JP4158428B2 - Image forming material and image forming method using the same - Google Patents

Description

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第二の発明の画像形成層に、生保存性や画像保存性を改良する目的で添加されるかぶり防止剤は、以下に挙げる一般式で示されるハロゲン化合物が好ましい。
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【０１２２】
一般式中、Ｘ₁、Ｘ₂及びＸ₃は水素原子、ハロゲン原子、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、スルフォニル基、アリール基を表すが、少なくとも一つはハロゲン原子である。Ｙは−ＮＲ−Ｃ（＝Ｏ）−、−Ｃ（＝Ｏ）−、−Ｚ−Ｃ（＝Ｏ）−、−Ｚ−Ｓ（＝Ｏ）−、−ＳＯ−または−ＳＯ₂−を表し、ｎは０〜２の整数を、ｍは１〜１０を表す。なお、Ｒは水素原子またはアルキル基を表し、また、Ｒは後述するＱと環構造を形成していても良い。さらに、Ｚは酸素原子または硫黄原子を表す。
【０１２３】
一般式中、Ｑはアルキル基、アリール基またはヘテロ環基を表す。これらの基は置換基を有しても良い。一般式中のＱで表わされるアルキルとは、直鎖、分岐または環状のアルキル基であり、好ましくは炭素数１〜３０、より好ましくは１〜２０である。なお、Ｑで表わされるアルキル基は置換基を有していてもよく、このような置換基としてはマイクロカプセルする際に悪影響を及ぼさない置換基であればどのような基でも構わない。このような置換基としては、例えばハロゲン原子、アルケニル基、アルキニル基、アリール基、ヘテロ環基（Ｎ−置換の含窒素ヘテロ環基を含む、例えばモルホリノ基）、アルコキシカルボニル基、アリールオキシカルボニル基、カルバモイル基、イミノ基、Ｎ原子で置換したイミノ基、チオカルボニル基、カルバゾイル基、シアノ基、チオカルバモイル基、アリールオキシ基、ヘテロ環オキシ基、アシルオキシ基、（アルコキシもしくはアリールオキシ）カルボニルオキシ基、スルホニルオキシ基、アシルアミド基、スルホンアミド基、ウレイド基、チオウレイド基、イミド基、（アルコキシもしくはアリールオキシ）カルボニルアミノ基、スルファモイルアミノ基、セミカルバジド基、チオセミカルバジド基、（アルキルもしくはアリール）スルホニルウレイド基、ニトロ基、（アルキルまたはアリール）スルホニル基、スルファモイル基、リン酸アミドもしくはリン酸エステル構造を含む基、シリル基等が挙げられる。これら置換基は、これら置換基でさらに置換されていてもよい。
【０１２４】
また、一般式中のＱで表わされるアリール基は単環または縮合環のアリール基であり、好ましくは炭素数６〜２４、より好ましくは６〜２０である。このような単環または縮合環のアリール基としては、例えばフェニル、ナフチル、アントラセニル、フェナントレニル、ナフタセニル、トリフェニレニル等を挙げることができる。なお、Ｑで表わされるアリール基は画像形成に悪影響を及ぼさない置換基を有していてもよく、このような置換基としてはハロゲン原子、アルキル基、アルケニル基、アルキニル基、アリール基、ヘテロ環基（Ｎ−置換の含窒素ヘテロ環基を含む、例えばモルホリノ基）、アルコキシカルボニル基、アリールオキシカルボニル基、カルバモイル基、イミノ基、Ｎ原子で置換したイミノ基、チオカルボニル基、カルバゾイル基、シアノ基、チオカルバモイル基、アリールオキシ基、ヘテロ環オキシ基、アシルオキシ基、（アルコキシもしくはアリールオキシ）カルボニルオキシ基、スルホニルオキシ基、アシルアミド基、スルホンアミド基、ウレイド基、チオウレイド基、イミド基、（アルコキシもしくはアリールオキシ）カルボニルアミノ基、スルファモイルアミノ基、セミカルバジド基、チオセミカルバジド基、（アルキルもしくはアリール）スルホニルウレイド基、ニトロ基、（アルキルまたはアリール）スルホニル基、スルファモイル基、リン酸アミドもしくはリン酸エステル構造を含む基、シリル基等が挙げられる。これら置換基は、これら置換基でさらに置換されていてもよい。
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さらに、一般式中のＱで表わされるヘテロ環基は、窒素、酸素、硫黄、セレンまたはテルルの少なくとも一つの原子を含む４〜８員の飽和もしくは不飽和のヘテロ環基であり、これらは単環であっても良いし、更に他の環と縮合環を形成してもよい。このようなヘテロ環基として、好ましくは縮合環を有していてもよい５ないし６員の不飽和ヘテロ環基である。このような縮合環を有していてもよいヘテロ環基におけるヘテロ環として好ましくは、イミダゾール、ピラゾール、ピリジン、ピリミジン、ピラジン、ピリダジン、トリアゾール、トリアジン、インドール、インダゾール、プリン、チアジアゾール、オキサジアゾール、キノリン、フタラジン、ナフチリジン、キノキサリン、キナゾリン、シンノリン、プテリジン、アクリジン、フェナントロリン、フェナジン、テトラゾール、チアゾール、オキサゾール、ベンズイミダゾール、ベンズオキサゾール、ベンズチアゾール、インドレニン、テトラザインデンであり、より好ましくはイミダゾール、ピリジン、ピリミジン、ピラジン、ピリダジン、トリアゾール、トリアジン、チアジアゾール、オキサジアゾール、キノリン、フタラジン、ナフチリジン、キノキサリン、キナゾリン、シンノリン、テトラゾール、チアゾール、オキサゾール、ベンズイミダゾール、ベンズオキサゾール、ベンズチアゾール、テトラザインデン等を挙げることができる。なお、Ｑで表わされるヘテロ環基は画像形成に悪影響を及ぼさない置換基を有していてもよく、このような置換基としては前述のアリール基の置換基と同様の基を挙げることができる。
【０１２６】
上記一般式で表されるハロゲン化合物としては、例えば下記に例示する化合物が挙げられる。
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さらに、米国特許第３，８７４，９４６号、同第４，７５６，９９９号、同第５，０２８，５２３号、同第５，３４０，７１２号、同第５，３６９，０００号、同第５，４６４，７３７号、欧州特許第６００，５８７号、同第６０５，９８１号、同第６３１，１７６号、特公昭５４−４４２１２号、特公昭５１−９６９４号、特開昭５０−１３７１２６号公報、同５０−８９０２０号、同５０−１１９６２４号、同５５−１４０８３３号、同５９−５７２３４号、特開平７−２７８１号、同７−５６２１号、同９−９０５５０号、同９−１６０１６４号、同９−１６０１６７号、同９−２４４１７７号、同９−２４４１７８号、同９−２５８３６７号、同９−２６５１５０号、同９−２８８３２８号、同９−３１９０２２号、同１０−１９７９８８号、同１０−１９７９８９号、同１１−２４２３０４号、特開２０００−２９６３、同２０００−１１２０７０、同２０００−２８４４１２、同２０００−２８４４１０、同２００１−３３９１１等に開示されている化合物も本発明の目的を阻害しなければ適時選択して用いることができ、これらの化合物は単独、あるいは２種以上併用して用いることができる。
【０１３４】
かぶり防止剤として、前述のハロゲン化合物に加えて、特開昭５８−１０７５３４号、特開平８−６２０３号、特開２０００−１９９９３６、同２０００−３２１７１１、同２００２−２３３０４、同２００２−４９１２１等に記載されているポリカルボン酸あるいはその無水物や、特開昭５１−７８２２７号、同５３−２０９２３号、同５５−１４０８３３号、特開平７−２０９７９７号、同８−３１４０５９号、同９−４３７６０号、特開２０００−２８４４００、同２０００−２８４４１３等に記載されているチオスルホン酸あるいはその塩、またはその誘導体、さらには米国特許６，０８３，６８１号、特開２００２−６２６１６、同２００２−６２６１７、同２００２−９０９３５等に記載されているカルボン酸やスルフィン酸あるいはその塩など、本発明の目的を阻害しない範囲で添加しても良い。
【０１３５】
現像後の銀色調を改良する目的で添加される色調剤としては、例えば、イミド類（例えば、フタルイミド）；環状イミド類、ピラゾリン−５−オン類、及びキナゾリノン（例えば、スクシンイミド、３−フェニル−２−ピラゾリン−５−オン、１−フェニルウラゾール、キナゾリン及び２，４−チアゾリジンジオン）；ナフタールイミド類（例えば、Ｎ−ヒドロキシ−１，８−ナフタールイミド）；コバルト錯体（例えば、コバルトのヘキサミントリフルオロアセテート）、メルカプタン類（例えば、３−メルカプト−１，２，４−トリアゾール）；Ｎ−（アミノメチル）アリールジカルボキシイミド類（例えば、Ｎ−（ジメチルアミノメチル）フタルイミド）；ブロックされたピラゾール類、イソチウロニウム（ｉｓｏｔｈｉｕｒｏｎｉｕｍ）誘導体及びある種の光漂白剤の組み合わせ（例えば、Ｎ，Ｎ′−ヘキサメチレン（１−カルバモイル−３，５−ジメチルピラゾール）、１，８−（３，６−ジオキサオクタン）ビス（イソチウロニウムトリフルオロアセテート）、及び２−（トリブロモメチルスルホニル）ベンゾチアゾールの組み合わせ）；メロシアニン染料（例えば、３−エチル−５−（（３−エチル−２−ベンゾチアゾリニリデン（ベンゾチアゾリニリデン））−１−メチルエチリデン）−２−チオ−２，４−オキサゾリジンジオン）；フタラジノン、フタラジノン誘導体またはこれらの誘導体の金属塩（例えば、４−（１−ナフチル）フタラジノン、６−クロロフタラジノン、５，７−ジメチルオキシフタラジノン、及び２，３−ジヒドロ−１，４−フタラジンジオン）；フタラジノンとスルフィン酸誘導体の組み合わせ（例えば、６−クロロフタラジノン＋ベンゼンスルフィン酸ナトリウムまたは８−メチルフタラジノン＋ｐ−トリスルホン酸ナトリウム）；フタラジン＋フタル酸の組み合わせ；フタラジン（フタラジンの付加物を含む）とマレイン酸無水物、及びフタル酸、２，３−ナフタレンジカルボン酸またはｏ−フェニレン酸誘導体及びその無水物（例えば、フタル酸、４−メチルフタル酸、４−ニトロフタル酸及びテトラクロロフタル酸無水物）から選択される少なくとも１つの化合物との組み合わせ；キナゾリンジオン類、ベンズオキサジン、ナルトキサジン誘導体；ベンズオキサジン−２，４−ジオン類（例えば、１，３−ベンズオキサジン−２，４−ジオン）；ピリミジン類及び不斉−トリアジン類（例えば、２，４−ジヒドロキシピリミジン）、及びテトラアザペンタレン誘導体（例えば、３，６−ジメルカプト−１，４−ジフェニル−１Ｈ，４Ｈ−２，３ａ，５，６ａ−テトラアザペンタレン）。好ましい色調剤としては、フタラゾン、フタラジンが挙げられる。
【０１３６】
なお、色調剤は、本発明の目的を阻害しないのであれば後述する保護層に添加しても良い。
【０１３７】
また、増感色素としては、後述の画像形成方法で詳述する走査露光に用いるレーザ光源の発振波長に対して吸収を有するものであれば特に制限なく用いることができる。
【０１３８】
その中で、レーザ光源としては、波長が７００〜１２００ｎｍの半導体レーザを用いるのメンテナンスや光源の大きさからが好ましく、このような波長域に吸収極大波長を有する増感色素としては、例えばシアニン色素、ローダシアニン色素、オキソノール色素、カルボシアニン色素、ジカルボシアニン色素、トリカルボシアニン色素、テトラカルボシアニン色素、ペンタカルボシアニン色素、スチリル色素、ピリリウム色素、金属フタロシアニンや金属ポルフィリン等の含金色素等が挙げられ、具体的には、Ｃｈｅｍ．Ｒｅｖ．９２，１１９７（１９９２）等に記載の色素、特開昭４８−３５２７号、同４９−１１１２１号、同５８−１４５９３６号、同５９−１９１０３２号、同５９−１９２２４２号、同６０−８０８４１号、同６２−２８４３４３号、特開平２−１０５１３５号、同３−６７２４２号、同３−１６３４４０号、同４−１８２６３９号、同５−３４１４３２号、同７−１３２９５号、同１１−３０８３３号、同１１−３５２６２８号、特開２０００−９５９５８、同２０００−９８５２４、同２０００−１２２２０７、同２０００−１６９７４１、同２０００−１７１９３８、同２０００−２７３３２９、同２０００−３２１７０４、同２００１−６４５２７、同２００１−８３６５５、特表平９−５１００２２号等に記載された色素を適時選択して用いることができる。
【０１３９】
また、強色増感剤としてはＲＤ１７６４３、特公平９−２５５００号、同４３−４９３３号、特開昭５９−１９０３２号、同５９−１９２２４２号、特開平５−３４１４３２号等に記載されている化合物を適時選択して用いることができ、本発明では、下記一般式（３）で表される複素芳香族メルカプト化合物、実質的に前記のメルカプト化合物を生成する一般式（４）で表されるジスルフィド化合物を用いることができる。
【０１４０】
一般式（３） Ａｒ−ＳＭ
一般式（４） Ａｒ−Ｓ−Ｓ−Ａｒ
一般式（３）において、Ｍは水素原子又はアルカリ金属原子を表し、Ａｒは１個以上の窒素、硫黄、酸素、セレニウムもしくはテルリウム原子を有する複素芳香環又は縮合複素芳香環を表す。複素芳香環は、好ましくは、ベンズイミダゾール、ナフトイミダゾール、ベンゾチアゾール、ナフトチアゾール、ベンズオキサゾール、ナフトオキサゾール、ベンゾセレナゾール、ベンゾテルラゾール、イミダゾール、オキサゾール、ピラゾール、トリアゾール、トリアジン、ピリミジン、ピリダジン、ピラジン、ピリジン、プリン、キノリン又はキナゾリンである。また、一般式（４）中のＡｒは上記一般式（Ｍ）の場合と同義である。
【０１４１】
上記の複素芳香環は、例えば、ハロゲン原子（例えば、Ｃｌ、Ｂｒ、Ｉ）、ヒドロキシ基、アミノ基、カルボキシル基、アルキル基（例えば、１個以上の炭素原子、好ましくは、１〜４個の炭素原子を有するもの）及びアルコキシ基（例えば、１個以上の炭素原子、好ましくは、１〜４個の炭素原子を有するもの）からなる群から選ばれる置換基を有することができる。
【０１４２】
本発明において、高感度にするためには強色増感剤として下記に示すチウロニウム化合物を用いることがより好ましい。
【０１４３】
【化１４】

