JP4113308B2 - Alkali development processing plate making method of planographic printing plate - Google Patents

Description

【００５２】
式中、Ｘ¹、Ｘ²は、それぞれ独立に酸素原子又はＮＲ⁷を表す。Ｒ¹、Ｒ⁴は、それぞれ独立に水素原子又はＣＨ₃を表す。Ｒ²、Ｒ⁵、Ｒ⁹、Ｒ¹²、Ｒ¹⁶は、それぞれ独立に置換基を有していてもよい炭素数１〜１２のアルキレン基、シクロアルキレン基、アリーレン基又はアラルキレン基を表す。Ｒ³、Ｒ⁷、Ｒ¹³は、それぞれ独立に水素原子、置換基を有していてもよい炭素数１〜１２のアルキル基、シクロアルキル基、アリール基又はアラルキル基を表す。また、Ｒ⁶、Ｒ¹⁷は、それぞれ独立に置換基を有していてもよい炭素数１〜１２のアルキル基、シクロアルキル基、アリール基、アラルキル基を表す。Ｒ⁸、Ｒ¹⁰、Ｒ¹⁴は、それぞれ独立に水素原子又はＣＨ₃を表す。Ｒ¹¹、Ｒ¹⁵は、それぞれ独立に単結合又は置換基を有していてもよい炭素数１〜１２のアルキレン基、シクロアルキレン基、アリーレン基又はアラルキレン基を表す。Ｙ¹、Ｙ²は、それぞれ独立に単結合又はＣＯを表す。
【００５３】
中でも、ｍ−アミノスルホニルフェニルメタクリレート、Ｎ−（ｐ−アミノスルホニルフェニル）メタクリルアミド、Ｎ−（ｐ−アミノスルホニルフェニル）アクリルアミド等を好適に使用することができる。
【００５４】
（３）活性イミド基を有するアルカリ可溶性高分子化合物としては、例えば、活性イミド基を有する化合物を主たるモノマー構成単位とする重合体を挙げることができる。
活性イミド基を有する化合物を主たるモノマー構成単位とする重合体としては、１分子中に、下記式で表される活性イミド基と、重合可能な不飽和結合とをそれぞれ１以上有する低分子化合物からなるモノマーを単独重合、或いは、該モノマーに他の重合性モノマーを共重合させて得られる高分子化合物を挙げることができる。
【００５５】
【化２】

【００５６】
このような化合物としては、具体的には、Ｎ−（ｐ−トルエンスルホニル）メタクリルアミド、Ｎ−（ｐ−トルエンスルホニル）アクリルアミド等を好適に挙げることができる。
【００５７】
さらに、上記のほか、前記フェノール基を有する重合性モノマー、スルホンアミド基を有する重合性モノマー、及び活性イミド基を有する重合性モノマーのうちのいずれか２種類以上を重合させた高分子化合物、或いは、これら２種以上の重合性モノマーにさらに他の重合性モノマーを共重合させて得られる高分子化合物も好適に挙げられる。
【００５８】
フェノール基を有する重合性モノマー（Ｍ１）に、スルホンアミド基を有する重合性モノマー（Ｍ２）及び／又は活性イミド基を有する重合性モノマー（Ｍ３）を共重合させる場合の配合比（Ｍ１：Ｍ２及び／又はＭ３；重量比）としては、５０：５０〜５：９５が好ましく、４０：６０〜１０：９０がより好ましい。
【００５９】
アルカリ可溶性高分子化合物が、前記酸性基（１）〜（３）より選ばれるいずれかを有するモノマー構成単位と、他の重合性モノマーの構成単位とから構成される共重合体である場合、該共重合体中に、前記酸性基（１）〜（３）より選ばれるいずれかを有するモノマー構成単位を１０モル％以上含むことが好ましく、２０モル％以上含むことがより好ましい。
前記モノマー構成単位の含有量が、１０モル％未満であると、十分なアルカリ可溶性が得られずに、現像ラチチュードが狭くなることがある。
【００６０】
前記共重合体の合成方法としては、従来より公知のグラフト共重合法、ブロック共重合法、ランダム共重合法等を用いることができる。
【００６１】
前記酸性基（１）〜（３）より選ばれるいずれかを有するモノマーを構成単位とする重合性モノマーと共重合させる、他の重合性モノマーとしては、例えば、下記（ａ）〜（ｌ）に挙げるモノマーを挙げることができるが、本発明においては、これらに限定されるものではない。
【００６２】
（ａ）２−ヒドロキシエチルアクリレート又は２−ヒドロキシエチルメタクリレート等の脂肪族水酸基を有するアクリル酸エステル類、メタクリル酸エステル類。
（ｂ）アクリル酸メチル、アクリル酸エチル、アクリル酸プロピル、アクリル酸ブチル、アクリル酸アミル、アクリル酸ヘキシル、アクリル酸オクチル、アクリル酸ベンジル、アクリル酸−２−クロロエチル、グリシジルアクリレート、Ｎ−ジメチルアミノエチルアクリレート等のアルキルアクリレート。
（ｃ）メタクリル酸メチル、メタクリル酸エチル、メタクリル酸プロピル、メタクリル酸ブチル、メタクリル酸アミル、メタクリル酸ヘキシル、メタクリル酸シクロヘキシル、メタクリル酸ベンジル、メタクリル酸−２−クロロエチル、グリシジルメタクリレート、Ｎ−ジメチルアミノエチルメタクリレート等のアルキルメタクリレート。
【００６３】
（ｄ）アクリルアミド、メタクリルアミド、Ｎ−メチロールアクリルアミド、Ｎ−エチルアクリルアミド、Ｎ−ヘキシルメタクリルアミド、Ｎ−シクロヘキシルアクリルアミド、Ｎ−ヒドロキシエチルアクリルアミド、Ｎ−フェニルアクリルアミド、Ｎ−ニトロフェニルアクリルアミド、Ｎ−エチル−Ｎ−フェニルアクリルアミド等のアクリルアミド又はメタクリルアミド。
（ｅ）エチルビニルエーテル、２−クロロエチルビニルエーテル、ヒドロキシエチルビニルエーテル、プロピルビニルエーテル、ブチルビニルエーテル、オクチルビニルエーテル、フェニルビニルエーテル等のビニルエーテル類。
（ｆ）ビニルアセテート、ビニルクロロアセテート、ビニルブチレート、安息香酸ビニル等のビニルエステル類。
（ｇ）スチレン、α−メチルスチレン、メチルスチレン、クロロメチルスチレン等のスチレン類。
【００６４】
（ｈ）メチルビニルケトン、エチルビニルケトン、プロピルビニルケトン、フェニルビニルケトン等のビニルケトン類。
（ｉ）エチレン、プロピレン、イソブチレン、ブタジエン、イソプレン等のオレフィン類。
（ｊ）Ｎ−ビニルピロリドン、Ｎ−ビニルカルバゾール、４−ビニルピリジン、アクリロニトリル、メタクリロニトリル等。
（ｋ）マレイミド、Ｎ−アクリロイルアクリルアミド、Ｎ−アセチルメタクリルアミド、Ｎ−プロピオニルメタクリルアミド、Ｎ−（ｐ−クロロベンゾイル）メタクリルアミド等の不飽和イミド。
（ｌ）アクリル酸、メタクリル酸、無水マレイン酸、イタコン酸等の不飽和カルボン酸。
【００６５】
前記アルカリ水可溶性高分子化合物としては、単独重合体、共重合体に関わらず、膜強度の点で、重量平均分子量が２０００以上、数平均分子量が５００以上のものが好ましく、重量平均分子量が５０００〜３０００００、数平均分子量が８００〜２５００００であり、分散度（重量平均分子量／数平均分子量）が１．１〜１０のものがより好ましい。
また、前記アルカリ可溶性高分子化合物が、フェノール−ホルムアルデヒド樹脂、クレゾール−アルデヒド樹脂等である場合には、重量平均分子量が５００〜２００００であって、数平均分子量が２００〜１００００のものが好ましい。
【００６６】
前記アルカリ水可溶性高分子化合物の含有量としては、画像形成層の全固形分重量に対して３０〜９９重量％が好ましく、４０〜９５重量％がより好ましく、５０〜９０重量％が最も好ましい。
前記含有量が、３０重量％未満であると、画像形成層の耐久性が低下することがあり、９９重量％を越えると、感度、耐久性が低下することがある。
また、前記高分子化合物は、１種類のみを用いても、２種類以上を組合わせて用いてもよい。
【００６７】
−（Ｃ）前記アルカリ可溶性高分子化合物と相溶させて該アルカリ可溶性高分子化合物のアルカリ水溶液への溶解性を低下させるとともに、加熱により該溶解性低下作用が減少する化合物−
この（Ｃ）成分は、分子内に存在する水素結合性の官能基の働きにより、前記（Ｂ）アルカリ可溶性高分子化合物との相溶性が良好であり、均一な画像形成層用塗布液を形成しうるとともに、アルカリ可溶性高分子化合物との相互作用により、該アルカリ可溶性高分子化合物のアルカリ可溶性を抑制する機能（溶解性抑制作用）を有する化合物を指す。
【００６８】
また、加熱によりアルカリ可溶性高分子化合物に対する前記溶解性抑制作用は消滅するが、この赤外線吸収剤自体が加熱により分解する化合物である場合には、分解に十分なエネルギーが、レーザー出力や照射時間等の諸条件により付与されないと、アルカリ可溶性高分子化合物の溶解性抑制作用を十分に低下させることができず、感度が低下するおそれがある。このため、（Ｃ）成分の熱分解温度としては、１５０℃以上が好ましい。
【００６９】
（Ｃ）成分としては、前記（Ｂ）アルカリ可溶性高分子化合物との相互作用を考慮して、例えば、スルホン化合物、アンモニウム塩、ホスホニウム塩、アミド化合物等の前記アルカリ可溶性高分子化合物と相互作用しうる化合物の中から適宜選択することができる。
特に、例えば、前記（Ｂ）成分として、ノボラック樹脂を単独で用いる場合には、後述する「（Ａ＋Ｃ）成分」が好ましく、以下に例示するシアニン染料Ａ等がより好ましい。（Ａ＋Ｃ）成分については後述する。
【００７０】
（Ｃ）成分と前記（Ｂ）アルカリ可溶性高分子化合物との配合比（Ｃ／Ｂ）としては、一般に１／９９〜２５／７５が好ましい。
前記混合比が、１／９９未満、即ち、（Ｃ）成分が少なすぎると、アルカリ可溶性高分子化合物との相互作用が不十分となり、アルカリ可溶性を低下させることができず、良好に画像形成することができないことがあり、２５／７５を超える、即ち、（Ｃ）成分が多すぎると、相互作用が過大となり、感度が著しく低下することがある。
【００７１】
−(Ａ＋Ｃ)成分−
本発明においては、前記（Ａ）成分及び（Ｃ）成分に代えて、これら双方の特性を有する化合物（（Ａ＋Ｃ）成分）を用いることができる。
前記（Ａ＋Ｃ）成分は、光を吸収して熱を発生する性質（即ち、(Ａ)成分の特性）を有し、しかも７００〜１２００ｎｍの波長領域に吸収域を持つと共に、さらにアルカリ可溶性高分子化合物と良好に相溶しうる塩基性染料である。
（Ａ＋Ｃ）成分は、その分子内にアンモニウム基、イミニウム基等のアルカリ可溶性高分子化合物と相互作用する基を有する（即ち、(Ｃ)成分の特性）ため、前記高分子化合物と相互作用して、そのアルカリ可溶性を抑制することができる。
前記（Ａ＋Ｃ）成分としては、例えば、下記一般式（Ｚ）で表される化合物を挙げることができる。
【００７２】
【化３】

