JP2004148798A - Supporting body for lithographic printing plate, and original plate of lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supporting body for a lithographic printing plate used for the original plate of the lithographic printing plate, of which printing durability and fouling resistance become excellent when being made into a lithographic printing plate, and also, by which inking on a solid part is hard to occur when a coated reproduced paper is used. <P>SOLUTION: The surface area ratio ΔS<SP>50</SP>obtained by a following equation (1) with an actual area S<SB>x</SB><SP>50</SP>obtained by the approximation three-point method from three-dimensional data obtained by measuring (50μm)<SP>2</SP>of the surface at 512x512 points by using an atomic force microscope, and a geometrically measured area S<SB>O</SB><SP>50</SP>is 30 to 60%. Also, the steepness a45<SP>50(0.2-2)</SP>which is an area ratio of a part with an inclination of 45° or higher in data obtained by extracting components from a wavelength 0.2μm to 2 μm from the three-dimensional data is 5 to 40% for this supporting body for a lithographic printing plate. The equation (1) is shown by ΔS<SP>50</SP>=(S<SB>x</SB><SP>50</SP>-S<SB>O</SB><SP>50</SP>)/S<SB>O</SB><SP>50</SP>x100(%). <P>COPYRIGHT: (C)2004,JPO

Description

【０１３６】
＜表面処理＞
アルミニウム板に、以下の（ａ）〜（ｋ）の各種表面処理を第２表に示す組み合わせで連続的に行い、実施例１〜８および比較例１〜５の平版印刷版用支持体を得た。各処理および水洗の後にはニップローラで液切りを行った。
なお、第２表中、「−」は該当する表面処理を行わなかったことを表す。
【０１３７】
【表２】

【０１３８】
以下、各表面処理（ａ）〜（ｋ）を説明する。
（ａ）機械的粗面化処理（ブラシグレイン法）
図１に模式的に示したような装置を使って、研磨剤（パミス）の水懸濁液（比重１．１ｇ／ｃｍ^３ ）を研磨スラリー液とし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。図１において、１はアルミニウム板、２および４はローラ状ブラシ（本実施例において、束植ブラシ）、３は研磨スラリー液、５、６、７および８は支持ローラである。機械的粗面化処理は、第３表に示す条件Ｂ−１およびＢ−２のいずれかで行った。
研磨剤のメジアン径は第３表に示したとおりであった。ナイロンブラシの材質は６・１０ナイロン、毛長は５０ｍｍ、毛の直径は０．３ｍｍであった。ナイロンブラシはφ４００ｍｍ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。回転ブラシは図１には２本しか示されていないが、実際には第３表に示す数で使用した。ブラシ下部の２本の支持ローラ（φ２００ｍｍ）の距離は３００ｍｍであった。ブラシローラはブラシを回転させる駆動モータの負荷が、ブラシローラをアルミニウム板に押さえつける前の負荷に対して１０ｋＷプラスになるまで押さえつけた。ブラシの回転方向はアルミニウム板の移動方向と同じであった。ブラシの回転数は第３表に示したとおりであった。なお、第３表におけるブラシの回転数は、アルミニウム板の搬送方向上流側から順に、ブラシを１本目、２本目、３本目として表した。
【０１３９】
【表３】

【０１４０】
（ｂ）アルカリエッチング処理
アルカリエッチング処理は、第４表に示す条件Ｅ−１〜Ｅ−８のいずれかで行った。
具体的には、第４表に示すカセイソーダ濃度およびアルミニウムイオン濃度のカセイソーダ水溶液を用いスプレーにより、第４表に示すアルミニウム溶解量でエッチング処理を行った。その後、スプレーによる水洗を行った。なお、アルカリエッチング処理の温度は、７０℃であった。
【０１４１】
【表４】

【０１４２】
（ｃ）デスマット処理
デスマット処理は、第５表に示す条件Ｄ−１〜Ｄ−３のいずれかで行った。
具体的には、第５表に示す種類の酸、温度および濃度の酸水溶液で、スプレーによるデスマット処理を行い、その後、スプレーによる水洗を行った。なお、条件Ｄ−１に用いた硝酸水溶液としては、硝酸水溶液中で交流を用いて電気化学的粗面化処理を行う工程の廃液を用いた。
【０１４３】
【表５】

【０１４４】
（ｄ）電気化学的粗面化処理
電気化学的粗面化処理は、第６表に示す条件Ｃ−１〜Ｃ−３および第７表に示す条件Ｍ−１〜Ｍ−３のいずれかで行った。具体的には、以下のようにして行った。
（ｄ−１）硝酸電解（条件Ｃ−１〜Ｃ−３）
６０Ｈｚの交流電圧を用いて連続的に電気化学的な粗面化処理を行った。このときの電解液は、硝酸１質量％水溶液（アルミニウムイオンを０．５質量％含む。）、液温５０℃であった。交流電源波形は図２に示した波形であり、電流値がゼロからピークに達するまでの時間ＴＰが０．８ｍｓｅｃ、ｄｕｔｙ比１：１、台形の矩形波交流を用いて、カーボン電極を対極として電気化学的な粗面化処理を行った。補助アノードにはフェライトを用いた。電解槽は図３に示すものを使用した。
電流密度は電流のピーク値で３０Ａ／ｄｍ^２ 、補助陽極には電源から流れる電流の５％を分流させた。硝酸電解における電気量はアルミニウム板が陽極時の電気量の総和で第６表に示す値とした。
その後、スプレーによる水洗を行った。
【０１４５】
【表６】

【０１４６】
（ｄ−２）塩酸電解（条件Ｍ−１〜Ｍ−３）
６０Ｈｚの交流電圧を用いて連続的に電気化学的な粗面化処理を行った。液温５０℃であった。交流電源波形は図２に示した波形であり、電流値がゼロからピークに達するまでの時間ＴＰが０．８ｍｓｅｃ、ｄｕｔｙ比１：１、台形の矩形波交流を用いて、カーボン電極を対極として電気化学的な粗面化処理を行った。補助アノードにはフェライトを用いた。電解槽は図３に示すものを使用した。
電流密度は電流のピーク値で２５Ａ／ｄｍ^２ であった。
塩酸電解に用いた電解液は第７表に示す塩酸濃度の水溶液（アルミニウムイオンを０．５質量％含む。）であり、塩酸電解における電気量はアルミニウム板が陽極時の電気量の総和で第７表に示す値とした。
その後、スプレーによる水洗を行った。
【０１４７】
【表７】

【０１４８】
（ｅ）アルカリエッチング処理
アルカリエッチング処理は、第４表に示す条件Ｅ−１〜Ｅ−８のいずれかで行った。その後、スプレーによる水洗を行った。
【０１４９】
（ｆ）デスマット処理
デスマット処理は、第５表に示す条件Ｄ−１〜Ｄ−３のいずれかで行った。その後、スプレーによる水洗を行った。
【０１５０】
（ｇ）電気化学的粗面化処理
電気化学的粗面化処理は、第６表に示す条件Ｃ−１〜Ｃ−３および第７表に示す条件Ｍ−１〜Ｍ−３のいずれかで行った。その後、スプレーによる水洗を行った。
【０１５１】
（ｈ）アルカリエッチング処理
アルカリエッチング処理は、第４表に示す条件Ｅ−１〜Ｅ−８のいずれかで行った。その後、スプレーによる水洗を行った。
【０１５２】
（ｉ）デスマット処理
デスマット処理は、第５表に示す条件Ｄ−１〜Ｄ−３のいずれかで行った。その後、スプレーによる水洗を行った。
【０１５３】
（ｊ）陽極酸化処理
陽極酸化処理は、下記の条件Ａ−１により行った。
＜条件Ａ−１＞
図４に示す構造の直流電解による陽極酸化装置を用いて陽極酸化処理を行い、平版印刷版用支持体を得た。第一および第二電解部に供給した電解液としては、硫酸を用いた。電解液は、いずれも、硫酸濃度１５質量％（アルミニウムイオンを０．５質量％含む。）、温度３８℃であった。その後、スプレーによる水洗を行った。最終的な酸化皮膜量は２．５ｇ／ｍ^２ であった。
【０１５４】
（ｋ）シリケート処理
シリケート処理は、下記の条件Ｓ−１により行った。
＜条件Ｓ−１＞
３５℃の３号ケイ酸ソーダ水溶液（Ｎａ_２ Ｏ：ＳｉＯ_２ ＝１：３、ＳｉＯ_２ 含有量３０質量％、日本化学工業社製、濃度１質量％）に１０秒間浸せきさせた。その後、井水を用いたスプレーによる水洗を行った。
【０１５５】
２．平版印刷版用支持体の表面形状のファクターの算出
上記で得られた平版印刷版用支持体の表面について、以下のようにしてΔＳ^５０、ａ４５^{５０（０．２−２）} 、ΔＳ^{５（０．０２−０．２）} およびａ４５^{５（０．０２−０．２）} を求めた。
結果を第８表に示す。
【０１５６】
（１）原子間力顕微鏡による表面形状の測定
ΔＳ^５０、ａ４５^{５０（０．２−２）} 、ΔＳ^{５（０．０２−０．２）} およびａ４５^{５（０．０２−０．２）} を求めるために、原子間力顕微鏡（ＳＰＡ３００／ＳＰＩ３８００Ｎ、セイコーインスツルメンツ社製）により表面形状を測定し、３次元データを求めた。
平版印刷版用支持体を１ｃｍ角の大きさに切り取って、ピエゾスキャナー上の水平な試料台にセットし、カンチレバーを試料表面にアプローチし、原子間力が働く領域に達したところで、ＸＹ方向にスキャンし、その際、試料の凹凸をＺ方向のピエゾの変位でとらえた。ピエゾスキャナーは、ＸＹ方向について１５０μｍ、Ｚ方向について１０μｍ、走査可能なものを使用した。カンチレバーは共振周波数１２０〜４００ｋＨｚ、バネ定数１２〜９０Ｎ／ｍのもの（ＳＩ−ＤＦ２０、セイコーインスツルメンツ社製）を用い、ＤＦＭモード（Ｄｙｎａｍｉｃ Ｆｏｒｃｅ Ｍｏｄｅ）で測定した。また、求めた３次元データを最小二乗近似することにより試料のわずかな傾きを補正し基準面を求めた。
計測の際は、ΔＳ^５０およびａ４５^{５０（０．２−２）} については、表面の５０μｍ□を５１２×５１２点測定した。ＸＹ方向の分解能は０．１μｍ、Ｚ方向の分解能は０．１５ｎｍ、スキャン速度は５０μｍ／ｓｅｃとした。
また、ΔＳ^{５（０．０２−０．２）} およびａ４５^{５（０．０２−０．２）} については、表面の５μｍ□を５１２×５１２点測定した。ＸＹ方向の分解能は０．０１μｍ、Ｚ方向の分解能は０．１５ｎｍ、スキャン速度は５μｍ／ｓｅｃとした。
【０１５７】
（２）３次元データの補正
ΔＳ^５０の算出には、上記（１）で求められた表面の５０μｍ□の測定に基づく３次元データをそのまま用いた。
ａ４５^{５０（０．２−２）} の算出には、上記（１）で求められた表面の５０μｍ□の測定に基づく３次元データから波長０．２μｍ以上２μｍ以下の成分を抽出したものを用いた。波長０．２μｍ以上２μｍ以下の成分の抽出は、上記（１）で求められた３次元データを高速フーリエ変換をして周波数分布を求め、ついで、波長０．２μｍ未満の成分および波長２μｍを超える成分を除去した後、フーリエ逆変換をすることにより行った。
また、ΔＳ^{５（０．０２−０．２）} およびａ４５^{５（０．０２−０．２）} の算出には、上記（１）で求められた表面の５μｍ□の測定に基づく３次元データから波長０．０２μｍ以上０．２μｍ以下の成分を抽出したものを用いた。波長０．０２μｍ以上０．２μｍ以下の成分の抽出は、上記（１）で求められた３次元データを高速フーリエ変換をして周波数分布を求め、ついで、波長０．０２μｍ未満の成分および波長０．２μｍを超える成分を除去した後、フーリエ逆変換をすることにより行った。
【０１５８】
（３）各ファクターの算出
▲１▼ΔＳ^５０
上記（１）で求められた３次元データ（ｆ（ｘ，ｙ））を用い、隣り合う３点を抽出し、その３点で形成される微小三角形の面積の総和を求め、実面積Ｓ_ｘ ^５０とした。表面積比ΔＳ^５０は、得られた実面積Ｓ_ｘ ^５０と幾何学的測定面積Ｓ_０ ^５０ とから、上記式（１）により求めた。
【０１５９】
▲２▼ａ４５^{５０（０．２−２）}
上記（２）で補正して得られた３次元データ（ｆ（ｘ，ｙ））を用い、各基準点と所定の方向（例えば、右と下）の隣接する２点との３点で形成される微小三角形と基準面とのなす角を各基準点について算出した。微小三角形の傾斜度が４５度以上の基準点の個数を、全基準点の個数（全データの個数である５１２×５１２点から所定の方向の隣接する２点がない点の個数を減じた個数、即ち、５１１×５１１点）で除して、傾斜度４５度以上の部分の面積率ａ４５^{５０（０．２−２）} を算出した。
【０１６０】
▲３▼ΔＳ^{５（０．０２−０．２）}
上記（２）で補正して得られた３次元データ（ｆ（ｘ，ｙ））を用い、隣り合う３点を抽出し、その３点で形成される微小三角形の面積の総和を求め、実面積Ｓ_ｘ ^{５（０．０２−０．２）} とした。表面積比ΔＳ^{５（０．０２−０．２）} は、得られた実面積Ｓ_ｘ ^{５ （０．０２−０．２）}と幾何学的測定面積Ｓ_０ ^５とから、上記式（２）により求めた。
【０１６１】
▲４▼ａ４５^{５（０．０２−０．２）}
上記（２）で補正して得られた３次元データ（ｆ（ｘ，ｙ））を用い、各基準点と所定の方向（例えば、右と下）の隣接する２点との３点で形成される微小三角形と基準面とのなす角を各基準点について算出した。微小三角形の傾斜度が４５度以上の基準点の個数を、全基準点の個数（全データの個数である５１２×５１２点から所定の方向の隣接する２点がない点の個数を減じた個数、即ち、５１１×５１１点）で除して、傾斜度４５度以上の部分の面積率ａ４５^{５（０．０２−０．２）} を算出した。
【０１６２】
また、表面に存在する深さ４μｍ以上の局所的深部の個数は、レーザ顕微鏡（Ｍｉｃｒｏｍａｐ５２０、（株）菱化システム製）を用いて表面の４００μｍ×４００μｍを非接触で分解能０．０１μｍで走査して３次元データを求め、この３次元データにおいて深さ４μｍ以上の凹部の数を数えた。測定は１サンプルにつき５箇所測定し、その平均値を求めた。
なお、レーザ顕微鏡としては、上記で用いたもののほか、例えば、（株）ＫＥＹＥＮＣＥ製の超深度形状測定顕微鏡ＶＫ５８００も同様に用いることができる。
【０１６３】
３．平版印刷版原版の作成
上記で得られた各平版印刷版用支持体に、以下のようにしてサーマルポジタイプの画像記録層ＡおよびＢのいずれかを設けて平版印刷版原版を得た。なお、画像記録層ＡおよびＢを設ける前には、後述するように下塗層を設けた。
【０１６４】
＜下塗層の形成＞
シリケート処理後の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１５秒間乾燥し、下塗層の塗膜を形成させた。乾燥後の塗膜の被覆量は１０ｍｇ／ｍ^２ であった。
【０１６５】
＜下塗液組成＞
・下記高分子化合物 ０．２ｇ
・メタノール １００ｇ
・水 １ｇ
【０１６６】
【化１】

