JP3787334B2 - Planographic printing plate precursor - Google Patents

Description

【０１０９】
【化２】

【０１１０】
【化３】

【０１１１】
【化４】

【０１１２】
【化５】

【０１１３】
下塗層の形成に用いられる上記高分子化合物は、一般にはラジカル連鎖重合法を用いて製造することができる（“Ｔｅｘｔｂｏｏｋ ｏｆ Ｐｏｌｙｍｅｒ Ｓｃｉｅｎｃｅ”３ｒｄ ｅｄ．（１９８４）Ｆ．Ｗ．Ｂｉｌｌｍｅｙｅｒ，ＡＷｉｌｅｙ−Ｉｎｔｅｒｓｃｉｅｎｃｅ Ｐｕｂｌｉｃａｔｉｏｎ参照）。
【０１１４】
上記高分子化合物の分子量は広範囲であってもよいが、光散乱法を用いて測定したとき、重量平均分子量（Ｍ_w ）が５００〜２，０００，０００であるのが好ましく、１，０００〜６００，０００の範囲であるのがより好ましい。また、この高分子化合物中に含まれる未反応モノマー量は広範囲であってもよいが、２０質量％以下であるのが好ましく、１０質量％以下であるのがより好ましい。
【０１１５】
（下塗層形成用高分子化合物の製法等）
つぎに、酸基を有する構成成分とともにオニウム基を有する構成成分をも有する高分子化合物の合成例を、上記で挙げたｐ−ビニル安息香酸とビニルベンジルトリメチルアンモニウムクロリドとの共重合体（上記Ｎｏ．１）を例にとって示すが、他の高分子化合物も同様の方法で合成することができる。
【０１１６】
ｐ−ビニル安息香酸（北興化学工業社製）１４６．９ｇ（０．９９ｍｏｌ）、ビニルベンジルトリメチルアンモニウムクロリド４４．２ｇ（０．２１ｍｏｌ）および２−メトキシエタノール４４６ｇを１Ｌ容の三つ口フラスコに取り、窒素気流下かくはんしながら、加熱し７５℃に保った。この溶液に２，２−アゾビス（イソ酪酸）ジメチル２．７６ｇ（１２ｍｍｏｌ）を加え、かくはんを続けた。２時間後、更に、２，２−アゾビス（イソ酪酸）ジメチル２．７６ｇ（１２ｍｍｏｌ）を加え、かくはんを続けた。２時間かくはんした後、室温まで放冷した。この反応液をかくはん下、１２Ｌの酢酸エチル中に注いだ。析出した固体をろ取し、乾燥させた。その収量は１８９．５ｇであった。得られた固体について光散乱法で分子量測定を行った結果、重量平均分子量（Ｍ_w ）は３．２万であった。
【０１１７】
（下塗層の形成）
下塗層は、上記高分子化合物を、上述した平版印刷版用支持体の上に種々の方法で塗布することにより設けることができる。
下塗層を設ける方法としては、例えば、メタノール、エタノール、メチルエチルケトン等の有機溶剤もしくはそれらの混合溶剤またはこれらの有機溶剤と水との混合溶剤に上記高分子化合物を溶解させた溶液を平版印刷版用支持体上に塗布し乾燥させて設ける方法、メタノール、エタノール、メチルエチルケトン等の有機溶剤もしくはそれらの混合溶剤またはこれらの有機溶剤と水との混合溶剤に上記高分子化合物を溶解させた溶液に、平版印刷版用支持体を浸せきさせて高分子化合物を吸着させた後、水等によって洗浄し乾燥させて設ける方法が挙げられる。
【０１１８】
前者の方法では、上記高分子化合物の０．００５〜１０質量％の濃度の溶液を種々の方法で塗布できる。例えば、バーコーター塗布、回転塗布、スプレー塗布、カーテン塗布等のいずれの方法を用いてもよい。また、後者の方法では、溶液の濃度は０．０１〜２０質量％、好ましくは０．０５％〜５質量％であり、浸せき温度は２０℃〜９０℃、好ましくは２５〜５０℃であり、浸せき時間は０．１秒〜２０分、好ましくは２秒〜１分である。
【０１１９】
上記の溶液は、アンモニア、トリエチルアミン、水酸化カリウム等の塩基性物質；塩酸、リン酸、硫酸、硝酸等の無機酸、ニトロベンゼンスルホン酸、ナフタレンスルホン酸等の有機スルホン酸、フェニルホスホン酸等の有機ホスホン酸、安息香酸、クマル酸、リンゴ酸等の有機カルボン酸等の種々の有機酸性物質；ナフタレンスルホニルクロライド、ベンゼンスルホニルクロライド等の有機酸クロライド等によりｐＨを調整し、ｐＨ０〜１２、より好ましくはｐＨ０〜５の範囲で使用することもできる。
下塗層を形成する高分子化合物の乾燥後の被覆量は、２〜１００ｍｇ／ｍ² が適当であり、好ましくは５〜５０ｍｇ／ｍ² である。上記被覆量が２ｍｇ／ｍ² よりも少ないと十分な効果が得られない場合がある。また、１００ｍｇ／ｍ² よりも多い場合も同様である。
【０１２０】
＜画像記録層＞
熱により画像形成することができる画像記録層としては、例えば、サーマルポジタイプ、サーマルネガタイプ、無処理タイプが好適に挙げられる。以下、好適に用いられるサーマルポジタイプの画像記録層について説明する。
【０１２１】
サーマルポジタイプの画像記録層は、（Ａ）水不溶性かつアルカリ可溶性の樹脂（以下「アルカリ可溶性樹脂」という。）と、（Ｂ）赤外線吸収剤とを含有する。
【０１２２】
（Ａ）アルカリ可溶性樹脂
サーマルポジタイプの画像記録層に使用できる（Ａ）アルカリ可溶性樹脂は、高分子中の主鎖および／または側鎖に酸性基を含有する単独重合体、共重合体またはこれらの混合物を包含する。酸性基に関しては、あらかじめ酸性基を有しているモノマーを重合して導入する方法と、重合後の高分子反応によって導入する方法、およびそれらを併用する方法のいずれの方法で導入してもよい。
【０１２３】
アルカリ可溶性樹脂としては、特に限定されず、例えば、プラスチック・エージ（株）「フェノール樹脂」、アイピーシー（株）「フェノール樹脂の合成・硬化・強靱化および応用」、日刊工業新聞社「プラスチック材料講座１５ フェノール樹脂」、工業調査会（株）「プラスチック全書１５ フェノール樹脂」等の成書に記載されているフェノール樹脂、ポリヒドロキシスチレン、ポリハロゲン化ヒドロキシスチレン、Ｎ−（４−ヒドロキシフェニル）メタクリルアミドの共重合体、ハイドロキノンモノメタクリレート共重合体；特開平７−２８２４４号公報に記載されているスルホニルイミド系ポリマー；特開平７−３６１８４号公報に記載されているカルボキシ基含有ポリマー；特開昭５１−３４７１１号公報に記載されているようなフェノール性ヒドロキシ基を含有するアクリル系樹脂；特開平２−８６６号公報に記載されているスルホンアミド基を有するアクリル系樹脂、ウレタン系樹脂等の種々のアルカリ可溶性の高分子化合物を用いることができる。
中でも、下記（１）〜（６）の酸性基を高分子の主鎖および／または側鎖中に有するものが、アルカリ性現像液に対する溶解性および溶解抑制能発現の点で好ましい。
【０１２４】
（１）フェノール性ヒドロキシ基（−Ａｒ−ＯＨ）
（２）スルホンアミド基（−ＳＯ₂ ＮＨ−Ｒ）
（３）置換スルホンアミド系酸基（−ＳＯ₂ ＮＨＣＯＲ、−ＳＯ₂ ＮＨＳＯ₂ Ｒ、−ＣＯＮＨＳＯ₂ Ｒ）（以下「活性イミド基」という。）
（４）カルボキシ基（−ＣＯ₂ Ｈ）
（５）スルホ基（−ＳＯ₃ Ｈ）
（６）リン酸基（−ＯＰＯ₃ Ｈ₂ ）
【０１２５】
上記（１）〜（６）中、Ａｒは置換基を有していてもよい２価のアリール連結基を表し、Ｒは、置換基を有していてもよい炭化水素基を表す。
【０１２６】
上記（１）〜（６）より選ばれる酸性基を有するアルカリ可溶性樹脂の中でも、（１）フェノール性ヒドロキシ基、（２）スルホンアミド基、（３）活性イミド基、および（４）カルボン酸基のうち少なくとも一つを有するアルカリ可溶性樹脂が好ましく、特に、（１）フェノール性ヒドロキシ基、（２）スルホンアミド基および（４）カルボン酸基のうち少なくとも一つを有するアルカリ可溶性樹脂が、アルカリ性現像液に対する溶解性、現像ラチチュードおよび画像記録層の膜強度の点からより好ましい。
【０１２７】
上記（１）〜（６）の酸性基を有するアルカリ可溶性樹脂としては、例えば、以下のものが挙げられる。
（１）フェノール性ヒドロキシ基を有するアルカリ可溶性樹脂としては、例えば、ノボラック樹脂、レゾール樹脂、ポリビニルフェノール樹脂、フェノール性ヒドロキシ基を有するアクリル樹脂等が挙げられる。これらの中でも画像形成性や熱硬化性の観点からノボラック樹脂、レゾール樹脂、ポリビニルフェノール樹脂が好ましく、安定性の点からノボラック樹脂、ポリビニルフェノール樹脂がより好ましく、原料入手性、汎用性の観点からノボラック樹脂が特に好ましい。
【０１２８】
ノボラック樹脂とは、例えば、フェノール、ｏ−クレゾール、ｍ−クレゾール、ｐ−クレゾール、２，５−キシレノール、３，５−キシレノール、ｏ−エチルフェノール、ｍ−エチルフェノール、ｐ−エチルフェノール、プロピルフェノール、ｎ−ブチルフェノール、ｔｅｒｔ−ブチルフェノール、１−ナフトール、２−ナフトール、ピロカテコール、レゾルシノール、ハイドロキノン、ピロガロール、１，２，４−ベンゼントリオール、フロログルシノール、４，４′−ビフェニルジオール、２，２−ビス（４′−ヒドロキシフェニル）プロパン等のフェノール類の少なくとも１種を、酸性触媒下、例えば、ホルムアルデヒド、アセトアルデヒド、プロピオンアルデヒド、ベンズアルデヒド、フルフラール等のアルデヒド類（ホルムアルデヒドに代えてパラホルムアルデヒドを、アセトアルデヒドに代えてパラアルデヒドを用いてもよい。）、または、アセトン、メチルエチルケトン、メチルイソブチルケトン等のケトン類の少なくとも１種と重縮合させた樹脂のことを指す。
【０１２９】
本発明においては、フェノール類として、フェノール、ｏ−クレゾール、ｍ−クレゾール、ｐ−クレゾール、２，５−キシレノール、３，５−キシレノールおよびレゾルシノールのうち少なくとも１種を用い、アルデヒド類またはケトン類として、ホルムアルデヒド、アセトアルデヒドおよびプロピオンアルデヒドのうち少なくとも１種を用いた重縮合体が好ましい。特に、ｍ−クレゾール：ｐ−クレゾール：２，５−キシレノール：３，５−キシレノール：レゾルシノールの混合割合がモル比で４０〜１００：０〜５０：０〜２０：０〜２０：０〜２０である混合フェノール類、または、フェノール：ｍ−クレゾール：ｐ−クレゾールの混合割合がモル比で０〜１００：０〜７０：０〜６０である（混合）フェノール類と、ホルムアルデヒドとの重縮合体が好ましい。
【０１３０】
なお、本発明に好適に用いられるサーマルポジタイプの画像記録層には溶剤抑止剤を含有させることが好ましい。その場合は、ｍ−クレゾール：ｐ−クレゾール：２，５−キシレノール：３，５−キシレノール：レゾルシノールの混合割合がモル比で７０〜１００：０〜３０：０〜２０：０〜２０：０〜２０である混合フェノール類、または、フェノール：ｍ−クレゾール：ｐ−クレゾールの混合割合がモル比で１０〜１００：０〜６０：０〜４０である（混合）フェノール類と、ホルムアルデヒドとの重縮合体が好ましい。
【０１３１】
また、フェノール性ヒドロキシ基を有するアルカリ可溶性樹脂として、フェノール性ヒドロキシ基を有する重合性モノマーの重合体を挙げることができる。
フェノール性ヒドロキシ基を有する重合性モノマーとしては、フェノール性ヒドロキシ基を有するアクリルアミド、メタクリルアミド、アクリル酸エステル、メタクリル酸エステルまたはヒドロキシスチレン等が挙げられる。
具体的には、Ｎ−（２−ヒドロキシフェニル）アクリルアミド、Ｎ−（３−ヒドロキシフェニル）アクリルアミド、Ｎ−（４−ヒドロキシフェニル）アクリルアミド、Ｎ−（２−ヒドロキシフェニル）メタクリルアミド、Ｎ−（３−ヒドロキシフェニル）メタクリルアミド、Ｎ−（４−ヒドロキシフェニル）メタクリルアミド、ｏ−ヒドロキシフェニルアクリレート、ｍ−ヒドロキシフェニルアクリレート、ｐ−ヒドロキシフェニルアクリレート、ｏ−ヒドロキシフェニルメタクリレート、ｍ−ヒドロキシフェニルメタクリレート、ｐ−ヒドロキシフェニルメタクリレート、ｏ−ヒドロキシスチレン、ｍ−ヒドロキシスチレン、ｐ−ヒドロキシスチレン、２−（２−ヒドロキシフェニル）エチルアクリレート、２−（３−ヒドロキシフェニル）エチルアクリレート、２−（４−ヒドロキシフェニル）エチルアクリレート、２−（２−ヒドロキシフェニル）エチルメタクリレート、２−（３−ヒドロキシフェニル）エチルメタクリレート、２−（４−ヒドロキシフェニル）エチルメタクリレート等を好適に使用することができる。
【０１３２】
また、酸基前駆体を重合し、高分子化した後で酸基へと誘導してもよい。例えば、酸基前駆体としてｐ−アセトキシスチレンを重合した後、エステル部を加水分解しフェノール性ヒドロキシ基へと誘導してもよい。
また、米国特許第４，１２３，２７９号明細書に記載されているような、ｔ−ブチルフェノールホルムアルデヒド樹脂、オクチルフェノールホルムアルデヒド樹脂等の、炭素数３〜８のアルキル基を置換基として有するフェノールとホルムアルデヒドとの縮重合体も好適に例示することができる。
【０１３３】
（２）スルホンアミド基を有するアルカリ可溶性樹脂としては、例えば、スルホンアミド基を有する化合物に由来する最小構成単位を主要構成成分として構成される重合体を挙げることができる。上記のような化合物としては、窒素原子に少なくとも一つの水素原子が結合したスルホンアミド基と、重合可能な不飽和基とを分子内にそれぞれ一つ以上有する化合物が挙げられる。中でも、アクリロイル基、アリル基またはビニロキシ基と、モノ置換アミノスルホニル基または置換スルホニルイミノ基とを分子内に有する低分子化合物が好ましい。例えば、下記一般式（Ｉ）〜（Ｖ）で表される化合物が挙げられる。
【０１３４】
【化６】

【０１３５】
式中、Ｘ¹ およびＸ² は、それぞれ−Ｏ−または−ＮＲ⁷ −を示す。Ｒ¹ およびＲ⁴ は、それぞれ水素原子または−ＣＨ₃ を表す。Ｒ² 、Ｒ⁵ 、Ｒ⁹ 、Ｒ¹²およびＲ¹⁶は、それぞれ置換基を有していてもよい炭素数１〜１２のアルキレン基、シクロアルキレン基、アリーレン基またはアラルキレン基を表す。Ｒ³ 、Ｒ⁷ およびＲ¹³は、水素原子またはそれぞれ置換基を有していてもよい炭素数１〜１２のアルキル基、シクロアルキル基、アリール基またはアラルキル基を表す。また、Ｒ⁶ およびＲ¹⁷は、それぞれ置換基を有していてもよい炭素数１〜１２のアルキル基、シクロアルキル基、アリール基またはアラルキル基を示す。Ｒ⁸ 、Ｒ¹⁰およびＲ¹⁴は、水素原子または−ＣＨ₃ を表す。Ｒ¹¹およびＲ¹⁵は、それぞれ単結合、または置換基を有していてもよい炭素数１〜１２のアルキレン基、シクロアルキレン基、アリーレン基もしくはアラルキレン基を表す。Ｙ¹ およびＹ² は、それぞれ単結合または−ＣＯ−を表す。具体的には、ｍ−アミノスルホニルフェニルメタクリレート、Ｎ−（ｐ−アミノスルホニルフェニル）メタクリルアミド、Ｎ−（ｐ−アミノスルホニルフェニル）アクリルアミド等を好適に使用することができる。
【０１３６】
（３）活性イミド基を有するアルカリ可溶性樹脂としては、例えば、活性イミド基を有する化合物に由来する最小構成単位を主要構成成分として構成される重合体を挙げることができる。上記のような化合物としては、下記構造式で表される活性イミド基と、重合可能な不飽和基とを分子内にそれぞれ一つ以上有する化合物を挙げることができる。
【０１３７】
【化７】

【０１３８】
このような化合物としては、具体的には、Ｎ−（ｐ−トルエンスルホニル）メタクリルアミド、Ｎ−（ｐ−トルエンスルホニル）アクリルアミド等を好適に使用することができる。
【０１３９】
（４）カルボン酸基を有するアルカリ可溶性樹脂としては、例えば、カルボン酸基と、重合可能な不飽和基とを分子内にそれぞれ一つ以上有する化合物に由来する最小構成単位を主要構成成分とする重合体を挙げることができる。
（５）スルホ基を有するアルカリ可溶性樹脂としては、例えば、スルホ基と、重合可能な不飽和基とを分子内にそれぞれ一つ以上有する化合物に由来する最小構成単位を主要構成単位とする重合体を挙げることができる。
（６）リン酸基を有するアルカリ可溶性樹脂としては、例えば、リン酸基と、重合可能な不飽和基とを分子内にそれぞれ一つ以上有する化合物に由来する最小構成単位を主要構成成分とする重合体を挙げることができる。
【０１４０】
上記（１）〜（６）から選ばれる酸性基を有する最小構成単位は、特に１種のみである必要はなく、同一の酸性基を有する最小構成単位を２種以上、または異なる酸性基を有する最小構成単位を２種以上共重合させたものを用いることもできる。
【０１４１】
前記共重合体は、共重合させる上記（１）〜（６）より選ばれる酸性基を有する化合物が共重合体中に１０モル％以上含まれているものが好ましく、２０モル％以上含まれているものがより好ましい。１０モル％未満であると、アルカリ可溶性が不十分となりやすく、現像ラチチュードの向上効果が十分達成されないことがある。
【０１４２】
化合物を共重合してアルカリ可溶性樹脂を共重合体として用いる場合、共重合させる化合物として、前記（１）〜（６）の酸性基を含まない他の化合物を用いることもできる。（１）〜（６）の酸性基を含まない他の化合物の例としては、下記（ｍ１）〜（ｍ１３）に挙げる化合物を例示することができるが、これらに限定されるものではない。
【０１４３】
（ｍ１）２−ヒドロキシエチルアクリレート、２−ヒドロキシエチルメタクリレート等の脂肪族ヒドロキシ基を有するアクリル酸エステル類およびメタクリル酸エステル類、
（ｍ２）アクリル酸メチル、アクリル酸エチル、アクリル酸プロピル、アクリル酸ブチル、アクリル酸アミル、アクリル酸ヘキシル、アクリル酸オクチル、アクリル酸ベンジル、アクリル酸−２−クロロエチル、グリシジルアクリレート等のアルキルアクリレート、
（ｍ３）メタクリル酸メチル、メタクリル酸エチル、メタクリル酸プロピル、メタクリル酸ブチル、メタクリル酸アミル、メタクリル酸ヘキシル、メタクリル酸シクロヘキシル、メタクリル酸ベンジル、メタクリル酸−２−クロロエチル、グリシジルメタクリレート等のアルキルメタクリレート、
【０１４４】
（ｍ４）アクリルアミド、メタクリルアミド、Ｎ−メチロールアクリルアミド、Ｎ−エチルアクリルアミド、Ｎ−ヘキシルメタクリルアミド、Ｎ−シクロヘキシルアクリルアミド、Ｎ−ヒドロキシエチルアクリルアミド、Ｎ−フェニルアクリルアミド、Ｎ−ニトロフェニルアクリルアミド、Ｎ−エチル−Ｎ−フェニルアクリルアミド等のアクリルアミドまたはメタクリルアミド、
（ｍ５）エチルビニルエーテル、２−クロロエチルビニルエーテル、ヒドロキシエチルビニルエーテル、プロピルビニルエーテル、ブチルビニルエーテル、オクチルビニルエーテル、フェニルビニルエーテル等のビニルエーテル類、
（ｍ６）ビニルアセテート、ビニルクロロアセテート、ビニルブチレート、安息香酸ビニル等のビニルエステル類、
【０１４５】
（ｍ７）スチレン、α−メチルスチレン、メチルスチレン、クロロメチルスチレン、ｐ−アセトキシスチレン等のスチレン類、
（ｍ８）メチルビニルケトン、エチルビニルケトン、プロピルビニルケトン、フェニルビニルケトン等のビニルケトン類、
（ｍ９）エチレン、プロピレン、イソブチレン、ブタジエン、イソプレン等のオレフィン類、
【０１４６】
（ｍ１０）Ｎ−ビニルピロリドン、アクリロニトリル、メタクリロニトリル等、
（ｍ１１）マレイミド、Ｎ−アクリロイルアクリルアミド、Ｎ−アセチルメタクリルアミド、Ｎ−プロピオニルメタクリルアミド、Ｎ−（ｐ−クロロベンゾイル）メタクリルアミド等の不飽和イミド、
（ｍ１２）無水マレイン酸、イタコン酸無水物、アクリル酸クロリド、メタクリル酸クロリド等、
（ｍ１３）α位にヘテロ原子が結合したメタクリル酸系モノマー（例えば、特願２００１−１１５５９５号明細書、特願２００１−１１５５９８号明細書等に記載されている化合物）。
【０１４７】
本発明においてアルカリ可溶性樹脂が、前記（１）フェノール性ヒドロキシ基を有する重合性モノマー、（２）スルホンアミド基を有する重合性モノマー、（３）活性イミド基を有する重合性モノマー、（４）カルボン酸基を有する重合性モノマー、（５）スルホ基を有する重合性モノマー、および（６）リン酸基を有する重合性モノマーの単独重合体または共重合体の場合、ゲルパーミエーションクロマトグラフィー測定によるポリスチレン換算の重量平均分子量（以下、単に「重量平均分子量」という。）が２，０００以上、数平均分子量が５００以上のものが好ましく、更に好ましくは、重量平均分子量が５，０００〜３００，０００で、数平均分子量が８００〜２５０，０００であり、分散度（重量平均分子量／数平均分子量）が１．１〜１０のものである。
また、本発明においてアルカリ可溶性樹脂がノボラック樹脂である場合には、重量平均分子量が５００〜１００，０００であり、数平均分子量が２００〜５０，０００のものが好ましい。特願２００１−１２６２７８号明細書に記載されているような低分子成分、特に残存モノマー成分の比率が少ないノボラック樹脂を用いてもよい。
【０１４８】
これらアルカリ可溶性樹脂は、それぞれ１種でまたは２種以上を組み合わせて用いることができ、画像記録層全固形分中、３０〜９９質量％、好ましくは４０〜９５質量％、特に好ましくは５０〜９０質量％の添加量で用いられる。
アルカリ可溶性樹脂の添加総量が３０質量％未満であると画像記録層の耐久性が悪化する場合があり、また、９９質量％を超えると感度および画像形成性の観点で好ましくない場合がある。
【０１４９】
アルカリ可溶性樹脂を併用する場合、どのような組み合わせを用いてもよいが、特に好適な例としては、フェノール性ヒドロキシ基を有するポリマーとスルホンアミド酸基を有するポリマーとの併用、フェノール性ヒドロキシ基を有するポリマーとカルボン酸基を有するポリマーとの併用、フェノール性ヒドロキシ基を有するポリマー２種以上の併用、例えば、米国特許第４，１２３，２７９号明細書に記載されているような、ｔ−ブチルフェノールとホルムアルデヒドとの縮重合体や、オクチルフェノールとホルムアルデヒドとの縮重合体のような、炭素数３〜８のアルキル基を置換基として有するフェノールとホルムアルデヒドとの縮重合体、特開２０００−２４１９７２号公報に記載されている芳香環上に電子吸引性基を有するフェノール構造を有するアルカリ可溶性樹脂等との併用を挙げることができる。
【０１５０】
（Ｂ）赤外線吸収剤
本発明に用いられる赤外線吸収剤は、光エネルギー照射線を吸収し、熱を発生する物質であれば、吸収波長域を限定されないが、入手容易な高出力レーザーへの適合性の観点から、波長７００〜１２００ｎｍに吸収極大を有する赤外線吸収性染料または顔料が好ましく挙げられる。
【０１５１】
染料としては、市販の染料および「染料便覧」（有機合成化学協会編集、昭和４５年刊）等の文献に記載されている公知のものが利用できる。具体的には、アゾ染料、金属錯塩アゾ染料、ピラゾロンアゾ染料、ナフトキノン染料、アントラキノン染料、フタロシアニン染料、ナフタロシアニン染料、カルボニウム染料、キノンイミン染料、メチン染料、シアニン染料、スクアリリウム色素、（チオ）ピリリウム塩、金属チオレート錯体、インドアニリン金属錯体系染料、オキソノール染料、ジイモニウム染料、アミニウム染料、クロコニウム染料、分子間ＣＴ色素等の染料が挙げられる。
【０１５２】
好ましい染料としては、例えば、特開昭５８−１２５２４６号、特開昭５９−８４３５６号、特開昭５９−２０２８２９号、特開昭６０−７８７８７号等の各公報に記載されているシアニン染料、特開昭５８−１７３６９６号、特開昭５８−１８１６９０号、特開昭５８−１９４５９５号等の各公報に記載されているメチン染料、特開昭５８−１１２７９３号、特開昭５８−２２４７９３号、特開昭５９−４８１８７号、特開昭５９−７３９９６号、特開昭６０−５２９４０号、特開昭６０−６３７４４号等の各公報に記載されているナフトキノン染料、特開昭５８−１１２７９２号公報等に記載されているスクアリリウム色素、英国特許第４３４，８７５号明細書に記載されているシアニン染料等を挙げることができる。
【０１５３】
また、米国特許第５，１５６，９３８号明細書に記載されている近赤外吸収増感剤も好適に用いられ、また、米国特許第３，８８１，９２４号明細書に記載されている置換されたアリールベンゾ（チオ）ピリリウム塩、特開昭５７−１４２６４５号公報（米国特許第４，３２７，１６９号明細書）に記載されているトリメチンチアピリリウム塩、特開昭５８−１８１０５１号、同５８−２２０１４３号、同５９−４１３６３号、同５９−８４２４８号、同５９−８４２４９号、同５９−１４６０６３号、同５９−１４６０６１号の各公報に記載されているピリリウム系化合物、特開昭５９−２１６１４６号公報に記載されているシアニン色素、米国特許第４，２８３，４７５号明細書に記載されているペンタメチンチオピリリウム塩、特公平５−１３５１４号公報および同５−１９７０２号公報に記載されているピリリウム化合物も好ましく用いられる。
【０１５４】
また、染料として好ましい別の例として米国特許第４，７５６，９９３号明細書中に式（Ｉ）および（ＩＩ）として記載されている近赤外吸収染料を挙げることができる。
【０１５５】
これらの染料のうち特に好ましいものとしては、シアニン色素、フタロシアニン染料、オキソノール染料、スクアリリウム色素、ピリリウム塩、チオピリリウム染料、ニッケルチオレート錯体が挙げられる。更に、下記一般式（ａ）で示される染料が光熱変換効率に優れるため好ましい。また、下記一般式（ａ）で示されるシアニン色素は、本発明に好適に用いられる画像記録層用組成物に使用した場合に、アルカリ溶解性樹脂との高い相互作用を与え、かつ、安定性、経済性に優れるため好ましい。
【０１５６】
【化８】

【０１５７】
一般式（ａ）中、Ｒ¹ およびＲ² は、それぞれ独立に、炭素原子数１〜１２のアルキル基を表し、アルキル基上にはアルコキシ基、アリール基、アミド基、アルコキシカルボニル基、ヒドロキシ基、スルホ基およびカルボキシ基からなる群から選択される置換基を有してもよい。Ｙ¹ およびＹ² は、それぞれ独立に、酸素、硫黄、セレン、ジアルキルメチレン基または−ＣＨ＝ＣＨ−を表す。Ａｒ¹ およびＡｒ² は、それぞれ独立に、芳香族炭化水素基を表し、アルキル基、アルコキシ基、ハロゲン原子およびアルコキシカルボニル基からなる群から選択される置換基を有してもよく、Ｙ¹ およびＹ² と隣接した連続２炭素原子で芳香環を縮環してもよい。
【０１５８】
Ｘは電荷の中和に必要なカウンターイオンを表し、色素カチオン部がアニオン性の置換基を有する場合は必ずしも必要ではない。
Ｑはトリメチン基、ペンタメチン基、ヘプタメチン基、ノナメチン基およびウンデカメチン基からなる群から選択されるポリメチン基を表す。露光に用いる赤外線に対する波長適性と安定性の点からペンタメチン基、ヘプタメチン基またはノナメチン基が好ましく、いずれかの炭素上に連続した三つのメチン鎖を含むシクロヘキセン環またはシクロペンテン環を有することが安定性の点で好ましい。
【０１５９】
Ｑはアルコキシ基、アリールオキシ基、アルキルチオ基、アリールチオ基、ジアルキルアミノ基、ジアリールアミノ基、ハロゲン原子、アルキル基、アラルキル基、シクロアルキル基、アリール基、オキシ基、イミニウム塩基および下記一般式（２）で表される置換基からなる群から選択される基で置換されていてもよい。好ましい置換基としては、塩素原子等のハロゲン原子、ジフェニルアミノ基等のジアリールアミノ基、フェニルチオ基等のアリールチオ基が挙げられる。
【０１６０】
【化９】

【０１６１】
式中、Ｒ³ およびＲ⁴ は、それぞれ独立に、水素原子、炭素数１〜８のアルキル基または炭素数６〜１０のアリール基を表し、Ｙ³ は酸素原子または硫黄原子を表す。
【０１６２】
一般式（ａ）で示されるシアニン色素のうち、波長８００〜８４０ｎｍの赤外線で露光する場合は、特に好ましいものとしては下記一般式（ａ−１）で示されるヘプタメチンシアニン色素を挙げることができる。
【０１６３】
【化１０】