【００７３】
前記一般式（Ｚ）中、Ｒ²¹〜Ｒ²⁴は、それぞれ独立に水素原子、又は置換基を有していてもよい炭素数１〜１２のアルキル基、アルケニル基、アルコキシ基、シクロアルキル基、アリール基を表し、Ｒ²¹とＲ²²、Ｒ²³とＲ²⁴はそれぞれ結合して環構造を形成していてもよい。
Ｒ²¹〜Ｒ²⁴としては、例えば、水素原子、メチル基、エチル基、フェニル基、ドデシル基、ナフチル基、ビニル基、アリル基、シクロヘキシル基等が挙げられ、これらの基は、さらに置換基を有していてもよい。ここで、置換基としては、例えば、ハロゲン原子、カルボニル基、ニトロ基、ニトリル基、スルホニル基、カルボキシル基、カルンボン酸エステル、スルホン酸エステル等が挙げられる。
【００７４】
式中、Ｒ²⁵〜Ｒ³⁰は、それぞれ独立に置換基を有していてもよい炭素数１〜１２のアルキル基を表し、前記Ｒ²⁵〜Ｒ³⁰としては、例えば、メチル基、エチル基、フェニル基、ドデシル基、ナフチル基、ビニル基、アリル基、シクロヘキシル基等が挙げられ、これらの基は、さらに置換基を有していてもよい。ここで、置換基としては、例えば、ハロゲン原子、カルボニル基、ニトロ基、ニトリル基、スルホニル基、カルボキシル基、カルボン酸エステル、スルホン酸エステル等が挙げられる。
【００７５】
式中、Ｒ³¹〜Ｒ³³は、それぞれ独立に水素原子、ハロゲン原子、又は置換基を有してもよい炭素数１〜８のアルキル基を表し、前記Ｒ³²は、前記Ｒ³¹又はＲ³³と結合して環構造を形成していてもよく、ｍ＞２の場合は、複数のＲ³²同士が結合して環構造を形成していてもよい。
前記Ｒ³¹〜Ｒ³³としては、例えば、塩素原子、シクロヘキシル基、Ｒ³²同士が結合してなるシクロペンチル環、シクロヘキシル環等が挙げられ、これらの基は、さらに置換基を有していてもよい。ここで、置換基としては、例えば、ハロゲン原子、カルボニル基、ニトロ基、ニトリル基、スルホニル基、カルボキシル基、カルボン酸エステル、スルホン酸エステル等が挙げられる。
また、ｍは、１〜８の整数を表し、中でも、１〜３が好ましい。
【００７６】
式中、Ｒ³⁴〜Ｒ³⁵は、それぞれ独立に水素原子、ハロゲン原子、又は置換基を有してもよい炭素数１〜８のアルキル基を表し、前記Ｒ³⁴は、Ｒ³⁵と結合して環構造を形成していてもよく、ｍ＞２の場合は、複数のＲ³⁴同士が結合して環構造を形成していてもよい。
前記Ｒ³⁴〜Ｒ³⁵としては、例えば、塩素原子、シクロヘキシル基、Ｒ³⁴同士が結合してなるシクロペンチル環、シクロヘキシル環等が挙げられ、これらの基は、さらに置換基を有していてもよい。ここで、置換基としては、例えば、ハロゲン原子、カルボニル基、ニトロ基、ニトリル基、スルホニル基、カルボキシル基、カルボン酸エステル、スルホン酸エステル等が挙げられる。
また、ｍは、１〜８の整数を表し、中でも、１〜３が好ましい。
【００７７】
式中、Ｘ-は、アニオンを表し、例えば、過塩素酸、四フッ化ホウ酸、六フッ化リン酸、トリイソプロピルナフタレンスルホン酸、５−ニトロ−Ｏ−トルエンスルホン酸、５−スルホサリチル酸、２，５−ジメチルベンゼンスルホン酸、２，４，６−トリメチルベンゼンスルホン酸、２−ニトロベンゼンスルホン酸、３−クロロベンゼンスルホン酸、３−ブロモベンゼンスルホン酸、２−フルオロカプリルナフタレンスルホン酸、ドデシルベンゼンスルホン酸、１−ナフトール−５−スルホン酸、２−メトキシ−４−ヒドロキシ−５−ベンゾイル−ベンゼンスルホン酸及びパラトルエンスルホン酸等が挙げられる。
中でも、六フッ化リン酸、トリイソプロピルナフタレンスルホン酸、２，５−ジメチルベンゼンスルホン酸等のアルキル芳香族スルホン酸が好ましい。
【００７８】
前記一般式（Ｚ）で表される化合物は、一般にシアニン染料と呼ばれる化合物であり、具体的には、以下に示す化合物が好適に用いられるが、本発明においては、これらに限られるものではない。
【００７９】
【化４】

