JP4015471B2 - Photocurable resin composition, fine uneven pattern transfer foil, optical article, stamper, and method for forming fine uneven pattern - Google Patents

Description

【００５６】
（式中、Ｚはウレタン変性アクリル樹脂を改質するための基を表し、好ましくは嵩高い環状構造の基である。Ｒ¹は夫々互いに独立して水素原子又はメチル基を表し、Ｒ²はＣ₁〜Ｃ₁₆の炭化水素基を表し、Ｘ及びＹは直鎖状又は分岐鎖状のアルキレン基を表す。ｌ（エル）とｍとｎとｏ（オー）とｐの合計を１００とした場合に、ｌは０〜９０、ｍは０〜８０、ｎは０〜５０、ｏ+ｐは１０〜８０、ｐは０〜４０の整数である。）
上記式１におけるＺは、上記のウレタン変性アクリル樹脂を改質するために導入することができ、例えばフェニル基、ナフチル基等の芳香族環或いはピリジン等の複素芳香族環を有する（メタ）アクリレート、（メタ）アクリロイル変性シリコーンオイル又は樹脂、ビニル変性シリコーンオイル又は樹脂等の重合性二重結合基を有するシリコーンオイル又は樹脂、ラウリル（メタ）アクリレート、ステアリル（メタ）アクリレート等の長鎖アルキル基を有する（メタ）アクリレート、γ−（メタ）アルコシキプロピルトリメトキシシラン等の珪素含有基を有する（メタ）アクリレート、２−（パーフルオロ−７−メチルオクチル）エチルアクリレート、ヘプタデカフロロデシル（メタ）アクリレート等のフッ素含有基を有する（メタ）アクリレート、イソボルニル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート、ジシクロペンテニルオキシエチル（メタ）アクリレート、アダマンチル（メタ）アクリレート等のかさ高い構造を有する（メタ）アクリレート、アクリロイルモルフォリン、ビニルピロリドン、ビニルカプロラクトン等の環状親水性基を有するビニルモノマーを用いて導入することができる。Ｚとしては、上記のうちから選ばれた１種又は２種以上を導入することができる。
【００５７】
上記式１のウレタン変性アクリル系樹脂の好ましい１例としては、メチルメタクリレート０〜９０モルと、嵩高い基を有するビニルモノマー０〜８０モルとメタクリル酸０〜５０モルと２−ヒドロキシエチルメタクリレート１０〜８０モルとを共重合して得られるアクリル共重合体であって、該共重合体中に存在している水酸基にメタクリロイルオキシエチルイソシアネート（２−イソシアネートエチルメタクリレート）を反応させて得られる樹脂を例示することができる。
【００５８】
上記メタクリロイルオキシエチルイソシアネートは共重合体中に存在している全ての水酸基に反応している必要はなく、共重合体中の２−ヒドロキシエチルメタクリレート単位の水酸基の少なくとも１０モル％以上、好ましくは５０モル％以上がメタクリロイルオキシエチルイソシアネートと反応していればよい。上記の２−ヒドロキシエチルメタクリレートに代えて又は併用して、Ｎ−メチロール（メタ）アクリルアミド、２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート、４−ヒドロキシブチル（メタ）アクリレート等の水酸基を有するモノマーも使用することができる。
【００５９】
上記のウレタン変性アクリル系樹脂は、前記共重合体を溶解可能な溶剤、例えば、トルエン、ケトン、セロソルブアセテート、ジメチルスルフォキサイド等の溶媒に溶解させ、この溶液を撹拌しながら、メタクリロイルオキシエチルイソシアネートを滴下及び反応させることにより、イソシアネート基がアクリル系樹脂の水酸基と反応してウレタン結合を生じ、該ウレタン結合を介して樹脂中にメタクリロイル基を導入することができる。この際使用するメタクリロイルオキシエチルイソシアネートの使用量は、アクリル系樹脂の水酸基とイソシアネート基との比率で水酸基１モル当たりイソシアネート基０．１〜５モル、好ましくは０．５〜３モルの範囲になる量である。尚、上記樹脂中の水酸基よりも当量以上のメタクリロイルオキシエチルイソシアネートを使用する場合には、該メタクリロイルオキシエチルイソシアネートは樹脂中のカルボキシル基とも反応して−ＣＯＮＨ−ＣＨ₂ＣＨ₂−の連結を生じることもあり得る。
【００６０】
以上の例は、前記構造式において、全てのＲ¹及びＲ²がメチル基であり、Ｘ及びＹがエチレン基である場合であるが、本発明は、これらに限定されず、６個のＲ¹は夫々独立して水素原子又はメチル基であってもよく、更にＲ²の具体例としては、例えば、メチル基、エチル基、ｎ−又はｉｓｏ−プロピル基、ｎ−、ｉｓｏ−又はｔｅｒｔ−ブチル基、置換又は未置換のフェニル基、置換又は未置換のベンジル基等が挙げられ、Ｘ及びＹの具体例としては、エチレン基、プロピレン基、ジエチレン基、ジプロピレン基等が挙げられる。上記の嵩高い環状構造の基Ｚを有するモノマーとしては、例えば、イソボルニル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート、ジシクロペンテニルオキシエチル（メタ）アクリレート、アダマンチル（メタ）アクリレート等の如く、５員環、６員環或いはそれ以上の嵩高い基を有するモノマーであることが好ましい。
【００６１】
ウレタンアクリレートは、分子中にウレタン結合と、光重合性を有する（メタ）アクリロイル基を有するものであれば、いずれも使用できる。ウレタンアクリレートの中では、２個以上のイソシアネート基を有するイソシアネート化合物と、２個以上の水酸基を有する化合物と、１個以上の水酸基及び１個以上の（メタ）アクリロイル基を有する化合物を反応させて得られるウレタンアクリレート、又は、２個以上のイソシアネート基を有するイソシアネート化合物と、２個以上の水酸基及び１個以上の（メタ）アクリロイル基を有する化合物を反応させて得られるウレタンアクリレートが好ましい。
【００６２】
ウレタンアクリレートの合成に用いる２個以上のイソシアネート基を有するイソシアネート化合物としては、テトラメチレンジイソシアネート、ヘキサメチレンジイソシアネート、２，４−トリレンジイソシアネート、２，６−トリレンジイソシアネート、４，４’−ジフェニルメタンジイソシアネート、１，５−ナフタレンジイソシアネート、３，３−ジメチル−４，４−ジフェニレンイソシアネート、イソホロンジイソシアネート、ｍ−キシリレンジイソシアネート、ｐ−キシリレンジイソシアネート、１，３−ビス（イソシアネートメチル）シクロヘキサン、１，３−ビス（α，α−ジメチルイソシアネートメチル）ベンゼン、トリメチルヘキサメチレンジイソシアネート、水素添加キシリレンジイソシアネート等が挙げられる。これらは単独で又は２種以上を混合して使用することができる。
【００６３】
また、下記式２ａ乃至２ｇで表されるイソシアネート化合物を使用することもできる。
【００６４】
【化２】

【００６５】
ウレタンアクリレートの合成に用いる２個以上の水酸基を有する化合物としては、例えば、１，３−ブタンジオール、１，４−ブタンジオール、トリメチロールエタン、トリメチロールプロパン、ジトリメチロールエタン、ジトリメチロールプロパン、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、ジグリセロール、グリセリン、その他、数々のポリシロキサンポリオール、ポリ（オキシアルキレン）ポリオール、ポリエステルポリオール、ポリエーテルポリオール、ポリエーテルポリエステルポリオール、ポリオレフィンポリオール、ポリ（アルキルアクリレート）ポリオール、ポリカーボネートポリオール等が挙げられる。
【００６６】
ウレタンアクリレートの合成に用いる１個以上の水酸基及び１個以上の（メタ）アクリロイル基を有する化合物としては、例えば、トリメチロールプロパントリアクリレート、２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート、４−ヒドロキシシクロヘキシル（メタ）アクリレート、５−ヒドロキシシクロオクチル（メタ）アクリレート、２−ヒドロキシ−３−フェニルオキシプロピル（メタ）アクリレート、ペンタエリスリトールトリアクリレート、ジペンタエリスリトールペンタアクリレート、及び、イソシアヌル酸オキシエチルジ（メタ）アクリレートが挙げられる。
【００６７】
以上説明したウレタンアクリレートは、特開平３−１９８４２号に記載の反応条件で上記の各成分を反応させることにより製造することができる。
【００６８】
別のウレタンアクリレートとしては、特開２００１−３２９０３１号に記載されている、乾燥しただけの未硬化状態でもタックフリーな活性エネルギー線硬化性組成物を例示することができる。このタックフリーな組成物は、融点が４０℃以上のイソシアネート化合物と、（メタ）アクリロイル基を有していて且つイソシアネート基と反応し得る（メタ）アクリル化合物との反応生成物であって、融点が４０℃以上のものを含有する。上記融点が４０℃以上のイソシアネート化合物としては、非芳香族性炭化水素環に結合したイソシアネート基を有する化合物、特にイソホロンジイソシアネートの３量体、イソホロンジイソシアネートとトリメチロールプロパンとの３：１（モル比）の反応生成物が好ましい。上記（メタ）アクリル化合物としては、（メタ）アクリル酸や、ヒドロキシエチル（メタ）アクリレートのような水酸基を有する（メタ）アクリレートが好ましい。
【００６９】
ポリエステルアクリレートは、分子中にエステル結合と、光重合性を有する（メタ）アクリロイル基を有するものであれば、いずれも使用できる。ポリエステルアクリレートの中では、２個以上の水酸基を有する化合物又は環状エステル化合物と多塩基酸とから合成したポリエステル化合物に、さらに（メタ）アクリロイル基を持つ化合物を反応させて得られるポリエステルアクリレートが好ましい。
【００７０】
ポリエステルアクリレートの合成に用いる２個以上の水酸基を有する化合物としては、上記ウレタンアクリレートの合成に用いるものと同じものを用いることができる。
【００７１】
ポリエステルアクリレートの合成に用いる環状エステル化合物としては、例えば、ε−カプロラクトン、δ−バレロラクトン、γ−ブチロラクトン、γ−バレロラクトン等のラクトン化合物、その誘導体、若しくは当該ラクトン化合物とグリシジルメタクリレート等のエポキシ化合物との付加反応生成物を挙げることができる。
【００７２】
ポリエステルアクリレートの合成に用いる多塩基酸としては、例えば、アジピン酸、コハク酸、セバチン酸等の飽和多塩基酸；マレイン酸、フマル酸、イタコン酸、シトラコン酸等の不飽和多塩基酸；フタル酸、イソフタル酸、テレフタル酸、トリメリット酸等の芳香族多塩基酸を挙げることができる。
【００７３】
本発明においては、バインダー樹脂として、光重合性官能基を有するバインダー樹脂（Ａ）を１種単独で、又は２種以上組み合わせて用いることができる。また、本発明においては、本発明の目的を達成し得る限り、光重合性官能基を有しない樹脂を混合しても良い。そのような光重合性官能基を有しない樹脂としては、従来から光学物品を形成するのに用いられている非重合性透明樹脂、例えば、ポリアクリル酸、ポリメタクリル酸、ポリアクリレート、ポリメタクリレート、ポリオレフィン、ポリスチロール、ポリアミド、ポリイミド、ポリビニルクロライド、ポリビニルアルコール、ポリビニルブチラール、ポリカーボネート等を挙げることができる。
【００７４】
本発明においては、光硬化性樹脂層にプレススタンパーを押圧して微細凹凸パターンを賦形し、スタンパ−を取り外した後の、露光工程や蒸着工程等のプロセス途中で、光硬化性樹脂の弾性により微細凹凸パターンが丸みを帯びて型崩れするのを防ぐために、光硬化性樹脂組成物に、希釈溶剤中でコロイド状の形態に分散させることが可能で且つサブミクロンオーダーの無機超微粒子（Ｂ）を配合してクリープ特性と形状保持性を向上させる。
【００７５】
また、光硬化性樹脂組成物に無機超微粒子（Ｂ）を配合することにより当該光硬化性樹脂組成物の離型性も向上し、光硬化性樹脂層に押圧したスタンパ−を取り外すときにスタンパ−のキャビティ内面に樹脂組成物が付着しにくくなり、さらには表面タックが低減するので、基材フィルムに光硬化性樹脂層を形成しプレススタンパーを押圧する前の中間積層体をロール状に巻き取ってもブロッキングを生じないという利点もある。
【００７６】
また、本発明の光硬化性樹脂組成物は、無機超微粒子（Ｂ）を配合することで硬化収縮時の応力が緩和され易くなり、硬化収縮の歪みに起因する種々の問題点を解決することが出来る。例えば、光硬化性樹脂組成物の硬化時に、硬化収縮による樹脂の割れ、カール、しわ等の発生を抑えることができる。或いは、転写箔に含まれる光硬化性樹脂組成物の層を硬化させる場合に、これに隣接する層、例えば、フィルム基材、剥離層、金属蒸着層との収縮率の相違により、箔の部分的な割れ、よれ、しわ等の発生を抑えることができる。
【００７７】
本発明の光硬化性樹脂組成物は、希釈溶剤を用いて塗工作業に用いられる濃度に最初から調製する場合のほか、溶剤を全く含有しないか或いは希釈溶剤を少量しか含有しない高濃度の状態で保存し、使用直前に希釈溶剤を加えて塗工作業に用いられる濃度に調節する場合があるが、いずれの場合であっても無機超微粒子（Ｂ）は、最終的に希釈溶剤中でコロイド状の形態となって均一に分散させることが可能なものであることが必要である。
【００７８】
無機超微粒子の具体例としては、ＳｉＯ₂、ＴｉＯ₂、ＺｒＯ₂、ＳｎＯ₂、Ａｌ₂Ｏ₃等の金属酸化物超微粒子を挙げることができ、これらの中から上記したようにコロイド状分散可能で且つサブミクロンオーダーの粒子サイズを有するものを選択して用いるのが好ましく、特に、コロイダルシリカ（ＳｉＯ₂）微粒子を用いるのが好ましい。
【００７９】
金属酸化物超微粒子の一部が金属水酸化物になっており、水が吸着して水和した構造をとっていると、希釈溶剤中でコロイド状の形態に分散させやすいので好ましい。また、希釈溶剤として有機溶剤を用いる場合には、無機超微粒子の表面を疎水性処理することにより、コロイド状に分散させやすくなる。無機超微粒子が金属酸化物の場合は、例えば、有機アミンや有機カルボン酸などの有機低分子成分で表面処理することにより疎水性を付与することができる。
【００８０】
また、無機超微粒子（Ｂ）は、塗膜に充分な透明性を確保するために、いわゆる超微粒子サイズのものを用いる。ここで「超微粒子」とはサブミクロンオーダーの粒子のことであり、一般的に「微粒子」と呼ばれている数μｍから数１００μｍの粒子径を有する粒子よりも粒子径の小さいものを意味している。本発明において用いられる無機超微粒子（Ｂ）の具体的なサイズは、本発明の光硬化性樹脂組成物が適用される光学物品の用途及びグレードによっても相違するが、一般的な球状の場合には一次粒子径が１ｎｍ〜３００ｎｍの範囲のものを用いるのが好ましい。一次粒子径が１ｎｍ未満では、樹脂組成物のクリープ特性を充分に向上させることが困難になり、一方、一次粒子径が３００ｎｍを超えると、樹脂の透明性が損なわれ光学物品の用途によっては透明性が不充分となる場合がある。
【００８１】
無機超微粒子（Ｂ）は、どのような形状であっても良いが、嵩高い形状を持つ微粒子、すなわち密度が小さくなる形状を持つ微粒子が好ましい。嵩高い無機超微粒子を用いることで、光硬化性樹脂組成物の耐ブロッキング性、クリープ特性及び凹凸パターンの形状保持性が特に向上する。
【００８２】
嵩高い形状としては、例えば細長い形状、特にその伸長が同一平面内に存在する針状やパールネックレス状等の形状を用いることが出来る。パールネックレス状とは、球状粒子を数珠状又は直列に繋いだ形状である。無機超微粒子（Ｂ）が細長い形状の場合には、太さ（径）１〜１００ｎｍ、長さ１０〜５００ｎｍの範囲のものを用いるのが好ましく、太さ１〜２０ｎｍ、長さ４０〜３００ｎｍの範囲が特に好ましい。長さが１０ｎｍ未満では、球状シリカとの差は無く、５００ｎｍを超えると透明性が損なわれるためである。
【００８３】
細長い形状をアスペクト比（太さに対する長さの比）で表す場合、アスペクト比は３以上であることが好ましい。アスペクト比は、顕微鏡により直接測定された太さと長さから算出しても良いし、動的光散乱法により測定された粒子径（Ｄ₁ｎｍ）と窒素ガス吸着法により測定された粒子径（Ｄ₂ｎｍ）の比Ｄ₁／Ｄ₂を算出してアスペクト比としてもよい。
【００８４】
細長い形状の無機超微粒子の好ましい具体例としては、アスペクト比が３以上であって、電子顕微鏡で観察した時に太さ５〜２０ｎｍ、長さ４０〜３００ｎｍである針状シリカ、又は、太さ１０〜８０ｎｍ、長さ５０〜５００ｎｍであるパールネックレス状シリカが挙げられる。形状としては、特に針状シリカが好ましく、球状のものと比べて少ない添加量で充分なクリープ特性、ブロッキング防止性能を発揮する。
【００８５】
無機超微粒子（Ｂ）は、光硬化性樹脂組成物の固形分全量中に０．１〜７０重量％の割合で配合するのが好ましく、特に球状微粒子の場合には１〜５０重量％、細長い形状の微粒子の場合には０．１〜３０重量％の割合で配合するのが特に好ましい。無機超微粒子（Ｂ）の割合が０．１重量％未満では、樹脂組成物のクリープ特性を充分に向上させることが困難になり、一方、無機超微粒子（Ｂ）の割合が７０重量％を超えると、脆質性が顕著になり、露光硬化後に充分な強度や表面硬度が得られにくくなる。なお、光硬化性樹脂組成物の固形分には、溶剤を除く全ての液状成分も含まれる。
【００８６】
本発明の光硬化性樹脂組成物には離型剤を配合してもよい。本発明の光硬化性樹脂組成物に離型剤を配合することにより、光硬化性樹脂層にプレススタンパーを押し付けて取り外す時に樹脂の版取られを防止し、プレススタンパーを長期間連続して使用（反復エンボス性）することができるようになる。
【００８７】
離型剤としては従来公知の離型剤、例えば、ポリエチレンワックス、アミドワックス、テフロンパウダー（テフロンは登録商標）等の固形ワックス、弗素系、リン酸エステル系の界面活性剤、シリコーン等が何れも使用可能である。
【００８８】
特に好ましいのはシリコーン系離型剤であり、水の接触角を９０°以上として型からの離型性を非常に高くすることができる。シリコーン系離型剤には、ポリシロキサン、変性シリコーンオイル、トリメチルシロキシケイ酸を含有するポリシロキサン、シリコーン系アクリル樹脂等がある。
【００８９】
変性シリコーンオイルは、ポリシロキサンの側鎖及び／又は末端を変性したものであり、例えばアミノ変性、エポキシ変性、カルボキシル変性、カルビノール変性、（メタ）アクリル変性、メルカプト変性、フェノール変性、ポリエーテル変性、メチルスチリル変性、アルキル変性、フッ素変性等が挙げられる。一つのポリシロキサン分子に上記したような変性方法の２つ以上を行うこともできる。
【００９０】
シリコーン系アクリル樹脂は、（メタ）アクリロイル変性シリコーンオイルや、ケイ素を含有するモノマーを共重合或いはグラフト化したアクリル樹脂が用いられる。
【００９１】
上記シリコーン系離型剤は１種類のみ或いは２種類以上を組み合わせて添加することができる。
【００９２】
上記離型剤は、光硬化性樹脂組成物の固形分全量中に０．１〜３０重量％の割合で配合するのが好ましい。離型剤の割合が上記範囲未満では、プレススタンパーと光硬化性樹脂層の離型性が不十分となりやすい。一方、離型剤の割合が上記範囲を超えると組成物の塗工時のはじきによる塗膜面の面荒れの問題が生じたり、製品において基材自身及び近接する層、例えば、蒸着層の密着性を阻害したり、転写時に皮膜破壊等（膜強度が弱くなりすぎる）を引き起こす等の点で好ましくない。
【００９３】
本発明の光硬化性樹脂組成物には、組成物の粘度を低下させたり、柔軟性を付与したり、架橋密度を高めるために単官能または多官能のモノマー又はオリゴマーを配合してもよい。
【００９４】
単官能モノマーとしては、例えば、テトラヒドロフルフリル（メタ）アクリレート、ヒドロキシエチル（メタ）アクリレート、ビニルピロリドン、（メタ）アクリロイルオキシエチルサクシネート、（メタ）アクリロイルオキシエチルフタレート、イソボルニル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート等が挙げられる。
【００９５】
多官能のモノマー又はオリゴマーとしては、例えば、２官能のモノマー、オリゴマーとしてはポリエチレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、１，６−ヘキサンジオールジ（メタ）アクリレート等、３官能のモノマー、オリゴマー、ポリマーとしてはトリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、脂肪族トリ（メタ）アクリレート等、４官能のモノマー、オリゴマーとしてはペンタエリスリトールテトラ（メタ）アクリレート、ジトリメチロールプロパンテトラ（メタ）アクリレート、脂肪族テトラ（メタ）アクリレート等が挙げられ、５官能以上のモノマー、オリゴマーとしてはジペンタエリスリトールペンタ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート等の他、ポリエステル骨格、ウレタン骨格、フォスファゼン骨格を有する（メタ）アクリレート等が挙げられる。
【００９６】
単官能、多官能のモノマー又はオリゴマーとしては、上記の（メタ）アクリレート類のほか、スチレン、ビニルトルエン、クロルスチレン、ブロモスチレン、ジビニルベンゼン、１−ビニルナフタレン、２−ビニルナフタレン、Ｎ−ビニルピロリドン等のビニル化合物、ジエチレングリコールビスアリルカーボネート、トリメチロールプロパンジアリル、ジアリルフタレート、ジメタクリルフタレート、ジアリルイソフタレート等のアリル化合物を用いることもできる。
【００９７】
