JP4061878B2 - Exposure method and image forming method - Google Patents

Description

一般式〔１〕において、Ｒ₁、Ｒ₂及びＲ₃はアルキル基（例えば、メチル基、エチル基、ヘキシル基等）、アルケニル基（例えば、ビニル基、アリル基等）、アルコキシ基（例えば、メトキシ基、エトキシ基、オクチルオキシ基等）、アリール基（例えば、フェニル基、ナフチル基、トリル基等）、ヒドロキシ基、ハロゲン原子、アリールオキシ基（例えば、フェノキシ基等）、アルキルチオ基（例えば、メチルチオ基、ブチルチオ基等）、アリールチオ基（例えば、フェニルチオ基等）、アシル基（例えば、アセチル基、プロピオニル基、ブチリル基、バレリル基等）、スルフォニル基（例えば、メチルスルフォニル基、フェニルスルフォニル基等）、アシルアミノ基、スルフォニルアミノ基、アシルオキシ基（例えば、アセトキシ基、ベンゾキシ基等）、カルボキシル基、シアノ基、スルフォ基及びアミノ基等の置換基を表す。これらのうちで好適な置換基はアリール基、アルケニル基及びシアノ基である。
上記のビイミダゾリル化合物は、米国特許第３，７３４，７３３号明細書及び英国特許第１，２７１，１７７号明細書に記載されている製造方法及びそれに準じた方法により製造することができる。
また、ヨードニウム化合物として以下の一般式〔２〕で表されるヨードニウム化合物が好ましく用いられる。
【００５０】
【化２】

【００５１】
一般式〔２〕において、Ｒ¹、Ｒ²及びＲ³はアルキル基（例えば、メチル基、エチル基、ヘキシル基等）、アルケニル基（例えば、ビニル基、アリル基等）、アルコキシ基（例えば、メトキシ基、エトキシ基、オクチルオキシ基等）、アリール基（例えば、フェニル基、ナフチル基、トリル基等）、ヒドロキシ基、ハロゲン原子、アリールオキシ基（例えば、フェノキシ基等）、アルキルチオ基（例えば、メチルチオ基、ブチルチオ基等）、アリールチオ基（例えば、フェニルチオ基等）、アシル基（例えば、アセチル基、プロピオニル基、ブチリル基、バレリル基等）、スルフォニル基（例えば、メチルスルフォニル基、フェニルスルフォニル基等）、アシルアミノ基、スルフォニルアミノ基、アシルオキシ基（例えば、アセトキシ基、ベンゾキシ基等）、カルボキシル基、シアノ基、スルフォ基及びアミノ基等の置換基を表す。これらのうちで好適な置換基はアリール基、アルケニル基及びシアノ基である。
Ｒ⁴はアセテート、ベンゾエート、トリフルオロアセテートのようなカルボキシレート基及びＯ^-を表す。Ｗは０または１を表す。
Ｘ^-はアニオン性対イオンを表し、好適な例としては、ＣＨ₃ＣＯ₂ ^-、ＣＨ₃ＳＯ₃ ^-及びＰＦ₆ ^-が挙げられる。
Ｒ³がスルフォ基またはカルボキシル基のときは、Ｗは０で、かつ、Ｒ⁴はＯ^-である。
なお、Ｒ¹、Ｒ²及びＲ³の何れかが互いに結合して環を形成するものであてもよい。
上記一般式〔２〕で表されるヨードニウム化合物のうちでも特に好ましい化合物は以下の一般式〔３〕で表されるヨードニウム化合物である。
【００５２】
【化３】

ここにおいて、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、Ｘ^-及びＷ等は前記一般式〔２〕とおなじものを表し、Ｙは炭素原子（−ＣＨ＝；ベンゼン環）を表すか、または窒素原子（−Ｎ＝；ピリジン環）を表す。
【００５３】
上記のヨードニウム化合物は、Ｏｒｇ．Ｓｙｎ．，１９６１及びＡｄｖａｎｃｅｄ Ｏｒｇａｎｉｃ Ｃｈｅｍｉｓｔｒｙ（Ｆｉｅｓｅｒ著）（Ｒｅｉｎｈｏｌｄ，Ｎ．Ｙ．，１９６１）に記載されている製造方法及びそれに準じた方法により製造することができる。
上記の一般式〔１〕で表されるビイミダゾリル化合物及び一般式〔２〕で表されるヨードニウム化合物の好ましい添加量は０．００１〜０．１モル／ｍ²の範囲であり、さらに好ましくは０．００５〜０．０５モル／ｍ²の範囲である。なお、当該化合物は、銀塩光熱写真ドライイメージング材料のいかなる構成層中にも含有させることができるが、還元剤の近傍に存在せることが好ましい。
【００５４】
［ポリハロゲン化合物系プリントアウト防止剤］
また、本発明に用いる銀塩光熱写真ドライイメージング材料においては、還元剤を不活性化し還元剤が有機銀塩を銀に還元できないようにする化合物を用いることが好ましい。これら化合物としては、上記反応活性種がハロゲン原子でないものが好ましいが、ハロゲン原子を活性種として放出する化合物もハロゲン原子でない活性種を放出する化合物と併用することにより使用することができる。ハロゲン原子を活性種として放出できる化合物は多く知られており、これらを併用することにより良好な効果が得られる。
上記ハロゲン原子でない活性種を放出する化合物としては、以下の一般式〔４〕で表される化合物が挙げられる。
【００５５】
【化４】

一般式〔４〕において、Ｑはアリール基またはヘテロ環基を表す。Ｘ₁、Ｘ₂及びＸ₃は水素原子、ハロゲン原子、ハロアルキル基、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、カルバモイル基、スルファモイル基、スルホニル基、アリール基、ヘテロ環基を表すが、Ｘ₁、Ｘ₂及びＸ₃の少なくとも一つはハロゲン原子である。Ｙは−Ｃ（＝Ｏ）−、−ＳＯ−または−ＳＯ₂−を表す。
Ｑで表されるアリール基は、単環であっても、他の環と縮合環を形成したものであってもよく、好ましくは炭素数６〜３０の単環または二環のアリール基（例えば、フェニル基、ナフチル基等）であり、より好ましくはフェニル基、ナフチル基であり、更に好ましくはフェニル基である。
Ｑで表されるヘテロ環基は、Ｎ、ＯまたはＳの少なくとも一つの原子を含む３ないし１０員の飽和もしくは不飽和のヘテロ環基が好ましく、これらは単環であってもよく、また、他の環と縮合環を形成したものであってもよい。
ヘテロ環基としては、縮合環を有していてもよい５ないし６員の不飽和ヘテロ環基が好ましく、より好ましくは縮合環を有していてもよい５ないし６員の芳香族ヘテロ環基である。更に好ましくは、窒素原子を含む縮合環を有していてもよい５ないし６員の芳香族ヘテロ環基であり、特に好ましくは、窒素原子を１ないし４原子含む縮合環を有していてもよい５ないし６員の芳香族ヘテロ環基である。
【００５６】
ヘテロ環基としては、例えば、イミダゾール、ピラゾール、ピリジン、ピリミジン、ピラジン、ピリダジン、トリアゾール、トリアジン、インドール、インダゾール、プリン、チアジアゾール、オキサジアゾール、キノリン、フタラジン、ナフチリジン、キノキサリン、キナゾリン、シンノリン、プテリジン、アクリジン、フェナントロリン、フェナジン、テトラゾール、チアゾール、オキサゾール、ベンズイミダゾール、ベンズオキサゾール、ベンズチアゾール、インドレニン、テトラザインデンであり、より好ましくはイミダゾール、ピリジン、ピリミジン、ピラジン、ピリダジン、トリアゾール、トリアジン、チアジアゾール、オキサジアゾール、キノリン、フタラジン、ナフチリジン、キノキサリン、キナゾリン、シンノリン、テトラゾール、チアゾール、オキサゾール、ベンズイミダゾール、ベンズオキサゾール、ベンズチアゾール、テトラザインデンから導かれるヘテロ環基が好ましく、更に好ましくは、イミダゾール、ピリジン、ピリミジン、ピラジン、ピリダジン、トリアゾール、トリアジン、チアジアゾール、キノリン、フタラジン、ナフチリジン、キノキサリン、キナゾリン、シンノリン、テトラゾール、チアゾール、ベンズイミダゾール、ベンズチアゾールから導かれるヘテロ環基であり、特に好ましくはピリジン、チアジアゾール、キノリン、ベンズチアゾールから導かれるヘテロ環基である。
【００５７】
Ｑで表されるアリール基およびヘテロ環基は−Ｙ−Ｃ（Ｘ₁）（Ｘ₂）（Ｘ₃）の他に置換基を有していてもよく、好ましい置換基としては、アルキル基、アルケニル基、アリール基、アルコキシ基、アリールオキシ基、アシルオキシ基、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、アシルオキシ基、アシルアミノ基、アルコキシカルボニルアミノ基、アリールオキシカルボニルアミノ基、スルホニルアミノ基、スルファモイル基、カルバモイル基、スルホニル基、ウレイド基、リン酸アミド基、ハロゲン原子、シアノ基、スルホ基、カルボキシル基、ニトロ基、ヘテロ環基等が挙げられ、より好ましくは、アルキル基、アリール基、アルコキシ基、アリールオキシ基、アシル基、アシルアミノ基、アルコキシカルボニルアミノ基、アリールオキシカルボニルアミノ基、スルホニルアミノ基、スルファモイル基、カルバモイル基、ウレイド基、リン酸アミド基、ハロゲン原子、シアノ基、ニトロ基、ヘテロ環基であり、更に好ましくは、アルキル基、アリール基、アルコキシ基、アリールオキシ基、アシル基、アシルアミノ基、スルホニルアミノ基、スルファモイル基、カルバモイル基、ハロゲン原子、シアノ基、ニトロ基、ヘテロ環基であり、特に好ましくは、アルキル基、アリール基、ハロゲン原子である。
【００５８】
Ｘ₁、Ｘ₂及びＸ₃は水素原子、ハロゲン原子、ハロアルキル基、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、カルバモイル基、スルファモイル基、スルホニル基、アリール基、ヘテロ環基であり、好ましくはハロゲン原子、ハロアルキル基、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、スルホニル基であり、更に好ましくはハロゲン原子、トリハロメチル基であり、特に好ましくはハロゲン原子である。ハロゲン原子の中でも好ましくは塩素原子、臭素原子、ヨウ素原子であり、更に好ましくは塩素原子、臭素原子であり、特に好ましくは臭素原子である。Ｘ₁、Ｘ₂及びＸ₃の少なくとも一つはハロゲン原子である。
【００５９】
Ｙは−Ｃ（＝Ｏ）−、−ＳＯ−、−ＳＯ₂−を表すが、好ましくは−ＳＯ₂−である。
銀塩光熱写真ドライイメージング材料におけるこれらの活性ハロゲン原子を生成する化合物の添加量は、実質的にハロゲン化銀の生成によるプリントアウト銀の増加が問題にならない範囲が好ましく、前記活性ハロゲンラジカルを生成しない化合物に対する比率で、１５０％以下、更に好ましくは１００％以下である。なお、本発明で用いる銀塩光熱写真ドライイメージング材料には、上記の化合物の他に、従来カブリ防止剤として知られている化合物が含まれてもよく、上記の化合物と同様な反応活性種を生成することができる化合物であっても、カブリ防止機構が異なる化合物であってもよい。これら化合物としては、例えば、米国特許第３，５８９，９０３号明細書、同第４，５４６，０７５号明細書、同第４，４５２，８８５号明細書、特開昭５９−５７２３４号公報、米国特許第３，８７４，９４６号明細書、同第４，７５６，９９９号明細書、特開平９−２８８３２８号公報、特開平９−９０５５０号公報に記載されている化合物が挙げられる。さらに、その他のカブリ防止剤としては、米国特許第５，０２８，５２３号明細書、欧州特許第６００，５８７号明細書、同第６０５，９８１号明細書、同第６３１，１７６号明細書に開示されている化合物も挙げられる。
【００６０】
次に、本発明の銀塩光熱写真ドライイメージング材料に用いられる還元剤につて説明する。
これら還元剤の好適な還元剤の例は、米国特許第３，７７０，４４８号明細書、同第３，７７３，５１２号明細書、同第３，５９３，８６３号明細書、ＲＤ１７０２９及び２９９６３に記載されており、公知の還元剤の中から適宜選択して使用することができるが、有機銀塩に脂肪族カルボン酸銀塩を使用する場合には、２個以上のフェノール基がアルキレン基または硫黄によって連結されたポリフェノール類、特に、フェノール基のヒドロキシ置換位置に隣接した位置の少なくとも一つにアルキル基（例えば、メチル基、エチル基、プロピル基、ｔ−ブチル基、シクロヘキシル基等）またはアシル基（例えば、アセチル基、プロピオニル基等）が置換したフェノール基の２個以上がアルキレン基または硫黄によって連結されたビスフェノール類が好ましい。これら好ましいビスフェノール類のさらに好ましい例としては、例えば、下記の一般式（Ａ）で表される化合物が挙げられる。
【００６１】
【化５】

一般式（Ａ）において、Ｒは水素原子、炭素原子数１〜１０のアルキル基（例えば、イソプロピル基、ブチル基、２，４，４−トリメチルペンチル基）を表し、Ｒ′及びＲ″は炭素原子数１〜８のアルキル基（例えば、メチル基、エチル基、ｔ−ブチル基）を表す。
【００６２】
その他、米国特許第３，５８９，９０３号明細書、同第４，０２１，２４９号明細書、英国特許第１，４８６，１４８号明細書、特開昭５１−５１９３３号公報、同５０−３６１１０号公報、同５０−１１６０２３号公報、同５２−８４７２７号公報、特公昭５１−３５７２７号公報に記載されたポリフェノール化合物、米国特許第３，６７２，９０４号明細書に記載されたビスナフトール類、例えば、２，２′−ジヒドロキシ−１，１′−ビナフチル、６，６′−ジブロモ−２，２′−ジヒドロキシ−１，１′−ビナフチル等、更に、米国特許第３，８０１，３２１号明細書に記載されているようなスルホンアミドフェノールまたはスルホンアミドナフトール類、例えば、４−ベンゼンスルホンアミドフェノール、２−ベンゼンスルホンアミドフェノール、２，６−ジクロロ−４−ベンゼンスルホンアミドフェノール、４−ベンゼンスルホンアミドナフトール等も挙げることができいる。
上記に挙げた化合物以外に特願２００１−２１６６５９号明細書に記載された化合物も挙げられる。
本発明の光熱写真ドライイメージング材料に使用される還元剤の量は、有機銀塩や還元剤の種類、その他の添加剤によって変化するが、一般的には、有機銀塩１モル当たり０．０１モル乃至１０モルの範囲で用いられるが、さらに好ましくは、０．１モル乃至３モルの範囲である。
また、上述した還元剤は単独で用いても、２種以上を併用してもよい。
還元剤を感光性ハロゲン化銀及び有機銀塩粒子及び溶媒からなる感光乳剤溶液に添加混合する場合、塗布直前に添加することにより、塗布液に停滞する時間が短くなり、写真性能変動を小さくすることができるので好ましい場合がある。
また、還元剤には、補助剤として、欧州特許第１０９６３１０号明細書に記載されているトリフェニルフォスフィンオキサイド等のように還元剤の水酸基の水素と水素結合を形成し得る化合物を併用することも好ましい。
【００６３】
［省銀化剤］
本発明で用いる銀塩光熱写真ドライイメージング材料には省銀化剤を用いることができる。
省銀化剤とは、一定の銀画像濃度を得るために必要な銀量を低減化し得る化合物をいう。この低減化する機能の作用機構は種々考えられているが、現像銀の被覆力を向上させる機能を有する化合物が好ましい。ここで、現像銀の被覆力とは、銀の単位量当たりの光学濃度をいう。
省銀化剤としては、特願２０００−１９１０６２号明細書、特願２００１−１９２６９８号明細書に記載の化合物が好ましい例として挙げられる。
【００６４】
［バインダー］
光熱写真ドライイメージング材料に用いるのに好適なバインダーは、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。用いるバインダーは親水性であっても非親水性であってもよい。
光熱写真ドライイメージング材料の感光性層に用いるのに好ましいバインダーはポリビニルアセタール類であり、特に好ましいバインダーはポリビニルブチラールである。また、上塗り層や下塗り層、特に保護層やバックコート層等の非感光層に対しては、より軟化温度の高いポリマーであるセルロースエステル類、特にトリアセチルセルロース、セルロースアセテートブチレート等のポリマーが好ましい。なお、必要に応じて、上記のバインダーは２種以上を組み合わせて用いうる。
このようなバインダーは、バインダーとして機能するのに効果的な範囲で用いられる。効果的な範囲は当業者が容易に決定しうる。例えば、感光性層において少なくとも有機銀塩を保持する場合の指標としては、バインダーと有機銀塩との割合は１５：１〜１：２、特に８：１〜１：１の範囲が好ましい。また、感光性層のバインダー量は１．５〜６ｇ／ｍ²であることが好ましい。更に好ましくは１．７〜５ｇ／ｍ²である。１．５ｇ／ｍ²未満では未露光部の濃度が大幅に上昇し、使用に耐えない場合がある。
【００６５】
（有機性ゲル化剤）
感光性層には有機性ゲル化剤を含有せしめてもよい。なお、ここででいう有機性ゲル化剤とは、例えば、多価アルコール類のように有機液体に添加することにより、その系に降伏値を付与し、系の流動性を消失あるいは低下させる機能を有する化合物をいう。
【００６６】
（水系塗布）
塩光熱写真ドライイメージング材料の感光層を形成する塗布液が水性分散されたポリマーラテックスを含有する場合、塗布液中の全バインダの５０質量％以上が水性分散されたポリマーラテックスであることが好ましい。
本発明に係る「ポリマーラテックス」とは水不溶性の疎水性ポリマーが微細な粒子として水溶性の分散媒中に分散したものである。分散状態としてはポリマーが分散媒中に乳化されているもの、乳化重合されたもの、ミセル分散されたものあるいはポリマー分子中に部分的に親水的な構造を持ち分子鎖自身が分子状分散したものなどいずれでもよい。
分散粒子の平均粒径は１〜５００００ｎｍ、より好ましくは５〜１０００ｎｍ程度の範囲が好ましい。分散粒子の粒径分布に関しては特に制限はなく、広い粒径分布を持つものでも単分散の粒径分布を持つものでもよい。
ポリマーラテックスとしては、通常の均一構造のポリマーラテックス以外、いわゆるコア／シェル型のラテックスでもよい。この場合コアとシェルはガラス転移温度を変えると好ましい場合がある。ポリマーラテックスの最低造膜温度（ＭＦＴ）は、−３０〜９０℃であることが好ましく、更に好ましくは０〜７０℃程度である。また、最低造膜温度をコントロールするために造膜助剤を添加してもよい。
造膜助剤は可塑剤ともよばれポリマーラテックスの最低造膜温度を低下させる有機化合物（通常有機溶媒）であり、例えば「合成ラテックスの化学（室井宗一著、高分子刊行会発行（１９７０））」に記載されている。
【００６７】
ポリマーラテックスに用いられるポリマー種としては、アクリル樹脂、酢酸ビニル樹脂、ポリエステル樹脂、ポリウレタン樹脂、ゴム系樹脂、塩化ビニル樹脂、塩化ビニリデン樹脂、ポリオレフィン樹脂、またはこれらの共重合体などがある。ポリマーとしては直鎖のポリマーでも枝分かれしたポリマーでも、また架橋されたポリマーでもよい。また、ポリマーとしては単一のモノマーが重合したいわゆるホモポリマーでもよいし、２種以上のモノマーが重合したコポリマーでもよい。コポリマーの場合はランダムコポリマーでもブロックコポリマーでもよい。ポリマーの分子量は数平均分子量で５０００〜１００００００、好ましくは１００００〜１０００００程度が好ましい。分子量が小さすぎるものは感光層の力学強度が不十分であり、大きすぎるものは製膜性が悪く好ましくない。
ポリマーラテックスは２５℃、６０％ＲＨでの平衡含水率が０．０１〜２質量％以下のものが好ましく、更に好ましくは、０．０１〜１質量％のものである。平衡含水率の定義と測定法については、例えば「高分子工学講座１４、高分子材料試験法（高分子学会編、地人書館）」などを参考にすることができる。
【００６８】
ポリマーラテックスの具体例としては、例えば、メチルメタクリレート／エチルアクリレート／メタクリル酸コポリマーのラテックス、メチルメタクリレート／２−エチルヘキシルアクリレート／スチレン／アクリル酸コポリマーのラテックス、スチレン／ブタジエン／アクリル酸コポリマーのラテックス、スチレン／ブタジエン／ジビニルベンゼン／メタクリル酸コポリマーのラテックス、メチルメタクリレート／塩化ビニル／アクリル酸コポリマーのラテックス、塩化ビニリデン／エチルアクリレート／アクリロニトリル／メタクリル酸コポリマーのラテックスなどが挙げられる。
これらのポリマーは単独で用いてもよいし、必要に応じて２種以上ブレンドして用いてもよい。ポリマーラテックスのポリマー種としては、アクリレートまたはメタクリレート成分のごときカルボン酸成分を０．１〜１０質量％程度含有するものが好ましい。
更に、必要に応じて全バインダの５０質量％以下の範囲でゼラチン、ポリビニルアルコール、メチルセルロース、ヒドロキシプロピルセルロース、カルボキシメチルセルロース、ヒドロキシプロピルメチルセルロースなどの親水性ポリマーを添加してもよい。これらの親水性ポリマーの添加量は前記感光層の全バインダの３０質量％以下が好ましい。
【００６９】
感光層形成用塗布液の調製において、有機銀塩と水性分散されたポリマーラテックスの添加の順序は、いずれが先であってもよいし、同時に添加してもよいが、好ましくは、ポリマーラテックスが後である。
更に、ポリマーラテックス添加前に有機銀塩、更には還元剤が混合されていることが好ましい。
また、有機銀塩とポリマーラテックスを混合した後、経時させる温度が低すぎると塗布面状が損なわれ、高すぎるとかぶりが上昇する問題があるので、混合後の塗布液は３０℃〜６５℃で上記時間経時されることが好ましい。更には３５℃〜６０℃で経時させることが好ましく、特には３５℃〜５５℃で経時されることが好ましい。このように温度を維持するには塗布液の調液槽等を保温すればよい。
感光層形成用塗布液の塗布は有機銀塩と水性分散されたポリマーラテックスを混合した後、３０分〜２４時間経過した塗布液を用いるのが好ましく、更に好ましくは、混合した後、６０分〜１２時間経過させることであり、特に好ましくは、１２０分〜１０時間経過した塗布液を用いることである。
ここで、「混合した後」とは、有機銀塩と水性分散されたポリマーラテックスを添加し、添加素材が均一に分散された後を言う。
【００７０】
［架橋剤］
架橋剤を上記バインダーに対し用いることにより膜付きがよくなり、現像ムラが少なくなることは知られているが、保存時のカブリ抑制や、現像後のプリントアウト銀の生成を抑制する効果もある。
架橋剤としては、従来写真感材用として使用されている種々の架橋剤、例えば、特開昭５０−９６２１６号公報に記載されているアルデヒド系、エポキシ系、エチレンイミン系、ビニルスルホン系、スルホン酸エステル系、アクリロイル系、カルボジイミド系、シラン化合物系の架橋剤を用いうるが、好ましいのは以下に示す、イソシアネート系化合物、シラン化合物、エポキシ化合物または酸無水物である。
好適なものの一つである下記一般式〔８〕で表されるイソシアネート系架橋剤及びチオイソシアネート系架橋剤について次に説明する。
【００７１】
一般式〔８〕
Ｘ＝Ｃ＝Ｎ−Ｌ−（Ｎ＝Ｃ＝Ｘ）ｖ
式中、ｖは１または２であり、Ｌはアルキレン、アルケニレン、アリーレン基またはアルキルアリーレン基でありうる２価または３価の連結基であり、Ｘは酸素または硫黄原子である。
なお、上記一般式〔８〕で表される化合物において、アリーレン基のアリール環は置換基を有し得る。好ましい置換基の例は、ハロゲン原子（例えば、臭素原子または塩素原子）、ヒドロキシ基、アミノ基、カルボキシル基、アルキル基およびアルコキシ基である。
【００７２】
上記イソシアネート系架橋剤は、イソシアネート基を少なくとも２個有しているイソシアネート類及びその付加体（アダクト体）であり、更に、具体的には、脂肪族ジイソシアネート類、環状基を有する脂肪族ジイソシアネート類、ベンゼンジイソシアネート類、ナフタレンジイソシアネート類、ビフェニルイソシアネート類、ジフェニルメタンジイソシアネート類、トリフェニルメタンジイソシアネート類、トリイソシアネート類、テトライソシアネート類、これらのイソシアネート類の付加体、例えば、イソシアネート類と２価または３価のポリアルコール類との付加体が挙げられる。
具体例としては、特開昭５６−５５３５号公報の１０頁から１２頁に記載されているイソシアネート化合物が挙げられ、これらを利用することができる。
なお、イソシアネートとポリアルコールのアダクト体は、特に、層間接着をよくし、層の剥離や画像のズレ及び気泡の発生を防止する能力が高い。かかるイソシアネートは光熱写真材料のどの部分に置かれてもよい。例えば、支持体中（特に支持体が紙の場合、そのサイズ組成中に含ませることができる）、感光層、表面保護層、中間層、アンチハレーション層、下引き層等の支持体の感光層側の任意の層に添加でき、これらの層の中の１層または２層以上に添加することができる。
また、本発明において使用することが可能なチオイソシアネート系架橋剤としては、上記のイソシアネート類に対応するチオイソシアネート構造を有する化合物も有用である。
本発明において使用される上記架橋剤の量は、銀１モルに対して０．００１〜２モル、好ましくは０．００５から０．５モルの範囲である。
上記のように、用いるイソシアネート化合物及びチオイソシアネート化合物は、上記の架橋剤として機能する化合物であることが好ましいが、上記の一般式〔８〕においてｖが０、即ち、当該官能基を一つのみ有する化合物であってもよい結果がえられる。
【００７３】
架橋剤として使用できるシラン化合物の例としては、特願平１２−０７７９０４号明細書に開示されている化合物が挙げられる。
【００７４】
エポキシ系架橋剤はエポキシ基を１個以上有するエポキシ化合物であればよく、エポキシ基の数、分子量、その他に制限はない。エポキシ基はエーテル結合やイミノ結合を介してグリシジル基として分子内に含有されることが好ましい。また、エポキシ化合物はモノマー、オリゴマー、ポリマー等のいずれであってもよく、分子内に存在するエポキシ基の数は通常１〜１０個程度、好ましくは２〜４個である。エポキシ化合物がポリマーである場合は、ホモポリマー、コポリマーのいずれであってもよく、その数平均分子量Ｍｎの特に好ましい範囲は２０００〜２００００程度である。
エポキシ化合物は、感光層、表面保護層、中間層、アンチハレーション層、下引き層等の支持体の感光層側の任意の層に添加でき、これらの層の中の１層または２層以上に添加することができる。また、併せて、支持体の感光層と反対側の任意の層に添加することができる。なお、両面に感光層が存在する銀塩光熱写真ドライイメージング材料ではいずれの層であってもよい。
【００７５】
架橋剤として用いることができる酸無水物は下記の構造式で示される酸無水物基を少なくとも１個有する化合物である。
−ＣＯ−Ｏ−ＣＯ−
酸無水物はこのような酸無水基を１個以上有するものであればよく、酸無水基の数、分子量、その他に制限はないが、一般式〔Ｂ〕で表される化合物が好ましい。
【００７６】
【化６】