【０１６４】
一般式（ａ−１）中、Ｘ¹ は、水素原子またはハロゲン原子を表す。Ｒ¹ およびＲ² は、それぞれ独立に、炭素原子数１〜１２の炭化水素基を示す。記録層塗布液の保存安定性から、Ｒ¹ およびＲ² は、炭素原子数２個以上の炭化水素基であることが好ましく、更に、Ｒ¹ とＲ² とは互いに結合し、５員環または６員環を形成していることが特に好ましい。
【０１６５】
Ａｒ¹ およびＡｒ² は、それぞれ独立に、置換基を有していてもよい芳香族炭化水素基を示す。好ましい芳香族炭化水素基としては、ベンゼン環およびナフタレン環が挙げられる。また、好ましい置換基としては、炭素原子数１２個以下の炭化水素基、ハロゲン原子、炭素原子数１２個以下のアルコキシ基が挙げられる。Ｙ¹ およびＹ² は、それぞれ独立に、硫黄原子または炭素原子数１２個以下のジアルキルメチレン基を示す。Ｒ³ およびＲ⁴ は、それぞれ独立に、置換基を有していてもよい炭素原子数２０個以下の炭化水素基を示す。好ましい置換基としては、炭素原子数１２個以下のアルコキシ基、カルボキシ基、スルホ基が挙げられる。Ｒ⁵ 、Ｒ⁶ 、Ｒ⁷ およびＲ⁸ は、それぞれ独立に、水素原子または炭素原子数１２個以下の炭化水素基を示す。原料の入手性から、好ましくは水素原子である。また、Ｚ_a ^- は、電荷の中和に必要な対アニオンを示し、Ｒ¹ 〜Ｒ⁸ のいずれかがアニオン性置換基で置換されている場合は、Ｚ_a ^- は必要ない。好ましいＺ_a ^- は、記録層塗布液の保存安定性から、ハロゲンイオン、過塩素酸イオン、テトラフルオロボレートイオン、ヘキサフルオロホスフェートイオンおよびスルホン酸イオンであり、特に好ましくは、過塩素酸イオン、テトラフルオロボレートイオン、ヘキサフルオロフォスフェートイオンおよびスルホン酸イオンである。上記一般式（ａ−１）で示されるヘプタメチン色素は、サーマルポジタイプの画像記録層に好適に用いることができ、特にフェノール性ヒドロキシ基を有するアルカリ可溶性樹脂と組み合わせたいわゆる相互作用解除型のサーマルポジタイプの画像記録層に好ましく用いられる。
【０１６６】
本発明において、好適に用いることのできる一般式（ａ）で示されるシアニン色素の具体例としては、以下に例示するもののほか、特開２００１−１３３９６９号公報の段落番号［００１７］〜［００１９］、特開２００２−４０６３８号公報の段落番号［００１２］〜［００３８］、特開２００２−２３３６０号公報の段落番号［００１２］〜［００２３］に記載されたものを挙げることができる。
【０１６７】
【化１１】

【０１６８】
【化１２】

【０１６９】
【化１３】

【０１７０】
上記以外の赤外線吸収剤としては、特開２００１−２４２６１３号公報に記載されている複数の発色団を有する染料、特開２００２−９７３８４号公報、米国特許第６，１２４，４２５号明細書に記載されている高分子化合物に共有結合で発色団が連結された色素、米国特許６，２４８，８９３号明細書に記載されているアニオン染料、特開２００１−３４７７６５号公報に記載されている表面配向性基を有する染料等を好適に用いることができる。
【０１７１】
本発明において赤外線吸収剤として使用される顔料としては、市販の顔料およびカラーインデックス（Ｃ．Ｉ．）便覧、「最新顔料便覧」（日本顔料技術協会編、１９７７年刊）、「最新顔料応用技術」（ＣＭＣ出版、１９８６年刊）、「印刷インキ技術」ＣＭＣ出版、１９８４年刊）に記載されている顔料が挙げられる。
【０１７２】
顔料の種類としては、黒色顔料、黄色顔料、オレンジ色顔料、褐色顔料、赤色顔料、紫色顔料、青色顔料、緑色顔料、蛍光顔料、金属粉顔料、その他、ポリマー結合色素が挙げられる。具体的には、不溶性アゾ顔料、アゾレーキ顔料、縮合アゾ顔料、キレートアゾ顔料、フタロシアニン系顔料、アントラキノン系顔料、ペリレンおよびペリノン系顔料、チオインジゴ系顔料、キナクリドン系顔料、ジオキサジン系顔料、イソインドリノン系顔料、キノフタロン系顔料、染付けレーキ顔料、アジン顔料、ニトロソ顔料、ニトロ顔料、天然顔料、蛍光顔料、無機顔料、カーボンブラック等が使用できる。これらの顔料のうち好ましいものはカーボンブラックである。
【０１７３】
これら顔料は表面処理をせずに用いてもよく、表面処理を施して用いてもよい。表面処理の方法には、樹脂やワックスを表面コートする方法、界面活性剤を付着させる方法、反応性物質（例えば、シランカップリング剤、エポキシ化合物、ポリイソシアネート等）を顔料表面に結合させる方法等が考えられる。上記の表面処理方法は、「金属石鹸の性質と応用」（幸書房）、「印刷インキ技術」（ＣＭＣ出版、１９８４年刊）および「最新顔料応用技術」（ＣＭＣ出版、１９８６年刊）に記載されている。
【０１７４】
顔料の粒径は０．０１〜１０μｍの範囲にあることが好ましく、０．０５〜１μｍの範囲にあることが更に好ましく、特に０．１〜１μｍの範囲にあることが好ましい。顔料の粒径が０．０１μｍ未満のときは分散物の画像記録層塗布液中での安定性の点で好ましくない場合があり、また、１０μｍを超えると画像記録層の均一性の点で好ましくない場合がある。
【０１７５】
顔料を分散する方法としては、インク製造やトナー製造等に用いられる公知の分散技術が使用できる。分散機としては、超音波分散器、サンドミル、アトライター、パールミル、スーパーミル、ボールミル、インペラー、デスパーザー、ＫＤミル、コロイドミル、ダイナトロン、３本ロールミル、加圧ニーダー等が挙げられる。詳細は、「最新顔料応用技術」（ＣＭＣ出版、１９８６年刊）に記載されている。
【０１７６】
これらの顔料または染料は、記録層を構成する全固形分に対し０．０１〜５０質量％、好ましくは０．１〜１０質量％、染料の場合特に好ましくは０．５〜１０質量％、顔料の場合特に好ましくは０．１〜１０質量％の割合で添加することができる。顔料または染料の添加量が０．０１質量％未満であると感度が低くなる傾向があり、また５０質量％を超えて配合すると、配合量の増加にしたがって記録層の均一性や、記録層の耐久性に好ましくない影響を与えるおそれがでてくる。また、用いられる染料または顔料は単一の化合物であっても、２種以上の化合物を混合したものでもよく、複数の波長の露光機へ対応するために、吸収波長の異なる染料または顔料を併用することも好ましく行われる。
【０１７７】
（Ｃ）その他の成分
画像記録層用組成物中には、更に必要に応じて、感度を高めるための環状酸無水物、フェノール類、有機酸類；露光後直ちに可視像を得るための焼き出し剤、画像着色剤としての染料、その他のフィラー等を含有させることができる。
【０１７８】
環状酸無水物としては米国特許第４，１１５，１２８号明細書に記載されているように無水フタル酸、テトラヒドロ無水フタル酸、ヘキサヒドロ無水フタル酸、３，６−エンドオキシ−Δ4 −テトラヒドロ無水フタル酸、テトラクロル無水フタル酸、無水マレイン酸、クロル無水マレイン酸、α−フェニル無水マレイン酸、無水コハク酸、無水ピロメリット酸等がある。
フェノール類としては、ビスフェノールＡ、ｐ−ニトロフェノール、ｐ−エトキシフェノール、２，３，４−トリヒドロキシベンゾフェノン、４−ヒドロキシベンゾフェノン、２，４，４′−トリヒドロキシベンゾフェノン、４，４′，４″−トリヒドロキシ−トリフェニルメタン、４，４′，３″，４″−テトラヒドロキシ−３，５，３′，５′−テトラメチルトリフェニルメタン等が挙げられる。
【０１７９】
有機酸類としては、特開昭６０−８８９４２号公報、特開平２−９６７５５号公報等に記載されている、スルホン酸類、スルフィン酸類、アルキル硫酸類、ホスホン酸類、ホスフィン酸類、リン酸エステル類、カルボン酸類等があり、具体的には、ｐ−トルエンスルホン酸、ドデシルベンゼンスルホン酸、ｐ−トルエンスルフィン酸、エチル硫酸、フェニルホスホン酸、フェニルホスフィン酸、リン酸フェニル、リン酸ジフェニル、安息香酸、イソフタル酸、アジピン酸、ｐ−トルイル酸、３，４−ジメトキシ安息香酸、フタル酸、テレフタル酸、１，４−シクロヘキセン−２，２−ジカルボン酸、エルカ酸、ラウリン酸、ｎ−ウンデカン酸、アスコルビン酸等が挙げられる。
上記の環状酸無水物類、フェノール類、有機酸類の画像記録層用組成物中に占める割合は、０．０５〜１５質量％が好ましく、より好ましくは、０．１〜５質量％である。
【０１８０】
露光後、直ちに可視像を得るための焼き出し剤としては、露光によって酸を放出する感光性化合物と、酸と塩を形成して色調を変える有機染料との組み合わせを挙げることができる。
露光によって酸を放出する感光性化合物は、光分解して酸性物質を発生する化合物の光分解生成物である。例えば、特開昭５０−３６２０９号公報に記載されているｏ−ナフトキノンジアジド−４−スルホン酸ハロゲニド；特開昭５３−３６２２３号公報に記載されているトリハロメチル−２−ビロンやトリハロメチル−ｓ−トリアジン；特開昭５５−６２４４４号公報に記載されている種々のｏ−ナフトキノンジアジド化合物；特開昭５５−７７７４２号公報に記載されている２−トリハロメチル−５−アリール−１，３，４−オキサジアゾール化合物；ジアゾニウム塩等を挙げることができる。
これらの化合物は、単独でまたは混合して使用することができ、その添加量は、組成物全質量に対し、０．３〜１５質量％の範囲が好ましい。
【０１８１】
酸と塩を形成して色調を変える有機染料は、上記感光性化合物と相互作用することによってその色調を変える有機染料である。
このような有機染料としては、ジフェニルメタン系、トリアリールメタン系、チアジン系、オキサジン系、フェナジン系、キサンテン系、アントラキノン系、イミノナフトキノン系、アゾメチン系の色素を用いることができる。
【０１８２】
具体的には、例えば、ブリリアントグリーン、エオシン、エチルバイオレット、エリスロシンＢ、メチルグリーン、クリスタルバイオレット、ベイシックフクシン、フェノールフタレイン、１，３−ジフェニルトリアジン、アリザリンレッドＳ、チモールフタレイン、メチルバイオレット２Ｂ、キナルジンレッド、ローズベンガル、チモールスルホフタレイン、キシレノールブルー、メチルオレンジ、オレンジＩＶ、ジフェニルチオカルバゾン、２，７−ジクロロフルオレセイン、パラメチルレッド、コンゴーレッド、ベンゾプルプリン４Ｂ、α−ナフチルレッド、ナイルブルー２Ｂ、ナイルブルーＡ、フエナセタリン、メチルバイオレット、マラカイトグリーン、パラフクシン、オイルブルー＃６０３〔オリエント化学工業（株）製〕、オイルピンク＃３１２〔オリエント化学工業（株）製〕、オイルレッド５Ｂ〔オリエント化学工業（株）製〕、オイルスカーレット＃３０８〔オリエント化学工業（株）製〕、オイルレッドＯＧ〔オリエント化学工業（株）製〕、オイルレッドＲＲ〔オリエント化学工業（株）製〕、オイルグリーン＃５０２〔オリエント化学工業（株）製〕、スピロンレッドＢＥＨスペシャル〔保土谷化学工業（株）製〕、ビクトリアピュアーブルーＢＯＨ〔保土谷化学工業（株）製〕、パテントピュア−ブルー〔住友三国化学工業（株）製〕、スーダンブルーII〔ＢＡＳＦ社製〕、ｍ−クレゾールパープル、クレゾールレッド、ローダミンＢ、ローダミン６Ｇ、ファーストアッシドバイオレットＲ、スルホローダミンＢ、オーラミン、４−ｐ−ジエチルアミノフェニルイミノナフトキノン、２−カルボキシアニリノ−４−ｐ−ジエチルアミノフェニルイミノナフトキノン、２−カルボステアリルアミノ−４−ｐ−ジヒドロオキシエチル−アミノ−フェニルイミノナフトキノン、ｐ−メトキシベンゾイル−ｐ′−ジエチルアミノ−ｏ′−メチルフェニルイミノアセトアニリド、シアノ−ｐ−ジエチルアミノフェニルイミノアセトアニリド、１−フェニル−３−メチル−４−ｐ−ジエチルアミノフェニルイミノ−５−ピラゾロン、１−β−ナフチル−４−ｐ−ジエチルアミノフェニルイミノ−５−ピラゾロンが挙げられる。
【０１８３】
特に好ましい有機染料は、トリアリールメタン系染料である。トリアリールメタン系染料では、特開昭６２−２９３２４７１号公報、特許第２９６９０２１号公報に記載されているような対アニオンとしてスルホン酸化合物を有するものが特に有用である。
これらの染料は単独でまたは混合して使用することができ、添加量は画像記録層用組成物の総質量に対して０．３〜１５質量％が好ましい。また必要に応じて他の染料、顔料と併用でき、その使用量は染料および顔料の総質量に対して７０質量％以下、より好ましくは５０質量％以下である。
【０１８４】
画像記録層用組成物中には、画像のインキ着肉性を向上させるための疎水基を有する各種樹脂、例えば、オクチルフェノール−ホルムアルデヒド樹脂、ｔ−ブチルフェノール−ホルムアルデヒド樹脂、ｔ−ブチルフェノール−ベンズアルデヒド樹脂、ロジン変性ノボラック樹脂、これら変性ノボラック樹脂のｏ−ナフトキノンジアジドスルホン酸エステル等；塗膜の可撓性を改良するための可塑剤、例えば、フタル酸ジブチル、フタル酸ジオクチル、ブチルグリコレート、リン酸トリクレジル、アジピン酸ジオクチル等の各種添加剤を種々の目的に応じて含有させることができる。これらの添加量は組成物全質量に対して、０．０１〜３０質量％の範囲が好ましい。
【０１８５】
組成物中には、皮膜の耐摩耗性を更に向上させるための公知の樹脂を含有させることができる。これらの樹脂としては、例えば、ポリビニルアセタール樹脂、ポリウレタン樹脂、エポキシ樹脂、塩化ビニル樹脂、ナイロン、ポリエステル樹脂、アクリル樹脂が挙げられる。これらは単独でまたは混合して使用することができる。添加量は組成物全質量に対して、２〜４０質量％の範囲が好ましい。
【０１８６】
組成物中には、現像のラチチュードを広げるために、特開昭６２−２５１７４０号公報および特開平４−６８３５５号公報に記載されているような非イオン性界面活性剤、特開昭５９−１２１０４４号公報および特開平４−１３１４９号公報に記載されているような両性界面活性剤を添加することができる。
【０１８７】
非イオン性界面活性剤の具体例としては、ポリエチレングリコールおよびその誘導体類、ポリエチレングリコールポリプロピレングリコールエーテル誘導体類、ポリエチレングリコールポリプロピレングリコールブロックコポリマー類、ポリエチレングリコールアルキルエーテル類、ポリエチレングリコールポリプロピレングリコールアルキルエーテル類、ポリエチレングリコールアルキルフェニルエーテル類、ポリエチレングリコール脂肪酸エステル類、ポリプロピレングリコール脂肪酸エステル類、ポリエチレングリコールアルキルアミン類、ポリエチレングリコールアルキルアミノエーテル類、ポリプロピレングリコールグリセリルエーテル類、グリセリン脂肪酸エステルおよびそのポリエチレンオキサイド付加物類、ソルビタン脂肪酸エステルおよびそのポリエチレンオキサイド付加物類、ソルビット脂肪酸エステルおよびそのポリエチレンオキサイド付加物類、ペンタエリスリット脂肪酸エステルおよびそのポリエチレンオキサイド付加物類、グリセロールボレイド脂肪酸エステルおよびそのポリエチレンオキサイド付加物類、脂肪酸アルカノールアミドおよびそのポリエチレンオキサイド付加物類、ポリグリセリン脂肪酸エステル類、フィトステロールのポリエチレンオキサイド付加物類、フィトスタノールのポリエチレンオキサイド付加物類、植物油のポリエチレンオキサイド付加物類、ラノリンのポリエチレンオキサイド付加物類、ラノリンアルコールのポリエチレンオキサイド付加物類、密蝋誘導体のポリエチレンオキサイド付加物類、アルキルフェニルホルムアルデヒド縮合体のポリエチレンオキサイド付加物類、パーフルオロ基を側鎖に有するアクリル系オリゴマーであるフッ素系界面活性剤等が挙げられる。
【０１８８】
両性界面活性剤の具体例としては、アルキルジ（アミノエチル）グリシン、アルキルポリアミノエチルグリシン塩酸塩、アモーゲンＫ（商品名、第一工業製薬（株）製、Ｎ−テトラデシル−Ｎ，Ｎ−ベタイン型）、２−アルキル−Ｎ−カルボキシエチル−Ｎ−ヒドロキシエチルイミダゾリニウムベタイン、レボン１５（商品名、三洋化成（株）製、アルキルイミダゾリン系）が挙げられる。
上記非イオン性界面活性剤および両性界面活性剤の画像記録層用組成物中に占める割合は０．０５〜１５質量％が好ましく、より好ましくは、０．１〜５質量％である。
【０１８９】
組成物中には、塗布面質を向上させるための界面活性剤、例えば、特開昭６２−１７０９５０号公報に記載されているようなフッ素系界面活性剤を含有させることができる。
好ましい添加量は、全組成物の０．００１〜１．０質量％であり、更に好ましくは０．００５〜０．５質量％である。
【０１９０】
組成物中には、黄色系染料を含有させることができる。中でも、４１７ｎｍの吸光度が４３６ｎｍの吸光度の７０％以上である黄色系染料が好ましい。
【０１９１】
画像記録層用組成物から平版印刷版原版を得る場合には、上述した平版印刷版用支持体上に画像記録層として設ける。画像記録層用組成物は、下記の有機溶剤の１種または２種以上を混合したものに溶解され、または分散され、支持体に塗布されて乾燥される。
有機溶剤としては、公知のものを用いることができるが、沸点４０〜２００℃、特に６０〜１６０℃の範囲のものが、乾燥の際における有利さから選択される。
【０１９２】
有機溶剤としては、例えば、メチルアルコール、エチルアルコール、ｎ−またはイソ−プロピルアルコール、ｎ−またはイソ−ブチルアルコール、ジアセトンアルコール等のアルコール類；アセトン、メチルエチルケトン、メチルプロピルケトン、メチルブチルケトン、メチルアミルケトン、メチルヘキシルケトン、ジエチルケトン、ジイソブチルケトン、シクロヘキサノン、メチルシクロヘキサノン、アセチルアセトン等のケトン類；ベンゼン、トルエン、キシレン、シクロヘキサン、メトキシベンゼン等の炭化水素類；エチルアセテート、ｎ−またはイソ−プロピルアセテート、ｎ−またはイソ−ブチルアセテート、エチルブチルアセテート、ヘキシルアセテート等の酢酸エステル類；メチレンジクロライド、エチレンジクロライド、モノクロルベンゼン等のハロゲン化物；イソプロピルエーテル、ｎ−ブチルエーテル、ジオキサン、ジメチルジオキサン、テトラヒドロフラン等のエーテル類；エチレングリコール、メチルセロソルブ、メチルセロソルブアセテート、エチルセロソルブ、ジエチルセロソルブ、セロソルブアセテート、ブチルセロソルブ、ブチルセロソルブアセテート、メトキシメトキシエタノール、ジエチレングリコールモノメチルエーテル、ジエチレングリコールジメチルエーテル、ジエチレングリコールメチルエチルエーテル、ジエチレングリコールジエチルエーテル、プロピレングリコール、プロピレングリコールモノメチルエーテル、プロピレングリコールモノメチルエーテルアセテート、プロピレングリコールモノエチルエーテル、プロピレングリコールモノエチルエーテルアセテート、プロピレングリコールモノブチルエーテル、３−メチル−３−メトキシブタノール等の多価アルコールとその誘導体；ジメチルスルホキシド、Ｎ，Ｎ−ジメチルホルムアミド等の特殊溶剤が挙げられる。これらは単独でまたは混合して使用される。塗布する組成物中の固形分の濃度は、２〜５０質量％とするのが適当である。
【０１９３】
［平版印刷版原版の製造］
画像記録層用組成物の塗布方法としては、例えば、ロールコーティング、ディップコーティング、エアナイフコーティング、グラビアコーティング、グラビアオフセットコーティング、ホッパーコーティング、ブレードコーティング、ワイヤドクターコーティング、スプレーコーティング等の方法が用いられる。塗布量は、乾燥後の質量にして０．３〜４．０ｇ／ｍ² が好ましい。塗布量が小さくなるにつれて画像を得るための露光量は小さくて済むが、膜強度は低下する。塗布量が大きくなるにつれ、露光量を必要とするが感光膜は強くなり、耐刷性が向上する。
【０１９４】
支持体上に塗布された画像記録層用組成物の乾燥は、通常加熱された空気によって行われる。加熱は３０〜２００℃、特に、４０〜１４０℃の範囲が好適である。乾燥の温度は乾燥中一定に保たれる方法だけでなく段階的に上昇させる方法も実施しうる。また、乾燥風は除湿することによって好結果が得られる場合もある。加熱された空気は、塗布面に対し０．１〜３０ｍ／秒、特に０．５〜２０ｍ／秒の割合で供給するのが好適である。
【０１９５】
＜バックコート＞
支持体の裏面には、必要に応じてバックコートが設けられる。かかるバックコートとしては特開平５−４５８８５号公報に記載されている有機高分子化合物および特開平６−３５１７４号公報に記載されている有機金属化合物または無機金属化合物を加水分解させ、重縮合させて得られる金属酸化物からなる被覆層が好ましく用いられる。これらの被覆層のうち、Ｓｉ（ＯＣＨ₃ ）₄ Ｓｉ（ＯＣ₂ Ｈ₅ ）₄ 、Ｓｉ（ＯＣ₃ Ｈ₇ ）₄ 、Ｓｉ（ＯＣ₄ Ｈ₉ ）₄ 等のケイ素のアルコキシ化合物が安価で入手しやすく、それから得られる金属酸化物の被覆層が耐現像液性に優れており特に好ましい。
【０１９６】
［平版印刷版の製造］
＜露光＞
上記のようにして作成された平版印刷版原版は、通常、像露光、現像処理を施される。像露光に用いられる活性光線の光源としては、近赤外から赤外領域に発光波長を持つ光源が好ましく、固体レーザ、半導体レーザが特に好ましい。
【０１９７】
＜現像液＞
本発明の平版印刷版原版の現像処理に好適に用いられる現像液は、ｐＨ９．０〜１３．５、好ましくはｐＨ１０．０〜１３．２の現像液である。現像液（以下、補充液も含めて「現像液」という。）には、従来公知のアルカリ水溶液が使用できる。
例えば、ケイ酸ナトリウム、ケイ酸カリウム、第三リン酸ナトリウム、第三リン酸カリウム、第三リン酸アンモニウム、第二リン酸ナトリウム、第二リン酸カリウム、第二リン酸アンモニウム、炭酸ナトリウム、炭酸カリウム、炭酸アンモニウム、炭酸水素ナトリウム、炭酸水素カリウム、炭酸水素アンモニウム、ホウ酸ナトリウム、ホウ酸カリウム、ホウ酸アンモニウム、水酸化ナトリウム、水酸化アンモニウム、水酸化カリウムおよび水酸化リチウム等の無機アルカリ塩が挙げられる。
【０１９８】
また、モノメチルアミン、ジメチルアミン、トリメチルアミン、モノエチルアミン、ジエチルアミン、トリエチルアミン、モノイソプロピルアミン、ジイソプロピルアミン、トリイソプロピルアミン、ｎ−ブチルアミン、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、モノイソプロパノールアミン、ジイソプロパノールアミン、エチレンイミン、エチレンジアミン、ピリジン等の有機アルカリ剤も挙げられる。
これらのアルカリ水溶液は、１種単独で用いてもよいし、２種以上を併用してもよい。
【０１９９】
上記のアルカリ水溶液のうち、アルカリ金属ケイ酸塩を実質的に含有せず、非還元糖と塩基とを含有するｐＨ９．０〜１３．５の現像液を用いるのが好ましい。この現像液（いわゆる「ノンシリケート現像液」）を用いると、現像時にカスやヘドロの発生を防止することができるため、現像液の安定性が大幅に向上する。また、画像記録層の表面を劣化させることがなく、かつ画像記録層の着肉性をより良好な状態に維持することができる。
【０２００】
この現像液は、主成分として、少なくとも１種の非還元糖と、少なくとも１種の塩基とを含有し、かつ、ｐＨ９．０〜１３．５であるのが好ましい。
非還元糖とは、遊離のアルデヒド基およびケトン基を有さず、還元性を示さない糖類である。具体的には、還元基同士の結合したトレハロース型少糖類、糖類の還元基と非糖類が結合した配糖体および糖類に水素添加して還元した糖アルコールに分類され、いずれも好適に用いられる。
トレハロース型少糖類としては、例えば、サッカロース、トレハロースが挙げられる。
配糖体としては、例えば、アルキル配糖体、フェノール配糖体、カラシ油配糖体が挙げられる。
糖アルコールとしては、例えば、Ｄ，Ｌ−アラビット、リビット、キシリット、Ｄ，Ｌ−ソルビット、Ｄ，Ｌ−マンニット、Ｄ，Ｌ−イジット、Ｄ，Ｌ−タリット、ズリシットおよびアロズルシットが挙げられる。
【０２０１】
また、非還元糖としては、二糖類の水素添加で得られるマルチトール、および、オリゴ糖の水素添加で得られる還元体（還元水あめ）も好適に用いられる。
【０２０２】
中でも、特に好ましい非還元糖は、糖アルコール、サッカロース、還元水あめであり、特に、Ｄ−ソルビット、サッカロース、還元水あめが適度なｐＨ領域に緩衝作用があることと、低価格であることで好ましい。
これらの非還元糖は、単独でまたは２種以上を組み合わせて使用でき、それらの現像液中に占める割合は０．１〜３０質量％が好ましく、更に好ましくは、１〜２０質量％である。濃度が低すぎると、十分な緩衝作用が得られない場合がある。濃度が高すぎると、高濃縮化しにくく、また原価アップの問題が出てくる。なお、還元糖を塩基と組み合わせて使用した場合、経時的に褐色に変色し、ｐＨも徐々に下がり、よって現像性が低下するという問題点がある。
【０２０３】
非還元糖に組み合わせる塩基としては、従来公知のアルカリ剤が使用できる。例えば、水酸化ナトリウム、水酸化カリウム、水酸化リチウム、リン酸三ナトリウム、リン酸三カリウム、リン酸三アンモニウム、リン酸二ナトリウム、リン酸二カリウム、リン酸二アンモニウム、炭酸ナトリウム、炭酸カリウム、炭酸アンモニウム、炭酸水素ナトリウム、炭酸水素カリウム、炭酸水素アンモニウム、ホウ酸ナトリウム、ホウ酸カリウム、ホウ酸アンモニウム等の無機アルカリ剤が挙げられる。
また、モノメチルアミン、ジメチルアミン、トリメチルアミン、モノエチルアミン、ジエチルアミン、トリエチルアミン、モノイソプロピルアミン、ジイソプロピルアミン、トリイソプロピルアミン、ｎ−ブチルアミン、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、モノイソプロパノールアミン、ジイソプロパノールアミン、エチレンイミン、エチレンジアミン、ピリジン等の有機アルカリ剤も挙げられる。
これらのアルカリ剤は単独でまたは２種以上を組み合わせて用いられる。
【０２０４】
これらの中で好ましいのは水酸化ナトリウム、水酸化カリウムである。その理由は、非還元糖に対するこれらの量を調整することにより広いｐＨ領域でｐＨ調整が可能となるためである。また、リン酸三ナトリウム、リン酸三カリウム、炭酸ナトリウム、炭酸カリウム等もそれ自身に緩衝作用があるので好ましい。
これらのアルカリ剤は現像液のｐＨを９．０〜１３．５の範囲になるように添加され、その添加量は所望のｐＨならびに非還元糖の種類および添加量によって決められるが、より好ましいｐＨ範囲は１０．０〜１３．２である。
【０２０５】
現像液には、更に、糖類以外の弱酸と強塩基とからなるアルカリ性緩衝液を併用することができる。かかる緩衝液として用いられる弱酸としては、解離定数（ｐＫａ）が１０．０〜１３．２のものが好ましい。
このような弱酸は、Ｐｅｒｇａｍｏｎ Ｐｒｅｓｓ社発行の「ＩＯＮＩＳＡＴＩＯＮ ＣＯＮＳＴＡＮＴＳ ＯＦ ＯＲＧＡＮＩＣ ＡＣＩＤＳ ＩＮ ＡＱＵＥＯＵＳ ＳＯＬＵＴＩＯＮ」等に記載されているものから選ぶことができる。
【０２０６】
例えば、２，２，３，３−テトラフルオロプロパノール−１（ｐＫａ１２．７４）、トリフルオロエタノール（同１２．３７）、トリクロロエタノール（同１２．２４）等のアルコール類、ピリジン−２−アルデヒド（同１２．６８）、ピリジン−４−アルデヒド（同１２．０５）等のアルデヒド類、サリチル酸（同１３．０）、３−ヒドロキシ−２−ナフトエ酸（同１２．８４）、カテコール（同１２．６）、没食子酸（同１２．４）、スルホサリチル酸（同１１．７）、３，４−ジヒドロキシスルホン酸（同１２．２）、３，４−ジヒドロキシ安息香酸（同１１．９４）、１，２，４−トリヒドロキシベンゼン（同１１．８２）、ハイドロキノン（同１１．５６）、ピロガロール（同１１．３４）、ｏ−クレゾール（同１０．３３）、レゾルシノール（同１１．２７）、ｐ−クレゾール（同１０．２７）、ｍ−クレゾール（同１０．０９）等のフェノール性ヒドロキシ基を有する化合物、２−ブタノンオキシム（同１２．４５）、アセトキシム（同１２．４２）、１，２−シクロヘプタンジオンジオキシム（同１２．３）、２−ヒドロキシベンズアルデヒドオキシム（同１２．１０）、ジメチルグリオキシム（同１１．９）、エタンジアミドジオキシム（同１１．３７）、アセトフェノンオキシム（同１１．３５）等のオキシム類、アデノシン（同１２．５６）、イノシン（同１２．５）、グアニン（同１２．３）、シトシン（同１２．２）、ヒポキサンチン（同１２．１）、キサンチン（同１１．９）等の核酸関連物質、他に、ジエチルアミノメチルホスホン酸（同１２．３２）、１−アミノ−３，３，３−トリフルオロ安息香酸（同１２．２９）、イソプロピリデンジホスホン酸（同１２．１０）、１，１−エチリデンジホスホン酸（同１１．５４）、１，１−エチリデンジホスホン酸１−ヒドロキシ（同１１．５２）、ベンズイミダゾール（同１２．８６）、チオベンズアミド（同１２．８）、ピコリンチオアミド（同１２．５５）、バルビツル酸（同１２．５）等の弱酸が挙げられる。
【０２０７】
これらの弱酸の中で好ましいのは、スルホサリチル酸、サリチル酸である。これらの弱酸に組み合わせる塩基としては、水酸化ナトリウム、水酸化アンモニウム、水酸化カリウムおよび水酸化リチウムが好適に用いられる。これらのアルカリ剤は単独でまたは２種以上を組み合わせて用いられる。上記の各種アルカリ剤は濃度および組み合わせによりｐＨを好ましい範囲内に調整して使用される。
【０２０８】
現像液には、現像性の促進、現像カスの分散および印刷版画像部の親インキ性の向上を目的として、必要に応じて、アルキレンオキシド付加化合物、界面活性剤、有機溶剤等を添加できる。
アルキレンオキシド付加化合物としてはポリオキシエチレンソルビタン、ポリオキシエチレンソルビトール、ポリオキシエチレングリセリン、ポリオキシエチレントリエタノールアミン等が挙げられる。
好ましい界面活性剤としては、アニオン系、カチオン系、ノニオン系および両性の界面活性剤が挙げられる。
【０２０９】
界面活性剤の好ましい例としては、ポリオキシエチレンアルキルエーテル類、ポリオキシエチレンアルキルフェニルエーテル類、ポリオキシエチレンポリスチリルフェニルエーテル類、ポリオキシエチレンポリオキシプロピレンアルキルエーテル類、グリセリン脂肪酸部分エステル類、ソルビタン脂肪酸部分エステル類、ペンタエリスリトール脂肪酸部分エステル類、プロピレングリコールモノ脂肪酸エステル類、ショ糖脂肪酸部分エステル類、ポリオキシエチレンソルビタン脂肪酸部分エステル類、ポリオキシエチレンソルビトール脂肪酸部分エステル類、ポリエチレングリコール脂肪酸エステル類、ポリグリセリン脂肪酸部分エステル類、ポリオキシエチレン化ひまし油類、ポリオキシエチレングリセリン脂肪酸部分エステル類、脂肪酸ジエタノールアミド類、Ｎ，Ｎ−ビス−２−ヒドロキシアルキルアミン類、ポリオキシエチレンアルキルアミン、トリエタノールアミン脂肪酸エステル、トリアルキルアミンオキシド等のノニオン性界面活性剤；
【０２１０】
脂肪酸塩類、アビエチン酸塩類、ヒドロキシアルカンスルホン酸塩類、アルカンスルホン酸塩類、ジアルキルスルホコハク酸エステル塩類、直鎖アルキルベンゼンスルホン酸塩類、分岐鎖アルキルベンゼンスルホン酸塩類、アルキルナフタレンスルホン酸塩類、アルキルフェノキシポリオキシエチレンプロピルスルホン酸塩類、ポリオキシエチレンアルキルスルホフェニルエーテル塩類、Ｎ−メチル−Ｎ−オレイルタウリンナトリウム塩、Ｎ−アルキルスルホコハク酸モノアミド二ナトリウム塩、石油スルホン酸塩類、硫酸化牛脂油、脂肪酸アルキルエステルの硫酸エステル塩類、アルキル硫酸エステル塩類、ポリオキシエチレンアルキルエーテル硫酸エステル塩類、脂肪酸モノグリセリド硫酸エステル塩類、ポリオキシエチレンアルキルフェニルエーテル硫酸エステル塩類、ポリオキシエチレンスチリルフェニルエーテル硫酸エステル塩類、アルキルリン酸エステル塩類、ポリオキシエチレンアルキルエーテルリン酸エステル塩類、ポリオキシエチレンアルキルフェニルエーテルリン酸エステル塩類、スチレン／無水マレイン酸共重合物の部分けん化物類、オレフィン／無水マレイン酸共重合物の部分けん化物類、ナフタレンスルホン酸塩ホルマリン縮合物類等のアニオン界面活性剤；
【０２１１】
アルキルアミン塩類、テトラブチルアンモニウムブロミド等の第四級アンモニウム塩類、ポリオキシエチレンアルキルアミン塩類、ポリエチレンポリアミン誘導体等のカチオン性界面活性剤；
カルボキシベタイン類、アミノカルボン酸類、スルホべタイン類、アミノ硫酸エステル類、イミダゾリン類等の両性界面活性剤が挙げられる。
以上に例示した界面活性剤の中で「ポリオキシエチレン」とあるものは、ポリオキシメチレン、ポリオキシプロピレン、ポリオキシブチレン等の「ポリオキシアルキレン」に読み替えることもでき、それらの界面活性剤もまた包含される。
【０２１２】
更に好ましい界面活性剤は、分子内にパーフルオロアルキル基を含有するフッ素系の界面活性剤である。フッ素系界面活性剤としては、例えば、パーフルオロアルキルカルボン酸塩、パーフルオロアルキルスルホン酸塩、パーフルオロアルキルリン酸エステル等のアニオン型；パーフルオロアルキルベタイン等の両性型；パーフルオロアルキルトリメチルアンモニウム塩等のカチオン型；パーフルオロアルキルアミンオキサイド、パーフルオロアルキルエチレンオキシド付加物、パーフルオロアルキル基および親水性基含有オリゴマー、パーフルオロアルキル基および親油性基含有オリゴマー、パーフルオロアルキル基、親水性基および親油性基含有オリゴマー、パーフルオロアルキル基および親油性基含有ウレタン等のノニオン型が挙げられる。
【０２１３】
上記の界面活性剤は、単独でまたは２種以上を組み合わせて使用することができ、現像液中に０．００１〜１０質量％、より好ましくは０．０１〜５質量％の範囲で添加される。
【０２１４】
現像液には、種々の現像安定化剤を用いることができる。好ましい例として、特開平６−２８２０７９号公報に記載されている糖アルコールのポリエチレングリコール付加物、テトラブチルアンモニウムヒドロキシド等のテトラアルキルアンモニウム塩、テトラブチルホスホニウムブロマイド等のホスホニウム塩およびジフェニルヨードニウムクロライド等のヨードニウム塩が挙げられる。
更には、特開昭５０−５１３２４号公報に記載されているアニオン界面活性剤または両性界面活性剤、特開昭５５−９５９４６号公報に記載されている水溶性カチオニックポリマー、特開昭５６−１４２５２８号公報に記載されている水溶性の両性高分子電解質を挙げることができる。
更に、特開昭５９−８４２４１号公報のアルキレングリコールが付加された有機ホウ素化合物、特開昭６０−１１１２４６号公報に記載されているポリオキシエチレンブロック重合型またはポリオキシプロピレンブロック重合型の水溶性界面活性剤、特開昭６０−１２９７５０号公報のポリオキシエチレンまたはポリオキシプロピレンを置換したアルキレンジアミン化合物、特開昭６１−２１５５５４号公報に記載されている重量平均分子量３００以上のポリエチレングリコール、特開昭６３−１７５８５８号公報のカチオン性基を有する含フッ素界面活性剤、特開平２−３９１５７号公報の酸またはアルコールに４モル以上のエチレンオキシドを付加して得られる水溶性エチレンオキシド付加化合物と水溶性ポリアルキレン化合物等が挙げられる。
【０２１５】
有機溶剤としては、水に対する溶解度が約１０質量％以下のものが適しており、好ましくは５質量％以下のものから選ばれる。例えば、１−フェニルエタノール、２−フェニルエタノール、３−フェニル−１−プロパノール、４−フェニル−１−ブタノール、４−フェニル−２−ブタノール、２−フェニル−１−ブタノール、２−フェノキシエタノール、２−ベンジルオキシエタノール、ｏ−メトキシベンジルアルコール、ｍ−メトキシベンジルアルコール、ｐ−メトキシベンジルアルコール、ベンジルアルコール、シクロヘキサノール、２−メチルシクロヘキサノール、３−メチルシクロヘキサノールおよび４−メチルシクロヘキサノール、Ｎ−フェニルエタノールアミンおよびＮ−フェニルジエタノールアミン等を挙げることができる。
【０２１６】
有機溶剤の含有量は使用液の総質量に対して０．１〜５質量％である。その使用量は界面活性剤の使用量と密接な関係があり、有機溶剤の量が増すにつれ、界面活性剤の量は増加させることが好ましい。これは界面活性剤の量が少なく、有機溶剤の量を多く用いると有機溶剤が完全に溶解せず、したがって、良好な現像性の確保が期待できなくなるからである。
【０２１７】
現像液には更に還元剤を加えることができる。これは印刷版の汚れを防止するものである。好ましい有機還元剤としては、チオサリチル酸、ハイドロキノン、メトール、メトキシキノン、レゾルシン、２−メチルレゾルシン等のフェノール化合物、フェニレンジアミン、フェニルヒドラジン等のアミン化合物が挙げられる。更に好ましい無機の還元剤としては、亜硫酸、亜硫酸水素酸、亜リン酸、亜リン酸水素酸、亜リン酸二水素酸、チオ硫酸および亜ジチオン酸等の無機酸のナトリウム塩、カリウム塩、アンモニウム塩等を挙げることができる。
これらの還元剤のうち汚れ防止効果が特に優れているのは亜硫酸塩である。これらの還元剤は使用時の現像液に対して好ましくは、０．０５〜５質量％の範囲で含有される。
【０２１８】
現像液には更に有機カルボン酸を加えることもできる。好ましい有機カルボン酸は炭素原子数６〜２０の脂肪族カルボン酸および芳香族カルボン酸である。脂肪族カルボン酸の具体的な例としては、カプロン酸、エナンチル酸、カプリル酸、ラウリン酸、ミリスチン酸、パルミチン酸およびステアリン酸等があり、特に好ましいのは炭素数８〜１２のアルカン酸である。また炭素鎖中に二重結合を有する不飽和脂肪酸でも、枝分かれした炭素鎖のものでもよい。芳香族カルボン酸としてはベンゼン環、ナフタレン環、アントラセン環等にカルボキシ基が置換された化合物で、具体的には、ｏ−クロロ安息香酸、ｐ−クロロ安息香酸、ｏ−ヒドロキシ安息香酸、ｐ−ヒドロキシ安息香酸、ｏ−アミノ安息香酸、ｐ−アミノ安息香酸、２，４−ジヒドロシ安息香酸、２，５−ジヒドロキシ安息香酸、２，６−ジヒドロキシ安息香酸、２，３−ジヒドロキシ安息香酸、３，５−ジヒドロキシ安息香酸、没食子酸、１−ヒドロキシ−２−ナフトエ酸、３−ヒドロキシ−２−ナフトエ酸、２−ヒドロキシ−１−ナフトエ酸、１−ナフトエ酸、２−ナフトエ酸等があるがヒドロキシナフトエ酸は特に有効である。
【０２１９】
上記脂肪族および芳香族カルボン酸は水溶性を高めるためにナトリウム塩やカリウム塩またはアンモニウム塩として用いるのが好ましい。本発明で用いる現像液の有機カルボン酸の含有量は特に限定されないが、０．１質量％より低いと効果が十分でなく、また１０質量％以上ではそれ以上の効果の改善が図れないばかりか、別の添加剤を併用する時に溶解を妨げることがある。したがって、好ましい添加量は使用時の現像液に対して０．１〜１０質量％であり、より好ましくは０．５〜４質量％である。
【０２２０】
現像液には、更に必要に応じて、防腐剤、着色剤、増粘剤、消泡剤、硬水軟化剤等を含有させることもできる。
硬水軟化剤としては例えば、ポリリン酸およびそのナトリウム塩、カリウム塩およびアンモニウム塩、エチレンジアミンテトラ酢酸、ジエチレントリアミンペンタ酢酸、トリエチレンテトラミンヘキサ酢酸、ヒドロキシエチルエチレンジアミントリ酢酸、ニトリロトリ酢酸、１，２−ジアミノシクロヘキサンテトラ酢酸および１，３−ジアミノ−２−プロパノールテトラ酢酸等のアミノポリカルボン酸およびそれらのナトリウム塩、カリウム塩およびアンモニウム塩、アミノトリ（メチレンホスホン酸）、エチレンジアミンテトラ（メチレンホスホン酸）、ジエチレントリアミンペンタ（メチレンホスホン酸）、トリエチレンテトラミンヘキサ（メチレンホスホン酸）、ヒドロキシエチルエチレンジアミントリ（メチレンホスホン酸）、１−ヒドロキシタエン−１，１−ジホスホン酸、それらのナトリウム塩、カリウム塩およびアンモニウム塩を挙げることができる。
【０２２１】
このような硬水軟化剤はそのキレート化と使用される硬水の硬度および量によって最適値が変化するが、一般的な使用量を示せば、使用時の現像液に０．０１〜５質量％、より好ましくは０．０１〜０．５質量％の範囲である。添加量が少なすぎると添加の目的が十分に達成されず、多すぎると色抜け等の画像部への悪影響が発生する場合がある。現像液の残余の成分は水である。現像液は、使用時よりも水の含有量を少なくした濃縮液としておき、使用時に水で希釈するようにしておくことが運搬上有利である。この場合の濃縮度は、各成分が分離や析出を起こさない程度が適当である。
【０２２２】
この現像液には更に、現像性の促進や現像カスの分散および印刷版画像部の親インキ性を高める目的で必要に応じて、前述の種々の界面活性剤や有機溶剤を添加できる。
【０２２３】
＜後処理＞
上述した現像液で現像処理されて得られる平版印刷版は、水洗水、界面活性剤等を含有するリンス液、アラビアガム、デンプン誘導体等を主成分とするフィニッシャー、保護ガム液等で後処理を施される。平版印刷版の後処理にはこれらの処理を種々組み合わせて用いることができる。
【０２２４】
＜自動現像機＞
近年、型版および印刷業界では製版作業の合理化および標準化のため、平版印刷版原版用の自動現像機が広く用いられている。この自動現像機は、一般に現像部と後処理部からなり、平版印刷版原版を搬送する装置と、各処理液槽およびスプレー装置からなり、露光済みの平版印刷版原版を水平に搬送しながら、ポンプで汲み上げた各処理液をスプレーノズルから吹き付けて現像および後処理するものである。また、最近は処理液が満たされた処理液槽中に液中ガイドロール等によって平版印刷版原版を浸せき搬送させて現像処理する方法や、現像後一定量の少量の水洗水を版面に供給して水洗し、その廃水を現像液原液の希釈水としで再利用する方法も知られている。
このような自動処理においては、各処理液に処理量や稼動時間等に応じてそれぞれの補充液を補充しながら処理することができる。また、実質的に未使用の処理液で処理するいわゆる使い捨て処理方式も適用できる。
このような処理によって得られた平版印刷版は、印刷機に設置され、多数枚の印刷に用いられる。
【０２２５】
【実施例】
以下に実施例を示して本発明を具体的に説明するが、本発明はこれらに限られるものではない。
１．平版印刷版用支持体の作成
（平版印刷版用支持体Ａ）
厚さ０．３ｍｍのアルミニウム板（ＪＩＳ Ａ１０５０材）に、以下の（ａ）〜（ｇ）の各種表面処理を連続的に行い、平版印刷版用支持体Ａ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。
【０２２６】
（ａ）アルカリエッチング処理
上記で得られたアルミニウム板をカセイソーダ濃度３０ｇ／Ｌ、アルミニウムイオン濃度１０ｇ／Ｌ、温度６０℃の水溶液を用いてスプレーによるエッチング処理を１０秒間行い、アルミニウム板を０．５ｇ／ｍ² 溶解した。その後、スプレーによる水洗を行った。
【０２２７】
（ｂ）デスマット処理
温度３０℃の硝酸濃度１２ｇ／Ｌ水溶液（アルミニウムイオンを１０ｇ／Ｌ含む。）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。
【０２２８】
（ｃ）電気化学的粗面化処理
５０Ｈｚ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、塩酸１５ｇ／Ｌ水溶液（アルミニウムイオンを１０ｇ／Ｌ含む。）、温度３０℃であった。交流電源波形は正弦波であり、カーボン電極を対極として電気化学的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。補助陽極には電源から流れる電流の５％を分流させた。
電流密度は電流のピーク値で１６Ａ／ｄｍ² 、電気量はアルミニウム板が陽極時の電気量の総和で４００Ｃ／ｄｍ² であった。
その後、スプレーによる水洗を行った。
【０２２９】
（ｄ）アルカリエッチング処理
アルミニウム板をカセイソーダ濃度３６ｇ／Ｌ、アルミニウムイオン濃度１０ｇ／Ｌの水溶液を用いてスプレーによるエッチング処理を３５℃で１０秒間行い、アルミニウム板を０．１ｇ／ｍ² 溶解し、前段の交流を用いて電気化学的粗面化処理を行ったときに生成した水酸化アルミニウムを主体とするスマット成分を除去し、また、生成したピットのエッジ部分を溶解してエッジ部分を滑らかにした。その後、スプレーによる水洗を行った。
【０２３０】
（ｅ）デスマット処理
温度３０℃の硫酸濃度１５質量％水溶液（アルミニウムイオンを１０質量％含む。）で、スプレーによるデスマット処理を１０秒間行い、その後、スプレーによる水洗を行った。
【０２３１】
（ｆ）陽極酸化処理
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１０質量％（アルミニウムイオンを５．０質量％含む。）、温度２０℃であった。電流密度は６Ａ／ｄｍ² 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／ｍ² であった。
陽極酸化処理後の平版印刷版用支持体の表面粗さＲ_a は、０．４４μｍであった。
【０２３２】
（ｇ）アルカリ金属ケイ酸塩処理
陽極酸化処理後の平版印刷版用支持体を温度２０℃の３号ケイ酸ソーダの１．０質量％水溶液の処理槽の中に１０秒間浸せきさせることで、アルカリ金属ケイ酸塩処理（シリケート処理）を行った。その後、井水を用いたスプレーによる水洗を行った。
【０２３３】
（平版印刷版用支持体Ｂ）
上記（ｃ）において、電流密度を１２Ａ／ｄｍ² 、電気量を３００Ｃ／ｄｍ² とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｂを得た。陽極酸化処理後の平版印刷版用支持体の表面粗さＲ_a は、０．３４μｍであった。
【０２３４】
（平版印刷版用支持体Ｃ）
上記（ｃ）において、電流密度を２４Ａ／ｄｍ² 、電気量を６００Ｃ／ｄｍ² とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｃを得た。陽極酸化処理後の平版印刷版用支持体の表面粗さＲ_a は、０．３４μｍであった。
【０２３５】
（平版印刷版用支持体Ｄ）
上記（ｃ）において、図２に示した電解槽を使用して電気化学的粗面化処理を行い、上記（ｄ）において、カセイソーダ水溶液の温度を３０℃とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｄを得た。
【０２３６】
（平版印刷版用支持体Ｅ）
上記（ｃ）において、図２に示した電解槽を使用して電気化学的粗面化処理を行い、上記（ｄ）において、カセイソーダ水溶液の温度を４５℃とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｅを得た。
【０２３７】
（平版印刷版用支持体Ｆ）
上記（ｇ）において、３号ケイ酸ソーダ水溶液の濃度を０．２質量％とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｆを得た。
【０２３８】
（平版印刷版用支持体Ｇ）
上記（ｇ）において、３号ケイ酸ソーダ水溶液の濃度を２．５質量％とし、温度を５０℃とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｇを得た。
【０２３９】
（平版印刷版用支持体Ｈ）
上記（ｃ）において、電流密度を１２Ａ／ｄｍ² 、電気量を５０Ｃ／ｄｍ² とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｈを得た。陽極酸化処理後の平版印刷版用支持体の表面粗さＲ_a は、０．２４μｍであった。
【０２４０】
（平版印刷版用支持体Ｉ）
上記（ｇ）において、３号ケイ酸ソーダ水溶液の濃度を２．５質量％とし、温度を８０℃とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｉを得た。
【０２４１】
（平版印刷版用支持体Ｊ）
上記（ｇ）を行わなかった以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｊを得た。
【０２４２】
（平版印刷版用支持体Ｋ）
上記（ｄ）において、カセイソーダ水溶液の温度を６０℃とした以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｋを得た。
【０２４３】
（平版印刷版用支持体Ｌ）
上記（ａ）および（ｂ）の代わりに、下記（ｈ）、（ｉ）および（ｊ）を順次行った以外は、平版印刷版用支持体Ａと同様の方法で、平版印刷版用支持体Ｋを得た。陽極酸化処理後の平版印刷版用支持体の表面粗さＲ_a は、０．５５μｍであった。
【０２４４】
（ｈ）機械的粗面化処理
図１に示した装置を使って、研磨剤（ケイ砂）と水との懸濁液（比重１．１２）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。研磨剤の平均粒径は８μｍ、最大粒径は５０μｍ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φ３００ｍｍのステンレス製の筒に穴をあけて密になるように植毛した。回転ブラシは３本使用した。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７ｋＷ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２００ｒｐｍであった。
【０２４５】
（ｉ）アルカリエッチング処理
上記で得られたアルミニウム板をカセイソーダ濃度２６質量％、アルミニウムイオン濃度６．５質量％、温度７０℃の水溶液を用いてスプレーによるエッチング処理を１０秒間行い、アルミニウム板を６ｇ／ｍ² 溶解した。その後、スプレーによる水洗を行った。
【０２４６】
（ｊ）デスマット処理
温度３０℃の硝酸濃度１質量％水溶液（アルミニウムイオンを０．５質量％含む。）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。
【０２４７】
（平版印刷版用支持体Ｍ）
上記（ｈ）において、研磨剤として、ケイ砂の代わりに、平均粒径５０μｍ、最大粒径は１５０μｍのパミスを用い、ブラシの回転数を２５０ｒｐｍとし、上記（ｉ）において、アルミニウムの溶解量を８ｇ／ｍ² とし、上記（ｃ）、（ｄ）および（ｅ）の代わりに、下記（ｋ）、（ｌ）および（ｍ）を行った以外は、平版印刷版用支持体Ｌと同様の方法で、平版印刷版用支持体Ｍを得た。陽極酸化処理後の平版印刷版用支持体の表面粗さＲ_a は、０．５５μｍであった。
【０２４８】
（ｋ）電気化学的粗面化処理
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１０．５ｇ／Ｌ水溶液（アルミニウムイオンを５ｇ／Ｌ含む。）、温度５０℃であった。交流電源波形は図５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４に示すものを使用した。補助陽極には電源から流れる電流の５％を分流させた。
電流密度は電流のピーク値で３０Ａ／ｄｍ² 、電気量はアルミニウム板が陽極時の電気量の総和で２２０Ｃ／ｄｍ² であった。
その後、スプレーによる水洗を行った。
【０２４９】
（ｌ）アルカリエッチング処理
アルミニウム板をカセイソーダ濃度２６質量％、アルミニウムイオン濃度６．５質量％の水溶液を用いてスプレーによるエッチング処理を６０℃で行い、アルミニウム板を１．０ｇ／ｍ² 溶解し、前段の交流を用いて電気化学的粗面化処理を行ったときに生成した水酸化アルミニウムを主体とするスマット成分を除去し、また、生成したピットのエッジ部分を溶解してエッジ部分を滑らかにした。その後、スプレーによる水洗を行った。
【０２５０】
（ｍ）デスマット処理
温度３０℃の硫酸濃度１５質量％水溶液（アルミニウムイオンを４．５質量％含む。）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。
【０２５１】
（平版印刷版用支持体Ｎ）
上記（ｈ）を行わず、上記（ｌ）において、カセイソーダ水溶液の温度を３２℃とし、アルミニウム溶解量を０．２ｇ／ｍ² とした以外は、平版印刷版用支持体Ｍと同様の方法で、平版印刷版用支持体Ｎを得た。陽極酸化処理後の平版印刷版用支持体の表面粗さＲ_a は、０．２５μｍであった。
【０２５２】
２．平版印刷版用支持体の表面形状の測定
上記で得られた平版印刷版用支持体の表面のピットについて、下記（１）〜（３）の測定を行った。
結果を第１表に示す。なお、第１表中、「−」は、該当する平均開口径のピットがなかったことを示す。
（１）大ピットの平均開口径
ＳＥＭを用いて支持体の表面を真上から倍率１０００倍で撮影し、得られたＳＥＭ写真においてピットの周囲が環状に連なっている大ピットを５０個抽出し、その直径を読み取って開口径とし、平均開口径を算出した。
【０２５３】
（２）小ピットの平均開口径
高分解能ＳＥＭを用いて支持体の表面を真上から倍率５００００倍で撮影し、得られたＳＥＭ写真において小ピットを５０個抽出し、その直径を読み取って開口径とし、平均開口径を算出した。
【０２５４】
（３）小ピットの開口径に対する深さの比の平均
小ピットの開口径に対する深さの比の平均は、高分解能ＳＥＭを用いて支持体の破断面を倍率５００００倍で撮影し、得られたＳＥＭ写真において開口径０．８μｍ以下の小ピットを２０個抽出し、開口径と深さとを読み取って比を求めて平均値を算出した。
【０２５５】
３．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ΔＳ⁵⁰を求めた。
結果を第１表に示す。
【０２５６】
（１）原子間力顕微鏡による表面形状の測定
原子間力顕微鏡（ＳＰ１３７００、セイコー電子工業社製）により表面形状を測定し、３次元データを求めた。以下、具体的な手順を説明する。
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１２０〜１５０ｋＨｚ、バネ定数１２〜２０Ｎ／ｍのもの（ＡＣ−１６０ＴＳ、オリンパス社製）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、表面の５０μｍ□を５１２×５１２点測定した。ＸＹ方向の分解能は１．９μｍ、Ｚ方向の分解能は１ｎｍ、スキャン速度は６０μｍ／ｓｅｃとした。
【０２５７】
（２）ΔＳ⁵⁰の算出
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。表面積差ΔＳ⁵⁰は、得られた実面積Ｓ_x ⁵⁰と幾何学的測定面積Ｓ₀ ⁵⁰ とから、上記式（１）により求めた。
【０２５８】
４．平版印刷版用支持体の表面のＳｉ原子付着量の測定
各平版印刷版用支持体の表面のＳｉ原子付着量を蛍光Ｘ線分析装置を用い、検量線法により測定した。結果を第１表に示す。なお、第１表中の値は、アルミニウム板に含有されるＳｉ原子量を補正してある。
【０２５９】
検量線を作成するための標準試料としては、既知量のＳｉ原子を含有するケイ酸ナトリウム水溶液を、アルミニウム板の上の３０ｍｍφの面積内に均一に滴下した後、乾燥させたものを用いた。蛍光Ｘ線分析の条件を以下に示す。
【０２６０】
蛍光Ｘ線分析装置：理学電機工業社製ＲＩＸ３０００、Ｘ線管球：Ｒｈ、測定スペクトル：Ｓｉ−Ｋα、管電圧：５０ｋＶ、管電流：５０ｍＡ、スリット：ＣＯＡＲＳＥ、分光結晶：ＲＸ４、検出器：Ｆ−ＰＣ、分析面積：３０ｍｍφ、ピーク位置（２θ）：１４４．７５ｄｅｇ．、バックグランド（２θ）：１４０．７０ｄｅｇ．および１４６．８５ｄｅｇ．、積算時間：８０秒／ｓａｍｐｌｅ
【０２６１】
５．平版印刷版原版の作成
（実施例１〜７および比較例１〜７）
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を設けて、第１表に示される実施例１〜７および比較例１〜７の平版印刷版原版を得た。なお、画像記録層を設ける前には、後述するように下塗層を設けた。
【０２６２】
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１５ｍｇ／ｍ² であった。
【０２６３】
＜下塗液組成＞
・下記高分子化合物 ０．３ｇ
・メタノール １００ｇ
・水 １ｇ
【０２６４】
【化１４】

