JP2005066829A - Support for planographic printing plate and planographic printing original plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support for a planographic printing plate used for a planographic printing original plate, which can efficiently utilize heat for forming an image, exhibit high sensitivity, excellent plate wear, excellent hydrophilic properties and small spoilage at the start of printing and can suppress generation of scumming on a non-imaging part. <P>SOLUTION: The support for the planographic printing plate is obtained by subjecting an aluminum plate to surface roughening treatment and anodic oxidation treatment. The support is characterized in that a roughening structure, wherein a middle wave structure having a mean opening diameter of 0.5 to 5 μm and a small wave structure having a mean opening diameter of 0.01 to 0.2 μm are superimposed, is formed on the surface, and inorganic compound particles having a mean long diameter which is larger than the mean surface pore size of an anodically oxidized film and is less than the mean opening diameter of a small wave structure existing on the surface exist on the anodically oxidized film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００７３】
上記式（Ｉ）中、Ｒは、炭素原子数１〜２０の直鎖のまたは分枝を有する、アルキル基、アルケニル基またはアルキニル基を表す。
炭素原子数１〜２０のアルキル基としては、例えば、メチル、エチル、プロピル、ブチル、ペンチル、ヘキシル、ヘプチル、オクチル、ノニル、デシル、ウンデシル、ドデシル、トリデシル、テトラデシル、ペンタデシル、ヘキサデシル、ヘプタデシル、オクタデシル、ノナデシル、エイコシル基が挙げられ、これらは直鎖であっても、分枝を有していてもよく、また、環状アルキル基であってもよい。
炭素原子数１〜２０のアルケニル基としては、例えば、アリル、２−ブテニル基が挙げられ、これらは直鎖であっても、分枝を有していてもよく、また、環状アルケニル基であってもよい。
炭素原子数１〜２０のアルキニル基としては、例えば、１−ペンチニル基が挙げられ、これらは直鎖であっても、分枝を有していてもよく、また、環状アルキニル基であってもよい。
【００７４】
上記式（Ｉ）で表される具体的な化合物としては、例えば、メチルグルコシド、エチルグルコシド、プロピルグルコシド、イソプロピルグルコシド、ブチルグルコシド、イソブチルグルコシド、ｎ−ヘキシルグルコシド、オクチルグルコシド、カプリルグルコシド、デシルグルコシド、２−エチルヘキシルグルコシド、２−ペンチルノニルグルコシド、２−ヘキシルデシルグルコシド、ラウリルグルコシド、ミリスチルグルコシド、ステアリルグルコシド、シクロヘキシルグルコシド、２−ブチニルグルコシドが挙げられる。これらの化合物は、配糖体の一種であるグルコシドで、ブドウ糖のヘミアセタールヒドロキシル基が他の化合物をエーテル状に結合したものであり、例えば、グルコースとアルコール類とを反応させる公知の方法により得ることができる。これらのアルキルグルコシドの一部は、ドイツＨｅｎｋｅｌ社により商品名グルコポン（ＧＬＵＣＯＰＯＮ）として市販されており、本発明ではそれを用いることができる。
【００７５】
好ましい配糖体の別の例としては、サポニン類、ルチントリハイドレート、ヘスペリジンメチルカルコン、ヘスペリジン、ナリジンハイドレート、フェノール−β−Ｄ−グルコピラノシド、サリシン、３´，５，７−メトキシ−７−ルチノシドが挙げられる。
【００７６】
糖類化合物を含有する水溶液のｐＨは、８〜１１であるのが好ましく、水酸化カリウム、硫酸、炭酸、炭酸ナトリウム、リン酸、リン酸ナトリウム等を用いて上記ｐＨ範囲に調整することができる。
【００７７】
ポリビニルホスホン酸の水溶液は、濃度が０．１〜５質量％であるのが好ましく、０．２〜２．５質量％であるのがより好ましい。浸せき温度は１０〜７０℃であるのが好ましく、３０〜６０℃であるのがより好ましい。浸せき時間は１〜２０秒であるのが好ましい。
また、スルホン酸基を有する化合物の水溶液は、濃度が０．０２〜０．２質量％であるのが好ましい。浸せき温度は６０〜１００℃であるのが好ましい。浸せき時間は１〜３００秒であるのが好ましく、１０〜１００秒であるのがより好ましい。
更に、糖類化合物の水溶液は、濃度が０．５〜１０質量％であるのが好ましい。浸せき温度は４０〜７０℃であるのが好ましい。浸せき時間は２〜３００秒であるのが好ましく、５〜３０秒であるのがより好ましい。
【００７８】
本発明では、親水性化合物を含有する水溶液として、上述したような有機化合物の水溶液のほかに、アルカリ金属ケイ酸塩水溶液、フッ化ジルコニウムカリウム（Ｋ_２ ＺｒＦ_６ ）水溶液、リン酸塩／無機フッ素化合物を含む水溶液等の無機化合物水溶液も好適に用いられる。
【００７９】
アルカリ金属ケイ酸塩水溶液処理は、好ましくは濃度が０．０１〜３０質量％、より好ましくは０．１〜１０質量％であり、２５℃でのｐＨが好ましくは１０〜１３であるアルカリ金属ケイ酸塩の水溶液に、支持体を、好ましくは３０〜１００℃、より好ましくは５０〜９０℃で、好ましくは０．５〜４０秒間、より好ましくは１〜２０秒間浸せきすることにより行う。
