JP4079748B2 - Liquid crystal laminate and liquid crystal laminate continuum - Google Patents

Description

（表１の注）Ｃは結晶性固体、Ｓはスメクチック相、ＳｃはキラルスメクチックＣ相、Ｃｈはコレステリック相、Ｎ^*はキラルネマチック相、Ｉは等方性液体を表す。
【００１１】
また、表２に示す単独でネマチック相を示す化合物に、表３に示すキラル化合物を加えてもキラルネマチック相を形成する（以下、コレステリック相、キラルネマチック相の区別をせずに、コレステリック相と総称する）。
【００１２】
【表２】

（表２の注）Ｃは結晶性固体、Ｎはネマチック相、Ｉは等方性液体を表す。
【００１３】
【表３】

（表３の注）ネマチック相を示す液晶にキラル分子を添加すると、キラルネマチック相（Ｎ^*）が得られる。この場合、その混合液晶のピッチの逆数１／Ｐは、キラル分子のモル濃度Ｘ_Bが小さい領域では、Ｘ_Bに比例する。それゆえ、１／ＰＸ_Bのことを、キラルのねじり力という。
【００１４】
この発明にかかる液晶層１４は、コレステリック相が固定されたものであり、その固定の方法としては、たとえば、液晶分子の両末端にアクリル基を有さしめ、これを基材１２に塗工し、この塗工物をコレステリック相を形成し得る温度まで加熱し、コレステリック相を形成し、紫外線照射をすることにより、ＵＶ架橋してコレステリック相を固定する。
そのため、温度等、環境が変化しても、コレステリック相は安定して存在する。
あるいは、液晶分子と一般的に用いられるバインダーの混合物を塗工し、コレステリック相を形成し得る温度に加熱し、コレステリック相を形成し、乾燥し、バインダーでコレステリック相を固定してもよい。
【００１５】
液晶層形成用塗液は、溶剤系でも非溶剤系でもよい。
溶剤系では、ＭＥＫ，ＭＩＢＫ等のケトン類、トルエン、酢酸エチル等が好ましい。また、固形分濃度は、特に制限はないが、２５〜６７％が好ましい。２５％を下回ると、画線を鮮明に形成できなくなるおそれがあり、乾燥に要する時間が長くなる。６７％を超えると塗液を加熱しないと固体が析出するおそれがある。特に好ましい濃度範囲は、５０〜６５％である。塗液からの溶剤の蒸発等による固体の析出のおそれをなくすために、塗液を加熱しながら塗工することも行われる。
非溶剤系では、塗工組成物をコレステリック相を形成する温度以上、好ましくはコレステリック相を形成する温度領域の温度に加熱しながら塗工を行う。
溶剤系でも、非溶剤系でも、塗工物に形成されているコレステリック相の固定を行うため、コレステリック相を形成する温度範囲に液晶層形成用塗工物を保ったまま、架橋等を行う。これによって、コレステリック相は、温度環境等が変わっても、たとえば常温においても安定的に維持される。
【００１６】
コレステリック相からなる液晶層１４は、光輝性を示し、見る方向によって連続的に色調が変化する。たとえば、上から垂直に見たときにはグリーンに見え、水平に近い方向に見たときにはブルーに見えるといった如くである。
このコレステリック相を示す液晶層１４は、広いスペクトル領域で入射する光の一部の波長領域のみが反射し、これ以外の領域の波長は、すべて透過するという特徴を有する。
【００１７】
この液晶層１４は、基材１２の裏面に全面にわたって形成されている。
なお、螺旋のピッチＰ（図２図示）が大きくなると、長波長側の色が現われ、螺旋のピッチＰが小さくなると、短波長側の色が現われる。このピッチを変えるには、キラル化合物を添加した系においては、キラル化合物の添加量を変更すればよい。
【００１８】
背景層１６は、墨インキや赤・青等の着色インキ等を、液晶層１４の裏面に全面にわたって印刷・塗工することによって形成される。背景層１６は、液晶層１４の光輝性を際立たせるために形成されたもので、液晶層１４を覆うように基材１２の裏面全面にわたって形成されている。特に、背景層１６としては、墨インキ等で形成された黒色が、液晶層１４の光輝性を際立たせるために優れている。
また、背景層１６の色彩によって、液晶層１４の目視での色調が変化するので、背景層１６を形成するインキの組成や色が重要である。たとえば、背景層１６の色が黒のときは、液晶層１４を目視すると、グリーンからブルーの光輝性を示すのに対し、背景層１６が赤のときは、液晶層１４を目視すると、オレンジから紫の光輝性を示し、また、背景層１６が白に近い着色のときには、液晶層１４は、乳白色またはパール調を示す。
したがって、背景層１６を形成する色を２以上に区分けして形成すると、液晶層１４を目視したとき、背景層１６の色彩の変化に対応した彩り鮮やかな液晶積層体１０となる。
【００１９】
熱接着性接着剤層１８は、ＥＶＡ系樹脂、アイオノマー樹脂、アクリル系樹脂などのうち１または複数の樹脂を含む熱接着性接着剤を背景層１６の裏面に塗布して形成されている。
これらの樹脂を含む熱接着性接着剤は、エマルジョンとして溶剤に溶解するかあるいは熱で溶融する等して、背景層１６の裏面に塗工される。
その塗布の厚みは、１〜２０μｍが好ましく、より好ましくは１〜７μｍである。
【００２０】
前記液晶積層体１０は、たとえば、図３（Ａ）に示すように、被着体Ａに熱接着性接着剤層１８面を接合させ、適宜な文字や模様などの画線の凸版を備えた箔押板Ｂを加熱して液晶層１４との表面側より押し当て（圧接する）、熱接着性接着剤層１８を活性化させ、商品や商品等の保証書などのような被着体Ａに溶着（ホットスタンピング）される。そして、図３（Ｂ）に示すように、溶着によって液晶層１４と基材１２とが剥離し、基材１２のない液晶層１４、背景層１６、熱接着性接着剤層１８からなる転写体が商品や保証書などの被着体Ａに貼着する。
液晶積層体１０を被着体Ａにホットスタンプしたとき、液晶積層体１０の基材１２と液晶層１４が剥離して、基材１２を取り除くことができるようにするために、たとえば、次のような構成とする。
基材１２と液晶層１４の接着強度を、他の層間、すなわち液晶層１４と背景層１６間および背景層１６と熱接着性接着剤層１８間の接着強度、および各層（液晶層１４、背景層１６、熱接着性接着剤層１８）の凝集破壊強度より弱く構成する。その方法としては、たとえば、液晶層形成用塗液にバインダーを全く用いずまたはバインダーの量を抑制して、基材１２と液晶層１４との接着強度を調整する方法がある。
また、液晶積層体１０を被着体Ａから剥がそうとしても、液晶積層体１０から基材１２が取り除かれているので、液晶積層体１０を破壊せずに剥がして、他の品物に液晶積層体１０を貼り替え、偽物を真正品と見せかけることは極めてむずかしい。さらに、液晶積層体１０を被着体Ａから剥がそうとしたとき、液晶積層体１０が破壊して、他の偽物の品物に液晶積層体１０を貼り替え、偽物を真正品と見せかけることができなくなるようにするために、たとえば次のような構成とすると一層効果的である。
背景層１６と液晶層１４との凝集破壊強度を異ならしめたり、液晶層１４と背景層１６と熱接着性接着剤層１８間の接着強度を異ならしめるように構成するとよい。
【００２１】
【実施例１】
基材として、特に表面処理が施されていない、幅１６０ｍｍ、厚さ５０μｍのＰＥＴフィルム（株式会社東洋紡製Ｅ−５０００）を準備し、別途、基材の裏面に塗工されて液晶層を構成する塗液を準備する。
液晶層形成用塗液としては、次の混合塗液を用いる。
両末端にアクリル基を有するネマチック液晶（ＢＡＳＦ社のPaliocolor LC242）・・・５５．３重量％
キラル化合物（ＢＡＳＦ社のPaliocolor LC756）・・・２．９重量％
紫外線重合開始剤（チバスペシャリティ−ケミカルズ社のIrgacure 369）・・・１．８重量％
溶媒としてのメチルエチルケトン（ＭＥＫ）・・・４０．０重量％
この液晶形成用塗液をもって、グラビア版により、乾燥後の厚さが３μｍとなるように塗工して、乾燥ゾーン（１１０〜１２０℃）を１５秒間通過させて乾燥させ、コレステリック相を形成する。その後直ちに、紫外線照射をして、紫外線ＵＶ硬化を行い、コレステリック相を固定する。ネマチック液晶を形成する温度は、５９℃以上１２０〜１２４℃以下である。
これによって、基材上に、安定的なコレステリック相からなる液晶層を形成する（液晶層を形成するステップ）。
次に、背景層を形成するための墨インキ塗液（東洋インキ製造株式会社製ＰＡＮＮ ＥＣＯ）を準備し、この墨インキ塗液を基材の裏面に、液晶層を覆うように、グラビア版により乾燥後の平均厚さ３μｍとなるよう塗工する。その後、乾燥ゾーン（７０〜８０℃）を３秒間通過させて、墨インキ塗液を乾燥する。
而して、液晶層を覆う背景層が基材の裏面に形成される（背景層を形成するステップ）。
【００２２】
中央理科工業株式会社製熱接着性接着剤（ＥＶＡ系樹脂、ＨＡ−１１００）の固形分濃度４５％のエマルジョンをワイヤーバー（Ｎｏ．５）で塗布し、５０℃で２分間熱風乾燥機で乾燥させ熱接着性接着剤層を形成する（ドライ塗布厚は、２μｍである）。
【００２３】
この実施例の液晶積層体は、被着体（ポリプロピレンからなる）に熱接着性接着剤層を接合し、１２０℃に加熱された金属製凸版を数秒間圧着させて基材を液晶層表面より取り除き、版の凸部により圧着された部分の液晶側から見ると、見る方向によって、緑ないし青紫に変化する鮮やかな光輝性を示した。
また、この実施例においては、液晶層を構成する液晶層形成用塗液に、バインダーを全く用いずに液晶層を形成しているので、基材と液晶層の界面の接着強度を、他の層間の接着強度や各層の凝集破壊強度より弱くなっているために、被着体（ポリプロピレンからなる）に貼り付けし、基材と液晶層との間で剥離し、被着体に他の層が破壊することなく貼着することをできた。
この実施例においては、ＵＶ架橋（硬化）してあるために、箔押しするとき（通常１００〜１５０℃程度の温度で行う）、１２０〜１２４℃以上に加熱しても、液晶層１４がそのままの状態を保つ。もっとも、架橋していなくても、たとえば箔押しするとその温度を１１０℃位とすれば、液晶層１４は液体相にならず、液晶相のまま保たれる。
また、バインダーを用いて液晶層１４を固定した場合、少なくとも、バインダーが流動化する温度までは液晶相は保たれる。
なお、この実施例においては、液晶層１４と背景層１６との界面の接着強度を背景層１６と熱接着性接着剤層１８間の界面の接着強度や各層の凝集破壊強度を異ならしめて設計することができる。
たとえば、次のようにするとよい。
液晶層１４に、バインダーが含まれないか少ない場合には、液晶層１４は基材１２に付着しているだけかあるいは弱く接着している。
液晶層１４上に、印刷等によって背景層１６が形成されるが、背景層１６形成時に、墨インキ等の背景層１６成分が液晶層１４の微細な凹み等に入り込むので、液晶層１４と背景層１６の接着強度は、液晶層１４と基材１２との間の接着強度より強くなり、背景層１６と熱接着性接着剤層１８との間の接着強度より弱くなると推定される。
【００２４】
図４は、この発明の液晶積層体の別の実施の形態である断面図解図である。
この液晶積層体１１０は、帯状の基材１１２と、前記基材１１２の裏面側に形成された液晶層１１４と、前記液晶層１１４の基材１１２側とは反対側の面に部分的に形成された背景層１１６と、前記背景層１１６の液晶層１１４側とは反対側の面に形成された熱接着性接着剤層１１８とからなる。
【００２５】
この実施の形態の液晶積層体１１０は、前記実施の形態の液晶積層体１０と、ほぼ同様の構成を有するが、背景層１１６が部分的に設けられてあり、前記実施の形態における背景層１６を形成するインキと同様のインキによって印刷することによって形成されている。背景層１１６は、文字、絵等からなる画線が、背景層１１６を形成する着色用インキを印刷して凸文字や抜き文字が形成されることによって、画線を構成するように形成されている。もっとも、背景層１１６は、液晶層１１４の裏面に全面にわたって形成されていてもよい。背景層１１６は、隠蔽性を備え、液晶層１１４の表面側から見ても、液晶層１１４が光輝性を示すように形成されている。なお、背景層１１６は、白色でもよい。背景層１１６が白色の場合は、液晶層１１４を通過した殆ど全ての波長の光が反射するので、背景層１１６が形成されている部分は白っぽく見える。そして、被着体Ａが、たとえば、黒色のとき、背景層１１６が形成されていない部分はグリーンからブルーの光輝性を示す。
【００２６】
コレステリック相からなる液晶層１１４を形成するためには、コレステリック相を形成する温度範囲に加熱する必要があり、液晶層１１４を形成する際の温度がそれより高い温度でも低い温度でもコレステリック相を形成しない。塗工後の液晶層形成用塗膜を一旦コレステリック相を形成する温度領域よりも高い温度、すなわち液体化温度に加熱した後コレステリック相を形成する温度領域に温度を下げた場合、光輝性が低下するおそれがあり、また、画線の鮮明性も劣化するおそれがあるので、塗工後の乾燥は、液体化温度まで加熱しないことが好ましい。且つ、コレステリック相を形成する温度領域にあっては、できる限り高い温度にすると光輝性等において有利である。これは、コレステリック相の配向（形成）がすみやかに確実に行われることによると想像される。
コレステリック相を形成した後は、コレステリック相をそのまま安定的に維持するため、コレステリック相形成温度領域の温度において架橋を行う等により、コレステリック相を固定する必要がある。
