JP4378972B2 - Antireflection film, method of manufacturing antireflection film, antireflection member - Google Patents

Description

【００９２】
Ｒ^３は、下記［化２］で示される加水分解基である。Ｒ^６は、炭素数２〜１０の２価炭化水素基であり、２価炭化水素基としては、Ｒ^１と同様のものが例示される。また、Ｒ^７は、炭素数１〜１０の１価炭化水素基であり、Ｒ^２と同様のものが例示されるが、メチル基であることが好ましい。ａは０、１又は２、好ましくは０又は１である。
【００９３】
【化２】

【００９４】
また、上記の［化１］において、Ｒ^４は、炭素数１〜１０の１価炭化水素基であり、Ｒ^２と同様のものを挙げることができるが、これはその炭素原子に結合した水素原子の一部又は全部がフッ素原子にて置換されていてもよく、このような置換基として、Ｒ^１と同様なものが挙げられ、トリフロロプロピル基等を例示することができる。
【００９５】
さらに、Ｒ^５は、Ｒ^３又はＲ^４を示し、各Ｒ^５は互いに同一であっても異なっていてもよいが、ｎが０の場合、少なくとも１個のＲ^５はＲ^３である。ｋは０〜１００、好ましくは０〜６０、ｍは０〜１００、好ましくは０〜６０、ｎは０〜５である。上述したように、ｎ＝０の場合、Ｒ^５の少なくとも１個はＲ^３であり、従って上記の［化１］の化合物は、分子中に少なくとも１個のＲ^３（加水分解性基）を含み、またフロロアルキル基を有してもよいシロキサンである。
【００９６】
また、第２バインダー６がコロイダルシリカを含有することが好ましい（請求項１３の発明）。このようにすると、低屈折率層４内の中空微粒子２間の空隙５へ第２コーティング剤組成物が浸入しやすくなるものである。そうすると、第２コーティング剤組成物を塗布した後の低屈折率層４内において、中空微粒子２間の空隙５に存在していた空気が押し出されると共に、中空微粒子２間の結合が第２コーティング剤組成物によってさらに補強され、耐摩耗性が向上し、コロイダルシリカにより屈折率のさらなる低減が可能となるものである。ここで、コロイダルシリカとしては、平均粒子径が０．５〜１００ｎｍのものが、特に好ましい。平均粒子径が０．５ｎｍ未満であると、中空微粒子２の分散性が低下するおそれがあり、逆に平均粒子径が１００ｎｍを超えると、中空微粒子２間の空隙５に充填されにくくなるおそれがある。
【００９７】
なお、コロイダルシリカ自体は、内部に空洞１を有していなくてもよい。このようなコロイダルシリカであっても、第２バインダー６と共存させることによって、形成される反射防止膜の機械的強度を向上させることができ、さらには、表面平滑性と耐クラック性をも改善することができるからである。
【００９８】
また、コロイダルシリカの形態としては、特に限定されるものではなく、例えば、粉体状の形態でもゾル状の形態でもよい。コロイダルシリカをゾル状の形態として使用する場合、特に限定されるものではないが、例えば、水分散コロイダルシリカあるいはアルコール等の親水性の有機溶媒に分散したコロイダルシリカを使用することができる。一般にこのようなコロイダルシリカは、固形分としてのシリカを２０〜５０重量％含有しており、この値からシリカ配合量を決定することができる。
【００９９】
ここで、水分散コロイダルシリカを使用する場合には、このコロイダルシリカ中に固形分以外として存在する水は、シラン化合物、例えば、４官能加水分解可能オルガノシランの加水分解に使用することができる。従って、この加水分解の際の水の量には、水分散性コロイダルシリカの水を加算する必要がある。水分散性コロイダルシリカは通常、水ガラスから作られるものであり、市販品を容易に入手して使用することができる。
【０１００】
また、有機溶媒分散コロイダルシリカは、上記の水分散コロイダルシリカの水を有機溶媒と置換することによって容易に調製することができる。このような有機溶媒分散コロイダルシリカも、水分散コロイダルシリカと同様に、市販品を容易に入手して使用することができる。有機溶媒分散コロイダルシリカにおいて、コロイダルシリカが分散している有機溶媒の種類は、特に限定されるものではないが、例えば、メタノール、エタノール、イソプロパノール（ＩＰＡ）、ｎ−ブタノール、イソブタノール等の低級脂肪族アルコール類、エチレングリコール、エチレングリコールモノブチルエーテル、酢酸エチレングリコールモノエチルエーテル等のエチレングリコール誘導体、ジエチレングリコール、ジエチレングリコールモノブチルエーテル等のジエチレングリコール誘導体、及びジアセトンアルコール等の親水性有機溶媒を挙げることができ、これらからなる群より選ばれる１種あるいは２種以上を使用することができる。さらに、これらの親水性有機溶媒と併用して、トルエン、キシレン、ヘキサン、ヘプタン酢酸エチル、酢酸ブチル、メチルエチルケトン、メチルイソブチルケトン、メチルエチルケトオキシム等の１種あるいは２種以上のものを使用することができる。
【０１０１】
また、第２バインダー６が、屈折率が１．２〜１．４５及び平均粒子径が０．５〜１００ｎｍの微粒子を含有することが好ましい（請求項１４の発明）。その理由は、上記のような平均粒子径を有する微粒子であると、中空微粒子２間の空隙５に容易に充填され、中空微粒子２間の結合を補強して、耐摩耗性をさらに向上させることができるからであり、しかも屈折率が上記のように低ければ、耐摩耗性を保持した状態で、低屈折率層４全体の屈折率をさらに低減することが可能となるからである。上記の屈折率及び平均粒子径を有する微粒子としては、多孔質シリカゾル、中空シリカゾル、ＭｇＦ_２ゾル等を例示することができる。なお、屈折率が１．２よりも小さい微粒子は入手が困難であり、逆に、屈折率が１．４５よりも大きい微粒子を用いると、低屈折率化の効果があまり期待できないおそれがある。また、微粒子の平均粒子径０．５ｎｍ未満であると、第２コーティング剤組成物中における分散性が低下するおそれがあり、逆に微粒子の平均粒子径が１００ｎｍを超えると、低屈折率層４内の中空微粒子２間の空隙５に充填するのが困難となるおそれがある。
【０１０２】
また、第２バインダー６が中空シリカゾルを含有することが好ましい（請求項１５の発明）。このようにすると、耐摩耗性をさらに向上させることができると共に、低屈折率層４全体の屈折率をさらに低減することができるものである。なお、第２コーティング剤組成物における中空シリカゾルの含有量は１〜６０体積％であることが好ましい。１体積％未満であると、第２コーティング剤組成物による低屈折率化の効果が少ないおそれがあり、逆に６０体積％を超えると、第２コーティング剤組成物中における中空シリカゾルの分散性が悪化し、低屈折率層４内の中空微粒子２間の空隙５に充填されるのが困難となるおそれがある。
【０１０３】
そして、本発明に係る反射防止膜を製造するにあたっては、以下のようにして行うことができる。すなわち、既述の第１コーティング剤組成物をハードコート層８（あるいは透明支持体７）の表面にワイヤーバーコーター等で塗布（塗工）する。次に、これを乾燥させて中空微粒子２を第１バインダー３で相互に結合させることによって、図２（図４）に示すような低屈折率層４を形成する。その後、この低屈折率層４の表面に第２コーティング剤組成物をワイヤーバーコーター等で塗布（塗工）する。そして、これを乾燥させることによって、図３（図５）に示すような低屈折率層４内の中空微粒子２間の空隙５に第２バインダー６が密に充填された反射防止膜を製造することができるものである。
【０１０４】
このようにして得た反射防止膜にあって、内部に空洞１を有する中空微粒子２が低屈折率層４内において高充填されていることによって、低屈折率を十分に確保して反射防止を可能とするものであり、また、中空微粒子２間の空隙５に第２バインダー６を充填することによって、中空微粒子２間の結合を補強して耐摩耗性を向上することができるものである。
【０１０５】
なお、第１、第２コーティング剤組成物は、一般的なウェットコーティングの塗工方法で塗工することが可能で、液相法（ディップコーティング法、スピンコーティング法、スプレーコーティング法、ロールコーティング法、グラビアロールコーティング法、リバースコーティング法、トランスファーロールコーティング法、マイクログラビアコーティング法、キャストコーティング法、カレンダーコーティング法、ダイコーティング法等）によって、透明支持体７やハードコート層８の表面に塗布（塗工）することができる。また、第１、第２コーティング剤組成物を塗布（塗工）した後においては、加熱乾燥により、低屈折率層４中の溶剤を揮発させ、その後、加熱、加湿、紫外線照射、電子線照射等を行い、低屈折率層４を硬化させるものである。
【０１０６】
【実施例】
以下、本発明を実施例によって具体的に説明する。
【０１０７】
透明支持体（透明樹脂フィルム）及びハードコート材料として、以下のものを用いた。
【０１０８】
・透明樹脂フィルム：ＰＥＴフィルム、東洋紡績（株）製「Ａ４３００」（１８８μｍ厚）
・ハードコート材料：アクリル系紫外線硬化型樹脂、大日精化工業（株）製「セイカビームＰＥＴ−ＨＣ１５」（有効成分６０％）
そして上記の透明樹脂フィルムの表面に上記のハードコート材料をワイヤーバーコーター＃１０番で塗布し、これを４０℃で１分間乾燥させた後に、ＵＶ照射（１０００ｍＪ／ｃｍ^２）して硬化させることによって、ハードコート層を形成した。
【０１０９】
（参考例１）
テトラエトキシシラン２０８部（「部」は「重量部」を意味する。以下同じ。）にメタノール３５６部を加え、さらに水１８部及び０．０１Ｎの塩酸水溶液１８部を加え、これをディスパーを用いて混合することによって、混合液を得た。この混合液を２５℃恒温槽中で２時間攪拌することによって、重量平均分子量を８５０に調整したシリコーンレジン（Ａ）を得た。
【０１１０】
次に、低屈折率微粒子として中空シリカＩＰＡ（イソプロパノール）分散ゾル（固形分２０重量％、平均粒子径６０ｎｍ、触媒化成工業（株）製）を用い、これをシリコーンレジン（Ａ）に加え、中空シリカ微粒子／シリコーンレジンが縮合固形物換算で体積比５０／５０となるように配合し、その後、全固形分が１％になるようにメタノールで希釈することによって、第１コーティング剤組成物を調製した。得られたゾル液の屈折率は１．３６であった。
【０１１１】
次に、シリコーンレジン（Ａ）を全固形分が０．５％になるようにメタノールで希釈することによって、第２コーティング剤組成物を調製した。
【０１１２】
そして、上記のようにして形成したハードコート層の表面に、コロナ処理を施し、まず、第１コーティング剤組成物を膜厚が約１００ｎｍになるようにワイヤーバーコーターでコーティング（塗布）した。次に、これを１００℃、１時間の条件で乾燥させ、硬化させることによって、低屈折率層を形成した。その後、この低屈折率層の表面に第２コーティング剤組成物を固形分膜厚換算で５０ｎｍとなるようにワイヤーバーコーターでコーティング（塗布）した。そして、これを１００℃、１時間の条件で乾燥させ、硬化させることによって、反射防止膜を製造した。
【０１１３】
（参考例２）
参考例１において、第１コーティング剤組成物の中空シリカ微粒子／シリコーンレジンが縮合固形物換算で体積比９０／１０となるように配合した以外は、参考例１と同様にして反射防止膜を製造した。
【０１１４】
（参考例３）
参考例２において、第２コーティング剤組成物に熱硬化型含フッ素ポリマー（ＪＳＲ株式会社製「ＪＮ７２１５」）を含有させ、第２コーティング剤組成物の全固形分に対し、０．５重量％になるようにＭＥＫ（メチルエチルケトン）で希釈したものを使用した以外は、参考例２と同様にして反射防止膜を製造した。
【０１１５】
（参考例４）
参考例１において、第１コーティング剤組成物中の低屈折率微粒子として中空シリカ微粒子とシリカ微粒子メタノール分散品（固形分３０重量％、平均粒子径２０ｎｍ、日産化学（株）製、メタノールシリカゾル、屈折率１．４６）を重量比で８：２となるように混合したものを使用した以外は、参考例２と同様にして反射防止膜を製造した。
【０１１６】
（参考例５）
有機ジルコニウム成分（硬化触媒）としてＺｒ（ＯＣ_４Ｈ_９）_３（Ｃ_５Ｈ_７Ｏ_２）をさらに用い、これを第２バインダーコーティング剤組成物の全固形分に対し、ＺｒＯ_２換算固形分で１０重量％配合した第２バインダーコーティング剤組成物を用いた以外は、参考例２と同様にして反射防止膜を製造した。
【０１１７】
（参考例６）
フルオロシランカップリング剤（含フッ素化合物）として「ＴＳＬ８２３３」（ＧＥ東芝シリコーン（株）製）を第２コーティング剤組成物の全固形分に対し、１重量％になるように配合したものを用いた以外は、参考例２と同様にして反射防止膜を製造した。
【０１１８】
（参考例７）
フルオロシランカップリング剤（含フッ素化合物）として「ＴＳＬ８２３３」（ＧＥ東芝シリコーン（株）製）を第２コーティング剤組成物の全固形分に対し、４０重量％になるように配合したものを用いた以外は、参考例２と同様にして反射防止膜を製造した。
【０１１９】
（参考例８）
シリコーンオイル（シリコーン化合物）としてメチルハイドロジェンシリコーンオイル「ＴＳＷ８３１」及び硬化触媒として上記シリコーンオイルに対し２０重量％の硬化触媒「ＣＷ８０」（ともにＧＥ東芝シリコーン（株）製）の混合物を、第２コーティング剤組成物の全固形分に対し、１重量％になるように配合したものを用いた以外は、参考例２と同様にして反射防止膜を製造した。
【０１２０】
（参考例９）
シリカ微粒子としてシリカ微粒子メタノール分散品（固形分３０重量％、平均粒子径２０ｎｍ、日産化学（株）製、メタノールシリカゾル、屈折率１．４６）を用い、これをシリコーンレジン（Ａ）に加え、シリカ微粒子／シリコーンレジンが縮合固形物換算で体積比５０／５０となるように配合し、その後、全固形分が０．５％になるようにメタノールで希釈することによって、第２コーティング剤組成物を得た。このようにして得られたゾル液の屈折率は１．３６であった。そしてこの第２コーティング剤組成物を用いた以外は、参考例２と同様にして反射防止膜を製造した。
