JP3874513B2 - Antireflection film and optical material - Google Patents

Description

前記一般式（３）において、Ｒ ^４ は水素原子又は低級アルキル基若しくはアリール基、Ｒ ^５ は低級アルキル基又はアリール基、Ｒ ^６ は炭素数１〜４の有機基、ＱはＣＨ _２ ＣＨ _２ ＣＨ _２ 又はＣＨ _２ ＣＨ _２ ＮＨＣＨ _２ ＣＨ _２ ＣＨ _２ 、ｍは１５〜３５の整数、ｎは２又は３である。
【０００７】
【発明の効果】
本発明によれば、汚染防止性や付着汚染の易拭取り除去性、耐擦傷性や撥水性等の性能に優れる、特に一般式（３）によるフルオロアミノシラン化合物等を用いるため、フッ素変性基が表面に効率よく配向して優れた撥水撥油性や汚染防止性、耐薬品性や潤滑性、離型性や耐擦傷性等の性能を示すと共に、二酸化ケイ素系無機層と強固に密着した汚染防止層を形成でき、手垢や指紋等の油系や水系等の汚染が付着しにくい上に、仮に汚染が付着しても目立ちにくくてティッシュペーパ等で容易に拭取り除去でき、その拭取り操作で傷付きにくくて、水滴等の付着は容易に振り落すことができ、しかもかかる性能を長期に持続する反射防止膜ないしその光学素材を得ることができる。
【０００８】
【発明の実施形態】
本発明の反射防止膜は、表面層として二酸化ケイ素系無機層を有する単層構造又は複層構造の無機系反射防止層の表面に、粘着テープの接着力が１．０Ｎ／20mm以下であるフッ素含有のシラン系硬化層からなる汚染防止層を有してなる。また本発明の光学素材は、前記反射防止膜を支持基材上に有してなる。
【０００９】
図１、図２に本発明による反射防止膜を例示した。また図３、図４に本発明による光学素材を例示した。３が無機系反射防止層１と汚染防止層２からなる反射防止膜、４が支持基材であり、１１，１２，１３は、無機系反射防止層１を形成する無機層である。なお５は、必要に応じて設けられるハードコート層である。
【００１０】
反射防止膜における無機系反射防止層は、実質的な反射防止機能を担う部分であり、本発明においては二酸化ケイ素系無機層を表面に有するものとする点を除いて、すなわち単層構造の場合には、図１に例示の如く二酸化ケイ素系無機層１３からなる無機系反射防止層１とする点を除いて、単層構造又は複層構造の適宜な構造とすることができる。
【００１１】
従って、例えばＡ．ＶＡＳＩＣＥＫ著、「OPUTICS OF THIN FILMS」Ｐ１５９〜２８３［北オランダパブリッシングカンパニ、アムステルダム（１９６０）：NORTH-HOLLAND PUBLISHING COMPANY, AMSTERDAM(1960)］や特開昭５８−４６３０１号公報、特開昭５９−４９５０１号公報や特開昭５９−５０４０１号公報、特開平１−２９４７０９号公報や特公平６−５３２４号公報などに基づく従来技術の如く、従来に準じた構造の反射防止層として形成することもできる。
【００１２】
無機系反射防止層の形成には、無機酸化物や無機ハロゲン化物やそれらの複合物等よりなる無機物を用いうる。その無機物の具体例としては、ＳiＯ₂やＺrＯ₂、Ａl₂Ｏ₃やＹ₂Ｏ₃、ＴiＯ₂の如き無機酸化物、ＭgＦ₂やＢaＦ₂、ＣaＦ₂やＬaＦ₂、ＬiＦやＮaＦ、ＳrＦ₂の如き無機ハロゲン化物などを代表例としてあげられる。
【００１３】
反射防止層を形成する無機物は、下記の形成方法などに応じてその１種又は２種以上が固体物、あるいはバインダ用ポリマー等と混合した分散液などの適宜な状態で用いられるが、その場合、無機物を３０重量％以上含有する組成で用いることが硬度や汚染防止性などの点より好ましい。なお前記のバインダ用ポリマーとしては、適宜なポリマーを用いることがでて特に限定はないが、硬度等の点よりはポリオルガノシロキサンを形成しうる各種の有機ケイ素化合物やその加水分解物などが好ましく用いうる。
【００１４】
無機系反射防止層の形成は、例えば真空蒸着法やスパッタリング法やイオンプレーティング法等で代表される各種のＰＶＤ（Phisical Vapor Deposition）法、あるいはスピンコート法や浸漬コート法、カーテンフローコート法やロールコート法、スプレーコート法や流し塗り法等で代表される流体塗布法などの適宜な薄膜形成法にて行うことができる。
【００１５】
前記したＰＶＤ法には、上記に例示したＳiＯ₂等の無機酸化物やＭgＦ₂等の無機ハロゲン化物などが好ましく用いられ、特に表面層となる二酸化ケイ素系無機層は、表面硬度の高さや汚染防止層の密着性などの点より、ＰＶＤ法により二酸化ケイ素を主成分として含有する層に形成したものが好ましい。
【００１６】
反射防止層は、反射防止効果等の点より複層構造とすることが好ましく、就中、表面層の二酸化ケイ素系無機層よりも高い屈折率の層を１層又は２層以上内在させた複層構造とすることが好ましい。その場合、各層の厚さや屈折率の設定等については、上記したＡ．ＶＡＳＩＣＥＫ著、「OPUTICS OF THIN FILMS」などの公知技術の如く、従来に準じることができる。
【００１７】
また反射防止層には、帯電によるゴミ等の付着を防止するために静電気の除去効果や電磁波のシールド効果も発揮する導電層を含ませてもよい。かかる導電層は、例えば金や銀やアルミニウム等の金属薄膜、酸化スズや酸化インジウムやそれらの混合物（ＩＴＯ）等の無機酸化物薄膜などからなる透明導電膜として形成される。可視領域では、光の吸収が極めて少ない無機酸化物系の透明導電膜が特に好ましい。
【００１８】
無機系反射防止層表面の二酸化ケイ素系無機層に付設される汚染防止層は、粘着テープの接着力が１．０Ｎ／20mm以下であるフッ素含有のシラン系硬化層にて形成される。粘着テープの接着力が１．０Ｎ／20mmを超えるシラン系硬化層では、汚染防止性に乏しくて、特に手垢や指紋等の人体的汚染が付着しやすく、また汚染の拭取り除去性に乏しくなる。
【００１９】
なお前記の接着力は、ＪＩＳ
Ｃ ２３３８（電気絶縁用ポリエステル粘着テープ）又はＣＥＳ
Ｍ ５０２３−６（ポリエステルフィルム粘着テープ）で品質が規定された、ポリエステルフィルムにアクリル系粘着層を設けた粘着力２．０Ｎ／10mm以上の粘着テープを、常温で汚染防止層（シラン系硬化層）に圧着し、それを剥離速度３００mm／分の条件で１８０度ピールした場合の値に基づく。
