JP2004017404A - Support for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support for a lithographic printing plate which is best-suitably used for an original plate of the lithographic printing plate keeping outstanding resistance to plate wear, resistance to dirt and exposure stability at a high level and well-balanced when the lithographic printing plate is manufactured. <P>SOLUTION: The support for the lithographic printing plate is obtained by roughing and anodizing the surface of an aluminum plate and has an average centerline roughness R<SB>a</SB>of 0.35 μm or more and a maximum surface height R<SB>max</SB>of 8.0 μm or less. The aluminum plate has the specific amounts of Fe, Si, Cu, Ti, Pb and Ni and 7,000 pieces/mm<SP>2</SP>or less of an intermetallic compound with a circle equivalent diameter of l μm or more and the ratio of 85% or more of the intermetallic compound with the circle equivalent diameter of l to l0 μm, with regard to the intermetallic compound composed of two or more kinds of the described metallic elements present on the surface of the aluminum plate. The aluminum plate has 0.0l mass% or less of a single substance Si present in the plate. <P>COPYRIGHT: (C)2004,JPO

Description

【０２０７】
【表２】

【０２０８】
２．平版印刷版用支持体の製造
各アルミニウム板１〜２６に、下記の表面処理Ａ〜Ｆのいずれかを施し、各平版印刷版用支持体を得た。
アルミニウム板１〜２６に、表面処理Ａを施して得た支持体を実施例１−１〜１−１３および比較例１−１〜１−１３とし、アルミニウム板１〜１３に表面処理Ｂを施して得た支持体を実施例２−１〜２−１３とし、アルミニウム板１〜１３に表面処理Ｃを施して得た支持体を比較例２−１〜２−１３とし、アルミニウム板１〜１３に表面処理Ｄを施して得た支持体を比較例３−１〜３−１３とし、アルミニウム板１〜１３に表面処理Ｅを施して得た支持体を比較例４−１〜４−１３とし、アルミニウム板１〜１３に表面処理Ｆを施して得た支持体を比較例５−１〜５−１３とした。
【０２０９】
（１）表面処理Ａ
表面処理Ａは、下記（ａ）〜（ｌ）の各処理を連続的に行うことにより行った。なお、各工程の粗面化処理の後には水洗処理を行った。粗面化処理および水洗処理の後にはニップローラによる液切りを行った。また、同じ種類の液を使った処理が連続して行われるケースでは、その工程の間での水洗は省略した。
【０２１０】
＜機械的粗面化処理（ａ）＞
平均粒径１２μｍのパミスを研磨材として含有する研磨材スラリー（比重１．０８）を、スプレー管にてアルミニウム板の表面に供給しながら、回転するローラ状ナイロンブラシにより機械的粗面化処理を行った。
ローラ状ブラシにおけるブラシ毛の材質は６・１０ナイロンであった。上記ブラシ毛は、直経３００ｍｍのステンレス製の筒に穴をあけて密になるように植毛した。ローラ状ブラシは３本使用した。上記ローラ状ブラシのそれぞれに２本の支持ローラを設けた。上記支持ローラの直径は２００ｍｍであり、距離は３００ｍｍであった。ブラシ毛の直径は０．５ｍｍであり、毛長は３００ｍｍであった。
【０２１１】
上記ローラ状ブラシの押し込み量は、上記ローラ状ブラシを回転させる駆動モータの負荷の、上記ローラ状ブラシを押し付ける前の前期駆動モータの負荷に対する増大量が一定になり、かつ、粗面化処理後のアルミニウム板の平均表面粗さが０．４〜０．５μｍになるように制御した。オシレートの振幅は１００ｍｍであった。
【０２１２】
上記機械的粗面化処理においては、上記研磨材スラリーを一定の時間間隔で採取して比重を測定し、上記比重の変動幅が±１０％以内になるように研磨材を補充して研磨材濃度を制御した。
【０２１３】
＜アルカリエッチング処理（ｂ）＞
機械的粗面化処理後のアルミニウム板に、スプレー管から、ＮａＯＨ１８質量％およびアルミニウムイオン７．５質量％を含有するアルカリ溶液（６０℃）を噴き付けて、粗面化面におけるアルミニウム溶解量が８ｇ／ｍ^２になるようにアルカリエッチング処理を行った。
なお、上記アルカリ溶液の濃度の制御については、上記スプレー管に供給されるアルカリ溶液を一定の時間間隔で採取して比重と導電度とを測定し、上記比重および導電度の変動幅が±１０％以内になるように上記アルカリ溶液に水または水酸化ナトリウムを補充することにより行った。
【０２１４】
＜デスマット処理（ｃ）＞
液温３０℃、硝酸濃度１質量％の酸性溶液を用いて行った。デスマット液はスプレーにて噴き付けて２秒間デスマット処理を行った。
【０２１５】
＜電気化学的粗面化処理（硝酸電解処理）（ｄ）＞
液温４０℃、硝酸濃度１質量％の硝酸水溶液に硝酸アルミニウムを添加してアルミニウムイオン濃度を０．５質量％に調整した硝酸電解液中で、図２に示す電解槽を使用し、図１に示す波形の台形波電流を印加して電気化学的粗面化処理を行った。上記台形波電流の周波数は６０Ｈｚであり、上記アルミニウム板のアノード反応時の電気量２２０Ｃ／ｄｍ^２、および電流密度は交流のピーク時でアルミニウム板のアノード反応時２５Ａ／ｄｍ^２であった。交流のｄｕｔｙ（ｔａ／Ｔ）は０．５であり、立上り時間ｔｐ’およびｔｐは０．３ｍｓｅｃであった。カーボンの主極に対向する部分でのアルミニウム板がアノード反応時の電気量の総和Ｑａとカソード反応時の電気量総和Ｑｃとの比Ｑｃ／Ｑａは０．９５であった。アルミニウム板に加わる電気量は、アルミニウム板が電解槽を通過する間にアルミニウム板に加わった電気量であって上記アルミニウム板がアノード反応した電気量の総和である。
【０２１６】
上記硝酸電解液の硝酸濃度は、一定の時間間隔で上記硝酸電解液の音速と電導度とを測定し、上記音速と電導度との変動幅が±１０％以内になるように濃硝酸または水を補充して制御した。
【０２１７】
＜アルカリエッチング処理（ｅ）＞
機械的粗面化処理後のアルミニウム板に、スプレー管から、ＮａＯＨ２０質量％およびアルミニウムイオン７．５質量％を含有するアルカリ溶液（３５℃）を噴き付けて、粗面化面におけるアルミニウム溶解量が０．９ｇ／ｍ^２になるようにアルカリエッチング処理を行った。
【０２１８】
アルカリエッチング処理（ｂ）と同様の方法で上記アルカリ溶液の水酸化ナトリウムの濃度を制御した。
【０２１９】
＜デスマット処理（ｆ）＞
液温４０℃、硫酸濃度１５質量％の酸性溶液を用いてスプレーにて噴き付けて２秒間デスマット処理を行った。
【０２２０】
＜電気化学的粗面化処理（塩酸電解処理）（ｇ）＞
液温３０℃、塩酸濃度０．２質量％、アルミニウムイオン濃度０．５質量の塩酸水溶液中で、図２に示す電解槽を使用し、図１に示す波形の台形波電流を印加して電気化学的粗面化処理を行った。上記台形波電流の周波数は６０Ｈｚであり、上記アルミニウム板のアノード反応時の電気量３０Ｃ／ｄｍ^２、および電流密度は交流のピーク時でアルミニウム板のアノード反応時２５Ａ／ｄｍ^２であった。交流のｄｕｔｙ（ｔａ／Ｔ）は０．５であり、立上り時間ｔｐ’およびｔｐは０．５ｍｓｅｃであった。カーボンの主極に対向する部分でのアルミニウム板がアノード反応時の電気量の総和Ｑａとカソード反応時の電気量総和Ｑｃとの比Ｑｃ／Ｑａは０．９５であった。アルミニウム板に加わる電気量は、アルミニウム板が電解槽を通過する間にアルミニウム板に加わった電気量であって上記アルミニウム板がアノード反応した電気量の総和である。
【０２２１】
上記塩酸電解液の塩酸濃度は、一定の時間間隔で上記塩酸電解液の音速と電導度とを測定し、上記音速と電導度との変動幅が±１０％以内になるように濃塩酸または水を補充して制御した。
【０２２２】
＜アルカリエッチング処理（ｈ）＞
機械的粗面化処理後のアルミニウム板に、スプレー管からＮａＯＨ濃度４質量％のアルカリ溶液（４５℃）を噴き付けて、粗面化面におけるアルミニウム溶解量が０．１ｇ／ｍ^２になるようにアルカリエッチング処理を行った。
なお、アルカリエッチング処理（ｂ）と同様の方法で上記アルカリ溶液の水酸化ナトリウムの濃度を制御した。
【０２２３】
＜デスマット処理（ｉ）＞
液温３０℃、硫酸濃度１０質量％の酸性溶液を用いて、スプレーにて噴き付けて４秒間デスマット処理を行った。
【０２２４】
＜陽極酸化処理（ｊ）＞
硫酸濃度１０質量％、液温３０℃の硫酸溶液中で直流を印加して陽極酸化処理し、表面の皮膜量が２．６ｇ／ｍ^２になるように陽極酸化皮膜を形成した。
なお、陽極酸化処理に使用した硫酸溶液を一定時間毎に採取して比重と電導度とを測定し、上記比重および電導度の変動幅が±１０％以内になるように濃硫酸または水を補充して上記硫酸溶液の硫酸濃度を制御した。
【０２２５】
＜封孔処理（ｋ）＞
１００℃１気圧において飽和した蒸気チャンバーの中で１０秒間蒸気封孔処理した。
【０２２６】
＜親水化処理（ｌ）＞
ケイ酸ナトリウム１質量％水溶液で４０℃で７秒間浸せき処理し、親水化処理を行った。その後、乾燥させた。
【０２２７】
（２）表面処理Ｂ
各処理において以下のように条件を変更した以外は、表面処理Ａと同様にして表面処理Ｂを行った。
【０２２８】
＜アルカリエッチング処理（ｂ）＞
アルカリ溶液のＮａＯＨ濃度を２３質量％とし、アルミニウム板の溶解量を９ｇ／ｍ^２とした。
＜デスマット処理（ｃ）＞
酸性溶液の硝酸濃度を０．８質量％とした。
＜電気化学的粗面化処理（硝酸電解処理）（ｄ）＞
硝酸電解液の液温を４５℃とし、電流密度を３０Ａ／ｄｍ^２とし、アルミニウム板に加わる電気量を１９５Ｃ／ｄｍ^２とした。
＜アルカリエッチング処理（ｅ）＞
アルカリ溶液のＮａＯＨ濃度を２４質量％とし、アルミニウム板の溶解量を７．８ｇ／ｍ^２とした。
＜電気化学的粗面化処理（塩酸電解処理）（ｇ）＞
円酸水溶液の液温を３５℃とし、塩酸濃度を０．４質量％とし、電流密度を２０Ａ／ｄｍ^２とし、電気量の総和を２６Ｃ／ｄｍ^２とした。
＜アルカリエッチング処理（ｈ）＞
アルミニウム板の溶解量を０．００１ｇ／ｍ^２とした。
【０２２９】
（３）表面処理Ｃ
各処理において以下のように条件を変更した以外は、表面処理Ａと同様にして表面処理Ｃを行った。
【０２３０】
＜機械的粗面化処理（ａ）＞
パミスの粒子の平均粒径を０．８μｍとした。
＜アルカリエッチング処理（ｂ）＞
アルカリ溶液のＮａＯＨ濃度を２５質量％とした。
＜電気化学的粗面化処理（硝酸電解処理）（ｄ）＞
電流密度を４Ａ／ｄｍ^２とし、アルミニウム板に加わる電気量を１７０Ｃ／ｄｍ^２とした。
＜アルカリエッチング処理（ｅ）＞
アルミニウム板の溶解量を０．２ｇ／ｍ^２とした。
＜電気化学的粗面化処理（塩酸電解処理）（ｇ）＞
塩酸水溶液の塩酸濃度を０．８質量％とし、電流密度を３Ａ／ｄｍ^２とし、電気量の総和を５０Ｃ／ｄｍ^２とした。
＜アルカリエッチング処理（ｈ）＞
アルカリ溶液のＮａＯＨ濃度を９質量％とし、アルミニウム板の溶解量を０．０１ｇ／ｍ^２とした。
＜デスマット処理（ｉ）＞
酸性溶液の硫酸濃度を３０質量％とし、液温を６０℃とした。
【０２３１】
（４）表面処理Ｄ
各処理において以下のように条件を変更した以外は、表面処理Ａと同様にして表面処理Ｄを行った。
【０２３２】
＜機械的粗面化処理（ａ）＞
パミスの粒子の平均粒径を０．８μｍとした。
＜アルカリエッチング処理（ｂ）＞
アルカリ溶液のＮａＯＨ濃度を２７質量％とし、アルミニウム板の溶解量を９ｇ／ｍ^２とした。
＜電気化学的粗面化処理（硝酸電解処理）（ｄ）＞
硝酸水溶液の硝酸濃度を１．５質量％とし、電流密度を４５Ａ／ｄｍ^２とし、アルミニウム板に加わる電気量を２００Ｃ／ｄｍ^２とした。
＜アルカリエッチング処理（ｅ）＞
アルカリ溶液のＮａＯＨ濃度を１５質量％とし、アルミニウム板の溶解量を２ｇ／ｍ^２とした。
＜電気化学的粗面化処理（塩酸電解処理）（ｇ）＞
塩酸水溶液の塩酸濃度を１．５質量％とし、アルミニウムイオン濃度を０．３質量％とし、電流密度を３５Ａ／ｄｍ^２とし、電気量の総和を５Ｃ／ｄｍ^２とした。
＜デスマット処理（ｉ）＞
酸性溶液の硫酸濃度を１５質量％とした。
【０２３３】
（５）表面処理Ｅ
各処理において以下のように条件を変更した以外は、表面処理Ａと同様にして表面処理Ｅを行った。
【０２３４】
＜機械的粗面化処理（ａ）＞
パミスの粒子の平均粒径を７５μｍとした。
＜アルカリエッチング処理（ｂ）＞
アルカリ溶液のＮａＯＨ濃度を２０質量％とし、アルミニウム板の溶解量を９ｇ／ｍ^２とした。
＜電気化学的粗面化処理（硝酸電解処理）（ｄ）＞
硝酸水溶液の硝酸濃度を１．８質量％とし、アルミニウム板に加わる電気量を９００Ｃ／ｄｍ^２とした。
＜アルカリエッチング処理（ｅ）＞
アルミニウム板の溶解量を２．５ｇ／ｍ^２とした。
＜電気化学的粗面化処理（塩酸電解処理）（ｇ）＞
電気量の総和を１５Ｃ／ｄｍ^２とした。
＜デスマット処理（ｉ）＞
酸性溶液の硫酸濃度を１５質量％とし、液温を５０℃とした。
【０２３５】
（６）表面処理Ｆ
各処理において以下のように条件を変更した以外は、表面処理Ａと同様にして表面処理Ｆを行った。
【０２３６】
＜機械的粗面化処理（ａ）＞
パミスの粒子の平均粒径を７５μｍとした。
＜アルカリエッチング処理（ｂ）＞
アルカリ溶液のＮａＯＨ濃度を２０質量％とし、アルミニウム板の溶解量を８１０ｇ／ｍ^２とした。
＜電気化学的粗面化処理（硝酸電解処理）（ｄ）＞
アルミニウム板に加わる電気量を２００Ｃ／ｄｍ^２とした。
＜アルカリエッチング処理（ｅ）＞
アルミニウム板の溶解量を２ｇ／ｍ^２とした。
＜電気化学的粗面化処理（塩酸電解処理）（ｇ）＞
塩酸水溶液の塩酸濃度を０．９質量％とし、アルミニウムイオン濃度を０．７質量％とし、電気量の総和を６０Ｃ／ｄｍ^２とした。
＜アルカリエッチング処理（ｈ）＞
アルカリ溶液のＮａＯＨ濃度を５質量％とし、アルミニウム板の溶解量を０．９ｇ／ｍ^２とした。
＜デスマット処理（ｉ）＞
酸性溶液の硫酸濃度を１５質量％とし、液温を６０℃とした。
【０２３７】
３．平版印刷版用支持体の表面形状
得られた平版印刷版用支持体の中心線平均粗さＲ_ａおよび最大高さＲ_ｍａｘを以下のようにして測定した。実施例１−１〜１−１３および比較例１−１〜１−１３についての結果を第２表に示す。
【０２３８】
（１）中心線平均粗さＲ_ａ
触針式粗さ計（例えば、ｓｕｆｃｏｍ５７５、東京精密社製）で２次元粗さ測定を行い、ＩＳＯ４２８７に規定されている平均粗さを５回測定し、その平均値を中心線平均粗さＲ_ａとした。
２次元粗さ測定の条件は、カットオフ値０．８ｍｍ、傾斜補正ＦＬＡＴ−ＭＬ、測定長３ｍｍ、縦倍率１００００倍、走査速度０．３ｍｍ／ｓｅｃ、触針先端径２μｍとした。
【０２３９】
（２）最大高さＲ_ｍａｘ
触針式粗さ計（例えば、Ｓｕｒｆｃｏｍ５７５、東京精密社製）で２次元粗さ測定を行い、ＪＩＳ　Ｂ０６０１−１９９４に準拠して測定した。
２次元粗さ測定の条件は、カットオフ値０．８ｍｍ、評価長さ３．０ｍｍ、基準長さ３．０ｍｍ、走査速度０．３ｍｍ／ｓｅｃ、触針径２μｍとした。
【０２４０】
得られた平版印刷版用支持体の製造過程（硝酸電解処理後および塩酸電解処理後）におけるピットの均一性を下記の方法で評価した。結果を第２表に示す。
【０２４１】
（３）硝酸電解処理（ｄ）で生成するピットの均一性
上記電気化学的粗面化処理（硝酸電解処理）（ｄ）の後、硫酸溶液でデスマット処理して、ＥＭＰＡ（日本電子社製、ＪＥＯＬ　ＳＵＰＥＲＰＲＯＢＥ　ＪＸＡ−８８００Ｍ）を用いて、加速電圧２０．０ｋＶ、照射電流９．５×１０^−９Ａの条件で高感度反射電子検出器を用いて、組成像を倍率１５００倍で撮影した。得られたインスタント写真から目視によりピットの均一性を評価した。
ピットが均一であったものを「均一」、不均一であったものを「不均一」とし、その中間を「やや不均一」とし、生成したピットが溶解していたものを「ピット溶解」とした。
【０２４２】
（４）塩酸電解処理（ｇ）で生成するピットの均一性
上記電気化学的粗面化処理（塩酸電解処理）（ｇ）の後、上記（３）と同様の方法により、ピットの均一性を評価した。
【０２４３】
４．平版印刷版原版の調製
上記各平版印刷版用支持体に、画像記録層１および２を別々に設けて平版印刷版原版とした。なお、得られた各平版印刷版原版には、各画像記録層の説明の箇所に併記する画像形成処理および現像処理を施して、平版印刷版とした。
【０２４４】
（１）画像記録層１
平版印刷版用支持体上に、下記組成の下塗液を塗布し、８０℃で３０秒間乾燥させて、下塗層を形成させた。乾燥後の塗膜の被覆量は３０ｍｇ／ｍ^２であった。
【０２４５】
＜下塗液組成＞
・アミノエチルホスホン酸　　　　０．１０ｇ
・フェニルホスホン酸　　　　０．１５ｇ
・β−アラニン　　　　０．１０ｇ
・メタノール　　　４０ｇ
・純水　　　６０ｇ
【０２４６】
ついで、下記組成の感光層塗布液を調製し、下塗りした平版印刷版用支持体に、この感光層塗布液を乾燥後の塗布量（感光層塗布量）が１．６ｇ／ｍ^２になるよう塗布し、１１０℃で１分間乾燥させて感光層（コンベンショナルポジタイプの画像記録層）を形成させた。
【０２４７】
＜感光層塗布液組成＞
・１，２−ジアゾナフトキノン−５−スルホニルクロリドとピロガロール−アセトン樹脂とのエステル化物（米国特許第３，６３５，７０９号明細書の実施例１に記載されているもの）　　　０．４５ｇ
・クレゾール−ホルムアルデヒドノボラック樹脂（メタ／パラ比＝６／４、重量平均分子量３，０００、数平均分子量１，１００、未反応クレゾール０．７質量％含有）　　　　１．１ｇ
・ｍ−クレゾール−ホルムアルデヒドノボラック樹脂（重量平均分子量１，７００、数平均分子量６００、未反応クレゾール１質量％含有）　　　　０．３ｇ
・Ｎ−（ｐ−アミノスルホニルフェニル）アクリルアミド／ノルマルブチルアクリレート／ジエチレングリコールモノメチルエーテルメタクリレート共重合体（モノマーのモル比＝４０／４０／２０、重量平均分子量４０，０００、数平均分子量２０，０００）　　　　０．２ｇ
・ｐ−ノルマルオクチルフェノール−ホルムアルデヒド樹脂（米国特許第４，１２３，２７９号明細書に記載されているもの）　　０．０２１ｇ
・ナフトキノン−１，２−ジアジド−４−スルホン酸クロライド　　０．０１ｇ
・テトラヒドロ無水フタル酸　　　　０．１ｇ
・安息香酸　　　　０．０２ｇ
・４−〔ｐ−Ｎ，Ｎ−ビス（エトキシカルボニルメチル）アミノフェニル〕−２，６−ビス（トリクロロメチル）−ｓ−トリアジン　　０．０１ｇ
・４−〔ｐ−Ｎ−（ｐ−ヒドロキシベンゾイル）アミノフェニル〕−２，６−ビス（トリクロロメチル）−ｓ−トリアジン　　　　０．０２ｇ
・２−トリクロロメチル−５−（４−ヒドロキシスチリル）−１，３，４−オキサジアゾール　　　　０．０１ｇ
・ビクトリアピュアブルーＢＯＨの対アニオンを１−ナフタレンスルホン酸に置換した染料　　　　０．０２ｇ
・フッ素系界面活性剤（モディパーＦ−２００、日本油脂社製、３０質量％のメチルエチルケトンとメチルイソブチルケトンとの混合溶剤溶液）　　　　０．０６ｇ
・フッ素系界面活性剤（メガファックＦ−１７７、大日本インキ化学工業社製、２０質量％のメチルイソブチルケトン溶液）　　　０．０２ｇ
・メチルエチルケトン　　　　１５ｇ
・１−メトキシ−２−プロパノール　　　　１０ｇ
【０２４８】
更に、このようにして形成された感光層の上に、特公昭６１−２８９８６号公報の実施例１に記載されている方法に基づいて、メチルメタクリレート／エチルアクリレート／アクリル酸ソーダ（６８／２０／１２）共重合体の水溶液を静電スプレーすることによりマット層を設け、感光性平版印刷版原版を得た。
【０２４９】
平版印刷版原版を、真空焼枠中で、透明ポジティブフィルムを通して１ｍの距離から３ｋｗのメタルハライドランプにより、５０秒間露光を行った。
その後、現像液としてＳｉＯ_２／Ｎａ_２Ｏ＝１．７４（モル比）のケイ酸ナトリウムの５．２６質量％水溶液（ｐＨ１２．７）、リンス液として富士写真フイルム（株）製ＦＲ−３（１：７）を仕込んだ富士写真フイルム（株）製自動現像機スタブロン９００Ｄに通して現像処理を行い、平版印刷版を得た。
【０２５０】
（２）画像記録層２
平版印刷版用支持体上に、下記組成の感光層塗布液を塗布し、感光層を形成させた。乾燥後の塗膜の被覆量は２ｇ／ｍ^２であった。
【０２５１】
＜感光層塗布液組成＞
・１，２−ジアゾナフトキノン−５−スルホニルクロリドとピロガロール−アセトン樹脂とのエステル化物（重量平均分子量２，５００）　　　４０質量部
・フェノールホルムアルデヒド樹脂（重量平均分子量１０，０００、３核体以上の成分９０質量％）　　　７５質量部
・後述するアクリルポリマー（１）　　　３５質量部
・２−（ｐ−ブトキシフェニル）−４，６−ビス（トリクロロメチル）−ｓ−トリアジン　　　３質量部
・青色染料（オイルブルー＃６０３、オリエント化学工業社製）　　１．５質量部
・フッ素系界面活性剤（メガファックＦ−１７６、大日本インキ化学工業社製）　　０．３質量部
・メチルエチルケトン　　　１０００質量部
・プロピレングリコールモノメチルエーテル　　　　１０００質量部
【０２５２】
＜アクリルポリマー（１）の合成＞
Ｎ−（ｐ−トルエンスルホニル）メタクリルアミド６０．３ｇ、アクリロニトリル１０．０ｇおよびエチルアクリレート４６．０ｇをジメチルホルムアミド２３２．６ｇに溶解させ、窒素気流下、２，２′−アゾビス（２，４−ジメチルバレロニトリル）０．２２４ｇを重合開始剤として用い、６５℃で７時間かくはんした。反応液を放冷した後、水５Ｌ中に再沈させた。析出したポリマーをろ取し、乾燥させて、重量平均分子量５２，０００のアクリルポリマー（１）を１１０．４ｇ得た（収率９５％）。
【０２５３】
このようにして形成された感光層の上に、マット層形成用樹脂液を吹き付け塗布し乾燥させてマット層を形成させ、平版印刷版原版を得た。
マット層形成用樹脂液としては、メチルメタクリレート／エチルアクリレート／アクリル酸の共重合体（仕込質量比６５／２０／１５）の一部をナトリウム塩とした１２％水溶液を用いた。
吹き付け塗布は、回転霧化静電塗布機を用いて、霧化頭回転数２５，０００ｒｐｍ、樹脂液の送液量４０ｍＬ／分、霧化頭への印加電圧−９０ｋＶ、塗布時の周囲温度２５℃、相対湿度５０％の条件で行った。
乾燥は、吹き付け塗布した２．５秒後に塗布面に蒸気を吹き付けて湿潤させ、蒸気を吹き付けた３秒後に温度６０℃、湿度１０％の乾燥風を５秒間吹き付けることにより行った。
【０２５４】
平版印刷版原版に原稿フィルムを通して１ｍの距離から３ｋＷのメタルハライドランプにより、６０秒間露光を行った。
その後、浸せき型現像槽を有する市販の自動現像機ＰＳ−９００Ｄ（富士写真フイルム（株）製）に通して現像処理を行い、平版印刷版を得た。ここで、自動現像機の現像槽の第一浴には下記組成の現像液（ｐＨ約１２．４）を２０Ｌ仕込んで３０℃に保温し、第二浴には水道水を８Ｌ仕込み、第三浴には下記組成のフィニッシングガム液の水希釈液（フィニッシングガム液／水＝１／１）を８Ｌ仕込んで、現像処理に用いた。
【０２５５】
＜現像液組成＞
・Ｄ−サッカロース　　　　４．８質量％
・水酸化ナトリウム　　　　０．３４質量％
・炭酸ナトリウム　　　　０．７０質量％
・テトラブチルアンモニウムブロマイド　　　　０．０３質量％
・水　　　９４．１３質量％
【０２５６】
＜現像補充液（ｐＨ約１３．０）組成＞
・Ｄ−サッカロース　　　　９．７質量％
・水酸化ナトリウム　　　　１．５質量％
・炭酸ナトリウム　　　　１．０質量％
・テトラブチルアンモニウムブロマイド　　　　０．０７質量％
・水　　　８７．７３質量％
【０２５７】
＜フィニッシングガム液組成＞
・アラビアガム　　　　１．８質量％
・酵素変性馬鈴薯デンプン　　　　１８．３質量％
・酵素変性玉蜀黍デンプン　　　３．７質量％
・リン酸化ワキシー玉蜀黍デンプン　　　１．８質量％
・ジオクチルスルホコハク酸エステルのナトリウム塩　　　　０．９１質量％
・第一リン酸アンモニウム　　　　０．２７質量％
・リン酸（８５質量％）　　　　０．３７質量％
・ＥＤＴＡ−四ナトリウム塩　　　　０．２７質量％
・エチレングリコール　　　　１．８質量％
・ベンジルアルコール　　　　２．３質量％
・デヒドロ酢酸ナトリウム　　　　０．０４質量％
・エマルション型シリコン消泡剤　　　　０．０２質量％
・水　　　　６８．４２質量％
【０２５８】
＜リンス液＞
・ドデシルジフェニルエーテルジスルホン酸ナトリウム（４０質量％水溶液）６．７質量％
・ヘキサメタリン酸ナトリウム　　　　０．８質量％
・ベンジルアルコール　　　　１．５質量％
・ポリオキシエチレン（エチレンオキシド１２モル付加）ノニルフェニルエーテル　　　　１．５質量％
・ジオクチルスルホコハク酸ナトリウム　　　　１．４質量％
・リン酸（８５質量％）　　　　５．２質量％
・水酸化ナトリウム　　　　２．０質量％
・シリコン消泡剤　　　　０．０１質量％
・水　　　　８０．８９質量％
【０２５９】
５．平版印刷版の評価
上記各平版印刷版原版から得られた各平版印刷版について、以下の評価を行った。実施例１−１〜１−１３および比較例１−１〜１−１３についての結果を第２表に示す。なお、第２表においては、同一の支持体について、画像記録層１および２のそれぞれを有する平版印刷版を用いて、総合的に評価を行った。
【０２６０】
（１）耐刷性
小森コーポレーション社製のリスロン印刷機で、大日本インキ化学工業社製のＤＩＣ−ＧＥＯＳ（Ｎ）墨のインキを用いて印刷し、ベタ画像の濃度が薄くなり始めたと目視で認められた時点の印刷枚数により、耐刷性を評価した。
評価は印刷枚数の相対評価により行い、多い方から順に、「優良」、「良好」、「やや悪」、「悪」とした。
【０２６１】
（２）耐通常汚れ性
三菱ダイヤ型Ｆ２印刷機（三菱重工業社製）で、ＤＩＣ−ＧＥＯＳ（ｓ）紅のインキを用いて印刷し、１万枚印刷した後におけるブランケットの汚れを目視で観察し、耐通常汚れ性を評価した。
汚れのない方から順に、「優良」、「良好」、「やや悪」、「悪」とした。
【０２６２】
（３）耐苛酷インキ汚れ性
Ｃｌイオンを添加した湿し水を用いて印刷を行い、印刷機上放置を１回以上行なった際に生じる非画像部の汚れを目視観察して、耐苛酷インキ汚れ性を評価した。
汚れの少ない方から順に、「良好」、「やや悪」、「悪」とした。
【０２６３】
（４）耐ポツ状汚れ性
平版印刷版の非画像部を光学顕微鏡で倍率１００倍で観察し、１ｍｍ四方の面積におけるポツ状残膜の有無を調べた。また、上記（１）耐刷性と同様の印刷を行い、５００枚印刷した時点での印刷物の非画像部に生じる小さい点状の汚れ（ポツ状汚れ）を観察した。これらから、耐ポツ状汚れ性を評価した。
ポツ状残膜が観察されず、ポツ状汚れがないものおよび実用上問題のないものを「良好」、ポツ状残膜が観察され、ポツ状汚れが実用上問題となるものを「悪」と評価した。
【０２６４】
（５）水幅
湿し水の量を段階的に減らして、上記（１）耐刷性と同様の印刷を行い、面積率５０％の網点部に関し、網点と網点との間にインキが付着し始めたときの湿し水の量で水幅を評価した。
インキが付着し始めたときの湿し水の量が少ない方から順に、「良好」、「やや悪」、「悪」とした。
【０２６５】
（６）インキの絡みにくさ
小森コーポレーション社製のＳＯＲ−Ｍ印刷機で、大日本インキ化学工業社製のＤＩＣ−ＧＥＯＳ（Ｈ）墨を用いて、湿し水を少なくして印刷を行い、網点部におけるインキの絡みにくさを評価した。
インキの絡みが認められない順に、「良好」、「やや悪」、「悪」とした。
【０２６６】
【表３】

【０２６７】
【表４】

【０２６８】
実施例１−１〜１−１３および２−１〜２−１３の平版印刷版用支持体は、中心線平均粗さＲ_ａが０．３５μｍ以上であり最大高さＲ_ｍａｘが８．０μｍ以下の表面を有しており、ピットが均一で、平版印刷版としたときの耐刷性、耐汚れ性（耐通常汚れ性、耐苛酷インキ汚れ性、水幅およびインキの絡みにくさ）および露光安定性（耐ポツ状汚れ性）が高い水準でバランスよく実現されていた。中でも、実施例１−１〜１−１３の平版印刷版用支持体は、耐刷性に優れており、特に、実施例１−１０〜１−１３の平版印刷版用支持体は、耐刷性および耐通常汚れ性に極めて優れていた。
【０２６９】
これに対して、比較例１−１〜１−１３の平版印刷版用支持体は、アルミニウム板の物性を満足していないため、耐刷性に劣っていた。比較例２−１〜２−１３および３−１〜３−１３の平版印刷版用支持体は、すべて中心線平均粗さＲ_ａが０．３４μｍ以下であり、水幅およびインキの絡みにくさに劣っていた。比較例４−１〜４−１３および５−１〜５−１３は、すべて中心線平均粗さＲ_ａが０．３５μｍ以上であったが、最大高さＲ_ｍａｘが８．０μｍを超えており、耐ポツ状汚れ性に劣っていた。
【０２７０】
【発明の効果】
本発明の平版印刷版用支持体を用いた本発明の平版印刷版原版は、平版印刷版としたときの耐刷性、耐汚れ性および露光安定性を高い水準でバランスよく実現することができる。
また、本発明の平版印刷版用支持体の製造方法は、上記本発明の平版印刷版用支持体を製造する方法として好適である。
