JP2004004176A - Antireflection resin sheet, substrate for image display, image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection resin sheet, forming a thin and lightweight liquid crystal cell substrate with durability and a substrate or the like for an image display, such as a substrate an organic EL display having a glare shield function preventing the so-called ghost phenomenon imaging external environment of illuminating light, such as fluorescent light and sunlight and a key boarder on a screen and a light diffusion function which prevents glare caused by the illuminating light and a liquid crystal display built-in backlight, and to provide a liquid crystal display using it and the image display, such as the organic EL display. <P>SOLUTION: The antireflection resin sheet has a base material layer, a gas barrier layer and a hard coat layer having an uneven structure on an outside surface laminated in this order, and forms a low refractive index layer, comprising a material with a lower refractive index than that of the hard coat layer forming resin on the hard coat. The antireflection resin sheet contains transparent particles in the hard coat layer having the uneven structure. <P>COPYRIGHT: (C)2004,JPO

Description

【００３８】
本発明においては、ハードコート層が表面凹凸構造を有することにより防眩機能が付与され、該ハードコート層に透明粒子を含有させることにより光拡散機能が付与され、さらに表面に凹凸構造を有するハードコート層表面を低屈折率層で覆うことにより、これらの相乗効果によって、それぞれ単独の場合よりも優れた防眩機能と光拡散機能と反射防止機能が発揮されると考えられる。
【００３９】
本発明において、凹凸構造を有するハードコート層の表面粗さ（Ｒａ）は８０ｎｍ〜５００ｎｍであることが好ましく、さらに好ましくは１００ｎｍ〜４００ｎｍであるのが良い。凹凸構造を有するハードコート層の表面粗さ（Ｒａ）が８０ｎｍよりも小さい場合や５００ｎｍよりも大きい場合は、十分な防眩機能を付与することができない。なお、本発明における表面粗さはＪＩＳ　Ｂ　０６０１に記載の「算術平均粗さＲａ」のことである。
【００４０】
また前記の表面凹凸構造を有するハードコート層の山谷間隔は、２０μｍ〜８０μｍであることが好ましく、さらに好ましくは３０μｍ〜７０μｍであるのが良い。山谷間隔が２０μｍよりも小さい場合や８０μｍよりも大きい場合は、十分な防眩機能を付与することができない。なお本発明における山谷間隔はＪＩＳ
Ｂ　０６０１に記載の「凹凸の平均間隔Ｓｍ」のことである。
【００４１】
前記の透明粒子としては、ガラスやシリカ等の無機材料、アクリル系樹脂、ポリエステル系樹脂、エポキシ系樹脂、メラミン系樹脂、ウレタン系樹脂、ポリカーボネート系樹脂、ポリスチレン系樹脂、シリコーン系樹脂、ベンゾグアナミン、メラミン・ベンゾグアナミン縮合物やベンゾグアナミン・ホルムアルデヒド縮合物等の有機材料が挙げられ、より好ましくはハードコート層を形成する樹脂との屈折率差が０．０３〜０．１０の範囲である球形粒子がよい。前記屈折率差が０．０３よりも小さい場合や０．１０より大きい場合は十分な光拡散機能を付与することができない。
【００４２】
透明粒子は、その粒子径が実質的に０．３μｍ〜３０μｍの範囲にあるのが好ましい。粒子径が０．３μｍ以上あれば光の拡散性が良好となり、３０μｍ以下であれば光の拡散性が均一となる。
【００４３】
透明粒子のハードコート層に対する体積比率は１〜５０％であることが好ましい。体積比率は（透明粒子の体積／ハードコート層の体積）×１００で算出することができる。ここでのハードコート層の体積とは透明粒子を含んだハードコート層の体積のことである。透明粒子のハードコート層に対する体積比率が１％よりも小さい場合や５０％より大きい場合は十分な光拡散機能を付与することができない。
【００４４】
ハードコート層の形成法は、特に制限されず、適宜な方式を採用することができる。例えば、ハードコート層形成樹脂溶液に透明粒子を含有させて塗工液を調製し、これをロールコート法、スピンコート法、ワイヤバーコート法、ディップコート法、エクストルージョン法、カーテンコート法、スプレコート法などの適宜な方式にて塗布後乾燥等させることにより透明粒子を含有したハードコート層を形成することができる。乾燥後、必要に応じて加熱処理、光照射処理ないし硬化処理することで被膜化する。
【００４５】
ハードコート層の厚さは、適宜に決定しうるが、一般には製造時の易剥離性や剥離の際にヒビ割れの生じることを防止する点などより、１μｍ〜１０μｍ、好ましくは８μｍ以下、特に２μｍ〜５μｍとすることが好ましい。
【００４６】
ハードコート層表面に凹凸構造を形成する場合は、その方法は特に限定されるものではないが、表面に凹部を形成した支持体の該凹部をハードコート層表面に転写し、ハードコート層表面に凹凸構造を形成するのが好ましい。支持体は通常、ベルト状や板状であり、具体的には流延用のエンドレスベルトや注型用の平板金型等が挙げられる。
【００４７】
ハードコート層上に所定の凹凸構造を形成するためには、支持体の表面粗さ（Ｒａ）が８０ｎｍ〜５００ｎｍであることが好ましく、さらに好ましくは１００μｍ〜４００μｍであるのが良い。また、支持体に形成された凹凸の山谷間隔は２０μｍ〜８０μｍであることが好ましく、さらに好ましくは３０μｍ〜７０μｍであるのが良い。
【００４８】
流延法においては、凹凸部が形成された支持体上に透明粒子を含有するハードコート層形成樹脂溶液を塗布後乾燥してハードコート層を形成し、ガスバリア層や基材層を積層させた後にこれらの積層体を支持体から剥離することにより、ハードコート層上に凹凸構造が形成された液晶セル基板を得ることができる。また、支持体側とは反対の最外層にもう１層ハードコート層を積層させることにより２層のハードコート層を有する液晶セル基板が得られる。この場合、このハードコート層は凹凸構造を有さない。
【００４９】
注型法においては、まず凹凸部が形成された金型と表面無垢な金型にハードコート層形成樹脂溶液を塗布後乾燥してハードコート層を形成する。次に、凹凸が形成された金型にガスバリア層形成樹脂含有液を塗布後乾燥しガスバリア層を形成させた後、２枚の金型を樹脂塗布面が向かい合うようにしてスペーサーやシーリング材を介して型組を行う。次にその隙間に基材層形成樹脂含有液を注入後硬化させ基材層を形成し、２枚の金型から剥離することにより、支持体に形成された凹部の転写でハードコート層上に凹凸構造が形成された液晶セル基板を得ることができる。また、ガスバリア層は、表面無垢な金型に形成されたハードコート層上に、ハードコート層形成樹脂液を塗布後、形成してもよい。
【００５０】
注型法においても凹凸が形成された金型の表面粗さ（Ｒａ）は８０ｎｍ〜５００ｎｍであることが好ましく、さらに好ましくは１００μｍ〜４００μｍであるのが良い。また、金型に形成された凹凸の山谷間隔は２０μｍ〜８０μｍであることが好ましく、さらに好ましくは３０μｍ〜７０μｍであるのが良い。
【００５１】
本発明においてハードコート層形成樹脂よりも屈折率の低い材料よりなる低屈折率層を形成する材料としては、例えば、紫外線硬化型アクリル樹脂等の樹脂系材料、樹脂中にコロイダルシリカ等の無機微粒子を分散させたハイブリッド系材料、テトラエトキシシラン、チタンテトラエトキシド等の金属アルコキシドを用いたゾル−ゲル系材料等があげられる。また、それぞれの材料は、表面の防汚染性付与するためフッ素基含有化合物が用いられる。耐擦傷性の面からは、無機成分含有量が多い低屈折率層材料が優れる傾向にあり、特にゾル−ゲル系材料が好ましい。
【００５２】
前記フッ素基を含有するゾル−ゲル系材料としては、パーフルオロアルキルアルコキシシランを例示できる。パーフルオロアルキルアルコキシシランとしては、たとえば、一般式（１）：ＣＦ_３（ＣＦ_２）ｎＣＨ_２ＣＨ_２Ｓｉ（ＯＲ）_３（式中、Ｒは、炭素数１〜５個のアルキル基を示し、ｎは０〜１２の整数である）で表される化合物があげられる。具体的には、たとえば、トリフルオロプロピルトリメトキシシラン、トリフルオロプロピルトリエトキシシラン、トリデカフルオロオクチルトリメトキシシラン、トリデカフルオロオクチルトリエトキシシラン、ヘプタデカフルオロデシルトリメトキシシラン、ヘプタデカフルオロデシルトリエトキシシランなどがあげられる。これらのなかでも前記ｎが２〜６の化合物が好ましい。
【００５３】
低屈折率材料としてフッ素基含有化合物を用いるとともに、正荷電を有する官能基および／または正荷電しうる官能基を有する化合物を用いて、見かけ上、反射防止層の最表面を電気的に中性化するようにしてもよい。反射防止層の最表面の帯電が低減されて、挨、塵等の付着性、抜き取り性の問題が解消可能となる。
【００５４】
前記の正荷電を有する官能基および／または正荷電しうる官能基を有する化合物としては、各種のものを使用できるが、当該官能基は、たとえば、アミノ基、アンモニウム塩基等の窒素原子を含む官能基や、燐酸基等のリン原子を含む官能基、スルホニウム基等のイオウ原子を含む官能基等があげられる。なかでも、アミノ基、アンモニウム塩基等の窒素原子を含む官能基が、挨、塵等の付着防止性、拭き取り性に優れており好ましい。
【００５５】
窒素原子を含む官能基を有する化合物としては、たとえば、ポリエチレンイミンや、テトラブチルアンモニウムブロマイド、テトラアンモニウムクロライド等の４級アンモニウム塩があげられる。また、特にシラン系化合物としては、γ−アミノプロピルトリメトキシシラン、γ−アミノプロピルトリエトキシシラン、Ｎ−（β−アミノエチル）−γ−アミノプロピルトリメトキシシラン、Ｎ−（β−アミノエチル）−γ−アミノプロピルトリエトキシシラン、Ｎ−（β−アミノエチル）−γ−アミノプロピルメチルジメトキシシラン等のシランカップリング剤があげられる。
【００５６】
フッ素基含有化合物と官能基を有する化合物との配合割合は特に制限されないが、フッ素基を含有する化合物１モル部に対して、官能基を有する化合物の配合割合を０．１〜１．５モル部程度、さらには０．５〜１モル部とするのが好ましい。官能基を有する化合物の配合割合が少ないと液体をはじく性質に係わる防汚染性は良好であるが、挨、塵等の付着防止性、抜き取り性が充分発現し難く、一方、多すぎると挨・塵等の付着防止性、抜き取り性は良好であるが防汚染性が低下する傾向がある。低屈折率層形成材料は、前記各化合物を前記配合割合となるように混合した塗工液として調製できる。
【００５７】
また、低屈折率層形成材にはシリカ、アルミナ、チタニア、ジルコニア、フッ化マグネシウム、セリア等をアルコール溶媒に分散したゾルなどを添加しても良い。その他、金属塩、金属化合物などの添加剤を適宜に配合することができる。
【００５８】
低屈折率層の屈折率は、ハードコート層の屈折率よりも低い。また基材層の屈折率よりも低くなるように調整するのが好ましい。低屈折率層の屈折率は、１．３５〜１．５０であるのが好ましい。
【００５９】
低屈折率層の形成法は、特に制限されず、適宜な方式にてハードコート層上に施される。例えば、ドクターブレード法、グラビアロールコーター法、デイッピング法、蒸着法等の適宜な方式にて形成することができる。低屈折率層の厚さは特に制限されず、通常、平均８０ｎｍ〜１５０ｎｍ程度である。
【００６０】
本発明による反射防止樹脂シートの流延法による製造例を図１に、注型法による製造例を図２に示した。
【００６１】
まず注型法においては、図２に示すように、表面無垢な金型（１３）にハードコート層形成樹脂溶液を塗布後乾燥してハードコート層を形成する。表面加工金型（１４）にハードコート層形成樹脂溶液を塗布後乾燥してハードコート層を形成し、さらにガスバリア層形成樹脂含有液を塗布後乾燥しガスバリア層を形成させる。その後、２枚の金型を樹脂塗布面が向かい合うようにしてスペーサー（１６）やシーリング材（１５）を介して型組を行う。次にその隙間に基材層形成樹脂含有液を注入後硬化させて基材層を形成し、２枚の金型から剥離した後、最外層に低屈折率層を形成することにより、本発明の反射防止樹脂シートを得ることができる。この場合、ハードコート層形成樹脂溶液に透明粒子を含有させ、塗布後乾燥させることにより透明粒子を含有したハードコート層を形成することができる。
【００６２】
図１に例示の製造工程は、支持体にエンドレスベルトを用いて流延法により反射防止樹脂シートを連続製造するものである。
【００６３】
図１に例示の流延法にては、エンドレスベルト（１）からなる支持体を駆動ドラム（４）および従動ドラム（５）を介し、例えば０．１〜５０ｍ／分、好ましくは０．２〜５ｍ／分の一定速度で走行させつつ、その上にダイ（７）よりハードコート層形成樹脂溶液、ダイ（９）よりガスバリア層形成樹脂含有液を塗布して乾燥、あるいは必要に応じ加熱または光照射等により硬化処理して皮膜（１０）、（１１）とする。なお図例では加熱装置（３）、ＵＶ硬化装置（８）が配置されている。また、エンドレスベルト（１）には凹凸部が形成されており、その表面粗さ（Ｒａ）や凹凸の山谷間隔（Ｓｍ）は上記した通りである。
