JP4712236B2 - Antireflection film, antireflection film, image display device, and manufacturing method thereof - Google Patents

Description

【０１４４】
【表２】

【０１４５】
（実施例２）
本実施例では図４に示す構成の反射防止フィルムＦ１を作成した。反射防止フィルムＦ１は、基材フィルム２４の上にクリアハードコート層２５、中屈折率層２６、高屈折率層２７、低屈折率層２８を順次積層した構成であり、そのうちの高屈折率層と中屈折率層を、本発明に係るコーティング組成物を用いて形成した。
【０１４６】
（１）高屈折率層用コーティング液の調製
ルチル型酸化チタンとして、Ａｌ₂Ｏ₃およびステアリン酸で被覆した、一次粒径約０．０３μｍのルチル型酸化チタンを１００部用意した。電離放射線硬化性バインダー成分として、ペンタエリスリトールトリアクリレート（ＰＥＴ３０、日本化薬社製）を２０部用意した。分散剤としては、エチレンオキサイド鎖を有し且つアニオン性の極性基を有する分散剤（アジスパーＰＡ１１１、味の素（株）製）を２０部用意した。
【０１４７】
これらの材料をメチルイソブチルケトンに混合して、固形分濃度を１５重量％とし、そこに分散メディアとしてジルコニアボールを添加して、ペイントシェーカーにて７時間以上攪拌した。
【０１４８】
得られた分散液に、光開始剤として１−ヒドロキシ−シクロヘキシル−フェニル−ケトン（イルガキュアー １８４）を３部添加した後、メチルイソブチルケトンを添加して固形分濃度を３重量％に希釈し、屈折率１．９０の高屈折率層用コーティング液を得た。
【０１４９】
（２）中屈折率層用コーティング液の調製
ペイントシェーカーで攪拌して得られた上記分散液に、光開始剤として１−ヒドロキシ−シクロヘキシル−フェニル−ケトン（イルガキュアー １８４）を３部添加した。この混合液１００部に対して、ジペンタエリスリトールペンタアクリレート（ＤＰＰＡ）６０部をさらに添加した後、メチルイソブチルケトンを添加して固形分濃度を３重量％に希釈し、屈折率１．７６の中屈折率層用コーティング液を得た。
【０１５０】
（３）塗工、硬化
ＰＥＴ（ポリエチレンテレフタレート）基材上に、ジペンタエリスリトールヘキサアクリレート（ＤＰＨＡ）からなる、屈折率１．５２、乾燥後厚さ３μｍ以上のクリアハードコート層を塗工した。得られたクリアハードコート層の上に、上記中屈折率層用コーティング液（屈折率１．７６）を塗工し、屈折率１．７６、乾燥後厚さ６０ｎｍの中屈折率層を形成し、さらに、その上に上記高屈折率層用コーティング液（屈折率１．９０）を塗工し、屈折率１．９０、乾燥後厚さ８０ｎｍの高屈折率層を形成し、ＵＶ硬化した。その後、高屈折率層上に、シリコン含有フッ化ビニリデン共重合体からなる屈折率１．４２、乾燥後厚さ１００ｎｍの低屈折率層を塗工し、反射防止フィルムを得た。
【０１５１】
（４）評価
実施例２により得られた反射防止フィルムについて、下記方法により反射率、鉛筆硬度、密着性、塗工斑を評価した。反射防止フィルムの層構成と評価結果を、第３表及び第４表にそれぞれ示す。
【０１５２】
実施例２により得られた反射防止フィルムは、４５０〜６５０ｎｍの可視光の反射率が０．４〜０．７％であった。また、この反射防止フィルムは、３Ｈの鉛筆硬度を有していた。
【０１５３】
また、クリアハードコート層上へ中屈折率層用コーティング液を塗工する時に斑を生じると、その上に高屈折率層、さらには低屈折率層という具合に層を重ねるごとに、下層の斑が一層目立つようになったり、各層がそれぞれ斑を生じるなどして、製品にはできない外観となってしまうが、本実施例では、溶剤の変更により、クリアハードコート層上への均一な薄膜塗工性能が向上し、斑の発生を抑えることができた。
【０１５４】
＜評価方法＞
（ａ）反射率
サンプルの裏面に、裏面反射の影響を考慮して黒ビニルテープを貼り、分光光度計により３８０ｎｍ〜７８０ｎｍの反射率を測定した。一点測定の場合には、特に人間が一番眩しいと感じる波長５５０ｎｍの値を示した。
【０１５５】
（ｂ）硬度
ＪＩＳ ５４００に従い鉛筆硬度を測定した。すなわち、サンプルに１ｋｇ荷重をかけた鉛筆により筆記を５本ほど行い、５本中４本が無傷となる最も硬い鉛筆と同じ硬度を有すると評価した。
【０１５６】
（ｃ）密着性
ＪＩＳ ５４００に従いセロハンテープ碁盤目剥離試験を行った。すなわち、塗膜表面にカッターで縦１１本×横１１本の傷を直交させて付け、１ｍｍ幅で１００個の碁盤目状の桝目を設けた。その上からニチバン製セロハンテープを強く密着させた後、５回連続して一気に引き剥がし、膜面に残った桝目の数を数えた。
【０１５７】
（ｄ）塗工斑
サンプルの上、３〜５ｍｍの高さから３輝線蛍光灯で照らし、塗工斑（干渉膜なので、斑、すなわち異なる干渉色が見える。）の有無を観察した。
【０１５８】
（実施例３）
本実施例では図５に示す構成の反射防止フィルムＦ２を作成した。反射防止フィルムＦ２は、基材フィルム２４の上にクリアハードコート層２５、高屈折率層２７、低屈折率層２８を順次積層した構成であり、そのうちの高屈折率層を本発明に係るコーティング組成物を用いて形成した。
【０１５９】
（１）高屈折率層用コーティング液の調製
ルチル型酸化チタンとして、ＺｒＯ₂およびステアリン酸で被覆した、一次粒径約０．０３μｍのルチル型酸化チタンを１００部用意した。電離放射線硬化性バインダー成分として、ペンタエリスリトールトリアクリレート（ＰＥＴ３０、日本化薬社製）を４０部用意した。分散剤としては、エチレンオキサイド鎖を有し且つアニオン性の極性基を有する分散剤を２０部用意した。
【０１６０】
これらの材料をメチルイソブチルケトンに混合して、固形分濃度を１５重量％とし、そこに分散メディアとしてジルコニアボールを添加して、ペイントシェーカーにて７時間以上攪拌した。
【０１６１】
得られた分散液に、光開始剤として１−ヒドロキシ−シクロヘキシル−フェニル−ケトン（イルガキュアー １８４）を３部添加、及び、ペンタエリスリトールペンタアクリレート（ＤＰＰＡ）４０部を添加した後、メチルイソブチルケトンを添加して固形分濃度を２重量％に希釈し、屈折率１．７６の高屈折率層用コーティング液を得た。
【０１６２】
（２）塗工、硬化
ＴＡＣ（トリアセチルセルロース）基材上に、ペンタエリスリトールトリアクリレートからなる、屈折率１．５１、乾燥後厚さ３μｍ以上のクリアハードコート層を塗工し、さらに、その上に上記高屈折率層用コーティング液（屈折率１．７６）を塗工して、屈折率１．７６、乾燥後厚さ９０ｎｍの高屈折率層を形成し、ＵＶ硬化した。その後、高屈折率層上に、シリコン含有フッ化ビニリデン共重合体からなる屈折率１．４２、乾燥後厚さ９０ｎｍの低屈折率層を塗工し、反射防止フィルムを得た。
【０１６３】
（３）評価
実施例３により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例３により得られた反射防止フィルムは、人間が最も眩しさを感じ易い５５０ｎｍ波長での反射率が、０．４％であった。また、この反射防止フィルムは、２Ｈの鉛筆硬度を有していた。
【０１６４】
（実施例４）
本実施例では図６に示す構成の反射防止フィルムＦ３を作成した。反射防止フィルムＦ３は、基材フィルム２４の上にフィラー３０を含有するマットハードコート層２９、高屈折率層２７、低屈折率層２８を順次積層した構成であり、そのうちの高屈折率層を本発明に係るコーティング組成物を用いて形成した。
【０１６５】
（１）高屈折率層用コーティング液の調製
実施例２において屈折率１．７６の中屈折率層用コーティング液を調製するに際して、溶剤をメチルイソブチルケトン（ＭＩＢＫ）から、ＭＩＢＫ９５部とブチルセロソルブ５部の混合溶剤に変更するほかは同様に行って、屈折率１．７６の高屈折率層用コーティング液を得た。
【０１６６】
（２）塗工、硬化
ＴＡＣ基材上に、下記組成を有する屈折率１．５２のマットハードコート層用コーティング液を塗工し、表面タックが残らない程度にＵＶ硬化し、屈折率１．５２、乾燥後厚さ３μｍで、且つ、微細凹凸を有するアンチグレア性のマットハードコート層を形成した。
＜マットハードコート層用コーティング液＞
・ペンタエリスリトールトリアクリレート：２部
・スチレンペースト（ペンタエリスリトールトリアクリレート／ビーズ＝６／４、粒径３．５μｍ）：０．５部
・セルロースアセテートポリプロピオネート（ＣＡＰ）（固形分１０重量％の酢酸エチル溶液）：２．３部
・溶剤（トルエン／シクロヘキサノン＝７／３）：４．４部
・開始剤（イルガキュアー ６５１）：０．０６ｇ
得られたマットハードコート層の微細凹凸表面に、上記高屈折率層用コーティング液（屈折率１．７６）を塗工し、ＵＶ硬化して、屈折率１．７６、乾燥後厚さ６０ｎｍの高屈折率層を形成した。その後、高屈折率層上に、シリコン含有フッ化ビニリデン共重合体からなる屈折率１．４２、乾燥後厚さ９０ｎｍの低屈折率層を塗工し、ＵＶで完全硬化することにより反射防止フィルムを得た。
【０１６７】
（３）評価
実施例４により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例４により得られた反射防止フィルムは、人間が最も眩しさを感じ易い５５０ｎｍ波長での反射率が、０．６％であった。また、この反射防止フィルムは、２Ｈの鉛筆硬度を有していた。
【０１６８】
また、本実施例では、溶剤の変更により、微細凹凸表面を有するマットハードコート層への塗工適正が向上し、高屈折率層用コーティング液を斑を生じることなく塗工できた。
【０１６９】
（実施例５）
本実施例では図７に示す構成の反射防止フィルムＦ４を作成した。反射防止フィルムＦ４は、基材フィルム２４の上に透明導電層３１、フィラー３０を含有する異方導電性マットハードコート層２９、高屈折率層２７、低屈折率層２８を順次積層した構成であり、そのうちの高屈折率層を本発明に係るコーティング組成物を用いて形成した。
【０１７０】
（１）塗工、硬化
実施例４において、ＴＡＣ基材上に透明導電層を設け、マットハードコート層用コーティング液中に導電性材料として金‐ニッケル樹脂ビーズ（ブライトＧＮＲ４．６−ＥＨ、日本化学工業製）を０．００５部添加したほかは、実施例４と同様に行った。
【０１７１】
すなわち、ＴＡＣ基材上にＡＴＯ含有透明導電インキ（住友大阪セメント製、スミセファインＡＳＰ−ＢＪ−ｌ）を塗工し、表面タックが残らない程度にＵＶ硬化し、乾燥膜厚２μｍの透明導電層を形成した。得られた透明導電層の上に、導電材料を添加したマットハードコート層用コーティング液を塗工し、ＵＶ硬化して、屈折率１．５２、乾燥後厚さ３〜４μｍで、且つ、微細凹凸を有するアンチグレア性の異方導電性マットハードコート層を形成した。
【０１７２】
次に、得られたマットハードコート層の上に、高屈折率層用コーティング液（屈折率１．７６）を塗工し、ＵＶ硬化して、屈折率１．７６、乾燥後厚さ６０ｎｍの高屈折率層を形成した。その後、高屈折率層上に、シリコン含有フッ化ビニリデン共重合体からなる屈折率１．４２、乾燥後厚さ９０ｎｍの低屈折率層を形成し、ＵＶで完全硬化することにより反射防止フィルムを得た。
【０１７３】
（２）評価
実施例５により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例５により得られた反射防止フィルムは、人間が最も眩しさを感じ易い５５０ｎｍ波長での反射率が、０．６％であった。また、この反射防止フィルムは、２Ｈの鉛筆硬度を有していた。
【０１７４】
（実施例６）
本実施例では図８に示す構成の反射防止フィルムＦ５を作成した。反射防止フィルムＦ５は、基材フィルム２４の上に高屈折率クリアハードコート層３２、高屈折率層２７、低屈折率層２８を順次積層した構成であり、そのうちの高屈折率クリアハードコート層及び高屈折率層を本発明に係るコーティング組成物を用いて形成した。
【０１７５】
（１）高屈折率層用コーティング液の調製
ルチル型酸化チタンとして、ＺｒＯ₂およびステアリン酸で被覆した、一次粒径約０．０３μｍのルチル型酸化チタンを１００部用意した。電離放射線硬化性バインダー成分として、ペンタエリスリトールトリアクリレート（ＰＥＴ３０、日本化薬社製）を４０部用意した。分散剤としては、エチレンオキサイド鎖を有し且つアニオン性の極性基を有する分散剤を２０部用意した。
【０１７６】
これらの材料をメチルイソブチルケトンに混合して、固形分濃度を１５重量％とし、そこに分散メディアとしてジルコニアボールを添加して、ペイントシェーカーにて７時間以上攪拌した。
【０１７７】
得られた分散液に、光開始剤として１−ヒドロキシ−シクロヘキシル−フェニル−ケトン（イルガキュアー １８４）を３部、及び、ジペンタエリスリトールペンタアクリレート（ＤＰＰＡ）４０部を添加した後、メチルイソブチルケトンを添加して固形分濃度を３重量％に希釈し、屈折率１.８４の高屈折率層用コーティング液を得た。
【０１７８】
（２）高屈折率クリアハードコート層用コーティング液の調製
ペイントシェーカーで攪拌して得られた上記分散液に光開始剤として１−ヒドロキシ−シクロヘキシル−フェニル−ケトン（イルガキュアー １８４）を３部添加した。この混合物１００部に対し、ジペンタエリスリトールペンタアクリレート（ＤＰＰＡ）２０部と、ペンタエリスリトールトリアクリレート５５部を十分に混合して、屈折率１．７０の高屈折率クリアハードコート層用コーティング液を得た。このコーティング液は分散性が良好であるため、バインダー量を増加しても基材フィルムとのヘイズ差は０．０１であった。
【０１７９】
（３）塗工、硬化
ＴＡＣ基材上に、屈折率１．７０の上記高屈折率クリアハードコート層用コーティング液を塗工し、表面タックが残らない程度にＵＶ硬化して、屈折率１．７０、乾燥後厚さ５μｍの高屈折率クリアハードコート層を形成した。それから、高屈折率クリアハードコート層の上に、屈折率１.８４の高屈折率層用コーティング液を塗工し、ＵＶ硬化して、屈折率１.８４、乾燥後厚さ６０ｎｍの高屈折率層を形成した。その後、高屈折率層上に、シリコン含有フッ化ビニリデン共重合体からなる屈折率１．４２、乾燥後厚さ９０ｎｍの低屈折率層を形成し、ＵＶで完全硬化することにより反射防止フィルムを得た。
【０１８０】
（４）評価
実施例６により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例６により得られた反射防止フィルムは、人間が最も眩しさを感じ易い５５０ｎｍ波長での反射率が、０．２％であった。また、この反射防止フィルムは、２Ｈの鉛筆硬度を有していた。
【０１８１】
（実施例７）
本実施例では図９に示す構成の反射防止フィルムＦ６を作成した。反射防止フィルムＦ６は、基材フィルム２４の上にフィラー３０を含有する高屈折率マットハードコート層３３、低屈折率層２８を順次積層した構成であり、そのうちの高屈折率マットハードコート層を本発明に係るコーティング組成物を用いて形成した。
【０１８２】
（１）高屈折率マットハードコート層用コーティング液の調製
実施例６と同様に屈折率１．７０のクリアハードコート層用コーティング液を調製し、得られたコーティング液を使用して下記組成を有する屈折率１．６６の高屈折率マットハードコート層用コーティング液を得た。ルチル型酸化チタン超微粒子の分散性は、マット材（アクリルビーズ）やバインダーを添加しても安定で、基材フィルムとのヘイズ差は、マット材を含有した高屈折率マットハードコート層用コーティング液を塗工し、表面を未処理ＰＥＴでラミネートし、ＵＶ硬化後に剥離することにより凹凸形状のない状態にして測定したところ、０．０１であった。
＜高屈折率マットハードコート層用コーティング液＞
・屈折率１．７０のクリアハードコート層用コーティング液（固形分５０重量％）：４部
・アクリルペースト（ペンタエリスリトールトリアクリレート／ビーズ＝６／４、粒径３．５μｍ）：０．５部
・セルロースアセテートポリプロピオネート（ＣＡＰ）（固形分１０重量％の酢酸エチル溶液）：２．３部
・溶剤（トルエン）：２．４部
・開始剤（イルガキュアー ６５１）：０．０６部
（２）塗工、硬化
ＴＡＣ基材上に、屈折率１．６６の上記高屈折率マットハードコート層用コーティング液を塗工し、表面タックが残らない程度にＵＶ硬化して、微細凹凸表面を有し、屈折率１．６６、乾燥後厚さ３μｍの高屈折率マットハードコート層を形成した。得られた高屈折率マットハードコート層の上に、シリコン含有フッ化ビニリデン共重合体からなる屈折率１．４２、乾燥後厚さ９０ｎｍの低屈折率層を塗工し、ＵＶで完全硬化することにより反射防止フィルムを得た。
【０１８３】
（３）評価
実施例７により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例７により得られた反射防止フィルムは、人間が最も眩しさを感じ易い５５０ｎｍ波長での反射率が、０．８％であった。また、この反射防止フィルムは、２Ｈの鉛筆硬度を有していた。
【０１８４】
（実施例８）
本実施例では図１０に示す構成の反射防止フィルムＦ７を作成した。反射防止フィルムＦ７は、基材フィルム２４の上にフィラー３０を含有する高屈折率マットハードコート層３３、高屈折率層２７、低屈折率層２８を順次積層した構成であり、そのうちの高屈折率マットハードコート層及び高屈折率層を本発明に係るコーティング組成物を用いて形成した。
【０１８５】
（１）塗工、硬化
ＴＡＣ基材上に、実施例７において得た屈折率１．６６の高屈折率マットハードコート層用コーティング液を塗工し、微細凹凸表面を有し、屈折率１．６６、乾燥後厚さ３μｍの高屈折率マットハードコート層を形成した。さらに、その上に、実施例３において得た屈折率１．８４の高屈折率層用コーティング液を塗工し、表面タックが残らない程度にＵＶ硬化して、屈折率１．８４、乾燥後厚さ１８０ｎｍの高屈折率層を形成した。得られた高屈折率層の上に、シリコン含有フッ化ビニリデン共重合体からなる屈折率１．４０、乾燥後厚さ９０ｎｍの低屈折率層を塗工し、ＵＶで完全硬化することにより反射防止フィルムを得た。
【０１８６】
（２）評価