【００８０】
親水性表面処理に用いられるアルカリ金属ケイ酸塩は、例えば、上述したフッ素化合物及びケイ酸化合物のうちの少なくともいずれかを含有する固着処理液に用いられるアルカリ金属ケイ酸塩として列挙したものが挙げられる。
アルカリ金属ケイ酸塩の水溶液は、ｐＨを高くするために、水酸化ナトリウム、水酸化カリウム、水酸化リチウム等の水酸化物を適当量含有してもよい。中でも、水酸化ナトリウム、水酸化カリウムが好ましい。
また、アルカリ金属ケイ酸塩の水溶液は、アルカリ土類金属塩または４族（第ＩＶＢ族）金属塩を含有してもよい。アルカリ土類金属塩としては、例えば、上述したフッ素化合物及びケイ酸化合物のうちの少なくともいずれかを含有する固着処理液で例示されたアルカリ土類金属塩が挙げられる。アルカリ土類金属塩および４族（第ＩＶＢ族）金属塩は、単独でまたは２種以上組み合わせて用いられる。
【００８１】
フッ化ジルコニウムカリウム水溶液処理は、好ましくは濃度が０．１〜１０質量％、より好ましくは０．５〜２質量％のフッ化ジルコニウムカリウムの水溶液に、支持体を、好ましくは３０〜８０℃で、好ましくは６０〜１８０秒間浸せきすることにより行う。
【００８２】
リン酸塩／無機フッ素化合物処理は、好ましくはリン酸塩化合物濃度が５〜２０質量％、無機フッ素化合物濃度が０．０１〜１質量％であり、好ましくはｐＨが３〜５の水溶液に、支持体を、好ましくは２０〜１００℃、より好ましくは４０〜８０℃で、好ましくは２〜３００秒間、より好ましくは５〜３０秒間浸せきすることにより行う。
【００８３】
本発明に用いられるリン酸塩としては、例えば、アルカリ金属、アルカリ土類金属等の金属のリン酸塩が挙げられる。
具体的には、例えば、リン酸亜鉛、リン酸アルミニウム、リン酸アンモニウム、リン酸水素二アンモニウム、リン酸二水素アンモニウム、リン酸一アンモニウム、リン酸一カリウム、リン酸一ナトリウム、リン酸二水素カリウム、リン酸水素二カリウム、リン酸カルシウム、リン酸水素アンモニウムナトリウム、リン酸水素マグネシウム、リン酸マグネシウム、リン酸第一鉄、リン酸第二鉄、リン酸二水素ナトリウム、リン酸ナトリウム、リン酸水素二ナトリウム、リン酸鉛、リン酸二アンモニウム、リン酸二水素カルシウム、リン酸リチウム、リンタングステン酸、リンタングステン酸アンモニウム、リンタングステン酸ナトリウム、リンモリブデン酸アンモニウム、リンモリブデン酸ナトリウム；亜リン酸ナトリウム、トリポリリン酸ナトリウム、ピロリン酸ナトリウムが挙げられる。中でも、リン酸二水素ナトリウム、リン酸水素二ナトリウム、リン酸二水素カリウム、リン酸水素二カリウムが好ましい。
【００８４】
また、親水性表面処理に用いられる無機フッ素化合物としては、金属フッ化物が好適に挙げられる。
具体的には、例えば、上述したフッ素化合物及びケイ酸化合物のうちの少なくともいずれかを含有する封孔処理液に用いられるフッ素化合物として列挙したものが挙げられる。
リン酸塩／無機フッ素化合物処理に用いられる水溶液は、リン酸塩および無機フッ素化合物をそれぞれ１種または２種以上含有することができる。
支持体は、これらの親水性化合物を含有する水溶液へ浸せきした後には、水等によって洗浄され、乾燥される。
【００８５】
［下塗層］
上記のようにして得られた本発明のアルミニウム支持体（基板）上に、赤外線レーザー露光により書き込み可能な記録層（以下、感熱層ともいう）を設ける前に、必要に応じて、例えば、ホウ酸亜鉛等の水溶性金属塩のような無機下塗層や、有機下塗層を設けてもよい。
【００８６】
有機下塗層に用いられる有機化合物としては、例えば、カルボキシメチルセルロース；デキストリン；アラビアガム；スルホン酸基を側鎖に有する重合体および共重合体；ポリアクリル酸；２−アミノエチルホスホン酸等のアミノ基を有するホスホン酸類；置換基を有していてもよいフェニルホスホン酸、ナフチルホスホン酸、アルキルホスホン酸、グリセロホスホン酸、メチレンジホスホン酸、エチレンジホスホン酸等の有機ホスホン酸；置換基を有していてもよいフェニルリン酸、ナフチルリン酸、アルキルリン酸、グリセロリン酸等の有機リン酸；置換基を有していてもよいフェニルホスフィン酸、ナフチルホスフィン酸、アルキルホスフィン酸、グリセロホスフィン酸等の有機ホスフィン酸；グリシン、β−アラニン等のアミノ酸類；トリエタノールアミンの塩酸塩等のヒドロキシル基を有するアミンの塩酸塩；黄色染料が挙げられる。これらは単独で用いてもよく、２種以上を混合して用いてもよい。
【００８７】
有機下塗層は、以下のような方法で設けることができる。即ち、水もしくはメタノール、エタノール、メチルエチルケトン等の有機溶媒、またはそれらの混合溶剤に、上記有機化合物を溶解させた溶液をアルミニウム支持体上に塗布し乾燥して有機下塗層を設ける方法、水もしくはメタノール、エタノール、メチルエチルケトン等の有機溶媒、またはそれらの混合溶剤に、上記有機化合物を溶解させた溶液にアルミニウム支持体を浸せきさせて上記有機化合物を吸着させ、しかる後、水等によって洗浄し乾燥して有機下塗層を設ける方法によることができる。
【００８８】
前者の方法では、上記有機化合物を溶解させた溶液の濃度は、０．００５〜１０質量％であるのが好ましい。塗布の方法は、特に限定されず、バーコーター塗布、回転塗布、スプレー塗布、カーテン塗布等のいずれの方法も用いることができる。また、後者の方法では、上記有機化合物を溶解させた溶液の濃度は、０．０１〜２０質量％であるのが好ましく、０．０５〜５質量％であるのがより好ましく、浸せき温度は、２０〜９０℃であるのが好ましく、２５〜５０℃であるのがより好ましく、浸せき時間は、０．１秒〜２０分であるのが好ましく、２秒〜１分であるのがより好ましい。これらの方法に用いられる溶液は、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や、塩酸、リン酸等の酸性物質によりｐＨを調節し、ｐＨ１〜１２の範囲として使用することもできる。
【００８９】
有機下塗層の乾燥後の被覆量は、２〜２００ｍｇ／ｍ^２ であるのが好ましく、５〜１００ｍｇ／ｍ^２ であるのがより好ましい。上記範囲であると、耐刷性がより良好になる。
また、特開平１１−１０９６３７号公報に記載されている酸基とオニウム基とを有する高分子化合物の中間層を下塗層として用いることもできる。
【００９０】
［記録層］
本発明の平版印刷版用支持体には、画像等の記録層を設けて本発明の平版印刷版原版とすることができる。