【００８０】
上述の（Ａ）成分及び（Ｃ）成分に代えて、これら双方の特性を有する前記（Ａ＋Ｃ）成分を用いる場合、該（Ａ＋Ｃ）成分と前記（Ｂ）成分との使用量比〔（Ａ＋Ｃ）／（Ｂ）〕としては、１／９９〜３０／７０が好ましく、１／９９〜２５／７５がより好ましい。
【００８１】
以下は、ネガ型平版印刷版の記録層を構成する成分である。
−（Ｄ）熱により酸を発生する化合物−
本発明の画像形成材料がネガ型の場合、加熱時に酸を発生する化合物（以下、「酸発生剤」という。）を併用する。この酸発生剤は、１００℃以上に加熱することにより分解して酸を発生する化合物を指す。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。
前記酸発生剤としては、特願平１１−６６７３３号に記載のものが挙げられる。
【００８２】
前記酸発生剤の添加量としては、画像形成層の全固形分重量に対し０．０１〜５０重量％が好ましく、０．１〜４０重量％がより好ましく、０．５〜３０重量％が最も好ましい。
【００８３】
−（Ｅ）酸により架橋する架橋剤−
本発明の平版印刷用原版がネガ型である場合、酸により架橋する架橋剤（以下、単に「架橋剤」という場合がある。）を併用する。
前記架橋剤としては、以下のものを挙げることができる。
（ｉ）アルコキシメチル基又はヒドロキシメチル基で置換された芳香族化合物（ii）Ｎ−ヒドロキシメチル基、Ｎ−アルコキシメチル基又はＮ−アシルオキシメチル基を有する化合物
（iii）エポキシ化合物
さらに、特願平１０−５３７８８号に記載のものやフェノール誘導体等も挙げることができる。
【００８４】
前記架橋剤の添加量としては、画像形成層の全固形分重量に対し５〜８０重量％が好ましく、１０〜７５重量％がより好ましく、２０〜７０重量％が最も好ましい。
前記フェノール誘導体を架橋剤として使用する場合、該フェノール誘導体の添加量としては、画像形成材料の全固形分重量に対し５〜７０重量％が好ましく、１０〜５０重量％がより好ましい。
上記の各種化合物の詳細については、特願平１１−６６７３３号に記載されている。
【００８５】
−その他の成分−
本発明のアルカリ現像処理液を適用するのに好適な平版印刷用原版の画像形成層には、必要に応じて、さらに種々の添加剤を添加することができる。
例えば、感度を向上させる目的で、環状酸無水物類、フェノール類、有機酸類、スルホニル化合物類等の公知の添加剤を併用することもできる。
前記他の環状酸無水物、フェノール類、有機酸類又はスルホニル化合物類の添加量としては、画像形成層の全固形分重量に対し、０．０５〜２０重量％が好ましく、０．１〜１５重量％がより好ましく、０．１〜１０重量％が最も好ましい。
【００８６】
また、現像条件に対する処理性の安定性を拡げる目的で、特開昭６２−２５１７４０号公報、特開平３−２０８５１４号公報等に記載の非イオン界面活性剤、特開昭５９−１２１０４４号公報、特開平４−１３１４９号公報等に記載の両性界面活性剤を添加することができる。
前記非イオン界面活性剤又は両性界面活性剤の使用量としては、画像形成層の全固形分重量に対し、０．０５〜１５重量％が好ましく、０．１重量％がより好ましい。
【００８７】
前記画像形成層には、露光による加熱後、直ちに可視像を得るための焼き出し剤や画像着色剤としての染料や顔料を加えることができる。
前記焼き出し剤としては、例えば、露光による加熱によって酸を発生する化合物と塩を形成しうる有機染料との組合せが挙げられる。
具体的には、特開昭５０−３６２０９号、特開昭５３−８１２８号の各公報に記載の、ｏ−ナフトキノンジアド−４−スルホン酸ハロゲニドと塩形成性有機染料との組合せ、特開昭５３−３６２２３号、特開昭５４−７４７２８号、特開昭６０−３６２６号、特開昭６１−１４３７４８号、特開昭６１−１５１６４４号及び特開昭６３−５８４４０号の各公報に記載の、トリハロメチル化合物と塩形成性有機染料との組合せ、が挙げられる。
前記トリハロメチル化合物としては、オキサゾール系化合物とトリアジン系化合物があり、いずれも経時安定性に優れ、明瞭な焼き出し画像を与える。
前記画像着色剤としては、例えば、前記塩形成性有機染料以外に、他の染料を用いることができ、例えば、油溶性染料、塩基性染料が好適に挙げられる。
【００８８】
具体的には、オイルイエロー＃１０１、オイルイエロー＃ｌ０３、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（Ｃ．Ｉ．４２５５５）、メチルバイオレット（Ｃ．Ｉ．４２５３５）、エチルバイオレッド、ローダミンＢ（Ｃ．Ｉ．１４５１７０Ｂ）、マラカイトグリーン（Ｃ．Ｉ．４２０００）、メチレンブルー（Ｃ．Ｉ．５２０１５）等を挙げることができる。また、特開昭６２−２９３２４７号公報に記載の染料は、特に好ましい。
【００８９】
前記各種染料の添加量としては、画像形成層の全固形分重量に対し、０．０１〜１０重量％が好ましく、０．１〜３重量％がより好ましい。
【００９０】
また、必要に応じて、その塗膜に柔軟性等を付与する目的で、可塑剤や、以下の種々添加剤を添加することができる。
例えば、オニウム塩、ｏ−キノンジアジド化合物、芳香族スルホン化合物、芳香族スルホン酸エステル化合物等の、熱分解性で、未分解状態ではアルカリ水可溶性高分子化合物の溶解性を実質的に低下させる化合物を併用することができる。該化合物の添加は、画像部の現象液への溶解阻止能の向上を図る点で好ましい。
【００９１】
前記オニウム塩、ｏ−キノンジアジド化合物、芳香族スルホン酸エステル等の添加量としては、画像形成層の全固形分重量に対し、０．１〜５０重量％が好ましく、０．５〜３０重量％がより好ましく、０．５〜２０重量％が最も好ましい。
【００９２】
−支持体−
画像形成層を設けるための支持体としては、例えば、純アルミニウム板、アルミニウム合金板、アルミニウムがラミネート若しくは蒸着されたプラスチックフィルム等が挙げられる。
アルミニウム板の表面は、砂目立て処理、ケイ酸ソーダ、フッ化ジルコニウム酸カリウム、リン酸塩等の水溶液への浸透処理、或いは、陽極酸化処理等の表面処理が施されていることが好ましい。
また、米国特許第２，７１４，０６６号明細に記載の、砂目立てした後にケイ酸ナトリウム水溶液中で浸漬処理したアルミニウム板、特公昭４７−５１２５号公報に記載の、アルミニウム板を陽極酸化処理した後、アルカリ金属ケイ酸塩の水溶液中で浸漬処理したアルミニウム板も好ましい。
【００９３】
平版印刷用原版は、感光層として、画像形成層を所望の支持体上に塗布することにより作製することができるが、前記画像形成層の形成前に、必要に応じて、支持体上に下塗り層を設けることもできる。
下塗り層に用いる成分としては、種々の有機化合物が挙げられ、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等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及びエチレンジホスホン酸等の有機ホスホン酸；置換基を有してもよいフェニルリン酸、ナフチルリン酸、アルキルリン酸及びグリセロリン酸等の有機リン酸；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及びグリセロホスフィン酸等の有機ホスフィン酸；グリシンやβ−アラニン等のアミノ酸類；トリエタノールアミンの塩酸塩等のヒドロキシル基を有するアミンの塩酸塩等が挙げられる。
【００９４】
前記下塗り層の乾燥塗布量としては、２〜２００ｍｇ／ｍ²が好ましく、５〜１００ｍｇ／ｍ²がより好ましい。
前記乾燥塗布量が、２ｍｇ／ｍ²未満であると、十分な膜性が得られないことがある。一方、２００ｍｇ／ｍ²を超えて塗布しても、それ以上の効果を得ることはできない。
【００９５】
本発明のアルカリ現像処理液により現像する平版印刷用原版は、一般に、上述の各種成分（前記成分（Ａ）〜（Ｅ）及びその他の成分）を溶媒に溶解して画像形成層用塗布液とし、これを所望の支持体上に塗布して作製する。
前記溶媒としては、例えば、エチレンジクロライド、シクロヘキサノン、メチルエチレケトン、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、テトラメチルグレア、Ｎ−メチルピロリドン、ジメチルスルホキシド、スルホラン、α−ブチロラクトン、トルエン等が挙げられるが、本発明においては、これらに限定されるものではない。
また、前記溶媒は、単独でも２種以上を混合してもよい。
【００９６】
前記溶媒中における各種成分（前記成分（Ａ）〜（Ｅ）及びその他の成分）の全固形分濃度としては、１〜５０重量％が好ましい。
また、支持体上に塗布、乾燥して設けられる画像形成層の乾燥塗布量（固形分）としては、一般的に０．５〜５．０ｇ／ｍ²が好ましい。
【００９７】
支持体上に塗布する方法としては、公知の種々の方法の中から適宜選択できるが、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、グレード塗布、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、画像形成層の被膜特性は低下する。
【００９８】
前記画像形成層用塗布液中には、塗布性を良化する目的で、界面活性剤、例えば、特開昭６２−１７０９５０号公報に記載のフッ素系界面活性剤等を添加することがてきる。
前記添加量としては、画像形成層の全固形分重量に対して０．０１〜１重量％が好ましく、０．０５〜０．５重量％がより好ましい。
【００９９】
本発明の平版印刷用原版は、赤外線レーザーで記録することができる他、紫外線ランプによる記録やサーマルヘッド等による熱的な記録も可能である。
前記赤外線レーザーとしては、波長７００〜１２００ｎｍの赤外線を放射するレーザーが好ましく、同波長範囲の赤外線を放射する固体レーザー又は半導体レーザーがより好ましい。
【０１００】
【実施例】
以下、実施例により、本発明を詳細に説明するが、本発明はこれらに制限されるものではない。なお、実施例中の「％」は、全て「重量％」を表す。
【０１０１】
＜平版印刷用原版の作製＞
０．３ｍｍ厚のアルミニウム板（材質１０５０）をトリクロロエチレンで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−水懸濁液を用い、この表面を砂目立てし、水でよく洗浄した。
洗浄後、このアルミニウム板を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、水洗した後、さらに２０％硝酸水溶液に２０秒間浸漬し、再度水洗した。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。
【０１０２】
次に、このアルミニウム板を７％硫酸を電解液として、電流密度１５Ａ／ｄｍ²の直流電流で３ｇ／ｍ²の陽極酸化被膜を設けた後、水洗、乾燥した。
これを、３０℃のケイ酸ナトリウム２．５％水溶液で１０秒処理し、下記下塗り層用塗布液を塗布し、８０℃下で１５秒間乾燥して支持体を得た。乾燥後の下塗り層の乾燥塗布量は、１５ｍｇ／ｍ²であった。
【０１０３】
＜下塗り層用塗布液＞
・下記共重合体Ｐ（分子量２８０００） ・・・ ０．３ｇ
・メタノール ・・・１００ｇ
・水 ・・・ １ｇ
【０１０４】
【化５】

【０１０５】
得られた支持体上に下記画像形成層用塗布液を、乾燥塗布量が１．８ｇ／ｍ²となるように塗布し、ポジ型の平版印刷用原版を得た。
【０１０６】
＜画像形成層用塗布液＞
・ｍ，ｐ−クレゾールノボラック〔（Ｂ）成分〕 ・・・ １．０ｇ
（ｍ／ｐ比＝６／４，重量平均分子量８０００、
未反応クレゾールを０．５％含有）
・シアニン染料Ａ〔（Ａ＋Ｃ）成分〕 ・・・ ０．１ｇ
・無水フタル酸〔（Ｄ）成分〕 ・・・ ０．０５ｇ
・ｐ−トルエンスルホン酸 ・・・ ０．００２ｇ
・エチルバイオレット ・・・ ０．０２ｇ
（対イオン：６−ヒドロキシ−β−ナフタレンスルホン酸）
・ナフトキノン１，２−ジアジド−５−スルホニルクロリドと
ピロガロール−アセトン樹脂とのエステル化物 ・・・ ０．０１ｇ
・フッ素系界面活性剤 ・・・ ０．０５ｇ
（商品名：メガファックＦ−１７７，大日本インキ化学工業（株）製）
・メチルエチルケトン ・・・ ８ｇ
・１−メトキシ−２−プロパノール ・・・ ４ｇ
【０１０７】
（実施例１〜８）
＜ＳｉＯ₂含有のアルカリ現像処理液補充液の調製＞
酸化ケイ素ＳｉＯ₂及び酸化カリウムＫ₂Ｏの混合モル比ＳｉＯ₂／Ｋ₂Ｏが１．１のケイ酸カリウム４．０％水溶液１Ｌに各種界面活性剤を下記表１に記載の量添加し、アルカリ現像処理液（１）〜（８）を作製した。
また、酸化ケイ素ＳｉＯ₂及び酸化カリウムＫ₂Ｏの混合モル比ＳｉＯ₂／Ｋ₂Ｏが１．１のケイ酸カリウム６．０％水溶液１Ｌに各種界面活性剤を下記表１に記載の量添加し、アルカリ現像補充液（１）〜（８）を作製した。
ここで用いた各種界面活性剤の詳細を以下に示す。
【０１０８】
【化６】

【０１０９】
上記より得られた平版印刷用原版に出力５００ｍＷ、波長８３０ｎｍ、ビーム径１７μｍ（１／ｅ²）の半導体レーザーを用いて主走査速度５ｍ／秒にて露光し、２５℃に保持した。
この平版印刷用原版を、前記アルカリ現像処理液（１）を満たした自動現像機ＰＳ９００ＮＰ（富士写真フイルム（株）製）により、現像処理し、１枚処理する毎に、前記アルカリ現像補充液（１）を１００ｍｌ／ｍ²の補充量で添加し、１０枚目、５０枚目、１００枚目の平版印刷版の製版を行なった。現像処理が終了したのち、水洗工程を経て、製版が完了した平版印刷版を得た。
同様にして、表１に記載の現像液と補充液を用いて、平版印刷版原版の現像処理を行ない実施例２〜８の方法により平版印刷版を得た。
【０１１０】
＜画像部／非画像部のバランスの評価＞
（非画像部の現像性の評価）
上記のようにして得た１０枚目、５０枚目、１００枚目の平版印刷版の「非画像部の残膜」を下記基準に従い目視により観察し、官能評価を行なった。評価結果を以下の表１に示す。
−基準−
○：十分に現像され、非画像部上の画像形成層の残存は認められなかった。
△：非画像部上に画像形成層が若干残存していた。
×：現像不良が認められ、非画像部上に画像形成層が残存していた。
【０１１１】
（画像部の膜べりの評価）
上記のようにして得た１０枚目、５０枚目、１００枚目の平版印刷版の「画像部の欠陥」を下記基準に従い、目視により観察し、官能評価を行なった。評価結果を以下の表１に示す。
−基準−
○：画像部に欠陥は認められなかった。
△：画像部濃度が若干低下し、一部に欠陥が認められた。
×：画像部濃度が大幅に低下し、画像部に欠陥した部分有り。
【０１１２】
【表１】