【０１４４】
【化１５】

【０１４５】
さらに、特開２００１−３３０９１８等に記載されたチウロニウム化合物も本発明の目的の範囲内で、適時選択して用いることができる。
【０１４６】
強色増感剤は、有機銀塩及びハロゲン化銀粒子を含む画像形成層中に銀１モル当たり０．００１〜１．０モルの範囲で用いるのが好ましく、特に銀１モル当たり０．０１〜０．５モルの範囲にするのが好ましい。
【０１４７】
第二の形態の画像形成層には、さらにヘテロ原子を含む大環状化合物を含有させることができ、ヘテロ原子として窒素原子、酸素原子、硫黄原子及びセレン原子の少なくとも１種を含む９員環以上の大環状化合物が好ましく、１２〜２４員環がより好ましい。このような化合物としては、クラウンエーテルで下記のＰｅｄｅｒｓｏｎが１９６７年に合成し、その特異な報告以来、数多く合成されているものである。これらの化合物は、Ｃ．Ｊ．Ｐｅｄｅｒｓｏｎ，Ｊｏｕｒｎａｌｏｆ Ａｍｅｒｉｃａｎ ｃｈｅｍｉｃａｌ ｓｏｃｉｅｔｙ ｖｏｌ，８６（２４９５），７０１７〜７０３６（１９６７），Ｇ．Ｗ．Ｇｏｋｅｌ，Ｓ．Ｈ，Ｋｏｒｚｅｎｉｏｗｓｋｉ，”Ｍａｃｒｏｃｙｃｌｉｃ ｐｏｌｙｅｔｈｒ ｓｙｎｔｈｅｓｉｓ”，Ｓｐｒｉｎｇｅｒ−Ｖｅｒｇａｌ，（１９８２）、特開２０００−３４７３４３等に詳細に記載されている。
【０１４８】
さらに、第二の発明の画像形成層には、上述した添加剤以外に例えば、界面活性剤、酸化防止剤、安定化剤、可塑剤、紫外線吸収剤、被覆助剤等を用いても良い。これらの添加剤及はＲＤ Ｉｔｅｍ１７０２９（１９７８年６月ｐ．９〜１５）に記載されている化合物を、本発明の目的を阻害しない範囲で適時選択して用いることができる。
【０１４９】
第二の発明において、画像形成層は単層でも良く、組成が同一あるいは異なるの複数層の層で構成しても良い。なお、画像形成層の膜厚は通常５〜３０μｍである。
【０１５０】
第二の発明の画像形成材料に用いられる保護層は、第一の形態で述べた保護層と同様にして形成することができ、さらに必要に応じて設置されるバッキング層も、第一の形態で述べたバッキング層と同様にして形成することができる。なお、バッキング層には、さらに、ハレーションを防止する目的で、後述の画像形成方法で詳述するレーザの、発振波長域に吸収を有する化合物をハレーション防止剤として含有させても良い。
【０１５１】
なお、保護層の厚みは通常１．０〜５．０μｍであり、バッキング層の厚みは、通常は０．５〜１０μｍ程度である。
【０１５２】
また、本発明の第二の発明で設置される、画像形成層、保護層は、及び必要に応じて設置されるバッキング層は、第一の形態で述べた方法で塗工液として調製することができ、さらに同様の方法で塗布することにより画像形成材料を形成することができる。
【０１５３】
次に、本発明の第一の発明の画像形成材料を用いた画像形成方法について説明する。
【０１５４】
本発明の画像形成方法では、第一の発明の画像形成材料を保護層側から像様に加熱して銀画像を形成させることを特徴としている。
【０１５５】
上記画像形成方法において、像様に加熱する手段としては、近赤外から赤外領域のレーザやサーマルヘッドを用いることができるが、この中で、装置のコンパクト性やメンテナンス性などの面からサーマルヘッドを用いるのが好ましい。
【０１５６】
このようなサーマルヘッドとしては、古くからラベルプリンターなどの溶融転写方式、感熱紙などの感熱発色方式、染料転写などの昇華転写方式など広く利用されており、本画像形成方法においてはシリアルタイプのものでもラインタイプのものでも良いが、画像形成材料の幅手方向全てをカバーできるように発熱体を配置したラインタイプのものが好ましい。
【０１５７】
なお、ライン状のサーマルヘッドは、通常広く使用されている主走査方向に対して発熱体を一列に配置したものでも良いし、特開平６−９１９１２号、同８−２５８３０５号、同９−１９３４３８号、特開２０００−１９８２２９等に記載されているように発熱体を千鳥状に配置したもの、あるいは特開平１０−３１５５１８号、特開２００１−１８００２６等に記載されているように二列に配置したダブルライン、あるいは特開２００２−４６２９７等に記載されているように予備加熱部を有するような配置であっても良い。また、発熱体個々の形状としては通常広く使用されている四角形の形状でも良いし、特開平７−７６１１７号等に記載されているように台形状や櫛型階段状の物であっても良い。また発熱体一つのパルス印加時の表面温度分布においても全体に均一であっても良いし、特開昭６０−５８８７７号、同６１−２３０９５９号等に記載されているように発熱体の中央部が高温になるような形態であっても良い。
【０１５８】
サーマルヘッドのグレーズ形状としては全面グレーズ、部分グレーズあるいはその他の公知の形状であっても良い。また、発熱体の記録密度としては入力される画像により一概に規定できないが、通常１５０〜６００ドット／インチであり、好ましくは２００〜４００ドット／インチである。また画像の階調は入力パルスの周期、印加時間、印加電圧、デューティーサイクル等を変更することで必要な階調数を得ることができる。なお、サーマルヘッド表面の温度はエネルギー印加時に通常３００〜４００℃の範囲内にあり、プラテンロールとサーマルヘッド間の圧力（プラテン圧）は、熱を均一に伝えるために１〜６Ｎ／ｃｍ²にするのが好ましい。
【０１５９】
次に、本発明の第二の発明の画像形成材料を用いた、画像形成方法について説明する。
【０１６０】
本発明の画像形成方法では、第二の発明の画像形成材料を保護層側から像様に露光した後に全面加熱（以後熱現像と称す）して銀画像を形成することを特徴としている。
【０１６１】
第二の発明の画像形成材料は画像形成層に感光性のハロゲン化銀を含有することで、画像形成層を感光性にすることができ、第一の発明の画像形成材料の性能に加えて、さらにレーザ等のデジタル露光書き込みが可能となる。
【０１６２】
上記画像形成方法において、像様に露光する手段としては、走査露光可能なレーザを光源として用いるのが好ましく、このような走査露光に用いるレーザとしては、一般によく知られている、ルビーレーザ、ＹＡＧレーザ、ガラスレーザ等の固体レーザ；Ｈｅ−Ｎｅレーザ、Ａｒイオンレーザ、Ｋｒイオンレーザ、ＣＯ₂レーザ、ＣＯレーザ、Ｈｅ−Ｃｄレーザ、Ｎ₂レーザ、エキシマーレーザ等の気体レーザ；ＩｎＧａＰレーザ、ＡｌＧａＡｓレーザ、ＧａＡｓＰレーザ、ＩｎＧａＡｓレーザ、ＩｎＡｓＰレーザ、ＣｄＳｎＰ₂レーザ、ＧａＳｂレーザ等の半導体レーザ；化学レーザ、色素レーザ等を用途に併せて適時選択して使用できるが、これらの中でもメンテナンスや光源の大きさの問題から、波長が７００〜１２００ｎｍの半導体レーザを用いるのが好ましい。
【０１６３】
なお、画像形成材料に走査されるときの該材料露光面でのビームスポット径は、レーザ・イメージャやレーザ・イメージセッタで使用されるレーザにおいて、一般に短軸径として４〜７５μｍ、長軸径として４〜１００μｍの範囲であり、レーザ光走査速度は画像形成材料固有のレーザ発振波長における感度とレーザパワーによって、画像形成材料毎に最適な値に設定することができる。
【０１６４】
さらに、上述の走査露光するレーザにおいて、露光面とレーザ光のなす角度、レーザの波長、使用するレーザの数を調整することで、本発明の画像形成材料から得られる画像として干渉縞のない鮮明な画像を得ることができる。なお、該手段は、それらを単独で行っても良いし、二種以上の態様を組み合わせても良い。
【０１６５】
上述の第一の態様としては、画像形成材料の露光面とレーザ光のなす角が実質的に垂直になることがないレーザ光を用いて、走査露光により画像を形成することを特徴としている。このように、入射角を垂直からずらすことにより、層間界面での反射光が発生した場合においても、画像形成層に達する光路差が大きくなることから、レーザ光の光路での散乱や減衰が生じて干渉縞が発生しにくくなる。なお、ここで、「実質的に垂直になることがない」とはレーザ走査中に最も垂直に近い角度として主走査方向と副走査方向とも９０度ではないことを表し、好ましくは主走査方向と副走査方向の少なくともいずれかが５５〜８８度、さらには６０〜８６度にするのが好ましい。
【０１６６】
また、第二の態様としては、露光波長が単一でない縦マルチレーザを用いて、走査露光により画像を形成することを特徴としている。このような、波長に幅を有する縦マルチレーザ光で走査すると縦単一モードの走査レーザ光に比べ、干渉縞の発生が低減される。なお、ここで言う縦マルチとは、露光波長が単一でないことを意味し、通常露光波長の分布が５ｎｍ以上、好ましくは１０ｎｍ以上になるとよい。露光波長の分布の上限には特に制限はないが、通常６０ｎｍ程度である。
【０１６７】
さらに、第三の態様としては、２本以上のレーザを用いて、走査露光により画像を形成することを特徴としている。このような複数のレーザを利用した画像形成方法としては、高解像度化、高速化の要求から１回の走査で複数ラインずつ画像を書き込むレーザプリンタやデジタル複写機の画像書込み手段で使用されている技術であり、例えば特開昭６０−１６６９１６号等により知られている。これは、光源ユニットから放射されたレーザ光をポリゴンミラーで偏向走査し、ｆθレンズ等を介して感光体上に結像する方法であり、レーザイメージャなどと原理的に同じレーザ走査光学装置である。
【０１６８】
レーザプリンタやデジタル複写機の画像書込み手段における感光体上へのレーザ光の結像は、１回の走査で複数ラインずつ画像を書き込むという用途から、一つのレーザ光の結像位置から１ライン分ずらして次のレーザ光が結像されている。具体的には、二つの光ビームは互いに副走査方向に像面上で数１０μｍオーダーの間隔で近接しており、印字密度が４００ｄｐｉ（本発明においては、１インチ即ち、２．５４ｃｍ当たりのドット数のことをｄｐｉ（ドットパーインチ）と定義する）で２ビームの副走査方向ピッチは６３．５μｍ、６００ｄｐｉで４２．３μｍである。このような、副走査方向に解像度分ずらした方法とは異なり、本発明では同一の場所に２本以上のレーザを入射角を変え露光面に集光させ画像形成することを特徴としている。この際の、通常の１本のレーザ（波長λ［ｎｍ］）で書き込む場合の露光面での露光エネルギーがＥである場合に、露光に使用するＮ本のレーザが同一波長（波長λ［ｎｍ］）、同一露光エネルギー（Ｅｎ）とした場合、０．９×Ｅ≦Ｅｎ×Ｎ≦１．１×Ｅの範囲にするのが好ましい。このようにすることにより、露光面ではエネルギーは確保されるが、それぞれのレーザ光の画像形成層への反射は、レーザの露光エネルギーが低いため低減され、ひいては干渉縞の発生が抑えられる。
【０１６９】
なお、上述では複数本のレーザの波長をλと同一のものを使用したが、波長の異なるものを用いても良い。この場合、λ［ｎｍ］に対して（λ−３０）＜λ１、λ２、・・・・・λｎ≦（λ＋３０）の範囲にするのが好ましい。
【０１７０】
上記画像形成方法において、熱現像する手段としては、オーブン、加熱ロール、加熱加圧ロール、ホットスタンパー、ヒートブロック等を用いて加熱或いは加熱加圧処理することにより熱現像することができる。熱現像する条件としては、ロール状の熱源接触搬送型の熱現像機を用いる場合は、ロール表面温度としては通常１２０〜１４０℃、好ましくは１２５〜１３０℃であり、接触時間としては通常１０〜３０秒、好ましくは１０〜２０秒、線圧としては通常０〜５０Ｎ／ｃｍ、好ましくは０〜１０Ｎ／ｃｍである。またヒートブロック状の熱源非接触搬送型の熱現像機を用いる場合は、画像形成材料近傍の温度としては通常１１０〜１４０℃、好ましくは１２０〜１３０℃であり、時間としては通常１０〜１８０秒、好ましくは１５〜１２０秒である。
【０１７１】
【実施例】
以下、本発明を実施例によって詳細に説明するが、本発明はこれらに限定されない。なお、本文中の水はイオン交換水を、％は特に断りのない限り質量％を表す。
【０１７２】
実施例１
《画像形成材料１−１〜１−１５の作製》
〈バッキング層形成塗工液の調製〉
下記に示す方法に従って、バッキング層形成塗工液を調製した。
【０１７３】
メチルエチルケトン８３ｇを撹拌しながら、酢酸プロピオン酸セルロース（イーストマンケミカル社製、ＣＡＰ４８２−２０）８．４２ｇ、ポリエステル樹脂（東洋紡績（株）製、バイロン２８０）０．４５ｇとを添加し、溶解した。
【０１７４】
別途、メタノール４．３２ｇにフッ素系界面活性剤（旭硝子（株）製、サーフロンＳ−３８１（有効成分７０％））０．６４ｇとフッ素系界面活性剤（大日本インキ工業（株）製、メガファッグＦ１２０Ｋ）０．２３ｇとを溶解させ、後記「化１６」に示す赤外染料１の入った溶液に、フッ素系界面活性剤溶液を添加して、赤外染料１が完全に溶解するまで充分に撹拌を行った。最後に、メチルエチルケトンに１％の濃度でディゾルバ型ホモジナイザにて分散したシリカ（富士シリシア化学（株）製、サイロービック４００４）を７．５ｇ、メチルエチルケトンで希釈し、固形分濃度２０質量％のイソシアネート化合物（日本ポリウレタン工業（株）製、コロネートＣ−３０４１）１．７８ｇとを順次添加、撹拌しバッキング層形成塗工液を調製した。
【０１７５】
〈バッキング層の塗設〉
次いで、青色染料（バイエルン社製、セレスブルーＲＲ−Ｊ）で、ビジュアルの透過濃度（コニカ（株）製のＰＤＡ−６５で小数点以下３桁まで測定）０．１５７に着色された厚さ１７５μｍの２軸延伸ポリエチレンテレフタレートフィルムを支持体として用い、その片面をバッチ式の大気圧プラズマ処理装置（イーシー化学（株）製、ＡＰ−Ｉ−Ｈ−３４０）を用いて、高周波出力が４．５ｋＷ、周波数が５ｋＨｚ、処理時間が５秒、ガス条件としてアルゴン、窒素及び水素の体積比をそれぞれ９０％、５％及び５％でプラズマ処理を行い、次いでその反対の面をコロナ放電処理（４０Ｗ／ｍ²・分）を施し、このコロナ放電処理面に、上記バッキング層形成塗工液を、乾燥膜厚が３．５０μｍになるように押し出しコータにて塗設した後、乾燥させバッキング層を形成した。
【０１７６】
〈画像形成層形成塗工液１の調製〉
（非感光性の有機銀塩Ａの調製）
４７２０ｍｌの純水にベヘン酸２６６．２ｇを８０℃で溶解した。次に、高速で撹拌しながら１．５モル／Ｌの水酸化ナトリウム水溶液５４０．２ｍｌを添加し、濃硝酸６．９ｍｌを加えた後、５５℃に冷却してベヘン酸ナトリウム溶液を得た。
【０１７７】
前述のベヘン酸ナトリウム溶液の温度を５５℃に保ったまま、１モル／Ｌの硝酸銀溶液７８０．０ｍｌを２分間かけて添加し、さらに２０分撹拌し、濾過により水溶性塩類を除去した。その後、濾液の電導度が２μＳ／ｃｍになるまで脱イオン水による水洗、濾過を繰り返し、遠心脱水を実施した後、３７℃にて質量の減少がなくなるまで温風乾燥を行い、粉末の有機銀塩Ａを得た。
【０１７８】
（非感光性有機銀分散液の調製）
次いで、ポリビニルブチラール樹脂（積水化学工業（株）製、エスレックＢＬ−５Ｚ）２．９１ｇをメチルエチルケトン２９１．４ｇに溶解し、ディゾルバ型ホモジナイザにて撹拌しながら、上記調製した１００ｇの有機銀塩Ａを徐々に添加して十分に混合した。その後、粒子径０．５ｍｍ径のジルコニアビーズを８０％充填したメディア分散機（Ｇｅｔｔｚｍａｎｎ社製）にて周速１３ｍ、ミル内滞留時間０．５分間にて分散を行ない、非感光性有機銀分散液を調製した。
【０１７９】
（画像形成層形成塗工液１の調製）
前記非感光性有機銀分散液５０．０ｇ及びメチルエチルケトン１０．０ｇを混合し撹拌しながら２０℃に保温し、ポリビニルブチラール樹脂（積水化学工業製（株）、エスレックＢＬ−５Ｚ）１２．６８ｇを添加し溶解した後に、３，４−ヒドロキシ安息香酸エチル２．６３ｇ、ベンゾ［ｅ］［１，３］オキサジン−２，４−ジオンを０．７１ｇ、７−（エチルカルボナト）−ベンゾ［ｅ］［１，３］オキサジン−２，４−ジオンを０．３６ｇ、無水テトラクロロフタル酸を０．４１ｇ、アジピン酸を０．９３ｇ、順次添加して３０分間溶解撹拌し、架橋剤として固形分２０％のポリイソシアネート化合物（日本ポリウレタン工業（株）製、コロネートＨＸ）を表１記載の量添加、撹拌し、画像形成層形成塗工液１を調製した。
【０１８０】
〈接着層形成塗工液１の調製〉
メチルエチルケトン８０．０ｇに撹拌しながら、１５．０ｇの酢酸プロピオン酸セルロース樹脂（イーストマンケミカル社製、ＣＡＰ４８２−２０）、５．０ｇのポリビニルブチラール樹脂（積水化学工業（株）製、エスレックＢＭ−Ｓ）を添加し溶解した後に、架橋剤として固形分５０％のポリイソシアネート化合物（日本ポリウレタン工業（株）、コロネート３０４１）を表１記載の量添加、撹拌し、接着層形成塗工液１を調製した。
【０１８１】
〈保護層形成塗工液１の調製〉
メチルエチルケトン１３０．０ｇに撹拌しながら、２０．０ｇの酢酸プロピオン酸セルロース樹脂（イーストマンケミカル（株）製、ＣＡＰ４８２−２０）を添加し溶解した後に、紫外線吸収剤（ビーエーエスエフ（株）製、ユビナール３０３５）０．５０ｇ、フッ素系活性剤（旭硝子（株）製、サーフロンＫＨ４０）０．１０ｇ、固形分２０％にメチルエチルケトンで希釈したシリコーン系樹脂（東亜合成（株）製、サイマックＵＳ３５２）１．００ｇ、架橋剤として固形分５０％のポリイソシアネート化合物（日本ポリウレタン工業（株）製、コロネート３０４１）を表１記載の量順次添加、溶解し、保護層樹脂溶液１を調製した。
【０１８２】
別途、メチルエチルケトン５５．０ｇにシリコーン樹脂粒子（ＧＥ東芝シリコーン（株）製、トスパール１３０）を５．０ｇ添加し、超音波分散機にて分散することにより樹脂粒子分散液を調製した。次いで、上述の保護層樹脂溶液１を撹拌しながら、シリカ分散液３．０ｇを添加した後、超音波分散して保護層形成塗工液１を調製した。
【０１８３】
〈画像形成層面側の塗布〉
上述の方法で調製した画像形成層形成塗工液１と、接着層形成塗工液１及び保護層形成塗工液１とを押し出しコータを用いてバッキング層を設けた支持体のプラズマ処理面に重層塗工後、１００℃の温風で乾燥させて画像形成材料１を作製した。なお、画像形成層の厚みは銀量が１．２５±０．０４ｇ／ｍ²、接着層及び保護層を表１記載の乾燥後の厚みに調製した。また、表中の画像形成材料１−１及び１−２は接着層を設けず画像形成層と保護層の２層で画像形成材料を作製した。
【０１８４】
表１に示す他は、画像形成材料１と同様にして画像形成材料１−１〜１−１５を作製した。
【０１８５】
《画像形成材料１−１〜１−１５の画像形成方法及び画像評価》
〈画像形成材料１−１〜１−１５の画像形成方法〉
上記作製した画像形成材料１−１〜１−１５を、室温（温度、湿度がそれぞれ２３℃、５５％）下で１２時間保存したものを用いて、各々の画像形成材料の保護層面側から、サーマルヘッドＫＳＴ型（商品名：京セラ（株）製）を用いて、３２階調となるように単位面積当たりの記録熱エネルギーを印加電圧及びパルス幅を調節し、像様に加熱して画像を記録した。
【０１８６】
〈画像評価〉
以上により得られた像様加熱した画像形成材料１−１〜１−１５の感度、最大濃度、画像のかぶり濃度を下記の基準で評価し、結果を表１に示した。
【０１８７】
【表１】