【００２０】
フッ素変性基が表面に効率よく配向し、優れた撥水撥油性や汚染防止性、耐薬品性や潤滑性、離型性や耐擦傷性等を発揮して二酸化ケイ素系無機層と強固に密着した汚染防止層の安定した形成性などの点より好ましく用いうるシラン系化合物としては、前記の一般式（３）で表されるフルオロアミノシラン化合物又は／及びその部分加水分解縮合物があげられる。
【００２１】
前記したフルオロアミノシラン化合物又は／及びその部分加水分解縮合物によれば、水分の存在下に加水分解して硬化し、従って上記した適切な水分の存在下に放置又は加熱することにより硬化層を形成することができる。
【００２２】
なお一般式（３）中の低級アルキル基又はアリール基Ｒ⁴，Ｒ⁵は、例えばメチル基やエチル基、プロピル基やフェニル基などの適宜なものであってよいが、前記性能等の点よりＲ⁴は水素原子又はメチル基であることが、Ｒ⁵はメチル基であることが好ましい。
【００２３】
また炭素数１〜４の有機基Ｒ⁶は、例えばメチル基やエチル基、プロピル基やブチル基の如きアルキル基、メトキシメチル基やメトキシエチル基の如きオキシアルキル基、アセチル基の如きアシル基、イソプロペニル基の如きアルケニル基などの適宜なものであっていてよい。前記性能等の点よりはメチル基やエチル基やイソプロペニル基などであることが好ましい。
【００２４】
さらにＱは、ＣＨ₂ＣＨ₂ＣＨ₂又はＣＨ₂ＣＨ₂ＮＨＣＨ₂ＣＨ₂ＣＨ₂であるが、汚染防止層の形成に際しては、それらのＣＨ₂ＣＨ₂ＣＨ₂とＣＨ₂ＣＨ₂ＮＨＣＨ₂ＣＨ₂ＣＨ₂が混在したものとして用いることもできる。従って汚染防止層の形成には、２種以上のフルオロアミノシラン化合物又は／及びその部分加水分解縮合物を適宜な組合せで併用してもよい。
【００２５】
またさらにｍは、１５〜３５の整数であるが、１５以下では上記したパーフルオロポリエーテル基としての特長が充分に発揮されにくく、３５以上では分子中のアルコキシシリル基の含有割合が相対的に小さくなり縮合反応の進行が遅延して硬化皮膜の形成速度に乏しくなる。なおｎは、２又は３であるが、ｎが２のものと３のものとの併用は許容される。
【００２６】
前記したフルオロアミノシラン化合物の調製は、例えば相当するヘキサフルオロプロピレンオキシド（ＨＦＰＯ）オリゴマー又はそのエステル誘導体とアミノアルキルアルコキシシランを縮合反応させる方式などにより行うことができる。
【００２７】
汚染防止層の形成は、上記した反射防止層の場合に準じて適宜な方法を採りうるが、反射防止効果の均一性や反射干渉色の制御などの点より、スピンコート法、浸漬コート法、カーテンフローコート法などの適宜な薄膜塗布方法や真空蒸着法等の１種又は２種以上を適用した形成方法が好ましい。また作業性等の点よりは、塗布液を紙や布等に含浸させて塗布流延する形成方法が好ましい。
【００２８】
なお塗布液は、例えば１種又は２種以上のシラン系化合物を揮発性溶媒に溶解又は分散させる方法などの適宜な方法で調製することができる。その場合、揮発性溶媒についは、組成物の安定性や溶解性、無機系反射防止層表面の二酸化ケイ素系無機層に対する濡れ性や揮発速度などを考慮して適宜に決定してよく、２種以上の混溶媒とすることもできる。
【００２９】
ちなみに前記の揮発性溶媒としては、例えばパーフルオロヘプタンやパーフルオロオクタンの如きフッ素変性脂肪族炭化水素類、ｍ−キシレンヘキサフロライドやベンゾトリフロライドの如きフッ素変性芳香族炭化水素類、メチルパーフルオロブチルエーテルやパーフルオロ（２−ブチルテトラヒドロフラン）の如きフッ素変性エーテル類、石油ベンジンやミネラルスピリッツ、トルエンやキシレンの如き炭化水素類、アセトンやメチルエチルケトン、メチルイソブチルケトンの如きケトン類などがあげられる。就中、溶解性などの点よりｍ−キシレンヘキサフロライドやパーフルオロ（２−ブチルテトラヒドロフラン）の如きフッ素変性物が好ましく用いうる。
【００３０】
なお塗布液の調製に際しては、シラン系化合物、就中フルオロアミノシラン化合物やその部分加水分解縮合物の加水分解縮合反応の促進を目的に必要に応じて、例えばジブチル錫ジメトキシドやジラウリル酸ジブチル錫の如き有機錫化合物、テトラｎ−ブチルチタネートの如き有機チタン化合物、酢酸やメタンスルホン酸の如き有機酸、塩酸や硫酸の如き無機酸などのアルコキシシラン加水分解縮合触媒を添加することもできる。かかる触媒としては、酢酸やテトラｎ−ブチルチタネートやジラウリル酸ジブチル錫などが特に好ましく用いうる。
【００３１】
形成する汚染防止層の厚さは、適宜に決定しうるが、一般には反射防止性や汚染防止性、水に対する静止接触角や粘着テープの接着力、表面硬度との調和性などの点より、０．００１〜０．５μm、就中０．０１〜０．１μmとされる。なお汚染防止層の形成に際しては、反射防止層の表面を清浄に処理しておくことが好ましい。その処理は、例えば界面活性剤による汚れ除去、有機溶剤による脱脂、フッ素系溶剤による蒸気洗浄などの適宜な方式で行うことができる。また密着性や耐久性の向上などを目的とした適宜な前処理を施すこともでき、特に活性化ガスによる処理や酸、アルカリ等による薬品処理などが好ましい。
【００３２】
本発明による反射防止膜は、反射防止効果等の点より最外面の汚染防止層表面における全光線の反射率に基づいて、その表面反射率が３％以下であることが好ましい。従って、後述の光学素材として支持基材の表裏に反射防止膜を設けた場合には、その表裏における合計の表面反射率が６％以下であることが好ましい。なお表裏に反射防止膜を設けた無色透明の光学素材においては、１００％から光学素材の全光線透過率を引いて、得られた値の半分を片面における表面反射率と定義することもできる。
【００３３】
前記において、汚染防止層表面での表面反射率が高いと、反射防止効果に乏しくて眼鏡レンズ等ではゴーストやフレアなどの反射像を生じ、不快感発生の原因となりやすい。またルッキンググラスやＣＲＴ用フィルタなどでは、面状の反射光で内容物や表示内容が判然としない状態となりやすい。
【００３４】
なお汚染防止層については、ＴＯＦ−ＳＩＭＳ（飛行時間型二次イオン質量スペクトル法）にて表面分析を行うことができる。この方法は、高真空中においた試料表面に弱いエネルギをもつイオンを照射し、表面からでた分子フラグメントを時間分解によりその質量数を検出することにより行うものである。