【０１１３】
（実施例９〜１６）
＜非還元糖含有のアルカリ現像処理液の調製＞
非還元糖と塩基とを組合わせた、Ｄ−ソルビット／酸化カリウムＫ₂ＯよりなるＤ−ソルビットカリウム塩５．０％水溶液１Ｌに各種界面活性剤を下記表２に記載の量添加し、本発明のアルカリ現像処理液（９）〜（１６）を作製した。又、非還元糖と塩基とを組合わせたＤ−ソルビット／酸化カリウムＫ₂ＯよりなるＤ−ソルビットカリウム塩６．５％水溶液１Ｌに各種界面活性剤を下記表２に記載の量添加し、本発明のアルカリ現像補充液（９）〜（１６）を作製した。
【０１１４】
この非還元糖含有のアルカリ現像処理液を用いて、実施例１と同様に製版処理を行ない、実施例１と同様の評価を行った。結果を下記表２に示す。
【０１１５】
【表２】

【０１１６】
表１及び表２より明らかなように、界面活性剤濃度の高いアルカリ現像補充液を補充しながら現像処理する本発明の方法によれば、ＳｉＯ₂含有及び非還元糖含有のいずれの現像液においても十分な現像液処理性を維持しながら、画像部／非画像部のバランスの良好な安定した現像を連続的に行なうことができた。
【０１１７】
【発明の効果】
本発明によれば、アルカリ現像処理液の液性条件を維持しつつ、現像時における画像部／非画像部のバランスを良好にするとともに、その経時的な低下を防止し、長期間安定に現像することのできる平版印刷版の製版方法を提供することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plate making method of a so-called direct plate-making lithographic printing plate that can be directly made by infrared laser scanning based on a digital signal from a computer or the like.
[0002]
[Prior art]
In recent years, the development of lasers has been remarkable. Especially, solid lasers and semiconductor lasers that have a light emitting region from near infrared to infrared are easily available in high output and small size. These lasers are very useful as exposure light sources for plate-making systems.
[0003]
As an image recording material suitable for laser writing, for example, JP-A-7-285275 discloses a binder such as a cresol resin, a substance that absorbs light and generates heat, and a thermal decomposition such as quinonediazide. And a positive-type image recording material containing a compound that can substantially reduce the solubility of the binder in a state before decomposition.
This is a substance that absorbs light and generates heat in the exposed part due to infrared irradiation, and makes the exposed part alkali-soluble (heat mode type). Therefore, the thermal efficiency is low, and the solubility in an alkali developing solution in the development process is not satisfactory. For this reason, the alkali concentration of a developing solution was raised and the solubility of the exposed part has been ensured.
[0004]
However, the heat mode type lithographic printing original plate has low resistance to dissolution in the alkaline developing solution in the image area under the high concentration alkali conditions as described above, and the image recording material surface has only slight scratches. There was a problem that it was dissolved, and defects such as fine lines were likely to occur.
For this reason, as a method for improving developability, that is, solubility of an exposed portion while improving dissolution resistance of an unexposed portion, a surfactant, a chelating agent, or the like is added to an alkali developing solution to obtain an image portion. There has been proposed a method for improving the balance between the image area and the non-image area, such as suppressing dissolution of the resin and promoting developability in the non-image area. According to this method, although a certain degree of improvement is seen, when the development processing is continued continuously, the binder polymer or infrared absorbing dye constituting the photosensitive layer is eluted in the processing solution, and the eluted infrared absorber is eluted. Phenomenon such as formation of insoluble matter due to interaction with binder polymer components and inorganic substances in water, etc., and the eluate and precipitated unwanted matter hinder the influence of the additive, There have been problems such as poor developability and poor balance between image areas / non-image areas.
In order to maintain the development performance, a method of increasing the alkali concentration of the replenisher has been conventionally performed. In particular, the heat mode type lithographic printing plate precursor as described above has a large influence on the image area due to the alkali concentration. Therefore, it was difficult to obtain good developability.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention improves the balance between the image area and the non-image area at the time of development while maintaining the liquid property of the alkali developing solution, and prevents the deterioration with time, and stably develops for a long time. An object of the present invention is to provide a plate making method of a lithographic printing plate that can be used.
[0006]
[Means for Solving the Problems]
In carrying out continuous plate-making processing, the present inventors have developed an alkali concentration (hydroxide ion concentration) and SiO 2 in an alkali developing solution.₂As a result of intensive studies on components that can maintain the liquidity conditions suitable for development, such as density balance, and maintain a good balance between the image area and the non-image area, the additives contained in the replenisher are adjusted. As a result, it was found that fluctuations in developability over time can be prevented and good plate making can be performed for a long period of time, and the present invention has been completed.
[0007]
  That is, the lithographic printing plate making method is a lithographic printing plate making method in which a lithographic printing plate having an image forming layer containing an infrared absorber is exposed imagewise by infrared irradiation and then developed with an alkali developing solution. The surfactant concentration in the alkaline developer replenisher as a working solution is higher than the surfactant concentration in the alkali developer,In particular,Its concentration is3 to 15 timesIt is characterized by being.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The alkali developing solution that can be used in the plate making method of the lithographic printing plate of the present invention is not particularly limited, and the basic prescription is that a known alkali developing solution is used and a predetermined amount of surfactant is added. Is. Such a developer can be applied to the development of any lithographic printing plate having a recording layer for recording in the heat mode.
[0009]
First, an alkali developing solution used for developing a lithographic printing plate will be described.
An alkali developing solution (hereinafter, simply referred to as “developing solution”) used in the developing process is an alkaline aqueous solution, and can be appropriately selected from conventionally known alkaline aqueous solutions.
Examples of the alkaline aqueous solution include a developer composed of an alkali silicate or non-reducing sugar and a base, and those having a pH of 12.5 to 13.5 are particularly preferable.
The alkali silicate exhibits alkalinity when dissolved in water, and examples thereof include alkali metal silicates such as sodium silicate, potassium silicate and lithium silicate, and ammonium silicate.
The alkali silicate may be used alone or in combination of two or more.
[0010]
The alkaline aqueous solution is a silicon oxide SiO which is a component of silicate.₂And alkali oxide M₂The developability can be easily adjusted by adjusting the mixing ratio and concentration with O (M represents an alkali metal or ammonium group).
Among the alkaline aqueous solutions, the silicon oxide SiO₂And alkali oxide M₂Mixing ratio with O (SiO₂/ M₂O: molar ratio) of 0.5 to 3.0 is preferable, and 1.0 to 2.0 is more preferable.
SiO₂/ M₂If O is less than 0.5, the alkali strength becomes stronger, and this may cause a harmful effect of etching a general-purpose aluminum plate or the like as a support for an original plate for lithographic printing. When it exceeds, developability may fall.
[0011]
The alkali silicate concentration in the developer is preferably 1 to 10% by weight, more preferably 3 to 8% by weight, and most preferably 4 to 7% by weight based on the weight of the aqueous alkali solution.
When the concentration is less than 1% by weight, developability and processing ability may be lowered. When the concentration is more than 10% by weight, it is easy to form precipitates and crystals, and the gel is further neutralized in the waste liquid. This may cause trouble in waste liquid treatment.
[0012]
In the developer comprising the non-reducing sugar and the base, the non-reducing sugar means a sugar that does not have reducibility because it does not have a free aldehyde group or ketone group, and trehalose in which reducing groups are bonded to each other. It is classified into type oligosaccharides, glycosides in which saccharide reducing groups and non-saccharides are combined, and sugar alcohols reduced by hydrogenation of saccharides. In the present invention, any of these can be preferably used.
[0013]
Examples of the trehalose type oligosaccharide include saccharose and trehalose. Examples of the glycoside include alkyl glycosides, phenol glycosides, mustard oil glycosides, and the like.
Examples of the sugar alcohol include D, L-arabit, rebit, xylit, D, L-sorbit, D, L-annit, D, L-exit, D, L-talit, zulsiit, allozulcit and the like.
Furthermore, maltitol obtained by hydrogenation of a disaccharide, a reduced form (reduced water candy) obtained by hydrogenation of an oligosaccharide, and the like can also be suitably exemplified.
[0014]
Among the above, sugar alcohol and saccharose are preferable as the non-reducing sugar, and among them, D-sorbit, saccharose, and reduced syrup are more preferable because they have a buffering action in an appropriate pH region.
These non-reducing sugars may be used alone or in combination of two or more. The proportion of the non-reducing sugar in the developer is preferably from 0.1 to 30% by weight, more preferably from 1 to 20% by weight.
[0015]
In the alkali silicate or non-reducing sugar, an alkali agent as a base can be appropriately selected from conventionally known compounds and combined.
Examples of the alkaline agent include sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, Inorganic alkaline agents such as sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium borate, potassium borate, ammonium borate, potassium citrate, tripotassium citrate, sodium citrate Etc.
[0016]
Furthermore, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanol Organic alkali agents such as amicin, ethyleneimine, ethylenediamine, pyridine and the like can also be suitably exemplified.
These alkali agents may be used alone or in combination of two or more.
[0017]
Of these, sodium hydroxide and potassium hydroxide are preferable. The reason is that the pH can be adjusted in a wide pH range by adjusting the amount added to the non-reducing sugar. Further, trisodium phosphate, tripotassium phosphate, sodium carbonate, potassium carbonate and the like are preferable because they themselves have a buffering action.
[0018]
It is necessary to add a surfactant to the alkaline aqueous solution (developer) as described above. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.
Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, Sorbitan fatty acid partial ester, pentaerythritol fatty acid partial ester, propylene glycol mono fatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester , Polyglycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, fat Acid diethanol amides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides and the like are preferably exemplified.
Examples of the anionic surfactant include fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid ester salts, α-olefin sulfonic acid salts, linear alkylbenzene sulfonic acid salts, branched chain Alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, disodium N-alkylsulfosuccinate monoamide Salts, petroleum sulfonates, sulfated beef tallow oil, sulfates of fatty acid alkyl esters, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fats Monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates Preferable examples include salts, partially saponified products of styrene / maleic anhydride copolymer, partially saponified products of olefin / maleic anhydride copolymer, and naphthalene sulfonate formalin condensates.
Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts such as tetrabutylammonium bromide, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.
Examples of amphoteric surfactants include carboxybetaines, alkylaminocarboxylic acids, sulfobetaines, aminosulfuric acid esters, imidazolines, and the like.
Among the above surfactants, those having “polyoxyethylene” can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene and polyoxybutylene, and these are also included in the surfactant. The
[0019]
  The concentration of the surfactant in the developer is preferably 0.001 to 10% by weight, more preferably 0.005 to 1% by weight, and most preferably 0.01 to 0.5% by weight.
  The alkaline developer replenisher used in the plate making method of the present invention means a working solution, and when the developer replenisher is prepared, there are no particular restrictions on the active ingredients and optional ingredients other than the surfactant. , The same composition as the alkali developing solution may be used, and the alkali concentration and mixing ratio (SiO₂/ M₂O) or the like may be prepared, but it is necessary that the concentration of the surfactant be higher than that of the developing solution, and preferablyIs 3~ 15 times the amount.
  When the concentration of the surfactant is equal to or less than the concentration of the base alkali development processing solution, the effect of suppressing dissolution of the unexposed portion is deteriorated. When this surfactant concentration is 1.2 times or more of the treatment liquid, the effect of improving the surfactant concentration becomes remarkable, and even if the concentration is increased by more than 50 times, the effect is not improved, On the contrary, the developability of the exposed area may deteriorate, which is not preferable.
[0020]
In the method of the present invention, the use of a replenisher having a high surfactant concentration reduces the function of the surfactant for maintaining the balance of developability due to the insoluble matter and the elution of the active ingredient. In addition, since a certain function can always be exhibited, plate making with good development performance and a good balance between the image area and the non-image area can be performed stably over a long period of time.
Further, as the replenisher, not only a surfactant but also an aqueous solution having a high alkali strength in which the content of a component having a higher alkali concentration than the developer for development as described above is also increased can be used. . However, in this case, as described above, in consideration of the alkali aqueous solution solubility of the lithographic printing plate precursor, a range that does not affect fine image portions such as undesired fine lines and halftone dots should be selected. .
Replenishment may be performed at regular intervals after passing through the plate. The replenishment amount is a number obtained by dividing the total replenishment amount by the treatment amount, and is 20 ml / m.²~ 500ml / m²A range of is used.
[0021]
The following additives can be added to the alkali developing solution and replenisher of the present invention for the purpose of further improving the developing performance.
For example, neutral salts such as NaCl, KCl and KBr described in JP-A-58-75152, chelating agents such as EDTA and NTA described in JP-A-58-190952, JP-A-59- [Co (NH_Three)₆] Cl_ThreeCoCl₂・ 6H₂Complexes such as O, alkyl naphthalene sulfonic acid soda described in JP-A-50-51324, and cation such as methyl chloride quaternized product of p-dimethylaminomethylpolystyrene described in JP-A-55-95946 Nick polymer,
[0022]
Amphoteric polymer electrolytes such as vinylbenzyltrimethylammonium chloride and sodium acrylate copolymer described in JP-A-56-142528, reduction of sodium sulfite, etc. described in JP-A-57-192951 Inorganic salts, inorganic lithium compounds such as lithium chloride described in JP-A-58-59444, organic boron compounds described in JP-A-59-84241, and the like.
[0023]
Various organic solvents and the like can be added to the developer and replenisher as necessary for the purpose of promoting and suppressing developability, dispersing development residue, and improving the ink affinity of the printing plate image area. .