一般式〔Ｂ〕において、Ｚは単環または多環系を形成するのに必要な原子群を表す。
Ｚで形成される環は未置換であってもよく、置換されていてもよい。置換基の例には、アルキル基（例えば、メチル基、エチル基、ヘキシル基等）、アルコキシ基（例えば、メトキシ基、エトキシ基、オクチルオキシ基等）、アリール基（例えば、フェニル基、ナフチル基、トリル基等）、ヒドロキシ基、アリールオキシ基（例えば、フェノキシ基等）、アルキルチオ基（例えば、メチルチオ基、ブチルチオ基等）、アリールチオ基（例えば、フェニルチオ基等）、アシル基（例えば、アセチル基、プロピオニル基、ブチリル基等）、スルホニル基（例えば、メチルスルホニル基、フェニルスルホニル基等）、アシルアミノ基、スルホニルアミノ基、アシルオキシ基（例えば、アセトキシ基、ベンゾキシ基等）、カルボキシル基、シアノ基、スルホ基、アミノ基が含まれる。置換基としては、ハロゲン原子を含まないものが好ましい。
これらの酸無水物は、１種のみを用いても２種以上を併用してもよい。その添加量は特に制限はないが、１×１０^-6〜１×１０^-2モル／ｍ²の範囲が好ましく、より好ましくは１×１０^-5〜１×１０^-3モル／ｍ²の範囲である。
本発明において酸無水物は、感光層、表面保護層、中間層、アンチハレーション層、下引き層等の支持体の感光層側の任意の層に添加でき、これらの層の中の１層または２層以上に添加することができる。また、前記エポキシ化合物と同じ層に添加すしてもよい。
光熱写真ドライイメージング材料は、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粒子、還元剤及び必要に応じて銀の色調を調整する色調剤を通常（有機）バインダーマトリックス中に分散した状態で含有していることが好ましい。
【００７７】
［調色剤］
用いるのに好適な色調剤の例は、ＲＤ１７０２９号、米国特許第４，１２３，２８２号明細書、同第３，９９４，７３２号明細書、同第３，８４６，１３６号明細書および同第４，０２１，２４９号明細書に開示されており、例えば、次のものがある。
イミド類（例えば、スクシンイミド、フタルイミド、ナフタールイミド、Ｎ−ヒドロキシ−１，８−ナフタールイミド等）；メルカプタン類（例えば、３−メルカプト−１，２，４−トリアゾール等）；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、フタラジノン、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−フタラジンジオン等）；フタラジンとフタル酸類（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等）の組み合わせ；フタラジン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の無水物等）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等が挙げられる。特に好ましい色調剤としてはフタラジノンまたはフタラジンとフタル酸類、フタル酸無水物類の組み合わせである。
なお、従来、医療診断用の出力画像の色調に関しては、冷調の画像調子の方が、レントゲン写真の判読者にとってより的確な記録画像の診断観察結果が得やすいといわれている。ここで、冷調な画像調子とは、純黒調もしくは黒画像が青味を帯びた青黒調であり、温調な画像調子とは、黒画像が褐色味を帯びた温黒調であることをいう。
【００７８】
色調に関しての用語「より冷調」及び「より温調」は、最低濃度Ｄｍｉｎ及び光学濃度Ｄ＝１．０における色相角ｈａｂにより求められる。色相角ｈａｂは国際照明委員会（ＣＩＥ）が１９７６年に推奨した知覚的にほぼ均等な歩度を持つ色空間であるＬ^*ａ^*ｂ^*色空間の色座標ａ^*、ｂ^*を用いて次の式によって求める。
ｈａｂ＝ｔａｎ^-1（ｂ^*／ａ^*）
本発明において、好ましいｈａｂの範囲は１８０°＜ｈａｂ＜２７０°であり、更に好ましくは２００°＜ｈａｂ＜２７０°、最も好ましくは２２０°＜ｈａｂ＜２６０°である。
本発明において、好ましいｈａｂの範囲は１８０°＜ｈａｂ＜２７０°であり、さらに好ましくは２００°＜ｈａｂ＜２７０°、最も好ましくは２２０°＜ｈａｂ＜２６０°である。
【００７９】
［マット剤］
光熱写真ドライイメージング材料の感光層側や支持体をはさみ感光層の反対側に設けた非感光層の表面層に、現像前の取り扱いや熱現像後の画像の傷つき防止のためマット剤を含有することが好ましく、バインダーに対し０．１〜３０質量％含有することが好ましい。
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、無機物である、スイス特許第３３０，１５８号明細書等に記載のシリカ、仏国特許第１，２９６，９９５号明細書等に記載のガラス粉、英国特許第１，１７３，１８１号明細書等に記載のアルカリ土類金属、カドミウム、亜鉛等の炭酸塩等、有機物である、米国特許第２，３２２，０３７号明細書等に記載の澱粉、ベルギー特許第６２５，４５１号明細書、英国特許第９８１，１９８号明細書等に記載された澱粉誘導体、特公昭４４−３６４３号公報等に記載のポリビニルアルコール、スイス特許第３３０，１５８号明細書等に記載のポリスチレン或いはポリメタアクリレート、米国特許第３，０７９，２５７号明細書等に記載のポリアクリロニトリル、米国特許第３，０２２，１６９号明細書等に記載されたポリカーボネートをマット剤として用いることができる。
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。また、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。
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。
粒子サイズ分布の変動係数（％）＝〔（粒径の標準偏差）／（粒径の平均値）〕×１００
マット剤の添加は、予め塗布液中に分散させて塗布する方法で行ってもよく、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して行ってもよい。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。
【００８０】
光熱写真ドライイメージング材料に用いる支持体の素材としては各種高分子材料、ガラス、ウール布、コットン布、紙、金属（例えば、アルミニウム等）等が挙げられるが、情報記録材料としての取り扱いの点を考慮すると、可撓性のあるシートまたはロールに加工できるものが好適である。
従って、支持体としては、プラスチックフィルム（例えば、セルロースアセテートフィルム、ポリエステルフィルム、ポリエチレンテレフタレートフィルム、ポリエチレンナフタレートフィルム、ポリアミドフィルム、ポリイミドフィルム、セルローストリアセテートフィルムまたはポリカーボネートフィルム等）が好ましく、本発明においては２軸延伸したポリエチレンテレフタレートフィルムが特に好ましい。
支持体の厚みは好ましくは５０〜３００μｍであり、７０〜１８０μｍが好ましい。
【００８１】
［帯電防止剤］
光熱写真ドライイメージング材料には、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、下引層，バッキング層、感光性層と下引の間の層などに含有させることが好ましい。導電性化合物としては米国特許第５，２４４，７７３号明細書カラム１４〜２０に記載された導電性化合物が好ましく用いられる。
【００８２】
［層構成］
光熱写真ドライイメージング材料は支持体上に少なくとも１層の感光層を有している。支持体上に感光層のみを形成してもよいが、感光層の上に少なくとも一層の非感光層を形成するのが好ましい。例えば、感光層の上には感光層を保護する目的で保護層が、また、支持体の反対の面には光熱写真ドライイメージング材料間での、あるいは光熱写真ドライイメージング材料とロール間でのくっつきを防止するために、バックコート層が設けられるのが好ましい。これらの保護層やバックコート層に用いるバインダーとしては、熱現像層よりもガラス転位点が高く、擦り傷や、変形の生じにくいポリマー、例えば、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等のポリマーが、前記のバインダーのなかから選ばれる。
なお、階調調整等のために、感光層を支持体の一方の側に２層以上または支持体の両側に１層以上設置してもよい。
【００８３】
［染料］
光熱写真ドライイメージング材料においては、感光層を透過する光の量または波長分布を制御するために感光層と同じ側または反対の側にフィルター層を形成するか、感光層に染料または顔料を含有させることが好ましい。
染料としては、光熱写真ドライイメージング材料の感色性に応じて種々の波長領域の光を吸収する公知の化合物が使用できる。
例えば、光熱写真ドライイメージング材料を赤外光による画像記録材料とする場合には、特願平１１−２５５５５７号明細書に開示されているようなチオピリリウム核を有するスクアリリウム染料（以下、チオピリリウムスクアリリウム染料ということがある。）及びピリリウム核を有するスクアリリウム染料（以下、ピリリウムスクアリリウム染料ということがある。）（以下、これらを併せてクロコニウム染料という。）また、スクアリリウム染料に類似したチオピリリウムクロコニウム染料、ピリリウムクロコニウム染料を使用することも好ましい。
なお、スクアリリウム染料とは、分子構造中に１−シクロブテン−２−ヒドロキシ−４−オンを有する染料であり、クロコニウム染料とは分子構造中に１−シクロペンテン−２−ヒドロキシ−４，５−ジオンを有する染料である。ここで、ヒドロキシ基は解離していてもよい。
染料としては特開平８−２０１９５９号公報に記載の化合物も好ましい。
【００８４】
［塗布技術］
銀塩光熱写真ドライイメージング材料は、上述した各構成層の素材を溶媒に溶解または分散させた塗布液を作り、それら塗布液を複数同時に重層塗布した後、加熱処理を行って形成されることが好ましい。ここで「複数同時に重層塗布」とは、各構成層（例えば、感光層、保護層）の塗布液を作製し、これを支持体へ塗布する際に各層個別に塗布、乾燥の繰り返しをするのではなく、同時に重層塗布を行い乾燥する工程も同時に行える状態にあいて各構成層を形成することを意味する。ここで同時に重層塗布するとは、下層中の全溶剤の残存量が７０質量％以下となる前に上層を設けることである。
【００８５】
各構成層を複数同時に重層塗布する方法には特に制限はなく、例えば、バーコーター法、カーテンコート法、浸漬法、エアーナイフ法、ホッパー塗布法、エクストリュージョン塗布法などの公知の方法を用いることができる。これらのうちより好ましくはエクストリュージョン塗布法と呼ばれる前計量タイプの塗布方式である。該エクストリュージョン塗布法はスライド塗布方式のようにスライド面での揮発がないため、精密塗布、有機溶剤塗布に適している。この塗布方法は感光層を有する側について述べたが、バックコート層を設ける際、下引きとともに塗布する場合についても同様である。
なお、本発明において、塗布銀量は、銀塩光熱写真ドライイメージング材料の使用目的に応じた適量を選ぶことが好ましいが、医療用画像を得ることを目的とする場合には、０．６ｇ／ｍ²以上２．５ｇ／ｍ²以下が好ましい。更には、０．８ｇ／ｍ²以上１．５ｇ／ｍ² 以下が好ましい。当該塗布銀量の内、ハロゲン化銀に由来するものは全銀量に対して２％〜１８％を占めることが好ましい、更には、５％〜１５％が好ましい。
また、０．０１μｍ以上（球相当換算粒径）のハロゲン化銀粒子を用いた場合の塗布密度は１×１０¹⁴個／ｍ²以上１×１０¹⁸個／ｍ²以下が好ましい。更には、１×１０¹⁵個／ｍ²以上１×１０¹⁷個／ｍ²以下が好ましい。
また、非感光性長鎖脂肪族カルボン酸銀を用いる場合、非感光性長鎖脂肪族カルボン酸銀の塗布密度は、用いた０．０１μｍ以上（球相当換算粒径）のハロゲン化銀粒子１個当り１×１０^-17ｇ以上１×１０^-15ｇ以下、更には、１×１０^-16ｇ以上１×１０^-14ｇ以下が好ましい。
上記のような範囲内の条件において塗布した場合には、一定塗布銀量当りの銀画像の光学的最高濃度、即ち、銀被覆量（カバーリング・パワー）及び銀画像の色調等の観点から好ましい結果が得られる。
【００８６】
［現像条件］
銀塩光熱写真ドライイメージング材料の現像条件は使用する機器、装置あるいは手段に依存して変化するが、典型的には、像様に露光した光熱写真ドライイメージング材料を加熱することにより行う。露光後に得られた潜像は、中程度の高温（例えば、約８０〜２００℃、好ましくは約１００〜２００℃）で十分な時間（一般には約１秒〜約２分間）光熱写真材料を加熱することにより現像することができる。
加熱温度が８０℃以下では短時間に十分な画像濃度が得られず、また、２００℃以上ではバインダーが溶融し、ローラーへの転写するなど、画像そのものだけでなく搬送性や、現像機等へも悪影響を及ぼす。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により銀画像を生成する。この反応過程は、外部からの水等の処理液の一切の供給なしに進行することができる。
加熱する機器、装置あるいは手段としては、ホットプレート、アイロン、ホットローラー、炭素または白色チタン等を用いた熱発生器という典型的な加熱手段を用いることができる。保護層が設けられた銀塩光熱写真ドライイメージング材料は、保護層を有する側の面を加熱手段と接触させて加熱するのが、均一な加熱を行う上で、また、熱効率、作業性の点などから好ましく、該面をヒートローラに接触させながら搬送し加熱処理して現像することが好ましい。
なお、銀塩光熱写真ドライイメージング材料は、加熱温度１２３℃、現像時間１３．５秒で熱現像して得られる画像が、拡散濃度（Ｙ軸）と常用対数露光量（Ｘ軸）の単位長の等しい直交座標上に示される特性曲線において、拡散光での光学濃度で０．２５〜２．５の平均階調が２．０〜４．０であることが好ましい。感光性ハロゲン化銀粒子の感度や塗布銀量、層構成等の調整によりこのような階調にすると、診断認識性の高い画像を得ることが可能となる。
［露光］
本発明において、銀塩写真感光材料は、放射線エネルギーの照射によって本発明の放射線像変換パネルが発する蛍光によって露光される。用いる銀塩写真感光材料の感色性は放射線像変換パネルが発する蛍光の波長に対して適切なものとすることが望ましい。
【００８７】
［溶剤含量］
銀塩光熱写真ドライイメージング材料は、現像時において、溶剤を５〜１０００ｍｇ／ｍ²の範囲で含有していることが好ましい。さらに好ましくは、１００〜５００ｍｇの範囲である。このようにすることにより、高感度、低かぶり、最高濃度を得ることができる。
用いることができる溶剤としては、例えば、アセトン、メチルエチルケトン、イソフォロン等のケトン類、メチルアルコール、エチルアルコール、イソプロピルアルコール、シクロヘキサノール、ベンジルアルコール等のアルコール類、エチレングリコール、ジエチレングリコール、トリエチレングリコール、プロピレングリコール、ヘキシレングリコール等のグリコール類、エチレングリコールモノメチルエーテル、ジエチレングリコールモノエチルエーテル等のエーテルアルコール類、イソプロピルエーテル等のエーテル類、酢酸エチル、酢酸ブチル等のエステル類、塩化メチレン、ジクロルベンゼン等の塩化物類、炭化水素類等が挙げられる。その他、水、ホルムアミド、ジメチルホルムアミド、トルイジン、テトラヒドロフラン、酢酸等も用いることができる。しかし、用いることができる溶剤はこれらに限定されるものではない。また、これらの溶剤は、単独で、または、数種類組み合わせて用いることができる。
なお、銀塩光熱写真ドライイメージング材料中に含有する上記溶剤は、塗布工程後の乾燥工程等における温度条件等を変化させることによって含有させることができる。また、その含有量は、その条件を変えることによって調整できる。
当該溶剤の含有量は、含有させた溶剤を検出するために適した条件下においてガスクロマトグラフィーで測定できる。
【００８８】
【実施例】
以下に、本発明を実施例により具体的に説明するが、本発明はこれらの実施例によって限定されるものではない。
実施例１
（蛍光体粒子Ｚ１〜Ｚ３の調製）
水にイットリウムＹの硝酸塩、ガドリニウムＧｄの硝酸塩、ユウロピウムＥｕの硝酸塩を、イットリウムＹ、ガドリニウムＧｄ、ユウロピウムＥｕの質量比が表１に示す割合になるように混合し、溶解した水溶液を８５℃、１．０時間加熱し、過酸化水素（３０％）１．５ｍｌと尿素５００ｇを含む水溶液を添加してさらに加熱し、希土類元素の塩基性炭酸塩の球状粒子を析出させた。次いで、析出した混合希土類元素の塩基性炭酸塩を固液分離し、希土類元素の塩基性炭酸塩の蛍光体の球状粒子を得た。この塩基性炭酸塩の球状粒子をさらに酸化性雰囲気中７５０℃で焼成し、希土類酸化物からなる球形微粒子蛍光体Ｚ１〜Ｚ３を得た。得られた球形微粒子蛍光体Ｚ１〜Ｚ３の結晶子サイズ、平均粒径及び蛍光波長を表１に併せて示す。
【００８９】
【表１】

【００９０】
（放射線像変換パネルＰ１〜Ｐ３の製造）
―蛍光体層形成用塗布液の調製―
球形微粒子蛍光体Ｚ１ ２００ｇ、結合剤〔ポリウレタン系熱可塑性エラストマーデモラックＴＰＫＬ−５−２６２５（固形分４０％）（住友バイエルウレタン株式会社製）〕２０ｇ、ニトロセルロース（硝化度１１．５％）２ｇにメチルエチルケトン溶媒を加え、プロペラ型ミキサーで分散させて粘度２５ｐｓ（２５℃）の蛍光体層形成用塗布液を調製した（結合剤／蛍光体比＝１／２２）。
―下塗層形成用塗布液の調製―
軟質アクリル樹脂（固形分）９０ｇ、ニトロセルロース６０ｇをメチルエチルケトンを加えて分散、混合して粘度３〜６ｐｓ（２５℃）の分散液を調製した。
―放射線像変換パネルＰ１〜Ｐ３の作製―
二酸化チタンを練り込んだ厚さ２２０μｍのポリエチレンテレフタレートベース（支持体）をガラス板上に水平に置き、上記下塗り層形成用塗布液をドクタープレードを用いて支持体上に均一塗布した後、２５℃から１００℃に徐々に昇温させて塗布膜の乾操を行い、支持体上に下塗り層を形成した。塗布膜の厚さは１５μｍであった。
この上に上記の蛍光体層形成用塗布液をドクタープレードを用いて膜厚１５０μｍの厚みで均一に塗布乾燥し、次いで、圧縮を行った。圧縮はカレンダーロールを用いて３００Ｋｇｗ／ｃｍ²の圧力、８０℃の温度で行った。この庄縮後、特開平６−７５０９７号公報の実旋例１に記載の方法で厚さ３μｍの透明保護層を形成し、放射線像変換パネルＰ１を作製た。
球形微粒子蛍光体Ｚ１に代え、球形微粒子蛍光体Ｚ２、Ｚ３を用いた以外は放射線像変換パネルＰ１と同様にして放射線像変換パネルＰ２およびＰ３を作製した。
【００９１】
（感光材料Ｆ１００の作成）
〈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の光学濃度で０．１７０（コニカ株式会社製デンシトメータＰＤＡ−６５にて測定）に青色着色したポリエチレンテレフタレート（ＰＥＴ）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して下引層Ａ−１を形成し、また、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して下引層Ｂ−１を形成した。
《下引塗布液ａ−１》