【０１６７】
＜画像記録層Ａの形成＞
画像記録層Ａは、単層型のサーマルポジタイプの画像記録層であり、以下のようにして形成させた。
下記組成の感熱層塗布液を調製し、下塗層を設けた平版印刷版用支持体に、この感熱層塗布液を乾燥後の塗布量（感熱層塗布量）が１．７ｇ／ｍ^２ になるよう塗布し、乾燥させて感熱層（単層型のサーマルポジタイプの画像記録層）を形成させ、平版印刷版原版を得た。
【０１６８】
＜感熱層塗布液組成＞
・ノボラック樹脂（ｍ−クレゾール／ｐ−クレゾール＝６０／４０、重量平均分子量７，０００、未反応クレゾール０．５質量％含有） １．０ｇ
・下記構造式で表されるシアニン染料Ａ ０．１ｇ
・テトラヒドロ無水フタル酸 ０．０５ｇ
・ｐ−トルエンスルホン酸 ０．００２ｇ
・エチルバイオレットの対イオンを６−ヒドロキシ−β−ナフタレンスルホン酸にしたもの ０．０２ｇ
・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） ０．０５ｇ
・メチルエチルケトン １２ｇ
【０１６９】
【化２】

【０１７０】
＜画像記録層Ｂの形成＞
画像記録層Ｂは、重層型のサーマルポジタイプの画像記録層であり、以下のようにして形成させた。
下記組成の第一層用塗布液を調製し、下塗層を形成させた平版印刷版用支持体に、この第一層用塗布液を乾燥後の塗布量が０．８５ｇ／ｍ^２ になるよう塗布し、ＴＡＢＡＩ社製、ＰＥＲＦＥＣＴ ＯＶＥＮ ＰＨ２００を用いてＷｉｎｄ Ｃｏｎｔｒｏｌを７に設定して、１４０℃で５０秒間乾燥させて第一層を形成させた。ついで、下記組成の第二層用塗布液を調製し、第一層を形成させた平版印刷版用支持体に、この第二層用塗布液を乾燥後の塗布量が０．１５ｇ／ｍ^２ になるよう塗布し、１２０℃で６０秒間乾燥させて第二層を形成させ、重層型のサーマルポジタイプの画像記録層を有する平版印刷版原版を得た。
【０１７１】
＜第一層用塗布液組成＞
・Ｎ−（４−アミノスルホニルフェニル）メタクリルアミド／アクリロニトリル／メタクリル酸メチル（モル比３６／３４／３０、重量平均分子量５０，０００、酸価２．６５） ２．１３３ｇ
・上記式で表されるシアニン染料Ａ ０．１０９ｇ
・４，４′−ビスヒドロキシフェニルスルホン ０．１２６ｇ
・無水テトラヒドロフタル酸 ０．１９０ｇ
・ｐ−トルエンスルホン酸 ０．００８ｇ
・３−メトキシ−４−ジアゾジフェニルアミンヘキサフルオロホスフェート ０．０３０ｇ
・エチルバイオレットの対イオンを６−ヒドロキシナフタレンスルホンに変えたもの ０．１０ｇ
・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、２０質量％溶液、塗布面状改良用） ０．０３５ｇ（溶液として）
・メチルエチルケトン ２５．３８ｇ
・１−メトキシ−２−プロパノール １３．０ｇ
・γ−ブチロラクトン １３．２ｇ
【０１７２】
＜第二層用塗布液組成＞
・ｍ，ｐ−クレゾール−ノボラック樹脂（ｍ／ｐ比＝６／４、重量平均分子量４，５００、未反応クレゾール０．８質量％含有） ０．２８４６ｇ
・上記式で表されるシアニン染料Ａ ０．０７５ｇ
・ベヘン酸アミド ０．０６０ｇ
・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、２０質量％溶液、塗布面状改良用） ０．０２２ｇ（溶液として）
・フッ素系界面活性剤（メガファックＭＣＦ−３１２、大日本インキ化学工業社製、３０質量％溶液、画像形成改良用） ０．１２０ｇ（溶液として）
・メチルエチルケトン １５．１ｇ
・１−メトキシ−２−プロパノール ７．７ｇ
【０１７３】
４．露光および現像処理
上記で得られた各平版印刷版原版には、下記の方法で画像露光および現像処理を行い、平版印刷版を得た。
【０１７４】
平版印刷版原版を出力５００ｍＷ、波長８３０ｎｍビーム径１７μｍ（１／ｅ^２ ）の半導体レーザーを装備したＣＲＥＯ社製ＴｒｅｎｎｄＳｅｔｔｅｒ３２４４を用いて主走査速度５ｍ／秒、版面エネルギー量１４０ｍＪ／ｃｍ^２ で像様露光した。なお、後述するポツ状残膜の評価のためには、版面エネルギー量を２０〜１４０ｍＪ／ｃｍ^２ まで２０ｍＪ／ｃｍ^２ おきに変えて露光を行ったサンプルを準備した。
その後、非還元糖と塩基とを組み合わせたＤ−ソルビット／酸化カリウムＫ_２ Ｏよりなるカリウム塩５．０質量％およびオルフィンＡＫ−０２（日信化学社製）０．０１５質量％を含有する水溶液１ＬにＣ_１２Ｈ_２５Ｎ（ＣＨ_２ ＣＨ_２ ＣＯＯＮａ）_２ １．０ｇを添加したアルカリ現像液（現像液１）を用いて現像処理を行った。現像処理は、現像液１を満たした自動現像機ＰＳ９００ＮＰ（富士写真フイルム（株）製）を用いて、現像温度２５℃、１２秒の条件で行った。現像処理が終了した後、水洗工程を経て、ガム（ＧＵ−７（１：１））等で処理して、製版が完了した平版印刷版を得た。
【０１７５】
５．平版印刷版の評価
上記で得られた平版印刷版の耐刷性、クリーナ耐刷性、耐汚れ性、ベタ部の着肉性およびポツ状残膜の発生の有無を下記の方法で評価した。
（１）耐刷性
小森コーポレーション社製のＳＰＲＩＮＴ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。
結果を第９表に示す。なお、耐刷性は、実施例６の耐刷性を１００とした相対値で示した。
【０１７６】
（２）クリーナ耐刷性
耐刷性の評価の場合と同様の条件で印刷を行い、ベタ画像部をスポンジを用い、プレートクリーナ液（マルチクリーナ、富士写真フイルム（株）製）により、５０００枚印刷する毎に洗浄し、ベタ画像部が薄くかすれ始めたことが目視で認められるまでの印刷枚数により、評価した。
結果を第９表に示す。なお、クリーナ耐刷性は、実施例６のクリーナ耐刷性を１００とした相対値で示した。
【０１７７】
（３）耐汚れ性（地汚れ）
三菱ダイヤ型Ｆ２印刷機（三菱重工業社製）で、レオエコー紫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（地汚れ）を目視で評価した。
結果を第９表に示す。耐汚れ性をブランケットの汚れの程度により１２段階評価した。数字が大きいほど耐汚れ性に優れることを示す。評価が７以上であれば、耐汚れ性に優れる平版印刷版として、実用的なレベルにある。
【０１７８】
（４）ベタ部の着肉性
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、ベタ部において画像の欠損、即ち、インキの着肉不良が発生した枚数により、ベタ部の着肉性を評価した。なお、印刷用紙としては、塗工再生紙（ＯＫコート、王子製紙社製）を用いた。
結果を第９表に示す。ベタ部のインキの着肉不良が発生した枚数により１２段階評価した。数字が大きいほどベタ部の着肉性に優れることを示す。評価が７以上であれば、耐汚れ性に優れる平版印刷版として、実用的なレベルにある。
【０１７９】
（５）ポツ状残膜の発生の有無
各版面エネルギー量で露光したサンプルの現像後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。ポツ状残膜が観察されないサンプルの版面エネルギー量の最小値により、ポツ状残膜を評価した。
結果を第９表に示す。版面エネルギー量の最小値が小さかったものから大きかったものまでを順に、◎、○、○△、×として表した。
【０１８０】
第８表および第９表から明らかなように、原子間力顕微鏡を用いて、表面の５０μｍ□を５１２×５１２点測定して得られる３次元データから求められる表面積比ΔＳ^５０および急峻度ａ４５^{５０（０．２−２）} がそれぞれ特定の条件を満たす本発明の平版印刷版用支持体（実施例１〜８）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および耐汚れ性に優れ、かつ、ベタ部の着肉不良が発生しにくい。
また、原子間力顕微鏡を用いて、表面の５μｍ□を５１２×５１２点測定して得られる３次元データから求められる表面積比ΔＳ^{５（０．０２−０．２）} および急峻度ａ４５^{５（０．０２−０．２）} それぞれ特定の条件を満たす本発明の平版印刷版用支持体（実施例１〜８）を用いた本発明の平版印刷版原版は、クリーナ耐刷性に優れる。
更に、表面に存在する深さ４μｍ以上の局所的深部の個数が、４００μｍ×４００μｍあたり６個以下である本発明の平版印刷版用支持体（実施例１〜８）を用いた本発明の平版印刷版原版は、ポツ状残膜が発生しにくい。
【０１８１】
【表８】

