JP2004102014A - Lithographic printing master plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithographic printing master plate which can efficiently use heat for image formation, has high sensitivity and excellent printing durability and suppresses contamination on a non-image part. <P>SOLUTION: The lithographic printing master plate is formed by providing a hydrophilic film of 0.05 to 0.5 W/(m×K) in heat conductivity on an aluminum base which has a superposed grain texture including a large mean wave structure of 2 to 30 μm and an intermediate mean wave structure of 0.05 to 5 μm in diameter and has a 0.1 to 1.0 mean ratio of the depth to the aperture diameter of the intermediate mean wave structure of 0.05 to 5 μm in diameter and then providing a heat-sensing layer which contains a water-insoluble and alkali-soluble resin and an infrared-ray absorbing dye and increases in solubility to a alkaline solution by being heated. <P>COPYRIGHT: (C)2004,JPO

Description

【００７７】
ただし、上記式［１］中の符号は、以下の通りである。
Ｔ_ｔ：チップ先端温度、Ｔ_ｂ：ヒートシンク温度、Ｔ_ｒ：リザーバ温度、
Ｋ_ｔｆ：皮膜熱伝導率、Ｋ_１：リザーバ熱伝導率、
Ｋ_２：チップ熱伝導率（無酸素銅の場合、４００Ｗ／（ｍ・Ｋ））、
Ｋ_４：（皮膜を設けない場合の）金属基体熱伝導率、
ｒ_１：チップ先端曲率半径、
Ａ_２：リザーバとチップとの接触面積、Ａ_３：チップと皮膜との接触面積、
ｔ：膜厚、ｔ_２：接触厚み（≒０）
【００７８】
膜厚（ｔ）を変化させて各温度（Ｔ_ｔ、Ｔ_ｂおよびＴ_ｒ）を測定しプロットすることにより、上記式［１］の傾きを求め、皮膜熱伝導率（Ｋ_ｔｆ）を求めることができる。即ち、この傾きは上記式［１］から明らかなように、リザーバ熱伝導率（Ｋ_１）、チップ先端の曲率半径（ｒ_１）、皮膜熱伝導率（Ｋ_ｔｆ）およびチップと皮膜との接触面積（Ａ_３）によって決まる値であり、Ｋ_１、ｒ_１およびＡ_３は、既知の値であるから、傾きからＫ_ｔｆの値を求めることができる。
【００７９】
本発明者らは、上記の測定方法を用いてアルミニウム基板状に設けた陽極酸化皮膜（Ａｌ_２Ｏ_３）の熱伝導率を求めた。膜厚を変えて温度を測定し、その結果のグラフの傾きから求められたＡｌ_２Ｏ_３の熱伝導率は、０．　６９Ｗ／（ｍ・Ｋ）であった。これは、上述したＬａｍｂｒｏｐｏｕｌｏｓらの論文の結果とよい一致を示している。そして、この結果は、薄膜の熱物性値がバルクの熱物性値（バルクのＡｌ_２Ｏ_３の熱伝導率は、２８Ｗ／（ｍ・Ｋ））とは異なることも示している。
【００８０】
本発明の平版印刷版原版の親水性皮膜の膜厚方向の熱伝導率の測定に上記方法を用いると、チップ先端を微小なものにし、かつ、押し付け荷重を一定に保つことにより、平版印刷版用に粗面化された表面についてもバラツキのない結果を得ることができるので好ましい。熱伝導率の値は、試料上の異なる複数の点、例えば、５点で測定し、その平均値として求めるのが好ましい。
【００８１】
親水性皮膜の膜厚は、傷付き難さおよび耐刷性の点で、０．１μｍ以上であるのが好ましく、０．３μｍ以上であるのがより好ましく、０．６μｍ以上であるのが特に好ましく、また、製造コストの観点から、厚い皮膜を設けるためには多大なエネルギーを必要とすることを鑑みると、５μｍ以下であるのが好ましく、３μｍ以下であるのがより好ましく、２μｍ以下であるのが特に好ましい。
【００８２】
親水性皮膜を設ける方法としては、特に限定されず、陽極酸化法、蒸着法、ＣＶＤ法、ゾルゲル法、スパッタリング法、イオンプレーティング法、拡散法等を適宜用いることができる。また、親水性樹脂またはゾルゲル液に中空粒子を混合した溶液を塗布する方法を用いることもできる。
【００８３】
中でも、陽極酸化法により酸化物を作成する処理、即ち、陽極酸化処理を用いるのが最も好適である。陽極酸化処理はこの分野で従来行われている方法で行うことができる。具体的には、硫酸、リン酸、クロム酸、シュウ酸、スルファミン酸、ベンゼンスルホン酸等の単独のまたは２種以上を組み合わせた水溶液または非水溶液の中で、アルミニウム板に直流または交流を流すと、アルミニウム板の表面に、親水性皮膜である陽極酸化皮膜を形成することができる。
陽極酸化処理の条件は、使用される電解液によって種々変化するので一概に決定され得ないが、一般的には電解液濃度１〜８０質量％、液温５〜７０℃、電流密度０．５〜６０Ａ／ｄｍ^２、電圧１〜２００Ｖ、電解時間１〜１０００秒であるのが適当である。
これらの陽極酸化処理の中でも、英国特許第１，４１２，７６８号明細書に記載されている、硫酸電解液中で高電流密度で陽極酸化処理する方法、および、米国特許第３，５１１，６６１号明細書に記載されている、リン酸を電解浴として陽極酸化処理する方法が好ましい。また、硫酸中で陽極酸化処理し、更にリン酸中で陽極酸化処理する等の多段陽極酸化処理を施すこともできる。
【００８４】
本発明においては、陽極酸化皮膜は、傷付き難さおよび耐刷性の点で、０．１ｇ／ｍ^２以上であるのが好ましく、０．３ｇ／ｍ^２以上であるのがより好ましく、２ｇ／ｍ^２以上であるのが特に好ましく、また、厚い皮膜を設けるためには多大なエネルギーを必要とすることを鑑みると、１００ｇ／ｍ^２以下であるのが好ましく、１０ｇ／ｍ^２以下であるのがより好ましく、６ｇ／ｍ^２以下であるのが特に好ましい。
【００８５】
陽極酸化皮膜には、その表面にマイクロポアと呼ばれる微細な凹部が一様に分布して形成されている。陽極酸化皮膜に存在するマイクロポアの密度は、処理条件を適宜選択することによって調整することができる。マイクロポアの密度を高くすることにより、陽極酸化皮膜の膜厚方向の熱伝導率を０．０５〜０．５Ｗ／（ｍ・Ｋ）とすることができる。
【００８６】
本発明においては、熱伝導率を下げる目的で、陽極酸化処理の後、マイクロポアのポア径を拡げるポアワイド処理を行うことが好ましい。このポアワイド処理は、陽極酸化皮膜が形成されたアルミニウム基板を酸水溶液またはアルカリ水溶液に浸せきすることにより、陽極酸化皮膜を溶解し、マイクロポアのポア径を拡大するものである。ポアワイド処理は、陽極酸化皮膜の溶解量が、好ましくは０．０１〜２０ｇ／ｍ^２、より好ましくは０．１〜５ｇ／ｍ^２、特に好ましくは０．２〜４ｇ／ｍ^２となる範囲で行われる。
【００８７】
ポアワイド処理に酸水溶液を用いる場合は、硫酸、リン酸、硝酸、塩酸等の無機酸またはこれらの混合物の水溶液を用いることが好ましい。酸水溶液の濃度は１０〜１０００ｇ／Ｌであるのが好ましく、２０〜５００ｇ／Ｌであるのがより好ましい。酸水溶液の温度は、１０〜９０℃であるのが好ましく、３０〜７０℃であるのがより好ましい。酸水溶液への浸せき時間は、１〜３００秒であるのが好ましく、２〜１００秒であるのがより好ましい。
一方、ポアワイド処理にアルカリ水溶液を用いる場合は、水酸化ナトリウム、水酸化カリウムおよび水酸化リチウムからなる群から選ばれる少なくとも一つのアルカリの水溶液を用いることが好ましい。アルカリ水溶液のｐＨは、１０〜１３であるのが好ましく、１１．５〜１３．０であるのがより好ましい。アルカリ水溶液の温度は、１０〜９０℃であるのが好ましく、３０〜５０℃であるのがより好ましい。アルカリ水溶液への浸せき時間は、１〜５００秒であるのが好ましく、２〜１００秒であるのがより好ましい。
【００８８】
また、親水性皮膜は、上述した陽極酸化皮膜のほかに、スパッタリング法、ＣＶＤ法等により設けられる無機皮膜であってもよい。無機皮膜を構成する化合物としては、例えば、酸化物、チッ化物、ケイ化物、ホウ化物、炭化物が挙げられる。また、無機皮膜は、化合物の単体のみから構成されていてもよく、化合物の混合物により構成されていてもよい。
無機皮膜を構成する化合物としては、具体的には、酸化アルミニウム、酸化ケイ素、酸化チタン、酸化ジルコニウム、酸化ハフニウム、酸化バナジウム、酸化ニオブ、酸化タンタル、酸化モリブデン、酸化タングステン、酸化クロム；チッ化アルミニウム、チッ化ケイ素、チッ化チタン、チッ化ジルコニウム、チッ化ハフニウム、チッ化バナジウム、チッ化ニオブ、チッ化タンタル、チッ化モリブデン、チッ化タングステン、チッ化クロム、チッ化ケイ素、チッ化ホウ素；ケイ化チタン、ケイ化ジルコニウム、ケイ化ハフニウム、ケイ化バナジウム、ケイ化ニオブ、ケイ化タンタル、ケイ化モリブデン、ケイ化タングステン、ケイ化クロム；ホウ化チタン、ホウ化ジルコニウム、ホウ化ハフニウム、ホウ化バナジウム、ホウ化ニオブ、ホウ化タンタル、ホウ化モリブデン、ホウ化タングステン、ホウ化クロム；炭化アルミニウム、炭化ケイ素、炭化チタン、炭化ジルコニウム、炭化ハフニウム、炭化バナジウム、炭化ニオブ、炭化タンタル、炭化モリブデン、炭化タングステン、炭化クロムが挙げられる。
【００８９】
本発明では、前記親水膜が、密度が１．０〜３．２ｇ／ｃｍ^３あるいは空隙率が２０〜７０％であるのが好ましい態様の一つである。
【００９０】
上記の条件で、低密度皮膜を形成するが、形成された皮膜の密度は、例えば、メイソン法（クロム酸／燐酸混合液溶解による陽極酸化被膜重量法）による重量測定と、断面をＳＥＭで観察して求めた膜厚から、以下の式によって算出することができる。
密度（ｇ／ｃｍ^３）＝（単位面積あたりの皮膜重量／膜厚）
ここで形成された皮膜の密度が１．０ｇ／ｃｍ^３未満では皮膜強度が低くなり、画像形成性や耐刷性等に悪影響を及ぼす可能性があり、３．２ｇ／ｃｍ^３を超えると充分な断熱性が得られず、感度向上効果が低くなる。
【００９１】
本発明においては、陽極酸化皮膜の空隙率が、２０〜７０％であるのが好ましく、３０〜６０％であるのがより好ましく、４０〜５０％であるのが特に好ましい。陽極酸化皮膜の空隙率が２０％以上であると、アルミニウム支持体への熱拡散の抑制が十分となり、高感度化の効果が十分に得られる。陽極酸化皮膜の空隙率が７０％以下であると、非画像部に汚れが発生する問題がより起こりにくくなる。
【００９２】
陽極酸化皮膜の空隙率は、以下の方法により測定することができる。
空隙率（％）＝｛１−（酸化皮膜密度／３．９８）｝ｘ１００
ここで、３．９８は化学便覧による酸化アルミニウムの密度（ｇ／ｃｍ^３）である。
【００９３】
密度が１．０〜３．２ｇ／ｃｍ^３の皮膜を作成すると、高感度と引き替えに、発生するインキ払い劣化等の印刷汚れの問題を解消できる。
【００９４】
＜封孔処理＞
本発明においては、上述したようにして親水膜を設けて得られたアルミニウム支持体に封孔処理を行ってもよい。
封孔処理皮膜は、例えば、電着封孔処理をした場合にはポアの底部から形成され、また、水蒸気封孔処理をした場合にはポアの上部から形成され、封孔処理の仕方によって封孔処理皮膜の形成され方は異なる。
本発明に好適な封孔処理の形成は親水膜内部を封孔せず、表層のマイクロポアのみを封孔する封孔処理である。
本発明に用いられる封孔処理としては、特開平４−１７６６９０号公報および特願平１０−１０６８１９号明細書（特開平１１−３０１１３５号公報）に記載の加圧水蒸気や熱水による陽極酸化皮膜の封孔処理が挙げられる。また、ケイ酸塩処理、重クロム酸塩水溶液処理、亜硝酸塩処理、酢酸アンモニウム塩処理、電着封孔処理、トリエタノールアミン処理、炭酸バリウム塩処理、極微量のリン酸塩を含む熱水処理等の公知の方法を用いて行うこともできる。中でも本発明に好適な封孔処理は、特願２００１−９８７１号明細書に記載の微粒子による封孔処理である。
微粒子による封孔処理は平均粒径８〜８００ｎｍ、好ましくは平均粒径１０〜５００ｎｍ、より好ましくは平均粒径１０〜１５０ｎｍの粒子からなる粒子層が設けられる。粒子の平均粒径が８ｎｍ以上であると、陽極酸化皮膜に存在するマイクロポアの内部に粒子が入り込んでしまうおそれが少なく、高感度化の効果が十分に得られる。粒子の平均粒径が８００ｎｍ以下であると、感熱層との密着性が十分となり、耐刷性が優れたものとなる。粒子層の厚さは、８〜８００ｎｍであるのが好ましく、１０〜５００ｎｍであるのがより好ましい。
【００９５】
本発明に用いられる粒子は、熱伝導率が６０Ｗ／（ｍ・Ｋ）以下であるのが好ましく、４０Ｗ／（ｍ・Ｋ）以下であるのがより好ましく、０．３〜１０Ｗ／（ｍ・Ｋ）以下であるのが特に好ましい。熱伝導率が６０Ｗ／（ｍ・Ｋ）以下であると、アルミニウム支持体への熱拡散の抑制が十分となり、高感度化の効果が十分に得られる。
【００９６】
粒子層を設ける方法は、特に限定されないが、アルミニウム支持体を平均粒径８〜８００ｎｍの親水性粒子を含有する電解液を用い、直流または交流を用いて電解処理する方法が好ましい。上記電解処理に用いられる交流電流の波形としては、サイン波、矩形波、三角波、台形波等が挙げられる。また、交流電流の周波数は、電源装置を製作するコストの観点から、３０〜２００Ｈｚであるのが好ましく、４０〜１２０Ｈｚであるのがより好ましい。交流電流の波形として台形波を用いる場合、電流が０からピークに達するまでの時間ｔｐはそれぞれ０．１〜２ｍｓｅｃであるのが好ましく、０．３〜１．５ｍｓｅｃであるのがより好ましい。上記ｔｐが０．１ｍｓｅｃ未満であると、電源回路のインピーダンスが影響し、電流波形の立ち上がり時に大きな電源電圧が必要となり、電源の設備コストが高くなる場合がある。
親水性粒子としては、Ａｌ_２Ｏ_３、ＴｉＯ_２、ＳｉＯ_２およびＺｒＯ_２を単独でまたは２種以上を組み合わせて用いるのが好ましい。電解液は、例えば、前記親水性粒子を含有量が全体の０．０１〜２０質量％となるように、水等に懸濁させて得られる。電解液は、電荷をプラスまたはマイナスに帯電させるために、例えば、硫酸を添加するなどして、ｐＨを調整することもできる。電解処理は、例えば、直流を用い、アルミニウム支持体を陰極として、上記電解液を用い、電圧１０〜２００Ｖで１〜６００秒間の条件で行う。
この方法によれば、容易に、陽極酸化皮膜に存在するマイクロポアの内部に空隙を残しつつ、その口をふさぐことができる。
封孔方法にはそのほかにも、溶液による浸せき処理、スプレー処理、コーティング処理、蒸着処理、スバッタリング、イオンプレーティング、溶射、鍍金等が挙げられるが、特に限定されるものではない。
【００９７】
具体的処理方法として、例えば、特開昭６０−１４９４９１号公報に記載されている、少なくとも１個のアミノ基と、カルボキシル基およびその塩の基ならびにスルホ基およびその塩の基からなる群から選ばれた少なくとも１個の基とを有する化合物からなる層、特開昭６０−２３２９９８号公報に記載されている、少なくとも１個のアミノ基と少なくとも１個のヒドロキシ基を有する化合物およびその塩から選ばれた化合物からなる層、特開昭６２−１９４９４号公報に記載されているリン酸塩を含む層、特開昭５９−１０１６５１号公報に記載されているスルホ基を有するモノマー単位の少なくとも１種を繰り返し単位として分子中に有する高分子化合物からなる層等をコーティングによって設ける方法が挙げられる。
【００９８】
また、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；置換基を有してい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、エチレンジホスホン酸等の有機ホスホン酸；置換基を有してい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、グリセロリン酸等の有機リン酸エステル；置換基を有してい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、グリセロホスフィン酸等の有機ホスフィン酸；グリシン、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基を有するアミンの塩酸塩等から選ばれる化合物の層を設ける方法も挙げられる。
【００９９】
封孔処理には、不飽和基を有するシランカップリング剤を塗設処理してもよい。シランカップリング剤としては、例えば、Ｎ−３−（アクリロキシ−２−ヒドロキシプロピル）−３−アミノプロピルトリエトキシシラン、（３−アクリロキシプロピル）ジメチルメトキシシラン、（３−アクリロキシプロピル）メチルジメトキシシラン、（３−アクリロキシプロピル）トリメトキシシラン、３−（Ｎ−アリルアミノ）プロピルトリメトキシシラン、アリルジメトキシシラン、アリルトリエトキシシラン、アリルトリメトキシシラン、３−ブテニルトリエトキシシラン、２−（クロロメチル）アリルトリメトキシシラン、メタクリルアミドプロピルトリエトキシシラン、Ｎ−（３−メタクリロキシ−２−ヒドロキシプロピル）−３−アミノプロピルトリエトキシシラン、（メタクリロキシメチル）ジメチルエトキシシラン、メタクリロキシメチルトリエトキシシラン、メタクリロキシメチルトリメトキシシラン、メタクリロキシプロピルジメチルエトキシシラン、メタクリロキシプロピルジメチルメトキシシラン、メタクリロキシプロピルメチルジエトキシシラン、メタクリロキシプロピルメチルジメトキシシラン、メタクリロキシプロピルメチルトリエトキシシラン、メタクリロキシプロピルメチルトリメトキシシラン、メタクリロキシプロピルトリス（メトキシエトキシ）シラン、メトキシジメチルビニルシラン、１−メトキシ−３−（トリメチルシロキシ）ブタジエン、スチリルエチルトリメトキシシラン、３−（Ｎ−スチリルメチル−２−アミノエチルアミノ）−プロピルトリメトキシシラン塩酸塩、ビニルジメチルエトキシシラン、ビニルジフェニルエトキシシラン、ビニルメチルジエトキシシラン、ビニルメチルジメトキシシラン、Ｏ−（ビニロキシエチル）−Ｎ−（トリエトキシシリルプロピル）ウレタン、ビニルトリエトキシシラン、ビニルトリメトキシシラン、ビニルトリ−ｔ−ブトキシシラン、ビニルトリイソプロポキシシシラン、ビニルトリフェノキシシラン、ビニルトリス（２−メトキシエトキシ）シラン、ジアリルアミノプロピルメトキシシランが挙げられる。中でも、不飽和基の反応性が速いメタクリロイル基、アクリロイル基を有するシランカップリング剤が好ましい。
【０１００】
そのほかにも、特開平５−５０７７９号公報に記載されているゾルゲルコーティング処理、特開平５−２４６１７１号公報に記載されているホスホン酸類のコーティング処理、特開平６−２３４２８４号公報、特開平６−１９１１７３号公報および特開平６−２３０５６３号公報に記載されているバックコート用素材をコーティングにより処理する方法、特開平６−２６２８７２号公報に記載されているホスホン酸類の処理、特開平６−２９７８７５号公報に記載されているコーティング処理、特開平１０−１０９４８０号公報に記載されている陽極酸化処理する方法、特願平１０−２５２０７８号明細書（特開２０００−８１７０４号公報）および特願平１０−２５３４１１号明細書（特開２０００−８９４６６号公報）に記載されている浸せき処理方法等が挙げられ、いずれの方法を用いてもよい。
【０１０１】
＜親水性表面処理＞
本発明においては、上述したようにして親水性皮膜を設けて得られた本発明のアルミニウム支持体を、更に１種以上の親水性化合物を含有する水溶液へ浸せきすることにより、親水性表面処理を行ってもよい。親水性化合物としては、例えば、ポリビニルホスホン酸、スルホン酸基を有する化合物、糖類化合物、ケイ酸塩化合物が好適に挙げられる。
【０１０２】
スルホン酸基を有する化合物には、芳香族スルホン酸、そのホルムアルデヒド縮合物、それらの誘導体、およびそれらの塩が含まれる。
芳香族スルホン酸としては、例えば、フェノールスルホン酸、カテコールスルホン酸、レゾルシノールスルホン酸、ベンゼンスルホン酸、トルエンスルホン酸、リグニンスルホン酸、ナフタレンスルホン酸、アセナフテン−５−スルホン酸、フェナントレン−２−スルホン酸、ベンズアルデヒド−２（または３）−スルホン酸、ベンズアルデヒド−２，４（または３，５）−ジスルホン酸、オキシベンジルスルホン酸類、スルホ安息香酸、スルファニル酸、ナフチオン酸、タウリンが挙げられる。中でも、ベンゼンスルホン酸、ナフタレンスルホン酸、リグニンスルホン酸が好ましい。また、ベンゼンスルホン酸、ナフタレンスルホン酸、リグニンスルホン酸のホルムアルデヒド縮合物も好ましい。
更に、これらは、スルホン酸塩として使用してもよい。例えば、ナトリウム塩、カリウム塩、リチウム塩、カルシウム塩、マグネシウム塩が挙げられる。中でも、ナトリウム塩、カリウム塩が好ましい。
スルホン酸基を有する化合物を含有する水溶液のｐＨは、４〜６．５であるのが好ましく、硫酸、水酸化ナトリウム、アンモニア等を用いて上記ｐＨ範囲に調整することができる。
【０１０３】
糖類化合物には、単糖類およびその糖アルコール、オリゴ糖類、多糖類、ならびに、配糖体が含まれる。
単糖類およびその糖アルコールとしては、例えば、グリセロール等のトリオース類およびその糖アルコール類；トレオース、エリトリトール等のテトロースおよびその糖アルコール類；アラビノース、アラビトール等のペントースおよびその糖アルコール類；グルコース、ソルビトール等のヘキソースおよびその糖アルコール類；Ｄ−グリセロ−Ｄ−ガラクトヘプトース、Ｄ−グリセロ−Ｄ−ガラクトヘプチトール等のヘプトースおよびその糖アルコール類；Ｄ−エリトロ−Ｄ−ガラクトオクチトール等のオクトースおよびその糖アルコール類；Ｄ−エリトロ−Ｌ−グルコ−ノヌロース等のノノースおよびその糖アルコール類が挙げられる。
オリゴ糖類としては、例えば、サッカロース、トレハロース、ラクトース等の二糖類；ラフィノース等の三糖類が挙げられる。
多糖類としては、例えば、アミロース、アラビナン、シクロデキストリン、アルギン酸セルロースが挙げられる。
【０１０４】
本発明において、「配糖体」とは、糖部分と非糖部分がエーテル結合等を介して結合している化合物をいう。
配糖体は非糖部分により分類することができる。例えば、アルキル配糖体、フェノール配糖体、クマリン配糖体、オキシクマリン配糖体、フラボノイド配糖体、アントラキノン配糖体、トリテルペン配糖体、ステロイド配糖体、からし油配糖体が挙げられる。
糖部分としては、上述した単糖類およびその糖アルコール；オリゴ糖類；多糖類が挙げられる。中でも、単糖類、オリゴ糖類が好ましく、単糖類、二糖類がより好ましい。
好ましい配糖体の例として、下記式（１）で表される化合物が挙げられる。
【０１０５】
【化１】