【００３５】
なお前記の代表的な測定条件を下記する。
測定装置；米国 Phisical Electronics（PHI EVANS）社 ＴＦＳ−２０００
測定条件；一次イオン種 ：Ｇａ（＋）イオン
一次イオンエネルギ ：２５ｋＶ
一次イオン電流（ＤＣ） ：〜１５０ｐＡ
試料電位 ：＋３．２ｋＶ
パルス周波数 ：７．２ｋＨｚ
パルス幅 ：〜１０ｎｓ
バンチング ：無し
帯電中和 ：有り
時間分解能 ：１．１ｎｓ／ｃｈ
二次イオン極性 ：正、負
質量範囲（Ｍ／ｚ） ：０〜１００００
ラスターサイズ ：１２０μｍ□
測定時間 ：２０分
エネルギーフィルタ ：無し
コントラストダイアフラム ：＃０
位置検出器， ：Ｒａｓｔｅｒ
後段加速 ：５ｋＶ
測定真空度 ：〜４×１／１０ ⁸ Ｔｏｒｒ
【００３６】
本発明による反射防止膜は、例えばＬＣＤやＣＲＴやプラズマディスプレイの如き表示装置ないし視認装置等の内部や前面板、偏光板等の光学素子、眼鏡用やカメラ用や双眼鏡用等のレンズ、防眩ミラー等の鏡、重量計等の計器類などの、従来に準じた適宜な物品に適用することができる。その場合、反射防止膜は、前記物品等からなる被処理体に直接付設することもできるし、ガラス板やプラスチック板、あるいは偏光板や拡散板等の光学素子などからなる適宜な支持基材に付設した光学素材として適用することもできる。
【００３７】
上記のように図３、図４に本発明による、支持基材４の片面又は両面に反射防止膜３を設けてなる光学素材を例示したが、その支持基材としては適宜なものを用いてよく、特に限定はない。液状コーティング法等で反射防止膜を形成する場合などには、ガラスやプラスチックからなる支持基材が好ましく用いうる。
【００３８】
また前記においてガラス基材の場合には、反射防止層にＭgＦ₂やＣaＦ₂の如き低屈折率を示すものを含ませることが、高い反射効果を得る点などより好ましい。またプラスチック基材の場合には、反射防止層にＳiＯ₂の如き屈折率が比較的低くて硬度の高いものを含ませることが耐久性などの点より好ましい。
【００３９】
なお前記の支持基材を形成するプラスチックは、適宜なものであってよい。ちなみにそのプラスチックの例としては、ポリメチルメタクリレートやメチルメタクリレート共重合体の如きアクリル系樹脂、ポリカーボネートやジエチレングリコールビスアリルカーボネート（ＣＲ−３９）の如きポリカーボネート系樹脂、ポリエチレンテレフタレートや不飽和ポリエスチルの如きポリエステル系樹脂、トリアセチルセルロースの如きアセテート系樹脂、その他、アクリロニトリル−スチレン共重合体、スチレン系樹脂、ポリ塩化ビニル系樹脂、ポリウレタン系樹脂、エポキシ系樹脂、ポリエーテルサルホン系樹脂、ポリアミド系樹脂、ポリイミド系樹脂、ポリオレフィン系樹脂などがあげられる。
【００４０】
支持基材は、フィルムやシートや板等の適宜な形態を有するものであってよく、その厚さは任意である。また支持基材は、ハードーコート層を有するものであってもよい。この場合には、図４に例示の如く、反射防止膜３と支持基材４の間にハードコート層５を有する形態の光学素材となる。さらに支持基材は、ハードーコート層に代えて、あるいはハードーコート層と共に、例えば反射防止膜の密着性、硬度や耐薬品性、耐久性や染色性等の向上などを目的に、適宜なコート層を有したり、表面処理されたものなどであってもよい。
【００４１】
ちなみに硬度の向上には、特公昭５０−２８０９２号公報や特公昭５０−２８４４６号公報、特公昭５０−３９４４９号公報や特公昭５１−２４３６８号公報、特公昭５７−２７３５号公報や特開昭５２−１１２６９８号公報などに記載された高硬度化用の適宜な材料を用いうる。またチタンやアルミニウムやスズ等の金属又はケイ素からなる酸化物をコーティングする方式や、（メタ）アクリル酸のペンタエリスリトール等による架橋体などからなるアクリル系架橋体の付設なども硬度の向上に有効である。
【００４２】
ハードーコート層も従来に準じて形成することができる。就中、有機ケイ素化合物、特に一般式：Ｒ⁴ _cＲ⁵ _dＳｉ（ＯＲ⁶）_4-c-dで表される有機ケイ素化合物やその加水分解物などの硬化物からなるハードーコート層が好ましい。なお式中のＲ⁴、Ｒ⁵はアルキル基、アルケニル基、アリール基、又はハロゲン基やエポキシ基、グリシドキシ基やアミノ基、メルカプト基やメタクリルオキシ基、シアノ基等を有する炭化水素基などであり、Ｒ⁶は炭素数が１〜８のアルキル基、アルコキシアルキル基、アシル基、又はアリール基などである。またｃ，ｄは０又は１であり、従ってｃ＋ｄは、０，１又は２である。
【００４３】
ハードーコート層は、例えばゾル−ゲル法などにより平均粒径が０．５〜５μmのシリカや金属酸化物などからなる微粒子を含有させる方式、あるいはバフやコロナ放電やイオンエッチングの如き適宜な方法で中心線平均粗さが０．０１〜０．５μmのエッチング表面とする方式などにより、きらめき防止機能を有するものとして付設することもできる。
【００４４】
本発明による反射防止膜及び光学素材は、汚れにくく、汚れが目立ちにくくてその汚れをとりやすく、表面の滑り性が良好で傷付きにくく、それらの性能を長期に持続するなどの特長を有して、例えばＬＣＤ等の各種の視認装置類や偏光板等の各種の光学素子類、眼鏡用等の各種のレンズ類や防眩ミラー等の各種の鏡類、重量計等の各種の計器類などの種々の物品における表面や内部などに配置する反射防止フィルタなどとして好ましく用いることができる。
【００４５】
【実施例】
実施例１
粘着偏光フィルタ（日東電工社製、ＥＧ１４２５ＤＵＡＧ３０）に付設したきらめき防止機能付のハードコート層の上にスパッタリング方式で、ＳiＯ₂層、ＴiＯ₂層、ＳiＯ₂層、ＴiＯ₂層、ＳiＯ₂層の５層をそれぞれλ／４光学膜厚で順次積層して反射防止層を付設した。
【００４６】
次に、下記式で表されるフルオロアミノシラン化合物３重量部を、ヘキサフルオロメタキシレンとパーフルオロヘプタンの混合溶媒１００部に溶解させたコーティング溶液に前記の反射防止層を浸漬し、２０ｃｍ／分の速度で引き上げてコーティング処理し、室温下に一昼夜（２４時間）放置してコーティング層を硬化させて汚染防止層を形成し、反射防止膜を有する光学素材を得た。
【化３】