【０１２１】
（参考例１０）
低屈折率微粒子として中空シリカＩＰＡ（イソプロパノール）分散ゾル（固形分２０重量％、平均粒子径６０ｎｍ、触媒化成工業（株）製）を用い、これをシリコーンレジン（Ａ）に加え、中空シリカ微粒子／シリコーンレジンが縮合固形物換算で体積比５０／５０となるように配合し、その後、全固形分が０．５％になるようにメタノールで希釈することによって得た、第２コーティング剤組成物を用いた以外は、参考例２と同様にして反射防止膜を製造した。
【０１２２】
（比較例１）
参考例２における第１コーティング剤組成物のみを膜厚が約１００ｎｍになるようにワイヤーバーコーターでコーティング（塗布）した。そしてこれを１００℃、１時間の条件で乾燥させ、硬化させることによって、反射防止膜を製造した。
【０１２３】
（比較例２）
参考例２における中空シリカ微粒子の代わりに、通常のシリカ微粒子（内部に空洞がないもの）メタノール分散品（固形分３０重量％、平均粒子径２０ｎｍ、日産化学（株）製、メタノールシリカゾル）をシリカ微粒子／シリコーンレジンが縮合固形物換算で体積比９０／１０となるように配合した以外は、参考例２と同様にして反射防止膜を製造した。
【０１２４】
参考例１〜１０及び比較例１、２について、低屈折率層内空隙率（中空微粒子内の空洞及び中空微粒子間の空隙が占める体積の割合）を求め、さらに、この低屈折率層内空隙率に対する第２コーティング剤組成物の充填率を求めた。その結果を表１に示す。なお、上記の低屈折率層内空隙率及び第２コーティング剤組成物の充填率は、低屈折率層（反射防止膜）断面のＦＥ−ＳＥＭ観察像を用い、その面積分率から算出した。
【０１２５】
そして、参考例１〜１０及び比較例１、２の反射防止膜について、反射率、接触角、油性ペン拭き取り性、指紋拭き取り性、耐摩耗性（スチールウール試験）、密着性（クロスカットテープ試験）を評価した。その結果を表２に示す。なお、各種の物性評価方法を以下に示す。
【０１２６】
（ａ）光学特性
反射率測定：透明樹脂フィルムの表面（図１の最下面）をサンドペーパーでこすり、艶消しの黒色塗料を塗布した後、波長５５０ｎｍの光の入射角５゜での片面の反射率を測定した。この測定には日立製作所（株）製「Ｕ−３４００」を用いた。
【０１２７】
（ｂ）防汚性
（ｂ）−１ 接触角測定：接触角計〔ＣＡ−Ｘ型：協和界面科学（株）製〕を用いて、乾燥状態（２０℃−６５％ＲＨ）で直径１．８μｌの液滴を針先に作り、これを低屈折率層の表面に接触させて液滴を作った。接触角とは、固体と液体が接する点における液体表面に対する接線と固体表面がなす角で、液体を含む方の角度で定義した。液体には、蒸留水を使用した。
【０１２８】
（ｂ）−２ 油性ペンの拭き取り性：反射防止膜の表面に付着した油性ペンをセルロース製不織布〔ベンコットＭ−３：旭化成（株）製〕で拭き取り、その取れ易さを目視判定を行った。判定基準を以下に示す。
【０１２９】
「○」：油性ペンを完全に拭き取ることができる。
【０１３０】
「△」：油性ペンの拭き取り跡が残る。
【０１３１】
「×」：油性ペンを拭き取ることができない。
【０１３２】
（ｂ）−３ 指紋の拭き取り性：反射防止膜の表面に付着した指紋をセルロース製不織布〔ベンコットＭ−３：旭化成（株）製〕で拭き取り、その取れ易さを目視判定を行った。判定基準を以下に示す。
【０１３３】
「○」：指紋を完全に拭き取ることができる。
【０１３４】
「△」：指紋の拭き取り跡が残る。
【０１３５】
「×」：指紋の拭き取り跡が拡がり、拭き取ることができない。
【０１３６】
（ｃ）機械強度
（ｃ）−１ 耐摩耗性：反射防止膜の表面をスチールウール〔ボンスター＃００００：日本スチールウール（株）製〕により２５０ｇ／ｃｍ^２及び５００ｇ／ｃｍ^２で１０回擦り、傷の有無を目視判定を行った（スチールウール試験）。判定基準を以下に示す。
【０１３７】
「○」：傷を確認することができない。
【０１３８】
「△」：数本傷を確認できる。
【０１３９】
「×」：傷が多数確認できる。
【０１４０】
（ｃ）−２ 密着性：反射防止膜の表面を１ｍｍ角１００点カット後、粘着セロハンテープ〔ニチバン（株）製工業用２４ｍｍ巾セロテープ（登録商標）〕による剥離の有無を目視判定を行った（クロスカットテープピール試験）。
【０１４１】
【表１】

【０１４２】
【表２】

【０１４３】
表１にみられるように、参考例１〜１０のものはいずれも低屈折率層内空隙率が高く、しかも第２バインダーの充填率が高いことが確認される。よって、参考例１〜１０の反射防止膜は、反射防止性能及び耐摩耗性の両方の特性に優れていると考えられる。一方、比較例１のものは低屈折率層内空隙率は高いものの、第２バインダーの充填率が低く、また、比較例２のものは第２バインダーの充填率は高いものの、低屈折率層内空隙率が低いことが確認される。つまり、比較例１の反射防止膜は耐摩耗性が悪く、比較例２の反射防止膜は反射防止性能が悪いと考えられる。
【０１４４】
上記の事項は、表２にみられるように各種物性試験によって実証された。しかも、含フッ素化合物やシリコーン化合物を用いた参考例３、６〜８の反射防止膜は、防汚性にも優れていることが実証された。
【０１４５】
すなわち、本発明者が研究の結果、発明した反射防止膜は、屈折率が非常に低く、耐摩耗性に優れ、低屈折率層の剥離がなく、また低屈折率層の表面に、指紋、皮脂、油性マジック、化粧品等の汚れが付着することを防止し、付着しても容易に拭き取ることが可能となるものである。そして、このような反射防止膜を用いることにより、画像表示装置等の表示面における光の反射を格段に防止することができるものと考えられる。
【０１４６】
【発明の効果】
上記のように本発明の請求項１に係る反射防止膜は、内部に一つの空洞を有する略球形の微粒子であって前記空洞が略球形の外殻によって完全に包囲されている中空微粒子を第１バインダーで相互に結合させることによって形成される低屈折率層内の中空微粒子間の空隙に第２バインダーを充填するので、内部に空洞を有する中空微粒子が低屈折率層内において高充填されていることによって、低屈折率を十分に確保して反射防止を可能とするものであり、また、中空微粒子間の空隙に第２バインダーを充填することによって、中空微粒子間の結合を補強して耐摩耗性を向上することができるものである。
また、平均粒子径がそれぞれｄ１，ｄ２，……，ｄｎ（ただし、ｄ１＞ｄ２＞……＞ｄｎ）の中空微粒子をｎ種類混合して用いると共に、平均粒子径がｄｋ−１の中空微粒子と平均粒子径がｄｋの中空微粒子とがｄｋ＜０．５×ｄｋ−１（ｋ＝２〜ｎ、２≦ｎ）の関係を有するので、平均粒子径ｄｋの中空微粒子が平均粒子径ｄｋ−１の中空微粒子間の間隙に充填され、複数種類からなる中空微粒子の最大体積分率が上昇するものである。
【０１４７】
また請求項２の発明は、中空微粒子として、屈折率が１．２〜１．４５及び平均粒子径が０．５〜２００ｎｍのものを用い、この中空微粒子が内部の空洞も含めて低屈折率層全体の４０〜９５体積％を占めると共に、第１バインダー、第２バインダー及び中空微粒子間の空隙が残りの６０〜５体積％を占めるので、低屈折率化による反射防止機能をさらに高めることができると共に、耐摩耗性をさらに向上させることができるものである。
【０１４８】
また請求項３の発明は、中空微粒子内の空洞及び中空微粒子間の空隙が低屈折率層内の１０〜６０体積％を占め、かつ、第２バインダーが中空微粒子間の空隙全体の４０体積％以上を占めるので、低屈折率化による反射防止機能をさらに高めることができると共に、耐摩耗性をさらに向上させることができるものである。
【０１４９】
また請求項４の発明は、中空微粒子として１種類以上のものを用いると共に、そのうち少なくとも１種類のものが中空シリカゾルであるので、低屈折率層の屈折率低減の効果をさらに高く得ることができるものである。
【０１５１】
また請求項５の発明は、低屈折率層に対する第２バインダーの接触角が０〜７０°であるので、第２バインダーが低屈折率層内の中空微粒子間の空隙へ容易に浸入し、反射防止膜を緻密な薄膜として製造することができるものである。
【０１５２】
また請求項６の発明は、第１バインダーが反応性有機珪素化合物からなるものであるので、中空微粒子とのぬれ性、分散性が良好となるものである。
【０１５３】
また請求項７の発明は、第２バインダーが反応性有機珪素化合物からなるものであるので、中空微粒子とのぬれ性が良好となり、中空微粒子間の空隙に第２バインダーが浸入しやすくなるものである。
【０１５４】
また請求項８の発明は、第２バインダーの分子量が１００〜５０００であるので、低屈折率層内の中空微粒子間の空隙への浸入が容易になり、反射防止膜を緻密な薄膜として製造することができるものである。
【０１５５】
また請求項９の発明は、第２バインダーが硬化触媒を含有するので、縮合反応が促進されて低屈折率層中の架橋密度が高くなり、低屈折率層の耐水性及び耐アルカリ性を向上させることができるものである。
【０１５６】
また請求項１０の発明は、第２バインダーが含フッ素化合物を含有するので、低屈折率層の表面を汚れから保護することができ、また、たとえ汚れが付着したとしてもこの汚れを容易に除去することができるものである。
【０１５７】
また請求項１１の発明は、第２バインダーが含フッ素化合物を０．１〜５０重量％含有するので、防汚性をさらに高めることができるものである。
【０１５８】
また請求項１２の発明は、第２バインダーがシリコーン化合物を含有するので、低屈折率層の表面を汚れから保護することができ、また、たとえ汚れが付着したとしてもこの汚れを容易に除去することができるものである。
【０１５９】
また請求項１３の発明は、第２バインダーがコロイダルシリカを含有するので、低屈折率層内の中空微粒子間の空隙へ第２コーティング剤組成物が浸入しやすくなるものである。
【０１６０】
また請求項１４の発明は、第２バインダーが、屈折率が１．２〜１．４５及び平均粒子径が０．５〜１００ｎｍの微粒子を含有するので、中空微粒子間の空隙に容易に充填され、中空微粒子間の結合を補強して、耐摩耗性をさらに向上させることができると共に、耐摩耗性を保持した状態で、低屈折率層全体の屈折率をさらに低減することが可能となるものである。
【０１６１】
また請求項１５の発明は、第２バインダーが中空シリカゾルを含有するので、耐摩耗性をさらに向上させることができると共に、低屈折率層全体の屈折率をさらに低減することができるものである。
【０１６２】
本発明の請求項１６に係る反射防止膜の製造方法は、内部に一つの空洞を有する略球形の微粒子であって前記空洞が略球形の外殻によって完全に包囲されている中空微粒子を含有する第１バインダーを透明支持体の表面に塗布し、これを乾燥させて中空微粒子を第１バインダーで相互に結合させることによって低屈折率層を形成した後に、この低屈折率層に第２バインダーを塗布することによって、低屈折率層内の中空微粒子間の空隙に第２バインダーを充填するので、内部に空洞を有する中空微粒子が低屈折率層内において高充填されていることによって、低屈折率を十分に確保して反射防止を可能とするものであり、また、中空微粒子間の空隙に第２バインダーを充填することによって、中空微粒子間の結合を補強して耐摩耗性を向上することができるものである。
また、平均粒子径がそれぞれｄ１，ｄ２，……，ｄｎ（ただし、ｄ１＞ｄ２＞……＞ｄｎ）の中空微粒子をｎ種類混合して用いると共に、平均粒子径がｄｋ−１の中空微粒子と平均粒子径がｄｋの中空微粒子とがｄｋ＜０．５×ｄｋ−１（ｋ＝２〜ｎ、２≦ｎ）の関係を有するので、平均粒子径ｄｋの中空微粒子が平均粒子径ｄｋ−１の中空微粒子間の間隙に充填され、複数種類からなる中空微粒子の最大体積分率が上昇するものである。
【０１６３】
本発明の請求項１７に係る反射防止部材は、請求項１乃至１５のいずれかに記載の反射防止膜を透明支持体の片面又は両面に形成するので、反射防止膜として種々の用途に使用することができるものである。
【０１６４】
また請求項１８の発明は、透明支持体が透明樹脂フィルム又は透明樹脂板であるので、反射防止膜として種々の用途に使用することができるものである。
【図面の簡単な説明】
【図１】本発明の実施の形態の一例を示す反射防止部材の断面図である。
【図２】第２コーティング剤組成物を塗布する前の低屈折率層を示す概略断面図である。
【図３】第２コーティング剤組成物を塗布した後の低屈折率層（反射防止膜）を示す概略断面図である。
【図４】図２の電子顕微鏡写真（撮影倍率：１０万倍）を示すものである。
【図５】図３の電子顕微鏡写真（撮影倍率：１０万倍）を示すものである。
【符号の説明】
１ 空洞
２ 中空微粒子
３ 第１バインダー
４ 低屈折率層
５ 空隙
６ 第２バインダー
７ 透明支持体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antireflection film capable of preventing reflection with a low refractive index, a method for producing the antireflection film, and a display (CRT display) obtained by forming the antireflection film on a transparent support. The present invention relates to an antireflection member such as an antireflection film applied to the display screen surface of a plasma display, a liquid crystal display, a projection display, an EL display, or the like.