【０１０６】
上記式（１）中、Ｒは、炭素原子数１〜２０の直鎖のまたは分枝を有する、アルキル基、アルケニル基またはアルキニル基を表す。
炭素原子数１〜２０のアルキル基としては、例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基、ノナデシル基、エイコシル基が挙げられ、これらは直鎖であっても、分枝を有していてもよく、また、環状アルキル基であってもよい。
炭素原子数１〜２０のアルケニル基としては、例えば、アリル基、２−ブテニル基が挙げられ、これらは直鎖であっても、分枝を有していてもよく、また、環状アルケニル基であってもよい。
炭素原子数１〜２０のアルキニル基としては、例えば、１−ペンチニル基が挙げられ、これらは直鎖であっても、分枝を有していてもよく、また、環状アルキニル基であってもよい。
【０１０７】
上記式（１）で表される具体的な化合物としては、例えば、メチルグルコシド、エチルグルコシド、プロピルグルコシド、イソプロピルグルコシド、ブチルグルコシド、イソブチルグルコシド、ｎ−ヘキシルグルコシド、オクチルグルコシド、カプリルグルコシド、デシルグルコシド、２−エチルヘキシルグルコシド、２−ペンチルノニルグルコシド、２−ヘキシルデシルグルコシド、ラウリルグルコシド、ミリスチルグルコシド、ステアリルグルコシド、シクロヘキシルグルコシド、２−ブチニルグルコシドが挙げられる。これらの化合物は、配糖体の一種であるグルコシドで、ブドウ糖のヘミアセタールヒドロキシル基が他の化合物をエーテル状に結合したものであり、例えば、グルコースとアルコール類とを反応させる公知の方法により得ることができる。これらのアルキルグルコシドの一部は、ドイツＨｅｎｋｅｌ社により商品名グルコポン（ＧＬＵＣＯＰＯＮ）として市販されており、本発明ではそれを用いることができる。
【０１０８】
好ましい配糖体の別の例としては、サポニン類、ルチントリハイドレート、ヘスペリジンメチルカルコン、ヘスペリジン、ナリジンハイドレート、フェノール−β−Ｄ−グルコピラノシド、サリシン、３´，５，７−メトキシ−７−ルチノシドが挙げられる。
【０１０９】
糖類化合物を含有する水溶液のｐＨは、８〜１１であるのが好ましく、水酸化カリウム、硫酸、炭酸、炭酸ナトリウム、リン酸、リン酸ナトリウム等を用いて上記ｐＨ範囲に調整することができる。
【０１１０】
ポリビニルホスホン酸の水溶液は、濃度が０．１〜５質量％であるのが好ましく、０．２〜２．５％であるのがより好ましい。浸せき温度は１０〜７０℃であるのが好ましく、３０〜６０℃であるのがより好ましい。浸せき時間は１〜２０秒であるのが好ましい。
また、スルホン酸基を有する化合物の水溶液は、濃度が０．０２〜０．２質量％であるのが好ましい。浸せき温度は６０〜１００℃であるのが好ましい。浸せき時間は１〜３００秒であるのが好ましく、１０〜１００秒であるのがより好ましい。
更に、糖類化合物の水溶液は、濃度が０．５〜１０質量％であるのが好ましい。浸せき温度は４０〜７０℃であるのが好ましい。浸せき時間は２〜３００秒であるのが好ましく、５〜３０秒であるのがより好ましい。
【０１１１】
本発明では、親水性化合物を含有する水溶液として、上述したような有機化合物の水溶液のほかに、アルカリ金属ケイ酸塩水溶液、フッ化ジルコニウムカリウム（Ｋ_２ＺｒＦ_６）水溶液、リン酸塩／無機フッ素化合物を含む水溶液等の無機化合物水溶液も好適に用いられる。
【０１１２】
アルカリ金属ケイ酸塩水溶液処理は、好ましくは濃度が０．０１〜３０質量％、より好ましくは０．１〜１０質量％であり、２５℃でのｐＨが好ましくは１０〜１３であるアルカリ金属ケイ酸塩の水溶液に、支持体を、好ましくは１０〜１００℃、より好ましくは２０〜８０℃で、好ましくは０．５〜４０秒間、より好ましくは１〜２０秒間浸せきすることにより行う。
【０１１３】
本発明に用いられるアルカリ金属ケイ酸塩は、例えば、ケイ酸ナトリウム、ケイ酸カリウム、ケイ酸リチウムが挙げられる。中でも、ケイ酸ナトリウム、ケイ酸カリウムが好ましい。
アルカリ金属ケイ酸塩の水溶液は、ｐＨを高くするために、水酸化ナトリウム、水酸化カリウム、水酸化リチウム等の水酸化物を適当量含有してもよい。中でも、水酸化ナトリウム、水酸化カリウムが好ましい。
また、アルカリ金属ケイ酸塩の水溶液は、アルカリ土類金属塩または４族（第ＩＶＢ族）金属塩を含有してもよい。アルカリ土類金属塩としては、例えば、硝酸カルシウム、硝酸ストロンチウム、硝酸マグネシウム、硝酸バリウム等の硝酸塩；硫酸塩；塩酸塩；リン酸塩；酢酸塩；シュウ酸塩；ホウ酸塩等の水溶性塩が挙げられる。４族（第ＩＶＢ族）金属塩としては、例えば、四塩化チタン、三塩化チタン、フッ化チタンカリウム、シュウ酸チタンカリウム、硫酸チタン、四ヨウ化チタン、塩化酸化ジルコニウム、二酸化ジルコニウム、オキシ塩化ジルコニウム、四塩化ジルコニウムが挙げられる。これらのアルカリ土類金属塩および４族（第ＩＶＢ族）金属塩は、単独でまたは２種以上組み合わせて用いられる。
【０１１４】
アルカリ金属ケイ酸塩処理によって吸着するＳｉ量は蛍光Ｘ線分析装置により測定され、その吸着量は約０．１〜１５．０ｍｇ／ｍ^２であるのが好ましい。
このアルカリ金属ケイ酸塩処理により、アルミニウム支持体表面のアルカリ現像液に対する耐溶解性向上効果が得られ、アルミニウム成分の現像液中への溶出が抑制されて、現像液の疲労に起因する現像カスの発生を低減することができる。
【０１１５】
フッ化ジルコニウムカリウム水溶液処理は、好ましくは濃度が０．１〜１０質量％、より好ましくは０．５〜２質量％のフッ化ジルコニウムカリウムの水溶液に、支持体を、好ましくは３０〜８０℃で、好ましくは６０〜１８０秒間浸せきすることにより行う。
【０１１６】
リン酸塩／無機フッ素化合物処理は、好ましくはリン酸塩化合物濃度が５〜２０質量％、無機フッ素化合物濃度が０．０１〜１質量％であり、好ましくはｐＨが３〜５の水溶液に、支持体を、好ましくは２０〜１００℃、より好ましくは４０〜８０℃で、好ましくは２〜３００秒間、より好ましくは５〜３０秒間浸せきすることにより行う。
【０１１７】
本発明に用いられるリン酸塩としては、例えば、アルカリ金属、アルカリ土類金属等の金属のリン酸塩が挙げられる。
具体的には、例えば、リン酸亜鉛、リン酸アルミニウム、リン酸アンモニウム、リン酸水素二アンモニウム、リン酸二水素アンモニウム、リン酸一アンモニウム、リン酸一カリウム、リン酸一ナトリウム、リン酸二水素カリウム、リン酸水素二カリウム、リン酸カルシウム、リン酸水素アンモニウムナトリウム、リン酸水素マグネシウム、リン酸マグネシウム、リン酸第一鉄、リン酸第二鉄、リン酸二水素ナトリウム、リン酸ナトリウム、リン酸水素二ナトリウム、リン酸鉛、リン酸二アンモニウム、リン酸二水素カルシウム、リン酸リチウム、リンタングステン酸、リンタングステン酸アンモニウム、リンタングステン酸ナトリウム、リンモリブデン酸アンモニウム、リンモリブデン酸ナトリウム；亜リン酸ナトリウム、トリポリリン酸ナトリウム、ピロリン酸ナトリウムが挙げられる。中でも、リン酸二水素ナトリウム、リン酸水素二ナトリウム、リン酸二水素カリウム、リン酸水素二カリウムが好ましい。
【０１１８】
また、本発明に用いられる無機フッ素化合物としては、金属フッ化物が好適に挙げられる。
具体的には、例えば、フッ化ナトリウム、フッ化カリウム、フッ化カルシウム、フッ化マグネシウム、ヘキサフルオロジルコニウムナトリウム、ヘキサフルオロジルコニウムカリウム、ヘキサフルオロチタン酸ナトリウム、ヘキサフルオロチタン酸カリウム、ヘキサフルオロジルコニウム水素酸、ヘキサフルオロチタン水素酸、ヘキサフルオロジルコニウムアンモニウム、ヘキサフルオロチタン酸アンモニウム、ヘキサフルオロケイ酸、フッ化ニッケル、フッ化鉄、フッ化リン酸、フッ化リン酸アンモニウムが挙げられる。
【０１１９】
リン酸塩／無機フッ素化合物処理に用いられる水溶液は、リン酸塩および無機フッ素化合物をそれぞれ１種または２種以上含有することができる。
【０１２０】
支持体は、これらの親水性化合物を含有する水溶液へ浸せきした後には、水等によって洗浄され、乾燥される。
【０１２１】
上述した封孔処理や親水性表面処理により、陽極酸化処理後のポアワイド処理により向上した感度と引き替えに発生するインキ払い性劣化等の印刷汚れの問題が解消される。即ち、ポア径が拡大したことにより、印刷時、特に印刷機が停止し、平版印刷版が印刷機上で放置された後の印刷再スタート時に、インキが取れにくくなる現象（インキ払い性劣化）が起こりやすくなる問題があるが、封孔処理や親水性表面処理が施されていると、上記問題が軽減される。
【０１２２】
＜下塗層＞
本発明においては、このようにして得られた本発明のアルミニウム支持体上に、感熱層を設ける前に、必要に応じて、例えば、ホウ酸亜鉛等の水溶性金属塩のような無機下塗層や、有機下塗層を設けてもよい。
【０１２３】
有機下塗層に用いられる有機化合物としては、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；スルホン酸基を側鎖に有する重合体および共重合体；ポリアクリル酸；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；置換基を有してい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、エチレンジホスホン酸等の有機ホスホン酸；置換基を有してい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、グリセロリン酸等の有機リン酸；置換基を有してい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、グリセロホスフィン酸等の有機ホスフィン酸；グリシン、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；黄色染料が挙げられる。これらは単独で用いてもよく、２種以上を混合して用いてもよい。
【０１２４】
有機下塗層は、水もしくはメタノール、エタノール、メチルエチルケトン等の有機溶媒、またはそれらの混合溶剤に、上記有機化合物を溶解させた溶液をアルミニウム板上に塗布し乾燥することにより設けられる。上記有機化合物を溶解させた溶液の濃度は、０．００５〜１０質量％であるのが好ましい。塗布の方法は、特に限定されず、バーコーター塗布、回転塗布、スプレー塗布、カーテン塗布等のいずれの方法も用いることができる。
有機下塗層の乾燥後の被覆量は、２〜２００ｍｇ／ｍ^２であるのが好ましく、５〜１００ｍｇ／ｍ^２であるのがより好ましい。上記範囲であると、耐刷性がより良好になる。
【０１２５】
＜バックコート層＞
上述したようにして得られる支持体には、平版印刷版原版としたときに、重ねても感熱層が傷付かないように、裏面（感熱層が設けられない側の面）に、有機高分子化合物からなる被覆層（以下「バックコート層」ともいう。）を必要に応じて設けてもよい。
バックコート層の主成分としては、ガラス転移点が２０℃以上の、飽和共重合ポリエステル樹脂、フェノキシ樹脂、ポリビニルアセタール樹脂および塩化ビニリデン共重合樹脂からなる群から選ばれる少なくとも１種の樹脂を用いるのが好ましい。
【０１２６】
飽和共重合ポリエステル樹脂は、ジカルボン酸ユニットとジオールユニットとからなる。ジカルボン酸ユニットとしては、例えば、フタル酸、テレフタル酸、イソフタル酸、テトラブロムフタル酸、テトラクロルフタル酸等の芳香族ジカルボン酸；アジピン酸、アゼライン酸、コハク酸、シュウ酸、スベリン酸、セバチン酸、マロン酸、１，４−シクロヘキサンジカルボン酸等の飽和脂肪族ジカルボン酸が挙げられる。
【０１２７】
バックコート層は、更に、着色のための染料や顔料、支持体との密着性を向上させるためのシランカップリング剤、ジアゾニウム塩からなるジアゾ樹脂、有機ホスホン酸、有機リン酸、カチオン性ポリマー、滑り剤として通常用いられるワックス、高級脂肪酸、高級脂肪酸アミド、ジメチルシロキサンからなるシリコーン化合物、変性ジメチルシロキサン、ポリエチレン粉末等を適宜含有することができる。
【０１２８】
バックコート層の厚さは、基本的には合紙がなくても、後述する感熱層を傷付けにくい程度であればよく、０．０１〜８μｍであるのが好ましい。厚さが０．０１μｍ未満であると、平版印刷版原版を重ねて取り扱った場合の感熱層の擦れ傷を防ぐことが困難である。また、厚さが８μｍを超えると、印刷中、平版印刷版周辺で用いられる薬品によってバックコート層が膨潤して厚みが変動し、印圧が変化して印刷特性を劣化させることがある。
【０１２９】
バックコート層を支持体の裏面に設ける方法としては、種々の方法を用いることができる。例えば、上記バックコート層用成分を適当な溶媒に溶解し溶液にして塗布し、または、乳化分散液して塗布し、乾燥する方法；あらかじめフィルム状に成形したものを接着剤や熱での支持体に貼り合わせる方法；溶融押出機で溶融被膜を形成し、支持体に貼り合わせる方法が挙げられる。好適な厚さを確保するうえで最も好ましいのは、バックコート層用成分を適当な溶媒に溶解し溶液にして塗布し、乾燥する方法である。この方法においては、特開昭６２−２５１７３９号公報に記載されているような有機溶剤を単独でまたは混合して、溶媒として用いることができる。
【０１３０】
平版印刷版原版の製造においては、裏面のバックコート層と表面の感熱層のどちらを先に支持体上に設けてもよく、また、両者を同時に設けてもよい。
【０１３１】
［平版印刷版原版］
本発明の平版印刷版原版は、上記のようにして得られたアルミニウム支持体上に、水不溶性且つアルカリ可溶性樹脂および赤外線吸収染料を含み、加熱によりアルカリ性水溶液に対する溶解性が増大する感熱層を設けてなる。
【０１３２】
＜画像形成層＞
本発明の平版印刷版原版に用いられる画像形成層（記録層、感熱層）は、水不溶性且つアルカリ可溶性樹脂および赤外線吸収染料を含み、加熱によりアルカリ性水溶液に対する溶解性が増大する感熱層であり、２層以上からなる感熱層が好ましい。アルカリ可溶層と表面難溶化層とを別々に設けることができるため、より大きなデイスクリミネーションが得られる。２層以上からなる感熱層としては、例えば、アルカリ易溶性の中間層および加熱によりアルカリ可溶化する感光層を順次設けてなる感熱層および中間層とは別に重層構造をとる感熱層を設けたものが好ましい。以下、アルカリ易溶性の中間層および加熱によりアルカリ可溶化する感熱層について説明する。なお、本発明の平版印刷版原版には、以下に説明する「中間層」および「感熱層」のような２層構成をとるもののほか、１層の感熱層において、　アルミニウム支持対側におけるアルカリに対する溶解性が、表面側における溶解性より高くなっているような構成のものが含まれる。
【０１３３】
上記感熱層は、アルカリ可溶性樹脂（アルカリ可溶性高分子化合物ともいう）と赤外線吸収染料（光熱変換物質ともいう）とを含有する。
アルカリ可溶性高分子化合物は、高分子中に酸性基を含有する単独重合体、これらの共重合体、およびこれらの混合物を包含し、特に、（１）フェノール性ヒドロキシ基（−Ａｒ−ＯＨ）、（２）スルホンアミド基（−ＳＯ_２ＮＨ−Ｒ）のような酸性基を有するものが、アルカリ現像液に対する溶解性の点で好ましい。とりわけ、赤外線レーザ等による露光での画像形成性に優れる点で、フェノール性ヒドロキシ基を有することが好ましい。例えば、フェノールホルムアルデヒド樹脂、ｍ−クレゾールホルムアルデヒド樹脂、ｐ−クレゾールホルムアルデヒド樹脂、ｍ−／ｐ−混合クレゾールホルムアルデヒド樹脂、フェノール／クレゾール（ｍ−、ｐ−およびｍ−／ｐ−混合のいずれでもよい）混合ホルムアルデヒド樹脂等のノボラック樹脂；ピロガロールアセトン樹脂が好ましく挙げられる。更に詳しくは特開２００１−３０５７２２号公報の［００２３］〜［００４２］に記載されている高分子が好ましく用いられる。
【０１３４】
光熱変換物質は、露光エネルギーを熱に変換して感熱層の露光部領域の相互作用解除を効率よく行うことを可能とする。記録感度の観点から、波長７００〜１２００ｎｍの赤外域に光吸収域がある顔料または染料が好ましい。染料としては、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（例えば、ニッケルチオレート錯体）等が挙げられる。中でも、シアニン染料が好ましく、例えば、特開２００１−３０５７２２号公報の一般式（Ｉ）で示されたシアニン染料が挙げられる。
【０１３５】
上記感熱層に用いられる中間層としては、特開２０００−１０５４６２号公報に記載されている、酸基を有する構成成分とオニウム基を有する構成成分とを有する高分子化合物を含有する中間層が挙げられる。
【０１３６】
上記感熱層に用いられる組成物には、特開平７−９２６６０号公報の［００２４］〜［００２７］に記載されている感度調節剤、焼出剤、染料等の化合物や同公報の［００３１］に記載されているような塗布性を良化するための界面活性剤を加えることが好ましい。詳しくは特開２００１−３０５７２２号公報の［００５３］〜［００５９］に記載されている化合物が好ましい。
上記感熱層は単層であってもよいし、特開平１１−２１８９１４号公報に記載されているような２層構造であるのが好ましい。
上記感熱層と支持体との間には、下塗層を設けることが好ましい。下塗層に含有される成分としては特開２００１−３０５７２２号公報の［００６８］に記載されている種々の有機化合物が挙げられる。
【０１３７】
＜塗布方法＞
上記画像記録層形成液を上記平版印刷版用支持体の粗面化面に塗布する方法としては、コーティングロッドを用いる方法、エクストルージョン型コーターを用いる方法、スライドビードコーターを用いる方法等、従来公知の方法が使用でき、また公知の条件に従って行うことができる。
【０１３８】
上記画像記録層形成液を塗布後のアルミニウム板を乾燥する装置としては、特開平６−６３４８７号公報に記載の、乾燥装置内にパスロールを配置し、上記パスロールで搬送しつつ乾燥するアーチ型ドライヤー、上下からノズルによりエアーを供給し、ウェブを浮上させながら乾燥するエアードライヤー、高温に加熱された媒体からの輻射熱で乾燥する輻射熱ドライヤー、およびローラを加熱し、上記ローラとの接触による伝導伝熱により乾燥するローラドライヤー等がある。
【０１３９】
［平版印刷版］
本発明の平版印刷版原版は、画像記録層に応じた種々の処理方法により、平版印刷版とされる。
一般には、像露光を行う。像露光に用いられる活性光線の光源としては、例えば、水銀灯、メタルハライドランプ、キセノンランプ、ケミカルランプが挙げられる。レーザビームとしては、例えば、ヘリウム・ネオンレーザ（Ｈｅ−Ｎｅレーザ）、アルゴンレーザ、クリプトンレーザ、ヘリウム・カドミウムレーザ、ＫｒＦエキシマーレーザ、半導体レーザ、ＹＡＧレーザ、ＹＡＧ−ＳＨＧレーザが挙げられる。
上記露光の後、現像液を用いて現像して平版印刷版を得るのが好ましい。平版印刷版原版に用いられる好ましい現像液は、アルカリ現像液であれば特に限定されないが、有機溶剤を実質的に含有しないアルカリ性の水溶液が好ましい。また、アルカリ金属ケイ酸塩を実質的に含有しない現像液を用いて現像することもできる。アルカリ金属ケイ酸塩を実質的に含有しない現像液を用いて現像する方法については、特開平１１−１０９６３７号公報に詳細に記載されており、該公報に記載されている内容を用いることができる。また、平版印刷版原版をアルカリ金属ケイ酸塩を含有する現像液を用いて現像することもできる。
【０１４０】
【実施例】
以下に実施例を示して本発明を具体的に説明するが、本発明はこれらに限られるものではない。
【０１４１】
＜実施例１〜１０および比較例１〜７＞
１．平版印刷版用支持体（アルミニウム支持体）の製造
＜アルミニウム板＞
Ｓｉ：０．０６質量％、Ｆｅ：０．３０質量％、Ｃｕ：０．００１質量％、Ｍｎ：０．００１質量％、Ｍｇ：０．００１質量％、Ｚｎ：０．００１質量％、Ｔｉ：０．０３質量％を含有し、残部はＡｌと不可避不純物のアルミニウム合金を用いて溶湯を調製し、溶湯処理およびろ過を行った上で、厚さ５００ｍｍ、幅１２００ｍｍの鋳塊をＤＣ鋳造法で作成した。表面を平均１０ｍｍの厚さで面削機により削り取った後、５５０℃で、約５時間均熱保持し、温度４００℃に下がったところで、熱間圧延機を用いて厚さ２．７ｍｍの圧延板とした。更に、連続焼鈍機を用いて熱処理を５００℃で行った後、冷間圧延で、厚さ０．２４ｍｍに仕上げ、ＪＩＳ　１０５０材のアルミニウム板を得た。このアルミニウム板を幅１０３０ｍｍに調整した。
【０１４２】
得られたアルミニウム板について、下記に示す粗面化処理方法および親水性皮膜形成方法を第１表に示す組み合わせで、順次行い、実施例１〜１０および比較例１〜７のアルミニウム支持体を得た。
【０１４３】
【表１】

