JP3844851B2 - Negative type image recording material - Google Patents

Description

【００２７】
【化２】

【００２８】
【化３】

【００２９】
【化４】

【００３０】
【化５】

【００３１】
式中、Ｌ₁ 〜Ｌ₈ は、同じであっても異なっていてもよく、ヒドロキシメチル基、メトキシメチル基又は、エトキシメチル基を示す。
ヒドロキシメチル基を有するフェノール誘導体は、対応するヒドロキシメチル基を有さないフェノール化合物（上記式においてＬ₁ 〜Ｌ₈ が水素原子である化合物）とホルムアルデヒドを塩基触媒下で反応させることによって得ることができる。この際、樹脂化やゲル化を防ぐために、反応温度を６０℃以下で行うことが好ましい。具体的には、特開平６−２８２０６７号、特開平７−６４２８５号等に記載されている方法にて合成することができる。
【００３２】
アルコキシメチル基を有するフェノール誘導体は、対応するヒドロキシメチル基を有するフェノール誘導体とアルコールを酸触媒下で反応させることによって得ることができる。この際、樹脂化やゲル化を防ぐために、反応温度を１００℃以下で行うことが好ましい。具体的には、欧州特許ＥＰ６３２００３Ａ１号等に記載されている方法にて合成することができる。
【００３３】
（ｂ）Ｎ−ヒドロキシメチル基、Ｎ−アルコキシメチル基若しくはＮ−アシルオキシメチル基を有する化合物としては、欧州特許公開（以下、ＥＰ−Ａと記載する）第０，１３３，２１６号、西独特許第３，６３４，６７１号、同第３，７１１，２６４号に開示された単量体及びオリゴマー−メラミン−ホルムアルデヒド縮合物並びに尿素−ホルムアルデヒド縮合物、ＥＰ−Ａ第０，２１２，４８２号に開示されたアルコキシ置換化合物等が挙げられる。
さらに好ましい例としては、例えば、少なくとも２個の遊離Ｎ−ヒドロキシメチル基、Ｎ−アルコキシメチル基若しくはＮ−アシルオキシメチル基を有するメラミン−ホルムアルデヒド誘導体が挙げられ、中でもＮ−アルコキシメチル誘導体が特に好ましい。
【００３４】
（ｃ）エポキシ系化合物としては、一つ以上のエポキシ基を含む、モノマー、ダイマー、オリゴマー、ポリマー状のエポキシ化合物を挙げることができる。例えば、ビスフェノールＡとエピクロルヒドリンとの反応生成物、低分子量フェノール−ホルムアルデヒド樹脂とエピクロルヒドリンとの反応生成物等が挙げられる。その他、米国特許第４，０２６，７０５号公報、英国特許第１，５３９，１９２号公報に記載され、使用されているエポキシ樹脂を挙げることができる。
【００３５】
本発明において、酸により架橋する架橋剤は全感光層固形分中、５〜７０重量％、好ましくは１０〜６５重量％の添加量で用いられる。酸により架橋する架橋剤の添加量が５重量％未満であると画像記録した際の画像部の膜強度が悪化し、また、７０重量％を越えると保存時の安定性の点で好ましくない。
これらの酸により架橋する架橋剤は単独で使用しても良く、また２種類以上を組み合わせて使用しても良い。
【００３６】
［（ロ）光又は熱により酸を発生する化合物］
本発明の感光層における光又は熱により酸を発生する化合物（以下、適宜、酸発生剤と称する）とは、光の照射又は１００℃以上の加熱により分解して酸を発生する化合物である。発生する酸としては、スルホン酸、塩酸等のｐＫａが２以下の強酸であることが好ましい。本発明において好適に用いられる酸発生剤としては、ヨードニウム塩、スルホニウム塩、ホスホニウム塩、ジアゾニウム塩等のオニウム塩が挙げられる。具体的には、特開平７−２０６２９号に記載されている化合物を挙げることができる。特に、スルホン酸イオンを対イオンとするヨードニウム塩、スルホニウム塩、ジアゾニウム塩が好ましい。また、特開平７−２７１０２９号に記載されている、ハロアルキル置換されたｓ−トリアジン類も好ましい。
本発明において特に好適に使用される光又は熱により酸を発生する化合物は、下記一般式（Ｉ）〜(IX)で示される化合物である。
【００３７】
【化６】

【００３８】
式中、Ｒ₁ 、Ｒ₂ 、Ｒ₄ 及びＲ₅ は、同じでも異なっていてもよく、置換基を有していてもよい炭素数２０個以下の炭化水素基を示す。Ｒ₃ はハロゲン原子、置換基を有していてもよい炭素数１０個以下の炭化水素基叉は炭素数１０個以下のアルコキシ基を示す。
Ｒ₆ は置換基を有していてもよい炭素数２５個以下の２価の炭化水素基を示す。ｎは０〜４の整数を示す。
【００３９】
【化７】

【００４０】
Ａｒ₁ 、Ａｒ₂ 、Ａｒ₃ 、Ａｒ₄ は、同じでも異なっていてもよく、置換基を有していてもよい炭素数２０個以下のアリール基を示す。具体的には、フェニル基、トリル基、キシリル基、クメニル基、メシチル基、ドデシルフェニル基、フェニルフェニル基、ナフチル基、アントラセニル基、フルオロフェニル基、クロロフェニル基、ブロモフェニル基、ヨードフェニル基、メトキシフェニル基、ヒドロキシフェニル基、フェノキシフェニル基、ニトロフェニル基、シアノフェニル基、カルボキシフェニル基、アニリノフェニル基、アニリノカルボニルフェニル基、モルホリノフェニル基、フェニルアゾフェニル基、メトキシナフチル基、ヒドロキシナフチル基、ニトロナフチル基、アントラキノニル基等が挙げられる。
【００４１】
Ｒ₇ 、Ｒ₈ 、Ｒ₉ は置換基を有していても良い炭素数１８以下の炭化水素基を示す。
具体的には、メチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、アリル基、ｎ−ブチル基、ｓｅｃ−ブチル基、ｔ−ブチル基、ヘキシル基、シクロヘキシル基、ベンジル基、フェニル基、トリル基、ｔ−ブチルフェニル基、ナフチル基、アントラセニル基、等の炭化水素基、２−メトキシエチル基、フルオロフェニル基、クロロフェニル基、ブロモフェニル基、ヨードフェニル基、メトキシフェニル基、ヒドロキシフェニル基、フェニルチオフェニル基、ヒドロキシナフチル基、メトキシナフチル基、ベンゾイルメチル基、ナフトイルメチル基、等置換基を有する炭化水素基が挙げられる。また、Ｒ₇ とＲ₈ とが互いに結合し環を形成していても良い。
【００４２】
Ｍ^- は、有機化合物または、無機化合物のアニオンであり、例えば、ＳＯ₄ ^2- 、Ｓ₂ Ｏ₃ ^2-、ＨＳＯ₄ ^- 、ＳＯ₃ ^2-、Ｈ₂ ＰＯ₄ ^- 、ＮＯ₃ ^- 、ハロゲンイオン、ＣｌＯ₄ ^- 、ＢＦ₄ ^- 、ＰＦ₆ ^- 、ＳｂＦ₆ ^- 、ＢｉＣｌ₅ ^- 、ＡｓＦ₆ ^- 、ＳｂＣｌ₆ ^- 、ＳｎＣｌ₆ ^- 、Ｒ−ＳＯ₃ ^- 、Ｒ−ＣＯＯ^- 、Ｒ−ＰＯ₄ ^2-などである。但し、Ｒは、水素原子、アルキル基、アリール基又は複素環基を表す。
【００４３】
【化８】

【００４４】
Ｘはハロゲン原子を表わす。Ｙは−ＣＸ₃ 、−ＮＨ₂ 、−ＮＨＲ₁₁、−Ｎ（Ｒ₁₁)₂、−ＯＲ₁₁を表わす。ここでＲ₁₁はアルキル基、置換アルキル基、アリール基、置換アリール基を表わす。またＲ₁₀は−ＣＸ₃ （Ｘはハロゲン）、アルキル基、置換アルキル基、アリール基、置換アリール基、置換アルケニル基を表わす。
一般式化合物（Ｉ）〜（VIII）で表される化合物の内、特に好ましいものを以下に挙げる。
尚、これらの化合物は、例えば特開平２−１０００５４号及び特開平２−１０００５５号、丸善・新実験化学講座１４−Ｉ巻の２・３章（ｐ．４４８）、１４−III 巻の８・１６章（ｐ．１８３８）、同７・１４章（ｐ．１５６４）、J. W. Knapczyk他、J. Am. Chem. Soc. 、９１巻、１４５（１９６９）、A. L. Maycok他、J. Org. Chem. 、３５巻、２５３２（１９７０）、J. V. Crivello他、Polym. Chem. Ed.、１８巻、２６７７（１９８０）、米国特許第２，８０７，６４８号、同４，２４７，４７３号、特開昭５３−１０１３３１号、特公平５−５３１６６号公報等に記載の方法で合成することができる。
【００４５】
【化９】

【００４６】
【化１０】

【００４７】
【化１１】

【００４８】
【化１２】

【００４９】
【化１３】

【００５０】
【化１４】

【００５１】
【化１５】

【００５２】
【化１６】

【００５３】
【化１７】

【００５４】
【化１８】

【００５５】
【化１９】

【００５６】
【化２０】

【００５７】
【化２１】

【００５８】
【化２２】

【００５９】
【化２３】

【００６０】
【化２４】

【００６１】
【化２５】

【００６２】
また、(IX)で示される化合物としては、例えば、若林ら著、Bull. Chem. Soc. Japan, ４２、２９２４（１９６９）記載の化合物、例えば、２−フェニル−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン（以下IX-9と記す）、２−（ｐ−クロルフェニル）−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン、２−（ｐ−トリル）−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン、２−（ｐ−メトキシフェニル）−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン、２−（２′，４′−ジクロルフェニル）−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン、２，４，６−トリス（トリクロルメチル）−Ｓ−トリアジン、２−メチル−４，６−ヒス（トリクロルメチル）−Ｓ−トリアジン、２−ｎ−ノニル−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン、２−（α，α，β−トリクロルエチル）−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン等が挙げられる。
【００６３】
その他、英国特許1388492 号明細書記載の化合物、例えば、２−スチリル−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン、２−（ｐ−メチルスチリル）−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン、２−（ｐ−メトキシスチリル）−４，６−ビス（トリクロルメチル）−Ｓ−トリアジン、２−（ｐ−メトキシスチリル）−４−アミノ−６−トリクロルメチル−Ｓ−トリアジン等、特開昭５３−１３３４２８号記載の化合物、例えば、２−（４−メトキシ−ナフト−１−イル）−４，６−ビス−トリクロルメチル−Ｓ−トリアジン、２−（４−エトキシ−ナフト−１−イル）−４，６−ビス−トリクロルメチル−Ｓ−トリアジン、２−〔４−（２−エトキシエチル）−ナフト−１−イル〕−４，６−ビス−トリクロルメチル−Ｓ−トリアジン、２−（４，７−ジメトキシ−ナフト−１−イル〕−４，６−ビス−トリクロルメチル−Ｓ−トリアジン、２−（アセナフト−５−イル）−４，６−ビス−トリクロルメチル−Ｓ−トリアジン等、独国特許3337024 号明細書記載の化合物、例えば下記の化合物を挙げることができる。
【００６４】
【化２６】