【０２６５】
更に、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１．８ｇ／ｍ² になるよう塗布し、乾燥させて感熱層（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。
【０２６６】
＜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） ０．９０ｇ
・メタクリル酸エチル／メタクリル酸イソブチル／メタクリル酸共重合体（モル比３５／３５／３０） ０．１０ｇ
・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（ディフェンサＦ−７８０Ｆ、大日本インキ化学工業社製、固形分３０質量％） ０．００４５ｇ（固形分換算）
・フッ素系界面活性剤（ディフェンサＦ−７８１Ｆ、大日本インキ化学工業社製、固形分１００質量％） ０．０３５ｇ
・メチルエチルケトン １２ｇ
【０２６７】
【化１５】

【０２６８】
６．平版印刷版原版の評価
上記で得られた平版印刷版原版の感度ならびに平版印刷版の耐刷性、バーニング処理後の耐刷性（バーニング耐刷性）、耐汚れ性および水上がりの見やすさを下記の方法で評価した。
【０２６９】
（１）感度
得られた平版印刷版原版をＣｒｅｏ社製のＴｒｅｎｄＳｅｔｔｅｒを用いて、ドラム回転速度１５０ｒｐｍでビーム強度を２〜１３Ｗまで変化させて画像状に描き込み（画像記録）を行った。
その後、下記組成のアルカリ現像液ＡおよびＢのいずれかを仕込んだ富士写真フイルム（株）製ＰＳプロセッサー９４０Ｈを用い、液温を３０℃に保ち、現像時間２０秒で現像した。なお、実施例６にはアルカリ現像液Ａを用い、その他の実施例および比較例にはアルカリ現像液Ｂを用いた。なお、アルカリ現像液ＡはｐＨ１３．２、アルカリ現像液ＢはｐＨ１３．３であった。
現像不良の画像記録層の残膜に起因する汚れや着色がなく良好に現像ができたビーム強度により感度を評価した。ビーム強度が小さいほど感度が高い。結果を第１表に示す。
【０２７０】
＜アルカリ現像液Ａ組成＞
・ＳｉＯ₂ ・Ｋ₂ Ｏ（Ｋ₂ Ｏ／ＳｉＯ₂ ＝１／１（モル比）） ４．０質量％
・クエン酸 ０．５質量％
・ポリエチレングリコールラウリルエーテル（重量平均分子量１，０００） ０．５質量％
・水 ９５．０質量％
【０２７１】
＜アルカリ現像液Ｂ組成＞
・Ｄ−ソルビット ２．５質量％
・水酸化ナトリウム ０．８５質量％
・ポリエチレングリコールラウリルエーテル（重量平均分子量１，０００） ０．５ 質量％
・水 ９６．１５質量％
【０２７２】
（２）耐刷性
得られた平版印刷版原版をＣｒｅｏ社製ＴｒｅｎｄＳｅｔｔｅｒを用いてドラム回転速度１５０ｒｐｍ、ビーム強度１０Ｗで画像状に描き込みを行った。
その後、上記アルカリ現像液ＡおよびＢのいずれかを仕込んだ富士写真フイルム（株）製ＰＳプロセッサー９４０Ｈを用い、液温を３０℃に保ち、現像時間２０秒で現像し、平版印刷版を得た。なお、実施例６にはアルカリ現像液Ａを用い、その他の実施例および比較例にはアルカリ現像液Ｂを用いた。
得られた平版印刷版を、小森コーポレーション社製のリスロン印刷機で、大日本インキ化学工業社製のＤＩＣ−ＧＥＯＳ（Ｎ）墨のインキを用いて印刷し、ベタ画像の濃度が薄くなり始めたと目視で認められた時点の印刷枚数により、耐刷性を評価した。結果を第１表に示す。
【０２７３】
（３）バーニング処理後の耐刷性
耐刷性の評価の場合と同様にして得られた平版印刷版の版面を富士写真フイルム（株）製のバーニング整面液ＢＣ−３で拭いた後、約２４０℃で７分間、バーニング処理を行った。その後、水洗し、富士写真フイルム（株）製ガムＧＵ−７を水で体積を２倍に希釈した液で版面を処理した。
その後、耐刷性の評価の場合と同様に、小森コーポレーション社製のリスロン印刷機で、大日本インキ化学工業社製のＤＩＣ−ＧＥＯＳ（Ｎ）墨のインキを用いて印刷し、ベタ画像の濃度が薄くなり始めたと目視で認められた時点の印刷枚数により、バーニング処理後の耐刷性（バーニング耐刷性）を評価した。結果を第１表に示す。
【０２７４】
（４）耐汚れ性
耐刷性の評価の場合と同様にして得られた平版印刷版を用い、三菱ダイヤ型Ｆ２印刷機（三菱重工業社製）で、ＤＩＣ−ＧＥＯＳ（ｓ）紅のインキを用いて印刷し、１万枚印刷した後におけるブランケットの汚れを目視で評価した。
結果を第１表に示す。ブランケットの汚れの少ないものから多いものまでを○、△、×の３段階で評価した。
【０２７５】
（５）水上がりの見やすさ
耐刷性の評価の場合と同様にして得られた平版印刷版を、小森コーポレーション社製のリスロン印刷機に取り付け、湿し水の供給量を増加させながら版面の非画像部の光り具合を目視で観察し、光り始めたときの湿し水の供給量で検版性（水上がりの見やすさ）を評価した。
結果を第１表に示す。光り始めたときの湿し水の供給量が多いものから少ないものまでを○、△、×の３段階で評価した。
【０２７６】
第１表から明らかなように、本発明の平版印刷版原版（実施例１〜７）は、感度ならびに平版印刷版としたときの耐汚れ性、耐刷性および水上がりの見やすさのいずれにも優れる。
また、ノボラック樹脂を３０質量％以上含有する画像記録層を有する本発明の平版印刷版原版（実施例１〜７）は、上記特性に加え、バーニング耐刷性にも優れる。
更に、露光した後、アルカリ金属ケイ酸塩を実質的に含有せず、非還元糖と塩基とを含有するｐＨ９．０〜１３．５の現像液を用いて現像した場合（実施例１〜５および７）であっても、感度、耐汚れ性、耐刷性および水上がりの見やすさのいずれにも優れる平版印刷版が得られた。
【０２７７】
【表１】