【０１８８】
（感度の測定）
形成された銀画像を、ビジュアルの透過濃度（コニカ（株）製、ＰＤＡ−６５：小数点以下３桁）で測定し、未像様加熱部分よりも１．０高い濃度を与えるエネルギーを求めこれを感度と定義し、画像試料１−１の感度を１００とする相対値で評価した（基準値に対して高エネルギーが必要な場合には１００よりも大きな数値で、反対に低エネルギーで同一の濃度が出せる場合は１００未満の数値で表す）。なお、濃度が無像域加熱部＋１．０となるエネルギー量は、濃度が無像域加熱部＋０．７〜＋１．２となる濃度の間を少なくとも３点以上測定し、直線回帰により求めた。
【０１８９】
（最大濃度：Ｄｍａｘの測定）
画像の最大印加エネルギー部におけるビジュアルの透過濃度（コニカ（株）製、ＰＤＡ−６５：小数点以下２桁）を１０点測定し、その平均値を最大濃度（Ｄｍａｘ）として評価した。
【０１９０】
（かぶり濃度：Ｄｍｉｎの測定）
画像の未印加エネルギー部分のビジュアルの透過濃度（コニカ（株）製、ＰＤＡ−６５：小数点以下３桁）を１０点測定し、その平均値をかぶり濃度（Ｄｍｉｎ）として評価した。
【０１９１】
《画像形成材料１−１〜１−１５の表面に浮き出る化合物の評価》
〈受像材料の作製〉
厚さ１８８μｍの２軸延伸ポリエチレンテレフタレートフィルム（東レ（株）製、ルミラーＴ６０）の片面に、下記の受像層形成塗工液を乾燥厚みが２０μｍとなるようにバーコータで塗布・乾燥させ、受像体を作製した。
【０１９２】

〈受像体に転写した脂肪酸の評価〉
上記作製した画像形成材料の保護層面と、前述の受像材料の受像層面とを対面させ、１５０℃の恒温槽に、２０ｇ／ｃｍ²の荷重を掛け、１５分間放置し、所定時間経過した後に室温に戻し、保護層面と受像層面とを剥離した。次いで、０．１０ｍ²の受像材料をメタノールで抽出し、定法に従ってジアゾメタンを用いて転写したベヘン酸を全てメチル化させ、定法処理後ＧＣ／ＭＳで分析し、画像形成材料１−１における受像材料に転写したベヘン酸を１００とした相対値で評価し、結果を表１に示した。
【０２１０】
実施例５
《画像形成材料５−１〜５−１４の作製》
実施例１と同様のバッキング層付き支持体を作製した。
【０２１１】
〈画像形成層形成塗工液４の作製〉
（感光性ハロゲン化銀乳剤１の調製）
水９００ｍｌ中に、平均分子量１０万のオセインゼラチン７．５ｇ及び臭化カリウム１０ｍｇを溶解して温度３５℃、ｐＨを３．０に合わせた後、硝酸銀７４ｇを含む水溶液３７０ｍｌと（９８／２）のモル比の臭化カリウムと沃化カリウムを硝酸銀と等モル及び塩化イリジウムを銀１モル当たり１×１０^-4モルとを含む水溶液３７０ｍｌを、ｐＡｇ７．７に保ちながらコントロールドダブルジェット法で１０分間かけて添加した。その後４−ヒドロキシ−６−メチル−１，３，３ａ，７−テトラザインデン０．３ｇを添加し、ＮａＯＨでｐＨを５に調整して平均粒子サイズ０．０６μｍ、粒子サイズの変動係数１２％、〔１００〕面比率８７％の立方体沃臭化銀粒子を得た。この乳剤にゼラチン凝集剤を用いて凝集沈降させ脱塩処理した後、フェノキシエタノール０．１ｇを加え、ｐＨ５．９、ｐＡｇ７．５に調整して、感光性ハロゲン化銀乳剤１を得た。
【０２１２】
（感光性有機銀塩Ａの調製）
４７２０ｍｌの純水にベヘン酸１７１．２ｇ、アラキジン酸４９．４ｇ、ステアリン酸３４．４ｇとを８０℃で溶解した。次に、高速で撹拌しながら１．５モル／Ｌの水酸化ナトリウム水溶液５４０．２ｍｌを添加し、濃硝酸６．９ｍｌを加えた後、５５℃に冷却して脂肪酸ナトリウム溶液を得た。
【０２１３】
前述の脂肪酸ナトリウム溶液の温度を５５℃に保ったまま、上記調製した感光性ハロゲン化銀乳剤１（銀０．０３８モルを含む）と純水４５０ｍｌを添加し、５分間撹拌した。次に、１モル／Ｌの硝酸銀溶液７６０．６ｍｌを２分間かけて添加し、さらに２０分撹拌し、濾過により水溶性塩類を除去した。その後、濾液の電導度が２μＳ／ｃｍになるまで脱イオン水による水洗、濾過を繰り返し、遠心脱水を実施した後、３７℃にて質量の減少がなくなるまで温風乾燥を行い、粉末の感光性有機銀塩Ａを得た。
【０２１４】
（感光性乳剤分散液の調製）
ポリビニルブチラール樹脂（積水化学工業（株）製、エスレックＢＬ−５Ｚ）２．９１ｇをメチルエチルケトン２９１．４ｇに溶解し、ディゾルバ型ホモジナイザにて撹拌しながら、上記調製した１００ｇの感光性有機銀塩Ａを徐々に添加して十分に混合した。その後、粒子径０．５ｍｍ径のジルコニアビーズを８０％充填したメディア分散機（Ｇｅｔｔｚｍａｎｎ社製）にて周速１３ｍ、ミル内滞留時間０．５分間にて分散を行ない、感光性乳剤分散液を調製した。
【０２１５】
前記感光性乳剤分散液５０ｇ及びメチルエチルケトン１０．０ｇを混合し撹拌しながら１８℃に保温し、かぶり防止剤１のメタノール溶液（１１．２％）を０．３１２ｇを加え１時間撹拌した。更に臭化カルシウムのメタノール溶液（１１．２％）を０．４１８ｇを添加して２０分撹拌し、次いで、別途メタノール１０．０ｇに、０．８９４ｇのジベンゾ−１８−クラウン−６と０．２７９ｇの酢酸カリウムを溶解させた溶液を０．３３７ｇ添加して１０分間撹拌した。次に、下記に示す色素溶液１を４．７５３ｇ添加して６０分間撹拌した後、温度を１３℃まで低下させ、さらに５０分間撹拌した。
【０２１６】

この色素溶液を添加した溶液を１３℃に保温したまま、チウロニウム化合物（例示化合物Ｔ−７）のメタノール溶液（０．９４％）を０．３９９ｇ添加して５分間撹拌した後に、ポリビニルブチラール（積水化学工業（株）製、エスレックＢＬ−５Ｚ）１５．３２ｇを添加し１０分間撹拌した後に、テトラクロロフタル酸を０．１８０ｇを添加し、さらに３０分間撹拌溶解させた。
【０２１７】
この溶液に、下記組成で調製した添加物溶液１、２、３、４、５をそれぞれ０．９７５ｇ、２．９８９ｇ、２２．９９９ｇ、０．８７３ｇ、６．４６１ｇを順次撹拌しながら添加し画像形成層形成塗工液４を調製した。
【０２１８】
〈添加物溶液１〉
メチルエチルケトンに固形分５０．０％で溶解したイソシアネート化合物（日本ポリウレタン（株）製、コロネートＨＸ）の溶液
〈添加物溶液２〉
メチルエチルケトンに固形分１．２０％で溶解したｐ−トルエンチオスルホン酸カリウムの溶液

〈添加物溶液４〉
メチルエチルケトンに固形分１０．８５％で溶解したトリハロメチル基含有化合物（例示化合物Ｐ−５４）の溶液
〈添加物溶液５〉
メチルエチルケトンに固形分６．６３％で溶解したフタラジンの溶液
【０２１９】
【化１６】

【０２２０】
〈接着層形成塗工液２の調製〉
メチルエチルケトン８０．０ｇに撹拌しながら、１５．０ｇの酢酸プロピオン酸セルロース樹脂（イーストマンケミカル社製、ＣＡＰ４８２−２０）、５．０ｇのポリビニルブチラール樹脂（積水化学工業（株）製、エスレックＢＭ−Ｓ）を添加し溶解した後に、メチルエチルケトンで固形分５０％に希釈したポリイソシアネート化合物（日本ポリウレタン工業（株）、コロネート３０４１）を表５記載の量添加、撹拌し、接着層形成塗工液２を調製した。
【０２２１】
〈保護層形成塗工液４の調製〉
メチルエチルケトン８６．５ｇに撹拌しながら、酢酸プロピオン酸セルロース樹脂（イーストマンケミカル社製、ＣＡＰ４８２−２０）１０．０５ｇ、ベンゾトリアゾール０．０１３ｇ、フッ素系活性剤（旭硝子（株）製、サーフロンＫＨ４０）０．１０ｇを添加、溶解し、次いでメチルエチルケトンで固形分２０％に希釈した架橋剤としてポリイソシアネート化合物（日本ポリウレタン工業（株）、コロネート３０４１）を表５記載の量添加、撹拌し、保護層樹脂溶液４を調製した。
【０２２２】
別途、メチルエチルケトン５５．０ｇに疎水性シリカ（富士シリシア化学（株）製、サイロホービック２００）を５．０ｇ添加し、超音波分散機にて分散することによりシリカ分散液を調製した。次いで、上述の保護層樹脂溶液４を撹拌しながら、シリカ分散液３．０ｇを添加した後、超音波分散して保護層形成塗工液４を調製した。
【０２２３】
〈画像形成層面側の塗布〉
上述の方法で調製した画像形成層形成塗工液４と、接着層形成塗工液２及び保護層形成塗工液４とを押し出しコータを用いてバッキング層を設けた支持体のプラズマ処理面に重層塗工後、７０℃の温風で乾燥させて画像形成材料を作製した。なお、画像形成層の厚みは銀量が１．８５±０．０５ｇ／ｍ²、接着層及び保護層を表５記載の乾燥後の厚みに調製した。また、表中の画像形成材料５−１及び５−２は接着層を設けず画像形成層と保護層の２層で画像形成材料を作製した。
【０２２４】
《画像形成材料５−１〜５−１４の画像形成方法及び画像評価》
〈画像記録〉
上記作製した画像形成材料５−１〜５−１４を、遮光下、室温（温度、湿度がそれぞれ２３℃、５０％）下で１２時間保存したものを用いて、下記の画像評価に適した画像信号を入力することによりドライイメージャ（コニカ（株）製、コニカドライイメージャ：ＤｒｙＰｒｏ７２２）を用いて、露光・熱現像を行い、画像試料を作製した。
【０２２５】
〈画像評価〉
以上により得られた露光・熱現像後全面露光された画像形成材料５−１〜５−１４の感度、最大濃度、画像のかぶり濃度を下記の基準で評価し、得られた結果を表５に示した。
【０２２６】
（感度の測定）
形成された銀画像を、ビジュアルの透過濃度（コニカ（株）製、ＰＤＡ−６５：小数点以下３桁）で測定し、未露光部分よりも１．０高い濃度を与える露光量の逆数を求めこれを感度と定義し、画像試料５−１の感度を１００とする相対値で評価した。なお、濃度が未露光部＋１．０となる露光量は、濃度が未露光部＋０．７〜＋１．２となる濃度の間を少なくとも３点以上測定し、直線回帰により求めた。
【０２２７】
（最大濃度：Ｄｍａｘの測定）
露光部分の最大露光部におけるビジュアルの透過濃度（コニカ（株）製、ＰＤＡ−６５：小数点以下２桁）を１０点測定し、その平均値を最大濃度（Ｄｍａｘ）として評価した。
【０２２８】
（かぶり濃度：Ｄｍｉｎの測定）
未露光部分のビジュアルの透過濃度（コニカ（株）製、ＰＤＡ−６５：小数点以下３桁）を１０点測定し、その平均値をかぶり濃度（Ｄｍｉｎ）として評価した。
【０２２９】
《画像形成材料５−１〜５−１４の表面に浮き出る化合物の評価》
〈受像体に転写した脂肪酸の評価〉
上記作製した画像形成材料を室内光５００ルクス下で１時間放置し、この画像形成材料の保護層面と、実施例１で作製した受像材料の受像層面とを対面させ、１３０℃の恒温槽に、２０ｇ／ｃｍ²の荷重を掛け、１０分間放置し、所定時間経過した後に室温に戻し、保護層面と受像層面とを剥離した。次いで、０．１０ｍ²の受像材料をメタノールで抽出し、定法に従ってジアゾメタンを用いて転写した脂肪酸を全てメチル化させ、定法処理後ＧＣ／ＭＳで分析し、画像形成材料５−１における受像材料に転写した転写した脂肪酸を１００とした相対値で評価し、得られた結果を表５に示した。
【０２３０】
【表５】