【００６４】
また、ハードコート層形成樹脂溶液に透明粒子を含有させ、塗布後乾燥させることによって、透明粒子を含有したハードコート層を形成することができる。
【００６５】
次に、皮膜（１０）、（１１）の上にダイ（２）を介して基材層形成樹脂含有液を塗布してシート状に展開し、加熱または光照射により完全に硬化させ、皮膜（６）とする。図例では加熱装置（３）が配置されており、加熱方法は熱風、赤外線ヒーター等により行い、これらを併用してもよい。熱風風速は通常０．１〜５ｍ／ｓｅｃであるが、熱可塑性もしくは熱硬化性樹脂含有液の加熱の場合は０．２〜１ｍ／ｓｅｃが好ましい。
【００６６】
前記加熱装置（３）は樹脂含有液の温度依存による低粘度化、硬化反応による増粘化で起こる粘度変化をコントロールするため、１０ゾーン程度に分かれていることが好ましい。また、各ゾーンともエンドレスベルトの上面、下面、もしくは両面で加熱が可能である。加熱温度は３０〜２５０℃が好ましい。加熱温度精度は±０．５℃／ｃｍ以下が好ましく、さらに好ましくは±０．１℃／ｃｍ以下がよい。加熱温度が３０℃未満であると基材層形成樹脂が硬化しにくくなる。加熱温度が２５０℃を超えると基材層形成樹脂含有液の粘度が低下するため、樹脂シートの厚みの精度が悪くなる。また加熱温度精度が±０．５℃／ｃｍより大きくなると樹脂シートの厚みの精度が悪くなり外観不良が生じやすくなる。
【００６７】
基材層形成樹脂含有液を吐出させるダイ（２）の温度は１０〜４０℃が好ましく、さらに好ましくは２０〜３０℃がよい。またダイの温度精度は±０．５℃以下が好ましく、さらに好ましくは±０．１℃以下がよい。ダイの温度が１０℃未満になると、基材層形成樹脂含有液の粘度が上昇するため、操作性の面で問題がある。４０℃を超えるとダイ中で基材層形成樹脂の硬化が進むので塗工が困難となる。またダイの温度精度が±０．５℃より大きくなると、樹脂シートの厚みの精度が悪くなり外観不良が生じやすくなる。
【００６８】
吐出させる基材層形成樹脂含有液の粘度は０．１Ｐａ・ｓ〜５０Ｐａ・ｓが好ましく、エクストルージョンコートを行う場合は１５Ｐａ・ｓ〜３０Ｐａ・ｓが好ましい。前記樹脂含有液の粘度が０．１Ｐａ・ｓ未満の場合は樹脂シートの厚みの精度が悪くなる。前記樹脂含有液の粘度が５０Ｐａ・ｓを超える場合は操作性が悪くなる。
【００６９】
また基材層形成樹脂含有液の塗布方法としては、カーテンコート、エクストルージョンコート、ロールコート等が好ましく、特に好ましくはエクストルージョンコートがよい。
【００７０】
また加熱装置のエンドレスベルトの裏面にはガイドロールを設置しており、水平度レベルセンサーによって水平レベルを調整することができる。支持体水平レベルは１ｍｍ／（５×有効巾）ｍｍ以下が好ましく、さらに好ましくは１ｍｍ／（４０×有効巾）ｍｍ以下がよい。水平レベルが１ｍｍ／（５×有効巾）ｍｍよりも大きい場合は樹脂シートの厚みの精度が悪くなる。
【００７１】
流延法でハードコート層を２層有する樹脂シートを得るためには、エンドレスベルトとは反対の最外層にハードコート層形成樹脂溶液を塗布して乾燥、あるいは必要に応じて加熱または光照射等により硬化処理すればよい。この場合、第１のハードコート層、ガスバリア層、基材層からなる積層体をエンドレスベルト１より剥離後スピンコート法や単板ダイコータ等により第２のハードコート層を形成することができる。またハードコート層形成樹脂溶液に透明粒子を含有させることにより、透明粒子を含有したハードコート層を形成することができる。
【００７２】
また、支持体の両側に液流れ防止の堰を耐熱性の樹脂で設けてもよい。具体的にはポリエチレンテレフタレート等が好ましく用いられる。
【００７３】
支持体からの樹脂シートの回収に際しては、必要に応じ剥離手段を用いることができる。またかかる回収は、割れ防止などの点よりガラス転移点以上の等の高温雰囲気下で行うことが好ましい。さらに形成された連続状態の樹脂シートは、レーザー光線や超音波カッター、ダイシングやウォータージェットなどの適宜な切断手段を介し適宜な寸法に切断して回収することもできる。前記の流延法によれば、支持体を介した展開層の移動速度の調節で製造速度を容易に制御でき、またその移動速度や展開量の調節で得られる樹脂シートの厚さも容易に制御することができる。このようにして回収した樹脂シートのハードコート層上に低屈折率層を適宜な方法で形成することにより、本発明の反射防止シートを得ることができる。
【００７４】
図３〜図５には、本発明の液晶セル基板（反射防止樹脂シート）３１を搭載した液晶表示装置の構成例を示した。図中、１７が低屈折率層、１１８が透明粒子を含有するハードコート層、１９がガスバリア層、２０が基材層である。１８は透明粒子を含有しないハードコート層である。
【００７５】
液晶表示装置は一般に、偏光板、液晶セル、反射板又はバックライト、及び必要に応じての光学部品等の構成部品を適宜に組み立てて駆動回路を組み込むことなどにより形成される。本発明においては、上記した液晶セル基板を用いる点を除いて特に限定はなく、従来に準じて形成することができる。従って、本発明における液晶表示装置の形成に際しては、例えば視認側の偏光板の上に設ける光拡散板、アンンチグレア層、反射防止膜、保護層、保護板、あるいは液晶セルと視認側の偏光板の間に設ける補償用位相差板などの適宜な光学部品を前記液晶セル基板に適宜に組み合わせることができる。なお、本発明においては、視認性向上のために、透明粒子含有ハードコート層が液晶層に最も近くなるような視認側に液晶セル基板を配置することが好ましい。
【００７６】
次いで、有機エレクトロルミネセンス装置（有機ＥＬ表示装置）について説明する。一般に、有機ＥＬ表示装置は、透明基板上に透明電極と有機発光層と金属電極とを順に積層して発光体（有機エレクトロルミネセンス発光体）を形成している。ここで、有機発光層は、種々の有機薄膜の積層体であり、例えばトリフェニルアミン誘導体等からなる正孔注入層と、アントラセン等の蛍光性の有機固体からなる発光層との積層体や、あるいはこのような発光層とペリレン誘導体等からなる電子注入層の積層体や、またあるいはこれらの正孔注入層、発光層、および電子注入層の積層体等、種々の組み合わせをもった構成が知られている。
【００７７】
有機ＥＬ表示装置は、透明電極と金属電極とに電圧を印加することによって、有機発光層に正孔と電子とが注入され、これら正孔と電子との再結合によって生じるエネルギーが蛍光物質を励起し、励起された蛍光物質が基底状態に戻るときに光を放射する、という原理で発光する。途中の再結合というメカニズムは、一般のダイオードと同様であり、このことからも予想できるように、電流と発光強度は印加電圧に対して整流性を伴う強い非線形性を示す。
【００７８】
有機ＥＬ表示装置においては、有機発光層での発光を取り出すために、少なくとも一方の電極が透明でなくてはならず、通常酸化インジウムスズ（ＩＴＯ）などの透明導電体で形成した透明電極を陽極として用いている。一方、電子注入を容易にして発光効率を上げるには、陰極に仕事関数の小さな物質を用いることが重要で、通常Ｍｇ−Ａｇ、Ａｌ−Ｌｉなどの金属電極を用いている。
【００７９】
このような構成の有機ＥＬ表示装置において、有機発光層は、厚さ１０ｎｍ程度ときわめて薄い膜で形成されている。このため、有機発光層も透明電極と同様、光をほぼ完全に透過する。その結果、非発光時に透明基板の表面から入射し、透明電極と有機発光層とを透過して金属電極で反射した光が、再び透明基板の表面側へと出るため、外部から視認したとき、有機ＥＬ表示装置の表示面が鏡面のように見える。
【００８０】
電圧の印加によって発光する有機発光層の表面側に透明電極を備えるとともに、有機発光層の裏面側に金属電極を備えてなる有機エレクトロルミネセンス発光体を含む有機ＥＬ表示装置において、透明電極の表面側に偏光板を設けるとともに、これら透明電極と偏光板との間に位相差板を設けることができる。
【００８１】
位相差板および偏光板は、外部から入射して金属電極で反射してきた光を偏光する作用を有するため、その偏光作用によって金属電極の鏡面を外部から視認させないという効果がある。特に、位相差板を１／４波長板で構成し、かつ偏光板と位相差板との偏光方向のなす角をπ／４に調整すれば、金属電極の鏡面を完全に遮蔽することができる。
【００８２】
すなわち、この有機ＥＬ表示装置に入射する外部光は、偏光板により直線偏光成分のみが透過する。この直線偏光は位相差板により一般に楕円偏光となるが、とくに位相差板が１／４波長板でしかも偏光板と位相差板との偏光方向のなす角がπ／４のときには円偏光となる。
【００８３】
この円偏光は、透明基板、透明電極、有機薄膜を透過し、金属電極で反射して、再び有機薄膜、透明電極、透明基板を透過して、位相差板に再び直線偏光となる。そして、この直線偏光は、偏光板の偏光方向と直交しているので、偏光板を透過できない。その結果、金属電極の鏡面を完全に遮蔽することができる。
【００８４】
【実施例】
以下に実施例を挙げて本発明を説明するが、本発明はこれら実施例になんら限定されるものではない。各例中、特に言及しない限り、部および％は重量基準である。本発明の屈折率の測定は、（株）アタゴ製アッベ屈折率計により行った。
【００８５】
実施例１
（低屈折率層形成剤の調製）
トリデカフルオロヘキシルトリエトキシシラン１モル部に対し、γ−アミノプロピルトリメトキシシラン１モル部を配合し、さらにエタノール溶媒にて固形成分が約１％になるように調整して、低屈折率層形成剤を調製した。
【００８６】
（ハードコート層形成樹脂液の調製）
ＵＶ硬化樹脂であるＮＫオリゴＵＮ−０１（新中村化学製；固形分８５％）１００重量部、イルガキュア♯１８４（チバ・スペシャリティー・ケミカルズ製）３重量部に、トルエン４５０重量部を混合攪拌して、樹脂固形分濃度１６％のハードコート層形成樹脂溶液を得た。
【００８７】
（透明粒子含有ハードコート層形成樹脂液の調製）
ＵＶ硬化樹脂であるＮＫオリゴＵＮ−０１（新中村化学製；固形分８５％）１００重量部、イルガキュア♯１８４（チバ・スペシャリティー・ケミカルズ製）３重量部、平均粒径が１．８μｍの合成シリカ粒子（屈折率１．４６）２８重量部に、トルエン４５０重量部を混合攪拌して樹脂固形分濃度２０％の透明粒子含有ハードコート層形成樹脂溶液を得た。
【００８８】
（基材層形成樹脂液の調製）
（化２）の化学式で示される３，４−エポキシシクロヘキシルメチル−３，４−エポキシシクロヘキサンカルボキシレート４００重量部と（化３）の化学式で示されるメチルヘキサヒドロ無水フタル酸５００重量部、（化４）の化学式で示されるテトラ−ｎ−ブチルホスホニウムｏ，ｏ−ジエチルホスホロジチオエート１５重量部、グリセリン９重量部、界面活性剤１重量部を混合攪拌して基材層形成樹脂含有液を得た。
【００８９】
【化２】

【化３】

【化４】

【００９０】
（液晶セル基板の作製）
次に、図２に示した金型を用いて、注型法により液晶セル基板を製造した。その製造方法を図２及び図３を参照しながら説明する。
【００９１】
まず、金型として１枚は４５０ｍｍ×４５０ｍｍ、表面粗さＲａ＝５ｎｍの無垢金型（１３）を用いた。もう一方は４５０ｍｍ×４５０ｍｍ、表面粗さＲａ＝１００ｎｍ、山谷間隔３０μｍに表面加工した表面加工金型（１４）を用いた。まず、無垢金型（１３）の加工面にハードコート層形成樹脂溶液をスピンコートにより塗布し、トルエンを乾燥後、ＵＶを照射（中心波長２５４ｎｍ、積算光量２０００ｍＪ／ｃｍ^２）して、膜厚２μｍのハードコート層（１８）を形成した。次に他方の表面加工金型（１４）の加工面に透明粒子を含有するハードコート層形成樹脂溶液をスピンコートにより塗布し、トルエンを乾燥後、ＵＶを照射（中心波長２５４ｎｍ、積算光量２０００ｍＪ／ｃｍ^２）して、膜厚が２μｍのハードコート層（１１８）を形成した。ハードコート層の屈折率は１．５１であった。
【００９２】
次に、表面加工金型（１４）に形成されたハードコート層（１１８）上にポリビニルアルコール（重合度：１，８００）の５．５重量％水溶液をスピンコート法で塗布後乾燥して硬化し、膜厚３．７μｍのガスバリア層（１９）を形成した。
【００９３】
次に、その２枚の金型の樹脂形成面を向かい合わせるようにして、図２に示したように、隙間調整用スペーサー（１６）及びシーリング剤（１５）を介して、隙間の幅が４００μｍとなるように注型用金型を組み立てた。その隙間に上記で調製した基材層形成樹脂含有液を注入し、１２０℃×３０分＋１８０℃×１時間硬化させた。その後、２枚の金型を、割り開くと同時に、樹脂層と金型の界面を剥離して樹脂シートを取り出した後、ハードコート層（１１８）上に上記で調製した低屈折率層形成剤を、乾燥・硬化時に平均厚み約１００ｎｍになるように塗工して低屈折率層（１７）を形成し、反射防止樹脂シート（３１）からなる液晶セル基板＜ａ＞を得た。この時の乾燥・硬化条件は９０℃、４０時間とした。低屈折率層の屈折率は１．４０であった。
【００９４】
得られた液晶セル基板＜ａ＞は、金型の凹凸部が転写された面は表面粗さＲａ＝１００ｎｍ、山谷間隔は４５μｍであり、もう一方は表面粗さＲａ＝５ｎｍであった。また液晶セル基板＜ａ＞の平均厚みは４００μｍ、厚みの標準偏差は９μｍであった。
【００９５】
次に、液晶を挟んでもう一方の液晶セル基板を以下のように作製した。まず２枚の表面無垢金型に上記ハードコート層形成樹脂溶液を塗布後乾燥させハードコート層（１８）を形成した。次にその２枚の金型の樹脂形成面を向かい合わせるようにして、図２に示したように、隙間調整用スペーサー及びシーリング剤を介して、隙間の幅が４００μｍとなるように注型用金型を組み立てた。
【００９６】
そしてその隙間に、黒色顔料三菱カーボンブラックＭＡ１００を、基材層形成樹脂含有液：ＭＡ１００＝１０：１（重量比）の割合で分散した黒色顔料含有基材層形成樹脂含有液を注入した後、１２０℃×３０分＋１８０℃×１時間硬化させ、金型より液晶セル基板＜ｂ＞を取り出した。得られた液晶セル基板＜ｂ＞は、両面の表面粗さＲａ＝４ｎｍ、平均厚みは４００μｍ、厚みの標準偏差は８μｍであった。
【００９７】
（液晶セルの作製）
得られた液晶セル基板＜ａ＞と＜ｂ＞を所定の形状に切り出した後、Ａｒ雰囲気中でプラズマ処理を施し、酸化インジウム・スズ（ＩＴＯ）薄膜をスパッタリングにて形成した。次に、液晶セル基板＜ａ＞のハードコート層（１８）上、および樹脂シート＜ｂ＞のどちらか片面のハードコート層上にＩＴＯ薄膜（２１）を形成した。
【００９８】
