JP3860359B2 - Polyimide film and method for producing the same - Google Patents

Description

【００２５】
および以下の構造式を持つオキシジフタル酸二無水物（以下、ＯＤＰＡという）
【００２６】
【化２】

【００２７】
ジアミンとして、以下の構造式を持つｐ−フェニレンジアミン（以下、ＰＤＡという）
【００２８】
【化３】

【００２９】
および以下の構造式を持つ４，４’−ジアミノジフェニルエーテル（以下、ＯＤＡという）
【００３０】
【化４】

【００３１】
を用いる。上記のモノマーを有機溶剤に溶解し、重合反応させて本発明にかかるポリイミドフィルムを製造するために用い得るポリアミド酸を得る。
【００３２】
以下ＴＭＨＱは、ＰＤＡとの組み合わせにおいて、棒状構造をとり、フィルムの高弾性が顕現され、主鎖構造上エステル結合のため熱的にはやや柔軟であることから、例えばピロメリット酸のみを用いた場合等に比べて線膨張係数が極端に下がることがなくなる。また、エステル結合がイミド環の分極を緩和し、吸水率を下げ吸水膨張率を下げる効果も有する。
【００３３】
ところが、ＴＭＨＱは、ＰＤＡとの組み合わせでは、構造的に硬すぎ、線膨張係数も依然低く、また靭性が不十分である。ジアミノジフェニルエーテルを共重合することによっても、依然一定以上の弾性率を得ようとすると線膨張係数は下がりすぎ、また靭性も不十分である。
【００３４】
ＯＤＰＡを用いて、ＰＤＡとジアミノジフェニルエーテルとを重合させ、適度に高い弾性率と銅との組み合わせにおいて不都合のない適度な線膨張係数、また十分な靭性等を実現させ得る。ただし、ＯＤＰＡだけでは吸水率そのものはさほど下がらず、吸湿特性を下げてかつ諸特性を好ましく保つにはＴＭＨＱをさらに共重合する、本発明の構成は、非常に有効である。
【００３５】
さらに、ＯＤＰＡおよびＴＭＨＱの組み合わせで実現できる好ましい他の特性を保持したまま、かつ、３００℃以上４００℃以下の温度における２００ＭＰａ以上という高い貯蔵弾性率を有する本発明の構成は、非常に有効である。
【００３６】
本発明のモノマー投入順序により、３００℃以上４００℃以下の温度における２００ＭＰａ以上という高い貯蔵弾性率を有するポリイミドフィルムを作製する本発明の構成は、非常に有効である。
【００３７】
フィルム作製時、フィルムをたるませることなく安定的に作製するためには、３００℃以上４００℃以下の温度における貯蔵弾性率は、２００ＭＰａ以上、好ましくは４００Ｍａ以上、さらに好ましくは６００ＭＰａ以上という高い貯蔵弾性率を有することが好ましい。３００℃以上４００℃以下の温度における貯蔵弾性率が２００ＭＰａ以下である場合には、フィルム製造の条件によっては、フィルムがたるむ可能性が有り、好ましくない。
【００３８】
ポリアミド酸の重合には種々の有機溶剤が使用可能であるが、使用する有機溶剤の種類によって本発明の効果が大きく影響されることはなく種々の有機溶剤が用いられ得る。むしろ有機溶剤は使用するモノマーの溶解性などに応じて選定すればよく、ポリアミド酸に対して高い溶解性を有する高極性溶剤を用いることが好ましいが、これらの高極性溶剤に貧溶剤を添加することも可能である。高極性溶剤の例としては、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド等のアミド類、Ｎ−メチル−２−ピロリドン等のピロリドン類、フェノール、ｐ−クロロフェノール、ｏ−クロロフェノール等のフェノール類等が挙げられる。貧溶剤の例としては、トルエン、テトラヒドロフラン、アセトン、メチルエチルケトン、メタノール、エタノール等が挙げられる。これらの溶剤を混合して、適当に溶解度パラメータを調整することにより、溶解性を高めることもできる。
【００３９】
上記酸二無水物及びジアミンの添加量は、上記ｐ−フェニレンビス（トリメリット酸モノエステル無水物）が、全酸二無水物に対して０より多く９０モル％以下の範囲、好ましくは１〜９０モル％であり、オキシジフタル酸二無水物が、全酸二無水物に対して１０以上１００モル％未満、好ましくは、１０〜９９モル％であり、ｐ−フェニレンジアミンが、全ジアミンに対して２５〜９０モル％であり、４，４´−ジアミノジフェニルエーテルが、全ジアミンに対して１０〜７５モル％である。
【００４０】
ポリアミド酸の合成のための各モノマーの添加順序は、製造されるポリイミドフィルムの３００℃以上４００℃以下の温度における２００ＭＰａ以上という高い貯蔵弾性率を有する限りにおいては、特に限定されず、様々な方法が可能である。溶剤に、全ジアミンを溶解し、これにテトラカルボン酸二無水物を徐々に加えておおむね当量として粘度を調整しつつ、さらに残りのテトラカルボン酸二無水物をそのままあるいは適当な溶剤に溶解して加えて、当量比を等しくさせることが一般的に行われているが、これに限定されない。
【００４１】
これらの添加順序によっては、フィルムの特性を微妙に制御することも可能である。
【００４２】
具体的には、ＯＤＡとＰＤＡを溶剤中に溶解し、これに対して、ＴＭＨＱを加え、その後ＯＤＰＡを加える方法、あるいは同様に２種のジアミンを溶剤に溶解しておき、これに対して、ＯＤＰＡ、ＴＭＨＱの順に酸二水物を順次加える方法、または同様に２種のジアミンを溶解しておき、これに２種の酸二無水物の混合物を加える方法、２種のジアミンのうちどちらか一方を溶剤に溶解しておき、これに２種の酸二無水物から選択される１種を加えて、その後にもう１種のジアミンを加えさらにその後もう１種の酸二無水物を加える方法、等を挙げることができる。
【００４３】
１種のジアミンを複数のステップに分けて添加すると、さらにバリエーションは多くなり、これらにより種々の特性のさらなる微妙な調整が可能である。特に、ＯＤＡを有機溶剤中に溶解させ、該有機溶剤溶液にＴＭＨＱを加え、続いてＰＤＡを加え、続いてＯＤＰＡを加えて得られたポリアミド酸重合体を、酸無水物と第三級アミンとを用いて脱水閉環し、ポリイミドフィルムを得る方法は、製造されるポリイミドフィルムの３００℃以上４００℃以下の温度における２００ＭＰａ以上という高い貯蔵弾性率を有することにつながり、好ましい。
【００４４】
また、特に、ｐ−フェニレンジアミンを有機溶剤中に溶解させ、続いてオキシジフタル酸二無水物を加えて該有機溶剤溶液に４，４´−ジアミノジフェニルエーテルを加え、続いて、ｐ−フェニレンビス（トリメリット酸モノエステル無水物）を加え、続いてオキシジフタル酸二無水物を加えて、得られたポリアミド酸重合体を、酸無水物と第三級アミンとを用いて脱水閉環し、ポリイミドフィルムを得る方法は、製造されるポリイミドフィルムの３００℃以上４００℃以下の温度における２００ＭＰａ以上という高い貯蔵弾性率を有することにつながり、好ましい。
【００４５】
何れの場合もジアミン化合物のモル量の合計と酸二無水物化合物のモル量の合計は、ほぼ同一となるように用いる。
【００４６】
ここで、「ほぼ同一」としたのは、完全に同一であると重合度が過度に上がりすぎ、その結果溶液粘度が過度に上昇して取り扱いにくくなるからである。具体的には、ジアミン化合物モル量合計と、酸二無水物化合物モル量合計の比率は、０．９５〜１．０５、好ましくは０．９８〜１．０２の範囲であり、１：１でないことが特に好ましい。
【００４７】
それぞれのモノマーの添加割合は、特に限定されないが、好ましくは全酸二無水物中、ＴＭＨＱは、０モル％より多く９０モル％以下であり、ＯＤＰＡは、１０モル％以上１００モル％未満であり、全ジアミン中、ＰＤＡは、２５モル％以上９０モル％以下であり、ＯＤＡは、１０モル％以上７５モル％以下である。
【００４８】
特に好ましくは、全酸二無水物中、ＴＭＨＱは、１モル％以上９０モル％以下であり、ＯＤＰＡは、１０モル％以上９９モル％以下である。
【００４９】
最も好ましくは、全酸二無水物中、ＴＭＨＱは、１モル％以上５０モル％以下であり、ＯＤＰＡは、５０モル％以上９９モル％以下であり、全ジアミン中、ＰＤＡは、５０モル％以上９０モル％以下であり、ＯＤＡは、１０モル％以上５０モル％以下である。
【００５０】
これら４種のモノマー以外のジアミンのモノマー成分を少量加え、すなわちジアミンの場合はジアミン全体の１０モル％以下、酸二無水物の場合は酸二無水物全体の１５モル％以下の量を加え、得られるポリイミドフィルムの特性の微妙な調整をすることも可能である。使用するモノマーにもよるが、概ねこの量以下の共重合であれば、吸湿特性・熱特性・機械特性を好ましいレベルに保つことができる。少量用いるモノマーとしては、ジアミンとしては、ジメチルベンジジン、２、２´−ビス（４−アミノフェノキシフェニル）プロパン、４，４´−ビス（４−アミノフェノキシ）ビフェニル、またこれらのフッ素等ハロゲン置換体等があげられる。酸無水物としては、３，３´，４，４´−ビフェニルテトラカルボン酸二無水物、３，３´，４，４´−ベンゾフェノンテトラカルボン酸二無水物、ピロメリット酸二無水物、３，３´，４，４´−ジフェニルスルフォンテトラカルボン酸二無水物、等を例示することができる。
【００５１】
