JP2004224941A - Polymer film and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film capable of keeping good conductivity even when an oriented film is formed, not requiring formation of a solvent-resistant layer and having high productivity and a conductive substrate and an image display element each using the film and to provide a method for producing the film. <P>SOLUTION: The polymer film comprises a metal oxide and has a coefficient of thermal expansion of the film lower by 10-100 ppm/°C than that of a film not containing the metal oxide. The method for producing the polymer film containing the metal oxide comprises casting or applying a mixture containing a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution and continuously or stepwise heating the mixture. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００３０】
式［Ｉ］中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は、同一又は異なる水素原子又はメチル基であり、Ｘは炭素数５〜１０のシクロアルキレン基、炭素数７〜１５のアラアルキレン基、炭素数１〜５のハロアルキレン基である。Ｘの具体例は、シクロアルキレン基として１，１−シクロペンチレン、１，１−シクロヘキシレン、１，１−（３，３，５−トリメチル）シクロヘキシレン、ノルボルナン−２，２−ジイル、トリシクロ［５．２．１．０^２，６］デカン−８、８’−ジイル、特に１，１−シクロヘキシレン、１，１−（３，３，５−トリメチル）シクロヘキシレンが好適に用いられる。また、アラアルキレン基としては、フェニルメチレン、ジフェニルメチレン、１，１−（１−フェニル）エチレン、９，９−フルオレニレンが挙げられる。またハロアルキレン基としては、２，２−ヘキサフルオロプロピレン、２，２−（１，１，３，３−テトラフルオロ−１，３−ジシクロ）プロピレン等が好適に用いられる。
【００３１】
上記ポリカーボネート樹脂は、一種でもよいし二種以上でもよい。中でも、耐熱性と液晶表示素子に要求される光学特性の観点から、１，１−（３，３，５−トリメチル）シクロヘキシレン又は９，９−フルオレニレンであることが好ましい。これらのビスフェノール成分は、２種類以上を組み合わせて用いることができる。
【００３２】
上記ポリカーボネート系樹脂は、共重合体であってもよく、２種類以上併用して用いてもよい。このようなポリカーボネート系樹脂としては、ビスフェノール成分が（ｉ）ビスフェノールＡであるホモポリマー、（ｉｉ）ビスフェノールＡと、上記式［Ｉ］においてＸが１，１−（３，３，５−トリメチル）シクロヘキシレン又は９，９−フルオレニレンであるビスフェノールとからなる共重合体であることがさらに好ましい。この共重合体の組成は、好ましくはビスフェノールＡが１０〜９０モル％である。
【００３３】
（２）熱硬化性ポリマー
熱硬化性ポリマーとしては、エポキシ系樹脂及び放射線硬化性樹脂が挙げられる。
エポキシ系樹脂は、ポリフェノ−ル型、ビスフェノール型、ハロゲン化ビスフェノール型、ノボラック型のものが挙げられる。エポキシ系樹脂を硬化させるための硬化剤は、公知の硬化剤を用いることができる。例えば、アミン系、ポリアミノアミド系、酸及び酸無水物、イミダゾール、メルカプタン、フェノール樹脂等の硬化剤が挙げられる。中でも、耐溶剤性、光学特性、熱特性等の観点から、酸無水物及び酸無水物構造を含むポリマー又は脂肪族アミン類が好ましく用いられ、特に好ましいのは、酸無水物及び酸無水物構造を含むポリマーである。さらに、公知の第三アミン類やイミダゾール類等の硬化触媒を適量加えることが好ましい。
【００３４】
放射線硬化性樹脂は、紫外線や電子線等の放射線を照射することにより硬化が進行する樹脂であり、具体的には分子又は単体構造内にアクリロイル基、メタクリロイル基、ビニル基等の不飽和二重結合を含む樹脂である。これらの中でも特に、アクリロイル基を含むアクリル系樹脂が好ましい。放射線硬化性樹脂は、一種類の樹脂を用いても、数種の樹脂を混合して用いてもかまわないが、分子又は単位構造内に２個以上のアクリロイル基を有するアクリル系樹脂を用いることが好ましい。こうした多官能アクリレート樹脂としては、例えば、ウレタンアクリレート、エステルアクリレート、エポキシアクリレート等が挙げられるが、これらに限定されるのではない。特に、下記式［ＩＩ］及び／又は［ＩＩＩ］の単位を含み、少なくとも２個以上のアクリロイル基を有するアクリル樹脂であることが好ましい。
【００３５】
【化２】

【００３６】
これらの放射線硬化性樹脂には、紫外線硬化法を用いる場合には、前述の放射線硬化性樹脂に公知の光反応開始剤を適量添加する。
【００３７】
上記のエポキシ系樹脂及び放射線硬化性樹脂には、さらにポリマー分子との相互作用を強めるために、アルコキシシランの加水分解物やシランカップリング剤を混合してもよい。シランカップリング剤としては、一方にメトキシ基、エトキシ基、アセトキシ基等の加水分解可能な反応基を持ち、もう一方にはエポキシ基、ビニル基、アミノ基、ハロゲン基、メルカプト基を有するものが好ましく、この場合、特に好ましくは主成分樹脂に固定するため、同じ反応基を持つビニル基を有するものが好ましく、例えば、信越化学工業（株）のＫＢＭ−５０３、ＫＢＭ−８０３、日本ユニカー（株）製のＡ−１８７などが用いられる。これらの添加量は、０．２〜３質量％であることが好ましい。
【００３８】
次に、本発明のポリマーフィルムの熱膨張係数について説明する。
本発明では、前記金属酸化物、好ましくはゾルゲル反応によって得られた金属酸化物をポリマー中に含有させるため、本発明のポリマーフィルムの熱膨張係数は、前記金属酸化物を含有しないフィルムよりも１０〜１００ｐｐｍ／℃、好ましくは、２０〜１００ｐｐｍ／℃、さらに好ましくは３０〜１００ｐｐｍ／℃低い。
熱膨張は、昇温によりポリマーの熱運動が活発化し、そのためポリマー分子周辺の自由体積が増加するため、体積が膨張する現象である。このため、金属酸化物が存在しないポリマー単体からなるポリマーフィルムでは、該フィルム内のポリマー間の相互作用が弱く、昇温するとポリマーの熱運動が活発化しやすく、該フィルムの熱膨張係数が大きくなりやすい。一方、前記金属酸化物を含有するポリマーフィルムでは、金属酸化物表面とポリマー分子との相互作用により、該フィルム内でのポリマーの熱運動を抑制できるため、該フィルムの熱膨張係数を小さくすることができる。
【００３９】
本発明のポリマーフィルムは、上述のように前記金属酸化物、好ましくはゾルゲル反応によって得られた金属酸化物をポリマー中に含有させるため、該フィルムのＴｇ及びＴｇ変動幅、並びに熱変形温度を増加させることができる。
本発明のポリマーフィルムのＴｇは、金属酸化物を含有しないポリマーフィルム（ポリマー単体からなるフィルム）よりも２℃以上高くすることができ、２〜１００℃高くすることが好ましく、５〜１００℃高くすることがより好ましく、８〜１００℃高くすることがさらに好ましい。また、本発明のポリマーフィルムのＴｇ温度幅は、２℃以上、好ましくは５℃以上、さらに好ましくは８℃以上高くすることが適当である。また、Ｔｇ温度幅の上限値は２０℃であることが適当であり、好ましくは６０℃であり、さらに好ましくは８０℃である。
なお、ここでいう「Ｔｇ温度幅」とは、示差熱分析計（ＤＳＣ）で測定したときにＴｇにおいて低温側のベースラインからシフトし始めた温度と、高温側のベースラインに収斂した温度の差を指す。
【００４０】
本発明のポリマーフィルムのＴｇが金属酸化物を含有しないポリマーフィルムより高くなるのは、金属酸化物表面とポリマーとが相互作用したことによるものである。すなわち、ポリマーフィルムは、Ｔｇを超えると急激に該フィルム内のポリマー分子の運動性が高まるが、該フィルム内に金属酸化物が存在すると、金属酸化物表面とポリマーとが相互作用を起こしてポリマー分子の運動性を抑制するため、さらに高い温度に上昇させないとポリマー運動性が増加しない。
Ｔｇは、例えば、示差熱分析（ＤＳＣ）を用いて所定の昇温速度（例えば、１０℃／分）でポリマーフィルムを昇温させることにより測定することができる。Ｔｇの増加は、例えば、金属酸化物を含むポリマーフィルムのＴｇ（Ｔｇ_１）と金属酸化物を含まないポリマーフィルムＴｇ（Ｔｇ_２）をそれぞれ示差熱分析計（ＤＳＣ）を用いて測定し、Ｔｇ_１値とＴｇ_２値との差から求めることができる。
【００４１】
また、ポリマーフィルムのＴｇ温度幅が増加するのも上記Ｔｇと同様の理由からであり、金属酸化物（好ましくはゾルゲル反応によって得られた金属酸化物）を含有しないポリマーフィルムでは、該フィルム内のポリマー分子がほぼ一斉に同じ温度で運動性を増すため、Ｔｇ温度幅は小さい。これに対し、金属酸化物（好ましくはゾルゲル反応によって得られた金属酸化物）を含有するポリマーフィルムでは、金属酸化物の表面と相互作用しているポリマー分子と、相互作用していないポリマー分子とが混在するため、ポリマー分子の運動性が増加する温度域にも幅が出る。その結果、ポリマーフィルムのＴｇ温度幅が増加する。
Ｔｇの変化幅は、上述のように、示差熱分析計（ＤＳＣ）で測定した場合、Ｔｇにおいて低温側のベースラインからシフトし始めた温度と、高温側のベースラインに収斂した温度との差から求めることができる。
【００４２】
本発明のポリマーフィルムは、金属酸化物を含有しないポリマーフィルムよりも熱変形温度を２℃以上高くすることができ、２〜１００℃高いことが好ましく、５〜１００℃高いことがより好ましく、８〜１００℃高いことがさらに好ましい。
なお、ここでいう「熱変形温度」とは、サンプルフィルムに一定の荷重を加えて昇温させたときに、荷重により急激にサンプルフィルムが伸び始める温度を意味する。
【００４３】
金属酸化物を含有しないポリマーフィルム、特に非晶性ポリマーからなるフィルムでは、Ｔｇを越えると分子の運動性の増加により急激に伸びが発生する。これに対して、本発明の金属酸化物（好ましくはゾルゲル反応によって得られた金属酸化物）を含有するポリマーフィルムは、加熱処理される数百℃の温度域において、上記のような伸びは全く発生しない。これは、上記の金属酸化物がポリマー中に含有されないと、ポリマーフィルム内におけるポリマー分子間の相互作用が弱く、分子間のスリップが発生し、熱と荷重により伸び（変形）が発生しやすいためである。これに対し、上記の金属酸化物がポリマー中に含有されていると、金属酸化物の表面とポリマー分子とが相互作用しており、この相互作用力はポリマー分子同士のそれより大きいため、このような伸び（変形）を抑制することができ、熱変形温度を大きくすることができると考えられるためである。
熱変形温度は、例えば、所定の条件下で、ＴＭＡ（Ｔｈｅｒｍａｌ Ｍｅｃｈａｎｉｃａｌ Ａｎａｌｙｓｉｓ）を用いて昇温に伴うサンプルの寸法変化を測定し、Ｔｇ以下の伸びの外挿線とＴｇ以上の伸びの外挿線との交点から熱変形温度を求めることができる。
【００４４】
［ポリマーフィルムの製造方法］
次に、本発明のポリマーフィルムの製造方法について説明する。
本発明の製造方法では、金属アルコキシド及び酸触媒を含むゾルゲル反応液をモノマー溶液中又はポリマー溶液中に含有してなる混合物を流延又は塗布した後に、該混合物を段階的又は連続的に加熱することにより金属酸化物を含有するフィルムを得る。
以下に、本発明の製造方法を（１）金属アルコキシド及び酸触媒を含むゾルゲル反応液をモノマー溶液中又はポリマー溶液中に含有してなる混合物を得る工程と、（２）前記混合物を連続的又は段階的に加熱することにより金属酸化物を含有するフィルムを得る工程、とに分けて説明する。
【００４５】
（１）金属アルコキシド及び酸触媒を含むゾルゲル反応液をモノマー溶液又はポリマー溶液中に含有してなる混合物を得る工程
本発明の製造方法において、金属酸化物は、ゾルゲル反応、すなわち金属アルコキシドを酸触媒で加水分解又は加水分解及び重縮合させることにより得られる。本工程は、使用されるポリマーの種類によって次の態様に分けられる。
【００４６】
▲１▼ 熱可塑性ポリマーの場合
予めポリマーを溶剤に溶解してポリマー溶液を調液しておき、この調液したポリマー溶液中に、金属アルコキシド及び酸触媒を含有するゾルゲル反応液を混合した混合物を得る。ポリマー溶液のポリマー濃度は、１０〜４０質量％となるように調整され、室温で充分混合・溶解した後、これにゾルゲル反応液を添加する。ポリマー溶液とゾルゲル反応液との混合比は、ゾルゲル反応終了後、これにより得た金属酸化物のポリマーに対する含有率が８〜７０質量％、より好ましくは２０〜６０質量％、さらに好ましくは３０〜５５質量％になるようにする。
【００４７】
ポリマーを溶解するための溶媒としては、例えば、メチルアルコール、エチルアルコール、ｎ−プロピルアルコール、イソプロピルアルコール、ｎ−ブタノール等が挙げられる。溶媒の使用量は、全固形分１００質量部当たり、３０〜１００質量部である。
【００４８】
上記溶媒中にはシランカップリング剤を入れておくことが好ましい。シランカップリング剤としては、例えば、珪素原子に直接に、又は酸素原子若しくは−ＯＣＯ−基を介して結合した炭化水素基を有し、これらの炭化水素基の少なくとも一つは二重結合、ハロゲン原子、エポキシ基、酸無水物基、アルコキシカルボニル基、アミノ基、アクロイル基、メタクリロイル基、アクリルアミノ基、メタクリルアミノ基又はハロアシルアミノ基を有するものが挙げられる。この中で、特にエポキシ基やアミノ基を有するシランカップリング剤であることが好ましい。シランカップリング剤の混合比は、ポリマー１００質量部に対して、シランカプリング剤は０．１〜１０質量部であり、好ましくは１〜５質量部である。
【００４９】
ゾルゲル反応液とポリマー溶液との混合溶液は、５０〜２００℃以下、より好ましくは５５〜１９０℃、さらに好ましくは６０〜１８０℃で加熱処理することが好ましい。ゾルゲル反応における加熱処理の詳細については後述する。
【００５０】
▲２▼ 熱硬化性ポリマーの場合
熱硬化性ポリマーの場合、上記のゾルゲル反応液を熱硬化性ポリマーのモノマー溶液に混合して重合する。重合して得られたポリマー成分に対するゾルゲル反応により得られた金属酸化物の含有率は、８〜７０質量％、より好ましくは２０〜６０質量％、さらに好ましくは３０〜５５質量％になるように調整される。以降の工程は、上記の熱可塑性ポリマーと同様にして溶剤に溶解し、シランカップリング剤を添加する。但し、溶解温度は、室温〜８０℃で行うことが好ましい。
【００５１】
（２）連続的又は段階的に加熱することにより金属酸化物を含有するフィルムを得る工程
本発明の製造方法では、ゾルゲル反応液をポリマー溶液中に含有させた混合物を、段階的又は連続的に加熱処理し、ゾルゲル反応を促進させることができる。前記混合物を段階的に加熱する場合には、前記混合物を流延又は塗布してフィルム状にし、該フィルム状の混合物を加熱処理することにより第一フィルムを得る初期反応工程と、前記第一フィルムをさらに加熱処理することにより金属酸化物を含有するポリマーからなるフィルムを得る後期反応工程とを有することが好ましい。
なお、ここにいう「第一フィルム」とは、初期反応工程を経た後に得られるゲル化された金属酸化物とポリマーとからなるフィルムのことをいう。
以上説明した（１）及び（２）の工程を有する本発明の製造方法の概略を図１に示す。
【００５２】
ゾルゲル反応における初期反応工程の温度と後期反応工程の温度は、少なくとも後期反応工程の温度が初期反応工程の温度よりも高ければ特に制限はない。例えば、初期反応工程では、４０以上１１５℃未満の温度、より好ましくは５０〜９０℃の温度、さらに好ましくは６０〜８５℃の温度で反応させた後、後期反応工程では、１００〜２００℃の温度、より好ましくは１１０〜１９０℃の温度、さらに好ましくは１２０〜１８５℃の温度で反応させて、初期反応工程の温度と後期反応工程の温度との間に温度差を設けることができる。
【００５３】
一般に、ゾルゲル反応は１００〜２００℃の一定の温度で実施される。これに対し、本発明の製造方法では、ゾルゲル反応を初期反応工程において比較的低温（例えば、１１５℃未満）で行い、かつ後期反応工程において初期反応工程よりも高温で行う。このようにゾルゲル反応における加熱を段階的に行うことにより、ゾルゲル反応で得られた金属酸化物とポリマーとの相互作用をより強くすることができる。
【００５４】
初期反応工程において比較的低温で処理するのは、ゾルゲル反応の反応速度を遅くし、生成される金属酸化物のゲルを微細化させるためである。これにより、表面積の大きな金属酸化物のゲルが得られ、金属酸化物がポリマーと相互作用しやすくなると考えられる。その上、ゾルゲル反応の反応速度は遅いため、ポリマーの一部（末端）が金属酸化物のゲル中に取り込まれて、金属酸化物とポリマーとの相互作用がさらに強められると考えられる。
したがって、初期反応工程を高温（例えば、１１５℃以上）で処理した場合と比べると、生成されるゲルのサイズが大きくなることもなく、またポリマーが金属酸化物のゲル内に拡散する前にゲル化が進行することもないため、ポリマーと金属酸化物の相互作用が弱くなることもない。