As the organic solvent, benzyl alcohol and the like are preferable.
[0024]
Furthermore, if necessary, an inorganic salt reducing agent such as hydroquinone, resorcin, sulfurous acid or sodium salt or potassium salt of bisulfite, organic carboxylic acid, antifoaming agent, and hard water softening agent may be added.
[0025]
The plate-making method of the lithographic printing plate of the present invention is most suitable for the development processing of a lithographic printing original plate having an infrared laser-sensitive image forming layer, which will be described later, but an image containing an o-quinonediazide compound that has been widely used conventionally. The present invention can also be suitably applied to development processing of an image recording material having a formation layer.
[0026]
Next, a method for making a lithographic printing plate using the developing solution of the present invention will be described. The plate making method of the lithographic printing plate of the present invention comprises a step of imagewise exposure to a lithographic printing original plate provided with an image forming layer containing at least an infrared absorber by infrared irradiation, and an alkali development of the exposed lithographic printing original plate And developing with a processing solution, and controlling the amount of the surfactant contained in the alkaline developer replenisher added when the developing step is continuously performed in the developing machine.
In the plate making method of the present invention, a lithographic printing original plate in which an image forming layer containing at least an infrared absorber is formed on a support is used as the lithographic printing original plate. When a desired image is exposed by means such as irradiating an infrared laser based on the data, the laser light is efficiently absorbed by the infrared absorber contained in the image forming layer and converted into heat, and the image is processed through the following process. It is formed.
That is, in the case of a positive type lithographic printing original plate, only the exposed portion generates heat due to accumulation of absorbed energy due to exposure and becomes soluble in alkali water, and only the exposed portion is removed by development processing using an alkali developing solution. In the case of a negative type lithographic printing original plate, a cross-linking agent coexisting with the acid is generated when only the exposed part generates heat due to the accumulation of absorbed energy due to exposure and an acid is generated by the heat. Causes a cross-linking reaction, and only the exposed portion becomes insoluble in alkali water to form an image, while the non-exposed portion is removed by a developing process using an alkaline developing solution to form a desired image.
In the plate making method of the present invention, as the alkali developing solution, a known lithographic printing plate alkali developing solution containing a surfactant, preferably a nonionic surfactant is used.
[0027]
For example, in the development processing of a positive type lithographic printing plate, only the exposed portion generates heat due to accumulation of absorbed energy due to exposure and becomes soluble in alkaline water. However, when a strong alkaline aqueous solution is used as the development processing solution, it is used in the present invention. As described above, the image forming layer containing an infrared absorber capable of heat mode recording is slightly inferior in alkali resistance, so that the peripheral portion of the image forming layer corresponding to the image portion in the vicinity of the exposed portion, a portion where slight scratches have occurred, etc. However, there is a possibility that the non-image area (exposed area) and the alkaline developing solution may be removed. By using the surfactant according to the present invention, the developability of the alkaline developing solution is suppressed in a well-balanced manner, and a plate-making process with a good balance between the image part / non-image part can be performed. This is particularly useful when applied to the development processing of a positive planographic printing plate.
[0028]
In recent years, particularly in the plate making / printing industry, automatic developing machines that continuously process printing plate materials have been widely used in order to rationalize and standardize plate making operations.
This automatic developing machine is generally composed of a developing unit and a post-processing unit, and includes an apparatus for conveying a printing plate material, processing liquid tanks and a spray device. Each processing liquid pumped up is sprayed from a spray nozzle for development processing. In addition, recently, a method is also known 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 is processed while being supplemented with a replenisher according to the processing amount, operating time, and the like.
[0029]
In the present invention, an alkaline aqueous solution having a higher surfactant concentration than the developer is added to the developer as a replenisher, so that a large amount of images can be obtained under stable conditions without changing the developer in the developer tank for a long time. The forming material can be processed.
[0030]
The lithographic printing plate developed using the alkaline developing solution and replenisher of the present invention is subjected to post-treatment with a rinsing solution containing washing water, a surfactant, etc., a desensitizing solution containing gum arabic or a starch derivative. Made. In this post-treatment, these treatment liquids can be variously combined.
[0031]
Next, the lithographic printing original plate used in the lithographic printing plate making method of the present invention will be described.
The lithographic printing plate precursor has an image forming layer on a support, and further includes another layer as necessary. The image forming layer contains (A) an infrared absorber, and at least (B) The alkali-soluble polymer compound and (C) the alkali-soluble polymer compound are mixed with each other to reduce the solubility of the alkali-soluble polymer compound in an alkaline aqueous solution, and the solubility-reducing action is reduced by heating. Consists of compounds. In the case of a negative type lithographic printing original plate, the exposed portion is cured to form an image portion. Therefore, the image forming layer is further crosslinked with (D) a compound that generates an acid by heat and (E) an acid. It contains a crosslinking agent. Below, each component is demonstrated easily.
[0032]
-(A) Infrared absorber-
An infrared absorber (hereinafter, also referred to as “component (A)”) has a function of converting absorbed infrared rays into heat.
As an infrared absorber that can be used in the present invention, a dye or pigment capable of efficiently absorbing infrared rays in a wavelength region of 700 nm or more, preferably in a wavelength region of 750 nm to 1200 nm is preferable, and in a wavelength region of 760 nm to 1200 nm. A dye or pigment having an absorption maximum is more preferred.
[0033]
Examples of the dye include commercially available dyes and known dyes described in the literature (for example, “Dye Handbook”, edited by the Society for Synthetic Organic Chemistry, published in 1970), such as azo dyes, metal complex azo dyes, and pyrazolone azo dyes. Examples thereof include dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, and the like.
[0034]
Among them, for example, cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, JP-A-58-173696, Methine dyes described in JP-A-58-181690, JP-A-58-194595, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59 Naphthoquinone dyes described in JP-A-60-73996, JP-A-60-52940, JP-A-60-63744, etc., squarylium dyes described in JP-A-58-112792, etc., described in British Patent 434,875 Preferable examples include cyanine dyes, dihydroperimidine squarylium dyes described in US Pat. No. 5,380,635, and the like.
[0035]
Also preferred are near infrared absorption sensitizers described in US Pat. No. 5,156,938, substituted arylbenzo (thio) pyrylium salts 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, JP-A-58-2220143, JP-A-59-41363, 59-84248, 59-84249, 59-146063, 59-146061, pyrylium compounds described in JP-A-59-216146, cyanine dyes described in US Pat. No. 4,283, As a commercially available product, a pyrylium compound described in JP-B-5-13514 and JP-5-19702, such as a pentamethine thiopyrylium salt described in the specification of No. 475 , Epolight III-178, Epolight III-130, Epolight III-125, Epolight IV-62A (manufactured by Eporin Co.) are also preferable.
[0036]
Further, near infrared absorbing dyes represented by the formulas (I) and (II) described in U.S. Pat. No. 4,756,993 can also be mentioned as suitable.
Of the above, cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes are more preferred.
[0037]
Examples of the pigment include a commercially available pigment or color index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), “ Examples of pigments described in “Printing Ink Technology” (CMC Publishing, 1984) include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, and metals. Examples thereof include powder pigments and other polymer-bound dyes.
[0038]
Specifically, for example, 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, isoindolinones Pigments, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like.
Among these, carbon black is preferable.
[0039]
The pigment may be used without being subjected to surface treatment or may be used after being subjected to surface treatment.
Surface treatment methods include 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. Is mentioned. These surface treatment methods are described in "Characteristics and Applications of Metal Soap" (Sachishobo), "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986). ing.
[0040]
The particle diameter of the pigment is preferably 0.01 μm to 10 μm, more preferably 0.05 μm to 1 μm, and most preferably 0.1 μm to 1 μm.
When the particle size is less than 0.01 μm, the stability of the dispersion may be deteriorated when a dispersion such as a photosensitive layer coating solution is prepared. When the particle size exceeds 10 μm, the uniformity of the image forming layer may be deteriorated. May get worse.
[0041]
The method for dispersing the pigment can be appropriately selected from known dispersion techniques such as a general-purpose disperser for ink production or toner production.
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 thereof are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).
[0042]
The content of the dye or pigment is preferably 0.01 to 50% by weight, more preferably 0.1 to 10% by weight, more preferably 0.1 to 10% by weight, based on the total solid weight of the image forming layer. 0.5-10% by weight is most preferred, and in the case of pigments, 3.1-10% by weight is most preferred.
When the content is less than 0.01% by weight, the sensitivity may be lowered, and when it exceeds 50% by weight, the uniformity of the image forming layer may be lowered and the durability thereof may be deteriorated.
[0043]
The dye or pigment may be added to the same layer as other components, or a separate layer may be provided and added thereto. When setting it as another layer, it is preferable to add to the layer adjacent to the layer containing the below-mentioned (C) component.
The dye or pigment and the alkali-soluble polymer compound are preferably contained in the same layer, but may be contained in separate layers.
[0044]
-(B) Alkali-soluble polymer compound-
As the alkali-soluble polymer compound (hereinafter sometimes referred to as “component (B)”) that can be used in the present invention, the following (1) to (3) acidic groups have a main chain and / or side chain structure. An alkaline water-soluble polymer compound contained therein can be used.
(1) Phenol group (-Ar-OH)
(2) Sulfonamide group (—SO₂NH-R)
(3) Substituted sulfonamide acid group (hereinafter referred to as “active imide group”)
[-SO₂NHCOR, -SO₂NHSO₂R, -CONHSO₂R]
In (1) to (3), Ar represents a divalent aryl linking group which may have a substituent, and R represents a hydrocarbon group which may have a substituent.
Specific examples thereof are shown below, but the present invention is not limited thereto.
[0045]
(1) Examples of the alkali-soluble polymer compound having a phenol group include a condensation polymer of phenol and formaldehyde, a condensation polymer of m-cresol and formaldehyde, a condensation polymer of p-cresol and formaldehyde, m- / P-mixed cresol and formaldehyde condensation polymer, phenol and cresol (any of m-, p- or m- / p-mixing) and formaldehyde condensation polymer or the like novolak resin or pyrogallol and acetone And a polycondensation polymer. Furthermore, the high molecular compound which polymerized the monomer which has a phenol group in a side chain can also be mentioned.
[0046]
As the polymer compound having a phenolic hydroxyl group in the side chain, a polymerizable monomer comprising a low molecular weight compound having at least one unsaturated bond polymerizable with the phenolic hydroxyl group is homopolymerized or other than the polymerizable monomer And a polymer compound obtained by copolymerizing the polymerizable monomer.
Examples of the monomer having a phenol group in the side chain include acrylamide, methacrylamide, acrylate ester, methacrylate ester or hydroxystyrene having a phenol group in the side chain.
[0047]
Specifically, N- (2-hydroxyphenyl) acrylamide, N- (3-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) acrylamide, N- (2-hydroxyphenyl) methacrylamide, N- (3 -Hydroxyphenyl) methacrylamide, N- (4-hydroxyphenyl) methacrylamide, o-hydroxyphenyl acrylate, m-hydroxyphenyl acrylate, p-hydroxyphenyl acrylate, o-hydroxyphenyl methacrylate, m-hydroxyphenyl methacrylate, p- Hydroxyphenyl methacrylate, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (2-hydroxyphenyl) ethyl acrylate, 2- (3-hydroxyphenyl) Preferred are ethyl acrylate, 2- (4-hydroxyphenyl) ethyl acrylate, 2- (2-hydroxyphenyl) ethyl methacrylate, 2- (3-hydroxyphenyl) ethyl methacrylate, 2- (4-hydroxyphenyl) ethyl methacrylate, and the like. Can be mentioned.
[0048]
The weight average molecular weight of the alkali-soluble polymer compound having a phenol group is 5.0 × 10.²~ 2.0 × 10^FiveThe number average molecular weight is 2.0 × 10²~ 1.0 × 10^FiveAre preferable from the viewpoint of image formability.
[0049]
Moreover, the alkali-soluble polymer compound having a phenol group may be used alone or in combination of two or more. In the case of the combination, a carbon number of 3 to 8 such as a condensation polymer of t-butylphenol and formaldehyde or a condensation polymer of octylphenol and formaldehyde as described in US Pat. No. 4,123,279 is used. A condensation polymer of phenol and formaldehyde having the above alkyl group as a substituent may be used in combination.
These condensation polymers also have a weight average molecular weight of 5.0 × 10²~ 2.0 × 10^FiveThe number average molecular weight is 2.0 × 10²~ 1.0 × 10^FiveAre preferred.
[0050]
(2) Examples of the alkali-soluble polymer compound having a sulfonamide group include, for example, a polymer having a compound having a sulfonamide group as a main monomer constituent unit, that is, a homopolymer or another polymerizable monomer in the monomer constituent unit. And a copolymer obtained by copolymerizing.
The polymerizable monomer having a sulfonamide group includes at least one sulfonamide group —SO 2 —NH— in which at least one hydrogen atom is bonded to a nitrogen atom and one polymerizable unsaturated bond in one molecule. And a monomer composed of a low molecular weight compound. Among them, a low molecular compound having an acryloyl group, an allyl group or a vinyloxy group and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group is preferable.
Examples of the low molecular weight compound include compounds represented by the following general formulas (a) to (e), but the present invention is not limited thereto.
[0051]
[Chemical 1]