モノマー又はオリゴマーは、光硬化性樹脂組成物の固形分全量中に５〜５０重量％の割合で配合するのが好ましい。モノマー或いはオリゴマーの割合が上記範囲未満では、得られる硬化樹脂層の強度、耐熱性、耐擦傷性、耐水性、耐薬品性、基材に対する密着性が十分とはいえず、一方、モノマー或いはオリゴマーの使用量が上記範囲を超えると表面のタックが高くなり、ブロッキングを引き起こしたり、ホログラム等の複製時に版（プレススタンパー）に材料が一部残る（版取られ）ことにより反復エンボス性が低下する等の点で好ましくない。
【００９８】
本発明の光硬化性樹脂組成物には、微細凹凸パターンを有する表面構造の耐熱性、強度、或いは、金属蒸着層との密着性を高めるために、有機金属カップリング剤を配合してもよい。有機金属カップリング剤としては、例えば、シランカップリング剤、チタンカップリング剤、ジルコニウムカップリング剤、アルミニウムカップリング剤等の各種カップリング剤を使用できる。
【００９９】
シランカップリング剤としては、例えば、γ−（２−アミノエチル）アミノプロピルトリメトキシシラン、γ−（２−アミノエチル）アミノプロピルメチルジメトキシシラン、β−（３，４−エポキシシクロヘキシル）エチルトリメトキシシラン、γ−アミノプロピルトリエトキシシラン、γ−メタクリロキシプロピルトリメトキシシラン、Ｎ−β−（Ｎ−ビニルベンジルアミノエチル−γ−アミノプロピルトリメトキシシラン・塩酸塩、γ−グリシドキシプロピルトリメトキシシラン、アミノシラン、γ−メルカプトプロピルトリメトキシシラン、メチルトリメトキシシラン、メチルトリエトキシシラン、ビニルトリアセトキシシラン、γ−クロロプロピルトリメトキシシラン、ヘキサメチルジシラザン、γ−アニリノプロピルトリメトキシシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン、ビニルトリス（β−メトキシエトキシ）シラン、オクタデシルジメチル［３−（トリメトキシシリル）プロピル］アンモニウムクロライド、γ−クロロプロピルメチルジメトキシシラン、γ−メルカプトプロピルメチルジメトキシシラン、メチルトリクロロシラン、ジメチルジクロロシラン、トリメチルクロロシラン等が挙げられる。
【０１００】
チタンカップリング剤としては、例えば、イソプロピルトリイソステアロイルチタネート、イソプロピルトリドデシルベンゼンスルホニルチタネート、イソプロピルトリス（ジオクチルパイロホスフェート）チタネート、テトライソプロピルビス（ジオクチルホスファイト）チタネート、テトラオクチルビス（ジトリデシルホスファイト）チタネート、テトラ（２，２−ジアリルオキシメチル）ビス（ジトリデシル）ホスファイトチタネート、ビス（ジオクチルパイロホスフェート）オキシアセテートチタネート、ビス（ジオクチルパイロホスフェート）エチレンチタネート、イソプロピルトリオクタノイルチタネート、イソプロピルジメタクリルイソステアロイルチタネート、イソプロピルイソステアロイルジアクリルチタネート、イソプロピルトリ（ジオクチルホスフェート）チタネート、イソプロピルトリクミルフェニルチタネート、イソプロピルトリ（Ｎ−アミノエチル・アミノエチル）チタネート、ジクミルフェニルオキシアセテートチタネート、ジイソステアロイルエチレンチタネート等が挙げられる。
【０１０１】
ジルコニウムカップリング剤としては、例えば、テトラ−ｎ−プロポキシジルコニウム、テトラ−ブトキシジルコニウム、ジルコニウムテトラアセチルアセトネート、ジルコニウムジブトキシビス（アセチルアセトネート）、ジルコニウムトリブトキシエチルアセトアセテート、ジルコニウムブトキシアセチルアセトネートビス（エチルアセトアセテート）等が挙げられる。
【０１０２】
アルミニウムカップリング剤としては、例えば、アルミニウムイソプロピレート、モノｓｅｃ−ブトキシアルミニウムジイソプロピレート、アルミニウムｓｅｃ−ブチレート、アルミニウムエチレート、エチルアセトアセテエートアルミニウムジイソプロピレート、アルミニウムトリス（エチルアセトアセテート）、アルキルアセトアセテートアルミニウムジイソプロピレート、アルミニウムモノアセチルアセトネートビス（エチルアセトアセテート）、アルミニウムトリス（アセチルアセトアセテート）等を挙げることができる。
【０１０３】
上記有機金属カップリング剤は、光硬化性樹脂組成物の固形分全量中に０．１〜１５重量％の割合で配合するのが好ましい。有機金属カップリング剤の割合が上記範囲未満では、耐熱性、強度、蒸着層との密着性の付与効果が不充分である。一方、有機金属カップリング剤の割合が上記範囲を超えると、組成物の安定性、成膜性が損なわれるおそれがある。
【０１０４】
本発明の光硬化性樹脂組成物には、必要に応じて、使用する光源の波長に対して活性を有する光重合開始剤が配合される。光重合開始剤は、バインダーやモノマーの反応形式の違い（例えばラジカル重合やカチオン重合など）に応じて適切な活性種を発生させるものを用いる。
【０１０５】
光ラジカル重合開始剤としては、例えば、ベンゾイン、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインイソプロピルエーテル、α−メチルベンゾイン、α−フェニルベンゾイン等のベンゾイン系化合物；アントラキノン、メチルアントラキノン等のアントラキノン系化合物；ベンジルジアセチルアセトフェノン、ベンゾフェノン等のフェニルケトン系化合物；ジフェニルジスルフィド、テトラメチルチウラムスルフィド等のスルフィド系化合物；α−クロルメチルナフタレン、；アントラセン；及びヘキサクロロブタジエン、ペンタクロロブタジエン等のハロゲン化炭化水素等が挙げられる。
【０１０６】
光カチオン開始剤としては、例えば、芳香族ジアゾニウム塩、芳香族ヨードニウム塩、芳香族スルホニウム塩、芳香族ホスホニウム塩、混合配位子金属塩等が挙げられる。
【０１０７】
光アニオン重合開始剤としては、例えば、１,１０‐ジアミノデカンや４,４’‐トリメチレンジピペリジン、カルバメート類及びその誘導体、コバルト‐アミン錯体類、アミノオキシイミノ類、アンモニウムボレート類等を例示することができる。
【０１０８】
上記光重合開始剤は、光硬化性樹脂組成物の固形分全量に対して０．５〜１０重量％の割合で配合するのが好ましい。光重合開始剤は１種のみを単独で用いてもよいし、２種以上を組み合わせて用いてもよい。
【０１０９】
本発明の光硬化性樹脂組成物には、貯蔵安定性を向上させるために、重合禁止剤を配合してもよい。重合禁止剤としては、例えば、ハイドロキノン、ｔ−ブチルハイドロキノン、カテコール、ハイドロキノンモノメチルエーテル等のフェノール類；ベンゾキノン、ジフェニルベンゾキノン等のキノン類；フェノチアジン類；銅類等を用いることができる。重合禁止剤は、光硬化性樹脂組成物の固形分全量に対して０．１〜１０重量％の割合で配合するのが好ましい。
【０１１０】
本発明に係る光硬化性樹脂組成物は、通常、希釈溶剤（主溶剤）を用いて塗布液の状態に調製し、微細凹凸パターンの形成に用いる。上記したような各材料を、アセトン、メチルエチルケトン、メチルイソブチルケトン、シクロヘキサノン、ベンゼン、トルエン、キシレン、クロルベンゼン、テトラヒドロフラン、メチルセロソルブ、エチルセロソルブ、メチルセロソルブアセテート、エチルセロソルブアセテート、酢酸エチル、１，４−ジオキサン、１，２−ジクロロエタン、ジクロルメタン、クロロホルム、メタノール、エタノール、イソプロパノール等、またはそれらの混合溶剤に溶解、分散することにより、本発明に係る光硬化性樹脂組成物としての塗布液を調製することができる。塗布液は、通常、固形分濃度が１０〜５０重量％程度となるように調節される。
【０１１１】
（微細凹凸パターン形成方法）
本発明に係る光硬化性樹脂組成物を基材フィルム等の支持体の表面に塗布し、必要に応じて乾燥させて微細凹凸パターン形成材料の層（微細凹凸パターン形成層）を形成して凹凸パターン受容体を作製し、当該凹凸パターン受容体の微細凹凸パターン形成層表面にスタンパーを圧接してエンボス加工を行い、微細凹凸パターン形成層を露光又は加熱等の適切な方法で反応硬化させることにより、光学的機能を有する微細凹凸パターンを形成することができ、光学物品やスタンパーとして利用できる。
【０１１２】
支持体に微細凹凸パターン形成層を塗工する前後に、或いは、微細凹凸パターン形成層に微細凹凸パターンを形成する前後に、必要に応じてアンカー層、剥離層、金属薄膜層、オーバーコート層、感圧又は感熱接着剤層等の他の層を形成してもよい。
【０１１３】
微細凹凸パターン形成層は、スタンパーを圧接した状態で硬化させてもよいが、スタンパーを取り外した後で露光、加熱することも可能である。後者の方法は、微細凹凸パターン形成層を硬化工程に移す前にスタンパーを取り外し、取り外したスタンパーはエンボス工程で連続使用できるので連続生産性に優れている。
【０１１４】
また、本発明では、上記微細凹凸パターン形成材料が成膜性及び耐ブロッキング性に優れていることを利用し、基材フィルム上に微細凹凸パターン形成層を形成した中間積層体をロール状に巻き取って一時的に貯蔵し、別の場所へ運搬して巻き戻し、スタンピング及び硬化を行うことも可能である。
【０１１５】
さらにスタンピング及び硬化を行った中間積層体をロール状に巻き取って一時的に貯蔵し、別の場所へ運搬し巻き戻し、必要に応じて追加の光又は熱硬化工程を行って充分に硬化させたり、或いは、必要に応じて微細凹凸パターンの上に金属薄膜、オーバーコート層、感圧又は感熱接着剤層等を形成することが可能である。
【０１１６】
本発明の光硬化性樹脂組成物の硬化に用いる光としては、高エネルギー電離放射線及び紫外線が挙げられる。高エネルギー電離放射線源としては、例えば、コッククロフト型加速器、ハンデグラーフ型加速器、リニヤーアクセレーター、ベータトロン、サイクロトロン等の加速器によって加速された電子線が工業的に最も便利且つ経済的に使用されるが、その他に放射性同位元素や原子炉等から放射されるγ線、Ｘ線、α線、中性子線、陽子線等の放射線も使用できる。紫外線源としては、例えば、紫外線螢光灯、低圧水銀灯、高圧水銀灯、超高圧水銀灯、キセノン灯、炭素アーク灯、太陽灯等が挙げられる。
【０１１７】
本発明の光硬化性樹脂組成物を用いる微小凹凸パターン形成方法を、レリーフホログラムを例にとって具体的に説明する。先ず、光硬化性樹脂組成物を、金属板、紙、ポリエチレンテレフタレート等の基材に塗布又は含浸し、次いで組成物中に含まれている有機溶剤が飛散する温度、例えば、ｌ００〜１６５℃に設定した加熱炉内に０．１〜１分間程度導いて乾燥させて光硬化性樹脂層を基材上に形成する。そして、この光硬化性樹脂層に、例えば、プレススタンパーを用いて所望のホログラムレリーフのパターニング（エンボス加工）行なう。
【０１１８】
ホログラムパターンのエンボス加工は、例えば、レーザー光を用いて作った母型から引き続き作成したプレススタンパーを周面に装着した金属ロ−ルとペーパーロールよりなる１対のエンボスローラーを使用して通常の方法で、例えば、５０〜１５０℃、１０〜５０ｋｇ／ｃｍ²の圧力で行う。なお、複製装置のエンボスローラーとしては、樹脂製版によりマスターホログラムから複製ホログラムを作成し、これをシリンダー上に貼り付けたものも使用できる。
【０１１９】
エンボス加工は片面エンボスで十分であるが、両面エンボスでもよい。エンボスに当たっては、エンボスロールの温度設定が重要であり、エンボス形状を再現する観点からは比較的高温で、比較的高い圧力でエンボスするのが好ましいが、エンボス版への付着を防止するためには比較的低い圧力でエンボスするのが好ましく、全く逆の関係となる。また、有効に作用する熱容量から考えた場合は、複製するフイルムの搬送速度も重要である。樹脂組成物のエンボスロールへの付着を低減するためには、上述した離型剤の選定も重要である。
【０１２０】
光硬化性樹脂層にエンボス加工を行い、スタンパーから剥がした後、紫外線や電子線等を照射して樹脂層を光硬化させる。ホログラムは一般的には透過型であるため、光硬化させた樹脂層に反射層を設ける必要がある。反射層として光を反射する金属薄膜を用いると不透明タイプのホログラムとなり、透明で且つホログラム層と屈折率差がある物質を用いた反射層を設ける場合は透明タイプとなるが、どちらも使用できる。金属薄膜からなる反射層は、昇華、真空蒸着、スパッタリング、反応性スパッタリング、イオンプレーティング、電気メッキ等の公知の方法で形成可能である。
【０１２１】
不透明タイプのホログラムを形成する金属薄膜としては、例えば、Ｃｒ、Ｔｉ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ａｇ、Ａｕ、Ｇｅ、Ａｌ、Ｍｇ、Ｓｂ、Ｐｂ、Ｐｄ、Ｃｄ、Ｂｉ、Ｓｎ、Ｓｅ、Ｉｎ、Ｇａ、Ｒｂ等の金属及びその酸化物、窒化物等を単独若しくは２種類以上組み合わせてからなり、化学蒸着や物理蒸着等の方法で形成できる。上記金属薄膜の中でもＡｌ、Ｃｒ、Ｎｉ、Ａｇ、Ａｕ等が特に好ましく、その膜厚は１〜１０，０００ｎｍ、望ましくは２０〜２００ｎｍの範囲である。
【０１２２】
透明タイプのホログラムを形成する薄膜は、ホログラム効果を発現できる光透過性のものであれば、いかなる材質のものも使用できる。例えば、ホログラム形成層（光硬化性樹脂層）の樹脂と屈折率の異なる透明材料を用いることができる。この場合の屈折率は、ホログラム形成層の樹脂の屈折率より大きくても小さくてもよいが、屈折率の差は０．１以上が好ましく、より好ましくは０．５以上であり、１．０以上が最適である。透明タイプのホログラムを形成する薄膜としては、金属性透明反射膜がある。好適に使用される透明タイプ反射層としては、酸化チタン（ＴｉＯ₂）、硫化亜鉛（ＺｎＳ）等が挙げられる。
【０１２３】
また、例えば、高屈折率フィラーを分散した塗工液の塗工、金や銀のコロイド溶液の塗工、ゾルゲル反応に代表される有機金属化合物の加水分解重縮合反応による塗膜形成等により形成される、高屈折率材料膜を使用することもできる。
【０１２４】
凹凸パターン受容体は、微細凹凸パターンの表面構造を付与すべき最終製品であってもよいが、中間的な転写媒体であってもよい。すなわち本発明においては、上記光硬化性樹脂組成物を第一の支持体に塗布して微細凹凸パターン形成層を形成することで転写箔を作製し、この転写箔の微細凹凸パターン形成層に微細凹凸パターンを形成し、当該微細凹凸パターン形成層を反応硬化させた後で、第二の支持体（最終製品）上に転写することが可能である。転写箔を用いる場合には、最終製品の表面に直接エンボス加工を行う必要が無い、或いは、転写箔上に予め微細凹凸パターンを大量連続形成することができる等の利点があり、例えば、複雑な表面形状の物品等の直接エンボス加工を行うことが困難な物品の表面や、ロール状に巻き取ることができないガラス、プラスチック、金属板等の支持体に、微細凹凸パターンを連続転写によって形成することも可能である。
【０１２５】
本発明において微細凹凸パターン転写箔は、第一の支持体上に、少なくとも上記本発明の光硬化性樹脂組成物からなり、且つ、第一の支持体から剥離して第二の支持体に転写することが可能な状態で微細凹凸パターン形成層が設けられている積層体であり、必要に応じて、上記微細凹凸パターン形成層に加えて剥離層、反射層、接着剤層或いはその他の層の１又は２以上を設けることができる。例えば図１に示すように、転写箔１は、支持体２上に剥離層３、微細凹凸パターン形成層（光硬化性樹脂組成物層）４、反射層（不透明反射層又は微細凹凸パターン形成層とは屈折率の異なる透明層）５、及び、接着剤層６を順次積層した構成としてもよい。
【０１２６】
転写箔を作製する場合の支持体としては、通常、可撓性のある基材フィルムが用いられ、強度や耐熱性等の点でポリエチレンテレフタレート、ポリエチレン、ポリプロピレン、エチレン−酢酸ビニル共重合体、ポリ酢酸ビニル、ポリビニルアルコール、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリスチレン、ポリメチルメタクリレート、ナイロン、ポリエチレンテレフタレート、ポリイミド、ポリカーボネート、ポリノルボルネン、トリアセチルセルロース等のプラスチックフィルムが適しているが、プラスチックフィルムに限られず、また、可撓性が無くてもよく、金属板や紙等の他の材質を支持体として利用してもよい。また、紙等の含浸性ある支持体を用いる場合には、支持体組織内に微細凹凸パターン形成層が含浸した状態で形成されてもよく、このような状態であっても支持体上に設けられた微細凹凸パターン形成層の一形態に含まれる。また、ホログラム等の微細凹凸パターンの大量生産性を考慮して基材フィルムとして連続フィルムを用いてもよいが、枚葉状の基材フィルムを用いてもよい。
【０１２７】
剥離層は、転写箔の剥離性や箔切れ性を向上させる目的で微細凹凸パターン形成層の下層に必要に応じて設けられ、転写箔から何らかの被転写面（第二の支持体）に微細凹凸パターン形成層と共に転写された後は最表面になる層である。剥離層としては、例えば、アクリル樹脂、ポリエステル樹脂、ポリ塩化ビニル樹脂、セルロース樹脂、シリコーン樹脂、塩化ゴム、カゼイン、各種界面活性剤、金属酸化物等の中から１種のみ選んで単独で又は２種以上を選んで混合して用いることができる。または、微細凹凸パターン形成層に使用する本発明の光硬化性樹脂組成物に、上記の剥離性材料を添加剤として添加したものも、剥離層として用いることができる。
【０１２８】
反射層は、例えばレリーフホログラムを形成する場合に微細凹凸パターン上に設けられる。反射層は透明タイプ又は不透明タイプのいずれでもよく、上述したような金属薄膜又は高屈折率膜で形成できる。
【０１２９】
また、接着剤層は、微細凹凸パターン形成層の転写性、及び、転写後における被転写面に対する密着性を向上させる目的で、或いは、エンボス加工後の微細凹凸パターン形成層の表面を反射膜や保護膜で被覆する場合には、これらの層に対する密着性を向上させる目的で微細凹凸パターン形成層の最表面に設けられ、微細凹凸パターン形成層と共に転写された後は最下層となる層である。
【０１３０】
接着剤層は、公知の感熱性接着樹脂、感圧性接着樹脂、２液硬化型接着剤、光硬化型接着剤の中から適宜選んで使用できる。感熱性接着樹脂としては、例えば、ポリイソプレンゴム、ポリイソブチレンゴム、スチレンブタジエンゴム等のゴム系；ポリ（メタ）アクリル酸メチル、ポリ（メタ）アクリル酸エチル、ポリ（メタ）アクリル酸プロピル、ポリ（メタ）アクリル酸ブチル、ポリ（メタ）アクリル酸−２−エチルヘキシル等の（メタ）アクリル酸エステル系；ポリイソブチルエーテル等のポリビニルエーテル系；ポリ酢酸ビニル、塩化ビニル−酢酸ビニル共重合体等のポリ塩化ビニル系；ポリアクリルアミド、ポリメチロールアクリルアミド等のポリアミド系；ポリ塩化ビニル等の塩化ビニル系；ポリビニルブチラール、酢酸ビニル／アクリル酸オクチル、酢酸ビニル／アクリル酸ブチル、塩化ビニリデン／アクリル酸ブチル等の他のビニル系；ポリスチレン等の芳香族ビニル系；及びポリ塩化オレフィン等が挙げられ、これらの中から１種のみ選んで単独で又は２種以上を組み合わせて用いることができる。
【０１３１】
レリーフホログラム転写箔の作成手順の一例を、以下に説明する。なお、使用される符号は図１を参照するためのものである。先ず、ポリエチレンテレフタレート等の連続プラスチックからなる基材フィルム２をロールストックから繰り出す。繰り出した基材フィルムの上に剥離剤の塗工液をロールコーターを用いて塗布し、次いで、前記塗工液に含まれている有機溶剤が飛散する温度、例えば、ｌ００〜１６５℃に設定した加熱炉内に０．１〜１分間程度導いて乾燥させて、剥離層３を形成する。この剥離層３の上に、引き続き光硬化性樹脂組成物からなる微細凹凸パターン形成材料をロールコーターを用いて塗布し、次いで、組成物に含まれている有機溶剤が飛散する温度、例えば、ｌ００〜１６５℃に設定した加熱炉内に０．１〜１分間程度導いて乾燥させて微細凹凸パターン形成層４を形成して転写箔１を作製する。上記ロールコーター以外の塗工機としては、例えばグラビアコーター、カーテンコーター、フローコーター、リップコーター、ドクターブレードコーター等も使用できる。微細凹凸パターン形成層の厚さは、通常０．１〜５．０μｍ程度である。作製した転写箔１は再び巻き取られてロールストックとされ、保存又は運搬される。
【０１３２】
次に、転写箔１をロールストックから繰り出し、微細凹凸パターン形成層の表面にレリーフホログラムのスタンパーを圧接してエンボス加工を行い、微細凹凸パターン（図示せず）を形成する。
【０１３３】
ホログラムパターンのエンボス加工は、例えば、レーザー光や電子線を用いて作った母型から引き続き作成したスタンパーを周面に装着した金属ロ−ルとペーパーロールよりなる１対のエンボスローラーを使用して通常の方法で、例えば、熱ロール温度１００〜２００℃、プレス圧５×１０³〜５×１０⁶Ｐａで行う。熱ロール温度を上記範囲より高くすると、エンボス加工を高速で行うことができるが、基材フィルムのダメージが大きくなる。また、熱ロール温度を上記範囲より低くすると、樹脂温度を上昇させるのに時間がかかるので、エンボス工程が遅くなる。なお、複製装置のエンボスローラーとしては、樹脂製版によりマスターホログラムから複製ホログラムを作成し、これをシリンダー上に貼り付けたものも使用できる。
【０１３４】
この場合も、片面又は両面にエンボス加工を行うことが可能である。光硬化性樹脂層にエンボス加工を行い、スタンパーから剥がした後、光を照射して樹脂層を硬化させる。硬化に用いる光としては、上述したように高エネルギー電離放射線及び紫外線が挙げられる。
【０１３５】
硬化後、微細凹凸パターンの上には、必要に応じて、さらに金属蒸着層や高屈折率材料層等の反射膜や、耐擦傷性や耐汚染性を高めるための透明保護膜を形成してもよい。また、微細凹凸パターン形成層の上に反射膜や保護膜等の層を付加する場合には、さらにその上に接着剤層を付加してもよい。
【０１３６】
このようにして微細凹凸パターン形成層の上に、微細凹凸パターンを形成し硬化させた転写箔は、再び巻き取られてロールストックとされ、保存又は運搬される。
【０１３７】