【００６５】
更に特開平５−２８１７２８号記載の化合物、例えば以下に示される化合物等を挙げることができる。
【００６６】
【化２７】

【００６７】
【化２８】

【００６８】
これらの化合物は、感光層全固形分に対し０．０１〜５０重量％、好ましくは０．１〜２５重量％、より好ましくは０．５〜１５重量％の割合で画像記録材料中に添加される。添加量が０．０１重量％未満の場合は、画像が得られない。また添加量が５０重量％を越える場合は、印刷時非画像部に汚れを発生する。
これらの化合物は単独で使用してもよく、また２種以上を組み合わせて使用してもよい。
【００６９】
［（ハ）赤外線吸収剤］
本発明の感光層において使用される赤外線吸収剤は、波長７６０ｎｍから１２００ｎｍの赤外線を有効に吸収する染料または顔料である。好ましくは、波長７６０ｎｍから１２００ｎｍに吸収極大を有する染料または顔料である。
染料としては、市販の染料および文献〔例えば「染料便覧」（有機合成化学協会編集、昭和４５年刊）〕に記載されている如き公知のものが利用できる。具体的には、アゾ染料、金属錯塩アゾ染料、ピラゾロンアゾ染料、ナフトキノン染料、アントラキノン染料、フタロシアニン染料、カルボニウム染料、キノンイミン染料、メチン染料、シアニン染料、スクワリリウム色素、ピリリウム塩、金属チオレート錯体などの染料が挙げられる。
【００７０】
好ましい染料としては例えば特開昭５８−１２５２４６号、特開昭５９−８４３５６号、特開昭５９−２０２８２９号、特開昭６０−７８７８７号等に記載されているシアニン染料、特開昭５８−１７３６９６号、特開昭５８−１８１６９０号、特開昭５８−１９４５９５号等に記載されているメチン染料、特開昭５８−１１２７９３号、特開昭５８−２２４７９３号、特開昭５９−４８１８７号、特開昭５９−７３９９６号、特開昭６０−５２９４０号、特開昭６０−６３７４４号等に記載されているナフトキノン染料、特開昭５８−１１２７９２号等に記載されているスクワリリウム色素、英国特許４３４，８７５号記載のシアニン染料等を挙げることができる。
【００７１】
また、米国特許第５，１５６，９３８号記載の近赤外吸収増感剤も好適に用いられ、また、米国特許第３，８８１，９２４号記載の置換されたアリールベンゾ（チオ）ピリリウム塩、特開昭５７−１４２６４５号（米国特許第４，３２７，１６９号）記載のトリメチンチアピリリウム塩、特開昭５８−１８１０５１号、同５８−２２０１４３号、同５９−４１３６３号、同５９−８４２４８号、同５９−８４２４９号、同５９−１４６０６３号、同５９−１４６０６１号に記載されているピリリウム系化合物、特開昭５９−２１６１４６号記載のシアニン色素、米国特許第４，２８３，４７５号に記載のペンタメチンチオピリリウム塩等や特公平５−１３５１４号、同５−１９７０２号公報に開示されているピリリウム化合物も好ましく用いられる。
【００７２】
また、染料として好ましい別の例として米国特許第４，７５６，９９３号明細書中に式（Ｉ）、（II）として記載されている近赤外吸収染料を挙げることができる。
市販の染料の例としては、日本感光色素社製 ＮＫ２０１４、ＮＫ３５５５、ＮＫＸ１１４、ＮＫ２５４５、ＮＫ３５０８、ＮＫ３５０９等、三井東圧染料社製 ＳＩＲ１２８、ＳＩＲ１３０、ＳＩＲ１３２、ＳＩＲ１０３、ＳＩＲ１５２、ＫＩＲ１０３等、日本化薬社製 ＩＲＧ０２２、ＩＲＧ００２、ＩＲＧ００３等、Ｇｌｅｎｄａｌ社製 Ｃｙａｓｏｒｂ ＩＲ９９等、Ｅｐｏｌｉｎｅ社製ＥｐｏｌｉｇｈｔIV６２Ｂ、ＥｐｏｌｉｇｈｔIII １７８、ＥｐｏｌｉｇｈｔIII １２５、ＥｐｏｌｉｇｈｔIII １３０、ＥｐｏｌｉｇｈｔＶ７２、ＥｐｏｌｉｇｈｔＶ９９、ＥｐｏｌｉｇｈｔIII １１７、ＥｐｏｌｉｇｈｔIII １８９、ＥｐｏｌｉｇｈｔIII ５７、ＥｐｏｌｉｇｈｔIV６２Ａ、ＥｐｏｌｉｇｈｔIV１０１、ＥｐｏｌｉｇｈｔIII １８４、ＥｐｏｌｉｇｈｔIII １９２、ＥｐｏｌｉｇｈｔIV６７、ＥｐｏｌｉｇｈｔＶ６３等が挙げられる。
これらの染料のうち特に好ましいものとしては、シアニン色素、スクワリリウム色素、ピリリウム塩、ニッケルチオレート錯体が挙げられる。
【００７３】
本発明において使用される顔料としては、市販の顔料およびカラーインデックス（Ｃ．Ｉ．）便覧、「最新顔料便覧」（日本顔料技術協会編、１９７７年刊）、「最新顔料応用技術」（ＣＭＣ出版、１９８６年刊）、「印刷インキ技術」ＣＭＣ出版、１９８４年刊）に記載されている顔料が利用できる。
顔料の種類としては、黒色顔料、黄色顔料、オレンジ色顔料、褐色顔料、赤色顔料、紫色顔料、青色顔料、緑色顔料、蛍光顔料、金属粉顔料、その他、ポリマー結合色素が挙げられる。具体的には、不溶性アゾ顔料、アゾレーキ顔料、縮合アゾ顔料、キレートアゾ顔料、フタロシアニン系顔料、アントラキノン系顔料、ペリレンおよびペリノン系顔料、チオインジゴ系顔料、キナクリドン系顔料、ジオキサジン系顔料、イソインドリノン系顔料、キノフタロン系顔料、染付けレーキ顔料、アジン顔料、ニトロソ顔料、ニトロ顔料、天然顔料、蛍光顔料、無機顔料、カーボンブラック等が使用できる。これらの顔料のうち好ましいものはカーボンブラックである。
【００７４】
これら顔料は表面処理をせずに用いてもよく、表面処理を施して用いてもよい。表面処理の方法には樹脂やワックスを表面コートする方法、界面活性剤を付着させる方法、反応性物質（例えば、シランカップリング剤やエポキシ化合物、ポリイソシアネート等）を顔料表面に結合させる方法等が考えられる。上記の表面処理方法は、「金属石鹸の性質と応用」（幸書房）、「印刷インキ技術」（ＣＭＣ出版、１９８４年刊）および「最新顔料応用技術」（ＣＭＣ出版、１９８６年刊）に記載されている。
顔料の粒径は０．０１μｍ〜１０μｍの範囲にあることが好ましく、０．０５μｍ〜１μｍの範囲にあることがさらに好ましく、特に０．１μｍ〜１μｍの範囲にあることが好ましい。顔料の粒径が０．０１μｍ未満では分散物の感光層塗布液中での安定性の点で好ましくなく、また、１０μｍを越えると画像記録層の均一性の点で好ましくない。
【００７５】
顔料を分散する方法としては、インク製造やトナー製造等に用いられる公知の分散技術が使用できる。分散機としては、超音波分散器、サンドミル、アトライター、パールミル、スーパーミル、ボールミル、インペラー、デスパーザー、ＫＤミル、コロイドミル、ダイナトロン、３本ロールミル、加圧ニーダー等が挙げられる。詳細は、「最新顔料応用技術」（ＣＭＣ出版、１９８６年刊）に記載がある。
これらの染料もしくは顔料は、感光層全固形分に対し０．０１〜５０重量％、好ましくは０．１〜１０重量％、染料の場合特に好ましくは０．５〜１０重量％、顔料の場合特に好ましくは１．０〜１０重量％の割合で画像記録材料中に添加することができる。顔料もしくは染料の添加量が０．０１重量％未満であると感度が低くなり、また５０重量％を越えると印刷時非画像部に汚れが発生し易くなる。
これらの染料もしくは顔料は他の成分と同一の層に添加してもよいし、別の層を設けそこへ添加してもよい。
【００７６】
本発明の感光層には、前記（イ）〜（ハ）の３つの成分が必須であるが、必要に応じてこれら以外に先に述べたように、（Ｂ）アルカリ可溶性基を有する高分子化合物を添加することが画像部の強度向上の観点から好ましい。この化合物についての詳細を以下に述べる。
【００７７】
［（Ｂ）アルカリ可溶性基を有する高分子化合物］
本発明において必須成分とともに使用しうるアルカリ可溶性基を有する高分子化合物（以下、適宜、アルカリ可溶性高分子化合物と称する）とは、アルカリ可溶性基を分子内に含む樹脂を指し、例えば、ノボラック樹脂、レゾール樹脂、アセトン−ピロガロール樹脂、ポリヒドロキシスチレン類、ヒドロキシスチレン−Ｎ−置換マレイミド共重合体、ヒドロキシスチレン−無水マレイン酸共重合体、アルカリ可溶性基を有するアクリル系共重合体またはウレタン型重合体であって、アクリル酸等の酸性基を有する構成単位を１モル％以上反応させた高分子化合物、などが挙げられる。ここで、アルカリ可溶性基としてはカルボキシル基、フェノール性水酸基、スルホン酸基、ホスホン酸基、イミド基などが挙げられる。
【００７８】
本発明において使用しうるノボラック樹脂は、フェノール類とアルデヒド類を酸性条件下で縮合させた樹脂である。好ましいノボラック樹脂としては、例えばフェノールとホルムアルデヒドから得られるノボラック樹脂、ｍ−クレゾールとホルムアルデヒドから得られるノボラック樹脂、ｐ−クレゾールとホルムアルデヒドから得られるノボラック樹脂、ｏ−クレゾールとホルムアルデヒドから得られるノボラック樹脂、オクチルフェノールとホルムアルデヒドから得られるノボラック樹脂、ｍ−／ｐ−混合クレゾールとホルムアルデヒドから得られるノボラック樹脂、フェノール／クレゾール（ｍ−，ｐ−，ｏ−またはｍ−／ｐ−，ｍ−／ｏ−，ｏ−／ｐ−混合のいずれでもよい）の混合物とホルムアルデヒドから得られるノボラック樹脂などが挙げられる。
これらのノボラック樹脂は、重量平均分子量が８００〜２００，０００で数平均分子量が４００〜６０，０００のものが好ましい。
本発明において、これらのノボラック樹脂は全感光層固形分中、好ましくは５〜９０重量％、さらに好ましくは１０〜８５重量％、特に好ましくは２０〜８０重量％の添加量で用いられる。ノボラック樹脂の添加量が５重量％未満であると感光層の耐久性が悪化し、また、９０重量％を越えると感度、耐久性の両面で好ましくない。
【００７９】
本発明において使用しうるレゾール樹脂は、フェノール類とアルデヒド類を塩基性条件下で縮合させた樹脂である。好ましいレゾール樹脂としては、例えばフェノールとホルムアルデヒドから得られるレゾール樹脂、ｍ−クレゾールとホルムアルデヒドから得られるレゾール樹脂、ビスフェノールＡとホルムアルデヒドから得られるレゾール樹脂、４，４’−ビスフェノールとホルムアルデヒドから得られるレゾール樹脂等が挙げられる。
これらのレゾール樹脂は、重量平均分子量が５００〜１０0,０００で数平均分子量が２００〜５0,０００のものが好ましい。
本発明において、これらのレゾール樹脂は全感光層固形分中、好ましくは５〜８０重量％、さらに好ましくは１０〜７５重量％、特に好ましくは２０〜７０重量％の添加量で用いられる。レゾール樹脂の添加量が５重量％未満であると記録層の耐久性が悪化し、また、８０重量％を越えると保存時の安定性の点で好ましくない。
【００８０】
本発明において使用されうるヒドロキシスチレン系ポリマーの例としては、ポリ−ｐ−ヒドロキシスチレン、ポリ−ｍ−ヒドロキシスチレン、ｐ−ヒドロキシスチレン−Ｎ−置換マレイミド共重合体、ｐ−ヒドロキシスチレン−無水マレイン酸共重合体などが挙げられる。このようなヒドロキシスチレン系ポリマーを用いる場合には重量平均分子量が２，０００〜５００，０００、好ましくは４，０００〜３００，０００のものが好ましい。
【００８１】
アルカリ可溶性基を有するアクリル系共重合体の例としては、メタクリル酸−アリルメタクリレート共重合体、メタクリル酸−ベンジルメタクリレート共重合体、メタクリル酸−ヒドロキシエチルメタクリレート共重合体、ポリ（ヒドロキシフェニルメタクリルアミド）、ポリ（ヒドロキシフェニルカルボニルオキシエチルアクリレート）、ポリ（２、４−ジヒドロキシフェニルカルボニルオキシエチルアクリレート）、等が挙げられる。これらのアクリル系樹脂は、カルボキシル基やヒドロキシフェニル基等の様な酸性基を分子内に有する構成単位であり、例えば、（メタ）アクリル酸、ヒドロキシスチレン、またヒドロキシフェニル（メタ）アクリルアミド等を全構成単位の１モル％以上反応させた樹脂であって、重量平均分子量が２，０００〜５００，０００、好ましくは4,０００〜３００，０００のものが好ましい。
【００８２】
アルカリ可溶性基を有するウレタン型重合体の例としては、ジフェニルメタンジイソシアネートとヘキサメチレンジイソシアネート、テトラエチレングリコール、２、２−ビス（ヒドロキシメチル）プロピオン酸を反応させて得られる樹脂、などが挙げられる。このウレタン型重合体も、カルボキシル基やフドロキシフェニル基等の如き酸性基を分子内に有する構成単位を１モル％以上反応させた樹脂であることが好ましい。
これらのアルカリ可溶性高分子化合物のうちノボラック樹脂は版の耐久性の点で好ましく、一方、ヒドロキシスチレン系ポリマー及びアルカリ可溶性基を有するアクリル系共重合体は現像性の点で好ましい。
本発明で必須成分とともに使用されるアルカリ可溶性高分子化合物は単独で用いても混合して用いてもよい。これらアルカリ可溶性高分子化合物の添加量は、感光層全固形分に対し好ましくは２０〜９５重量％、さらに好ましくは４０〜９０重量％の割合で画像記録材料中に添加される。添加量が２０重量％未満の場合は、画像形成した際、画像部の強度の向上効果が不充分である。また添加量が９５重量％を超える場合は、画像形成されない。
【００８３】
［その他の成分］
本発明に係る感光層には、前記（イ）〜（ハ）の必須成分や（Ｂ）高分子化合物以外にも、必要に応じて種々の化合物を添加してもよい。
例えば、可視光域に大きな吸収を持つ染料を画像の着色剤として使用することができる。
具体的には、オイルイエロー＃１０１、オイルイエロー＃１０３、オイルピンク＃３１２、オイルグリーンＢＧ、オイルブルーＢＯＳ、オイルブルー＃６０３、オイルブラックＢＹ、オイルブラックＢＳ、オイルブラックＴ−５０５（以上オリエント化学工業（株）製）、ビクトリアピュアブルー、クリスタルバイオレット（ＣＩ４２５５５）、メチルバイオレット（ＣＩ４２５３５）、エチルバイオレット、ローダミンＢ（ＣＩ１４５１７０Ｂ）、マラカイトグリーン（ＣＩ４２０００）、メチレンブルー（ＣＩ５２０１５）など、あるいは特開昭６２−２９３２４７号公報に記載されている染料を挙げることができる。
【００８４】
これらの染料は、画像形成後、画像部と非画像部の区別がつきやすいので、添加する方が好ましい。尚、添加量は、感光層全固形分に対し、０．０１〜１０重量％の割合である。
また、本発明における感光層中には、現像条件に対する処理の安定性を広げるため、特開昭６２−２５１７４０号公報や特開平３−２０８５１４号公報に記載されているような非イオン界面活性剤、特開昭５９−１２１０４４号公報、特開平４−１３１４９号公報に記載されているような両性界面活性剤を添加することができる。
非イオン界面活性剤の具体例としては、ソルビタントリステアレート、ソルビタンモノパルミテート、ソルビタントリオレート、ステアリン酸モノグリセリド、ポリオキシエチレンノニルフェニルエーテル等が挙げられる。