【００５５】
一方、後期反応工程において高温（例えば、１１０℃以上）で処理するのは、初期反応工程よりもさらにゾルゲル反応を促進させるためである。すなわち、初期反応工程よりも高温で処理することにより、ゲルの密度を高めることができ、その結果、ゲル間の隙間をなくすことができる。ゲル化の隙間は、熱膨張係数を上昇させる主要因であるから、後期反応工程を経ることにより、熱膨張係数を低下させ、耐熱性を向上することができる。
なお、上記の初期反応工程を省略して後期反応工程における高温処理だけを実施した場合、急激な密度上昇が起こり、大きな収縮応力が生じ、ゾルゲル反応中にクラックが発生し、却って熱膨張係数の大きいものとなってしまう。
以上のとおり、本発明の製造方法は、初期反応工程で一度微細なゲルを形成した後に、後期反応工程でこのゲルを固めることにより、クラックがなく、かつ密度の高い層を形成することができるというメリットが得られる。
【００５６】
本発明の製造方法では、さらに初期反応工程から後期反応工程までの間に４０〜２００℃の温度で熱処理する工程を一つ以上含んでいてもよい。さらに本発明の製造方法では、初期反応工程の温度から後期反応工程の温度まで連続的に昇温させて（すなわち、温度勾配をもたせて）両反応工程の間に温度差を設けることもできる。
【００５７】
初期反応工程及び後期反応工程の反応時間は、それぞれ３〜６０分であることが好ましく、５〜４０分であることがより好ましく、７〜３０分であることがさらに好ましい。反応時間が３〜６０分であれば、ゾルゲル反応を段階的に良好に促進させることができる。
【００５８】
本発明の製造方法では、さらに初期反応工程と後期反応工程との間に、初期反応工程で得られた第一フィルムに対して５〜３０ｋｇ／ｍ、好ましくは７〜２５ｋｇ／ｍ、さらに好ましくは８〜２２ｋｇ／ｍの張力を加えて第二フィルムを得る張力付加工程を有することが好ましい。
ここにいう「第二フィルム」は、第一フィルムに張力を加えて得られたフィルムであり、金属酸化物とポリマーの相互作用が強められたフィルムである。その理由は、前記の張力を第一フィルムに加えることで、初期反応工程で生成された初期の金属酸化物のゲルに微細なクラックを入れることができる。このクラックの中にポリマーが入り込み、いっそう金属酸化物とポリマーとの相互作用を強くすることができるためである。
【００５９】
張力付加工程後の後期反応工程における加熱処理により、ゾルゲル反応が促進されてゲル化が進むため、ゲルの微細なクラック内にポリマーが閉じ込められた状態で固定することができ、ポリマーと金属酸化物の相互作用を第二フィルムよりもさらに強くすることができる。
なお、張力を付加する方向は特に限定されないが、ポリマーフィルムの搬送方向に対して並行や垂直方向が好ましい。
以上、説明した本発明の製造方法の工程の概略を図２に示す。
【００６０】
さらに、本発明の製造方法では、初期反応工程において、フィルム状の上記混合物の一方の面（表面）ともう一方の面（裏面）との間に０．５〜１００℃、好ましくは２〜４０℃、より好ましくは３〜３０℃、さらに好ましくは３〜２０℃の温度差を設けることが好ましい。
フィルム状の混合物の表裏面に温度差を設けることにより、金属酸化物の濃度勾配をフィルム状の混合物の厚み方向に与えることができる。すなわち、フィルム状の混合物の高温側の面では低温側の面に比べてゾルゲル反応が進行しやすく、低温側から未反応成分が拡散してくる。このため、高温側の金属酸化物の濃度を高くすることができる。金属酸化物濃度が高まると、熱膨張係数が小さくなり、より耐熱性の高い（高温にしても熱膨張の差で透明導電層が破断しにくい）フィルムとなる。一方、フィルム状の混合物の厚み方向全面に亘り金属酸化物濃度を高くしても、熱膨張係数を同様に小さくできるが、全体の金属酸化物濃度が高くなりすぎて、脆いフィルムになりやすい。
【００６１】
本発明の製造方法では、上記フィルムの脆さを回避するため、特に導電層側の表面における金属酸化物濃度を高くして熱膨張係数を小さくすることが好ましく、当該表面側を高温で処理し、裏面側を低温で処理して、全体の金属酸化物濃度は高くしないようにすることが好ましい。
【００６２】
このような初期反応工程におけるフィルム状の混合物の表裏面での温度勾配は、温度制御機構を有する基板上に流延することにより行うことができる。すなわち、基板の下にパネルヒーターや赤外線ヒーターを設置したり、所定の温度に制御した流体を通過させたりすることにより行うことができる。
【００６３】
次に、本発明の製造方法におけるフィルムの製膜法について説明する。
本発明の製造方法において、フィルムの製膜は使用するポリマーの種類により次のような態様で行うことができる。
（Ａ）熱可塑性ポリマーの場合
上述のように調製したゾルゲル反応液とポリマー溶液との混合反応溶液を定法に従い、濾過、脱泡を行う。これを所定の厚みになるよう調整したスリットの間から、鏡面研磨した支持体（バンド又はドラム）上に流延する。これを前述した初期反応工程及び後期反応工程で昇温しながらゾルゲル反応を進行させる。このような複数工程による昇温は、すべて上記支持体上で行ってもよく、初期反応工程の低温反応を支持体上で行い、これを剥ぎ取ってから後期反応工程の高温反応を行ってもよい。より好ましくは後者である。
【００６４】
（Ｂ）熱硬化性ポリマーの場合
前述の熱可塑性ポリマーと同様である。但し、熱硬化性ポリマーの場合、初期反応工程中に前述のように第一フィルムの表裏面に温度差を設けて行うことが好ましい。熱硬化性ポリマーの硬化反応は、上記の反応工程のいずれで行ってもよいが、好ましくは、初期反応工程の低温反応後から後期反応工程の高温反応前までの間に実施することが好ましい。光硬化型の場合、これらの工程中に紫外線ランプを使用することで達成できる。熱硬化型の場合、後期反応工程における乾燥熱を利用して硬化させることが好ましい。
【００６５】
本発明のポリマーフィルムの厚みは、熱硬化性ポリマー及び熱可塑性ポリマーのいずれを使用した場合であっても、７０〜２００μｍであることが好ましく、８０〜１８０μｍであることがより好ましく、９０〜１５０μｍであることがさらに好ましい。また、ヘーズは、いずれの場合も３％以下であることが好ましく、２％以下であることがより好ましく、１％以下であることが好ましい。
【００６６】
本発明のポリマーフィルムの光線透過率は、本発明の基板フィルムがディスプレイ等の画像表示素子として利用されることから、透明なフィルム、すなわち９０％以上であることが好ましく、９２％以上であることが好ましく、９３％以上であることがさらに好ましい。
【００６７】
次に本発明の導電性基板について説明する。
［導電性基板］
本発明の導電性基板は、上記フィルムの少なくとも一方の面に導電層（Ｅ）を有する。
＜導電層（Ｅ）＞
本発明の導電性基板において、導電層は、公知の金属膜、金属酸化物膜などが適用できる。中でも、透明性、導電性及び機械特性の点から、金属酸化物膜を用いることが好ましい。例えば、不純物としてスズ、テルル、カドミウム、モリブテン、タングステン、フッ素、亜鉛、ゲルマニウム等を添加した酸化インジウム、酸化カドミウム及び酸化スズ、不純物としてアルミニウムを添加した酸化亜鉛、酸化チタン等の金属酸化物膜が挙げられる。中でも酸化スズを主とし、酸化亜鉛を２〜１５質量％含有した酸化インジウムの薄膜が、透明性及び導電性に優れており、好ましく用いられる。
【００６８】
上記導電層（Ｅ）の２５℃６０％ＲＨで測定した表面抵抗は、１〜５００Ω／ｓｑであることが好ましく、１〜２００Ω／ｓｑであることがよりに好ましく、２〜１００Ω／ｓｑであることがさらに好ましく、３〜６０Ω／ｓｑであることが最も好ましい。表面抵抗が１〜５００Ω／ｓｑの範囲であれば、例えば液晶表示素子の場合、長期間に亘り液晶表示素子の表示欠陥が発生せず、高信頼性の液晶表示素子を提供できる。
表面抵抗は、例えば、２５℃６０％ＲＨの環境下で調湿した後、所定の装置（例えば、ＫＥＩＴＨＬＥＹ製の８００９ ＲＥＳＩＳＴＩＶＩＴＹ ＴＥＳＴ ＦＩＸＴＵＲＥとＫＥＩＴＨＬＥＹ製の６５１７Ａ型など）を用いて表面電気抵抗値として求めることができる。
【００６９】
上記導電層（Ｅ）の膜厚は、２０〜５００ｎｍであることが好ましく、５０〜３００ｎｍであることが好ましい。２０ｎｍ以上であれば、十分な導電性を得ることができ、上限値は特に制限されないが、５００ｎｍ以下であることが好ましい。
【００７０】
さらに上記導電層の光線透過率は、透明導電性基板に適用することを考慮すれば、少なくとも８０％であることが必要であり、８３％以上であることが好ましく、８５％以上であることがさらに好ましい。光線透過率が８０％以上であれば、視認性の低下という問題も生じないため好ましい。
【００７１】
上記導電層（Ｅ）は、例えばスパッタ法、真空蒸着法、イオンプレーティング法、プラズマＣＶＤ法等の気相中より材料を堆積させて膜形成する気相堆積法により本発明のフィルムの少なくとも一方の面に作製される。中でも優れた導電性及び透明性が得られるという観点から、スパッタリング法が好ましい。
【００７２】
このようなスパッタ法、真空蒸着法、イオンプレーティング法、プラズマＣＶＤ法の好ましい真空度は１．３３ｍＰａ〜６．６５Ｐａ（０．０１〜５０ｍＴｏｒｒ）であり、より好ましくは６．６５ｍＰａ〜１．３３Ｐａ（０．０５〜１０ｍＴｏｒｒ）である。
上記導電層（Ｅ）を設ける前に、基材フィルムをプラズマ処理（逆スパッタ）、コロナ処理などの表面処理を施しておくことが好ましい。また導電層（Ｅ）を設けている間に５０〜２００℃の温度で昇温してもよい。
【００７３】
上記導電層（Ｅ）は、液晶画像素子を配向させる目的で、積層側の表面上にポリイミドからなる配向膜を設けることができる。配向膜を構成するポリイミドとしては、例えば、ポリアミック酸及び可溶性ポリイミドを出発原料とし、これを熱や紫外線で硬化したものなどを挙げることができる。また、配向膜の厚さは、１０〜５００ｎｍ、好ましくは２０〜２００ｎｍ程度である。
【００７４】
＜ガスバリア層（Ｂ）＞
導電性基板におけるガス透過性を抑制するため、本発明の導電性基板では、さらにガスバリア層（Ｂ）を設けることが好ましい。ガスバリア層（Ｂ）は、例えば、珪素、アルミニウム、マグネシウム、亜鉛、ジルコニウム、チタン、イットリウム、タンタルからなる群から選ばれる１種又は２種以上の金属を主成分とする金属酸化物、珪素、アルミニウム、ホウ素の金属窒化物又はこれらの混合物を挙げることができる。この中でも、ガスバリア性、透明性、表面平滑性、屈曲性、膜応力、コスト等の点から珪素原子数に対する酸素原子数の割合が１．５〜２．０の珪素酸化物を主成分とする金属酸化物を用いることが好適である。
【００７５】
上記ガスバリア層（Ｂ）の厚さは、１０〜３００ｎｍであることが好ましく、３０〜２００ｎｍであることがさらに好ましい。ガスバリア層の厚さが１０ｎｍ以上あれば、充分なガスバリア性能が得られ、３００ｎｍ以下であれば、透明性も得られるため好ましい。
【００７６】
上記ガスバリア層（Ｂ）は、導電層（Ｅ）と同じ側及び反対側のいずれに設けても構わないが、導電層（Ｅ）とは反対側に設ける方が好ましい。
【００７７】
上記ガスバリア層（Ｂ）は、例えば、スパッタ法、真空蒸着法、イオンプレーティング法、プラズマＣＶＤ法等の気相中より材料を堆積させて膜形成する気相堆積法により作製することができる。中でも、特に優れたガスバリア性を得るという観点から、スパッタリング法が好ましい。
【００７８】
上記のスパッタ法、真空蒸着法、イオンプレーティング法、プラズマＣＶＤ法の好ましい真空度は１．３３ｍＰａ〜６．６５Ｐａ（０．０１〜５０ｍＴｏｒｒ）であり、より好ましくは６．６５ｍＰａ〜１．３３Ｐａ（０．０５〜１０ｍＴｏｒｒ）である。
上記ガスバリア層（Ｂ）を設ける前に、プラズマ処理（逆スパッタ）、コロナ処理のように基材フィルムに表面処理を加えることが好ましい。また透明導電層を設けている間に５０〜２００℃に昇温してもよい。
【００７９】
＜保護層（Ｄ）＞
本発明の導電性積層フィルムは、上記導電層の割れの防止及び基材フィルムの耐溶剤性を得る目的で、保護層（Ｄ）を設けることも好ましい。
保護層を形成する材料としては、一般に、保護コート剤、ハードコート剤として用いられるものであれば特に限定されない。例えば、アクリル系、メラミン系、アルキッド系、ウレタン系などの紫外線硬化型、熱硬化型のハードコート剤、脂環式構造含有重合体などの樹脂が挙げられる。中でも、透明性及び耐熱性に優れ、しかも隣接する層との密着性の観点からは、好ましくはアクリル系、シリコン系のハードコート剤、より好ましくは硬化型アクリル系のハードコート剤、さらに好ましくは紫外線硬化型アクリル系のハードコート剤、特に好ましくは多官能のアクリル系紫外線硬化型のハードコート剤を保護層形成材料として用いることができる。
【００８０】
アクリル系紫外線型ハードコート剤は、反応性モノマー及び／又は反応性オリゴマーと、光重合開始剤とを含むものが用いられる。反応性モノマーとしては、例えば、シクロヘキシルアクリレート、シクロヘキシルメタクリレート、グリシジルメタクリレート、イソボルニルメタクリレート、その他の高級アルキルアクリレート等の単官能アクリレートモノマー；エチレングリコール、ジエチレングリコール、トリプロピレングリコール、ブチレングリコール、テトラメチロールプロパン、トリメチロールプロパン、ペンタエリストール等のポリオール類に２個以上のアクリレートが結合した多官アクリレートモノマー等を挙げることができる。中でも、１〜６官能アクリレートが好ましく、より好ましくは２、３官能アクリレート、さらに好ましくは脂環式構造含有アクリレートである。
【００８１】
上記反応性オリゴマーとしては、例えば、末端にアクロイル基を持つポリエステルアクリレート、分子鎖中にエポキシ基かつ末端にアクリロイル基を持つエポキシアクリレート又はポリウレタンアクリレート、分子鎖中に二重結合を持つ不飽和ポリエステル、１，２−ポリブタジン、その他のエポキシ基を持つオリゴマーを挙げることができる。
【００８２】
上記光重合開始剤としては、例えば、２，２−ジメトキシ−２フェニルアセトフェノン、２，２−ジエトキシ−２フェニルアセトフェノン、塩素化アセトフェノン等のアセトフェノン類；ベンゾフェノン類；ベンジル、メチルオルソベンゾイルベンゾエート、ベンゾイルアルキルエーテル等のベンゾインエーテル類；α，α’−アゾイソブチルニトリル、２，２’−アゾビスプロパン、ヒドラゾン等のアゾ化合物；ベンゾイルパーオキサイド、ジターシャリーブチルパーオキサイド等の有機パーオキサイド類；ジフェニルサルファイド、ジベンゾイルサルファイト等のジフェニルジサルファイド類を挙げることができる。
【００８３】
上記アクリル系ハードコート剤としては、例えば、Ｔｇが５〜１１０℃で、分子量１〜１０万、酸価０．５〜４のアクリル系樹脂が用いられ、さらにシランカップリング剤を含むことが好ましい。Ｔｇが１１０℃を越えると樹脂が固く、ワニスが皮張りしやすくなり、塗工適性も極めて悪く、塗工面と前記導電層（Ｅ）との密着力が低下する。一方、Ｔｇが５℃未満であると、非常にブロッキングしやすくなり、後工程で加熱工程がある場合、アクリル系樹脂が流動する可能性があり、その場合かなり大きな寸法変化を起こす。
【００８４】
アクリル系樹脂の分子量は、１〜１０万、好ましくは４〜７万である。分子量が１万未満であると保護層（Ｄ）の溶剤耐性が劣り、１０万を越えるとアクリル系樹脂が汎用溶媒に溶解し難く、さらにワニス化適性が悪く、ゲル化しやすい。酸価は１〜４であることが好ましい。酸価が１未満であると耐溶剤性が劣り、４を越えると加水分解のおそれがある。
【００８５】
上記保護層（Ｄ）に密着改良のためにシランカップリング剤を配合することがより好ましい。シランカップリング剤としては、珪素原子に直接に、又は酸素原子若しくは−ＯＣＯ−基を介して結合した炭化水素基を有し、これらの炭化水素基の少なくとも一つは二重結合、ハロゲン原子、エポキシ基、酸無水物基、アルコキシカルボニル基、アミノ基、アクロイル基、メタクリロイル基、アクリルアミノ基、メタクリルアミノ基又はハロアシルアミノ基を有するものが挙げられる。このうち特にエポキシ基やアミノ基を有する化合物が好ましい。前記樹脂とシランカップリング剤との混合比は、樹脂１００重量部に対して、シランカプリング剤０．１〜１０質量部であり、好ましくはシランカプリング剤１〜５質量部である。
【００８６】
上記保護層（Ｄ）を積層する方法としては、例えば、グラビアコーティング、リバースコーティング、キスコーティング、スピンコーティング、ワイヤーバーコーティング、ロールコーティング、ナイフコーティングなどが挙げられるが、本発明の積層方法は特に限定されるものではない。上記保護層（Ｄ）の塗布・乾燥後には、高圧水銀灯等の紫外線を発生する光源から紫外線を照射することにより、硬化が短時間で起こり、保護層（Ｄ）が形成される。
【００８７】
上記保護層（Ｄ）の厚みは、０．０１〜１０μｍの範囲から適宜選択でき、０．１〜４μｍであることが好ましい。保護層（Ｄ）の厚さが０．０１μｍ以上であれば、充分な密着性が得られ、１０μｍ以下であれば、透明性が低下することもないため好ましい。
【００８８】
上記保護層（Ｄ）には、さらに適宜、酸化防止剤、紫外線吸収剤、帯電防止剤、滑剤、ブロッキング防止剤などを配合してよい。このような添加剤を添加する場合、その添加量は、アクリル系樹脂の質量に対して１０質量％以内である。
形成される保護層（Ｄ）は、最終的に得られる層の必要機能が得られていれば、２重積層や多重積層でもよく、異種類のシランカップリング剤を添加した異種類のアクリル系樹脂を積層してもよい。
【００８９】
［層構成］
本発明の基板は、上述のようにフィルムの少なくとも一方の面に導電層（Ｅ）を有する。さらに、本発明の基板は、ガスバリア層（Ｂ）や保護層（Ｄ）を有することもできる。その他、本発明の効果を低下させない範囲内で、フィルムとその上の層との密着性、あるいは各層の密着性を強化する目的で、アンカー層（下塗層）（例えば、ウレタン樹脂等の硬化樹脂層）を設けることもできる。