【０１８２】
【表９】

【０１８３】
【発明の効果】
以上に説明したように、表面形状に特徴を有する本発明の平版印刷版用支持体を用いれば、従来トレードオフの関係から脱しえなかった耐汚れ性と耐刷性のバランスを高い水準で維持することができ、かつ、塗工再生紙を用いた場合のベタ部におけるインキの着肉不良の発生を抑制することができる。
【図面の簡単な説明】
【図１】本発明の平版印刷版用支持体の作成における機械粗面化処理に用いられるブラシグレイニングの工程の概念を示す側面図である。
【図２】本発明の平版印刷版用支持体の作成における電気化学的粗面化処理に用いられる交番波形電流波形図の一例を示すグラフである。
【図３】本発明の平版印刷版用支持体の作成における交流を用いた電気化学的粗面化処理におけるラジアル型セルの一例を示す側面図である。
【図４】本発明の平版印刷版用支持体の作成における陽極酸化処理に用いられる陽極酸化処理装置の概略図である。
【符号の説明】
１ アルミニウム板
２、４ ローラ状ブラシ
３ 研磨スラリー液
５、６、７、８ 支持ローラ
１１ アルミニウム板
１２ ラジアルドラムローラ
１３ａ、１３ｂ 主極
１４ 電解処理液
１５ 電解液供給口
１６ スリット
１７ 電解液通路
１８ 補助陽極
１９ａ、１９ｂ サイリスタ
２０ 交流電源
４０ 主電解槽
５０ 補助陽極槽
４１０ 陽極酸化処理装置
４１２ 給電槽
４１４ 電解処理槽
４１６ アルミニウム板
４１８、４２６ 電解液
４２０ 給電電極
４２２、４２８ ローラ
４２４ ニップローラ
４３０ 電解電極
４３２ 槽壁
４３４ 直流電源[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lithographic printing plate support and a lithographic printing plate precursor.
Specifically, the present invention is excellent in stain resistance, and in particular, when the amount of dampening water is reduced, stains on the non-image area (background stain) are less likely to occur, and the image recording layer and the support in the image area The present invention relates to a support for a lithographic printing plate and a lithographic printing plate precursor that can be a lithographic printing plate that has strong adhesion, excellent printing durability, and is less liable to cause poor solid portion (solid image portion).
Further, the present invention provides a lithographic printing plate support capable of providing a lithographic printing plate having excellent properties (cleaner printing durability) in which printing durability does not deteriorate even when wiped with a cleaner, in addition to the properties described above, and Related to lithographic printing plate precursor.
Furthermore, in addition to the above-mentioned characteristics, the present invention is unlikely to generate a spot-like residual film (pot-like residual film), and particularly when a laser direct-drawing type image recording layer is provided, The present invention relates to a lithographic printing plate support and a lithographic printing plate precursor which can be used as a lithographic printing plate having an excellent effect of preventing the occurrence of residual film.
[0002]
[Prior art]
The lithographic printing method is a printing method that utilizes the fact that water and oil are not essentially mixed. The printing plate surface of the lithographic printing plate used for this is a region that accepts water and repels oil-based ink (hereinafter referred to as “removal”). This region is referred to as a “non-image portion”) and a region that repels water and receives oil-based ink (hereinafter, this region is referred to as “image portion”).
[0003]
An aluminum support for a lithographic printing plate used for a lithographic printing plate (hereinafter simply referred to as a “support for a lithographic printing plate”) is used so that its surface bears a non-image portion, and therefore has hydrophilicity and water retention. Are required to have various performances which are contradictory to each other, for example, excellent adhesion, and excellent adhesion to an image recording layer provided thereon.
If the hydrophilicity of the support is too low, ink will adhere to the non-image area during printing, and the blanket cylinder will be soiled, and so-called background soiling will occur. On the other hand, if the water holding capacity of the support is too low, the shadow portion is clogged unless dampening water is increased during printing. Therefore, the so-called water width is narrowed.
[0004]
On the other hand, in the non-image area, in order to maintain the resistance to dirt, it is preferable that the surface unevenness is gentle so that unnecessary ink does not adhere. However, if the surface unevenness is gentle, the image recording layer The adhesiveness between the substrate and the support is lowered, and the printing durability is lowered. That is, the stain resistance and the printing durability are in a trade-off relationship.
[0005]
In order to obtain a lithographic printing plate support having good performance, it is common to make the surface of an aluminum plate grained (roughening treatment) to give irregularities. Various shapes have been proposed for the unevenness as described below.
For example, a triple structure having a large wave, a medium wave and a small wave defining the opening diameters of the medium wave and the small wave (see Patent Document 1), and a structure defining the diameter of the small wave in a large and small double structure (Patent Documents 2 and 3). ), A technique for providing fine projections in addition to large and small double recesses (pits) (see Patent Document 4), a double structure that defines an opening diameter (see Patent Document 5), and surface Ratio of pit diameters superimposed in a double structure defining factor a30 indicating smoothness (see Patent Document 6) and a plurality of electrochemical roughening treatments (hereinafter also referred to as “electrolytic roughening treatment”) Has been proposed (see Patent Document 7).
[0006]
This graining includes mechanical graining methods such as ball graining, brush graining, wire graining, and blast graining, and an electrolytic grained surface for electrolytic etching of an aluminum plate in an electrolyte containing hydrochloric acid and / or nitric acid. And a composite roughening method (see Patent Document 8) in which a mechanical roughening method and an electrolytic roughening method are combined.
[0007]
[Patent Document 1]
JP-A-8-300844
[Patent Document 2]
JP 11-99758 A
[Patent Document 3]
Japanese Patent Laid-Open No. 11-208138
[Patent Document 4]
JP 11-167207 A
[Patent Document 5]
Japanese Patent No. 2023476
[Patent Document 6]
JP-A-8-300843
[Patent Document 7]
Japanese Patent Laid-Open No. 10-35133
[Patent Document 8]
US Pat. No. 4,476,006
[0008]
[Problems to be solved by the invention]
In addition, when using recycled paper (hereinafter referred to as “coated recycled paper”) whose surface is coated with a coating component in order to increase the whiteness as the printing material, ink imperfection occurs in the solid portion. Sometimes it is a problem.
However, it has excellent hydrophilicity and water retention, excellent stain resistance, excellent adhesion to the image recording layer, excellent printing durability, and solid printing when printed using coated recycled paper. A lithographic printing plate support that does not cause poor inking has not been realized.
Therefore, the present invention provides a lithographic printing plate that has excellent printing durability and stain resistance when used as a lithographic printing plate, and is less likely to cause poor solid walling when coated coated paper is used. It is an object of the present invention to provide a plate precursor and a lithographic printing plate support used therefor.
[0009]
[Means for Solving the Problems]
As a result of intensive studies on the surface shape of a lithographic printing plate support to solve the above problems, the present inventor has various factors representing the surface shape required using an atomic force microscope as a specific range. In addition, the inventors have found that the printing durability and stain resistance are excellent, and that the solid-walled defective in the solid portion hardly occurs when the coated recycled paper is used, and the present invention has been completed.
[0010]
That is, the present invention provides an actual area S obtained by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points on a surface of 50 μm □ using an atomic force microscope._x ⁵⁰And geometric measurement area S₀ ⁵⁰From the above, the surface area ratio ΔS determined by the following formula (1)⁵⁰Is steepness a45 which is an area ratio of a portion having a slope of 45 ° or more in data obtained by extracting components having a wavelength of 0.2 μm or more and 2 μm or less from the three-dimensional data.^{50 (0.2-2)}A lithographic printing plate support having a content of 5 to 40% is provided.
[0011]
ΔS⁵⁰= (S_x ⁵⁰-S₀ ⁵⁰) / S₀ ⁵⁰× 100 (%) (1)
[0012]
By the way, in the middle of printing, there is a case where the plate surface is cleaned using a chemical called a cleaner.This cleaner removes unnecessary ink adhering to the surface of the non-image area, and simultaneously with the image recording layer. It may permeate between the support and the adhesiveness of the support, thereby deteriorating the printing durability. Therefore, the property that the printing durability does not deteriorate even when wiped with a cleaner (cleaner printing durability) is an important characteristic for a lithographic printing plate.
[0013]
As a result of intensive studies on the surface shape of a lithographic printing plate support to solve the above problems, the present inventor has identified various factors representing the surface shape required using an atomic force microscope different from the above. It was found that when it was within the range, the cleaner printing durability was also excellent.
[0014]
That is, using an atomic force microscope, three approximate points are obtained from data obtained by extracting components having a wavelength of 0.02 μm to 0.2 μm from three-dimensional data obtained by measuring 512 × 512 points on the surface of 5 μm □. Real area S required by law_x ^{5 (0.02-0.2)}And geometric measurement area S₀ ⁵From the above, the surface area ratio ΔS determined by the following formula (2)^{5 (0.02-0.2)}Is a steepness a45 which is an area ratio of a portion having a slope of 45 ° or more in data obtained by extracting a component having a wavelength of 0.02 μm or more and 0.2 μm or less from the three-dimensional data.^{5 (0.02-0.2)}Is preferably 10 to 40%.
[0015]
ΔS^{5 (0.02-0.2)}= (S_x ^{5 (0.02-0.2)}-S₀ ⁵) / S₀ ⁵× 100 (%) (2)
[0016]
In general, it is effective to increase the surface roughness in order to improve water retention. However, if the surface roughness is increased, locally deep recesses are likely to be generated. A deep recess causes exposure failure and development failure, and a pot-like residual film is likely to occur. That is, improvement in water retention and improvement in pot-like residual film are contradictory.
[0017]
The present inventor has found that when the number of local deep portions having a specific depth or more existing on the surface is equal to or less than a specific numerical value, the generation of a pot-like residual film is extremely suppressed.
[0018]
That is, the number of local deep portions having a depth of 4 μm or more present on the surface is preferably 6 or less per 400 μm × 400 μm.
[0019]
The present invention also provides a lithographic printing plate precursor in which an image recording layer is provided on the lithographic printing plate support.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The lithographic printing plate support of the present invention has an actual area S determined by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points of 50 μm □ on the surface using an atomic force microscope._x ⁵⁰And geometric measurement area S₀ ⁵⁰From the above, the surface area ratio ΔS determined by the following formula (1)⁵⁰Is steepness a45 which is an area ratio of a portion having a slope of 45 ° or more in data obtained by extracting components having a wavelength of 0.2 μm or more and 2 μm or less from the three-dimensional data.^{50 (0.2-2)}Is 5 to 40%.
[0021]
ΔS⁵⁰= (S_x ⁵⁰-S₀ ⁵⁰) / S₀ ⁵⁰× 100 (%) (1)
[0022]
ΔS⁵⁰Is the geometric measurement area S₀ ⁵⁰Surface area S by roughening treatment_x ⁵⁰It is a factor that indicates the degree of increase in. ΔS⁵⁰When is increased, the contact area with the image recording layer is increased, and as a result, the printing durability can be improved. Here, the surface area ratio ΔS obtained without extracting the wavelength component from the three-dimensional data obtained by measuring 512 × 512 points on the surface of 50 μm □.⁵⁰That is, by increasing the surface area ratio including a component having a long wavelength, the contact area between the image recording layer and the support is increased, and the printing durability is improved. ΔS⁵⁰For example, the total amount of electricity involved in the anodic reaction in the electrolytic surface roughening treatment using an electrolytic solution mainly composed of hydrochloric acid is set to 300 C / dm.²A method of performing electrochemical surface roughening with the above-mentioned amount of electricity, a method of using three or more brush rolls in a mechanical surface roughening treatment using a brush roll and an abrasive, and the like can be used.
In the present invention, ΔS⁵⁰Is 30% or more, preferably 35% or more, and more preferably 40% or more. ΔS⁵⁰If it is too large, the resistance to contamination decreases, so it is preferably 60% or less.
[0023]
a45^{50 (0.2-2)}Is a factor representing the sharpness of the fine shape of the support surface. Specifically, the actual area S of the area having an inclination of 45 ° or more in the unevenness of the support surface._x ⁵⁰Represents the ratio to. As a result of various studies, the present inventor found that the steepness portion in the component having a wavelength of 0.2 μm or more and 2 μm or less tends to become a base point where ink is caught during printing in a non-image portion, and causes stains. . That is, for a component having a wavelength of 0.2 μm to 2 μm, a45^{50 (0.2-2)}It has been found that by reducing the size, the stain resistance can be improved.
[0024]
In addition, the present inventor has intensively studied the poor inking of the solid portion when the coated recycled paper is used, and as a result, the coating supplied from the paper to the steep portion of the support through the dampening water. It has been found that ink scum accumulates on the blanket, which tends to become a starting point for the components to be caught, and that the deposit becomes a physical obstacle especially in the vicinity of the solid portion, and the transfer of the ink from the blanket to the paper becomes insufficient. Furthermore, as a result of various studies, the present inventor has found that a45 is a component having a wavelength of 0.2 μm or more and 2 μm or less.^{50 (0.2-2)}It has been found that by reducing the thickness, it is possible to suppress the poor inking of the solid portion when the coated recycled paper is used.
[0025]
In the present invention, a45^{50 (0.2-2)}Is 40% or less, preferably 30% or less, and more preferably 20% or less. a45^{50 (0.2-2)}If it is too small, the printing durability may be lowered, so 5% or more is preferable.
[0026]
Further, in the present invention, an atomic force microscope is used to extract a component having a wavelength of 0.02 μm or more and 0.2 μm or less from three-dimensional data obtained by measuring 512 × 512 points of 5 μm □ on the surface. Real area S obtained from data by approximate three-point method_x ^{5 (0.02-0.2)}And geometric measurement area S₀ ⁵From the above, the surface area ratio ΔS determined by the following formula (2)^{5 (0.02-0.2)}Is a steepness a45 which is an area ratio of a portion having a slope of 45 ° or more in data obtained by extracting a component having a wavelength of 0.02 μm or more and 0.2 μm or less from the three-dimensional data.^{5 (0.02-0.2)}Is preferably 10 to 40%.
[0027]
ΔS^{5 (0.02-0.2)}= (S_x ^{5 (0.02-0.2)}-S₀ ⁵) / S₀ ⁵× 100 (%) (2)
[0028]
ΔS^{5 (0.02-0.2)}Is the geometric measurement area S₀ ⁵Surface area S by roughening treatment_x ^{5 (0.02-0.2)}It is a factor that indicates the degree of increase in. ΔS^{5 (0.02-0.2)}When is increased, the contact area with the image recording layer is increased, and as a result, the printing durability can be improved. Here, the surface area ratio ΔS in the data obtained by extracting components having a wavelength of 0.02 μm or more and 0.2 μm or less from three-dimensional data obtained by measuring 512 × 512 points on the surface of 5 μm □.^{5 (0.02-0.2)}That is, by increasing the surface area ratio contributed by the component having a short wavelength, the contact area between the image recording layer and the support is increased, the printing durability is improved, and the space between the image recording layer and the support is increased. It is possible to significantly suppress the penetration of the cleaner and improve the cleaner printing durability. ΔS^{5 (0.02-0.2)}For example, the total amount of electricity involved in the anodic reaction in a hydrochloric acid electrolyte is 10 to 100 C / dm.²A method of performing an AC electrolytic surface roughening treatment so as to become, after performing an AC electrolytic surface roughening treatment in a nitric acid electrolytic solution, a small amount of aluminum (for example, 0.1 to 0.3 g / m 2) with an alkaline solution²) A dissolving method can be used.
In the present invention, ΔS^{5 (0.02-0.2)}Is preferably 30% or more, more preferably 40% or more, and even more preferably 50% or more. ΔS^{5 (0.02-0.2)}If it is too large, it may cause development failure, so 60% or less is preferable.
[0029]
a45^{5 (0.02-0.2)}Is a factor representing the sharpness of the fine shape of the support surface. Specifically, the actual area S of the area having an inclination of 45 ° or more in the unevenness of the support surface._x ^{5 (0.02-0.2)}Represents the ratio to. As a result of various studies, the present inventor has found that if the steepness portion of the component having a wavelength of 0.02 μm or more and 2 μm or less is too large, the difficulty of entanglement of the ink decreases. That is, for a component having a wavelength of 0.02 μm or more and 0.2 μm or less, a45^{5 (0.02-0.2)}It was found that the difficulty of entanglement of the ink can be improved by reducing.
[0030]
In the present invention, a45^{5 (0.02-0.2)}Is preferably 40% or less, more preferably 30% or less, and even more preferably 20% or less. a45^{5 (0.02-0.2)}If it is too small, the printing durability may be lowered, so that it is preferably 10% or more.
[0031]
Furthermore, in the present invention, the number of local deep portions having a depth of 4 μm or more present on the surface is preferably 6 or less per 400 μm × 400 μm, and more preferably 4 or less. As a result, even if the conditions for exposure and development are strict, no pot-like residual film is generated.
[0032]
As a result of earnest research on the cause of the formation of a recess having a depth of 4 μm or more by the roughening treatment described later, the present inventor estimated the cause as follows.
First, when a roughening process including a mechanical roughening process is performed, the ridges of the abrasive particles used in the mechanical roughening process penetrate deeply into the surface of the aluminum plate to form a recess. To be done.
Secondly, when a roughening treatment including an electrolytic roughening treatment is performed, the current is concentrated at a specific location during the electrolytic roughening treatment.
[0033]
The present inventor has estimated the cause in this way, and as a result of earnest research, as a result of the following means, the number of recesses having a depth of 4 μm or more generated by the roughening treatment is 6 or less per 400 μm × 400 μm on the surface. Found that it can be.
That is, the following means (i) to (v) have been found for the piercing of abrasive particles used in the mechanical roughening treatment, which is the first cause.
(I) An abrasive having a small particle size is used.
For example, sedimentation separation is performed to remove large particles, and only small particles are used, or the particles of the abrasive are brought into contact with each other by re-grinding to reduce the particle size of the abrasive. can do.
(Ii) An abrasive with particles having few sharp edges is used.
Pumiston (hereinafter also referred to as “pumice”), which is usually used for mechanical surface roughening, is obtained by crushing volcanic ash, and its particles are shaped like a piece of glass like a broken glass with sharp edges. Yes. On the other hand, silica sand has a shape close to a dodecahedron or a 24-hedron, and has little sharpness.
[0034]
(Iii) The bristle used for the mechanical surface roughening treatment is softened.
For example, the brush hair can be softened by using a brush with a thin bristle diameter or using a soft brush.
(Iv) The rotational speed of the brush used for the mechanical surface roughening process is lowered.
By appropriately giving “escape” time to the abrasive particles contained in the slurry liquid, sticking is suppressed.
(V) Lowering the pressure (load) of the brush used for the mechanical surface roughening treatment.
[0035]
Further, the following means (vi) to (viii) have been found with respect to the fact that the current is concentrated at a specific location during the electrolytic surface-roughening treatment as the second cause.
(Vi) When an electrolytic solution mainly composed of nitric acid is used in the electrolytic surface-roughening treatment, the amount of Cu in the alloy component of the aluminum plate is lowered so that electrolysis is likely to occur uniformly.
In the electrolytic surface-roughening treatment, a smut in which the aluminum dissolution reaction (pitting reaction) and the components generated by the dissolution are reattached to the dissolution reaction part by passing an alternating current in an acidic electrolytic solution. Adhesion reactions occur alternately according to an alternating cycle. Here, in the case of using a nitric acid electrolytic solution, it is very easily affected by the kind and amount of alloy components contained in the aluminum plate, and in particular, the influence of Cu is large. This is presumably because the presence of Cu increases the surface resistance during the electrolytic surface roughening treatment. Therefore, by setting the amount of Cu in the alloy component to 0.002% by mass or less, the surface resistance during the electrolytic surface roughening treatment is reduced, so that current concentration is suppressed and uniform without forming coarse pits. Pits can be formed on the entire surface.
[0036]
(Vii) When an electrolytic solution mainly composed of nitric acid is used in the electrolytic surface roughening treatment, pre-electrolysis can be performed before the electrolytic surface roughening treatment.
In pre-electrolysis, the starting point of pit formation can be formed uniformly. Thereby, uniform pits can be formed on the entire surface without forming coarse pits in the subsequent electrolytic surface roughening treatment.
(Viii) When an electrolytic solution mainly composed of hydrochloric acid is used in the electrolytic surface roughening treatment, acetic acid or sulfuric acid is contained in the electrolytic solution.
Even in hydrochloric acid electrolysis, coarse pits may be formed due to current concentration, but when hydrochloric acid electrolyte containing acetic acid or sulfuric acid is used, uniform pits can be formed on the entire surface without forming coarse pits. Can do.
[0037]
In the lithographic printing plate support of the present invention, ΔS⁵⁰, A45^{50 (0.2-2)}, ΔS^{5 (0.02-0.2)}And a45^{5 (0.02-0.2)}The method of obtaining is as follows.
[0038]
(1) Surface shape measurement by atomic force microscope
In the present invention, ΔS⁵⁰, A45^{50 (0.2-2)}, ΔS^{5 (0.02-0.2)}And a45^{5 (0.02-0.2)}Is obtained by measuring the surface shape with an atomic force microscope (AFM) and obtaining three-dimensional data.
The measurement can be performed, for example, under the following conditions. That is, the lithographic printing plate support is cut to a size of 1 cm square, set on a horizontal sample stage on a piezo scanner, the cantilever is approached to the sample surface, and when the region where the atomic force works is reached, XY Scanning in the direction, the unevenness of the sample is captured by the displacement of the piezo in the Z direction. A piezo scanner that can scan 150 μm in the XY direction and 10 μm in the Z direction is used. The cantilever has a resonance frequency of 120 to 400 kHz and a spring constant of 12 to 90 N / m (for example, SI-DF20 and SI-DF40, both manufactured by Seiko Instruments; NCH, manufactured by NANOSENSORS; or AC-160TS, manufactured by Olympus) ) And measure in DFM mode (Dynamic Force Mode). Further, the reference plane is obtained by correcting the slight inclination of the sample by approximating the obtained three-dimensional data by least squares.
When measuring, ΔS⁵⁰And a45^{50 (0.2-2)}Measure the surface of 50 μm □ at 512 × 512 points. The resolution in the XY direction is 0.1 μm, the resolution in the Z direction is 0.15 nm, and the scan speed is 50 μm / sec.
ΔS^{5 (0.02-0.2)}And a45^{5 (0.02-0.2)}, Measure 512 × 512 points on the surface of 5 μm square. The resolution in the XY direction is 0.01 μm, the resolution in the Z direction is 0.15 nm, and the scan speed is 5 μm / sec.
[0039]
(2) Correction of 3D data
ΔS⁵⁰For the calculation, the three-dimensional data based on the measurement of 50 μm square of the surface obtained in the above (1) is used as it is.
a45^{50 (0.2-2)}Is calculated by extracting a component having a wavelength of 0.2 μm or more and 2 μm or less from three-dimensional data based on the measurement of 50 μm □ of the surface obtained in (1) above. Extraction of components having a wavelength of 0.2 μm or more and 2 μm or less is performed by performing a fast Fourier transform on the three-dimensional data obtained in (1) above to obtain a frequency distribution, and then a component having a wavelength less than 0.2 μm and a wavelength exceeding 2 μm After removing the components, the inverse Fourier transform is performed.
ΔS^{5 (0.02-0.2)}And a45^{5 (0.02-0.2)}Is calculated by extracting a component having a wavelength of 0.02 μm or more and 0.2 μm or less from three-dimensional data based on the measurement of 5 μm □ of the surface obtained in (1) above. Extraction of components having a wavelength of 0.02 μm or more and 0.2 μm or less is performed by performing a fast Fourier transform on the three-dimensional data obtained in (1) above to obtain a frequency distribution, and then a component having a wavelength less than 0.02 μm and a wavelength of 0 After removing components exceeding 2 μm, inverse Fourier transform is performed.
[0040]
(3) Calculation of each factor
▲ 1 ▼ ΔS⁵⁰
Using the three-dimensional data (f (x, y)) obtained in (1) above, three adjacent points are extracted, the sum of the areas of the minute triangles formed by the three points is obtained, and the actual area S_x ⁵⁰And Surface area ratio ΔS⁵⁰Is the actual area S obtained_x ⁵⁰And geometric measurement area S₀ ⁵⁰From the above, it is obtained by the above formula (1).
[0041]
▲ 2 ▼ a45^{50 (0.2-2)}
Using three-dimensional data (f (x, y)) obtained by correcting in (2) above, each reference point is formed by three points in the predetermined direction (for example, right and bottom). The angle formed by the small triangle to be formed and the reference plane is calculated for each reference point. The number of reference points where the inclination of the micro triangle is 45 degrees or more is obtained by subtracting the number of all reference points (the number of all data 512 × 512 points from the number of points that do not have two adjacent points in a predetermined direction). I.e., 511 × 511 points), and the area ratio a45 of the portion having the inclination of 45 degrees or more.^{50 (0.2-2)}Is calculated.
[0042]
(3) ΔS^{5 (0.02-0.2)}
Using the three-dimensional data (f (x, y)) obtained by correcting in (2) above, three adjacent points are extracted, and the total area of the micro triangles formed by the three points is obtained. Area S_x ^{5 (0.02-0.2)}And Surface area ratio ΔS^{5 (0.02-0.2)}Is the actual area S obtained_x ^{5 (0.02-0.2)}And geometric measurement area S₀ ⁵From the above, it is obtained by the above formula (2).
[0043]
▲ 4 ▼ a45^{5 (0.02-0.2)}
Using three-dimensional data (f (x, y)) obtained by correcting in (2) above, each reference point is formed by three points in the predetermined direction (for example, right and bottom). The angle formed by the small triangle to be formed and the reference plane is calculated for each reference point. The number of reference points where the inclination of the micro triangle is 45 degrees or more is obtained by subtracting the number of all reference points (the number of all data 512 × 512 points from the number of points that do not have two adjacent points in a predetermined direction). I.e., 511 × 511 points), and the area ratio a45 of the portion having the inclination of 45 degrees or more.^{5 (0.02-0.2)}Is calculated.
[0044]
In the lithographic printing plate support of the present invention, the method for measuring the number of local deep portions having a depth of 4 μm or more present on the surface is as follows.
Using a laser microscope, 400 μm □ of the surface is scanned in a non-contact manner with a resolution of 0.01 μm to obtain three-dimensional data, and the number of recesses having a depth of 4 μm or more is counted in this three-dimensional data.
[0045]
<Surface treatment>
The lithographic printing plate support of the present invention is one in which the above-mentioned surface grain shape is formed on the surface of the aluminum plate by subjecting the aluminum plate to be described later to surface treatment. The lithographic printing plate support of the present invention is obtained by subjecting an aluminum plate to a surface roughening treatment, but the production process of this support is not particularly limited, and includes various steps other than the surface roughening treatment. May be.
In the following, as a representative method for forming the above-described surface grain shape,
A method of sequentially performing mechanical surface roughening treatment, alkali etching treatment, desmutting treatment with an acid and electrochemical surface roughening treatment using an electrolytic solution on an aluminum plate,
A method of performing mechanical surface roughening treatment, alkali etching treatment, desmutting treatment with acid and electrochemical surface roughening treatment using different electrolytes a plurality of times on an aluminum plate,
A method of sequentially performing an alkali etching treatment, an acid desmutting treatment on an aluminum plate, and an electrochemical surface roughening treatment using an electrolytic solution,