両性界面活性剤の具体例としては、アルキルジ（アミノエチル）グリシン、アルキルポリアミノエチルグリシン塩酸塩、２−アルキル−Ｎ−カルボキシエチル−Ｎ−ヒドロキシエチルイミダゾリニウムベタインやＮ−テトラデシル−Ｎ，Ｎ−ベタイン型（例えば、商品名アモーゲンＫ、第一工業（株）製）等が挙げられる。
上記非イオン界面活性剤および両性界面活性剤の感光層中に占める割合は、０．０５〜１５重量％が好ましく、より好ましくは０．１〜５重量％である。
【００８５】
更に本発明の感光層中には必要に応じ、塗膜の柔軟性等を付与するために可塑剤を加えることができる。例えば、ポリエチレングリコール、クエン酸トリブチル、フタル酸ジエチル、フタル酸ジブチル、フタル酸ジヘキシル、フタル酸ジオクチル、リン酸トリクレジル、リン酸トリブチル、リン酸トリオクチル、オレイン酸テトラヒドロフルフリル等が用いられる。
本発明における感光層中には、塗布性を良化するための界面活性剤、例えば特開昭６２−１７０９５０号公報に記載されているようなフッ素系界面活性剤を添加することができる。好ましい添加量は、感光層の固形分中０．０１〜１重量％、さらに好ましくは０．０５〜０．５重量％である。
【００８６】
本発明の感光層は、通常上記各成分を溶媒に溶かして、支持体上に塗設する。ここで使用する溶媒としては、エチレンジクロライド、シクロヘキサノン、メチルエチルケトン、メタノール、エタノール、プロパノール、エチレングリコールモノメチルエーテル、１−メトキシ−２−プロパノール、２−メトキシエチルアセテート、１−メトキシ−２−プロピルアセテート、ジメトキシエタン、乳酸メチル、乳酸エチル、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ，Ｎ−ジメチルホルムアミド、テトラメチルウレア、Ｎ−メチルピロリドン、ジメチルスルホキシド、スルホラン、γ−ブチルラクトン、トルエン、水等を挙げることができるが、これらに限定されるものではない。これらの溶媒は単独あるいは混合して使用される。溶媒中の上記成分（添加剤を含む全固形分）の濃度は、好ましくは１〜５０重量％である。また塗布、乾燥後に得られる支持体上の塗布量（固形分）は、用途によって異なるが、平版印刷用版材についていえば一般的に０．５〜５．０ｇ／ｍ² が好ましい。塗布する方法としては、種々の方法を用いることができるが、例えば、バーコーター塗布、回転塗布、スプレー塗布、カーテン塗布、ディップ塗布、エアーナイフ塗布、ブレード塗布、ロール塗布等を挙げることができる。塗布量が少なくなるにつれて、見かけの感度は大になるが、画像記録膜の皮膜特性は低下する。
【００８７】
［支持体］
本発明に使用される支持体としては、寸度的に安定な板状物であり、例えば、紙、プラスチック（例えば、ポリエチレン、ポリプロピレン、ポリスチレン等）がラミネートされた紙、金属板（例えば、アルミニウム、亜鉛、銅等）、プラスチックフィルム（例えば、二酢酸セルロース、三酢酸セルロース、プロピオン酸セルロース、酪酸セルロース、酢酸酪酸セルロース、硝酸セルロース、ポリエチレンテレフタレート、ポリエチレン、ポリスチレン、ポリプロピレン、ポリカーボネート、ポリビニルアセタール等）、上記のごとき金属がラミネート、もしくは蒸着された紙、もしくはプラスチックフィルム等が含まれる。
【００８８】
本発明の支持体としては、ポリエステルフィルム又はアルミニウム板が好ましく、その中でも寸法安定性がよく、比較的安価であるアルミニウム板は特に好ましい。好適なアルミニウム板は、純アルミニウム板およびアルミニウムを主成分とし、微量の異元素を含む合金板であり、更にアルミニウムがラミネートもしくは蒸着されたプラスチックフィルムでもよい。アルミニウム合金に含まれる異元素には、ケイ素、鉄、マンガン、銅、マグネシウム、クロム、亜鉛、ビスマス、ニッケル、チタンなどがある。合金中の異元素の含有量は高々１０重量％以下である。本発明において特に好適なアルミニウムは、純アルミニウムであるが、完全に純粋なアルミニウムは精錬技術上製造が困難であるので、僅かに異元素を含有するものでもよい。このように本発明に適用されるアルミニウム板は、その組成が特定されるものではなく、従来より公知公用の素材のアルミニウム板を適宜に利用することができる。本発明で用いられるアルミニウム板の厚みはおよそ０．１ｍｍ〜０．６ｍｍ程度、好ましくは０．１５ｍｍ〜０．４ｍｍ、特に好ましくは０．２ｍｍ〜０．３ｍｍである。
【００８９】
アルミニウム板を粗面化するに先立ち、所望により、表面の圧延油を除去するための例えば界面活性剤、有機溶剤またはアルカリ性水溶液などによる脱脂処理が行われる。
アルミニウム板の表面の粗面化処理は、種々の方法により行われるが、例えば、機械的に粗面化する方法、電気化学的に表面を溶解粗面化する方法および化学的に表面を選択溶解させる方法により行われる。機械的方法としては、ボール研磨法、ブラシ研磨法、ブラスト研磨法、バフ研磨法などの公知の方法を用いることができる。また、電気化学的な粗面化法としては塩酸または硝酸電解液中で交流または直流により行う方法がある。また、特開昭５４−６３９０２号に開示されているように両者を組み合わせた方法も利用することができる。
【００９０】
この様に粗面化されたアルミニウム板は、必要に応じてアルカリエッチング処理および中和処理された後、所望により表面の保水性や耐摩耗性を高めるために陽極酸化処理が施される。アルミニウム板の陽極酸化処理に用いられる電解質としては、多孔質酸化皮膜を形成する種々の電解質の使用が可能で、一般的には硫酸、リン酸、蓚酸、クロム酸あるいはそれらの混酸が用いられる。それらの電解質の濃度は電解質の種類によって適宜決められる。
陽極酸化の処理条件は用いる電解質により種々変わるので一概に特定し得ないが、一般的には電解質の濃度が１〜８０重量％溶液、液温は５〜７０℃、電流密度５〜６０Ａ／ｄｍ² 、電圧１〜１００Ｖ、電解時間１０秒〜５分の範囲であれば適当である。
【００９１】
陽極酸化皮膜の量は1.０ｇ／ｍ² より少ないと耐刷性が不十分であったり、平版印刷版の非画像部に傷が付き易くなって、印刷時に傷の部分にインキが付着するいわゆる「傷汚れ」が生じ易くなる。
陽極酸化処理を施された後、アルミニウム表面は必要により親水化処理が施される。本発明に使用される親水化処理としては、米国特許第２，７１４，０６６号、同第３，１８１，４６１号、第３，２８０，７３４号および第３，９０２，７３４号に開示されているようなアルカリ金属シリケート（例えばケイ酸ナトリウム水溶液）法がある。この方法においては、支持体がケイ酸ナトリウム水溶液で浸漬処理されるかまたは電解処理される。他に特公昭３６−２２０６３号公報に開示されているフッ化ジルコン酸カリウムおよび米国特許第３，２７６，８６８号、同第４，１５３，４６１号、同第４，６８９，２７２号に開示されているようなポリビニルホスホン酸で処理する方法などが用いられる。
【００９２】
本発明のネガ型画像記録材料は、必要に応じて支持体上に下塗層を設けることができる。下塗層成分としては種々の有機化合物が用いられ、例えば、カルボキシメチルセルロース、デキストリン、アラビアガム、２−アミノエチルホスホン酸などのアミノ基を有するホスホン酸類、置換基を有してもよいフェニルホスホン酸、ナフチルホスホン酸、アルキルホスホン酸、グリセロホスホン酸、メチレンジホスホン酸およびエチレンジホスホン酸などの有機ホスホン酸、置換基を有してもよいフェニルリン酸、ナフチルリン酸、アルキルリン酸およびグリセロリン酸などの有機リン酸、置換基を有してもよいフェニルホスフィン酸、ナフチルホスフィン酸、アルキルホスフィン酸およびグリセロホスフィン酸などの有機ホスフィン酸、グリシンやβ−アラニンなどのアミノ酸類、およびトリエタノールアミンの塩酸塩などのヒドロキシ基を有するアミンの塩酸塩等から選ばれるが、２種以上混合して用いてもよい。有機下塗層の被覆量は、２〜２００ｍｇ／ｍ² が適当である。
【００９３】
以上のようにして、本発明の画像記録材料を用いた平版印刷用版材を作成することができる。この平版印刷用版材は、波長７６０ｎｍから１２００ｎｍの赤外線を放射する固体レーザ及び半導体レーザにより画像露光される。本発明においては、レーザ照射後すぐに現像処理を行っても良いが、レーザ照射工程と現像工程の間に加熱処理を行うことが好ましい。加熱処理の条件は、８０℃〜１５０℃の範囲内で１０秒〜５分間行うことが好ましい。この加熱処理により、レーザ照射時、記録に必要なレーザエネルギーを減少させることができる。
【００９４】
必要に応じて加熱処理を行った後、本発明の画像記録材料はアルカリ性水溶液にて現像される。
本発明の画像記録材料の現像液および補充液としては従来より知られているアルカリ剤水溶液が使用できる。この現像液および補充液に用いられるアルカリ剤としは、例えば、ケイ酸ナトリウム、ケイ酸カリウム、第３リン酸ナトリウム、第３リン酸カリウム、第３リン酸アンモニウム、第２リン酸ナトリウム、第２リン酸カリウム、第２リン酸アンモニウム、炭酸ナトリウム、炭酸カリウム、炭酸アンモニウム、炭酸水素ナトリウム、炭酸水素カリウム、炭酸水素アンモニウム、ほう酸ナトリウム、ほう酸カリウム、ほう酸アンモニウム、水酸化ナトリウム、水酸化アンモニウム、水酸化カリウムおよび水酸化リチウムなどの無機アルカリ塩が挙げられる。また、モノメチルアミン、ジメチルアミン、トリメチルアミン、モノエチルアミン、ジエチルアミン、トリエチルアミン、モノイソプロピルアミン、ジイソプロピルアミン、トリイソプロピルアミン、ｎ−ブチルアミン、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、モノイソプロパノールアミン、ジイソプロパノールアミン、エチレンイミン、エチレンジアミン、ピリジンなどの有機アルカリ剤も用いられる。
【００９５】
これらのアルカリ剤は単独もしくは２種以上を組み合わせて用いられる。
これらのアルカリ剤の中で特に好ましい現像液は、ケイ酸ナトリウム、ケイ酸カリウム等のケイ酸塩水溶液である。その理由はケイ酸塩の成分である酸化珪素ＳｉＯ₂ とアルカリ金属酸化物Ｍ₂ Ｏの比率と濃度によって現像性の調節が可能となるためであり、例えば、特開昭５４−６２００４号公報、特公昭５７−７４２７号に記載されているようなアルカリ金属ケイ酸塩が有効に用いられる。
【００９６】
更に自動現像機を用いて現像する場合には、現像液よりもアルカリ強度の高い水溶液（補充液）を現像液に加えることによって、長時間現像タンク中の現像液を交換する事なく、多量の平版印刷用版材を処理できることが知られている。本発明においてもこの補充方式が好ましく適用される。
現像液および補充液には現像性の促進や抑制、現像カスの分散および印刷版画像部の親インキ性を高める目的で必要に応じて種々の界面活性剤や有機溶剤を添加できる。好ましい界面活性剤としては、アニオン系、カチオン系、ノニオン系および両性界面活性剤が挙げられる。
更に現像液および補充液には必要に応じて、ハイドロキノン、レゾルシン、亜硫酸、亜硫酸水素酸などの無機酸のナトリウム塩、カリウム塩等の還元剤、更に有機カルボン酸、消泡剤、硬水軟化剤を加えることもできる。
上記現像液および補充液を用いて現像処理された印刷版は水洗水、界面活性剤等を含有するリンス液、アラビアガムや澱粉誘導体を含む不感脂化液で後処理される。本発明の画像記録材料を印刷用版材として使用する場合の後処理としては、これらの処理を種々組み合わせて用いることができる。
【００９７】
近年、製版・印刷業界では製版作業の合理化および標準化のため、印刷用版材用の自動現像機が広く用いられている。この自動現像機は、一般に現像部と後処理部からなり、印刷用版材を搬送する装置と各処理液槽およびスプレー装置からなり、露光済みの印刷版を水平に搬送しながら、ポンプで汲み上げた各処理液をスプレーノズルから吹き付けて現像処理するものである。また、最近は処理液が満たされた処理液槽中に液中ガイドロールなどによって印刷用版材を浸漬搬送させて処理する方法も知られている。このような自動処理においては、各処理液に処理量や稼働時間等に応じて補充液を補充しながら処理することができる。
また、実質的に未使用の処理液で処理するいわゆる使い捨て処理方式も適用できる。
【００９８】
以上のようにして得られた平版印刷版は所望により不感脂化ガムを塗布したのち、印刷工程に供することができるが、より一層の高耐刷力の平版印刷版としたい場合にはバーニング処理が施される。
平版印刷版をバーニングする場合には、バーニング前に特公昭６１−２５１８号、同５５−２８０６２号、特開昭６２−３１８５９号、同６１−１５９６５５号の各公報に記載されているような整面液で処理することが好ましい。
その方法としては、該整面液を浸み込ませたスポンジや脱脂綿にて、平版印刷版上に塗布するか、整面液を満たしたバット中に印刷版を浸漬して塗布する方法や、自動コーターによる塗布などが適用される。また、塗布した後でスクィージ、あるいは、スクィージローラーで、その塗布量を均一にすることは、より好ましい結果を与える。
【００９９】
整面液の塗布量は一般に０．０３〜０．８ｇ／ｍ² （乾燥重量）が適当である。
整面液が塗布された平版印刷版は必要であれば乾燥された後、バーニングプロセッサー（たとえば富士写真フイルム（株）より販売されているバーニングプロセッサー：ＢＰ−１３００）などで高温に加熱される。この場合の加熱温度及び時間は、画像を形成している成分の種類にもよるが、１８０〜３００℃の範囲で１〜２０分の範囲が好ましい。
バーニング処理された平版印刷版は、必要に応じて適宜、水洗、ガム引きなどの従来より行なわれている処理を施こすことができるが、水溶性高分子化合物等を含有する整面液が使用された場合にはガム引きなどのいわゆる不感脂化処理を省略することができる。
この様な処理によって得られた平版印刷版はオフセット印刷機等にかけられ、多数枚の印刷に用いられる。
【０１００】
【実施例】
以下、実施例により、本発明を詳細に説明するが、本発明はこれらに限定されるものではない。
［本発明の酸により架橋する架橋剤〔ＨＭ−１〕の合成］
１−〔α−メチル−α−（４−ヒドロキシフェニル）エチル〕−４−〔α，α−ビス（４−ヒドロキシフェニル）エチル〕ベンゼン２０ｇ（本州化学工業（株）製Ｔｒｉｓｐ−ＰＡ）を１０％水酸化カリウム水溶液に加え、撹拌、溶解した。次にこの溶液を撹拌しながら、３７％ホルマリン水溶液６０ｍｌを室温下で１時間かけて徐々に加えた。さらに室温下で６時間撹拌した後、希硫酸水溶液に投入した。析出物をろ過し、十分水洗した後、メタノール３０ｍｌより再結晶することにより、下記構造のヒドロキシメチル基を有するフェノール誘導体〔ＨＭ−１〕の白色粉末２０ｇを得た。純度は９２％であった（液体クロマトグラフィー法）。
【０１０１】
【化２９】