水で１Ｌに仕上げる
《下引塗布液ｂ−１》

水で１Ｌに仕上げる
引き続き、下引層Ａ−１及び下引層Ｂ−１の上表面に、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になるよう塗設乾燥して下引上層Ａ−２を形成し、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になるように塗設乾燥して帯電防止機能をもつ下引上層Ｂ−２を形成した。
【００９２】
《下引上層塗布液ａ−２》
ゼラチン ０．４ｇ／ｍ²になる質量
Ｃ−１ ０．２ｇ
Ｃ−２ ０．２ｇ
Ｃ−３ ０．１ｇ
シリカ粒子（平均粒径３μｍ） ０．１ｇ
水で１Ｌに仕上げる
《下引上層塗布液ｂ−２》
Ｃ−４ ６０ｇ
Ｃ−５を成分とするラテックス液（固形分２０％） ８０ｇ
硫酸アンモニウム ０．５ｇ
Ｃ−６ １２ｇ
ポリエチレングリコール（重量平均分子量６００） ６ｇ
水で１Ｌに仕上げる
【００９３】
【化７】

【００９４】
【化８】

【００９５】
〈バック面側の塗布〉
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（ＥａｓｔｍａｎＣｈｅｍｉｃａｌ社、ＣＡＢ３８１−２０）８４．２ｇおよびポリエステル樹脂（Ｂｏｓｔｉｃ社、ＶｉｔｅｌＰＥ２２００Ｂ）４．５ｇを添加し溶解した。次に、得られた溶液に、０．３０ｇの赤外染料−１を添加し、さらにメタノール４３．２ｇに溶解したフッ素系活性剤（旭硝子社、サーフロンＫＨ４０）４．５ｇとフッ素系活性剤（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６４Ｘ６０００）を７５ｇ添加、攪拌しバック面側用の塗布液を調製した。
【００９６】
【化９】

このように調製したバック面側用の塗布液を、下引上層の上に乾燥膜厚が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。乾燥は乾燥温度１００℃、露天温度１０℃の乾燥風を用いて５分間かけて行った。
【００９７】
〈感光層面側の塗布〉
《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
化合物（Ａ）：ＨＯ（ＣＨ₂ＣＨ₂Ｏ）_ｎ−（ＣＨ（ＣＨ₃）ＣＨ₂Ｏ）₁₇−（ＣＨ₂ＣＨ₂Ｏ）_ｍＨ（ｍ＋ｎ＝５〜７）
【００９８】
特公昭５８−５８２８８号公報、同５８−５８２８９号公報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）全量を温度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。ｐＡｇの調整は（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）の全量を温度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、ハロゲン化銀乳剤を得た。
この乳剤は平均粒子サイズ０．０５８μｍ、粒子サイズ分布の変動係数１２％、（１００）面比率９２％の単分散立方体沃臭化銀粒子であった。
次に、上記乳剤に硫黄増感剤Ｓ−５（０．５％メタノール溶液）２４０ｍｌを加え、さらに、この増感剤の２／２０モル相当の金増感剤Ａｕ−５（０．５％エタノール溶液）を添加し５５℃にて１２０分間撹拌して化学増感を施し、感光性ハロゲン化銀乳剤Ａを得た。
【００９９】
《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、１．５Ｍ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℃に冷却して脂肪酸ナトリウム溶液を得た。上記の脂肪酸ナトリウム溶液の温度を５５℃に保ったまま、４５．３ｇの上記の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、１Ｍの硝酸銀溶液７０２．６ｍｌを２分間かけて添加し、１０分間攪拌し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。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（株式会社セイシン企業製）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乾燥済み粉末有機銀塩Ａを得た。
なお、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。
【０１００】
《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をメチルエチルケトン１４５７ｇ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を徐々に添加して十分に混合することにより予備分散液Ａを調製した。
【０１０１】
《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にて分散を行なうことにより感光性乳剤分散液１を調製した。
《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。
【０１０２】
【化１０】

【０１０３】
《赤外増感色素液Ａの調製》
１９．２ｍｇの赤外増感色素（ＳＤ−１）、１．４８８ｇの２−クロロ−安息香酸、２．７７９ｇの安定剤−２および３６５ｍｇの５−メチル−２−メルカプトベンズイミダゾールを３１．３ｍｌのＭＥＫに暗所にて溶解し赤外増感色素液Ａを調製した。
【０１０４】
【化１１】

【０１０５】
《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。
《添加液ｂの調製》
３．５６ｇのかぶり防止剤−２、３．４３ｇのフタラジンをＭＥＫ４０．９ｇに溶解し添加液ｂとした。
【０１０６】
【化１２】

【０１０７】
《感光層塗布液の調製》
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（５０ｇ）およびＭＥＫ１５．１１ｇを攪拌しながら２１℃に保温し、かぶり防止剤−１（１０％メタノール溶液）３９０μｌ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）４９４μｌを添加して２０分攪拌した。続いて、前記安定剤液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℃まで降温してさらに３０分攪拌した。１３℃に保温したまま、ポリビニルブチラール（Ｍｏｎｓａｎｔｏ社 Ｂｕｔｖａｒ Ｂ−７９）１３．３１ｇを添加して３０分攪拌した後、テトラクロロフタル酸（９．４質量％ＭＥＫ溶液）１．０８４ｇを添加して１５分間攪拌した。さらに攪拌を続けながら、１２．４３ｇの添加液ａ、１．６ｍｌのＤｅｓｍｏｄｕｒＮ３３００／モーベイ社社製の脂肪族イソシアネート（１０％ＭＥＫ溶液）、４．２７ｇの添加液ｂを順次添加し攪拌することにより感光層塗布液を得た。
【０１０８】
《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、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、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。
【０１０９】
《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（Ｅａｓｔｍａｎ Ｃｈｅｍｉｃａｌ社、ＣＡＢ１７１−１５）を９６ｇ、ポリメチルメタクリル酸（ローム＆ハース社、パラロイドＡ−２１）を４．５ｇ、下記ビニルスルホン化合物を１．５ｇ、ベンズトリアゾールを１．０ｇ、フッ素系活性剤（旭硝子社、サーフロンＫＨ４０）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。
ビニルスルホン化合物
（ＣＨ₂＝ＣＨＳＯ₂ＣＨ₂)₂ＣＨＯＨ
【０１１０】
《感光層面側の塗布》
前記感光層塗布液と表面保護層塗布液を押し出し（エクストルージョン）コーターを用いて同時に重層塗布することにより感光材料Ｆ１００を作製した。塗布は、感光層は塗布銀量１．９ｇ／ｍ²、表面保護層は乾燥膜厚で２．５μｍになるようにして行った。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。
【０１１１】
（感光材料Ｆ１０１Ａの作成）
《添加液ｃの調製》
５．０ｇの下記省銀化剤をＭＥＫ４５．０ｇに溶解し添加液ｃとした。
【０１１２】
【化１３】

《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、感光性乳剤分散液１（５０ｇ）およびＭＥＫ１５．１１ｇを攪拌しながら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分後にかぶり防止剤−１（１０％メタノール溶液）３９０μｌ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）４９４μｌを添加して１０分撹拌した後に上記の化学増感剤Ｓ−５の１／２０モル相当の金増感剤Ａｕ−５を添加し、さらに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℃まで降温してさらに３０分攪拌した。１３℃に保温したまま、ポリビニルブチラール（Ｍｏｎｓａｎｔｏ社 Ｂｕｔｖａｒ Ｂ−７９）１３．３１ｇを添加して３０分攪拌した後、テトラクロロフタル酸（９．４質量％ＭＥＫ溶液）１．０８４ｇを添加して１５分間攪拌した。さらに攪拌を続けながら、１２．４３ｇの添加液ａ、１．６ｍｌのＤｅｓｍｏｄｕｒＮ３３００／モーベイ社社製の脂肪族イソシアネート（１０％ＭＥＫ溶液）、４．２７ｇの添加液ｂを順次添加し攪拌することにより感光層塗布液Ａを得た。
【０１１３】
【化１４】

【０１１４】
《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（５０ｇ）およびＭＥＫ１５．１１ｇを攪拌しながら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分後にかぶり防止剤−１（１０％メタノール溶液）３９０μｌ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）４９４μｌを添加して１０分撹拌した後に上記の化学増感剤Ｓ−５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℃まで降温してさらに３０分攪拌した。１３℃に保温したまま、ポリビニルブチラール（Ｍｏｎｓａｎｔｏ社 Ｂｕｔｖａｒ Ｂ−７９）１３．３１ｇを添加して３０分攪拌した後、テトラクロロフタル酸（９．４質量％ＭＥＫ溶液）１．０８４ｇを添加して１５分間攪拌した。さらに攪拌を続けながら、１２．４３ｇの添加液ａ、１．６ｍｌのＤｅｓｍｏｄｕｒＮ３３００／モーベイ社社製の脂肪族イソシアネート（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。
【０１１５】
（感光材料Ｆ１０１Ａの作製）
感光層面側の塗布を下記の感光層面側塗布１０１Ａに代えた以外は、感光材料Ｆ１００と同様にして感光材料Ｆ１０１Ａを作製した。
《感光層面側塗布１０１Ａ》
感光層塗布液Ａ、感光層塗布液Ｂ、表面保護層塗布液を押し出し（エクストルージョン）コーターを用いて感光層２層および表面保護層１層の計３層を同時に重層塗布により形成した。塗布は、感光層塗布液Ａから形成される感光層ａは塗布銀量０．７ｇ／ｍ²、感光層塗布液Ｂから形成される感光層ｂは塗布銀量０．３ｇ／ｍ²、表面保護層は乾燥膜厚で２．５μｍになるようにして行った。その後、乾燥温度５０℃、露点温度１０℃の乾燥風を用いて、１０分間乾燥を行った。
（感光材料Ｆ１０１Ｂの作製）
感光層面側の塗布を下記の感光層面側塗布１０１Ｂに代えた以外は、感光材料Ｆ１００と同様にして感光材料Ｆ１０１Ｂを作製した。
《感光層面側塗布１０１Ｂ》
感光層塗布液Ａ、表面保護層塗布液を押し出し（エクストルージョン）コーターを用いて感光層ａおよび表面保護層１層の計２層を同時に重層塗布により形成した。また、支持体を挟んでこれら２層の反対側に、感光層塗布液Ｂ、表面保護層塗布液を押し出し（エクストルージョン）コーターを用いて感光層ｂおよび表面保護層１層の計２層を同時に重層塗布により形成した。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になるようにして行った。その後、乾燥温度５０℃、露点温度１０℃の乾燥風を用いて、１０分間乾燥を行った。
【０１１６】
（感光材料Ｆ１０２の作成）
《有機銀塩分散物の調製》
ステアリン酸７ｇ、アラキジン酸４ｇ、ベヘン酸３６ｇ、蒸留水８５０ｍｌに９０℃で激しく攪拌しながら１モル／リットル濃度のＮａＯＨ水溶液１８７ｍｌを添加し１２０分反応させ、１Ｎ−硝酸７１ｍｌを添加した後、５０℃に降温した。次いで、より激しく攪拌しながら硝酸銀２１ｇの水溶液１２５ｍｌを１００秒かけて添加し、そのまま２０分間放置した。その後、吸引濾過で固形分を濾別し、固形分を濾水の伝導度が３０μＳ／ｃｍになるまで水洗した。こうして得た固形分にＰＶＡ２０５（クラレ（株）社製ポリビニールアルコール）１０質量％水溶液１００ｇを添加し、さらに総質量２７０ｇとなるように水を加えたのち、自動乳鉢にて粗分散し、有機銀塩粗分散物を得た。
この有機銀塩粗分散物をナノマイザ（ナノマイザ（株）製）を用い衝突時の圧力９８．０７ＭＰａで分散し、有機銀塩分散物を得た。
得られた有機銀塩分散物に含まれる有機銀塩粒子は平均短径０．０４μｍ、平均長径０．８μｍ、変動係数３０％の針状粒子であった。
【０１１７】
《還元剤分散物の調製》
１，１−ビス（２−ヒドロキシ−３，５−ジメチルフェニル）−３，５，５−トリメチルヘキサン（還元剤）１００ｇとヒドロキシプロピルセルロース５０ｇに水８５０ｇを添加しよく混合してスラリーとした。該スラリーを平均直径０．５ｍｍのジルコニアビーズ８４０ｇと一緒にベッセルに入れ、分散機（１／４Ｇサンドグラインダーミル：アイメックス（株）製）にて５時間分散し還元剤分散物を得た。
《有機ポリハロゲン化物分散物の調製》
トリブロモメチルスルホニルベンゼン５０ｇ（０．１２７モル）とヒドロキシプロピルセルロース１０ｇに水９４０ｇを添加しよく混合してスラリーとした。該スラリーを平均直径０．５ｍｍのジルコニアビーズ８４０ｇと一緒にベッセルに入れ、分散機（サンドグラインダーミル：アイメックス（株）製）にて５時間分散し有機ポリハロゲン化物分散物を得た。
【０１１８】
《感光性ハロゲン化銀乳剤の調製》
水１０００ｍｌにフタル化ゼラチン２２ｇおよび臭化カリウム３０ｍｇを溶解して温度３５℃にてｐＨを５．０に合わせた後、硝酸銀１８．６ｇおよび硝酸アンモニウム０．９ｇを含む水溶液１５９ｍｌと臭化カリウムおよび沃化カリウムを９２：８のモル比で含む水溶液１５９ｍｌをｐＡｇ７．７に保ちながらコントロールダブルジェット法で１０分間かけて添加した。次いで、硝酸銀５５．４ｇおよび硝酸アンモニウム２ｇを含む水溶液４７６ｍｌおよび六塩化イリジウム酸二カリウムを１０μモル／リットル、臭化カリウムを１モル／リットル含む水溶液をｐＡｇ７．７に保ちながらコントロールダブルジェット法で３０分間かけて添加した後、４−ヒドロキシ−６−メチル−１，３，３ａ，７−テトラザインデン１ｇを添加し、さらにｐＨを下げて凝集沈降させ脱塩処理をした。その後、フェノキシエタノール０．１ｇを加え、ｐＨ５．９、ｐＡｇ８．２に調整し、沃臭化銀粒子（沃素含量コア８モル％、平均２モル％、平均サイズ０．０５μｍ、投影面積変動係数８％、（１００）面比率８５％の立方体粒子）を調製した。
こうして得たハロゲン化銀粒子を６０℃に昇温して銀１モル当たりチオ硫酸ナトリウム８５μモルと２，３，４，５，６−ペンタフルオロフェニルジフェニルホスフィンセレニド１１μモル、テルル化合物１５μモル、塩化金酸３μモル、チオシアン酸２７０μモルを添加し、１２０分間熟成した後、４０℃に急冷し、次いで、１００μモルの増感色素を添加し、３０分間撹拌後、３０℃に急冷して感光性ハロゲン化銀乳剤を得た。上記の３０℃をハロゲン化銀乳剤の調製温度とする。
【０１１９】
《乳剤層塗布液の調製》
有機銀塩分散物１３５０ｇ、ＰＶＡ２０５の２０質量％水溶液１４０ｍｌ、フタラジンの１０質量％水溶液３７ｍｌ、還元剤分散物２２０ｇ、有機ポリハロゲン化物分散物６１ｇを添加し、その後、ラックスターＬＡＣＳＴＡＲ３３０７Ｂ（大日本インキ化学工業（株）製；スチレンとブタジエンを主な共重合成分として含有するＳＢＲラテックス；分散粒子の平均粒径０．１〜０．１５μｍ、２５℃、６０％ＲＨ条件下でのポリマー平衡含水率０．６質量％）１１００ｇを混合し、その後、上記感光性ハロゲン化銀乳剤を１２０ｇ混合して乳剤層塗布液１〜８を調製した。尚、液ｐＨを１１モル／リットルの硫酸を用いてｐＨ５．０に調整し、乳剤層塗布液を得た。
【０１２０】
《乳剤面中間層塗布液の調製》
ＭＰ２０３（クラレ（株）社製変成ポリビニールアルコール）１００ｇを水９００ｍｌに溶解し、さらにスルホコハク酸ジ（２−エチルヘキシル）エステルナトリウム塩の５質量％の水溶液２ｍｌを添加し、乳剤面中間層塗布液を得た。
《乳剤面保護層塗布液の調製》
イナートゼラチン１４５ｇを１１１０ｍｌの温水に溶解したものに、２０質量％ポリエチルアクリレートラテックスを４００ｇ、１モル／リットル硫酸５７ｍｌ、スルホコハク酸ジ（２−エチルヘキシル）エステルナトリウム塩の５質量％水溶液１０ｍｌ、フタル酸の１０質量％メタノール溶液２８０ｍｌを添加し、乳剤面保護層塗布液を得た。
《乳剤面オーバーコート層塗布液の調製》
イナートゼラチン１２９ｇを１６５０ｍｌの温水に溶解したものに、ポリメチルメタクリレート微粒子（平均粒径サイズ２．５μｍ）を１２質量％含有するゼラチン分散物を１３０ｇ、１モル／リットル硫酸６５ｍｌ、スルホコハク酸ジ（２−エチルヘキシル）エステルナトリウム塩の５質量％水溶液２０ｍｌを添加した液１に対し、硫酸カリウムクロム（III）１２水和物の２質量％水溶液（硬膜剤）が０．３となるような流量比で用い乳剤面オーバーコート層塗布液を連続調製した。
【０１２１】
《バック層塗布液の調製》
固体塩基であるＮ，Ｎ′，Ｎ″，Ｎ″′−テトラエチルグアニジンと４−カルボキシスルフォニル−フェニルスルフォンとのモル比１：２の塩１０ｇをポリビニルアルコール１０ｇ、水８８ｇをサンドグラインダーミル（アイメックス（株）製）で分散し塩基液を得た。塩基性染料前駆体２．１ｇ、酸性物質７．９ｇ、０．１ｇ（１．９９０×１０^-4モル）のハレーション防止染料、酢酸エチル１０ｇを混合溶解した有機溶媒相をポリビニルアルコール１０ｇおよび水８０ｇからなる水溶液相に混合し、常温で乳化分散し染料液を得た（平均粒径２．５μｍ）。こうして得た塩基液３９ｇ、染料液２６ｇ、ポリビニルアルコール１０質量％水溶液３６ｇを混合しバック層塗布液を得た。
【０１２２】
【化１５】

【０１２３】
《バック層保護層塗布液》
ゼラチン２０ｇ、ポリメチルメタクリレート（平均粒径７μｍ）０．６ｇ、ドデシルベンゼンスルホン酸ナトリウム０．４ｇ、Ｘ−２２−２８０９（信越シリコーン（株）製シリコーン化合物）１ｇを水４８０ｇに溶解しバック層保護層塗布液を得た。
《下塗り塗布液Ａの調製》
ポリエステル共重合体分散物（ペスレジンＡ−５１５ＧＢ（固形分３０％）高松油脂（株）製）２００ｍｌにポリスチレン微粒子（平均粒径０．２μｍ）５０ｇ、界面活性剤Ａ（１質量％）２０ｍｌを添加し、これに蒸留水を加えて１０００ｍｌとして下塗り塗布液Ａとした。
【０１２４】
【化１６】

【０１２５】
《下塗り塗布液Ｂの調製》
蒸留水６８０ｍｌにスチレン−ブタジエン共重合体水分散物（スチレン／ブタジエン／イタコン酸＝４７／５０／３（質量比）、濃度３０質量％）２００ｍｌ、ポリスチレン微粒子（平均粒径２．５μｍ）０．１ｇを添加し、さらに蒸留水を加えて１０００ｍｌとして下塗り塗布液Ｂとした。
《下塗り塗布液Ｃの調製》
イナートゼラチン１０ｇを蒸留水５００ｍｌに溶解し、そこに特開昭６１−２００３３号に記載の酸化スズ−酸化アンチモン複合物微粒子の水分散物（４０質量％）４０ｇを添加して、これに蒸留水を加えて１０００ｍｌとして下塗り塗布液Ｃとした。
《下塗り支持体の作製》
下記青色染料で色味付けした厚さ１７５μｍの２軸延伸ポリエチレンテレフタレート支持体の片面（感光面）にコロナ放電処理を施した後、下塗り塗布液Ａをバーコータを用いてウエット塗布量が５ｍｌ／ｍ²になるように塗布して１８０℃で５分間乾燥した。乾燥膜厚は約０．３μｍであった。次いで、この裏面（バック面）にコロナ放電処理を施した後、下塗り塗布液Ｂをバーコータを用いてウエット塗布量が５ｍｌ／ｍ²、乾燥膜厚が約０．３μｍになるように塗布して１８０℃で５分間乾燥し、さらにその上に下塗り塗布液Ｃをバーコータを用いてウエット塗布量が３ｍｌ／ｍ²、乾燥膜厚が約０．０３μｍになるように塗布して１８０℃で５分間乾燥して下塗り支持体を作製した。
【０１２６】
【化１７】