[0002]
[Prior art]
Anti-reflection coatings are various display devices such as cathode ray tube display (CRT), plasma display panel (PDP), liquid crystal display (LCD), projection display, electroluminescence display (ELD), touch panel, optical lens, glasses. It is used in various fields such as a lens, an antireflection treatment in a photolithography process, and an antireflection treatment on the surface of a solar cell panel.
[0003]
For the antireflection function, it is necessary to provide a layer having a refractive index lower than that of the transparent support (hereinafter referred to as “low refractive index layer”). As a low refractive index material for forming this low refractive index layer, in the case of an inorganic material, MgF₂(Refractive index 1.38), SiO₂(Refractive index 1.46) can be mentioned, and in the case of an organic material, perfluororesin (refractive index 1.35 to 1.45) and fine particles using the same can be mentioned. Usually MgF₂The layer by is formed by a vapor phase method such as vacuum deposition or sputtering, and SiO 2₂The layer by is formed by a vapor phase method such as vacuum deposition or sputtering, or a liquid phase method by a sol-gel method. The layer made of perfluoro resin is formed by a liquid phase method. In general, a vapor deposition method can provide an antireflection film having excellent optical properties, but has low productivity and is not suitable for mass production.
[0004]
Further, for example, in the case of using a low refractive index material as described above for the purpose of preventing reflection of an image display panel such as a display, in most cases, the surface of the transparent support such as glass or film is refracted by the transparent support. The antireflection performance is obtained by forming two or more layers having a refractive index higher than the refractive index (hereinafter referred to as “high refractive index layer”) and a low refractive index layer. It is known that the minimum value of the reflectance decreases as the refractive index difference between the high refractive index material for forming the high refractive index layer and the low refractive index material increases. Conventionally, when a PET film substrate (refractive index 1.67) is used as a transparent support, the effect of lowering the refractive index can be achieved even if a perfluoro resin (refractive index 1.40) is used as the low refractive index material. Was insufficient, and a high refractive index layer was required between the transparent support and the low refractive index layer. However, if a material having a refractive index lower than that of the perfluoro resin can be obtained, it is expected that the antireflection performance can be improved with only one low refractive index layer formed of this material. In addition to antireflection performance, when providing antistatic performance, electromagnetic wave shielding performance, etc., it is necessary to form a multilayer antireflection layer as two or more layers on the surface of the transparent support. In addition, by using a material having a lower refractive index than that of perfluororesin, it is expected that the degree of freedom in designing the multilayer antireflection layer will be expanded and better antireflection performance can be obtained.
[0005]
On the other hand, in order to further reduce the refractive index of the low refractive index layer, in addition to using the above-mentioned existing material, by forming voids between the particles constituting the low refractive index material, the low refractive index layer A method of introducing voids into the inside is effective. That is, the refractive index of air is 1.00, and the low refractive index layer containing air in the gap has a very low refractive index. Conventionally, a method for forming voids by incorporating fine particles into a low refractive index layer has been proposed. Japanese Patent Publication No. 60-59250 (Patent Document 1) discloses an antireflection layer having fine pores and fine inorganic particles. The antireflection layer is formed by a liquid phase method. The fine vacancies are formed by performing an activated gas treatment after applying the layer and releasing the gas from the layer. JP-A-2-245702 (Patent Document 2) discloses an antireflection film in which two kinds of fine particles are mixed and the mixing ratio is changed in the film thickness direction. The fine particles are SiO 2 generated by the thermal decomposition of ethyl silicate.₂It is adhered by. In the thermal decomposition of ethyl silicate, carbon dioxide and water vapor are also generated by the combustion of the ethyl portion. As shown in FIG. 1 of this publication, carbon dioxide and water vapor are desorbed from the layer, resulting in voids between the fine particles. Japanese Patent Application Laid-Open No. 7-48527 (Patent Document 3) discloses an antireflection film containing an inorganic fine powder made of porous silica and a binder. In JP-A-9-288201 (Patent Document 4), fine particles made of a fluorine-containing polymer are provided. In JP-A-11-6902 (Patent Document 5), a polymer shell is provided around inorganic fine particles. In JP-A-11-326601 (Patent Document 6), two or more silica fine particles are stacked in each layer to form an antireflection film in which voids are formed between the fine particles. Yes.
[0006]
However, in general, since the low refractive index layer is provided on the side farthest from the transparent support, that is, on the surface side of the antireflection film, it is necessary to have wear resistance and antifouling performance in addition to low refractive index properties. In the case of a low refractive index layer into which voids are introduced, this layer becomes porous, and if it is a thin film, the mechanical strength decreases, and as a result, the wear resistance decreases. Further, when oily dirt enters the gap in the scale, the dirt removing property is impaired, and the antireflection performance is also lowered. Therefore, in order to protect the low refractive index layer serving as the surface layer from dirt and improve the abrasion resistance, generally, a measure for providing an overcoat layer containing a fluorine-containing compound on the surface of the low refractive index layer has been often taken. .
[0007]
However, when an overcoat layer is provided on a low refractive index layer having voids between particles, a coating liquid for forming the overcoat layer (hereinafter also referred to as “overcoat material”) is contained in the low refractive index layer. It penetrates into the gap, and on the contrary, the refractive index of the low refractive index layer increases. Therefore, in Japanese Patent Application Laid-Open No. 2000-9907 (Patent Document 7), even if the overcoat material enters the voids between the particles in the low refractive index layer, the increase in the refractive index of this layer can be suppressed. As described above, an overcoat layer is provided using a fluorine-containing compound having a relatively low refractive index. However, as a result of research by the present inventor, it has been confirmed that the voids in the low refractive index layer decrease as the overcoat material penetrates in the above-described configuration, thereby increasing the refractive index. On the other hand, in Japanese Patent Application Laid-Open No. 2000-75105 (Patent Document 8), in order to prevent the overcoat material from entering the interparticle voids in the low refractive index layer, the overcoat material has a high molecular weight. In addition, it is disclosed that fine particles are added to this material. Similarly, Japanese Patent Application Laid-Open No. 2000-284102 (Patent Document 9) discloses that the slipping property is improved when the material is a polymer having a specific perfluoroalkyl polyether side chain. Yes. In Japanese Patent Laid-Open No. 2001-100003 (Patent Document 10), a polymer layer is laminated on a low refractive index layer having interparticle voids, and an overcoat layer is laminated thereon using an overcoat material. I have to.
[0008]
However, even in the conventional method of applying an overcoat material to the low refractive index layer having voids between the particles, the material penetrates into the interparticle voids that control the low refractive index. . That is, although an improvement in abrasion resistance and antifouling property can be expected by the overcoat layer, a trade-off relationship occurs in which the refractive index of the low refractive index layer increases as the voids decrease. In addition, even if a coating for ensuring abrasion resistance and antifouling properties can be formed only on the surface of the low refractive index layer while keeping the inter-particle voids of the low refractive index material as much as possible, the overcoat obtained by this coating can be obtained. The thickness of the layer is as very thin as 50 nm or less, and the effect of improving wear resistance and antifouling properties is very limited.
[0009]
Incidentally, spherical hollow silica fine particles having a refractive index lower than that of perfluororesin are disclosed in Japanese Patent Application Laid-Open No. 2001-233611 (Patent Document 11). It is described that this fine particle has a cavity (or cavity) surrounded by an outer shell, and the refractive index of the fine particle itself can be 1.30 or less. It has been suggested that a transparent thin film having a low refractive index can be formed by applying a coating composition obtained by dispersing such fine particles in a matrix-forming material. As described above, it is generally known that a low refractive index layer can be formed by using hollow fine particles. However, specific technical matters required for forming such a layer are as follows. There are still no documents that suggest such technical matters.
[0010]
For example, JP 2002-265866 A (Patent Document 12) discloses a low refractive index film obtained by adding 5 to 95 wt% of a hollow silica sol in a perfluoropolyether-containing organosilicon compound. In general, as the amount of hollow particles added is increased, the refractive index of the film can be reduced. However, in the case of particle-filled composites, the maximum volume fraction of particles when closely packed with spherical particles of equal particle size (fully monodisperse) is 74% by volume according to the Horsfield packing model, and When filled with simple cubes, the volume is 52% by volume (see, for example, Non-Patent Document 1). Usually, although it fluctuates from the theoretical value due to the particle size distribution of the fine particles and conversely, poor dispersion (secondary agglomeration) etc., poor dispersion occurs in the high filling region where the filling amount of particles exceeds 40% by volume. As a result, the wear resistance and homogeneity of the low refractive index film itself are impaired.
[0011]
[Patent Document 1]
Japanese Patent Publication No. 60-59250 (claims, etc.)
[Patent Document 2]
JP-A-2-245702 (Claims, Fig. 1 etc.)
[Patent Document 3]
JP 7-48527 A (claims, etc.)
[Patent Document 4]
JP-A-9-288201 (Claims, FIG. 1 etc.)
[Patent Document 5]
Japanese Patent Laid-Open No. 11-6902 (Claims, FIG. 1, etc.)
[Patent Document 6]
JP 11-326601 A (Claims, FIG. 1 etc.)
[Patent Document 7]
JP 2000-9907 (Claims, FIG. 1 etc.)
[Patent Document 8]
JP 2000-75105 A (Claims, FIG. 1 etc.)
[Patent Document 9]
Japanese Unexamined Patent Publication No. 2000-284102 (Claims, FIG. 1 etc.)
[Patent Document 10]
JP 2001-100003 A (Claims, FIG. 1 etc.)
[Patent Document 11]
Japanese Patent Laid-Open No. 2001-233611 (Claims, FIG. 1, etc.)
[Patent Document 12]
JP 2002-265866 A (Claims, FIG. 1 and the like)
[Non-Patent Document 1]
Handbook of Powder Engineering, edited by Powder Society of Japan, Nikkan Kogyo Shimbun, March 30, 1998, 2nd edition, 1 edition, p. 149-150
[0012]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, the hollow fine particles are highly filled in the low-refractive index layer, and the anti-reflection by ensuring a low refractive index by the cavity inside the hollow fine particles, An antireflection film that can reinforce the bond between the hollow microparticles by filling the voids between the hollow microparticles with a second binder to improve the wear resistance, a method of manufacturing the antireflection film, and the antireflection film An object of the present invention is to provide an antireflective member manufactured using the above.
[0013]
In addition to the above effects, an antireflection film capable of imparting antifouling properties by containing a fluorine-containing compound or a silicone-containing compound in the second binder, a method for producing the antireflection film, and the antireflection An object of the present invention is to provide an antireflection member manufactured using a film.
[0014]
[Means for Solving the Problems]
  The antireflection film according to claim 1 of the present invention includes substantially spherical fine particles having a single cavity 1 inside, and the hollow fine particles 2 in which the cavity 1 is completely surrounded by a substantially spherical outer shell 9 are formed. In the antireflection film composed of the low refractive index layer 4 formed by bonding with each other with one binder 3, the gap 5 between the hollow fine particles 2 in the low refractive index layer 4 is filled with the second binder 6, A mixture of n kinds of hollow fine particles having average particle diameters of d1, d2,..., Dn (where d1> d2>...> Dn) are used, and hollow fine particles and average particles having an average particle diameter of dk-1. Hollow fine particles having a diameter of dk are dk <0.5 × dk−1 (k =2˜n, 2 ≦ n).
[0015]
The invention of claim 2 uses the hollow fine particles 2 of claim 1 having a refractive index of 1.2 to 1.45 and an average particle size of 0.5 to 200 nm. 40% to 95% by volume of the entire low refractive index layer 4 including the cavity 1 is occupied, and the gap 5 between the first binder 3, the second binder 6 and the hollow fine particles 2 occupies the remaining 60 to 5% by volume. It is a feature.
[0016]
The invention of claim 3 is the invention according to claim 1 or 2, wherein the void 1 between the hollow fine particles 2 and the gap 5 between the hollow fine particles 2 occupy 10 to 60% by volume in the low refractive index layer 4; The binder 6 occupies 40% by volume or more of the entire space 5 between the hollow fine particles 2.
[0017]
The invention of claim 4 is characterized in that, in any one of claims 1 to 3, one or more kinds of hollow fine particles 2 are used, and at least one of them is a hollow silica sol. .
[0019]
  And claims5The invention of claim 1 to claim 14In any of the above, the contact angle of the second binder 6 with respect to the low refractive index layer 4 is 0 to 70 °.
[0020]
  And claims6The invention of claim 1 to claim 15In any of the above, the first binder 3 is made of a reactive organic silicon compound.
[0021]
  And claims7The invention of claim 1 to claim 16In any of the above, the second binder 6 is made of a reactive organic silicon compound.
[0022]
  And claims8The invention of claim 1 to claim 17In any of the above, the molecular weight of the second binder 6 is 100 to 5,000.
[0023]
  And claims9The invention of claim 1 to claim 18In any of the above, the second binder 6 contains a curing catalyst.
[0024]
  Claim 10The invention of claim 1 to claim 19In any of the above, the second binder 6 contains a fluorine-containing compound.
[0025]
  Claim 11The invention of claim 10The second binder 6 contains 0.1 to 50% by weight of a fluorine-containing compound.
[0026]
  Claim 12The invention of claim 1 to claim 19In any one of the above, the second binder 6 contains a silicone compound.
[0027]
  Claim 13The invention of claim 1 to 12In any one of the above, the second binder 6 contains colloidal silica.
[0028]
  Claim 14The invention of claim 1 to 13In any one of the above, the second binder 6 is characterized by containing fine particles having a refractive index of 1.2 to 1.45 and an average particle diameter of 0.5 to 100 nm.
[0029]
  Claim 15The invention of claim 14The second binder 6 includes a hollow silica sol.
[0030]
  According to a sixteenth aspect of the present invention, there is provided a method for producing an antireflection film, which is a substantially spherical fine particle having one cavity 1 therein, and the hollow 1 is completely surrounded by a substantially spherical outer shell 9. After forming the low refractive index layer 4 by applying the first binder 3 containing 2 to the surface of the transparent support 7, drying it and bonding the hollow microparticles 2 with the first binder 3, By applying the second binder 6 to the low refractive index layer 4, the second binder 6 is filled in the voids 5 between the hollow fine particles 2 in the low refractive index layer 4, and the average particle diameters are d1 and d2, respectively. ,..., Dn (where d1> d2>. dk <0.5 × dk−1 ( =2˜n, 2 ≦ n).