【図面の簡単な説明】
【図１】実施例において電気化学的粗面化処理（ｄ）および（ｇ）で印加した台形波電流の波形を示す波形図である。
【図２】実施例において電気化学的粗面化処理（ｄ）および（ｇ）で使用した電解槽の構成の概略を示す断面図である。
【図３】従来の平版印刷版原版の支持体と画像記録層との界面の一例を模式的に示す断面図である。（ａ）は露光前、（ｂ）は露光中、（ｃ）は露光後を示す。
【図４】従来の平版印刷版原版の支持体と画像記録層との界面の他の一例を模式的に示す断面図である。（ａ）は露光前、（ｂ）は露光中、（ｃ）は露光後を示す。
【符号の説明】
１０　平版印刷版原版
１２　平版印刷版用支持体
１４　画像記録層
４０　電解槽
４２　電解槽本体
４２Ａ　開口部
４４　送りローラ
４６Ａ、４６Ｂ　主極
４８Ａ、４８Ｂ　給液ノズル
５０Ａ　下流側案内ローラ
５０Ｂ　上流側案内ローラ
５２　溢流槽
５４　補助電解槽
５４Ａ　底面
５６　補助電極
１０４　ラジアル型電解槽
ＡＣ　交流電源
Ｐ　　ピット
Ｐ’　不均一なピット
Ｔｈ１、Ｔｈ２　　サイリスタ
Ｗ　アルミニウムウェブ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a support for a lithographic printing plate, and more particularly to a support for a lithographic printing plate that can achieve excellent printing durability, stain resistance, and exposure stability in a high level in a balanced manner when used as a lithographic printing plate. .
[0002]
[Prior art]
Photosensitive lithographic printing plate precursors using an aluminum plate as a support are widely used for offset printing.
As a method for producing the lithographic printing plate precursor, generally, a surface of a sheet-shaped or coil-shaped aluminum plate is subjected to roughening treatment and anodizing treatment to obtain a lithographic printing plate support, and then the support. There is known a method in which a photosensitive solution is applied and dried to form an image recording layer and cut to a desired size as necessary. This lithographic printing plate precursor is subjected to a development process after image printing to form a lithographic printing plate.
In this method, in order to improve the adhesion between the image recording layer and the support, a surface roughening treatment performed electrochemically in an acidic solution is effective. It is also effective to apply the above.
The process of trimming to a desired size is usually carried out continuously after applying and drying the photosensitive solution. However, when using a coiled aluminum plate, it is once wound into a coil after applying and drying the photosensitive solution. It can be stored and trimmed as needed.
A plurality of lithographic printing plate precursors cut to a predetermined size are packed and packed, and a user performs image printing, development processing, end bending processing for attachment to a printing machine, and the like.
[0003]
The image printing process is performed using a laser exposure apparatus in a direct-drawing lithographic printing plate precursor that has recently been put into practical use. Some direct-drawing lithographic printing plate precursors can be printed by simply attaching the lithographic printing plate precursor to the plate cylinder of the printing press and performing image printing on the printing press. An image printing process, development process, and the like that can be printed before being installed in a machine are known.
[0004]
In these planographic printing plate precursors, if the pits formed on the surface of the aluminum plate by the roughening treatment are non-uniform and there are some large and deep pits, the image recording layer provided on the aluminum plate will enter more of them. It will end up. For this reason, the layer thickness (film thickness) of the image recording layer also becomes non-uniform, and the film thickness is large at large and deep pits, resulting in insufficient exposure or non-uniform light scattering due to halation. That is, a lithographic printing plate precursor having poor exposure stability is obtained.
[0005]
FIG. 3 is a schematic diagram showing a cross-sectional structure of a conventional positive type lithographic printing plate precursor 10 in the case where the roughening by the roughening treatment is uneven (pit diameter and depth are not uniform). 4). The lithographic printing plate precursor 10 is a laminate having a lithographic printing plate support 12 on which pits (unevenness) P are formed and an image recording layer 14 laminated thereon. When the depth of the pit P in the exposure direction is non-uniform (FIG. 3A), for example, when a deep pit P ′ portion is exposed, halation (non-uniform scattering of light) occurs (FIG. 3 ( b)), the physical properties of the non-exposed portion are changed in the same manner as the exposed portion, and are removed by development processing (FIG. 3C). As a result, “fogging” may occur in the printed image. Further, when the development process is not performed and the image recording layer is not removed, the unexposed portion is similarly adversely affected. These adverse effects on the non-exposed portion may occur in a lithographic printing plate precursor having any type of image recording layer, that is, a photon mode image recording layer (photosensitive layer) and a thermal mode image recording layer (thermosensitive layer). .
[0006]
Further, as shown in FIG. 4, when a wide area including the pit P and the pit P ′ is exposed, the exposure is insufficient at the bottom of the pit P ′ farther from the light source (FIG. 4B). A non-exposed part may occur in the part (FIG. 4C). As a result, although the photosensitive layer removal portion originally becomes a non-image, it partially shows the characteristics of the image portion and tends to be a starting point of smearing during printing. That is, exposure variation may occur and exposure stability may be poor.
In particular, in the case of a lithographic printing plate precursor in the thermal mode, the laser beam is once converted into thermal energy, and physical properties are changed by the thermal energy to burn the image, so the distance from the surface layer, that is, the film thickness of the image recording layer. The effect of heat energy on heat conduction increases, and heat energy is not sufficiently conducted at the bottom of large and deep pits, and image printing may not be performed sufficiently.
[0007]
In addition, the aluminum plate used for the support itself has a very high thermal conductivity, so even if the heat energy reaches the bottom of the pit, the support is easily deprived of the heat energy, causing changes in physical properties. There is a tendency to run out of energy. In order to suppress such a thermal diffusion phenomenon to the support, a technique of providing a heat insulating layer between the image recording layer and the support is proposed in Japanese Patent Application Laid-Open No. 11-65105. It is not enough to cope with the partial thermal energy shortage caused by.
[0008]
Furthermore, since the image recording layer used in the direct-drawing lithographic printing plate is difficult to ensure adhesion with the support as compared with the image recording layer used in the conventional lithographic printing plate precursor, the direct-drawing lithographic plate It is necessary to make the support used for the printing plate a support excellent in adhesion to the image recording layer as compared with the support used for the conventional lithographic printing plate precursor.
However, the support roughened by the roughening treatment including the conventional electrochemical roughening treatment can sufficiently obtain the adhesion level required for the support used in the direct drawing type lithographic printing plate. Therefore, there is a problem that sufficient printing durability cannot be obtained when a planographic printing plate is used.
[0009]
Specific examples of the technology having the above problems include the following.
For example, in US Pat. No. 4,555,475, an aluminum plate surface having an anodized film is silicate-treated to form an aluminosilicate, and hydrophobicity is imparted by irradiating a laser such as YAG, A method for increasing the oil sensitivity by attaching an epoxy resin or the like to the portion is described. In this method, in addition to inferior exposure stability of the lithographic printing plate, there is a problem in that the oil-sensitive component is attached later, so that adhesion is insufficient and high printing durability cannot be obtained.
In EP 164,128, an aluminum plate is subjected to surface treatment, anodizing treatment and silicate treatment, and then a diazo resin and carbon black are applied thereon to form a light-sensitive material. A technique for lacquering after exposure to produce a plate for newspaper printing is described. In this technique, in addition to inferior exposure stability, there is a problem that high printing durability cannot be obtained because the adhesion between the lacquer in the image area and the diazo resin is insufficient.
[0010]
Japanese Patent Laid-Open No. 7-306528 discloses a mechanical surface roughening treatment, an alkali etching treatment, a neutralization washing treatment, and a 1% nitric acid solution using an aqueous suspension of nylon brush and pamiston in order on an aluminum plate. A substrate obtained by performing electrochemical surface roughening treatment, desmut treatment, anodization treatment, and sodium silicate solution treatment, a photothermal conversion substance and a diazonium compound having two or more diazionio groups in the molecule. A lithographic printing plate provided with an image recording layer is described.
In Japanese Patent Laid-Open No. 9-236911, a mechanical surface roughening treatment, an alkali etching treatment, a water washing treatment, a neutralization washing treatment, an electrochemical rough surface in a 1% nitric acid solution are sequentially applied to an aluminum plate of material 1S. Substrates obtained by applying a treatment containing a silicone compound having a functional group capable of causing an addition reaction due to radicals, after performing a chemical treatment, desmut treatment, anodizing treatment, sodium silicate solution treatment, water washing and drying treatment And a photopolymerizable image recording layer comprising a photopolymerizable composition comprising a compound having at least one ethylenically unsaturated bond polymerizable by active light, a linear organic polymer, and a photopolymerization initiator. And a lithographic printing plate in which an oxygen barrier layer is sequentially provided.
[0011]
In JP-A-9-114043, an aluminum plate is sequentially subjected to mechanical surface roughening treatment, alkali etching treatment, neutralization washing treatment, and electrochemical in 1% nitric acid solution containing 0.5% aluminum nitrate. A lithographic printing plate is described in which an image recording layer containing silver halide is provided on a substrate obtained by roughening treatment, alkali etching treatment, desmutting treatment, and anodizing treatment.
In this publication, an aluminum plate (material 1050) is sequentially subjected to a degreasing treatment for washing with trichlorethylene, a mechanical surface roughening treatment, a water washing treatment, an alkali etching treatment, a water washing treatment, a desmut treatment, and an anodizing treatment. A lithographic printing in which an image-recording layer comprising a polymer compound having a functional group that generates a sulfonic acid by the action of an acid in its side chain and a photoacid generator, selected from predetermined functional groups, is provided on the obtained substrate The edition is listed.
The publication further describes, in order, an aluminum plate (material 1050), a degreasing treatment for washing with trichlorethylene, a mechanical roughening treatment, a water washing treatment, an alkali etching treatment, a water washing treatment, a desmut treatment, an anodizing treatment, and water. Washing and drying treatment, and then applying the substrate undercoating and drying to the substrate or aluminum plate, in order, mechanical surface roughening treatment, water washing treatment, alkali etching treatment, water washing treatment, desmut treatment, water washing The substrate obtained by electrochemical surface roughening treatment, desmutting treatment and anodizing treatment in 1% nitric acid solution absorbs the binder and light and generates heat and is thermally decomposable. A lithographic printing plate is described which is provided with an image recording layer containing a substance which substantially and does not degrade the solubility of the binder.
In these planographic printing plates, the pit shape generated by the electrochemical surface roughening treatment is easily affected by the aluminum plate and may not be uniform, and the exposure stability may be inferior. In addition, for the same reason, the adhesion between the image recording layer and the substrate is insufficient, and an excellent printing durability may not be obtained.
[0012]
Japanese Patent Application Laid-Open No. 11-167204 describes a technique for specifying a pit shape on a roughened support surface. In this technology, the pit shape generated by the electrochemical surface roughening treatment is easily affected by the aluminum plate and does not become uniform. Therefore, the exposure stability is inferior, and the adhesiveness between the image recording layer and the substrate is insufficient and the printing durability is reduced. There is also a problem that it is inferior.
