JP4337379B2 - Display film made of cellulose ester - Google Patents

Description

【００６９】
【化２】

【００７０】
【化３】

【００７１】
【化４】

【００７２】
グリコレート系可塑剤は特に限定されないが、分子内に芳香環またはシクロアルキル環を有するグリコレート系可塑剤を好ましく用いることが出来る。好ましいグリコレート系可塑剤としては、例えばブチルフタリルブチルグリコレート、エチルフタリルエチルグリコレート、メチルフタリルエチルグリコレート等を用いることが出来る。
【００７３】
リン酸エステル系可塑剤では、トリフェニルホスフェート、トリクレジルホスフェート、クレジルジフェニルホスフェート、オクチルジフェニルホスフェート、ジフェニルビフェニルホスフェート、トリオクチルホスフェート、トリブチルホスフェート等、フタル酸エステル系可塑剤では、ジエチルフタレート、ジメトキシエチルフタレート、ジメチルフタレート、ジオクチルフタレート、ジブチルフタレート、ジ−２−エチルヘキシルフタレート、ジシクロヘキシルフタレート等を用いることが出来る。
【００７４】
これらの可塑剤は２種以上混合して用いることも出来る。
本発明のセルロースエステルフィルムには、必要に応じて紫外線吸収剤、染料、マット剤等の添加剤を添加してもよい。
【００７５】
紫外線吸収剤は、例えば、液晶表示装置を太陽光線等に曝されるような室外での液晶の劣化防止の観点から、波長３７０ｎｍ以下の紫外線の吸収能に優れ、かつ良好な液晶表示性の観点から、波長４００ｎｍ以上の可視光の吸収が少ないものが好ましく用いられる。本発明においては、特に波長３７０ｎｍでの透過率が１０％以下であることが好ましく、より好ましくは５％以下、更に好ましくは２％以下である。
【００７６】
本発明においては、分子内に芳香族環を２つ以上有する紫外線吸収剤が特に好ましく用いられる。
【００７７】
本発明に用いられる紫外線吸収剤は特に限定されないが、例えばオキシベンゾフェノン系化合物、ベンゾトリアゾール系化合物、サリチル酸エステル系化合物、ベンゾフェノン系化合物、シアノアクリレート系化合物、トリアジン系化合物、ニッケル錯塩系化合物、無機粉体等が挙げられる。好ましく用いられる紫外線吸収剤は、透明性が高く、偏光板や液晶素子の劣化を防ぐ効果に優れたベンゾトリアゾール系紫外線吸収剤やベンゾフェノン系紫外線吸収剤が好ましく、不要な着色がより少ないベンゾトリアゾール系紫外線吸収剤が特に好ましい。本発明に用いられる紫外線吸収剤の具体例として、例えば、５−クロロ−２−（３，５−ジ−ｓｅｃ−ブチル−２−ヒドロキシルフェニル）−２Ｈ−ベンゾトリアゾール、（２−２Ｈ−ベンゾトリアゾール−２−イル）−６−（直鎖及び側鎖ドデシル）−４−メチルフェノール、２−ヒドロキシ−４−ベンジルオキシベンゾフェノン、２，４−ベンジルオキシベンゾフェノンやチヌビン１０９、チヌビン１７１、チヌビン２３４、チヌビン３２６、ビン３２７、チヌビン３２８等のチヌビンは何れもチバ・スペシャルティ・ケミカルズ社製の市販品で、好ましく使用出来る。
【００７８】
紫外線吸収剤は２種以上の混合物であってもよい。
また、紫外線吸収剤としては高分子紫外線吸収剤も好ましく用いることが出来、特に特開平６−１４８４３０号記載のポリマータイプの紫外線吸収剤が好ましく用いられる。
【００７９】
紫外線吸収剤の添加方法は、アルコールやメチレンクロライド、ジオキソラン等の有機溶媒に紫外線吸収剤を溶解してからドープに添加するか、または直接ドープ組成中に添加してもよい。無機粉体のように有機溶剤に溶解しないものは、有機溶剤とセルロースエステル中にデゾルバーやサンドミルを使用し、分散してからドープに添加する。
【００８０】
紫外線吸収剤の使用量は、化合物の種類、使用条件等により一様ではないが、セルロースエステルフィルムの乾燥膜厚が３０〜２００μｍの場合は、余り多い場合は可塑剤としても作用するので、線膨張率の悪化しない範囲、即ち、前記可塑剤と同様１質量％未満が好ましい。
【００８１】
その他、酸化防止剤、色味調整のためのアンスラキノン系染料等を添加することも出来る。
【００８２】
酸化珪素等の微粒子マット剤、有機物によって表面処理された酸化珪素等のマット剤微粒子を加えてもよい。
微粒子の平均径が大きい方がマット効果は大きく、平均径の小さい方は透明性に優れるため、微粒子の一次粒子の平均径は５〜５０ｎｍが好ましく、更に好ましくは７〜２０ｎｍである。
【００８３】
酸化珪素の微粒子としては特に限定されないが、例えば日本アエロジル（株）製のＡＥＲＯＳＩＬ（アエロジル）２００、２００Ｖ、３００、Ｒ９７２、Ｒ９７２Ｖ、Ｒ９７２ＣＦ、Ｒ９７４、Ｒ２０２、Ｒ８０５、Ｒ８１２、ＯＸ５０、ＴＴ６００等が挙げられ、ＡＥＲＯＳＩＬ（アエロジル）２００、２００Ｖ、Ｒ９７２、Ｒ９７２Ｖ、Ｒ９７４、Ｒ２０２、Ｒ８０５、Ｒ８１２が好ましい。
【００８４】
各種添加剤はドープにバッチ添加してもよいし、添加剤溶解液を別途用意してインライン添加してもよい。特にマット剤は濾過材への負荷を減らすために、一部または全量をインライン添加することが好ましい。
【００８５】
添加剤溶解液をインライン添加する場合は、ドープとの混合性をよくするため、少量のセルロースエステルを溶解するのが好ましい。好ましいセルロースエステルの量は、溶剤１００質量部に対して１〜１０質量部で、より好ましくは、３〜５質量部である。
【００８６】
本発明においてインライン添加、混合を行うためには、例えば、スタチックミキサー（東レエンジニアリング製）、ＳＷＪ（東レ静止型管内混合器 Ｈｉ−Ｍｉｘｅｒ）等のインラインミキサー等が好ましく用いられる。
【００８７】
また、本発明に係わる前記積層フィルムにおけるセルロースエステルフィルムを主体とする透明支持体は、更に加水分解中縮合が可能な反応性金属化合物の重縮合物からなる金属酸化物微粒子を０〜２０質量％含有しているとさらに好ましい。
【００８８】
また、前記金属酸化物微粒子は、前記一般式（１）で表されるアルコキシシランの加水分解重縮合物であることが好ましい。
【００８９】
これら有機−無機ハイブリッドによるセルロースエステル樹脂を用いると本発明に係わるディスプレイ用フィルムはさらに好ましい特性を有する。
【００９０】
前記一般式（１）中、Ｒ′はアルキル基であり、Ｒは水素原子または１価の置換基を表し、ｎは３または４を表す。
【００９１】
Ｒ′で表されるアルキル基としてはメチル基、エチル基、プロピル基、ブチル基等の基があげられ、置換基を有していてもよく、置換基としてはアルコキシシランとしての性質を示すものであれば特に制限はなく、例えば、ハロゲン原子、アルコキシ基等により置換されていてもよいが、より好ましくは非置換のアルキル基であり、特にメチル基、エチル基が好ましい。
【００９２】
Ｒで表される１価の置換基としては、アルコキシシランとしての性質を示す化合物であればよく、具体的にはアルキル基、シクロアルキル基、アルケニル基、アリール基、芳香族複素環基、シリル基等があげられる。中でも好ましいのは、アルキル基、シクロアルキル基、アルケニル基である。また、これらはさらに置換されていてもよい。Ｒの置換基としては、フッ素原子、塩素原子等のハロゲン原子、アミノ基、エポキシ基、メルカプト基、ヒドロキシル基、アセトキシ基等特にアルコキシシランとしての性質を損なわない種々の置換基があげられる。
【００９３】
一般式（１）で表されるアルコキシシランの好ましい例として、具体的には、テトラメトキシシラン、テトラエトキシシラン（ＴＥＯＳ）、テトラｎ−プロポキシシラン、テトライソプロポキシシラン、テトラｎ−ブトキシシラン、テトラｔ−ブトキシシラン、テトラキス（メトキシエトキシ）シラン、テトラキス（メトキシプロポキシ）シラン、
また、メチルトリメトキシシラン、メチルトリエトキシシラン、エチルトリメトキシシラン、エチルトリエトキシシラン、ｎ−プロピルトリメトキシシラン、ｎ−プロピルトリエトキシシラン、ｎ−ブチルトリメトキシシラン、ｉ−ブチルトリメトキシシラン、ｎ−へキシルトリメトキシシラン、３−グリシドキシプロピルトリメトキシシラン、３−アミノプロピルトリエトキシシラン、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、３−クロロプロピルトリメトキシシラン、３−メルカプトプロピルトリメトキシシラン、アセトキシトリエトキシシラン、（ヘプタデカフルオロ−１，１，２，２−テトラヒドロデシル）トリメトキシシラン、（３，３，３−トリフルオロプロピル）トリメトキシシラン、（３，３，３−トリフルオロプロピル）トリメトキシシラン、ペンタフルオロフェニルプロピルトリメトキシシラン、
さらに、ビニルトリメトキシシラン、ビニルトリエトキシシラン、フェニルトリメトキシシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン等が挙げられる。
【００９４】
また、これらの化合物が部分的に縮合した、多摩化学製シリケート４０、シリケート４５、シリケート４８、Ｍシリケート５１のような数量体のケイ素化合物でもよい。
【００９５】
前記アルコキシシランは、加水分解重縮合が可能な珪素アルコキシド基を有しているため、これらのアルコキシシランを加水分解重縮合することによって、高分子化合物のネットワーク構造が形成され、該アルコキシシランまたは加水分解重縮合物をセルロースエステルと縮合させることによって、セルロースエステルからなる有機高分子成分とアルコキシシランの加水分解重縮合により形成される微粒子成分とが密な架橋構造を有する透明フィルムが得られる。
【００９６】
具体的には、疎水的なアルコキシシランに水、また有機金属化合物と水が混和しやすいように、メタノール、エタノール、アセトニトリルのような親水性の有機溶媒を共存させ、必要なら触媒を添加して、アルコキシシランを加水分解、重縮合させ、その加水分解重縮合物を、セルロースエステルのドープにを添加、混合することでセルロースエステルと縮合させる。
【００９７】
該透明フィルムを透明支持体として用いることで、セルロースエステルのもつ光学特性を失うことなしに、耐熱性の向上、また線膨張率が更に小さく、また前記バリア層と組み合わせることで透湿度がさらに改良され、高温、高湿条件下においても変形しにく、線膨張率の低い積層フィルムが得られる。
【００９８】
前記セルロースエステルおよび前記一般式（１）で表されるアルコキシシランの加水分解重縮合物からなる微粒子成分は、質量比率で、透明フィルム支持体の８０％以上をしめるのが好ましく、更に好ましくは９０％以上である。主たる成分以外にも後述するような可塑剤、マット剤などの添加剤が含まれていても良い。
【００９９】
また、主たる成分がセルロースエステルおよびアルコキシシランの加水分解中縮合物微粒子である透明フィルムにおいて用いられるセルロースエステルとしては、前記セルロースエステルであり、特にアセチルセルロースが好ましい。また、セルロースをアルコキシシリル基で就職したセルロースエステルも好ましく用いられ、アセチル基による置換度をＸ、アルコキシシリル基を有する官能基による置換度をＹとして表した場合に、下記の式（１）、（２）を満たすセルロースエステルであることが好ましい。
【０１００】
式（１） ０≦Ｙ≦１．５
式（２） １．０＜Ｘ＋Ｙ≦２．９
これはＸ＋Ｙが１．０以上２．９以下の範囲のものが樹脂の溶解性が高く、高濃度のドープ（溶媒に樹脂を溶かした溶解液を以後ドープと呼ぶ）を作製でき、製膜・乾燥時により有利だからである。また、アルコキシシランの加水分解重縮合物と縮合反応が出来るアルコキシシリル基で置換されていてもよい。しかし透明フィルムの網目構造が密となりすぎ、もろいフィルムとなってしまうことを避けるためには、Ｙは１．５以下が好ましい。
【０１０１】
これらアシル基の置換度の測定方法は前記の通りＡＳＴＭ−Ｄ８１７−９６に準じて測定することが出来る。
【０１０２】
これら複合フィルムに用いられるセルロース誘導体の原料のセルロースとしては、前記同様のものが用いられる。また、セルロース誘導体の数平均分子量を（Ｍｎ）、重量平均分子量を（Ｍｗ）としたときＭｗ／Ｍｎ比（分子量分布を示す）についても前記同様である。
【０１０３】
また透明フィルム中の有機金属化合物（アルコシキシラン加水分解重縮合物）の含有量としては、前記一般式（１）で表されるアルコキシシランの加水分解重縮合物を、加水分解重縮合が完全に終了した形態をとっていると仮定し下記一般式（２）で表した時、一般式（２）で表される無機高分子化合物の質量の総和が、前記の通り、透明フィルムの全質量に対して０〜２０質量％が好ましい。
【０１０４】
一般式（２） Ｒ_4-nＳｉＯ_n/2
式中、Ｒは水素原子または一価の置換基を表し、ｎは３または４である。ここにおいてＲは前記一般式（１）におけるものと同義である。
【０１０５】
透明フィルムが高温時に軟化しにくくするためには有機金属化合物の添加量が１質量％以上であり、また、透明フィルムの網目構造が密となりすぎ、もろいフィルムとなってしまうことを避けるには、有機金属化合物の添加量が透明フィルムの２０質量％以下である。
【０１０６】
〈加水分解触媒〉
本発明の透明フィルムにおいて、前記一般式（１）で表されるアルコキシシランは、必要に応じて水・触媒を加えて加水分解を起こさせて縮合反応を促進してもよい。
【０１０７】
しかしフィルムのヘイズ、平面性、製膜速度、溶剤リサイクルなどの生産性の観点から、水分はドープ濃度の０．０１質量％以上２．０質量％以下の範囲内とすることが好ましい。
【０１０８】
疎水的なアルコキシシランに水を添加する場合には、有機金属化合物と水が混和しやすいように、メタノール、エタノール、アセトニトリルのような親水性の有機溶媒が共存していることが好ましい。また、セルロースエステルのドープにアルコキシシランまたはその加水分解重縮合物を添加する際に、ドープからセルロースエステルが析出しないよう、該セルロースエステルの良溶媒も含まれていることが好ましい。
【０１０９】
ここで触媒としては、塩酸、硫酸、硝酸、りん酸、１２タングスト（VI）りん酸、１２モリブド（VI）りん酸、けいタングステン酸等の無機酸、酢酸、トリフロロ酢酸、レブリン酸、クエン酸、ｐ−トルエンスルホン酸、メタンスルホン酸等の有機酸等が用いられる。酸を添加しゾル・ゲル反応が進行した後に塩基を加え中和しても良い。塩基を加え中和する場合、乾燥工程前でのアルカリ金属の含有量が５０００ｐｐｍ未満である事が好ましい（ここでアルカリ金属とは、イオン状態のものを含む）。又、ルイス酸、例えばゲルマニウム、チタン、アルミニウム、アンチモン、錫などの金属の酢酸塩、その他の有機酸塩、ハロゲン化物、燐酸塩などを併用してもよい。
【０１１０】
また触媒として、このような酸類の代りに、アンモニア、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、ジエチルアミン、トリエチルアミンなど、ＤＢＵ（ジアザビシクロウンデセン−１）、ＤＢＮ（ジアザビシクロノネン）などのビシクロ環系アミン、アンモニア、ホスフィン、アルカリ金属アルコキシド、水酸化アンモニウム、水酸化テトラメチルアンモニウム、水酸化ベンジルトリメチルアンモニウム等の塩基を用いることができる。
【０１１１】
このような、酸またはアルカリ触媒の添加量としては特に制限はされないが、好ましくは重縮合可能な反応性金属化合物の量に対して質量で０．０１％〜２０％が好ましい。また、酸及び塩基の処理を複数回併用しても良い。触媒を中和してもよいし揮発性の触媒は減圧で除去してもよいし、分液水洗等により除去しても良い。触媒の除去が簡便である、イオン交換樹脂のような固体触媒を使用しても良い。
【０１１２】
なおアルコキシシランの加水分解重縮合は、塗布前の溶液状態で反応を完結させても良いし、フィルム状に流延してから反応を完結させても良いが塗布前に反応を完結させるのが良い。用途によっては反応は完全に終了しなくても良いが、できれば完結していたほうがよい。
【０１１３】
〈溶剤〉
本発明に係わる、セルロースエステルおよびアルコキシシランの加水分解重縮合物を主たる成分とするセルロース−シリカハイブリッドポリマーを主体とするフィルム（透明支持体）の製造は、前記セルロースエステルフィルムと同様に、例えばアセチルセルロースに、前記アルコキシシランから形成したアルコキシシランまたはその加水分解重縮合物を添加して共に溶剤に溶解しドープを形成して、これを流延用基材（ベルト状もしくはドラム状のステンレスを鏡面仕上げした支持体）上にドープ液を流延（キャスト工程）して製膜することが出来る。
【０１１４】
これらアセチルセルロースおよび前記アルコキシシランまたはその加水分解重縮合物を溶解する溶媒としては、アセチルセルロース同様、揮発性の溶媒が好ましく、かつ、触媒やアルコキシシラン等と反応せず、しかも流延用基材を溶解しないものが好ましい。またこのような溶媒を２種以上混合して用いて良い。また、セルロース−シリカハイブリッドポリマーの製造においては、セルロースエステルとアルコキシシランを各々別の溶媒に溶解した後に混合してもよい。
【０１１５】
この様に基本的にはセルロースエステルの成膜と同様に、セルロースエステルの溶解液（ドープ）にこれらのアルコキシシランまたはその加水分解重縮合物を添加してドープを作製することでセルロース−シリカハイブリッドポリマーの製造ができる。
【０１１６】
ここで、以下、上記セルロースエステルに対して良好な溶解性を有する有機溶媒を良溶媒といい、また溶解に主たる効果を示し、その中で大量に使用する有機溶媒を主（有機）溶媒または主たる（有機）溶媒という。
【０１１７】
良溶媒の例としてはアセトン、メチルエチルケトン、シクロペンタノン、シクロヘキサノンなどのケトン類、テトラヒドロフラン（ＴＨＦ）、１，４−ジオキサン、１，３−ジオキソラン、１，２−ジメトキシエタンなどのエーテル類、ぎ酸メチル、ぎ酸エチル、酢酸メチル、酢酸エチル、酢酸アミル、γ−ブチロラクトン等のエステル類の他、メチルセロソルブ、ジメチルイミダゾリノン、ジメチルホルムアミド、ジメチルアセトアミド、アセトニトリル、ジメチルスルフォキシド、スルホラン、ニトロエタン、塩化メチレンなどが挙げられるが、１，３−ジオキソラン、ＴＨＦ、メチルエチルケトン、アセトン、酢酸メチルおよび塩化メチレンが好ましい。
【０１１８】
ドープには、上記有機溶媒の他に、１〜４０質量％の炭素原子数１〜４のアルコールを含有させることが好ましい。これらは、ドープを金属支持体に流延した後、溶媒が蒸発し始めてアルコールの比率が多くなることでウェブ（支持体上にセルロース誘導体のドープを流延した以降のドープ膜の呼び方をウェブとする）をゲル化させ、ウェブを丈夫にし金属支持体から剥離することを容易にするゲル化溶媒として用いられたり、これらの割合が少ない時は非塩素系有機溶媒のセルロース誘導体の溶解を促進したりする役割もあるし、反応性金属化合物のゲル化、析出、粘度上昇を抑える役割もある。
【０１１９】
炭素原子数１〜４のアルコールとしては、メタノール、エタノール、ｎ−プロパノール、ｉｓｏ−プロパノール、ｎ−ブタノール、ｓｅｃ−ブタノール、ｔｅｒｔ−ブタノール、プロピレングリコールモノメチルエーテルを挙げることが出来る。これらのうち、ドープの安定性に優れ、沸点も比較的低く、乾燥性も良く、且つ毒性がないこと等からエタノールが好ましい。これらの有機溶媒は、単独ではセルロース誘導体に対して溶解性を有しておらず、貧溶媒という。
【０１２０】
このような条件を満たし好ましい高分子化合物であるセルロースエステル誘導体を高濃度に溶解する溶剤として最も好ましい溶剤は塩化メチレン：エチルアルコールの比が９５：５〜８０：２０の混合溶剤である。
【０１２１】
前記流延（キャスティング工程）はドープを加圧ダイに送液し、無限に移送する無端の金属ベルト或いは回転する金属ドラムの流延用支持体（以降、単に支持体ということもある）上に加圧ダイからドープを流延する工程である。流延用支持体表面は鏡面となっている。その他の流延方法としては流延されたドープ膜をブレードで膜厚を調節するドクターブレード法等もあるが、口金部分のスリット形状を調整でき、膜厚を均一にし易いコートハンガーダイやＴダイ等の加圧ダイが好ましい。
【０１２２】
ウェブ（流延用支持体上にドープを流延した以降のドープ膜の呼び方をウェブとする）を流延用支持体上で加熱し溶媒を蒸発させるには、ウェブ側から風を吹かせる方法または支持体の裏面から液体により伝熱させる方法、輻射熱により表裏から伝熱する方法等があるが、裏面液体伝熱の方法が乾燥効率がより好ましい。またそれらを組み合わせる方法も好ましい。
【０１２３】
支持体上で溶媒が蒸発したウェブを、剥離位置で剥離した後、剥離されたウェブは次工程に送られる。剥離する時点でのウェブの残留溶媒量があまり大きすぎると剥離し難かったり、逆に支持体上で十分に乾燥させてから剥離すると、途中でウェブの一部が剥がれたりする。
【０１２４】
製膜速度を上げる方法として、残留溶媒が多くとも剥離できるゲル流延法（ゲルキャスティング）がある。ドープ中にセルロースエステルに対する貧溶媒を加えて、ドープ流延後、ゲル化する方法、支持体の温度を低めてゲル化する方法等がある。残留溶媒量がより多い時点で剥離する場合、ウェブが柔らかすぎると剥離時平面性を損なったり、剥離張力によるツレや縦スジが発生し易く、経済速度と品質との兼ね合いで剥離残留溶媒量を決められる。
【０１２５】
乾燥はウェブを千鳥状に配置したロールに交互に通して搬送する乾燥装置またはクリップでウェブの両端をクリップして搬送するテンター装置を用いてウェブを乾燥する工程であり、乾燥の手段はウェブの両面に熱風を吹かせるのが一般的であるが、風の代わりにマイクロウエーブを当てて加熱する手段もある。あまり急激な乾燥はフィルムの平面性を損ね易い。高温による乾燥は残留溶媒が８質量％以下くらいから行うのがよい。全体を通して、通常乾燥温度は４０〜２５０℃で、７０〜１８０℃が好ましい。使用する溶媒によって、乾燥温度、乾燥風量及び乾燥時間が異なり、使用溶媒の種類、組み合わせに応じて乾燥条件を適宜選べばよい。
【０１２６】
流延用支持体面から剥離した後の乾燥工程では、溶媒の蒸発によってウェブは巾方向に収縮しようとする。高温度で急激に乾燥するほど収縮が大きくなる。この収縮を可能な限り抑制しながら乾燥することが、でき上がったフィルムの平面性を良好にする上で好ましい。この観点から、例えば、特開昭６２−４６６２５号に示されているような乾燥全工程或いは一部の工程を巾方向にクリップでウェブの巾両端を巾保持しつつ乾燥させる方法（テンター方式）が好ましい。
【０１２７】
ウェブを残留溶媒量が質量で２％以下、好ましくは０．４％以下となってからフィルムとして巻き取る。巻き取り方法は、一般に使用されているものを用いればよく、定トルク法、定テンション法、テーパーテンション法、内部応力一定のプログラムテンションコントロール法等があり、それらを使いわければよい。
【０１２８】
得られるフィルムの膜厚の調節には所望の厚みになるように、ドープ濃度、ポンプの送液量、ダイの口金のスリット間隙、ダイの押し出し圧力、流延用支持体の速度をコントロールするのがよい。また、膜厚を均一にする手段として、膜厚検出手段を用いて、プログラムされたフィードバック情報を上記各装置にフィードバックさせて調節するのが好ましい。
【０１２９】
本発明に係わるディスプレイ用フィルムは、従ってこれらの可塑剤を有しないかまたはセルロースエステルに対して１質量％未満の量で含有するセルロースエステルフィルム上に、或いは水、水蒸気等に対するガスバリア層を積層した透明積層フィルムである。ガスバリア膜は片面に積層されて形成されていても良いし、両面に形成されていてもよい。
【０１３０】
ガスバリア層としては、金属酸化物、金属窒化物或いは金属酸窒化物を含有する膜が好ましく挙げられ、これを基材フィルムである前記可塑剤を含有しないかまたは１質量％以下の量含有するセルロースエステルフィルム上に積層することで、線膨張率が低く、かつ水透過性の低い、基板材料等として好適なディスプレイ用フィルムが得られる。
【０１３１】
本発明において、金属酸化物、金属窒化物或いは金属酸窒化物を含有するとは、これを主成分として有することであり、即ち、全構成成分中８０％以上を金属酸化物、金属窒化物或いは金属酸窒化物が占めるということである。
【０１３２】
こうした膜に使用される金属酸化物、金属窒化物、金属酸窒化物としてはケイ素、ジルコニウム、チタン、タングステン、タンタル、アルミニウム、亜鉛、インジウム、クロム、バナジウム、スズ、ニオブから選ばれる１種類以上の元素の酸化物あるいは窒化物、酸窒化物が挙げられ、更に具体的には、酸化珪素、酸化チタン、酸化スズ、アルミナ等金属酸化物、窒化珪素等の金属窒化物、また酸窒化珪素、酸窒化チタン等の金属酸窒化物等である。特に好ましくは酸化ケイ素が主たる成分である金属酸化物膜である。主たる成分であるとは、防湿膜の成分内の比率が８０質量％以上であることをいう。
【０１３３】
金属酸化物或いは窒化物、酸窒化物を含有する膜は、例えば、ゾルゲル法といわれる溶液を塗設する方法、又、真空蒸着、スパッタリング、ＣＶＤ法（化学蒸着）等如何なる方法で形成してもよいが、後述する大気圧或いは大気圧近傍でのプラズマ処理による方法で形成するのが好ましい。即ち有機金属化合物を反応性ガスとして用い、対向する電極間でプラズマ状態とした反応性ガスに基材フィルムを曝すことで基材フィルム上に膜形成を行う大気圧プラズマ法が、緻密な膜を形成できることと、反応性ガスの選択、更にプラズマ発生条件によって、膜の物性等を制御できるため好ましい。
【０１３４】
酸化珪素は透明性が高いものの、水分等のガスバリア性を更に向上させるため窒素原子を含有させる方が好ましい。窒素源としては後述するシラザンや窒素ガス等を用いることができる。但し、窒素の比率を上昇させるとバリア性は増強されるが、逆に光の透過率が低下するため、基板に光透過性が必要な場合、例えば、酸窒化珪素、又、酸窒化チタンの場合、ＳｉＯ_xＮ_y、ＴｉＯ_xＮ_yという組成で表すとｘ、ｙを以下の式を満足するような値とし光透過性を余り低下させない領域で用いることが好ましい。
【０１３５】
０．４≦ｘ／（ｘ＋ｙ）≦０．８
例えばｘ＝０である場合、すなわちＳｉＮでは殆ど光を通さない。酸素原子、窒素原子の比率はＸＰＳ（ＶＧサイエンティフィック社製ＥＳＣＡＣＡＢ−２００Ｒ）を用いて測定できる。
【０１３６】
水分の透過性が特に少ないことから、金属酸化物或いは窒化物を含有する膜の主成分としては酸化珪素が好ましい。
【０１３７】
これらの金属酸化物或いは窒化物を含有する膜は、大気圧若しくはその近傍の圧力下、プラズマＣＶＤ法により不活性ガスおよび金属化合物ガス、例えば有機金属化合物、金属水素化合物等を含有する反応性ガスを用いて基材フィルム上に形成することが好ましい。
【０１３８】
有機金属化合物等の、金属水素化合物等の化合物は常温常圧で、気体、液体、固体いずれの状態であっても構わないが、気体の場合にはそのまま放電空間に導入できる、液体、固体の場合は、加熱、減圧、超音波照射等の手段により気化させて使用する。又、溶媒によって希釈して使用してもよく、溶媒は、メタノール、エタノール、ｎ−ヘキサンなどの有機溶媒及びこれらの混合溶媒が使用出来る。尚、これらの希釈溶媒は、プラズマ放電処理中において、分子状、原子状に分解されるため、影響は殆ど無視することができる。
【０１３９】
有機金属化合物としては、上記酸化珪素膜を形成するためには腐食性、有害ガスの発生がなく、工程上の汚れなども少ないことから、例えば、下記一般式（Ｉ）〜（Ｖ）で表される化合物が好ましい。
【０１４０】
【化５】