その後、液晶セル基板＜ａ＞のＩＴＯ薄膜（２１）を２分割した後、ラビング膜（２２）のラビング方向が直交するように上記基板の一対をＩＴＯ薄膜（２１）を対向させて、球形のガラスビーズよりなるギャップ調整材を配した後、シール材で固定した。その後、トリメチルプロパントリアクリレート（ＴＭＰＴＡ）１０部、および２−ヒドロキシエチルアクリレート（ＨＥＡ）１０部、およびアクリルオリゴマー（東亜合成化学「Ｍ−１２００」）２５部、光硬化開始剤としてメルク社製「ダロキュア−１１７３」を０．５部、液晶としてＢＤＨ社製液晶「Ｅ７」を５０部混合し、均一に溶解させた混合液を注入した。その後、セルの液晶セル基板＜ａ＞側から紫外線を照射し、図３に例示の液晶セルを作製した。
【００９９】
実施例２
２層のハードコート層が透明粒子を含有するように、２層とも透明粒子含有ハードコート層形成樹脂溶液を塗布した以外は、実施例１と同様にして液晶セル基板＜ａ’＞を形成した。その後、実施例１と同様に液晶セル基板＜ｂ＞と組合せ、図４に例示の液晶セルを作製した。
【０１００】
実施例３
図１に示す装置を用いて、流延法により液晶セル基板を製造した。まず実施例１で調製した透明粒子含有ハードコート層形成樹脂溶液をダイ（７）より吐出させ、ステンレス製エンドレスベルト（１）（表面粗さＲａ＝１００ｎｍ、山谷間隔４０μｍ）に走行速度：０．２ｍ／分で流延塗布し、トルエンを揮発させて、ＵＶ硬化装置（８）で硬化（中心波長２５４ｎｍ、積算光量２０００ｍＪ／ｃｍ^２）し、膜厚５μｍ、幅５００ｍｍのハードコート層（１１）を得た。
【０１０１】
続いて、ポリビニリルアルコールの５．５重量％水溶液を、ダイ（９）より吐出させ、ハードコート層上に流延塗布し、加熱乾燥（６０℃×１０分）させ、膜厚４μｍ、幅４５０ｍｍのガスバリア層（１０）を得た。
【０１０２】
得られたハードコート層、ガスバリア層の両端に幅４０ｍｍの耐熱ＰＥＴ基材テープ（ＭＴ−３１５５：日東電工社製）を貼付け、実施例１と同様の基材層形成樹脂含有液（２０Ｐａ・ｓ、２５℃）を、ダイ２より吐出させ、上記ガスバリア層の表面に、塗工幅４３０ｍｍで流延塗布し、加熱装置（３）により、９０℃×５分、１２０℃×５分、１４０℃×１５分で硬化させて基材層（６）を形成し、１３０℃に温調されたドラム（５）上でステンレス製エンドレスベルトとハードコート層間で剥離を行い４３０ｍｍ幅の液晶セル基板を得た。尚、加熱部の支持体水平レベルを２００μｍ／１０００ｍｍ、支持体上下より熱風加熱を行い温度精度０．４℃／ｃｍとした。ハードコート層上に実施例１で調製した低屈折率層形成剤を、実施例１と同様の条件にて塗工し低屈折率層を形成し、反射防止樹脂シートからなる液晶セル基板＜ｃ＞を得た。
【０１０３】
得られた液晶セル基板＜ｃ＞を流れ方向に４９０ｍｍ間隔で切断を行い、４９０ｍｍ×４９０ｍｍのサイズとした。得られた液晶セル基板＜ｃ＞の厚みの平均は４００μｍ、標準偏差は７μｍであった。なお、厚みの平均値、及び標準偏差は４８０ｍｍ×４８０ｍｍの面内で６０点測定して求めた。また、表面粗さは、基材層側でＲａ＝０．２ｎｍ、低屈折率層側でＲａ＝１００ｎｍであった。なお、表面粗さは、４８０ｍｍ×４８０ｍｍの面内で１０点測定した平均値である。
【０１０４】
続いて、液晶セル基板＜ｃ＞のハードコート層側にＩＴＯ薄膜を形成し、実施例１と同様に液晶セル基板＜ｂ＞と組合せ、図５に例示の液晶セルを作製した。
【０１０５】
比較例１
ハードコート層上に低屈折率層を形成しない以外は、実施例１と同様にして液晶セル基板＜ｄ＞を作製した。次に実施例１と同様に液晶セル基板＜ｂ＞と組合せ、図６に例示の液晶セルを作製した。
【０１０６】
（評価試験）
実施例１〜３及び比較例１で作製した液晶セルを用いて液晶表示装置を組み立て、暗室中で２０°の角度でリング状照明装置を照射して、液晶表示装置の電圧印加状態で黒色表示の表示品位を調べ、電圧無印加状態で白色表示の表示品位を調べた。
【０１０７】
（反射率）
反射防止樹脂シートの低屈折率層とは反対側の最外層を、サンドペーパーを用いて荒らした後、黒のアクリルラッカーを塗布して反射防止層に対して裏面側の反射光をなくした状態で、傾斜積分球付き分光光度計（島津製作所製ＵＶ−２４００）を用いて、全反射率を測定した。なお、反射率の測定にあたっては、上記分光反射率からＣＩＥ１９３１ＸＹＺ表色系に基づき、Ｃ光源に対する視感度補正した反射率Ｙを採用した。
【０１０８】
実施例１〜３においては、黒色表示、白色表示ともに表示品位は良好であった。一方、比較例１においては白色表示においては液晶表面での照明の反射が原因と思われるぎらつきが見られた。また、実施例１〜３で得た樹脂シートの反射率は２．６であったが、比較例１では反射率は３．２％となった。以上の結果から、低屈折率層を設けた場合は、反射が抑制されていた。
【０１０９】
【発明の効果】
以上説明したとおり、本発明によれば、基材層、ガスバリア層、外側表面に凹凸構造を有するハードコート層がこの順で積層され、当該ハードコート層上に当該ハードコート層形成樹脂よりも屈折率の低い材料よりなる低屈折率層が形成されているため、蛍光灯や太陽光等の照明光やキーボーダーなどの外部環境が画面上に映り込む、いわゆるゴースト現象を防止する防眩機能を有するとともに、前記凹凸構造を有するハードコート層が透明粒子を含有するため、照明光などの外部光や液晶表示装置内蔵のバックライトに起因するギラツキを防止する光拡散機能を有する、薄型かつ軽量の反射防止樹脂シートが得られる。
【０１１０】
この反射防止樹脂シートを液晶セル基板、有機ＥＬ表示装置用基板等の画像表示装置用基板に用いることにより、ガラス系基板に比べて薄型かつ軽量で、しかも耐久性に優れた基板となる。また液晶セル基板に防眩機能と光拡散機能の双方が付与されることにより、防眩シートや光拡散シートを液晶セルの視認側に貼り付ける必要がなくなり、その結果液晶セルの薄型、軽量化が可能になる。
【図面の簡単な説明】
【図１】流延法による液晶セル基板の製造方法の一例を説明する図である。
【図２】注型法による液晶セル基板の製造方法の一例を説明する図である。
【図３】実施例１の液晶セルの構成を示す断面模式図である。
【図４】実施例２の液晶セルの構成を示す断面模式図である。
【図５】実施例３の液晶セルの構成を示す断面模式図である。
【図６】比較例１の液晶セルの構成を示す断面模式図である。
【符号の説明】
１：エンドレスベルト（支持体）
２：基材層塗布用ダイ
３：加熱装置
４：駆動ドラム
５：従動ドラム
６：基材層
７：ハードコート層塗布用ダイ
８：ＵＶ硬化装置
９：ガスバリア層塗布用ダイ
１０：ガスバリア層
１１：ハードコート層
１２：端部補強テープ
１３：表面無垢金属金型
１４：表面加工金属金型
１５：シーリング材
１６：隙間調整用スペーサー
１７：低屈折率層
１８：ハードコート層
１１８：透明粒子を含有するハードコート層
１９：ガスバリア層
２０：基材層
２１：ＩＴＯ
２２：ラビング膜
２３：液晶
２４：黒色顔料を有する基材層
３１：液晶セル基板（反射防止樹脂シート）[0001]
[Industrial applications]
INDUSTRIAL APPLICABILITY The present invention prevents ghost and glare, and forms an antireflection resin sheet capable of forming an image display device substrate and the like having excellent antiglare and light diffusion properties, and a liquid crystal display device and an electroluminescence display device using the same. The present invention relates to an image display device.
[0002]
[Prior art]
One of various image display devices is a liquid crystal display device. In recent years, however, a demand for improved visibility has been further increased. In order to make the display device easier to see, for example, to pursue higher definition and higher image quality of the liquid crystal display device, it is necessary to minimize reflection, reflection, and glare of external light on the liquid crystal display device. In particular, when a car navigation monitor, a video camera monitor, a mobile phone, a PHS, various portable information terminals, and the like are used outdoors, the decrease in visibility is more remarkable than when they are used indoors.
[0003]
For this reason, in an image display device such as a liquid crystal display device, a light diffusion sheet having transparent particles is attached to the viewing side of a liquid crystal cell to prevent glare caused by illumination light and a backlight built in the liquid crystal display device, and to reduce glare. There have been known methods for improving the performance. In addition, an anti-glare sheet having an uneven structure on the surface is attached to the viewing side of the liquid crystal cell to prevent a so-called ghost phenomenon in which an external environment such as an illumination light such as a fluorescent lamp or sunlight or a keyboard is reflected on a screen. The method was known.
[0004]
However, instead of attaching a light-diffusing sheet or anti-glare sheet to the viewing side of the liquid crystal cell from the viewpoint of making the liquid crystal display device thinner and lighter, consideration is given to providing the liquid crystal cell substrate with a light diffusing function or an anti-glare function. Have been.
[0005]
[Problems to be solved by the invention]
The present invention is based on an anti-glare function for preventing a so-called ghost phenomenon in which an external environment such as an illumination light such as a fluorescent lamp or sunlight or a keyboard is reflected on a screen, and an illumination light or a backlight built in a liquid crystal display device. A substrate for an image display device such as a liquid crystal cell substrate or a substrate for an electroluminescent display device (hereinafter, an organic EL display device), which has a light diffusion function for preventing glare and is thin, lightweight, and excellent in durability. It is an object of the present invention to provide an antireflection resin sheet capable of forming the same, and an image display device such as a liquid crystal display device and an organic EL display device using the same.