A method of subjecting an aluminum plate to alkaline etching treatment, desmutting treatment with acid, and electrochemical surface roughening treatment using different electrolytes multiple times.
However, the present invention is not limited to these. In these methods, after the electrochemical roughening treatment, an alkali etching treatment and an acid desmutting treatment may be further performed.
[0046]
ΔS, a factor representing the surface shape⁵⁰, A45^{50 (0.2-2)}, ΔS^{5 (0.02-0.2)}, A45^{5 (0.02-0.2)}As a roughening treatment suitably used for the number of local deep portions having a depth of 4 μm or more existing on the surface to satisfy specific conditions, other treatments (alkali etching treatment, etc.) Depending on the conditions, mechanical surface roughening, hydrochloric acid electrolysis (electrochemical surface roughening mainly composed of hydrochloric acid), nitric acid electrolysis (electrochemical surface roughening mainly composed of nitric acid), and combinations of these For example, a method of sequentially performing the processes described above. Another example is a method in which only an electrochemical surface roughening treatment in which the total amount of electricity involved in the anodic reaction is increased is performed using an electrochemical surface roughening treatment mainly composed of hydrochloric acid.
[0047]
The lithographic printing plate support of the present invention obtained by these methods and having the above-mentioned factors representing the surface shape satisfy specific conditions, respectively, is excellent in printing durability and stain resistance when used as a lithographic printing plate. In addition, in the case of using coated recycled paper, it is difficult for the solid portion to have poor walling. Further, the lithographic printing plate support of the present invention is preferably excellent in cleaner printing durability and is less likely to generate a pot-like residual film.
Hereinafter, each step of the surface treatment will be described in detail.
[0048]
<Mechanical roughening>
The mechanical roughening treatment is effective as a roughening treatment means because it can form an uneven surface with an average wavelength of 5 to 100 μm at a lower cost than the electrochemical roughening treatment. is there.
Examples of the mechanical surface roughening treatment include, for example, a wire brush grain method in which the aluminum surface is scratched with a metal wire, a ball grain method in which the aluminum surface is grained with a polishing ball and an abrasive, JP-A-6-135175, and Japanese Patent Publication A brush grain method in which the surface is grained with a nylon brush and an abrasive described in Japanese Patent No. 50-40047 can be used.
A transfer method in which the uneven surface is pressed against the aluminum plate can also be used. That is, JP-A 55-74898, JP-A 60-36195, JP-A 60-36196, JP-A 60-20396, JP-A 61-162351, JP-B-4-30358. In addition to the method described in the publication, JP-A-6-55871 characterized in that the transfer is carried out several times, and Japanese Patent Application No. 4-204235 characterized in that the surface is elastic (Japanese Unexamined Patent Publication No. 4-204235). 6-024168) is also applicable.
As will be described later, in the brush grain method, it is particularly preferable to use a plurality of nylon brushes, and various abrasive materials described later can be used as the abrasive, but it is preferable to use pumiston, silica sand, aluminum hydroxide or the like. preferable. In the transfer method, it is preferable to appropriately adjust the rotational speed, load, and the like of the drive motor that rotates the brush.
[0049]
In addition, by using electric discharge machining, shot blasting, laser, plasma etching, etc., a method of performing repetitive transfer using a transfer roll etched with fine irregularities, or an uneven surface coated with fine particles on an aluminum plate It is also possible to use a method in which the surface is brought into contact and a pressure is repeatedly applied several times from above to repeatedly transfer an uneven pattern corresponding to the average diameter of the fine particles to the aluminum plate a plurality of times. As a method for imparting fine irregularities to the transfer roll, known methods described in JP-A-3-8635, JP-A-3-66404, JP-A-63-65017, etc. may be used. it can. Further, a fine groove may be cut from two directions using a die, a cutting tool, a laser or the like on the roll surface, and the surface may be provided with square irregularities. The roll surface may be subjected to a known etching process or the like so that the formed square irregularities are rounded.
Further, in order to increase the surface hardness, quenching, hard chrome plating, or the like may be performed.
In addition, as the mechanical surface roughening treatment, methods described in JP-A Nos. 61-162351 and 63-104889 can be used.
In the present invention, the above-described methods can be used in combination in consideration of productivity and the like. These mechanical surface roughening treatments are preferably performed before the electrochemical surface roughening treatment.
[0050]
Hereinafter, the brush grain method used suitably as a mechanical roughening process is demonstrated.
The brush grain method generally uses a roller-shaped brush in which a large number of brush hairs such as synthetic resin hair made of synthetic resin such as nylon (trade name), propylene, and vinyl chloride resin are implanted on the surface of a cylindrical body. This is performed by rubbing one or both of the surfaces of the aluminum plate while spraying a slurry liquid containing an abrasive on a rotating roller brush. Instead of the roller brush and the slurry liquid, a polishing roller which is a roller having a polishing layer on the surface can be used.
When using a roller brush, the flexural modulus is preferably 10,000 to 40,000 kg / cm.², More preferably 15,000-35,000 kg / cm²In addition, brush hair having a bristle waist strength of preferably 500 g or less, more preferably 400 g or less is used. The diameter of the brush bristles is generally 0.2 to 0.9 mm. The length of the brush bristles can be appropriately determined according to the outer diameter of the roller brush and the diameter of the body, but is generally 10 to 100 mm.
In the present invention, it is preferable to use a plurality of nylon brushes, specifically, 3 or more are more preferable, and 4 or more are particularly preferable. By adjusting the number of brushes, the wavelength component of the recess formed on the aluminum plate surface can be adjusted.
The load of the drive motor that rotates the brush is preferably 1 kW plus or more, more preferably 2 kW plus or more, and particularly preferably 8 kW plus or more with respect to the load before the brush roller is pressed against the aluminum plate. By adjusting the load, the depth of the recess formed on the surface of the aluminum plate can be adjusted. The number of rotations of the brush is preferably 100 or more, and particularly preferably 200 or more.
[0051]
A well-known thing can be used for an abrasive | polishing agent. For example, abrasives such as pumicestone, silica sand, aluminum hydroxide, alumina powder, silicon carbide, silicon nitride, volcanic ash, carborundum, and gold sand; a mixture thereof can be used. Of these, pumiston and silica sand are preferable. In particular, silica sand is preferable in terms of excellent roughening efficiency because it is harder and less likely to break than Pamiston. In addition, aluminum hydroxide is suitable when an excessive load is applied and the particles are damaged, so that it is not desired to generate deep recesses locally.
The average particle diameter of the abrasive is preferably 3 to 50 μm, and more preferably 6 to 45 μm in terms of excellent surface roughening efficiency and a narrow graining pitch. By adjusting the average particle size of the abrasive, the depth of the recesses formed on the aluminum plate surface can be adjusted.
For example, the abrasive is suspended in water and used as a slurry. In addition to the abrasive, the slurry liquid may contain a thickener, a dispersant (for example, a surfactant), a preservative, and the like. The specific gravity of the slurry liquid is preferably 0.5-2.
As an apparatus suitable for the mechanical surface roughening treatment, for example, an apparatus described in Japanese Patent Publication No. 50-40047 can be given.
[0052]
Hereinafter, an example of a transfer method used as the mechanical roughening process will be described.
In general, the transfer method transfers the unevenness of the rolling roll through an aluminum plate to a rolling roll (transfer roll) embossed by shot blasting, engraving, laser processing or pattern etching, or polished on paper or plastic sheet. This is a method in which a material, glass beads, or the like applied is superimposed on an aluminum plate, rolled and transferred to roughen the aluminum plate.
In addition to the above-described method, the following method can be used for the transfer method.
Method for avoiding problems of transfer roller life and aluminum sheet stretching by setting the reduction rate of the transfer roller low (Japanese Patent Laid-Open No. 7-205565); Transfer is repeated a plurality of times, preferably four or more times This method eliminates the need for sticking to the processing accuracy such as the cylindricity of the transfer roll, reduces the elongation of the aluminum plate, and provides a sufficiently uniform rough surface as an aluminum support for a printing plate (JP-A-6-55871). ); Random arrangement and uniform distribution by pressing the aluminum plate 1-6 times on a chemically roughened metal surface that is harder than lithographic printing plate aluminum. Can be made at a low cost (Japanese Patent Laid-Open No. 6-171258); a large number of non-directional press recesses are formed on the surface of the aluminum plate. A photoresist or plastic resin coated and dried on a metal surface is exposed and irradiated with infrared light, a laser, or the like to form a resist pattern; Thereafter, chemical etching or the like is performed to produce and transfer a rough surface on the metal surface, thereby transferring a sufficiently uniform unevenness (JP-A-6-171262) or the like.
[0053]
In the transfer method, the size of the projections (surface roughness of the transfer roll) provided on the transfer roll and the like, and the size of the recesses formed on the aluminum plate transferred by the transfer roll (surface of the aluminum plate by the transfer method) (Roughness) is almost the same.
Therefore, in order to form the desired surface roughness on the aluminum plate, a transfer roll having a surface roughness substantially the same as the surface roughness may be used.
The transfer roller is configured by providing fine convex portions on the surface of a roller metal core made of, for example, SUS304, SUS316, SCM steel, SUJ steel, SS41, or the like by thermal spraying, laser, machining, or the like.
In the thermal spraying method, ceramic particles having a particle size of about 10 to 60 μm and ceramic sintered bodies are coated on the roller surface to a thickness of about 0.1 to 0.6 mm by plasma spraying, thermal spraying with a DJ gun, or thermal spraying with a wire. It is obtained by polishing the surface. As the kind of ceramics, oxide ceramics mainly composed of chromium oxide and nitride ceramics mainly composed of silicon nitride are preferable from the viewpoint of strength. Moreover, since the roller surface formed by thermal spraying is rough, it is polished.
On the other hand, the method of forming the convex portion by laser uses the fact that the laser irradiated portion of the roller surface melts and rises, and the laser forms the vertical groove and the horizontal groove on the roller surface in a lattice shape at right angles or at an angle. By doing so, it is possible to form independent protrusions cut out by both grooves. The laser used is CO₂A laser, a YAG laser, an excimer laser, etc. can be mentioned. Moreover, the groove width formed differs depending on the type of laser. Therefore, it is necessary to select the type of laser according to the desired size of the convex portion, and it is necessary to use a laser having a short wavelength such as an excimer laser in order to obtain a transfer roller having a finer uneven shape. Moreover, it is finished with a diamond grindstone, a ceramic grindstone, or a polishing paper containing these.
[0054]
Similarly, by using a die or a cutting tool on the roller surface, fine grooves can be cut in a lattice shape from two directions to give square irregularities.
The aluminum plate or aluminum alloy plate is inserted between the transfer roller and a mirror-finished metal roller (backup roll), and is composed of a convex portion of the transfer roller under a linear pressure reduction of about 3 to 30 kg / mm. The uneven pattern is transferred. Details are described in JP-A-7-205565.
The conditions for the composition surface treatment in the transfer method can be appropriately adjusted according to the desired surface roughness.
[0055]
<Electrochemical roughening treatment>
In the electrochemical surface roughening treatment, an electrolytic solution used for the electrochemical surface roughening treatment using a normal alternating current can be used. Among them, the use of an electrolytic solution mainly composed of hydrochloric acid or nitric acid is preferable so that each of the above factors representing the surface shape satisfies a specific condition.
As the electrolytic surface roughening treatment in the present invention, it is preferable to perform the first and second electrolytic treatments with an alternating waveform current in an acidic solution before and after the cathodic electrolytic treatment. By cathodic electrolysis, hydrogen gas is generated on the surface of the aluminum plate and smut is generated to make the surface state uniform, and it is possible to obtain a uniform electrolytic surface during the subsequent electrolysis with an alternating waveform current. .
This electrolytic surface roughening treatment can be performed according to, for example, an electrochemical grain method (electrolytic grain method) described in Japanese Patent Publication No. 48-28123 and British Patent No. 896,563. This electrolytic grain method uses a sinusoidal alternating current, but it may be performed using a special waveform as described in JP-A-52-58602. Further, the waveform described in JP-A-3-79799 can also be used. JP-A-55-158298, JP-A-56-28898, JP-A-52-58602, JP-A-52-152302, JP-A-54-85802, JP-A-60-190392, JP-A-58-120531, JP-A-63-176187, JP-A-1-5889, JP-A-1-280590, JP-A-1-118489, JP-A-1-148592, and JP-A-1-17896. JP-A-1-188315, JP-A-1-1549797, JP-A-2-235794, JP-A-3-260100, JP-A-3-253600, JP-A-4-72079, JP-A-4-72098, The methods described in JP-A-3-267400 and JP-A-1-141094 can also be applied. In addition to the above, it is also possible to perform electrolysis using an alternating current having a special frequency that has been proposed as a method of manufacturing an electrolytic capacitor. For example, it is described in US Pat. Nos. 4,276,129 and 4,676,879.
[0056]
Various electrolyzers and power sources have been proposed. U.S. Pat. No. 4,023,637, JP-A-56-123400, JP-A-57-59770, JP-A-53-12738, JP-A-53. -32821, JP-A 53-32822, JP-A 53-32823, JP-A 55-122896, JP-A 55-13284, JP-A 62-127500, JP-A-1-52100 JP-A-1-52098, JP-A-60-67700, JP-A-1-230800, JP-A-3-257199 and the like can be used. Also, JP-A-52-58602, JP-A-52-152302, JP-A-53-12738, JP-A-53-12739, JP-A-53-32821, JP-A-53-32822, JP 53-32833, JP 53-32824, JP 53-32825, JP 54-85802, JP 55-122896, JP 55-13284, JP 48-28123, JP-B-51-7081, JP-A-52-133638, JP-A-52-133840, JP-A-52-133844, JP-A-52-133845, JP-A-53-149135 And those described in JP-A No. 54-146234 and the like can also be used.
[0057]
As an acidic solution which is an electrolytic solution, in addition to nitric acid and hydrochloric acid, U.S. Pat. Nos. 4,671,859, 4,661,219, 4,618,405, 4,600, 482, 4,566,960, 4,566,958, 4,566,959, 4,416,972, 4,374,710, The electrolyte solution described in each specification of 4,336,113 and 4,184,932 can also be used.
[0058]
The concentration of the acidic solution is preferably 0.5 to 2.5% by mass, but it is particularly preferably 0.7 to 2.0% by mass in consideration of use in the smut removal treatment. Moreover, it is preferable that liquid temperature is 20-80 degreeC, and it is more preferable that it is 30-60 degreeC.
[0059]
An aqueous solution mainly composed of hydrochloric acid or nitric acid is an aqueous solution of hydrochloric acid or nitric acid having a concentration of 1 to 100 g / L, such as nitric acid compounds having nitrate ions such as aluminum nitrate, sodium nitrate, ammonium nitrate, aluminum chloride, sodium chloride, ammonium chloride, At least one of the hydrochloric acid compounds having hydrochloric acid ions can be used by adding in a range from 1 g / L to saturation. Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, a silica, may melt | dissolve in the aqueous solution which has hydrochloric acid or nitric acid as a main component. Preferably, a solution obtained by adding aluminum chloride, aluminum nitrate or the like to an aqueous solution of hydrochloric acid or nitric acid having a concentration of 0.5 to 2% by mass so that aluminum ions are 3 to 50 g / L is preferably used.
[0060]
Further, by adding and using a compound capable of forming a complex with Cu, uniform graining is possible even for an aluminum plate containing a large amount of Cu. Examples of the compound capable of forming a complex with Cu include ammonia; hydrogen atom of ammonia such as methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, cyclohexylamine, triethanolamine, triisopropanolamine, EDTA (ethylenediaminetetraacetic acid). And amines obtained by substituting with a hydrocarbon group (aliphatic, aromatic, etc.); metal carbonates such as sodium carbonate, potassium carbonate, potassium hydrogen carbonate and the like. In addition, ammonium salts such as ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium phosphate, and ammonium carbonate are also included.
The temperature is preferably 10-60 ° C, more preferably 20-50 ° C.
[0061]
The AC power supply wave used for the electrochemical surface roughening treatment is not particularly limited, and a sine wave, a rectangular wave, a trapezoidal wave, a triangular wave or the like is used, but a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal wave is particularly preferable. A trapezoidal wave means what was shown in FIG. In this trapezoidal wave, the time (TP) until the current reaches a peak from zero is preferably 0.3 to 3 msec. If it is less than 0.3 msec, processing irregularities such as chatter marks that occur perpendicular to the traveling direction of the aluminum plate tend to occur. When TP exceeds 3 msec, especially when a nitric acid electrolyte is used, it is easily affected by trace components in the electrolyte typified by ammonium ions and the like that spontaneously increase by electrolytic treatment, and uniform graining is performed. It becomes hard to be broken. As a result, the stain resistance tends to decrease when a lithographic printing plate is obtained.
[0062]
A trapezoidal wave alternating current duty ratio of 1: 2 to 2: 1 can be used. However, as described in Japanese Patent Laid-Open No. 5-195300, in an indirect power feeding method in which no conductor roll is used for aluminum. A duty ratio of 1: 1 is preferable. A trapezoidal AC frequency of 0.1 to 120 Hz can be used, but 50 to 70 Hz is preferable in terms of equipment. When the frequency is lower than 50 Hz, the carbon electrode of the main electrode is easily dissolved, and when the frequency is higher than 70 Hz, it is easily affected by an inductance component on the power supply circuit, and the power supply cost is increased.
[0063]
One or more AC power supplies can be connected to the electrolytic cell. As shown in FIG. 3, the current ratio between the AC anode and cathode applied to the aluminum plate facing the main electrode is controlled to achieve uniform graining and to dissolve the carbon of the main electrode. In addition, it is preferable to install an auxiliary anode and divert part of the alternating current. In FIG. 3, 11 is an aluminum plate, 12 is a radial drum roller, 13a and 13b are main poles, 14 is an electrolytic treatment liquid, 15 is an electrolytic solution supply port, and 16 is a slit. , 17 is an electrolyte passage, 18 is an auxiliary anode, 19a and 19b are thyristors, 20 is an AC power source, 40 is a main electrolytic cell, and 50 is an auxiliary anode cell. An anodic reaction that acts on the aluminum plate facing the main electrode by diverting a part of the current value as a direct current to an auxiliary anode provided in a tank separate from the two main electrodes via a rectifier or switching element It is possible to control the ratio between the current value for the current and the current value for the cathode reaction. On the aluminum plate facing the main electrode, the ratio of the amount of electricity involved in the anodic reaction and the cathodic reaction (the amount of electricity at the time of cathode / the amount of electricity at the time of anode) is preferably 0.3 to 0.95.
[0064]
As the electrolytic cell, electrolytic cells used for known surface treatments such as a vertical type, a flat type, and a radial type can be used, but a radial type electrolytic cell as described in JP-A-5-195300 is particularly preferable. . The electrolytic solution passing through the electrolytic cell may be parallel to the traveling direction of the aluminum web or may be a counter.
[0065]
(Nitric acid electrolysis)
Pits having an average opening diameter of 0.5 to 5 μm can be formed by electrochemical surface roughening using an electrolytic solution mainly composed of nitric acid. However, when the amount of electricity is relatively large, the electrolytic reaction is concentrated, and honeycomb pits exceeding 5 μm are also generated.
In order to obtain such a grain, the total amount of electricity involved in the anode reaction of the aluminum plate at the time when the electrolytic reaction is completed is 1 to 1000 C / dm.²Is preferably 50 to 300 C / dm.²It is more preferable that The current density at this time is 20 to 100 A / dm.²Is preferred.
[0066]
(Hydrochloric acid electrolysis)
Since hydrochloric acid has a strong aluminum dissolving power, it is possible to form fine irregularities on the surface with only slight electrolysis. These fine irregularities have an average opening diameter of 0.01 to 0.2 μm and are uniformly generated on the entire surface of the aluminum plate. In order to obtain such a grain, the total amount of electricity involved in the anode reaction of the aluminum plate at the time when the electrolytic reaction is completed is 1 to 100 C / dm.²It is preferable that it is 20-70 C / dm.²It is more preferable that This maximum current density is 10-50 A / dm²Is preferred.
[0067]
In such an electrochemical surface roughening treatment with an electrolyte mainly composed of hydrochloric acid, the total amount of electricity involved in the anode reaction is 400 to 2000 C / dm.²It is possible to simultaneously form a large crater-like undulation by increasing the crater shape, but in this case, an average opening diameter of 0.01 to 0.4 μm is superimposed on the crater-like undulation having an average opening diameter of 10 to 30 μm. Fine irregularities are generated on the entire surface.
[0068]
The aluminum plate is preferably subjected to cathodic electrolysis treatment during the first and second electrolytic surface-roughening treatments performed in the electrolytic solution such as nitric acid and hydrochloric acid. By this cathodic electrolysis treatment, smut is generated on the surface of the aluminum plate, and hydrogen gas is generated to enable more uniform electrolytic surface roughening treatment. The cathodic electrolysis is preferably performed in an acidic solution with a cathode electric quantity of 3 to 80 C / dm.², More preferably 5-30 C / dm²Done in Cathode electricity is 3 C / dm²If it is less than 80, the smut adhesion amount may be insufficient, and 80 C / dm.²If it exceeds 1, the amount of smut adhesion may become excessive, which is not preferable. Further, the electrolytic solution may be the same as or different from the solution used in the first and second electrolytic surface roughening processes.
[0069]
<Alkaline etching treatment>
The alkali etching treatment is a treatment for dissolving the surface layer by bringing the aluminum plate into contact with an alkali solution.
[0070]
Alkaline etching performed before the electrolytic surface roughening treatment removes rolling oil, dirt, natural oxide film, etc. on the surface of the aluminum plate (rolled aluminum) if mechanical surface roughening treatment is not performed. If the surface of the unevenness generated by the mechanical surface roughening treatment is dissolved, the surface with sharp undulations is smoothed. It is done for the purpose of changing.
[0071]
When the mechanical surface roughening treatment is not performed before the alkali etching treatment, the etching amount is 0.1 to 10 g / m.²1 to 5 g / m is preferable.²It is more preferable that Etching amount is 0.1g / m²If it is less than that, rolling oil, dirt, natural oxide film, etc. on the surface may remain, so that uniform pits cannot be generated in the subsequent electrolytic surface roughening treatment, and unevenness may occur. On the other hand, the etching amount is 1 to 10 g / m.²If it is, removal of rolling oil, dirt, natural oxide film, etc. on the surface is sufficiently performed. An etching amount exceeding the above range is economically disadvantageous.
[0072]
When mechanical roughening treatment is performed before the alkali etching treatment, the etching amount is 3 to 20 g / m.²Is preferably 5 to 15 g / m.²It is more preferable that Etching amount is 3g / m²If it is less than 1, the unevenness formed by mechanical surface roughening or the like may not be smoothed, and uniform pit formation may not be possible in the subsequent electrolytic treatment. In addition, the stain may deteriorate during printing. On the other hand, the etching amount is 20 g / m.²Exceeding may cause the concavo-convex structure to disappear.
[0073]
The alkali etching treatment performed immediately after the electrolytic surface roughening treatment is performed for the purpose of dissolving the smut generated in the acidic electrolytic solution and dissolving the edge portion of the pit formed by the electrolytic surface roughening treatment. .
Since the pits formed by the electrolytic surface roughening treatment are different depending on the type of the electrolytic solution, the optimum etching amount is also different, but the etching amount of the alkali etching treatment performed after the electrolytic surface roughening treatment is 0.1 to 5 g / m.²Is preferred. When a nitric acid electrolyte is used, the etching amount needs to be set larger than when a hydrochloric acid electrolyte is used.
When the electrolytic surface roughening treatment is performed a plurality of times, an alkali etching treatment can be performed as necessary after each treatment.
[0074]
Examples of the alkali used in the alkaline solution include caustic alkali and alkali metal salts. Specifically, examples of caustic alkali include caustic soda and caustic potash. Examples of the alkali metal salt include alkali metal silicates such as sodium silicate, sodium silicate, potassium metasilicate, and potassium silicate; alkali metal carbonates such as sodium carbonate and potassium carbonate; sodium aluminate and alumina. Alkali metal aluminates such as potassium acid; alkali metal aldones such as sodium gluconate and potassium gluconate; dibasic sodium phosphate, dibasic potassium phosphate, primary sodium phosphate, primary potassium phosphate, etc. An alkali metal hydrogen phosphate is mentioned. Among these, a caustic alkali solution and a solution containing both a caustic alkali and an alkali metal aluminate are preferable from the viewpoint of high etching rate and low cost. In particular, an aqueous solution of caustic soda is preferable.
[0075]
Although the density | concentration of an alkaline solution can be determined according to the etching amount, it is preferable that it is 1-50 mass%, and it is more preferable that it is 10-35 mass%. When aluminum ions are dissolved in the alkaline solution, the concentration of aluminum ions is preferably 0.01 to 10% by mass, and more preferably 3 to 8% by mass. The temperature of the alkaline solution is preferably 20 to 90 ° C. The treatment time is preferably 1 to 120 seconds.
[0076]
Examples of the method of bringing the aluminum plate into contact with the alkaline solution include, for example, a method in which the aluminum plate is passed through a tank containing the alkaline solution, a method in which the aluminum plate is immersed in a tank containing the alkaline solution, The method of spraying on the surface of a board is mentioned.
[0077]
<Desmut treatment>
After the electrolytic surface roughening treatment or the alkali etching treatment, pickling (desmut treatment) is performed to remove dirt (smut) remaining on the surface. Examples of the acid used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and borohydrofluoric acid.
The desmutting treatment is performed, for example, by bringing the aluminum plate into contact with an acidic solution having a concentration of 0.5 to 30% by mass (containing 0.01 to 5% by mass of aluminum ions) such as hydrochloric acid, nitric acid, and sulfuric acid. . Examples of the method of bringing the aluminum plate into contact with the acidic solution include, for example, a method of passing the aluminum plate through a bath containing the acidic solution, a method of immersing the aluminum plate in a bath containing the acidic solution, and an acidic solution containing aluminum. The method of spraying on the surface of a board is mentioned.
In the desmutting treatment, the acidic solution is mainly composed of an aqueous solution mainly composed of nitric acid or an aqueous solution mainly composed of hydrochloric acid discharged in the above-described electrolytic surface-roughening treatment, or sulfuric acid discharged in an anodic oxidation process described later. It is possible to use a waste solution of an aqueous solution.