[0052]
Where X¹, X²Each independently represents an oxygen atom or NR⁷Represents. R¹, R^FourAre each independently a hydrogen atom or CH_ThreeRepresents. R², R^Five, R⁹, R¹², R¹⁶Each independently represents a C 1-12 alkylene group, cycloalkylene group, arylene group or aralkylene group which may have a substituent. R^Three, R⁷, R¹³Each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, a cycloalkyl group, an aryl group or an aralkyl group. R⁶, R¹⁷Represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group that may each independently have a substituent. R⁸, R^Ten, R¹⁴Are each independently a hydrogen atom or CH_ThreeRepresents. R¹¹, R¹⁵Each independently represents a C1-C12 alkylene group, cycloalkylene group, arylene group or aralkylene group which may have a single bond or a substituent. Y¹, Y²Each independently represents a single bond or CO.
[0053]
Among these, m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be suitably used.
[0054]
(3) Examples of the alkali-soluble polymer compound having an active imide group include a polymer having a compound having an active imide group as a main monomer constituent unit.
As a polymer having a compound having an active imide group as a main monomer structural unit, a low molecular compound having at least one active imide group represented by the following formula and one or more polymerizable unsaturated bonds in one molecule. And a high molecular compound obtained by homopolymerizing the above monomer or copolymerizing the monomer with another polymerizable monomer.
[0055]
[Chemical 2]

[0056]
Specific examples of such a compound include N- (p-toluenesulfonyl) methacrylamide, N- (p-toluenesulfonyl) acrylamide and the like.
[0057]
In addition to the above, a polymer compound obtained by polymerizing any two or more of the polymerizable monomer having a phenol group, the polymerizable monomer having a sulfonamide group, and the polymerizable monomer having an active imide group, or Also preferred are polymer compounds obtained by further copolymerizing these two or more polymerizable monomers with another polymerizable monomer.
[0058]
Compounding ratio in the case of copolymerizing the polymerizable monomer (M1) having a sulfonamide group and / or the polymerizable monomer (M3) having an active imide group with the polymerizable monomer (M1) having a phenol group (M1: M2 and (Or M3; weight ratio) is preferably 50:50 to 5:95, and more preferably 40:60 to 10:90.
[0059]
When the alkali-soluble polymer compound is a copolymer composed of a monomer constituent unit having any one selected from the acidic groups (1) to (3) and a constituent unit of another polymerizable monomer, The copolymer preferably contains 10 mol% or more, more preferably 20 mol% or more of a monomer structural unit having any one selected from the acidic groups (1) to (3).
When the content of the monomer constituent unit is less than 10 mol%, sufficient alkali solubility may not be obtained, and the development latitude may be narrowed.
[0060]
As a method for synthesizing the copolymer, conventionally known graft copolymerization method, block copolymerization method, random copolymerization method and the like can be used.
[0061]
Examples of other polymerizable monomers that are copolymerized with a polymerizable monomer having a monomer having any one selected from the acidic groups (1) to (3) as the structural unit include the following (a) to (l): Although the monomer to mention can be mentioned, in this invention, it is not limited to these.
[0062]
(A) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(B) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl Alkyl acrylates such as acrylates;
(C) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl Alkyl methacrylate such as methacrylate.
[0063]
(D) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide.
(E) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(F) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(G) Styrenes such as styrene, α-methylstyrene, methylstyrene, and chloromethylstyrene.
[0064]
(H) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(I) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.
(J) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like.
(K) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.
(L) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic acid.
[0065]
The alkali water-soluble polymer compound is preferably a compound having a weight average molecular weight of 2000 or more and a number average molecular weight of 500 or more, and a weight average molecular weight of 5000, regardless of whether it is a homopolymer or a copolymer. More preferred are those having a molecular weight of ˜300000, a number average molecular weight of 800 to 250,000 and a dispersity (weight average molecular weight / number average molecular weight) of 1.1 to 10.
When the alkali-soluble polymer compound is a phenol-formaldehyde resin, a cresol-aldehyde resin, or the like, it is preferable that the weight average molecular weight is 500 to 20000 and the number average molecular weight is 200 to 10,000.
[0066]
The content of the alkaline water-soluble polymer compound is preferably 30 to 99% by weight, more preferably 40 to 95% by weight, and most preferably 50 to 90% by weight based on the total solid content of the image forming layer.
When the content is less than 30% by weight, the durability of the image forming layer may be lowered, and when it exceeds 99% by weight, the sensitivity and the durability may be lowered.
Moreover, the said high molecular compound may use only 1 type, or may use it in combination of 2 or more types.
[0067]
-(C) a compound that is dissolved in the alkali-soluble polymer compound to reduce the solubility of the alkali-soluble polymer compound in an alkaline aqueous solution, and whose solubility-reducing action is reduced by heating-
This component (C) has a good compatibility with the (B) alkali-soluble polymer compound due to the action of a hydrogen-bonding functional group present in the molecule, and forms a uniform coating solution for an image forming layer. In addition, it refers to a compound having a function of suppressing alkali solubility (solubility suppressing action) of the alkali-soluble polymer compound by interaction with the alkali-soluble polymer compound.
[0068]
In addition, the above-described solubility-inhibiting action on the alkali-soluble polymer compound disappears by heating, but when this infrared absorber itself is a compound that decomposes by heating, sufficient energy for decomposition can be obtained, such as laser output and irradiation time. If it is not given according to these conditions, the solubility-inhibiting action of the alkali-soluble polymer compound cannot be sufficiently lowered, and the sensitivity may be lowered. For this reason, as a thermal decomposition temperature of (C) component, 150 degreeC or more is preferable.
[0069]
As the component (C), considering the interaction with the alkali-soluble polymer compound (B), for example, it interacts with the alkali-soluble polymer compound such as a sulfone compound, ammonium salt, phosphonium salt, amide compound, etc. Can be suitably selected from the possible compounds.
In particular, for example, when a novolak resin is used alone as the component (B), the “(A + C) component” described later is preferable, and the cyanine dye A exemplified below is more preferable. The component (A + C) will be described later.
[0070]
In general, the blending ratio (C / B) of the component (C) and the alkali-soluble polymer compound (B) is preferably 1/99 to 25/75.
When the mixing ratio is less than 1/99, that is, the amount of the component (C) is too small, the interaction with the alkali-soluble polymer compound becomes insufficient, so that the alkali solubility cannot be lowered and good image formation is achieved. If it exceeds 25/75, that is, if the component (C) is too much, the interaction may be excessive and the sensitivity may be significantly reduced.
[0071]
-(A + C) component-
In this invention, it can replace with the said (A) component and (C) component, and can use the compound ((A + C) component) which has both these characteristics.
The component (A + C) has the property of absorbing light and generating heat (that is, the characteristics of the component (A)), has an absorption region in the wavelength region of 700 to 1200 nm, and is further an alkali-soluble polymer. It is a basic dye that is compatible with the compound.
Since the component (A + C) has a group that interacts with an alkali-soluble polymer compound such as an ammonium group or an iminium group in its molecule (that is, the characteristics of the component (C)), it interacts with the polymer compound. The alkali solubility can be suppressed.
As said (A + C) component, the compound represented by the following general formula (Z) can be mentioned, for example.
[0072]
[Chemical Formula 3]