【００９０】
本発明の基板の好ましい構成としては、フィルム（Ｓ）、ガスバリア層（Ｂ）、保護層（Ｄ）、導電層（Ｅ）を、導電層（Ｅ）／フィルム（Ｓ）／ガスバリア層（Ｂ）／保護層（Ｄ）の順に有する態様を挙げられる。
【００９１】
本発明の導電性基板は、Ｔｇが１６０℃以上、好ましくは、１８０〜４００℃、さらに好ましくは、２００〜３５０℃である。また、本発明の導電性基板の光線透過率は、８０％以上であり、８５％以上であることが好ましく、９０％以上であることがさらに好ましい。
また、本発明の導電性基板のガスバリア性能は、４０℃９０％ＲＨで測定した水蒸気透過率が０．０１〜５ｇ／ｍ^２・ｄａｙ・ａｔｍであることが好ましく、０．０３〜３ｇ／ｍ^２・ｄａｙ・ａｔｍであることがより好ましく、０．０５〜２ｇ／ｍ^２・ｄａｙ・ａｔｍであることがさらに好ましい。また、４０℃９０％ＲＨで測定した酸素透過率は０．０１〜１ｍｌ／ｍ^２・ｄａｙであり、０．０１〜０．７ｍｌ／ｍ^２・ｄａｙであることが好ましく、０．０１〜０．５ｍｌ／ｍ^２・ｄａｙであることがさらに好ましい。ガスバリア性能は、例えば、ＭＯＣＯＮ法によって測定することができる。
【００９２】
［画像表示素子］
本発明のフィルム及び導電性基板の用途は特に限定されないが、光学特性と機械特性に優れるため、画像表示素子の透明電極用基板として好適に用いることができる。ここでいう「画像表示素子」とは、円偏光板・液晶表示素子、タッチパネル、有機ＥＬ素子などを意味する。
【００９３】
＜円偏光板＞
本発明の導電性基板にλ／４板と偏光板を積層し、円偏光板を作成することができる。この場合、λ／４の遅相軸と偏光板の吸収軸とが４５ーになるように積層する。このような偏光板は、長手方向（ＭＤ）に対し４５ー方向に延伸されているものを用いることが好ましく、例えば、特開２００２−８６５５５４号公報に記載のものを好適に用いることができる。
【００９４】
＜液晶表示素子＞
反射型液晶表示装置は、下から順に、下基板、反射電極、下配向膜、液晶層、上配向膜、透明電極、上基板、λ／４板、そして偏光膜からなる構成を有する。本発明の基板は、前記透明電極及び上基板として使用することができる。カラー表示の場合には、さらにカラーフィルター層を反射電極と下配向膜との間、又は上配向膜と透明電極との間に設けることが好ましい。
透過型液晶表示装置は、下から順に、バックライト、偏光板、λ／４板、下透明電極、下配向膜、液晶層、上配向膜、上透明電極、上基板、λ／４板及び偏光膜からなる構成を有する。このうち本発明の基板は、前記上透明電極及び上基板として使用することができる。カラー表示の場合には、さらにカラーフィルター層を下透明電極と下配向膜との間、又は上配向膜と透明電極との間に設けることが好ましい。
液晶セルは特に限定されないが、より好ましくはＴＮ（Ｔｗｉｓｔｅｄ Ｎｅｍａｔｉｃ ）型、ＳＴＮ（Ｓｕｐｐｅｒ Ｔｗｉｓｔｅｄ Ｎｅｍａｔｉｃ）型またはＨＡＮ（Ｈｙｂｒｉｄ Ａｌｉｇｎｅｄ Ｎｅｍａｔｉｃ）型、ＶＡ（Ｖｅｒｔｉｃａｌｌｙ Ａｌｉｇｎｍｅｎｔ）型、ＥＣＢ型（Ｅｌｅｃｔｒｉｃａｌｌｙ Ｃｏｎｔｒｏｌｌｅｄ Ｂｉｒｅｆｒｉｎｇｅｎｃｅ）、ＯＣＢ型（Ｏｐｔｉｃａｌｌｙ Ｃｏｍｐｅｎｓａｔｏｒｙ Ｂｅｎｄ）、ＣＰＡ型（Ｃｏｎｔｉｎｕｏｕｓ Ｐｉｎｗｈｅｅｌ Ａｌｉｇｎｍｅｎｔ）であることが好ましい。
【００９５】
＜タッチパネル＞
タッチパネルは、特開平５−１２７８２２号公報、特開２００２−４８９１３号公報等に記載されたものに応用することができる。
【００９６】
【実施例】
以下に本発明の実施例を挙げて本発明をさらに具体的に説明する。なお、以下の実施例に示される材料、使用量、割合、処理内容、処理手順等は、本発明の趣旨を逸脱しない限り適宜変更することができる。したがって、本発明の範囲は以下に示す具体例により限定的に解釈されるべきものではない。
なお、実施例中、部及び％は、特に断らない限り質量基準である。また、実施例中における各種の測定は、下記のとおり行った。
【００９７】
［測定法］
１．ガラス転移温度（Ｔｇ）及びＴｇ温度幅の測定
以下の条件で示差熱分析計（ＤＳＣ）を用いて測定する。
サンプル量：２０ｍｇ
昇温速度：１０℃／分
測定温度域：３０〜３００℃
Ｔｇにおいて比熱が不連続に変化するため、低温側ベースライン、過渡域（低温側ベースラインと高温側ベースラインを直線的に変化する領域）、高温側ベースラインと変化するが、本発明では以下のようにＴｇ、Ｔｇ温度幅を求める。
Ｔｇ：低温側ベースラインと過渡域を外挿する直線の交点の温度
Ｔｇ温度幅：低温側ベースラインと過渡域を外挿する直線の交点の温度と、過渡域と高温側ベースラインとを外挿する直線の交点の温度の差
【００９８】
２．熱変形温度、熱膨張係数、熱ヒステリシスの測定
（１）下記条件でＴＭＡ（Ｔｈｅｒｍａｌ Ｍｅｃｈａｎｉｃａｌ Ａｎａｌｙｓｉｓ）測定を行う。すなわち、昇温に伴うサンプルの寸法変化を測定する。
サンプル幅：３ｍｍ
チャック間：２５．４ｍｍ
昇温速度：３℃／分
測定温度域：３０〜２００℃
（２）下記方法で熱変形温度、熱膨張係数を求める。
▲１▼ 熱変形温度：昇温に伴い伸びが発生するが、Ｔｇ近傍から伸び量が急激に増加する。Ｔｇ以下の伸びの外挿線とＴｇ以上の伸びの外挿線の交点を熱変形温度（℃）とする。
▲２▼ 熱膨張係数：Ｔｇ以下の熱膨張の寸法変化（チャック間長に対する比率：ｐｐｍ）と温度（℃）の傾きから求める（ｐｐｍ／℃）。
（３）熱ヒステリシスは、上記サンプル幅、チャック間で、２５℃から熱変形温度より２０℃低い温度まで３℃／分で昇温した後、直ちに２５℃までー３℃／分で降温し、開始点と終点の寸法変化を求める。
【００９９】
３．表面抵抗の測定
（１）初期表面抵抗の測定
２５℃６０％ＲＨに３時間以上調湿後、ＫＥＩＴＨＬＥＹ製の８００９ ＲＥＳＩＳＴＩＶＩＴＹ ＴＥＳＴ ＦＩＸＴＵＲＥとＫＥＩＴＨＬＥＹ製の６５１７Ａ型とを用いて初期抵抗（Ｒ_０）測定した。
（２）熱処理後の表面抵抗の測定
サンプルを空気恒温槽を用いて、無張力下で吊るして１７５℃３０分間、加熱処理した。これを２５℃６０％ＲＨに３時間以上調湿後、上記と同様にして表面抵抗（Ｒ_１７５）を測定した。
（３）表面抵抗変化率の測定
（Ｒ_１７５）と（Ｒ_０）の差の絶対値を（Ｒ_０）で割り、百分率で示したものを表面抵抗変化率（％）とした。
【０１００】
（実施例１）
１．基材フィルムの作製
（１）熱可塑性樹脂溶液の調液
下記ポリマーをメチレンクロライドに２０質量％になるように溶解した。
▲１▼ ＭＰＣ−１
ビスフェノールＡ（ＢｉｓＡ）と９，９−ビス（４−ヒドロキシ−３−メチルフェニル）フルオレン（ＢＣＦ）を、ＢｉｓＡ／ＢＣＦ＝１／１（モル比）で混合したポリカーボネート共重合体（Ｔｇ：２２５℃）。
▲２▼ ＭＰＣ−２
ＢｉｓＡとビスフェノールＡと３，３，５−トリメチル−１，１−ジ（４−フェノール）シクロヘキシリデン（ＩＰ）をＢｉｓＡ／ＩＰ＝２／３（モル比）で混合したポリカーボネート共重合体（Ｔｇ：２０５℃）。
▲３▼ ＰＥＳ（ポリエーテルスルホン）
住友ベークライト製スミライトＦＳ−１３００（Ｔｇ：２２０℃）。
▲４▼ ＣＯＣ（シクロオレフィンコポリマー）
ポリノルボルネン（ジェイエスール（株）製アートン、Ｔｇ：１６０℃）。
【０１０１】
（２）熱硬化性樹脂のプレポリマー溶液の調液
下記のプレポリマー１００質量部を、１−メトキシ−２−プロパノールを３００質量部、開始剤として１−ヒドロキシシクロヘキシルフェニルケトンを２質量部、シランカップリング剤（信越化学株式会社製ＫＢＭ−５０３）を１質量部それぞれ混合した。
▲１▼ ＥｐＡｃ
分子量約１０４０のエポキシアクリレートプレポリマー（昭和高分子株式会社製ＶＲ−６０）
▲２▼ Ａｃ
アクリル系樹脂（ガラス転移点１０５℃、分子量６７０００、酸価２のアクリル（三菱レイヨン株式会社ＬＲ−１０６５））
▲３▼ ＤＣＰＡ
ジメチロールトリシクロデカンジアクリレート（共栄社化学社製「ライトアクリレートＤＣＰ−Ａ」）
▲４▼ ＵＡ
ウレタンアクリレート（新中村化学製「ＮＫオリゴＵ−１５ＨＡ」）
▲５▼ ＰｈＲ
フェノキシ樹脂（Ｐｈｅｎｏｘｙ Ａｓｓｏｃｉａｔｅｓ 製「ＰＡＰＨＥＮ」）
▲６▼ ＰＩ
ポリイソシアネート（日本ポリウレタン工業製「コロネート」）
【０１０２】
（３）流延ドープの調製
上記熱可塑性樹脂溶液の調液及び熱硬化性樹脂のプレポリマー溶液の調液後、下記ゾルゲル液を添加した。なお、金属酸化物の含有率（ポリマーに対するゾルゲル反応後の金属酸化物の質量比）は表１に示した。
▲１▼ シリカ系ゾルゲル液（Ｓｉ系）
２−プロパノール１８００質量部の混合溶媒に、酢酸８８質量部を加えた後、２−（３，４−エポキシシクロヘキシル）エチルトリメトキシシラン６４０質量部、及び３−アミノプロピルトリメトキシシラン（ＥＣＨＥＴＭＯＳ）１５４質量部をそれぞれ混合した。
▲２▼ アルミナ系ゾルゲル液（Ａｌ系）
アルミニウムイソプロポキシド（和光純薬（株）製、固形分４０質量％）及びｎ−プロピルアルコールを混合し、１０ｍｏｌ／Ｌの塩酸を滴下し、滴下終了後Ｎ，Ｎ−ジメチルベンジルアミンを加えた後、アルミニウムイソプロポキシド１５質量部の溶液を得た。
▲３▼ シリカアルミナ系（ＳｉＡｌ系）
ＴＥＯＳ（テトラエトキシシラン）８０質量％、アミノプロピルトリエトキシシラン１０質量％、グリシジルプロピルトリエトキシシラン５質量％とメチルプロピルアクリルエトキシシラン５質量％をｎ−プロピルアルコールに溶解した後、２ｍｏｌ／Ｌの塩酸を滴下した。
【０１０３】
（４）製膜
上記の混合物をダイコーティング法によりステンレスバンド上に流延した。混合物をバンド上で加熱し、初期反応させた。この時のフィルム状の混合物の表面及び裏面におけるそれぞれの反応温度及び反応時間を表１に示した。このような表裏面の温度差はステンレスバンドの下側にヒーターを設けて実施した。
次いで、バンド上から第一フィルムを剥ぎ取り、ケーシング内をロール搬送させながら、後期反応を行った。この時の反応温度及び反応時間を表１に示した。この後、残留溶媒濃度が０．０８質量％になるまで乾燥させた後、両端をトリミングし、ナーリング加工した後、巻き取った。このようにして得られ基材フィルムの厚みを表１に示す。なお、本発明ではいずれも１．５ｍ幅で３０００ｍ長製膜した。
このようにして得た基材フィルムのＴｇ、Ｔｇ温度幅、熱変形温度、熱膨張係数を上述の方法で測定した。結果を表１に示す。
【０１０４】
さらに、得られた基材フィルムをＮＭＰ中に２５℃で１０分間浸漬し、耐溶剤性を調べた。浸漬後、白化に伴うヘーズの増大を下記手法で測定した。結果を表１に示す。
［耐溶剤性評価法］
浸漬前のヘーズを測定する（Ｈｂとする）
浸漬後のヘーズを測定する（Ｈａとする）
Ｈｂ／Ｈａを耐溶剤性とした
（１に近いほど耐溶剤性が良好で、小さいほど耐溶剤性が低いことを示す）
【０１０５】
本発明の基材フィルムは、いずれもヘーズが１％以下、光線透過率が９０％以上の良好な透明性を示した。
【０１０６】
【表１】

【０１０７】
表１より本発明のフィルムは、いずれも比較例と比べて熱膨張係数が１０ｐｐｍ／℃以上低くなっていた（減少量が１０ｐｐｍ／℃以上）。また、Ｔｇ及びＴｇ温度幅は、いずれも２℃以上高くなっていた（温度増加が２℃以上）。これより本発明のポリマーフィルムは、耐熱性が向上されて透明電極用基板として好適に用いることが可能であることが分かった。さらに、本発明のポリマーフィルムは、いずれも耐溶剤性が良好であった。これより、本発明のフィルムは、これまでのガスバリア性フィルムで形成されていた耐溶剤性層がなくても良好な耐溶剤性を示すため、以下に述べる単純な層構成を実現できていることが分かる。また、本発明の製造方法を用いれば、本発明の製造方法を用いないで作製されたフィルム（各比較例）と比べて、Ｔｇ、Ｔｇ温度幅、熱変形温度、熱膨張係数、耐溶剤性及び熱ヒステリシスの値がいずれも良好であった。
さらに、ポリマーフィルムが金属酸化物を含有していても、本発明の製造方法を用いないで作製したポリマーフィルム（基材フィルム−４３）は、金属酸化物を含有しないポリマーフィルム（基材フィルム−２５）と物性値が同程度であった。このことから、単に金属酸化物を含有するポリマーフィルムではなく、本発明の製造方法で得られた金属酸化物を含有するポリマーフィルムにおいて、耐熱性が向上されることが分かる。
さらに、金属酸化物を含有しない基材フィルム４４は、本発明の温度及び張力条件で処理しても、金属酸化物を含有し、かつ本発明の温度及び張力条件で処理した基材フィルム１に比べて、Ｔｇの温度上昇、Ｔｇの温度幅、熱変形温度の上昇、熱膨張係数の減少、耐溶剤性の向上は極めて少なく、いずれも本発明の範囲外であった。同様に、金属酸化物を含有するが、本発明の温度及び張力条件で処理しなかった基材フィルム４５は、金属酸化物を含有し、かつ本発明の温度及び張力条件で処理した基材フィルム１に比べて、Ｔｇの温度上昇、Ｔｇの温度幅、熱変形温度の上昇、熱膨張係数の減少、及び耐溶剤性の向上は極めて少なく、本発明の範囲に入らなかった。これは熱硬化樹脂を用いた場合でも同様で、基材フィルム１８と基材フィルム４６、４７を比較すれば明らかである。
【０１０８】
（実施例２）
１．ガスバリア層の形成
実施例１で得た基材フィルムの片面の下塗層上に、下記バリヤー層のいずれかを選び（表１に記載）、表２に示される厚みの基板を得た。
▲１▼ ＳｉＯ_２層（ＳｉＯ層）
ＤＣマグネトロンスパッタリング法により、Ｓｉ０_２をターゲットとし、０．６６５ｍＰａ（５ｍＴｏｒｒ）の真空下で、Ａｒ雰囲気下、出力５ｋＷでスパッタリングした。
▲２▼ ＳｉＯｘＮｙ層（ＳｉＮ層）
ＲＦマグネトロンスパッタリング法により、Ｓｉをターゲットとし、Ｏ２、Ｎ２を導入しながら、０．６６５ｍＰａ（５ｍＴｏｒｒ）の真空下で、出力５ｋＷで成膜し、ＳｉＯ_ｘＮ_ｙ膜（ｘ＝１、ｙ＝１）を得た。
【０１０９】
２．導電層の形成
基材フィルムを１００℃に加熱しながら、ＩＴＯ（Ｉｎ_２Ｏ_３ ９５ｗｔ％、Ｓｎ０_２ ５ｗｔ％）をターゲットとしＤＣマグネトロンスパッタリング法により、０．６６５ｍＰａ（５ｍＴｏｒｒ）の真空下で、Ａｒ雰囲気下、出力５ｋＷで１４０ｎｍの厚みのＩＴＯ膜からなる透明導電層を、バリヤー層の反対面の下塗り層上に設けた。この厚みを表２に示した。
【０１１０】
３．保護層の形成
前記バリヤー層上に、下記処方の塗布液を常温にて攪拌溶解後、バーコーターで３μｍ（乾燥後）の厚みになるように塗工し、８０℃、１０分の条件で加熱した後、紫外線を照射をした。
アクリル系樹脂 １００質量部
（Ｔｇ：１０５℃，分子量：６７，０００， 酸価：２のアクリル（三菱レイヨン株式会社ＬＲ−１０６５））
シランカップリング剤 １質量部
（信越化学株式会社製 ＫＢＭ−５７３；Ｎ−フェニル−γ−アミノプロピルトリメトキシシラン）
酢酸ブチル ４００質量部
【０１１１】
４．評価
このようにして得られた基板を、上記の方法により表面抵抗を測定した。さらに下記の手法に従って水蒸気透過率及び酸素透過率を測定した。結果を表２に示す（表２のフレッシュ特性）。さらにこれらの基板を１８０℃（配向膜形成温度）に３時間曝し、これらを測定した。結果を表２に示す（表２のサーモ後特性）。
【０１１２】
（１）水蒸気透過度
ＭＯＣＯＮ社製、パーマトランＷ１Ａを用いて、４０℃９０％ＲＨ雰囲気下において２４時間測定し、水蒸気透過率を測定した。
（２）酸素透過率
ＭＯＣＯＮ社製、ＯＸ−ＴＲＡＮ １０／５０Ａを用いて４０℃９０％ＲＨ雰囲気下において２４時間測定し、酸素透過率を測定した。
【０１１３】
【表２】

【０１１４】
表２より本発明の導電性基板は、いずれも水蒸気透過率及び酸素透過率の双方において良好なガスバリア性能を示した。これより、本発明の導電性基板は、優れたガスバリア性を有することが分かる。また、本発明の導電性基板は、加熱処理後の表面電気抵抗が殆ど増加していなかった。これより本発明の導電性基板は、加熱処理後においても良好な導電性を維持できていることが分かる。
一方、本発明の製造方法を用いれば、本発明の製造方法を用いないで作製されたフィルム（基材フィルム−４１）と比べて、ガスバリア性及び表面抵抗がいずれも良好であった。また、本発明の製造方法を用いないで作製されたフィルム（基材フィルム−４１）は、金属酸化物を含有しないフィルム（基材フィルム−２５）と物性値が同程度であった。このことから、本発明の製造方法で得られたフィルムは、優れたガスバリア性と導電性が維持されていることが分かる。
また、熱硬化性樹脂を用いたものは熱ヒステリシスが小さくサーモテストを３回繰り返した後の黒点故障発生率も低く、さらに良好であった。
さらに、金属酸化物を含有しない基材フィルム４４は、本発明の温度及び張力条件で処理しても、金属酸化物を含有し、かつ本発明の温度及び張力条件で処理した基材フィルム１に比べて、サーモ後の表面抵抗、水蒸気・酸素透過率が大きく、黒点・色ずれ故障が発生しやすく、良好な結果は得られなかった。
同様に、金属酸化物を含有せず、かつ本発明の温度及び張力条件で処理しなかった基材フィルム４５は、金属酸化物を含有し、かつ本発明の温度及び張力条件で処理した基材フィルム１に比べて、サーモ後の表面抵抗、水蒸気・酸素透過率が大きく、黒点・色ずれ故障が発生しやすく、良好な結果は得られなかった。これは熱硬化樹脂を用いた場合でも同様であり、基材フィルム１８と基材フィルム４６及び４７とを比較すれば明らかである。
【０１１５】
（実施例３）
１．円偏光膜の作製
本発明の基板の透明導電層の反対側に、特開２０００−８２６７０５号公報、特開２００２−１３１５４９号公報に記載のλ／４板を積層し、さらにその上に特開２００２−８６５５５４号公報に記載の偏光板を積層し円偏光板を作成した。なお偏光膜の透過軸とλ／４板の遅相軸との角度は４５°となるように配置した。
【０１１６】
２．液晶表示装置の作製
▲１▼ ＴＮ型液晶表示装置の作製