【０１４１】
式中、Ｒ₂₁からＲ₂₆は、水素原子または１価の基を表す。ｎ１は自然数を表す。
【０１４２】
一般式（Ｉ）で表される化合物の例としては、ヘキサメチルジシロキサン（ＨＭＤＳＯ）、テトラメチルジシロキサン（ＴＭＤＳＯ）、１，１，３，３，５，５−ヘキサメチルトリシロキサン等が挙げられる。
【０１４３】
【化６】

【０１４４】
式中、Ｒ₃₁およびＲ₃₂は、水素原子または１価の基を表す。ｎ２は自然数を表す。
【０１４５】
一般式（II）で表される化合物の例としては、ヘキサメチルシクロテトラシロキサン、オクタメチルシクロテトラシロキサン、デカメチルシクロペンタシロキサン等が挙げられる。
【０１４６】
一般式（III）
（Ｒ₄₁）_nＳｉ（Ｒ₄₂）_4-n
式中、Ｒ₄₁およびＲ₄₂は、水素原子または１価の基を表す。ｎは、０から３までの整数を表す。
【０１４７】
一般式（III）で表される、有機珪素化合物の例としては、テトラエトキシシラン（ＴＥＯＳ）、メチルトリメトキシシラン、メチルトリエトキシシラン、ジメチルジメトキシシラン、ジメチルジエトキシシラン、トリメチルエトキシシラン、エチルトリメトキシシラン、エチルトリエトキシシラン、ｎ−プロピルトリメトキシシラン、ｎ−プロピルトリエトキシシラン、ｎ−ブチルトリメトキシシラン、ｉ−ブチルトリメトキシシラン、ｎ−へキシルトリメトキシシラン、フェニルトリメトキシシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン等が挙げられる。
【０１４８】
【化７】

【０１４９】
式中、Ａは、単結合あるいは２価の基を表す。Ｒ₅₁〜Ｒ₅₅は、それぞれ独立に水素原子、ハロゲン原子、アルキル基、シクロアルキル基、アルケニル基、アリール基、芳香族複素環基、アミノ基またはシリル基を表す。Ｒ₅₁およびＲ₅₂、Ｒ₅₄およびＲ₅₅は縮合して環を形成していてもよい。
【０１５０】
一般式（IV）において、Ａとして好ましくは単結合あるいは、炭素数１〜３の２価の基である。Ｒ₅₄およびＲ₅₅は縮合して環を形成していてもよく、形成される環としては例えばピロール環、ピペリジン環、ピペラジン環、イミダゾール環等を挙げることができる。Ｒ₅₁〜Ｒ₅₃は好ましくは水素原子、メチル基またはアミノ基である。
【０１５１】
一般式（IV）で表される化合物の例としては、アミノメチルトリメチルシラン、ジメチルジメチルアミノシラン、ジメチルアミノトリメチルシラン、アリルアミノトリメチルシラン、ジエチルアミノジメチルシラン、１−トリメチルシリルピロール、１−トリメチルシリルピロリジン、イソプロピルアミノメチルトリメチルシラン、ジエチルアミノトリメチルシラン、アニリノトリメチルシラン、２−ピペリジノエチルトリメチルシラン、３−ブチルアミノプロピルトリメチルシラン、３−ピペリジノプロピルトリメチルシラン、ビス（ジメチルアミノ）メチルシラン、１−トリメチルシリルイミダゾール、ビス（エチルアミノ）ジメチルシラン、ビス（ジメチルアミノ）ジメチルシラン、ビス（ブチルアミノ）ジメチルシラン、２−アミノエチルアミノメチルジメチルフェニルシラン、３−（４−メチルピペラジノプロピル）トリメチルシラン、ジメチルフェニルピペラジノメチルシラン、ブチルジメチル−３−ピペラジノプロピルシラン、ジアニリノジメチルシラン、ビス（ジメチルアミノ）ジフェニルシラン等があげられる。
【０１５２】
一般式（IV）において、特に好ましい化合物は一般式（Ｖ）で表されるものである。
【０１５３】
【化８】

