JP4032164B2 - Photothermographic material, image recording method and image forming method - Google Patents

Description

【００４６】
【化２】

【００４７】
【化３】

【００４８】
【化４】

【００４９】
以下に、一般式（２）で表される化合物の具体例を示すが、本発明はこれらに限定されない。
【００５０】
【化５】

【００５１】
【化６】

【００５２】
【化７】

【００５３】
【化８】

【００５４】
【化９】

【００５５】
以下に、一般式（３）で表される化合物の具体例を示すが、本発明はこれらに限定されない。
【００５６】
【化１０】

【００５７】
【化１１】

【００５８】
【化１２】

【００５９】
【化１３】

【００６０】
本発明に係る上記記載の一般式（１）〜（３）で表される化合物は、各々、市販の化合物を用いることができるが、また、Ｃｈｅｍ．Ｐｈａｒｍ．Ｂｕｌｌｅｔｉｎ，３１（８），２６３２（１９８３）、Ｊ．Ｃｈｅｍ．Ｓｏｃ．，Ｓｅｃｔｉｏｎ Ｂ Ｐｈｙｓｉｃａｌ Ｏｒｇａｎｉｃ Ｃｈｅｍｉｓｔｒｙ，Ｐａｒｔ１．ｐｐ．１４５〜１４８（１９７１）、Ｊ．Ａｍｅｒ．Ｃｈｅｍ．Ｓｏｃ．７７，１９０９（１９５５），Ｏｒｇ．Ｐｒｅｐ．Ｐｒｏｃｅｄ．Ｉｎｔ．２８（５），６０９（１９９６）、Ｃｈｅｍ．Ｂｅｒ．４４，１２３６（１９１１）、Ｊ．Ａｍｅｒ．Ｃｈｅｍ．Ｓｏｃ．６０，２５０２（１９３８）、Ｂｕｌｌ．Ｓｏｃ．Ｋｈｉｍ．Ｆｒ．２５（３）１７３（１９０１）、Ｃｈｅｍ．Ａｂｓｔｒ．９８６１（１９６０）、独国特許第２，９７０，１８号、Ｊｕｓｔｕｓ Ｌｉｅｂｉｇｓ Ａｎｎ．Ｃｈｅｍ．３００ ２９９（１８９８）等に記載の方法を参考にして合成することが出来る。
【００６１】
本発明に係る上記記載の一般式（１）、（２）で表される化合物の混合比（質量比）としては、１００：５〜１００：１００が好ましく、更に好ましくは１００：１０〜１００：５０である。
【００６２】
本発明に係る上記記載の一般式（１）、（３）で表される化合物の混合比としては、１００：５〜１００：３００が好ましいが、更に好ましくは１００：１０〜１００：１５０である。
【００６３】
また、本発明に係る上記記載の一般式（１）、（２）、（３）で表される化合物の混合比としては、１００：（５〜１００）：（５〜３００）が好ましく、更に好ましくは、１００：（１０〜５０）：（１０〜１５０）である。
【００６４】
本発明に係るハロゲン化銀粒子は光センサーとして機能する。本発明においては、画像形成後の白濁を低く抑え、且つ、良好な画質を得るために平均粒子サイズが０．１μｍ以下が好ましく、更に好ましくは０．０１μｍ〜０．１μｍであり、特に好ましくは０．０２μｍ〜０．０８μｍである。
【００６５】
ここでいう粒子サイズとは、ハロゲン化銀粒子が立方体或いは八面体のいわゆる正常晶である場合には、ハロゲン化銀粒子の稜の長さをいう。また、正常晶でない場合、例えば球状、棒状、或いは平板状の粒子の場合には、ハロゲン化銀粒子の体積と同等な球を考えたときの直径をしめす。また、ハロゲン化銀は単分散であることが好ましい。
【００６６】
ここでいう単分散とは、下記式で求められる単分散度が４０％以下の場合を表す。本発明においては、単分散度としては、３０％以下が更に好ましく、特に好ましくは０．１％以上２０％以下である。
【００６７】
単分散度＝（粒径の標準偏差）／（粒径の平均値）×１００
本発明においては、ハロゲン化銀粒子が平均粒径０．１μｍ以下で、且つ、単分散粒子であることがより好ましく、この範囲にすることで画像の粒状性も向上する。
【００６８】
ハロゲン化銀粒子の形状については、特に制限はないが、ミラー指数〔１００〕面の占める割合が高いことが好ましく、この割合が５０％以上、更には７０％以上、特に８０％以上であることが好ましい。ミラー指数〔１００〕面の比率は増感色素の吸着における〔１１１〕面と〔１００〕面との吸着依存性を利用したＴ．Ｔａｎｉ，Ｊ．Ｉｍａｇｉｎｇ Ｓｃｉ．，２９，１６５（１９８５）により求めることができる。
【００６９】
またもう一つの好ましいハロゲン化銀の形状は、平板粒子である。ここでいう平板粒子とは、投影面積の平方根を粒径ｒμｍとして垂直方向の厚みがｈμｍである場合のアスペクト比＝ｒ／ｈが３以上のものをいう。その中でも、更に好ましくはアスペクト比が３以上５０以下である。また粒径は０．１μｍ以下であることが好ましく、さらに０．０１μｍ〜０．０８μｍが好ましい。これらは米国特許第５，２６４，３３７号、同第５，３１４，７９８号、同第５，３２０，９５８号等に記載されており、上記特許を参考にして目的の平板状粒子を得ることができる。
【００７０】
本発明においてこれらの平板状粒子を用いた場合、更に画像の鮮鋭性も向上する。ハロゲン組成としては特に制限はなく、塩化銀、塩臭化銀、塩沃臭化銀、臭化銀、沃臭化銀、沃化銀のいずれであってもよい。本発明に係るＡｇＸ粒子は、Ｐ．Ｇｌａｆｋｉｄｅｓ著Ｃｈｉｍｉｅ ｅｔ Ｐｈｙｓｉｑｕｅ Ｐｈｏｔｏｇｒａｐｈｉｑｕｅ（Ｐａｕｌ Ｍｏｎｔｅｌ社刊、１９６７年）、Ｇ．Ｆ．Ｄｕｆｆｉｎ著 Ｐｈｏｔｏｇｒａｐｈｉｃ Ｅｍｕｌｓｉｏｎ Ｃｈｅｍｉｓｔｒｙ（Ｔｈｅ Ｆｏｃａｌ Ｐｒｅｓｓ刊、１９６６年）、Ｖ．Ｌ．Ｚｅｌｉｋｍａｎ ｅｔ ａｌ著 Ｍａｋｉｎｇ ａｎｄ Ｃｏａｔｉｎｇ Ｐｈｏｔｏｇｒａｐｈｉｃ Ｅｍｕｌｓｉｏｎ（Ｔｈｅ Ｆｏｃａｌ Ｐｒｅｓｓ刊、１９６４年）等に記載された方法を用いて作製されたＡｇ乳剤を用いて調製することが出来る。
【００７１】
本発明に係るハロゲン化銀は有機銀塩に対して０．７５〜３０質量％の量で含有されることが好ましい。
【００７２】
本発明に係るハロゲン化銀には、周期表の６族から１１族に属する金属イオンを含有することが好ましい。上記の金属としては、Ｗ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｒｕ、Ｒｈ、Ｐｄ、Ｒｅ、Ｏｓ、Ｉｒ、Ｐｔ、Ａｕが好ましい。
【００７３】
これらの金属イオンは金属錯体または金属錯体イオンの形でハロゲン化銀に導入できる。これらの金属錯体または金属錯体イオンとしては、下記一般式で表される６配位金属錯体が好ましい。
【００７４】
一般式〔ＭＬ₆〕^m
式中、Ｍは周期表の６〜１１族の元素から選ばれる遷移金属、Ｌは配位子、ｍは０、−、２−、３−または４−を表す。Ｌで表される配位子の具体例としては、ハロゲン化物（弗化物、塩化物、臭化物及び沃化物）、シアン化物、シアナート、チオシアナート、セレノシアナート、テルロシアナート、アジド及びアコの各配位子、ニトロシル、チオニトロシル等が挙げられ、好ましくはアコ、ニトロシル及びチオニトロシル等である。アコ配位子が存在する場合には、配位子の一つまたは二つを占めることが好ましい。Ｌは同一でもよく、また異なっていてもよい。
【００７５】
Ｍとして特に好ましい具体例は、ロジウム（Ｒｈ）、ルテニウム（Ｒｕ）、レニウム（Ｒｅ）、イリジウム（Ｉｒ）及びオスミウム（Ｏｓ）である。
【００７６】
以下に遷移金属錯体イオンの具体例を示すが本発明はこれらに限定されない。
１：〔ＲｈＣｌ₆〕^3-
２：〔ＲｕＣｌ₆〕^3-
３：〔ＲｅＣｌ₆〕^3-
４：〔ＲｕＢｒ₆〕^3-
５：〔ＯｓＣｌ₆〕^3-
６：〔ＩｒＣｌ₆〕^4-
７：〔Ｒｕ（ＮＯ）Ｃｌ₅〕^2-
８：〔ＲｕＢｒ₄（Ｈ₂Ｏ）〕^2-
９：〔Ｒｕ（ＮＯ）（Ｈ₂Ｏ）Ｃｌ₄〕^-
１０：〔ＲｈＣｌ₅（Ｈ₂Ｏ）〕^2-
１１：〔Ｒｅ（ＮＯ）Ｃｌ₅〕^2-
１２：〔Ｒｅ（ＮＯ）（ＣＮ）₅〕^2-
１３：〔Ｒｅ（ＮＯ）Ｃｌ（ＣＮ）₄〕^2-
１４：〔Ｒｈ（ＮＯ）₂Ｃｌ₄〕^-
１５：〔Ｒｈ（ＮＯ）（Ｈ₂Ｏ）Ｃｌ₄〕^-
１６：〔Ｒｕ（ＮＯ）（ＣＮ）₅〕^2-
１７：〔Ｆｅ（ＣＮ）₆〕^3-
１８：〔Ｒｈ（ＮＳ）Ｃｌ₅〕^2-
１９：〔Ｏｓ（ＮＯ）Ｃｌ₅〕^2-
２０：〔Ｃｒ（ＮＯ）Ｃｌ₅〕^2-
２１：〔Ｒｅ（ＮＯ）Ｃｌ₅〕^-
２２：〔Ｏｓ（ＮＳ）Ｃｌ₄（ＴｅＣＮ）〕^2-
２３：〔Ｒｕ（ＮＳ）Ｃｌ₅〕^2-
２４：〔Ｒｅ（ＮＳ）Ｃｌ₄（ＳｅＣＮ）〕^2-
２５：〔Ｏｓ（ＮＳ）Ｃｌ（ＳＣＮ）₄〕^2-
２６：〔Ｉｒ（ＮＯ）Ｃｌ₅〕^2-
２７：〔Ｉｒ（ＮＳ）Ｃｌ₅〕^2-
これらの金属イオン、金属錯体または金属錯体イオンは一種類でもよいし、同種の金属及び異種の金属を二種以上併用してもよい。これらの金属イオン、金属錯体または金属錯体イオンの含有量としては、一般的にはハロゲン化銀１モル当たり１×１０^-9〜１×１０^-2モルが適当であり、好ましくは１×１０^-8〜１×１０^-4モルである。
【００７７】
これらの金属のイオンまたは錯体イオンを提供する化合物は、ハロゲン化銀粒子形成時に添加し、ハロゲン化銀粒子中に組み込まれることが好ましく、ハロゲン化銀粒子の調製、つまり核形成、成長、物理熟成、化学増感の前後のどの段階で添加してもよいが、特に核形成、成長、物理熟成の段階で添加するのが好ましく、更には核形成、成長の段階で添加するのが好ましく、最も好ましくは核形成の段階で添加する。
【００７８】
添加に際しては、数回に渡って分割して添加してもよく、ハロゲン化銀粒子中に均一に含有させることもできるし、特開昭６３−２９６０３号、特開平２−３０６２３６号、同３−１６７５４５号、同４−７６５３４号、同６−１１０１４６号、同５−２７３６８３号等に記載されている様に粒子内に分布を持たせて含有させることもできる。好ましくは粒子内部に分布をもたせることができる。
【００７９】
これらの金属化合物は、水或いは適当な有機溶媒（例えば、アルコール類、エーテル類、グリコール類、ケトン類、エステル類、アミド類）に溶解して添加することができるが、例えば金属化合物の粉末の水溶液もしくは金属化合物とＮａＣｌ、ＫＣｌとを一緒に溶解した水溶液を、粒子形成中の水溶性銀塩溶液または水溶性ハライド溶液中に添加しておく方法、或いは銀塩溶液とハライド溶液が同時に混合されるとき第３の水溶液として添加し、３液同時混合の方法でハロゲン化銀粒子を調製する方法、粒子形成中に必要量の金属化合物の水溶液を反応容器に投入する方法、或いはハロゲン化銀調製時に予め金属のイオンまたは錯体イオンをドープしてある別のハロゲン化銀粒子を添加して溶解させる方法等がある。特に、金属化合物の粉末の水溶液もしくは金属化合物とＮａＣｌ、ＫＣｌとを一緒に溶解した水溶液を水溶性ハライド溶液に添加する方法が好ましい。
【００８０】
粒子表面に添加する時には、粒子形成直後または物理熟成時途中もしくは終了時または化学熟成時に必要量の金属化合物の水溶液を反応容器に投入することもできる。
【００８１】
本発明に係るハロゲン化銀粒子は粒子形成後に脱塩してもしなくてもよいが、脱塩を施す場合、ヌードル法、フロキュレーション法等、当業界で知られている方法を用いて水洗することにより脱塩することができる。
【００８２】
本発明に係るハロゲン化銀粒子は化学増感されていることが好ましい。好ましい化学増感法としては当業界でよく知られているように硫黄増感法、セレン増感法、テルル増感法を用いることができる。また金化合物や白金、パラジウム、イリジウム化合物等の貴金属増感法や還元増感法を用いることができる。硫黄増感法、セレン増感法、テルル増感法に好ましく用いられる化合物としては公知の化合物を用いることができるが、特開平７−１２８７６８号等に記載の化合物を使用することができる。テルル増感剤としては例えばジアシルテルリド類、ビス（オキシカルボニル）テルリド類、ビス（カルバモイル）テルリド類、ジアシルテルリド類、ビス（オキシカルボニル）ジテルリド類、ビス（カルバモイル）ジテルリド類、Ｐ＝Ｔｅ結合を有する化合物、テルロカルボン酸塩類、テルロカルボン酸エステル類、ジ（ポリ）テルリド類、テルリド類、テルロール類、テルロアセタール類、テルロスルホナート類、Ｐ−Ｔｅ結合を有する化合物、含Ｔｅヘテロ環類、テルロカルボニル化合物、無機テルル化合物、コロイド状テルルなどを用いることができる。貴金属増感法に好ましく用いられる化合物としては例えば塩化金酸、カリウムクロロオーレート、カリウムオーリチオシアネート、硫化金、金セレナイド、あるいは米国特許第２，４４８，０６０号、英国特許第６１８，０６１号などに記載されている化合物を好ましく用いることができる。
【００８３】
還元増感法の具体的な化合物としてはアスコルビン酸、二酸化チオ尿素の他に例えば、塩化第一スズ、アミノイミノメタンスルフィン酸、ヒドラジン誘導体、ボラン化合物、シラン化合物、ポリアミン化合物等を用いることができる。また、乳剤のｐＨを７以上またはｐＡｇを８．３以下に保持して熟成することにより還元増感することができる。また、粒子形成中に銀イオンのシングルアディション部分を導入することにより還元増感することができる。
【００８４】
本発明に係る有機銀塩は還元可能な銀源であり、還元可能な銀イオン源を含有する有機酸である。本発明において用いられる有機酸としては、脂肪族カルボン酸、炭素環式カルボン酸、複素環式カルボン酸、複素環式化合物等があるが、特に長鎖（１０〜３０、好ましくは１５〜２５の炭素原子数）の脂肪族カルボン酸及び含窒素複素環を有する複素環式カルボン酸等が好ましく用いられる。また、配位子が４．０〜１０．０の銀イオンに対する総安定定数を有する有機銀塩錯体も有用である。
【００８５】
本発明に係る有機銀塩の感光材料中の含有量としては、３ｇ／ｍ²以下が好ましく、更に好ましくは２ｇ／ｍ²以下であり、特に好ましくは０．２〜２ｇ／ｍ²である。
【００８６】
本発明に係る有機酸銀塩の例としては、Ｒｅｓｅａｒｃｈ Ｄｉｓｃｌｏｓｕｒｅ第１７０２９及び２９９６３に記載されており、次のものがある：脂肪酸の銀塩（例えば、没食子酸、シュウ酸、ベヘン酸、アラキジン酸、ステアリン酸、パルミチン酸、ラウリン酸等の銀塩）；銀のカルボキシアルキルチオ尿素塩（例えば、１−（３−カルボキシプロピル）チオ尿素、１−（３−カルボキシプロピル）−３，３−ジメチルチオ尿素等）；アルデヒドとヒドロキシ置換芳香族カルボン酸との重合反応生成物の銀錯体（例えば、アルデヒド類（ホルムアルデヒド、アセトアルデヒド、ブチルアルデヒド等）とヒドロキシ置換芳香族カルボン酸類（例えば、サリチル酸、安息香酸、３，５−ジヒドロキシ安息香酸、５，５−チオジサリチル酸等）との重合反応生成物の銀錯体等）、チオン類の銀塩または錯体（例えば、３−（２−カルボキシエチル）−４−ヒドロキシメチル−４−チアゾリン−２−チオン、及び３−カルボキシメチル−４−チアゾリン−２−チオン）、イミダゾール、ピラゾール、ウラゾール、１，２，４−チアゾール及び１Ｈ−テトラゾール、３−アミノ−５−ベンジルチオ−１，２，４−トリアゾール及びベンゾトリアゾールから選択される窒素酸と銀との錯体また塩；サッカリン、５−クロロサリチルアルドキシム等の銀塩；及びメルカプタン誘導体の銀塩。上記記載の有機銀塩の中でも、脂肪酸の銀塩が好ましく用いられ、更に好ましく用いられるのは、ベヘン酸銀、アラキジン酸銀およびステアリン酸銀である。
【００８７】
本発明に係る水系有機銀塩の分散物は、硝酸銀と有機酸アルカリ金属塩を混合することにより得られるが、有機銀塩生成時に硝酸銀とハロゲン化銀を同時に添加、混合する同時混合法を用いて製造されるのが好ましい。
【００８８】
例えば、有機酸にアルカリ金属水酸化物（例えば、水酸化ナトリウム、水酸化カリウムなど）を加えて有機酸アルカリ金属塩ソープ（例えば、ベヘン酸ナトリウム、アラキジン酸ナトリウムなど）を作製した後に、コントロールダブルジェット法を用いて、硝酸銀とハロゲン化銀を同時に添加、混合して本発明に係る水系有機銀塩分散物を作製する事が出来る。
【００８９】
更に、有機酸のアルカリ金属塩、硝酸銀及びハロゲン化銀を各々、同時に添加、混合するいわゆるコントロールトリプルジェット法を用いて本発明に係る水系有機銀塩分散物を作製することができる。
【００９０】
本発明においては、生産工程上の簡便性の観点からは、上記のコントロールダブルジェット法を用いた水系有機銀塩分散物の製造方法が好ましく用いられる。また、高感度の熱現像感光材料を製造する観点からは、上記のコントロールトリプルジェット法を用いた水系有機銀塩分散物の製造方法が好ましく用いられる。
【００９１】
本発明の熱現像感光材料には還元剤を内蔵させることが好ましい。好適な還元剤の例は、米国特許第３，７７０，４４８号、同第３，７７３，５１２号、同第３，５９３，８６３号、及びＲｅｓｅａｒｃｈ Ｄｉｓｃｌｏｓｕｒｅ第１７０２９及び２９９６３に記載されており、次のものがある。アミノヒドロキシシクロアルケノン化合物（例えば、２−ヒドロキシピペリジノ−２−シクロヘキセノン）；還元剤の前駆体としてアミノリダクトン類（ｒｅｄｕｃｔｏｎｅｓ）エステル（例えば、ピペリジノヘキソースリダクトンモノアセテート）；Ｎ−ヒドロキシ尿素誘導体（例えば、Ｎ−ｐ−メチルフェニル−Ｎ−ヒドロキシ尿素）；アルデヒドまたはケトンのヒドラゾン類（例えば、アントラセンアルデヒドフェニルヒドラゾン）；ホスファーアミドフェノール類；ホスファーアミドアニリン類；ポリヒドロキシベンゼン類（例えば、ヒドロキノン、ｔ−ブチル−ヒドロキノン、イソプロピルヒドロキノン及び（２，５−ジヒドロキシ−フェニル）メチルスルホン）；スルホヒドロキサム酸類（例えば、ベンゼンスルホヒドロキサム酸）；スルホンアミドアニリン類（例えば、４−（Ｎ−メタンスルホンアミド）アニリン）；２−テトラゾリルチオヒドロキノン類（例えば、２−メチル−５−（１−フェニル−５−テトラゾリルチオ）ヒドロキノン）；テトラヒドロキノキサリン類（例えば、１，２，３，４−テトラヒドロキノキサリン）；アミドオキシム類（例えば、フェニルアミドオキシム、２−チエニル−アミドオキシム、ｐ−フェノキシ−フェニルアミドキシム等）、；アジン類（例えば、脂肪族カルボン酸アリールヒドラザイド類とアスコルビン酸の組み合わせ）；ポリヒドロキシベンゼンとヒドロキシルアミンの組み合わせ、リダクトン及び／またはヒドラジン；ヒドロキサム酸類；アジン類とスルホンアミドフェノール類の組み合わせ；α−シアノフェニル酢酸誘導体；ビス−β−ナフトールと１，３−ジヒドロキシベンゼン誘導体の組み合わせ；５−ピラゾロン類；スルホンアミドフェノール還元剤；２−フェニルインダン−１，３−ジオン等；クロマン；１，４−ジヒドロピリジン類（例えば、２，６−ジメトキシ−３，５−ジカルボエトキシ−１，４−ジヒドロピリジン）；ビスフェノール類（例えば、ビス（２−ヒドロキシ−３−ｔ−ブチル−５−メチルフェニル）メタン、ビス（６−ヒドロキシ−ｍ−トリ）メシトール（ｍｅｓｉｔｏｌ）、２，２−ビス（４−ヒドロキシ−３−メチルフェニル）プロパン、４，５−エチリデン−ビス（２−ｔ−ブチル−６−メチル）フェノール）、紫外線感応性アスコルビン酸誘導体及び３−ピラゾリドン類。中でも特に好ましい還元剤はヒンダードフェノール類である。ヒンダードフェノール類としては下記一般式（Ａ）で表される化合物が挙げられる。
【００９２】
【化１４】