したがって、このような制限のない墨インキや、赤色、青色等の隠蔽性のあるインキあるいは白色インキで画線を形成する背景層１１６を形成し、背景層１１６との間に液晶層１１４を全面に形成する構成とすると、画線をより鮮明に形成しやすい。
また、液晶層１１４を全面に形成してあるこの実施の形態においては、たとえばスムージングバーのようなもので基材１１２上に塗工された液晶層形成塗工物の表面を掻いて、塗工物にシェアをかける等により、より確実に配向したコレステリック相の形成を促進するコレステリック相形成促進化処理を行うこともできるという特徴も有する。
【００２７】
また、基材１１２は、その厚さや材質について特に制限はないが、あまり薄くなると、液晶層形成用塗液や背景層形成用塗液等が塗工しにくくなり、基材１１２にシワ等が入り、変形しやすくなるので、２５μｍ程度以上の厚さが、より好ましく、また、逆にあまり厚くなると、ゴワゴワとし、小さな部品等のように曲面等を備えたものの表面に貼着する場合、貼着しにくくなるので、１５０μｍ程度以下が、より好ましい。
また、背景層１１６は、それぞれ隠蔽効果を出したいときは、一定の厚み以上であればよく、たとえば、１μｍ以上が好ましく、さらには、２〜５μｍ程度が、より好ましい。
液晶層１１４は、光輝性が目視できる厚さ以上であればよく、２〜５μｍ程度が、より好ましく、１μｍを下回ると、その濃度が薄くなるおそれがあるので、あまり好ましくはない。
【００２８】
熱接着性接着剤層１１８は、ＥＶＡ系樹脂、アイオノマー樹脂、アクリル系樹脂などのうち１または複数の樹脂を含む熱接着性接着剤を背景層１１６の裏面に塗布して形成されている。
これらの樹脂を含む熱接着性接着剤は、エマルジョンとして溶剤に溶解するかあるいは熱で溶融する等して、背景層１１６の裏面に塗工される。
その塗布の厚みは、１〜２０μｍが好ましく、より好ましくは１〜７μｍである。
【００２９】
前記液晶積層体１１０は、たとえば、図５（Ａ）に示すように、被着体Ａに熱接着性接着剤層１１８面を接合させ、適宜な文字や模様などの画線の凸版を備えた箔押板Ｂを加熱（通常１００℃〜１５０℃の温度）して液晶層１１４の表面側より押し当て、熱接着性接着剤層１１８を活性化させ、商品や商品等の保証書などのような被着体Ａに溶着（ホットスタンピング）される。そして、図５（Ｂ）に示すように、溶着によって液晶層１１４と基材１１２とが剥離し、基材１１２のない液晶層１１４、背景層１１６および熱接着性接着剤層１１８からなる転写体が商品や保証書などの被着体Ａに貼着する。
液晶積層体１１０を被着体Ａにホットスタンプしたとき、液晶積層体１１０の基材１１２と液晶層１１４が剥離して、基材１１２を取り除くことができるようにするために、たとえば、次のような構成とする。
基材１１２と液晶層１１４の接着強度を、他の層間、すなわち液晶層１１４と背景層１１６間および背景層１１６と熱接着性接着剤層１１８間の接着強度、および各層（液晶層１１４、背景層１１６、熱接着性接着剤層１１８）の凝集破壊強度より弱く構成する。その方法としては、たとえば、液晶層形成用塗液にバインダーを全く用いずまたはバインダーの量を抑制して、基材１１２と液晶層１１４との接着強度を調整する方法がある。
また、液晶積層体１１０を被着体Ａから剥がそうとしたとき、液晶積層体１１０が破壊して、他の偽物の品物に積層体を貼り替え、偽物を真正品と見せかけることができなくなるようにするために、たとえば次のような構成とする。
背景層１１６と液晶層１１４との凝集破壊強度を異ならしめたり、液晶層１１４と背景層１１６と熱接着性接着剤層１１８間の接着強度を異ならしめるように構成するとよい。
たとえば、液晶層１１４に、バインダーが含まれないか少ない場合には、液晶層１１４は基材１１２に付着しているだけかあるいは弱く接着している。
液晶層１１４上に、印刷等によって背景層１１６が形成されるが、背景層１１６形成時に、墨インキ等の背景層１１６成分が液晶層１１４の微細な凹み等に入り込むので、液晶層１１４と背景層１１６の接着強度は、液晶層１１４と基材１１２との間の接着強度より強くなり、背景層１１６と熱接着性接着剤層１１８との間の接着強度より弱くなると推定される。
【００３０】
望ましくは、この液晶積層体１１０を被着体Ａから剥がそうとしたとき、液晶層１１４等が凝集破壊する等、液晶積層体１１０が破壊するように構成するとよい。
すなわち、被着体Ａに貼られている積層体を剥がして、他の偽物の被着体Ａに貼り付けすることを防止するように、液晶積層体１１０を剥がそうとすると、液晶積層体１１０が破壊するような構成とする。そのために、たとえば、次のような構成としてもよい。
液晶層１１４と背景層１１６間および／または背景層１１６と熱接着性接着剤層１１８間の接着強度を異ならしめたり各層の凝集破壊強度を異ならしめるように構成する。その方法としては、たとえば、液晶層形成用塗液にバインダーを全く用いずまたはバインダーの量を抑制して、液晶層１１４と背景層１１６との接着強度を調整する方法がある。
このようにすれば、液晶層１１４と背景層１１６との間で層間剥離をしたり、液晶層１１４、あるいは液晶層１１４および背景層１１６において、凝集破壊し、液晶積層体１１０を被着体Ａから剥がそうとしたとき、液晶積層体１１０が破壊して、他の偽物の物品に積層体を貼り替えることができなくなる。もっとも、このような構成とするまでもなく、基材１１２が取り除かれて貼着されているので、液晶積層体１１０を破壊することなく被着体Ａから剥がすのは極めてむずかしい。
【００３１】
このように、この液晶積層体１１０は、液晶層１１４の裏面に、背景層１１６が形成されることにより、通常の印刷技術や複写技術では真正に近い積層体を作製し得ず、また、高度の印刷技術を有していたとしても、液晶、特にコレステリック相からなる液晶に関する知識がないと、コレステリック相が高度に配向した安定した液晶層が得られないので、積層体を偽造することが極めて難しくなり、且つ、積層体を貼り替えようとすると、積層体が破壊するために、積層体を偽物に貼り替え、偽物の被貼着体を本物に見せかけることも難しくなる。
【００３２】
【実施例２】
基材として、特に表面処理が施されていない、幅１６０ｍｍ、厚さ５０μｍのＰＥＴフィルム（株式会社東洋紡製Ｅ−５０００）を準備する。
次に基材の裏面に塗工されて液晶層を構成する塗液を準備する。
液晶層形成用塗液としては、次の混合塗液を用いる。
両末端にアクリル基を有するネマチック液晶（ＢＡＳＦ社のPaliocolor LC242）・・・５５．３重量％
キラル化合物（ＢＡＳＦ社のPaliocolor LC756）・・・２．９重量％
紫外線重合開始剤（チバスペシャリティ−ケミカルズ社のIrgacure 369）・・・１．８重量％
溶媒としてのメチルエチルケトン（ＭＥＫ）・・・４０．０重量％
次いで、基材裏面の全面にわたって、グラビア版により液晶層形成用塗液を塗工して、塗工後の平均厚さ３μｍとなる液晶層を形成する。
そして、液晶層上に、墨インキ塗液を、グラビア版により、乾燥後の厚さ２．５μｍとなるように塗工し、凸文字と抜き文字を設けて、背景層を形成する（背景層を形成するステップ）。
これ以外、すなわち、熱接着性接着剤層を形成するステップは、前記実施例１と同様にして液晶積層体を作成した。
その結果得られた液晶積層体は、実施例１と同様な効果を奏した上に、背景層が形成された部分においては、凸文字や抜き文字が視読できた。
【００３３】
なお、実施例２における凸文字、抜き文字は、グラビア印刷、フレキソ印刷、凸版印刷、スクリーン印刷等を用いて形成することができるが、その中でも、グラビア印刷、フレキソ印刷が、画線をクリアに形成し易い等のため好ましく、より好ましくは、グラビア印刷によって形成することである。
また、全面塗工（ベタ）は、前記したいずれの印刷方法によって形成してもよく、さらに、ナイフコーター、バーコータ等の方法によって塗工することもできる。
【００３４】
図６は、この発明の液晶積層体の別の実施の形態である断面図解図である。
この液晶積層体２１０は、帯状の基材２１２と、前記基材２１２の裏面側に部分的に形成された液晶層２１４と、前記液晶層２１４の基材２１２側とは反対側の面に形成された背景層２１６と、前記背景層２１６の液晶層２１４側とは反対側の面に形成された熱接着性接着剤層２１８とからなる。
液晶層２１４と背景層２１６と熱接着性接着剤層２１８とは、平面形状が略同一の形状となるように形成されている。
【００３５】
この実施の形態の液晶積層体２１０は、前記実施の形態の液晶積層体１０と、ほぼ同様の構成を有するが、液晶層２１４、背景層２１６および熱接着性接着剤層２１８が文字、絵等からなる画線が凸文字や抜き文字が形成されることによって、画線を構成するように形成されている。液晶層２１４は、文字、絵等からなる画線が、液晶層２１４を形成する液晶層形成用塗液を印刷して凸文字や抜き文字が形成されることによって、構成されるように形成されている。背景層２１６は、前記実施の形態の背景層１６を形成するインキと同様のインキによって印刷して凸文字や抜き文字が形成されることによって、画線を構成するように形成されている。もっとも、液晶層２１４は、基材２１２の裏面に全面にわたって形成されていてもよい。背景層２１６は、隠蔽性を備え、液晶層２１４の表面側から見ても、液晶層２１４が光輝性を示すように形成されている。なお、背景層２１６は、白色でもよい。背景層２１６が白色の場合は、液晶層２１４を通過した殆ど全ての波長の光が反射するので、背景層２１６が形成されている部分は白っぽく見える。そして、被着体Ａが、たとえば、黒色のとき、背景層２１６が形成されていない部分はグリーンからブルーの光輝性を示す。
【００３６】
コレステリック相からなる液晶層２１４を形成するためには、コレステリック相を形成する温度範囲に加熱する必要があり、液晶層２１４を形成する際の温度がそれより高い温度でも低い温度でもコレステリック相を形成しない。塗工後の液晶層形成用塗膜を一旦コレステリック相を形成する温度領域よりも高い温度、すなわち液体化温度に加熱した後コレステリック相を形成する温度領域に温度を下げた場合、光輝性が低下するおそれがあり、また、画線の鮮明性も劣化するおそれがあるので、塗工後の乾燥は、液体化温度まで加熱しないことが好ましい。且つ、コレステリック相を形成する温度領域にあっては、できる限り高い温度にすると光輝性等において有利である。これは、コレステリック相の配向（形成）がすみやかに確実に行われることによると想像される。
コレステリック相を形成した後は、コレステリック相をそのまま安定的に維持するため、コレステリック相形成温度領域の温度において架橋を行う等により、コレステリック相を固定する必要がある。
【００３７】
また、基材２１２は、その厚さや材質について特に制限はないが、あまり薄くなると、液晶層形成用塗液や背景層形成用塗液等が塗工しにくくなり、基材２１２にシワ等が入り、変形しやすくなるので、２５μｍ程度以上の厚さが、より好ましく、また、逆にあまり厚くなると、ゴワゴワとし、小さな部品等のように曲面等を備えたものの表面に貼着する場合、貼着しにくくなるので、１５０μｍ程度以下が、より好ましい。
また、背景層２１６は、それぞれ隠蔽効果を出したいときは、一定の厚み以上であればよく、たとえば、１μｍ以上が好ましく、さらには、２〜５μｍ程度が、より好ましい。
液晶層２１４は、光輝性が目視できる厚さ以上であればよく、２〜５μｍ程度が、より好ましく、１μｍを下回ると、その濃度が薄くなるおそれがあるので、あまり好ましくはない。
【００３８】
熱接着性接着剤層２１８は、ＥＶＡ系樹脂、アイオノマー樹脂、アクリル系樹脂などのうち１または複数の樹脂を含む熱接着性接着剤を背景層２１６の、あるいは液晶層２１４および背景層２１６の裏面に塗布して形成されている。
これらの樹脂を含む熱接着性接着剤は、エマルジョンとして溶剤に溶解するかあるいは熱で溶融する等して、背景層２１６の裏面に塗工される。
その塗布の厚みは、１〜２０μｍが好ましく、より好ましくは１〜７μｍである。
【００３９】
前記液晶積層体２１０は、たとえば、図７（Ａ）に示すように、被着体Ａに熱接着性接着剤層２１８面を接合させ、熱板や熱ロールを加熱して液晶層２１４の表面側より押し当て、熱接着性接着剤層２１８を活性化させ、商品や商品等の保証書などのような被着体Ａに溶着（ホットスタンピング）される。そして、図７（Ｂ）に示すように、溶着によって液晶層２１４と基材２１２とが剥離し、基材２１２のない液晶層２１４、背景層２１６および熱接着性接着剤層２１８からなる転写体が商品や保証書などの被着体Ａに貼着する。したがって、液晶層２１４、背景層２１６および熱接着性接着剤層２１８の順次形成された液晶積層体２１０によって画線等が表される。
液晶積層体２１０を被着体Ａにホットスタンプしたとき、液晶積層体２１０の基材２１２と液晶層２１４が剥離して、基材２１２を取り除くことができるようにするために、たとえば、次のような構成とする。
基材２１２と液晶層２１４の接着強度を、他の層間、すなわち液晶層２１４と背景層２１６間および背景層２１６と熱接着性接着剤層２１８間の接着強度、および各層（液晶層２１４、背景層２１６、熱接着性接着剤層２１８）の凝集破壊強度より弱く構成する。その方法としては、たとえば、液晶層形成用塗液にバインダーを全く用いずまたはバインダーの量を抑制して、基材２１２と液晶層２１４との接着強度を調整する方法がある。
また、液晶積層体２１０を被着体Ａから剥がそうとしたとき、液晶積層体２１０が破壊して、他の偽物の品物に積層体を貼り替え、偽物を真正品と見せかけることができなくなるようにするために、たとえば次のような構成とする。