【０１４４】
＜粗面化処理方法＞
粗面化処理方法Ａ
以下の（１）〜（６）の各種処理を連続的に行った。
なお、各処理および水洗の後にはニップローラで液切りを行った。
【０１４５】
（１）機械的粗面化処理
比重１．１２のパミス（研磨剤、平均粒径５０μｍ）と水との懸濁液を研磨スラリー液として、スプレー管によってアルミニウム板の表面に供給しながら、ナイロンブラシが回転するブラシローラを用いて機械的粗面化処理を行った。
使用したナイロンブラシの材質は６，１０−ナイロンであり、毛長は５０ｍｍであり、毛の直径は０．４８ｍｍであった。このナイロンブラシはφ３００ｍｍのステンレス製の筒に穴をあけて密になるように植毛されたものである。
また、ブラシローラには、ナイロンブラシが３本使用されており、ブラシ下部に備えられた２本の支持ローラ（φ２００ｍｍ）間の距離は３００ｍｍであった。
上記ブラシローラは、ブラシを回転させる駆動モータの負荷を、ナイロンブラシがアルミニウム板に押さえつけられる前の負荷に対して管理し、粗面化後のアルミニウム板の平均算術粗さ（Ｒ_ａ）が０．４５μｍ（以下、「Ｒ_ａ」という。）になるように押さえつけた。ブラシの回転方向はアルミニウム板の移動方向と同じであった。その後、水洗を行った。
また、研磨剤の濃度は、あらかじめ研磨剤濃度と温度と比重との関係から作成したテーブルを参照し、温度および比重から研磨剤濃度を求め、フィードバック制御によって水と研磨剤とを添加し、上記研磨剤の濃度を一定に保った。また、研磨剤が粉砕して粒度が小さくなると粗面化されたアルミニウム板の表面形状が変化するので、サイクロンによって粒度の小さな研磨剤は系外に逐次排出した。研磨剤の粒径は１〜１００μｍの範囲であった。
【０１４６】
（２）アルカリエッチング処理
ＮａＯＨ２７質量％およびアルミニウムイオン６．５質量％を含有する液温７０℃の水溶液をスプレー管によってアルミニウム板に吹き付けて、アルカリエッチング処理を行った。アルミニウム板の、後に電気化学的粗面化処理を行う面の溶解量は８ｇ／ｍ^２であり、その裏面の溶解量は２ｇ／ｍ^２であった。
アルカリエッチング処理に用いたエッチング液の濃度は、あらかじめＮａＯＨ濃度と、アルミニウムイオン濃度と、温度と、比重と、液の導電率との関係から作成したテーブルを参照し、温度、比重、および導電率からエッチング液濃度を求め、フィードバック制御によって水と４８質量％ＮａＯＨ水溶液とを添加することにより一定に保った。その後、水洗を行った。
【０１４７】
（３）デスマット処理
液温３５℃の硝酸水溶液をスプレーを用いてアルミニウム板に吹き付けて、１０秒間デスマット処理を行った。硝酸水溶液は、次の工程で用いる電解装置からのオーバーフロー廃液を使用した。ついで、デスマット処理液を吹き付けるスプレー管を数カ所設置して、次の工程までアルミニウム板の表面が乾かないようにした。
【０１４８】
（４）電気化学的粗面化処理
図１に示した台形波の交流電流と図２に示した電解装置２槽とを用いて連続的に電気化学的粗面化処理を行った。酸性水溶液としては、硝酸９．５ｇ／Ｌの硝酸水溶液（アルミニウムイオン５．０ｇ／Ｌおよびアンモニウムイオン０．０７ｇ／Ｌを含む。）を用いた。液温は５０℃であった。また、交流電流は、電流値がゼロからピークに達するまでの時間ｔｐおよびｔｐ´が１ｍｓｅｃであり、カーボン電極を対極とした。交流電流のピーク時の電流密度は、アルミニウム板が陽極時および陰極時ともに５０Ａ／ｄｍ^２であった。更に、交流電流の陰極時電気量（Ｑ_Ｃ）と陽極時電気量（Ｑ_Ａ）との比（Ｑ_Ｃ／Ｑ_Ａ）は０．９５、ｄｕｔｙは０．５０、周波数は６０Ｈｚおよび陽極時の電気量の総和は２００Ｃ／ｄｍ^２であった。その後、スプレーによって水洗を行った。
硝酸水溶液の濃度コントロールは、６７質量％の硝酸原液と水とを、通電量に比例して添加し、硝酸と水との添加容積と同量の酸性水溶液（硝酸水溶液）を逐次電解装置からオーバーフローさせて電解装置系外に排出して行った。また、これとともに、あらかじめ硝酸濃度とアルミニウムイオン濃度と温度と液の導電率と液の超音波伝搬速度との関係から作成したテーブルを参照し、硝酸水溶液の温度、導電率、超音波伝搬速度から該硝酸水溶液の濃度を求め、硝酸原液と水との添加量を逐次調整する制御を行って濃度を一定に保った。
【０１４９】
（５）アルカリエッチング処理
ＮａＯＨ２６質量％およびアルミニウムイオン６．５質量％を含有する液温４５℃の水溶液を、アルミニウム板にスプレーを用いて吹き付けて、アルカリエッチング処理を行った。アルミニウム板の溶解量は０．３ｇ／ｍ^２であった。エッチング液の濃度はあらかじめＮａＯＨ濃度とアルミニウムイオン濃度と温度と比重と液の導電率との関係から作成したテーブルを参照し、温度、比重および導電率からエッチング液濃度を求め、フィードバック制御によって水と４８質量％ＮａＯＨ水溶液とを添加して、一定に保った。その後、水洗を行った。
【０１５０】
（６）酸性エッチング処理
硫酸（硫酸濃度３００ｇ／Ｌ、アルミニウムイオン濃度１５ｇ／Ｌ）を酸性エッチング液とし、これをスプレー管から８０℃で８秒間アルミニウム板に吹き付けて、酸性エッチング処理を行った。酸性エッチング液の濃度は、あらかじめ硫酸濃度とアルミニウムイオン濃度と温度と比重と液の導電率との関係から作成したテーブルを参照して、温度、比重および導電率から酸性エッチング液濃度を求め、フィードバック制御によって水と５０質量％硫酸とを添加して、一定に保った。その後、水洗を行った。
【０１５１】
粗面化処理方法Ｂ
粗面化処理方法Ｂは、上記（１）において、ナイロンブラシの毛の直径を０．２５ｍｍ、研磨剤パミスの平均粒径を２５μｍとし、Ｒ_ａを０．３５μｍとした以外は、粗面化処理方法Ａと同様に行った。
【０１５２】
粗面化処理方法Ｃ
粗面化処理方法Ｃは、上記（１）において、ナイロンブラシの毛の直径を０．５７ｍｍ、ナイロンブラシを５本（ブラシ下部に備えられた２本の支持ローラ（φ２００ｍｍ）間の距離は３００ｍｍ）とし、Ｒ_ａを０．５８μｍとした以外は、粗面化処理方法Ａと同様に行った。
【０１５３】
粗面化処理方法Ｄ
粗面化処理方法Ｄは、上記（４）において、酸性水溶液として塩酸５．０ｇ／Ｌ水溶液（アルミニウムイオン５ｇ／Ｌを含む。）を用い、液温を３５℃、ｔｐおよびｔｐ´を０．８ｍｓｅｃ、電流密度を２５Ａ／ｄｍ^２、ｄｕｔｙを０．５０、陽極時の電気量の総和を５０Ｃ／ｄｍ^２とした以外は、粗面化処理方法Ａと同様に行った。
なお、補助アノードにはフェライトを用いた。
【０１５４】
粗面化処理方法Ｅ
粗面化処理方法Ｅは、上記粗面化処理方法Ａの（５）において、アルミニウム板の溶解量を１．０ｇ／ｍ^２とした以外は、粗面化処理方法Ａと同様に行った。
【０１５５】
粗面化処理方法Ｆ
粗面化処理方法Ｆは、上記（４）において、酸性水溶液の液温を３０℃とした以外は、粗面化処理方法Ａと同様に行った。
【０１５６】
粗面化処理方法Ｇ
粗面化処理方法Ｇは、上記粗面化処理方法Ａの（５）において、アルミニウム板の溶解量を０．１ｇ／ｍ^２とした以外は、粗面化処理方法Ａと同様に行った。
【０１５７】
粗面化処理方法Ｈ
粗面化処理方法Ｈは、上記（１）を行わなかった以外は、粗面化処理方法Ａと同様に行った。
【０１５８】
粗面化処理方法Ｉ
粗面化処理方法Ｉは、上記（１）において、ナイロンブラシの毛の直径を０．８５ｍｍ、Ｒ_ａを０．７５μｍとした以外は、粗面化処理方法Ａと同様に行った。
【０１５９】
粗面化処理方法Ｊ
粗面化処理方法Ｊは、上記（４）を行わなかった以外は、粗面化処理方法Ａと同様に行った。
【０１６０】
粗面化処理方法Ｋ
粗面化処理方法Ｋは、上記粗面化処理方法Ａの（５）において、アルミニウム板の溶解量を１．５ｇ／ｍ^２とした以外は、粗面化処理方法Ａと同様に行った。
【０１６１】
粗面化処理方法Ｌ
粗面化処理方法Ｌは、上記（５）を行わなかった以外は、粗面化処理方法Ａと同様に行った。
【０１６２】
＜親水性皮膜形成方法＞
親水性皮膜形成方法（ａ）
上記粗面化処理に続いて、下記の親水性皮膜形成方法を順次行い親水性皮膜を設けてアルミニウム支持体を得た。
【０１６３】
（７）陽極酸化処理
シュウ酸濃度５０ｇ／Ｌの水溶液（アルミニウムイオン０．５質量％を含む。）を、温度３０℃、陽極酸化時間１５０秒の条件でアルミニウム板の陽極酸化処理を行い、陽極酸化皮膜を形成した。陽極酸化処理液の濃度は、あらかじめシュウ酸濃度とアルミニウムイオン濃度と温度と比重と液の導電率との関係から作成したテーブルを参照して、温度、比重および導電率から液濃度を求め、フィードバック制御によって水とシュウ酸とを添加して、一定に保った。その後、スプレーによって水洗を行った。
【０１６４】
（８）ポアワイド処理
陽極酸化処理後のアルミニウム板をｐＨ１３のＮａＯＨ水溶液に５０℃で１分間浸せきして、ポアワイド処理を行った。
【０１６５】
（９）封孔処理
コロイダルシリカ（日産化学工業（株）社製、スノーテックスＳＴ−Ｎ、粒径約２０ｎｍ）１質量％水溶液に７０℃で１４秒間浸せきしてから水洗した。
【０１６６】
（１０）親水性表面処理
３号ケイ酸ナトリウム濃度２．５質量％の水溶液で７０℃で１２秒間処理して、親水性表面処理を行った。
その後、水洗し、乾燥してアルミニウム支持体を得た。
【０１６７】
親水性皮膜形成方法（ｂ）
上記（７）において陽極酸化時間を１２０秒とし、また上記（８）において浸せき時間を１２０秒とした以外は、親水性皮膜形成方法（ａ）と同様の処理を行った。
【０１６８】
親水性皮膜形成方法（ｃ）
上記親水性皮膜形成方法（ａ）の（７）陽極酸化処理の変りに以下の処理を行った。
硫酸濃度１７０ｇ／Ｌ（アルミニウムイオン０．５質量％を含む。）、電流密度５Ａ／ｄｍ^２、温度３０℃、７０秒の条件でアルミニウム板の陽極酸化処理を行い水洗した。次にｐＨ１３、液温３０℃の水酸化ナトリウム水溶液に３０秒間浸せきしてから、水洗した。
ついで、上記親水性皮膜形成方法（ａ）の（９）および（１０）の処理を行った。
【０１６９】
親水性皮膜形成方法（ｄ）
上記（７）において陽極酸化時間を１２０秒とし、また上記（８）において浸せき時間を１８０秒として以外は、親水性皮膜形成方法（ａ）と同様の処理を行った。
【０１７０】
親水性皮膜形成方法（ｅ）
上記親水性皮膜形成方法（ｃ）において、水酸化ナトリウム水溶液による処理を行わなかった以外は、親水性皮膜形成方法（ｃ）と同様の処理を行った。
【０１７１】
２．皮膜の膜厚方向の熱伝導率の測定
上記で得られたアルミニウム支持体の皮膜の膜厚方向の熱伝導率を、以下の方法により測定した。
初めに、実施例および比較例の各アルミニウム支持体と膜厚のみが異なるアルミニウム支持体を、各実施例および比較例について、それぞれ２種類ずつ作成した。つまり、上記親水性皮膜形成方法における陽極酸化時間を、０．５倍、２倍にし、それ以外は各アルミニウム支持体と同様にして膜厚のみが異なるアルミニウム支持体を作成した。
つぎに、膜厚のみが異なる３種類のアルミニウム支持体を、図３に示した装置での測定に供し、下記式［１］から、皮膜の膜厚方向の熱伝導率を算出した。なお、測定は試料上の異なる５点で行い、その平均値を用いた。
結果を第２表および第３表に示す。
【０１７２】
【数２】

【０１７３】
３．ＡＤ量（陽極酸化皮膜の単位面積あたりの質量）の測定
アルミニウム支持体をＪＩＳ　Ｈ８６８８−１９９８の規定に準じて親水性層（陽極酸化皮膜を含む。）を溶解させ、単位面積あたりの質量を測定した（通称メイソン法）。測定は、２０ｃｍ×１０ｃｍの試験片を５枚用いて行い、その平均値をＡＤ量とした。標準偏差は０．０３以下であった。
結果を第２表および第３表に示す。
【０１７４】
４．親水性皮膜の厚さ（ｔ）の測定
アルミニウム基板を折り曲げて、折り曲げた際に発生したひび割れ部分の側面（通常破断面）を、超高分解能ＳＥＭ（日立Ｓ−９００）を使用して観察した。観察は、１２ｋＶという比較的低加速電圧で、導電性を付与する蒸着処理等を施すことなしに、５００００倍の倍率で行った。５０個所の断面を無作為抽出して得た測定値の平均値を親水性皮膜の厚さ（ｔ）とした。標準偏差誤差は、±１０％以下であった。
結果を第２表および第３表に示す。
【０１７５】
５．密度の測定
上記８および９で得られたＡＤ量（ｍ）および親水性皮膜の厚さ（ｔ）から、次式により親水性層（陽極酸化皮膜を含む。）の密度（ｄ）を求めた。
ｄ［ｇ／ｃｍ^３］＝ｍ［ｇ／ｍ^２］／ｔ［μｍ］
結果を第２表および第３表に示す。
【０１７６】
６．空隙率の測定
上記で求めた密度（ｄ）から、次式により親水性層（陽極酸化皮膜を含む。）の空隙率を求めた。
空隙率（％）＝（１−（ｄ／３．９８））×１００
なお、３．９８は、日本化学会編「化学便覧」（丸善）による酸化アルミニウムの密度（ｇ／ｃｍ^３）である。
結果を第２表および第３表に示す。
【０１７７】
７．Ｓｉ量の測定
アルミニウム支持体の表面のＳｉ量を蛍光Ｘ線分析装置を用いて検量線法により測定した。検量線を作成するための標準試料としては、既知量のＳｉ原子を含むケイ酸ナトリウム水溶液を、アルミニウム基板の上の３０ｍｍφの面積内に均一に滴下した後に乾燥させたものを用いた。
Ｓｉの蛍光Ｘ線分析の条件を以下に示す。
蛍光Ｘ線分析装置：理学電機工業社製ＲＩＸ３０００、Ｘ線管球：Ｒｈ、測定スペクトル：Ｓｉ−Ｋα、管電圧：５０ｋＶ、管電流：５０ｍＡ、スリット：ＣＯＡＲＳＥ、分光結晶：ＲＸ４、検出器：Ｆ−ＰＣ、分析面積：３０ｍｍφ、ピーク位置（２θ）：１４４．７５ｄｅｇ．、バックグランド（２θ）：１４０．７０ｄｅｇ．および１４６．８５ｄｅｇ．、積算時間：８０秒／ｓａｍｐｌｅ
結果を第２表および第３表に示す。
【０１７８】
８．平版印刷版原版の作製
上記で得られた各アルミニウム支持体に、下記組成の下塗層（第２表および第３表において中間層と表記する）、感光層を設けて平版印刷版原版とした。
アルミニウム支持体上に、下記組成の下塗液を塗布し、８０℃で１５秒間乾燥し、塗膜を形成させた。乾燥後の塗膜の被覆量は１５ｍｇ／ｍ^２であった。
＜下塗液組成＞
下記高分子化合物　　０．３ｇ
メタノール　　　１００　　ｇ
水　　　　　　　　　１　　ｇ
【０１７９】
【化２】

【０１８０】
更に、下記組成の感光層塗布液１を調製し、下塗りしたアルミニウム支持体に、この感光層塗布液１をバーコーターを用いて、乾燥後の塗布量（感光層塗布量）が１．０ｇ／ｍ^２になるよう塗布し、乾燥して感光層を形成させ、平版印刷版を得た。
【０１８１】

【０１８２】
【化３】

【０１８３】
＜特定の共重合体１＞
撹拌機、冷却管および滴下ロートを備えた５００ｍＬ容の三つ口フラスコに、メタクリル酸３１．０ｇ（０．３６ｍｏｌ）、クロロギ酸エチル３９．ｌｇ（０．３６ｍｏｌ）およびアセトニトリル２００ｍＬを入れ、氷水浴で冷却しながら混合物を撹拌した。この混合物にトリエチルアミン３６．４ｇ（０．３６ｍｏｌ）を約１時間かけて滴下ロートにより滴下した。滴下終了後、氷水浴を取り去り、室温下で３０分間混合物を撹拌した。
【０１８４】
この反応混合物に、ｐ−アミノベンゼンスルホンアミド５１．７ｇ（０．３０ｍｏｌ）を加え、油浴にて７０℃に温めながら混合物を１時間撹拌した。反応終了後、この混合物を水１Ｌにこの水を撹拌しながら投入し、３０分間得られた混合物を撹拌した。この混合物をろ過して析出物を取り出し、これを水５００ｍＬでスラリーにした後、このスラリーをろ過し、得られた固体を乾燥することによりＮ−（ｐ−アミノスルホニルフェニル）メタクリルアミドの白色固体が得られた（収量４６．９ｇ）。
【０１８５】
つぎに、撹拌機、冷却管および滴下ロートを備えた２０ｍＬ容の三つ口フラスコに、Ｎ−（ｐ−アミノスルホニルフェニル）メタクリルアミド４．６１ｇ（０．０１９２ｍｏｌ）、メタクリル酸エチル２．９４ｇ（０．０２５８ｍｏｌ）、アクリロニトリル０．８０ｇ（０．０１５ｍｏｌ）およびＮ，Ｎ−ジメチルアセトアミド２０ｇを入れ、湯水浴により６５℃に加熱しながら混合物を撹拌した。この混合物に「Ｖ−６５」（和光純薬社製）０．１５ｇを加え、６５℃に保ちながら窒素気流下で、混合物を２時間撹拌した。この反応混合物に更にＮ−（ｐ−アミノスルホニルフェニル）メタクリルアミド４．６１ｇ、メタクリル酸エチル２．９４ｇ、アクリロニトリル０．８０ｇ、Ｎ，Ｎ−ジメチルアセトアミドおよび「Ｖ−６５」０．１５ｇの混合物を２時間かけて滴下ロートにより滴下した。滴下終了後、更に、得られた混合物を６５℃で２時間撹拌した。反応終了後、メタノール４０ｇを混合物に加え、冷却し、得られた混合物を水２Ｌにこの水を撹拌しながら投入し、３０分混合物を撹拌した後、析出物をろ過により取り出し、乾燥することにより１５ｇの白色固体の特定の共重合体１を得た。
得られた特定の共重合体１の重量平均分子量をゲルパーミエーションクロマトグラフィーにより測定したところ、５３，０００（ポリスチレン標準）であった。
【０１８６】
Ｖ−６５
【化４】