実施例８により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例８により得られた反射防止フィルムは、人間が最も眩しさを感じ易い５５０ｎｍ波長での反射率が、０．５％であった。また、この反射防止フィルムは、２Ｈの鉛筆硬度を有していた。
【０１８７】
（実施例９）
本実施例では図１１に示す構成の反射防止フィルムＦ８を作成した。反射防止フィルムＦ８は、基材フィルム２４の上にフィラー３０を含有する高屈折率マットハードコート層３３、高屈折率層２７、低屈折率層２８、防汚層３４を順次積層した構成であり、そのうちの高屈折率マットハードコート層及び高屈折率層を本発明に係るコーティング組成物を用いて形成した。
【０１８８】
（１）塗工、硬化
ＴＡＣ基材上に、屈折率１．６６の高屈折率マットハードコート層、及び、屈折率１．８４の高屈折率層を形成するまでは前記実施例８と同様に行った。さらに、屈折率１．８４の高屈折率層の上に、屈折率１．４５の低屈折率層用コーティング液としてゾル−ゲルＳｉＯ₂インキをコーティングし、８０℃で１分間乾燥した後、４０℃で１週間エージングを行い、完全に硬化させた。得られた低屈折率層の上に、フッ素系防汚材料をコーティングし、防汚層を形成し、反射防止フィルムを得た。
【０１８９】
（２）評価
実施例９により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例９により得られた反射防止フィルムは、人間が最も眩しさを感じ易い５５０ｎｍ波長での反射率が、１．２％であった。また、この反射防止フィルムは、３Ｈの鉛筆硬度を有していた。
【０１９０】
（実施例１０）
本実施例では図１２に示す構成の反射防止フィルムＦ９を作成した。反射防止フィルムＦ９は、基材フィルム２４の上にクリアハードコート層２５、中屈折率層２６、高屈折率層２７、低屈折率層２８を順次積層した構成であり、そのうちの中屈折率層を本発明に係るコーティング組成物を用いて形成した。
【０１９１】
（１）塗工、硬化
ＰＥＴ基材上に、ジペンタエリスリトールヘキサアクリレート（ＤＰＨＡ）からなる、屈折率１．５２、乾燥後厚さ７μｍ以上のクリアハードコート層を塗工し、さらに、その上に、実施例３において得た高屈折率層用コーティング液（屈折率１．７６）を塗工し、完全にＵＶ硬化して、屈折率１．７６、乾燥後厚さ７０ｎｍの中屈折率層を形成した。得られた中屈折率層上に、スパッタリングによって屈折率１．９０、厚さ８０ｎｍの酸化チタン膜（ＴｉＯｘ）を高屈折率層として形成し、更に、その上に、同じくスパッタリングによって屈折率１．４７、厚さ９０ｎｍの酸化ケイ素膜（ＳｉＯｘ）を低屈折率層として形成した。さらに、その上に、フッ素系防汚材料を塗工し、防汚層を形成し、反射防止フィルムを得た。
【０１９２】
（２）評価
実施例１０により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例１０により得られた反射防止フィルムは、４５０ｎｍ〜６５０ｎｍの可視光領域の反射率が、０．３〜１．２％であった。また、この反射防止フィルムは、３Ｈの鉛筆硬度を有していた。
【０１９３】
（実施例１１）
本実施例では図１３に示す構成の反射防止フィルムＦ１０を作成した。反射防止フィルムＦ１０は、基材フィルム２４の上に透明導電層３１、異方導電性クリアハードコート層２５、中屈折率層２６、高屈折率層２７、低屈折率層２８、防汚層３４を順次積層した構成であり、そのうちの中屈折率層を本発明に係るコーティング組成物を用いて形成した。
【０１９４】
（１）塗工、硬化
ジペンタエリスリトールヘキサアクリレート（ＤＰＨＡ）に、導電性材料として金‐ニッケル樹脂ビーズ（ブライトＧＮＲ４．６−ＥＨ、日本化学工業製）を０．００５部添加してなる、屈折率１．５２のクリアハードコート層用コーティング液を調製した。
【０１９５】
次に、ＰＥＴ基材上に実施例５と同様のＡＴＯ含有透明導電インキ（住友大阪セメント製、スミセファインＡＳＰ−ＢＪ−ｌ）を塗工し、表面タックが残らない程度にＵＶ硬化し、乾燥膜厚２μｍの透明導電層を形成した。得られた透明導電層の上に、上記の導電材料を添加したクリアハードコート層用コーティング液を塗工し、ＵＶ硬化して、屈折率１．５２、乾燥後厚さ７μｍ以上の異方導電性クリアハードコート層を塗工し、さらに、その上に、実施例３において得た高屈折率層用コーティング液（屈折率１．７６）を塗工し、完全にＵＶ硬化して、屈折率１．７６、乾燥後厚さ７０ｎｍの中屈折率層を形成した。得られた中屈折率層上に、スパッタリングによって屈折率１．９０、厚さ８０ｎｍの酸化チタン膜（ＴｉＯｘ）を高屈折率層として形成し、更に、その上に、同じくスパッタリングによって屈折率１．４７、厚さ９０ｎｍの酸化ケイ素膜（ＳｉＯｘ）を低屈折率層として形成した。さらに、その上に、フッ素系防汚材料を塗工し、防汚層を形成し、反射防止フィルムを得た。
【０１９６】
（２）評価
実施例１１により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例１１により得られた反射防止フィルムは、実施例１０のものと同様に、４５０ｎｍ〜６５０ｎｍの可視光領域の反射率が、０．３〜１．２％であった。また、鉛筆硬度も３Ｈだった。
【０１９７】
（実施例１２）
本実施例では図１４に示す構成の反射防止フィルムＦ１１を作成した。反射防止フィルムＦ１１は、基材フィルム２４の上に透明導電層３１、フィラー３０を含有する高屈折率マットハードコート層３３、低屈折率層２８を順次積層した構成であり、そのうちの高屈折率マットハードコート層を本発明に係るコーティング組成物を用いて形成した。
【０１９８】
（１）透明導電層用コーティング液の調製
希釈溶剤を除く下記成分を混合し充分に攪拌した後、さらに希釈溶剤を混合して、透明導電層用コーティング液（固形分約１０重量％）を調製した。
＜透明導電層用コーティング液＞
・ＡＴＯ：２９．４部
・ＯＨ基含有バインダー１（ウレタンアクリレート）：１４．２部
・ＯＨ基含有バインダー２（ペンタエリスリトールトリアクリレート（ＰＥＴＡ）／ヘキサンジオールジアクリレート（ＨＤＤＡ）＝７／３）：２７．８部
・溶剤（メチルセロソルブ）：５５．０部
・開始剤（イルガキュアー １８４）：３部
・希釈溶剤（シクロヘキサノン／トルエン＝３／７）：５８４部
（２）異方導電性高屈折率マットハードコート層用コーティング液の調製
実施例６と同様に屈折率１．７０のクリアハードコート層用コーティング液を調製し、得られたコーティング液を使用して下記組成を有する屈折率１．６６の異方導電性高屈折率マットハードコート層用コーティング液を得た。導電性微粒子としては、平均粒子径５μｍの金‐ニッケル樹脂ビーズ（ブライトＧＮＲ４．６−ＥＨ、日本化学工業製）を用いた。ルチル型酸化チタン超微粒子の分散性は、マット材（アクリルビーズ）やバインダーを添加しても安定で、基材フィルムとのヘイズ差は０．０１であった。
＜異方導電性高屈折率マットハードコート層用コーティング液＞
・屈折率１．７０のクリアハードコート層用コーティング液（固形分５０重量％）：４部
・アクリルペースト（ペンタエリスリトールトリアクリレート／ビーズ＝６／４、粒径３．５μｍ）：０．５部
・セルロースアセテートポリプロピオネート（ＣＡＰ）（固形分１０重量％の酢酸エチル溶液）：２．３部
・開始剤（イルガキュアー ６５１）：０．０６部
・導電性微粒子（ブライトＧＮＲ４．６−ＥＨ、日本化学工業社製）：０．００４５部（全バインダー成分の０．１重量％）
・溶剤（トルエン）：２．４部
（２）塗工、硬化
ＴＡＣ基材上に、前記透明導電層用コーティング液（固形分約１０％）を塗工し、表面タックが残らない程度にＵＶ硬化して、乾燥後厚さ１．２μｍの透明導電層を形成した。この導電層上に、さらに屈折率１．６６の上記異方導電性高屈折率マットハードコート層用コーティング液を塗工、乾燥し、表面タックが残らない程度にＵＶ硬化して、微細凹凸表面を有し、屈折率１．６６、硬化後厚さ３μｍ、表面抵抗２×１０⁷Ω／□の異方導電性高屈折率マットハードコート層を形成した。得られた異方導電性高屈折率マットハードコート層の上に、シリコン含有フッ化ビニリデン共重合体からなる屈折率１．４２、乾燥後厚さ９０ｎｍの低屈折率層を塗工し、ＵＶで完全硬化することにより反射防止フィルムを得た。なお、ＰＥＴ基材を用いた場合も、同様に反射防止フィルムを作成することができた。
【０１９９】
（３）評価
実施例１２により得られた反射防止フィルムについて、実施例２と同様に試験した。層構成と試験結果を第３表、第４表にそれぞれ示す。実施例１２により得られた反射防止フィルムは、人間が最も眩しさを感じ易い５５０ｎｍ波長での反射率が、０．８％であった。また、この反射防止フィルムは、２Ｈの鉛筆硬度を有していた。
【０２００】
（比較例４）
ルチル型酸化チタンとして、Ａｌ₂Ｏ₃およびステアリン酸で被覆した、一次粒径約０．０３μｍのルチル型酸化チタンを１００部用意した。電離放射線硬化性バインダー成分として、ペンタエリスリトールトリアクリレート（ＰＥＴ３０、日本化薬社製）を２０部用意した。分散剤は用いなかった。
【０２０１】
これらの材料をメチルイソブチルケトンに混合して、固形分濃度を１５重量％とし、そこに分散メディアとしてジルコニアボールを添加して、ペイントシェーカーにて７時間以上撹拌した。
【０２０２】
得られた分散液に、光開始剤として１−ヒドロキシ−シクロヘキシル−フェニル−ケトン（イルガキュアー １８４）を３部添加した後、メチルイソブチルケトンを添加して固形分濃度を３重量％に希釈し、屈折率１．９０の高屈折率層用コーティング液を得た。
【０２０３】
得られたコーティング液を塗工したところ、塗膜は白濁していた。また、コーティング液を数時間放置したところ、沈降物が見られた。
【０２０４】
（比較例５）
ルチル型酸化チタンとして、Ａｌ₂Ｏ₃で被覆したが、アニオン性化合物では被覆していない、一次粒径約０．０３μｍのルチル型酸化チタンを１００部用意した。電離放射線硬化性バインダー成分として、ペンタエリスリトールトリアクリレート（ＰＥＴ３０、日本化薬社製）を２０部用意した。分散剤としては、エチレンオキサイド鎖を有し且つアニオン性の極性基を有する分散剤（ホスマーM）を２０部用意した。
【０２０５】
これらの材料をメチルイソブチルケトンに混合して、固形分濃度を１５重量％とし、そこに分散メディアとしてジルコニアボールを添加して、ペイントシェーカーにて７時間以上撹拌した。
【０２０６】
得られた分散液に、光開始剤として１−ヒドロキシ−シクロヘキシル−フェニル−ケトン（イルガキュアー １８４）を３部添加した後、メチルイソブチルケトンを添加して固形分濃度を３重量％に希釈し、コーティング液を得た。
【０２０７】
得られたコーティング液を塗工したところ、塗膜は白濁していた。また、コーティング液を数時間放置したところ、沈降物が見られた。
【０２０８】
（比較例６）
市販のジルコニア（ＺｒＯ₂）分散液（固形分１５重量％、溶剤：トルエン２５．５／アセチルアセトン４２／その他１７．５、住友大阪セメント製）中に、電離放射線硬化性バインダー成分として、ペンタエリスリトールトリアクリレート（ＰＥＴ３０、日本化薬社製）を３部添加し、屈折率１．７６の高屈折率層用コーティング液を調製し、当該高屈折率層用コーティング液を用いて実施例３及び実施例１０と同じ層構成の反射防止フィルムを作成した。
【０２０９】
実施例３と同じ層構成の反射防止フィルムは、鉛筆硬度がＦであり、且つ、クリアハードコート層との密着性はなかった。
【０２１０】
実施例１０と同じ層構成の反射防止フィルムは、鉛筆硬度がＨであり、且つ、クリアハードコート層との密着性はなかった。
【０２１１】
さらに、溶剤系が複雑なため、乾燥時に斑が生じ易かった。また、コーティングに適したケトン系溶剤を用いて固形分１５％の上記ジルコニア（ＺｒＯ₂）分散液を固形分３％に希釈すると、分散剤との相性が悪いためか、分散性が悪化してしまうという問題も生じた。
【０２１２】
【表３】

【０２１３】
【表４】

【０２１４】
【発明の効果】
以上に述べたように、本発明において用いられるコーティング組成物は、高屈折率の酸化チタンの超微粒子を十分に分散させることが可能であり、また分散安定性にも優れているので、分散剤の使用量を少量に抑えることが可能であり、当該コーティング組成物を被塗布面に塗布し電離放射線の照射により硬化させることにより、反射防止膜などの光学部材に必要な高い屈折率と透明性が得られると共に、十分な塗膜強度及び隣接層との密着性を得ることができる。
【０２１５】
また、本発明においては、酸化チタンの光触媒活性を無機化合物による表面処理を行って低下又は消失させて用いるので、バインダー成分の劣化に伴う塗膜の強度低下や、反射防止性能低下の原因となる黄変現象が起こり難い。
【０２１６】
また、上記のコーティング組成物は塗工適性にも優れ、均一な大面積薄膜を容易に形成することができる。
【０２１７】
従って、本発明によれば、透明性、膜強度、隣接層に対する密着性、膜厚の均一性などの諸性能に優れた光透過層を積層してなる高品質の反射防止膜が提供される。また、本発明によれば、そのような高品質の反射防止膜をウエットコーティングにより製造することが可能である。
【０２１８】
特に、上記のコーティング組成物は、酸化チタンの配合量を変えて調節できる屈折率の範囲から考えて、中屈折率層、高屈折率層又は高屈折率ハードコート層を形成するのに適している。
【０２１９】
さらに本発明によれば、コーティング組成物のバインダー成分として、電離放射線硬化性を有すると共に、水素結合形成基を有するバインダー成分を用いることにより、隣接層に対する密着性に優れた硬化層を形成できる。特に、酸化ケイ素蒸着膜や酸化チタンスパッタリング膜のようなドライコーティング法で形成される膜に対しても非常に高い密着性が得られる点で有用である。
【０２２０】
さらに、本発明において用いるコーティング組成物は、塗工適正にも非常に優れており、干渉色斑が非常に見え易いクリアな面を有するハードコート層上でも塗工斑を引き起こさないで、均一な反射防止膜を形成することができ、また、微細凹凸表面を有するマットハードコート層の上にも塗工斑のない膜を形成できる。
【図面の簡単な説明】
【図１】本発明に係る塗膜を含んだ多層型反射防止膜により表示面を被覆した液晶表示装置の一例であり、その断面を模式的に示した図である。
【図２】本発明に係る塗膜を含んだ多層型反射防止膜を設けた配向板の一例であり、その断面を模式的に示した図である。
【図３】本発明に係る塗膜を含んだ反射防止フィルムの一例であり、その断面を模式的に示した図である。
【図４】実施例２において作成した反射防止フィルムの断面を模式的に示した図である。
【図５】実施例３において作成した反射防止フィルムの断面を模式的に示した図である。
【図６】実施例４において作成した反射防止フィルムの断面を模式的に示した図である。
【図７】実施例５において作成した反射防止フィルムの断面を模式的に示した図である。
【図８】実施例６において作成した反射防止フィルムの断面を模式的に示した図である。
【図９】実施例７において作成した反射防止フィルムの断面を模式的に示した図である。
【図１０】実施例８において作成した反射防止フィルムの断面を模式的に示した図である。
【図１１】実施例９において作成した反射防止フィルムの断面を模式的に示した図である。
【図１２】実施例１０において作成した反射防止フィルムの断面を模式的に示した図である。
【図１３】実施例１１において作成した反射防止フィルムの断面を模式的に示した図である。
【図１４】実施例１２において作成した反射防止フィルムの断面を模式的に示した図である。
【符号の説明】
１０１…液晶表示装置
１０２…反射防止フィルム
１…表示面側のガラス基板
２…画素部
３…ブラックマトリックス層
４…カラーフィルター
５、７…透明電極層
６…背面側のガラス基板
８…シール材
９…配向膜
１０…偏光フィルム
１１…バックライトユニット
１２…偏光素子
１３、１４…保護フィルム
１５…接着剤層
１６…ハードコート層
１７…多層型反射防止膜
１８…中屈折率層
１９…高屈折率層
２０…低屈折率層
２１…基材フィルム
２２…高屈折率層
２３…低屈折率層
２４…基材フィルム
２５…クリアハードコート層
２６…中屈折率層
２７…高屈折率層
２８…低屈折率層
２９…マットハードコート層
３０…フィラー
３１…透明導電層
３２…高屈折率クリアハードコート層
３３…高屈折率マットハードコート層
３４…防汚層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating composition excellent in dispersibility, dispersion stability and coating suitability, and a coating film formed using the coating composition. More specifically, a layer constituting an antireflection film covering a display surface such as an LCD or CRT, particularly a high refractive index having both a function as a support layer for a medium to high refractive index layer and a function as a high refractive index layer. The present invention relates to a coating composition suitable for forming a medium to high refractive index layer having good adhesion to adjacent layers such as a refractive index hard coat layer and a vapor deposition layer.