背景層２１６と液晶層２１４との凝集破壊強度を異ならしめたり、液晶層２１４と背景層２１６と熱接着性接着剤層２１８間の接着強度を異ならしめるように構成するとよい。もっとも、このような構成とするまでもなく、基材２１２が取り除かれて貼着されているので、液晶積層体２１０を破壊することなく被着体Ａから剥がすのは極めてむずかしい。
【００４０】
望ましくは、この液晶積層体２１０を被着体Ａから剥がそうとしたとき、液晶層２１４等が凝集破壊する等、液晶積層体２１０が破壊するように構成するとよい。
すなわち、被着体Ａに貼られている積層体を剥がして、他の偽物の被着体Ａに貼り付けすることを防止するように、液晶積層体２１０を剥がそうとすると、液晶積層体２１０が破壊するような構成とする。そのために、たとえば、次のような構成としてもよい。
液晶層２１４と背景層２１６間および／または背景層２１６と熱接着性接着剤層２１８間の接着強度を異ならしめたり各層の凝集破壊強度を異ならしめるように構成する。その方法としては、たとえば、液晶層形成用塗液にバインダーを全く用いずまたはバインダーの量を抑制して、液晶層２１４と背景層２１６との接着強度を調整する方法がある。
このようにすれば、液晶層２１４と背景層２１６との間で層間剥離をしたり、液晶層２１４、あるいは液晶層２１４および背景層２１６において、凝集破壊し、液晶積層体２１０を被着体Ａから剥がそうとしたとき、液晶積層体２１０が破壊して、他の偽物の物品に積層体を貼り替えることができなくなる。
【００４１】
このように、この液晶積層体２１０は、液晶層２１４の裏面に、背景層２１６が形成されることにより、通常の印刷技術や複写技術では真正に近い積層体を作製し得ず、また、高度の印刷技術を有していたとしても、液晶、特にコレステリック相からなる液晶に関する知識がないと、コレステリック相が高度に配向した安定した液晶層が得られないので、積層体を偽造することが極めて難しくなり、且つ、積層体を貼り替えようとすると、積層体が破壊するために、積層体を偽物に貼り替え、偽物の被貼着体を本物に見せかけることも難しくなる。
【００４２】
前記実施の形態の説明においては、背景層について説明したが、被着体が黒色等の場合には被着体の表面が背景層の代わりの機能を有しているので、背景層を形成しなくてもよい。
【００４３】
図８は、この発明の液晶積層体の更に別の実施の形態である断面図解図である。
この液晶積層体３１０は、帯状の基材３１２と、前記基材３１２の裏面側に部分的に形成された液晶層３１４と、前記液晶層３１４の基材３１２側とは反対側の面に部分的に形成された熱接着性接着剤層３１８とからなる。
液晶層３１４と熱接着性接着剤層３１８とは、略同一の平面形状に形成されている。
【００４４】
この実施の形態の液晶積層体３１０は、前記実施の形態の液晶積層体１０と、ほぼ同様の構成を有するが、液晶層３１４および熱接着性接着剤層３１８が文字、絵等からなる画線が、凸文字や抜き文字が形成されることによって、画線を構成するように形成されている。なお、液晶層３１４と熱接着性接着剤層３１８は全面（ベタ）に形成することもできる。前記液晶積層体３１０は、被着体Ａに熱接着性接着剤層３１８面を接合させ、適宜な熱板や熱ロールを加熱して液晶層３１４の表面側より押し当て、熱接着性接着剤層３１８を活性化させ、その表面が黒色等の商品などのような被着体Ａに溶着（ホットスタンピング）される。そして、溶着によって液晶層３１４と基材３１２とが剥離し、基材３１２のない液晶層３１４と熱接着性接着剤層３１８とからなる転写体が商品などの被着体Ａに貼着する。
この実施の形態の液晶積層体３１０は、被着体Ａが黒色をしていて前記実施の形態の背景層１６の代わりをして、液晶層３１４が光輝性を示す。
液晶積層体３１０を被着体Ａにホットスタンプしたとき、液晶積層体３１０の基材３１２と液晶層３１４が剥離して、基材３１２を取り除くことができるようにするために、たとえば、次のような構成とする。
基材３１２と液晶層３１４の接着強度を、他の層間、すなわち液晶層３１４と熱接着性接着剤層３１８間の接着強度、および各層（液晶層３１４、熱接着性接着剤層３１８）の凝集破壊強度より弱く構成する。その方法としては、たとえば、液晶層形成用塗液にバインダーを全く用いずまたはバインダーの量を抑制して、基材３１２と液晶層３１４との接着強度を調整する方法がある。
【００４５】
また、基材３１２の表面（液晶層３１４を形成させた面とは反対側の面）を外側とし、熱接着性接着剤層３１８を内側として巻回された液晶層積層連続体として、利用できる。
【００４６】
【発明の効果】
この発明によれば、しなやかで、被着体の面に沿って貼着し易く、比較的低コストで製造することができ、偽造防止用積層体として用いることが可能な、液晶積層体および液晶積層連続体を提供することができる。
【図面の簡単な説明】
【図１】この発明の一実施の形態である液晶積層体の断面図解図である。
【図２】コレステリック相の分子配列を示す図解図である。
【図３】液晶積層体の被着体の圧着する方法を示す断面図解図である。
【図４】この発明の別の実施の形態である液晶積層体の断面図解図である。
【図５】図４図示の液晶積層体の被着体の圧着する方法を示す断面図解図である。
【図６】この発明の更に別の実施の形態である液晶積層体の断面図解図である。
【図７】図６図示の液晶積層体の被着体の圧着する方法を示す断面図解図である
【図８】この発明の液晶積層体の更に別の実施の形態である断面図解図である。
【符号の説明】
１０ １１０ ２１０ ３１０ 液晶積層体
１２ １１２ ２１２ ３１２ 基材
１４ １１４ ２１４ ３１４ 液晶層
１６ １１６ ２１６ ３１６ 背景層
１８ １１８ ２１８ ３１８ 接着剤層
Ａ 被着体
Ｂ 箔押板[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a liquid crystal laminateAnd liquid crystal laminated continuumIn particular, for example, a liquid crystal laminate suitable for use as a laminate capable of preventing forgeryAnd liquid crystal laminated continuumAbout.
[0002]
[Prior art]
Conventionally, the recording layer of the label has been formed by thermal recording, thermal color development, printing, etc., so it is relatively easy to make a fake label. I have. In addition, a label using a material that emits light when irradiated with ultraviolet rays, infrared rays, or the like can be recognized as a fake only by irradiating ultraviolet rays or infrared rays, and it is difficult to determine authenticity only by visual observation.
In view of this, there has been proposed a label capable of authenticity identification, such as an authenticity identification label disclosed in JP-A-2002-205471.
[0003]
[Problems to be solved by the invention]
This conventional authenticity distinguishable label uses a display material containing a cholesteric liquid crystal pigment, which is rarely used as a display material of the conventional label. Therefore, if there is no knowledge of these materials, the function of the material is exhibited. For this reason, it is suitable as an anti-counterfeit label because it is difficult to forge.
However, since it is difficult to realize the object of the invention, the cost of the label increases, and for example, it is not suitable for use as an anti-counterfeit label for a low-priced part, and is not flexible. That is, on a layer such as a liquid crystal layer, a microsphere transparent bead having a diameter of 10 to 100 μm, preferably 50 μm or less, preferably a glass (hard) bead, while the layer still does not lose its adhesiveness. It is difficult to control because it must be formed in a single layer so that it does not overlap evenly, preferably two or more layers, so there is a problem in the reproducibility of manufacturing, and the yield must be reduced. Costs are rising and flexibility is insufficient.
Therefore, those that do not employ the operation of aligning microbeads or the operation of laminating other layers with the liquid crystal layer being sticky have higher reproducibility of labels with the same performance and higher yield. It is easy to manufacture an anti-counterfeit label that can be manufactured at a low cost and that can be immediately discriminated from a general-purpose label only by changing the viewing direction and observing the label.
[0004]
  Therefore, the main object of the present invention is to provide a liquid crystal that is flexible, can be easily adhered along the surface of the adherend, can be manufactured at a relatively low cost, and can be used as a laminate for preventing forgery. Laminated bodyAnd liquid crystal laminated continuumIs to provide.
[0005]
[Means for Solving the Problems]