【０１２７】
（感光材料Ｆ１０２の作製）
上記下塗り支持体のバック面に、バック層塗布液を８１０ｎｍの光学濃度が０．８となる量で、また、バック層保護層塗布液を５０ｇ／ｍ²でＳｔｅｐｈｅｎＦ．Ｋｉｓｔｌｅｒ、Ｐｅｔｅｒｔ Ｍ．Ｓｃｈｗｅｉｚｅｒ著「ＬＩＱＵＩＤ ＦＩＬＭ ＣＯＡＴＩＮＧ」（ＣＨＡＰＭＡＮ＆ａｍｐ；ＨＡＬＬ社刊、１９９７年）４２７頁のＦｉｇｕｒｅ １１ｂ．１に記載のコータと同様のコータで同時重層塗布した後、感光面に、支持体側から乳剤層塗布液が８２ｍｌ／ｍ²、乳剤面中間層塗布液が６．５ｍｌ／ｍ²、乳剤面保護層塗布液が１２．５ｍｌ／ｍ²、乳剤面オーバーコート層塗布液が１２ｍｌ／ｍ²となるように同時重層塗布し１０℃（露点０℃以下）のチルドゾーンを通過させた後、３０℃、４０％ＲＨ、風速２０ｍ／秒の風で乾燥した。こうして得られた感光材料Ｆ１０２の平滑度（Ｊ．ＴＡＰＰＩ紙パルプ試験法No.５記載の王研式平滑度測定を用いベック平滑度を調べた。）は乳剤面５９０秒、バック面８０秒であった。
【０１２８】
―本発明―
《露光処理》
（胸部ファントム）
１２０ｋＶｐ（３ｍｍ厚のアルミニウム透過フィルター装置）のＸ線源を用い、距離１４０ｃｍの位置に京都科学製胸部ファントムを置き、その後ろにグリッドレシオ８：１の散乱防止グリッド、その後ろに、表２に示す組み合わせで放射線像変換パネル（Ｐ１、Ｐ２及びＰ３）と感光材料（ＳＲ−ＥＳＣ（コニカ株式会社製）、ＣＭ−Ｈ（コニカ株式会社製）、ＳＤ−Ｐ（コニカ株式会社製）、Ｆ１００、Ｆ１０１Ａ、Ｆ１０１Ｂ及びＦ１０２）との組体を置き露光を行った。（ＡＣＲ規格１５６型マンモグラフィック・ファントム）
同様にしてＲＭＩ社製ＡＣＲ規格１５６型マンモグラフィック・ファントムを用いてマンモグラフィ画像を撮影した。
ＡＣＲ規格１５６型マンモグラフィック・ファントムには、繊維組織を模したナイロンファイバが６態、微小石灰化を模したアルミニウムスペックが５態、腫瘍を模したナイロン繊維が５態封入されている。
《現像処理》
〔Ｆ１００、Ｆ１０１Ａ、Ｆ１０１Ｂ及びＦ１０２の現像処理〕
ヒートドラムを有する自動現像機を用い、感光材料の保護層とドラム表面が接触するようにして、１１０℃で１５秒熱現像処理した。なお、現像処理は２３℃、５０％ＲＨに調湿した部屋で行った。
〔ＳＲ−ＥＳＣの現像処理〕
ＳＲＸ−５０２（コニカ株式会社製）を用いて現像処理を行った。
〔ＣＭ−Ｈの現像処理〕
ＳＲＸ−５０２（コニカ株式会社製）を用いて現像処理を行った。
〔ＳＤ−Ｐの現像処理〕
Ｄｒｙ Ｐｒｏ７２２（コニカ株式会社製）を用いて現像処理を行った。
【０１２９】
［胸部ファントム画像の評価］
胸部ファントムの仕上がり写真について目視で観察し、粒状性、鮮鋭性、銀色調を下記に示す評価基準で評価した。
［粒状性の評価基準］
Ａ：殆ど目立たない
Ｂ：若干目立つ
Ｃ：目立ち読影に若干支障あり
Ｄ：非常に目立ち読影に支障あり
［鮮鋭性の評価基準］
Ａ：非常にシャープ
Ｂ：良好だが僅かにボケがある
Ｃ：ボケが目立ち読影に若干支障あり
Ｄ：ボケにより読影困難
【０１３０】
［マンモグラフィ画像の評価］
繊維組織を模したナイロンファイバ、微小石灰化を模したアルミニウムスペック、腫瘍を模したナイロン繊維がいくつ見えるかで評価を行った。
―比較―
１２０ｋＶｐ（３ｍｍ厚のアルミニウム透過フィルター装置）のＸ線源を用い、距離１４０ｃｍの位置に京都科学製胸部ファントムを置き、その後ろにグリッドレシオ８：１の散乱防止グリッド、その後ろに、放射線像変換パネル（ＸＧ−Ｓ（コニカ株式会社製））と感光材料（ＳＲ−ＥＳＣ）との組体を置き露光を行い、前記と同様にして感光材料（ＳＲ−ＥＳＣ）を現像し、前記評価基準で胸部ファントム画像の評価を行った。
同様にしてＲＭＩ社製ＡＣＲ規格１５６型マンモグラフィック・ファントムを用いてマンモグラフィ画像を撮影した。なお、放射線像変換パネルと感光材料との組体として放射線像変換パネル（ＭＤ−１００（コニカ株式会社製））と感光材料（ＣＭ−Ｈ）との組体を用いた。前記と同様にして感光材料（ＣＭ−Ｈ）を現像し、前記評価基準でＡＣＲ規格１５６型マンモグラフィック・ファントム画像の評価を行った。
京都科学製胸部ファントムおよびＲＭＩ社製ＡＣＲ規格１５６型マンモグラフィック・ファントムをデジタイザー（ＲＥＧＩＵＳ ＭＯＤＥＬ１５０）で撮影し、その画像情報をレーザイメージャー（Ｄｒｙ Ｐｒｏ７２２）を用いてドライレーザ用フィルムＳＤ−Ｐ及びＦ１００に出力を行い、前記と同様にして感光材料（ＳＤ−Ｐ及びＦ１００）を現像し、前記評価基準で胸部ファントム画像及びＡＣＲ規格１５６型マンモグラフィック・ファントム画像の評価を行った。
得られた結果を併せて表２に示した。
【０１３１】
【表２】