本発明においては、上記平版印刷版用支持体上に、以下に説明する記録層を、乾燥後の塗布量が０．３〜１．８ｇ／ｍ^２ となるように設けるのが好ましい。記録層の塗布量を上記範囲に調整すると優れた耐刷性と高い感度の両立が可能となる。該塗布量が０．３ｇ／ｍ^２ 未満であると耐刷性が不十分となり、１．８ｇ／ｍ^２ 超であると感度が低下する傾向がある。
【００９１】
本発明の平版印刷版用支持体は、以下で説明する感熱層と組み合わせると、支持体表面の陽極酸化皮膜のマイクロポアが高い割合で無機化合物粒子で被覆されているため、感熱層成分のマイクロポア内への侵入の抑制が可能になり、現像速度が向上する。
【００９２】
上記本発明の平版印刷版用支持体上に設けられる画像等の情報の記録層には、感光性組成物が用いられる。
本発明に好適に用いられる感光性組成物としては、光熱変換物質を含有し露光部で発生する熱により画像を形成する『感熱性組成物』が望ましく、例えば、アルカリ可溶性高分子化合物と光熱変換物質とを含有するサーマルポジ型感光性組成物（以下、この組成物およびこれを用いた画像記録層について、「サーマルポジタイプ」という。）、硬化性化合物と光熱変換物質とを含有するサーマルネガ型感光性組成物（以下、同様に「サーマルネガタイプ」という。）を用いることが望ましい。さらに特別な現像工程を必要としない『感熱性組成物』（以下、同様に「無処理タイプ」という。）と組み合わせると印刷機上における湿し水による現像処理（機上現像）が非常に短時間で終わるという効果を得ることが可能となる。以下、これらの好適な感光性組成物について説明する。
【００９３】
＜サーマルポジタイプ＞
＜感光層＞
サーマルポジタイプの感光性組成物は、水不溶性かつアルカリ可溶性の高分子化合物（本発明において、「アルカリ可溶性高分子化合物」という。）と光熱変換物質とを含有する。サーマルポジタイプの画像記録層においては、光熱変換物質が赤外線レーザ等の光のエネルギーを熱に変換し、その熱がアルカリ可溶性高分子化合物のアルカリ溶解性を低下させている相互作用を効率よく解除する。
【００９４】
アルカリ可溶性高分子化合物としては、例えば、分子中に酸性基を含有する樹脂およびその２種以上の混合物が挙げられる。特に、フェノール性ヒドロキシ基、スルホンアミド基（−ＳＯ_２ ＮＨ−Ｒ（式中、Ｒは炭化水素基を表す。））、活性イミノ基（−ＳＯ_２ ＮＨＣＯＲ、−ＳＯ_２ ＮＨＳＯ_２ Ｒ、−ＣＯＮＨＳＯ_２ Ｒ（各式中、Ｒは上記と同様の意味である。））等の酸性基を有する樹脂がアルカリ現像液に対する溶解性の点で好ましい。
とりわけ、赤外線レーザ等の光による露光での画像形成性に優れる点で、フェノール性ヒドロキシ基を有する樹脂が好ましく、例えば、フェノール−ホルムアルデヒド樹脂、ｍ−クレゾール−ホルムアルデヒド樹脂、ｐ−クレゾール−ホルムアルデヒド樹脂、ｍ−／ｐ−混合クレゾール−ホルムアルデヒド樹脂、フェノール／クレゾール（ｍ−、ｐ−およびｍ−／ｐ−混合のいずれでもよい）混合−ホルムアルデヒド樹脂（フェノール−クレゾール−ホルムアルデヒド共縮合樹脂）等のノボラック樹脂が好適に挙げられる。
更に、特開２００１−３０５７２２号公報（特に［００２３］〜［００４２］）に記載されている高分子化合物、特開２００１−２１５６９３号公報に記載されている一般式（１）で表される繰り返し単位を含む高分子化合物、特開２００２−３１１５７０号公報（特に［０１０７］）に記載されている高分子化合物も好適に挙げられる。
【００９５】
光熱変換物質としては、記録感度の点で、波長７００〜１２００ｎｍの赤外域に光吸収域がある顔料または染料が好適に挙げられる。染料としては、例えば、アゾ染料、金属錯塩アゾ染料、ピラゾロンアゾ染料、ナフトキノン染料、アントラキノン染料、フタロシアニン染料、カルボニウム染料、キノンイミン染料、メチン染料、シアニン染料、スクワリリウム色素、ピリリウム塩、金属チオレート錯体（例えば、ニッケルチオレート錯体）が挙げられる。中でも、シアニン染料が好ましく、とりわけ特開２００１−３０５７２２号公報に記載されている一般式（Ｉ）で表されるシアニン染料が好ましい。
【００９６】
サーマルポジタイプの感光性組成物中には、溶解阻止剤を含有させることができる。溶解阻止剤としては、例えば、特開２００１−３０５７２２号公報の［００５３］〜［００５５］に記載されているような溶解阻止剤が好適に挙げられる。
また、サーマルポジタイプの感光性組成物中には、添加剤として、感度調節剤、露光による加熱後直ちに可視像を得るための焼出し剤、画像着色剤としての染料等の化合物、塗布性および処理安定性を向上させるための界面活性剤を含有させるのが好ましい。これらについては、特開２００１−３０５７２２号公報の［００５６］〜［００６０］に記載されているような化合物が好ましい。
上記以外の点でも、特開２００１−３０５７２２号公報に詳細に記載されている感光性組成物が好ましく用いられる。
【００９７】
また、サーマルポジタイプの画像記録層は、単層に限らず、２層構造であってもよい。
２層構造の画像記録層（重層系の画像記録層）としては、支持体に近い側に耐刷性および耐溶剤性に優れる下層（以下「Ａ層」という。）を設け、その上にポジ画像形成性に優れる層（以下「Ｂ層」という。）を設けたタイプが好適に挙げられる。このタイプは感度が高く、広い現像ラチチュードを実現することができる。Ｂ層は、一般に、光熱変換物質を含有する。光熱変換物質としては、上述した染料が好適に挙げられる。
Ａ層に用いられる樹脂としては、スルホンアミド基、活性イミノ基、フェノール性ヒドロキシ基等を有するモノマーを共重合成分として有するポリマーが耐刷性および耐溶剤性に優れている点で好適に挙げられる。Ｂ層に用いられる樹脂としては、フェノール性ヒドロキシ基を有するアルカリ水溶液可溶性樹脂が好適に挙げられる。
Ａ層およびＢ層に用いられる組成物には、上記樹脂のほかに、必要に応じて、種々の添加剤を含有させることができる。具体的には、特開２００２−３２３３７６９号公報の［００６２］〜［００８５］に記載されているような種々の添加剤が好適に用いられる。また、上述した特開２００１−３０５７２２号公報の［００５３］〜［００６０］に記載されている添加剤も好適に用いられる。
Ａ層およびＢ層を構成する各成分およびその含有量については、特開平１１−２１８９１４号公報に記載されているようにするのが好ましい。
【００９８】
＜中間層＞
サーマルポジタイプの画像記録層と支持体との間には、中間層を設けるのが好ましい。中間層に含有される成分としては、特開２００１−３０５７２２号公報の［００６８］に記載されている種々の有機化合物が好適に挙げられる。
【００９９】
＜その他＞
サーマルポジタイプの画像記録層の製造方法および製版方法については、特開２００１−３０５７２２号公報に詳細に記載されている方法を用いることができる。
【０１００】
＜サーマルネガタイプ＞