【０１０２】
［本発明の酸により架橋する架橋剤〔ＭＭ−１〕の合成］
上記合成例で得られたヒドロキシメチル基を有するフェノール誘導体〔ＨＭ−１〕２０ｇを１リットルのメタノールに加え、加熱撹拌し、溶解した。次に、この溶液に濃硫酸１ｍｌを加え、１２時間加熱還流した。反応終了後、反応液を冷却し、炭酸カリウム２ｇを加えた。この混合物を十分濃縮した後、酢酸エチル３００ｍｌを加えた。この溶液を水洗した後、濃縮乾固させることにより、下記構造のメトキシメチル基を有するフェノール誘導体〔ＭＭ−１〕の白色固体２２ｇを得た。純度は９０％であった（液体クロマトグラフィー法）。
【０１０３】
【化３０】

【０１０４】
さらに、同様にして以下に示すフェノール誘導体を合成した。
【０１０５】
【化３１】

【０１０６】
【化３２】

【０１０７】
【化３３】

【０１０８】
［実施例１〜２６、比較例１〜２６］
厚さ０．３０ｍｍのアルミニウム板（材質１０５０）をトリクロロエチレン洗浄して脱脂した後、ナイロンブラシと４００メッシュのパミストン−水懸濁液を用いて表面を砂目立てし、よく水で洗浄した。この板を４５℃の２５％水酸化ナトリウム水溶液に９秒間浸漬してエッチングを行い水洗後、更に２％ＨＮＯ₃ に２０秒間浸漬して水洗した。この時の砂目立て表面のエッチング量は約３ｇ／ｍ² であった。次にこの板を７％Ｈ₂ ＳＯ₄ を電解液として電流密度１５Ａ／ｄｍ² で３ｇ／ｍ² の直流陽極酸化皮膜を設けた後、水洗乾燥した。次にこのアルミニウム板に下記下塗り液を塗布し、８０℃で３０秒間乾燥した。乾燥後の被覆量は１０ｍｇ／ｍ² であった。
（下塗り液）
β−アラニン ０．１ｇ
フェニルホスホン酸 ０．０５ｇ
メタノール ４０ｇ
純水 ６０ｇ
【０１０９】
次に、下記の処方において、（イ）バインダー、（ロ）酸により架橋する架橋剤、（ハ）光又は熱により酸を発生する化合物の種類を変えて、感光層溶液を調整した。この溶液をそれぞれ、上記の下塗り済みのアルミニウム板に塗布し、１００℃で１分間乾燥してＰ−１からＰ−２６の版材を得た。表１に各プレートに使用した化合物を示す。乾燥後の重量は1.７ｇ／ｍ² であった。
［感光層塗布液］
（イ）酸により架橋する架橋剤（表１に示す） ０．７ｇ
（ロ）光又は熱により酸を発生する化合物（表１に示す） ０．２ｇ
（ハ）赤外線吸収剤 ０．１５ｇ
（ＮＫ−３５０８：商品名、日本感光色素研究所（株）製）
（Ｂ）バインダー（表１に示す） １．５ｇ
添加剤
ビクトリアピュアブルー ＢＯ(C.I.44040) ０．０５ｇ
フッ素系界面活性剤 ０．０６ｇ
（メガファックＦ−１７７：商品名）、大日本インキ化学工業（株）製）
溶剤
メチルエチルケトン １５ｇ
１−メトキシ−２−プロパノール ５ｇ
メチルアルコール ７ｇ
【０１１０】
【表１】

【０１１１】
表１に示すバインダーは、以下の通りである。
（Ｂ−１）フェノールとホルムアルデヒドから得られるノボラック樹脂
重量平均分子量１００００
（Ｂ−２）クレゾールとホルムアルデヒドから得られるノボラック樹脂
メタ／パラ比＝８／２、重量平均分子量５８００
（Ｂ−３）ポリ-p- ヒドロキシスチレン
重量平均分子量８０００
【０１１２】
前記の処方の感光層を塗設したプレート（Ｐ−１からＰ−２６）の上に下記組成からなる水溶性オーバーコート層を乾燥塗布重量が２．５ｇ／ｍ² となるように塗布し、１００℃／３分間乾燥させた。
比較例は、このオーバーコート層を塗設せずＰ−１からＰ−２６をそのまま用いた。
【０１１３】
［オーバーコート層塗布液の処方］
（１）雲母分散液の調整
水１８４ｇに合成雲母（ソマシフＭＥ−１００：商品名、コープケミカル（株）社製、アスペクト比：１０００以上）の１６ｇを添加し、ホモジナイザーを用いて平均粒径（レーザ散乱法）３μｍになる迄分散し、雲母分散液を得た。
【０１１４】
（２）オーバーコート層塗布液の調整
調整済の雲母分散液６ｇに水１００ｇを加え、ポリビニルアルコール（ＰＶＡ−１２４ クラレ（株）製）８重量％水溶液１２ｇを加えよく攪拌した後、２−エチルヘキシルスルホコハク酸ソーダ２重量％液を１０ｇ加え、オーバーコート層塗布液を得た。
【０１１５】
得られたネガ型平版印刷用版材を、波長１０６４ｎｍの赤外線を発する固体レーザのＹＡＧレーザ（出力５００ｍＷ）で露光した。露光後、１２０℃で３０秒間加熱処理した後、富士写真フイルム（株）製現像液、ＤＰ−４（１：８）、リンス液ＦＲ−３（１：７）を仕込んだ自動現像機を通して処理した。その際、画像形成した版面上の最低露光エネルギーを感度とし、作成直後及び４５℃相対湿度７５％の環境下で３日間保存後の感度を測定した。測定結果を表２及び表３に示す。
【０１１６】
【表２】

【０１１７】
【表３】

【０１１８】
表２及び表３より明らかなように、本発明の実施例１〜２６のネガ型画像記録材料を用いた平版印刷用版材はバインダー、架橋剤、酸発生剤の種類に係わらず、高感度であり、高温高湿下の保存時の安定性に優れていることがわかる。一方、比較例１〜２６のネガ型画像記録材料を用いた平版印刷用版材は、特定の架橋剤を用いたものは作成直後の感度に優れているものの、高温高湿条件下に保存したところ、大幅に感度が低下し、その他の試料は同じ条件下で画像を形成しなかった。
【０１１９】
［実施例２７〜５２］
次に、下記の処方において、（Ｂ）バインダー、（イ）酸により架橋する架橋剤、（ロ）光又は熱により酸を発生する化合物の種類を変えて、感光層溶液を調整した。この溶液をそれぞれ、上記の下塗り済みのアルミニウム板に塗布し、１００℃で１分間乾燥してＰ−２７からＰ−５２の版材を得た。表４に各プレートに使用した化合物を示す。乾燥後の重量は1.７ｇ／ｍ² であった。
［感光層塗布液］
（イ）酸により架橋する物質（表４に示す） ０．８ｇ
（ロ）光又は熱により酸を発生する化合物（表４に示す） ０．２ｇ
（ハ）赤外線吸収剤 ０．１５ｇ
（ＮＫ−２０１４：商品名、日本感光色素研究所（株）製）
（Ｂ）バインダー（表４に示す） １．６ｇ
添加剤
ビクトリアピュアブルー ＢＯ(C.I.44040) ０．０５ｇ
フッ素系界面活性剤 ０．０６ｇ
（メガファックＦ−１７７：商品名）、大日本インキ化学工業（株）製）
溶剤
メチルエチルケトン １５ｇ
１−メトキシ−２−プロパノール ５ｇ
メチルアルコール ７ｇ
【０１２０】
【表４】

【０１２１】
前記の処方の感光層を塗設したプレート（Ｐ−２７からＰ−５２）の上に、実施例１〜２６で用いたのと同じオーバーコート層を乾燥塗布重量が２．２ｇ／ｍ² となるように塗布し、１００℃／３分間乾燥させた。
比較例は、このオーバーコート層を塗設せずＰ−２７からＰ−５２をそのまま用いた。
得られたネガ型平版印刷用版材を、波長８４０ｎｍの赤外線を発する半導体レーザ（出力５００ｍＷ）で露光した。露光後、１２０℃で１分間加熱処理した後、富士写真フイルム（株）製現像液、ＤＰ−４（１：８）、リンス液ＦＲ−３（１：７）を仕込んだ自動現像機を通して処理した。各版材の作成直後及び５０℃３日間保存後の感度を測定した結果を表５及び表６に示す。
【０１２２】
【表５】

【０１２３】
【表６】

【０１２４】
表６及び表７より明らかなように、本発明の実施例２７〜５２のネガ型画像記録材料を用いた平版印刷用版材は、用いたバインダー、架橋剤、酸発生剤に係わらず、高感度であり、高温高湿条件下における保存時の安定性に優れていることがわかる。一方、比較例２７〜５２のネガ型画像記録材料を用いた平版印刷用版材は、特定の架橋剤を用いたものは作成直後の感度に優れているものの、高温高湿条件下に保存したところ、大幅に感度が低下し、その他の試料は同じ条件下で画像を形成しなかった。
【０１２５】
［実施例５３〜５８、比較例５３〜５８］
前記の実施例、比較例で用いたネガ型平版印刷版材（Ｐ−４２）を、波長８４０ｎｍの赤外線を発する半導体レーザ（出力５００ｍＷ）で露光した。露光後、加熱温度、加熱時間を変え処理した後、富士写真フイルム（株）製現像液、ＤＰ−４（１：８）、リンス液ＦＲ−３（１：７）を仕込んだ自動現像機を通して処理した。
【０１２６】
【表７】