[0006]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above problems, and as a result, provided a hard coat layer having an uneven structure on the base material layer so that the uneven structure is on the outer surface, and further on the uneven structure. By forming a low-refractive-index layer made of a material having a lower refractive index than the resin forming the hard-coat layer, and by including transparent particles in the hard-coat layer, the ghost phenomenon can be prevented and the liquid crystal display can be formed. The present inventors have found that a thin and lightweight antireflection sheet can be obtained in which reflection of external light, reflection, glare, and the like can be suppressed, and a remarkable antiglare function and light diffusion function are exhibited by a synergistic effect. Reached.
[0007]
That is, a substrate layer, a gas barrier layer, and a hard coat layer having an uneven structure on the outer surface are laminated in this order, and a low refractive index material having a lower refractive index than the resin for forming the hard coat layer is formed on the hard coat layer. An object of the present invention is to provide an antireflection resin sheet on which a refractive index layer is formed, wherein the hard coat layer having the uneven structure contains transparent particles. In an image display device, if moisture or oxygen permeates the liquid crystal cell substrate and enters the cell, the liquid crystal may be degraded or the appearance may be poor due to the formation of bubbles, and the transparent conductive film pattern may be disconnected. By providing a gas barrier layer between the material layer and the hard coat layer, moisture and gas permeation can be prevented.
[0008]
In the antireflection resin sheet, it is preferable that another hard coat layer is laminated on the side of the base material layer opposite to the gas barrier layer. The hard coat layer can function as a surface coat layer of the base material layer by forming one surface layer of the resin sheet. Therefore, by providing such a hard coat layer, the chemical resistance, scratch resistance, etc. of the resin sheet can be improved. Is improved. The hard coat layer laminated on the opposite side of the substrate layer from the gas barrier layer preferably contains transparent particles. For the purpose of optical use, it is desirable to have excellent optical characteristics such as transparency, and by including transparent particles, a light diffusion function is provided and glare caused by the backlight can be prevented. . The transparent particles may be optically transparent particles.
[0009]
In the antireflection resin sheet of the present invention, the transparent particles are preferably spherical particles having a refractive index difference of 0.03 to 0.10. When the refractive index difference is smaller than 0.03 or larger than 0.10, a sufficient light diffusion function cannot be provided. Also, by using spherical particles, the dispersibility of the particles is improved, and the optical characteristics are improved.
[0010]
In order to obtain an anti-reflection resin sheet having a good anti-reflection effect and high display quality, the refractive index should be in the above-mentioned relationship: hard coat layer> base layer> low refractive index layer. It is preferable that the refractive index difference is large. Therefore, in the antireflection resin sheet of the present invention, the refractive index of the hard coat layer is 1.45 to 1.80, and the refractive index of the low refractive index layer is 1.35 to 1.50. Is preferred. By laminating the low refractive index layer having the above-mentioned refractive index on the hard coat layer having the above-mentioned refractive index, a good antireflection effect can be obtained. However, it is necessary that the refractive index of the low refractive index layer <the refractive index of the hard coat layer.
[0011]
In the antireflection resin sheet of the present invention, it is preferable that the surface roughness of the uneven structure is 80 nm to 500 nm. Alternatively, it is preferable that the interval between the peaks and valleys of the uneven structure is 20 μm to 80 μm.
[0012]
In the antireflection resin sheet of the present invention, the base layer is preferably made of an epoxy resin, and the hard coat layer is preferably made of a urethane resin. For the substrate layer, a thermosetting resin is preferably used in order to obtain surface smoothness, and among the thermosetting resins, an epoxy resin is particularly preferably used from the viewpoint of hue. The urethane-based resin is preferably used for the hard coat layer from the viewpoints of optical characteristics and easy peelability from the support described later, particularly easy peelability from the stainless steel support and hard coat properties.
[0013]
The method for producing the anti-reflection resin sheet is not particularly limited, but it is preferable that the concavo-convex structure is formed by transferring a concave portion formed on the surface of the support. By forming the concavo-convex structure by such a method, a dense, uniform and regular concavo-convex structure can be easily formed, so that the ghost phenomenon is more effectively prevented.
[0014]
Further, the present invention provides a substrate for an image display device, a substrate for a solar cell, and an image display device using the same, comprising the antireflection resin sheet described above. Examples of the substrate for an image display device include a liquid crystal cell substrate and a substrate for an organic EL display device.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The antireflection resin sheet of the present invention has a substrate layer, a gas barrier layer, and a hard coat layer having an uneven structure on the outer surface laminated in this order, and has a refractive index higher than that of the hard coat layer forming resin on the hard coat layer. An antireflection resin sheet on which a low refractive index layer made of a material having a low refractive index is formed, wherein the hard coat layer having the uneven structure contains transparent particles. Another hard coat layer may be laminated on the side of the substrate layer opposite to the gas barrier layer. In these cases, the gas barrier layer may be inferior in impact resistance and chemical resistance to the hard coat layer and the base material layer. Therefore, it is better not to laminate the gas barrier layer on the outermost layer.