サーマルネガタイプの感光性組成物は、硬化性化合物と光熱変換物質とを含有する。サーマルネガタイプの画像記録層は、赤外線レーザ等の光で照射された部分が硬化して画像部を形成するネガ型の感光層である。
＜重合層＞
サーマルネガタイプの画像記録層の一つとして、重合型の画像記録層（重合層）が好適に挙げられる。重合層は、光熱変換物質と、ラジカル発生剤と、硬化性化合物であるラジカル重合性化合物と、バインダーポリマーとを含有する。重合層においては、光熱変換物質が吸収した赤外線を熱に変換し、この熱によりラジカル発生剤が分解してラジカルが発生し、発生したラジカルによりラジカル重合性化合物が連鎖的に重合し、硬化する。
【０１０１】
光熱変換物質としては、例えば、上述したサーマルポジタイプに用いられる光熱変換物質が挙げられる。特に好ましいシアニン色素の具体例としては、特開２００１−１３３９６９号公報の［００１７］〜［００１９］に記載されているものが挙げられる。
ラジカル発生剤としては、オニウム塩が好適に挙げられる。特に、特開２００１−１３３９６９号公報の［００３０］〜［００３３］に記載されているオニウム塩が好ましい。
ラジカル重合性化合物としては、末端エチレン性不飽和結合を少なくとも１個、好ましくは２個以上有する化合物が挙げられる。
バインダーポリマーとしては、線状有機ポリマーが好適に挙げられる。水または弱アルカリ水に対して可溶性または膨潤性である線状有機ポリマーが好適に挙げられる。中でも、アリル基、アクリロイル基等の不飽和基またはベンジル基と、カルボキシ基とを側鎖に有する（メタ）アクリル樹脂が、膜強度、感度および現像性のバランスに優れている点で好適である。
ラジカル重合性化合物およびバインダーポリマーについては、特開２００１−１３３９６９号公報の［００３６］〜［００６０］に詳細に記載されているものを用いることができる。
【０１０２】
サーマルネガタイプの感光性組成物中には、特開２００１−１３３９６９号公報の［００６１］〜［００６８］に記載されている添加剤（例えば、塗布性を向上させるための界面活性剤）を含有させるのが好ましい。
【０１０３】
重合層の製造方法および製版方法については、特開２００１−１３３９６９号公報に詳細に記載されている方法を用いることができる。
【０１０４】
＜酸架橋層＞
また、サーマルネガタイプの画像記録層の一つとして、酸架橋型の画像記録層（酸架橋層）も好適に挙げられる。酸架橋層は、光熱変換物質と、熱酸発生剤と、硬化性化合物である酸により架橋する化合物（架橋剤）と、酸の存在下で架橋剤と反応しうるアルカリ可溶性高分子化合物とを含有する。酸架橋層においては、光熱変換物質が吸収した赤外線を熱に変換し、この熱により熱酸発生剤が分解して酸が発生し、発生した酸により架橋剤とアルカリ可溶性高分子化合物とが反応し、硬化する。
【０１０５】
光熱変換物質としては、重合層に用いられるのと同様のものが挙げられる。
熱酸発生剤としては、例えば、光重合の光開始剤、色素類の光変色剤、マイクロレジスト等に使用されている酸発生剤等の熱分解化合物が挙げられる。
架橋剤としては、例えば、ヒドロキシメチル基またはアルコキシメチル基で置換された芳香族化合物；Ｎ−ヒドロキシメチル基、Ｎ−アルコキシメチル基またはＮ−アシルオキシメチル基を有する化合物；エポキシ化合物が挙げられる。
アルカリ可溶性高分子化合物としては、例えば、ノボラック樹脂、側鎖にヒドロキシアリール基を有するポリマーが挙げられる。
【０１０６】
＜無処理タイプ＞
無処理タイプの感熱層は、熱可塑性微粒子ポリマー型、マイクロカプセル型、スルホン酸発生ポリマー含有型、カチオン重合性モノマーまたはラジカル重合性モノマー含有型等が挙げられる。これらはいずれも光熱変換物質を含有する感熱型である。光熱変換物質は、上述したサーマルポジタイプに用いられるのと同様の染料が好ましい。
【０１０７】
熱可塑性微粒子ポリマー型の感光性組成物は、疎水性かつ熱溶融性の微粒子ポリマーが親水性高分子マトリックス中に分散されたものである。熱可塑性微粒子ポリマー型の画像記録層においては、露光により発生する熱により疎水性の微粒子ポリマーが溶融し、互いに融着して疎水性領域、即ち、画像部を形成する。
微粒子ポリマーとしては、微粒子同士が熱により溶融合体するものが好ましく、表面が親水性で、湿し水等の親水性成分に分散しうるものがより好ましい。具体的には、ＲｅｓｅａｃｈＤｉｓｃｌｏｓｕｒｅＮｏ．３３３０３（１９９２年１月）、特開平９−１２３３８７号、同９−１３１８５０号、同９−１７１２４９号および同９−１７１２５０号の各公報、欧州特許出願公開第９３１，６４７号明細書等に記載されている熱可塑性微粒子ポリマーが好適に挙げられる。中でも、ポリスチレンおよびポリメタクリル酸メチルが好ましい。親水性表面を有する微粒子ポリマーとしては、例えば、ポリマー自体が親水性であるもの；ポリビニルアルコール、ポリエチレングリコール等の親水性化合物を微粒子ポリマー表面に吸着させて表面を親水性化したものが挙げられる。
微粒子ポリマーは、反応性官能基を有するのが好ましい。
【０１０８】
マイクロカプセル型の感光性組成物としては、特開２０００−１１８１６０号公報に記載されているもの、特開２００１−２７７７４０号公報に記載されているような熱反応性官能基を有する化合物を内包するマイクロカプセル型が好適に挙げられる。
【０１０９】
本発明に用いられるマイクロカプセルは、上記熱反応性官能基を有する化合物を内包している。この熱反応性官能基を有する化合物としては、重合性不飽和基、ヒドロキシ基、カルボキシ基、カルボキシラート基、酸無水物、アミノ基、エポキシ基およびイソシアネート基ならびにそのブロック体から選ばれた少なくとも一個の官能基を有する化合物を挙げることができる。
【０１１０】
重合性不飽和基を有する化合物としては、エチレン性不飽和結合、例えば、アクリロイル基、メタクリロイル基、ビニル基、アリル基等を少なくとも１個、好ましくは２個以上有する化合物が好ましく、このような化合物群は当該産業分野において広く知られるものであり、本発明においては、これらを特に限定なく用いることができる。これらの化学的形態としては、モノマー、プレポリマー、即ち、２量体、３量体およびオリゴマーもしくはそれらの混合物またはそれらの共重合体が挙げられる。
【０１１１】
