JP4265142B2 - Antireflection film, low refractive index region production method, polarizing plate - Google Patents

Description

【０１０７】
上記化合物のうち、荒川化学工業（株）からＫＥ−６０４とＫＥ−６１０はそれぞれ酸価２３７と１７０で市販されている。同じく、荒川化学工業（株）からアビエチン酸、デヒドロアビエチン酸及びパラストリン酸３者の混合物のエステル化物として、ＫＥ−１００及びＫＥ−３５６が、それぞれの酸価は８と０で市販されている。又、アビエチン酸、デヒドロアビエチン酸及びパラストリン酸３者の混合物は、播磨化成（株）からそれぞれの酸価１６７、１６８のＧ−７及びハートールＲ−Ｘで市販されている。
【０１０８】
本発明に用いられるエポキシ樹脂は、以下の構造を有するものが挙げられる。
【０１０９】
【化２】

【０１１０】
アラルダイドＥＰＮ１１７９及びアラルダイドＡＥＲ２６０は旭チバ（株）から市販されている。
【０１１１】
本発明に用いられるケトン樹脂の一例としては、以下の構造のものが挙げられる。
【０１１２】
【化３】

【０１１３】
ハイラック１１０、ハイラック１１０Ｈは日立化成（株）からの市販されているものが用いられる。パラトルエンスルホンアミド樹脂としては、以下の構造のものが挙げられ、トップラーとして、フジアミドケミカル（株）から市販されている。
【０１１４】
【化４】

【０１１５】
これらの可塑剤を単独或いは併用するのが好ましい。
これらの可塑剤の使用量は、フィルム性能、加工性等の点で、セルロースエステルに対して１〜２０質量％であることが好ましい。
【０１１６】
本発明で用いられる支持体に係る紫外線吸収剤について説明する。
本発明の反射防止フィルムの基材（支持体単独の場合もある）としては、液晶等の劣化防止の観点から、紫外線吸収剤が好ましく用いられる。
【０１１７】
紫外線吸収剤としては、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。本発明に好ましく用いられる紫外線吸収剤の具体例としては、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、トリアジン系化合物、シアノアクリレート系化合物、ニッケル錯塩系化合物などが挙げられるが、これらに限定されない。又、特開平６−１４８４３０号記載の高分子紫外線吸収剤も好ましく用いられる。
【０１１８】
ベンゾトリアゾール系紫外線吸収剤としては下記一般式〔１〕で示される化合物が好ましく用いられる。
【０１１９】
【化５】

【０１２０】
式中、Ｒ₁、Ｒ₂、Ｒ₃、Ｒ₄及びＲ₅は同一でも異なってもよく、水素原子、ハロゲン原子、ニトロ基、ヒドロキシル基、アルキル基、アルケニル基、アリール基、アルコキシル基、アシルオキシ基、アリールオキシ基、アルキルチオ基、アリールチオ基、モノ若しくはジアルキルアミノ基、アシルアミノ基又は５〜６員の複素環基を表し、Ｒ₄とＲ₅は閉環して５〜６員の炭素環を形成してもよい。又、上記のこれらの基は、任意の置換基を有していて良い。
【０１２１】
以下に本発明に係る紫外線吸収剤の具体例を挙げるが、本発明はこれらに限定されない。
【０１２２】
ＵＶ−１：２−（２′−ヒドロキシ−５′−メチルフェニル）ベンゾトリアゾール
ＵＶ−２：２−（２′−ヒドロキシ−３′，５′−ジ−ｔｅｒｔ−ブチルフェニル）ベンゾトリアゾール
ＵＶ−３：２−（２′−ヒドロキシ−３′−ｔｅｒｔ−ブチル−５′−メチルフェニル）ベンゾトリアゾール
ＵＶ−４：２−（２′−ヒドロキシ−３′，５′−ジ−ｔｅｒｔ−ブチルフェニル）−５−クロロベンゾトリアゾール
ＵＶ−５：２−（２′−ヒドロキシ−３′−（３″，４″，５″，６″−テトラヒドロフタルイミドメチル）−５′−メチルフェニル）ベンゾトリアゾール
ＵＶ−６：２，２−メチレンビス（４−（１，１，３，３−テトラメチルブチル）−６−（２Ｈ−ベンゾトリアゾール−２−イル）フェノール）
ＵＶ−７：２−（２′−ヒドロキシ−３′−ｔｅｒｔ−ブチル−５′−メチルフェニル）−５−クロロベンゾトリアゾール
ＵＶ−８：２−（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（ＴＩＮＵＶＩＮ１７１、Ｃｉｂａ製）
ＵＶ−９：オクチル−３−〔３−ｔｅｒｔ−ブチル−４−ヒドロキシ−５−（クロロ−２Ｈ−ベンゾトリアゾール−２−イル）フェニル〕プロピオネートと２−エチルヘキシル−３−〔３−ｔｅｒｔ−ブチル−４−ヒドロキシ−５−（５−クロロ−２Ｈ−ベンゾトリアゾール−２−イル）フェニル〕プロピオネートの混合物（ＴＩＮＵＶＩＮ１０９、Ｃｉｂａ製）
上記の中で、融点が２０℃以下の紫外線吸収剤としては、ＵＶ−８が融点が−５６℃であり、ＵＶ−９が常温（２５℃）で黄色透明な粘稠液体である。
【０１２３】
又本発明に係る紫外線吸収剤の一つであるベンゾフェノン系紫外線吸収剤としては下記一般式〔２〕で表される化合物が好ましく用いられる。
【０１２４】
【化６】

【０１２５】
式中、Ｙは水素原子、ハロゲン原子又はアルキル基、アルケニル基、アルコキシル基、及びフェニル基を表し、これらのアルキル基、アルケニル基及びフェニル基は置換基を有していてもよい。Ａは水素原子、アルキル基、アルケニル基、フェニル基、シクロアルキル基、アルキルカルボニル基、アルキルスルホニル基又は−ＣＯ（ＮＨ）_n-1−Ｄ基を表し、Ｄはアルキル基、アルケニル基又は置換基を有していてもよいフェニル基を表す。ｍ及びｎは１又は２を表す。
【０１２６】
上記アルキル基としては、例えば、炭素数２４までの直鎖又は分岐の脂肪族基を表し、アルコキシル基としては例えば、炭素数１８までのアルコキシル基、アルケニル基としては例えば、炭素数１６までのアルケニル基で例えばアリル基、２−ブテニル基などを表す。又、アルキル基、アルケニル基、フェニル基への置換分としてはハロゲン原子、例えば、塩素原子、臭素原子、フッ素原子など、ヒドロキシル基、フェニル基、（このフェニル基にはアルキル基又はハロゲン原子などを置換していてもよい）などが挙げられる。
【０１２７】
以下に一般式〔２〕で表されるベンゾフェノン系化合物の具体例を示すが、本発明はこれらに限定されない。
【０１２８】
ＵＶ−１０：２，４−ジヒドロキシベンゾフェノン
ＵＶ−１１：２，２′−ジヒドロキシ−４−メトキシベンゾフェノン
ＵＶ−１２：２−ヒドロキシ−４−メトキシ−５−スルホベンゾフェノン
ＵＶ−１３：ビス（２−メトキシ−４−ヒドロキシ−５−ベンゾイルフェニルメタン）
本発明で好ましく用いられる上記の紫外線吸収剤は、透明性が高く、偏光板や液晶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く用いられる。
【０１２９】
又、紫外線吸収剤は特願平１１−２９５２０９号に記載されている分配係数が９．２以上の紫外線吸収剤を含むことが、プラズマ処理工程の汚染が少なく、又、各種塗布層の塗布性にも優れる為好ましく、特に分配係数が１０．１以上の紫外線吸収剤を用いることが好ましい。
【０１３０】
可塑剤や紫外線吸収剤を含むセルロースエステルフィルムを基材として用いた場合、これらがブリードアウトするなどによって、プラズマ処理部に付着するなどして工程を汚染し、これがフィルムに付着するなどして故障の原因となることがあった。そのため、この問題を解決するため鋭意検討を重ねた結果、支持体がセルロースエステルと可塑剤を有し、８０℃、９０％ＲＨで時間処理した前後の質量変化が±２質量％未満である支持体であればこのような工程汚染が著しく低減できることが確認された。このようなセルロースエステルフィルムは特願２０００−３３８８８３号記載のセルロースエステルフィルム等が好ましく用いられる。又、この目的のために特開平６−１４８４３０号、特開２００２−４７３５７号記載の高分子紫外線吸収剤（又は紫外線吸収性ポリマー）を好ましく用いることができる。高分子紫外線吸収剤としては、ＰＵＶＡ−３０Ｍ（大塚化学（株）製）などが市販されている。特開平６−１４８４３０号の一般式（１）或いは一般式（２）或いは特開２００２−４７３５７の一般式（３）、（６）及び（７）記載の高分子紫外線吸収剤が特に好ましく用いられる。
【０１３１】
本発明に係る基材の光学特性としては、面内リターデーションＲ₀は０〜１０００ｎｍのものが好ましく用いられ、厚味方向のリターデーションＲ_tは０〜３００ｎｍのものが用途に応じて好ましく用いられる。又、波長分散特性としてはＲ₀（６００）／Ｒ₀（４５０）は０．７〜１．３であることが好ましく、特に１．０〜１．３であること好ましい。
【０１３２】
ここで、Ｒ₀（４５０）は波長４５０ｎｍの光による３次元屈折率測定に基づいた面内リターデーション、Ｒ₀（６００）は波長６００ｎｍの光による３次元屈折率測定に基づいた面内リターデーションを表す。
【０１３３】
基材とプラズマ放電処理により形成される薄膜との密着性を向上させる観点から、本発明の反射防止フィルムは、１種以上のエチレン性不飽和モノマーを含む成分を硬化させて形成した層に上記のプラズマ放電処理をして形成されたものであることが好ましく、特に、前記エチレン性不飽和モノマーを含む成分を硬化させて形成した層をｐＨ１０以上の溶液で処理した後にプラズマ放電処理することにより、更に密着性が改善されるため好ましい。ｐＨ１０以上の溶液としては、０．１〜３ｍｏｌ／Ｌの水酸化ナトリウムもしくは水酸化カリウム水溶液等が好ましく用いられ、４０〜６０℃で３０〜１２０秒処理された後、水洗・乾燥されることが好ましい。
【０１３４】
エチレン性不飽和モノマーを含む成分を重合させて形成した樹脂層としては、活性線硬化樹脂或いは熱硬化樹脂を構成成分として含有する層が好ましく用いられるが、特に好ましく用いられるのは活性線硬化樹脂層である。
【０１３５】
ここで、活性線硬化樹脂層とは紫外線や電子線のような活性線照射により架橋反応などを経て硬化する樹脂を主たる成分とする層をいう。活性線硬化樹脂としては紫外線硬化性樹脂や電子線硬化性樹脂などが代表的なものとして挙げられるが、紫外線や電子線以外の活性線照射によって硬化する樹脂でもよい。紫外線硬化性樹脂としては、例えば、紫外線硬化型アクリルウレタン系樹脂、紫外線硬化型ポリエステルアクリレート系樹脂、紫外線硬化型エポキシアクリレート系樹脂、紫外線硬化型ポリオールアクリレート系樹脂、又は紫外線硬化型エポキシ樹脂等を挙げることが出来る。
【０１３６】
紫外線硬化型アクリルウレタン系樹脂は、一般にポリエステルポリオールにイソシアネートモノマー、もしくはプレポリマーを反応させて得られた生成物に更に２−ヒドロキシエチルアクリレート、２−ヒドロキシエチルメタクリレート（以下アクリレートにはメタクリレートを包含するものとしてアクリレートのみを表示する）、２−ヒドロキシプロピルアクリレート等の水酸基を有するアクリレート系のモノマーを反応させることによって容易に得ることが出来る（例えば、特開昭５９−１５１１１０号等を参照）。
【０１３７】
紫外線硬化型ポリエステルアクリレート系樹脂は、一般にポリエステルポリオールに２−ヒドロキシエチルアクリレート、２−ヒドロキシアクリレート系のモノマーを反応させることによって容易に得ることが出来る（例えば、特開昭５９−１５１１１２号を参照）。
【０１３８】
紫外線硬化型エポキシアクリレート系樹脂の具体例としては、エポキシアクリレートをオリゴマーとし、これに反応性希釈剤、光反応開始剤を添加し、反応させたものを挙げることが出来る（例えば、特開平１−１０５７３８号）。この光反応開始剤としては、ベンゾイン誘導体、オキシムケトン誘導体、ベンゾフェノン誘導体、チオキサントン誘導体等のうちから、１種もしくは２種以上を選択して使用することが出来る。
【０１３９】
又、紫外線硬化型ポリオールアクリレート系樹脂の具体例としては、トリメチロールプロパントリアクリレート、ジトリメチロールプロパンテトラアクリレート、ペンタエリスリトールトリアクリレート、ペンタエリスリトールテトラアクリレート、ジペンタエリスリトールヘキサアクリレート、アルキル変性ジペンタエリスリトールペンタアクリレート等を挙げることが出来る。
【０１４０】
これらの樹脂は通常公知の光増感剤と共に使用される。又上記光反応開始剤も光増感剤としても使用出来る。具体的には、アセトフェノン、ベンゾフェノン、ヒドロキシベンゾフェノン、ミヒラーズケトン、α−アミロキシムエステル、チオキサントン等及びこれらの誘導体を挙げることが出来る。又、エポキシアクリレート系の光反応剤の使用の際、ｎ−ブチルアミン、トリエチルアミン、トリ−ｎ−ブチルホスフィン等の増感剤を用いることが出来る。塗布乾燥後に揮発する溶媒成分を除いた紫外線硬化性樹脂組成物に含まれる光反応開始剤又光増感剤は該組成物の２．５〜６質量％であることが好ましい。
【０１４１】
樹脂モノマーとしては、例えば、不飽和二重結合が一つのモノマーとして、メチルアクリレート、エチルアクリレート、ブチルアクリレート、酢酸ビニル、ベンジルアクリレート、シクロヘキシルアクリレート、スチレン等の一般的なモノマーを挙げることが出来る。又不飽和二重結合を二つ以上持つモノマーとして、エチレングリコールジアクリレート、プロピレングリコールジアクリレート、ジビニルベンゼン、１，４−シクロヘキサンジアクリレート、１，４−シクロヘキシルジメチルアジアクリレート、前出のトリメチロールプロパントリアクリレート、ペンタエリスリトールテトラアクリルエステル等を挙げることができる。
【０１４２】
例えば、紫外線硬化性樹脂としては、アデカオプトマーＫＲ・ＢＹシリーズ：ＫＲ−４００、ＫＲ−４１０、ＫＲ−５５０、ＫＲ−５６６、ＫＲ−５６７、ＢＹ−３２０Ｂ（以上、旭電化工業株式会社製）、或いはコーエイハードＡ−１０１−ＫＫ、Ａ−１０１−ＷＳ、Ｃ−３０２、Ｃ−４０１−Ｎ、Ｃ−５０１、Ｍ−１０１、Ｍ−１０２、Ｔ−１０２、Ｄ−１０２、ＮＳ−１０１、ＦＴ−１０２Ｑ８、ＭＡＧ−１−Ｐ２０、ＡＧ−１０６、Ｍ−１０１−Ｃ（以上、広栄化学工業株式会社製）、或いはセイカビームＰＨＣ２２１０（Ｓ）、ＰＨＣ Ｘ−９（Ｋ−３）、ＰＨＣ２２１３、ＤＰ−１０、ＤＰ−２０、ＤＰ−３０、Ｐ１０００、Ｐ１１００、Ｐ１２００、Ｐ１３００、Ｐ１４００、Ｐ１５００、Ｐ１６００、ＳＣＲ９００（以上、大日精化工業株式会社製）、或いはＫＲＭ７０３３、ＫＲＭ７０３９、ＫＲＭ７１３０、ＫＲＭ７１３１、ＵＶＥＣＲＹＬ２９２０１、ＵＶＥＣＲＹＬ２９２０２（以上、ダイセル・ユーシービー株式会社）、或いはＲＣ−５０１５、ＲＣ−５０１６、ＲＣ−５０２０、ＲＣ−５０３１、ＲＣ−５１００、ＲＣ−５１０２、ＲＣ−５１２０、ＲＣ−５１２２、ＲＣ−５１５２、ＲＣ−５１７１、ＲＣ−５１８０、ＲＣ−５１８１（以上、大日本インキ化学工業株式会社製）、或いはオーレックスＮｏ．３４０クリヤ（中国塗料株式会社製）、或いはサンラッドＨ−６０１（三洋化成工業株式会社製）、或いはＳＰ−１５０９、ＳＰ−１５０７（昭和高分子株式会社製）、或いはＲＣＣ−１５Ｃ（グレース・ジャパン株式会社製）、アロニックスＭ−６１００、Ｍ−８０３０、Ｍ−８０６０（以上、東亞合成株式会社製）或いはこの他の市販のものから適宜選択して利用できる。
【０１４３】
本発明に用いられる活性線硬化樹脂層は公知の方法で塗設することができる。活性線硬化性樹脂を光硬化反応により硬化させて皮膜層を形成するための光源としては、紫外線を発生する光源であれば何れでも使用出来る。例えば、低圧水銀灯、中圧水銀灯、高圧水銀灯、超高圧水銀灯、カーボンアーク灯、メタルハライドランプ、キセノンランプ等を用いることが出来る。照射条件はそれぞれのランプによって異なるが、照射光量は２０〜１００００ｍＪ／ｃｍ²程度あればよく、好ましくは５０〜２０００ｍＪ／ｃｍ²である。近紫外線領域〜可視光線領域にかけてはその領域に吸収極大のある増感剤を用いることによって使用出来る。
【０１４４】
活性線硬化樹脂層を塗設する際の溶媒として前述のバックコート層や導電性微粒子を含有する樹脂層を塗設する溶媒、例えば、炭化水素類、アルコール類、ケトン類、エステル類、グリコールエーテル類、その他の溶媒の中から適宜選択し、或いはこれらを混合し利用できる。好ましくは、プロピレングリコールモノ（炭素数１〜４のアルキル基）アルキルエーテル又はプロピレングリコールモノ（炭素数１〜４のアルキル基）アルキルエーテルエステルを５質量％以上、更に好ましくは５〜８０質量％以上含有する溶媒が用いられる。
【０１４５】
紫外線硬化性樹脂組成物塗布液の塗布方法としては、グラビアコーター、スピナーコーター、ワイヤーバーコーター、ロールコーター、リバースコーター、押し出しコーター、エアードクターコーター等公知の方法を用いることが出来る。塗布量はウェット膜厚で０．１〜３０μｍが適当で、好ましくは、０．５〜１５μｍである。塗布速度は好ましくは１０〜６０ｍ／分で行われる。
【０１４６】
紫外線硬化性樹脂組成物は塗布乾燥された後、紫外線を光源より照射するが、照射時間は０．５秒〜５分がよく、紫外線硬化性樹脂の硬化効率、作業効率とから３秒〜２分がより好ましい。
【０１４７】
こうして得た硬化皮膜層に、ブロッキングを防止するため、又対擦り傷性等を高めるために無機或いは有機の微粒子を加えることが好ましい。例えば、無機微粒子としては酸化ケイ素、酸化チタン、酸化アルミニウム、酸化錫、酸化亜鉛、炭酸カルシウム、硫酸バリウム、タルク、カオリン、硫酸カルシウム等を挙げることができ、又有機微粒子としては、ポリメタアクリル酸メチルアクリレート樹脂粉末、アクリルスチレン系樹脂粉末、ポリメチルメタクリレート樹脂粉末、シリコン系樹脂粉末、ポリスチレン系樹脂粉末、ポリカーボネート樹脂粉末、ベンゾグアナミン系樹脂粉末、メラミン系樹脂粉末、ポリオレフィン系樹脂粉末、ポリエステル系樹脂粉末、ポリアミド系樹脂粉末、ポリイミド系樹脂粉末、或いはポリ弗化エチレン系樹脂粉末等を挙げることができ、紫外線硬化性樹脂組成物に加えることが出来る。これらの微粒子粉末の平均粒径としては、０．００５μｍ〜１μｍが好ましく０．０１〜０．１μｍであることが特に好ましい。
【０１４８】
紫外線硬化性樹脂組成物と微粒子粉末との割合は、樹脂組成物１００質量部に対して、０．１〜１０質量部となるように配合することが望ましい。又紫外線硬化性樹脂を硬化させた層（紫外線硬化性樹脂層）は２層以上を積層して形成しても良い。
【０１４９】
このようにして形成された紫外線硬化性樹脂層は中心線表面粗さＲａが１〜５０ｎｍのクリアハードコート層であっても、Ｒａが０．１〜１μｍ程度の防眩層であってもよい。又、これらの紫外線硬化性樹脂層は鉛筆硬度の２Ｈ以上、好ましくは４Ｈ〜６Ｈであることが好ましい。又、これらの紫外線硬化性樹脂層の残留溶媒は０〜３％未満、好ましくは０〜１％未満に乾燥されていることが好ましく、特に好ましくは０〜０．１％未満となっていることが望ましい。
【０１５０】
本発明では、これらの層の上にプラズマ放電処理することができる。特に本発明の方法によれば、表面の凹凸のある基材上に均一な低屈折率層或いは高屈折率層等の光学干渉層を設けることが出来る。特に、ＪＩＳ Ｂ ０６０１で規定される中心線平均粗さ（Ｒａ）が０．１〜０．５μｍの防眩層上に均一にプラズマ放電処理できるために好ましい。
【０１５１】
本発明においては、上記のような基材面に対して薄膜を設ける場合、平均膜厚に対する膜厚偏差を±１０％になるように設けることが好ましく、更に好ましくは±５％以内であり、特に好ましくは±１％以内になるように設けることが好ましい。
【０１５２】
本発明の反射防止フィルムを作製する場合、プラズマ放電処理する前にプラズマ放電処理面に紫外線を照射することが形成される皮膜の密着性に優れるため好ましい。紫外線照射光量としては５０〜２０００ｍＪ／ｃｍ²であることが好ましい。５０ｍＪ／ｃｍ²未満では、効果が十分ではなく、２０００ｍＪ／ｃｍ²を越えると基材の変形等が生じる恐れがあり好ましくない。紫外線照射後、１時間以内にプラズマ放電処理することが好ましく、特に紫外線照射後１０分以内にプラズマ放電処理することが好ましい。プラズマ放電処理前の紫外線の照射は、前述の紫外線硬化性樹脂の硬化のための紫外線照射と同時に行ってもよく、その場合、硬化のために最低限必要な紫外線照射量よりも多くすることが好ましい。
【０１５３】
本発明の反射防止フィルムを作製する場合、プラズマ放電処理を行った後に紫外線照射することも、形成された皮膜を早期に安定化させるために有効である。このため、紫外線照射光量として５０〜２０００ｍＪ／ｃｍ²をプラズマ放電処理後にプラズマ放電処理面に照射することが好ましい。これらの処理はプラズマ放電処理の後、巻き取り工程までの間に行うことが好ましい。又、プラズマ放電処理後の基材は５０〜１３０℃に調整された熱処理ゾーンにおいて１〜３０分処理されることが好ましい。
【０１５４】
反射防止フィルムは両面にプラズマ放電処理が施されていることが処理後の反射防止フィルムのカールが少なくなるため好ましい。裏面のプラズマ放電処理は別々に行ってもよいが、両面同時にプラズマ放電処理を行うことが好ましく、反射防止層を有する面の裏面側には、プラズマ放電処理による裏面加工を行うことが好ましい。例えば、特願２０００−２７３０６６号記載の易接着加工、特開２００１−３３７２０１号記載の帯電防止加工が挙げられるが、特にこれらに限定されない。
【０１５５】
本発明においては、屈折率１．６〜２．３の高屈折率層、屈折率１．３〜１．５の低屈折率層を長尺の基材表面に連続して設けることが好ましい。これにより各層の間の密着性が良好となる。好ましくは基材フィルム上に紫外線硬化性樹脂層を設けた後、直ちにプラズマ放電処理によって高屈折率層及び低屈折率層を設けることがより好ましい。
【０１５６】
本発明の反射防止フィルムでは、高屈折率層及び低屈折率層は、各々２層以上を交互に積層して更に反射率が少ない反射防止フィルムを得ることが出来る。又、各層の炭素含有率が０．１〜２０％であると下層との密着性と膜の柔軟性に優れるために好ましい。即ち、プラズマ放電処理によって形成された層は有機物（炭素原子）を含んでいるため、その範囲が膜に柔軟性を与えるため、膜の密着性に優れ好ましい。炭素の比率があまり多くなりすぎると経時で屈折率が変動しやすくなる傾向があり、好ましくない。
【０１５７】
屈折率１．３〜１．５の低屈折率層を有する反射防止フィルムでは、低屈折率層の基材フィルム側に炭素含有率が５％未満の領域を有し、かつ低屈折率領域の上方表面側に炭素含有率が５〜６０％の領域を有することが好ましい。屈折率１．６〜２．３の高屈折率層を有する反射防止フィルムにおいて、高屈折率層の炭素含有率が０．１〜２０％であることが好ましい。
【０１５８】
本発明の反射防止フィルムは、液晶ディスプレイ、有機ＥＬディスプレイ、プラズマディスプレイ等の各種表示装置に好ましく用いられる。
【０１５９】
【実施例】
以下、本発明を実施例により説明するが、本発明はこれらに限定されない。尚、以下の「部」は「質量部」を表す。
【０１６０】
実施例１
《基材フィルムの作製》
以下に示す方法に従って、基材であるセルロースエステルフィルムを作製した。
（ドープの調製）
以下に記載の素材を密閉容器に投入し、加熱、撹拌しながら、完全に溶解、濾過し、ドープ１〜３を調製した。尚、二酸化珪素微粒子（アエロジル Ｒ９７２Ｖ）はエタノールに分散した後、添加した。２次粒子の平均粒径は０．２μｍであった。
ドープ１
セルローストリアセテート（アセチル置換度２．８８） １００部
トリメチロールプロパントリベンゾエート ６部
エチルフタリルエチルグリコレート ６部
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 ０．５部
５−クロロ−２−（３，５−ジ ｓｅｃ−ブチル−２−ヒドロキシフェニル）
−２Ｈ−ベンゾトリアゾール ０．５部
メチレンクロライド ４１８部
エタノール ２３部
アエロジル Ｒ９７２Ｖ（日本アエロジル（株）製） ０．１３部
ドープ２
セルロースアセテートプロピオネート １００部
（アセチル置換度１．９ プロピオニル置換度０．８）
トリメチロールプロパントリベンゾエート ６部
エチルフタリルエチルグリコレート ６部
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 ０．５部
５−クロロ−２−（３，５−ジ ｓｅｃ−ブチル−２−ヒドロキシフェニル）
−２Ｈ−ベンゾトリアゾール ０．５部
酢酸メチル ４００部
エタノール ５０部
アエロジル Ｒ９７２Ｖ（日本アエロジル（株）製） ０．１３部
ドープ３
セルローストリアセテート（アセチル置換度２．８８） １００部
トリフェニルホスフェート １２部
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 ０．５部
５−クロロ−２−（３，５−ジ ｓｅｃ−ブチル−２−ヒドロキシフェニル）
−２Ｈ−ベンゾトリアゾール ０．５部
メチレンクロライド ４１８部
エタノール ２３部
アエロジル Ｒ９７２Ｖ（日本アエロジル（株）製） ０．１３部
（セルロースエステルフィルムの作製）
得られたドープ１を用いて、以下のようにしてそれぞれ膜厚４０μｍのセルロースエステルフィルム１、膜厚６０μｍのセルロースエステルフィルム２を作製した。同様にドープ２を用いて、以下のようにしてそれぞれ膜厚４０μｍのセルロースエステルフィルム３、膜厚８０μｍのセルロースエステルフィルム４を作製した。同様にドープ３を用いて、以下のようにしてそれぞれ膜厚４０μｍのセルロースエステルフィルム５、膜厚６０μｍのセルロースエステルフィルム６を作製した。
【０１６１】
ドープを濾過した後、ベルト流延装置を用い、ドープ温度３６℃で３６℃のステンレスバンド支持体上に均一に流延した。温風を当てながら支持体上で乾燥させた後、ステンレスバンド支持体上からウェブを剥離した。
【０１６２】
ステンレスバンド支持体から剥離した後、７０℃の雰囲気でロール搬送し縦方向に搬送張力をかけながら乾燥させた後、テンターで残留溶媒量１０％のとき８０℃の雰囲気内で幅方向（幅手方向）に１．０６倍延伸し、幅把持を解放して、ロール搬送しながら１２５℃の乾燥ゾーンで乾燥を終了させ、フィルム両端に幅１０ｍｍ、高さ８μｍのナーリング加工を施し、セルロースエステルフィルム１〜６を作製した。フィルム幅は１３００ｍｍ、巻き取り長は２０００ｍとした。
【０１６３】
次に、下記の方法で表１記載のように各々の塗布層を設けた基材フィルム１〜２４を作製した。ここで、流延製膜時、流延膜がステンレスバンド支持体に接していた側のフィルム面をＢ面として、その反対側の面をＡ面とする。
《帯電防止層（ＡＮＳ層）の塗設》
上記基材フィルム１３〜１６について、それぞれＢ面に下記の塗布組成物（１）をウェット膜厚１３μｍとなるように押し出しコートを行い、乾燥温度９０℃にて乾燥させ帯電防止層を塗設した。
・塗布組成物（１）（帯電防止層用塗布組成物）
アクリペットＭＤ（三菱レーヨン（株）製） ０．５部
プロピレングリコールモノメチルエーテル ６０部
メチルエチルケトン １６部
乳酸エチル ５部
メタノール ８部
導電性ポリマー樹脂Ｐ−１（平均粒径０．１μｍ粒子） ０．５部
【０１６４】
【化７】