[0016]
In the present invention, as the resin forming the base layer, polycarbonate, polyarylate, polyether sulfone, polysulfone, polyester, polymethyl methacrylate, thermoplastic resin such as polyetherimide or polyamide, epoxy resin, unsaturated polyester, Thermosetting resins such as polydiallyl phthalate and polyisobonyl methacrylate are exemplified. One or more of these resins can be used, and they can be used as a copolymer or a mixture with other components. A thermosetting resin is preferable for obtaining the surface smoothness of the sheet, and among the thermosetting resins, an epoxy resin is most preferably used in terms of hue.
[0017]
In the present invention, as the epoxy resin forming the base layer, for example, bisphenol type such as bisphenol A type, bisphenol F type, bisphenol S type and water addition thereof, novolak type such as phenol novolak type and cresol novolak type; Nitrogen-containing ring type such as triglycidyl isocyanurate type and hydantoin type, aromatic type such as alicyclic type, aliphatic type and naphthalene type, low water absorption type such as glycidyl ether type and biphenyl type, dicyclo type and ester type , Ether ester types and their modified forms. These may be used alone or in combination. Among the above various epoxy resins, it is preferable to use a bisphenol A type epoxy resin, an alicyclic epoxy resin, or a triglycidyl isocyanurate type from the viewpoint of anti-discoloration properties.
[0018]
As such an epoxy resin, generally, an epoxy resin having an epoxy equivalent of 100 to 1000 and a softening point of 120 ° C. or less is preferably used from the viewpoint of physical properties such as flexibility and strength of a liquid crystal cell substrate to be obtained. From the viewpoint of obtaining an epoxy resin-containing liquid having excellent coatability and spreadability into a sheet, etc., a two-liquid mixed type liquid which shows a liquid state at a temperature lower than the temperature at the time of coating, particularly at room temperature, can be preferably used.
[0019]
Epoxy resins are known in the art such as curing agents, curing accelerators, and, if necessary, conventionally used antioxidants, denaturing agents, surfactants, dyes, pigments, discoloration inhibitors, and ultraviolet absorbers. Can be appropriately compounded.
[0020]
The curing agent is not particularly limited, either, and one or more curing agents appropriate for the epoxy resin can be used. Incidentally, examples include tetrahydrophthalic acid, methyltetrahydrophthalic acid, organic acid compounds such as hexahydrophthalic acid and methylhexahydrophthalic acid, ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine and their amine adducts, meta Examples include amine compounds such as phenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone.
[0021]
Also, amide compounds such as dicyandiamide and polyamide, hydrazide compounds such as dihydrazide, methylimidazole, 2-ethyl-4-methylimidazole, ethylimidazole, isopropylimidazole, 2,4-dimethylimidazole, phenylimidazole, undecyl Imidazole compounds such as imidazole, heptadecyl imidazole and 2-phenyl-4-methylimidazole are also examples of the curing agent.
[0022]
Furthermore, imidazoline such as methylimidazoline, 2-ethyl-4-methylimidazoline, ethylimidazoline, isopropylimidazoline, 2,4-dimethylimidazoline, phenylimidazoline, undecylimidazoline, heptadecylimidazoline and 2-phenyl-4-methylimidazoline Compounds, phenol compounds, urea compounds and polysulfide compounds are also examples of the curing agent.
[0023]
In addition, acid anhydride-based compounds and the like are also mentioned as examples of the curing agent, and from the viewpoint of preventing discoloration, such acid anhydride curing agents can be preferably used. Examples include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, nadic acid anhydride, glutaric anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, Examples include methylhexahydrophthalic anhydride, methylnadic anhydride, dodecenylsuccinic anhydride, dichlorosuccinic anhydride, benzophenonetetracarboxylic anhydride and chlorendic anhydride.
[0024]
Particularly, a colorless or pale yellow acid anhydride curing agent having a molecular weight of about 140 to about 200, such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride. Is preferably used.
[0025]
The mixing ratio of the epoxy resin and the curing agent, when an acid anhydride curing agent is used as the curing agent, the acid anhydride equivalent is 0.5 to 1.5 equivalents to 1 equivalent of the epoxy group of the epoxy resin. It is preferable to mix them in such a manner that they are more preferably 0.7 to 1.2 equivalents. When the amount of the acid anhydride is less than 0.5 equivalent, the hue after curing becomes worse, and when the amount exceeds 1.5 equivalents, the moisture resistance tends to be reduced. When other curing agents are used alone or in combination of two or more, the amount used is in accordance with the above equivalent ratio.
[0026]
Examples of the curing accelerator include tertiary amines, imidazoles, quaternary ammonium salts, organic metal salts, phosphorus compounds, urea compounds, and the like, and particularly, tertiary amines, imidazoles and the like. It is preferable to use phosphorus compounds. These can be used alone or in combination.
[0027]
The compounding amount of the curing accelerator is preferably 0.05 to 7.0 parts by weight, more preferably 0.2 to 3.0 parts by weight, based on 100 parts by weight of the epoxy resin. If the amount of the curing accelerator is less than 0.05 part by weight, a sufficient curing promoting effect cannot be obtained, and if it exceeds 7.0 parts by weight, the cured product may be discolored.
[0028]
Examples of the antioxidant include conventionally known compounds such as a phenol compound, an amine compound, an organic sulfur compound and a phosphine compound.
[0029]
Examples of the modifier include conventionally known modifiers such as glycols, silicones and alcohols.
[0030]
The surfactant is added to smooth the surface of the sheet when the epoxy-based liquid crystal cell substrate is formed by casting the epoxy resin while contacting air. Examples of the surfactant include a silicone type, an acrylic type, a fluorine type and the like, and a silicone type is particularly preferable.
[0031]
The method for forming the base material layer is not particularly limited, and an appropriate method can be adopted. For example, the epoxy resin coating solution can be developed by an appropriate method such as a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, an extrusion method, a curtain coating method, and a spray coating method. This can be performed by flowing the liquid on the gas barrier layer to form a spread layer in the form of a sheet. The film is formed by heat treatment, light irradiation treatment or curing treatment as necessary.
[0032]
The thickness of the base material layer can be appropriately determined at a thickness of 100 μm or more according to the intended use of the antireflection resin sheet. In general, the thickness is 1 mm or less, preferably 900 μm or less, particularly 800 μm or less from the viewpoint of taking advantage of sheet properties such as rigidity, flexibility, and thinness and lightness. For optical applications, a thickness of 200 μm to 500 μm is often advantageous.
[0033]
In the present invention, as a material for forming the gas barrier layer, a material having an excellent permeation blocking ability for a target gas such as water vapor or oxygen gas, and particularly having a small oxygen permeation coefficient is used. For example, polyvinyl alcohol, partially saponified products thereof, vinyl alcohol polymers such as ethylene / vinyl alcohol copolymer, polyacrylonitrile, polyvinylidene chloride and the like can be mentioned. Vinyl alcohol-based polymers are particularly preferred from the viewpoints of high gas barrier properties, diffusibility of water or uniformity of water absorption.
[0034]
The method for forming the gas barrier layer is not particularly limited, and an appropriate method can be adopted. Further, the thickness of the gas barrier layer is 15 μm or less, preferably 13 μm or less, more preferably 2 μm or less in terms of transparency, prevention of coloring, functionality such as gas barrier properties, thinning, and flexibility of the obtained epoxy resin sheet. The thickness is preferably 10 μm, particularly preferably 3 μm to 5 μm. When the thickness of the gas barrier layer is 2 μm or more, a sufficient gas barrier function can be provided, and when the thickness is 10 μm or less, the yellowness index (YI value) of the liquid crystal cell substrate decreases.
[0035]
Examples of the material for forming the hard coat layer in the present invention include urethane resins, acrylic resins, polyester resins, polyvinyl alcohol resins such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer, vinyl chloride resins and vinylidene chloride resins. Resins.
[0036]
In addition, polyarylate resin, sulfone resin, amide resin, imide resin, polyether sulfone resin, polyetherimide resin, polycarbonate resin, silicone resin, fluorine resin, polyolefin resin, styrene resin Also, a vinylpyrrolidone-based resin, a cellulose-based resin, an acrylonitrile-based resin, and the like can be used for forming the resin layer. In forming the resin layer, a blend of two or more kinds of appropriate resins can be used.
[0037]
Among these resins, urethane-based resins are preferable, and urethane acrylate is particularly preferably used, from the viewpoints of optical properties, and easy-to-peel off property to a support described later, particularly easy-to-peel property to a stainless steel-based support, and hard coat property. Can be Among them, urethane acrylate represented by the following chemical formula (Formula 1) is preferable.
Embedded image

[0038]
In the present invention, an antiglare function is imparted by the hard coat layer having an uneven surface structure, and a light diffusion function is imparted by including transparent particles in the hard coat layer. It is considered that by covering the surface of the coat layer with the low refractive index layer, the synergistic effects of these provide an antiglare function, a light diffusion function, and an antireflection function that are superior to the case of using each alone.
[0039]
In the present invention, the surface roughness (Ra) of the hard coat layer having an uneven structure is preferably from 80 nm to 500 nm, and more preferably from 100 nm to 400 nm. When the surface roughness (Ra) of the hard coat layer having the uneven structure is smaller than 80 nm or larger than 500 nm, a sufficient antiglare function cannot be provided. The surface roughness in the present invention is "arithmetic mean roughness Ra" described in JIS B0601.
[0040]
The peak-to-valley interval of the hard coat layer having the above-mentioned surface unevenness is preferably 20 μm to 80 μm, and more preferably 30 μm to 70 μm. If the peak-to-valley spacing is smaller than 20 μm or larger than 80 μm, a sufficient antiglare function cannot be provided. The valley interval in the present invention is JIS
B 0601 means “average interval Sm of unevenness”.
[0041]
Examples of the transparent particles include inorganic materials such as glass and silica, acrylic resins, polyester resins, epoxy resins, melamine resins, urethane resins, polycarbonate resins, polystyrene resins, silicone resins, benzoguanamine, and melamine. -An organic material such as a benzoguanamine condensate or a benzoguanamine-formaldehyde condensate may be used. More preferably, spherical particles having a difference in refractive index from the resin forming the hard coat layer in the range of 0.03 to 0.10. When the refractive index difference is smaller than 0.03 or larger than 0.10, a sufficient light diffusion function cannot be provided.
[0042]
The transparent particles preferably have a particle diameter substantially in the range of 0.3 μm to 30 μm. If the particle diameter is 0.3 μm or more, the light diffusibility becomes good, and if it is 30 μm or less, the light diffusivity becomes uniform.
[0043]
The volume ratio of the transparent particles to the hard coat layer is preferably 1 to 50%. The volume ratio can be calculated by (volume of transparent particles / volume of hard coat layer) × 100. Here, the volume of the hard coat layer refers to the volume of the hard coat layer containing transparent particles. When the volume ratio of the transparent particles to the hard coat layer is smaller than 1% or larger than 50%, a sufficient light diffusion function cannot be provided.