重合反応は、一般的にポリアミド酸の重合反応に用いられる温度であれば、特に限定されないが、６０℃以下が好ましく、４０℃以下で行うことがより好ましい。高温度になると、酸無水物基の開環反応が生じ易く、ポリアミド酸の生成反応を阻害することがある。
【００５２】
重合反応は、窒素あるいはアルゴン等の不活性ガス中で行わせることが好ましいが、その他の条件下でも行い得る。
【００５３】
ポリアミド酸の溶液中の濃度は、５〜３０ｗｔ％、さらには１０〜２５ｗｔ％が好ましい。これより低いと溶剤が増え、フィルム製造後の乾燥に時間がかかり、これより高い濃度の場合、粘度が上昇して加工が困難となる場合がある。
【００５４】
ポリアミド酸溶液の粘度は、フィルム加工できる粘度であれば特に限定されないが、２２℃で約１００〜１００００ポイズ程度、好ましくは、５００〜６０００ポイズである。粘度が低過ぎるとフィルムの特性に悪影響を与え、加工の際に厚みを安定化することも難しい。一方、粘度が高過ぎる場合、溶液の攪拌が困難となり、フィルム状に加工する際に強い力が必要となり、不都合である。
【００５５】
得られたポリアミド酸の溶液を、フィルム状に形成し、ポリアミド酸をイミド化してポリイミドフィルムを得ることができる。一般的には、このイミド化は、加熱により脱水する熱的方法および脱水剤あるいはイミド化触媒を用いる化学的方法とがある。このうちのいずれの方法を用いてもよく、化学的方法と熱的方法を併用することもできる。脱水剤と触媒を添加して加熱、乾燥する化学的方法によれば、熱的方法よりも効率がよく、優れた特性がフィルムに付与され得る。脱水剤あるいはイミド化触媒を用いない場合でも、本願発明の４種のモノマーを用いるならば製造工程で延伸工程を入れる等の方法により、同等の特性を実現することも可能であるが、生産性の面から、化学的方法が好ましい。
【００５６】
本発明に用いられる脱水剤は、例えば、無水酢酸等の脂肪族酸無水物、芳香族酸無水物などである。また、イミド化に用いられる触媒は、ピリジン、α−ピコリン、β−ピコリン、γ−ピコリン、トリメチルアミン、ジメチルアニリン、トリエチルアミン、イソキノリンなどの第３級アミンなどである。
【００５７】
例えば、以下にイミド化の化学的方法の例を挙げるが、本発明はこれに限定されない。すなわち、得られたポリアミド酸溶液に化学量論以上の脱水剤と触媒量の第３級アミンとを加えた溶液を、支持板やＰＥＴ等の有機化合物製のフィルム、ドラム、あるいはエンドレスベルト状に流延又は塗布して膜状とし、その膜を１５０℃以下の温度で約５分〜９０分間乾燥し、自己支持性のポリアミド酸重合体の塗膜を得る。次にこれを支持体より引き剥がして端部を固定する。その後、１００℃〜５００℃程度まで徐々に加熱することによりイミド化させ、冷却後これより取り外してポリイミドフィルムを得る。
【００５８】
熱的方法によるイミド化の例は、上記の化学的イミド化法と同様の工程が挙げられるが、これに限定されない。すなわち、ポリアミド酸溶液を支持板やＰＥＴ等の有機化合物製のフィルム、ドラムあるいはエンドレスベルト等の支持体上に流延または塗布して膜状とし、加熱処理し得る。
【００５９】
フィルムの製造に際しては、さらに、熱劣化防止剤を加えて焼成時のフィルムの劣化を防止し得る。その他の添加剤を加えて、フィルム製造時におけるフィルムの劣化等を防止することもできる。熱劣化防止剤としては、トリフェニルフォスフェイト等のリン酸系の劣化防止剤、置換基を有する又は置換基を有さないベンゾフェノン等が挙げられる。その他の添加剤としては、金属単体、有機金属化合物、またはガラス系のフィラー類等が挙げられる。
【００６０】
上記のようにして製造される本発明にかかるポリイミドフィルムは、高貯蔵弾性率を有しつつ、高弾性率、高破断時伸び率、低線膨張係数、低吸湿膨張係数、一定の耐熱性、接着性等それぞれの特性を有するバランスのよいポリイミドフィルムである。
【００６１】
具体的には、本発明にかかるポリイミドフィルムは、３００℃以上４００℃以下の温度における貯蔵弾性率が２００ＭＰａ以上である。また、１００℃以上２００℃以下の平均線膨張係数が１５〜３０ｐｐｍ、引張弾性率が４．５〜８．５ＧＰａ、破断時伸び率が２０％以上、吸湿膨張係数が１０ｐｐｍ以下、Ｔｇが２００℃以上である特性を顕現することができる。
【００６２】
ここで、本発明にかかるポリイミドフィルムの特性は、以下のように測定したものである。すなわち、３００℃以上４００℃以下の温度における貯蔵弾性率およびガラス転移温度（Ｔｇ）は、動的粘弾性測定装置（セイコー電子工業株式会社製ＤＭＳ２００）を用いて引張モードで、３℃／分の割合で昇温させながら測定する。引張弾性率及び破断時伸び率とは、それぞれＡＳＴＭ−Ｄ８８２に準じた測定値をいう。平均線膨脹係数は、セイコー電子工業株式会社製ＴＭＡ１２０Ｃを用いて、窒素の存在下、１分間に１０℃の割合で温度を上昇させて、１００℃〜２００℃の時の値を測定して求める。吸湿膨脹係数は、ポリイミドフィルムがたるまないように最低限の加重をかけた状態（５ｍｍ×２０ｍｍのサンプルに対して、約３ｇ）で、湿度を３０ＲＨ％に調湿し完全に飽和するまで吸湿させて寸法を計測し、その後湿度を９０ＲＨ％に調湿し同様に飽和吸湿させた後寸法を計測し、両者の結果から相対湿度差１％あたりの寸法変化率を求める。
【００６３】
【実施例】
以下に実施例により本発明をより具体的に説明するが、本発明はこれら実施例によって限定されるものではない。
【００６４】
（実施例１）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２８．８ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、３５．１ｇ（総酸二無水物中の約２０ｍｏｌ％）のＴＭＨＱを溶解し、２５．９ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、これにＯＤＰＡ９５．２ｇ（総酸二無水物中の約８０ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００６５】
このポリアミド酸溶液１００ｇを０℃程度に冷却し、これに１２．９ｇの無水酢酸と４．０ｇのイソキノリンを加えて、均一に攪拌しこれを、ＳＵＳ板上に焼成後５０μmになるような所定の厚みにキャストし、１２５℃で５分熱風乾燥した。その後ＳＵＳ板よりフィルムを引き剥がし、これを端部を固定した状態で１７０℃で１．５分、２５０℃で１．５分、３５０℃で３分、４３０℃で３分加熱乾燥し、ポリイミドフィルムを得た。この製膜中に、フィルムがたるむことは無かった。このフィルムの引張弾性率、破断時伸び率、線膨張係数、吸湿膨張係数、Ｔｇ、３５０℃での貯蔵弾性率を測定した結果を表１に示す。
【００６６】
（実施例２）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２８．６ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、３８．６ｇ（総酸二無水物中の約２２．１ｍｏｌ％）のＴＭＨＱを溶解し、２５．７ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、これにＯＤＰＡ９２．１ｇ（総酸二無水物中の約７７．９ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００６７】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表１に示す。
【００６８】
（実施例３）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド７８０ｇ中に、３３．１ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、６２．７ｇ（総酸二無水物中の約３１ｍｏｌ％）のＴＭＨＱを溶解し、２９．８ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、これにＯＤＰＡ９４．４ｇ（総酸二無水物中の約６９ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００６９】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表１に示す。
【００７０】
（実施例４）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、３１．５ｇ（総ジアミン中の約４２．９ｍｏｌ％）のＯＤＡを溶解し、５２．２ｇ（総酸二無水物中の約３１ｍｏｌ％）のＴＭＨＱを溶解し、２２．７ｇ（総ジアミン中の約５７．１ｍｏｌ％）のＰＤＡを溶解し、これにＯＤＰＡ７８．６ｇ（総酸二無水物中の約６９ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００７１】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表１に示す。
【００７２】
【表１】