[0002]
The present invention also relates to an antireflection film having a coating layer formed using the coating composition, and an antireflection film and an image display device to which such an antireflection film is applied.
[0003]
[Prior art]
A display surface of an image display device such as a liquid crystal display (LCD) or a cathode ray tube display device (CRT) is required to reflect less light emitted from an external light source such as a fluorescent lamp in order to improve its visibility. .
[0004]
It has been known that the reflectance is reduced by coating the surface of a transparent object with a transparent film having a low refractive index, and an antireflection film using such a phenomenon is provided on the display surface of the image display device. It is possible to improve visibility. The antireflection film is provided with a hard coat layer on a substrate for the purpose of ensuring sufficient hardness, and a low refractive index layer having a lower refractive index than that of the hard coat layer in order to reduce the refractive index of the outermost surface thereon. In order to further improve the antireflection effect, one or more middle to high refractive index layers are provided on the hard coat layer, and the outermost surface is refracted on the middle to high refractive index layer. It has a layer structure in which a low refractive index layer for reducing the refractive index is provided.
[0005]
The high refractive index layer or the middle refractive index layer of such an antireflection film has optical characteristics such as refractive index and transparency that can exhibit a sufficient effect when it is formed into an antireflection film, and other adjacent layers (hard Physical properties such as adhesion to the coating layer and low refractive index layer) and scratch resistance are required.
[0006]
The method for forming the high refractive index layer or the medium refractive index layer of the antireflection film is generally roughly divided into a vapor phase method and a coating method. The vapor phase method includes a physical method such as a vacuum deposition method and a sputtering method, and a CVD method. The coating method includes a roll coating method, a gravure coating method, a slide coating method, a spray method, a dipping method, a screen printing method, and the like.
[0007]
In the case of the vapor phase method, it is possible to form a high-refractive index layer and a medium-refractive index layer of a high-performance and high-quality thin film, but precise atmosphere control in a high vacuum system is necessary. There is a problem that a special heating device or an ion generation acceleration device is required, and the manufacturing device is complicated and large in size, and thus the manufacturing cost is inevitably increased. In addition, it is difficult to increase the area of the thin film of the high refractive index layer and the medium refractive index layer or to form a thin film with a uniform thickness on the surface of a film having a complicated shape.
[0008]
On the other hand, in the case of the spray method among the application methods, there are problems such as poor utilization efficiency of the coating liquid and difficulty in controlling the film forming conditions. In the case of roll coating method, gravure coating method, slide coating method, dipping method, screen printing method, etc., the utilization efficiency of film forming raw material is good, and there are advantages in mass production and equipment cost, but generally The high refractive index layer and the medium refractive index layer obtained by the coating method have a problem that the function and quality are inferior to those obtained by the vapor phase method.
[0009]
In recent years, coating methods in which high refractive index fine particles such as titanium oxide and tin oxide are dispersed in an organic binder solution as a coating method capable of forming thin films of high refractive index layers and medium refractive index layers having excellent quality. There has been proposed a method of applying a working liquid onto a substrate to form a coating film.
[0010]
Since it is essential that the coating film forming the medium to high refractive index layer is transparent in the visible light region, so-called ultrafine particles whose primary particle diameter is not more than the wavelength of visible light are used as the high refractive index fine particles. The high refractive index fine particles need to be uniformly dispersed in the coating liquid and the coating film. However, generally, as the particle diameter of the fine particles is reduced, the surface area of the fine particles increases and the cohesive force between the particles increases. And when the solid component of a coating liquid aggregates, the haze of the coating film obtained will deteriorate. Therefore, the coating liquid for forming the thin film of the high refractive index layer and the medium refractive index layer is required to have sufficient dispersibility to form a uniform coating film having a small haze. The coating liquid is required to have sufficient dispersion stability so that it can be easily stored for a long period of time.
[0011]
The problem of agglomeration of ultrafine particles can be solved by using a dispersant exhibiting good dispersibility with respect to the ultrafine particles. The dispersant adsorbs on the surface of the fine particles while penetrating between the fine particles to be aggregated, and enables uniform dispersion in the solvent while loosening the aggregation state in the course of the dispersion treatment. However, since the surface area of the ultrafine particles is increased, a large amount of a dispersing agent is required to uniformly disperse the ultrafine particles in the coating liquid and to stabilize it to withstand long-term storage. When a large amount of a dispersant is added to the coating liquid, a large amount of the dispersant is also present in the coating film formed using the coating liquid, and the dispersant prevents the binder component from being cured, and the strength of the coating film is reduced. Decrease extremely.
[0012]
Furthermore, the coating solution must be suitable for coating so that a large-area thin film can be easily formed from the viewpoint of mass production, and can be applied uniformly and thinly during coating, and no uneven drying occurs. It is done.
[0013]
Further, the middle to high refractive index layer is required to have sufficient adhesion to the hard coat layer and the low refractive index layer adjacent to the middle to high refractive index layer. When a low refractive index layer such as a silicon oxide (SiOx) film is formed on a medium to high refractive index layer formed from a coating solution by a so-called wet method by a so-called dry coating method such as a vapor deposition method. Is extremely insufficient and easily peels off, and particularly excellent adhesion is required.
[0014]
In addition, the hard coat layer originally has a role as a support layer for the medium to high refractive index layer in order to prevent the antireflection film from being scratched. In the case of a high refractive index hard coat layer that also functions as a medium to high refractive index layer, the number of constituent layers of the antireflection film can be reduced. However, the thickness of the medium to high refractive index layer is about 5 to 200 nm, preferably about 50 to 160 nm, whereas the hard coat layer is 1 to 10 μm for the original purpose of ensuring sufficient hardness. When the high refractive index hard coat layer is formed by the wet method using the same coating liquid as the medium to high refractive index layer coating liquid, it is formed to be considerably thick, preferably about 2 to 5 μm. Further, even when the medium to high refractive index layer is formed by the wet method, the transparency is likely to deteriorate due to aggregation of the high refractive index fine particles. In addition, while the hard coat layer is required to have high hardness, as described above, since the dispersant has a property of preventing the binder from curing the coating film, the dispersant can be blended in the coating liquid for the hard coat layer. The amount is more limited than the medium to high refractive index layer coating solution. Therefore, the demand for reducing the dispersant for the coating liquid for the high refractive index hard coat layer is more severe than for the coating liquid for the medium to high refractive index layer.
[0015]
[Problems to be solved by the invention]
The present invention has been achieved in view of the above-mentioned actual situation, and its first object is to provide a light transmitting layer excellent in various properties such as transparency, film strength, adhesion to adjacent layers, and uniformity of film thickness. The object is to provide a high-quality antireflection film that is laminated.
[0016]
In addition, the second object of the present invention is a high refractive index layer and / or medium refractive index which is excellent in various properties such as transparency, film strength, adhesion to adjacent layers, and uniformity of film thickness and has a sufficiently high refractive index. An object of the present invention is to provide a high-quality antireflection film having an index layer.
[0017]
Further, the third object of the present invention is to provide various performances such as hardness, transparency, adhesion to adjacent layers, and uniformity of film thickness when formed as a base for a medium to high refractive index layer and a low refractive index layer. High quality anti-reflective coating with a high refractive index hard coat layer that can function as a hard coat layer that is excellent and improves the hardness of the reflective film, has a high refractive index, and can also function as a medium to high refractive index layer Is to provide.
[0018]
A fourth object of the present invention is to provide an antireflection film and an image display device provided with an antireflection film capable of achieving the first to third objects.
[0019]
The fifth object of the present invention is to form the light transmission layer constituting the antireflection film, particularly the medium to high refractive index layer and / or the high refractive index hard coat layer by the coating method. An object of the present invention is to provide an antireflection film that can achieve the three objects, and a method for efficiently manufacturing an antireflection film or an image display device including the antireflection film.
[0020]
[Means for Solving the Problems]
  The antireflection film according to the present invention has a single-layer structure composed of one light-transmitting layer having light transmittance or a multilayer structure in which two or more light-transmitting layers having light transmittance and different refractive indexes are laminated. Have
  At least one of the light transmission layers is coated with an inorganic compound that reduces or eliminates the photocatalytic activity and an organic compound and / or an organic metal compound having an anionic polar group, and is in the range of 0.01 to 0.1 μm. Rutile titanium oxide having a particle size, andDispersant having a molecular structure in which a side chain comprising an anionic polar group or a side chain having an anionic polar group is bonded to a main chain having an ethylene oxide chain skeletonIs a cured layer that is uniformly mixed in the cured binder.
[0021]
The antireflection film according to the present invention has the above-described antireflection film on at least one surface side of a light-transmitting base film so that the low refractive index layer of the antireflection film is positioned on the viewing surface side. It is characterized by being laminated.
[0022]
  Further, the image display device according to the present invention has the above antireflection film,The antireflection film is on the viewing sideThe display surface is covered so as to be positioned.
[0023]
  The cured layer of the antireflection film is an essential component,
(1) A rutile type having a primary particle diameter in the range of 0.01 to 0.1 μm, which is coated with an inorganic compound that reduces or eliminates photocatalytic activity and an organic compound and / or organometallic compound having an anionic polar group. Titanium oxide,
(2) ionizing radiation curable binder component,
(3) A dispersant having a molecular structure in which a side chain comprising an anionic polar group or a side chain having an anionic polar group is bonded to a main chain having an ethylene oxide chain skeleton,as well as,
(4) organic solvent,
The coating composition containing can be formed by coating and curing the surface to be coated with the cured layer.
[0024]
The above coating composition can sufficiently disperse ultrafine particles of high refractive index titanium oxide and has excellent dispersion stability, so that the amount of dispersant used can be kept to a small amount. By applying the coating composition to the surface to be coated and curing it by irradiation with ionizing radiation, the high refractive index and transparency required for an optical member such as an antireflection film can be obtained, and sufficient coating strength And adhesion with an adjacent layer can be obtained.
[0025]
Further, in the present invention, the photocatalytic activity of titanium oxide is reduced or eliminated by performing a surface treatment with an inorganic compound, which causes a decrease in the strength of the coating film due to deterioration of the binder component and a decrease in antireflection performance. Yellowing phenomenon is unlikely to occur.
[0026]
In addition, the coating composition is also excellent in coating suitability and can easily form a uniform large-area thin film.
[0027]
Therefore, according to the present invention, there is provided a high-quality antireflection film formed by laminating a light transmission layer excellent in various properties such as transparency, film strength, adhesion to adjacent layers, and film thickness uniformity. . Further, according to the present invention, it is possible to produce such a high quality antireflection film by a coating method.
[0028]
In particular, the coating composition described above is suitable for forming a medium refractive index layer, a high refractive index layer, or a high refractive index hard coat layer in view of a refractive index range that can be adjusted by changing the blending amount of titanium oxide. Yes.
[0029]
When forming a high refractive index layer and / or a medium refractive index layer using the coating composition, the film thickness is 0.05 to 0.2 μm, the refractive index is 1.55 to 2.30, and The haze value specified in JIS-K7361-1 is not different from the haze value of the base material alone, or the difference between the haze value of the base material alone is 1% or less is formed. be able to.
[0030]
When a high refractive index hard coat layer is formed using the coating composition, the film thickness is 1 to 10 μm, preferably 2 to 5 μm, the refractive index is 1.55 to 1.83, and Forming a high refractive index hard coat layer in which the haze value defined in JIS-K7361-1 is not different from the haze value of the base material alone or the difference from the haze value of the base material is within 3%. Can do.
[0031]
Therefore, according to the present invention, a high refractive index layer and / or a medium refractive index layer having excellent performance such as transparency, film strength, adhesion to an adjacent layer, and uniformity of film thickness and a sufficiently high refractive index. A high-quality antireflection film is provided.
[0032]
In addition, according to the present invention, when formed as an underlayer for a medium to high refractive index layer and a low refractive index layer, it is excellent in various properties such as hardness, transparency, adhesion to an adjacent layer, and uniformity of film thickness, and reflection. There is also provided a high-quality antireflection film having a high refractive index hard coat layer that can function as a hard coat layer that improves the hardness of the film, has a high refractive index, and can also function as a medium to high refractive index layer. The
[0033]
In this case, the surface of the high-refractive-index hard coat layer may be formed into a fine concavo-convex shape to form a hard coat layer that functions as an antiglare layer (antiglare layer).
[0034]
Examples of the inorganic compound covering titanium oxide include alumina, silica, zinc oxide, zirconium oxide, tin oxide, tin oxide doped with antimony (ATO), tin-doped indium oxide (ITO), and zinc-doped indium oxide. A compound selected from the group consisting of (IZO), zinc oxide doped with aluminum (AZO), and tin oxide doped with fluorine (FTO) is preferably used.
[0035]
  An organic carboxylic acid is preferably used as the organic compound that coats titanium oxide. Moreover, as said organometallic compound which coat | covers a titanium oxide, a silane coupling agent and / or a titanate coupling agent are used suitably.
[0036]
As the ionizing radiation curable binder component, a binder component having an anionic polar group is preferably used. The binder component having an anionic polar group has a high affinity with titanium oxide and acts as a dispersion aid, thereby improving the dispersibility of titanium oxide in the coating composition and in the coating film. Since there is an effect which reduces the usage-amount of an agent, it is preferable. Since the dispersant does not function as a binder, the coating strength can be improved by reducing the blending ratio of the dispersant.
[0037]
As the binder component, it is preferable to use one having a hydroxyl group in the molecule. Since the hydroxyl group is an anionic polar group and has a large affinity for titanium oxide, the binder component having a hydroxyl group acts as a dispersion aid, and the amount of the dispersant added can be reduced.
[0038]
The binder component is particularly preferably one having a hydrogen bond forming group as an anionic polar group. In the case where the binder component has a hydrogen bond forming group, in addition to improving the dispersibility of titanium oxide by the effect as an anionic polar group, the hard coat layer, the middle refractive index layer, the high refractive index layer by hydrogen bonding It is possible to improve the adhesion between adjacent layers such as a low refractive index layer and a transparent conductive layer.
[0039]
When the medium to high refractive index layer or the high refractive index hard coat layer according to the present invention contains a hydrogen bond-forming group, and a layer adjacent to these also contains a hydrogen bond-forming group, particularly excellent adhesion is obtained. can get.
[0040]
As an adjacent layer containing a hydrogen bond forming group, a titanium oxide (TiOx) film as a middle to high refractive index layer may be formed by sputtering which is a dry coating method. As the low refractive index layer, a silicon oxide (SiOx) film may be formed by a vapor deposition method that is a dry coating method or a sol-gel reaction that is a wet method. In some cases, the transparent conductive layer is formed by a wet method using a coating composition containing a binder component having a hydrogen bond-forming group and a conductive material such as ATO or ITO. Further, an ATO vapor deposition film or an ITO vapor deposition film as a transparent conductive layer may be formed by a dry coating method.