【０２７８】
【発明の効果】
以上に説明したように、本発明の平版印刷版原版は、感度ならびに平版印刷版としたときの耐汚れ性、耐刷性および水上がりの見やすさのいずれにも優れる。
【図面の簡単な説明】
【図１】 本発明に用いられる平版印刷版用支持体の作成における機械的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】 本発明に用いられる平版印刷版用支持体の作成に用いられるフラット型交流電解槽を備える電解粗面化処理装置の一例を示す断面図である。
【図３】 本発明に用いられる平版印刷版用支持体の作成に用いられるフラット型交流電解槽を備える電解粗面化処理装置の他の一例を示す断面図である。
【図４】 本発明に用いられる平版印刷版用支持体の作成に用いられるラジアル型交流電解槽を備える電解粗面化処理装置の一例を示す断面図である。
【図５】 本発明に用いられる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。
【符号の説明】
２、２０ 交流電解槽
４Ａ、４Ｂ、４Ｃ、２６Ａ、２６Ｂ 主極
６Ａ、６Ｂ、１４Ａ、１４Ｂ 搬送ローラ
８Ａ、１６Ａ 導入ローラ
８Ｂ、１６Ｂ 導出ローラ
１０、３４ 補助電解槽
１２、３６ 補助電極
２２ 交流電解槽本体
２２Ａ 開口部
２４ 送りローラ
２８Ａ、２８Ｂ 給液ノズル
３０Ａ 上流側案内ローラ
３０Ｂ 下流側案内ローラ
３２ 溢流槽
３４Ａ 補助電解槽の底面
３５ 上流側案内ローラ
５１ アルミニウム合金板
５２、５４ ローラ状ブラシ
５３ 研磨スラリー液
５５、５６、５７、５８ 支持ローラ
１００、１０２、１０４ 電解粗面化処理装置
ａ 搬送方向
Ｔ 搬送面
Ｔ_ac 電源
Ｔｈ１、Ｔｈ２、Ｔｈ３、Ｔｈ４、Ｔｈ５ サイリスタ
Ｗ アルミニウムウェブ
ｔａ アノード反応時間
ｔｂ カソード反応時間
ｔｃ 電流が０からピークに達するまでの時間
Ｉａ アノードサイクル側のピーク時の電流
Ｉｃ カソードサイクル側のピーク時の電流[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lithographic printing plate precursor.
[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.
For example, in Patent Document 1, the support has a double structure of large and small pits, the large pits are uniform, and the average opening diameter of the small pits is 0.2 μm or more and 0.8 μm or less, and A lithographic printing plate in which the ratio of the small pit depth to the opening diameter is 0.2 or less has been proposed.
However, this lithographic printing plate has a problem that the adhesion between the image recording layer and the support is low and the printing durability is poor.
[0006]
A lithographic printing plate can be generally obtained by exposing and developing a lithographic printing plate precursor. However, the sensitivity of the lithographic printing plate precursor is an important characteristic for appropriate exposure and development.
For the purpose of improving the sensitivity and the like, Patent Document 2 discloses, in a lithographic printing plate having a specific photosensitive layer containing a quinonediazide compound and a triazine compound, a surface area difference, an average roughness, which is an index of the degree of unevenness of the support surface. It has been proposed to define the range and brightness to a specific range.
However, when an image recording layer capable of forming an image by heat is provided on the support used in the planographic printing plate, there is a problem that the sensitivity is poor.
[0007]
Further, during printing using a lithographic printing plate, the operator visually observes the lightness of the non-image area of the printing plate to adjust the balance between the amount of ink and dampening water. Therefore, the ease of observing the lightness, that is, the so-called ease of rising of water is an important characteristic of a lithographic printing plate.
[0008]
Thus, the lithographic printing plate precursor is desired to be excellent in sensitivity and printing durability, stain resistance, and ease of seeing of water when it is used as a lithographic printing plate. However, a lithographic printing plate precursor excellent in any of these characteristics has not been known.
[0009]
Incidentally, as a means for improving the printing durability of a lithographic printing plate, it is known to cure the image recording layer by post-heating treatment after development (hereinafter referred to as “burning treatment”). An image recording layer mainly composed of a novolak resin is known as an image recording layer whose printing durability is greatly improved by the burning process.
However, it has been difficult for a lithographic printing plate precursor having such an image recording layer mainly composed of a novolak resin to balance sensitivity and stain resistance with printing durability.
[0010]
Therefore, it is excellent in sensitivity, printing durability when used as a lithographic printing plate, stain resistance, and ease of seeing water, and is preferably further printed after burning (hereinafter referred to as “burning printing durability”). ) Is also desired.
[0011]
[Patent Document 1]
JP 11-99758 A
[Patent Document 2]
JP-A-8-123014
[0012]
[Problems to be solved by the invention]
The present invention provides a lithographic printing plate precursor that is excellent in sensitivity and printing durability, stain resistance, and ease of seeing of water, and preferably excellent in burning printing durability. With the goal.
[0013]
[Means for Solving the Problems]
  In order to achieve the above object, the present inventorBy electrochemical surface roughening using an aqueous solution containing specific hydrochloric acid,When the surface shape of the support for a lithographic printing plate and the amount of Si atoms attached to the surface are in a specific range, the sensitivity, the printing durability, the stain resistance, and the ease of seeing of water when using a lithographic printing plate are all I found it to be excellent.
  In addition, when the present lithographic printing plate support is used, the present inventor has a balance between sensitivity, stain resistance and printing durability even when an image recording layer mainly composed of a novolac resin is used. As a result, it has been found that the effect of drastically improving the printing durability by the burning treatment can be enjoyed.
  Furthermore, the present inventor, when using the above lithographic printing plate support, has a pH of 9.0 to 13.5, which contains substantially no alkali metal silicate and contains a non-reducing sugar and a base. It has been found that even when developed using a toner, sensitivity and stain resistance can be balanced with printing durability. It has also been found that the use of this developer can prevent the formation of scum and sludge during development, and thus the stability of the developer is greatly improved.
  And this inventor completed this invention based on these knowledge.
[0014]
  That is, the present invention provides the following (1).And (2)I will provide a.
[0015]
  (1) An image is formed by heat on a lithographic printing plate support obtained by subjecting an aluminum plate to an electrochemical surface roughening treatment using an aqueous solution containing at least hydrochloric acid, an anodizing treatment, and an alkali metal silicate treatment. A lithographic printing plate precursor provided with an image recording layer that can be formed,
  In the electrochemical surface roughening treatment using the aqueous solution containing hydrochloric acid, the aluminum plate is subjected to the electrochemical surface roughening treatment while conveying the aluminum plate web in a substantially horizontal direction, using alternating current, and the aluminum The amount of electricity that the plate participates in the anodic reaction is 300 to 600 C / dm ² Done to be
  The lithographic printing plate support isFormed by an electrochemical roughening treatment using an aqueous solution containing hydrochloric acid,The surface has a grain shape with a structure in which large pits with an average opening diameter of 2 to 10 μm and small pits with an average opening diameter of 0.05 to 0.8 μm are superimposed, and the depth of the small pits with respect to the opening diameter The average ratio is 0.2-0.6,
  About the lithographic printing plate support, an actual area S determined 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 ⁵⁰The surface area difference ΔS determined by the following formula (1)⁵⁰Is 20-40%,
  Si atom adhesion amount on the surface of the lithographic printing plate support is 1.0 to 15.0 mg / m²InThe
  The image recording layer contains 30% by mass or more of novolac resin.The lithographic printing plate precursor.
[0016]
ΔS⁵⁰= (S_x ⁵⁰-S₀ ⁵⁰) / S₀ ⁵⁰× 100 (%) (1)
[0018]
  (2)the above(1)After the exposure to the lithographic printing plate precursor described in 1., development is carried out using a developer having a pH of 9.0 to 13.5 substantially containing no alkali metal silicate and containing a non-reducing sugar and a base. A method for producing a lithographic printing plate to obtain a lithographic printing plate.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[Support for lithographic printing plate]
The support for a lithographic printing plate used in the present invention has a grain shape on the surface with a structure in which large pits having an average opening diameter of 2 to 10 μm and small pits having an average opening diameter of 0.05 to 0.8 μm are superimposed. And the average of the ratio of the depth to the opening diameter of the small pit is 0.2 to 0.6,
Real area S obtained by the approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points on the surface of 50 μm □ using an atomic force microscope_x ⁵⁰And geometric measurement area S₀ ⁵⁰The surface area difference ΔS determined by the following formula (1)⁵⁰Is 20-40%,
Surface Si atom adhesion amount is 1.0-15.0 mg / m²It is.
[0020]
ΔS⁵⁰= (S_x ⁵⁰-S₀ ⁵⁰) / S₀ ⁵⁰× 100 (%) (1)
[0021]
<Surface grain shape>
The support for a lithographic printing plate used in the present invention has a grain shape on the surface with a structure in which large pits having an average opening diameter of 2 to 10 μm and small pits having an average opening diameter of 0.05 to 0.8 μm are superimposed. And the average of the ratio of the depth with respect to the opening diameter of the said small pit is 0.2-0.6.
[0022]
Large pits with an average opening diameter of 2 to 10 μm are deeper than the thickness of the fountain solution film. Therefore, if there are large pits on the surface of the support, the fountain solution applied to the plate during printing It becomes easy to confirm the amount visually. That is, the visibility of rising water is excellent. Thereby, it becomes easy to adjust the amount of dampening water supplied to the printing plate. If there is no large pit, the unevenness is reduced, so that the surface of the dampening water becomes smooth and the visibility of the rising water is inferior. The same applies when the average opening diameter of the large pit is too small. If the average opening diameter of the large pits is too large, it becomes difficult to balance sensitivity, printing durability and stain resistance. The average opening diameter of the large pit is 2 μm or more, preferably 4 μm or more, 10 μm or less, and preferably 8 μm or less.
[0023]
Small pits having an average opening diameter of 0.05 to 0.8 μm have a function of holding the image recording layer mainly by an anchor (throwing) effect and imparting printing durability. If the average opening diameter of the small pits is too large, the number of pit boundary portions serving as anchors is reduced, so that the printing durability may be lowered. Small pits having an average opening diameter of 0.05 to 0.8 μm also form a uniform water film and play a role of improving stain resistance. The average opening diameter of the small pits is 0.05 μm or more, preferably 0.1 μm or more, 0.8 μm or less, and preferably 0.6 μm or less.
[0024]
In the present invention, good printing durability and stain resistance are obtained by setting the average ratio of the depth to the opening diameter of the small pits to 0.2 to 0.6. If the average ratio of the depth to the opening diameter of the small pit is too small, the printing durability may be inferior. The average ratio of the depth to the opening diameter of the small pits is 0.2 or more, preferably 0.3 or more, 0.6 or less, and preferably 0.5 or less.
[0025]
In the lithographic printing plate support used in the present invention, the average opening diameter of the large pits on the surface, the average opening diameter of the small pits, and the standard deviation of the opening diameter of the small pits and the average depth measurement method for the opening diameter Is as follows.
[0026]
(1) Average opening diameter of large pits
Using SEM, the surface of the support was photographed at a magnification of 1000 times from directly above, and 50 large pits with a ring around the pit were extracted from the obtained SEM photograph, and the diameter was read to obtain the opening diameter. The average opening diameter is calculated.
[0027]
(2) Average opening diameter of small pits
The surface of the support is photographed at a magnification of 50000 times from directly above using a high-resolution SEM, 50 small pits are extracted from the obtained SEM photograph, the diameter is read and used as the opening diameter, and the average opening diameter is calculated. .
[0028]
(3) Average ratio of depth to small pit opening diameter
The average ratio of the depth to the opening diameter of the small pits was obtained by photographing the fractured surface of the support at a magnification of 50000 times using a high-resolution SEM, and 20 small pits having an opening diameter of 0.8 μm or less in the obtained SEM photograph. The number is extracted, the aperture diameter and depth are read, the ratio is obtained, and the average value is calculated.
[0029]
Further, the lithographic printing plate support used in the present invention has an actual area 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. S_x ⁵⁰And geometric measurement area S₀ ⁵⁰From the above, the surface area difference ΔS determined by the above formula (1)⁵⁰Is 20 to 40%.
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. ΔS⁵⁰In order to increase the thickness, it is effective to provide a large number of small irregularities on the surface. Examples of a method for providing a large number of such small irregularities on the surface include, for example, an electrolytic surface roughening treatment using an electrolytic solution mainly composed of hydrochloric acid, and an electrolytic rough surface using an electrolytic solution mainly composed of high-concentration and high-temperature nitric acid. Preferably, the treatment is performed. ΔS is also obtained by mechanical surface roughening treatment or electrolytic surface roughening treatment using an electrolytic solution mainly composed of nitric acid.⁵⁰Is larger, but to a lesser extent.
In the present invention, ΔS⁵⁰Is 20% or more, preferably 25% or more. ΔS⁵⁰If it is too large, the stain resistance decreases, so it is 40% or less and preferably 35% or less.
[0030]
In the lithographic printing plate support of the present invention, ΔS⁵⁰The method of obtaining is as follows.
[0031]
(1) Surface shape measurement by atomic force microscope
In the present invention, ΔS⁵⁰Is 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 piezoelectric 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 having a resonance frequency of 120 to 150 kHz and a spring constant of 12 to 20 N / m (SI-DF20, manufactured by Seiko Instruments Inc .; NCH-10, manufactured by NANOSENSORS Inc .; or AC-160TS, manufactured by Olympus Corporation) is used in the DFM mode. It is measured by (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, measure 512 × 512 points of 50 μm □ on the surface. The resolution in the XY direction is 1.9 μm, the resolution in the Z direction is 1 nm, and the scan speed is 60 μm / sec.
[0032]
(2) ΔS⁵⁰Calculation
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 difference ΔS⁵⁰Is the actual area S obtained_x ⁵⁰And geometric measurement area S₀ ⁵⁰From the above, it is obtained by the above formula (1).
[0033]
Furthermore, the lithographic printing plate support used in the present invention has a surface Si atom adhesion amount of 1.0 to 15.0 mg / m.²It is.
The amount of Si atom attachment is the mass of Si atoms per unit area measured by a calibration curve method using an X-ray Fluorescence Spectrometer (XRF: X-ray Fluorescence Spectrometer). If the amount of Si atom attached is too small, the sensitivity and stain resistance may be inferior, and if too much, the printing durability may be inferior.
In the present invention, the Si atom adhesion amount is 1.0 mg / m 2.²Or more and 3.0 mg / m²Or more, and 15.0 mg / m²And 10.0 mg / m²It is preferable that: In addition, the said numerical value is a thing after correct | amending the amount of Si atoms to be contained, when an aluminum plate contains Si atoms.
[0034]
As a standard sample for preparing a calibration curve, for example, a sodium silicate aqueous solution containing a known amount of Si atoms is uniformly dropped into an area of 30 mmφ on an aluminum plate and then dried. be able to. Examples of fluorescent X-ray analysis conditions are shown below.
[0035]
X-ray fluorescence analyzer: RIX3000 manufactured by Rigaku Corporation, X-ray tube: Rh, measurement spectrum: Si-Kα, tube voltage: 50 kV, tube current: 50 mA, slit: COARSE, spectral crystal: RX4, detector: F -PC, analysis area: 30 mmφ, peak position (2θ): 144.75 deg. , Background (2θ): 140.70 deg. And 146.85 deg. Integration time: 80 seconds / sample
[0036]
<Aluminum plate (rolled aluminum)>
The aluminum plate used in the present invention is selected from a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic film on which aluminum is laminated or deposited. The trace amount of foreign elements contained in the aluminum plate is one or more selected from those listed in the periodic table of elements, and the content thereof is 0.001 to 1.5% by mass.
Typical examples of the different elements contained in the aluminum alloy include silicon, iron, nickel, manganese, copper, magnesium, chromium, zinc, bismuth, titanium, and vanadium. Usually, a conventionally known material described in Aluminum Handbook 4th Edition (1990, Light Metal Association), for example, JIS A1050 material, JIS A3005 material, JIS A1100 material, JIS A3004 material, internationally registered alloy 3103A, or In order to increase the tensile strength, an alloy in which 5% by mass or less of magnesium is added is used.
[0037]
Further, the aluminum plate used in the present invention may be an aluminum plate obtained by rolling a bullion containing a large amount of impurities recovered by scraping and recycling beverage cans and the like.
In the manufacturing method to be described later, even when a large amount of the trace element is contained, a uniform grain shape (honeycomb pits) can be obtained by electrochemical surface roughening treatment in an aqueous hydrochloric acid solution.
[0038]
In the present invention, it is also possible to use an aluminum plate manufactured by omitting the intermediate annealing treatment and / or soaking treatment from the DC casting method, and an aluminum plate manufactured by omitting the intermediate annealing treatment from the continuous casting method.
[0039]
The thickness of the aluminum plate is preferably 0.05 to 0.8 mm, and more preferably 0.1 to 0.6 mm.
[0040]
In the production of the lithographic printing plate support of the present invention, the aluminum plate is subjected to a surface treatment including an electrochemical roughening treatment in an aqueous solution containing hydrochloric acid to obtain a lithographic printing plate support. However, this surface treatment may further include various treatments. In the various steps used in the present invention, the alloy component of the aluminum plate used in the treatment solution used in the step is eluted, so the treatment solution may contain the alloy component of the aluminum plate. In particular, it is preferable to add the alloy components before the treatment and use the treatment liquid in a steady state.
[0041]
In the present invention, it is possible to roughen the surface by combining the treatments described later. However, it is preferable to perform an alkali etching treatment or a desmut treatment before each electrochemical roughening treatment. It is also preferable to perform an etching process and a desmut process in this order. Moreover, it is preferable to perform an alkali etching process or a desmut process after each electrochemical roughening process, and it is also preferable to perform an alkali etching process and a desmut process in this order. Moreover, the alkali etching process after each electrochemical roughening process can also be abbreviate | omitted.
In the present invention, it is also preferable to perform a mechanical surface roughening treatment before these treatments. Moreover, you may perform each electrochemical surface roughening process twice or more. Moreover, it is also preferable to perform a sealing process, a hydrophilization process, etc. after these.
[0042]
In particular, the surface treatment includes alkali etching treatment, desmut treatment, electrochemical surface roughening treatment in an aqueous hydrochloric acid solution, alkali etching treatment and / or desmut treatment, anodizing treatment, and hydrophilization treatment in this order. This is one of the preferred embodiments of the present invention.
In this case, it is one of the preferable embodiments of the present invention that the alkali metal silicate is used for the hydrophilic treatment. Further, in this case, it is one of preferred embodiments of the present invention that the surface treatment includes a mechanical surface roughening treatment before the first alkali etching treatment.
[0043]
Hereinafter, each of the mechanical surface roughening treatment, alkali etching treatment, desmutting treatment, electrochemical surface roughening treatment, anodizing treatment, sealing treatment and hydrophilization treatment will be described in detail.
[0044]
<Mechanical roughening>
In the present invention, the mechanical surface roughening treatment is preferably performed before the electrochemical surface roughening treatment. The surface area of the aluminum plate is increased by the mechanical roughening treatment.
First, prior to brush graining an aluminum plate, a degreasing treatment for removing rolling oil on the surface, for example, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution, or the like is performed as desired. However, when the adhesion of rolling oil is small, the degreasing treatment can be omitted.
Subsequently, brush graining is performed using one or at least two brushes having different bristle diameters while supplying the polishing slurry liquid to the surface of the aluminum plate.
[0045]
The mechanical surface roughening treatment is described in detail in JP-A-6-135175 and JP-B-50-40047. The brush used first in the brush graining is called a first brush, and the brush used finally is called a second brush. In FIG. 1, 51 is an aluminum plate, 52 and 54 are roller brushes, 53 is a polishing slurry, and 55, 56, 57 and 58 are support rollers. At the time of graining, as shown in FIG. 1, roller brushes 52 and 54 and two support rollers 55, 56 and 57, 58 are arranged with an aluminum plate 51 interposed therebetween. The two support rollers 55, 56 and 57, 58 are arranged such that the shortest distance between the outer surfaces of the two support rollers 55, 56 and 57, 58 is smaller than the outer diameter of each of the roller brushes 52 and 54, and the aluminum plate 51 is added by the roller brushes 52 and 54. The aluminum plate is conveyed at a constant speed while being pressed and pushed between the two support rollers 55, 56 and 57, 58, and the polishing slurry liquid 53 is supplied onto the aluminum plate so that the roller brush is It is preferable to polish the surface by rotating.
[0046]
The brush used in the present invention has a roller-like base portion in which a brush material such as nylon, polypropylene, animal hair, steel wire or the like is implanted with uniform hair length and flocking distribution, and has a small hole in the roller-like base portion. Those in which hair bundles are implanted, channel roller type, etc. are preferably used. Among them, a preferable material is nylon, and a preferable hair length after flocking is 10 to 200 mm. The hair density when planted on the brush roller is 1cm.²The number is preferably 30 to 1000, more preferably 50 to 300.
A preferable bristle diameter of the brush is 0.24 to 0.83 mm, and more preferably 0.295 to 0.72 mm. The cross-sectional shape of the hair is preferably a circle. When the bristle diameter is smaller than 0.24 mm, the stain resistance at the shadow portion is deteriorated, and when it is larger than 0.83 mm, the stain resistance on the blanket may be deteriorated. Nylon is preferred as the material of the hair, and nylon 6, nylon 6,6, nylon 6,10, etc. are used, but tensile strength, abrasion resistance, dimensional stability due to water absorption, bending strength, heat resistance, recoverability, etc. Nylon 6 · 10 is most preferable.
[0047]
The number of brushes is preferably 1 or more and 10 or less, and more preferably 1 or more and 6 or less. As described in JP-A-6-135175, brush rollers having different bristle diameters may be combined.
Next, the rotation of the brush roller is preferably selected arbitrarily from 100 rpm to 500 rpm. The support roller has a rubber or metal surface and is kept straight. The brush roller is preferably rotated in the forward direction in the aluminum plate conveying direction as shown in FIG. 1, but if there are a large number of brush rollers, some of the brush rollers may be reversed. The pushing amount of the brush is preferably managed by the load of the rotary drive motor of the brush, and is preferably managed so that the power consumption of the rotary drive motor is 1.0 to 15 kW, and further 2 to 10 kW.
[0048]
In the present invention, it is preferable to obtain a support having all of hydrophilicity, water retention and adhesion by roughening with the thick brush and then treating with a thin brush. In this case, the shadow portion is not crushed when the amount of dampening water is small, so that the water width is wide, scumming is less likely to occur, and adhesion deterioration with the image recording layer does not occur.
The polishing slurry liquid used in the present invention is an abrasive having an average particle diameter of 1 to 50 μm (preferably 20 to 45 μm) such as silica sand, aluminum hydroxide, alumina powder, volcanic ash, pumice, carborundum, and gold sand. Those dispersed in water in a range of 0.05 to 1.3 are preferable. The average particle diameter refers to a particle diameter at which the cumulative ratio is 50% when the cumulative frequency of the ratio of the particles of each diameter is taken with respect to the volume of all abrasives contained in the slurry liquid.
The center line average roughness (R_a) Is preferably processed so as to be 0.3 to 1.0 μm.
Of course, a method of spraying the slurry liquid, a method using a wire brush, a method of transferring the surface shape of the uneven roll to the aluminum plate, or the like may be used. Other methods are described in JP-A-55-074898, JP-A-61-162351, JP-A-63-104889, and the like.
[0049]
After brush graining the aluminum plate in this way, it is preferable to chemically etch the surface of the aluminum plate. This chemical etching process has the action of removing abrasives, aluminum debris, and the like that have digged into the surface of the aluminum sheet that has been subjected to brush graining, and the subsequent electrochemical roughening is made more uniform. Moreover, it can be achieved effectively.
[0050]
<Chemical etching treatment in alkaline aqueous solution>
The alkali etching treatment is performed by bringing the aluminum plate into contact with an alkaline solution. The alkali etching treatment is performed for the purpose of removing rolling oil, dirt, and natural oxide film on the surface of the aluminum plate (rolled aluminum) when mechanical roughening treatment is not performed. When the surface treatment is performed, it is performed for the purpose of obtaining a surface having smooth undulations by dissolving the uneven edge portions generated by the mechanical surface roughening treatment.
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.
[0051]
Details of such a chemical etching method are described in US Pat. No. 3,834,398. More specifically, it is a method of dipping in a solution capable of dissolving aluminum, more specifically, an alkaline aqueous solution.
Examples of the alkali include sodium hydroxide, potassium hydroxide, tribasic sodium phosphate, tribasic potassium phosphate, sodium aluminate, sodium metasilicate, sodium carbonate and the like. When an aqueous base solution is used, the etching rate is fast.
[0052]
The chemical etching is preferably performed using an aqueous solution of 0.05 to 40% by mass (mass%) of these alkalis at a liquid temperature of 40 to 100 ° C. for 5 to 300 seconds. The concentration of the alkaline aqueous solution is preferably 1 to 30% by mass, and the alloy component contained in the aluminum alloy as well as aluminum may be 0 to 10% by mass. As the alkaline aqueous solution, an aqueous solution mainly composed of caustic soda is particularly preferable. The liquid temperature is preferably from room temperature to 95 ° C. and treated for 1 to 120 seconds.
[0053]
After the etching process is completed, in order not to bring the treatment liquid into the next process, it is preferable to perform liquid removal by a nip roller and water washing by spraying.
As the chemical etching amount of the aluminum plate, the dissolution amount of the aluminum plate on one side is 0.001 to 30 g / m.²Is more preferable, and more preferably 1 to 15 g / m.²And particularly preferably 3 to 12 g / m.²It is.
[0054]
<Acid etching process>
The acidic etching treatment is a treatment for chemically etching the aluminum plate in an acidic aqueous solution, and is preferably performed after the electrochemical surface roughening treatment. Moreover, when performing the said alkali etching process before and / or after the said electrochemical roughening process, it is also preferable to perform an acidic etching process after an alkali etching process.
When the above-mentioned alkaline etching treatment is performed on the aluminum plate and then the above-mentioned acidic etching treatment is performed, the intermetallic compound containing silica or simple substance Si on the surface of the aluminum plate can be removed, and the anodic oxidation generated in the subsequent anodizing treatment Film defects can be eliminated. As a result, it is possible to prevent the trouble that the dot-like ink adheres to the non-image portion called “dirty stain” during printing.
[0055]
Examples of the acidic aqueous solution used for the acidic etching treatment include an aqueous solution containing phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixed acid of two or more of these. Of these, a sulfuric acid aqueous solution is preferable. The concentration of the acidic aqueous solution is preferably 50 to 500 g / L. The acidic aqueous solution may contain an alloy component contained in the aluminum plate as well as aluminum.
[0056]
The acidic etching treatment is preferably performed by treating the liquid temperature at 60 to 90 ° C., preferably 70 to 80 ° C., for 1 to 10 seconds. The dissolution amount of the aluminum plate at this time is 0.001 to 0.2 g / m.²Is preferred. The acid concentration, for example, the sulfuric acid concentration and the aluminum ion concentration are preferably selected from a range that does not crystallize at room temperature. A preferable aluminum ion concentration is 0.1 to 50 g / L, and particularly preferably 5 to 15 g / L.
In addition, after the acidic etching process is completed, in order not to take out the processing liquid to the next process, it is preferable to perform liquid drainage by a nip roller and water washing by spraying.
[0057]
<Desmutting treatment in acidic aqueous solution (first desmutting treatment)>
When chemical etching is performed using an alkaline aqueous solution, smut is generally generated on the surface of aluminum. In this case, phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or two or more acids thereof are included. Desmut with mixed acid. The concentration of the acidic aqueous solution is preferably 0.5 to 60% by mass. Further, in the acidic aqueous solution, 0 to 5% by mass of the alloy component contained in the aluminum alloy as well as aluminum may be dissolved.
Further, as the desmutting treatment liquid, it is particularly preferable to use the waste liquid generated by the electrochemical surface roughening treatment or the waste liquid generated by the anodizing treatment.
[0058]
Liquid temperature is implemented at normal temperature to 95 degreeC, and 30-70 degreeC is especially preferable. The treatment time is preferably 1 to 120 seconds, particularly preferably 1 to 5 seconds. After the desmutting process is completed, it is preferable to perform liquid removal with a nip roller and water washing with a spray so as not to bring the processing liquid into the next process. The liquid removal by the nip roller and the water washing by the spray can be omitted when the desmut treatment liquid uses the same kind of liquid as the liquid used in the next step or a liquid having the same composition.
In addition, when an auxiliary anode tank is used in an electrochemical surface roughening process to prevent electrode dissolution and control the roughened shape, an alternating current flows through the aluminum plate to the electrochemical plate. In the case of bringing it in front of the tank for performing the general surface roughening treatment, the desmutting step in the acidic aqueous solution prior to the electrochemical surface roughening treatment can be omitted.
[0059]
<Electrochemical roughening treatment>
The electrochemical surface roughening treatment in the present invention is characterized by an electrochemical surface roughening treatment in an aqueous solution containing hydrochloric acid (hereinafter also referred to as “aqueous solution mainly containing hydrochloric acid”).
By performing electrochemical surface roughening treatment and anodizing treatment under these specific conditions, and if necessary, hydrophilization treatment, mechanical surface roughening treatment, and each surface treatment described in this specification, Aim can be achieved.
Further, the electrochemical surface roughening treatment may be performed a plurality of times, or before or after the electrochemical surface roughening treatment in the aqueous solution mainly containing hydrochloric acid, in the aqueous solution mainly containing nitric acid. An electrochemical surface roughening treatment may be performed.
Hereinafter, the electrochemical roughening treatment will be described.
[0060]
(1) Aqueous solution mainly composed of hydrochloric acid
  As the aqueous solution mainly composed of hydrochloric acid in the present invention, those used for electrochemical surface roughening treatment using ordinary direct current or alternating current can be used, and 1-30 g / L hydrochloric acid aqueous solution is added with aluminum nitrate, sodium nitrate. One or more of hydrochloric acid or nitric acid compounds having nitrate ions such as ammonium nitrate, and hydrochloric acid ions such as aluminum chloride, sodium chloride and ammonium chloride can be added to 1 g / L to saturation. Moreover, the compound which forms a complex with copper can also be added in the ratio of 1-200 g / L. In an aqueous solution mainly composed of hydrochloric acid, a metal contained in an aluminum alloy such as iron, copper, manganese, nickel, titanium, magnesium, or silica may be dissolved. Hypochlorous acid or hydrogen peroxide may be added at 1 to 100 g / L.
  An aqueous hydrochloric acid solution is prepared by adding an aluminum salt (aluminum chloride, AlCl) to an aqueous solution containing a liquid temperature of 15 to 50 ° C. and hydrochloric acid of 1 to 30 g / L._Three・ 6H₂Particularly preferred is an aqueous solution in which O) is added at a rate of 10 to 300 g / L to make the aluminum ion concentration 1 to 30 g / L. When an electrochemical surface roughening treatment is performed using such an aqueous hydrochloric acid solution, the surface shape of the surface roughening treatment becomes uniform, and a low-purity aluminum rolled plate (an aluminum plate or an alloy component containing a large amount of alloy components is removed). Even when an unprepared aluminum plate is used, uneven processing due to the roughening treatment does not occur, and excellent printing durability and printing performance (stain resistance) can be achieved when a planographic printing plate is used.
  Here, the hydrochloric acid aqueous solution preferably contains 5 to 20 g / L of hydrochloric acid, and particularly preferably contains 8 to 15 g / L.
  The aluminum chloride hexahydrate to be added is preferably 10 to 300 g / L, more preferably 50 to 200 g / L, and particularly preferably 80 to 150 g / L.
  The aluminum ion concentration of the aqueous hydrochloric acid solution to which aluminum chloride hexahydrate is added is preferably 1 to 30 g / L, more preferably 5 to 20 g / L, and particularly preferably 8 to 15 g / L. preferable.
  As an additive, an apparatus, a power source, a current density, a flow rate, and a temperature in an aqueous solution mainly containing hydrochloric acid, those used for known electrochemical surface roughening can be used. The power source used for electrochemical roughening isCurrentUsedTheThe amount of electricity that the aluminum plate participates in the anodic reaction by electrochemical surface roughening in an aqueous solution mainly composed of hydrochloric acid is determined when the electrochemical surface roughening treatment is completed.300~600C / dm²You can choose from a range ofRu.
[0061]
(2) Aqueous solution mainly composed of nitric acid
The aqueous solution mainly composed of nitric acid as used in the present invention can be one used for electrochemical surface roughening treatment using ordinary direct current or alternating current, and 1-100 g / L nitric acid aqueous solution is mixed with aluminum nitrate, sodium nitrate. One or more of hydrochloric acid or nitric acid compounds having nitrate ions such as ammonium nitrate, and hydrochloric acid ions such as aluminum chloride, sodium chloride and ammonium chloride can be added to 1 g / L to saturation. Moreover, the compound which forms a complex with copper can also be added in the ratio of 1-200 g / L. In an aqueous solution mainly composed of nitric acid, a metal contained in an aluminum alloy such as iron, copper, manganese, nickel, titanium, magnesium, or silica may be dissolved. Hypochlorous acid or hydrogen peroxide may be added at 1 to 100 g / L.
An aqueous solution in which aluminum ions (aluminum nitrate) are added to an aqueous solution containing a liquid temperature of 15 to 90 ° C. and nitric acid in an amount of 5 to 15 g / L to make aluminum ions 3 to 50 g / L is particularly preferable. As the additive, apparatus, power source, current density, flow rate, and temperature in an aqueous solution mainly composed of nitric acid, those used for known electrochemical surface roughening can be used. AC or DC is used as the power source used for electrochemical roughening, but AC is particularly preferable. The amount of electricity that the aluminum plate participates in the anodic reaction by electrochemical surface roughening in an aqueous solution mainly containing nitric acid is 10 to 1000 C / dm at the time when the electrochemical surface roughening treatment is completed.²Can be selected from the range of 100 to 500 C / dm²Is preferred, 150-300 C / dm²Is particularly preferred.
[0062]
(3) Electrochemical roughening treatment
  The electrochemical surface roughening treatment refers to an electrochemical surface roughening treatment in an acidic aqueous solution by applying direct current or alternating current between an aluminum plate and an electrode facing the aluminum plate. In the present invention,In the electrochemical surface roughening treatment in an aqueous solution mainly containing hydrochloric acid, alternating current is used. In the electrochemical surface roughening treatment in an aqueous solution mainly containing nitric acid,Although alternating current is particularly preferred, the alternating current may be any of single phase, two phase, three phase, and the like. Also, a current in which alternating current and direct current are superimposed can be used.
  Any known electrolytic treatment tank can be used, and the electrolytic tank used for electrochemical surface roughening can be an electrolytic tank used for a known surface treatment such as a vertical type, a flat type, or a radial type.However, in the electrochemical surface roughening treatment in an aqueous solution mainly composed of hydrochloric acid, a flat electrolytic cell is used.. A plurality of electrolytic treatment tanks may be provided. In addition, electrochemical surface roughening is repeatedly performed with etching treatment in acid or alkali aqueous solution, desmutting treatment in acidic aqueous solution, cathode electrolytic treatment of aluminum plate in acid or neutral salt aqueous solution, etc. May be.
[0063]
a) Power supply method to aluminum plate
As a power supply method to the aluminum plate, a direct power supply method using a conductor roll or a liquid power supply method (indirect power supply method) not using a conductor roll can be used. The electrolyte passing through the electrolytic cell may be parallel to the progress of the aluminum web or may be a counter. One or more AC power sources can be connected to one electrolytic cell. When the indirect power feeding method is used, the method using an auxiliary anode described in Japanese Patent Publication No. 6-37716 and Japanese Patent Publication No. 5-42520 discloses the amount of electricity applied to the aluminum plate at the time of anode and the electricity at the time of cathode. It is preferable to adjust the ratio of the amounts. The current flowing through the auxiliary anode is particularly preferably controlled using a rectifier such as a thyristor, a diode, or a GTO. If the system described in Japanese Patent Publication No. 6-37716 is used, the amount of electricity at the time of anode of alternating current and the cathode on the surface of the aluminum plate facing the carbon electrode of the main electrode where electrochemical roughening reaction is performed The amount of electricity (current value) at the time can be easily controlled. In addition, the influence of transformer magnetic bias is small in terms of production of the power supply device, which is very advantageous in terms of cost.
[0064]
The current value control method for electrochemical surface roughening using sine waves is used in combination with a transformer, variable induction voltage regulator, etc., and the current value used for electrolysis is variable induction voltage adjustment. Feedback to the vessel. At that time, as a method of controlling the current value, a method of controlling the phase with a thyristor can be used in combination as described in JP-A-55-25812.
[0065]
In electrochemical surface roughening, current deviation tends to occur if the distance between the aluminum plate and the electrode and the liquid flow rate are not constant, resulting in uneven processing of the aluminum surface, which is not suitable as a support for a lithographic printing plate. Will be manufactured. In order to solve the problem, a liquid supply nozzle provided with a liquid pool chamber inside and provided with a slit for discharging liquid of 1 to 5 mm in the width direction of the aluminum web can be used. In addition, it is particularly preferable to provide a plurality of liquid pool chambers, and to provide a valve and a flow meter in a pipe connected to each liquid pool chamber to adjust the amount of liquid blown out from each slit.
The distance between the aluminum web and the electrode is preferably 5 to 100 mm, particularly preferably 8 to 15 mm. In order to keep this distance constant, there is a method described in Japanese Patent Publication No. 61-30036, which uses a static pressure on a surface on which a running web can slide and makes the web run while being pressed against the sliding surface. Used. Alternatively, as described in JP-A-8-300843, a method of keeping the distance between the electrode and the aluminum plate constant by using a roller having a large diameter can also be used.
[0066]
When using the direct feeding method, a conductor roll as described in Japanese Patent Laid-Open No. 58-177441 is used, and an electrochemical surface roughening is performed with an apparatus described in Japanese Patent Laid-Open No. 56-123400. It is preferable to process. The conductor roll can be provided on the upper surface or the lower surface of the aluminum web, but it is particularly preferable that the conductor roll is provided on the upper surface of the aluminum plate and pressed against the aluminum plate by a nip device. The length of the aluminum plate in contact with the conductor roll is preferably 1 to 300 mm with respect to the aluminum traveling direction. The pass roll facing the conductor roll with the aluminum plate interposed is preferably a rubber roll. The pressing pressure and the hardness of the rubber roll are arbitrarily set under the condition that no arc spot is generated. By installing the conductor roll on the upper surface of the aluminum plate, the conductor roll can be easily replaced and inspected. It is preferable to use a method of energizing the end of the conductor roll while sliding the power supply brush on the rotating body.
It is preferable to always cool the conductor roll pressed against the aluminum plate with an electrolytic solution having the same composition and the same temperature as the electrolytic solution used for electrochemical roughening in order to prevent generation of an arc spot. If foreign matter enters the electrolyte, an arc spot is likely to be caused. Therefore, it is preferable to wrap a filter used for cooling the spray or to put a fine mesh filter on the upstream side of the spray pipe.
[0067]
b) Electrochemical roughening using alternating current
A sine wave, a rectangular wave, a trapezoidal wave, a triangular wave, or the like can be used as the AC power supply waveform used for electrochemical roughening, but a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal wave is particularly preferable. The frequency is preferably 0.1 to 500 Hz, more preferably 40 to 120 Hz, and particularly preferably 45 to 65 Hz.
When a trapezoidal wave is used, the time tp until the current reaches a peak from 0 is preferably 0.1 to 2 msec, particularly preferably 0.2 to 1.5 msec. Due to the influence of the impedance of the power supply circuit, if tp is less than 0.1, a large power supply voltage is required when the current waveform rises, and the equipment cost of the power supply increases. When it is longer than 2 msec, it is easily affected by a trace component in the electrolytic solution, and uniform surface roughening is difficult to be performed. The ratio of one cycle of alternating current used for electrochemical roughening to the anode reaction time ta of the aluminum plate in the alternating cycle T (referred to as “duty” in the present invention) ta / T is 0.33. ˜0.66 is preferable, 0.45 to 0.55 is more preferable, and 0.5 is particularly preferable.
