JP3760204B2 - Dielectric recording element and image forming method using the same - Google Patents

Description

【００２９】
【化２】

【００３０】
末端に液晶性基（メソゲン基）を有し、ホトクロミズムを示す官能基を側鎖に有する側鎖型高分子液晶（Ｃ）は、上述した強誘電性を示す側鎖型の高分子液晶（Ａ）の製造方法において、強誘電性を示す官能基を有する液晶性基（メソゲン基）に代えて、末端に液晶性基（メソゲン基）を有し、ホトクロミズムを示す官能基を有する材料を用いることによって容易に製造することができる。
【００３１】
末端に液晶性基（メソゲン基）を有するホトクロミズムを示す官能基としては、例えば、以下のものが挙げられる。
【００３２】
【化３】

【００３３】
【化４】

【００３４】
【化５】

【００３５】
ホトクロミズムを示す化合物と強誘電性を示す化合物を含有する組成物から成る有機誘電体層（１）の場合、組成物中のホトクロミズムを示す化合物の割合は、０．１〜５０モル％の範囲が好ましい。ホトクロミズムを示す化合物の割合が５０モル％よりも多い場合、光書き込み時の応答速度は速くなるが、強誘電層の自発分極が小さくなり、その結果、十分なコントラストを持つ画像が得られなくなる傾向にあるので、好ましくない。また、ホトクロミズムを示す化合物の割合が０．１モル％よりも少ない場合、強誘電層の自発分極は大きくなるが、光書き込み時の応答速度が遅くなり、その結果、双極子の配向変化が十分起こらなく、十分なコントラストを持つ画像が得られなくなる傾向にあるので、好ましくない。
【００３６】
強誘電性を示す液晶性基（メソゲン基）を有する共重合可能なビニルモノマー（Ｄ）は、強誘電性を示す液晶性基（メソゲン基）を有するアクリルモノマー又はビニルモノマーが挙げられる。強誘電性を示す液晶性基（メソゲン基）は、強誘電性を示す側鎖型の高分子液晶（Ａ）の製造方法において説明したものが使用できる。
【００３７】
ホトクロミズムを示す官能基を有する共重合可能なモノマー（Ｅ）は、ホトクロミズムを示す官能基を有するアクリルモノマー又はビニルモノマーが挙げられる。ホトクロミズムを示す官能基は、ホトクロミズムを示す官能基を有する高分子化合物（Ｂ）の製造方法において説明したものが使用できる。
【００３８】
末端に液晶性基（メソゲン基）を有し、ホトクロミズムを示す官能基を有する共重合可能なビニルモノマー（Ｆ）は、末端に液晶性基（メソゲン基）を有し、ホトクロミズムを示す官能基を有するアクリルモノマー又はビニルモノマーが挙げられる。末端に液晶性基（メソゲン基）を有するホトクロミズムを示す官能基は、末端に液晶性基（メソゲン基）を有し、ホトクロミズムを示す官能基を側鎖に有する側鎖型高分子液晶（Ｃ）の製造方法において説明したものが使用できる。
【００３９】
強誘電性を示す液晶性基（メソゲン基）とホトクロミズムを示す官能基とが結合した置換基を側鎖に有する側鎖型の高分子液晶（３）は、強誘電性を示す側鎖型の高分子液晶（Ａ）において、強誘電性を示す液晶性基（メソゲン基）と高分子の主鎖との間にホトクロミズムを示す官能基を導入した材料である。この側鎖型高分子液晶（３）は、上述した強誘電性を示す側鎖型の高分子液晶（Ａ）の製造方法において、強誘電性を示す官能基を有する液晶性基（メソゲン基）に代えて、強誘電性を示す液晶性基（メソゲン基）が結合したホトクロミズムを示す官能基を有する材料を用いることによって容易に製造することができる。
【００４０】
強誘電性を示す液晶性基（メソゲン基）が結合したホトクロミズムを示す官能基としては、例えば、以下のものが挙げられる。
【００４１】
【化６】

【００４２】
ホトクロミズムを示す官能基を一構成要素とする強誘電性を示す液晶性基（メソゲン基）を側鎖に有する側鎖型の高分子液晶（４）は、強誘電性を示す側鎖型の高分子液晶（Ａ）において、強誘電性を示す液晶性基（メソゲン基）中にホトクロミズムを示す官能基を導入した材料である。この側鎖型の高分子液晶（４）は、上述した強誘電性を示す側鎖型の高分子液晶（Ａ）の製造方法において、強誘電性を示す官能基を有する液晶性基（メソゲン基）に代えて、ホトクロミズムを示す官能基を導入した強誘電性を示す液晶性基（メソゲン基）を有する材料を用いることによって容易に製造することができる。
【００４３】
ホトクロミズムを示す官能基を導入した強誘電性を示す液晶性基（メソゲン基）としては、例えば、以下のものが挙げられる。
【００４４】
【化７】

【００４５】
強誘電性を示す置換基とホトクロミズムを示す官能基を側鎖に有する側鎖型高分子液晶から成る有機誘電体層（２）を用いる場合、ホトクロミズムを示す官能基の割合は、０．２〜５０モル％の範囲が好ましく、０．５〜２０モル％の範囲が特に好ましい。ホトクロミズムを示す官能基の割合が５０モル％よりも多い場合、光書き込み時の応答速度は速くなるが、強誘電層の自発分極が小さくなり、その結果、十分なコントラストを持つ画像が得られなくなる傾向にあるので、好ましくない。ホトクロミズムを示す官能基の割合が０．２モル％よりも少ない場合、強誘電層の自発分極は大きくなるが、光書き込み時の応答速度が遅くなり、その結果、双極子の配向変化が十分起こらなく、十分なコントラストを持つ画像が得られなくなる傾向にあるので、好ましくない。
【００４６】
ホトクロミズムを示す官能基を液晶性基（メソゲン基）の末端置換基、スペーサーの一部、又は中央結合基として導入し、ホトクロミズムを示す官能基が光幾何異性化反応を起こすことにより、液晶性基（メソゲン基）の立体構造が棒状を示すことにより液晶性を与えることができる。更に環構造の置換基の有無、スペーサーの長さや末端置換基の炭素数を調整して所望の液晶相の種類、相系列、温度範囲を得ることができる。
【００４７】
本発明の誘電体記録素子の有機誘電体層を構成する化合物が液晶相を示す場合、液晶相はポーリング（双極子配向）処理時、光書き込み時において、スメクチック層の垂線方向からメソゲン基の長軸方向が傾いているキラルスメクチックＣ（ＳｍＣ^* ）を示すものが好ましいが、キラルスメクチックＩ、キラルスメクチックＦ、キラルスメクチックＪ、キラルスメクチックＫ、キラルスメクチックＨ等であっても良い。ポーリング（双極子配向）処理及び光書き込み時の液晶相の温度範囲は、種々の範囲を採ることが可能であるが、操作性、利便性等からその温度範囲は広いことが望ましく、具体的には、０〜８０℃の範囲が特に好ましい。
【００４８】
有機誘電体層を構成する化合物に必要な相系列は、強誘電性を示す液晶相が液晶相系列の中に含まれていれば良い。配向処理した基板を用いてメソゲン基を基板に対して平行に配向させる必要がある場合、高温側より、等方相、ネマッチック相又はコレステリック相、スメクッチックＡ相、キラルスメクッチック相、の順に続くのが好ましく、良好な配向が得られる。この相系列の下には、キラルスメクッチックＩ、キラルスメクッチックＦの順、又はキラルスメクッチックＩのみ、キラルスメクッチックＦのみの順で続いてもよい。更に、これらの低温側に他の液晶相が出現しても良く、ガラス状態に転移しても良い。低温側の液晶相としては、例えば、キラルスメクッチックＪ、キラルスメクッチックＫ、キラルスメクッチックＨ、キラルスメクッチックＧ等が挙げられる。
【００４９】
本発明の側鎖型の高分子液晶における液晶性基（メソゲン基）を基板の方向にホモジニアス配向させるには、配向処理を施した基板上の有機誘電体層を等方相まで一度加熱して徐冷すれば良く、特に等方相、ネマッチック相、スメクッチックＡ相の順に相転移する材料から成る有機誘電体層に対して配向処理は有効である。徐冷速度は遅いほどメソゲン基の配向性を高めることができるが、５℃／分以下の速度が好ましい。
【００５０】
本発明の誘電体記録素子において、必要に応じて、導電性基板と有機誘電体層との間に薄膜の絶縁層を積層しても良く、更に誘電体層表面に絶縁性の保護膜を設けることもできる。
【００５１】
本発明の誘電体記録素子を構成する有機誘電体層は光応答性及び強誘電性という二つの機能を有するので、本発明の誘電体記録素子は、光り書き込み可能で、しかもメモリー性を有する効果を奏するのである。有機誘電体層に光応答性を付与したホトクロミック有機化合物を用いることにより、光を用いて有機誘電体層に高速で画像を書き込むことが可能となる。
【００５２】
通常、強誘電性化合物は、印加電場の方向によって自発分極の向きが決るが、印加電圧（Ｅ）に対して電気量（Ｄ）の変化をプロットするとヒステリシス曲線を描くものであり、このヒステリシス曲線の例を図１に掲示した。このようなヒステリシス曲線は、強誘電性化合物に特有のものであり、本発明の有機誘電体層を有する誘電体記録素子においても同様である。
【００５３】
次に、本発明の画像記録方法Ａについて説明する。
【００５４】
本発明の画像記録方法Ａは、本発明の誘電体記録素子に対し、電場を印加することにより該有機誘電体層の双極子を同一方向に揃えた後、抗電場以下の逆電場を印加しながら光を照射することにより、（１）光照射部分のホトクロミズムで誘起される双極子の配向方向の反転に伴う有機誘電体層内における双極子の配向方向の相違によって生じる表面電荷密度の差、又は（２）光照射部分のホトクロミズムで誘起される双極子の配向方向の反転によって生じた表面電荷密度に差を有する有機誘電体層に、更に帯電処理を施すことによって生じる受容電位の差、を利用して静電トナーを付着させて可視画像を形成する方法である。
【００５５】
図１に示したように、光を照射しない場合（図１における太線のヒステリシス曲線に相当）、メソゲン基の自発分極の向きを同一方向に揃えた状態（ポーリング（双極子配向）処理）では、逆向きの電場をある一定の値（抗電場）まで印加しても自発分極の反転に基づく配向変化は起きない。
【００５６】
しかしながら、同じ大きさの電場を印加しながら光を照射した場合（図１における細線のヒステリシス曲線に相当）、ホトクロック化合物の分子構造が可逆的に変化し、その構造変化は、それを取り囲むメソゲン基の配列状態をも変化させるので、光照射によって強誘電性化合物のヒステリシス曲線を実際に変えることができる。
【００５７】
即ち、電圧を印加しながら光を照射することによって、抗電場の値を変化させると同時に、光を照射しない場合の抗電場より小さい逆向きの電場を印加しながら光を照射することによって、有機誘電体層中の双極子の自発分極の向きが容易に反転し、それに伴い光照射部と未照射部の表面電荷密度が変化する現象を利用したものが本発明の画像形成方法Ａである。
【００５８】
このように、光を用いて有機誘電体層に情報を書き込むことによって、有機誘電体層に情報を潜像として記録することができる。記録された潜像を可視画像とするには、一般の電子写真法で使用されている方法と同様に、画像露光後、コロナ帯電、静電トナー現像を行うか、又は、画像露光後、直接静電トナー現像すればよく、また、普通紙、フィルム等に画像を形成させる場合には、一般の電子写真法と同様の方法によって、静電トナー現像画像を転写、定着すればよい。
【００５９】
有機誘電体層に記録した画像は、強誘電性を有する有機誘電体の特徴である自発分極のメモリー性を利用して、書き込み画像を潜像として長期間保存することが可能で、任意時期に、静電トナー現像して画像を普通紙等へ転写することができる。また、潜像の追加書き込み、消去を随時行うこともできる。
【００６０】
複数枚の同一画像を連続して作成するには、一回の光書き込み工程により強誘電性の自発分極の作用で画像を記憶できることから、画像露光後は、静電トナー現像、転写、定着を連続して行えば良い。転写条件や周囲の環境の影響でコントラスト等が低下するなどの場合は、必要に応じて、コロナ帯電、ローラ帯電を行った後、トナー現像、転写、定着を行ない、連続して可視画像を作成させることもできる。また、連続複写中に、有機誘電体層表面に静電トナーが物理吸着、未転写等で汚れとして付着する場合には、ブレード等を使用して表面をクリーニングすることが好ましく、これを１回の前記工程毎に行ってもよく、数回の前記工程毎に実施しても良い。
【００６１】
ポーリング（双極子配向）処理は、有機誘電体層の自発分極が最大となるように処理する方法であって、具体的には、コロナ帯電による方法、又は、ローラ電極による方法が挙げられる。コロナ帯電によるポーリング（双極子配向）処理は、通常のコロトロン方式、スコロトロン方式によるコロナ帯電器を用いて行うことができる。また、ローラ帯電によるポーリング（双極子配向）処理は、高電圧が印加された導電性ゴムローラを有機誘電体層に接触させ、例えば、抵抗値１０⁵〜１０⁹Ωcm程度の導電性ゴムローラに数百ボルト以上の電圧を印加して帯電させる方法、抵抗値１０³〜１０⁵Ωcmの細い繊維状の線材を導電性ローラ表面にブラシ状に取り付けて接触性を高め、導電性ローラに高電圧を印加して帯電させる方法が挙げられる。両方法とも、装置のシステム構成等に応じて好適な方法を選択すればよい。ポーリング（双極子配向）に要する時間は、コロナ電圧、ローラ電極の印加電圧又はその形状に依存し、装置のシステム構成、装置の使用方法又は用途に応じて適宜設定することができる。
【００６２】
画像の書き込みは、ポーリング（双極子配向）処理された有機誘電体層に抗電場以下の逆電場を前記帯電方法と同様に印加しながら、有機誘電体層中のホトクロミック化合物にホトクロミズム反応を引き起こし得る波長の光を用いて行う。
【００６３】
画像の書き込みに用いる光源としては、水銀灯、キセノン灯等の他に、ホトクロミック反応を引き起こし得る波長の光を発信するレーザー、例えば、ヘリウム−カドミウムレーザー、アルゴンレーザー、ヘリウム−ネオンレーザー、半導体レーザー等を適宜使用することができる。
【００６４】
画像は、ポーリング（双極子配向）処理された有機誘電体層表面に、レンズ等光学系を用いて結像させた投影画像を書き込むことができる。また、画像を記録した写真フィルム等を有機誘電体層表面に配置させて露光する方法によっても、画像を書き込むことができる。これらの書き込み露光時間は、有機誘電体層の感度及び温度に応じて最適値を設定することが好ましい。
【００６５】
テレビやコンピュータ等の画像データを書き込む場合は、電気信号を外部光変調器又は発光素子を用いて変換して光照射強度の変化とし、ポリゴンスキャナー等で誘電体層表面を直線状に光を走査させ、誘電体層の移動により二次元画像を潜像として書き込むこともできる。更に、マイクロシャターアレイや発光素子を直線状に配列させたアレイを用いてテレビやコンピュータ等の画像データを変換して光照射強度の変化とし、誘電体層の移動により二次元画像を書き込むこともできる。
【００６６】
誘電体層を移動させて露光させる場合は、書き込み光の強度、有機誘電体層の感度及び温度に応じて誘電体層の移動速度を最適化することが望ましい。また、誘電体層の移動速度を一定とした場合は、書き込み光の強度を調整して最適露光させることもできる。書き込み時の有機誘電体層の温度は、有機誘電体層のキューリー点以下であればよく、強誘電性を示す温度範囲内で、かつ、有機誘電体層の自発分極が大きくなる温度領域に設定した場合、静電トナー現像処理の適温領域と一致するため、より好ましい。
【００６７】
画像書き込み後は、強誘電性を示す温度で静電粉体トナー又は液体トナーを用いて有機誘電体層の現像を行なうことによって、未露光部分にトナーが付着させて書き込み画像を可視化することができる。
【００６８】
有機誘電体層表面に現像されたトナー像は、普通紙やフィルムを重ねた後、普通紙やフィルム裏面を帯電させることにより、静電的に普通紙やフィルムにトナー像を転写させることができる。
【００６９】
潜像として書き込まれた画像を有する有機誘電体は、長期間保存することが可能である。その保存条件は、一定温度以下で保存することが望ましく、保存温度範囲としては、有機誘電体層の融点以下で、強誘電性を示す温度の上限Ｔｃ（キューリー点）以下が好ましい。また、短期間であれば、明室でも保存可能であるが、長期間の保存には、暗室の使用が望ましい。
【００７０】
本発明の画像形成方法Ａを図２を用いて更に詳細に説明する。
図２の（１）は、本発明の画像記録方法Ａの第１段階であって、導電層（４）を有する基板（５）上に有機誘電体層（３）を設けて成る本発明の誘電体記録素子に、コロナ帯電器（１）を用いて抗電場以上の電場を印加して有機誘電体層中の強誘電性を示す液晶性基（メソゲン基）の双極子（２）の自発分極の向きを電場方向に整列させた状態を模式的に示したものである。図２の（１）状態とした後、図２の（２）に示したように、抗電場以下の逆向きの電場を印加した状態で、ホトクロミズムを引き起こす波長の光を照射すると、図２の（３）に示したように、ホトクロミズムを示す官能基の構造が変化し、その変化に伴ってホトクロミズムを示す官能基を取り囲む液晶性基（メソゲン基）の配列状態も変化し、印加電場の作用により強誘電性を示す液晶性基（メソゲン基）の自発分極の向きが反転することにより、潜像が形成される。
【００７１】
即ち、本発明の画像形成方法Ａでは、強誘電性を利用して、ポーリング（双極子配向）処理により、自発分極を電界方向に整列させた後、抗電場以下の逆電場を印加しながら光書き込みを行い、光異性化に伴う強誘電性を示す化合物の配向に乱れが生じる結果、光照射部は光未照射部とは異なるヒステリシス曲線を示すため、双極子の配向方向が反転し、潜像が形成される。誘電体層に形成された自発分極が電界方向に整列した未光照射部と、逆方向に整列した光照射部では、表面電荷密度に相違があるため、静電トナーの吸引力に差が生じ、或いは表面電荷密度に相違がある状態でコロナ帯電、ローラー帯電等を行った場合、受容電位に差が生じ、静電トナーを用いて現像を行うことにより、図２の（４）に示したように可視化される。
【００７２】
誘電体層上に付着した静電トナーは、図２の（５）に示したように、通常の電子写真法と同様に、紙、又はフィルム等へ転写され、定着されて図２の（７）に示したように、印刷物が得られる。一方、図２の（６）に示したように、静電トナー転写後の誘電体層は、画像記録された双極子の方向は、潜像としてメモリー（記憶）されているため、必要に応じて表面をクリーニングし、次の印刷、即ち、図２における（４）−（５）−（６）−（７）の工程を繰り返すことにより、連続して所望枚数の同一画像を得ることができる。
【００７３】
本発明の画像形成方法Ａによれば、光異性化の速度で画像の書き込みが可能となり、高速化が計られ、また、分子レベルでの高密度書き込み、高解像力化が計られる。更に、一度書き込まれた潜像は、電界を取り除いても維持され、光、環境安定性を持ち、長期間の保存が可能であり、随時、情報の追加書き込み、修正、消去が可能である。
【００７４】
また、本発明の画像形成方法Ａにおいては、通常の電子写真法による現像を行うことができ、カラー画像の形成も可能である。
【００７５】
本発明の画像形成方法Ａにおいて、潜像として保存した情報を消去するには、記録時と逆向きの抗電場以上の電場を印加しながらホトクロミック反応が元に戻る反応の光を照射する方法、或はホトクロミック反応を元に戻す波長の光を照射してから逆向きの抗電場以上の電場を印加する方法が挙げられる。
【００７６】
次に、本発明の画像形成方法Ｂについて説明する。
【００７７】
本発明の画像形成方法Ｂは、本発明の誘電体記録素子に対し、電場を印加することにより該有機誘電体層の双極子を同一方向に揃えた後、該誘電体層の強誘電性を示す温度において光書き込みを行うことにより生じる光による書き込み部分のホトクロミズムで誘起される双極子の配向変化から生じる帯電処理に対する受容電位の変化を利用して、書き込み画像上にトナーを付着させ画像を形成する方法である。
【００７８】
図１に示したように、光を照射しない場合（図１における太線のヒステリシス曲線に相当）、強誘電性を示す液晶性基（メソゲン基）の自発分極の向きを同一方向に揃えた状態（ポーリング（双極子配向）処理）では、逆向きの電場をある一定の値（抗電場）まで印加しても自発分極の反転に基づく配向変化は起きない。
【００７９】
しかしながら、有機誘電体層が強誘電性を示す温度において光を照射した場合、ホトクロック化合物の分子構造が可逆的に変化し、その構造変化は、それを取り囲むメソゲン基の配列状態をも変化させる結果、強誘電性を示す液晶性基の双極子の配向状態が崩れ、光が照射された部分では、ヒステリシス曲線を示さなくなる。
【００８０】
即ち、有機誘電体層が強誘電性を示す温度において光を照射することによって、強誘電性を示す液晶性基の双極子の配向状態が崩れ、強誘電性特有の電気変位がゼロとなる結果、光照射部と未照射部の表面電荷密度が変化する現象を利用したものが本発明の画像形成方法Ｂである。
【００８１】
このように、光を用いて有機誘電体層に情報を書き込むことによって、有機誘電体層に情報を潜像として記録することができる。
【００８２】
また、本発明の画像記録方法Ｂによって潜像として有機誘電体層に記録された画像は、長期間保存することが可能である。
【００８３】
画像形成方法Ｂにおける記録された潜像を可視画像とする方法、ポーリング（双極子配向）処理、書込み画像の照射方法、画像の書込みに用いる光源、記録画像の保存条件は、本発明の画像記録方法Ａと同様の方法、条件又はものを用いることができる。
【００８４】
以下、本発明の画像形成方法Ｂを図３を用いて更に詳細に説明する。
【００８５】
図３の（１）は、本発明の画像記録方法Ｂの第１段階であって、導電層（４）を有する基板（５）上に有機誘電体層（３）を設けて成る本発明の誘電体記録素子に、コロナ帯電器（１）を用いて抗電場以上の電場を印加して有機誘電体層中の強誘電性を示す液晶性基（メソゲン基）の双極子（２）の自発分極の向きを電場方向に整列させた状態を模式的に示したものである。図３の（１）状態とした後、図３の（２）に示したように、有機誘電体層中に対し、誘電体層が強誘電性を示す温度でホトクロミズムを誘起する波長の光を用いて行う。書き込み時の有機誘電体層の温度は、有機誘電体層のキューリー点以下、又は、ガラス転移点以上であればよく、特に強誘電性を示す温度範囲内であれば、書き込み温度を有機誘電体層の自発分極が最大となる温度領域に設定することがより好ましい。
【００８６】
画像の書込み後は、図３の（３）に示したように、強誘電性を示す温度で有機誘電体層に静電粉体トナー又は液体トナーにより現像を行い、未露光部分にトナーが付着して、書き込み画像を現像することができる。可視画像のコントラストが低い場合は、必要に応じて、コロナ帯電で有機誘電体層全体を抗電場以下に帯電させることにより、静電コントラストを向上させて、可視画像のコントラストを改善することができる。
【００８７】
図３の（４）に示したように、有機誘電体層表面に現像されたトナー像は、普通紙やフィルムを重ねた後、普通紙やフィルム裏面を帯電させて静電的に普通紙やフィルムに静電トナーを転写させることができる。転写させた像は、一般の電子写真に用いられる方法で定着させることができる。
【００８８】
図３の（５）は、残存トナー及び物理吸着トナーを有機誘電体表面から除去した状態を表わし、この状態のまま、潜像を保存することができ、あるいは、図３の（３）のトナー現像工程に戻り、トナー像を転写させることを繰り返すことにより、多数枚の可視画像を形成することができる。
【００８９】
保存後は、図１−（３）のトナー現像工程より開始して記憶された潜像を可視化することができる。
【００９０】
【作用】
本発明の誘電体記録素子を用いた画像形成方法Ａでは、ポーリング（双極子配向）処理による強誘電性を示す化合物の双極子電界方向に配向させ、この配向状態を強誘電性特有の電気変位Ｄ−電界Ｅヒステリシス特性の自発分極をメモリー性として利用し、更にこの一定方向に双極子を配向させた有機誘電体層に抗電場以下の逆電場を印加しながら光で画像を書き込むことにより、ホトクロミズムで誘起される双極子の配向変化の反転が起こり、書き込み画像に対応した有機誘電体層の表面電荷密度の分布変化が現れ潜像として記録することができる。この双極子の配向方向の方向により静電トナーの吸引力に差が生じ、或は帯電処理による受容電位に差が生じ静電トナー現像することにより可視画像が得られる。これを通常の電子写真法により紙、又はフィルム等へ転写、定着し複写画像を得ることができる。更にこの潜像はメモリ性を有し一回の画像書き込みで連続して所望枚数の複写画像を得ることが、また、長期間安定に保たれるため、潜像として保存し必要なときに複写画像を得ることもできる。
【００９１】
また、本発明の誘電体記録素子を用いた画像形成方法Ｂでは、ポーリング処理による電界方向に対する双極子の配向を強誘電性の性質である自発分極として記憶させ、情報光の照射によりホトクロミック性を利用した光異性化に伴う双極子の配向の乱れで、光照射部分は、液晶相の相変化或いは常誘電性となり潜像が形成される。この強誘電性部と他の液晶相又は常誘電性部との間では、静電トナーの吸引力に差が生じ、或は、帯電処理等を行った場合、受容電位に差が生じる結果、静電トナーで現像することにより可視画像が得られる。可視化されたトナー画像は、一般の電子写真法により紙やフィルム等に転写が可能であり、更に、情報を潜像として記憶させることが可能であることから、一回の画像書き込みで連続して所望枚数の複写画像を得ることができ、又潜像として保存し必要な時に随時複写画像を得ることができる。
【００９２】
【実施例】
以下に、本発明の実施例を示し、本発明を更に具体的に説明する。しかしながら、本発明の実施例に限定されるものではない。
【００９３】
（合成例１）
（１−ａ）４’−エトキシ−４−アミノビフェニルの合成
４’−エトキシ−４−ニトロビフェニル２２．２ｇ（９２ミリモル）を酢酸エチル３００ｍｌに溶解し、１０％Ｐｄ／Ｃ １ｇを加えた。次いで、水素ガスを導入し、水素ガスの消費が停止するまで約１．５時間反応を行った。反応終了後、反応液から触媒を濾別し、濾液の濃縮を行なって４’−エトキシ−４−アミノビフェニル１８．６ｇを得た。（収率９５％）
【００９４】
（１−ｂ）４’−エトキシフェニル−４−ヒドロキシアゾベンゼンの合成
（１−ａ）で得た４’−エトキシ−４−アミノビフェニル化合物１２．８ｇ（６０ミリモル）、ジオキサン１００ｍｌ、濃塩酸１３ｍｌ及び水６５ｍｌの氷冷混合物中に、亜硝酸ナトリウム４．２ｇ（６０ミリモル）と水１０ｍｌから成る溶液を徐々に滴下した。滴下終了後、更に０℃で２時間攪拌を続けた。反応混合物を滴下ロートに移した後、反応混合物を、フェノール５．７ｇ（６０ミリモル）、水酸化ナトリウム２．９ｇ（６０ミリモル）、炭酸ナトリウム７．２ｇ及び水７８０ｍｌから成る混合液中に約１．５時間かけて滴下した。滴下終了後、更に１．５時間攪拌を続けた後、反応混合物を濃塩酸で中和した。次いで、反応生成物をエチルエーテルを用いて抽出した後、抽出液を濃縮し、カラムクロマトクラフィーを用いて抽出液の濃縮物を精製して４’−エトキシフェニル−４−ヒドロキシアゾベンゼン１５．３ｇを得た。（収率８０％）
【００９５】
（１−ｃ）｛４−（６−ヘキシルオキシ）−４’−（４−エトキシビフェニル）アゾベンゼン｝アクリレートの合成
（１−ｂ）で得た４’−エトキシフェニル−４−ヒドロキシアゾベンゼン１２．７ｇ（４０ミリモル）、アクリル酸６−ブロモヘキシルエステル１１ｇ（４５ミリモル）及び炭酸カリウム２２ｇ（１６０ミリモル）の混合物をアセトン中で１６時間加熱還流した。反応終了後、反応混合物を濾過し、濾液を濃縮し、カラムクロマトクラフィーを用いて濾液の濃縮物の精製を行ない｛４−（６−ヘキシルオキシ）−４’−（４−エトキシビフェニル）アゾベンゼン｝アクリレート９．４ｇを得た。（収率５０％）
【００９６】
（１−ｄ）ホトクロミズムを示す官能基を有する側鎖型高分子液晶化合物の合成（１−ｃ）で得た｛４−（６−ヘキシルオキシ）−４’−（４−エトキシビフェニル）アゾベンゼン｝アクリレート０．４ｇ（１．０ミリモル）、アゾビスイソブチルニトリル２．４ｍｇ及び乾燥テトラヒドロフラン１０ｍｌを凍結脱気した後、６０℃で２０時間反応させた。反応生成物を高速液体クロマトグラフィーを用いて精製して、式
【００９７】
【化８】