【０１５４】
式中、Ｒ₆₁からＲ₆₆はそれぞれ独立に水素原子、ハロゲン原子、アルキル基、シクロアルキル基、アルケニル基、アリール基または芳香族複素環基を表す。
【０１５５】
一般式（Ｖ）においてＲ₆₁からＲ₆₆は気化の容易性の観点から好ましくは炭素数１〜１０の炭化水素基であり、より好ましくはＲ₆₁からＲ₆₃のうちすくなくとも２つおよびＲ₆₄からＲ₆₆のうち少なくとも２つがメチル基のものである。
一般式（Ｖ）で表される化合物の例としては、１，１，３，３−テトラメチルジシラザン、１，３−ビス（クロロメチル）−１，１，３，３−テトラメチルジシラザン、ヘキサメチルジシラザン、１，３−ジビニル−１，１，３，３−テトラメチルジシラザン等が挙げられる。
【０１５６】
又、酸化スズを形成するためには例えば、ジブチル錫ジアセテート等があげられる。
【０１５７】
又、更に酸素ガスや窒素ガスを所定割合で上記有機金属化合物と組み合わせて、酸素原子と窒素原子の少なくともいずれかと珪素或いは、錫等の金属原子を含有する膜を得ることが出来る。
【０１５８】
更に、膜中の炭素含有率を調整するために前記の如く混合ガス中に水素ガス等を混合してもよく、これらの反応性ガスに対して、周期表の第１８属原子、具体的には、ヘリウム、ネオン、アルゴン、クリプトン、キセノン、ラドン等、特に、ヘリウム、アルゴンが好ましく用いられるが、不活性ガスを混合し、混合ガスとしてプラズマ放電発生装置（プラズマ発生装置）に供給することで膜形成を行う。不活性ガスと反応性ガスの割合は、得ようとする膜の性質によって異なるが、混合ガス全体に対し、不活性ガスの割合を９０．０〜９９．９％として反応性ガスを供給する。
【０１５９】
前記シラザンを用いることで酸窒化珪素（ＳｉＯＮ）を含んだ膜を形成することができる。
【０１６０】
Ｓｉ源としては、上記のような有機珪素化合物だけでなく、無機珪素化合物を用いてもよい。
【０１６１】
又、酸素源として酸素ガス以外にオゾン、二酸化炭素、水（水蒸気）等を用いてもよいし、窒素源としてシラザンや窒素ガス以外に、アンモニア、窒素酸化物等を用いてもよい。
【０１６２】
本発明において、金属酸化物（例えばシリカ）、金属窒化物或いは酸窒化物の膜については、ある程度の厚みがないと水分の封止性が充分でなく、厚いほど水分の阻止性に優れるがクラックが生じやすくなるため７０ｎｍ〜１５００ｎｍ、より好ましくは１００ｎｍ〜１０００ｎｍの膜厚であることが好ましい。従ってある程度の厚みを有するものであれば塗布によって所謂ゾルゲル法等を用いて基材フィルム上に形成されていてもよく、これにより厚みのある膜を一度に形成出来るという点では効果的である。
【０１６３】
しかしながら、厚い膜についても大気圧プラズマ法によって形成することが膜が緻密であるため好ましく、やや厚みのある膜の場合には、プラズマ処理の回数、時間等を増やす等の方法で作製することが好ましい。
【０１６４】
（プラズマ製膜装置）
大気圧プラズマ法によって金属酸化物（例えばシリカ）或いは窒化物の膜を基材フィルム上に形成するプラズマ製膜装置については種々の装置を用いることが可能であり、前記の処理装置を用いても構わないが、長尺状の基材フィルムに金属酸化物（例えばシリカ）或いは窒化物の膜を形成するために使用される好ましいプラズマ製膜装置の例を図２〜図７に示した。図中、符号Ｆは金属酸化物（例えばシリカ）或いは窒化物の膜を形成するため基材の一例としての長尺フィルムである。
【０１６５】
これらの放電プラズマ処理は大気圧又は大気圧近傍で行われる。大気圧近傍とは、前述のように２０ｋＰａ〜１１０ｋＰａの圧力を表し、更に好ましくは９３ｋＰａ〜１０４ｋＰａである。
【０１６６】
図２は、プラズマ製膜装置に備えられたプラズマ放電処理室の１例を示す概略構成図である。図２のプラズマ放電処理室１０において、基材フィルムＦは搬送方向（図中、時計回り）に回転するロール電極２５に巻き回されながら搬送される。ロール電極２５の周囲に固定されている複数の固定電極２６はそれぞれ円筒から構成され、ロール電極２５に対向させて設置される。
【０１６７】
プラズマ放電処理室１０を構成する放電容器１１はパイレックス（Ｒ）ガラス製の処理容器が好ましく用いられるが、電極との絶縁がとれれば金属製を用いることも可能である。例えば、アルミニウム又はステンレスのフレームの内面にポリイミド樹脂等を貼り付けてもよく、該金属フレームにセラミックス溶射を行い絶縁性をとってもよい。
【０１６８】
ロール電極２５に巻き回された基材フィルムＦは、ニップローラ１５、１５、１６で押圧され、ガイドローラ２４で規制されて放電容器１１内部に確保された放電処理空間に搬送され、放電プラズマ処理され、次いで、ガイドローラ２７を介して次工程に搬送される。本発明では、真空系ではなくほぼ大気圧に近い圧力下で放電処理により製膜できることから、このような連続工程が可能となり、高い生産性をあげることができる。
【０１６９】
尚、仕切板１４、１４は前記ニップローラ１５、１５、１６に近接して配置され基材フィルムＦに同伴する空気が放電容器１１内に進入するのを抑制する。この同伴される空気は、放電容器１１内の気体の全体積に対し、１体積％以下に抑えることが好ましく、０．１体積％以下に抑えることがより好ましい。前記ニップローラ１５及び１６により、それを達成することが可能である。
【０１７０】
尚、放電プラズマ処理に用いられる混合ガスは、給気口１２から放電容器１１に導入され、処理後のガスは排気口１３から排気される。
【０１７１】
ロール電極２５はアース電極であり、印加電極である複数の固定電極２６との間で放電させ、当該電極間に前述したような反応性ガスを導入してプラズマ状態とし、前記ロール電極２５に巻き回しされた長尺状基材フィルムを前記プラズマ状態の反応性ガスに曝すことによって、反応性ガス由来の膜を形成する。
【０１７２】
前記電極間には、高いプラズマ密度を得て製膜速度を大きくし、更に炭素含有率を所定割合内に制御するため、高周波電圧で、ある程度大きな電力を供給することが好ましい。具体的には、３ｋＨｚ以上１３．５６ＭＨｚ以下の高周波電圧を印加することが好ましく、１０ｋＨｚ以上であれば更に好ましく、５０ｋＨｚ以上であれば更に好ましく、１００ｋＨｚ以上であればより一層好ましい。又、電極間に供給する電力の下限値は、１Ｗ／ｃｍ²以上５０Ｗ／ｃｍ²以下であることが好ましく、２Ｗ／ｃｍ²以上であればより一層好ましい。
【０１７３】
尚、電極における電圧の印加面積（ｃｍ²）は放電が起こる範囲の面積のことである。
【０１７４】
又、電極間に印加する高周波電圧は、断続的なパルス波であっても、連続したサイン波であってもよいが、製膜速度が大きくなることから、サイン波であることが好ましい。
【０１７５】
このような電極としては、金属母材上に誘電体を被覆したものであることが好ましい。少なくとも固定電極２６とロール電極２５のいずれか一方に誘電体を被覆すること、好ましくは、両方に誘電体を被覆することである。誘電体としては、非誘電率が６〜４５の無機物であることが好ましい。
【０１７６】
電極２５、２６の一方に固体誘電体を設置した場合の固体誘電体と電極の最短距離、上記電極の双方に固体誘電体を設置した場合の固体誘電体同士の距離としては、いずれの場合も均一な放電を行う観点から、０．５ｍｍ〜２０ｍｍが好ましく、特に好ましくは１ｍｍ±０．５ｍｍである。この電極間の距離は、電極周囲の誘電体の厚さ、印加電圧の大きさを考慮して決定される。
【０１７７】
又、基材を電極間に載置或いは電極間を搬送してプラズマに曝す場合には、基材を片方の電極に接して搬送出来るロール電極仕様にするだけでなく、更に誘電体表面を研磨仕上げし、電極の表面粗さＲｍａｘ（ＪＩＳ Ｂ ０６０１）を１０μｍ以下にすることで誘電体の厚み及び電極間のギャップを一定に保つことができ放電状態を安定化出来る。更に、誘電体の熱収縮差や残留応力による歪みやひび割れをなくし、且つ、ノンポーラスな高精度の無機誘電体を被覆することで大きく耐久性を向上させることができる。
【０１７８】
又、金属母材に対する誘電体被覆による電極製作において、前記のように、誘電体を研磨仕上げすることや、電極の金属母材と誘電体間の熱膨張の差をなるべく小さくすることが必要であるので、母材表面に、応力を吸収出来る層として泡混入量をコントロールして無機質の材料をライニングすることが好ましい。特に材質としては琺瑯等で知られる溶融法により得られるガラスであることがよく、更に導電性金属母材に接する最下層の泡混入量を２０〜３０体積％とし、次層以降を５体積％以下とすることで、緻密且つひび割れ等の発生しない良好な電極ができる。
【０１７９】
又、電極の母材に誘電体を被覆する別の方法として、セラミックスの溶射を空隙率１０ｖｏｌ％以下まで緻密に行い、更にゾルゲル反応により硬化する無機質の材料にて封孔処理を行うことがあげられる。ここでゾルゲル反応の促進には、熱硬化やＵＶ硬化がよく、更に封孔液を希釈し、コーティングと硬化を逐次で数回繰り返すと、より一層無機質化が向上し、劣化のない緻密な電極ができる。
【０１８０】
図３（ａ）及び図３（ｂ）はロール電極２５の一例を示す図であり、ロール電極２５ｃ、２５Ｃを示している。
【０１８１】
アース電極であるロール電極２５ｃは、図３（ａ）に示すように、金属等の導電性母材２５ａに対しセラミックスを溶射後、無機材料を用いて封孔処理したセラミック被覆処理誘電体２５ｂを被覆した組み合わせで構成されているものである。セラミック被覆処理誘電体を１ｍｍ被覆し、ロール径を被覆後２００φとなるように製作し、アースに接地する。溶射に用いるセラミックス材としては、アルミナ・窒化珪素等が好ましく用いられるが、この中でもアルミナが加工しやすいので、更に好ましく用いられる。
【０１８２】
或いは、図３（ｂ）に示すロール電極２５Ｃの様に、金属等の導電性母材２５Ａへライニングにより無機材料を設けたライニング処理誘電体２５Ｂを被覆した組み合わせから構成してもよい。ライニング材としては、珪酸塩系ガラス、硼酸塩系ガラス、リ酸塩系ガラス、ゲルマン酸塩系ガラス、亜テルル酸塩ガラス、アルミン酸塩系ガラス、バナジン酸塩ガラスが好ましく用いられるが、この中でもホウ酸塩系ガラスが加工しやすいので、更に好ましく用いられる。
【０１８３】
金属等の導電性母材２５ａ、２５Ａとしては、銀、白金、ステンレス、アルミニウム、鉄等の金属等が挙げられるが、加工の観点からステンレスが好ましい。
【０１８４】
又、尚、本実施の形態においては、ロール電極の母材は冷却水による冷却手段を有するステンレス製ジャケットロール母材を使用している（不図示）。
【０１８５】
更に、ロール電極２５ｃ、２５Ｃ（ロール電極２５も同様）は、図示しないドライブ機構により軸部２５ｄ、２５Ｄを中心として回転駆動される様に構成されている。
【０１８６】
図４（ａ）には固定電極２６の概略斜視図を示した。又、固定電極は、円筒形状に限らず、図４（ｂ）の固定電極３６の様に角柱型でもよい。円柱型の電極２６に比べて、角柱型の電極は放電範囲を広げる効果があるので、形成する膜の性質などに応じて好ましく用いられる。
【０１８７】
固定電極２６、３６いずれであっても上記記載のロール電極２５ｃ、ロール電極２５Ｃと同様な構造を有する。すなわち、中空のステンレスパイプ２６ａ、３６ａの周囲を、ロール電極２５（２５ｃ、２５Ｃ）同様に、誘電体２６ｂ、３６ｂで被覆し、放電中は冷却水による冷却が行えるようになっている。誘電体２６ｂ、３６ｂは、セラミック被覆処理誘電体及びライニング処理誘電体のいずれでもよい。
【０１８８】
尚、固定電極は誘電体の被覆後１２φ又は１５φとなるように製作され、当該電極の数は、例えば上記ロール電極の円周上に沿って１４本設置している。
【０１８９】
図５には、図４（ｂ）の角型の固定電極３６をロール電極２５の周りに配設したプラズマ放電処理室３０の概略構成図を示した。図５において、図２と同じ部材については同符号を伏して説明を省略する。
【０１９０】
図６には、図５のプラズマ放電処理室３０が設けられたプラズマ製膜装置５０の概略構成図を示した。図６において、プラズマ放電処理室３０の他に、ガス発生装置５１、電源４１、電極冷却ユニット５５等が装置構成として配置されている。電極冷却ユニット５５は、冷却剤の入ったタンク５７とポンプ５６とからなる。冷却剤としては、蒸留水、油等の絶縁性材料が用いられる。
【０１９１】
図６のプラズマ放電処理室３０内の電極間のギャップは、例えば１ｍｍ程度に設定される。
【０１９２】
プラズマ放電処理室３０内にロール電極２５、固定電極３６を所定位置に配置し、ガス発生装置５１で発生させた混合ガスを流量制御して、給気口１２より供給し、処理容器１１内をプラズマ処理に用いる混合ガスで充填し不要分については排気口より排気する。
【０１９３】
次に電源４１により固定電極３６に電圧を印加し、ロール電極２５はアースに接地し、放電プラズマを発生させる。ここでロール状の元巻き基材ＦＦからロール５４、５４、５４を介して基材が供給され、ガイドロール２４を介して、プラズマ放電処理室３０内の電極間をロール電極２５に片面接触した状態で搬送される。このとき放電プラズマにより基材Ｆの表面が放電処理され、その後にガイドロール２７を介して次工程に搬送される。ここで、基材フィルムＦはロール電極２５に接触していない面のみ放電処理がなされる。
【０１９４】
又、放電時の高温による悪影響を抑制するため、基材の温度を常温（１５℃〜２５℃）〜２００℃未満、更に好ましくは常温〜１００℃内で抑えられるように必要に応じて電極冷却ユニット５５で冷却する。
【０１９５】
又、図７は、本発明の膜の形成方法で用いることができる別のプラズマ製膜装置の概略構成図であり、電極間に載置できない様な性状、例えば厚みのある基材上に膜を形成する場合に、予めプラズマ状態にした反応性ガスを基材上に噴射して薄膜を形成するためのものである。
【０１９６】
図７のプラズマ製膜装置６０において、３５ａは誘電体、３５ｂは金属母材、６５は電源である。金属母材３５ｂに誘電体３５ａを被覆したスリット状の放電空間に、上部から不活性ガス及び反応性ガスからなる混合ガスを導入し、電源６５により高周波電圧を印加することにより反応性ガスをプラズマ状態とし、該プラズマ状態の反応性ガスを基材６１上に噴射することにより基材６１表面に膜を形成する。
【０１９７】
図６の電源４１、図７の電源６５などの本発明の膜の形成に用いるプラズマ製膜装置の電源としては、特に限定はないが、ハイデン研究所製インパルス高周波電源（連続モードで使用１００ｋＨｚ）、パール工業製高周波電源（２００ｋＨｚ）、パール工業製高周波電源（８００ｋＨｚ）、日本電子製高周波電源（１３．５６ＭＨｚ）、パール工業製高周波電源（１５０ＭＨｚ）等が使用出来る。
【０１９８】
この様なプラズマ製膜装置を用い、大気圧プラズマ法により、本発明に係わるガスバリア層としての金属酸化物或いは窒化物を含有する膜を形成できる。
【０１９９】
本発明に係わる好ましいセルロースエステルを主体とする前記のフィルムとしては、少なくとも一方の面に膜厚が７０ｎｍ以上、好ましくは１５００ｎｍ以下の膜前記ガスバリア層を有するフィルムである。
【０２００】
本発明に係わる透明積層フィルムは、基材としての樹脂フィルムの特徴である可撓性を維持しつつ、線膨張率が非常に小さく、防湿ガスバリア層の形成により樹脂フィルム中への水分や水蒸気等の透過を防止できるため、例えば、液晶表示素子、有機エレクトロルミネッセンス（ＥＬ）素子用の基板として、非常に優れたものである。
【０２０１】
また、Ｊ．Ｓｏｌ−Ｇｅｌ Ｓｃｉ．Ｔｅｃｈ．，ｐ１４１〜１４６（１９９８）に開示されているように、ガスバリア層に用いられる金属酸化物や金属窒化物、金属酸窒化物の薄膜のひび割れ（クラック）防止のため、金属酸化物や金属窒化物、金属酸窒化物の防湿膜の上に各種コーティング材を塗布することで前記クラックを封止し、一層の透湿度の低減をはかることもできる。
【０２０２】
【実施例】
以下に、本発明を実施例により具体的に説明するが、本発明はこれらの実施例によって限定されるものではない。
【０２０３】
実施例１
〈参考の透明フィルム１０１の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、トリアセチルセルロース（ダイセル化学工業製ＬＴ５５、以下ＴＡＣ）１０．０ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、参考の透明フィルム１０１とした。フィルムの厚みは１００μｍだった。
【０２０４】
〈本発明の透明フィルム１０２の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ＴＡＣ９．９９ｇと、エチルフタリルエチルグリコレート（例示化合物１、以下ＥＰＥＧ）０．０１ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、本発明の透明フィルム１０２とした。フィルムの厚みは１００μｍだった。
【０２０５】
〈本発明の透明フィルム１０３の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ＴＡＣ９．９５ｇと、ＥＰＥＧ０．０５ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、本発明の透明フィルム１０３とした。フィルムの厚みは１００μｍだった。
【０２０６】
〈参考の透明フィルム１０４の作製〉
テトラメトキシシラン２．５３ｇと塩化メチレン１．２７ｇ、エタノール１．２７ｇを混合した後、０．５％硝酸水溶液を０．６０ｇ加えて加水分解を行い、室温でそのまま１時間攪拌を続けた。
【０２０７】
エタノール６．２ｇと塩化メチレン６０．９ｇの混合溶媒に、ＴＡＣ９．０ｇを溶解させた後、テトラメトキシシランを加水分解した前記の溶液と混合し、さらに１時間攪拌を行った後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、参考の透明フィルム１０４とした。フィルムの厚みは１００μｍだった。
【０２０８】
〈本発明の透明フィルム１０５の作製〉
テトラメトキシシラン２．５３ｇと塩化メチレン１．２７ｇ、エタノール１．２７ｇを混合した後、０．５％硝酸水溶液を０．６０ｇ加えて加水分解を行い、室温でそのまま１時間攪拌を続けた。
【０２０９】
エタノール６．２ｇと塩化メチレン６０．９ｇの混合溶媒に、ＴＡＣ８．９９ｇとＥＰＥＧ０．０１ｇを溶解させた後、テトラメトキシシランを加水分解した前記の溶液と混合し、さらに１時間攪拌を行った後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、本発明の透明フィルム１０５とした。フィルムの厚みは１００μｍだった。
【０２１０】
〈本発明の透明フィルム１０６の作製〉
テトラメトキシシラン２．５３ｇと塩化メチレン１．２７ｇ、エタノール１．２７ｇを混合した後、０．５％硝酸水溶液を０．６０ｇ加えて加水分解を行い、室温でそのまま１時間攪拌を続けた。
【０２１１】
エタノール６．２ｇと塩化メチレン６０．９ｇの混合溶媒に、ＴＡＣ８．９５ｇとＥＰＥＧ０．０５ｇを溶解させた後、テトラメトキシシランを加水分解した前記の溶液と混合し、さらに１時間攪拌を行った後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、本発明の透明フィルム１０６とした。フィルムの厚みは１００μｍだった。
【０２１２】
〈参考の透明フィルム１０７の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ジアセチルセルロース（ダイセル化学工業製Ｌ５０、以下ＤＡＣ）１０．０ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、参考の透明フィルム１０７とした。フィルムの厚みは１００μｍだった。
【０２１３】
〈本発明の透明フィルム１０８の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ＴＡＣを９．９９ｇと、例示化合物１６を０．０１ｇ溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、本発明の透明フィルム１０８とした。フィルムの厚みは１００μｍだった。
【０２１４】
〈本発明の透明フィルム１０９の作製〉
テトラメトキシシラン２．５３ｇと塩化メチレン１．２７ｇ、エタノール１．２７ｇを混合した後、０．５％硝酸水溶液を０．６０ｇ加えて加水分解を行い、室温でそのまま１時間攪拌を続けた。
【０２１５】
エタノール６．２ｇと塩化メチレン６０．９ｇの混合溶媒に、ＤＡＣを８．９９ｇと、例示化合物１６を０．０１ｇ溶解させた後、テトラメトキシシランを加水分解した前記の溶液と混合し、さらに１時間攪拌を行った後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、本発明の透明フィルム１０９とした。フィルムの厚みは１００μｍだった。
【０２１６】
〈参考の透明フィルム１１０の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ＴＡＣを５．０ｇと、ＤＡＣを５．０ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、参考の透明フィルム１１０とした。フィルムの厚みは１００μｍだった。
【０２１７】
〈比較例の透明フィルム１１１の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ＴＡＣを９．９０ｇと、ＥＰＥＧを０．１０ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、比較例の透明フィルム１１１とした。フィルムの厚みは１００μｍだった。
【０２１８】
〈比較例の透明フィルム１１２の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ＴＡＣを９．７０ｇと、ＥＰＥＧを０．３０ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、比較例の透明フィルム１１２とした。フィルムの厚みは１００μｍだった。
【０２１９】
〈比較例の透明フィルム１１３の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ＴＡＣを９．５０ｇと、ＥＰＥＧを０．５０ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、比較例の透明フィルム１１３とした。フィルムの厚みは１００μｍだった。
【０２２０】
〈比較例の透明フィルム１１４の作製〉
エタノール６．０ｇと塩化メチレン６８．５ｇの混合溶媒に、ＤＡＣを９．９０ｇと、例示化合物１６を０．１０ｇを溶解後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、比較例の透明フィルム１１４とした。フィルムの厚みは１００μｍだった。
【０２２１】
〈比較例の透明フィルム１１５の作製〉
テトラメトキシシラン２．５３ｇと塩化メチレン１．２７ｇ、エタノール１．２７ｇを混合した後、０．５％硝酸水溶液を０．６０ｇ加えて加水分解を行い、室温でそのまま１時間攪拌を続けた。
【０２２２】
エタノール６．２ｇと塩化メチレン６０．９ｇの混合溶媒に、ＤＡＣを８．９９ｇと、例示化合物１６を０．１０ｇ溶解させた後、テトラメトキシシランを加水分解した前記の溶液と混合し、さらに１時間攪拌を行った後、ガラス板上にギャップ巾１０００μｍのドクターブレードで成膜し、得られたフィルムを１２０℃で３０分間乾燥させ、比較例の透明フィルム１１５とした。フィルムの厚みは１００μｍだった。
【０２２３】
〈比較例の透明フィルム１１６〉
フィルム厚５０μｍのポリエーテルスルホンフィルムである住友ベークライト（株）製「スミライト ＦＳ−１３００」を比較例の透明フィルム１１６とした。
【０２２４】
〈比較例の透明フィルム１１７〉
フィルム厚１００μｍのポリノルボルネンフィルムであるＪＳＲ（株）製「アートン」を比較例の透明フィルム１１７とした。
【０２２５】
作製した本発明の透明フィルム１０１〜１１０および比較例の透明フィルム１１１〜１１７について、下記の評価を行った。
【０２２６】
《透過率の測定》
ＪＩＳ Ｋ７３６１−１に基づき、東京電色製ＴＵＲＢＩＤＩＴＹ ＭＥＴＥＲ Ｔ−２６００ＤＡで測定した。
【０２２７】
《ガラス転移温度、線膨張率の測定》
本発明のセルロースエステル類のガラス転移温度は、走査型示差熱量計（ＤＳＣ）の測定では、不明確で測定されないことが多いため、熱応力歪み測定（ＴＭＡ）における温度−歪み曲線の変曲点をガラス転移温度とした。
【０２２８】
熱応力歪み測定にはセイコーインスツルメンツ社製ＴＭＡ−ＳＳ６１００を用い、膜厚１００μｍ、巾４ｍｍの試料を、チャック間距離２０ｍｍで固定し、室温から１８０℃まで一旦昇温して残留ひずみを取ったあと、室温から５℃／ｍｉｎ．で２５０℃まで昇温し、ＪＩＳ Ｋ７１９７に基づき、チャック間距離の伸びから線膨張率を求めた。
【０２２９】
《複屈折、波長分散特性の測定》
王子計測機器（株）製自動複屈折計ＫＯＢＲＡ−２１ＡＤＨで測定し、各透明フィルムの面内のＸ方向、Ｙ方向の屈折率の差に、膜厚１００μｍを乗じた値を面内複屈折（ｎｍ）として表した。
【０２３０】
また、４８０ｎｍにおけるリタデーション値Ｒ₀（４８０）及び５９０ｎｍにおけるリタデーション値Ｒ₀（５９０）を、同様にＫＯＢＲＡ−２１ＡＤＨを用いて測定し、下式のように４８０ｎｍでの複屈折値と５９０ｎｍでの複屈折値の比を計算し、複屈折の波長分散を評価した。
【０２３１】
Ｐ＝Ｒ₀（４８０）／Ｒ₀（５９０）
【０２３２】
【表１】

