寸法変化率である。
【００１７】
該熱伸び率が０．１％を超えると蒸着時の熱によるフィルムの伸びが大きく、蒸着機の冷却キャン上でフィルムにシワが生じ、蒸着金属の潜熱でシワが固定されて金属化フィルムにシワが残って平面性が悪くなる。このためにコンデンサー用テープなどを製造すると、寸法精度が悪くなり、例えばマージン部（非蒸着部）の幅が変動してコンデンサーの耐電圧不良の原因となる。
【００１８】
本発明において巻長さ３０００ｍ位置での巻硬度とは、フィルムロールを巻き戻して巻長さ３０００ｍ位置でのフィルムロール表面をゴム硬度計にて測定した巻硬度である。本発明のポリフェニレンサルファイドフィルムロールにおいては、熱処理前後の巻長さ３０００ｍ位置での巻硬度を共に８６°以上９５°以下、好ましくは８７°以上９４°以下とするものである。
【００１９】
熱処理前の該巻硬度が８６°未満であるとフィルム層間の空気の噛み込み量が多く、熱処理した際にフィルムの変形によりシワが発生する。一方、該巻硬度が９５°を超えると熱処理や長時間保管することで巻締まりによりフィルム層間の密着力が強くなるため、蒸着時のフィルム巻出しで剥離するショックでフィルム切れが発生したり、剥離帯電が大きくなるためフィルムのすべり性が下がり、冷却ロール上でシワが発生し熱負けの原因となる。
【００２０】
熱処理後の巻硬度が８６°未満であるとフィルム層間の空気の噛み込み量が多いため、真空蒸着工程においてロールからフィルムを巻出す際にフィルムが揺らぎ、フィルム切れが多発すると同時に、幅変動が大きくなり、マージン部の寸法精度が悪化するためコンデンサー耐電圧不良の原因となる。熱処理後のロールの巻硬度が９５°を超えると剥離帯電が大きくなるためフィルムのすべり性が下がり、冷却ロール上でシワが発生し熱負けの原因となる。
【００２１】
ここで巻硬度をかかる範囲にするにはフィルム巻き取り時の張力および／またはタッチロールの圧力等の条件を適切に制御することで達成できる。
【００２２】
本発明においてコンデンサーとは電気回路の受信回路素子の一種で、誘電体を挟んで導体からなる一対の電極を設けることにより、両電極間に一定の静電気量を与えるものを意味し、蓄電器、キャパシタなどと呼ばれるものである。
【００２３】
次に本発明のポリフェニレンサルファイドフィルムロールの製造方法の好ましい例を説明する。
【００２４】
先ず、ポリフェニレンサルファイドフィルムの製造方法について述べる。
【００２５】
ポリフェニレンサルファイドの重合方法としては、硫化アルカリとジハロベンゼンを極性溶媒中で高温高圧下に反応させる方法を用いる。特に、硫化ナトリウムとジクロルベンゼンをＮ−メチルピロリドン等のアミド系高沸点溶媒中で反応させるのが好ましい。重合度を調整するために苛性アルカリ、カルボン酸アルカリ金属塩などの重合助剤を添加して、２３０〜２８０℃の温度で反応させるのが最も好ましい。重合系内の圧力および重合時間は、使用する助剤の種類や量および所望する重合度等によって適宜決定される。
【００２６】
重合を終わったポリマーを例えばＮ−メチルピロリドンのようなポリフェニレンサルファイドと親和性のある溶媒で高温洗浄した後に水洗、乾燥することでポリフェニレンサルファイド粉末が得られる。
【００２７】
このようにして得られた樹脂粉末に例えば無機や有機の添加剤をヘンシェルミキサー等でブレンドし、押出機、好ましくは一段以上のベント孔を有する押出機に供給して２９０〜３６０℃の温度で溶融混練して適当な口金から押し出してポリフェニレンサルファイド樹脂組成物を得ることができる。
【００２８】
上記樹脂組成物を溶融押出装置に供給し、該樹脂組成物の融点以上、好ましくは２９０〜３６０℃の温度で溶融して、スリット状のダイから押し出し、回転する金属ドラム上でキャストするなどの方法で急冷して未延伸、無配向のフィルムを得る。
【００２９】
二軸延伸フィルムにするには、上記で得た未延伸フィルムを逐次二軸延伸法、同時二軸延伸法等の周知の方法を用いることができるが、ロール群によってフィルム長手方向に延伸した後にテンターによって幅方向に延伸する、いわゆる逐次二軸延伸法によるのが好ましい。延伸の条件は本発明で注目する熱収縮率を目的の範囲とするために８５〜１１０℃の温度で、各１．５〜４．５倍の倍率で行うのが好ましい。
【００３０】
次に、このようにして得られた延伸フィルムを通常、定長あるいは１．５％以下の制限収縮下で熱処理をする。ここで熱処理は２４０℃〜２９０℃で１〜５０秒、さらには２５０℃〜２８５℃で３〜２０秒）で行うのが好ましい。
【００３１】
該延伸フィルムをワインダーにて円筒状のコアに巻き取る。
【００３２】
次に該フィルムロールを熱処理するが、注目するフィルムの熱伸び率および熱処理後のロールの巻長さ３０００ｍ位置での巻硬度を上記範囲に制御するためには２段階で下記条件で行う。
【００３３】
１段目は４０℃以上、６０℃未満の温度で２４時間以上、１００時間未満、さらには２４時間以上、５０時間未満の条件で行うのが好ましい。次に２段階目の熱処理としては０℃以上、４０℃未満の温度で３００時間以上、さらには５００時間以上の条件で行うのが好ましい。１段目、２段目の熱処理温度、時間がかかる好ましい範囲であると、熱処理の効果が適切で、注目する熱伸びを所望の範囲にすることが容易であり、一方、フィルムの平面性も良好で、巻締まりによるフィルム層間の密着力を抑制できるため、蒸着時のフィルム巻出しで剥離しにくく、フィルム切れが発生しにくく、剥離帯電が大きくなることを防げるためフィルムのすべり性が良好で、冷却ロール上でシワが発生しにくく熱負けが起こりにくくなる。
【００３４】
本発明においては上記のとおり熱処理を２段階で行うのがフィルムの平面性等を損なわずに熱伸びが大きくなるのを抑止できる点で好ましい。
【００３５】
次に本発明のコンデンサの製造方法について述べる。
【００３６】
コンデンサの内部電極として金属薄膜が用いられ、まず上述した本発明の積層フィルムを金属化する。金属化の方法は蒸着により行うが、注目する熱伸び率や巻硬度が本発明の範囲を外れていると熱負けやフィルム切れは多発する。蒸着する金属はアルミニウムを主たる成分とする金属が好ましい。金属化する際、予め金属化する側のフィルム表面にコロナ放電処理、プラズマ処理などの処理によって金属薄膜とフィルムとの密着力を向上させることもできる。あるいは金属化後に対向電極が短絡しないようにテープマスク、オイルマージンあるいはレーザービーム等により非金属化部分（いわゆるマージン）を設けることもできる。その後、一方の端にマージン部分がくるように細幅のテープ状にスリットすることもある。