【０２５６】
【発明の効果】
本発明により、像様に加熱あるいは露光後の潜像を加熱現像した際に、表面に浮き出す化合物を低減させた画像形成材料、及び該画像形成材料を適用した画質のよい画像形成方法を提供することが出来る。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming material and an image forming method using the same.
[0002]
[Prior art]
Conventionally, in the medical and printing plate making fields, waste liquids resulting from wet processing of image forming materials have been a problem in terms of workability. In recent years, the amount of waste processing liquids has been strongly reduced from the viewpoint of environmental conservation and space saving. It is desired.
[0003]
Therefore, U.S. Pat. Nos. 3,887,378, 4,013,473, 5,416,058, 5,582,953, 5,587,350, 5,734,411 5,734,412, 5,759,752, 5,817,598, 6,093,528, 6,211,116, 6,244,766, No. 6,313,065 and the like have known direct thermal recording materials containing a non-photosensitive organic silver salt and a reducing agent on a support, and these image forming materials are converted into a thermal head or photothermally. Digital recording according to the image signal can be performed by the laser beam.
[0004]
U.S. Pat. Nos. 3,152,904, 3,457,075 or D.C. H. As described in “Dry Silver Photographic Materials” (Handbook of Imaging Materials, Inc., page 48, 1991) by Klosterboer, etc. A photothermographic material containing a reducing agent is known, and these image forming materials can be efficiently exposed by a laser imager or a laser image setter, and form a clear black image with high resolution. Can do.
[0005]
Since none of the image forming materials described above uses any solution processing chemicals, it is possible to provide a user with a simple system that does not impair the environment. However, in any image forming material, when the latent image after imagewise heating or exposure is heat-developed, a compound typified by an organic acid generated from an organic silver salt emerges on the surface of the image forming material. There is a case. This sometimes causes problems such as contamination of rolls and filters in apparatuses such as thermal printers, laser imagers, and laser image setters, and adhesion of white powder to fingers for users who handle materials after image formation.
[0006]
In order to remedy such drawbacks, direct heating recording materials containing a non-photosensitive organic silver salt and a reducing agent on a support are disclosed in European Patent Nos. 0,614,769 and 0,726,852. U.S. Pat. Nos. 6,350,561, 6,352,819, 6,352,820, etc., and in the case of an image forming material containing photosensitive silver halide, U.S. Pat. No. 6,352,819, 6,352,820, JP-A 2000-267226, 2000-284416, 2000-29283, 2000-347339, 2001-13624, etc. A composition or a material constituting the composition has been proposed.
[0007]
However, even in an image forming material to which the above-described technique is applied, the compound is still raised on the surface, and it cannot be said that the countermeasure is sufficient.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object of the present invention is to form an image in which the amount of a compound that floats on the surface when a latent image after imagewise heating or exposure is heated and developed is reduced. An object of the present invention is to provide a material and an image forming method with good image quality to which the image forming material is applied.
[0009]
[Means for Solving the Problems]
As a result of intensive studies on the above problems, the present inventor has found that in the image forming material, the concentration distribution of the crosslinking agent, the ratio of the crosslinking agent and the binder resin between the image forming layer and the protective layer, or the functional group ratio, It has been found that the use of a certain kind of cross-linking agent can reduce the emergence of the compound to the surface.
[0010]
    That is, the object of the present invention has been achieved by adopting one of the following configurations.
  [1] In an image forming material in which an image forming layer containing a non-photosensitive organic silver salt and a reducing agent and a protective layer are laminated in this order on a support,An adhesive layer is provided between the image forming layer and the protective layer; andAn image forming material, wherein the amount of the crosslinking agent per unit mass increases as the distance from the support increases.
[0012]
  [2]The crosslinking agent is an isocyanate compound[1〕RecordThe image forming materials listed.
[0019]
  [3The image forming layer containing a non-photosensitive silver salt further contains a photosensitive silver halide.[1] or [2]The image forming material described.
[0020]
  [4The photosensitive silver halide is spectrally sensitized with a sensitizing dye having a maximum absorption wavelength λmax in the range of 600 to 1100 nm.3An image forming material as described above.
[0021]
  [5] [1]-[4〕ofwhatAn image forming method, wherein the image forming material according to claim 1 is used to form a silver image by imagewise heating.
[0022]
  [6The image heating means is a thermal head [5] The image forming method described above.
[0023]
  [7] [5] Or [6An image forming method comprising: forming a silver image by using an image-forming material described above and exposing the image-wise exposure to heat under light shielding.
[0024]
  [8The image-wise exposure means is laser scanning exposure [7] The image forming method described above.
[0025]
  [9] [8In the laser scanning exposure described above, scanning exposure is performed using laser light in which the angle formed by the exposure surface and the laser light is not substantially perpendicular, and scanning exposure is performed using vertical multi-laser light whose exposure wavelength is not single. Or at least one of scanning exposure using two or more laser beams and performing image exposure.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
First, the image forming material of the present invention will be described.
[0027]
The image forming material in the first invention of the present invention is an image forming material in which an image forming layer containing a non-photosensitive organic silver salt and a reducing agent, and a protective layer are laminated in this order on a support. The image forming material in the second invention is an image forming material in which a photosensitive silver halide, an image forming layer containing a non-photosensitive organic silver salt and a reducing agent, and a protective layer are laminated in this order on a support. .
[0028]
Each form will be described below.
[1] Image forming material in the first invention of the present invention
The first aspect of the first invention of the present invention is an image forming material comprising a support and an image forming layer containing a non-photosensitive organic silver salt and a reducing agent, and a protective layer laminated in this order. An image-forming material in which the amount of the crosslinking agent per unit mass increases as the distance from the support increases.
[0029]
Thus, when the amount of the crosslinking agent per unit mass is farther from the support side, in other words, the outermost layer is increased, in the case where there is a binder resin that can react with the crosslinking agent, the crosslinking density is more closer to the surface. It is possible to increase the amount of the compound that is raised on the surface. In addition, when the number of functional groups that the cross-linking agent reacts is smaller than the number of functional groups contained in the binder resin that reacts with the functional group of the cross-linking agent, even when the cross-linking agent remains unreacted, air It gradually reacts with water or self-crosslinks due to moisture contained therein. In this case, the closer to the surface, the higher the probability of contact with moisture in the air, so that the reaction is likely to proceed, and the crosslink density can be increased near the surface.
[0030]
As a method of increasing the amount of the cross-linking agent per unit mass as the distance from the support increases, the unit in the protective layer forming layer is compared to the amount of the cross-linking agent per unit volume in the image forming layer. This can be achieved by increasing the amount of the cross-linking agent per volume. Further, by providing a plurality of image forming layers or protective layers, the amount of the cross-linking agent per unit mass increases as the distance from the support increases. Also good. In addition, when the cross-linking agent is liquid or highly soluble in the solvent used when preparing the coating liquid described below, the cross-linking agent is more exposed to the surface in the process of drying after applying the coating liquid. Therefore, the amount of the crosslinking agent per unit mass may be increased as the distance from the support is changed by changing the drying conditions.
[0031]
  Furthermore, in this aspect, an adhesive layer is provided between the image forming layer and the protective layer for the purpose of further strengthening the adhesive force.Ru. In this case, in order to increase the amount of the crosslinking agent per unit mass as the distance from the support, which is an essential requirement of the present invention, as the amount of the crosslinking agent per unit volume, the image forming layer <the adhesive layer <the protective layer, RelationshipThe
[0032]
The crosslinking agent used in this embodiment can be used without particular limitation as long as it has a functional group capable of reacting with a functional group contained in the binder resin contained in the image forming layer and the protective layer. As such a crosslinking agent, an isocyanate compound, a carbodiimide compound, a metal alkoxide, an epoxy compound, an acid anhydride, or the like can be used depending on the binder resin.
[0033]
In particular, when the functional group contained in the binder resin is a hydroxyl group, an isocyanate compound, a carbodiimide compound, and a metal alkoxide are preferable, and among them, the isocyanate compound is more preferable because the reactivity can be easily controlled.
[0034]
As such an isocyanate compound, a polyvalent isocyanate compound having two or more isocyanate groups in the molecule is preferable because the crosslinking density can be increased. Examples of such a polyvalent isocyanate compound include dimethylene diisocyanate and tetramethylene. Diisocyanate, hexanemethylene diisocyanate, 2,2-dimethylpentane diisocyanate, 2,2,4-trimethylpentane diisocyanate, decane diisocyanate, ω, ω'-diisocyanate-1,3-dimethylbenzole, ω, ω'-diisocyanate- 1,2-dimethylcyclohexane diisocyanate, ω, ω-diisocyanate-1,4-diethylbenzole, isophorone diisocyanate, 1-methylcyclohexyl-2,4-diisocyanate, ω ω′-diisocyanate-1,5-dimethylnaphthalene, ω, ω′-diisocyanate-n-propylbiphenyl, 1,3-phenylene diisocyanate, 1-methylbenzole-2,4-diisocyanate, 1,3-dimethylbenzole-2 , 6-diisocyanate, naphthalene-1,4-diisocyanate, 1,1'-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate Diphenylmethane-4,4'-diisocyanate, 2,2'-dimethyldiphenylmethane-4,4'-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate, 4,4'-di Ethoxydiphenylmethane-4,4'-diisocyanate, 2-isocyanatoethyl-2,6-diisocyanatocaproate, 1-methylbenzole-2,4,6-triisocyanate, 1,3,5-trimethylbenzene-2 , 4,6-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, triphenylmethane-4,4 ', 4'-triisocyanate, tolylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate Tetramethylene xylylene diisocyanate and the like, and dimer or trimer adduct of each of the above isocyanate compounds (for example, 2 mol of adduct of hexamethylene diisocyanate, adduct of 3 mol of hexamethylene diisocyanate, 2, 4 -G Diisocyanate 2 mol adduct, 2,4-tolylene diisocyanate 3 mol adduct, etc.), adducts of two or more different isocyanates selected from these isocyanates, and these isocyanates and divalent or 3 Polyhydric alcohol (preferably polyalcohol having up to 20 carbon atoms). Examples thereof include adducts with ethylene glycol, propylene glycol, pinacol, trimethylolpropane, etc. (for example, adducts of tolylene diisocyanate and trimethylolpropane, and adducts of hexamethylene diisocyanate and trimethylolpropane). In addition, you may use these isocyanate compounds individually by 1 type or in combination of 2 or more types.
[0035]
Moreover, as a binder resin having a hydroxyl group as a functional group, polyvinyl acetal resins such as polyvinyl formal, polyvinyl butyral, polyvinyl acetoacetal, cellulose resins such as cellulose acetate, cellulose propionate, nitrocellulose, phenoxy resins, Modified vinyl chloride resin, modified polyester resin, modified polyurethane resin, modified polyolefin resin, modified acrylic resin, etc., in which a hydroxyl group is introduced, may be used alone, or these may be used alone or in combination of two or more resins. You may use together.
[0037]
By doing in this way, the protective layer side can be made to proceed more easily with the crosslinking reaction with the crosslinking agent, and as a result, the compound that floats on the surface can be reduced. Depending on the type of binder resin to be used, it is preferable that the mass ratio of the binder resin and the crosslinking agent is represented by the following general formula (1).
[0038]
General formula (1) 1 ≦ (crosslinking agent × 100) / (binder resin) ≦ 200
In the above formula, when the amount of the crosslinking agent is (crosslinking agent × 100) / (binder resin) <1, the crosslinking may be insufficient, and the compound that floats on the surface cannot be reduced. This is not preferable. When a liquid crosslinking agent is used, if 200 <(crosslinking agent × 100) / (binder resin), an unreacted crosslinking agent may be present in the protective layer of the image forming material during image formation. Therefore, the cross-linking agent may act like a plasticizer, which is not preferable because it further promotes the compound that floats on the surface.
[0039]
As the binder resin contained in the image forming layer and the protective layer used in this embodiment, those having a hydroxyl group as a functional group capable of reacting with the crosslinking agent in the binder resin are preferable, and as the crosslinking agent, isocyanate compounds and carbodiimides are used. A compound and a metal alkoxide are preferable, and an isocyanate compound is more preferable because the reactivity is easily controlled.
[0040]
As specific examples of the binder resin having a hydroxyl group as the functional group and the isocyanate compound, those described in detail in the first embodiment can be selected and used as appropriate.
[0041]
According to a third aspect of the first invention of the present invention, there is provided an image forming material in which an image forming layer containing a non-photosensitive organic silver salt and a reducing agent and a protective layer are laminated in this order on a support. The image forming layer and the protective layer contain a binder resin and a crosslinking agent, and the number of functional groups that can react with the crosslinking agent in the image forming layer of the binder resin in the image forming layer is C1, which can react with the functional group The number of functional groups of the crosslinking agent in the image forming layer is D1, the number of functional groups that can react with the crosslinking agent in the protective layer of the binder resin in the protective layer is C2, and the number of functional groups in the protective layer that can react with the functional group When the number of functional groups of the crosslinking agent is D2, the relationship of D1 / C1 ≦ D2 / C2 is satisfied and 0 <D2 / C2 is satisfied (that is, the crosslinking agent into the protective layer) Is essential).
[0042]
By having such a relationship, the protective layer side can be more easily promoted to cross-link reaction with the cross-linking agent, and thus the compounds that float on the surface can be reduced. C2 represents the number of functional groups capable of reacting with the crosslinking agent in the protective layer, and D2 represents the number of functional groups of the crosslinking agent in the protective layer capable of reacting with the functional group as represented by the following general formula (2). More preferably.
[0043]
General formula (2) 0.05 ≦ D2 / C2 ≦ 5.0
In the above formula, when D2 / C2 <0.05, D1 / C1 ≦ D2 / C2 <0.05, and not only the protective layer but also the image forming layer may be insufficiently cross-linked. It is not preferable because the compound that appears on the surface cannot be reduced. Further, when a liquid crosslinking agent is used, if the relationship of D1 / C1 ≦ 5.0 <D2 / C2 is satisfied, an unreacted crosslinking agent is further contained in the protective layer of the image forming material during image formation. Since it may exist in the image forming layer, the cross-linking agent may act as a plasticizer, which is not preferable because it further promotes a compound that floats on the surface. Further, when the relationship of 5.0 <D1 / C1 ≦ D2 / C2, the crosslinking agent may act like a plasticizer, which not only promotes the compound that floats on the surface, but also forms an image. When an unreacted cross-linking agent is present in the layer, it is preferable that the cross-linking agent may act as an inhibitor and a necessary concentration cannot be obtained even when energy applied in the image forming method described later is applied. Absent.
[0044]
As the binder resin contained in the image forming layer and the protective layer used in this embodiment, a resin having a hydroxyl group as a functional group capable of reacting with the crosslinking agent contained in the binder resin is preferable, and the crosslinking agent is an isocyanate compound or a carbodiimide compound. Metal alkoxide is preferable, and an isocyanate compound is more preferable because it is easy to control the reactivity.
[0045]
Specific examples of the binder resin having a hydroxyl group as the functional group and the isocyanate compound described in the first aspect of the invention can be selected and used as appropriate.
[0046]
According to a fourth aspect of the first invention of the present invention, there is provided an image forming material in which an image forming layer containing a non-photosensitive organic silver salt and a reducing agent and a protective layer are laminated in this order on a support. When the cross-linking agent is contained in the image forming layer and the protective layer, the solubility parameter of the cross-linking agent contained in the image forming layer is δ1, and the solubility parameter of the cross-linking agent contained in the protective layer is δ2, the relationship of δ1 <δ2. It is characterized by that.
[0047]
The solubility parameter referred to here is a value obtained by determining the aggregation energy Δei and molecular volume Δvi per unit functional group and calculating the sum of them by the general formula (3). For example, Polymer Engineering and Science, 14, (2) 147 (1974), “Polymer Handbook, fourth edition”, 675 (John Wiley & Sons, Inc. 1998) and the like.
[0048]
General formula (3) δ = [Σ (Δei) / Σ (Δvi)]^1/2
The crosslinking agent used in this embodiment can be used without particular limitation as long as the value of the solubility parameter is δ1 <δ2, but the crosslinking resin contained in the binder resin as a binder resin contained in the image forming layer and the protective layer. When a resin having a hydroxyl group as a functional group capable of reacting with the agent is used, the crosslinking agent is preferably an isocyanate compound, a carbodiimide compound, or a metal alkoxide, and among them, the isocyanate compound is more preferable because the reactivity can be easily controlled.
[0049]
The solubility parameter of the isocyanate compound can be calculated using the values described in the literature shown above. In addition, values of several isocyanate compounds are calculated in Coating Time Report, No. 193, 9 (1992).
[0050]
As specific examples of the binder resin having a hydroxyl group as the functional group and the isocyanate compound, those described in detail in the first embodiment can be selected and used as appropriate.
[0051]
Next, a support, an image forming layer containing a non-photosensitive organic silver salt and a reducing agent, and a protective layer, which are essential components in the first invention of the present invention, will be described in detail.
[0052]
Examples of the resin for forming the support used in the image forming material of the present invention include acrylic resin, polyester, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, poly Examples of the resin film include ether ether ketone, polysulfone, polyether sulfone, polyimide, polyetherimide, and triacetyl cellulose, and a resin film obtained by laminating two or more layers of the resin.
[0053]
The support according to the present invention is preferably a film that has been stretched and annealed in terms of dimensional stability. Examples of the resin include polyester, polycarbonate, polyarylate, polyetheretherketone, and triacetylcellulose. Among them, a polyester biaxially stretched and annealed is more preferable from the viewpoint of versatility and / or cost.
[0054]
The polyester described above will be described in more detail. The polyester referred to here is a polymer compound having an ester bond in the molecular main chain, and is a polymer obtained by condensation polymerization from a diol and a dicarboxylic acid. Dicarboxylic acids are typified by terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, adipic acid, sebacic acid and the like, and diols are ethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexane. It is represented by dimethanol. In the present invention, in particular, polyethylene terephthalate (PET) or a copolymer thereof, polybutylene naphthalate (PBN) or a copolymer thereof, polybutylene terephthalate (PBT) or a copolymer thereof, and polyethylene naphthalate (PEN) and Such copolymers are preferably used. The repeating unit of these polyesters is preferably 100 or more, particularly 150 or more, and the intrinsic viscosity is preferably 0.6 dl / g or more, more preferably 0.7 dl / g or more. In such a case, the film-forming stability is excellent and preferable. Of course, these polyesters include known additives such as lubricants, stabilizers, antioxidants, viscosity modifiers, antistatic agents, colorants, and pigments. Etc. can be arbitrarily blended.
[0055]
The thickness of the support is usually 50 to 500 μm, more preferably 100 to 250 μm.
[0056]
When the image forming material of the present invention is used for medical images, the support may contain a blue dye. As such dyes, for example, Disperse dyes, Cationic dyes, Basic dyes, Acid dyes, Reactive dyes, Direct dyes, Vat dyes, Azoic dyes, Modern dyes, Union dyes, Solvent dyes, etc. are selected as appropriate. Among these, from the viewpoint of uniform dispersibility at the time of melt kneading at the time of forming the support and dye solubility at the time of preparing a coating liquid for forming a backing layer described later, Solvent dye Is preferred. In order to prevent sublimation during melt-kneading and to reduce dye alteration during kneading as much as possible, a thermal stability of 250 ° C. or higher is preferable, and a resin used as a support is extruded. When it is necessary to raise the temperature of the extruder to 300 ° C., those having a temperature of 280 ° C. or more are more preferable. For the purpose of coloring in blue among the above-mentioned dyes, a dye having λmax at 600 to 650 nm Is more preferable.
[0057]
In addition, a backing layer may be provided on the surface opposite to the surface on which the image forming layer is laminated on the support for the purposes of transportability, antistatic, and halation prevention. It is comprised with the binder resin and the various additives added as needed.
[0058]
As the binder resin for forming the backing layer, a conventionally used transparent or translucent binder resin can be selected and used as appropriate. Examples of such a binder resin include polyvinyl formal, polyvinyl acetoacetal, Polyvinyl acetal resins such as polyvinyl butyral, cellulose resins such as nitrocellulose, cellulose acetate propionate, cellulose acetate butyrate, styrene resins such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-acrylic rubber copolymer, Vinyl chloride resins such as polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, acrylic resins such as polymethyl methacrylate, polyester resins, polyurethane resins, polycarbonate resins, polyarylate resins Examples include epoxy resins, phenoxy resins, or modified products of the above-mentioned resins, and further, using epoxy group-containing compounds or acrylic group-containing compounds as a layer-forming binder resin on the premise of curing with active energy rays. Also good. These binder resins may be used alone or in combination of two or more resins.
[0059]
Moreover, when the above-mentioned binder resin has a hydroxyl group, a crosslinking agent such as a metal alkoxide having a plurality of metal alkoxide moieties in the molecule such as a conventionally known polyfunctional isocyanate compound, alkoxysilane compound, alkoxytitanium compound, etc. It may be added and cross-linked.
[0060]
As other various additives, it is preferable to contain a filler for the purpose of preventing pick-up failure in the apparatus and ensuring transportability, specifically, SiO 2₂TiO₂, BaSO_Four, ZnS, MgCO_Three, CaCO_Three, ZnO, CuO, CaO, WS₂, MoS₂, MgO, SnO₂, Al₂O_Three, Α-Fe₂O_Three, Α-FeO₂H, SiC, CeO₂, MoC, BC, WC, BN, SiN, titanium carbide, corundum, artificial diamond, garnet, garnet, quartzite, triboli, diatomaceous earth, dolomite and other inorganic fillers, polyethylene resin particles, fluororesin particles, guanamine resin particles, Examples thereof include organic fillers such as acrylic resin particles, silicon resin particles, melamine resin particles, and silk powder. In addition, it is preferable that content in the case of adding a filler contains 0.05-30 mass% in a backing layer forming composition.
[0061]
Furthermore, in order to improve the slipperiness and chargeability, the backing layer may contain a lubricant and an antistatic agent. Examples of such lubricants include fatty acids, fatty acid esters, fatty acid amides, polyoxyls. Examples include ethylene, polyoxypropylene, (modified) silicone oil, (modified) silicone resin, (modified) fluorine compound, (modified) fluorine resin, carbon fluoride, and wax. Antistatic agents include cationic surfactants, anionic surfactants, nonionic surfactants, polymeric antistatic agents, metal oxides, or those described in US Pat. No. 5,747,412. Conductive polymer, “11290 Chemical Products”, Chemical Industry Daily, p. 875-876 etc. can be mentioned.
[0062]
The thickness of the backing layer is usually about 0.5 to 10 μm, and more preferably 1.0 to 5 μm. Further, the backing layer may be formed of a single layer or a plurality of layers having different compositions.
[0063]
Furthermore, within the range that does not hinder the effect of the present invention, an antistatic layer is provided between the support and the backing layer for the purpose of preventing antistatic, and the support surface on which the backing layer is laminated in order to improve adhesion and applicability, You may modify | reform using well-known surface modification techniques, such as a corona discharge process, a plasma process, and an anchor coat process.
[0064]