【００９８】
で表わされるアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する側鎖型高分子液晶化合物（重合度約９０００）０．３ｇを得た。
【００９９】
（合成例２）
（２−ａ）４−（４’−ヒドロキシフェニル）−安息香酸−１−メチルブチルの合成
４−（４’−ヒドロキシフェニル）安息香酸２１ｇ（０．１ミリモル）及び（Ｓ）−（−）−１−メチルブタノール４４ｇ（０．４モル）を濃硫酸２．１ｍｌの存在下に、ベンゼン１６０ｍｌ中で２５時間加熱還流した。反応終了後、反応液を濃縮し、カラムクロマトクラフィーを用いて反応液の濃縮物の精製を行ない４−（４’−ヒドロキシフェニル）−安息香酸−１−メチルブチル２６ｇを得た。（収率９５％）
【０１００】
（２−ｂ）｛４’−（６−ヘキシルオキシフェニル）安息香酸−１−メチルブチル｝アクリレートの合成
（２−ａ）で得た４−（４’−ヒドロキシフェニル）−安息香酸−１−メチルブチル４．３ｇ（１５ミリモル）、アクリル酸６−ブロモヘキシルエステル４．１ｇ（１７ミリモル）及び炭酸カリウム８．３ｇから成る混合物をアセトン中で１６時間加熱還流した。反応終了後、反応混合物を濾過し、濾液を濃縮し、カラムクロマトクラフィーを用いて濾液の濃縮物の精製を行ない｛４’−（６−ヘキシルオキシフェニル）安息香酸−１−メチルブチル｝アクリレート３．６ｇを得た。（収率５５％）
【０１０１】
（２−ｃ）強誘電性基とビフェニル骨格を有する液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物の合成
（２−ｂ）で得た｛４’−（６−ヘキシルオキシフェニル）安息香酸−１−メチルブチル｝アクリレート０．４ｇ（１．０ミリモル）、アゾビスイソブチルニトリル２．４ｇ及び乾燥テトラヒドロフラン１０ｍｌから成る混合物を乾燥脱気した後、６０℃で２０時間反応させた。反応終了後、反応生成物を高速液体クロマトグラフィーを用いて精製して、式
【０１０２】
【化９】

【０１０３】
で表わされる強誘電性基とビフェニル骨格を有する液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９６００）を０．３ｇ得た。
【０１０４】
（合成例３）
（３−ａ）ｐ−ニトロ安息香酸−１−メチルブチルの合成
ｐ−ニトロ安息香酸１６．７ｇ（０．１ミリモル）及び（Ｓ）−（−）−１−メチルブチルアルコール４４．２ｇ（０．５モル）を濃硫酸２ｍｌの存在下、ベンゼン１５０ｍｌ中で２５時間加熱還流した。反応終了後、反応液を濃縮し、カラムクロマトクラフィーを用いて反応液の濃縮物の精製を行ないｐ−ニトロ安息香酸−１−メチルブチル１９．０ｇを得た。（収率８０％）
【０１０５】
（３−ｂ）ｐ−アミノ安息香酸−１−メチルブチルの合成
（３−ａ）で得たｐ−ニトロ安息香酸−１−メチルブチル１８．５ｇ（７８ミリモル）を酢酸エチル３００ｍｌに溶解し、この溶液に１０％Ｐｄ／Ｃ １ｇを添加した後、水素ガスを導入し、その消費が停止するまで約５時間反応を行った。反応終了後、反応混合液を濾過し、濾液を濃縮することによって、ｐ−アミノ安息香酸−１−メチルブチル１３．７ｇを得た。（収率８５％）
【０１０６】
（３−ｃ）４’−ヒドロキシ−４−（１−メチルブチルカルボキシ）アゾベンゼンの合成
（３−ｂ）で得たｐ−アミノ安息香酸−１−メチルブチル１３ｇ（６０ミリモル）を、ジオキサン１０５ｍｌ、濃塩酸１３ｍｌ及び水６５ｍｌから成る混合液に氷冷しながら、混合し、亜硝酸溶液（亜硝酸ナトリウム４．２ｇ（６０ミリモル）／水１０ｍｌ）を徐々に滴下した。滴下終了後、０℃で約２時間攪拌した後、この溶液を、フェノール５．９ｇ（６０ミリモル）、水酸化ナトリウム２．４ｇ（６０ミリモル）、炭酸ナトリウム７ｇ及び水７８ｍｌから成る氷冷された混合液に約１．５時間かけて滴下した。滴下終了後、反応混合物を塩酸／氷水で中和した後、反応生成物をジエチルエーテルで抽出し、抽出液を濃縮し、カラムクロマトクラフィーを用いて抽出液の濃縮物の精製を行ない４’−ヒドロキシ−４−（１−メチルブチルカルボキシ）アゾベンゼン１４．７ｇを得た。（収率８１％）
【０１０７】
（３−ｄ）｛４’−（１０−デシルオキシ）−４−（１−メチルブチルカルボキシ）アゾベンゼン｝アクリレートの合成
（３−ｃ）で得た４’−ヒドロキシ−４−（１−メチルブチルカルボキシ）アゾベンゼン１２ｇ（４０ミリモル）、アクリル酸１０−ブロモデシルエステル１１ｇ（４５ミリモル）及び炭酸カリウム２２ｇ（０．１６モル）から成る混合物をアセトン中で１６時間加熱還流した。反応終了後、反応混合物を濾過し、濾液を濃縮し、カラムクロマトクラフィーを用いて濾液の濃縮物の精製を行ない｛４’−（１０−デシルオキシ）−４−（１−メチルブチルカルボキシ）アゾベンゼン｝アクリレート１０ｇを得た。（収率５０％）
【０１０８】
（３−ｅ）アゾベンゼン骨格から成るホトクロミズムを示す官能基と光学活性基を有する強誘電性液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物の合成
（３−ｄ）で得た｛４’−（１０−デシルオキシ）−４−（１−メチルブチルカルボキシ）アゾベンゼン｝アクリレート０．５ｇ（１ミリモル）、アゾビスイソブチルニトリル２．５ｍｇ及び乾燥テトラヒドロフラン１０ｍｌから成る混合物を凍結脱気した後、７０℃で２０時間反応させた。反応終了後、反応液を濃縮し、高速液体クロマトグラフィーを用いて、反応液の濃縮物の精製を行ない、式
【０１０９】
【化１０】

【０１１０】
で表わされるアゾベンゼン骨格から成るホトクロミズムを示す官能基と光学活性基を有する強誘電性液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９０００）０．２５ｇを得た。
【０１１１】
（合成例４）
（４−ａ）４’−ヒドロキシ−４−エトキシアゾベンゼンの合成
ｐ−エトキシアニリン８．０ｇ（６０ミリモル）、ジオキサン１００ｍｌ、濃塩酸１３ｍｌ及び水６５ｍｌから成る混合物を氷冷し、この氷冷混合物中に、水１０ｍｌ及び亜硝酸ナトリウム４．２ｇ（６０ｍｌ）から成る溶液を徐々に滴下した。滴下終了後、０℃で２時間攪拌した後、反応混合物を、フェノール５．７ｇ（６０ミリモル）、水酸化ナトリウム２．９ｇ（６０ミリモル）、炭酸ナトリウム７．２ｇ及び水７８０ｍｌから成る混合液中に約２時間かけて滴下した。滴下終了後、０℃で１時間攪拌した後、塩酸を用いて反応混合物を中和した。中和した反応混合物にエーテルを加えて、反応生成物をエチルエーテル抽出し、抽出液を濃縮し、カラムクロマトクラフィーを用いて抽出液の濃縮物の精製を行ない４’−ヒドロキシ−４−エトキシアゾベンゼン１０．９ｇを得た。（収率７５％）
【０１１２】
（４−ｂ）｛４’−（６−ヘキシルオキシ）−４−エトキシアゾベンゼン｝アクリレートの合成
（４−ａ）で得た４’−ヒドロキシ−４−エトキシアゾベンゼン９．７ｇ（４０ミリモル）、アクリル酸６−ブロモヘキシルエステル１１ｇ（４５ミリモル）及び炭酸カリウム２２ｇ（１６０ミリモル）から成る混合物をアセトン中で２０時間加熱還流した。反応終了後、反応混合物を濾過し、濾液を濃縮し、カラムクロマトクラフィーを用いて濾液の濃縮物の精製を行ない、式
【０１１３】
【化１１】

【０１１４】
で表わされるアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する液晶性基（メソゲン基）を有するアクリルモノマー６．６ｇを得た。（収率４５％）
【０１１５】
（合成例５）
（５−ａ）｛４’−（１０−デシルオキシ）−４−（１−メチルブチルカルボキシ）ビフェニル｝アクリレートの合成
合成例２の（２−ａ）で得た４−（４’−ヒドロキシフェニル）−安息香酸−１−メチルブチル１２．７ｇ（４０ミリモル）、アクリル酸１０−ブロモデシルエステル１４．６ｇ（５０ミリモル）及び炭酸カリウム２２ｇ（１６０ミリモル）から成る混合物をアセトン中で２０時間加熱還流した後、反応混合物を濾過し、濾液を濃縮し、カラムクロマトクラフィーを用いて濾液の濃縮物の精製を行ない、式
【０１１６】
【化１２】