表２から明らかなように、本発明の放射線像変換パネルと銀塩写真感光材料の組体は、比較に比べ、粒状性および鮮鋭性が向上しており医用画像の診断性が向上した。
【０１３２】
【発明の効果】
本発明によれば、高い鮮鋭性、粒状性が得られ、医用画像の診断性が向上する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for exposing a silver salt photographic light-sensitive material, and more particularly relates to a method for exposing a silver salt photographic light-sensitive material that is excellent in sharpness and graininess and provides high diagnostic properties.
[0002]
[Prior art]
In radiographic diagnosis in medicine, radiation transmitted through the human body is irradiated with a radiation image conversion panel represented by a fluorescent intensifying screen or the like, where it is converted into fluorescence, and an image is formed on the photosensitive material. Diagnosis is made based on this.
In the X-ray photography diagnosis, in order to avoid early detection of a lesion and misdiagnosis, it is required that the image has high sharpness and excellent graininess. The sharpness and graininess of the light-sensitive material itself are extremely important for enhancing the diagnostic ability because it affects the visibility of the image and the amount of information.
In normal X-ray diagnostics of the chest, a region where the tube voltage of the X-ray generator tube is 110 kVp or more is used. However, in the region where the tube voltage is 110 kVp or more, a substantial portion of the deterioration of graininess is X. This is based on the quantum motor of the line, and this quantum motor greatly deteriorates the graininess and image quality of the X-ray photograph.
As a phosphor that is a main material constituting the radiation image conversion panel, a phosphor mainly composed of a rare earth metal compound is used.
[0003]
Conventionally, as these phosphors, Gd₂O₂S: Tb and the like have been mainly used, and these were prepared by mixing a rare earth oxide and a sulfur compound, adding a flux, firing, and crushing. For this reason, the produced phosphor does not have a uniform particle shape, cracks occur in the crystal due to physical stress during pulverization or cooling, and the produced phosphor has an irregular particle shape due to a collapsed particle structure, In addition, the particle size distribution also widens. When a phosphor layer is formed using such a phosphor, the phosphor distribution in the radiation direction in the phosphor layer cannot be made uniform. For example, since the particle shape is not uniform, the phosphor is not uniformly dispersed, resulting in regions where the phosphor density is high and low, and a uniform amount of light cannot be obtained even if the intensity of irradiated radiation is equal. . Even if the phosphors can be dispersed uniformly, even if the intensity of the radiation is the same between the large and small portions of the phosphor particle size, the amount of emitted light will be different. Further, when the phosphors are not uniformly dispersed or when the particle shapes are not uniform, radiation scattering occurs randomly. For this reason, it becomes impossible to obtain light emission correctly according to the intensity of the irradiated radiation, resulting in blurring of the radiation image.
Moreover, the radiation image conversion panel manufactured in this way has a large deterioration of the X-ray quantum motor, and only an image with inferior sharpness and graininess can be obtained, which is not preferable for medical image diagnosis.
[0004]
In recent years, the amount of simple recording media called dry films that do not require wet processing has increased. Since the processing apparatus used for the development processing of these dry films does not require piping and does not discharge waste liquid, it does not become a complicated apparatus, so that it can be said that the dry film has very excellent handling properties. Further, the dry film has an excellent feature that the development processing time is short. However, direct recording on a dry film could not be performed using a conventional radiation image conversion panel.
Also, in recent years, laser beams that do not expose the photosensitive material directly with the fluorescence of the radiation image conversion panel, convert the information obtained from the radiation conversion panel into electrical signals, process them as digital data, and obtain a high amount of light. An apparatus called a so-called laser imager that exposes a photosensitive material using a laser has been widely used. By using these, it is possible to record on a dry film. However, when exposed with a laser imager, the image data is processed as a digital data by the sampling theorem, so that the loss of high-frequency data important for the sharpness of the image is lost. appear. In addition, the image quality is greatly affected by the shape and scanning of the laser beam, and the actual situation is that a high-quality image cannot always be obtained.
Therefore, dry films have not been suitable for obtaining images that require very high image quality, such as images of breasts.
[0005]
[Problems to be solved by the invention]
  Therefore, the object of the present invention is toIt is an object of the present invention to provide an exposure method for a silver salt photothermographic dry imaging material capable of obtaining high sharpness and graininess.
[0006]
[Means for Solving the Problems]
  The above object of the present invention is to
(1) Formula (Gd, M, Eu)₂O_ThreeSilver using organic silver salt particles, photosensitive silver halide particles, and a reducing agent using a radiation image conversion panel containing a phosphor having a crystallite size of 10 to 100 nm represented by (M represents a rare earth element) An exposure method comprising exposing a salt photothermographic dry imaging material.
(2)The rare earth element M is at least one selected from yttrium Y, neodymium Nd, terbium Tb, dysprosium Dy, holmium Ho, erbium Er, thulium Tm, and ytterbium Yb.Above (1)An exposure method according to 1.
(3)The phosphor is a particle having an average particle size of 0.2 to 5 μm.(1) or (2) aboveAn exposure method according to 1.
(4) Above (1) to (3)An image forming method, wherein the silver salt photothermographic dry imaging material exposed by the exposure method according to any one of the above is heated and developed at a temperature of 80 ° C. or higher and 200 ° C. or lower.
Achieved by:
[0007]
  Hereinafter, the present invention will be described in detail.
  First, the radiation image conversion panel of the present invention will be described.
  The radiation image conversion panel used in the present invention has a formula (Gd, M, Eu). ₂ O _Three (M represents a rare earth element) and contains a phosphor having a crystallite size of 10 to 100 nm.
  Formula (Gd, M, Eu) ₂ O _Three The phosphor represented by (M represents a rare earth element) is further selected from the group consisting of yttrium Y, neodymium Nd, terbium Tb, dysprosium Dy, holmium Ho, erbium Er, thulium Tm, and ytterbium Yb. It is preferable that the number is at least one. Also, the formula (Gd, M, Eu) ₂ O _Three In this case, it is preferable that gadolinium Gd is 40 to 95% by mass, M is 2 to 40% by mass, and europium Eu is 2 to 20% by mass.
  The phosphor used in the radiation image conversion panel is preferably phosphor particles having an average particle size of 0.2 to 5 μm.
  The phosphor particles emit light according to the intensity of incident radiation.
[0008]
The radiation image conversion panel is composed of a phosphor layer formed of the above-described phosphor. The phosphor layer can be, for example, a self-supporting phosphor layer, or on the support and its surface. It can also be a provided phosphor layer.
The radiation image conversion panel used in the present invention has a phosphor layer formed of a phosphor. The phosphor layer may be composed of only phosphor aggregates formed by vapor deposition or sintering, or may be composed of a phosphor and a binder that supports and disperses the phosphor. The above-mentioned aggregate can also be impregnated with a polymer substance in the gap.
The phosphor layer can be provided with a protective film made of a polymer film or an inorganic vapor-deposited film. A protective layer film can be provided on one surface or both surfaces of the self-supporting phosphor layer, and on the surface opposite to the support side of the phosphor layer provided on the surface of the support.
A phosphor having a light emission wavelength in a wavelength range of 300 to 900 nm is generally used, although it varies depending on the photosensitive characteristics of a silver salt photographic light-sensitive material exposed using a radiation image conversion panel. That is, electromagnetic waves (light) ranging from ultraviolet light to infrared light are output centering on visible light.
[0009]
In X-ray diagnosis in the medical field and other fields, for example, the wavelength that passes through the object of X-ray diagnosis is 1 mm (1 × 10^-Tenm) about X-rays are used. The wavelength and intensity of the X-ray are selected according to the material to be seen through. Radiation that has passed through human bodies, ships, aircraft members, etc. irradiates a radiation image conversion panel represented by fluorescent intensifying screens, etc., where it is converted to fluorescence, and an image is formed on the silver salt photographic light-sensitive material. Diagnosis is made based on
This X-ray is output from the radiation generator, and a fixed anode or a rotary anode X-ray tube is generally used as the anode of the radiation generator. The applied voltage to the anode of the X-ray tube is usually 10 kV to 300 kV. When used for medical purposes, the voltage applied to the anode of the X-ray tube is 20 kV to 150 kV.
[0010]
  In the present invention,Formula (Gd, M, Eu) ₂ O _Three A phosphor having a crystallite size of 10 to 100 nm represented by (M represents a rare earth element)A radiation image conversion panel is formed using the same. The phosphor particles having such a composition have a high radiation absorption rate, a high light emission efficiency, and a large amount of light emission, so that a radiation image with good granularity can be obtained.
  Formula (Gd, M, Eu) ₂ O _Three In the phosphor represented by (M represents a rare earth element),As the rare element M, yttrium Y,Neodymium NdWhen at least one of terbium Tb, dysprosium Dy, holmium Ho, erbium Er, thulium Tm, and ytterbium Yb is used, these elements have high radiation absorptivity, so that a radiographic image with better granularity can be obtained.
  Further, the above formula (Gd, M, Eu) ₂ O _Three In the above, gadolinium Gd is preferably 40 to 95% by mass, europium Eu is preferably 2 to 20% by mass, gadolinium Gd is particularly preferably 70 to 90% by mass, and europium Eu is particularly preferably 5 to 10% by mass.
[0011]
The crystallite size, which is an index indicating the size of the crystallites constituting the phosphor particles, is 10 to 100 nm. When the crystallite size is smaller than 10 nm, the light emission efficiency is lowered. The average particle size of the phosphor particles is preferably 0.2 to 5 μm. When the average particle size is smaller than 0.2 μm, the light emission efficiency is lowered, and when it is larger than 5 μm, the scattering of light emission in the radiation image conversion panel is increased and the sharpness is deteriorated. Furthermore, the average particle size of the phosphor particles is preferably 0.5 to 2 μm.
The crystallite size is measured by selecting 10 to 15 measurable peaks of diffraction peaks obtained by X-ray diffraction using the method described in Kyoritsu Shuppan Co., Ltd., Instrumental Analysis Practical Series X-ray Analysis. It calculated using the Wilson method.
In addition, the particle size of the phosphor particles is determined by dispersing the phosphor particles in water using an appropriate surfactant and measuring the particle size using a light scattering particle measuring device (for example, Horiba LA910). Can be sought.
Here, the particle diameter of the phosphor particles is measured by dispersing the phosphor in water using an appropriate surfactant and using a light scattering particle measuring apparatus (for example, Horiba LA910).
[0012]
The shape of the phosphor particles is preferably spherical. This is because the spherical shape increases the dispersibility of the phosphor particles in the binder and increases the filling rate of the phosphor particles in the binder, thereby improving the granularity.
Next, the manufacturing method of the fluorescent substance used for the radiation image conversion panel of this invention is demonstrated.
The phosphor particles used in the radiation image conversion panel of the present invention are precipitated by adding urea to an aqueous solution containing a salt of a rare earth element to precipitate a basic carbonate, and subjecting the resulting precipitate to solid-liquid separation, It can be obtained by firing at 500 ° C. or higher.
[0013]
Next, the formula (Gd, M, Eu)₂O_ThreeThe case where yttrium Y is used as the rare earth element M in the phosphor represented by (M represents a rare earth element) will be specifically described.
An aqueous solution containing rare earth elements gadolinium Gd, yttrium Y, europium Eu is heated at 80 ° C. or higher for 0.5 to 5 hours, urea or urea and hydrogen peroxide are added and further heated, and the basic carbonic acid of the rare earth elements is added. When spherical particles of the salt are deposited and the precipitated basic carbonate of the rare earth element is solid-liquid separated, spherical particles of the rare earth element basic carbonate are obtained. The amount of urea added is preferably about 3 to 5 times that of the rare earth element, and the amount of hydrogen peroxide added is preferably 1/100 to 30/100 of the rare earth ion concentration.
Rare earth element oxide spherical particles can be obtained by further firing the obtained spherical particles of basic carbonate in air or in an oxidizing atmosphere. The firing temperature is preferably 500 ° C. or higher.
[0014]
In the above, spherical particles of rare earth element basic carbonate are precipitated, but the rare earth element salt to be precipitated is organic phosphate, malonate, glycolate, sebacate, cacodylate and many Benzenesulfonic acid derivative salts, aminopolyacetates (EDTA, DCTA, HEDTA, DE, ME, NTA, IMDA salts), acetylacetonate, alkoxide, cyclooctatetraene complex, cyclopentadiene It may be a complex.
Examples of the aqueous solution containing a rare earth element salt include aqueous solutions of hydrochloride, sulfate, nitrate, etc. Among them, an aqueous solution of nitrate is preferable.
The addition amount of hydrogen peroxide is preferably 1/100 to 30/100 with respect to the concentration of rare earth ions, and the addition amount of urea is preferably about 3 to 5 times the concentration of rare earth elements.
When the obtained basic carbonate of rare earth element is baked at 500 ° C. or higher, spherical rare earth element oxide particles maintaining the spherical shape of the basic carbonate can be obtained, and the oxide particles can be used as phosphors. Use.
[0015]
The phosphor particles thus obtained have a spherical particle shape and a narrow particle size distribution. Therefore, the dispersibility of the phosphor particles in the binder is high, the uniformity of the phosphor distribution in the direction of radiation irradiation can be improved, and the filling rate of the phosphor particles in the binder can be increased, so that the graininess can be improved. A good radiographic image can be obtained. Moreover, since radiation scattering in the radiation image conversion panel is reduced, a radiation image with less blur can be obtained.
The produced phosphor powder is dispersed in a binder and molded as a radiation image conversion panel. Examples of the binder include polyurethane, polyester, vinyl chloride copolymer (for example, vinyl chloride-acrylonitrile copolymer), butadiene-acrylonitrile copolymer, polyamide resin, polyvinyl butyral, cellulose derivative (for example, nitrocellulose), Examples thereof include styrene-butadiene copolymers, synthetic rubber polymers, phenol resins, epoxy resins, urea resins, melanin resins, phenoxy resins, silicon resins, acrylic resins, urea formamide resins, and the like. Of these, polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, and nitrocellulose are preferably used. These preferable binders can increase the dispersibility of the phosphor, increase the filling rate of the phosphor, and contribute to the improvement of graininess.
[0016]
The weight content of the phosphor dispersed in the binder is 90 to 99%. The thickness of the radiation image conversion panel layer is determined from the balance between the granularity and sharpness of the radiation image. When the radiation image conversion panel layer is thick, the graininess is improved but the sharpness is deteriorated. When the radiation image conversion panel layer is thin, the sharpness is improved, but the graininess is deteriorated. Generally, the graininess is reduced from 20 μm to 1 mm. . Furthermore, in order to obtain good graininess and sharpness, the thickness is preferably 50 μm to 300 μm.
When the radiation image conversion panel comprises a support and a phosphor layer provided on the surface thereof, various polymer materials, glass, metal, and the like can be used as the support.
From the viewpoint of handling, the radiation image conversion panel is preferably a flexible radiation image conversion panel sheet or web. In this respect, the support is a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyamide film, A plastic film such as a polyimide film, a triacetate film or a polycarbonate film, a metal sheet such as aluminum, iron, copper, or chromium, or a metal sheet having a coating layer of the metal oxide is preferable.
The layer thickness of the support varies depending on the material of the support used, but is generally 3 μm to 1000 μm, and more preferably 80 μm to 500 μm from the viewpoint of handling.
The surface of these supports may be a smooth surface or a matte surface in order to improve the adhesion to the phosphor layer.
Further, these supports may be provided with an undercoat layer in order to improve the adhesion to the phosphor layer.
[0017]
Since the phosphor used in the present invention has high hygroscopicity except for a part, it is preferable to seal and use it so as not to be affected by environmental moisture. For sealing, for example, methods disclosed in JP-A-11-223890, JP-A-11-249243, JP-A-11-344598, JP-A-2000-171597 can be used, The entire radiation image conversion panel can be sealed.
[0018]
  Next, used in the present inventionSilver salt photothermographic dry imaging materialsWill be described.
  It is exposed with the exposure method of the present invention.Silver salt photothermographic dry imaging material using organic silver salt particles, photosensitive silver halide particles and reducing agentIs not particularly limited,Silver salt photothermographic dry imaging material using organic silver salt particles, photosensitive silver halide particles and reducing agentIf anyIt may be a silver salt photothermographic dry imaging material.
  In the silver salt photothermographic dry imaging material of the present invention,The photosensitive silver halide functions as an optical sensor, and the organic silver salt is reduced with a reducing agent to form an image.
[0019]
Details of the silver salt photothermographic dry imaging material are described in, for example, US Pat. Nos. 3,152,904, 3,457,075 and D.C. “Dry Silver Photographic Material” by Morgan, D.M. Morgan and B.M. “Thermally Processed SilverSystems” by Shelly (Imaging Processes and Materials) Nebelte, 8th Edition, St. Wall, W. Wall. ), Edited by A. Shepp, page 2, 1969).
[0020]
Hereinafter, the silver salt photographic light-sensitive material will be sequentially described by taking a silver salt photothermographic dry imaging material as an example.
As the organic silver salt used in the silver salt photothermographic dry imaging material, for example, a silver salt of an organic acid and a heteroorganic acid is used. Among them, a long chain (having 10 to 30 carbon atoms, preferably 15 to 25 carbon atoms) is used. ) And a silver salt of a nitrogen-containing heterocyclic compound. Further, the organic compounds described in Research Disclosure (hereinafter sometimes abbreviated as RD) 17029 and 29963 in which the ligand has a value of 4.0 to 10.0 as the total stability constant with respect to silver ions, or Inorganic complexes are also preferred.
Examples of these suitable silver salts include the following.
Silver salts of organic acids such as gallic acid, succinic acid, behenic acid, stearic acid, arachidic acid, palmitic acid, lauric acid, etc .; silver carboxyalkylthiourea salts such as 1- (3-carboxypropyl) thio Silver salts such as urea and 1- (3-carboxypropyl) -3,3-dimethylthiourea; silver salts or complexes of polymer reaction products of aldehydes and hydroxy-substituted aromatic carboxylic acids, such as aldehydes (for example, formaldehyde) , Acetaldehyde, butyraldehyde, etc.) and hydroxy-substituted acids (for example, salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid), silver salts or complexes of reaction products; silver salts or complexes of thiones, such as 3- ( 2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thione, and 3-carboxy Silver salts or complexes such as til-4-thiazoline-2-thione; imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,4-triazole and A complex or salt of nitrogen acid and silver selected from benztriazole; silver salt such as saccharin and 5-chlorosalicylaldoxime; silver salt of mercaptides.
Among these, particularly preferred silver salts include silver salts of aliphatic carboxylic acids having a long chain (10 to 30 carbon atoms, preferably 15 to 25 carbon atoms) such as silver behenate, silver arachidate, and silver stearate. .
In the present invention, it is preferable that two or more organic silver salts are mixed in order to improve developability and form a silver image having a high density and a high contrast. For example, silver ions are mixed into two or more organic acid mixtures. It is preferable to prepare by mixing the solutions.
[0021]
The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound that forms a complex with silver, and is described in a normal mixing method, a reverse mixing method, a simultaneous mixing method, and Japanese Patent Application Laid-Open No. 9-127643. Such a controlled double jet method is preferably used. For example, an alkali metal salt such as sodium hydroxide or potassium hydroxide is added to an organic acid to produce an organic acid alkali metal salt soap such as sodium behenate or sodium arachidate, and then a controlled double Organic silver salt crystals can be prepared by mixing the soap and silver nitrate by the jet method. In production, photosensitive silver halide grains may be mixed.
[0022]
The shape of the organic silver salt particles may be any shape, but tabular particles are preferred. In particular, it is a flat organic silver salt particle having an aspect ratio of 3 or more, and the shape anisotropy of two substantially parallel faces (main planes) having the largest area is small, so that filling in the photosensitive layer is possible. For this purpose, particles having an average needle-like ratio of the tabular organic silver salt particles measured from the main plane direction of 1.1 or more and less than 10.0 are preferable. A more preferable acicular ratio is 1.1 or more and less than 5.0.
In the present invention, the tabular organic silver salt particles having an aspect ratio of 3 or more are organic silver salt particles in which the number of tabular organic silver salt particles having an aspect ratio of 3 or more occupies 50% or more of the total organic silver salt particles. Say. Furthermore, organic silver salt particles in which tabular organic silver salt particles having an aspect ratio of 3 or more account for 60% or more, more preferably 70% or more, particularly 80% or more of the total organic silver salt particles are preferable.
[0023]
In the present invention, tabular grains having an aspect ratio of 3 or more refer to grains having a ratio of particle diameter to thickness, a so-called aspect ratio (hereinafter abbreviated as AR) represented by the following formula of 3 or more.
AR = particle diameter (μm) / thickness (μm)
The aspect ratio of the organic silver salt particles used in the photothermographic image forming material used in the present invention is preferably 3 to 20, and more preferably 3 to 10.
If the aspect ratio is too low, the organic silver salt particles tend to be packed most closely, and if the aspect ratio is too high, the organic silver salt particles tend to overlap with each other and are dispersed in a stuck state. Therefore, light scattering or the like is likely to occur, and as a result, the transparency of the photosensitive material is lowered.
[0024]
Although there is no specific method for obtaining the organic silver salt particles having the above-mentioned shape, silver nitrate is added to the mixed state and / or the organic acid alkali metal salt soap during the formation of the organic acid alkali metal salt soap. Effective means include maintaining a good mixed state during addition and optimizing the ratio of silver nitrate that reacts with the organic acid alkali metal salt soap.
The organic silver salt particles are preferably pre-dispersed with a binder, a surfactant or the like, if necessary, and dispersed and pulverized with a media disperser or a high-pressure homogenizer. For preliminary dispersion, a general stirrer such as an anchor type or a propeller type, a high-speed rotating centrifugal radiation type stirrer (dissolver), or a high-speed rotating shear type stirrer (homomixer) can be used.
[0025]
Further, as the media disperser used for the above-mentioned dispersion pulverization, a rolling mill such as a ball mill, a planetary ball mill, a vibration ball mill, a bead mill that is a medium agitation mill, an attritor, and other basket mills can be used. As the homogenizer, a type that collides with a wall, a plug, or the like, a type that collides liquids at a high speed after dividing the liquid into a plurality of types, a type that passes through a thin orifice, or the like can be used.
[0026]
In the present invention, a preferable silver salt photothermographic dry imaging material is 0.025 μm when a cross section perpendicular to the support surface of the material is observed with an electron microscope.²The proportion of organic silver salt particles exhibiting a projected area of less than 70% of the total projected area of organic silver salt particles, and 0.2 μm²Silver salt photothermographic dry imaging obtained by coating a photosensitive emulsion containing an organic silver salt and a photosensitive silver halide in which the ratio of grains exhibiting the above projected area is 10% or less of the total projected area of the organic silver salt grains Material. In this silver salt photothermographic dry imaging material, it is possible to obtain a uniformly distributed state with little aggregation of organic silver salt particles in the photosensitive emulsion.
The conditions for producing the photosensitive emulsion having such characteristics are not particularly limited, but the mixed state at the time of forming the organic acid alkali metal salt soap and / or the mixed state at the time of adding silver nitrate to the soap are favorable. Maintaining, optimizing the proportion of silver nitrate that reacts with soap, dispersing and grinding with a media disperser or a high-pressure homogenizer, the binder concentration is 0.1 to 10% of the mass of organic silver In addition to the fact that the temperature from drying to the end of the main dispersion does not exceed 45 ° C., it is preferable to use a dissolver at the time of liquid preparation and stir at a peripheral speed of 2.0 m / second or more.
[0027]
In the present invention, in order to prevent devitrification of the light-sensitive material, the total amount of silver halide and organic silver salt is 1 m in terms of silver amount.²It is preferably 0.5 g or more and 2.2 g or less per unit. By setting this range, an image preferable as a medical image can be obtained.
[0028]
Next, the photosensitive silver halide grains used in the silver salt photothermographic dry imaging material will be described. The photosensitive silver halide grains in the present invention are inherently light-absorbing or intrinsically absorbing visible light or infrared light by a physicochemical method as a characteristic of silver halide crystals. In addition, physicochemical changes can occur in the silver halide crystal and / or on the crystal surface when light in any region within the light wavelength range from the ultraviolet light region to the infrared light region is absorbed. A silver halide crystal grain produced by processing.
The silver halide grains themselves used in the present invention are P.I. Chifie et Physique Photographic (published by PaulMontel, 1967) by Glafkides. F. Duffin's Photographic Emission Chemistry (published by The Focal Press, 1966), V.C. L. It can be prepared as a silver halide grain emulsion using the method described in Making and Coating Photographic Emulsion (published by The Focal Press, 1964) by Zelikman et al. That is, for the preparation, any method such as an acidic method, a neutral method, an ammonia method, etc. may be used. As a form for reacting a soluble silver salt and a soluble halogen salt, a one-side mixing method, a simultaneous mixing method, Any combination thereof may be used.
[0029]
As a method for adjusting the silver halide grains, the so-called controlled double jet method in which the silver halide grains are prepared while controlling the formation conditions among the above methods is preferable because the grain shape and size can be controlled. The halogen composition of the silver halide grains is not particularly limited and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide.
The formation of silver halide grains is usually carried out in two stages: silver halide seed grain (nucleus) generation and grain growth, but these may be performed continuously at once, and Particle) formation and particle growth may be performed separately. At this time, a controlled double jet method in which pAg, pH and the like are controlled to form particles can be used.
The method of separating the formation of nuclei (seed grains) and the growth of grains follows the nucleation step in which soluble silver salts and soluble halogen salts are rapidly and uniformly mixed in an aqueous gelatin solution to form nuclei (seed grains). Thus, it can be carried out by preparing silver halide grains by carrying out a grain growth step of growing grains while supplying a soluble silver salt and a soluble halogen salt under controlled pAg, pH and the like. After the formation of grains, the desired salt halide emulsion can be obtained by removing unnecessary salts by a desalting step by a known desalting method such as a noodle method, a flocculation method, an ultrafiltration method or an electrodialysis method. Obtainable. It can also be used without desalting.
[0030]
The average grain size of the silver halide grains is preferably small in order to keep the cloudiness after image formation low and to obtain good image quality, and the average grain size is 0.2 μm or less, more preferably 0.01 μm to 0.17 μm. In particular, 0.02 μm to 0.14 μm is preferable. Here, the grain size means 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. Further, when the silver halide grains are tabular grains, it means the diameter of a circle having the same area as the projected area of the main surface.
The grain size distribution of the silver halide grains is preferably monodispersed. Monodispersion here means that the variation coefficient of the particle size distribution obtained by the following formula is 30% or less. The variation count is preferably 20% or less, more preferably 15% or less.
Variation coefficient of particle size distribution% = standard deviation of particle size / average value of particle size × 100
Examples of the silver halide grains include cubes, octahedrons, tetradecahedral grains, tabular grains, spherical grains, rod-like grains, and potato-like grains. Among these, cubic, octahedral, tetradecahedral, tabular halides are available. Silver particles are preferred.
[0031]
The tabular silver halide grains preferably have an average aspect ratio of 1.5 or more and 100 or less, more preferably 2 or more and 50 or less. The method for preparing these tabular silver halide grains is described in US Pat. Nos. 5,264,337, 5,314,798, 5,320,958 and the like. The desired tabular grains can be easily obtained. Further, as the silver halide grains, grains having rounded corners of silver halide grains can be preferably used.
The crystal habit of the outer surface of the silver halide grain used is not particularly limited, but as a spectral sensitizing dye, spectral sensitization having crystal habit (plane) selectivity for adsorption of the silver sensitizing dye onto the surface of the silver halide grain. When using a dye, it is preferable to use silver halide grains having a relatively high proportion of crystal habits adapted to the selectivity. For example, when using a sensitizing dye that is selectively adsorbed on the crystal plane of the Miller index (100), the proportion of the (100) plane on the outer surface of the silver halide grains is preferably high, and this proportion is 50 % Or more, more preferably 70% or more, and particularly preferably 80% or more. Note that the ratio of the Miller index (100) plane is a T.V. based on the adsorption dependency between the (111) plane and the (100) plane in the adsorption of the sensitizing dye. Tani, J .; Imaging
Sci. 29, 165 (1985).
[0032]
The silver halide grains may be added to the image forming layer by any method. At this time, the silver halide grains are preferably arranged so as to be close to a reducible silver source (organic silver salt).
[0033]
In order to place silver halide grains close to a reducible silver source (organic silver salt), silver halide is prepared in advance and added to a solution for preparing organic silver salt grains. Can be done. This method is preferable for controlling the production conditions because the silver halide preparation step and the organic silver salt grain preparation step can be handled separately.
Further, in order to arrange the silver halide grains close to a reducible silver source (organic silver salt), as described in British Patent 1,447,454, organic silver salt grains When preparing silver halide grains such as halide ions coexist with organic silver salt forming components, and by injecting silver ions into this, silver halide grains are produced almost simultaneously with the formation of organic silver salt grains. Can do.
[0034]
Furthermore, it can also be carried out by allowing a halogen-containing compound to act on an organic silver salt and preparing silver halide grains by conversion of the organic silver salt. For example, a part of the organic silver salt is converted into photosensitive silver halide by causing a silver halide forming component to act on a solution or dispersion of the organic silver salt prepared in advance or on a sheet material containing the organic silver salt. Can also be done.
In this case, as the silver halide forming component, inorganic halogen compounds, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds are used. Specific examples thereof include US Pat. No. 009,039, No. 3,457,075, No. 4,003,749, British Patent No. 1,498,956, JP-A-53-27027, Inorganic halides such as metal halides and ammonium halides detailed in JP-A-53-25420, for example, onium halides such as trimethylphenylammonium bromide, cetylethyldimethylammonium bromide, trimethylbenzylammonium bromide, such as iodine Form, bromoform, carbon tetrachloride, 2-bu Halogenated hydrocarbons such as mu-2-methylpropane, N-halogen compounds such as N-bromosuccinimide, N-bromophthalimide, N-bromoacetamide, and others, for example, triphenylmethyl chloride, triphenyl bromide Examples include methyl, 2-bromoacetic acid, 2-bromoethanol, dichlorobenzophenone, and the like.
Thus, the silver halide can also be prepared by reacting an organic acid silver and a halogen ion to convert silver in the organic acid silver salt into silver halide. In addition, as the silver halide, separately prepared silver halide grains and silver halide grains obtained by converting a part of the organic silver salt may be used in combination.
Regardless of the silver halide grains obtained, the silver halide grains are used in an amount of 0.001 to 0.7 mol, preferably 0.03 to 0.5 mol, per mol of the organic silver salt. preferable.
[0035]
[Chemical sensitizer]
The silver halide grains used in the silver salt photothermographic dry imaging material of the present invention can be chemically sensitized. For example, a compound that releases a chalcogen such as sulfur or a noble metal ion that releases a noble metal ion such as a gold ion by the method disclosed in Japanese Patent Application No. 12-057004 and Japanese Patent Application No. 12-061942 Can be used to form and impart a chemical sensitization center (chemical sensitization nucleus).
In the present invention, it is preferably chemically sensitized with an organic sensitizer containing a chalcogen atom such as sulfur, selenium or tellurium.
The organic sensitizer containing chalcogen atoms is preferably a compound having a group capable of adsorbing to silver halide and an unstable chalcogen atom site.
As these organic sensitizers, organic sensitizers having various structures disclosed in JP-A-60-150046, JP-A-4-109240, JP-A-11-218874 and the like are used. Of these, at least one compound having a structure in which a chalcogen atom is bonded to a carbon atom or a phosphorus atom by a double bond is preferable.
The amount of the chalcogen compound used varies depending on the chalcogen compound to be used, silver halide grains, the reaction environment for chemical sensitization, etc., but in general, it is 10 per mol of silver halide.^-8-10^-2Moles are used, preferably 10^-7-10^-3Is a mole.
[0036]
There are no particular restrictions on the environment for chemical sensitization, but it is preferably performed under conditions where there is no organic acid silver salt such as silver behenate, and silver chalcogenide or silver produced on silver halide grains. Chalcogen sensitization using organic sensitizers containing chalcogen atoms in the presence of oxidants that can oxidize silver nuclei, especially in the presence of compounds that can annihilate nuclei or reduce their size In this case, the sensitizing condition is preferably that pAg is 6 to 11, more preferably 7 to 10, and pH is preferably 4 to 10, more preferably 5 to 8. In addition, sensitization is preferable at a temperature of 30 ° C. or lower.
Therefore, in the silver salt photothermographic dry imaging material of the present invention, the photosensitive silver halide uses an organic sensitizer containing a chalcogen atom in the presence of an oxidizing agent capable of oxidizing a silver nucleus on the grain. It is preferable to use a photosensitive emulsion that has been chemically sensitized at a temperature of 30 ° C. or lower, mixed with an organic silver salt, dispersed, dehydrated and dried.
[0037]
Further, chemical sensitization using an organic sensitizer is also preferably performed in the presence of a heteroatom-containing compound having adsorptivity to spectral sensitizing dyes or silver halide grains. By performing chemical sensitization in the presence of a compound having an adsorptivity to silver halide, dispersion of the chemical sensitization central core can be prevented, and high sensitivity and low fog can be achieved. The spectral sensitizing dye to be used will be described later. Preferred examples of the heteroatom-containing compound having adsorptivity to silver halide include nitrogen-containing heterocyclic compounds described in JP-A-3-24537. .
Examples of the heterocyclic ring that these nitrogen-containing heterocyclic compounds have include, for example, a pyrazole ring, a pyrimidine ring, a 1,2,4-triazole ring, a 1,2,3-triazole ring, a 1,3,4-thiadiazole ring, 2,3-thiadiazole ring, 1,2,4-thiadiazole ring, 1,2,5-thiadiazole ring, 1,2,3,4-tetrazole ring, pyridazine ring, 1,2,3-triazine ring, these A ring in which 2 to 3 rings are bonded, for example, a triazolotriazole ring, a diazaindene ring, a triazaindene ring, a pentaazaindene ring, and the like can be given. Moreover, the heterocyclic ring which condensed the monocyclic heterocyclic ring and the aromatic ring, for example, a phthalazine ring, a benzimidazole ring, an indazole ring, a benzthiazole ring etc. can be mentioned.
Among these, an azaindene ring is preferable, and an azaindene compound having a hydroxy group as a substituent, for example, hydroxytriazaindene, tetrahydroxyazaindene, hydroxypentaazaindene and the like are more preferable.
The heterocyclic ring may have a substituent other than a hydroxy group, for example, an alkyl group, a substituted alkyl group, an alkylthio group, an amino group, a hydroxyamino group, an alkylamino group, a dialkylamino group, an arylamino group, a carboxyl group , An alkoxycarbonyl group, a halogen atom, a cyano group, and the like.
The addition amount of these heterocyclic compounds varies over a wide range depending on the size, composition and other conditions of the silver halide grains, but the approximate addition amount is 10 per mol of silver halide.^-6Mol to 1 mol, preferably 10^-FourMol-10^-1The range of moles.
[0038]
As described above, the silver halide grains can be subjected to noble metal sensitization using a compound that releases noble metal ions such as gold ions. For example, a chloroaurate or an organic gold compound can be used as a gold sensitizer.
In addition to the above-described sensitization methods, reduction sensitization methods and the like can also be used. Examples of shell-like compounds used for reduction sensitization include ascorbic acid, thiourea dioxide, stannous chloride, hydrazine derivatives, Examples thereof include a borane compound, a silane compound, and a polyamine compound. 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.
The silver halide subjected to chemical sensitization may be formed in the presence of an organic silver salt, formed in the absence of an organic silver salt, or a mixture of both. .
[0039]
[Dopant doped into silver halide]
The silver halide used in the present invention preferably contains transition metal ions belonging to Groups 6 to 11 of the Periodic Table of Elements. As the metal, W, Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, Pt, and Au are preferable. These metal ions may be used alone or in combination of two or more of the same or different metal ions. These metal ions can be introduced into silver halides as metal salts or metal complexes. Metal ions are 1 x 10 per mole of silver^-9Mol ~ 1 × 10^-2It is preferably contained in a molar range of 1 × 10^-8~ 1x10^-FourThe range of is more preferable.
It is preferable to use a transition metal complex or complex ion represented by the following general formula.
[0040]
General formula [ML₆]^m
In the formula, M represents a transition metal selected from Group 6 to 11 elements of the periodic table, and L represents a ligand. m represents 0,-, 2-, 3- or 4-.
Specific examples of the ligand represented by L include halogen ions (for example, fluorine ion, chlorine ion, bromine ion, iodine ion), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and aquo. Although each ligand, nitrosyl, thionitrosyl, etc. are mentioned, Ako, nitrosyl, thionitrosyl, etc. are preferable. When an acoligand is present, it preferably occupies one or two of the ligands. Each L may be the same or different.
[0041]
These metal ion or complex ion-providing compounds are preferably added at the time of silver halide grain formation and incorporated into the silver halide grains. Nucleation, growth, physics, which are stages of silver halide grain preparation, are preferred. It may be added at any stage before and after ripening and chemical sensitization, but it is particularly preferred to add at the stage of nucleation, growth and physical ripening, and more preferably at the stage of nucleation and growth. Most preferably, it is added at the stage of nucleation.
These metals can also be uniformly contained in the silver halide grains, or disclosed in JP-A-63-29603, JP-A-2-306236, JP-A-3-167545, and JP-A-4-76534. As described in JP-A-6-110146, JP-A-5-273683, and the like, the particles can be included with a distribution.
[0042]
These metal compounds can be added by dissolving in water or an appropriate organic solvent (for example, alcohols, ethers, glycols, ketones, esters, amides). For example, a method of adding an aqueous solution of a metal compound or an aqueous solution in which a metal compound and NaCl, KCl are dissolved together to a water-soluble silver salt solution or a water-soluble halide solution during particle formation, a silver salt solution and a halide solution. It can be added by a method of simultaneous mixing of three solutions added as a third aqueous solution when mixing at the same time, or a method of adding a required amount of an aqueous solution of a metal compound into a reaction vessel during the formation of silver halide grains. Alternatively, silver halide grains doped with metal ions or complex ions in advance may be prepared, and the doped silver halide grains may be added at the time of silver halide preparation. 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.
When these metal compounds are added to the particle surface, a required amount of an aqueous solution of the metal compound is charged into the reaction vessel immediately after the formation of the particles, during or after physical ripening, or at the time of chemical ripening.
[0043]
[Spectral sensitization]
The photosensitive silver halide grains can be spectrally sensitized by adsorbing a spectral sensitizing dye.
Examples of spectral sensitizing dyes that can be used include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, styryl dyes, hemicyanine dyes, oxonol dyes, hemioxonol dyes, and the like. For example, JP-A-63-159841, JP-A-60-140335, 63-231437, 63-259651, 63-304242, 63-15245, U.S. Pat. 6,39,414, 4,740,455, 4,741,966, 4,751,175, 4,835,096 Sensitizing dyes described in the book can be used.
Furthermore, useful sensitizing dyes are described in, for example, documents described or cited in Section RD17643 IV-A (December 1978, p.23) and Section 18431X (August 1978, p.437). .
Useful cyanine dyes are, for example, cyanine dyes having basic nuclei such as thiazoline nucleus, oxazoline nucleus, pyrroline nucleus, pyridine nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus and imidazole nucleus. Useful merocyanine dyes are preferably acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus in addition to the basic nuclei described above. Including.
[0044]
[Supersensitizer]
In addition, the emulsion containing silver halide grains and organic silver salt grains used in the photothermographic dry imaging material of the present invention substantially contains a dye having no spectral sensitizing action or visible light itself together with a sensitizing dye. A substance that does not absorb and exhibits a supersensitization effect may be included in the emulsion for supersensitization.
Useful sensitizing dyes, dyes or substances exhibiting supersensitization are RD17643 (issued in December, 1978), page 23, 1V, or Japanese Patent Publication Nos. 9-25500 and 43-4933, Although described in JP-A-59-19032, JP-A-59-192242, JP-A-5-341432, etc., the supersensitizer is represented by the following general formula [6]. Heteroaromatic mercapto compounds or mercapto derivative compounds are preferred.
[0045]
General formula [6] Ar-SM
(In the formula, M represents a hydrogen atom or an alkali metal atom, and Ar represents a group having an aromatic ring or condensed aromatic ring having one or more nitrogen, sulfur, oxygen, selenium, or tellurium atoms.)
Examples of the aromatic ring or condensed aromatic ring in the group having an aromatic ring or condensed aromatic ring having one or more nitrogen, sulfur, oxygen, selenium, or tellurium atoms represented by Ar include a benzimidazole ring and a naphthimidazole ring. , Benzthiazole ring, naphthothiazole ring, benzoxazole ring, naphthoxazole ring, benzselenazole ring, benztelrazole ring, imidazole ring, oxazole ring, pyrazole ring, triazole ring, triazine ring, pyrimidine ring, pyridazine ring, pyrazine ring , A pyridine ring, a purine ring, a quinoline ring, and a quinazoline ring are preferable, but other heteroaromatic rings may be used.
Further, a mercapto derivative compound which substantially produces the above mercapto compound when contained in a dispersion of an organic acid silver salt and / or a silver halide grain emulsion can also be used.
A preferred example is a mercapto derivative compound represented by the following general formula [7].
[0046]
General formula [7] Ar-SS-Ar
(In the formula, Ar has the same meaning as Ar in the heteroaromatic mercapto compound represented by the above general formula [6].)
An aromatic ring or a condensed group in an aromatic ring having one or more nitrogen, sulfur, oxygen, selenium, or tellurium atoms or a group having a condensed aromatic ring represented by Ar in the above general formula [6] and general formula [7] The aromatic ring may have a substituent, and examples of the substituent include a halogen atom (for example, Cl, Br, I), a hydroxy group, an amino group, a carboxyl group, and an alkyl group (preferably, Alkyl groups having 1 to 4 carbon atoms) and alkoxy groups (for example, those having 1 or more carbon atoms, preferably 1 to 4 carbon atoms).
The supersensitizer is preferably used in the range of 0.001 to 1.0 mole per mole of silver in the emulsion layer containing an organic silver salt and silver halide grains. Particularly preferred is an amount in the range of 0.01 to 0.5 mole per mole of silver.
[0047]
[Non-polyhalogen compound-based printout inhibitor]
Silver salt photothermographic dry imaging materials contain a large amount of photosensitive silver halide, organic silver and developer that can cause fogging and printout silver (baked-out silver) before and after processing. Has been. Therefore, it is necessary for silver salt photothermographic dry imaging materials to use advanced fog prevention and image stabilization techniques for maintaining storage stability not only before development but also after development. Conventionally, aromatic heterocyclic compounds that suppress growth and development of fog nuclei and fog nuclei are oxidized and extinguished in order to maintain storage stability and prevent occurrence of fog and printout silver (baked-out silver). A mercury compound such as mercury acetate having a function has been used, but the mercury compound has a problem in its use from the viewpoint of safety / environmental conservation.
The antifogging and image stabilizer suitable for the silver salt photothermographic dry imaging material used in the present invention will be described below.
As described later, a reducing agent is used in the silver salt photothermographic dry imaging material. As these reducing agents, as will be described later, mainly reducing agents having protons such as bisphenols and sulfonamidophenols are used, so that active species capable of extracting these hydrogens are generated. It is preferable that the compound which can inactivate a reducing agent by this is contained. These compounds are preferably colorless photo-oxidizable compounds that can generate free radicals as reactive species during exposure.
[0048]
These compounds may be any compounds as long as they have these functions, but organic free radicals composed of a plurality of atoms are preferable, as long as they do not cause any particular adverse effects on silver salt photothermographic dry imaging materials. A compound having any structure may be used.
In addition, a compound that generates free radicals is carbocyclic or heterocyclic in order to have a stability that allows the generated free radicals to be in contact for a time sufficient to react with the reducing agent and be inactivated. Those having an aromatic group are preferred.
Typical examples of these compounds include the following biimidazolyl compounds and iodonium compounds.
As the biimidazolyl compound, a biimidazolyl compound represented by the following general formula [1] is preferably used.
[0049]
[Chemical 1]