本発明の複層フィルム、微細な凹凸が形成されたアルミニウム反射電極を設けたガラス基板の透明導電（ＩＴＯ）層、電極側に、それぞれポリイミド配向膜（ＳＥ−７９９２、日産化学（株）製）を形成した。２００℃で３０分間、加熱処理したが、本発明のものは全く抵抗値の増加、ガス透過性の増加は見られなかった。一方比較例はいずれも２倍以上に増大した。
これにラビング処理を行った後、１．７μｍのスペーサーを介して、二枚の基板（ガラス基板と複層フィルム）を配向膜が向かい合うように重ねた。二つの配向膜のラビング方向は、１１０゜の角度で交差するように、基板の向きを調節した。基板の間隙に、液晶（ＭＬＣ−６２５２、メルク社製）を注入し、液晶層を形成した。このようにして、ツイスト角が７０゜、Δｎｄの値が２６９ｎｍのＴＮ型液晶セルを作製した。
複層フィルムのＩＴＯと反対面に上記λ／４板、偏光板を積層し反射型液晶表示装置を作成した。本発明の基板を用いたものは良好な画像が得られた。一方比較例を用いたものは、ガスバリア性の低下に起因する黒点故障（画層部に細かな黒い点となり画像が表示されない）や、導電層の割れに起因する色ずれが発生した。
【０１１７】
３．ＳＴＮ型液晶表示装置の作製
本発明の基板、ＩＴＯ層を積層したガラス基板の透明導電（ＩＴＯ）層側に、それぞれポリイミド配向膜（ＳＥ−７９９２、日産化学（株）製）を形成した。２００℃で３０分熱処理したが、本発明のものは全く抵抗値の増加、ガス透過性の増加は見られなかった。一方比較例はいずれも２倍以上に増大した。
６．０μｍのスペーサーを介して二枚の基板を配向膜が向かい合うように重ねた。二つの配向膜のラビング方向は、６０゜の角度で交差するように、基板の向きを調節した。基板の隙間に、液晶（ＺＬＩ−２９７７、メルク社製）を注入し、液晶層を形成した。このようにしてツイスト角が２４０゜、Δｎｄの値が７９１ｎｍのＳＴＮ型液晶セルを作製した。
この液晶セルのガラス基板側に上記λ／４板、偏光板を積層し、その下に導光板、光源を置いた。複層フィルム側に上記λ／４板、偏光板を積層し、透過型液晶表示装置を得た。本発明の複層フィルムを用いたものは良好な画像が得られた。一方比較例を用いたものは、表２に示したように、ガスバリア性の低下に起因する黒点故障（画層部に細かな黒い点となり画像が表示されない）や、導電層の割れに起因する色ずれが発生したなお、これらの発生率は液晶表示基板に組上げ全面白表示にしたときの、これらの発生領域の面積を目視で確認し、全表示面積に対する比率で示したものである。
【０１１８】
４．タッチパネルの作製
タッチパネルは、特開平５−１２７８２２号号公報、特開２００２−４８９１３号号公報等に記載に従い作成した。本発明のものは良好な性能を示し上記故障は発生しなかた。
【０１１９】
５．有機ＥＬ素子の作製
本発明の光学補償フィルムを特開２０００−２６７０９７号公報に従い、観察者側から順に保護タック（最表面に反射防止機能層付き）／上記円偏光板（本発明の基板の導電層を有機ＥＬ側にする）／有機ＥＬ素子／反射電極の構成とした。本発明のものは良好な性能を示し上記故障は発生しなかた。
【０１２０】
【発明の効果】
以上説明したとおり、本発明のフィルムは、比較的小さな熱膨張係数を有する金属酸化物を比較的大きな熱膨張係数を有するポリマー中に含有する。これにより本発明のフィルムを用いた導電性基板は、基材フィルムと導電層間の熱膨張係数差による寸法歪を小さくできるため、耐熱性が向上し、かつ良好な導電性を維持できる。
【０１２１】
また、本発明フィルムの製造方法は、ゾルゲル反応により得られた金属酸化物をポリマーに分散含有させ、さらに、ゾルゲル反応が温度差のある複数の工程、好ましくは張力を加えて行われる。これにより本発明の製造方法であれば、ゾルゲル反応を用いない場合と比べて、ポリマー分子と金属酸化物との相互作用を向上させ、ポリマーの運動性を抑制することができるため、フィルムの耐熱性を向上させ、配向膜を形成した後においても良好な導電性を維持できる。
【０１２２】
さらに、本発明の画像表示素子は、上記のフィルムを透明電極用基板として用いているため、優れた耐熱性と良好な導電性を維持できる。
【図面の簡単な説明】
【図１】本発明の製造方法を示す概略説明図（その１）である。
【図２】本発明の製造方法を示す概略説明図（その２）である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polymer film, a conductive substrate and an image display device using the film, and a method for producing the film.
[0002]
[Prior art]
In recent years, in the field of flat panel displays such as liquid crystal display elements, attempts have been made to replace conventional glass substrates with plastic substrates as transparent electrode substrates in order to meet the needs for improved breakage resistance, lighter weight and thinner thickness. It has been broken. When a plastic substrate is used as the transparent electrode substrate, a semiconductor film such as indium oxide, tin oxide or tin-indium alloy oxide, gold, silver or palladium alloy is oxidized on the plastic substrate for the purpose of imparting conductivity. A metal film such as a film, and a conductive layer formed by combining the semiconductor film and the metal film are provided.
[0003]
However, since the plastic substrate is inferior in heat resistance and gas barrier property as compared with the glass substrate, it is not suitable for producing a high-definition pattern and has a drawback that it lacks durability. Many studies have been reported to improve the drawbacks of such plastic substrates.
[0004]
For example, when a polyimide film for aligning a liquid crystal layer is provided on a conductive layer, a modified polycarbonate (modified PC), polyethersulfone (PES) or A conductive laminated film using a heat-resistant film made of a cycloolefin copolymer has been reported (for example, see Patent Documents 1 to 3).
[0005]
However, even if the above heat-resistant film is used, sufficient heat resistance as a substrate cannot be obtained. That is, the glass transition temperature (hereinafter referred to as “Tg”) of the above heat-resistant film exceeds 200 ° C., but after providing a conductive layer on these heat-resistant films, a temperature of 150 ° C. or higher for providing an alignment film. When heat-treating, there was a problem that the conductivity and gas barrier properties of the conductive laminated film were greatly reduced.
[0006]
Furthermore, in an optical application such as a liquid crystal display panel, since optical isotropy is required, a plastic substrate made of an amorphous polymer is used. However, the amorphous polymer is easily dissolved in the solvent, and the amorphous polymer is dissolved in the solvent (N-methylpyrrolidone: NMP) used when forming the alignment film. Therefore, conventionally, in order to prevent the amorphous polymer from being dissolved by the solvent, it has been necessary to coat a solvent resistant layer on both surfaces of the plastic substrate. For this reason, unlike conventional substrates for optical applications, the plastic substrate for optical applications has an increased layer structure corresponding to the solvent-resistant layer, and the manufacturing cost is high, so that improvement has been desired.
[0007]
Further, a base film in which inorganic oxide fine particles are contained in a thermoplastic resin is also known (see, for example, Patent Document 4). However, a sufficient heat resistance effect cannot be obtained by simply mixing inorganic oxide fine particles into a thermoplastic resin, and further improvement has been desired.
[0008]
[Patent Document 1]
JP 2000-227603 A (Claim 8, Claim 22, paragraphs [0009] to [0019])
[Patent Document 2]
JP 2000-284717 A (paragraphs [0010], [0021])
[Patent Document 3]
JP 2001-150584 A (paragraphs [0023] to [0025])
[Patent Document 4]
JP 2001-14950 A (claims 2 to 4, paragraphs [0007] and paragraphs [0015] to [0034])
[0009]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and an object of the present invention is to maintain productivity even when an alignment film is formed, and to improve productivity that does not require the formation of a solvent-resistant layer. The object is to provide a high film, a conductive substrate and an image display device using the film, and a method for producing the film.
[0010]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that a decrease in heat resistance in the transparent electrode substrate is caused by a difference in thermal expansion coefficient between the conductive layer and the base film.
In the case of a liquid crystal display element, an alignment film made of polyimide is provided on a conductive layer laminated on a substrate film for the purpose of imparting orientation as described above. This alignment film is usually subjected to heat treatment at a high temperature of 150 ° C. or higher in order to increase the strength. However, the thermal expansion coefficient of the conductive layer is 3 to 10 × 10.^-6/ ° C., and the coefficient of thermal expansion of the base film (4 to 10 × 10^-5In view of the fact that it is about 1/10 compared to / ° C.), when the temperature is higher than 150 ° C., the base film tends to stretch greatly due to thermal expansion, while the conductive layer has little elongation. A tensile force is applied to the interface. For this reason, dimensional distortion resulting from the linear expansion coefficient occurs at the interface between the conductive layer and the alignment film. As a result, the conductive layer is broken and the conductivity of the conductive layer is lowered.
[0011]
The present inventors disperse a metal oxide having a small thermal expansion coefficient in a polymer composed of an organic substance having a large thermal expansion coefficient against the dimensional strain caused by the thermal expansion coefficient between the conductive layer and the base film. And by adjusting the temperature and tension during the preparation of the metal oxide utilizing the sol-gel reaction, the present inventors have found that the above problems can be solved, and have reached the present invention.
[0012]
That is, the object of the present invention is achieved by the following metal oxide-containing film, a conductive substrate and an image display device using the film, and a method for producing the film.