【０１１７】
で表わされる光学活性基とビフェニル骨格を有する強誘電性基（メソゲン基）を有するアクリルモノマー（５−１）９．９ｇを得た。（収率５０％）
【０１１８】
（合成例６）
合成例４で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する液晶性基（メソゲン基）を有するアクリルモノマー及び合成例５で得た光学活性基とビフェニル骨格を有する強誘電性液晶性基（メソゲン基）を有するアクリルモノマーの５：９５（モル比）の混合物の２０重量％ベンゼン溶液に、アゾビスイソブチルニトリル２％を添加して真空脱気した後、反応容器を密封し、６０℃、４８時間放置して重合させて、式
【０１１９】
【化１３】

【０１２０】
で表されるアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する液晶性基（メソゲン基）と、強誘電性を示す液晶性基（メソゲン基）を有する共重合体から成る側鎖型高分子液晶を得た。
【０１２１】
（合成例７）
合成例３で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基と光学活性基を有する強誘電性液晶性基（メソゲン基）を有するアクリルモノマー及び合成例４で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する液晶性基（メソゲン基）を有するアクリルモノマーの５：９５（モル比）の混合物の２０重量％ベンゼン溶液に、アゾビスイソブチルニトリル２％を添加して真空脱気した後、反応容器を密封し、６０℃、４８時間放置して重合させて、式
【０１２２】
【化１４】

【０１２３】
で表わされるホトクロミズムを示すアゾベンゼン骨格を有する強誘電性メソゲン基とホトクロミズムを示すアゾベンゼン骨格のメソゲン基との共重合体である側鎖型強誘電性高分子液晶化合物（重合度：約９２００）を得た。
【０１２４】
（合成例８）
（８−ａ）ｐ−ブチルアニリンの合成
ｐ−ブチルニトロベンゼン１６．５ｇ（９２ミリモル）及び酢酸エチル３００ｍｌから成る溶液に、１０％Ｐｄ／Ｃ １ｇを加え、水素ガスをその消費が停止するまで約１．５時間反応を行った。反応終了後、反応液から触媒を濾別し、濾液の濃縮して、ｐ−ブチルアニリン１３ｇを得た。（収率９５％）
【０１２５】
（８−ｂ）４’−ブチル−４−ヒドロキシアゾベンゼンの合成
（８−ａ）で得たｐ−ブチルアニリン９ｇ（６０ミリモル）を、ジオキサン１００ｍｌ、濃塩酸１３ｍｌ、水６５ｍｌから成る氷冷混合物中に溶解し、この溶液を、亜硝酸ナトリウム４．２ｇ（６０ミリモル）及び水６０ｍｌから成る混合液に０℃にて徐々に滴下した。滴下終了後、０℃で２時間攪拌した後、この反応液を、フェノール５．９ｇ（６０ミリモル）、水酸化ナトリウム２．４ｇ（６０ミリモル）、炭酸ナトリウム７ｇ及び水７８ｍｌから成る氷冷された混合液に約２時間かけて滴下した。滴下終了後、反応混合物を塩酸で中和し、反応生成物をジエチルエーテルで抽出し、カラムクロマトクラフィーを用いて反応生成物の抽出液の精製を行ない、４’−ブチル−４−ヒドロキシアゾベンゼン１２ｇを得た。（収率８０％）
【０１２６】
（８−ｃ）４’−ブチル−４−メトキシアゾベンゼンの合成
（８−ｂ）で得た４’−ブチル−４−ヒドロキシアゾベンゼン７．６ｇ（３０ミリモル）をジメチルホルムアミド１００ｍｌに溶解し、この溶液に、炭酸カリウム１４ｇ（１００ミリモル）及び沃化メチル７．１ｇ（５０ミリモル）を添加し、７０℃で１時間攪拌した。反応混合物にメタノール５ｇを加え、更に７０℃で８時間反応させた。反応終了後、反応混合物を濾過し、反応生成物をエチルエーテル抽出し、抽出液を濃縮し、カラムクロマトクラフィーを用いて抽出物の精製を行ない、式
【０１２７】
【化１５】

【０１２８】
で表わされるアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する液晶化合物２．７ｇを得た。（収率３５％）
【０１２９】
（合成例９）
（９−ａ）４’−ヒドロキシ−４−（安息香酸−１−メチルブチル）アゾベンゼンの合成
合成例３の（３−ｂ）で得たｐ−アミノ安息香酸−１−メチルブチル１３ｇ（６０ミリモル）を、ジオキサン１０５ｍｌ、濃塩酸１３ｍｌ及び水６５ｍｌから成る混合液に混合した後、氷冷し、これに、亜硝酸ナトリウム４．２ｇ及び水１０ｍｌから成る溶液を徐々に滴下した。滴下終了後、０℃で２時間攪拌した。反応混合物を滴下ロートに移し、反応混合物を、ｐ−フェニルフェノール１０．２ｇ（６０ミリモル）、水酸化ナトリウム２．９ｇ（６０ミリモル）、炭酸ナトリウム７．２ｇ及び水７８ｍｌから成る混合液中に０℃で約２時間かけて滴下した。滴下終了後、更に０℃で１．５時間攪拌した。反応混合物を塩酸で中和した後、反応生成物をエチルエーテルで抽出し、抽出液を濃縮し、カラムクロマトクラフィーを用いて精製して４’−ヒドロキシ−４−（安息香酸−１−メチルブチル）アゾベンゼン１２．５ｇを得た。（収率７０％）
【０１３０】
（９−ｂ）｛４’−（１０−オキシ−１−デセン）｝−４’−（安息香酸１−メチルブチル）アゾベンゼンの合成
１０−ブロモ−１−デセン５．８ｇ（２６ミリモル）、（９−ａ）で得た４’−ヒドロキシ−４−（安息香酸−１−メチルブチル）アゾベンゼン８．５ｇ（２８ミリモル）及び炭酸カリウム４．０ｇをアセトン１００ｍｌ中で２０時間加熱還流した。反応終了後、反応混合物を濾過した後、濾液を濃縮し、カラムクロマトクラフィーを用いて濾液の濃縮物の精製を行ない、｛４’−（１０−オキシ−１−デセン）｝−４’−（安息香酸１−メチルブチル）アゾベンゼン９．４ｇを得た。（収率７７％）
【０１３１】
（９−ｃ）シロキサン結合から成る主鎖と、強誘電性基とアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する強誘電性液晶性基（メソゲン基）が結合した強誘電性を示す側鎖型高分子液晶化合物の合成
（９−ｂ）で得た｛４’−（１０−オキシ−１−デセン）｝−４’−（安息香酸１−メチルブチル）アゾベンゼン４．４ｇ（１０ミリモル）及びポリメチルヒドロシロキサン０．５ｇをトルエン５０ｍｌに溶解し、触媒として塩化白金酸６水和物５ｍｇを加え、アルゴン雰囲気下、８０℃で２４時間反応を行った。反応終了後、反応混合物をメタノールを用いて再沈澱させた後、沈澱物をジクロロメタンに溶解し、ジクロロメタン溶液を乾燥させ、濃縮して、式
【０１３２】
【化１６】

で表わされるシロキサン結合から成る主鎖と、強誘電性基とアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する強誘電性液晶性基（メソゲン基）が結合した強誘電性を示す側鎖型高分子液晶化合物（重合度：約９０００）を２．１ｇ得た。
【０１３３】
（合成例１０）
（１０−ａ）４’−（１０−オキシ−１−デセン）−４−（１−メチルブチルカルボキシ）ビフェニルの合成
合成例２の（２−ａ）で得た４−（４’−ヒドロキシフェニル）−安息香酸−１−メチルブチル８．５ｇ（３０ミリモル）、１０−ブロモ−１−デセン７．７ｇ（３５ミリモル）及び炭酸カリウム４．６ｇをアセトン中で２０時間還流した。反応終了後、反応混合物を濾過し、濾液を濃縮し、カラムクロマトクラフィーを用いて濾液の濃縮物の精製を行ない、４’−（１０−オキシ−１−デセン）−４−（１−メチルブチルカルボキシ）ビフェニル８．８ｇを得た。（収率７０％）
【０１３４】
（１０−ｂ）シロキサン結合から成る主鎖と、強誘電性基を有する強誘電性液晶性基（メソゲン基）が結合した強誘電性を示す側鎖型高分子液晶化合物の合成
（１０−ａ）で得た４’−（１０−オキシ−１−デセン）−４−（１−メチルブチルカルボキシ）ビフェニル４．２ｇ（１０ミリモル）及びポリメチルヒドロキシシロキサン０．５ｇをトルエン５０ｍｌに溶解し、触媒として塩化白金酸６水和物５ｍｇを加え、アルゴン雰囲気下で８０℃で３０時間反応を行った。反応終了後、反応混合物をメタノールを用いて再沈澱させた後、沈澱物をジクロロメタンに溶解させ、ジクロロメタン溶液を乾燥させ、濃縮して、式
【０１３５】
【化１７】

【０１３６】
で表わされるシロキサン結合から成る主鎖と、強誘電性基を有する強誘電性液晶性基（メソゲン基）が結合した強誘電性を示す側鎖型高分子液晶化合物（重合度：約１００００）２．０ｇを得た。
【０１３７】
（合成例１１）
合成例５の（５−ａ）で得た｛４’−（１０−デシルオキシ）−４−（１−メチルブチルカルボキシ）ビフェニル｝アクリレート２．５ｇ（５ミリモル）及び後述する合成例１２の（１２−ｃ）で得た１−（２−メタクリルオキシエチル）−６’−ニトロ−３，３’−ジメチルスピロ−［２Ｈ−１−ベンゾピラン−２，２’−インドリン０．１ｇ（０．２５モル）をジメチルホルムアミド１５ｍｌに溶解し、この溶液にアゾビスイソブチルニトリル５ｍｇを加え、真空脱気した後、６０℃で５０時間反応させた。反応終了後、反応混合物をメタノール中に滴下し、十分に攪拌した後、生じた沈澱を濾別し、乾燥させて、式
【０１３８】
【化１８】

【０１３９】
で表わされる側鎖に光学活性基とビフェニル骨格を有する強誘電性液晶性基（メソゲン基）及びスピロピラン骨格から成るホトクロミズムを示す官能基を有する強誘電性の側鎖型高分子液晶化合物（重合度約９３００、強誘電性メソゲン基の数とホトクロミズムを示す官能基の数の比が９５：５）１．２ｇを得た。
【０１４０】
（合成例１２）
（１２−ａ）１−ヒドロキシエチル−３，３−ジメチル−２−メチレンインドリンの合成
２，３，３−トリメチルインドリン２２ｇ（１３８ミリモル）と１−ヨードエタノール２８ｇ（１６２ミリモル）とを１００℃で３時間反応させた後、反応混合物に水酸化ナトリウム水溶液２８ｇを加えて、６０℃で６時間反応させた。反応生成物をベンゼンで抽出した後、抽出液を濃縮することによって、１−ヒドロキシエチル−３，３−ジメチル−２−メチレンインドリン３０．５ｇを得た。
【０１４１】
（１２−ｂ）１−ヒドロキシエチル−６’−ニトロ−３，３−ジメチルスピロ−［２Ｈ−１−ベンゾピラン］−２，２’−インドリンの合成
（１２−ａ）で得た１−ヒドロキシエチル−３，３−ジメチル−２−メチレンインドリン２８．０ｇ（１３８ミリモル）及び５−ニトロサリチルアルデヒド３０．３ｇ（１８２ミリモル）をエチルアルコール４００ｍｌ中で１００℃で２時間加熱還流下。反応終了後、反応混合物を濾過し、再結晶を行なって精製して１−ヒドロキシエチル−６’−ニトロ−３，３−ジメチルスピロ−［２Ｈ−１−ベンゾピラン］−２，２’−インドリン３４ｇを得た。（収率７０％）
【０１４２】
（１２−ｃ）１−（２−メタクリルオキシエチル）−６’−ニトロ−３，３’−ジメチルスピロ−［２Ｈ−１−ベンゾピラン−２，２’−インドリンの合成
（１２−ｂ）で得た１−ヒドロキシエチル−６’−ニトロ−３，３−ジメチルスピロ−［２Ｈ−１−ベンゾピラン］−２，２’−インドリン１２ｇ（３４ミリモル）及びピリジン１６ｍｌ（１８０ミリモル）を無水ベンゼン１００ｍｌに溶解し、この溶液を氷水で冷却しながら、この溶液にメタクリル酸クロライド８．９ｇ（９０ミリモル）を１時間かけて滴下し、滴下終了後、室温で１２時間反応させた。反応終了後、反応混合物を乾燥させ、濃縮し、カラムクロマトクラフィーを用いて反応混合物の精製を行ない、１−（２−メタクリルオキシエチル）−６’−ニトロ−３，３’−ジメチルスピロ−［２Ｈ−１−ベンゾピラン−２，２’−インドリン８．６ｇを得た。（収率６０％）
【０１４３】
（１２−ｄ）側鎖に光学活性基とアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する強誘電性液晶性基（メソゲン基）及びスピロピラン骨格から成るホトクロミズムを示す官能基を有する強誘電性の側鎖型高分子液晶化合物の合成
合成例３の（３−ｄ）で得た｛４’−（１０−デシルオキシ）−４−（１−メチルブチルカルボキシ）アゾベンゼン｝アクリレート１．５ｇ（３ミリモル）及び（１２−ｃ）で得た１−（２−メタクリルオキシエチル）−６’−ニトロ−３，３’−ジメチルスピロ−［２Ｈ−１−ベンゾピラン−２，２’−インドリン６０ｍｇ（０．１５ミリモル）をジメチルホルムアミド１０ｍｌに溶解し、この溶液にアゾビスイソブチルニトリル４．７ｍｇを加え、真空脱気した後、６０℃で５０時間反応させた。反応終了後、反応混合物を５００ｍｌのメタノール中に滴下し、十分に攪拌した後、生じた沈澱を濾取し、乾燥させて、式
【０１４４】
【化１９】

【０１４５】
で表わされる側鎖に光学活性基とアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する強誘電性液晶性基（メソゲン基）及びスピロピラン骨格から成るホトクロミズムを示す官能基を有する強誘電性の側鎖型高分子液晶化合物（重合度約９１００、メソゲン基とホトクロミック置換基の数の比９５：５）を得た。
【０１４６】
（合成例１３）
合成例１２の（１２−ｂ）で得た１−ヒドロキシエチル−６’−ニトロ−３，３−ジメチルスピロ−［２Ｈ−１−ベンゾピラン］−２，２’−インドリン１２ｇ（３４ミリモル）及びピリジン１６ｍｌ（１８０ミリモル）を無水ベンゼン１００ｍｌに溶解し、この溶液を氷水で冷却しながら、この溶液にイソ酪酸クロリド９．５ｇ（９０ミリモル）を１時間かけて滴下し、室温で１５時間反応させた。反応終了後、反応混合物を乾燥させ、濃縮し、カラムクロマトグラフィーを用いて精製して、式
【０１４７】
【化２０】