In the general formula [1], R₁, R₂And R_ThreeIs an alkyl group (for example, methyl group, ethyl group, hexyl group, etc.), alkenyl group (for example, vinyl group, allyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, octyloxy group, etc.), aryl group ( For example, phenyl group, naphthyl group, tolyl group etc.), hydroxy group, halogen atom, aryloxy group (eg phenoxy group etc.), alkylthio group (eg methylthio group, butylthio group etc.), arylthio group (eg phenylthio group) Etc.), acyl groups (eg acetyl group, propionyl group, butyryl group, valeryl group etc.), sulfonyl groups (eg methylsulfonyl group, phenylsulfonyl group etc.), acylamino groups, sulfonylamino groups, acyloxy groups (eg acetoxy) Group, benzoxy group, etc.), carboxyl group, cyano Represents a substituent such as a sulfo group and an amino group. Among these, preferred substituents are an aryl group, an alkenyl group, and a cyano group.
The above-mentioned biimidazolyl compound can be produced by the production method described in US Pat. No. 3,734,733 and British Patent No. 1,271,177 and a method analogous thereto.
As the iodonium compound, an iodonium compound represented by the following general formula [2] is preferably used.
[0050]
[Chemical formula 2]

[0051]
In the general formula [2], R¹, R²And R^ThreeIs an alkyl group (for example, methyl group, ethyl group, hexyl group, etc.), alkenyl group (for example, vinyl group, allyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, octyloxy group, etc.), aryl group ( For example, phenyl group, naphthyl group, tolyl group etc.), hydroxy group, halogen atom, aryloxy group (eg phenoxy group etc.), alkylthio group (eg methylthio group, butylthio group etc.), arylthio group (eg phenylthio group) Etc.), acyl groups (eg acetyl group, propionyl group, butyryl group, valeryl group etc.), sulfonyl groups (eg methylsulfonyl group, phenylsulfonyl group etc.), acylamino groups, sulfonylamino groups, acyloxy groups (eg acetoxy) Group, benzoxy group, etc.), carboxyl group, cyano Represents a substituent such as a sulfo group and an amino group. Among these, preferred substituents are an aryl group, an alkenyl group, and a cyano group.
R^FourAre carboxylate groups such as acetate, benzoate, trifluoroacetate and O^-Represents. W represents 0 or 1.
X^-Represents an anionic counterion, and preferred examples include CH_ThreeCO₂ ^-, CH_ThreeSO_Three ^-And PF₆ ^-Is mentioned.
R^ThreeWhen is a sulfo group or a carboxyl group, W is 0 and R^FourIs O^-It is.
R¹, R²And R^ThreeAny of these may be bonded to each other to form a ring.
Among the iodonium compounds represented by the general formula [2], a particularly preferable compound is an iodonium compound represented by the following general formula [3].
[0052]
[Chemical Formula 3]

Where R¹, R², R^Three, R^Four, X^-And W and the like represent the same as in the general formula [2], and Y represents a carbon atom (—CH═; benzene ring) or a nitrogen atom (—N =; pyridine ring).
[0053]
The above iodonium compounds are described in Org. Syn. , 1961 and Advanced Organic Chemistry (by Fieser) (Reinhold, NY, 1961) and a method analogous thereto.
The preferable addition amount of the biimidazolyl compound represented by the general formula [1] and the iodonium compound represented by the general formula [2] is 0.001 to 0.1 mol / m.²More preferably, it is 0.005 to 0.05 mol / m.²Range. The compound can be contained in any constituent layer of the silver salt photothermographic dry imaging material, but is preferably present in the vicinity of the reducing agent.
[0054]
[Polyhalogen compound-based printout inhibitor]
In the silver salt photothermographic dry imaging material used in the present invention, it is preferable to use a compound that inactivates the reducing agent so that the reducing agent cannot reduce the organic silver salt to silver. These compounds are preferably those in which the reactive species are not halogen atoms, but compounds that release halogen atoms as active species can also be used in combination with compounds that release active species that are not halogen atoms. Many compounds that can release a halogen atom as an active species are known, and a good effect can be obtained by using these compounds in combination.
Examples of the compound that releases an active species that is not a halogen atom include compounds represented by the following general formula [4].
[0055]
[Formula 4]

In the general formula [4], Q represents an aryl group or a heterocyclic group. X₁, X₂And X_ThreeRepresents a hydrogen atom, a halogen atom, a haloalkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an aryl group, or a heterocyclic group,₁, X₂And X_ThreeAt least one of is a halogen atom. Y is -C (= O)-, -SO- or -SO.₂-Represents.
The aryl group represented by Q may be monocyclic or may form a condensed ring with another ring, and is preferably a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms (for example, , Phenyl group, naphthyl group, etc.), more preferably phenyl group, naphthyl group, and still more preferably phenyl group.
The heterocyclic group represented by Q is preferably a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one atom of N, O or S, which may be monocyclic, A ring formed with another ring may be used.
The heterocyclic group is preferably a 5- to 6-membered unsaturated heterocyclic group which may have a condensed ring, more preferably a 5- to 6-membered aromatic heterocyclic group which may have a condensed ring. It is. More preferably, it is a 5- to 6-membered aromatic heterocyclic group optionally having a condensed ring containing a nitrogen atom, and particularly preferably a condensed ring containing 1 to 4 nitrogen atoms. A good 5- to 6-membered aromatic heterocyclic group.
[0056]
Examples of the heterocyclic group include imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, Acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, indolenine, tetrazaindene, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, oxa Diazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, teto A heterocyclic group derived from azole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, tetrazaindene is preferable, and more preferably, imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, quinoline, phthalazine , Naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, benzimidazole and benzthiazole, particularly preferably a heterocyclic group derived from pyridine, thiadiazole, quinoline and benzthiazole.
[0057]
The aryl group and heterocyclic group represented by Q are each represented by —Y—C (X₁) (X₂) (X_Three) May have a substituent, and preferable substituents include an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an acyloxy group, an acyl group, an alkoxycarbonyl group, and an aryloxycarbonyl group. , Acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, sulfonyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, sulfo group, carboxyl group , A nitro group, a heterocyclic group, etc., more preferably, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, The Famoyl group, carbamoyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, nitro group, heterocyclic group, more preferably alkyl group, aryl group, alkoxy group, aryloxy group, acyl group, acylamino A group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, a halogen atom, a cyano group, a nitro group and a heterocyclic group, particularly preferably an alkyl group, an aryl group and a halogen atom.
[0058]
X₁, X₂And X_ThreeIs a hydrogen atom, halogen atom, haloalkyl group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, sulfamoyl group, sulfonyl group, aryl group, heterocyclic group, preferably a halogen atom, haloalkyl group, acyl group , An alkoxycarbonyl group, an aryloxycarbonyl group, and a sulfonyl group, more preferably a halogen atom and a trihalomethyl group, and particularly preferably a halogen atom. Of the halogen atoms, preferred are a chlorine atom, a bromine atom and an iodine atom, more preferred are a chlorine atom and a bromine atom, and particularly preferred is a bromine atom. X₁, X₂And X_ThreeAt least one of is a halogen atom.
[0059]
Y is -C (= O)-, -SO-, -SO.₂-, Preferably -SO₂-.
The amount of the compound that generates these active halogen atoms in the silver salt photothermographic dry imaging material is preferably within a range in which the increase in the printout silver due to the formation of silver halide does not become a problem. It is 150% or less, more preferably 100% or less, in terms of the ratio to the compound that does not. In addition, the silver salt photothermographic dry imaging material used in the present invention may contain a compound conventionally known as an antifoggant in addition to the above compound, and the same reactive species as the above compound. Even if it is a compound which can be produced | generated, the compound from which an antifogging mechanism differs may be sufficient. As these compounds, for example, U.S. Pat. Nos. 3,589,903, 4,546,075, 4,452,885, JP-A-59-57234, Examples thereof include compounds described in U.S. Pat. Nos. 3,874,946, 4,756,999, JP-A-9-288328, and JP-A-9-90550. Further, as other antifoggants, US Pat. No. 5,028,523, European Patents 600,587, 605,981, and 631,176 Also disclosed are the disclosed compounds.
[0060]
Next, the reducing agent used in the silver salt photothermographic dry imaging material of the present invention will be described.
Examples of suitable reducing agents for these reducing agents are disclosed in US Pat. Nos. 3,770,448, 3,773,512, 3,593,863, RD17029 and 29963. It can be used by appropriately selecting from known reducing agents, but when using an aliphatic carboxylic acid silver salt as the organic silver salt, two or more phenol groups are alkylene groups or Sulfur-linked polyphenols, particularly alkyl groups (eg, methyl, ethyl, propyl, t-butyl, cyclohexyl, etc.) or acyl at least one position adjacent to the hydroxy substitution position of the phenol group Bisphenone in which two or more phenol groups substituted by a group (for example, acetyl group, propionyl group, etc.) are connected by an alkylene group or sulfur Louis preferable. More preferable examples of these preferable bisphenols include, for example, compounds represented by the following general formula (A).
[0061]
[Chemical formula 5]

In the general formula (A), R represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (for example, isopropyl group, butyl group, 2,4,4-trimethylpentyl group), and R ′ and R ″ are carbon atoms. An alkyl group having 1 to 8 atoms (for example, a methyl group, an ethyl group, or a t-butyl group) is represented.
[0062]
In addition, U.S. Pat. Nos. 3,589,903, 4,021,249, British Patent 1,486,148, JP-A-51-51933, 50-36110. No. 50-16023, No. 52-84727, JP-B 51-35727, polyphenol compounds described in US Pat. No. 3,672,904, bisnaphthols, For example, 2,2'-dihydroxy-1,1'-binaphthyl, 6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl and the like, and further, U.S. Pat. No. 3,801,321 Sulfonamidophenols or sulfonamidonaphthols as described in the literature, for example 4-benzenesulfonamidophenol, 2-benzenesulfone De, 2,6-dichloro-4-benzenesulfonamidophenol, and can also include 4-benzenesulphonamide naphthol.
In addition to the compounds listed above, the compounds described in Japanese Patent Application No. 2001-216659 are also included.
The amount of the reducing agent used in the photothermographic dry imaging material of the present invention varies depending on the type of organic silver salt, reducing agent, and other additives, but is generally 0.01 per mole of organic silver salt. It is used in the range of mol to 10 mol, more preferably in the range of 0.1 mol to 3 mol.
Moreover, the reducing agent mentioned above may be used independently, or may use 2 or more types together.
When a reducing agent is added to and mixed with a photosensitive emulsion solution composed of photosensitive silver halide and organic silver salt grains and a solvent, the addition of the reducing agent immediately before coating shortens the stagnation time in the coating solution and reduces photographic performance fluctuations. May be preferable.
In addition, the reducing agent should be used in combination with a compound capable of forming a hydrogen bond with hydrogen of the hydroxyl group of the reducing agent, such as triphenylphosphine oxide described in European Patent No. 1096310. Is also preferable.
[0063]
[Silver saving agent]
A silver saving agent can be used for the silver salt photothermographic dry imaging material used in the present invention.
The silver saving agent refers to a compound that can reduce the amount of silver necessary to obtain a certain silver image density. Various mechanisms of the function of reducing the function are considered, but a compound having a function of improving the covering power of developed silver is preferable. Here, the covering power of developed silver refers to the optical density per unit amount of silver.
Preferred examples of the silver saving agent include compounds described in Japanese Patent Application No. 2000-191062 and Japanese Patent Application No. 2001-192698.
[0064]
[binder]
Binders suitable for use in photothermographic dry imaging materials are transparent or translucent, generally colorless, and are natural polymer synthetic resins, polymers and copolymers, and other film-forming media 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 (urethanes), phenoxy resins, poly (vinylidene chloride), poly (epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and polyamides. The binder used may be hydrophilic or non-hydrophilic.
Preferred binders for use in the photosensitive layer of the photothermographic dry imaging material are polyvinyl acetals, and a particularly preferred binder is polyvinyl butyral. For non-photosensitive layers such as overcoat layers and undercoat layers, especially protective layers and backcoat layers, cellulose esters that are polymers with higher softening temperatures, especially polymers such as triacetyl cellulose and cellulose acetate butyrate are used. preferable. In addition, as needed, said binder can be used in combination of 2 or more type.
Such a binder is used in an effective range to function as a binder. The effective range can be easily determined by one skilled in the art. For example, as an index when at least the organic silver salt is retained in the photosensitive layer, the ratio of the binder to the organic silver salt is preferably in the range of 15: 1 to 1: 2, particularly 8: 1 to 1: 1. The binder amount of the photosensitive layer is 1.5 to 6 g / m.²It is preferable that More preferably 1.7 to 5 g / m²It is. 1.5g / m²If it is less than 1, the density of the unexposed area will be significantly increased, and it may be unusable.
[0065]
(Organic gelling agent)
The photosensitive layer may contain an organic gelling agent. In addition, the organic gelling agent referred to here is a function of adding a yield value to the system by adding it to an organic liquid such as polyhydric alcohols, and eliminating or reducing the fluidity of the system. The compound which has this.
[0066]
(Water-based coating)
When the coating liquid for forming the photosensitive layer of the salt photothermographic dry imaging material contains a polymer latex dispersed in water, it is preferable that 50% by mass or more of the total binder in the coating liquid is a polymer latex dispersed in water.
The “polymer latex” according to the present invention is a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. The dispersion state is that the polymer is emulsified in a dispersion medium, emulsion-polymerized, micelle-dispersed or partially hydrophilic structure in the polymer molecule and the molecular chain itself is molecularly dispersed. Any may be sufficient.
The average particle size of the dispersed particles is preferably 1 to 50000 nm, more preferably about 5 to 1000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.
The polymer latex may be a so-called core / shell type latex in addition to a normal uniform polymer latex. In this case, it may be preferable to change the glass transition temperature between the core and the shell. The minimum film-forming temperature (MFT) of the polymer latex is preferably -30 to 90 ° C, more preferably about 0 to 70 ° C. Further, a film-forming auxiliary may be added to control the minimum film-forming temperature.
A film-forming aid, also called a plasticizer, is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of a polymer latex. For example, “Synthetic latex chemistry (written by Soichi Muroi, published by Kobunshi Shuppankai (1970)) "It is described in.
[0067]
Examples of the polymer species used for the polymer latex include acrylic resins, vinyl acetate resins, polyester resins, polyurethane resins, rubber resins, vinyl chloride resins, vinylidene chloride resins, polyolefin resins, and copolymers thereof. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is 5,000 to 1,000,000, preferably about 10,000 to 100,000 in terms of number average molecular weight. When the molecular weight is too small, the mechanical strength of the photosensitive layer is insufficient, and when the molecular weight is too large, the film forming property is poor, which is not preferable.
The polymer latex preferably has an equilibrium water content of 0.01 to 2% by mass or less, more preferably 0.01 to 1% by mass at 25 ° C. and 60% RH. For the definition and measurement method of the equilibrium moisture content, for example, “Polymer Engineering Course 14, Polymer Material Testing Method (Edited by Polymer Society, Jinshokan)” can be referred to.
[0068]
Specific examples of the polymer latex include, for example, methyl methacrylate / ethyl acrylate / methacrylic acid copolymer latex, methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer latex, styrene / butadiene / acrylic acid copolymer latex, styrene / Examples include butadiene / divinylbenzene / methacrylic acid copolymer latex, methyl methacrylate / vinyl chloride / acrylic acid copolymer latex, and vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer latex.
These polymers may be used alone or in combination of two or more as required. As a polymer seed | species of a polymer latex, what contains about 0.1-10 mass% of carboxylic acid components like an acrylate or a methacrylate component is preferable.
Furthermore, if necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose or the like may be added within a range of 50% by mass or less of the total binder. The amount of these hydrophilic polymers added is preferably 30% by mass or less of the total binder in the photosensitive layer.
[0069]
In the preparation of the coating solution for forming a photosensitive layer, the organic silver salt and the aqueous dispersed polymer latex may be added in any order, or may be added at the same time. Later.
Furthermore, it is preferable that an organic silver salt and further a reducing agent are mixed before adding the polymer latex.
In addition, after mixing the organic silver salt and the polymer latex, if the temperature for aging is too low, the coating surface shape is impaired, and if it is too high, there is a problem that the fog rises, so the coating solution after mixing is 30 ° C. to 65 ° C. It is preferable that the above time is elapsed. Furthermore, it is preferable to make it age at 35 to 60 degreeC, and it is especially preferable to age at 35 to 55 degreeC. In order to maintain the temperature in this way, it is sufficient to keep the temperature of the coating solution preparation tank or the like.
For coating the photosensitive layer forming coating solution, it is preferable to use a coating solution that has been mixed for 30 minutes to 24 hours after mixing an organic silver salt and an aqueous dispersed polymer latex, and more preferably 60 minutes to 60 minutes after mixing. It is to make it pass for 12 hours, It is especially preferable to use the coating liquid which passed for 120 minutes-10 hours.
Here, “after mixing” means after the organic silver salt and the aqueous polymer latex are added and the additive material is uniformly dispersed.
[0070]
[Crosslinking agent]
It is known that the use of a crosslinking agent for the binder improves filming and reduces development unevenness, but also has an effect of suppressing fog during storage and suppressing generation of printout silver after development. .
As the crosslinking agent, various crosslinking agents conventionally used for photographic materials, for example, aldehyde-based, epoxy-based, ethyleneimine-based, vinylsulfone-based, sulfone described in JP-A-50-96216 are disclosed. An acid ester-based, acryloyl-based, carbodiimide-based, or silane compound-based crosslinking agent can be used, but preferred are isocyanate-based compounds, silane compounds, epoxy compounds, and acid anhydrides shown below.
The isocyanate-based crosslinking agent and thioisocyanate-based crosslinking agent represented by the following general formula [8], which is one of the preferred ones, will be described below.
[0071]
General formula [8]
X = C = N−L− (N = C = X) v
In the formula, v is 1 or 2, L is a divalent or trivalent linking group which can be an alkylene, alkenylene, arylene group or alkylarylene group, and X is an oxygen or sulfur atom.
In the compound represented by the general formula [8], the aryl ring of the arylene group may have a substituent. Examples of preferred substituents are halogen atoms (for example, bromine atom or chlorine atom), hydroxy groups, amino groups, carboxyl groups, alkyl groups and alkoxy groups.
[0072]
The isocyanate-based crosslinking agent includes isocyanates having at least two isocyanate groups and adducts thereof (adducts), and more specifically, aliphatic diisocyanates and aliphatic diisocyanates having a cyclic group. Benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates, triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates, for example, divalent or trivalent with isocyanates Examples include adducts with polyalcohols.
Specific examples include isocyanate compounds described on pages 10 to 12 of JP-A-56-5535, and these can be used.
Note that the adduct of isocyanate and polyalcohol has particularly high ability to improve interlayer adhesion and prevent layer peeling, image shift, and bubble generation. Such isocyanates may be placed in any part of the photothermographic material. For example, in the support (especially when the support is paper, it can be included in the size composition), photosensitive layer, surface protective layer, intermediate layer, antihalation layer, subbing layer, etc. It can be added to any layer on the side and can be added to one or more of these layers.
In addition, as the thioisocyanate-based crosslinking agent that can be used in the present invention, compounds having a thioisocyanate structure corresponding to the above isocyanates are also useful.
The amount of the crosslinking agent used in the present invention is in the range of 0.001 to 2 mol, preferably 0.005 to 0.5 mol, with respect to 1 mol of silver.
As described above, the isocyanate compound and thioisocyanate compound to be used are preferably compounds that function as the above-mentioned crosslinking agent. However, in the above general formula [8], v is 0, that is, only one functional group is present. The result which may be a compound which has is obtained.
[0073]
Examples of the silane compound that can be used as the crosslinking agent include compounds disclosed in Japanese Patent Application No. 12-077904.
[0074]
The epoxy crosslinking agent may be an epoxy compound having one or more epoxy groups, and there is no limitation on the number of epoxy groups, molecular weight, and the like. The epoxy group is preferably contained in the molecule as a glycidyl group via an ether bond or an imino bond. Moreover, any of a monomer, an oligomer, a polymer, etc. may be sufficient as an epoxy compound, and the number of the epoxy groups which exist in a molecule | numerator is about 1-10 normally, Preferably it is 2-4. When the epoxy compound is a polymer, it may be a homopolymer or a copolymer, and the particularly preferred range of the number average molecular weight Mn is about 2000 to 20000.
The epoxy compound can be added to any layer on the photosensitive layer side of the support, such as a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer, and an undercoat layer, and one or more of these layers can be added. Can be added. In addition, it can be added to any layer on the opposite side of the support from the photosensitive layer. In the silver salt photothermographic dry imaging material having photosensitive layers on both sides, any layer may be used.
[0075]
An acid anhydride that can be used as a crosslinking agent is a compound having at least one acid anhydride group represented by the following structural formula.
-CO-O-CO-
The acid anhydride is not particularly limited as long as it has one or more such acid anhydride groups, and the number, molecular weight, and the like of the acid anhydride group are not limited, but a compound represented by the general formula [B] is preferable.
[0076]
[Chemical 6]