【００９３】
式中、Ｒは水素原子または炭素原子数１〜１０のアルキル基（例えば、ブチル基、２，４，４−トリメチルペンチル基等）を表し、Ｒ′及びＲ″は炭素原子数１〜５のアルキル基（例えば、メチル基、エチル基、ｔ−ブチル基等）を表す。
【００９４】
一般式（Ａ）で表される化合物の具体例を以下に示す。ただし、本発明は、これらに限定されない。
【００９５】
【化１５】

【００９６】
【化１６】

【００９７】
前記一般式（Ａ）で表される化合物を始めとする還元剤の使用量は好ましくは銀１モル当り１×１０^-2〜１０モル、特に１×１０^-2〜１．５モルである。
【００９８】
本発明の熱現像感光材料中にはカブリ防止剤が含まれて良い。有効なカブリ防止剤として知られているものは水銀イオンであり、感光材料中にカブリ防止剤として水銀化合物を使用することについては、例えば米国特許第３，５８９，９０３号に開示されている。しかし、水銀化合物は環境的に好ましくないので、例えば米国特許第４，５４６，０７５号及び同第４，４５２，８８５号及び特開昭５９−５７２３４号に開示されている様な非水銀カブリ防止剤が本発明においては好ましく用いられる。
【００９９】
特に好ましい非水銀カブリ防止剤としては、米国特許第３，８７４，９４６号及び同第４，７５６，９９９号に開示されているような化合物、−Ｃ（Ｘ₁）（Ｘ₂）（Ｘ₃）（ここでＸ₁及びＸ₂はハロゲン原子を表し、Ｘ₃は水素またはハロゲン原子を表す）で表される置換基を１以上備えたヘテロ環状化合物が挙げられる。
【０１００】
また、その他に好適なカブリ防止剤としては、特開平９−２８８３２８号の段落番号〔００３０〕〜〔００３６〕に記載されている化合物、同９−９０５５０号の段落番号〔００６２〕〜〔００６３〕に記載されている化合物、米国特許第５，０２８，５２３号及び欧州特許第６００，５８７号、同第６０５，９８１号、同第６３１，１７６号等に開示されている化合物等を用いることが出来る。
【０１０１】
本発明の熱現像感光材料には、現像後の銀色調を改良する目的で色調剤を添加することが好ましい。好適な色調剤の例はＲｅｓｅａｒｃｈ Ｄｉｓｃｌｏｓｕｒｅ第１７０２９号に開示されており、次のものがある。
【０１０２】
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、ベンゾオキサジン、ナルトキサジン誘導体；ベンゾオキサジン−２，４−ジオン類（例えば、１，３−ベンゾオキサジン−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またはフタラジンである。
【０１０３】
本発明の熱現像感光材料には、例えば特開昭６３−１５９８４１号、同６０−１４０３３５号、同６３−２３１４３７号、同６３−２５９６５１号、同６３−３０４２４２号、同６３−１５２４５号、米国特許第４，６３９，４１４号、同第４，７４０，４５５号、同第４，７４１，９６６号、同第４，７５１，１７５号、同第４，８３５，０９６号に記載された増感色素が使用できる。
【０１０４】
本発明に使用される有用な増感色素は例えばＲｅｓｅａｒｃｈ Ｄｉｓｃｌｏｓｕｒｅ Ｉｔｅｍ１７６４３IV−Ａ項（１９７８年１２月ｐ．２３）、同Ｉｔｅｍ１８４３１（１９７９年８月ｐ．４３７）等に記載もしくは引用された文献に記載されている。特に各種スキャナー光源の分光特性に適した分光感度を有する増感色素を有利に選択することができる。例えば特開平９−３４０７８号、同９−５４４０９号、同９−８０６７９号記載の化合物が好ましく用いられる。
【０１０５】
本発明には現像を抑制あるいは促進させ現像を制御するため、分光増感効率を向上させるため、現像前後の保存性を向上させるためなどにメルカプト化合物、ジスルフィド化合物、チオン化合物を含有させることができる。
【０１０６】
本発明にメルカプタン誘導体を使用する場合、いかなる構造のものでも良いが、Ａｒ−ＳＭ、Ａｒ−Ｓ−Ｓ−Ａｒで表されるものが好ましい。式中、Ｍは水素原子またはアルカリ金属原子であり、Ａｒは１個以上の窒素、イオウ、酸素、セレンまたはテルル原子を有する芳香環または縮合芳香環を表す。
【０１０７】
該芳香環としては、芳香族炭素環及び複素芳香族環が用いられるが、本発明においては複素芳香族環が好ましく用いられる。複素芳香族環としては、例えばベンゾイミダゾール、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、ベンゾオキサゾール、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、チアジアゾール、テトラゾール、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、キノリンまたはキナゾリノンである。この複素芳香族環は、例えば、ハロゲン原子（例えば、ＢｒおよびＣｌ等）、ヒドロキシル基、アミノ基、カルボキシ基、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）およびアルコキシル基（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）からなる置換基群から選択されるものを有してもよい。メルカプト置換複素芳香族化合物としては、２−メルカプトベンゾイミダゾール、２−メルカプトベンゾオキサゾール、２−メルカプトベンゾチアゾール、２−メルカプト−５−メチルベンゾチアゾール、３−メルカプト−１，２，４−トリアゾール、２−メルカプトキノリン、８−メルカプトプリン、２，３，５，６−テトラクロロ−４−ピリジンチオール、４−ヒドロキシ−２−メルカプトピリミジン、２−メルカプト−４−フェニルオキサゾールなどが挙げられるが、本発明はこれらに限定されない。
【０１０８】
本発明においては、感光性層側にマット剤を含有することが好ましく、熱現像後の画像の傷つき防止のためには感光材料の表面にマット剤を配することが好ましく、そのマット剤を乳剤層側の全バインダに対し、質量比で０．５〜３０％含有することが好ましい。
【０１０９】
本発明に用いられるマット剤の材質は有機物及び無機物のいずれでもよい。
例えば、無機物としては、スイス特許第３３０，１５８号等に記載のシリカ、仏国特許第１，２９６，９９５号等に記載のガラス粉、英国特許第１，１７３，１８１号等に記載のアルカリ土類金属またはカドミウム、亜鉛等の炭酸塩等をマット剤として用いることができる。有機物としては、米国特許第２，３２２，０３７号等に記載の澱粉、ベルギー特許第６２５，４５１号や英国特許第９８１，１９８号等に記載された澱粉誘導体、特公昭４４−３６４３号等に記載のポリビニルアルコール、スイス特許第３３０，１５８号等に記載のポリスチレン或いはポリメタクリレート、米国特許第３，０７９，２５７号等に記載のポリアクリロニトリル、同第３，０２２，１６９号等に記載されたポリカーボネートの様な有機マット剤を用いることができる。
【０１１０】
マット剤の形状は、定形、不定形どちらでも良いが、好ましくは定形で、球形が好ましく用いられる。マット剤の大きさはマット剤の体積を球形に換算したときの直径で表される。本発明においてマット剤の粒径とはこの球形換算した直径のことを示すものとする。
【０１１１】
本発明に用いられるマット剤は、平均粒径が０．５μｍ〜１０μｍであることが好ましく、更に好ましくは１．０μｍ〜８．０μｍである。又、粒子サイズ分布の変動係数としては、５０％以下であることが好ましく、更に好ましくは４０％以下であり、特に好ましくは３０％以下となるマット剤である。
【０１１２】
ここで、粒子サイズ分布の変動係数は、下記の式で表される値である。
（粒径の標準偏差）／（粒径の平均値）×１００
本発明に用いられるマット剤は任意の構成層中に含むことができるが、本発明の目的を達成するためには好ましくは感光性層以外の構成層であり、更に好ましくは支持体から見て最も外側の層である。
【０１１３】
本発明に用いられるマット剤の添加方法は、予め塗布液中に分散させて塗布する方法であってもよいし、塗布液を塗布した後、乾燥が終了する以前にマット剤を噴霧する方法を用いてもよい。また複数の種類のマット剤を添加する場合は、両方の方法を併用してもよい。
【０１１４】
本発明においては帯電性を改良するために金属酸化物および／または導電性ポリマーなどの導電性化合物を構成層中に含ませることができる。これらはいずれの層に含有させてもよいが、好ましくは下引層、バッキング層、感光性層と下引の間の層などに含まれる。
【０１１５】
本発明においては米国特許第５，２４４，７７３号カラム１４〜２０に記載された導電性化合物が好ましく用いられる。
【０１１６】
各種の添加剤は感光性層、非感光性層、またはその他の構成層のいずれに添加しても良い。本発明の熱現像感光材料には上述した以外に例えば、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。これらの添加剤及び上述したその他の添加剤はＲｅｓｅａｒｃｈ Ｄｉｓｃｌｏｓｕｒｅ Ｉｔｅｍ１７０２９（１９７８年６月、ｐ．９〜１５）に記載されている化合物を好ましく用いることができる。
【０１１７】
本発明の熱現像感光材料に好適なバインダは透明または半透明で、一般に無色であり、天然ポリマー合成樹脂やポリマー及びコポリマー、その他フィルムを形成する媒体、例えば：ゼラチン、アラビアゴム、ポリ（ビニルアルコール）、ヒドロキシエチルセルロース、セルロースアセテート、セルロースアセテートブチレート、ポリ（ビニルピロリドン）、カゼイン、デンプン、ポリ（アクリル酸）、ポリ（メチルメタクリル酸）、ポリ（塩化ビニル）、ポリ（メタクリル酸）、コポリ（スチレン−無水マレイン酸）、コポリ（スチレン−アクリロニトリル）、コポリ（スチレン−ブタジエン）、ポリ（ビニルアセタール）類（例えば、ポリ（ビニルホルマール）及びポリ（ビニルブチラール））、ポリ（エステル）類、ポリ（ウレタン）類、フェノキシ樹脂、ポリ（塩化ビニリデン）、ポリ（エポキシド）類、ポリ（カーボネート）類、ポリ（ビニルアセテート）、セルロースエステル類、ポリ（アミド）類がある。親水性でも非親水性でもよい。また感光材料の表面を保護したり擦り傷を防止するために、感光性層の外側に非感光性層を有することができる。これらの非感光性層に用いられるバインダは感光性層に用いられるバインダと同じ種類でも異なった種類でもよい。
【０１１８】
本発明においては、熱現像の速度を速めるために感光性層のバインダ量が１．５〜１０ｇ／ｍ²であることが好ましく、更に好ましくは１．７〜８ｇ／ｍ²である。
【０１１９】
本発明に係る支持体は現像処理後の画像の変形を防ぐためにプラスチックフィルム（例えば、ポリエチレンテレフタレート、ポリカーボネート、ポリイミド、ナイロン、セルローストリアセテート、ポリエチレンナフタレート）であることが好ましい。
【０１２０】
その中でも好ましい支持体としては、ポリエチレンテレフタレート（以下ＰＥＴと略す）及びシンジオタクチック構造を有するスチレン系重合体を含むプラスチック（以下ＳＰＳと略す）の支持体が挙げられる。支持体の厚みとしては５０〜３００μｍ程度、好ましくは７０〜１８０μｍである。
【０１２１】
また熱処理したプラスチック支持体を用いることもできる。採用するプラスチックとしては、前記のプラスチックが挙げられる。支持体の熱処理とはこれらの支持体を製膜後、感光性層が塗布されるまでの間に、支持体のガラス転移点より３０℃以上高い温度で、好ましくは３５℃以上高い温度で、更に好ましくは４０℃以上高い温度で加熱することがよい。但し、支持体の融点を超えた温度で加熱しては本発明の効果は得られない。
【０１２２】
次に用いられるプラスチックについて説明する。
ＰＥＴはポリエステルの成分が全てポリエチレンテレフタレートからなるものであるが、ポリエチレンテレフタレート以外に、酸成分としてテレフタル酸、ナフタレン−２，６−ジカルボン酸、イソフタル酸、ブチレンジカルボン酸、５−ナトリウムスルホイソフタル酸、アジピン酸等と、グリコール成分としてエチレングリコール、プロピレングリコール、ブタンジオール、シクロヘキサンジメタノール等との変性ポリエステル成分が全ポリエステルの１０モル％以下含まれたポリエステルであってもよい。
【０１２３】
ＳＰＳは通常のポリスチレン（アタクチックポリスチレン）と異なり立体的に規則性を有したポリスチレンである。ＳＰＳの規則的な立体規則性構造部分をラセモ連鎖といい、２連鎖、３連鎖、５連鎖、あるいはそれ以上と規則的な部分がより多くあることが好ましく、本発明において、ラセモ連鎖は、２連鎖で８５％以上、３連鎖で７５％以上、５連鎖で５０％以上、それ以上の連鎖で３０％以上であることが好ましい。ＳＰＳの重合は特開平３−１３１８４３号明細書記載の方法に準じて行うことが出来る。