重合性不飽和基を有する化合物の具体例としては、不飽和カルボン酸（例えば、アクリル酸、メタクリル酸、イタコン酸、クロトン酸、イソクロトン酸、マレイン酸等）、そのエステルおよびアミドが挙げられ、好ましくは、不飽和カルボン酸と脂肪族多価アルコールとのエステルおよび不飽和カルボン酸と脂肪族多価アミンとのアミドが挙げられる。また、ヒドロキシ基、アミノ基、メルカプト基等の求核性置換基を有する不飽和カルボン酸エステルまたは不飽和カルボン酸アミドと、単官能もしくは多官能イソシアネートまたはエポキシドとの付加反応物、および、単官能または多官能のカルボン酸との脱水縮合反応物等も好適に挙げられる。また、イソシアネート基、エポキシ基等の親電子性置換基を有する不飽和カルボン酸エステルまたはアミドと、単官能または多官能のアルコール、アミンおよびチオールとの付加反応物、更に、ハロゲン基、トシルオキシ基等の脱離性置換基を有する不飽和カルボン酸エステルまたはアミドと、単官能または多官能アルコール、アミンおよびチオールとの置換反応物も好適に挙げられる。また、別の好適な例として、上記の不飽和カルボン酸を、不飽和ホスホン酸またはクロロメチルスチレンに置き換えた化合物が挙げられる。
【０１１２】
不飽和カルボン酸と脂肪族多価アルコールとのエステルである、重合性不飽和基を有する化合物のモノマーの具体例としては、フォトポリマータイプの感光層に用いられるエチレン性不飽和結合含有化合物として上記に例示した、各アクリル酸エステル、各メタクリル酸エステル、各イタコン酸エステル、各クロトン酸エステル、各イソクロトン酸エステルおよび各マレイン酸エステルが挙げられる。
【０１１３】
その他のエステルの例として、例えば、特公昭４６−２７９２６号、特公昭５１−４７３３４号および特開昭５７−１９６２３１号の各公報に記載されている脂肪族アルコール系エステル類、特開昭５９−５２４０号、特開昭５９−５２４１号および特開平２−２２６１４９号の各公報に記載されている芳香族系骨格を有するもの、特開平１−１６５６１３号公報に記載されているアミノ基を含有するもの等も好適に用いられる。
【０１１４】
また、不飽和カルボン酸と脂肪族多価アミンとのアミドのモノマーの具体例としては、メチレンビス−アクリルアミド、メチレンビス−メタクリルアミド、１，６−ヘキサメチレンビス−アクリルアミド、１，６−ヘキサメチレンビス−メタクリルアミド、ジエチレントリアミントリスアクリルアミド、キシリレンビスアクリルアミド、キシリレンビスメタクリルアミド等を挙げることができる。その他の好ましいアミド系モノマーの例としては、特公昭５４−２１７２６号公報に記載されているシクロへキシレン構造を有するものを挙げることができる。
【０１１５】
また、重合性不飽和基を有する化合物として、イソシアネート基とヒドロキシ基との付加反応を用いて製造されるウレタン系付加重合性化合物も好適に用いられ、その具体例としては、例えば、特公昭４８−４１７０８号公報中に記載されている１分子に２個以上のイソシアネート基を有するポリイソシアネート化合物に、下記式（Ｉ）で示されるヒドロキシ基を有する不飽和モノマーを付加させた１分子中に２個以上の重合性不飽和基を含有するウレタン化合物等が挙げられる。
【０１１６】
ＣＨ_２ ＝Ｃ（Ｒ^１ ）ＣＯＯＣＨ_２ ＣＨ（Ｒ^２ ）ＯＨ・・・（Ｉ）
（上記式（Ｉ）中、Ｒ^１ およびＲ^２ は、それぞれＨまたはＣＨ_３ を示す。）
【０１１７】
また、特開昭５１−３７１９３号、特公平２−３２２９３号および特公平２−１６７６５号の各公報に記載されているようなウレタンアクリレートや、特公昭５８−４９８６０号、特公昭５６−１７６５４号、特公昭６２−３９４１７号および特公昭６２−３９４１８号の各公報に記載されているエチレンオキサイド系骨格を有するウレタン化合物も好適なものとして挙げることができる。
【０１１８】
更に、特開昭６３−２７７６５３号、特開昭６３−２６０９０９号および特開平１−１０５２３８号の各公報に記載されている、分子内にアミノ構造やスルフィド構造を有するラジカル重合性化合物を好適なものとして挙げることができる。
【０１１９】
その他の好適なものの例としては、特開昭４８−６４１８３号、特公昭４９−４３１９１号および同５２−３０４９０号の各公報に記載されているようなポリエステルアクリレート類、エポキシ樹脂と（メタ）アクリル酸とを反応させたエポキシアクリレート類等の多官能の（メタ）アクリレートを挙げることができる。また、特公昭４６−４３９４６号、特公平１−４０３３７号および同１−４０３３６号の各公報に記載されている特定の不飽和化合物や、特開平２−２５４９３号公報に記載されているビニルホスホン酸系化合物等も好適なものとして挙げることができる。また、ある場合には、特開昭６１−２２０４８号公報に記載されているペルフルオロアルキル基を含有する化合物も好適に使用される。更に、日本接着協会誌、２０巻７号、ｐ．３００−３０８（１９８４年）に、光硬化性モノマーおよびオリゴマーとして紹介されているものも好適に使用することができる。
【０１２０】
エポキシ基を有する化合物としては、グリセリンポリグリシジルエーテル、ポリエチレングリコールジグリシジルエーテル、ポリプロピレンジグリシジルエーテル、トリメチロールプロパンポリグリシジルエーテル、ソルビトールポリグリシジルエーテル、ビスフェノール類もしくはポリフェノール類またはそれらの水素添加物のポリグリシジルエーテル等が好適に挙げられる。
【０１２１】
イソシアネート基を有する化合物としては、トリレンジイソシアネート、ジフェニルメタンジイソシアネート、ポリメチレンポリフェニルポリイソシアネート、キシリレンジイソシアネート、ナフタレンジイソシアネート、シクロヘキサンフェニレンジイソシアネート、イソホロンジイソシアネート、ヘキサメチレンジイソシアネート、シクロヘキシルジイソシアネート；それらをアルコールまたはアミンでブロックした化合物が好適に挙げられる。
【０１２２】
アミノ基を有する化合物としては、エチレンジアミン、ジエチレントリアミン、トリエチレンテトラミン、ヘキサメチレンジアミン、プロピレンジアミン、ポリエチレンイミン等が好適に挙げられる。
【０１２３】
ヒドロキシ基を有する化合物としては、末端メチロール基を有する化合物、ペンタエリスリトール等の多価アルコール、ビスフェノール・ポリフェノール類等が好適に挙げられる。カルボキシ基を有する化合物としては、ピロメリット酸、トリメリット酸、フタル酸等の芳香族多価カルボン酸、アジピン酸等の脂肪族多価カルボン酸等が好適に挙げられる。酸無水物を有する化合物としては、ピロメリット酸無水物、ベンゾフェノンテトラカルボン酸無水物等が好適に挙げられる。
【０１２４】
エチレン性不飽和結合を有する化合物の共重合体としては、アリルメタクリレートの共重合体が好適に挙げられる。具体的には、アリルメタクリレート／メタクリル酸共重合体、アリルメタクリレート／エチルメタクリレート共重合体、アリルメタクリレート／ブチルメタクリレート共重合体等を挙げることができる。
【０１２５】