(1) A polymer film containing a metal oxide, wherein the thermal expansion coefficient of the film is 10 to 100 ppm / ° C. lower than that of the film not containing the metal oxide.
(2) A polymer film containing a metal oxide, wherein the film has a heat distortion temperature 2 to 100 ° C. higher than that of the film not containing the metal oxide.
(3) A polymer film containing a metal oxide, wherein the glass transition temperature of the film is 2 to 100 ° C. higher than that of the film not containing the metal oxide.
(4) A polymer film containing a metal oxide, wherein the glass transition temperature width of the film is 2 to 20 ° C. higher than that of the film not containing the metal oxide.
(5) The polymer film according to (1), wherein the heat distortion temperature of the polymer film is 2 ° C. or more higher than that of the film not containing the metal oxide.
(6) The polymer film as described in (5), wherein the glass transition temperature of the polymer film is 2 ° C. or more higher than that of the film not containing the metal oxide.
(7) The polymer film according to (6), wherein the glass transition temperature width of the polymer film is 2 to 20 ° C. higher than that of the film not containing the metal oxide.
(8) The film according to any one of (1) to (7), wherein the polymer forming the polymer film is a thermosetting polymer.
(9) A conductive substrate having a conductive layer on at least one surface of the polymer film according to any one of (1) to (8).
(10) The conductive substrate according to (9), wherein the conductive layer has a surface resistance of 1 to 100 Ω / sq in an environment of 25 ° C. and 60% RH.
(11) The conductive substrate according to (9) or (10), further including a gas barrier layer between the polymer film and the conductive layer.
(12) Water vapor permeability in an environment of 40 ° C. and 90% RH is 0.01 to 5 g / m²The conductive substrate according to (11), wherein the conductive substrate is day · atm.
(13) Oxygen permeability in an environment of 40 ° C. and 90% RH is 0.01 to 1 ml / m²-The conductive substrate according to (11) or (12), wherein the conductive substrate is day.
(14) The conductive substrate according to any one of (9) to (13), wherein a glass transition temperature (Tg) of the conductive substrate is 160 ° C. or higher.
(15) An image display device comprising the conductive substrate according to any one of (9) to (14).
(16) A circularly polarizing plate comprising the conductive substrate according to any one of (9) to (14).
(17) A liquid crystal display device comprising the conductive substrate according to any one of (9) to (14).
(18) A touch panel comprising the conductive substrate according to any one of (9) to (14).
(19) An organic electroluminescence device comprising the conductive substrate according to any one of (9) to (14).
(20) A method for producing a polymer film by casting or coating a mixture containing a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution, wherein the casting is performed. Alternatively, a method for producing a polymer film, comprising adding a metal oxide to the polymer film by heating the applied mixture stepwise or continuously.
(21) A method for producing a polymer film by casting or coating a mixture containing a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution, the metal alkoxide and An initial reaction step of obtaining a first film by heat treatment after casting or coating a mixture containing a sol-gel reaction solution containing an acid catalyst in a monomer solution or a polymer solution; And a tension applying step for obtaining a second film by applying a tension of 5 to 30 kg / m to the first film.
(22) The method for producing a polymer film according to (21), further comprising a late reaction step of obtaining a polymer film containing a metal oxide by further heat-treating the second film.
(23) In the initial reaction step, heat treatment is performed by providing a temperature difference of 0.5 to 100 ° C. between one side of the film-like mixture and the other side (20) The manufacturing method of the polymer film in any one of-(22).
(24) The method for producing a polymer film according to any one of (20) to (23), wherein the temperature of the late reaction step is higher by 10 to 200 ° C. than the temperature of the initial reaction step.
(25) The method for producing a polymer film according to any one of (20) to (24), wherein the polymer forming the polymer film is a thermosetting polymer.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Below, the polymer film of this invention, its manufacturing method, an electroconductive board | substrate, and an image display element are demonstrated in detail.
In the present specification, “to” is used as a meaning including numerical values described before and after the lower limit value and the upper limit value.
[0014]
[Polymer film containing metal oxide]
<Metal oxide>
The kind of metal oxide that can be used in the film of the present invention is not particularly limited, and various metal oxides can be used. Preferably, an oxide of a colorless metal such as silicon, aluminum, zinc, zirconium, indium, tin, titanium, or lead is used from the viewpoint of transparency. Of these, silica, alumina, and zirconium oxide are preferably used.
[0015]
The metal oxide is not particularly limited as described above, but from the viewpoint of improving the affinity with the polymer, that is, enhancing the interaction at the interface between the metal oxide and the polymer, the metal obtained by the sol-gel reaction. It is preferable to use an oxide.
Hereinafter, the metal oxide obtained by the sol-gel reaction will be described.
[0016]
The metal oxide is obtained by a sol-gel reaction, that is, a metal alkoxide is hydrolyzed and / or hydrolyzed and polycondensed with an acid catalyst. (A) Metal alkoxide
In the sol-gel reaction, alkoxysilane and / or metal alkoxide other than alkoxysilane is used.
As the metal alkoxide other than alkoxysilane, it is preferable to use zirconium alkoxide, titanium alkoxide, aluminum alkoxide or the like. These can also be used in combination. Preferred combinations include, for example, (1) alkoxysilane alone, (2) alkoxysilane and alkoxyzirconium, and (3) aluminum alkoxide and / or titanium alkoxide. And the like.
Specific examples of the alkoxysilane, zirconium alkoxide, aluminum alkoxide, and titanium alkoxide include the following.
[0017]
(A) Alkoxysilane
Examples of the alkoxysilane include silica alkoxide such as tetramethoxysilane, tetraethoxysilane, methyltriethoxysilane, and ethyltriethoxysilane, polymerizable metal alkoxide such as methylpropylacryl triethoxysilane, glycidylpropyltriethoxysilane, and aminopropyl. Examples thereof include metal alkoxides having a functional group such as triethoxysilane, phenyltriethoxysilane, and benzyltrimethoxysilane. Among them, the general formula Si (OR¹)₄(However, R¹Is a lower alkyl group having 1 to 6 carbon atoms. Is preferably an alkoxysilane represented by, for example, Si (OCH₃)₄, Si (OC₂H₅)₄Etc. are preferable.
[0018]
(B) Zirconium alkoxide
Zirconium alkoxide has the general formula Zr (OR²)₄(However, R²Is a lower alkyl group having 1 to 6 carbon atoms. ) Is preferred. Specifically, Zr (OCH₃)₄, Zr (OC₂H₅)₄, Zr (O-iso-C₃H₇)₄, Zr (OC₄H₉)₄Etc. These zirconium alkoxides may be used in combination of two or more.
When using zirconium alkoxide together with the above alkoxysilane, the content of zirconium alkoxide is preferably 25 parts by mass or less with respect to 100 parts by mass of alkoxysilane.
[0019]
(C) Aluminum alkoxide
Aluminum alkoxide is triethoxyaluminum or general formula Al₂(OR³)₃(However, R³Is a lower alkyl group having 1 to 6 carbon atoms. ) Is preferred. Specifically, Al₂(OCH₃)₃, Al₂(OC₂H₅)₃, Al₂(OC₃H₇)₃, Al₂(OC₄H₉)₃Etc. These aluminum alkoxides may be used in combination of two or more.
When aluminum alkoxide is used in combination with alkoxysilane, the content of aluminum alkoxide is preferably 25 parts by mass or less with respect to 100 parts by mass of alkoxysilane.
[0020]
(D) Titanium alkoxide
Titanium alkoxides include trimethoxy titanium and general formula Ti (OR⁴)₄(However, R⁴Is a lower alkyl group having 1 to 6 carbon atoms. ) Is preferred. Specifically, Ti (OCH₃)₄, Ti (OC₂H₅)₄, Ti (OC₃H₇)₄, Ti (OC₄H₉)₄Etc. These titanium alkoxides may be used in combination of two or more.
When titanium alkoxide is used in combination with alkoxysilane, the content of titanium alkoxide is preferably 5 parts by mass or less with respect to 100 parts by mass of alkoxysilane.
[0021]
(B) Acid catalyst
The acid catalyst is preferably a mineral acid such as sulfuric acid, hydrochloric acid or nitric acid, and an organic acid such as acetic acid or tartaric acid. Among these, the acid catalyst is preferably an organic acid, and more preferably acetic acid, because it is necessary to react in the polymer as described later.
The amount of the acid catalyst used is 0.001 to 0.005 mol per 1 mol of metal alkoxide (alkoxysilane and other metal alkoxide, when alkoxysilane and other metal alkoxide are contained), preferably about 0.01 mole.
[0022]
The sol-gel reaction is carried out under heating, but in the present invention, it is preferable to perform heat treatment continuously or stepwise as described later.
[0023]
The size of the metal oxide is preferably 0.4 μm or less, more preferably 0.2 μm or less, in terms of the equivalent sphere diameter. When the equivalent sphere diameter is 0.4 μm or less, good transparency can be obtained and a sufficient heat resistance effect can be obtained.
Here, the “equivalent sphere diameter” means the diameter of the sphere when the size of the metal oxide particle is converted to a sphere having the same volume as the metal oxide particle.
[0024]
The content of the metal oxide with respect to the polymer to be described later is 8 to 70% by mass, preferably 20 to 65% by mass, and more preferably 30 to 60% by mass. If it is 8% by mass or more, sufficient heat resistance can be obtained, and if it is 70% by mass or less, it is preferable because good transparency and good film forming properties can be obtained.
[0025]
<Polymer>
The polymer that can be used in the polymer film of the present invention is not particularly limited as long as the metal oxide can be dispersed, and may be either a thermoplastic polymer or a thermosetting polymer. A thermosetting polymer is preferable. The thermosetting polymer is preferable because it can cause the sol-gel reaction to proceed at the stage of a highly diffusible monomer or oligomer, and can further maintain affinity with the metal oxide. For this reason, the thing using a thermosetting polymer can make a thermal dimensional hysteresis small.
[0026]
Thermal hysteresis refers to the difference between the dimension at 25 ° C. before the start of measurement when measuring the thermal dimensional change and the dimension when returned to 25 ° C. after the start of measurement. Such thermal hysteresis causes fine separation between the polymer and the metal oxide due to the stress of the difference in thermal expansion when the temperature is raised, resulting in irreversible dimensional distortion. For this reason, when a thermosetting polymer is used as the polymer, the affinity between the polymer and the metal oxide can be increased, and there is an effect of suppressing the occurrence of thermal hysteresis.
[0027]
Hereinafter, the thermoplastic polymer and thermosetting polymer that can be used in the film of the present invention will be described more specifically.
(1) Thermoplastic polymer
The thermoplastic polymer preferably has a Tg of 135 to 250 ° C, more preferably 150 to 240 ° C, and still more preferably 160 to 230 ° C. Further, in order to achieve optical uniformity, an amorphous polymer is preferable. Examples of such thermoplastic resins include the following (in parentheses indicate Tg).
Polycarbonate (PC: 140 ° C.), alicyclic polyolefin (for example, ZEONOR 1600: 160 ° C. manufactured by Nippon Zeon Co., Ltd.), polyarylate (PAr: 210 ° C.), polyether sulfone (PES: 220 ° C.), polysulfone (PSF: 190 ° C.), cycloolefin copolymer (COC: compound of Example 1 of JP 2001-150584 A: 162 ° C.), fluorene ring-modified polycarbonate (BCF-PC: Example 4 of JP 2000-227603 A) Compound: 225 ° C.), alicyclic modified polycarbonate (IP-PC: compound of Example-5 of JP 2000-227603 A: 205 ° C.), acryloyl compound (Example 1 of JP 2002-80616 A) Compound: 300 ° C. or higher).
[0028]
Among these, preferred are polyarate (PAr), polyethersulfone (PES), f-carbonate (f-PC), c-carbonate (c-PC), fluorene ring-modified polycarbonate (BCF-PC), alicyclic ring It is a modified polycarbonate (IP-PC), and particularly preferred are a fluorene ring-modified polycarbonate (BCF-PC) and an alicyclic modified polycarbonate (IP-PC).
Examples of the fluorene ring-modified polycarbonate (BCF-PC) include polycarbonate resins containing 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) and bisphenol represented by the following formula [I] as a bisphenol component. .
[0029]
[Chemical 1]

[0030]
In formula [I], R¹, R², R³And R⁴Are the same or different hydrogen atoms or methyl groups, and X is a cycloalkylene group having 5 to 10 carbon atoms, an aralkylene group having 7 to 15 carbon atoms, or a haloalkylene group having 1 to 5 carbon atoms. Specific examples of X include 1,1-cyclopentylene, 1,1-cyclohexylene, 1,1- (3,3,5-trimethyl) cyclohexylene, norbornane-2,2-diyl, and tricyclohexane as cycloalkylene groups. [5.2.1.0^2,6Decane-8,8'-diyl, particularly 1,1-cyclohexylene and 1,1- (3,3,5-trimethyl) cyclohexylene are preferably used. Examples of the aralkylene group include phenylmethylene, diphenylmethylene, 1,1- (1-phenyl) ethylene, and 9,9-fluorenylene. As the haloalkylene group, 2,2-hexafluoropropylene, 2,2- (1,1,3,3-tetrafluoro-1,3-dicyclo) propylene and the like are preferably used.
[0031]
The polycarbonate resin may be one kind or two or more kinds. Of these, 1,1- (3,3,5-trimethyl) cyclohexylene or 9,9-fluorenylene is preferable from the viewpoint of heat resistance and optical properties required for the liquid crystal display element. These bisphenol components can be used in combination of two or more.
[0032]
The polycarbonate resin may be a copolymer or may be used in combination of two or more. Examples of such a polycarbonate-based resin include (i) bisphenol A as a bisphenol component, (ii) bisphenol A, and X in the above formula [I], 1,1- (3,3,5-trimethyl) More preferably, it is a copolymer comprising cyclohexylene or bisphenol which is 9,9-fluorenylene. The composition of this copolymer is preferably 10 to 90 mol% of bisphenol A.
[0033]
(2) Thermosetting polymer
Examples of the thermosetting polymer include epoxy resins and radiation curable resins.
Examples of the epoxy resin include polyphenol type, bisphenol type, halogenated bisphenol type, and novolac type. A known curing agent can be used as the curing agent for curing the epoxy resin. Examples thereof include curing agents such as amines, polyaminoamides, acids and acid anhydrides, imidazoles, mercaptans, and phenol resins. Among them, from the viewpoints of solvent resistance, optical properties, thermal properties, etc., polymers or aliphatic amines containing acid anhydrides and acid anhydride structures are preferably used, and particularly preferred are acid anhydrides and acid anhydride structures. It is a polymer containing. Furthermore, it is preferable to add an appropriate amount of a known curing catalyst such as tertiary amines and imidazoles.
[0034]
A radiation curable resin is a resin that cures when irradiated with radiation such as ultraviolet rays and electron beams. Specifically, it is an unsaturated double molecule such as an acryloyl group, a methacryloyl group, or a vinyl group in a molecule or a single structure. A resin containing a bond. Among these, an acrylic resin containing an acryloyl group is particularly preferable. The radiation curable resin may be one kind of resin or a mixture of several kinds of resins, but an acrylic resin having two or more acryloyl groups in the molecule or unit structure should be used. Is preferred. Examples of such polyfunctional acrylate resins include, but are not limited to, urethane acrylates, ester acrylates, epoxy acrylates, and the like. In particular, an acrylic resin containing units of the following formula [II] and / or [III] and having at least two acryloyl groups is preferable.
[0035]
[Chemical 2]

[0036]
In the case of using an ultraviolet curing method, an appropriate amount of a known photoreaction initiator is added to these radiation curable resins.
[0037]
In order to further strengthen the interaction with the polymer molecule, an alkoxysilane hydrolyzate or a silane coupling agent may be mixed with the epoxy resin and the radiation curable resin. As the silane coupling agent, one having a hydrolyzable reactive group such as a methoxy group, an ethoxy group, or an acetoxy group and the other having an epoxy group, a vinyl group, an amino group, a halogen group, or a mercapto group. Preferably, in this case, those having a vinyl group having the same reactive group are particularly preferably used for fixing to the main component resin. For example, KBM-503, KBM-803 of Shin-Etsu Chemical Co., Ltd., Nippon Unicar Co., Ltd. A-187 made by) or the like is used. These addition amounts are preferably 0.2 to 3% by mass.
[0038]
Next, the thermal expansion coefficient of the polymer film of the present invention will be described.
In the present invention, since the metal oxide, preferably a metal oxide obtained by a sol-gel reaction, is contained in the polymer, the polymer film of the present invention has a thermal expansion coefficient of 10 than that of the film not containing the metal oxide. -100 ppm / ° C, preferably 20-100 ppm / ° C, more preferably 30-100 ppm / ° C.
Thermal expansion is a phenomenon in which the thermal expansion of the polymer is activated by the temperature rise, so that the free volume around the polymer molecule is increased, so that the volume expands. For this reason, in a polymer film composed of a single polymer having no metal oxide, the interaction between the polymers in the film is weak, and when the temperature rises, the thermal motion of the polymer is likely to be activated, and the thermal expansion coefficient of the film increases. Cheap. On the other hand, in the polymer film containing the metal oxide, since the thermal motion of the polymer in the film can be suppressed by the interaction between the metal oxide surface and the polymer molecule, the thermal expansion coefficient of the film should be reduced. Can do.