次に、微細凹凸パターンを形成した転写箔をロールストックから繰り出し、その微細凹凸パターン形成層の上に、第二の支持体の被転写面を向き合わせて重ね合せ、ホログラムを転写しようとする部分の転写箔を基材フィルム側から加圧ローラや加圧板で加熱・加圧して溶融接着させた後、転写箔を剥離することにより、微細凹凸パターンを有する微細凹凸パターン形成層が第二の支持体上に転写される。転写の際の温度及び圧力は、加圧方式（ロール式、スタンピング式）及び加圧時間等の加圧方法に関する要因のほか、支持体の材質と溶融温度、感熱接着剤の溶融温度、感熱接着剤と支持体材質の密着性等の要因によって条件が大きく異なってくるため、適宜調節する。
【０１３８】
このようにして、光硬化性樹脂組成物の硬化物からなると共に、レリーフホログラムの微細凹凸パターンを形成した表面構造を有する硬化樹脂層を備えた光学物品が得られる。
【０１３９】
（光学物品）
本発明によれば、上記レリーフホログラムと同様の方法により又は上記方法を必要に応じて修正して、光硬化性樹脂組成物の硬化物からなると共に、様々な光学的機能を有する微細凹凸パターンを形成した表面構造を有する硬化樹脂層を備えた光学物品を作製することが可能である。
【０１４０】
従来、エンボス加工で複製されているホログラムの凹凸パターンは、幅（ピッチ）が約５００〜１５００ｎｍ及び幅に対する深さ（深さ／幅）が１／３以下程度であるものが一般的である。本発明によれば、このような凹凸パターンを複製できることは言うまでもなく、より高度な光学的機能を有する複雑な微細凹凸パターン、例えば、凹凸パターンの幅（ピッチ）が約２００ｎｍ以下であったり、或いは、幅に対する深さ（深さ／幅）が１／２以上であるパターンを複製する場合でも、スタンパーの圧接時にキャビティ内に微細凹凸パターン形成材料を充分に流し込むことができ、スタンパーを引き剥がす時に版取られを起こさず、スタンパーを取り除いた後のパターン崩れも起こし難いため、微細凹凸パターンを精度良く且つエンボス加工により大量連続生産することが可能である。
【０１４１】
本発明の微細凹凸パターン形成材料を用いるエンボス加工により作製される光学物品としては、（１）セキュリティ用途で使用されるレリーフホログラムや回折格子、例えばクレジットカード、ＩＤカード、商品券、紙幣等に付されるものや、（２）グラフィックアーツ及び意匠用途で使用されるレリーフホログラムや回折格子、例えば、いわゆるプリクラ等のアミューズメント商品又は景品、包装、葉書・封書、ノベルティグッズ等に付されるものや、（３）全光線及び／又は特定の波長の光の反射、透過、散乱、偏光、集光又は干渉の少なくとも一つを制御する光学素子、例えば、反射板、散乱板、偏光板、レンズ、波長選択素子、反射防止板、複屈折波長板、サブ波長構造を持つ光学素子等の光学素子等として用いられるものや、（４）情報記録素子、例えば、情報記録ホログラム、光カード、光ディスク等として用いられるもの等を挙げることができる。
【０１４２】
本発明は、レリーフホログラムや回折格子以上に複雑又は精密に光を制御する用途に適用可能であるが、レリーフホログラムや回折格子に適用する場合にも、ただ単に明るいホログラムを得るだけでなく、複雑なデザインをもつレリーフホログラムや回折格子を形成できる。
【０１４３】
さらに本発明によれば、非常に高い精度で微細凹凸パターンを形成できるので、光学物品に付与すべき微細凹凸パターンを型にして相補的な凹凸パターンを複製し、これをスタンパーとして使用することが可能である。
【０１４４】
【実施例】
（実施例１）
（１）バインダー樹脂（Ａ）の製造
冷却器、滴下ロート及び温度計付きの２リットルのフラスコに、トルエン４０ｇ、メチルエチルケトン４０ｇをアゾ系の重合開始剤と共に仕込み、２−ヒドロキシメチルメタクリレート２０．８ｇ、メチルメタクリレート３９．０ｇ、イソボルニルメタクリレート４５．０ｇ、トルエン２０ｇ、及び、メチルエチルケトン２０ｇの混合液を滴下ロートで滴下させながら１００℃の温度下で８時間反応させた後、室温まで冷却した。これに、２−イソシアネートエチルメタクリレート（昭和電工製、カレンズＭＯＩ）２３．４ｇ、トルエン２０ｇ及びメチルエチルケトン２０ｇの混合液を加えて、ラウリン酸ジブチル錫を触媒として付加反応させた。反応生成物のＩＲ分析により、イソシアネートの吸収ピークの消失を確認し、反応を終了した。得られた樹脂溶液の固形分は３８．２重量％、分子量はポリスチレン換算で３０，０００、炭素間二重結合（Ｃ＝Ｃ）の導入量は１２．５％であった。
【０１４５】
（２）光硬化性樹脂組成物の調製
上記バインダー樹脂（Ａ）及びその他の成分を下記配合割合で混合し、メチルエチルケトンで希釈して固形分濃度を２０重量％に調節し、本実施例１の光硬化性樹脂組成物１を調製した。
【０１４６】
＜光硬化性樹脂組成物１＞
・バインダー樹脂（Ａ）（固形分基準）：７０重量部
・多官能オリゴマー（ジペンタエリスリトールヘキサアクリレート、商品名：ＫＡＹＡＲＡＤ ＤＰＨＡ、日本化薬製）：３０重量部
・離型剤（アミノ変性反応性シリコーンオイル、商品名：ＫＦ−８６０、信越化学工業製）：５重量部
・光重合開始剤（商品名：イルガキュア１８４、チバスペシャルティケミカルズ製）：５重量部
・球状コロイダルシリカ（商品名：ＭＥＫ−ＳＴ、日産化学工業製）（固形分基準）：７０重量部
（実施例２）
実施例１で製造したバインダー樹脂（Ａ）及びその他の成分を下記配合割合で混合し、メチルエチルケトンで希釈して固形分濃度を２０重量％に調節し、本実施例２の光硬化性樹脂組成物２を調製した。
【０１４７】
＜光硬化性樹脂組成物２＞
・バインダー樹脂（Ａ）（固形分基準）：６０重量部
・ウレタンアクリレート（商品名：紫光ＵＶ−３５２０ＴＬ、日本合成化学工業製）（固形分基準）：３０部
・離型剤（シリコーンレジン、商品名：ＫＦ−７３１２、信越化学工業製）：１部
・光重合開始剤１（商品名：イルガキュア９０７、チバスペシャルティケミカルズ製）：２部
・光重合開始剤２（商品名：イルガキュア１８４、チバスペシャルティケミカルズ製）：３部
・球状コロイダルシリカ（商品名：ＭＥＫ−ＳＴ、日産化学工業製）（固形分基準）：９０部
（実施例３）
実施例１で製造したバインダー樹脂（Ａ）及びその他の成分を下記配合割合で混合し、メチルエチルケトンで希釈して固形分濃度を２０重量％に調節し、本実施例３の光硬化性樹脂組成物３を調製した。
【０１４８】
＜光硬化性樹脂組成物３＞
・バインダー樹脂（Ａ）（固形分基準）：７０重量部
・ポリエステルアクリレート（商品名：アロニックスＭ−９０５０、東亜合成化学工業製）：２０重量部
・離型剤（アミノ変性シリコーンオイル、商品名：ＫＦ−８０１２、信越化学工業製）：３重量部
・単官能モノマー（イソボルニルメタクリレート、商品名：ＳＲ−４２３、サートマー製）：１０重量部
・光重合開始剤（商品名：イルガキュア２９５９、チバスペシャルティケミカルズ製）：３重量部
・アルミニウムカップリング剤（商品名：ＡＬＣＨ−ＴＲ、川研ファインケミカル製）：５重量部
・球状コロイダルシリカ（商品名：ＭＥＫ−ＳＴ、日産化学工業製）（固形分基準）：８０重量部
（実施例４）
＜光硬化性樹脂組成物４＞
（１）バインダー樹脂（Ｂ）の製造
冷却器、滴下ロート及び温度計付きの２リットルのフラスコに、トルエン４０ｇ、メチルエチルケトン４０ｇをアゾ系の重合開始剤と共に仕込み、２−ヒドロキシメチルメタクリレート２５．６ｇ、メチルメタクリレート３６．０ｇ、イソボルニルメタクリレート１０９．６ｇ、トルエン２０ｇ、及び、メチルエチルケトン２０ｇの混合液を滴下ロートを経て約２時間かけて滴下させながら１００〜１１０℃の温度下で８時間反応させた後、室温まで冷却した。
【０１４９】
これに、２−イソシアネートエチルメタクリレート（昭和電工製、カレンズＭＯＩ）２８．８ｇ、トルエン２０ｇ及びメチルエチルケトン２０ｇの混合液を加えて、ラウリン酸ジブチル錫を触媒として付加反応させた。反応生成物のＩＲ分析により、イソシアネートの吸収ピークの消失を確認し、反応を終了した。得られた樹脂溶液の固形分は３７．０重量％、粘度は１３０ｍＰａ（３０℃）、分子量はポリスチレン換算で６０，０００、炭素間二重結合（Ｃ＝Ｃ）の導入量は１２．８％であった。
【０１５０】
（２）光硬化性樹脂組成物の調製
上記バインダー樹脂（Ｂ）及びその他の成分を下記配合割合で混合し、メチルエチルケトンで希釈して固形分濃度を２０重量％に調節し、本実施例４の光硬化性樹脂組成物４を調製した。
【０１５１】
＜光硬化性樹脂組成物４＞
・バインダー樹脂（Ｂ）（固形分基準）：６０重量部
・多官能オリゴマー（商品名：紫光ＵＶ−１７００Ｂ、日本合成化学工業製）：４０重量部
・離型剤（シリコーンレジン、商品名：Ｘ−２１−３０５６、信越化学工業製）：１重量部
・光重合開始剤（商品名：イルガキュア９０７、チバスペシャルティケミカルズ製）（固形分基準）：５重量部
・球状コロイダルシリカ（商品名：ＭＥＫ−ＳＴ、日産化学工業製）（固形分基準）：６０重量部
（実施例５）
実施例４で製造したバインダー樹脂（Ｂ）及びその他の成分を下記配合割合で混合し、メチルエチルケトンで希釈して固形分濃度を２０重量％に調節し、本実施例５の光硬化性樹脂組成物５を調製した。
【０１５２】
＜光硬化性樹脂組成物５＞
・バインダー樹脂（Ｂ）（固形分基準）：７０重量部
・離型剤（シリコーンレジン、商品名：ＫＦ−７３１２、信越化学工業製）：１重量部
・多官能オリゴマー（商品名：ＳＲ−３９９、サートマー製）：１０重量部
・アルミニウムカップリング剤（商品名：ＡＬＣＨ−ＴＲ、川研ファインケミカル製）：５重量部
・光重合開始剤（商品名：イルガキュア９０７、チバスペシャルティケミカルズ製）：５重量部
・球状コロイダルシリカ（商品名：ＭＥＫ−ＳＴ、日産化学工業製）（固形分基準）：３０重量部
（実施例６）
実施例４で製造したバインダー樹脂（Ｂ）及びその他の成分を下記配合割合で混合し、メチルエチルケトンで希釈して固形分濃度を２０重量％に調節し、本実施例６の光硬化性樹脂組成物６を調製した。
【０１５３】
＜光硬化性樹脂組成物６＞
・バインダー樹脂（Ｂ）（固形分基準）：３０重量部
・非重合性バインダー樹脂（商品名：ダイヤナールＢＲ−８５、三菱レイヨン製）：３０重量部
・多官能モノマー（ジペンタエリスリトールヘキサアクリレート、商品名：ＫＡＹＡＲＡＤ ＤＰＨＡ、日本化薬製）：３０重量部
・離型剤（アミノ変性シリコーンオイル、商品名：ＫＦ−８０１２、信越化学工業製）：１０重量部
・光重合開始剤（商品名：イルガキュア１８４、チバスペシャルティケミカルズ製）：５重量部
・球状コロイダルシリカ（商品名：ＭＥＫ−ＳＴ、日産化学工業製）（固形分基準）：６０重量部
（実施例７）
実施例１において、球状コロイダルシリカ７０重量部に代えて、針状コロイダルシリカ（商品名：ＩＰＡ−ＳＴ−ＵＰ、日産化学工業製）（固形分基準）１０重量部を用いる以外は実施例１と同様にして、本実施例７の光硬化性樹脂組成物７を調製した。
【０１５４】
（実施例８）
実施例２において、球状コロイダルシリカ９０重量部に代えて、針状コロイダルシリカ（商品名：ＩＰＡ−ＳＴ−ＵＰ、日産化学工業製）（固形分基準）１５重量部を用いる以外は実施例２と同様にして、本実施例８の光硬化性樹脂組成物８を調製した。
【０１５５】
（実施例９）
実施例３において、球状コロイダルシリカ８０重量部に代えて、針状コロイダルシリカ（商品名：ＩＰＡ−ＳＴ−ＵＰ、日産化学工業製）（固形分基準）１０重量部を用いる以外は実施例３と同様にして、本実施例９の光硬化性樹脂組成物９を調製した。
【０１５６】
（実施例１０）
実施例４において、球状コロイダルシリカ６０重量部に代えて、針状コロイダルシリカ（商品名：ＩＰＡ−ＳＴ−ＵＰ、日産化学工業製）（固形分基準）１０重量部を用いる以外は実施例４と同様にして、本実施例１０の光硬化性樹脂組成物１０を調製した。
【０１５７】
（実施例１１）
実施例５において、球状コロイダルシリカ３０重量部に代えて、針状コロイダルシリカ（商品名：ＩＰＡ−ＳＴ−ＵＰ、日産化学工業製）（固形分基準）５重量部を用いる以外は実施例５と同様にして、本実施例１１の光硬化性樹脂組成物１１を調製した。
【０１５８】
（実施例１２）
実施例６において、球状コロイダルシリカ６０重量部に代えて、針状コロイダルシリカ（商品名：ＩＰＡ−ＳＴ−ＵＰ、日産化学工業製）（固形分基準）１０重量部を用いる以外は実施例６と同様にして、本実施例１２の光硬化性樹脂組成物１２を調製した。
【０１５９】
（比較例１乃至６）
上記実施例１乃至６において、コロイダルシリカを配合しなかった他は全て同様にして、比較例の光硬化性樹脂組成物１乃至６を調製した。
【０１６０】
（実施例１３）
（１）ラベルタイプ微細凹凸パターンシートの作成
前記各実施例及び比較例の光硬化性樹脂組成物を各々、厚さ５０μｍの片面易接着性処理ポリエチレンテレフタレートフィルム（ダイアホイルＴ６００Ｅ、ダイアホイルヘキスト製）の易接着処理面上にグラビアコーターで塗工し、１００℃で乾燥して溶剤を揮発させて乾燥膜厚が２ｇ／ｍ²の複製用感光性フィルムを形成した。
【０１６１】
次に、複製装置のエンボスローラーに、レーザー光を用いて作った母型から作成したプレススタンパーを設置し、複製用感光性フィルムを当該複製装置の給紙側にセットし、１５０℃で加熱プレスして微細な凹凸パターンを形成させた。次に、水銀灯より発生した紫外線を照射して複製用感光性フィルムを光硬化させ、引き続き、真空蒸着法によりアルミニウムを蒸着して反射型の微細凹凸パターンシートを得た。
【０１６２】
（２）ラベルタイプ微細凹凸パターンシートの評価
ラベルタイプ微細凹凸パターンシートの作成途中で得られる中間製品、ラベルタイプ微細凹凸パターンシートの完成品について、下記の評価を行った。結果を第１表に示す。
【０１６３】
＜評価項目＞
（１）耐ブロッキング性
エンボス加工を行なう前の複製用感光性フィルムを巻き取り状態で室温、遮光状態で１ヶ月保管し、表面のブロッキング状態を目視で観察し、下記基準で評価した。
◎：良好
○：表面に樹脂の溶けた跡は若干残るが、貼り付きはない
×：フィルムに貼り付きがあり、表面の樹脂が溶け出して荒れている。
【０１６４】
（２）賦形性
プレススタンパーによりエンボスした微細凹凸パターンを、ＡＦＭ（原子間力顕微鏡）による観察像で比較し、下記基準で評価した。
◎：スタンパーによる加熱プレス時間を１／２に短縮しても形状を正確に再現する。
○：良好、すなわちプレススタンパーの形状を正確に再現している。
×：不良、すなわち正確に再現せずに形状に「だれ」が見られ、不正確で丸みを帯びている。
【０１６５】
（３）賦形維持性
プレススタンパーによりエンボスした微細凹凸パターンに紫外線を露光し、後工程を通して最終製品としたものについてＡＦＭ観察像で比較し、下記基準で評価した。
○：良好、すなわち後工程を経過した後もプレススタンパーの形状を正確に再現している。
×：不良、すなわち正確に再現せずに形状に「だれ」が見られ、丸みを帯びて変形している。
【０１６６】
（４）耐熱性
最終製品を１００℃の環境下に２時間放置した後の状態を観察し、下記基準で評価した。
○：良好、すなわち異常が無かった。
×：不良、すなわち変色、変形等の異常が生じた。
【０１６７】
（５）蒸着適性（セロハンテープ碁盤目剥離試験）
微細凹凸パターン形成面に、真空蒸着法によりアルミニウム層を蒸着した後、蒸着膜にカッターで縦１１本×横１１本の傷を直交させて付け、１００個の碁盤目状の桝目を設けた。その上からセロハンテープを強く密着させた後、一気に引き剥がし、膜面に残った桝目の数を数え、密着性を評価し、下記基準で評価した。
○：良好、すなわち残った桝目の数が９５以上である。
×：不良、すなわち残った桝目の数が９４以下である。
【０１６８】
【表１】

【０１６９】
（実施例１４）
（１）微細凹凸パターン転写箔シートの作成
厚さ２５μｍのポリエチレンテレフタレートフィルム（ルミラーＴ６０、東レ製）に、剥離性のニス（商品名：ハクリニス４５−３、昭和インク工業所製）をグラビアコート法で塗工し、１００℃で乾燥して溶剤を揮発させて、乾燥膜厚が１ｇ／ｍ²の剥離層を形成した。この剥離層面に、前記各実施例及び比較例の光硬化性樹脂組成物を各々、グラビアコーターで塗工し、１００℃で乾燥して溶剤を揮発させて乾燥膜厚が２ｇ／ｍ²の複製用感光性フィルムを形成した。
【０１７０】
次に、複製装置のエンボスローラーに、レーザー光を用いて作った母型から作成したプレススタンパーを設置し、複製用感光性フィルムを当該複製装置の給紙側にセットし、１５０℃で加熱プレスして微細な凹凸パターンを形成させた。次に、水銀灯より発生した紫外線を照射して複製用感光性フィルムを光硬化させ、引き続き、真空蒸着法によりアルミニウムを蒸着して反射型のレリーフホログラムを作成した。この表面に、アクリル系感熱接着剤をグラビアコートで塗工し、１００℃で乾燥して溶剤を揮発させて乾燥膜厚が１ｇ／ｍ²の接着剤層を形成し、微細凹凸パターン転写箔シートを得た。この転写箔シートから、さまざまな物品の表面にレリーフホログラムを転写することが可能であり、立体像を写し出す印刷物やディスプレイを作成することができる。
【０１７１】
（２）微細凹凸パターン転写箔シートの評価
微細凹凸パターン転写箔シートの作成途中で得られる中間製品、微細凹凸パターン転写箔シートの完成品について、下記の評価を行った。結果を第２表に示す。
【０１７２】
＜評価項目＞
（１）耐ブロッキング性
実施例１３と同様に行った。すなわち、エンボス加工を行なう前の複製用感光性フィルムを巻き取り状態で室温、遮光状態で１ヶ月保管し、表面のブロッキング状態を目視で観察し、下記基準で評価した。
◎：良好
○：表面に樹脂の溶けた跡は若干残るが、貼り付きはない
×：フィルムに貼り付きがあり、表面の樹脂が溶け出して荒れている。
【０１７３】
（２）賦形性
実施例１３と同様に行った。すなわち、プレススタンパーによりエンボスした微細凹凸パターンを、ＡＦＭ（原子間力顕微鏡）による観察像で比較し、下記基準で評価した。
◎：スタンパーによる加熱プレス時間を１／２に短縮しても形状を正確に再現する。
○：良好、すなわちプレススタンパーの形状を正確に再現している。
×：不良、すなわち正確に再現せずに形状に「だれ」が見られ、不正確で丸みを帯びている。
【０１７４】
（３）賦形維持性
実施例１３と同様に行った。すなわち、プレススタンパーによりエンボスした微細凹凸パターンに紫外線を露光し、後工程を通して最終製品としたものについてＡＦＭ観察像で比較し、下記基準で評価した。
○：良好、すなわち後工程を経過した後もプレススタンパーの形状を正確に再現している。
×：不良、すなわち正確に再現せずに形状に「だれ」が見られ、丸みを帯びて変形している。
【０１７５】
（４）耐熱性
実施例１３と同様に行った。すなわち、最終製品を１００℃の環境下に２時間放置した後の状態を観察し、下記基準で評価した。
○：良好、すなわち異常が無かった。
×：不良、すなわち変色、変形等の異常が生じた。
【０１７６】
（５）耐擦傷性
＃００００のスチールウールで加工品の表面を１０回擦ったときの表面を観察し、下記基準で評価した。
○：良好、すなわち表面に何の変化も無かった。
×：不良、すなわち表面が傷ついた。
【０１７７】
（６）転写箔適性
微細凹凸パターン形成面に、真空蒸着法によりアルミニウム層を蒸着した後、ヒートシール用アクリル系接着剤を塗工したものを、ポリ塩化ビニル製カード上に転写し、転写箔として用いた場合の箔切れ性を下記基準で評価した。
○：良好、すなわち転写型に対し形状良く転写された。
×：不良、すなわち箔残りや欠けが発生した。
【０１７８】
【表２】

【０１７９】
【発明の効果】
以上に述べたように、本発明に係る光硬化性樹脂組成物には無機超微粒子が配合されているので、当該光硬化性樹脂組成物からなる光硬化性樹脂層にプレススタンパーを押圧して微細凹凸パターンを賦形し、スタンパ−を取り外した後の、露光工程や蒸着工程等のプロセス途中で、樹脂組成物自身の弾性により微細凹凸パターンが丸みを帯びて型崩れするのを防ぐことができる。
【０１８０】
従って、プレススタンパーを露光工程に持ち込まずにスタンピング工程で連続使用することができ、光学物品を効率よく連続生産性することができる。
【０１８１】
また、本発明の光硬化性樹脂組成物は、無機超微粒子が配合されることによって耐ブロッキング性にも優れており、基材フィルム上に光硬化性樹脂層を形成した中間積層体をロール状に巻き取って一時的に貯蔵し、別の場所へ運搬してスタンピングを行うことも可能である。
【０１８２】
さらに、本発明に係る光硬化性樹脂組成物の主バインダーとして、アクリル樹脂、ウレタンアクリレート、ポリエステルアクリレート、又は、それらを任意に組み合わせた混合物を用いる場合には、硬化後において透明性、強度、耐擦傷性、耐熱性、耐水性、耐薬品性、基材に対する密着性、可とう性、基材の屈曲や伸縮に対する追随性に優れていて光学物品に要求される一般的性能を十分に満足できると共に、スタンパーにより凹凸パターンを賦形するのに充分な成膜性、柔軟性及びクリープ性を示し、無機超微粒子と組み合わせることにより微細凹凸パターンを極めて正確に複製することができる。従って、性能の良い光学物品の表面構造を、スタンピング法により正確且つ高速に連続生産することが可能となる。
【図面の簡単な説明】
【図１】微細凹凸パターン転写箔の一例についての模式的断面図である。
【符号の説明】
１…転写箔
２…支持体
３…剥離層
４…微細凹凸パターン形成層
５…反射層
６…接着層[0001]
BACKGROUND OF THE INVENTION
The present invention is excellent in moldability and moldability maintenance, in particular, a photocurable resin composition suitable for forming a fine uneven surface structure of an optical article, a method for forming a fine uneven pattern using the same, The present invention also relates to a transfer foil, an optical article, and a stamper obtained by using these.