【００４７】
実施例２
シラン系化合物として、下記式で表されるフルオロアミノシラン化合物を用いたほかは実施例１に準じて光学素材を得た。
【化４】

【００４８】
実施例３
シラン系化合物として、下記式で表されるフルオロアミノシラン化合物を用いたほかは実施例１に準じて光学素材を得た。
【化５】

【００４９】
実施例４
コーティング層の硬化処理を、６０℃、９５％ＲＨの湿熱条件下に１０分間放置する方式で行った他は、実施例１に準じて光学素材を得た。
【００５０】
実施例５
コーティング溶液を蒸着源として、汚染防止層を真空蒸着方式で形成したほかは、実施例１に準じて光学素材を得た。
【００５１】
比較例１
汚染防止層を付設しないほかは実施例１に準じて光学素材を得た。
【００５２】
比較例２
数平均分子量１００のパーフルオロポリエーテル基を有するポリエーテル鎖の末端にトリメトキシシリル基を結合したシラン系化合物を用いて汚染防止層を形成したほかは実施例４に準じて光学素材を得た。
【００５３】
比較例３
パーフロオロポリエーテル基に代えて、数平均分子量が１０００以上のパーフルオロアルキル基を有するポリシロキサン系化合物を用いて汚染防止層を形成したほかは比較例２に準じて光学素材を得た。
【００５４】
比較例４
シラン系化合物として、下記式で表されるフルオロアミノシラン化合物を用いたほかは実施例１に準じて光学素材を得た。
【化６】

【００５５】
比較例５
シラン系化合物として、Ｃ₈Ｆ₁₇Ｃ₂Ｈ₄Ｓi（ＯＣＨ₃）₃からなるパーフルオロアルキルシランを用いたほかは実施例１に準じて光学素材を得た。
【００５６】
評価方法
実施例、比較例で得た光学素材について、下記の特性を調べた。
静止接触角
直径１．５mmの水滴を針先に形成し、それを汚染防止層の表面に接触させて汚染防止層上に水滴を移し、水滴と面の静止接触角を接触角計（協和界面化学社製、ＣＡ−Ｄ型）にて測定した。
【００５７】
外観
目視にて、反射干渉色及びその均一性、濁りなどを調べた。
【００５８】
反射防止性
波長５５０nmの光を１５度の入射角で入射させ、分光光度計（島津製作所製、ＭＰＳ−２０００）にて絶対鏡面反射率を測定した。
【００５９】
接着力
ポリエステル粘着テープ（日東電工社製、Ｎｏ．３１Ｂ）を常温で、２ｋｇのローラを一往復させる方式で汚染防止層に圧着し、２０分間放置後、１８０度ピール値（剥離速度３００mm／分）を測定した。
【００６０】
汚染防止性
額に指を２秒間押し当てて、その指を汚染防止層の表面に５秒間押し当てることにより指紋を付着させ、目視にて指紋の付き具合を評価し、かつ付着した指紋をティッシュペーパにて拭取り、その除去性を評価した。その評価基準は下記による。なお実施例４〜８、比較例４，５については、５人のテスターがそれぞれ試験を行って、その評価結果を平均した。
良好：指紋が目立たず、かつ容易に拭取れた場合
不良：指紋が目立ち、かつ拭取りにくい場合
不可：指紋が著しく目立ち、かつ拭取れない場合
【００６１】
耐久性
イソプロピルアルコールを含浸させたペーパで汚染防止層の表面を２０回擦った後（比較例１〜３）、又はイソプロピルアルコールを含浸させたセルロース製不織布で汚染防止層の表面を３０回擦った後（実施例１〜４、比較例４，５）、前記汚染防止性試験と同様に指紋を付着させ、それをティッシュペーパにて拭取り、その除去性を評価した。なお評価基準は下記による。
良好：拭取れた場合
不良：拭取れない場合
【００６２】
前記の結果を表１に示した。
【表１】

【００６４】
表１より、実施例では、指紋等の汚れが付着しにくく、付着した汚染が目立ちにくくて、その汚染をティッシュペーパ等で容易に拭取ることができ、その効果を長期に持続して、撥水性にも優れていることがわかる。なお実施例では、耐久性試験の場合にも汚染防止性に準じた評価で、指紋が目立たずかつ容易に拭取れる良好の評価であったが、比較例４，５では指紋が著しく目立ち、かつ拭取れない不可の評価であった。
【図面の簡単な説明】
【図１】反射防止膜例の断面図
【図２】他の反射防止膜例の断面図
【図３】光学素材例の断面図
【図４】他の光学素材例の断面図
【符号の説明】
３：反射防止膜
１：反射防止層
２：汚染防止層
４：支持基材
５：ハードコート層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides an antireflection film excellent in removability of fingerprints and the like suitable for various visual devices such as LCDs, CRTs and plasma display devices, various lenses for glasses and cameras, mirrors, and the like. It relates to the attached optical material.
[0002]
BACKGROUND OF THE INVENTION
In general anti-reflective coatings that are provided on the surface of visual devices and the like, contamination such as dirt, fingerprints, sweat, saliva, hairdressing, etc. is likely to adhere, and the surface reflectance changes due to such adhesion, There is a problem that contamination is more conspicuous than in the case of simple transparent plates, such as the appearance of the deposit appearing white and the display content being unclear, so it is excellent in preventing the contamination and removing the contamination. Providing an antireflection film has been a long-standing problem.
[0003]
Conventionally, as an antireflection film for the purpose of improving pollution prevention, etc., on the surface of an antireflection layer comprising a single layer or a multilayer inorganic layer having a surface layer mainly composed of silicon dioxide formed by a PVD method, Those having a cured layer made of an organic polysiloxane polymer or a perfluoroalkyl group-containing polymer have been known (Japanese Patent Publication No. 6-5324).
[0004]
However, when human or oily contamination such as dirt or fingerprints adheres, it is difficult to wipe with ordinary tissue paper, and the contamination is spread to the thin film. There was a problem that removal could not be achieved.
[0005]
[Technical Problem of the Invention]
The present invention makes it difficult for contamination to adhere, and even when contamination is attached, the contamination is not conspicuous, and the attached contamination including human contamination such as dirt and fingerprints can be easily wiped off with tissue paper or the like. The wiping operation makes it difficult to get scratched, and water droplets can be easily shaken off, and the performances such as anti-contamination, easy wiping removal, scratch resistance and water repellency are maintained for a long time. Development of anti-reflection film and optical material is an issue.
[0006]
[Means for solving problems]
The present invention relates to a fluorine-containing silane system in which the adhesive force of an adhesive tape is 1.0 N / 20 mm or less on the surface of an inorganic antireflection layer having a single layer structure or a multilayer structure having a silicon dioxide-based inorganic layer as a surface layer. It has a contamination preventing layer comprising a cured layer, and the contamination preventing layer is composed of a cured layer comprising at least one of a fluoroaminosilane compound represented by the following general formula (3) and a partial hydrolysis condensate thereof. The present invention provides an optical material characterized by having an antireflection film and the antireflection film on a supporting substrate.
[Chemical 2]