Japanese Patent Application Laid-Open No. 11-65105 discloses a technique of providing a heat insulating layer on a substrate obtained by subjecting an aluminum plate of 1050 material to a tempered H16 by electrochemical surface roughening and anodizing with a specified amount of film, and Japanese Patent Application Laid-Open No. 11-139023 discloses a technique for providing a heat insulating layer with a specified coating amount obtained by subjecting a 1050 aluminum plate to an electrochemical roughening treatment and an anodizing treatment with a specified coating amount. The technology about is described. In these techniques, the pit shape generated by the electrochemical surface roughening treatment is easily affected by the aluminum plate and is not uniform, so that the exposure stability of the lithographic printing plate is poor. For the same reason, there is a problem that the adhesion between the image recording layer and the substrate or the substrate and the heat insulating layer is insufficient and the printing durability is inferior.
[0013]
Further, a lithographic printing plate in which an electrophotographic photosensitive member comprising a photoconductive layer is provided as an image recording layer on an aluminum plate, a lithographic printing plate in which a polarity conversion type image recording layer is provided, and a photothermal conversion material having a hydrophilic surface by abrasion. A planographic printing plate provided with an image recording layer that switches between hydrophilicity and lipophilicity is known, but in order to ensure the adhesion between the image recording layer and the substrate, the pit shape generated by the roughening process is similarly It must be uniform.
In this way, the lithographic printing has a uniform pit shape formed on the surface of the aluminum plate, excellent printing durability and stain resistance when used as a lithographic printing plate, and prevents exposure variation and excellent exposure stability. No plate support is provided.
[0014]
[Problems to be solved by the invention]
The present invention relates to a lithographic printing plate precursor that can achieve excellent printing durability, stain resistance, and exposure stability in a high level in a well-balanced manner when used as a lithographic printing plate, and a lithographic printing plate that is suitably used for the lithographic printing plate The object is to provide a support.
Another object of the present invention is to provide a method for producing the lithographic printing plate support.
[0015]
[Means for Solving the Problems]
As a result of intensive studies, the inventor uses an aluminum plate that specifies the metal elements contained in the aluminum plate, the content thereof, the physical properties of intermetallic compounds including these, and the content of simple substance Si in the aluminum plate, Centerline average roughness R after roughening treatment_aAnd maximum height R_maxWhen a lithographic printing plate precursor using a lithographic printing plate support having a surface in a specific range is a lithographic printing plate, it has excellent printing durability, stain resistance and exposure stability at a high level. The present invention has been completed by finding out that it can be realized in a well-balanced manner.
According to the present invention, since the uniformity of the shape of the pits generated by the electrochemical surface roughening treatment can be improved, the printing durability and stain resistance are excellent. Further, since the volume of the image recording layer entering the uniform pit (film thickness of the image recording layer provided on the aluminum plate) can be made uniform, the exposure stability is excellent.
In the present invention, “stain resistance” can be evaluated by, for example, normal stain resistance, severe ink stain resistance, water width and ink entanglement.
[0016]
That is, the present invention provides the following (I) to (IV).
[0017]
(I) Centerline average roughness R obtained by subjecting an aluminum plate to surface roughening and anodizing_aIs 0.35μm or more, maximum height R_maxA lithographic printing plate support having a surface of which is 8.0 μm or less,
The aluminum plate is
Fe content is 0.15-0.5 mass%, Si content is 0.03-0.15 mass%, Cu content is 0.0001-0.030 mass%, Ti content is 0.0010. 0.04 mass%, Pb content is 0.0001-0.0030 mass%, Ni content is 0.0002-0.005 mass%, the balance consists of Al and inevitable impurities,
About the intermetallic compound which exists in the surface of the said aluminum plate and consists of 2 or more types of these metallic elements, the intermetallic compound whose circle equivalent diameter is 1 micrometer or more is 7000 piece / mm.²And the ratio of the intermetallic compound having an equivalent circle diameter of 1 to 10 μm is 85% or more,
A support for a lithographic printing plate, which is an aluminum plate in which elemental Si present in the aluminum plate is 0.010% by mass or less.
[0018]
(II) The lithographic printing plate support according to (I), wherein the aluminum plate further contains Cr and / or Zr, and the content of at least one is 0.0001 to 0.005% by mass. .
[0019]
(III) The aluminum plate further contains Ba and / or Co, and the content of at least one is 0.00001 to 0.0010% by mass, according to any one of (I) and (II) above Lithographic printing plate support.
[0020]
(IV) A lithographic printing plate precursor comprising an image recording layer provided on the lithographic printing plate support according to any one of (I) to (III) above.
[0021]
In addition, the inventor performs an electrochemical surface roughening treatment on the aluminum plate under specific conditions, preferably further specifies the amount of aluminum dissolved in the alkali etching treatment after the electrochemical surface roughening treatment. Thus, it has been found that the lithographic printing plate support of the above (I) to (III) can be easily produced.
Furthermore, the present inventor can easily produce the lithographic printing plate support of the above (I) to (III) by specifying the order of roughening treatment under specific conditions applied to the aluminum plate. It has been found that the uniformity of the pit shape on the surface of the obtained lithographic printing plate support can be further improved, so that the printing durability, stain resistance and exposure stability are particularly excellent.
The present inventor completed the present invention based on these findings.
[0022]
That is, the present invention also provides the following (V) to (VII).
[0023]
(V) A lithographic printing plate for obtaining a lithographic printing plate support according to any one of (I) to (III) above by subjecting the aluminum plate according to (I) to a surface roughening treatment and an anodizing treatment. A method for manufacturing a support for a vehicle,
The roughening treatment is carried out in an electrolytic solution containing nitric acid or hydrochloric acid at a current density of 5 to 70 A / dm.², Amount of electricity in the anode reaction of 10 to 800 C / dm²A method for producing a support for a lithographic printing plate, comprising an electrochemical surface roughening treatment performed under the above conditions.
[0024]
(VI) The surface roughening treatment is performed after the electrochemical surface roughening treatment, and the aluminum dissolution amount is 0.01 to 7 g / m.²The manufacturing method of the support for lithographic printing plates as described in said (V) including the alkali etching process of said.
[0025]
(VII) The roughening treatment is performed in order,
(1) Mechanical roughening treatment with a brush using an abrasive having an average particle diameter of 1 to 60 μm (a),
(2) Amount of aluminum dissolved in a solution containing sodium hydroxide 2 to 15 g / m²Alkaline etching treatment (b),
(3) Desmutting treatment in acidic solution (c),
(4) In an electrolytic solution containing nitric acid having a concentration of 0.2 to 2% by mass, a current density of 5 to 70 A / dm using an AC waveform.², Amount of electricity in the anode reaction of 10 to 800 C / dm²Electrochemical graining treatment (d) performed under the conditions of
(5) Amount of aluminum dissolved in a solution containing sodium hydroxide 0.01 to 7 g / m²Alkaline etching treatment (e),
(6) Desmutting treatment in acidic solution (f),
(7) In an electrolytic solution containing hydrochloric acid having a concentration of 0.1 to 2% by mass, a current density of 5 to 70 A / dm using an AC waveform.², Amount of electricity in the anode reaction of 10 to 800 C / dm²Electrochemical roughening treatment (g) under the conditions of
(8) Dissolution amount of aluminum in a solution containing sodium hydroxide 0.001 to 6 g / m²Alkali etching treatment (h), and
(9) Desmutting treatment in acidic solution (i)
Including
The anodizing treatment is performed in an acidic solution containing sulfuric acid and aluminum ions having a concentration of 5% by mass or more, and an oxide film amount of 1 to 5 g / m.²The method for producing a lithographic printing plate support according to the above (VI), which is anodizing treatment (j).
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[Support for lithographic printing plate]
<Surface shape of lithographic printing plate support>
The lithographic printing plate support of the present invention has a center line average roughness R_aIs 0.35μm or more, maximum height R_maxOne of the features is that it has a surface of 8.0 μm or less.
When such a surface is provided, the printing durability, stain resistance, and exposure stability of a lithographic printing plate can be realized with a high level of balance.
[0027]
Centerline average roughness R of the support surface_aRepresents the state of irregularities on the surface of the support.
R_aWhen the thickness is 0.35 μm or more, the printing durability, stain resistance, and exposure stability when a lithographic printing plate is obtained can be realized with a high level of balance.
R_aIs less than 0.35 μm, the pit depth is shallow and the surface area is small, so the printing durability may be inferior.
If the depth of the pits is shallow, the hydrophilicity of the support is lowered, and ink adheres to the non-image area during printing, so that the blanket cylinder may be soiled, and so-called background soiling may occur.
Further, if the depth of the pit is shallow, the water retention of the support becomes low, and if the dampening water is not increased at the time of printing, the shadow portion is clogged. That is, the so-called water width is narrowed.
Furthermore, if deposits such as ink components or paper dust adhere to the surface of the non-image area, the water retention amount decreases rapidly, and the ink moves along the deposit, so the image area (halftone dot) Ink easily moves to the adjacent non-image area. As a result, ink entanglement tends to occur.
[0028]
In the present invention, R_aIs 0.35 μm or more, preferably 0.40 μm or more, and more preferably 0.45 μm or more from the viewpoint that these excellent performances can be realized in a more balanced manner.
R_aIs preferably 0.8 μm or less in that the dirt on the blanket cylinder becomes good.
[0029]
R_maxIs 8.0 μm or less, printing durability, stain resistance and exposure stability when a lithographic printing plate is obtained can be realized in a high level with a good balance.
Maximum height R_maxWhen the thickness exceeds 8.0 μm, the size and depth of the pits are not uniform, and the stain resistance may be inferior. In addition, deep recesses that are considered to cause a decrease in sensitivity are formed. In addition, the stain resistance may be inferior. Maximum height R_maxWhen the thickness exceeds 8.0 μm, the film thickness of the image recording layer provided on the support becomes non-uniform, so that a residual film tends to be formed in deep pits. That is, the pot-like stain resistance (exposure stability) may deteriorate.
R_maxIs not more than 8.0 μm, preferably not more than 7.0 μm, more preferably not more than 6.0 μm in that these excellent performances can be realized in a more balanced manner.
[0030]
In the lithographic printing plate support of the present invention, the surface shape is preferably a structure having a small wave structure having an average opening diameter of 0.01 to 0.2 μm.
The small wave structure having an average opening diameter of 0.01 to 0.2 μm mainly plays a role of improving stain resistance. With such a small wave structure, when dampening water is supplied to the lithographic printing plate at the time of printing, a water film is uniformly formed on the surface of the lithographic printing plate, and the occurrence of stains on the non-image area can be suppressed. When the average opening diameter of the pits having the small wave structure is less than 0.01 μm, a large effect may not be obtained in forming a water film. If the average opening diameter of the pits having the small wave structure exceeds 0.2 μm, the effect of improving the printing durability may be reduced.
[0031]
With this small 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, it is preferable that the average of the ratio of the depth to the opening diameter of the small wave structure is 0.2 or more. 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.
[0032]
In the lithographic printing plate support of the present invention, the surface shape is preferably a structure in which a medium wave structure having an average opening diameter of 0.5 to 5 μm is superimposed.
The medium wave structure having an average opening diameter of 0.5 to 5 μm has a function of holding the image recording layer mainly by an anchor (throwing) effect and imparting printing durability. When the average opening diameter of the pits having a medium wave structure is less than 0.5 μm, the adhesiveness with the image recording layer provided on the upper layer is 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.
[0033]
Further, in the present invention, the surface shape is preferably a structure in which a large wave structure having an average wavelength of 5 to 100 μm is superimposed. When a large wave structure having an average wavelength of 100 μm or less 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 is excellent. The average wavelength of the large wave structure is preferably 10 to 80 μm.
[0034]
In the lithographic printing plate support of the present invention, the center line average roughness R of the surface thereof_a, Maximum height R_maxThe average opening diameter of the small wave structure and the average depth with respect to the opening diameter, the average opening diameter of the medium wave structure, and the average wavelength of the large wave are measured as follows.
[0035]
(1) Centerline average roughness R_a
Two-dimensional roughness measurement is performed with a stylus type roughness meter (for example, sufcom 575, manufactured by Tokyo Seimitsu Co., Ltd.), the average roughness defined in ISO 4287 is measured five times, and the average value is set as the centerline average roughness. .
The conditions for the two-dimensional roughness measurement are shown below.
Cut-off value 0.8mm, tilt correction FLAT-ML, measurement length 3mm, vertical magnification 10000 times, scanning speed 0.3mm / sec, stylus tip diameter 2μm
[0036]
(2) Maximum height R_max
Two-dimensional roughness measurement is performed with a stylus type roughness meter (for example, Surfcom 575, manufactured by Tokyo Seimitsu Co., Ltd.), and the measurement is performed in accordance with JIS B0601-1994.
The conditions for the two-dimensional roughness measurement are shown below.
Cut-off value 0.8 mm, evaluation length 3.0 mm, reference length 3.0 mm, scanning speed 0.3 mm / sec, stylus diameter 2 μm
[0037]
(3) Average aperture diameter of small wave structure
Using a high-resolution scanning electron microscope (SEM), the surface of the support was photographed from directly above at a magnification of 50000 times, and at least 50 small-wave structure pits (small-wave pits) were extracted from the obtained SEM photograph. Is read as the opening diameter, and the average opening diameter is calculated.
[0038]
(4) Average ratio of depth to aperture diameter of small wave structure
The average ratio of the depth to the aperture diameter of the wavelet structure is obtained by photographing the fracture surface of the support at a magnification of 50000 times using a high-resolution SEM, extracting at least 20 wavelet pits from the obtained SEM photograph, And the depth are read to find the ratio and the average value is calculated.
[0039]
(5) Average opening diameter of medium wave structure
The surface of the support was photographed at a magnification of 2000 times from directly above using an electron microscope, and in the obtained electron micrograph, at least 50 pits (medium wave pits) having a medium wave structure in which the periphery of the pits are connected in a ring shape. 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.
[0040]
(6) Average wavelength of large wave structure
Two-dimensional roughness measurement is performed with a stylus type roughness meter, and the average peak interval S defined in ISO 4287 is measured._mIs measured five times, and the average value is taken as the average wavelength.
[0041]
<Aluminum plate (rolled aluminum)>
The lithographic printing plate support of the present invention is produced, for example, by subjecting a web-like aluminum plate made of an aluminum alloy to at least roughening treatment and anodizing treatment.
[0042]
In the present specification, various substrates made of aluminum or an aluminum alloy are generically used as an aluminum plate. Generally, the foreign elements that may be contained in the aluminum plate include, for example, silicon, iron, copper, titanium, gallium, vanadium, zinc, chromium, zirconium, barium, cobalt, etc., and the content of the foreign elements in the alloy Is 10% by mass or less.
In the lithographic printing plate support of the present invention, the Fe content is 0.15 to 0.5% by mass, the Si content is 0.03 to 0.15% by mass, and the Cu content is 0.0001 to 0.00. 030 mass%, Ti content is 0.0010 to 0.04 mass%, Pb content is 0.0001 to 0.0030 mass%, Ni content is 0.0002 to 0.005 mass%, and the balance An aluminum plate made of Al and inevitable impurities is used.
It is one of the preferred embodiments of the present invention that the aluminum plate further contains Cr and / or Zr having a content of at least one of 0.0001 to 0.005 mass%, and the aluminum plate However, it is one of the preferable embodiments of the present invention that Ba and / or Co containing at least one content of 0.00001 to 0.0010% by mass is further contained.
[0043]
The different elements in the aluminum plate greatly depend on the uniformity of the pits generated in the electrochemical surface roughening treatment, and uniform pits are generated by adjusting the type and addition amount of the different elements. Stainability and exposure stability can be achieved with a high level of balance.
In addition, a lithographic printing plate is produced by providing an image recording layer on a lithographic printing plate support to form a lithographic printing plate precursor, and then exposing and developing the image. Depending on the conditions of the developer, It is known that a part of the surface of the non-image area is locally eroded by the developer, and the severe ink stain resistance is lowered. By adding a very small amount of a specific alloy component as in the present invention, the severe ink stain resistance of a lithographic printing plate can be improved regardless of the conditions of the image recording layer and the developer. Here, “severe ink stains” appear on printed paper as a result of the ink becoming more likely to adhere to the non-image area surface of the planographic printing plate when printing is interrupted many times. This refers to dot-like or annular dirt.
[0044]
Fe is an element contained in a new metal in the range of about 0.1 to 0.2% by mass, and the amount dissolved in aluminum is small, and most remains as an intermetallic compound. Fe has the effect of increasing the mechanical strength of the aluminum plate, but if it exceeds 1% by mass, cracking is likely to occur during rolling, and if it exceeds 0.5% by mass, the intermetallic compound increases, and the electrolytic, anode It may affect the formation of oxide film. On the other hand, if the Fe content is less than 0.15% by mass, the mechanical strength cannot be maintained, which may cause problems such as a decrease in yield during rolling.
In this invention, Fe content is 0.15-0.5 mass%, Preferably, it is 0.2-0.3 mass%.
[0045]
Si is an element contained in the new metal also in the range of about 0.02 to 0.1% by mass. Si exists as a solid solution in aluminum, or as an intermetallic compound or a single precipitate. In addition, when heated in the process of producing a lithographic printing plate support, the dissolved Si may precipitate as elemental Si. According to the knowledge of the present inventors, when the elemental Si is excessive, the solid solution Si is likely to precipitate as the elemental Si, and the severe ink stain resistance may be lowered.
Further, the Si content affects the electrochemical surface roughening of the aluminum plate, and if it is less than 0.03% by mass, the pits may be dissolved in the electrochemical surface roughening treatment and a uniform surface structure may not be obtained. .
In this invention, Si content is 0.03-0.15 mass%, Preferably, it is 0.05-0.10 mass%.
[0046]
Cu is an element contained in a lot of scraps of JIS 2000 series and 4000 series materials, and is relatively easily dissolved in Al.
The Cu content greatly affects the electrochemical roughening treatment. In particular, in an electrochemical surface roughening treatment using alternating current in an electrolytic solution containing nitric acid (hereinafter simply referred to as “nitric acid alternating current electrolysis”), if the Cu content is less than 0.0001% by mass, electrolysis is performed. The latitude may become narrower with respect to temperature fluctuations, and if it exceeds 0.030 mass%, the maximum height R_maxIn some cases, non-uniform pits exceeding 8.0 μm may be generated.
Content of Cu is 0.0001-0.030 mass%, Preferably, it is 0.0008-0.02 mass%.
[0047]
Ti is an element that is usually added in an amount of 0.005 to 0.04 mass% as a crystal refining material. JIS 5000 series, 6000 series, and 7000 series scraps contain relatively large amounts of impurity metals. The Ti content affects the degree of crystal refinement (the degree of crystal grain size of the aluminum plate) and the electrochemical surface roughening. If the Ti content is less than 0.0010% by mass, the effect of crystal refining may not be seen. If it exceeds 0.04% by mass, nitric acid AC electrolysis and AC in an electrolyte containing hydrochloric acid are used. In some cases, the electrochemical surface roughening treatment (hereinafter simply referred to as “hydrochloric acid alternating current electrolysis”) generates non-uniform pits.
The Ti content is 0.0010 to 0.04 mass%, preferably 0.01 to 0.03 mass%.
[0048]
The content of Pb affects the electrochemical surface roughening treatment. If the Pb content is less than 0.0001% by mass, an unetched part is likely to occur in hydrochloric acid AC electrolysis, and if it exceeds 0.0030% by mass, pits tend to dissolve particularly in a nitric acid AC electrolysis when the liquid temperature is high. .
Content of Pb is 0.0001-0.030 mass%, Preferably, it is 0.0005-0.010 mass%.
[0049]
The Ni content affects the electrochemical surface roughening treatment. When the Ni content is less than 0.0002% by mass, an unetched portion is likely to occur in hydrochloric acid alternating current electrolysis, and when it is more than 0.005% by weight, pits tend to dissolve particularly in a nitric acid alternating current electrolysis when the liquid temperature is high. .
The content of Ni is 0.0001 to 0.008 mass%, preferably 0.0002 to 0.006 mass%.
[0050]
When Cr and Zr are added in an amount of 0.00005% by mass or more, the effect of improving the resistance to severe ink stains is exhibited. It affects the subsequent surface structure. That is, they affect the microstructure in minimal etching. Cr is a foreign element contained in a small amount in JIS A5000 series, 6000 series, and 7000 series scraps.
Moreover, when there is too much these content, since an effect will be saturated and it will become disadvantageous in cost, it is unpreferable. In this invention, it is preferable to set it as 0.005 mass% or less, and it is more preferable to set it as 0.001 mass% or less from a viewpoint of suppressing cost.
Therefore, these contents are preferably 0.0001 to 0.005% by mass. In addition, when an aluminum plate contains 2 or more types of these elements, it is preferable that at least 1 type satisfy | fills the said range.
[0051]
Ba and Co each have an effect of improving the resistance to severe ink stains when added in an amount of 0.00001% by mass or more, and influences the microstructure in the minimal etching.
Moreover, when there is too much these content, since an effect will be saturated and it will become disadvantageous in cost, it is unpreferable. In this invention, it is preferable to set it as 0.0010 mass% or less, and it is more preferable to set it as 0.0008 mass% or less from a viewpoint of suppressing cost.
Therefore, these contents are preferably 0.00001 to 0.0010% by mass. In addition, when an aluminum plate contains 2 or more types of these elements, it is preferable that at least 1 type satisfy | fills the said range.
[0052]
The balance of the aluminum plate is made of Al and inevitable impurities. Most of the inevitable impurities are contained in the Al ingot. If the inevitable impurities are contained in, for example, a metal having an Al purity of 99.7%, the effects of the present invention are not impaired. For inevitable impurities, see, for example, L.A. F. The amount of impurities described in Mondolfo's “Aluminum Alloys: Structure and properties” (1976) and the like may be contained.
Examples of inevitable impurities contained in the aluminum alloy include magnesium, manganese, lead, nickel, tin, indium, and boron.
[0053]
The aluminum plate used in the present invention has the above composition, and an intermetallic compound having an equivalent circle diameter of 1 μm or more is present in the intermetallic compound consisting of two or more of the above metal elements present on the surface of the aluminum plate. 7000 pieces / mm²And the ratio of the intermetallic compound having an equivalent circle diameter of 1 to 10 μm is 85% or more,
It is an aluminum plate in which the elemental Si present in the aluminum plate is 0.010% by mass or less.
Intermetallic compounds are important as the starting point of pit formation in electrochemical surface roughening treatment, but if pits are too large or there are many pits, they may affect the formation of defects in the anodized film. There is a tendency for dirtiness to deteriorate. According to the knowledge of the present inventor, 7000 intermetallic compounds having a circle equivalent diameter of 1 μm or more existing on the surface are present.²If it is more, defects in the anodized film increase.
[0054]
As an intermetallic compound composed of two or more of the above metal elements, for example, Al₃Fe, Al₆Fe, Ni₃Al, TiAl₃, CuAl₂And an intermetallic compound composed of three elements such as α-AlFeSi and β-AlFeSi.