【０１２４】
本発明に用いられる支持体の製膜方法及び下引製造方法は公知の方法を用いることができるが、好ましくは、特開平９−５００９４号の段落〔００３０〕〜〔００７０〕に記載された方法を用いることである。
【０１２５】
本発明の熱現像感光材料は、熱現像処理にて写真画像を形成するもので、還元可能な銀源（有機銀塩）、感光性ハロゲン化銀、還元剤及び必要に応じて銀の色調を抑制する色調剤を通常（有機）バインダマトリックス中に分散した状態で含有している熱現像感光材料であることが好ましい。本発明の熱現像感光材料は常温で安定であるが、露光後高温（例えば、８０℃〜１４０℃）に加熱することで現像される。加熱することで有機銀塩（酸化剤として機能する）と還元剤との間の酸化還元反応を通じて銀を生成する。この酸化還元反応は露光でハロゲン化銀に発生した潜像の触媒作用によって促進される。露光領域中の有機銀塩の反応によって生成した銀は黒色画像を提供し、これは非露光領域と対照をなし、画像の形成がなされる。この反応過程は、外部から水等の処理液を供給することなしで進行する。
【０１２６】
本発明の熱現像感光材料は支持体上に少なくとも一層の感光性層を有している。支持体の上に感光性層のみを形成しても良いが、感光性層の上に少なくとも１層の非感光性層を形成することが好ましい。感光性層に通過する光の量または波長分布を制御するために感光性層と同じ側にフィルター染料層および／または反対側にアンチハレーション染料層、いわゆるバッキング層を形成しても良いし、感光性層に染料または顔料を含ませても良い。用いられる染料としては所望の波長範囲で目的の吸収を有するものであればいかなる化合物でも良いが、例えば特開昭５９−６４８１号、特開昭５９−１８２４３６号、米国特許第４，２７１，２６３号、米国特許第４，５９４，３１２号、欧州特許公開５３３，００８号、欧州特許公開６５２，４７３号、特開平２−２１６１４０号、特開平４−３４８３３９号、特開平７−１９１４３２号、特開平７−３０１８９０号などの記載の化合物が好ましく用いられる。
【０１２７】
またこれらの非感光性層には前記のバインダやマット剤を含有することが好ましく、さらにポリシロキサン化合物やワックスや流動パラフィンのようなスベリ剤を含有してもよい。
【０１２８】
感光性層は複数層にしても良く、また階調の調節のため感度を高感層／低感層または低感層／高感層にしても良い。
【０１２９】
熱現像感光材料の詳細は前述のとおり例えば米国特許第３，１５２，９０４号、同第３，４５７，０７５号、及びＤ．モーガン（Ｍｏｒｇａｎ）とＢ．シェリー（Ｓｈｅｌｙ）による米国特許第３，１５２，９０４号、同第３，４５７，０７５号または、Ｄ．Ｈクロスタベール（Ｋｌｏｓｔｅｒｂｏｅｒ）による「熱によって処理される銀システム（Ｔｈｅｒｍａｌｌｙ Ｐｒｏｃｅｓｓｅｄ Ｓｉｌｖｅｒ Ｓｙｓｔｅｍｓ）」、イメージング・プロセッシーズ・アンド・マテリアルズ（Ｉｍａｇｉｎｇ Ｐｒｏｃｅｓｓｅｓ ａｎｄ Ｍａｔｅｒｉａｌｓ）Ｎｅｂｌｅｔｔｅ 第８版、スタージ（Ｓｔｕｒｇｅ）、Ｖ．ウォールワース（Ｗａｌｗｏｒｔｈ）、Ａ．シェップ（Ｓｈｅｐｐ）編集、第２７９頁、１９８９年等に開示されている。
【０１３０】
その中でも本発明においては、感光材料を８０〜１４０℃で熱現像することで画像を形成させ、定着を行わないことが特徴である。そのため、未露光部に残ったハロゲン化銀や有機銀塩は除去されずにそのまま感光材料中に残る。
【０１３１】
本発明においては、熱現像処理した後の、４００ｎｍにおける支持体を含んだ感光材料の光学透過濃度が０．２以下であることが好ましい。光学透過濃度の更に好ましい値は０．０２以上０．２以下である。
【０１３２】
【実施例】
以下、実施例で本発明を詳細に説明するが、本発明はこれらに限定されない。
【０１３３】
実施例１
《写真用支持体の作製》
濃度０．１７０（コニカ（株）製デンシトメータＰＤＡ−６５にて測定）に青色着色した、厚み１７５μｍのＰＥＴフィルムの両面に８Ｗ／ｍ²・分のコロナ放電処理を施した。
【０１３４】
《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（硝酸銀と等モル量）及び塩化イリジウムを銀１モル当たり１×１０^-4モルを含む水溶液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。
【０１３５】
《粉末有機銀塩の調製》
４７２０ｍｌの純水にベヘン酸１１１．４ｇ、アラキジン酸８３．８ｇ、ステアリン酸５４．９ｇを８０℃で溶解した。次に高速で攪拌しながら１．５Ｍ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℃に冷却して有機酸ナトリウム溶液を得た。上記の有機酸ナトリウム溶液の温度を５５℃に保ったまま、上記ハロゲン化銀乳剤（銀０．０３８モルを含む）と純水４５０ｍｌを添加し５分間攪拌した。次に１Ｍの硝酸銀溶液７６０．６ｍｌを２分間かけて添加し、さらに２０分攪拌し、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℃にて質量減がなくなるまで温風乾燥を行い、粉末有機銀塩を得た。
【０１３６】
《感光性乳剤分散液の調製》
ポリビニルブチラール粉末（Ｍｏｎｓａｎｔｏ社 Ｂｕｔｖａｒ Ｂ−７９）１４．５７ｇをメチルエチルケトン１４５７ｇに溶解し、ディゾルバー型ホモジナイザにて攪拌しながら粉末有機銀塩５００ｇを徐々に添加して十分に混合した。その後１ｍｍ径のＺｒビーズ（東レ製）を８０％充填したメディア型分散機（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。
【０１３７】
《感光層塗布液の調製》
前記感光性乳剤（５００ｇ）およびＭＥＫ（メチルエチルケトン）１００ｇを攪拌しながら２１℃に保温した。カブリ防止剤１（０．２０ｇ）を加え、１時間攪拌した。さらに臭化カルシウム（１０％メタノール溶液３．２５ｍｌ）を添加して３０分攪拌した。次に増感色素１、表１に示すように一般式（１）もしくは一般式（１）＋（２）もしくは一般式（１）＋（３）、および強色増感剤の混合溶液（混合比率１：２５０〜４５０：２０、増感色素で０．１％ＭＥＫ溶液、７ｍｌ）を添加して１時間攪拌した後に温度を１３℃まで降温してさらに３０分攪拌し、１３℃に保温したまま、ポリビニルブチラール４８ｇを添加して充分溶解してから、以下の添加物を添加した。
【０１３８】
各化合物を以下の添加量で添加する。
Ａ−３（還元剤） １５ｇ
デスモデュＮ３３００（モーベイ社、脂肪族イソシアネート）１．１０ｇ
プリントアウト防止剤 １．５５ｇ
フタラジン １．５ｇ
テトラクロルフタル酸 ０．５ｇ
４−メチルフタル酸 ０．５ｇ
【０１３９】
【化１７】

【０１４０】
【化１８】

【０１４１】
感光層塗布液を調製後、１３℃に保温して以下に示す方法で塗布を行った。
支持体上に以下の各層を順次形成し、試料を作製した。尚、乾燥は各々７５℃、５分間で行った。
【０１４２】
《バック面側塗布》
（バック面塗布液の調製）
メチルエチルケトン８３０ｇに攪拌しながら、セルロースアセテートブチレート（ＥａｓｔｍａｎＣｈｅｍｉｃａｌ社、ＣＡＢ３８１−２０）８４．２ｇ、ポリエステル樹脂（Ｂｏｓｔｉｃ社、ＶｉｔｅｌＰＥ２２００Ｂ）４．５ｇを添加し溶解した。溶解した液に、０．３０ｇの赤外染料１を添加し、さらにメタノール４３．２ｇに溶解したＦ系活性剤（旭硝子社、サーフロンＫＨ４０）４．５ｇとＦ系活性剤（大日本インク社、メガファッグＦ１２０Ｋ）２．３ｇを添加して、溶解するまで十分に攪拌を行った。最後に、メチルエチルケトンに１質量％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（Ｗ．Ｒ．Ｇｒａｃｅ社、シロイド６４×６０００）を７５ｇ添加、攪拌しバック面の塗布液を調製した。
（バック面の塗布）
このように調製した、バック面塗布液を、乾燥膜厚が３．５μｍになるように押し出しコーターにて塗布乾燥を行った。乾燥温度１００℃、露点温度１０℃の乾燥風を用いて５分間かけて乾燥した。
【０１４３】
前記感光層塗布液と表面保護層塗布液をエクストリュージョンコーターを用いて同時重層塗布を行った。感光層は塗布銀量２．０ｇ／ｍ²、表面保護層は乾燥膜厚で２．５μｍになる様に毎分２０ｍの速度で塗布した。その後、乾燥温度７５℃、露点温度１０℃の乾燥風を用いて、１０分間乾燥を行った。
【０１４４】
《感光層面側塗布》
感光層以下の組成の液を塗布銀量が２．０ｇ／ｍ²、バインダーとしてのポリビニルブチラールを８．５ｇ／ｍ²になるように前記感光層塗布液を塗布した。
【０１４５】

《露光及び現像処理》
上記のように作製した感光材料の乳剤面側から、高周波重畳にて波長８００ｎｍ〜８２０ｎｍの縦マルチモード化された半導体レーザを露光源とした露光機によりレーザ走査による露光を与えた。この際に、感光材料の露光面と露光レーザ光の角度を７５度として画像を形成した（なお、当該角度を９０度とした場合に比べムラが少なく、かつ予想外に鮮鋭性等が良好な画像が得られた。）。
【０１４６】
その後ヒートドラムを有する自動現像機を用いて感光材料の保護層とドラム表面が接触するようにして、１２３℃で１６．５秒熱現像処理した。その際、露光及び現像は２３℃、５０％ＲＨに調湿した部屋で行った。得られた画像の評価を濃度計により行った。測定の結果は、感度（Ｓ）（未露光部分よりも１．０高い濃度を与える露光量の比の逆数）およびカブリ（ｆｏｇ）で評価し、表１中の感光材料試料１の感度を１００とする相対値で示した。
【０１４７】
《フィルムの保存性の評価》
上記試料２枚のうち１枚を塗布後直ちに露光、現像し、もう１枚は２５℃、５５％ＲＨで３日間遮光保存した後露光、現像し、両者の感度及びカブリ部分の濃度を測定した。得られた結果を表１に示す。
【０１４８】
感度の増加（ΔＳ）＝遮光保存後現像の相対感度−即現像の相対感度
カブリの増加（Δｆｏｇ）＝遮光保存後現像のカブリ−即現像のカブリ
上記記載の感度の増加、カブリの増加から、熱現像感光材料の保存性を評価した。ここで露光、現像、評価法は上記の通りである。
【０１４９】
【表１】

【０１５０】
表１から、比較の試料に比べて、本発明の試料は低カブリ、高感度であり、且つ、保存性が向上していることが明らかである。本発明の領域において、低カブリかつ高感度な初期性能を有し、かつ経時保存性に優れた熱現像感光材料が得られた。
【０１５１】
実施例２
実施例１の表１に示されている熱現像感光材料１〜１１を実施例１に記載と同様にして露光、現像処理し、次いで、直射日光のあたるガラス窓の内側に張り付け１ヶ月間放置した後の画像の様子を下記のような評価基準を適用して画像の耐光性を目視評価し、試料１２〜２２として各々示した。得られた結果を表２に示す。
【０１５２】
《光照射時の画像保存性の評価基準》
◎：ほとんど変化が無い
○：僅かに色調変化があるが、実用上問題ない
△：画像部変色があるが実用的に許容される
×：Ｄｍｉｎが変色し濃度が上がり、実用不可
尚、本発明においては、Ｄｍｉｎは下記一般式のように定義する。
【０１５３】
Ｄｍｉｎ＝未露光部の濃度＋ベース（支持体）濃度
【０１５４】
【表２】

【０１５５】
表２から、比較の試料に比べて本発明の試料は画像の耐光性が向上していることが明らかである。
【０１５６】
実施例３
《下引済み写真用支持体の作製》
（ＰＥＴ下引済み写真用支持体の作製）
市販の２軸延伸熱固定済みの厚さ１７５μｍ、光学濃度で０．１７０（コニカ社製デンシトメータＰＤＡ−６５にて測定）に青色着色したＰＥＴ（ポリエチレンテレフタレート）フィルムの両面に８Ｗ／ｍ²・分のコロナ放電処理を施し、一方の面に下記下引塗布液ａ−１を乾燥膜厚０．８μｍになるように塗設、乾燥させて下引層Ａ−１とし、又、反対側の面に下記下引塗布液ｂ−１を乾燥膜厚０．８μｍになるように塗設、乾燥させて下引層Ｂ−１とした。
【０１５７】

引き続き、下引層Ａ−１及び下引層Ｂ−１の表面に８Ｗ／ｍ²・分のコロナ放電を施し、下引層Ａ−１の上には、下記下引上層塗布液ａ−２を乾燥膜厚０．１μｍになる様に下引上層Ａ−２として、下引層Ｂ−１の上には、下記下引上層塗布液ｂ−２を乾燥膜厚０．８μｍになる様に帯電防止機能を持つ下引上層Ｂ−２として塗設した。
【０１５８】