【０１６５】
《バックコート層（ＢＣ層）の塗設》
下記の塗布組成物（２）をセルロースエステルフィルムのＡ面に、ウェット膜厚１５μｍとなるように押し出しコートし、乾燥温度８０℃にて乾燥させバックコート層を塗設した。
・塗布組成物（２）（バックコート層塗布組成物）
アセトン ３０部
酢酸エチル ４５部
イソプロピルアルコール １０部
ジアセチルセルロース ０．５部
超微粒子シリカ２％アセトン分散液（アエロジル ２００Ｖ：日本アエロジル
（株）製） ０．１部
《クリアハードコート層の塗設》
−ＣＨＣ１層−
下記の塗布組成物（３）をグラビアコートし、次いで８０℃に設定された乾燥部で乾燥した後、１２０ｍＪ／ｃｍ²で紫外線照射し、乾燥膜厚で３μｍの中心線平均粗さ（Ｒａ）０．０１μｍのクリアハードコート層（ＣＨＣ１層）を設けた。ここで、上記の中心線平均粗さ（Ｒａ）はＪＩＳ Ｂ ０６０１で規定される値である。
・塗布組成物（３）（クリアハードコート層塗布組成物）
紫外線硬化型アクリルウレタン系樹脂 １００部
（ユニディック１７−８０６（大日本インキ（株）製）９９部、コロネートＬ（ポリイソシアネート化合物：日本ポリウレタン（株）製）１部）
光重合開始剤（イルガキュア１８４ チバガイギー社製） ３部
を溶剤（酢酸エチル）にてホモジナイザーにより混合して揮発分濃度６０％の均質な塗布液を調製した。
−ＣＨＣ２層−
下記の塗布組成物（４）をグラビアコートし、次いで８０℃に設定された乾燥部で乾燥した後、１１８ｍＪ／ｃｍ²で紫外線照射し、乾燥膜厚で３μｍの中心線平均粗さ（Ｒａ）０．０１μｍのクリアハードコート層（ＣＨＣ２層）を設けた。ここで、上記の中心線平均粗さ（Ｒａ）はＪＩＳ Ｂ ０６０１で規定される値である。
・塗布組成物（４）（クリアハードコート層塗布組成物）
ジペンタエリスリトールヘキサアクリレート単量体 ６０部
ジペンタエリスリトールヘキサアクリレート２量体 ２０部
ジペ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部
ジメトキシベンゾフェノン光反応開始剤 ４部
酢酸エチル ５０部
メチルエチルケトン ５０部
イソプロピルアルコール ５０部
《防眩層の塗設》
−ＡＧ１層−
下記の塗布組成物（５）をグラビアコートし、次いで８０℃に設定された乾燥部で乾燥した後、１１８ｍＪ／ｃｍ²で紫外線照射し、乾燥膜厚で３μｍの防眩層（ＡＧ１層）を設けた。中心線平均粗さ（Ｒａ）は０．２μｍであった。ここで、上記の中心線平均粗さ（Ｒａ）はＪＩＳ Ｂ ０６０１で規定される値である。
・塗布組成物（５）（ＡＧ１層塗布組成物）
合成シリカ微粒子（平均粒径０．５μｍ） １０部
合成シリカ微粒子（平均粒径１．４μｍ） １０部
紫外線硬化型アクリルウレタン系樹脂 １００部
（ユニディック１７−８０６（大日本インキ（株）製）９９部、コロネートＬ（ポリイソシアネート化合物：日本ポリウレタン（株）製）１部）
光重合開始剤（イルガキュア１８４ チバガイギー社製） ３部
を溶剤（酢酸エチル）にてホモジナイザーにより混合して揮発分濃度６０％の均質な分散液を調製した。
−ＡＧ２層−
下記の塗布組成物（６）をグラビアコートし、次いで８０℃に設定された乾燥部で乾燥した後、１１８ｍＪ／ｃｍ²で紫外線照射し、乾燥膜厚で３μｍの防眩層（ＡＧ２層）を設けた。中心線平均粗さ（Ｒａ）は０．２μｍであった。ここで、上記の中心線平均粗さ（Ｒａ）はＪＩＳ Ｂ ０６０１で規定される値である。
・塗布組成物（６）（ＡＧ２層塗布組成物）
酢酸エチル ５０部
メチルエチルケトン ５０部
イソプロピルアルコール ５０部
アエロジル Ｒ９７２Ｖ（１次粒子平均粒径１６ｎｍ）
（日本アエロジル（株）製） ５部
以上を高速攪拌機（ＴＫホモミキサー、特殊機化工業（株）製）で攪拌し、その後衝突型分散機（マントンゴーリン、ゴーリン（株）製）で分散した後、下記の成分を添加し、塗布組成物（６）を調製した。
【０１６６】
ジペンタエリスリトールヘキサアクリレート単量体 ６０部
ジペンタエリスリトールヘキサアクリレート２量体 ２０部
ジペ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部
ジメトキシベンゾフェノン光反応開始剤 ４部
【０１６７】
【表１】