[0044]
The method for forming the hard coat layer is not particularly limited, and an appropriate method can be adopted. For example, a coating solution is prepared by adding transparent particles to a resin solution for forming a hard coat layer, and the coating solution is prepared by a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, an extrusion method, a curtain coating method, a spray coating method. A hard coat layer containing transparent particles can be formed by coating and drying after an appropriate method such as a coating method. After drying, a film is formed by heat treatment, light irradiation treatment or curing treatment as necessary.
[0045]
The thickness of the hard coat layer can be determined as appropriate, but is generally 1 μm to 10 μm, preferably 8 μm or less, particularly from the viewpoint of easy peeling during production and preventing cracking during peeling. Preferably it is 2 μm to 5 μm.
[0046]
When the uneven structure is formed on the surface of the hard coat layer, the method is not particularly limited, but the concave portion of the support having the concave portion formed on the surface is transferred to the hard coat layer surface, and the hard coat layer surface is formed. It is preferable to form an uneven structure. The support is usually in the form of a belt or a plate, and specific examples include an endless belt for casting and a flat mold for casting.
[0047]
In order to form a predetermined uneven structure on the hard coat layer, the surface roughness (Ra) of the support is preferably 80 nm to 500 nm, more preferably 100 μm to 400 μm. The interval between peaks and valleys of the irregularities formed on the support is preferably 20 μm to 80 μm, and more preferably 30 μm to 70 μm.
[0048]
In the casting method, a hard coat layer-forming resin solution containing transparent particles was applied onto a support having irregularities formed thereon, and then dried to form a hard coat layer, and a gas barrier layer and a substrate layer were laminated. By peeling these laminates from the support later, a liquid crystal cell substrate having a concavo-convex structure formed on the hard coat layer can be obtained. Further, by laminating another hard coat layer on the outermost layer opposite to the support side, a liquid crystal cell substrate having two hard coat layers can be obtained. In this case, the hard coat layer does not have an uneven structure.
[0049]
In the casting method, first, a hard coat layer forming resin solution is applied to a mold having an uneven portion and a mold having a pure surface, and then dried to form a hard coat layer. Next, after applying the gas barrier layer forming resin-containing liquid to the mold having the unevenness and drying it to form the gas barrier layer, the two molds are put through the spacer or the sealing material with the resin application surfaces facing each other. Perform typesetting. Next, a base layer-forming resin-containing liquid is injected into the gap and then cured to form a base layer. The base layer is peeled off from the two molds to transfer the concave portions formed on the support onto the hard coat layer. A liquid crystal cell substrate having an uneven structure can be obtained. Further, the gas barrier layer may be formed after applying a hard coat layer forming resin liquid on a hard coat layer formed in a mold having a solid surface.
[0050]
Also in the casting method, the surface roughness (Ra) of the mold on which the irregularities are formed is preferably 80 nm to 500 nm, and more preferably 100 μm to 400 μm. The interval between the peaks and valleys of the irregularities formed in the mold is preferably 20 μm to 80 μm, and more preferably 30 μm to 70 μm.
[0051]
In the present invention, examples of the material for forming the low refractive index layer made of a material having a lower refractive index than the resin for forming the hard coat layer include a resin material such as an ultraviolet curable acrylic resin, and inorganic fine particles such as colloidal silica in the resin. And sol-gel materials using metal alkoxides such as tetraethoxysilane and titanium tetraethoxide. In addition, a fluorine group-containing compound is used for each material in order to impart surface contamination resistance. From the viewpoint of scratch resistance, a low refractive index layer material having a large content of an inorganic component tends to be excellent, and a sol-gel material is particularly preferable.
[0052]
Examples of the sol-gel material containing a fluorine group include perfluoroalkylalkoxysilane. Examples of the perfluoroalkylalkoxysilane include, for example, a compound represented by the general formula (1): CF ₃ (CF ₂ ) nCH ₂ CH ₂ Si (OR) ₃ (wherein, R represents an alkyl group having 1 to 5 carbon atoms; n is an integer of 0 to 12). Specifically, for example, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane Ethoxysilane and the like can be mentioned. Of these, compounds wherein n is 2 to 6 are preferred.
[0053]
By using a fluorine-containing compound as the low refractive index material and using a compound having a positively charged functional group and / or a positively chargeable functional group, the outermost surface of the antireflection layer is apparently electrically neutral. You may make it. The charge on the outermost surface of the anti-reflection layer is reduced, and the problem of adhesion of dust, dust, and the like, and the problem of removal can be solved.
[0054]
Various compounds can be used as the compound having a positively charged functional group and / or a compound having a positively chargeable functional group. Examples of the functional group include a functional group containing a nitrogen atom such as an amino group and an ammonium base. And a functional group containing a sulfur atom such as a sulfonium group, and a functional group containing a phosphorus atom such as a phosphoric acid group. Among them, a functional group containing a nitrogen atom, such as an amino group or an ammonium base, is preferable because it is excellent in preventing adhesion of dust and dirt and wiping.
[0055]
Examples of the compound having a functional group containing a nitrogen atom include polyethyleneimine and quaternary ammonium salts such as tetrabutylammonium bromide and tetraammonium chloride. Particularly, as the silane compound, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) Silane coupling agents such as -γ-aminopropyltriethoxysilane and N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane.
[0056]
The compounding ratio of the fluorine-containing compound and the compound having a functional group is not particularly limited, but the compounding ratio of the compound having a functional group is 0.1 to 1.5 mol per 1 mol of the compound having a fluorine group. Parts, more preferably 0.5 to 1 part by mole. If the compounding ratio of the compound having a functional group is small, the antifouling property relating to the property of repelling liquid is good, but it is difficult to sufficiently exhibit the anti-adhesion property of dust and dirt, etc. Although the property of preventing adhesion of dust and the like and the property of removing the dust are good, the antifouling property tends to decrease. The low-refractive-index layer-forming material can be prepared as a coating liquid in which the above-mentioned compounds are mixed so as to have the above-mentioned compounding ratio.
[0057]
Further, a sol in which silica, alumina, titania, zirconia, magnesium fluoride, ceria, or the like is dispersed in an alcohol solvent may be added to the low refractive index layer forming material. In addition, additives such as metal salts and metal compounds can be appropriately compounded.
[0058]
The refractive index of the low refractive index layer is lower than the refractive index of the hard coat layer. Further, it is preferable to adjust the refractive index to be lower than the refractive index of the base material layer. The refractive index of the low refractive index layer is preferably from 1.35 to 1.50.
[0059]
The method for forming the low refractive index layer is not particularly limited, and the low refractive index layer is formed on the hard coat layer by an appropriate method. For example, it can be formed by an appropriate method such as a doctor blade method, a gravure roll coater method, a dipping method, and an evaporation method. The thickness of the low refractive index layer is not particularly limited, and is usually about 80 nm to 150 nm on average.
[0060]
FIG. 1 shows an example of the production of the antireflection resin sheet according to the present invention by the casting method, and FIG. 2 shows an example of the production by the casting method.
[0061]
First, in the casting method, as shown in FIG. 2, a hard coat layer forming resin solution is applied to a mold (13) having a solid surface and then dried to form a hard coat layer. A hard coat layer forming resin solution is applied to the surface processing mold (14) and then dried to form a hard coat layer. Further, a gas barrier layer forming resin containing liquid is applied and then dried to form a gas barrier layer. Thereafter, the two molds are assembled with the resin application surfaces facing each other via the spacer (16) and the sealing material (15). Next, after injecting a liquid containing a base layer forming resin into the gap and curing the liquid, a base layer is formed, and after separating from two molds, a low refractive index layer is formed as the outermost layer, thereby providing the present invention. Can be obtained. In this case, the hard coat layer containing the transparent particles can be formed by including the transparent particles in the resin solution for forming the hard coat layer and drying after coating.
[0062]
In the manufacturing process illustrated in FIG. 1, an antireflection resin sheet is continuously manufactured by a casting method using an endless belt as a support.
[0063]
In the casting method illustrated in FIG. 1, the support made of the endless belt (1) is, for example, 0.1 to 50 m / min, preferably 0.2 m / min, via a driving drum (4) and a driven drum (5). While traveling at a constant speed of up to 5 m / min, a resin solution for forming a hard coat layer is applied from the die (7) and a resin-containing solution for forming a gas barrier layer is applied from the die (9) and dried. The coatings (10) and (11) are cured by light irradiation or the like. In the illustrated example, a heating device (3) and a UV curing device (8) are provided. Further, the endless belt (1) is formed with an uneven portion, and the surface roughness (Ra) and the interval between peaks and valleys (Sm) of the unevenness are as described above.
[0064]
Further, the hard coat layer containing the transparent particles can be formed by allowing the resin solution for forming the hard coat layer to contain the transparent particles and drying after the application.
[0065]
Next, the base layer-forming resin-containing liquid is applied onto the coatings (10) and (11) via the die (2), developed into a sheet shape, and completely cured by heating or light irradiation to form the coating ( 6). In the illustrated example, a heating device (3) is provided, and the heating method is performed by hot air, an infrared heater, or the like, and these may be used in combination. The hot air velocity is usually 0.1 to 5 m / sec, but in the case of heating a thermoplastic or thermosetting resin-containing liquid, it is preferably 0.2 to 1 m / sec.
[0066]
The heating device (3) is preferably divided into about 10 zones in order to control the viscosity change caused by the viscosity reduction due to the temperature-dependent curing reaction of the resin-containing liquid. In each zone, heating can be performed on the upper surface, the lower surface, or both surfaces of the endless belt. The heating temperature is preferably from 30 to 250C. The heating temperature accuracy is preferably ± 0.5 ° C./cm or less, and more preferably ± 0.1 ° C./cm or less. When the heating temperature is lower than 30 ° C., the resin for forming the base material layer is hardly cured. If the heating temperature exceeds 250 ° C., the viscosity of the base layer-forming resin-containing liquid decreases, so that the accuracy of the thickness of the resin sheet deteriorates. If the heating temperature accuracy is larger than ± 0.5 ° C./cm, the accuracy of the thickness of the resin sheet deteriorates, and the appearance is likely to be poor.
[0067]
The temperature of the die (2) for discharging the base layer-forming resin-containing liquid is preferably from 10 to 40C, more preferably from 20 to 30C. The temperature accuracy of the die is preferably ± 0.5 ° C. or less, more preferably ± 0.1 ° C. or less. If the temperature of the die is lower than 10 ° C., the viscosity of the base layer-forming resin-containing liquid increases, which causes a problem in operability. If the temperature exceeds 40 ° C., the curing of the resin for forming the base layer proceeds in the die, so that the coating becomes difficult. If the temperature accuracy of the die is larger than ± 0.5 ° C., the accuracy of the thickness of the resin sheet is deteriorated, and the appearance is likely to be poor.
[0068]
The viscosity of the base layer forming resin-containing liquid to be discharged is preferably from 0.1 Pa · s to 50 Pa · s, and when performing the extrusion coating, it is preferably from 15 Pa · s to 30 Pa · s. If the viscosity of the resin-containing liquid is less than 0.1 Pa · s, the accuracy of the thickness of the resin sheet becomes poor. If the viscosity of the resin-containing liquid exceeds 50 Pa · s, the operability becomes poor.