【００３７】
次にコンデンサ素子を製造する。巻回型コンデンサを得る場合は、金属化フィルムを一方の端にマージン部分がくるように細幅のテープ状にスリットした２枚重ねて、あるいは両面金属化フィルムにコーティング法などで第２の誘電体を設けた１枚の複合フィルムを巻回する方法もある。
【００３８】
積層型コンデンサの場合は大径のドラムあるいは平板に巻回してコンデンサ母素子を得る。
【００３９】
巻回型コンデンサを製造する場合は、上記のようにして得たコンデンサ母素子をプレス成形するのが一般的である。このとき、１００℃以上フィルムの融点以下の温度に加熱することもできる。その後、外部電極の取り付け工程（金属溶射、導電性樹脂等による）、必要なら樹脂または油含浸工程、リード付きタイプのコンデンサとするときはリード線の取り付け工程、外装工程を経てコンデンサを得ることができる。
【００４０】
積層型コンデンサの場合は大径のドラムあるいは平板に巻回下、母素子を熱処理する、あるいはリング等で締め付ける、あるいは平行平板等でプレスするなどフィルムの厚さ方向に圧力を加えて成形する。その際の温度範囲は常温からフィルムの融点以下である。この後、外部電極の取り付け工程（金属溶射、導電性樹脂による）、個々の素子切り出し工程、必要なら樹脂または油含浸工程を経てコンデンサを得ることができる。
［特性の評価方法］
本発明の記述に用いた、特性の評価方法およ評価基準を述べる。
（１）熱伸び率
フィルムを幅５ｍｍ、長さ２０ｍｍの短冊状に切り取り真空理工（株）製ＴＭＳ９０００熱伸び測定器にて、フィルム断面積に対して１．０Ｋｇ／ｍｍ²の加重をかけ、昇温速度１０℃／分で３０℃から１５０℃まで加熱し、連続的にフィルムの長手方向の寸法変化を測定して７０℃以上、１５０℃以下での寸法変化率を熱伸び率とした。
（２）巻長さ３０００ｍ位置でのフィルムロールの巻硬度
フィルムロールを巻きほぐし、巻長さ３０００ｍ位置でのフィルムロール表層について、巻硬度を高分子計器株式会社製Ｃ型ゴム硬度計にてフィルム幅５０ｍｍごとに測定した平均値を巻長さ３０００ｍ位置でのフィルムロールの巻硬度とした。
（３）熱負け
日本真空技研株式会社製の連続巻取り式片面蒸着機を用いて、幅５００ｍｍのフィルム試料にアルミニウムを蒸着した。このとき冷却キャン前後のフィルム張力３Ｋｇ／ｍｍ²、冷却キャン内循環の冷媒温度を−３０℃とし、９ｍｍ幅の蒸着部と１ｍｍ幅の非蒸着部を交互にストライプ状に蒸着した。蒸着後のフィルムを観察し、次の基準で熱負けの程度を判定した。
【００４１】
○：金属化フィルムの縦方向に走るシワが３本以下、
△：金属化フィルムの縦方向に走るシワ４本以上、１０本以下であり、マージン形成部の寸法変動が若干あるが後工程には支障がない、
×：金属化フィルムの縦方向に走るシワが１１本以上あり、マージン形成部の寸法変動が大きく、後工程に支障をきたす。
（４）フィルム切れ
日本真空技研株式会社製の連続巻取り式片面蒸着機を用いて、幅５００ｍｍのフィルム試料にアルミニウムを蒸着した。このとき冷却キャン前後のフィルム張力３Ｋｇ／ｍｍ²、冷却キャン内循環の冷媒温度を−３０℃とし、９ｍｍ幅の蒸着部と１ｍｍ幅の非蒸着部を交互にストライプ状に蒸着した。フィルム合計長さ１００００ｍまで蒸着するまでのフィルム切れの程度を次の基準で判断した。
【００４２】
○：蒸着時のフィルム切れが１回以下、
△：蒸着時のフィルム切れが、２回または３回あったが、支障はきたさない、×：蒸着時のフィルム切れが４回以上あり、作業能率および歩留まりが著しく低下する。
（５）コンデンサ耐電圧不良
上記（３）と同様の方法で金属化フィルムを作製した後、次の条件で巻回型コンデンサを作製した。
[コンデンサ作製条件]
アルミニウム蒸着 ： ２Ω／□
フィルム幅 ： ９ｍｍ
マージン幅 ： １ｍｍ
静電容量 ： ０．３５μＦに制御
プレス条件
温度 ： １５０℃
圧力 ： ２５Ｋｇ／ｃｍ²
時間 ： ０．５ｈｏｕｒ
この巻回型コンデンサについて、直流耐圧試験器（春日電機（株）製）で印可電圧昇圧速度１００Ｖ／ｓｅｃで測定し、電流が１０ｍＡ以上流れ、電圧上昇が止まったものを不良とした。コンデンサ１００個を測定し、不良個数の百分率（％）で表し、次の基準で判断した。
【００４３】
○：相対偏差２％未満
△：相対偏差３〜５％
×：相対偏差５％以上
（６）コンデンサ素子加工性
上記（５）と同様にしてコンデンサ素子を作製し、目視により素子の形状を確認し、次の基準で判断した。
【００４４】
○：コンデンサ素子のフィルムのずれ、変形がなく、後の工程に全く支障がない、 △：コンデンサ素子のフィルムのずれ、変形は若干あるが後の工程で問題がない、 ×：コンデンサ素子のフィルムのずれ、変形が大きく、後の工程に支障を来す。
【００４５】
【実施例】
次に本発明を実施例を挙げて詳細に説明する。
実施例１
東レ（株）製ポリ−ｐ−フェニレンサルファイド粉末（Ｔ１８８１）をＮ−メチルピロリドンで２回洗浄した。さらに、該ポリ−ｐ−フェニレンサルファイド粉末に平均粒径０．５μｍの炭酸カルシウム粒子０．５重量％をヘンシェルミキサーでブレンドした後、３０ｍｍ孔径の二軸押出機に供給し、３２０℃の温度で２ｍｍ径の円形ダイスからガット状押出成形し、水冷した後カッターで３ｍｍ長に切断した。
【００４６】
得られたポリ−ｐ−フェニレンサルファイド樹脂組成物を１８０℃、１０ｍｍＨｇの減圧下でミキサーでかき混ぜながら５時間乾燥した。
【００４７】
該樹脂組成物を９０ｍｍ孔径のエクストルーダで３３０℃の温度で押し出し、９００ｍｍ幅、リップ間隙１ｍｍの口金でシート状に成形した後、６０℃の温度に制御した金属ドラムでキャストして未延伸フィルムを得た。
【００４８】
得られた未延伸フィルムを逐次二軸延伸法で長手方向に３．５倍、幅方向に３．３倍延伸した。延伸温度は長手方向、幅方向とも９９℃であった。さらに幅方向に延伸したテンターに後続する熱処理ゾーンで２７０℃で１０秒間熱処理をした。また、幅方向のリラックス率は５％とした。 得られた二軸延伸ポリ−ｐ−フェニレンサルファイドフィルムの平均厚みは２．０μｍであった。
【００４９】
該フィルムを張力８０Ｎ、タッチロール圧力１００Ｎ／ｍで巻き取った後、張力２５Ｎ、タッチロール圧３５０Ｎ／ｍで５００ｍｍ幅にスリットを行い、巻長さを１００００ｍとした。得られたポリフェニレンサルファイドフィルムロールの巻終わり位置での巻硬度は９１°であった。該フィルムロールを巻きほぐし、熱処理前の巻長さ３０００ｍ位置での巻硬度を測定したところ９２°であった。
【００５０】