[0002]
[Prior art]
Conventionally, a photocurable resin composition is applied onto a support such as a polyester film to form a photocurable resin layer, and various types of optical functions can be exerted on the surface of the photocurable resin layer. After applying the fine concavo-convex pattern, the resin layer is cured by exposure with active energy rays such as ultraviolet rays and electron beams, and by laminating layers with different metal deposition and refractive index on the formed concavo-convex pattern surface, Optical articles such as diffraction gratings and relief holograms are formed.
[0003]
For optical articles with fine concavo-convex patterns, the accuracy of the concavo-convex pattern, transparency, strength, scratch resistance, heat resistance, water resistance, chemical resistance, adhesion to substrates, flexibility, etc. The general properties of the article are required. Therefore, it is first necessary that the photocurable resin composition, which is a forming material thereof, can satisfy these required performances of the optical article.
[0004]
As a method of forming a fine uneven surface structure of an optical article, a liquid photocurable resin composition is applied on a transparent support such as a polyester film to form a liquid photocurable resin layer, and a fine photoconductive resin layer is formed thereon. There is a so-called 2P method (Photo Polymer method) in which the stamper is removed after being cured by irradiating light from the support side in a state where the stamper having unevenness is pressed.
[0005]
As a photocurable resin composition that can be used in the 2P method, for example, Japanese Patent Publication No. 4-5681 discloses an oligomer having a hard segment (H), a soft segment (S), and a crosslinking reactive end segment (E). The containing composition is described. This oligomer composition can accurately reproduce the uneven pattern from the matrix, is excellent in releasability after exposure and curing, and is suitable for mass production, and has strength, flexibility, optical transparency or homogeneity, ordinary There is an advantage that an optical article excellent in resistance to a solvent can be obtained.
[0006]
However, in the 2P method, since light is irradiated from the back side of the support, if the support has light absorption, the curing is insufficient, the stamper cannot be removed until the curing is completed, and the process takes time. Since the curable resin layer is in a liquid state, air bubbles are likely to enter between the stamper and the stamper that is in pressure contact, or when the stamper is peeled off from the cured resin layer, stringing occurs on the surface of the resin layer, causing surface roughness. There is.
[0007]
As another method, a photocurable resin composition having a high viscosity or a solid at room temperature is coated on a support to form a photocurable resin layer, and then a stamper is pressed onto and peeled off, followed by light irradiation. There is a method of curing by performing (Japanese Patent Publication No. 5-46063, Japanese Patent Publication No. 6-85103).
[0008]
According to this method, the photocurable resin layer can be sufficiently cured because it is directly irradiated with light. Since the photocurable resin composition is highly viscous or solid, the support is wound up after storage or stored. Photocurable resin layer that can be transported and can be applied and replicated in separate processes, and the stamper can be peeled off and irradiated with light, so that the stamper can be pressed and cured in separate processes There is an advantage that bubbles can hardly enter between the stamper and the pattern can be formed accurately, and when the stamper is peeled off from the photocurable resin layer, the surface of the resin layer is less likely to be stringed.
[0009]
However, in the method using a photocurable resin composition having a high viscosity or a solid at room temperature, a part of the photocurable resin composition is adhered in the cavity of the stamper in order to peel off the stamper from the uncured resin layer. The stamper is peeled off from the uncured resin layer, which tends to remain (the phenomenon of plate-cutting), and the harder the photocurable resin composition flows into the stamper cavity as the uneven pattern to be replicated becomes finer. Then, since light is irradiated, there is a problem that pattern collapse is likely to occur until the curing is completed.
[0010]
Japanese Patent Application Laid-Open No. 2000-63459 describes a photocurable resin composition containing a urethane-modified acrylic resin having a bulky group and a release agent as essential components. This photo-curable resin composition contains a urethane-modified acrylic polymer having a cross-linkable reactive group, and can reproduce the concave / convex pattern of the mother mold with high accuracy. Other excellent properties such as transparency, strength, scratch resistance, heat resistance, water resistance, chemical resistance, adhesion to substrates, flexibility, etc. There is an advantage that it is excellent in followability to bending and expansion / contraction of the substrate.
[0011]
Further, according to the invention of the above-mentioned JP-A-2000-63459, a photocurable resin composition containing a urethane-modified acrylic resin is coated on a substrate and dried as necessary, so that a photocurable resin layer is obtained. And pressurizing (embossing) a press stamper on the surface, and forming a concavo-convex pattern of the press stamper (more precisely, a concavo-convex pattern complementary to the press stamper) into the resin layer, and then the resin layer The press stamper is removed from the substrate, and then exposed and cured to fix the uneven pattern. Accordingly, there is no need to bring a press stamper into the exposure process, embossing can be performed continuously, and the press stamper does not become an obstacle to exposure, and uniform and sufficient exposure can be performed in a short time.
[0012]
In addition, when removing the stamper from the uncured photo-curing resin layer, the photo-curing resin remains on the inner wall of the cavity of the stamper (the phenomenon of taking off the plate), and it is embossed continuously and accurately using the same stamper. There is a problem that it becomes difficult to perform processing. Against this problem, when the photocurable resin composition described in JP-A-2000-63459 is used, it is excellent in releasability even in an uncured state, and the photocurable resin is formed on the cavity inner wall of the stamper. There is an advantage that the composition is difficult to adhere.
[0013]
However, when the stamper is pressed after the photocurable resin composition is applied on the substrate as in the invention of JP 2000-63459 A and dried to form a film as necessary, the photocuring In some cases, the flexible resin composition lacks flexibility and fluidity, and does not spread sufficiently in every corner of the cavity space of the stamper, so that a desired fine concavo-convex pattern cannot be accurately formed.
[0014]
In addition, even if the fine concavo-convex pattern of the stamper can be accurately formed in the photocurable resin layer, when the exposure is performed after taking out the uncured photocurable resin layer from the stamper, the fine concavo-convex pattern By the time the formation process is completed, the fine concavo-convex pattern formed on the photocurable resin layer is rounded and deformed by the elasticity of the resin itself, resulting in loss of shape (referred to as “sag”). Such deformation is caused by, for example, the heat received from the stamper when the uncured photocurable resin layer is heat embossed, or the heat when UV is applied to the photocurable resin layer formed with a fine concavo-convex pattern. The main cause.
[0015]
As described above, in order to accurately and efficiently replicate a micro uneven pattern having an optical function using a photocurable resin composition, the photocurable resin composition contains almost no solvent. It has a film forming property in the state of the curable resin layer and has a formability sufficient to follow the cavity shape of the press stamper, and also during the process after removing the stamper from the photocurable resin layer It is required to have a shape-retaining property capable of holding the shape formed in (1) while keeping it sharp.
[0016]
Furthermore, in recent years, with the improvement of precision processing technology, very complicated optical fine concavo-convex patterns have been formed. These complex optical micro-concave patterns can form complex designed holograms, or highly reflect, transmit, scatter, polarize, collect or interfere with all rays and / or specific wavelengths of light. An optical element to be controlled or an information recording element can be formed. However, such a complicated fine concavo-convex pattern has a narrower concavo-convex pitch and / or deeper concavo-convex than conventional relatively simple holograms, so that it is more difficult to reproduce accurately. Moreover, the function cannot be fully exhibited unless the hologram is duplicated with higher accuracy than the case of duplicating a conventional relatively simple hologram.