【０１８７】
以下の各測定および各試験を行い、その結果を第２表および第３表に示した。
【０１８８】
９．中波の平均開口径
平版印刷版をγブチルラクトンで感光層を溶解除去して支持体を露出した後、支持体表面を垂直方向から倍率１００００倍でＳＥＭ観察し、撮影した写真上でピットの直径を３０点測定しその平均値を平均開口径とした。この際、日立製作所Ｓ−９００を使用した。
【０１８９】
１０．大波の平均波長
平版印刷版をγブチルラクトンで感光層を溶解除去して支持体を露出した後、日本電子製のＴ−２０型走査電子顕微鏡を用いて、表面を倍率２０００倍で観察し、各大波の凹凸成分を水平方向とその直角方向を各３０点読取りその平均値を平均波長とした。
【０１９０】
１１．中波構造の開口径に対する深さの比の平均
中波構造の開口径に対する深さの比の平均は、高分解能ＳＥＭを用いて支持体の破断面を倍率５００００倍で撮影し、得られたＳＥＭ写真において２０個抽出し、開口径と深さとを読み取って比を求めて平均値を算出した。
【０１９１】
１２．平版印刷版の感度の評価
上記のようにして得られた平版印刷版をＣＲＥＯ社製ＴｒｅｎｎｄＳｅｔｔｅｒ３２４４を用いて版面エネルギー量を、露光出力を変えて露光した後、下記に示す現像方法により現像処理を行い、残膜量が急激に増える直前の、即ち、画像形成可能な最小のレーザ光の版面エネルギーを感度の指標とした。
現像方法：富士フィルム製ＰＳ版用現像液ＤＴ−１（Ｓｉを含まない現像液）を、自動現像機９００ＮＰを用いて標準使用条件で現像処理を行った。
【０１９２】
１３．耐汚れ性評価
ＣＲＥＯ社製ＴｒｅｎｎｄＳｅｔｔｅｒ３２４４を用いて版面エネルギー量１４０ｍＪ／ｃｍ^２で像様露光し、その後、上記１２と同様の現像方法で現像した。三菱ダイヤ型Ｆ２印刷機を用いて、ＤＩＣ　ＧＥＯＳ紅（ｓ）にて印刷し１万枚印刷した後でのブランケットの汚れを目視で評価した。汚れの少ない方から順に、◎、○◎、○、△、×の５段階で評価した。
【０１９３】
１４．耐刷性評価
汚れ評価と同様に印刷した後、小森コーポレーションのリスロン印刷機にて印刷を行った。インキはＤＩＣ　ＧＥＯＳ墨（Ｎ）を使用した。印刷物上でベタ部分の濃度が薄くなり始める印刷枚数をもって耐刷性とした。
【０１９４】
【表２】