【０１５９】
【化１９】

【０１６０】
【化２０】

【０１６１】
（バック面側塗布）
メチルエチルケトン（ＭＥＫ）８３０ｇを攪拌しながら、セルロースアセテートブチレート（Ｅａｓｔｍａｎ Ｃｈｅｍｉｃａｌ社製：ＣＡＢ３８１−２０）８４．２ｇ及びポリエステル樹脂（Ｂｏｓｔｉｃ社製：ＶｉｔｅｌＰＥ２２００Ｂ）４．５ｇを添加し、溶解した。次に、溶解した液に、０．３０ｇの下記赤外染料２を添加し、更にメタノール４３．２ｇに溶解した弗素系活性剤（旭硝子社製：サーフロンＫＨ４０）４．５ｇと弗素系活性剤（大日本インク社製：メガファッグＦ１２０Ｋ）２．３ｇを添加して、溶解するまで十分に攪拌した。最後に、ＭＥＫに１質量％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（Ｗ．Ｒ．Ｇｒａｃｅ社製：シロイド６４×６０００）を７５ｇ添加、攪拌し、バック面側用の塗布液を調製した。
【０１６２】
【化２１】

【０１６３】
このように調製したバック面塗布液を、乾燥膜厚が３．５μｍになるように押出しコーターにて塗布・乾燥を行った。乾燥温度１００℃、露点温度１０℃の乾燥風を用いて５分間かけて乾燥した。
【０１６４】
《感光性ハロゲン化銀乳剤Ａの調製》
（溶液Ａ１）
フェニルカルバモイル化ゼラチン ８８．３ｇ
化合物Ａ（１０％メタノール水溶液） １０ｍｌ
臭化カリウム ０．３２ｇ
水で５４２９ｍｌに仕上げる
（溶液Ｂ１）
０．６７ｍｏｌ／Ｌ硝酸銀水溶液 ２６３５ｍｌ
（溶液Ｃ１）
臭化カリウム ５１．５５ｇ
沃化カリウム １．４７ｇ
水で６６０ｍｌに仕上げる
（溶液Ｄ１）
臭化カリウム １５４．９ｇ
沃化カリウム ４．４１ｇ
塩化イリジウム（１％溶液） ０．９３ｍｌ
水で１９８２ｍｌに仕上げる
（溶液Ｅ１）
０．４ｍｏｌ／Ｌ臭化カリウム水溶液 下記銀電位制御量
（溶液Ｆ１）
水酸化カリウム ０．７１ｇ
水で２０ｍｌに仕上げる
（溶液Ｇ１）
５６％酢酸水溶液 １８．０ｍｌ
（溶液Ｈ１）
無水炭酸ナトリウム １．７２ｇ
水で１５１ｍｌに仕上げる
Ａ：ＨＯ（ＣＨ₂ＣＨ₂Ｏ）_n（ＣＨ（ＣＨ₃）ＣＨ₂Ｏ）₁₇（ＣＨ₂ＣＨ₂Ｏ）_mＨ（ｍ＋ｎ＝５〜７）
特公昭５８−５８２８８号、同５８−５８２８９号に示される混合攪拌機を用いて溶液（Ａ１）に溶液（Ｂ１）の１／４量及び溶液（Ｃ１）の全量を、４５℃、ｐＡｇ８．０９に制御しながら、同時混合法により４分４５秒を要して添加し、核形成を行った。１分後、溶液（Ｆ１）の全量を添加した。この間、ｐＡｇの調整を溶液（Ｅ１）を用いて適宜行った。６分間経過後、溶液（Ｂ１）の３／４量及び溶液（Ｄ１）の全量を、４５℃、ｐＡｇ８．０９に制御しながら同時混合法により１４分１５秒かけて添加した。５分間攪拌した後、４０℃に降温し、溶液（Ｇ１）を全量添加し、ハロゲン化銀乳剤を沈降させた。沈降部分２０００ｍｌを残して上澄み液を取り除き、水を１０リットル加え、攪拌後、再度ハロゲン化銀乳剤を沈降させた。沈降部分１５００ｍｌを残し、上澄み液を取り除き、更に水を１０リットル加え、攪拌後、ハロゲン化銀乳剤を沈降させた。沈降部分１５００ｍｌを残し、上澄み液を取り除いた後、溶液（Ｈ１）を加え、６０℃に昇温し、更に１２０分攪拌した。最後にｐＨが５．８になるように調整し、銀量１モル当たり１１６１ｇになるように水を添加し、感光性ハロゲン化銀乳剤Ａを得た。この乳剤は、平均粒子サイズ０．０５８μｍ、粒子サイズの変動係数１２％、〔１００〕面比率９２％の単分散立方体沃臭化銀粒子であった。
【０１６５】
《粉末有機銀塩Ａの調製》
４７２０ｍｌの純水に、ベヘン酸１３０．８ｇ、アラキジン酸６７．７ｇ、ステアリン酸４３．６ｇ、パルミチン酸２．３ｇを８０℃で溶解した。次に１．５ｍｏｌ／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。
【０１６６】
この脂肪酸ナトリウム溶液の温度を５５℃に保ったまま、４５．３ｇの前記感光性ハロゲン化銀乳剤Ａと純水４５０ｍｌを添加し５分間攪拌した。次に１ｍｏｌ／Ｌの硝酸銀水溶液７０２．６ｍｌを２分間かけて添加し、１０分間攪拌して有機銀塩分散物を得た。その後、得られた有機銀塩分散物を水洗容器に移し、脱イオン水を加えて攪拌後、静置させて有機銀塩分散物を浮上分離させ、下方の水溶性塩類を除去した。その後、排水の電導度が２μＳ／ｃｍになるまで脱イオン水による水洗、排水を繰り返し、遠心脱水を実施した後、得られたケーキ状の有機銀塩を、気流式乾燥機フラッシュジェットドライヤー（セイシン企業社製）を用いて、窒素ガス雰囲気及び乾燥機入り口熱風温度の運転条件により、含水率が０．１％になるまで乾燥して有機銀塩の乾燥済み粉末有機銀塩Ａを得た。尚、有機銀塩組成物の含水率測定には赤外線水分計を使用した。
【０１６７】
《予備分散液Ａの調製》
ポリビニルブチラール粉末（Ｍｏｎｓａｎｔｏ社製：Ｂｕｔｖａｒ Ｂ−７９）１４．５７ｇをＭＥＫ１４５７ｇに溶解し、ＶＭＡ−ＧＥＴＺＭＡＮＮ社製ディゾルバＤＩＳＰＥＲＭＡＴ ＣＡ−４０Ｍ型にて攪拌しながら粉末有機銀塩Ａ５００ｇを徐々に添加し十分に混合することにより予備分散液Ａを調製した。
【０１６８】
《感光性乳剤分散液１の調製》
予備分散液Ａをポンプを用いて、ミル内滞留時間が１．５分間となるように、０．５ｍｍ径のジルコニアビーズ（東レ社製：トレセラム）を内容積の８０％充填したメディア型分散機ＤＩＳＰＥＲＭＡＴ ＳＬ−Ｃ１２ＥＸ型（ＶＭＡ−ＧＥＴＺＭＡＮＮ社製）に供給し、ミル周速８ｍ／ｓにて分散を行うことにより感光性乳剤分散液１を調製した。
【０１６９】
《安定剤液の調製》
１．０ｇの安定剤−１、０．３１ｇの酢酸カリウムをメタノール４．９７ｇに溶解し安定剤液を調製した。
【０１７０】
【化２２】

【０１７１】
《赤外増感色素液Ａの調製》
増感色素１、表２に示すように一般式（１）もしくは一般式（１）＋（２）もしくは一般式（１）＋（３）、および５−メチル−２−メルカプトベンゾイミダゾールの混合溶液（混合比率１：２５０〜４５０：２０、増感色素で０．１％ＭＥＫ溶液、３１．３ｍｌ）を暗所にて溶解し赤外増感色素液Ａを調製した。
【０１７２】
《添加液ａの調製》
現像剤としての１，１−ビス（２−ヒドロキシ−３，５−ジメチルフェニル）−２−メチルプロパンを２７．９８ｇと１．５４ｇの４−メチルフタル酸、０．４８ｇの前記赤外染料１をＭＥＫ１１０ｇに溶解し添加液ａとした。
【０１７３】
《添加液ｂの調製》
１．７８ｇずつのカブリ防止剤１及びプリントアウト防止剤、更に３．４３ｇのフタラジンをＭＥＫ４０．９ｇに溶解し添加液ｂとした。
【０１７４】
《添加液ｃの調製》
５．０ｇの省銀化剤Ｈ−９４をＭＥＫ４５．０ｇに溶解し添加液ｃとした。
【０１７５】
【化２３】

【０１７６】
《感光層塗布液Ａの調製》
不活性気体雰囲気下（窒素９７％）において、前記感光性乳剤分散液１を５０ｇ及びＭＥＫ１５．１１ｇを撹拌しながら２１℃に保温し、化学増感剤Ｓ−５（０．５％メタノール溶液）１０００μｌを加え、２分後にカブリ防止剤１（１０％メタノール溶液）３９０μｌを加え、１時間撹拌した。更に臭化カルシウム（１０％メタノール溶液）４９４μｌを添加して１０分撹拌した後に上記化学増感剤の１／２０モル相当の金増感剤Ａｕ−５を添加し、更に２０分攪拌した。続いて、安定剤液１６７ｍｌを添加して１０分間攪拌した後、１．３２ｇの前記赤外増感色素液Ａを添加して１時間攪拌した。その後、温度を１３℃まで降温して更に３０分攪拌した。１３℃に保温したまま、ポリビニルブチラール（Ｂｕｔｖａｒ Ｂ−７９：前出）１３．３１ｇを添加して３０分撹拌した後、テトラクロロフタル酸（９．４％ＭＥＫ溶液）１．０８４ｇを添加して１５分間撹拌した。更に撹拌を続けながら、１２．４３ｇの添加液ａ、１．６ｍｌのイソシアネート化合物（モーベイ社製、Ｄｅｓｍｏｄｕｒ Ｎ３３００）の１０％ＭＥＫ溶液、４．２７ｇの添加液ｂを順次添加し撹拌することにより感光層塗布液Ａを得た。
【０１７７】
【化２４】

【０１７８】
《感光層塗布液Ｂの調製》
不活性気体雰囲気下（窒素９７％）において、前記感光性乳剤分散液１を５０ｇ及びＭＥＫ１５．１１ｇを撹拌しながら２１℃に保温し、化学増感剤Ｓ−５（０．５％メタノール溶液）１０００μｌを加え、２分後にカブリ防止剤１（１０％メタノール溶液）３９０μｌを加え、１時間撹拌した。更に臭化カルシウム（１０％メタノール溶液）４９４μｌを添加して１０分撹拌した後に上記化学増感剤の１／２０モル相当の金増感剤Ａｕ−５を添加し、更に２０分撹拌した。続いて、安定剤液１６７ｍｌを添加して１０分間撹拌した後、１．３２ｇの前記赤外増感色素液Ａを添加して１時間撹拌した。その後、温度を１３℃まで降温して更に３０分撹拌した。１３℃に保温したまま、ポリビニルブチラール（Ｂｕｔｖａｒ Ｂ−７９；前出）１３．３１ｇを添加して３０分撹拌した後、テトラクロロフタル酸（９．４％ＭＥＫ溶液）１．０８４ｇを添加して１５分間撹拌した。更に撹拌を続けながら、１２．４３ｇの添加液ａ、１．６ｍｌのイソシアネート化合物（モーベイ社製、Ｄｅｓｍｏｄｕｒ Ｎ３３００）１０％ＭＥＫ溶液、４．２７ｇの添加液ｂ、１０．０ｇの添加液ｃを順次添加し攪拌することにより感光層塗布液Ｂを得た。
【０１７９】
《マット剤分散液の調製》
セルロースアセテートブチレート（Ｅａｓｔｍａｎ Ｃｈｅｍｉｃａｌ社製：ＣＡＢ１７１−１５）７．５ｇをＭＥＫ４２．５ｇに溶解し、その中に、炭酸カルシウム（Ｓｐｅｃｉａｌｉｔｙ Ｍｉｎｅｒａｌｓ社製：Ｓｕｐｅｒ−Ｐｆｌｅｘ２００）５ｇを添加し、ディゾルバ型ホモジナイザにて８０００ｒｐｍで３０ｍｉｎ分散しマット剤分散液を調製した。
【０１８０】
《表面保護層塗布液の調製》
ＭＥＫ（メチルエチルケトン）８６５ｇを攪拌しながら、セルロースアセテートブチレート（ＣＡＢ１７１−１５：前出）を９６ｇ、ポリメチルメタクリル酸（ローム＆ハース社社製：パラロイドＡ−２１）を４．５ｇ、ビニルスルホン化合物（ＨＤ−１）を１．５ｇ、ベンゾトリアゾールを１．０ｇ、弗素系活性剤（サーフロンＫＨ４０：前出）を１．０ｇ添加し溶解した。次に、上記マット剤分散液３０ｇを添加して攪拌し、表面保護層塗布液を調製した。
【０１８１】
ＨＤ−１：（ＣＨ₂＝ＣＨＳＯ₂ＣＨ₂）₂ＣＨＯＨ
《試料１０１〜１１１の作製》
前記感光層塗布液Ａ及び感光層塗布液Ｂと表面保護層塗布液を図１及び図２に示す押出し（エクストルージョン）コーターを用いて感光層Ａ、感光層Ｂ及び保護層１層の計３層を同時に重層塗布することにより試料を作製した、なお表２に示すように一般式（１）、（２）、（３）の添加量を変化させることにより、試料１０１〜１１１を作製した。塗布は、感光層Ａは塗布銀量０．７ｇ／ｍ²、感光層Ｂは塗布銀量０．３ｇ／ｍ²、表面保護層は乾燥膜厚で２．５μｍになる様にして行った。その後、乾燥温度５０℃、露点温度１０℃の乾燥風を用いて、１０分間乾燥した。得られた試料の露光、現像処理、評価方法等は実施例１に記載と同様の方法を用いた。
【０１８２】
得られた結果を表３に示す。
【０１８３】
【表３】