  The liquid crystal laminate according to claim 1 of the present invention includes a base material, a liquid crystal layer formed on the back surface side of the base material, and a thermal bond formed on the surface of the liquid crystal layer opposite to the base material side. It is formed so that the substrate and the liquid crystal layer are peeled off when the heat-adhesive adhesive layer is heated and bonded to the adherend.In the liquid crystal laminate, a PET film whose surface is not subjected to surface treatment is used, and liquid crystal molecules capable of forming a cholesteric phase are directly applied to the back surface of the PET film where surface treatment is not performed. The coating is heated to a temperature at which the molecules form a cholesteric phase to form a cholesteric phase liquid crystal, and the coating containing the cholesteric phase liquid crystal is irradiated with ultraviolet rays to crosslink the liquid crystal molecules and fix the cholesteric phase liquid crystal. By forming a fixed cholesteric phase liquid crystal layer,It is a liquid crystal laminate.
  The liquid crystal laminate according to claim 2 according to the present invention includes a base material, and a liquid crystal layer formed on the back side of the base material.What is the substrate side of the liquid crystal layer?It consists of a heat-adhesive adhesive layer formed on the opposite surface, and is formed so that the substrate and the liquid crystal layer are peeled off when the heat-adhesive adhesive layer is heated and bonded to the adherend.In a liquid crystal laminate, a PET film whose surface treatment is not applied to the base material is used, and a mixture of liquid crystal molecules and a chiral compound capable of forming a nematic phase directly on the back surface side where the surface treatment of the PET film is not applied. The liquid crystal molecules are coated and heated to a temperature at which liquid crystal molecules mixed with a chiral compound form a cholesteric phase to form a cholesteric phase liquid crystal, and then the liquid crystal is irradiated by irradiating the coated material containing the cholesteric phase liquid crystal with ultraviolet rays. By fixing the cholesteric phase liquid crystal by cross-linking molecules, a fixed cholesteric phase liquid crystal layer is formed.It is a liquid crystal laminate.
  The liquid crystal laminate according to claim 3 according to the present invention,A background layer is formed on the surface of the liquid crystal layer opposite to the base material side, and a thermal adhesive layer is formed on the surface of the background layer opposite to the liquid crystal layer side.A liquid crystal laminate according to claim 1 or 2.
  Claim 4 according to the present inventionThe liquid crystal laminate continuum is composed of a base material, a liquid crystal layer formed on the back side of the base material, and a heat-adhesive adhesive layer formed on the surface of the liquid crystal layer opposite to the base material side. When the adhesive adhesive layer is heated and adhered to the adherend, it is formed so that the substrate and the liquid crystal layer are peeled off, and the surface of the substrate is the outside, and the thermal adhesive layer is the inside. In the liquid crystal laminated continuum, a PET film whose surface is not subjected to surface treatment is used, and liquid crystal molecules capable of forming a cholesteric phase are directly applied to the back surface of the PET film where surface treatment is not performed. The cholesteric phase liquid crystal is formed by heating the coating material to a temperature at which the liquid crystal molecules form a cholesteric phase, and irradiating the coating material containing the cholesteric phase liquid crystal with ultraviolet rays to crosslink the liquid crystal molecules. By fixing By forming a fixed cholesteric phase liquid crystal layer, the liquid crystal laminate continuumIt is.
  Claim 5 according to the present inventionThe liquid crystal laminate continuum is composed of a base material, a liquid crystal layer formed on the back side of the base material, and a heat-adhesive adhesive layer formed on the surface of the liquid crystal layer opposite to the base material side. When the adhesive adhesive layer is heated and adhered to the adherend, it is formed so that the substrate and the liquid crystal layer are peeled off, and the surface of the substrate is the outside, and the thermal adhesive layer is the inside. In the liquid crystal laminated continuum, a PET film whose surface is not subjected to surface treatment is used, and a liquid crystal molecule and a chiral compound that can form a nematic phase directly on the back surface of the PET film that is not subjected to surface treatment. Applying the mixture, heating the coating material to a temperature at which the liquid crystal molecules mixed with the chiral compound form a cholesteric phase to form a cholesteric phase liquid crystal, and irradiating the coating material containing the cholesteric phase liquid crystal with ultraviolet rays To crosslink liquid crystal molecules By fixing the cholesteric phase liquid crystal, by forming a fixed cholesteric phase liquid crystal layer, the liquid crystal laminate continuumIt is.
  Claim 6 according to the present inventionThe liquid crystal laminate continuum is formed by forming a background layer on the surface opposite to the substrate side of the liquid crystal layer, and forming a thermal adhesive layer on the surface of the background layer opposite to the liquid crystal layer side. The liquid crystal laminated continuum according to claim 4 or 5.It is.
  Claim 1Or claim 6According to the invention, for example, a liquid crystal laminate in which a liquid crystal layer and a heat-adhesive adhesive layer are laminated on the surface of a substrate having continuity, for example, by hot stamping, a liquid crystal can be easily applied to an adherend. The layer stack can be glued. In addition, after the substrate and the liquid crystal layer are peeled off, the liquid crystal layer of the transfer body exhibits glitter and plays a role of preventing counterfeiting along with the design effect.