[0055]
The elements contained in the aluminum plate and the elements added to the molten aluminum are partially melted into the aluminum plate (solid solution) when solidified in the casting process, and the rest are intermetallic compounds, or single crystallized substances or Present as a precipitate. The proportion of the element remaining as an intermetallic compound or a single crystallized product or precipitate is greatly affected by the solidification rate. For example, most of the above elements are solid-solved when rapidly solidified as in the case of roller continuous casting, and when a casting method with a slow solidification rate such as DC casting is employed, It tends to remain as an intermetallic compound or a single crystallized product or precipitate.
[0056]
Thereafter, during the heat treatment process such as soaking and sinter and hot rolling process, many of the above elements are re-dissolved in the aluminum plate or changed to a more stable intermetallic compound. . 1-0. When it becomes an aluminum plate for a lithographic printing plate of about 7 mm, it often exists as an intermetallic compound or a single crystallized product or precipitate on the surface or inside of the aluminum plate.
[0057]
This intermetallic compound acts as a spike between the support for the lithographic printing plate and the image recording layer and exhibits an anchor effect, so that the adhesion between the two is improved, and it is excellent when used as a lithographic printing plate Printing durability. In order to improve adhesion and printing durability, it is particularly preferable that a plurality of types of intermetallic compounds and intermetallic compounds having different forms are mixed.
[0058]
One of the features of the aluminum plate used in the present invention is that 7000 intermetallic compounds having a circle-equivalent diameter of 1 μm or more among the intermetallic compounds existing on the surface of the aluminum plate²It is in the following place. The number is 7000 pieces / mm²Below, 6500 pieces / mm²It is preferable that: When the number of intermetallic compounds per unit area is in the above range, the printing durability and the exposure stability (pot-like stain resistance) are excellent.
[0059]
One of the features of the aluminum plate used in the present invention is that the ratio (existence ratio) of intermetallic compounds having an equivalent circle diameter of 1 to 10 μm with respect to the total amount of intermetallic compounds existing on the surface is 85% or more. It is in.
Intermetallic compounds are important as the starting point of pit formation in electrochemical surface roughening treatment, but if there are variations in the equivalent circle diameter or many equivalent circle diameters exceed 10 μm, electrochemical roughening will occur. In some cases, the pits generated by the surface treatment are non-uniform and the printing durability is poor. In addition, it affects the amount of defects generated in the anodic oxide film, and may have poor ink stain resistance.
The ratio of the intermetallic compound having an equivalent circle diameter of 1 to 10 μm is preferably 90% or more from the viewpoint of excellent resistance to severe ink stains.
[0060]
Furthermore, one of the features of the aluminum plate used in the present invention is that the elemental Si present in the aluminum plate is 0.010% by mass or less.
If the content of the single Si is too large, as described above, the Si that has been dissolved is likely to precipitate as the single Si, and the stain resistance, particularly the severe ink stain resistance, may be lowered.
[0061]
The type of intermetallic compound, the equivalent circle diameter, and the abundance ratio can be controlled by changing the amount of raw materials containing impurities, for example, low-purity scrap materials such as UBC materials and secondary metal. Further, it can be slightly adjusted by appropriately changing the production conditions of the lithographic printing plate support. For example, the treatment temperature in the acid treatment step of the desmut treatment step, the acid concentration of sulfuric acid, etc. may be lowered to reduce the ability to remove the intermetallic compound by the acid, and may be appropriately changed within a predetermined range. When it is desired to reduce the abundance ratio, a method of appropriately removing by chemical etching using hydrochloric acid can be used.
[0062]
The type of intermetallic compound and the content thereof are observed on the roughened surface with an SEM (scanning electron microscope) or the like, for example, at 5 locations (n = 5) in a range of 60 μm × 50 μm, Count intermetallic compounds, 1mm²It can be easily calculated by converting to a per unit. A similar method can be used for measuring the diameter.
[0063]
Moreover, it can also calculate by the following method, for example, using EPMA (Electron Probe Microanalyzer).
In the measurement of the equivalent circle diameter of the intermetallic compound and the abundance thereof, it is preferable to wipe off the oil on the surface of the aluminum plate with acetone to obtain a measurement sample.
Using EPMA, acceleration voltage 20.0 kV, irradiation current 9.5 × 10^-9A composition image using a highly sensitive backscattered electron detector under the condition A is taken at a magnification of 500 times to obtain an instant photograph.
Next, the reflected electrophotography (instant photograph) is converted into a bmf (bitmap file) format by image processing software, and this file is read into the image analysis software for image analysis. The image is subjected to static binarization processing, the portion corresponding to the white intermetallic compound is counted, and a circle equivalent diameter (equivalent circle diameter) is designated as a feature amount to obtain a circle equivalent diameter distribution.
[0064]
The content of simple substance Si in the aluminum plate can be measured, for example, by the following method.
First, it is put into hydrochloric acid to decompose the aluminum plate sample. When most of the sample is decomposed, add hydrogen peroxide solution, adjust the liquid volume and boil to completely decompose the sample.
After cooling in running water, filter the insoluble residue, thoroughly wash the beaker, filter tube, filter and residue with distilled water, wrap the filter and residue with one sheet of 5 types A filter paper, and heat in a platinum crucible. Ash.
After igniting at about 1000 ° C., it is cooled to room temperature in a silica gel desiccator and the mass is measured. This treatment is repeated until a constant weight is reached to obtain the mass before the hydrofluoric acid treatment.
After reaching a constant weight, add a few drops of sulfuric acid to moisten the oxide in the crucible, add hydrofluoric acid, heat to dryness, and ignite at about 1000 ° C. Cool to room temperature in a silica gel desiccator and measure mass. This hydrofluoric acid treatment is repeated until a constant weight is reached, and the mass after the hydrofluoric acid treatment is obtained.
This total weight loss is silicon dioxide (SiO₂) Amount.
On the other hand, without using an aluminum plate sample, a blank test using the same amount of reagent as described above (blank) was performed, and as a blank test value, silicon dioxide (SiO 2₂) Find the amount.
The content (mass%) of elemental Si in the aluminum plate is calculated by the following formula [1].
[0065]
Si content (mass%) = (W₁-W₂-W₃) X (0.4674 / W₀) X 100 [1]
[0066]
Where W₀Is the sample weighed (g), W₁Is the mass before hydrofluoric acid treatment (g), W₂Is the mass after hydrofluoric acid treatment (g), W₃Is a blank test value (g).
[0067]
The aluminum plate used in the present invention omits the DC casting method, the continuous casting method, the DC casting method from which either or both of the intermediate annealing treatment and the brazing heat treatment are omitted, and the intermediate casting treatment from the continuous casting method. It can be manufactured by any of the manufacturing methods. Moreover, what was cast by said normal method may be appropriately subjected to a rolling treatment or a heat treatment to have a thickness of, for example, 0.1 to 0.7 mm, and a flatness correction treatment may be performed as necessary. . 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.
[0068]
The aluminum plate finished to a predetermined thickness, for example, 0.1 to 0.7 mm, may be further improved in flatness by a correction device such as a roller leveler or a tension leveler.
[0069]
<Roughening treatment>
The lithographic printing plate support of the present invention is a lithographic printing plate support having the above surface, which is obtained by subjecting the aluminum plate to a surface roughening treatment and an anodizing treatment.
In the surface roughening treatment, the surface roughening treatment is carried out in an electrolytic solution containing nitric acid or hydrochloric acid at a current density of 5 to 70 A / dm.², Amount of electricity in the anode reaction of 10 to 800 C / dm²It is preferable to include an electrochemical surface roughening treatment performed under the following conditions. Further, after the electrochemical surface roughening treatment, the aluminum dissolution amount is 0.01 to 7 g / m.²More preferably, an alkaline etching treatment is included.
[0070]
The roughening process is
(1) Mechanical roughening treatment with a brush using an abrasive having an average particle diameter of 1 to 60 μm (a),
(2) Amount of aluminum dissolved in a solution containing sodium hydroxide 2 to 15 g / m²Alkaline etching treatment (b),
(3) Desmutting treatment in acidic solution (c),
(4) In an electrolytic solution containing nitric acid having a concentration of 0.2 to 2% by mass, a current density of 5 to 70 A / dm using an AC waveform.², Amount of electricity in the anode reaction of 10 to 800 C / dm²Electrochemical graining treatment (d) performed under the conditions of
(5) Amount of aluminum dissolved in a solution containing sodium hydroxide 0.01 to 7 g / m²Alkaline etching treatment (e),
(6) Desmutting treatment in acidic solution (f),
(7) In an electrolytic solution containing hydrochloric acid having a concentration of 0.1 to 2% by mass, a current density of 5 to 70 A / dm using an AC waveform.², Amount of electricity in the anode reaction of 10 to 800 C / dm²Electrochemical roughening treatment (g) under the conditions of
(8) Dissolution amount of aluminum in a solution containing sodium hydroxide 0.001 to 6 g / m²Alkali etching treatment (h), and
(9) Desmutting treatment in acidic solution (i)
It is particularly preferred that
[0071]
By performing such roughening treatment, the specific R described above_a, R_maxThe lithographic printing plate support of the present invention having an intermetallic compound and simple substance Si can be easily produced. Further, by applying a particularly preferable roughening treatment, a triple wave structure including large waves, medium waves and small waves having the above-mentioned opening diameter can be formed, and the uniformity of the pit shape can be further improved. The printing durability, stain resistance and exposure stability are particularly excellent when a printing plate is used.
[0072]
Hereinafter, although the roughening process which has each process of (a)-(i) mentioned above is demonstrated, in this invention, a roughening process is not limited to this.
[0073]
<Mechanical roughening treatment (a)>
In the mechanical surface roughening treatment (a), at least one surface of the aluminum plate is subjected to brush graining which is roughened by rubbing with a roller brush.
[0074]
In the mechanical roughening treatment, the centerline average roughness of the roughened surface after the treatment is 0. It is preferable to carry out so that it may become 3-0.8 micrometer. More preferably 0. 35-0. 7 μm. Within this range, the centerline average roughness R of the obtained lithographic printing plate support is obtained._aIs easy to adjust.
[0075]
Prior to performing brush graining, if necessary, a degreasing treatment for removing the rolling oil adhering to the surface of the aluminum plate can be performed. As the degreasing treatment, for example, a treatment with a surfactant, a treatment with an organic solvent, a treatment with an alkaline aqueous solution, or the like can be performed. However, when there is little adhesion of rolling oil, the said degreasing process can be abbreviate | omitted.
[0076]
Subsequently, brush graining is performed using one or two or more types of roller brushes having different bristle diameters while supplying the abrasive slurry to the surface of the aluminum plate.
As described in detail in Japanese Patent Application Laid-Open No. 6-135175 and Japanese Patent Publication No. 50-40047, brush graining has a roller-shaped brush disposed on the upper side of an aluminum plate to be roughened. The roller can be rotated while the abrasive slurry is supplied between the roller brush and the aluminum plate while the support roller is disposed at a constant speed and the aluminum plate is conveyed at a constant speed. .
[0077]
Two supporting rollers can be arranged for each roller brush. The pair of support rollers positioned below the roller brush is preferably arranged such that the shortest distance between the outer surfaces is smaller than the outer diameter of the roller brush.
At the time of the brush graining, it is preferable that the aluminum plate is pressed by the roller-shaped brush so as to be pressed between the two support rollers.
[0078]
The roller-like brush used in the present invention is a brush-like brush formed from nylon, polypropylene, animal hair, steel wire, or the like, and is planted on the entire side surface of the cylindrical drum with uniform hair length and flocking distribution. A plurality of small holes are formed on the entire surface of the surface, and a brush bristle bundle, which is a bundle of brush bristles, is implanted in each of the small holes, and a channel roller type is preferably used.
[0079]
The brush hair diameter is 0. 05-0. 8 mm is preferable, and 0. 15-0. More preferably, it is 5 mm. The cross-sectional shape of the brush hair is preferably circular. Hair diameter is 0. If it is 05 mm or more, a lithographic printing plate excellent in stain resistance at the shadow portion can be obtained. If it is 8 mm or less, a lithographic printing plate in which blanket contamination is less likely to be obtained.
[0080]
The length of the brush hair after flocking is preferably 10 to 200 mm, and more preferably 25 to 100 mm. The hair density when planted in a roller brush is 1cm²The number is preferably 30 to 1000, more preferably 50 to 300.
Among the materials described above, nylon is preferable among the materials described above, and nylon 6, nylon 6, 6, nylon 6, 10 and the like are more preferable. Tensile strength, wear resistance, dimensional stability due to water absorption, bending strength Nylon 6 · 10 is particularly preferable from the viewpoint of excellent heat resistance, recoverability, and the like.
[0081]
The number of roller-shaped brushes is preferably 1 to 10, more preferably 1 to 6, and particularly preferably 3 to 4. As described in JP-A-6-135175, two or more roller brushes having different bristle diameters may be combined.
The rotation speed of the roller brush is preferably 100 to 500 rpm. The roller brush is preferably rotated (forward-rotated) in the same direction as the aluminum plate transport direction. However, when there are a large number of roller brushes, a part of the roller brushes are aligned with the aluminum plate transport direction. You may rotate (reverse) in the reverse direction. When three roller brushes are used, the roller brush located on the most upstream side in the transport direction of the aluminum plate is rotated forward, the central roller brush is reversed, and the transport direction of the aluminum plate is reversed. It is particularly preferable that the roller brush located on the most downstream side is rotated forward. When four roller-shaped brushes are used, the rotation direction of the four roller-shaped brushes is from the upstream side (hereinafter simply referred to as “upstream side”) with respect to the aluminum plate conveyance direction to the aluminum plate conveyance direction. Therefore, it is preferable to forward, reverse, forward, and forward toward the downstream side (hereinafter simply referred to as “downstream side”).
[0082]
In addition, the roller brush is, for example, 0. 0 along the direction perpendicular to the conveying direction of the aluminum plate. By oscillating at a cycle of 0001 to 1 Hz and an amplitude of 10 to 200 mm, a lithographic printing plate support having a surface free from processing unevenness can be obtained.
The pushing amount of the roller brush is preferably the power consumption of the motor. It is preferable to manage based on the load of the motor that rotates the roller brush so that it becomes 0 to 15 kW, more preferably 2 to 10 kW.
[0083]
In the above brush graining, after roughening with a roller-like brush with thick brush bristles, processing with a roller-like brush with thin brush bristles causes the shadow to collapse even when there is little dampening water. Therefore, a lithographic printing plate having a wide water width, hardly causing scumming, no adhesion deterioration with the image recording layer, and having hydrophilicity, water retention and adhesion is preferable.
[0084]
As an abrasive slurry used in the present invention, for example, an abrasive such as silica sand, aluminum hydroxide, alumina powder, volcanic ash, pumice powder, carborundum, and gold sand is used. 05-1. The one dispersed in water within a range of 3 is preferable. The average particle diameter of the abrasive is 1 to 60 μm, preferably 5 to 55 μm, and particularly preferably 15 to 50 μm. In this range, the center line average roughness R_aAnd maximum height R_maxCan be easily adjusted within the above range, so that when it is a lithographic printing plate, printing durability, stain resistance and exposure stability can be realized at a high level in a well-balanced manner. Here, the average particle diameter is a particle diameter at which the cumulative ratio becomes 50% when the cumulative frequency of the ratio of the particles of each diameter is taken with respect to the volume of the entire abrasive contained in the slurry liquid.
[0085]
The average particle size of the abrasive is, for example, passing the abrasive slurry through a classification means such as a cyclone, and classifying the abrasive in the abrasive slurry into one having a large particle size and one having a small particle size. It can be controlled by recovering the abrasive slurry mainly containing the larger abrasive and discarding the abrasive slurry mainly containing the smaller abrasive.
[0086]
The abrasive concentration in the abrasive slurry is managed based on the specific gravity of the abrasive slurry. The specific gravity is preferably controlled so that the fluctuation range is within ± 10%.
The specific gravity of the abrasive slurry is determined by, for example, measuring the specific gravity of the abrasive slurry intermittently or continuously, and when the specific gravity is smaller than the above range, replenish the abrasive slurry with fresh abrasive. When the specific gravity is larger than the above range, it can be controlled by replenishing the abrasive slurry with water to lower the specific gravity.
[0087]
In brush graining, in order to obtain the centerline average roughness (0.3 to 0.8 μm) after the brush grain, a combination of the pushing amount, the rotation speed, and the rotation direction of the roller brush, the roller brush Of each roller-shaped brush, brush bristle density, tension applied to the aluminum plate, type of abrasive blended with the abrasive slurry, average particle size, particle size distribution, and the abrasive slurry on the aluminum plate It is preferable to select the flow rate, direction, angle, etc. to be sprayed.
[0088]
<Alkali etching treatment (b)>
By performing an alkali etching treatment (b) after the mechanical roughening treatment (a), the abrasive or aluminum debris that has digged into the surface of the aluminum plate is removed, and the electrochemical roughening applied thereafter. The surface treatment (d) can be performed more uniformly and effectively.
[0089]
In the alkali etching process, the aluminum plate is brought into contact with an alkaline solution.
Examples of the method of bringing the aluminum plate into contact with the alkaline solution include, for example, a method of continuously passing the aluminum plate in a tank containing the alkaline solution, a method of immersing the aluminum plate in a tank containing the alkaline solution, and the alkaline solution The method of spraying the surface of an aluminum plate etc. is mentioned.
[0090]
The dissolution amount of the aluminum plate in the alkali etching treatment, in other words, the etching amount is 2 to 15 g / m.²3-10 g / m²Is preferred.
Within this range, steep portions of pits generated by the mechanical surface roughening treatment can be efficiently dissolved while maintaining the water retention amount.
[0091]
The alkaline solution contains sodium hydroxide as the main alkaline component. Examples of other alkali components that may be contained in the alkaline solution include potassium hydroxide, tribasic sodium phosphate, tribasic potassium phosphate, sodium aluminate, sodium metasilicate, sodium carbonate, and the like.
[0092]
As the alkaline solution, a sodium hydroxide solution containing a predetermined amount of aluminum ions is preferable.
In order to stably perform the alkali etching process, it is necessary to control the sodium hydroxide concentration in the alkali solution within a predetermined range, and when the alkali solution contains aluminum ions, the sodium hydroxide concentration is controlled to be within the predetermined range. It is preferable. The concentration of sodium hydroxide and aluminum ions in the alkaline solution is preferably 20 to 30% by mass and 5 to 9% by mass, respectively. The sodium hydroxide concentration and the aluminum ion concentration are controlled based on the specific gravity and conductivity of the alkaline solution. The specific gravity and the electrical conductivity are preferably controlled so that the fluctuation range is within ± 10%.
The liquid temperature of the alkaline solution is preferably 40 to 80 ° C.
[0093]
The alkali etching treatment can be performed using an etching apparatus usually used for the etching treatment of the aluminum plate. As an etching apparatus, for example, it has a tank for storing an alkaline solution, and has a form in which the aluminum plate is immersed in the tank, and a spray nozzle, and the alkali solution is directed from the spray nozzle toward the aluminum plate. The thing of the form to spray is mentioned. The etching apparatus may be a batch type or a continuous type.
[0094]
After the alkali etching treatment is completed, it is preferable to perform liquid removal by a nip roller and water washing by spraying so that the treatment liquid is not brought into the next step.
[0095]
<Desmutting treatment (c)>
In the alkali etching treatment (b), the aluminum plate is etched with an alkaline solution, so that smut is generated on the surface.
Therefore, after the alkali etching treatment (b) is completed, it is preferable to remove the surface smut by bringing the aluminum plate into contact with an acidic solution and performing a desmut treatment.
[0096]
The desmutting treatment can be performed by, for example, a method of immersing the aluminum plate in an acidic solution, a method of passing through the acidic solution, a method of spraying the acidic solution using a spray nozzle, or the like. Among these, the spraying method using a spray nozzle is preferable.
[0097]
Examples of the main acid component of the acidic solution include one or more acids selected from nitric acid, sulfuric acid, hydrochloric acid, and chromic acid. The concentration of the acid component is 0. 5-60 mass% is preferable. In the acidic solution, 0 to 5% by mass of aluminum ions and ions of the trace elements contained in the aluminum alloy forming the aluminum plate may be dissolved. Specifically, the acidic solution is preferably a nitric acid electrolytic solution containing 5 to 15 g / L of nitric acid or a sulfuric acid solution containing 80 to 300 g / L of sulfuric acid.
[0098]
Moreover, if the waste liquid discharged | emitted by the electrochemical roughening process (d) mentioned later or the anodizing process (j) mentioned later is used as an acidic solution, an electrochemical roughening process (d) and anodizing will be carried out. This is preferable because the amount of waste liquid discharged in the treatment (j) can be reduced.
The liquid temperature of the acidic solution is preferably from room temperature to 95 ° C, particularly preferably from 25 to 80 ° C.
The treatment time is preferably 1 to 30 seconds, particularly preferably 1 to 5 seconds.
[0099]
After the desmut treatment is completed, it is preferable to remove the liquid with a nip roller and wash with water so as not to bring the treatment liquid into the next process. However, as an acidic solution, a liquid of the same type and composition as the liquid used in the next process Alternatively, when the waste liquid discharged in the next step is used, the draining and washing can be omitted in order to reduce the amount of waste liquid.
[0100]
<Electrochemical roughening treatment (d) and (g)>
When the electrochemical surface roughening treatment is an electrochemical surface roughening treatment performed under specific conditions in an electrolytic solution containing nitric acid or hydrochloric acid, a specific specific R_a, R_maxThe lithographic printing plate support of the present invention having an intermetallic compound and simple substance Si is preferable in that it can be easily produced. The first electrochemical surface roughening treatment (d) is an electrochemical surface roughening treatment performed in a nitric acid electrolytic solution, and the second electrochemical surface roughening treatment (g) is performed in a hydrochloric acid electrolytic solution. The electrochemical roughening treatment to be performed can form a triple wave structure including the large wave, medium wave and small wave having the above-mentioned aperture diameter, and can further improve the uniformity of the pit shape, so that it is lithographic printing It is particularly preferable in terms of excellent printing durability, stain resistance and exposure stability when used as a plate.
[0101]
(1) Nitric acid electrolyte
The nitric acid concentration of the nitric acid electrolyte used in the electrochemical surface roughening treatment (d) is 0.2 to 2% by mass. Within this range, uniform pits can be formed by superimposing on the pits (waviness) generated by the mechanical surface-roughening process, so that the printing performance is excellent.