【００７３】
（実施例５）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２７．５ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、７７．６ｇ（総酸二無水物中の約６１．５ｍｏｌ％）のＯＤＰＡを溶解し、３０．５ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、これにＯＤＰＡ４６．７ｇ（総酸二無水物中の約３７ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、続いてＴＭＨＱ２．８ｇ（総酸二無水物中の約１．５ｍｏｌ％）を徐々に加え、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００７４】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表２に示す。
【００７５】
（実施例６）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２５．１ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、７０．８ｇ（総酸二無水物中の約６１．５ｍｏｌ％）のＯＤＰＡを溶解し、２７．８ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、これにＯＤＰＡ８．６ｇ（総酸二無水物中の約７．５ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、続いてＴＭＨＱ５２．７ｇ（総酸二無水物中の約３１ｍｏｌ％）を徐々に加え、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００７６】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表２に示す。
【００７７】
（実施例７）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２１．３ｇ（総ジアミン中の約５３．９ｍｏｌ％）のＰＤＡを溶解し、５９．９ｇ（総酸二無水物中の約５２．９ｍｏｌ％）のＯＤＰＡを溶解し、３３．７ｇ（総ジアミン中の約４６．１ｍｏｌ％）のＯＤＡを溶解し、これにＯＤＰＡ１８．２ｇ（総酸二無水物中の約１６．１ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、続いてＴＭＨＱ５１．９ｇ（総酸二無水物中の約３１ｍｏｌ％）を徐々に加え、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００７８】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表２に示す。
【００７９】
【表２】

【００８０】
（実施例８）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２５．７ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、７２．７ｇ（総酸二無水物中の約６１．５ｍｏｌ％）のＯＤＰＡを溶解し、２８．６ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、これにＴＭＨＱ３８．６ｇ（総酸二無水物中の約２２．１ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、続いてＯＤＰＡ１９．４ｇ（総酸二無水物中の約１６．４ｍｏｌ％）を徐々に加え、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００８１】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表３に示す。
【００８２】
（実施例９）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２５．７ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、６４．８ｇ（総酸二無水物中の約５４．８ｍｏｌ％）のＯＤＰＡを溶解し、２８．６ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、これにＴＭＨＱ３８．６ｇ（総酸二無水物中の約２２．１ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、続いてＯＤＰＡ２７．３ｇ（総酸二無水物中の約２３．１ｍｏｌ％）を徐々に加え、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００８３】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表３に示す。
【００８４】
（実施例１０）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２５．７ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、５８．７ｇ（総酸二無水物中の約４９．７ｍｏｌ％）のＯＤＰＡを溶解し、２８．６ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、これにＴＭＨＱ３８．６ｇ（総酸二無水物中の約２２．１ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、続いてＯＤＰＡ３３．３ｇ（総酸二無水物中の約２８．２ｍｏｌ％）を徐々に加え、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００８５】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表３に示す。
【００８６】
（実施例１１）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド８１５ｇ中に、２５．７ｇ（総ジアミン中の約６２．５ｍｏｌ％）のＰＤＡを溶解し、５５．７ｇ（総酸二無水物中の約４７．１ｍｏｌ％）のＯＤＰＡを溶解し、２８．６ｇ（総ジアミン中の約３７．５ｍｏｌ％）のＯＤＡを溶解し、これにＴＭＨＱ３８．６ｇ（総酸二無水物中の約２２．１ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、続いてＯＤＰＡ３６．４ｇ（総酸二無水物中の約３０．８ｍｏｌ％）を徐々に加え、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
【００８７】
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるむことは無かった。実施例１と同様に、特性試験を行った。その結果を表３に示す。
【００８８】
【表３】