【０１４８】
で表わされるホトクロミズムを示すスピロピラン誘導体を得た。
【０１４９】
（実施例１）
合成例１で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する側鎖型高分子液晶化合物（重合度：約９０００）及び合成例２で得た強誘電性基とビフェニル骨格を有する液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９６００）の粉末を重量比で３：９７の割合で混合して得た組成物５部をクロロホルム溶媒５０部に完全に溶解させた後、ＩＴＯ付硝子基板上に乾燥後の膜厚が２μｍとなるように塗布した後、乾燥させて誘電体層を形成して、誘電体記録素子を得た。
【０１５０】
（実施例２）
合成例３で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基と光学活性基を有する強誘電性液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９０００）５部をクロロホルム１００部に溶解し、アルミニウム基板上にスピンコート法にて乾燥後の膜厚が２μｍとなるように塗布した後、乾燥させて有機誘電体層を形成して、誘電体記録素子を得た。
【０１５１】
（実施例３）
実施例２において、合成例３で得た高分子液晶化合物（重合度：約９０００）に代えて、合成例６で得たホトクロミズムを示すアゾベンゼン骨格を有する液晶性基（メソゲン基）と、強誘電性を示す液晶性基（メソゲン基）とを有する側鎖型高分子液晶を用いた以外は、実施例２と同様にして、アルミニウム基板上に有機誘電体層を形成して、誘電体記録素子を得た。
【０１５２】
（実施例４）
実施例２において、合成例３で得た高分子液晶化合物（重合度：約９０００）に代えて、合成例２で得た強誘電性基とビフェニル骨格を有する液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９６００）と合成例８で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する液晶化合物とを９７：３（重量比）で混合した組成物５部をクロロホルム５０部に溶解した溶液を用いた以外は、実施例２と同様にして、アルミニウム基板上に有機誘電体層を形成した。
【０１５３】
更に、この有機誘電体層上に、ポリカーボネート樹脂（三菱油化社製の「ＰＣＺ」）５部をジクロロメタン５００部に溶解して得た保護膜形成用塗料を乾燥後の膜厚が０．３μｍと成るようにスピンコーターを用いて塗布して保護膜を積層して誘電体記録素子を得た。
【０１５４】
（実施例５）
実施例２において、合成例３で得た高分子液晶化合物（重合度：約９０００）に代えて、合成例９で得たシロキサン結合から成る主鎖と、強誘電性基とアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する強誘電性液晶性基（メソゲン基）が結合した強誘電性を示す側鎖型高分子液晶化合物（重合度：約９０００）９５部と合成例８で得たホトクロミズムを示すアゾベンゼン誘導体５部との混合物５部をクロロホルム５０部に溶解した溶液を用いた以外は、実施例２と同様にして、アルミニウム基板上に有機誘電体層を形成した。
【０１５５】
更に、有機誘電体層上に、実施例４と同様にして膜厚０．３μｍの保護膜を積層して誘電体記録素子を得た。
【０１５６】
（実施例６）
実施例２において、合成例３で得た高分子液晶化合物（重合度：約９０００）に代えて、合成例９で得たシロキサン結合から成る主鎖と、強誘電性基とアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する強誘電性液晶性基（メソゲン基）が結合した強誘電性を示す側鎖型高分子液晶化合物（重合度：約１００００）５部及び合成例１０で得たシロキサン結合から成る主鎖と、強誘電性基を有する強誘電性液晶性基（メソゲン基）が結合した強誘電性を示す側鎖型高分子液晶化合物（重合度：約１００００）の粉末９５部から成る混合物５部をクロロホルム５０部に溶解した溶液を用いた以外は、実施例２と同様にして、アルミニウム基板上に有機誘電体層を形成して、誘電体記録素子を得た。
【０１５７】
（実施例７）
アルミニウム基板の表面に、ポリアミック酸（日立化成社製「ＰＩＸ５０００」）のＮ−メチル−２−ピロリドン溶液をスピンコート法で塗布し、加熱硬化させ約０．３μｍのポリアミド薄膜を形成した後、ホモジニアス配向が得られるようにラビング処理を行った。
【０１５８】
実施例２において、合成例３で得た高分子液晶化合物（重合度：約９０００）に代えて、合成例９で得たシロキサン結合から成る主鎖と、強誘電性基とアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する強誘電性液晶性基（メソゲン基）が結合した強誘電性を示す側鎖型高分子液晶化合物（重合度：約９０００）５部をクロロホルム５０部に溶解した溶液を用い、アルミニウム基板として、上記ラビング処理を施したアルミニウム基板を用いた以外は、実施例２と同様にして、有機誘電体層を形成して、誘電体記録素子を得た。
【０１５９】
（実施例８）
実施例２において、合成例３で得た高分子液晶化合物（重合度：約９０００）に代えて、合成例１１で得た側鎖に光学活性基とビフェニル骨格を有する強誘電性液晶性基（メソゲン基）及びスピロピラン骨格から成るホトクロミズムを示す官能基を有する強誘電性の側鎖型高分子液晶化合物（重合度約９３００、強誘電性メソゲン基の数とホトクロミズムを示す官能基の数の比が９５：５）５部をクロロホルム５０部に溶解した溶液を用いた以外は、実施例２と同様にして、アルミニウム基板上に有機誘電体層を形成して、誘電体記録素子を得た。
【０１６０】
（実施例９）
実施例２において、合成例３で得た高分子液晶化合物（重合度：約９０００）に代えて、合成例１２で得た側鎖に光学活性基とアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する強誘電性液晶性基（メソゲン基）及びスピロピラン骨格から成るホトクロミズムを示す官能基を有する強誘電性の側鎖型高分子液晶化合物（重合度約９１００、メソゲン基とホトクロミック置換基の数の比９５：５）５部をクロロホルム５０部に溶解した溶液を用いた以外は、実施例２と同様にして、アルミニウム基板上に有機誘電体層を形成して、誘電体記録素子を得た。
【０１６１】
（実施例１０）
実施例２において、合成例３で得た高分子液晶化合物（重合度：約９０００）に代えて、合成例２で得た強誘電性基とビフェニル骨格を有する液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９５００）と合成例８で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する液晶化合物とを９７：３（重量比）で混合した組成物５部をクロロホルム５０部に溶解した溶液を用いた以外は、実施例２と同様にして、アルミニウム基板上に有機誘電体層を形成した。
【０１６２】
更に、有機誘電体層上に、実施例４と同様にして膜厚０．３μｍの保護膜を積層して誘電体記録素子を得た。
【０１６３】
（実施例１１）［本発明の画像形成方法Ａの実施例］
実施例１〜１０で得た各誘電体記録素子に＋８ＫＶのコロナ電圧をかけたコロナ帯電器により帯電させて、誘電体層のポーリング（双極子配向）処理を行った。
【０１６４】
次に、ポーリング処理を行った誘電体層に、ポーリング処理時とは逆の極性である−５ＫＶのコロナ電圧をかけたコロナ帯電器により帯電（抗電界以下）を行いながらアゾベンゼン誘導体の光異性化波長である３６５ｎｍの紫外光を照射し画像書き込みを行い、各誘電体記録素子の誘電体層に潜像を形成した。
【０１６５】
誘電体層に形成された潜像を、正極性の粉体トナーを用いて磁気ブラシ現像を行ったところ、いずれの誘電体記録素子においても、非露光部にトナーが付着し可視化された。これを紙にコロナ転写、定着を行った結果、良好な画像が得られた。また、転写後、残留トナーをクリーニングし、再びトナー現像、転写、定着を繰返し行なった結果、いずれの誘電体記録素子においても、複数枚の初期と変わらない画像が得られた。
【０１６６】
また、この潜像を３ケ月間暗所に保存した後、再びトナー現像、転写、定着を行った結果、いずれの誘電体記録素子においても、初期の画像と同様な画像が得られ、潜像として長期間安定に保存されることを確認した。
【０１６７】
更に、それぞれの誘電体記録素子の誘電体層に可視光（波長４４０ｎｍ）を十分照射し、前記のポーリング（双極子配向）処理を行った結果、いずれの誘電体記録素子においても、書き込み画像が完全に消去された。
【０１６８】
（実施例１２）
実施例１において、合成例１で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する側鎖型高分子液晶化合物（重合度：約９０００）及び合成例２で得た強誘電性基とビフェニル骨格を有する液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９６００）の粉末との混合割合を重量比で５：９５とし、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例１と同様にして、誘電体記録素子を得た。
【０１６９】
（実施例１３）
実施例２において、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例２と同様にして、誘電体記録素子を得た。
【０１７０】
（実施例１４）
実施例３において、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例３と同様にして、誘電体記録素子を得た。
【０１７１】
（実施例１５）
実施例４において、合成例２で得た強誘電性基とビフェニル骨格を有する液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９６００）と合成例８で得たアゾベンゼン骨格から成るホトクロミズムを示す官能基を有する液晶化合物との混合割合を重量比で９５：５とし、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例４と同様にして、誘電体記録素子を得た。
【０１７２】
（実施例１６）
実施例５において、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例５と同様にして、誘電体記録素子を得た。
【０１７３】
（実施例１７）
実施例７において、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例７と同様にして、誘電体記録素子を得た。
【０１７４】
（実施例１８）
実施例８において、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例８と同様にして、誘電体記録素子を得た。
【０１７５】
（実施例１９）
実施例９において、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例９と同様にして、誘電体記録素子を得た。
【０１７６】
（実施例２０）
実施例２において、合成例３で得た高分子液晶化合物に代えて、合成例７で得たホトクロミズムを示すアゾベンゼン骨格を有する強誘電性メソゲン基とホトクロミズムを示すアゾベンゼン骨格のメソゲン基との共重合体である側鎖型強誘電性高分子液晶化合物（重合度：約９２００）を使用し、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例２と同様にして、誘電体記録素子を得た。
【０１７７】
（実施例２１）
実施例２において、合成例３で得た強誘電性基とビフェニル骨格を有する液晶性基（メソゲン基）を側鎖に有する高分子液晶化合物（重合度：約９６００）９５部と合成例１３で得たホトクロミズムを示すスピロピラン誘導体５部との混合物を使用し、ＩＴＯ付硝子基板に代えて１０×１０cmのアルミニウム基板を用いた以外は、実施例２と同様にして、誘電体記録素子を得た。
【０１７８】
（実施例２３）［本発明の画像形成方法Ｂの実施例］
実施例１２〜２２で得た各誘電体記録素子の有機誘電体層の表面に、基板と同一の大きさのアルミニウム電極を密着させ、表１に示した温度に加熱しながら７０Ｖ直流電圧を印加して、有機誘電体層のポーリング処理を行った。ポーリング処理用のアルミニウム電極を取り除いた後、メタルハライドランプを用いて、この各誘電体記録素子の有機誘電体層の表面にテストパターンを投影して露光した。投影後、負のコロナ放電により各誘電体記録素子の有機誘電体層の表面を帯電させ、トナー現像した結果、未露光部分にトナー付着して書き込んだ潜像を可視化することができた。このトナー画像を普通紙にコロナ転写させ定着したところ、各誘電体記録素子において、良好な画像が得られた。更に、未転写トナーを除去した後、再び、コロナ帯電を行ない、トナー現像、コロナ転写させた結果、各誘電体記録素子のすべてにおいて、初回と同様の良好な画像が得られた。更に、各誘電体記録素子において、同様の操作を繰り返して複写できることを確認した。
【０１７９】
また、各誘電体記録素子に形成された潜像は、３ヶ月以上室温暗所で保存した後、再びトナー現像、転写、定着を行ったところ、各誘電体記録素子において、初期の画像と同等な画像が得られ、潜像として長期間安定に保存できることを確認することができた。
【０１８０】
潜像が形成された各誘電体記録素子に可視光（４４０ｎｍ）を十分照射して再び７０Ｖの直流電圧を印加したところ、潜像が完全に消去されることを確認することができた。
【０１８１】
【表１】

【０１８２】
【発明の効果】
本発明の誘電体記録素子は、有機誘電体層に、二つの機能であるホトクロミズムによる光応答性及び強誘電性によるメモリー性を融合させることで、光書き込み可能なメモリー性を有する。
【０１８３】
また、本発明の誘電体記録素子を用いた画像形成方法によれば、光書き込みにより潜像を形成し、これをトナー現像により可視化でき、紙、フィルム等にコロナ転写することにより複写画像が形成できる。
【０１８４】
また、光書き込みにより形成された潜像は、長期間安定に保存可能である。更に、光異性化の速度で書き込みが可能であり、その結果、高速化が計られ、分子レベルでの高密度書き込み、高解像力化が計られる。
【０１８５】
また、一度書き込まれた潜像は環境に対して安定であり、長期間の保存が可能で、随時、情報の書き込み、修正、消去が可能である。
【０１８６】
また、多数枚の同一の可視画像の形成においては、潜像のメモリー性を利用して、一度画像の書き込みを行なって潜像を形成すれば、トナー現像−転写−定着（クリーニング）の工程を繰り返すことにより所望枚数の可視画像の形成が可能である。
【０１８７】
また、本発明の可視画像の現像は、通常の電子写真法が適用できるため、カラー画像の形成も可能である。
【図面の簡単な説明】
【図１】本発明の誘電体記録素子における印加電界（Ｅ）と電気変位（Ｄ）の関係を示すヒステリシス曲線図表である。
【図２】本発明の誘電体記録素子を用いる画像形成方法Ａの工程説明図である。
【符号の説明】
１ コロナ帯電器
２ 双極子
３ 有機誘電体層
４ 導電層
５ 基板
６ 静電トナー
７ 紙
【図３】本発明の誘電体記録素子を用いた画像形成方法Ｂの工程説明図。
【符号の説明】
１ コロナ帯電器
２ 双極子
３ 有機誘電体層
４ 導電層
５ 基板
６ 配向変化の場合
７ 液晶相変化の場合
８ 静電トナー
９ 紙[0001]
BACKGROUND OF THE INVENTION
The present invention is a dielectric recording element capable of forming a latent image by writing an image by light irradiation and visualizing the latent image by electrophotography, and can store the formed latent image for a long period of time. The present invention relates to a dielectric recording element capable of copying sheets.
[0002]
[Prior art]
In general, electrophotography, which is one of the image forming methods used in copying machines and printers, charges the surface of a photoconductor, and then performs image exposure and toner development processing to obtain a toner image on the photoconductor. Is transferred onto a film or plain paper, and the transferred toner image is fixed to form a visible image. In order to form the same visible image again, the toner adhering to the photoconductor is cleaned and then charged again, and then the same steps such as image exposure transfer and fixing are repeated.
[0003]
Currently, the electrophotographic recording method uses a photosensitive member having a photosensitive layer made of a photoconductor to form an electrostatic latent image on the photosensitive layer of the photosensitive member by charging and image exposure. A visible image is formed by developing, transferring, and fixing with electrostatic toner. In order to create a plurality of the same images, all of the above steps must be repeated. Therefore, when a plurality of the same images are created, the copying speed is limited, and high speed copying is difficult.
[0004]
In order to solve this problem, “Photographic Science and Engineering” Vol. 25 (1981), pages 35 to 39 and pages 209 to 215 include electronic devices with memory characteristics. Photoconductors have been proposed. According to this method, if image exposure is performed once, a plurality of copies can be made by repeating the steps from development to fixing thereafter. However, the electrophotographic photosensitive member described in this document cannot store a latent image formed by image exposure for a long period of time, has a problem in memory properties, and cannot be stored in a bright room. The printability and environmental stability are also poor, and it has not been put into practical use.
[0005]
Also, a ferromagnetic material is used to form a memory-like latent image depending on the magnitude of its magnetic susceptibility, development is performed using magnetic toner, transfer and fixing are performed, and a plurality of visible images can be obtained by writing an image once. Printers {ReproMG8000 (manufactured by Iwasaki Tsushinki), VaripressM450 (manufactured by Bull-Nipson)} are in practical use. However, since this method uses a magnetic head as a writing head, there is a limit to the resolving power, and since it is difficult to produce a color magnetic toner, it has a fatal defect that a color image cannot be created.
[0006]
Further, JP-A-5-221139 proposes a recording method capable of continuous copying and storage of a latent image by employing a recording element using an organic ferroelectric. However, in this method, after the organic dielectric layer is subjected to poling (dipole orientation) treatment, light is irradiated during image writing, and the exposed portion is heated to a Curie point (Tc) or more to form a latent image. It is difficult to improve recording density and resolving power due to heat diffusion and the like. Furthermore, since the writing part is heated above the Curie point, there is a problem in durability.
[0007]
[Problems to be solved by the invention]
The problem to be solved by the present invention is that a large number of visible images can be formed by a single image exposure, colorization, high speed, long-term stable storage of latent images, high resolution, etc. are possible. It is an object of the present invention to provide a recording element capable of writing and erasing as needed, and an image forming method using the recording element.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention A dielectric recording element comprising an organic dielectric layer exhibiting ferroelectricity and photochromism on a substrate having a conductive layer I will provide a.
[0009]
Further, in order to solve the above-mentioned problems, the present invention applies an electric field to the dielectric recording element having the above configuration to align the dipoles of the organic dielectric layer in the same direction and By irradiating light while applying a reverse electric field, (1) it is caused by the difference in the orientation direction of the dipole in the organic dielectric layer accompanying the reversal of the orientation direction of the dipole induced by the photochromism of the irradiated portion. By subjecting the organic dielectric layer having a difference in surface charge density caused by the difference in surface charge density or (2) reversal of the orientation direction of dipoles induced by photochromism of the light-irradiated portion to further charging treatment An image forming method (hereinafter referred to as “image forming method A of the present invention”) in which a visible image is formed by adhering electrostatic toner using the difference in receptive potential generated is provided.
[0010]
Furthermore, in order to solve the above-mentioned problems, the present invention provides a dielectric recording element having the above-described configuration, wherein an electric field is applied to align the dipoles of the organic dielectric layer in the same direction, and then the dielectric layer Caused by optical writing at a temperature showing the ferroelectricity of Using the change in the receptive potential for the charging process resulting from the change in orientation of the dipole induced by photochromism of the writing part by light An image forming method (hereinafter referred to as image forming method B of the present invention) for forming an image by attaching toner onto a written image is provided.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the dielectric recording element of the present invention, the material constituting the organic dielectric layer described later is dissolved in an organic solvent such as chloroform and acetone, and the solution is dipping, bar coating, roll coating, spray coating, It can be manufactured by applying a dry film thickness of several tens of μm or less onto a substrate having a conductive layer by spin coating or the like.
[0012]
The support constituting the dielectric recording element of the present invention may be any support as long as it has the necessary mechanical strength and smoothness and has conductivity, and is also suitable for plastics, paper, and other insulating substrates. A laminate of conductive films may be used. In addition, the conductive film is a polyimide alignment film that has been subjected to a rubbing alignment process that is rubbed in a certain direction with fibers such as nylon, or SiO ₂ An alignment film formed by oblique vapor deposition may be provided as necessary, and any film may be used as long as a treatment for obtaining homogeneous alignment is performed on the surface.
[0013]
By using the substrate subjected to the orientation treatment for the dielectric recording element of the present invention, the orientation of the dipole by the poling (dipole orientation) treatment is assisted, and the orientation by the poling (dipole orientation) treatment is more easily performed. be able to.
[0014]
The organic dielectric layer exhibiting ferroelectricity and photochromism constituting the dielectric recording element of the present invention comprises, for example, (1) a composition comprising a compound exhibiting photochromism and a compound exhibiting ferroelectricity, (2) A side chain type polymer liquid crystal having a substituent having ferroelectricity and a functional group exhibiting photochromism in the side chain, (3) Liquid crystalline group (mesogen group) exhibiting ferroelectricity and photochromism (4) a liquid crystal group having ferroelectricity having a functional group exhibiting photochromism as one constituent element (a liquid crystal group having a functional group exhibiting photochromism) And those composed of a side chain type polymer liquid crystal having a mesogenic group) in the side chain.
[0015]
As the organic dielectric layer (1) comprising a composition containing a compound exhibiting photochromism and a compound exhibiting ferroelectricity, for example,
(1-a) an organic dielectric layer comprising a composition of a side-chain polymer liquid crystal (A) exhibiting ferroelectricity and a polymer compound (B) having a functional group exhibiting photochromism;
(1-b) a side-chain polymer liquid crystal (A) having ferroelectricity and a side-chain polymer liquid crystal having a functional group having a photochromism having a liquid crystal group (mesogen group) at the terminal in the side chain ( An organic dielectric layer comprising a composition with C),
Etc.
[0016]
As the organic dielectric layer (2) composed of a side chain type polymer liquid crystal having a substituent exhibiting ferroelectricity and a functional group exhibiting photochromism in the side chain, for example,
(2-a) a copolymer of a copolymerizable vinyl monomer (D) having a liquid crystalline group (mesogen group) exhibiting ferroelectricity and a copolymerizable monomer (E) having a functional group exhibiting photochromism An organic dielectric layer,
(2-b) a copolymerizable vinyl monomer (D) having a liquid crystalline group (mesogen group) exhibiting ferroelectricity and a functional group exhibiting photochromism having a liquid crystalline group (mesogen group) at the terminal Examples thereof include an organic dielectric layer composed of a copolymer with a copolymerizable vinyl monomer (F).
[0017]
In any case, in the functional group showing photochromism, the difference in molecular arrangement due to photoisomerization affects the mobility and orientation direction of the mesogenic group of the ferroelectric polymer liquid crystal. By utilizing this phenomenon, the hysteresis curve of the ferroelectric polymer liquid crystal to be used can be changed.
[0018]
In the side chain type polymer liquid crystal (A) showing ferroelectricity, the side chain liquid crystal group (mesogen group) constituting the side chain type polymer liquid crystal has a functional group showing ferroelectricity. Specifically, an optically active group is present in the terminal group of the liquid crystal group (mesogenic group) or the bonding group that connects the terminal group and the ring.
[0019]
The side chain type polymer liquid crystal is, for example, (1) a polymerizable composition containing a copolymerizable vinyl monomer having a liquid crystalline group (mesogenic group) in the presence of a catalyst such as AIBM (azobisisobutylnitrile). (2) A method of polymerizing a monomer having a liquid crystal group (mesogen group) and having an epoxy group at the terminal in the presence of a catalyst such as stannic chloride, or (3) a liquid crystal group ( It can be produced by a method of directly bonding a mesogenic group) to the main chain of the polymer, but may be produced by a method other than these.
[0020]
The liquid crystalline group (mesogenic group) which is the side chain of the side chain type polymer liquid crystal has a molecular structure of the mesogenic group, in which two ring structure groups are bonded via a central bonding group in the core part of the molecular structure. One of the ends has a terminal substituent, and the other is bonded to the main chain of the polymer via a spacer such as a methylene group. Examples of the terminal substituent include an electron-donating alkyl group, an electron-withdrawing halogen group, a cyano group, an optically active group containing an asymmetric carbon atom, and a branched carbon chain. The ring structure of the core part of the mesogenic group preferably has a ring structure of two or more rings, such as paraphenylene, condensed ring, heterocyclic ring, non-six-membered ring, saturated ring, heterocyclic ring, etc. The ring structure may have a halogen, an alkyl group, a cyano group, or the like. Examples of the central bond group of the core part include a triple bond, a double bond, a single bond, an ester, an ether bond, and the like, and two or more rings are connected to form the core part of the mesogenic group.
[0021]
Examples of the optically active group constituting the side chain type polymer liquid crystal exhibiting ferroelectricity include alkyl, alkoxy, ester, reverse ester, and cinnamate type, and specifically, optically active 1-methylbutyl. Group, optically active 2-methylbutyl group, optically active 2-methylbutoxy group, optically active 4-methylhexyl group, optically active epoxy group and the like. Further, a hydrogen atom or an alkyl group bonded to an asymmetric carbon atom may be halogenated. Further, it may be an optically active group having a ring structure having an asymmetric carbon atom, and examples thereof include an optically active lactone ring, an optically active dioxane ring, an optically active oxazolidone ring, an optically active hydrofuran ring, and an optically active cyanocyclopropane ring. . Any optically active group may have a structure in which a dipole moment component is formed in a direction perpendicular to the major axis direction of the liquid crystal group (mesogen group), and the liquid crystal phase exhibits a layer structure, Ferroelectricity can be obtained by showing a liquid crystal phase in which a liquid crystal group (mesogen) group is inclined with respect to the normal direction of the layer. The chain length of the terminal substituent of the optically active group is preferably 3 or more.
[0022]
In a side-chain polymer liquid crystal exhibiting ferroelectricity, the type of desired liquid crystal phase can be adjusted by adjusting the number of ring structures, the presence or absence of substituents in the ring structure, the length of spacers and the number of carbon atoms in the terminal substituents. In addition, a material having a phase series and a temperature range can be obtained. In addition, a side chain type polymer liquid crystal having no asymmetric carbon atom, or at least one other side chain type polymer liquid crystal exhibiting ferroelectricity is replaced with another side chain type liquid crystal exhibiting other ferroelectricity. It can be mixed with a polymer liquid crystal to obtain a desired liquid crystal phase, phase sequence, and temperature range. When mixing at least two types of side-chain polymer liquid crystals exhibiting ferroelectricity, the direction of the spontaneous polarization represented by the liquid crystalline group (mesogenic group) is classified as positive and negative. It is desirable to mix compounds with the same direction of spontaneous polarization of the liquid crystal group (mesogen group) used in the portion, and if necessary, the twist direction of the spiral indicated by the liquid crystal group (mesogen group) used in the side chain portion However, by adjusting the mixing ratio of the right-facing material and the left-facing material, the spiral pitch can be adjusted or the spiral can be solved.
[0023]
Examples of the polymer compound other than the acrylic resin constituting the main chain portion of the side chain type polymer liquid crystal include polysiloxane, polyepichlorohydrin, polystyrene, polypeptide, polyphosphazene, polyethylene, A polyethyleneimine type, a polyvinyl type, etc. are mentioned.
[0024]
As a method for introducing a liquid crystalline group (mesogenic group) into the side chain of these polymer compounds, for example, in the case of a polysiloxane system, the terminal has a vinyl group and a liquid crystalline group (mesogenic group) via a spacer. And a monomer having a hydroxyl group such as polymethylhydrogensiloxane and a polysiloxane polymer having a hydroxyl group in the presence of a catalyst such as platinum chloride.
[0025]
The polymer compound (B) having a functional group exhibiting photochromism is obtained by replacing the liquid crystal group (mesogenic group) with a photo-functional group in the above-described method for producing a side-chain polymer liquid crystal (A) exhibiting ferroelectricity. It can be easily produced by using a material having a functional group exhibiting chromism.
[0026]
The functional group exhibiting photochromism may be any one in which a part of the molecular structure reversibly induces a photogeometric isomerization reaction by the action of light. For example, those having a structure causing photogeometric isomerization reaction such as azobenzene, stilbene, indigo or thioindigo, or those causing photoelectron ring-opening reaction such as spiropyran, spirooxazine, and fluoride may be used.
[0027]
Examples of the functional group exhibiting such photochromism include the following.
[0028]
[Chemical 1]