  Claim3 and 6According to the invention, for example, a liquid crystal laminate in which a liquid crystal layer, a background layer, and a thermal adhesive layer are laminated on the back surface of a substrate having continuityAnd liquid crystal laminated continuumIs easy to handle and can be appropriately transferred to the adherend, for example, by hot stamping, etc. After the substrate is peeled from the liquid crystal layer, the liquid crystal layer of the transfer body exhibits glitter, It can be set as the sticking body which has forgery prevention property.
  AndIn addition, since the liquid crystal layer of the transfer body transferred to the adherend exhibits glitter, it is possible to obtain an adhesive body that further contributes to designability and prevention of forgery.
  Also,Partially on the surface of the liquid crystal layer opposite the substrate sideForming a background layerThus, from the surface of the liquid crystal layer, for example, an image line such as letters due to the partially formed background layer can be visually observed, and a liquid crystal laminate excellent in design can be obtained.
  Also,When pasted on an adherend, for example, by a liquid crystal layer, a background layer and a heat-adhesive adhesive layer partially formed on the back surface of the base material, the transfer body generally represents an image line such as characters. And the sticking body which contributes to the prevention of forgery excellent in the designability can be obtained by the brightness which a liquid crystal layer shows.
  Furthermore, claims 4 to 6According to the invention, a liquid crystal layer laminated continuous body, for example, a liquid crystal layer and a heat-adhesive adhesive layer or a liquid crystal layer, a background layer, and a heat-adhesive adhesive layer are continuously formed by a hot stamping device. The transfer body can be continuously attached to the adherend, and the attaching operation to the adherend can be performed very efficiently.
[0006]
The above object, other objects, features, and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention with reference to the drawings.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an illustrative sectional view of a liquid crystal laminate according to one embodiment of the present invention.
In this liquid crystal laminate 10, a belt-like base material 12 made of a synthetic resin sheet or film such as a polyester film and a liquid crystal (chiral nematic liquid crystal) showing a cholesteric phase formed on the back side of the base material 12 are fixed. A liquid crystal layer 14 formed on the surface of the liquid crystal layer 14 opposite to the substrate 12 side, and the background layer 16 formed to highlight the glitter of the liquid crystal layer 14; The layer 16 includes a heat-adhesive adhesive layer 18 formed by applying a heat-adhesive adhesive formed on a surface opposite to the liquid crystal layer 14 side.
[0008]
  The substrate 12 is PETFilm or sheetUseButIn particular, the surface of the base material 12 on the side where the liquid crystal layer 14 is formed (that is, the back surface of the base material 12) is applied to the adherend A by heating the heat-adhesive adhesive layer 18. Then, it is desirable that the substrate 12 and the liquid crystal layer 14, the background layer 16, and the heat-adhesive adhesive layer 18 have excellent smoothness so that they can be easily delaminated between the liquid crystal layer 14. Further, in order to facilitate delamination between the substrate 12 and the liquid crystal layer 14, it is desirable that the surface side on which the liquid crystal layer 14 is formed is not subjected to surface treatment..
[0009]
A cholesteric liquid crystal is selected as the liquid crystal composition constituting the liquid crystal layer 14, and the cholesteric liquid crystal (chiral nematic liquid crystal) is formed by coating a compound having a helical cholesteric phase or a chiral nematic phase (see FIG. 2). .
Examples of compounds exhibiting a cholesteric phase include those shown in Table 1 in addition to cholesteryl nonanoate, cholesteryl myristate, and the like.
[0010]
[Table 1]

(Note in Table 1) C is a crystalline solid, S is a smectic phase, Sc is a chiral smectic C phase, Ch is a cholesteric phase, N^*Represents a chiral nematic phase, and I represents an isotropic liquid.
[0011]
Further, a chiral nematic phase can be formed by adding a chiral compound shown in Table 3 to a compound showing a nematic phase alone shown in Table 2 (hereinafter, without distinguishing between a cholesteric phase and a chiral nematic phase, Generically).
[0012]
[Table 2]

(Note in Table 2) C represents a crystalline solid, N represents a nematic phase, and I represents an isotropic liquid.
[0013]
[Table 3]

(Note to Table 3) When chiral molecules are added to a liquid crystal exhibiting a nematic phase, the chiral nematic phase (N^*) Is obtained. In this case, the reciprocal 1 / P of the pitch of the mixed liquid crystal is the molar concentration X of the chiral molecule._BIn the region where is small, X_BIs proportional to Therefore, 1 / PX_BThis is called chiral torsional force.
[0014]
The liquid crystal layer 14 according to the present invention has a cholesteric phase fixed. As a fixing method, for example, an acrylic group is provided at both ends of liquid crystal molecules, and this is applied to the substrate 12. The coated product is heated to a temperature at which a cholesteric phase can be formed, a cholesteric phase is formed, and UV irradiation is performed by UV irradiation to fix the cholesteric phase.
Therefore, the cholesteric phase exists stably even if the environment such as temperature changes.
Alternatively, a mixture of liquid crystal molecules and a commonly used binder may be applied, heated to a temperature at which a cholesteric phase can be formed, a cholesteric phase formed, dried, and the cholesteric phase fixed with a binder.
[0015]
The liquid crystal layer forming coating solution may be solvent-based or non-solvent-based.
In the solvent system, ketones such as MEK and MIBK, toluene, ethyl acetate and the like are preferable. The solid content concentration is not particularly limited, but is preferably 25 to 67%. If it is less than 25%, the image line may not be formed clearly, and the time required for drying becomes longer. If it exceeds 67%, solids may be deposited unless the coating liquid is heated. A particularly preferred concentration range is 50 to 65%. In order to eliminate the possibility of solid precipitation due to evaporation of the solvent from the coating liquid, coating is also performed while heating the coating liquid.
In the non-solvent system, coating is performed while heating the coating composition to a temperature equal to or higher than the temperature at which the cholesteric phase is formed, preferably at a temperature in the temperature range where the cholesteric phase is formed.
In order to fix the cholesteric phase formed in the coated product, both in the solvent system and in the non-solvent system, crosslinking or the like is performed while keeping the liquid crystal layer-forming coated product in the temperature range in which the cholesteric phase is formed. Thus, the cholesteric phase is stably maintained even at a normal temperature, for example, even if the temperature environment changes.
[0016]
The liquid crystal layer 14 composed of a cholesteric phase exhibits glitter, and the color tone changes continuously depending on the viewing direction. For example, it looks green when viewed vertically from above, and appears blue when viewed in a horizontal direction.
The liquid crystal layer 14 exhibiting the cholesteric phase has a characteristic that only a part of the wavelength region of light incident in a wide spectral region is reflected and all the wavelengths in other regions are transmitted.
[0017]
The liquid crystal layer 14 is formed over the entire back surface of the substrate 12.
When the spiral pitch P (shown in FIG. 2) is increased, the color on the long wavelength side appears, and when the spiral pitch P is decreased, the color on the short wavelength side appears. In order to change this pitch, the addition amount of the chiral compound may be changed in the system to which the chiral compound is added.
[0018]
The background layer 16 is formed by printing / coating a black ink or a colored ink such as red / blue over the entire back surface of the liquid crystal layer 14. The background layer 16 is formed to make the glitter of the liquid crystal layer 14 stand out, and is formed over the entire back surface of the substrate 12 so as to cover the liquid crystal layer 14. In particular, as the background layer 16, black formed with black ink or the like is excellent for making the glitter of the liquid crystal layer 14 stand out.
Further, since the visual color tone of the liquid crystal layer 14 changes depending on the color of the background layer 16, the composition and color of the ink forming the background layer 16 are important. For example, when the color of the background layer 16 is black, when the liquid crystal layer 14 is visually observed, green to blue glitter is exhibited, whereas when the background layer 16 is red, the liquid crystal layer 14 is visually observed from orange. When the background layer 16 is colored near white, the liquid crystal layer 14 is milky white or pearly.
Therefore, when the color forming the background layer 16 is divided into two or more, when the liquid crystal layer 14 is viewed, the colorful liquid crystal laminate 10 corresponding to the color change of the background layer 16 is obtained.
[0019]
The heat-adhesive adhesive layer 18 is formed by applying a heat-adhesive adhesive containing one or more of EVA resin, ionomer resin, acrylic resin, and the like to the back surface of the background layer 16.
The heat-adhesive adhesive containing these resins is applied to the back surface of the background layer 16 by being dissolved in a solvent as an emulsion or melted by heat.
The thickness of the coating is preferably 1 to 20 μm, more preferably 1 to 7 μm.
[0020]
For example, as shown in FIG. 3 (A), the liquid crystal laminate 10 is provided with a relief of image lines such as appropriate characters and patterns by bonding the surface of the heat-adhesive adhesive layer 18 to the adherend A. The foil pressing plate B is heated and pressed (pressed) from the surface side with the liquid crystal layer 14 to activate the heat-adhesive adhesive layer 18 and adhere to an adherend A such as a warranty card for goods or goods. It is welded (hot stamping). Then, as shown in FIG. 3B, the liquid crystal layer 14 and the base material 12 are peeled off by welding, and a transfer body comprising the liquid crystal layer 14 without the base material 12, the background layer 16, and the thermoadhesive adhesive layer 18. Sticks to the adherend A such as a product or a warranty card.
When the liquid crystal laminate 10 is hot stamped on the adherend A, the base material 12 and the liquid crystal layer 14 of the liquid crystal laminate 10 are peeled off so that the base material 12 can be removed. The configuration is as follows.
The adhesive strength between the substrate 12 and the liquid crystal layer 14 is determined based on the adhesive strength between the other layers, that is, between the liquid crystal layer 14 and the background layer 16 and between the background layer 16 and the heat-adhesive adhesive layer 18, and each layer (liquid crystal layer 14, background The layer 16 is made weaker than the cohesive failure strength of the heat-adhesive adhesive layer 18). As the method, for example, there is a method of adjusting the adhesive strength between the substrate 12 and the liquid crystal layer 14 without using any binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
Further, even if the liquid crystal laminate 10 is to be peeled off from the adherend A, the substrate 12 is removed from the liquid crystal laminate 10, so that the liquid crystal laminate 10 is peeled off without breaking and the liquid crystal laminate is laminated on another product. It is very difficult to replace the body 10 and make the fake look like a genuine product. Furthermore, when the liquid crystal laminate 10 is to be peeled off from the adherend A, the liquid crystal laminate 10 is destroyed, and the liquid crystal laminate 10 can be replaced with another fake product, making it appear that the fake is a genuine product. For example, the following configuration is more effective in order to eliminate the loss.
