JP4101419B2 - Reversible thermosensitive recording medium and reversible thermosensitive recording method using the same - Google Patents

Description

【００５１】
一般式（１）で表されるカルボン酸化合物の具体例を、下記表１〜１３にｐ、ｑ、ｒ、ｓ、Ａ、Ｂ、Ｘ、Ｙの数または構造で示す。
【００５２】
【表１】

【００５３】
【表２】

【００５４】
【表３】

【００５５】
【表４】

【００５６】
【表５】

【００５７】
【表６】

【００５８】
【表７】

【００５９】
【表８】

【００６０】
【表９】

【００６１】
【表１０】

【００６２】
【表１１】

【００６３】
【表１２】

【００６４】
【表１３】

【００６５】
また、顕色剤に用いるカルボン酸化合物としては、下記一般式（２）で表される化合物が例示できる。
【化２】

【００６６】
一般式（２）で表されるカルボン酸化合物の具体例を、下記表１４〜１８にｎ、ｐ、ｑ、ｒ、Ｒ、Ｘ、Ｙの数または構造で示す。
【００６７】
【表１４】

【００６８】
【表１５】

【００６９】
【表１６】

【００７０】
【表１７】

【００７１】
【表１８】

【００７２】
顕色剤には、分子間凝集力を制御する構造を持つフェノール化合物も好ましく用いられる。これには、例えば下記一般式（３）で表されるフェノール化合物が例示できる。
【化３】

【００７３】
一般式（３）で表されるフェノール化合物の具体例を下記表１９〜２５にｐ、ｑ、ｒ、ｓ、Ｘ、Ａ、Ｙ、Ｚの数または構造で示す。但し、これらのそれぞれの具体例においてフェノール部のｎは１〜３であり、例えば、４−ヒドロキシフェニル、３−ヒドロキシフェニル、２−ヒドロキシフェニル、２，４−ジヒドロキシフェニル、３，４−ジヒドロキシフェニルまたは３，４，５−トリヒドロキシフェニルなどの水酸基を少なくとも一つ以上有するフェニル基である。このフェニル基には、水酸基以外の置換基を有していてもよい。また、フェノール性水酸基を有するものであれば、他の芳香環であってもよい。
【００７４】
【表１９】

【００７５】
【表２０】

【００７６】
【表２１】

【００７７】
【表２２】

【００７８】
【表２３】

【００７９】
【表２４】

【００８０】
【表２５】

【００８１】
本発明で用いる発色剤は電子供与性を示すものであり、それ自体無色あるいは淡色の染料前駆体（ロイコ染料）であり、とくに限定されず、従来公知のもの、たとえばフタリド系化合物、アザフタリド系化合物、フルオラン系化合物、フェノチアジン系化合物、ロイコオーラミン系化合物などから選択できる。その発色剤を以下に示す。
【００８２】
本発明に用いる好ましい発色剤として下記の一般式の化合物がある。
【化４】