[0029]
[Chemical 2]

[0030]
The side chain type polymer liquid crystal (C) having a liquid crystal group (mesogen group) at the end and having a functional group showing photochromism in the side chain is a side chain type polymer liquid crystal showing ferroelectricity as described above ( In the production method of A), instead of a liquid crystal group (mesogen group) having a functional group exhibiting ferroelectricity, a material having a liquid crystal group (mesogen group) at the terminal and having a functional group exhibiting photochromism By using it, it can be manufactured easily.
[0031]
Examples of the functional group exhibiting photochromism having a liquid crystal group (mesogen group) at the terminal include the following.
[0032]
[Chemical 3]

[0033]
[Formula 4]

[0034]
[Chemical formula 5]

[0035]
In the case of the organic dielectric layer (1) composed of a composition containing a compound exhibiting photochromism and a compound exhibiting ferroelectricity, the proportion of the compound exhibiting photochromism in the composition is 0.1-50 mol%. A range is preferred. When the proportion of the compound exhibiting photochromism is more than 50 mol%, the response speed at the time of optical writing is increased, but the spontaneous polarization of the ferroelectric layer is reduced, and as a result, an image having sufficient contrast cannot be obtained. Since it is in a tendency, it is not preferable. In addition, when the proportion of the compound exhibiting photochromism is less than 0.1 mol%, the spontaneous polarization of the ferroelectric layer increases, but the response speed at the time of optical writing becomes slow, and as a result, the orientation change of the dipole is reduced. This is not preferable because it does not occur sufficiently and an image having sufficient contrast tends not to be obtained.
[0036]
Examples of the copolymerizable vinyl monomer (D) having a liquid crystal group (mesogen group) exhibiting ferroelectricity include an acrylic monomer or a vinyl monomer having a liquid crystal group (mesogen group) exhibiting ferroelectricity. As the liquid crystalline group (mesogen group) exhibiting ferroelectricity, those described in the method for producing the side chain polymer liquid crystal (A) exhibiting ferroelectricity can be used.
[0037]
Examples of the copolymerizable monomer (E) having a functional group exhibiting photochromism include acrylic monomers and vinyl monomers having a functional group exhibiting photochromism. What was demonstrated in the manufacturing method of the high molecular compound (B) which has a functional group which shows a photochromism can be used for the functional group which shows a photochromism.
[0038]
A copolymerizable vinyl monomer (F) having a liquid crystal group (mesogen group) at the end and a functional group exhibiting photochromism has a liquid crystal group (mesogen group) at the end and has a function exhibiting photochromism. Examples thereof include an acrylic monomer or a vinyl monomer having a group. A functional group exhibiting a photochromism having a liquid crystal group (mesogen group) at the terminal is a side chain polymer liquid crystal having a liquid crystal group (mesogen group) at the terminal and a functional group exhibiting photochromism in the side chain ( What was demonstrated in the manufacturing method of C) can be used.
[0039]
A side chain polymer liquid crystal (3) having a substituent in which a liquid crystal group exhibiting ferroelectricity (mesogen group) and a functional group exhibiting photochromism are bonded to the side chain is a side chain type exhibiting ferroelectricity. In this polymer liquid crystal (A), a functional group exhibiting photochromism is introduced between a liquid crystalline group (mesogen group) exhibiting ferroelectricity and the main chain of the polymer. This side chain polymer liquid crystal (3) is a liquid crystal group (mesogenic group) having a functional group exhibiting ferroelectricity in the above-described method for producing a side chain polymer liquid crystal (A) exhibiting ferroelectricity. Instead, it can be easily produced by using a material having a functional group exhibiting photochromism to which a liquid crystalline group exhibiting ferroelectricity (mesogen group) is bonded.
[0040]
Examples of the functional group exhibiting photochromism to which a liquid crystalline group exhibiting ferroelectricity (mesogen group) is bonded include the following.
[0041]
[Chemical 6]

[0042]
A side-chain polymer liquid crystal (4) having a ferroelectric liquid crystal group (mesogen group) in the side chain, the functional group exhibiting photochromism as a constituent element, is a side-chain type liquid crystal exhibiting ferroelectricity. In the polymer liquid crystal (A), it is a material in which a functional group showing photochromism is introduced into a liquid crystalline group (mesogen group) showing ferroelectricity. This side chain polymer liquid crystal (4) is a liquid crystal group (mesogen group) having a functional group exhibiting ferroelectricity in the above-described method for producing a side chain polymer liquid crystal (A) exhibiting ferroelectricity. In place of (), a material having a liquid crystalline group (mesogen group) exhibiting ferroelectricity into which a functional group exhibiting photochromism is introduced can be used for easy production.
[0043]
Examples of the liquid crystalline group (mesogenic group) having ferroelectricity into which a functional group exhibiting photochromism is introduced include the following.
[0044]
[Chemical 7]