It is preferable that the liquid temperature of a desmut process is 25-90 degreeC. Moreover, it is preferable that processing time is 1-180 second. Aluminum and aluminum alloy components may be dissolved in the acidic solution used for the desmut treatment.
[0078]
<Anodizing treatment>
The aluminum plate treated as described above is preferably further subjected to an anodizing treatment. The anodizing treatment can be performed by a method conventionally used in this field. In this case, for example, in a solution having a sulfuric acid concentration of 50 to 300 g / L and an aluminum concentration of 5% by mass or less, an anodized film can be formed by energizing an aluminum plate as an anode. As a solution used for the anodizing treatment, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, amidosulfonic acid and the like can be used alone or in combination of two or more.
[0079]
Under the present circumstances, the component normally contained at least in an aluminum plate, an electrode, tap water, groundwater, etc. may be contained in electrolyte solution. Furthermore, the 2nd, 3rd component may be added. Examples of the second and third components herein include metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; Cations such as ammonium ion; anions such as nitrate ion, carbonate ion, chloride ion, phosphate ion, fluoride ion, sulfite ion, titanate ion, silicate ion, borate ion, etc., 0 to 10000 ppm It may be contained at a concentration of about.
[0080]
The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be determined unconditionally. In general, however, the electrolyte concentration is 1 to 80% by mass, the solution temperature is 5 to 70 ° C., and the current density is 0.5. ~ 60A / dm²It is appropriate that the voltage is 1 to 100 V and the electrolysis time is 15 seconds to 50 minutes.
[0081]
Further, JP-A-54-81133, JP-A-57-47894, JP-A-57-51289, JP-A-57-51290, JP-A-57-54300, JP-A-57-136596, JP-A-58-107498, JP-A-60-200366, JP-A-62-136696, JP-A-63-176494, JP-A-4-17697, JP-A-4-280997, JP-A-6-280997 The methods described in JP-A-207299, JP-A-5-24377, JP-A-5-32083, JP-A-5-125597, JP-A-5-195291 and the like can also be used.
[0082]
Of these, as described in JP-A-54-12853 and JP-A-48-45303, it is preferable to use a sulfuric acid solution as the electrolytic solution. The sulfuric acid concentration in the electrolytic solution is preferably 10 to 300 g / L (1 to 30% by mass), and the aluminum ion concentration is 1 to 25 g / L (0.1 to 2.5% by mass). It is preferable that it is 2 to 10 g / L (0.2 to 1% by mass). Such an electrolytic solution can be prepared, for example, by adding aluminum sulfate or the like to dilute sulfuric acid having a sulfuric acid concentration of 50 to 200 g / L.
[0083]
When anodizing is performed in an electrolytic solution containing sulfuric acid, direct current may be applied between the aluminum plate and the counter electrode, or alternating current may be applied.
When direct current is applied to the aluminum plate, the current density is 1 to 60 A / dm.²Is preferably 5 to 40 A / dm.²It is more preferable that
In the case of continuously performing anodizing treatment, 5-10 A / m at the beginning of the anodizing treatment so that current is concentrated on a part of the aluminum plate and so-called “burn” does not occur.²30 to 50 A / dm as the anodizing process proceeds at a low current density of²Alternatively, it is preferable to increase the current density further.
When the anodizing treatment is continuously performed, it is preferable that the anodizing process is performed by a liquid power feeding method in which power is supplied to the aluminum plate through an electrolytic solution.
By performing anodizing treatment under such conditions, a porous film having many pores called micropores can be obtained. Usually, the average pore diameter is about 5 to 50 nm, and the average pore density is 300. ~ 800 / μm²Degree.
[0084]
The amount of anodized film is 1-5g / m²Is preferred. 1g / m²If it is less than 5%, the plate is likely to be damaged, while 5 g / m.²Exceeding this requires a large amount of power for production, which is economically disadvantageous. The amount of anodized film is 1.5-4 g / m²It is more preferable that Further, the difference in the amount of the anodized film between the center portion of the aluminum plate and the vicinity of the edge portion is 1 g / m.²It is preferable to carry out as follows.
[0085]
As the electrolysis apparatus used for the anodizing treatment, those described in JP-A-48-26638, JP-A-47-18739, JP-B-58-24517, and the like can be used.
Among these, the apparatus shown in FIG. 4 is preferably used. FIG. 4 is a schematic view showing an example of an apparatus for anodizing the surface of an aluminum plate. In the anodizing apparatus 410, the aluminum plate 416 is transported as indicated by arrows in FIG. In the power supply tank 412 in which the electrolytic solution 418 is stored, the aluminum plate 416 is charged to (+) by the power supply electrode 420. The aluminum plate 416 is conveyed upward by the roller 422 in the power supply tank 412, changed in direction downward by the nip roller 424, and then conveyed toward the electrolytic treatment tank 414 in which the electrolytic solution 426 is stored. The direction is changed horizontally. Next, the aluminum plate 416 is charged to (−) by the electrolytic electrode 430 to form an anodized film on the surface thereof, and the aluminum plate 416 exiting the electrolytic treatment tank 414 is conveyed to a subsequent process. In the anodizing apparatus 410, the roller 422, the nip roller 424, and the roller 428 constitute a direction changing means, and the aluminum plate 416 is disposed between the power supply tank 412 and the electrolytic treatment tank 414 in the inter-tank section. By 428, it is conveyed into a mountain shape and an inverted U shape. The feeding electrode 420 and the electrolytic electrode 430 are connected to a DC power source 434.
[0086]
A feature of the anodizing apparatus 410 in FIG. 4 is that the feeding tank 412 and the electrolytic treatment tank 414 are partitioned by a single tank wall 432, and the aluminum plate 416 is conveyed in a mountain shape and an inverted U shape between the tanks. It is in. As a result, the length of the aluminum plate 416 in the inter-tank portion can be minimized. Therefore, the overall length of the anodizing apparatus 410 can be shortened, so that the equipment cost can be reduced. In addition, by conveying the aluminum plate 416 in a mountain shape and an inverted U shape, it is not necessary to form an opening for allowing the aluminum plate 416 to pass through the tank walls of the tanks 412 and 414. Therefore, since the liquid feeding amount required to maintain the liquid level height in each tank 412 and 414 at a required level can be suppressed, the operating cost can be reduced.
[0087]
<Sealing treatment>
In this invention, you may perform the sealing process which seals the micropore which exists in an anodic oxide film as needed. The sealing treatment can be performed according to a known method such as boiling water treatment, hot water treatment, steam treatment, sodium silicate treatment, nitrite treatment, ammonium acetate treatment and the like. For example, Japanese Patent Publication No. 56-12518, Japanese Patent Application Laid-Open No. 4-4194, Japanese Patent Application No. 4-33952 (Japanese Patent Application Laid-Open No. 5-202496), Japanese Patent Application No. 4-33951 (Japanese Patent Application Laid-Open No. -179482) etc. may be used for sealing treatment.
[0088]
<Hydrophilic treatment>
A hydrophilization treatment may be performed after the anodizing treatment or the sealing treatment. Examples of the hydrophilization treatment include treatment with potassium fluorinated zirconate described in US Pat. No. 2,946,638 and phosphomolybdate described in US Pat. No. 3,201,247. Treatment, alkyl titanate treatment described in British Patent 1,108,559, polyacrylic acid treatment described in German Patent 1,091,433, German Patent 1,134, No. 093 and British Patent No. 1,230,447, polyvinyl phosphonic acid treatment, Japanese Patent Publication No. 44-6409, phosphonic acid treatment, US Pat. No. 3,307,951 Phytic acid treatment described in the specification of JP, No. 58-16893 and JP-A No. 58-18291 Treatment with a salt of a molecular compound and a divalent metal, as described in US Pat. No. 3,860,426, hydrophilic cellulose (eg, zinc acetate) containing a water-soluble metal salt (eg, zinc acetate) Carboxymethyl cellulose) is provided with a subbing layer, and a water-soluble polymer having a sulfo group described in JP-A-59-101651.
[0089]
Further, phosphates described in JP-A No. 62-019494, water-soluble epoxy compounds described in JP-A No. 62-033692, and JP-A No. 62-097892 Phosphate-modified starch, diamine compounds described in JP-A-63-056498, amino acid inorganic or organic acids described in JP-A-63-130391, JP-A-63-145092 Organic phosphonic acids containing carboxy group or hydroxy group, compounds having amino group and phosphonic acid group described in JP-A-63-165183, and JP-A-2-316290 Specific carboxylic acid derivatives, phosphate esters described in JP-A-3-215095, JP-A-3-261592 Compounds having one amino group and one oxygen acid group of phosphorus described in the publication, phosphoric esters described in JP-A-3-215095, and JP-A-5-246171 Aliphatic or aromatic phosphonic acids such as phenylphosphonic acid, compounds containing S atoms such as thiosalicylic acid described in JP-A-1-307745, and phosphorus described in JP-A-4-282737 Examples of the treatment include undercoating using a compound having a group of oxygen acids.
Further, coloring with an acid dye described in JP-A-60-64352 can also be performed.
[0090]
Hydrophilicity can also be achieved by soaking in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or by applying a hydrophilic vinyl polymer or hydrophilic compound to form a hydrophilic primer layer. It is preferable to carry out the treatment.
[0091]
Hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. It can be performed according to methods and procedures.
Examples of the alkali metal silicate include sodium silicate, potassium silicate, and lithium silicate. The aqueous solution of alkali metal silicate may contain an appropriate amount of sodium hydroxide, potassium hydroxide, lithium hydroxide or the like.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVA) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Examples of the Group 4 (Group IVA) metal salt include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVA) metal salts are used alone or in combination of two or more.
[0092]
The amount of Si adsorbed by the alkali metal silicate treatment can be measured with a fluorescent X-ray analyzer, and the amount of adsorption is about 1.0 to 15.0 mg / m.²Is preferred.
By this alkali metal silicate treatment, the effect of improving the dissolution resistance to the alkaline developer on the surface of the lithographic printing plate support is obtained, the dissolution of the aluminum component into the developer is suppressed, and the developer fatigue It is possible to reduce the occurrence of development residue due to the above.
[0093]
The hydrophilization treatment by forming a hydrophilic undercoat layer can also be performed according to the conditions and procedures described in JP-A Nos. 59-101651 and 60-149491.
Examples of the hydrophilic vinyl polymer used in this method include polyvinyl sulfonic acid, sulfo group-containing vinyl polymerizable compounds such as p-styrene sulfonic acid having a sulfo group, and ordinary vinyl polymerization such as (meth) acrylic acid alkyl ester. And a copolymer with a functional compound. Moreover, as a hydrophilic compound used for this method, for example, —NH₂And a compound having at least one selected from the group consisting of a group, a —COOH group and a sulfo group.
[0094]
<Washing treatment>
It is preferable to perform water washing after the completion of the above-described processes. For washing, pure water, well water, tap water, or the like can be used. A nip device may be used to prevent the processing liquid from being brought into the next process.
[0095]
<Aluminum plate (rolled aluminum)>
In order to obtain the lithographic printing plate support of the present invention, a known aluminum plate can be used. The aluminum plate used in the present invention is a metal whose main component is dimensionally stable aluminum, and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements can also be used.
[0096]
In the present specification, various substrates made of the above-described aluminum or aluminum alloy are generically used as an aluminum plate. The foreign elements that may be contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium, and the content of the foreign elements in the alloy is 10% by mass or less. It is.
[0097]
Thus, the composition of the aluminum plate used in the present invention is not specified. For example, a conventionally known material described in the fourth edition of the Aluminum Handbook (1990, published by the Light Metal Association), for example, JIS Al-Mn based aluminum plates such as A1050, JISA1100, JIS A1070, JIS A3004 containing Mn, and internationally registered alloy 3103A can be appropriately used. For the purpose of increasing the tensile strength, an Al—Mg alloy or an Al—Mn—Mg alloy (JIS A3005) in which 0.1 mass% or more of magnesium is added to these aluminum alloys can also be used. Furthermore, an Al—Zr alloy or an Al—Si alloy containing Zr or Si can also be used. Furthermore, an Al—Mg—Si based alloy can also be used.
[0098]
Regarding the JIS 1050 material, the techniques proposed by the applicant of the present application are disclosed in Japanese Patent Application Laid-Open Nos. 59-153861, 61-51395, 62-146694, 60-215725, and 60-215725. JP 60-215726, JP 60-215727, JP 60-216728, JP 61-272367, JP 58-11759, JP 58-42493, JP 58- 221254, JP-A-62-148295, JP-A-4-254545, JP-A-4-165541, JP-B-3-68939, JP-A-3-234594, JP-B-1-47545, and JP-A-62. It is described in each publication of -140894. In addition, techniques described in Japanese Patent Publication No. 1-35910 and Japanese Patent Publication No. 55-28874 are also known.
[0099]
Regarding the JIS1070 material, the techniques proposed by the applicant of the present application are disclosed in JP-A-7-81264, JP-A-7-305133, JP-A-8-49034, JP-A-8-73974, JP-A-8-108659 and It is described in JP-A-8-92679.
[0100]
Regarding Al-Mg alloys, the techniques proposed by the applicant of the present application are disclosed in Japanese Patent Publication Nos. Sho 62-5080, Sho 63-60823, Shoko 3-61753, JP Sho 60-20396, JP-A-60-203497, JP-B-3-11635, JP-A-61-274993, JP-A-62-23794, JP-A-63-47347, JP-A-63-47348, JP-A-63-47349. JP-A 64-1293, JP-A 63-135294, JP-A 63-87288, JP-B 4-73392, JP-B 7-100844, JP-A 62-149856, JP-B JP-A-4-73394, JP-A-62-181191, JP-B-5-76530, JP-A-63-30294, and JP-B-6-37116. Also described in JP-A-2-215599, JP-A-61-201747, and the like.
[0101]
With regard to Al—Mn alloys, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 60-230951, 1-306288, and 2-293189. In addition, JP-B-54-42284, JP-B-4-19290, JP-B-4-19291, JP-B-4-19292, JP-A-61-35995, JP-A-64-51992, JP-A-4-19592, No. 226394, US Pat. No. 5,009,722, US Pat. No. 5,028,276 and the like.
[0102]
With regard to the Al—Mn—Mg alloy, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 62-86143 and 3-2222796. JP-B 63-60824, JP-A 60-63346, JP-A 60-63347, JP-A-1-293350, European Patent No. 223,737, US Pat. No. 4,818, No. 300, British Patent No. 1,222,777, etc.
[0103]
Regarding the Al—Zr alloy, the technique proposed by the applicant of the present application is described in Japanese Patent Publication No. 63-15978 and Japanese Patent Application Laid-Open No. 61-51395. Also described in JP-A-63-143234 and JP-A-63-143235.
[0104]
The Al—Mg—Si alloy is described in British Patent 1,421,710.
[0105]
In order to use an aluminum alloy as a plate material, for example, the following method can be employed. First, a molten aluminum alloy adjusted to a predetermined alloy component content is subjected to a cleaning process and cast according to a conventional method. In the cleaning process, in order to remove unnecessary gas such as hydrogen in the molten metal, flux treatment, degassing process using argon gas, chlorine gas, etc., so-called rigid media filter such as ceramic tube filter, ceramic foam filter, A filtering process using a filter that uses alumina flakes, alumina balls or the like as a filter medium, a glass cloth filter, or a combination of a degassing process and a filtering process is performed.
[0106]
These cleaning treatments are preferably performed in order to prevent defects caused by foreign matters such as non-metallic inclusions and oxides in the molten metal and defects caused by gas dissolved in the molten metal. Regarding filtering of the molten metal, JP-A-6-57432, JP-A-3-162530, JP-A-5-140659, JP-A-4-231425, JP-A-4-276031, JP-A-5-311261, JP-A-5-311261 6-136466 and the like. Further, the degassing of the molten metal is described in JP-A-5-51659, Japanese Utility Model Laid-Open No. 5-49148, and the like. The applicant of the present application has also proposed a technique relating to degassing of molten metal in Japanese Patent Application Laid-Open No. 7-40017.
[0107]
Next, casting is performed using the molten metal that has been subjected to the cleaning treatment as described above. Regarding the casting method, there are a method using a solid mold typified by a DC casting method and a method using a driving mold typified by a continuous casting method.
In DC casting, solidification occurs at a cooling rate of 0.5 to 30 ° C./second. When the temperature is less than 1 ° C., many coarse intermetallic compounds may be formed. When DC casting is performed, an ingot having a thickness of 300 to 800 mm can be manufactured. The ingot is chamfered as necessary according to a conventional method, and usually 1 to 30 mm, preferably 1 to 10 mm, of the surface layer is cut. Before and after that, soaking treatment is performed as necessary. When performing a soaking treatment, heat treatment is performed at 450 to 620 ° C. for 1 to 48 hours so that the intermetallic compound does not become coarse. If the heat treatment is shorter than 1 hour, the effect of soaking may be insufficient.
[0108]
Then, hot rolling and cold rolling are performed to obtain a rolled aluminum plate. An appropriate starting temperature for hot rolling is 350 to 500 ° C. An intermediate annealing treatment may be performed before or after hot rolling or in the middle thereof. The conditions for the intermediate annealing treatment are heating at 280 to 600 ° C. for 2 to 20 hours, preferably 350 to 500 ° C. for 2 to 10 hours using a batch annealing furnace, or 400 to 600 ° C. using a continuous annealing furnace. Heating is performed for 6 minutes or less, preferably 450 to 550 ° C. for 2 minutes or less. The crystal structure can be made finer by heating at a heating rate of 10 to 200 ° C./second using a continuous annealing furnace.
[0109]
The flatness of the aluminum plate finished to a predetermined thickness, for example, 0.1 to 0.5 mm by the above steps may be further improved by a correction device such as a roller leveler or a tension leveler. The flatness may be improved after the aluminum plate is cut into a sheet shape, but in order to improve the productivity, it is preferably performed in a continuous coil state. Further, a slitter line may be used for processing into a predetermined plate width. Moreover, in order to prevent generation | occurrence | production of the damage | wound by friction between aluminum plates, you may provide a thin oil film on the surface of an aluminum plate. As the oil film, a volatile or non-volatile film is appropriately used as necessary.
[0110]
On the other hand, as the continuous casting method, a twin roll method (hunter method), a method using a cooling roll typified by the 3C method, a double belt method (Hazley method), a cooling belt or a cooling block typified by Al-Swiss Caster II type The method using is industrially performed. When the continuous casting method is used, it solidifies at a cooling rate of 100 to 1000 ° C./second. Since the continuous casting method generally has a higher cooling rate than the DC casting method, it has a feature that the solid solubility of the alloy component in the aluminum matrix can be increased. Regarding the continuous casting method, the techniques proposed by the applicant of the present application are disclosed in JP-A-3-79798, JP-A-5-201166, JP-A-5-156414, JP-A-6-262203, and JP-A-6-122949. JP-A-6-210406 and JP-A-6-26308.
[0111]
When continuous casting is performed, for example, if a method using a cooling roll such as a Hunter method is used, a cast plate having a thickness of 1 to 10 mm can be directly cast continuously, and the hot rolling step is omitted. The advantage of being able to In addition, when a method using a cooling belt such as the Husley method is used, a cast plate having a thickness of 10 to 50 mm can be cast. Generally, a hot rolling roll is arranged immediately after casting and continuously rolled. Thus, a continuous cast and rolled plate having a thickness of 1 to 10 mm is obtained.
[0112]
These continuous cast and rolled plates are subjected to processes such as cold rolling, intermediate annealing, improvement of flatness, slits, and the like in the same manner as described for DC casting. Finished to a thickness of 5 mm. Regarding the intermediate annealing condition and the cold rolling condition when using the continuous casting method, the techniques proposed by the applicant of the present application are disclosed in JP-A-6-220593, JP-A-6-210308, JP-A-7-54111, It is described in JP-A-8-92709.
[0113]
Various characteristics described below are desired for the aluminum plate thus manufactured.
As for the strength of the aluminum plate, it is preferable that the 0.2% proof stress is 140 MPa or more in order to obtain the stiffness required for a lithographic printing plate support. Moreover, in order to obtain a certain level of waist strength even when performing a burning treatment, the 0.2% yield strength after heat treatment at 270 ° C. for 3 to 10 minutes is preferably 80 MPa or more, and 100 MPa or more. It is more preferable that In particular, when the waist strength is required for an aluminum plate, an aluminum material added with Mg or Mn can be used, but if the waist is strengthened, the ease of fitting to the plate cylinder of a printing press becomes inferior. Depending on the application, the material and the amount of trace components added are appropriately selected. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 7-126820 and 62-140894.
[0114]
The crystal structure of the aluminum plate may cause poor surface quality when the surface of the aluminum plate is subjected to chemical or electrochemical surface roughening. It is preferably not too coarse. The crystal structure on the surface of the aluminum plate preferably has a width of 200 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, and the length of the crystal structure is 5000 μm or less. Is preferably 1000 μm or less, and more preferably 500 μm or less. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 6-218495, 7-39906, and 7-124609.
[0115]
The alloy component distribution of the aluminum plate, when chemical surface roughening treatment or electrochemical surface roughening treatment is performed, poor surface quality occurs due to non-uniform distribution of the alloy component on the surface of the aluminum plate. Therefore, it is preferable that the surface is not very uneven. With regard to these, the techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 6-48058, 5-301478, and 7-132689.
[0116]
In the intermetallic compound of the aluminum plate, the size and density of the intermetallic compound may affect the chemical roughening treatment or the electrochemical roughening treatment. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 7-138687 and 4-254545.
[0117]
In the present invention, an aluminum plate as shown above can be used with unevenness by lamination rolling, transfer or the like in the final rolling step.
[0118]
The aluminum plate used in the present invention is a continuous belt-like sheet material or plate material. That is, it may be an aluminum web or a sheet-like sheet cut to a size corresponding to a planographic printing plate precursor shipped as a product.
Since scratches on the surface of the aluminum plate may become defects when processed into a lithographic printing plate support, it is possible to generate scratches at the stage prior to the surface treatment process for making a lithographic printing plate support It is necessary to suppress as much as possible. For that purpose, it is preferable that the package has a stable form and is not easily damaged during transportation.
In the case of an aluminum web, for example, the packing form of aluminum is, for example, laying a hardboard and felt on an iron pallet, applying cardboard donut plates to both ends of the product, wrapping the whole with a polytube, and inserting a wooden donut into the inner diameter of the coil Then, a felt is applied to the outer periphery of the coil, the band is squeezed with a band, and the display is performed on the outer periphery. Moreover, a polyethylene film can be used as the packaging material, and a needle felt or a hard board can be used as the cushioning material. There are various other forms, but the present invention is not limited to this method as long as it is stable and can be transported without being damaged.
[0119]
The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and more preferably 0.2 mm to 0.3 mm. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, the user's desires, and the like.
[0120]
[Lithographic printing plate precursor]
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 exemplified below to form the lithographic printing plate precursor of the present invention. 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.
[0121]
<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.
Furthermore, the photosensitive resin composition includes compounds such as sensitivity modifiers, printing agents, dyes and the like 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 coatability as described.
[0122]
<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, the photosensitive resin composition is imparted with the flexibility and abrasion resistance of the printing agent, dye, and coating film described in [0014] to [0015] of JP-A-7-281425. It is preferable to add a compound such as a plasticizer or a development accelerator, or a surfactant for improving coating properties.
As the undercoat layer of the conventional positive or negative photosensitive layer described above, a polymer having a component having an acid group and a component having an onium group described in JP-A-2000-105462 It is preferable to provide an intermediate layer containing the compound.
[0123]
<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.
[0124]
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 adhesive layer or undercoat layer as described in [0131] to [0165] of JP-A-2001-228608 as the lower layer of the photosensitive layer.
[0125]
<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.
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 the coating property 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.
As the single heat-sensitive layer, for example, a heat-sensitive layer described in International Publication No. 97/39894 pamphlet and Japanese Patent Laid-Open No. 10-268512 can be used. As the heat-sensitive layer having a two-layer structure, for example, heat-sensitive layers described in International Publication No. 99/67097 pamphlet and European Patent No. 864,420 can be used.
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].
[0126]
<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 the (A) infrared absorber include the photothermal conversion substance contained in the above-described thermal positive type heat-sensitive layer. In particular, specific examples of cyanine dyes are disclosed in JP-A-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).
[0127]
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.
[0128]
<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.
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.
[0129]
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 the same dye as the dye used for the above-described thermal positive type is particularly preferable.
[0130]
<Back coat layer>
In this way, on the back surface of the lithographic printing plate precursor of the present invention obtained by providing various image recording layers on the lithographic printing plate support of the present invention, an image in the case of being overlaid as necessary. In order to prevent the recording layer from being scratched, a backcoat layer made of an organic polymer compound can be provided.
[0131]
<Method for producing planographic printing plate precursor>
Each layer such as an image recording layer can usually be produced by applying a coating solution obtained by dissolving the above components in a solvent onto a lithographic printing plate support.
Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to these. These solvents are used alone or in combination.
The concentration of the above components (total solid content) in the solvent is preferably 1 to 50% by mass.
[0132]
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.
[0133]
<Method for producing planographic 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 in the lithographic printing plate precursor according to the invention is not particularly limited as long as it is an alkaline developer, but an alkaline aqueous solution substantially free of 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. . The lithographic printing plate precursor according to the invention can also be developed using a developer containing an alkali metal silicate.
[0134]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
1. Making a support for planographic printing plates
(Examples 1-8 and Comparative Examples 1-5)
<Aluminum plate>
Each aluminum plate containing the different elements shown in Table 1 was subjected to the following surface treatment.
[0135]
[Table 1]