【０１６８】
〈大気圧プラズマ放電処理による反射防止層の形成〉
作製した基材フィルムのクリアハードコート層もしくは防眩層の上に図２の大気圧プラズマ放電処理によって、中屈折率層、高屈折率層を順に設けた。ロール電極には、シリコンオイルによる温度調整機能を有するステンレス製ジャケットロール母材（温度調整機能は図２には図示していない）を用いた。これにセラミック溶射によりアルミナを１ｍｍ被覆し、その上に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て封孔処理を行いＲｍａｘ３μｍの誘電体を有するロール電極を製作しアース（接地）した。一方、対向電極としてはチタン製とし内部に温度調整のための媒体の循環流路を設け、上記同様の誘電体を同条件にて被覆し、相対する電極群とし、第１のプラズマ放電処理装置を中屈折率層用に、第２のそれを高屈折率層用に、更に第３のそれを低屈折率層用として、それぞれ必要な膜厚が各々得られるように調整した。又、第１、２及び３のプラズマ放電処理装置の電源は高周波電源（パール工業製）を使用し、連続周波数を２ＭＨｚとし、３Ｗ／ｃｍ²の電力を供給した。ロール電極は、ドライブを用いて基材フィルムの搬送に同期して回転させた。尚、電極間隙は１．２ｍｍ、反応ガスの圧力を大気圧＋１ｋＰａとして行った。プラズマ放電処理に用いた反応ガスの組成を以下に記す。液体の反応ガス成分は気化器を用いて気化させて不活性ガスと混合してプラズマ放電処理装置に導入した。各々の反応ガスは８０℃で放電部に供給された。
（酸化錫層（中屈折率層）形成用反応ガス）
不活性ガス（ヘリウム） ９９．４体積％
反応ガス（酸素ガス） ０．３体積％
反応ガス（テトラブチル錫蒸気） ０．３体積％
（酸化チタン層（高屈折率層）形成用反応ガス）
不活性ガス（ヘリウム） ９９．４体積％
反応ガス（酸素ガス） ０．３体積％
反応ガス（テトライソプロポキシチタン蒸気） ０．３体積％
連続的に大気圧プラズマ処理して、順に酸化錫層（屈折率１．７、膜厚７６ｎｍ）、酸化チタン層（屈折率２．１４、膜厚１１２ｎｍ）を形成した。
【０１６９】
その上に更に下記の反応ガスを使用して低屈折率層である酸化珪素層（屈折率１．４６、膜厚８７ｎｍ）を設け、以下の表２、表３記載の光学フィルム１〜４０を作製した。低屈折率層は途中でガス条件を１〜３の中から変更して形成し、最初ガス条件Ａで処理して形成した後、次いでガス条件Ｂで処理することによって形成し、全体で膜厚８７ｎｍとなるようにした。各々のガス条件で形成された低屈折率層はＸＰＳ装置を用いて各元素の含有量を求め、下式に従って炭素含有率を得た。
・ガス条件１
テトラエトキシシラン ０．３％
ヘリウム ９９．５％
酸素 ０．２％
炭素含有率（酸化珪素層中） ０．２％
・ガス条件２
テトラエトキシシラン ０．１５％
メチルトリエトキシシラン ０．１５％
ヘリウム ９９．５％
酸素 ０．２％
炭素含有率（酸化珪素層中） １０％
・ガス条件３
テトラエトキシシラン ０．２％
メチルトリエトキシシラン ０．１％
ヘリウム ９９．６％
四フッ化メタン ０．１％
炭素含有率（酸化珪素層中） ７％
《各元素含有量の測定》
低屈折率領域における炭素、珪素、酸素及びフッ素含有量は、ＸＰＳ装置を用いてその値を測定する。ＸＰＳ装置としては特に限定なく、いかなる機種も使用することができるが、本発明においてはＶＧサイエンティフィックス社製ＥＳＣＡＬＡＢ ２００Ｒを用いた。Ｘ線アノードにはＭｇを用い、出力６００Ｗ（加速電圧１５ｋＶ、エミッション電流４０ｍＡ）で測定した。エネルギー分解能は、清浄なＡｇ３ｄ５／２ピークの半値幅で規定したとき、１．５〜１．７ｅＶとなるように設定した。低屈折率領域の測定を行う前に、汚染による影響を除くために、薄膜の膜厚の５〜１０％の厚さに相当する表面層をエッチング除去する必要がある。表面層の除去には、希ガスイオンが利用できるイオン銃を用い、イオン種としては、Ｈｅ、Ｎｅ、Ａｒ、Ｘｅ、Ｋｒなどが利用できる。
【０１７０】
又、膜の深さ方向における炭素、珪素、酸素含有量の変化も希ガスイオンによるエッチングを用いて求めた。本測定おいては、加速電圧３ｋＶのＡｒイオンを用いて１分間隔でエッチングを行い、膜表面の元素含有量を測定した。尚、含有量測定においては結合エネルギー０ｅＶから１１００ｅＶの範囲を、データ取り込み間隔１．０ｅＶで測定し、いかなる元素が検出されるかを求めた。次に、検出された、エッチングイオン種を除く全ての元素について、データの取り込み間隔を０．２ｅＶとして、その最大強度を与える光電子ピークについてナロースキャンを行い、各元素のスペクトルを測定した。
【０１７１】
得られたスペクトルは、測定装置、又はコンピューターの違いによる含有率算出結果の違いを生じせしめなくするために、ＶＡＭＡＳ ＳＣＡ ＪＡＰＡＮ製のＣＯＭＭＯＮ ＤＡＴＡ ＰＲＯＣＥＳＳＩＮＧ ＳＹＳＴＥＭ（Ｖｅｒ．２．３）上に転送した後、同ソフトで処理を行い、検出された元素の含有率を原子数濃度（ａｔｏｍｉｃ ｃｏｎｃｅｎｔｒａｔｉｏｎ）として求めた。定量処理を行う前に、各元素についてＣｏｕｎｔ Ｓｃａｌｅのキャリブレーションを行い、５ポイントのスムージング処理を行った。定量処理では、バックグラウンドを除去したピークエリア強度（ｃｐｓ×ｅＶ）を用いた。バックグラウンド処理には、Ｓｈｉｒｌｅｙによる方法を用いた。Ｓｈｉｒｌｅｙ法については、Ｄ．Ａ．Ｓｈｉｒｌｅｙ，Ｐｈｙｓ．Ｒｅｖ．，Ｂ５，４７０９（１９７２）を参考にした。
【０１７２】
尚、本発明では低屈折率層における、各元素の平均含有率は上記深さ方向分析を行った結果得られた各分析点での元素含有量の平均とした。ここで、炭素含有率は下式により求めた。
【０１７３】
炭素含有率％＝炭素含有量／（炭素含有量＋珪素含有量＋酸素含有量）×１００
《評価》
得られた光学フィルム１〜４０について以下のような評価を行った。
（巻き形状）
光学フィルムを埃付着防止のためポリエチレンシートで包んだ後、４２℃、８０％ＲＨの倉庫で１ヶ月間保管し、１ヶ月経過後の巻きの状態を目視で観察し、下記のようにランク評価した。
【０１７４】
Ａ・・・ロールの表面に皺、変形等の変化は認められない
Ｂ・・・ロールの表面に僅かに皺が認められるが、変形は認められない
Ｃ・・・ロールの表面に弱い皺が認められ、一部に変形も認められる
Ｄ・・・ロールの表面〜内部に強い皺、表面に強い変形が有り、内部まで変形有り
上記のランクについての実用性判断は下記の通りである。
【０１７５】
Ａ・・・切除することなく使用できる
Ｂ・・・数ｍ切除して使用できる
Ｃ・・・表面から数巻き分（数ｍ〜十数ｍ）を切除することによって使用できる
Ｄ・・・巻きの変形が認められなくなるまで、内部（数１０ｍ以上）まで切除しなければ使用できない
（カール）
作製したロールフィルムを４２℃、８０％ＲＨの雰囲気で１ヶ月間保管したフィルムを１０ｃｍ×１０ｃｍの大きさに切り出して、２３℃、５５％ＲＨの環境下で反射防止層形成面を上にして平坦なガラス上に置き、端部の浮き上がりの高さを測定した。
【０１７６】
Ａ・・・端部の浮き上がり高さが５ｍｍ未満
Ｂ・・・端部の浮き上がり高さが５〜１０ｍｍ未満
Ｃ・・・端部の浮き上がり高さが１０〜１５ｍｍ未満
Ｄ・・・端部の浮き上がり高さが１５ｍｍ以上
（偏光板の作製）
作製したロールフィルムを４２℃、８０％ＲＨの雰囲気で１ヶ月間保管し、そのフィルムを表面側の偏光板保護フィルムとして、裏面側の偏光板保護フィルムには、表面側に用いた偏光板保護フィルムに用いられているセルロースエステルフィルム（各塗布層及び反射防止層を設ける前の）を各々使用して偏光板とした。
１．偏光膜の作製
厚さ１２０μｍの長尺のポリビニルアルコールフィルムを一軸延伸（温度１１０℃、延伸倍率５倍）した。これをヨウ素０．０７５ｇ、ヨウ化カリウム５ｇ、水１００ｇの比率からなる水溶液に６０秒間浸漬し、次いでヨウ化カリウム６ｇ、ホウ酸７．５ｇ、水１００ｇの比率からなる６８℃の水溶液に浸漬した。これを水洗、乾燥し長尺の偏光膜を得た。
２．偏光板の作製
次いで、下記工程１〜５に従って、偏光膜と光学フィルムとを貼り合わせて偏光板を作製した。
【０１７７】
工程１：上記のように作製した長尺の光学フィルムを２ｍｏｌ／Ｌの水酸化ナトリウム溶液に４５℃で５０秒間浸漬し、次いで水洗、乾燥させた。
【０１７８】
同様に長尺のセルロースエステルフィルム（光学フィルムの基材として用いたもの）を２ｍｏｌ／Ｌの水酸化ナトリウム溶液に４５℃で５０秒間浸漬し、次いで水洗、乾燥させた。
【０１７９】
工程２：前述の長尺の偏光膜を固形分２質量％のポリビニルアルコール接着剤槽中に１〜２秒間浸漬した。
【０１８０】
工程３：工程２で偏光膜に付着した過剰の接着剤を軽く取り除き、それを工程１でアルカリ処理した光学フィルムとセルロースエステルフィルムで挟み込んで、積層配置した。
【０１８１】
工程４：２つの回転するローラにて２０〜３０Ｎ／ｃｍ²の圧力で約２ｍ／ｍｉｎの速度で張り合わせた。このとき気泡が入らないように注意して実施した。
【０１８２】
工程５：８０℃の乾燥機中にて工程４で作製した試料を２分間乾燥処理し、本発明の偏光板１を作製した。
【０１８３】
次いで、偏光板１の作製において、光学フィルム１に代えて、同じく光学フィルム２〜４０を用いた以外は同様にしてそれぞれ偏光板２〜４０を作製した。１０ｍ²当たりの故障を確認した。
【０１８４】
Ａ・・・泡、皺等による故障・欠陥なし
Ｂ・・・泡、皺等による故障・欠陥が２個以下
Ｃ・・・泡、皺等による故障・欠陥が３〜１０個未満
Ｄ・・・泡、皺等による故障・欠陥が１０個以上
市販の液晶表示パネル（ＮＥＣ製 カラー液晶ディスプレイ ＭｕｌｔｉＳｙｎｃ ＬＣＤ１５２５Ｊ 型名 ＬＡ−１５２９ＨＭ）の最表面の偏光板を注意深く剥離し、ここに偏光方向を合わせた本発明の偏光板１〜３４、比較例である偏光板３５〜４０を張り付けた。それぞれの液晶表示パネルについて、目視にて観察した。
《反射率の測定》
反射率は分光光度計Ｕ−４０００型（日立製作所製）を用いて、５度正反射の条件にて反射率の測定を行った。測定は、観察側の裏面を粗面化処理した後、黒色のスプレーを用いて光吸収処理を行い、フィルム裏面での光の反射を防止して反射率（４００〜７００ｎｍの波長について）の測定を行った。４５０〜６５０ｎｍの平均反射率を求めた。
【０１８５】
【表２】

【０１８６】
【表３】

【０１８７】
表２、表３から明らかなように、本発明の光学フィルムはカールが少なく、巻き形状での保管性に特に優れ、又偏光板作製における欠陥の発生や故障が少ないことが確認された。それに対して、比較例の光学フィルムはカールが生じ、巻き形状での保管性に劣り、偏光板作製における欠陥が発生しやすいことが確認された。特にクリアハードコート層や防眩層にアクリルウレタン系樹脂を使用したものはよりカールが少なく、偏光板作製における欠陥が更に少なくなることが確認された。
【０１８８】
又、本発明の偏光板を用いた液晶表示パネルは、反射光が少なく、表示性能に優れていることが確認された。又、偏光板１〜３４は指紋が付着しても容易に布でふき取ることが出来、特に偏光板１７〜３４は簡単に拭き取ることが出来た。又、布で擦っても傷つくことはなかった。
【０１８９】
実施例２
実施例１で作製した基材フィルム１のクリアハードコート層上に、下記の方法で第１酸化チタン層（屈折率２．１５、平均膜厚１５ｎｍ）、第１酸化珪素層（屈折率１．４６、平均膜厚３３ｎｍ）、第２酸化チタン層（屈折率２．１５、平均膜厚１１９ｎｍ）を順に形成した。基材フィルム１に変えて基材フィルム１７についても同様に形成した。
【０１９０】
実施例１と同様のプラズマ放電処理装置を使用し、電源は高周波電源（日本電子製）を使用し、連続周波数を１３．５６ＭＨｚとし、３Ｗ／ｃｍ²の電力を供給した。ロール電極は、ドライブを用いて基材フィルムの搬送に同期して回転させた。尚、電極間隙は１．４ｍｍ、反応ガスの圧力を大気圧＋２ｋＰａとして行った。プラズマ放電処理に用いた反応ガスの組成を以下に記す。
（第１、第２酸化チタン層（高屈折率層）形成用反応ガス）
不活性ガス（ヘリウム） ９９．６体積％
反応ガス（水素ガス） ０．２体積％
反応ガス（テトライソプロポキシチタン蒸気） ０．２体積％
（第１酸化珪素層（低屈折率層）形成用反応ガス）
不活性ガス（ヘリウム） ９９．６体積％
反応ガス（酸素ガス） ０．２体積％
反応ガス（テトラエトキシシラン蒸気） ０．２体積％
この第２酸化チタン層の上に、低屈折率層として下記表４に示すガス条件を採用して表面の低屈折率領域として第２酸化珪素層（屈折率１．４６、平均膜厚８６ｎｍ）を設けた。この表４に示すガス条件は以下の表５に記載のガス条件Ａ、ガス条件Ｂに表記する。
【０１９１】
【表４】

【０１９２】
表５に記載のようにガス条件Ａで所定膜厚の層を形成した後、引き続きガス条件Ｂで所定膜厚の層を形成した。得られた反射防止フィルムを用いて実施例１と同様にして偏光板を作製し、評価した。
【０１９３】
【表５】