In the general formula (3), R ⁴ is a hydrogen atom, a lower alkyl group or an aryl group, R ⁵ is a lower alkyl group or an aryl group, R ⁶ is an organic group having 1 to 4 carbon atoms, and Q is CH ₂ CH ₂ CH ₂ or CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ , m is an integer of 15 to 35, and n is 2 or 3.
[0007]
【The invention's effect】
According to the present invention, since the fluoroaminosilane compound or the like according to the general formula (3) is used, it is excellent in performance such as antifouling property, easy wiping removal property of adhesion contamination, scratch resistance and water repellency. Contaminated with a silicon dioxide-based inorganic layer with excellent water and oil repellency, anti-contamination properties, chemical resistance, lubricity, releasability, scratch resistance, etc. A protective layer can be formed, and it is difficult for oil-based and water-based contaminants such as dirt and fingerprints to adhere, and even if contaminants adhere, it is not noticeable and can be easily wiped off with tissue paper etc. Therefore, it is possible to obtain an antireflection film or an optical material thereof which can hardly be damaged and can be easily shaken off, and can maintain such performance for a long time.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The antireflection film of the present invention is a fluorine whose adhesive tape has an adhesive force of 1.0 N / 20 mm or less on the surface of a single-layer or multi-layer inorganic antireflection layer having a silicon dioxide-based inorganic layer as a surface layer. It has a contamination prevention layer consisting of a contained silane-based cured layer. The optical material of the present invention has the antireflection film on a support substrate.
[0009]
1 and 2 illustrate the antireflection film according to the present invention. Moreover, the optical material by this invention was illustrated in FIG. 3, FIG. Reference numeral 3 denotes an antireflection film composed of the inorganic antireflection layer 1 and the contamination prevention layer 2, 4 denotes a support base material, and 11, 12, and 13 denote inorganic layers that form the inorganic antireflection layer 1. In addition, 5 is a hard-coat layer provided as needed.
[0010]
The inorganic antireflection layer in the antireflection film is a part responsible for a substantial antireflection function. In the present invention, except that it has a silicon dioxide inorganic layer on its surface, that is, in the case of a single layer structure As shown in FIG. 1, an appropriate structure having a single-layer structure or a multi-layer structure can be used except that the inorganic antireflection layer 1 is composed of the silicon dioxide-based inorganic layer 13 as illustrated in FIG.
[0011]
Thus, for example, A. VASICEK, "OPUTICS OF THIN FILMS" P159-283 [North Holland Publishing Company, Amsterdam (1960): NORTH-HOLLAND PUBLISHING COMPANY, AMSTERDAM (1960)], JP 58-46301 A, JP 59-49501 A It can also be formed as an antireflection layer having a structure according to the prior art, as in the prior art based on Japanese Laid-Open Patent Publication No. 59-50401, Japanese Laid-Open Patent Publication No. 1-294709, and Japanese Patent Publication No. 6-5324. .
[0012]
For the formation of the inorganic antireflection layer, an inorganic material such as an inorganic oxide, an inorganic halide, or a composite thereof can be used. Specific examples of the inorganic substance include inorganic oxides such as SiO ₂ , ZrO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , and TiO ₂ , MgF ₂ , BaF ₂ , CaF ₂ , LaF ₂ , LiF, NaF, SrF _2. Inorganic halides such as
[0013]
The inorganic material forming the antireflection layer is used in an appropriate state such as a dispersion in which one or more of the inorganic materials are mixed with a solid material or a binder polymer according to the following forming method. In addition, it is preferable to use a composition containing 30% by weight or more of an inorganic substance from the viewpoints of hardness and anti-staining properties. The binder polymer may be any suitable polymer and is not particularly limited. However, various organosilicon compounds capable of forming polyorganosiloxane and hydrolysates thereof are preferable from the viewpoint of hardness. Can be used.
[0014]
The inorganic antireflection layer is formed by, for example, various PVD (Phisical Vapor Deposition) methods represented by a vacuum deposition method, a sputtering method, an ion plating method, etc., a spin coating method, a dip coating method, a curtain flow coating method, It can be performed by an appropriate thin film forming method such as a fluid coating method typified by a roll coating method, a spray coating method, a flow coating method or the like.
[0015]
Wherein the the PVD method, such as inorganic halides such as inorganic oxides and MgF ₂ of SiO ₂ or the like exemplified above are preferably used, particularly the surface layer to become silicon dioxide-based inorganic layer, the surface hardness height and pollution From the viewpoint of adhesion of the prevention layer, a layer containing silicon dioxide as a main component by the PVD method is preferable.
[0016]
The antireflection layer preferably has a multilayer structure in view of the antireflection effect and the like. In particular, one or two or more layers having a higher refractive index than the silicon dioxide-based inorganic layer of the surface layer are included. A layer structure is preferable. In that case, for the setting of the thickness and refractive index of each layer, the above-described A. It can be applied in accordance with conventional techniques such as VASICEK's “OPUTICS OF THIN FILMS”.
[0017]
In addition, the antireflection layer may include a conductive layer that exhibits a static electricity removing effect and an electromagnetic wave shielding effect in order to prevent adhesion of dust and the like due to charging. Such a conductive layer is formed as a transparent conductive film made of, for example, a metal thin film such as gold, silver, or aluminum, or an inorganic oxide thin film such as tin oxide, indium oxide, or a mixture thereof (ITO). In the visible region, an inorganic oxide transparent conductive film that absorbs very little light is particularly preferable.
[0018]
The anti-contamination layer attached to the silicon dioxide-based inorganic layer on the surface of the inorganic anti-reflection layer is formed of a fluorine-containing silane-based cured layer having an adhesive strength of 1.0 N / 20 mm or less. Silane-based cured layers with adhesive tape adhesive strength exceeding 1.0N / 20mm have poor anti-contamination properties, especially human contamination such as dirt and fingerprints, and poor wiping and removal of contamination. .
[0019]
The adhesive strength is JIS
C 2338 (polyester adhesive tape for electrical insulation) or CES
Adhesive tape with an adhesive strength of 2.0 N / 10 mm or more, which is provided with an acrylic adhesive layer on a polyester film, the quality of which is specified by M 5023-6 (polyester film adhesive tape), and a contamination-preventing layer (silane-based cured layer) at room temperature ) And is peeled 180 degrees at a peeling speed of 300 mm / min.