[0041]
Conventionally, when a titanium oxide film or a silicon oxide film is formed on a middle to high refractive index layer formed by a wet method by a dry coating method, sufficient adhesion cannot be obtained and the film is easily peeled off. . On the other hand, according to the present invention, a medium to high refractive index layer or a high refractive index hard coat layer is formed by a wet method using a coating composition containing a binder component having a hydrogen bond-forming group. It is very useful because it can be formed on the high refractive index layer with good adhesion by a dry coating method.
[0048]
DETAILED DESCRIPTION OF THE INVENTION
First, the coating composition used in the present invention will be described. In the present invention, in order to form various light transmission layers constituting the antireflection film,
(1) A rutile type having a primary particle diameter in the range of 0.01 to 0.1 μm, which is coated with an inorganic compound that reduces or eliminates photocatalytic activity and an organic compound and / or organometallic compound having an anionic polar group. Titanium oxide,
(2) ionizing radiation curable binder component,
(3) a dispersant having an anionic polar group, and
(4) organic solvent,
A coating composition containing is used. The coating composition may contain other components as required.
[0049]
Various light-transmitting layers constituting an antireflection film by a coating method using the coating composition, and in particular, a light-transmitting layer requiring a high refractive index such as a medium to high refractive index layer or a high refractive index hard coat layer Can be formed efficiently.
[0050]
Among the essential components, titanium oxide is a main component for adjusting the refractive index of a coating film formed using the coating composition to a desired value. Titanium oxide is suitable as a component for adjusting the refractive index because it has a high refractive index and is colorless or hardly colored. Titanium oxide includes rutile type, anatase type, and amorphous type. In the present invention, rutile type titanium oxide having a higher refractive index than anatase type and amorphous type is used.
[0051]
Titanium oxide has a so-called ultrafine particle size so as not to lower the transparency of the coating film. Here, “ultrafine particles” are generally submicron-order particles, and have a particle size larger than particles having a particle diameter of several μm to several hundred μm, which are generally called “fine particles”. It means a small thing. That is, in the present invention, titanium oxide having a primary particle diameter of 0.01 μm or more and 0.1 μm or less, preferably 0.03 μm or less is used. Those having an average particle diameter of less than 0.01 μm are difficult to uniformly disperse in the coating composition, and as a result, a coating film in which the titanium oxide ultrafine particles are uniformly dispersed cannot be obtained. Moreover, the thing with an average particle diameter exceeding 0.1 micrometer is unpreferable since the transparency of a coating film is impaired. The primary particle diameter of titanium oxide may be visually measured with a scanning electron microscope (SEM) or the like, or mechanically measured with a particle size distribution meter using a dynamic light scattering method or a static light scattering method. Good.
[0052]
If the primary particle diameter of the titanium oxide ultrafine particles is within the above range, the particle shape can be used in the present invention regardless of whether it is spherical, needle-shaped, or any other shape.
[0053]
Since titanium oxide has photocatalytic activity, when a coating film is formed using a coating liquid containing titanium oxide that has not been subjected to any surface treatment, the binder is formed between the binders that are forming the coating film by photocatalytic action. The chemical bond is broken and the strength of the coating film is reduced, or the coating film is yellowed and the transparency and haze of the coating film are likely to deteriorate. Therefore, the surface of titanium oxide is used by being coated with an inorganic compound that reduces or eliminates the photocatalytic activity. Examples of such inorganic compounds include alumina, silica, zinc oxide, zirconium oxide, tin oxide, antimony-doped tin oxide (ATO), tin-doped indium oxide (ITO), and zinc-doped indium oxide ( IZO), zinc oxide doped with aluminum (AZO), tin oxide doped with fluorine (FTO), etc. can be exemplified, and these can be used alone or in combination of two or more. it can.
[0054]
In order to coat the surface of titanium oxide fine particles with an inorganic compound, a salt of the inorganic compound to be coated or an organic compound capable of forming an inorganic compound to be coated by hydrolysis in a dispersion in which titanium oxide fine particles are dispersed in water. A desired inorganic compound is physicochemically adsorbed on the surface of the titanium oxide fine particles by adding a metal compound and changing the pH and / or temperature conditions.
[0055]
Titanium oxide coated with an inorganic compound is also present in commercial products. For example, titanium oxide coated with alumina can be obtained from Ishihara Sangyo under the trade name TTO51 (A).
[0056]
The surface of titanium oxide is coated with an inorganic compound in order to reduce or eliminate the photocatalytic activity, and is coated with an organic compound or an organometallic compound in order to increase dispersibility in an organic solvent. In order to disperse the titanium oxide, the coating composition according to the present invention is blended with a dispersant having an anionic polar group as will be described later. The surface of the titanium oxide is treated with an organic compound or an organometallic compound to make it hydrophobic. By imparting properties, the dispersibility of titanium oxide in the coating liquid can be further improved. Since an anionic polar group has a large affinity with titanium oxide, in the present invention, the titanium oxide is coated with an organic compound having an anionic polar group and / or an organometallic compound having an anionic polar group.
[0057]
As the organic compound having an anionic polar group, those having an anionic polar group such as a carboxyl group, a phosphate group, or a hydroxyl group can be used. For example, stearic acid, lauric acid, oleic acid, Examples thereof include linoleic acid, linolenic acid, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, EO (ethylene oxide) -modified phosphoric acid triacrylate, ECH-modified glycerol triacrylate, and the like.
[0058]
Moreover, as an organometallic compound having an anionic polar group, a silane coupling agent and / or a titanate coupling agent can be used.
[0059]
Specific examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-amino. Propyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldiethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris ( Examples thereof include 2-methoxyethoxy) silane and 3-methacryloxypropyltrimethoxysilane.
[0060]
Specific examples of titanate coupling agents are those commercially available from Ajinomoto Co., Inc., such as Preneact KR-TTS, KR-46B, KR-55, KR-41B, KR-38S, KR-138S, and KR. -238S, 338X, KR-44, KR-9SA, KR-ET, etc., and tetramethoxy titanium, tetraethoxy titanium, tetraisopropoxy titanium, tetra n-propoxy titanium, tetra n-butoxy titanium, tetra sec Metal alkoxides such as -butoxy titanium and tetra tert-butoxy titanium can also be used.
[0061]
As the organic compound and / or organometallic compound for surface treatment of titanium oxide, it is particularly preferable to use a coupling agent and an organic carboxylic acid. Moreover, when preparing a coating composition using the ketone solvent mentioned later, 1 type is used independently or 2 from a coupling agent and stearic acid, lauric acid, oleic acid, linoleic acid, and linolenic acid. It is preferable to use a combination of species or more, and sufficient dispersibility can be obtained.
[0062]
To coat the surface of titanium oxide with an organic compound and / or an organometallic compound to impart hydrophobicity, the organic compound and / or organometallic compound having an anionic polar group is dissolved in an organic solvent, The solution can be coated by completely evaporating and removing the organic solvent after the surface treatment of the inorganic compound has not yet been carried out in this solution or after the already applied titanium oxide is dispersed.
[0063]
Titanium oxide coated with both inorganic and organic compounds is also present in commercial products. For example, titanium oxide coated with alumina and stearic acid is traded under the trade name TTO51 (C). Can be obtained from
[0064]
The ionizing radiation curable binder component is blended as an essential component in order to impart film forming properties and adhesion to the substrate and adjacent layers to the coating composition. Since the ionizing radiation curable binder component is present in a monomer or oligomer state that is not polymerized in the coating composition, it is excellent in coating suitability of the coating composition and can easily form a uniform large-area thin film. Moreover, sufficient coating-film intensity | strength is obtained by polymerizing and hardening the binder component in a coating film after coating.
[0065]
As the ionizing radiation curable binder component, it is possible to use a monomer or oligomer having a functional group that causes a polymerization reaction directly by irradiation of ionizing radiation such as ultraviolet rays or electron beams or indirectly by the action of an initiator. it can. In the present invention, radically polymerizable monomers and oligomers having an ethylenic double bond can be mainly used, and a photoinitiator is combined as necessary. However, other ionizing radiation curable binder components may be used. For example, a photocationically polymerizable monomer or oligomer such as an epoxy group-containing compound may be used. If necessary, a photocationic initiator is used in combination with the photocationically polymerizable binder component. The monomer or oligomer as the binder component is preferably a polyfunctional binder component having two or more polymerizable functional groups so that cross-linking occurs between the molecules of the binder component.
[0066]
Specific examples of radically polymerizable monomers and oligomers having an ethylenic double bond include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl acrylate, and 2-hydroxy-3-phenoxy. Monofunctional (meth) acrylates such as propyl acrylate, carboxypolycaprolactone acrylate, acrylic acid, methacrylic acid, acrylamide; diacrylates such as pentaerythritol triacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate monostearate; trimethylolpropane tri Tri (meth) acrylates such as acrylate and pentaerythritol triacrylate, pentaerythritol tetraacrylate derivatives and dipen Polyfunctional (meth) acrylates such as pentaerythritol pentaacrylate, or can be exemplified those radically polymerizable monomers are polymerized oligomer. Here, “(meth) acrylate” means acrylate and / or methacrylate.
[0067]
Among the ionizing radiation curable binder components, the binder component having an anionic polar group has high affinity with titanium oxide and acts as a dispersion aid. Therefore, the dispersibility of titanium oxide in the coating composition and the coating film is improved, and there is an effect of reducing the amount of the dispersant used, which is preferable.
[0068]
The binder component is particularly preferably one having a hydrogen bond forming group as an anionic polar group. In the case where the binder component has a hydrogen bond forming group, in addition to improving the dispersibility of titanium oxide by the effect as an anionic polar group, a hard coat layer, a medium refractive index layer, a high refractive index layer, a low refractive index It becomes possible to improve the adhesiveness with respect to adjacent layers, such as a rate layer and a transparent conductive layer. When the binder component of the light transmission layer containing the titanium oxide ultrafine particles has a hydrogen bond-forming group and the adjacent layer such as the hard coat layer also contains a hydrogen bond-forming group, the hydrogen bond causes adhesion between the two. This is particularly preferable because the properties are further improved.
[0069]
For example, when a medium to high refractive index layer is formed using a coating composition containing a binder component having a hydrogen bond-forming group, a so-called wet method (coating liquid is applied to the film forming surface and dried and / or Hard coating layers, high refractive index layers, and low refractive index layers formed from coating liquids by the curing method) and so-called dry coating methods such as vapor deposition and sputtering (gas phase state on the film forming surface) Excellent adhesion to a high refractive index layer and a low refractive index layer formed by the method of adhering and precipitating the material.
[0070]
As the middle to high refractive index layer, a titanium oxide (TiOx) film may be formed by sputtering which is a dry coating method. Titanium oxide has an oxygen atom in the molecule and can form a hydrogen bond. As the low refractive index layer, a silicon oxide (SiOx) film may be formed by a vapor deposition method that is a dry coating method or a sol-gel reaction that is a wet method. The silicon oxide film contains silanol groups and can form hydrogen bonds. A high refractive index hard coat layer using a binder component having a hydrogen bond-forming group exhibits particularly excellent adhesion to a film containing such a hydrogen bond-forming group.
[0071]
Conventionally, when a titanium oxide film or a silicon oxide film is formed on a middle to high refractive index layer formed by a wet method by a dry coating method, sufficient adhesion cannot be obtained and the film is easily peeled off. On the other hand, when a medium to high refractive index layer is formed using a coating composition containing a binder component having a hydrogen bond-forming group, it adheres to the medium to high refractive index layer by a dry coating method. Since it can form into a film with good property, it is very useful.
[0072]
Further, for the purpose of antistatic, a transparent conductive layer containing a transparent conductive material such as ITO or ATO is provided in the antireflection film by a wet method or a dry coating method, and has anisotropic conductivity on the transparent conductive layer. That is, a hard coat layer having a volume resistivity in the film surface direction higher than a volume conductivity in the film thickness direction may be formed. In such a case, a high refractive index hard coat layer having good adhesion to the transparent conductive layer can be obtained by applying a coating composition containing a binder component having a hydrogen bond-forming group on the transparent conductive layer. Can be formed and is very useful.
[0073]
When the transparent conductive layer is formed by a wet method, a large amount of hydrogen bond forming groups can be contained in the transparent conductive layer by forming the transparent conductive layer using a binder component having a hydrogen bond forming group. Particularly excellent adhesion can be obtained between the high refractive index hard coat layer containing a hydrogen bond-forming group. Examples of the binder component that forms the transparent conductive layer include urethane acrylate resins having a hydroxyl group as a hydrogen bond forming group. When the transparent conductive layer is formed by a dry coating method, a metal oxide vapor deposition film such as an ITO vapor deposition film or an ATO vapor deposition film is obtained, and the film composition is mostly occupied by a metal oxide having oxygen atoms. Therefore, hydrogen bonds can be easily formed, and sufficient adhesion can be obtained with the high refractive index hard coat layer containing hydrogen bond forming groups. In order to form a high refractive index hard coat layer having anisotropic conductivity, the anisotropic conductive property together with a binder component having a hydrogen bond forming group is added to the coating composition for high refractive index hard coat layer according to the present invention. What is necessary is just to mix | blend the electroconductive fine particle for providing and apply | coat on a transparent conductive layer. Examples of conductive fine particles for imparting anisotropic conductivity include organic beads surface-treated with gold and / or nickel.
[0074]
As the binder component having a hydrogen bond-forming group, specifically, a binder component having a hydroxyl group in the molecule can be used. As the binder component having a hydroxyl group in the molecule, a binder component which is pentaerythritol polyfunctional (meth) acrylate or dipentaerythritol polyfunctional (meth) acrylate and which leaves a hydroxyl group in the molecule can be used. That is, in such a binder component, two or more molecules of (meth) acrylic acid are ester-bonded to one molecule of pentaerythritol or dipentaerythritol. Some remain unesterified, and examples thereof include pentaerythritol triacrylate. Since pentaerythritol polyfunctional acrylate and dipentaerythritol polyfunctional acrylate have two or more ethylenic double bonds in one molecule, a crosslinking reaction occurs during polymerization, and high coating strength can be obtained.
[0075]
Photoinitiators that initiate radical polymerization include, for example, acetophenones, benzophenones, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, thiuram compounds And fluoroamine compounds are used. More specifically, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, benzyldimethylketone, 1- (4-dodecyl) Phenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane Examples thereof include -1-one and benzophenone. Among these, 1-hydroxy-cyclohexyl-phenyl-ketone and 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one are polymerized by irradiation with ionizing radiation even in a small amount. Since it initiates and accelerates the reaction, it is preferably used in the present invention. These can be used either alone or in combination. These also exist in commercial products, for example, 1-hydroxy-cyclohexyl-phenyl-ketone is available from Nippon Ciba-Geigy under the trade name Irgacure 184.
[0076]
The dispersant having an anionic polar group has an anionic polar group having high affinity for titanium oxide, and is added to impart dispersibility to titanium oxide to the coating composition according to the present invention. Is done. Examples of the anionic polar group include a carboxyl group, a phosphate group, and a hydroxyl group.
[0077]
As the dispersant having an anionic polar group, specifically, a product group supplied by Big Chemie Japan under the trade name of Disperbyk, that is, Disperbyk-111, Disperbyk-110, Disperbyk-116, Disperbyk-140 , Disperbyk-161, Disperbyk-162, Disperbyk-163, Disperbyk-164, Disperbyk-170, Disperbyk-171, Disperbyk-174, Disperbyk-180, Disperbyk-182 and the like.
[0078]
Among these, the main chain having an ethylene oxide chain skeleton has a molecular structure in which a side chain composed of an anionic polar group as described above or a side chain having an anionic polar group is bonded, and has a number average molecular weight. When a compound having a molecular weight of 2,000 to 20,000 is used, particularly good dispersibility is obtained. The number average molecular weight can be measured by a GPC (gel permeation chromatography) method. In order to meet such a condition, there is Disperbyk 163 in the above Dispersic series.
[0079]
When a high refractive index hard coat layer is formed using the above coating composition, the surface of the high refractive index hard coat layer is made fine by blending and applying a mat material such as organic fine particles to the coating composition. The function as an anti-glare layer can be imparted by forming irregularities. Here, as the mat material for forming the fine irregularities, specifically, styrene beads or acrylic beads having an average particle diameter of about 1 to 10 μm by SEM observation can be used.
[0080]
In addition, a metal plate having a preferable surface shape or a PET film having a matte surface is pressed on the coating film of the coating composition, embossed, and photocured in that state, and then the plate and the PET film are removed. Also, fine irregularities can be formed on the surface of the high refractive index hard coat layer.
[0081]
The organic solvent for dissolving and dispersing the solid component of the coating composition is not particularly limited, and various solvents such as alcohols such as isopropyl alcohol, methanol and ethanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons; aromatic hydrocarbons such as toluene and xylene; or a mixture thereof can be used.
[0082]
In the present invention, it is preferable to use a ketone-based organic solvent. When the coating composition according to the present invention is prepared using a ketone solvent, it can be easily and uniformly applied to the surface of the substrate, and the evaporation rate of the solvent is moderate after coating and hardly causes uneven drying. Therefore, a large-area coating film having a uniform thickness can be easily obtained.
[0083]
As a ketone solvent, it contains a single solvent composed of one kind of ketone, a mixed solvent composed of two or more kinds of ketones, and other solvents together with one or more kinds of ketones, and has lost its properties as a ketone solvent. Those that are not can be used. Preferably, a ketone solvent in which 70% by weight or more, particularly 80% by weight or more of the solvent is occupied by one or two or more ketones is used.