【０１９４】
＊１：基材フィルム５４の表面をガス条件１４でプラズマ放電処理を行った
＊２：基材フィルム４６の表面をガス条件１３でプラズマ放電処理を行った
表５から明らかなように、本発明の光学フィルムはカールが少なく、巻き形状での保管性に特に優れ、又偏光板作製における欠陥の発生や故障が少ないことが確認された。それに対して、比較例の光学フィルムはカールが生じ、巻き形状での保管性に劣り、偏光板作製における欠陥が発生しやすいことが確認された。
【０１９５】
【発明の効果】
本発明によれば、保管安定性に優れ、カールが少なく、偏光板作製の際に凹みや泡の抱き込みが少ない反射防止フィルムを得ることができ、それを生産性高く製造出来る方法を見出すことが可能となり、顕著に優れた効果を奏する。更に該反射防止フィルムを組み込んだ偏光板、表示装置は泡、皺等による故障・欠陥が改善されている。
【図面の簡単な説明】
【図１】プラズマ放電処理装置の一例を示す図である。
【図２】回転電極と固定電極を有するプラズマ放電処理装置の一例を示す図である。
【符号の説明】
Ｆ セルロースエステルフィルム
Ｇ 反応ガス
Ｇ′ 排ガス
１０Ａ、１０Ｂ、１１０ 回転電極
１１Ａ、１１Ｂ、１１Ｃ、１１Ｄ Ｕターンロール
２０、２１ ガイドロール
３０ 反応ガス供給部
４０、１４０ ガス排気口
５０、１５０ 放電部
８０、１８０ 電源
８１、８２、１８１、１８２ 電圧供給手段
１１１ 固定電極
１２０、１２１ ガイドロール
１２２、１２３ ニップロール
１２４、１２５ 仕切板
１３０ 給気管
１３１ 反応ガス発生装置
１９０ プラズマ放電処理容器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antireflection film and a method for producing a low refractive index region formed by plasma discharge treatment under atmospheric pressure or a pressure in the vicinity thereof.
[0002]
[Prior art]
Higher quality such as higher definition of display devices and moving image display has been demanded, and further improvement of display performance has been demanded. It is desirable to perform antireflection processing on the front surface of the display device, and various antireflection layers have been proposed. Until now, a method of forming an antireflection layer by a method such as vapor deposition or sputtering has been performed, but a method of forming an antireflection layer by a coating method with higher productivity has also been proposed. Further, a plasma CVD method that can be expected to have higher productivity has also been proposed. Among them, plasma discharge treatment under atmospheric pressure or a pressure in the vicinity thereof is attracting attention as a method that can provide a plurality of layers at low cost.
[0003]
The antireflection layer is formed by laminating optical interference layers having different refractive indexes. As the number of layers stacked increases, the reflectance can be reduced. This antireflection layer is usually formed by laminating a high refractive index layer and a low refractive index layer.
[0004]
[Problems to be solved by the invention]
In recent years, it has been found that a film with an antireflection layer formed by a plasma CVD method is deteriorated in a wound state during storage in a roll state. This problem frequently occurs in a cellulose ester film having a film thickness of 80 μm or less, and in particular, this is remarkable in a thin film cellulose ester film having a thickness of 10 to 60 μm.
[0005]
Furthermore, it has been found that strong curl is generated by the plasma discharge treatment. Strong curl not only further deteriorates the roll film winding state, but also deteriorates the yield due to dents and bubble embedding during the preparation of a polarizing plate using an antireflection film, and its improvement has been demanded. .
[0006]
In addition, when an anti-reflection film using a cellulose ester film with a large curl is incorporated as a display element, the reflectivity may vary depending on the viewing angle, or the image may appear distorted, and as flat and flat as possible It was required to use a cellulose ester film.
[0007]
The present invention has been made in view of the above circumstances, and the object thereof is a flat antireflection film having excellent storage stability, less curling, and less dents and bubbles in the polarizing plate, and the same Is to provide a polarizing plate and a display device incorporating the antireflection film.
[0008]
[Means for Solving the Problems]
The object of the present invention consists of the following constitutions.
[0009]
  1. In the method for producing an antireflection film in which an antireflection layer having at least one high refractive index region and at least one low refractive index region thereon is formed on a base film,A method for producing an antireflection film that forms a low refractive index region by plasma discharge treatment under a pressure of 20 to 200 kPa of a reaction gas containing a compound represented by the following general formulas (1) to (4),The low refractive index region on the surface has a refractive index of 1.3 to 1.5, contains silicon, and has a region where the carbon content increases stepwise or continuously toward the surface. When the surface layer of the low refractive index region is formed using the compound represented by the following general formula (1) mainly for more than half of the film thickness on the base film side of the following general formulas (2) to (4) A method for producing an antireflection film, which comprises using any one of the compounds represented, or a mixture of any of these and a compound represented by the following general formula (1).
General formula (1) Si (OR₁) (OR₂) (OR_Three) (OR_Four)
General formula (2) R₁₁Si (OR₁) (OR₂) (OR_Three)
General formula (3) R₁₁R₁₂Si (OR₁) (OR₂)
General formula (4) R₁₁R₁₂R₁₃Si (OR₁)
-OR₁~ -OR_FourIs an alkoxy group which may have a substituent, and R₁₁~ R₁₃Is a substituent selected from an alkyl group, an alkenyl group, a hydrogen atom and a halogen atom which may have a substituent, and may be different or the same..
  2. The fluorine gas is included in the reaction gas when forming the surface layer of the low refractive index region,1The manufacturing method of antireflection film of description.
  3. In the method for producing a polarizing plate having an antireflection film, the above 1Or 2The manufacturing method of the polarizing plate characterized by using the manufacturing method of antireflection film of this.
[0020]
The present inventors have studied a method for improving various effects caused by curl generation by plasma discharge treatment without deterioration of the winding state even when stored in a roll state while having a sufficient reflection function for the antireflection film. However, they have intensively developed optical films that do not have such problems. As a result, by providing a region in which the carbon content increases stepwise or continuously toward the surface of the low refractive index region, curl is less, excellent storage in a wound state, and defects at the time of polarizing plate production It has been found that an antireflection film can be obtained in which occurrence and failure are reduced. In addition, the present inventors succeeded in obtaining an optical film excellent in antireflection performance and excellent in productivity and cost by laminating a plurality of antireflection layers by this plasma discharge treatment generated at atmospheric pressure or in the vicinity thereof.
[0021]
It was confirmed that the antireflection film having the antireflection layer formed by this method is excellent in storage stability of the roll film, has little curling, and has few dents and bubbles in the polarizing plate. The anti-reflection layer made by this method can be easily wiped off even if fingerprints adhere to it, has no effect on display quality, and has excellent antifouling and fingerprint wiping properties while having high film hardness. It was an antireflection layer having a low refractive index region. The antireflective layer having the low refractive index region can be easily wiped even if written on the surface with an oil-based magic pen or the like. In addition, the antireflection layer having a low refractive index region has excellent scratch resistance, and is 250 g / cm.²Even when it is rubbed 10 times with # 0000 steel wool loaded with a heavy weight, it is possible to impart scratch resistance with no scratches.
[0022]
Hereinafter, the present invention will be described in detail.
The layer structure of the anti-reflection film composed of a plurality of anti-reflection layers is provided with a hard coat layer in an arbitrary configuration on the transparent substrate as required, and the purpose is determined by the refractive index, the film thickness, the number of layers, and the layer order. The optical characteristics can be designed.
[0023]
Usually, the antireflection film is provided with an antireflection layer or an antiglare layer, a hard coat layer, a conductive layer, etc. on the surface of the transparent substrate on the viewer side, and on the surface opposite to the viewer side of the substrate. Has an easy-adhesion layer, a saponification treatment layer, and a pressure-sensitive adhesive layer for bonding it to the surface of a display polarizer or the like. The antireflection layer is usually achieved by combining a high refractive index layer having a higher refractive index than the substrate and a low refractive index layer having a lower refractive index than the substrate. As examples of the configuration, various types of single layer and multilayer are known, but as a multilayer one, a configuration composed of two layers of a high refractive index layer and a low refractive index layer from the substrate side, or three layers having different refractive indexes. Layered in the order of a medium refractive index layer (a layer having a higher refractive index than the base material or hard coat layer and a lower refractive index than the high refractive index layer), a high refractive index layer, and a low refractive index layer. It has been proposed to stack many layers. Among them, it is preferable to provide a medium refractive index layer, a high refractive index layer, and a low refractive index layer on a substrate having a hard coat layer in view of durability, optical characteristics, cost, productivity, and the like.
[0024]
A high refractive index layer (which may be provided with an intermediate refractive index layer) on the substrate surface, and a low refractive index layer are sequentially laminated thereon, and the optical film thicknesses of the high refractive index layer and the low refractive index layer are set to the wavelength of light. On the other hand, an optical interference layer is prepared by setting to a predetermined value, and an antireflection laminate is particularly preferable as the antireflection layer, and the refractive index and film thickness can be calculated and calculated by measuring the spectral reflectance. .
[0025]
The low refractive index layer of the antireflection film is formed by laminating a silicon compound, a mixture of a silicon compound and a fluorine compound, or a fluorine compound layer.
[0026]
In the present invention, the “high refractive index region” represents a high refractive index layer having a higher refractive index than the base material or the hard coat layer, and the “low refractive index region” represents a refractive index higher than that of the base material or the hard coat layer. Represents a low low refractive index layer. Each may be a single layer or a plurality of layers, and the composition may change in the thickness direction.
[0027]
The low refractive index region in the present invention preferably contains 20% or more of silicon, particularly preferably 20 to 45%. The contact angle in the low refractive index region is preferably 60 ° to 180 °, particularly preferably 80 to 150 °.
[0028]
The contents of carbon, silicon, oxygen and fluorine in the low refractive index region can be measured using an X-ray photoelectron spectrometer (hereinafter referred to as XPS apparatus). There is no particular limitation on the XPS device, and any model can be used. Before measuring the low refractive index region, the surface layer corresponding to a thickness of 5 to 10% of the thickness of the thin film is removed by etching as necessary in order to eliminate the influence of contamination. For the removal of the surface layer, it is preferable to use an ion gun that can use rare gas ions, and He, Ne, Ar, Xe, Kr, and the like can be used as ion species.
[0029]
In addition, changes in the carbon, silicon, and oxygen contents in the depth direction of the film are also determined using etching with rare gas ions. Rare gas ion etching is repeated to determine the element content on the film surface, and the change in the element content in the depth direction of the film is measured. Furthermore, in this invention, the average content rate of each element in a low refractive index area | region is made into the average of element content in each analysis point obtained as a result of conducting the said depth direction analysis. Here, the carbon content% is obtained by the following equation.
[0030]
Carbon content (%) = carbon content / (carbon content + silicon content + oxygen content) × 100
In the present invention, the method for providing the low refractive index region is not particularly limited, and the low refractive index region can be formed by coating, sputtering, vapor deposition, or plasma CVD, but is preferably formed by atmospheric pressure plasma CVD. In this atmospheric pressure plasma CVD method, a thin film is formed on a base film by plasma generated by supplying and discharging a reaction gas to a gap between opposing electrodes under atmospheric pressure or pressure near atmospheric pressure. Is.
[0031]
An embodiment of an atmospheric pressure plasma processing apparatus and a film forming method will be described below with reference to the drawings, but the present invention is not limited to this. In addition, the following explanation may include assertive expressions for terms and the like, but it shows a preferable example of the present invention and limits the meaning and technical scope of the terms of the present invention. It is not a thing.
[0032]
A method of forming an antireflection layer having a high refractive index region and at least one low refractive index region thereon will be described with reference to FIGS.
[0033]
Plasma discharge treatment under atmospheric pressure or a pressure near the atmospheric pressure for forming the antireflection layer is performed by using a plasma discharge treatment apparatus as described below.
[0034]
FIG. 1 is a diagram showing an example of a plasma discharge treatment apparatus. In FIG. 1, this apparatus has a pair of rotating electrodes 10A and 10B, and a power supply 80 capable of applying a voltage for generating plasma discharge is connected to the rotating electrodes 10A and 10B by a voltage supply means 81. Grounded. Rotating electrodes 10A and 10B convey a substrate (for example, a cellulose ester film) while being wound, and are preferably a roll electrode or a belt-like electrode, and FIG. 1 shows the roll electrode. A gap (electrode gap) between these rotating electrodes is a place where electric discharge is performed, and is set to an interval at which the cellulose ester film F can be conveyed. The gap between the electrodes becomes the discharge part 50. The gap between the electrodes is maintained at atmospheric pressure or a pressure near atmospheric pressure. The reaction gas G is supplied from the reaction gas supply unit 30 and the surface of the cellulose ester film F is subjected to plasma discharge treatment.
[0035]
Here, the cellulose ester film F unwound from the original winding roll or the cellulose ester film F conveyed from the previous step is transferred through the guide roll 20 while first contacting the rotating electrode 10A rotating in the transfer direction, A thin film is formed on the surface of the cellulose ester film F through the discharge part 50. The cellulose ester film F that has once exited from the discharge unit 50 is U-turned by the U-turn rolls 11A to 11D, and is then transferred while being in contact with the rotating electrode 10B rotating in the opposite direction to the rotating electrode 10A. Then, plasma discharge treatment is further performed on the surface of the cellulose ester film F on which the thin film has been formed, and a thin film is formed. The U-turn is usually performed in about 0.1 seconds to 1 minute. The reaction gas G used for the treatment is discharged from the gas discharge port 40 as exhaust gas G ′ after the reaction.
[0036]
In the figure, the thin film formed on the cellulose ester film F is omitted. The cellulose ester film F having a thin film formed on the surface is conveyed in the direction of the next process or a take-up roll (not shown) via the guide roller 21. Accordingly, the cellulose ester film F is subjected to plasma discharge treatment by reciprocating the discharge unit 50 in a state of being in close contact with the rotary electrodes 10A and 10B.
[0037]
Although not shown in the drawing, the devices such as the rotating electrodes 10A and 10B, the guide rolls 20 and 21, the U-turn rolls 11A to 11D, the reactive gas supply unit 30, and the gas discharge port 40 are in a plasma discharge processing vessel that is shielded from the outside. It is preferable that it is enclosed and enclosed. Although not shown, a temperature control medium for controlling the temperature of the rotating electrodes 10A and 10B is circulated as necessary to control each electrode surface temperature to a predetermined value. . In addition, when a necessary film thickness cannot be obtained by one process, a plurality of similar apparatuses can be used to continuously form a thin film.
[0038]
FIG. 2 is a diagram illustrating an example of a plasma discharge processing apparatus having a rotating electrode and a fixed electrode. A cellulose ester film F having a rotating electrode 110 and a plurality of fixed electrodes 111 arranged so as to face the rotating electrode 110 and being conveyed from a former winding roll or a preceding process (not shown) passes through a guide roll 120 and a nip roll 122 to rotate the rotating electrode. The cellulose ester film F is transferred in synchronization with the rotation of the rotating electrode 110 while being in contact with the rotating electrode 110, and is supplied to the discharge unit 150 under the atmospheric pressure or in the vicinity thereof by the reaction gas generator 131. The prepared reaction gas G is supplied from the supply pipe 130, and a thin film is formed on the cellulose ester film surface facing the fixed electrode 111.
[0039]
A power supply 180 capable of applying a voltage for generating plasma discharge is connected to the rotating electrode 110 and the fixed electrode 111 by a voltage supply means 181, and is grounded by 182. Further, the rotating electrode 110, the fixed electrode 111, and the discharge unit 150 are covered with a plasma discharge processing vessel 190 and are shielded from the outside. The treated exhaust gas G ′ is discharged from a gas exhaust port 140 at the lower part of the processing chamber. The exhaust gas G ′ can be recovered and the rare gas can be reused after removing foreign substances and dispersion by filtering, activated carbon treatment, cooling, or the like. The cellulose ester film F subjected to the plasma discharge treatment is conveyed to the next process or a winding roll (not shown) through the nip roll 123 and the guide roll 121.
[0040]
Separating plates 124 and 125 for the outside world are provided at the nip rolls 122 and 123 at the entrance / exit of the plasma discharge treatment container, and air accompanying the cellulose ester film F from the outside world together with the nip roll 122 is provided. At the outlet, the reaction gas G or the exhaust gas G ′ is prevented from leaking to the outside. Although not shown, the rotating electrode 110 and the fixed electrode 111 circulate a temperature-controlled medium for temperature adjustment as necessary.
[0041]
Thus, in this invention, it is preferable that the cellulose-ester film in which a thin film is formed is plasma-discharge-treated, conveying on a rotating electrode.
[0042]
The surface where the rotating electrode is in contact with the cellulose ester film is required to have high smoothness, and the surface roughness of the surface of the rotating electrode is 10 μm or less (Rmax) as the maximum surface roughness specified by JIS-B-0601. It is preferably 8 μm or less, more preferably 7 μm or less, and particularly preferably 3 μm or less.
[0043]
The surface of the electrode used in the present invention is preferably coated with a solid dielectric, and in particular, a conductive base material such as a metal is preferably coated with the solid dielectric. Solid dielectrics include plastics such as polytetrafluoroethylene and polyethylene terephthalate, glass, silicon dioxide, aluminum oxide (Al₂O_Three), Zirconium oxide (ZrO)₂), Titanium oxide (TiO₂), And double oxides such as barium titanate. Particularly preferred is a ceramic-coated dielectric that has been ceramic-sprayed and then sealed with an inorganic material. Here, examples of the conductive base material such as metal include metals such as silver, platinum, stainless steel, aluminum, iron, titanium, and a titanium alloy. Stainless steel is preferable from the viewpoint of processing.
[0044]
As the lining material, silicate glass, borate glass, phosphate glass, germanate glass, tellurite glass, aluminate glass, vanadate glass, etc. are preferably used. However, among these, borate glass is more preferably used because it is easy to process.
[0045]
In the present invention, it is preferable that the electrode can be heated or cooled as necessary from the back side (inside). When the electrode is a belt, it can be cooled with gas from the back side, but with a rotating electrode using a roll, the medium can be circulated and supplied to control the temperature of the electrode surface and the temperature of the cellulose ester film. preferable. As the medium, an insulating material such as distilled water, oil, particularly silicon oil is preferably used.
[0046]
Although the temperature of the cellulose-ester film in the case of discharge processing changes with process conditions, room temperature-200 degrees C or less are preferable, More preferably, they are room temperature-120 degrees C or less, More preferably, they are 50-110 degrees C.
[0047]
It is desirable to prevent temperature unevenness particularly in the width direction of the cellulose ester film surface during the discharge treatment. The temperature unevenness is preferably within ± 5 ° C., more preferably within ± 1 ° C., and particularly preferably within ± 0.1 ° C.
[0048]
In the present invention, the electrode gap is determined in consideration of the thickness of the solid dielectric, the applied voltage and frequency, the purpose of using plasma, and the like. The shortest distance between the solid dielectric and the electrode when a solid dielectric is placed on one of the electrodes, and the distance between the solid dielectrics when a solid dielectric is placed on both of the electrodes is uniform in any case From the viewpoint of generating discharge plasma, 0.5 mm to 20 mm is preferable, and 1 mm ± 0.5 mm is particularly preferable.
[0049]
In the present invention, the flow rate of the mixed gas generated by the gas generator is controlled in the discharge portion of the electrode gap and introduced into the plasma discharge portion from the reaction gas supply port. The concentration and flow rate of the reaction gas are appropriately adjusted, but it is preferable to supply the processing gas to the electrode gap at a sufficient speed with respect to the cellulose ester film transport speed. Usually, it is supplied at a rate of 0.1 to 300 L / min per 1 cm width of the film to be processed. In the discharge section, it is desirable to set the flow rate and discharge conditions so that most of the supplied reaction gas reacts and is used for thin film formation.
[0050]
In order to prevent the atmosphere from being mixed into the discharge part and the reaction gas from leaking out of the apparatus, the electrode and the cellulose ester film being transferred are preferably surrounded and shielded from the outside. In the present invention, the atmospheric pressure of the discharge part is maintained at atmospheric pressure or a pressure in the vicinity thereof.
[0051]
Here, the vicinity of atmospheric pressure represents a pressure of 20 to 200 kPa, but 93 to 110 kPa is preferable in order to preferably obtain the effects described in the present invention. The discharge part is preferably slightly positive with respect to the atmospheric pressure outside the apparatus, and more preferably atmospheric pressure outside the atmospheric pressure plasma processing apparatus +0.1 kPa to 5 kPa.
[0052]
In the atmospheric pressure plasma processing apparatus useful for the present invention, one electrode is connected to a power source to apply a voltage, and the other electrode is grounded to generate discharge plasma in order to generate stable plasma. preferable.
[0053]
The value of the voltage applied to the electrode from the high frequency power source is appropriately determined. For example, the voltage is about 0.5 to 10 kV, the applied frequency is adjusted to 1 kHz to 150 MHz, and the waveform is a sine wave even if it is a pulse wave. It is good. In particular, it is preferable to set the frequency to more than 100 kHz and 50 MHz or less because a preferable discharge part (discharge space) is obtained.
[0054]
The discharge density in the discharge part is 5 to 1000 W · min / m.²In particular, 50 to 500 W · min / m²It is desirable that
[0055]
It is desirable that the plasma discharge processing section is appropriately surrounded by a Pyrex (R) glass processing container or the like, and it is also possible to use a metal 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 subjected to ceramic spraying to achieve insulation. In addition, the reaction gas and the exhaust gas can be appropriately supplied to the discharge unit or exhausted by surrounding the discharge unit, the side surface of the rotating electrode, the side surface of the cellulose ester film transport unit, and the like.
[0056]
The reaction gas used for forming the antireflection layer will be described.
The antireflection layer is formed by laminating layers having different refractive indexes, and main metal compound layers having respective refractive indexes will be described below.
[0057]
The antireflection layer includes a layer of titanium oxide or zirconium oxide that forms a high refractive index layer, a layer of tin oxide or zinc oxide that forms a middle refractive index layer, a silicon oxide that forms a low refractive index layer, or an oxide layer. It is preferably configured by laminating a mixture of a silicon compound such as silicon and a fluorine compound, or a layer of a fluorine compound.
[0058]
The reactive gas used in the present invention varies depending on the type of thin film provided on the base film, but basically an inert gas such as a rare gas or nitrogen gas and a reactive gas for forming the thin film are mixed. Reaction gas. It is preferable to contain 0.01-10 volume% of reactive gas with respect to reaction gas, More preferably, it is 0.1-5 volume%.
[0059]
The concentration of the inert gas in the reaction gas is preferably 90% by volume or more in order to generate a stable plasma discharge, and desirably 90 to 99.99% by volume. The inert gas is used to generate a stable plasma discharge, and the reactive gas is ionized or radicalized in the plasma to form a thin film by depositing or adhering to the substrate surface.
[0060]
Examples of the inert gas include noble gases, and include group 18 elements in the periodic table, specifically helium, neon, argon, krypton, xenon, radon, etc., in order to obtain the effects described in the present invention. Helium and argon are preferably used.
[0061]
In the reactive gas for forming the antireflection layer, a titanium compound for forming a high refractive index layer, a tin compound for forming a middle refractive index layer, and a silicon compound for forming a low refractive index layer will be described.
[0062]
The antireflection film of the present invention having an antireflection layer is obtained by laminating each refractive index layer on a substrate directly or via another layer. Lamination may be performed, for example, at atmospheric pressure or in the vicinity thereof. Three layers can be laminated by successively processing, for example, three plasma discharge treatment devices in series (medium refractive index layer / high refractive index layer / low refractive index layer) in a reaction gas atmosphere under the pressure of . This continuous lamination process is suitable for the production of the optical film of the present invention from the viewpoint of stability of quality and improvement of productivity. Further, instead of continuously laminating, each layer may be laminated after being processed and wound up after processing and sequentially.
[0063]
The reactive gas for the antireflective layer of the antireflective film of the present invention can be used without limitation as long as it is a compound capable of obtaining an appropriate refractive index. As a reactive gas for forming a middle refractive index layer, a titanium compound is a tin compound or a mixture of a titanium compound and a silicon compound (or a silicon compound that forms a layer formed of a titanium compound for forming a high refractive index and a low refractive index layer). As the reactive gas for forming the low refractive index layer, a silicon compound, a fluorine compound, or a mixture of a silicon compound and a fluorine compound can be preferably used. In order to adjust the refractive index, two or more of these compounds may be used as a reactive gas for forming any layer.
[0064]
Examples of titanium compounds used in the reactive gas for forming a high refractive index layer useful in the present invention include organic titanium compounds, titanium hydrogen compounds, and titanium halides. Examples of organic titanium compounds include triethyl titanium and trimethyl titanium. , Triisopropyl titanium, tributyl titanium, tetraethyl titanium, tetraisopropyl titanium, tetrabutyl titanium, triethoxy titanium, trimethoxy titanium, triisopropoxy titanium, tributoxy titanium, tetraethoxy titanium, tetraisopropoxy titanium, methyl dimethoxy titanium, ethyl Trititanium, methyltriisopropoxytitanium, tetradimethylaminotitanium, dimethyltitanium diacetoacetonate, ethyltitanium triacetoacetonate, etc. Containing compounds, Jichitan hydrogen compound such as titanium halide, can be mentioned trichloro titanium, titanium tetrachloride or the like, both can be preferably used in the present invention. Two or more of these reactive gases can be mixed and used at the same time.