[0017]
Such a complicated optical fine concavo-convex pattern can be printed even with the resin composition described in JP-A-2000-63459, and can be accurately reproduced without causing problems of resin moldability and pattern collapse. It is very difficult to do.
[0018]
On the other hand, JP 7-502128 A describes an optical element having a surface structure embossed with a transparent composite material showing a three-dimensional skeleton of inorganic or organically modified inorganic components of nanoscale particles in a polymer matrix. Yes. According to the present invention, the shrinkage rate can be minimized during embossing and curing operations. However, in this invention, a light or thermosetting resin composition containing an inorganic or organically modified inorganic component of nanoscale particles is applied to a substrate to form a light or thermosetting resin layer, and the resin layer To cure by exposure or heating while pressing the embosser, and if necessary, pre-curing to increase the viscosity before attaching the embosser and / or completing the copolymerization after removing the embosser Post-curing is performed. This invention basically cures the light or thermosetting resin layer in a state where the embosser is pressed. When the uncured resin layer is taken out of the embosser, it loses its shape due to its own elasticity. Nothing is said.
[0019]
[Problems to be solved by the invention]
The present invention has been achieved in view of the above-mentioned actual situation, and the first object thereof is a photocurable resin composition that is excellent in formability and moldability maintenance and can accurately replicate a transparent film having a fine uneven pattern. It is an object of the present invention to provide a material for forming a fine concavo-convex pattern that can accurately reproduce a very complicated fine concavo-convex pattern in recent years.
[0020]
In addition, the second object of the present invention is excellent in followability with respect to a cavity shape of a mother mold such as a stamper complementary to a fine uneven pattern of an optical article, and can be shaped accurately and shaped after shaping. To provide a photo-curable resin composition that is excellent in retention and is less likely to be deformed (sagging) in the process after being taken out of a matrix, and as a result, can accurately replicate a desired fine uneven pattern. is there.
[0021]
The third object of the present invention is to make it possible to accurately form a fine concavo-convex pattern having an optical function by making use of the characteristics of the photo-curable resin composition and to have a high productivity. Is to provide.
[0022]
The fourth object of the present invention is to utilize these photo-curable resin composition and fine concavo-convex pattern forming method, and to provide a fine concavo-convex pattern transfer foil, fine concavo-convex pattern with high precision of the fine concavo-convex pattern, and thus excellent optical performance. It is to provide an optical article and stamper having a pattern.
[0023]
[Means for Solving the Problems]
The photocurable resin composition according to the present invention provided to solve the above problems includes (A) a binder resin having a photopolymerizable functional group as an essential component, and (B) a thickness of 1 to 100 nm and a length. It has an elongated shape of 10 to 500 nm and an aspect ratio of 3 or more, and can be dispersed in a colloidal form in a diluting solvent for preparing a coating solution, and contains submicron-order inorganic ultrafine particles The photocurable resin composition is used for forming a fine uneven pattern of an optical article.
[0024]
Since the photocurable resin composition according to the present invention contains inorganic ultrafine particles, a fine concavo-convex pattern is formed by pressing a press stamper on the photocurable resin layer made of the photocurable resin composition. In addition, it is possible to prevent the fine concavo-convex pattern from being rounded and out of shape due to the elasticity of the resin composition itself during the process such as the exposure process and the vapor deposition process after the stamper is removed.
[0025]
Therefore, the press stamper can be continuously used in the stamping process without bringing it into the exposure process, and the optical article can be efficiently and continuously produced.
[0026]
In addition, the photocurable resin composition of the present invention has excellent anti-blocking properties because the surface tack is reduced by adding inorganic ultrafine particles, and a photocurable resin layer is formed on the base film. It is also possible to wind the intermediate laminate in a roll shape, temporarily store it, and transport it to another place for stamping.
[0027]
Moreover, the photocurable resin composition of this invention becomes easy to relieve | moderate the stress at the time of cure shrinkage by mix | blending inorganic ultrafine particles, and can solve the various problems resulting from distortion of cure shrinkage. For example, it is possible to suppress cracking, curling, wrinkling, etc. of the resin caused by curing shrinkage when the photocurable resin composition is cured. Alternatively, when a layer of the photocurable resin composition contained in the transfer foil is cured, a portion of the foil that is generated due to a difference in shrinkage rate from the adjacent layer, for example, a film substrate, a release layer, or a metal vapor deposition layer Cracks, kinks, wrinkles, etc. can be suppressed.
[0028]
It is preferable to use long and narrow inorganic ultrafine particles (B) as the inorganic ultrafine particles (B), since the anti-blocking property, creep characteristics and shape retention of the uneven pattern of the photocurable resin composition are particularly improved.
[0030]
In order to obtain sufficient creep characteristics and film properties, the content of the inorganic ultrafine particles (B) is preferably in the range of 0.1 to 70% by weight with respect to the total solid content of the photocurable resin composition. .
[0031]
The inorganic ultrafine particles (B) are preferably inorganic ultrafine particles having a hydrophobically treated surface in order to facilitate dispersion in a colloidal form.
[0032]
In the photocurable resin composition of the present invention, the polystyrene-converted molecular weight of the binder resin is preferably in the range of 2,000 to 500,000 in order to make the composition have sufficient film formability.
[0033]
The binder resin is preferably one or more selected from the group consisting of acrylic resins, urethane acrylate resins, and polyester acrylate resins. The acrylic resin, urethane acrylate resin, and polyester acrylate resin described above are transparent, strength, scratch resistance, heat resistance, water resistance, chemical resistance, adhesion to a substrate, flexibility, and substrate after curing. It has excellent followability to bending and expansion / contraction, and has sufficient film formability, flexibility and creep properties that can be formed into a film on a substrate and shape a concavo-convex pattern with a stamper, and combined with inorganic ultrafine particles Thus, the fine concavo-convex pattern can be reproduced very accurately.
[0034]
Furthermore, a fine concavo-convex pattern forming layer that can be transferred onto a support is formed using the photocurable resin composition of the present invention, and can be used as a transfer foil.
[0035]
Next, the optical article according to the present invention is made of a cured product of the photocurable resin composition according to the present invention, and has a surface structure in which a fine uneven pattern is formed.
[0036]
The optical article according to the present invention is excellent in transparency, strength, scratch resistance, heat resistance, water resistance, chemical resistance, adhesion to a substrate, flexibility, followability to bending and expansion / contraction of the substrate. It has a cured resin layer having a surface structure in which a fine concavo-convex pattern exhibiting a required optical function is accurately replicated, and can form fine concavo-convex patterns having various uses.
[0037]
Needless to say, by using the photocurable resin composition of the present invention, it is possible to replicate a relief hologram or a fine concavo-convex pattern of a diffraction grating, for example, a complicated fine concavo-convex pattern having a more advanced optical function, for example, all rays and / or Or, even if it is an optical element that controls at least one of reflection, transmission, scattering, polarization, condensing, or interference of light of a specific wavelength, or a fine uneven pattern such as an information recording element, it is continuous in large quantities with high accuracy and by embossing It can be produced and used as an optical article for these applications.
[0038]
Furthermore, since the photocurable resin composition of the present invention can form a fine concavo-convex pattern with very high accuracy, a complementary concavo-convex pattern is duplicated using a fine concavo-convex pattern to be applied to an optical article as a mold, and this is used as a stamper. It can be used as
[0039]
Next, in the method for forming a fine concavo-convex pattern according to the present invention, a concavo-convex pattern receptor provided with a fine concavo-convex pattern forming layer made of the photocurable resin composition according to the present invention is prepared, and a stamper is pressed against the surface thereof. Then, after forming the concavo-convex pattern, the fine concavo-convex pattern forming layer is reactively cured.
[0040]
According to the method for forming a fine concavo-convex pattern according to the present invention, a transparent film having a fine concavo-convex pattern can be duplicated with high accuracy. In particular, the surface structure of a high-performance optical article can be accurately and rapidly produced by a stamping method. Can be produced continuously.
[0041]
In the above method, it is preferable that the fine concavo-convex pattern forming layer is reactively cured after removing the stamper from the fine concavo-convex pattern forming layer. According to this method, even when the stamper is peeled off from the fine concavo-convex pattern forming layer, it is difficult to cause mold deformation even when reactively cured, and the fine concavo-convex pattern receiver provided with the fine concavo-convex pattern forming layer is rolled in an uncured state. Since it is difficult to cause blocking even when wound into a shape, it is possible to continuously mass-produce fine concavo-convex patterns.
[0042]
According to the present invention, it is possible to use a fine concavo-convex pattern transfer foil in which a fine concavo-convex pattern forming layer made of at least the above-mentioned photocurable resin composition is provided on the first support so as to be transferable. When using a fine concavo-convex pattern transfer foil, the surface of an article that is difficult to directly emboss, such as an article having a complicated surface shape, or a glass, plastic, metal plate, etc. that cannot be rolled up A fine concavo-convex pattern can be formed on the support by continuous transfer.
[0043]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below. The photocurable resin composition according to the present invention is a material used for forming a fine uneven pattern of an optical article, and (A) a binder resin having a photopolymerizable functional group as an essential component and (B) a coating It is characterized in that it can be dispersed in a colloidal form in a diluting solvent for preparing a liquid and contains inorganic ultrafine particles of submicron order.
[0044]
Furthermore, if necessary, the photocurable resin composition according to the present invention includes a monomer or oligomer having a photopolymerizable functional group, a release agent, an organometallic coupling agent, a photopolymerization initiator, a polymerization inhibitor, and the like. These components can be blended.
[0045]
In the present invention, a binder resin having a photopolymerizable functional group is used as the binder component.
[0046]
A photopolymerizable functional group is a functional group capable of forming a crosslinking bond between molecules of a binder resin by a visible light or invisible light including ionizing radiation such as ultraviolet rays and electron beams, and is directly activated by light irradiation. It may be a photopolymerizable functional group in a narrow sense that undergoes photopolymerization reaction, or it is polymerized by the action of active species generated from the photopolymerization initiator when irradiated with light in the presence of the photopolymerizable functional group and the photopolymerization initiator. It may be a photopolymerizable functional group in a broad sense that initiates and accelerates the reaction. Examples of the photopolymerizable functional group include those having radical photopolymerization reactivity such as ethylenic double bonds, and those having photocationic polymerization and photoanion polymerization reactivity such as cyclic ether groups such as epoxy groups. Among them, an ethylenic double bond is preferable. The ethylenic double bond may be any of (meth) acryloyl group, vinyl group, allyl group and the like, and (meth) acryloyl group is particularly preferable. In order to obtain sufficient crosslinkability, the binder resin preferably has at least two photopolymerizable functional groups in one molecule.
[0047]
In the present specification, (meth) acryloyl represents acryloyl and methacryloyl, (meth) acrylate represents acrylate and methacrylate, and (meth) acryl represents acryl and methacryl.
[0048]
In the present invention, from a resin having a photopolymerizable functional group, when coated on a support such as a base film, a film having a thickness sufficient to shape a fine uneven pattern can be obtained. It has film formability and flexibility that can form a fine concavo-convex pattern by pressing a stamper, creep properties, and transparency, strength, scratch resistance, heat resistance depending on the use of optical articles after photocuring That can form a surface structure of a fine concavo-convex pattern satisfying general properties such as property, water resistance, chemical resistance, adhesion to a substrate, and flexibility are appropriately selected and used as a binder resin.
[0049]
Since the binder resin has a film forming property that can exist as a film on the substrate without flowing in a state of containing little or no solvent, it is not a liquid monomer component but has a molecular weight of 2,000 to 500 in terms of polystyrene. The polymer component is preferably 5,000, particularly 5,000 to 200,000. When the molecular weight of the binder resin is less than 2,000, when the substrate coated with the resin composition is taken up, the coating surface is attached to the back surface of the substrate, and as a result, the coating surface This is not preferable because the smoothness of the resin composition is impaired, and when it exceeds 500,000, the surface is difficult to soften, so that the resin composition is difficult to enter the stamper and it is difficult to reproduce the shape. In addition, as the molecular weight of the binder resin is larger, the shape retaining property of the uneven pattern is more excellent.
[0050]
As the binder, a polymer having a polymerizable functional group, for example, an acrylic resin such as a urethane-modified acrylic resin or an epoxy-modified acrylic resin, a hard segment, a soft segment, and a polymerizable functional group as shown in JP-B-4-5681 A resin, a urethane acrylate resin, a polyester acrylate resin, a polyether acrylate resin, an epoxy acrylate resin, and the like can be used, and among them, it is preferable to use one or more of acrylic resin, urethane acrylate, and polyester acrylate in combination.
[0051]
Acrylic resin, urethane acrylate resin, and polyester acrylate resin are transparent, strength, scratch resistance, heat resistance, water resistance, chemical resistance, adhesion to substrate, flexibility, and bending and stretching of substrate after curing. In addition to being excellent in the following property, and having sufficient film formability, flexibility and creep property that can be formed into a film on a substrate and shape a concavo-convex pattern with a stamper, it is preferably used in the present invention. Of these, the urethane-modified acrylic resin of formula 1 is particularly preferred.
[0052]
Among the acrylic resin, urethane acrylate resin, and polyester acrylate resin described above, urethane-modified acrylic resin, urethane acrylate, and polyester acrylate are transparent after curing, strength, scratch resistance, heat resistance, water resistance, and chemical resistance. Basic properties such as adhesion to the substrate, flexibility, followability to bending and expansion / contraction of the substrate, and sufficient film forming property, flexibility, and creep property that can form an uneven pattern with a stamper Since the required performance is particularly excellent, it is preferably used in the present invention. Of these, the urethane-modified acrylic resin of Formula 1 is more preferable.
[0053]
As the acrylic resin, any polymer having a main chain obtained by copolymerizing a (meth) acrylate monomer and having at least one polymerizable functional group at the main chain terminal or side chain can be used. . In order to introduce a polymerizable functional group into an acrylic resin, a monomer having a polymerizable functional group in the main chain portion may be copolymerized, or after forming the main chain portion by copolymerization, a polymerizable reaction is performed by a modification reaction. A group may be introduced into the side chain moiety. When introduced into the side chain, any bond such as a urethane bond, an epoxy bond or an ester bond may be introduced as a polymerizable functional group. However, in order to impart flexibility to the resin, it is modified with urethane. Is preferred.
[0054]
Among the acrylic resins, a urethane-modified acrylic resin represented by the following formula 1 is preferable.
[0055]
[Chemical 1]

[0056]
(In the formula, Z represents a group for modifying the urethane-modified acrylic resin, and is preferably a bulky cyclic structure group. ¹ Each independently represent a hydrogen atom or a methyl group, R ² Is C ₁ ~ C ₁₆ X and Y each represents a linear or branched alkylene group. When the sum of l (el), m, n, o (o) and p is 100, l is 0 to 90, m is 0 to 80, n is 0 to 50, o + p is 10 to 80, p is an integer of 0-40. )
Z in the above formula 1 can be introduced to modify the urethane-modified acrylic resin. For example, an aromatic ring such as a phenyl group or a naphthyl group or a (meth) acrylate having a heteroaromatic ring such as pyridine. Long chain alkyl groups such as (meth) acryloyl-modified silicone oil or resin, vinyl-modified silicone oil or resin-containing silicone oil or resin having a polymerizable double bond group, lauryl (meth) acrylate, stearyl (meth) acrylate, etc. (Meth) acrylate having (meth) acrylate having a silicon-containing group such as γ- (meth) alkoxypropyltrimethoxysilane, 2- (perfluoro-7-methyloctyl) ethyl acrylate, heptadecafluorodecyl (meth) (Meth) acrylic having fluorine-containing groups such as acrylate , Isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, adamantyl (meth) acrylate, etc. It can introduce | transduce using vinyl monomers which have cyclic hydrophilic groups, such as (meth) acrylate, acryloyl morpholine, vinyl pyrrolidone, vinyl caprolactone, which have a high structure. As Z, one or more selected from the above can be introduced.
[0057]
As a preferable example of the urethane-modified acrylic resin of the above formula 1, 0 to 90 mol of methyl methacrylate, 0 to 80 mol of vinyl monomer having a bulky group, 0 to 50 mol of methacrylic acid, and 10 to 2-hydroxyethyl methacrylate An acrylic copolymer obtained by copolymerization with 80 moles, exemplified by a resin obtained by reacting a hydroxyl group present in the copolymer with methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate) can do.
[0058]
The methacryloyloxyethyl isocyanate need not react with all the hydroxyl groups present in the copolymer, and is at least 10 mol% or more of the hydroxyl groups of 2-hydroxyethyl methacrylate units in the copolymer, preferably 50 It is sufficient that at least mol% is reacted with methacryloyloxyethyl isocyanate. Instead of or in combination with the above 2-hydroxyethyl methacrylate, N-methylol (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. Monomers having a hydroxyl group can also be used.
[0059]
The urethane-modified acrylic resin is dissolved in a solvent capable of dissolving the copolymer, for example, a solvent such as toluene, ketone, cellosolve acetate, dimethyl sulfoxide, and the like, while stirring the solution, methacryloyloxyethyl. By dropping and reacting the isocyanate, the isocyanate group reacts with the hydroxyl group of the acrylic resin to form a urethane bond, and the methacryloyl group can be introduced into the resin through the urethane bond. The amount of methacryloyloxyethyl isocyanate used in this case is in the range of 0.1 to 5 moles, preferably 0.5 to 3 moles of isocyanate groups per mole of hydroxyl groups based on the ratio of hydroxyl groups to isocyanate groups of the acrylic resin. Amount. When methacryloyloxyethyl isocyanate having an equivalent amount or more than the hydroxyl group in the resin is used, the methacryloyloxyethyl isocyanate reacts with the carboxyl group in the resin to react with -CONH-CH. ₂ CH ₂ It is also possible to cause a − linkage.
[0060]
The above example shows that in the structural formula, all R ¹ And R ² Is a methyl group, and X and Y are ethylene groups, the present invention is not limited to these, and six R ¹ Each independently may be a hydrogen atom or a methyl group, and R ² Specific examples of are, for example, methyl group, ethyl group, n- or iso-propyl group, n-, iso- or tert-butyl group, substituted or unsubstituted phenyl group, substituted or unsubstituted benzyl group, and the like. Specific examples of X and Y include an ethylene group, a propylene group, a diethylene group, and a dipropylene group. Examples of the monomer having a group Z having a bulky cyclic structure include isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyloxy. A monomer having a bulky group of 6-membered ring, 6-membered ring or higher, such as ethyl (meth) acrylate, adamantyl (meth) acrylate and the like is preferable.
[0061]
Any urethane acrylate can be used as long as it has a urethane bond and a photopolymerizable (meth) acryloyl group in the molecule. Among urethane acrylates, an isocyanate compound having two or more isocyanate groups, a compound having two or more hydroxyl groups, and a compound having one or more hydroxyl groups and one or more (meth) acryloyl groups are reacted. Urethane acrylate obtained by reacting the obtained urethane acrylate or an isocyanate compound having two or more isocyanate groups with a compound having two or more hydroxyl groups and one or more (meth) acryloyl groups is preferred.
[0062]
Examples of the isocyanate compound having two or more isocyanate groups used for the synthesis of urethane acrylate include tetramethylene diisocyanate, hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and 4,4′-diphenylmethane diisocyanate. 1,5-naphthalene diisocyanate, 3,3-dimethyl-4,4-diphenylene isocyanate, isophorone diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 1, Examples include 3-bis (α, α-dimethylisocyanatomethyl) benzene, trimethylhexamethylene diisocyanate, and hydrogenated xylylene diisocyanate. These can be used alone or in admixture of two or more.