On the surface of the aluminum plate, an oxide film mainly composed of aluminum hydroxide may be formed during the cathode reaction, and the oxide film may be dissolved or broken. When the oxide film dissolves or breaks, the portion where the dissolution or breakage occurs becomes the starting point of the pitting reaction during the anode reaction of the next aluminum plate. Therefore, the selection of the AC duty is particularly important in that uniform electrolytic surface roughening is performed.
[0068]
The amount of electricity applied to the aluminum plate facing the main electrode is the amount of electricity Q when the aluminum plate reacts with the cathode._cAnd quantity of electricity Q during anode reaction_aRatio Q_c/ Q_aIs in the range of 0.9 to 1.0, preferably 0.92 to 0.98, and particularly preferably 0.94 to 0.96. Q_c/ Q_aWithin this range, uneven processing due to the surface roughening treatment does not occur, and it is possible to achieve both printing durability and printing performance (stain resistance) when using a lithographic printing plate. Q_c/ Q_aIf it exceeds 1.0, the electrode may dissolve. The control of the electric quantity ratio can be performed by controlling the voltage generated by the power source.
When the electrolytic surface roughening treatment is performed using an AC electrolytic cell having an auxiliary electrode for diverting the anode current of the main electrode, it is described in JP-A-60-43500 and JP-A-1-52098. By controlling the current value of the anode current that is shunted to the auxiliary electrode, Q_c/ Q_aCan be controlled.
The current density is the peak value of the trapezoidal wave, and the current I_a, Cathode cycle side I_cBoth 10-200A / dm²Is preferred. I_a/ I_cIs preferably in the range of 0.5-3.
As the electrolytic cell used for electrochemical surface roughening using alternating current in the present invention, known electrolytic cells such as a vertical type, a flat type, and a radial type can be used, but JP-A-5-195300. A radial type electrolytic cell or a flat type as described in the publication is particularly preferred. The electrode is particularly preferably carbon as a main electrode and ferrite as an auxiliary anode.
Further, an electrolytic surface roughening apparatus in which a plurality of AC electrolytic cells are arranged in series can also be suitably used.
[0069]
An electrolytic cell having an auxiliary anode can be installed before or after an electrolytic cell having a main electrode. In particular, an electrolytic cell having an auxiliary electrode used in an electrochemical surface roughening step mainly composed of hydrochloric acid is mainly used. Bringing it in front of the electrolytic cell having the electrode is preferable in terms of reducing the occurrence of processing unevenness.
Also, if the distance between the inlet (liquid level) of the electrolytic cell having the auxiliary electrode and the inlet (liquid level) of the electrolytic cell having the main electrode is too long, the intermetallic compound in the aluminum plate is formed by the chemical dissolution reaction of hydrochloric acid. It melts to form deep holes, and the image recording layer at that portion is thickly coated, resulting in uneven printing. Therefore, it is preferable that the time from the inlet (liquid level) of the electrolytic cell in which the aluminum plate has the auxiliary electrode to the inlet (liquid level) of the electrolytic cell having the main electrode is 3 seconds or less.
[0070]
In the electrolytic surface-roughening treatment, in one or more AC electrolytic cells, an aluminum plate between the main electrodes connected to power terminals having different polarities in one electrolytic cell, and these main electrodes, It is preferable to provide one or more rest periods during which no alternating current flows during this period, and to set the length of the rest period to 0.001 to 0.6 seconds, since honeycomb pits are uniformly formed on the entire surface of the aluminum plate. More preferably, it is 0.005-0.55 second, More preferably, it is 0.01-0.5 second.
When two or more alternating current electrolytic cells arranged in series are used, the time during which alternating current does not flow through the aluminum plate between one alternating current electrolytic cell and another alternating current electrolytic layer is 0.001 to 20 seconds. Is preferred. More preferably, it is 0.1-15 seconds, More preferably, it is 1-12 seconds.
[0071]
In FIG. 2, the cross-sectional schematic diagram of an example of the electrolytic surface-roughening processing apparatus provided with the flat type AC electrolytic cell suitably used for this invention is shown. In FIG. 2, 2 is an AC electrolytic cell, 4A, 4B and 4C are main poles, 6A and 6B are transport rollers, 8A is an introduction roller, 8B is a discharge roller, and 100 is an electrolytic surface-roughening treatment device. The electrolytic surface roughening apparatus 100 applies an electrolytic surface roughening treatment by applying a three-phase alternating current (hereinafter also referred to as “three-phase alternating current”) while conveying the aluminum web W in a substantially horizontal direction. It is a chemical processing apparatus.
[0072]
The electrolytic surface-roughening treatment apparatus 100 includes a shallow box-shaped AC electrolytic cell 2 that extends along the conveyance direction a of the aluminum web W and has an open upper surface, and a conveyance direction a near the bottom surface of the AC electrolytic cell 2. The three main plate electrodes 4A, 4B and 4C arranged in parallel to the conveyance surface T which is the conveyance path of the aluminum web W, and upstream of the conveyance direction a in the AC electrolytic cell 2 Side (hereinafter simply referred to as “upstream side”) and in the vicinity of the end of the downstream side (hereinafter simply referred to as “downstream side”) with respect to the conveyance direction a, and the aluminum web W inside the AC electrolytic cell 2. Conveying rollers 6 </ b> A and 6 </ b> B, an upstream roller above the AC electrolytic cell 2, an introduction roller 8 </ b> A for introducing the aluminum web W into the AC electrolytic cell 2, and a downstream side above the AC electrolytic cell 2. Located in And a derivation roller 8B to derive the aluminum web W that has passed through the internal AC electrolytic cell 2 to the external AC electrolytic cell 2. The above-described acidic aqueous solution is stored in the AC electrolytic cell 2.
The main poles 4A, 4B and 4C each have an AC power supply T for generating three-phase AC._acAre connected to the U terminal, V terminal and W terminal. Therefore, the alternating current applied to the main poles 4A, 4B, and 4C is shifted in phase by 120 °.
[0073]
The operation of the electrolytic surface roughening treatment apparatus 100 will be described below.
The aluminum web W is introduced into the AC electrolytic cell 2 by the introduction roller 8A, and is conveyed at a constant speed along the conveyance direction a by the conveyance rollers 6A and 6B.
Inside the AC electrolytic cell 2, the aluminum web W moves in parallel to the main poles 4A, 4B, and 4C, and AC is applied from the main poles 4A, 4B, and 4C. Thereby, in the aluminum web W, the anode reaction and the cathode reaction occur alternately, and when the anode reaction occurs, honeycomb pits are mainly generated, and when the cathode reaction occurs, an aluminum hydroxide film is mainly formed. The surface is roughened.
Since the alternating current applied to the main poles 4A, 4B and 4C is shifted in phase by 120 ° as described above, the main pole 4B has a phase delayed by 120 ° from the phase (U phase) of the main pole 4A. The anode reaction and the cathode reaction are repeated in (V phase), and the anode reaction and the cathode reaction are repeated in the main electrode 4C at a phase (W phase) delayed by 120 ° from the main electrode 4B.
Therefore, in the aluminum web W, the anode reaction and the cathode reaction are repeated three times more frequently than when a single-phase alternating waveform current having the same frequency is applied. Even when the surface roughening process is performed, chatter marks that are stripes in the width direction are less likely to occur.
[0074]
In FIG. 3, the cross-sectional schematic diagram of another example of the electrolytic surface-roughening processing apparatus provided with the flat type | formula electrolytic cell suitably used for this invention is shown. 3, the same reference numerals as those in FIG. 2 denote the same elements as those shown in FIG. 2, 10 is an auxiliary electrolytic cell, 12 is an auxiliary electrode, 14A and 14B are transport rollers, 16A is an introduction roller, Reference numeral 16B denotes a lead-out roller, reference numeral 102 denotes an electrolytic surface roughening treatment apparatus, and reference numerals Th1, Th2, and Th3 denote thyristors.
The electrolytic surface roughening treatment apparatus 102 is an electrolytic surface roughening treatment apparatus in which an auxiliary electrolytic cell 10 is disposed in front of the AC electrolytic cell 2 provided in the electrolytic surface roughening treatment apparatus 100 described above.
The auxiliary electrolytic cell 10 has a box shape with an open upper surface, and a plate-like auxiliary electrode 12 is provided in the vicinity of the bottom surface in parallel to the transport surface T of the aluminum web W.
Conveying rollers 14 </ b> A and 14 </ b> B that convey the aluminum web W above the auxiliary electrode 12 are disposed in the vicinity of the upstream side wall surface and the vicinity of the downstream side wall surface of the auxiliary electrolytic cell 10. An introduction roller 16A for introducing the aluminum web W into the auxiliary electrolytic cell 10 is provided on the upstream side above the auxiliary electrolytic cell 10, and the auxiliary electrolytic cell 10 is provided on the downstream side above the auxiliary electrolytic cell 10. A lead-out roller 16B that guides the aluminum web W that has passed through the inside to the outside is provided. The acidic aqueous solution described above is stored in the auxiliary electrolytic cell 10.
[0075]
AC power supply T_acThe U-phase, V-phase and W-phase are respectively connected to the auxiliary electrode 12, and thyristors Th1, Th2 and Th3 are interposed between the U-phase, V-phase and W-phase and the auxiliary electrode 12, respectively. Yes. Thyristors Th1, Th2 and Th3 are all connected to AC power supply T_acTo the auxiliary electrode 12 so that a current flows. Therefore, when any of the thyristors Th1, Th2, and Th3 is ignited, an anode current flows through the auxiliary electrode 12. Therefore, by controlling the phase of the thyristors Th1, Th2, and Th3, the current of the anode current flowing through the auxiliary electrode 12 is controlled. The value can be controlled and thus Q_c/ Q_aThe value of can also be controlled.
[0076]
In FIG. 4, the cross-sectional schematic diagram of an example of the electrolytic surface-roughening processing apparatus provided with the radial type | formula alternating current electrolytic cell suitably used for this invention is shown. In FIG. 4, 20 is an AC electrolytic cell, 26A and 26B are main electrodes, 34 is an auxiliary electrolytic cell, 35 is an upstream guide roller, 36 is an auxiliary electrode, 22 is an AC electrolytic cell body, 22A is an opening, and 24 is an opening. Feed rollers 28A and 28B are liquid supply nozzles, 30A is an upstream guide roller, 30B is a downstream guide roller, 32 is an overflow tank, 34A is a bottom surface of the auxiliary electrolytic tank, 104 is an electrolytic surface roughening treatment device, Th4 And Th5 are thyristors, respectively.
The electrolytic surface-roughening treatment apparatus 104 is disposed in an alternating-current electrolytic cell 20 including an alternating-current electrolytic cell main body 22 in which an acidic aqueous solution is stored, and accommodated in the alternating-current electrolytic cell main body 22 so as to be rotatable around an axis extending in a horizontal direction. And a feed roller 24 for feeding the aluminum web W in the transport direction a from the left to the right in FIG. The acidic aqueous solution described above is stored in the AC electrolytic cell main body 22.
The inner wall surface of the AC electrolytic cell main body 22 is formed in a substantially cylindrical shape so as to surround the feed roller 24, and semicylindrical main electrodes 26 </ b> A and 26 </ b> B are provided on the inner wall surface with the feed roller 24 interposed therebetween. It has been. The main electrodes 26A and 26B are divided into a plurality of small electrodes, and an insulating spacer is interposed between the small electrodes. The small electrode can be formed using, for example, graphite or metal, and the spacer can be formed using, for example, a vinyl chloride resin. The thickness of the spacer is preferably 1 to 10 mm. Although shown in FIG. 4 in a simplified manner, in each of the main poles 26A and 26B, each of the small electrodes divided by the spacers is an AC power source T._acIt is connected to the.
[0077]
In the upper part of the AC electrolytic cell 20, an opening 22A for introducing the aluminum web W into the AC electrolytic cell main body 22 and leading it out is formed. In the vicinity of the opening 22 </ b> A in the AC electrolytic cell main body 22, a liquid supply nozzle 28 </ b> A for replenishing the AC electrolytic cell main body 22 with an acidic aqueous solution is provided. A liquid supply nozzle 28B is also provided separately.
In the vicinity of the opening 22 </ b> A above the AC electrolytic cell 20, a group of upstream guide rollers 30 </ b> A for guiding the aluminum web W into the AC electrolytic cell main body 22 and electrolytic surface roughening treatment in the AC electrolytic cell main body 22 were performed. A group of downstream guide rollers 30B for guiding the aluminum web W to the outside is disposed.
[0078]
In the AC electrolytic cell 20, an overflow tank 32 is provided adjacent to the downstream side of the AC electrolytic cell main body 22. In the overflow tank 32, the above-described acidic aqueous solution is stored. The overflow tank 32 temporarily stores the acidic aqueous solution overflowing from the AC electrolytic cell main body 22 and has a function of keeping the level of the acidic aqueous solution in the AC electrolytic cell main body 22 constant.
[0079]
An auxiliary electrolytic cell 34 is provided in the upstream (upstream) of the AC electrolytic cell main body 22. The auxiliary electrolytic cell 34 is shallower than the AC electrolytic cell main body 22, and the bottom surface 34A is formed in a planar shape. A plurality of cylindrical auxiliary electrodes 36 are provided on the bottom surface 34A. The acidic aqueous solution described above is stored in the auxiliary electrolytic cell 34.
The auxiliary electrode 36 is preferably made of a highly corrosion-resistant metal such as platinum, ferrite or the like. The auxiliary electrode 36 may be plate-shaped.
The auxiliary electrode 36 is an AC power source T_acIs connected in parallel to the main pole 26A on the side to which the main pole 26A is connected. In the middle, the thyristor Th4 is connected to the AC power source T_acAre connected so that a current flows from the side toward the auxiliary electrode 36.
AC power supply T_acThe side to which the main electrode 26B is connected is also connected to the auxiliary electrode 36 via the thyristor Th5. Thyristor Th5 also has AC power supply T_acAre connected such that current flows from the side to which the main electrode 26B is connected toward the auxiliary electrode 36.
An anode current flows through the auxiliary electrode 36 when any of the thyristors Th4 and Th5 is ignited. Therefore, by controlling the phase of the thyristors Th4 and Th5, the current value of the anode current flowing through the auxiliary electrode 36 can be controlled._c/ Q_aThe value of can also be controlled.
[0080]
The operation of the electrolytic surface roughening treatment apparatus 104 will be described below.
From the left in FIG. 4, the aluminum plate W is first guided into the auxiliary electrolytic cell 34 by the upstream guide roller 35 and then guided to the AC electrolytic cell main body 22 by the upstream guide roller 30A. Then, the paper is fed from the left side to the right side in FIG. 4 by the feed roller 24 and is led out by the downstream guide roller 30B.
Inside the AC electrolytic cell main body 22 and the auxiliary electrolytic cell 34, the aluminum web W is applied to the main electrodes 26A and 26B by the alternating current applied to the main electrodes 26A and 26B and the anode current applied to the auxiliary electrode 36. The surface on the facing side is roughened, and almost uniform honeycomb pits are formed.
[0081]
(4) Recycling of waste liquid used for roughening treatment
It is preferable to recycle as much as possible the liquid (waste liquid) used for each roughening treatment.
In an aqueous caustic soda solution in which aluminum ions are dissolved, aluminum and caustic soda can be separated by crystallization. In sulfuric acid aqueous solution, nitric acid aqueous solution or hydrochloric acid aqueous solution in which aluminum ions are dissolved, sulfuric acid or nitric acid can be recovered by electrodialysis or ion exchange resin.
The aqueous hydrochloric acid solution in which aluminum ions are dissolved can be recovered by evaporation as described in JP-A No. 2000-282272.
In the present invention, it is preferable to use the waste liquid of the electrolytic solution used in the electrochemical surface roughening treatment for the desmut treatment.
The desmutting treatment performed before the electrochemical surface roughening treatment or anodizing treatment is preferably performed using the same type of liquid as the surface roughening treatment or anodizing treatment performed after the desmutting treatment. It is particularly preferable to use this solution. By doing so, the water washing step provided between the desmut treatment and the next step can be omitted, and the facility can be simplified and the amount of waste liquid can be reduced.
[0082]
<Chemical etching treatment in alkaline aqueous solution (second alkali etching treatment)>
A second alkali etching treatment is preferably performed after the electrochemical surface roughening treatment. By this treatment, a lithographic printing plate having a uniform surface shape of the aluminum plate and excellent printing durability and printing performance can be obtained.
In the second alkali etching treatment, etching is performed by bringing the aluminum plate into contact with an alkaline solution. The kind of alkali, the method of bringing an aluminum plate into contact with an alkaline solution, and the apparatus used therefor are the same as those in the case of alkali etching treatment.
Examples of the alkali used in the alkaline solution include the same as in the alkali etching treatment.
The concentration of the alkaline solution can be determined according to the etching amount, but is preferably 0.01 to 80% by mass. The temperature of the alkaline solution is preferably 20 to 90 ° C. The treatment time is preferably 1 to 60 seconds.
In the second alkali etching treatment, the dissolution amount of the aluminum plate (surface subjected to the electrolytic surface roughening treatment) is preferably 0.001 to 30 g / m.²More preferably, 0.1 to 10 g / m²And particularly preferably 0.2 to 5 g / m.²It is.
[0083]
<Desmutting treatment in acidic aqueous solution (second desmutting treatment)>
The second desmut treatment is preferably performed after the second alkali etching treatment.
In the second desmutting treatment, for example, the aluminum plate is contacted 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 phosphoric acid, hydrochloric acid, nitric acid, and sulfuric acid. To do. The method for bringing the aluminum plate into contact with the acidic solution may be the same as in the case of the first desmut treatment.
In the second desmut process and the third desmut process, it is preferable to use a waste solution of a sulfuric acid solution discharged in an anodic oxidation process described later as the acidic solution. Instead of the waste liquid, a sulfuric acid solution having a sulfuric acid concentration of 100 to 600 g / L, an aluminum ion concentration of 1 to 10 g / L, and a liquid temperature of 30 to 90 ° C. may be used.
The liquid temperature of the second desmut treatment is preferably 25 to 90 ° C. Moreover, it is preferable that the processing time of a 2nd desmut process is 1-180 second. Aluminum and aluminum alloy components may be dissolved in the acidic solution used for the second desmut treatment.
[0084]
<Anodizing treatment>
Anodization is performed to increase the wear resistance of the surface of the aluminum plate. Any electrolyte can be used as the electrolyte used for the anodizing treatment of the aluminum plate as long as it forms a porous oxide film. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixture thereof is used.
The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, the electrolyte concentration is 1 to 80% by mass, the liquid temperature is 5 to 70 ° C., and the current density is 1 to 60 A / dm.²It is appropriate if the voltage is in the range of 1 to 100 V and the electrolysis time is 10 seconds to 300 seconds. The sulfuric acid method is usually treated with a direct current, but alternating current can also be used. The amount of anodized film is 1-5g / m²The range of is appropriate. 1g / m²If it is less, the printing durability will be insufficient, or the non-image area of the lithographic printing plate will be easily damaged, and at the same time, ink will adhere to the scratch area, so-called scratch stains will easily occur. Further, as the amount of the anodic oxide film increases, the oxide film tends to concentrate on the aluminum etched portion. Therefore, the difference in the oxide film amount between the etched portion and the central portion of the aluminum plate is 1 g / m.²The following is preferable.
[0085]
Anodization in an aqueous sulfuric acid solution is described in detail in JP-A-54-128453 and JP-A-48-45303. The sulfuric acid concentration is preferably 10 to 300 g / L, and the aluminum ion concentration is preferably 1 to 25 g / L, and the aluminum ion concentration is adjusted to 2 to 10 g / L by adding aluminum sulfate to a 50 to 200 g / L sulfuric acid aqueous solution. Is particularly preferred. The liquid temperature is preferably 30 to 60 ° C. Current density 1-60 A / dm when using DC method², Especially 5-40A / dm²Is preferred. When anodizing the aluminum sheet continuously, it is initially 5-10 A / dm to prevent current concentration called burning of the aluminum plate.²Anodization is performed at a low current density of 30 to 50 A / dm by gradually increasing the current density in the second half.²It is particularly preferred to set the current density until or above. It is preferable to gradually increase the current density in 5 to 15 steps. Each step has an independent power supply, and the current density is controlled by the current value of the power supply. The power supply method is preferably a liquid power supply method that does not use a conductor roller. An example is shown in Japanese Patent Laid-Open No. 2001-11698.
[0086]
Of course, a small amount of trace element contained in the aluminum plate may be dissolved in the sulfuric acid aqueous solution. Since aluminum elutes in the sulfuric acid aqueous solution during the anodizing treatment, it is necessary to manage the sulfuric acid concentration and the aluminum ion concentration in order to manage the process. If the aluminum ion concentration is set low, the sulfuric acid aqueous solution for anodizing must be renewed frequently, and the amount of waste liquid increases, which is not economical and is also an environmental problem. On the other hand, if the aluminum ion concentration is set high, the electrolysis voltage becomes high and the power cost increases, which is not economical. As preferable anodizing sulfuric acid concentration, aluminum ion concentration, liquid temperature,
(Part 1)
Sulfuric acid concentration 100-200 g / L (further 130-180 g / L)
Aluminum ion concentration 2-10 g / L (further 3-7 g / L)
Liquid temperature 30-50 ° C (further 33-45 ° C)
(Part 2)
Sulfuric acid concentration 50-125 g / L (further 80-120 g / L)
Aluminum ion concentration 2-10 g / L (further 3-7 g / L)
Liquid temperature 40-70 (further 50-60 ° C)
It is.
[0087]
There are two methods for supplying power to the aluminum plate power in the anodizing process: a direct power supply method for supplying power directly to the aluminum plate using a conductor roll, and a liquid power supply method for supplying power to the aluminum plate through an electrolytic solution.
The direct power feeding method is a relatively low speed and low current density anodizing device with a line speed of 30 m / min or less, and the indirect power feeding method is often used with a high speed and high current density anodizing device with a line speed exceeding 30 m / min. .
The indirect feeding method can use a Yamakoshi type or straight type tank layout as described on page 289 of the continuous surface treatment technology (General Technology Center, issued on September 30, 1986). At high speed and high current density, there is a problem of spark generation between the conductor roll and the aluminum web, so the direct feeding roll method is disadvantageous.
In both direct power supply and indirect power supply systems, the anodizing process is separated into two or more for the purpose of reducing energy loss due to voltage drop in the aluminum web. It is particularly preferable to use a direct current power source connected between the oxidation tank and the oxidation tank.
In the case of using the direct power supply method, the conductor roll is generally made of aluminum. In order to extend the life of the roll, after casting using industrial pure aluminum as described in Japanese Patent Publication No. 61-50138, high temperature homogenization treatment is performed to obtain an Al-Fe-based crystallized product. Al_ThreeIt is particularly preferable to use a single layer of Fe with improved corrosion resistance.
Since a large current flows in the anodizing process, a Lorentz force acts on the aluminum plate by a magnetic field generated by the current flowing in the bus bar. As a result, there arises a problem that the web meanders. Therefore, it is particularly preferable to use a method as described in JP-A-57-51290.
[0088]
Further, since a large current flows through the aluminum plate, a Lorentz force acts toward the center in the width direction of the aluminum plate by a magnetic field generated by the current flowing through the aluminum plate itself. As a result, the aluminum plate is likely to be broken. Therefore, a plurality of pass rollers having a diameter of 100 to 200 mm are provided at a pitch of 100 to 3000 mm in the anodizing tank, and the fold is caused by Lorentz force by lapping at an angle of 1 to 15 degrees. It is particularly preferred to take a preventive method.
Also, the amount of the anodic oxide film produced differs in the width direction of the aluminum plate, and the amount produced increases as the etching approaches, and the thickness increases. As a result, there arises a problem that the aluminum plate cannot be wound well by the winding device. This can be solved by stirring the liquid flow by the method described in Japanese Patent Publication No. 62-30275 or Japanese Patent Publication No. 55-21840. If that method is insufficient, it is also possible to use a method of winding an aluminum plate winding device by oscillating it in the width direction of the aluminum web with an amplitude of 5 to 50 mm at a period of 0.1 to 10 Hz. Particularly preferred.
[0089]
In the sulfuric acid method, the treatment is usually performed with a direct current, but an alternating current can also be used. The amount of anodized film is 1-10 g / m²The range of is appropriate. In the case of general lithographic printing plate materials, the amount of anodized film is 1-5 g / m.²1g / m²If it is less, the printing durability is insufficient, or the non-image portion of the lithographic printing plate tends to be scratched, and at the same time, so-called scratches and stains, in which ink adheres to the scratched portion, are likely to occur. Further, when the amount of the anodic oxide film increases, the oxide film tends to concentrate on the etched portion of the aluminum plate. Therefore, the difference in the oxide film amount between the etched portion and the central portion of the aluminum plate is 1 g / m.²The following is preferable. In general, the liquid anodization method is used for the continuous anodizing treatment. Lead, iridium oxide, platinum, ferrite, or the like can be used as the anode for passing an electric current through the aluminum plate, but those mainly composed of iridium oxide are particularly preferable. Iridium oxide is coated on the substrate by heat treatment. As the substrate, so-called valve metals such as titanium, tantalum, niobium and zirconium are used, and titanium or niobium is particularly preferable. Since the valve metal has a relatively large electric resistance, it is particularly preferable to use copper as the core material and clad the valve metal around it. When a valve metal is clad on a copper core material, it is not possible to make a very complicated shape, so the electrode parts created by dividing each part are covered with iridium oxide and then the desired structure with bolts and nuts etc. It is common to assemble so that it becomes.
[0090]
In the present invention, the acid waste liquid generated in the anodizing treatment is desmutted (first, second and third desmutting) in that the desmutting solution feeding equipment and concentration adjusting equipment can be simplified and the equipment cost can be reduced. It is preferable to use for.
[0091]
<Hydrophilic treatment>
As the hydrophilization treatment, a known hydrophilization treatment generally used in the production of a lithographic printing plate support can be used, but it is preferable to treat with an alkali metal silicate, which will be described in detail below.
After the anodized support is washed with water, the dissolution of the anodized film in the developer is suppressed, the residual film of the image recording layer component is suppressed, the anodized film strength is improved, the hydrophilicity of the anodized film is improved, and the image The following treatments can be performed for the purpose of improving the adhesion with the recording layer. One of them is a silicate treatment in which the anodized film is treated by contacting with an alkali metal silicate aqueous solution. In this case, the concentration of the alkali metal silicate is 0.1 to 30% by mass, preferably 0.5 to 15% by mass, more preferably 0.8 to 3.0% by mass, at 25 ° C. The aqueous solution having a pH of 10 to 13.5 is contacted at 5 to 80 ° C, preferably 10 to 70 ° C, more preferably 15 to 50 ° C for 0.5 to 120 seconds. The contact method may be any method, such as dipping or spraying. If the pH of the alkali metal silicate aqueous solution is lower than 10, the solution may gel, and if it is higher than 13.5, the anodized film may be dissolved.
As the alkali metal silicate used in the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used. Examples of the hydroxide used for pH adjustment of the alkali metal silicate aqueous solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, you may mix | blend an alkaline-earth metal salt or a Group IVA (Group 4) metal salt with the said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Is mentioned. Examples of Group IVA (Group 4) metal salts include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium potassium oxalate, titanium sulfate, titanium tetraiodide, and zirconium chloride oxide. Alkaline earth metals or Group IVA (Group 4) metal salts may be used alone or in combination of two or more. A preferable range of these metal salts is 0.01 to 10% by mass, and more preferably 0.05 to 5.0% by mass.
[0092]
<Sealing treatment>
In addition, various sealing treatments are also mentioned, and generally known as a sealing treatment method for an anodized film, water vapor sealing, boiling water (hot water) sealing, metal salt sealing (chromate). / Bichromate sealing, nickel acetate sealing, etc.), oil impregnation sealing, synthetic resin sealing, low temperature sealing (due to red blood salt, alkaline earth salt, etc.), etc. Water vapor sealing is relatively preferable from the standpoints of performance as a support for a substrate (adhesion and hydrophilicity with an image recording layer), high-speed processing, low cost, low pollution, and the like. As the method, for example, pressurized or normal pressure steam described in JP-A-4-176690 is continuously or non-continuously set at a relative humidity of 70% or more and a steam temperature of 95 ° C. or more for 2 to 180 seconds. The method etc. which are made to contact an anodic oxide film are mentioned. As another sealing treatment method, a method of immersing or spraying the support in hot water or an alkaline aqueous solution of about 80 to 100 ° C., or in place of this, or subsequently immersing or spraying with a nitrous acid solution Can do. Examples of nitrite contained in the nitrite solution include, for example, LiO₂, NaNO₂, KNO₂, Mg (NO₂)₂, Ca (NO₂)₂, Zn (NO_Three)₂, Al (NO₂)_Three, Zr (NO₂)_Four, Sn (NO₂)_Three, Cr (NO₂)_Three, Co (NO₂)₂, Mn (NO₂)₂, Ni (NO₂)₂Etc., and alkali metal nitrates are particularly preferable. Two or more kinds of nitrites can be used in combination.
[0093]
The treatment conditions differ depending on the state of the support and the type of alkali metal, and therefore cannot be determined uniquely. For example, when sodium nitrite is used, the concentration is generally 0.001 to 10% by mass, Preferably, it is 0.01-2% by mass, the bath temperature is generally from room temperature to about 100 ° C., more preferably 60-90 ° C., and the treatment time is generally 15-300 seconds, more preferably 10-180. Select from each range of seconds. The pH of the aqueous nitrous acid solution is preferably adjusted to 8.0 to 11.0, particularly preferably 8.5 to 9.5. In order to adjust the pH of the aqueous nitrous acid solution to the above range, for example, an alkaline buffer solution can be preferably used. Examples of the alkaline buffer include, but are not limited to, a mixed aqueous solution of sodium bicarbonate and sodium hydroxide, a mixed aqueous solution of sodium carbonate and sodium hydroxide, a mixed aqueous solution of sodium carbonate and sodium bicarbonate, sodium chloride and sodium hydroxide. A mixed aqueous solution, a mixed aqueous solution of hydrochloric acid and sodium carbonate, a mixed aqueous solution of sodium tetraborate and sodium hydroxide, or the like can be suitably used. The alkali buffer may be an alkali metal salt other than sodium, such as a potassium salt. After the silicate treatment or the sealing treatment as described above, an acidic aqueous solution treatment and a hydrophilic undercoat described in JP-A-5-278362 are performed in order to improve the adhesion with the image recording layer. Alternatively, an organic layer described in JP-A-4-282737 and JP-A-7-314937 may be provided.
[0094]
In the production of the lithographic printing plate support of the present invention, the following treatment can be performed in addition to the above treatment.
[0095]
<Washing method of aluminum plate>
After the aluminum plate is treated in an acid or alkaline aqueous solution or mechanically roughened with an abrasive, it is usual to provide a cleaning step for the purpose of removing the chemical solution or abrasive from the aluminum plate surface. is there.
Cleaning is usually provided in the middle of treatment tanks of different types and compositions, but the time from the treatment tank to the cleaning process or the time from washing to the next treatment tank is preferably 10 seconds or less. 0.1 to 10 seconds is particularly preferable. If it exceeds 10 seconds, chemical modification of the surface proceeds and processing unevenness may easily occur.
Further, the interval between the treatment tanks sandwiching the water washing step is preferably 15 seconds or less, particularly preferably 5 seconds or less in terms of the passage time of the aluminum web. If it exceeds 15 seconds, chemical modification of the surface proceeds and it may be difficult to perform uniform surface roughening in the next step.
In washing the aluminum plate, the following method is preferably used, and a water washing method using dry ice powder is preferred for the purpose of reducing the amount of drainage.
[0096]
(1) Washing with water
As a method for cleaning a lithographic printing plate support, it is common to use a method in which the surface that has been drained with a nip roller is cleaned with water sprayed from a spray tip. It is preferable that water is injected at an angle of 45 to 90 degrees toward the downstream in the traveling direction of the aluminum plate. The water injection pressure is the pressure just before the injection nozzle, usually 0.5 to 5 kg / cm²The liquid temperature is preferably 10 to 80 ° C. The traveling speed of the traveling aluminum plate is preferably 20 to 200 m / min. The amount of water sprayed on the aluminum plate is 0.1 to 10 L / m in one washing process.²It is preferable that the amount of liquid is sprayed. In one cleaning tank, cleaning water is sprayed from at least two spray tubes on the surface of the aluminum plate and at least two spray tubes on the back surface. One spray tube is provided with 5 to 30 spray tips at a pitch of 50 to 200 mm. The spray angle of the spray tip is preferably 10 to 150 degrees, and the distance between the aluminum plate and the spray tip injection surface is preferably 10 to 250 mm. The cross-sectional shape (spray pattern) of spraying of the spray tip includes an annular shape, a circular shape, an oval shape, a square shape, a rectangular shape, and the like, and a circular shape, a round shape, a square shape or a rectangular shape is preferable. The flow distribution (spray water distribution state on the surface of the aluminum plate) includes annular distribution, uniform distribution, mountain distribution, etc., but when using multiple spray tips side by side in a spray tube, the uniform flow distribution over the entire width A mountain distribution that facilitates the above is preferred. The flow distribution varies depending on the spray pressure and the distance between the spray tip and the aluminum plate. The particle diameter of the spray varies depending on the structure of the spray tip, the spray pressure, and the spray amount, but is preferably 10 to 10,000 μm, particularly preferably 100 to 1000 μm. The material of the spray nozzle is preferably wear resistant against liquid flowing at high speed. The material used is brass, stainless steel, ceramic or the like, and a ceramic nozzle is particularly preferable.
The spray nozzle on which the spray tip is installed can be arranged at 45 to 90 degrees with respect to the traveling direction of the aluminum plate, but the longer center line of the spray pattern center is perpendicular to the traveling direction of the aluminum plate. It is preferable that
The washing time for passing through the water washing treatment process is industrially preferably 10 seconds or less, particularly preferably 0.5 to 5 seconds.
[0097]
(2) Cleaning with dry ice powder
A known shot blasting apparatus as described in JP-A No. 10-66905 can be used as a method for cleaning by spraying dry ice powder on both sides of an aluminum plate. As the spray nozzle, a plurality of known spray nozzles as described in JP-A-10-28901 and JP-A-10-28902 can be arranged on both surfaces of an aluminum plate. The spray nozzles may be arranged in a horizontal line, but it is preferable that the spray nozzles be installed obliquely so that the spray pattern on the surface of the aluminum plate overlaps in the width direction of the aluminum plate. The distance between the spray nozzle and the aluminum plate is preferably 1 to 100 mm, particularly preferably 10 to 50 mm.
Moreover, the manufacturing apparatus as described in Unexamined-Japanese-Patent No. 7-38104 can be used for the method of manufacturing powdery dry ice. As the gas for injection, GN2 gas or air can be used. Powdered dry ice is 1-1000 μm, and the average particle size is preferably 10-100 μm. LCO per injection nozzle₂(Liquid carbon dioxide) The supply amount is preferably 0.1 to 1 kg / min, and the supply pressure is preferably 1 to 20 MPa. The washing pressure on the aluminum plate is preferably 1 to 20 MPa.
[0098]
<Material of pass roll>
The roll can be selected and used from metal rolls, resin rolls, rubber rolls and non-woven rolls used in continuous production lines such as known steels plated or lined on the surface, plating, electrolytic capacitors, lithographic printing plate precursors, etc. .
The material of the roll and the physical properties of the surface are selected in consideration of the corrosion resistance, wear resistance, heat resistance, chemical resistance, etc. according to the chemical solution and the state of the aluminum surface at that time. As the metal roll, a hard chrome plating roll is generally used. In rubber rolls, natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, butyl rubber, chloroprene rubber, chlorosulfonated polyethylene, nitrile rubber, acrylic rubber, epichlorohydrin rubber, urethane rubber, polysulfide rubber, fluorine rubber, etc. What added the additive can be used. The international rubber hardness (specified in JIS K6253) of the rubber roll is particularly preferably 60 to 90.
[0099]
According to the method for producing a lithographic printing plate support described in detail above, a low-purity aluminum plate (an aluminum plate containing a large amount of alloy components or an aluminum plate not prepared with alloy components) is used. In addition, it is possible to obtain a lithographic printing plate support having a uniform surface irregularity. Further, the lithographic printing plate support obtained by the above-described method for producing a lithographic printing plate support is provided with an image recording layer as will be described later to form a lithographic printing plate precursor according to the present invention. When used as a printing plate, it has excellent printing performance and printing durability.
[0100]
[Lithographic printing plate precursor]
The lithographic printing plate precursor according to the invention can be obtained by providing an image recording layer capable of forming an image with heat on the lithographic printing plate support described above.
[0101]
<Undercoat layer>
In the present invention, before providing the image recording layer on the lithographic printing plate support thus obtained, if necessary, an inorganic layer such as a water-soluble metal salt such as zinc borate is used. A coating layer or an organic undercoat layer may be provided.
[0102]
Examples of organic compounds used in the organic undercoat layer include carboxymethyl cellulose; dextrin; gum arabic; polymers and copolymers having a sulfo group in the side chain; polyacrylic acid; amino groups such as 2-aminoethylphosphonic acid Phosphonic acids having a substituent; organic phosphonic acids such as phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid, ethylenediphosphonic acid, which may have a substituent; Organic phosphoric acid such as phenyl phosphoric acid, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphoric acid which may be substituted; Organic such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent Phosphinic acid; amino acids such as glycine and β-alanine; Amine hydrochloride having hydroxy group such as hydrochloride of triethanolamine; include yellow dyes. Among them, a polymer compound having a component having an acid group is preferably used, and particularly a polymer compound having a component having an onium group together with a component having an acid group is preferably used. These may be used alone or in combination of two or more.
[0103]
(High molecular compound having a component having an acid group)
The acid group used for the polymer compound having a component having an acid group includes an acid dissociation index (pK_a) Is preferably 7 or less, more preferably —COOH, —SO_ThreeH, -OSO_ThreeH, -PO_ThreeH₂, -OPO_ThreeH₂, -CONHSO₂, -SO₂NHSO₂-, Particularly preferably -COOH. The component having an acid group may be used alone or in combination of two or more.
The polymer is preferably a polymer whose main chain structure is vinyl polymer such as acrylic resin, methacrylic resin or polystyrene, urethane resin, polyester or polyamide. Among these, a vinyl polymer such as an acrylic resin, a methacrylic resin, or polystyrene is preferable for the main chain structure.
[0104]
Further, when the polymer compound has a component having an onium group, an onium group is preferably an onium containing an atom of Group 15 (Group VB) or Group 16 (Group VIB) of the periodic table. More preferably an onium group containing a nitrogen atom, a phosphorus atom or a sulfur atom, and particularly preferably an onium group containing a nitrogen atom.
The polymer compound preferably contains 1 mol% or more of the constituent component having an onium group as described above, and more preferably contains 5 mol% or more. When the component having an onium group is contained in an amount of 1 mol% or more, the adhesion is further improved.
[0105]
The polymer compound having a component having an onium group preferably contains 20 mol% or more, more preferably 40 mol% or more of a component having an acid group. When the component having an acid group is contained in an amount of 20 mol% or more, dissolution and removal during alkali development is further promoted, and the adhesiveness is further improved by the synergistic effect of the acid group and the onium group. Moreover, the structural component which has an onium group may be used independently, or may be used in combination of 2 or more type.
[0106]
The polymer compound used for forming the undercoat layer may be a mixture of two or more compounds having different constituent components, composition ratios or molecular weights.
[0107]
Next, typical examples of the polymer compound having a component having an onium group together with a component having an acid group are shown below. The composition ratio of the polymer structure represents a mole percentage.
[0108]
[Chemical 1]