次に該フィルムロールを巻き戻して５０℃、２４時間エージングした後、さらに２５℃で１０００時間エージングを行った。得られた熱処理後のフィルムロールを巻きほぐし、熱処理後の巻長さ３０００ｍ位置での巻硬度を測定したところ９３°であった。該フィルムの長手方向の熱伸び率は０．０１〜０．０４％であった。蒸着時の熱負け、フィルム切れが解消すると同時にコンデンサ素子加工性も向上し、コンデンサとしても優れた特性を有していた。得られたフィルムロールの特性を表１に示した。
【００５１】
【表１】

【００５２】
実施例２
ポリフェニレンサルファイドフィルムロールを実施例１と同様の方法で得た。次に該フィルムロールを巻き戻して４０℃で２４時間エージングした後、さらに０℃で５００時間エージングを行った。得られた熱処理後のフィルムロールの巻長さ３０００ｍ位置での巻硬度は９２°であり、フィルム長手方向の熱伸び率は０．０３〜０．０９％であった。蒸着時の熱負け、フィルム切れが解消すると同時にコンデンサ素子加工性も向上し、コンデンサとしても優れた特性を有していた。得られたフィルムロールの特性を表１に示した。
実施例３
ポリフェニレンサルファイドフィルムロールを実施例１と同様の方法で得た。次に該フィルムロールを巻き戻して６０℃で１００時間エージングを行った後、さらに３０℃で１０００時間エージングを行った。得られた熱処理後のフィルムロールの巻長さ３０００ｍ位置での巻硬度は９４°であり、フィルム長手方向の熱伸び率は０．０１〜０．０３％であった。蒸着時の熱負け、フィルム切れが解消すると同時にコンデンサ素子加工性も向上し、コンデンサとしても優れた特性を有していた。得られたフィルムロールの特性を表１に示した。
実施例４
スリット時の張力を３５Ｎにした以外は実施例１と同様の方法でポリフェニレンサルファイドフィルムロールを得た。該フィルムロールの巻長さを１００００ｍとしたときの巻終わり位置での巻硬度は９２°であり、巻長さ３０００ｍ位置での巻硬度は９３°であった。次に該フィルムロールを巻き戻してさらに実施例１と同様の方法で熱処理を行った。熱処理後のフィルムロールの巻長さ３０００ｍ位置での巻硬度は９４°で、フィルム長手方向の熱伸び率は０．０３〜０．０８％であった。蒸着時の熱負け、フィルム切れが解消すると同時にコンデンサ素子加工性も向上し、コンデンサとしても優れた特性を有していた。得られたフィルムロールの特性を表１に示した。
実施例５
スリット時の張力を２０Ｎにした以外は実施例１と同様の方法でポリフェニレンサルファイドフィルムロールを得た。該フィルムロールの巻長さを１００００ｍとしたときの巻終わり位置での巻硬度は８６°であり、巻長さ３０００ｍ位置での巻硬度は８８°であった。次に該フィルムロールを巻き戻してさらに実施例１と同様の方法で熱処理を行った。熱処理後のフィルムロールの巻長さ３０００ｍ位置での巻硬度は８９°で、フィルム長手方向の熱伸び率は０．０１〜０．０３％であった。蒸着時の熱負け、フィルム切れが解消すると同時にコンデンサ素子加工性も向上し、コンデンサとしても優れた特性を有していた。得られたフィルムロールの特性を表１に示した。
比較例１
ポリフェニレンサルファイドフィルムロールを実施例１と同様の方法で得た。次に該フィルムロールを巻き戻して７０℃で５０時間エージングを行った後、さらに３０℃で５００時間エージングを行った。得られた熱処理後のフィルムロールの巻長さ３０００ｍ位置での巻硬度は９６°であり、フィルム長手方向の熱伸び率は０．０３〜０．０８％であった。このフィルムロールは過度の熱処理により熱処理後のロールの巻硬度が９５°以上になったためフィルム層間の密着力が上がり、蒸着時の巻き出しの際の剥離帯電が大きくなった。このため蒸着時にフィルム切れが多発した。得られたフィルムロールの特性を表１に示した。
比較例２
ポリフェニレンサルファイドフィルムロールを実施例１と同様の方法で得た。次に該フィルムロールを巻き戻して３０℃で１０００時間エージングを行った。得られた熱処理後のフィルムロールの巻長さ３０００ｍ位置での巻硬度は９２°であり、フィルム長手方向の熱伸び率は０．０５〜０．１２％であった。熱処理後のフィルムの長手方向の伸び率が大であるため冷却キャンからフィルムが浮いてしまい熱負けが多発した。また巻回時にシワが発生し素子加工性が悪かった。得られたフィルムロールの特性を表１に示した。
比較例３
ポリフェニレンサルファイドフィルムロールを実施例１と同様の方法で得た。次に該フィルムロールを巻き戻して６０℃で２４時間エージングを行った。得られた熱処理後のフィルムロールの巻長さ３０００ｍ位置での巻硬度は９３°であり、フィルム長手方向の熱伸び率は０．０４〜０．１１％であった。特公平５−４９０１９号公報に記載されている方法と同様の熱処理を行ったものであるが、長手方向の熱伸び率が大であるため冷却キャンからフィルムが浮いてしまい熱負けが多発した。得られたフィルムロールの特性を表１に示した。
比較例４
スリット時の張力を４０Ｎとした以外は実施例１と同様の方法でポリフェニレンサルファイドフィルムロールを得た。得られたフィルムロールの巻長さを１００００ｍとしたときの巻終わり位置での巻硬度は９６°であり、巻長さ３０００ｍ位置での巻硬度は９７°であった。次に該フィルムロールを巻き戻してさらに実施例１と同様の方法で熱処理を行った。熱処理後のフィルムロールの巻長さ３０００ｍ位置での巻硬度は９７°で、フィルム長手方向の熱伸び率は０．０５〜０．１０％であった。このフィルムロールは巻硬度が９５°以上になったためフィルム層間の密着力が上がり、蒸着時の巻き出しの際の剥離帯電が大きくなった。得られたフィルムロールの特性を表１に示した。
【００５３】
【発明の効果】
本発明により、蒸着加工工程での熱負けおよびフィルム切れを解消するとともにコンデンサー製造工程での加工性に優れた蒸着用ポリフェニレンサルファイドフィルムロールを提供することができた。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a polyphenylene sulfide film roll for vapor deposition. More particularly, a shall relates to a manufacturing method and a condenser using the same heat lost and the film breakage is less polyphenylene sulfide film roll at the time of evaporation.
[0002]
[Prior art]