In the general formula [B], Z represents an atomic group necessary for forming a monocyclic or polycyclic system.
The ring formed by Z may be unsubstituted or substituted. Examples of the substituent include an alkyl group (eg, methyl group, ethyl group, hexyl group, etc.), an alkoxy group (eg, methoxy group, ethoxy group, octyloxy group, etc.), an aryl group (eg, phenyl group, naphthyl group). , Tolyl group etc.), hydroxy group, aryloxy group (eg phenoxy group etc.), alkylthio group (eg methylthio group, butylthio group etc.), arylthio group (eg phenylthio group etc.), acyl group (eg acetyl group) , Propionyl group, butyryl group, etc.), sulfonyl group (eg, methylsulfonyl group, phenylsulfonyl group, etc.), acylamino group, sulfonylamino group, acyloxy group (eg, acetoxy group, benzoxy group, etc.), carboxyl group, cyano group, A sulfo group and an amino group are included. As the substituent, those not containing a halogen atom are preferable.
These acid anhydrides may be used alone or in combination of two or more. The amount added is not particularly limited, but 1 × 10^-6~ 1x10^-2Mol / m²Is preferred, more preferably 1 × 10^-Five~ 1x10^-3Mol / m²Range.
In the present invention, the acid anhydride can be added to any layer on the photosensitive layer side of the support, such as a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer, and an undercoat layer. It can be added to two or more layers. Moreover, you may add to the same layer as the said epoxy compound.
Photothermographic dry imaging materials form photographic images by heat development processing, and can be used for reducible silver sources (organic silver salts), photosensitive silver halide grains, reducing agents, and adjusting the color of silver as required. It is preferable to contain the toning agent to be dispersed in a normal (organic) binder matrix.
[0077]
[Toning agent]
Examples of toning agents suitable for use are RD17029, U.S. Pat. Nos. 4,123,282, 3,994,732, 3,846,136 and For example, the following are disclosed.
Imides (eg, succinimide, phthalimide, naphthalimide, N-hydroxy-1,8-naphthalimide, etc.); mercaptans (eg, 3-mercapto-1,2,4-triazole, etc.); phthalazinone derivatives or metals of these derivatives Salts (for example, phthalazinone, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3-dihydro-1,4-phthalazinedione); Combinations of phthalic acids (eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic acid); phthalazine and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid Derivatives and anhydrides thereof (eg phthalic acid, 4-methyl Tal acid, 4- combination of nitrophthalic acid and at least one compound selected from anhydrides) of tetrachlorophthalic acid and the like. A particularly preferred colorant is a combination of phthalazinone or phthalazine with phthalic acids and phthalic anhydrides.
Conventionally, with regard to the color tone of an output image for medical diagnosis, it is said that a cold tone image tone makes it easier for an X-ray photograph reader to obtain a more accurate diagnostic observation result of a recorded image. Here, the cool image tone is a pure black tone or a bluish black tone with a black image, and the warm image tone is a warm black tone with a brown image on a black image. Say.
[0078]
The terms “more cold” and “more warm” regarding the color tone are determined by the hue angle hab at the minimum density Dmin and the optical density D = 1.0. Hue angle hab is a color space with a perceptually uniform rate recommended in 1976 by the International Commission on Illumination (CIE).^*a^*b^*Color coordinate a of color space^*, B^*Is obtained by the following equation.
hab = tan^-1(B^*/ A^*)
In the present invention, the preferred range of hab is 180 ° <hab <270 °, more preferably 200 ° <hab <270 °, and most preferably 220 ° <hab <260 °.
In the present invention, the preferred hab range is 180 ° <hab <270 °, more preferably 200 ° <hab <270 °, and most preferably 220 ° <hab <260 °.
[0079]
[Matting agent]
Contains a matting agent on the photosensitive layer side of the photothermographic dry imaging material and on the surface layer of the non-photosensitive layer provided on the opposite side of the photosensitive layer, for handling before development and preventing damage to the image after thermal development. It is preferable to contain 0.1-30 mass% with respect to a binder.
The material of the matting agent may be either organic or inorganic. For example, silica as described in Swiss Patent No. 330,158 and the like, glass powder as described in French Patent No. 1,296,995 and the like, British Patent No. 1,173,181, which are inorganic substances, Starch described in U.S. Pat.No. 2,322,037 and the like, Belgian Patent No. 625,451, which is an organic substance such as carbonates such as alkaline earth metals, cadmium and zinc described in Starch derivatives described in British Patent No. 981,198, etc., polyvinyl alcohol described in Japanese Patent Publication No. 44-3643, etc., polystyrene or polymethacrylate described in Swiss Patent No. 330,158, etc., Polyacrylonitrile described in U.S. Pat. No. 3,079,257, etc., and polycarbonate described in U.S. Pat. It can be used as bets agent.
The matting agent 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.
Here, the variation coefficient of the particle size distribution is a value represented by the following equation.
Coefficient of variation of particle size distribution (%) = [(standard deviation of particle size) / (average value of particle size)] × 100
The matting agent may be added by a method in which the matting agent is previously dispersed in the coating solution, or may be sprayed after the coating solution is applied and before the drying is completed. Moreover, when adding several types of mat agents, you may use both methods together.
[0080]
Examples of the support material used for the photothermographic dry imaging material include various polymer materials, glass, wool cloth, cotton cloth, paper, metal (for example, aluminum, etc.), etc. In consideration, a material that can be processed into a flexible sheet or roll is preferable.
Accordingly, the support is preferably a plastic film (for example, cellulose acetate film, polyester film, polyethylene terephthalate film, polyethylene naphthalate film, polyamide film, polyimide film, cellulose triacetate film, or polycarbonate film). An axially stretched polyethylene terephthalate film is particularly preferred.
The thickness of the support is preferably 50 to 300 μm, and preferably 70 to 180 μm.
[0081]
[Antistatic agent]
In the photothermographic dry imaging material, a conductive compound such as a metal oxide and / or a conductive polymer can be included in the constituent layer 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. As the conductive compound, a conductive compound described in US Pat. No. 5,244,773, columns 14 to 20 is preferably used.
[0082]
[Layer structure]
The photothermographic dry imaging material 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. For example, a protective layer is provided on the photosensitive layer for the purpose of protecting the photosensitive layer, and the opposite surface of the support is adhered between the photothermographic dry imaging material or between the photothermographic dry imaging material and the roll. In order to prevent this, a back coat layer is preferably provided. As the binder used in these protective layers and back coat layers, polymers having a glass transition point higher than that of the heat-developable layer and less likely to be scratched or deformed, for example, polymers such as cellulose acetate and cellulose acetate butyrate are those described above. Selected from binders.
In order to adjust the gradation, two or more photosensitive layers may be provided on one side of the support or one or more layers on both sides of the support.
[0083]
[dye]
In photothermographic dry imaging materials, a filter layer is formed on the same side as or opposite to the photosensitive layer in order to control the amount of light transmitted through the photosensitive layer or the wavelength distribution, or the photosensitive layer contains a dye or pigment. It is preferable.
As the dye, known compounds that absorb light in various wavelength regions can be used depending on the color sensitivity of the photothermographic dry imaging material.
For example, when a photothermographic dry imaging material is used as an image recording material using infrared light, a squarylium dye having a thiopyrylium nucleus as disclosed in Japanese Patent Application No. 11-255557 (hereinafter referred to as thiopyrylium squarylium). And a squarylium dye having a pyrylium nucleus (hereinafter sometimes referred to as a pyrylium squarylium dye) (hereinafter collectively referred to as a croconium dye), and a thiopyrylium crocodile similar to a squarylium dye. It is also preferable to use a nium dye or a pyrylium croconium dye.
The squarylium dye is a dye having 1-cyclobutene-2-hydroxy-4-one in the molecular structure, and the croconium dye is 1-cyclopentene-2-hydroxy-4,5-dione in the molecular structure. It is a dye having. Here, the hydroxy group may be dissociated.
As the dye, the compounds described in JP-A-8-201959 are also preferable.
[0084]
[Coating technology]
The silver salt photothermographic dry imaging material may be formed by preparing a coating solution in which the above-described constituent layers are dissolved or dispersed in a solvent, applying a plurality of these coating solutions simultaneously, and then performing a heat treatment. preferable. Here, “multiple simultaneous multi-layer coating” means that a coating solution for each constituent layer (for example, photosensitive layer, protective layer) is prepared, and each layer is repeatedly coated and dried when it is coated on a support. Rather, it means that the constituent layers are formed in a state where the simultaneous multi-layer coating and drying steps can be performed simultaneously. Here, the simultaneous multilayer coating is to provide an upper layer before the residual amount of all the solvents in the lower layer becomes 70% by mass or less.
[0085]
There are no particular limitations on the method of applying multiple layers of each constituent layer simultaneously, and for example, a known method such as a bar coater method, curtain coating method, dipping method, air knife method, hopper coating method, or extrusion coating method is used. be able to. Of these, a pre-weighing type coating method called an extrusion coating method is more preferable. Since the extrusion coating method does not volatilize on the slide surface unlike the slide coating method, it is suitable for precision coating and organic solvent coating. Although this coating method has been described on the side having the photosensitive layer, the same applies to the case of coating with undercoating when providing the backcoat layer.
In the present invention, the amount of coated silver is preferably selected in accordance with the purpose of use of the silver salt photothermographic dry imaging material. However, when the purpose is to obtain a medical image, 0.6 g / m²2.5 g / m or more²The following is preferred. Furthermore, 0.8 g / m²1.5 g / m or more² The following is preferred. Of the silver coating amount, those derived from silver halide preferably occupy 2% to 18%, more preferably 5% to 15%, based on the total silver amount.
The coating density when using silver halide grains of 0.01 μm or more (equivalent particle diameter equivalent to sphere) is 1 × 10¹⁴Pieces / m²1 × 10 or more¹⁸Pieces / m²The following is preferred. Furthermore, 1x10¹⁵Pieces / m²1 × 10 or more¹⁷Pieces / m²The following is preferred.
When non-photosensitive long-chain aliphatic carboxylate silver is used, the coating density of non-photosensitive long-chain aliphatic carboxylate silver halide grains 1 of 0.01 μm or more (equivalent sphere equivalent particle diameter) used. 1 x 10 per piece^-17g or more 1 × 10^-15g or less, and further 1 × 10^-16g or more 1 × 10^-14g or less is preferable.
When coated under the conditions within the above range, it is preferable from the viewpoint of the optical maximum density of the silver image per fixed coated silver amount, that is, the silver coating amount (covering power) and the color tone of the silver image. Results are obtained.
[0086]
[Development conditions]
The development conditions of the silver salt photothermographic dry imaging material vary depending on the equipment, apparatus or means used, but it is typically done by heating the imagewise exposed photothermographic dry imaging material. The latent image obtained after exposure heats the photothermographic material at a moderately high temperature (for example, about 80 to 200 ° C., preferably about 100 to 200 ° C.) for a sufficient time (generally about 1 second to about 2 minutes). It can develop by doing.
When the heating temperature is 80 ° C. or lower, sufficient image density cannot be obtained in a short time. When the heating temperature is 200 ° C. or higher, the binder melts and is transferred to a roller. Also has an adverse effect. By heating, a silver image is generated by an oxidation-reduction reaction between an organic silver salt (which functions as an oxidizing agent) and a reducing agent. This reaction process can proceed without any supply of treatment liquid such as water from the outside.
A typical heating means such as a heat generator using a hot plate, an iron, a hot roller, carbon, white titanium, or the like can be used as an apparatus, device, or means for heating. The silver salt photothermographic dry imaging material provided with the protective layer is heated by bringing the surface having the protective layer into contact with the heating means in order to achieve uniform heating, thermal efficiency, and workability. Preferably, the surface is conveyed while being brought into contact with a heat roller, and is heated and developed.
The silver salt photothermographic dry imaging material has a unit length of diffusion density (Y-axis) and common logarithmic exposure (X-axis) obtained by heat development at a heating temperature of 123 ° C. and a development time of 13.5 seconds. In the characteristic curve shown on the orthogonal coordinates with the same, it is preferable that the average gradation of 0.25 to 2.5 in the optical density with diffused light is 2.0 to 4.0. By adjusting the sensitivity of the photosensitive silver halide grains, the applied silver amount, the layer configuration, and the like, it is possible to obtain an image with high diagnostic recognizability.
[exposure]
In the present invention, the silver salt photographic light-sensitive material is exposed by fluorescence emitted from the radiation image conversion panel of the present invention upon irradiation with radiation energy. The color sensitivity of the silver salt photographic light-sensitive material to be used is preferably appropriate for the wavelength of fluorescence emitted by the radiation image conversion panel.
[0087]
[Solvent content]
The silver salt photothermographic dry imaging material contains 5 to 1000 mg / m of solvent at the time of development.²It is preferable to contain in the range. More preferably, it is the range of 100-500 mg. By doing so, high sensitivity, low fog and maximum density can be obtained.
Examples of solvents that can be used include ketones such as acetone, methyl ethyl ketone, and isophorone, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, and benzyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol. , Glycols such as hexylene glycol, ether alcohols such as ethylene glycol monomethyl ether and diethylene glycol monoethyl ether, ethers such as isopropyl ether, esters such as ethyl acetate and butyl acetate, chlorides such as methylene chloride and dichlorobenzene Substances, hydrocarbons and the like. In addition, water, formamide, dimethylformamide, toluidine, tetrahydrofuran, acetic acid and the like can be used. However, the solvent that can be used is not limited to these. These solvents can be used alone or in combination of several kinds.
In addition, the said solvent contained in a silver salt photothermographic dry imaging material can be contained by changing the temperature conditions etc. in the drying process etc. after an application | coating process. Moreover, the content can be adjusted by changing the conditions.
The content of the solvent can be measured by gas chromatography under conditions suitable for detecting the contained solvent.
[0088]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
Example 1
(Preparation of phosphor particles Z1 to Z3)
Yttrium Y nitrate, gadolinium Gd nitrate, and europium Eu nitrate are mixed in water so that the mass ratio of yttrium Y, gadolinium Gd, and europium Eu is the ratio shown in Table 1, and the dissolved aqueous solution is 85 ° C., 1 Heated for 0.0 hours, an aqueous solution containing 1.5 ml of hydrogen peroxide (30%) and 500 g of urea was added and further heated to precipitate spherical particles of a rare earth element basic carbonate. The precipitated mixed rare earth element basic carbonate was then solid-liquid separated to obtain spherical particles of a rare earth element basic carbonate phosphor. The spherical particles of the basic carbonate were further fired at 750 ° C. in an oxidizing atmosphere to obtain spherical fine particle phosphors Z1 to Z3 made of a rare earth oxide. Table 1 shows the crystallite size, average particle diameter, and fluorescence wavelength of the obtained spherical fine particle phosphors Z1 to Z3.
[0089]
[Table 1]

[0090]
(Manufacture of radiation image conversion panels P1 to P3)
―Preparation of phosphor layer forming coating solution―
Spherical fine particle phosphor Z1 200 g, binder [polyurethane-based thermoplastic elastomer Demolac TPKL-5-2625 (solid content 40%) (manufactured by Sumitomo Bayer Urethane Co., Ltd.)] 20 g, nitrocellulose (nitrification degree 11.5%) 2 g Methyl ethyl ketone solvent was added to the mixture and dispersed with a propeller mixer to prepare a coating solution for forming a phosphor layer having a viscosity of 25 ps (25 ° C.) (binder / phosphor ratio = 1/22).
―Preparation of coating solution for undercoat layer formation―
90 g of a soft acrylic resin (solid content) and 60 g of nitrocellulose were dispersed and mixed with methyl ethyl ketone to prepare a dispersion having a viscosity of 3 to 6 ps (25 ° C.).
-Production of radiation image conversion panels P1-P3-
A polyethylene terephthalate base (support) having a thickness of 220 μm kneaded with titanium dioxide is placed horizontally on a glass plate, and the above undercoat layer-forming coating solution is uniformly applied onto the support using a doctor blade, and then 25 ° C. The temperature was gradually raised to 100 ° C. to dry the coating film, and an undercoat layer was formed on the support. The thickness of the coating film was 15 μm.
On top of this, the above phosphor layer-forming coating solution was uniformly applied and dried to a thickness of 150 μm using a doctor blade, and then compressed. Compression is 300 Kgw / cm using a calendar roll.²At a temperature of 80 ° C. After this shrinkage, a transparent protective layer having a thickness of 3 μm was formed by the method described in Example 1 of JP-A-6-75097 to produce a radiation image conversion panel P1.
Radiation image conversion panels P2 and P3 were produced in the same manner as the radiation image conversion panel P1, except that the spherical fine particle phosphors Z2 and Z3 were used instead of the spherical fine particle phosphor Z1.
[0091]
(Preparation of photosensitive material F100)
<Preparation of undercoated photographic support>
8 W / m on both sides of a commercially available biaxially stretched heat-fixed polyethylene terephthalate (PET) film with a blue color of 0.170 (measured with a Densitometer PDA-65 manufactured by Konica Corporation) with an optical density of 175 μm.²・ Corona discharge treatment was performed for one minute, and the following undercoat coating solution a-1 was applied and dried on one surface to a dry film thickness of 0.8 μm to form an undercoat layer A-1. The following undercoat coating solution b-1 was applied to the side surface so as to have a dry film thickness of 0.8 μm and dried to form an undercoat layer B-1.
<< Undercoat coating liquid a-1 >>

Finish to 1L with water
<< Undercoating liquid b-1 >>

Finish to 1L with water
Subsequently, 8 W / m on the upper surface of the undercoat layer A-1 and the undercoat layer B-1.²・ Corona discharge was applied, and on the undercoat layer A-1, the following undercoat upper layer coating solution a-2 was applied and dried to a dry film thickness of 0.1 μm to form the undercoat upper layer A-2. Then, on the undercoating layer B-1, the following undercoating upper layer coating solution b-2 is applied and dried so as to have a dry film thickness of 0.8 μm to form an undercoating upper layer B-2 having an antistatic function. did.
[0092]
<< Undercoating upper layer coating liquid a-2 >>
Gelatin 0.4g / m²Mass to become
C-1 0.2g
C-2 0.2g
C-3 0.1g
Silica particles (average particle size 3μm) 0.1g
Finish to 1L with water
<< Undercoating Upper Layer Coating Liquid b-2 >>
C-4 60g
Latex liquid containing C-5 as a component (solid content 20%) 80g
Ammonium sulfate 0.5g
C-6 12g
Polyethylene glycol (weight average molecular weight 600) 6g
Finish to 1L with water
[0093]
[Chemical 7]

[0094]
[Chemical 8]

[0095]
<Application on the back side>
While stirring 830 g of methyl ethyl ketone (MEK), 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. Next, 0.30 g of infrared dye-1 was added to the resulting solution, and 4.5 g of a fluorine-based active agent (Asahi Glass Co., Surflon KH40) dissolved in 43.2 g of methanol and a fluorine-based active agent ( Dainippon Ink, Megafag F120K) 2.3 g was added and stirred well until dissolved. Finally, 75 g of silica (WR Grace, Syloid 64X6000) 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 side.
[0096]
[Chemical 9]

The coating solution for the back surface side thus prepared was applied on an undercoat upper layer and dried by an extrusion coater so that the dry film thickness was 3.5 μm. Drying was performed over 5 minutes using a drying air having a drying temperature of 100 ° C. and an outdoor temperature of 10 ° C.
[0097]
<Coating on the photosensitive layer side>
<< Preparation of photosensitive silver halide emulsion A >>
Solution (A1)
Phenylcarbamoylated gelatin 88.3g
Compound (A) (10% methanol aqueous 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
Compound (A): HO (CH₂CH₂O)_n-(CH (CH_Three) CH₂O)₁₇-(CH₂CH₂O)_mH (m + n = 5-7)
[0098]
Using a mixing stirrer disclosed in Japanese Patent Publication Nos. 58-58288 and 58-58289, a 1/4 amount of the solution (B1) and a total amount of the solution (C1) were added to the solution (A1) at a temperature of 45 ° C., pAg 8.09. While being controlled, nucleation was carried out by adding 4 minutes 45 seconds by the simultaneous mixing method. After 1 minute, the entire amount of solution (F1) was added. The pAg was appropriately adjusted using (E1). After 6 minutes, 3/4 amount of the solution (B1) and the total amount of the solution (D1) were added over 14 minutes and 15 seconds by the simultaneous mixing method while controlling the temperature 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 was 1161 g per mole of silver to obtain a silver halide emulsion.
This emulsion was monodisperse cubic silver iodobromide grains having an average grain size of 0.058 μm, a grain size distribution variation coefficient of 12%, and a (100) plane ratio of 92%.
Next, 240 ml of sulfur sensitizer S-5 (0.5% methanol solution) was added to the emulsion, and gold sensitizer Au-5 (0.5% equivalent to 2/20 mol of this sensitizer) was added. (Ethanol solution) was added and stirred at 55 ° C. for 120 minutes for chemical sensitization to obtain photosensitive silver halide emulsion A.
[0099]
<< Preparation of powdered organic silver salt A >>
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 in 4720 ml of pure water at 80 ° C. Next, 540.2 ml of a 1.5 M 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. While maintaining the temperature of the 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 1M silver nitrate 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 draining were repeated until the conductivity of the drainage reached 2 μS / cm, and centrifugal dehydration was performed. The moisture content of the obtained cake-like organic silver salt becomes 0.1% depending on the operating conditions of the nitrogen gas atmosphere and the hot air temperature of the dryer inlet using an airflow dryer flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.). To obtain a dried powdered organic silver salt A.
An infrared moisture meter was used to measure the moisture content of the organic silver salt composition.
[0100]
<< Preparation of Preliminary Dispersion A >>
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 A was gradually added while stirring with a dissolver DISPERMAT CA-40M manufactured by VMA-GETZMANN. Preliminary dispersion A was prepared by thorough mixing.
[0101]
<< Preparation of photosensitive emulsion dispersion 1 >>
Media type disperser DISPERMAT SL- filled with 80% of the internal volume of 0.5 mm diameter zirconia beads (Torayserum manufactured by Toray) so that the residence time in the mill is 1.5 minutes using a pump. Photosensitive emulsion dispersion 1 was prepared by supplying to C12EX type (VMA-GETZMANN) and dispersing at a mill peripheral speed of 8 m / s.
<< 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.
[0102]
Embedded image