[0136]
<Surface treatment>
Various surface treatments of the following (a) to (k) are continuously performed on the aluminum plate in the combinations shown in Table 2 to obtain lithographic printing plate supports of Examples 1 to 8 and Comparative Examples 1 to 5. It was. After each treatment and water washing, the liquid was drained with a nip roller.
In Table 2, “-” indicates that the corresponding surface treatment was not performed.
[0137]
[Table 2]

[0138]
Hereinafter, each of the surface treatments (a) to (k) will be described.
(A) Mechanical roughening treatment (brush grain method)
Using an apparatus as schematically shown in FIG. 1, an aqueous suspension of abrasive (pumice) (specific gravity 1.1 g / cm)³) Was supplied to the surface of the aluminum plate as a polishing slurry liquid, and a mechanical surface roughening treatment was performed with a rotating roller nylon brush. In FIG. 1, 1 is an aluminum plate, 2 and 4 are roller-like brushes (in this embodiment, bundle-planting brush), 3 is a polishing slurry, and 5, 6, 7 and 8 are support rollers. The mechanical surface roughening treatment was performed under either condition B-1 or B-2 shown in Table 3.
The median diameter of the abrasive was as shown in Table 3. The material of the nylon brush was 6 · 10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel cylinder having a diameter of 400 mm. Although only two rotating brushes are shown in FIG. 1, the numbers shown in Table 3 were actually used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 10 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The number of rotations of the brush was as shown in Table 3. In addition, the rotation speed of the brush in Table 3 represented the brush as the 1st, 2nd, 3rd in order from the conveyance direction upstream of the aluminum plate.
[0139]
[Table 3]