Polyphenylene sulfide films have extremely excellent performances in terms of heat resistance, chemical resistance, electrical insulation, mechanical properties, etc., and are used for applications such as electrical insulation materials and release materials. In addition, it is used as a capacitor dielectric because of the stability of dielectric properties at high frequencies.
[0003]
It is known that a polyphenylene sulfide film is produced by a method described in Patent Document 1, for example.
[0004]
[Patent Document 1]
Japanese Patent Publication No. 45-3368 also discloses in Patent Document 2 and the like that aluminum is deposited on a biaxially oriented polyphenylene sulfide film to form a metallized film, and that the metallized film is used for applications such as capacitors. Has been.
[0005]
[Patent Document 2]
However, the conventional polyphenylene sulfide film has significantly reduced the yield due to heat loss during film deposition and film breakage.
[0006]
The heat loss mentioned here means that, for example, in the vacuum vapor deposition process of a capacitor or the like manufacturing process, when metal vapor deposition is performed with a winding vacuum vapor deposition machine, the film is likely to wrinkle on the cooling can of the vapor deposition machine, This is a phenomenon in which wrinkles are fixed by latent heat and the wrinkles remain on the metallized film, resulting in poor flatness. When a capacitor tape or the like is manufactured by cutting the metallized film in which the heat loss has occurred, the dimensional accuracy deteriorates, for example, the width of the margin part (non-deposition part) fluctuates, which causes a withstand voltage failure of the capacitor. There are adverse effects such as.
[0007]
Regarding measures against heat loss, for example, in Patent Document 3, in the longitudinal direction of the film, while applying a tension of 3 kg per square millimeter of cross-sectional area, the temperature was increased from 25 ° C. to 70 ° C. at a rate of 10 ° C./min. There is a description of a biaxially stretched polyphenylene sulfide film characterized in that the elongation in the longitudinal direction is 0.4% or less.
[0008]
[Patent Document 3]
However, even if the thermal elongation at this temperature is controlled, the heat applied to the film during the deposition is 70 ° C. or higher, so the heat loss is not completely eliminated and the effect is small. . In particular, in a long product of 3000 m or more, heat loss is still severe at the time of vapor deposition processing, and the yield of capacitor production is lowered. When used with a roll of less than 3000 m, the efficiency of vapor deposition processing is remarkably lowered. Moreover, since the rolls were tightened by heat treatment and the films were in close contact with each other, the film was frequently cut during unwinding.