[0031]
  Claim 1 of the present invention7The antireflection member according to claim 1 is the first aspect.5The antireflection film according to any one of the above is formed on one side or both sides of the transparent support 7.
[0032]
  Claim 18The invention of claim 17The transparent support 7 is a transparent resin film or a transparent resin plate.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0034]
FIG. 1 is a cross-sectional view showing an example of an antireflection film included in an antireflection member according to the present invention. In this antireflection film, a transparent resin film is used as the transparent support 7, and the surface of the transparent support 7 is provided with a low refractive index layer 4 (the low refractive index layer 4 is a reflection according to the present invention) via a hard coat layer 8. It can be manufactured by forming (corresponding to a prevention film). In addition to the transparent resin film, a transparent resin plate can be used as the transparent support 7. In the antireflection member shown in FIG. 1, the low refractive index layer 4 is formed on one side of the transparent support 7 via the hard coat layer 8. The low refractive index layer 4 may be formed through the coat layer 8, and the low refractive index layer 4 may be directly formed on the surface of the transparent support 7 without using the hard coat layer 8. Also good. In the following, description will be made based on FIG.
[0035]
First, the transparent support 7 will be described. Examples of the transparent support 7 include transparent resin films or transparent resin plates made of various organic polymers. Usually, organic polymers used as optical members are polyolefin (polyethylene, polypropylene) from the viewpoint of optical properties such as transparency, refractive index, haze, and other physical properties such as impact resistance, heat resistance, and durability. Etc.), polyester (polyethylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon-66, etc.), polystyrene, polyvinyl chloride, polyimide, polyvinyl alcohol, ethylene vinyl alcohol, acrylic, cellulose (triacetyl) Cellulose, diacetylcellulose, cellophane, etc.), cycloolefin-based, or copolymers of these organic polymers, etc., and by forming these organic polymers into a film or plate, a transparent resin film or transparent A resin plate can be manufactured.
[0036]
In addition, using the above-mentioned organic polymer or the like containing known additives such as antistatic agents, ultraviolet absorbers, plasticizers, lubricants, colorants, antioxidants, flame retardants, etc. The transparent support 7 may be manufactured.
[0037]
Further, the transparent support 7 may be a single layer or a multilayer having a plurality of organic polymers laminated. The thickness of the transparent support 7 is not particularly limited, but is preferably 70 to 200 μm.
[0038]
Next, the hard coat layer 8 will be described. The hard coat layer 8 is formed by applying (coating) a hard coat material to the surface of the transparent support 7 and curing it before forming the low refractive index layer 4. When the hard coat layer 8 is formed between the transparent support 7 and the low refractive index layer 4, the surface hardness of the transparent support 7 is improved, and scratches caused by scratches with a load such as a pencil are prevented. Further, in the case of using a flexible transparent support 7 such as a transparent resin film, it is possible to suppress the occurrence of cracks in the antireflection film when the transparent support 7 is bent. It is possible to improve the mechanical strength.
[0039]
In order to obtain the above effects and to improve the hardness of the hard coat layer 8 itself, a reactive curable resin, that is, a thermosetting resin and / or an ionizing radiation curable resin is used as the hard coat material. Is desirable.
[0040]
As the thermosetting resin, for example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, silicon resin, polysiloxane resin, etc. can be used. . If necessary, a thermosetting resin to which a crosslinking agent, a polymerization initiator, a curing agent, a curing accelerator, and a solvent are added can also be used.
[0041]
As the ionizing radiation curable resin, a polymer mainly composed of a polyfunctional monomer containing two or more (meth) acryloyloxy groups in one molecule can be used. Polyfunctional monomers include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol (meth) acrylate, ethylene glycol (meth) acrylate, and triethylene glycol di (Meth) acrylate, tripropylene glycol (meth) acrylate, dipropylene glycol di (meth) acrylate, 3-methylpentanediol di (meth) acrylate, diethylene glycol bis β- (meth) acryloyloxypropionate, trimethylolethanetri ( (Meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (2-hydro (Ciethyl) isocyanate di (meth) acrylate, pentaerythritol tetra (meth) acrylate, nonaethylene glycol di (meth) acrylate, tetradecane ethylene glycol di (meth) acrylate, 10-decanediol (meth) acrylate, 2,2-bis ( Examples include 4- (meth) acryloyloxydiethoxyphenyl) propane, 1,4-bis ((meth) acryloyloxymethyl) cyclohexane, epoxy-modified bisphenol A di (meth) acrylate, and the like. Only one type of polyfunctional monomer may be used, or two or more types may be used in combination. If necessary, it can be copolymerized with a monofunctional monomer.
[0042]
In the polymerization reaction of the polyfunctional monomer, it is preferable to use a photopolymerization initiator. As the photopolymerization initiator, for example, acetophenones, benzophenones, α-amyloxime esters, thioxanthones and the like can be used. In addition to such a photopolymerization initiator, a photosensitizer may be used. As the photosensitizer, for example, n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone can be used. In the case of using a photopolymerization initiator, the photopolymerization reaction is preferably carried out by applying a hard coat material to the surface of the transparent support 7 and drying it, and then irradiating with ultraviolet rays.
[0043]
The hard coat layer 8 preferably has a refractive index close to that of the transparent support 7. If the film thickness of the hard coat layer 8 is 1 to 2 [mu] m or more, sufficient strength can be obtained. The range of 4-10 micrometers is preferable.
[0044]
It is also possible to form the hard coat layer 8 by using a hard coat material in which inorganic or organic fine particles (fillers) having an average particle diameter of 0.005 to 3 μm are mixed and dispersed. Furthermore, by making the surface state of the hard coat layer 8 uneven, a light diffusing treatment generally called anti-glare can be performed. In addition, said filler has a function which makes the hardness of the hard-coat layer 8 high, and suppresses the cure shrinkage of a polyfunctional monomer. The filler is not particularly limited as long as it is transparent, but specific examples of inorganic fine particles include silicon dioxide particles, titanium dioxide particles, zirconium oxide particles, aluminum oxide particles, tin oxide particles, calcium carbonate. Particles, talc, calcium sulfate particles, etc., and specific examples of organic fine particles include methacrylic acid-methyl acrylate copolymer particles, silicon resin particles, polystyrene particles, polyolefin particles, melamine particles, polyfluorinated ethylene particles, etc. Can be mentioned.
[0045]
The surface of the hard coat layer 8 is preferably subjected to the following surface treatment in addition to the above light diffusing treatment before the low refractive index layer 4 is formed. That is, examples of the surface treatment include physical surface treatment such as plasma discharge treatment, corona treatment, and flame treatment, and chemical surface treatment with a coupling agent, acid, and alkali. By performing such a surface treatment, the wettability and adhesion between the hard coat layer 8 and the low refractive index layer 4 can be improved.
[0046]
Next, the low refractive index layer 4 will be described. The low-refractive index layer 4 uses the first binder 3 containing the hollow fine particles 2 (which is also referred to as “first coating agent composition” hereinafter) as the surface of the hard coat layer 8 (or transparent). It is formed by coating (coating) on the surface of the support 7 and curing it. In the present invention, the second binder 6 (also this is added to the surface of the low refractive index layer 4). Since it can be used as a composition, it is hereinafter also referred to as “second coating agent composition”).
[0047]
In order to prevent reflection, the low refractive index layer 4 preferably has a refractive index of 1.20 to 1.50, more preferably 1.25 to 1.45. A method for adjusting the refractive index of the low refractive index layer 4 will be described later. The thickness (d) of the low refractive index layer 4 preferably satisfies the formula nd = λ / 4 (where λ is the wavelength) where n is the refractive index of the low refractive index layer 4. Specifically, d = 50 to 400 nm is preferable, and d = 50 to 200 nm is more preferable.
[0048]
FIG. 2 is a schematic cross-sectional view of the low refractive index layer 4 before applying the second coating agent composition, and FIG. 3 shows the low refractive index layer after applying the second coating agent composition. 4 is a schematic sectional view of 4 (that is, the antireflection film according to the present invention). As shown in FIG. 2, the low refractive index layer 4 is formed as a cured product of the first coating agent composition, and the substantially spherical hollow fine particles 2 are densely filled (high filling) in the low refractive index layer 4. And are bonded to each other by the first binder 3. The actual situation at this time is shown in FIG. FIG. 4 shows an electron micrograph (photographing magnification: 100,000 times) of the low refractive index layer 4 before applying the second coating agent composition. FIG. 4 confirms that the low refractive index layer 4 is formed on the surface of the hard coat layer 8 and that voids 5 exist between the hollow fine particles 2. And when the 2nd coating agent composition is apply | coated to the surface of this low-refractive-index layer 4, the 2nd binder 6 osmose | permeates the space | gap 5 between said hollow microparticles 2 which could not be filled only with the 1st binder 3. Then, as shown in FIG. 3, the antireflection film is manufactured by filling the gap 5 with the second binder 6. The actual state at this time is shown in FIG. FIG. 5 shows an electron micrograph (imaging magnification: 100,000 times) of the low refractive index layer 4 after applying the second coating agent composition. FIG. 5 confirms that the second binder 6 is densely filled in the gaps 5 between the hollow fine particles 2. That is, the antireflection film according to the present invention has a structure in which the bond between the hollow fine particles 2 inside the cured product is reinforced by the second binder 6 based on the cured product of the first coating agent composition. Yes. Hereinafter, the first binder 3 and the hollow fine particles 2 constituting the first coating agent composition and the second binder 6 constituting the second coating agent composition will be described in detail.
[0049]
First, the first binder 3 will be described. The first binder 3 may be a silicon alkoxide type or a polymer (UV curable resin, thermosetting resin) having a saturated hydrocarbon or polyether as a main chain. Moreover, you may contain the unit containing a fluorine atom in it. Specifically, it is a fluorine-containing compound (fluorine-containing surfactant, fluorine-containing polymer, fluorine-containing ether, fluorine-containing silane compound, etc.) described later.
[0050]
Of the first binders 3 described above, silicon alkoxides are SiO 2.₂Silicon alkoxide used for the formation of sol, a preferred example of which is R_mSi (OR ')_nIt is a compound represented by these. R and R ′ represent an alkyl group having 1 to 10 carbon atoms, m + n is 4, and m and n are each an integer. More specifically, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetra Pentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyl Tripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane Dimethyl butoxysilane, methyl dimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane and the like.
[0051]
The silicon alkoxide is hydrolyzed by dissolving the silicon alkoxide in a suitable solvent. Examples of the solvent used include alcohols such as methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate and butyl acetate, ketones, esters, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, Alternatively, a mixture thereof can be mentioned. The silicon alkoxide is SiO generated as a result of 100% hydrolysis and condensation of silicon alkoxide in the solvent.₂It dissolves so that it may become 0.1 weight% or more in conversion, Preferably it will be 0.1-30 weight%. SiO₂If the concentration of the sol is less than 0.1% by weight, the formed sol film cannot sufficiently exhibit the desired characteristics, while if it exceeds 30% by weight, it becomes difficult to form a transparent homogeneous film. Moreover, in this invention, if it is less than the above solid content, it is also possible to use other organic substance and an inorganic binder together.
[0052]
The UV curable resin of the first binder 3 is composed of the following binder polymer and photopolymerization initiator.
[0053]
That is, the binder polymer is a polymer having a saturated hydrocarbon or polyether as the main chain, and is preferably a polymer having a saturated hydrocarbon as the main chain. The binder polymer is preferably crosslinked. The polymer having a saturated hydrocarbon as the main chain is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer. In order to obtain a crosslinked binder polymer, it is preferable to use a monomer having two or more ethylenically unsaturated groups. Examples of monomers having two or more ethylenically unsaturated groups include esters of polyhydric alcohols and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-dichlorohexane diacrylate, pentaerythritol). Tetra (meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate , Pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and its derivatives (e.g., , 4-divinylbenzene, 4-vinylbenzoic acid-2-acryloyl ethyl ester, 1,4-divinyl cyclohexanone), vinyl sulfones (e.g., divinyl sulfone), acrylamides (e.g., include methylenebisacrylamide) and methacrylamide. The polymer having a polyether as the main chain is preferably synthesized by a ring-opening polymerization reaction of a polyfunctional epoxy compound.
[0054]
In place of or in addition to the monomer having two or more ethylenically unsaturated groups, a crosslinked structure may be introduced into the binder polymer by reaction of a crosslinkable group. Examples of the crosslinkable functional group include an isocyanate group, an epoxy group, an aziridine group, an oxazoline group, an aldehyde group, a carbonyl group, a hydrazine group, a carboxyl group, a methylol group, and an active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. In the present invention, the cross-linking group is not limited to the above compound, and may be one that exhibits reactivity as a result of decomposition of the functional group.
[0055]
The polymerization initiator used for the polymerization reaction and crosslinking reaction of the binder polymer is a photopolymerization initiator as described above. Examples of photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds , Fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone is included. Examples of benzoins include benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
[0056]
As the fluorine-containing compound, it is preferable to use a fluorine-containing surfactant, a fluorine-containing polymer, a fluorine-containing ether, a fluorine-containing silane compound, or the like.