【０１２７】
表７より明らかなように、実施例５３〜５８（オーバーコート層あり）の記録材料は、加熱温度、加熱時間に係わらず高感度であったが、比較例５３〜５８（オーバーコート層なし）では、３０秒の加熱時間でも感度の低下が見られ、６０秒の加熱時間においては画像が形成されなかったことから、本発明のネガ型画像記録材料を用いた平版印刷用版材は、露光後の加熱処理条件の許容性が優れていることがわかる。
【０１２８】
【発明の効果】
本発明のネガ型平版印刷用版材は、赤外線を放射する固体レーザ及び半導体レーザを用いて記録することにより、コンピューター等のデジタルデータから直接製版可能であり、さらに、感度が高く、高温高湿条件下における保存時の安定性に優れ、露光後の加熱処理条件の許容性が優れている。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a negative image recording material that can be used as a lithographic printing plate, and more particularly to a so-called direct plate-making negative image recording material that can be directly made from a digital signal of a computer or the like using an infrared laser.
[0002]
[Prior art]
Conventionally, plate making directly from computer digital data includes (1) electrophotography, (2) photopolymerization system using blue or green light emitting laser, and (3) salt photosensitivity. There have been proposed ones laminated on a resin, and (4) a silver salt diffusion transfer method.
However, in the case of using the electrophotographic method (1), the image forming process such as charging, exposure and development is complicated, and the apparatus becomes complicated and large. The photopolymerization system (2) is a plate material that is highly sensitive to blue and green light, making it difficult to handle in a bright room. In the methods (3) and (4), since a silver salt is used, processing such as development becomes complicated, and naturally, there is a drawback that silver is contained in the processing waste liquid.
[0003]
On the other hand, the development of lasers in recent years is remarkable. Particularly, solid lasers and semiconductor lasers that emit infrared rays having a wavelength of 760 nm to 1200 nm are easily available with high output and small size. Further, these lasers are very useful as a recording light source when directly making a plate from digital data such as a computer. However, since many photosensitive recording materials useful in practical use have a photosensitive wavelength in the visible light range of 760 nm or less, image recording cannot be performed with these infrared lasers. Therefore, a material that can be recorded with an infrared laser is desired.
As an image recording material that can be recorded by such an infrared laser, there is a recording material composed of an onium salt, a resole resin, a novolak resin, and an infrared absorber, as described in JP-A-7-20629. Japanese Patent Application Laid-Open No. 7-271029 describes a recording material comprising a haloalkyl-substituted s-triazine, a resole resin, a novolac resin, and an infrared absorber.
However, in many plate materials using these image recording materials, practical sensitivity has not yet been achieved, and even if it has been reached, the sensitivity tends to fluctuate after storage under high temperature and high humidity conditions, and further after exposure. There was a problem that the sensitivity easily fluctuated depending on the heat treatment conditions.
[0004]
[Problems to be solved by the invention]
Therefore, the object of the present invention is to enable direct plate-making from digital data such as a computer by recording using a solid-state laser and a semiconductor laser that emits infrared rays, and has high sensitivity and excellent stability during storage. It is an object of the present invention to provide a negative type image recording material having excellent tolerance of heat treatment conditions after exposure.
[0005]
[Means for Solving the Problems]
  As a result of various studies, the present inventor uses a negative image recording material in which a photosensitive layer and an overcoat layer shown below are sequentially provided on a support, thereby providing high sensitivity and excellent storage stability. It has been found that the tolerance of the heat treatment conditions after the exposure is good and the handling property is excellent, and the present invention has been achieved.
  Here, the photosensitive layer contains the following components (A) to (C).
  (A) a crosslinking agent that crosslinks with an acid;
  (B) a compound that generates an acid by light or heat,
  (C) Infrared absorber,
  Also, the overcoat layerFlatIt contains an inorganic stratiform compound.
[0006]
In the negative image recording material of the present invention, the energy of the irradiated infrared laser or the like is converted into heat by (c) an infrared absorber, and (b) a compound that generates an acid by light or heat is decomposed by the heat. As a result, strong acids (for example, sulfonic acid, halogen acid, etc.) are generated. This acid promotes the cross-linking reaction of the substance that is cross-linked by the acid (a), creates an alkali-insoluble substance by cross-linking of the cross-linking substances, and is added as necessary. A cross-linking reaction with a molecular compound, that is, a polymer compound having a substituent capable of reacting with the component (a) in the side chain is promoted to produce an alkali-insoluble substance. In this way, image recording, that is, plate making of a recording material is performed.
However, in the air, a base that traps acid generated during exposure in the photosensitive layer, or water, (base), a compound such as acid or oxygen that hinders the reaction that occurs in the photosensitive layer is suspended. . These floating substances inhibit the crosslinking reaction by heat.
[0007]
Since the overcoat layer of the present invention contains at least an inorganic stratiform compound and a binder, it can effectively inhibit the influence of outside air on the compound in the photosensitive layer and the compound produced by exposure. That is, the overcoat layer is water, base, or acid present in the air that inhibits the mixing of bases that trap the acid generated during exposure in the photosensitive layer or the reaction that occurs in the photosensitive layer. It is provided for the purpose of effectively preventing compounds such as oxygen and oxygen from entering the photosensitive layer by the action of the dispersed layered compound.
Another effect is to prevent the acid generated in the photosensitive layer from diffusing into the air and to improve the tolerance of the heat treatment conditions when curing by post-heating.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail. That is, the negative image recording material of the present invention is characterized in that a photosensitive layer containing a specific negative recording material component and an overcoat layer containing an inorganic layered compound are sequentially provided on a support. is there.
That is, the photosensitive layer contains at least (i) a substance that crosslinks with an acid, (b) a compound that generates an acid by light or heat, and (c) an infrared absorber, and the overcoat layer has an inorganic layer shape. Contains a compound and a suitable binder component.
Next, each will be described in detail.
[0009]
[Overcoat layer]
The overcoat layer, which is the greatest feature of the present invention, is provided in order to inhibit the influence of outside compounds on the compound in the photosensitive layer and the compound produced by exposure to actinic rays. Therefore, it is preferable that the low molecular weight compound existing in the air or the low molecular weight compound generated in the photosensitive layer has low permeability. That is, the overcoat layer is water, base, or acid present in the air that inhibits the mixing of bases that trap the acid generated during exposure in the photosensitive layer or the reaction that occurs in the photosensitive layer. It is preferable that compounds such as oxygen and oxygen can be prevented from being mixed into the photosensitive layer, and that the overcoat layer in the non-image area can be removed before or during development. That is, a film having a low gas permeability or a film forming film is preferable.
[0010]
As described above, the characteristics of the overcoat layer suitable for the negative type image recording material include a film having a low gas permeability without inhibiting the transmission of actinic rays used for exposure, generally infrared laser light, or A film can be formed and the adhesiveness to the recording layer is excellent. As a result of intensive studies, the present inventors have found that an overcoat layer exhibiting excellent performance can be obtained by using an inorganic layered compound having the following physical properties together with a suitable binder.
[0011]
The inorganic layered compound used in the present invention is a thin plate having a thin shape, for example, the general formula A (B, C)._2-5D_FourO_Ten(OH, F, O)₂[However, A is any one of K, Na, and Ca, B and C are any of FeII, FeIII, Mn, Al, Mg, and V, and D is Si or Al. ] Mica group such as natural mica and synthetic mica represented by the general formula 3MgO · 4SiO · H₂Examples include talc, teniolite, montmorillonite, saponite, hectorite, and zirconium phosphate represented by O.
[0012]
In the mica group, examples of natural mica include muscovite, soda mica, phlogopite, biotite and sericite. As the synthetic mica, fluorine phlogopite KMg_Three(AlSi_ThreeO_Ten) F₂, Potassium tetrasilicon mica KMg_2.5Si_FourO_Ten) F₂Non-swellable mica, and Na tetrasilicic mica NaMg_2.5(Si_FourO_Ten) F₂, Na or Li teniolite (Na, Li) Mg₂Li (Si_FourO_Ten) F₂Montmorillonite Na or Li hectorite (Na, Li)_1/8Mg_{twenty five}Li_1/8(Si_FourO_Ten) F₂Swellable mica and the like. Synthetic smectite is also useful.
[0013]
In the present invention, among the inorganic layered compounds described above, fluorine-based swellable mica, which is a synthetic inorganic layered compound, is particularly useful.
That is, this swellable synthetic mica and swellable viscosity minerals such as montmorillonite, saponite, hectorite, bentonite, etc. have a laminated structure composed of unit crystal lattice layers with a thickness of about 10 to 15 mm, Atomic substitution is significantly greater than other viscous minerals. As a result, the lattice layer suffers from a shortage of positive charges, and between the layers to compensate for it, Na⁺, Ca²⁺, Mg²⁺Etc. are adsorbed. The cations present between these layers are called exchangeable cations and exchange with various cations. In particular, the cation between layers is Li⁺, Na⁺In this case, since the ionic radius is small, the bond between the layered crystal lattices is weak and the water swells greatly with water. If shear is applied in this state, it will easily cleave and form a stable sol in water. Bentonite and swellable synthetic mica have a strong tendency and are useful in the present invention, and swellable synthetic mica is particularly preferably used.
[0014]
As the shape of the inorganic layered compound used in the present invention, from the viewpoint of diffusion control, the smaller the thickness, the better. The plane size is large as long as the smoothness of the coated surface and the transmittance of actinic rays are not hindered. Moderate. Accordingly, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.
[0015]
The average major axis of the inorganic stratiform compound used in the present invention is 0.3 to 20 μm, preferably 0.5 to 10 μm, particularly preferably 1 to 5 μm. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. For example, among the inorganic stratiform compounds, the size of the swellable synthetic mica that is a representative compound is 1 to 50 nm in thickness and about 1 to 20 μm in surface size.
[0016]
When the inorganic layered compound particles having such a large aspect ratio are contained in the overcoat layer, the coating film strength is improved and the permeation of oxygen and moisture can be effectively prevented. Even when stored for a long time under high humidity conditions, the storage stability of the lithographic printing plate precursor is not deteriorated due to changes in humidity, and the storage stability is excellent.
[0017]
The amount of the inorganic stratiform compound contained in the overcoat layer is preferably 5/1 to 1/100 by weight with respect to the amount of the binder used in the overcoat layer. If the amount of the inorganic layered compound is less than 1/100 in the weight comparison example, there is no effect of adding the inorganic layered compound, and if it exceeds 5/1, the coating film may be cracked.
Even when a plurality of types of inorganic stratiform compounds are used in combination, the total amount of these inorganic stratiform compounds is preferably the above weight ratio.
[0018]
The binder used in the overcoat layer of the present invention is not particularly limited as long as the dispersibility of the inorganic stratiform compound is good and a uniform film that adheres to the photosensitive layer can be formed. Any water-insoluble polymer can be appropriately selected and used. Specifically, for example, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, partially saponified product of polyvinyl acetate, ethylene-vinyl alcohol copolymer, water-soluble cellulose derivative, gelatin, starch derivative, Arabic Water-soluble polymers such as rubber, and water-insoluble polymers such as polyvinylidene chloride, poly (meth) acrylonitrile, polysulfone, polyvinyl chloride, polyethylene, polycarbonate, polystyrene, polyamide, and cellophane are exemplified. These may be used in combination of two or more as required.
Of these, water-soluble polymers are preferred from the viewpoint of easy removal of the overcoat layer remaining in the non-image area and handling properties during film formation, and water-soluble acrylic resins such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyacrylic acid. Gelatin, gum arabic, and the like are preferable. Among them, polyvinyl alcohol, polyvinyl pyrrolidone, gelatin, gum arabic and the like are further used from the viewpoint that they can be applied using water as a solvent and can be easily removed in the development process. preferable.
[0019]
Specifically, polyvinyl alcohol, polyvinylidene chloride, poly (meth) acrylonitrile, polysulfone, acetyl cellulose, polyvinyl chloride, polyvinyl acetate, ethylene-vinyl alcohol copolymer, polyethylene, polycarbonate, polystyrene, polyethylene, polyamide, cellophane , Acrylic resin, gelatin, gum arabic and the like. These may be used alone or in combination.
More preferred are water-soluble polymers such as polyvinyl alcohol, water-soluble acrylic resin, polyvinyl pyrrolidone, gelatin, gum arabic and the like from the standpoint of removal during development and ease of coating. Even more preferably, polyvinyl alcohol, polyvinyl pyrrolidone, gelatin or gum arabic which can be applied with water as a solvent and can be removed with an aqueous developer is preferable.
[0020]
The polyvinyl alcohol used in the overcoat layer of the present invention may be partially substituted with esters, ethers, and acetals as long as it contains a substantial amount of unsubstituted vinyl alcohol units having the necessary water solubility. good. Similarly, a part may contain other copolymerization components.
Specific examples of polyvinyl alcohol include those that are 71-100% hydrolyzed and have a degree of polymerization in the range of 300-2400. Specifically, Kuraray PVA-105, PVA-110, PVA-117, PVA-117H PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203 , PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA -224E, PVA-405, PVA-420, PVA-613, L-8, etc. Examples of the copolymer include 88-100% hydrolyzed polyvinyl acetate chloroacetate or propionate, polyvinyl formal and polyvinyl acetal, and copolymers thereof.
[0021]
To the overcoat layer using a water-soluble polymer such as polyvinyl alcohol, a known additive such as a surfactant for improving the coating property and a water-soluble plasticizer for improving the physical properties of the film may be added. good. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. Further, a water-soluble (meth) acrylic polymer may be added. Furthermore, an additive may be added to these polymers for adhesion to the photosensitive layer, improvement of stability over time, and the like.
[0022]
The overcoat layer using a water-soluble polymer such as polyvinyl alcohol is usually coated on the photosensitive layer by dissolving the above components in water. As the coating solvent, distilled water is preferably used. As the coating method, an existing method is used similarly to the coating of the photosensitive layer.
The coating amount obtained after applying and drying the overcoat layer is 0.5 to 10 g / m.²Preferably 1-5 g / m²It is.
[0023]
[Photosensitive layer containing components (a) to (c)]
Next, the photosensitive layer of the present invention will be described in detail. The photosensitive layer of the present invention contains the following (a) to (d) as essential components.
(A) Substances that crosslink with acids,
(B) a compound that generates an acid by light or heat,
(C) Infrared absorber.
Each of these components will be described in detail below.
In addition, it is preferable to add (B) a polymer compound having an alkali-soluble group to the photosensitive layer from the viewpoint of improving the film property of the alkali-insoluble substance, that is, the strength of the image area.
[0024]
[(I) Substance that crosslinks with acid]
Examples of the substance that is cross-linked with an acid preferably used in the photosensitive layer of the present invention include (a) two or more hydroxymethyl groups, alkoxymethyl groups, epoxy groups, or vinyl ether groups in the molecule, and these groups are benzene. Examples thereof include a compound bonded to a ring, (b) a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, and (c) an epoxy compound.
(A) Specific examples of the compound having two or more hydroxymethyl group, alkoxymethyl group, epoxy group or vinyl ether group in the molecule and these groups are bonded to the benzene ring include methylolmelamine, resole Resins, epoxidized novolac resins, urea resins and the like can be mentioned. Furthermore, the compounds described in “Crosslinking agent handbook” (Shinzo Yamashita, Tosuke Kaneko, Taiseisha Co., Ltd.) are also preferred. In particular, a phenol derivative having two or more hydroxymethyl groups or alkoxymethyl groups in the molecule is preferable because the strength of the image area when an image is formed is good. Specifically, a resole resin can be mentioned.
[0025]
However, these crosslinking agents that crosslink with an acid are unstable to heat, and the stability during storage after the image recording material is prepared is not so good. In contrast, the molecule contains 3 to 5 benzene rings which have two or more hydroxymethyl groups or alkoxymethyl groups linked to a benzene ring and may have a substituent, and the molecular weight is 1 , 200 or less phenol derivatives have good storage stability and are most preferably used in the present invention. As an alkoxymethyl group which this phenol derivative has, a C6 or less thing is preferable. Specifically, a methoxymethyl group, an ethoxymethyl group, an n-propoxymethyl group, an i-propoxymethyl group, an n-butoxymethyl group, an i-butoxymethyl group, a sec-butoxymethyl group, and a t-butoxymethyl group are preferable. Further, alkoxy-substituted alkoxy groups such as 2-methoxyethoxy group and 2-methoxy-1-propyl group are also preferable.
Among these phenol derivatives, particularly preferable ones are listed below.
[0026]
[Chemical 1]