[0065]
Examples of the tin compound used for the reactive gas for forming the middle refractive index layer useful in the present invention include an organic tin compound, a tin hydrogen compound, and a tin halide. Examples of the organic tin compound include tetraethyltin and tetramethyltin. , Di-n-butyltin diacetate, tetrabutyltin, tetraoctyltin, tetraethoxytin, methyltriethoxytin, diethyldiethoxytin, triisopropylethoxytin, diethyltin, dimethyltin, diisopropyltin, dibutyltin, diethoxytin , Dimethoxytin, diisopropoxytin, dibutoxytin, tin dibutyrate, tin diacetoacetonate, ethyltin acetoacetonate, ethoxytin acetoacetonate, dimethyltin diacetoacetonate, tin hydrogen compounds, etc. Can include tin dichloride, tin tetrachloride, etc. Stomach, can be preferably used. Two or more of these reactive gases may be mixed and used at the same time. The tin oxide layer thus formed has a surface resistivity of 10¹¹Ω / cm²Or less, more preferably 10⁸Ω / cm²Since it can be lowered to the following, it is also useful as an antistatic layer.
[0066]
Examples of the silicon compound used in the reactive gas for forming the low refractive index layer useful in the present invention include an organic silicon compound, a silicon hydrogen compound, a silicon halide compound, etc. Examples of the organic silicon compound include tetraethyl Silane, tetramethylsilane, tetraisopropylsilane, tetrabutylsilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diethylsilanediacetacetonate, methyltrimethoxysilane, methyltri Examples of silicon hydride compounds such as ethoxysilane and ethyltriethoxysilane include tetrahydrogen silane and hexahydrogen disilane, and examples of halogenated silicon compounds include tetrachlorosilane, methyltrichlorosilane, and diethyldichlorosilane. It can be mentioned, both can be preferably used in the present invention.
[0067]
As a material for forming the low refractive index layer, it is preferable to use a (silicon oxide) sol obtained by hydrolyzing an organosilicon compound, particularly a silicon alkoxide containing tetraalkoxysilane. This sol can be prepared by dissolving an organosilicon compound in an organic solvent suitable for coating and performing hydrolysis using a certain amount of water. Preferable examples of the organosilicon compound used for forming the sol use compounds represented by the following general formulas (1) to (4). In particular, when the surface layer of the low refractive index region is formed by using a compound represented by the following general formula (1) mainly for more than half of the film thickness of the low refractive index region, the following general formulas (2) to (4) It is preferable to use any one of the compounds represented by the formula (1) or a mixture of any one of these and the compound represented by the following general formula (1).
[0068]
General formula (1) Si (OR₁) (OR₂) (OR_Three) (OR_Four)
General formula (2) R₁₁Si (OR₁) (OR₂) (OR_Three)
General formula (3) R₁₁R₁₂Si (OR₁) (OR₂)
General formula (4) R₁₁R₁₂R₁₃Si (OR₁)
-OR₁~ -OR_FourIs an alkoxy group which may have a substituent, and R₁₁~ R₁₃Are substituents selected from an alkyl group, an alkenyl group, a hydrogen atom, and a halogen atom which may have a substituent, and may be different or the same.
[0069]
Specific examples of this organosilicon compound include tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetra i-propoxysilane, tetra n-butoxysilane, tetra sec-butoxysilane, tetra-t-butoxysilane and the like. Alkoxide silanes: methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, Vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysila , Γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane Chloromethyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane , Β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxy Silane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxy Silane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriphenoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltri Methoxysilane, β-glycy Xylbutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, (3,4 -Epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxy Silane, β- (3,4-epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, γ- (3,4-epoxy Rohexyl) propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxy Silane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, trialkoxysilane such as δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, triacyloxysilane, triphenoxysilanes; dimethyldimethoxysilane, Phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ Methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane , Methylvinyldimethoxysilene, methylvinyldiethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylmethyldiethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypro Rumethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ- Glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxyethoxysilane, γ-glycidoxypropylmethyldimethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylmethyl Diacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, γ Dialkoxysilanes such as glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldiethoxysilane, diphenoxysilane, diacyloxysilane, trimethylethoxysilane, trimethylmethoxysilane, fluoroalkylsilane, hexamethyldisilane, hexamethyl And disiloxanes.
[0070]
Two or more of these organosilicon compounds can be used for the purpose of adjusting optical properties such as the required refractive index of the film and for the purpose of surface hardness, wetting, adhesion, and crack prevention. In particular, the use of an organosilicon compound containing an epoxy group or a glycidoxy group is suitable for the purpose of preventing cracks and imparting dyeing properties, and has high added value.
[0071]
The hydrolysis of the silicon compound is preferably performed by dissolving in a suitable solvent. Examples of the solvent include alcohols such as methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate, and butyl acetate, ketones, esters, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, or These mixtures are mentioned. The silicon compound is dissolved in the solvent so as to be 0.1% by mass or more, preferably 0.1 to 10% by mass in terms of silicon oxide generated when the silicon compound is 100% hydrolyzed and condensed. If the concentration of the silicon oxide sol is less than 0.1% by mass, the formed sol film cannot sufficiently exhibit the desired characteristics, while if it exceeds 10% by mass, it becomes difficult to form a transparent homogeneous film. Moreover, in this invention, if it is in the range of the above solid content, it is also possible to use an organic substance and an inorganic substance binder together.
[0072]
Water more than the amount necessary for hydrolysis is added to this solution, and stirring is performed at a temperature of 15 to 35 ° C., preferably 22 to 28 ° C., for 0.5 to 48 hours, preferably 2 to 24 hours. In the hydrolysis, it is preferable to use a catalyst. As these catalysts, acids such as hydrochloric acid, nitric acid, sulfuric acid or acetic acid are preferable, and these acids are added in an amount of about 0.001 to 20 mol / L, preferably 0.005 to 0.005. It can be added as an aqueous solution of about 5 mol / L, and water in the aqueous solution can be used as water for hydrolysis, but it is preferable to add so that the pH of the whole solution is 4-10. In addition to the acid, a base such as ammonia can be used. The silicon oxide sol thus obtained is a colorless and transparent liquid, is a stable solution having a pot life of about 1 month, has good wettability with respect to the substrate, and is excellent in coating suitability.
[0073]
The (silicon oxide) sol obtained by hydrolysis of the silicon compound is in a liquid state and has a viscosity in a range that can be applied by a normal coating operation. The applied temperature is 1 Pa · s or less, and further 0.1 Pa · s. The following are preferred. A liquid material having a viscosity higher than this makes it difficult to form a uniform coating film. As a coating method, a method used in a normal coating operation can be used. For example, a spin coating method, a dip method, a spray method, a roll coater method, a meniscus coater method, a flexographic printing method, a screen printing method, a beat coater method. And a micro gravure coater method.
[0074]
In the present invention, the following fluorine compounds can be used. Two or more of these reactive gases can be mixed and used at the same time. In addition, two or more of these tin compounds, titanium compounds, and silicon compounds may be appropriately mixed and used for fine adjustment of the refractive index.
[0075]
In addition to the silicon compound, a fluorine compound may be used for the low refractive index layer. A mixture of a silicon compound and a fluorine compound can be used for the low refractive index layer. The fluorine compound may be a fluorocarbon gas or a fluorohydrocarbon gas. For example, tetrafluoromethane, hexafluoroethylene, hexafluoropropylene, octafluorocyclobutane, difluoromethane, tetrafluoromethane, and the like. Ethane fluoride, propylene tetrafluoride, propylene trifluoride, methane monochloride trifluoride methane, monochloride difluoride methane, dichloride tetrafluorocyclobutane, hexafluoroacetone, trifluoroacetic acid, trifluoromethanol, pentafluoroethanol, Examples include 1-hydro-1,2,3-hexafluoropropanol.
[0076]
When a fluorine compound is mixed with the reaction gas, the fluorine compound in the reaction gas is preferably 0.01 to 5% by volume, more preferably 0.1 to 0.5% by volume. Further, when a fluorine compound is mixed with a reaction gas and used, the energy on the surface of the thin film is reduced, water repellency or antifouling property can be imparted, and the thin film formed from the fluorine compound is also a low refractive index layer. I can do it. When the fluorine compound is a gas at normal temperature and pressure, it can be used in the present invention most easily because it can be used as it is as a component of the reaction gas. However, when the fluorine compound is liquid or solid at normal temperature and normal pressure, it can be vaporized by a method such as heating and decompression, or it can be dissolved in an appropriate solvent and bubbled with a rare gas. May be. As the solvent, organic solvents such as methanol, ethanol, isopropanol, butanol, n-hexane, acetone, methyl ethyl ketone, and mixed solvents thereof can be used.
[0077]
The above-mentioned organotin compound, organotitanium compound or organosilicon compound is preferably a metal hydride compound or metal alkoxide from the viewpoint of handling, and is free from corrosiveness, generation of harmful gases, and less contamination in the process. Alkoxides are preferably used. In addition, when the above-described organotin compound, organotitanium compound, or organosilicon compound is introduced between electrodes that are discharge spaces, these may be in a gas, liquid, or solid state at normal temperature and pressure. In the case of gas, it can be introduced into the discharge space as it is, but in the case of liquid or solid, it is used after being vaporized by means such as heating, decompression or ultrasonic irradiation. When an organic tin compound, an organic titanium compound or an organic silicon compound is vaporized by heating, a metal alkoxide having a boiling point of 200 ° C. or less, such as metal tetraethoxide and metal tetraisopropoxide, is liquid at room temperature. It is used suitably for formation of. The metal alkoxide may be used after being diluted with a solvent. In this case, the metal alkoxide may be used as a reaction gas after being evaporated into a rare gas by a vaporizer or the like.
[0078]
Regarding the reactive gas, from the viewpoint of forming a uniform thin film on the substrate by discharge plasma treatment, the content in the reactive gas is preferably 0.01 to 10% by volume, more preferably 0.01%. ~ 1% by volume.
[0079]
The intermediate refractive index layer can also be obtained by appropriately mixing the silicon compound, the titanium compound or the tin compound in accordance with the target refractive index.
[0080]
Furthermore, a component selected from oxygen, ozone, hydrogen peroxide, carbon dioxide, carbon monoxide, and hydrogen may be used as the reactive gas in the reactive gas used for forming each of these layers. The reaction is preferably promoted by containing 0.01 to 10% by volume, more preferably 0.1 to 5% by volume, the hardness of the thin film can be remarkably improved, and a dense and high-quality thin film can be formed. . In particular, it is preferable to add oxygen or hydrogen.
[0081]
In the antireflection film of the present invention, the low refractive index region on the surface can be formed as follows, but it is not particularly limited to this method. First, a high refractive index layer (for example, a titanium oxide layer or a zirconium oxide layer) is formed by the above-described method, and a silicon oxide layer is formed thereon. For example, by using a reaction gas A having a component represented by the general formula (1) such as tetraethoxysilane, tetramethoxysilane, or triethoxysilane, a layer mainly containing silicon oxide is formed by an atmospheric pressure plasma method. I can do it. At this time, the carbon content contained in the film is less than 5%. If it exceeds 5%, the film becomes soft and scratches are likely to occur. It is preferable to form a film thickness of ½ or more with respect to the film thickness of the predetermined low refractive index region. Next, methyltriethoxysilane, dimethyldiethoxysilane, ethyltriethoxysilane, diethyldiethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, fluoroalkylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, hexamethyldisilane, Atmospheric pressure using the reaction gas B having a silicon compound represented by the general formulas (2) to (4) such as hexamethyldisiloxane, phenyltriethoxysilane, aminopropyltriethoxysilane, methacryloxypropyltrimethoxysilane, etc. A layer having silicon oxide with a high carbon content is formed by a plasma method. That is, by changing the composition of the reaction gas during the atmospheric pressure plasma treatment from the reaction gas A to the reaction gas B, a silicon oxide layer having a higher carbon content as it becomes the surface can be formed. For example, when using a processing apparatus provided with a plurality of discharge portions for plasma processing, a thin film is formed using the reactive gas A at the beginning of the processing, and then a mixed gas of the reactive gas B and the reactive gas A is used. To form a thin film. A thin film is formed while the reaction gas B gradually increases in the mixing ratio of the reaction gas B and the reaction gas A, and the reaction gas B is further used to form a thin film. By doing so, it is possible to form a low refractive index region in which the carbon content gradually increases toward the surface. The carbon content on the surface side is preferably 5 to 60%, more preferably 6 to 50%, and even more preferably 7 to 40%. By increasing the carbon content of the low refractive index region on the surface layer side, it is possible to obtain an antireflection film with little curling and roll film deterioration. In order to change the carbon content, not only the kind and composition of the reaction gas may be changed, but also the discharge conditions of the plasma treatment may be adjusted as appropriate. Further, when forming a low refractive index region having a high carbon content, a fluorine compound is contained in the reaction gas, and fluorine is bonded to the carbon constituting the low refractive index region, or the fluorine is substituted. A group can be introduced. Alternatively, a fluorine compound layer can be formed on the surface of the low refractive index region having a high carbon content by performing plasma discharge treatment using a reactive gas containing a fluorine compound. This not only provides an antireflection film with less curling and less roll shape deterioration of the roll film, but also can impart antifouling properties and good fingerprint wiping properties. Fluorine compounds that can be used include fluorinated saturated hydrocarbons, fluorinated unsaturated hydrocarbons, fluorinated alicyclic hydrocarbons, or SF₆Sulfur fluoride such as is preferably used. Specifically, in addition to the fluorine compound that can be used for forming the low refractive index layer, hexafluorocyclopropane (Freon C-216), 1,1,2,2-tetrachlorotetrafluorocyclobutane (Freon C-314). 1,2-dichlorohexafluorocyclobutane (Freon C-316), monochloroheptafluorocyclobutane (Freon C-317), octafluorocyclobutane (Freon C-318, OFB), 1,2,2-trichloro-3,3 , 4,4-tetrafluorocyclobutane (Freon C-324), 1,1-dichloro-2,2,3,3-tetrafluorocyclobutane (Freon C-334), 1-chloro-2,2,3,3 -Tetrafluorocyclobutane (Freon C-344), 1,1,2,2-tetrafluorocyclobutane (Freon C- 54), 1,2-dichlorotetrafluorocyclobutene (Freon C-1314), hexafluorocyclobutene (Freon C-1316), perfluorocyclopentane, perfluorocyclohexane, perfluorocycloheptane, and the like. Examples of the fluorine-containing compound in which some or all of the hydrogen atoms of the unsaturated hydrocarbon are substituted with a halogen group containing a fluorine atom include trichloromonofluoroethylene (CFC 1111), 1,2-dichlorodifluoroethylene (CFC 1112), 1 , 1-dichlorodifluoroethylene (Freon 1112a), monochloro-1,1,2-trifluoroethylene (Freon 1113), tetrafluoroethylene (Freon 1114), 1,2-dichloro-2-fluoroethylene (Freon 1121), 1,1-di 1-chloro-2,2-difluoroethylene (fluorocarbon 1122), 1-chloro-1,2-difluoroethylene (fluorocarbon 1122a), trifluoroethylene (fluorocarbon 1123), 1 -Chloro-2-fluoroethylene (Freon 1131), 1-chloro-1-fluoroethylene (Freon 1131a), 1,2-difluoroethylene (Freon 1142), 1,1-fluoroethylene (Freon 1142a), fluoroethylene ( Freon 1141), hexafluoropropylene (HFP), fluoropropylene, difluoropropylene, trifluoropropylene, tetrafluoropropylene, pentafluoropropylene, octafluorobutene, fluorobutene, difluorobutene, trifluorobutene , Tetrafluorobutene, pentafluorobutene, hexafluorobutene, heptafluorobutene, perfluoropentane, and the like can be used. In the present invention, as the fluorine compound in the reaction gas, for example, fluorinated methane, hexafluoropropylene, octafluorocyclobutane and the like are preferably used.
[0082]
In the present invention, a fluorine compound can be imparted to the surface of the low refractive index region by performing plasma treatment using a reactive gas containing these.
[0083]
Next, the base material will be described.
As the substrate, cellulose ester support such as cellulose triacetate, polyester support, polycarbonate support, polystyrene support, and gelatin, polyvinyl alcohol (PVA), acrylic resin, polyester resin, cellulose resin on the upper layer of these supports It is possible to use a support or the like coated with the same. The substrate according to the present invention may be used alone as the above-mentioned support, and an anti-glare layer or a clear hard coat layer may be coated on the above-mentioned support, or a back coat layer or an alignment layer. A substrate coated with a liquid crystal layer or an antistatic layer can be used as a substrate.
[0084]
Specific examples of the support include polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyethylene films, polypropylene films, cellophane, cellulose acetate films, cellulose diacetate films, cellulose acetate butyrate films, and cellulose acetate propio. Nate film, cellulose acetate phthalate film, cellulose triacetate, cellulose ester film such as cellulose nitrate or derivatives thereof, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film , Norbornene resin film, polymethylpe Ten film, polyether ketone film, polyimide film, polyether sulfone film, polysulfone film, polyether ketone imide film, polyamide film, fluororesin film, nylon film, polymethyl methacrylate film, acrylic film or polyarylate film Can be mentioned.
[0085]
These materials can be used alone or in combination as appropriate. Among them, a film using a resin such as ZEONEX, ZEONEA (manufactured by Nippon Zeon Co., Ltd.), or ARTON (manufactured by JSR Corporation) can be used as the norbornene resin-based film. Furthermore, even for materials with a large intrinsic birefringence such as polycarbonate, polyarylate, polysulfone and polyethersulfone, conditions such as solution casting and melt extrusion, and further stretching conditions in the longitudinal and lateral directions are set as appropriate. Can be obtained. The substrate is not limited to the above. A film thickness of 10 to 1000 μm is preferably used.
[0086]
As the substrate, it is preferable to use a cellulose ester film because a laminate having a low reflectance can be obtained. From the viewpoint of preferably obtaining the effects described in the present invention, as the cellulose ester, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate are preferable, and among them, cellulose acetate butyrate and cellulose acetate propionate are preferably used.
[0087]
In the present invention, these cellulose ester films usually have a film thickness of 10 to 500 μm, but it is particularly preferable to use a film having a film thickness of 10 to 80 μm.
[0088]
In particular, when the substitution degree of the acetyl group is X and the substitution degree of the propionyl group and / or the butyryl group is Y, a mixed fatty acid ester of cellulose in which X and Y simultaneously satisfy the following formulas (1) and (2) is used. An antireflective film in which a high refractive index layer and a low refractive index layer are provided on a support or a substrate prepared in this manner is preferably used.
[0089]
Formula (1): 2.3 ≦ X + Y ≦ 3.0
Formula (2): 0.1 ≦ Y ≦ 1.2
When cellulose ester is used for the substrate, the cellulose as the raw material for the cellulose ester is not particularly limited, and examples include cotton linters, wood pulp (derived from coniferous trees, derived from broadleaf trees), kenaf and the like. Moreover, the cellulose ester obtained from them can be mixed and used in arbitrary ratios, respectively. In these cellulose esters, when the acylating agent is an acid anhydride (acetic anhydride, propionic anhydride, butyric anhydride), an organic solvent such as acetic acid or an organic solvent such as methylene chloride is used for the cellulose raw material. It can obtain by making it react using a protic catalyst.
[0090]
The acylating agent is acid chloride (CH_ThreeCOCl, C₂H_FiveCOCl, C_ThreeH₇In the case of COCl), the reaction is carried out using a basic compound such as an amine as a catalyst. Specifically, it can be synthesized with reference to the method described in JP-A-10-45804. Cellulose esters are prepared by mixing and reacting the above acylating agent amounts in accordance with the degree of substitution. In cellulose esters, these acyl groups react with the hydroxyl groups of cellulose molecules. Cellulose molecules are composed of many glucose units linked together, and the glucose unit has three hydroxyl groups. The number of acyl groups derived from these three hydroxyl groups is called the degree of substitution. For example, cellulose triacetate has an acetyl group bonded to three hydroxyl groups of a glucose unit (actually 2.6 to 3.0).
[0091]
As the cellulose ester, a cellulose ester to which a propionate group or a butyrate group is bonded in addition to an acetyl group such as cellulose acetate propionate, cellulose acetate butyrate, or cellulose acetate propionate butyrate is particularly preferably used. The butyryl group that forms butyrate may be linear or branched.
[0092]
Cellulose acetate propionate containing a propionate group as a substituent has excellent water resistance and is useful as a film for liquid crystal image display devices.
[0093]
The measuring method of the substitution degree of an acyl group can be measured according to the provisions of ASTM-D817-96.
[0094]
The number average molecular weight of the cellulose ester is preferably from 70,000 to 250,000, more preferably from 80,000 to 150,000, since the mechanical strength when molded is strong and the dope viscosity becomes appropriate.
[0095]
Here, the number average molecular weight of the cellulose ester is determined as follows.
<Measurement of number average molecular weight of cellulose ester>
Measured by high performance liquid chromatography under the following conditions.
[0096]
Solvent: Acetone
Column: MPW × 1 (manufactured by Tosoh Corporation)
Sample concentration: 0.2 mass / v%
Flow rate: 1.0 ml / min
Sample injection volume: 300 μl
Standard sample: polymethyl methacrylate (Mw = 188,200)
Temperature: 23 ° C
These cellulose esters are, as will be described later, a cellulose ester solution (dope) generally called a casting method, for example, an endless metal belt for infinite transport or a support for casting of a rotating metal drum (hereinafter simply supported). It is manufactured by casting a dope from a pressure die on top of the pressure die (casting), and as an organic solvent used to prepare these dopes, cellulose ester can be dissolved, and A suitable boiling point is preferable, for example, methylene chloride, methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trimethyl. Fluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-diph Oro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2, 2,3,3,3-pentafluoro-1-propanol, nitroethane, 1,3-dimethyl-2-imidazolidinone and the like, but organic halogen compounds such as methylene chloride, dioxolane derivatives, methyl acetate, Ethyl acetate, acetone and the like are mentioned as preferable organic solvents (that is, good solvents).
[0097]
Moreover, as shown in the following film forming process, when drying a solvent from the web (dope film | membrane) formed on the support body in a solvent evaporation process, the organic solvent used from a viewpoint which prevents foaming in a web The boiling point of the good solvent is, for example, methylene chloride (boiling point 40.4 ° C), methyl acetate (boiling point 56.32 ° C), acetone (56.3 ° C), ethyl acetate. (76.82 ° C.).
[0098]
Among the above good solvents, methylene chloride and methyl acetate, which are excellent in solubility, are preferably used.
[0099]
In addition to the organic solvent, it is preferable to contain 0.1 to 30% by mass of an alcohol having 1 to 4 carbon atoms. It is particularly preferable that the alcohol is contained at 10 to 30% by mass. After casting the above dope onto the casting support, the solvent starts to evaporate and the alcohol ratio increases and the web (dope film) gels, making the web strong and peeling from the casting support. Used as a gelling solvent to facilitate. Moreover, when these ratios are small, it also has a role of promoting the dissolution of the cellulose ester of the non-chlorine organic solvent.
[0100]
Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol and the like.
[0101]
Of these, ethanol is preferred because the dope has a relatively low boiling point, relatively low boiling point, good drying properties, and no toxicity. Preferably, a solvent containing 10 to 30% by mass of ethanol with respect to 70 to 90% by mass of methylene chloride is used. To avoid halogen-containing solvents due to environmental constraints, methyl acetate can be used instead of methylene chloride. In this case, a cellulose ester solution can be prepared using a cooling dissolution method in which the solution is cooled to −100 ° C. to −10 ° C. and dissolved.
[0102]
When a cellulose ester film is used for the base film of the antireflection film of the present invention, the cellulose ester film preferably contains a plasticizer. The plasticizer is not particularly limited, but is a phosphate ester plasticizer, a phthalate ester plasticizer, a trimellitic ester plasticizer, a pyromellitic acid plasticizer, a glycolate plasticizer, or a citrate ester plasticizer. An agent, a polyester plasticizer, or the like can be preferably used. For phosphate esters, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc.For phthalate esters, diethyl phthalate, dimethoxyethyl phthalate, dimethyl Trimellitic plasticizers such as phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, tributyl trimellitate, triphenyl trimellitate, triethyl trimellitate, pyromellitic Acid ester plasticizers include tetrabutyl pyromellitate, tetraphenyl pyromellitate, tetraethy In the case of glycolic acid esters such as pyromellitate, triacetin, tributyrin, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, etc., citrate plasticizers such as triethyl citrate, tri-n -Butyl citrate, acetyl triethyl citrate, acetyl tri-n-butyl citrate, acetyl tri-n- (2-ethylhexyl) citrate, or trimethylolpropane tribenzoate can be preferably used.
[0103]
Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.
[0104]
A copolymer of a dibasic acid such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid and a glycol can be used as the polyester plasticizer. The aliphatic dibasic acid is not particularly limited, and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyl dicarboxylic acid and the like can be used. As the glycol, ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol and the like can be used. These dibasic acids and glycols may be used alone or in combination of two or more.
[0105]
In particular, cellulose ester films having additives such as epoxy compounds, rosin compounds, phenol novolac type epoxy resins, cresol novolak type epoxy resins, ketone resins, toluenesulfonamide resins described in Japanese Patent Application No. 2000-338883 are preferably used. It is done. Specifically, examples of the rosin and the rosin derivative include the following structural formulas.
[0106]
[Chemical 1]