【０２３３】
表１に示されるように、可塑剤の添加量が増えるに従ってガラス転移温度が低下し、かつ線膨張率も上昇しているが、透明フィルム１０３と透明フィルム１１１を比較すると、添加量が１％に達するところでいずれも大きく変化しているため、透明フィルムに好ましい熱特性を付与するためには、可塑剤の添加量は１．０％未満が好ましい。
【０２３４】
また、透明フィルム１０４〜１０６に見られる通り、シリカをＴＡＣにハイブリッドすることにより、ガラス転移温度を向上させることができたが、線膨張率にはほとんど影響がなかった。
【０２３５】
またＴＡＣとＤＡＣを比較すると、ガラス転移温度はＤＡＣの方が高いが、線膨張率はＴＡＣの方が低かった。またＴＡＣとＤＡＣを混合した透明フィルム１１０は、ヘイズを発生することなく透明なフィルムが得られ、両者の中間的な性質の透明フィルムが得られた。
【０２３６】
またセルロース系以外の耐熱性透明フィルム１１６、１１７は、本発明の透明フィルムよりも線膨張率が大きく、また複屈折の波長分散特性が１より大きく好ましくない透明フィルムであった。
【０２３７】
実施例２
実施例１で得られた透明フィルム１０１〜１１７上に、下記ハードコート層塗布組成物が３μｍの膜厚となるように押出しコーターでコーティングし、ついで８０℃に設定された乾燥部で１分間乾燥した後、１２０ｍＪ／ｃｍ²で紫外線照射することにより形成した。ハードコート層は透明フィルムの両面に形成した。
【０２３８】
〈クリアハードコート層塗布組成物〉
ジぺンタエリスリトールヘキサアクリレート単量体 ６０質量部
ジぺンタエリスリトールヘキサアクリレート２量体 ２０質量部
ジぺンタエリスリトールヘキサアクリレート３量体以上の成分 ２０質量部
ジメトキシベンゾフェノン ４質量部
酢酸エチル ５０質量部
メチルエチルケトン ５０質量部
イソプロピルアルコール ５０質量部
〈防湿膜の作成〉
プラズマ放電装置としては、電極が平行平板型のものを用い、この電極間に上記透明フィルムを載置し、且つ、混合ガスを導入して薄膜形成を行った。尚、電極は、以下の物を用いた。
【０２３９】
２００ｍｍ×２００ｍｍ×２ｍｍのステンレス板に高密度、高密着性のアルミナ溶射膜を被覆し、その後、テトラメトキシシランを酢酸エチルで希釈した溶液を塗布乾燥後、紫外線照射により硬化させ封孔処理を行った。このようにして被覆した誘電体表面を研磨し、平滑にして、Ｒｍａｘが５μｍとなるように加工した。このように電極を作成し、アース（接地）した。
【０２４０】
一方、印加電極としては、中空の角型の純チタンパイプに対し、上記同様の誘電体を同条件にて被覆したものを複数作製し、対向する電極群とした。
【０２４１】
また、プラズマ発生に用いる使用電源は日本電子（株）製高周波電源ＪＲＦ−１００００にて周波数１３．５６ＭＨｚの電圧で且つ５Ｗ／ｃｍ²の電力を供給し、電極間に以下の組成の反応性ガスを流した。
不活性ガス：アルゴン ９９．３体積％
反応性ガス１：水素 ０．５体積％
反応性ガス２：テトラエトキシシラン ０．３体積％
クリアハードコート層が設けられた透明フィルム１０１〜１１７のクリアハードコート層上に、上記反応ガス、反応条件により大気圧プラズマ処理を行い、防湿膜として酸化ケイ素膜を両面にそれぞれ膜厚が１００ｎｍとなるように作成し、透明積層フィルム２０１〜２１７とし、下記の評価を行った。
【０２４２】
《透湿度評価》
透湿度はＪＩＳ−Ｚ−０２０８に記載の条件Ｂ（４０℃、９０％ＲＨ）で測定した。透湿度評価は、クリアハードコート層・防湿層の形成前、形成後、に測定した。
【０２４３】
また、１時間１８０℃で加熱後、１時間室温で放冷するという一連の冷熱サイクルを１０回行った後にも測定した。
【０２４４】
【表２】