[0027]
[Chemical 2]

[0028]
[Chemical Formula 3]

[0029]
[Formula 4]

[0030]
[Chemical formula 5]

[0031]
Where L₁~ L₈May be the same or different and each represents a hydroxymethyl group, a methoxymethyl group or an ethoxymethyl group.
A phenol derivative having a hydroxymethyl group is a phenol compound having no corresponding hydroxymethyl group (in the above formula, L₁~ L₈Can be obtained by reacting formaldehyde) with formaldehyde in the presence of a base catalyst. At this time, in order to prevent resinification or gelation, the reaction temperature is preferably 60 ° C. or lower. Specifically, it can be synthesized by the methods described in JP-A-6-282067, JP-A-7-64285 and the like.
[0032]
A phenol derivative having an alkoxymethyl group can be obtained by reacting a corresponding phenol derivative having a hydroxymethyl group with an alcohol in the presence of an acid catalyst. At this time, in order to prevent resinification and gelation, the reaction temperature is preferably 100 ° C. or lower. Specifically, it can be synthesized by the method described in European Patent EP632003A1 and the like.
[0033]
(B) As compounds having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, European Patent Publication (hereinafter referred to as EP-A) No. 0,133,216, West German Patent No. Monomer and oligomer-melamine-formaldehyde condensates and urea-formaldehyde condensates disclosed in US Pat. Nos. 3,634,671 and 3,711,264, EP-A 0,212,482 And alkoxy-substituted compounds.
More preferred examples include, for example, melamine-formaldehyde derivatives having at least two free N-hydroxymethyl groups, N-alkoxymethyl groups or N-acyloxymethyl groups, with N-alkoxymethyl derivatives being particularly preferred.
[0034]
(C) As an epoxy-type compound, the monomer, dimer, oligomer, polymeric epoxy compound containing one or more epoxy groups can be mentioned. For example, the reaction product of bisphenol A and epichlorohydrin, the reaction product of low molecular weight phenol-formaldehyde resin and epichlorohydrin, etc. are mentioned. Other examples include epoxy resins described and used in US Pat. No. 4,026,705 and British Patent 1,539,192.
[0035]
In the present invention, the crosslinking agent that crosslinks with an acid is used in an amount of 5 to 70% by weight, preferably 10 to 65% by weight, based on the total solid content of the photosensitive layer. If the addition amount of the crosslinking agent that crosslinks with an acid is less than 5% by weight, the film strength of the image area at the time of image recording deteriorates, and if it exceeds 70% by weight, it is not preferable in terms of stability during storage.
These crosslinking agents that crosslink with an acid may be used alone or in combination of two or more.
[0036]
[(B) Compound generating acid by light or heat]
The compound that generates an acid by light or heat in the photosensitive layer of the present invention (hereinafter, appropriately referred to as an acid generator) is a compound that generates an acid upon decomposition by irradiation with light or heating at 100 ° C. or higher. The acid generated is preferably a strong acid having a pKa of 2 or less, such as sulfonic acid and hydrochloric acid. Examples of the acid generator suitably used in the present invention include onium salts such as iodonium salts, sulfonium salts, phosphonium salts, and diazonium salts. Specific examples include compounds described in JP-A-7-20629. In particular, iodonium salts, sulfonium salts, and diazonium salts having a sulfonate ion as a counter ion are preferable. Also preferred are haloalkyl-substituted s-triazines described in JP-A-7-271029.
Compounds that generate an acid by light or heat that are particularly preferably used in the present invention are compounds represented by the following general formulas (I) to (IX).
[0037]
[Chemical 6]

[0038]
Where R₁, R₂, R_FourAnd R_FiveThese may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. R_ThreeRepresents a halogen atom, an optionally substituted hydrocarbon group having 10 or less carbon atoms, or an alkoxy group having 10 or less carbon atoms.
R₆Represents a divalent hydrocarbon group having 25 or less carbon atoms which may have a substituent. n shows the integer of 0-4.
[0039]
[Chemical 7]

[0040]
Ar₁, Ar₂, Ar_Three, Ar_FourThese may be the same or different and each represents an aryl group having 20 or less carbon atoms, which may have a substituent. Specifically, phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, dodecylphenyl group, phenylphenyl group, naphthyl group, anthracenyl group, fluorophenyl group, chlorophenyl group, bromophenyl group, iodophenyl group, methoxy Phenyl group, hydroxyphenyl group, phenoxyphenyl group, nitrophenyl group, cyanophenyl group, carboxyphenyl group, anilinophenyl group, anilinocarbonylphenyl group, morpholinophenyl group, phenylazophenyl group, methoxynaphthyl group, hydroxynaphthyl group , A nitronaphthyl group, an anthraquinonyl group, and the like.
[0041]
R₇, R₈, R₉Represents a hydrocarbon group having 18 or less carbon atoms which may have a substituent.
Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, allyl group, n-butyl group, sec-butyl group, t-butyl group, hexyl group, cyclohexyl group, benzyl group, phenyl group , Tolyl group, t-butylphenyl group, naphthyl group, anthracenyl group, etc., hydrocarbon group, 2-methoxyethyl group, fluorophenyl group, chlorophenyl group, bromophenyl group, iodophenyl group, methoxyphenyl group, hydroxyphenyl group , Phenylthiophenyl group, hydroxynaphthyl group, methoxynaphthyl group, benzoylmethyl group, naphthoylmethyl group, and the like, and hydrocarbon groups having a substituent. R₇And R₈And may be bonded to each other to form a ring.
[0042]
M^-Is an anion of an organic compound or an inorganic compound, for example, SO_Four ^2-, S₂O_Three ^2-, HSO_Four ^-, SO_Three ^2-, H₂PO_Four ^-, NO_Three ^-, Halogen ions, ClO_Four ^-, BF_Four ^-, PF₆ ^-, SbF₆ ^-, BiCl_Five ^-, AsF₆ ^-, SbCl₆ ^-, SnCl₆ ^-, R-SO_Three ^-, R-COO^-, R-PO_Four ^2-Etc. However, R represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group.
[0043]
[Chemical 8]

[0044]
X represents a halogen atom. Y is -CX_Three, -NH₂, -NHR₁₁, -N (R₁₁)₂, -OR₁₁Represents. Where R₁₁Represents an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. Also R_TenIs -CX_Three(X represents a halogen), an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or a substituted alkenyl group.
Of the compounds represented by the general formula compounds (I) to (VIII), those particularly preferred are listed below.
These compounds are described in, for example, Japanese Patent Application Laid-Open Nos. 2-100054 and 2-100055, Maruzen / New Experimental Chemistry Course, Volume 2-3 (p.448), Volume 14-III, 8- 16 (p. 1838), 7/14 (p. 1564), JW Knapczyk et al., J. Am. Chem. Soc., 91, 145 (1969), AL Maycok et al., J. Org. Chem. 35, 2532 (1970), JV Crivello et al., Polym. Chem. Ed., 18, 2677 (1980), U.S. Pat. Nos. 2,807,648, 4,247,473, JP-A-53. -101331, JP-B-5-53166, and the like.
[0045]
[Chemical 9]

[0046]
[Chemical Formula 10]