[0057]
As the fluorine-containing surfactant, the hydrophilic part may be any of anionic, cationic, nonionic and amphoteric. In the fluorine-containing surfactant, part or all of the hydrocarbon hydrogen atoms constituting the hydrophobic portion are substituted with fluorine atoms. The fluorine-containing polymer is preferably synthesized by a polymerization reaction of an ethylenically unsaturated monomer containing a fluorine atom. In a polymer formed by polymerizing a monomer having a fluorine atom, specific examples of the monomer unit include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro -2,2-dimethyl-1,3-dioxole, etc.), partially or fully fluorinated alkyl ester derivatives of (meth) acrylic acid, fully or partially fluorinated vinyl ethers, perfluoropolyether and derivatives thereof, etc. One or a plurality of monomers can be combined at any ratio from these to obtain the desired polymer by copolymerization. Moreover, you may use the copolymer of the said fluorine-containing monomer and the monomer which does not contain a fluorine atom as a fluorine-containing polymer. The monomer unit that can be used in combination is not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, acrylic) Ethyl acetate, 2-ethylhexyl acrylate), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.) ), Vinyl ethers (such as methyl vinyl ether), vinyl esters (such as vinyl acetate, vinyl propionate, vinyl cinnamate), acrylamides (such as N-tertbutylacrylamide, N-cyclohexylacrylamide) Methacrylamides, and acrylonitrile derivatives. In addition, it is also preferable to introduce polyorganosiloxane in the fluoropolymer for imparting slipperiness. This can be obtained, for example, by polymerization of a polyorganosiloxane having an acryl group, a methacryl group, a vinyl ether group, a styryl group or the like at the terminal and the above monomer. A commercially available material can also be used as the fluoropolymer. Specific examples of commercially available fluoropolymers include Cytop (Asahi Glass), Teflon (registered trademark) AF (DuPont), polyvinylidene fluoride, Lumiflon (Asahi Glass), Opstar (JSR), etc. Is mentioned.
[0058]
The fluorine-containing ether is a compound generally used as a lubricant. Examples of the fluorinated ether include perfluoropolyether and derivatives thereof. Specifically, “Crytox” manufactured by DuPont Co., Ltd., “Demnam” manufactured by Daikin Industries, Ltd., “Vomblin” manufactured by Augmont, and the like. Moreover, it is also preferable to have a carboxyl group, a hydroxy group, an amino group, an isocyanate group, an alkoxysilyl group, an ethylenically unsaturated group (acryloyl, methacryloyl, allyl, vinyl ether, etc.) at the terminal of these perfluoropolyethers. Specific examples of the fluorine-containing silane compound include a silane compound containing a perfluoroalkyl group, such as (heptadecafluoro-1,2,2,2-tetradecyl) triethoxysilane, and “KBM-7803” as a commercially available product. "KP-801M" (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.
[0059]
In addition, the material which comprises said 1st binder can be used as a material which comprises a 2nd binder. That is, the first binder and the second binder may be made of the same material or different materials.
[0060]
  Next, the hollow fine particles 2 will be described. The hollow fine particles 2 are substantially spherical fine particles having a cavity 1 inside as shown in FIGS. 2 and 3, and the hollow fine particles 2 themselves have a low refractive index (for example, refractive index: 1.20 to 1.45). have. Specific examples include hollow silica fine particles. Since the cavity 1 is completely surrounded by the substantially spherical outer shell 9, foreign matters such as the first binder 3 and the second binder 6 do not enter the cavity 1. This is confirmed by FIG. 4 and FIG. The presence of the cavity 1 can reduce the refractive index, and the entry of foreign matter into the cavity 1 can be prevented to prevent an increase in the refractive index. Thus, an antireflection effect can be obtained. Porous fine particles formed by providing a plurality of cavities 1 in one fine particleTheFor use with hollow fine particles 2AndAlso good.
[0061]
Specifically, in order to reduce the refractive index of the low refractive index layer 4, the following may be performed. That is, hollow fine particles 2 with a low refractive index (for example, refractive index: 1.20 to 1.45) are added to the first binder 3 to prepare a first coating agent composition. Thus, the low refractive index layer 4 may be formed. Then, the cavity 1 is secured in the low refractive index layer 4 by the hollow fine particles 2, and the refractive index can be lowered by the cavity 1, and the function as an antireflection film can be realized.
[0062]
Here, it is preferable to use the hollow fine particles 2 having a refractive index of 1.2 to 1.45 and an average particle diameter of 0.5 to 200 nm. The refractive index of the hollow fine particles 2 is preferably as low as possible, but 1.2 is a practical lower limit. If it exceeds 1.45, there is a possibility that a sufficient antireflection function cannot be obtained. Further, when the average particle diameter of the hollow fine particles 2 is larger than 200 nm, light may be irregularly reflected by Rayleigh scattering in the manufactured antireflection film, and the antireflection film may appear whitish, and the transmittance may be reduced. On the contrary, when the average particle diameter of the hollow fine particles 2 is smaller than 0.5 nm, the dispersibility of the hollow fine particles 2 is lowered, and there is a possibility that aggregation occurs in the first coating agent composition.
[0063]
Furthermore, the hollow fine particles 2 (including the internal cavity 1) having the above refractive index and average particle diameter occupy 40 to 95% by volume of the entire low refractive index layer 4, and the first binder 3 and the second binder 2. It is preferable that the gap 5 between the binder 6 and the hollow fine particles 2 occupy the remaining 60 to 5% by volume (the invention of claim 2). In general, the maximum volume fraction of fine particles when close-packed with spherical particles having the same particle size (completely monodisperse) is 0.74 according to the Horsfield packing model. Inevitably, a 26 volume% intergranular gap is generated. Therefore, ideally, when the hollow fine particles 2 (assuming all the particle diameters are equal) occupy 74% by volume and the first binder 3 occupies the remaining 24% by volume in the first coating agent composition, All the voids 5 between the hollow fine particles 2 are replaced with the first binder 3 in the low refractive index layer 4, and a highly filled and very dense low refractive index layer 4 is obtained. However, in reality, the hollow fine particles 2 have a particle size distribution, and lack of wettability at the interface between the hollow fine particles 2 / first binder 3 and the nano-sized particle size cause aggregation in the first coating agent composition. Has occurred. Actually, when the amount of the hollow fine particles 2 added in the first coating agent composition is 40% by volume or more, the hollow fine particles 2 are filled in the low refractive index layer 4 formed by the first coating agent composition. A defect occurs, and voids 5 resulting from the unfilling of the first binder 3 are generated between the hollow fine particles 2. If the hollow fine particles 2 are less than 40% by volume, the hollow fine particles 2 can be filled with the first binder 3 and simultaneously the gaps 5 between the hollow fine particles 2 can be filled. There is a possibility that a low refractive index cannot be achieved due to the small amount.
[0064]
As described above, the voids 5 between the hollow fine particles 2 in the low refractive index layer 4 generated by the high filling (40% by volume or more) of the hollow fine particles 2 are the strength and wear resistance of the low refractive index layer 4. The performance will be significantly reduced. That is, the conventional method for reducing the refractive index of the low refractive index layer 4 by adding the hollow fine particles 2 having a low refractive index is a trade-off completely with wear resistance when the hollow fine particles 2 of 40 volume% or more are used. This makes it difficult to use practically. And in order to solve this trade-off problem, the present inventor is a method of filling the gap 5 between the hollow fine particles 2 in the low refractive index layer 4 with the second binder 6 when the hollow fine particles 2 are highly filled. Was invented.
[0065]
When the hollow fine particles 2 (including the internal cavities 1) exceed 95% by volume of the entire low refractive index layer 4, the amount of the first binder 3 or the like that bonds the hollow fine particles 2 is relative. There is a risk that the hollow fine particles 2 cannot be sufficiently bonded and held. Therefore, the upper limit of the volume occupied by the hollow fine particles 2 is 95% by volume of the entire low refractive index layer 4. Then, the volume other than the volume occupied by the hollow fine particles 2 is 60 to 5% by volume of the entire low refractive index layer 4. This volume is preferably occupied only by the first binder 3 and the second binder 6 (that is, there are no voids 5 between the hollow fine particles 2), but in reality, the voids 5 between the hollow fine particles 2 are very small. There may be a slight remaining. However, since the second binder 6 is present in a large portion between the hollow fine particles 2, the very few voids 5 between the hollow fine particles 2 do not cause a decrease in wear resistance.
[0066]
Further, as shown in FIG. 3, in the low refractive index layer 4 after applying the second coating agent composition, the cavities 1 in the hollow fine particles 2 and the voids 5 between the hollow fine particles 2 are in the low refractive index layer 4. It is preferable that the second binder 6 occupies 10 to 60% by volume and 40% by volume or more (the upper limit is less than 100% by volume) of the entire space 5 between the hollow fine particles 2 (the invention of claim 3). . In particular, in the low refractive index layer 4 shown in FIG. 3, the first and second coating agent compositions are completely filled in the voids 5 between the hollow fine particles 2, and the cavity 1 in the hollow fine particles 2 has a low refractive index. 10 to 60% by volume in the layer 4 is occupied. This cavity 1 can obtain a higher refractive index effect. In FIG. 3, as described above, the first and second coating agent compositions are completely filled in the gaps 5 between the hollow fine particles 2, but may not be completely filled. In this case, air exists in the gap 5, and thus the refractive index can be lowered by the gap 5 in which air exists. Moreover, about the low refractive index layer 4 shown in FIG. 3, the 2nd binder 6 occupies 40 volume% or more of the whole space | gap 5 between the hollow microparticles 2 with which the 1st, 2nd coating agent composition was filled. . By filling the gap 5 between the hollow fine particles 2 with the second binder 6 at such a ratio, the bond between the hollow fine particles 2 can be further reinforced and the wear resistance can be improved.
[0067]
As described above, the effect of reducing the refractive index of the low refractive index layer 4 can be obtained by including air (void 5) in the low refractive index layer 4. However, conventionally, an attempt has been made to reduce the refractive index by providing voids 5 between fine particles and allowing air to exist there. Therefore, the bond between the fine particles is weakened, and the wear resistance of the low refractive index layer 4 is remarkably lowered. This has been confirmed. Therefore, the voids 5 in the low refractive index layer 4 are formed by the cavities 1 inside the fine particles such as the hollow fine particles 2 and the porous fine particles, as in the present invention, as compared with the conventional technique. A reduction as much as possible is preferable in order to achieve both a low refractive index and wear resistance. Here, in preparing the first coating agent composition, if the amount of the hollow fine particles 2 added is increased, the amount of the cavities 1 is increased accordingly, and many cavities 1 are formed in the low refractive index layer 4. It can be introduced, and the refractive index can be further lowered to improve the antireflection performance. In the following description, the term “the void 5 ratio in the low refractive index layer 4” may be used. This means that the volume of the low refractive index layer 4 after applying the second coating agent composition is hollow. It means the proportion of the volume occupied by the voids 1 between the fine particles 2 and the voids 5 between the hollow fine particles 2.
[0068]
As described above, in the low refractive index layer 4 after applying the second coating agent composition, the cavities 1 in the hollow fine particles 2 and the voids 5 between the hollow fine particles 2 are 10 to 10 in the low refractive index layer 4. It is said that it occupies 60% by volume, in other words, the void ratio 5 in the low refractive index layer 4 is preferably 10 to 60% by volume for the following reason. That is, when the void ratio 5 in the low refractive index layer 4 is less than 10% by volume, the refractive index reduction effect may not be obtained. Conversely, the void ratio 5 in the low refractive index layer 4 may be obtained. Is more than 60% by volume, the hollow microparticles 2 and the porous microparticles having a very large volume of the cavity 1 are necessary, and the mechanical strength and the like of these microparticles themselves are lowered, which is not preferable in practice. is there.
[0069]
Of the voids 5 between the hollow fine particles 2, the voids 5 not filled with the first and second coating agent compositions are less than 60% by volume (thus filling the first and second coating agent compositions). The void 5 is preferably 40% by volume or more. When the void 5 containing air is 60% by volume or more of the entire void 5 between the hollow fine particles 2 as described above, the entire low refractive index layer 4 becomes porous and wear resistance may be reduced.
[0070]
In addition, one or more types of hollow fine particles 2 are used, and at least one of them is a hollow silica sol (SiO 2).₂) Is preferable (Invention of Claim 4). This is because the effect of reducing the refractive index of the low refractive index layer 4 can be further enhanced.
[0071]
As described above, the hollow fine particle 2 is a fine particle having the cavity 1 surrounded by the outer shell 9. The refractive index of the hollow fine particles 2 itself is preferably 1.20 to 1.45, and the refractive index of the hollow fine particles 2 is determined by a method disclosed in Japanese Patent Laid-Open No. 2001-233611 (Patent Document 11). Can be measured. Moreover, it is preferable that the average particle diameter of the hollow microparticles 2 is 0.5-200 nm. The material constituting the outer shell 9 of the hollow fine particle 2 is preferably a metal oxide in addition to silica. The hollow fine particles 2 are preferably those having a thickness of the outer shell 9 smaller than the average particle diameter, and the volume of the hollow silica fine particles (including the internal cavity 1) in the low refractive index layer 4 is also preferable. A large amount (40% by volume or more) is preferable. Such hollow fine particles 2 are disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-233611 (Patent Document 11), and the hollow fine particles 2 disclosed therein are used when preparing the first coating agent composition. can do.
[0072]
Specifically, the material constituting the outer shell 9 of the hollow fine particle 2 is SiO 2₂, SiO_xTiO₂TiO_x, SnO₂, CeO₂, Sb₂O₅, ITO, ATO, Al₂O₃A material in the form of a single material such as or a mixture of any combination of these materials. Further, a composite oxide of any combination of these materials may be used. In addition, SiO_xWhen firing in an oxidizing atmosphere, SiO₂Is preferred.
[0073]
  In addition, n kinds of hollow fine particles 2 having average particle diameters of d1, d2,..., Dn (where d1> d2>...> Dn) are mixed and used, and hollow fine particles having an average particle diameter of dk-1. 2 and hollow fine particles 2 having an average particle diameter of dk are dk <0.5 × dk−1 (k =2˜n, 2 ≦ n). In this way, when a plurality of types (n types, n is an integer satisfying n ≧ 2) of hollow fine particles 2 having different average particle sizes (particle size distributions) are mixed and used, the various hollow fine particles 2 are average particle sizes. If the average particle diameters dk and dk-1 of the two adjacent types of hollow fine particles 2 are in the above relationship, the hollow fine particles 2 having the average particle diameter dk have the average particle diameter dk-1. The gap between the hollow fine particles 2 is filled, and the maximum volume fraction of the hollow fine particles 2 composed of a plurality of types is increased. That is, the volume occupied by the voids 5 between the hollow fine particles 2 in the low refractive index layer 4 is reduced. Accordingly, by reducing the amount of the gap 5 to be filled with the first and second coating agent compositions, it is possible to prevent unfilling and maintain wear resistance, and to use hollow fine particles instead of the gap 5. By providing the two cavities 1, the refractive index can be further reduced. In addition, if the average particle diameters dk and dk-1 of two types of adjacent hollow microparticles 2 are dk ≧ 0.5 × dk−1 contrary to the above relationship, the hollow microparticles having an average particle diameter dk 2 may be difficult to be filled in the gaps between the hollow fine particles 2 having an average particle diameter dk-1.