【０２４５】
セルロースエステル類は、従来透湿度が大きいことが大きな課題であったが、表２で示されたように、大気圧プラズマ処理によって設けられた酸化ケイ素膜によって高い防湿性が付与された。また本発明の透明フィルムは線膨張率が小さいため、冷熱サイクルを経た後でも透湿度の劣化が小さく、良好な透明フィルムであった。
【０２４６】
一方比較例の透明積層フィルム２１１〜２１６は、基材である透明フィルム１１１〜１１６の線膨張率が大きいため、防湿層を形成することによって低い透湿度を達成できるものの、冷熱サイクルを経た後では支持体の膨張と収縮により防湿層がひび割れ透湿度が悪化してしまい、好ましくない透明積層フィルムであった。
【０２４７】
また透明積層フィルム２１７は、基材である透明フィルム１１７のガラス転移温度が低いため、冷熱サイクル中に軟化して変形し、透湿度測定を行うことができなくなってしまい、好ましくない透明積層フィルムであった。
【０２４８】
【発明の効果】
本発明によれば線膨張率、透湿度が低く、ディスプレイ用各種フィルム、特に基板用フィルムとして好適な透明積層フィルムが得られた。
【図面の簡単な説明】
【図１】熱応力歪み測定の結果を示す図である。
【図２】プラズマ放電処理室の一例を示す図である。
【図３】ロール電極の一例を示す図である。
【図４】固定電極の概略斜視図である。
【図５】角型の固定電極をロール電極２５の周りに配設したプラズマ放電処理室を示す図である。
【図６】プラズマ放電処理室が設けられたプラズマ製膜装置を示す図である。
【図７】プラズマ製膜装置の別の一例を示す図である。
【符号の説明】
１０、３０ プラズマ放電処理室
２５、２５ｃ、２５Ｃ ロール電極
２６、２６ｃ、２６Ｃ、３６、３６ｃ、３６Ｃ 電極
２５ａ、２５Ａ、２６ａ、３６ａ 金属等の導電性母材
２５ｂ、２６ｂ、３６ｂ セラミック被覆処理誘電体
２５Ｂ ライニング処理誘電体
４１ 電源
５１ ガス発生装置
１２ 給気口
１３ 排気口
５５ 電極冷却ユニット
ＦＦ 元巻き基材
１５、１６ ニップローラ
２４、２７ ガイドローラ
Ｆ 基材フィルム[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transparent laminated film having a gas barrier layer on a transparent support.
[0002]
[Prior art]
Conventionally, liquid crystal display elements, organic EL display elements, plasma displays, electronic display substrates such as electronic paper, electro-optical element substrates such as CCD and CMOS sensors, solar cell substrates, etc. are thermally stable and transparent. Glass has been used because of its high property and low water vapor permeability. However, with the recent popularization of mobile phones or portable information terminals, there has been a demand for a plastic substrate that is flexible and resistant to cracking with respect to relatively heavy glass that is easy to break for those substrates.
[0003]
However, plastics generally have a higher moisture permeability and hygroscopic expansion coefficient than glass, and therefore various gas barrier layers are required to dampen elements that are degraded by moisture, such as organic electroluminescent elements (organic EL elements). there were.
[0004]
When the gas barrier layer, the transparent conductive layer, the TFT layer for switching the pixel, the organic EL element that becomes the pixel, or the liquid crystal display element is formed on the transparent substrate, it is exposed to a thermal history from room temperature to several hundred degrees. The substrate on which these elements are formed is required to have heat resistance.
[0005]
Regarding heat resistance, transparent resin substrate materials improved by cross-linking resins, and further proposals such as using different transparent resin substrates as laminated composite substrates have been made, and plastic materials that replace glass materials have been proposed. It is being considered.
[0006]
Also, when considered as a substrate material, particularly when used for a liquid crystal panel or the like, since a display method using birefringence is adopted, in order to compensate for polarization in the entire wavelength range of visible light, The birefringence wavelength dispersion is preferably positive dispersion, but none of the resin substrates having improved heat resistance have sufficient performance for substrates such as birefringence wavelength dispersion is not positive dispersion.
[0007]
It is known that the birefringence wavelength dispersion of a triacetyl cellulose film is positive dispersion. Moreover, it is disclosed in Patent Document 1 that triacetyl cellulose not containing a plasticizer is excellent in moisture and heat resistance and is preferable for a polarizing plate, and Patent Document 2 also has a relatively small amount of plasticizer (1 to 1). 7% by weight) cellulose ester film is disclosed, and it is known that it has characteristics such as excellent deformation resistance under high temperature and high humidity.
[0008]
On the other hand, when the amount of plasticizer is reduced, moisture permeability deteriorates, and it is also known that the element deteriorates due to moisture, and the hygroscopic expansion coefficient deteriorates, causing problems such as film deformation under high humidity. Yes.
[0009]
As a film for a substrate, in particular, when producing a full-color display element, it is necessary not only to be deformed by humidity but also to be not easily deformed or stretched by heat (low linear expansion coefficient). In the manufacture of the liquid crystal display element, the organic EL element, etc., the expansion and contraction due to the heat of the substrate is formed over a plurality of layers of unit elements, wiring patterns, etc. constituting the pixel. The expansion and contraction of the substrate causes the pixel to constitute a pixel, and the unit constituting each laminated pixel such as a thin film transistor, a capacitor, each wiring, and an electrode pattern causes an optical misalignment between layers, and the light emission position is slightly shifted. In addition, undesired phenomena such as an electrical connection between layers being shifted are caused. Therefore, it is important that the display element substrate has a low coefficient of linear expansion as well as heat resistance.
[0010]
Even in the triacetyl cellulose film, a certain degree of heat resistance and moisture resistance have been achieved, but from the viewpoint of the linear expansion coefficient, at present, a plastic substrate having characteristics approaching glass is not yet known, Furthermore, in reality, a plastic substrate material that can replace a glass substrate that satisfies both the linear expansion coefficient and the moisture permeability is not yet known.
[0011]
[Patent Document 1]
JP-A-1-214802
[0012]
[Patent Document 2]
JP 10-152568 A
[0013]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a transparent laminated film having low linear expansion coefficient and moisture permeability and suitable as various films for display, particularly as a film for substrates.
[0014]
[Means for Solving the Problems]
  The above problems of the present invention are as follows.(1)-(8)This is achieved by the following means.
  (1) A transparent laminated film having a gas barrier layer on a transparent support, wherein the transparent support is mainly a cellulose ester, and the plasticizer content is 0.1 mass% to 0.5 mass% A transparent laminated film, wherein the plasticizer is a polyhydric alcohol ester having an aromatic ring or a cycloalkyl ring in the molecule or a glycolate plasticizer having an aromatic ring or a cycloalkyl ring in the molecule.
  (2) The transparent support comprising mainly cellulose ester contains 0 to 20% by mass of metal oxide fine particles comprising a polycondensate of a reactive metal compound capable of hydrolytic polycondensation ( The transparent laminated film as described in 1).
(3) The transparent laminated film as described in (2) above, wherein the metal oxide fine particles are hydrolyzed polycondensates of alkoxysilanes represented by the following general formula (1).
  General formula (1)
    R _4-n Si (OR ') _n
(In the formula, R and R ′ represent a hydrogen atom or a monovalent substituent, and n is 3 or 4.)
  (4) R is the in-plane retardation value at a wavelength of 590 nm. ₀ (590), the in-plane retardation value at a wavelength of 480 nm is R ₀ (480), the ratio R ₀ (480) / R ₀ (590) The value is 0.8 or more and less than 1.0, The transparent laminated film of any one of said (1)-(3) characterized by the above-mentioned.
  (5) Moisture permeability is 10 g / m ² / D or less, The transparent laminated film of any one of said (1)-(4) characterized by the above-mentioned.
  (6) The transparent laminated film according to any one of (1) to (5), wherein the gas barrier layer is mainly composed of silicon oxide.
  (7) The transparent laminated film according to any one of (1) to (4), wherein the transparent support is produced by a solvent casting method.
  (8) The method for producing a transparent laminated film according to any one of (1) to (7) above, wherein a high-frequency voltage is applied between opposing electrodes under atmospheric pressure or a pressure in the vicinity of atmospheric pressure. A transparent laminated film, wherein the gas barrier layer is formed on the transparent support by bringing the reactive gas into a plasma state by discharging and exposing the transparent support to the reactive gas in the plasma state. Production method.
  Note that the following 1 to 9 are means for reference.
[0015]
1. A transparent laminated film having a gas barrier layer on a transparent support, wherein the transparent support is mainly a cellulose ester, and the plasticizer content is less than 1% by mass. .
[0016]
2. 2. The transparent support mainly composed of cellulose ester contains 0 to 20% by mass of metal oxide fine particles composed of a polycondensate of a reactive metal compound capable of hydrolytic polycondensation. Transparent laminated film.
[0017]
3. 3. The transparent laminated film as described in 2 above, wherein the metal oxide fine particles are hydrolysis polycondensates of alkoxysilane represented by the following general formula (1).
[0018]
General formula (1)
R_4-nSi (OR ')_n
(In the formula, R and R ′ represent a hydrogen atom or a monovalent substituent, and n is 3 or 4.)
4). 2. The transparent laminate according to 1 above, wherein the plasticizer is a polyhydric alcohol ester having an aromatic ring or cycloalkyl ring in the molecule or a glycolate plasticizer having an aromatic ring or cycloalkyl ring in the molecule. the film.
[0019]
5). R is the in-plane retardation value at a wavelength of 590 nm.₀(590), the in-plane retardation value at a wavelength of 480 nm is R₀(480), the ratio R₀(480) / R₀The transparent laminated film according to any one of 1 to 4 above, wherein the value of (590) is 0.8 or more and less than 1.0.
[0020]
6). Moisture permeability is 10g / m²/ D or less, The transparent laminated film of any one of said 1-5 characterized by the above-mentioned.
[0021]
7. 7. The transparent laminated film according to any one of 1 to 6, wherein the gas barrier layer is mainly composed of silicon oxide.
[0022]
8). The said transparent support body of any one of said 1-5 is manufactured by the solvent cast method, The manufacturing method of the transparent laminated film characterized by the above-mentioned.
[0023]
9. The method for producing a laminated film according to any one of 1 to 8 above, wherein a reactive gas is discharged by applying a high-frequency voltage between opposing electrodes under atmospheric pressure or pressure near atmospheric pressure. A method for producing a transparent laminated film, wherein the gas barrier layer is formed on a transparent support by exposing the transparent support to a reactive gas in a plasma state.
[0024]
The present invention will be described in detail below.
As a film for an electronic display used for a substrate material such as a liquid crystal display element, a cellulose ester film, in particular, a triacetyl cellulose film is a material having a positive birefringence wavelength dispersion, which is preferable. However, the heat resistance is low, and the linear expansion coefficient peculiar to a plastic substrate is high, so that the substrate material cannot withstand the above requirements.
[0025]
Conventionally, in a cellulose ester film, a plasticizer such as triphenyl phosphate or diethyl phthalate is mixed and used to suppress brittleness and impart flexibility to the film and to reduce moisture permeability. . The plasticizer imparts flexibility to the cellulose ester, lowers the moisture permeability, reduces the hygroscopic expansion coefficient, and contributes to improving the dimensional stability due to humidity, but at the cost of softening temperature of the cellulose ester film Has been found to be reduced (decrease in heat resistance) and the coefficient of linear expansion has increased, and the present inventors can obtain a material having a very low coefficient of linear expansion by removing the plasticizer from the cellulose ester material. I found out.
[0026]
By removing the plasticizer from the cellulose ester film, it is possible to achieve a significant improvement in the coefficient of linear expansion as well as heat resistance. However, triacetyl cellulose containing no plasticizer has high moisture permeability as described above, and moisture. For example, when this is used as a substrate, the life of elements sensitive to moisture (such as organic EL elements) cannot be maintained, and dimensional stability under high humidity However, simply removing the plasticizer from the cellulose ester does not have sufficient characteristics as a display film.
[0027]
Usually, in order to satisfy both moisture permeability and dimensional stability, an appropriate amount of plasticizer is mixed and adjusted to an appropriate level.
[0028]
The inventors of the present invention have the disadvantage of a triacetyl cellulose film without a plasticizer by laminating a gas barrier layer against water or oxygen, etc., separately on these films whose linear expansion coefficient is reduced except for the plasticizer. It has been found that a certain large moisture permeability and a large hygroscopic expansion can be greatly improved and improved to a level not obtainable with a normal cellulose ester film.
[0029]
According to this method, the linear expansion coefficient is lower than that of a general plastic material, and the moisture permeability is greatly improved. Further, the plasticizer generated from the film itself at high temperature and high humidity and its decomposition Because there is no gas or the like derived from an object, coloring of the substrate and damage to the organic EL element and the like are reduced.
[0030]
As a result, a resin film preferable as the display film having a low linear expansion coefficient, low moisture permeability, and low hygroscopic expansion coefficient could be obtained.
[0031]
Here, the measurement of the linear expansion coefficient of film material can be implemented with reference to the method prescribed | regulated by JISK7197, for example. For example, if the temperature of the film material increases once and the dimensions expand by 0.001 mm (1 μm) per meter, the thermal expansion coefficient of the support tray will be 1 ppm.
[0032]
Triacetyl cellulose (substitution degree 2.88) formed by adding 5% by mass of a plasticizer (for example, EPEG (ethylphthalyl ethyl glycolate) described later), and 3% by mass and 1% by mass, Also, a triacetyl cellulose film that does not contain at all is formed, and thermal stress strain measurement is performed. The results of measuring the linear expansion coefficient of each film over temperature are shown in FIG.
[0033]
For thermal stress strain measurement, a TMA-SS6100 manufactured by Seiko Instruments Inc. was used, a sample with a thickness of 100 μm and a width of 4 mm was fixed at a distance between chucks of 20 mm, and after raising the temperature from room temperature to 180 ° C., residual strain was removed. From room temperature to 5 ° C./min. The temperature was raised to 250 ° C., a temperature-strain curve was taken, and the linear expansion coefficient was obtained from the elongation of the distance between chucks based on JIS K7197. In FIG. 1, the slope of each temperature-strain curve in thermal stress strain measurement corresponds to the linear expansion coefficient. It can be seen that as the amount of plasticizer decreases, the coefficient of linear expansion suddenly decreases and improves. In particular, the content of 5% is 91 ppm / ° C., and the content of 3% is changed so much.
[0034]
Accordingly, the plasticizer used in the acetyl cellulose as the transparent support constituting the transparent laminated film according to the present invention is preferably 1% by mass or less, and more preferably not, relative to the whole film.
[0035]
In addition, as described above, since the plastic substrate generally has higher moisture permeability than the glass substrate, it is known to provide a layer (moisture-proof film; barrier layer) that suppresses moisture permeation of the plastic substrate. By removing the plasticizer usually used from the cellulose ester film according to the present invention, the above-mentioned linear expansion coefficient can be achieved. Furthermore, by providing the above-mentioned gas barrier layer, a low level of permeability is achieved along with a low linear expansion coefficient. It was surprising that wettability was achieved and that the coloration of the substrate under a high humidity atmosphere was improved.
[0036]
When a gas barrier layer is provided on a transparent support made of a cellulose ester film excluding a plasticizer to form a laminated film, the moisture permeability is 10 g / m.²/ D or less is achieved, and the hygroscopic expansion coefficient is also small.
[0037]
The moisture permeability of the cellulose ester film can be measured according to the method described in JIS Z 0208, but is usually 20 to 800 g / m at 40 ° C. and 90% RH.²-It is the range of d.
[0038]
Therefore, the display film according to the present invention is a transparent laminated film having a gas barrier layer on a transparent support, wherein the transparent support is mainly a cellulose ester, and the plasticizer content is 1% by mass. It is the transparent laminated film which is the following.
[0039]
The cellulose ester may be triacetyl cellulose or a mixed fatty acid cellulose ester with an acetyl group, a propionyl group, or a butyryl group, and the total substitution degree (total substitution degree) of the total acyl group exceeds 1.5. Cellulose esters are preferably used.
[0040]
The glucose unit forming cellulose has three hydroxyl groups that can be bonded. For example, in cellulose triacetate, when all three hydroxyl groups of the glucose unit are bonded to acetyl groups, the degree of substitution with acetyl groups Is 3.0.
[0041]
The measuring method of the substitution degree of these acyl groups can be measured according to ASTM-D817-96.
[0042]
These acyl groups may be substituted on the 2nd, 3rd and 6th positions of the glucose unit on average, for example, substituted with a distribution such as substitution at a high ratio at the 6th position. Also good.
[0043]
Cellulose ester is preferred as a resin having a positive birefringence wavelength dispersion characteristic. Since cellulose ester has hydroxyl groups, cellulose ester can be obtained by substituting these hydroxyl groups with the alkoxysilane or polycondensate thereof. As a skeleton, a transparent film having low heat resistance and low birefringence, positive wavelength dispersion of birefringence and high heat resistance can be formed.
[0044]
The wavelength dispersion of birefringence is positive dispersion. For example, a film is prepared by dissolving the polymer in a soluble solvent and casting and drying on a glass plate so that the thickness when the film is dried is 100 μm. In-plane retardation value R of the polymer film at a wavelength of 480 nm₀(480) in-plane retardation value R at a wavelength of 590 nm₀The value divided by (590) is smaller than 1.
[0045]
In the transparent support used for the laminated film of the present invention, the in-plane retardation value R at the wavelength of 480 nm.₀(480) in-plane retardation value R at a wavelength of 590 nm₀Value divided by (590), R₀(480) / R₀(590) is preferably 0.8 or more and less than 1.0.
[0046]
In transparent films with positive birefringence wavelength dispersion, polarization can be compensated in the entire visible wavelength range, and there is no color shift in liquid crystal panels that employ a birefringence display method, and organic The EL display element has good contrast.
[0047]
In addition to the aforementioned additives, the transparent film in the present invention may contain fine particles (matting agent) that impart slipperiness to the film, a retardation adjusting agent that adjusts the retardation of the film, and the like.
[0048]
The raw material cellulose of the cellulose derivative used in the present invention is not particularly limited, and examples thereof include cotton linter, wood pulp, and kenaf. Moreover, although the cellulose derivative obtained from these can be used individually or in mixture of arbitrary ratios, it is preferable to use 50 mass% or more of cotton linters.
[0049]
The molecular weight of the cellulose derivative is preferably 70,000 to 200,000 in terms of number average molecular weight (Mn) from the viewpoint of the elastic modulus of the film obtained, the viscosity of the dope and the film forming speed, and is preferably 100,000 to 200,000. Are more preferred. The cellulose derivative used in the present invention has an Mw / Mn ratio of less than 3.0, preferably 1.4 to 2.3.
[0050]
Since the average molecular weight and molecular weight distribution of the cellulose derivative can be measured using high performance liquid chromatography, the number average molecular weight (Mn) and the weight average molecular weight (Mw) can be calculated using this, and the ratio can be calculated.
[0051]
The measurement conditions are as follows.
Solvent: Methylene chloride
Column: Shodex K806, K805, K803G (used by connecting three Showa Denko Co., Ltd.)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corp.) Mw = 100000-500 calibration curves with 13 samples were used. The 13 samples are preferably used at approximately equal intervals.
[0052]
The cellulose ester used in the present invention can be synthesized using an acid anhydride or acid chloride as an acylating agent. When the acylating agent is an acid anhydride, an organic acid (for example, acetic acid) or methylene chloride is used as a reaction solvent. As the catalyst, an acidic catalyst such as sulfuric acid is used. When the acylating agent is an acid chloride, a basic compound is used as a catalyst. In the most general synthetic method in industry, cellulose is esterified with a mixed organic acid component containing an organic acid corresponding to an acetyl group (acetic acid, propionic acid) or an acid anhydride thereof (acetic anhydride, propionic anhydride). A cellulose ester is synthesized. When other acylating agents are used in combination, for example, the amount of the propionylating agent corresponding to the propionyl group is adjusted so that the ester to be synthesized falls within the range of the required degree of substitution. The amount of the reaction solvent used is preferably 100 to 1000 parts by mass, more preferably 200 to 600 parts by mass with respect to 100 parts by mass of cellulose. It is preferable that the usage-amount of an acidic catalyst is 0.1-20 mass parts with respect to 100 mass parts of cellulose, More preferably, it is 0.4-10 mass parts.
[0053]
The reaction temperature is preferably 10 to 120 ° C, more preferably 20 to 80 ° C. Further, after completion of the acylation reaction, the degree of substitution may be adjusted by hydrolysis (saponification) as necessary. After completion of the reaction, the cellulose ester is obtained by separating the reaction mixture using a conventional means such as precipitation, washing and drying.
[0054]
A solution in which a cellulose ester is dissolved in an organic solvent such as methylene chloride, methyl acetate or methanol or ethanol at a concentration of 10 to 35% by mass (more preferably 15 to 25% by mass) is referred to as a dope. Additives such as plasticizers and UV inhibitors are further added to the dope solution obtained by dissolution, and the dope solution is cast on a support (support with a mirror-finished belt-like or drum-like stainless steel). (Casting process) After heating, part of the solvent is removed (drying process on support), then peeled off from the support, and the peeled film is dried (film drying process). The cellulose ester film is obtained by stretching in the direction or TD direction. Here, the MD direction indicates the film forming direction of the film during casting film formation, and the TD direction indicates the width direction of the film during casting film formation.
[0055]
The content of the plasticizer such as EPEG in the cellulose ester can be adjusted by the amount added to the dope solution.
[0056]
Examples of the plasticizer that can be used in the present invention include polyhydric alcohol ester plasticizers, glycolate plasticizers, phosphate ester plasticizers, and phthalate ester plasticizers. Preferably, there are various plasticizers such as a polyhydric alcohol plasticizer and a glycolate plasticizer, but a polyhydric alcohol ester plasticizer, particularly an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid, A polyhydric alcohol ester plasticizer having an aromatic ring or a cycloalkyl ring in the molecule is preferred.
[0057]
The polyhydric alcohol used in the present invention is represented by the following general formula (1).
General formula (2)
R₁-(OH)_n
Where R₁Represents an n-valent organic group, n represents a positive integer of 2 or more, and an OH group represents an alcoholic and / or phenolic hydroxyl group.
[0058]
Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these. Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, and xylitol. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.
[0059]
There is no restriction | limiting in particular as monocarboxylic acid used for the polyhydric alcohol ester concerning this invention, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.
[0060]
Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.
[0061]
As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1-20, and particularly preferably 1-10. When acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.
[0062]
Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid, tridecylic acid , Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, Examples thereof include unsaturated fatty acids such as oleic acid, sorbic acid, linoleic acid, linolenic acid and arachidonic acid.
[0063]
Examples of preferable alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.
[0064]
Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. The aromatic monocarboxylic acid which has, or those derivatives can be mentioned. Benzoic acid is particularly preferable.
[0065]
The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably 300 to 1500, and more preferably 350 to 750. A higher molecular weight is preferred because it is less likely to volatilize, and a smaller one is preferred in terms of moisture permeability and compatibility with cellulose ester.
[0066]
The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.
[0067]
Below, the specific compound of a polyhydric alcohol ester is illustrated.
[0068]
[Chemical 1]

[0069]
[Chemical formula 2]

[0070]
[Chemical 3]

[0071]
[Formula 4]