[0047]
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[0048]
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[0049]
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[0050]
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[0051]
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[0052]
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[0053]
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[0054]
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[0055]
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[0056]
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[0057]
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[0058]
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[0059]
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[0060]
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[0061]
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[0062]
Examples of the compound represented by (IX) include compounds described in Wakabayashi et al., Bull. Chem. Soc. Japan, 42, 2924 (1969), such as 2-phenyl-4,6-bis (trichloromethyl). ) -S-triazine (hereinafter referred to as IX-9), 2- (p-chlorophenyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-tolyl) -4,6-bis (Trichloromethyl) -S-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (2 ′, 4′-dichlorophenyl) -4,6- Bis (trichloromethyl) -S-triazine, 2,4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6-hist (trichloromethyl) -S-triazine, 2-n-nonyl- 4,6-bis (tri Rorumechiru) -S- triazine, 2- (α, α, β- trichloroethyl) -4,6-bis (trichloromethyl) -S- triazine.
[0063]
In addition, compounds described in GB 1388492, for example, 2-styryl-4,6-bis (trichloromethyl) -S-triazine, 2- (p-methylstyryl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxystyryl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxystyryl) -4-amino-6-trichloromethyl-S-triazine, etc. And compounds described in JP-A No. 53-133428, such as 2- (4-methoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxy-naphtho) 1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- [4- (2-ethoxyethyl) -naphth-1-yl] -4,6-bis-trichloromethyl- -Triazine, 2- (4,7-dimethoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (acenaphtho-5-yl) -4,6-bis-trichloromethyl Examples include compounds described in German Patent No. 3337024, such as -S-triazine, and the following compounds.
[0064]
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[0065]
Furthermore, compounds described in JP-A-5-281728, such as the compounds shown below, can be mentioned.
[0066]
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[0067]
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[0068]
These compounds are added to the image recording material in a proportion of 0.01 to 50% by weight, preferably 0.1 to 25% by weight, more preferably 0.5 to 15% by weight, based on the total solid content of the photosensitive layer. The When the addition amount is less than 0.01% by weight, an image cannot be obtained. On the other hand, when the added amount exceeds 50% by weight, the non-image area is stained during printing.
These compounds may be used alone or in combination of two or more.
[0069]
[(C) Infrared absorber]
The infrared absorber used in the photosensitive layer of the present invention is a dye or pigment that effectively absorbs infrared rays having a wavelength of 760 nm to 1200 nm. A dye or pigment having an absorption maximum at a wavelength of 760 nm to 1200 nm is preferable.
As the dye, commercially available dyes and those known in the literature [for example, “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes Is mentioned.
[0070]
Preferred dyes include cyanine dyes described in, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, and JP-A-60-78787, and JP-A-58- No. 173696, JP-A-58-181690, JP-A-58-194595, etc., methine dyes, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187 Naphthoquinone dyes described in JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc., squarylium dyes described in JP-A-58-112792, etc., UK Examples thereof include cyanine dyes described in Japanese Patent No. 434,875.
[0071]
Also, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, pyranlium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 The pentamethine thiopyrylium salts described above and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. It is.
[0072]
Another example of a preferable dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).
Examples of commercially available dyes include NK2014, NK3555, NKX114, NK2545, NK3508, NK3509, etc. manufactured by Nippon Photosensitizer Co., Ltd., SIR128, SIR130, SIR132, SIR103, SIR152, KIR103, etc. manufactured by Nippon Kayaku Co., Ltd. IRG022, IRG002, IRG003 etc., Glendal Co. Cyasorb IR99 etc., Epoline Co. EpolightIV62B, EpolightIII 178, EpolightIII 125, EpolightIII 130, EpolightV72, EpolightV99, EpolightIII 117, EpolightIII 189, EpolightIII 57, EpolightIV62A, EpolightIV101, EpolightIII 184, Ep lightIII 192, EpolightIV67, EpolightV63, and the like.
Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes.
[0073]
Examples of the pigment used in the present invention include commercially available pigments and color index (CI) manual, “Latest Pigment Handbook” (edited by Japan Pigment Technology Association, published in 1977), “Latest Pigment Application Technology” (CMC Publishing, 1986), “Printing Ink Technology”, CMC Publishing, 1984) can be used.
Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.
[0074]
These pigments may be used without surface treatment, or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (for example, a silane coupling agent, an epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Conceivable. The above-mentioned surface treatment methods are described in “Characteristics and Application of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.
The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. If the particle size of the pigment is less than 0.01 μm, it is not preferable from the viewpoint of stability of the dispersion in the photosensitive layer coating solution, and if it exceeds 10 μm, it is not preferable from the viewpoint of uniformity of the image recording layer.
[0075]
As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).
These dyes or pigments are 0.01 to 50% by weight, preferably 0.1 to 10% by weight, particularly preferably 0.5 to 10% by weight, especially pigments, based on the total solid content of the photosensitive layer. Preferably, it can be added to the image recording material at a ratio of 1.0 to 10% by weight. When the added amount of the pigment or dye is less than 0.01% by weight, the sensitivity is lowered, and when it exceeds 50% by weight, the non-image area is easily stained during printing.
These dyes or pigments may be added to the same layer as other components, or another layer may be provided and added thereto.
[0076]
In the photosensitive layer of the present invention, the above three components (a) to (c) are essential. In addition to these, as described above, (B) a polymer having an alkali-soluble group. It is preferable to add a compound from the viewpoint of improving the strength of the image area. Details of this compound are described below.
[0077]
[(B) Polymer compound having alkali-soluble group]
The polymer compound having an alkali-soluble group that can be used together with the essential component in the present invention (hereinafter, appropriately referred to as an alkali-soluble polymer compound) refers to a resin containing an alkali-soluble group in the molecule, such as a novolak resin, Resole resin, acetone-pyrogallol resin, polyhydroxystyrenes, hydroxystyrene-N-substituted maleimide copolymer, hydroxystyrene-maleic anhydride copolymer, acrylic copolymer having an alkali-soluble group or urethane type polymer And a polymer compound obtained by reacting at least 1 mol% of a structural unit having an acidic group such as acrylic acid. Here, examples of the alkali-soluble group include a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group, a phosphonic acid group, and an imide group.
[0078]
The novolak resin that can be used in the present invention is a resin obtained by condensing phenols and aldehydes under acidic conditions. Preferred novolak resins include, for example, novolak resins obtained from phenol and formaldehyde, novolak resins obtained from m-cresol and formaldehyde, novolak resins obtained from p-cresol and formaldehyde, novolak resins obtained from o-cresol and formaldehyde, and octylphenol. And novolak resins obtained from formaldehyde, m- / p-mixed cresol and novolak resins obtained from formaldehyde, phenol / cresol (m-, p-, o- or m- / p-, m- / o-, o- / P-mixed) and a novolak resin obtained from formaldehyde.
These novolak resins preferably have a weight average molecular weight of 800 to 200,000 and a number average molecular weight of 400 to 60,000.
In the present invention, these novolak resins are used in an added amount of preferably 5 to 90% by weight, more preferably 10 to 85% by weight, particularly preferably 20 to 80% by weight in the total solid content of the photosensitive layer. When the addition amount of the novolak resin is less than 5% by weight, the durability of the photosensitive layer is deteriorated, and when it exceeds 90% by weight, it is not preferable in terms of both sensitivity and durability.
[0079]
The resol resin that can be used in the present invention is a resin obtained by condensing phenols and aldehydes under basic conditions. Preferred resole resins include resole resins obtained from phenol and formaldehyde, resole resins obtained from m-cresol and formaldehyde, resole resins obtained from bisphenol A and formaldehyde, and resole resins obtained from 4,4′-bisphenol and formaldehyde. Etc.
These resol resins preferably have a weight average molecular weight of 500 to 100,000 and a number average molecular weight of 200 to 50,000.
In the present invention, these resole resins are used in an amount of 5 to 80% by weight, more preferably 10 to 75% by weight, and particularly preferably 20 to 70% by weight in the total solid content of the photosensitive layer. If the amount of the resole resin added is less than 5% by weight, the durability of the recording layer is deteriorated, and if it exceeds 80% by weight, it is not preferable in terms of stability during storage.
[0080]
Examples of hydroxystyrene-based polymers that can be used in the present invention include poly-p-hydroxystyrene, poly-m-hydroxystyrene, p-hydroxystyrene-N-substituted maleimide copolymer, p-hydroxystyrene-maleic anhydride. A copolymer etc. are mentioned. When such a hydroxystyrene-based polymer is used, those having a weight average molecular weight of 2,000 to 500,000, preferably 4,000 to 300,000 are preferred.
[0081]
Examples of acrylic copolymers having an alkali-soluble group include methacrylic acid-allyl methacrylate copolymer, methacrylic acid-benzyl methacrylate copolymer, methacrylic acid-hydroxyethyl methacrylate copolymer, poly (hydroxyphenylmethacrylamide) , Poly (hydroxyphenylcarbonyloxyethyl acrylate), poly (2,4-dihydroxyphenylcarbonyloxyethyl acrylate), and the like. These acrylic resins are structural units having an acidic group such as a carboxyl group or a hydroxyphenyl group in the molecule. For example, (meth) acrylic acid, hydroxystyrene, hydroxyphenyl (meth) acrylamide, etc. A resin obtained by reacting 1 mol% or more of the structural unit and having a weight average molecular weight of 2,000 to 500,000, preferably 4,000 to 300,000 is preferable.
[0082]
Examples of the urethane type polymer having an alkali-soluble group include resins obtained by reacting diphenylmethane diisocyanate with hexamethylene diisocyanate, tetraethylene glycol, and 2,2-bis (hydroxymethyl) propionic acid. This urethane polymer is also preferably a resin obtained by reacting at least 1 mol% of a structural unit having an acidic group such as a carboxyl group or a hydroxyphenyl group in the molecule.
Of these alkali-soluble polymer compounds, novolak resins are preferred from the standpoint of plate durability, while hydroxystyrene polymers and acrylic copolymers having alkali-soluble groups are preferred from the standpoint of developability.
The alkali-soluble polymer compound used together with the essential components in the present invention may be used alone or in combination. The amount of these alkali-soluble polymer compounds added to the image recording material is preferably 20 to 95% by weight, more preferably 40 to 90% by weight, based on the total solid content of the photosensitive layer. When the addition amount is less than 20% by weight, the effect of improving the strength of the image area is insufficient when an image is formed. If the addition amount exceeds 95% by weight, no image is formed.
[0083]
[Other ingredients]
In addition to the essential components (A) to (C) and (B) the polymer compound, various compounds may be added to the photosensitive layer according to the present invention as necessary.
For example, a dye having a large absorption in the visible light region can be used as an image colorant.
Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (orientated chemistry) Manufactured by Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI52015), etc. And dyes described in Japanese Patent No. 293247.
[0084]
These dyes are preferably added after image formation because they can be easily distinguished from image portions and non-image portions. The amount added is 0.01 to 10% by weight based on the total solid content of the photosensitive layer.
In the photosensitive layer of the present invention, nonionic surfactants as described in JP-A-62-251740 and JP-A-3-208514 are used in order to broaden the processing stability against development conditions. , Amphoteric surfactants as described in JP-A-59-121044 and JP-A-4-13149 can be added.
Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like.
Specific examples of amphoteric surfactants include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-N, N- Examples include betaine type (for example, trade name Amorgen K, manufactured by Dai-ichi Kogyo Co., Ltd.).
The proportion of the nonionic surfactant and the amphoteric surfactant in the photosensitive layer is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.
[0085]
Furthermore, a plasticizer can be added to the photosensitive layer of the present invention, if necessary, in order to impart flexibility of the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate and the like are used.
In the photosensitive layer of the present invention, a surfactant for improving the coating property, for example, a fluorosurfactant described in JP-A-62-170950 can be added. A preferred addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the solid content of the photosensitive layer.
[0086]
The photosensitive layer of the present invention is usually coated on a support by dissolving the above components in a solvent. Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, it is not limited to these. These solvents are used alone or in combination. The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by weight. The coating amount (solid content) on the support obtained after coating and drying varies depending on the use, but generally speaking, it is 0.5 to 5.0 g / m for a planographic printing plate material.²Is preferred. Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the image recording film deteriorate.
[0087]
[Support]
The support used in the present invention is a dimensionally stable plate, for example, paper, paper laminated with plastic (for example, polyethylene, polypropylene, polystyrene, etc.), metal plate (for example, aluminum). , Zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), Examples include paper or plastic film on which a metal as described above is laminated or vapor-deposited.
[0088]
As the support of the present invention, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is at most 10% by weight. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and particularly preferably 0.2 mm to 0.3 mm.
[0089]
Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired.
The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used.
[0090]
The roughened aluminum plate is subjected to an alkali etching treatment and a neutralization treatment as necessary, and then subjected to an anodizing treatment to enhance the water retention and wear resistance of the surface as desired. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The anodizing treatment conditions vary depending on the electrolyte used, and thus cannot be specified in general. In general, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm.²A voltage of 1 to 100 V and an electrolysis time of 10 seconds to 5 minutes are suitable.
[0091]
The amount of anodized film is 1.0g / m²If it is less, the printing durability is insufficient, or the non-image part of the lithographic printing plate is easily scratched, and so-called “scratch stains” in which ink adheres to the scratched part during printing tend to occur.
After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. The hydrophilization treatment used in the present invention is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are alkali metal silicate (such as aqueous sodium silicate) methods. In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated. In addition, it is disclosed in potassium fluoride zirconate disclosed in Japanese Patent Publication No. 36-22063 and US Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid is used.
[0092]
In the negative image recording material of the present invention, an undercoat layer can be provided on the support, if necessary. Various organic compounds are used as the primer layer component. For example, phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, and phenylphosphonic acid which may have a substituent Organic phosphonic acids such as naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, optionally substituted phenylphosphoric acid, naphthylphosphonic acid, alkylphosphoric acid and glycerophosphoric acid Organic phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, organic phosphinic acids such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and hydrochloric acid of triethanolamine Hydroxy such as salt -Alanine, and hydrochlorides of amines having a group may be used in combination of two or more. The coverage of the organic undercoat layer is 2 to 200 mg / m²Is appropriate.
[0093]
As described above, a lithographic printing plate using the image recording material of the present invention can be produced. This lithographic printing plate material is image-exposed with a solid-state laser and a semiconductor laser that emit infrared rays having a wavelength of 760 nm to 1200 nm. In the present invention, the development treatment may be performed immediately after the laser irradiation, but the heat treatment is preferably performed between the laser irradiation step and the development step. It is preferable to perform the conditions of heat processing within the range of 80 to 150 degreeC for 10 second-5 minutes. This heat treatment can reduce the laser energy required for recording during laser irradiation.
[0094]
After heat treatment as necessary, the image recording material of the present invention is developed with an alkaline aqueous solution.
As the developer and replenisher for the image recording material of the present invention, conventionally known aqueous alkali solution can be used. Examples of the alkaline agent used in the developer and replenisher include sodium silicate, potassium silicate, tribasic sodium phosphate, tribasic potassium phosphate, tribasic ammonium phosphate, dibasic sodium phosphate, second Potassium phosphate, dibasic ammonium phosphate, sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium borate, potassium borate, ammonium borate, sodium hydroxide, ammonium hydroxide, hydroxylated Examples include inorganic alkali salts such as potassium and lithium hydroxide. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also used.
[0095]
These alkali agents are used alone or in combination of two or more.
Among these alkali agents, particularly preferred developers are aqueous silicate solutions such as sodium silicate and potassium silicate. The reason is silicon oxide SiO which is a component of silicate.₂And alkali metal oxide M₂This is because the developability can be adjusted by the ratio and concentration of O. For example, alkali metal silicates described in JP-A-54-62004 and JP-B-57-7427 are effective. Used.
[0096]
Further, when developing using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than that of the developer is added to the developer, so that a large amount of developer can be obtained without replacing the developer in the developer tank for a long time. It is known that lithographic printing plates can be processed. This replenishment method is also preferably applied in the present invention.
Various surfactants and organic solvents can be added to the developer and the replenisher as necessary for the purpose of promoting or suppressing developability, dispersing development residue, and improving the ink affinity of the printing plate image area. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants.
If necessary, the developer and replenisher may contain reducing agents such as hydroquinone, resorcin, sulfurous acid, bisulfite, and other inorganic acids such as sodium and potassium salts, and organic carboxylic acids, antifoaming agents, and water softeners. It can also be added.
The printing plate developed using the developer and the replenisher is post-treated with a desensitizing solution containing washing water, a rinsing solution containing a surfactant or the like, gum arabic or a starch derivative. As the post-treatment when the image recording material of the present invention is used as a printing plate, these treatments can be used in various combinations.
[0097]
In recent years, automatic developing machines for printing plate materials have been widely used in the plate making and printing industries in order to rationalize and standardize plate making operations. This automatic developing machine is generally composed of a developing section and a post-processing section. It consists of an apparatus that transports the printing plate material, each processing solution tank, and a spray device. The exposed printing plate is pumped up while being transported horizontally. Each processing solution is sprayed from a spray nozzle for development processing. In addition, recently, there is also known a method in which a printing plate material is immersed and conveyed in a processing liquid tank filled with a processing liquid by a submerged guide roll or the like. In such automatic processing, each processing solution can be processed while being supplemented with a replenisher according to the processing amount, operating time, and the like.
In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.
[0098]
The lithographic printing plate obtained as described above can be subjected to a printing process after applying a desensitized gum if desired. However, if it is desired to obtain a lithographic printing plate with a higher printing durability, a burning treatment is performed. Is given.
In the case of burning a lithographic printing plate, before burning, an adjustment as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859, JP-A-61-159655 is used. It is preferable to treat with a surface liquid.
As its method, with a sponge or absorbent cotton soaked with the surface-adjusting liquid, it is applied onto a lithographic printing plate, or a method in which the printing plate is immersed and applied in a vat filled with the surface-adjusting liquid, Application by an automatic coater is applied. Further, making the coating amount uniform with a squeegee or a squeegee roller after coating gives a more preferable result.
[0099]
The coating amount of the surface conditioning liquid is generally 0.03 to 0.8 g / m.²(Dry weight) is appropriate.
The lithographic printing plate coated with the surface conditioning liquid is dried if necessary, and then heated to a high temperature with a burning processor (for example, burning processor: BP-1300 sold by Fuji Photo Film Co., Ltd.). In this case, the heating temperature and time are in the range of 180 to 300 ° C. and preferably in the range of 1 to 20 minutes, although depending on the type of components forming the image.
The lithographic printing plate subjected to the burning treatment can be subjected to conventional treatments such as washing and gumming as needed, but a surface-conditioning solution containing a water-soluble polymer compound is used. In such a case, so-called desensitizing treatment such as gumming can be omitted.
The planographic printing plate obtained by such processing is applied to an offset printing machine or the like and used for printing a large number of sheets.
[0100]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
[Synthesis of Crosslinking Agent [HM-1] Crosslinked by Acid of the Present Invention]
10 g of 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] -4- [α, α-bis (4-hydroxyphenyl) ethyl] benzene (Trisp-PA manufactured by Honshu Chemical Industry Co., Ltd.) The solution was added to an aqueous solution of potassium hydroxide and stirred and dissolved. Next, while stirring this solution, 60 ml of 37% formalin aqueous solution was gradually added at room temperature over 1 hour. The mixture was further stirred at room temperature for 6 hours and then poured into a dilute sulfuric acid aqueous solution. The precipitate was filtered, sufficiently washed with water, and then recrystallized from 30 ml of methanol to obtain 20 g of a white powder of a phenol derivative [HM-1] having a hydroxymethyl group having the following structure. The purity was 92% (liquid chromatography method).
[0101]
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[0102]
[Synthesis of Crosslinking Agent [MM-1] Crosslinked by Acid of the Present Invention]
20 g of the phenol derivative [HM-1] having a hydroxymethyl group obtained in the above synthesis example was added to 1 liter of methanol and dissolved by heating under stirring. Next, 1 ml of concentrated sulfuric acid was added to this solution and heated under reflux for 12 hours. After completion of the reaction, the reaction solution was cooled and 2 g of potassium carbonate was added. After sufficiently concentrating the mixture, 300 ml of ethyl acetate was added. The solution was washed with water and then concentrated to dryness to obtain 22 g of a phenol derivative [MM-1] having a methoxymethyl group having the following structure as a white solid. The purity was 90% (liquid chromatography method).
[0103]
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[0104]
Further, the following phenol derivatives were synthesized in the same manner.
[0105]
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[0106]
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[0107]
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[0108]
[Examples 1 to 26, Comparative Examples 1 to 26]
An aluminum plate (material 1050) having a thickness of 0.30 mm was degreased by washing with trichlorethylene, and then the surface was grained using a nylon brush and a 400 mesh pumiston-water suspension and thoroughly washed with water. This plate was immersed in a 25% aqueous sodium hydroxide solution at 45 ° C. for 9 seconds, etched, washed with water, and further 2% HNO._ThreeFor 20 seconds and washed with water. The etching amount of the grained surface at this time is about 3 g / m.²Met. Next, this plate is 7% H₂SO_FourCurrent density 15A / dm²3g / m²After the direct current anodic oxide film was provided, it was washed with water and dried. Next, the following undercoat liquid was applied to the aluminum plate and dried at 80 ° C. for 30 seconds. The coating amount after drying is 10 mg / m²Met.
(Undercoat liquid)
β-Alanine 0.1g
Phenylphosphonic acid 0.05g
40g of methanol
60g of pure water
[0109]
Next, in the following formulation, the photosensitive layer solution was prepared by changing the type of (a) a binder, (b) a crosslinking agent that crosslinks with an acid, and (c) a compound that generates an acid by light or heat. Each of these solutions was applied to the above-mentioned undercoated aluminum plate and dried at 100 ° C. for 1 minute to obtain P-1 to P-26 plate materials. Table 1 shows the compounds used in each plate. Weight after drying is 1.7g / m²Met.
[Photosensitive layer coating solution]
(A) Cross-linking agent cross-linked with acid (shown in Table 1) 0.7 g
(B) Compounds that generate acid by light or heat (shown in Table 1) 0.2 g
(C) Infrared absorber 0.15 g
(NK-3508: trade name, manufactured by Nippon Sensitive Dye Research Co., Ltd.)
(B) Binder (shown in Table 1) 1.5 g
Additive
Victoria Pure Blue BO (C.I.44040) 0.05g
Fluorosurfactant 0.06g
(Megafuck F-177: trade name), manufactured by Dainippon Ink & Chemicals, Inc.)
solvent
Methyl ethyl ketone 15g
1-methoxy-2-propanol 5g
7g methyl alcohol
[0110]
[Table 1]