[0063]
Moreover, the isocyanate compound represented by the following formula 2a thru | or 2g can also be used.
[0064]
[Chemical 2]

[0065]
Examples of the compound having two or more hydroxyl groups used for the synthesis of urethane acrylate include 1,3-butanediol, 1,4-butanediol, trimethylolethane, trimethylolpropane, ditrimethylolethane, ditrimethylolpropane, and penta. Erythritol, dipentaerythritol, tripentaerythritol, diglycerol, glycerin, and many other polysiloxane polyols, poly (oxyalkylene) polyols, polyester polyols, polyether polyols, polyether polyester polyols, polyolefin polyols, poly (alkyl acrylates) A polyol, a polycarbonate polyol, etc. are mentioned.
[0066]
Examples of the compound having one or more hydroxyl groups and one or more (meth) acryloyl groups used for the synthesis of urethane acrylate include trimethylolpropane triacrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) ) Acrylate, 4-hydroxycyclohexyl (meth) acrylate, 5-hydroxycyclooctyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and isocyanuric Acid oxyethyl di (meth) acrylate may be mentioned.
[0067]
The urethane acrylate described above can be produced by reacting each of the above components under the reaction conditions described in JP-A-3-19842.
[0068]
As another urethane acrylate, an active energy ray-curable composition which is described in JP-A No. 2001-329031 and is tack-free even in an uncured state after being dried can be exemplified. This tack-free composition is a reaction product of an isocyanate compound having a melting point of 40 ° C. or higher and a (meth) acryl compound having a (meth) acryloyl group and capable of reacting with the isocyanate group, Contains at least 40 ° C. As the isocyanate compound having a melting point of 40 ° C. or more, a compound having an isocyanate group bonded to a non-aromatic hydrocarbon ring, particularly a trimer of isophorone diisocyanate, 3: 1 (molar ratio of isophorone diisocyanate and trimethylolpropane). ) Is preferred. The (meth) acrylic compound is preferably (meth) acrylic acid or (meth) acrylate having a hydroxyl group such as hydroxyethyl (meth) acrylate.
[0069]
Any polyester acrylate may be used as long as it has an ester bond and a photopolymerizable (meth) acryloyl group in the molecule. Among polyester acrylates, polyester acrylates obtained by further reacting a compound having two or more hydroxyl groups or a polyester compound synthesized from a cyclic ester compound and a polybasic acid with a compound having a (meth) acryloyl group are preferred.
[0070]
As the compound having two or more hydroxyl groups used for the synthesis of the polyester acrylate, the same compounds as those used for the synthesis of the urethane acrylate can be used.
[0071]
Examples of cyclic ester compounds used for the synthesis of polyester acrylate include lactone compounds such as ε-caprolactone, δ-valerolactone, γ-butyrolactone, and γ-valerolactone, derivatives thereof, and epoxy compounds such as the lactone compound and glycidyl methacrylate. And an addition reaction product.
[0072]
Examples of the polybasic acid used for the synthesis of the polyester acrylate include saturated polybasic acids such as adipic acid, succinic acid, and sebacic acid; unsaturated polybasic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid; phthalic acid And aromatic polybasic acids such as isophthalic acid, terephthalic acid and trimellitic acid.
[0073]
In this invention, the binder resin (A) which has a photopolymerizable functional group can be used individually by 1 type or in combination of 2 or more types as a binder resin. Moreover, in this invention, as long as the objective of this invention can be achieved, you may mix resin which does not have a photopolymerizable functional group. Examples of the resin having no photopolymerizable functional group include non-polymerizable transparent resins conventionally used for forming optical articles, such as polyacrylic acid, polymethacrylic acid, polyacrylate, polymethacrylate, Examples include polyolefin, polystyrene, polyamide, polyimide, polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral, and polycarbonate.
[0074]
In the present invention, after the stamper is pressed on the photocurable resin layer to form a fine concavo-convex pattern and the stamper is removed, the elasticity of the photocurable resin is in the middle of the process such as the exposure process and the vapor deposition process. In order to prevent the fine concavo-convex pattern from being rounded and out of shape, the photocurable resin composition can be dispersed in a colloidal form in a dilute solvent, and submicron-order inorganic ultrafine particles (B ) To improve creep properties and shape retention.
[0075]
Moreover, the release property of the photocurable resin composition is improved by blending the inorganic ultrafine particles (B) with the photocurable resin composition, and the stamper is removed when the stamper pressed against the photocurable resin layer is removed. Since the resin composition is less likely to adhere to the inner surface of the cavity, and the surface tack is reduced, the intermediate laminate before the press stamper is pressed on the base film is formed in a roll. There is also an advantage that blocking does not occur even if it is taken.
[0076]
In addition, the photocurable resin composition of the present invention is easy to relieve stress at the time of curing shrinkage by blending inorganic ultrafine particles (B), and solves various problems caused by distortion of curing shrinkage. I can do it. For example, when the photocurable resin composition is cured, the occurrence of resin cracks, curls, wrinkles, and the like due to curing shrinkage can be suppressed. Alternatively, when the layer of the photocurable resin composition contained in the transfer foil is cured, the foil portion is caused by the difference in shrinkage ratio between the adjacent layer, for example, the film substrate, the release layer, and the metal deposition layer. Generation of cracks, kinks, wrinkles, etc. can be suppressed.
[0077]
The photo-curable resin composition of the present invention has a high concentration state in which a solvent is not contained at all or only a small amount is contained, in addition to the case where it is prepared from the beginning to a concentration used for a coating operation using a diluent solvent. In some cases, the inorganic ultrafine particles (B) are finally colloidal in the diluting solvent. It is necessary to be able to be dispersed in a uniform form.
[0078]
Specific examples of the inorganic ultrafine particles include SiO ₂ TiO ₂ , ZrO ₂ , SnO ₂ , Al ₂ O _Three Among these, it is preferable to select and use a colloidal dispersible particle having a particle size on the order of submicron as described above. SiO ₂ It is preferable to use fine particles.
[0079]
It is preferable that a part of the metal oxide ultrafine particles is a metal hydroxide and has a structure in which water is adsorbed and hydrated, since it can be easily dispersed in a colloidal form in a diluting solvent. Further, when an organic solvent is used as the diluting solvent, the surface of the inorganic ultrafine particles can be easily dispersed in a colloidal form by subjecting it to a hydrophobic treatment. When the inorganic ultrafine particles are metal oxides, for example, hydrophobicity can be imparted by surface treatment with an organic low molecular component such as organic amine or organic carboxylic acid.
[0080]
The inorganic ultrafine particles (B) are of a so-called ultrafine particle size in order to ensure sufficient transparency in the coating film. Here, “ultrafine particles” are particles of submicron order, and generally mean particles having a particle diameter smaller than particles having a particle diameter of several μm to several hundred μm, which are generally called “fine particles”. ing. The specific size of the inorganic ultrafine particles (B) used in the present invention varies depending on the use and grade of the optical article to which the photocurable resin composition of the present invention is applied. Preferably has a primary particle diameter in the range of 1 nm to 300 nm. When the primary particle size is less than 1 nm, it is difficult to sufficiently improve the creep characteristics of the resin composition. On the other hand, when the primary particle size exceeds 300 nm, the transparency of the resin is impaired, and it is transparent depending on the use of the optical article. May be insufficient.
[0081]
The inorganic ultrafine particle (B) may have any shape, but a fine particle having a bulky shape, that is, a fine particle having a low density is preferable. By using bulky inorganic ultrafine particles, the blocking resistance, the creep characteristics and the shape retention of the uneven pattern of the photocurable resin composition are particularly improved.
[0082]
As the bulky shape, for example, an elongated shape, in particular, a shape such as a needle shape or a pearl necklace shape in which the extension exists in the same plane can be used. The pearl necklace shape is a shape in which spherical particles are connected in a bead shape or in series. When the inorganic ultrafine particles (B) are elongated, those having a thickness (diameter) of 1 to 100 nm and a length of 10 to 500 nm are preferably used, with a thickness of 1 to 20 nm and a length of 40 to 300 nm. A range is particularly preferred. If the length is less than 10 nm, there is no difference from the spherical silica, and if it exceeds 500 nm, the transparency is impaired.
[0083]
When an elongated shape is represented by an aspect ratio (ratio of length to thickness), the aspect ratio is preferably 3 or more. The aspect ratio may be calculated from the thickness and length measured directly with a microscope, or the particle diameter (D ₁ nm) and particle diameter measured by nitrogen gas adsorption method (D ₂ nm) ratio D ₁ / D ₂ May be calculated as the aspect ratio.
[0084]
Preferable specific examples of the elongated inorganic ultrafine particles are acicular silica having an aspect ratio of 3 or more and a thickness of 5 to 20 nm and a length of 40 to 300 nm when observed with an electron microscope, or a thickness of 10 Examples include pearl necklace-like silica having a length of ˜80 nm and a length of 50 to 500 nm. As the shape, acicular silica is particularly preferable, and sufficient creep characteristics and anti-blocking performance are exhibited with a small addition amount compared to a spherical one.
[0085]
The inorganic ultrafine particles (B) are preferably blended in a proportion of 0.1 to 70% by weight in the total solid content of the photocurable resin composition. In the case of fine particles having a shape, it is particularly preferable to blend in a proportion of 0.1 to 30% by weight. When the proportion of the inorganic ultrafine particles (B) is less than 0.1% by weight, it becomes difficult to sufficiently improve the creep characteristics of the resin composition, while the proportion of the inorganic ultrafine particles (B) exceeds 70% by weight. And the brittleness becomes remarkable, and it becomes difficult to obtain sufficient strength and surface hardness after exposure and curing. In addition, all the liquid components except a solvent are contained in solid content of a photocurable resin composition.
[0086]
You may mix | blend a mold release agent with the photocurable resin composition of this invention. By incorporating a release agent into the photocurable resin composition of the present invention, the press stamper is prevented from being removed when the press stamper is pressed against the photocurable resin layer and removed, and the press stamper is used continuously for a long period of time. (Repeated embossing).
[0087]
Examples of the release agent include conventionally known release agents such as solid waxes such as polyethylene wax, amide wax, and Teflon powder (Teflon is a registered trademark), fluorine-based and phosphate-based surfactants, and silicone. It can be used.
[0088]
Particularly preferred is a silicone-based mold release agent, and the release angle from the mold can be made very high by setting the contact angle of water to 90 ° or more. Examples of the silicone release agent include polysiloxane, modified silicone oil, polysiloxane containing trimethylsiloxysilicic acid, and silicone acrylic resin.
[0089]
The modified silicone oil is obtained by modifying the side chain and / or terminal of polysiloxane, for example, amino modification, epoxy modification, carboxyl modification, carbinol modification, (meth) acryl modification, mercapto modification, phenol modification, polyether modification. , Methylstyryl modification, alkyl modification, fluorine modification and the like. Two or more of the above-described modification methods can be performed on one polysiloxane molecule.
[0090]
As the silicone-based acrylic resin, (meth) acryloyl-modified silicone oil or acrylic resin copolymerized or grafted with a monomer containing silicon is used.
[0091]
The silicone release agent can be added alone or in combination of two or more.
[0092]
The release agent is preferably blended in a proportion of 0.1 to 30% by weight in the total solid content of the photocurable resin composition. When the ratio of the release agent is less than the above range, the release property between the press stamper and the photocurable resin layer tends to be insufficient. On the other hand, if the ratio of the release agent exceeds the above range, the surface of the coating film may be rough due to repelling during coating of the composition, or the substrate itself and the adjacent layer in the product, for example, the adhesion of the vapor deposition layer It is not preferable from the viewpoint of inhibiting the properties and causing film breakage or the like during transfer (film strength becomes too weak).
[0093]
In the photocurable resin composition of the present invention, a monofunctional or polyfunctional monomer or oligomer may be blended in order to reduce the viscosity of the composition, impart flexibility, or increase the crosslinking density.
[0094]
Monofunctional monomers include, for example, tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth) acrylate, vinylpyrrolidone, (meth) acryloyloxyethyl succinate, (meth) acryloyloxyethyl phthalate, isobornyl (meth) acrylate, cyclohexyl (Meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, etc. are mentioned.
[0095]
As a polyfunctional monomer or oligomer, for example, a bifunctional monomer and an oligomer include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6-hexanediol. As trifunctional monomer, oligomer, polymer such as di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, aliphatic tri (meth) acrylate, etc. As tetrafunctional monomer, oligomer Includes pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, aliphatic tetra (meth) acrylate, etc. The dipentaerythritol penta (meth) acrylate, other such dipentaerythritol hexa (meth) acrylate, polyester skeleton, a urethane skeleton, having a phosphazene skeleton (meth) acrylate.
[0096]
As monofunctional or polyfunctional monomers or oligomers, in addition to the above (meth) acrylates, styrene, vinyl toluene, chlorostyrene, bromostyrene, divinylbenzene, 1-vinylnaphthalene, 2-vinylnaphthalene, N-vinylpyrrolidone And allyl compounds such as diethylene glycol bisallyl carbonate, trimethylolpropane diallyl, diallyl phthalate, dimethacryl phthalate, and diallyl isophthalate can also be used.
[0097]
It is preferable to mix | blend a monomer or an oligomer in the ratio of 5 to 50 weight% in the solid content whole quantity of a photocurable resin composition. If the ratio of the monomer or oligomer is less than the above range, it cannot be said that the obtained cured resin layer has sufficient strength, heat resistance, scratch resistance, water resistance, chemical resistance, and adhesion to the substrate. If the amount of use exceeds the above range, the surface tack becomes high, causing blocking, and a part of the material remains on the plate (press stamper) at the time of duplicating a hologram, etc. Etc. are not preferable.
[0098]
In the photocurable resin composition of the present invention, an organic metal coupling agent may be blended in order to improve the heat resistance, strength, or adhesion to the metal vapor deposition layer of the surface structure having a fine concavo-convex pattern. . As the organometallic coupling agent, for example, various coupling agents such as a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent can be used.
[0099]
Examples of the silane coupling agent include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxy. Silane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl-γ-aminopropyltrimethoxysilane / hydrochloride, γ-glycidoxypropyltrimethoxy Silane, aminosilane, γ-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazane, γ-anilinopropyltrimethoxysilane , Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-chloropropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane , Methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane and the like.
[0100]
Examples of titanium coupling agents include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) Titanate, tetra (2,2-diallyloxymethyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl Titanate, isopropyl isostearoyl diacryl titanate, isop Pirutori (dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tri (N- aminoethyl-aminoethyl) titanate, dicumyl phenyloxy acetate titanate, diisostearoyl ethylene titanate.
[0101]
Examples of the zirconium coupling agent include tetra-n-propoxyzirconium, tetra-butoxyzirconium, zirconium tetraacetylacetonate, zirconium dibutoxybis (acetylacetonate), zirconium tributoxyethyl acetoacetate, zirconium butoxyacetylacetonate bis. (Ethyl acetoacetate) and the like.
[0102]
Examples of the aluminum coupling agent include aluminum isopropylate, monosec-butoxyaluminum diisopropylate, aluminum sec-butyrate, aluminum ethylate, ethylacetoacetate aluminum diisopropylate, aluminum tris (ethylacetoacetate), alkylacetate Acetate aluminum diisopropylate, aluminum monoacetylacetonate bis (ethyl acetoacetate), aluminum tris (acetylacetoacetate) and the like can be mentioned.
[0103]
The organometallic coupling agent is preferably blended at a ratio of 0.1 to 15% by weight in the total solid content of the photocurable resin composition. When the ratio of the organometallic coupling agent is less than the above range, the effect of imparting heat resistance, strength, and adhesion to the deposited layer is insufficient. On the other hand, when the ratio of the organometallic coupling agent exceeds the above range, the stability and film formability of the composition may be impaired.
[0104]
The photocurable resin composition of the present invention is blended with a photopolymerization initiator having activity with respect to the wavelength of the light source to be used, if necessary. As the photopolymerization initiator, a photopolymerization initiator that generates an appropriate active species according to the difference in the reaction mode of the binder or monomer (for example, radical polymerization or cationic polymerization) is used.
[0105]
Examples of the radical photopolymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin and α-phenylbenzoin; anthraquinone compounds such as anthraquinone and methylanthraquinone; benzyl Phenyl ketone compounds such as diacetylacetophenone and benzophenone; sulfide compounds such as diphenyl disulfide and tetramethylthiuram sulfide; α-chloromethylnaphthalene; anthracene; and halogenated hydrocarbons such as hexachlorobutadiene and pentachlorobutadiene .
[0106]
Examples of the photocation initiator include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, aromatic phosphonium salts, mixed ligand metal salts, and the like.
[0107]
Examples of photoanionic polymerization initiators include 1,10-diaminodecane, 4,4'-trimethylenedipiperidine, carbamates and derivatives thereof, cobalt-amine complexes, aminooxyiminos, ammonium borates, etc. can do.
[0108]
The photopolymerization initiator is preferably blended at a ratio of 0.5 to 10% by weight with respect to the total solid content of the photocurable resin composition. A photoinitiator may be used individually by 1 type and may be used in combination of 2 or more type.
[0109]
In order to improve the storage stability, a polymerization inhibitor may be blended in the photocurable resin composition of the present invention. As a polymerization inhibitor, for example, phenols such as hydroquinone, t-butylhydroquinone, catechol and hydroquinone monomethyl ether; quinones such as benzoquinone and diphenylbenzoquinone; phenothiazines; coppers and the like can be used. The polymerization inhibitor is preferably blended at a ratio of 0.1 to 10% by weight with respect to the total solid content of the photocurable resin composition.
[0110]
The photocurable resin composition according to the present invention is usually prepared in a coating solution state using a diluting solvent (main solvent) and used for forming a fine uneven pattern. Each material as described above is acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, benzene, toluene, xylene, chlorobenzene, tetrahydrofuran, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, ethyl acetate, 1,4- Preparing a coating solution as a photocurable resin composition according to the present invention by dissolving and dispersing in dioxane, 1,2-dichloroethane, dichloromethane, chloroform, methanol, ethanol, isopropanol, etc., or a mixed solvent thereof. Can do. The coating solution is usually adjusted so that the solid content concentration is about 10 to 50% by weight.
[0111]
(Fine uneven pattern forming method)
The photocurable resin composition according to the present invention is applied to the surface of a support such as a base film, and is dried as necessary to form a layer of fine uneven pattern forming material (fine uneven pattern forming layer). By producing a pattern receptor, embossing a stamper on the surface of the fine concavo-convex pattern forming layer of the concavo-convex pattern receiver, embossing, and reacting and curing the fine concavo-convex pattern forming layer by an appropriate method such as exposure or heating A fine concavo-convex pattern having an optical function can be formed and can be used as an optical article or a stamper.
[0112]
Before and after applying the fine concavo-convex pattern forming layer to the support, or before and after forming the fine concavo-convex pattern on the fine concavo-convex pattern formation layer, an anchor layer, a release layer, a metal thin film layer, an overcoat layer, if necessary Other layers such as a pressure sensitive or heat sensitive adhesive layer may be formed.