【０１８４】
表３から、比較の試料に比べて、本発明の試料は低カブリ、高感度であり、且つ、保存性が向上していることが明らかである。
【０１８５】
【発明の効果】
本発明により、低カブリ、高感度であり、且つ、保存性の向上した熱現像感光材料、それを用いる画像記録方法及び画像形成方法を提供することが出来た。
【図面の簡単な説明】
【図１】本発明に用いる塗布装置の概略構成図を示す。
【図２】エクストルージョン型ダイコーターの三つのスリットより吐出させて積層し、背面を支持された支持体上に塗布する方式を模式的に示す図。
【符号の説明】
１ 支持体
２ 塗布バックアップロール
３ コーティングダイ
４ 塗布液
Ｐ 送液ポンプ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photothermographic material, an image recording method, and an image forming method.
[0002]
[Prior art]
Conventionally, in the fields of printing plate making and medical treatment, 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. Therefore, there has been a need for a technique relating to a photothermographic material that can be efficiently exposed by a laser image setter or a laser imager and can form a clear black image with high resolution.
[0003]
As a technique for this purpose, a silver halide light-sensitive material that forms a photographic image by heat treatment is known. Morgan and B.M. U.S. Pat. Nos. 3,152,904, 3,457,075 by Shely or D.C. “Thermal Processed Silver Systems,” Imaging Processes and Materials, 8th Edition, Sturge (V) Stage (V), St. (Stage), “Thermal Processed Silver Systems” by H Klosterboer . Wallworth, A.M. Edited by Shepp, 279, 1989, and the like.
[0004]
Such a photothermographic material usually contains a reducible silver source (for example, an organic silver salt), a catalytically active amount of a photocatalyst (for example, a silver halide), and a reducing agent, usually dispersed in an organic binder matrix. ing. The photothermographic material is stable at normal temperature, but generates silver by a redox reaction between a reducible silver source (acting as an oxidizing agent) and a reducing agent when heated to a high temperature after exposure.
[0005]
This redox reaction is promoted by the catalytic action of the latent image generated by exposure. The silver produced by the reaction of the organic silver salt in the exposed area provides a black image that contrasts with the unexposed area and forms an image. An antifoggant for controlling the fogging of this image is used, and the most effective method as a conventional antifogging technique is a method using a mercury compound as an antifoggant.
[0006]
The use of a mercury compound as an antifoggant in a light-sensitive material is disclosed in, for example, US Pat. No. 3,589,903. However, the use of highly toxic mercury compounds is not preferred, and the development of non-mercury antifoggants has been desired. Examples of non-mercury antifoggants include various polyhalides such as US Pat. Nos. 3,874,946, 4,756,999, 5,340,712, and European Patent No. Nos. 605,981A1, 622,666A1, 631,176A1, JP-B-54-165, JP-A-7-2781, and the like.
[0007]
However, the compounds described in these publications have problems that the antifogging effect is low and the color tone of silver is deteriorated. Furthermore, there is a problem that fogging in unexposed areas increases when exposure and development are performed after the photosensitive materials are stacked and stored under forced conditions of humidification and heating.
[0008]
As a method for solving these problems, JP-A-9-160164, 9-244178, 9-258367, 9-265150, 9-281640, 9-319022 and the like have been improved. Described polyhalogen compounds are described.
[0009]
However, the photothermographic material for medical laser imagers or the photothermographic material for output of a printing laser image setter containing a thickening agent and having an oscillation wavelength of 600 to 800 nm is particularly suitable for the above-mentioned polythene. When a halogen compound is applied, the above-described problems are considerably improved, but there is a problem in that the preservability of an image is poor with time, such as fogging of a developed sample over time.
[0010]
Further, JP-A-6-208193 discloses a photothermographic material having improved fog stability during the storage period by containing a halogenated antifogging compound and a compound having an isocyanate group. The anti-fogging compound is not sufficient in terms of storage stability with time, and the reaction of the antifogging compound proceeds with time at the coating solution stage in the production process, and the sensitivity of the light-sensitive material greatly fluctuates accordingly. was there.
[0011]
Further, JP-A-64-72145, JP-A-9-281638, and the like disclose a photothermographic material having improved fog stability during storage by incorporating a benzoylcarboxylic acid antifoggant compound. However, there is a problem in that degradation performance such as sensitivity fluctuation due to storage over time is caused.
[0012]
In view of the above, there has been a demand for the development of a photothermographic material that solves the problems as described above, and in particular, has excellent fog stability during the storage period.
[0013]
[Problems to be solved by the invention]
An object of the present invention is to provide a photothermographic material having low fog and high sensitivity and excellent storability, and an image recording method and an image forming method using the same.
[0014]
[Means for Solving the Problems]
The above object of the present invention has been achieved by the following items 1 to 12.
[0015]
1. A photothermographic material containing at least an organic silver salt, a photosensitive silver halide, a reducing agent and a binder on a support, wherein the photothermographic material contains the compound represented by the general formula (1). Photosensitive material.
[0016]
2. L₁2. The photothermographic material according to 1, wherein is an alkylene group or an arylene group.
[0017]
3. L₁2. The photothermographic material according to 1 above, wherein is a phenylene group.
[0018]
4). L₁2. The photothermographic material according to 1 above, wherein is an orthophenylene group.
[0019]
5. 5. The photothermographic material according to 1, 2, 3 or 4, which contains a compound represented by the general formula (2).
[0020]
6). 4. The photothermographic material according to the above 1, 2, or 3, which comprises a compound represented by the general formula (3).
[0021]
7. L₂7. The photothermographic material as described in 6 above, wherein is an alkylene group or an arylene group.
[0022]
8). L₂7. The photothermographic material as described in 6 above, wherein is a phenylene group.
[0023]
9. L₂7. The photothermographic material as described in 6 above, wherein is an orthophenylene group.
[0024]
10. The photothermographic material according to any one of 1 to 9 is exposed using a laser scanning exposure machine in which an angle formed between the exposure surface of the photosensitive material and the scanning laser beam is not substantially perpendicular. A characteristic image recording method.
[0025]
11. 10. An image recording method comprising: exposing the photothermographic material according to any one of 1 to 9 above using a laser scanning exposure machine in which scanning laser light for recording on the photosensitive material is a vertical multi-beam.
[0026]
12 The photothermographic material according to any one of 1 to 9, wherein the photothermographic material is 1 to 1000 mg / cm in solvent.²An image forming method comprising heat-developing in a contained state.
[0027]
Hereinafter, the present invention will be described in detail.
In the photothermographic material of the present invention, a conventional photothermographic material is obtained by using the compound represented by the general formula (1) having a sulfonyloxy group and a carboxyl group and / or a salt of a carboxyl group in the same molecule. It has been found that the antifoggant compound of benzoylcarboxylic acid type used in the present invention significantly improves the fog stability during the storage period, which has not been sufficiently improved.
[0028]
Furthermore, the fog stability during the storage period described above can be further improved by using the compound represented by the general formula (2) or (3) together with the compound represented by the general formula (1). It turns out that it improves.
[0029]
Further, it was found that the light resistance of the image after the development processing is improved by using the compounds represented by the general formulas (1), (2) and (3) according to the present invention.
[0030]
The compounds represented by the general formulas (1), (2) and (3) according to the present invention will be described.
[0031]
In the general formulas (1), (2) and (3), R₁, R₂, R_ThreeEach represents a hydroxyl group, a mercapto group, a halogen atom, a cyano group, a sulfo group, a nitro group, a sulfino group, a hydrazino group, a heterocyclic group, a hydrocarbon group, or a group formed by a combination thereof.
[0032]
R₁, R₂, R_ThreeExamples of the halogen atom represented by the formula include a fluorine atom, a chlorine atom, a bromine atom and the like.
[0033]
R₁, R₂, R_ThreeThe hydrazino group represented by the formula represents an alkyl hydrazino group or an aryl hydrazino group, and examples of the alkyl hydrazino group include a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, and a decyl group. It is done. In addition, examples of the aryl group of the arylhydrazino group include a phenyl group and a naphthyl group. Each of the substituents described above may further have a substituent.
[0034]
R₁, R₂, R_ThreeThe heterocyclic group represented by is preferably a 5- to 7-membered ring and may be condensed, and examples thereof include an imidazolyl group, a pyridyl group, a furyl group, a piperidyl group, and a morpholino group.
[0035]
R₁, R₂, R_ThreeAs the hydrocarbon group represented by formula (1), the hydrocarbon group represented by the formula is, for example, a linear, branched or cyclic alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 16, for example, methyl group, ethyl group, iso-propyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, 2- An ethylhexyl group, etc.), an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 16 carbon atoms such as vinyl group, allyl group, 2-butenyl group, 3- Pentenyl group, etc.), alkynyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 16 carbon atoms). Ethynyl group, 1-propynyl group, 3-pentynyl group, etc.), aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 16 carbon atoms such as phenyl and naphthyl. , Anthonyl, phenanthonyl, pyrenyl, etc.), an aralkyl group (preferably having a carbon number of 7-30, more preferably 7-20, particularly preferably 7-16, such as benzyl, phenethyl, diphenylmethyl, trityl, etc. And the like. The hydrocarbon group described above further includes a hydroxyl group, a mercapto group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a cyano group, a sulfo group, a nitro group, a sulfino group, a hydrazino group, a heterocyclic ring. It may further have a substituent such as a group (for example, imidazolyl group, pyridyl group, furyl group, piperidyl group, morpholino group, etc.).
[0036]
Among the above descriptions, R₁, R₂, R_ThreeIs preferably an alkyl group, an aryl group, or an aralkyl group, particularly preferably an alkyl group or an aryl group, and most preferably An alkyl group or an aryl group having a halogen atom.
[0037]
L₁Or L₂As the divalent hydrocarbon group represented by, for example, a linear, branched or cyclic alkylene group (preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms such as methylene. Group, ethylene group, trimethylene group, propylene group, ethylethylene group, hexamethylene group, 1,2-cyclohexylene group, etc.), alkenylene group (preferably having 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms). , Particularly preferably 2 to 4, for example, vinylene group, propenylene group, etc.), alkynylene group (preferably 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, particularly preferably 2 to 4 carbon atoms, For example, an ethynylene group, a 3-pentynylene group, etc.), an arylene group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly Preferably, it is 6-12, for example, a phenylene group, a naphthylene group, etc.), an aralkylene group (preferably having 7-20 carbon atoms, more preferably 7-16, particularly preferably 7-12, A xylylene group, etc.).
[0038]
Among the above descriptions, L₁Or L₂As the divalent hydrocarbon group represented by the formula, an alkylene group and an arylene group are preferable, and an alkylene group and a phenylene group are more preferable. Specifically, a methylene group, an ethylene group, a propylene group, and a phenylene group are preferable, a phenylene group is more preferable, and an orthophenylene group is particularly preferable.
[0039]
L₁Or L₂The divalent hydrocarbon group represented by formula (1) may have a substituent, and examples of the substituent include an alkyl group (preferably having a carbon number of 1 to 20, more preferably 1 to 12, and particularly preferably 1 to 8. And examples thereof include a methyl group, an ethyl group, an iso-propyl group, a tert-butyl group, an n-octyl group, an n-decyl group, an n-hexadecyl group, a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group. An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms such as vinyl group, allyl group, 2-butenyl group, and 3-pentenyl group). Alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms such as 1-propynyl group and 3-pentynyl group. ), An aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms such as a phenyl group and a naphthyl group), an amino group (preferably carbon atoms). A number of 0 to 20, more preferably 0 to 10, particularly preferably 0 to 6, and examples thereof include an amino group, a methylamino group, a dimethylamino group, a diethylamino group, and a dibenzylamino group), an alkoxyl group ( Preferably it is C1-C20, More preferably, it is 1-12, Most preferably, it is 1-8, for example, a methoxy group, an ethoxy group, a butoxy group etc. are mentioned), an aryloxy group (preferably C6-C6). 20, more preferably 6 to 16, particularly preferably 6 to 12, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms such as an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group), an alkoxycarbonyl group ( Preferably they are C2-C20, More preferably, it is 2-16, Most preferably, it is 2-12, for example, a methoxycarbonyl group, an ethoxycarbonyl group, etc. are mentioned), an aryloxycarbonyl group (preferably C7-C7). 20, More preferably, it is 7-16, Most preferably, it is 7-10, for example, a phenyloxycarbonyl group etc. are mentioned, for example, Preferably it is C2-C20, More preferably, it is 2-16, Most preferably, it is 2-16. 2-10, for example, acetoxy, benzoyloxy, etc.), acylami Group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as acetylamino group and benzoylamino group). ), An alkoxycarbonylamino group (preferably having a carbon number of 2 to 20, more preferably 2 to 16, particularly preferably 2 to 12, such as a methoxycarbonylamino group), an aryloxycarbonylamino group (preferably Has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group, an alkylsulfonylamino group, or an arylsulfonylamino group (preferably having a carbon number). 1 to 20, more preferably 1 to 16, particularly preferably 1 to 12, and examples thereof include a methanesulfonylamino group and a benzenesulfonylamino group.), A sulfamoyl group (preferably having a carbon number of 0 to 20, and more preferably). Is 0 to 16, particularly preferably 0 to 12, for example A sulfamoyl group, a methylsulfamoyl group, etc.), a carbamoyl group (preferably having a carbon number of 1-20, more preferably 1-16, particularly preferably 1-12, such as a carbamoyl group, a methylcarbamoyl group, Phenylcarbamoyl group, etc.), alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms such as methylthio group and ethylthio group). An arylthio group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as a phenylthio group), a sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably Is 1 to 16, particularly preferably 1 to 12, and examples thereof include a mesyl group and a tosyl group. ), Sulfinyl groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms such as methanesulfinyl group and benzenesulfinyl group), hydroxyl groups, mercapto groups , Halogen atoms (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, nitro group, sulfino group, hydrazino group, heterocyclic group (eg imidazolyl, pyridyl, furyl, piperidyl, morpholino, etc.) Etc.). These substituents may be further substituted. When there are two or more substituents, they may be the same or different.
[0040]
L₁Or L₂As the substituent of the group represented by the formula, an alkyl group, aryl group, alkoxyl group, aryloxy group, alkylthio group, arylthio group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonyl An amino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, a hydroxyl group, a halogen atom, a cyano group, a heterocyclic group and the like are preferable, an alkyl group and a halogen atom are more preferable, and an alkyl group is particularly preferable. Also R₁, R₂Or R_ThreeAnd a group represented by₁Or L₂And a group represented by may be linked to form a ring.
[0041]
The cation represented by M represents an organic or inorganic cation, such as an alkali metal ion (lithium ion, sodium ion, potassium ion, cesium ion, etc.), alkaline earth metal ion (magnesium ion, calcium ion, etc.), ammonium ( Ammonium, trimethylammonium, triethylammonium, tetramethylammonium, tetraethylammonium, tetrabutylammonium, etc.), pyridinium, imidazolium, phosphonium and the like.
[0042]
M is preferably a hydrogen atom or an alkali metal ion, and more preferably a hydrogen atom.
[0043]
This compound is generally used in an amount of at least 0.005 mole / silver mole in the photosensitive layer. Usually, it is in the range of 0.005 to 0.3 mol per mol of silver, and preferably in the range of 0.01 to 0.15 mol per mol of silver.
[0044]
Although the specific example of a compound represented by General formula (1) below is shown, this invention is not limited to these.
[0045]
[Chemical 1]

[0046]
[Chemical formula 2]

[0047]
[Chemical Formula 3]

[0048]
[Formula 4]

[0049]
Although the specific example of a compound represented by General formula (2) below is shown, this invention is not limited to these.
[0050]
[Chemical formula 5]

[0051]
[Chemical 6]

[0052]
[Chemical 7]

[0053]
[Chemical 8]

[0054]
[Chemical 9]

[0055]
Although the specific example of a compound represented by General formula (3) below is shown, this invention is not limited to these.
[0056]
Embedded image