【化５】

（ただし、Ｒ₁は水素原子又は炭素数１〜４のアルキル基、Ｒ₂は炭素数１〜６アルキル基、シクロアキル基または置換されていてもよいフェニル基を示す。フェニル基に対する置換基としては、メチル基、エチル基などのアルキル基、メトキシ基、エトキシ基などのアルコキシ基またはハロゲン原子等が示される。Ｒ₃は水素原子、炭素数１〜２のアルキル基、アルコキシ基またはハロゲン原子を表す。Ｒ₄は水素原子、メチル基、ハロゲン原子または置換されていても良いアミノ基を表す。アミノ基に対する置換基としては、例えば、アルキル基、置換されていても良いアリール基、置換されていても良いアラルキル基を示す。ここでの置換基はアルキル基、ハロゲン原子、アルコキシ基などである。）
【００８３】
このような発色剤の具体例としては、例えば次の化合物が挙げられる。
２−アニリノ−３−メチル−６−ジエチルアミノフルオラン、２−アニリノ−３−メチル−６−ジ（ｎ−ブチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−ｎ−プロピル−Ｎ−メチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−イソプロピル−Ｎ−メチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−イソブチル−Ｎ−メチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−ｎ−アミル−Ｎ−メチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−ｓｅｃ−ブチル−Ｎ−メチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−ｎ−アミル−Ｎ−エチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−ｉｓｏ−アミル−Ｎ−エチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−ｎ−プロピル−Ｎ−イソプロピルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−シクロヘキシル−Ｎ−メチルアミノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−アニリノ−３−メチル−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、２−（ｍ−トリクロロメチルアニリノ）−３−メチル−６−ジエチルアミノフルオラン、２−（ｍ−トリフルロロメチルアニリノ）−３−メチル−６−ジエチルアミノフルオラン、２−（ｍ−トリクロロメチルアニリノ）−３−メチル−６−（Ｎ−シクロヘキシル−Ｎ−メチルアミノ）フルオラン、２−（２，４−ジメチルアニリノ）−３−メチル−６−ジエチルアミノフルオラン、２−（Ｎ−エチル−ｐ−トルイジノ）−３−メチル−６−（Ｎ−エチルアニリノ）フルオラン、２−（Ｎ−エチル−ｐ−トルイジノ）−３−メチル−６−（Ｎ−プロピル−ｐ−トルイジノ）フルオラン、２−アニリノ−６−（Ｎ−ｎ−ヘキシル−Ｎ−エチルアミノ）フルオラン、２−（ｏ−クロロアニリノ）−６−ジエチルアミノフルオラン、２−（ｏ−クロロアニリノ）−６−ジブチルアミノフルオラン、２−（ｍ−トリフロロメチルアニリノ）−６−ジエチルアミノフルオラン、２−（ｐ−アセチルアニリノ）−６−（Ｎ−ｎ−アミル−Ｎ−ｎ−ブチルアミノ）フルオラン、２−ベンジルアミノ−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−ベンジルアミノ−６−（Ｎ−メチル−２，４−ジメチルアニリノ）フルオラン、２−ベンジルアミノ−６−（Ｎ−エチル−２，４−ジメチルアニリノ）フルオラン、２−ベンジルアミノ−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、２−ベンジルアミノ−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−（ジ−ｐ−メチルベンジルアミノ）−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−（α−フェニルエチルアミノ）−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−メチルアミノ−６−（Ｎ−メチルアニリノ）フルオラン、２−メチルアミノ−６−（Ｎ−エチルアニリノ）フルオラン、２−メチルアミノ−６−（Ｎ−プロピルアニリノ）フルオラン、２−エチルアミノ−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、２−メチルアミノ−６−（Ｎ−メチル−２，４−ジメチルアニリノ）フルオラン、２−エチルアミノ−６−（Ｎ−エチル−２，４−ジメチルアニリノ）フルオラン、２−ジメチルアミノ−６−（Ｎ−メチルアニリノ）フルオラン、２−ジメチルアミノ−６−（Ｎ−エチルアニリノ）フルオラン、２−ジエチルアミノ−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、２−ジエチルアミノ−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−ジプロピルアミノ−６−（Ｎ−メチルアニリノ）フルオラン、２−ジプロピルアミノ−６−（Ｎ−エチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−メチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−エチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−プロピルアニリノ）フルオラン、２−アミノ−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、２−アミノ−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−アミノ−６−（Ｎ−プロピル−ｐ−トルイジノ）フルオラン、２−アミノ−６−（Ｎ−メチル−ｐ−エチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−エチル−ｐ−エチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−プロピル−ｐ−エチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−メチル−２，４−ジメチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−エチル−２，４−ジメチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−プロピル−２，４−ジメチルアニリノ）フルオラン、２−アミノ−６−（Ｎ−メチル−ｐ−クロロアニリノ）フルオラン、２−アミノ−６−（Ｎ−エチル−ｐ−クロロアニリノ）フルオラン、２−アミノ−６−（Ｎ−プロピル−ｐ−クロロアニリノ）フルオラン、２，３−ジメチル−６−ジメトルアミノフルオラン、３−メチル−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−クロロ−６−ジエチルアミノフルオラン、２−ブロモ−６−ジエチルアミノフルオラン、２−クロロ−６−ジプロピルアミノフルオラン、３−クロロ−６−シクロヘキシルアミノフルオラン、３−ブロモ−６−シクロヘキシルアミノフルオラン、２−クロロ−６−（Ｎ−エチル−Ｎ−イソアミルアミノ）フルオラン、２−クロロ−３−メチル−６−ジエチルアミノフルオラン、２−アニリノ−３−クロロ−６−ジエチルアミノフルオラン、２−（ｏ−クロロアニリノ）−３−クロロ−６−シクロヘキシルアミノフルオラン、２−（ｍ−トリフロロメチルアニリノ）−３−クロロ−６−ジエチルアミノフルオラン、２−（２，３−ジクロロアニリノ）−３−クロロ−６−ジエチルアミノフルオラン、１，２−ベンゾ−６−ジエチルアミノフルオラン、１，２−ベンゾ−６−（Ｎ−エチル−Ｎ−イソアミルアミノ）フルオラン、１，２−ベンゾ−６−ジブチルアミノフルオラン、１，２−ベンゾ−６−（Ｎ−メチル−Ｎ−シクロヘキシルアミノ）フルオラン、１，２−ベンゾ−６−（Ｎ−エチル−Ｎ−トルイジノ）フルオラン、その他。
【００８４】
本発明において好ましく用いられる他の発色剤の具体例を示すと、以下の通りである。
２−アニリノ−３−メチル−６−（Ｎ−２−エトキシプロピル−Ｎ−エチルアミノ）フルオラン、２−（ｐ−クロロアニリノ）−６−（Ｎ−ｎ−オクチルアミノ）フルオラン、２−（ｐ−クロロアニリノ）−６−（Ｎ−ｎ−パルミチルアミノ）フルオラン、２−（ｐ−クロロアニリノ）−６−（ジ−ｎ−オクチルアミノ）フルオラン、２−ベンゾイルアミノ−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−（ｏ−メトキシベンゾイルアミノ）−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、２−ジベンジルアミノ−４−メチル−６−ジエチルアミノフルオラン、２−ジベンジルアミノ−４−メトキシ−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、２−ジベンジルアミノ−４−メチル−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−（α−フェニルエチルアミノ）−４−メチル−６−ジエチルアミノフルオラン、２−（ｐ−トルイジノ）−３−（ｔ−ブチル）−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、２−（ｏ−メトキシカルボニルアミノ）−６−ジエチルアミノフルオラン、２−アセチルアミノ−６−（Ｎ−メチル−ｐ−トルイジノ）フルオラン、３−ジエチルアミノ−６−（ｍ−トリフロロメチルアニリノ）フルオラン、４−メトキシ−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−エトキシエチルアミノ−３−クロロ−６−ジブチルアミノフルオラン、２−ジベンジルアミノ−４−クロロ−６−（Ｎ−エチル−ｐ−トルイジノ）フルオラン、２−（α−フェニルエチルアミノ）−４−クロロ−６−ジエチルアミノフルオラン、２−（Ｎ−ベンジル−ｐ−トリフロロメチルアニリノ）−４−クロロ−６−ジエチルアミノフルオラン、２−アニリノ−３−メチル−６−ピロリジノフルオラン、２−アニリノ−３−クロロ−６−ピロリジノフルオラン、２−アニリノ−３−メチル−６−（Ｎ−エチル−Ｎ−テトラヒドロフルフリルアミノ）フルオラン、２−メシジノ−４’，５’−ベンゾ−６−ジエチルアミノフルオラン、２−（ｍ−トリフロロメチルアニリノ）−３−メチル−６−ピロリジノフルオラン、２−（α−ナフチルアミノ）−３，４ベンゾ−４’−ブロモ−６−（Ｎ−ベンジル−Ｎ−シクロヘキシルアミノ）フルオラン、２−ピペリジノ−６−ジエチルアミノフルオラン、２−（Ｎ−ｎ−プロピル−ｐ−トリフロロメチルアニリノ）−６−モルフォリノフルオラン、２−（ジ−Ｎ−ｐ−クロロフェニル−メチルアミノ）−６−ピロリジノフルオラン、２−（Ｎ−ｎ−プロピル−ｍ−トリフロロメチルアニリノ）−６−モルフォリノフルオラン、１，２−ベンゾ−６−（Ｎ−エチル−Ｎ−ｎ−オクチルアミノ）フルオラン、１，２−ベンゾ−６−ジアリルアミノフルオラン、１，２−ベンゾ−６−（Ｎ−エトキシエチル−Ｎ−エチルアミノ）フルオラン、ベンゾロイコメチレンブルー、２−［３，６−ビス（ジエチルアミノ）］−６−（ｏ−クロロアニリノ）キサンチル安息香酸ラクタム、２−［３，６−ジエチルアミノ）］−９−（ｏ−クロロアニリノ）キサンチル安息香酸ラクタム、３，３−ビス（ｐ−ジメチルアミノフェニル）−フタリド、３、３−ビス（ｐ−ジメチルアミノフェニル）−６−ジメチルアミノフタリド（別名クリスタルバイオレットラクトン）、３，３−ビス−（ｐ−ジメチルアミノフェニル）−６−ジエチルアミノフタリド、３，３−ビス−（ｐ−ジメチルアミノフェニル）−６−クロロフタリド、３，３−ビス−（ｐ−ジブチルアミノフェニル）フタリド、３−（２−メトキシ−４−ジメチルアミノフェニル）−３−（２−ヒドロキシ−４，５−ジクロロフェニル）フタリド、３−（２−ヒドロキシ−４−ジメチルアミノフェニル）−３−（２−メトキシ−５−クロロフェニル）フタリド、３−（２−ヒドロキシ−４−ジメトキシアミノフェニル）−３−（２−メトキシ−５−クロロフェニル）フタリド、３−（２−ヒドロキシ−４−ジメチルアミノフェニル）−３−（２−メトキシ−５−ニトロフェニル）フタリド、３−（２−ヒドロキシ−４−ジエチルアミノフェニル）−３−（２−メトキシ−５−メチルフェニル）フタリド、３−（２−メトキシ−４−ジメチルアミノフェニル）−３−（２−ヒドロキシ−４−クロロ−５−メトキシフェニル）フタリド、３，６−ビス（ジメチルアミノ）フルオレンスピロ（９，３’）−６’−ジメチルアミノフタリド、３−（１−エチル−２−メチルインドール−３−イル）−３−（２−エトキシ−４−ジエチルアミノフェニル）−４−アザフタリド、３−（１−オクチル−２−メチルインドール−３−イル）−３−（２−エトキシ−４−ジエチルアミノフェニル）−４−アザフタリド、３−（１−エチル−２−メチルインドール−３−イル）−３−（２−エトキシ−４−ジエチルアミノフェニル）−７−アザフタリド、３，３−ビス（２−エトキシ−４−ジエチルアミノフェニル）−４−アザフタリド、３，３−ビス（２−エトキシ−４−ジエチルアミノフェニル）−７−アザフタリド、６’−クロロ−８’−メトキシ−ベンゾインドリノ−スピロピラン、６’−ブロモ−２’−メトキシ−ベンゾインドリノ−スピロピラン、その他。
【００８５】
本発明の可逆性感熱記録媒体は、加熱温度および／または加熱後の冷却速度の違いにより、相対的に発色した状態と消色した状態を形成し得るものである。この基本的な発色・消色現象を説明する。図１はこの記録媒体の発色濃度と温度との関係を示したものである。はじめ消色状態（Ａ）にある記録媒体を昇温していくと、溶融し始める温度Ｔ₁で発色が起こり、溶融発色状態（Ｂ）となる。溶融発色状態（Ｂ）から急冷すると、発色状態のまま室温に下げることができ、固まった発色状態（Ｃ）となる。この発色状態が得られるかどうかは、溶融状態からの降温の速度に依存しており、徐冷では降温の過程で消色が起き、はじめと同じ消色状態（Ａ）あるいは急冷発色状態（Ｃ）より相対的に濃度の低い状態が形成される。一方、急冷発色状態（Ｃ）をふたたび昇温していくと、発色温度より低い温度Ｔ₂で消色が起き（ＤからＥ）、ここから降温するとはじめと同じ消色状態（Ａ）に戻る。実際の発色温度、消色温度は、用いる顕色剤と発色剤の組合せにより変化するので、目的に合わせて選択できる。また、溶融発色状態の濃度と急冷したときの発色濃度は、必ずしも一致するものではなく、異なる場合もある。
【００８６】
本発明の可逆性感熱記録媒体では、溶融発色状態（Ｂ）から急冷して得られた発色状態（Ｃ）は顕色剤と発色剤が分子同士で接触反応し得る状態で混合された状態であり、これは固体状態を形成していることが多い。この状態は顕色剤と発色剤が凝集して発色を保持した状態であり、この凝集構造の形成により発色が安定化していると考えられる。