[0039]
Since the polymer film of the present invention contains the metal oxide, preferably a metal oxide obtained by sol-gel reaction, in the polymer as described above, the Tg and Tg fluctuation range of the film and the heat distortion temperature are increased. Can be made.
The Tg of the polymer film of the present invention can be 2 ° C. or higher, preferably 2 to 100 ° C., and preferably 5 to 100 ° C. higher than that of a polymer film containing no metal oxide (a film composed of a single polymer) More preferably, it is more preferably 8 to 100 ° C. higher. The Tg temperature range of the polymer film of the present invention is suitably 2 ° C or higher, preferably 5 ° C or higher, more preferably 8 ° C or higher. Moreover, it is appropriate that the upper limit value of the Tg temperature range is 20 ° C., preferably 60 ° C., more preferably 80 ° C.
The “Tg temperature range” here refers to the temperature at which the Tg starts to shift from the low temperature side baseline when measured with a differential thermal analyzer (DSC) and the temperature converged to the high temperature side baseline. Point to the difference.
[0040]
The reason why the Tg of the polymer film of the present invention is higher than that of a polymer film containing no metal oxide is that the metal oxide surface and the polymer interacted with each other. That is, when the polymer film exceeds Tg, the mobility of polymer molecules in the film increases rapidly. However, when a metal oxide is present in the film, the metal oxide surface interacts with the polymer, and the polymer film In order to suppress molecular mobility, polymer mobility does not increase unless the temperature is raised to a higher temperature.
Tg can be measured, for example, by increasing the temperature of the polymer film at a predetermined rate of temperature increase (for example, 10 ° C./min) using differential thermal analysis (DSC). The increase in Tg is, for example, Tg (Tg of a polymer film containing a metal oxide).₁) And a metal film that does not contain a metal oxide Tg (Tg₂) Using a differential thermal analyzer (DSC), and Tg₁Value and Tg₂It can be obtained from the difference from the value.
[0041]
In addition, the Tg temperature range of the polymer film is increased for the same reason as the above Tg. In a polymer film not containing a metal oxide (preferably a metal oxide obtained by a sol-gel reaction), The Tg temperature range is small because the polymer molecules increase mobility at the same temperature almost simultaneously. In contrast, in a polymer film containing a metal oxide (preferably a metal oxide obtained by a sol-gel reaction), polymer molecules interacting with the surface of the metal oxide and polymer molecules not interacting with each other As a result, the temperature range where the mobility of polymer molecules increases is also wide. As a result, the Tg temperature range of the polymer film increases.
As described above, the variation width of Tg is the difference between the temperature at which Tg starts to shift from the low-temperature side baseline and the temperature converged on the high-temperature side baseline when measured with a differential thermal analyzer (DSC). Can be obtained from
[0042]
The polymer film of the present invention can have a heat distortion temperature higher by 2 ° C. or more than a polymer film containing no metal oxide, preferably 2 to 100 ° C., more preferably 5 to 100 ° C., 8 More preferably, it is higher by -100 ° C.
The “thermal deformation temperature” as used herein means a temperature at which the sample film starts to grow suddenly due to the load when a certain load is applied to the sample film to raise the temperature.
[0043]
In a polymer film not containing a metal oxide, particularly a film made of an amorphous polymer, when Tg is exceeded, elongation occurs rapidly due to an increase in molecular mobility. On the other hand, the polymer film containing the metal oxide of the present invention (preferably a metal oxide obtained by a sol-gel reaction) has no such elongation in the temperature range of several hundred degrees C. Does not occur. This is because if the above metal oxide is not contained in the polymer, the interaction between polymer molecules in the polymer film is weak, slip between molecules occurs, and elongation (deformation) is likely to occur due to heat and load. It is. On the other hand, when the above metal oxide is contained in the polymer, the surface of the metal oxide interacts with the polymer molecule, and this interaction force is greater than that between the polymer molecules. This is because such elongation (deformation) can be suppressed and the thermal deformation temperature can be increased.
For example, the thermal deformation temperature is measured by measuring the dimensional change of the sample as the temperature rises using TMA (Thermal Mechanical Analysis) under a predetermined condition, and an extrapolation line of elongation below Tg and extrapolation of elongation above Tg The heat distortion temperature can be obtained from the intersection with the line.
[0044]
[Production method of polymer film]
Next, the manufacturing method of the polymer film of this invention is demonstrated.
In the production method of the present invention, after casting or coating a mixture containing a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution, the mixture is heated stepwise or continuously. Thus, a film containing a metal oxide is obtained.
The production method of the present invention includes the following steps: (1) obtaining a mixture containing a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution; and (2) continuously or The process is divided into the step of obtaining a film containing a metal oxide by heating in stages.
[0045]
(1) A step of obtaining a mixture comprising a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution.
In the production method of the present invention, the metal oxide is obtained by a sol-gel reaction, that is, by hydrolyzing or hydrolyzing and polycondensing a metal alkoxide with an acid catalyst. This step is divided into the following modes depending on the type of polymer used.
[0046]
(1) In case of thermoplastic polymer
A polymer is dissolved in a solvent in advance to prepare a polymer solution, and a mixture in which the prepared polymer solution is mixed with a sol-gel reaction solution containing a metal alkoxide and an acid catalyst is obtained. The polymer concentration of the polymer solution is adjusted to 10 to 40% by mass, and after sufficiently mixed and dissolved at room temperature, the sol-gel reaction solution is added thereto. The mixing ratio of the polymer solution and the sol-gel reaction liquid is such that the content of the metal oxide obtained thereby after completion of the sol-gel reaction is 8 to 70% by mass, more preferably 20 to 60% by mass, and still more preferably 30 to 30%. It is made 55 mass%.
[0047]
Examples of the solvent for dissolving the polymer include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol and the like. The usage-amount of a solvent is 30-100 mass parts per 100 mass parts of total solid.
[0048]
It is preferable to put a silane coupling agent in the solvent. Examples of the silane coupling agent include a hydrocarbon group bonded to a silicon atom directly or through an oxygen atom or —OCO— group, and at least one of these hydrocarbon groups is a double bond, a halogen atom. Examples thereof include those having an atom, an epoxy group, an acid anhydride group, an alkoxycarbonyl group, an amino group, an acryloyl group, a methacryloyl group, an acrylamino group, a methacrylamino group, or a haloacylamino group. Among these, a silane coupling agent having an epoxy group or an amino group is particularly preferable. The mixing ratio of the silane coupling agent is 0.1 to 10 parts by mass, preferably 1 to 5 parts by mass with respect to 100 parts by mass of the polymer.
[0049]
The mixed solution of the sol-gel reaction liquid and the polymer solution is preferably heat-treated at 50 to 200 ° C. or less, more preferably 55 to 190 ° C., and still more preferably 60 to 180 ° C. Details of the heat treatment in the sol-gel reaction will be described later.
[0050]
(2) In case of thermosetting polymer
In the case of a thermosetting polymer, the above sol-gel reaction solution is mixed with a monomer solution of the thermosetting polymer for polymerization. The content of the metal oxide obtained by the sol-gel reaction with respect to the polymer component obtained by polymerization is 8 to 70% by mass, more preferably 20 to 60% by mass, and further preferably 30 to 55% by mass. Adjusted. Subsequent steps are dissolved in a solvent in the same manner as the above thermoplastic polymer, and a silane coupling agent is added. However, the dissolution temperature is preferably room temperature to 80 ° C.
[0051]
(2) Step of obtaining a film containing a metal oxide by heating continuously or stepwise
In the production method of the present invention, the mixture containing the sol-gel reaction liquid in the polymer solution can be heat-treated stepwise or continuously to promote the sol-gel reaction. When the mixture is heated stepwise, the initial reaction step of obtaining the first film by casting or coating the mixture to form a film and heat-treating the film-like mixture; and the first film It is preferable to have a late reaction step of obtaining a film comprising a polymer containing a metal oxide by further heat treatment.
Here, the “first film” refers to a film made of a gelled metal oxide and a polymer obtained after an initial reaction step.
An outline of the production method of the present invention having the steps (1) and (2) described above is shown in FIG.
[0052]
The temperature of the initial reaction step and the temperature of the late reaction step in the sol-gel reaction are not particularly limited as long as at least the temperature of the late reaction step is higher than the temperature of the initial reaction step. For example, in the initial reaction step, the reaction is performed at a temperature of 40 to 115 ° C, more preferably 50 to 90 ° C, and even more preferably 60 to 85 ° C. The reaction can be carried out at a temperature, more preferably a temperature of 110 to 190 ° C., and even more preferably a temperature of 120 to 185 ° C., so that a temperature difference can be provided between the temperature of the initial reaction step and the temperature of the late reaction step.
[0053]
In general, the sol-gel reaction is carried out at a constant temperature of 100 to 200 ° C. In contrast, in the production method of the present invention, the sol-gel reaction is performed at a relatively low temperature (for example, less than 115 ° C.) in the initial reaction step, and is performed at a higher temperature than the initial reaction step in the late reaction step. Thus, by performing the heating in the sol-gel reaction stepwise, the interaction between the metal oxide obtained by the sol-gel reaction and the polymer can be further strengthened.
[0054]
The reason for the treatment at a relatively low temperature in the initial reaction step is to slow down the reaction rate of the sol-gel reaction and to refine the metal oxide gel produced. Thereby, it is considered that a metal oxide gel having a large surface area is obtained and the metal oxide easily interacts with the polymer. In addition, since the reaction rate of the sol-gel reaction is slow, it is considered that a part (terminal) of the polymer is incorporated into the gel of the metal oxide and the interaction between the metal oxide and the polymer is further strengthened.
Therefore, compared to the case where the initial reaction step is processed at a high temperature (for example, 115 ° C. or higher), the size of the generated gel is not increased, and before the polymer diffuses into the metal oxide gel. Therefore, the interaction between the polymer and the metal oxide is not weakened.
[0055]
On the other hand, the reason why the treatment is performed at a high temperature (for example, 110 ° C. or more) in the late reaction step is to promote the sol-gel reaction further than in the initial reaction step. That is, by processing at a higher temperature than the initial reaction step, the gel density can be increased, and as a result, the gaps between the gels can be eliminated. Since the gelling gap is a main factor for increasing the thermal expansion coefficient, the thermal expansion coefficient can be decreased and the heat resistance can be improved by passing through the late reaction step.
When the initial reaction step is omitted and only the high temperature treatment in the late reaction step is performed, a rapid density increase occurs, a large shrinkage stress occurs, cracks occur during the sol-gel reaction, and the thermal expansion coefficient It will be big.
As described above, the production method of the present invention can form a high-density layer without cracks by forming a fine gel once in the initial reaction step and then solidifying the gel in the late reaction step. The advantage is obtained.
[0056]
The production method of the present invention may further include one or more steps of heat treatment at a temperature of 40 to 200 ° C. between the initial reaction step and the late reaction step. Furthermore, in the production method of the present invention, a temperature difference can be provided between the two reaction steps by continuously raising the temperature from the temperature of the initial reaction step to the temperature of the late reaction step (that is, with a temperature gradient).
[0057]
The reaction times of the initial reaction step and the late reaction step are each preferably 3 to 60 minutes, more preferably 5 to 40 minutes, and further preferably 7 to 30 minutes. When the reaction time is 3 to 60 minutes, the sol-gel reaction can be favorably promoted stepwise.
[0058]
In the production method of the present invention, between the initial reaction step and the late reaction step, 5-30 kg / m, preferably 7-25 kg / m, more preferably, the first film obtained in the initial reaction step. It is preferable to have a tension adding step of applying a tension of 8 to 22 kg / m to obtain a second film.
The “second film” here is a film obtained by applying tension to the first film, and is a film in which the interaction between the metal oxide and the polymer is strengthened. The reason is that fine cracks can be made in the initial metal oxide gel produced in the initial reaction step by applying the tension to the first film. This is because the polymer enters the crack, and the interaction between the metal oxide and the polymer can be further strengthened.
[0059]
The heat treatment in the late reaction step after the tension application step promotes the sol-gel reaction and advances the gelation, so that the polymer can be fixed in a state where the polymer is confined in the fine cracks of the gel. Can be made stronger than the second film.
The direction in which the tension is applied is not particularly limited, but is preferably parallel or perpendicular to the transport direction of the polymer film.
The outline of the process of the manufacturing method of the present invention described above is shown in FIG.
[0060]
Furthermore, in the production method of the present invention, in the initial reaction step, 0.5 to 100 ° C., preferably 2 to 40, between one surface (front surface) and the other surface (back surface) of the film-like mixture. It is preferable to provide a temperature difference of ° C, more preferably 3 to 30 ° C, and still more preferably 3 to 20 ° C.
By providing a temperature difference between the front and back surfaces of the film-like mixture, a concentration gradient of the metal oxide can be provided in the thickness direction of the film-like mixture. That is, the sol-gel reaction is more likely to proceed on the high temperature side of the film-like mixture than on the low temperature side, and unreacted components diffuse from the low temperature side. For this reason, the concentration of the metal oxide on the high temperature side can be increased. When the metal oxide concentration is increased, the thermal expansion coefficient is decreased, and a film having higher heat resistance (the transparent conductive layer is not easily broken due to a difference in thermal expansion even at a high temperature) is obtained. On the other hand, even if the metal oxide concentration is increased over the entire thickness direction of the film-like mixture, the coefficient of thermal expansion can be similarly reduced, but the overall metal oxide concentration becomes too high and a fragile film tends to be formed.
[0061]
In the production method of the present invention, in order to avoid the brittleness of the film, it is preferable to increase the metal oxide concentration on the surface on the conductive layer side to reduce the coefficient of thermal expansion, and to treat the surface side at a high temperature. It is preferable to treat the back side at a low temperature so that the total metal oxide concentration is not increased.
[0062]
The temperature gradient on the front and back surfaces of the film-like mixture in such an initial reaction step can be performed by casting on a substrate having a temperature control mechanism. That is, it can be performed by installing a panel heater or an infrared heater under the substrate or passing a fluid controlled to a predetermined temperature.
[0063]
Next, the film forming method of the film in the manufacturing method of the present invention will be described.
In the production method of the present invention, film formation can be carried out in the following manner depending on the type of polymer used.
(A) In case of thermoplastic polymer
The mixed reaction solution of the sol-gel reaction solution and the polymer solution prepared as described above is filtered and defoamed according to a conventional method. This is cast on a mirror-polished support (band or drum) from between slits adjusted to have a predetermined thickness. The sol-gel reaction is advanced while raising the temperature in the initial reaction step and the late reaction step described above. All of the temperature increases by such multiple steps may be performed on the support. Alternatively, the low temperature reaction in the initial reaction step may be performed on the support, and the high temperature reaction in the late reaction step may be performed after peeling off the support. Good. The latter is more preferable.
[0064]
(B) In case of thermosetting polymer
The same as the above-mentioned thermoplastic polymer. However, in the case of a thermosetting polymer, it is preferable to provide a temperature difference between the front and back surfaces of the first film as described above during the initial reaction step. The curing reaction of the thermosetting polymer may be carried out in any of the above reaction steps, but is preferably carried out after the low temperature reaction in the initial reaction step and before the high temperature reaction in the late reaction step. In the case of the photocurable type, this can be achieved by using an ultraviolet lamp during these steps. In the case of the thermosetting type, it is preferable to cure using the drying heat in the late reaction step.
[0065]
The thickness of the polymer film of the present invention is preferably 70 to 200 μm, more preferably 80 to 180 μm, and more preferably 90 to 150 μm, regardless of whether the thermosetting polymer or the thermoplastic polymer is used. More preferably. In any case, the haze is preferably 3% or less, more preferably 2% or less, and preferably 1% or less.
[0066]
The light transmittance of the polymer film of the present invention is preferably a transparent film, that is, 90% or more, and 92% or more since the substrate film of the present invention is used as an image display element such as a display. Is preferable, and it is further more preferable that it is 93% or more.
[0067]
Next, the conductive substrate of the present invention will be described.
[Conductive substrate]
The conductive substrate of the present invention has a conductive layer (E) on at least one surface of the film.
<Conductive layer (E)>
In the conductive substrate of the present invention, a known metal film, metal oxide film, or the like can be applied as the conductive layer. Among these, it is preferable to use a metal oxide film from the viewpoint of transparency, conductivity, and mechanical properties. For example, metal oxide films such as indium oxide, cadmium oxide and tin oxide to which tin, tellurium, cadmium, molybdenum, tungsten, fluorine, zinc, germanium and the like are added as impurities, zinc oxide and titanium oxide to which aluminum is added as impurities, Can be mentioned. Among them, a thin film of indium oxide mainly containing tin oxide and containing 2 to 15% by mass of zinc oxide is excellent in transparency and conductivity, and is preferably used.
[0068]
The surface resistance of the conductive layer (E) measured at 25 ° C. and 60% RH is preferably 1 to 500 Ω / sq, more preferably 1 to 200 Ω / sq, and 2 to 100 Ω / sq. More preferably, it is most preferable that it is 3-60 ohm / sq. When the surface resistance is in the range of 1 to 500 Ω / sq, for example, in the case of a liquid crystal display element, a display defect of the liquid crystal display element does not occur for a long time, and a highly reliable liquid crystal display element can be provided.