[0072]
The glycolate plasticizer is not particularly limited, but a glycolate plasticizer having an aromatic ring or a cycloalkyl ring in the molecule can be preferably used. As preferred glycolate plasticizers, for example, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate and the like can be used.
[0073]
For phosphate plasticizers, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenylbiphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. For phthalate ester plasticizers, diethyl phthalate, dimethoxy Ethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dicyclohexyl phthalate and the like can be used.
[0074]
These plasticizers can be used in combination of two or more.
You may add additives, such as a ultraviolet absorber, dye, and a mat agent, to the cellulose-ester film of this invention as needed.
[0075]
The ultraviolet absorber is excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and has a good liquid crystal display property from the viewpoint of preventing deterioration of the liquid crystal in an outdoor environment where the liquid crystal display device is exposed to sunlight or the like. Therefore, those having little absorption of visible light having a wavelength of 400 nm or more are preferably used. In the present invention, the transmittance at a wavelength of 370 nm is particularly preferably 10% or less, more preferably 5% or less, and further preferably 2% or less.
[0076]
In the present invention, an ultraviolet absorber having two or more aromatic rings in the molecule is particularly preferably used.
[0077]
Although the ultraviolet absorber used in the present invention is not particularly limited, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, inorganic powders Examples include the body. Preferably used UV absorbers are benzotriazole UV absorbers and benzophenone UV absorbers, which are highly transparent and excellent in preventing the deterioration of polarizing plates and liquid crystal elements, and have less unnecessary coloration. UV absorbers are particularly preferred. Specific examples of the ultraviolet absorber used in the present invention include, for example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazole -2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, tinuvin 109, tinuvin 171, tinuvin 234, tinuvin Tinuvin such as 326, bottle 327 and tinuvin 328 are all commercially available from Ciba Specialty Chemicals and can be preferably used.
[0078]
The ultraviolet absorber may be a mixture of two or more.
As the UV absorber, a polymer UV absorber can be preferably used, and in particular, a polymer type UV absorber described in JP-A-6-148430 is preferably used.
[0079]
As a method for adding the ultraviolet absorber, the ultraviolet absorber may be dissolved in an organic solvent such as alcohol, methylene chloride, dioxolane, etc. and then added to the dope, or may be added directly into the dope composition. For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and cellulose ester to disperse and then added to the dope.
[0080]
The amount of the UV absorber used is not uniform depending on the type of compound, use conditions, etc., but when the cellulose ester film has a dry film thickness of 30 to 200 μm, it acts as a plasticizer if it is too much. The range in which the expansion coefficient does not deteriorate, that is, less than 1% by mass is preferable as with the plasticizer.
[0081]
In addition, antioxidants, anthraquinone dyes for color adjustment, and the like can also be added.
[0082]
You may add fine particle mat agents, such as silicon oxide, and mat agent fine particles, such as silicon oxide surface-treated with organic substance.
The larger the average diameter of the fine particles, the greater the mat effect, and the smaller the average diameter, the better the transparency. Therefore, the average diameter of the primary particles of the fine particles is preferably 5 to 50 nm, more preferably 7 to 20 nm.
[0083]
Although it does not specifically limit as a microparticles | fine-particles of a silicon oxide, For example, Nippon Aerosil Co., Ltd. AEROSIL (Aerosil) 200, 200V, 300, R972, R972V, R972CF, R974, R202, R805, R812, OX50, TT600 etc. are mentioned. AEROSIL (Aerosil) 200, 200V, R972, R972V, R974, R202, R805, R812 are preferred.
[0084]
Various additives may be batch-added to the dope, or an additive solution may be separately prepared and added in-line. In particular, it is preferable to add a part or all of the matting agent in-line in order to reduce the load on the filter medium.
[0085]
When the additive solution is added in-line, it is preferable to dissolve a small amount of cellulose ester in order to improve mixing with the dope. A preferable amount of the cellulose ester is 1 to 10 parts by mass, and more preferably 3 to 5 parts by mass with respect to 100 parts by mass of the solvent.
[0086]
In order to perform in-line addition and mixing in the present invention, for example, an in-line mixer such as a static mixer (manufactured by Toray Engineering), SWJ (Toray static type in-tube mixer Hi-Mixer) or the like is preferably used.
[0087]
Further, the transparent support mainly composed of the cellulose ester film in the laminated film according to the present invention further comprises 0 to 20% by mass of metal oxide fine particles comprising a polycondensate of a reactive metal compound capable of condensation during hydrolysis. More preferably, it is contained.
[0088]
Moreover, it is preferable that the said metal oxide fine particle is a hydrolysis polycondensate of the alkoxysilane represented by the said General formula (1).
[0089]
When these organic-inorganic hybrid cellulose ester resins are used, the display film according to the present invention has more preferable characteristics.
[0090]
In the general formula (1), R ′ represents an alkyl group, R represents a hydrogen atom or a monovalent substituent, and n represents 3 or 4.
[0091]
Examples of the alkyl group represented by R ′ include groups such as a methyl group, an ethyl group, a propyl group, and a butyl group, which may have a substituent, and the substituent exhibits properties as an alkoxysilane. If it is, there is no restriction | limiting in particular, For example, although it may be substituted by the halogen atom, the alkoxy group, etc., More preferably, it is an unsubstituted alkyl group, and especially a methyl group and an ethyl group are preferable.
[0092]
The monovalent substituent represented by R may be a compound exhibiting properties as an alkoxysilane, and specifically includes an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aromatic heterocyclic group, a silyl group. Group and the like. Of these, an alkyl group, a cycloalkyl group, and an alkenyl group are preferable. These may be further substituted. Examples of the substituent of R include various substituents that do not impair the properties of alkoxysilane, such as halogen atoms such as fluorine atom and chlorine atom, amino group, epoxy group, mercapto group, hydroxyl group, and acetoxy group.
[0093]
Specific preferred examples of the alkoxysilane represented by the general formula (1) include tetramethoxysilane, tetraethoxysilane (TEOS), tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane, tetra t-butoxysilane, tetrakis (methoxyethoxy) silane, tetrakis (methoxypropoxy) silane,
Further, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, n-hexyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3 -Mercaptopropyltrimethoxysilane, acetoxytriethoxysilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trimethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, (3, 3, - trifluoropropyl) trimethoxysilane, pentafluorophenyl phenylpropyl trimethoxysilane,
Furthermore, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane and the like can be mentioned.
[0094]
In addition, a quantification silicon compound such as silicate 40, silicate 45, silicate 48, and M silicate 51 manufactured by Tama Chemical, in which these compounds are partially condensed may be used.
[0095]
Since the alkoxysilane has a silicon alkoxide group capable of hydrolytic polycondensation, a network structure of a polymer compound is formed by hydrolytic polycondensation of these alkoxysilanes. By condensing the decomposed polycondensate with the cellulose ester, a transparent film having a dense cross-linked structure of the organic polymer component composed of the cellulose ester and the fine particle component formed by hydrolytic polycondensation of alkoxysilane is obtained.
[0096]
Specifically, a hydrophilic organic solvent such as methanol, ethanol, or acetonitrile is added together so that water or an organometallic compound and water can be easily mixed with hydrophobic alkoxysilane, and a catalyst is added if necessary. The alkoxysilane is hydrolyzed and polycondensed, and the hydrolyzed polycondensate is condensed with the cellulose ester by adding and mixing the cellulose ester dope.
[0097]
By using the transparent film as a transparent support, the heat resistance is further improved without losing the optical properties of the cellulose ester, the linear expansion coefficient is further reduced, and the moisture permeability is further improved by combining with the barrier layer. Thus, a laminated film having a low coefficient of linear expansion is obtained which is not easily deformed even under high temperature and high humidity conditions.
[0098]
The fine particle component comprising the hydrolysis polycondensation product of the cellulose ester and the alkoxysilane represented by the general formula (1) preferably represents 80% or more of the transparent film support, more preferably 90% by mass ratio. % Or more. In addition to the main components, additives such as a plasticizer and a matting agent as described later may be contained.
[0099]
Moreover, as a cellulose ester used in the transparent film whose main component is a condensate fine particle during hydrolysis of cellulose ester and alkoxysilane, it is the cellulose ester, and acetyl cellulose is particularly preferable. In addition, cellulose ester that employs cellulose with an alkoxysilyl group is also preferably used. When the substitution degree with an acetyl group is represented by X and the substitution degree by a functional group having an alkoxysilyl group is represented by Y, the following formula (1), It is preferable that the cellulose ester satisfies (2).
[0100]
Formula (1) 0 <= Y <= 1.5
Formula (2) 1.0 <X + Y ≦ 2.9
This is because X + Y in the range of 1.0 or more and 2.9 or less has high resin solubility, and a high-concentration dope (a solution in which a resin is dissolved in a solvent is hereinafter referred to as a dope) can be produced. This is because it is more advantageous during drying. Moreover, you may substitute by the alkoxysilyl group which can perform a condensation reaction with the hydrolysis polycondensate of alkoxysilane. However, Y is preferably 1.5 or less in order to avoid the network structure of the transparent film becoming too dense and becoming a fragile film.
[0101]
The measuring method of the substitution degree of these acyl groups can be measured according to ASTM-D817-96 as described above.
[0102]
As the cellulose as a raw material of the cellulose derivative used in these composite films, the same ones as described above are used. The same applies to the Mw / Mn ratio (showing molecular weight distribution) when the number average molecular weight of the cellulose derivative is (Mn) and the weight average molecular weight is (Mw).
[0103]
As the content of the organometallic compound (alkoxysilane hydrolyzed polycondensate) in the transparent film, the hydrolysis polycondensate of the alkoxysilane represented by the general formula (1) is completely hydrolyzed. And the total mass of the inorganic polymer compound represented by the general formula (2) is, as described above, the total mass of the transparent film. 0-20 mass% is preferable with respect to.
[0104]
General formula (2) R_4-nSiO_{n / 2}
In the formula, R represents a hydrogen atom or a monovalent substituent, and n is 3 or 4. Here, R has the same meaning as in general formula (1).
[0105]
In order to prevent the transparent film from being softened at a high temperature, the addition amount of the organometallic compound is 1% by mass or more, and the network structure of the transparent film is too dense to avoid becoming a fragile film. The addition amount of the organometallic compound is 20% by mass or less of the transparent film.
[0106]
<Hydrolysis catalyst>
In the transparent film of the present invention, the alkoxysilane represented by the general formula (1) may promote hydrolysis by adding water and a catalyst as necessary to cause hydrolysis.
[0107]
However, from the viewpoint of productivity such as film haze, flatness, film-forming speed, and solvent recycling, the water content is preferably within the range of 0.01% by mass to 2.0% by mass of the dope concentration.
[0108]
When water is added to the hydrophobic alkoxysilane, it is preferable that a hydrophilic organic solvent such as methanol, ethanol, or acetonitrile coexists so that the organometallic compound and water can be easily mixed. Moreover, when adding alkoxysilane or its hydrolysis polycondensate to the dope of the cellulose ester, it is preferable that a good solvent for the cellulose ester is also included so that the cellulose ester does not precipitate from the dope.
[0109]
Examples of the catalyst include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, 12 tungsto (VI) phosphoric acid, 12 molybdo (VI) phosphoric acid, silicotungstic acid and other inorganic acids, acetic acid, trifluoroacetic acid, levulinic acid, citric acid, Organic acids such as p-toluenesulfonic acid and methanesulfonic acid are used. After the sol-gel reaction has progressed by adding an acid, it may be neutralized by adding a base. When neutralizing by adding a base, the content of alkali metal before the drying step is preferably less than 5000 ppm (herein, the alkali metal includes those in an ionic state). In addition, Lewis acids such as acetates of metals such as germanium, titanium, aluminum, antimony and tin, other organic acid salts, halides and phosphates may be used in combination.
[0110]
Further, as a catalyst, instead of such acids, ammonia, monoethanolamine, diethanolamine, triethanolamine, diethylamine, triethylamine and the like, bicyclo such as DBU (diazabicycloundecene-1) and DBN (diazabicyclononene) are used. Bases such as ring amine, ammonia, phosphine, alkali metal alkoxide, ammonium hydroxide, tetramethylammonium hydroxide, benzyltrimethylammonium hydroxide can be used.
[0111]
The amount of the acid or alkali catalyst added is not particularly limited, but is preferably 0.01% to 20% by mass with respect to the amount of the reactive metal compound capable of polycondensation. Moreover, you may use together the process of an acid and a base in multiple times. The catalyst may be neutralized, or the volatile catalyst may be removed under reduced pressure, or may be removed by separation water washing or the like. A solid catalyst such as an ion exchange resin that can be easily removed may be used.
[0112]
In the hydrolysis polycondensation of alkoxysilane, the reaction may be completed in a solution state before coating, or the reaction may be completed after casting into a film, but the reaction may be completed before coating. good. Depending on the application, the reaction does not have to be completed completely, but it should be completed if possible.
[0113]
<solvent>
The production of a film (transparent support) mainly composed of a cellulose-silica hybrid polymer mainly comprising a hydrolysis polycondensate of cellulose ester and alkoxysilane according to the present invention is carried out in the same manner as in the cellulose ester film, for example, acetyl An alkoxysilane formed from the above alkoxysilane or its hydrolyzed polycondensate is added to cellulose, and both are dissolved in a solvent to form a dope, which is then cast onto a substrate (belt-shaped or drum-shaped stainless steel as a mirror surface). A dope solution can be cast (casting process) on a finished support) to form a film.
[0114]
As a solvent for dissolving these acetylcellulose and the alkoxysilane or its hydrolyzed polycondensate, a volatile solvent is preferable like acetylcellulose, and it does not react with a catalyst, alkoxysilane, etc., and it is a base material for casting. Those which do not dissolve are preferred. Two or more of these solvents may be mixed and used. Moreover, in manufacture of a cellulose-silica hybrid polymer, you may mix, after melt | dissolving a cellulose ester and alkoxysilane in another solvent, respectively.
[0115]
In this way, basically, in the same manner as in the formation of a cellulose ester film, a cellulose-silica hybrid is prepared by adding these alkoxysilanes or their hydrolysis polycondensates to a cellulose ester solution (dope) to produce a dope. A polymer can be produced.
[0116]
Here, hereinafter, an organic solvent having good solubility with respect to the cellulose ester is referred to as a good solvent, and has a main effect on dissolution, and an organic solvent used in a large amount among them is a main (organic) solvent or a main solvent. It is called (organic) solvent.
[0117]
Examples of good solvents include ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethers such as tetrahydrofuran (THF), 1,4-dioxane, 1,3-dioxolane, 1,2-dimethoxyethane, and formic acid. In addition to esters such as methyl, ethyl formate, methyl acetate, ethyl acetate, amyl acetate, and γ-butyrolactone, methyl cellosolve, dimethylimidazolinone, dimethylformamide, dimethylacetamide, acetonitrile, dimethylsulfoxide, sulfolane, nitroethane, chloride Examples include methylene and the like, and 1,3-dioxolane, THF, methyl ethyl ketone, acetone, methyl acetate and methylene chloride are preferable.
[0118]
The dope preferably contains 1 to 40% by mass of an alcohol having 1 to 4 carbon atoms in addition to the organic solvent. After casting the dope on the metal support, the solvent starts to evaporate and the alcohol ratio increases, so that the web (referred to as the dope film after casting the cellulose derivative dope on the support is called web )), And it is used as a gelling solvent to make the web strong and easy to peel off from the metal support. When these ratios are small, the dissolution of cellulose derivatives of non-chlorine organic solvents is promoted. There is also a role to suppress gelation, precipitation, and viscosity increase of the reactive metal compound.
[0119]
Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol, and propylene glycol monomethyl ether. Of these, ethanol is preferred because it has excellent dope stability, has a relatively low boiling point, good drying properties, and no toxicity. These organic solvents alone are not soluble in cellulose derivatives and are called poor solvents.
[0120]
The most preferable solvent that satisfies such conditions and dissolves the cellulose ester derivative, which is a preferable polymer compound, at a high concentration is a mixed solvent having a ratio of methylene chloride: ethyl alcohol of 95: 5 to 80:20.
[0121]
In the casting (casting process), the dope is fed to a pressure die and transferred onto an endless metal belt or a rotating metal drum casting support (hereinafter also simply referred to as a support). This is a step of casting a dope from a pressure die. The surface of the casting support is a mirror surface. Other casting methods include a doctor blade method that uses a blade to adjust the film thickness of the cast dope film, but the coat hanger die and T-die can easily adjust the slit shape of the die and make the film thickness uniform. A pressure die such as is preferred.
[0122]
In order to evaporate the solvent by heating the web (the name of the dope film after casting the dope on the casting support is referred to as the web) on the casting support, air is blown from the web side. There are a method or a method of transferring heat from the back surface of the support by a liquid, a method of transferring heat from the front and back by radiant heat, and the like. A method of combining them is also preferable.
[0123]
After the web in which the solvent has evaporated on the support is peeled off at the peeling position, the peeled web is sent to the next step. If the residual solvent amount of the web at the time of peeling is too large, peeling is difficult, or conversely, if the film is peeled off after sufficiently drying on the support, part of the web is peeled off.
[0124]
As a method for increasing the film forming speed, there is a gel casting method (gel casting) in which even a large amount of residual solvent can be peeled off. There are a method in which a poor solvent for cellulose ester is added to the dope and the dope is cast and then gelled, a method in which the temperature of the support is lowered and gelled. When peeling at a time when the amount of residual solvent is larger, if the web is too soft, the flatness at the time of peeling tends to be lost, or slippage and vertical stripes are likely to occur due to peeling tension. It is decided.
[0125]
Drying is a process of drying the web using a drying device that alternately conveys the web through rolls arranged in a staggered manner, or a tenter device that clips and conveys both ends of the web with a clip. In general, hot air is blown on both sides, but there is also a means of heating by applying a microwave instead of the wind. Too rapid drying tends to impair the flatness of the film. Drying at a high temperature is preferably performed from about 8% by mass or less of the residual solvent. Throughout, the drying temperature is usually 40 to 250 ° C, preferably 70 to 180 ° C. The drying temperature, the amount of drying air, and the drying time differ depending on the solvent used, and the drying conditions may be appropriately selected according to the type and combination of the solvents used.
[0126]
In the drying step after peeling from the casting support surface, the web tends to shrink in the width direction due to evaporation of the solvent. Shrinkage increases as the temperature rapidly dries. Drying while suppressing this shrinkage as much as possible is preferable for improving the flatness of the finished film. From this point of view, for example, a method of drying the entire drying process or a part of the process as shown in JP-A-62-46625 while holding the width at both ends of the web with a clip in the width direction (tenter method) Is preferred.
[0127]
The web is wound up as a film after the amount of residual solvent is 2% or less, preferably 0.4% or less. As a winding method, a generally used method may be used. There are a constant torque method, a constant tension method, a taper tension method, a program tension control method with a constant internal stress, and the like.
[0128]
To adjust the film thickness of the film obtained, the dope concentration, the pumping amount, the slit gap of the die base, the die extrusion pressure, and the speed of the casting support are controlled so as to obtain the desired thickness. Is good. Further, as a means for making the film thickness uniform, it is preferable to use a film thickness detection means to feed back and adjust the programmed feedback information to each of the above devices.
[0129]
Therefore, the display film according to the present invention does not have these plasticizers or is laminated on a cellulose ester film containing less than 1% by mass with respect to the cellulose ester, or a gas barrier layer against water, water vapor, etc. It is a transparent laminated film. The gas barrier film may be formed by being laminated on one side or may be formed on both sides.
[0130]
As the gas barrier layer, a film containing a metal oxide, metal nitride or metal oxynitride is preferably mentioned, and this does not contain the plasticizer which is a base film or contains 1% by mass or less of cellulose. By laminating on the ester film, a film for display suitable as a substrate material or the like having a low linear expansion coefficient and low water permeability can be obtained.
[0131]
In the present invention, the phrase “containing a metal oxide, metal nitride, or metal oxynitride” means having this as a main component, that is, 80% or more of all constituent components are metal oxide, metal nitride, or metal. This means that oxynitride is occupied.
[0132]
The metal oxide, metal nitride, or metal oxynitride used in such a film is at least one selected from silicon, zirconium, titanium, tungsten, tantalum, aluminum, zinc, indium, chromium, vanadium, tin, and niobium. Examples include oxides, nitrides, and oxynitrides of elements. More specifically, metal oxides such as silicon oxide, titanium oxide, tin oxide, and alumina, metal nitrides such as silicon nitride, silicon oxynitride, and acid Metal oxynitrides such as titanium nitride. Particularly preferred is a metal oxide film in which silicon oxide is the main component. The main component means that the ratio in the moisture-proof film component is 80% by mass or more.
[0133]
A film containing a metal oxide, nitride, or oxynitride may be formed by any method such as a method of applying a solution called a sol-gel method, vacuum deposition, sputtering, or CVD (chemical vapor deposition). However, it is preferably formed by a method using plasma processing at or near atmospheric pressure described later. That is, the atmospheric pressure plasma method in which a metal film is formed on a base film by exposing the base film to a reactive gas in a plasma state between opposing electrodes using an organometallic compound as a reactive gas, It is preferable because the physical properties of the film can be controlled by the fact that it can be formed, the selection of the reactive gas, and the plasma generation conditions.
[0134]
Although silicon oxide has high transparency, it is preferable to contain a nitrogen atom in order to further improve the gas barrier properties such as moisture. As the nitrogen source, silazane, nitrogen gas, or the like described later can be used. However, if the nitrogen ratio is increased, the barrier property is enhanced. However, since the light transmittance is decreased, when the substrate requires light transmittance, for example, silicon oxynitride or titanium oxynitride is used. If SiO_xN_yTiO_xN_yIn terms of the composition, x and y are preferably set to values that satisfy the following expression, and used in a region where the light transmittance is not significantly reduced.
[0135]
0.4 ≦ x / (x + y) ≦ 0.8
For example, when x = 0, that is, SiN hardly transmits light. The ratio of oxygen atoms and nitrogen atoms can be measured using XPS (ESCACAB-200R manufactured by VG Scientific).
[0136]
Since the moisture permeability is particularly low, silicon oxide is preferable as the main component of the film containing metal oxide or nitride.
[0137]
A film containing these metal oxides or nitrides is a reactive gas containing an inert gas and a metal compound gas such as an organometallic compound or a metal hydride compound by a plasma CVD method under atmospheric pressure or a pressure in the vicinity thereof. It is preferable to form on a base film using.
[0138]
A compound such as an organic metal compound, such as a metal hydride compound, may be in a gas, liquid, or solid state at normal temperature and pressure, but in the case of a gas, it can be introduced into the discharge space as it is. In this case, it is used after being vaporized by means of heating, decompression, ultrasonic irradiation or the like. Moreover, you may dilute and use with a solvent and organic solvents, such as methanol, ethanol, n-hexane, and these mixed solvents can be used for a solvent. Since these diluted solvents are decomposed into molecular and atomic forms during the plasma discharge treatment, the influence can be almost ignored.
[0139]
As the organometallic compound, there is no generation of corrosive and harmful gas in order to form the silicon oxide film, and since there is little contamination in the process, for example, it is represented by the following general formulas (I) to (V). Are preferred.
[0140]
[Chemical formula 5]