[0107]
Of the above compounds, KE-604 and KE-610 are commercially available from Arakawa Chemical Industries, Ltd. with acid values of 237 and 170, respectively. Similarly, KE-100 and KE-356 are commercially available from Arakawa Chemical Industries, Ltd. as an esterified product of a mixture of abietic acid, dehydroabietic acid, and parastrinic acid at 8 and 0, respectively. A mixture of abietic acid, dehydroabietic acid, and parastrinic acid is commercially available from Harima Kasei Co., Ltd. under G-7 and Hartle RX with acid values of 167 and 168, respectively.
[0108]
Examples of the epoxy resin used in the present invention include those having the following structures.
[0109]
[Chemical formula 2]

[0110]
Araldide EPN1179 and Araldide AER260 are commercially available from Asahi Ciba.
[0111]
Examples of the ketone resin used in the present invention include those having the following structure.
[0112]
[Chemical 3]

[0113]
As the high rack 110 and the high rack 110H, commercially available products from Hitachi Chemical Co., Ltd. are used. Examples of the paratoluenesulfonamide resin include those having the following structure, and are commercially available from Fujiamide Chemical Co., Ltd. as a topler.
[0114]
[Formula 4]

[0115]
These plasticizers are preferably used alone or in combination.
It is preferable that the usage-amount of these plasticizers is 1-20 mass% with respect to a cellulose ester at points, such as film performance and workability.
[0116]
The ultraviolet absorber according to the support used in the present invention will be described.
As the base material of the antireflection film of the present invention (in some cases, the support alone may be used), an ultraviolet absorber is preferably used from the viewpoint of preventing deterioration of liquid crystals and the like.
[0117]
As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having a small absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Specific examples of ultraviolet absorbers preferably used in the present invention include, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, triazine compounds, cyanoacrylate compounds, nickel complex compounds, and the like. For example, but not limited to. Further, a polymeric ultraviolet absorber described in JP-A-6-148430 is also preferably used.
[0118]
As the benzotriazole ultraviolet absorber, a compound represented by the following general formula [1] is preferably used.
[0119]
[Chemical formula 5]

[0120]
Where R₁, R₂, R_Three, R_FourAnd R_FiveMay be the same or different, and may be a hydrogen atom, halogen atom, nitro group, hydroxyl group, alkyl group, alkenyl group, aryl group, alkoxyl group, acyloxy group, aryloxy group, alkylthio group, arylthio group, mono- or dialkylamino group Represents an acylamino group or a 5- to 6-membered heterocyclic group, R_FourAnd R_FiveMay be closed to form a 5-6 membered carbocyclic ring. In addition, these groups described above may have an arbitrary substituent.
[0121]
Although the specific example of the ultraviolet absorber which concerns on this invention is given to the following, this invention is not limited to these.
[0122]
UV-1: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole
UV-2: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole
UV-3: 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole
UV-4: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole
UV-5: 2- (2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole
UV-6: 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol)
UV-7: 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole
UV-8: 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol (TINUVIN171, manufactured by Ciba)
UV-9: Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl- Mixture of 4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate (TINUVIN 109, manufactured by Ciba)
Among the above, as an ultraviolet absorber having a melting point of 20 ° C. or less, UV-8 is a melting liquid of −56 ° C., and UV-9 is a yellow transparent transparent liquid at ordinary temperature (25 ° C.).
[0123]
As the benzophenone-based ultraviolet absorber that is one of the ultraviolet absorbers according to the present invention, a compound represented by the following general formula [2] is preferably used.
[0124]
[Chemical 6]