The surface resistance is obtained as a surface electrical resistance value using a predetermined device (for example, 8009 RESISTIVITY TEST FIXTURE made by KEITHLEY and 6517A type made by KEITHLEY, etc.) after conditioning in an environment of 25 ° C. and 60% RH. be able to.
[0069]
The film thickness of the conductive layer (E) is preferably 20 to 500 nm, and preferably 50 to 300 nm. If it is 20 nm or more, sufficient conductivity can be obtained, and the upper limit is not particularly limited, but is preferably 500 nm or less.
[0070]
Furthermore, the light transmittance of the conductive layer needs to be at least 80%, considering application to a transparent conductive substrate, preferably 83% or more, and preferably 85% or more. Further preferred. A light transmittance of 80% or more is preferable because the problem of reduced visibility does not occur.
[0071]
The conductive layer (E) is formed of at least one of the films of the present invention by a vapor deposition method in which a material is deposited from the vapor phase such as sputtering, vacuum deposition, ion plating, and plasma CVD. Made on the surface. Of these, the sputtering method is preferable from the viewpoint of obtaining excellent conductivity and transparency.
[0072]
The preferable degree of vacuum of such sputtering method, vacuum deposition method, ion plating method, and plasma CVD method is 1.33 mPa to 6.65 Pa (0.01 to 50 mTorr), and more preferably 6.65 mPa to 1.33 Pa. (0.05 to 10 mTorr).
Before providing the conductive layer (E), the base film is preferably subjected to surface treatment such as plasma treatment (reverse sputtering) or corona treatment. Moreover, you may heat up at the temperature of 50-200 degreeC while providing the conductive layer (E).
[0073]
The conductive layer (E) can be provided with an alignment film made of polyimide on the surface on the lamination side for the purpose of aligning the liquid crystal image element. Examples of the polyimide constituting the alignment film include those obtained by using polyamic acid and soluble polyimide as starting materials and curing them with heat or ultraviolet rays. The thickness of the alignment film is about 10 to 500 nm, preferably about 20 to 200 nm.
[0074]
<Gas barrier layer (B)>
In order to suppress gas permeability in the conductive substrate, it is preferable to further provide a gas barrier layer (B) in the conductive substrate of the present invention. The gas barrier layer (B) is, for example, a metal oxide mainly composed of one or more metals selected from the group consisting of silicon, aluminum, magnesium, zinc, zirconium, titanium, yttrium, and tantalum, silicon, aluminum , Boron metal nitrides or mixtures thereof. Among these, the main component is silicon oxide having a ratio of the number of oxygen atoms to the number of silicon atoms of 1.5 to 2.0 in terms of gas barrier properties, transparency, surface smoothness, flexibility, film stress, cost, and the like. It is preferable to use a metal oxide.
[0075]
The thickness of the gas barrier layer (B) is preferably 10 to 300 nm, and more preferably 30 to 200 nm. If the thickness of the gas barrier layer is 10 nm or more, sufficient gas barrier performance is obtained, and if it is 300 nm or less, transparency is also obtained, which is preferable.
[0076]
The gas barrier layer (B) may be provided on either the same side or the opposite side of the conductive layer (E), but is preferably provided on the opposite side of the conductive layer (E).
[0077]
The gas barrier layer (B) can be produced by a vapor deposition method in which a film is formed by depositing a material in a vapor phase, such as a sputtering method, a vacuum evaporation method, an ion plating method, or a plasma CVD method. Among these, the sputtering method is preferable from the viewpoint of obtaining particularly excellent gas barrier properties.
[0078]
The preferable vacuum degree of said sputtering method, vacuum evaporation method, ion plating method, and plasma CVD method is 1.33 mPa-6.65 Pa (0.01-50 mTorr), More preferably, 6.65 mPa-1.33 Pa ( 0.05 to 10 mTorr).
Before providing the gas barrier layer (B), it is preferable to subject the base film to a surface treatment such as plasma treatment (reverse sputtering) or corona treatment. Moreover, you may heat up to 50-200 degreeC during providing the transparent conductive layer.
[0079]
<Protective layer (D)>
The conductive laminated film of the present invention is preferably provided with a protective layer (D) for the purpose of preventing cracking of the conductive layer and obtaining solvent resistance of the base film.
The material for forming the protective layer is not particularly limited as long as it is generally used as a protective coating agent or a hard coating agent. Examples thereof include resins such as acrylic, melamine, alkyd, urethane, and other ultraviolet curable, thermosetting hard coat agents, and alicyclic structure-containing polymers. Among them, from the viewpoint of excellent transparency and heat resistance, and adhesion with an adjacent layer, preferably an acrylic or silicon hard coat agent, more preferably a curable acrylic hard coat agent, more preferably An ultraviolet curable acrylic hard coating agent, particularly preferably a polyfunctional acrylic ultraviolet curable hard coating agent, can be used as the protective layer forming material.
[0080]
As the acrylic ultraviolet hard coat agent, one containing a reactive monomer and / or a reactive oligomer and a photopolymerization initiator is used. Examples of reactive monomers include monofunctional acrylate monomers such as cyclohexyl acrylate, cyclohexyl methacrylate, glycidyl methacrylate, isobornyl methacrylate, and other higher alkyl acrylates; ethylene glycol, diethylene glycol, tripropylene glycol, butylene glycol, tetramethylolpropane, Examples thereof include multi-acrylate monomers in which two or more acrylates are bonded to polyols such as trimethylolpropane and pentaerythritol. Among these, 1 to 6 functional acrylates are preferable, 2 or 3 functional acrylates are more preferable, and alicyclic structure-containing acrylates are more preferable.
[0081]
Examples of the reactive oligomer include polyester acrylate having an acryloyl group at the terminal, epoxy acrylate or polyurethane acrylate having an epoxy group in the molecular chain and an acryloyl group at the terminal, an unsaturated polyester having a double bond in the molecular chain, Examples include 1,2-polybutazine and other oligomers having an epoxy group.
[0082]
Examples of the photopolymerization initiator include acetophenones such as 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and chlorinated acetophenone; benzophenones; benzyl, methyl orthobenzoylbenzoate, benzoylalkyl Benzoin ethers such as ether; azo compounds such as α, α′-azoisobutylnitrile, 2,2′-azobispropane and hydrazone; organic peroxides such as benzoyl peroxide and ditertiary butyl peroxide; diphenyl sulfide, Examples thereof include diphenyl disulfides such as dibenzoyl sulfite.
[0083]
As the acrylic hard coat agent, for example, an acrylic resin having a Tg of 5 to 110 ° C., a molecular weight of 1 to 100,000, and an acid value of 0.5 to 4 is preferably used, and further includes a silane coupling agent. . When Tg exceeds 110 ° C., the resin is hard, the varnish is easily peeled, the coating suitability is extremely poor, and the adhesion between the coated surface and the conductive layer (E) is reduced. On the other hand, when Tg is less than 5 ° C., blocking becomes very easy, and when there is a heating step in the subsequent step, the acrylic resin may flow, and in that case, a considerably large dimensional change occurs.
[0084]
The molecular weight of the acrylic resin is 1 to 100,000, preferably 40 to 70,000. When the molecular weight is less than 10,000, the solvent resistance of the protective layer (D) is inferior, and when it exceeds 100,000, the acrylic resin is difficult to dissolve in a general-purpose solvent, and further, the suitability for varnishing is poor and gelation tends to occur. It is preferable that an acid value is 1-4. If the acid value is less than 1, the solvent resistance is inferior, and if it exceeds 4, the hydrolysis may occur.
[0085]
It is more preferable to add a silane coupling agent to the protective layer (D) for improving adhesion. The silane coupling agent has a hydrocarbon group bonded directly to a silicon atom or through an oxygen atom or —OCO— group, and at least one of these hydrocarbon groups is a double bond, a halogen atom, Examples thereof include an epoxy group, an acid anhydride group, an alkoxycarbonyl group, an amino group, an acryloyl group, a methacryloyl group, an acrylamino group, a methacrylamino group, or a haloacylamino group. Of these, compounds having an epoxy group or an amino group are particularly preferred. The mixing ratio of the resin and the silane coupling agent is 0.1 to 10 parts by mass, preferably 1 to 5 parts by mass of the silane coupling agent with respect to 100 parts by weight of the resin.
[0086]
Examples of the method for laminating the protective layer (D) include gravure coating, reverse coating, kiss coating, spin coating, wire bar coating, roll coating, knife coating, etc., but the laminating method of the present invention is particularly limited. Is not to be done. After the application and drying of the protective layer (D), curing occurs in a short time by irradiating ultraviolet rays from a light source that generates ultraviolet rays such as a high-pressure mercury lamp, and the protective layer (D) is formed.
[0087]
The thickness of the said protective layer (D) can be suitably selected from the range of 0.01-10 micrometers, and it is preferable that it is 0.1-4 micrometers. If the thickness of the protective layer (D) is 0.01 μm or more, sufficient adhesion is obtained, and if it is 10 μm or less, the transparency does not deteriorate, which is preferable.
[0088]
The protective layer (D) may further contain an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, an antiblocking agent and the like as appropriate. When such an additive is added, the addition amount is within 10% by mass with respect to the mass of the acrylic resin.
The protective layer (D) to be formed may be double laminated or multiple laminated as long as the necessary function of the finally obtained layer is obtained, and different types of acrylics with different types of silane coupling agents added. A resin may be laminated.
[0089]
[Layer structure]
The substrate of the present invention has the conductive layer (E) on at least one surface of the film as described above. Furthermore, the board | substrate of this invention can also have a gas barrier layer (B) and a protective layer (D). In addition, the anchor layer (undercoat layer) (for example, curing of urethane resin or the like) is used for the purpose of enhancing the adhesion between the film and the layer thereon or the adhesion of each layer within the range not deteriorating the effect of the present invention. (Resin layer) can also be provided.
[0090]
As a preferable configuration of the substrate of the present invention, a film (S), a gas barrier layer (B), a protective layer (D), and a conductive layer (E) are formed as follows: conductive layer (E) / film (S) / gas barrier layer (B) / The aspect which has in order of a protective layer (D) is mentioned.
[0091]
The conductive substrate of the present invention has a Tg of 160 ° C. or higher, preferably 180 to 400 ° C., and more preferably 200 to 350 ° C. The light transmittance of the conductive substrate of the present invention is 80% or more, preferably 85% or more, and more preferably 90% or more.
The gas barrier performance of the conductive substrate of the present invention is such that the water vapor transmission rate measured at 40 ° C. and 90% RH is 0.01 to 5 g / m.²· Day · atm is preferred, 0.03 to 3 g / m²More preferably day · atm, 0.05-2 g / m²More preferably, it is day · atm. The oxygen permeability measured at 40 ° C. and 90% RH is 0.01 to 1 ml / m.²-Day, 0.01-0.7 ml / m²-Day is preferable, 0.01-0.5 ml / m²-More preferably, it is day. The gas barrier performance can be measured by, for example, the MOCON method.
[0092]
[Image display element]
Although the use of the film and conductive substrate of the present invention is not particularly limited, it can be suitably used as a transparent electrode substrate of an image display element because of excellent optical characteristics and mechanical characteristics. The term “image display element” as used herein means a circularly polarizing plate / liquid crystal display element, a touch panel, an organic EL element, or the like.
[0093]
<Circularly polarizing plate>
A circularly polarizing plate can be prepared by laminating a λ / 4 plate and a polarizing plate on the conductive substrate of the present invention. In this case, the lamination is performed so that the slow axis of λ / 4 and the absorption axis of the polarizing plate are 45−. As such a polarizing plate, one that is stretched in the 45-direction with respect to the longitudinal direction (MD) is preferably used. For example, those described in JP-A-2002-865554 can be suitably used.
[0094]
<Liquid crystal display element>
The reflective liquid crystal display device has a configuration including a lower substrate, a reflective electrode, a lower alignment film, a liquid crystal layer, an upper alignment film, a transparent electrode, an upper substrate, a λ / 4 plate, and a polarizing film in order from the bottom. The substrate of the present invention can be used as the transparent electrode and the upper substrate. In the case of color display, it is preferable to further provide a color filter layer between the reflective electrode and the lower alignment film, or between the upper alignment film and the transparent electrode.
The transmissive liquid crystal display device includes a backlight, a polarizing plate, a λ / 4 plate, a lower transparent electrode, a lower alignment film, a liquid crystal layer, an upper alignment film, an upper transparent electrode, an upper substrate, a λ / 4 plate, and a polarization in order from the bottom. It has a structure consisting of a film. Of these, the substrate of the present invention can be used as the upper transparent electrode and the upper substrate. In the case of color display, it is preferable to further provide a color filter layer between the lower transparent electrode and the lower alignment film, or between the upper alignment film and the transparent electrode.
The liquid crystal cell is not particularly limited, but more preferably, a TN (Twisted Nematic) type, an STN (Super Twisted Nematic) type, a HAN (Hybrid Aligned Nematic) type, a VA (Vertical Aligned) type, an EC type, a Bc type, an EC type, a Bc type, an EC type, a Bc type. It is preferably a type (Optically Compensatory Bend) or a CPA type (Continuous Pinwheel Alignment).
[0095]
<Touch panel>
The touch panel can be applied to those described in JP-A-5-127822, JP-A-2002-48913, and the like.
[0096]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples of the present invention. In addition, the material, usage-amount, ratio, processing content, processing procedure, etc. which are shown in the following Examples can be changed suitably unless it deviates from the meaning of this invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.
In the examples, parts and% are based on mass unless otherwise specified. Various measurements in the examples were performed as follows.
[0097]
[Measurement method]
1.Measurement of glass transition temperature (Tg) and Tg temperature range
Measurement is performed using a differential thermal analyzer (DSC) under the following conditions.
Sample amount: 20mg
Temperature increase rate: 10 ° C / min
Measurement temperature range: 30-300 ° C
Since the specific heat changes discontinuously at Tg, it changes with a low temperature side baseline, a transient region (a region where the low temperature side baseline and the high temperature side baseline change linearly), and a high temperature side baseline. Thus, Tg and Tg temperature range are obtained.
Tg: Temperature at the intersection of the low-temperature base line and a straight line extrapolating the transient region
Tg temperature width: difference between the temperature of the intersection of the straight line extrapolating the low temperature side baseline and the transient region and the temperature of the intersection of the straight line extrapolating the transient region and the high temperature side baseline
[0098]
2.Measurement of thermal deformation temperature, thermal expansion coefficient, thermal hysteresis
(1) TMA (Thermal Mechanical Analysis) measurement is performed under the following conditions. That is, the dimensional change of the sample accompanying the temperature rise is measured.
Sample width: 3mm
Between chucks: 25.4 mm
Temperature increase rate: 3 ° C / min
Measurement temperature range: 30-200 ° C
(2) The thermal deformation temperature and the thermal expansion coefficient are determined by the following method.
(1) Thermal deformation temperature: Elongation occurs as the temperature rises, but the elongation increases rapidly from the vicinity of Tg. The intersection of the extrapolated line extending below Tg and the extrapolated line extending beyond Tg is defined as the thermal deformation temperature (° C.).
{Circle around (2)} Thermal expansion coefficient: Obtained from the dimensional change of thermal expansion below Tg (ratio to the length between chucks: ppm) and the gradient of temperature (° C.) (ppm / ° C.).
(3) The thermal hysteresis is raised between 25 ° C. and 20 ° C. lower than the thermal deformation temperature at 3 ° C./min between the sample width and the chuck, and then immediately lowered to 25 ° C. at −3 ° C./min. Obtain the dimensional change at the start and end points.
[0099]
3.Measurement of surface resistance
(1) Initial surface resistance measurement
After adjusting the humidity to 25 ° C. and 60% RH for 3 hours or more, the initial resistance (R) is obtained using KEITHLEY's 8009 RESISTIVITY TEST FIXTURE and KEITHLEY's 6517A type.₀)It was measured.
(2) Measurement of surface resistance after heat treatment
The sample was hung under no tension using an air thermostat and heated at 175 ° C. for 30 minutes. After adjusting the humidity to 25 ° C. and 60% RH for 3 hours or more, the surface resistance (R₁₇₅) Was measured.
(3) Measurement of surface resistance change rate
(R₁₇₅) And (R₀) Is the absolute value of the difference (R₀The surface resistance change rate (%) was obtained by dividing by ().
[0100]
Example 1
1.Production of base film
(1) Preparation of thermoplastic resin solution
The following polymer was dissolved in methylene chloride so as to be 20% by mass.
▲ 1 ▼ MPC-1
Polycarbonate copolymer in which bisphenol A (BisA) and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (BCF) are mixed at BisA / BCF = 1/1 (molar ratio) (Tg: 225 ° C. ).
(2) MPC-2
Polycarbonate copolymer in which BisA, bisphenol A and 3,3,5-trimethyl-1,1-di (4-phenol) cyclohexylidene (IP) are mixed at BisA / IP = 2/3 (molar ratio) (Tg : 205 ° C).
(3) PES (Polyethersulfone)
Sumitomo Bakelite Sumilite FS-1300 (Tg: 220 ° C.).