一方、消色状態は両者が相分離した状態である。この状態は少なくとも一方の化合物の分子が集合してドメインを形成したり結晶化した状態であり、凝集あるいは結晶化することにより発色剤と顕色剤が分離して安定化した状態であると考えられる。本発明では多くの場合、両者が相分離し顕色剤が結晶化することによってより完全な消色が起きる。図１に示した溶融状態から徐冷による消色および発色状態からの昇温による消色は、いずれもこの温度で凝集構造が変化し相分離や顕色剤の結晶化が起きているものと考えられる。
【００８７】
本発明の可逆性感熱記録媒体の発色記録の形成は、サーマルヘッドなどによりいったん溶融混合する温度に加熱し、急冷すればよい。また、消色は加熱状態から徐冷する方法と発色温度よりやや低い温度に加熱する方法の二つである。しかし、これらは両者が相分離したり、少なくとも一方が結晶化する温度に一時的に保持するという意味で同じである。発色状態の形成で急冷するのは、この相分離温度または結晶化温度に保持しないようにするためである。ここにおける急冷と徐冷はひとつの組成物に対して相対的なものであり、その境界は発色剤と顕色剤の組合せにより変化する。
【００８８】
可逆性感熱記録層中の発色剤と顕色剤の割合は、使用する化合物の組合せにより適切な範囲が変化するが、おおむねモル比で発色剤１に対し顕色剤が０．１〜２０の範囲であり、好ましくは０．２から１０の範囲である。この範囲より顕色剤が少なくても多くても発色状態の濃度が低下し、問題となる。
【００８９】
記録層は発色剤と顕色剤が存在していればどのようなものでもよいが、一般的にはバインダー樹脂中に発色剤と顕色剤が細かく均一に分散した状態が用いられる。発色剤と顕色剤は個々に粒子を形成していてもよいが、より好ましくは複合された粒子として分散された状態を形成するのが好ましい。これは発色剤と顕色剤をいったん溶融したり溶解することによつて達成できる。このような記録層の形成は、各材料をそれぞれ溶剤中で分散溶解したのち混合した液、あるいは各材料を混合して溶剤中で分散または溶解した液を支持体上に塗布し、乾燥することによって行なわれる。発色剤と顕色剤はマイクロカプセル中に内包して用いることもできる。
【００９０】
本発明の可逆性感熱記録媒体には、必要に応じて記録層の塗布特性を改善したり制御するための添加剤を用いることができる。これらの添加剤には、たとえば分散剤、界面活性剤、導電剤、充填剤、滑剤、酸化防止剤、光安定化剤、紫外線吸収剤、発色安定化剤、他の消色促進剤などがある。
【００９１】
記録層の形成に用いられるバインダー樹脂としては、たとえばポリ塩化ビニル、ポリ酢酸ビニル、塩化ビニル酢酸ビニル共重合体、エチルセルロース、ポリスチレン、スチレン系共重合体、フェノキシ樹脂、ポリエステル、芳香族ポリエステル、ポリウレタン、ポリカーボネート、ポリアクリル酸エステル、ポリメタクリル酸エステル、アクリル酸系共重合体、マレイン酸系共重合体、ポリビニルアルコール、変性ポリビニルアルコール、ヒドロキシエチルセルロース、カルボキシメチルセルロース、デンプン類などがある。これらのバインダー樹脂の役割は、組成物の各材料が記録消去の熱印加によって片寄ることなく均一に分散した状態を保つことにある。したがって、バインダー樹脂には耐熱性の高い樹脂を用いることが好ましい。また、硬化性樹脂を用いてもよい。
【００９２】
硬化性樹脂としては、たとえば架橋剤およびこの架橋剤と反応する活性基を有する樹脂の組み合わせであり、熱、電子線、紫外線等により架橋硬化される樹脂である。
熱硬化で用いられる樹脂は、たとえばフェノキシ樹脂、ポリビニルブチラール樹脂、セルロースアセテートプロピオネート、セルロースアセテートブチレートなど、水酸基、カルボキシル基など架橋剤と反応する基を持つ樹脂、または水酸基、カルボキシル基などを持つモノマーとそれ以外のモノマーを共重合した樹脂がある。共重合樹脂には、たとえば塩ビ系、アクリル系、スチレン系などの樹脂があり、具体的には塩化ビニル−酢酸ビニル−ビニルアルコール共重合体、塩化ビニル−酢酸ビニル−ヒドロキシプロピルアクリレート共重合体、塩化ビニル−酢酸ビニル−無水マレイン酸共重合体等が例示できる。
【００９３】
熱架橋の架橋剤としては、たとえばイソシアネート類、アミン類、フェノール類、エポキシ化合物等が挙げられる。たとえば、イソシアネート類としては、イソシアネート基を複数持つポリイソシアネート化合物であり、具体的にはヘキサメチレンジイソシアネート（ＨＤＩ）、トルエンジイソシアネート（ＴＤＩ）、キシリレンジイソシアネート（ＸＤＩ）等、およびこれらのトリメチロールプロパンなどによるアダクトタイプ、ビュレットタイプ、イソシアヌレートタイプおよびブロック化イソシアネート類等が挙げられる。架橋剤の樹脂に対する添加量としては、樹脂中の含まれる活性基の数に対する架橋剤の官能基の比が０．０１〜２．０が好ましく、これ以下では熱強度が不足してしまい、またこれ以上添加すると発色・消色特性に悪影響をおよぼす。またさらに、架橋促進剤としてこの種の反応に用いられる触媒を用いてもよい。架橋促進剤としては、たとえば１，４−ジアザービシクロ〔２，２，２〕オクタンなどの３級アミン類、有機すず化合物などの金属化合物などが挙げられる。
【００９４】
次に、電子線および紫外線硬化の際に用いられるモノマーとしては、たとえば以下のものが挙げられる。
単官能性モノマーの例
メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ｎ−ブチル、メタクリル酸ｉ−ブチル、メタクリル酸ｔ−ブチル、メタクリル酸２−エチルヘキシル、メタクリル酸ラウリル、メタクリル酸トリデシル、メタクリル酸ステアリル、メタクリル酸シクロヘキシル、メタクリル酸ベンジル、メタクリル酸、メタクリル酸２−ヒドロキシエチル、メタクリル酸２−ヒドロキシプロピル、メタクリル酸ジメチルアミノエチル、メタクリル酸ジメチルアミノエチルメチルクロライド塩、メタクリル酸ジエチルアミノエチル、メタクリル酸グリシジル、メタクリル酸テトラヒドロフルフリル、メタクリル酸アリル、ジメタクリル酸エチレングリコール、ジメタクリル酸トリエチレングリコール、ジメタクリル酸テトラエチレングリコール、ジメタクリル酸１，３−ブチレングリコール、ジメタクリル酸１，６−ヘキサンジオール、トリメタクリル酸トリメチロールプロパン、メタクリル酸２−エトキシエチル、２−エチルヘキシルアクリレート、２−エトキシエチルアクリレート、２−エトキシエトキシエチルアクリレート、２−ヒドロキシエチルアクリレート、２−ヒドロキシプロピルアクリレート、ジシクロペンテニルエチルアクリレート、Ｎ−ビニルピロリドン、酢酸ビニル等。
【００９５】
２官能性モノマーの例
１，４−ブタンジオールジアクリレート、１，６−ヘキサンジオールジアクリレート、１，９−ノナンジオールジアクリレート、ネオペンチルグリコールジアクリレート、テトラエチレングリコールジアクリレート、トリプロピレングリコールジアクリレート、ポリプロピレングリコールジアクリレート、ビスフェノールＡエチレンオキサイド付加物ジアクリレート、グリセリンメタクリレートアクリレート、ネオペンチルグリコールのプロピレンオキサイド２モル付加物のジアクリレート、ジエチレングリコールジアクリレート、ポリエチレングリコール（４００）ジアクリレート、ヒドロキシピバリン酸とネオペンチルグリコールのエステルのジアクリレート、２，２−ビス（４−アクリロキシジエトキシフェニル）プロパン、ネオペンチルグリコールジアジペートのジアクリレート、ヒドロキシピバリン酸ネオペンチルグリコールのε−カプロラクトン付加物のジアクリレート、２−（２−ヒドロキシ−１，１−ジメチルエチル）−５−ヒドロキシメチル−５−エチル−１，３−ジオキサンジアクリレート、トリシクロデカンジメチロールジアクリレート、トリシクロデカンジメチロールジアクリレートのε−カプロラクトン付加物、１，６−ヘキサンジオールのグリシジルエーテルのジアクリレート等。
【００９６】
多官能性モノマーの例
トリメチロールプロパントリアクリレート、グリセリンプロピレンオキサイド付加アクリレート、トリスアクリロイルオキシエチルフォスフェート、ペンタエリスリトールアクリレート、トリメチロールプロパンのプロピレンオキサイド３モル付加物のトリアクリレート、ジペンタエリスリトール・ポリアクリレート、ジペンタエリスリトールのカプロラクトン付加物のポリアクリレート、プロピオン酸ジペンタエリスリトールトリアクリレート、ヒドロキシピバルアルデヒド変性ジメチロールプロパントリアクリレート、プロピオン酸ジペンタエリスリトールのテトラアクリレート、ジトリメチロールプロパンテトラアクリレート、プロピオン酸ジペンタエリスリトールのペンタアクリレート、ジペンタエリスリトールヘキサアクリレート、ジペンタエリスリトールヘキサアクリレートのε−カプロラクトン付加物等。
【００９７】
オリゴマーの例
ビスフェノールＡ−ジエポキシアクリル酸付加物等。
【００９８】
また、紫外線を用いて架橋させる場合には、次のような光重合開始剤、光重合促進剤を用いる。
光重合開始剤の例としては、イソブチルベンゾインエーテル、イソプロピルベンゾインエーテル、ベンゾインエチルエーテル、ベンゾインメチルエーテル等のベンゾインエーテル類；１−フェニル−１，２−プロパンジオン−２−（ｏ−エトキシカルボニル）オキシム等のα−アシロキシムエステル；２，２−ジメトキシ−２−フェニルアセトフェノン、ベンジル、ヒドロキシシクロヘキシルフェニルケトン等のベンジルケタール類；ジエトキシアセトンフェノン、２−ヒドロキシ−２−メチル−１−フェニルプロパン−１−オン等のアセトフェノン誘導体；ベンゾフェノン、１−クロロチオキサントン、２−クロロチオキサントン、イソプロピルチオキサントン、２−メチルチオキサントン、２−クロロベンゾフェノン等のケトン類が挙げられる。これらの光重合開始剤は、単独でまたは２種類以上併用して使用される。添加量としてはモノマーまたはオリゴマー１重量部に対して０．００５〜１．０重量部が好ましく、さらに好ましくは０．０１〜０．５重量部である。
【００９９】
光重合促進剤としては、芳香族系の第３アミンや脂肪族系アミンがある。具体的には、ｐ−ジメチルアミノ安息香酸イソアミルエステル、ｐ−ジメチルアミノ安息香酸エチルエステル等が挙げられる。これらの光重合促進剤は、単独でまたは２種類以上併用して使用される。添加量としては光重合開始剤１重量部に対して０．１〜５重量部が好ましく、さらに好ましくは０．３〜３重量部である。
【０１００】
紫外線照射の際の光源としては、水銀ランプ、メタルハライドランプ、ガリウムランプ、水銀キセノンランプ、フラッシュランプなどがあるが、前記した光重合開始剤および光重合促進剤の紫外線吸収波長に対応した発光スペクトルを有する光源を使用すればよい。また、紫外線照射条件としては、樹脂を架橋させるために必要な照射エネルギーに応じてランプ出力、搬送速度を決めればよい。
【０１０１】
また、電子線照射装置としては、照射面積、照射線量などの条件に応じて走査形、非走査形いずれかを選べは良く、照射条件としては樹脂を架橋するのに必要な線量に応じて、電子流、照射幅、搬送速度を決めれば良い。
【０１０２】
本発明の可逆性感熱記録媒体は、基本的には支持体上に上記の可逆性感熱記録層が設けられ、さらにその上に画像印刷層が積層されて、可逆性感熱記録層と画像印刷層が面内において重なり合っているものであるが、印字時のヘッドマッチング性や繰り返し耐久性の向上のために、保護層を可逆性感熱記録層および／または画像印刷層上に設けることが好ましい。
【０１０３】
本発明における画像印刷層は、顔料、染料を含んだ印刷インキをオフセット、グラビア、スクリーン印刷等で設けることができる。なお、印刷インキのビヒクルには熱硬化性樹脂、ＵＶ硬化性樹脂、ＥＢ硬化性樹脂を用いて、接着性、耐熱性、耐久性を考慮することが好ましい。
【０１０４】
保護層としては、感熱記録媒体で一般に用いられているポリビニルアルコール、ポリ（メタ）アクリル酸エステルその他の樹脂を使用することができるが、特に可逆性感熱記録層用保護層としては硬化性樹脂を含有することが好ましく、また画像印刷層用保護層としては耐熱性樹脂からなるものが好ましい。
【０１０５】
硬化性樹脂は前記したように、たとえば架橋剤およびこの架橋剤と反応する活性基を有する樹脂の組み合わせであり、熱、電子線、紫外線等により架橋される樹脂であって、前記記録層で述べられている硬化性樹脂と同様熱硬化性樹脂、紫外線硬化樹脂、電子硬化樹脂などが用いられる。
【０１０６】
また、耐熱性樹脂としては、ポリイミド、ポリアミドイミド等が挙げられる。
【０１０７】
また、保護層中には紫外線吸収剤、無機または／および有機フィラー、滑剤などの添加剤を含有させることができる。なお、保護層に用いる樹脂としては、前記の硬化性樹脂などの他に、ポリビニルアルコール、スチレン無水マレイン酸共重合体、カルボキシ変性ポリエチレン、メラミン−ホルムアルデヒド樹脂、尿素−ホルムアルデヒド樹脂が挙げられる。
【０１０８】
記録層または、画像印刷層と保護層の接着性向上、保護層の塗布による記録層の変質防止、保護層中の添加剤の記録層への移行を防止する目的で、記録層又は画像印刷層と保護層の間に中間層を設けることも好ましい。また、記録層の上に設置される保護層、中間層には酸素透過性の低い樹脂を用いることが好ましい。記録層中の発色剤および顕色剤の酸化を防止または低減することが可能になる。
【０１０９】
また、印加した熱を有効に利用するため、支持体と記録層の間に断熱性のアンダーコート層（断熱層）を設けることができる。断熱層は、有機または無機の微小中空体粒子をバインダー樹脂を用いて塗布することにより形成できる。支持体と記録層の接着性の改善や支持体への記録層材料の浸透防止を目的としたアンダーコート層を設けることもできる。
【０１１０】
中間層、アンダーコート層には、前記の記録層用の樹脂と同様の樹脂を用いることができる。また、保護層、中間層、記録層およびアンダーコート層には、炭酸カルシウム、炭酸マグネシウム、酸化チタン、酸化ケイ素、水酸化アルミニウム、カオリン、タルクなどの無機フィラーおよび／または各種有機フィラーを含有させることができる。その他、滑剤、界面活性剤、分散剤などを含有させることもできる。
【０１１１】
本発明の可逆性感熱記録媒体を用いて発色画像を形成させるためには、いったん発色温度以上に加熱したのち急冷されるようにすればよい。具体的には、例えばサーマルヘッドやレーザー光で短時間加熱すると記録層が局部的に加熱されるため、直ちに熱が拡散し急激な冷却が起こり、発色状態が固定できる。一方、消色させるためには適当な熱源を用いて比較的長時間加熱し冷却するか、発色温度よりやや低い温度に一時的に加熱すればよい。長時間加熱すると記録媒体の広い範囲が昇温し、その後の冷却は遅くなるため、その過程で消色が起きる。この場合の加熱方法には、熱ローラー、熱スタンプ、熱風などを用いてもよいし、サーマルヘッドを用いて長時間加熱してもよい。記録層を消色温度域に加熱するためには、例えばサーマルヘッドへの印加電圧やパルス幅を調節することによって、印加エネルギーを記録時よりやや低下させればよい。この方法を用いれば、サーマルヘッドだけで記録・消去ができ、いわゆるオーバーライトが可能になる。もちろん、熱ローラー、熱スタンプによって消色温度域に加熱して消去することもできる。
【０１１２】
【実施例】
以下、実施例によって本発明をさらに詳しく説明する。なお、実施例中の「部」および「％」はいずれも重量を基準とするものである。
【０１１３】
実施例１
〈記録層の作成〉
１）２−アニリノ−３−メチル−６−ジブチルアミノフルオラン ２部
２）下記の構造の顕色剤 ８部
【化６】