[0009]
[Problems to be solved by the invention]
The object of the present invention is to eliminate the disadvantages of the above-described conventional polyphenylene sulfide film, that is, to eliminate heat loss and film breakage in the vapor deposition process, and to be excellent in workability in the capacitor manufacturing process. Is to provide.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the polyphenylene sulfide film roll for vapor deposition of the present invention has the following constitution. That is,
Makicho of the first stage the following polyphenylene sulfide film Makicho of 3000m above 10000m the winding hardness was O'by winding a to 95 ° 86 ° or more at 3000m is 40 ° C. or more, 24 hours or more at a temperature below 60 ° C., 100 Less than time, the second stage is a method for producing a polyphenylene sulfide film roll, wherein the second stage is heat-treated at a temperature of 0 ° C. or more and less than 40 ° C. for 300 hours or more, wherein the film is subjected to thermal elongation in the longitudinal direction of the film after the heat treatment This is a method for producing a polyphenylene sulfide film roll having a rate of 0.1% or less and a winding hardness of the film roll after the heat treatment at a winding length of 3000 m of 86 ° to 95 °.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, polyphenylene sulfide refers to a polymer comprising 80 mol% (preferably 90 mol% or more) of repeating units represented by the following [Chemical Formula 1].
[0012]
[Chemical 1]

[0013]
If this component is less than 20 mol%, the crystallinity, softening point and the like of the polymer are lowered, and the heat resistance, dimensional stability and mechanical properties of the resulting film are impaired. As long as it is less than 20 mol% of the repeating units, there may be a unit containing a copolymerizable sulfide bond. The copolymerization method of the polymer may be random or block.
[0014]
In the present invention, the polyphenylene sulfide resin composition refers to a resin composition containing 90% by weight or more of the polyphenylene sulfide (preferably poly-p-phenylene sulfide). The remaining less than 10% by weight in the resin composition may be a polymer other than polyphenylene sulfide and / or an additive such as a filler, a lubricant, a colorant, an ultraviolet absorber, an antistatic agent, and an antioxidant. . In addition, the melt viscosity of the polyphenylene sulfide resin composition of the present invention is preferably in the range of 100 to 50000 poise, more preferably 500 to 12000 poise at a temperature of 300 ° C. and a shear rate of 200 sec ⁻¹ in terms of film forming property.
[0015]
The polyphenylene sulfide film of the present invention is an unstretched film, a uniaxially stretched film and a biaxially stretched film obtained by melt-molding the above polyphenylene sulfide resin composition, but it is preferable to use a biaxially stretched film for capacitor applications. The thickness of the film is preferably in the range of 0.5 to 12 μm from the viewpoint of effectively achieving the object of the present invention. Further, for the purpose of providing an easy-adhesion effect, a single or composite surface treatment may be applied to the corona treatment, the plasma treatment, and the primer treatment.
[0016]
The thermal elongation rate in the longitudinal direction of the film in the present invention is a strip-like film subjected to a load of 1.0 Kg / mm ² with respect to the cross-sectional area of the film with a thermal elongation measuring device at 30 ° C. to 150 ° C. at 10 ° C./min. When the dimensional change in the longitudinal direction of the film is continuously measured by raising the temperature to 0 ° C., the dimensional change rate is from 70 ° C. to 150 ° C. with respect to the film before measurement.
[0017]
If the thermal elongation rate exceeds 0.1%, the film is stretched greatly by the heat during vapor deposition, wrinkles are generated on the cooling can of the vapor deposition machine, and the wrinkles are fixed by the latent heat of the vapor deposited metal to form a metallized film. Wrinkles remain and flatness deteriorates. For this reason, when a capacitor tape or the like is manufactured, the dimensional accuracy is deteriorated. For example, the width of the margin portion (non-deposition portion) fluctuates, causing a breakdown voltage failure of the capacitor.
[0018]
In the present invention, the winding hardness at a winding length of 3000 m is a winding hardness obtained by rewinding the film roll and measuring the surface of the film roll at a winding length of 3000 m with a rubber hardness meter. In the polyphenylene sulfide film roll of the present invention, the winding hardness at the position of 3000 m before and after heat treatment is 86 ° to 95 °, preferably 87 ° to 94 °.
[0019]
If the winding hardness before heat treatment is less than 86 °, the amount of air between the film layers is large, and wrinkles are generated due to deformation of the film during heat treatment. On the other hand, when the winding hardness exceeds 95 °, the adhesion between the film layers is strengthened by tightening the winding by heat treatment or storage for a long time. Since the peeling charge is increased, the slipperiness of the film is lowered, and wrinkles are generated on the cooling roll, causing heat loss.
[0020]
When the winding hardness after heat treatment is less than 86 °, the amount of air between the film layers is large, so that the film fluctuates when the film is unwound from the roll in the vacuum deposition process, and the film fluctuates frequently. It becomes larger and the dimensional accuracy of the margin portion deteriorates, which causes a capacitor withstand voltage failure. When the roll hardness of the roll after the heat treatment exceeds 95 °, the peeling electrification increases, the film slipperiness decreases, wrinkles are generated on the cooling roll, and heat loss is caused.
[0021]
Here, setting the winding hardness to such a range can be achieved by appropriately controlling conditions such as the tension at the time of winding the film and / or the pressure of the touch roll.
[0022]
In the present invention, a capacitor is a kind of a receiving circuit element of an electric circuit, and means that a constant amount of static electricity is provided between both electrodes by providing a pair of electrodes made of a conductor with a dielectric interposed therebetween. And so on.
[0023]
Next, the preferable example of the manufacturing method of the polyphenylene sulfide film roll of this invention is demonstrated.
[0024]
First, a method for producing a polyphenylene sulfide film will be described.
[0025]
As a polymerization method of polyphenylene sulfide, a method of reacting alkali sulfide and dihalobenzene in a polar solvent under high temperature and high pressure is used. In particular, it is preferable to react sodium sulfide and dichlorobenzene in an amide type high boiling point solvent such as N-methylpyrrolidone. In order to adjust the degree of polymerization, it is most preferable to add a polymerization aid such as caustic alkali or carboxylic acid alkali metal salt and to react at a temperature of 230 to 280 ° C. The pressure in the polymerization system and the polymerization time are appropriately determined depending on the type and amount of the auxiliary agent used and the desired degree of polymerization.