[0111]
The binders shown in Table 1 are as follows.
(B-1) Novolac resin obtained from phenol and formaldehyde
Weight average molecular weight 10,000
(B-2) Novolac resin obtained from cresol and formaldehyde
Meta / para ratio = 8/2, weight average molecular weight 5800
(B-3) Poly-p-hydroxystyrene
Weight average molecular weight 8000
[0112]
A dry coating weight of a water-soluble overcoat layer having the following composition on a plate (P-1 to P-26) coated with a photosensitive layer having the above-mentioned formulation is 2.5 g / m.²And then dried at 100 ° C. for 3 minutes.
In Comparative Examples, P-1 to P-26 were used as they were without coating this overcoat layer.
[0113]
[Prescription of overcoat layer coating solution]
(1) Preparation of mica dispersion
16 g of synthetic mica (Somasif ME-100: trade name, manufactured by Coop Chemical Co., Ltd., aspect ratio: 1000 or more) is added to 184 g of water, and average particle diameter (laser scattering method) is 3 μm using a homogenizer. Dispersion gave a mica dispersion.
[0114]
(2) Adjustment of overcoat layer coating solution
100 g of water was added to 6 g of the prepared mica dispersion, 12 g of an 8 wt% aqueous solution of polyvinyl alcohol (manufactured by PVA-124 Kuraray Co., Ltd.) was added and stirred well, and then 10 g of 2 wt% 2-ethylhexyl sulfosuccinate soda was added. An overcoat layer coating solution was obtained.
[0115]
The obtained negative lithographic printing plate was exposed with a solid-state laser YAG laser (output: 500 mW) emitting infrared rays having a wavelength of 1064 nm. After exposure, heat treatment is performed at 120 ° C. for 30 seconds, and then processed through an automatic developing machine charged with a developer manufactured by Fuji Photo Film Co., Ltd., DP-4 (1: 8), and rinse solution FR-3 (1: 7). did. At that time, the lowest exposure energy on the image-formed plate surface was taken as sensitivity, and the sensitivity was measured immediately after preparation and after storage for 3 days in an environment of 45 ° C. and 75% relative humidity. The measurement results are shown in Tables 2 and 3.
[0116]
[Table 2]

[0117]
[Table 3]

[0118]
As is apparent from Tables 2 and 3, the lithographic printing plate using the negative image recording materials of Examples 1 to 26 of the present invention has high sensitivity regardless of the type of binder, crosslinking agent, and acid generator. It can be seen that it is excellent in stability during storage at high temperature and high humidity. On the other hand, the planographic printing plates using the negative type image recording materials of Comparative Examples 1 to 26 were stored under high-temperature and high-humidity conditions, although those using a specific crosslinking agent were excellent in sensitivity immediately after preparation. However, the sensitivity was greatly reduced, and the other samples did not form images under the same conditions.
[0119]
[Examples 27 to 52]
Next, in the following formulation, a photosensitive layer solution was prepared by changing (B) a binder, (a) a crosslinking agent that crosslinks with an acid, and (b) a compound that generates an acid by light or heat. Each of these solutions was applied to the above-mentioned undercoated aluminum plate and dried at 100 ° C. for 1 minute to obtain P-27 to P-52 plate materials. Table 4 shows the compounds used in each plate. Weight after drying is 1.7g / m²Met.
[Photosensitive layer coating solution]
(I) Substance cross-linked by acid (shown in Table 4) 0.8 g
(B) Compounds that generate acid by light or heat (shown in Table 4) 0.2 g
(C) Infrared absorber 0.15 g
(NK-2014: trade name, manufactured by Nippon Sensitive Dye Research Co., Ltd.)
(B) Binder (shown in Table 4) 1.6 g
Additive
Victoria Pure Blue BO (C.I.44040) 0.05g
Fluorosurfactant 0.06g
(Megafuck F-177: trade name), manufactured by Dainippon Ink & Chemicals, Inc.)
solvent
Methyl ethyl ketone 15g
1-methoxy-2-propanol 5g
7g methyl alcohol
[0120]
[Table 4]

[0121]
On the plate (P-27 to P-52) on which the photosensitive layer of the above formulation was coated, the same overcoat layer as used in Examples 1 to 26 was dried at a coating weight of 2.2 g / m.²And then dried at 100 ° C. for 3 minutes.
In the comparative example, P-27 to P-52 were used as they were without coating this overcoat layer.
The obtained negative lithographic printing plate was exposed with a semiconductor laser (output: 500 mW) emitting infrared rays having a wavelength of 840 nm. After exposure, heat treatment is performed at 120 ° C. for 1 minute, and then processed through an automatic developing machine charged with a developer manufactured by Fuji Photo Film Co., Ltd., DP-4 (1: 8), and rinse solution FR-3 (1: 7). did. Tables 5 and 6 show the results of measuring the sensitivity immediately after preparation of each plate material and after storage at 50 ° C. for 3 days.
[0122]
[Table 5]

[0123]
[Table 6]

[0124]
As is clear from Tables 6 and 7, the planographic printing plate material using the negative image recording materials of Examples 27 to 52 of the present invention is high regardless of the binder, crosslinking agent, and acid generator used. It can be seen that it is sensitive and has excellent stability during storage under high temperature and high humidity conditions. On the other hand, the planographic printing plates using the negative type image recording materials of Comparative Examples 27 to 52 were stored under high-temperature and high-humidity conditions, although those using a specific cross-linking agent were excellent in sensitivity immediately after preparation. However, the sensitivity was greatly reduced, and the other samples did not form images under the same conditions.
[0125]
[Examples 53 to 58, Comparative Examples 53 to 58]
The negative lithographic printing plate material (P-42) used in the above Examples and Comparative Examples was exposed with a semiconductor laser (output: 500 mW) emitting infrared light having a wavelength of 840 nm. After the exposure, the heating temperature and the heating time were changed and processed, and then passed through an automatic developing machine charged with a developer manufactured by Fuji Photo Film Co., Ltd., DP-4 (1: 8), and rinse solution FR-3 (1: 7). Processed.
[0126]
[Table 7]

[0127]
As is clear from Table 7, the recording materials of Examples 53 to 58 (with an overcoat layer) had high sensitivity regardless of the heating temperature and heating time, but Comparative Examples 53 to 58 (without an overcoat layer). In this case, a decrease in sensitivity was observed even with a heating time of 30 seconds, and no image was formed with a heating time of 60 seconds. Therefore, the planographic printing plate material using the negative image recording material of the present invention was exposed to light. It can be seen that the tolerance of the subsequent heat treatment conditions is excellent.
[0128]
【The invention's effect】
The negative lithographic printing plate material of the present invention can be directly made from digital data of a computer or the like by recording using a solid-state laser and a semiconductor laser emitting infrared rays, and has high sensitivity, high temperature and high humidity. Excellent stability during storage under conditions, and excellent tolerance for heat treatment conditions after exposure.

Claims (5)

A negative type characterized in that a photosensitive layer containing the following components (a) to (c) and an overcoat layer containing a flat inorganic layered compound are sequentially provided on a support. Image recording material.
(A) Substances that crosslink with acids,
(B) a compound that generates an acid by light or heat,
(C) Infrared absorber.   The negative image recording material according to claim 1, wherein the aspect ratio of the inorganic stratiform compound contained in the overcoat layer is 100 or more.   The negative image recording material according to claim 1, wherein an aspect ratio of the inorganic stratiform compound contained in the overcoat layer is 200 or more. Negative image recording material according to any one of claims 1 to 3 inorganic stratiform compound contained in the overcoat layer is characterized in that it is a mica. Negative image recording material according to any one of claims 1 to 4 the inorganic stratiform compound contained in the overcoat layer and wherein the swellable fluorinated synthetic mica.