[0084]
By using a ketone solvent as an organic solvent and coating the surface of titanium oxide with an organic compound and / or an organometallic compound as described above, a coating composition excellent in coating suitability is obtained, and a uniform large area is obtained. A thin film can be formed easily. Even in this case, an ethylene oxide-based dispersant as described above as a dispersant having an anionic polar group, that is, a side chain composed of an anionic polar group in the main chain having a skeleton of an ethylene oxide chain or an anionic It is more preferable to use a compound having a molecular structure in which side chains having polar groups are bonded and having a number average molecular weight of 2,000 to 20,000. Alternatively, as the binder component, it is also effective to use a pentaerythritol polyfunctional (meth) acrylate or dipentaerythritol polyfunctional (meth) acrylate, which has a hydroxyl group in the molecule.
[0085]
The coating composition according to the present invention contains, as essential components, titanium oxide, an ionizing radiation curable binder component, a dispersant having an anionic polar group, and an organic solvent, and if necessary, ionizing radiation curable. The binder component polymerization initiator is included, but other components may be further blended. For example, an ultraviolet shielding agent, an ultraviolet absorber, a surface conditioner (leveling agent), zirconium oxide, tin oxide doped with antimony, or the like can be used as necessary.
[0086]
The blending ratio of each component can be adjusted as appropriate, but generally, 4 to 20 parts by weight of the binder component and 4 dispersants having an anionic polar group with respect to 10 parts by weight of titanium oxide. It mix | blends in the ratio of 10 weight part. However, when using a binder component having an anionic polar group in the molecule, the binder component acts as a dispersion aid, so the amount of the dispersant having an anionic polar group is greatly reduced. be able to. Since the dispersant does not function as a binder, the coating strength can be improved by reducing the blending ratio of the dispersant.
[0087]
Specifically, 4 to 20 parts by weight of a binder component having an anionic polar group and 2 to 4 parts by weight of a dispersant having an anionic polar group with respect to 10 parts by weight of titanium oxide. Can be blended. This blending ratio is particularly suitable as a coating composition for a medium to high refractive index layer.
[0088]
Further, the coating composition containing 70 to 320 parts by weight of the binder component having an anionic polar group in the molecule and 2 to 4 parts by weight of a dispersant with respect to 10 parts by weight of titanium oxide It is particularly suitable for forming a high refractive index hard coat layer. Furthermore, you may mix | blend the mat material particle for providing the function as an anti-glare layer (anti-glare layer) in the ratio of 1-50 weight part to this coating composition for high refractive index hard-coat layers.
[0089]
When using a photoinitiator, a photoinitiator is normally mix | blended in the ratio of 3-8 weight part with respect to 100 weight part of binder components.
[0090]
The amount of the organic solvent is appropriately adjusted so that each component can be uniformly dissolved and dispersed, does not cause aggregation during storage after preparation, and does not become too dilute during coating. Prepare a high-concentration coating composition by reducing the amount of solvent used within the range where this condition is satisfied, store it in a state that does not take up the volume, take out the necessary amount at the time of use, and make the concentration suitable for coating work It is preferred to dilute. In the present invention, when the total amount of the solid content and the organic solvent is 100 parts by weight, the organic solvent is used in an amount of 50 to 95. 5 parts by weight, more preferably, by using 70 to 90 parts by weight of an organic solvent with respect to 10 to 30 parts by weight of the total solid content, the coating composition is particularly excellent in dispersion stability and suitable for long term storage Is obtained.
[0091]
In order to prepare the coating composition according to the present invention using each of the above components, it may be dispersed according to a general method for preparing a coating solution. For example, each essential component and each desired component are mixed in an arbitrary order, a medium such as beads is added to the obtained mixture, and a dispersion composition is appropriately dispersed with a paint shaker or a bead mill to obtain a coating composition. .
[0092]
The coating composition thus obtained comprises, as essential components, rutile-type titanium oxide particles having a predetermined primary particle size and coated with an inorganic compound and an organic compound and / or an organometallic compound, and an ionizing radiation curable binder. A component and a dispersant having an anionic polar group are dissolved and dispersed in an organic solvent. In particular, the titanium oxide particles are an organic compound and / or an organometallic compound covering the titanium particles. And a dispersant having an anionic polar group are uniformly dispersed in the coating composition.
[0093]
The coating composition according to the present invention has excellent dispersibility and dispersion stability of titanium oxide by blending a dispersant having an anionic polar group and coating with an organic compound and / or an organometallic compound having an anionic polar group. The haze is very small. That is, by adjusting the refractive index by controlling the amount of titanium oxide in the coating composition according to the present invention, applying the coating composition to the surface of a substrate such as a substrate, drying and curing A coating film having a predetermined refractive index, high transparency, and low haze can be obtained. Therefore, the coating composition according to the present invention is suitable for forming one or more layers constituting the antireflection film, and is particularly considered from the range of the refractive index that can be adjusted by changing the amount of titanium oxide. Therefore, it is suitable for forming a medium refractive index layer, a high refractive index layer, or a high refractive index hard coat layer.
[0094]
In addition, the coating composition according to the present invention is excellent in dispersion stability over a long period of time, so that the pot life is long, and even when used after storage for a long period of time, a coating film having high transparency and low haze is formed. can do.
[0095]
Furthermore, the coating composition according to the present invention is excellent in coating suitability, and can be easily and thinly and uniformly applied to the surface of the object to be coated, thereby forming a uniform large-area thin film. In particular, when a ketone solvent is used, a uniform solvent film having a moderate viscosity and a slower evaporation rate is less likely to cause uneven drying of the coating film, so that it is particularly easy to form a uniform large-area thin film.
[0096]
By applying the antireflection film coating composition of the present invention to the surface of an object to be coated such as a substrate, drying and ionizing radiation curing, it is possible to form a substantially colorless and transparent coating film having a small haze. it can.
[0097]
The support on which the coating composition of the present invention is applied is not particularly limited. As a preferable support, for example, a glass plate; triacetate cellulose (TAC), polyethylene terephthalate (PET), diacetyl cellulose, acetate butyrate cellulose, polyethersulfone, acrylic resin; polyurethane resin; polyester; polycarbonate; Examples thereof include films formed of various resins such as polyether; trimethylpentene; polyether ketone; (meth) acrylonitrile. The thickness of a base material is about 25 micrometers-about 1000 micrometers normally, Preferably it is 50 micrometers-190 micrometers.
[0098]
The coating composition is based on various methods such as spin coating method, dip method, spray method, slide coating method, bar coating method, roll coater method, meniscus coater method, flexographic printing method, screen printing method, and bead coater method. It can be applied on the material.
[0099]
After applying the coating composition according to the present invention to the surface of a substrate such as a substrate in a desired coating amount, it is usually heated and dried by a heating means such as an oven, and thereafter, ultraviolet rays, electron beams, etc. A coating film is formed by curing by emitting ionizing radiation.
[0100]
The coating film thus obtained is coated with an inorganic compound that reduces or eliminates the photocatalytic activity and an organic compound and / or an organic metal compound having an anionic polar group, and is in the range of 0.01 to 0.1 μm. A rutile type titanium oxide having a particle size and a dispersant having an anionic polar group are uniformly mixed in a cured binder, but contain other components as necessary. May be.
[0101]
The coating film (cured layer) obtained by the present invention can be suitably used as one or more layers constituting the antireflection film, and in particular, a refractive index range that can be adjusted by changing the amount of titanium oxide. Therefore, it is suitable for forming a medium to high refractive index layer. According to the present invention, when a coating film having a post-curing film thickness of 0.05 to 0.2 μm is formed, the refractive index is 1.55 to 2.30, and the substrate is in accordance with the provisions of JIS-K7361-1. It is possible to suppress the haze value measured in an integrated state with the haze value of the base material alone or the difference between the haze value of the base material alone and within 1%.
[0102]
The coating film obtained by the present invention is also suitable for forming a high refractive index hard coat layer. According to the present invention, when a coating film having a film thickness of 1 to 10 μm after curing is formed, the haze value specified by JIS-K7361-1 is the refractive index of 1.55 to 1.83 and It is possible to suppress the difference between the haze value of only the material or the haze value of only the base material to be within 3%, and a high refractive index hard coat layer can also be formed.
[0103]
The coating film according to the present invention can be suitably used to form an antireflection film. In principle, the antireflection film may include at least a high refractive index layer and a low refractive index layer, and may further include one or more medium refractive index layers. The layers and the low-refractive index layer are laminated so that the refractive index levels are alternately switched and the low-refractive index layer is positioned closest to the viewing surface. However, when the surface to be coated with the antireflection film, for example, the display surface of the image display device, is only provided with a single light transmission layer, the balance between the refractive index of the coating surface itself and the refractive index of the light transmission layer is just right. Since an antireflection effect is obtained, an antireflection film having a single-layer structure can be formed.
[0104]
The antireflection film is usually provided with a hard coat layer on the surface of a support such as a base film or an image display medium for the purpose of imparting sufficient hardness to the antireflection film. A high refractive index layer, a medium refractive index layer, and a low refractive index layer as described above are provided above.
[0105]
In some cases, a high refractive index hard coat layer having both sufficient hardness and high refractive index and capable of exhibiting a function as a hard coat layer and a function as a medium to high refractive index layer may be provided. In this case, at least the high refractive index hard coat layer and the low refractive index layer may be provided, and the high refractive index layer and / or one or more medium refractive index layers may be further provided. The hard coat layer, the high refractive index layer, the medium refractive index layer and the low refractive index layer are alternately switched in refractive index, and the high refractive index hard coat layer is located closest to the contact surface with the display medium, and By laminating so that the low refractive index layer is located closest to the viewing surface, an antireflection film can be obtained.
[0106]
Further, the antireflection film is provided with a transparent conductive layer made of ITO, ATO or the like for the purpose of imparting an antistatic function, or made of a fluorine-based surfactant or a fluorine-based silicone coating agent on the surface of the low refractive index layer. An antifouling layer may be provided.
[0107]
Each of the various layers described above is a light-transmitting layer having light transmittance, and the antireflection film has a single-layer structure composed of one light-transmitting layer having light transmittance, or has light transmittance and It has a multilayer structure in which two or more light transmission layers having different refractive indexes are laminated. The coating film according to the present invention can be used to form one or more of these light transmission layers.
[0108]
Therefore, the coating composition according to the present invention is applied to the surface to be coated with the coating composition and cured, so that it has a single-layer structure consisting of one light-transmitting layer having light transmittance, or light-transmitting property. And having a multilayer structure in which two or more light transmission layers having different refractive indexes are laminated,
At least one of the light transmission layers is coated with an inorganic compound that reduces or eliminates the photocatalytic activity and an organic compound and / or an organic metal compound having an anionic polar group, and is in the range of 0.01 to 0.1 μm. An antireflection film is obtained, which is a cured layer in which a rutile-type titanium oxide having a particle size and a dispersant having an anionic polar group are uniformly mixed in a cured binder.
[0109]
The cured layer is excellent in transparency and can have a refractive index of 1.55 or more, and is mainly used as a middle refractive index layer, but it can also be used as a high refractive index layer or a high refractive index hard coat layer. it can. In the multilayer antireflection film, the layer having the highest refractive index is referred to as the high refractive index layer, the layer having the lowest refractive index is referred to as the low refractive index layer, and the other layers having an intermediate refractive index are referred to. This is called a medium refractive index layer.
[0110]
When the above hardened layer is used as a high refractive index hard coat layer, the surface of the high refractive index hard coat layer is formed into a fine concavo-convex shape to serve as a hard coat layer that functions as an antiglare layer (antiglare layer). Good. The fine concavo-convex shape on the surface of the high refractive index hard coat layer is a high refractive index in which a coating composition for a high refractive index hard coat layer is applied to a substrate and embossed or an inorganic or organic filler is dispersed. It can provide by coating the coating composition for a rate hard-coat layer on a base material.
[0111]
The difference Δn in refractive index between the refractive index of the filler added to form the surface of the cured layer as a high refractive index hard coat layer in a fine irregular shape and the cured binder is 0.01 ≦ Δn ≦ If the average particle size d of the filler is 0.5 μm ≦ d ≦ 10 μm, preferably 1 μm ≦ d ≦ 5 μm, the uneven shape of the antiglare layer and the transmitted light from the display The resulting “glare” can be effectively suppressed, and the display has a better visibility.
[0112]
In particular, a coating composition containing 4 to 20 parts by weight of the binder component having an anionic polar group in the molecule and 2 to 4 parts by weight of a dispersant with respect to 10 parts by weight of titanium oxide. By using it, the film thickness is 0.05 to 0.2 μm, the refractive index is 1.55 to 2.30, and the haze value defined in JIS-K7361-1 is the haze value of only the base material. It is possible to form a high refractive index layer and / or a medium refractive index layer that does not change or has a difference from the haze value of only the base material within 1%.
[0113]
Further, a coating composition containing 70 to 320 parts by weight of the binder component having an anionic polar group in the molecule and 2 to 4 parts by weight of a dispersant with respect to 10 parts by weight of titanium oxide. By using, the film thickness is 1 to 10 μm, the refractive index is 1.55 to 1.83, and the haze value specified in JIS-K7361-1 is not different from the haze value of the base material alone or A high refractive index hard coat layer having a difference from the haze value of only the substrate within 3% can be formed.
[0114]
The coating composition according to the present invention is applied to a support on which one or two or more light-transmitting layers have been formed in advance, if necessary, dried, and then cured by irradiation with ionizing radiation. Rutile-type titanium oxide having a primary particle diameter in the range of 0.01 to 0.1 μm and anion coated with an inorganic compound that lowers or disappears and an organic compound and / or organometallic compound having an anionic polar group A coating film is formed by uniformly dispersing a dispersing agent having a polar group in a cured binder, and an antireflection film having a cured layer made of such a coating film is obtained.
[0115]
When the high refractive index layer and / or the middle refractive index layer is formed using the coating composition according to the present invention, the film thickness is 0.05 to 0.2 μm and the refractive index is 1.55 to 2.30. And the haze value prescribed | regulated to JIS-K7361-1 does not change with the haze value only of the said base material, or the difference with the haze value only of the said base material is less than 1%. Can be formed.
[0116]
Moreover, when forming a high refractive index hard-coat layer using the coating composition which concerns on this invention, a film thickness is 1-10 micrometers, a refractive index is 1.55-1.83, and JIS-K7361. It is possible to form a high refractive index hard coat layer in which the haze value defined in -1 is not different from the haze value of the base material alone or the difference from the haze value of the base material alone is within 3%.
[0117]
The coating film according to the present invention is a multilayer that covers the display surface of an image display device such as a liquid crystal display device (LCD), a cathode ray tube display device (CRT), a plasma display panel (PDP), or an electroluminescence display (ELD). It is suitably used for forming at least one layer of a type antireflection film, particularly a medium refractive index layer and / or a high refractive index layer.
[0118]
FIG. 1 schematically shows a cross section of an example (101) of a liquid crystal display device in which a display surface is covered with a multilayer antireflection film containing a coating film according to the present invention as a light transmission layer. The liquid crystal display device 101 prepares a color filter 4 in which an RGB pixel portion 2 (2R, 2G, 2B) and a black matrix layer 3 are formed on one surface of a glass substrate 1 on the display surface side, and the pixel of the color filter. The transparent electrode layer 5 is provided on the part 2, the transparent electrode layer 7 is provided on one surface of the glass substrate 6 on the backlight side, and the transparent electrode layers 5 and 7 face each other with the glass substrate on the backlight side and the color filter. The liquid crystal L is sealed in the gap, the alignment film 9 is formed on the outer surface of the glass substrate 6 on the back side, and the glass substrate on the display surface side. The polarizing film 10 is affixed on the outer surface of 1, and the backlight unit 11 is arrange | positioned back.
[0119]
FIG. 2 schematically shows a cross section of the polarizing film 10 attached to the outer surface of the glass substrate 1 on the display surface side. The polarizing film 10 on the display surface side covers both surfaces of a polarizing element 12 made of polyvinyl alcohol (PVA) or the like with protective films 13 and 14 made of triacetyl cellulose (TAC) or the like, and an adhesive layer 15 is coated on the back side thereof. The hard coat layer 16 and the multilayer antireflection film 17 are sequentially formed on the viewing side, and are adhered to the glass substrate 1 on the display surface side through the adhesive layer 15.
[0120]
The hard coat layer 16 can be formed by a method such as gravure coating by diluting a polyfunctional acrylic monomer such as dipentaerythritol hexaacrylate (DPHA) in a solvent. The surface of the hard coat layer 16 is formed in a fine uneven shape by embossing or by dispersing inorganic or organic filler in the hard coat layer 16 to scatter light from the outside. A hard coat layer that functions as an antiglare layer (antiglare layer) having a function may be used.
[0121]
Further, the difference Δn between the refractive index of the filler added to form the surface of the hard coat layer 16 in a fine uneven shape and the refractive index of the binder resin is 0.01 ≦ Δn ≦ 0.5, and the average of the fillers When the particle size d is usually 0.1 μm ≦ d ≦ 10 μm, preferably 1 μm ≦ d ≦ 5 μm, the uneven shape of the antiglare layer and “glare” caused by transmitted light from the display are effectively suppressed. The display can be made more visible.