【０１９５】
【表３】

【０１９６】
【表４】

【０１９７】
【表５】

【０１９８】
【発明の効果】
本発明のアルミニウム支持体は、膜厚方向の熱伝導率が０．０５〜０．５Ｗ／（ｍ・Ｋ）である親水性皮膜を有するので、赤外線レーザーの露光量が低いときや、現像液の液感が低いときでも、現像液に対する溶解性が高くなる。その結果、感度が高く、現像ラチチュードが広く、低露光時にも残膜が少なく、非画像部の汚れが生じにくい。
特に、本発明の平版印刷版原版は、特定の平均波長（開口径）を有する構造を重畳した二重構造の砂目形状を有するアルミニウム支持体に、特定の範囲の熱伝導率を有する親水性皮膜を設けた後、特定の感熱層を設けることにより、熱を効率よく画像形成に利用することができ、感度が高く、高耐刷性を示し、非画像部の汚れが生じにくい感熱性の平版印刷版原版である。
【図面の簡単な説明】
【図１】本発明に好適に用いられる交流を用いた電気化学的粗面化処理に用いる台形波の一例を示す波形図である。
【図２】本発明に好適に用いられる電気化学的粗面化処理におけるラジアル型セルの一例を示す側面図である。
【図３】本発明の平版印刷版原版の親水性皮膜の膜厚方向の熱伝導率の測定に用いることができるサーモコンパレータの概略図である。
【符号の説明】
１１　アルミニウム板
１２　ラジアルドラムローラ
１３ａ、１３ｂ　主極
１４　酸性水溶液
１５　溶液供給口
１６　スリット
１７　溶液通路
１８　補助陽極
１９ａ、１９ｂ　サイリスタ
２０　交流電源
２１　主電解槽
２２　補助陽極槽
３０　サーモコンパレータ
３１　チップ
３２　リザーバ
３３　電熱ヒーター
３４　加熱用ジャケット
３５　熱電対
３６　ヒートシンク
３７　皮膜
３８　金属基体
３９　接触式温度計
４０　チップ先端温度記録計
４１　ヒートシンク温度記録計
４２　リザーバ温度記録計[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lithographic printing plate precursor having high printing durability, high sensitivity, and good stain resistance during printing (hereinafter referred to as “stain resistance”), and more specifically, aluminum having a specific grain shape. The present invention relates to a lithographic printing plate precursor having a thermal positive thermosensitive layer provided with a hydrophilic film having a low thermal conductivity on a support and having high printing durability, high sensitivity and excellent stain resistance.
[0002]
[Prior art]
In recent years, with the development of image forming technology, it is possible to scan a plate with a narrowly focused laser beam and form a text document, an image document, etc. directly on the plate surface, and directly make a plate without using a film document. It is becoming.
In the so-called thermal positive type lithographic printing plate precursor, which causes the alkali solubilization of the recording layer by causing photothermal conversion in the recording layer by laser light irradiation and forms a positive image, in the recording layer by laser exposure as an image forming principle The difference in the degree of on / off of solubilization of alkali in the exposed / unexposed part is small because the subtle changes in the intermolecular interaction of the binder are utilized. For this reason, for the purpose of obtaining a clear discrimination that can withstand practical use, a means for forming a recording layer structure in which a poorly surface-solubilizing layer for a developer is provided as the uppermost layer of the recording layer to suppress development solubility in the unexposed area. Is used.
[0003]
However, when the surface-solubilized layer is damaged for some reason, even the portion that originally becomes the image portion is likely to be dissolved in the developer. In other words, it has become a printing plate that is very easily damaged. For this reason, scratch-like image loss may occur due to slight contact such as bumping when handling the printing plate, slight rubbing on the interleaf, and finger contact with the plate surface. The current situation is difficult. In order to improve the susceptibility to scratches, attempts have been made to lower the friction coefficient by providing a fluorosurfactant or wax agent layer on the surface of the recording layer, but this is not yet a sufficient measure. .
[0004]
On the other hand, in order to increase discrimination, it has also been studied to improve developability, and a hydrophilic layer or an alkali-soluble undercoat layer (alkali-solubilized layer) by silicate treatment is provided between the recording layer and the support. Has been tried. According to these methods, developability can be ensured to some extent, and development latitude in a practical range can be obtained, but adhesion between the recording layer and the support is lowered. In addition, in order to improve the resistance to dirt, smoothing the shape of the support surface to eliminate the deep recesses present on the support surface that cause residual film significantly reduces the printing durability. It becomes unusable for practical use. For this reason, a lithographic printing plate precursor that is satisfactory in terms of ease of printing, which has excellent printing durability and is resistant to staining, has not yet been realized.
[0005]
In addition, the infrared absorber present in the thermosensitive layer exhibits its photothermal conversion action and generates heat upon exposure, and the exposed portion of the thermosensitive layer is alkali-solubilized by the heat to form a positive image (infrared type) The laser positive type) lithographic printing plate precursor also has the following problems.
[0006]
That is, in such thermal type image formation, heat is generated by the photothermal conversion substance in the heat sensitive layer by laser light irradiation, and this heat causes an image formation reaction. In the formed aluminum support, the heat conductivity of the support is extremely higher than that of the heat-sensitive layer, so that the heat generated near the interface between the heat-sensitive layer and the support is not sufficiently used for image formation. As a result, the following occurs at the heat-sensitive layer support interface.
[0007]
In the positive type heat-sensitive layer, if the heat is diffused into the support and the alkali solubilization reaction becomes insufficient, there is a problem of low sensitivity that a residual film is generated in the original non-image part. This is an essential problem of the mold type thermosensitive layer. In addition, in such a thermal positive type lithographic printing plate precursor, an infrared absorber having a photothermal conversion function is essential, but these have a relatively low molecular weight and thus have low solubility, and are caused by anodization. Since it is difficult to remove by adsorption to the microscopic opening, there is a problem that a residual film is likely to be generated in the development process using an alkaline developer.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a heat-sensitive lithographic printing plate precursor that overcomes the disadvantages of the prior art described above. That is, it is an object of the present invention to provide a heat-sensitive lithographic printing plate precursor that can efficiently use heat for image formation, has high sensitivity, exhibits high printing durability, and hardly causes stains on non-image areas.
[0009]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that the above object can be achieved by combining an aluminum support having a specific grain shape and a hydrophilic film having a specific thermal conductivity with a heat sensitive layer. That is, a hydrophilic film having a specific range of thermal conductivity is provided on an aluminum support having a grained shape with a superposed structure having a specific average wavelength (aperture diameter), and a thermal type image recording layer is provided thereon. Thus, the inventors have found that the above object can be achieved and completed the present invention.
[0010]
That is, the present invention has a grained shape of a superposed structure including a large wave structure with an average wavelength of 2 to 30 μm and a medium wave structure with an average opening diameter of 0.05 to 5 μm, and has an average opening diameter of 0.05 to 5 μm. On an aluminum support having an average ratio of the depth to the opening diameter of the wave structure of 0.1 to 1.0; a hydrophilic film having a thermal conductivity of 0.05 to 0.5 W / (m · K) is provided. A lithographic printing plate precursor comprising a heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared absorbing dye and having increased solubility in an alkaline aqueous solution by heating;
[0011]
Further, the present invention has a grained shape of a superposed structure including a large wave structure with an average wavelength of 2 to 30 μm and a medium wave structure with an average opening diameter of 0.05 to 5 μm, and has an average opening diameter of 0.05 to 5 μm. On an aluminum support having an average ratio of depth to opening diameter of the wave structure of 0.1 to 1.0; density 1.0 to 3.2 g / cm ³ Or after providing a hydrophilic film having a porosity of 20 to 70%; a lithographic plate comprising a heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared-absorbing dye and having increased solubility in an alkaline aqueous solution upon heating Providing a printing plate master.
[0012]
In one preferred embodiment, the hydrophilic film is an anodized film formed by anodization.
[0013]
In the present invention, it is preferable that the hydrophilic film is further treated with an alkali metal silicate.
The amount of Si atoms adsorbed by the alkali metal silicate treatment is 0.1 to 15.0 mg / m. ² It is more preferable that
[0014]
In the present invention, the heat sensitive layer is composed of a lower layer provided on a support on which a hydrophilic film is formed and an upper heat sensitive layer, and a polymer material having an acid group is provided in the heat sensitive layer and / or the lower layer. preferable.
[0015]
In the present invention, the lithographic printing plate precursor is preferably developed with a developer containing at least one compound selected from the group consisting of silicates and saccharides.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
[Aluminum support]
<Aluminum plate>
The metal substrate used in the aluminum support which is the lithographic printing plate support of the present invention is an aluminum substrate, and the aluminum plate used as the aluminum substrate is a metal whose main component is dimensionally stable aluminum. Made of aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic film or paper on which aluminum or an aluminum alloy is laminated or vapor-deposited can also be used. Furthermore, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 can also be used.
[0017]
The aluminum plate used in the present invention is not particularly limited, but a pure aluminum plate is preferably used. Since completely pure aluminum is difficult to manufacture in terms of scouring techniques, it may be used that contains slightly different elements. For example, known materials described in Aluminum Handbook 4th Edition (Light Metal Association (1990)), specifically, JIS1050 material, JIS1100 material, JIS3003 material, JIS3103 material, JIS3005 material, etc. can be used. The aluminum (Al) content is 95-99.4 mass%, and iron (Fe), silicon (Si), copper (Cu), magnesium (Mg), manganese (Mn), zinc (Zn) Further, an aluminum plate using an aluminum alloy, a scrap aluminum material, or a secondary metal containing at least five of chromium (Cr) and titanium (Ti) within a range described later can also be used.
[0018]
In the present invention, an aluminum plate having an Al content of 95 to 99.4% by mass, which is cost-effective, can also be used. If the Al content exceeds 99.4% by mass, the allowable amount of impurities decreases, which may reduce the cost reduction effect. Further, if the Al content is less than 95% by mass, it contains a large amount of impurities, which may cause defects such as cracks during rolling. The Al content is more preferably 95 to 99% by mass, and particularly preferably 95 to 97% by mass.
[0019]
The content of Fe is preferably 0.05 to 1.0% by mass. Fe is an element contained in the new metal in the range of about 0.1 to 0.2% by mass, and the amount dissolved in Al is small, and most remains as an intermetallic compound. If the Fe content exceeds 1.0% by mass, cracking is likely to occur during rolling, and if it is less than 0.05% by mass, the cost increases, which is not preferable. A more preferable Fe content is 0.2 to 0.5 mass%.
[0020]
The Si content is preferably 0.03 to 1.0 mass%. Si is an element contained in a large amount in scrap of JIS 2000, 4000, and 6000 materials. Si is also an element contained in the new metal in the range of about 0.03 to 0.1% by mass, and exists in a solid solution state in Al or as an intermetallic compound. When the aluminum plate is heated during the manufacturing process of the support, Si that has been dissolved may precipitate as elemental Si. It is known that simple Si and FeSi-based intermetallic compounds adversely affect the resistance to severe ink stains. Here, “severe ink stains” appear on printed paper as a result of ink becoming more likely to adhere to the non-image area surface portion of a lithographic printing plate when printing is interrupted many times. This refers to dot-like or annular dirt. If the Si content exceeds 1.0% by mass, for example, this may not be completely removed by the treatment with sulfuric acid (desmut treatment) described later. The cost increases because it requires money, which is not realistic. A more preferable Si content is 0.04 to 0.15 mass%.
[0021]
The Cu content is preferably 0 to 1.0% by mass. Cu is an element contained in a lot of scraps of JIS 2000 and 4000 materials. Cu is relatively easily dissolved in Al. If the Cu content exceeds 1.0% by mass, for example, this may not be completely removed by treatment with sulfuric acid to be described later, resulting in poor graininess. A more preferable Cu content is 0 to 0.1% by mass.
[0022]
The content of Mg is preferably 0 to 1.5% by mass. Mg is an element contained in a large amount in scraps of JIS 2000, 3000, 5000, and 7000 materials. In particular, it is one of the main impurity metals contained in scrap materials because it is contained in a large amount in can end materials. Mg is relatively easy to dissolve in Al and forms an intermetallic compound with Si. If the Mg content exceeds 1.5% by mass, the strength of the aluminum plate becomes too high.
[0023]
The Mn content is preferably 0 to 1.5% by mass. Mn is an element contained in a large amount in scrap of JIS 3000 series materials. Mn is one of the main impurity metals contained in the scrap material because it is contained in the can body material. Mn is relatively easily dissolved in Al and forms an intermetallic compound with Al, Fe, and Si. If the Mn content exceeds 1.5% by mass, the strength of the aluminum plate will be too high.
[0024]
The Zn content is preferably 0 to 0.5% by mass. Zn is an element that is particularly abundant in JIS7000 series scrap. Zn is relatively easily dissolved in Al. If the Zn content exceeds 0.5% by mass, the uniformity of graininess deteriorates.
[0025]
The Ti content is preferably 0.003 to 0.5 mass%. Ti is an element usually added in an amount of 0.01 to 0.04% by mass as a crystal refining material. JIS 5000 series, 6000 series, and 7000 series scraps contain relatively large amounts of impurity metals. When the Ti content exceeds 0.5% by mass, there is a problem that the grain is dissolved and the printing durability is deteriorated.
A more preferable Ti content is 0.003 to 0.1% by mass.
[0026]
The aluminum plate used in the present invention is appropriately cast using the above-mentioned raw materials and subjected to appropriate rolling treatment or heat treatment to have a thickness of, for example, 0.1 to 0.7 mm, and flatness as necessary. Manufactured with straightening treatment. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the user's desire.
In addition, as a manufacturing method of the said aluminum plate, the method which abbreviate | omitted soaking and / or annealing treatment from DC casting method, DC casting method, and the continuous casting method can be used, for example.
[0027]
<Surface grain shape>
The aluminum support of the present invention is characterized in that it has a grained shape of a superposed structure including a large wave structure with an average wavelength of 2 to 30 μm and a medium wave structure with an average opening diameter of 0.05 to 5 μm on the surface.
When the double structure having a specific average opening diameter is used, the surface area of the aluminum or aluminum alloy plate is increased, the adhesion with the anodized film, the image recording layer and the like is improved, and the printing durability is very excellent.
[0028]
In the present invention, the medium wave structure having an average opening diameter of 0.05 to 5 μm has a function of holding the image recording layer mainly by an anchoring effect and imparting printing durability. If the average opening diameter of the pits having the medium wave structure is less than 0.05 μm, the adhesion with the image recording layer provided on the upper layer may be lowered, and the printing durability of the lithographic printing plate may be lowered. Further, when the average opening diameter of the pits having the medium wave structure exceeds 5 μm, the number of pit boundary portions serving as anchors is reduced, so that the printing durability may also be lowered.
The average opening diameter of the medium wave structure is preferably 0.05 to 3 μm, and more preferably 0.05 to 2 μm.
[0029]
For this medium wave structure, not only the opening diameter of the pit but also the depth of the pit can be controlled to obtain even better stain resistance. That is, the average of the ratio of the depth to the opening diameter of the medium wave structure is preferably 0.1 to 1.0. As a result, the uniformly formed water film is reliably held on the surface, and the stain resistance of the surface of the non-image part is maintained for a long time.
[0030]
The large wave structure having an average wavelength of 2 to 30 μm has an effect of increasing the water retention amount on the surface of the non-image portion of the planographic printing plate. The more water is retained on the surface, the less the surface of the non-image area is affected by contamination in the atmosphere, and a non-image area that is less likely to get dirty even when the plate is left in the middle of printing can be obtained. Further, when the large wave structure is superimposed, it becomes easy to visually confirm the amount of dampening water given to the printing plate during printing. That is, the plate inspection property of the planographic printing plate is excellent. If the average wavelength of the large wave structure is less than 2 μm, there may be no difference from the medium wave structure. If the average wavelength of the large wave structure exceeds 30 μm, the exposed non-image area may appear glaring after exposure and development, and the plate inspection property may be impaired. The average wavelength of the large wave structure is preferably 4 to 15 μm.
[0031]
In the aluminum support of the present invention, the average aperture diameter of the surface medium-wave structure, the average ratio of the depth to the aperture diameter, and the method for measuring the average wavelength of the large waves are as follows.
[0032]
(1) Average opening diameter of medium wave structure
The surface of the support was photographed at a magnification of 10,000 times from directly above using an electron microscope, and at least 50 medium-wave structure pits (medium-wave pits) in which the periphery of the pits are connected in a ring shape in the obtained electron micrograph. Extract, read the diameter and use it as the opening diameter, and calculate the average opening diameter. The same method is used for a structure with a large wave structure superimposed.
In addition, in order to suppress variation in measurement, it is possible to perform equivalent circle diameter measurement using commercially available image analysis software. In this case, the electron micrograph is captured by a scanner, digitized, and binarized by software, and then an equivalent circle diameter is obtained.
As a result of measurement by the present inventor, the result of visual measurement and the result of digital processing showed almost the same value. The same applies to the structure in which the large wave structure is superimposed.
[0033]
(2) Average ratio of depth to opening diameter of medium wave structure
The average ratio of the depth of the medium-wave structure to the opening diameter was obtained by photographing the fracture surface of the support at a magnification of 50000 times using a high-resolution SEM, and extracting at least 20 medium-wave pits in the obtained SEM photograph, An average value is calculated by reading the opening diameter and depth and determining the ratio.
[0034]
(3) Average wavelength of large wave structure
Using a T-20 scanning electron microscope made by JEOL, the surface was photographed at a magnification of 2000 times, each large wave of the concavo-convex component was read at 30 points in the horizontal direction and the right angle direction, and the average value of the large wave structure Average wavelength.
[0035]
The aluminum support of the present invention is obtained by subjecting the aluminum plate to a surface roughening treatment and further forming a specific hydrophilic film. In the production process of the aluminum support of the present invention, the aluminum support is roughened. Various processes other than treatment and formation of a hydrophilic film may be included.
[0036]
The above aluminum plate is a degreasing process for removing the adhering rolling oil, a desmutting process for dissolving the smut on the surface of the aluminum plate, a roughening process for roughening the surface of the aluminum plate, and oxidizing the surface of the aluminum plate. It is preferable to be a support through an anodic oxidation process or the like covered with a film.
The production process of the aluminum support of the present invention preferably includes a roughening treatment (electrochemical roughening treatment) in which an aluminum plate is electrochemically roughened using an alternating current in an acidic aqueous solution.
In addition, the manufacturing process of the aluminum support of the present invention includes an aluminum plate that combines mechanical roughening treatment, chemical etching treatment in an acid or alkaline aqueous solution, in addition to the electrochemical roughening treatment. A surface treatment step may be included. The production process such as the roughening treatment of the aluminum support of the present invention may be a continuous method or an intermittent method, but it is preferable to use a continuous method industrially.
[0037]
<Roughening treatment (graining treatment)>
The aluminum plate is roughened (grained) to a more preferable shape.
Examples of the graining method include mechanical graining (mechanical surface roughening), chemical etching, and electrolytic grain as described in JP-A-56-28893. In addition, electrochemical graining (electrochemical roughening, electrolytic graining), which is electrochemically grained in hydrochloric acid electrolyte or nitric acid electrolyte, or the aluminum surface is scratched with metal wire Mechanical graining methods (mechanical roughening treatment) such as brush grain method, ball grain method to grain the aluminum surface with abrasive balls and abrasives, brush grain method to grain the surface with nylon brush and abrasives, etc. Can be used. These graining methods can be used alone or in combination. For example, a combination of a mechanical surface roughening treatment with a nylon brush and an abrasive and an electrolytic surface roughening treatment with a hydrochloric acid electrolytic solution or a nitric acid electrolytic solution, or a combination of a plurality of electrolytic surface roughening treatments may be mentioned. Of these, electrochemical surface roughening is preferred. Moreover, it is also preferable to perform a mechanical surface roughening process and an electrochemical surface roughening process in combination, and it is particularly preferable to perform an electrochemical surface roughening process after the mechanical surface roughening process.
[0038]
(Mechanical roughening treatment)
The mechanical roughening treatment is a treatment for mechanically roughening the surface of the aluminum plate using a brush or the like, and is preferably performed before the electrochemical roughening treatment described above.
In a suitable mechanical surface roughening treatment, the treatment is performed with a rotating nylon brush roll having a bristle diameter of 0.07 to 0.57 mm and a slurry of an abrasive supplied to the aluminum plate surface.
[0039]
The nylon brush preferably has a low water absorption rate. For example, nylon bristle 200T manufactured by Toray Industries, Inc. (6,10-nylon, softening point: 180 ° C., melting point: 212 to 214 ° C., specific gravity: 1.08 to 1.09, Moisture content: 1.4 to 1.8 at 20 ° C. and 65% relative humidity, 2.2 to 2.8 at 20 ° C. and 100% relative humidity, dry tensile strength: 4.5 to 6 g / d, dry tensile elongation Degree: 20-35%, boiling water shrinkage: 1-4%, dry tensile resistance: 39-45 g / d, Young's modulus (dry): 380-440 kg / mm ² ) Is preferred.
[0040]
As the abrasive, known ones can be used, but silica sand, quartz, aluminum hydroxide, or a mixture thereof described in JP-A-6-135175 and JP-B-50-40047 is used. Is preferred.
[0041]
As a slurry liquid, what has a specific gravity in the range of 1.05-1.3 is preferable. Examples of the method of supplying the slurry liquid to the aluminum plate surface include a method of spraying the slurry liquid, a method of using a wire brush, and a method of transferring the surface shape of the uneven roll to the aluminum plate. Moreover, you may use the method described in Unexamined-Japanese-Patent No. 55-074898, 61-162351, 63-104889. Furthermore, as described in JP-A-9-509108, an aluminum plate in an aqueous slurry comprising a mixture of particles made of alumina and quartz at a mass ratio in the range of 95: 5 to 5:95. A method of brush polishing the surface can also be used. The average particle size of the mixture at this time is preferably in the range of 10 to 80 μm, particularly 15 to 60 μm.
[0042]
In the case of the brush grain method, the long wavelength of the surface of the aluminum support is selected by appropriately selecting the conditions such as the average particle size, maximum particle size, bristle diameter of the brush used, density, indentation pressure, etc. The average depth of the concave portion of the component (large wave) can be controlled. The recesses obtained by the brush grain method preferably have an average wavelength of 2 to 30 μm (average depth of 0.3 to 1 μm).
[0043]
(Electrochemical roughening treatment)
The electrochemical surface roughening treatment is a step of electrochemically roughening the surface of the aluminum plate in an acidic aqueous solution through an alternating current using the aluminum plate as an electrode. Is different.
In the present invention, in the electrochemical surface roughening treatment, the amount of electricity when the aluminum plate becomes the cathode, that is, the amount of electricity at the time of cathode Q _C And the amount of electricity when it becomes the anode, that is, the amount of electricity Q at the time of anode _A Ratio Q with _C / Q _A For example, uniform honeycomb pits can be generated on the surface of the aluminum plate by setting the value within a range of 0.7 to 2.5. Q _C / Q _A If it is less than 0.7, non-uniform honeycomb pits tend to be formed, and if it exceeds 2.5, non-uniform honeycomb pits tend to be formed. Q _C / Q _A Is preferably in the range of 0.7 to 1.5.
[0044]
Examples of the alternating current waveform used for the electrochemical surface roughening treatment include a sine wave, a rectangular wave, a triangular wave, and a trapezoidal wave. Among these, a rectangular wave or a trapezoidal wave is preferable. In addition, the frequency of the alternating current is preferably 30 to 200 Hz, more preferably 40 to 120 Hz, from the viewpoint of the cost of manufacturing the power supply device.
An example of a trapezoidal wave suitably used in the present invention is shown in FIG. In FIG. 1, the vertical axis indicates the current value, and the horizontal axis indicates time. Further, ta is the anode reaction time, tc is the cathode reaction time, tp and tp ′ are the time until the current value reaches the peak from 0, Ia is the current at the peak on the anode cycle side, and Ic is the peak on the cathode cycle side Indicates the current of the hour. When a trapezoidal wave is used as the waveform of the alternating current, the times tp and tp ′ until the current reaches a peak from 0 are preferably 0.1 to 2 msec, more preferably 0.3 to 1.5 msec. preferable. If tp and tp ′ are less than 0.1 msec, the impedance of the power supply circuit is affected, and a large power supply voltage is required at the rising of the current waveform, which may increase the equipment cost of the power supply. Moreover, when tp and tp 'exceed 2 msec, the influence of the trace component in acidic aqueous solution will become large, and it may become difficult to perform a uniform roughening process.
[0045]
Further, the duty of the alternating current used for the electrochemical surface roughening treatment is preferably within the range of 0.25 to 0.6 from the point of uniformly roughening the aluminum plate surface, 0.3 to More preferably, it is within the range of 0.5. The duty in the present invention refers to ta / T, where ta is the time during which the anode reaction of the aluminum plate continues in the period T of the alternating current (anode reaction time). In particular, on the surface of the aluminum plate during the cathode reaction, in addition to the formation of smut components mainly composed of aluminum hydroxide, dissolution and destruction of the oxide film occurred, and the start of the pitting reaction during the anode reaction of the next aluminum plate Therefore, the selection of the duty of the alternating current has a great effect on uniform roughening.
[0046]
In the case of a trapezoidal wave or a rectangular wave, the alternating current has a current density Iap at the peak on the anode cycle side and a current density Icp at the peak on the cathode cycle side of 10 to 200 A / dm, respectively. ² It is preferable that Icp / Iap is preferably in the range of 0.9 to 1.5.
In the electrochemical surface roughening treatment, the total amount of electricity used for the anode reaction of the aluminum plate at the time when the electrochemical surface roughening treatment is completed is 50 to 1000 C / dm. ² Is preferred. The electrochemical surface roughening treatment time is preferably 1 second to 30 minutes.
[0047]
As the acidic aqueous solution used for the electrochemical surface roughening treatment, those used for the electrochemical surface roughening treatment using a normal direct current or alternating current can be used, and among them, the acidic aqueous solution mainly composed of nitric acid. Alternatively, it is preferable to use an acidic aqueous solution mainly composed of hydrochloric acid. Here, “mainly” means that the main component is contained in the aqueous solution in an amount of 30% by mass or more, preferably 50% by mass or more based on the total components. Hereinafter, the same applies to other components.
[0048]
As the acidic aqueous solution mainly composed of nitric acid, as described above, those used for the electrochemical surface roughening treatment using a normal direct current or alternating current can be used. For example, one or more of nitric acid compounds such as aluminum nitrate, sodium nitrate, and ammonium nitrate are added to a nitric acid aqueous solution having a nitric acid concentration of 5 to 15 g / L at a concentration from 0.01 g / L to saturation. be able to. In the acidic aqueous solution mainly composed of nitric acid, a metal contained in an aluminum alloy such as iron, copper, manganese, nickel, titanium, magnesium, or silicon may be dissolved.
[0049]
As the acidic aqueous solution mainly composed of nitric acid, nitric acid, aluminum salt, and nitrate are contained, and aluminum ion is 1 to 15 g / L, preferably 1 to 10 g / L, and ammonium ion is 10 to 300 ppm. Thus, it is preferable to use a solution obtained by adding aluminum nitrate and ammonium nitrate to an aqueous nitric acid solution having a nitric acid concentration of 5 to 15 g / L. The aluminum ions and ammonium ions increase spontaneously during the electrochemical surface roughening treatment. Moreover, it is preferable that the liquid temperature in this case is 10-95 degreeC, It is more preferable that it is 20-90 degreeC, It is especially preferable that it is 40-80 degreeC.
[0050]
As the acidic aqueous solution mainly composed of hydrochloric acid, those used for the electrochemical surface roughening treatment using a normal direct current or an alternating current can be used as described above. For example, 1 g / L of one or more of hydrochloric acid or nitric acid compound having a nitrate ion such as aluminum nitrate, sodium nitrate, ammonium nitrate, or the like, or a chloride ion such as aluminum chloride, sodium chloride, ammonium chloride is added to a 1-100 g / L hydrochloric acid aqueous solution. It can be used by adding up to saturation. Moreover, the compound which forms a complex with copper can also be added in the ratio of 1-200 g / L. In an aqueous solution mainly composed of hydrochloric acid, a metal contained in an aluminum alloy such as iron, copper, manganese, nickel, titanium, magnesium, or silica may be dissolved. Hypochlorous acid or hydrogen peroxide may be added at 1 to 100 g / L.
[0051]
An aqueous solution in which aluminum ions (aluminum chloride) are added to an aqueous solution containing a liquid temperature of 15 to 50 ° C. and 2 to 15 g / L of hydrochloric acid to make aluminum ions 3 to 50 g / L is particularly preferable. As an additive, an apparatus, a power source, a current density, a flow rate, and a temperature in an aqueous solution mainly containing hydrochloric acid, those used for known electrochemical surface roughening can be used.
[0052]
By electrochemical roughening after mechanical roughening, a double pit structure having the above-described characteristics can be formed.
The provided pits have the effect of improving the resistance to smearing of the non-image area of the printing plate and the printing durability. In the electrochemical treatment, the amount of electricity necessary to provide sufficient pits on the surface, that is, the product of the current and the time during which the current is applied is an important condition in electrochemical roughening. From the viewpoint of energy saving, it is desirable that sufficient pits can be formed with a smaller amount of electricity. The surface roughness after the roughening treatment is such that the arithmetic average roughness (Ra) measured at a cut-off value of 0.8 mm and an evaluation length of 3.0 mm in accordance with JIS B0601-1994 is 0.2-0. It is preferably 5 μm.
[0053]
In the electrochemical surface roughening treatment, a known electrolytic device such as a vertical type, a flat type, or a radial type can be used, but a radial type electrolytic device as described in JP-A-5-195300 is used. Particularly preferred.
FIG. 2 is a schematic view of a radial type electrolyzer suitably used in the present invention. In FIG. 2, 11 is an aluminum plate, 12 is a radial drum roller, 13a and 13b are main electrodes, 14 is an acidic aqueous solution, 15 is a solution supply port, 16 is a slit, 17 is a solution passage, 18 is an auxiliary anode, 19a and 19b. Is a thyristor, 20 is an AC power source, 21 is a main electrolytic cell, and 22 is an auxiliary anode cell. In FIG. 2, the radial electrolysis apparatus has an aluminum plate 11 wound around a radial drum roller 12 disposed in a main electrolytic cell 21 and electrolyzed by main poles 13 a and 13 b connected to an AC power source 20 in the course of conveyance. Is done. The acidic aqueous solution 14 is supplied from the solution supply port 15 through the slit 16 to the solution passage 17 between the radial drum roller 12 and the main poles 13a and 13b.
Next, the aluminum plate 11 treated in the main electrolytic cell 21 is subjected to electrolytic treatment in the auxiliary anode cell 22. An auxiliary anode 18 is disposed opposite to the aluminum plate 11 in the auxiliary anode tank 22, and the acidic aqueous solution 14 is supplied so as to flow between the auxiliary anode 18 and the aluminum plate 11. Note that the current flowing through the auxiliary electrode is controlled by the thyristors 19a and 19b.
[0054]
The main electrodes 13a and 13b can be selected from carbon, platinum, titanium, niobium, zirconium, stainless steel, electrodes used for cathodes for fuel cells, etc., and carbon is particularly preferable. As the carbon, commercially available impervious graphite for chemical devices, resin cored graphite, and the like can be used.
The auxiliary anode 18 can be selected from known oxygen generating electrodes such as ferrite, iridium oxide, platinum, or platinum clad or plated with a valve metal such as titanium, niobium or zirconium.
[0055]
The supply direction of the acidic aqueous solution passing through the main electrolytic cell 21 and the auxiliary anode cell 22 may be parallel to the progress of the aluminum plate 11 or a counter. The relative flow rate of the acidic aqueous solution with respect to the aluminum plate is preferably 10 to 1000 cm / sec.
One electrolysis apparatus can be connected to one or more AC power supplies. Two or more electrolysis devices may be used, and electrolysis conditions in each device may be the same or different.
In addition, after the electrolytic treatment is completed, it is preferable to perform liquid drainage by a nip roller and water washing by spraying so that the treatment liquid is not taken out to the next process.
[0056]
In the case of using the above electrolyzer, for example, (i) the conductivity of the acid aqueous solution and (ii) the ultrasonic wave propagation velocity ( iii) Based on the nitric acid and aluminum ion concentrations determined from the temperature, add while adjusting the addition amount of nitric acid and water, and sequentially overflow the acidic aqueous solution with the same volume as the addition volume of nitric acid and water from the electrolyzer. It is preferable to keep the concentration of the acidic aqueous solution constant by discharging.
[0057]
Next, the surface treatments such as chemical etching treatment and desmut treatment in acidic aqueous solution or alkaline aqueous solution will be described in order. The surface treatment is performed before the electrochemical roughening treatment or after the electrochemical roughening treatment and before an anodic oxidation treatment described later. However, the description of each surface treatment below is an exemplification, and the present invention is not limited to the contents of each surface treatment below. In addition, the following treatments including the surface treatment are optionally performed.
[0058]
(Alkaline etching treatment)
The alkali etching treatment is a treatment for chemically etching the surface of the aluminum plate in an alkaline aqueous solution, and is preferably performed before and after the electrochemical roughening treatment. Moreover, when performing a mechanical surface roughening process before an electrochemical surface roughening process, it is preferable to carry out after a mechanical surface roughening process. The alkali etching treatment is more advantageous than the acid etching treatment described later because the fine structure can be destroyed in a short time.
Examples of the alkaline aqueous solution used for the alkali etching treatment include an aqueous solution containing one or more of caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide and the like. . In particular, an aqueous solution mainly composed of sodium hydroxide (caustic soda) is preferable. The alkaline aqueous solution may contain 0.5 to 10% by mass of alloy components contained in the aluminum plate as well as aluminum.
The concentration of the alkaline aqueous solution is preferably 1 to 50% by mass, and more preferably 1 to 30% by mass.
[0059]
The alkaline etching treatment is preferably carried out by treating the alkaline aqueous solution at a temperature of 20 to 100 ° C., preferably 40 to 80 ° C., and treating for 1 to 120 seconds, preferably 2 to 60 seconds. The amount of aluminum dissolved is 5 to 20 g / m when it is carried out after the mechanical surface roughening treatment. ² It is preferably 0.01 to 20 g / m when performed after the electrochemical surface roughening treatment. ² Is preferred. When mixing a chemical etching solution in an alkaline aqueous solution first, it is preferable to prepare a treatment solution using liquid sodium hydroxide (caustic soda) and sodium aluminate (sodium aluminate).
In addition, after the alkali etching process is completed, it is preferable to perform liquid drainage with a nip roller and water washing with a spray so that the processing liquid is not taken out to the next process.
[0060]
When the alkali etching treatment is performed after the electrochemical surface roughening treatment, smut generated by the electrochemical surface roughening treatment can be removed. As such an alkali etching treatment, for example, a method of contacting with 15 to 65 mass% sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739 and JP-B-48-28123. A method for performing alkali etching described in Japanese Patent Publication No. JP-A-2000-133 is preferred.
[0061]
By this alkali etching, the wavelength (opening diameter) of the large wave and / or medium wave in the above superimposed structure can be controlled to a value within a preferable range to some extent.
[0062]
(Acid etching process)
The acidic etching treatment is a treatment for chemically etching the aluminum plate in an acidic aqueous solution, and is preferably performed after the electrochemical surface roughening treatment. Moreover, when performing the said alkali etching process before and / or after the said electrochemical roughening process, it is also preferable to perform an acidic etching process after an alkali etching process.
When the above-mentioned alkaline etching treatment is performed on the aluminum plate and then the above-mentioned acidic etching treatment is performed, the intermetallic compound containing silica or simple substance Si on the surface of the aluminum plate can be removed, and the anodic oxidation generated in the subsequent anodizing treatment Film defects can be eliminated. As a result, it is possible to prevent the trouble that the dot-like ink adheres to the non-image portion called “dirty stain” during printing.
[0063]
Examples of the acidic aqueous solution used for the acidic etching treatment include an aqueous solution containing phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixed acid of two or more of these. Of these, a sulfuric acid aqueous solution is preferable. The concentration of the acidic aqueous solution is preferably 50 to 500 g / L. The acidic aqueous solution may contain an alloy component contained in the aluminum plate as well as aluminum.
[0064]
The acidic etching treatment is preferably performed by treating the liquid temperature at 60 to 90 ° C., preferably 70 to 80 ° C., for 1 to 10 seconds. The dissolution amount of the aluminum plate at this time is 0.001 to 0.2 g / m. ² Is preferred. The acid concentration, for example, the sulfuric acid concentration and the aluminum ion concentration are preferably selected from a range that does not crystallize at room temperature. A preferable aluminum ion concentration is 0.1 to 50 g / L, and particularly preferably 5 to 15 g / L.
In addition, after the acidic etching process is completed, in order not to take out the processing liquid to the next process, it is preferable to perform liquid drainage by a nip roller and water washing by spraying.
[0065]
(Desmut treatment)
When performing the alkali etching treatment before and / or after the electrochemical surface roughening treatment, smut is generally generated on the surface of the aluminum plate by the alkali etching treatment, so that phosphoric acid, nitric acid, sulfuric acid, chromic acid, The so-called desmut treatment, in which the smut is dissolved in an acidic solution containing hydrochloric acid, hydrofluoric acid, borofluoric acid, or a mixed acid of two or more of these, is preferably performed after the alkali etching treatment. In addition, after an alkali etching process, it is enough to perform any one of an acidic etching process and a desmut process.
[0066]
The concentration of the acidic solution is preferably 1 to 500 g / L. 0.001 to 50 g / L of the alloy component contained in the aluminum plate as well as aluminum may be dissolved in the acidic solution.
The liquid temperature of the acidic solution is preferably 20 ° C to 95 ° C, more preferably 30 to 70 ° C. Moreover, it is preferable that processing time is 1-120 second, and it is more preferable that it is 2-60 second.
Further, as the desmut treatment liquid (acid solution), it is preferable to use the waste liquid of the acidic aqueous solution used in the electrochemical surface roughening treatment in terms of reducing the amount of waste liquid.
After the desmutting process is completed, it is preferable to perform liquid drainage by a nip roller and water washing by spraying so that the processing liquid is not taken out to the next process.
[0067]
As a combination of these surface treatments, preferred embodiments are shown below.
First, a mechanical surface roughening treatment and / or an alkali etching treatment is performed, and then a desmut treatment is performed. Next, an electrochemical surface roughening treatment is performed, and then any one of (1) acid etching treatment, (2) alkali etching treatment and subsequent desmut treatment, and (3) alkali etching treatment and subsequent acidic etching treatment is performed. Do.
[0068]
The aluminum support of the present invention is provided with a hydrophilic film having a specific thermal conductivity. Furthermore, a support body is formed through pore wide treatment (acid treatment or alkali treatment), sealing treatment, and hydrophilic surface treatment as necessary. Further, an undercoat layer may be provided after forming the support, if necessary.
[0069]
<Formation of hydrophilic film>
A hydrophilic film having a low thermal conductivity is provided on the aluminum plate that has been subjected to the roughening treatment and other treatments as necessary.
The hydrophilic film has a thermal conductivity in the film thickness direction of 0.05 W / (m · K) or more, preferably 0.08 W / (m · K) or more, and 0.5 W / (m · K). K) or less, preferably 0.3 W / (m · K) or less, more preferably 0.2 W / (m · K) or less. When the thermal conductivity in the film thickness direction is 0.05 to 0.5 W / (m · K), it is possible to suppress the diffusion of heat generated in the recording layer due to laser light exposure to the support. As a result, when the lithographic printing plate precursor according to the present invention is used as a conventional thermal positive type, there is no problem such as high sensitivity, no generation of residual film, and insufficient image formation.
[0070]
Hereinafter, the thermal conductivity in the film thickness direction of the hydrophilic film defined in the present invention will be described. Various methods have been reported so far for measuring the thermal conductivity of thin films. In 1986, ONO et al. Reported the thermal conductivity in the planar direction of the thin film using a thermograph. Attempts have also been made to apply an AC heating method to the measurement of thermophysical properties of thin films. The origin of the AC heating method can be traced back to the report of 1863, but in recent years, various measurement methods have been proposed by combining a heating method using a laser and a Fourier transform. Devices using the laser angstrom method are actually commercially available. All of these methods determine the thermal conductivity in the plane direction (in-plane direction) of the thin film.
[0071]
However, when considering the thermal conduction of thin films, thermal diffusion in the depth direction is rather an important factor. As reported variously, it is said that the thermal conductivity of the thin film is not isotropic, and it is extremely important to directly measure the thermal conductivity in the film thickness direction particularly in the case of the present invention. From this point of view, a method using a thermocomparator as an attempt to measure the thermophysical properties in the film thickness direction of a thin film is described in a paper by Lambropoulos et al. (APPLIED OPTICS, Vol. 32, No. 1 (1 January 1993)). Furthermore, in recent years, a method for measuring the thermal diffusivity of a polymer thin film by temperature wave thermal analysis using Fourier analysis has been reported by Hashimoto et al. (Netsuke, 27 (3) (2000)).
[0072]
The thermal conductivity in the film thickness direction of the hydrophilic film defined in the present invention is measured by the method using the thermo-comparator. Hereinafter, the above method will be described in detail. The basic principle of the above method is described in detail in the above-mentioned Lambropoulos et al. Paper and Henger et al. Paper. Moreover, the apparatus used for the said method is not limited to the following apparatuses.
[0073]
FIG. 3 is a schematic view of a thermocomparator 30 that can be used for measuring the thermal conductivity in the film thickness direction of the hydrophilic film of the lithographic printing plate precursor according to the invention. In FIG. 3, 30 is a thermo comparator, 31 is a chip, 32 is a reservoir, 33 is an electric heater, 34 is a heating jacket, 35 is a thermocouple, 36 is a heat sink, 37 is a film, 38 is a metal substrate, 39 is a contact type A thermometer, 40 is a tip temperature recorder, 41 is a heat sink temperature recorder, and 42 is a reservoir temperature recorder.
The method using the thermocomparator is greatly affected by the contact area with the thin film and the state (roughness) of the contact surface. Therefore, it is important to make the tip where the thermocomparator 30 contacts the thin film as small as possible. For example, oxygen-free copper radius r ₁ = 0. A chip (wire) 31 having a minute tip of 2 mm is used. The chip 31 is fixed to the center of a constantan reservoir 32, and an oxygen-free copper heating jacket 34 having an electric heater 33 is fixed around the reservoir 32. When the heating jacket 34 is heated by the electric heater 33 and the reservoir 32 is controlled to 60 ± 1 ° C. while feeding back the output of the thermocouple 35 attached inside the reservoir 32, the chip 31 is heated to 60 ± 1 ° C. Is done. On the other hand, an oxygen-free copper heat sink 36 having a radius of 10 cm and a thickness of 10 mm is prepared, and a metal substrate 38 having a film 37 to be measured is placed on the heat sink 36. The surface temperature of the heat sink 36 is measured using a contact thermometer 39.
[0074]
After setting the thermocomparator 30 in this way, the tip of the heated chip 31 is brought into close contact with the surface of the film 37. The thermocomparator 30 is attached to the tip of the dynamic microhardness meter in place of the indenter and is driven up and down. Press until a load of 5 mN is applied. Thereby, the variation in the contact area of the film 37 to be measured and the chip 31 can be minimized.
When the heated tip 31 is brought into contact with the film 37, the tip temperature of the tip 31 decreases, but reaches a steady state at a certain constant temperature. This is because the amount of heat given from the electric heater 33 to the chip 31 through the heating jacket 34 and the reservoir 32 is balanced with the amount of heat diffused from the chip 31 to the heat sink 36 through the metal substrate 38. The tip temperature, the heat sink temperature, and the reservoir temperature at this time are recorded using the tip temperature recorder 40, the heat sink temperature recorder 41, and the reservoir temperature recorder 42, respectively.
[0075]
The relationship between each temperature and the thermal conductivity of the film is expressed by the following formula [1].
[0076]
[Expression 1]