【００８９】
（比較例１）
窒素置換雰囲気中の氷浴下でジメチルアセトアミド６２４ｇ中に、ＰＤＡ２３．８ｇ（総ジアミン中の約６２．５ｍｏｌ％）およびＯＤＡ２６．５ｇ（総ジアミン中の約３７．５ｍｏｌ％）を溶解し、
これにＴＭＨＱ５０．１ｇ（総酸二無水物中の約３１ｍｏｌ％）を徐々に加えて良く攪拌し反応させ、続いてＯＤＰＡ７５．５ｇ（総酸二無水物中の約６９ｍｏｌ％）を徐々に加え、２３℃での測定で約２５００ポイズのポリアミド酸溶液を得た。
このポリアミド酸溶液を実施例１と同様の方法で加工し、ポリイミドフィルムとした。この製膜中に、フィルムがたるんだ。結果、平坦なフィルムを作製することは困難であったが、若干平坦な部分を使用して、実施例１と同様に、特性試験を行った。その結果を表４に示す。
【００９０】
【表４】

【００９１】
【発明の効果】
本発明のポリイミドフィルムはこれまでのベース用ポリイミドフィルムに無い優れた吸湿特性、特に低い吸湿膨張を有し、なおかつ高弾性、高貯蔵弾性率でありながら銅の線膨張係数を下回ることなく、従って銅張の基板やＴＡＢ用テープとして用いた場合に極めて優れた反り特性を発現できる。本発明のポリイミドフィルムは、柔軟性・耐熱性にも優れ、ベースポリイミドフィルムとして必要な特性を損なわないため、益々細密化する電子機器に対応することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polyimide film excellent in balance of physical properties, which can give low warpage and high dimensional stability in a product bonded with metal, particularly copper.
[0002]
[Prior art]
The polyimide film has heat resistance, insulation, solvent resistance, low temperature resistance, and the like, and is widely used as a material for computer and IC control electric / electronic equipment parts.
[0003]
In recent years, with the miniaturization and thinning of computers and IC-controlled electric and electronic devices, wiring boards and IC package materials are also required to be small and thin. For this reason, the wiring pattern given to these also becomes fine, and it is necessary for the polyimide film used for a flexible wiring board, a TAB carrier tape, etc. to have a small dimensional change by heating, tension, and moisture absorption. Furthermore, as the material becomes thinner, it is necessary to keep the “strain” of the entire laminate and to stabilize the processing process.
[0004]
In order to satisfy such a need, the polyimide film is desired to have a low linear expansion coefficient, a high elastic modulus and a storage elastic modulus, and a low hygroscopic expansion coefficient.
[0005]
However, since the polyimide film and the copper foil are bonded and processed when manufacturing the flexible wiring board or the IC package, it is not preferable that the film linear expansion coefficient is greatly different from that of copper. That is, if the linear expansion coefficients of the polyimide film and the copper foil are greatly different, the bonded product is warped and difficult to process, and as a result, the overall dimensional accuracy and yield are lowered. Therefore, the thing with a small difference of a linear expansion coefficient with copper foil is preferable.
[0006]
Various attempts have been made to obtain a polyimide film having the above characteristics. First, it is widely known that a monomer having a rigid structure, that is, a monomer having high linearity, may be used to increase the elastic modulus of a polyimide film. However, if a large amount of highly linear monomer is used, the linear expansion coefficient of the film becomes too low and it is not suitable for use in bonding with a copper foil.
[0007]
In order not to reduce the linear expansion coefficient too much while achieving a relatively high elastic modulus, a monomer having a relatively rigid structure is produced by a thermal curing method without using a chemical imidizing agent. There is also an example that takes a method of sweetening the orientation. However, the thermal curing method has the disadvantage that the required heating time is longer than that of the chemical curing method and the productivity is inferior.
[0008]
Further, when a monomer having rigidity and high linearity is used, the flexibility of the film is generally impaired, and there is a possibility that it may be difficult to bend, which is one of the advantages as a flexible wiring board. .
[0009]
In semiconductor package applications and the like, in particular, the water absorption rate is required to be as low as possible from the viewpoint of semiconductor reliability, and the hygroscopic expansion coefficient is also required to be low from the viewpoint of dimensional stability.
[0010]
In order to reduce the water absorption rate and the hygroscopic expansion coefficient, it is effective to reduce the amount of imide groups in the molecular structure. For this reason, a long-chain monomer containing a plurality of bending groups in the main chain is often used. However, this results in a decrease in elastic modulus and an excessive increase in linear expansion coefficient, and sacrifices dimensional stability. In an extreme case, for example, a thermoplastic resin having Tg at a low temperature of 200 ° C. or lower is exhibited, and is not suitable for use as a base film. In addition, when such a long monomer with linearity is used, there is a problem that packing of molecular chains becomes difficult, sufficient toughness cannot be expressed, and in some cases, it is difficult to form a film itself. It was.
[0011]
In general, the value of the storage elastic modulus of a viscoelastic body (including a polyimide film) is lower than the value of the storage elastic modulus at room temperature in the temperature range exceeding Tg (one digit, depending on the case, 2 to 3 in some cases). When the storage elastic modulus at the temperature normally used for film production (for example, 300 ° C. or more and 400 ° C. or less) is extremely small, the film sags extremely in the temperature range of film production. For example, it may be difficult to produce a flat film without sagging.
[0012]
As described above, in order to realize all of the properties required for polyimide film, such as high elastic modulus, high storage elastic modulus, low linear expansion coefficient, and low water absorption, in addition to these properties, film processability There are many points that should be taken into consideration, and there are problems such as sacrificing other properties when trying to satisfy one of the properties, and it is particularly difficult to obtain a polyimide film that has all of the good properties. there were.
[0013]
[Problems to be solved by the invention]
Therefore, the present inventors have solved the above problems and have all the characteristics of high elastic modulus, high storage elastic modulus, linear expansion coefficient close to copper, sufficient toughness, low water absorption, and low hygroscopic expansion coefficient. As a result of intensive investigations on producing a polyimide film suitable for a flexible printed circuit board and a TAB film with fine wiring, the present invention has been achieved.
[0014]
[Means for Solving the Problems]
In view of the above-mentioned demands, the present inventors have found a polyimide film capable of specifically realizing and controlling various property balances in a polyimide film having a specific composition and a method for producing the same.
[0015]
The gist of the polyimide film according to the present invention is that p-phenylenebis (trimellitic acid monoester anhydride), oxydiphthalic dianhydride, p-phenylenediamine, and 4,4′-diaminodiphenyl ether. A polyimide film characterized by being produced from a polyamic acid obtained by reacting four kinds of monomers, wherein the storage elastic modulus at a temperature of 300 ° C. to 400 ° C. is 200 MPa or more. The content is a polyimide film.
[0016]
In the polyimide film, the p-phenylenebis (trimellitic acid monoester anhydride) is 1 to 90 mol% based on the total acid dianhydride, and the oxydiphthalic acid dianhydride is converted into the total acid dianhydride. 10-99 mol%, p-phenylenediamine is 25-90 mol% with respect to the total diamine, and 4,4'-diaminodiphenyl ether is 10-75 mol% with respect to the total diamine. The content.
[0017]
In such a polyimide film, the average linear expansion coefficient between 100 ° C. and 200 ° C. is 15 to 30 ppm, the tensile elastic modulus is 4.5 to 8.5 GPa, the elongation at break is 20% or more, the hygroscopic expansion coefficient is 10 ppm or less, The content is that Tg is 200 ° C. or higher.
[0018]
The gist of the production method of the polyimide film according to the present invention is that 4,4′-diaminodiphenyl ether is dissolved in an organic solvent, and p-phenylenebis (trimellitic acid monoester anhydride) is dissolved in the organic solvent solution. Followed by addition of p-phenylenediamine, followed by addition of oxydiphthalic dianhydride, polyamic acid polymer obtained by dehydration ring closure using acid anhydride and tertiary amine, The content is to obtain.
[0019]
Another aspect of the production method of the polyimide film according to the present invention is that p-phenylenediamine is dissolved in an organic solvent, and then oxydiphthalic dianhydride is added to the organic solvent solution to add 4,4 ′. -Diaminodiphenyl ether was added, followed by oxydiphthalic dianhydride, followed by addition of p-phenylenebis (trimellitic acid monoester anhydride). It is intended to obtain a polyimide film by dehydrating and ring-closing using a tertiary amine.
[0020]
Another aspect of the production method of the polyimide film according to the present invention is that p-phenylenediamine is dissolved in an organic solvent, and then oxydiphthalic dianhydride is added to the organic solvent solution to add 4,4 ′. -Diaminodiphenyl ether is added, followed by p-phenylenebis (trimellitic acid monoester anhydride), followed by oxydiphthalic dianhydride, and the resulting polyamic acid polymer is treated with acid anhydride. It is intended to obtain a polyimide film by dehydrating and ring-closing using a tertiary amine.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the polyimide film concerning this invention is demonstrated based on one example of the embodiment. The term “monomer” in the present invention refers to either monomeric diamine or tetracarboxylic dianhydride.
[0022]
The polyimide film concerning this invention can be manufactured from the polyamic acid prepared by the polyamic acid synthesis method well-known to those skilled in the art. Preferably, in the method for producing a polyimide film of the present invention, the dehydration ring closure can be performed in the presence of an imidizing agent of an acid anhydride and a tertiary amine.
[0023]
In the present invention, in order to synthesize a polyamic acid, as an acid dianhydride, in particular, p-phenylenebis (trimellitic acid monoester anhydride) (hereinafter referred to as TMHQ) having the following structural formula:
[0024]
[Chemical 1]