The nitric acid electrolyte includes one or more salts selected from nitrates such as aluminum nitrate, sodium nitrate and ammonium nitrate, and hydrochlorides such as aluminum chloride, sodium chloride and ammonium chloride in a range from 1 g / L to a saturated concentration. Can be added. A compound that forms a complex with copper may be added to the nitric acid electrolyte so as to have a concentration of 1 to 200 g / L. In the nitric acid electrolyte, trace elements contained in an aluminum alloy forming an aluminum plate such as iron, copper, manganese, nickel, titanium, magnesium, and silicon may be further dissolved. In addition, hypochlorous acid or hydrogen peroxide may be contained at a concentration of 1 to 100 g / L.
[0102]
As the nitric acid electrolyte, an aqueous solution in which an aluminum salt such as aluminum nitrate is added to dilute nitric acid containing 5 to 15 g / L of nitric acid to adjust the concentration of aluminum ions to 2 to 7 g / L is particularly preferable.
[0103]
In addition, when electrochemical surface roughening treatment is performed in a nitric acid electrolyte, ammonium ions are generated in the nitric acid electrolyte by a reduction reaction, so that the ammonium ion concentration in the nitric acid electrolyte is 50 to 150 ppm. It is particularly preferable to add ammonium nitrate in advance.
The temperature of the nitric acid electrolyte is preferably 30 to 80 ° C, and particularly preferably 35 to 60 ° C.
[0104]
The nitric acid concentration of the nitric acid electrolyte is controlled based on the sound speed and conductivity of the nitric acid electrolyte. Specifically, first, the sound speed and conductivity are measured for a plurality of nitric acid electrolytes having different nitric acid concentrations, and a calibration curve indicating the relationship between the nitric acid concentration, the sound speed, and the conductivity is obtained. Next, the sound velocity and the conductivity of the nitric acid electrolyte actually used in the electrochemical surface roughening treatment (d) are measured. From the measured values of the sound velocity and the conductivity and the above calibration curve, the nitric acid in the nitric acid electrolyte is measured. Determine the concentration.
[0105]
The nitric acid concentration is preferably controlled so that the fluctuation range of the sound velocity and the conductivity is within a range of ± 10%. This control can be performed by adding concentrated nitric acid to the nitric acid electrolyte or diluting with water.
[0106]
(2) Hydrochloric acid electrolyte
The hydrochloric acid concentration of the hydrochloric acid electrolyte used in the electrochemical surface roughening treatment (g) is 0.1 to 2% by mass, in other words, a hydrochloric acid electrolyte containing 1 to 20 g / L of hydrochloric acid. Within this range, uniform fine pits can be superimposed and formed, the surface area of the aluminum plate is increased, and printing performance is particularly excellent.
The hydrochloric acid electrolyte includes one or more salts selected from hydrochlorides such as aluminum chloride, sodium chloride and ammonium chloride, and nitrates such as aluminum nitrate, sodium nitrate and ammonium nitrate in a range from 1 g / L to a saturated concentration. Can be added.
A compound that forms a complex with copper can also be added to the hydrochloric acid electrolyte so as to have a concentration of 1 to 200 g / L. In the hydrochloric acid electrolyte, trace elements contained in an aluminum alloy forming an aluminum plate such as iron, copper, manganese, nickel, titanium, magnesium, and silicon may be dissolved. In addition, hypochlorous acid or hydrogen peroxide may be contained at a concentration of 1 to 100 g / L.
[0107]
As the hydrochloric acid electrolyte, a solution in which an aluminum salt such as aluminum chloride is added to dilute hydrochloric acid containing 2 to 15 g / L of hydrochloric acid to adjust the concentration of aluminum ions to 2 to 15 g / L is particularly preferable.
The liquid temperature of the hydrochloric acid electrolyte is preferably 20 to 50 ° C.
[0108]
The hydrochloric acid concentration of the hydrochloric acid electrolyte is controlled based on the sound speed and conductivity of the hydrochloric acid electrolyte, as in the case of the nitric acid electrolyte. Specifically, as with the nitric acid electrolyte, a calibration curve showing the relationship between the hydrochloric acid concentration of the hydrochloric acid electrolyte, the speed of sound, and the conductivity was obtained, and the hydrochloric acid electrolysis used in the electrochemical surface roughening treatment (g). The hydrochloric acid concentration of the hydrochloric acid electrolyte is determined from the measured values of the sound velocity and conductivity of the liquid and the calibration curve.
[0109]
The hydrochloric acid concentration of the hydrochloric acid electrolyte is also preferably controlled so that the fluctuation range of the sound velocity and the conductivity is within a range of ± 10%. This control can be performed by adding concentrated hydrochloric acid to the hydrochloric acid electrolyte or diluting with water.
[0110]
(3) Conditions for electrochemical roughening treatment
Alternating current is applied in both the electrochemical surface roughening treatments (d) and (g).
In the electrochemical surface roughening treatment (d), the amount of electricity when the aluminum plate participates in the anode reaction, that is, the amount of electricity at the time of anode is 10 to 800 C / dm.², Preferably 30-300 C / dm², Particularly preferably 100 to 250 C / dm²The alternating current is applied so that
Similarly, in the electrochemical surface roughening treatment (g), the amount of electricity at the time of anode is 10 to 800 C / dm.², Preferably 10 to 150 C / dm², Particularly preferably 15 to 50 C / dm²The alternating current is applied so that
On the other hand, when the mechanical surface roughening treatment (a) is not performed before the electrochemical surface roughening treatments (d) and (g), the electrochemical surface roughening treatments (d) and (g) ) The amount of electricity at the time of anode is 200 to 700 C / dm²Is preferable, and 350 to 600 C / dm is particularly preferable.²It is.
In the electrochemical surface roughening treatments (d) and (g), when the amount of electricity is within this range, pits are uniformly generated and good printing performance is obtained.
[0111]
As the alternating current, an alternating current having various waveforms such as a sine wave current, a rectangular wave current, a trapezoidal wave current, and a triangular wave current can be used, but a rectangular wave current and a trapezoidal wave current are preferable, and a trapezoidal wave is preferable. Current is particularly preferred.
The frequency of the alternating current is 0. 1 to 500 Hz is preferable.
[0112]
An example of the trapezoidal wave is shown in FIG. When the trapezoidal wave shown in FIG. 1 is used, the rise times tp ′ and tp until the current reaches a peak from 0 are preferably 0.1 to 10 msec. 5 to 2 msec is particularly preferable. Rise times tp 'and tp are 0. If it is 1 msec or longer, the influence of the impedance of the power supply circuit is small, so that a large power supply voltage is not required at the rise of the current waveform, so that the power supply circuit can be configured at low cost. In addition, when the rise times tp ′ and tp are 10 msec or less, in any of the electrochemical surface-roughening treatments (d) and (g), it is difficult to be influenced by a trace component in the nitric acid electrolytic solution or the hydrochloric acid electrolytic solution. Therefore, uniform roughening can be achieved.
[0113]
The ratio ta / T (duty) in which the anode reaction time ta of the aluminum plate occupies the AC cycle T is preferably 0.33 to 0.66 under the condition of one cycle of AC used for the electrochemical roughening treatment. 0. 45-0. 55 is more preferable, and 0.5 is particularly preferable.
[0114]
The amount of electricity applied to the aluminum plate facing the main electrode is preferably such that the ratio Qc / Qa of the amount of electricity Qc during the cathode reaction and the amount of electricity Qa during the anode reaction of the aluminum plate is 0.9-1. When Qc / Qa is within this range, processing unevenness due to the roughening treatment does not occur, and both printing durability and stain resistance can be achieved when a planographic printing plate is used. If Qc / Qa exceeds 1.0, the electrode may be dissolved. The control of the electric quantity ratio can be performed by controlling the voltage generated by the power source.
When the electrolytic cell shown in FIG. 2 is used, the electric quantity ratio can be adjusted by controlling the firing angle of the thyristor Th.
[0115]
In the electrochemical surface roughening treatments (d) and (g), the current density is a peak value of a trapezoidal wave and is 5 to 70 A / dm for both the anode cycle side Ia and the cathode cycle side Ic of the current.²Preferably 15 to 35 A / dm²It is.
In the electrochemical surface roughening treatments (d) and (g), when the electric density is within this range, surface quality deterioration such as cross streak can be prevented.
[0116]
In any of the electrochemical surface roughening treatments (d) and (g), a known electrolytic cell such as a vertical type, a flat type, or a radial type can be used as the electrolytic cell.
[0117]
FIG. 2 shows an example of the radial electrolytic cell.
In FIG. 2, 40 is an electrolytic cell, 42 is an electrolytic cell body, 44 is a feed roller, 46A and 46B are main electrodes, 48A and 48B are liquid supply nozzles, 54 is an auxiliary electrolytic cell, 56 is an auxiliary electrode, Th1 and Th2 are Thyristor 104 is a radial electrolytic cell, and W is an aluminum web.
[0118]
As shown in FIG. 2, the radial electrolytic cell 104 is disposed in an electrolytic cell 42 in which a nitric acid electrolytic solution or a hydrochloric acid electrolytic solution is stored, and in the electrolytic cell 42 so as to be rotatable around an axis extending in the horizontal direction. And a feed roller 44 that feeds the aluminum web W, which is a continuous thin plate, in the direction of arrow a, that is, from the left to the right in FIG.
[0119]
The inner wall surface of the electrolytic cell 42 is formed in a substantially cylindrical shape so as to surround the feed roller 44, and semi-cylindrical main electrodes 46 </ b> A and 46 </ b> B are provided on the inner wall surface with the feed roller 44 interposed therebetween. The main electrodes 46A and 46B are divided into a plurality of electrodes, and an insulating spacer is interposed between the electrodes. The electrode can be formed using, for example, graphite or metal, and the spacer can be formed using, for example, a vinyl chloride resin. The thickness of the spacer is preferably 1 to 10 mm. Further, although omitted in FIG. 2, in each of the main poles 46A and 46B, each of the electrodes divided by the spacer is connected to an AC power source AC.
[0120]
In the upper part of the electrolytic cell 42, an opening 42A into which the aluminum web W is introduced / derived is formed at the time of electrochemical surface roughening treatment with alternating current. In the vicinity of the opening 42A in the electrolytic cell 42 and between the main electrode 46A and the main electrode 46B, acidic electrolyte replenishing channels 48A and 48B for replenishing the electrolytic cell 42 with a nitric acid electrolytic solution or a hydrochloric acid electrolytic solution are provided. ing.
[0121]
In the vicinity of the opening 42 </ b> A above the electrolytic cell 42, an upstream guide roller 50 </ b> A that guides the aluminum web W into the electrolytic cell 42, and an aluminum plate W that has been electrolyzed in the electrolytic cell 42 are placed outside the electrolytic cell 42. A group of downstream guide rollers 50B for guiding is disposed.
[0122]
The radial electrolytic cell 104 is provided with an overflow tank 52 adjacent to the downstream side of the electrolytic cell 42. The overflow tank 52 temporarily stores the nitric acid electrolyte or hydrochloric acid electrolyte overflowed from the electrolytic tank 42 and has a function of keeping the liquid level of the nitric acid electrolyte in the electrolytic tank 42 constant.
In the radial electrolytic cell 104, an auxiliary electrolytic cell 54 is further provided adjacent to the downstream side of the electrolytic cell 42.
[0123]
The auxiliary electrolytic cell 54 is shallower than the electrolytic cell 42, has a bottom surface 54A formed in a flat shape, and a plurality of rod-shaped auxiliary electrodes 56 are provided on the bottom surface 54A.
[0124]
The auxiliary electrode 56 is preferably made of a highly corrosion-resistant metal such as platinum, ferrite, or the like, and may be plate-shaped.
The auxiliary electrode 56 is connected in parallel to the main electrode 46B on the side to which the main electrode 46B in the AC power supply AC is connected, and in the middle, the thyristor Th1 is connected to the AC power supply AC from the above side at the time of ignition. The connection is made so that a current flows in a direction toward the auxiliary electrode 56.
[0125]
Further, the side of the AC power source AC to which the main electrode 46A is connected is also connected to the auxiliary electrode 56 via the thyristor Th2. The thyristor Th2 is connected so that a current flows in a direction from the above side of the AC power supply AC toward the auxiliary electrode 56 at the time of ignition.
[0126]
An anode current flows through the auxiliary electrode 56 when any of the thyristors Th1 and Th2 is ignited. Accordingly, by controlling the phase of the thyristors Th1 and Th2, the current value of the anode current flowing through the auxiliary electrode 56 can be controlled, and thus Qc / Qa can also be controlled.
[0127]
The operation of the radial electrolytic cell 104 shown in FIG. 2 will be described below.
The aluminum plate W guided to the radial electrolytic cell 104 from the left in FIG. 2 along the arrow a is first introduced into the electrolytic cell 42 and then guided to the auxiliary electrolytic cell 54 by the downstream guide roller 50B. .
[0128]
Inside the electrolytic layer 42 and the auxiliary electrolytic cell 54, the aluminum plate W is on the side facing the main electrodes 46 A and 46 B due to the alternating current applied to the main electrodes 46 A and 46 B and the anode current applied to the auxiliary electrode 56. The surface of is roughened.
[0129]
Only one tank may be used, or two or more tanks may be used in series, but in the electrochemical surface-roughening treatment (d), one to three tanks should be used for the time series. Is particularly preferable, and in the electrochemical surface roughening treatment (g), it is particularly preferable to carry out in one tank. When two electrolytic cells are used in the electrochemical surface roughening treatment (d), the current density and the amount of electricity in the electrolytic cell on the first tank day are set to be higher than the current density and the amount of electricity in the second tank. It is particularly preferable to increase the height. Moreover, alternating current with the same waveform may be applied to all the electrolytic cells, or alternating current with a different waveform may be applied to each electrolytic cell. What type of alternating current is applied to which electrolytic cell can be determined according to the desired pit shape.
[0130]
A main electrode for applying an alternating current to the aluminum plate is provided inside the electrolytic cell.
In the electrolytic cell, it is preferable to arrange the runway and the main electrode of the aluminum plate so that the distance between the aluminum plate conveyed inside and the main electrode is 5 to 100 mm, preferably 8 to 15 mm. The main electrode is preferably formed of carbon.
[0131]
The average relative flow rate between the aluminum plate conveyed in the electrolytic cell and the nitric acid electrolytic solution or hydrochloric acid electrolytic solution flowing through the electrolytic cell is preferably 1 to 1000 m / min, and particularly preferably 15 to 300 m / min. As long as the average relative flow velocity is within the above range, the flow direction of the nitric acid electrolytic solution or hydrochloric acid electrolytic solution may be either the same direction as the conveying direction of the aluminum plate or the opposite direction.
[0132]
In addition, it is preferable for uniform electrochemical surface roughening that the distance between the scissors of the aluminum plate and the main electrode and the flow rates of the nitric acid electrolyte and hydrochloric acid electrolyte are kept constant. .
[0133]
In flat type and vertical type electrolytic cells, as described in Japanese Examined Patent Publication No. 61-30036, a surface formed so that a traveling aluminum plate can slide is provided inside, and static pressure is used. The distance can be kept constant by running the aluminum plate in pressure contact. Further, in the radial type electrolytic cell, as described in JP-A-8-300843, a roller having a large diameter for conveying the aluminum plate is provided therein, and a plurality of rollers are provided so as to surround the roller. By disposing the main electrode on the circumference, the distance between the main electrode and the aluminum plate can be kept constant.
[0134]
Further, in order to make the flow rates of the nitric acid electrolytic solution and the hydrochloric acid electrolytic solution constant, a liquid storage chamber is provided inside the electrolytic cell, and a liquid blowing chamber with a width of 1 to 5 mm is provided along the width direction of the aluminum plate traveling inside. The nitric acid electrolytic solution and the hydrochloric acid electrolytic solution may be supplied using a liquid supply nozzle provided with a slit. Further, a plurality of liquid storage chambers may be provided, and each liquid storage chamber may be connected by a pipe line including a valve and a flow meter to adjust the amount of liquid blown out from each slit of the liquid supply nozzle.
[0135]
Examples of the power feeding method to the aluminum plate traveling inside the electrolytic cell include a direct power feeding method using a conductor roller, a liquid power feeding method not using the conductor roller, in other words, an indirect power feeding method.
In the electrolytic cell, when the indirect power feeding method is used, the current value can be controlled using a transformer, a variable induction voltage regulator, and the like.
[0136]
Further, in addition to the main electrode, an auxiliary electrode for applying a direct current is provided inside the electrolytic cell, and the amount of electricity applied to the aluminum plate during the anode is controlled by controlling the strength of the direct current flowing through the auxiliary electrode. The ratio of the amount of electricity at the cathode can be adjusted. The auxiliary electrode can be formed of ferrite or the like.
[0137]
As a method of controlling the current flowing through the auxiliary electrode, as described in Japanese Patent Publication No. 6-37716 and Japanese Patent Publication No. 5-42520, phase control by a control rectifier such as a thyristor and GTO, and a diode and a variable Control by a resistor and the like can be mentioned. By controlling the current flowing through the auxiliary electrode by the above method, it is possible to reduce the influence of the magnetic bias of the transformer and to manufacture the power supply device at a low cost, which is very advantageous in terms of cost.
[0138]
In the case of using the direct power feeding method, as described in JP-A-58-177441, the conductor roller is cast using industrial aluminum, subjected to high-temperature homogenization treatment, and AlFe-based surface portion. Shodatsu Al₃A conductor roller having improved corrosion resistance by changing to a single phase of Fe can be used. Further, as described in JP-A-56-123400, a conductor roller is provided in an introduction portion of an aluminum plate in a flat or vertical electrolytic cell, or in both the introduction portion and the lead-out portion of the aluminum plate. It is possible to use an electrolytic cell in which is disposed.
[0139]
In the electrolytic cell, the conductor roller can be provided so as to be in contact with the upper surface or the lower surface of the aluminum plate, but is provided so as to be in contact with the upper surface of the aluminum plate and is pressed against the aluminum plate by a nip device. It is particularly preferable to do this. The length of the aluminum plate contacting the conductor roller is preferably 1 to 300 mm with respect to the aluminum traveling direction. The pass roller facing the conductor roller across the aluminum plate is preferably a rubber roller having a rubber cylinder. The pressing pressure of the conductor roller and the hardness of the cylinder of the rubber roller can be arbitrarily set under the condition that no arc spot is generated at the contact point between the conductor roller and the aluminum plate. By installing the conductor roller so as to be in contact with the upper surface of the aluminum plate, the conductor roller can be easily replaced and inspected. In order to energize the conductor roller, it is preferable to provide a rotating body concentrically at the end of the conductor roller and energize while sliding the power supply brush on the rotating body.
[0140]
The conductor roller is preferably always cooled with the nitric acid electrolytic solution or the hydrochloric acid electrolytic solution in order to prevent the occurrence of an arc spot.
[0141]
<Alkali etching treatment (e)>
By performing alkali etching treatment (e) after electrochemical surface roughening treatment (d), the aluminum hydroxide film formed on the surface of the aluminum plate in the electrochemical surface roughening treatment can be removed. .
The alkali etching process (e) is basically the same as the alkali etching process (b), and only the differences will be described below.
The amount of aluminum dissolved in the alkali etching treatment (e) is 0. 01-7g / m²And 0. 01-5g / m²Is preferred, 0.01-3 g / m²Is particularly preferred.
Within this range, steep portions of pits can be efficiently dissolved without reducing the surface area of the aluminum plate.
As for the liquid temperature of an alkaline solution, 30-80 degreeC is preferable.
[0142]
<Desmutting treatment (f)>
In the alkali etching process (e), since the aluminum plate is etched with an alkaline solution, smut is generated on the surface.
Therefore, after the alkali etching treatment (e) is completed, it is preferable to remove the surface smut by bringing the aluminum plate into contact with an acidic solution and performing a desmut treatment.
[0143]
The desmut treatment (f) is basically the same as the desmut treatment (c), except that a sulfuric acid solution containing 80 to 500 g / L of sulfuric acid is suitably used as the acidic solution.
[0144]
<Alkali etching treatment (h)>
By performing the alkali etching treatment (h) after the electrochemical roughening treatment (g), the aluminum hydroxide film formed on the surface of the aluminum plate in the electrochemical roughening treatment can be removed.
The alkali etching process (h) is basically the same as the alkali etching process (b), and only the differences will be described below.
The amount of aluminum dissolved in the alkali etching treatment (h) is 0. 001-6g / m²And 0. 01-5g / m²Is preferred, 0.005-0.8 g / m²Is particularly preferred.
Within this range, steep portions of pits can be efficiently dissolved without reducing the surface area of the aluminum plate.
The concentration of sodium hydroxide and aluminum ions in the alkaline solution is preferably 4 to 6% by mass and 0.3 to 0.7% by mass, respectively.
The liquid temperature of the alkaline solution is preferably 25 to 80 ° C.
[0145]
<Desmut treatment (i)>
In the alkali etching treatment (h), the aluminum plate is etched with an alkaline solution, so that smut is generated on the surface.
Therefore, after the alkali etching treatment (h) is finished, it is preferable to remove the surface smut by bringing the aluminum plate into contact with an acidic solution and performing a desmut treatment.
[0146]
The desmut treatment (i) is basically the same as the desmut treatment (c), except that a sulfuric acid solution containing 80 to 500 g / L of sulfuric acid is preferably used as the acidic solution.
In addition, if the waste liquid discharged in the anodizing treatment (j) is used as the acidic solution, not only can the amount of waste liquid be greatly reduced, but also the anodization is immediately performed without washing the aluminum plate after the desmutting treatment (i). Since it can transfer to a process, it is also preferable at the point which can eliminate the cleaning equipment between a desmut processing apparatus and an anodizing apparatus.
[0147]
<Anodizing treatment (j)>
In the present invention, the anodic oxidation treatment is performed in an acidic solution containing sulfuric acid and aluminum ions having a concentration of 5% by mass or more, and the oxide film amount is 1 to 5 g / m.²Is preferred. It is also preferable to perform a hydrophilic treatment and / or a sealing treatment after the anodizing treatment.
A sulfuric acid solution containing sulfuric acid is used for anodizing the aluminum plate. The amount of anodized film is 1-5g / m²Is preferred. The amount of anodized film is 1g / m²If it is as described above, sufficient printing durability can be obtained, so that the non-image part of the lithographic printing plate is hardly scratched, and therefore, so-called flaw stains in which ink adheres to the scratched part are unlikely to occur. When the amount of the anodized film increases, the oxide film tends to concentrate on the edge portion of the aluminum plate, but the amount of the anodized film is 5 g / m.²Such a problem does not occur when the following is true. However, the difference in the amount of oxide film between the edge and center of the aluminum plate is 1 g / m²The following is preferable.