熱反応性官能基を有する化合物を内包するマイクロカプセルの製造方法としては、公知の方法が適用できる。例えば、マイクロカプセルの製造方法として、米国特許第２，８００，４５７号明細書および同第２，８００，４５８号明細書に記載されているコアセルベーションを利用した方法、英国特許９９０，４４３号明細書、米国特許第３，２８７，１５４号明細書、特公昭３８−１９５７４号、同４２−４４６号および同４２−７１１号の各公報に記載されている界面重合法による方法、米国特許第３，４１８，２５０号明細書および同第３，６６０，３０４号明細書に記載されているポリマーの析出による方法、米国特許第３，７９６，６６９号明細書に記載されているイソシアネートポリオール壁材料を用いる方法、米国特許第３，９１４，５１１号に記載されているイソシアネート壁材料を用いる方法、米国特許第４，００１，１４０号、同第４，０８７，３７６号および同第４，０８９，８０２号の各明細書に記載されている尿素−ホルムアルデヒド系または尿素ホルムアルデヒド−レゾルシノール系壁形成材料を用いる方法、米国特許第４，０２５，４４５号明細書に記載されているメラミン−ホルムアルデヒド樹脂、ヒドロキシセルロース等の壁材を用いる方法、特公昭３６−９１６３号公報および同５１−９０７９号公報に記載されているモノマー重合によるｉｎｓｉｔｕ法、英国特許第９３０，４２２号明細書および米国特許第３，１１１，４０７号明細書に記載されているスプレードライング法、英国特許第９５２，８０７号明細書および同第９６７，０７４号明細書に記載されている電解分散冷却法等を用いることができる。
【０１２６】
熱反応性官能基を有する化合物を内包するマイクロカプセルに用いられるマイクロカプセル壁は、３次元架橋を有し、溶剤によって膨潤する性質を有するものであるのが好ましい。この観点から、マイクロカプセルの壁材は、ポリウレア、ポリウレタン、ポリエステル、ポリカーボネート、ポリアミド、またはこれらの混合物が好ましく、中でも、ポリウレアおよび／またはポリウレタンがより好ましい。上記マイクロカプセル壁には、上記熱反応性官能基を有する化合物を導入してもよい。
【０１２７】
熱反応性官能基を有する化合物を内包するマイクロカプセルの平均粒径は、０．０１〜２０μｍであるのが好ましく、０．０５〜２．０μｍであるのがより好ましく、０．１０〜１．０μｍであるのが更に好ましい。平均粒径が大きすぎると解像度が悪くなり、また、小さすぎると経時安定性が悪くなってしまう。
【０１２８】
このような熱反応性官能基を有する化合物を内包するマイクロカプセルは、マイクロカプセル同士が熱により合体するものであってもよいし、合体しないものであってもよい。要は、マイクロカプセル内包物のうち、塗布時にカプセル表面またはマイクロカプセル外に滲み出したもの、または、マイクロカプセル壁に浸入したものが、熱により化学反応を起こせばよい。また、添加された親水性樹脂、または、添加された低分子化合物と反応してもよい。また、２種以上のマイクロカプセルに、それぞれ異なる官能基で互いに熱反応するような官能基をもたせることによって、マイクロカプセル同士を反応させてもよい。したがって、熱によってマイクロカプセル同士が、熱で溶融合体することは画像形成上好ましいことであるが、必須ではない。
【０１２９】
感熱層における熱反応性官能基を有する化合物を内包するマイクロカプセルの含有量は、感熱層の全固形分に対して、１０〜６０質量％であるのが好ましく、１５〜４０質量％であるのがより好ましい。上記範囲内であると、良好な機上現像性と同時に、良好な感度および耐刷性が得られる。
【０１３０】
熱反応性官能基を有する化合物を内包するマイクロカプセルを感熱層に含有させる場合、内包物を溶解させることができ、かつ、壁材を膨潤させることができる溶剤をマイクロカプセル分散媒中に添加することができる。このような溶剤によって、内包された熱反応性官能基を有する化合物のマイクロカプセル外への拡散が促進される。このような溶剤の選択は、マイクロカプセル分散媒、マイクロカプセル壁の材質、壁厚および内包物に依存するが、多くの市販されている溶剤から容易に選択することができる。例えば、架橋ポリウレアやポリウレタン壁からなる水分散性マイクロカプセルの場合、アルコール類、エーテル類、アセタール類、エステル類、ケトン類、多価アルコール類、アミド類、アミン類、脂肪酸類等が好ましい。
【０１３１】
具体的には、メタノール、エタノール、第三ブタノール、ｎ−プロパノール、テトラヒドロフラン、乳酸メチル、乳酸エチル、メチルエチルケトン、プロピレングリコールモノメチルエーテル、エチレングリコールジエチルエーテル、エチレングリコールモノメチルエーテル、γ−ブチルラクトン、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド等が挙げられるが、本発明はこれらに限られない。また、これらの溶剤を２種以上用いてもよい。
【０１３２】
また、マイクロカプセル分散液には溶解しないが、前記溶剤を混合すれば溶解する溶剤も用いることができる。その添加量は、素材の組み合わせにより決まるものであるが、適性値より少ない場合は、画像形成が不十分となり、多い場合は分散液の安定性が劣化する。通常、塗布液の５〜９５質量％であるのが有効であり、１０〜９０質量％であるのが好ましく、１５〜８５質量％であるのがより好ましい。
【０１３３】
無処理タイプの感熱層が、熱反応性官能基を有する微粒子ポリマーおよび／または熱反応性官能基を有する化合物を内包するマイクロカプセルを含有する場合には、必要に応じて、これらの反応を開始させまたは促進させる化合物を添加してもよい。反応を開始させまたは促進させる化合物としては、熱によりラジカルまたはカチオンを発生するような化合物を挙げることができる。例えば、ロフィンダイマー、トリハロメチル化合物、過酸化物、アゾ化合物、オニウム塩（ジアゾニウム塩、ジフェニルヨードニウム塩等）、アシルホスフィン、イミドスルホナート等が挙げられる。これらの化合物の含有量は、感熱層の全固形分に対して、１〜２０質量％であるのが好ましく、３〜１０質量％であるのがより好ましい。上記範囲内であると、機上現像性を損なわず、良好な反応開始効果または反応促進効果が得られる。
【０１３４】
スルホン酸発生ポリマー含有型の感光性組成物に用いられるスルホン酸発生ポリマーとしては、例えば、特開平１０−２８２６７２号公報に記載されているスルホン酸エステル基、ジスルホン基またはｓｅｃ−もしくはｔｅｒｔ−スルホンアミド基を側鎖に有するポリマーが挙げられる。
【０１３５】
カチオン重合性モノマーまたはラジカル重合性モノマー含有型の画像記録層としてはＷＯ０２／２１２１５（ ＵＳ２００２／００６８２４０Ａ１） 公報に記載されているような感熱層を用いることが出来る。
【０１３６】