３）フェノキシ樹脂（ユニオンカーバイド社製ＰＫＨＨ）
の１５％テトラヒドロフラン（ＴＨＦ）溶液 １５０部
上記組成物をボールミルを用いて粒径１〜４μｍまで粉砕分散した。得られた分散液に日本ポリウレタン社製コロネートＨＬ（アダクト型ヘキサメチレンジイソシアネート ７５％酢酸エチル溶液）２０部を加え、良く撹拌し記録層塗布液を調製した。上記組成の記録層塗布液を、厚さ１００μｍのポリエステルフィルム上にワイヤーバーを用い塗布し、８０℃で乾燥した後、１００℃１０分、６０℃２４時間加熱して、膜厚約６．０μｍの記録層を設けた。
【０１１４】
〈保護層の作成〉
１）ウレタンアクリレート系紫外線硬化性樹脂 １０部
（大日本インキ社製Ｃ７−１５７）
２）酢酸エチル ９０部
上記組成の保護層液を、上記記録層上にワイヤーバーを用いて塗工した後、照射エネルギー８０Ｗ／ｃｍの紫外線ランプ下を９ｍ／分の搬送速度で通して硬化して膜厚３μｍの保護層を設け、可逆性感熱記録媒体を作製した。
【０１１５】
作製した記録媒体に対して、図２にその模式断面が示されるように、保護層４上にオフセット印刷機（ＫＯＭＯＲＩ社製）を用いて、東洋インキ社製ＵＶインキで、図３のようなデザインを黒印刷し、さらに同社製のＯＰインキで表面保護層を設け、カード形状に加工した。得られたカード状記録媒体について、九州松下電器社製プリンターＲ３０００シリーズで消去、印字を繰り返したところ、画像ａ１、ａ２を自由に印字しても、黒発色のためどこが可逆性部分なのか見分けることはできなかった。
【０１１６】
実施例２
実施例１において、図３のようなデザインを黒印刷する代わりに、図７に示すような赤色、緑色の印刷を行った以外は、実施例１と同様にしてカード状記録媒体を作製した。得られたカード状記録媒体について、実施例１と同様にして、消去、印字を繰り返したところ、印字が黒発色のために目視確認ができ、何回も繰り返しが可能であった。
【０１１７】
実施例３
実施例１において、図３のような黒印刷する代わりに、図１１に示すように、一部のみ黒印刷したこと以外は、実施例１と同様にしてカード状記録媒体を作製した。得られたカード状記録媒体について、実施例１と同じプリンターで図１１に示されるように黒発色させ、あみだくじを楽しむことができた。
【０１１８】
実施例４
実施例１において、図３のような黒印刷する代わりに、図１２のように秘密情報を黒印刷したこと以外は、実施例１と同様にしてカード状記録媒体を作製した。得られたカード状記録媒体について、実施例１と同じプリンターを用いて黒発色してシークレットにしておき、必要なときに、黒発色を消去して情報を確認することができた。本カードは偽造防止にも役立つ。
【０１１９】
実施例５
実施例１において、図２に示されるような断面の画像印刷層の代わりに図５に示されるようなグラデーションの青色印刷層を設けたこと以外は、実施例１と同様にしてカード状記録媒体を作製した。得られたカード状記録媒体について、実施例１と同様にして消去、印字を繰り返したが、印字が黒発色のため目視確認ができ、何回も繰り返しが可能であった。また、画像印刷層とその上の印刷層保護層との接着性がよいため、表面の印刷層保護層の劣化も小さいことがわかった。
【０１２０】
比較例１
リコー社製ＴＣフィルム（白濁型可逆性感熱記録媒体）ＦＢ６５１のカード形状としたものに、図５に示されるようなグラデーションの青印刷して、実施例１と同じプリンターで印字したところ、白濁色が見えないものであった。
【０１２１】
【発明の効果】
本発明の可逆性感熱記録媒体は、主体的に、支持体層、可逆性感熱記録層、画像印刷層からなり、可逆性感熱記録層と画像印刷層が面内において重なり合っている構成としたことから、同一面内に固定情報と可変情報を重ね、また印刷画像に画像の意味上関連させて、可逆性感熱記録媒体に発色画像を形成させることにより、可変する情報を視覚的に表示することが可能となる。
【図面の簡単な説明】
【図１】本発明の可逆性感熱記録媒体の発色・消色特性を示す図である。
【図２】本発明の可逆性感熱記録媒体の層構成を示す模式断面図である。
【図３】本発明の可逆性感熱記録媒体を用いて得られた記録画像の１例を示す図である。
【図４】本発明の可逆性感熱記録媒体を用いて得られた記録画像の別の１例を示す図である。
【図５】（ａ）は本発明の可逆性感熱記録媒体の１例の画像表示表面を示す平面図であり、（ｂ）は同媒体の模式断面図である。
【図６】（ａ）は本発明の可逆性感熱記録媒体の別の例の画像表示表面を示す平面図であり、（ｂ）は同媒体の模式断面図である。
【図７】（ａ）は本発明の可逆性感熱記録媒体の別の例の画像表示表面を示す平面図であり、（ｂ）は同媒体のさらに別の例の画像表示表面を示す平面図である。
【図８】本発明の可逆性感熱記録媒体の別の例の画像表示表面を示す平面図である。
【図９】本発明の可逆性感熱記録媒体の別の例の画像表示表面を示す平面図である。
【図１０】本発明の可逆性感熱記録媒体の別の例の画像表示表面を示す平面図である。
【図１１】（ａ）は本発明の可逆性感熱記録媒体の別の例の画像表示表面を示す平面図であり、（ｂ）は同媒体の可逆性画像を消去したときの画像表示表面を示す平面図である。
【図１２】（ｂ）は本発明の可逆性感熱記録媒体の別の例の画像表示表面を示す平面図であり、（ａ）は同媒体を発色させ印刷画像を隠すようにしたときの画像表示表面を示す平面図である。
【図１３】本発明の可逆性感熱記録媒体の別の例の画像表示表面を示す平面図である。
【図１４】本発明の可逆性感熱記録媒体の別の層構成を示す模式断面図である。
【図１５】本発明の可逆性感熱記録媒体の別の層構成を示す模式断面図である。
【図１６】本発明の可逆性感熱記録媒体の別の層構成を示す模式断面図である。
【図１７】本発明の可逆性感熱記録媒体の別の層構成を示す模式断面図である。
【符号の説明】
１ 可逆性感熱記録媒体
２ 支持体層
３ 可逆性感熱記録層
４ 記録層保護層
５ 画像印刷層
６ 画像印刷層保護層
７ 接着剤層
８ 第２の画像印刷層
９ 第２の支持体層
Ａ 印刷画像
ａ１、ａ２ 可逆性感熱記録層の発色画像[0001]
BACKGROUND OF THE INVENTION
The present invention uses a reversible thermosensitive coloring composition utilizing a coloring reaction between an electron-donating color-forming compound and an electron-accepting compound, and can control the formation of a color image and erase it by controlling thermal energy. The present invention relates to a reversible thermosensitive recording medium and a reversible thermosensitive recording method using the same.
[0002]
[Prior art]
A typical reversible thermosensitive recording medium that is put into practical use is a cloudy reversible thermosensitive recording medium (actually disclosed in Japanese Utility Model Laid-Open No. 1) which records an image by making it cloudy during heat recording and returns it to a transparent state by erasing. 165286) and a leuco dye using a leuco dye that develops black to blue color, etc., and erases and restores the background color of the original medium in the same manner as a normal irreversible thermosensitive recording medium during heating recording. There are two types of reversible thermosensitive recording materials (Japanese Patent Laid-Open Nos. 5-124360, 6-210954, 5-92661, and 4-303680).
[0003]
Thereafter, a recycling card in which the image printing layer and the reversible thermosensitive recording layer are laminated in a plane in a white turbid type has been proposed (Japanese Patent Laid-Open No. 8-150795). In addition, the paper-like property (black on a white background) is inferior and the visibility is also poor.
[0004]
On the other hand, a leuco type in which the image printing layer and the reversible thermosensitive recording layer are laminated in a plane is not yet found. As a similar one, there is a reversible thermosensitive recording medium (Japanese Patent Laid-Open No. 6-48026) in which one or more dye or pigment-containing layers are present, and this serves as a recording layer, an intermediate layer (recording layer) as a layer for absorbing ultraviolet rays. The intermediate layer between the protective layer and the protective layer is provided in any one of the protective layers, and the layer contains a dye or pigment for absorbing ultraviolet rays.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a leuco-type reversible thermosensitive recording medium in which an image printing layer and a reversible thermosensitive recording layer are provided so as to overlap each other, and an image of a printed image. In view of the above, it is an object of the present invention to provide a reversible thermosensitive recording medium capable of forming a color image on a reversible thermosensitive recording layer. It is another object of the present invention to provide a reversible thermosensitive recording medium in which the recording area is expanded over the entire surface of the medium without limiting the recording area as in the conventional product.
[0006]
[Means for Solving the Problems]
According to the present invention, first, on a support, an electron-donating color-forming compound and an electron-accepting compound are main components, and a relatively color is developed due to a difference in heating temperature and / or cooling rate after heating. A reversible thermosensitive recording medium having at least a reversible thermosensitive recording layer containing a reversible thermosensitive coloring composition capable of forming a state and a decolored state, wherein the medium is mainly a support layer When , Reversible thermosensitive recording layer When , Printed with printing ink containing curable resin as vehicle Image printing layer When When the reversible thermosensitive recording layer and the image print layer overlap in-plane and the reversible thermosensitive recording layer is heated to form a color image, the color image and the image print layer are printed. Provided is a reversible thermosensitive recording medium characterized in that at least a part of the image is combined, and the printed image of the image printing layer and the colored image of the reversible thermosensitive recording layer are semantically related. Is done.
[0007]
Second, on the support, the main component is an electron-donating color-forming compound and an electron-accepting compound, and a relatively colored state and a decolored state due to differences in heating temperature and / or cooling rate after heating. In a reversible thermosensitive recording medium having at least a reversible thermosensitive recording layer containing a reversible thermosensitive coloring composition capable of forming a substrate, the medium is mainly a support layer When , Reversible thermosensitive recording layer When , Printed with printing ink containing curable resin as vehicle Image printing layer When The reversible thermosensitive recording layer and the image printing layer are separated from each other in a plane, and when the reversible thermosensitive recording layer is heated to form a color image, the color development image and the image print layer A reversible thermosensitive recording medium characterized in that at least a part of a printed image is combined, and the printed image of the image printing layer and the colored image of the reversible thermosensitive recording layer are semantically related. Provided.
[0008]
Third, the reversible thermosensitive recording medium described in the first or second aspect is provided, wherein the reversible thermosensitive recording layer is provided on a part of the medium surface.
[0009]
Fourth, the reversible thermosensitive recording medium described in any one of the first to third is characterized in that the color of the image printing layer is the same as the color of the color image of the reversible thermosensitive recording layer. The
[0010]
Fifth, the reversible thermosensitive recording medium described in any one of the first to third is characterized in that the color of the image printing layer is different from the color of the color image of the reversible thermosensitive recording layer. The
[0011]
Sixth, the reversible thermosensitive recording medium described in any one of the first to fifth is provided, wherein the image printing layer is printed with halftone dots.
[0012]
Seventhly, the reversible thermosensitive recording medium described in any one of the first to sixth is provided, wherein the maximum level difference of the image print layer is 3 μm or less.
[0013]
Eighth, the reversible thermosensitive recording medium according to any one of the above first to seventh, wherein the reversible thermosensitive recording layer has a protective layer containing a curable resin or a heat-resistant resin on the surface thereof. Is done.
[0014]
Ninthly, the reversible thermosensitive recording medium according to any one of the first to eighth aspects, wherein a protective layer made of a curable resin or a heat resistant resin is provided on the surface of the image printing layer.
[0015]
Tenth, wherein the medium support layer is transparent and has a second support layer bonded to the back surface of the transparent support layer with an adhesive. A reversible thermosensitive recording medium according to any one of the above is provided.
[0016]
Eleventh, there is provided the reversible thermosensitive recording medium as described in the tenth above, wherein the reversible thermosensitive recording medium has a second printed layer on the sticking surface side of the second support layer.
[0017]
Twelfth, the reversible thermosensitive recording medium according to any one of the first to eleventh aspects is provided, wherein the medium has a card shape.
[0018]
Thirteenth, the reversible thermosensitive device according to any one of the first to twelfth aspects, wherein the medium carries any of an IC, a magneto-optical recording medium, an optical recording medium, and a magnetic recording medium. A recording medium is provided.
[0019]
Fourteenth, using the medium described in the first or the third to thirteenth, the reversible thermosensitive recording layer overlapping the image printing layer is colored, and the color image of the printed image and the reversible thermosensitive recording layer A reversible thermosensitive recording method is provided, wherein the two are overlapped in a plane.
[0020]
Fifteenth, using the medium according to any one of the above second to thirteen, The reversible thermosensitive recording layer is heated to form a color image, and the color image and at least a part of the print image of the image print layer are combined, and the print image and the color image are Related as meaning on image To be done A reversible thermosensitive recording method is provided.
[0021]
The reversible thermosensitive recording medium of the present invention mainly comprises a support layer, a reversible thermosensitive recording layer, and an image printing layer, and the reversible thermosensitive recording layer and the image printing layer are overlapped or overlapped in the plane. However, the reversible thermosensitive recording layer can be formed with a color image associated with the printed image of the image print layer and the meaning on the image.
[0022]
Note that the recycling card described in JP-A-8-150795 is a cloudy reversible thermosensitive recording medium, and the printed image and the color image of the reversible thermosensitive recording layer are not associated with each other. This is clearly different from the present invention. Further, the reversible thermosensitive recording medium described in JP-A-6-48026 is the same leuco type, but is a uniform layer with the dye / pigment-containing layer covering the entire surface (for the purpose of absorbing ultraviolet rays, This is different from the present invention in that it is fundamentally different from an image printing layer provided in an image-like manner and partially attached), and the printed image and the color image of the reversible thermosensitive recording layer are not associated in meaning.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
The reversible thermosensitive recording medium of the present invention mainly comprises a support layer, a reversible thermosensitive recording layer, and an image printing layer, and the reversible thermosensitive recording layer and the image printing layer are overlapped in the plane. Thereby, it is possible to display the fixed information and the variable information in the same plane.
When viewed from the surface, the reversible thermosensitive recording layer and the image print layer overlap, and the color of the image print layer alone, the color of the image print layer and the color of the image color of the reversible thermosensitive recording layer are synthesized. There is an effect that three kinds of colors, that is, the color of the color image of the reversible thermosensitive recording layer, can be expressed.
Further, when both of the following are related in terms of meaning, for example, as shown in FIG. 3, there is an effect that both images are connected continuously without a break (the arms are not separated).
[0024]
In the reversible thermosensitive recording medium of the present invention, the reversible thermosensitive recording layer develops an image that is semantically related to the print image of the image print layer. As a result, as illustrated in FIGS. 3 and 4 and others, the amount and degree of variable events can be visually displayed. That is, it is possible to make the variable amount of the fixed printed image variable by the color development of the reversible thermosensitive recording layer and easily visually recognize.
When the associated image is colored, the reversible thermosensitive recording layer and the image printing layer may be separated in the plane.
[0025]
Next, the configuration of the reversible thermosensitive recording medium of the present invention will be described with reference to the drawings. The basic configuration of the medium of the present invention is shown in FIG. That is, the medium of the present invention has a configuration in which a reversible thermosensitive recording layer 3, a recording layer protective layer 4, an image printing layer 5 and a printing layer protective layer 6 are provided in this order on a support layer 2. Of these, the recording layer protective layer and the print layer protective layer may be omitted. Further, as will be described later, other layers may be added as necessary in addition to the above five layers.
[0026]