[0074]
  Moreover, it is preferable that the 1st binder 3 consists of a reactive organosilicon compound (silicon alkoxide).6Invention). In particular, when hollow silica fine particles are used as the hollow fine particles 2 constituting the low refractive index layer 4, when a reactive organic silicon compound is used as the first binder 3, wettability and dispersibility with the hollow silica fine particles are good. It will be. Therefore, the workability is improved and the first binder 3 and the hollow fine particles 2 are uniformly mixed, so that in the low refractive index layer 4 shown in FIG. This eliminates the weakening of the bond between the hollow fine particles 2.
[0075]
Here, the reactive organosilicon compound is SiO₂Silicon alkoxide used for the formation of sol, a preferred example of which is R_mSi (OR ')_nIt is a compound represented by these. R and R ′ represent an alkyl group having 1 to 10 carbon atoms, m + n is 4, and m and n are each an integer. More specifically, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetra Pentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyl Tripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane Dimethyl butoxysilane, methyl dimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane and the like.
[0076]
The silicon alkoxide is hydrolyzed by dissolving the silicon alkoxide in a suitable solvent. Examples of the solvent used include alcohols such as methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate and butyl acetate, ketones, esters, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, Alternatively, a mixture thereof can be mentioned. The silicon alkoxide is SiO generated as a result of 100% hydrolysis and condensation of silicon alkoxide in the solvent.₂It dissolves so that it may become 0.1 weight% or more in conversion, Preferably it will be 0.1-30 weight%. SiO₂If the sol concentration is less than 0.1% by weight, the formed sol film cannot sufficiently exhibit the desired characteristics, while if it exceeds 30% by weight, it becomes difficult to form a transparent homogeneous film. Moreover, in this invention, if it is less than the above solid content, it is also possible to use other organic substance and an inorganic binder together.
[0077]
  The second binder 6 is preferably made of a reactive organosilicon compound.7Invention). In particular, when hollow silica fine particles are used as the hollow fine particles 2 constituting the low refractive index layer 4, when a reactive organic silicon compound is used as the second binder 6, the wettability with the hollow silica fine particles is improved, and the hollow silica fine particles 2 are formed. The second coating agent composition can easily enter the voids 5 between the fine particles.
[0078]
Here, the reactive organosilicon compound is SiO₂Silicon alkoxide used for the formation of sol, a preferred example of which is R_mSi (OR ')_nIt is a compound represented by these. R and R ′ represent an alkyl group having 1 to 10 carbon atoms, m + n is 4, and m and n are each an integer. More specifically, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetra Pentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyl Tripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane Dimethyl butoxysilane, methyl dimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane and the like.
[0079]
The silicon alkoxide is hydrolyzed by dissolving the silicon alkoxide in a suitable solvent. Examples of the solvent used include alcohols such as methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate and butyl acetate, ketones, esters, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, Alternatively, a mixture thereof can be mentioned. The silicon alkoxide is SiO generated as a result of 100% hydrolysis and condensation of silicon alkoxide in the solvent.₂It dissolves so that it may become 0.1 weight% or more in conversion, Preferably it will be 0.1-30 weight%. SiO₂If the sol concentration is less than 0.1% by weight, the formed sol film cannot sufficiently exhibit the desired characteristics, while if it exceeds 30% by weight, it becomes difficult to form a transparent homogeneous film. Moreover, in this invention, if it is less than the above solid content, it is also possible to use other organic substance and an inorganic binder together.
[0080]
  The contact angle of the second binder 6 with respect to the low refractive index layer 4 is preferably 0 to 70 ° (claims).5Invention). This contact angle means the following. That is, the first coating agent composition is applied (coated) to the surface of the hard coat layer 8 (or the surface of the transparent support 7) and cured to cure the low refractive index layer 4 as shown in FIG. And the contact angle measured when the second coating agent composition (that is, the second binder 6) is dropped onto the surface of the low refractive index layer 4. And when said contact angle is 0-70 degrees, the 2nd binder 6 penetrate | invades easily into the space | gap 5 between the hollow fine particles 2 in the low-refractive-index layer 4, and manufactures an antireflection film as a precise | minute thin film. It is something that can be done. However, when the contact angle exceeds 70 °, it is difficult to obtain such an effect.
[0081]
  Moreover, it is preferable that the molecular weight (weight average molecular weight) of the 2nd binder 6 is 100-5000.8Invention). If the molecular weight of the second binder 6 is less than 100, there is a possibility that it will not stay in the void 5 due to a decrease in viscosity, and it may be difficult to cure, and conversely, the molecular weight of the second binder 6 exceeds 5000. Then, it becomes difficult to enter the gap 5 between the hollow fine particles 2 in the low refractive index layer 4, and the antireflection film may not be manufactured as a dense thin film.
[0082]
  The second binder 6 preferably contains a curing catalyst (crosslinking agent).9Invention). As a result, when the first coating agent composition is applied (coated) to the surface of the hard coat layer 8 (or the surface of the transparent support 7) and dried, the condensation reaction is promoted to reduce the low refractive index layer. The crosslink density in 4 becomes high, and the water resistance and alkali resistance of the low refractive index layer 4 can be improved. In order to obtain such an effect, a metal chelate compound (for example, a Ti chelate compound or a Zr chelate compound), an organic acid, or the like can be used as the curing catalyst. Among these curing catalysts, the metal chelate compound is particularly effective when used in preparing the first coating agent composition using tetrafunctional alkoxysilane as a raw material.
[0083]
Moreover, it is preferable to use organic zirconium as the curing catalyst. This is because the above-described effects can be further enhanced. The organic zirconium is not particularly limited. For example, the general zirconium ZrO_nR² _m(OR¹)_p(M and p are integers of 0 to 4, n is 0 or 1, 2n + m + p = 4). An alkoxyl group (OR¹) Functional group (R¹) Is not particularly limited as long as it is a monovalent hydrocarbon group, but is preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms. Specifically, alkyl groups, such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a peptyl group, an octyl group, can be illustrated. R²For example, C₅H₇O₂(Acetylacetonate complex) and C₆H₉O₃(Ethyl acetoacetate complex). R¹And R²May be the same or different in one molecule. Especially as organic zirconium, Zr (OC₄H₉)₄, Zr (OC₄H₉)₃(C₅H₇O₂) And Zr (OC₄H₉)₂(C₅H₇O₂) (C₆H₉O₃), The mechanical strength of the low refractive index layer 4 can be further improved. For example, the low refractive index layer 4 is formed using the first coating agent composition having a small ratio of a silicone resin obtained by condensing a (poly) siloxane compound, for example, a tetrafunctional hydrolyzable alkoxysilane, to the hollow silica fine particles. When formed, the mechanical strength of the low refractive index layer 4 may be insufficient, but the mechanical strength of the low refractive index layer 4 can be improved by adding organic zirconium. In addition, after applying (coating) the first coating agent composition to the surface of the hard coat layer 8 (or the surface of the transparent support 7), it is heat-treated at a relatively low temperature (for example, 100 ° C.). The obtained low refractive index layer 4 has the same strength as when heat-treated at a high temperature (for example, 300 ° C.) when no organic zirconium is added. That is, if organic zirconium is added, heat treatment can be performed at a low temperature, and energy consumption can be suppressed.
[0084]
The amount of organic zirconium added is ZrO.₂Solid content in the first coating composition in terms of conversion (for example, SiO in the case of tetrafunctional silicone alkoxide)₂) It is preferably 0.1 to 10% by weight based on the total amount. If the amount of organic zirconium added is less than 0.1% by weight, the above effect due to organic zirconium may not be obtained. Conversely, if the amount of organic zirconium added exceeds 10% by weight, the first coating The agent composition may be gelled or aggregated.
[0085]
  Further, in order to impart antifouling property to the low refractive index layer 4, a part or all of the second binder 6 may be replaced with a water and oil repellent material. As the water- and oil-repellent materials, generally, wax-based materials and the like can be mentioned, and it is particularly preferable that the second binder 6 contains a fluorine-containing compound.0Invention). In this way, after the second coating agent composition is applied and dried, the surface of the low refractive index layer 4 is protected from dirt by the fluorine-containing compound remaining on the surface of the low refractive index layer 4. In addition, even if dirt is attached, the dirt can be easily removed. Furthermore, the frictional resistance of the surface of the low refractive index layer 4 can be reduced, and the effect of improving the wear resistance can be obtained.
[0086]
  Conventionally, when the surface of the low refractive index layer 4 is subjected to antifouling treatment, a monomolecular layer of a fluorine-containing compound is chemically bonded to the surface of the low refractive index layer 4 and laminated. . Therefore, even though the antifouling property is excellent, there are problems in the mechanical strength, aging characteristics, etc. of the monomolecular layer itself of the fluorine-containing compound. However, for example, when the second binder 6 is made of a reactive organosilicon compound (claims)7In the present invention, the fluorine-containing compound and the reactive organic silicon compound undergo a crosslinking reaction so that the fluorine-containing compound is incorporated into the second binder 6 and the surface of the low refractive index layer 4 is obtained. Therefore, it is possible to produce an antireflection film having little anti-fouling effect over time and excellent mechanical strength.
[0087]
Examples of the fluorine-containing compound include those represented by the general formula R ′_mSi (OR)_4-m(Where R ′ is a fluorine-containing substituent, R is an alkyl group, and m is the number of substitutions) (m = 1 to 4). Specifically, CF₃(CH₂)₂Si (OCH₃)₃, CF₃CF₂(CH₂)₂Si (OCH₃)₃, CF₃(CF₂)₂(CH₂)₂Si (OCH₃)₃, CF₃(CF₂)₃(CH₂)₂Si (OCH₃)₃, CF₃(CF₂)₄(CH₂)₂Si (OCH₃)₃, CF₃(CF₂)₅(CH₂)₂Si (OCH₃)₃, CF₃(CF₂)₆(CH₂)₂Si (OCH₃)₃, CF₃(CF₂)₇(CH₂)₂Si (OCH₃)₃, CF₃(CF₂)₈(CH₂)₂Si (OCH₃)₃, CF₃(CF₂)₉(CH₂)₂Si (OCH₃)₃, CF₃(CH₂)₂Si (OC₂H₅)₃, CF₃CF₂(CH₂)₂Si (OC₂H₅)₃, CF₃(CF₂)₂(CH₂)₂Si (OC₂H₅)₃, CF₃(CF₂)₃(CH₂)₂Si (OC₂H₅)₃, CF₃(CF₂)₄(CH₂)₂Si (OC₂H₅)₃, CF₃(CF₂)₅(CH₂)₂Si (OC₂H₅)₃, CF₃(CF₂)₆(CH₂)₂Si (OC₂H₅)₃, CF₃(CF₂)₇(CH₂)₂Si (OC₂H₅)₃, CF₃(CF₂)₈(CH₂)₂Si (OC₂H₅)₃, CF₃(CF₂)₉(CH₂)₂Si (OC₂H₅)₃Etc., and only one type of these may be used, or two or more types may be used in combination.
[0088]
  The second binder 6 preferably contains 0.1 to 50% by weight of the fluorine-containing compound.1Invention). The reason is that the antifouling property can be further enhanced. However, if the fluorine-containing compound is less than 0.1% by mass, the antifouling effect due to the fluorine-containing compound may not be sufficiently obtained. Conversely, if the fluorine-containing compound exceeds 50% by weight, the second The dispersibility of the fluorine-containing compound in the binder 6 (for example, a reactive organic silicon compound) is reduced, the crosslinking density of the cured product of the second binder 6 is reduced, or the second binder 6 with respect to the low refractive index layer 4 is reduced. If the wettability is reduced, both the film quality as an antireflection film and the wear resistance may be reduced.
[0089]
  It is preferable that the second binder 6 contains a silicone compound.2Invention). Even in this case, as in the case of the fluorine-containing compound, the surface of the low refractive index layer 4 can be protected from dirt, and even if dirt is attached, the dirt can be easily removed. It is. Furthermore, the frictional resistance of the surface of the low refractive index layer 4 can be reduced, and the effect of improving the wear resistance can be obtained.
[0090]
As said silicone compound, what is represented by the following [Chemical Formula 1] can be used. In [Chemical Formula 1], R¹Is a divalent hydrocarbon group having 2 to 10 carbon atoms, alkylene group such as ethylene group, propylene group, butylene group, hexylene group and octylene group, cycloalkylene group such as cyclohexylene group, and arylene group such as phenylene group And ethylene group, propylene group and phenylene group are particularly preferable. R²Are the same or different monovalent hydrocarbon groups having 1 to 10 carbon atoms, specifically, alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octyl, and decyl groups. Cycloalkyl groups such as cyclohexyl groups, vinyl groups, allyl groups, propenyl groups, butenyl groups, alkenyl groups such as hexenyl groups, aryl groups such as phenyl groups and tolyl groups, aralkyl groups such as benzyl groups and phenylethyl groups, etc. In particular, a methyl group, an ethyl group, a phenyl group, and a phenylethyl group are preferable.
[0091]
[Chemical 1]

[0092]
R³Is a hydrolyzable group represented by the following [Chemical Formula 2]. R⁶Is a divalent hydrocarbon group having 2 to 10 carbon atoms, and as the divalent hydrocarbon group, R¹The same thing is illustrated. R⁷Is a monovalent hydrocarbon group having 1 to 10 carbon atoms, R²Although the thing similar to is illustrated, it is preferable that it is a methyl group. a is 0, 1 or 2, preferably 0 or 1.
[0093]
[Chemical formula 2]

[0094]
In the above [Chemical Formula 1], R⁴Is a monovalent hydrocarbon group having 1 to 10 carbon atoms, R²The hydrogen atom bonded to the carbon atom may be partially or entirely substituted with a fluorine atom, and as such substituent, R¹The same thing is mentioned, A trifluoropropyl group etc. can be illustrated.