[0045]
When the organic dielectric layer (2) composed of a side chain type polymer liquid crystal having a substituent exhibiting ferroelectricity and a functional group exhibiting photochromism in its side chain is used, the ratio of the functional group exhibiting photochromism is 0. The range of 2-50 mol% is preferable, and the range of 0.5-20 mol% is particularly preferable. When the ratio of the functional group exhibiting photochromism is more than 50 mol%, the response speed at the time of optical writing is increased, but the spontaneous polarization of the ferroelectric layer is reduced, and as a result, an image having sufficient contrast is obtained. Since it tends to disappear, it is not preferable. When the proportion of the functional group exhibiting photochromism is less than 0.2 mol%, the spontaneous polarization of the ferroelectric layer increases, but the response speed during optical writing becomes slow, and as a result, the orientation change of the dipole is sufficient. This is not preferable because it does not occur and an image having sufficient contrast cannot be obtained.
[0046]
A functional group exhibiting photochromism is introduced as a terminal substituent of a liquid crystalline group (mesogen group), a part of a spacer, or a central bonding group, and the functional group exhibiting photochromism causes a photogeometric isomerization reaction, thereby producing a liquid crystal. Liquid crystallinity can be imparted by the rod structure of the steric structure of the functional group (mesogenic group). Further, by adjusting the presence / absence of a substituent in the ring structure, the length of the spacer, or the number of carbon atoms of the terminal substituent, a desired liquid crystal phase type, phase sequence, and temperature range can be obtained.
[0047]
When the compound that constitutes the organic dielectric layer of the dielectric recording element of the present invention exhibits a liquid crystal phase, the liquid crystal phase has a length of mesogenic group from the perpendicular direction of the smectic layer during poling (dipole alignment) treatment and optical writing. Chiral smectic C (SmC) tilted in the axial direction ^* ) Are preferable, but chiral smectic I, chiral smectic F, chiral smectic J, chiral smectic K, chiral smectic H, and the like may be used. The temperature range of the liquid crystal phase at the time of poling (dipole alignment) processing and optical writing can take various ranges, but it is desirable that the temperature range is wide from the viewpoint of operability and convenience. Is particularly preferably in the range of 0 to 80 ° C.
[0048]
The phase sequence necessary for the compound constituting the organic dielectric layer is not limited as long as the liquid crystal phase exhibiting ferroelectricity is included in the liquid crystal phase sequence. When it is necessary to orient the mesogenic group parallel to the substrate using the oriented substrate, the isotropic phase, nematic or cholesteric phase, smectic A phase, and chiral smectic phase are followed in this order from the high temperature side. It is preferable that good orientation is obtained. The phase sequence may be followed in the order of chiral smectic I, chiral smectic F, or only chiral smectic I and chiral smectic F only. Further, other liquid crystal phases may appear on these low temperature sides, or may be transferred to a glass state. Examples of the liquid crystal phase on the low temperature side include chiral smectic J, chiral smectic K, chiral smectic H, and chiral smectic G.
[0049]
In order to homogeneously align the liquid crystalline group (mesogen group) in the side chain polymer liquid crystal of the present invention in the direction of the substrate, the organic dielectric layer on the substrate subjected to the alignment treatment is once heated to the isotropic phase. The orientation treatment is effective particularly for an organic dielectric layer made of a material that undergoes phase transition in the order of an isotropic phase, a nematic phase, and a smectic A phase. The slower the slow cooling rate, the higher the orientation of the mesogenic group, but a rate of 5 ° C./min or less is preferable.
[0050]
In the dielectric recording element of the present invention, if necessary, a thin insulating layer may be laminated between the conductive substrate and the organic dielectric layer, and an insulating protective film is provided on the surface of the dielectric layer. You can also.
[0051]
Since the organic dielectric layer constituting the dielectric recording element of the present invention has two functions of photoresponsiveness and ferroelectricity, the dielectric recording element of the present invention has the effect of being able to write light and having memory properties. Is played. By using a photochromic organic compound that imparts photoresponsiveness to the organic dielectric layer, it is possible to write an image on the organic dielectric layer at high speed using light.
[0052]
Usually, the direction of spontaneous polarization of a ferroelectric compound is determined by the direction of the applied electric field, but when a change in the quantity of electricity (D) is plotted against the applied voltage (E), a hysteresis curve is drawn. An example of this is shown in FIG. Such a hysteresis curve is peculiar to the ferroelectric compound, and the same applies to the dielectric recording element having the organic dielectric layer of the present invention.
[0053]
Next, the image recording method A of the present invention will be described.
[0054]
In the image recording method A of the present invention, an electric field is applied to the dielectric recording element of the present invention to align the dipoles of the organic dielectric layer in the same direction, and then a reverse electric field equal to or lower than the coercive electric field is applied. (1) Difference in surface charge density caused by difference in orientation direction of dipole in organic dielectric layer due to reversal of orientation direction of dipole induced by photochromism in light irradiated portion Or (2) difference in receptive potential caused by further applying a charge treatment to an organic dielectric layer having a difference in surface charge density caused by reversal of the orientation direction of dipoles induced by photochromism in the light-irradiated portion , To form a visible image by attaching electrostatic toner.
[0055]
As shown in FIG. 1, when light is not irradiated (corresponding to the thick hysteresis curve in FIG. 1), in the state where the direction of spontaneous polarization of the mesogenic group is aligned in the same direction (polling (dipole orientation) treatment), Even if the reverse electric field is applied up to a certain value (coercive electric field), the orientation change based on the reversal of the spontaneous polarization does not occur.
[0056]
However, when light is irradiated while applying an electric field of the same magnitude (corresponding to the thin line hysteresis curve in FIG. 1), the molecular structure of the photoclock compound changes reversibly, and the structural change is caused by the surrounding mesogens. Since the arrangement state of the group is also changed, the hysteresis curve of the ferroelectric compound can be actually changed by light irradiation.
[0057]
That is, by changing the value of the coercive electric field by irradiating light while applying a voltage, at the same time, by irradiating the light while applying an electric field having a reverse direction smaller than the coercive electric field when not irradiating light, The image forming method A of the present invention utilizes the phenomenon that the direction of spontaneous polarization of the dipoles in the dielectric layer is easily reversed and the surface charge density of the light-irradiated part and the unirradiated part changes accordingly.
[0058]
In this way, information can be recorded on the organic dielectric layer as a latent image by writing information to the organic dielectric layer using light. In order to make the recorded latent image a visible image, similarly to the method used in general electrophotography, corona charging and electrostatic toner development are performed after image exposure, or directly after image exposure. The electrostatic toner development may be performed, and when an image is formed on plain paper, film, etc., the electrostatic toner developed image may be transferred and fixed by a method similar to a general electrophotographic method.
[0059]
Images recorded on the organic dielectric layer can be stored as a latent image for a long period of time using the spontaneous polarization memory characteristic of organic dielectrics with ferroelectricity. The image can be transferred to plain paper by electrostatic toner development. Further, the latent image can be additionally written and erased at any time.
[0060]
In order to create a plurality of identical images in succession, images can be stored by the action of ferroelectric spontaneous polarization in a single optical writing process. Therefore, after image exposure, electrostatic toner development, transfer, and fixing are performed. It may be performed continuously. If the contrast, etc. decreases due to the transfer conditions or the surrounding environment, perform corona charging and roller charging as necessary, and then perform toner development, transfer, and fixing to create a continuous visible image. It can also be made. In addition, when electrostatic toner adheres to the surface of the organic dielectric layer as dirt due to physical adsorption or non-transfer during continuous copying, it is preferable to clean the surface using a blade or the like once. It may be performed for each of the steps, or may be performed for each of the steps several times.
[0061]
The poling (dipole orientation) treatment is a method for treating the organic dielectric layer so as to maximize the spontaneous polarization, and specifically, a method using corona charging or a method using a roller electrode can be mentioned. Poling (dipole orientation) treatment by corona charging can be performed using a corona charger using a normal corotron method or a scorotron method. Further, in the polling (dipole orientation) process by roller charging, a conductive rubber roller to which a high voltage is applied is brought into contact with the organic dielectric layer, for example, a resistance value of 10 ^Five -10 ⁹ A method of charging a conductive rubber roller of about Ωcm by applying a voltage of several hundred volts or more, a resistance value of 10 ^Three -10 ^Five There is a method in which a thin fiber wire of Ωcm is attached to the surface of the conductive roller in the form of a brush to improve contact, and a high voltage is applied to the conductive roller for charging. For both methods, a suitable method may be selected according to the system configuration of the apparatus. The time required for poling (dipole orientation) depends on the corona voltage, the applied voltage of the roller electrode, or the shape thereof, and can be appropriately set according to the system configuration of the apparatus, the method of using the apparatus, or the application.
[0062]
Image writing is performed by applying a photochromic reaction to the photochromic compound in the organic dielectric layer while applying a reverse electric field equal to or lower than the coercive electric field to the polling (dipole orientation) treated organic dielectric layer in the same manner as in the above charging method. This is done using light of a wavelength that can be caused.
[0063]
As a light source used for image writing, in addition to a mercury lamp, a xenon lamp, etc., a laser that emits light having a wavelength capable of causing a photochromic reaction, for example, a helium-cadmium laser, an argon laser, a helium-neon laser, a semiconductor laser, etc. Can be used as appropriate.
[0064]
As the image, a projection image formed by using an optical system such as a lens can be written on the surface of the organic dielectric layer that has been subjected to the poling (dipole orientation) treatment. An image can also be written by a method in which a photographic film or the like on which an image is recorded is placed on the surface of the organic dielectric layer and exposed. These writing exposure times are preferably set to optimum values according to the sensitivity and temperature of the organic dielectric layer.
[0065]
When writing image data on a television or computer, the electrical signal is converted using an external light modulator or light emitting element to change the light irradiation intensity, and the surface of the dielectric layer is scanned linearly with a polygon scanner or the like. The two-dimensional image can be written as a latent image by moving the dielectric layer. Furthermore, using a micro shutter array or an array in which light emitting elements are arranged in a straight line, image data from a television or computer can be converted to change the light irradiation intensity, and a two-dimensional image can be written by moving the dielectric layer. it can.
[0066]
When the exposure is performed while moving the dielectric layer, it is desirable to optimize the moving speed of the dielectric layer according to the intensity of the writing light, the sensitivity of the organic dielectric layer, and the temperature. In addition, when the moving speed of the dielectric layer is constant, optimum exposure can be performed by adjusting the intensity of writing light. The temperature of the organic dielectric layer at the time of writing need only be equal to or lower than the Curie point of the organic dielectric layer, and is set within a temperature range in which ferroelectricity is exhibited and the organic dielectric layer has a large spontaneous polarization. In this case, it is more preferable because it coincides with an appropriate temperature region for electrostatic toner development processing.
[0067]
After the image writing, the organic dielectric layer is developed using electrostatic powder toner or liquid toner at a temperature showing ferroelectricity, so that the toner adheres to the unexposed portion and the written image can be visualized. it can.
[0068]
The toner image developed on the surface of the organic dielectric layer can be electrostatically transferred to plain paper or film by superposing plain paper or film and then charging the back of the plain paper or film. .
[0069]
An organic dielectric having an image written as a latent image can be stored for a long period of time. The storage condition is preferably stored at a certain temperature or lower, and the storage temperature range is preferably below the melting point of the organic dielectric layer and below the upper limit Tc (Curie point) of the temperature exhibiting ferroelectricity. Moreover, although it can be stored in a bright room for a short period, it is desirable to use a dark room for long-term storage.
[0070]
The image forming method A of the present invention will be described in more detail with reference to FIG.
FIG. 2 (1) shows the first stage of the image recording method A of the present invention, in which an organic dielectric layer (3) is provided on a substrate (5) having a conductive layer (4). Spontaneous generation of a dipole (2) of a liquid crystalline group (mesogen group) exhibiting ferroelectricity in an organic dielectric layer by applying an electric field higher than the coercive electric field to the dielectric recording element using a corona charger (1) The state in which the direction of polarization is aligned with the electric field direction is schematically shown. After the state (1) in FIG. 2 is applied, as shown in FIG. 2 (2), when light having a wavelength causing photochromism is applied in a state where an electric field having a reverse direction below the coercive electric field is applied, FIG. As shown in (3), the structure of the functional group exhibiting photochromism changes, and along with this change, the alignment state of the liquid crystalline group (mesogenic group) surrounding the functional group exhibiting photochromism also changes. A latent image is formed by reversing the direction of spontaneous polarization of a liquid crystalline group (mesogen group) exhibiting ferroelectricity by the action of an electric field.
[0071]
That is, in the image forming method A of the present invention, the ferroelectricity is used to align the spontaneous polarization in the electric field direction by poling (dipole orientation) treatment, and then light is applied while applying a reverse electric field equal to or lower than the coercive electric field. As a result of writing and disordering in the orientation of the compound exhibiting ferroelectricity accompanying photoisomerization, the light-irradiated part shows a hysteresis curve different from that of the non-light-irradiated part. An image is formed. Since the surface charge density is different between the non-light-irradiated part where the spontaneous polarization formed in the dielectric layer is aligned in the electric field direction and the light-irradiated part aligned in the opposite direction, there is a difference in the attractive force of the electrostatic toner. Alternatively, when corona charging, roller charging or the like is performed in a state where the surface charge density is different, a difference occurs in the receptive potential, and development is performed using electrostatic toner, as shown in (4) of FIG. Is visualized as follows.
[0072]
As shown in FIG. 2 (5), the electrostatic toner adhering to the dielectric layer is transferred and fixed to paper or a film or the like in the same manner as in the usual electrophotographic method. As shown in (2), a printed matter is obtained. On the other hand, as shown in (6) of FIG. 2, the dielectric layer after electrostatic toner transfer is memorized (stored) as a latent image in the direction of the image recorded dipole. The surface is then cleaned, and the next printing, that is, the steps (4)-(5)-(6)-(7) in FIG. 2 are repeated to obtain a desired number of identical images continuously. .
[0073]
According to the image forming method A of the present invention, it is possible to write an image at the speed of photoisomerization, and the speed can be increased. Further, high-density writing at the molecular level and high resolution can be achieved. Further, the latent image once written is maintained even when the electric field is removed, has light and environmental stability, can be stored for a long period of time, and information can be additionally written, corrected, and erased at any time.
[0074]
Further, in the image forming method A of the present invention, development by a normal electrophotographic method can be performed, and a color image can be formed.
[0075]
In the image forming method A of the present invention, in order to erase information stored as a latent image, a method of irradiating light of a reaction in which the photochromic reaction returns to the original while applying an electric field higher than the coercive electric field opposite to that during recording Alternatively, there may be mentioned a method of applying an electric field higher than the opposite coercive electric field after irradiating light having a wavelength for returning the photochromic reaction.
[0076]
Next, the image forming method B of the present invention will be described.
[0077]
In the image forming method B of the present invention, after applying the electric field to the dielectric recording element of the present invention to align the dipoles of the organic dielectric layer in the same direction, the ferroelectricity of the dielectric layer is increased. Caused by optical writing at the indicated temperature Using the change in the receptive potential for the charging process resulting from the change in orientation of the dipole induced by photochromism of the writing part by light In this method, toner is attached to a written image to form an image.
[0078]
As shown in FIG. 1, when light is not irradiated (corresponding to the thick hysteresis curve in FIG. 1), the direction of spontaneous polarization of the ferroelectric liquid crystalline group (mesogen group) is aligned in the same direction ( In the poling (dipole orientation) process), even if a reverse electric field is applied up to a certain value (coercive electric field), the orientation change based on the reversal of the spontaneous polarization does not occur.
[0079]
However, when light is irradiated at a temperature at which the organic dielectric layer exhibits ferroelectricity, the molecular structure of the photoclock compound changes reversibly, and the structural change also changes the arrangement state of the mesogenic groups surrounding it. As a result, the alignment state of the dipole of the liquid crystalline group exhibiting ferroelectricity collapses, and the hysteresis curve does not show in the portion irradiated with light.
[0080]
That is, when the organic dielectric layer irradiates light at a temperature at which the ferroelectric layer exhibits ferroelectricity, the orientation state of the dipole of the liquid crystalline group exhibiting ferroelectricity collapses, and the electrical displacement peculiar to ferroelectricity becomes zero. The image forming method B of the present invention utilizes a phenomenon in which the surface charge density of the light irradiated portion and the non-irradiated portion changes.
[0081]
In this way, information can be recorded on the organic dielectric layer as a latent image by writing information to the organic dielectric layer using light.
[0082]
Further, an image recorded as a latent image on the organic dielectric layer by the image recording method B of the present invention can be stored for a long period of time.
[0083]
The method of making the recorded latent image in the image forming method B a visible image, the polling (dipole orientation) process, the irradiation method of the written image, the light source used for writing the image, and the storage condition of the recorded image are the image recording of the present invention. The same method, conditions or thing as the method A can be used.
[0084]
Hereinafter, the image forming method B of the present invention will be described in more detail with reference to FIG.
[0085]
FIG. 3 (1) shows the first stage of the image recording method B of the present invention, in which an organic dielectric layer (3) is provided on a substrate (5) having a conductive layer (4). Spontaneous generation of a dipole (2) of a liquid crystalline group (mesogen group) exhibiting ferroelectricity in an organic dielectric layer by applying an electric field higher than the coercive electric field to the dielectric recording element using a corona charger (1) The state in which the direction of polarization is aligned with the electric field direction is schematically shown. After the state of (1) in FIG. 3, as shown in (2) of FIG. 3, light having a wavelength that induces photochromism at a temperature at which the dielectric layer exhibits ferroelectricity in the organic dielectric layer. To do. The temperature of the organic dielectric layer at the time of writing may be equal to or lower than the Curie point of the organic dielectric layer or higher than the glass transition point. It is more preferable to set the temperature range in which the spontaneous polarization of the layer is maximized.
[0086]
After image writing, as shown in (3) of FIG. 3, the organic dielectric layer is developed with electrostatic powder toner or liquid toner at a temperature showing ferroelectricity, and the toner adheres to the unexposed area. Thus, the written image can be developed. If the visible image contrast is low, the electrostatic contrast can be improved and the visible image contrast improved by charging the entire organic dielectric layer below the coercive electric field by corona charging, if necessary. .
[0087]
As shown in (4) of FIG. 3, the toner image developed on the surface of the organic dielectric layer is formed by superposing plain paper or a film, and then charging the plain paper or the back of the film electrostatically. Electrostatic toner can be transferred to the film. The transferred image can be fixed by a method used in general electrophotography.
[0088]
(5) in FIG. 3 shows a state in which the residual toner and the physically adsorbed toner are removed from the surface of the organic dielectric, and the latent image can be stored in this state, or the toner in (3) in FIG. By returning to the developing process and repeating the transfer of the toner image, a large number of visible images can be formed.
[0089]
After storage, the stored latent image can be visualized starting from the toner development process of FIG. 1- (3).
[0090]
[Action]
In the image forming method A using the dielectric recording element of the present invention, a compound exhibiting ferroelectricity by poling (dipole orientation) treatment is oriented in the dipole electric field direction, and this orientation state is an electric displacement peculiar to ferroelectricity. By using the spontaneous polarization of the D-field E hysteresis characteristic as a memory property, and by writing an image with light while applying a reverse electric field below the coercive electric field to the organic dielectric layer in which the dipole is oriented in a certain direction, The reversal of the change in orientation of the dipole induced by photochromism occurs, and the change in the distribution of the surface charge density of the organic dielectric layer corresponding to the written image appears and can be recorded as a latent image. A difference in the attracting force of the electrostatic toner occurs depending on the direction of the orientation direction of the dipole, or a difference in the receptive potential due to the charging process occurs, and a visible image is obtained by developing the electrostatic toner. This can be transferred and fixed on paper or film by a usual electrophotographic method to obtain a copied image. Furthermore, this latent image has a memory property, so that a desired number of copied images can be obtained continuously by writing the image once, and since it is kept stable for a long time, it is stored as a latent image and copied when necessary. Images can also be obtained.
[0091]
In the image forming method B using the dielectric recording element of the present invention, the orientation of the dipole with respect to the electric field direction by the poling process is stored as spontaneous polarization, which is a ferroelectric property, and photochromic properties are obtained by irradiation with information light. As a result of the disorder of the dipole orientation associated with photoisomerization using the light, the light irradiated portion becomes a phase change or paraelectric property of the liquid crystal phase and a latent image is formed. As a result of a difference in the attractive force of the electrostatic toner between the ferroelectric portion and the other liquid crystal phase or the paraelectric portion, or when a charging process or the like is performed, a difference occurs in the receptive potential. A visible image is obtained by developing with electrostatic toner. The visualized toner image can be transferred to paper or film by a general electrophotographic method, and further, information can be stored as a latent image. A desired number of copy images can be obtained, and a latent image can be stored to obtain a copy image as needed.
[0092]
【Example】
Examples of the present invention will be shown below, and the present invention will be described more specifically. However, it is not limited to the embodiment of the present invention.
[0093]
(Synthesis Example 1)
(1-a) Synthesis of 4′-ethoxy-4-aminobiphenyl
22.2 g (92 mmol) of 4′-ethoxy-4-nitrobiphenyl was dissolved in 300 ml of ethyl acetate, and 1 g of 10% Pd / C was added. Next, hydrogen gas was introduced, and the reaction was carried out for about 1.5 hours until the consumption of hydrogen gas was stopped. After completion of the reaction, the catalyst was filtered off from the reaction solution, and the filtrate was concentrated to obtain 18.6 g of 4′-ethoxy-4-aminobiphenyl. (Yield 95%)
[0094]
(1-b) Synthesis of 4′-ethoxyphenyl-4-hydroxyazobenzene
In an ice-cooled mixture of 12.8 g (60 mmol) of the 4′-ethoxy-4-aminobiphenyl compound obtained in (1-a), 100 ml of dioxane, 13 ml of concentrated hydrochloric acid and 65 ml of water, 4.2 g of sodium nitrite (60 Mmol) and 10 ml of water were slowly added dropwise. After completion of the dropwise addition, stirring was further continued at 0 ° C. for 2 hours. After transferring the reaction mixture to the dropping funnel, the reaction mixture was added to a mixture of 5.7 g (60 mmol) phenol, 2.9 g (60 mmol) sodium hydroxide, 7.2 g sodium carbonate and 780 ml water. Added dropwise over 5 hours. After completion of the dropwise addition, the mixture was further stirred for 1.5 hours, and then the reaction mixture was neutralized with concentrated hydrochloric acid. Next, the reaction product was extracted with ethyl ether, the extract was concentrated, and the concentrate of the extract was purified using column chromatography to obtain 15.3 g of 4′-ethoxyphenyl-4-hydroxyazobenzene. Got. (Yield 80%)
[0095]
Synthesis of (1-c) {4- (6-hexyloxy) -4 ′-(4-ethoxybiphenyl) azobenzene} acrylate
A mixture of 12.7 g (40 mmol) of 4′-ethoxyphenyl-4-hydroxyazobenzene obtained in (1-b), 11 g (45 mmol) of 6-bromohexyl acrylate and 22 g (160 mmol) of potassium carbonate was added to acetone. Heated to reflux for 16 hours. After completion of the reaction, the reaction mixture is filtered, the filtrate is concentrated, and the filtrate concentrate is purified using column chromatography ({4- (6-hexyloxy) -4 '-(4-ethoxybiphenyl) azobenzene). } 9.4 g of acrylate was obtained. (Yield 50%)
[0096]
(1-d) {4- (6-Hexyloxy) -4 '-(4-ethoxybiphenyl) azobenzene obtained by synthesis (1-c) of a side chain polymer liquid crystal compound having a functional group exhibiting photochromism } 0.4 g (1.0 mmol) of acrylate, 2.4 mg of azobisisobutylnitrile and 10 ml of dry tetrahydrofuran were freeze degassed and reacted at 60 ° C. for 20 hours. The reaction product is purified using high performance liquid chromatography to obtain the formula
[0097]
[Chemical 8]

[0098]
As a result, 0.3 g of a side-chain polymer liquid crystal compound (polymerization degree: about 9000) having a functional group exhibiting photochromism composed of an azobenzene skeleton represented by the following formula was obtained.
[0099]
(Synthesis Example 2)
(2-a) Synthesis of 4- (4′-hydroxyphenyl) -benzoic acid-1-methylbutyl
In the presence of 2.1 ml of concentrated sulfuric acid, 21 g (0.1 mmol) of 4- (4′-hydroxyphenyl) benzoic acid and 44 g (0.4 mol) of (S)-(−)-1-methylbutanol were added in the presence of benzene. The mixture was heated to reflux in 160 ml for 25 hours. After completion of the reaction, the reaction mixture was concentrated and the reaction mixture concentrate was purified using column chromatography to obtain 26 g of 4- (4′-hydroxyphenyl) -benzoic acid-1-methylbutyl. (Yield 95%)
[0100]
(2-b) Synthesis of {4 ′-(6-hexyloxyphenyl) benzoic acid-1-methylbutyl} acrylate
4- (4′-hydroxyphenyl) -benzoic acid-1-methylbutyl 4.3 g (15 mmol) obtained in (2-a), acrylic acid 6-bromohexyl ester 4.1 g (17 mmol) and potassium carbonate 8 A mixture consisting of .3 g was heated to reflux in acetone for 16 hours. After completion of the reaction, the reaction mixture is filtered, the filtrate is concentrated, and the filtrate concentrate is purified using column chromatography, {4 '-(6-hexyloxyphenyl) benzoic acid-1-methylbutyl} acrylate 3 0.6 g was obtained. (Yield 55%)
[0101]
(2-c) Synthesis of a polymer liquid crystal compound having a ferroelectric group and a liquid crystal group (mesogen group) having a biphenyl skeleton in the side chain
It consists of 0.4 g (1.0 mmol) of {4 ′-(6-hexyloxyphenyl) benzoic acid-1-methylbutyl} acrylate obtained in (2-b), 2.4 g of azobisisobutylnitrile and 10 ml of dry tetrahydrofuran. The mixture was dried and degassed and then reacted at 60 ° C. for 20 hours. After completion of the reaction, the reaction product is purified using high performance liquid chromatography to obtain the formula
[0102]
[Chemical 9]

[0103]
As a result, 0.3 g of a polymer liquid crystal compound (polymerization degree: about 9600) having a ferroelectric group and a liquid crystalline group having a biphenyl skeleton (mesogen group) in the side chain was obtained.
[0104]
(Synthesis Example 3)
(3-a) Synthesis of 1-methylbutyl p-nitrobenzoate
16.7 g (0.1 mmol) of p-nitrobenzoic acid and 44.2 g (0.5 mol) of (S)-(−)-1-methylbutyl alcohol were added in 25 ml of benzene in the presence of 2 ml of concentrated sulfuric acid. Heated to reflux for hours. After completion of the reaction, the reaction solution was concentrated, and the concentrate of the reaction solution was purified using column chromatography to obtain 19.0 g of p-nitrobenzoic acid-1-methylbutyl. (Yield 80%)
[0105]
(3-b) Synthesis of 1-methylbutyl p-aminobenzoate
1-methylbutyl 1-methylbutyl p-nitrobenzoate obtained in (3-a) was dissolved in 300 ml of ethyl acetate, 1 g of 10% Pd / C was added to this solution, and hydrogen gas was introduced. The reaction was continued for about 5 hours until the consumption stopped. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated to obtain 13.7 g of p-aminobenzoic acid-1-methylbutyl. (Yield 85%)
[0106]
Synthesis of (3-c) 4′-hydroxy-4- (1-methylbutylcarboxy) azobenzene
13 g (60 mmol) of p-aminobenzoic acid-1-methylbutyl obtained in (3-b) was mixed with a mixture of 105 ml of dioxane, 13 ml of concentrated hydrochloric acid and 65 ml of water while cooling with ice, and a nitrous acid solution ( Sodium nitrite 4.2 g (60 mmol) / water 10 ml) was gradually added dropwise. After the addition was completed, the solution was stirred at 0 ° C. for about 2 hours, and then the solution was ice-cooled consisting of 5.9 g (60 mmol) of phenol, 2.4 g (60 mmol) of sodium hydroxide, 7 g of sodium carbonate and 78 ml of water. The mixture was added dropwise over about 1.5 hours. After completion of the dropwise addition, the reaction mixture was neutralized with hydrochloric acid / ice water, the reaction product was extracted with diethyl ether, the extract was concentrated, and the extract concentrate was purified using column chromatography. 14.7 g of -hydroxy-4- (1-methylbutylcarboxy) azobenzene was obtained. (Yield 81%)
[0107]
Synthesis of (3-d) {4 ′-(10-decyloxy) -4- (1-methylbutylcarboxy) azobenzene} acrylate
12 g (40 mmol) of 4′-hydroxy-4- (1-methylbutylcarboxy) azobenzene obtained in (3-c), 11 g (45 mmol) of acrylic acid 10-bromodecyl ester and 22 g (0.16 mol) of potassium carbonate ) Was heated to reflux in acetone for 16 hours. After completion of the reaction, the reaction mixture is filtered, the filtrate is concentrated, and the concentrate of the filtrate is purified using column chromatography {4 '-(10-decyloxy) -4- (1-methylbutylcarboxy) azobenzene. } 10 g of acrylate was obtained. (Yield 50%)
[0108]
(3-e) Synthesis of a polymeric liquid crystal compound having a photochromic functional group composed of an azobenzene skeleton and a ferroelectric liquid crystalline group (mesogen group) having an optically active group in the side chain
From 0.5 g (1 mmol) of {4 ′-(10-decyloxy) -4- (1-methylbutylcarboxy) azobenzene} acrylate obtained in (3-d), 2.5 mg of azobisisobutylnitrile and 10 ml of dry tetrahydrofuran. The resulting mixture was freeze degassed and then reacted at 70 ° C. for 20 hours. After completion of the reaction, the reaction solution is concentrated and the concentrate of the reaction solution is purified using high performance liquid chromatography.
[0109]
[Chemical Formula 10]