[0141]
Where R_{twenty one}To R₂₆Represents a hydrogen atom or a monovalent group. n1 represents a natural number.
[0142]
Examples of the compound represented by the general formula (I) include hexamethyldisiloxane (HMDSO), tetramethyldisiloxane (TMDSO), 1,1,3,3,5,5-hexamethyltrisiloxane and the like. It is done.
[0143]
[Chemical 6]

[0144]
Where R₃₁And R₃₂Represents a hydrogen atom or a monovalent group. n2 represents a natural number.
[0145]
Examples of the compound represented by the general formula (II) include hexamethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and the like.
[0146]
General formula (III)
(R₄₁)_nSi (R₄₂)_4-n
Where R₄₁And R₄₂Represents a hydrogen atom or a monovalent group. n represents an integer from 0 to 3.
[0147]
Examples of the organosilicon compound represented by the general formula (III) include tetraethoxysilane (TEOS), methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, Methoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, n-hexyltrimethoxysilane, phenyltrimethoxysilane, vinyl Examples include trimethoxysilane and vinyltriethoxysilane.
[0148]
[Chemical 7]

[0149]
In the formula, A represents a single bond or a divalent group. R₅₁~ R₅₅Each independently represents a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aromatic heterocyclic group, an amino group or a silyl group. R₅₁And R₅₂, R₅₄And R₅₅May be condensed to form a ring.
[0150]
In the general formula (IV), A is preferably a single bond or a divalent group having 1 to 3 carbon atoms. R₅₄And R₅₅May be condensed to form a ring, and examples of the ring formed include a pyrrole ring, a piperidine ring, a piperazine ring, and an imidazole ring. R₅₁~ R₅₃Is preferably a hydrogen atom, a methyl group or an amino group.
[0151]
Examples of the compound represented by the general formula (IV) include aminomethyltrimethylsilane, dimethyldimethylaminosilane, dimethylaminotrimethylsilane, allylaminotrimethylsilane, diethylaminodimethylsilane, 1-trimethylsilylpyrrole, 1-trimethylsilylpyrrolidine, isopropylamino. Methyltrimethylsilane, diethylaminotrimethylsilane, anilinotrimethylsilane, 2-piperidinoethyltrimethylsilane, 3-butylaminopropyltrimethylsilane, 3-piperidinopropyltrimethylsilane, bis (dimethylamino) methylsilane, 1-trimethylsilylimidazole Bis (ethylamino) dimethylsilane, bis (dimethylamino) dimethylsilane, bis (butylamino) dimethylsilane, 2-amino Tylaminomethyldimethylphenylsilane, 3- (4-methylpiperazinopropyl) trimethylsilane, dimethylphenylpiperazinomethylsilane, butyldimethyl-3-piperazinopropylsilane, dianilinodimethylsilane, bis (dimethylamino) And diphenylsilane.
[0152]
In the general formula (IV), particularly preferred compounds are those represented by the general formula (V).
[0153]
[Chemical 8]

[0154]
Where R₆₁To R₆₆Each independently represents a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aromatic heterocyclic group.
[0155]
R in general formula (V)₆₁To R₆₆Is preferably a hydrocarbon group having 1 to 10 carbon atoms from the viewpoint of easiness of vaporization, more preferably R.₆₁To R₆₃At least two of them and R₆₄To R₆₆At least two of them are methyl groups.
Examples of the compound represented by the general formula (V) include 1,1,3,3-tetramethyldisilazane and 1,3-bis (chloromethyl) -1,1,3,3-tetramethyldisilazane. Hexamethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, and the like.
[0156]
In addition, for example, dibutyltin diacetate can be used to form tin oxide.
[0157]
Further, a film containing at least one of an oxygen atom and a nitrogen atom and a metal atom such as silicon or tin can be obtained by combining oxygen gas or nitrogen gas with the organometallic compound at a predetermined ratio.
[0158]
Furthermore, in order to adjust the carbon content in the film, hydrogen gas or the like may be mixed into the mixed gas as described above. For these reactive gases, the 18th group atom of the periodic table, specifically, Helium, neon, argon, krypton, xenon, radon, etc., particularly helium and argon are preferably used. By mixing an inert gas and supplying it as a mixed gas to a plasma discharge generator (plasma generator) Film formation is performed. Although the ratio of the inert gas and the reactive gas varies depending on the properties of the film to be obtained, the reactive gas is supplied with the ratio of the inert gas being 90.0 to 99.9% with respect to the entire mixed gas.
[0159]
By using silazane, a film containing silicon oxynitride (SiON) can be formed.
[0160]
As the Si source, not only the organic silicon compound as described above but also an inorganic silicon compound may be used.
[0161]
In addition to oxygen gas, ozone, carbon dioxide, water (water vapor) or the like may be used as the oxygen source, and ammonia, nitrogen oxide or the like may be used as the nitrogen source in addition to silazane or nitrogen gas.
[0162]
In the present invention, a metal oxide (for example, silica), metal nitride or oxynitride film does not have sufficient moisture sealing ability unless it has a certain thickness. Therefore, the film thickness is preferably 70 nm to 1500 nm, more preferably 100 nm to 1000 nm. Therefore, if it has a certain thickness, it may be formed on the base film by coating using a so-called sol-gel method, and this is effective in that a thick film can be formed at a time.
[0163]
However, it is preferable to form a thick film by the atmospheric pressure plasma method because the film is dense, and in the case of a slightly thick film, it may be produced by a method such as increasing the number of times of plasma treatment, time, etc. preferable.
[0164]
(Plasma film forming equipment)
Various apparatuses can be used for the plasma film forming apparatus for forming a metal oxide (for example, silica) or nitride film on the base film by the atmospheric pressure plasma method. Although it does not matter, examples of preferable plasma film forming apparatuses used for forming a metal oxide (for example, silica) or nitride film on a long base film are shown in FIGS. In the figure, reference numeral F denotes a long film as an example of a substrate for forming a metal oxide (for example, silica) or nitride film.
[0165]
These discharge plasma treatments are performed at or near atmospheric pressure. The vicinity of atmospheric pressure represents a pressure of 20 kPa to 110 kPa as described above, and more preferably 93 kPa to 104 kPa.
[0166]
FIG. 2 is a schematic configuration diagram showing an example of a plasma discharge processing chamber provided in the plasma film forming apparatus. In the plasma discharge treatment chamber 10 of FIG. 2, the base film F is conveyed while being wound around a roll electrode 25 that rotates in the conveying direction (clockwise in the figure). The plurality of fixed electrodes 26 fixed around the roll electrode 25 are each formed of a cylinder, and are installed facing the roll electrode 25.
[0167]
As the discharge vessel 11 constituting the plasma discharge treatment chamber 10, a Pyrex (R) glass treatment vessel is preferably used. However, it is possible to use a metal vessel as long as it is insulated from the electrodes. For example, polyimide resin or the like may be attached to the inner surface of an aluminum or stainless steel frame, and the metal frame may be thermally sprayed to obtain insulation.
[0168]
The base film F wound around the roll electrode 25 is pressed by the nip rollers 15, 15, 16, transported to a discharge processing space regulated by the guide roller 24 and secured in the discharge vessel 11, and subjected to discharge plasma processing. Then, it is conveyed to the next process via the guide roller 27. In the present invention, since a film can be formed by discharge treatment under a pressure close to atmospheric pressure instead of a vacuum system, such a continuous process is possible, and high productivity can be increased.
[0169]
In addition, the partition plates 14 and 14 are disposed in the vicinity of the nip rollers 15, 15, and 16 to suppress the air accompanying the base film F from entering the discharge vessel 11. The entrained air is preferably suppressed to 1% by volume or less, more preferably 0.1% by volume or less, with respect to the total volume of the gas in the discharge vessel 11. This can be achieved by the nip rollers 15 and 16.
[0170]
The mixed gas used for the discharge plasma treatment is introduced into the discharge vessel 11 from the air supply port 12, and the treated gas is exhausted from the exhaust port 13.
[0171]
The roll electrode 25 is a ground electrode, and is discharged between a plurality of fixed electrodes 26 that are application electrodes. A reactive gas as described above is introduced between the electrodes to form a plasma state and is wound around the roll electrode 25. A film derived from a reactive gas is formed by exposing the rotated long base film to the reactive gas in the plasma state.
[0172]
Between the electrodes, it is preferable to supply a certain amount of electric power at a high frequency voltage in order to obtain a high plasma density, increase the film forming speed, and control the carbon content within a predetermined ratio. Specifically, a high frequency voltage of 3 kHz to 13.56 MHz is preferably applied, more preferably 10 kHz or more, further preferably 50 kHz or more, and even more preferably 100 kHz or more. The lower limit of the power supplied between the electrodes is 1 W / cm²50W / cm²The following is preferable, and 2 W / cm²The above is even more preferable.
[0173]
The voltage application area (cm²) Is an area in which discharge occurs.
[0174]
The high-frequency voltage applied between the electrodes may be an intermittent pulse wave or a continuous sine wave, but a sine wave is preferable because the film forming speed increases.
[0175]
Such an electrode is preferably a metal base material coated with a dielectric. At least one of the fixed electrode 26 and the roll electrode 25 is coated with a dielectric, and preferably both are coated with a dielectric. The dielectric is preferably an inorganic substance having a non-dielectric constant of 6 to 45.
[0176]
The shortest distance between the solid dielectric and the electrode when a solid dielectric is placed on one of the electrodes 25 and 26, and the distance between the solid dielectrics when a solid dielectric is placed on both of the electrodes are either case. In light of uniform discharge, 0.5 mm to 20 mm is preferable, and 1 mm ± 0.5 mm is particularly preferable. The distance between the electrodes is determined in consideration of the thickness of the dielectric around the electrodes and the magnitude of the applied voltage.
[0177]
In addition, when the substrate is placed between the electrodes or transported between the electrodes and exposed to plasma, not only is the roll electrode specification that allows the substrate to be transported in contact with one of the electrodes, but also the dielectric surface is polished. By finishing and making the surface roughness Rmax (JIS B 0601) of the electrode 10 μm or less, the thickness of the dielectric and the gap between the electrodes can be kept constant, and the discharge state can be stabilized. Furthermore, the durability can be greatly improved by eliminating the distortion and cracking due to the difference in thermal shrinkage and residual stress of the dielectric and coating the non-porous high-precision inorganic dielectric.
[0178]
In addition, in manufacturing electrodes with a dielectric coating on a metal base material, as described above, it is necessary to polish the dielectric and to minimize the difference in thermal expansion between the metal base material of the electrode and the dielectric. Therefore, it is preferable to line the inorganic material on the surface of the base material by controlling the amount of bubbles mixed as a layer capable of absorbing stress. In particular, the material is preferably a glass obtained by a melting method known as cocoon, and the amount of bubbles mixed in the lowermost layer in contact with the conductive metal base material is 20-30% by volume, and the subsequent layers are 5% by volume. By setting it as the following, the favorable electrode which does not generate | occur | produce dense and a crack will be made.
[0179]
As another method for coating the base material of the electrode with a dielectric, ceramic spraying is performed precisely to a porosity of 10 vol% or less, and further, a sealing treatment is performed with an inorganic material that is cured by a sol-gel reaction. It is done. Here, in order to promote the sol-gel reaction, heat curing or UV curing is good. Further, when the sealing liquid is diluted, and coating and curing are repeated several times in succession, the mineralization is further improved and a dense electrode without deterioration. Can do.
[0180]
FIG. 3A and FIG. 3B are diagrams showing an example of the roll electrode 25, and show the roll electrodes 25c and 25C.
[0181]
As shown in FIG. 3A, the roll electrode 25c, which is an earth electrode, is formed by applying a ceramic-coated dielectric 25b that has been subjected to sealing treatment with an inorganic material after thermal spraying ceramics on a conductive base material 25a such as metal. It is composed of a coated combination. A ceramic coating treated dielectric is coated with 1 mm, and the roll diameter is made to be 200φ after coating, and grounded to the ground. As the ceramic material used for thermal spraying, alumina, silicon nitride or the like is preferably used. Among these, alumina is more preferably used because it is easy to process.
[0182]
Or you may comprise from the combination which coat | covered the lining process dielectric material 25B which provided the inorganic material by lining to 25 A of conductive base materials, such as a metal, like the roll electrode 25C shown in FIG.3 (b). As the lining material, silicate glass, borate glass, phosphate glass, germanate glass, tellurite glass, aluminate glass, and vanadate glass are preferably used. Of these, borate glass is more preferred because it is easy to process.
[0183]
Examples of the conductive base materials 25a and 25A such as metal include metals such as silver, platinum, stainless steel, aluminum, and iron. Stainless steel is preferable from the viewpoint of processing.
[0184]
In this embodiment, the base material of the roll electrode is a stainless steel jacket roll base material having a cooling means with cooling water (not shown).
[0185]
Further, the roll electrodes 25c and 25C (same for the roll electrode 25) are configured to be rotationally driven around the shaft portions 25d and 25D by a drive mechanism (not shown).
[0186]
FIG. 4A shows a schematic perspective view of the fixed electrode 26. Further, the fixed electrode is not limited to a cylindrical shape, but may be a prismatic type like the fixed electrode 36 of FIG. Compared to the cylindrical electrode 26, the prismatic electrode has an effect of extending the discharge range, and is therefore preferably used according to the properties of the film to be formed.
[0187]
Any of the fixed electrodes 26 and 36 has the same structure as the roll electrode 25c and the roll electrode 25C described above. That is, the surroundings of the hollow stainless steel pipes 26a and 36a are covered with the dielectrics 26b and 36b in the same manner as the roll electrodes 25 (25c and 25C), and cooling with cooling water can be performed during discharge. The dielectrics 26b and 36b may be either ceramic-coated dielectrics or lining dielectrics.
[0188]
The fixed electrodes are manufactured so as to have 12φ or 15φ after coating with the dielectric, and the number of the electrodes is set, for example, 14 along the circumference of the roll electrode.
[0189]
FIG. 5 shows a schematic configuration diagram of the plasma discharge processing chamber 30 in which the square fixed electrode 36 of FIG. 4B is disposed around the roll electrode 25. In FIG. 5, the same members as those in FIG.
[0190]
FIG. 6 shows a schematic configuration diagram of a plasma film forming apparatus 50 in which the plasma discharge processing chamber 30 of FIG. 5 is provided. In FIG. 6, in addition to the plasma discharge treatment chamber 30, a gas generator 51, a power source 41, an electrode cooling unit 55, and the like are arranged as an apparatus configuration. The electrode cooling unit 55 includes a tank 57 containing a coolant and a pump 56. As the coolant, an insulating material such as distilled water or oil is used.
[0191]
The gap between the electrodes in the plasma discharge processing chamber 30 of FIG. 6 is set to about 1 mm, for example.
[0192]
The roll electrode 25 and the fixed electrode 36 are disposed at predetermined positions in the plasma discharge treatment chamber 30, the flow rate of the mixed gas generated by the gas generator 51 is controlled, and the mixture gas is supplied from the air supply port 12. It is filled with a mixed gas used for plasma processing, and unnecessary portions are exhausted from an exhaust port.
[0193]
Next, a voltage is applied to the fixed electrode 36 by the power source 41, and the roll electrode 25 is grounded to the ground to generate discharge plasma. Here, the base material is supplied from the roll-shaped original winding base material FF through the rolls 54, 54, 54, and the electrodes in the plasma discharge treatment chamber 30 are brought into one-side contact with the roll electrode 25 through the guide roll 24. It is conveyed in the state. At this time, the surface of the substrate F is subjected to a discharge treatment by the discharge plasma, and then conveyed to the next step via the guide roll 27. Here, the surface of the base film F that is not in contact with the roll electrode 25 is discharged.
[0194]
Moreover, in order to suppress the bad influence by the high temperature at the time of discharge, the temperature of a base material is normal temperature (15 to 25 degreeC)-less than 200 degreeC, More preferably, electrode cooling is performed so that it may be suppressed within normal temperature to 100 degreeC. Cool by unit 55.
[0195]
FIG. 7 is a schematic configuration diagram of another plasma film forming apparatus that can be used in the film forming method of the present invention, such that the film cannot be placed between electrodes, for example, a film on a thick substrate. In the case of forming the thin film, a reactive gas that has been in a plasma state is sprayed onto the substrate to form a thin film.
[0196]
In the plasma film-forming apparatus 60 of FIG. 7, 35a is a dielectric, 35b is a metal base material, and 65 is a power supply. A mixed gas composed of an inert gas and a reactive gas is introduced from above into a slit-like discharge space in which a metal base material 35b is coated with a dielectric 35a, and a high frequency voltage is applied by a power source 65 to plasma the reactive gas. A film is formed on the surface of the substrate 61 by injecting the reactive gas in the plasma state onto the substrate 61.
[0197]
The power source of the plasma film forming apparatus used for forming the film of the present invention, such as the power source 41 of FIG. 6 and the power source 65 of FIG. 7, is not particularly limited, but is an impulse high frequency power source (100 kHz used in continuous mode) manufactured by HEIDEN Laboratory. Pearl industrial high frequency power supply (200 kHz), Pearl industrial high frequency power supply (800 kHz), JEOL high frequency power supply (13.56 MHz), Pearl Industrial high frequency power supply (150 MHz), and the like can be used.
[0198]
Using such a plasma film forming apparatus, a film containing a metal oxide or nitride as a gas barrier layer according to the present invention can be formed by an atmospheric pressure plasma method.
[0199]
The film mainly composed of cellulose ester according to the present invention is a film having the gas barrier layer having a film thickness of 70 nm or more, preferably 1500 nm or less on at least one surface.
[0200]
The transparent laminated film according to the present invention has a very low linear expansion coefficient while maintaining the flexibility characteristic of the resin film as a base material, and moisture, water vapor, etc. in the resin film by forming a moisture-proof gas barrier layer. For example, it is very excellent as a substrate for a liquid crystal display element or an organic electroluminescence (EL) element.
[0201]
In addition, J.H. Sol-Gel Sci. Tech. , P141 to 146 (1998), metal oxides and metal nitrides are used to prevent cracking of metal oxides, metal nitrides, and metal oxynitride thin films used in gas barrier layers. The cracks can be sealed by applying various coating materials on the moisture-proof film of metal oxynitride to further reduce moisture permeability.
[0202]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
[0203]
    Example 1
  <referenceFabrication of Transparent Film 101>
  After 10.0 g of triacetylcellulose (LT55 manufactured by Daicel Chemical Industries, Ltd., hereinafter TAC) was dissolved in a mixed solvent of ethanol 6.0 g and methylene chloride 68.5 g, a film was formed on a glass plate with a doctor blade having a gap width of 1000 μm. The obtained film was dried at 120 ° C. for 30 minutes,referenceThe transparent film 101 was obtained. The film thickness was 100 μm.
[0204]
<Preparation of the transparent film 102 of the present invention>
In a mixed solvent of 6.0 g of ethanol and 68.5 g of methylene chloride, 9.9 g of TAC and 0.01 g of ethylphthalyl ethyl glycolate (Exemplary Compound 1, hereinafter referred to as EPEG) are dissolved, and then a doctor with a gap width of 1000 μm is placed on a glass plate. The film was formed with a blade, and the obtained film was dried at 120 ° C. for 30 minutes to obtain the transparent film 102 of the present invention. The film thickness was 100 μm.
[0205]
<Preparation of the transparent film 103 of the present invention>
TAC 9.95 g and EPEG 0.05 g were dissolved in a mixed solvent of ethanol 6.0 g and methylene chloride 68.5 g, and then a film was formed on a glass plate with a doctor blade having a gap width of 1000 μm. It was made to dry for 30 minutes and it was set as the transparent film 103 of this invention. The film thickness was 100 μm.
[0206]
  <referenceFabrication of Transparent Film 104>
  After mixing 2.53 g of tetramethoxysilane, 1.27 g of methylene chloride and 1.27 g of ethanol, hydrolysis was carried out by adding 0.60 g of 0.5% aqueous nitric acid, and stirring was continued for 1 hour at room temperature.
[0207]
  9.0 g of TAC was dissolved in a mixed solvent of 6.2 g of ethanol and 60.9 g of methylene chloride, and then mixed with the solution obtained by hydrolyzing tetramethoxysilane, and further stirred for 1 hour. The film was formed with a doctor blade having a gap width of 1000 μm, and the resulting film was dried at 120 ° C. for 30 minutes,referenceThe transparent film 104 was obtained. The film thickness was 100 μm.
[0208]
<Preparation of the transparent film 105 of the present invention>
After mixing 2.53 g of tetramethoxysilane, 1.27 g of methylene chloride and 1.27 g of ethanol, hydrolysis was carried out by adding 0.60 g of 0.5% aqueous nitric acid, and stirring was continued for 1 hour at room temperature.
[0209]
After dissolving 8.9 g of TAC and 0.01 g of EPEG in a mixed solvent of 6.2 g of ethanol and 60.9 g of methylene chloride, the solution was mixed with the solution obtained by hydrolyzing tetramethoxysilane and further stirred for 1 hour. The film was formed on a glass plate with a doctor blade having a gap width of 1000 μm, and the obtained film was dried at 120 ° C. for 30 minutes to obtain the transparent film 105 of the present invention. The film thickness was 100 μm.
[0210]
<Preparation of the transparent film 106 of the present invention>
After mixing 2.53 g of tetramethoxysilane, 1.27 g of methylene chloride and 1.27 g of ethanol, hydrolysis was carried out by adding 0.60 g of 0.5% aqueous nitric acid, and stirring was continued for 1 hour at room temperature.
[0211]
After dissolving TAC 8.95 g and EPEG 0.05 g in a mixed solvent of ethanol 6.2 g and methylene chloride 60.9 g, the solution was mixed with the solution obtained by hydrolyzing tetramethoxysilane and further stirred for 1 hour. The film was formed on a glass plate with a doctor blade having a gap width of 1000 μm, and the obtained film was dried at 120 ° C. for 30 minutes to obtain the transparent film 106 of the present invention. The film thickness was 100 μm.
[0212]
  <referenceProduction of Transparent Film 107>
  After dissolving 10.0 g of diacetyl cellulose (L50 manufactured by Daicel Chemical Industries, Ltd., hereinafter DAC) in a mixed solvent of ethanol 6.0 g and methylene chloride 68.5 g, a film was formed on a glass plate with a doctor blade having a gap width of 1000 μm. Drying the resulting film at 120 ° C. for 30 minutes,referenceThe transparent film 107 was obtained. The film thickness was 100 μm.
[0213]
<Preparation of the transparent film 108 of the present invention>
After 9.9 g of TAC and 0.01 g of Exemplified Compound 16 were dissolved in a mixed solvent of ethanol 6.0 g and methylene chloride 68.5 g, a film was formed on a glass plate with a doctor blade having a gap width of 1000 μm. The film was dried at 120 ° C. for 30 minutes to obtain the transparent film 108 of the present invention. The film thickness was 100 μm.
[0214]
<Preparation of the transparent film 109 of the present invention>
After mixing 2.53 g of tetramethoxysilane, 1.27 g of methylene chloride and 1.27 g of ethanol, hydrolysis was carried out by adding 0.60 g of 0.5% aqueous nitric acid, and stirring was continued for 1 hour at room temperature.
[0215]
In a mixed solvent of 6.2 g of ethanol and 60.9 g of methylene chloride, 8.9 g of DAC and 0.01 g of Exemplified Compound 16 were dissolved, and then mixed with the solution obtained by hydrolyzing tetramethoxysilane, After stirring for a period of time, a film was formed on a glass plate with a doctor blade having a gap width of 1000 μm, and the resulting film was dried at 120 ° C. for 30 minutes to obtain the transparent film 109 of the present invention. The film thickness was 100 μm.
[0216]
  <referenceFabrication of Transparent Film 110 of>
  A film obtained by dissolving 5.0 g of TAC and 5.0 g of DAC in a mixed solvent of ethanol 6.0 g and methylene chloride 68.5 g, and forming a film on a glass plate with a doctor blade having a gap width of 1000 μm. Dried at 120 ° C. for 30 minutes,referenceThe transparent film 110 was obtained. The film thickness was 100 μm.
[0217]
<Production of Transparent Film 111 of Comparative Example>
A film obtained by dissolving 9.90 g of TAC and 0.10 g of EPEG in a mixed solvent of ethanol 6.0 g and methylene chloride 68.5 g, and forming a film on a glass plate with a doctor blade having a gap width of 1000 μm. Was dried at 120 ° C. for 30 minutes to obtain a transparent film 111 of a comparative example. The film thickness was 100 μm.
[0218]
<Production of Transparent Film 112 of Comparative Example>
A film obtained by dissolving 9.70 g of TAC and 0.30 g of EPEG in a mixed solvent of ethanol 6.0 g and methylene chloride 68.5 g, and forming a film on a glass plate with a doctor blade having a gap width of 1000 μm. Was dried at 120 ° C. for 30 minutes to obtain a transparent film 112 of a comparative example. The film thickness was 100 μm.
[0219]
<Production of Transparent Film 113 of Comparative Example>
A film obtained by dissolving 9.50 g of TAC and 0.50 g of EPEG in a mixed solvent of 6.0 g of ethanol and 68.5 g of methylene chloride, and forming a film on a glass plate with a doctor blade having a gap width of 1000 μm. Was dried at 120 ° C. for 30 minutes to obtain a transparent film 113 of a comparative example. The film thickness was 100 μm.
[0220]
<Production of Transparent Film 114 of Comparative Example>
It was obtained by dissolving 9.90 g of DAC and 0.10 g of Exemplified Compound 16 in a mixed solvent of 6.0 g of ethanol and 68.5 g of methylene chloride, and forming a film on a glass plate with a doctor blade having a gap width of 1000 μm. The film was dried at 120 ° C. for 30 minutes to obtain a transparent film 114 of a comparative example. The film thickness was 100 μm.
[0221]
<Production of Transparent Film 115 of Comparative Example>
After mixing 2.53 g of tetramethoxysilane, 1.27 g of methylene chloride and 1.27 g of ethanol, hydrolysis was carried out by adding 0.60 g of 0.5% aqueous nitric acid, and stirring was continued for 1 hour at room temperature.
[0222]
In a mixed solvent of 6.2 g of ethanol and 60.9 g of methylene chloride, 8.99 g of DAC and 0.10 g of Exemplified Compound 16 are dissolved, and then mixed with the above solution obtained by hydrolyzing tetramethoxysilane, After stirring for a period of time, a film was formed on a glass plate with a doctor blade having a gap width of 1000 μm, and the obtained film was dried at 120 ° C. for 30 minutes to obtain a transparent film 115 of a comparative example. The film thickness was 100 μm.
[0223]
<Transparent film 116 of comparative example>
“Sumilite FS-1300” manufactured by Sumitomo Bakelite Co., Ltd., which is a polyethersulfone film having a film thickness of 50 μm, was used as the transparent film 116 of the comparative example.
[0224]
<Transparent film 117 of comparative example>
“Arton” manufactured by JSR Corporation, which is a polynorbornene film having a film thickness of 100 μm, was used as the transparent film 117 of the comparative example.
[0225]
The following evaluation was performed about the produced transparent films 101-110 of this invention, and the transparent films 111-117 of a comparative example.
[0226]
<Measurement of transmittance>
Based on JIS K7361-1, TURBIDITY METER T-2600DA made by Tokyo Denshoku was used for measurement.
[0227]
<< Measurement of glass transition temperature and linear expansion coefficient >>
The glass transition temperature of the cellulose esters of the present invention is often unclear and not measured by scanning differential calorimetry (DSC), so the inflection point of the temperature-strain curve in thermal stress strain measurement (TMA) Was the glass transition temperature.
[0228]
TMA-SS6100 manufactured by Seiko Instruments Inc. was used for thermal stress strain measurement. A sample with a film thickness of 100 μm and a width of 4 mm was fixed at a distance between chucks of 20 mm, and after raising the temperature from room temperature to 180 ° C., the residual strain was removed. From room temperature to 5 ° C./min. The linear expansion coefficient was determined from the elongation of the distance between chucks based on JIS K7197.
[0229]
<< Measurement of birefringence and wavelength dispersion characteristics >>
In-plane birefringence (measured with an automatic birefringence meter KOBRA-21ADH manufactured by Oji Scientific Instruments Co., Ltd.) nm).
[0230]
Moreover, the retardation value R at 480 nm₀Retardation value R at (480) and 590 nm₀(590) was similarly measured using KOBRA-21ADH, and the ratio of the birefringence value at 480 nm to the birefringence value at 590 nm was calculated as in the following formula to evaluate the wavelength dispersion of birefringence.
[0231]
P = R₀(480) / R₀(590)
[0232]
[Table 1]