[0125]
In the formula, Y represents a hydrogen atom, a halogen atom or an alkyl group, an alkenyl group, an alkoxyl group, and a phenyl group, and these alkyl group, alkenyl group, and phenyl group may have a substituent. A is a hydrogen atom, an alkyl group, an alkenyl group, a phenyl group, a cycloalkyl group, an alkylcarbonyl group, an alkylsulfonyl group, or —CO (NH)._n-1-D group is represented, D represents the alkyl group, the alkenyl group, or the phenyl group which may have a substituent. m and n represent 1 or 2.
[0126]
The alkyl group is, for example, a linear or branched aliphatic group having up to 24 carbon atoms, the alkoxyl group is, for example, an alkoxyl group having up to 18 carbon atoms, and the alkenyl group is, for example, alkenyl having up to 16 carbon atoms. The group represents, for example, an allyl group or 2-butenyl group. In addition, as substituents for alkyl groups, alkenyl groups, and phenyl groups, halogen atoms such as chlorine atoms, bromine atoms, fluorine atoms, hydroxyl groups, phenyl groups (this phenyl group includes alkyl groups or halogen atoms, etc.) And may be substituted).
[0127]
Specific examples of the benzophenone compound represented by the general formula [2] are shown below, but the present invention is not limited thereto.
[0128]
UV-10: 2,4-dihydroxybenzophenone
UV-11: 2,2'-dihydroxy-4-methoxybenzophenone
UV-12: 2-hydroxy-4-methoxy-5-sulfobenzophenone
UV-13: Bis (2-methoxy-4-hydroxy-5-benzoylphenylmethane)
The UV absorber preferably used in the present invention is preferably a benzotriazole-based UV absorber or a benzophenone-based UV absorber that has high transparency and is excellent in the effect of preventing the deterioration of the polarizing plate and the liquid crystal, and more unnecessary coloring. A small amount of benzotriazole ultraviolet absorber is particularly preferably used.
[0129]
In addition, the ultraviolet absorber contains an ultraviolet absorber having a distribution coefficient of 9.2 or more as described in Japanese Patent Application No. 11-295209, so that there is little contamination in the plasma treatment process, and the coating properties of various coating layers. In particular, it is preferable to use an ultraviolet absorber having a distribution coefficient of 10.1 or more.
[0130]
When cellulose ester films containing plasticizers or UV absorbers are used as the base material, they may bleed out, contaminating the process by adhering to the plasma processing part, etc. There was a cause. Therefore, as a result of intensive studies to solve this problem, the support has a cellulose ester and a plasticizer, and the mass change before and after the time treatment at 80 ° C. and 90% RH is less than ± 2% by mass. It was confirmed that such process contamination can be remarkably reduced if the body. As such a cellulose ester film, a cellulose ester film described in Japanese Patent Application No. 2000-338883 is preferably used. For this purpose, polymer ultraviolet absorbers (or ultraviolet absorbing polymers) described in JP-A-6-148430 and JP-A-2002-47357 can be preferably used. As a polymer ultraviolet absorber, PUVA-30M (manufactured by Otsuka Chemical Co., Ltd.) and the like are commercially available. The polymer ultraviolet absorbers described in general formula (1) or general formula (2) of JP-A-6-148430 or general formulas (3), (6) and (7) of JP-A-2002-47357 are particularly preferably used. .
[0131]
As the optical properties of the substrate according to the present invention, in-plane retardation R₀Is preferably used in a thickness of 0 to 1000 nm, and has a retardation R in the thickness direction._tIs preferably 0 to 300 nm depending on the application. As chromatic dispersion characteristics, R₀(600) / R₀(450) is preferably 0.7 to 1.3, more preferably 1.0 to 1.3.
[0132]
Where R₀(450) is an in-plane retardation based on three-dimensional refractive index measurement with light having a wavelength of 450 nm, R₀(600) represents in-plane retardation based on three-dimensional refractive index measurement with light having a wavelength of 600 nm.
[0133]
From the viewpoint of improving the adhesion between the substrate and the thin film formed by the plasma discharge treatment, the antireflection film of the present invention is formed on the layer formed by curing a component containing one or more ethylenically unsaturated monomers. It is preferable that the layer formed by curing the component containing the ethylenically unsaturated monomer is treated with a solution having a pH of 10 or more and then plasma-discharged. Further, it is preferable because the adhesion is further improved. As a solution having a pH of 10 or more, 0.1 to 3 mol / L sodium hydroxide or potassium hydroxide aqueous solution is preferably used. After being treated at 40 to 60 ° C. for 30 to 120 seconds, it is washed and dried. preferable.
[0134]
As the resin layer formed by polymerizing a component containing an ethylenically unsaturated monomer, a layer containing an actinic ray curable resin or a thermosetting resin as a constituent component is preferably used, but an actinic ray curable resin is particularly preferably used. Is a layer.
[0135]
Here, the actinic radiation curable resin layer refers to a layer mainly composed of a resin that cures through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, but a resin that is cured by irradiation with an actinic ray other than ultraviolet rays or an electron beam may be used. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. I can do it.
[0136]
UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) to products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. It can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate (for example, see JP-A-59-151110).
[0137]
The UV curable polyester acrylate resin can be easily obtained by reacting polyester polyol with 2-hydroxyethyl acrylate or 2-hydroxy acrylate monomer (see, for example, JP-A-59-151112). .
[0138]
Specific examples of the ultraviolet curable epoxy acrylate resin include those obtained by reacting epoxy acrylate with an oligomer, a reactive diluent and a photoinitiator added thereto (for example, JP-A-1- No. 105738). As the photoreaction initiator, one or more kinds selected from benzoin derivatives, oxime ketone derivatives, benzophenone derivatives, thioxanthone derivatives and the like can be selected and used.
[0139]
Specific examples of ultraviolet curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate. Etc. can be mentioned.
[0140]
These resins are usually used together with known photosensitizers. The above photoreaction initiator can also be used as a photosensitizer. Specific examples include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and the like. In addition, when using an epoxy acrylate photoreactant, a sensitizer such as n-butylamine, triethylamine, tri-n-butylphosphine can be used. It is preferable that the photoreaction initiator or photosensitizer contained in the ultraviolet curable resin composition excluding the solvent component that volatilizes after coating and drying is 2.5 to 6% by mass of the composition.
[0141]
Examples of the resin monomer include general monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, vinyl acetate, benzyl acrylate, cyclohexyl acrylate, and styrene as monomers having one unsaturated double bond. In addition, as monomers having two or more unsaturated double bonds, ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, the above-mentioned trimethylolpropane Examples thereof include triacrylate and pentaerythritol tetraacryl ester.
[0142]
For example, as an ultraviolet curable resin, Adeka optomer KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (manufactured by Asahi Denka Kogyo Co., Ltd.) Or Koeihard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS-101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Industry Co., Ltd.), or Seika Beam PHC2210 (S), PHC X-9 (K-3), PHC2213, DP -10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (above, (Manufactured by Nissei Kagaku Co., Ltd.), or KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (above, Daicel UCB), or RC-5015, RC-5016, RC-5020, RC-5031, RC- 5100, RC-5102, RC-5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by Dainippon Ink & Chemicals, Inc.) or Aulex No. 340 clear (manufactured by China Paint Co., Ltd.), Sunrad H-601 (manufactured by Sanyo Chemical Industries, Ltd.), SP-1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.), or RCC-15C (Grace Japan Co., Ltd.) (Manufactured by company), Aronix M-6100, M-8030, M-8060 (above, manufactured by Toagosei Co., Ltd.) or other commercially available ones can be used.
[0143]
The actinic radiation curable resin layer used in the present invention can be applied by a known method. As the light source for forming the coating layer by curing the actinic radiation curable resin by a photocuring reaction, any light source that generates ultraviolet rays can be used. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Irradiation conditions vary depending on each lamp, but the amount of irradiation light is 20-10000 mJ / cm.²Any degree is preferable, preferably 50 to 2000 mJ / cm.²It is. It can be used by using a sensitizer having an absorption maximum in the near ultraviolet region to the visible light region.
[0144]
Solvents for coating the above-mentioned back coat layer or resin layer containing conductive fine particles as a solvent for coating an actinic radiation curable resin layer, such as hydrocarbons, alcohols, ketones, esters, glycol ethers It is possible to appropriately select from among other solvents or to use them by mixing them. Preferably, propylene glycol mono (alkyl group having 1 to 4 carbon atoms) alkyl ether or propylene glycol mono (alkyl group having 1 to 4 carbon atoms) alkyl ether ester is 5% by mass or more, more preferably 5 to 80% by mass or more. The containing solvent is used.
[0145]
As a method for applying the ultraviolet curable resin composition coating solution, a known method such as a gravure coater, a spinner coater, a wire bar coater, a roll coater, a reverse coater, an extrusion coater, or an air doctor coater can be used. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm in terms of wet film thickness. The coating speed is preferably 10 to 60 m / min.
[0146]
The UV curable resin composition is applied and dried, and then irradiated with UV light from a light source. The irradiation time is preferably 0.5 seconds to 5 minutes, and 3 seconds to 2 from the curing efficiency and work efficiency of the UV curable resin. Minutes are more preferred.
[0147]
It is preferable to add inorganic or organic fine particles to the cured film layer thus obtained in order to prevent blocking and to improve scratch resistance. Examples of inorganic fine particles include silicon oxide, titanium oxide, aluminum oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, calcium sulfate, and the like, and examples of organic fine particles include polymethacrylic acid. Methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin resin powder, polyester resin powder , Polyamide resin powder, polyimide resin powder, polyfluoroethylene resin powder, and the like, and can be added to the ultraviolet curable resin composition. The average particle diameter of these fine particle powders is preferably 0.005 μm to 1 μm, and particularly preferably 0.01 to 0.1 μm.
[0148]
As for the ratio of a ultraviolet curable resin composition and fine particle powder, it is desirable to mix | blend so that it may be 0.1-10 mass parts with respect to 100 mass parts of resin compositions. A layer obtained by curing an ultraviolet curable resin (ultraviolet curable resin layer) may be formed by laminating two or more layers.
[0149]
The ultraviolet curable resin layer thus formed may be a clear hard coat layer with a centerline surface roughness Ra of 1 to 50 nm or an antiglare layer with an Ra of about 0.1 to 1 μm. . These ultraviolet curable resin layers have a pencil hardness of 2H or more, preferably 4H to 6H. Further, the residual solvent of these ultraviolet curable resin layers is preferably 0 to less than 3%, preferably 0 to less than 1%, particularly preferably 0 to less than 0.1%. Is desirable.
[0150]
In the present invention, plasma discharge treatment can be performed on these layers. In particular, according to the method of the present invention, a uniform optical interference layer such as a low refractive index layer or a high refractive index layer can be provided on a substrate having an uneven surface. In particular, it is preferable because a plasma discharge treatment can be uniformly performed on an antiglare layer having a center line average roughness (Ra) defined by JIS B 0601 of 0.1 to 0.5 μm.
[0151]
In the present invention, when a thin film is provided on the base material surface as described above, it is preferable to provide the film thickness deviation with respect to the average film thickness to be ± 10%, more preferably within ± 5%, It is particularly preferable to provide it within ± 1%.
[0152]
When producing the antireflection film of the present invention, it is preferable to irradiate the plasma discharge treatment surface with ultraviolet rays before the plasma discharge treatment because the adhesion of the formed film is excellent. The amount of UV irradiation is 50 to 2000 mJ / cm²It is preferable that 50 mJ / cm²Less than 2000mJ / cm, the effect is not sufficient.²Exceeding the range is not preferred because the substrate may be deformed. Plasma discharge treatment is preferably performed within 1 hour after ultraviolet irradiation, and plasma discharge treatment is particularly preferable within 10 minutes after ultraviolet irradiation. The ultraviolet irradiation before the plasma discharge treatment may be performed simultaneously with the ultraviolet irradiation for curing the above-described ultraviolet curable resin, and in that case, it may be more than the minimum necessary ultraviolet irradiation amount for curing. preferable.
[0153]
When producing the antireflection film of the present invention, it is also effective to stabilize the formed film at an early stage by irradiating with ultraviolet rays after performing the plasma discharge treatment. For this reason, 50-2000 mJ / cm as the amount of ultraviolet irradiation light²Is preferably irradiated to the plasma discharge treatment surface after the plasma discharge treatment. These treatments are preferably performed after the plasma discharge treatment and before the winding process. Moreover, it is preferable that the base material after a plasma discharge process is processed for 1 to 30 minutes in the heat processing zone adjusted to 50-130 degreeC.
[0154]
The antireflection film is preferably subjected to plasma discharge treatment on both sides because curling of the antireflection film after treatment is reduced. Although the plasma discharge treatment on the back surface may be performed separately, it is preferable to perform the plasma discharge treatment on both surfaces simultaneously, and it is preferable to perform the back surface processing by the plasma discharge treatment on the back surface side of the surface having the antireflection layer. For example, easy adhesion processing described in Japanese Patent Application No. 2000-273066 and antistatic processing described in Japanese Patent Application Laid-Open No. 2001-337201 can be mentioned, but the invention is not particularly limited thereto.
[0155]
In the present invention, it is preferable to continuously provide a high refractive index layer having a refractive index of 1.6 to 2.3 and a low refractive index layer having a refractive index of 1.3 to 1.5 on the surface of a long substrate. Thereby, the adhesiveness between each layer becomes favorable. Preferably, it is more preferable to provide a high refractive index layer and a low refractive index layer by plasma discharge treatment immediately after the ultraviolet curable resin layer is provided on the base film.
[0156]
In the antireflection film of the present invention, two or more high refractive index layers and low refractive index layers can be alternately laminated to obtain an antireflection film having a lower reflectance. Moreover, it is preferable for the carbon content of each layer to be 0.1 to 20% because of excellent adhesion to the lower layer and flexibility of the film. That is, since the layer formed by the plasma discharge treatment contains an organic substance (carbon atom), the range gives flexibility to the film, which is excellent in film adhesion. If the carbon ratio is too large, the refractive index tends to fluctuate with time, which is not preferable.
[0157]
In the antireflection film having a low refractive index layer having a refractive index of 1.3 to 1.5, the low refractive index layer has a region having a carbon content of less than 5% on the base film side, and the low refractive index region It is preferable to have a region having a carbon content of 5 to 60% on the upper surface side. In the antireflection film having a high refractive index layer having a refractive index of 1.6 to 2.3, the carbon content of the high refractive index layer is preferably 0.1 to 20%.
[0158]
The antireflection film of the present invention is preferably used for various display devices such as a liquid crystal display, an organic EL display, and a plasma display.
[0159]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these. In addition, the following "part" represents a "mass part".
[0160]
Example 1
<< Preparation of base film >>
According to the method shown below, a cellulose ester film as a substrate was produced.
(Preparation of dope)
The materials described below were put into a sealed container, and completely dissolved and filtered while heating and stirring to prepare Dopes 1 to 3. Silicon dioxide fine particles (Aerosil R972V) were added after being dispersed in ethanol. The average particle size of the secondary particles was 0.2 μm.
Dope 1
100 parts of cellulose triacetate (acetyl substitution degree 2.88)
6 parts trimethylolpropane tribenzoate
Ethyl phthalyl ethyl glycolate 6 parts
2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl)
) -4-methylphenol 0.5 part
5-chloro-2- (3,5-disec-butyl-2-hydroxyphenyl)
-2H-benzotriazole 0.5 part
418 parts of methylene chloride
23 parts of ethanol
Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) 0.13 parts
Dope 2
100 parts of cellulose acetate propionate
(Acetyl substitution degree 1.9 propionyl substitution degree 0.8)
6 parts trimethylolpropane tribenzoate
Ethyl phthalyl ethyl glycolate 6 parts
2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl)
) -4-methylphenol 0.5 part
5-chloro-2- (3,5-disec-butyl-2-hydroxyphenyl)
-2H-benzotriazole 0.5 part
400 parts of methyl acetate
50 parts of ethanol
Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) 0.13 parts
Dope 3
100 parts of cellulose triacetate (acetyl substitution degree 2.88)
12 parts of triphenyl phosphate
2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl)
) -4-methylphenol 0.5 part
5-chloro-2- (3,5-disec-butyl-2-hydroxyphenyl)
-2H-benzotriazole 0.5 part
418 parts of methylene chloride
23 parts of ethanol
Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) 0.13 parts
(Production of cellulose ester film)
Using the obtained dope 1, a cellulose ester film 1 having a film thickness of 40 μm and a cellulose ester film 2 having a film thickness of 60 μm were produced as follows. Similarly, the dope 2 was used to produce a cellulose ester film 3 having a film thickness of 40 μm and a cellulose ester film 4 having a film thickness of 80 μm as follows. Similarly, using the dope 3, a cellulose ester film 5 having a film thickness of 40 μm and a cellulose ester film 6 having a film thickness of 60 μm were prepared as follows.
[0161]
After the dope was filtered, it was cast uniformly on a stainless steel band support at a dope temperature of 36 ° C. using a belt casting apparatus. After drying on the support while applying hot air, the web was peeled off from the stainless band support.
[0162]
After peeling from the stainless steel band support, it was rolled in a 70 ° C. atmosphere and dried while applying conveying tension in the vertical direction, and then in the width direction in the 80 ° C. atmosphere when the residual solvent amount was 10% with a tenter. Direction), release the width grip, finish drying in a 125 ° C drying zone while carrying the roll, and apply a knurling process with a width of 10 mm and a height of 8 μm on both ends of the film. 1-6 were produced. The film width was 1300 mm and the winding length was 2000 m.
[0163]
Next, the base films 1-24 which provided each application layer as shown in Table 1 with the following method were produced. Here, at the time of casting film formation, the film surface on the side where the casting film is in contact with the stainless steel band support is defined as B surface, and the opposite surface is defined as A surface.
<Coating of antistatic layer (ANS layer)>
About the said base film 13-16, the following coating composition (1) was extrusion-coated on the B surface so that it might become a wet film thickness of 13 micrometers, and it dried at the drying temperature of 90 degreeC, and applied the antistatic layer. .
・ Coating composition (1) (coating composition for antistatic layer)
Acrypet MD (Mitsubishi Rayon Co., Ltd.) 0.5 part
60 parts of propylene glycol monomethyl ether
16 parts of methyl ethyl ketone
5 parts of ethyl lactate
8 parts of methanol
Conductive polymer resin P-1 (average particle size 0.1 μm particles) 0.5 part
[0164]
[Chemical 7]

[0165]
<< Coating of back coat layer (BC layer) >>
The following coating composition (2) was extrusion coated on the A side of the cellulose ester film so as to have a wet film thickness of 15 μm, dried at a drying temperature of 80 ° C., and a backcoat layer was applied.
-Coating composition (2) (backcoat layer coating composition)
30 parts of acetone
45 parts of ethyl acetate
10 parts isopropyl alcohol
Diacetylcellulose 0.5 part
Ultrafine silica 2% acetone dispersion (Aerosil 200V: Nippon Aerosil
0.1 part)
<Coating of clear hard coat layer>
-CHC1 layer-
The following coating composition (3) was gravure coated and then dried in a drying section set at 80 ° C., and then 120 mJ / cm²And a clear hard coat layer (CHC1 layer) having a dry film thickness of 3 μm and a center line average roughness (Ra) of 0.01 μm was provided. Here, the center line average roughness (Ra) is a value defined by JIS B 0601.
・ Coating composition (3) (Clear hard coat layer coating composition)
100 parts of UV curable acrylic urethane resin
(Unidic 17-806 (Dainippon Ink Co., Ltd.) 99 parts, Coronate L (polyisocyanate compound: Nippon Polyurethane Co., Ltd.) 1 part)
Photopolymerization initiator (Irgacure 184, manufactured by Ciba Geigy) 3 parts
Were mixed by a homogenizer with a solvent (ethyl acetate) to prepare a homogeneous coating solution having a volatile concentration of 60%.
-CHC2 layer-
The following coating composition (4) was gravure coated and then dried in a drying section set at 80 ° C., and then 118 mJ / cm²And a clear hard coat layer (CHC2 layer) having a dry film thickness of 3 μm and a center line average roughness (Ra) of 0.01 μm was provided. Here, the center line average roughness (Ra) is a value defined by JIS B 0601.
・ Coating composition (4) (Clear hard coat layer coating composition)
60 parts of dipentaerythritol hexaacrylate monomer
Dipentaerythritol hexaacrylate dimer 20 parts
Dipentaerythritol hexaacrylate trimer or higher component 20 parts
Dimethoxybenzophenone photoinitiator 4 parts
50 parts of ethyl acetate
50 parts of methyl ethyl ketone
Isopropyl alcohol 50 parts
《Coating of antiglare layer》
-AG1 layer-
The following coating composition (5) was gravure coated and then dried in a drying section set at 80 ° C., and then 118 mJ / cm²And an antiglare layer (AG1 layer) having a dry film thickness of 3 μm was provided. The center line average roughness (Ra) was 0.2 μm. Here, the center line average roughness (Ra) is a value defined by JIS B 0601.
・ Coating composition (5) (AG1 layer coating composition)
10 parts of synthetic silica fine particles (average particle size 0.5 μm)
Synthetic silica fine particles (average particle size 1.4μm) 10 parts
100 parts of UV curable acrylic urethane resin
(Unidic 17-806 (Dainippon Ink Co., Ltd.) 99 parts, Coronate L (polyisocyanate compound: Nippon Polyurethane Co., Ltd.) 1 part)
Photopolymerization initiator (Irgacure 184, manufactured by Ciba Geigy) 3 parts
Were mixed with a solvent (ethyl acetate) by a homogenizer to prepare a homogeneous dispersion having a volatile concentration of 60%.
-AG2 layer-
The following coating composition (6) was gravure coated and then dried in a drying section set at 80 ° C., and then 118 mJ / cm²And an antiglare layer (AG2 layer) having a dry film thickness of 3 μm was provided. The center line average roughness (Ra) was 0.2 μm. Here, the center line average roughness (Ra) is a value defined by JIS B 0601.
・ Coating composition (6) (AG two-layer coating composition)
50 parts of ethyl acetate
50 parts of methyl ethyl ketone
Isopropyl alcohol 50 parts
Aerosil R972V (Average primary particle size 16nm)
(Nippon Aerosil Co., Ltd.) 5 parts
The above is stirred with a high-speed stirrer (TK homomixer, manufactured by Tokushu Kika Kogyo Co., Ltd.) and then dispersed with a collision type disperser (manton gourin, manufactured by Gorin Co., Ltd.). Composition (6) was prepared.
[0166]
60 parts of dipentaerythritol hexaacrylate monomer
Dipentaerythritol hexaacrylate dimer 20 parts
Dipentaerythritol hexaacrylate trimer or higher component 20 parts
Dimethoxybenzophenone photoinitiator 4 parts
[0167]
[Table 1]