[0020]
Fluorine-modified groups are efficiently oriented on the surface, and exhibit excellent water and oil repellency, antifouling properties, chemical resistance, lubricity, release properties, scratch resistance, etc., and firmly adhere to the silicon dioxide inorganic layer Examples of the silane compound that can be preferably used from the viewpoint of the stable formation of the contamination prevention layer include the fluoroaminosilane compound represented by the general formula (3) and / or a partial hydrolysis condensate thereof.
[0021]
According to the above-mentioned fluoroaminosilane compound and / or its partial hydrolysis-condensation product, it hardens by hydrolysis in the presence of moisture, and thus forms a cured layer by leaving or heating in the presence of the appropriate moisture described above. can do.
[0022]
The lower alkyl group or aryl group R ⁴ or R ⁵ in the general formula (3) may be an appropriate group such as a methyl group, an ethyl group, a propyl group, or a phenyl group. R ⁴ is preferably a hydrogen atom or a methyl group, and R ⁵ is preferably a methyl group.
[0023]
The organic group R ⁶ having 1 to 4 carbon atoms is, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, an oxyalkyl group such as a methoxymethyl group or a methoxyethyl group, an acyl group such as an acetyl group, It may be an appropriate one such as an alkenyl group such as an isopropenyl group. A methyl group, an ethyl group, an isopropenyl group, or the like is preferable from the viewpoint of performance.
[0024]
Furthermore, Q is CH ₂ CH ₂ CH ₂ or CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ , and when forming the contamination prevention layer, these CH ₂ CH ₂ CH ₂ and CH ₂ CH ₂ NHCH ₂ CH ₂ It can also be used as a mixture of CH ₂ . Therefore, two or more kinds of fluoroaminosilane compounds or / and partial hydrolysis condensates thereof may be used in combination in an appropriate combination for the formation of the contamination prevention layer.
[0025]
Further, m is an integer of 15 to 35, but if it is 15 or less, the above-mentioned characteristics as a perfluoropolyether group are not sufficiently exhibited, and if it is 35 or more, the content of alkoxysilyl groups in the molecule is relatively high. It becomes small and the progress of the condensation reaction is delayed and the formation rate of the cured film becomes poor. In addition, although n is 2 or 3, combined use with the thing of n and 2 and 3 is accept | permitted.
[0026]
The above-mentioned fluoroaminosilane compound can be prepared, for example, by a method in which a corresponding hexafluoropropylene oxide (HFPO) oligomer or an ester derivative thereof is condensed with an aminoalkylalkoxysilane.
[0027]
The formation of the anti-staining layer can take an appropriate method according to the case of the anti-reflection layer described above, but in terms of uniformity of the anti-reflection effect and control of the reflection interference color, the spin coating method, the dip coating method, A suitable thin film coating method such as a curtain flow coating method, or a forming method applying one or more types such as a vacuum vapor deposition method is preferable. From the viewpoint of workability and the like, a forming method in which paper or cloth is impregnated with a coating solution and cast is preferred.
[0028]
The coating solution can be prepared by an appropriate method such as a method of dissolving or dispersing one or two or more silane compounds in a volatile solvent. In that case, the volatile solvent may be appropriately determined in consideration of the stability and solubility of the composition, the wettability of the inorganic antireflection layer surface to the silicon dioxide inorganic layer, the volatilization rate, and the like. The above mixed solvent can also be used.
[0029]
Incidentally, examples of the volatile solvent include fluorine-modified aliphatic hydrocarbons such as perfluoroheptane and perfluorooctane, fluorine-modified aromatic hydrocarbons such as m-xylene hexafluoride and benzotrifluoride, and methyl perfluoromethane. Fluorine-modified ethers such as fluorobutyl ether and perfluoro (2-butyltetrahydrofuran), petroleum benzine and mineral spirits, hydrocarbons such as toluene and xylene, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Among them, fluorine-modified products such as m-xylene hexafluoride and perfluoro (2-butyltetrahydrofuran) can be preferably used from the viewpoint of solubility.
[0030]
In preparing the coating solution, for example, dibutyltin dimethoxide or dibutyltin dilaurate may be used for the purpose of accelerating the hydrolysis condensation reaction of silane compounds, especially fluoroaminosilane compounds and partial hydrolysis condensates thereof. An alkoxysilane hydrolysis condensation catalyst such as an organic tin compound, an organic titanium compound such as tetra-n-butyl titanate, an organic acid such as acetic acid or methanesulfonic acid, or an inorganic acid such as hydrochloric acid or sulfuric acid may be added. As such a catalyst, acetic acid, tetra-n-butyl titanate, dibutyltin dilaurate or the like can be used particularly preferably.
[0031]
The thickness of the antifouling layer to be formed can be determined as appropriate, but in general, in terms of antireflection and antifouling properties, static contact angle with water, adhesive strength of adhesive tape, and consistency with surface hardness, 0.001 to 0.5 μm, especially 0.01 to 0.1 μm. In forming the anti-contamination layer, it is preferable to clean the surface of the anti-reflection layer. The treatment can be performed by an appropriate method such as removal of dirt with a surfactant, degreasing with an organic solvent, or steam cleaning with a fluorinated solvent. In addition, an appropriate pretreatment for the purpose of improving adhesion and durability can be performed, and treatment with an activated gas, chemical treatment with acid, alkali, or the like is particularly preferable.
[0032]
The antireflection film according to the present invention preferably has a surface reflectance of 3% or less based on the reflectance of all rays on the outermost antifouling layer surface from the viewpoint of antireflection effect and the like. Therefore, when an antireflection film is provided on the front and back of the supporting substrate as an optical material described later, the total surface reflectance on the front and back is preferably 6% or less. In a colorless and transparent optical material provided with antireflection films on the front and back surfaces, the total light transmittance of the optical material is subtracted from 100%, and half of the obtained value can be defined as the surface reflectance on one side.
[0033]
In the above, when the surface reflectance on the surface of the contamination prevention layer is high, the antireflection effect is poor, and a spectacle lens or the like produces a reflection image such as ghost or flare, which is likely to cause discomfort. In addition, with a looking glass, a CRT filter, etc., the contents and display contents tend to be unclear due to planar reflected light.
[0034]