無処理タイプの感光性組成物に、親水性樹脂を含有させることにより、機上現像性が良好となるばかりか、感光層自体の皮膜強度も向上する。親水性樹脂としては、例えば、ヒドロキシ基、カルボキシ基、ヒドロキシエチル基、ヒドロキシプロピル基、アミノ基、アミノエチル基、アミノプロピル基、カルボキシメチル基等の親水基を有するもの、親水性のゾルゲル変換系結着樹脂が好ましい。
【０１３７】
無処理タイプの画像記録層は、特別な現像工程を必要とせず、印刷機上で現像することができる。無処理タイプの画像記録層の製造方法および製版印刷方法については、特開２００２−１７８６５５号公報に詳細に記載されている方法を用いることができる。
【０１３８】
無処理タイプの感熱層には、光熱変換物質を添加することが必要である。光熱変換物質は、波長７００ｎｍ以上の光を吸収する物質であればよく、種々の顔料、染料および金属微粒子を用いることができる。
【０１３９】
前記顔料としては、市販の顔料、ならびに、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）および「印刷インキ技術」ＣＭＣ出版、１９８４年刊）に記載されている顔料を利用することができる。具体的には、例えば、サーマルポジタイプの感熱層に含有される光熱変換物質として、上記に例示した顔料が挙げられる。
【０１４０】
これらの顔料は、サーマルポジタイプの感熱層に含有される顔料と同様に、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。
【０１４１】
中でも、赤外線を吸収する顔料が、赤外線を発光するレーザの利用に適する点で好ましい。このような赤外線を吸収する顔料としては、カーボンブラックが好ましく、中でも、水溶性または親水性の樹脂と分散しやすく、かつ、親水性を損わないように、親水性樹脂やシリカゾルで表面がコートされたカーボンブラックが特に好ましい。顔料の粒径は、０．０１μｍ〜１μｍの範囲にあることが好ましく、０．０１μｍ〜０．５μｍの範囲にあることがより好ましい。
【０１４２】
前記染料としては、市販の染料および文献（例えば、「染料便覧」有機合成化学協会編集、昭和４５年刊）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、アントラキノン染料、フタロシアニン染料、カルボニウム染料、キノンイミン染料、メチン染料、シアニン染料等の染料が挙げられる。中でも、赤外線を吸収する染料が、赤外線を発光するレーザでの利用に適する点で特に好ましい。
【０１４３】
赤外線を吸収する染料としては、例えば、特開昭５８−１２５２４６号、特開昭５９−８４３５６号、特開昭６０−７８７８７号の各公報等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号の各公報等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号の各公報等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ワリリウム染料、英国特許４３４，８７５号明細書に記載されているシアニン染料や米国特許第４，７５６，９９３号明細書に記載されている染料、米国特許第４，９７３，５７２号明細書に記載されているシアニン染料、特開平１０−２６８５１２号公報に記載されている染料を挙げることができる。
【０１４４】
また、染料として、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染料、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等、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；ＥｐｏｌｉｇｈｔＩＩＩ−１７８、ＥｐｏｌｉｇｈｔＩＩＩ−１３０、ＥｐｏｌｉｇｈｔＩＩＩ−１２５（いずれもエポリン社製）等も好適に用いられる。中でも、特に好ましい染料は水溶性染料であり、以下に具体例を構造式で列挙する。
【０１４５】
【化２】

【０１４６】
【化３】

【０１４７】
【化４】

【０１４８】
【化５】

【０１４９】
【化６】

【０１５０】
【化７】

【０１５１】
【化８】

【０１５２】
【化９】

【０１５３】
前記金属微粒子としては、光熱変換性で光照射によって熱融着する金属微粒子であれば特に限定されないが、８〜１１族（第ＶＩＩＩ族および第ＩＢ族）に属する金属の単体または合金の微粒子であるのが好ましく、Ａｇ、Ａｕ、Ｃｕ、ＰｔおよびＰｄから選ばれる金属の単体または合金の微粒子であるのがより好ましい。金属微粒子は、分散安定剤を含む水溶液に上記金属の塩または錯塩の水溶液を添加し、更に還元剤を添加して金属コロイドとした後、不要な塩類を除去して用いられる。
【０１５４】
分散安定剤としては、例えば、クエン酸、シュウ酸等のカルボン酸およびその塩；ＰＶＰ、ＰＶＡ、ゼラチン、アクリル樹脂等のポリマーが挙げられる。還元剤としては、例えば、卑金属塩（例えば、ＦｅＳＯ４ 、ＳｎＳＯ４ ）、水素化ホウ素化合物、ホルマリン、デキストリン、ブドウ糖、ロッセル塩、酒石酸、チオ硫酸ナトリウム、次亜リン酸塩が挙げられる。金属コロイドの平均粒子径は、１〜５００ｎｍであるのが好ましく、１〜１００ｎｍであるのがより好ましく、１〜５０ｎｍであるのが更に好ましい。その分散度は多分散でもよいが、変動係数が３０％以下の単分散の方が好ましい。不要な塩類を除去する方法としては、例えば、限外ろ過法；コロイド分散系にメタノールと水との混合溶液またはエタノールと水との混合溶液を添加して、自然沈降させ、または遠心沈降させて、その上澄み液を除去する方法が挙げられる。
【０１５５】
光熱変換物質の含有量は、顔料または染料の場合、感熱層の全固形分に対して、３０質量％以下であるのが好ましく、５〜２５質量％であるのがより好ましく、７〜２０質量％であるのが更に好ましい。また、金属微粒子の場合、感熱層の全固形分の５質量％以上であるのが好ましく、１０質量％以上であるのがより好ましく、２０質量％以上であるのが更に好ましい。金属微粒子の含有量が５質量％未満であると、感度が低くなってしまう場合がある。
【０１５６】
無処理タイプの感熱層には、必要に応じて、上述した成分以外に、種々の化合物を含有することができる。例えば、耐刷性を一層向上させるために多官能モノマーを感熱層のマトリックス中に含有させることができる。このような多官能モノマーとしては、マイクロカプセル中に内包されるモノマーとして例示したものを用いることができる。特に好ましいモノマーとしては、トリメチロールプロパントリアクリレートを挙げることができる。
【０１５７】