The reversible thermosensitive recording layer may be present on a part of the medium surface or may be present on the entire surface. A structure in which the reversible thermosensitive recording layer is provided on a part of the medium is suitable for embossing the other part of the card. At the same time, the image printing layer may be partially present as shown in FIG. 2 or may be entirely present. Further, the layer order of the reversible thermosensitive recording medium of the present invention is not limited to the above, and is arbitrary, for example, in order from the bottom, a support layer, an image printing layer, a printing layer protective layer, a reversible thermosensitive recording layer, and a recording layer protective layer. You may be comprised in the order of a layer and the other order.
[0027]
The final form of the reversible thermosensitive recording medium of the present invention may take the form of a card, sheet, label or the like. The reversible thermosensitive recording medium of the present invention may be provided by laminating a reversible thermosensitive recording layer, an image printing layer, etc. on the support layer as described above, but the support layer is made of paper, film or sheet. Alternatively, an adhesive layer may be provided under the support layer and adhered to another support layer (second support layer). The medium of the present invention may carry a medium such as a magnetic recording medium, an optical recording medium, or a magneto-optical recording medium on the same body. Furthermore, an IC memory or the like may be carried. Thus, a composite function can be provided.
[0028]
The image printing layer includes a printed image of characters in addition to the image. Any printing method can be adopted.
[0029]
The color of the color image of the reversible thermosensitive recording layer may be the same or different from the color of the image print layer. If it is the same system, the image of the reversible thermosensitive recording layer connected to a part of the printed image can be moved and displayed (see FIG. 3). In FIG. 3, A represents a printed image, and a1 and a2 represent colored images of the reversible thermosensitive recording layer. FIG. 3 shows a state where the arm is raised. If they are different systems, the print image and the reversible thermosensitive recording layer image are simply recognized as separate bodies and then moved (see FIG. 4). In FIG. 4, A shows a printed image, and a1 shows a color image of the reversible thermosensitive recording layer. FIG. 4 shows a state in which, for example, a soap bubble is made. In these examples, the printed image and the image of the reversible thermosensitive recording layer are semantically related.
[0030]
The image print layer used here may be a print image using a transparent colored ink, but the color image of the reversible thermosensitive recording layer below is sufficiently exposed even on ordinary opaque ink. However, if the thickness of the ink layer is too thick, there is a limit because the lower color image does not appear due to light shielding.
If the image printing layer is formed by halftone printing, it is preferable because good translucency can be obtained. The density is controlled by gradation as shown in FIGS. 5A and 5B, or the density is controlled as two-color overlap, multi-color overlap or multi-stage overlap as shown in FIGS. 6A and 6B. be able to. At this time, the maximum step of each image print layer (in FIG. 6B), the lowermost surface of the image print layer closest to the support layer side and the uppermost surface of the image print layer farthest from the support layer. The difference is preferably 3 μm or less. If it is larger than this, the rubbing property of the thermal head is deteriorated, the image printing layer itself is thick, so that the light shielding property is increased, and it is necessary to increase the printing energy due to the heat loss in the image printing layer. It is not good because it promotes the deterioration of the layer. Again, the image print layer may be a multicolor reciprocal layer as well as a single color single layer.
[0031]
FIGS. 7A and 7B are examples of so-called point cards used in an amusement park or the like, in which two image printing layers are owned by red and green, respectively showing female and male users. For a male (female), the user ID number, the data of the day, etc. are raised below the male (female) image by the color image of the reversible thermosensitive recording layer. Furthermore, in this example, the score [16 (points)] for the day is recorded and displayed below. In this example, the printed image is overlapped with the color image of the reversible thermosensitive recording layer.
[0032]
The example of FIG. 8 is assumed to be used in, for example, a factory parts receiving department, and is assumed to be possessed by a supplier. For example, for the A part, the delivery time and number of the day are displayed in a color image of the reversible thermosensitive recording layer, and the delivery location of the part is indicated by six colors, and the part corresponds to any part of it. This is indicated by a color image of x. In this example, the printed image is overlapped with the color image of the reversible thermosensitive recording layer.
[0033]
FIG. 9 is an example of a card that represents the remaining amount of bottle keep at a bar, for example. In this example, the printed image and the color image of the reversible thermosensitive recording layer are associated with each other in terms of meaning.
Fig. 10 shows, for example, when a customer at a barber shop or beauty salon has a hairstyle recorded, he takes it next time and requests that hairstyle be used. This part is pre-printed with a printed image, and a hairstyle is recorded and superimposed on it. In this example, the printed image and the color image of the reversible thermosensitive recording layer are associated with each other in terms of meaning.
[0034]
11 (a) and 11 (b) are examples of Amidakuji, and only the vertical stripes are printed as shown in FIG. 11 (b), and the horizontal bar is recorded and displayed as a color image of the reversible thermosensitive recording layer. Different lots can be formed each time with one card. In this example, the printed image and the color image of the reversible thermosensitive recording layer are associated with each other in meaning, and the printed image overlaps the image of the reversible thermosensitive recording layer.
FIGS. 12A and 12B are examples of filling, and the printed image and the color image of the reversible thermosensitive recording layer have the same color, and the printed characters as shown in FIG. As shown in FIG. 12A, the background portion is colored to make the printed image invisible. In this example, the printed image is overlapped with the color image of the reversible thermosensitive recording layer.
[0035]
FIG. 13 shows an example of painting in the same manner as in FIG. 12. In this example, a human-shaped print image is painted by coloring the reversible thermosensitive recording layer according to the amount used, and the remaining amount is displayed. In this case, the image printing layer is laminated under the reversible thermosensitive recording layer. Conversely, the entire print image can be colored and painted over the entire reversible thermosensitive recording layer, and the color development portion can be gradually erased to bring out the print image. In this example, the printed image overlaps the image of the reversible thermosensitive recording layer.
[0036]
FIG. 14 shows another example in which the image printing layer and the reversible thermosensitive recording layer overlap each other in the medium of the present invention. The reversible thermosensitive recording layer 3 is partially present as viewed from the surface, and the image printing layer 5 is provided so as to overlap therewith.
[0037]
FIGS. 15A and 15B show the configuration of a medium used in an example in which a printed image and an image of a reversible thermosensitive recording layer are semantically related, and the image print layer and the reversible thermosensitive recording. In this example, the layers are separated from each other in the plane. (A) is a case where the image printing layer and the reversible thermosensitive recording layer are present in the same layer, and (b) is an example in which the image printing layer and the reversible thermosensitive recording layer are separated via a protective layer. is there.
In this example, as shown in FIG. 3, it is impossible to continuously form an image of A and a1 without any gaps, but it is possible to sufficiently associate the printed image and the image of the reversible thermosensitive recording layer.
[0038]
FIG. 16 shows another example of the support layer. The second support layer 9 is adhered to the back surface of the transparent support layer 2 via an adhesive (adhesive layer 7). A second image printing layer 8 may be provided on the adhesion-side surface of the second support layer 9.
As the second support layer 9, the same material as the support layer 2 is used, and an IC, a magneto-optical recording medium, an optical recording medium, a magnetic recording medium, etc. may be carried.
[0039]
FIG. 17 shows that a reversible thermosensitive recording medium is laminated on a support layer 2 in the order of an image printing layer 5, a printing layer protective layer 6, a reversible thermosensitive recording layer 3, and a recording layer protective layer 4. In this example, a reversible thermosensitive recording layer is partially attached.
[0040]
The apparatus for recording on the reversible thermosensitive recording medium of the present invention is recorded by an apparatus having a decoloring means, a printing means, and a cooling means after any one if necessary. An erasing bar is most preferable as the erasing means, and a thermal head is most preferable as the printing means. A thermal head can also be used as an erasing means.
[0041]
Next, the constituent materials of the reversible thermosensitive recording medium of the present invention will be described in detail.
In the present invention, the support or support layer is paper, resin film, synthetic paper, metal foil, glass, or a composite thereof, and the like, as long as it can hold the recording layer.
[0042]
The reversible thermosensitive coloring composition used in the reversible thermosensitive recording layer of the present invention comprises an electron donating color developing compound (namely, color former) and an electron accepting compound (namely, developer) as main components.
[0043]
As the developer used here, as disclosed in JP-A-5-124360 together with representative examples of phosphate compounds, fatty acid compounds and phenol compounds having a long-chain hydrocarbon group, the developer Color formation is stabilized by forming an aggregated structure between the color former and the color former, and the color of the color former and the developer are phase-separated and decolored by aggregation or crystallization of at least one of the two compounds. A compound having a structure capable of developing a color developing agent in the molecule and a structure controlling the cohesion between molecules is used.
[0044]
As a structure having a color developing ability, for example, an acidic group such as a phenolic hydroxyl group, a carboxyl group, and a phosphoric acid group is used, as in a general heat-sensitive recording medium. Just have to. These include, for example, thiourea groups, carboxylic acid metal salts, and the like.
[0045]
A typical structure for controlling the cohesive force between molecules is a hydrocarbon group such as a long-chain alkyl group. In general, the number of carbon atoms of the hydrocarbon group is preferably 8 or more in order to obtain good color forming / decoloring characteristics. Further, the hydrocarbon group may contain an unsaturated bond, and a branched hydrocarbon group is also included. Also in this case, the main chain portion preferably has 8 or more carbon atoms. The hydrocarbon group may be substituted with a group such as a halogen atom, a hydroxyl group, or an alkoxy group.
[0046]
As described above, the developer has a structure in which a structure having a color developing ability and a structure for controlling the cohesive force represented by a hydrocarbon group are connected. A divalent group containing a heteroatom as shown below or a group formed by combining a plurality of these groups may be bonded to this linking moiety. Further, an aromatic ring or a heterocyclic ring such as phenylene or naphthylene may be bonded, or both of them may be interposed. The hydrocarbon group may have a divalent group similar to the above in the chain structure, that is, a divalent group containing an aromatic ring or a hetero atom.
Hereinafter, the developer used in combination with the present invention will be specifically exemplified.
[0047]
Examples of the organic phosphate developer include the following compounds.
Dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, eicosylphosphonic acid, docosylphosphonic acid, tetracosylphosphonic acid, ditetradecyl phosphate, dihexadecyl phosphate, phosphoric acid Dioctadecyl ester, dieicosyl phosphate, dibehenyl phosphate, etc.
[0048]
Examples of the aliphatic carboxylic compound include the following compounds.
2-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 2-hydroxyoctadecanoic acid, 2-hydroxyeicosanoic acid, 2-hydroxydocosanoic acid, 2-bromohexadecanoic acid, 2-bromooctadecanoic acid, 2-bromoeicosanoic acid 2-bromodocosanoic acid, 3-bromooctadecanoic acid, 3-bromodocosanoic acid, 2,3-dibromooctadecanoic acid, 2-fluorododecanoic acid, 2-fluorotetradecanoic acid, 2-fluorohexadecanoic acid, 2-fluorooctadecanoic acid, 2 -Fluoroeicosanoic acid, 2-fluorodocosanoic acid, 2-iodohexadecanoic acid, 2-iodooctadecanoic acid, 3-iodohexadecanoic acid, 3-iodooctadecanoic acid, perfluorooctadecanoic acid and the like.
[0049]
Examples of the aliphatic dicarboxylic acid and tricarboxylic acid compounds include the following compounds.
2-dodecyloxy succinic acid, 2-tetradecyloxy succinic acid, 2-hexadecyloxy succinic acid, 2-octadecyloxy succinic acid, 2-eicosyloxy succinic acid, 2-dodecyloxy succinic acid, 2-dodecylthiosuccinic acid 2-tetradecylthiosuccinic acid, 2-hexadecylthiosuccinic acid, 2-octadecylthiosuccinic acid, 2-eicosylthiosuccinic acid, 2-docosylthiosuccinic acid, 2-tetracosylthiosuccinic acid, 2-hexadecyldithiosuccinic acid, 2-octadecyl dithiosuccinic acid, 2-eicosyl dithiosuccinic acid, dodecyl succinic acid, tetradecyl succinic acid, pentadecyl succinic acid, hexadecyl succinic acid, octadecyl succinic acid, eicosyl succinic acid, docosyl succinic acid, 2,3-dihexadecyl succinic acid, 2 , 3-Dioc Decyl succinic acid, 2-methyl-3-hexadecyl succinic acid, 2-methyl-3-octadecyl succinic acid, 2-octadecyl-3-hexadecyl succinic acid, hexadecyl malonic acid, octadecyl malonic acid, eicosyl malonic acid, docosyl malonic acid , Dihexadecylmalonic acid, dioctadecylmalonic acid, didocosylmalonic acid, methyloctadecylmalonic acid, 2-hexadecylglutaric acid, 2-octadecylglutaric acid, 2-eicosylglutaric acid, docosylglutaric acid, 2-pentadecyladipine Acid, 2-octadecyl adipic acid, 2-eicosyl adipic acid, 2-docosyl adipic acid, 2-hexadecanoyloxypropane-1,2,3-tricarboxylic acid, 2-octadecanoyloxypropane-1,2 , 3-tricarboxylic acid and the like.
[0050]
As the carboxylic acid compound, a compound represented by the following general formula (1) can also be used.
[Chemical 1]