[0122]
The multilayer antireflection film 17 has a three-layer structure in which a middle refractive index layer 18, a high refractive index layer 19, and a low refractive index layer 20 are sequentially laminated from the backlight side to the viewing side. The multilayer antireflection film 17 may have a two-layer structure in which a high refractive index layer 19 and a low refractive index layer 20 are sequentially stacked. When the surface of the hard coat layer 16 is formed in an uneven shape, the multilayer antireflection film 17 formed thereon also has an uneven shape as shown in the drawing.
[0123]
The low refractive index layer 20 is formed by chemically coating a coating film having a refractive index of 1.46 or less obtained from a coating liquid containing an inorganic material such as silica or magnesium fluoride, a fluorine resin, or the like, or silica or magnesium fluoride. It can be set as the vapor deposition film using vapor deposition methods, such as a vapor deposition method (CVD) and a physical vapor deposition method (PVD). Further, the medium refractive index layer 18 and the high refractive index layer 19 can be formed using the coating film according to the present invention, and the medium refractive index layer 18 has light in the range of refractive index 1.50 to 1.80. For the transmission layer and the high refractive index layer 19, a light transmission layer having a refractive index of 1.65 or more is used.
[0124]
Due to the action of the antireflection film, the reflectance of light emitted from the external light source is reduced, so that the reflection of scenery and fluorescent light is reduced and the visibility of the display is improved. Moreover, the reflected light of external light is reduced by the light scattering effect by the unevenness | corrugation of the hard-coat layer 16, and the visibility of a display improves further that external light is reflected on the display surface, or is a dazzling state. .
[0125]
In the case of the liquid crystal display device 101, the refractive index is adjusted in the range of 1.50 to 1.80 by applying the coating composition according to the present invention to the laminate comprising the polarizing element 12 and the protective films 13 and 14. A refractive index layer 18 and a high refractive index layer 19 having a refractive index adjusted to 1.65 or more can be formed, and a low refractive index layer 20 can be further provided. Then, the polarizing film 10 including the antireflection film 17 can be stuck on the glass substrate 1 on the viewing side through the adhesive layer 15.
[0126]
On the other hand, since an alignment plate is not attached to the display surface of the CRT, it is necessary to directly provide an antireflection film. However, applying the coating composition according to the present invention to the display surface of the CRT is a complicated operation. In such a case, an antireflective film containing the coating film according to the present invention is prepared, and the antireflective film is formed by sticking it to the display surface. Therefore, the coating according to the present invention is formed on the display surface. There is no need to apply the composition.
[0127]
Two or more light-transmitting layers having light transmittance and different refractive indexes are laminated on one side or both sides of a base film having light transmittance, and at least one of the light-transmitting layers is By forming the coating film according to the present invention, an antireflection film is obtained. The base film and the light transmission layer need to have a light transmittance that can be used as a material for the antireflection film, and are preferably as transparent as possible.
[0128]
FIG. 3 schematically shows a cross section of an example (102) of the antireflection film including the coating film according to the present invention. The antireflection film 102 is formed by applying the coating composition according to the present invention on one surface side of the base film 21 having light transmittance to form the high refractive index layer 22, and further forming a low refractive index layer on the high refractive index layer. A refractive index layer 23 is provided. In this example, there are only two light transmissive layers having different refractive indexes, a high refractive index layer and a low refractive index layer, but three or more light transmissive layers may be provided. In that case, not only the high refractive index layer but also the middle refractive index layer can be formed by applying the coating composition according to the present invention.
[0129]
【Example】
Example 1
(1) Preparation of coating composition
As rutile type titanium oxide, titanium oxide content is 79-85%, Al₂O_ThreeSurface treatment with stearic acid, primary particle size 0.01-0.03 μm, specific surface area 50-60 m²Rutile titanium oxide (TTO51 (C), manufactured by Ishihara Sangyo Co., Ltd.) having an oil absorption of 24 to 30 g / 100 g and a water-repellent surface was prepared. As an ionizing radiation curable binder component, pentaerythritol triacrylate (PET30, manufactured by Nippon Kayaku Co., Ltd.) was prepared. As a dispersant having an anionic polar group, a block copolymer having an affinity for pigment (Dispervic 163, manufactured by Big Chemie Japan) was prepared. As a photoinitiator, 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Geigy Japan) was prepared. As an organic solvent, methyl isobutyl ketone was prepared.
[0130]
Rutile type titanium oxide, pentaerythritol triacrylate, dispersant (Disperbic 163) and methyl isobutyl ketone are put into a mayonnaise bottle, and about 4 times the amount of zirconia beads (φ0.3 mm) as a mixture is used as a paint shaker. The photoinitiator (Irgacure 184) was added after stirring for 10 hours to obtain a coating composition having the following composition.
<Composition of coating composition>
・ Rutile titanium oxide (Al₂O_ThreeAnd surface treated product with stearic acid, primary particle size 0.01-0.03 μm (TTO51 (C), manufactured by Ishihara Sangyo Co., Ltd.): 10 parts by weight
Pentaerythritol triacrylate (PET30, Nippon Kayaku Co., Ltd.): 4 parts by weight
Anionic group-containing dispersant (Disperbic 163, manufactured by Big Chemie Japan): 2 parts by weight
Photoinitiator (Irgacure 184, manufactured by Ciba Geigy Japan): 0.2 parts by weight
・ Methyl isobutyl ketone: 37.3 parts by weight
(2) Creation of coating film
After forming a cured film of pentaerythritol triacrylate having a thickness of 3 μm on a triacetyl cellulose film having a thickness of 80 μm (FT-T80UZ, manufactured by Fuji Photo Film Co., Ltd.), the coating composition immediately after the preparation was prepared with a bar coater # 2. After coating and drying at 60 ° C. for 1 minute, the film was cured by UV irradiation of 500 mJ to form a transparent film having a thickness of 0.1 μm after curing.
[0131]
Further, for the haze measurement, the coating composition immediately after the preparation was applied with a bar coater # 2 on a surface untreated PET base material (Lumilar T60 manufactured by Toray Industries, Inc.) having a thickness of 50 μm, and at 60 ° C. for 1 minute. After heat drying, the film was cured by 500 mJ UV irradiation to form a transparent film having a thickness of 0.1 μm after curing.
[0132]
In addition, the coating composition was allowed to stand at room temperature for 30 days to observe the occurrence of precipitation. Further, using the coating composition after leaving, the surface untreated PET substrate (Toray Industries, Inc.) having a thickness of 50 μm was used in the same manner as described above. ) A transparent film was formed on Lumirror T60).
[0133]
The haze and refractive index of the transparent film having a cured film thickness of 0.1 μm formed from each of the coating compositions immediately after preparation and after standing at room temperature were measured. The haze was measured using a turbidimeter NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). Moreover, the refractive index of the coating film after hardening measured the refractive index in wavelength 633nm of helium laser beam using the spectroscopic ellipsometer (UVSEL, the product made from Joban-Evon).
[0134]
The results of each test are shown in Table 1. When the coating composition prepared in Example 1 was used, a transparent film having good haze and refractive index was obtained. Moreover, the coating composition of Example 1 was excellent in dispersibility even after being allowed to stand at room temperature, and a transparent film having a good haze and refractive index was obtained in the same manner as immediately after preparation.
[0135]
(Comparative Example 1)
In Example 1, instead of rutile titanium oxide subjected to hydrophobic treatment (TTO51 (C), manufactured by Ishihara Sangyo Co., Ltd.), the titanium oxide content is 76 to 83%, Al₂O_ThreeSurface treatment, primary particle size 0.01-0.03 μm, specific surface area 75-85 m²/ G, the amount of oil absorption is 40 to 47 g / 100 g, and the surface is hydrophilic, and the same procedure is used as in Example 1 except that the same amount of rutile titanium oxide (TTO51 (A), manufactured by Ishihara Sangyo) is used. A coating composition was obtained. The resulting coating composition was tested as in Example 1.
[0136]
The test results are shown in Table 1. A coating film was formed using the coating composition of Comparative Example 1 immediately after preparation, but the obtained coating film had high haze and low refractive index. In addition, a large amount of precipitation occurred upon standing at room temperature. In addition, the coating film formation after standing at room temperature was stopped.
[0137]
(Comparative Example 2)
In Example 1, instead of pentaerythritol triacrylate, the coating composition was carried out in the same manner as in Example 1 except that the same amount of pentaerythritol tetraacrylate having no hydroxyl group (PET-40, manufactured by Nippon Kayaku Co., Ltd.) was used. I got a thing. The resulting coating composition was tested as in Example 1.
[0138]
The test results are shown in Table 1 as Comparative Example 2-1. The obtained coating composition had poor dispersibility and was already gelled immediately after preparation, and a uniform thin film could not be formed. Measurement of haze and refractive index and observation at room temperature were stopped.
[0139]
Therefore, the coating composition was prepared by increasing the amount of the anionic group-containing dispersant (Disperbic 163, manufactured by Big Chemie Japan) used in Example 1 to 6 parts by weight, and the same test as in Example 1 was performed. The test results of this coating composition are shown in Table 1 as Comparative Example 2-2. In this case, the rutile-type titanium oxide was uniformly dispersed, and no change in viscosity or appearance of a precipitate was observed even when allowed to stand at room temperature. When a coating film was formed using the sample immediately after preparation and the sample after standing at room temperature, the haze of the obtained coating film was good. However, the refractive index of Comparative Example 2-2 was lower than that of Example 1, and the strength of the coating film was extremely low.
[0140]
(Comparative Example 3)
In Example 1, as rutile titanium oxide, Al₂O_ThreeInstead of using rutile type titanium oxide (TTO51 (C), manufactured by Ishihara Sangyo Co., Ltd.) having a primary particle size of 0.01 to 0.03 μm surface-treated with stearic acid, a primary particle size of 0.01 to 0.03μm but Al₂O_ThreeThe coating composition was obtained in the same manner as in Example 1 except that the same amount of rutile-type titanium oxide (TT051 (N), manufactured by Ishihara Sangyo Co., Ltd.) that was not subjected to any surface treatment was used. The resulting coating composition was tested as in Example 1.
[0141]
The obtained coating composition had poor dispersibility and was already gelled immediately after preparation, and a uniform thin film could not be formed. Measurement of haze and refractive index and observation at room temperature were stopped.
[0142]
(Adhesion with the deposited film)
After forming a cured film of pentaerythritol triacrylate having a thickness of 3 μm on a triacetyl cellulose film having a thickness of 80 μm (FT-T80UZ, manufactured by Fuji Photo Film Co., Ltd.), it is obtained in Example 1 and Comparative Example 2-2. The coated composition was applied with a bar coater # 2, heated and dried at 60 ° C. for 1 minute, and then cured by 500 mJ UV irradiation to form a transparent film having a thickness of 0.1 μm after curing. Next, a 84.7 μm-thick silica deposited film was formed by the PVD method under the following conditions.
<PVD process conditions>
・ Target for thermal evaporation: silicon monoxide (purity 99.9%)
Output: current value 0.4A, voltage 480V
・ Vacuum degree in the vacuum chamber: 0.13 Pa
Argon flow rate: 38.8sccm
・ Oxygen flow rate: 5 sccm
・ Vapor deposition rate: 8.47 nm / min
An adhesion test (cellophane tape cross-cut peel test) described later was performed on the obtained deposited film. The test results are shown in Table 2. The silica vapor deposition film coated on the cured film formed from the coating composition of Comparative Example 2-2 was peeled off entirely, whereas the silica vapor deposition film coated with the cured film formed from the coating composition of Example 1 was It did not peel at all and showed good adhesion to the coating film.
[0143]
[Table 1]

[0144]
[Table 2]

[0145]
(Example 2)
In this example, an antireflection film F1 having the structure shown in FIG. 4 was prepared. The antireflection film F1 has a configuration in which a clear hard coat layer 25, a medium refractive index layer 26, a high refractive index layer 27, and a low refractive index layer 28 are sequentially laminated on a base film 24, and a high refractive index layer thereof And a medium refractive index layer were formed using the coating composition according to the present invention.
[0146]
(1) Preparation of coating solution for high refractive index layer
As rutile titanium oxide, Al₂O_Three100 parts of rutile type titanium oxide coated with stearic acid and having a primary particle size of about 0.03 μm was prepared. As an ionizing radiation curable binder component, 20 parts of pentaerythritol triacrylate (PET30, Nippon Kayaku Co., Ltd.) was prepared. As a dispersant, 20 parts of a dispersant (Ajisper PA111, manufactured by Ajinomoto Co., Inc.) having an ethylene oxide chain and an anionic polar group were prepared.
[0147]
These materials were mixed with methyl isobutyl ketone to a solid content concentration of 15% by weight, and zirconia balls were added as a dispersion medium thereto, followed by stirring for 7 hours or more in a paint shaker.
[0148]
After adding 3 parts of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184) as a photoinitiator to the obtained dispersion, methyl isobutyl ketone was added to dilute the solid content concentration to 3% by weight, A coating solution for a high refractive index layer having a refractive index of 1.90 was obtained.
[0149]
(2) Preparation of coating solution for middle refractive index layer
Three parts of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184) was added as a photoinitiator to the dispersion obtained by stirring with a paint shaker. After adding 60 parts of dipentaerythritol pentaacrylate (DPPA) to 100 parts of this mixed solution, methyl isobutyl ketone was added to dilute the solid content concentration to 3% by weight. A coating solution for the refractive index layer was obtained.
[0150]
(3) Coating and curing
On a PET (polyethylene terephthalate) substrate, a clear hard coat layer made of dipentaerythritol hexaacrylate (DPHA) having a refractive index of 1.52 and a thickness of 3 μm or more after drying was applied. On the obtained clear hard coat layer, the above medium refractive index layer coating solution (refractive index 1.76) is applied to form a medium refractive index layer having a refractive index of 1.76 and a thickness of 60 nm after drying. Further, the high refractive index layer coating liquid (refractive index 1.90) was applied thereon to form a high refractive index layer having a refractive index of 1.90 and a thickness of 80 nm after drying, and UV cured. Thereafter, a low-refractive index layer having a refractive index of 1.42 made of a silicon-containing vinylidene fluoride copolymer and a thickness of 100 nm after drying was applied on the high-refractive index layer to obtain an antireflection film.
[0151]
(4) Evaluation
About the antireflection film obtained by Example 2, the reflectance, pencil hardness, adhesion, and coating spots were evaluated by the following methods. The layer configuration and evaluation results of the antireflection film are shown in Tables 3 and 4, respectively.
[0152]
The antireflection film obtained in Example 2 had a visible light reflectance of 450 to 650 nm of 0.4 to 0.7%. The antireflection film had a pencil hardness of 3H.
[0153]
In addition, if spots occur when applying the coating solution for the medium refractive index layer on the clear hard coat layer, the layer of the lower layer is added each time the layer is layered such as a high refractive index layer or a low refractive index layer. In the present embodiment, a uniform thin film on the clear hard coat layer can be obtained by changing the solvent. The coating performance was improved and the occurrence of spots was suppressed.
[0154]
<Evaluation method>
(A) Reflectance
Black vinyl tape was attached to the back surface of the sample in consideration of the influence of back surface reflection, and the reflectance of 380 nm to 780 nm was measured with a spectrophotometer. In the case of one-point measurement, a value of a wavelength of 550 nm that humans feel most dazzling was shown.
[0155]
(B) Hardness
Pencil hardness was measured according to JIS 5400. That is, about five writings were performed with a pencil with a 1 kg load applied to the sample, and four of the five were evaluated to have the same hardness as the hardest pencil that would be intact.
[0156]
(C) Adhesion
A cellophane tape cross-cut peel test was performed in accordance with JIS 5400. That is, 11 vertical x 11 horizontal scratches were made to be orthogonal to the coating film surface with a cutter, and 100 grids having a 1 mm width were provided. The Nichiban cellophane tape was tightly adhered from above, and then peeled off 5 times in succession, and the number of cells remaining on the film surface was counted.
[0157]
(D) Coating spots
The sample was illuminated with a 3 line fluorescent lamp from a height of 3 to 5 mm, and the presence or absence of coating spots (because of interference films, spots, that is, different interference colors are visible) was observed.
[0158]
Example 3
In this example, an antireflection film F2 having the structure shown in FIG. 5 was prepared. The antireflection film F2 has a structure in which a clear hard coat layer 25, a high refractive index layer 27, and a low refractive index layer 28 are sequentially laminated on a base film 24, and the high refractive index layer is coated according to the present invention. Formed with the composition.
[0159]
(1) Preparation of coating solution for high refractive index layer
As rutile titanium oxide, ZrO₂100 parts of rutile type titanium oxide coated with stearic acid and having a primary particle size of about 0.03 μm was prepared. As an ionizing radiation curable binder component, 40 parts of pentaerythritol triacrylate (PET30, manufactured by Nippon Kayaku Co., Ltd.) was prepared. As the dispersant, 20 parts of a dispersant having an ethylene oxide chain and an anionic polar group was prepared.
[0160]
These materials were mixed with methyl isobutyl ketone to a solid content concentration of 15% by weight, and zirconia balls were added as a dispersion medium thereto, followed by stirring for 7 hours or more in a paint shaker.