[0233]
As shown in Table 1, the glass transition temperature is decreased and the linear expansion coefficient is increased as the amount of the plasticizer added is increased. However, when the transparent film 103 and the transparent film 111 are compared, the amount added is 1%. Therefore, in order to impart favorable thermal properties to the transparent film, the amount of plasticizer added is preferably less than 1.0%.
[0234]
Further, as seen in the transparent films 104 to 106, the glass transition temperature could be improved by hybridizing silica to TAC, but the linear expansion coefficient was hardly affected.
[0235]
When TAC and DAC were compared, the glass transition temperature was higher in DAC, but the linear expansion coefficient was lower in TAC. Moreover, the transparent film 110 which mixed TAC and DAC obtained the transparent film, without generating a haze, and obtained the transparent film of the intermediate property of both.
[0236]
Further, the heat-resistant transparent films 116 and 117 other than the cellulose-based films were unfavorable transparent films having a larger linear expansion coefficient than the transparent film of the present invention and a birefringence wavelength dispersion characteristic larger than 1.
[0237]
Example 2
On the transparent films 101 to 117 obtained in Example 1, the following hard coat layer coating composition was coated with an extrusion coater so as to have a film thickness of 3 μm, and then dried in a drying section set at 80 ° C. for 1 minute. 120mJ / cm after²It was formed by irradiating with ultraviolet rays. Hard coat layers were formed on both sides of the transparent film.
[0238]
<Clear hard coat layer coating composition>
Dipentaerythritol hexaacrylate monomer 60 parts by mass
Dipentaerythritol hexaacrylate dimer 20 parts by mass
Dipentaerythritol hexaacrylate trimer or higher component 20 parts by mass
4 parts by mass of dimethoxybenzophenone
50 parts by mass of ethyl acetate
50 parts by mass of methyl ethyl ketone
50 parts by mass of isopropyl alcohol
<Creation of moisture barrier film>
As the plasma discharge apparatus, a parallel plate type electrode was used, the transparent film was placed between the electrodes, and a mixed gas was introduced to form a thin film. In addition, the following thing was used for the electrode.
[0239]
A 200 mm x 200 mm x 2 mm stainless steel plate is coated with a high-density, high-adhesion alumina sprayed coating, and then a solution obtained by diluting tetramethoxysilane with ethyl acetate is applied and dried, and then cured by UV irradiation for sealing treatment. It was. The surface of the dielectric thus coated was polished and smoothed so that the Rmax was 5 μm. An electrode was prepared in this way and grounded.
[0240]
On the other hand, as the application electrodes, a plurality of hollow rectangular pure titanium pipes coated with the same dielectric material as described above were produced under the same conditions as the opposing electrode group.
[0241]
The power source used for plasma generation is a high frequency power source JRF-10000 manufactured by JEOL Ltd. and a voltage of 13.56 MHz and 5 W / cm.²The reactive gas having the following composition was allowed to flow between the electrodes.
Inert gas: Argon 99.3% by volume
Reactive gas 1: Hydrogen 0.5% by volume
Reactive gas 2: Tetraethoxysilane 0.3% by volume
On the clear hard coat layer of the transparent films 101 to 117 provided with the clear hard coat layer, atmospheric pressure plasma treatment is performed according to the above reaction gas and reaction conditions, and a silicon oxide film is formed on both sides as a moisture-proof film with a thickness of 100 nm. It prepared so that it might become transparent laminated films 201-217, and the following evaluation was performed.
[0242]
<< Evaluation of moisture permeability >>
The moisture permeability was measured under the condition B (40 ° C., 90% RH) described in JIS-Z-0208. The moisture permeability evaluation was measured before and after the formation of the clear hard coat layer and the moisture-proof layer.
[0243]
In addition, the measurement was performed after 10 series of cooling cycles of heating at 180 ° C. for 1 hour and then allowing to cool at room temperature for 1 hour.
[0244]
[Table 2]

[0245]
Cellulose esters have conventionally had a large problem of high moisture permeability, but as shown in Table 2, high moisture resistance was imparted by a silicon oxide film provided by atmospheric pressure plasma treatment. Further, since the transparent film of the present invention has a small coefficient of linear expansion, the deterioration of moisture permeability was small even after passing through a cooling and heating cycle, and it was a good transparent film.
[0246]
On the other hand, since the transparent laminated films 211 to 216 of the comparative example have a large linear expansion coefficient of the transparent films 111 to 116 as the base material, low moisture permeability can be achieved by forming a moisture-proof layer, but after undergoing a thermal cycle. The moisture-proof layer was cracked by the expansion and contraction of the support and the moisture permeability was deteriorated, which was an undesirable transparent laminated film.
[0247]
In addition, the transparent laminated film 217 is an unfavorable transparent laminated film because the transparent film 117 as a base material has a low glass transition temperature, so that it is softened and deformed during a cooling cycle and cannot measure moisture permeability. there were.
[0248]
【The invention's effect】
According to the present invention, a transparent laminated film having a low coefficient of linear expansion and moisture permeability and suitable as various films for displays, particularly as a film for substrates, was obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing the results of thermal stress strain measurement.
FIG. 2 is a view showing an example of a plasma discharge treatment chamber.
FIG. 3 is a diagram illustrating an example of a roll electrode.
FIG. 4 is a schematic perspective view of a fixed electrode.
5 is a view showing a plasma discharge treatment chamber in which square-shaped fixed electrodes are arranged around a roll electrode 25. FIG.
FIG. 6 is a view showing a plasma film forming apparatus provided with a plasma discharge treatment chamber.
FIG. 7 is a diagram showing another example of a plasma film forming apparatus.
[Explanation of symbols]
10, 30 Plasma discharge treatment chamber
25, 25c, 25C Roll electrode
26, 26c, 26C, 36, 36c, 36C Electrode
25a, 25A, 26a, 36a Conductive base material such as metal
25b, 26b, 36b Ceramic coated dielectric
25B lining treated dielectric
41 Power supply
51 Gas generator
12 Air supply port
13 Exhaust port
55 Electrode cooling unit
FF original winding base material
15, 16 Nip roller
24, 27 Guide rollers
F Base film

Claims (8)

A transparent laminated film having a gas barrier layer on a transparent support, said transparent support is mainly cellulose ester, and the content of the plasticizer is I Oh 0.1 wt% to 0.5 wt% , transparent laminate film plasticizer, characterized by glycolate type plasticizer der Rukoto having an aromatic ring or a cycloalkyl ring in a polyhydric alcohol ester or a molecule having an aromatic ring or a cycloalkyl ring in the molecule.   The transparent support mainly composed of cellulose ester contains 0 to 20% by mass of metal oxide fine particles composed of a polycondensate of a reactive metal compound capable of hydrolytic polycondensation. Transparent laminated film. The transparent laminated film according to claim 2, wherein the metal oxide fine particles are hydrolysis polycondensates of alkoxysilane represented by the following general formula (1).
General formula (1)
R _4-n Si (OR ′) _n
(In the formula, R and R ′ represent a hydrogen atom or a monovalent substituent, and n is 3 or 4.) When the in-plane retardation value at a wavelength of 590 nm is R ₀ (590) and the in-plane retardation value at a wavelength of 480 nm is R ₀ (480), the value of the ratio R ₀ (480) / R ₀ (590) It is 0.8 or more and less than 1.0 , The transparent laminated film of any one of Claims 1-3 characterized by the above-mentioned. Transparent laminate film according to any one of claims 1 to 4, moisture permeability is equal to or less than 10g / m 2 / ^d. The gas barrier layer is a transparent laminate film according to any one of claims 1 to 5, characterized that you have been composed mainly of silicon oxide. The transparent laminated film according to any one of claims 1 to 4 , wherein the transparent support is produced by a solvent casting method . It is a manufacturing method of the transparent laminated film of any one of Claims 1-7, Comprising: It reacts by discharging by applying a high frequency voltage between the electrodes which oppose under the pressure of atmospheric pressure or atmospheric pressure vicinity. sex gas in a plasma state, said by exposing said transparent substrate to a reactive gas in a plasma state, the method for producing a gas barrier layer a transparent formed on a support to transparency laminated film you said Rukoto.

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