[0077]
However, the code | symbol in said Formula [1] is as follows.
T _t : Tip tip temperature, T _b : Heat sink temperature, T _r : Reservoir temperature,
K _tf : Thermal conductivity of film, K ₁ : Reservoir thermal conductivity,
K ₂ : Chip thermal conductivity (in the case of oxygen-free copper, 400 W / (m · K)),
K ₄ : Metal substrate thermal conductivity (when no coating is provided),
r ₁ : Tip radius of curvature,
A ₂ : Contact area between reservoir and tip, A ₃ : Contact area between tip and film,
t: film thickness, t ₂ : Contact thickness (≒ 0)
[0078]
Each temperature (T _t , T _b And T _r ) Is measured and plotted to determine the slope of the above equation [1], and the film thermal conductivity (K _tf ). That is, as is apparent from the above equation [1], this slope is the reservoir thermal conductivity (K ₁ ), Radius of curvature of tip of tip (r ₁ ), Film thermal conductivity (K _tf ) And the contact area between the tip and the coating (A ₃ ) And is determined by K ₁ , R ₁ And A ₃ Is a known value, so K _tf Can be obtained.
[0079]
The present inventors have used an anodic oxide film (Al ₂ O ₃ ) Was determined. Measure the temperature by changing the film thickness, and find the Al obtained from the slope of the resulting graph. ₂ O ₃ The thermal conductivity of It was 69 W / (m · K). This is in good agreement with the results of Lambropoulos et al. And this result shows that the thermophysical value of the thin film is the bulk thermophysical value (bulk Al ₂ O ₃ It is also shown that the thermal conductivity of is different from 28 W / (m · K)).
[0080]
When the above method is used to measure the thermal conductivity in the film thickness direction of the hydrophilic film of the lithographic printing plate precursor according to the present invention, the tip end is made minute and the lithographic printing plate is kept constant by keeping the pressing load constant. For the surface roughened for the purpose, it is preferable because a result without variation can be obtained. The value of thermal conductivity is preferably measured at a plurality of different points on the sample, for example, 5 points, and obtained as an average value.
[0081]
The film thickness of the hydrophilic film is preferably 0.1 μm or more, more preferably 0.3 μm or more, particularly 0.6 μm or more in terms of scratch resistance and printing durability. Preferably, from the viewpoint of manufacturing cost, in view of the fact that a great amount of energy is required to provide a thick film, it is preferably 5 μm or less, more preferably 3 μm or less, and 2 μm or less. Is particularly preferred.
[0082]
The method for providing the hydrophilic film is not particularly limited, and an anodic oxidation method, a vapor deposition method, a CVD method, a sol-gel method, a sputtering method, an ion plating method, a diffusion method, and the like can be appropriately used. Moreover, the method of apply | coating the solution which mixed the hollow particle in hydrophilic resin or sol-gel liquid can also be used.
[0083]
Among them, it is most preferable to use an anodizing process, that is, an anodizing process. The anodizing treatment can be performed by a method conventionally used in this field. Specifically, when direct current or alternating current is applied to an aluminum plate in an aqueous solution or non-aqueous solution of sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc., alone or in combination of two or more. An anodized film that is a hydrophilic film can be formed on the surface of the aluminum plate.
The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be determined unconditionally. In general, however, the electrolyte concentration is 1 to 80% by mass, the solution temperature is 5 to 70 ° C., and the current density is 0.5. ~ 60A / dm ² It is appropriate that the voltage is 1 to 200 V and the electrolysis time is 1 to 1000 seconds.
Among these anodizing treatments, a method for anodizing at a high current density in a sulfuric acid electrolyte solution described in British Patent 1,412,768, and US Pat. No. 3,511,661. A method of anodizing treatment using phosphoric acid as an electrolytic bath is preferable. Further, multi-stage anodizing treatment such as anodizing treatment in sulfuric acid and further anodizing treatment in phosphoric acid can be performed.
[0084]
In the present invention, the anodic oxide film is 0.1 g / m in terms of scratch resistance and printing durability. ² Preferably, it is 0.3 g / m ² More preferably, it is 2 g / m. ² In view of the fact that a large amount of energy is required to provide a thick film, it is particularly preferable that the above is 100 g / m. ² Preferably, it is 10 g / m or less. ² More preferably, it is 6 g / m ² It is particularly preferred that
[0085]
On the surface of the anodized film, fine recesses called micropores are uniformly distributed. The density of the micropores present in the anodized film can be adjusted by appropriately selecting the treatment conditions. By increasing the density of the micropores, the thermal conductivity in the film thickness direction of the anodized film can be set to 0.05 to 0.5 W / (m · K).
[0086]
In the present invention, for the purpose of lowering the thermal conductivity, it is preferable to perform a pore wide treatment for expanding the pore diameter of the micropore after the anodizing treatment. In this pore wide treatment, an aluminum substrate on which an anodized film is formed is immersed in an acid aqueous solution or an alkali aqueous solution to dissolve the anodized film and enlarge the pore diameter of the micropore. In the pore wide treatment, the dissolution amount of the anodized film is preferably 0.01 to 20 g / m. ² , More preferably 0.1 to 5 g / m ² , Particularly preferably 0.2 to 4 g / m ² It is performed in the range.
[0087]
When an aqueous acid solution is used for the pore wide treatment, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, or a mixture thereof. The concentration of the acid aqueous solution is preferably 10 to 1000 g / L, and more preferably 20 to 500 g / L. The temperature of the acid aqueous solution is preferably 10 to 90 ° C, and more preferably 30 to 70 ° C. The immersion time in the acid aqueous solution is preferably 1 to 300 seconds, and more preferably 2 to 100 seconds.
On the other hand, when an alkaline aqueous solution is used for pore wide treatment, it is preferable to use an aqueous solution of at least one alkali selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. The pH of the alkaline aqueous solution is preferably 10 to 13, and more preferably 11.5 to 13.0. The temperature of the aqueous alkali solution is preferably 10 to 90 ° C, and more preferably 30 to 50 ° C. The immersion time in the alkaline aqueous solution is preferably 1 to 500 seconds, and more preferably 2 to 100 seconds.
[0088]
Further, the hydrophilic film may be an inorganic film provided by a sputtering method, a CVD method or the like in addition to the above-described anodized film. Examples of the compound constituting the inorganic film include oxides, nitrides, silicides, borides, and carbides. Moreover, the inorganic film may be comprised only from the compound single-piece | unit, and may be comprised by the mixture of the compound.
Specific examples of the compound constituting the inorganic film include aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, hafnium oxide, vanadium oxide, niobium oxide, tantalum oxide, molybdenum oxide, tungsten oxide, chromium oxide; aluminum nitride , Silicon nitride, titanium nitride, zirconium nitride, hafnium nitride, vanadium nitride, niobium nitride, tantalum nitride, molybdenum nitride, tungsten nitride, chromium nitride, silicon nitride, boron nitride; Titanium silicide, zirconium silicide, hafnium silicide, vanadium silicide, niobium silicide, tantalum silicide, molybdenum silicide, tungsten silicide, chromium silicide; titanium boride, zirconium boride, hafnium boride, vanadium boride , Niobium boride, boride Tantalum, molybdenum boride, tungsten boride, chromium boride; aluminum carbide, silicon carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide, molybdenum carbide, tungsten carbide, and a chromium carbide.
[0089]
In the present invention, the hydrophilic film has a density of 1.0 to 3.2 g / cm. ³ Or it is one of the preferable aspects that the porosity is 20 to 70%.
[0090]
A low-density film is formed under the above conditions. The density of the formed film is measured by, for example, weight measurement by the Mason method (anodic oxide film weight method by dissolution of chromic acid / phosphoric acid mixed solution) and the cross section is observed by SEM. The film thickness can be calculated by the following formula.
Density (g / cm ³ ) = (Film weight per unit area / film thickness)
The density of the film formed here is 1.0 g / cm ³ If it is less than 1, the film strength will be low, and there is a possibility of adversely affecting the image forming property, printing durability, etc. 3.2 g / cm ³ If it exceeds 1, sufficient heat insulation cannot be obtained, and the effect of improving the sensitivity becomes low.
[0091]
In the present invention, the porosity of the anodized film is preferably 20 to 70%, more preferably 30 to 60%, and particularly preferably 40 to 50%. When the porosity of the anodized film is 20% or more, the thermal diffusion to the aluminum support is sufficiently suppressed, and the effect of increasing the sensitivity is sufficiently obtained. When the porosity of the anodic oxide film is 70% or less, a problem that stains occur in the non-image area is less likely to occur.
[0092]
The porosity of the anodized film can be measured by the following method.
Porosity (%) = {1− (oxide film density / 3.98)} × 100
Here, 3.98 is the density of aluminum oxide by chemical handbook (g / cm ³ ).
[0093]
Density is 1.0-3.2 g / cm ³ If the film is formed, the problem of printing stains such as ink deteriorating deterioration can be solved in exchange for high sensitivity.
[0094]
<Sealing treatment>
In the present invention, the aluminum support obtained by providing the hydrophilic film as described above may be sealed.
For example, when the electrodeposition sealing process is performed, the sealing treatment film is formed from the bottom of the pore. When the water vapor sealing process is performed, the sealing treatment film is formed from the top of the pore. The formation of the pore-treated film is different.
The formation of the sealing process suitable for the present invention is a sealing process in which only the surface micropores are sealed without sealing the inside of the hydrophilic film.
As the sealing treatment used in the present invention, an anodized film of pressurized steam or hot water described in JP-A-4-176690 and Japanese Patent Application No. 10-106819 (JP-A-11-301135) is used. A sealing process is mentioned. In addition, silicate treatment, dichromate aqueous solution treatment, nitrite treatment, ammonium acetate treatment, electrodeposition sealing treatment, triethanolamine treatment, barium carbonate treatment, hydrothermal treatment containing a trace amount of phosphate It can also carry out using well-known methods, such as. Among them, the sealing treatment suitable for the present invention is sealing treatment with fine particles described in Japanese Patent Application No. 2001-9871.
In the sealing treatment with fine particles, a particle layer comprising particles having an average particle size of 8 to 800 nm, preferably an average particle size of 10 to 500 nm, more preferably an average particle size of 10 to 150 nm is provided. When the average particle diameter of the particles is 8 nm or more, there is little possibility that the particles enter the micropores existing in the anodized film, and the effect of increasing sensitivity can be sufficiently obtained. When the average particle size of the particles is 800 nm or less, the adhesion to the heat-sensitive layer is sufficient, and the printing durability is excellent. The thickness of the particle layer is preferably 8 to 800 nm, and more preferably 10 to 500 nm.
[0095]
The particles used in the present invention preferably have a thermal conductivity of 60 W / (m · K) or less, more preferably 40 W / (m · K) or less, and 0.3 to 10 W / (m · K). K) It is particularly preferred that When the thermal conductivity is 60 W / (m · K) or less, the thermal diffusion to the aluminum support is sufficiently suppressed, and the effect of increasing the sensitivity is sufficiently obtained.
[0096]
The method for providing the particle layer is not particularly limited, but a method in which the aluminum support is subjected to electrolytic treatment using direct current or alternating current using an electrolytic solution containing hydrophilic particles having an average particle diameter of 8 to 800 nm is preferable. Examples of the alternating current waveform used in the electrolytic treatment include a sine wave, a rectangular wave, a triangular wave, and a trapezoidal wave. In addition, the frequency of the alternating current is preferably 30 to 200 Hz, more preferably 40 to 120 Hz, from the viewpoint of the cost of manufacturing the power supply device. When a trapezoidal wave is used as the waveform of the alternating current, the time tp until the current reaches a peak from 0 is preferably 0.1 to 2 msec, and more preferably 0.3 to 1.5 msec. If the tp is less than 0.1 msec, the impedance of the power supply circuit is affected, and a large power supply voltage is required at the time of rising of the current waveform, which may increase the equipment cost of the power supply.
As hydrophilic particles, Al ₂ O ₃ TiO ₂ , SiO ₂ And ZrO ₂ Are preferably used alone or in combination of two or more. The electrolytic solution is obtained, for example, by suspending the hydrophilic particles in water or the like so that the content becomes 0.01 to 20% by mass of the whole. The electrolytic solution can be adjusted in pH by, for example, adding sulfuric acid in order to charge the charge positively or negatively. The electrolytic treatment is performed, for example, using direct current, using an aluminum support as a cathode, and using the above electrolytic solution at a voltage of 10 to 200 V for 1 to 600 seconds.
According to this method, it is possible to easily close the mouth while leaving a void inside the micropore existing in the anodized film.
Other sealing methods include immersion in solution, spraying, coating, vapor deposition, sputtering, ion plating, thermal spraying, plating, and the like, but are not particularly limited.
[0097]
The specific treatment method is, for example, selected from the group consisting of at least one amino group, a carboxyl group and a salt group thereof, and a sulfo group and a salt group described in JP-A-60-149491. A layer composed of a compound having at least one group, a compound having at least one amino group and at least one hydroxy group, and a salt thereof described in JP-A-60-232998 A layer comprising the above compound, a layer containing a phosphate described in JP-A-62-19494, and at least one monomer unit having a sulfo group described in JP-A-59-101651 And a method of providing a layer composed of a polymer compound having as a repeating unit in the molecule by coating.
[0098]
In addition, carboxymethyl cellulose; dextrin; gum arabic; phosphonic acids having an amino group such as 2-aminoethylphosphonic acid; phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, which may have a substituent, Organic phosphonic acid such as methylene diphosphonic acid and ethylene diphosphonic acid; organic phosphoric acid ester such as phenyl phosphoric acid, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphoric acid which may have a substituent; Organic phosphinic acids such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid; amino acids such as glycine and β-alanine; hydrochlorides of amines having a hydroxy group such as hydrochloride of triethanolamine Providing a layer of a compound selected from The law may also be mentioned.
[0099]
In the sealing treatment, a silane coupling agent having an unsaturated group may be applied. Examples of the silane coupling agent include N-3- (acryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, (3-acryloxypropyl) dimethylmethoxysilane, and (3-acryloxypropyl) methyldimethoxy. Silane, (3-acryloxypropyl) trimethoxysilane, 3- (N-allylamino) propyltrimethoxysilane, allyldimethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, 3-butenyltriethoxysilane, 2- ( Chloromethyl) allyltrimethoxysilane, methacrylamidopropyltriethoxysilane, N- (3-methacryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, (methacryloxymethyl) dimethylethoxysilane, Tacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxypropyldimethylethoxysilane, methacryloxypropyldimethylmethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, methacryloxypropylmethyltriethoxysilane , Methacryloxypropylmethyltrimethoxysilane, methacryloxypropyltris (methoxyethoxy) silane, methoxydimethylvinylsilane, 1-methoxy-3- (trimethylsiloxy) butadiene, styrylethyltrimethoxysilane, 3- (N-styrylmethyl-2) -Aminoethylamino) -propyltrimethoxysilane hydrochloride, vinyldimethylethoxysilane, vinyldiphenyl ester Xysilane, vinylmethyldiethoxysilane, vinylmethyldimethoxysilane, O- (vinyloxyethyl) -N- (triethoxysilylpropyl) urethane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltri-t-butoxysilane, vinyltriisopropoxy Examples include silane, vinyltriphenoxysilane, vinyltris (2-methoxyethoxy) silane, and diallylaminopropylmethoxysilane. Among these, a silane coupling agent having a methacryloyl group or an acryloyl group having a fast reactivity of the unsaturated group is preferable.
[0100]
In addition to this, the sol-gel coating treatment described in JP-A-5-50779, the phosphonic acid coating treatment described in JP-A-5-246171, JP-A-6-234284, JP-A-6-6 No. 191733 and JP-A-6-230563, a method for treating a backcoat material by coating, treatment of phosphonic acids described in JP-A-6-262872, and JP-A-6-297875. JP-A-10-109480, Japanese Patent Application No. 10-252078 (Japanese Patent Application Laid-Open No. 2000-81704) and Japanese Patent Application No. Hei 10 -253411 (Japanese Patent Laid-Open No. 2000-89466) Cough treatment method and the like, may be used any method.
[0101]
<Hydrophilic surface treatment>
In the present invention, a hydrophilic surface treatment is performed by immersing the aluminum support of the present invention obtained by providing a hydrophilic film as described above in an aqueous solution further containing one or more hydrophilic compounds. You may go. Preferred examples of the hydrophilic compound include polyvinyl phosphonic acid, a compound having a sulfonic acid group, a saccharide compound, and a silicate compound.
[0102]
The compound having a sulfonic acid group includes an aromatic sulfonic acid, a formaldehyde condensate thereof, a derivative thereof, and a salt thereof.
Examples of the aromatic sulfonic acid include phenol sulfonic acid, catechol sulfonic acid, resorcinol sulfonic acid, benzene sulfonic acid, toluene sulfonic acid, lignin sulfonic acid, naphthalene sulfonic acid, acenaphthene-5-sulfonic acid, phenanthrene-2-sulfonic acid. Benzaldehyde-2 (or 3) -sulfonic acid, benzaldehyde-2,4 (or 3,5) -disulfonic acid, oxybenzylsulfonic acids, sulfobenzoic acid, sulfanilic acid, naphthionic acid, and taurine. Of these, benzenesulfonic acid, naphthalenesulfonic acid, and ligninsulfonic acid are preferable. Also preferred are formaldehyde condensates of benzene sulfonic acid, naphthalene sulfonic acid, and lignin sulfonic acid.
Furthermore, these may be used as sulfonates. For example, sodium salt, potassium salt, lithium salt, calcium salt, magnesium salt can be mentioned. Of these, sodium salts and potassium salts are preferred.
The pH of the aqueous solution containing the compound having a sulfonic acid group is preferably 4 to 6.5, and can be adjusted to the above pH range using sulfuric acid, sodium hydroxide, ammonia or the like.
[0103]
The saccharide compounds include monosaccharides and their sugar alcohols, oligosaccharides, polysaccharides, and glycosides.
Monosaccharides and sugar alcohols thereof include, for example, trioses such as glycerol and sugar alcohols thereof; tetroses such as treose and erythritol and sugar alcohols thereof; pentoses such as arabinose and arabitol and sugar alcohols thereof; glucose, sorbitol and the like Hexoses and sugar alcohols thereof; heptoses and sugar alcohols such as D-glycero-D-galactoheptose and D-glycero-D-galactoheptitol; octoses such as D-erythro-D-galactoctitol and Examples thereof include sugar alcohols; nonoses such as D-erythro-L-gluco-nonulose and sugar alcohols thereof.
Examples of oligosaccharides include disaccharides such as saccharose, trehalose, and lactose; and trisaccharides such as raffinose.
Examples of the polysaccharide include amylose, arabinan, cyclodextrin, and cellulose alginate.
[0104]
In the present invention, the “glycoside” refers to a compound in which a sugar moiety and a non-sugar moiety are bonded through an ether bond or the like.
Glycosides can be classified by non-sugar moieties. For example, alkyl glycoside, phenol glycoside, coumarin glycoside, oxycoumarin glycoside, flavonoid glycoside, anthraquinone glycoside, triterpene glycoside, steroid glycoside, mustard oil glycoside Can be mentioned.
Examples of the sugar moiety include the above-described monosaccharides and sugar alcohols thereof; oligosaccharides; polysaccharides. Among these, monosaccharides and oligosaccharides are preferable, and monosaccharides and disaccharides are more preferable.
Examples of preferred glycosides include compounds represented by the following formula (1).
[0105]
[Chemical 1]