[0103]
<< Preparation of infrared sensitizing dye liquid A >>
31.3 ml of 19.2 mg of infrared sensitizing dye (SD-1), 1.488 g of 2-chloro-benzoic acid, 2.779 g of Stabilizer-2 and 365 mg of 5-methyl-2-mercaptobenzimidazole Infrared sensitizing dye liquid A was prepared by dissolving in MEK in the dark.
[0104]
Embedded image

[0105]
<< 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 Was dissolved in 110 g of MEK to obtain an additive solution a.
<< Preparation of additive liquid b >>
3.56 g of antifoggant-2, 3.43 g of phthalazine were dissolved in 40.9 g of MEK to obtain additive liquid b.
[0106]
Embedded image

[0107]
<< Preparation of photosensitive layer coating solution >>
In an inert gas atmosphere (97% nitrogen), the photosensitive emulsion dispersion 1 (50 g) and 15.11 g of MEK were kept at 21 ° C. with stirring, and 390 μl of antifoggant-1 (10% methanol solution) was added. Stir for 1 hour. Further, 494 μl of calcium bromide (10% methanol solution) was added and stirred for 20 minutes. Subsequently, 167 ml of the 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 (Monsanto Butvar B-79) was added and stirred for 30 minutes, and then 1.084 g of tetrachlorophthalic acid (9.4 mass% MEK solution) was added. Stir for 15 minutes. While continuing to stir, 12.43 g of additive a, 1.6 ml of Desmodur N3300 / Mobey aliphatic isocyanate (10% MEK solution), 4.27 g of additive b were sequentially added and stirred. A photosensitive layer coating solution was obtained.
[0108]
<Preparation of matting agent dispersion>
Dissolve 7.5 g of cellulose acetate butyrate (Eastman Chemical, CAB171-15) in 42.5 g of MEK, add 5 g of calcium carbonate (Speciality Minerals, Super-Pflex 200), and add 8000 rpm with a dissolver type homogenizer. For 30 min to prepare a matting agent dispersion.
[0109]
<< Preparation of surface protective layer coating liquid >>
While stirring 865 g of MEK (methyl ethyl ketone), 96 g of cellulose acetate butyrate (Eastman Chemical, CAB171-15), 4.5 g of polymethylmethacrylic acid (Rohm & Haas, Paraloid A-21), the following vinyl sulfone compound 1.5 g, 1.0 g of benztriazole and 1.0 g of a fluorine-based activator (Asahi Glass Co., Surflon KH40) 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.
Vinylsulfone compounds
(CH₂= CHSO₂CH₂)₂CHOH
[0110]
<< Coating on the photosensitive layer side >>
Photosensitive material F100 was produced by simultaneously applying the photosensitive layer coating solution and the surface protective layer coating solution using an extrusion coater. For coating, the photosensitive layer has a coated silver amount of 1.9 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 75 ° C. and a dew point temperature of 10 ° C.
[0111]
(Preparation of photosensitive material F101A)
<< Preparation of additive liquid c >>
5.0 g of the following silver saving agent was dissolved in 45.0 g of MEK to obtain an additive solution c.
[0112]
Embedded image

<< Preparation of photosensitive layer coating solution A >>
In an inert gas atmosphere (nitrogen 97%), photosensitive emulsion dispersion 1 (50 g) and 15.11 g of MEK were kept at 21 ° C. with stirring, and 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 a gold sensitizer Au-5 equivalent to 1/20 mole of the chemical sensitizer S-5 was added, and further 20 minutes. Stir. Subsequently, 167 ml of a stabilizer solution was added and stirred for 10 minutes, and then 1.32 g of 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 (Monsanto Butvar B-79) was added and stirred for 30 minutes, and then 1.084 g of tetrachlorophthalic acid (9.4 mass% MEK solution) was added. Stir for 15 minutes. While further stirring, 12.43 g of additive liquid a, 1.6 ml of Desmodur N3300 / Mobey aliphatic isocyanate (10% MEK solution), 4.27 g of additive liquid b were sequentially added and stirred. A photosensitive layer coating solution A was obtained.
[0113]
Embedded image

[0114]
<< Preparation of photosensitive layer coating solution B >>
In an inert gas atmosphere (97% nitrogen), the photosensitive emulsion dispersion 1 (50 g) and 15.11 g of MEK were kept at 21 ° C. with stirring, and the chemical sensitizer S-5 (0.5% methanol solution) was kept. ) 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 a gold sensitizer Au-5 corresponding to 1/20 mole of the chemical sensitizer S-5 was added, and further 20 minutes. Stir. 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 (Monsanto Butvar B-79) was added and stirred for 30 minutes, and then 1.084 g of tetrachlorophthalic acid (9.4 mass% MEK solution) was added. Stir for 15 minutes. While continuing to stir, 12.43 g of additive a, 1.6 ml of Desmodur N3300 / Mobayic aliphatic isocyanate (10% MEK solution), 4.27 g of additive b, 10.0 g of additive c Were sequentially added and stirred to obtain photosensitive layer coating solution B.
[0115]
(Preparation of photosensitive material F101A)
Photosensitive material F101A was produced in the same manner as photosensitive material F100, except that the photosensitive layer surface side coating was replaced with photosensitive layer surface side coating 101A described below.
<< Photosensitive layer side coating 101A >>
The photosensitive layer coating solution A, the photosensitive layer coating solution B, and the surface protective layer coating solution were formed by simultaneous multilayer coating using an extrusion coater to form two layers of photosensitive layer and one layer of surface protective layer. The photosensitive layer a formed from the photosensitive layer coating solution A is coated with a coating silver amount of 0.7 g / m.²The photosensitive layer b formed from the photosensitive layer coating solution B has a coating 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.
(Preparation of photosensitive material F101B)
Photosensitive material F101B was produced in the same manner as photosensitive material F100, except that the coating on the photosensitive layer surface side was replaced with the following photosensitive layer surface coating 101B.
<< Photosensitive layer side coating 101B >>
The photosensitive layer coating solution A and the surface protective layer coating solution were extruded (extrusion) using a coater, and a total of two layers, a photosensitive layer a and one surface protective layer, were simultaneously formed by multilayer coating. In addition, a photosensitive layer coating solution B and a surface protective layer coating solution are extruded on the opposite side of these two layers across the support, and a total of two layers of photosensitive layer b and one surface protective layer are formed using an extrusion coater. At the same time, it was formed by multilayer coating. 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.
[0116]
(Preparation of photosensitive material F102)
<< Preparation of organic silver salt dispersion >>
7 g of stearic acid, 4 g of arachidic acid, 36 g of behenic acid, and 187 ml of 1 mol / liter NaOH aqueous solution were added to 850 ml of distilled water with vigorous stirring at 90 ° C. and reacted for 120 minutes. After adding 71 ml of 1N nitric acid, 50 ml The temperature was lowered to ° C. Next, 125 ml of an aqueous solution of 21 g of silver nitrate was added over 100 seconds while stirring more vigorously, and left as it was for 20 minutes. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate reached 30 μS / cm. 100 g of PVA205 (polyvinyl alcohol manufactured by Kuraray Co., Ltd.) 10 mass% aqueous solution 100 g was added to the solid content thus obtained, water was further added to a total mass of 270 g, and then coarsely dispersed in an automatic mortar. A silver salt crude dispersion was obtained.
This organic silver salt crude dispersion was dispersed using a nanomizer (manufactured by Nanomizer Co., Ltd.) at a collision pressure of 98.07 MPa to obtain an organic silver salt dispersion.
The organic silver salt particles contained in the obtained organic silver salt dispersion were needle-like particles having an average minor axis of 0.04 μm, an average major axis of 0.8 μm, and a coefficient of variation of 30%.
[0117]
<< Preparation of reducing agent dispersion >>
To 100 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane (reducing agent) and 50 g of hydroxypropylcellulose, 850 g of water was added and mixed well to prepare a slurry. The slurry was placed in a vessel together with 840 g of zirconia beads having an average diameter of 0.5 mm, and dispersed for 5 hours with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) to obtain a reducing agent dispersion.
<< Preparation of organic polyhalide dispersion >>
To 50 g (0.127 mol) of tribromomethylsulfonylbenzene and 10 g of hydroxypropylcellulose, 940 g of water was added and mixed well to obtain a slurry. The slurry was placed in a vessel together with 840 g of zirconia beads having an average diameter of 0.5 mm, and dispersed for 5 hours with a disperser (sand grinder mill: manufactured by Imex Co., Ltd.) to obtain an organic polyhalide dispersion.
[0118]
<< Preparation of photosensitive silver halide emulsion >>
After dissolving 22 g of phthalated gelatin and 30 mg of potassium bromide in 1000 ml of water and adjusting the pH to 5.0 at a temperature of 35 ° C., 159 ml of an aqueous solution containing 18.6 g of silver nitrate and 0.9 g of ammonium nitrate and potassium bromide and iodine 159 ml of an aqueous solution containing potassium hydroxide in a molar ratio of 92: 8 was added over 10 minutes by the control double jet method while keeping pAg 7.7. Subsequently, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and 2 g of ammonium nitrate and an aqueous solution containing 10 μmol / liter of dipotassium hexachloroiridate and 1 mol / liter of potassium bromide at a pAg of 7.7 for 30 minutes by the control double jet method. After the addition, 1 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, and the pH was lowered to cause aggregation and sedimentation, followed by desalting. Thereafter, 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and pAg 8.2, and silver iodobromide grains (iodine content core 8 mol%, average 2 mol%, average size 0.05 μm, projected area variation coefficient 8%). , (100) cubic particles having a face ratio of 85%).
The silver halide grains thus obtained were heated to 60 ° C. and 85 μmol of sodium thiosulfate and 11 μmol of 2,3,4,5,6-pentafluorophenyldiphenylphosphine selenide per mol of silver, 15 μmol of tellurium compound, 3 μmoles of chloroauric acid and 270 μmol of thiocyanic acid were added and ripened for 120 minutes, then rapidly cooled to 40 ° C., then added with 100 μmol of sensitizing dye, stirred for 30 minutes, rapidly cooled to 30 ° C. Silver halide emulsion was obtained. The above 30 ° C. is taken as the preparation temperature of the silver halide emulsion.
[0119]
<Preparation of emulsion layer coating solution>
1350 g of an organic silver salt dispersion, 140 ml of a 20% by weight aqueous solution of PVA205, 37 ml of a 10% by weight aqueous solution of phthalazine, 220 g of a reducing agent dispersion, and 61 g of an organic polyhalide dispersion were added. Manufactured by Kogyo Co., Ltd .; SBR latex containing styrene and butadiene as main copolymerization components; average particle size of dispersed particles 0.1 to 0.15 μm, polymer equilibrium water content under conditions of 25 ° C. and 60% RH 0 .6 mass%) 1100 g was mixed, and then 120 g of the above photosensitive silver halide emulsion was mixed to prepare emulsion layer coating solutions 1 to 8. The solution pH was adjusted to pH 5.0 with 11 mol / liter sulfuric acid to obtain an emulsion layer coating solution.
[0120]
<Preparation of emulsion surface intermediate layer coating solution>
MP203 (Kuraray Co., Ltd., modified polyvinyl alcohol) 100 g was dissolved in 900 ml of water, and 2 ml of a 5% by weight aqueous solution of di (2-ethylhexyl) sulfosuccinate sodium salt was added to the emulsion surface intermediate layer coating solution. Got.
<Preparation of emulsion surface protective layer coating solution>
145 g of inert gelatin dissolved in 1110 ml of warm water, 400 g of 20% by weight polyethylacrylate latex, 57 ml of 1 mol / liter sulfuric acid, 10 ml of 5% by weight aqueous solution of sodium di (2-ethylhexyl) sulfosuccinate, phthalic acid 280 ml of a 10% by weight methanol solution was added to obtain an emulsion surface protective layer coating solution.
<Preparation of emulsion surface overcoat layer coating solution>
130 g of gelatin dispersion containing 12% by mass of polymethyl methacrylate fine particles (average particle size 2.5 μm) in 129 g of inert gelatin dissolved in 1650 ml of warm water, 65 ml of 1 mol / liter sulfuric acid, disulfosuccinate (2 -Ethylhexyl) flow rate ratio such that 2% by weight aqueous solution (hardener) of potassium chromium (III) sulfate 12 hydrate is 0.3 with respect to liquid 1 to which 20 ml of 5% by weight aqueous solution of ester sodium salt is added The emulsion surface overcoat layer coating solution was continuously prepared.
[0121]
<Preparation of back layer coating solution>
A solid base of N, N ′, N ″, N ″ ′-tetraethylguanidine and 4-carboxysulfonyl-phenylsulfone in a molar ratio of 1: 2 10 g of polyvinyl alcohol 10 g and water 88 g of sand grinder mill (Imex ( And a base solution was obtained. Basic dye precursor 2.1 g, acidic substance 7.9 g, 0.1 g (1.990 × 10^-FourMole), an organic solvent phase in which 10 g of antihalation dye and ethyl acetate were mixed and dissolved was mixed with an aqueous phase composed of 10 g of polyvinyl alcohol and 80 g of water, and emulsified and dispersed at room temperature to obtain a dye solution (average particle size 2.5 μm). . 39 g of the base solution thus obtained, 26 g of the dye solution, and 36 g of a 10% by weight polyvinyl alcohol aqueous solution were mixed to obtain a back layer coating solution.
[0122]
Embedded image

[0123]
<< Back layer protective layer coating solution >>
Back layer protection by dissolving 20 g of gelatin, 0.6 g of polymethyl methacrylate (average particle size 7 μm), 0.4 g of sodium dodecylbenzenesulfonate, and 1 g of X-22-2809 (a silicone compound manufactured by Shin-Etsu Silicone Co., Ltd.) in 480 g of water. A layer coating solution was obtained.
<< Preparation of undercoat coating liquid A >>
Polyester copolymer dispersion (Pesresin A-515GB (solid content 30%) manufactured by Takamatsu Yushi Co., Ltd.) (200 ml) was added polystyrene fine particles (average particle size 0.2 μm) 50 g and surfactant A (1 mass%) 20 ml. Then, distilled water was added to this to make 1000 ml of the undercoat coating solution A.
[0124]
Embedded image

[0125]
<< Preparation of undercoat coating liquid B >>
Distilled water (680 ml) and styrene-butadiene copolymer aqueous dispersion (styrene / butadiene / itaconic acid = 47/50/3 (mass ratio), concentration 30 mass%) 200 ml, polystyrene fine particles (average particle size 2.5 μm) 1 g was added, and distilled water was further added to make 1000 ml, thereby preparing an undercoat coating solution B.
<< Preparation of undercoat coating liquid C >>
10 g of inert gelatin is dissolved in 500 ml of distilled water, and 40 g of an aqueous dispersion (40% by mass) of tin oxide-antimony oxide composite fine particles described in JP-A-61-20033 is added thereto. Was added to make 1000 ml of the undercoat coating solution C.
<< Preparation of undercoat support >>
One side (photosensitive surface) of a 175 μm thick biaxially stretched polyethylene terephthalate support colored with the following blue dye is subjected to corona discharge treatment, and then the wet coating amount of the undercoat coating solution A is 5 ml / m using a bar coater.²And then dried at 180 ° C. for 5 minutes. The dry film thickness was about 0.3 μm. Next, after corona discharge treatment was applied to the back surface (back surface), the undercoat coating liquid B was applied at a wet coating amount of 5 ml / m using a bar coater.²Then, the coated film was applied to a dry film thickness of about 0.3 μm, dried at 180 ° C. for 5 minutes, and the undercoat coating liquid C was further applied thereon with a wet coating amount of 3 ml / m.²Then, it was applied so that the dry film thickness was about 0.03 μm and dried at 180 ° C. for 5 minutes to prepare an undercoat support.
[0126]
Embedded image

[0127]
(Preparation of photosensitive material F102)
On the back surface of the undercoat support, the back layer coating solution is added in an amount such that the optical density at 810 nm is 0.8, and the back layer protective layer coating solution is 50 g / m.²In Stephen F. Kistler, Peter M. et al. FIG. 11b., Page 427, “LIQUID FILM COATING” (CHAPMAN &amp; published by HALL, 1997) by Schweizer. After simultaneous multi-layer coating with the same coater as described in No. 1, the emulsion layer coating solution is 82 ml / m from the support side on the photosensitive surface.²The emulsion surface intermediate layer coating solution is 6.5 ml / m.²The emulsion surface protective layer coating solution is 12.5 ml / m²The emulsion surface overcoat layer coating solution is 12 ml / m.²Then, the coating was applied simultaneously and passed through a chilled zone at 10 ° C. (dew point of 0 ° C. or less), followed by drying with a wind of 30 ° C., 40% RH and a wind speed of 20 m / sec. The smoothness of the light-sensitive material F102 obtained in this way (the Beck smoothness was examined using the Oken type smoothness measurement described in J. TAPPI paper pulp test method No. 5) was 590 seconds on the emulsion surface and 80 seconds on the back surface. there were.
[0128]
-Invention-
<Exposure processing>
(Chest phantom)
Using an X-ray source of 120 kVp (3 mm thick aluminum transmission filter device), a chest phantom made by Kyoto Kagaku is placed at a distance of 140 cm, behind it is an anti-scattering grid with a grid ratio of 8: 1, and behind that is shown in Table 2. Radiation image conversion panels (P1, P2 and P3) and photosensitive materials (SR-ESC (manufactured by Konica Corporation), CM-H (manufactured by Konica Corporation), SD-P (manufactured by Konica Corporation), F100, An assembly with F101A, F101B and F102) was placed and exposed. (ACR standard 156 mammographic phantom)
Similarly, a mammography image was taken using an ACR standard 156 type mammographic phantom manufactured by RMI.
The ACR standard 156 type mammographic phantom contains 6 states of nylon fiber that mimics the fiber structure, 5 states of aluminum spec that mimics microcalcification, and 5 states of nylon fiber that mimics tumor.
<Development processing>
[Development processing of F100, F101A, F101B, and F102]
Using an automatic developing machine having a heat drum, heat development was performed at 110 ° C. for 15 seconds so that the protective layer of the photosensitive material and the drum surface were in contact with each other. The development processing was performed in a room adjusted to 23 ° C. and 50% RH.
[Development of SR-ESC]
Development processing was performed using SRX-502 (manufactured by Konica Corporation).
[CM-H development]
Development processing was performed using SRX-502 (manufactured by Konica Corporation).
[Development of SD-P]
Development processing was performed using Dry Pro722 (manufactured by Konica Corporation).
[0129]
[Evaluation of chest phantom image]
The finished photograph of the chest phantom was visually observed, and the graininess, sharpness, and silver tone were evaluated according to the following evaluation criteria.
[Evaluation criteria for graininess]
A: Almost inconspicuous
B: Slightly conspicuous
C: Slightly disturbing interpretation
D: Very conspicuous and difficult to interpret
[Evaluation criteria for sharpness]
A: Very sharp
B: Good but slightly blurred
C: Bokeh is noticeable and there is a slight hindrance to interpretation
D: Difficult to interpret due to blur
[0130]
[Evaluation of mammography images]
We evaluated how many nylon fibers mimicking the fiber structure, aluminum specs mimicking microcalcification, and nylon fibers mimicking tumors.
―Comparison―
Using an X-ray source of 120 kVp (a 3 mm thick aluminum transmission filter device), a chest phantom made by Kyoto Kagaku is placed at a distance of 140 cm, followed by an anti-scattering grid with a grid ratio of 8: 1, followed by radiation image conversion. An assembly of a panel (XG-S (manufactured by Konica Corporation)) and a photosensitive material (SR-ESC) is placed and exposed, and the photosensitive material (SR-ESC) is developed in the same manner as described above. Chest phantom images were evaluated.
Similarly, a mammography image was taken using an ACR standard 156 type mammographic phantom manufactured by RMI. In addition, the assembly of the radiation image conversion panel (MD-100 (made by Konica Corporation)) and the photosensitive material (CM-H) was used as the assembly of the radiation image conversion panel and the photosensitive material. The photosensitive material (CM-H) was developed in the same manner as described above, and an ACR standard 156 type mammographic phantom image was evaluated based on the above evaluation criteria.
The chest phantom made by Kyoto Science and the ACR standard 156 type mammographic phantom made by RMI were photographed with a digitizer (REGIUS MODEL150), and the image information was obtained using a laser imager (Dry Pro 722), and the films SD-P and F100 for dry laser. The photosensitive material (SD-P and F100) was developed in the same manner as described above, and the chest phantom image and the ACR standard 156 type mammographic phantom image were evaluated according to the above evaluation criteria.
The obtained results are shown together in Table 2.
[0131]
[Table 2]

As is apparent from Table 2, the assembly of the radiation image conversion panel and the silver salt photographic light-sensitive material of the present invention has improved graininess and sharpness and improved diagnosis of medical images as compared with the comparison.
[0132]
【The invention's effect】
According to the present invention, high sharpness and granularity are obtained, and the diagnostic performance of medical images is improved.

Claims (4)

Organic silver salt particles, photosensitivity using a radiation image conversion panel containing a phosphor having a crystallite size of 10 to 100 nm represented by the formula (Gd, M, Eu) ₂ O ₃ (M represents a rare earth element) An exposure method comprising exposing a silver salt photothermographic dry imaging material using silver halide grains and a reducing agent. 2. The exposure according to claim 1 , wherein the rare earth element M is at least one selected from yttrium Y, neodymium Nd, terbium Tb, dysprosium Dy, holmium Ho, erbium Er, thulium Tm, and ytterbium Yb. Method. 3. The exposure method according to claim 1 , wherein the phosphor is a particle having an average particle size of 0.2 to 5 [mu] m. An image forming method, wherein the silver salt photothermographic dry imaging material exposed by the exposure method according to any one of claims 1 to 3 is heated and developed at a temperature of 80 ° C to 200 ° C.