[0026]
The polymer after the polymerization is washed at a high temperature with a solvent having an affinity for polyphenylene sulfide, such as N-methylpyrrolidone, and then washed with water and dried to obtain a polyphenylene sulfide powder.
[0027]
The resin powder thus obtained is blended with, for example, an inorganic or organic additive using a Henschel mixer or the like, and supplied to an extruder, preferably an extruder having one or more vent holes at a temperature of 290 to 360 ° C. It can be melt kneaded and extruded from a suitable die to obtain a polyphenylene sulfide resin composition.
[0028]
The resin composition is supplied to a melt extrusion apparatus, melted at a temperature equal to or higher than the melting point of the resin composition, preferably 290 to 360 ° C., extruded from a slit-shaped die, and cast on a rotating metal drum. The film is rapidly cooled to obtain an unstretched, non-oriented film.
[0029]
In order to make a biaxially stretched film, a well-known method such as a sequential biaxial stretching method or a simultaneous biaxial stretching method can be used for the unstretched film obtained above, but after stretching in the film longitudinal direction by a roll group It is preferable to use a so-called sequential biaxial stretching method in which stretching is performed in the width direction by a tenter. The stretching conditions are preferably performed at a temperature of 85 to 110 ° C. and a magnification of 1.5 to 4.5 times in order to make the thermal shrinkage noted in the present invention within the target range.
[0030]
Next, the stretched film thus obtained is usually heat-treated at a constant length or under a limited shrinkage of 1.5% or less. Here, the heat treatment is preferably performed at 240 ° C. to 290 ° C. for 1 to 50 seconds, and further at 250 ° C. to 285 ° C. for 3 to 20 seconds.
[0031]
The stretched film is wound around a cylindrical core with a winder.
[0032]
Then heat treating the film roll, but intends line under the following conditions in two stages in order to the winding hardness at winding length 3000m position of the thermal elongation and after heat treatment roll of film of interest to control the above-mentioned range.
[0033]
The first stage is preferably performed at a temperature of 40 ° C. or more and less than 60 ° C. for 24 hours or more and less than 100 hours, and further for 24 hours or more and less than 50 hours. Next, the second stage heat treatment is preferably performed at a temperature of 0 ° C. or higher and lower than 40 ° C. for 300 hours or longer, and further 500 hours or longer. If the heat treatment temperature and the heat treatment temperature of the first stage and the second stage are within a preferable range, the effect of the heat treatment is appropriate, and it is easy to bring the target thermal elongation into a desired range, while the flatness of the film is also It is good and can suppress the adhesion between film layers due to winding tightening, so it is difficult to peel off by film unwinding at the time of vapor deposition, film breakage is difficult to occur, and it is possible to prevent the peeling charge from becoming large and the film has good sliding properties In addition, wrinkles are less likely to occur on the cooling roll, and heat loss is less likely to occur.
[0034]
In the present invention, it is preferable to perform the heat treatment in two stages as described above from the viewpoint that it is possible to suppress an increase in thermal elongation without impairing the flatness of the film.
[0035]
Next, a method for manufacturing the capacitor of the present invention will be described.
[0036]
A metal thin film is used as the internal electrode of the capacitor. First, the above-described laminated film of the present invention is metallized. Although the metallization method is performed by vapor deposition, heat loss and film breakage frequently occur when the thermal expansion rate and winding hardness of interest are outside the scope of the present invention. The metal to be deposited is preferably a metal mainly composed of aluminum. At the time of metallization, the adhesion between the metal thin film and the film can be improved by treatment such as corona discharge treatment or plasma treatment on the surface of the film to be metallized in advance. Alternatively, a non-metalized portion (so-called margin) can be provided by a tape mask, an oil margin, a laser beam or the like so that the counter electrode is not short-circuited after metallization. After that, the tape may be slit into a narrow tape shape so that a margin part comes to one end.
[0037]
Next, a capacitor element is manufactured. When obtaining a wound capacitor, the second dielectric is formed by stacking two metallized films that are slit into a narrow tape shape with a margin at one end or by coating the double-sided metallized film. There is also a method of winding a single composite film provided with a body.
[0038]
In the case of a multilayer capacitor, a capacitor mother element is obtained by winding it on a large-diameter drum or flat plate.
[0039]
When manufacturing a winding type capacitor, it is common to press-mold the capacitor base element obtained as described above. At this time, it can also heat to the temperature below 100 degreeC or more and the melting point of a film. After that, the external electrode mounting process (by metal spraying, conductive resin, etc.), if necessary, resin or oil impregnation process, when using a leaded type capacitor, the lead wire mounting process and the exterior process can be used to obtain the capacitor it can.
[0040]
In the case of a multilayer capacitor, it is molded by applying pressure in the thickness direction of the film, such as winding on a large-diameter drum or flat plate, heat-treating the mother element, tightening with a ring, or pressing with a parallel flat plate. The temperature range in that case is from normal temperature to below the melting point of the film. Thereafter, the capacitor can be obtained through an external electrode attaching step (metal spraying, using a conductive resin), individual element cutting steps, and if necessary, a resin or oil impregnation step.
[Characteristic evaluation method]
The characteristic evaluation method and evaluation criteria used in the description of the present invention will be described.
(1) The thermal elongation rate film was cut into a strip shape having a width of 5 mm and a length of 20 mm, and a load of 1.0 kg / mm ² was applied to the film cross-sectional area with a TMS9000 thermal elongation measuring instrument manufactured by Vacuum Riko Co., Ltd. The film was heated from 30 ° C. to 150 ° C. at a rate of temperature increase of 10 ° C./min, and the dimensional change in the longitudinal direction of the film was continuously measured. The dimensional change rate at 70 ° C. or higher and 150 ° C. or lower was defined as the thermal elongation rate.
(2) Winding hardness of the film roll at a winding length of 3000 m The film roll is unwound, and the winding hardness of the film roll surface layer at the winding length of 3000 m is measured with a C-type rubber hardness meter manufactured by Kobunshi Keiki Co., Ltd. The average value measured every width 50 mm was taken as the winding hardness of the film roll at a winding length of 3000 m.