[0109]
[Chemical formula 2]

[0110]
[Chemical Formula 3]

[0111]
[Formula 4]

[0112]
[Chemical formula 5]

[0113]
The polymer compound used for forming the undercoat layer can be generally produced by a radical chain polymerization method (“Textbook of Polymer Science” 3rd ed. (1984) FW Billmeyer, AWiley-Interscience). Publication).
[0114]
The molecular weight of the polymer compound may be in a wide range, but when measured using a light scattering method, the weight average molecular weight (M_w) Is preferably from 500 to 2,000,000, more preferably from 1,000 to 600,000. The amount of unreacted monomer contained in the polymer compound may be in a wide range, but is preferably 20% by mass or less, more preferably 10% by mass or less.
[0115]
(Manufacturing method of polymer compound for undercoat layer formation)
Next, a synthesis example of a polymer compound having a component having an onium group as well as a component having an acid group is a copolymer of p-vinylbenzoic acid and vinylbenzyltrimethylammonium chloride mentioned above (No. .1) is taken as an example, but other polymer compounds can be synthesized in the same manner.
[0116]
146.9 g (0.99 mol) of p-vinylbenzoic acid (manufactured by Hokuko Chemical Co., Ltd.), 44.2 g (0.21 mol) of vinylbenzyltrimethylammonium chloride and 446 g of 2-methoxyethanol are placed in a 1 L three-necked flask. While stirring under a nitrogen stream, the mixture was heated and kept at 75 ° C. To this solution, 2.76 g (12 mmol) of dimethyl 2,2-azobis (isobutyrate) was added and stirring was continued. Two hours later, 2.76 g (12 mmol) of 2,2-azobis (isobutyric acid) dimethyl was further added, and stirring was continued. After stirring for 2 hours, the mixture was allowed to cool to room temperature. The reaction solution was poured into 12 L of ethyl acetate under stirring. The precipitated solid was collected by filtration and dried. The yield was 189.5g. As a result of measuring the molecular weight of the obtained solid by a light scattering method, the weight average molecular weight (M_w) Was 32,000.
[0117]
(Formation of undercoat layer)
The undercoat layer can be provided by applying the polymer compound on the above-described lithographic printing plate support by various methods.
As a method for providing the undercoat layer, for example, an organic solvent such as methanol, ethanol, methyl ethyl ketone or a mixed solvent thereof or a solution obtained by dissolving the above polymer compound in a mixed solvent of these organic solvent and water is used in a lithographic printing plate. In a method of coating on a support for application and drying, an organic solvent such as methanol, ethanol, methyl ethyl ketone or a mixed solvent thereof or a solution obtained by dissolving the above polymer compound in a mixed solvent of these organic solvent and water, Examples include a method in which a lithographic printing plate support is immersed to adsorb a polymer compound, and then washed with water and dried.
[0118]
In the former method, a solution having a concentration of 0.005 to 10% by mass of the polymer compound can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, or curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by mass, preferably 0.05% to 5% by mass, and the immersion temperature is 20 ° C. to 90 ° C., preferably 25 to 50 ° C. The immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute.
[0119]
The above solutions include basic substances such as ammonia, triethylamine and potassium hydroxide; inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid and nitric acid; organic sulfonic acids such as nitrobenzene sulfonic acid and naphthalene sulfonic acid; organic such as phenylphosphonic acid Various organic acidic substances such as organic carboxylic acids such as phosphonic acid, benzoic acid, coumaric acid, malic acid; pH adjusted with organic acid chloride such as naphthalenesulfonyl chloride, benzenesulfonyl chloride, etc., pH 0-12, more preferably It can also be used in the range of pH 0-5.
The coating amount after drying of the polymer compound forming the undercoat layer is 2 to 100 mg / m.²Is suitable, preferably 5 to 50 mg / m²It is. The coating amount is 2 mg / m²If it is less, sufficient effects may not be obtained. 100 mg / m²The same applies to the case where there are more.
[0120]
<Image recording layer>
As an image recording layer capable of forming an image by heat, for example, a thermal positive type, a thermal negative type, and a non-processing type are preferably exemplified. Hereinafter, the thermal positive type image recording layer which is preferably used will be described.
[0121]
The thermal positive type image recording layer contains (A) a water-insoluble and alkali-soluble resin (hereinafter referred to as “alkali-soluble resin”) and (B) an infrared absorber.
[0122]
(A) Alkali-soluble resin
The (A) alkali-soluble resin that can be used in the thermal positive type image recording layer includes a homopolymer, a copolymer or a mixture thereof containing an acidic group in the main chain and / or side chain in the polymer. Regarding the acidic group, it may be introduced by any of a method of polymerizing and introducing a monomer having an acidic group in advance, a method of introducing by a polymer reaction after polymerization, and a method of using them together. .
[0123]
The alkali-soluble resin is not particularly limited. For example, Plastic Age Co., Ltd. “Phenol Resin”, IPC Co., Ltd. “Synthesis / Curing / Toughening and Application of Phenol Resin”, Nikkan Kogyo Shimbun “Plastic Materials” Phenol resin, polyhydroxystyrene, polyhalogenated hydroxystyrene, N- (4-hydroxyphenyl) methacrylic resin described in books such as "Lecture 15 Phenolic Resin", Industrial Research Co., Ltd. Amide copolymer, hydroquinone monomethacrylate copolymer; sulfonylimide polymer described in JP-A-7-28244; carboxy group-containing polymer described in JP-A-7-36184; As described in Japanese Patent No. 51-34711 Acrylic resins containing phenolic hydroxy groups; various alkali-soluble polymer compounds such as acrylic resins and urethane resins having sulfonamide groups described in JP-A-2-866 can be used. .
Among these, those having the following acidic groups (1) to (6) in the main chain and / or side chain of the polymer are preferable from the viewpoint of solubility in an alkaline developer and expression of dissolution inhibiting ability.
[0124]
(1) Phenolic hydroxy group (—Ar—OH)
(2) Sulfonamide group (—SO₂NH-R)
(3) Substituted sulfonamide acid group (—SO₂NHCOR, -SO₂NHSO₂R, -CONHSO₂R) (hereinafter referred to as “active imide group”)
(4) Carboxy group (—CO₂H)
(5) Sulfo group (—SO_ThreeH)
(6) Phosphate group (-OPO_ThreeH₂)
[0125]
In the above (1) to (6), Ar represents a divalent aryl linking group which may have a substituent, and R represents a hydrocarbon group which may have a substituent.
[0126]
Among the alkali-soluble resins having an acidic group selected from the above (1) to (6), (1) phenolic hydroxy group, (2) sulfonamide group, (3) active imide group, and (4) carboxylic acid group Among them, an alkali-soluble resin having at least one of them is preferred, and in particular, an alkali-soluble resin having at least one of (1) phenolic hydroxy group, (2) sulfonamide group and (4) carboxylic acid group is used for alkaline development. It is more preferable from the viewpoints of solubility in a liquid, development latitude, and film strength of an image recording layer.
[0127]
Examples of the alkali-soluble resin having an acidic group of (1) to (6) above include the following.
(1) Examples of the alkali-soluble resin having a phenolic hydroxy group include novolak resins, resol resins, polyvinylphenol resins, and acrylic resins having a phenolic hydroxy group. Among these, novolak resins, resol resins, and polyvinylphenol resins are preferable from the viewpoints of image forming properties and thermosetting properties, and novolak resins and polyvinylphenol resins are more preferable from the viewpoint of stability, and novolaks from the viewpoint of raw material availability and versatility. Resins are particularly preferred.
[0128]
Examples of the novolak resin include phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, o-ethylphenol, m-ethylphenol, p-ethylphenol, propylphenol. , N-butylphenol, tert-butylphenol, 1-naphthol, 2-naphthol, pyrocatechol, resorcinol, hydroquinone, pyrogallol, 1,2,4-benzenetriol, phloroglucinol, 4,4'-biphenyldiol, 2,2 -At least one phenol such as bis (4'-hydroxyphenyl) propane is reacted with an aldehyde (formaldehyde, for example, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, furfural) under an acidic catalyst. Paraformaldehyde instead of de, instead of acetaldehyde may be used paraldehyde.), Or refers acetone, methyl ethyl ketone, that at least one and polycondensation resin obtained by the ketones such as methyl isobutyl ketone.
[0129]
In the present invention, as phenols, at least one of phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol and resorcinol is used as aldehydes or ketones. Polycondensates using at least one of formaldehyde, acetaldehyde and propionaldehyde are preferred. In particular, the mixing ratio of m-cresol: p-cresol: 2,5-xylenol: 3,5-xylenol: resorcinol is 40 to 100: 0 to 50: 0 to 20: 0 to 20: 0 to 20 in molar ratio. A polycondensate of a certain mixed phenol or a phenol / m-cresol: p-cresol with a molar ratio of 0-100: 0 to 70: 0-60 (mixed) and formaldehyde preferable.
[0130]
The thermal positive type image recording layer preferably used in the present invention preferably contains a solvent inhibitor. In that case, the mixing ratio of m-cresol: p-cresol: 2,5-xylenol: 3,5-xylenol: resorcinol is 70 to 100: 0 to 30: 0 to 20: 0 to 20: 0 in molar ratio. Polycondensation of 20 mixed phenols, or phenol: m-cresol: p-cresol with a molar ratio of 10-100: 0 to 60: 0-40 (mixed) and formaldehyde The body is preferred.
[0131]
Examples of the alkali-soluble resin having a phenolic hydroxy group include a polymer of a polymerizable monomer having a phenolic hydroxy group.
Examples of the polymerizable monomer having a phenolic hydroxy group include acrylamide, methacrylamide, acrylic ester, methacrylic ester or hydroxystyrene having a phenolic hydroxy group.
Specifically, N- (2-hydroxyphenyl) acrylamide, N- (3-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) acrylamide, N- (2-hydroxyphenyl) methacrylamide, N- (3 -Hydroxyphenyl) methacrylamide, N- (4-hydroxyphenyl) methacrylamide, o-hydroxyphenyl acrylate, m-hydroxyphenyl acrylate, p-hydroxyphenyl acrylate, o-hydroxyphenyl methacrylate, m-hydroxyphenyl methacrylate, p- Hydroxyphenyl methacrylate, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (2-hydroxyphenyl) ethyl acrylate, 2- (3-hydroxyphenyl) Preferred are ethyl acrylate, 2- (4-hydroxyphenyl) ethyl acrylate, 2- (2-hydroxyphenyl) ethyl methacrylate, 2- (3-hydroxyphenyl) ethyl methacrylate, 2- (4-hydroxyphenyl) ethyl methacrylate, and the like. Can be used.
[0132]
Alternatively, the acid group precursor may be polymerized and polymerized, and then derived into an acid group. For example, after polymerizing p-acetoxystyrene as an acid group precursor, the ester moiety may be hydrolyzed to be a phenolic hydroxy group.
Further, phenol and formaldehyde having a C 3-8 alkyl group as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, as described in US Pat. No. 4,123,279, The condensation polymer of can also be illustrated suitably.
[0133]
(2) As an alkali-soluble resin having a sulfonamide group, for example, a polymer composed of a minimum constituent unit derived from a compound having a sulfonamide group as a main constituent can be mentioned. Examples of such compounds include compounds each having at least one sulfonamide group in which at least one hydrogen atom is bonded to a nitrogen atom and one or more polymerizable unsaturated groups in the molecule. Among these, a low molecular compound having an acryloyl group, an allyl group or a vinyloxy group and a mono-substituted aminosulfonyl group or a substituted sulfonylimino group in the molecule is preferable. Examples thereof include compounds represented by the following general formulas (I) to (V).
[0134]
[Chemical 6]