[0148]
As described in detail in JP-A-54-128453 and JP-A-48-45303, the sulfuric acid aqueous solution has a sulfuric acid concentration of 10 to 300 g / L and an aluminum ion concentration of 1 A sulfuric acid aqueous solution of ˜25 g / L is preferable, the sulfuric acid concentration is 80 to 200 g / L, and the concentration of aluminum ions is particularly preferably 2 to 10 g / L.
Within this range, it is possible to prevent the aluminum plate from being dissolved by the sulfuric acid solution while maintaining the desmutting ability.
The liquid temperature is preferably from 30 to 60 ° C, particularly preferably from 30 to 55 ° C.
[0149]
The sulfuric acid concentration and aluminum ion concentration are controlled by specific gravity and conductivity. Specifically, it can be controlled by replenishing the sulfuric acid solution with water or replenishing concentrated sulfuric acid while measuring the specific gravity and conductivity of the sulfuric acid solution continuously or at regular intervals. This control is preferably performed so that the fluctuation range of the specific gravity and conductivity is within ± 10%.
[0150]
The anodizing treatment is usually performed by applying a direct current to the aluminum plate, but an alternating current may be applied.
[0151]
When anodizing is performed using direct current, the current density is 1 to 60 A / dm.²Is preferred, 5-40 A / dm²Is particularly preferred. When anodizing the aluminum plate continuously, 5-10 A / dm on the most upstream side in order to prevent current concentration called burning of the aluminum plate.²The current density is gradually increased toward the downstream side by 30 to 50 A / dm.²Alternatively, the current density is preferably increased to a higher value. It is preferable to gradually increase the current density in 5 to 15 steps. By providing an independent power supply device for each step and controlling the current density in each of the power supply devices, the current density is gradually reduced toward the downstream side. Can be increased. The method for feeding the aluminum plate is preferably an indirect feeding method (liquid feeding method) described later without using a conductor roller. An example is shown in Japanese Patent Laid-Open No. 2001-11698.
[0152]
As a power feeding method to the aluminum plate, there are a direct power feeding method and an indirect power feeding method as in the case of the electrochemical roughening treatment.
The direct power supply method is disadvantageous due to the problem of spark generation between the conductor roller and the aluminum web at high speed and high current density, so it is a relatively slow and low current density anodizing device with a line speed of 30 m / min or less. The indirect power feeding method is often used in a high-speed and high-current density anodizing apparatus in which the line speed exceeds 30 m / min.
When using the indirect power supply method, a Yamakoshi type or straight type tank layout can be used as described on page 289 of the continuous surface treatment technology (General Technology Center, issued on September 30, 1986).
In both direct power supply and indirect power supply systems, the anodizing process is separated into two or more for the purpose of reducing energy loss due to voltage drop in the aluminum web. It is particularly preferable to connect a direct current power source between the oxidation tanks.
When the direct power feeding method is used, the conductor roller similar to the conductor roller described in the above <electrochemical roughening treatment> can be used.
[0153]
Since a large current flows in the anodizing process, a Lorentz force acts on the aluminum plate by a magnetic field generated by the current flowing in the bus bar. As a result, there arises a problem that the web meanders, and it is particularly preferable to use a method as described in JP-A-57-51290.
[0154]
Further, since a large current flows through the aluminum plate, a Lorentz force acts toward the center in the width direction of the aluminum plate by a magnetic field generated by the current flowing through the aluminum plate itself. As a result, the aluminum plate is likely to be broken, so a plurality of pass rollers having a diameter of 100 to 200 mm are provided at a pitch of 100 to 3000 mm in the anodizing treatment tank and wrapped at an angle of 1 to 15 degrees to prevent folding due to Lorentz force. It is particularly preferred to take the method of:
[0155]
In addition, the amount of the anodic oxide film that is generated increases as the distance from the edge of the aluminum plate increases, and the thickness of the anodic oxide film increases. The above problem can be solved by stirring an acidic electrolytic solution as described in Japanese Patent Publication No. Sho 62-30275 and Japanese Patent Publication No. 55-21840. If the above problem cannot be sufficiently solved even by stirring the acidic electrolyte, the winding device is set to 0. 0. If the aluminum plate is oscillated in the width direction of the aluminum plate with a period of 1 to 10 Hz and an amplitude of 5 to 50 mm, the problem of winding the aluminum plate can be solved.
[0156]
For example, lead, iridium oxide, platinum, ferrite, or the like can be used as the anode for passing an electric current through the aluminum plate, but those mainly composed of iridium oxide are particularly preferable. Iridium oxide can be coated on the substrate by heat treatment. As the substrate, for example, so-called valve metals such as titanium, tantalum, niobium, and zirconium are used, and titanium or niobium is particularly preferable. Since the valve metal has a relatively large electric resistance, it is particularly preferable to use copper as the core and clad the valve metal around it. When a valve metal is clad on a copper core material, it is not possible to make a very complicated shape. Therefore, the electrode parts made by dividing each part are coated with iridium oxide and then the desired structure with bolts and nuts etc. It is common to assemble so that it becomes.
[0157]
<Hydrophilic treatment>
An anodized aluminum plate has an anodized film dissolved in a developer, a residual film of an image recording layer in a non-image area is suppressed, an anodized film strength, hydrophilicity, an image recording layer and a support For the purpose of improving the adhesiveness, etc., after being washed with water, a hydrophilic treatment can be performed.
[0158]
Examples of the hydrophilization treatment include a silicate treatment in which the anodized film is brought into contact with an aqueous solution of an alkali metal silicate.
The silicate treatment is an alkali having an alkali metal silicate concentration of usually 0.1 to 30% by mass, preferably 0.5 to 15% by mass, and a pH at 25 ° C. of 10 to 13.5. The aluminum plate can be brought into contact with an aqueous solution of metal silicate usually at 5 to 80 ° C., preferably 10 to 70 ° C., more preferably 15 to 50 ° C. for 0.5 to 120 seconds.
As the alkali metal silicate, for example, sodium silicate, potassium silicate, lithium silicate or the like is used.
[0159]
The alkali metal silicate aqueous solution gels when the pH is lower than 10, and the anodic oxide film dissolves when the pH is higher than 13.5. Therefore, the pH of 10 to 13.5 does not cause the problem of gelation and dissolution of the anodic oxide film. Is preferred.
For adjusting the pH of the aqueous solution of the alkali metal silicate, for example, an alkali metal hydroxide such as sodium hydroxide, potassium hydroxide or lithium hydroxide is used.
[0160]
The aqueous solution may contain an alkaline earth metal salt or a Group IVA (Group 4) metal salt.
Examples of alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, sulfates, hydrochlorides, phosphates, acetates, oxalates, borates, and the like. A water-soluble salt is mentioned.
Examples of the Group IVA (Group 4) metal salt include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride oxide and the like.
Alkaline earth metals and Group IVA (Group 4) metal salts can be used alone or in combination of two or more. A preferable blending amount of the alkaline earth metal and the Group IVA (Group 4) metal salt is 0.01 to 10% by mass, particularly preferably 0.05 to 5% by mass.
[0161]
Examples of the method of bringing the aluminum plate into contact with the aqueous solution of the alkali metal silicate include a dipping method and a spraying method. However, the method is not limited to these methods.
[0162]
<Sealing treatment>
In addition to the hydrophilic treatment, the aluminum plate may be subjected to a sealing treatment.
[0163]
Examples of the sealing treatment include water vapor sealing, boiling water (hot water) sealing, metal salt sealing (chromate / bichromate sealing, nickel acetate sealing, etc.), oil-impregnated sealing, synthesis Resin sealing, low-temperature sealing (due to red blood salt, alkali salt, etc.) and the like include known processing as sealing processing of the anodized film, but performance as a printing plate support (image recording layer and From the viewpoint of high-speed processing, low cost, low pollution, and the like.
[0164]
As the water vapor sealing, for example, pressurized or normal pressure water vapor is continuously or discontinuously brought into contact with the anodized film for about 2 to 180 seconds at a relative humidity of 70% or more and a vapor temperature of 95 ° C. or more. The method described in 176690 gazette etc. are mentioned.
[0165]
Examples of other sealing treatment methods include immersion treatment in hot water or an aqueous alkaline solution, spray treatment of hot water or an aqueous alkaline solution, immersion treatment in an aqueous nitrite solution, and an injection treatment of an aqueous nitrite solution. It is done. The immersion treatment and spraying treatment in the aqueous nitrite solution may be performed in place of the immersion treatment and spraying treatment in the hot water or alkaline aqueous solution, or may be performed subsequent to the above treatment.
[0166]
Examples of the nitrite include Group IA (Group 1), Group IIA (Group 2), Group IIB (Group 12), Group IIIB (Group 13), Group IVB (Group 14), Group IVA (Group 4). ), Metal nitrites which are metal nitrites of Group VIA (Group 6), Group VIIA (Group 7), Group VIII (Groups 8 to 10), and ammonium nitrite.
[0167]
Examples of the metal nitrite include LiNO.₂, NaNO₂, KNO₂, Mg (NO₂)₂, Ca (NO₂)₂, Zn (NO₂)₂, Al (NO₂)₃, Zr (NO₂)₄, Cr (NO₂)₃, Co (NO₂)₂, Mn (NO₂)₂, Ni (NO₂)₂Etc., and alkali metal nitrates are particularly preferable. Nitrite can also use 2 or more types together.
[0168]
The treatment conditions vary depending on the state of the aluminum plate and the type of nitrite and cannot be uniquely determined. For example, when sodium nitrite is used, the concentration is generally 0.001 to 10% by mass. More preferably, it is 0.01-2 mass%. The bath temperature is generally from room temperature to about 100 ° C., more preferably 60 to 90 ° C. The treatment time is generally 15 to 300 seconds, more preferably 10 to 180 seconds.
[0169]
The pH of the aqueous nitrite solution is preferably adjusted to 8.0 to 11.0, and particularly preferably adjusted to 8.5 to 9.5. In order to adjust the pH of the aqueous nitrite solution to the above range, it can be suitably adjusted by using, for example, an alkaline buffer. Examples of the alkaline buffer include a mixed aqueous solution of sodium hydrogen carbonate and sodium hydroxide, a mixed aqueous solution of sodium carbonate and sodium hydroxide, a mixed aqueous solution of sodium carbonate and sodium hydrogen carbonate, a mixed aqueous solution of sodium chloride and sodium hydroxide, hydrochloric acid. An aqueous solution of sodium carbonate and sodium carbonate, an aqueous solution of sodium tetraborate and sodium hydroxide, and the like can be preferably used, but are not limited thereto. In addition, the alkali buffer may be an alkali metal salt other than a sodium salt, such as a potassium salt.
[0170]
In order to further improve the adhesion with the image recording layer after performing at least one of the hydrophilic treatment and the sealing treatment, an acidic aqueous solution treatment and a hydrophilic undercoat described in JP-A-5-278362 are used. Alternatively, an organic layer described in JP-A-4-282637 and Japanese Patent Application No. 6-108678 (JP-A-07-314937) may be provided.
[0171]
<Washing treatment>
In order to remove the chemical solution and the abrasive used in each of the above treatments from the surface of the aluminum plate, a water washing step of washing the aluminum plate with water may be provided between the above treatments.
[0172]
In the water washing step, the water washing treatment is usually performed between treatment tanks using different types and compositions of chemical solutions. The time for the aluminum plate to leave the one processing tank and enter the cleaning process, and the time from the end of the cleaning process to the next processing tank adjacent to the one cleaning tank is preferably 10 seconds or less. 0.1 to 10 seconds is particularly preferable. When the time is 10 seconds or less, the chemical modification of the surface of the aluminum plate does not progress so much, and thus processing unevenness is unlikely to occur. Further, the passage time of the aluminum plate from the one treatment tank to the next treatment tank is preferably 15 seconds or less, particularly preferably 5 seconds or less. When the passage time is 15 seconds or less, chemical modification of the surface of the aluminum plate hardly proceeds, and a uniform roughening treatment can be performed in the next step.
[0173]
In the water washing step of the aluminum plate, the surface that has been drained by the nip roller is generally washed by spraying water from a spray tip in a washing tank. The water is preferably jetted at an angle of 45 to 90 degrees downstream.
The water injection pressure is 0.5-5 kg / cm just before the injection nozzle.²The water temperature is preferably 10 to 80 ° C.
The conveyance speed of the aluminum plate is preferably 20 to 200 m / min.
The amount of washing water sprayed on the aluminum plate is 0.1 to 10 L / m per washing step.²Is preferred.
[0174]
In the washing tank, the washing water is preferably sprayed from at least two spray tubes onto the front and back surfaces of the aluminum plate. It is preferable to install 5 to 30 spray tips at a pitch of 50 to 200 mm in one spray tube. The spray angle of the spray tip is preferably 10 to 150 degrees, and the distance between the aluminum plate and the spray tip injection surface is preferably 10 to 250 mm. The cross-sectional shape (spray pattern) of spraying of the spray tip includes an annular shape, a circular shape, an oval shape, a square shape, a rectangular shape, and the like, but a circular shape, a round shape, or a square shape and a rectangular shape are preferable. The flow distribution (spray water distribution state on the surface of the aluminum plate) includes annular distribution, uniform distribution, mountain distribution, etc., but when using multiple spray tips side by side in a spray tube, the uniform flow distribution over the entire width A mountain distribution that facilitates the above is preferred. The flow distribution varies depending on the spray pressure and the distance between the spray tip and the aluminum plate. The particle diameter of the spray varies depending on the structure of the spray tip, the spray pressure, and the spray amount, but is preferably 10 to 10,000 μm, particularly preferably 100 to 1000 μm. The material of the spray nozzle is preferably wear-resistant against a liquid flowing at high speed, and brass, stainless steel, ceramic, etc. are used, and ceramic is particularly preferable.
[0175]
The spray nozzle provided with the spray tip can be arranged at an angle of 45 to 90 degrees with respect to the traveling direction of the aluminum plate, but the longer center line of the spray pattern center line is the aluminum plate. It is preferable to be perpendicular to the traveling direction.
[0176]
The time of the water washing treatment is industrially preferably 10 seconds or less per one water washing step, and is particularly preferably 0. 5 to 5 seconds is preferable.
[0177]
<Material of pass roller>
In the treatment tank and the washing tank for performing each of the above treatments, a pass roller that conveys or supports the aluminum plate can be provided.
As the pass roller, a metal roller, a resin roller, a rubber roller, a nonwoven fabric roller, or the like whose surface is used for a continuous production line such as a steel line, a plating line, an electrolytic capacitor production line, a PS plate production line, or the like is used. Can do.
[0178]
The material of the pass roller and the physical properties of the surface are selected in consideration of the required corrosion resistance, wear resistance, heat resistance, chemical resistance, etc. according to the chemical solution used for the above treatment and the surface condition of the aluminum plate. .
As the metal roller, a hard chrome plating roller is generally used.
Rubber rollers such as natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, butyl rubber, chlorobrene rubber, chlorosulfonated polyethylene, nitrile rubber, acrylic rubber, epichlorohydrin rubber, urethane rubber, polysulfide rubber, fluorine rubber, etc. , And a roller having a cylinder made from the above rubber added with a small amount of additive. The hardness of the barrel of the rubber roller is particularly preferably 60 to 90.
[0179]
Moreover, when controlling the conveyance speed of an aluminum web in a location where the aluminum plate is wet and slippery, it is particularly preferable to use a nonwoven fabric roller that does not easily slip even when the aluminum web is wet. When a rubber roller is used at the above location, it is particularly preferable to provide an auxiliary drive motor on the roller.
[0180]
It is possible to improve the uniformity of the pit shape generated by the surface roughening treatment described above, particularly by the electrochemical surface roughening treatment under specific conditions. Excellent. In addition, since the volume of the image recording layer entering the uniform pit (the film thickness of the image recording layer provided on the aluminum plate) can be made uniform, the exposure stability when using a lithographic printing plate is excellent.
[0181]
[Lithographic printing plate precursor]
Next, the planographic printing plate precursor of the present invention will be described. The lithographic printing plate precursor according to the invention comprises an image recording layer provided on the lithographic printing plate support according to the invention.
[0182]
<Undercoat layer>
In the lithographic printing plate precursor according to the present invention, before providing an image recording layer on the lithographic printing plate support of the present invention obtained as described above, if necessary, for example, zinc borate or the like. An inorganic undercoat layer such as a water-soluble metal salt or an organic undercoat layer may be provided.
[0183]
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; phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid, ethylenediphosphonic acid, etc., 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 hydroxy group such as triethanolamine hydrochloride; and the yellow dye. These may be used alone or in combination of two or more.
[0184]
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 / m²Is preferably 5 to 100 mg / m²It is more preferable that When it is in the above range, the printing durability becomes better.
[0185]
<Image recording layer>
The lithographic printing plate support of the present invention can be provided with an image recording layer such as a photosensitive layer and a heat-sensitive layer as exemplified below to form a lithographic printing plate precursor. Suitable examples of the image recording layer include a conventional positive type, a conventional negative type, a photopolymer type, a thermal positive type, a thermal negative type, and an unprocessable type that can be developed on the machine. Hereinafter, these suitable image recording layers will be described.
[0186]
<Conventional positive type>
Examples of the photosensitive resin composition suitably used for the conventional positive type photosensitive layer include an o-quinonediazide compound and a water-insoluble and alkali-soluble polymer compound (hereinafter referred to as “alkali-soluble polymer compound”). The composition to contain is mentioned.
Examples of o-quinonediazide compounds include esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and phenol-formaldehyde resin or cresol-formaldehyde resin, and US Pat. No. 3,635,709. Examples include esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and pyrogallol / acetone resin as described.
Examples of the alkali-soluble polymer compound include phenol / formaldehyde resin, cresol / formaldehyde resin, phenol / cresol / formaldehyde co-condensation resin, polyhydroxystyrene, N- (4-hydroxyphenyl) methacrylamide copolymer, Carboxy group-containing polymers described in JP-A-7-36184, acrylic resins containing phenolic hydroxy groups as described in JP-A-51-34711, and JP-A-2-866. Examples thereof include acrylic resins having sulfonamide groups and urethane resins.
Further, in the photosensitive resin composition, compounds such as a sensitivity adjusting agent, a baking agent, and a dye 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.
[0187]
<Conventional negative type>
Examples of the photosensitive resin composition suitably used for the conventional negative type photosensitive layer include a composition containing a diazo resin and an alkali-soluble or swellable polymer compound (hereinafter referred to as “binder”).
Examples of the diazo resin include a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound such as formaldehyde, a condensate of p-diazophenylamines and formaldehyde, and a hexafluorophosphate or a tetrafluoroborate. Organic solvent-soluble diazo resin inorganic salts which are reaction products of In particular, a high molecular weight diazo compound containing 20 mol% or more of a hexamer described in JP-A-59-78340 is preferable.
Suitable binders include, for example, a copolymer containing acrylic acid, methacrylic acid, crotonic acid or maleic acid as an essential component, specifically 2 as described in JP-A-50-118802. -Multi-component copolymers of monomers such as hydroxyethyl (meth) acrylate, (meth) acrylonitrile, (meth) acrylic acid, alkyl acrylates as described in JP-A-56-4144, (meth) acrylonitrile And multi-component copolymers composed of unsaturated carboxylic acids.
Furthermore, plastics for imparting flexibility and abrasion resistance to the photosensitive resin composition described in JP-A-7-281425, [0014] to [0015]. It is preferable to add a compound such as an agent and a development accelerator and a surfactant for improving the coating property.
As a lower layer of the above-mentioned conventional type positive type or negative type photosensitive layer, a polymer compound having a component having an acid group and a component having an onium group described in JP-A-2000-105462 is used. It is preferable to provide an intermediate layer to be contained.
[0188]
<Photopolymer type>
A photopolymerization type photosensitive composition (hereinafter referred to as “photopolymerizable composition”) suitably used for a photopolymer type photosensitive layer is an addition-polymerizable ethylenically unsaturated bond-containing compound (hereinafter simply referred to as “ethylene”). ), A photopolymerization initiator, and a polymer binder as essential components, and if necessary, various compounds such as a colorant, a plasticizer, and a thermal polymerization inhibitor. Containing.
The ethylenically unsaturated bond-containing compound contained in the photopolymerizable composition is such that, when the photopolymerizable composition is irradiated with actinic rays, it undergoes addition polymerization by the action of the photopolymerization initiator, crosslinks and cures. It is a compound having an ethylenically unsaturated bond. The ethylenically unsaturated bond-containing compound can be arbitrarily selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more, such as monomers, prepolymers (ie, dimers). Trimers and oligomers), mixtures thereof, and copolymers thereof. Examples of monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid) and aliphatic polyhydric alcohol compounds, unsaturated carboxylic acids and aliphatic polyhydric compounds. And amides with a polyvalent amine compound. Urethane addition polymerizable compounds are also suitable.
[0189]
As the photopolymerization initiator contained in the photopolymerizable composition, various photopolymerization initiators or a combination system (photoinitiation system) of two or more photopolymerization initiators are appropriately selected depending on the wavelength of the light source used. For example, an initiation system described in JP-A-2001-22079, [0021] to [0023] is preferable.
The polymer binder contained in the photopolymerizable composition not only functions as a film-forming agent for the photopolymerizable composition, but also needs to dissolve the photosensitive layer in an alkali developer. An organic high molecular weight polymer that is swellable is used. As the polymer binder, those described in [0036] to [0063] of the same publication are useful.
It is preferable to add the additive (for example, surfactant for improving applicability | paintability) described in [0079]-[0088] of the same gazette to the photopolymerizable composition.
Further, it is preferable to provide an oxygen-blocking protective layer on the photosensitive layer in order to prevent the oxygen polymerization inhibiting action. Examples of the polymer contained in the oxygen barrier protective layer include polyvinyl alcohol and copolymers thereof.
Further, it is also preferable to provide an intermediate layer or an adhesive layer as described in [0131] to [0165] of JP-A-2001-228608 as the lower layer of the photosensitive layer.
[0190]
<Thermal positive type>
The thermal positive type heat-sensitive layer contains an alkali-soluble polymer compound and 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 (—SO₂Those 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 [0023] to [0042] of JP-A No. 2001-305722 are preferably used.
[0191]
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.
In the composition used for the thermal positive type heat-sensitive layer, the same sensitivity control agent, bake-out agent, dye, etc. as those described in the conventional positive type, and a surfactant for improving coating properties are added. It is preferable to add. Specifically, the compounds described in [0053] to [0059] of JP-A No. 2001-305722 are preferable.