(3) Heat loss Aluminum was vapor-deposited on a film sample having a width of 500 mm using a continuous winding single-side vapor deposition machine manufactured by Nippon Vacuum Engineering Co., Ltd. At this time, the film tension before and after the cooling can was 3 kg / mm ² , the refrigerant temperature in the cooling can circulation was −30 ° C., and the 9 mm wide vapor deposition part and the 1 mm wide non-evaporation part were alternately vapor deposited in stripes. The film after vapor deposition was observed, and the degree of heat loss was determined according to the following criteria.
[0041]
○: 3 or less wrinkles running in the vertical direction of the metallized film,
Δ: Wrinkles 4 or more and 10 or less running in the vertical direction of the metallized film, there is a slight dimensional variation in the margin forming portion, but there is no hindrance to the subsequent process.
X: There are 11 or more wrinkles running in the vertical direction of the metallized film, the dimensional variation of the margin forming part is large, and the post-process is hindered.
(4) Film breakage Aluminum was vapor-deposited on a film sample having a width of 500 mm using a continuous winding single-side vapor deposition machine manufactured by Nippon Vacuum Engineering Co., Ltd. At this time, the film tension before and after the cooling can was 3 kg / mm ² , the refrigerant temperature in the cooling can circulation was −30 ° C., and the 9 mm wide vapor deposition part and the 1 mm wide non-evaporation part were alternately vapor deposited in stripes. The degree of film breakage until vapor deposition to a total film length of 10,000 m was judged according to the following criteria.
[0042]
○: Film breakage during deposition is less than 1 time,
Δ: Film breakage during vapor deposition was 2 or 3 times, but no problem occurred. ×: Film breakage during vapor deposition was 4 times or more, and work efficiency and yield were significantly reduced.
(5) Capacitor withstand voltage failure After a metallized film was produced by the same method as in (3) above, a wound capacitor was produced under the following conditions.
[Capacitor manufacturing conditions]
Aluminum deposition: 2Ω / □
Film width: 9mm
Margin width: 1mm
Capacitance: 0.35 μF controlled Pressing condition temperature: 150 ° C.
Pressure: 25 kg / cm ²
Time: 0.5hour
The winding type capacitor was measured with a DC withstand voltage tester (manufactured by Kasuga Denki Co., Ltd.) at an applied voltage boosting rate of 100 V / sec. A current that flowed 10 mA or more and the voltage increase stopped was regarded as defective. 100 capacitors were measured, expressed as a percentage (%) of the number of defects, and judged according to the following criteria.
[0043]
○: Relative deviation less than 2% △: Relative deviation 3-5%
X: Relative deviation 5% or more (6) Capacitor element workability A capacitor element was produced in the same manner as in (5) above, the shape of the element was confirmed by visual observation, and judged according to the following criteria.
[0044]
○: There is no displacement or deformation of the capacitor element film and there is no problem in the subsequent process. Δ: There is a slight displacement or deformation of the capacitor element film, but there is no problem in the subsequent process. Deviation and deformation are large, which hinders later processes.
[0045]
【Example】
Next, the present invention will be described in detail with reference to examples.
Example 1
Poly-p-phenylene sulfide powder (T1881) manufactured by Toray Industries, Inc. was washed twice with N-methylpyrrolidone. Further, 0.5% by weight of calcium carbonate particles having an average particle size of 0.5 μm were blended with the poly-p-phenylene sulfide powder using a Henschel mixer, and then supplied to a 30 mm pore diameter twin screw extruder at a temperature of 320 ° C. A 2 mm diameter circular die was extruded in a gut shape, cooled with water, and then cut into 3 mm lengths with a cutter.
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The obtained poly-p-phenylene sulfide resin composition was dried for 5 hours while stirring with a mixer under reduced pressure of 180 ° C. and 10 mmHg.
[0047]
The resin composition was extruded at a temperature of 330 ° C. with a 90 mm pore size extruder, formed into a sheet shape with a base having a width of 900 mm and a lip gap of 1 mm, and then cast with a metal drum controlled to a temperature of 60 ° C. to form an unstretched film. Obtained.
[0048]
The obtained unstretched film was stretched 3.5 times in the longitudinal direction and 3.3 times in the width direction by a sequential biaxial stretching method. The stretching temperature was 99 ° C. in both the longitudinal direction and the width direction. Further, heat treatment was performed at 270 ° C. for 10 seconds in a heat treatment zone following the tenter stretched in the width direction. The relaxation rate in the width direction was 5%. The average thickness of the obtained biaxially stretched poly-p-phenylene sulfide film was 2.0 μm.
[0049]
The film was wound up at a tension of 80 N and a touch roll pressure of 100 N / m, and then slit at a width of 500 mm at a tension of 25 N and a touch roll pressure of 350 N / m, so that the winding length was 10,000 m. The winding hardness at the winding end position of the obtained polyphenylene sulfide film roll was 91 °. The film roll was unwound and the winding hardness at a position of 3000 m before the heat treatment was measured and found to be 92 °.
[0050]
Next, the film roll was rewound and aged at 50 ° C. for 24 hours, and further aged at 25 ° C. for 1000 hours. The obtained heat-treated film roll was unwound and the winding hardness at a position of 3000 m after the heat treatment was measured to be 93 °. The thermal elongation rate in the longitudinal direction of the film was 0.01 to 0.04%. The heat loss during film deposition and film breakage were eliminated, and at the same time, the processability of the capacitor element was improved, and the capacitor had excellent characteristics. The characteristics of the obtained film roll are shown in Table 1.
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[Table 1]

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Example 2
A polyphenylene sulfide film roll was obtained in the same manner as in Example 1. Next, the film roll was rewound and aged at 40 ° C. for 24 hours, and then further aged at 0 ° C. for 500 hours. The film roll after the heat treatment had a winding hardness of 92 ° at a winding length of 3000 m, and the thermal elongation in the longitudinal direction of the film was 0.03 to 0.09%. The heat loss during film deposition and film breakage were eliminated, and at the same time, the processability of the capacitor element was improved, and the capacitor had excellent characteristics. The characteristics of the obtained film roll are shown in Table 1.