[0025]
And oxydiphthalic dianhydride (hereinafter referred to as ODPA) having the following structural formula
[0026]
[Chemical 2]

[0027]
As a diamine, p-phenylenediamine (hereinafter referred to as PDA) having the following structural formula
[0028]
[Chemical 3]

[0029]
And 4,4′-diaminodiphenyl ether (hereinafter referred to as ODA) having the following structural formula
[0030]
[Formula 4]

[0031]
Is used. The above monomer is dissolved in an organic solvent and polymerized to obtain a polyamic acid that can be used to produce the polyimide film according to the present invention.
[0032]
Hereinafter, TMHQ has a rod-like structure in combination with PDA, reveals high elasticity of the film, and is somewhat flexible due to ester bond on the main chain structure. For example, only pyromellitic acid was used. Compared to the case, the linear expansion coefficient does not extremely decrease. The ester bond also has the effect of relaxing the polarization of the imide ring, lowering the water absorption rate and lowering the water absorption expansion rate.
[0033]
However, TMHQ, when combined with PDA, is structurally too hard, the coefficient of linear expansion is still low, and the toughness is insufficient. Even when diaminodiphenyl ether is copolymerized, the coefficient of linear expansion is too low and the toughness is insufficient if an elastic modulus of a certain level or more is still desired.
[0034]
Using ODPA, PDA and diaminodiphenyl ether can be polymerized to achieve an appropriate coefficient of linear expansion, sufficient toughness, etc. that is not inconvenient in a combination of an appropriately high elastic modulus and copper. However, the ODPA alone does not reduce the water absorption rate so much, and the configuration of the present invention, in which TMHQ is further copolymerized, is very effective in order to lower the moisture absorption characteristics and keep various characteristics favorable.
[0035]
Furthermore, the configuration of the present invention having a high storage elastic modulus of 200 MPa or higher at a temperature of 300 ° C. or higher and 400 ° C. or lower while maintaining other desirable characteristics that can be realized by a combination of ODPA and TMHQ is very effective. .
[0036]
The constitution of the present invention for producing a polyimide film having a high storage elastic modulus of 200 MPa or more at a temperature of 300 ° C. or more and 400 ° C. or less by the monomer charging sequence of the present invention is very effective.
[0037]
In order to stably produce a film without sagging during film production, the storage elastic modulus at a temperature of 300 ° C. or higher and 400 ° C. or lower has a high storage elasticity of 200 MPa or higher, preferably 400 Ma or higher, more preferably 600 MPa or higher. It is preferable to have a rate. When the storage elastic modulus at a temperature of 300 ° C. or more and 400 ° C. or less is 200 MPa or less, there is a possibility that the film may sag depending on the film production conditions, which is not preferable.
[0038]
Various organic solvents can be used for the polymerization of the polyamic acid, but the effects of the present invention are not greatly affected by the type of organic solvent used, and various organic solvents can be used. Rather, the organic solvent may be selected according to the solubility of the monomer used, and it is preferable to use a highly polar solvent having high solubility with respect to polyamic acid, but a poor solvent is added to these highly polar solvents. It is also possible. Examples of highly polar solvents include amides such as N, N-dimethylformamide, N, N-dimethylacetamide, pyrrolidones such as N-methyl-2-pyrrolidone, phenol, p-chlorophenol, o-chlorophenol, etc. Phenols and the like. Examples of the poor solvent include toluene, tetrahydrofuran, acetone, methyl ethyl ketone, methanol, ethanol and the like. The solubility can also be improved by mixing these solvents and adjusting the solubility parameter appropriately.
[0039]
The amount of the acid dianhydride and diamine added is such that the p-phenylenebis (trimellitic acid monoester anhydride) is more than 0 and not more than 90 mol%, preferably 1 to 90 mol%, oxydiphthalic dianhydride is 10 or more and less than 100 mol%, preferably 10 to 99 mol%, based on the total acid dianhydride, and p-phenylenediamine is based on the total diamine. It is 25-90 mol%, and 4,4'- diaminodiphenyl ether is 10-75 mol% with respect to all the diamines.
[0040]
The order of addition of each monomer for the synthesis of polyamic acid is not particularly limited as long as it has a high storage elastic modulus of 200 MPa or more at a temperature of 300 ° C. or more and 400 ° C. or less of the polyimide film to be produced. Is possible. Dissolve all diamines in a solvent and gradually add tetracarboxylic dianhydride to this to adjust the viscosity to an equivalent, while further dissolving the remaining tetracarboxylic dianhydride as it is or in an appropriate solvent. In addition, the equivalent ratio is generally equalized, but is not limited thereto.
[0041]
Depending on the order of addition, the film characteristics can be finely controlled.
[0042]
Specifically, ODA and PDA are dissolved in a solvent, TMHQ is added thereto, and then ODPA is added, or two diamines are similarly dissolved in a solvent. A method in which acid dihydrate is sequentially added in the order of ODPA and TMHQ, or a method in which two types of diamine are dissolved in the same manner, and a mixture of two types of acid dianhydrides is added thereto. A method in which one is dissolved in a solvent, one selected from two types of acid dianhydrides is added thereto, another diamine is added thereafter, and then another acid dianhydride is added. , Etc.
[0043]
When one kind of diamine is added in a plurality of steps, variations are further increased, and these allow further fine adjustment of various properties. In particular, the polyamic acid polymer obtained by dissolving ODA in an organic solvent, adding TMHQ to the organic solvent solution, followed by adding PDA, and then adding ODPA, is obtained with an acid anhydride and a tertiary amine. The method of obtaining a polyimide film by dehydrating and ring-closing using a tantalum is preferable because it has a high storage elastic modulus of 200 MPa or more at a temperature of 300 ° C. or more and 400 ° C. or less of the produced polyimide film.
[0044]
In particular, p-phenylenediamine is dissolved in an organic solvent, oxydiphthalic dianhydride is subsequently added, and 4,4′-diaminodiphenyl ether is added to the organic solvent solution, followed by p-phenylenebis (tri Mellitic acid monoester anhydride) is added, followed by oxydiphthalic dianhydride, and the resulting polyamic acid polymer is dehydrated and cyclized using acid anhydride and tertiary amine to obtain a polyimide film. The method is preferable because it leads to having a high storage elastic modulus of 200 MPa or more at a temperature of 300 ° C. or more and 400 ° C. or less of the polyimide film to be produced.
[0045]
In any case, the total molar amount of the diamine compound and the total molar amount of the acid dianhydride compound are used to be substantially the same.
[0046]
Here, “substantially the same” is because, when they are completely the same, the degree of polymerization is excessively increased, and as a result, the viscosity of the solution is excessively increased and is difficult to handle. Specifically, the ratio of the total molar amount of the diamine compound to the total molar amount of the acid dianhydride compound is in the range of 0.95 to 1.05, preferably 0.98 to 1.02, and is not 1: 1. It is particularly preferred.
[0047]
The addition ratio of each monomer is not particularly limited, but preferably TMHQ is more than 0 mol% and 90 mol% or less, and ODPA is 10 mol% or more and less than 100 mol% in all acid dianhydrides. In all diamines, PDA is 25 mol% or more and 90 mol% or less, and ODA is 10 mol% or more and 75 mol% or less.
[0048]
Particularly preferably, TMHQ in the total acid dianhydride is 1 mol% or more and 90 mol% or less, and ODPA is 10 mol% or more and 99 mol% or less.
[0049]
Most preferably, TMHQ is 1 mol% or more and 50 mol% or less in total acid dianhydride, ODPA is 50 mol% or more and 99 mol% or less, and PDA is 50 mol% or more in all diamines. It is 90 mol% or less, and ODA is 10 mol% or more and 50 mol% or less.
[0050]
Add a small amount of monomer components of diamine other than these four monomers, that is, in the case of diamine, add 10 mol% or less of the whole diamine, in the case of acid dianhydride, add 15 mol% or less of the whole acid dianhydride, It is also possible to finely adjust the characteristics of the obtained polyimide film. Although depending on the monomer used, if the amount of copolymerization is generally less than this amount, moisture absorption characteristics, thermal characteristics, and mechanical characteristics can be maintained at favorable levels. As a monomer to be used in a small amount, as diamine, dimethylbenzidine, 2,2′-bis (4-aminophenoxyphenyl) propane, 4,4′-bis (4-aminophenoxy) biphenyl, and halogen-substituted products thereof such as fluorine Etc. Examples of the acid anhydride include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, pyromellitic dianhydride, 3 , 3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, and the like.