[0106]
In said formula (1), R represents the alkyl group, the alkenyl group, or the alkynyl group which has a C1-C20 linear or branched.
Examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, Examples include tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and eicosyl group. These may be straight chain, branched, or cyclic alkyl. It may be a group.
Examples of the alkenyl group having 1 to 20 carbon atoms include an allyl group and a 2-butenyl group, which may be linear or branched, and may be a cyclic alkenyl group. There may be.
Examples of the alkynyl group having 1 to 20 carbon atoms include a 1-pentynyl group, which may be linear or branched, and may be a cyclic alkynyl group. Good.
[0107]
Specific examples of the compound represented by the above formula (1) include, for example, methyl glucoside, ethyl glucoside, propyl glucoside, isopropyl glucoside, butyl glucoside, isobutyl glucoside, n-hexyl glucoside, octyl glucoside, capryl glucoside, decyl glucoside, Examples include 2-ethylhexyl glucoside, 2-pentylnonyl glucoside, 2-hexyl decyl glucoside, lauryl glucoside, myristyl glucoside, stearyl glucoside, cyclohexyl glucoside, and 2-butynyl glucoside. These compounds are glucosides, which are a type of glycoside, in which the hemiacetal hydroxyl group of glucose is linked to other compounds in an ether form, and are obtained, for example, by a known method of reacting glucose with alcohols. be able to. Some of these alkyl glucosides are marketed under the trade name GLUCOPON by Henkel, Germany, and can be used in the present invention.
[0108]
Other examples of preferred glycosides include saponins, rutin trihydrate, hesperidin methyl chalcone, hesperidin, nalidine hydrate, phenol-β-D-glucopyranoside, salicin, 3 ′, 5,7-methoxy-7. -Rutinosides are mentioned.
[0109]
The pH of the aqueous solution containing the saccharide compound is preferably 8 to 11, and can be adjusted to the above pH range using potassium hydroxide, sulfuric acid, carbonic acid, sodium carbonate, phosphoric acid, sodium phosphate or the like.
[0110]
The concentration of the aqueous solution of polyvinylphosphonic acid is preferably 0.1 to 5% by mass, and more preferably 0.2 to 2.5%. The immersion temperature is preferably 10 to 70 ° C, and more preferably 30 to 60 ° C. The immersion time is preferably 1 to 20 seconds.
Moreover, it is preferable that the density | concentration of the aqueous solution of the compound which has a sulfonic acid group is 0.02-0.2 mass%. The immersion temperature is preferably 60 to 100 ° C. The immersion time is preferably 1 to 300 seconds, and more preferably 10 to 100 seconds.
Further, the aqueous solution of the saccharide compound preferably has a concentration of 0.5 to 10% by mass. The immersion temperature is preferably 40 to 70 ° C. The immersion time is preferably 2 to 300 seconds, and more preferably 5 to 30 seconds.
[0111]
In the present invention, as the aqueous solution containing a hydrophilic compound, in addition to the organic compound aqueous solution as described above, an alkali metal silicate aqueous solution, potassium zirconium fluoride (K ₂ ZrF ₆ An aqueous solution of an inorganic compound such as an aqueous solution or an aqueous solution containing a phosphate / inorganic fluorine compound is also preferably used.
[0112]
The alkali metal silicate treatment is preferably an alkali metal silicate having a concentration of 0.01 to 30% by mass, more preferably 0.1 to 10% by mass, and a pH at 25 ° C. of preferably 10 to 13. It is carried out by immersing the support in an aqueous acid salt solution at 10 to 100 ° C., more preferably 20 to 80 ° C., preferably 0.5 to 40 seconds, more preferably 1 to 20 seconds.
[0113]
Examples of the alkali metal silicate used in the present invention include sodium silicate, potassium silicate, and lithium silicate. Of these, sodium silicate and potassium silicate are preferable.
The aqueous solution of alkali metal silicate may contain an appropriate amount of a hydroxide such as sodium hydroxide, potassium hydroxide, or lithium hydroxide in order to increase the pH. Of these, sodium hydroxide and potassium hydroxide are preferable.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVB) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Is mentioned. Examples of Group 4 (Group IVB) metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium oxalate potassium, titanium sulfate, titanium tetraiodide, zirconium chloride oxide, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVB) metal salts are used alone or in combination of two or more.
[0114]
The amount of Si adsorbed by the alkali metal silicate treatment is measured by a fluorescent X-ray analyzer, and the amount of adsorption is about 0.1 to 15.0 mg / m. ² Is preferred.
By this alkali metal silicate treatment, an effect of improving the solubility resistance of the aluminum support surface to the alkaline developer is obtained, and the dissolution of the aluminum component into the developer is suppressed. Can be reduced.
[0115]
Zirconium potassium fluoride aqueous solution treatment is preferably carried out at an aqueous solution of potassium zirconium fluoride having a concentration of 0.1 to 10% by mass, more preferably 0.5 to 2% by mass, preferably at 30 to 80 ° C. It is preferably performed by dipping for 60 to 180 seconds.
[0116]
The phosphate / inorganic fluorine compound treatment is preferably an aqueous solution having a phosphate compound concentration of 5 to 20% by mass and an inorganic fluorine compound concentration of 0.01 to 1% by mass, preferably a pH of 3 to 5. The support is preferably immersed in at 20 to 100 ° C., more preferably at 40 to 80 ° C., preferably for 2 to 300 seconds, more preferably for 5 to 30 seconds.
[0117]
Examples of the phosphate used in the present invention include phosphates of metals such as alkali metals and alkaline earth metals.
Specifically, for example, zinc phosphate, aluminum phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, monoammonium phosphate, monopotassium phosphate, monosodium phosphate, dihydrogen phosphate Potassium, dipotassium hydrogen phosphate, calcium phosphate, sodium ammonium hydrogen phosphate, magnesium hydrogen phosphate, magnesium phosphate, ferrous phosphate, ferric phosphate, sodium dihydrogen phosphate, sodium phosphate, hydrogen phosphate Disodium, lead phosphate, diammonium phosphate, calcium dihydrogen phosphate, lithium phosphate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, ammonium phosphomolybdate, sodium phosphomolybdate; sodium phosphite , Tripolyphosphate Potassium, and sodium pyrophosphate. Among these, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate are preferable.
[0118]
Moreover, a metal fluoride is mentioned suitably as an inorganic fluorine compound used for this invention.
Specifically, for example, sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, sodium hexafluorozirconium, hexafluorozirconium potassium, sodium hexafluorotitanate, potassium hexafluorotitanate, hexafluorozirconium hydrogen acid , Hexafluorotitanium hydrogen acid, hexafluorozirconium ammonium, ammonium hexafluorotitanate, hexafluorosilicic acid, nickel fluoride, iron fluoride, phosphorous phosphate, ammonium fluoride phosphate.
[0119]
The aqueous solution used for the phosphate / inorganic fluorine compound treatment may contain one or more phosphates and inorganic fluorine compounds, respectively.
[0120]
After immersing the support in an aqueous solution containing these hydrophilic compounds, the support is washed with water or the like and dried.
[0121]
By the above-described sealing treatment and hydrophilic surface treatment, problems of printing stains such as deterioration of ink repellency that occurs in exchange for sensitivity improved by the pore wide treatment after the anodizing treatment are solved. That is, the phenomenon that the ink becomes difficult to remove when printing is started, especially when the printing machine is stopped and printing is restarted after the lithographic printing plate is left on the printing machine due to the enlarged pore diameter (degradation of ink repellency). However, if a sealing treatment or a hydrophilic surface treatment is performed, the above problem is reduced.
[0122]
<Undercoat layer>
In the present invention, before providing a heat-sensitive layer on the aluminum support of the present invention thus obtained, an inorganic primer such as a water-soluble metal salt such as zinc borate is optionally provided. A layer or an organic undercoat layer may be provided.
[0123]
Examples of the organic compound used in the organic undercoat layer include carboxymethyl cellulose; dextrin; gum arabic; polymers and copolymers having a sulfonic acid group in the side chain; polyacrylic acid; amino such as 2-aminoethylphosphonic acid Phosphonic acids having a group; organic phosphonic acids such as phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid, and ethylenediphosphonic acid, which may have a substituent; Organic phosphoric acid such as phenylphosphonic acid, naphthylphosphoric acid, alkylphosphoric acid, glycerophosphoric acid, which may be substituted; phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid, glycerophosphinic acid, etc., which may have a substituent Organic phosphinic acids; amino acids such as glycine and β-alanine Amine hydrochloride having a hydroxyl group such as triethanolamine hydrochloride; and the yellow dye. These may be used alone or in combination of two or more.
[0124]
The organic undercoat layer is provided by applying a solution obtained by dissolving the above organic compound in water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof on an aluminum plate and drying it. The concentration of the solution in which the organic compound is dissolved is preferably 0.005 to 10% by mass. The coating method is not particularly limited, and any method such as bar coater coating, spin coating, spray coating, curtain coating and the like can be used.
The coating amount of the organic undercoat layer after drying is 2 to 200 mg / m ² Is preferably 5 to 100 mg / m ² It is more preferable that When it is in the above range, the printing durability becomes better.
[0125]
<Back coat layer>
The support obtained as described above has an organic polymer on the back surface (the surface on which the heat-sensitive layer is not provided) so that the heat-sensitive layer will not be damaged even if it is laminated when the planographic printing plate precursor is used. A coating layer made of a compound (hereinafter also referred to as “backcoat layer”) may be provided as necessary.
As a main component of the back coat layer, at least one resin selected from the group consisting of a saturated copolymerized polyester resin, a phenoxy resin, a polyvinyl acetal resin, and a vinylidene chloride copolymer resin having a glass transition point of 20 ° C. or higher is used. Is preferred.
[0126]
The saturated copolyester resin is composed of a dicarboxylic acid unit and a diol unit. Examples of the dicarboxylic acid unit include aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, tetrabromophthalic acid, and tetrachlorophthalic acid; adipic acid, azelaic acid, succinic acid, oxalic acid, suberic acid, and sebacic acid , Saturated aliphatic dicarboxylic acids such as malonic acid and 1,4-cyclohexanedicarboxylic acid.
[0127]
The backcoat layer further comprises a dye or pigment for coloring, a silane coupling agent for improving the adhesion to the support, a diazo resin comprising a diazonium salt, an organic phosphonic acid, an organic phosphoric acid, a cationic polymer, Wax, higher fatty acids, higher fatty acid amides, silicone compounds composed of dimethylsiloxane, modified dimethylsiloxane, polyethylene powder and the like that are usually used as slipping agents can be appropriately contained.
[0128]
The thickness of the backcoat layer may be basically a level that does not easily damage a heat-sensitive layer to be described later even if no interleaf is present, and is preferably 0.01 to 8 μm. When the thickness is less than 0.01 μm, it is difficult to prevent the heat-sensitive layer from being scratched when the planographic printing plate precursors are handled in layers. On the other hand, when the thickness exceeds 8 μm, the backcoat layer swells due to chemicals used around the lithographic printing plate during printing, the thickness varies, and the printing pressure may change to deteriorate the printing characteristics.
[0129]
Various methods can be used as a method of providing the back coat layer on the back surface of the support. For example, a method in which the above components for the back coat layer are dissolved in an appropriate solvent and applied as a solution, or an emulsified dispersion is applied and dried; a previously formed film is supported with an adhesive or heat. A method of bonding to a body; a method of forming a molten film with a melt extruder and bonding to a support. The most preferable method for securing a suitable thickness is a method in which the components for the backcoat layer are dissolved in a suitable solvent, applied as a solution, and dried. In this method, an organic solvent as described in JP-A-62-251739 can be used alone or in combination as a solvent.
[0130]
In the production of a lithographic printing plate precursor, either the back coat layer on the back surface or the heat sensitive layer on the front surface may be provided on the support first, or both may be provided simultaneously.
[0131]
[Lithographic printing plate precursor]
The lithographic printing plate precursor according to the present invention is provided with a heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared-absorbing dye on the aluminum support obtained as described above, and increasing the solubility in an alkaline aqueous solution by heating. It becomes.
[0132]
<Image forming layer>
The image forming layer (recording layer, heat-sensitive layer) used in the lithographic printing plate precursor according to the present invention is a heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared-absorbing dye and having increased solubility in an alkaline aqueous solution by heating. A heat-sensitive layer consisting of two or more layers is preferred. Since an alkali-soluble layer and a surface hardly-solubilized layer can be provided separately, a larger descrimation can be obtained. As the heat-sensitive layer comprising two or more layers, for example, a heat-sensitive layer having a multilayer structure separately from a heat-sensitive layer in which an alkali-soluble intermediate layer and a photosensitive layer that is alkali-solubilized by heating are sequentially provided and the intermediate layer are provided. Is preferred. Hereinafter, the intermediate layer easily soluble in alkali and the heat-sensitive layer that is alkali-solubilized by heating will be described. The planographic printing plate precursor of the present invention has a two-layer structure such as “intermediate layer” and “heat-sensitive layer” described below, and in one heat-sensitive layer, the alkali support on the side opposite to the aluminum support. The thing of the structure whose solubility is higher than the solubility in the surface side is contained.
[0133]
The heat-sensitive layer contains an alkali-soluble resin (also referred to as an alkali-soluble polymer compound) and an infrared absorbing dye (also referred to as a photothermal conversion substance).
Alkali-soluble polymer compounds include homopolymers containing acidic groups in the polymer, copolymers thereof, and mixtures thereof, in particular, (1) phenolic hydroxy groups (—Ar—OH), (2) Sulfonamide group (—SO ₂ Those having an acidic group such as NH-R) are preferred from the viewpoint of solubility in an alkali developer. In particular, it is preferable to have a phenolic hydroxy group from the viewpoint of excellent image formability upon exposure with an infrared laser or the like. For example, phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) may be mixed Preferred are novolak resins such as formaldehyde resin; pyrogallol acetone resin. More specifically, the polymers described in JP-A-2001-305722, [0023] to [0042] are preferably used.
[0134]
The photothermal conversion substance converts exposure energy into heat and can efficiently cancel the interaction of the exposed area of the heat sensitive layer. From the viewpoint of recording sensitivity, a pigment or dye having a light absorption region in the infrared region with a wavelength of 700 to 1200 nm is preferable. Specific examples of the dye include 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 thiolates. Complex (for example, nickel thiolate complex) etc. are mentioned. Among these, cyanine dyes are preferable, and examples thereof include cyanine dyes represented by general formula (I) in JP-A No. 2001-305722.
[0135]
Examples of the intermediate layer used for the heat-sensitive layer include an intermediate layer containing a polymer compound having a component having an acid group and a component having an onium group, as described in JP-A No. 2000-105462. It is done.
[0136]
Examples of the composition used for the heat-sensitive layer include compounds such as sensitivity modifiers, printing agents and dyes described in [0024] to [0027] of JP-A-7-92660 and [0031] of the same publication. It is preferable to add a surfactant for improving the coating property as described in the above. Specifically, the compounds described in [0053] to [0059] of JP-A No. 2001-305722 are preferable.
The heat-sensitive layer may be a single layer or preferably has a two-layer structure as described in JP-A-11-218914.
It is preferable to provide an undercoat layer between the heat-sensitive layer and the support. Examples of components contained in the undercoat layer include various organic compounds described in JP-A-2001-305722, [0068].
[0137]
<Application method>
As a method for applying the image recording layer forming liquid to the roughened surface of the lithographic printing plate support, a conventionally known method such as a method using a coating rod, a method using an extrusion type coater, a method using a slide bead coater, etc. These methods can be used and can be carried out according to known conditions.
[0138]
As an apparatus for drying the aluminum plate after application of the image recording layer forming liquid, an arch type dryer described in JP-A-6-63487, in which a pass roll is disposed in the drying apparatus and dried while being conveyed by the pass roll, is disclosed. Air dryer that feeds air from above and below by nozzle and dries while floating the web, radiant heat dryer that dries by radiant heat from a medium heated to high temperature, and heat transfer by contact with the roller by heating the roller There is a roller dryer etc. which dries by.
[0139]
[Lithographic printing plate]
The lithographic printing plate precursor according to the invention is made into a lithographic printing plate by various processing methods according to the image recording layer.
In general, image exposure is performed. Examples of the actinic ray light source used for image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, and a chemical lamp. Examples of the laser beam include a helium-neon laser (He-Ne laser), an argon laser, a krypton laser, a helium-cadmium laser, a KrF excimer laser, a semiconductor laser, a YAG laser, and a YAG-SHG laser.
After the exposure, it is preferable to develop with a developer to obtain a lithographic printing plate. The preferred developer used for the lithographic printing plate precursor is not particularly limited as long as it is an alkaline developer, but an alkaline aqueous solution substantially not containing an organic solvent is preferred. Moreover, it can also develop using the developing solution which does not contain alkali metal silicate substantially. About the method of developing using the developing solution which does not contain alkali metal silicate substantially, it describes in Unexamined-Japanese-Patent No. 11-109637 in detail, The content described in this gazette can be used. . Moreover, the lithographic printing plate precursor can be developed using a developer containing an alkali metal silicate.
[0140]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
[0141]
<Examples 1 to 10 and Comparative Examples 1 to 7>
1. Manufacture of lithographic printing plate support (aluminum support)
<Aluminum plate>
Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.001 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: It contains 0.03% by mass, and the balance is prepared using Al and an inevitable impurity aluminum alloy. After the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm is obtained by a DC casting method. Created. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, it was kept soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing using a continuous annealing machine at 500 degreeC, it finished by cold rolling to 0.24 mm in thickness, and obtained the aluminum plate of JIS1050 material. This aluminum plate was adjusted to a width of 1030 mm.
[0142]
About the obtained aluminum plate, the roughening process method and hydrophilic film formation method which are shown below are sequentially performed by the combination shown in Table 1, and the aluminum support body of Examples 1-10 and Comparative Examples 1-7 is obtained. It was.
[0143]
[Table 1]