The cohesive failure strength between the background layer 16 and the liquid crystal layer 14 may be made different, or the adhesive strength between the liquid crystal layer 14, the background layer 16, and the heat-adhesive adhesive layer 18 may be made different.
[0021]
[Example 1]
As a base material, a surface-treated PET film having a width of 160 mm and a thickness of 50 μm (E-5000 manufactured by Toyobo Co., Ltd.) is prepared and separately applied to the back surface of the base material to form a liquid crystal layer. Prepare the coating solution.
As the liquid crystal layer forming coating solution, the following mixed coating solution is used.
Nematic liquid crystal with acrylic groups at both ends (Paliocolor LC242 from BASF) ... 55.3% by weight
Chiral compound (Paliocolor LC756 from BASF) 2.9% by weight
UV polymerization initiator (Irgacure 369 from Ciba Specialty Chemicals) ... 1.8% by weight
Methyl ethyl ketone (MEK) as solvent: 40.0% by weight
Using this liquid crystal forming coating solution, coating is performed with a gravure plate so that the thickness after drying becomes 3 μm, and the coating is dried by passing through a drying zone (110 to 120 ° C.) for 15 seconds to form a cholesteric phase. . Immediately thereafter, ultraviolet irradiation is performed to perform ultraviolet UV curing to fix the cholesteric phase. The temperature for forming the nematic liquid crystal is 59 ° C. or higher and 120 to 124 ° C. or lower.
Thereby, a liquid crystal layer composed of a stable cholesteric phase is formed on the substrate (step of forming a liquid crystal layer).
Next, a black ink coating liquid (PANE ECO manufactured by Toyo Ink Manufacturing Co., Ltd.) for forming the background layer is prepared, and this black ink coating liquid is coated on the back surface of the substrate with a gravure plate so as to cover the liquid crystal layer. It coats so that it may become the average thickness of 3 micrometers after drying. Thereafter, the black ink coating liquid is dried by passing through a drying zone (70 to 80 ° C.) for 3 seconds.
Thus, a background layer covering the liquid crystal layer is formed on the back surface of the substrate (step of forming the background layer).
[0022]
Apply a 45% solid content emulsion of Chuo Rika Kogyo Co., Ltd. thermal adhesive (EVA resin, HA-1100) with a wire bar (No. 5) and dry it with a hot air dryer at 50 ° C for 2 minutes. And a heat-adhesive adhesive layer is formed (dry coating thickness is 2 μm).
[0023]
In the liquid crystal laminate of this example, a heat-adhesive adhesive layer is bonded to an adherend (made of polypropylene), and a metal relief plate heated to 120 ° C. is pressure-bonded for several seconds so that the base material is attached to the surface of the liquid crystal layer. When viewed from the liquid crystal side of the part that was removed and crimped by the convex part of the plate, it showed a bright glitter that changed from green to blue-violet depending on the viewing direction.
Further, in this embodiment, the liquid crystal layer is formed without using any binder in the liquid crystal layer forming coating liquid constituting the liquid crystal layer. Since it is weaker than the adhesive strength between layers and the cohesive failure strength of each layer, it is attached to the adherend (made of polypropylene), peeled off between the substrate and the liquid crystal layer, and another layer on the adherend Was able to stick without breaking.
In this embodiment, since UV crosslinking (curing) is performed, when the foil is pressed (usually performed at a temperature of about 100 to 150 ° C.), the liquid crystal layer 14 remains as it is even when heated to 120 to 124 ° C. or higher. Keep state. However, even if it is not crosslinked, for example, when foil pressing is performed, if the temperature is set to about 110 ° C., the liquid crystal layer 14 does not become a liquid phase but is maintained in the liquid crystal phase.
Further, when the liquid crystal layer 14 is fixed using a binder, the liquid crystal phase is maintained at least up to a temperature at which the binder is fluidized.
In this embodiment, the adhesive strength at the interface between the liquid crystal layer 14 and the background layer 16 is designed by making the adhesive strength at the interface between the background layer 16 and the thermal adhesive layer 18 different from each other and the cohesive failure strength of each layer. be able to.
For example, the following is recommended.
When the liquid crystal layer 14 contains no or little binder, the liquid crystal layer 14 is only attached to the substrate 12 or is weakly bonded.
The background layer 16 is formed on the liquid crystal layer 14 by printing or the like, but when the background layer 16 is formed, the background layer 16 components such as black ink enter into the fine dents of the liquid crystal layer 14, so the liquid crystal layer 14 and the background The adhesive strength of the layer 16 is estimated to be stronger than the adhesive strength between the liquid crystal layer 14 and the substrate 12 and weaker than the adhesive strength between the background layer 16 and the heat-adhesive adhesive layer 18.
[0024]
FIG. 4 is a cross-sectional view showing another embodiment of the liquid crystal laminate of the present invention.
The liquid crystal laminate 110 is partially formed on a band-shaped base material 112, a liquid crystal layer 114 formed on the back surface side of the base material 112, and a surface opposite to the base material 112 side of the liquid crystal layer 114. The background layer 116 and a heat-adhesive adhesive layer 118 formed on the surface of the background layer 116 opposite to the liquid crystal layer 114 side.
[0025]
The liquid crystal laminate 110 of this embodiment has substantially the same configuration as the liquid crystal laminate 10 of the above embodiment, but a background layer 116 is partially provided, and the background layer 16 in the above embodiment. It is formed by printing with the same ink as the ink which forms. The background layer 116 is formed so that an image line composed of characters, pictures, etc. is formed by printing the coloring ink forming the background layer 116 to form convex characters and blank characters. Yes. However, the background layer 116 may be formed on the entire back surface of the liquid crystal layer 114. The background layer 116 has a concealing property and is formed so that the liquid crystal layer 114 exhibits glitter even when viewed from the surface side of the liquid crystal layer 114. The background layer 116 may be white. When the background layer 116 is white, light of almost all wavelengths that have passed through the liquid crystal layer 114 is reflected, so that the portion where the background layer 116 is formed looks whitish. When the adherend A is, for example, black, the portion where the background layer 116 is not formed exhibits green to blue glitter.
[0026]
In order to form the liquid crystal layer 114 composed of the cholesteric phase, it is necessary to heat to a temperature range in which the cholesteric phase is formed, and the cholesteric phase is formed even when the temperature at which the liquid crystal layer 114 is formed is higher or lower. do not do. When the coating film for forming a liquid crystal layer after coating is once heated to a temperature higher than the temperature range in which the cholesteric phase is formed, that is, to the temperature range in which the cholesteric phase is formed after being heated to the liquefaction temperature, the glittering property decreases. In addition, it is preferable that the drying after coating is not heated to the liquefaction temperature. Moreover, in the temperature region where the cholesteric phase is formed, it is advantageous in terms of brightness and the like when the temperature is set as high as possible. This is presumably due to the fact that the orientation (formation) of the cholesteric phase is performed promptly and reliably.
After the cholesteric phase is formed, it is necessary to fix the cholesteric phase by performing crosslinking at a temperature in the cholesteric phase formation temperature region in order to stably maintain the cholesteric phase as it is.
Therefore, the background layer 116 for forming the image line is formed with the black ink without limitation and the concealing ink such as red and blue, or the white ink, and the liquid crystal layer 114 is formed between the background layer 116 and the entire surface. If the structure is formed, the image line is easily formed more clearly.
Further, in this embodiment in which the liquid crystal layer 114 is formed on the entire surface, the surface of the liquid crystal layer forming coated material coated on the substrate 112 is scratched with a smoothing bar, for example, It also has a feature that a cholesteric phase formation promoting treatment that promotes the formation of a more reliably oriented cholesteric phase can be performed by applying a share to the product.
[0027]
Further, the thickness and material of the base material 112 are not particularly limited. However, if the thickness is too thin, it becomes difficult to apply the liquid crystal layer forming coating liquid or the background layer forming coating liquid, and the base material 112 is wrinkled. It is more preferable to have a thickness of about 25 μm or more because it easily enters and deforms. On the contrary, if it becomes too thick, it will be confused, and if it is attached to the surface of a curved surface such as a small part, Since it becomes difficult to wear, about 150 micrometers or less are more preferable.
Further, the background layer 116 may have a certain thickness or more when it is desired to provide a concealing effect, for example, preferably 1 μm or more, and more preferably about 2 to 5 μm.
The liquid crystal layer 114 only needs to have a thickness that allows the brightness to be visually recognized, and is preferably about 2 to 5 μm. If the thickness is less than 1 μm, the concentration may be reduced, which is not preferable.
[0028]
The heat-adhesive adhesive layer 118 is formed by applying a heat-adhesive adhesive containing one or more of EVA resin, ionomer resin, acrylic resin, and the like to the back surface of the background layer 116.
The heat-adhesive adhesive containing these resins is applied to the back surface of the background layer 116 by being dissolved in a solvent as an emulsion or melted by heat.
The thickness of the coating is preferably 1 to 20 μm, more preferably 1 to 7 μm.
[0029]
For example, as shown in FIG. 5A, the liquid crystal laminate 110 is provided with a relief of an image line such as an appropriate character or pattern by bonding the surface of the heat-adhesive adhesive layer 118 to the adherend A. The foil stamping plate B is heated (usually at a temperature of 100 ° C. to 150 ° C.) and pressed from the surface side of the liquid crystal layer 114 to activate the heat-adhesive adhesive layer 118, such as a guarantee for a product or a product, etc. It is welded (hot stamped) to the adherend A. Then, as shown in FIG. 5B, the liquid crystal layer 114 and the base material 112 are peeled off by welding, and the transfer body is composed of the liquid crystal layer 114 without the base material 112, the background layer 116, and the heat-adhesive adhesive layer 118. Sticks to the adherend A such as a product or a warranty card.
In order to allow the substrate 112 and the liquid crystal layer 114 of the liquid crystal laminate 110 to be peeled off when the liquid crystal laminate 110 is hot stamped on the adherend A, for example, The configuration is as follows.
The adhesive strength between the base material 112 and the liquid crystal layer 114 is determined based on the adhesive strength between the other layers, that is, between the liquid crystal layer 114 and the background layer 116 and between the background layer 116 and the heat-adhesive adhesive layer 118, and each layer (liquid crystal layer 114, background The layer 116 is made weaker than the cohesive failure strength of the heat-adhesive adhesive layer 118). As the method, for example, there is a method of adjusting the adhesive strength between the substrate 112 and the liquid crystal layer 114 without using any binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
Further, when the liquid crystal laminate 110 is about to be peeled off from the adherend A, the liquid crystal laminate 110 is destroyed, so that the laminate can be replaced with another fake product so that the fake cannot appear to be a genuine product. For example, the following configuration is adopted.