[0073]
In the general formula (Z), R^{twenty one}~ R^{twenty four}Each independently represents a hydrogen atom or an optionally substituted alkyl group having 1 to 12 carbon atoms, an alkenyl group, an alkoxy group, a cycloalkyl group, an aryl group, and R^{twenty one}And R^{twenty two}, R^{twenty three}And R^{twenty four}May be bonded to each other to form a ring structure.
R^{twenty one}~ R^{twenty four}Examples include a hydrogen atom, a methyl group, an ethyl group, a phenyl group, a dodecyl group, a naphthyl group, a vinyl group, an allyl group, and a cyclohexyl group, and these groups may further have a substituent. Good. Here, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxyl group, a carbonic acid ester, and a sulfonic acid ester.
[0074]
Where R^{twenty five}~ R³⁰Each independently represents an alkyl group having 1 to 12 carbon atoms which may have a substituent, and the R^{twenty five}~ R³⁰Examples thereof include a methyl group, an ethyl group, a phenyl group, a dodecyl group, a naphthyl group, a vinyl group, an allyl group, and a cyclohexyl group, and these groups may further have a substituent. Here, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxyl group, a carboxylic acid ester, and a sulfonic acid ester.
[0075]
Where R³¹~ R³³Each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 8 carbon atoms which may have a substituent;³²R³¹Or R³³To form a ring structure, and when m> 2, a plurality of R³²They may be bonded to each other to form a ring structure.
R³¹~ R³³As, for example, chlorine atom, cyclohexyl group, R³²Examples thereof include a cyclopentyl ring and a cyclohexyl ring formed by bonding each other, and these groups may further have a substituent. Here, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxyl group, a carboxylic acid ester, and a sulfonic acid ester.
Moreover, m represents the integer of 1-8, and 1-3 are preferable especially.
[0076]
Where R³⁴~ R³⁵Each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 8 carbon atoms which may have a substituent;³⁴Is R³⁵To form a ring structure, and when m> 2, a plurality of R³⁴They may be bonded to each other to form a ring structure.
R³⁴~ R³⁵As, for example, chlorine atom, cyclohexyl group, R³⁴Examples thereof include a cyclopentyl ring and a cyclohexyl ring formed by bonding each other, and these groups may further have a substituent. Here, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxyl group, a carboxylic acid ester, and a sulfonic acid ester.
Moreover, m represents the integer of 1-8, and 1-3 are preferable especially.
[0077]
In the formula, X- represents an anion, for example, perchloric acid, tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-O-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfone Examples include acid, 1-naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and paratoluenesulfonic acid.
Of these, alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, and 2,5-dimethylbenzenesulfonic acid are preferable.
[0078]
The compound represented by the general formula (Z) is a compound generally referred to as a cyanine dye, and specifically, the following compounds are preferably used. However, the present invention is not limited thereto. .
[0079]
[Formula 4]

[0080]
When the component (A + C) having both of these properties is used in place of the component (A) and the component (C) described above, the usage ratio of the component (A + C) to the component (B) [(A + C) / (B)] is preferably 1/99 to 30/70, more preferably 1/99 to 25/75.
[0081]
The following are the components that constitute the recording layer of the negative lithographic printing plate.
-(D) Compound that generates acid by heat-
When the image forming material of the present invention is a negative type, a compound that generates an acid upon heating (hereinafter referred to as “acid generator”) is used in combination. This acid generator refers to a compound that decomposes when heated to 100 ° C. or higher to generate an acid. 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 include those described in Japanese Patent Application No. 11-66733.
[0082]
The addition amount of the acid generator is preferably 0.01 to 50% by weight, more preferably 0.1 to 40% by weight, and most preferably 0.5 to 30% by weight based on the total solid weight of the image forming layer. preferable.
[0083]
-(E) Crosslinker that crosslinks with acid-
When the lithographic printing original plate of the present invention is a negative type, a crosslinking agent that is crosslinked by an acid (hereinafter sometimes simply referred to as “crosslinking agent”) is used in combination.
Examples of the crosslinking agent include the following.
(I) Aromatic compound substituted with alkoxymethyl group or hydroxymethyl group (ii) Compound having N-hydroxymethyl group, N-alkoxymethyl group or N-acyloxymethyl group
(Iii) Epoxy compound
Furthermore, the thing as described in Japanese Patent Application No. 10-53788, a phenol derivative, etc. can be mentioned.
[0084]
The addition amount of the crosslinking agent is preferably 5 to 80% by weight, more preferably 10 to 75% by weight, and most preferably 20 to 70% by weight based on the total solid content of the image forming layer.
When the phenol derivative is used as a crosslinking agent, the addition amount of the phenol derivative is preferably 5 to 70% by weight, more preferably 10 to 50% by weight based on the total solid content of the image forming material.
Details of the above-mentioned various compounds are described in Japanese Patent Application No. 11-66733.
[0085]
-Other ingredients-
Various additives can be further added to the image forming layer of the lithographic printing plate precursor suitable for applying the alkali developing solution of the present invention, if necessary.
For example, for the purpose of improving sensitivity, known additives such as cyclic acid anhydrides, phenols, organic acids, and sulfonyl compounds can be used in combination.
The addition amount of the other cyclic acid anhydrides, phenols, organic acids or sulfonyl compounds is preferably 0.05 to 20% by weight, preferably 0.1 to 15% by weight based on the total solid weight of the image forming layer. % Is more preferable, and 0.1 to 10% by weight is most preferable.
[0086]
Further, for the purpose of expanding the stability of processability with respect to development conditions, nonionic surfactants described in JP-A-62-251740, JP-A-3-208514, etc., JP-A-59-121044, Amphoteric surfactants described in JP-A-4-13149 can be added.
The amount of the nonionic surfactant or amphoteric surfactant used is preferably 0.05 to 15% by weight, more preferably 0.1% by weight, based on the total solid weight of the image forming layer.
[0087]
The image forming layer can be added with a printing agent for obtaining a visible image immediately after heating by exposure or a dye or pigment as an image colorant.
Examples of the print-out agent include a combination of a compound that generates an acid upon heating by exposure and an organic dye that can form a salt.
Specifically, combinations of o-naphthoquinone diad-4-sulfonic acid halogenide and salt-forming organic dyes described in JP-A-50-36209 and JP-A-53-8128, As described in JP-A-53-36223, JP-A-54-74728, JP-A-60-3626, JP-A-61-143748, JP-A-61-151644, and JP-A-63-58440. And a combination of a trihalomethyl compound and a salt-forming organic dye.
Examples of the trihalomethyl compound include an oxazole compound and a triazine compound, both of which have excellent temporal stability and give clear printout images.
As the image colorant, for example, in addition to the salt-forming organic dye, other dyes can be used, and examples thereof include oil-soluble dyes and basic dyes.
[0088]
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 (above, Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (C.I. 42555), Methyl Violet (C.I. 42535), Ethyl Bio Red, Rhodamine B (C.I. 145170B), Malachite Green (C I.42000), methylene blue (C.I. 52015) and the like. The dyes described in JP-A-62-293247 are particularly preferred.
[0089]
The addition amount of the various dyes is preferably 0.01 to 10% by weight, more preferably 0.1 to 3% by weight, based on the total solid weight of the image forming layer.
[0090]
Moreover, a plasticizer and the following various additives can be added as needed for the purpose of imparting flexibility to the coating film.
For example, an onium salt, an o-quinonediazide compound, an aromatic sulfone compound, an aromatic sulfonic acid ester compound, or the like, which is a thermally decomposable compound that substantially reduces the solubility of the alkaline water-soluble polymer compound in an undecomposed state. Can be used together. The addition of the compound is preferable from the viewpoint of improving the ability to inhibit dissolution of the image area in the phenomenon liquid.
[0091]
The addition amount of the onium salt, o-quinonediazide compound, aromatic sulfonic acid ester and the like is preferably 0.1 to 50% by weight, and 0.5 to 30% by weight with respect to the total solid weight of the image forming layer. More preferred is 0.5 to 20% by weight.
[0092]
-Support-
Examples of the support for providing the image forming layer include a pure aluminum plate, an aluminum alloy plate, and a plastic film on which aluminum is laminated or deposited.
The surface of the aluminum plate is preferably subjected to a surface treatment such as graining, sodium silicate, potassium fluorinated zirconate, an aqueous solution such as phosphate, or an anodizing treatment.
Also, an aluminum plate described in US Pat. No. 2,714,066, which has been grained and then immersed in an aqueous sodium silicate solution, and an aluminum plate described in Japanese Patent Publication No. 47-5125 were anodized. Thereafter, an aluminum plate that has been dipped in an aqueous solution of an alkali metal silicate is also preferred.
[0093]
An original plate for lithographic printing can be prepared by applying an image forming layer as a photosensitive layer on a desired support, but before forming the image forming layer, an undercoat may be applied on the support, if necessary. Layers can also be provided.
Examples of the component used for the undercoat layer include various organic compounds. For example, phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, and 2-aminoethylphosphonic acid; phenyl optionally having a substituent Organic phosphonic acids such as phosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid; phenylphosphonic acid, naphthylphosphoric acid, alkylphosphoric acid and glyceroline which may have a substituent Organic phosphoric acid such as acid; organic phosphinic acid such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent; amino acids such as glycine and β-alanine; Has hydroxyl group such as hydrochloride Hydrochloride salts of amines.
[0094]
The dry coating amount of the undercoat layer is 2 to 200 mg / m.²Is preferably 5 to 100 mg / m²Is more preferable.
The dry coating amount is 2 mg / m²If it is less than 1, sufficient film properties may not be obtained. Meanwhile, 200 mg / m²Even if it is applied beyond the range, no further effect can be obtained.
[0095]
In general, the lithographic printing plate developed with the alkali developing solution of the present invention is generally used as an image-forming layer coating solution by dissolving the above-mentioned various components (the components (A) to (E) and other components) in a solvent. This is applied to a desired support.
Examples of the solvent 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, Examples include dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethyl glare, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, α-butyrolactone, and toluene. However, the present invention is not limited to these.
Moreover, the said solvent may be individual or may mix 2 or more types.
[0096]
The total solid concentration of various components (the components (A) to (E) and other components) in the solvent is preferably 1 to 50% by weight.
The dry coating amount (solid content) of the image forming layer that is applied and dried on the support is generally 0.5 to 5.0 g / m.²Is preferred.
[0097]
As a method of coating on the support, it can be appropriately selected from various known methods, for example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, grade coating, roll coating. Etc.
As the coating amount decreases, the apparent sensitivity increases, but the film properties of the image forming layer decrease.
[0098]
In the image forming layer coating solution, a surfactant, for example, a fluorosurfactant described in JP-A No. 62-170950 may be added for the purpose of improving coating properties. .
The addition amount is preferably 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the total solid weight of the image forming layer.
[0099]
The lithographic printing original plate of the present invention can be recorded by an infrared laser, and can also be recorded by an ultraviolet lamp or a thermal head.
As the infrared laser, a laser that emits infrared rays having a wavelength of 700 to 1200 nm is preferable, and a solid laser or a semiconductor laser that emits infrared rays in the same wavelength range is more preferable.
[0100]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not restrict | limited to these. In the examples, “%” represents “% by weight”.
[0101]
<Preparation of original plate for lithographic printing>
A 0.3 mm thick aluminum plate (material 1050) was washed with trichlorethylene and degreased, and then a nylon brush and 400 mesh pumice-water suspension were used to make the surface grainy and washed thoroughly with water.
After washing, this aluminum plate was etched by immersing it in a 25% aqueous sodium hydroxide solution at 45 ° C. for 9 seconds, washed with water, further immersed in a 20% nitric acid aqueous solution for 20 seconds, and washed again with water. The etching amount of the grained surface at this time is about 3 g / m.²Met.
[0102]
Next, the aluminum plate was treated with 7% sulfuric acid as an electrolyte, and the current density was 15 A / dm.²3 g / m for direct current²After the anodic oxide coating was provided, it was washed with water and dried.
This was treated with a 2.5% aqueous solution of sodium silicate at 30 ° C. for 10 seconds, the following undercoat layer coating solution was applied, and dried at 80 ° C. for 15 seconds to obtain a support. The dry coating amount of the undercoat layer after drying is 15 mg / m²Met.
[0103]
<Coating liquid for undercoat layer>
・ The following copolymer P (molecular weight 28000): 0.3 g
・ Methanol ・ ・ ・ 100g
・ Water 1g
[0104]
[Chemical formula 5]