[0161]
After adding 3 parts of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184) and 40 parts of pentaerythritol pentaacrylate (DPPA) as a photoinitiator to the obtained dispersion, methyl isobutyl ketone was added. The solid content concentration was diluted to 2% by weight to obtain a coating solution for a high refractive index layer having a refractive index of 1.76.
[0162]
(2) Coating and curing
A clear hard coat layer made of pentaerythritol triacrylate having a refractive index of 1.51 and a thickness of 3 μm or more after drying is coated on a TAC (triacetylcellulose) substrate, and the high refractive index layer is further formed thereon. The coating liquid (refractive index 1.76) was applied to form a high refractive index layer having a refractive index of 1.76 and a thickness of 90 nm after drying, and UV cured. Thereafter, a low refractive index layer made of a silicon-containing vinylidene fluoride copolymer having a refractive index of 1.42 and a thickness of 90 nm after drying was coated on the high refractive index layer to obtain an antireflection film.
[0163]
(3) Evaluation
The antireflection film obtained in Example 3 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflection film obtained in Example 3 had a reflectivity of 0.4% at a wavelength of 550 nm at which humans are most likely to feel glare. Moreover, this antireflection film had a pencil hardness of 2H.
[0164]
(Example 4)
In this example, an antireflection film F3 having the structure shown in FIG. 6 was prepared. The antireflection film F3 has a structure in which a mat hard coat layer 29 containing a filler 30 on a base film 24, a high refractive index layer 27, and a low refractive index layer 28 are sequentially laminated. It formed using the coating composition which concerns on this invention.
[0165]
(1) Preparation of coating solution for high refractive index layer
In Example 2, when preparing a coating solution for the medium refractive index layer having a refractive index of 1.76, the same procedure was followed except that the solvent was changed from methyl isobutyl ketone (MIBK) to a mixed solvent of 95 parts MIBK and 5 parts butyl cellosolve. A coating solution for a high refractive index layer having a refractive index of 1.76 was obtained.
[0166]
(2) Coating and curing
A matt hard coat layer coating liquid having a refractive index of 1.52 having the following composition is applied onto a TAC substrate, UV-cured to such an extent that no surface tack remains, a refractive index of 1.52, and a thickness of 3 μm after drying. In addition, an anti-glare mat hard coat layer having fine irregularities was formed.
<Coating liquid for matte hard coat layer>
Pentaerythritol triacrylate: 2 parts
Styrene paste (pentaerythritol triacrylate / beads = 6/4, particle size 3.5 μm): 0.5 parts
Cellulose acetate polypropionate (CAP) (ethyl acetate solution having a solid content of 10% by weight): 2.3 parts
Solvent (toluene / cyclohexanone = 7/3): 4.4 parts
Initiator (Irgacure 651): 0.06 g
The fine concavo-convex surface of the obtained mat hard coat layer is coated with the above coating solution for high refractive index layer (refractive index 1.76), UV cured, having a refractive index of 1.76 and a thickness of 60 nm after drying. A high refractive index layer was formed. Thereafter, a low refractive index layer having a refractive index of 1.42 made of a silicon-containing vinylidene fluoride copolymer and a thickness of 90 nm after drying is coated on the high refractive index layer, and then completely cured with UV, thereby preventing reflection. Got.
[0167]
(3) Evaluation
The antireflection film obtained in Example 4 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflection film obtained in Example 4 had a reflectance of 0.6% at a wavelength of 550 nm at which humans are most likely to feel glare. Moreover, this antireflection film had a pencil hardness of 2H.
[0168]
Further, in this example, by changing the solvent, the suitability of the mat hard coat layer having a fine uneven surface was improved, and the coating liquid for the high refractive index layer could be applied without causing spots.
[0169]
(Example 5)
In this example, an antireflection film F4 having the structure shown in FIG. 7 was prepared. The antireflection film F4 has a configuration in which a transparent conductive layer 31, an anisotropic conductive mat hard coat layer 29 containing a filler 30, a high refractive index layer 27, and a low refractive index layer 28 are sequentially laminated on a base film 24. Among them, the high refractive index layer was formed using the coating composition according to the present invention.
[0170]
(1) Coating and curing
In Example 4, a transparent conductive layer was provided on the TAC substrate, and gold-nickel resin beads (Bright GNR4.6-EH, manufactured by Nippon Chemical Industry Co., Ltd.) as a conductive material in the mat hard coat layer coating solution were added in an amount of 0.0. The same operation as in Example 4 was carried out except that 005 parts was added.
[0171]
That is, an ATO-containing transparent conductive ink (manufactured by Sumitomo Osaka Cement, Sumise Fine ASP-BJ-l) is applied onto a TAC substrate, UV-cured to the extent that no surface tack remains, and a transparent conductive layer having a dry film thickness of 2 μm Formed. On the obtained transparent conductive layer, a coating liquid for a mat hard coat layer to which a conductive material is added is applied, UV cured, a refractive index of 1.52, a thickness of 3 to 4 μm after drying, and fine An antiglare anisotropic conductive mat hard coat layer having irregularities was formed.
[0172]
Next, a coating liquid for a high refractive index layer (refractive index 1.76) is applied on the obtained mat hard coat layer, UV cured, a refractive index of 1.76, and a thickness of 60 nm after drying. A high refractive index layer was formed. Thereafter, a low refractive index layer having a refractive index of 1.42 made of a silicon-containing vinylidene fluoride copolymer and a thickness of 90 nm after drying is formed on the high refractive index layer, and the antireflection film is completely cured by UV. Obtained.
[0173]
(2) Evaluation
The antireflection film obtained in Example 5 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflection film obtained in Example 5 had a reflectance of 0.6% at a wavelength of 550 nm at which humans are most likely to feel glare. Moreover, this antireflection film had a pencil hardness of 2H.
[0174]
(Example 6)
In this example, an antireflection film F5 having the configuration shown in FIG. 8 was prepared. The antireflective film F5 has a structure in which a high refractive index clear hard coat layer 32, a high refractive index layer 27, and a low refractive index layer 28 are sequentially laminated on a base film 24, and a high refractive index clear hard coat layer among them. And a high refractive index layer was formed using the coating composition according to the present invention.
[0175]
(1) Preparation of coating solution for high refractive index layer
As rutile titanium oxide, ZrO₂100 parts of rutile type titanium oxide coated with stearic acid and having a primary particle size of about 0.03 μm was prepared. As an ionizing radiation curable binder component, 40 parts of pentaerythritol triacrylate (PET30, manufactured by Nippon Kayaku Co., Ltd.) was prepared. As the dispersant, 20 parts of a dispersant having an ethylene oxide chain and an anionic polar group was prepared.
[0176]
These materials were mixed with methyl isobutyl ketone to a solid content concentration of 15% by weight, and zirconia balls were added as a dispersion medium thereto, followed by stirring for 7 hours or more in a paint shaker.
[0177]
After adding 3 parts of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184) and 40 parts of dipentaerythritol pentaacrylate (DPPA) as a photoinitiator to the obtained dispersion, methyl isobutyl ketone was added. The solid content concentration was diluted to 3% by weight to obtain a coating solution for a high refractive index layer having a refractive index of 1.84.
[0178]
(2) Preparation of coating liquid for high refractive index clear hard coat layer
3 parts of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184) was added as a photoinitiator to the above dispersion obtained by stirring with a paint shaker. To 100 parts of this mixture, 20 parts of dipentaerythritol pentaacrylate (DPPA) and 55 parts of pentaerythritol triacrylate are sufficiently mixed to obtain a coating liquid for a high refractive index clear hard coat layer having a refractive index of 1.70. It was. Since this coating liquid has good dispersibility, the haze difference from the base film was 0.01 even when the binder amount was increased.
[0179]
(3) Coating and curing
On the TAC substrate, the above high refractive index clear hard coat layer coating liquid having a refractive index of 1.70 is applied, UV-cured to such an extent that no surface tack remains, refractive index 1.70, thickness after drying A 5 μm high refractive index clear hard coat layer was formed. Then, a coating solution for a high refractive index layer having a refractive index of 1.84 is applied on the high refractive index clear hard coat layer, UV-cured, and having a refractive index of 1.84 and a thickness of 60 nm after drying. A rate layer was formed. Thereafter, a low refractive index layer having a refractive index of 1.42 made of a silicon-containing vinylidene fluoride copolymer and a thickness of 90 nm after drying is formed on the high refractive index layer, and the antireflection film is completely cured by UV. Obtained.
[0180]
(4) Evaluation
The antireflection film obtained in Example 6 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflection film obtained in Example 6 had a reflectance of 0.2% at a wavelength of 550 nm at which humans are most likely to feel glare. Moreover, this antireflection film had a pencil hardness of 2H.
[0181]
(Example 7)
In this example, an antireflection film F6 having the structure shown in FIG. 9 was prepared. The antireflection film F6 has a structure in which a high refractive index mat hard coat layer 33 containing a filler 30 and a low refractive index layer 28 are sequentially laminated on a base film 24, and the high refractive index mat hard coat layer of these layers is formed. It formed using the coating composition which concerns on this invention.
[0182]
(1) Preparation of coating liquid for high refractive index mat hard coat layer
A clear hard coat layer coating liquid having a refractive index of 1.70 was prepared in the same manner as in Example 6, and the resulting coating liquid was used for a high refractive index mat hard coat layer having a refractive index of 1.66 having the following composition. A coating solution was obtained. The dispersibility of rutile titanium oxide ultrafine particles is stable even when mat materials (acrylic beads) or binders are added, and the haze difference from the base film is a coating for high refractive index mat hard coat layers containing mat materials. The solution was applied, the surface was laminated with untreated PET, and peeled after UV curing, and the measurement was made to have no uneven shape. The result was 0.01.
<Coating liquid for high refractive index mat hard coat layer>
-Coating liquid for clear hard coat layer with a refractive index of 1.70 (solid content 50 wt%): 4 parts
Acrylic paste (pentaerythritol triacrylate / bead = 6/4, particle size 3.5 μm): 0.5 part
Cellulose acetate polypropionate (CAP) (ethyl acetate solution having a solid content of 10% by weight): 2.3 parts
Solvent (toluene): 2.4 parts
Initiator (Irgacure 651): 0.06 part
(2) Coating and curing
On the TAC substrate, the above-described coating liquid for high refractive index mat hard coat layer having a refractive index of 1.66 is applied, UV-cured to such an extent that no surface tack remains, has a fine uneven surface, and has a refractive index of 1 .66, after drying, a high refractive index mat hard coat layer having a thickness of 3 μm was formed. On the obtained high refractive index mat hard coat layer, a low refractive index layer made of silicon-containing vinylidene fluoride copolymer having a refractive index of 1.42 and a thickness of 90 nm after drying is applied and completely cured with UV. Thus, an antireflection film was obtained.
[0183]
(3) Evaluation
The antireflection film obtained in Example 7 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflection film obtained in Example 7 had a reflectance of 0.8% at a wavelength of 550 nm at which humans are most likely to feel glare. Moreover, this antireflection film had a pencil hardness of 2H.
[0184]
(Example 8)
In this example, an antireflection film F7 having the configuration shown in FIG. 10 was prepared. The antireflection film F7 has a configuration in which a high refractive index mat hard coat layer 33 containing a filler 30 on a base film 24, a high refractive index layer 27, and a low refractive index layer 28 are sequentially laminated. A refractive index mat hard coat layer and a high refractive index layer were formed using the coating composition according to the present invention.
[0185]
(1) Coating and curing
On the TAC substrate, the coating liquid for high refractive index mat hard coat layer having a refractive index of 1.66 obtained in Example 7 was applied, having a fine uneven surface, refractive index of 1.66, thickness after drying. A 3 μm high refractive index mat hard coat layer was formed. Furthermore, the coating liquid for the high refractive index layer having a refractive index of 1.84 obtained in Example 3 was applied thereon, UV-cured to such an extent that no surface tack remained, and the refractive index was 1.84, after drying. A high refractive index layer having a thickness of 180 nm was formed. On the obtained high refractive index layer, a low refractive index layer having a refractive index of 1.40 made of a silicon-containing vinylidene fluoride copolymer and a thickness of 90 nm after drying is applied, and reflected by being completely cured with UV. A prevention film was obtained.
[0186]
(2) Evaluation
The antireflection film obtained in Example 8 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflection film obtained in Example 8 had a reflectance of 0.5% at a wavelength of 550 nm at which a human being most likely to feel glare. Moreover, this antireflection film had a pencil hardness of 2H.
[0187]
Example 9
In this example, an antireflection film F8 having the configuration shown in FIG. 11 was prepared. The antireflection film F8 has a structure in which a high refractive index mat hard coat layer 33 containing a filler 30, a high refractive index layer 27, a low refractive index layer 28, and an antifouling layer 34 are sequentially laminated on the base film 24. Among them, a high refractive index mat hard coat layer and a high refractive index layer were formed using the coating composition according to the present invention.
[0188]
(1) Coating and curing
The same procedure as in Example 8 was performed until a high refractive index mat hard coat layer having a refractive index of 1.66 and a high refractive index layer having a refractive index of 1.84 were formed on the TAC substrate. Further, a sol-gel SiO2 coating liquid for a low refractive index layer having a refractive index of 1.45 is formed on a high refractive index layer having a refractive index of 1.84.₂The ink was coated, dried at 80 ° C. for 1 minute, and then aged at 40 ° C. for 1 week to be completely cured. On the obtained low refractive index layer, a fluorine-based antifouling material was coated to form an antifouling layer to obtain an antireflection film.
[0189]
(2) Evaluation
The antireflection film obtained in Example 9 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflection film obtained in Example 9 had a reflectance of 1.2% at a wavelength of 550 nm at which humans are most likely to feel glare. The antireflection film had a pencil hardness of 3H.
[0190]
(Example 10)
In this example, an antireflection film F9 having the structure shown in FIG. 12 was prepared. The antireflection film F9 has a configuration in which a clear hard coat layer 25, a medium refractive index layer 26, a high refractive index layer 27, and a low refractive index layer 28 are sequentially laminated on a base film 24, and a medium refractive index layer thereof Was formed using the coating composition according to the present invention.
[0191]
(1) Coating and curing
A clear hard coat layer made of dipentaerythritol hexaacrylate (DPHA) and having a refractive index of 1.52 and a thickness of 7 μm or more after drying was coated on the PET base material. The coating liquid for high refractive index layer (refractive index 1.76) was applied and completely UV cured to form a medium refractive index layer having a refractive index of 1.76 and a thickness of 70 nm after drying. On the obtained middle refractive index layer, a titanium oxide film (TiOx) having a refractive index of 1.90 and a thickness of 80 nm is formed as a high refractive index layer by sputtering. 47. A silicon oxide film (SiOx) having a thickness of 90 nm was formed as a low refractive index layer. Further, a fluorine-based antifouling material was applied thereon, an antifouling layer was formed, and an antireflection film was obtained.
[0192]
(2) Evaluation
The antireflection film obtained in Example 10 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflection film obtained in Example 10 had a reflectance in the visible light region of 450 nm to 650 nm of 0.3 to 1.2%. The antireflection film had a pencil hardness of 3H.
[0193]
(Example 11)
In this example, an antireflection film F10 having the structure shown in FIG. 13 was prepared. The antireflection film F10 has a transparent conductive layer 31, an anisotropic conductive clear hard coat layer 25, a medium refractive index layer 26, a high refractive index layer 27, a low refractive index layer 28, and an antifouling layer 34 on the base film 24. The intermediate refractive index layer was formed using the coating composition according to the present invention.
[0194]
(1) Coating and curing
Clear hard with a refractive index of 1.52 by adding 0.005 part of gold-nickel resin beads (Bright GNR4.6-EH, manufactured by Nippon Chemical Industry Co., Ltd.) as a conductive material to dipentaerythritol hexaacrylate (DPHA) A coating solution for the coating layer was prepared.
[0195]
Next, the same ATO-containing transparent conductive ink as in Example 5 (Sumitomo Osaka Cement, Sumise Fine ASP-BJ-l) was applied onto the PET substrate, UV-cured to the extent that no surface tack remained, and dried. A transparent conductive layer having a thickness of 2 μm was formed. On the obtained transparent conductive layer, a clear hard coat layer coating solution to which the above-mentioned conductive material is added is applied, UV cured, a refractive index of 1.52, and an anisotropic conductivity of 7 μm or more in thickness after drying. The high-refractive-index layer coating liquid (refractive index 1.76) obtained in Example 3 was further coated thereon and UV-cured completely. 1.76, after drying, a medium refractive index layer having a thickness of 70 nm was formed. On the obtained middle refractive index layer, a titanium oxide film (TiOx) having a refractive index of 1.90 and a thickness of 80 nm is formed as a high refractive index layer by sputtering. 47. A silicon oxide film (SiOx) having a thickness of 90 nm was formed as a low refractive index layer. Further, a fluorine-based antifouling material was applied thereon, an antifouling layer was formed, and an antireflection film was obtained.
[0196]
(2) Evaluation
The antireflection film obtained in Example 11 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. As in the case of Example 10, the antireflection film obtained in Example 11 had a reflectance in the visible light region of 450 nm to 650 nm of 0.3 to 1.2%. The pencil hardness was 3H.
[0197]
(Example 12)
In this example, an antireflection film F11 having the configuration shown in FIG. 14 was prepared. The antireflection film F11 has a configuration in which a transparent conductive layer 31, a high refractive index mat hard coat layer 33 containing a filler 30 and a low refractive index layer 28 are sequentially laminated on a base film 24, and a high refractive index thereof. A mat hard coat layer was formed using the coating composition according to the present invention.