Example 3
A polyphenylene sulfide film roll was obtained in the same manner as in Example 1. Next, the film roll was rewound and aged at 60 ° C. for 100 hours, and then further aged at 30 ° C. for 1000 hours. The winding hardness of the obtained film roll after heat treatment at a winding length of 3000 m was 94 °, and the thermal elongation in the longitudinal direction of the film was 0.01 to 0.03%. The heat loss during film deposition and film breakage were eliminated, and at the same time, the processability of the capacitor element was improved, and the capacitor had excellent characteristics. The characteristics of the obtained film roll are shown in Table 1.
Example 4
A polyphenylene sulfide film roll was obtained in the same manner as in Example 1 except that the tension at the time of slitting was 35N. The winding hardness at the winding end position when the winding length of the film roll was 10,000 m was 92 °, and the winding hardness at the winding length of 3000 m was 93 °. Next, the film roll was rewound and further subjected to heat treatment in the same manner as in Example 1. The winding hardness of the film roll after the heat treatment at a winding length of 3000 m was 94 °, and the thermal elongation in the longitudinal direction of the film was 0.03 to 0.08%. The heat loss during film deposition and film breakage were eliminated, and at the same time, the processability of the capacitor element was improved, and the capacitor had excellent characteristics. The characteristics of the obtained film roll are shown in Table 1.
Example 5
A polyphenylene sulfide film roll was obtained in the same manner as in Example 1 except that the tension at the time of slitting was 20N. The winding hardness at the winding end position when the winding length of the film roll was 10,000 m was 86 °, and the winding hardness at the winding length of 3000 m was 88 °. Next, the film roll was rewound and further subjected to heat treatment in the same manner as in Example 1. The winding hardness of the film roll after the heat treatment at a winding length of 3000 m was 89 °, and the thermal elongation in the longitudinal direction of the film was 0.01 to 0.03%. The heat loss during film deposition and film breakage were eliminated, and at the same time, the processability of the capacitor element was improved, and the capacitor had excellent characteristics. The characteristics of the obtained film roll are shown in Table 1.
Comparative Example 1
A polyphenylene sulfide film roll was obtained in the same manner as in Example 1. Next, the film roll was rewound and aged at 70 ° C. for 50 hours, and then further aged at 30 ° C. for 500 hours. The winding hardness of the obtained film roll after heat treatment at a winding length of 3000 m was 96 °, and the thermal elongation in the film longitudinal direction was 0.03 to 0.08%. Since the roll hardness of the roll after heat treatment became 95 ° or more due to excessive heat treatment, the adhesion between the film layers was increased, and the peeling charge at the time of unwinding during vapor deposition was increased. For this reason, film breakage occurred frequently during the deposition. The characteristics of the obtained film roll are shown in Table 1.
Comparative Example 2
A polyphenylene sulfide film roll was obtained in the same manner as in Example 1. Next, the film roll was rewound and aged at 30 ° C. for 1000 hours. The film roll after heat treatment had a winding hardness of 92 ° at a winding length of 3000 m, and the thermal elongation in the film longitudinal direction was 0.05 to 0.12%. Since the elongation in the longitudinal direction of the film after the heat treatment was large, the film floated from the cooling can and heat loss occurred frequently. In addition, wrinkles occurred during winding, and the device processability was poor. The characteristics of the obtained film roll are shown in Table 1.
Comparative Example 3
A polyphenylene sulfide film roll was obtained in the same manner as in Example 1. Next, the film roll was rewound and aged at 60 ° C. for 24 hours. The film roll after heat treatment had a winding hardness of 93 ° at a winding length of 3000 m, and the thermal elongation in the film longitudinal direction was 0.04 to 0.11%. Although the heat treatment similar to the method described in Japanese Patent Publication No. 5-49019 was performed, the thermal expansion rate in the longitudinal direction was large, so that the film floated from the cooling can and heat loss occurred frequently. The properties of the obtained film roll are shown in Table 1.
Comparative Example 4
A polyphenylene sulfide film roll was obtained in the same manner as in Example 1 except that the tension at the time of slitting was 40 N. When the winding length of the obtained film roll was 10000 m, the winding hardness at the winding end position was 96 °, and the winding hardness at the winding length of 3000 m was 97 °. Next, the film roll was rewound and further subjected to heat treatment in the same manner as in Example 1. After the heat treatment, the film roll had a winding hardness of 97 ° at a winding length of 3000 m, and the thermal elongation in the film longitudinal direction was 0.05 to 0.10%. Since the film roll had a winding hardness of 95 ° or more, the adhesion between the film layers increased, and the peeling charge at the time of unwinding during vapor deposition increased. The properties of the obtained film roll are shown in Table 1.
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【The invention's effect】
By this invention, the polyphenylene sulfide film roll for vapor deposition which was excellent in the workability in a capacitor | condenser manufacturing process was able to be provided while eliminating the heat loss and film break in a vapor deposition process.

Claims (2)

A polyphenylene sulfide film having a winding length of 3000 m or more and 10000 m or less wound at a winding length of 3000 m and a winding hardness of 86 ° to 95 ° at the first stage is 24 ° C. or more at a temperature of 40 ° C. or more and less than 60 ° C. for 100 hours or more. Less than time, the second stage is a method for producing a polyphenylene sulfide film roll, wherein the second stage is heat-treated at a temperature of 0 ° C. or more and less than 40 ° C. for 300 hours or more, wherein the film is subjected to thermal elongation in the longitudinal direction of the film after the heat treatment The manufacturing method of the polyphenylene sulfide film roll whose rate is 0.1% or less and whose winding hardness in 3000 m of winding length of the film roll after the said heat processing is 86 degrees or more and 95 degrees or less. A capacitor formed by winding or laminating a metallized polyphenylene sulfide film obtained by vapor-depositing a metal layer on one side or both sides of a polyphenylene sulfide film wound from a polyphenylene sulfide film roll produced by the method according to claim 1.