[0051]
Specific examples of the carboxylic acid compound represented by the general formula (1) are shown in the following Tables 1 to 13 by the number or structure of p, q, r, s, A, B, X, and Y.
[0052]
[Table 1]

[0053]
[Table 2]

[0054]
[Table 3]

[0055]
[Table 4]

[0056]
[Table 5]

[0057]
[Table 6]

[0058]
[Table 7]

[0059]
[Table 8]

[0060]
[Table 9]

[0061]
[Table 10]

[0062]
[Table 11]

[0063]
[Table 12]

[0064]
[Table 13]

[0065]
Moreover, as a carboxylic acid compound used for a color developer, the compound represented by following General formula (2) can be illustrated.
[Chemical 2]

[0066]
Specific examples of the carboxylic acid compound represented by the general formula (2) are shown in the following Tables 14 to 18 by the number or structure of n, p, q, r, R, X, and Y.
[0067]
[Table 14]

[0068]
[Table 15]

[0069]
[Table 16]

[0070]
[Table 17]

[0071]
[Table 18]

[0072]
As the developer, a phenol compound having a structure for controlling intermolecular cohesive force is also preferably used. Examples thereof include a phenol compound represented by the following general formula (3).
[Chemical 3]

[0073]
Specific examples of the phenol compound represented by the general formula (3) are shown in the following Tables 19 to 25 by the number or structure of p, q, r, s, X, A, Y, and Z. However, in each of these specific examples, n of the phenol part is 1 to 3, for example, 4-hydroxyphenyl, 3-hydroxyphenyl, 2-hydroxyphenyl, 2,4-dihydroxyphenyl, 3,4-dihydroxyphenyl Alternatively, it is a phenyl group having at least one hydroxyl group such as 3,4,5-trihydroxyphenyl. This phenyl group may have a substituent other than a hydroxyl group. Moreover, as long as it has a phenolic hydroxyl group, another aromatic ring may be sufficient.
[0074]
[Table 19]

[0075]
[Table 20]

[0076]
[Table 21]

[0077]
[Table 22]

[0078]
[Table 23]

[0079]
[Table 24]

[0080]
[Table 25]

[0081]
The color former used in the present invention exhibits an electron donating property, and is itself a colorless or light-colored dye precursor (leuco dye), and is not particularly limited, and conventionally known ones such as phthalide compounds and azaphthalide compounds. , A fluoran compound, a phenothiazine compound, a leucooramine compound, and the like. The color former is shown below.
[0082]
Preferred color formers used in the present invention include compounds of the following general formula.
[Formula 4]

[Chemical formula 5]