[0198]
(1) Preparation of coating solution for transparent conductive layer
The following components excluding the diluting solvent were mixed and stirred sufficiently, and then the diluting solvent was further mixed to prepare a transparent conductive layer coating liquid (solid content of about 10% by weight).
<Coating liquid for transparent conductive layer>
・ ATO: 29.4 parts
OH group-containing binder 1 (urethane acrylate): 14.2 parts
OH group-containing binder 2 (pentaerythritol triacrylate (PETA) / hexanediol diacrylate (HDDA) = 7/3): 27.8 parts
Solvent (methyl cellosolve): 55.0 parts
Initiator (Irgacure 184): 3 parts
Diluting solvent (cyclohexanone / toluene = 3/7): 584 parts
(2) Preparation of coating liquid for anisotropic conductive high refractive index mat hard coat layer
A clear hard coat layer coating solution having a refractive index of 1.70 was prepared in the same manner as in Example 6. The anisotropic conductive high refractive index mat having a refractive index of 1.66 having the following composition using the resulting coating solution. A coating solution for a hard coat layer was obtained. As the conductive fine particles, gold-nickel resin beads (Bright GNR4.6-EH, manufactured by Nippon Chemical Industry Co., Ltd.) having an average particle diameter of 5 μm were used. The dispersibility of the rutile titanium oxide ultrafine particles was stable even when a mat material (acrylic beads) or a binder was added, and the haze difference from the base film was 0.01.
<Coating liquid for anisotropic conductive high refractive index mat hard coat layer>
-Coating liquid for clear hard coat layer with a refractive index of 1.70 (solid content 50 wt%): 4 parts
Acrylic paste (pentaerythritol triacrylate / bead = 6/4, particle size 3.5 μm): 0.5 part
Cellulose acetate polypropionate (CAP) (ethyl acetate solution having a solid content of 10% by weight): 2.3 parts
Initiator (Irgacure 651): 0.06 part
Conductive fine particles (Bright GNR 4.6-EH, manufactured by Nippon Chemical Industry Co., Ltd.): 0.0045 parts (0.1% by weight of all binder components)
Solvent (toluene): 2.4 parts
(2) Coating and curing
On the TAC substrate, the transparent conductive layer coating liquid (solid content: about 10%) is applied, UV cured to the extent that no surface tack remains, and a transparent conductive layer with a thickness of 1.2 μm is formed after drying. did. On this conductive layer, the anisotropic conductive high refractive index mat hard coat layer coating liquid having a refractive index of 1.66 is further coated and dried, and UV-cured to the extent that no surface tack remains. Having a refractive index of 1.66, a thickness after curing of 3 μm, and a surface resistance of 2 × 10⁷An anisotropic conductive high refractive index mat hard coat layer of Ω / □ was formed. On the obtained anisotropic conductive high refractive index mat hard coat layer, a low refractive index layer having a refractive index of 1.42 composed of a silicon-containing vinylidene fluoride copolymer and a thickness of 90 nm after drying was applied. The film was completely cured with an antireflection film. In the case of using a PET base material, an antireflection film could be similarly produced.
[0199]
(3) Evaluation
The antireflection film obtained in Example 12 was tested in the same manner as in Example 2. The layer structure and test results are shown in Tables 3 and 4, respectively. The antireflective film obtained in Example 12 had a reflectance of 0.8% at a wavelength of 550 nm at which humans are most likely to feel glare. Moreover, this antireflection film had a pencil hardness of 2H.
[0200]
(Comparative Example 4)
As rutile titanium oxide, Al₂O_Three100 parts of rutile type titanium oxide coated with stearic acid and having a primary particle size of about 0.03 μm was prepared. As an ionizing radiation curable binder component, 20 parts of pentaerythritol triacrylate (PET30, Nippon Kayaku Co., Ltd.) was prepared. No dispersant was used.
[0201]
These materials were mixed with methyl isobutyl ketone to a solid content concentration of 15% by weight, zirconia balls were added as a dispersion medium to the mixture, and the mixture was stirred for 7 hours or more in a paint shaker.
[0202]
After adding 3 parts of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184) as a photoinitiator to the obtained dispersion, methyl isobutyl ketone was added to dilute the solid content concentration to 3% by weight, A coating solution for a high refractive index layer having a refractive index of 1.90 was obtained.
[0203]
When the obtained coating liquid was applied, the coating film was cloudy. Moreover, when the coating liquid was allowed to stand for several hours, a sediment was observed.
[0204]
(Comparative Example 5)
As rutile titanium oxide, Al₂O_Three100 parts of rutile-type titanium oxide having a primary particle size of about 0.03 μm, which is not coated with an anionic compound, was prepared. As an ionizing radiation curable binder component, 20 parts of pentaerythritol triacrylate (PET30, Nippon Kayaku Co., Ltd.) was prepared. As a dispersant, 20 parts of a dispersant (Phosmer M) having an ethylene oxide chain and an anionic polar group was prepared.
[0205]
These materials were mixed with methyl isobutyl ketone to a solid content concentration of 15% by weight, and zirconia balls were added as a dispersion medium thereto, followed by stirring in a paint shaker for 7 hours or more.
[0206]
After adding 3 parts of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184) as a photoinitiator to the obtained dispersion, methyl isobutyl ketone was added to dilute the solid content concentration to 3% by weight, A coating solution was obtained.
[0207]
When the obtained coating liquid was applied, the coating film was cloudy. Moreover, when the coating liquid was allowed to stand for several hours, a sediment was observed.
[0208]
(Comparative Example 6)
Commercially available zirconia (ZrO₂) Pentaerythritol triacrylate (PET30, Nippon Chemical Co., Ltd.) as an ionizing radiation-curable binder component in a dispersion (solid content 15% by weight, solvent: toluene 25.5 / acetylacetone 42 / other 17.5, manufactured by Sumitomo Osaka Cement) (Manufactured by Yakuhin Co., Ltd.) was added to prepare a coating solution for a high refractive index layer having a refractive index of 1.76. An antireflection film was prepared.
[0209]
The antireflection film having the same layer structure as in Example 3 had a pencil hardness of F and no adhesion to the clear hard coat layer.
[0210]
The antireflection film having the same layer structure as in Example 10 had a pencil hardness of H and no adhesion to the clear hard coat layer.
[0211]
Further, since the solvent system is complicated, spots were easily generated during drying. Moreover, the above-mentioned zirconia (ZrO) having a solid content of 15% using a ketone solvent suitable for coating₂) When the dispersion was diluted to 3% solid content, there was a problem that the dispersibility deteriorated because of the poor compatibility with the dispersant.
[0212]
[Table 3]

[0213]
[Table 4]

[0214]
【The invention's effect】
As described above, the coating composition used in the present invention can sufficiently disperse ultrafine particles of titanium oxide having a high refractive index and has excellent dispersion stability. High refractive index and transparency required for optical members such as anti-reflective coatings by applying the coating composition to the surface to be coated and curing it by irradiation with ionizing radiation. Can be obtained, and sufficient coating strength and adhesion to an adjacent layer can be obtained.
[0215]
Further, in the present invention, the photocatalytic activity of titanium oxide is reduced or eliminated by performing a surface treatment with an inorganic compound, which causes a decrease in the strength of the coating film due to deterioration of the binder component and a decrease in antireflection performance. Yellowing phenomenon is unlikely to occur.
[0216]
In addition, the coating composition is also excellent in coating suitability and can easily form a uniform large-area thin film.
[0217]
Therefore, according to the present invention, there is provided a high-quality antireflection film formed by laminating a light transmission layer excellent in various properties such as transparency, film strength, adhesion to adjacent layers, and film thickness uniformity. . Further, according to the present invention, it is possible to manufacture such a high-quality antireflection film by wet coating.
[0218]
In particular, the coating composition described above is suitable for forming a medium refractive index layer, a high refractive index layer, or a high refractive index hard coat layer in view of a refractive index range that can be adjusted by changing the blending amount of titanium oxide. Yes.
[0219]
Furthermore, according to this invention, while using ionizing radiation sclerosis | hardenability as a binder component of a coating composition and using a binder component which has a hydrogen bond formation group, the hardened layer excellent in the adhesiveness with respect to an adjacent layer can be formed. In particular, it is useful in that very high adhesion can be obtained even for a film formed by a dry coating method such as a silicon oxide vapor deposition film or a titanium oxide sputtering film.
[0220]
Furthermore, the coating composition used in the present invention is very excellent in coating suitability, and does not cause coating spots even on a hard coat layer having a clear surface where interference color spots are very easy to see. An antireflection film can be formed, and a film free from coating spots can also be formed on a mat hard coat layer having a fine uneven surface.
[Brief description of the drawings]
1 is an example of a liquid crystal display device in which a display surface is coated with a multilayer antireflection film containing a coating film according to the present invention, and is a diagram schematically showing a cross section thereof.
FIG. 2 is an example of an alignment plate provided with a multilayer antireflection film including a coating film according to the present invention, and is a diagram schematically showing a cross section thereof.
FIG. 3 is an example of an antireflection film including a coating film according to the present invention, and is a diagram schematically showing a cross section thereof.
4 is a view schematically showing a cross section of an antireflection film prepared in Example 2. FIG.
5 is a view schematically showing a cross section of an antireflection film prepared in Example 3. FIG.
6 is a view schematically showing a cross section of an antireflection film prepared in Example 4. FIG.
7 is a view schematically showing a cross section of an antireflection film prepared in Example 5. FIG.
8 is a view schematically showing a cross section of an antireflection film prepared in Example 6. FIG.
9 is a view schematically showing a cross section of an antireflection film prepared in Example 7. FIG.
10 is a view schematically showing a cross section of an antireflection film prepared in Example 8. FIG.
11 is a diagram schematically showing a cross section of an antireflection film prepared in Example 9. FIG.
12 is a view schematically showing a cross section of the antireflection film prepared in Example 10. FIG.
13 is a view schematically showing a cross section of an antireflection film prepared in Example 11. FIG.
14 is a view schematically showing a cross section of an antireflection film prepared in Example 12. FIG.
[Explanation of symbols]
101 ... Liquid crystal display device
102: Antireflection film
1 ... Glass substrate on display side
2. Pixel part
3 ... Black matrix layer
4. Color filter
5, 7 ... Transparent electrode layer
6 ... Back side glass substrate
8 ... Sealing material
9 ... Alignment film
10 ... Polarizing film
11 ... Backlight unit
12 ... Polarizing element
13, 14 ... Protective film
15 ... Adhesive layer
16 ... Hard coat layer
17 ... Multilayer antireflection film
18 ... Medium refractive index layer
19 ... High refractive index layer
20 ... Low refractive index layer
21 ... Base film
22 ... High refractive index layer
23 ... Low refractive index layer
24 ... Base film
25 ... Clear hard coat layer
26: Medium refractive index layer
27 ... High refractive index layer
28 ... Low refractive index layer
29 ... Matte hard coat layer
30 ... Filler
31 ... Transparent conductive layer
32 ... High refractive index clear hard coat layer
33 ... High refractive index mat hard coat layer
34 ... Antifouling layer

Claims (21)

It has a single layer structure composed of one light transmitting layer having light transmittance, or a multilayer structure in which two or more light transmitting layers having light transmittance and different refractive indexes are laminated.
At least one of the light transmission layers is coated with an inorganic compound that reduces or eliminates the photocatalytic activity and an organic compound and / or an organic metal compound having an anionic polar group, and is in the range of 0.01 to 0.1 μm. A rutile type titanium oxide having a particle size, and a dispersant having a molecular structure in which a side chain comprising an anionic polar group or a side chain having an anionic polar group is bonded to a main chain having an ethylene oxide chain skeleton Is a cured layer that is uniformly mixed in a cured binder. The cured layer is an essential component,
(1) A rutile type having a primary particle diameter in the range of 0.01 to 0.1 μm, which is coated with an inorganic compound that reduces or eliminates photocatalytic activity and an organic compound and / or organometallic compound having an anionic polar group. Titanium oxide,
(2) ionizing radiation curable binder component,
(3) A dispersant having a molecular structure in which a side chain comprising an anionic polar group or a side chain having an anionic polar group is bonded to a main chain having an ethylene oxide chain skeleton , and
(4) organic solvent,
The antireflection film according to claim 1, wherein the antireflection film is a coating film obtained by coating a coating composition containing a coating on a surface to be coated with a cured layer and curing the coating composition. The inorganic compound includes alumina, silica, zinc oxide, zirconium oxide, tin oxide, antimony-doped tin oxide (ATO), tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), and aluminum. The antireflection film according to claim 1, wherein the antireflection film is selected from the group consisting of doped zinc oxide (AZO) and fluorine-doped tin oxide (FTO). The organic compound and / or organometallic compound having the anionic polar group is selected from the group consisting of organic carboxylic acids, silane coupling agents, and titanate coupling agents . The antireflection film described in 1. The binder, characterized in that it is a cured product of the binder component having an anionic polar group, the anti-reflection film according to any one of claims 1 to 4. The light transmission layer comprises at least a high refractive index layer and a low refractive index layer, or comprises at least a high refractive index layer, a low refractive index layer and one or more medium refractive index layers,
The high refractive index layer, the middle refractive index layer, and the low refractive index layer are laminated so that the refractive index is alternately switched and the low refractive index layer is positioned closest to the viewing surface side.
At least one is characterized in that it is formed by the hardening layer, antireflection film according to claim 1 to 5 of the high refractive index layer and the medium refractive index layer. At least one of the high-refractive index layer and the medium-refractive index layer contains a binder made of a cured product in which a hydrogen bond-forming group is left, and the high-refractive index layer or medium-refractive index formed by the cured layer The antireflection according to claim 6 , wherein a high refractive index layer, a medium refractive index layer or a low refractive index layer containing a hydrogen bond-forming group is formed by a dry coating method adjacent to the layer. film. The antireflection film according to claim 7 , wherein a sputtering film containing titanium oxide is formed as a high refractive index layer or a medium refractive index layer containing a hydrogen bond forming group. The antireflection film according to claim 7 or 8 , wherein a vapor-deposited film containing silicon oxide is formed as the low refractive index layer containing a hydrogen bond forming group. The light transmission layer includes at least a high refractive index hard coat layer and a low refractive index layer having a refractive index capable of functioning as a high to medium refractive index layer, or a refractive index capable of functioning as a high to medium refractive index layer. A high refractive index layer and / or one or more medium refractive index layers, in addition to a high refractive index hard coat layer and a low refractive index layer ,
The high refractive index hard coat layer, high refractive index layer, medium refractive index layer and low refractive index layer are alternately switched in refractive index, and the high refractive index hard coat layer is closest to the contact surface with the display medium. And is laminated so that the low refractive index layer is located closest to the viewing surface,
Wherein the high refractive index hard coat layer is formed by the hardening layer, antireflection film according to any one of claims 1 to 5. High refractive index hard coat layer formed by the hardened layer has an antiglare fine irregular surface, characterized in that the fine uneven surface is provided by embossing, according to claim 10 Antireflection film. The high refractive index hard coat layer formed by the cured layer has an antiglare fine uneven surface, and the fine uneven surface is provided by dispersing filler inside the high refractive index hard coat layer. The antireflection film according to claim 10 , wherein The difference Δn between the refractive index of the filler and the refractive index of the binder of the high refractive index hard coat layer is 0.01 ≦ Δn ≦ 0.5, and the average particle diameter d of the filler is 0.1 μm ≦ d. The antireflection film according to claim 12 , wherein ≦ 10 μm. The high refractive index hard coat layer formed by the cured layer has a film thickness of 1 to 10 μm, a refractive index of 1.55 to 1.83, and a haze value defined in JIS-K7361-1. The antireflection film according to any one of claims 10 to 13 , wherein the haze value of the base material alone is not changed, or the difference between the haze value of the base material alone is 3% or less. The high refractive index hard coat layer contains a binder composed of a cured product leaving a hydrogen bond forming group, and is adjacent to the high refractive index hard coat layer and contains a hydrogen bond forming group. The antireflective film according to claim 10 , wherein the medium refractive index layer, the low refractive index layer, or the transparent conductive layer is formed by a dry coating method. The antireflection film according to claim 15 , wherein a sputtering film containing titanium oxide is formed as the high refractive index layer or medium refractive index layer containing the hydrogen bond forming group. The antireflection film according to claim 15 , wherein a vapor deposition film containing silicon oxide is formed as the low refractive index layer containing a hydrogen bond forming group. The antireflection film according to any one of claims 1 to 5 is laminated on at least one surface side of a light-transmitting base film so that the antireflection film is positioned closer to the viewing surface than the base film. An antireflection film characterized by comprising: The antireflection film according to any one of claims 6 to 17 is laminated on at least one surface side of a light-transmitting base film so that the low refractive index layer of the antireflection film is positioned on the viewing surface side. An antireflection film characterized by comprising: 6. An image display device, wherein the display surface is covered with the antireflection film according to claim 1 so that the antireflection film is positioned on the viewing surface side. 18. An image display device comprising an antireflection film according to any one of claims 6 to 17 , wherein the display surface is covered so that the low refractive index layer of the antireflection film is positioned on the viewing surface side. .

Images