The cohesive failure strength between the background layer 116 and the liquid crystal layer 114 may be made different, or the adhesive strength between the liquid crystal layer 114, the background layer 116, and the heat-adhesive adhesive layer 118 may be made different.
For example, when the liquid crystal layer 114 contains no or little binder, the liquid crystal layer 114 is only attached to the substrate 112 or is weakly adhered.
The background layer 116 is formed on the liquid crystal layer 114 by printing or the like, but when the background layer 116 is formed, the background layer 116 components such as black ink enter the fine dents of the liquid crystal layer 114, so the liquid crystal layer 114 and the background The adhesive strength of the layer 116 is estimated to be stronger than the adhesive strength between the liquid crystal layer 114 and the substrate 112 and weaker than the adhesive strength between the background layer 116 and the thermal adhesive layer 118.
[0030]
Desirably, the liquid crystal laminate 110 may be broken when the liquid crystal laminate 110 is peeled off from the adherend A, such that the liquid crystal layer 114 or the like breaks down.
That is, when the liquid crystal laminate 110 is peeled off so as to prevent the laminate attached to the adherend A from being peeled off and attached to another fake adherend A, the liquid crystal laminate 110 is removed. Is configured to destroy. Therefore, for example, the following configuration may be used.
The liquid crystal layer 114 and the background layer 116 and / or the background layer 116 and the heat-adhesive adhesive layer 118 are configured to have different adhesive strengths or different cohesive fracture strengths. As the method, for example, there is a method of adjusting the adhesive strength between the liquid crystal layer 114 and the background layer 116 without using any binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
In this way, delamination is caused between the liquid crystal layer 114 and the background layer 116, or the liquid crystal layer 114, or the liquid crystal layer 114 and the background layer 116 are agglomerated and broken, so that the liquid crystal stack 110 is adhered to the adherend A. When the film is peeled off, the liquid crystal laminate 110 is destroyed, and the laminate cannot be replaced with another fake article. Needless to say, since the base material 112 is removed and attached without being configured as described above, it is extremely difficult to remove the liquid crystal laminate 110 from the adherend A without destroying it.
[0031]
As described above, the liquid crystal laminate 110 cannot be formed into a nearly authentic laminate by a normal printing technique or copying technique because the background layer 116 is formed on the back surface of the liquid crystal layer 114. Even if you have the printing technology, if you don't have knowledge about liquid crystal, especially liquid crystal composed of cholesteric phase, you can't get a stable liquid crystal layer with highly oriented cholesteric phase. It becomes difficult, and when the laminate is to be replaced, the laminate is destroyed, so that it is difficult to replace the laminate with a fake and make the fake adherend appear to be real.
[0032]
[Example 2]
As a base material, a PET film (E-5000 manufactured by Toyobo Co., Ltd.) having a width of 160 mm and a thickness of 50 μm, which is not particularly surface-treated, is prepared.
Next, a coating liquid is prepared which is applied to the back surface of the base material to constitute the liquid crystal layer.
As the liquid crystal layer forming coating solution, the following mixed coating solution is used.
Nematic liquid crystal with acrylic groups at both ends (Paliocolor LC242 from BASF) ... 55.3% by weight
Chiral compound (Paliocolor LC756 from BASF) 2.9% by weight
UV polymerization initiator (Irgacure 369 from Ciba Specialty Chemicals) ... 1.8% by weight
Methyl ethyl ketone (MEK) as solvent: 40.0% by weight
Next, a liquid crystal layer forming coating solution is applied over the entire back surface of the substrate by a gravure plate to form a liquid crystal layer having an average thickness of 3 μm after coating.
Then, on the liquid crystal layer, the black ink coating liquid is applied with a gravure plate so that the thickness after drying becomes 2.5 μm, and convex and cut characters are provided to form a background layer (background layer) Forming step).
Other than this, that is, the step of forming the heat-adhesive adhesive layer was the same as in Example 1 to prepare a liquid crystal laminate.
As a result, the obtained liquid crystal laminate exhibited the same effects as in Example 1, and in the portion where the background layer was formed, convex letters and blank letters could be read.
[0033]
In addition, although the convex character and undrawn character in Example 2 can be formed using gravure printing, flexographic printing, letterpress printing, screen printing, etc., among them, gravure printing and flexographic printing clear the image line. It is preferable because it is easy to form, and more preferably, it is formed by gravure printing.
Further, the whole surface coating (solid) may be formed by any of the above-described printing methods, and can also be performed by a method such as a knife coater or a bar coater.
[0034]
FIG. 6 is a cross-sectional schematic view showing another embodiment of the liquid crystal laminate of the present invention.
The liquid crystal laminate 210 is formed on a band-shaped base material 212, a liquid crystal layer 214 partially formed on the back surface side of the base material 212, and a surface opposite to the base material 212 side of the liquid crystal layer 214. The background layer 216 is formed, and a thermal adhesive layer 218 formed on the surface of the background layer 216 opposite to the liquid crystal layer 214 side.
The liquid crystal layer 214, the background layer 216, and the heat-adhesive adhesive layer 218 are formed so as to have substantially the same planar shape.
[0035]
The liquid crystal laminate 210 of this embodiment has substantially the same configuration as the liquid crystal laminate 10 of the above embodiment, but the liquid crystal layer 214, the background layer 216, and the heat-adhesive adhesive layer 218 have characters, pictures, etc. The image line consisting of is formed so as to constitute the image line by forming convex characters and blank characters. The liquid crystal layer 214 is formed such that an image line composed of characters, pictures, and the like is formed by printing a liquid crystal layer forming coating liquid that forms the liquid crystal layer 214 to form convex characters and blank characters. ing. The background layer 216 is formed so as to form an image line by printing with ink similar to the ink forming the background layer 16 of the above-described embodiment to form convex characters and blank characters. However, the liquid crystal layer 214 may be formed on the entire back surface of the base material 212. The background layer 216 has a concealing property and is formed so that the liquid crystal layer 214 exhibits glitter even when viewed from the surface side of the liquid crystal layer 214. The background layer 216 may be white. When the background layer 216 is white, almost all wavelengths of light that have passed through the liquid crystal layer 214 are reflected, so that the portion where the background layer 216 is formed looks whitish. When the adherend A is, for example, black, the portion where the background layer 216 is not formed exhibits green to blue glitter.
[0036]
In order to form the liquid crystal layer 214 composed of the cholesteric phase, it is necessary to heat to a temperature range in which the cholesteric phase is formed, and the cholesteric phase is formed even when the temperature at which the liquid crystal layer 214 is formed is higher or lower. do not do. When the coating film for forming a liquid crystal layer after coating is once heated to a temperature higher than the temperature range in which the cholesteric phase is formed, that is, to the temperature range in which the cholesteric phase is formed after being heated to the liquefaction temperature, the glittering property decreases. In addition, it is preferable that the drying after coating is not heated to the liquefaction temperature. Moreover, in the temperature region where the cholesteric phase is formed, it is advantageous in terms of brightness and the like when the temperature is set as high as possible. This is presumably due to the fact that the orientation (formation) of the cholesteric phase is performed promptly and reliably.
After the cholesteric phase is formed, it is necessary to fix the cholesteric phase by performing crosslinking at a temperature in the cholesteric phase formation temperature region in order to stably maintain the cholesteric phase as it is.
[0037]
Further, the thickness and material of the base material 212 are not particularly limited. However, if the thickness is too thin, it becomes difficult to apply the liquid crystal layer forming coating liquid or the background layer forming coating liquid. It is more preferable to have a thickness of about 25 μm or more because it easily enters and deforms. On the contrary, if it becomes too thick, it will be confused, and if it is attached to the surface of a curved surface such as a small part, Since it becomes difficult to wear, about 150 micrometers or less are more preferable.
Further, the background layer 216 may have a certain thickness or more when it is desired to provide a concealing effect, for example, preferably 1 μm or more, and more preferably about 2 to 5 μm.
The liquid crystal layer 214 only needs to have a thickness that allows the brightness to be visually recognized, and is preferably about 2 to 5 μm. If the thickness is less than 1 μm, the concentration may be reduced, which is not preferable.
[0038]
The heat-adhesive adhesive layer 218 is made of a heat-adhesive adhesive containing one or a plurality of resins of EVA resin, ionomer resin, acrylic resin, or the like on the background layer 216 or on the back surface of the liquid crystal layer 214 and the background layer 216. It is formed by coating.
The heat-adhesive adhesive containing these resins is applied to the back surface of the background layer 216 by being dissolved in a solvent as an emulsion or melted by heat.
The thickness of the coating is preferably 1 to 20 μm, more preferably 1 to 7 μm.
[0039]
For example, as shown in FIG. 7A, the liquid crystal laminate 210 has a surface of the liquid crystal layer 214 bonded to the adherend A by heating the surface of the heat-adhesive adhesive layer 218 and heating a hot plate or a heat roll. It is pressed from the side to activate the heat-adhesive adhesive layer 218 and is welded (hot stamped) to the adherend A such as a guarantee for a product or a product. Then, as shown in FIG. 7B, the liquid crystal layer 214 and the base material 212 are peeled off by welding, and the transfer body is composed of the liquid crystal layer 214 without the base material 212, the background layer 216, and the heat-adhesive adhesive layer 218. Sticks to the adherend A such as a product or a warranty card. Accordingly, the image line and the like are represented by the liquid crystal laminate 210 in which the liquid crystal layer 214, the background layer 216, and the thermal adhesive layer 218 are sequentially formed.
When the liquid crystal laminate 210 is hot stamped on the adherend A, the base material 212 and the liquid crystal layer 214 of the liquid crystal laminate 210 are peeled off so that the base material 212 can be removed. The configuration is as follows.
The adhesive strength between the base material 212 and the liquid crystal layer 214 is determined based on the adhesive strength between the other layers, that is, between the liquid crystal layer 214 and the background layer 216 and between the background layer 216 and the heat-adhesive adhesive layer 218, and each layer (liquid crystal layer 214, background The layer 216 and the heat-adhesive adhesive layer 218) are made weaker than the cohesive failure strength. As the method, for example, there is a method of adjusting the adhesive strength between the substrate 212 and the liquid crystal layer 214 without using any binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
In addition, when the liquid crystal laminate 210 is to be peeled off from the adherend A, the liquid crystal laminate 210 is destroyed, and the laminate is pasted on another fake product so that the fake cannot appear to be a genuine product. For example, the following configuration is adopted.