[0144]
<Roughening treatment method>
Roughening treatment method A
The following treatments (1) to (6) were continuously performed.
In addition, after each process and water washing, the liquid was drained with the nip roller.
[0145]
(1) Mechanical roughening treatment
Using a brush roller in which a nylon brush rotates while supplying a suspension of pumice having a specific gravity of 1.12 (abrasive, average particle size 50 μm) and water as a polishing slurry to the surface of the aluminum plate by a spray tube Mechanical roughening treatment was performed.
The material of the nylon brush used was 6,10-nylon, the hair length was 50 mm, and the hair diameter was 0.48 mm. This nylon brush is formed by making a hole in a stainless steel tube of φ300 mm so as to be dense.
Also, three nylon brushes were used for the brush roller, and the distance between the two support rollers (φ200 mm) provided at the lower part of the brush was 300 mm.
The brush roller manages the load of the drive motor that rotates the brush with respect to the load before the nylon brush is pressed against the aluminum plate, and the average arithmetic roughness (R) of the aluminum plate after roughening _a ) Is 0.45 μm (hereinafter referred to as “R _a " ). The rotating direction of the brush was the same as the moving direction of the aluminum plate. Then, it washed with water.
In addition, the concentration of the abrasive is referred to a table prepared in advance from the relationship between the abrasive concentration, temperature and specific gravity, the abrasive concentration is obtained from the temperature and specific gravity, water and abrasive are added by feedback control, The concentration of the abrasive was kept constant. Moreover, since the surface shape of the roughened aluminum plate changes when the abrasive is pulverized to reduce the particle size, the abrasive having a small particle size is sequentially discharged out of the system by the cyclone. The particle size of the abrasive was in the range of 1-100 μm.
[0146]
(2) Alkali etching treatment
An aqueous solution containing 70% by weight NaOH and 6.5% by weight aluminum ions at a liquid temperature of 70 ° C. was sprayed onto the aluminum plate with a spray tube to perform an alkali etching treatment. The amount of dissolution of the surface of the aluminum plate that is later subjected to electrochemical roughening is 8 g / m. ² The dissolution amount on the back surface is 2 g / m. ² Met.
The concentration of the etching solution used for the alkali etching treatment is determined in advance by referring to a table created from the relationship between the NaOH concentration, the aluminum ion concentration, the temperature, the specific gravity, and the conductivity of the solution. Then, the concentration of the etching solution was obtained and kept constant by adding water and a 48 mass% NaOH aqueous solution by feedback control. Then, it washed with water.
[0147]
(3) Desmut treatment
A nitric acid aqueous solution having a liquid temperature of 35 ° C. was sprayed onto the aluminum plate using a spray, and desmut treatment was performed for 10 seconds. As the nitric acid aqueous solution, the overflow waste liquid from the electrolyzer used in the next step was used. Next, several spray tubes for spraying the desmut treatment liquid were installed so that the surface of the aluminum plate was not dried until the next step.
[0148]
(4) Electrochemical roughening treatment
The electrochemical surface roughening treatment was continuously performed using the trapezoidal wave alternating current shown in FIG. 1 and the two electrolytic cell tanks shown in FIG. As the acidic aqueous solution, a nitric acid aqueous solution of 9.5 g / L of nitric acid (containing 5.0 g / L of aluminum ions and 0.07 g / L of ammonium ions) was used. The liquid temperature was 50 ° C. The alternating current had a time tp and tp ′ of 1 msec until the current value reached a peak from zero, and the carbon electrode was the counter electrode. The current density at the peak of the alternating current is 50 A / dm when the aluminum plate is an anode and a cathode. ² Met. Furthermore, the amount of electricity at the time of cathode of alternating current (Q _C ) And anode electricity (Q _A ) (Q) _C / Q _A ) Is 0.95, duty is 0.50, frequency is 60 Hz, and the total amount of electricity at the time of anode is 200 C / dm ² Met. Thereafter, washing with water was performed by spraying.
Concentration control of nitric acid aqueous solution is done by adding 67% by mass of nitric acid stock solution and water in proportion to the amount of energization. And discharged outside the electrolyzer system. Along with this, referring to a table created in advance from the relationship between nitric acid concentration, aluminum ion concentration, temperature, liquid conductivity, and liquid ultrasonic propagation speed, the temperature, conductivity, and ultrasonic propagation speed of the aqueous nitric acid solution The concentration of the aqueous nitric acid solution was determined, and the concentration was kept constant by controlling the addition amount of the nitric acid stock solution and water sequentially.
[0149]
(5) Alkali etching treatment
An aqueous solution having a liquid temperature of 45 ° C. containing 26% by mass of NaOH and 6.5% by mass of aluminum ions was sprayed onto the aluminum plate using a spray to perform an alkali etching treatment. The dissolution amount of the aluminum plate is 0.3 g / m ² Met. The concentration of the etching solution is determined in advance by referring to a table created from the relationship between the NaOH concentration, the aluminum ion concentration, the temperature, the specific gravity, and the conductivity of the solution. The concentration of the etching solution is obtained from the temperature, the specific gravity, and the conductivity. A 48% by weight aqueous NaOH solution was added to keep it constant. Then, it washed with water.
[0150]
(6) Acid etching treatment
Sulfuric acid (sulfuric acid concentration 300 g / L, aluminum ion concentration 15 g / L) was used as an acidic etching solution, and this was sprayed from an spray plate to an aluminum plate at 80 ° C. for 8 seconds to perform acidic etching treatment. The acid etchant concentration is determined by referring to a table created in advance from the relationship between sulfuric acid concentration, aluminum ion concentration, temperature, specific gravity, and liquid conductivity. Water and 50% by weight sulfuric acid were added under control to keep constant. Then, it washed with water.
[0151]
Roughening treatment method B
In the surface roughening treatment method B, in the above (1), the diameter of the nylon brush bristles is 0.25 mm, the average particle size of the abrasive pumice is 25 μm, and R _a Was carried out in the same manner as in the surface roughening treatment method A, except that the thickness was 0.35 μm.
[0152]
Roughening treatment method C
In the surface roughening treatment method C, in (1) above, the diameter of the nylon brush bristles is 0.57 mm, and the five nylon brushes (the distance between the two support rollers (φ200 mm) provided at the lower part of the brush is 300 mm. ) And R _a Was carried out in the same manner as in the surface roughening treatment method A, except that the thickness was changed to 0.58 μm.
[0153]
Surface roughening treatment method D
In the surface roughening treatment method D, in the above (4), a 5.0 g / L hydrochloric acid aqueous solution (including 5 g / L of aluminum ions) is used as the acidic aqueous solution, the liquid temperature is 35 ° C., and tp and tp ′ are set to 0.00. 8msec, current density 25A / dm ² , Duty is 0.50, the total amount of electricity at the time of anode is 50 C / dm ² Except that, it was carried out in the same manner as the surface roughening treatment method A.
Note that ferrite was used for the auxiliary anode.
[0154]
Roughening treatment method E
In the surface roughening treatment method E, the dissolution amount of the aluminum plate is 1.0 g / m in (5) of the surface roughening treatment method A. ² Except that, it was carried out in the same manner as the surface roughening treatment method A.
[0155]
Surface roughening treatment method F
The surface roughening treatment method F was performed in the same manner as the surface roughening treatment method A except that the liquid temperature of the acidic aqueous solution was changed to 30 ° C. in the above (4).
[0156]
Roughening treatment method G
The surface roughening treatment method G is the same as in (5) of the surface roughening treatment method A, but the dissolution amount of the aluminum plate is 0.1 g / m. ² Except that, it was carried out in the same manner as the surface roughening treatment method A.
[0157]
Roughening treatment method H
The roughening treatment method H was performed in the same manner as the roughening treatment method A, except that the above (1) was not performed.
[0158]
Roughening treatment method I
The roughening treatment method I is the above (1), in which the diameter of the nylon brush hair is 0.85 mm, R _a Was performed in the same manner as in the surface roughening treatment method A, except that the thickness was changed to 0.75 μm.
[0159]
Roughening treatment method J
The roughening treatment method J was performed in the same manner as the roughening treatment method A, except that the above (4) was not performed.
[0160]
Roughening treatment method K
In the surface roughening treatment method K, the amount of dissolution of the aluminum plate is 1.5 g / m in (5) of the surface roughening treatment method A. ² Except that, it was carried out in the same manner as the surface roughening treatment method A.
[0161]
Roughening treatment method L
The roughening treatment method L was performed in the same manner as the roughening treatment method A, except that the above (5) was not performed.
[0162]
<Hydrophilic film forming method>
Method for forming hydrophilic film (a)
Following the roughening treatment, the following hydrophilic film forming method was sequentially performed to provide a hydrophilic film to obtain an aluminum support.
[0163]
(7) Anodizing treatment
An anodized film was formed by anodizing the aluminum plate with an aqueous solution (containing 0.5 mass% of aluminum ions) having an oxalic acid concentration of 50 g / L at a temperature of 30 ° C. and an anodizing time of 150 seconds. As for the concentration of the anodizing solution, refer to the table created in advance from the relationship between the oxalic acid concentration, aluminum ion concentration, temperature, specific gravity, and liquid conductivity, obtain the liquid concentration from the temperature, specific gravity, and conductivity, and feed back Water and oxalic acid were added under control to keep constant. Thereafter, washing with water was performed by spraying.
[0164]
(8) Pore wide processing
The anodized aluminum plate was immersed in a pH 13 NaOH aqueous solution at 50 ° C. for 1 minute to perform pore-wide treatment.
[0165]
(9) Sealing treatment
It was immersed in a 1% by weight aqueous solution of colloidal silica (Nissan Chemical Industry Co., Ltd., Snowtex ST-N, particle size of about 20 nm) at 70 ° C. for 14 seconds and then washed with water.
[0166]
(10) Hydrophilic surface treatment
Hydrophilic surface treatment was performed by treating with No. 3 sodium silicate concentration 2.5 mass% aqueous solution at 70 ° C. for 12 seconds.
Thereafter, it was washed with water and dried to obtain an aluminum support.
[0167]
Method for forming hydrophilic film (b)
The same treatment as in the hydrophilic film forming method (a) was performed except that the anodic oxidation time was 120 seconds in (7) and the immersion time was 120 seconds in (8).
[0168]
Hydrophilic film forming method (c)
The following treatment was performed in place of (7) anodizing treatment of the hydrophilic film forming method (a).
Sulfuric acid concentration 170 g / L (including 0.5% by mass of aluminum ions), current density 5 A / dm ² The aluminum plate was anodized under conditions of a temperature of 30 ° C. for 70 seconds and washed with water. Next, it was immersed in an aqueous sodium hydroxide solution having a pH of 13 and a liquid temperature of 30 ° C. for 30 seconds, and then washed with water.
Next, the treatments (9) and (10) of the hydrophilic film forming method (a) were performed.
[0169]
Method for forming hydrophilic film (d)
The same treatment as in the hydrophilic film forming method (a) was performed except that the anodic oxidation time was 120 seconds in (7) and the immersion time was 180 seconds in (8).
[0170]
Hydrophilic film forming method (e)
In the said hydrophilic membrane | film formation method (c), the process similar to the hydrophilic membrane | film formation method (c) was performed except not having performed the process by sodium hydroxide aqueous solution.
[0171]
2. Measurement of thermal conductivity in the film thickness direction
The thermal conductivity in the film thickness direction of the film of the aluminum support obtained above was measured by the following method.
First, two types of aluminum supports having different film thicknesses from the aluminum supports of Examples and Comparative Examples were prepared for each of the Examples and Comparative Examples. That is, the anodizing time in the hydrophilic film forming method was 0.5 times and 2 times, and other than that, aluminum supports having different film thicknesses were prepared in the same manner as the aluminum supports.
Next, three types of aluminum supports having different film thicknesses were subjected to measurement using the apparatus shown in FIG. 3, and the thermal conductivity in the film thickness direction of the film was calculated from the following equation [1]. The measurement was performed at five different points on the sample, and the average value was used.
The results are shown in Tables 2 and 3.
[0172]
[Expression 2]

[0173]
3. Measurement of AD amount (mass per unit area of anodized film)
A hydrophilic layer (including an anodized film) was dissolved in the aluminum support according to JIS H8688-1998, and the mass per unit area was measured (commonly known as the Mason method). The measurement was performed using five test pieces of 20 cm × 10 cm, and the average value was taken as the AD amount. The standard deviation was 0.03 or less.
The results are shown in Tables 2 and 3.
[0174]
4). Measurement of thickness (t) of hydrophilic film
The side surface (usually the fracture surface) of the cracked portion generated when the aluminum substrate was bent was observed using an ultra-high resolution SEM (Hitachi S-900). The observation was performed at a magnification of 50000 times at a relatively low acceleration voltage of 12 kV and without performing a vapor deposition treatment for imparting conductivity. The average value of the measured values obtained by randomly extracting 50 cross sections was defined as the thickness (t) of the hydrophilic film. The standard deviation error was ± 10% or less.
The results are shown in Tables 2 and 3.
[0175]
5). Density measurement
From the AD amount (m) obtained in 8 and 9 above and the thickness (t) of the hydrophilic film, the density (d) of the hydrophilic layer (including the anodized film) was determined by the following formula.
d [g / cm ³ ] = M [g / m ² ] / T [μm]
The results are shown in Tables 2 and 3.
[0176]
6). Porosity measurement
From the density (d) determined above, the porosity of the hydrophilic layer (including the anodized film) was determined by the following formula.
Porosity (%) = (1− (d / 3.98)) × 100
3.98 is the density of aluminum oxide (g / cm) according to “Chemical Handbook” (Maruzen) edited by Chemical Society of Japan. ³ ).
The results are shown in Tables 2 and 3.
[0177]
7). Measurement of Si content
The amount of Si on the surface of the aluminum support was measured by a calibration curve method using a fluorescent X-ray analyzer. As a standard sample for preparing a calibration curve, a sodium silicate aqueous solution containing a known amount of Si atoms was uniformly dropped into an area of 30 mmφ on an aluminum substrate and then dried.
Conditions for X-ray fluorescence analysis of Si are shown below.
X-ray fluorescence analyzer: RIX3000 manufactured by Rigaku Corporation, X-ray tube: Rh, measurement spectrum: Si-Kα, tube voltage: 50 kV, tube current: 50 mA, slit: COARSE, spectral crystal: RX4, detector: F -PC, analysis area: 30 mmφ, peak position (2θ): 144.75 deg. , Background (2θ): 140.70 deg. And 146.85 deg. Integration time: 80 seconds / sample
The results are shown in Tables 2 and 3.
[0178]
8). Preparation of lithographic printing plate precursor
Each aluminum support obtained above was provided with an undercoat layer (shown as an intermediate layer in Tables 2 and 3) and a photosensitive layer having the following composition to form a lithographic printing plate precursor.
An undercoat solution having the following composition was applied on an aluminum support and dried at 80 ° C. for 15 seconds to form a coating film. The coating amount after drying is 15 mg / m ² Met.
<Undercoat liquid composition>
The following polymer compound 0.3g
Methanol 100 g
1 g of water
[0179]
[Chemical 2]

[0180]
Further, a photosensitive layer coating solution 1 having the following composition was prepared, and the coating amount after drying (photosensitive layer coating amount) of the photosensitive layer coating solution 1 on a subbed aluminum support using a bar coater was 1.0 g / m ² And dried to form a photosensitive layer to obtain a lithographic printing plate.
[0181]

[0182]
[Chemical 3]

[0183]
<Specific copolymer 1>
In a 500 mL three-necked flask equipped with a stirrer, a condenser, and a dropping funnel, 31.0 g (0.36 mol) of methacrylic acid, 39. 1 g (0.36 mol) and 200 mL of acetonitrile were added, and the mixture was stirred while cooling with an ice-water bath. To this mixture, 36.4 g (0.36 mol) of triethylamine was dropped with a dropping funnel over about 1 hour. After completion of the dropwise addition, the ice-water bath was removed, and the mixture was stirred at room temperature for 30 minutes.
[0184]
To this reaction mixture, 51.7 g (0.30 mol) of p-aminobenzenesulfonamide was added, and the mixture was stirred for 1 hour while warming to 70 ° C. in an oil bath. After completion of the reaction, this mixture was added to 1 L of water with stirring, and the resulting mixture was stirred for 30 minutes. The mixture was filtered to take out a precipitate, which was slurried with 500 mL of water, and then the slurry was filtered. The obtained solid was dried to dry a white solid of N- (p-aminosulfonylphenyl) methacrylamide. Was obtained (yield 46.9 g).
[0185]
Next, 4.61 g (0.0192 mol) of N- (p-aminosulfonylphenyl) methacrylamide and 2.94 g of ethyl methacrylate were added to a 20 mL three-necked flask equipped with a stirrer, a condenser, and a dropping funnel. 0.0258 mol), 0.80 g (0.015 mol) of acrylonitrile and 20 g of N, N-dimethylacetamide were added, and the mixture was stirred while being heated to 65 ° C. with a hot water bath. To this mixture, 0.15 g of “V-65” (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was stirred for 2 hours under a nitrogen stream while being kept at 65 ° C. A further mixture of 4.61 g of N- (p-aminosulfonylphenyl) methacrylamide, 2.94 g of ethyl methacrylate, 0.80 g of acrylonitrile, N, N-dimethylacetamide and 0.15 g of “V-65” was added to this reaction mixture. It dropped by the dropping funnel over 2 hours. After completion of the dropwise addition, the obtained mixture was further stirred at 65 ° C. for 2 hours. After completion of the reaction, 40 g of methanol was added to the mixture, cooled, and the resulting mixture was poured into 2 L of water while stirring the water. After stirring the mixture for 30 minutes, the precipitate was removed by filtration and dried. 15 g of the specific copolymer 1 as a white solid was obtained.
It was 53,000 (polystyrene standard) when the weight average molecular weight of the obtained specific copolymer 1 was measured by the gel permeation chromatography.
[0186]
V-65
[Formula 4]

[0187]
The following measurements and tests were performed, and the results are shown in Tables 2 and 3.
[0188]
9. Average wave diameter of medium wave
After the lithographic printing plate was dissolved and removed with γ-butyllactone to expose the support, the support surface was observed by SEM from the vertical direction at a magnification of 10,000 times, and the pit diameter was measured at 30 points on the photographed photo. The average value was defined as the average opening diameter. At this time, Hitachi S-900 was used.
[0189]
10. Average wavelength of large wave
After the lithographic printing plate was removed by dissolving the photosensitive layer with γ-butyllactone to expose the support, the surface was observed at a magnification of 2000 using a J-20 T-20 scanning electron microscope. The component was read 30 points each in the horizontal direction and in the direction perpendicular thereto, and the average value was defined as the average wavelength.
[0190]
11. Average ratio of depth to diameter of medium wave structure
The average ratio of the depth of the medium wave structure to the opening diameter was obtained by taking a fracture surface of the support at a magnification of 50000 times using a high-resolution SEM and extracting 20 pieces from the obtained SEM photograph. Was read to obtain a ratio, and an average value was calculated.
[0191]
12 Evaluation of lithographic printing plate sensitivity
The lithographic printing plate obtained as described above was exposed using a TrendSetter 3244 manufactured by CREO, with the plate surface energy amount changed by changing the exposure output, and then developed by the development method described below. Immediately before the increase, that is, the plate surface energy of the minimum laser beam capable of forming an image was used as an index of sensitivity.
Development method: A developer DT-1 for PS plate manufactured by Fuji Film (developer not containing Si) was developed under standard conditions using an automatic processor 900NP.
[0192]
13. Dirt resistance evaluation
Plate energy amount 140 mJ / cm using TrendSetter 3244 manufactured by CREO ² And then developed in the same manner as in 12 above. Using a Mitsubishi diamond type F2 printing machine, the blanket was visually evaluated after printing on 10,000 sheets of DIC GEOS Red (s). The evaluation was made in five stages of ◎, ○ ◎, ○, △, and × in order from the least dirty.
[0193]
14 Evaluation of printing durability
After printing in the same manner as the smudge evaluation, printing was performed with a Komori Corporation Lithlon printer. The ink used was DIC GEOS black (N). The printing durability was determined by the number of printed sheets on which the density of the solid portion started to decrease on the printed material.
[0194]
[Table 2]

[0195]
[Table 3]

[0196]
[Table 4]

[0197]
[Table 5]

[0198]
【The invention's effect】
Since the aluminum support of the present invention has a hydrophilic film having a thermal conductivity in the film thickness direction of 0.05 to 0.5 W / (m · K), when the exposure amount of the infrared laser is low, or a developer Even when the liquid feeling is low, the solubility in the developer is increased. As a result, the sensitivity is high, the development latitude is wide, the remaining film is small even at low exposure, and the non-image area is less likely to be stained.
In particular, the lithographic printing plate precursor according to the present invention has a hydrophilic property having a specific range of thermal conductivity on an aluminum support having a double-grained grain shape in which a structure having a specific average wavelength (aperture diameter) is superimposed. By providing a specific heat-sensitive layer after coating, heat can be efficiently used for image formation, high sensitivity, high printing durability, and non-image area stains are unlikely to occur. A lithographic printing plate precursor.
[Brief description of the drawings]
FIG. 1 is a waveform diagram showing an example of a trapezoidal wave used for electrochemical surface roughening treatment using alternating current that is preferably used in the present invention.
FIG. 2 is a side view showing an example of a radial type cell in an electrochemical roughening process preferably used in the present invention.
FIG. 3 is a schematic view of a thermocomparator that can be used for measuring the thermal conductivity in the film thickness direction of the hydrophilic film of the lithographic printing plate precursor according to the invention.
[Explanation of symbols]
11 Aluminum plate
12 Radial drum roller
13a, 13b Main pole
14 acidic aqueous solution
15 Solution supply port
16 slits
17 Solution passage
18 Auxiliary anode
19a, 19b Thyristor
20 AC power supply
21 Main electrolytic cell
22 Auxiliary anode tank
30 Thermo Comparator
31 chips
32 Reservoir
33 Electric heater
34 Heating jacket
35 Thermocouple
36 heat sink
37 film
38 Metal substrate
39 Contact thermometer
40 Tip tip temperature recorder
41 Heat sink temperature recorder
42 Reservoir temperature recorder

Claims (4)

It has a grained shape with a superposed structure including a large wave structure with an average wavelength of 2 to 30 μm and a medium wave structure with an average opening diameter of 0.05 to 5 μm, with respect to the opening diameter of the medium wave structure with an average opening diameter of 0.05 to 5 μm. On an aluminum support with an average depth ratio of 0.1 to 1.0,
After providing a hydrophilic film having a thermal conductivity of 0.05 to 0.5 W / (m · K),
A lithographic printing plate precursor comprising a heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared absorbing dye and having increased solubility in an alkaline aqueous solution upon heating. It has a grained shape with a superposed structure including a large wave structure with an average wavelength of 2 to 30 μm and a medium wave structure with an average opening diameter of 0.05 to 5 μm, with respect to the opening diameter of the medium wave structure with an average opening diameter of 0.05 to 5 μm. After providing a hydrophilic film having a density of 1.0 to 3.2 g / cm ³ or a porosity of 20 to 70% on an aluminum support having an average depth ratio of 0.1 to 1.0,
A lithographic printing plate precursor comprising a heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared absorbing dye and having increased solubility in an alkaline aqueous solution upon heating. The lithographic printing plate precursor as claimed in claim 1 or 2, wherein the hydrophilic film is an anodized film formed by an anodizing treatment. The lithographic printing plate precursor as claimed in any one of claims 1 to 3, wherein the hydrophilic film is further treated with an alkali metal silicate.

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