[0095]
In addition, R⁵Is R³Or R⁴Each R⁵May be the same or different from each other, but when n is 0, at least one R⁵Is R³It is. k is 0 to 100, preferably 0 to 60, m is 0 to 100, preferably 0 to 60, and n is 0 to 5. As described above, when n = 0, R⁵At least one of R³Therefore, the compound of the above [Chemical Formula 1] has at least one R in the molecule.³It is a siloxane containing (hydrolyzable group) and optionally having a fluoroalkyl group.
[0096]
  The second binder 6 preferably contains colloidal silica.3Invention). In this way, the second coating agent composition can easily enter the voids 5 between the hollow fine particles 2 in the low refractive index layer 4. Then, in the low refractive index layer 4 after the application of the second coating agent composition, air existing in the voids 5 between the hollow fine particles 2 is pushed out, and the bonds between the hollow fine particles 2 are bonded to the second coating agent. It is further reinforced by the composition, wear resistance is improved, and colloidal silica makes it possible to further reduce the refractive index. Here, as the colloidal silica, those having an average particle diameter of 0.5 to 100 nm are particularly preferable. If the average particle size is less than 0.5 nm, the dispersibility of the hollow fine particles 2 may be reduced. Conversely, if the average particle size exceeds 100 nm, the voids 5 between the hollow fine particles 2 may not be filled easily. is there.
[0097]
The colloidal silica itself may not have the cavity 1 inside. Even with such colloidal silica, the coexistence with the second binder 6 can improve the mechanical strength of the formed antireflection film, and also improve the surface smoothness and crack resistance. Because it can be done.
[0098]
The form of colloidal silica is not particularly limited, and may be, for example, a powder form or a sol form. When colloidal silica is used as a sol form, it is not particularly limited. For example, water-dispersed colloidal silica or colloidal silica dispersed in a hydrophilic organic solvent such as alcohol can be used. In general, such colloidal silica contains 20 to 50% by weight of silica as a solid content, and the amount of silica can be determined from this value.
[0099]
Here, when water-dispersed colloidal silica is used, water present in the colloidal silica as a component other than a solid content can be used for hydrolysis of a silane compound, for example, a tetrafunctional hydrolyzable organosilane. Therefore, it is necessary to add water of water-dispersible colloidal silica to the amount of water during the hydrolysis. Water-dispersible colloidal silica is usually made from water glass, and a commercially available product can be easily obtained and used.
[0100]
Further, the organic solvent-dispersed colloidal silica can be easily prepared by replacing the water of the water-dispersed colloidal silica with an organic solvent. Such an organic solvent-dispersed colloidal silica can also be easily obtained and used as a commercial product, like the water-dispersed colloidal silica. In the organic solvent-dispersed colloidal silica, the type of the organic solvent in which the colloidal silica is dispersed is not particularly limited. For example, lower fats such as methanol, ethanol, isopropanol (IPA), n-butanol, and isobutanol. Aromatic alcohols, ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol derivatives such as ethylene glycol monoethyl ether, diethylene glycol, diethylene glycol derivatives such as diethylene glycol monobutyl ether, and hydrophilic organic solvents such as diacetone alcohol, One or two or more selected from the group consisting of these can be used. Furthermore, in combination with these hydrophilic organic solvents, one or more of toluene, xylene, hexane, ethyl heptane acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can be used. .
[0101]
  The second binder 6 preferably contains fine particles having a refractive index of 1.2 to 1.45 and an average particle diameter of 0.5 to 100 nm.4Invention). The reason is that the fine particles having the above average particle diameter can be easily filled in the gaps 5 between the hollow fine particles 2 to reinforce the bond between the hollow fine particles 2 and further improve the wear resistance. This is because if the refractive index is low as described above, it is possible to further reduce the refractive index of the entire low refractive index layer 4 while maintaining wear resistance. Examples of the fine particles having the above refractive index and average particle diameter include porous silica sol, hollow silica sol, MgF₂A sol etc. can be illustrated. In addition, it is difficult to obtain fine particles having a refractive index smaller than 1.2. Conversely, if fine particles having a refractive index larger than 1.45 are used, the effect of lowering the refractive index may not be expected. If the average particle diameter of the fine particles is less than 0.5 nm, the dispersibility in the second coating agent composition may be reduced. Conversely, if the average particle diameter of the fine particles exceeds 100 nm, the low refractive index layer 4 It may be difficult to fill the voids 5 between the hollow fine particles 2 inside.
[0102]
  The second binder 6 preferably contains a hollow silica sol.5Invention). In this way, the wear resistance can be further improved and the refractive index of the entire low refractive index layer 4 can be further reduced. In addition, it is preferable that content of the hollow silica sol in a 2nd coating agent composition is 1-60 volume%. If it is less than 1% by volume, the effect of lowering the refractive index by the second coating agent composition may be small. Conversely, if it exceeds 60% by volume, the dispersibility of the hollow silica sol in the second coating agent composition may be low. There is a possibility that it becomes difficult to fill the voids 5 between the hollow fine particles 2 in the low refractive index layer 4.
[0103]
And in producing the anti-reflective film concerning this invention, it can carry out as follows. That is, the aforementioned first coating agent composition is applied (coated) to the surface of the hard coat layer 8 (or the transparent support 7) with a wire bar coater or the like. Next, this is dried and the hollow fine particles 2 are bonded to each other by the first binder 3, thereby forming a low refractive index layer 4 as shown in FIG. 2 (FIG. 4). Thereafter, the second coating agent composition is applied (coated) to the surface of the low refractive index layer 4 with a wire bar coater or the like. Then, by drying this, an antireflection film in which the second binder 6 is densely filled in the gaps 5 between the hollow fine particles 2 in the low refractive index layer 4 as shown in FIG. 3 (FIG. 5) is manufactured. It is something that can be done.
[0104]
In the antireflection film thus obtained, the hollow fine particles 2 having the cavity 1 inside are highly filled in the low refractive index layer 4, thereby sufficiently ensuring a low refractive index and preventing reflection. In addition, by filling the gap 5 between the hollow fine particles 2 with the second binder 6, the bond between the hollow fine particles 2 can be reinforced and the wear resistance can be improved.
[0105]
The first and second coating agent compositions can be applied by a general wet coating application method, such as a liquid phase method (dip coating method, spin coating method, spray coating method, roll coating method). , Gravure roll coating method, reverse coating method, transfer roll coating method, micro gravure coating method, cast coating method, calendar coating method, die coating method, etc.) ). In addition, after applying (coating) the first and second coating agent compositions, the solvent in the low refractive index layer 4 is volatilized by heating and drying, and then heating, humidification, ultraviolet irradiation, and electron beam irradiation are performed. Etc. to cure the low refractive index layer 4.
[0106]
【Example】
Hereinafter, the present invention will be specifically described by way of examples.
[0107]
The following were used as the transparent support (transparent resin film) and the hard coat material.
[0108]
Transparent resin film: PET film, “A4300” (188 μm thickness) manufactured by Toyobo Co., Ltd.
・ Hard coat material: Acrylic UV curable resin, “Seika Beam PET-HC15” manufactured by Dainichi Seika Kogyo Co., Ltd. (active ingredient 60%)
And after apply | coating said hard-coat material to the surface of said transparent resin film with wire bar coater # 10 and drying this at 40 degreeC for 1 minute, UV irradiation (1000mJ / cm²) And cured to form a hard coat layer.
[0109]
  (referenceExample 1)
  Add 356 parts of methanol to 208 parts of tetraethoxysilane ("parts" means "parts by weight", the same shall apply hereinafter), add 18 parts of water and 18 parts of 0.01N hydrochloric acid aqueous solution, and use a disper. To obtain a mixed solution. This mixture was stirred in a thermostatic bath at 25 ° C. for 2 hours to obtain a silicone resin (A) having a weight average molecular weight adjusted to 850.
[0110]
Next, hollow silica IPA (isopropanol) dispersion sol (solid content 20% by weight, average particle size 60 nm, manufactured by Catalytic Chemical Industry Co., Ltd.) was used as the low refractive index fine particles. The first coating agent composition is prepared by blending silica fine particles / silicone resin so that the volume ratio is 50/50 in terms of condensation solids, and then diluting with methanol so that the total solid content is 1%. did. The obtained sol liquid had a refractive index of 1.36.
[0111]
Next, the second coating agent composition was prepared by diluting the silicone resin (A) with methanol so that the total solid content was 0.5%.
[0112]
Then, the surface of the hard coat layer formed as described above was subjected to corona treatment, and first, the first coating agent composition was coated (applied) with a wire bar coater so as to have a film thickness of about 100 nm. Next, this was dried and cured at 100 ° C. for 1 hour to form a low refractive index layer. Thereafter, the surface of the low refractive index layer was coated (applied) with a wire bar coater so that the second coating composition was 50 nm in terms of solid content film thickness. And this was dried on 100 degreeC and the conditions for 1 hour, and the antireflection film was manufactured by hardening.
[0113]
  (referenceExample 2)
  referenceIn Example 1, except that the hollow silica fine particles / silicone resin of the first coating agent composition was blended so that the volume ratio was 90/10 in terms of condensed solids,referenceAn antireflection film was produced in the same manner as in Example 1.
[0114]
  (referenceExample 3)
  referenceIn Example 2, the second coating agent composition contains a thermosetting fluorine-containing polymer (“JN7215” manufactured by JSR Corporation), and becomes 0.5% by weight based on the total solid content of the second coating agent composition. Except for using the one diluted with MEK (methyl ethyl ketone)referenceAn antireflection film was produced in the same manner as in Example 2.
[0115]
  (referenceExample 4)
  referenceIn Example 1, hollow silica fine particles and silica fine particle methanol dispersion (solid content 30% by weight, average particle size 20 nm, manufactured by Nissan Chemical Industries, Ltd., methanol silica sol, refractive index as low refractive index fine particles in the first coating agent composition 1.46) except that the weight ratio is 8: 2referenceAn antireflection film was produced in the same manner as in Example 2.
[0116]
  (referenceExample 5)
  Zr (OC as an organic zirconium component (curing catalyst)₄H₉)₃(C₅H₇O₂), And this is used with respect to the total solid content of the second binder coating composition.₂Except for using a second binder coating composition containing 10% by weight in terms of solid content,referenceAn antireflection film was produced in the same manner as in Example 2.
[0117]
  (referenceExample 6)
  As the fluorosilane coupling agent (fluorine-containing compound), “TSL8233” (manufactured by GE Toshiba Silicone Co., Ltd.) blended so as to be 1% by weight with respect to the total solid content of the second coating agent composition was used. except,referenceAn antireflection film was produced in the same manner as in Example 2.
[0118]
  (referenceExample 7)
  As a fluorosilane coupling agent (fluorine-containing compound), “TSL8233” (manufactured by GE Toshiba Silicone Co., Ltd.) was used so as to be 40% by weight with respect to the total solid content of the second coating agent composition. except,referenceAn antireflection film was produced in the same manner as in Example 2.
[0119]
  (referenceExample 8)
  A mixture of methyl hydrogen silicone oil “TSW831” as a silicone oil (silicone compound) and a curing catalyst “CW80” (both manufactured by GE Toshiba Silicones Co., Ltd.) of 20% by weight with respect to the silicone oil as a curing catalyst is applied to the second coating. Except using what was mix | blended so that it might become 1 weight% with respect to the total solid of an agent composition,referenceAn antireflection film was produced in the same manner as in Example 2.
[0120]
  (referenceExample 9)
  Silica fine particle methanol dispersion (solid content 30% by weight, average particle size 20 nm, manufactured by Nissan Chemical Co., Ltd., methanol silica sol, refractive index 1.46) is used as the silica fine particle, and this is added to the silicone resin (A) and silica. The second coating agent composition is prepared by blending the fine particles / silicone resin so that the volume ratio is 50/50 in terms of condensed solids, and then diluting with methanol so that the total solid content is 0.5%. Obtained. The refractive index of the sol thus obtained was 1.36. And except using this second coating agent composition,referenceAn antireflection film was produced in the same manner as in Example 2.
[0121]
  (referenceExample 10)
  Hollow silica IPA (isopropanol) dispersion sol (solid content 20% by weight, average particle diameter 60 nm, manufactured by Catalyst Kasei Kogyo Co., Ltd.) was used as the low refractive index fine particle, and this was added to the silicone resin (A). The second coating agent composition obtained by blending the silicone resin so as to have a volume ratio of 50/50 in terms of condensation solid, and then diluting with methanol so that the total solid content is 0.5%, Other than usingreferenceAn antireflection film was produced in the same manner as in Example 2.
[0122]
  (Comparative Example 1)
  referenceOnly the first coating agent composition in Example 2 was coated (applied) with a wire bar coater so that the film thickness was about 100 nm. And this was dried on 100 degreeC and the conditions for 1 hour, and was made to harden, and the antireflection film was manufactured.
[0123]
  (Comparative Example 2)
  referenceInstead of the hollow silica fine particles in Example 2, normal silica fine particles (those without cavities inside) methanol dispersion (solid content 30% by weight, average particle size 20 nm, manufactured by Nissan Chemical Co., Ltd., methanol silica sol) are used as silica fine particles. / Except for blending so that the silicone resin has a volume ratio of 90/10 in terms of condensed solids,referenceAn antireflection film was produced in the same manner as in Example 2.
[0124]
  referenceFor Examples 1 to 10 and Comparative Examples 1 and 2, the void ratio in the low refractive index layer (the ratio of the volume occupied by the voids in the hollow fine particles and the voids between the hollow fine particles) was determined, and the void ratio in the low refractive index layer was further determined. The filling rate of the second coating agent composition was determined. The results are shown in Table 1. The porosity in the low refractive index layer and the filling rate of the second coating agent composition were calculated from the area fraction using an FE-SEM observation image of the cross section of the low refractive index layer (antireflection film).
[0125]
  AndreferenceFor the antireflection films of Examples 1 to 10 and Comparative Examples 1 and 2, the reflectance, contact angle, oil pen wiping property, fingerprint wiping property, wear resistance (steel wool test), and adhesion (cross cut tape test) were evaluated. did. The results are shown in Table 2. Various physical property evaluation methods are shown below.