The cohesive failure strength between the background layer 216 and the liquid crystal layer 214 may be made different, or the adhesive strength between the liquid crystal layer 214, the background layer 216, and the heat-adhesive adhesive layer 218 may be made different. Needless to say, since the base material 212 is removed and adhered, it is extremely difficult to remove the liquid crystal laminate 210 from the adherend A without destroying it.
[0040]
Desirably, when the liquid crystal laminate 210 is peeled off from the adherend A, the liquid crystal laminate 210 may be destroyed, for example, the liquid crystal layer 214 may be coherently broken.
That is, when the liquid crystal laminate 210 is peeled off so as to prevent the laminate attached to the adherend A from being peeled off and attached to another fake adherend A, the liquid crystal laminate 210 Is configured to destroy. Therefore, for example, the following configuration may be used.
The liquid crystal layer 214 and the background layer 216 and / or the background layer 216 and the heat-adhesive adhesive layer 218 are configured to have different adhesive strengths or different cohesive fracture strengths. As the method, for example, there is a method of adjusting the adhesive strength between the liquid crystal layer 214 and the background layer 216 by using no binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
In this way, delamination occurs between the liquid crystal layer 214 and the background layer 216, or the liquid crystal layer 214, or the liquid crystal layer 214 and the background layer 216 are coherently broken, and the liquid crystal laminate 210 is attached to the adherend A. When the film is peeled off, the liquid crystal laminate 210 is destroyed, and the laminate cannot be replaced with another fake article.
[0041]
As described above, the liquid crystal laminate 210 has a background layer 216 formed on the back surface of the liquid crystal layer 214, so that it is impossible to produce a nearly authentic laminate by a normal printing technique or copying technique. Even if you have the printing technology, if you don't have knowledge about liquid crystal, especially liquid crystal composed of cholesteric phase, you can't get a stable liquid crystal layer with highly oriented cholesteric phase. It becomes difficult, and when the laminate is to be replaced, the laminate is destroyed, so that it is difficult to replace the laminate with a fake and make the fake adherend appear to be real.
[0042]
In the description of the embodiment, the background layer has been described. However, when the adherend is black or the like, the surface of the adherend has a function instead of the background layer. It does not have to be.
[0043]
FIG. 8 is an illustrative sectional view showing still another embodiment of the liquid crystal laminate of the present invention.
The liquid crystal laminate 310 includes a strip-shaped base material 312, a liquid crystal layer 314 partially formed on the back surface side of the base material 312, and a portion on the surface opposite to the base material 312 side of the liquid crystal layer 314. And a heat-adhesive adhesive layer 318 formed as a result.
The liquid crystal layer 314 and the heat-adhesive adhesive layer 318 are formed in substantially the same planar shape.
[0044]
The liquid crystal laminate 310 of this embodiment has substantially the same configuration as the liquid crystal laminate 10 of the above embodiment, but the liquid crystal layer 314 and the heat-adhesive adhesive layer 318 are image lines composed of characters, pictures, and the like. However, it is formed so as to constitute an image line by forming convex characters and blank characters. Note that the liquid crystal layer 314 and the heat-adhesive adhesive layer 318 can be formed over the entire surface (solid). The liquid crystal laminate 310 is obtained by bonding the surface of the heat-adhesive adhesive layer 318 to the adherend A, heating an appropriate hot plate or heat roll, and pressing it from the surface side of the liquid crystal layer 314. The layer 318 is activated, and the surface thereof is welded (hot stamped) to an adherend A such as a black product. Then, the liquid crystal layer 314 and the base material 312 are peeled off by welding, and a transfer body composed of the liquid crystal layer 314 without the base material 312 and the thermoadhesive adhesive layer 318 is attached to an adherend A such as a product.
In the liquid crystal laminate 310 of this embodiment, the adherend A is black and replaces the background layer 16 of the above embodiment, and the liquid crystal layer 314 exhibits glitter.
When the liquid crystal laminate 310 is hot stamped on the adherend A, the base material 312 and the liquid crystal layer 314 of the liquid crystal laminate 310 are peeled off so that the base material 312 can be removed. The configuration is as follows.
The adhesive strength between the base material 312 and the liquid crystal layer 314, the adhesive strength between the other layers, that is, the liquid crystal layer 314 and the heat-adhesive adhesive layer 318, and the aggregation of each layer (the liquid crystal layer 314 and the heat-adhesive adhesive layer 318) Configure to be weaker than the breaking strength. As the method, for example, there is a method of adjusting the adhesive strength between the substrate 312 and the liquid crystal layer 314 by using no binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
[0045]
Further, it can be used as a liquid crystal layer laminated continuous body wound with the surface of the base material 312 (the surface opposite to the surface on which the liquid crystal layer 314 is formed) as the outside and the thermal adhesive layer 318 as the inside. .
[0046]
【The invention's effect】
  According to the present invention, a liquid crystal laminate that is flexible, can be easily adhered along the surface of an adherend, can be produced at a relatively low cost, and can be used as a forgery prevention laminate.And liquid crystal laminated continuumCan be provided.
[Brief description of the drawings]
FIG. 1 is an illustrative sectional view of a liquid crystal laminate according to an embodiment of the present invention.
FIG. 2 is an illustrative view showing a molecular arrangement of a cholesteric phase.
FIG. 3 is an illustrative sectional view showing a method for pressure-bonding an adherend of a liquid crystal laminate.
FIG. 4 is a cross-sectional schematic view of a liquid crystal laminate according to another embodiment of the present invention.
5 is an illustrative sectional view showing a method for pressure-bonding the adherend of the liquid crystal laminate shown in FIG. 4; FIG.
FIG. 6 is a cross-sectional view of a liquid crystal laminate according to still another embodiment of the present invention.
7 is a cross-sectional schematic view showing a method for pressure-bonding the adherend of the liquid crystal laminate shown in FIG. 6;
FIG. 8 is an illustrative sectional view showing still another embodiment of the liquid crystal laminate of the present invention.
[Explanation of symbols]
10 110 210 310 Liquid crystal laminate
12 112 212 312 Base material
14 114 214 314 Liquid crystal layer
16 116 216 316 Background layer
18 118 218 318 Adhesive layer
A adherend
B foil stamping board

Claims (6)

A substrate;
A liquid crystal layer formed on the back side of the substrate;
It consists of a heat-adhesive adhesive layer formed on the surface opposite to the substrate side of the liquid crystal layer,
In the liquid crystal laminate formed so that the substrate and the liquid crystal layer are peeled off when the heat-adhesive adhesive layer is heated and adhered to the adherend ,
Using a PET film that has not been surface-treated on the substrate,
Applying liquid crystal molecules that can form a cholesteric phase directly on the back side of the PET film that has not been surface-treated,
The coated material is heated to a temperature at which the liquid crystal molecules form a cholesteric phase to form a cholesteric phase liquid crystal,
A liquid crystal laminate comprising a fixed cholesteric phase liquid crystal layer formed by fixing liquid crystal molecules by irradiating ultraviolet rays onto the coated material containing the cholesteric phase liquid crystal to fix the cholesteric phase liquid crystal . A substrate;
A liquid crystal layer formed on the back side of the substrate;
It consists of a heat-adhesive adhesive layer formed on the surface opposite to the substrate side of the liquid crystal layer,
In the liquid crystal laminate formed so that the substrate and the liquid crystal layer are peeled off when the heat-adhesive adhesive layer is heated and adhered to the adherend ,
Using a PET film that has not been surface-treated on the substrate,
Applying a mixture of liquid crystal molecules and a chiral compound capable of forming a nematic phase directly on the back side of the PET film that has not been surface-treated;
The coated material is heated to a temperature at which liquid crystal molecules mixed with the chiral compound form a cholesteric phase to form a cholesteric phase liquid crystal,
A liquid crystal laminate comprising a fixed cholesteric phase liquid crystal layer formed by fixing liquid crystal molecules by irradiating ultraviolet rays onto the coated material containing the cholesteric phase liquid crystal to fix the cholesteric phase liquid crystal . Forming a background layer on the side opposite to the substrate side of the liquid crystal layer,
The liquid crystal laminate according to claim 1, wherein the thermal adhesive layer is formed on a surface of the background layer opposite to the liquid crystal layer. A substrate;
A liquid crystal layer formed on the back side of the substrate;
It consists of a heat-adhesive adhesive layer formed on the surface opposite to the substrate side of the liquid crystal layer,
When the heat-adhesive adhesive layer is heated and adhered to the adherend, the substrate and the liquid crystal layer are formed so as to peel off ,
In the liquid crystal laminate continuum wound with the surface of the substrate as the outside and the thermal adhesive layer as the inside,
Using a PET film that has not been surface-treated on the substrate,
Applying liquid crystal molecules that can form a cholesteric phase directly on the back side of the PET film that has not been surface-treated,
The coated material is heated to a temperature at which the liquid crystal molecules form a cholesteric phase to form a cholesteric phase liquid crystal,
Forming a fixed cholesteric phase liquid crystal layer by cross-linking liquid crystal molecules by irradiating the coating material containing cholesteric phase liquid crystal with ultraviolet rays to fix the cholesteric phase liquid crystal.
Liquid crystal laminated continuum. A substrate;
A liquid crystal layer formed on the back side of the substrate;
It consists of a heat-adhesive adhesive layer formed on the surface opposite to the substrate side of the liquid crystal layer,
When the heat-adhesive adhesive layer is heated and adhered to the adherend, the substrate and the liquid crystal layer are formed so as to peel off ,
In the liquid crystal laminate continuum wound with the surface of the substrate as the outside and the thermal adhesive layer as the inside,
Using a PET film that has not been surface-treated on the substrate,
Applying a mixture of liquid crystal molecules and a chiral compound capable of forming a nematic phase directly on the back side of the PET film that has not been surface-treated;
The coated material is heated to a temperature at which liquid crystal molecules mixed with the chiral compound form a cholesteric phase to form a cholesteric phase liquid crystal,
A liquid crystal laminated continuum obtained by forming a fixed cholesteric phase liquid crystal layer by cross-linking liquid crystal molecules by irradiating ultraviolet rays onto the coated material containing cholesteric phase liquid crystal to fix the cholesteric phase liquid crystal. Forming a background layer on the side opposite to the substrate side of the liquid crystal layer,
The liquid crystal laminated continuum according to claim 4 or 5, wherein the thermal adhesive layer is formed on a surface of the background layer opposite to the liquid crystal layer side.

Images