Next, the image forming layer containing the non-photosensitive organic silver salt and the reducing agent as essential components in the first invention will be described in detail. In the present invention, the binder resin other than the essential components described above is included in the image forming layer. If necessary, a crosslinking agent is further added, and those described in detail above can be selected and used in a timely manner within the scope of the present invention.
[0065]
The non-photosensitive organic silver salt which is an essential component of the present invention is a silver salt of an organic carboxylic acid, and a preferable silver salt is a silver salt of an aliphatic carboxylic acid known as a fatty acid having at least 12 carbon atoms. For example, silver laurate, silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate. Similarly, silver salts of other organic carboxylic acids such as those described in British Patent 1,439,478, such as silver benzoate, can be used to form thermally developable silver images. Furthermore, silver salts such as those disclosed in JP-A-10-236004, JP-A-2000-62325, JP-A-2002-23303, European Patents 962,815, 964,300, etc., and silver of various organic carboxylic acids are used. Even if the combination of salts is a mixed crystal, it can be selected and used as appropriate in the present invention. The above-mentioned organic silver salt can be prepared with reference to the exemplified British patent and European patent.
[0066]
As a reducing agent suitable for the reduction of the non-photosensitive organic silver salt, conventionally known reducing agents can be selected and used in a timely manner, specifically, aromatic di- and tri-hydroxy compounds, aminophenols. Derivatives, p-phenylenediamine derivatives, alkoxynaphthol derivatives, pyrazolidin-3-one derivatives, pyrazolidin-3-one derivatives, indan-1,3-dione derivatives, hydroxytetronic acid, hydroxytetronimide, hydroxylamine derivatives, hydrazine derivatives, Examples include reductone, 1,2-dihydroxybenzene derivatives, gallic acid derivatives, 3,4-dihydroxybenzoic acid derivatives, and the like.
[0067]
Further, catechol, 3- (3,4-dihydroxyphenyl) propionic acid, 1,2-dihydroxybenzoic acid, and further 1,2-described in JP-A-11-245510, European Patent 978,760 and the like. Dihydroxybenzene derivatives, gallic acid such as methyl gallate, ethyl gallate, and propyl gallate and esters thereof, tannic acid, and 3,4-dihydroxy-benzoic acid esters described in JP-A-8-29916 Is preferred.
[0068]
Furthermore, a combination of compounds that can be reduced to a non-photosensitive organic silver salt by heating can be suitably used as long as the object of the present invention is not impaired. For example, JP-A-56-88136. A combination of a reducing agent and a sulfonamide phenol described in JP-A No. 62-201434, a combination of a sterically hindered phenol and a sulfonyl hydrazide reducing agent described in JP-A-8-234393, etc. Examples thereof include trityl hydrazide and combinations of formyl-phenyl-hydrazide and auxiliary reducing agents described in No. 511572, JP-A Nos. 11-511573 and 11-512539, and the like. In addition, acrylonitrile compounds described in JP-A-11-511571, JP-A-2001-513411, and 2-substituted malonodialdehyde compounds described in US Pat. No. 5,654,130 are also included in the present invention. It can be suitably used within a range that does not impede the purpose.
[0069]
Further, to the image forming layer of the first form, a toning agent, a stabilizer, an antifogging agent, a thermal solvent and the like may be further added as necessary.
[0070]
The toning agent is added to obtain a neutral black image tone at a relatively high density and a neutral gray at a relatively low density. Phthalimide and phthalazinone derivatives described in JP-A No. 117066, U.S. Pat. Nos. 3,074,809, 3,446,648, 3,844,797, 4,082,901, etc. And benzoxazinedione or naphthoxazinedione derivatives described in U.S. Pat. Nos. 3,885,967, 3,951,660, 5,599,647, British Patent 1439478, and the like.
[0071]
Stabilizers include, for example, unsaturated carbocyclic or heterocyclic compounds substituted with -SA groups, where A is hydrogen, a counter ion to compensate for the negative charge of the thiolate group, or a symmetric or asymmetric disulfide Represents a group which forms Examples of the antifogging agent include polycarboxylic acids and / or anhydrides thereof described in, for example, JP-A-58-107534, JP-A-8-6203, JP-A-2000-199936, When such a compound is added, it is usually 0.01 to 30 mole percent, preferably 0.05 to 20 mole percent based on the non-photosensitive organic silver salt present in the image forming layer. . Furthermore, as the thermal solvent, a known compound that is solid at room temperature and reversibly liquefies or softens upon heating can be selected and used as appropriate.
[0072]
In the present invention, the image forming layer may be a single layer or a plurality of layers having the same or different composition. In addition, the film thickness of a protective layer is 7.0-20.0 micrometers normally.
[0073]
As the protective layer used in the image forming material of the first form, in addition to the binder resin and the crosslinking agent described above, the protective layer is composed of the binder resin described in the backing layer added as necessary, and an additive. They can be selected and used in a timely manner.
[0074]
As an additive to be added to the protective layer, it is preferable to contain a filler for the purpose of ensuring transportability and reducing the contact area with the thermal head in the image forming method to be described later. Is preferably contained in the layer-forming composition in an amount of 0.05 to 30% by mass.
[0075]
Furthermore, the protective layer may contain a lubricant and an antistatic agent in order to improve slipperiness and chargeability. As these compounds, the lubricant and antistatic agent used in the backing layer can be selected as appropriate. The additive can be used in an amount of about 0.01 to 20% by mass, more preferably 0.05 to 10% by mass of the protective layer layer-forming component.
[0076]
In the present invention, the protective layer may be a single layer or a plurality of layers having the same or different composition. In addition, the film thickness of a protective layer is 1.0-5.0 micrometers normally.
[0077]
In the first aspect of the first aspect of the present invention, an adhesive layer is provided between the image forming layer and the protective layer described above, and these are made of a binder resin used in the image forming layer or the protective layer. The adhesive layer may be used in combination with a crosslinking agent and an additive that are appropriately selected and added as necessary. The adhesive layer may be a single layer or may be composed of a plurality of layers having the same or different compositions. In addition, the film thickness of an adhesive layer is 0.1-2.0 micrometers normally.
[0078]
In addition, the backing layer, the image forming layer, the protective layer and the adhesive layer added as necessary in the first embodiment of the present invention are applied by dissolving or dispersing the components described above in a solvent. Prepare a working solution.
[0079]
As the solvent, the solubility parameter value shown in “Polymer Handbook, fourth edition”, 675 (John Wiley & Sons, Inc. 1998) and the like is 15.0 to 30.0 (J / cm^ThreeIt is preferable to use a solvent comprising carbon, hydrogen and oxygen atoms from the viewpoint of the solubility of the resin and the drying property during production.
[0080]
Examples of such a solvent include acetone (20.3), isophorone (18.6), ethyl amyl ketone (16.8), methyl ethyl ketone (19.0), methyl isobutyl ketone (17.2) as ketones. , Cyclopentanone (21.3), cyclohexanone (20.3) and the like. As alcohols, methyl alcohol (29.7), ethyl alcohol (26.0), n-propyl alcohol (24.3), isopropyl alcohol (23.5), n-butyl alcohol (23.3), isobutyl alcohol ( 21.5), t-butyl alcohol (21.7), 2-butyl alcohol (22.1), diacetone alcohol (18.8), cyclohexanol (23.3) and the like. Examples of glycols include ethylene glycol (29.9), diethylene glycol (24.8), triethylene glycol (21.9), propylene glycol (25.8) and the like. Examples of ether alcohols include ethylene glycol monomethyl ether (23.3). Examples of ethers include diethyl ether (15.1), tetrahydrofuran (18.6), 1,3-dioxolane (17.6), 1,4-dioxane (16.2) and the like.
[0081]
Examples of the esters include ethyl acetate (18.6), n-butyl acetate (17.4), 2-butyl acetate (16.8) and the like. Examples of hydrocarbons include n-heptane (15.1), cyclohexane (16.8), toluene (18.2), xylene (18.0) and the like. However, it is not limited to these as long as the effects of the present invention are not inhibited, and these solvents can be used alone or in combination of several kinds.
[0082]
When dispersion is required when forming the coating liquid, a two-roll mill, a three-roll mill, a ball mill, a pebble mill, a cobol mill, a tron mill, a sand mill, a sand grinder, a Sqgvari attritor, a high-speed impeller disperser, a high-speed stone mill, A conventionally known disperser such as a high-speed impact mill, a disper, a high-speed mixer, a homogenizer, an ultrasonic disperser, an open kneader, or a continuous kneader can be selected at appropriate times.
[0083]
In order to apply the coating liquid prepared as described above to a support, for example, an extrusion-type extrusion coater, a reverse roll coater, a gravure roll coater, an air doctor coater, a blade coater, an air knife coater, a squeeze coater, Various known coater stations such as an impregnation coater, a bar coater, a transfer roll coater, a kiss coater, a cast coater, a spray coater, and a slide coater can be selected and used as appropriate. Among these coaters, it is preferable to use a roll coater such as an extrusion type extrusion coater or a reverse roll coater in order to eliminate unevenness in the thickness of the layer.
[0084]
In addition, when the protective layer is applied, there is no particular limitation as long as the image forming layer is not damaged, but the solvent used in the protective layer forming coating solution dissolves the image forming layer. If possible, an extrusion-type extrusion coater, gravure roll coater, bar coater or the like can be used in the above-described coater station. Of these, when a coating method such as a gravure roll coater or bar coater is used, the rotation direction of the gravure roll or bar may be forward or reverse with respect to the transport direction. May have a constant speed or a peripheral speed difference.
[0085]
Further, as described above, the coating and drying may be repeated for each layer, but the layers may be applied and dried by a wet-on-wet method. In that case, the reverse roll coater, gravure roll coater, air doctor coater, blade coater, air knife coater, squeeze coater, impregnation coater, bar coater, transfer roll coater, kiss coater, cast coater, spray coater, slide coater, extrusion coater described above. It can be applied in combination with an extrusion coater. In such a wet-on-wet multi-layer application, the upper layer is applied while the lower layer is in a wet state. Improves.
[0086]
In the present invention, the surface of the support is subjected to flame treatment, ozone treatment, glow discharge treatment, corona discharge treatment, plasma treatment, vacuum ultraviolet irradiation treatment, electron coating when the image forming layer forming coating solution is applied on the support. It is preferable to apply an image forming layer forming coating solution after performing at least one surface treatment selected from a line irradiation treatment and a radiation irradiation treatment. By treating the surface of the support in this manner, the support and The adhesion between the image forming layers can be further strengthened.
[0087]
[2] Second invention of the present invention
The image forming layer of the second invention of the present invention is characterized in that the image forming layer of the first invention embodiment further contains photosensitive silver halide (hereinafter referred to as silver halide). By containing a proper silver halide, the image forming layer can be made photosensitive, and as a result, digital writing such as a laser becomes possible.
[0088]
The silver halide, which is a feature of the second embodiment, preferably has a small average grain size in order to suppress white turbidity after image formation or to obtain good image quality, and the average grain size is preferably 0.1 μm or less. Is preferably 0.01 μm to 0.1 μm. The particle size here refers to the diameter (equivalent circle diameter) of a circle having the same area as each particle image observed with an electron microscope. The silver halide is preferably monodispersed, and more preferably 30% or less. In addition, the monodispersion here means the monodispersity calculated | required by a following formula 40% or less.
[0089]
Monodispersity (%) = (standard deviation of particle size) / (average value of particle size) × 100
The shape of the silver halide grains is not particularly limited, but the ratio occupied by the Miller index [100] plane is preferably high, and this ratio is preferably 50% or more, and more preferably 70%. The ratio of the Miller index [100] plane is calculated by using the adsorption dependency between the [111] plane and the [100] plane in the adsorption of the sensitizing dye. Tani, J .; Imaging Sci. 29, 165 (1985).
[0090]
Another preferred silver halide shape is a tabular grain. The tabular grain referred to here is an aspect ratio (r / m) where the square root of the projected area is the grain size rμm and the thickness in the vertical direction is hμm. h) is 3 or more, and among them, the aspect ratio is preferably 3 or more and 50 or less. The particle size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.08 μm. These are described in US Pat. Nos. 5,264,337, 5,314,798, 5,320,958, etc., and the desired tabular grains can be easily obtained.
[0091]
The halogen composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide. The emulsion used in the present invention is P.I. Chifie et Physique Photographic (published by Paul Montel, 1967) by Glafkides. F. Duffin's Photographic Emission Chemistry (published by The Focal Press, 1966), V.C. L. It can be prepared using a method described in Making and Coating Photographic Emulsion (published by The Focal Press, 1964) by Zelikman et al.
[0092]
The silver halide according to the present invention preferably contains metal ions belonging to Groups 6 to 11 of the periodic table. Examples of such metals include tungsten, iron, cobalt, nickel, copper, ruthenium, rhodium, Palladium, rhenium, osmium, iridium, platinum, gold and the like can be mentioned.
[0093]
These metal ions can be introduced into silver halide in the form of a metal complex or a metal complex ion. Examples of these metal complexes or metal complex ions include six-coordinate metals represented by the following general formula (I): Complexes are preferred.
[0094]
Formula (I) [ML₆]_m
In general formula (I), M represents a transition metal selected from Group 6 to 11 elements of the periodic table, L represents a ligand, and m represents 0,-, 2-, 3-, or 4-. Specific examples of the ligand represented by L include halides (fluoride, chloride, bromide and iodide), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and aco. A ligand, nitrosyl, thionitrosyl and the like can be mentioned, and ako, nitrosyl, thionitrosyl and the like are preferable. When an acoligand is present, it preferably occupies one or two of the ligands. L may be the same or different.
[0095]
Moreover, as M in general formula (I), copper, iron, rhodium, ruthenium, rhenium, iridium and osmium are preferable.
[0096]
In addition, the above-mentioned metal ion, metal complex or metal complex ion may be one kind, or two or more kinds of the same kind of metal and different kinds of metals may be used in combination, and the inclusion of these metal ions, metal complexes or metal complex ions In general, the amount is usually 1 x 10 per mole of silver halide.^-9~ 1x10^-2Moles, preferably 1 × 10^-8~ 1x10^-FourIs a mole.
[0097]
The compounds providing these metals are preferably added at the time of silver halide grain formation and incorporated into the silver halide grains. Preparation of silver halide grains, that is, nucleation, growth, physical ripening, chemical sensitization Although it may be added at any stage before and after, it is preferably added at the stage of nucleation, growth and physical ripening, and more preferably at the stage of nucleation and growth.
[0098]
In addition, it may be divided and added several times, or it can be uniformly contained in the silver halide grains. JP-A-63-29603, JP-A-2-306236, 3 As described in JP-A Nos. 167545, 4-76534, 6-110146, 5-273683, etc., the particles can be contained with a distribution.
[0099]
These metal compounds can be added by dissolving in water or an appropriate organic solvent (for example, alcohols, ethers, glycols, ketones, esters, amides). A method in which an aqueous solution or an aqueous solution in which a metal compound and sodium chloride or potassium chloride are dissolved together is added to a water-soluble silver salt solution or a water-soluble halide solution during particle formation, or a silver salt solution and a halide solution are A method in which silver halide grains are added as a third aqueous solution when mixed at the same time and silver halide grains are prepared by a three-liquid simultaneous mixing method, a method in which an aqueous solution of a required amount of a metal compound is introduced into a reaction vessel during grain formation, Timely selection of a method of adding and dissolving another silver halide grain previously doped with metal ions or complex ions when preparing silver halide It can be used Te. In addition, when added to the particle surface, a required amount of an aqueous solution of a metal compound can be charged into the reaction vessel immediately after the formation of the particle, during or after the physical ripening, or at the time of chemical ripening.
[0100]
In the present invention, the silver halide grains may or may not be desalted after the formation of the grains. However, when desalting is performed, washing with water using methods known in the art, such as a noodle method or a flocculation method. It can be desalted.
[0101]
The silver halide grains used in the present invention are preferably chemically sensitized. As a preferable chemical sensitization method, as well known in the art, for example, a sulfur sensitization method, a selenium sensitization method, and a tellurium sensitization method can be used. Further, noble metal sensitization methods such as gold compounds, platinum, palladium, iridium compounds, and reduction sensitization methods can be used.
[0102]
Furthermore, the organic acid used in forming the organic silver used in the present invention includes aliphatic carboxylic acid, carbocyclic carboxylic acid, heterocyclic carboxylic acid, heterocyclic compound, and the like, Long chain (10-30, preferably 15-25 carbon atoms) aliphatic carboxylic acids and heterocyclic carboxylic acids having a nitrogen-containing heterocyclic ring are preferred. An organic silver salt complex having a total stability constant with respect to silver ions having a ligand of 4.0 to 10.0 can also be selected and used as appropriate.
[0103]
Examples of such organic silver salts are described in Research Disclosure (hereinafter abbreviated as RD) Nos. 17029 and 29963. Of these, silver salts of fatty acids are preferably used, and silver behenate, silver arachidate, and silver stearate are particularly preferably used.
[0104]
Furthermore, in order to exhibit the effect of the present invention more effectively among the above-mentioned three kinds of fatty acids, the content of silver behenate having a high melting point of the corresponding fatty acid is set to 40% by mass or more in the total organic silver. And more preferably 60% by mass or more.
[0105]
In the present invention, the organic silver salt preferably has an average particle size of 1 μm or less and is monodispersed. Note that the average particle diameter of the organic silver salt referred to here is, for example, when the organic silver salt particles are spherical, rod-shaped, or flat-shaped particles, when considering a sphere equivalent to the volume of the organic silver salt particles. The average particle size is usually 0.01 to 0.8 μm, more preferably 0.05 to 0.5 μm. Moreover, monodispersion is synonymous with the case of silver halide, Preferably monodispersion degree is 1 to 30%. In the present invention, the organic silver salt is more preferably monodisperse particles having an average particle size of 1 μm or less, and an image having a high density can be obtained by setting the content within this range. Further, the organic silver salt preferably has tabular grains of 60% or more of the total organic silver. The organic silver salt tabular grains as used in the present invention are synonymous with the above-described photosensitive silver halide tabular grains and have an aspect ratio of 3 or more.
[0106]
Such organic silver particles are preferably pre-dispersed with a binder, a surfactant or the like, if necessary, and then dispersed and ground with a media disperser or a high-pressure homogenizer. For the preliminary dispersion, for example, a general stirrer such as an anchor type or a propeller type, a high speed rotating centrifugal radiation type stirrer (dissolver), or a high speed rotating shear type stirrer (homomixer) can be used. In addition, as the media dispersing machine, a rolling mill such as a ball mill, a planetary ball mill, and a vibrating ball mill, a bead mill that is a medium stirring mill, an attritor, and other basket mills can be used. Various types can be used, such as a type that collides with a plug or the like, a type in which liquids are collided at a high speed after dividing the liquid, and a type in which a thin orifice is passed. Further, as a medium for dispersion, ceramics such as zirconia, alumina, silicon nitride, boron nitride, or diamond can be selected and used as appropriate.
[0107]
The reducing agent contained in the image forming layer of the second invention of the present invention includes phenols, polyphenols having two or more phenol groups, naphthols, bis in addition to the reducing agent described in the first embodiment. Naphthols, polyhydroxybenzenes having 2 or more hydroxyl groups, polyhydroxynaphthalenes having 2 or more hydroxyl groups, ascorbic acids, 3-pyrazolidones, pyrazolin-5-ones, pyrazolines, phenylenediamines, hydroxyl Amines, hydroquinone monoethers, hydrooxamic acids, hydrazides, amide oximes, N-hydroxyureas and the like can be selected and used as appropriate.
[0108]
Among the reducing agents described above, when an aliphatic carboxylic acid silver salt is used as the organic silver salt, preferred reducing agents include polyphenols in which two or more phenol groups are linked by an alkylene group or sulfur, in particular, a phenol group. An alkyl group (for example, a methyl group, an ethyl group, a propyl group, a t-butyl group, a cyclohexyl group, etc.) or an acyl group (for example, an acetyl group, a propionyl group, etc.) at least one of the positions adjacent to the hydroxy substitution position of Polyphenols in which two or more of the substituted phenol groups are linked by an alkylene group or sulfur, such as 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, 1 , 1-bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane, 1,1-bis (2-hydro Ci-3,5-di-t-butylphenyl) methane, 1,1-bis (2-hydroxy-3-methyl-5-tert-butylphenyl) methane, 1,1-bis [2-hydroxy-3- Methyl-5- (1-methylcyclohexyl) phenyl] methane, (2-hydroxy-3-tert-butyl-5-methylphenyl)-(2-hydroxy-5-methylphenyl) methane, 6,6'-benzylidene- Bis (2,4-di-tert-butylphenol), 6,6'-benzylidene-bis (2-tert-butyl-4-methylphenol), 6,6'-benzylidene-bis (2,4-dimethylphenol) 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -2-methylpropane, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -1-cyclohexylme 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -1- (2,4-dimethyl-3-cyclohexenyl) methane, 1,1-bis (2-hydroxy-3,5- Dimethylphenyl) -1- (2-methyl-4-cyclohexenyl) methane, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -1- (2-methyl-4-cyclohexyl) methane, , 1,5,5-tetrakis (2-hydroxy-3,5-dimethylphenyl) -2,4-ethylpentane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2 -US Patents 3,589,903, 4,021,249 or British Patent 1,486,148 such as bis (4-hydroxy-3,5-di-t-butylphenyl) propane Description and JP-A-51-51933, JP-A-50-36110, JP-A-50-116023, JP-A-52-84727, JP-A-2001-56527, JP-A-2001-42469, JP-A-2001-92075, JP-A-2001-188323, or Special Polyphenol compounds described in JP-B 51-35727, bisnaphthols described in US Pat. No. 3,672,904, for example, 2,2′-dihydroxy-1,1′-binaphthyl, 6, 6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl, 6,6'-dinitro-2,2'-dihydroxy-1,1'-binaphthyl, bis (2-hydroxy-1-naphthyl) Methane, 4,4'-dimethoxy-1,1'-dihydroxy-2,2'-binaphthyl, etc., and U.S. Pat. No. 3,801,321 Sulfonamidophenols or sulfonamidonaphthols as described in the description, such as 4-benzenesulfonamidophenol, 2-benzenesulfonamidophenol, 2,6-dichloro-4-benzenesulfonamidophenol, 4-benzenesulfone Amidonaphthol and the like can be mentioned.
[0109]
The amount of the reducing agent contained in the image-forming layer of the present invention varies depending on the type of organic silver salt, reducing agent, and other additives, but generally 0.05 to 10 mol per mol of organic silver salt. Preferably, it is 0.1-3 mol. Moreover, within the range of this addition amount, two or more reducing agents described above may be used in combination.
[0110]
Furthermore, in the image forming layer of the second form, in addition to the above-mentioned essential components, binder resin and crosslinking agent added as necessary, a silver saving agent, antifogging agent, toning agent, sensitizing dye, A substance exhibiting supersensitization (hereinafter abbreviated as supersensitizer) may be added. The silver saving agent referred to here refers to a compound that can reduce the amount of silver necessary to obtain a certain silver image density, and there are various possible mechanisms of this reducing function. A compound having a function of improving the covering power is preferred. Here, the covering power of developed silver refers to the optical density per unit amount of silver.
[0111]
Examples of such silver saving agents include U.S. Pat. Nos. 5,496,695, 5,545,505, 5,545,507, 5,637,449, and 5, No. 5,654,130, No. 5,635,339, No. 5,545,515, No. 5,686,228, JP-A-10-339929, No. 11-84576, No. 11-95365. Hydrazine compounds described in JP-A Nos. 11-95366, 11-109546, 11-119372, 11-119373, JP-A 2000-356835, 2001-27790, 2001-174947, etc. A vinyl compound is mentioned.
[0112]
Further, a Schiff base formed from a dehydration condensation reaction between an alkoxysilane compound having two or more primary or secondary amino groups or a salt thereof and / or an alkoxysilane compound having one or more primary amino groups and a ketone compound It can be suitably used as a silver saving agent. The term “having two or more primary or secondary amino groups” as used herein means that only two or more primary amino groups, two or more secondary amino groups, and further primary and secondary amino groups, respectively. The term “alkoxysilane compound salt” refers to an adduct of an inorganic acid or organic acid that can form an onium salt with an amino group and an alkoxysilane compound.
[0113]
Examples of such alkoxysilane compounds or salts thereof and Schiff bases include those described below, but alkoxysilane compounds or salts thereof having two or more intramolecular primary or secondary amino groups, And / or as long as it is a Schiff base formed from a dehydration condensation reaction between an alkoxysilane compound having one or more primary amino groups and a ketone compound, it is not limited to these compounds.
[0114]
[Chemical 1]