[0113]
The fine concavo-convex pattern forming layer may be cured in a state where the stamper is pressed, but may be exposed and heated after the stamper is removed. The latter method is excellent in continuous productivity because the stamper is removed before the fine uneven pattern forming layer is transferred to the curing process, and the removed stamper can be continuously used in the embossing process.
[0114]
Further, in the present invention, utilizing the fact that the fine concavo-convex pattern forming material is excellent in film formability and blocking resistance, an intermediate laminate having a fine concavo-convex pattern forming layer formed on a base film is wound into a roll. It can also be stored temporarily, transported to another location, rewound, stamped and cured.
[0115]
Further, the stamped and cured intermediate laminate is wound up into a roll and temporarily stored, transported to another location, rewound, and subjected to additional light or heat curing processes as necessary to be fully cured. Alternatively, a metal thin film, an overcoat layer, a pressure-sensitive or heat-sensitive adhesive layer, or the like can be formed on the fine concavo-convex pattern as necessary.
[0116]
Examples of the light used for curing the photocurable resin composition of the present invention include high energy ionizing radiation and ultraviolet rays. As the high-energy ionizing radiation source, for example, an electron beam accelerated by an accelerator such as a cockcroft accelerator, a handagraaf accelerator, a linear accelerator, a betatron, or a cyclotron is industrially most conveniently and economically used. However, radiation such as γ rays, X rays, α rays, neutron rays, proton rays emitted from radioisotopes or nuclear reactors can also be used. Examples of the ultraviolet ray source include an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a carbon arc lamp, and a solar lamp.
[0117]
A method for forming a micro uneven pattern using the photocurable resin composition of the present invention will be specifically described taking a relief hologram as an example. First, the photocurable resin composition is coated or impregnated on a base material such as a metal plate, paper, polyethylene terephthalate, and then the temperature at which the organic solvent contained in the composition is scattered, for example, 100 to 165 ° C. It guide | induces for about 0.1 to 1 minute in the set heating furnace, and it is made to dry and forms a photocurable resin layer on a base material. Then, desired hologram relief patterning (embossing) is performed on the photocurable resin layer using, for example, a press stamper.
[0118]
The embossing of the hologram pattern is performed, for example, by using a pair of embossing rollers consisting of a metal roll and a paper roll, which is mounted on the peripheral surface with a press stamper that has been continuously created from a master die made using a laser beam. Method, for example, 50-150 ° C., 10-50 kg / cm ² At a pressure of. In addition, as an embossing roller of the duplicating apparatus, a duplication hologram created from a master hologram by resin plate making and pasted on a cylinder can be used.
[0119]
For embossing, single-sided embossing is sufficient, but double-sided embossing may be used. In embossing, it is important to set the temperature of the embossing roll. From the viewpoint of reproducing the embossing shape, it is preferable to emboss at a relatively high temperature and relatively high pressure, but in order to prevent adhesion to the embossing plate. It is preferable to emboss at a relatively low pressure, which is exactly the opposite relationship. In addition, when considering the heat capacity that works effectively, the conveyance speed of the duplicated film is also important. In order to reduce the adhesion of the resin composition to the embossing roll, the selection of the release agent described above is also important.
[0120]
The photocurable resin layer is embossed and peeled off from the stamper, and then the resin layer is photocured by irradiation with ultraviolet rays or electron beams. Since the hologram is generally a transmission type, it is necessary to provide a reflection layer on the photocured resin layer. When a metal thin film that reflects light is used as the reflective layer, an opaque type hologram is obtained. When a reflective layer using a material that is transparent and has a refractive index difference from the hologram layer is provided, the transparent type is used. The reflective layer made of a metal thin film can be formed by a known method such as sublimation, vacuum deposition, sputtering, reactive sputtering, ion plating, or electroplating.
[0121]
For example, Cr, Ti, Fe, Co, Ni, Cu, Ag, Au, Ge, Al, Mg, Sb, Pb, Pd, Cd, Bi, Sn, Se, It consists of a metal such as In, Ga, Rb, etc., and oxides or nitrides thereof, or a combination of two or more kinds, and can be formed by a method such as chemical vapor deposition or physical vapor deposition. Among the metal thin films, Al, Cr, Ni, Ag, Au and the like are particularly preferable, and the film thickness is in the range of 1 to 10,000 nm, desirably 20 to 200 nm.
[0122]
As the thin film forming the transparent type hologram, any material can be used as long as it is light transmissive so as to exhibit the hologram effect. For example, a transparent material having a refractive index different from that of the resin of the hologram forming layer (photocurable resin layer) can be used. The refractive index in this case may be larger or smaller than the refractive index of the resin of the hologram forming layer, but the difference in refractive index is preferably 0.1 or more, more preferably 0.5 or more, and 1.0 The above is optimal. As a thin film forming a transparent hologram, there is a metallic transparent reflection film. As a transparent type reflective layer preferably used, titanium oxide (TiO 2) is used. ₂ ), Zinc sulfide (ZnS), and the like.
[0123]
In addition, for example, it is formed by coating a coating solution in which a high refractive index filler is dispersed, coating a colloidal solution of gold or silver, or forming a coating film by hydrolytic polycondensation reaction of an organometallic compound typified by a sol-gel reaction. It is also possible to use a high refractive index material film.
[0124]
The concavo-convex pattern receptor may be a final product to which a surface structure of a fine concavo-convex pattern is to be imparted, but may be an intermediate transfer medium. That is, in the present invention, a transfer foil is prepared by applying the photocurable resin composition to the first support to form a fine concavo-convex pattern forming layer, and the fine concavo-convex pattern forming layer of the transfer foil is finely formed. After the concave / convex pattern is formed and the fine concave / convex pattern forming layer is reaction-cured, it can be transferred onto the second support (final product). When the transfer foil is used, there is an advantage that it is not necessary to directly emboss the surface of the final product, or a large amount of fine uneven patterns can be formed in advance on the transfer foil. Forming a fine concavo-convex pattern by continuous transfer on the surface of an article that is difficult to directly emboss, such as a surface-shaped article, or on a support such as glass, plastic, or metal plate that cannot be rolled up Is also possible.
[0125]
In the present invention, the fine concavo-convex pattern transfer foil is composed of at least the photocurable resin composition of the present invention on the first support, and is peeled off from the first support and transferred to the second support. It is a laminate provided with a fine concavo-convex pattern forming layer in a state where it can be performed, and if necessary, in addition to the fine concavo-convex pattern forming layer, a release layer, a reflective layer, an adhesive layer or other layers One or more can be provided. For example, as shown in FIG. 1, the transfer foil 1 includes a peeling layer 3, a fine uneven pattern forming layer (photocurable resin composition layer) 4, a reflective layer (opaque reflective layer or fine uneven pattern forming layer) on a support 2. And a transparent layer having a different refractive index) 5 and an adhesive layer 6 may be sequentially laminated.
[0126]
As the support for producing the transfer foil, a flexible base film is usually used, and in terms of strength and heat resistance, polyethylene terephthalate, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, poly Plastic films such as vinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polystyrene, polymethyl methacrylate, nylon, polyethylene terephthalate, polyimide, polycarbonate, polynorbornene, and triacetyl cellulose are suitable, but not limited to plastic films In addition, it may not be flexible, and other materials such as a metal plate and paper may be used as the support. Further, when using an impregnated support such as paper, it may be formed in a state where the fine uneven pattern forming layer is impregnated in the support structure, and even in such a state, it is provided on the support. It is contained in one form of the formed fine uneven | corrugated pattern formation layer. In addition, a continuous film may be used as the base film in consideration of mass productivity of fine concavo-convex patterns such as holograms, but a sheet-like base film may be used.
[0127]
The release layer is provided on the lower layer of the fine concavo-convex pattern forming layer as necessary for the purpose of improving the peelability and tearability of the transfer foil, and fine concavo-convex from the transfer foil to some transfer surface (second support). This is the layer that becomes the outermost surface after being transferred together with the pattern forming layer. As the release layer, for example, only one kind selected from acrylic resin, polyester resin, polyvinyl chloride resin, cellulose resin, silicone resin, chlorinated rubber, casein, various surfactants, metal oxides, etc., alone or 2 More than seeds can be selected and mixed for use. Or what added said peeling material as an additive to the photocurable resin composition of this invention used for a fine uneven | corrugated pattern formation layer can also be used as a peeling layer.
[0128]
The reflective layer is provided on the fine concavo-convex pattern when, for example, a relief hologram is formed. The reflective layer may be either a transparent type or an opaque type, and can be formed of a metal thin film or a high refractive index film as described above.
[0129]
The adhesive layer is used for the purpose of improving the transferability of the fine concavo-convex pattern forming layer and the adhesion to the transfer target surface after transfer, or the surface of the fine concavo-convex pattern forming layer after embossing is used as a reflective film or the like. In the case of covering with a protective film, it is provided on the outermost surface of the fine concavo-convex pattern forming layer for the purpose of improving adhesion to these layers, and is a layer that becomes the lowermost layer after being transferred together with the fine concavo-convex pattern forming layer. .
[0130]
The adhesive layer can be appropriately selected from known heat-sensitive adhesive resins, pressure-sensitive adhesive resins, two-component curable adhesives, and photo-curable adhesives. Examples of the heat-sensitive adhesive resin include rubber systems such as polyisoprene rubber, polyisobutylene rubber, and styrene butadiene rubber; poly (meth) methyl acrylate, poly (meth) ethyl acrylate, poly (meth) acrylate, poly (Meth) acrylic acid esters such as butyl (meth) acrylate and poly (meth) acrylic acid-2-ethylhexyl; polyvinyl ethers such as polyisobutyl ether; polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, etc. Polyvinyl chloride; Polyamide such as polyacrylamide and polymethylol acrylamide; Vinyl chloride such as polyvinyl chloride; Polyvinyl butyral, Vinyl acetate / Octyl acrylate, Vinyl acetate / Butyl acrylate, Vinylidene chloride / Butyl acrylate, etc. Other vinyl type; polystyrene Aromatic vinyl; and polychlorinated olefins and the like, can be used alone or in combination of two or more select only one among these.
[0131]
An example of the procedure for producing the relief hologram transfer foil will be described below. In addition, the code | symbol used is for referring FIG. First, the base film 2 made of continuous plastic such as polyethylene terephthalate is fed out from the roll stock. The coating liquid of the release agent was applied onto the unrolled base film using a roll coater, and then set to a temperature at which the organic solvent contained in the coating liquid was scattered, for example, l00 to 165 ° C. The release layer 3 is formed by introducing the powder into a heating furnace for about 0.1 to 1 minute and drying it. On this peeling layer 3, the fine uneven | corrugated pattern formation material which consists of a photocurable resin composition is continuously apply | coated using a roll coater, Then, the temperature which the organic solvent contained in a composition scatters, for example, 100 The transfer foil 1 is prepared by forming the fine concavo-convex pattern forming layer 4 by being guided in a heating furnace set at ˜165 ° C. for about 0.1 to 1 minute and dried. As a coating machine other than the roll coater, for example, a gravure coater, a curtain coater, a flow coater, a lip coater, a doctor blade coater or the like can be used. The thickness of the fine uneven pattern forming layer is usually about 0.1 to 5.0 μm. The produced transfer foil 1 is wound up again to form a roll stock, which is stored or transported.
[0132]
Next, the transfer foil 1 is unwound from a roll stock, and a relief hologram stamper is pressed onto the surface of the fine concavo-convex pattern forming layer and embossed to form a fine concavo-convex pattern (not shown).
[0133]
The embossing of the hologram pattern is performed using, for example, a pair of embossing rollers composed of a metal roll and a paper roll with a stamper continuously created from a mother die made using laser light or an electron beam. In a usual manner, for example, hot roll temperature 100 to 200 ° C., press pressure 5 × 10 ^Three ~ 5x10 ⁶ Perform at Pa. When the hot roll temperature is higher than the above range, embossing can be performed at a high speed, but the damage to the base film is increased. Moreover, since it will take time to raise resin temperature when a hot roll temperature is made lower than the said range, an embossing process becomes slow. In addition, as an embossing roller of the duplicating apparatus, a duplication hologram created from a master hologram by resin plate making and pasted on a cylinder can be used.
[0134]
In this case as well, embossing can be performed on one side or both sides. The photocurable resin layer is embossed, peeled off from the stamper, and then irradiated with light to cure the resin layer. Examples of the light used for curing include high-energy ionizing radiation and ultraviolet rays as described above.
[0135]
After curing, if necessary, a reflective film such as a metal vapor deposition layer or a high refractive index material layer, or a transparent protective film for enhancing scratch resistance and contamination resistance may be formed on the fine concavo-convex pattern. Also good. When a layer such as a reflective film or a protective film is added on the fine concavo-convex pattern forming layer, an adhesive layer may be further added thereon.
[0136]
The transfer foil in which the fine concavo-convex pattern is formed and cured in this manner on the fine concavo-convex pattern forming layer is wound up again to form a roll stock, which is stored or transported.
[0137]
Next, the transfer foil on which the fine concavo-convex pattern is formed is drawn out from the roll stock, and the transfer target surface of the second support is placed on the fine concavo-convex pattern forming layer so as to face each other to transfer the hologram. The transfer foil is heated and pressed with a pressure roller or pressure plate from the base film side to melt and adhere, and then the transfer foil is peeled off so that the fine uneven pattern forming layer having the fine uneven pattern is the second support. It is transferred onto the body. The temperature and pressure at the time of transfer are factors related to the pressure method (roll type, stamping type) and pressure method, as well as the material and melting temperature of the support, the melting temperature of the heat-sensitive adhesive, and the heat-sensitive adhesive. Since the conditions vary greatly depending on factors such as the adhesion between the agent and the support material, the conditions are adjusted accordingly.
[0138]
In this way, an optical article comprising a cured resin layer made of a cured product of the photocurable resin composition and having a surface structure on which a fine uneven pattern of a relief hologram is formed is obtained.
[0139]
(Optical article)
According to the present invention, fine concavo-convex patterns made of a cured product of a photocurable resin composition and having various optical functions are obtained by the same method as that for the relief hologram or by modifying the method as necessary. An optical article provided with a cured resin layer having the formed surface structure can be produced.
[0140]
Conventionally, the concavo-convex pattern of a hologram replicated by embossing generally has a width (pitch) of about 500 to 1500 nm and a depth (depth / width) with respect to the width of about 1/3 or less. According to the present invention, it is needless to say that such a concavo-convex pattern can be duplicated, and a complex fine concavo-convex pattern having a higher optical function, for example, the width (pitch) of the concavo-convex pattern is about 200 nm or less, or Even when replicating a pattern having a depth (depth / width) of 1/2 or more with respect to the width, the fine uneven pattern forming material can be sufficiently poured into the cavity when the stamper is pressed, and the stamper is peeled off. Since the plate is not taken off and the pattern collapse after removing the stamper is hardly caused, it is possible to mass-produce fine uneven patterns with high accuracy by embossing.
[0141]
As an optical article produced by embossing using the fine concavo-convex pattern forming material of the present invention, (1) relief holograms and diffraction gratings used for security applications such as credit cards, ID cards, gift certificates, banknotes, etc. (2) Relief holograms and diffraction gratings used in graphic arts and design applications, such as amusement products such as so-called photo clubs or giveaways, packaging, postcards / sealings, novelty goods, etc. 3) An optical element that controls at least one of reflection, transmission, scattering, polarization, condensing, or interference of all rays and / or light of a specific wavelength, such as a reflector, a scattering plate, a polarizing plate, a lens, and wavelength selection Used as an optical element such as an element, an antireflection plate, a birefringent wavelength plate, an optical element having a sub-wavelength structure, Information recording element can be, for example, information recording holograms, optical cards, and the like can be employed not only as an optical disk or the like.
[0142]
The present invention can be applied to applications that control light more complicatedly or more precisely than relief holograms and diffraction gratings. However, when applied to relief holograms and diffraction gratings, the present invention is not limited to simply obtaining bright holograms. Relief holograms and diffraction gratings with simple designs can be formed.
[0143]
Furthermore, according to the present invention, a fine concavo-convex pattern can be formed with very high accuracy. Therefore, a complementary concavo-convex pattern can be duplicated using a fine concavo-convex pattern to be applied to an optical article as a mold and used as a stamper. Is possible.
[0144]
【Example】
Example 1
(1) Production of binder resin (A)
A 2-liter flask equipped with a condenser, dropping funnel and thermometer was charged with 40 g of toluene and 40 g of methyl ethyl ketone together with an azo polymerization initiator, 20.8 g of 2-hydroxymethyl methacrylate, 39.0 g of methyl methacrylate, and isobornyl methacrylate. A mixture of 45.0 g, 20 g of toluene, and 20 g of methyl ethyl ketone was reacted at a temperature of 100 ° C. for 8 hours while being dropped with a dropping funnel, and then cooled to room temperature. A mixed liquid of 23.4 g of 2-isocyanatoethyl methacrylate (manufactured by Showa Denko, Karenz MOI), 20 g of toluene and 20 g of methyl ethyl ketone was added thereto, and an addition reaction was performed using dibutyltin laurate as a catalyst. The disappearance of the isocyanate absorption peak was confirmed by IR analysis of the reaction product, and the reaction was completed. The obtained resin solution had a solid content of 38.2% by weight, a molecular weight of 30,000 in terms of polystyrene, and an introduction amount of carbon-carbon double bonds (C = C) of 12.5%.
[0145]
(2) Preparation of photocurable resin composition
The binder resin (A) and other components were mixed at the following blending ratio, diluted with methyl ethyl ketone to adjust the solid content concentration to 20% by weight, and the photocurable resin composition 1 of Example 1 was prepared.
[0146]
<Photocurable resin composition 1>
-Binder resin (A) (based on solid content): 70 parts by weight
・ Polyfunctional oligomer (dipentaerythritol hexaacrylate, trade name: KAYARAD DPHA, manufactured by Nippon Kayaku): 30 parts by weight
Release agent (amino-modified reactive silicone oil, trade name: KF-860, manufactured by Shin-Etsu Chemical Co., Ltd.): 5 parts by weight
Photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals): 5 parts by weight
Spherical colloidal silica (trade name: MEK-ST, manufactured by Nissan Chemical Industries) (solid content basis): 70 parts by weight
(Example 2)
The binder resin (A) produced in Example 1 and other components were mixed at the following blending ratio, diluted with methyl ethyl ketone to adjust the solid content concentration to 20% by weight, and the photocurable resin composition of Example 2 2 was prepared.
[0147]
<Photocurable resin composition 2>
-Binder resin (A) (based on solid content): 60 parts by weight
-Urethane acrylate (trade name: Purple light UV-3520TL, manufactured by Nippon Synthetic Chemical Industry) (solid content standard): 30 parts
・ Release agent (silicone resin, trade name: KF-7312, manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part
Photopolymerization initiator 1 (trade name: Irgacure 907, manufactured by Ciba Specialty Chemicals): 2 parts
Photopolymerization initiator 2 (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals): 3 parts
Spherical colloidal silica (trade name: MEK-ST, manufactured by Nissan Chemical Industries) (based on solid content): 90 parts
(Example 3)
The binder resin (A) produced in Example 1 and other components were mixed at the following blending ratio, diluted with methyl ethyl ketone to adjust the solid content concentration to 20% by weight, and the photocurable resin composition of Example 3 3 was prepared.