[0057]
Embedded image

[0058]
Embedded image

[0059]
Embedded image

[0060]
Commercially available compounds can be used for the compounds represented by the above general formulas (1) to (3) according to the present invention. Pharm. Bulletin, 31 (8), 2632 (1983), J. Am. Chem. Soc. , Section B Physical Organic Chemistry, Part1. pp. 145-148 (1971), J. MoI. Amer. Chem. Soc. 77, 1909 (1955), Org. Prep. Proced. Int. 28 (5), 609 (1996), Chem. Ber. 44, 1236 (1911), J. Am. Amer. Chem. Soc. 60, 2502 (1938), Bull. Soc. Khim. Fr. 25 (3) 173 (1901), Chem. Abstr. 9861 (1960), German Patent No. 2,970,18, Justus Liebigs Ann. Chem. 300 299 (1898) and the like.
[0061]
The mixing ratio (mass ratio) of the compounds represented by the above general formulas (1) and (2) according to the present invention is preferably 100: 5 to 100: 100, more preferably 100: 10 to 100: 50.
[0062]
The mixing ratio of the compounds represented by the general formulas (1) and (3) according to the present invention is preferably 100: 5 to 100: 300, more preferably 100: 10 to 100: 150. .
[0063]
The mixing ratio of the compounds represented by the above general formulas (1), (2) and (3) according to the present invention is preferably 100: (5-100) :( 5-300), Preferably, it is 100: (10-50) :( 10-150).
[0064]
The silver halide grains according to the present invention function as an optical sensor. In the present invention, the average particle size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.1 μm, and particularly preferably in order to suppress white turbidity after image formation and obtain good image quality. It is 0.02 μm to 0.08 μm.
[0065]
The grain size here refers to the length of the edge of the silver halide grain when the silver halide grain is a so-called normal crystal of a cube or octahedron. In the case of non-normal crystals, for example, in the case of spherical, rod-like, or tabular grains, the diameter when considering a sphere equivalent to the volume of silver halide grains is shown. The silver halide is preferably monodispersed.
[0066]
The monodispersion here refers to a case where the monodispersity obtained by the following formula is 40% or less. In the present invention, the monodispersity is more preferably 30% or less, particularly preferably 0.1% or more and 20% or less.
[0067]
Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100
In the present invention, it is more preferable that the silver halide grains are monodisperse grains having an average grain diameter of 0.1 μm or less, and the graininess of the image is also improved by using this range.
[0068]
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 50% or more, further 70% or more, particularly 80% or more. Is preferred. The ratio of the Miller index [100] plane is determined by T.T. based on the adsorption dependency of the [111] plane and the [100] plane in the adsorption of the sensitizing dye. Tani, J .; Imaging Sci. 29, 165 (1985).
[0069]
Another preferred silver halide shape is a tabular grain. The tabular grains referred to here are those having an aspect ratio = r / h of 3 or more when the square root of the projected area is the grain size r μm and the thickness in the vertical direction is h μm. Among them, the aspect ratio is more 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 U.S. Pat. Nos. 5,264,337, 5,314,798, 5,320,958, etc., and the desired tabular grains can be obtained with reference to the above patents. Can do.
[0070]
When these tabular grains are used in the present invention, the sharpness of the image is further improved. 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. AgX particles according to the present invention are obtained from 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 an Ag emulsion prepared by the method described in “Zelikman et al. Making and Coating Photographic Emulsion” (published by The Focal Press, 1964).
[0071]
The silver halide according to the present invention is preferably contained in an amount of 0.75 to 30% by mass relative to the organic silver salt.
[0072]
The silver halide according to the present invention preferably contains a metal ion belonging to Groups 6 to 11 of the periodic table. As the metal, W, Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, Pt, and Au are preferable.
[0073]
These metal ions can be introduced into the silver halide in the form of metal complexes or metal complex ions. As these metal complexes or metal complex ions, hexacoordinate metal complexes represented by the following general formula are preferable.
[0074]
General formula [ML₆]^m
In the formula, 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.
[0075]
Specific preferred examples of M are rhodium (Rh), ruthenium (Ru), rhenium (Re), iridium (Ir) and osmium (Os).
[0076]
Specific examples of transition metal complex ions are shown below, but the present invention is not limited thereto.
1: [RhCl₆]^3-
2: [RuCl₆]^3-
3: [ReCl₆]^3-
4: [RuBr₆]^3-
5: [OsCl₆]^3-
6: [IrCl₆]^Four-
7: [Ru (NO) Cl_Five]^2-
8: [RuBr_Four(H₂O)]^2-
9: [Ru (NO) (H₂O) Cl_Four]^-
10: [RhCl_Five(H₂O)]^2-
11: [Re (NO) Cl_Five]^2-
12: [Re (NO) (CN)_Five]^2-
13: [Re (NO) Cl (CN)_Four]^2-
14: [Rh (NO)₂Cl_Four]^-
15: [Rh (NO) (H₂O) Cl_Four]^-
16: [Ru (NO) (CN)_Five]^2-
17: [Fe (CN)₆]^3-
18: [Rh (NS) Cl_Five]^2-
19: [Os (NO) Cl_Five]^2-
20: [Cr (NO) Cl_Five]^2-
21: [Re (NO) Cl_Five]^-
22: [Os (NS) Cl_Four(TeCN)]^2-
23: [Ru (NS) Cl_Five]^2-
24: [Re (NS) Cl_Four(SeCN)]^2-
25: [Os (NS) Cl (SCN)_Four]^2-
26: [Ir (NO) Cl_Five]^2-
27: [Ir (NS) Cl_Five]^2-
One kind of these metal ions, metal complexes or metal complex ions may be used, or two or more kinds of the same and different metals may be used in combination. The content of these metal ions, metal complexes or metal complex ions is generally 1 × 10 5 per mole of silver halide.^-9~ 1x10^-2Molar is suitable, preferably 1 × 10^-8~ 1x10^-FourIs a mole.
[0077]
The compounds providing these metal ions or complex ions are preferably added during silver halide grain formation and incorporated into the silver halide grains. Preparation of silver halide grains, that is, nucleation, growth, physical ripening , May be added at any stage before or after chemical sensitization, but is preferably added at the stage of nucleation, growth and physical ripening, more preferably at the stage of nucleation and growth, most preferably Preferably, it is added at the stage of nucleation.
[0078]
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. Preferably, a distribution can be provided inside the particles.
[0079]
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 NaCl, KCl are dissolved together is added to the water-soluble silver salt solution or water-soluble halide solution during particle formation, or the silver salt solution and the halide solution are mixed simultaneously. When adding a third aqueous solution, a method of preparing silver halide grains by a method of simultaneous mixing of three liquids, a method of introducing an aqueous solution of a required amount of a metal compound into a reaction vessel during grain formation, or a silver halide preparation There is a method of adding and dissolving another silver halide grain which has been previously doped with metal ions or complex ions. In particular, a method of adding an aqueous solution of a metal compound powder or an aqueous solution in which a metal compound and NaCl, KCl are dissolved together is added to the water-soluble halide solution.
[0080]
When added to the particle surface, a necessary 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 physical ripening, or at the time of chemical ripening.
[0081]
The silver halide grains according to the present invention may or may not be desalted after the formation of the grains. However, when desalting is performed, water washing is performed using a method known in the art such as a noodle method or a flocculation method. It can desalinate by doing.
[0082]
The silver halide grains according to the present invention are preferably chemically sensitized. As a preferable chemical sensitization method, a sulfur sensitization method, a selenium sensitization method and a tellurium sensitization method can be used as is well known in the art. Further, noble metal sensitization methods such as gold compounds, platinum, palladium, iridium compounds and reduction sensitization methods can be used. As the compound preferably used in the sulfur sensitization method, selenium sensitization method and tellurium sensitization method, known compounds can be used, but compounds described in JP-A-7-128768 can be used. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, P = Te. Compounds having a bond, tellurocarboxylates, tellurocarboxylic esters, di (poly) tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having a P-Te bond, Te-containing heterocycles, A tellurocarbonyl compound, an inorganic tellurium compound, colloidal tellurium, or the like can be used. Compounds preferably used for the noble metal sensitization include, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, gold selenide, US Pat. No. 2,448,060, British Patent 618,061, etc. Can preferably be used.
[0083]
As specific compounds of the reduction sensitization method, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds, etc. can be used in addition to ascorbic acid and thiourea dioxide. . Further, reduction sensitization can be performed by ripening the emulsion while maintaining the pH at 7 or higher or the pAg at 8.3 or lower. Further, reduction sensitization can be performed by introducing a single addition portion of silver ions during grain formation.
[0084]
The organic silver salt according to the present invention is a reducible silver source and is an organic acid containing a reducible silver ion source. Examples of the organic acid used in the present invention include aliphatic carboxylic acid, carbocyclic carboxylic acid, heterocyclic carboxylic acid, heterocyclic compound and the like, but particularly long chain (10-30, preferably 15-25). The aliphatic carboxylic acid having the number of carbon atoms) and the heterocyclic carboxylic acid having a nitrogen-containing heterocyclic ring are preferably used. An organic silver salt complex having a total stability constant with respect to silver ions having a ligand of 4.0 to 10.0 is also useful.
[0085]
The content of the organic silver salt according to the present invention in the photosensitive material is 3 g / m.²The following is preferable, more preferably 2 g / m.²Or less, particularly preferably 0.2 to 2 g / m.²It is.
[0086]
Examples of organic acid silver salts according to the present invention are described in Research Disclosure Nos. 17029 and 29963 and include the following: silver salts of fatty acids (eg, gallic acid, oxalic acid, behenic acid, arachidic acid, Silver salts of stearic acid, palmitic acid, lauric acid, etc.); silver carboxyalkylthiourea salts (for example, 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc. ); A silver complex of a polymerization reaction product of an aldehyde and a hydroxy-substituted aromatic carboxylic acid (for example, aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.) and hydroxy-substituted aromatic carboxylic acids (for example, salicylic acid, benzoic acid, 3, 5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid, etc.) A silver complex or a complex of a thione, such as 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thione, and 3-carboxymethyl-4 -Thiazoline-2-thione), imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,4-triazole and benzotriazole And silver complexes and salts; silver salts such as saccharin and 5-chlorosalicylaldoxime; and silver salts of mercaptan derivatives. Among the organic silver salts described above, fatty acid silver salts are preferably used, and more preferably silver behenate, silver arachidate and silver stearate.
[0087]
The dispersion of the aqueous organic silver salt according to the present invention is obtained by mixing silver nitrate and an organic acid alkali metal salt, but using a simultaneous mixing method in which silver nitrate and silver halide are simultaneously added and mixed at the time of organic silver salt formation. Are preferably manufactured.
[0088]
For example, an alkali metal hydroxide (for example, sodium hydroxide, potassium hydroxide, etc.) is added to an organic acid to produce an organic acid alkali metal salt soap (for example, sodium behenate, sodium arachidate, etc.). By using the jet method, silver nitrate and silver halide can be simultaneously added and mixed to produce an aqueous organic silver salt dispersion according to the present invention.
[0089]
Furthermore, the aqueous organic silver salt dispersion according to the present invention can be prepared by using a so-called control triple jet method in which an alkali metal salt of an organic acid, silver nitrate and silver halide are simultaneously added and mixed.
[0090]
In the present invention, from the viewpoint of simplicity in the production process, the method for producing an aqueous organic silver salt dispersion using the above-described control double jet method is preferably used. Further, from the viewpoint of producing a high-sensitivity photothermographic material, a method for producing an aqueous organic silver salt dispersion using the above-described control triple jet method is preferably used.
[0091]
The photothermographic material of the present invention preferably contains a reducing agent. Examples of suitable reducing agents are described in US Pat. Nos. 3,770,448, 3,773,512, 3,593,863, and Research Disclosure 17029 and 29963, There are things. Aminohydroxycycloalkenone compounds (eg, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones esters (eg, piperidinohexose reductone monoacetate) as precursors of reducing agents; N— Hydroxyurea derivatives (eg, Np-methylphenyl-N-hydroxyurea); aldehyde or ketone hydrazones (eg, anthracene aldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (Eg hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); sulfohydroxamic acids (eg benzenesulfohydroxam ); Sulfonamidoanilines (eg, 4- (N-methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (eg, 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); tetrahydro Quinoxalines (eg, 1,2,3,4-tetrahydroquinoxaline); amide oximes (eg, phenylamidooxime, 2-thienyl-amidooxime, p-phenoxy-phenylamidoxime, etc.); azines (eg, fat A combination of an aromatic carboxylic acid aryl hydrazide and ascorbic acid); a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine; a hydroxamic acid; a combination of an azine and a sulfonamide phenol; α-cyanophenyl vinegar Acid derivatives; combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; 5-pyrazolones; sulfonamide phenol reducing agents; 2-phenylindane-1,3-dione etc .; chromane; 1,4-dihydropyridines (For example, 2,6-dimethoxy-3,5-dicarboethoxy-1,4-dihydropyridine); bisphenols (for example, bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane, bis ( 6-hydroxy-m-tri) mesitol, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,5-ethylidene-bis (2-tert-butyl-6-methyl) phenol) UV-sensitive ascorbic acid derivatives and 3-pyrazolidones. Of these, particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (A).
[0092]
Embedded image

[0093]
In the formula, R represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (for example, a butyl group, 2,4,4-trimethylpentyl group, etc.), and R ′ and R ″ have 1 to 5 carbon atoms. An alkyl group (for example, a methyl group, an ethyl group, a t-butyl group, etc.) is represented.
[0094]
Specific examples of the compound represented by formula (A) are shown below. However, the present invention is not limited to these.
[0095]
Embedded image