(However, R ₁ Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₂ Represents a C1-C6 alkyl group, a cycloalkyl group or an optionally substituted phenyl group. Examples of the substituent for the phenyl group include an alkyl group such as a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, or a halogen atom. R _Three Represents a hydrogen atom, an alkyl group having 1 to 2 carbon atoms, an alkoxy group or a halogen atom. R _Four Represents a hydrogen atom, a methyl group, a halogen atom or an optionally substituted amino group. Examples of the substituent for the amino group include an alkyl group, an optionally substituted aryl group, and an optionally substituted aralkyl group. The substituent here is an alkyl group, a halogen atom, an alkoxy group or the like. )
[0083]
Specific examples of such a color former include the following compounds.
2-anilino-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-di (n-butylamino) fluorane, 2-anilino-3-methyl-6- (Nn-propyl-) N-methylamino) fluorane, 2-anilino-3-methyl-6- (N-isopropyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (N-isobutyl-N-methylamino) fluorane 2-anilino-3-methyl-6- (Nn-amyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (N-sec-butyl-N-methylamino) fluorane, 2 -Anilino-3-methyl-6- (Nn-amyl-N-ethylamino) fluorane, 2-anilino-3-methyl-6- (N-iso-amyl-N-ethylamino) Luolan, 2-anilino-3-methyl-6- (Nn-propyl-N-isopropylamino) fluorane, 2-anilino-3-methyl-6- (N-cyclohexyl-N-methylamino) fluorane, 2- Anilino-3-methyl-6- (N-ethyl-p-toluidino) fluorane, 2-anilino-3-methyl-6- (N-methyl-p-toluidino) fluorane, 2- (m-trichloromethylanilino) -3-methyl-6-diethylaminofluorane, 2- (m-trifluoromethylanilino) -3-methyl-6-diethylaminofluorane, 2- (m-trichloromethylanilino) -3-methyl-6 (N-cyclohexyl-N-methylamino) fluorane, 2- (2,4-dimethylanilino) -3-methyl-6-diethylaminofluorane 2- (N-ethyl-p-toluidino) -3-methyl-6- (N-ethylanilino) fluorane, 2- (N-ethyl-p-toluidino) -3-methyl-6- (N-propyl-p- Toluidino) fluoran, 2-anilino-6- (Nn-hexyl-N-ethylamino) fluorane, 2- (o-chloroanilino) -6-diethylaminofluorane, 2- (o-chloroanilino) -6-dibutylamino Fluorane, 2- (m-trifluoromethylanilino) -6-diethylaminofluorane, 2- (p-acetylanilino) -6- (Nn-amyl-Nn-butylamino) fluorane, 2 -Benzylamino-6- (N-ethyl-p-toluidino) fluorane, 2-benzylamino-6- (N-methyl-2,4-dimethylanilino) fluorane, 2- Benzylamino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-benzylamino-6- (N-methyl-p-toluidino) fluorane, 2-benzylamino-6- (N-ethyl- p-toluidino) fluorane, 2- (di-p-methylbenzylamino) -6- (N-ethyl-p-toluidino) fluorane, 2- (α-phenylethylamino) -6- (N-ethyl-p-) Toluidino) fluorane, 2-methylamino-6- (N-methylanilino) fluorane, 2-methylamino-6- (N-ethylanilino) fluorane, 2-methylamino-6- (N-propylanilino) fluorane, 2- Ethylamino-6- (N-methyl-p-toluidino) fluorane, 2-methylamino-6- (N-methyl-2,4-dimethylanilino) fur Oran, 2-ethylamino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-dimethylamino-6- (N-methylanilino) fluorane, 2-dimethylamino-6- (N-ethylanilino) Fluorane, 2-diethylamino-6- (N-methyl-p-toluidino) fluorane, 2-diethylamino-6- (N-ethyl-p-toluidino) fluorane, 2-dipropylamino-6- (N-methylanilino) fluorane 2-dipropylamino-6- (N-ethylanilino) fluorane, 2-amino-6- (N-methylanilino) fluorane, 2-amino-6- (N-ethylanilino) fluorane, 2-amino-6- (N -Propylanilino) fluorane, 2-amino-6- (N-methyl-p-toluidino) fluorane, 2-a Mino-6- (N-ethyl-p-toluidino) fluorane, 2-amino-6- (N-propyl-p-toluidino) fluorane, 2-amino-6- (N-methyl-p-ethylanilino) fluorane, 2 -Amino-6- (N-ethyl-p-ethylanilino) fluorane, 2-amino-6- (N-propyl-p-ethylanilino) fluorane, 2-amino-6- (N-methyl-2,4-dimethylani Lino) fluorane, 2-amino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-propyl-2,4-dimethylanilino) fluorane, 2-amino- 6- (N-methyl-p-chloroanilino) fluorane, 2-amino-6- (N-ethyl-p-chloroanilino) fluorane, 2-amino-6- (N-propyl-p- Loroanilino) fluorane, 2,3-dimethyl-6-dimethylaminofluorane, 3-methyl-6- (N-ethyl-p-toluidino) fluorane, 2-chloro-6-diethylaminofluorane, 2-bromo-6 -Diethylaminofluorane, 2-chloro-6-dipropylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 3-bromo-6-cyclohexylaminofluorane, 2-chloro-6- (N-ethyl- N-isoamylamino) fluorane, 2-chloro-3-methyl-6-diethylaminofluorane, 2-anilino-3-chloro-6-diethylaminofluorane, 2- (o-chloroanilino) -3-chloro-6-cyclohexyl Aminofluorane, 2- (m-trifluoromethylanilino) -3-chloro-6-die Ruaminofluorane, 2- (2,3-dichloroanilino) -3-chloro-6-diethylaminofluorane, 1,2-benzo-6-diethylaminofluorane, 1,2-benzo-6- (N- Ethyl-N-isoamylamino) fluorane, 1,2-benzo-6-dibutylaminofluorane, 1,2-benzo-6- (N-methyl-N-cyclohexylamino) fluorane, 1,2-benzo-6 (N-ethyl-N-toluidino) fluorane and others.
[0084]
Specific examples of other color formers preferably used in the present invention are as follows.
2-anilino-3-methyl-6- (N-2-ethoxypropyl-N-ethylamino) fluorane, 2- (p-chloroanilino) -6- (Nn-octylamino) fluorane, 2- (p- Chloroanilino) -6- (Nn-palmitylamino) fluorane, 2- (p-chloroanilino) -6- (di-n-octylamino) fluorane, 2-benzoylamino-6- (N-ethyl-p-) Toluidino) fluorane, 2- (o-methoxybenzoylamino) -6- (N-methyl-p-toluidino) fluorane, 2-dibenzylamino-4-methyl-6-diethylaminofluorane, 2-dibenzylamino-4 -Methoxy-6- (N-methyl-p-toluidino) fluorane, 2-dibenzylamino-4-methyl-6- (N-ethyl-p-toluidino) Luolan, 2- (α-phenylethylamino) -4-methyl-6-diethylaminofluorane, 2- (p-toluidino) -3- (t-butyl) -6- (N-methyl-p-toluidino) fluorane 2- (o-methoxycarbonylamino) -6-diethylaminofluorane, 2-acetylamino-6- (N-methyl-p-toluidino) fluorane, 3-diethylamino-6- (m-trifluoromethylanilino) Fluorane, 4-methoxy-6- (N-ethyl-p-toluidino) fluorane, 2-ethoxyethylamino-3-chloro-6-dibutylaminofluorane, 2-dibenzylamino-4-chloro-6- (N -Ethyl-p-toluidino) fluorane, 2- (α-phenylethylamino) -4-chloro-6-diethylaminofluorane, 2- N-benzyl-p-trifluoromethylanilino) -4-chloro-6-diethylaminofluorane, 2-anilino-3-methyl-6-pyrrolidinofluorane, 2-anilino-3-chloro-6-pyrrolidino Fluorane, 2-anilino-3-methyl-6- (N-ethyl-N-tetrahydrofurfurylamino) fluorane, 2-mesidino-4 ', 5'-benzo-6-diethylaminofluorane, 2- (m- Trifluoromethylanilino) -3-methyl-6-pyrrolidinofluorane, 2- (α-naphthylamino) -3,4 benzo-4′-bromo-6- (N-benzyl-N-cyclohexylamino) fluorane 2-piperidino-6-diethylaminofluorane, 2- (Nn-propyl-p-trifluoromethylanilino) -6-morpholinofluorane, 2- (Di-Np-chlorophenyl-methylamino) -6-pyrrolidinofluorane, 2- (Nn-propyl-m-trifluoromethylanilino) -6-morpholinofluorane, 1,2-benzo -6- (N-ethyl-Nn-octylamino) fluorane, 1,2-benzo-6-diallylaminofluorane, 1,2-benzo-6- (N-ethoxyethyl-N-ethylamino) fluorane Benzoleucomethylene blue, 2- [3,6-bis (diethylamino)]-6- (o-chloroanilino) xanthylbenzoate lactam, 2- [3,6-diethylamino)]-9- (o-chloroanilino) xanthylbenzoate Acid lactam, 3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethyla Nophthalide (also known as crystal violet lactone), 3,3-bis- (p-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis- (p-dimethylaminophenyl) -6-chlorophthalide, 3,3- Bis- (p-dibutylaminophenyl) phthalide, 3- (2-methoxy-4-dimethylaminophenyl) -3- (2-hydroxy-4,5-dichlorophenyl) phthalide, 3- (2-hydroxy-4-dimethyl) Aminophenyl) -3- (2-methoxy-5-chlorophenyl) phthalide, 3- (2-hydroxy-4-dimethoxyaminophenyl) -3- (2-methoxy-5-chlorophenyl) phthalide, 3- (2-hydroxy) -4-dimethylaminophenyl) -3- (2-methoxy-5-nitrophenyl) phthalide, 3- 2-hydroxy-4-diethylaminophenyl) -3- (2-methoxy-5-methylphenyl) phthalide, 3- (2-methoxy-4-dimethylaminophenyl) -3- (2-hydroxy-4-chloro-5) -Methoxyphenyl) phthalide, 3,6-bis (dimethylamino) fluorene spiro (9,3 ')-6'-dimethylaminophthalide, 3- (1-ethyl-2-methylindol-3-yl) -3 -(2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3- (1-octyl-2-methylindol-3-yl) -3- (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (2-ethoxy-4-diethylaminophenyl) -7-azaphthalide, 3, -Bis (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis (2-ethoxy-4-diethylaminophenyl) -7-azaphthalide, 6'-chloro-8'-methoxy-benzoindolino -Spiropyran, 6'-bromo-2'-methoxy-benzoindolino-spiropyran, etc.
[0085]
The reversible thermosensitive recording medium of the present invention can form a relatively colored state and a decolored state depending on the difference in heating temperature and / or cooling rate after heating. This basic coloring / decoloring phenomenon will be described. FIG. 1 shows the relationship between the color density of this recording medium and the temperature. When the temperature of the recording medium initially in the decolored state (A) is raised, the temperature T at which it begins to melt ₁ Color development occurs at a point, and a molten color state (B) is obtained. When rapidly cooled from the molten color state (B), the color state can be lowered to room temperature and a solid color state (C) is obtained. Whether or not this color development state is obtained depends on the rate of temperature decrease from the molten state. In slow cooling, the color disappears during the temperature decrease, and the same color disappearance state (A) or rapid color development state (C ) A relatively low concentration state is formed. On the other hand, when the temperature of the rapid color development state (C) is increased again, the temperature T lower than the color development temperature is reached. ₂ Then, decoloring occurs (from D to E), and when the temperature is lowered from here, it returns to the same decoloring state (A). The actual color development temperature and decoloration temperature vary depending on the combination of the developer and color former used, and can be selected according to the purpose. Further, the density of the melt coloring state and the coloring density when rapidly cooled are not necessarily the same and may be different.
[0086]
In the reversible thermosensitive recording medium of the present invention, the color development state (C) obtained by rapid cooling from the melt color development state (B) is a state in which the developer and the color former are mixed in a state where molecules can contact each other. Yes, this often forms a solid state. This state is a state where the developer and the color former are aggregated to maintain the color development, and it is considered that the color development is stabilized by the formation of this aggregated structure.
On the other hand, the decolored state is a state in which both phases are separated. This state is a state in which molecules of at least one compound aggregate to form a domain or crystallize, and the color former and developer are separated and stabilized by aggregation or crystallization. It is done. In many cases, in the present invention, more complete color erasure occurs due to phase separation of the two and crystallization of the developer. In both the decoloring by slow cooling from the molten state and the decoloring by raising the temperature from the colored state shown in FIG. 1, the aggregation structure changes at this temperature, and phase separation and crystallization of the developer occur. Conceivable.
[0087]
The color recording of the reversible thermosensitive recording medium of the present invention may be formed by heating to a temperature at which it is once melt-mixed by a thermal head or the like and then rapidly cooling. Further, decolorization is two methods, a method of slowly cooling from a heated state and a method of heating to a temperature slightly lower than the coloring temperature. However, they are the same in the sense that they are phase-separated or at least temporarily held at a temperature at which one crystallizes. The reason for rapid cooling in the formation of the colored state is to prevent the temperature from being maintained at this phase separation temperature or crystallization temperature. The rapid cooling and slow cooling here are relative to one composition, and the boundary thereof changes depending on the combination of the color former and the developer.
[0088]
The appropriate ratio of the color former and the developer in the reversible thermosensitive recording layer varies depending on the combination of the compounds used, but the developer is generally 0.1 to 20 with respect to the color developer 1 in a molar ratio. Range, preferably in the range of 0.2 to 10. If there is less or more developer than this range, the density of the colored state will decrease, which will be a problem.
[0089]
The recording layer may be any material as long as the color former and the developer are present, but generally, a state in which the color former and the developer are finely and uniformly dispersed in the binder resin is used. The color former and the developer may form particles individually, but more preferably form a dispersed state as composite particles. This can be achieved by once melting and dissolving the color former and developer. For forming such a recording layer, each material is dispersed and dissolved in a solvent and then mixed, or a solution in which each material is mixed and dispersed or dissolved in a solvent is applied onto a support and dried. Is done by. The color former and the developer can be used in a microcapsule.
[0090]
In the reversible thermosensitive recording medium of the present invention, an additive for improving or controlling the coating properties of the recording layer can be used as necessary. These additives include, for example, dispersants, surfactants, conductive agents, fillers, lubricants, antioxidants, light stabilizers, ultraviolet absorbers, color stabilizers, and other decoloring accelerators. .
[0091]
Examples of the binder resin used for forming the recording layer include polyvinyl chloride, polyvinyl acetate, vinyl chloride vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene copolymer, phenoxy resin, polyester, aromatic polyester, polyurethane, Examples include polycarbonate, polyacrylic acid ester, polymethacrylic acid ester, acrylic acid copolymer, maleic acid copolymer, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, and starches. The role of these binder resins is to keep the materials of the composition uniformly dispersed without being displaced by the application of heat for recording and erasing. Therefore, it is preferable to use a resin having high heat resistance as the binder resin. A curable resin may also be used.
[0092]
The curable resin is, for example, a combination of a crosslinking agent and a resin having an active group that reacts with the crosslinking agent, and is a resin that is crosslinked and cured by heat, electron beam, ultraviolet rays, or the like.
Resins used for thermosetting are, for example, phenoxy resin, polyvinyl butyral resin, cellulose acetate propionate, cellulose acetate butyrate, etc., resins having groups that react with crosslinking agents such as hydroxyl groups and carboxyl groups, or hydroxyl groups, carboxyl groups, etc. There are resins obtained by copolymerizing monomers with other monomers. Examples of the copolymer resin include a vinyl resin, an acrylic resin, a styrene resin, and the like. Specifically, a vinyl chloride-vinyl acetate-vinyl alcohol copolymer, a vinyl chloride-vinyl acetate-hydroxypropyl acrylate copolymer, Examples include vinyl chloride-vinyl acetate-maleic anhydride copolymer.
[0093]
Examples of the thermal crosslinking agent include isocyanates, amines, phenols, and epoxy compounds. For example, as isocyanates, there are polyisocyanate compounds having a plurality of isocyanate groups, specifically hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), xylylene diisocyanate (XDI), and trimethylolpropane thereof. And adduct type, burette type, isocyanurate type, and blocked isocyanates. As the addition amount of the crosslinking agent to the resin, the ratio of the functional group of the crosslinking agent to the number of active groups contained in the resin is preferably 0.01 to 2.0, and below this, the heat strength is insufficient. Adding more than this will adversely affect the color development and decoloring properties. Furthermore, you may use the catalyst used for this kind of reaction as a crosslinking accelerator. Examples of the crosslinking accelerator include tertiary amines such as 1,4-diazabicyclo [2,2,2] octane, and metal compounds such as organic tin compounds.
[0094]
Next, examples of the monomer used for electron beam and ultraviolet curing include the following.
Examples of monofunctional monomers
Methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, methacrylic acid Benzyl, methacrylic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, dimethylaminoethyl methacrylate methacrylate, diethylaminoethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, methacrylic acid Acid allyl, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, dimeta 1,3-butylene glycol silylate, 1,6-hexanediol dimethacrylate, trimethylolpropane trimethacrylate, 2-ethoxyethyl methacrylate, 2-ethylhexyl acrylate, 2-ethoxyethyl acrylate, 2-ethoxyethoxyethyl acrylate 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, dicyclopentenyl ethyl acrylate, N-vinyl pyrrolidone, vinyl acetate and the like.
[0095]
Examples of bifunctional monomers
1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, Bisphenol A ethylene oxide adduct diacrylate, glycerin methacrylate acrylate, diacrylate of propylene oxide 2-mole adduct of neopentyl glycol, diethylene glycol diacrylate, polyethylene glycol (400) diacrylate, diester of hydroxypivalic acid and neopentyl glycol ester Acrylate, 2,2-bis (4-acryloxydiethoxyphenyl) propane, neopen Diglycol of diglycol diglycate, diacrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate, 2- (2-hydroxy-1,1-dimethylethyl) -5-hydroxymethyl-5-ethyl-1, 3-dioxane diacrylate, tricyclodecane dimethylol diacrylate, ε-caprolactone adduct of tricyclodecane dimethylol diacrylate, diacrylate of glycidyl ether of 1,6-hexanediol, and the like.
[0096]
Examples of multifunctional monomers
Trimethylolpropane triacrylate, glycerin propylene oxide addition acrylate, trisacryloyloxyethyl phosphate, pentaerythritol acrylate, trimethylolpropane propylene oxide 3 mol adduct triacrylate, dipentaerythritol polyacrylate, dipentaerythritol caprolactone addition Polyacrylate, dipentaerythritol triacrylate of propionate, hydroxypivalaldehyde-modified dimethylolpropane triacrylate, tetraacrylate of dipentaerythritol propionate, ditrimethylolpropane tetraacrylate, pentaacrylate of dipentaerythritol propionate, dipenta Erythritol hexaacrylate ε- caprolactone adduct of dipentaerythritol hexaacrylate.
[0097]
Examples of oligomers
Bisphenol A-diepoxyacrylic acid adducts and the like.
[0098]
Moreover, when making it bridge | crosslink using an ultraviolet-ray, the following photoinitiators and photoinitiators are used.
Examples of photopolymerization initiators include benzoin ethers such as isobutyl benzoin ether, isopropyl benzoin ether, benzoin ethyl ether, and benzoin methyl ether; 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime Α-acyloxime esters such as 2, benzyl ketals such as 2,2-dimethoxy-2-phenylacetophenone, benzyl, hydroxycyclohexyl phenyl ketone; diethoxyacetone phenone, 2-hydroxy-2-methyl-1-phenylpropane-1 Acetophenone derivatives such as -one; ketones such as benzophenone, 1-chlorothioxanthone, 2-chlorothioxanthone, isopropylthioxanthone, 2-methylthioxanthone, 2-chlorobenzoxanthone It is. These photopolymerization initiators are used alone or in combination of two or more. The addition amount is preferably 0.005 to 1.0 part by weight, more preferably 0.01 to 0.5 part by weight, based on 1 part by weight of the monomer or oligomer.
[0099]
Examples of the photopolymerization accelerator include aromatic tertiary amines and aliphatic amines. Specific examples include p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, and the like. These photopolymerization accelerators are used alone or in combination of two or more. The addition amount is preferably 0.1 to 5 parts by weight, more preferably 0.3 to 3 parts by weight, relative to 1 part by weight of the photopolymerization initiator.
[0100]
Examples of the light source for ultraviolet irradiation include a mercury lamp, a metal halide lamp, a gallium lamp, a mercury xenon lamp, and a flash lamp, and the emission spectrum corresponding to the ultraviolet absorption wavelength of the photopolymerization initiator and the photopolymerization accelerator described above. What is necessary is just to use the light source which has. Further, as the ultraviolet irradiation condition, the lamp output and the conveyance speed may be determined according to the irradiation energy necessary for crosslinking the resin.
[0101]
Moreover, as an electron beam irradiation device, it is good to choose either scanning type or non-scanning type according to conditions such as irradiation area and irradiation dose, and according to the dose necessary to crosslink the resin as irradiation conditions, What is necessary is just to determine an electron flow, irradiation width, and a conveyance speed.
[0102]
The reversible thermosensitive recording medium of the present invention is basically provided with the above-described reversible thermosensitive recording layer on a support, and an image printing layer is further laminated thereon to form a reversible thermosensitive recording layer and an image printing layer. However, it is preferable to provide a protective layer on the reversible thermosensitive recording layer and / or image printing layer in order to improve the head matching property and the repeated durability during printing.
[0103]
The image printing layer in the present invention can be provided with printing ink containing pigments and dyes by offset, gravure, screen printing or the like. In addition, it is preferable to consider adhesiveness, heat resistance, and durability by using a thermosetting resin, a UV curable resin, and an EB curable resin for the vehicle of the printing ink.
[0104]
As the protective layer, polyvinyl alcohol, poly (meth) acrylic acid ester and other resins generally used in heat-sensitive recording media can be used. In particular, as a protective layer for a reversible heat-sensitive recording layer, a curable resin is used. Preferably, the protective layer for the image printing layer is made of a heat resistant resin.
[0105]
As described above, the curable resin is, for example, a combination of a crosslinking agent and a resin having an active group that reacts with the crosslinking agent, and is a resin that is crosslinked by heat, electron beam, ultraviolet rays, etc. The thermosetting resin, the ultraviolet curable resin, the electron curable resin, etc. are used similarly to the curable resin currently used.
[0106]
Examples of the heat resistant resin include polyimide and polyamideimide.
[0107]
The protective layer may contain additives such as an ultraviolet absorber, inorganic or / and organic filler, and lubricant. Examples of the resin used for the protective layer include polyvinyl alcohol, styrene maleic anhydride copolymer, carboxy-modified polyethylene, melamine-formaldehyde resin, and urea-formaldehyde resin in addition to the curable resin.
[0108]
Recording layer or image printing layer for the purpose of improving adhesion between recording layer or image printing layer and protective layer, preventing alteration of recording layer due to application of protective layer, and preventing migration of additives in protective layer to recording layer It is also preferable to provide an intermediate layer between the protective layer and the protective layer. Further, it is preferable to use a resin having low oxygen permeability for the protective layer and the intermediate layer provided on the recording layer. It becomes possible to prevent or reduce the oxidation of the color former and developer in the recording layer.
[0109]
In order to effectively use the applied heat, a heat insulating undercoat layer (heat insulating layer) can be provided between the support and the recording layer. The heat insulation layer can be formed by applying organic or inorganic fine hollow particles using a binder resin. An undercoat layer may be provided for the purpose of improving the adhesion between the support and the recording layer and preventing the recording layer material from penetrating into the support.
[0110]
For the intermediate layer and the undercoat layer, the same resin as that for the recording layer can be used. The protective layer, intermediate layer, recording layer, and undercoat layer contain inorganic fillers such as calcium carbonate, magnesium carbonate, titanium oxide, silicon oxide, aluminum hydroxide, kaolin, talc, and / or various organic fillers. Can do. In addition, a lubricant, a surfactant, a dispersant, and the like can be contained.
[0111]
In order to form a color image using the reversible thermosensitive recording medium of the present invention, the color image may be rapidly cooled after being heated above the color development temperature. Specifically, for example, when the recording layer is heated for a short time with a thermal head or laser light, the recording layer is locally heated, so that the heat is immediately diffused and abrupt cooling occurs, so that the colored state can be fixed. On the other hand, in order to erase the color, it may be heated and cooled for a relatively long time using an appropriate heat source, or may be temporarily heated to a temperature slightly lower than the coloring temperature. When heated for a long time, the temperature of a wide range of the recording medium rises, and the subsequent cooling becomes slow. As a heating method in this case, a hot roller, a hot stamp, hot air, or the like may be used, or heating may be performed for a long time using a thermal head. In order to heat the recording layer to the color erasing temperature range, for example, the applied energy may be lowered slightly from the time of recording by adjusting the voltage applied to the thermal head and the pulse width. If this method is used, recording / erasing can be performed only by the thermal head, and so-called overwriting becomes possible. Of course, it can be erased by heating to a decoloring temperature range with a heat roller or a heat stamp.
[0112]
【Example】
Hereinafter, the present invention will be described in more detail by way of examples. In the examples, “parts” and “%” are based on weight.
[0113]
Example 1
<Creation of recording layer>
1) 2-anilino-3-methyl-6-dibutylaminofluorane 2 parts
2) 8 parts developer with the following structure
[Chemical 6]