[0148]
<Photocurable resin composition 3>
-Binder resin (A) (based on solid content): 70 parts by weight
Polyester acrylate (trade name: Aronix M-9050, manufactured by Toa Gosei Chemical Industry): 20 parts by weight
Release agent (amino-modified silicone oil, trade name: KF-8012, manufactured by Shin-Etsu Chemical Co., Ltd.): 3 parts by weight
Monofunctional monomer (isobornyl methacrylate, trade name: SR-423, manufactured by Sartomer): 10 parts by weight
Photopolymerization initiator (trade name: Irgacure 2959, manufactured by Ciba Specialty Chemicals): 3 parts by weight
Aluminum coupling agent (trade name: ALCH-TR, manufactured by Kawaken Fine Chemical): 5 parts by weight
Spherical colloidal silica (trade name: MEK-ST, manufactured by Nissan Chemical Industries) (based on solid content): 80 parts by weight
(Example 4)
<Photocurable resin composition 4>
(1) Production of binder resin (B)
A 2-liter flask equipped with a condenser, dropping funnel and thermometer was charged with 40 g of toluene and 40 g of methyl ethyl ketone together with an azo polymerization initiator, 25.6 g of 2-hydroxymethyl methacrylate, 36.0 g of methyl methacrylate, and isobornyl methacrylate. A mixture of 109.6 g, 20 g of toluene, and 20 g of methyl ethyl ketone was allowed to react at a temperature of 100 to 110 ° C. for 8 hours while dropping through a dropping funnel over about 2 hours, and then cooled to room temperature.
[0149]
A mixed liquid of 28.8 g of 2-isocyanatoethyl methacrylate (manufactured by Showa Denko, Karenz MOI), 20 g of toluene and 20 g of methyl ethyl ketone was added thereto, and an addition reaction was performed using dibutyltin laurate as a catalyst. The disappearance of the isocyanate absorption peak was confirmed by IR analysis of the reaction product, and the reaction was completed. The obtained resin solution had a solid content of 37.0% by weight, a viscosity of 130 mPa (30 ° C.), a molecular weight of 60,000 in terms of polystyrene, and an introduction amount of carbon-carbon double bonds (C═C) of 12.8%. Met.
[0150]
(2) Preparation of photocurable resin composition
The binder resin (B) and other components were mixed at the following blending ratio, diluted with methyl ethyl ketone to adjust the solid content concentration to 20% by weight, and a photocurable resin composition 4 of Example 4 was prepared.
[0151]
<Photocurable resin composition 4>
-Binder resin (B) (based on solid content): 60 parts by weight
・ Polyfunctional oligomer (trade name: Purple light UV-1700B, manufactured by Nippon Synthetic Chemical Industry): 40 parts by weight
Release agent (silicone resin, trade name: X-21-3056, manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by weight
Photopolymerization initiator (trade name: Irgacure 907, manufactured by Ciba Specialty Chemicals) (based on solid content): 5 parts by weight
Spherical colloidal silica (trade name: MEK-ST, manufactured by Nissan Chemical Industries) (solid content basis): 60 parts by weight
(Example 5)
The binder resin (B) produced in Example 4 and other components were mixed at the following blending ratio, diluted with methyl ethyl ketone to adjust the solid content concentration to 20% by weight, and the photocurable resin composition of Example 5 was used. 5 was prepared.
[0152]
<Photocurable resin composition 5>
-Binder resin (B) (based on solid content): 70 parts by weight
・ Release agent (silicone resin, trade name: KF-7312, manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by weight
Polyfunctional oligomer (trade name: SR-399, manufactured by Sartomer): 10 parts by weight
Aluminum coupling agent (trade name: ALCH-TR, manufactured by Kawaken Fine Chemical): 5 parts by weight
Photopolymerization initiator (trade name: Irgacure 907, manufactured by Ciba Specialty Chemicals): 5 parts by weight
・ Spherical colloidal silica (trade name: MEK-ST, manufactured by Nissan Chemical Industries) (based on solid content): 30 parts by weight
(Example 6)
The binder resin (B) produced in Example 4 and other components were mixed at the following blending ratio, diluted with methyl ethyl ketone to adjust the solid content concentration to 20% by weight, and the photocurable resin composition of Example 6 was used. 6 was prepared.
[0153]
<Photocurable resin composition 6>
-Binder resin (B) (based on solid content): 30 parts by weight
Non-polymerizable binder resin (trade name: Dianal BR-85, manufactured by Mitsubishi Rayon): 30 parts by weight
・ Polyfunctional monomer (dipentaerythritol hexaacrylate, trade name: KAYARAD DPHA, manufactured by Nippon Kayaku): 30 parts by weight
Release agent (amino-modified silicone oil, trade name: KF-8012, manufactured by Shin-Etsu Chemical Co., Ltd.): 10 parts by weight
Photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals): 5 parts by weight
Spherical colloidal silica (trade name: MEK-ST, manufactured by Nissan Chemical Industries) (solid content basis): 60 parts by weight
(Example 7)
In Example 1, instead of 70 parts by weight of spherical colloidal silica, Example 1 is used except that 10 parts by weight of acicular colloidal silica (trade name: IPA-ST-UP, manufactured by Nissan Chemical Industries) (based on solid content) is used. Similarly, a photocurable resin composition 7 of Example 7 was prepared.
[0154]
(Example 8)
In Example 2, instead of 90 parts by weight of spherical colloidal silica, Example 2 is used except that 15 parts by weight of acicular colloidal silica (trade name: IPA-ST-UP, manufactured by Nissan Chemical Industries) (based on solid content) is used. Similarly, a photocurable resin composition 8 of Example 8 was prepared.
[0155]
Example 9
In Example 3, instead of 80 parts by weight of spherical colloidal silica, Example 3 except that 10 parts by weight of acicular colloidal silica (trade name: IPA-ST-UP, manufactured by Nissan Chemical Industries) (based on solid content) is used. Similarly, a photocurable resin composition 9 of Example 9 was prepared.
[0156]
(Example 10)
In Example 4, instead of 60 parts by weight of spherical colloidal silica, Example 4 is used except that 10 parts by weight of acicular colloidal silica (trade name: IPA-ST-UP, manufactured by Nissan Chemical Industries, Ltd.) (based on solid content) is used. Similarly, the photocurable resin composition 10 of Example 10 was prepared.
[0157]
(Example 11)
In Example 5, instead of 30 parts by weight of spherical colloidal silica, Example 5 is used except that 5 parts by weight of acicular colloidal silica (trade name: IPA-ST-UP, manufactured by Nissan Chemical Industries) (based on solid content) is used. Similarly, the photocurable resin composition 11 of Example 11 was prepared.
[0158]
(Example 12)
In Example 6, instead of 60 parts by weight of spherical colloidal silica, Example 6 is used except that 10 parts by weight of acicular colloidal silica (trade name: IPA-ST-UP, manufactured by Nissan Chemical Industries) (based on solid content) is used. Similarly, the photocurable resin composition 12 of Example 12 was prepared.
[0159]
(Comparative Examples 1 to 6)
Comparative Examples 1 to 6 were prepared in the same manner as in Examples 1 to 6 except that no colloidal silica was added.
[0160]
(Example 13)
(1) Creation of label type fine uneven pattern sheet
The photo-curable resin compositions of the above Examples and Comparative Examples were each coated with a gravure coater on the easy-adhesion treated surface of a 50 μm thick single-sided easy-adhesive treated polyethylene terephthalate film (Diafoil T600E, manufactured by Diafoil Hoechst). And dried at 100 ° C. to evaporate the solvent, resulting in a dry film thickness of 2 g / m ² A photosensitive film for duplication was formed.
[0161]
Next, a press stamper made from a master die made using a laser beam is placed on the embossing roller of the duplicating machine, and the photosensitive film for duplication is set on the paper feeding side of the duplicating machine, and heated at 150 ° C. Thus, a fine uneven pattern was formed. Next, the photosensitive film for duplication was photocured by irradiating with ultraviolet rays generated from a mercury lamp, and subsequently aluminum was deposited by vacuum deposition to obtain a reflective fine uneven pattern sheet.
[0162]
(2) Evaluation of label type fine uneven pattern sheet
The following evaluation was performed about the intermediate product obtained in the middle of preparation of a label type fine concavo-convex pattern sheet, and the finished product of a label type fine concavo-convex pattern sheet. The results are shown in Table 1.
[0163]
<Evaluation items>
(1) Blocking resistance
The photosensitive film for duplication before embossing was stored at room temperature and in a light-shielded state for 1 month in a wound state, and the surface blocking state was visually observed and evaluated according to the following criteria.
A: Good
○: A trace of the resin dissolved on the surface remains, but there is no sticking
X: The film is stuck and the resin on the surface is melted and rough.
[0164]
(2) Shapeability
The fine concavo-convex patterns embossed by a press stamper were compared with observation images using an AFM (atomic force microscope) and evaluated according to the following criteria.
A: The shape is accurately reproduced even if the heat press time by the stamper is reduced to ½.
○: Good, that is, the shape of the press stamper is accurately reproduced.
X: Defect, that is, “sag” in the shape without being accurately reproduced, inaccurate and rounded.
[0165]
(3) Shape retention
The fine concavo-convex pattern embossed by a press stamper was exposed to ultraviolet rays, and the final product was compared through an AFM observation image through a subsequent process, and evaluated according to the following criteria.
○: Good, that is, the shape of the press stamper is accurately reproduced even after the subsequent process.
X: Defect, that is, “sag” is seen in the shape without being accurately reproduced, and the shape is rounded and deformed.
[0166]
(4) Heat resistance
The final product was observed for 2 hours in an environment of 100 ° C. and observed for evaluation according to the following criteria.
○: Good, that is, there was no abnormality.
X: Defects, that is, abnormalities such as discoloration and deformation occurred.
[0167]
(5) Vapor deposition suitability (cellophane tape cross-cut peel test)
After depositing an aluminum layer on the surface having fine concavo-convex patterns by vacuum vapor deposition, scratches of 11 vertical x 11 horizontal were attached to the vapor deposition film with a cutter to provide 100 grids. The cellophane tape was strongly adhered from above, and then peeled off at a stretch. The number of cells remaining on the film surface was counted, the adhesion was evaluated, and the following criteria were evaluated.
○: Good, that is, the number of remaining squares is 95 or more.
X: Defect, that is, the number of remaining squares is 94 or less.
[0168]
[Table 1]

[0169]
(Example 14)
(1) Creation of fine concavo-convex pattern transfer foil sheet
A 25 μm thick polyethylene terephthalate film (Lumirror T60, manufactured by Toray Industries, Inc.) was coated with a peelable varnish (trade name: Haklinis 45-3, manufactured by Showa Ink Industries, Ltd.) by a gravure coating method and dried at 100 ° C. The solvent is evaporated and the dry film thickness is 1 g / m. ² A release layer was formed. On the surface of the release layer, each of the photocurable resin compositions of Examples and Comparative Examples was applied with a gravure coater, dried at 100 ° C. to volatilize the solvent, and the dry film thickness was 2 g / m. ² A photosensitive film for duplication was formed.
[0170]
Next, a press stamper made from a master die made using a laser beam is placed on the embossing roller of the duplicating machine, and the photosensitive film for duplication is set on the paper feeding side of the duplicating machine, and heated at 150 ° C. Thus, a fine uneven pattern was formed. Next, the photosensitive film for duplication was photocured by irradiating with ultraviolet rays generated from a mercury lamp, and subsequently, aluminum was deposited by a vacuum deposition method to produce a reflective relief hologram. On this surface, an acrylic heat-sensitive adhesive was applied by gravure coating, dried at 100 ° C. to volatilize the solvent, and the dry film thickness was 1 g / m. ² An adhesive layer was formed to obtain a fine concavo-convex pattern transfer foil sheet. From this transfer foil sheet, relief holograms can be transferred to the surfaces of various articles, and printed materials and displays that display stereoscopic images can be created.
[0171]
(2) Evaluation of fine concavo-convex pattern transfer foil sheet
The following evaluation was performed about the intermediate product obtained in the middle of preparation of a fine unevenness pattern transfer foil sheet, and the finished product of a fine unevenness pattern transfer foil sheet. The results are shown in Table 2.
[0172]
<Evaluation items>
(1) Blocking resistance
The same operation as in Example 13 was performed. That is, the photosensitive film for duplication before embossing was stored at room temperature in a rolled-up state for 1 month in a light-shielded state, and the surface blocking state was visually observed and evaluated according to the following criteria.
A: Good
○: A trace of the resin dissolved on the surface remains, but there is no sticking
X: The film is stuck and the resin on the surface is melted and rough.
[0173]
(2) Shapeability
The same operation as in Example 13 was performed. That is, the fine concavo-convex patterns embossed by a press stamper were compared with observation images by an AFM (atomic force microscope) and evaluated according to the following criteria.
A: The shape is accurately reproduced even if the heat press time by the stamper is reduced to ½.
○: Good, that is, the shape of the press stamper is accurately reproduced.
X: Defect, that is, “sag” in the shape without being accurately reproduced, inaccurate and rounded.
[0174]
(3) Shape retention
The same operation as in Example 13 was performed. That is, the fine concavo-convex pattern embossed by a press stamper was exposed to ultraviolet rays, and the final product obtained through the subsequent process was compared with an AFM observation image and evaluated according to the following criteria.
○: Good, that is, the shape of the press stamper is accurately reproduced even after the subsequent process.
X: Defect, that is, “sag” is seen in the shape without being accurately reproduced, and the shape is rounded and deformed.
[0175]
(4) Heat resistance
The same operation as in Example 13 was performed. That is, the state after leaving the final product in a 100 ° C. environment for 2 hours was observed and evaluated according to the following criteria.
○: Good, that is, there was no abnormality.
X: Defects, that is, abnormalities such as discoloration and deformation occurred.
[0176]
(5) Scratch resistance
When the surface of the processed product was rubbed 10 times with # 0000 steel wool, the surface was observed and evaluated according to the following criteria.
○: Good, that is, there was no change on the surface.
X: Defect, that is, the surface was damaged.
[0177]
(6) Transfer foil suitability
Foil in which an aluminum layer is deposited on the surface with fine unevenness by vacuum deposition, and then an acrylic adhesive for heat sealing is applied onto a PVC card and used as a transfer foil. Cutability was evaluated according to the following criteria.
○: Good, ie, transferred in good shape to the transfer mold.
X: Defect, that is, foil residue or chipping occurred.
[0178]
[Table 2]

[0179]
【The invention's effect】
As described above, since the inorganic ultrafine particles are blended in the photocurable resin composition according to the present invention, a press stamper is pressed against the photocurable resin layer made of the photocurable resin composition. In the middle of processes such as the exposure process and vapor deposition process after shaping the fine concavo-convex pattern and removing the stamper, it is possible to prevent the fine concavo-convex pattern from being rounded and out of shape due to the elasticity of the resin composition itself. it can.
[0180]
Therefore, the press stamper can be continuously used in the stamping process without bringing it into the exposure process, and the optical article can be efficiently and continuously produced.
[0181]
In addition, the photocurable resin composition of the present invention is excellent in blocking resistance due to the incorporation of inorganic ultrafine particles, and an intermediate laminate having a photocurable resin layer formed on a base film is rolled. It is also possible to take up and store temporarily and transport it to another place for stamping.
[0182]
Furthermore, when using acrylic resin, urethane acrylate, polyester acrylate, or a mixture of any combination thereof as the main binder of the photocurable resin composition according to the present invention, transparency, strength, Excellent scratch resistance, heat resistance, water resistance, chemical resistance, adhesion to substrate, flexibility, followability to bending and expansion / contraction of substrate, and sufficiently satisfy general performance required for optical articles In addition, the film has sufficient film forming property, flexibility and creep property to shape the uneven pattern with the stamper, and the fine uneven pattern can be replicated very accurately by combining with the ultrafine inorganic particles. Therefore, the surface structure of an optical article with good performance can be continuously produced accurately and at high speed by the stamping method.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an example of a fine uneven pattern transfer foil.
[Explanation of symbols]
1. Transfer foil
2 ... Support
3 ... release layer
4 ... Fine uneven pattern forming layer
5 ... Reflective layer
6 ... Adhesive layer

Claims (18)

The essential component (A) is a binder resin having a photopolymerizable functional group, and (B) is an elongated shape having a thickness of 1 to 100 nm, a length of 10 to 500 nm, and an aspect ratio of 3 or more, and is prepared as a coating liquid. Characterized in that it can be dispersed in a colloidal form in a diluting solvent and contains inorganic ultrafine particles of submicron order, and is used to form a fine uneven pattern of an optical article , Curable resin composition. 2. The photocurable resin composition according to claim 1 , wherein the content of the inorganic ultrafine particles (B) is in the range of 0.1 to 70% by weight with respect to the total solid content. The inorganic ultrafine particles (B) is characterized by an inorganic ultrafine particles having a hydrophobic surface treated, the photocurable resin composition according to claim 1 or 2. Polystyrene equivalent molecular weight of the binder resin, characterized in that in the range of 2,000 to 500,000, the photocurable resin composition according to any one of claims 1 to 3. The photocuring according to any one of claims 1 to 4 , wherein the binder resin is one or more selected from the group consisting of an acrylic resin, a urethane acrylate resin, and a polyester acrylate resin. Resin composition. Characterized in that it contains a monomer or oligomer having a photopolymerizable functional group, photo-curable resin composition according to any one of claims 1 to 5. The photocurable resin composition according to any one of claims 1 to 6 , further comprising a release agent. The photocurable resin composition according to any one of claims 1 to 7 , further comprising an organic metal coupling agent. 9. A fine concavo-convex pattern transfer foil, wherein a fine concavo-convex pattern forming layer comprising at least the photocurable resin composition according to any one of claims 1 to 8 is provided on a support so as to be transferable. . On the support, at least a release layer, a fine concavo-convex pattern forming layer, an opaque reflective layer, or a reflective layer selected from a transparent layer having a refractive index different from that of the fine concavo-convex pattern formation layer, and an adhesive layer are sequentially laminated. The fine uneven | corrugated pattern transfer foil of Claim 9 characterized by the above-mentioned. An optical article comprising a surface structure made of a cured product of the photocurable resin composition according to any one of claims 1 to 8 and having a fine uneven pattern formed thereon. The optical article according to claim 11 , wherein the fine uneven pattern is a relief hologram or a diffraction grating. The optical article according to claim 11 , wherein the fine concavo-convex pattern is an optical element that controls at least one of reflection, transmission, scattering, polarization, light collection, and interference of all light rays and / or light having a specific wavelength. The optical article according to claim 11 , wherein the fine uneven pattern has a structure for recording information. A stamper comprising a surface structure formed of a cured product of the photocurable resin composition according to any one of claims 1 to 8 and having a pattern complementary to a fine uneven pattern of an optical article. . A concavo-convex pattern receptor provided with a fine concavo-convex pattern forming layer comprising at least the photocurable resin composition according to any one of claims 1 to 8 on a support is prepared, and a stamper is pressed against the surface to form concavo-convex After forming a pattern, the said fine uneven | corrugated pattern formation layer is reaction-hardened, The fine uneven | corrugated pattern formation method characterized by the above-mentioned. The fine uneven | corrugated pattern formation method of Claim 16 which makes the said fine uneven | corrugated pattern formation layer react harden | cure after removing a stamper from the said fine uneven | corrugated pattern formation layer. The method for forming a fine concavo-convex pattern according to claim 16 or 17 , wherein the fine concavo-convex pattern forming layer reacted and cured on the support is transferred onto the second support.

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