The thermal positive type heat-sensitive layer may be a single layer or may have a two-layer structure as described in JP-A-11-218914.
An undercoat layer is preferably provided between the thermal positive type 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].
[0192]
<Thermal negative type>
The thermal negative-type heat-sensitive layer is a negative-type heat-sensitive layer in which the infrared laser irradiation part is cured to form an image part.
A preferred example of such a thermal negative type heat-sensitive layer is a polymerization type layer (polymerization layer). The polymerization layer comprises (A) an infrared absorber, (B) a radical generator (radical polymerization initiator), a curing reaction caused by the generated radical (C) a radical polymerizable compound, and (D) a binder. Containing polymer.
In the polymerization layer, the infrared rays absorbed by the infrared absorber are converted into heat, and the generated heat decomposes radical polymerization initiators such as onium salts to generate radicals. The radically polymerizable compound is selected from compounds having a terminal ethylenically unsaturated bond, and a polymerization reaction is caused in a chain by the generated radicals and is cured.
Examples of (A) infrared absorbers include the above-described photothermal conversion substances contained in the above-described thermal positive type heat-sensitive layer. In particular, specific examples of cyanine dyes are disclosed in JP-A No. 2001-133969. To [0019], and (B) radical generators include onium salts. Specific examples of onium salts that can be suitably used include those described in JP-A-2001-133969. The compounds described in [0030] to [0033] are mentioned, and the (C) radical polymerizable compound is selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more. (D) It is preferable to use a linear organic polymer as the binder polymer, and a linear organic polymer that is soluble or swellable in water or weak alkaline water is selected. Of these, a (meth) acrylic resin having a benzyl group or an allyl group and a carboxy group in the side chain is particularly preferable because of its excellent balance of film strength, sensitivity, and developability. Regarding (C) the radical polymerizable compound and (D) the binder polymer, those described in detail in [0036] to [0060] of the same publication can be used. As other additives, it is also preferable to add the additives described in [0061] to [0068] of the same publication (for example, a surfactant for improving coatability).
[0193]
In addition to the polymerization type, an acid cross-linked layer (acid cross-linked layer) is preferably used as one of the thermal negative type heat-sensitive layers. The acid cross-linking layer includes (E) a compound that generates an acid by light or heat (hereinafter referred to as “acid generator”) and (F) a compound that cross-links by the generated acid (hereinafter referred to as “cross-linking agent”). And (G) an alkali-soluble polymer compound that can react with a crosslinking agent in the presence of an acid. In order to efficiently use the energy of the infrared laser, (A) an infrared absorber is blended in the acid crosslinking layer. Examples of the acid generator (E) include compounds capable of generating an acid upon thermal decomposition, such as a photoinitiator for photopolymerization, a photochromic agent for dyes, and an acid generator used for a microresist. . (F) As the crosslinking agent, (i) an aromatic compound substituted with a hydroxymethyl group or an alkoxymethyl group, (ii) a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, (Iii) An epoxy compound is mentioned. (G) Examples of the alkali-soluble polymer compound include novolak resins and polymers having a hydroxyaryl group in the side chain.
[0194]
<Non-treatment type>
The untreated type heat-sensitive layer includes types such as a thermoplastic fine particle polymer type, a microcapsule type, and a sulfonic acid-generating polymer-containing type.
In the thermoplastic fine particle polymer type, (H) hydrophobic hot-melt resin fine particles are dispersed in (J) a hydrophilic polymer matrix, and the hydrophobic polymer is melted by the heat of the exposed area and fused to each other. To form a hydrophobic region, that is, an image portion.
(H) Hydrophobic heat-meltable resin fine particles (hereinafter referred to as “fine-particle polymer”) are preferably those in which fine-particle polymers are melted and coalesced by heat, have a hydrophilic surface, and are used as hydrophilic components such as dampening water. Dispersed particulate polymers having a hydrophilic surface are preferred. As the fine particle polymer, Research Disclosure No. 33303 (January 1992), JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, JP-A-9-171250, and European Patent Application Publication No. 931,647. Preferred examples thereof include thermoplastic fine particle polymers. Specific examples include homopolymers or copolymers of monomers such as ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, or mixtures thereof. . Of these, polystyrene and polymethyl methacrylate are preferably used. The fine particle polymer having a hydrophilic surface is such that the polymer itself constituting the fine particle is hydrophilic, or the polymer itself is hydrophilic, such as those obtained by introducing a hydrophilic group into the main chain or side chain of the polymer. A hydrophilic polymer such as polyvinyl alcohol or polyethylene glycol, a hydrophilic oligomer or a hydrophilic low molecular weight compound is adsorbed on the surface of the fine particle polymer to make the surface hydrophilic. As the fine particle polymer, a fine particle polymer having a thermally reactive functional group is more preferable. When the fine particle polymer as described above is dispersed in the (J) hydrophilic polymer matrix, the on-press development property is improved when the on-press development is performed, and the film strength of the heat-sensitive layer itself is further improved.
[0195]
Examples of the microcapsule type include a type described in JP-A No. 2000-118160 and a microcapsule type containing a compound having a thermally reactive functional group as described in JP-A No. 2001-277740. Preferably mentioned.
Examples of the sulfonic acid generating polymer used in the sulfonic acid generating polymer-containing type include, for example, a sulfonic acid ester group, a disulfone group, or a sec- or tert-sulfonamide group described in JP-A-10-282672 as a side chain. The polymer etc. which have are mentioned.
By including a hydrophilic resin in the untreated type heat-sensitive layer, not only the on-press developability is improved, but also the film strength of the heat-sensitive layer itself is improved. In addition, a lithographic printing plate precursor that does not require development processing can be obtained by crosslinking and curing the hydrophilic resin. Examples of the hydrophilic resin include those having a hydrophilic group such as hydroxy group, carboxy group, hydroxyethyl group, hydroxypropyl group, amino group, aminoethyl group, aminopropyl group, carboxymethyl group, and hydrophilic sol-gel conversion. A system binder resin is preferred. Specific examples of the hydrophilic resin include those listed as the hydrophilic resin used as the above-mentioned (J) hydrophilic polymer matrix.
Among these, a sol-gel conversion binder resin is preferable.
It is necessary to add a photothermal conversion substance to the untreated type heat-sensitive layer. The photothermal conversion substance may be any substance that absorbs light having a wavelength of 700 nm or more, and a dye similar to the dye used for the above-described thermal positive type is particularly preferable.
[0196]
<Back coat layer>
Thus, the image recording layer in the case where the lithographic printing plate is overlaid on the back surface of the lithographic printing plate precursor obtained by providing various image recording layers on the lithographic printing plate support, if necessary. In order to prevent scratching, a backcoat layer made of an organic polymer compound can be provided.
<Application method>
The photosensitive resin solution, the negative type laser image recording layer forming liquid, the body type laser image recording layer forming liquid, and the photopolymerization type laser image recording layer forming liquid are applied to the roughened surface of the lithographic printing plate support. As a method, 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 or the like can be used, and it can be carried out according to known conditions.
[0197]
An apparatus for drying the aluminum plate after coating the photosensitive resin solution, the negative type laser image recording layer forming liquid, the body type laser image recording layer forming liquid, and the photopolymerization type laser image recording layer forming liquid is disclosed in Japanese Patent Application Laid-Open No. Hei 6 (1994). -63487, an arch-type dryer that arranges a pass roll in a drying apparatus and dries while being conveyed by the pass roll, an air dryer that dries while the web is floated by supplying air from above and below the nozzle, There are a radiant heat dryer that dries with radiant heat from a heated medium, and a roller dryer that heats the roller and dries by conduction heat transfer by contact with the roller.
[0198]
[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, when the image recording layer is any one of a thermal type, a conventional type, and a photopolymer type, it is preferable to develop with a developer and obtain a lithographic printing plate after the exposure. 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.
[0199]
The lithographic printing plate thus obtained can achieve excellent printing durability, stain resistance and exposure stability in a high level with a good balance.
[0200]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these.
1. Preparation of aluminum plate
After chamfering the ingot of the alloy component having the composition shown in Table 1, homogenization treatment is performed, and then hot rolling, cold rolling, intermediate annealing, and cold rolling are sequentially performed, and the sheet thickness is 0.24 mm. Aluminum plates 1 to 26 were obtained. For the aluminum plates 1 to 26, the number per unit area of the intermetallic compound having an equivalent circle diameter of 1 μm or more existing on the surface of the aluminum plate, the equivalent circle diameter with respect to the number of intermetallic compounds existing on the surface of the aluminum plate is The ratio (abundance) of the number of intermetallic compounds having a size of 1 to 10 μm and the content of simple Si present in the aluminum plate were measured as follows.
The results are shown in Table 1. In the table, “-” indicates that the corresponding component is not contained.
[0201]
(1) The number of intermetallic compounds per unit area and the abundance ratio of intermetallic compounds having an equivalent circle diameter of 1 to 10 μm
A sample obtained by wiping off the oil on the surface of an aluminum plate with acetone was used as a measurement sample.
EPMA (manufactured by JEOL Ltd., JEOL SUPERPROBE JXA-8800M), acceleration voltage 20.0 kV, irradiation current 9.5 × 10^-9A composition image using a highly sensitive backscattered electron detector under the condition A was taken at a magnification of 500 times to obtain an instant photograph.
Next, after scanning the obtained reflection electrophotography (instant photograph), it is output to Photoshop 5.0 with gray scale (14 bits) and output resolution 75 dpi with the ScanScan CS-U attached and saved in TIF format. And converted into bmf (bitmap file) format using MS-Paint (manufactured by Microsoft).
This bmf format file is stored in the image analysis software ImageFactory Ver. 3.2 After reading into the Japanese version (Asahi Hitech Co., Ltd.) and performing image analysis, static binarization of the image is performed, and the portion corresponding to the white intermetallic compound is counted as a feature value. The particle size distribution was obtained by specifying the equivalent circle diameter (equivalent circle diameter).
From this result, the number of intermetallic compounds per unit area and the abundance of intermetallic compounds having an equivalent circle diameter of 1 to 10 μm were calculated.
[0202]
(2) Content of simple substance Si in aluminum plate
In a 1000 mL conical beaker, 250 mL of hydrochloric acid (hydrogen chloride: water = 1: 1) was taken, 10 g of an aluminum plate sample was weighed, and about 1 g was poured into hydrochloric acid and heated for decomposition. After most of the sample was decomposed, 1 mL of hydrogen peroxide (30 parts by mass) was added, water was added to make the liquid volume about 500 mL, and the sample was boiled for about 1 minute to completely decompose the sample.
After cooling in running water, the insoluble residue is suction filtered using a polycarbonate membrane filter (pore size 0.1 μm, filter size 47 mm), and the beaker, filter tube, filter and residue are thoroughly washed with distilled water, The residue was wrapped in one type of 5 A filter paper and placed in a platinum crucible, and the platinum crucible was heated with a burner to be incinerated.
After igniting at about 1000 ° C. for 30 minutes, the mixture was cooled to room temperature in a silica gel desiccator and the mass was measured. This operation was repeated until a constant weight was reached, and the mass before the hydrofluoric acid treatment was obtained.
After reaching constant weight, add a few drops of sulfuric acid (1 + 5) to moisten the oxide in the crucible, add about 20 mL of hydrofluoric acid (40% by mass), and gradually heat to dryness in a hot plate shape. And then ignited at about 1000 ° C. for 30 minutes. It cooled to room temperature in the silica gel desiccator, and measured the mass. This operation was repeated until the weight became constant, and the mass after the hydrofluoric acid treatment was obtained.
This total weight loss is silicon dioxide (SiO₂) Amount.
On the other hand, without using an aluminum plate sample, a blank test using the same amount of reagent as described above (blank) was performed, and as a blank test value, silicon dioxide (SiO 2₂) The amount was determined.
The content (mass%) of elemental Si in the aluminum plate was calculated by the following formula [1].
[0203]
Si content (mass%) = (W₁-W₂-W₃) X (0.4674 / W₀) X 100 [1]
[0204]
Where W₀Is the sample weighed (g), W₁Is the mass before hydrofluoric acid treatment (g), W₂Is the mass after hydrofluoric acid treatment (g), W₃Is a blank test value (g).
[0205]
As is apparent from Table 1, the aluminum plates 1 to 13 are all between the metals in which the contents of different elements contained therein, the number of intermetallic compounds per unit area, and the equivalent circle diameter are 1 to 10 μm. Although the compound abundance and the content of elemental Si were all within the scope of the present invention, at least one of these physical properties of the aluminum plates 14 to 26 was outside the scope of the present invention.
[0206]
[Table 1]

[0207]
[Table 2]

[0208]
2. Manufacture of lithographic printing plate support
Each of the aluminum plates 1 to 26 was subjected to any of the following surface treatments A to F to obtain lithographic printing plate supports.
The substrates obtained by subjecting the aluminum plates 1 to 26 to surface treatment A were designated as Examples 1-1 to 1-13 and Comparative examples 1-1 to 1-13, and the aluminum plates 1 to 13 were subjected to surface treatment B. The support obtained in Examples 2-1 to 2-13, and the support obtained by subjecting the aluminum plates 1 to 13 to surface treatment C are referred to as Comparative Examples 2-1 to 2-13, and the aluminum plates 1 to 13 are used. The support obtained by applying surface treatment D to Comparative Example 3-1 to 3-13, and the support obtained by subjecting aluminum plates 1 to 13 to surface treatment E as Comparative Examples 4-1 to 4-13 The supports obtained by subjecting the aluminum plates 1 to 13 to surface treatment F were referred to as Comparative Examples 5-1 to 5-13.
[0209]
(1) Surface treatment A
The surface treatment A was performed by continuously performing the following treatments (a) to (l). In addition, the water washing process was performed after the roughening process of each process. After the surface roughening treatment and the water washing treatment, the liquid was removed by a nip roller. Moreover, in the case where the process using the same kind of liquid is continuously performed, washing with water between the processes is omitted.
[0210]
<Mechanical roughening treatment (a)>
While supplying abrasive slurry (specific gravity 1.08) containing pumice with an average particle size of 12 μm as an abrasive to the surface of the aluminum plate with a spray tube, a mechanical roughening treatment is performed with a rotating nylon nylon brush. went.
The material of the bristle in the roller brush was 6 · 10 nylon. The brush bristles were planted so as to be dense by drilling holes in a stainless steel cylinder having a straight diameter of 300 mm. Three roller brushes were used. Each of the roller brushes was provided with two support rollers. The support roller had a diameter of 200 mm and a distance of 300 mm. The diameter of the bristle was 0.5 mm and the bristle length was 300 mm.
[0211]
The roller brush push-in amount is constant for the load of the drive motor rotating the roller brush relative to the load of the previous drive motor before pressing the roller brush, and after the roughening treatment The average surface roughness of the aluminum plate was controlled to be 0.4 to 0.5 μm. The oscillation amplitude was 100 mm.
[0212]
In the mechanical surface roughening treatment, the abrasive slurry is sampled at regular time intervals, the specific gravity is measured, and the abrasive is replenished so that the fluctuation range of the specific gravity is within ± 10%. Concentration was controlled.
[0213]
<Alkali etching treatment (b)>
An alkali solution (60 ° C.) containing 18% by mass of NaOH and 7.5% by mass of aluminum ions is sprayed from a spray tube onto the aluminum plate after the mechanical surface roughening treatment, and the amount of dissolved aluminum on the roughened surface is reduced. 8g / m²An alkali etching treatment was performed so that
For controlling the concentration of the alkali solution, the alkali solution supplied to the spray tube is sampled at regular time intervals, the specific gravity and the conductivity are measured, and the fluctuation range of the specific gravity and the conductivity is ± 10. The alkaline solution was supplemented with water or sodium hydroxide so as to be within%.
[0214]
<Desmutting treatment (c)>
The reaction was performed using an acidic solution having a liquid temperature of 30 ° C. and a nitric acid concentration of 1% by mass. The desmutting solution was sprayed with a spray and desmutted for 2 seconds.
[0215]
<Electrochemical surface roughening treatment (nitric acid electrolytic treatment) (d)>
2 was used in a nitric acid electrolyte in which aluminum nitrate was adjusted to 0.5 mass% by adding aluminum nitrate to a nitric acid aqueous solution having a liquid temperature of 40 ° C. and a nitric acid concentration of 1 mass%. An electrochemical roughening treatment was performed by applying a trapezoidal wave current having the waveform shown in FIG. The frequency of the trapezoidal wave current is 60 Hz, and the amount of electricity during the anode reaction of the aluminum plate is 220 C / dm.², And the current density is 25 A / dm at the peak of alternating current and the anode reaction of the aluminum plate²Met. The duty cycle (ta / T) of the alternating current was 0.5, and the rise times tp ′ and tp were 0.3 msec. The ratio Qc / Qa between the total amount of electricity Qa during the anode reaction and the total amount of electricity Qc during the cathode reaction of the aluminum plate at the portion facing the carbon main electrode was 0.95. The amount of electricity applied to the aluminum plate is the amount of electricity applied to the aluminum plate while the aluminum plate passes through the electrolytic cell, and is the sum of the amount of electricity subjected to the anode reaction of the aluminum plate.
[0216]
The nitric acid concentration of the nitric acid electrolyte is measured by measuring the sound speed and conductivity of the nitric acid electrolyte at regular time intervals, and concentrated nitric acid or water so that the fluctuation range of the sound speed and conductivity is within ± 10%. Was replenished and controlled.
[0217]
<Alkali etching treatment (e)>
An alkali solution (35 ° C.) containing 20% by mass of NaOH and 7.5% by mass of aluminum ions is sprayed from the spray tube onto the aluminum plate after the mechanical surface-roughening treatment. 0.9g / m²An alkali etching treatment was performed so that
[0218]
The concentration of sodium hydroxide in the alkali solution was controlled in the same manner as in the alkali etching treatment (b).
[0219]
<Desmutting treatment (f)>
Using an acidic solution having a liquid temperature of 40 ° C. and a sulfuric acid concentration of 15% by mass, spraying was performed by spraying for 2 seconds.
[0220]
<Electrochemical roughening treatment (hydrochloric acid electrolytic treatment) (g)>
In an aqueous hydrochloric acid solution having a liquid temperature of 30 ° C., a hydrochloric acid concentration of 0.2 mass%, and an aluminum ion concentration of 0.5 mass, an electrolysis cell shown in FIG. 2 is used to apply a trapezoidal wave current having the waveform shown in FIG. Chemical roughening treatment was performed. The frequency of the trapezoidal wave current is 60 Hz, and the amount of electricity at the time of the anode reaction of the aluminum plate is 30 C / dm.², And the current density is 25 A / dm at the peak of alternating current and the anode reaction of the aluminum plate²Met. The duty cycle (ta / T) of AC was 0.5, and the rise times tp ′ and tp were 0.5 msec. The ratio Qc / Qa between the total amount of electricity Qa during the anode reaction and the total amount of electricity Qc during the cathode reaction of the aluminum plate at the portion facing the carbon main electrode was 0.95. The amount of electricity applied to the aluminum plate is the amount of electricity applied to the aluminum plate while the aluminum plate passes through the electrolytic cell, and is the sum of the amount of electricity subjected to the anode reaction of the aluminum plate.
[0221]
The hydrochloric acid concentration of the hydrochloric acid electrolyte is determined by measuring the sound velocity and conductivity of the hydrochloric acid electrolyte at regular time intervals, and concentrated hydrochloric acid or water so that the fluctuation range of the sound velocity and conductivity is within ± 10%. Was replenished and controlled.
[0222]
<Alkali etching treatment (h)>
An aluminum solution having a NaOH concentration of 4% by mass (45 ° C.) is sprayed onto the aluminum plate after the mechanical surface roughening treatment, and the amount of aluminum dissolved on the roughened surface is 0.1 g / m.²An alkali etching treatment was performed so that
The concentration of sodium hydroxide in the alkaline solution was controlled in the same manner as in the alkali etching treatment (b).
[0223]
<Desmut treatment (i)>
Using an acidic solution having a liquid temperature of 30 ° C. and a sulfuric acid concentration of 10% by mass, spraying was performed by spraying, and desmut treatment was performed for 4 seconds.
[0224]
<Anodizing treatment (j)>
Anodization was performed by applying direct current in a sulfuric acid solution having a sulfuric acid concentration of 10 mass% and a liquid temperature of 30 ° C., and the surface coating amount was 2.6 g / m 2.²An anodized film was formed so that
In addition, the sulfuric acid solution used for the anodizing treatment was collected at regular intervals to measure the specific gravity and electrical conductivity, and concentrated sulfuric acid or water was replenished so that the fluctuation range of the specific gravity and electrical conductivity was within ± 10%. Thus, the sulfuric acid concentration of the sulfuric acid solution was controlled.
[0225]
<Sealing treatment (k)>
Steam sealing was performed for 10 seconds in a steam chamber saturated at 100 ° C. and 1 atm.
[0226]
<Hydrophilic treatment (l)>
It was soaked in a 1% by weight aqueous solution of sodium silicate at 40 ° C. for 7 seconds to perform a hydrophilic treatment. Then, it was dried.
[0227]
(2) Surface treatment B
Surface treatment B was performed in the same manner as surface treatment A except that the conditions were changed as follows in each treatment.
[0228]
<Alkali etching treatment (b)>
The NaOH concentration of the alkaline solution is 23% by mass, and the dissolution amount of the aluminum plate is 9 g / m.²It was.
<Desmutting treatment (c)>
The nitric acid concentration of the acidic solution was 0.8% by mass.
<Electrochemical surface roughening treatment (nitric acid electrolytic treatment) (d)>
The temperature of the nitric acid electrolyte is 45 ° C., and the current density is 30 A / dm.²The amount of electricity applied to the aluminum plate is 195 C / dm²It was.
<Alkali etching treatment (e)>
The NaOH concentration of the alkaline solution is 24% by mass, and the dissolution amount of the aluminum plate is 7.8 g / m.²It was.
<Electrochemical roughening treatment (hydrochloric acid electrolytic treatment) (g)>
The liquid temperature of the circular acid aqueous solution is 35 ° C., the hydrochloric acid concentration is 0.4 mass%, and the current density is 20 A / dm.²And the total amount of electricity is 26 C / dm²It was.
<Alkali etching treatment (h)>
0.001 g / m of dissolution amount of aluminum plate²It was.
[0229]
(3) Surface treatment C
Surface treatment C was performed in the same manner as surface treatment A except that the conditions were changed as follows in each treatment.
[0230]
<Mechanical roughening treatment (a)>
The average particle size of the pumice particles was 0.8 μm.
<Alkali etching treatment (b)>
The NaOH concentration of the alkaline solution was 25% by mass.