[0051]
Although it will not specifically limit if a polymerization reaction is the temperature generally used for the polymerization reaction of a polyamic acid, 60 degrees C or less is preferable and it is more preferable to carry out at 40 degrees C or less. When the temperature is high, the ring opening reaction of the acid anhydride group is likely to occur, and the formation reaction of the polyamic acid may be inhibited.
[0052]
The polymerization reaction is preferably performed in an inert gas such as nitrogen or argon, but may be performed under other conditions.
[0053]
The concentration of the polyamic acid in the solution is preferably 5 to 30 wt%, more preferably 10 to 25 wt%. If it is lower than this, the solvent will increase, and it will take time for drying after film production. If the concentration is higher than this, the viscosity may increase and processing may be difficult.
[0054]
The viscosity of the polyamic acid solution is not particularly limited as long as it can be processed into a film, but is about 100 to 10000 poise at 22 ° C., preferably 500 to 6000 poise. If the viscosity is too low, the film properties are adversely affected, and it is difficult to stabilize the thickness during processing. On the other hand, when the viscosity is too high, stirring of the solution becomes difficult, and a strong force is required when processing into a film, which is inconvenient.
[0055]
The obtained polyamic acid solution can be formed into a film, and the polyamic acid can be imidized to obtain a polyimide film. Generally, this imidation includes a thermal method for dehydration by heating and a chemical method using a dehydrating agent or an imidization catalyst. Any of these methods may be used, and a chemical method and a thermal method may be used in combination. According to a chemical method in which a dehydrating agent and a catalyst are added and heated and dried, the film is more efficient than the thermal method, and excellent properties can be imparted to the film. Even when no dehydrating agent or imidization catalyst is used, if the four types of monomers of the present invention are used, it is possible to achieve equivalent characteristics by a method such as inserting a stretching step in the production process, but productivity From this aspect, a chemical method is preferable.
[0056]
Examples of the dehydrating agent used in the present invention include aliphatic acid anhydrides such as acetic anhydride, aromatic acid anhydrides, and the like. Examples of the catalyst used for imidization include tertiary amines such as pyridine, α-picoline, β-picoline, γ-picoline, trimethylamine, dimethylaniline, triethylamine, and isoquinoline.
[0057]
For example, although the example of the chemical method of imidation is given to the following, this invention is not limited to this. That is, a solution obtained by adding a stoichiometric or higher amount of a dehydrating agent and a catalytic amount of a tertiary amine to the obtained polyamic acid solution is formed into a film made of an organic compound such as a support plate or PET, a drum, or an endless belt. The film is cast or applied to form a film, and the film is dried at a temperature of 150 ° C. or less for about 5 minutes to 90 minutes to obtain a self-supporting polyamic acid polymer coating film. Next, this is peeled off from a support body and an edge part is fixed. Then, it is made to imidize by gradually heating to about 100 degreeC-about 500 degreeC, and it removes from this after cooling and obtains a polyimide film.
[0058]
Examples of imidization by a thermal method include the same steps as the chemical imidation method described above, but are not limited thereto. That is, the polyamic acid solution may be cast or coated on a support plate, a film made of an organic compound such as PET, a support such as a drum or an endless belt to form a film, and heat-treated.
[0059]
In the production of the film, a heat deterioration inhibitor may be added to prevent the film from being deteriorated during firing. Other additives may be added to prevent film deterioration during film production. Examples of the thermal degradation inhibitor include phosphoric acid degradation inhibitors such as triphenyl phosphate, benzophenone having a substituent or not having a substituent. Examples of other additives include simple metals, organometallic compounds, and glass fillers.
[0060]
The polyimide film according to the present invention manufactured as described above has a high storage elastic modulus, a high elastic modulus, a high elongation at break, a low linear expansion coefficient, a low hygroscopic expansion coefficient, a certain heat resistance, It is a well-balanced polyimide film having various properties such as adhesiveness.
[0061]
Specifically, the polyimide film according to the present invention has a storage elastic modulus of 200 MPa or more at a temperature of 300 ° C. or more and 400 ° C. or less. Further, the average linear expansion coefficient of 100 to 200 ° C. is 15 to 30 ppm, the tensile modulus is 4.5 to 8.5 GPa, the elongation at break is 20% or more, the hygroscopic expansion coefficient is 10 ppm or less, and the Tg is 200 ° C. The above characteristics can be manifested.
[0062]
Here, the characteristic of the polyimide film concerning this invention is measured as follows. That is, the storage elastic modulus and glass transition temperature (Tg) at a temperature of 300 ° C. or higher and 400 ° C. or lower are 3 ° C./min in a tensile mode using a dynamic viscoelasticity measuring device (DMS200 manufactured by Seiko Electronics Industry Co., Ltd.). Measure while heating at a rate. A tensile elasticity modulus and elongation at break say the measured value according to ASTM-D882, respectively. The average linear expansion coefficient is obtained by measuring the value at 100 ° C. to 200 ° C. using TMA120C manufactured by Seiko Denshi Kogyo Co., Ltd., increasing the temperature at a rate of 10 ° C. per minute in the presence of nitrogen. . The hygroscopic expansion coefficient was adjusted to a humidity of 30 RH% with the minimum weight applied so that the polyimide film does not sag (about 3 g for a 5 mm x 20 mm sample). Measure the dimensions, and then adjust the humidity to 90 RH% and similarly absorb the saturated moisture, measure the dimensions, and obtain the dimensional change rate per 1% relative humidity difference from the results of both.
[0063]
【Example】
The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.
[0064]
Example 1
28.8 g (about 37.5 mol% in the total diamine) of ODA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen atmosphere, and 35.1 g (about 20 mol% in the total acid dianhydride). TMHQ was dissolved, 25.9 g (about 62.5 mol% in the total diamine) of PDA was dissolved, and 95.2 g of ODPA (about 80 mol% in the total acid dianhydride) was gradually added thereto and stirred well. Then, a polyamic acid solution of about 2500 poise was obtained by measurement at 23 ° C.
[0065]
100 g of this polyamic acid solution is cooled to about 0 ° C., 12.9 g of acetic anhydride and 4.0 g of isoquinoline are added to this, and the mixture is stirred uniformly. And dried with hot air at 125 ° C. for 5 minutes. Thereafter, the film is peeled off from the SUS plate, and with the ends fixed, the film is dried by heating at 170 ° C. for 1.5 minutes, 250 ° C. for 1.5 minutes, 350 ° C. for 3 minutes, and 430 ° C. for 3 minutes. A film was obtained. During the film formation, the film did not sag. Table 1 shows the results of measuring the tensile modulus, elongation at break, linear expansion coefficient, hygroscopic expansion coefficient, Tg, and storage elastic modulus at 350 ° C. of this film.
[0066]
(Example 2)
28.6 g (about 37.5 mol% in total diamine) of ODA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen purge atmosphere, and 38.6 g (about 22.1 mol in total acid dianhydride). %) TMHQ and 25.7 g (about 62.5 mol% in total diamine) of PDA were dissolved, and 92.1 g of ODPA (about 77.9 mol% in total acid dianhydride) was gradually added. In addition, the mixture was well stirred and reacted to obtain a polyamic acid solution having a value of about 2500 poise as measured at 23 ° C.
[0067]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 1.
[0068]
Example 3
33.1 g (about 37.5 mol% in the total diamine) of ODA was dissolved in 780 g of dimethylacetamide under an ice bath in a nitrogen atmosphere, and 62.7 g (about 31 mol% in the total acid dianhydride). TMHQ was dissolved, 29.8 g (about 62.5 mol% in the total diamine) of PDA was dissolved, and 94.4 g of ODPA (about 69 mol% in the total acid dianhydride) was gradually added thereto and stirred well. Then, a polyamic acid solution of about 2500 poise was obtained by measurement at 23 ° C.
[0069]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 1.
[0070]
Example 4
31.5 g (about 42.9 mol% in the total diamine) of ODA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen atmosphere, and 52.2 g (about 31 mol% in the total acid dianhydride). TMHQ was dissolved, 22.7 g (about 57.1 mol% in the total diamine) of PDA was dissolved, and 78.6 g of ODPA (about 69 mol% in the total acid dianhydride) was gradually added thereto and stirred well. Then, a polyamic acid solution of about 2500 poise was obtained by measurement at 23 ° C.
[0071]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 1.
[0072]
[Table 1]