[0115]
[Chemical 2]

[0116]
[Chemical 3]

[0117]
[Formula 4]

[0118]
[Chemical formula 5]

[0119]
[Chemical 6]

[0120]
The antifogging agent added to the image forming layer of the second invention for the purpose of improving raw storage stability and image storage stability is preferably a halogen compound represented by the following general formula.
[0121]
[Chemical 7]

[0122]
In the general formula, X₁, X₂And X_ThreeRepresents a hydrogen atom, a halogen atom, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group or an aryl group, at least one of which is a halogen atom. Y represents —NR—C (═O) —, —C (═O) —, —Z—C (═O) —, —ZS (═O) —, —SO— or —SO.₂-Represents an integer of 0 to 2, and m represents 1 to 10. R represents a hydrogen atom or an alkyl group, and R may form a ring structure with Q described later. Furthermore, Z represents an oxygen atom or a sulfur atom.
[0123]
In the general formula, Q represents an alkyl group, an aryl group, or a heterocyclic group. These groups may have a substituent. The alkyl represented by Q in the general formula is a linear, branched or cyclic alkyl group, preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms. The alkyl group represented by Q may have a substituent, and such a substituent may be any group as long as it does not adversely affect the microencapsulation. Examples of such substituents include halogen atoms, alkenyl groups, alkynyl groups, aryl groups, heterocyclic groups (including N-substituted nitrogen-containing heterocyclic groups, such as morpholino groups), alkoxycarbonyl groups, and aryloxycarbonyl groups. , Carbamoyl group, imino group, imino group substituted with N atom, thiocarbonyl group, carbazoyl group, cyano group, thiocarbamoyl group, aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or aryloxy) carbonyloxy group Sulfonyloxy group, acylamide group, sulfonamide group, ureido group, thioureido group, imide group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, (alkyl or aryl) ) Sulfonyl ureido group, a nitro group, (alkyl or aryl) sulfonyl group, a sulfamoyl group, a phosphoric acid amide or a group containing a phosphoric acid ester structure, a silyl group, and the like. These substituents may be further substituted with these substituents.
[0124]
The aryl group represented by Q in the general formula is a monocyclic or condensed ring aryl group, preferably having 6 to 24 carbon atoms, more preferably 6 to 20 carbon atoms. Examples of such monocyclic or condensed aryl groups include phenyl, naphthyl, anthracenyl, phenanthrenyl, naphthacenyl, triphenylenyl, and the like. The aryl group represented by Q may have a substituent that does not adversely affect image formation. Examples of such a substituent include a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, and a heterocyclic ring. Group (including N-substituted nitrogen-containing heterocyclic group, for example, morpholino group), alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted with N atom, thiocarbonyl group, carbazoyl group, cyano Group, thiocarbamoyl group, aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or aryloxy) carbonyloxy group, sulfonyloxy group, acylamide group, sulfonamide group, ureido group, thioureido group, imide group, (alkoxy Or aryloxy) carbonylamino group Sulfamoylamino group, semicarbazide group, thiosemicarbazide group, (alkyl or aryl) sulfonylureido group, nitro group, (alkyl or aryl) sulfonyl group, sulfamoyl group, group containing phosphoric acid amide or phosphoric ester structure, silyl group Etc. These substituents may be further substituted with these substituents.
[0125]
Furthermore, the heterocyclic group represented by Q in the general formula is a 4- to 8-membered saturated or unsaturated heterocyclic group containing at least one atom of nitrogen, oxygen, sulfur, selenium, or tellurium, and these are a simple group. It may be a ring or may form a condensed ring with another ring. Such a heterocyclic group is preferably a 5- to 6-membered unsaturated heterocyclic group optionally having a condensed ring. The heterocyclic ring that may have such a condensed ring is preferably an imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiadiazole, oxadiazole, Quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, indolenine, tetrazaindene, more preferably imidazole, pyridine , Pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthy Jin, it quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, be mentioned tetrazaindene and the like. The heterocyclic group represented by Q may have a substituent that does not adversely affect image formation. Examples of such a substituent include the same groups as those for the aryl group described above. .
[0126]
Examples of the halogen compound represented by the above general formula include the compounds exemplified below.
[0127]
[Chemical 8]

[0128]
[Chemical 9]

[0129]
[Chemical Formula 10]

[0130]
Embedded image

[0131]
Embedded image

[0132]
Embedded image

[0133]
Furthermore, U.S. Pat. Nos. 3,874,946, 4,756,999, 5,028,523, 5,340,712, 5,369,000, No. 5,464,737, European Patent Nos. 600,587, 605,981, 631,176, JP-B 54-44212, JP-B 51-9694, JP-A 50-137126 Publication No. 50-89020, No. 50-119624, No. 55-140833, No. 59-57234, JP-A-7-2781, No. 7-5621, No. 9-90550, No. 9-160164. 9-160167, 9-244177, 9-244178, 9-258367, 9-265150, 9-288328, 9-319022, 10-197 88, 10-197989, 11-242304, JP-A 2000-2963, 2000-112070, 2000-284212, 2000-284410, 2001-33911, etc. Can be selected and used in a timely manner, and these compounds can be used alone or in combination of two or more.
[0134]
As an antifoggant, in addition to the above-mentioned halogen compounds, JP-A-58-107534, JP-A-8-6203, JP-A-2000-199936, JP-A-2000-321711, JP-A-2002-23304, JP-A-2002-49121, etc. The described polycarboxylic acids or anhydrides thereof, JP-A-51-78227, JP-A-53-20923, JP-A-55-140833, JP-A-7-209797, JP-A-8-314059, JP-A-9-43760 Thiosulfonic acid or a salt thereof, or a derivative thereof described in JP 2000-284400 A, JP 2000-284413 A, JP 2000-284413 A, JP 2002-62616 A, 2002-62617, Carboxylic acid and sulfinic acid described in JP 2002-90935 A and the like. There may be added within a range that does not impair the object of its salts such as the present invention.
[0135]
Examples of toning agents added for the purpose of improving the silver tone after development include imides (for example, phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (for example, succinimide, 3-phenyl- 2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione); naphthalimides (eg N-hydroxy-1,8-naphthalimide); cobalt complexes (eg cobalt hexamine trifluoro) Acetate), mercaptans (eg, 3-mercapto-1,2,4-triazole); N- (aminomethyl) aryl dicarboximides (eg, N- (dimethylaminomethyl) phthalimide); blocked pyrazoles , Isothiuronium ) Derivatives and certain photobleaching agents (eg, N, N′-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8- (3,6-dioxaoctane) bis (isothione) A combination of uronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole); a merocyanine dye (for example, 3-ethyl-5-((3-ethyl-2-benzothiazolinylidene (benzothiazolidine) Nylidene))-1-methylethylidene) -2-thio-2,4-oxazolidinedione); phthalazinone, phthalazinone derivatives or metal salts of these derivatives (eg 4- (1-naphthyl) phthalazinone, 6-chlorophthala Dinone, 5,7-dimethyloxyphthalazinone, and 2,3-dihydro-1,4-phthalazinedi A combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); a combination of phthalazine + phthalic acid; a phthalazine (addition of phthalazine) And maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivatives and anhydrides thereof (for example, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic acid) A combination with at least one compound selected from acid anhydrides); quinazolinediones, benzoxazines, naltoxazine derivatives; benzoxazine-2,4-diones (eg, 1,3-benzoxazine-2,4-dione) ); Pyrimidines and asymmetry Triazines (for example, 2,4-dihydroxypyrimidine) and tetraazapentalene derivatives (for example, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene) ). Preferred examples of the color tone include phthalazone and phthalazine.
[0136]
In addition, as long as the objective of this invention is not inhibited, you may add a toning agent to the protective layer mentioned later.
[0137]
The sensitizing dye can be used without particular limitation as long as it has absorption with respect to the oscillation wavelength of a laser light source used for scanning exposure described in detail in an image forming method described later.
[0138]
Among them, the use of a semiconductor laser having a wavelength of 700 to 1200 nm is preferable as the laser light source, and the size of the light source is preferable. As the sensitizing dye having the absorption maximum wavelength in such a wavelength range, for example, a cyanine dye , Rhodocyanine dyes, oxonol dyes, carbocyanine dyes, dicarbocyanine dyes, tricarbocyanine dyes, tetracarbocyanine dyes, pentacarbocyanine dyes, styryl dyes, pyrylium dyes, metal-containing dyes such as metal phthalocyanines and metal porphyrins, etc. Specifically, Chem. Rev. 92, 1197 (1992), etc., JP-A-48-3527, JP-A-49-111121, JP-A-58-145936, JP-A-59-191032, JP-A-59-192242, JP-A-60-80841, JP-A 62-284343, JP-A-2-105135, JP-A-3-67242, JP-A-3-163440, JP-A-4-182439, JP-A-5-341432, JP-A-7-13295, JP-A-11-30833, 11-352628, JP-A-2000-95958, 2000-98524, 2000-122207, 2000-169741, 2000-17938, 2000-273329, 2000-321704, 2000-321527, 2001-64527, 2001-83655. , And select the dyes described in JP-T 9-510022, etc. in a timely manner It can be used.
[0139]
Supersensitizers are described in RD17643, JP-B-9-25500, JP-A-43-4933, JP-A-59-19032, JP-A-59-192242, JP-A-5-341432, and the like. A compound can be selected and used in a timely manner. In the present invention, a heteroaromatic mercapto compound represented by the following general formula (3), which is substantially represented by the general formula (4) that produces the mercapto compound, can be used. Disulfide compounds can be used.
[0140]
General formula (3) Ar-SM
General formula (4) Ar-SS-Ar
In the general formula (3), M represents a hydrogen atom or an alkali metal atom, and Ar represents a heteroaromatic ring or condensed heteroaromatic ring having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. The heteroaromatic ring is preferably benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotelrazole, imidazole, oxazole, pyrazole, triazole, triazine, pyrimidine, pyridazine, pyrazine, pyrazine, Pyridine, purine, quinoline or quinazoline. Moreover, Ar in General formula (4) is synonymous with the case of the said general formula (M).
[0141]
The heteroaromatic ring includes, for example, a halogen atom (for example, Cl, Br, I), a hydroxy group, an amino group, a carboxyl group, and an alkyl group (for example, one or more carbon atoms, preferably 1 to 4 carbon atoms). And a substituent selected from the group consisting of an alkoxy group (for example, one having 1 or more carbon atoms, preferably 1 to 4 carbon atoms).
[0142]
In the present invention, in order to achieve high sensitivity, it is more preferable to use the following thyronium compound as a supersensitizer.
[0143]
Embedded image