[0140]
(B) Alkali etching treatment
The alkali etching treatment was performed under any of the conditions E-1 to E-8 shown in Table 4.
Specifically, an etching process was performed with an aluminum dissolution amount shown in Table 4 by spraying using a caustic soda aqueous solution having a caustic soda concentration and an aluminum ion concentration shown in Table 4. Then, water washing by spraying was performed. The temperature for the alkali etching treatment was 70 ° C.
[0141]
[Table 4]

[0142]
(C) Desmut treatment
The desmut treatment was performed under any of the conditions D-1 to D-3 shown in Table 5.
Specifically, desmutting treatment was carried out by spraying with an acid aqueous solution of the kind shown in Table 5, temperature and concentration, and then washing with water was carried out by spraying. In addition, as the nitric acid aqueous solution used for the condition D-1, the waste liquid of the process which performs an electrochemical roughening process using alternating current in nitric acid aqueous solution was used.
[0143]
[Table 5]

[0144]
(D) Electrochemical roughening treatment
The electrochemical surface roughening treatment was performed under any of the conditions C-1 to C-3 shown in Table 6 and the conditions M-1 to M-3 shown in Table 7. Specifically, it was performed as follows.
(D-1) Nitric acid electrolysis (Conditions C-1 to C-3)
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power supply waveform is the waveform shown in FIG. 2, the time TP until the current value reaches the peak from zero is 0.8 msec, the duty ratio is 1: 1, a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 3 was used.
The current density is 30 A / dm at the peak current value.²The auxiliary anode was shunted with 5% of the current flowing from the power source. The amount of electricity in the nitric acid electrolysis was set to the value shown in Table 6 as the total amount of electricity when the aluminum plate was an anode.
Then, water washing by spraying was performed.
[0145]
[Table 6]

[0146]
(D-2) Hydrochloric acid electrolysis (Conditions M-1 to M-3)
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The liquid temperature was 50 ° C. The AC power supply waveform is the waveform shown in FIG. 2, the time TP until the current value reaches the peak from zero is 0.8 msec, the duty ratio is 1: 1, a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 3 was used.
The current density is 25 A / dm at the peak current value.²Met.
The electrolyte used for hydrochloric acid electrolysis was an aqueous solution of hydrochloric acid concentration shown in Table 7 (containing 0.5 mass% of aluminum ions). The amount of electricity in hydrochloric acid electrolysis was the sum of the amount of electricity when the aluminum plate was the anode. The values shown in Table 7 were used.
Then, water washing by spraying was performed.
[0147]
[Table 7]

[0148]
(E) Alkali etching treatment
The alkali etching treatment was performed under any of the conditions E-1 to E-8 shown in Table 4. Then, water washing by spraying was performed.
[0149]
(F) Desmut treatment
The desmut treatment was performed under any of the conditions D-1 to D-3 shown in Table 5. Then, water washing by spraying was performed.
[0150]
(G) Electrochemical roughening treatment
The electrochemical surface roughening treatment was performed under any of the conditions C-1 to C-3 shown in Table 6 and the conditions M-1 to M-3 shown in Table 7. Then, water washing by spraying was performed.
[0151]
(H) Alkali etching treatment
The alkali etching treatment was performed under any of the conditions E-1 to E-8 shown in Table 4. Then, water washing by spraying was performed.
[0152]
(I) Desmut treatment
The desmut treatment was performed under any of the conditions D-1 to D-3 shown in Table 5. Then, water washing by spraying was performed.
[0153]
(J) Anodizing treatment
The anodizing treatment was performed under the following condition A-1.
<Condition A-1>
Anodization was performed using a direct current electrolysis anodizing apparatus having the structure shown in FIG. 4 to obtain a support for a lithographic printing plate. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 15% by mass (containing 0.5% by mass of aluminum ions) and a temperature of 38 ° C. Then, water washing by spraying was performed. The final oxide film amount is 2.5 g / m²Met.
[0154]
(K) Silicate processing
The silicate treatment was performed under the following condition S-1.
<Condition S-1>
No. 3 sodium silicate aqueous solution (Na₂O: SiO₂= 1: 3, SiO₂The content was 30% by mass, manufactured by Nippon Chemical Industry Co., Ltd., concentration 1% by mass) for 10 seconds. Then, the water washing by the spray using well water was performed.
[0155]
2. Calculation of surface shape factor of lithographic printing plate support
About the surface of the lithographic printing plate support obtained above, ΔS⁵⁰, A45^{50 (0.2-2)}, ΔS^{5 (0.02-0.2)}And a45^{5 (0.02-0.2)}Asked.
The results are shown in Table 8.
[0156]
(1) Surface shape measurement by atomic force microscope
ΔS⁵⁰, A45^{50 (0.2-2)}, ΔS^{5 (0.02-0.2)}And a45^{5 (0.02-0.2)}Therefore, the surface shape was measured with an atomic force microscope (SPA300 / SPI3800N, manufactured by Seiko Instruments Inc.) to obtain three-dimensional data.
The planographic printing plate support is cut to a size of 1 cm square, set on a horizontal sample stage on a piezo scanner, and the cantilever is approached to the sample surface. Scanning was performed, and the unevenness of the sample was captured by the displacement of the piezo in the Z direction. A piezo scanner that can scan 150 μm in the XY direction and 10 μm in the Z direction was used. A cantilever having a resonance frequency of 120 to 400 kHz and a spring constant of 12 to 90 N / m (SI-DF20, manufactured by Seiko Instruments Inc.) was used and measured in a DFM mode (Dynamic Force Mode). Further, the reference plane was obtained by correcting the slight inclination of the sample by least-square approximation of the obtained three-dimensional data.
When measuring, ΔS⁵⁰And a45^{50 (0.2-2)}For, the surface of 50 μm square was measured at 512 × 512 points. The resolution in the XY direction was 0.1 μm, the resolution in the Z direction was 0.15 nm, and the scan speed was 50 μm / sec.
ΔS^{5 (0.02-0.2)}And a45^{5 (0.02-0.2)}For the surface, 512 × 512 points of 5 μm square on the surface were measured. The resolution in the XY direction was 0.01 μm, the resolution in the Z direction was 0.15 nm, and the scan speed was 5 μm / sec.
[0157]
(2) Correction of 3D data
ΔS⁵⁰For the calculation, three-dimensional data based on the measurement of 50 μm square of the surface obtained in the above (1) was used as it was.
a45^{50 (0.2-2)}For the calculation, a component obtained by extracting a component having a wavelength of 0.2 μm or more and 2 μm or less from three-dimensional data based on the measurement of 50 μm □ of the surface obtained in (1) above was used. Extraction of components having a wavelength of 0.2 μm or more and 2 μm or less is performed by performing a fast Fourier transform on the three-dimensional data obtained in (1) above to obtain a frequency distribution, and then a component having a wavelength less than 0.2 μm and a wavelength exceeding 2 μm. After removing the components, the inverse Fourier transform was performed.
ΔS^{5 (0.02-0.2)}And a45^{5 (0.02-0.2)}For the calculation, a component obtained by extracting a component having a wavelength of 0.02 μm or more and 0.2 μm or less from three-dimensional data based on the measurement of 5 μm □ of the surface obtained in (1) above was used. Extraction of components having a wavelength of 0.02 μm or more and 0.2 μm or less is performed by performing a fast Fourier transform on the three-dimensional data obtained in (1) above to obtain a frequency distribution, and then a component having a wavelength of less than 0.02 μm and a wavelength of 0 After removing components exceeding 2 μm, the inverse Fourier transform was performed.
[0158]
(3) Calculation of each factor
▲ 1 ▼ ΔS⁵⁰
Using the three-dimensional data (f (x, y)) obtained in (1) above, three adjacent points are extracted, the sum of the areas of the minute triangles formed by the three points is obtained, and the actual area S_x ⁵⁰It was. Surface area ratio ΔS⁵⁰Is the actual area S obtained_x ⁵⁰And geometric measurement area S₀ ⁵⁰From the above, it was determined by the above formula (1).
[0159]
▲ 2 ▼ a45^{50 (0.2-2)}
Using three-dimensional data (f (x, y)) obtained by correcting in (2) above, each reference point is formed by three points in the predetermined direction (for example, right and bottom). The angle formed between the small triangle formed and the reference plane was calculated for each reference point. The number of reference points where the inclination of the micro triangle is 45 degrees or more is obtained by subtracting the number of all reference points (the number of all data 512 × 512 points from the number of points that do not have two adjacent points in a predetermined direction). I.e., 511 × 511 points), and the area ratio a45 of the portion having the inclination of 45 degrees or more.^{50 (0.2-2)}Was calculated.
[0160]
(3) ΔS^{5 (0.02-0.2)}
Using the three-dimensional data (f (x, y)) obtained by correcting in (2) above, three adjacent points are extracted, and the total area of the micro triangles formed by the three points is obtained. Area S_x ^{5 (0.02-0.2)}It was. Surface area ratio ΔS^{5 (0.02-0.2)}Is the actual area S obtained_x ^{5 (0.02-0.2)}And geometric measurement area S₀ ⁵From the above, it was determined by the above formula (2).
[0161]
▲ 4 ▼ a45^{5 (0.02-0.2)}
Using three-dimensional data (f (x, y)) obtained by correcting in (2) above, each reference point is formed by three points in the predetermined direction (for example, right and bottom). The angle formed between the small triangle formed and the reference plane was calculated for each reference point. The number of reference points where the inclination of the micro triangle is 45 degrees or more is obtained by subtracting the number of all reference points (the number of all data 512 × 512 points from the number of points that do not have two adjacent points in a predetermined direction). I.e., 511 × 511 points), and the area ratio a45 of the portion having the inclination of 45 degrees or more.^{5 (0.02-0.2)}Was calculated.
[0162]
In addition, the number of local deep portions having a depth of 4 μm or more existing on the surface is scanned with a resolution of 0.01 μm on a surface of 400 μm × 400 μm in a non-contact manner using a laser microscope (Micromap 520, manufactured by Ryoka System Co., Ltd.). Thus, three-dimensional data was obtained, and the number of recesses having a depth of 4 μm or more was counted in the three-dimensional data. The measurement was performed at five points per sample, and the average value was obtained.
As the laser microscope, in addition to the one used above, for example, an ultra-deep shape measuring microscope VK5800 manufactured by KEYENCE can be used in the same manner.
[0163]
3. Creating a lithographic printing plate precursor
Each of the lithographic printing plate supports obtained above was provided with either of the thermal positive type image recording layers A and B as follows to obtain a lithographic printing plate precursor. Before providing the image recording layers A and B, an undercoat layer was provided as described later.
[0164]
<Formation of undercoat layer>
On the lithographic printing plate support after the silicate treatment, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form a coating film of the undercoat layer. The coating amount of the coating after drying is 10 mg / m²Met.
[0165]
<Undercoat liquid composition>
・ The following polymer compound 0.2g
・ Methanol 100g
・ Water 1g
[0166]
[Chemical 1]