[0073]
(Example 5)
27.5 g (about 62.5 mol% in total diamine) of PDA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen purge atmosphere, and 77.6 g (about 61.5 mol in total acid dianhydride) was dissolved. %) ODPA, 30.5 g (about 37.5 mol% in total diamine) of ODA was dissolved, and 46.7 g ODPA (about 37 mol% in total acid dianhydride) was gradually added thereto. The mixture was stirred and reacted well, and then 2.8 g of TMHQ (about 1.5 mol% in total acid dianhydride) was gradually added to obtain a polyamic acid solution of about 2500 poise as measured at 23 ° C.
[0074]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 2.
[0075]
(Example 6)
25.1 g (about 62.5 mol% in total diamine) of PDA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen purge atmosphere, and 70.8 g (about 61.5 mol in total acid dianhydride) was dissolved. %) Of ODPA, 27.8 g (about 37.5 mol% in the total diamine) of ODA was dissolved, and 8.6 g of ODPA (about 7.5 mol% in the total acid dianhydride) was gradually added thereto. In addition, the mixture was thoroughly stirred and reacted, and then 52.7 g of TMHQ (about 31 mol% in the total acid dianhydride) was gradually added to obtain a polyamic acid solution of about 2500 poise as measured at 23 ° C.
[0076]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 2.
[0077]
(Example 7)
21.3 g (about 53.9 mol% in the total diamine) of PDA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen atmosphere, and 59.9 g (about 52.9 mol in total acid dianhydride). %)), 33.7 g (about 46.1 mol% in total diamine) of ODA was dissolved, and 18.2 g (about 16.1 mol% in total acid dianhydride) was gradually added thereto. In addition, the mixture was well stirred and reacted, and then 51.9 g of TMHQ (about 31 mol% in the total acid dianhydride) was gradually added to obtain a polyamic acid solution of about 2500 poise as measured at 23 ° C.
[0078]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 2.
[0079]
[Table 2]

[0080]
(Example 8)
25.7 g (about 62.5 mol% in total diamine) of PDA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen atmosphere, and 72.7 g (about 61.5 mol in total acid dianhydride). %) ODPA, 28.6 g (about 37.5 mol% in total diamine) of ODA was dissolved, and TMHQ 38.6 g (about 22.1 mol% in total acid dianhydride) was gradually added thereto. In addition, the mixture was thoroughly stirred and reacted, and then 19.4 g of ODPA (about 16.4 mol% in total acid dianhydride) was gradually added to obtain a polyamic acid solution of about 2500 poise as measured at 23 ° C.
[0081]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 3.
[0082]
Example 9
25.7 g (about 62.5 mol% in total diamine) of PDA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen purge atmosphere, and 64.8 g (about 54.8 mol in total acid dianhydride) was dissolved. %) ODPA, 28.6 g (about 37.5 mol% in total diamine) of ODA was dissolved, and TMHQ 38.6 g (about 22.1 mol% in total acid dianhydride) was gradually added thereto. In addition, the mixture was well stirred and reacted, and then 27.3 g of ODPA (about 23.1 mol% in the total acid dianhydride) was gradually added to obtain a polyamic acid solution of about 2500 poise as measured at 23 ° C.
[0083]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 3.
[0084]
(Example 10)
25.7 g (about 62.5 mol% in the total diamine) of PDA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen purge atmosphere, and 58.7 g (about 49.7 mol in total acid dianhydride). %) ODPA, 28.6 g (about 37.5 mol% in total diamine) of ODA was dissolved, and TMHQ 38.6 g (about 22.1 mol% in total acid dianhydride) was gradually added thereto. In addition, the mixture was well stirred and reacted, and then 33.3 g of ODPA (about 28.2 mol% in the total acid dianhydride) was gradually added to obtain a polyamic acid solution of about 2500 poise as measured at 23 ° C.
[0085]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 3.
[0086]
(Example 11)
25.7 g (about 62.5 mol% in total diamine) of PDA was dissolved in 815 g of dimethylacetamide under an ice bath in a nitrogen purge atmosphere, and 55.7 g (about 47.1 mol in total acid dianhydride). %) ODPA, 28.6 g (about 37.5 mol% in total diamine) of ODA was dissolved, and TMHQ 38.6 g (about 22.1 mol% in total acid dianhydride) was gradually added thereto. In addition, the mixture was well stirred and reacted, and then 36.4 g of ODPA (about 30.8 mol% in total acid dianhydride) was gradually added to obtain a polyamic acid solution of about 2500 poise as measured at 23 ° C.
[0087]
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. During the film formation, the film did not sag. A characteristic test was conducted in the same manner as in Example 1. The results are shown in Table 3.
[0088]
[Table 3]