In addition, about a pollution prevention layer, surface analysis can be performed by TOF-SIMS (time-of-flight type secondary ion mass spectrometry). This method is performed by irradiating ions with weak energy onto a sample surface placed in a high vacuum and detecting the molecular number of molecular fragments emitted from the surface by time resolution.
[0035]
The typical measurement conditions are as follows.
Measuring device: USA Phisical Electronics (PHI EVANS) TFS-2000
Measurement conditions; primary ion species: Ga (+) ion primary ion energy: 25 kV
Primary ion current (DC): ~ 150 pA
Sample potential: +3.2 kV
Pulse frequency: 7.2 kHz
Pulse width: 10 ns
Bunching: None Charge neutralization: Available Time resolution: 1.1 ns / ch
Secondary ion polarity: positive, negative mass range (M / z): 0-10000
Raster size: 120μm
Measurement time: 20 minutes Energy filter: None Contrast diaphragm: # 0
Position detector,: Raster
Second stage acceleration: 5 kV
Measuring degree of vacuum: ˜4 × 1/10 ⁸ Torr
[0036]
The antireflection film according to the present invention is used for the interior of a display device such as an LCD, a CRT, or a plasma display or a visual display device, an optical element such as a front plate or a polarizing plate, a lens for glasses, a camera, or binoculars, an anti-glare film. The present invention can be applied to appropriate conventional articles such as mirrors such as mirrors and measuring instruments such as weighing scales. In that case, the antireflection film can be directly attached to the object to be processed such as the above-mentioned article or the like, or on an appropriate support substrate made of a glass plate, a plastic plate, or an optical element such as a polarizing plate or a diffusion plate. It can also be applied as an attached optical material.
[0037]
As described above, the optical material in which the antireflection film 3 is provided on one side or both sides of the support base material 4 according to the present invention is illustrated in FIGS. 3 and 4, but an appropriate material is used as the support base material. Well, there is no particular limitation. When an antireflection film is formed by a liquid coating method or the like, a supporting substrate made of glass or plastic can be preferably used.
[0038]
In the case of the glass substrate, it is more preferable that the antireflection layer contains a material having a low refractive index such as MgF ₂ or CaF ₂ because a high reflection effect is obtained. In the case of a plastic substrate, it is preferable from the viewpoint of durability and the like that the antireflection layer contains a material having a relatively low refractive index such as SiO ₂ and high hardness.
[0039]
The plastic forming the support substrate may be any appropriate one. Incidentally, examples of the plastic include acrylic resins such as polymethyl methacrylate and methyl methacrylate copolymer, polycarbonate resins such as polycarbonate and diethylene glycol bisallyl carbonate (CR-39), and polyester resins such as polyethylene terephthalate and unsaturated polyester. Resin, acetate resin such as triacetyl cellulose, acrylonitrile-styrene copolymer, styrene resin, polyvinyl chloride resin, polyurethane resin, epoxy resin, polyethersulfone resin, polyamide resin, polyimide Resin, polyolefin resin and the like.
[0040]
The support base material may have an appropriate form such as a film, a sheet, or a plate, and the thickness thereof is arbitrary. Further, the support substrate may have a hard coat layer. In this case, as illustrated in FIG. 4, the optical material has a hard coat layer 5 between the antireflection film 3 and the support base 4. Further, the supporting substrate has an appropriate coating layer instead of the hard coating layer or together with the hard coating layer, for example, for the purpose of improving the adhesion, hardness, chemical resistance, durability, dyeability, etc. of the antireflection film. Or surface-treated.
[0041]
Incidentally, in order to improve the hardness, Japanese Patent Publication No. 50-28092, Japanese Patent Publication No. 50-28446, Japanese Patent Publication No. 50-39449, Japanese Patent Publication No. 51-24368, Japanese Patent Publication No. 57-2735 and Japanese Patent Publication No. An appropriate material for increasing the hardness described in Japanese Patent No. 52-112698 can be used. In addition, a method of coating an oxide made of silicon or metal such as titanium, aluminum or tin, or an acrylic cross-linked body made of a cross-linked body such as pentaerythritol of (meth) acrylic acid is effective for improving the hardness. is there.
[0042]
The hard coat layer can also be formed according to the conventional method. Among them, a hard coat layer made of a cured product such as an organosilicon compound, particularly an organosilicon compound represented by the general formula: R ⁴ _c R ⁵ _d Si (OR ⁶ ) _4-cd and a hydrolyzate thereof is preferable. R ⁴ and R ⁵ in the formula are alkyl groups, alkenyl groups, aryl groups, or hydrocarbon groups having halogen groups, epoxy groups, glycidoxy groups, amino groups, mercapto groups, methacryloxy groups, cyano groups, and the like. , R ⁶ is an alkyl group having 1 to 8 carbon atoms, an alkoxyalkyl group, an acyl group, or an aryl group. Also, c and d are 0 or 1, so c + d is 0, 1 or 2.
[0043]
The hard coat layer is centered by a method of containing fine particles made of silica or metal oxide having an average particle diameter of 0.5 to 5 μm by a sol-gel method or the like, or an appropriate method such as buff, corona discharge or ion etching. It can also be provided as having a glitter prevention function, for example, by an etching surface having a line average roughness of 0.01 to 0.5 μm.
[0044]
The antireflective film and optical material according to the present invention have features such as being resistant to dirt, being less noticeable and easy to remove, having good surface slipperiness and scratch resistance, and maintaining their performance for a long period of time. For example, various visual devices such as LCDs, various optical elements such as polarizing plates, various lenses for glasses, various mirrors such as anti-glare mirrors, various instruments such as weighing scales, etc. It can preferably be used as an antireflection filter disposed on the surface or inside of various articles.
[0045]
【Example】
Example 1
The SiO ₂ layer, the TiO ₂ layer, the SiO ₂ layer, the TiO ₂ layer, and the SiO ₂ layer 5 are formed by sputtering on the hard coat layer with a glitter prevention function attached to the adhesive polarizing filter (manufactured by Nitto Denko Corporation, EG1425DUAG30). Each layer was sequentially laminated with a λ / 4 optical film thickness to provide an antireflection layer.
[0046]
Next, the antireflection layer is immersed in a coating solution in which 3 parts by weight of a fluoroaminosilane compound represented by the following formula is dissolved in 100 parts of a mixed solvent of hexafluorometaxylene and perfluoroheptane, and 20 cm / min. The coating treatment was performed by pulling up at a speed, and the coating layer was cured by allowing it to stand at room temperature all day and night (24 hours) to form a contamination prevention layer, thereby obtaining an optical material having an antireflection film.
[Chemical 3]