[0096]
Embedded image

[0097]
The amount of reducing agent used, including the compound represented by the general formula (A), is preferably 1 × 10 5 per mole of silver.^-2-10 mol, especially 1 x 10^-2~ 1.5 mol.
[0098]
The photothermographic material of the present invention may contain an antifoggant. Known as an antifoggant is mercury ion, and the use of a mercury compound as an antifoggant in a light-sensitive material is disclosed in, for example, US Pat. No. 3,589,903. However, since mercury compounds are environmentally unfavorable, non-mercury fog prevention as disclosed in, for example, US Pat. Nos. 4,546,075 and 4,452,885 and JP-A-59-57234 An agent is preferably used in the present invention.
[0099]
Particularly preferred non-mercury antifoggants include compounds such as those disclosed in US Pat. Nos. 3,874,946 and 4,756,999, —C (X₁) (X₂) (X_Three) (Where X₁And X₂Represents a halogen atom and X_ThreeRepresents a hydrogen or halogen atom), and a heterocyclic compound having one or more substituents represented by.
[0100]
Other suitable antifoggants include compounds described in paragraphs [0030] to [0036] of JP-A-9-288328 and paragraphs [0062] to [0063] of JP-A-9-90550. And the compounds disclosed in US Pat. No. 5,028,523 and European Patent Nos. 600,587, 605,981, 631,176, etc. I can do it.
[0101]
To the photothermographic material of the invention, it is preferable to add a color tone for the purpose of improving the silver tone after development. Examples of suitable toning agents are disclosed in Research Disclosure No. 17029 and include:
[0102]
Imides (eg, phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (eg, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline, and 2,4- Thiazolidinedione); naphthalimides (eg, N-hydroxy-1,8-naphthalimide); cobalt complexes (eg, hexamine trifluoroacetate of cobalt), mercaptans (eg, 3-mercapto-1,2,4-triazole) N- (aminomethyl) aryl dicarboximides (eg, N- (dimethylaminomethyl) phthalimide); combinations of blocked pyrazoles, isothiuronium derivatives and certain photobleaching agents (eg, N, N'-F A combination of Samethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate), and 2- (tribromomethylsulfonyl) benzothiazole ); Merocyanine dyes (e.g. 3-ethyl-5-((3-ethyl-2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-2,4-oxazolidine Dione); phthalazinone, phthalazinone derivatives or metal salts of these derivatives (eg, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3-dihydro-1 , 4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6 Chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); phthalazine + phthalic acid combination; phthalazine (including adducts of phthalazine) and maleic anhydride, and phthalic acid, 2 , 3-Naphthalenedicarboxylic acid or o-phenylene acid derivatives and their anhydrides (for example, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride) in combination with at least one compound Quinazolinediones, benzoxazine, naltoxazine derivatives; benzoxazine-2,4-diones (eg, 1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric-triazines (eg, 2, 4-dihydroxypyrimidine) and tet Laazapentalene derivatives (for example, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene). Preferred toning agents are phthalazone or phthalazine.
[0103]
Examples of the photothermographic material of the present invention include JP-A-63-159841, JP-A-60-140335, JP-A-63-231437, JP-A-63-259651, JP-A-63-304242, JP-A-63-15245, US Sensitization described in Patent Nos. 4,639,414, 4,740,455, 4,741,966, 4,751,175, and 4,835,096 A dye can be used.
[0104]
Useful sensitizing dyes used in the present invention are described in, for example, the literature described or cited in Research Disclosure Item 17643IV-A (December 1978, p.23), Item 18431 (August 1979, p.437). Has been. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, compounds described in JP-A Nos. 9-34078, 9-54409, and 9-80679 are preferably used.
[0105]
In the present invention, a mercapto compound, a disulfide compound, and a thione compound can be contained in order to suppress or promote development and control development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. .
[0106]
When a mercaptan derivative is used in the present invention, any structure may be used, but those represented by Ar—SM and Ar—S—S—Ar are preferred. In the formula, M represents a hydrogen atom or an alkali metal atom, and Ar represents an aromatic ring or condensed aromatic ring having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms.
[0107]
As the aromatic ring, an aromatic carbocycle and a heteroaromatic ring are used. In the present invention, a heteroaromatic ring is preferably used. Examples of the heteroaromatic ring include benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotelrazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, Pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. This heteroaromatic ring is, for example, a halogen atom (for example, Br and Cl), a hydroxyl group, an amino group, a carboxy group, an alkyl group (for example, one or more carbon atoms, preferably 1 to 4 carbon atoms) And an alkoxyl group (for example, one having one or more carbon atoms, preferably one having 1 to 4 carbon atoms). Mercapto-substituted heteroaromatic compounds include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzothiazole, 3-mercapto-1,2,4-triazole, 2 -Mercaptoquinoline, 8-mercaptopurine, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-hydroxy-2-mercaptopyrimidine, 2-mercapto-4-phenyloxazole, and the like. Is not limited to these.
[0108]
In the present invention, it is preferable to contain a matting agent on the photosensitive layer side, and it is preferable to dispose the matting agent on the surface of the photosensitive material in order to prevent damage to the image after heat development. It is preferable to contain 0.5-30% by mass ratio with respect to all the binders on the layer side.
[0109]
The material of the matting agent used in the present invention may be either organic or inorganic.
Examples of inorganic substances include silica described in Swiss Patent No. 330,158 and the like, glass powder described in French Patent No. 1,296,995 and the like, and alkali described in British Patent No. 1,173,181 and the like. Earth metals or carbonates such as cadmium and zinc can be used as the matting agent. Examples of organic substances include starch described in U.S. Pat. No. 2,322,037 and the like, starch derivatives described in Belgian Patent 625,451 and British Patent 981,198, and Japanese Patent Publication No. 44-3643. Polyvinyl alcohol described, polystyrene or polymethacrylate described in Swiss Patent No. 330,158, etc., polyacrylonitrile described in US Pat. No. 3,079,257, etc., No. 3,022,169 etc. An organic matting agent such as polycarbonate can be used.
[0110]
The shape of the matting agent may be either a regular shape or an irregular shape, but is preferably a regular shape, and a spherical shape is preferably used. The size of the matting agent is represented by a diameter when the volume of the matting agent is converted into a sphere. In the present invention, the particle size of the matting agent indicates the diameter converted into a spherical shape.
[0111]
The matting agent used in the present invention preferably has an average particle size of 0.5 μm to 10 μm, more preferably 1.0 μm to 8.0 μm. The coefficient of variation of the particle size distribution is preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less.
[0112]
Here, the variation coefficient of the particle size distribution is a value represented by the following equation.
(Standard deviation of particle size) / (Average value of particle size) × 100
The matting agent used in the present invention can be contained in any constituent layer, but in order to achieve the object of the present invention, it is preferably a constituent layer other than the photosensitive layer, and more preferably viewed from the support. The outermost layer.
[0113]
The method for adding the matting agent used in the present invention may be a method in which the matting agent is dispersed and applied in advance in the coating solution, or a method in which the matting agent is sprayed after the coating solution is applied and before drying is completed. It may be used. When a plurality of types of matting agents are added, both methods may be used in combination.
[0114]
In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer can be included in the constituent layers in order to improve the chargeability. These may be contained in any layer, but are preferably contained in an undercoat layer, a backing layer, a layer between the photosensitive layer and the undercoat, and the like.
[0115]
In the present invention, the conductive compounds described in US Pat. No. 5,244,773, columns 14 to 20 are preferably used.
[0116]
Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other constituent layers. For example, surfactants, antioxidants, stabilizers, plasticizers, ultraviolet absorbers, coating aids and the like may be used in the photothermographic material of the invention. As these additives and the other additives described above, compounds described in Research Disclosure Item 17029 (June 1978, pp. 9-15) can be preferably used.
[0117]
Binders suitable for the photothermographic material of the present invention are transparent or translucent and generally colorless and are natural polymer synthetic resins, polymers and copolymers, and other media forming films such as gelatin, gum arabic, poly (vinyl alcohol) ), Hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly ( Styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (Urethane) Phenoxy resins, poly (vinylidene chloride), poly (epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and polyamides. It may be hydrophilic or non-hydrophilic. Further, in order to protect the surface of the photosensitive material and prevent scratches, a non-photosensitive layer can be provided outside the photosensitive layer. The binder used for these non-photosensitive layers may be the same as or different from the binder used for the photosensitive layer.
[0118]
In the present invention, the binder amount of the photosensitive layer is 1.5 to 10 g / m in order to increase the speed of thermal development.²And more preferably 1.7 to 8 g / m.²It is.
[0119]
The support according to the present invention is preferably a plastic film (for example, polyethylene terephthalate, polycarbonate, polyimide, nylon, cellulose triacetate, polyethylene naphthalate) in order to prevent deformation of the image after development processing.
[0120]
Among them, preferable supports include polyethylene terephthalate (hereinafter abbreviated as PET) and a plastic (hereinafter abbreviated as SPS) support including a styrene polymer having a syndiotactic structure. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.
[0121]
A heat-treated plastic support can also be used. Examples of the plastic to be used include the plastics described above. The heat treatment of the support is a temperature higher than the glass transition point of the support by 30 ° C. or more, preferably 35 ° C. or more, after these supports are formed and before the photosensitive layer is applied, More preferably, heating is performed at a temperature higher by 40 ° C. or more. However, the effect of the present invention cannot be obtained by heating at a temperature exceeding the melting point of the support.
[0122]
Next, the plastic used will be described.
PET is composed of polyethylene terephthalate as a component of polyester. However, in addition to polyethylene terephthalate, terephthalic acid, naphthalene-2,6-dicarboxylic acid, isophthalic acid, butylene dicarboxylic acid, 5-sodium sulfoisophthalic acid, It may be a polyester in which a modified polyester component such as adipic acid or the like and ethylene glycol, propylene glycol, butanediol, cyclohexanedimethanol or the like as a glycol component is contained in an amount of 10 mol% or less of the total polyester.
[0123]
Unlike ordinary polystyrene (atactic polystyrene), SPS is a polystyrene having three-dimensional regularity. The regular stereoregular structure portion of SPS is called a racemo chain, and it is preferable that there are more regular portions such as a 2-chain, 3-chain, 5-chain or more. In the present invention, the racemo-chain is 2 It is preferably 85% or more in the chain, 75% or more in the 3 chain, 50% or more in the 5 chain, and 30% or more in the further chain. The polymerization of SPS can be carried out according to the method described in JP-A-3-131443.
[0124]
A known method can be used for the film-forming method and the undercoating method for the support used in the present invention. Preferably, the methods described in paragraphs [0030] to [0070] of JP-A-9-50094 are used. Is to use.
[0125]
The photothermographic material of the present invention forms a photographic image by heat development processing. The reducible silver source (organic silver salt), the photosensitive silver halide, the reducing agent and, if necessary, the color tone of silver. The photothermographic material preferably contains a toning agent to be suppressed in a state of being dispersed in a normal (organic) binder matrix. The photothermographic material of the present invention is stable at room temperature, but is developed by heating to a high temperature (for example, 80 ° C. to 140 ° C.) after exposure. By heating, silver is generated through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This redox reaction is promoted by the catalytic action of the latent image generated in the silver halide upon exposure. The silver produced by the reaction of the organic silver salt in the exposed areas provides a black image that contrasts with the unexposed areas and forms an image. This reaction process proceeds without supplying a treatment liquid such as water from the outside.
[0126]
The photothermographic material of the present invention has at least one photosensitive layer on a support. Although only the photosensitive layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the photosensitive layer. In order to control the amount of light passing through the photosensitive layer or the wavelength distribution, a filter dye layer on the same side as the photosensitive layer and / or an antihalation dye layer on the opposite side, a so-called backing layer, may be formed. A dye or pigment may be included in the conductive layer. Any dye may be used as long as it has the desired absorption in a desired wavelength range. For example, JP-A-59-6481, JP-A-59-182436, US Pat. No. 4,271,263. U.S. Pat. No. 4,594,312, European Patent Publication 533,008, European Patent Publication 652,473, JP-A-2-216140, JP-A-4-348339, JP-A-7-191432, Compounds such as Kaihei 7-301890 are preferably used.
[0127]
These non-photosensitive layers preferably contain the binder and matting agent, and may further contain a polysiloxane compound, a sliding agent such as wax or liquid paraffin.
[0128]
The photosensitive layer may be composed of a plurality of layers, and the sensitivity may be a high sensitivity layer / a low sensitivity layer or a low sensitivity layer / a high sensitivity layer for gradation adjustment.
[0129]
Details of the photothermographic material are described in, for example, U.S. Pat. Nos. 3,152,904, 3,457,075, and D.I. Morgan and B.M. U.S. Pat. Nos. 3,152,904, 3,457,075 by Shely or D.C. “Thermal Processed Silver Systems,” Imaging Processes and Materials, 8th Edition, Sturge (V) Stage (V), St. (Stage), “Thermal Processed Silver Systems” by H Klosterboer . Wallworth, A.M. Edited by Shepp, 279, 1989, and the like.
[0130]
Among them, the present invention is characterized in that an image is formed by thermally developing a photosensitive material at 80 to 140 ° C. and fixing is not performed. Therefore, the silver halide and the organic silver salt remaining in the unexposed area remain in the photosensitive material as they are without being removed.
[0131]
In the present invention, it is preferable that the optical transmission density of the photosensitive material including a support at 400 nm after heat development is 0.2 or less. A more preferable value of the optical transmission density is 0.02 or more and 0.2 or less.
[0132]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
[0133]
Example 1
<< Preparation of Photographic Support >>
8 W / m on both sides of a 175 μm-thick PET film colored 0.170 in density (measured with Konica Densitometer PDA-65).²・ Corona discharge treatment was performed for a minute.
[0134]
<< Preparation of photosensitive silver halide emulsion 1 >>
After dissolving 7.5 g of ossein gelatin having an average molecular weight of 100,000 and 10 mg of potassium bromide in 900 ml of water, adjusting the temperature to 35 ° C. and pH to 3.0, 370 ml of an aqueous solution containing 74 g of silver nitrate (98/2) Potassium bromide and potassium iodide (equal molar amount with silver nitrate) and iridium chloride in a molar ratio of 1 × 10 5 per mole of silver^-FourWhile maintaining pAg 7.7, 370 ml of an aqueous solution containing a mole was added over 10 minutes by the controlled double jet method. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added and the pH was adjusted to 5 with NaOH to obtain an average particle size of 0.06 μm, a particle size variation coefficient of 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.
[0135]
<< Preparation of powdered organic silver salt >>
In 4720 ml of pure water, 111.4 g of behenic acid, 83.8 g of arachidic acid, and 54.9 g of stearic acid were dissolved at 80 ° C. Next, 540.2 ml of a 1.5 M aqueous sodium hydroxide solution was added while stirring at high speed, and 6.9 ml of concentrated nitric acid was added, followed by cooling to 55 ° C. to obtain an organic acid sodium solution. While maintaining the temperature of the organic acid sodium solution at 55 ° C., the silver halide emulsion (containing 0.038 mol of silver) and 450 ml of pure water were added and stirred for 5 minutes. Next, 760.6 ml of 1M 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 are repeated until the electric conductivity of the filtrate reaches 2 μS / cm, and centrifugal dehydration is carried out, followed by drying with warm air at 37 ° C. until mass loss is eliminated. Obtained.
[0136]
<< Preparation of photosensitive emulsion dispersion >>
14.57 g of polyvinyl butyral powder (Monsanto Butvar B-79) was dissolved in 1457 g of methyl ethyl ketone, and 500 g of powdered organic silver salt was gradually added while stirring with a dissolver type homogenizer and mixed well. Thereafter, dispersion was carried out at a peripheral speed of 13 m and a residence time in the mill of 0.5 minutes using a media type dispersing machine (manufactured by Gettzmann) filled with 80% of 1 mm diameter Zr beads (manufactured by Toray) to prepare a photosensitive emulsion dispersion. did.
[0137]
<< Preparation of photosensitive layer coating solution >>
The photosensitive emulsion (500 g) and MEK (methyl ethyl ketone) 100 g were kept at 21 ° C. with stirring. Antifoggant 1 (0.20 g) was added and stirred for 1 hour. Further, calcium bromide (10% methanol solution 3.25 ml) was added and stirred for 30 minutes. Next, sensitizing dye 1, as shown in Table 1, mixed solution (mixed) of general formula (1) or general formula (1) + (2) or general formula (1) + (3), and supersensitizer Ratio 1: 250-450: 20, 0.1% MEK solution with sensitizing dye, 7 ml) was added and stirred for 1 hour, then the temperature was lowered to 13 ° C., stirred for another 30 minutes, and kept at 13 ° C. As it was, 48 g of polyvinyl butyral was added and sufficiently dissolved, and then the following additives were added.
[0138]
Each compound is added in the following amounts.
A-3 (reducing agent) 15g
Desmodu N3300 (Mobay, aliphatic isocyanate) 1.10 g
Printout prevention agent 1.55g
Phthalazine 1.5g
Tetrachlorophthalic acid 0.5g
4-methylphthalic acid 0.5g
[0139]
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[0140]
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[0141]
After preparing the photosensitive layer coating solution, it was kept at 13 ° C. and coated by the method shown below.
The following layers were sequentially formed on the support to prepare a sample. In addition, each drying was performed at 75 degreeC for 5 minutes.
[0142]
<Back side application>
(Preparation of back surface coating solution)
While stirring to 830 g of methyl ethyl ketone, 84.2 g of cellulose acetate butyrate (Eastman Chemical, CAB381-20) and 4.5 g of a polyester resin (Bostic, VitelPE2200B) were added and dissolved. To the dissolved liquid, 0.30 g of infrared dye 1 was added, and 4.5 g of F-type active agent (Asahi Glass Co., Surflon KH40) dissolved in 43.2 g of methanol and F-type active agent (Dainippon Ink, Inc. Megafag F120K) 2.3 g was added and stirred well until dissolved. Finally, 75 g of silica (WR Grace, Syloid 64 × 6000) dispersed in methyl ethyl ketone at a concentration of 1% by mass with a dissolver type homogenizer was added and stirred to prepare a coating solution for the back surface.
(Application of back surface)
The back surface coating solution thus prepared was coated and dried by an extrusion coater so that the dry film thickness was 3.5 μm. It dried for 5 minutes using the drying air with a drying temperature of 100 degreeC, and dew point temperature of 10 degreeC.
[0143]
The photosensitive layer coating solution and the surface protective layer coating solution were simultaneously applied by using an extrusion coater. The photosensitive layer has a coated silver amount of 2.0 g / m.²The surface protective layer was applied at a speed of 20 m / min so that the dry film thickness was 2.5 μm. Thereafter, drying was performed for 10 minutes using a drying air having a drying temperature of 75 ° C. and a dew point temperature of 10 ° C.
[0144]
<Photosensitive layer side coating>
A solution having a composition below the photosensitive layer is coated with a silver amount of 2.0 g / m.², 8.5 g / m of polyvinyl butyral as a binder²The photosensitive layer coating solution was applied so that
[0145]

<< Exposure and development process >>
From the emulsion surface side of the photosensitive material produced as described above, exposure by laser scanning was given by an exposure machine using a semiconductor laser having a longitudinal multimode wavelength of 800 nm to 820 nm by high frequency superposition as an exposure source. At this time, an image was formed by setting the angle between the exposure surface of the photosensitive material and the exposure laser beam to 75 degrees (note that the unevenness is less than that when the angle is 90 degrees, and sharpness is unexpectedly good. An image was obtained.)
[0146]
Thereafter, using an automatic developing machine having a heat drum, the protective layer of the photosensitive material and the surface of the drum were in contact with each other, and heat development processing was performed at 123 ° C. for 16.5 seconds. At that time, exposure and development were performed in a room adjusted to 23 ° C. and 50% RH. The obtained image was evaluated with a densitometer. The result of the measurement is evaluated by sensitivity (S) (reciprocal of the ratio of the exposure amount giving a density higher by 1.0 than the unexposed portion) and fog, and the sensitivity of the photosensitive material sample 1 in Table 1 is 100. It was expressed as a relative value.
[0147]
<< Evaluation of film preservability >>
One of the two samples was exposed and developed immediately after application, and the other one was stored for 3 days at 25 ° C. and 55% RH after exposure to light and developed. The sensitivity and fog density of both samples were measured. . The obtained results are shown in Table 1.
[0148]
Sensitivity increase (ΔS) = Relative sensitivity after light-shielded storage-Relative sensitivity of immediate development
Increase in fog (Δfog) = fogging after light-shielding storage—fogging immediately developed
The storage stability of the photothermographic material was evaluated from the increase in sensitivity and fogging described above. Here, the exposure, development and evaluation methods are as described above.
[0149]
[Table 1]

[0150]
From Table 1, it is clear that the sample of the present invention has low fog and high sensitivity and improved storage stability compared to the comparative sample. In the region of the present invention, a photothermographic material having an initial performance with low fog and high sensitivity and excellent in storage stability with time was obtained.
[0151]
Example 2
The photothermographic materials 1 to 11 shown in Table 1 of Example 1 were exposed and developed in the same manner as described in Example 1, and then applied to the inside of a glass window exposed to direct sunlight and left for 1 month. The image after being subjected to the following evaluation criteria was visually evaluated for the light resistance of the image, and were shown as Samples 12 to 22, respectively. The obtained results are shown in Table 2.
[0152]
<Evaluation criteria for image storage stability during light irradiation>
A: Almost no change
○: Slight color change, but no problem in practical use
Δ: Image portion discoloration is acceptable but practically acceptable
×: Dmin discolored and density increased, impractical
In the present invention, Dmin is defined as the following general formula.
[0153]
Dmin = density of unexposed area + base (support) density
[0154]
[Table 2]

[0155]
From Table 2, it is clear that the light resistance of the image of the sample of the present invention is improved compared to the comparative sample.
[0156]
Example 3
<< Preparation of subtracted photographic support >>
(Preparation of PET undercoated photographic support)
8 W / m on both sides of a commercially available biaxially stretched heat-fixed thickness of 175 μm, optical density 0.170 (measured with Konica Densitometer PDA-65) blue-colored PET (polyethylene terephthalate) film²・ Corona discharge treatment was applied for one minute, and the following undercoat coating solution a-1 was applied on one surface to a dry film thickness of 0.8 μm and dried to form an undercoat layer A-1, and on the opposite side The undercoat coating solution b-1 shown below was coated on the surface so as to have a dry film thickness of 0.8 μm and dried to form an undercoat layer B-1.
[0157]