[0110]
0.25 g of a polymer liquid crystal compound (polymerization degree: about 9000) having a side chain of a ferroelectric liquid crystal group (mesogen group) having a photochromic functional group and an optically active group consisting of an azobenzene skeleton represented by It was.
[0111]
(Synthesis Example 4)
(4-a) Synthesis of 4′-hydroxy-4-ethoxyazobenzene
A mixture consisting of 8.0 g (60 mmol) of p-ethoxyaniline, 100 ml of dioxane, 13 ml of concentrated hydrochloric acid and 65 ml of water was ice-cooled, and this ice-cooled mixture was composed of 10 ml of water and 4.2 g (60 ml) of sodium nitrite. The solution was slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at 0 ° C. for 2 hours, and then the reaction mixture was mixed with a mixture of phenol 5.7 g (60 mmol), sodium hydroxide 2.9 g (60 mmol), sodium carbonate 7.2 g and water 780 ml. Over about 2 hours. After completion of the dropwise addition, the mixture was stirred at 0 ° C. for 1 hour, and then the reaction mixture was neutralized with hydrochloric acid. Ether is added to the neutralized reaction mixture, the reaction product is extracted with ethyl ether, the extract is concentrated, and the concentrate of the extract is purified using column chromatography, and 4′-hydroxy-4-ethoxy is obtained. 10.9 g of azobenzene was obtained. (Yield 75%)
[0112]
(4-b) Synthesis of {4 ′-(6-hexyloxy) -4-ethoxyazobenzene} acrylate
A mixture of 9.7 g (40 mmol) of 4′-hydroxy-4-ethoxyazobenzene obtained in (4-a), 11 g (45 mmol) of 6-bromohexyl acrylate and 22 g (160 mmol) of potassium carbonate was added to acetone. The mixture was heated at reflux for 20 hours. After completion of the reaction, the reaction mixture is filtered, the filtrate is concentrated, and the filtrate concentrate is purified using column chromatography.
[0113]
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[0114]
As a result, 6.6 g of an acrylic monomer having a liquid crystalline group (mesogenic group) having a functional group exhibiting photochromism composed of an azobenzene skeleton represented by the formula (1) was obtained. (Yield 45%)
[0115]
(Synthesis Example 5)
(5-a) Synthesis of {4 ′-(10-decyloxy) -4- (1-methylbutylcarboxy) biphenyl} acrylate
12.7 g (40 mmol) of 4- (4′-hydroxyphenyl) -benzoic acid-1-methylbutyl obtained in (2-a) of Synthesis Example 2 and 14.6 g (50 mmol) of acrylic acid 10-bromodecyl ester And a mixture of 22 g (160 mmol) of potassium carbonate and heated to reflux in acetone for 20 hours, the reaction mixture is filtered, the filtrate is concentrated, and the filtrate concentrate is purified using column chromatography.
[0116]
Embedded image

[0117]
As a result, 9.9 g of an acrylic monomer (5-1) having a ferroelectric group (mesogen group) having an optically active group and a biphenyl skeleton was obtained. (Yield 50%)
[0118]
(Synthesis Example 6)
An acrylic monomer having a liquid crystalline group (mesogen group) having a photochromic functional group composed of an azobenzene skeleton obtained in Synthesis Example 4 and a ferroelectric liquid crystalline group having an optically active group and a biphenyl skeleton obtained in Synthesis Example 5 2% azobisisobutylnitrile was added to a 20% by weight benzene solution of a 5:95 (molar ratio) mixture of acrylic monomers having a (mesogenic group) and vacuum degassed. Left to polymerize for 48 hours, formula
[0119]
Embedded image

[0120]
A side-chain polymer liquid crystal composed of a copolymer having a liquid crystalline group (mesogen group) having a photochromic functional group and a ferroelectric liquid crystalline group (mesogen group) composed of an azobenzene skeleton represented by Got.
[0121]
(Synthesis Example 7)
The acrylic monomer having a ferroelectric liquid crystalline group (mesogen group) having a photochromic functional group and an optically active group obtained from Synthesis Example 3 and the photochromism comprising the azobenzene skeleton obtained in Synthesis Example 4 After adding 2% azobisisobutylnitrile to a 20 wt% benzene solution of a 5:95 (molar ratio) mixture of acrylic monomers having a liquid crystal group (mesogenic group) having the functional group shown, vacuum degassing, The reaction vessel is sealed and left to polymerize at 60 ° C. for 48 hours.
[0122]
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[0123]
Side chain type ferroelectric polymer liquid crystal compound (polymerization degree: about 9200) which is a copolymer of a ferroelectric mesogenic group having an azobenzene skeleton exhibiting photochromism and a mesogenic group having an azobenzene skeleton exhibiting photochromism Got.
[0124]
(Synthesis Example 8)
(8-a) Synthesis of p-butylaniline
1 g of 10% Pd / C was added to a solution consisting of 16.5 g (92 mmol) of p-butylnitrobenzene and 300 ml of ethyl acetate, and the reaction was allowed to proceed for about 1.5 hours until the consumption of hydrogen gas ceased. After completion of the reaction, the catalyst was filtered off from the reaction solution, and the filtrate was concentrated to obtain 13 g of p-butylaniline. (Yield 95%)
[0125]
(8-b) Synthesis of 4′-butyl-4-hydroxyazobenzene
9 g (60 mmol) of p-butylaniline obtained in (8-a) was dissolved in an ice-cooled mixture consisting of 100 ml of dioxane, 13 ml of concentrated hydrochloric acid and 65 ml of water, and this solution was dissolved in 4.2 g of sodium nitrite (60 ml). Mmol) and 60 ml of water were gradually added dropwise at 0 ° C. After completion of the dropwise addition, the mixture was stirred at 0 ° C. for 2 hours, and then the reaction solution was ice-cooled consisting of 5.9 g (60 mmol) of phenol, 2.4 g (60 mmol) of sodium hydroxide, 7 g of sodium carbonate and 78 ml of water. The mixture was added dropwise over about 2 hours. After completion of the dropwise addition, the reaction mixture is neutralized with hydrochloric acid, the reaction product is extracted with diethyl ether, and the reaction product extract is purified using column chromatography, and 4'-butyl-4-hydroxyazobenzene. 12 g was obtained. (Yield 80%)
[0126]
(8-c) Synthesis of 4'-butyl-4-methoxyazobenzene
7.6 g (30 mmol) of 4′-butyl-4-hydroxyazobenzene obtained in (8-b) was dissolved in 100 ml of dimethylformamide, and 14 g (100 mmol) of potassium carbonate and 7.1 g of methyl iodide were dissolved in this solution. (50 mmol) was added and stirred at 70 ° C. for 1 hour. 5 g of methanol was added to the reaction mixture, and the mixture was further reacted at 70 ° C. for 8 hours. After completion of the reaction, the reaction mixture is filtered, the reaction product is extracted with ethyl ether, the extract is concentrated, and the extract is purified using column chromatography.
[0127]
Embedded image

[0128]
As a result, 2.7 g of a liquid crystal compound having a photochromic functional group composed of an azobenzene skeleton represented by the formula: (Yield 35%)
[0129]
(Synthesis Example 9)
(9-a) Synthesis of 4′-hydroxy-4- (benzoic acid-1-methylbutyl) azobenzene
13 g (60 mmol) of p-aminobenzoic acid-1-methylbutyl obtained in Synthesis Example 3 (3-b) was mixed with a mixture of 105 ml of dioxane, 13 ml of concentrated hydrochloric acid and 65 ml of water, and then ice-cooled. A solution consisting of 4.2 g of sodium nitrite and 10 ml of water was gradually added dropwise thereto. After completion of dropping, the mixture was stirred at 0 ° C. for 2 hours. The reaction mixture was transferred to a dropping funnel and the reaction mixture was placed in a mixture consisting of 10.2 g (60 mmol) of p-phenylphenol, 2.9 g (60 mmol) of sodium hydroxide, 7.2 g of sodium carbonate and 78 ml of water. It was dripped at about 2 hours over about 2 hours. After completion of dropping, the mixture was further stirred at 0 ° C. for 1.5 hours. After the reaction mixture was neutralized with hydrochloric acid, the reaction product was extracted with ethyl ether, the extract was concentrated, purified using column chromatography, and 4'-hydroxy-4-(-1-methylbutyl benzoate). ) 12.5 g of azobenzene was obtained. (Yield 70%)
[0130]
(9-b) Synthesis of {4 ′-(10-oxy-1-decene)}-4 ′-(1-methylbutyl benzoate) azobenzene
5.8 g (26 mmol) of 10-bromo-1-decene, 8.5 g (28 mmol) of 4′-hydroxy-4-(-1-methylbutylbenzoate) azobenzene obtained in (9-a) and potassium carbonate 4 0.0 g was heated to reflux in 100 ml of acetone for 20 hours. After completion of the reaction, the reaction mixture is filtered, the filtrate is concentrated, and the filtrate concentrate is purified using column chromatography, and {4 '-(10-oxy-1-decene)}-4'- 9.4 g of (1-methylbutyl benzoate) azobenzene was obtained. (Yield 77%)
[0131]
(9-c) A side chain exhibiting ferroelectricity in which a main chain composed of a siloxane bond and a ferroelectric liquid crystalline group (mesogenic group) having a functional group exhibiting photochromism composed of a ferroelectric group and an azobenzene skeleton are combined. Of Liquid Crystalline Polymer Liquid Crystal Compounds
{4 '-(10-Oxy-1-decene)}-4'-(1-methylbutylbenzoate) azobenzene obtained in (9-b) and 4.4 g (10 mmol) of polymethylhydrosiloxane were added. It melt | dissolved in 50 ml of toluene, 5 mg of chloroplatinic acid hexahydrate was added as a catalyst, and reaction was performed at 80 degreeC under argon atmosphere for 24 hours. After completion of the reaction, the reaction mixture was reprecipitated with methanol, and then the precipitate was dissolved in dichloromethane, the dichloromethane solution was dried and concentrated.
[0132]
Embedded image

A side chain type high in ferroelectricity in which a main chain composed of a siloxane bond represented by the above and a ferroelectric liquid crystalline group (mesogen group) having a functional group exhibiting photochromism composed of a ferroelectric group and an azobenzene skeleton are combined. 2.1 g of a molecular liquid crystal compound (degree of polymerization: about 9000) was obtained.
[0133]
(Synthesis Example 10)
Synthesis of (10-a) 4 ′-(10-oxy-1-decene) -4- (1-methylbutylcarboxy) biphenyl
8.5 g (30 mmol) of 4- (4′-hydroxyphenyl) -benzoic acid-1-methylbutyl obtained in (2-a) of Synthesis Example 2 7.7 g (35 mmol) of 10-bromo-1-decene And 4.6 g of potassium carbonate were refluxed in acetone for 20 hours. After completion of the reaction, the reaction mixture is filtered, the filtrate is concentrated, and the concentrate of the filtrate is purified using column chromatography, 4 ′-(10-oxy-1-decene) -4- (1-methyl). 8.8 g of (butylcarboxy) biphenyl were obtained. (Yield 70%)
[0134]
(10-b) Synthesis of a side-chain polymer liquid crystal compound exhibiting ferroelectricity in which a main chain composed of siloxane bonds and a ferroelectric liquid crystal group (mesogen group) having a ferroelectric group are bonded.
4.2 g (10 mmol) of 4 ′-(10-oxy-1-decene) -4- (1-methylbutylcarboxy) biphenyl obtained in (10-a) and 0.5 g of polymethylhydroxysiloxane were added to 50 ml of toluene. After dissolution, 5 mg of chloroplatinic acid hexahydrate was added as a catalyst, and the reaction was performed at 80 ° C. for 30 hours in an argon atmosphere. After completion of the reaction, the reaction mixture was reprecipitated with methanol, and then the precipitate was dissolved in dichloromethane, the dichloromethane solution was dried and concentrated.
[0135]
Embedded image

[0136]
A side chain type polymer liquid crystal compound exhibiting ferroelectricity in which a main chain composed of a siloxane bond represented by the above and a ferroelectric liquid crystal group having a ferroelectric group (mesogen group) are bonded (degree of polymerization: about 10,000) 2 0.0 g was obtained.
[0137]
(Synthesis Example 11)
{4 ′-(10-decyloxy) -4- (1-methylbutylcarboxy) biphenyl} acrylate 2.5 g (5 mmol) obtained in (5-a) of Synthesis Example 5 and (12 of Synthesis Example 12 described later) -C) 1- (2-methacryloxyethyl) -6'-nitro-3,3'-dimethylspiro- [2H-1-benzopyran-2,2'-indoline 0.1 g (0.25 mol) ) Was dissolved in 15 ml of dimethylformamide, 5 mg of azobisisobutylnitrile was added to the solution, vacuum degassed, and the mixture was reacted at 60 ° C. for 50 hours. After completion of the reaction, the reaction mixture was dropped into methanol and stirred well, and then the resulting precipitate was filtered off and dried to obtain a formula.
[0138]
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[0139]
Ferroelectric side-chain polymer liquid crystal compounds having a photochromic functional group consisting of a ferroelectric liquid crystal group (mesogen group) having an optically active group and a biphenyl skeleton in the side chain and a spiropyran skeleton (polymerization) The ratio of the number of ferroelectric mesogenic groups to the number of functional groups exhibiting photochromism was 95: 5) 1.2 g.
[0140]
(Synthesis Example 12)
(12-a) Synthesis of 1-hydroxyethyl-3,3-dimethyl-2-methyleneindoline
After reacting 22 g (138 mmol) of 2,3,3-trimethylindoline and 28 g (162 mmol) of 1-iodoethanol at 100 ° C. for 3 hours, 28 g of sodium hydroxide aqueous solution was added to the reaction mixture, and The reaction was performed for 6 hours. The reaction product was extracted with benzene, and then the extract was concentrated to obtain 30.5 g of 1-hydroxyethyl-3,3-dimethyl-2-methyleneindoline.
[0141]
(12-b) Synthesis of 1-hydroxyethyl-6′-nitro-3,3-dimethylspiro- [2H-1-benzopyran] -2,2′-indoline
28.0 g (138 mmol) of 1-hydroxyethyl-3,3-dimethyl-2-methyleneindoline obtained in (12-a) and 30.3 g (182 mmol) of 5-nitrosalicylaldehyde were added to 100 ml of ethyl alcohol in 100 ml. Heat at reflux at 2 ° C. for 2 hours. After completion of the reaction, the reaction mixture was filtered, purified by recrystallization and purified by 1-hydroxyethyl-6′-nitro-3,3-dimethylspiro- [2H-1-benzopyran] -2,2′-indoline 34 g. Got. (Yield 70%)
[0142]
Synthesis of (12-c) 1- (2-methacryloxyethyl) -6′-nitro-3,3′-dimethylspiro- [2H-1-benzopyran-2,2′-indoline
1-hydroxyethyl-6′-nitro-3,3-dimethylspiro- [2H-1-benzopyran] -2,2′-indoline obtained in (12-b) 12 g (34 mmol) and pyridine 16 ml (180 mmol) ) Was dissolved in 100 ml of anhydrous benzene, and 8.9 g (90 mmol) of methacrylic acid chloride was added dropwise to the solution over 1 hour while cooling the solution with ice water. After completion of the addition, the mixture was reacted at room temperature for 12 hours. . After completion of the reaction, the reaction mixture is dried and concentrated, and the reaction mixture is purified using column chromatography, and 1- (2-methacryloxyethyl) -6′-nitro-3,3′-dimethylspiro- [8.6 g of 2H-1-benzopyran-2,2′-indoline was obtained. (Yield 60%)
[0143]
(12-d) Ferroelectricity having a functional group exhibiting a photochromism comprising a ferroelectric liquid crystalline group (mesogenic group) having a photochromic functional group composed of an optically active group and an azobenzene skeleton in the side chain and a spiropyran skeleton. Of Side-Chain Polymer Liquid Crystal Compounds
Obtained in 1.5 g (3 mmol) and (12-c) of {4 ′-(10-decyloxy) -4- (1-methylbutylcarboxy) azobenzene} acrylate obtained in (3-d) of Synthesis Example 3 60 mg (0.15 mmol) of 1- (2-methacryloxyethyl) -6′-nitro-3,3′-dimethylspiro- [2H-1-benzopyran-2,2′-indoline was dissolved in 10 ml of dimethylformamide. Then, 4.7 mg of azobisisobutylnitrile was added to this solution, vacuum degassed, and reacted at 60 ° C. for 50 hours. After completion of the reaction, the reaction mixture was dropped into 500 ml of methanol and stirred sufficiently, and the resulting precipitate was collected by filtration and dried.
[0144]
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[0145]
A ferroelectric liquid crystal group (mesogenic group) having a photochromic functional group consisting of an optically active group and an azobenzene skeleton and a ferroelectric side having a photochromic functional group consisting of a spiropyran skeleton. A chain polymer liquid crystal compound (polymerization degree: about 9100, ratio of the number of mesogenic groups to photochromic substituents of 95: 5) was obtained.
[0146]
(Synthesis Example 13)
1-hydroxyethyl-6′-nitro-3,3-dimethylspiro- [2H-1-benzopyran] -2,2′-indoline 12 g (34 mmol) and pyridine obtained in Synthesis Example 12 (12-b) 16 ml (180 mmol) was dissolved in 100 ml of anhydrous benzene, and while cooling this solution with ice water, 9.5 g (90 mmol) of isobutyric chloride was added dropwise to this solution over 1 hour and reacted at room temperature for 15 hours. . After completion of the reaction, the reaction mixture is dried, concentrated and purified using column chromatography to obtain the formula
[0147]
Embedded image