[0168]
<Formation of antireflection layer by atmospheric pressure plasma discharge treatment>
A medium refractive index layer and a high refractive index layer were sequentially provided on the clear hard coat layer or the antiglare layer of the prepared base film by the atmospheric pressure plasma discharge treatment of FIG. As the roll electrode, a stainless steel jacket roll base material having a temperature adjustment function using silicon oil (the temperature adjustment function is not shown in FIG. 2) was used. This was coated with 1 mm of alumina by ceramic spraying, and a solution of tetramethoxysilane diluted with ethyl acetate was applied and dried on it, cured by ultraviolet irradiation, sealed, and a roll electrode having a dielectric of Rmax 3 μm was produced. And grounded. On the other hand, the counter electrode is made of titanium, provided with a circulation path for the medium for adjusting the temperature, covered with the same dielectric material under the same conditions, and used as an opposing electrode group. Was adjusted for the middle refractive index layer, the second for the high refractive index layer, and the third for the low refractive index layer so that the required film thicknesses were obtained. Moreover, the power source of the first, second and third plasma discharge treatment apparatuses uses a high frequency power source (manufactured by Pearl Industry), the continuous frequency is 2 MHz, and 3 W / cm.²Power was supplied. The roll electrode was rotated in synchronization with the conveyance of the base film using a drive. The electrode gap was 1.2 mm, and the reaction gas pressure was atmospheric pressure + 1 kPa. The composition of the reaction gas used for the plasma discharge treatment is described below. The liquid reaction gas component was vaporized using a vaporizer, mixed with an inert gas, and introduced into the plasma discharge treatment apparatus. Each reaction gas was supplied to the discharge section at 80 ° C.
(Reactive gas for forming tin oxide layer (medium refractive index layer))
Inert gas (helium) 99.4% by volume
Reaction gas (oxygen gas) 0.3% by volume
Reaction gas (tetrabutyltin vapor) 0.3% by volume
(Reaction gas for forming titanium oxide layer (high refractive index layer))
Inert gas (helium) 99.4% by volume
Reaction gas (oxygen gas) 0.3% by volume
Reaction gas (tetraisopropoxytitanium vapor) 0.3% by volume
Continuously processed by atmospheric pressure plasma, a tin oxide layer (refractive index 1.7, film thickness 76 nm) and a titanium oxide layer (refractive index 2.14, film thickness 112 nm) were formed in this order.
[0169]
Further, a silicon oxide layer (refractive index: 1.46, film thickness: 87 nm) as a low refractive index layer is provided using the following reaction gas, and optical films 1 to 40 described in Tables 2 and 3 below are provided. Produced. The low refractive index layer is formed by changing the gas condition from 1 to 3 on the way, first formed by treatment under the gas condition A, and then formed by treatment under the gas condition B. It was set to 87 nm. The low refractive index layer formed under each gas condition was obtained for the content of each element using an XPS apparatus, and the carbon content was obtained according to the following formula.
・ Gas condition 1
Tetraethoxysilane 0.3%
Helium 99.5%
Oxygen 0.2%
Carbon content (in silicon oxide layer) 0.2%
・ Gas condition 2
Tetraethoxysilane 0.15%
Methyltriethoxysilane 0.15%
Helium 99.5%
Oxygen 0.2%
Carbon content (in silicon oxide layer) 10%
・ Gas condition 3
Tetraethoxysilane 0.2%
Methyltriethoxysilane 0.1%
Helium 99.6%
Tetrafluoromethane 0.1%
Carbon content (in silicon oxide layer) 7%
<Measurement of element content>
The values of carbon, silicon, oxygen and fluorine in the low refractive index region are measured using an XPS apparatus. There is no particular limitation on the XPS apparatus, and any model can be used. In the present invention, ESCALAB 200R manufactured by VG Scientific Fix Inc. was used. Mg was used for the X-ray anode, and measurement was performed at an output of 600 W (acceleration voltage: 15 kV, emission current: 40 mA). The energy resolution was set to be 1.5 to 1.7 eV when defined by the half width of a clean Ag3d5 / 2 peak. Before measuring the low refractive index region, it is necessary to etch away the surface layer corresponding to a thickness of 5 to 10% of the thickness of the thin film in order to eliminate the influence of contamination. For removing the surface layer, an ion gun that can use rare gas ions can be used, and ion species such as He, Ne, Ar, Xe, and Kr can be used.
[0170]
Further, changes in the carbon, silicon, and oxygen contents in the depth direction of the film were also determined by etching with rare gas ions. In this measurement, etching was performed at 1 minute intervals using Ar ions with an acceleration voltage of 3 kV, and the element content on the film surface was measured. In the content measurement, the range of binding energy from 0 eV to 1100 eV was measured at a data acquisition interval of 1.0 eV to determine what elements were detected. Next, with respect to all the detected elements except for the etching ion species, the data capture interval was set to 0.2 eV, and the photoelectron peak giving the maximum intensity was subjected to narrow scan, and the spectrum of each element was measured.
[0171]
The obtained spectrum is transferred to COMMON DATA PROCESSING SYSTEM (Ver. 2.3) manufactured by VAMAS SCA JAPAN in order to prevent the difference in the content calculation result due to the difference in the measuring apparatus or the computer. Processing was carried out with the same software, and the content of the detected element was determined as atomic concentration. Before performing the quantification process, calibration of the count scale was performed for each element, and a 5-point smoothing process was performed. In the quantitative process, the peak area intensity (cps × eV) from which the background was removed was used. For the background treatment, the method by Shirley was used. For the Shirley method, see D.C. A. Shirley, Phys. Rev. B5, 4709 (1972).
[0172]
In the present invention, the average content of each element in the low refractive index layer is the average of the element contents at each analysis point obtained as a result of the depth direction analysis. Here, the carbon content was determined by the following equation.
[0173]
Carbon content% = carbon content / (carbon content + silicon content + oxygen content) × 100
<Evaluation>
The following evaluation was performed about the obtained optical films 1-40.
(Winding shape)
After wrapping the optical film with a polyethylene sheet to prevent dust adhesion, store it in a warehouse at 42 ° C and 80% RH for 1 month, visually observe the winding state after 1 month, and evaluate the rank as follows: did.
[0174]
A: No changes such as wrinkles or deformation are observed on the surface of the roll.
B: Slight wrinkles are observed on the surface of the roll, but no deformation is observed
C: Weak wrinkles are observed on the roll surface, and some deformation is also observed.
D: Strong crease on the surface of the roll to the inside, strong deformation on the surface, deformation to the inside
The practicality judgment about the above rank is as follows.
[0175]
A: Can be used without excision
B ... Can be used after excising several meters
C: Can be used by cutting several turns (several meters to several tens of meters) from the surface
D ... Unable to use until the inner part (several tens of meters) is excised until no deformation of the winding is recognized.
(curl)
The produced roll film was stored for 1 month in an atmosphere of 42 ° C. and 80% RH, cut out into a size of 10 cm × 10 cm, and the antireflection layer forming surface was faced up in an environment of 23 ° C. and 55% RH. Placed on a flat glass, the height of the lifted edge was measured.
[0176]
A ... The height of the lifted edge is less than 5mm
B ... Lifting height of the end is less than 5-10mm
C ... Height of lifting at the end is less than 10-15mm
D ... The height of the lifted edge is 15mm or more
(Preparation of polarizing plate)
The produced roll film is stored for one month in an atmosphere of 42 ° C. and 80% RH, and the film is used as a polarizing plate protective film on the front surface side. A cellulose ester film (before providing each coating layer and antireflection layer) used in the film was used as a polarizing plate.
1. Production of polarizing film
A long polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. . This was washed with water and dried to obtain a long polarizing film.
2. Production of polarizing plate
Subsequently, according to the following processes 1-5, the polarizing film and the optical film were bonded together and the polarizing plate was produced.
[0177]
Step 1: The long optical film produced as described above was immersed in a 2 mol / L sodium hydroxide solution at 45 ° C. for 50 seconds, then washed with water and dried.
[0178]
Similarly, a long cellulose ester film (used as a substrate for an optical film) was immersed in a 2 mol / L sodium hydroxide solution at 45 ° C. for 50 seconds, then washed with water and dried.
[0179]
Process 2: The above-mentioned long polarizing film was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.
[0180]
Step 3: Excess adhesive adhered to the polarizing film in Step 2 was lightly removed, and it was sandwiched between the optical film and the cellulose ester film that had been subjected to alkali treatment in Step 1 and laminated.
[0181]
Process 4: 20-30 N / cm with two rotating rollers²Bonding was performed at a pressure of about 2 m / min. At this time, care was taken to prevent bubbles from entering.
[0182]
Step 5: The sample prepared in Step 4 was dried for 2 minutes in a dryer at 80 ° C. to prepare the polarizing plate 1 of the present invention.
[0183]
Subsequently, in preparation of the polarizing plate 1, it replaced with the optical film 1, and similarly produced the polarizing plates 2-40 similarly except having used the optical films 2-40 similarly. 10m²Confirmed the failure.
[0184]
A: No failure or defect due to bubbles, wrinkles, etc.
B: Less than 2 failures / defects due to bubbles, wrinkles, etc.
C: Less than 3-10 failures / defects due to bubbles, wrinkles, etc.
D: 10 or more failures / defects due to bubbles, wrinkles, etc.
This is a comparative example of polarizing plates 1 to 34 of the present invention in which the polarizing plate on the outermost surface of a commercially available liquid crystal display panel (NEC color liquid crystal display MultiSync LCD1525J type name LA-1529HM) is carefully peeled off and the polarization direction is adjusted here. Polarizers 35 to 40 were attached. Each liquid crystal display panel was visually observed.
<Measurement of reflectance>
The reflectance was measured using a spectrophotometer U-4000 type (manufactured by Hitachi, Ltd.) under the condition of regular reflection at 5 degrees. Measurement is performed by roughening the back side of the observation side and then performing light absorption using a black spray to prevent reflection of light on the back side of the film and measuring reflectance (for wavelengths of 400 to 700 nm). Went. An average reflectance of 450 to 650 nm was determined.
[0185]
[Table 2]

[0186]
[Table 3]

[0187]
As is clear from Tables 2 and 3, it was confirmed that the optical film of the present invention has few curls, is particularly excellent in storability in a wound shape, and is less likely to cause defects and failures in the production of polarizing plates. On the other hand, it was confirmed that the optical film of the comparative example was curled, inferior in storability in a wound shape, and easily caused defects in the production of the polarizing plate. In particular, it was confirmed that those using an acrylic urethane-based resin for the clear hard coat layer and the antiglare layer have less curl and further have fewer defects in the production of the polarizing plate.
[0188]
Moreover, it was confirmed that the liquid crystal display panel using the polarizing plate of the present invention has little reflected light and is excellent in display performance. In addition, the polarizing plates 1 to 34 could be easily wiped off with a cloth even when fingerprints were attached, and in particular, the polarizing plates 17 to 34 could be easily wiped off. Also, it was not damaged even when rubbed with a cloth.
[0189]
Example 2
On the clear hard coat layer of the base film 1 produced in Example 1, a first titanium oxide layer (refractive index 2.15, average film thickness 15 nm) and first silicon oxide layer (refractive index 1. 46, average film thickness 33 nm), and a second titanium oxide layer (refractive index 2.15, average film thickness 119 nm) were formed in this order. The base film 17 was formed in the same manner instead of the base film 1.
[0190]
The same plasma discharge processing apparatus as in Example 1 was used, the power source was a high frequency power source (manufactured by JEOL Ltd.), the continuous frequency was 13.56 MHz, and 3 W / cm.²Power was supplied. The roll electrode was rotated in synchronization with the conveyance of the base film using a drive. The electrode gap was 1.4 mm, and the reaction gas pressure was atmospheric pressure + 2 kPa. The composition of the reaction gas used for the plasma discharge treatment is described below.
(Reactive gas for forming first and second titanium oxide layers (high refractive index layers))
Inert gas (helium) 99.6% by volume
Reaction gas (hydrogen gas) 0.2% by volume
Reaction gas (tetraisopropoxytitanium vapor) 0.2% by volume
(Reaction gas for forming the first silicon oxide layer (low refractive index layer))
Inert gas (helium) 99.6% by volume
Reaction gas (oxygen gas) 0.2% by volume
Reaction gas (tetraethoxysilane vapor) 0.2% by volume
On this second titanium oxide layer, the gas conditions shown in Table 4 below are adopted as the low refractive index layer, and the second silicon oxide layer (refractive index 1.46, average film thickness 86 nm) is used as the low refractive index region on the surface. Was provided. The gas conditions shown in Table 4 are expressed as gas conditions A and B shown in Table 5 below.
[0191]
[Table 4]

[0192]
After forming a layer having a predetermined film thickness under gas condition A as shown in Table 5, a layer having a predetermined film thickness was subsequently formed under gas condition B. A polarizing plate was produced and evaluated in the same manner as in Example 1 using the obtained antireflection film.
[0193]
[Table 5]

[0194]
* 1: Plasma discharge treatment was performed on the surface of the base film 54 under the gas condition 14.
* 2: Plasma discharge treatment was performed on the surface of the base film 46 under the gas condition 13
As is clear from Table 5, it was confirmed that the optical film of the present invention has few curls, is particularly excellent in storability in a wound shape, and has few defects and failures in the production of polarizing plates. On the other hand, it was confirmed that the optical film of the comparative example was curled, inferior in storability in a wound shape, and easily caused defects in the production of the polarizing plate.
[0195]
【The invention's effect】
According to the present invention, it is possible to obtain an antireflection film that has excellent storage stability, has little curling, and has few dents and bubbles when producing a polarizing plate, and finds a method that can produce it with high productivity. Can be achieved, and the effect is remarkably excellent. Further, the polarizing plate and the display device incorporating the antireflection film have improved failures and defects due to bubbles, wrinkles and the like.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a plasma discharge treatment apparatus.
FIG. 2 is a diagram showing an example of a plasma discharge treatment apparatus having a rotating electrode and a fixed electrode.
[Explanation of symbols]
F Cellulose ester film
G reaction gas
G 'exhaust gas
10A, 10B, 110 Rotating electrode
11A, 11B, 11C, 11D U-turn roll
20, 21 Guide roll
30 Reaction gas supply unit
40, 140 Gas exhaust port
50, 150 Discharge section
80, 180 power supply
81, 82, 181, 182 Voltage supply means
111 Fixed electrode
120, 121 Guide roll
122, 123 Nip roll
124, 125 divider
130 Air supply pipe
131 Reaction gas generator
190 Plasma discharge treatment vessel

Claims (3)

In the method for producing an antireflection film in which an antireflection layer having at least one high refractive index region and at least one low refractive index region thereon is formed on a base film, the following general formulas (1) to (1) (4) A method for producing an antireflection film in which a low refractive index region is formed by plasma discharge treatment under a pressure of 20 to 200 kPa of a reaction gas containing a compound represented by (4), wherein the low refractive index region on the surface is refracted. The ratio is 1.3 to 1.5, contains silicon, has a region where the carbon content increases stepwise or continuously toward the surface, and the film thickness on the base film side of the low refractive index region Any one of the compounds represented by the following general formulas (2) to (4) when the surface layer of the low refractive index region is formed using the compound represented by the following general formula (1) mainly for at least half of Or one of these and the following general Method for producing an antireflection film, which comprises using a mixture of the compound represented by (1).
General formula (1) Si (OR ₁ ) (OR ₂ ) (OR ₃ ) (OR ₄ )
General formula (2) R ₁₁ Si (OR ₁ ) (OR ₂ ) (OR ₃ )
Formula (3) R ₁₁ R ₁₂ Si (OR ₁ ) (OR ₂ )
Formula (4) R ₁₁ R ₁₂ R ₁₃ Si (OR ₁ )
—OR ₁ to —OR ₄ are each an optionally substituted alkoxy group, and R _{11 to} R ₁₃ are selected from an optionally substituted alkyl group, alkenyl group, hydrogen atom, and halogen atom. It is a substituent and may be different or the same. The method for producing an antireflection film according to claim 1, wherein a fluorine compound is contained in the reaction gas when the surface layer of the low refractive index region is formed. The manufacturing method of the polarizing plate which has an antireflection film WHEREIN: The manufacturing method of the antireflection film of Claim 1 or 2 is used, The manufacturing method of the polarizing plate characterized by the above-mentioned.

Images