[0126]
(A) Optical characteristics
Reflectance measurement: The surface of the transparent resin film (the lowermost surface in FIG. 1) was rubbed with sandpaper, and after applying a matte black paint, the reflectance of one side at an incident angle of 5 ° of light with a wavelength of 550 nm was measured. . For this measurement, “U-3400” manufactured by Hitachi, Ltd. was used.
[0127]
(B) Antifouling property
(B) -1 Contact angle measurement: Using a contact angle meter [CA-X type: manufactured by Kyowa Interface Science Co., Ltd.], a droplet having a diameter of 1.8 μl is needled in a dry state (20 ° C.-65% RH). A droplet was made by making it first and bringing it into contact with the surface of the low refractive index layer. The contact angle is an angle formed by the solid surface and the tangent to the liquid surface at the point where the solid and the liquid are in contact with each other, and is defined as the angle containing the liquid. Distilled water was used as the liquid.
[0128]
(B) -2 Wipeability of oil-based pen: The oil-based pen attached to the surface of the antireflection film was wiped off with a cellulose nonwoven fabric [Bencot M-3: manufactured by Asahi Kasei Co., Ltd.], and the ease of removal was visually determined. . Judgment criteria are shown below.
[0129]
“◯”: The oil-based pen can be completely wiped off.
[0130]
"△": A trace of wiping off the oil pen remains.
[0131]
“×”: The oil-based pen cannot be wiped off.
[0132]
(B) -3 Fingerprint wiping property: The fingerprint adhering to the surface of the antireflection film was wiped off with a cellulose nonwoven fabric [Bencot M-3: manufactured by Asahi Kasei Co., Ltd.], and the ease of removal was visually determined. Judgment criteria are shown below.
[0133]
“◯”: The fingerprint can be completely wiped off.
[0134]
“Δ”: A fingerprint wiping trace remains.
[0135]
"X": The fingerprint wipe mark spreads and cannot be wiped off.
[0136]
(C) Mechanical strength
(C) -1 Abrasion resistance: The surface of the antireflection film is made of steel wool [Bonster # 0000: manufactured by Nippon Steel Wool Co., Ltd.] at 250 g / cm.²And 500 g / cm²Were rubbed 10 times and visually judged for the presence or absence of scratches (steel wool test). Judgment criteria are shown below.
[0137]
“◯”: The scratch cannot be confirmed.
[0138]
“Δ”: Several scratches can be confirmed.
[0139]
“×”: Many scratches can be confirmed.
[0140]
(C) -2 Adhesiveness: After the surface of the antireflection film was cut at 100 points of 1 mm square, the presence or absence of peeling with an adhesive cellophane tape [Nichiban Co., Ltd., industrial 24 mm width cello tape (registered trademark)] was visually determined. (Cross cut tape peel test).
[0141]
[Table 1]

[0142]
[Table 2]

[0143]
  As seen in Table 1,referenceIt is confirmed that all of Examples 1 to 10 have a high porosity in the low refractive index layer and a high filling rate of the second binder. Therefore,referenceThe antireflection films of Examples 1 to 10 are considered to be excellent in both antireflection performance and wear resistance characteristics. On the other hand, although the thing of the comparative example 1 has a low porosity in a low refractive index layer, the filling rate of a 2nd binder is low, and the thing of the comparative example 2 has a high filling rate of a 2nd binder, but a low refractive index layer It is confirmed that the internal porosity is low. That is, it is considered that the antireflection film of Comparative Example 1 has poor wear resistance, and the antireflection film of Comparative Example 2 has poor antireflection performance.
[0144]
  The above items were verified by various physical property tests as shown in Table 2. In addition, fluorine-containing compounds and silicone compounds were used.referenceIt was demonstrated that the antireflection films of Examples 3 and 6 to 8 were excellent in antifouling properties.
[0145]
That is, as a result of the study by the present inventors, the antireflection film invented has a very low refractive index, excellent wear resistance, no peeling of the low refractive index layer, and fingerprints on the surface of the low refractive index layer, It is possible to prevent dirt such as sebum, oil-based magic, cosmetics and the like from being attached, and even if attached, it can be easily wiped off. By using such an antireflection film, it is considered that light reflection on the display surface of an image display device or the like can be remarkably prevented.
[0146]
【The invention's effect】
  As described above, the antireflective film according to claim 1 of the present invention contains substantially spherical fine particles having one cavity therein, and the hollow fine particles are completely surrounded by the substantially spherical outer shell. Since the second binder is filled in the voids between the hollow fine particles in the low refractive index layer formed by bonding with one binder, the hollow fine particles having cavities therein are highly filled in the low refractive index layer. Therefore, it is possible to prevent reflection by sufficiently securing a low refractive index. Also, by filling the voids between the hollow fine particles with the second binder, the bonding between the hollow fine particles is reinforced to withstand the damage. Abrasion can be improved.
  Further, n kinds of hollow fine particles having average particle diameters of d1, d2,..., Dn (where d1> d2>...> Dn) are used in combination, and hollow fine particles having an average particle diameter of dk-1 are used. Hollow fine particles having an average particle diameter of dk are dk <0.5 × dk−1 (k =2˜n, 2 ≦ n), the hollow fine particles having the average particle diameter dk are filled in the gaps between the hollow fine particles having the average particle diameter dk−1, and the maximum volume fraction of the plural kinds of hollow fine particles is increased. To do.
[0147]
In the invention of claim 2, the hollow fine particles having a refractive index of 1.2 to 1.45 and an average particle diameter of 0.5 to 200 nm are used, and the hollow fine particles including the internal cavity have a low refractive index. Since the entire layer occupies 40 to 95% by volume, and the voids between the first binder, the second binder and the hollow fine particles occupy the remaining 60 to 5% by volume, the antireflection function by lowering the refractive index can be further enhanced. In addition, the wear resistance can be further improved.
[0148]
Further, in the invention of claim 3, cavities in the hollow fine particles and voids between the hollow fine particles occupy 10 to 60% by volume in the low refractive index layer, and the second binder is 40% by volume of the whole voids between the hollow fine particles. Therefore, the antireflection function by lowering the refractive index can be further enhanced, and the wear resistance can be further improved.
[0149]
In the invention of claim 4, since one or more kinds of hollow fine particles are used and at least one of them is a hollow silica sol, the effect of reducing the refractive index of the low refractive index layer can be further enhanced. Is.
[0151]
  And claims5In this invention, since the contact angle of the second binder to the low refractive index layer is 0 to 70 °, the second binder easily penetrates into the voids between the hollow fine particles in the low refractive index layer, and the antireflection film is densely formed. It can be manufactured as a thin film.
[0152]
  And claims6In the invention, since the first binder is made of a reactive organosilicon compound, the wettability and dispersibility with the hollow fine particles are improved.
[0153]
  And claims7In the invention, since the second binder is made of a reactive organosilicon compound, the wettability with the hollow fine particles is improved, and the second binder easily enters the voids between the hollow fine particles.
[0154]
  And claims8In the invention, since the molecular weight of the second binder is 100 to 5000, it is easy to enter the voids between the hollow fine particles in the low refractive index layer, and the antireflection film can be produced as a dense thin film. It is.
[0155]
  And claims9In the invention, since the second binder contains a curing catalyst, the condensation reaction is promoted to increase the crosslink density in the low refractive index layer, and the water resistance and alkali resistance of the low refractive index layer can be improved. It is.
[0156]
  Claim 10Since the second binder contains a fluorine-containing compound, the surface of the low refractive index layer can be protected from dirt, and even if dirt is attached, the dirt can be easily removed. Is.
[0157]
  Claim 11Since the second binder contains 0.1 to 50% by weight of the fluorine-containing compound, the antifouling property can be further improved.
[0158]
  Claim 12In the invention, since the second binder contains a silicone compound, the surface of the low refractive index layer can be protected from dirt, and even if dirt is attached, the dirt can be easily removed. It is.
[0159]
  Claim 13In the invention, since the second binder contains colloidal silica, the second coating agent composition is likely to enter the voids between the hollow fine particles in the low refractive index layer.
[0160]
  Claim 14In the invention, since the second binder contains fine particles having a refractive index of 1.2 to 1.45 and an average particle size of 0.5 to 100 nm, the voids between the hollow fine particles are easily filled, Thus, the wear resistance can be further improved, and the refractive index of the entire low refractive index layer can be further reduced while maintaining the wear resistance.
[0161]
  Claim 15Since the second binder contains a hollow silica sol, the wear resistance can be further improved and the refractive index of the entire low refractive index layer can be further reduced.
[0162]
  According to a sixteenth aspect of the present invention, there is provided a method for producing an antireflection film comprising substantially spherical fine particles having a single cavity therein, wherein the hollow particles are completely surrounded by a substantially spherical outer shell. After the first binder is applied to the surface of the transparent support and dried to form a low refractive index layer by bonding the hollow fine particles to each other with the first binder, the second binder is applied to the low refractive index layer. By applying, the second binder is filled in the voids between the hollow fine particles in the low refractive index layer, so that the hollow fine particles having cavities therein are highly filled in the low refractive index layer, thereby reducing the low refractive index. By sufficiently filling the gap between the hollow fine particles, the bonding between the hollow fine particles is reinforced to improve the wear resistance. It is what it is.
  Further, n kinds of hollow fine particles having average particle diameters of d1, d2,..., Dn (where d1> d2>...> Dn) are used in combination, and hollow fine particles having an average particle diameter of dk-1 are used. Hollow fine particles having an average particle diameter of dk are dk <0.5 × dk−1 (k =2˜n, 2 ≦ n), the hollow fine particles having the average particle diameter dk are filled in the gaps between the hollow fine particles having the average particle diameter dk−1, and the maximum volume fraction of the plural kinds of hollow fine particles is increased. To do.
[0163]
  Claim 1 of the present invention7The antireflection member according to claim 1 is the first aspect.5Since the antireflection film according to any one of the above is formed on one or both surfaces of the transparent support, it can be used for various applications as an antireflection film.
[0164]
  Claim 18In the invention, since the transparent support is a transparent resin film or a transparent resin plate, it can be used for various applications as an antireflection film.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an antireflection member showing an example of an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing a low refractive index layer before applying a second coating agent composition.
FIG. 3 is a schematic cross-sectional view showing a low refractive index layer (antireflection film) after applying a second coating agent composition.
4 shows the electron micrograph of FIG. 2 (imaging magnification: 100,000 times). FIG.
5 shows the electron micrograph of FIG. 3 (imaging magnification: 100,000 times). FIG.
[Explanation of symbols]
1 cavity
2 Hollow fine particles
3 First binder
4 Low refractive index layer
5 gap
6 Second binder
7 Transparent support

Claims (18)

In a low refractive index layer formed by bonding together hollow particles, each having a substantially spherical fine particle having a single cavity therein, the hollow particle being completely surrounded by a substantially spherical outer shell, with a first binder. The voids between the hollow fine particles are filled with a second binder, and n kinds of hollow fine particles having average particle diameters of d1, d2,..., Dn (d1>d2>...> dn) are mixed. In addition, the hollow fine particles having an average particle diameter of dk-1 and the hollow fine particles having an average particle diameter of dk have a relationship of dk <0.5 × dk−1 (k = 2 to n, 2 ≦ n). Anti-reflective film characterized.   As the hollow fine particles, those having a refractive index of 1.2 to 1.45 and an average particle diameter of 0.5 to 200 nm are used, and the hollow fine particles include 40 to 95% by volume of the entire low refractive index layer including the internal cavities. The antireflection film according to claim 1, wherein the space between the first binder, the second binder, and the hollow fine particles occupies the remaining 60 to 5% by volume.   The voids in the hollow fine particles and the voids between the hollow fine particles occupy 10 to 60% by volume in the low refractive index layer, and the second binder occupies 40% by volume or more of the entire voids between the hollow fine particles. The antireflection film according to claim 1 or 2.   The antireflection film according to any one of claims 1 to 3, wherein one or more kinds of hollow fine particles are used, and at least one of them is a hollow silica sol.   The antireflection film according to any one of claims 1 to 4, wherein the contact angle of the second binder with respect to the low refractive index layer is 0 to 70 °.   6. The antireflection film according to claim 1, wherein the first binder is made of a reactive organosilicon compound.   The antireflection film according to claim 1, wherein the second binder is made of a reactive organosilicon compound.   The antireflective film according to any one of claims 1 to 7, wherein the second binder has a molecular weight of 100 to 5,000.   The antireflection film according to claim 1, wherein the second binder contains a curing catalyst.   The antireflection film according to claim 1, wherein the second binder contains a fluorine-containing compound.   The antireflection film according to claim 10, wherein the second binder contains 0.1 to 50% by weight of a fluorine-containing compound.   The antireflection film according to claim 1, wherein the second binder contains a silicone compound.   The antireflection film according to claim 1, wherein the second binder contains colloidal silica.   The antireflection according to any one of claims 1 to 13, wherein the second binder contains fine particles having a refractive index of 1.2 to 1.45 and an average particle diameter of 0.5 to 100 nm. film.   The antireflection film according to claim 14, wherein the second binder contains a hollow silica sol. A first binder containing hollow spherical fine particles having a single hollow inside, the hollow fine particles being completely surrounded by a substantially spherical outer shell, is applied to the surface of the transparent support and dried. After forming the low refractive index layer by bonding the hollow fine particles to each other with the first binder, the second binder is applied to the low refractive index layer, whereby the voids between the hollow fine particles in the low refractive index layer are formed. The second binder is filled with n hollow fine particles having average particle diameters of d1, d2,..., Dn (where d1>d2>. Antireflection, characterized in that hollow fine particles having a diameter of dk-1 and hollow fine particles having an average particle diameter of dk have a relationship of dk <0.5 × dk−1 (k = 2 to n, 2 ≦ n). A method for producing a membrane.   An antireflection member comprising the antireflection film according to any one of claims 1 to 15 formed on one side or both sides of a transparent support.   The antireflection member according to claim 17, wherein the transparent support is a transparent resin film or a transparent resin plate.

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