[0148]
A spiropyran derivative exhibiting photochromism represented by
[0149]
Example 1
A side chain type polymer liquid crystal compound having a photochromic functional group composed of an azobenzene skeleton obtained in Synthesis Example 1 (degree of polymerization: about 9000) and a liquid crystal property having a ferroelectric group and a biphenyl skeleton obtained in Synthesis Example 2. 5 parts of a composition obtained by mixing a powder of a polymer liquid crystal compound having a group (mesogenic group) in the side chain (degree of polymerization: about 9600) at a weight ratio of 3:97 is completely added to 50 parts of chloroform solvent. After being dissolved, it was applied on a glass substrate with ITO so that the film thickness after drying was 2 μm, and then dried to form a dielectric layer, thereby obtaining a dielectric recording element.
[0150]
(Example 2)
5 parts of a polymer liquid crystal compound (polymerization degree: about 9000) having a side chain of a ferroelectric liquid crystal group (mesogen group) having a photochromic functional group and an optically active group, comprising the azobenzene skeleton obtained in Synthesis Example 3 Is dissolved in 100 parts of chloroform, applied onto an aluminum substrate by spin coating so that the film thickness after drying is 2 μm, and then dried to form an organic dielectric layer to obtain a dielectric recording element. It was.
[0151]
Example 3
In Example 2, instead of the polymer liquid crystal compound (polymerization degree: about 9000) obtained in Synthesis Example 3, a liquid crystalline group (mesogen group) having an azobenzene skeleton showing photochromism obtained in Synthesis Example 6 and a strong An organic dielectric layer is formed on an aluminum substrate in the same manner as in Example 2 except that a side-chain polymer liquid crystal having a liquid crystalline group (mesogen group) exhibiting dielectric properties is used. An element was obtained.
[0152]
(Example 4)
In Example 2, instead of the polymer liquid crystal compound obtained in Synthesis Example 3 (degree of polymerization: about 9000), the ferroelectric group obtained in Synthesis Example 2 and the liquid crystalline group having a biphenyl skeleton (mesogenic group) are located on the side. Composition 5 in which a polymer liquid crystal compound having a chain (polymerization degree: about 9600) and a liquid crystal compound having a photochromic functional group composed of the azobenzene skeleton obtained in Synthesis Example 8 were mixed at a weight ratio of 97: 3 An organic dielectric layer was formed on an aluminum substrate in the same manner as in Example 2 except that a solution in which 50 parts of chloroform was dissolved was used.
[0153]
Furthermore, a protective film-forming paint obtained by dissolving 5 parts of a polycarbonate resin ("PCZ" manufactured by Mitsubishi Yuka Co., Ltd.) in 500 parts of dichloromethane on this organic dielectric layer has a film thickness after drying of 0.3 μm. A dielectric recording element was obtained by coating with a spin coater so that the protective film was laminated.
[0154]
(Example 5)
In Example 2, instead of the polymer liquid crystal compound obtained in Synthesis Example 3 (degree of polymerization: about 9000), a photopolymer consisting of a main chain composed of the siloxane bond obtained in Synthesis Example 9, a ferroelectric group and an azobenzene skeleton. Photochromism obtained in Synthesis Example 8 and 95 parts of a side chain type polymer liquid crystal compound having a ferroelectricity (polymerization degree: about 9000) to which a ferroelectric liquid crystal group (mesogen group) having a chromic functional group is bonded. An organic dielectric layer was formed on an aluminum substrate in the same manner as in Example 2 except that a solution prepared by dissolving 5 parts of a mixture with 5 parts of an azobenzene derivative in 50 parts of chloroform was used.
[0155]
Further, a protective film having a thickness of 0.3 μm was laminated on the organic dielectric layer in the same manner as in Example 4 to obtain a dielectric recording element.
[0156]
(Example 6)
In Example 2, instead of the polymer liquid crystal compound obtained in Synthesis Example 3 (degree of polymerization: about 9000), a photopolymer consisting of a main chain composed of the siloxane bond obtained in Synthesis Example 9, a ferroelectric group and an azobenzene skeleton. 5 parts of a side chain type polymer liquid crystal compound having a ferroelectricity (polymerization degree: about 10,000) to which a ferroelectric liquid crystal group (mesogen group) having a chromic functional group is bonded and the siloxane bond obtained in Synthesis Example 10 And 95 parts of a powder of a side chain type polymer liquid crystal compound (polymerization degree: about 10,000) exhibiting ferroelectricity in which a ferroelectric liquid crystal group (mesogen group) having a ferroelectric group is bonded. A dielectric recording element was obtained by forming an organic dielectric layer on an aluminum substrate in the same manner as in Example 2 except that a solution obtained by dissolving 5 parts of the mixture in 50 parts of chloroform was used.
[0157]
(Example 7)
An N-methyl-2-pyrrolidone solution of polyamic acid (“PIX5000” manufactured by Hitachi Chemical Co., Ltd.) is applied onto the surface of the aluminum substrate by spin coating, and cured by heating to form a polyamide thin film of about 0.3 μm. The rubbing process was performed so that orientation could be obtained.
[0158]
In Example 2, instead of the polymer liquid crystal compound obtained in Synthesis Example 3 (degree of polymerization: about 9000), a photopolymer consisting of a main chain composed of the siloxane bond obtained in Synthesis Example 9, a ferroelectric group and an azobenzene skeleton. A solution obtained by dissolving 5 parts of a side chain type polymer liquid crystal compound (polymerization degree: about 9000) having ferroelectricity in which 50 parts of chloroform is bonded with a ferroelectric liquid crystal group (mesogen group) having a chromic functional group. A dielectric recording element was obtained by forming an organic dielectric layer in the same manner as in Example 2 except that the aluminum substrate subjected to the rubbing treatment was used as the aluminum substrate.
[0159]
(Example 8)
In Example 2, instead of the polymer liquid crystal compound obtained in Synthesis Example 3 (degree of polymerization: about 9000), a ferroelectric liquid crystal group having an optically active group and a biphenyl skeleton in the side chain obtained in Synthesis Example 11 ( A ferroelectric side chain polymer liquid crystal compound having a photochromic functional group comprising a mesogenic group) and a spiropyran skeleton (degree of polymerization of about 9300, the number of ferroelectric mesogenic groups and the number of functional groups exhibiting photochromism) A dielectric recording element was obtained by forming an organic dielectric layer on an aluminum substrate in the same manner as in Example 2, except that a solution in which 5 parts were dissolved in 50 parts of chloroform was used. .
[0160]
Example 9
In Example 2, instead of the polymer liquid crystal compound obtained in Synthesis Example 3 (degree of polymerization: about 9000), a functional group showing photochromism composed of an optically active group and an azobenzene skeleton was added to the side chain obtained in Synthesis Example 12. Ferroelectric side chain polymer liquid crystal compound having a functional group exhibiting photochromism composed of a ferroelectric liquid crystal group (mesogen group) and a spiropyran skeleton having a degree of polymerization of about 9100, the number of mesogen groups and photochromic substituents Ratio: 95: 5) An organic dielectric layer was formed on an aluminum substrate in the same manner as in Example 2 except that a solution obtained by dissolving 5 parts in 50 parts of chloroform was used to obtain a dielectric recording element. .
[0161]
(Example 10)
In Example 2, instead of the polymer liquid crystal compound obtained in Synthesis Example 3 (degree of polymerization: about 9000), the ferroelectric group obtained in Synthesis Example 2 and the liquid crystalline group having a biphenyl skeleton (mesogenic group) are located on the side. A composition 5 in which a polymer liquid crystal compound having a chain (polymerization degree: about 9500) and a liquid crystal compound having a photochromic functional group composed of an azobenzene skeleton obtained in Synthesis Example 8 are mixed at 97: 3 (weight ratio). An organic dielectric layer was formed on an aluminum substrate in the same manner as in Example 2 except that a solution in which 50 parts of chloroform was dissolved was used.
[0162]
Further, a protective film having a thickness of 0.3 μm was laminated on the organic dielectric layer in the same manner as in Example 4 to obtain a dielectric recording element.
[0163]
Example 11 [Example of Image Forming Method A of the Present Invention]
Each dielectric recording element obtained in Examples 1 to 10 was charged by a corona charger to which a corona voltage of +8 KV was applied, and a dielectric layer was subjected to poling (dipole orientation) treatment.
[0164]
Next, photoisomerization of the azobenzene derivative while charging (below the coercive electric field) with a corona charger that applied a corona voltage of -5 KV, which is the opposite polarity to that of the polling process, to the polled dielectric layer. Image writing was performed by irradiating ultraviolet light having a wavelength of 365 nm to form a latent image on the dielectric layer of each dielectric recording element.
[0165]
When the latent image formed on the dielectric layer was subjected to magnetic brush development using positive powder toner, the toner adhered to the non-exposed portion and visualized in any dielectric recording element. As a result of corona transfer and fixing to paper, a good image was obtained. Further, after the transfer, the residual toner was cleaned, and toner development, transfer, and fixing were repeated again. As a result, an image that was the same as the initial image was obtained for any of the dielectric recording elements.
[0166]
Further, after this latent image was stored in a dark place for 3 months, toner development, transfer, and fixing were performed again. As a result, an image similar to the initial image was obtained with any dielectric recording element. As a result, it was confirmed that it was stored stably for a long time.
[0167]
Furthermore, as a result of sufficiently irradiating the dielectric layer of each dielectric recording element with visible light (wavelength 440 nm) and performing the above-described poling (dipole orientation) process, a written image is obtained in any dielectric recording element. Completely erased.
[0168]
(Example 12)
In Example 1, the side chain type polymer liquid crystal compound having a photochromic functional group composed of the azobenzene skeleton obtained in Synthesis Example 1 (polymerization degree: about 9000) and the ferroelectric group and biphenyl obtained in Synthesis Example 2 were used. The mixing ratio of the polymer liquid crystal compound having a skeleton-containing liquid crystalline group (mesogen group) in the side chain (polymerization degree: about 9600) with the powder is 5:95 by weight, and 10 × instead of the glass substrate with ITO A dielectric recording element was obtained in the same manner as in Example 1 except that a 10 cm aluminum substrate was used.
[0169]
(Example 13)
In Example 2, a dielectric recording element was obtained in the same manner as in Example 2 except that a 10 × 10 cm aluminum substrate was used instead of the glass substrate with ITO.
[0170]
(Example 14)
In Example 3, a dielectric recording element was obtained in the same manner as in Example 3 except that a 10 × 10 cm aluminum substrate was used instead of the glass substrate with ITO.
[0171]
(Example 15)
In Example 4, the polymer liquid crystal compound having a ferroelectric group and a liquid crystalline group having a biphenyl skeleton (mesogen group) obtained in Synthesis Example 2 (mesogen group) in the side chain (polymerization degree: about 9600) and obtained in Synthesis Example 8 Example 4 except that the mixing ratio with a liquid crystal compound having a photochromic functional group composed of an azobenzene skeleton was 95: 5 by weight, and an aluminum substrate of 10 × 10 cm was used instead of the glass substrate with ITO. Similarly, a dielectric recording element was obtained.
[0172]
(Example 16)
In Example 5, a dielectric recording element was obtained in the same manner as Example 5 except that a 10 × 10 cm aluminum substrate was used instead of the glass substrate with ITO.
[0173]
(Example 17)
In Example 7, a dielectric recording element was obtained in the same manner as in Example 7 except that a 10 × 10 cm aluminum substrate was used instead of the glass substrate with ITO.
[0174]
(Example 18)
In Example 8, a dielectric recording element was obtained in the same manner as in Example 8 except that a 10 × 10 cm aluminum substrate was used instead of the glass substrate with ITO.
[0175]
(Example 19)
In Example 9, a dielectric recording element was obtained in the same manner as in Example 9 except that a 10 × 10 cm aluminum substrate was used instead of the glass substrate with ITO.
[0176]
(Example 20)
In Example 2, instead of the polymer liquid crystal compound obtained in Synthesis Example 3, the ferroelectric mesogenic group having the azobenzene skeleton exhibiting photochromism obtained in Synthesis Example 7 and the mesogen group of the azobenzene skeleton exhibiting photochromism are used. The same as Example 2 except that a side chain type ferroelectric polymer liquid crystal compound (polymerization degree: about 9200) as a copolymer was used, and a 10 × 10 cm aluminum substrate was used instead of the glass substrate with ITO. Thus, a dielectric recording element was obtained.
[0177]
(Example 21)
In Example 2, 95 parts of a polymer liquid crystal compound having a ferroelectric group and a liquid crystalline group having a biphenyl skeleton (mesogen group) obtained in Synthesis Example 3 (mesogen group) in the side chain (polymerization degree: about 9600) and Synthesis Example 13 A dielectric recording element was obtained in the same manner as in Example 2 except that a mixture with 5 parts of the obtained spiropyran derivative exhibiting photochromism was used and a 10 × 10 cm aluminum substrate was used instead of the glass substrate with ITO. It was.
[0178]
(Example 23) [Example of image forming method B of the present invention]
An aluminum electrode having the same size as the substrate was brought into close contact with the surface of the organic dielectric layer of each dielectric recording element obtained in Examples 12 to 22, and a 70V DC voltage was applied while heating to the temperature shown in Table 1. Then, the polling treatment of the organic dielectric layer was performed. After removing the aluminum electrode for poling, a test pattern was projected onto the surface of the organic dielectric layer of each dielectric recording element using a metal halide lamp and exposed. After the projection, the surface of the organic dielectric layer of each dielectric recording element was charged by negative corona discharge and developed with toner. As a result, the latent image written with the toner adhering to the unexposed area could be visualized. When this toner image was corona transferred to plain paper and fixed, good images were obtained in each dielectric recording element. Further, after removing the untransferred toner, corona charging was performed again, and toner development and corona transfer were performed. As a result, good images similar to the first time were obtained in all the dielectric recording elements. Further, it was confirmed that the same operation can be repeated for each dielectric recording element.
[0179]
The latent image formed on each dielectric recording element was stored in a dark place at room temperature for 3 months or more, and then developed with toner, transferred, and fixed again. As a result, each dielectric recording element was equivalent to the initial image. It was confirmed that a stable image was obtained and could be stably stored as a latent image for a long time.
[0180]
When each dielectric recording element on which the latent image was formed was sufficiently irradiated with visible light (440 nm) and a DC voltage of 70 V was applied again, it was confirmed that the latent image was completely erased.
[0181]
[Table 1]

[0182]
【The invention's effect】
The dielectric recording element of the present invention has an optically writable memory property by combining the organic dielectric layer with two functions, photoresponsiveness by photochromism and memory property by ferroelectricity.
[0183]
Further, according to the image forming method using the dielectric recording element of the present invention, a latent image can be formed by optical writing and visualized by toner development, and a copy image can be formed by corona transfer onto paper, film, etc. it can.
[0184]
In addition, the latent image formed by optical writing can be stored stably for a long period of time. Furthermore, writing can be performed at the speed of photoisomerization. As a result, high speed can be achieved, high density writing at the molecular level, and high resolution can be achieved.
[0185]
A latent image once written is stable to the environment, can be stored for a long period of time, and information can be written, corrected, and erased at any time.
[0186]
Further, in the formation of a large number of identical visible images, the toner development-transfer-fixing (cleaning) process can be performed once the image is written by using the memory property of the latent image to form the latent image. By repeating, it is possible to form a desired number of visible images.
[0187]
In addition, since development of a visible image of the present invention can be performed by a normal electrophotographic method, a color image can be formed.
[Brief description of the drawings]
FIG. 1 is a hysteresis curve chart showing the relationship between applied electric field (E) and electric displacement (D) in a dielectric recording element of the present invention.
FIG. 2 is a process explanatory diagram of an image forming method A using the dielectric recording element of the present invention.
[Explanation of symbols]
1 Corona charger
2 Dipole
3 Organic dielectric layer
4 Conductive layer
5 Substrate
6 Electrostatic toner
7 paper
FIG. 3 is a process explanatory diagram of an image forming method B using the dielectric recording element of the present invention.
[Explanation of symbols]
1 Corona charger
2 Dipole
3 Organic dielectric layer
4 Conductive layer
5 Substrate
6 In case of orientation change
7 Liquid crystal phase change
8 Electrostatic toner
9 paper

Claims (15)

A dielectric recording element comprising an organic dielectric layer exhibiting ferroelectricity and photochromism as an outermost layer on a substrate having a conductive layer.   The dielectric recording element according to claim 1, further comprising an alignment layer on a surface of the conductive layer on the organic dielectric layer side.   3. The dielectric recording element according to claim 1, wherein the organic dielectric layer exhibiting ferroelectricity and photochromism comprises a composition containing a compound exhibiting photochromism and a compound exhibiting ferroelectricity.   4. The dielectric recording element according to claim 3, wherein the compound exhibiting ferroelectricity is a side chain type polymer liquid crystal exhibiting ferroelectricity.   A compound exhibiting photochromism is (1) a polymer compound having a functional group exhibiting photochromism, and (2) a side chain type having a functional group exhibiting photochromism having a liquid crystalline group (mesogen group) at the terminal in the side chain. 5. The dielectric recording element according to claim 3, wherein the dielectric recording element is a compound selected from the group consisting of polymer liquid crystals.   The organic dielectric layer exhibiting ferroelectricity and photochromism is composed of a side chain type polymer liquid crystal having a substituent exhibiting ferroelectricity and a functional group exhibiting photochromism in the side chain. 3. The dielectric recording element according to 2.   A side-chain polymer liquid crystal having a substituent having ferroelectricity and a functional group having photochromism in the side chain is (1) a copolymerizable vinyl monomer having a liquid crystalline group (mesogen group) having ferroelectricity. And (2) a dielectric recording element according to claim 6, which is a copolymer comprising a copolymerizable monomer having a functional group exhibiting photochromism.   A side-chain polymer liquid crystal having a substituent having ferroelectricity and a functional group having photochromism in the side chain is (1) a copolymerizable vinyl monomer having a liquid crystalline group (mesogen group) having ferroelectricity. And (2) a dielectric recording element according to claim 6, which is a copolymer comprising a copolymerizable vinyl monomer having a liquid crystal group (mesogen group) at a terminal and a functional group exhibiting photochromism.   A side chain polymer in which an organic dielectric layer exhibiting ferroelectricity and photochromism has a substituent in which a liquid crystalline group exhibiting ferroelectricity (mesogenic group) and a functional group exhibiting photochromism are bonded to the side chain. 3. The dielectric recording element according to claim 1, comprising a liquid crystal.   A side-chain polymer liquid crystal in which an organic dielectric layer exhibiting ferroelectricity and photochromism has a liquid crystalline group (mesogen group) exhibiting ferroelectricity as a constituent element, which has a functional group exhibiting photochromism as a constituent element. The dielectric recording element according to claim 1, wherein the dielectric recording element comprises: The dielectric recording element according to claim 1, which is a dielectric recording element capable of forming a latent image by writing an image by light irradiation and visualizing the latent image by electrophotography.  The dielectric recording element according to claim 1, wherein an electric field is applied to align the dipoles of the organic dielectric layer in the same direction, and then a reverse electric field equal to or lower than the coercive electric field is applied. By irradiating light, (1) a difference in surface charge density caused by a difference in the orientation direction of the dipole in the organic dielectric layer accompanying the reversal of the orientation direction of the dipole induced by photochromism in the light irradiation portion, Or (2) The difference in the receptive potential generated by further subjecting the organic dielectric layer having a difference in surface charge density caused by the reversal of the orientation direction of the dipole induced by the photochromism of the light-irradiated portion to the charged portion. An image forming method comprising forming a visible image by adhering electrostatic toner.  13. The image forming method according to claim 12, wherein corona charging or roller charging is used as means for applying an electric field to the organic dielectric layer.  The ferroelectric recording element according to any one of claims 1 to 11, wherein an electric field is applied to align the dipoles of the organic dielectric layer in the same direction, and then the ferroelectric layer exhibits ferroelectricity. Using the change in receptive potential to the charging process caused by the change in orientation of the dipole induced by the photochromism of the writing part due to the light writing at the temperature, toner is deposited on the written image to form an image An image forming method.  15. The image forming method according to claim 14, wherein corona charging or roller charging is used as means for applying an electric field to the organic dielectric layer.

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