<Electrochemical roughening treatment (nitric acid electrolytic treatment) (d)>
Current density is 4 A / dm²The amount of electricity applied to the aluminum plate is 170 C / dm²It was.
<Alkali etching treatment (e)>
The dissolution amount of the aluminum plate is 0.2 g / m.²It was.
<Electrochemical roughening treatment (hydrochloric acid electrolytic treatment) (g)>
The hydrochloric acid concentration of the hydrochloric acid aqueous solution is 0.8 mass%, and the current density is 3 A / dm.²And the total amount of electricity is 50 C / dm²It was.
<Alkali etching treatment (h)>
The NaOH concentration of the alkaline solution is 9% by mass, and the dissolution amount of the aluminum plate is 0.01 g / m.²It was.
<Desmut treatment (i)>
The sulfuric acid concentration of the acidic solution was 30% by mass, and the liquid temperature was 60 ° C.
[0231]
(4) Surface treatment D
Surface treatment D was performed in the same manner as surface treatment A except that the conditions were changed as follows in each treatment.
[0232]
<Mechanical roughening treatment (a)>
The average particle size of the pumice particles was 0.8 μm.
<Alkali etching treatment (b)>
The NaOH concentration of the alkaline solution is 27% by mass, and the dissolution amount of the aluminum plate is 9 g / m.²It was.
<Electrochemical roughening treatment (nitric acid electrolytic treatment) (d)>
The nitric acid concentration in the aqueous nitric acid solution is 1.5% by mass, and the current density is 45 A / dm.²The amount of electricity applied to the aluminum plate is 200 C / dm²It was.
<Alkali etching treatment (e)>
The NaOH concentration of the alkaline solution is 15% by mass, and the dissolution amount of the aluminum plate is 2 g / m.²It was.
<Electrochemical roughening treatment (hydrochloric acid electrolytic treatment) (g)>
The hydrochloric acid concentration of the aqueous hydrochloric acid solution is 1.5 mass%, the aluminum ion concentration is 0.3 mass%, and the current density is 35 A / dm.²And the total amount of electricity is 5 C / dm²It was.
<Desmut treatment (i)>
The sulfuric acid concentration of the acidic solution was 15% by mass.
[0233]
(5) Surface treatment E
Surface treatment E was performed in the same manner as surface treatment A except that the conditions were changed as follows in each treatment.
[0234]
<Mechanical roughening treatment (a)>
The average particle size of the pumice particles was 75 μm.
<Alkali etching treatment (b)>
The NaOH concentration of the alkaline solution is 20% by mass, and the dissolution amount of the aluminum plate is 9 g / m.²It was.
<Electrochemical roughening treatment (nitric acid electrolytic treatment) (d)>
The nitric acid concentration of the nitric acid aqueous solution is 1.8% by mass, and the amount of electricity applied to the aluminum plate is 900 C / dm.²It was.
<Alkali etching treatment (e)>
Dissolving amount of aluminum plate is 2.5 g / m²It was.
<Electrochemical roughening treatment (hydrochloric acid electrolytic treatment) (g)>
The total amount of electricity is 15 C / dm²It was.
<Desmut treatment (i)>
The sulfuric acid concentration of the acidic solution was 15% by mass, and the liquid temperature was 50 ° C.
[0235]
(6) Surface treatment F
Surface treatment F was performed in the same manner as surface treatment A except that the conditions were changed as follows in each treatment.
[0236]
<Mechanical roughening treatment (a)>
The average particle size of the pumice particles was 75 μm.
<Alkali etching treatment (b)>
The NaOH concentration of the alkaline solution is 20% by mass, and the dissolution amount of the aluminum plate is 810 g / m.²It was.
<Electrochemical roughening treatment (nitric acid electrolytic treatment) (d)>
The amount of electricity applied to the aluminum plate is 200 C / dm²It was.
<Alkali etching treatment (e)>
The dissolution amount of the aluminum plate is 2 g / m.²It was.
<Electrochemical roughening treatment (hydrochloric acid electrolytic treatment) (g)>
The hydrochloric acid concentration in the aqueous hydrochloric acid solution is 0.9 mass%, the aluminum ion concentration is 0.7 mass%, and the total amount of electricity is 60 C / dm.²It was.
<Alkali etching treatment (h)>
The NaOH concentration of the alkaline solution is 5% by mass, and the dissolution amount of the aluminum plate is 0.9 g / m.²It was.
<Desmut treatment (i)>
The sulfuric acid concentration of the acidic solution was 15% by mass, and the liquid temperature was 60 ° C.
[0237]
3. Surface shape of lithographic printing plate support
Centerline average roughness R of the obtained lithographic printing plate support_aAnd maximum height R_maxWas measured as follows. The results for Examples 1-1 to 1-13 and Comparative Examples 1-1 to 1-13 are shown in Table 2.
[0238]
(1) Centerline average roughness R_a
Two-dimensional roughness measurement is performed with a stylus type roughness meter (for example, sufcom 575, manufactured by Tokyo Seimitsu Co., Ltd.), the average roughness defined in ISO 4287 is measured five times, and the average value is calculated as the centerline average roughness R._aIt was.
The conditions for the two-dimensional roughness measurement were a cut-off value of 0.8 mm, a tilt correction FLAT-ML, a measurement length of 3 mm, a vertical magnification of 10000 times, a scanning speed of 0.3 mm / sec, and a stylus tip diameter of 2 μm.
[0239]
(2) Maximum height R_max
Two-dimensional roughness measurement was performed with a stylus type roughness meter (for example, Surfcom 575, manufactured by Tokyo Seimitsu Co., Ltd.), and the measurement was performed according to JIS B0601-1994.
The conditions for the two-dimensional roughness measurement were a cut-off value of 0.8 mm, an evaluation length of 3.0 mm, a reference length of 3.0 mm, a scanning speed of 0.3 mm / sec, and a stylus diameter of 2 μm.
[0240]
The uniformity of pits in the production process (after nitric acid electrolysis and hydrochloric acid electrolysis) of the obtained lithographic printing plate support was evaluated by the following method. The results are shown in Table 2.
[0241]
(3) Uniformity of pits generated by nitric acid electrolysis (d)
After the electrochemical surface roughening treatment (nitric acid electrolysis treatment) (d), desmut treatment with a sulfuric acid solution, and using EMPA (JEOL SUPERPROBE JXA-8800M), an acceleration voltage of 20.0 kV, Irradiation current 9.5 × 10^-9A composition image was taken at a magnification of 1500 times using a highly sensitive backscattered electron detector under the conditions of A. The uniformity of the pits was visually evaluated from the obtained instant photographs.
A uniform pit is defined as "uniform", a non-uniform pit is defined as "non-uniform", the middle is defined as "slightly non-uniform", and the generated pit is dissolved as "pit dissolved" did.
[0242]
(4) Uniformity of pits produced by hydrochloric acid electrolysis (g)
After the electrochemical surface roughening treatment (hydrochloric acid electrolytic treatment) (g), pit uniformity was evaluated by the same method as in (3) above.
[0243]
4). Preparation of lithographic printing plate precursor
Image recording layers 1 and 2 were separately provided on each of the above lithographic printing plate supports to form a lithographic printing plate precursor. Each of the obtained lithographic printing plate precursors was subjected to an image forming process and a developing process described in the description of each image recording layer to obtain a lithographic printing plate.
[0244]
(1) Image recording layer 1
On the lithographic printing plate support, an undercoat solution having the following composition was applied and dried at 80 ° C. for 30 seconds to form an undercoat layer. The coating amount after drying is 30 mg / m²Met.
[0245]
<Undercoat liquid composition>
・ Aminoethylphosphonic acid 0.10g
・ Phenylphosphonic acid 0.15g
・ Β-Alanine 0.10g
・ Methanol 40g
・ Pure water 60g
[0246]
Next, a photosensitive layer coating solution having the following composition was prepared, and the coating amount after drying this photosensitive layer coating solution (photosensitive layer coating amount) on the undercoated lithographic printing plate support was 1.6 g / m.²And dried at 110 ° C. for 1 minute to form a photosensitive layer (conventional positive type image recording layer).
[0247]
<Photosensitive layer coating solution composition>
1. Esterified product of 1,2-diazonaphthoquinone-5-sulfonyl chloride and pyrogallol-acetone resin (described in Example 1 of US Pat. No. 3,635,709) 0.45 g
-Cresol-formaldehyde novolak resin (meta / para ratio = 6/4, weight average molecular weight 3,000, number average molecular weight 1,100, 0.7% by mass of unreacted cresol) 1.1 g
-M-cresol-formaldehyde novolak resin (weight average molecular weight 1,700, number average molecular weight 600, containing 1% by mass of unreacted cresol) 0.3 g
N- (p-aminosulfonylphenyl) acrylamide / normal butyl acrylate / diethylene glycol monomethyl ether methacrylate copolymer (monomer molar ratio = 40/40/20, weight average molecular weight 40,000, number average molecular weight 20,000) 0 .2g
-P-normal octylphenol-formaldehyde resin (described in US Pat. No. 4,123,279) 0.021 g
・ Naphthoquinone-1,2-diazide-4-sulfonic acid chloride 0.01 g
・ Tetrahydrophthalic anhydride 0.1g
・ Benzoic acid 0.02g
4- [p-N, N-bis (ethoxycarbonylmethyl) aminophenyl] -2,6-bis (trichloromethyl) -s-triazine 0.01 g
4- [p-N- (p-hydroxybenzoyl) aminophenyl] -2,6-bis (trichloromethyl) -s-triazine 0.02 g
-2-trichloromethyl-5- (4-hydroxystyryl) -1,3,4-oxadiazole 0.01 g
-Dye in which the counter anion of Victoria Pure Blue BOH is replaced with 1-naphthalenesulfonic acid 0.02 g
Fluorosurfactant (Modiper F-200, manufactured by NOF Corporation, 30% by mass of a mixed solvent solution of methyl ethyl ketone and methyl isobutyl ketone) 0.06 g
Fluorosurfactant (Megafac F-177, manufactured by Dainippon Ink and Chemicals, 20% by weight methyl isobutyl ketone solution) 0.02 g
・ Methyl ethyl ketone 15g
1-methoxy-2-propanol 10g
[0248]
Further, on the photosensitive layer formed in this manner, methyl methacrylate / ethyl acrylate / sodium acrylate (68/20 /) was formed based on the method described in Example 1 of JP-B 61-28986. 12) A mat layer was formed by electrostatic spraying an aqueous solution of the copolymer to obtain a photosensitive lithographic printing plate precursor.
[0249]
The lithographic printing plate precursor was exposed for 50 seconds with a 3 kw metal halide lamp from a distance of 1 m through a transparent positive film in a vacuum frame.
After that, as developer, SiO₂/ Na₂Fuji Photo Film charged with 5.26 mass% aqueous solution of sodium silicate (pH 12.7) with O = 1.74 (molar ratio) and FR-3 (1: 7) manufactured by Fuji Photo Film Co., Ltd. as a rinse solution Development processing was performed through an automatic processor Stablon 900D manufactured by KK and a lithographic printing plate was obtained.
[0250]
(2) Image recording layer 2
A photosensitive layer coating solution having the following composition was coated on a lithographic printing plate support to form a photosensitive layer. The coating amount after drying is 2 g / m²Met.
[0251]
<Photosensitive layer coating solution composition>
・ Esterified product of 1,2-diazonaphthoquinone-5-sulfonyl chloride and pyrogallol-acetone resin (weight average molecular weight 2,500) 40 parts by mass
-Phenol formaldehyde resin (weight average molecular weight 10,000, trinuclear component 90% by mass) 75 parts by mass
-Acrylic polymer (1) to be described later 35 parts by mass
2- (p-butoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine 3 parts by mass
・ Blue dye (oil blue # 603, manufactured by Orient Chemical Co., Ltd.) 1.5 parts by mass
-Fluorosurfactant (Megafac F-176, manufactured by Dainippon Ink & Chemicals, Inc.) 0.3 parts by mass
・ Methyl ethyl ketone 1000 parts by mass
・ Propylene glycol monomethyl ether 1000 parts by mass
[0252]
<Synthesis of acrylic polymer (1)>
60.3 g of N- (p-toluenesulfonyl) methacrylamide, 10.0 g of acrylonitrile and 46.0 g of ethyl acrylate were dissolved in 232.6 g of dimethylformamide, and 2,2′-azobis (2,4-dimethyl) was added under a nitrogen stream. (Valeronitrile) 0.224 g was used as a polymerization initiator and stirred at 65 ° C. for 7 hours. The reaction solution was allowed to cool and then reprecipitated in 5 L of water. The precipitated polymer was collected by filtration and dried to obtain 110.4 g of acrylic polymer (1) having a weight average molecular weight of 52,000 (yield 95%).
[0253]
On the photosensitive layer formed in this manner, a mat layer forming resin solution was sprayed, applied, and dried to form a mat layer, whereby a lithographic printing plate precursor was obtained.
As a resin solution for forming the mat layer, a 12% aqueous solution in which a part of a copolymer of methyl methacrylate / ethyl acrylate / acrylic acid (charged mass ratio 65/20/15) was a sodium salt was used.
For spray coating, using a rotary atomizing electrostatic coater, the number of atomization head rotations is 25,000 rpm, the amount of resin liquid is 40 mL / min, the voltage applied to the atomization head is -90 kV, and the ambient temperature is 25. It carried out on the conditions of (degreeC) and relative humidity 50%.
Drying was performed by spraying steam onto the coated surface 2.5 seconds after spray coating and then spraying dry air with a temperature of 60 ° C. and 10% humidity for 5 seconds 3 seconds after spraying the steam.
[0254]
The planographic printing plate precursor was exposed through a document film for 60 seconds with a 3 kW metal halide lamp from a distance of 1 m.
Thereafter, the film was developed through a commercially available automatic processor PS-900D (manufactured by Fuji Photo Film Co., Ltd.) having an immersion type developing tank to obtain a lithographic printing plate. Here, the first bath of the developing tank of the automatic processor is charged with 20 L of a developer (pH about 12.4) having the following composition and kept at 30 ° C., and the second bath is charged with 8 L of tap water. The bath was charged with 8 L of a finishing dilute solution (finishing gum solution / water = 1/1) having the following composition and used for the development process.
[0255]
<Developer composition>
・ D-sucrose 4.8% by mass
・ Sodium hydroxide 0.34% by mass
・ Sodium carbonate 0.70% by mass
・ Tetrabutylammonium bromide 0.03 mass%
・ Water 94.13% by mass
[0256]
<Development replenisher (pH of about 13.0) composition>
・ D-sucrose 9.7% by mass
・ Sodium hydroxide 1.5% by mass
・ Sodium carbonate 1.0% by mass
・ Tetrabutylammonium bromide 0.07% by mass
・ Water 87.73 mass%
[0257]
<Finishing gum solution composition>
・ Gum arabic 1.8% by mass
・ Enzyme-modified potato starch: 18.3% by mass
・ Enzyme-modified onion starch 3.7% by mass
・ Phosphorylated waxy onion starch 1.8% by mass
・ Dioctylsulfosuccinate sodium salt 0.91% by mass
・ Primary ammonium phosphate 0.27% by mass
・ Phosphoric acid (85% by mass) 0.37% by mass
・ EDTA-tetrasodium salt 0.27% by mass
・ Ethylene glycol 1.8% by mass
・ Benzyl alcohol 2.3% by mass
-Sodium dehydroacetate 0.04% by mass
・ Emulsion type silicone antifoaming agent 0.02% by mass
・ Water 68.42% by mass
[0258]
<Rinse solution>
・ Sodium dodecyl diphenyl ether disulfonate (40% by mass aqueous solution) 6.7% by mass
・ Sodium hexametaphosphate 0.8% by mass
・ Benzyl alcohol 1.5% by mass
・ Polyoxyethylene (12 mol addition of ethylene oxide) nonylphenyl ether 1.5% by mass
-Sodium dioctyl sulfosuccinate 1.4% by mass
・ Phosphoric acid (85% by mass) 5.2% by mass
・ Sodium hydroxide 2.0% by mass
・ Silicon defoamer 0.01% by mass
・ Water: 80.89% by mass
[0259]
5). Evaluation of planographic printing plates
Each lithographic printing plate obtained from each lithographic printing plate precursor was evaluated as follows. The results for Examples 1-1 to 1-13 and Comparative Examples 1-1 to 1-13 are shown in Table 2. In Table 2, the same support was evaluated comprehensively using a planographic printing plate having each of the image recording layers 1 and 2.
[0260]
(1) Printing durability
Printing with Komori Corporation Lithron printing machine using DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc., when it is visually recognized that the density of the solid image has started to fade Printing durability was evaluated by the number of sheets.
The evaluation was performed by relative evaluation of the number of printed sheets, and “Excellent”, “Good”, “Slightly bad”, and “Bad” were set in descending order.
[0261]
(2) Normal stain resistance
Print with DIC-GEOS (s) red ink on a Mitsubishi diamond F2 printer (Mitsubishi Heavy Industries, Ltd.) evaluated.
In order from the one without dirt, “Excellent”, “Good”, “Slightly bad”, and “Evil” were set.
[0262]
(3) Severe ink stain resistance
Printing was performed using a fountain solution to which Cl ions were added, and the stain on the non-image area that occurred when left on the printing machine at least once was visually observed to evaluate the resistance to severe ink stains.
In order from the least dirty, “good”, “slightly bad”, and “bad”.
[0263]
(4) Pot-like stain resistance
The non-image portion of the lithographic printing plate was observed with an optical microscope at a magnification of 100 times to examine the presence or absence of a pot-like residual film in an area of 1 mm square. In addition, printing similar to the above (1) printing durability was performed, and small spot-like stains (pot-like stains) generated on the non-image portion of the printed material when 500 sheets were printed were observed. From these, pot-like soil resistance was evaluated.
“No good” indicates that no spot-like residual film is observed and there is no spot-like dirt and no problem in practical use, and “Poor” means that the spot-like residual film is observed and causes spot-like dirt in practical use. evaluated.
[0264]
(5) Water width
Decreasing the amount of fountain solution stepwise, printing is performed in the same manner as (1) printing durability, and ink begins to adhere between the halftone dots with respect to halftone dots with an area ratio of 50%. The water width was evaluated based on the amount of dampening water.
“Good”, “slightly bad”, and “bad” were set in order from the one with the least amount of dampening water when ink started to adhere.
[0265]
(6) Hard to entangle ink
With SOR-M printing machine manufactured by Komori Corporation, DIC-GEOS (H) ink manufactured by Dainippon Ink & Chemicals, Inc. is used to perform printing with less dampening water, and ink entanglement at halftone dots Evaluation was made.
The order of “good”, “slightly bad”, and “bad” was given in the order in which no ink entanglement was observed.
[0266]
[Table 3]

[0267]
[Table 4]

[0268]
The lithographic printing plate supports of Examples 1-1 to 1-13 and 2-1 to 2-13 have a centerline average roughness R_aIs 0.35μm or more and the maximum height R_maxHas a surface of 8.0 μm or less, uniform pits, printing durability and stain resistance when used as a lithographic printing plate (normal stain resistance, severe ink stain resistance, water width and ink entanglement) ) And exposure stability (pot-like stain resistance) were realized at a high level and in a well-balanced manner. Among them, the lithographic printing plate supports of Examples 1-1 to 1-13 are excellent in printing durability. In particular, the lithographic printing plate supports of Examples 1-10 to 1-13 are printing resistant. And excellent soil resistance.
[0269]
On the other hand, the lithographic printing plate supports of Comparative Examples 1-1 to 1-13 were inferior in printing durability because they did not satisfy the physical properties of the aluminum plate. The lithographic printing plate supports of Comparative Examples 2-1 to 2-13 and 3-1 to 3-13 are all centerline average roughness R._aWas 0.34 μm or less, and was inferior in water width and ink entanglement. Comparative Examples 4-1 to 4-13 and 5-1 to 5-13 are all centerline average roughness R_aWas 0.35 μm or more, but the maximum height R_maxWas over 8.0 μm, and it was inferior in pot-like stain resistance.
[0270]
【The invention's effect】
The lithographic printing plate precursor of the present invention using the lithographic printing plate support of the present invention can achieve a good balance of printing durability, stain resistance and exposure stability when used as a lithographic printing plate. .
The method for producing a lithographic printing plate support of the present invention is suitable as a method for producing the lithographic printing plate support of the present invention.
[Brief description of the drawings]
FIG. 1 is a waveform diagram showing a waveform of a trapezoidal wave current applied in electrochemical roughening treatments (d) and (g) in an example.
FIG. 2 is a cross-sectional view schematically showing the configuration of an electrolytic cell used in electrochemical roughening treatments (d) and (g) in Examples.
FIG. 3 is a cross-sectional view schematically showing an example of an interface between a conventional lithographic printing plate precursor support and an image recording layer. (A) shows before exposure, (b) shows during exposure, and (c) shows after exposure.
FIG. 4 is a cross-sectional view schematically showing another example of the interface between the support of the conventional lithographic printing plate precursor and the image recording layer. (A) shows before exposure, (b) shows during exposure, and (c) shows after exposure.
[Explanation of symbols]
10 Planographic printing plate precursor
12 Support for lithographic printing plate
14 Image recording layer
40 Electrolyzer
42 Electrolyzer body
42A opening
44 Feed roller
46A, 46B main pole
48A, 48B Liquid supply nozzle
50A downstream guide roller
50B upstream guide roller
52 overflow tank
54 Auxiliary electrolytic cell
54A bottom
56 Auxiliary electrode
104 radial electrolytic cell
AC AC power supply
P pit
P 'uneven pit
Th1, Th2 Thyristor
W Aluminum web

Claims (1)

A lithographic printing plate support having a surface having _a center line average roughness _Ra of 0.35 μm or more and a maximum height R _{max of} 8.0 μm or less, obtained by subjecting an aluminum plate to roughening treatment and anodizing treatment Body,
The aluminum plate is
Fe content is 0.15-0.5 mass%, Si content is 0.03-0.15 mass%, Cu content is 0.0001-0.030 mass%, Ti content is 0.0010. 0.04 mass%, Pb content is 0.0001-0.0030 mass%, Ni content is 0.0002-0.005 mass%, the balance consists of Al and inevitable impurities,
About the intermetallic compound consisting of two or more of these metal elements present on the surface of the aluminum plate, the intermetallic compound having an equivalent circle diameter of 1 μm or more is 7000 pieces / mm ² or less, and the equivalent circle diameter The ratio of the intermetallic compound in which is 1 to 10 μm is 85% or more,
A support for a lithographic printing plate, which is an aluminum plate in which elemental Si present in the aluminum plate is 0.010% by mass or less.

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