Subsequently, the surface of the undercoat layer A-1 and the undercoat layer B-1 is 8 W / m.²・ Corona discharge was applied for a minute, and on the undercoat layer A-1, the following undercoat upper layer coating solution a-2 was used as the undercoat upper layer A-2 so as to have a dry film thickness of 0.1 μm. On B-1, the following undercoat upper layer coating solution b-2 was applied as an undercoat upper layer B-2 having an antistatic function so as to have a dry film thickness of 0.8 μm.
[0158]

[0159]
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[0160]
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[0161]
(Back side application)
While stirring 830 g of methyl ethyl ketone (MEK), 84.2 g of cellulose acetate butyrate (manufactured by Eastman Chemical: CAB381-20) and 4.5 g of a polyester resin (manufactured by Boston: VitelPE2200B) were added and dissolved. Next, 0.30 g of the following infrared dye 2 is added to the dissolved liquid, and 4.5 g of a fluorine-based activator (Asahi Glass Co., Ltd .: Surflon KH40) dissolved in 43.2 g of methanol and a fluorine-based activator ( 2.3 g of Dainippon Ink, Inc .: MegaFag F120K) was added and stirred well until dissolved. Finally, 75 g of silica (manufactured by WR Grace: Syloid 64 × 6000) dispersed in MEK at a concentration of 1% by mass with a dissolver type homogenizer was added and stirred to prepare a coating solution for the back surface side. .
[0162]
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[0163]
The back surface coating solution thus prepared was applied and dried by an extrusion coater so that the dry film thickness was 3.5 μm. It dried for 5 minutes using the drying air with a drying temperature of 100 degreeC, and dew point temperature of 10 degreeC.
[0164]
<< Preparation of photosensitive silver halide emulsion A >>
(Solution A1)
Phenylcarbamoylated gelatin 88.3g
Compound A (10% aqueous methanol solution) 10 ml
Potassium bromide 0.32g
Finish to 5429 ml with water
(Solution B1)
0.67 mol / L silver nitrate aqueous solution 2635 ml
(Solution C1)
Potassium bromide 51.55g
Potassium iodide 1.47g
Finish to 660ml with water
(Solution D1)
Potassium bromide 154.9g
4.41 g of potassium iodide
Iridium chloride (1% solution) 0.93ml
Finish to 1982ml with water
(Solution E1)
0.4 mol / L potassium bromide aqueous solution The following silver potential control amount
(Solution F1)
Potassium hydroxide 0.71g
Finish to 20ml with water
(Solution G1)
56% acetic acid aqueous solution 18.0 ml
(Solution H1)
Anhydrous sodium carbonate 1.72 g
Finish to 151ml with water
A: HO (CH₂CH₂O)_n(CH (CH_Three) CH₂O)₁₇(CH₂CH₂O)_mH (m + n = 5-7)
Using the mixing stirrer shown in Japanese Patent Publication Nos. 58-58288 and 58-58289, ¼ amount of the solution (B1) and the total amount of the solution (C1) were added to the solution (A1) at 45 ° C. and pAg of 8.09. While being controlled, the nucleation was performed by adding 4 minutes 45 seconds by the simultaneous mixing method. After 1 minute, the entire amount of solution (F1) was added. During this time, the pAg was appropriately adjusted using the solution (E1). After 6 minutes, 3/4 amount of the solution (B1) and the whole amount of the solution (D1) were added over 14 minutes and 15 seconds by a simultaneous mixing method while controlling at 45 ° C. and pAg 8.09. After stirring for 5 minutes, the temperature was lowered to 40 ° C., the whole amount of the solution (G1) was added, and the silver halide emulsion was precipitated. The supernatant was removed leaving 2000 ml of the sediment, 10 liters of water was added, and after stirring, the silver halide emulsion was sedimented again. The remaining portion of 1500 ml was left, the supernatant was removed, 10 liters of water was further added, and after stirring, the silver halide emulsion was precipitated. After leaving 1500 ml of the sedimented portion and removing the supernatant, the solution (H1) was added, the temperature was raised to 60 ° C., and the mixture was further stirred for 120 minutes. Finally, the pH was adjusted to 5.8, and water was added so that the amount of silver was 1161 g per mole of silver, whereby photosensitive silver halide emulsion A was obtained. This emulsion was monodisperse cubic silver iodobromide grains having an average grain size of 0.058 μm, a grain size variation coefficient of 12%, and a [100] face ratio of 92%.
[0165]
<< Preparation of powdered organic silver salt A >>
In 4720 ml of pure water, 130.8 g of behenic acid, 67.7 g of arachidic acid, 43.6 g of stearic acid, and 2.3 g of palmitic acid were dissolved at 80 ° C. Next, 540.2 ml of a 1.5 mol / L sodium hydroxide aqueous solution was added, and 6.9 ml of concentrated nitric acid was added, followed by cooling to 55 ° C. to obtain a fatty acid sodium solution.
[0166]
While maintaining the temperature of this fatty acid sodium solution at 55 ° C., 45.3 g of the photosensitive silver halide emulsion A and 450 ml of pure water were added and stirred for 5 minutes. Next, 702.6 ml of 1 mol / L silver nitrate aqueous solution was added over 2 minutes and stirred for 10 minutes to obtain an organic silver salt dispersion. Thereafter, the obtained organic silver salt dispersion was transferred to a water-washing container, deionized water was added and stirred, and then allowed to stand to float and separate the organic silver salt dispersion, thereby removing the lower water-soluble salts. Thereafter, washing with deionized water and drainage were repeated until the electrical conductivity of the drainage reached 2 μS / cm, and centrifugal dehydration was carried out. Then, the obtained cake-like organic silver salt was converted into an air-flow dryer Flashjet dryer (Seishin). Was dried until the water content became 0.1% according to the operating conditions of the nitrogen gas atmosphere and the dryer inlet hot air temperature, to obtain a dried powdered organic silver salt A of an organic silver salt. In addition, the infrared moisture meter was used for the moisture content measurement of an organic silver salt composition.
[0167]
<< Preparation of Preliminary Dispersion A >>
Dissolve 14.57 g of polyvinyl butyral powder (Monsanto: Butvar B-79) in 1457 g of MEK and gradually add 500 g of powdered organic silver salt A while stirring with a dissolver DISPERMAT CA-40M manufactured by VMA-GETZMANN. Preliminary dispersion A was prepared by mixing.
[0168]
<< Preparation of photosensitive emulsion dispersion 1 >>
Media type disperser filled with 80% of the internal volume of 0.5 mm diameter zirconia beads (Toray Industries, Inc .: Treceram) so that the pre-dispersion liquid A is pumped and the residence time in the mill is 1.5 minutes. Photosensitive emulsion dispersion 1 was prepared by supplying to DISPERMAT SL-C12EX type (manufactured by VMA-GETZMANN) and dispersing at a mill peripheral speed of 8 m / s.
[0169]
<< Preparation of stabilizer liquid >>
A stabilizer solution was prepared by dissolving 1.0 g of Stabilizer-1 and 0.31 g of potassium acetate in 4.97 g of methanol.
[0170]
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[0171]
<< Preparation of infrared sensitizing dye liquid A >>
Sensitizing dye 1, mixed solution of general formula (1) or general formula (1) + (2) or general formula (1) + (3) and 5-methyl-2-mercaptobenzimidazole as shown in Table 2 Infrared sensitizing dye solution A was prepared by dissolving (mixing ratio 1: 250 to 450: 20, 0.1% MEK solution with sensitizing dye, 31.3 ml) in the dark.
[0172]
<< Preparation of Additive Liquid a >>
27.98 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -2-methylpropane as a developer, 1.54 g of 4-methylphthalic acid, 0.48 g of the infrared dye 1 Dissolved in 110 g of MEK to make additive solution a.
[0173]
<< Preparation of additive liquid b >>
1.78 g of antifoggant 1 and printout inhibitor and 3.43 g of phthalazine were dissolved in 40.9 g of MEK to obtain additive liquid b.
[0174]
<< Preparation of additive liquid c >>
5.0 g of silver saving agent H-94 was dissolved in 45.0 g of MEK to obtain an additive solution c.
[0175]
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[0176]
<< Preparation of photosensitive layer coating solution A >>
In an inert gas atmosphere (nitrogen 97%), 50 g of the photosensitive emulsion dispersion 1 and 15.11 g of MEK were kept at 21 ° C. with stirring, and the chemical sensitizer S-5 (0.5% methanol solution) 1000 μl was added, and after 2 minutes, 390 μl of antifoggant 1 (10% methanol solution) was added and stirred for 1 hour. Further, 494 μl of calcium bromide (10% methanol solution) was added and stirred for 10 minutes, and then gold sensitizer Au-5 corresponding to 1/20 mol of the chemical sensitizer was added, and further stirred for 20 minutes. Subsequently, 167 ml of a stabilizer solution was added and stirred for 10 minutes, and then 1.32 g of the infrared sensitizing dye solution A was added and stirred for 1 hour. Thereafter, the temperature was lowered to 13 ° C. and further stirred for 30 minutes. While keeping the temperature at 13 ° C., 13.31 g of polyvinyl butyral (Butvar B-79: supra) was added and stirred for 30 minutes, and then 1.084 g of tetrachlorophthalic acid (9.4% MEK solution) was added. Stir for 15 minutes. Further, while continuously stirring, 12.43 g of additive solution a, 1.6 ml of an isocyanate compound (Desmodur N3300, manufactured by Movey Co., Ltd.) 10% MEK solution, 4.27 g of additive solution b were sequentially added and stirred. A layer coating solution A was obtained.
[0177]
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[0178]
<< Preparation of photosensitive layer coating solution B >>
In an inert gas atmosphere (nitrogen 97%), 50 g of the photosensitive emulsion dispersion 1 and 15.11 g of MEK were kept at 21 ° C. with stirring, and the chemical sensitizer S-5 (0.5% methanol solution) 1000 μl was added, and after 2 minutes, 390 μl of antifoggant 1 (10% methanol solution) was added and stirred for 1 hour. Further, 494 μl of calcium bromide (10% methanol solution) was added and stirred for 10 minutes, and then gold sensitizer Au-5 corresponding to 1/20 mole of the chemical sensitizer was added, and further stirred for 20 minutes. Subsequently, 167 ml of a stabilizer solution was added and stirred for 10 minutes, and then 1.32 g of the infrared sensitizing dye solution A was added and stirred for 1 hour. Thereafter, the temperature was lowered to 13 ° C. and further stirred for 30 minutes. While maintaining the temperature at 13 ° C., 13.31 g of polyvinyl butyral (Butvar B-79; supra) was added and stirred for 30 minutes, and then 1.084 g of tetrachlorophthalic acid (9.4% MEK solution) was added. Stir for 15 minutes. While further stirring, 12.43 g of additive solution a, 1.6 ml of an isocyanate compound (Desmodur N3300, manufactured by Movey) 10% MEK solution, 4.27 g of additive solution b, 10.0 g of additive solution c were sequentially added. The photosensitive layer coating solution B was obtained by adding and stirring.
[0179]
<Preparation of matting agent dispersion>
Dissolve 7.5 g of cellulose acetate butyrate (Eastman Chemical: CAB171-15) in 42.5 g of MEK, and add 5 g of calcium carbonate (Special Minerals: Super-Pflex200) to the dissolver type homogenizer. Then, a matting agent dispersion was prepared by dispersing at 8000 rpm for 30 minutes.
[0180]
<< Preparation of surface protective layer coating liquid >>
While stirring 865 g of MEK (methyl ethyl ketone), 96 g of cellulose acetate butyrate (CAB171-15: supra), 4.5 g of polymethylmethacrylic acid (Rohm & Haas Co., Ltd .: Paraloid A-21), vinyl sulfone compound 1.5 g of (HD-1), 1.0 g of benzotriazole, and 1.0 g of a fluorine-based activator (Surflon KH40: supra) were added and dissolved. Next, 30 g of the above matting agent dispersion was added and stirred to prepare a surface protective layer coating solution.
[0181]
HD-1: (CH₂= CHSO₂CH₂)₂CHOH
<< Preparation of Samples 101-111 >>
The photosensitive layer coating solution A, the photosensitive layer coating solution B, and the surface protective layer coating solution are composed of a photosensitive layer A, a photosensitive layer B, and a protective layer 1 in total using an extrusion coater shown in FIGS. Samples were prepared by applying layers simultaneously, and samples 101 to 111 were prepared by changing the amount of addition of general formulas (1), (2), and (3) as shown in Table 2. For coating, the photosensitive layer A has a coating silver amount of 0.7 g / m.²The photosensitive layer B has an applied silver amount of 0.3 g / m.²The surface protective layer was formed so as to have a dry film thickness of 2.5 μm. Thereafter, drying was performed for 10 minutes using a drying air having a drying temperature of 50 ° C. and a dew point temperature of 10 ° C. The same method as described in Example 1 was used for exposure, development processing, evaluation method, and the like of the obtained sample.
[0182]
The obtained results are shown in Table 3.
[0183]
[Table 3]

[0184]
From Table 3, it is clear that the sample of the present invention has low fog and high sensitivity and improved storage stability compared to the comparative sample.
[0185]
【The invention's effect】
According to the present invention, it is possible to provide a photothermographic material having low fog, high sensitivity and improved storage stability, and an image recording method and an image forming method using the same.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a coating apparatus used in the present invention.
FIG. 2 is a diagram schematically showing a method of discharging and stacking from three slits of an extrusion type die coater and applying the back surface onto a supported support.
[Explanation of symbols]
1 Support
2 Application backup roll
3 Coating die
4 Coating liquid
P liquid pump

Claims (12)

A photothermographic material containing at least an organic silver salt, a photosensitive silver halide, a reducing agent, and a binder on a support, and containing the compound represented by the following general formula (1): Photosensitive material.
General formula (1)
R ₁ —SO ₂ —OL ₁ —COOM ₁
[Wherein R ₁ represents a group formed from a hydroxyl group, a mercapto group, a halogen atom, a cyano group, a sulfo group, a nitro group, a sulfino group, a hydrazino group, a heterocyclic group, a hydrocarbon group, or a combination thereof. M ₁ represents a cation. L ₁ represents a divalent group. ] 2. The photothermographic material according to claim 1, wherein L ₁ is an alkylene group or an arylene group. 2. The photothermographic material according to claim 1, wherein L ₁ is a phenylene group. 2. The photothermographic material according to claim 1, wherein L ₁ is an orthophenylene group. The photothermographic material according to claim 1, comprising a compound represented by the following general formula (2):
General formula (2)
R ₂ -COOM ₂
[Wherein R ₂ represents a group that can be formed from a hydroxyl group, a mercapto group, a halogen atom, a cyano group, a sulfo group, a nitro group, a sulfino group, a hydrazino group, a heterocyclic group, a hydrocarbon group, or a combination thereof. M ₂ represents a cation. ] The photothermographic material according to claim 1, comprising a compound represented by the following general formula (3):
General formula (3)
R ₃ —CO—L ₂ —COOM ₃
[Wherein R ₃ represents a group formed from a hydroxyl group, a mercapto group, a halogen atom, a cyano group, a sulfo group, a nitro group, a sulfino group, a hydrazino group, a heterocyclic group, a hydrocarbon group, or a combination thereof. M ₃ represents a cation. L ₂ represents a divalent group. ] 7. The photothermographic material according to claim 6, wherein L ₂ is an alkylene group or an arylene group. The photothermographic material according to claim 6, wherein L ₂ is a phenylene group. The photothermographic material according to claim 6, wherein L ₂ is an orthophenylene group. The photothermographic material according to any one of claims 1 to 9, wherein the photothermographic material is exposed using a laser scanning exposure machine in which an angle formed between the exposure surface of the photosensitive material and the scanning laser beam is not substantially perpendicular. An image recording method characterized by the above. 10. An image recording method comprising exposing the photothermographic material according to claim 1 using a laser scanning exposure machine in which scanning laser light for recording on the photosensitive material is a vertical multi-beam. . An image forming method, wherein the photothermographic material according to any one of claims 1 to 9 is heat-developed in a state containing 1 to 1000 mg / cm ^{2 of a} solvent.

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