[0144]
Embedded image

[0145]
Furthermore, a thiuonium compound described in JP-A No. 2001-330918 can be selected and used in a timely manner within the scope of the object of the present invention.
[0146]
The supersensitizer is preferably used in an image forming layer containing an organic silver salt and silver halide grains in an amount of 0.001 to 1.0 mol per mol of silver, particularly 0.01 per mol of silver. It is preferable to be in the range of ˜0.5 mol.
[0147]
The image forming layer of the second form may further contain a macrocyclic compound containing a hetero atom, and a 9-membered ring or more containing at least one of a nitrogen atom, an oxygen atom, a sulfur atom and a selenium atom as a hetero atom. Are preferred, and 12 to 24 membered rings are more preferred. As such a compound, the following Pederson was synthesized with crown ether in 1967, and many compounds have been synthesized since its unique report. These compounds are C.I. J. et al. Pederson, Journalof American chemical society vol, 86 (2495), 7017-7036 (1967), G. et al. W. Gokel, S.M. H, Korzeniowski, “Macrocyclic polyethr synthesis”, Springer-Vergal, (1982), JP 2000-347343, and the like.
[0148]
Further, in the image forming layer of the second invention, for example, surfactants, antioxidants, stabilizers, plasticizers, ultraviolet absorbers, coating aids and the like may be used in addition to the additives described above. These additives and compounds described in RD Item 17029 (June 1978, p. 9-15) can be selected and used in a timely manner within a range not impairing the object of the present invention.
[0149]
In the second invention, the image forming layer may be a single layer or a plurality of layers having the same or different composition. The film thickness of the image forming layer is usually 5 to 30 μm.
[0150]
The protective layer used in the image forming material of the second invention can be formed in the same manner as the protective layer described in the first embodiment, and the backing layer to be installed as necessary is also the first embodiment. It can be formed in the same manner as the backing layer described above. For the purpose of preventing halation, the backing layer may further contain, as an antihalation agent, a compound having absorption in the oscillation wavelength region of a laser that will be described in detail in the image forming method described later.
[0151]
In addition, the thickness of a protective layer is 1.0-5.0 micrometers normally, and the thickness of a backing layer is about 0.5-10 micrometers normally.
[0152]
In addition, the image forming layer, the protective layer, and the backing layer to be installed as necessary in the second invention of the present invention should be prepared as a coating solution by the method described in the first embodiment. In addition, the image forming material can be formed by applying in the same manner.
[0153]
Next, an image forming method using the image forming material of the first invention of the present invention will be described.
[0154]
The image forming method of the present invention is characterized in that the image forming material of the first invention is heated imagewise from the protective layer side to form a silver image.
[0155]
In the above image forming method, a laser or thermal head in the near infrared to infrared region can be used as the image-like heating means. Among them, the thermal and thermal heads can be used from the viewpoint of the compactness and maintainability of the apparatus. It is preferable to use a head.
[0156]
Such thermal heads have been widely used for many years, such as melt transfer systems such as label printers, thermal coloring systems such as thermal paper, and sublimation transfer systems such as dye transfer. However, a line type may be used, but a line type in which a heating element is arranged so as to cover the entire width of the image forming material is preferable.
[0157]
The line-shaped thermal head may be one in which heating elements are arranged in a row in the main scanning direction which is usually widely used, or JP-A-6-91912, 8-258305, 9-193438. No., JP 2000-198229 A, etc., in which heating elements are arranged in a staggered manner, or two rows as described in JP 10-315518 A, JP 2001-180026 A, etc. An arrangement having a preheating unit as described in JP-A-2002-46297 or the like may be used. Further, the shape of each heating element may be a generally used rectangular shape, or may be a trapezoidal shape or a comb-like stepped shape as described in JP-A-7-76117. . Further, the surface temperature distribution at the time of applying a pulse of one heating element may be uniform as a whole, or as described in JP-A-60-58877, 61-230959, etc. It may be in a form that becomes high temperature.
[0158]
The glaze shape of the thermal head may be full glaze, partial glaze, or other known shapes. The recording density of the heating element cannot be generally defined by the input image, but is usually 150 to 600 dots / inch, preferably 200 to 400 dots / inch. The gradation of the image can be obtained by changing the period of the input pulse, the application time, the application voltage, the duty cycle, and the like. The temperature of the thermal head surface is usually in the range of 300 to 400 ° C. when energy is applied, and the pressure between the platen roll and the thermal head (platen pressure) is 1 to 6 N / cm in order to transmit heat uniformly.²Is preferable.
[0159]
Next, an image forming method using the image forming material of the second invention of the present invention will be described.
[0160]
The image forming method of the present invention is characterized in that the image forming material of the second invention is imagewise exposed from the protective layer side and then heated on the entire surface (hereinafter referred to as heat development) to form a silver image.
[0161]
In the image forming material of the second invention, the image forming layer can be made photosensitive by containing photosensitive silver halide in the image forming layer. In addition to the performance of the image forming material of the first invention, Furthermore, digital exposure writing such as a laser becomes possible.
[0162]
In the above image forming method, it is preferable to use a laser capable of scanning exposure as a light source as a means for imagewise exposure, and as a laser used for such scanning exposure, generally well-known ruby laser, YAG Solid lasers such as laser and glass laser; He-Ne laser, Ar ion laser, Kr ion laser, CO₂Laser, CO laser, He-Cd laser, N₂Gas laser such as laser and excimer laser; InGaP laser, AlGaAs laser, GaAsP laser, InGaAs laser, InAsP laser, CdSnP₂Lasers, semiconductor lasers such as GaSb lasers; chemical lasers, dye lasers, etc. can be selected and used in a timely manner, but among these, semiconductor lasers with wavelengths of 700-1200 nm are used due to maintenance and light source size problems. It is preferable to use it.
[0163]
In addition, the beam spot diameter on the material exposure surface when scanned by the image forming material is generally 4 to 75 μm as a short axis diameter and as a long axis diameter in a laser used in a laser imager or a laser image setter. The laser beam scanning speed can be set to an optimum value for each image forming material depending on the sensitivity and laser power at the laser oscillation wavelength unique to the image forming material.
[0164]
Further, in the laser for scanning exposure described above, by adjusting the angle formed by the exposure surface and the laser beam, the wavelength of the laser, and the number of lasers used, the image obtained from the image forming material of the present invention is clear without interference fringes. Can be obtained. In addition, this means may perform them independently and may combine 2 or more types of aspects.
[0165]
The first aspect described above is characterized in that an image is formed by scanning exposure using a laser beam in which the angle formed by the laser beam and the exposure surface of the image forming material is not substantially perpendicular. In this way, by shifting the incident angle from the vertical, even when reflected light at the interlayer interface is generated, the optical path difference reaching the image forming layer becomes large, so that scattering or attenuation of the laser light in the optical path occurs. Interference fringes are less likely to occur. Here, “not to be substantially vertical” means that the angle closest to the vertical during laser scanning is neither 90 degrees in the main scanning direction nor the sub-scanning direction, and preferably in the main scanning direction. At least one of the sub-scanning directions is preferably 55 to 88 degrees, and more preferably 60 to 86 degrees.
[0166]
The second aspect is characterized in that an image is formed by scanning exposure using a vertical multilaser having a non-single exposure wavelength. When scanning with such a vertical multi-laser beam having a width in wavelength, the generation of interference fringes is reduced as compared with a scanning laser beam of a vertical single mode. The term “vertical multi” as used herein means that the exposure wavelength is not single, and the normal exposure wavelength distribution is 5 nm or more, preferably 10 nm or more. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.
[0167]
Further, the third aspect is characterized in that an image is formed by scanning exposure using two or more lasers. As such an image forming method using a plurality of lasers, it is used in an image writing means of a laser printer or a digital copying machine that writes an image line by line in one scanning because of a demand for higher resolution and higher speed. This technique is known, for example, from JP-A-60-166916. This is a method in which laser light emitted from a light source unit is deflected and scanned by a polygon mirror and imaged on a photoconductor via an fθ lens or the like, and is the same laser scanning optical apparatus in principle as a laser imager. .
[0168]
The image formation of the laser beam on the photosensitive member in the image writing means of a laser printer or digital copying machine is for one line from the image formation position of one laser beam because of the application of writing an image for each line by one scanning. The next laser beam is imaged by shifting. Specifically, the two light beams are close to each other on the image plane in the sub-scanning direction with an interval of the order of several tens of μm, and the print density is 400 dpi (in the present invention, one dot, that is, dots per 2.54 cm). The pitch is defined as dpi (dot per inch)), and the sub-scanning direction pitch of the two beams is 63.5 μm, and 600 dpi is 42.3 μm. Unlike the method of shifting the resolution in the sub-scanning direction as described above, the present invention is characterized in that two or more lasers are converged on the exposure surface by changing the incident angle at the same place to form an image. In this case, when the exposure energy on the exposure surface when writing is performed with one ordinary laser (wavelength λ [nm]) is E, N lasers used for exposure have the same wavelength (wavelength λ [nm]. ]), The same exposure energy (En) is preferably in the range of 0.9 × E ≦ En × N ≦ 1.1 × E. By doing so, energy is ensured on the exposure surface, but the reflection of each laser beam to the image forming layer is reduced because the exposure energy of the laser is low, and thus the occurrence of interference fringes is suppressed.
[0169]
In the above description, a plurality of lasers having the same wavelength as λ are used. However, lasers having different wavelengths may be used. In this case, it is preferable that (λ−30) <λ1, λ2,... Λn ≦ (λ + 30) is satisfied with respect to λ [nm].
[0170]
In the image forming method, as a means for heat development, heat development can be performed by heating or heat-pressure treatment using an oven, a heat roll, a heat-pressure roll, a hot stamper, a heat block, or the like. As the conditions for heat development, when using a roll-type heat source contact conveyance type heat developing machine, the roll surface temperature is usually 120 to 140 ° C, preferably 125 to 130 ° C, and the contact time is usually 10 to 10 ° C. 30 seconds, preferably 10 to 20 seconds, and the linear pressure is usually 0 to 50 N / cm, preferably 0 to 10 N / cm. In the case of using a heat developing device of a heat block type heat source non-contact conveyance type, the temperature in the vicinity of the image forming material is usually 110 to 140 ° C., preferably 120 to 130 ° C., and the time is usually 10 to 180 seconds. , Preferably 15 to 120 seconds.
[0171]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. In addition, the water in a text represents ion-exchange water, and% represents mass% unless otherwise specified.
[0172]
Example 1
<< Production of Image Forming Materials 1-1 to 1-15 >>
<Preparation of backing layer forming coating solution>
A backing layer forming coating solution was prepared according to the method shown below.
[0173]
While stirring 83 g of methyl ethyl ketone, 8.42 g of cellulose acetate propionate (manufactured by Eastman Chemical Co., CAP482-20) and 0.45 g of polyester resin (manufactured by Toyobo Co., Ltd., Byron 280) were added and dissolved.
[0174]
Separately, 4.34 g of methanol and 0.64 g of a fluorosurfactant (Asahi Glass Co., Ltd., Surflon S-381 (active ingredient 70%)) and a fluorosurfactant (manufactured by Dainippon Ink Industries, Ltd., MegaFag) F120K) 0.23 g is dissolved, and a fluorosurfactant solution is added to the solution containing the infrared dye 1 shown in “Chemical Formula 16” below, and the infrared dye 1 is sufficiently dissolved. Stirring was performed. Finally, 7.5 g of silica dispersed in methyl ethyl ketone with a dissolver type homogenizer at a concentration of 1% (Fuji Silysia Chemical Co., Ltd., Silovic 4004) was diluted with methyl ethyl ketone, and an isocyanate compound (solid content concentration 20 mass%) 1.78 g of Coronate C-3041 (manufactured by Nippon Polyurethane Industry Co., Ltd.) was sequentially added and stirred to prepare a backing layer forming coating solution.
[0175]
<Coating of backing layer>
Next, with a blue dye (manufactured by Bavaria, Ceres Blue RR-J), a visual transmission density (measured to 3 digits after the decimal point with PDA-65 manufactured by Konica Corp.) of 157 μm thick colored to 0.157 A biaxially stretched polyethylene terephthalate film is used as a support, and one side of the film is used as a batch type atmospheric pressure plasma processing apparatus (AP-I-H-340, manufactured by EC Chemical Co., Ltd.). Plasma treatment is performed at a frequency of 5 kHz, a treatment time of 5 seconds, and gas conditions of argon, nitrogen and hydrogen volume ratios of 90%, 5% and 5%, respectively, and then the opposite surface is treated with corona discharge (40 W / m²The above backing layer forming coating solution was applied to the corona discharge treated surface by an extrusion coater so that the dry film thickness was 3.50 μm, and then dried to form a backing layer.
[0176]
<Preparation of image forming layer forming coating solution 1>
(Preparation of non-photosensitive organic silver salt A)
266.2 g of behenic acid was dissolved at 4O <0> C in 4720 ml of pure water. Next, 540.2 ml of a 1.5 mol / L sodium hydroxide aqueous solution was added while stirring at a high speed, 6.9 ml of concentrated nitric acid was added, and the mixture was cooled to 55 ° C. to obtain a sodium behenate solution.
[0177]
While maintaining the temperature of the sodium behenate solution at 55 ° C., 780.0 ml of a 1 mol / L silver nitrate solution was added over 2 minutes, stirred for another 20 minutes, and water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration were repeated until the electric conductivity of the filtrate reached 2 μS / cm, and centrifugal dehydration was carried out, followed by drying with hot air at 37 ° C. until there was no decrease in mass, and powdered organic silver Salt A was obtained.
[0178]
(Preparation of non-photosensitive organic silver dispersion)
Next, 2.91 g of polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., ESREC BL-5Z) was dissolved in 291.4 g of methyl ethyl ketone, and 100 g of the organic silver salt A prepared above was stirred while stirring with a dissolver type homogenizer. Slowly added and mixed well. Then, dispersion was performed at a peripheral speed of 13 m and a residence time in the mill of 0.5 minutes using a media dispersing machine (manufactured by Gettzmann) filled with 80% zirconia beads having a particle diameter of 0.5 mm, and non-photosensitive organic silver dispersion A liquid was prepared.
[0179]
(Preparation of image forming layer forming coating solution 1)
50.0 g of the non-photosensitive organic silver dispersion and 10.0 g of methyl ethyl ketone were mixed and kept at 20 ° C. with stirring, and 12.68 g of polyvinyl butyral resin (Sekisui Chemical Co., Ltd., S-REC BL-5Z) was added. After dissolution, 2.63 g of ethyl 3,4-hydroxybenzoate, 0.71 g of benzo [e] [1,3] oxazine-2,4-dione, 7- (ethyl carbonate) -benzo [e] [1,3] Oxazine-2,4-dione (0.36 g), tetrachlorophthalic anhydride (0.41 g), and adipic acid (0.93 g) were sequentially added and dissolved and stirred for 30 minutes. % Polyisocyanate compound (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HX) was added in the amounts shown in Table 1 and stirred to prepare an image forming layer forming coating solution 1.
[0180]
<Preparation of adhesive layer forming coating solution 1>
While stirring to 80.0 g of methyl ethyl ketone, 15.0 g of cellulose acetate propionate resin (manufactured by Eastman Chemical Co., CAP482-20), 5.0 g of polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., ESREC BM-S) ) Is added and dissolved, and then a polyisocyanate compound having a solid content of 50% (Nippon Polyurethane Industry Co., Ltd., Coronate 3041) is added and stirred as a cross-linking agent to prepare an adhesive layer forming coating solution 1 did.
[0181]
<Preparation of protective layer forming coating solution 1>
While stirring to 130.0 g of methyl ethyl ketone, 20.0 g of cellulose acetate propionate resin (manufactured by Eastman Chemical Co., Ltd., CAP482-20) was added and dissolved, and then an ultraviolet absorber (manufactured by BISF Co., Ltd., ubinal) 3035) 0.50 g, fluorine-based activator (Asahi Glass Co., Ltd., Surflon KH40) 0.10 g, silicone resin diluted with methyl ethyl ketone to 20% solids (Toa Gosei Co., Ltd., Cymac US352) 1.00 g Then, a polyisocyanate compound having a solid content of 50% (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate 3041) as a crosslinking agent was sequentially added and dissolved in the amounts shown in Table 1 to prepare a protective layer resin solution 1.
[0182]
Separately, 5.0 g of silicone resin particles (manufactured by GE Toshiba Silicone Co., Ltd., Tospearl 130) was added to 55.0 g of methyl ethyl ketone, and dispersed with an ultrasonic disperser to prepare a resin particle dispersion. Next, 3.0 g of silica dispersion was added while stirring the protective layer resin solution 1 described above, and then ultrasonically dispersed to prepare a protective layer forming coating solution 1.
[0183]
<Application on the image forming layer side>
The image-forming layer-forming coating solution 1 prepared by the above method, the adhesive-layer-forming coating solution 1 and the protective-layer-forming coating solution 1 are extruded on the plasma-treated surface of the support provided with a backing layer using a coater. After the multilayer coating, the image forming material 1 was produced by drying with hot air of 100 ° C. The image forming layer has a silver amount of 1.25 ± 0.04 g / m.²The adhesive layer and the protective layer were prepared to the thicknesses after drying shown in Table 1. Further, the image forming materials 1-1 and 1-2 in the table were not provided with an adhesive layer, and an image forming material was prepared with two layers of an image forming layer and a protective layer.
[0184]
Image forming materials 1-1 to 1-15 were produced in the same manner as the image forming material 1 except for those shown in Table 1.
[0185]
<< Image Forming Method and Image Evaluation of Image Forming Materials 1-1 to 1-15 >>
<Image Forming Method of Image Forming Materials 1-1 to 1-15>
From the protective layer surface side of each image forming material, the image forming materials 1-1 to 1-15 prepared above were stored at room temperature (temperature and humidity were 23 ° C. and 55%, respectively) for 12 hours. Using a thermal head KST type (trade name: manufactured by Kyocera Corporation), the recording heat energy per unit area is adjusted so as to obtain 32 gradations, the applied voltage and pulse width are adjusted, and the image is heated to form an image. Recorded.
[0186]
<Image evaluation>
The sensitivity, maximum density, and fog density of the image-formed heated image forming materials 1-1 to 1-15 obtained as described above were evaluated according to the following criteria. The results are shown in Table 1.
[0187]
[Table 1]