[0069]
As a method for applying the liquid containing the base layer-forming resin, a curtain coat, an extrusion coat, a roll coat and the like are preferable, and an extrusion coat is particularly preferable.
[0070]
A guide roll is provided on the back surface of the endless belt of the heating device, and the horizontal level can be adjusted by a horizontal level sensor. The horizontal level of the support is preferably 1 mm / (5 × effective width) mm or less, more preferably 1 mm / (40 × effective width) mm or less. When the horizontal level is larger than 1 mm / (5 × effective width) mm, the accuracy of the thickness of the resin sheet becomes poor.
[0071]
In order to obtain a resin sheet having two hard coat layers by the casting method, a hard coat layer forming resin solution is applied to the outermost layer opposite to the endless belt and dried, or if necessary, heated or irradiated with light. Curing treatment. In this case, a second hard coat layer can be formed by a spin coating method, a single-plate die coater, or the like after peeling the laminate including the first hard coat layer, the gas barrier layer, and the base material layer from the endless belt 1. Further, by including the transparent particles in the resin solution for forming the hard coat layer, a hard coat layer containing the transparent particles can be formed.
[0072]
Further, a weir for preventing liquid flow may be provided on both sides of the support with a heat-resistant resin. Specifically, polyethylene terephthalate or the like is preferably used.
[0073]
When collecting the resin sheet from the support, a peeling unit can be used as necessary. Further, it is preferable that such recovery is performed in a high-temperature atmosphere at a temperature equal to or higher than the glass transition point for preventing cracks. Further, the formed resin sheet in a continuous state can be collected by cutting into appropriate dimensions through appropriate cutting means such as a laser beam, an ultrasonic cutter, dicing, or a water jet. According to the casting method, the production speed can be easily controlled by adjusting the moving speed of the spreading layer through the support, and the thickness of the resin sheet obtained by adjusting the moving speed and the spreading amount can be easily controlled. can do. The antireflection sheet of the present invention can be obtained by forming the low refractive index layer on the hard coat layer of the resin sheet recovered in this manner by an appropriate method.
[0074]
3 to 5 show configuration examples of a liquid crystal display device equipped with the liquid crystal cell substrate (antireflection resin sheet) 31 of the present invention. In the figure, 17 is a low refractive index layer, 118 is a hard coat layer containing transparent particles, 19 is a gas barrier layer, and 20 is a base material layer. Reference numeral 18 denotes a hard coat layer containing no transparent particles.
[0075]
In general, a liquid crystal display device is formed by appropriately assembling components such as a polarizing plate, a liquid crystal cell, a reflector or a backlight, and optical components as necessary, and incorporating a driving circuit. In the present invention, there is no particular limitation except that the above-described liquid crystal cell substrate is used, and it can be formed according to a conventional method. Therefore, when the liquid crystal display device of the present invention is formed, for example, a light diffusion plate, an anti-glare layer, an antireflection film, a protective layer, a protective plate provided on the viewing-side polarizing plate, or between the liquid crystal cell and the viewing-side polarizing plate. Appropriate optical components such as a compensating retardation plate to be provided can be appropriately combined with the liquid crystal cell substrate. In the present invention, in order to improve the visibility, it is preferable to dispose the liquid crystal cell substrate on the viewing side where the transparent particle-containing hard coat layer is closest to the liquid crystal layer.
[0076]
Next, an organic electroluminescence device (organic EL display device) will be described. In general, in an organic EL display device, a luminous body (organic electroluminescent luminous body) is formed by sequentially laminating a transparent electrode, an organic luminescent layer, and a metal electrode on a transparent substrate. Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like, and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a configuration having various combinations such as a stacked body of such a light emitting layer and an electron injection layer made of a perylene derivative, or a stacked body of a hole injection layer, a light emitting layer, and an electron injection layer thereof is known. Has been.
[0077]
In an organic EL display device, holes and electrons are injected into an organic light emitting layer by applying a voltage to a transparent electrode and a metal electrode, and energy generated by recombination of these holes and electrons excites a fluorescent substance. Then, light is emitted on the principle that the excited fluorescent substance emits light when returning to the ground state. The mechanism of recombination on the way is the same as that of a general diode, and as can be expected from this, the current and the emission intensity show strong nonlinearity accompanied by rectification with respect to the applied voltage.
[0078]
In an organic EL display device, at least one of the electrodes must be transparent in order to extract light emitted from the organic light emitting layer. Usually, a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. Used as On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and usually a metal electrode such as Mg-Ag or Al-Li is used.
[0079]
In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. Therefore, the organic light emitting layer transmits light almost completely, similarly to the transparent electrode. As a result, when light is incident from the surface of the transparent substrate during non-light emission, light transmitted through the transparent electrode and the organic light-emitting layer and reflected by the metal electrode again exits to the surface side of the transparent substrate, and when viewed from the outside, The display surface of the organic EL display device looks like a mirror surface.
[0080]
In an organic EL display device including an organic electroluminescent luminous body having a transparent electrode on the front side of an organic luminescent layer that emits light by applying a voltage and a metal electrode on the back side of the organic luminescent layer, the surface of the transparent electrode A polarizing plate can be provided on the side, and a retardation plate can be provided between the transparent electrode and the polarizing plate.
[0081]
Since the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarizing function. In particular, if the retardation plate is formed of a 波長 wavelength plate and the angle between the polarization directions of the polarizing plate and the retardation plate is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded. .
[0082]
That is, as for the external light incident on the organic EL display device, only the linearly polarized light component is transmitted by the polarizing plate. The linearly polarized light is generally converted into elliptically polarized light by the phase difference plate, but becomes a circularly polarized light particularly when the phase difference plate is a 波長 wavelength plate and the angle between the polarization directions of the polarizing plate and the phase difference plate is π / 4. .
[0083]
This circularly polarized light transmits through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, passes through the organic thin film, the transparent electrode, and the transparent substrate again, and becomes linearly polarized light again by the phase difference plate. The linearly polarized light cannot pass through the polarizing plate because it is orthogonal to the polarizing direction of the polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.
[0084]
【Example】
Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In each example, parts and percentages are by weight unless otherwise specified. The measurement of the refractive index of the present invention was performed using an Abbe refractometer manufactured by Atago Co., Ltd.
[0085]
Example 1
(Preparation of low refractive index layer forming agent)
1 mol part of tridecafluorohexyltriethoxysilane was mixed with 1 mol part of γ-aminopropyltrimethoxysilane, and the solid component was adjusted to about 1% with an ethanol solvent. A forming agent was prepared.
[0086]
(Preparation of hard coat layer forming resin liquid)
450 parts by weight of toluene is mixed with 100 parts by weight of NK Oligo UN-01 (manufactured by Shin-Nakamura Chemical; solid content: 85%), 3 parts by weight of Irgacure # 184 (manufactured by Ciba Specialty Chemicals), which is a UV-curable resin, and stirred. Thus, a hard coat layer forming resin solution having a resin solid content of 16% was obtained.
[0087]
(Preparation of transparent particle-containing hard coat layer forming resin liquid)
100 parts by weight of UV curing resin NK Oligo UN-01 (manufactured by Shin-Nakamura Chemical; solid content: 85%), 3 parts by weight of Irgacure # 184 (manufactured by Ciba Specialty Chemicals), and average particle size of 1.8 μm To 28 parts by weight of silica particles (refractive index: 1.46), 450 parts by weight of toluene were mixed and stirred to obtain a transparent particle-containing hard coat layer forming resin solution having a resin solid content concentration of 20%.
[0088]
(Preparation of base layer-forming resin liquid)
400 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate represented by the chemical formula (Chem. 2) and 500 parts by weight of methylhexahydrophthalic anhydride represented by the chemical formula (Chem. 3) 15 parts by weight of tetra-n-butylphosphonium o, o-diethylphosphorodithioate represented by the chemical formula of 4), 9 parts by weight of glycerin, and 1 part by weight of a surfactant are mixed and stirred to form a liquid containing the base layer-forming resin. Obtained.
[0089]
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[0090]
(Production of liquid crystal cell substrate)
Next, a liquid crystal cell substrate was manufactured by a casting method using the mold shown in FIG. The manufacturing method will be described with reference to FIGS.
[0091]
First, as a mold, a solid mold (13) having a size of 450 mm × 450 mm and a surface roughness Ra of 5 nm was used. The other was a surface processing die (14) having a surface processed to 450 mm × 450 mm, a surface roughness Ra = 100 nm, and a peak-to-valley interval of 30 μm. First, a resin solution for forming a hard coat layer is applied to the processed surface of a solid mold (13) by spin coating, and after drying toluene, irradiation with UV light (center wavelength: 254 nm, integrated light amount: 2000 mJ / cm ² ) is performed. A 2 μm hard coat layer (18) was formed. Next, a resin solution for forming a hard coat layer containing transparent particles is applied to the processing surface of the other surface processing die (14) by spin coating, and toluene is dried, followed by UV irradiation (center wavelength: 254 nm, integrated light amount: 2000 mJ / cm ² ) to form a hard coat layer (118) having a thickness of 2 μm. The refractive index of the hard coat layer was 1.51.
[0092]
Next, a 5.5% by weight aqueous solution of polyvinyl alcohol (degree of polymerization: 1,800) is applied on the hard coat layer (118) formed on the surface processing mold (14) by a spin coating method, and then dried and cured. Then, a gas barrier layer (19) having a thickness of 3.7 μm was formed.
[0093]
Next, with the resin forming surfaces of the two molds facing each other, as shown in FIG. 2, the gap width was set to 400 μm via the gap adjusting spacer (16) and the sealing agent (15). The casting mold was assembled so that The base layer-containing resin-containing liquid prepared above was injected into the gap, and cured at 120 ° C. × 30 minutes + 180 ° C. × 1 hour. Thereafter, the two molds are split, and at the same time, the interface between the resin layer and the mold is peeled to take out the resin sheet, and then the low refractive index layer forming agent prepared above is formed on the hard coat layer (118). Was applied so as to have an average thickness of about 100 nm upon drying and curing to form a low refractive index layer (17), thereby obtaining a liquid crystal cell substrate <a> comprising an antireflection resin sheet (31). The drying and curing conditions at this time were 90 ° C. and 40 hours. The refractive index of the low refractive index layer was 1.40.
[0094]
In the obtained liquid crystal cell substrate <a>, the surface on which the concave and convex portions of the mold were transferred had a surface roughness Ra of 100 nm, a peak-to-valley interval of 45 μm, and the other had a surface roughness Ra of 5 nm. The average thickness of the liquid crystal cell substrate <a> was 400 μm, and the standard deviation of the thickness was 9 μm.
[0095]
Next, the other liquid crystal cell substrate with the liquid crystal interposed was produced as follows. First, the resin solution for forming a hard coat layer was applied to two molds having a solid surface and dried to form a hard coat layer (18). Next, the resin forming surfaces of the two molds are opposed to each other, and as shown in FIG. 2, through a gap adjusting spacer and a sealing agent, the width of the gap is set to 400 μm. The mold was assembled.