[0135]
Where X¹And X²Are —O— or —NR, respectively.⁷-Is shown. R¹And R^FourAre each a hydrogen atom or —CH_ThreeRepresents. R², R^Five, R⁹, R¹²And R¹⁶Represents an alkylene group having 1 to 12 carbon atoms, a cycloalkylene group, an arylene group or an aralkylene group, each of which may have a substituent. R^Three, R⁷And R¹³Represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, each optionally having a substituent. R⁶And R¹⁷Represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, each optionally having a substituent. R⁸, R^TenAnd R¹⁴Is a hydrogen atom or -CH_ThreeRepresents. R¹¹And R¹⁵Each represents a single bond or an alkylene group having 1 to 12 carbon atoms, a cycloalkylene group, an arylene group or an aralkylene group which may have a substituent. Y¹And Y²Each represents a single bond or —CO—. Specifically, m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be preferably used.
[0136]
(3) As an alkali-soluble resin having an active imide group, for example, a polymer composed of a minimum constituent unit derived from a compound having an active imide group as a main constituent can be mentioned. Examples of the above compound include compounds each having one or more active imide groups represented by the following structural formula and polymerizable unsaturated groups in the molecule.
[0137]
[Chemical 7]

[0138]
As such a compound, specifically, N- (p-toluenesulfonyl) methacrylamide, N- (p-toluenesulfonyl) acrylamide and the like can be preferably used.
[0139]
(4) As an alkali-soluble resin having a carboxylic acid group, for example, a minimum constituent unit derived from a compound having at least one carboxylic acid group and one or more polymerizable unsaturated groups in the molecule is used as a main constituent component. A polymer can be mentioned.
(5) As the alkali-soluble resin having a sulfo group, for example, a polymer having as a main constituent unit a minimum constituent unit derived from a compound having at least one sulfo group and at least one polymerizable unsaturated group in the molecule. Can be mentioned.
(6) As an alkali-soluble resin having a phosphate group, for example, the minimum constituent unit derived from a compound having at least one phosphate group and at least one polymerizable unsaturated group in the molecule is used as a main constituent component. A polymer can be mentioned.
[0140]
The minimum structural unit having an acidic group selected from the above (1) to (6) is not particularly limited to one kind, and two or more minimum structural units having the same acidic group or different acidic groups are included. What copolymerized 2 or more types of minimum structural units can also be used.
[0141]
The copolymer preferably contains 10 mol% or more of a compound having an acidic group selected from the above (1) to (6) to be copolymerized, and is contained in an amount of 20 mol% or more. It is more preferable. If it is less than 10 mol%, the alkali solubility tends to be insufficient, and the effect of improving the development latitude may not be sufficiently achieved.
[0142]
When the compound is copolymerized and an alkali-soluble resin is used as the copolymer, other compounds not containing the acidic groups (1) to (6) can be used as the copolymerized compound. Examples of other compounds not containing an acidic group of (1) to (6) include the compounds listed in the following (m1) to (m13), but are not limited thereto.
[0143]
(M1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxy group such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate,
(M2) alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate,
(M3) alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, glycidyl methacrylate,
[0144]
(M4) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide,
(M5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether,
(M6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate,
[0145]
(M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene, p-acetoxystyrene,
(M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone,
(M9) Olefin such as ethylene, propylene, isobutylene, butadiene, isoprene,
[0146]
(M10) N-vinylpyrrolidone, acrylonitrile, methacrylonitrile, etc.
(M11) unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide,
(M12) Maleic anhydride, itaconic anhydride, acrylic acid chloride, methacrylic acid chloride, etc.
(M13) A methacrylic acid monomer in which a hetero atom is bonded to the α-position (for example, compounds described in Japanese Patent Application Nos. 2001-115595 and 2001-115598).
[0147]
In the present invention, the alkali-soluble resin comprises (1) a polymerizable monomer having a phenolic hydroxy group, (2) a polymerizable monomer having a sulfonamide group, (3) a polymerizable monomer having an active imide group, (4) carvone. In the case of a homopolymer or copolymer of a polymerizable monomer having an acid group, (5) a polymerizable monomer having a sulfo group, and (6) a polymerizable monomer having a phosphate group, polystyrene by gel permeation chromatography measurement The weight average molecular weight in terms of conversion (hereinafter simply referred to as “weight average molecular weight”) is preferably 2,000 or more and the number average molecular weight is 500 or more, and more preferably, the weight average molecular weight is 5,000 to 300,000. The number average molecular weight is 800 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1. It is those of 1 to 10.
In the present invention, when the alkali-soluble resin is a novolak resin, it is preferable that the weight average molecular weight is 500 to 100,000 and the number average molecular weight is 200 to 50,000. You may use the novolak resin with few ratios of a low molecular component, especially a residual monomer component as described in Japanese Patent Application 2001-126278.
[0148]
These alkali-soluble resins can be used alone or in combination of two or more, and are 30 to 99% by mass, preferably 40 to 95% by mass, particularly preferably 50 to 90% in the total solid content of the image recording layer. Used in an amount of mass%.
If the total addition amount of the alkali-soluble resin is less than 30% by mass, the durability of the image recording layer may be deteriorated, and if it exceeds 99% by mass, it may be undesirable from the viewpoint of sensitivity and image formability.
[0149]
When an alkali-soluble resin is used in combination, any combination may be used. Particularly suitable examples include a combination of a polymer having a phenolic hydroxy group and a polymer having a sulfonamidic acid group, and a phenolic hydroxy group. A polymer having a carboxylic acid group, a combination of two or more polymers having a phenolic hydroxy group, for example, t-butylphenol as described in US Pat. No. 4,123,279 A condensation polymer of phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as a condensation polymer of aldehyde and formaldehyde or a condensation polymer of octylphenol and formaldehyde, Japanese Patent Application Laid-Open No. 2000-241972 That have an electron-withdrawing group on the aromatic ring It can be given in combination with alkali-soluble resins having Le structure.
[0150]
(B) Infrared absorber
The infrared absorber used in the present invention is not limited in the absorption wavelength range as long as it absorbs light energy radiation and generates heat, but from the viewpoint of compatibility with an easily available high-power laser, the wavelength Preferred examples include infrared absorbing dyes or pigments having an absorption maximum at 700 to 1200 nm.
[0151]
As the dye, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, naphthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, (thio) pyrylium salts And dyes such as metal thiolate complexes, indoaniline metal complex dyes, oxonol dyes, diimonium dyes, aminium dyes, croconium dyes, and intermolecular CT dyes.
[0152]
As preferable dyes, for example, cyanine dyes described in JP-A Nos. 58-125246, 59-84356, 59-202929, and 60-78787, Methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, JP-A-58-112793, JP-A-58-224793 Naphthoquinone dyes described in JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc., JP-A-58-112792 And squarylium dyes described in Japanese Patent Publication No. Gazette, and cyanine dyes described in British Patent No. 434,875.
[0153]
Further, near infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used, and substitutions described in US Pat. No. 3,881,924 are also preferred. Arylbenzo (thio) pyrylium salts prepared, trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, JP-A-59-84248, JP-A-59-84249, JP-A-59-146063, JP-A-59-146061, JP Cyanine dyes described in Japanese Patent No. 59-216146, pentamethine thiopyrylium salt described in US Pat. No. 4,283,475, Pyrylium compounds described in -13514 JP and the 5-19702 JP also preferably used.
[0154]
Another preferable example of the dye includes near infrared absorbing dyes described as formulas (I) and (II) in US Pat. No. 4,756,993.
[0155]
Particularly preferred among these dyes are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes. Furthermore, the dye represented by the following general formula (a) is preferable because of excellent photothermal conversion efficiency. Further, the cyanine dye represented by the following general formula (a) gives high interaction with an alkali-soluble resin when used in an image recording layer composition suitably used in the present invention, and is stable. It is preferable because it is economical.
[0156]
[Chemical 8]

[0157]
In general formula (a), R¹And R²Each independently represents an alkyl group having 1 to 12 carbon atoms, and the alkyl group is selected from the group consisting of an alkoxy group, an aryl group, an amide group, an alkoxycarbonyl group, a hydroxy group, a sulfo group, and a carboxy group. May have a substituent. Y¹And Y²Each independently represents oxygen, sulfur, selenium, a dialkylmethylene group or —CH═CH—. Ar¹And Ar²Each independently represents an aromatic hydrocarbon group and may have a substituent selected from the group consisting of an alkyl group, an alkoxy group, a halogen atom and an alkoxycarbonyl group;¹And Y²An aromatic ring may be condensed with two consecutive carbon atoms adjacent to each other.
[0158]
X represents a counter ion necessary for charge neutralization, and is not always necessary when the dye cation moiety has an anionic substituent.
Q represents a polymethine group selected from the group consisting of a trimethine group, a pentamethine group, a heptamethine group, a nonamethine group, and an undecamethine group. A pentamethine group, a heptamethine group or a nonamethine group is preferable from the viewpoint of wavelength suitability and stability with respect to infrared rays used for exposure, and it is stable to have a cyclohexene ring or a cyclopentene ring containing three consecutive methine chains on any carbon. This is preferable.
[0159]
Q is an alkoxy group, aryloxy group, alkylthio group, arylthio group, dialkylamino group, diarylamino group, halogen atom, alkyl group, aralkyl group, cycloalkyl group, aryl group, oxy group, iminium base, and the following general formula (2 It may be substituted with a group selected from the group consisting of substituents represented by: Preferable substituents include halogen atoms such as chlorine atoms, diarylamino groups such as diphenylamino groups, and arylthio groups such as phenylthio groups.
[0160]
[Chemical 9]

[0161]
Where R^ThreeAnd R^FourEach independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms;^ThreeRepresents an oxygen atom or a sulfur atom.
[0162]
Among the cyanine dyes represented by the general formula (a), when exposure is performed with infrared rays having a wavelength of 800 to 840 nm, heptamethine cyanine dyes represented by the following general formula (a-1) are particularly preferable. .
[0163]
[Chemical Formula 10]

[0164]
In general formula (a-1), X¹Represents a hydrogen atom or a halogen atom. R¹And R²Each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the recording layer coating solution, R¹And R²Is preferably a hydrocarbon group having 2 or more carbon atoms, and further R¹And R²Are particularly preferably bonded to each other to form a 5-membered ring or a 6-membered ring.
[0165]
Ar¹And Ar²Each independently represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y¹And Y²Each independently represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R^ThreeAnd R^FourEach independently represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxy groups, and sulfo groups. R^Five, R⁶, R⁷And R⁸Each independently represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Z_a ^-Represents a counter anion necessary for charge neutralization and R¹~ R⁸Z is substituted with an anionic substituent_a ^-Is not necessary. Preferred Z_a ^-Is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, a tetrafluoroborate ion, from the storage stability of the recording layer coating solution. Hexafluorophosphate ions and sulfonate ions. The heptamethine dye represented by the general formula (a-1) can be suitably used for a thermal positive type image recording layer, and in particular, a so-called interaction cancellation type thermal combined with an alkali-soluble resin having a phenolic hydroxy group. It is preferably used for a positive type image recording layer.
[0166]
Specific examples of the cyanine dye represented by formula (a) that can be suitably used in the present invention include those exemplified below, and paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. And those described in paragraph numbers [0012] to [0038] of JP-A No. 2002-40638 and paragraph numbers [0012] to [0023] of JP-A No. 2002-23360.
[0167]
Embedded image