[0188]
(Measurement of sensitivity)
The formed silver image was measured by visual transmission density (PDA-65 manufactured by Konica Corporation, 3 digits after the decimal point), and the energy giving 1.0 density higher than the non-image-like heated part was obtained and obtained. It was defined as sensitivity, and was evaluated with a relative value where the sensitivity of the image sample 1-1 was 100 (when higher energy is required than the reference value, the numerical value is larger than 100, on the contrary, the same density with lower energy) Is represented by a numerical value less than 100). The energy amount at which the density becomes the non-image area heating part +1.0 was determined by measuring at least three points between the densities at which the density becomes the non-image area heating part +0.7 to +1.2 and performing linear regression. .
[0189]
(Maximum concentration: measurement of Dmax)
The visual transmission density (manufactured by Konica Corporation, PDA-65: 2 digits after the decimal point) in the maximum applied energy part of the image was measured at 10 points, and the average value was evaluated as the maximum density (Dmax).
[0190]
(Fog density: Dmin measurement)
Ten points of visual transmission density (PDA-65 manufactured by Konica Corporation, 3 digits after the decimal point) of the unapplied energy portion of the image were measured, and the average value was evaluated as the fog density (Dmin).
[0191]
<< Evaluation of compounds floating on the surfaces of the image forming materials 1-1 to 1-15 >>
<Production of image receiving material>
The following image-receiving layer-forming coating solution is applied and dried on one side of a 188 μm-thick biaxially stretched polyethylene terephthalate film (Lumirror T60, manufactured by Toray Industries, Inc.) with a bar coater so that the dry thickness is 20 μm. Was made.
[0192]

<Evaluation of fatty acid transferred to image receptor>
The protective layer surface of the image-forming material prepared above and the image-receiving layer surface of the above-described image-receiving material are faced to each other in a thermostatic bath at 150 ° C. and 20 g / cm.²The film was allowed to stand for 15 minutes, and after a predetermined time had passed, it was returned to room temperature, and the protective layer surface and the image receiving layer surface were peeled off. Then 0.10m²The image-receiving material was extracted with methanol, all the behenic acid transferred using diazomethane was methylated according to a conventional method, analyzed by GC / MS after regular processing, and the behenic acid transferred to the image-receiving material in the image forming material 1-1 was analyzed. Evaluation was made with a relative value of 100, and the results are shown in Table 1.
[0210]
Example 5
<< Preparation of Image Forming Materials 5-1 to 5-14 >>
A support with a backing layer similar to that in Example 1 was produced.
[0211]
<Preparation of image forming layer forming coating solution 4>
(Preparation of photosensitive silver halide emulsion 1)
In 900 ml of water, 7.5 g of ossein gelatin having an average molecular weight of 100,000 and 10 mg of potassium bromide were dissolved, adjusted to a temperature of 35 ° C. and a pH of 3.0, and then 370 ml of an aqueous solution containing 74 g of silver nitrate (98/2 ) In a molar ratio of potassium bromide and potassium iodide equal to silver nitrate and iridium chloride at 1 × 10 5 per silver mole^-Four370 ml of an aqueous solution containing 1 mol was added over 10 minutes by the controlled double jet method while maintaining pAg 7.7. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 5 with NaOH, the average particle size was 0.06 μm, and the particle size variation coefficient was 12%. Cubic silver iodobromide grains having a [100] face ratio of 87% were obtained. This emulsion was coagulated and precipitated using a gelatin flocculant and desalted, and 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and pAg 7.5 to obtain photosensitive silver halide emulsion 1.
[0212]
(Preparation of photosensitive organic silver salt A)
In 4720 ml of pure water, 171.2 g of behenic acid, 49.4 g of arachidic acid, and 34.4 g of stearic acid were dissolved at 80 ° C. Next, 540.2 ml of a 1.5 mol / L sodium hydroxide aqueous solution was added while stirring at a high speed, 6.9 ml of concentrated nitric acid was added, and the mixture was cooled to 55 ° C. to obtain a sodium fatty acid solution.
[0213]
While maintaining the temperature of the fatty acid sodium solution at 55 ° C., the above-prepared photosensitive silver halide emulsion 1 (containing 0.038 mol of silver) and 450 ml of pure water were added and stirred for 5 minutes. Next, 760.6 ml of a 1 mol / L silver nitrate solution was added over 2 minutes, the mixture was further stirred for 20 minutes, and water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration are repeated until the electric conductivity of the filtrate reaches 2 μS / cm, and centrifugal dehydration is performed, followed by drying with hot air at 37 ° C. until there is no decrease in mass, and the powder photosensitivity. Organic silver salt A was obtained.
[0214]
(Preparation of photosensitive emulsion dispersion)
While dissolving 2.91 g of polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., ESREC BL-5Z) in 291.4 g of methyl ethyl ketone, stirring with a dissolver type homogenizer, 100 g of the photosensitive organic silver salt A prepared above was dissolved. Slowly added and mixed well. Thereafter, dispersion was performed at a peripheral speed of 13 m and a residence time in the mill of 0.5 minutes using a media dispersing machine (manufactured by Gettzmann) filled with 80% zirconia beads having a particle diameter of 0.5 mm. Prepared.
[0215]
50 g of the photosensitive emulsion dispersion and 10.0 g of methyl ethyl ketone were mixed and kept at 18 ° C. with stirring. 0.312 g of a methanol solution (11.2%) of the antifoggant 1 was added and stirred for 1 hour. Further, 0.418 g of a methanol solution of calcium bromide (11.2%) was added and stirred for 20 minutes, and then separately added to 10.0 g of methanol, 0.894 g of dibenzo-18-crown-6 and 0.279 g. 0.337 g of a solution in which potassium acetate was dissolved was added and stirred for 10 minutes. Next, 4.753 g of the dye solution 1 shown below was added and stirred for 60 minutes, then the temperature was lowered to 13 ° C., and the mixture was further stirred for 50 minutes.
[0216]

While maintaining the solution to which the dye solution was added at 13 ° C., 0.399 g of a methanol solution (0.94%) of a thiuonium compound (Exemplary Compound T-7) was added and stirred for 5 minutes, and then polyvinyl butyral (Sekisui After adding 15.32 g of Chemical Industries Co., Ltd. product, ESREC BL-5Z) and stirring for 10 minutes, 0.180 g of tetrachlorophthalic acid was added and further stirred and dissolved for 30 minutes.
[0217]
To this solution, 0.975 g, 2.989 g, 22.999 g, 0.873 g, and 6.461 g of additive solutions 1, 2, 3, 4, and 5 prepared with the following composition were respectively added while stirring sequentially. A forming layer forming coating solution 4 was prepared.
[0218]
<Additive solution 1>
Solution of isocyanate compound (Nihon Polyurethane Co., Ltd., Coronate HX) dissolved in methyl ethyl ketone at a solid content of 50.0%
<Additive solution 2>
A solution of potassium p-toluenethiosulfonate dissolved in methyl ethyl ketone at a solid content of 1.20%

<Additive solution 4>
A solution of a trihalomethyl group-containing compound (Exemplary Compound P-54) dissolved in methyl ethyl ketone at a solid content of 10.85%
<Additive solution 5>
A solution of phthalazine dissolved in methyl ethyl ketone at a solid content of 6.63%
[0219]
Embedded image

[0220]
<Preparation of adhesive layer forming coating solution 2>
While stirring to 80.0 g of methyl ethyl ketone, 15.0 g of cellulose acetate propionate resin (manufactured by Eastman Chemical Co., CAP482-20), 5.0 g of polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., ESREC BM-S) ) Was added and dissolved, and then the polyisocyanate compound diluted with methyl ethyl ketone to a solid content of 50% (Nippon Polyurethane Industry Co., Ltd., Coronate 3041) was added in the amount shown in Table 5 and stirred to obtain an adhesive layer forming coating solution 2 Prepared.
[0221]
<Preparation of protective layer forming coating solution 4>
While stirring to 86.5 g of methyl ethyl ketone, 10.05 g of cellulose acetate propionate resin (manufactured by Eastman Chemical Co., CAP482-20), 0.013 g of benzotriazole, fluorine-based activator (manufactured by Asahi Glass Co., Ltd., Surflon KH40) 0 .10 g was added and dissolved, and then a polyisocyanate compound (Nippon Polyurethane Industry Co., Ltd., Coronate 3041) was added as a crosslinking agent diluted with methyl ethyl ketone to a solid content of 20%, stirred, and the protective layer resin solution 4 was prepared.
[0222]
Separately, 5.0 g of hydrophobic silica (manufactured by Fuji Silysia Chemical Co., Ltd., Silo Hovic 200) was added to 55.0 g of methyl ethyl ketone, and dispersed with an ultrasonic disperser to prepare a silica dispersion. Next, 3.0 g of silica dispersion was added while stirring the protective layer resin solution 4 described above, and then ultrasonically dispersed to prepare a protective layer forming coating solution 4.
[0223]
<Application on the image forming layer side>
The image forming layer forming coating solution 4 prepared by the above method, the adhesive layer forming coating solution 2 and the protective layer forming coating solution 4 are extruded on the plasma-treated surface of the support provided with a backing layer using a coater. After the multilayer coating, the image forming material was produced by drying with warm air of 70 ° C. The image forming layer has a silver amount of 1.85 ± 0.05 g / m.²The adhesive layer and the protective layer were prepared to the thicknesses after drying shown in Table 5. Further, the image forming materials 5-1 and 5-2 in the table were not provided with an adhesive layer, and an image forming material was prepared with two layers of an image forming layer and a protective layer.
[0224]
<< Image Forming Method and Image Evaluation of Image Forming Materials 5-1 to 5-14 >>
<Image recording>
An image suitable for the following image evaluation using the image forming materials 5-1 to 5-14 produced as described above and stored for 12 hours under light shielding at room temperature (temperature and humidity are 23 ° C. and 50%, respectively). By inputting a signal, exposure and heat development were performed using a dry imager (manufactured by Konica Corporation, Konica Dry Imager: DryPro 722) to prepare an image sample.
[0225]
<Image evaluation>
The sensitivity, maximum density, and fog density of the image-forming materials 5-1 to 5-14 that were exposed as a whole after exposure and thermal development were evaluated according to the following criteria, and the results obtained are shown in Table 5. Indicated.
[0226]
(Measurement of sensitivity)
The formed silver image was measured with a visual transmission density (PDA-65 manufactured by Konica Corporation, 3 digits after the decimal point), and the reciprocal of the exposure amount giving a density 1.0 higher than the unexposed portion was obtained. Was defined as sensitivity, and evaluation was performed with a relative value where the sensitivity of the image sample 5-1 was 100. In addition, the exposure amount at which the density becomes an unexposed area +1.0 was determined by linear regression after measuring at least three points between the densities at which the density becomes + unexposed area +0.7 to +1.2.
[0227]
(Maximum concentration: measurement of Dmax)
Ten points of visual transmission density (manufactured by Konica Corporation, PDA-65: two digits after the decimal point) in the maximum exposure part of the exposed part were measured, and the average value was evaluated as the maximum density (Dmax).
[0228]
(Fog density: Dmin measurement)
The visual transmission density of unexposed part (Konica Corporation, PDA-65: 3 digits after the decimal point) was measured at 10 points, and the average value was evaluated as the fog density (Dmin).
[0229]
<< Evaluation of compounds floating on the surface of image forming materials 5-1 to 5-14 >>
<Evaluation of fatty acid transferred to image receptor>
The prepared image forming material is allowed to stand under 500 lux of room light for 1 hour, the protective layer surface of the image forming material and the image receiving layer surface of the image receiving material prepared in Example 1 are faced to each other in a thermostat bath at 130 ° C. 20 g / cm²The film was allowed to stand for 10 minutes, and after a predetermined time had passed, it was returned to room temperature, and the protective layer surface and the image receiving layer surface were peeled off. Then 0.10m²The image-receiving material was extracted with methanol, and all the fatty acids transferred using diazomethane were methylated according to a conventional method, analyzed by GC / MS after the regular processing, and the transferred fatty acid transferred to the image-receiving material in the image-forming material 5-1. Evaluation was performed with a relative value of 100, and the obtained results are shown in Table 5.
[0230]
[Table 5]

[0256]
【The invention's effect】
According to the present invention, there are provided an image forming material in which a compound that floats on a surface when an image-like heated or exposed latent image is heated and developed, and an image forming method with good image quality using the image forming material are provided. I can do it.

Claims (9)

In an image forming material in which an image forming layer containing a non-photosensitive organic silver salt and a reducing agent and a protective layer are laminated in this order on a support, an adhesive layer is provided between the image forming layer and the protective layer. And the amount of the crosslinking agent per unit mass increases as the distance from the support increases. 2. The image forming material according to claim 1, wherein the crosslinking agent is an isocyanate compound . 3. The image forming material according to claim 1, wherein a photosensitive silver halide is further contained in the image forming layer containing a non-photosensitive silver salt . 4. The image forming material according to claim 3, wherein the photosensitive silver halide is spectrally sensitized with a sensitizing dye having a maximum absorption wavelength [lambda] max in the range of 600 to 1100 nm. An image forming method, wherein the image forming material according to any one of claims 1 to 4 is heated imagewise to form a silver image. 6. The image forming method according to claim 5, wherein the imagewise heating means is a thermal head. A silver image is formed by using the image forming material according to claim 3 or 4 to form an imagewise exposure and then heating under light shielding to form a silver image. 8. The image forming method according to claim 7, wherein the imagewise exposure means is laser scanning exposure. 9. The laser scanning exposure according to claim 8, wherein scanning exposure is performed using a laser beam in which an angle formed by the exposure surface and the laser beam is not substantially perpendicular, and a vertical multi-laser beam having a non-single exposure wavelength is used. An image forming method, wherein exposure is performed by at least one of scanning exposure and scanning exposure using two or more laser beams.