[0105]
On the obtained support, the following image forming layer coating solution was dried at a coating amount of 1.8 g / m.²Then, a positive type lithographic printing original plate was obtained.
[0106]
<Coating liquid for image forming layer>
・ M, p-cresol novolak [component (B)] 1.0 g
(M / p ratio = 6/4, weight average molecular weight 8000,
0.5% unreacted cresol)
・ Cyanine dye A [component (A + C)] 0.1 g
・ Phthalic anhydride [component (D)] ・ ・ ・ 0.05g
・ P-Toluenesulfonic acid 0.002g
・ Ethyl violet 0.02g
(Counterion: 6-hydroxy-β-naphthalenesulfonic acid)
Naphthoquinone 1,2-diazide-5-sulfonyl chloride and
Esterified product with pyrogallol-acetone resin 0.01g
・ Fluorosurfactant: 0.05g
(Product name: MegaFuck F-177, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone ・ ・ ・ 8g
・ 1-methoxy-2-propanol 4g
[0107]
(Example 18)
<SiO₂Preparation of Contained Alkaline Developer Treatment Solution>
  Silicon oxide SiO₂And potassium oxide K₂Mixing molar ratio of O SiO₂/ K₂Various surfactants were added in the amounts shown in Table 1 below to 1 L of an aqueous 4.0% potassium silicate solution with an O of 1.1.ALucari developing solution (1) ~(8)Was made.
  Silicon oxide SiO₂And potassium oxide K₂Mixing molar ratio of O SiO₂/ K₂Various surfactants were added in the amounts shown in Table 1 below to 1 L of a 6.0% potassium silicate aqueous solution having an O of 1.1.ALucari Development Replenisher (1) ~(8)Was made.
  Details of the various surfactants used here are shown below.
[0108]
[Chemical 6]

[0109]
  The lithographic printing plate obtained as described above has an output of 500 mW, a wavelength of 830 nm, a beam diameter of 17 μm (1 / e²) At a main scanning speed of 5 m / sec and kept at 25 ° C.
  The lithographic printing plate precursor is developed by an automatic processor PS900NP (Fuji Photo Film Co., Ltd.) filled with the alkali developing solution (1), and the alkali developing replenisher ( 1) 100ml / m²The 10th, 50th, and 100th lithographic printing plates were made. After completion of the development treatment, a lithographic printing plate having been subjected to plate making was obtained through a water washing step.
  Similarly, the lithographic printing plate precursor was developed using the developer and replenisher shown in Table 1, and Examples 2 to 2 were performed.8'sA lithographic printing plate was obtained by the method.
[0110]
<Evaluation of balance between image area / non-image area>
(Evaluation of developability of non-image area)
The “residual film in the non-image area” of the 10th, 50th, and 100th lithographic printing plates obtained as described above was visually observed according to the following criteria and subjected to sensory evaluation. The evaluation results are shown in Table 1 below.
-Standard-
A: The image was sufficiently developed and no image forming layer remained on the non-image area.
Δ: Some image forming layer remained on the non-image area.
X: Development failure was observed, and the image forming layer remained on the non-image area.
[0111]
(Evaluation of film slippage in the image area)
The “defects in the image area” of the 10th, 50th, and 100th lithographic printing plates obtained as described above were visually observed according to the following criteria and subjected to sensory evaluation. The evaluation results are shown in Table 1 below.
-Standard-
○: No defect was observed in the image area.
Δ: Image portion density slightly decreased, and some defects were observed.
X: The density of the image portion is greatly reduced, and there is a defective portion in the image portion.
[0112]
[Table 1]

[0113]
(Example9-16)
<Preparation of alkali developing solution containing non-reducing sugar>
  D-sorbite / potassium oxide K, combining non-reducing sugar and base₂Various surfactants are added to 1 L of a 5.0% aqueous solution of D-sorbite potassium salt made of O in the amounts shown in Table 2 below, and the alkaline developing solution of the present invention is added.(9)-(16)Was made. D-sorbite / potassium oxide K, which is a combination of non-reducing sugar and base₂Various surfactants were added to 1 L of 6.5% aqueous solution of D-sorbite potassium salt composed of O in the amounts shown in Table 2 below, and the alkali development replenisher of the present invention was added.(9)-(16)Was made.
[0114]
Using this non-reducing sugar-containing alkaline developing solution, a plate-making process was performed in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 2 below.
[0115]
[Table 2]

[0116]
As is apparent from Tables 1 and 2, according to the method of the present invention in which development processing is performed while replenishing an alkaline developer replenisher having a high surfactant concentration, SiO 2₂In both the developer containing non-reducing sugar and containing non-reducing sugar, it was possible to continuously carry out a stable development with a good balance between the image area and the non-image area while maintaining sufficient developer processability.
[0117]
【The invention's effect】
According to the present invention, while maintaining the liquid property of the alkali developing solution, the balance between the image area / non-image area at the time of development is improved and the deterioration with the passage of time is prevented, so that stable development can be performed for a long time. It is possible to provide a plate making method of a lithographic printing plate that can be performed.

Claims (3)

A lithographic printing plate making method comprising a step of imagewise exposing a lithographic printing original plate having an image forming layer containing an infrared absorber by infrared irradiation and then developing with an alkali developer containing a surfactant. ,
The developing process is a continuous process including a step of replenishing with an alkaline developer replenisher, and the surfactant concentration in the alkali developer replenisher is equal to the surfactant concentration in the alkali developer. A plate-making method of a lithographic printing plate, characterized in that it is 3 to 15 times. The lithographic printing plate making method according to claim 1, wherein the surfactant is selected from the group consisting of a nonionic surfactant and an anionic surfactant. The lithographic printing plate making method according to claim 1, wherein the surfactant is selected from nonionic surfactants.