[0167]
<Formation of image recording layer A>
The image recording layer A is a single-layer thermal positive type image recording layer, and was formed as follows.
A heat-sensitive layer coating solution having the following composition was prepared, and the coating amount after drying the heat-sensitive layer coating solution (heat-sensitive layer coating amount) on a lithographic printing plate support provided with an undercoat layer was 1.7 g / m.²And dried to form a heat-sensitive layer (single-layer thermal positive type image recording layer) to obtain a lithographic printing plate precursor.
[0168]
<Thermosensitive layer coating solution composition>
・ Novolak resin (m-cresol / p-cresol = 60/40, weight average molecular weight 7,000, containing 0.5% by mass of unreacted cresol) 1.0 g
-Cyanine dye A 0.1 g represented by the following structural formula
・ Tetrahydrophthalic anhydride 0.05g
・ 0.002 g of p-toluenesulfonic acid
-Ethyl violet counter ion with 6-hydroxy-β-naphthalenesulfonic acid 0.02 g
-Fluorosurfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0.05g
・ Methyl ethyl ketone 12g
[0169]
[Chemical 2]

[0170]
<Formation of image recording layer B>
The image recording layer B is a multi-layered thermal positive type image recording layer, and was formed as follows.
A coating solution for the first layer having the following composition was prepared, and the coating amount after drying the coating solution for the first layer was 0.85 g / m on the lithographic printing plate support on which the undercoat layer was formed.²It was applied so that the wind control was set to 7 using PERFECT OVEN PH200 manufactured by Tabai Co., Ltd. and dried at 140 ° C. for 50 seconds to form the first layer. Next, a coating solution for the second layer having the following composition was prepared, and the coating amount after drying the coating solution for the second layer was 0.15 g / m on the lithographic printing plate support on which the first layer was formed.²And a second layer was formed by drying at 120 ° C. for 60 seconds to obtain a lithographic printing plate precursor having a multilayer thermal positive type image recording layer.
[0171]
<Coating solution composition for first layer>
N- (4-aminosulfonylphenyl) methacrylamide / acrylonitrile / methyl methacrylate (molar ratio 36/34/30, weight average molecular weight 50,000, acid value 2.65) 2.133 g
-Cyanine dye A represented by the above formula 0.109 g
・ 4,4'-bishydroxyphenylsulfone 0.126g
・ Tetrahydrophthalic anhydride 0.190g
・ 0.008 g of p-toluenesulfonic acid
・ 3-methoxy-4-diazodiphenylamine hexafluorophosphate 0.030 g
・ The counter ion of ethyl violet is changed to 6-hydroxynaphthalene sulfone 0.10 g
-Fluorosurfactant (Megafac F-176, manufactured by Dainippon Ink & Chemicals, 20% by weight solution, for improving coated surface) 0.035 g (as a solution)
・ Methyl ethyl ketone 25.38g
・ 13.0 g of 1-methoxy-2-propanol
・ Γ-butyrolactone 13.2 g
[0172]
<Coating solution composition for second layer>
-M, p-cresol-novolak resin (m / p ratio = 6/4, weight average molecular weight 4,500, containing 0.8% by mass of unreacted cresol) 0.2846 g
-Cyanine dye A represented by the above formula 0.075 g
・ Behenamide 0.060g
-Fluorosurfactant (Megafac F-176, manufactured by Dainippon Ink & Chemicals, Inc., 20% by mass solution, for improving coating surface condition) 0.022 g (as a solution)
-Fluorosurfactant (Megafac MCF-312, manufactured by Dainippon Ink and Chemicals, 30% by weight solution, for image formation improvement) 0.120 g (as a solution)
・ Methyl ethyl ketone 15.1g
-1-methoxy-2-propanol 7.7g
[0173]
4). Exposure and development processing
Each lithographic printing plate precursor obtained above was subjected to image exposure and development treatment by the following methods to obtain a lithographic printing plate.
[0174]
A lithographic printing plate precursor has an output of 500 mW, a wavelength of 830 nm, a beam diameter of 17 μm (1 / e²) Using a TrendSetter 3244 manufactured by CREO equipped with a semiconductor laser, a main scanning speed of 5 m / sec, and a plate surface energy amount of 140 mJ / cm.²And imagewise exposure. In order to evaluate the pot-like residual film described later, the plate surface energy amount is 20 to 140 mJ / cm.²Up to 20 mJ / cm²Samples subjected to exposure at different intervals were prepared.
Thereafter, D-sorbite / potassium oxide K, which is a combination of a non-reducing sugar and a base₂To 1 L of an aqueous solution containing 5.0% by mass of a potassium salt composed of O and 0.015% by mass of Olphine AK-02 (manufactured by Nissin Chemical)₁₂H₂₅N (CH₂CH₂COONa)₂Development processing was performed using an alkaline developer (Developer 1) to which 1.0 g was added. The development processing was performed using an automatic processor PS900NP (Fuji Photo Film Co., Ltd.) filled with the developer 1 at a development temperature of 25 ° C. for 12 seconds. After completion of the development treatment, a lithographic printing plate in which plate making was completed was obtained through a water washing step and treatment with a gum (GU-7 (1: 1)).
[0175]
5). Evaluation of planographic printing plates
The lithographic printing plate obtained as described above was evaluated for the printing durability, cleaner printing durability, stain resistance, solid wall thickness, and the occurrence of pot-like residual film by the following methods.
(1) Printing durability
Printed using a PRINT-printer manufactured by Komori Corporation using DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. Printing durability was evaluated by the number of sheets.
The results are shown in Table 9. The printing durability was shown as a relative value with the printing durability of Example 6 as 100.
[0176]
(2) Cleaner printing durability
Printing was performed under the same conditions as in the evaluation of printing durability, and the solid image portion was washed with a plate cleaner solution (multi-cleaner, manufactured by Fuji Photo Film Co., Ltd.) every time 5000 sheets were printed, The solid image portion was evaluated based on the number of printed sheets until it was visually recognized that the solid image portion began to be faintly faded.
The results are shown in Table 9. The cleaner printing durability was shown as a relative value with the cleaner printing durability of Example 6 as 100.
[0177]
(3) Dirt resistance (soil stain)
Using a Mitsubishi diamond type F2 printing machine (manufactured by Mitsubishi Heavy Industries, Ltd.), printing was performed using Leo echo purple ink, and the blanket stain (ground stain) after printing 10,000 sheets was visually evaluated.
The results are shown in Table 9. The stain resistance was evaluated on a 12-point scale according to the degree of stain on the blanket. Larger numbers indicate better soil resistance. If the evaluation is 7 or more, it is at a practical level as a lithographic printing plate having excellent stain resistance.
[0178]
(4) Solidity of solid part
When printing with a DIC-GEOS (s) red ink on a Mitsubishi diamond type F2 printing machine (Mitsubishi Heavy Industries, Ltd.) The inking property of the part was evaluated. In addition, as the printing paper, coated recycled paper (OK coat, manufactured by Oji Paper Co., Ltd.) was used.
The results are shown in Table 9. The evaluation was made on a 12-point scale based on the number of solid ink imperfections. The larger the number, the better the solid part is. If the evaluation is 7 or more, it is at a practical level as a lithographic printing plate having excellent stain resistance.
[0179]
(5) Presence of pot-like residual film
The non-image area after development of the sample exposed with each plate surface energy amount was observed with an optical microscope at a magnification of 100 times, and the presence or absence of a pot-like residual film in an area of 1 mm square was examined. The pot-like residual film was evaluated based on the minimum value of the plate surface energy amount of the sample in which the pot-like residual film was not observed.
The results are shown in Table 9. From the smallest value of the plate surface energy amount to the largest value was represented as ◎, ○, ○ △, ×.
[0180]
As is apparent from Tables 8 and 9, the surface area ratio ΔS obtained from the three-dimensional data obtained by measuring 512 × 512 points on the surface of 50 μm □ using an atomic force microscope.⁵⁰And steepness a45^{50 (0.2-2)}Each of the lithographic printing plate precursors of the present invention using the lithographic printing plate support of the present invention (Examples 1 to 8) satisfying specific conditions, respectively, in terms of printing durability and stain resistance when used as a lithographic printing plate. It is excellent and it is difficult to cause poor inking of the solid part.
The surface area ratio ΔS obtained from three-dimensional data obtained by measuring 512 × 512 points on the surface of 5 μm □ using an atomic force microscope.^{5 (0.02-0.2)}And steepness a45^{5 (0.02-0.2)}The lithographic printing plate precursor of the present invention using the lithographic printing plate support of the present invention (Examples 1 to 8) satisfying specific conditions is excellent in cleaner printing durability.
Furthermore, the planographic printing plate of the present invention using the support for a planographic printing plate of the present invention (Examples 1 to 8) wherein the number of local deep portions having a depth of 4 μm or more present on the surface is 6 or less per 400 μm × 400 μm. The printing plate precursor is less likely to generate a pot-like residual film.
[0181]
[Table 8]

[0182]
[Table 9]

[0183]
【The invention's effect】
As explained above, the use of the lithographic printing plate support of the present invention characterized by the surface shape maintains a high level of balance between stain resistance and printing durability that could not be removed from the conventional trade-off relationship. In addition, it is possible to suppress the occurrence of poor ink deposition in the solid portion when the coated recycled paper is used.
[Brief description of the drawings]
FIG. 1 is a side view showing a concept of a brush graining process used in a mechanical surface roughening process in producing a lithographic printing plate support of the present invention.
FIG. 2 is a graph showing an example of an alternating waveform current waveform diagram used for electrochemical surface roughening treatment in producing a lithographic printing plate support of the present invention.
FIG. 3 is a side view showing an example of a radial type cell in an electrochemical surface roughening treatment using alternating current in producing a lithographic printing plate support of the present invention.
FIG. 4 is a schematic view of an anodizing apparatus used for anodizing treatment in the production of a lithographic printing plate support of the present invention.
[Explanation of symbols]
1 Aluminum plate
2, 4 Roller brush
3 Polishing slurry
5, 6, 7, 8 Support roller
11 Aluminum plate
12 Radial drum roller
13a, 13b Main pole
14 Electrolytic treatment liquid
15 Electrolyte supply port
16 slits
17 Electrolyte passage
18 Auxiliary anode
19a, 19b Thyristor
20 AC power supply
40 Main electrolytic cell
50 Auxiliary anode tank
410 Anodizing equipment
412 Feeding tank
414 Electrolytic treatment tank
416 Aluminum plate
418, 426 electrolyte
420 Feeding electrode
422, 428 Roller
424 Nip roller
430 Electrolytic electrode
432 tank wall
434 DC power supply

Claims (4)

From an actual area S _x ⁵⁰ determined by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points of a surface of 50 μm □ using an atomic force microscope, and a geometric measurement area S ₀ ⁵⁰ The surface area ratio ΔS ⁵⁰ obtained by the following formula (1) is 30 to 60%, and the inclination is 45 ° or more in the data obtained by extracting the component having a wavelength of 0.2 μm or more and 2 μm or less from the three-dimensional data. A lithographic printing plate support having a steepness a45 ^{50 (0.2-2)} of 5 to 40%, which is the area ratio of the portion.
ΔS ⁵⁰ = (S _x ⁵⁰ −S ₀ ⁵⁰ ) / S ₀ ⁵⁰ × 100 (%) (1) Using an atomic force microscope, a three-dimensional data obtained by measuring 512 × 512 points on the surface of 5 μm □ is extracted from data obtained by extracting components with wavelengths of 0.02 μm to 0.2 μm by an approximate three-point method. The surface area ratio ΔS ^{5 (0.02-0.2)} determined by the following equation (2) from the required real area S _x ^{5 (0.02-0.2)} and the geometric measurement area S ₀ ⁵ Is a steepness degree a45 ⁵ which is an area ratio of a portion having a slope of 45 ° or more in data obtained by extracting a component having a wavelength of 0.02 μm or more and 0.2 μm or less from the three-dimensional data. The lithographic printing plate support according to claim 1, wherein ^(0.02-0.2) is 10 to 40%.
ΔS ^{5 (0.02-0.2)} = (S _x ^{5 (0.02-0.2)} −S ₀ ⁵ ) / S ₀ ⁵ × 100 (%) (2) The lithographic printing plate support according to claim 1 or 2, wherein the number of local deep portions having a depth of 4 µm or more present on the surface is 6 or less per 400 µm x 400 µm. A lithographic printing plate precursor comprising an image recording layer provided on the lithographic printing plate support according to any one of claims 1 to 3.

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