[0168]
Embedded image

[0169]
Embedded image

[0170]
Examples of infrared absorbers other than those described above are dyes having a plurality of chromophores described in JP-A No. 2001-242613, JP-A No. 2002-97384, and US Pat. No. 6,124,425. A dye in which a chromophore is covalently linked to a polymer compound, an anionic dye described in US Pat. No. 6,248,893, and surface orientation described in JP-A-2001-347765 A dye having a functional group can be suitably used.
[0171]
Examples of pigments used as infrared absorbers in the present invention include commercially available pigments and Color Index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technical Association, published in 1977), “Latest Pigment Applied Technology”. (CMC Publishing, published in 1986) and “Printing Ink Technology”, published by CMC Publishing, published in 1984).
[0172]
Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.
[0173]
These pigments may be used without surface treatment, or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Application of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.
[0174]
The particle size of the pigment is preferably in the range of 0.01 to 10 μm, more preferably in the range of 0.05 to 1 μm, and particularly preferably in the range of 0.1 to 1 μm. When the particle size of the pigment is less than 0.01 μm, it may be unfavorable in terms of stability of the dispersion in the image recording layer coating solution. There may not be.
[0175]
As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).
[0176]
These pigments or dyes are 0.01 to 50% by mass, preferably 0.1 to 10% by mass, particularly preferably 0.5 to 10% by mass, based on the total solid content constituting the recording layer. In this case, it is particularly preferably added at a ratio of 0.1 to 10% by mass. If the addition amount of the pigment or dye is less than 0.01% by mass, the sensitivity tends to be low. If the addition amount exceeds 50% by mass, the uniformity of the recording layer increases as the blending amount increases. There is a risk of adversely affecting durability. In addition, the dye or pigment used may be a single compound or a mixture of two or more compounds, and dyes or pigments having different absorption wavelengths are used in combination in order to cope with an exposure machine having a plurality of wavelengths. It is also preferably performed.
[0177]
(C) Other ingredients
In the composition for an image recording layer, if necessary, cyclic acid anhydrides, phenols, organic acids for enhancing sensitivity; as print-out agents and image colorants for obtaining a visible image immediately after exposure; Dyes, other fillers, and the like.
[0178]
As cyclic acid anhydrides, as described in US Pat. No. 4,115,128, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy-Δ 4 -tetrahydrophthalic anhydride Acid, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride, and the like.
As phenols, bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 4,4 ', 4 "-Trihydroxy-triphenylmethane, 4,4 ', 3", 4 "-tetrahydroxy-3,5,3', 5'-tetramethyltriphenylmethane and the like.
[0179]
Examples of organic acids include sulfonic acids, sulfinic acids, alkylsulfuric acids, phosphonic acids, phosphinic acids, phosphoric esters, and carbonic acids described in JP-A-60-88942 and JP-A-2-96755. Specific examples include acids such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfuric acid, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid. Acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 1,4-cyclohexene-2,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid Etc.
The proportion of the cyclic acid anhydrides, phenols, and organic acids in the image recording layer composition is preferably 0.05 to 15% by mass, and more preferably 0.1 to 5% by mass.
[0180]
Examples of the print-out agent for obtaining a visible image immediately after exposure include a combination of a photosensitive compound that releases an acid by exposure and an organic dye that forms a salt with the acid to change the color tone.
A photosensitive compound that releases an acid upon exposure is a photodecomposition product of a compound that undergoes photolysis to generate an acidic substance. For example, o-naphthoquinonediazide-4-sulfonic acid halogenide described in JP-A-50-36209; trihalomethyl-2-bilone and trihalomethyl-s described in JP-A-53-36223 -Triazine; various o-naphthoquinonediazide compounds described in JP-A-55-62444; 2-trihalomethyl-5-aryl-1,3 described in JP-A-55-77742 4-oxadiazole compounds; diazonium salts and the like.
These compounds can be used individually or in mixture, and the addition amount thereof is preferably in the range of 0.3 to 15% by mass with respect to the total mass of the composition.
[0181]
The organic dye that changes its color tone by forming a salt with an acid is an organic dye that changes its color tone by interacting with the photosensitive compound.
As such organic dyes, diphenylmethane, triarylmethane, thiazine, oxazine, phenazine, xanthene, anthraquinone, iminonaphthoquinone, and azomethine dyes can be used.
[0182]
Specifically, for example, brilliant green, eosin, ethyl violet, erythrosine B, methyl green, crystal violet, basic fuchsin, phenolphthalein, 1,3-diphenyltriazine, alizarin red S, thymolphthalein, methyl violet 2B, Quinardine red, rose bengal, thymol sulfophthalein, xylenol blue, methyl orange, orange IV, diphenylthiocarbazone, 2,7-dichlorofluorescein, paramethyl red, congo red, benzopurpurin 4B, α-naphthyl red, Nile Blue 2B, Nile Blue A, Phenacetalin, Methyl Violet, Malachite Green, Parafuchsin, Oil Blue # 603 (manufactured by Orient Chemical Co., Ltd.), O LePink # 312 [manufactured by Orient Chemical Co., Ltd.], Oil Red 5B [manufactured by Orient Chemical Industry Co., Ltd.], Oil Scarlet # 308 [manufactured by Orient Chemical Co., Ltd.], Oil Red OG [Orient Chemical Co., Ltd.] , Oil Red RR [Orient Chemical Co., Ltd.], Oil Green # 502 [Orient Chemical Co., Ltd.], Spiron Red BEH Special [Hodogaya Chemical Co., Ltd.], Victoria Pure Blue BOH [Ho Manufactured by Tsuchiya Chemical Industry Co., Ltd.], patent pure blue (manufactured by Sumitomo Mikuni Chemical Industry Co., Ltd.), Sudan Blue II (manufactured by BASF), m-cresol purple, cresol red, rhodamine B, rhodamine 6G, first acid Violet R, sulforhodamine B, auramine, 4-p-diethylamino Phenyliminonaphthoquinone, 2-carboxyanilino-4-p-diethylaminophenyliminonaphthoquinone, 2-carbostearylamino-4-p-dihydrooxyethyl-amino-phenyliminonaphthoquinone, p-methoxybenzoyl-p'-diethylamino-o '-Methylphenyliminoacetanilide, cyano-p-diethylaminophenyliminoacetanilide, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4-p-diethylaminophenylimino- 5-pyrazolone is mentioned.
[0183]
Particularly preferred organic dyes are triarylmethane dyes. Of the triarylmethane dyes, those having a sulfonic acid compound as a counter anion as described in JP-A-62-2932471 and JP-A-296921 are particularly useful.
These dyes can be used alone or in combination, and the addition amount is preferably 0.3 to 15% by mass relative to the total mass of the image recording layer composition. Further, if necessary, it can be used in combination with other dyes and pigments, and the amount used is 70% by mass or less, more preferably 50% by mass or less, based on the total mass of the dye and pigment.
[0184]
In the image recording layer composition, various resins having a hydrophobic group for improving the ink inking property of the image, such as octylphenol-formaldehyde resin, t-butylphenol-formaldehyde resin, t-butylphenol-benzaldehyde resin, rosin Modified novolak resins, o-naphthoquinone diazide sulfonic acid esters of these modified novolak resins, etc .; plasticizers for improving the flexibility of the coating film, such as dibutyl phthalate, dioctyl phthalate, butyl glycolate, tricresyl phosphate, Various additives such as dioctyl adipate can be contained according to various purposes. These addition amounts are preferably in the range of 0.01 to 30% by mass with respect to the total mass of the composition.
[0185]
In the composition, a known resin for further improving the abrasion resistance of the film can be contained. Examples of these resins include polyvinyl acetal resin, polyurethane resin, epoxy resin, vinyl chloride resin, nylon, polyester resin, and acrylic resin. These can be used alone or in combination. The addition amount is preferably in the range of 2 to 40% by mass with respect to the total mass of the composition.
[0186]
In the composition, in order to widen the development latitude, nonionic surfactants such as those described in JP-A Nos. 62-251740 and 4-68355, JP-A No. 59-121044 are disclosed. Amphoteric surfactants as described in JP-A-4-13149 and JP-A-4-13149 can be added.
[0187]
Specific examples of the nonionic surfactant include polyethylene glycol and its derivatives, polyethylene glycol polypropylene glycol ether derivatives, polyethylene glycol polypropylene glycol block copolymers, polyethylene glycol alkyl ethers, polyethylene glycol polypropylene glycol alkyl ethers, polyethylene Glycol alkyl phenyl ethers, polyethylene glycol fatty acid esters, polypropylene glycol fatty acid esters, polyethylene glycol alkyl amines, polyethylene glycol alkyl amino ethers, polypropylene glycol glyceryl ethers, glycerin fatty acid esters and their polyethylene oxide adducts, sorbitan fat Esters and their polyethylene oxide adducts, sorbite fatty acid esters and their polyethylene oxide adducts, pentaerythritol fatty acid esters and their polyethylene oxide adducts, glycerol boride fatty acid esters and their polyethylene oxide adducts, fatty acid alkanolamides and Its polyethylene oxide adducts, polyglycerin fatty acid esters, polyethylene oxide adducts of phytosterol, polyethylene oxide adducts of phytostanol, polyethylene oxide adducts of vegetable oil, polyethylene oxide adducts of lanolin, polyethylene of lanolin alcohol Oxide adducts, polyethylene oxide adducts of beeswax derivatives, alkylphenylforms Polyethylene oxide adducts of aldehyde condensate, a fluorine-based surfactant is an acrylic oligomer having a perfluoroalkyl group in its side chain and the like.
[0188]
Specific examples of the amphoteric surfactant include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, Amorgen K (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., N-tetradecyl-N, N-betaine type) 2-alkyl-N-carboxyethyl-N-hydroxyethyl imidazolinium betaine, Levon 15 (trade name, alkyl imidazoline series, manufactured by Sanyo Chemical Co., Ltd.).
The proportion of the nonionic surfactant and amphoteric surfactant in the image recording layer composition is preferably 0.05 to 15% by mass, more preferably 0.1 to 5% by mass.
[0189]
In the composition, a surfactant for improving the coating surface quality, for example, a fluorine-based surfactant described in JP-A No. 62-170950 can be contained.
A preferable addition amount is 0.001 to 1.0% by mass of the total composition, and more preferably 0.005 to 0.5% by mass.
[0190]
The composition may contain a yellow dye. Among these, a yellow dye having an absorbance at 417 nm of 70% or more of an absorbance at 436 nm is preferable.
[0191]
When a lithographic printing plate precursor is obtained from the image recording layer composition, it is provided as an image recording layer on the lithographic printing plate support described above. The image recording layer composition is dissolved or dispersed in a mixture of one or more of the following organic solvents, applied to a support and dried.
As the organic solvent, known solvents can be used, but those having a boiling point in the range of 40 to 200 ° C., particularly 60 to 160 ° C. are selected from the advantages in drying.
[0192]
Examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, n- or iso-propyl alcohol, n- or iso-butyl alcohol, diacetone alcohol; acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl Ketones such as amyl ketone, methyl hexyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, acetylacetone; hydrocarbons such as benzene, toluene, xylene, cyclohexane, methoxybenzene; ethyl acetate, n- or iso-propyl acetate Acetates such as n- or iso-butyl acetate, ethyl butyl acetate, hexyl acetate; methylene dichloride, ethylene dichloride, Halides such as chlorobenzene; ethers such as isopropyl ether, n-butyl ether, dioxane, dimethyldioxane, tetrahydrofuran; ethylene glycol, methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, diethyl cellosolve, cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, methoxy Methoxyethanol, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol Over monoethyl ether acetate, propylene glycol monobutyl ether, 3-methyl-3-polyhydric alcohols and their derivatives such as methoxy butanol; dimethyl sulfoxide, N, include special solvents such as N- dimethylformamide. These may be used alone or in combination. The solid content in the composition to be applied is suitably 2 to 50% by mass.
[0193]
[Manufacture of lithographic printing plate precursor]
Examples of the method for applying the composition for an image recording layer include roll coating, dip coating, air knife coating, gravure coating, gravure offset coating, hopper coating, blade coating, wire doctor coating, and spray coating. The coating amount is 0.3 to 4.0 g / m in terms of mass after drying.²Is preferred. As the coating amount decreases, the exposure amount for obtaining an image can be reduced, but the film strength decreases. As the coating amount increases, the exposure amount is required, but the photosensitive film becomes stronger and the printing durability is improved.
[0194]
The image recording layer composition coated on the support is usually dried by heated air. The heating is preferably in the range of 30 to 200 ° C, particularly 40 to 140 ° C. In addition to a method in which the drying temperature is kept constant during the drying, a method in which the drying temperature is increased stepwise can be implemented. Also, good results may be obtained by dehumidifying the dry air. The heated air is preferably supplied at a rate of 0.1 to 30 m / second, particularly 0.5 to 20 m / second, with respect to the coated surface.
[0195]
<Back coat>
A back coat is provided on the back surface of the support as necessary. As such a back coat, an organic polymer compound described in JP-A-5-45885 and an organic metal compound or inorganic metal compound described in JP-A-6-35174 are hydrolyzed and polycondensed. A coating layer made of the obtained metal oxide is preferably used. Of these coating layers, Si (OCH_Three)_FourSi (OC₂H_Five)_Four, Si (OC_ThreeH₇)_Four, Si (OC_FourH₉)_FourA silicon alkoxy compound such as the above is inexpensive and easily available, and a metal oxide coating layer obtained therefrom is particularly preferred because of its excellent developer resistance.
[0196]
[Manufacture of lithographic printing plates]
<Exposure>
The lithographic printing plate precursor produced as described above is usually subjected to image exposure and development processing. As an actinic ray light source used for image exposure, a light source having an emission wavelength in the near infrared to infrared region is preferable, and a solid laser or a semiconductor laser is particularly preferable.
[0197]
<Developer>
The developer suitably used for the development processing of the lithographic printing plate precursor according to the invention is a developer having a pH of 9.0 to 13.5, preferably a pH of 10.0 to 13.2. As the developer (hereinafter referred to as “developer” including replenisher), a conventionally known alkaline aqueous solution can be used.
For example, sodium silicate, potassium silicate, tribasic sodium phosphate, tribasic potassium phosphate, tribasic ammonium phosphate, dibasic sodium phosphate, dibasic potassium phosphate, dibasic ammonium phosphate, sodium carbonate, carbonic acid Inorganic alkali salts such as potassium, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium borate, potassium borate, ammonium borate, sodium hydroxide, ammonium hydroxide, potassium hydroxide and lithium hydroxide Can be mentioned.
[0198]
Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also included.
These alkaline aqueous solutions may be used individually by 1 type, and may use 2 or more types together.
[0199]
Among the above alkaline aqueous solutions, it is preferable to use a developer having a pH of 9.0 to 13.5, which contains substantially no alkali metal silicate and contains a non-reducing sugar and a base. When this developer (so-called “non-silicate developer”) is used, it is possible to prevent the formation of scum and sludge during development, so that the stability of the developer is greatly improved. Further, the surface of the image recording layer is not deteriorated, and the image recording layer can be maintained in a better state.
[0200]
This developer preferably contains at least one non-reducing sugar and at least one base as main components, and has a pH of 9.0 to 13.5.
Non-reducing sugars are sugars that do not have free aldehyde groups and ketone groups and do not exhibit reducing properties. Specifically, it is classified into trehalose-type oligosaccharides in which reducing groups are bonded to each other, glycosides in which reducing groups of saccharides and non-saccharides are combined, and sugar alcohols reduced by hydrogenation of saccharides, both of which are preferably used. .
Examples of trehalose type oligosaccharides include saccharose and trehalose.
Examples of glycosides include alkyl glycosides, phenol glycosides, and mustard oil glycosides.
Examples of the sugar alcohol include D, L-arabit, rebit, xylit, D, L-sorbit, D, L-mannit, D, L-exit, D, L-talit, zulsicit and allozulcit.
[0201]
As non-reducing sugars, maltitol obtained by hydrogenation of disaccharides and reduced form (reduced candy) obtained by hydrogenation of oligosaccharides are also preferably used.
[0202]
Among them, particularly preferred non-reducing sugars are sugar alcohol, saccharose, and reduced water candy. Particularly, D-sorbitol, saccharose, and reduced water candy are preferable because they have a buffering action in an appropriate pH region and are inexpensive.
These non-reducing sugars can be used alone or in combination of two or more thereof, and the proportion of the non-reducing sugar in the developer is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass. If the concentration is too low, sufficient buffering action may not be obtained. If the concentration is too high, it is difficult to achieve high concentration, and there is a problem of cost increase. When a reducing sugar is used in combination with a base, there is a problem that the color changes to brown over time, the pH gradually decreases, and thus developability decreases.
[0203]
A conventionally known alkaline agent can be used as the base to be combined with the non-reducing sugar. For example, sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, sodium carbonate, potassium carbonate, Examples include inorganic alkali agents such as ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium borate, potassium borate, and ammonium borate.
Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also included.
These alkali agents are used alone or in combination of two or more.
[0204]
Of these, sodium hydroxide and potassium hydroxide are preferred. The reason is that the pH can be adjusted in a wide pH range by adjusting these amounts relative to the non-reducing sugar. Further, trisodium phosphate, tripotassium phosphate, sodium carbonate, potassium carbonate and the like are preferable because they themselves have a buffering action.
These alkali agents are added so that the pH of the developer is in the range of 9.0 to 13.5, and the addition amount is determined by the desired pH and the type and addition amount of the non-reducing sugar. The range is 10.0 to 13.2.
[0205]
Further, an alkaline buffer composed of a weak acid other than sugars and a strong base can be used in combination with the developer. As the weak acid used as such a buffer, one having a dissociation constant (pKa) of 10.0 to 13.2 is preferable.
Such a weak acid can be selected from those described in “IONISATION CONSTANTS OF ORGANIC ACIDS IN AQUEOUS SOLUTION” issued by Pergamon Press.
[0206]
For example, alcohols such as 2,2,3,3-tetrafluoropropanol-1 (pKa 12.74), trifluoroethanol (12.37), trichloroethanol (12.24), pyridine-2-aldehyde ( 12.68), aldehydes such as pyridine-4-aldehyde (12.05), salicylic acid (13.0), 3-hydroxy-2-naphthoic acid (12.84), catechol (12. 6), gallic acid (12.4), sulfosalicylic acid (11.7), 3,4-dihydroxysulfonic acid (12.2), 3,4-dihydroxybenzoic acid (11.94), 1 2,4-trihydroxybenzene (11.82), hydroquinone (11.56), pyrogallol (11.34), o-cresol (10.33), Compounds having a phenolic hydroxy group such as lucinol (11.27), p-cresol (10.27), m-cresol (10.09), 2-butanone oxime (12.45), acetoxime ( 12.42), 1,2-cycloheptanedione dioxime (12.3), 2-hydroxybenzaldehyde oxime (12.10), dimethylglyoxime (11.9), ethanediamide dioxime (same as above) 11.37), oximes such as acetophenone oxime (11.35), adenosine (12.56), inosine (12.5), guanine (12.3), cytosine (12.2), In addition to nucleic acid-related substances such as hypoxanthine (12.1) and xanthine (11.9), in addition to diethylaminomethylphosphonic acid (12.3) ), 1-amino-3,3,3-trifluorobenzoic acid (12.29), isopropylidene diphosphonic acid (12.10), 1,1-ethylidene diphosphonic acid (11.54), 1-hydroxy 1,1-ethylidene diphosphonate (11.52), benzimidazole (12.86), thiobenzamide (12.8), picoline thioamide (12.55), barbituric acid (12) And weak acids such as .5).
[0207]
Of these weak acids, sulfosalicylic acid and salicylic acid are preferred. As the base to be combined with these weak acids, sodium hydroxide, ammonium hydroxide, potassium hydroxide and lithium hydroxide are preferably used. These alkali agents are used alone or in combination of two or more. The above various alkali agents are used by adjusting the pH within a preferable range depending on the concentration and combination.
[0208]
To the developer, an alkylene oxide addition compound, a surfactant, an organic solvent, and the like can be added as necessary for the purpose of promoting developability, dispersing development residue, and improving the ink affinity of the printing plate image area.
Examples of the alkylene oxide addition compound include polyoxyethylene sorbitan, polyoxyethylene sorbitol, polyoxyethylene glycerin, polyoxyethylene triethanolamine and the like.
Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants.
[0209]
Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan Fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, Polyglycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acids Ethanol amides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, nonionic surfactants such as trialkyl amine oxides;
[0210]
Fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts, dialkylsulfosuccinic acid ester salts, linear alkylbenzenesulfonic acid salts, branched alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts, alkylphenoxypolyoxyethylenepropyl Sulfonates, polyoxyethylene alkylsulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, sulfate esters of fatty acid alkyl esters Salts, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl esters Nyl ether sulfate ester salt, polyoxyethylene styryl phenyl ether sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, polyoxyethylene alkyl phenyl ether phosphate ester salt, styrene / maleic anhydride copolymer Anionic surfactants such as partial saponified products of olefins, partial saponified products of olefin / maleic anhydride copolymers, naphthalene sulfonate formalin condensates;
[0211]
Cationic surfactants such as alkylamine salts, quaternary ammonium salts such as tetrabutylammonium bromide, polyoxyethylene alkylamine salts, polyethylene polyamine derivatives;
Examples include amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric esters, and imidazolines.
Among the surfactants exemplified above, “polyoxyethylene” can be read as “polyoxyalkylene” such as polyoxymethylene, polyoxypropylene, polyoxybutylene, and the like. Also included.
[0212]
A more preferred surfactant is a fluorosurfactant containing a perfluoroalkyl group in the molecule. Examples of the fluorosurfactant include an anionic type such as perfluoroalkyl carboxylate, perfluoroalkyl sulfonate, and perfluoroalkyl phosphate; an amphoteric type such as perfluoroalkyl betaine; a perfluoroalkyltrimethylammonium salt. Perfluoroalkylamine oxide, perfluoroalkyl ethylene oxide adduct, oligomer containing perfluoroalkyl group and hydrophilic group, oligomer containing perfluoroalkyl group and lipophilic group, perfluoroalkyl group, hydrophilic group and parent Nonionic types such as oily group-containing oligomers, perfluoroalkyl groups, and lipophilic group-containing urethanes may be mentioned.
[0213]
Said surfactant can be used individually or in combination of 2 or more types, and is added in 0.001-10 mass% in a developing solution, More preferably, it is added in 0.01-5 mass%. .
[0214]
Various development stabilizers can be used in the developer. Preferred examples include polyethylene glycol adducts of sugar alcohols, tetraalkylammonium salts such as tetrabutylammonium hydroxide, phosphonium salts such as tetrabutylphosphonium bromide and diphenyliodonium chloride described in JP-A-6-282079. An iodonium salt is mentioned.
Furthermore, anionic surfactants or amphoteric surfactants described in JP-A No. 50-51324, water-soluble cationic polymers described in JP-A No. 55-95946, JP-A No. 56- Examples thereof include water-soluble amphoteric polymer electrolytes described in Japanese Patent No. 142528.
Furthermore, an organic boron compound to which an alkylene glycol is added as described in JP-A-59-84241, and a water-soluble polyoxyethylene block polymerization type or polyoxypropylene block polymerization type as described in JP-A-60-111246. Surfactants, polyoxyethylene or polyoxypropylene-substituted alkylenediamine compounds described in JP-A-60-129750, polyethyleneglycol having a weight average molecular weight of 300 or more described in JP-A-61-215554, Fluorine-containing surfactant having a cationic group disclosed in JP-A-63-175858, water-soluble ethylene oxide addition compound obtained by adding 4 mol or more of ethylene oxide to acid or alcohol disclosed in JP-A-2-39157 and water-soluble Examples include polyalkylene compounds It is.
[0215]
As the organic solvent, those having a solubility in water of about 10% by mass or less are suitable, and preferably selected from those having 5% by mass or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenyl-1-propanol, 4-phenyl-1-butanol, 4-phenyl-2-butanol, 2-phenyl-1-butanol, 2-phenoxyethanol, 2- Benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol and 4-methylcyclohexanol, N-phenylethanol Examples thereof include amines and N-phenyldiethanolamine.
[0216]
Content of the organic solvent is 0.1-5 mass% with respect to the total mass of a use liquid. The amount used is closely related to the amount of surfactant used, and it is preferable to increase the amount of surfactant as the amount of organic solvent increases. This is because the amount of the surfactant is small, and when the amount of the organic solvent is large, the organic solvent is not completely dissolved, and therefore it is impossible to expect good developability.
[0217]
A reducing agent can be further added to the developer. This is to prevent smearing of the printing plate. Preferred organic reducing agents include phenolic compounds such as thiosalicylic acid, hydroquinone, metol, methoxyquinone, resorcin, 2-methylresorcin, and amine compounds such as phenylenediamine and phenylhydrazine. More preferred inorganic reducing agents include sodium, potassium and ammonium salts of inorganic acids such as sulfurous acid, bisulfite, phosphorous acid, phosphorous acid, dihydrogen phosphite, thiosulfuric acid and dithionite. A salt etc. can be mentioned.
Among these reducing agents, sulfites are particularly excellent in the antifouling effect. These reducing agents are preferably contained in the range of 0.05 to 5% by mass with respect to the developer at the time of use.
[0218]
An organic carboxylic acid can also be added to the developer. Preferred organic carboxylic acids are aliphatic carboxylic acids and aromatic carboxylic acids having 6 to 20 carbon atoms. Specific examples of the aliphatic carboxylic acid include caproic acid, enanthylic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred are alkanoic acids having 8 to 12 carbon atoms. . Further, it may be an unsaturated fatty acid having a double bond in the carbon chain or a branched carbon chain. Aromatic carboxylic acids are compounds in which a carboxy group is substituted on a benzene ring, naphthalene ring, anthracene ring, etc., and specifically include o-chlorobenzoic acid, p-chlorobenzoic acid, o-hydroxybenzoic acid, p- Hydroxybenzoic acid, o-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydrobenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3, There are 5-dihydroxybenzoic acid, gallic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-naphthoic acid, 2-naphthoic acid and the like. Naphthoic acid is particularly effective.
[0219]
The aliphatic and aromatic carboxylic acids are preferably used as sodium salts, potassium salts or ammonium salts in order to enhance water solubility. The content of the organic carboxylic acid in the developer used in the present invention is not particularly limited, but if it is less than 0.1% by mass, the effect is not sufficient, and if it is 10% by mass or more, the effect cannot be further improved. , Dissolution may be hindered when another additive is used in combination. Therefore, a preferable addition amount is 0.1 to 10% by mass, and more preferably 0.5 to 4% by mass with respect to the developing solution at the time of use.
[0220]
The developer may further contain a preservative, a colorant, a thickener, an antifoaming agent, a hard water softening agent, and the like, if necessary.
Examples of water softeners include polyphosphoric acid and its sodium, potassium and ammonium salts, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, 1,2-diaminocyclohexanetetra Aminopolycarboxylic acids such as acetic acid and 1,3-diamino-2-propanoltetraacetic acid and their sodium, potassium and ammonium salts, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylene Phosphonic acid), triethylenetetramine hexa (methylenephosphonic acid), hydroxyethylethylenediaminetri (methylenephosphonic acid), 1- Dorokishitaen 1,1-diphosphonic acid and their sodium salts, potassium salts and ammonium salts.
[0221]
The optimum value of such a hard water softening agent varies depending on its chelation and the hardness and amount of hard water used. If a general amount of use is shown, 0.01 to 5% by mass in the developer at the time of use, More preferably, it is the range of 0.01-0.5 mass%. If the addition amount is too small, the purpose of the addition is not sufficiently achieved, and if it is too large, there may be an adverse effect on the image area such as color loss. The remaining component of the developer is water. It is advantageous in terms of transportation that the developer is a concentrated solution having a water content less than that in use and is diluted with water when in use. In this case, the degree of concentration is appropriate such that each component does not cause separation or precipitation.
[0222]
The above-mentioned various surfactants and organic solvents can be added to the developer as necessary for the purpose of promoting developability, dispersing development residue, and improving the ink affinity of the printing plate image area.
[0223]
<Post-processing>
The lithographic printing plate obtained by developing with the above-described developer is subjected to post-treatment with washing water, a rinse solution containing a surfactant, a finisher mainly composed of gum arabic, a starch derivative, and a protective gum solution. Applied. These processes can be used in various combinations for the post-processing of the lithographic printing plate.
[0224]
<Automatic processor>
In recent years, automatic developing machines for lithographic printing plate precursors have been widely used in the stencil and printing industries in order to rationalize and standardize plate making operations. This automatic developing machine generally consists of a developing unit and a post-processing unit, and includes a device for transporting a lithographic printing plate precursor, each processing solution tank and a spray device, while horizontally transporting the exposed lithographic printing plate precursor, Each processing liquid pumped up by a pump is sprayed from a spray nozzle to develop and post-process. In addition, recently, a lithographic printing plate precursor has been immersed in a processing liquid tank filled with a processing liquid with a guide roll in the liquid and transported, and a fixed amount of a small amount of washing water is supplied to the plate surface after development. A method is also known in which the waste water is reused as dilution water for the developer stock solution.
In such automatic processing, each processing solution can be processed while being replenished with each replenisher according to the processing amount, operating time, and the like. In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.
The planographic printing plate obtained by such processing is installed in a printing machine and used for printing a large number of sheets.
[0225]
【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
(Lithographic printing plate support A)
Various surface treatments of the following (a) to (g) were continuously performed on an aluminum plate (JIS A1050 material) having a thickness of 0.3 mm to obtain a support A for a lithographic printing plate. After each treatment and water washing, the liquid was drained with a nip roller.
[0226]
(A) Alkali etching treatment
The aluminum plate obtained above was subjected to an etching process for 10 seconds using an aqueous solution having a caustic soda concentration of 30 g / L, an aluminum ion concentration of 10 g / L, and a temperature of 60 ° C., and the aluminum plate was 0.5 g / m.²Dissolved. Then, water washing by spraying was performed.
[0227]
(B) Desmut treatment
A desmut treatment by spraying was performed with an aqueous solution of nitric acid having a nitric acid concentration of 12 g / L at a temperature of 30 ° C. (containing 10 g / L of aluminum ions), followed by washing with water by spraying.
[0228]
(C) Electrochemical roughening treatment
An electrochemical roughening treatment was continuously performed using an AC voltage of 50 Hz. The electrolytic solution at this time was a hydrochloric acid 15 g / L aqueous solution (containing 10 g / L of aluminum ions) at a temperature of 30 ° C. The AC power supply waveform was a sine wave, and an electrochemical roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 3 was used. 5% of the current flowing from the power source was shunted to the auxiliary anode.
The current density is 16 A / dm at the peak current value.²The amount of electricity is 400 C / dm as the total amount of electricity when the aluminum plate is the anode.²Met.
Then, water washing by spraying was performed.
[0229]
(D) Alkali etching treatment
The aluminum plate was subjected to an etching process by spraying at 35 ° C. for 10 seconds using an aqueous solution having a caustic soda concentration of 36 g / L and an aluminum ion concentration of 10 g / L.²Dissolve and remove the smut component mainly composed of aluminum hydroxide that was generated when the electrochemical roughening treatment was performed using the alternating current of the previous stage, and the edge portion of the generated pit was dissolved Made smooth. Then, water washing by spraying was performed.
[0230]
(E) Desmut treatment
A desmutting treatment by spraying was performed for 10 seconds with a 15% by weight aqueous solution of sulfuric acid at a temperature of 30 ° C. (containing 10% by weight of aluminum ions), followed by washing with water by spraying.
[0231]
(F) Anodizing treatment
Anodization was performed using an anodizing apparatus using direct current electrolysis to obtain a lithographic printing plate support. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. The electrolyte solutions all had a sulfuric acid concentration of 10% by mass (containing 5.0% by mass of aluminum ions) and a temperature of 20 ° C. Current density is 6A / dm²Met. Then, water washing by spraying was performed. The final oxide film amount is 2.5 g / m²Met.
Surface roughness R of lithographic printing plate support after anodizing treatment_aWas 0.44 μm.
[0232]
(G) Alkali metal silicate treatment
The lithographic printing plate support after the anodizing treatment is immersed in a treatment tank of a 1.0 mass% aqueous solution of sodium silicate No. 3 at a temperature of 20 ° C. for 10 seconds, whereby alkali metal silicate treatment (silicate treatment) ) Then, the water washing by the spray using well water was performed.
[0233]
(Support for lithographic printing plate B)
In the above (c), the current density is 12 A / dm.², The amount of electricity is 300C / dm²Except for the above, a lithographic printing plate support B was obtained in the same manner as for the lithographic printing plate support A. Surface roughness R of lithographic printing plate support after anodizing treatment_aWas 0.34 μm.
[0234]
(Support for planographic printing plate C)
In the above (c), the current density is 24 A / dm.², The amount of electricity is 600C / dm²A lithographic printing plate support C was obtained in the same manner as for the lithographic printing plate support A except that. Surface roughness R of lithographic printing plate support after anodizing treatment_aWas 0.34 μm.
[0235]
(Support D for lithographic printing plate)
In the above (c), electrochemical surface roughening treatment was performed using the electrolytic cell shown in FIG. 2, and in the above (d), the temperature of the aqueous caustic soda solution was changed to 30 ° C. A lithographic printing plate support D was obtained in the same manner as for the body A.
[0236]
(Support for planographic printing plate E)
In the above (c), electrochemical surface roughening treatment was performed using the electrolytic cell shown in FIG. 2, and in the above (d), the temperature of the aqueous caustic soda solution was changed to 45 ° C. A lithographic printing plate support E was obtained in the same manner as for the body A.
[0237]
(Flat plate printing plate support F)
In the above (g), a lithographic printing plate support F was obtained in the same manner as the lithographic printing plate support A except that the concentration of No. 3 sodium silicate aqueous solution was 0.2% by mass.
[0238]
(Support G for lithographic printing plate)
The lithographic printing plate support is the same as the lithographic printing plate support A except that the concentration of No. 3 sodium silicate aqueous solution is 2.5 mass% and the temperature is 50 ° C. G was obtained.
[0239]
(Support for lithographic printing plate H)
In the above (c), the current density is 12 A / dm.², The amount of electricity is 50C / dm²Except for the above, a lithographic printing plate support H was obtained in the same manner as for the lithographic printing plate support A. Surface roughness R of lithographic printing plate support after anodizing treatment_aWas 0.24 μm.
[0240]
(Lithographic printing plate support I)
The lithographic printing plate support is the same as the lithographic printing plate support A except that the concentration of No. 3 sodium silicate aqueous solution is 2.5% by mass and the temperature is 80 ° C. I was obtained.
[0241]
(Support for lithographic printing plate J)
A lithographic printing plate support J was obtained in the same manner as for the lithographic printing plate support A except that the above (g) was not performed.
[0242]
(Support for lithographic printing plate K)
A lithographic printing plate support K was obtained in the same manner as in the lithographic printing plate support A except that the temperature of the aqueous caustic soda solution was 60 ° C.
[0243]
(Lithographic printing plate support L)
Instead of the above (a) and (b), the lithographic printing plate support is the same as the lithographic printing plate support A except that the following (h), (i) and (j) are sequentially performed. K was obtained. Surface roughness R of lithographic printing plate support after anodizing treatment_aWas 0.55 μm.
[0244]
(H) Mechanical roughening treatment
Using the apparatus shown in FIG. 1, a roller-like nylon brush rotating while supplying a suspension (specific gravity 1.12) of an abrasive (silica sand) and water as an abrasive slurry to the surface of an aluminum plate. Mechanical roughening treatment was performed. The average particle size of the abrasive was 8 μm, and the maximum particle size was 50 μm. 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 tube having a diameter of 300 mm. Three rotating brushes were 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 7 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 rotation speed of the brush was 200 rpm.
[0245]
(I) Alkaline etching treatment
The aluminum plate obtained above was subjected to an etching process for 10 seconds using an aqueous solution having a caustic soda concentration of 26 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C., and the aluminum plate was 6 g / m 2.²Dissolved. Then, water washing by spraying was performed.
[0246]
(J) Desmut processing
A desmut treatment was performed by spraying with an aqueous solution of nitric acid having a concentration of 1% by mass (containing 0.5% by mass of aluminum ions) at a temperature of 30 ° C., followed by washing with water by spraying.
[0247]
(Lithographic printing plate support M)
In the above (h), instead of silica sand, a pumice having an average particle size of 50 μm and a maximum particle size of 150 μm was used as the abrasive, the brush rotation speed was 250 rpm, and in (i), the amount of dissolved aluminum was 8g / m²In the same manner as the lithographic printing plate support L except that the following (k), (l) and (m) were carried out instead of the above (c), (d) and (e) A printing plate support M was obtained. Surface roughness R of lithographic printing plate support after anodizing treatment_aWas 0.55 μm.
[0248]
(K) Electrochemical roughening treatment
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a nitric acid 10.5 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 50 ° C. The AC power supply waveform is the waveform shown in FIG. 5, the time TP until the current value reaches a 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. 4 was used. 5% of the current flowing from the power source was shunted to the auxiliary anode.
The current density is 30 A / dm at the peak current value.²The amount of electricity is 220 C / dm in terms of the total amount of electricity when the aluminum plate is the anode.²Met.
Then, water washing by spraying was performed.
[0249]
(L) Alkali etching treatment
The aluminum plate was etched at 60 ° C. using an aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, and the aluminum plate was 1.0 g / m.²Dissolve and remove the smut component mainly composed of aluminum hydroxide that was generated when the electrochemical roughening treatment was performed using the alternating current of the previous stage, and the edge portion of the generated pit was dissolved Made smooth. Then, water washing by spraying was performed.
[0250]
(M) Desmut treatment
The desmutting treatment was performed by spraying with a 15% by weight aqueous solution of sulfuric acid having a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washing with water by spraying.
[0251]
(Lithographic printing plate support N)
Without performing the above (h), in the above (l), the temperature of the caustic soda aqueous solution was set to 32 ° C., and the aluminum dissolution amount was 0.2 g / m 2.²A lithographic printing plate support N was obtained in the same manner as for the lithographic printing plate support M except that. Surface roughness R of lithographic printing plate support after anodizing treatment_aWas 0.25 μm.
[0252]
2. Measurement of surface shape of lithographic printing plate support
With respect to the pits on the surface of the lithographic printing plate support obtained above, the following measurements (1) to (3) were performed.
The results are shown in Table 1. In Table 1, “-” indicates that there was no pit having the corresponding average opening diameter.
(1) Average opening diameter of large pits
Using SEM, the surface of the support was photographed at a magnification of 1000 times from directly above, and 50 large pits with a ring around the pit were extracted from the obtained SEM photograph, and the diameter was read to obtain the opening diameter. The average opening diameter was calculated.
[0253]
(2) Average opening diameter of small pits
The surface of the support was photographed at a magnification of 50000 times from directly above using a high resolution SEM, 50 small pits were extracted from the obtained SEM photograph, the diameter was read and used as the opening diameter, and the average opening diameter was calculated. .
[0254]
(3) Average ratio of depth to small pit opening diameter
The average ratio of the depth to the opening diameter of the small pits was obtained by photographing the fractured surface of the support at a magnification of 50000 times using a high-resolution SEM, and 20 small pits having an opening diameter of 0.8 μm or less in the obtained SEM photograph Each sample was extracted, the aperture diameter and depth were read, the ratio was determined, and the average value was calculated.
[0255]
3. Calculation of surface shape factor of lithographic printing plate support
About the surface of the lithographic printing plate support obtained above, ΔS⁵⁰Asked.
The results are shown in Table 1.
[0256]
(1) Surface shape measurement by atomic force microscope
The surface shape was measured with an atomic force microscope (SP13700, manufactured by Seiko Denshi Kogyo Co., Ltd.) to obtain three-dimensional data. A specific procedure will be described below.
The planographic 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 it reaches the region where the atomic force is applied, it moves in the XY direction. 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 150 kHz and a spring constant of 12 to 20 N / m (AC-160TS, manufactured by Olympus Corporation) 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.
At the time of measurement, the surface of 50 μm □ was measured at 512 × 512 points. The resolution in the XY direction was 1.9 μm, the resolution in the Z direction was 1 nm, and the scan speed was 60 μm / sec.
[0257]
(2) ΔS⁵⁰Calculation
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 difference ΔS⁵⁰Is the actual area S obtained_x ⁵⁰And geometric measurement area S₀ ⁵⁰From the above, it was determined by the above formula (1).
[0258]
4). Measurement of Si atom adhesion on the surface of lithographic printing plate support
The adhesion amount of Si atoms on the surface of each lithographic printing plate support was measured by a calibration curve method using a fluorescent X-ray analyzer. The results are shown in Table 1. The values in Table 1 are corrected for the amount of Si atoms contained in the aluminum plate.
[0259]
As a standard sample for preparing a calibration curve, a sodium silicate aqueous solution containing a known amount of Si atoms was uniformly dropped into an area of 30 mmφ on an aluminum plate and then dried. The conditions for fluorescent X-ray analysis are shown below.
[0260]
X-ray fluorescence analyzer: RIX3000 manufactured by Rigaku Corporation, X-ray tube: Rh, measurement spectrum: Si-Kα, tube voltage: 50 kV, tube current: 50 mA, slit: COARSE, spectral crystal: RX4, detector: F -PC, analysis area: 30 mmφ, peak position (2θ): 144.75 deg. , Background (2θ): 140.70 deg. And 146.85 deg. Integration time: 80 seconds / sample
[0261]
5). Creating a lithographic printing plate precursor
(Examples 1-7 and Comparative Examples 1-7)
Each lithographic printing plate support obtained above is provided with a thermal positive type image recording layer as follows, and the lithographic printing of Examples 1 to 7 and Comparative Examples 1 to 7 shown in Table 1 I got the original version. Before providing the image recording layer, an undercoat layer was provided as described later.
[0262]
An undercoat solution having the following composition was applied onto a lithographic printing plate support and dried at 80 ° C. for 15 seconds to form a coating film of an undercoat layer. The coating amount after drying is 15 mg / m²Met.
[0263]
<Undercoat liquid composition>
・ The following polymer compound 0.3g
・ Methanol 100g
・ Water 1g
[0264]
Embedded image

[0265]
Furthermore, 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 1.8 g / m.²And dried to form a heat sensitive layer (thermal positive type image recording layer) to obtain a lithographic printing plate precursor.
[0266]
<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) 0.90 g
・ Ethyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (molar ratio 35/35/30) 0.10 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 (Defenser F-780F, manufactured by Dainippon Ink & Chemicals, Inc., solid content: 30% by mass) 0.0045 g (solid content conversion)
・ Fluorine-based surfactant (Defenser F-781F, manufactured by Dainippon Ink & Chemicals, Inc., solid content: 100% by mass) 0.035 g
・ Methyl ethyl ketone 12g
[0267]
Embedded image

[0268]
6). Evaluation of planographic printing plate precursors
The sensitivity of the lithographic printing plate precursor obtained above and the printing durability of the lithographic printing plate, the printing durability after the burning treatment (burning printing durability), the stain resistance and the visibility of water rising were evaluated by the following methods. .
[0269]
(1) Sensitivity
The obtained lithographic printing plate precursor was drawn into an image (image recording) using a TrendSetter manufactured by Creo, changing the beam intensity from 2 to 13 W at a drum rotation speed of 150 rpm.
Thereafter, using a PS processor 940H manufactured by Fuji Photo Film Co., Ltd., charged with either alkali developer A or B having the following composition, development was performed at a developing time of 20 seconds while maintaining the liquid temperature at 30 ° C. In Example 6, alkaline developer A was used, and in other examples and comparative examples, alkaline developer B was used. The alkaline developer A had a pH of 13.2 and the alkaline developer B had a pH of 13.3.
Sensitivity was evaluated based on the beam intensity at which the image was successfully developed without stains or coloring due to the residual film of the poorly developed image recording layer. The smaller the beam intensity, the higher the sensitivity. The results are shown in Table 1.
[0270]
<Alkali developer A composition>
・ SiO₂・ K₂O (K₂O / SiO₂= 1/1 (molar ratio)) 4.0% by mass
・ Citric acid 0.5% by mass
・ Polyethylene glycol lauryl ether (weight average molecular weight 1,000) 0.5 mass%
・ Water 95.0 mass%
[0271]
<Alkali developer B composition>
・ D-Sorbit 2.5% by mass
-Sodium hydroxide 0.85 mass%
・ Polyethylene glycol lauryl ether (weight average molecular weight 1,000) 0.5 mass%
・ Water 96.15% by mass
[0272]
(2) Printing durability
The resulting lithographic printing plate precursor was imaged using a TrendSetter manufactured by Creo at a drum rotation speed of 150 rpm and a beam intensity of 10 W.
Thereafter, using a PS processor 940H manufactured by Fuji Photo Film Co., Ltd., charged with either of the alkaline developers A and B, the liquid temperature was maintained at 30 ° C. and development was performed for 20 seconds to obtain a lithographic printing plate. . In Example 6, alkaline developer A was used, and in other examples and comparative examples, alkaline developer B was used.
The resulting lithographic printing plate was printed on a Lithrone printing machine manufactured by Komori Corporation using DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. The printing durability was evaluated based on the number of printed sheets when visually recognized. The results are shown in Table 1.
[0273]
(3) Printing durability after burning treatment
The plate surface of a lithographic printing plate obtained in the same manner as in the evaluation of printing durability was wiped with a burning surface-conditioning solution BC-3 manufactured by Fuji Photo Film Co., Ltd., and then subjected to a burning treatment at about 240 ° C. for 7 minutes. went. Then, it washed with water and processed the printing plate with the liquid which diluted the volume GU-7 made from Fuji Photo Film Co., Ltd. with water twice.
After that, as in the case of evaluation of printing durability, printing was performed using a DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. using a Lithlon printer manufactured by Komori Corporation, and the density of the solid image The printing durability after the burning treatment (burning printing durability) was evaluated by the number of printed sheets when it was visually recognized that the film started to become thinner. The results are shown in Table 1.
[0274]
(4) Dirt resistance
Using a lithographic printing plate obtained in the same manner as in the evaluation of printing durability, printing was performed with DIC-GEOS (s) red ink on a Mitsubishi diamond F2 printer (manufactured by Mitsubishi Heavy Industries). The stain on the blanket after printing 10,000 sheets was visually evaluated.
The results are shown in Table 1. The blanket was evaluated from three grades of ◯, △, and X, from the one with little dirt to the one with much dirt.
[0275]
(5) Ease of seeing the water
A lithographic printing plate obtained in the same manner as in the evaluation of printing durability is attached to a Lithlon printing machine manufactured by Komori Corporation, and the lightness of the non-image area of the printing plate is visually checked while increasing the amount of dampening water supplied. The plate inspection property (ease of seeing water rising) was evaluated based on the amount of dampening water supplied when starting to shine.
The results are shown in Table 1. From the case where the supply amount of dampening water when it began to shine to the case where it was small, the evaluation was made in three stages: ○, Δ, and ×.
[0276]
As is apparent from Table 1, the lithographic printing plate precursors (Examples 1 to 7) of the present invention have any of sensitivity, stain resistance, printing durability, and ease of seeing when the lithographic printing plate is used. Also excellent.
Further, the lithographic printing plate precursors (Examples 1 to 7) of the present invention having an image recording layer containing 30% by mass or more of novolak resin are excellent in burning printing durability in addition to the above properties.
Further, after the exposure, when developed using a developer having a pH of 9.0 to 13.5 that contains substantially no alkali metal silicate and contains a non-reducing sugar and a base (Examples 1 to 5). And 7), a lithographic printing plate excellent in all of sensitivity, stain resistance, printing durability and ease of seeing water was obtained.
[0277]
[Table 1]

[0278]
【The invention's effect】
As described above, the lithographic printing plate precursor according to the present invention is excellent in sensitivity, stain resistance, printing durability, and ease of seeing water when a lithographic printing plate is used.
[Brief description of the drawings]
FIG. 1 is a side view showing the concept of a brush graining process used for mechanical surface roughening in the production of a lithographic printing plate support used in the present invention.
FIG. 2 is a cross-sectional view showing an example of an electrolytic surface roughening treatment apparatus provided with a flat AC electrolytic cell used for producing a lithographic printing plate support used in the present invention.
FIG. 3 is a cross-sectional view showing another example of an electrolytic surface roughening treatment apparatus provided with a flat AC electrolytic cell used for producing a lithographic printing plate support used in the present invention.
FIG. 4 is a cross-sectional view showing an example of an electrolytic surface roughening treatment apparatus including a radial AC electrolytic cell used for producing a lithographic printing plate support used in the present invention.
FIG. 5 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 used in the present invention.
[Explanation of symbols]
2, 20 AC electrolytic cell
4A, 4B, 4C, 26A, 26B Main pole
6A, 6B, 14A, 14B Conveying roller
8A, 16A Introduction roller
8B, 16B Deriving roller
10, 34 Auxiliary electrolytic cell
12, 36 Auxiliary electrode
22 AC electrolytic cell body
22A opening
24 Feed roller
28A, 28B Liquid supply nozzle
30A Upstream guide roller
30B Downstream guide roller
32 Overflow tank
34A Bottom of auxiliary electrolytic cell
35 Upstream guide roller
51 Aluminum alloy plate
52, 54 Roller brush
53 Polishing slurry
55, 56, 57, 58 Support roller
100, 102, 104 Electrolytic surface roughening treatment apparatus
a Transport direction
T Transport surface
T_ac  Power supply
Th1, Th2, Th3, Th4, Th5 Thyristor
W Aluminum web
ta anode reaction time
tb cathode reaction time
tc Time until current reaches peak from 0
Ia Peak current on the anode cycle side
Ic Peak current on the cathode cycle side

Claims (2)

An image is formed by heat on a lithographic printing plate support obtained by subjecting an aluminum plate to an electrochemical surface roughening treatment using an aqueous solution containing at least hydrochloric acid, an anodizing treatment and an alkali metal silicate treatment. A lithographic printing plate precursor provided with an image recording layer capable of
In the electrochemical surface roughening treatment using the aqueous solution containing hydrochloric acid, the aluminum plate is subjected to the electrochemical surface roughening treatment while conveying the web of the aluminum plate in a substantially horizontal direction, using alternating current, the aluminum The amount of electricity with which the plate participates in the anodic reaction is 300 to 600 C / dm ² ,
The lithographic printing plate support is formed by an electrochemical surface roughening treatment using an aqueous solution containing the hydrochloric acid, and has a large pit with an average opening diameter of 2 to 10 μm and an average opening diameter of 0.05 to 0.8 μm. The surface has a grain shape with a structure superposed on the small pits, and the average ratio of the depth to the opening diameter of the small pits is 0.2 to 0.6,
For the lithographic printing plate support, using an atomic force microscope, an actual area S _x ⁵⁰ determined by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points of 50 μm □ on the surface, from biological measurement area S ₀ ⁵⁰ Prefecture, 20 to 40 percent surface area difference [Delta] S ⁵⁰ obtained by the following equation (1),
The Si atom adhesion quantity of the surface of the lithographic printing plate support is 1.0~15.0mg / m are ^two der,
Wherein the image recording layer, you containing a novolak resin more than 30 wt%, the lithographic printing plate precursor.
ΔS ⁵⁰ = (S _x ⁵⁰ −S ₀ ⁵⁰ ) / S ₀ ⁵⁰ × 100 (%) (1) After exposure to the lithographic printing plate precursor according to claim 1 , using a developer having a pH of 9.0 to 13.5 substantially containing no alkali metal silicate and containing a non-reducing sugar and a base. A method for producing a lithographic printing plate, which is developed to obtain a lithographic printing plate.

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