[0047]
Example 2
An optical material was obtained according to Example 1 except that a fluoroaminosilane compound represented by the following formula was used as the silane compound.
[Formula 4]

[0048]
Example 3
An optical material was obtained according to Example 1 except that a fluoroaminosilane compound represented by the following formula was used as the silane compound.
[Chemical formula 5]

[0049]
Example 4
An optical material was obtained in the same manner as in Example 1 except that the coating layer was cured by leaving the coating layer under a wet heat condition of 60 ° C. and 95% RH for 10 minutes.
[0050]
Example 5
An optical material was obtained according to Example 1 except that the contamination prevention layer was formed by a vacuum deposition method using the coating solution as a deposition source.
[0051]
Comparative Example 1
An optical material was obtained according to Example 1 except that no contamination prevention layer was provided.
[0052]
Comparative Example 2
An optical material was obtained according to Example 4 except that a contamination-preventing layer was formed using a silane compound in which a trimethoxysilyl group was bonded to the end of a polyether chain having a perfluoropolyether group having a number average molecular weight of 100 . .
[0053]
Comparative Example 3
An optical material was obtained in the same manner as in Comparative Example 2 except that a pollution control layer was formed using a polysiloxane compound having a perfluoroalkyl group having a number average molecular weight of 1000 or more instead of the perfluoropolyether group.
[0054]
Comparative Example 4
An optical material was obtained according to Example 1 except that a fluoroaminosilane compound represented by the following formula was used as the silane compound.
[Chemical 6]

[0055]
Comparative Example 5
An optical material was obtained in the same manner as in Example 1 except that perfluoroalkylsilane composed of C ₈ F ₁₇ C ₂ H ₄ Si (OCH ₃ ) ₃ was used as the silane compound.
[0056]
Evaluation Methods The following characteristics were examined for optical materials obtained in Examples and Comparative Examples.
A water droplet with a static contact angle diameter of 1.5mm is formed on the tip of the needle, and it is brought into contact with the surface of the pollution control layer to transfer the water drop onto the pollution control layer. The contact angle meter (Kyowa Interface) (Chemical company make, CA-D type).
[0057]
The appearance of the reflection interference color, its uniformity, and turbidity were examined by visual inspection.
[0058]
Light having an antireflection wavelength of 550 nm was incident at an incident angle of 15 degrees, and the absolute specular reflectance was measured with a spectrophotometer (manufactured by Shimadzu Corporation, MPS-2000).
[0059]
Adhesive polyester pressure-sensitive adhesive tape (Nitto Denko, No. 31B) is pressure-bonded to the anti-contamination layer by reciprocating a 2 kg roller at room temperature, left for 20 minutes, and then peeled at 180 degrees (peeling speed 300 mm / min) ) Was measured.
[0060]
A finger is pressed against the antifouling forehead for 2 seconds, the finger is pressed against the surface of the antifouling layer for 5 seconds, the fingerprint is attached, the degree of fingerprint attachment is visually evaluated, and the attached fingerprint is removed from the tissue. The removal property was evaluated by wiping with paper. The evaluation criteria are as follows. In addition, about Examples 4-8 and Comparative Examples 4 and 5, five testers each tested and averaged the evaluation result.
Good: When the fingerprint is not noticeable and easily wiped off. Bad: When the fingerprint is noticeable and difficult to wipe. Not possible: When the fingerprint is noticeable and cannot be wiped off.
After rubbing the surface of the antifouling layer 20 times with paper impregnated with durable isopropyl alcohol (Comparative Examples 1-3), or rubbing the surface of the antifouling layer 30 times with a cellulose nonwoven fabric impregnated with isopropyl alcohol. After (Examples 1 to 4, Comparative Examples 4 and 5), a fingerprint was attached in the same manner as in the anti-staining test, and it was wiped with tissue paper to evaluate its removability. The evaluation criteria are as follows.
Good: When wiped off Defective: When wiped off [0062]
The results are shown in Table 1.
[Table 1]

[0064]
From Table 1, in Examples, dirt such as fingerprints hardly adheres, and the attached contamination is not noticeable. The contamination can be easily wiped off with tissue paper, etc., and the effect is maintained for a long period of time. It turns out that it is excellent also in aqueous property. In the examples, even in the durability test, the evaluation according to the anti-contamination property was a good evaluation that the fingerprints were not noticeable and could be easily wiped off, but in Comparative Examples 4 and 5, the fingerprints were noticeable and The evaluation was impossible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an example of an antireflection film. FIG. 2 is a cross-sectional view of another example of an antireflection film. FIG. 3 is a cross-sectional view of an example of an optical material. ]
3: Antireflection film 1: Antireflection layer 2: Antifouling layer 4: Support base material 5: Hard coat layer

Claims (9)

The surface of the inorganic antireflection layer having a single-layer structure or a multi-layer structure having a silicon dioxide-based inorganic layer as a surface layer is composed of a fluorine-containing silane-based cured layer having an adhesive strength of 1.0 N / 20 mm or less. An antireflection film comprising a contamination prevention layer , wherein the contamination prevention layer comprises a cured layer comprising at least one of a fluoroaminosilane compound represented by the following general formula (3) and a partial hydrolysis-condensation product thereof .

In the general formula (3), R ⁴ is a hydrogen atom, a lower alkyl group or an aryl group, R ⁵ is a lower alkyl group or an aryl group, R ⁶ is an organic group having 1 to 4 carbon atoms, and Q is CH ₂ CH ₂ CH ₂ or CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ , m is an integer of 15 to 35, and n is 2 or 3. 2. The antireflection film according to claim 1, wherein the antifouling layer has a thickness of 0.001 to 0.5 μm, an adhesive strength of the adhesive tape of 0.5 N / 20 mm or less, and a static contact angle of 80 degrees or more with respect to water. The antireflection film according to claim 1 or 2, wherein the silicon dioxide-based inorganic antireflection layer has a conductive layer and has a surface reflectance of 3% or less. The antireflection film according to any one of claims 1 to 3, wherein the antifouling layer comprises a layer cured by hydrolysis of the silane compound. The silicon dioxide-based inorganic layer is formed by a PVD method, and the contamination prevention layer is at least one method selected from the group consisting of a spin coating method, a dip coating method, a curtain flow coating method, and a vacuum deposition method. The antireflection film according to claim 1, which is formed. An optical material comprising the antireflection film according to claim 1 on a supporting substrate. The optical material according to claim 6, further comprising a hard coat layer between the antireflection film and the support substrate. 8. The hard coat layer has a glitter prevention function due to the inclusion of silica particles having an average particle size of 0.5 to 5 [mu] m, or an etching surface having a center line average roughness of 0.01 to 0.5 [mu] m. Optical material. The optical material according to claim 6, wherein the optical material is used as an antireflection filter for a visual recognition device.

Images