3) Phenoxy resin (PKHH manufactured by Union Carbide)
150 parts of a 15% tetrahydrofuran (THF) solution
The composition was pulverized and dispersed to a particle size of 1 to 4 μm using a ball mill. 20 parts of Coronate HL (adduct type hexamethylene diisocyanate 75% ethyl acetate solution) manufactured by Nippon Polyurethane Co., Ltd. was added to the resulting dispersion, and the mixture was stirred well to prepare a recording layer coating solution. The recording layer coating solution having the above composition was applied on a polyester film having a thickness of 100 μm using a wire bar, dried at 80 ° C., and then heated at 100 ° C. for 10 minutes and at 60 ° C. for 24 hours to obtain a film thickness of about 6.0 μm. The recording layer was provided.
[0114]
<Creation of protective layer>
1) 10 parts urethane acrylate UV curable resin
(C7-157 manufactured by Dainippon Ink, Inc.)
2) 90 parts of ethyl acetate
After the protective layer solution having the above composition is coated on the recording layer using a wire bar, the protective layer solution is cured by passing through a UV lamp with an irradiation energy of 80 W / cm at a conveyance speed of 9 m / min to protect the film with a thickness of 3 μm. A layer was provided to produce a reversible thermosensitive recording medium.
[0115]
As shown in the schematic cross section of FIG. 2 for the produced recording medium, an offset printing machine (manufactured by KOMORI) is used on the protective layer 4 with UV ink manufactured by Toyo Ink Co., as shown in FIG. The design was printed in black, and a surface protective layer was provided with OP ink manufactured by the company, and processed into a card shape. The obtained card-shaped recording medium, clear by Kyushu Matsushita Electric Co., Ltd. printer R3000 series, was repeated printing, even if the printed image a1, a2 freely, where is possible to distinguish whether a reversible part because of the black color I couldn't.
[0116]
Example 2
In Example 1, a card-like recording medium was produced in the same manner as in Example 1 except that red and green printing as shown in FIG. 7 was performed instead of printing the design as shown in FIG. 3 in black. The obtained card-like recording medium was repeatedly erased and printed in the same manner as in Example 1. As a result, the print was visually confirmed due to black color development, and could be repeated many times.
[0117]
Example 3
In Example 1, instead of black printing as shown in FIG. 3, a card-like recording medium was produced in the same manner as in Example 1 except that only part of the black printing was performed as shown in FIG. The obtained card-like recording medium was colored black as shown in FIG. 11 with the same printer as in Example 1 and enjoyed the Amidakuji.
[0118]
Example 4
In Example 1, instead of black printing as shown in FIG. 3, a card-like recording medium was produced in the same manner as in Example 1 except that confidential information was black printed as shown in FIG. The obtained card-like recording medium was black-colored and made secret by using the same printer as in Example 1, and when necessary, the black color was erased and the information could be confirmed. This card is also useful for preventing counterfeiting.
[0119]
Example 5
In Example 1, a card-like recording medium was prepared in the same manner as in Example 1 except that a gradation blue print layer as shown in FIG. 5 was provided instead of the cross-section image print layer as shown in FIG. Was made. The card-like recording medium obtained was erased and printed repeatedly in the same manner as in Example 1. However, since the printed color was black, it could be visually confirmed and repeated many times. Moreover, since the adhesiveness of an image printing layer and the printing layer protective layer on it was good, it turned out that the deterioration of the printing layer protective layer of a surface is also small.
[0120]
Comparative Example 1
When the TC film (white turbid reversible thermosensitive recording medium) FB651 made by Ricoh Co., Ltd. is used in the card shape of FB651, the gradation blue printing as shown in FIG. Was invisible.
[0121]
【The invention's effect】
The reversible thermosensitive recording medium of the present invention mainly comprises a support layer, a reversible thermosensitive recording layer, and an image printing layer, and the reversible thermosensitive recording layer and the image printing layer are configured to overlap in the plane. In addition, the variable information can be visually displayed by superimposing fixed information and variable information on the same plane and forming a color image on a reversible thermosensitive recording medium in relation to the printed image in terms of the meaning of the image. Is possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing color development / decolorization characteristics of a reversible thermosensitive recording medium of the present invention.
FIG. 2 is a schematic cross-sectional view showing a layer structure of a reversible thermosensitive recording medium of the present invention.
FIG. 3 is a diagram showing an example of a recorded image obtained using the reversible thermosensitive recording medium of the present invention.
FIG. 4 is a diagram showing another example of a recorded image obtained using the reversible thermosensitive recording medium of the present invention.
5A is a plan view showing an image display surface of one example of the reversible thermosensitive recording medium of the present invention, and FIG. 5B is a schematic sectional view of the medium.
6A is a plan view showing an image display surface of another example of the reversible thermosensitive recording medium of the present invention, and FIG. 6B is a schematic cross-sectional view of the medium.
7A is a plan view showing an image display surface of another example of the reversible thermosensitive recording medium of the present invention, and FIG. 7B is a plan view showing an image display surface of still another example of the same medium. It is.
FIG. 8 is a plan view showing an image display surface of another example of the reversible thermosensitive recording medium of the present invention.
FIG. 9 is a plan view showing an image display surface of another example of the reversible thermosensitive recording medium of the present invention.
FIG. 10 is a plan view showing an image display surface of another example of the reversible thermosensitive recording medium of the present invention.
11A is a plan view showing an image display surface of another example of the reversible thermosensitive recording medium of the present invention, and FIG. 11B shows the image display surface when the reversible image of the medium is erased. FIG.
12 (b) is a plan view showing an image display surface of another example of the reversible thermosensitive recording medium of the present invention, and FIG. 12 (a) is an image when the medium is colored and the printed image is hidden. It is a top view which shows a display surface.
FIG. 13 is a plan view showing an image display surface of another example of the reversible thermosensitive recording medium of the present invention.
FIG. 14 is a schematic cross-sectional view showing another layer structure of the reversible thermosensitive recording medium of the present invention.
FIG. 15 is a schematic cross-sectional view showing another layer structure of the reversible thermosensitive recording medium of the present invention.
FIG. 16 is a schematic cross-sectional view showing another layer structure of the reversible thermosensitive recording medium of the present invention.
FIG. 17 is a schematic cross-sectional view showing another layer structure of the reversible thermosensitive recording medium of the present invention.
[Explanation of symbols]
1 Reversible thermosensitive recording medium
2 Support layer
3 Reversible thermosensitive recording layer
4 Recording layer protective layer
5 Image printing layer
6 Image printing layer protective layer
7 Adhesive layer
8 Second image printing layer
9 Second support layer
A Print image
a1, a2 Colored image of reversible thermosensitive recording layer

Claims (13)

On the support, an electron-donating color-forming compound and an electron-accepting compound are the main components, and a relatively colored state and a decolored state can be formed due to differences in heating temperature and / or cooling rate after heating. A reversible thermosensitive recording medium having at least a reversible thermosensitive recording layer containing a reversible thermosensitive coloring composition, wherein the medium mainly comprises a support layer, a reversible thermosensitive recording layer, and a curable resin as a vehicle. It consists of a black printed image printed layer with ink, which overlaps the reversible thermosensitive recording layer and the image printing layer is in the plane, and a color image reversible thermosensitive recording layer is being heated black color When formed, the color image and at least a part of the print image of the image print layer are combined, and the print image of the image print layer and the color image of the reversible thermosensitive recording layer are semantically related. The Reversible thermosensitive recording medium characterized Rukoto. On the support, an electron-donating color-forming compound and an electron-accepting compound are the main components, and a relatively colored state and a decolored state can be formed due to differences in heating temperature and / or cooling rate after heating. A reversible thermosensitive recording medium having at least a reversible thermosensitive recording layer containing a reversible thermosensitive coloring composition, wherein the medium mainly comprises a support layer, a reversible thermosensitive recording layer, and a curable resin as a vehicle. A color image formed of an image printed layer black- printed with ink, wherein the reversible thermosensitive recording layer and the image print layer are separated from each other in a plane, and the reversible thermosensitive recording layer is heated to produce black color When the image is formed, the color image and at least part of the print image of the image print layer are combined, and the print image of the image print layer and the color image of the reversible thermosensitive recording layer are semantically related. Has been Reversible thermosensitive recording medium, wherein the door.   3. The reversible thermosensitive recording medium according to claim 1, wherein the reversible thermosensitive recording layer is provided on a part of the medium surface. The reversible thermosensitive recording medium according to any one of claims 1 to 3, wherein the image printing layer is printed with halftone dots. The reversible thermosensitive recording medium according to claim 1, wherein a maximum step of the image print layer is 3 μm or less. 6. The reversible thermosensitive recording medium according to claim 1, further comprising a protective layer containing a curable resin or a heat resistant resin on the surface of the reversible thermosensitive recording layer. The reversible thermosensitive recording medium according to claim 1, further comprising a protective layer made of a curable resin or a heat resistant resin on the surface of the image print layer. The support layer of the medium is transparent, and has a second support layer adhered to the back surface of the transparent support layer via an adhesive. The reversible thermosensitive recording medium described. The reversible thermosensitive recording medium according to claim 8, further comprising a second printed layer on the sticking surface side of the second support layer. The reversible thermosensitive recording medium according to claim 1, wherein the medium has a card shape. The reversible thermosensitive recording medium according to claim 1, wherein the medium carries an IC, a magneto-optical recording medium, an optical recording medium, or a magnetic recording medium. Using the medium according to claim 1 or 3 to 11, the reversible thermosensitive recording layer overlapping the image printing layer is colored, and the printed image and the color developing image of the reversible thermosensitive recording layer are overlapped in the plane. A reversible thermosensitive recording method. Using the medium according to any one of claims 2 to 11, the reversible thermosensitive recording layer is heated to form a color image, and the color image and at least a part of the print image of the image print layer are combined to form an image. A reversible thermosensitive recording method characterized in that the printed image and the colored image are related as meanings on the image.

Images