[0096]
Then, a black pigment-containing base layer-forming resin-containing liquid in which the black pigment Mitsubishi carbon black MA100 is dispersed at a ratio of the base layer-forming resin-containing liquid: MA100 = 10: 1 (weight ratio) is injected into the gap. After curing at 120 ° C. × 30 minutes + 180 ° C. × 1 hour, the liquid crystal cell substrate <b> was taken out from the mold. The obtained liquid crystal cell substrate <b> had a surface roughness Ra of 4 nm on both sides, an average thickness of 400 μm, and a standard deviation of the thickness of 8 μm.
[0097]
(Production of liquid crystal cell)
After the obtained liquid crystal cell substrates <a> and <b> were cut into a predetermined shape, plasma treatment was performed in an Ar atmosphere to form an indium tin oxide (ITO) thin film by sputtering. Next, an ITO thin film (21) was formed on the hard coat layer (18) of the liquid crystal cell substrate <a> and on one of the hard coat layers of the resin sheet <b>.
[0098]
After that, the ITO thin film (21) of the liquid crystal cell substrate <a> is divided into two parts, and a pair of the substrates is opposed to the ITO thin film (21) so that the rubbing directions of the rubbing films (22) are orthogonal to each other. After disposing a gap adjusting material made of glass beads, it was fixed with a sealing material. Thereafter, 10 parts of trimethylpropane triacrylate (TMPTA), 10 parts of 2-hydroxyethyl acrylate (HEA), and 25 parts of an acrylic oligomer (TOA Gosei Chemical "M-1200"), and "Darocur" manufactured by Merck as a photocuring initiator. Then, 0.5 part of "-1173" and 50 parts of liquid crystal "E7" manufactured by BDH as a liquid crystal were mixed, and a mixed solution uniformly dissolved was injected. Thereafter, ultraviolet light was irradiated from the liquid crystal cell substrate <a> side of the cell to produce the liquid crystal cell illustrated in FIG.
[0099]
Example 2
A liquid crystal cell substrate <a ′> was formed in the same manner as in Example 1 except that the two layers were coated with the transparent particle-containing hard coat layer forming resin solution so that the two hard coat layers contained transparent particles. . Thereafter, in the same manner as in Example 1, the liquid crystal cell was combined with the liquid crystal cell substrate <b> to produce the liquid crystal cell illustrated in FIG.
[0100]
Example 3
A liquid crystal cell substrate was manufactured by a casting method using the apparatus shown in FIG. First, the resin solution for forming a transparent particle-containing hard coat layer prepared in Example 1 was discharged from a die (7), and the running speed was set to 0. 1 on a stainless steel endless belt (1) (surface roughness Ra = 100 nm, peak-valley interval 40 μm). A hard coat layer (11) having a film thickness of 5 μm and a width of 500 mm was applied by casting at a rate of 2 m / min, volatilizing the toluene, and curing with a UV curing device (8) (center wavelength: 254 nm, cumulative light amount: 2000 mJ / cm ² ). Got.
[0101]
Subsequently, a 5.5% by weight aqueous solution of polyvinylyl alcohol was discharged from the die (9), cast and applied on the hard coat layer, and dried by heating (60 ° C. × 10 minutes) to obtain a film having a thickness of 4 μm and a width of 4 μm. A 450 mm gas barrier layer (10) was obtained.
[0102]
A heat-resistant PET base tape (MT-3155: manufactured by Nitto Denko Corporation) having a width of 40 mm was attached to both ends of the obtained hard coat layer and gas barrier layer, and a base layer-forming resin-containing liquid (20 Pa · s) similar to that of Example 1 was used. , 25 ° C.) is discharged from the die 2 and cast on the surface of the gas barrier layer with a coating width of 430 mm, and heated by a heating device (3) at 90 ° C. × 5 minutes, 120 ° C. × 5 minutes, 140 ° C. A base material layer (6) is formed by curing in × 15 minutes, and peeled between a stainless steel endless belt and a hard coat layer on a drum (5) controlled at 130 ° C. to obtain a 430 mm wide liquid crystal cell substrate. Was. The horizontal level of the support in the heating section was 200 μm / 1000 mm, and hot air was heated from above and below the support to obtain a temperature accuracy of 0.4 ° C./cm. The low-refractive-index layer forming agent prepared in Example 1 was applied on the hard coat layer under the same conditions as in Example 1 to form a low-refractive-index layer, and a liquid crystal cell substrate made of an antireflection resin sheet <c > Was obtained.
[0103]
The obtained liquid crystal cell substrate <c> was cut at 490 mm intervals in the flow direction to obtain a size of 490 mm × 490 mm. The average of the thickness of the obtained liquid crystal cell substrate <c> was 400 μm, and the standard deviation was 7 μm. The average value and the standard deviation of the thickness were determined by measuring 60 points in a plane of 480 mm × 480 mm. The surface roughness was Ra = 0.2 nm on the substrate layer side and Ra = 100 nm on the low refractive index layer side. In addition, the surface roughness is an average value measured at 10 points in a plane of 480 mm × 480 mm.
[0104]
Subsequently, an ITO thin film was formed on the hard coat layer side of the liquid crystal cell substrate <c>, and combined with the liquid crystal cell substrate <b> in the same manner as in Example 1 to produce the liquid crystal cell illustrated in FIG.
[0105]
Comparative Example 1
A liquid crystal cell substrate <d> was produced in the same manner as in Example 1, except that the low refractive index layer was not formed on the hard coat layer. Next, in the same manner as in Example 1, the liquid crystal cell was combined with the liquid crystal cell substrate <b> to produce the liquid crystal cell illustrated in FIG.
[0106]
(Evaluation test)
A liquid crystal display device was assembled using the liquid crystal cells manufactured in Examples 1 to 3 and Comparative Example 1, and a ring-shaped illumination device was irradiated at an angle of 20 ° in a dark room, and black display was performed in a state where a voltage was applied to the liquid crystal display device. Was examined, and the display quality of white display was measured in a state where no voltage was applied.
[0107]
(Reflectance)
After roughening the outermost layer of the anti-reflection resin sheet on the side opposite to the low refractive index layer using sandpaper, black acrylic lacquer is applied to eliminate the reflected light on the back side of the anti-reflection layer. The total reflectance was measured using a spectrophotometer equipped with a tilting integrating sphere (UV-2400 manufactured by Shimadzu Corporation). In measuring the reflectance, the reflectance Y obtained by correcting the luminosity of the C light source from the above-mentioned spectral reflectance based on the CIE1931XYZ color system was adopted.
[0108]
In Examples 1 to 3, the display quality was good for both black display and white display. On the other hand, in Comparative Example 1, in white display, glare was observed, which was considered to be caused by the reflection of illumination on the liquid crystal surface. Further, the reflectance of the resin sheets obtained in Examples 1 to 3 was 2.6, but the reflectance in Comparative Example 1 was 3.2%. From the above results, when the low refractive index layer was provided, reflection was suppressed.
[0109]
【The invention's effect】
As described above, according to the present invention, the base material layer, the gas barrier layer, and the hard coat layer having the uneven structure on the outer surface are laminated in this order, and the hard coat layer is more refracted on the hard coat layer than the hard coat layer forming resin. The low-refractive-index layer made of a low-refractive-index material has an anti-glare function that prevents the so-called ghost phenomenon in which the external environment such as illumination light such as fluorescent lamps and sunlight and the keyboard is reflected on the screen. In addition, the hard coat layer having the concavo-convex structure contains transparent particles, and thus has a light diffusion function of preventing glare caused by external light such as illumination light or a backlight built in a liquid crystal display device, and is thin and lightweight. An anti-reflection resin sheet is obtained.
[0110]
By using this antireflection resin sheet for a substrate for an image display device such as a liquid crystal cell substrate or a substrate for an organic EL display device, the substrate becomes thinner, lighter and more durable than a glass-based substrate. Also, by providing both the anti-glare function and the light diffusion function to the liquid crystal cell substrate, there is no need to attach an anti-glare sheet or a light diffusion sheet to the viewing side of the liquid crystal cell. As a result, the liquid crystal cell becomes thinner and lighter. Becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a method for manufacturing a liquid crystal cell substrate by a casting method.
FIG. 2 is a diagram illustrating an example of a method for manufacturing a liquid crystal cell substrate by a casting method.
FIG. 3 is a schematic cross-sectional view illustrating a configuration of a liquid crystal cell of Example 1.
FIG. 4 is a schematic cross-sectional view illustrating a configuration of a liquid crystal cell of Example 2.
FIG. 5 is a schematic cross-sectional view illustrating a configuration of a liquid crystal cell of Example 3.
FIG. 6 is a schematic cross-sectional view illustrating a configuration of a liquid crystal cell of Comparative Example 1.
[Explanation of symbols]
1: Endless belt (support)
2: die for coating base layer 3: heating device 4: driving drum 5: driven drum 6: base layer 7: die for coating hard coat layer 8: UV curing device 9: die for coating gas barrier layer 10: gas barrier layer 11 : Hard coat layer 12: Edge reinforcing tape 13: Solid surface metal mold 14: Surface processed metal mold 15: Sealing material 16: Spacer 17 for adjusting gap: Low refractive index layer 18: Hard coat layer 118: Transparent particles Hard coat layer 19: gas barrier layer 20: base material layer 21: ITO
22: rubbing film 23: liquid crystal 24: substrate layer 31 having black pigment: liquid crystal cell substrate (anti-reflection resin sheet)

Claims (13)

A substrate layer, a gas barrier layer, a hard coat layer having an uneven structure on the outer surface are laminated in this order, and a low refractive index made of a material having a lower refractive index than the hard coat layer forming resin on the hard coat layer An anti-reflection resin sheet having a layer formed thereon, wherein the hard coat layer having the uneven structure contains transparent particles. The anti-reflection resin sheet according to claim 1, wherein another hard coat layer is laminated on a side of the base layer opposite to the gas barrier layer. The anti-reflection resin sheet according to claim 2, wherein the hard coat layer laminated on the opposite side of the base layer from the gas barrier layer contains transparent particles. The antireflection resin sheet according to any one of claims 1 to 3, wherein the transparent particles are spherical particles having a refractive index difference of 0.03 to 0.10. The refractive index of the hard coat layer is 1.45 to 1.80, and the refractive index of the low refractive index layer is 1.35 to 1.50. An antireflection resin sheet according to any of the above items. The anti-reflection resin sheet according to any one of claims 1 to 5, wherein a surface roughness of the uneven structure is 80 nm to 500 nm. The anti-reflection resin sheet according to any one of claims 1 to 6, wherein an interval between peaks and valleys of the uneven structure is 20 µm to 80 µm. The anti-reflection resin sheet according to any one of claims 1 to 7, wherein the base layer is made of an epoxy resin. The anti-reflection resin sheet according to any one of claims 1 to 8, wherein the hard coat layer is made of a urethane resin. The anti-reflection resin sheet according to any one of claims 1 to 9, wherein the uneven structure is formed by transferring a concave portion formed on the surface of the support. A substrate for an image display device, comprising the antireflection resin sheet according to claim 1. An image display device using the image display device substrate according to claim 11. A substrate for a solar cell, comprising the antireflection resin sheet according to claim 1.

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