(4) COC (cycloolefin copolymer)
Polynorbornene (Arton manufactured by Jiesal Co., Ltd., Tg: 160 ° C.).
[0101]
(2) Preparation of prepolymer solution of thermosetting resin
100 parts by mass of the following prepolymer, 300 parts by mass of 1-methoxy-2-propanol, 2 parts by mass of 1-hydroxycyclohexyl phenyl ketone as an initiator, and a silane coupling agent (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part by mass was mixed.
(1) EpAc
Epoxy acrylate prepolymer having a molecular weight of about 1040 (VR-60, Showa Polymer Co., Ltd.)
▲ 2 ▼ Ac
Acrylic resin (acrylic with a glass transition point of 105 ° C., a molecular weight of 67,000, and an acid value of 2 (Mitsubishi Rayon Co., Ltd. LR-1065))
(3) DCPA
Dimethylol tricyclodecane diacrylate (“Light acrylate DCP-A” manufactured by Kyoeisha Chemical Co., Ltd.)
▲ 4 ▼ UA
Urethane acrylate (Shin Nakamura Chemical "NK Oligo U-15HA")
▲ 5 ▼ PhR
Phenoxy resin ("PAPHEN" manufactured by Phenoxy Associates)
▲ 6 ▼ PI
Polyisocyanate ("Coronate" manufactured by Nippon Polyurethane Industry)
[0102]
(3) Preparation of casting dope
After the preparation of the thermoplastic resin solution and the preparation of the prepolymer solution of the thermosetting resin, the following sol-gel solution was added. The metal oxide content (mass ratio of the metal oxide after the sol-gel reaction to the polymer) is shown in Table 1.
(1) Silica-based sol-gel solution (Si-based)
After adding 88 parts by mass of acetic acid to a mixed solvent of 1800 parts by mass of 2-propanol, 640 parts by mass of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and 3-aminopropyltrimethoxysilane (ECHETMOS) 154 Each part by mass was mixed.
(2) Alumina-based sol-gel solution (Al-based)
Aluminum isopropoxide (manufactured by Wako Pure Chemical Industries, Ltd., solid content 40% by mass) and n-propyl alcohol were mixed, 10 mol / L hydrochloric acid was added dropwise, and N, N-dimethylbenzylamine was added after completion of the addition. Thereafter, a solution of 15 parts by mass of aluminum isopropoxide was obtained.
▲ 3 ▼ Silica Alumina (SiAl)
After dissolving TEOS (tetraethoxysilane) 80% by mass, aminopropyltriethoxysilane 10% by mass, glycidylpropyltriethoxysilane 5% by mass and methylpropylacrylethoxysilane 5% by mass in n-propyl alcohol, 2 mol / L Hydrochloric acid was added dropwise.
[0103]
(4) Film formation
The above mixture was cast on a stainless steel band by a die coating method. The mixture was heated on the band to allow initial reaction. Table 1 shows the reaction temperature and reaction time on the front and back surfaces of the film-like mixture at this time. Such a temperature difference between the front and back surfaces was implemented by providing a heater below the stainless steel band.
Next, the first film was peeled off from the band, and a late reaction was carried out while being rolled in the casing. The reaction temperature and reaction time at this time are shown in Table 1. Then, after drying until the residual solvent concentration became 0.08% by mass, both ends were trimmed, knurled, and wound up. The thickness of the base film thus obtained is shown in Table 1. In the present invention, each film was formed with a width of 1.5 m and a length of 3000 m.
The Tg, Tg temperature range, thermal deformation temperature, and thermal expansion coefficient of the base film thus obtained were measured by the methods described above. The results are shown in Table 1.
[0104]
Furthermore, the obtained base film was immersed in NMP at 25 ° C. for 10 minutes, and the solvent resistance was examined. After immersion, the increase in haze accompanying whitening was measured by the following method. The results are shown in Table 1.
[Solvent resistance evaluation method]
Measure haze before immersion (Hb)
Measure haze after immersion (assumed Ha)
Hb / Ha is solvent resistant
(The closer to 1, the better the solvent resistance, the smaller the value, the lower the solvent resistance)
[0105]
All the base films of the present invention exhibited good transparency with a haze of 1% or less and a light transmittance of 90% or more.
[0106]
[Table 1]

[0107]
From Table 1, the films of the present invention all had a coefficient of thermal expansion lower by 10 ppm / ° C. or more than that of the comparative example (reduction amount was 10 ppm / ° C. or more). Moreover, both Tg and Tg temperature widths were higher by 2 ° C. or more (temperature increase was 2 ° C. or more). From this, it was found that the polymer film of the present invention has improved heat resistance and can be suitably used as a substrate for transparent electrodes. Furthermore, the polymer films of the present invention all had good solvent resistance. From this, the film of the present invention exhibits a good solvent resistance even without the solvent resistant layer formed by the gas barrier film so far, so that the simple layer structure described below can be realized. I understand. Moreover, if the manufacturing method of this invention is used, compared with the film (each comparative example) produced without using the manufacturing method of this invention, Tg, Tg temperature range, thermal deformation temperature, thermal expansion coefficient, solvent resistance And the value of thermal hysteresis was good.
Furthermore, even if the polymer film contains a metal oxide, the polymer film (base film-43) produced without using the production method of the present invention is a polymer film containing no metal oxide (base film- 25) and the physical property value were comparable. From this, it can be seen that the heat resistance is improved not only in the polymer film containing the metal oxide but in the polymer film containing the metal oxide obtained by the production method of the present invention.
Furthermore, even if the base film 44 containing no metal oxide is treated under the temperature and tension conditions of the present invention, the base film 1 contains the metal oxide and is treated under the temperature and tension conditions of the present invention. In comparison, the temperature rise of Tg, the temperature range of Tg, the rise of heat distortion temperature, the decrease of the thermal expansion coefficient, and the improvement of the solvent resistance were extremely small and all were outside the scope of the present invention. Similarly, a base film 45 containing a metal oxide but not treated under the temperature and tension conditions of the present invention contains a metal oxide and treated under the temperature and tension conditions of the present invention. Compared to 1, the Tg temperature rise, the Tg temperature range, the heat distortion temperature rise, the thermal expansion coefficient reduction, and the solvent resistance improvement were extremely small and did not fall within the scope of the present invention. This is the same even when a thermosetting resin is used, and it is clear if the base film 18 and the base films 46 and 47 are compared.
[0108]
(Example 2)
1.Formation of gas barrier layer
On the undercoat layer on one side of the base film obtained in Example 1, one of the following barrier layers was selected (described in Table 1), and a substrate having a thickness shown in Table 2 was obtained.
(1) SiO₂Layer (SiO layer)
Si0 by the DC magnetron sputtering method.₂Was sputtered at an output of 5 kW in an Ar atmosphere under a vacuum of 0.665 mPa (5 mTorr).
(2) SiOxNy layer (SiN layer)
By RF magnetron sputtering, Si was used as a target, and O2 and N2 were introduced, and a film was formed at an output of 5 kW under a vacuum of 0.665 mPa (5 mTorr)._xN_yA film (x = 1, y = 1) was obtained.
[0109]
2.Formation of conductive layer
While heating the substrate film to 100 ° C., ITO (In₂O₃  95wt%, Sn0₂  A transparent conductive layer made of an ITO film having a thickness of 140 nm and an output of 5 kW in an Ar atmosphere under a vacuum of 0.665 mPa (5 mTorr) using a DC magnetron sputtering method with a target of 5 wt%) as an undercoat on the opposite side of the barrier layer Provided on the layer. This thickness is shown in Table 2.
[0110]
3.Formation of protective layer
On the barrier layer, a coating solution having the following formulation was stirred and dissolved at room temperature, then applied to a thickness of 3 μm (after drying) with a bar coater, heated at 80 ° C. for 10 minutes, and then irradiated with ultraviolet rays. Was irradiated.
100 parts by mass of acrylic resin
(Tg: 105 ° C., molecular weight: 67,000, acid value: 2 acrylic (Mitsubishi Rayon LR-1065))
Silane coupling agent 1 part by mass
(KBM-573 manufactured by Shin-Etsu Chemical Co., Ltd .; N-phenyl-γ-aminopropyltrimethoxysilane)
400 parts by weight of butyl acetate
[0111]
4).Evaluation
The surface resistance of the substrate thus obtained was measured by the above method. Furthermore, the water vapor transmission rate and the oxygen transmission rate were measured according to the following methods. The results are shown in Table 2 (fresh properties in Table 2). Further, these substrates were exposed to 180 ° C. (alignment film formation temperature) for 3 hours, and these were measured. The results are shown in Table 2 (post-thermo properties in Table 2).
[0112]
(1) Water vapor permeability
Using a Permantlan W1A manufactured by MOCON, measurement was performed for 24 hours in an atmosphere of 40 ° C. and 90% RH, and water vapor permeability was measured.
(2) Oxygen permeability
Using an OX-TRAN 10 / 50A manufactured by MOCON, measurement was performed in an atmosphere of 40 ° C. and 90% RH for 24 hours, and oxygen permeability was measured.
[0113]
[Table 2]

[0114]
From Table 2, all of the conductive substrates of the present invention showed good gas barrier performance in both water vapor transmission rate and oxygen transmission rate. This shows that the conductive substrate of the present invention has excellent gas barrier properties. Further, the conductive substrate of the present invention hardly increased the surface electrical resistance after the heat treatment. This shows that the conductive substrate of the present invention can maintain good conductivity even after the heat treatment.
On the other hand, when the production method of the present invention was used, both the gas barrier property and the surface resistance were good as compared with the film produced without using the production method of the present invention (base film-41). Moreover, the film (base film-41) produced without using the production method of the present invention had the same physical property value as the film not containing the metal oxide (base film-25). From this, it can be seen that the film obtained by the production method of the present invention maintains excellent gas barrier properties and conductivity.
In addition, the thermosetting resin used had a small thermal hysteresis and a low black spot failure rate after repeating the thermotest three times, which was even better.
Furthermore, even if the base film 44 containing no metal oxide is treated under the temperature and tension conditions of the present invention, the base film 1 contains the metal oxide and is treated under the temperature and tension conditions of the present invention. In comparison, the surface resistance and water vapor / oxygen permeability after thermostating were large, and black spots and color shift failures were likely to occur, and good results were not obtained.
Similarly, the base film 45 not containing the metal oxide and not treated under the temperature and tension conditions of the present invention contains the metal oxide and treated under the temperature and tension conditions of the present invention. Compared with film 1, the surface resistance after thermostat and water vapor / oxygen permeability were large, and black spots and color misregistration failures were likely to occur, and good results were not obtained. This is the same even when a thermosetting resin is used, and it is clear when the base film 18 and the base films 46 and 47 are compared.
[0115]
Example 3
1.Fabrication of circularly polarizing film
A λ / 4 plate described in JP-A-2000-826705 and JP-A-2002-131549 is laminated on the opposite side of the transparent conductive layer of the substrate of the present invention, and further, JP-A-2002-865554 is provided thereon. A circularly polarizing plate was prepared by laminating the polarizing plates described in 1. above. The angle between the transmission axis of the polarizing film and the slow axis of the λ / 4 plate was set to 45 °.
[0116]
2.Production of liquid crystal display devices
(1) Fabrication of TN liquid crystal display device
The multilayer film of the present invention, a transparent conductive (ITO) layer of a glass substrate provided with an aluminum reflective electrode having fine irregularities, and a polyimide alignment film (SE-7992, manufactured by Nissan Chemical Co., Ltd.) on the electrode side, respectively. Formed. Although heat treatment was carried out at 200 ° C. for 30 minutes, no increase in resistance value or increase in gas permeability was observed in the present invention. On the other hand, all the comparative examples increased more than twice.
This was rubbed, and two substrates (a glass substrate and a multilayer film) were stacked via a 1.7 μm spacer so that the alignment films face each other. The orientation of the substrate was adjusted so that the rubbing directions of the two alignment films intersected at an angle of 110 °. Liquid crystal (MLC-6252, manufactured by Merck) was injected into the gap between the substrates to form a liquid crystal layer. In this way, a TN liquid crystal cell having a twist angle of 70 ° and a Δnd value of 269 nm was produced.
A reflection type liquid crystal display device was prepared by laminating the λ / 4 plate and the polarizing plate on the opposite surface of the multilayer film to ITO. Good images were obtained using the substrate of the present invention. On the other hand, in the case of using the comparative example, a black spot failure (a fine black dot is not displayed on the image layer portion and an image is not displayed) due to a decrease in gas barrier properties and a color shift due to a crack in the conductive layer occurred.
[0117]
3.Production of STN liquid crystal display device
A polyimide alignment film (SE-7992, manufactured by Nissan Chemical Industries, Ltd.) was formed on the transparent conductive (ITO) layer side of the glass substrate on which the substrate of the present invention and the ITO layer were laminated. Although heat treatment was performed at 200 ° C. for 30 minutes, no increase in resistance value or increase in gas permeability was observed in the present invention. On the other hand, all the comparative examples increased more than twice.
The two substrates were stacked with a 6.0 μm spacer so that the alignment films face each other. The orientation of the substrate was adjusted so that the rubbing directions of the two alignment films intersected at an angle of 60 °. Liquid crystal (ZLI-2777, manufactured by Merck & Co., Inc.) was injected into the gap between the substrates to form a liquid crystal layer. Thus, an STN type liquid crystal cell having a twist angle of 240 ° and a Δnd value of 791 nm was produced.
The λ / 4 plate and the polarizing plate were laminated on the glass substrate side of the liquid crystal cell, and a light guide plate and a light source were placed thereunder. The λ / 4 plate and the polarizing plate were laminated on the multilayer film side to obtain a transmissive liquid crystal display device. Good images were obtained using the multilayer film of the present invention. On the other hand, as shown in Table 2, the one using the comparative example is caused by a black spot failure (a fine black dot is not displayed on the image layer part and an image is not displayed) due to a decrease in gas barrier property or a crack of the conductive layer. In addition, the color misregistration occurred. These occurrence rates are obtained by visually confirming the areas of these generated areas when the liquid crystal display substrate is assembled and displaying the entire surface in white, and expressed as a ratio to the total display area.
[0118]
4).Touch panel production
The touch panel was created according to the description in JP-A-5-127822, JP-A-2002-48913, and the like. The thing of this invention showed favorable performance, and the said failure did not generate | occur | produce.
[0119]
5).Fabrication of organic EL elements
According to JP 2000-267097 A, the optical compensation film of the present invention is a protective tack (with an antireflection functional layer on the outermost surface) / the circularly polarizing plate (from the observer side to the organic EL side) ) / Organic EL element / reflection electrode. The thing of this invention showed favorable performance, and the said failure did not generate | occur | produce.
[0120]
【The invention's effect】
As described above, the film of the present invention contains a metal oxide having a relatively small coefficient of thermal expansion in a polymer having a relatively large coefficient of thermal expansion. Thereby, the conductive substrate using the film of the present invention can reduce the dimensional distortion due to the difference in thermal expansion coefficient between the base film and the conductive layer, so that the heat resistance is improved and good conductivity can be maintained.
[0121]
In the method for producing the film of the present invention, the metal oxide obtained by the sol-gel reaction is dispersed and contained in the polymer, and the sol-gel reaction is performed in a plurality of steps having temperature differences, preferably by applying tension. As a result, the production method of the present invention can improve the interaction between the polymer molecules and the metal oxide and suppress the mobility of the polymer compared with the case where the sol-gel reaction is not used. Even after forming the alignment film, good conductivity can be maintained.
[0122]
Furthermore, since the image display element of the present invention uses the above-mentioned film as a substrate for transparent electrodes, it can maintain excellent heat resistance and good conductivity.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view (No. 1) showing a production method of the present invention.
FIG. 2 is a schematic explanatory view (No. 2) showing the manufacturing method of the present invention.

Claims (8)

A polymer film containing a metal oxide, wherein the film has a coefficient of thermal expansion lower by 10 to 100 ppm / ° C than a film not containing the metal oxide. A polymer film containing a metal oxide, wherein the film has a heat distortion temperature of 2 to 100 ° C. higher than that of a film not containing the metal oxide. A polymer film containing a metal oxide, wherein the glass transition temperature of the film is 2 to 100 ° C. higher than that of the film not containing the metal oxide. A conductive substrate comprising a conductive layer on at least one surface of the polymer film according to claim 1. An image display element comprising the conductive substrate according to claim 4. A method for producing a polymer film by casting or coating a mixture containing a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution, wherein the mixture is cast or coated. A method for producing a polymer film, comprising heating a mixture stepwise or continuously to incorporate a metal oxide into the polymer film. A method for producing a polymer film, comprising casting or coating a mixture comprising a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution,
An initial reaction step in which a first film is obtained by casting or applying a mixture containing a sol-gel reaction solution containing a metal alkoxide and an acid catalyst in a monomer solution or a polymer solution to form a film, followed by heat treatment. When,
A tension applying step of applying a tension of 5 to 30 kg / m to the first film to obtain a second film, and a method for producing a polymer film. The method for producing a polymer film according to claim 7, further comprising a late reaction step of obtaining a polymer film containing a metal oxide by further heat-treating the second film.

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