[0089]
(Comparative Example 1)
Dissolve 23.8 g of PDA (about 62.5 mol% in the total diamine) and 26.5 g of ODA (about 37.5 mol% in the total diamine) in 624 g of dimethylacetamide under an ice bath in a nitrogen atmosphere.
TMHQ 50.1g (about 31 mol% in the total acid dianhydride) was gradually added to this, and the mixture was stirred and reacted well. Subsequently, 75.5 g ODPA (about 69 mol% in the total acid dianhydride) was gradually added, A polyamic acid solution of about 2500 poise was obtained by measurement at 23 ° C.
This polyamic acid solution was processed in the same manner as in Example 1 to obtain a polyimide film. The film sag during this film formation. As a result, it was difficult to produce a flat film, but a characteristic test was performed in the same manner as in Example 1 using a slightly flat portion. The results are shown in Table 4.
[0090]
[Table 4]

[0091]
【The invention's effect】
The polyimide film of the present invention has excellent moisture absorption characteristics that are not found in conventional polyimide films for bases, in particular, low hygroscopic expansion, and yet does not fall below the linear expansion coefficient of copper while having high elasticity and high storage elastic modulus. When used as a copper-clad substrate or a TAB tape, extremely excellent warpage characteristics can be exhibited. The polyimide film of the present invention is excellent in flexibility and heat resistance, and does not impair the characteristics required as a base polyimide film, so that it can cope with increasingly fine electronic devices.

Claims (3)

It is obtained by reacting four types of monomers composed of p-phenylenebis (trimellitic acid monoester anhydride), oxydiphthalic dianhydride, p-phenylenediamine, and 4,4'-diaminodiphenyl ether. a Lupo Li imide film prepared from the polyamic acid state, and are storage modulus above 200MPa at 300 ° C. or higher 400 ° C. temperature below,
The addition amount of the monomer is 1-90 mol% of p-phenylenebis (trimellitic acid monoester anhydride) with respect to the total acid dianhydride, and the oxydiphthalic acid dianhydride is the total acid dianhydride. against a 10 to 99 mole%, p-phenylenediamine, and 25 to 90 mol% relative to the total diamine, 4, 4 '- diamino diphenyl ether, at from 10 to 75 mol% relative to the total diamine Yes,
As for the physical properties of the polyimide film, the average linear expansion coefficient of 100 to 200 ° C. is 15 to 30 ppm, the tensile elastic modulus is 4.5 to 8.5 GPa, the elongation at break is 20% or more, and the hygroscopic expansion coefficient is 10 ppm or less. , Tg is 200 ° C. or higher,
The polyimide film is prepared by dissolving 4,4′-diaminodiphenyl ether in an organic solvent, adding p-phenylenebis (trimellitic acid monoester anhydride) to the organic solvent solution, and subsequently adding p-phenylenediamine. polyimide film subsequently oxydiphthalic dianhydride was added to the obtained polyamic acid polymer and, characterized by Rukoto obtained by cyclodehydration with an acid anhydride and a tertiary amine. p-Phenylenebis ( Trimellitic acid monoester anhydride ) And a polyimide film produced from a polyamic acid obtained by reacting four monomers composed of oxydiphthalic dianhydride, p-phenylenediamine, and 4,4′-diaminodiphenyl ether, The storage elastic modulus at a temperature of from ℃ to 400 ℃ is 200 MPa or more,
The addition amount of the monomer is 1-90 mol% of p-phenylenebis (trimellitic acid monoester anhydride) with respect to the total acid dianhydride, and the oxydiphthalic acid dianhydride is the total acid dianhydride. 10-99 mol% with respect to the total, p-phenylenediamine is 25-90 mol% with respect to the total diamine, 4 , 4 ' - Diaminodiphenyl ether is 10-75 mol% with respect to the total diamine,
  As for the physical properties of the polyimide film, the average linear expansion coefficient of 100 to 200 ° C. is 15 to 30 ppm, the tensile elastic modulus is 4.5 to 8.5 GPa, the elongation at break is 20% or more, and the hygroscopic expansion coefficient is 10 ppm or less. , Tg is 200 ° C. or higher,
  In the polyimide film, p-phenylenediamine is dissolved in an organic solvent, oxydiphthalic dianhydride is added, 4,4'-diaminodiphenyl ether is added to the organic solvent solution, and then oxydiphthalic dianhydride is added. In addition, subsequently, p-phenylenebis (trimellitic acid monoester anhydride) is added, and the resulting polyamic acid polymer is obtained by dehydrating and ring-closing using an acid anhydride and a tertiary amine. A polyimide film characterized by that. p-Phenylenebis ( Trimellitic acid monoester anhydride ) And a polyimide film produced from a polyamic acid obtained by reacting four monomers composed of oxydiphthalic dianhydride, p-phenylenediamine, and 4,4′-diaminodiphenyl ether, The storage elastic modulus at a temperature of from ℃ to 400 ℃ is 200 MPa or more,
  The addition amount of the monomer is 1-90 mol% of p-phenylenebis (trimellitic acid monoester anhydride) with respect to the total acid dianhydride, and the oxydiphthalic acid dianhydride is the total acid dianhydride. 10-99 mol% with respect to the total, p-phenylenediamine is 25-90 mol% with respect to the total diamine, 4 , 4 ' - Diaminodiphenyl ether is 10-75 mol% with respect to the total diamine,
As for the physical properties of the polyimide film, an average linear expansion coefficient of 100 to 200 ° C. is 15 to 30 ppm, a tensile elastic modulus is 4.5 to 8.5 GPa, an elongation at break is 20% or more, and hygroscopic expansion. The coefficient is 10 ppm or less, Tg is 200 ° C. or more,
  In the polyimide film, p-phenylenediamine is dissolved in an organic solvent, oxydiphthalic dianhydride is added, 4,4′-diaminodiphenyl ether is added to the organic solvent solution, and then p-phenylenebis ( Trimellitic acid monoester anhydride) is added, followed by addition of oxydiphthalic dianhydride, and the resulting polyamic acid polymer is obtained by dehydration and cyclization using an acid anhydride and a tertiary amine. A polyimide film characterized by that.