また、無処理タイプの感熱層には、画像形成後、画像部と非画像部との区別をつけやすくするため、可視光域に大きな吸収を持つ染料を画像の着色剤として使用することができる。具体的には、オイルイエロー＃１０１、オイルイエロー＃１０３、オイルピンク＃３１２、オイルグリーンＢＧ、オイルブルーＢＯＳ、オイルブルー＃６０３、オイルブラックＢＹ、オイルブラックＢＳ、オイルブラックＴ−５０５（以上、オリエント化学工業社製）、ビクトリアピュアブルー、クリスタルバイオレット（ＣＩ４２５５５）、メチルバイオレット（ＣＩ４２５３５）、エチルバイオレット、ローダミンＢ（ＣＩ１４５１７０Ｂ）、マラカイトグリーン（ＣＩ４２０００）、メチレンブルー（ＣＩ５２０１５）、特開昭６２−２９３２４７号公報に記載されている染料を挙げることができる。また、フタロシアニン系顔料、アゾ系顔料、酸化チタン等の顔料も、同様に好適に用いることができる。これらの含有量は、感熱層の全固形分に対して、０．０１〜１０質量％であるのが好ましい。
【０１５８】
また、無処理タイプの感熱層がエチレン性不飽和結合を有する化合物を含有する場合、その不要な熱重合を阻止するために、少量の熱重合防止剤を添加することが好ましい。好適な熱重合防止剤としてはハイドロキノン、ｐ−メトキシフェノール、ジ−ｔ−ブチル−ｐ−クレゾール、ピロガロール、ｔ−ブチルカテコール、ベンゾキノン、４，４′−チオビス（３−メチル−６−ｔ−ブチルフェノール）、２，２′−メチレンビス （４−メチル−６−ｔ−ブチルフェノール）、Ｎ−ニトロソ−Ｎ−フェニルヒドロキシルアミンアルミニウム塩等が挙げられる。熱重合防止剤の含有量は、感熱層の全固形分に対して、約０．０１〜約５質量％であるのが好ましい。
【０１５９】
また、無処理タイプの感熱層には、必要に応じて、酸素による重合阻害を防止するためにベヘン酸やベヘン酸アミドのような高級脂肪酸誘導体等を添加して、塗布後の乾燥の過程で感熱層の表面に偏在させてもよい。高級脂肪酸誘導体の含有量は、感熱層の全固形分に対して、約０．１〜約１０質量％であるのが好ましい。
【０１６０】
更に、無処理タイプの感熱層は、必要に応じて、塗膜の柔軟性等を付与するために可塑剤を含有することができる。可塑剤としては、例えば、ポリエチレングリコール、クエン酸トリブチル、フタル酸ジエチル、フタル酸ジブチル、フタル酸ジヘキシル、フタル酸ジオクチル、リン酸トリクレジル、リン酸トリブチル、リン酸トリオクチル、オレイン酸テトラヒドロフルフリル等が用いられる。
【０１６１】
また、無処理タイプの感熱層は、無機微粒子を含有することができる。無機微粒子としては、例えば、シリカ、アルミナ、酸化マグネシウム、炭酸マグネシウム、アルギン酸カルシウム等が挙げられる。これらは光熱変換性ではなくても、皮膜の強化、感熱層の表面粗面化による界面接着性の強化等の効果を奏する。無機微粒子の含有量は、感熱層の全固形分に対して、１．０〜７０質量％であるのが好ましく、５．０〜５０質量％であるのがより好ましい。１％以下であると期待される効果が小さく、また、７０質量％以上であると本来必要な光熱変換物質の含有量が制約される場合がある。
【０１６２】
また、無処理タイプの感熱層は、親水性ゾル状粒子を含有することができる。
親水性ゾル状粒子としては、例えば、シリカゾル、アルミナゾル、酸化マグネシウムゾル、炭酸マグネシウムゾル、アルギン酸カルシウムゾルが好適に挙げられる。中でも、シリカゾル、アルミナゾル、アルギン酸カルシウムゾルまたはこれらの混合物が好ましい。これらは光熱変換性ではなくても、親水性の向上、ゾルゲル膜の強化等の効果を奏する。
【０１６３】
シリカゾルは、表面に多くのヒドロキシ基を有し、内部はシロキサン結合 （−Ｓｉ−Ｏ−Ｓｉ）で構成されている。シリカゾルは、粒子径１〜１００ｎｍのシリカ超微粒子が、水または極性溶媒の中に分散したものであり、コロイダルシリカとも称されている。シリカゾルの詳細は、加賀美敏郎、林瑛監修「高純度シリカの応用技術」第３巻、（株）シーエムシー（１９９１年）に記載されている。アルミナゾルは、５〜２００ｎｍのコロイドの大きさを有するアルミナ水和物（ベーマイト系）であり、水中の陰イオン（例えば、フッ化物イオン、塩化物イオン等のハロゲンイオン、酢酸イオン（ａｃｅｔａｔｅ）等のカルボン酸アニオン（ｃａｒｂｏｘｙｌａｔｏ）等）を安定剤としてアルミナが分散されたものである。これらの親水性ゾル状粒子は、いずれも、市販品として容易に入手することができる。
【０１６４】
上記親水性ゾル状粒子の平均粒径は、１０〜５０ｎｍであるのが好ましく、１０〜４０ｎｍであるのがより好ましい。親水性ゾル状粒子の粒径が上記範囲内であると、親水性樹脂内において、光熱変換物質として含有される金属微粒子等や、上述した疎水性熱溶融性樹脂微粒子等の疎水性化前駆体（露光しない状態では疎水性であり、露光により疎水性となる成分）とともに安定に分散して、感熱層の膜強度を十分に保持することができ、また、レーザー光等により露光して製版し、平版印刷版として印刷したときに、非画像部へのインキの付着汚れを生じない、極めて親水性に優れたものになるという効果が得られる。
【０１６５】
上記光熱変換物質（好ましくはカーボンブラック、金属微粒子）と上記親水性ゾル状粒子の存在割合は、質量比で、１００／０〜３０／７０であるのが好ましく、１００／０〜４０／６０であるのがより好ましい。また、光熱変換物質、疎水性化前駆体および親水性ゾル状粒子の合計の含有量は、感熱層の全固形分に対して、２〜９５質量％であるのが好ましく、５〜８５質量％であるのがより好ましい。
【０１６６】
＜バックコート＞
このようにして、本発明の平版印刷版用支持体上に各種の画像記録層を設けて得られる本発明の平版印刷版原版の裏面には、必要に応じて、重ねた場合における画像記録層の傷付きを防止するために、有機高分子化合物からなる被覆層を設けることができる。
【０１６７】
＜記録層の形成方法＞
画像記録層等の各層は、通常、上記各成分を溶媒に溶かして得られる塗布液を、平版印刷版用支持体上に塗布することにより製造することができる。
ここで使用する溶媒としては、エチレンジクロライド、シクロヘキサノン、メチルエチルケトン、メタノール、エタノール、プロパノール、エチレングリコールモノメチルエーテル、１−メトキシ−２−プロパノール、２−メトキシエチルアセテート、１−メトキシ−２−プロピルアセテート、ジメトキシエタン、乳酸メチル、乳酸エチル、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ，Ｎ−ジメチルホルムアミド、テトラメチルウレア、Ｎ−メチルピロリドン、ジメチルスルホキシド、スルホラン、γ−ブチルラクトン、トルエン、水等を挙げることができるが、本発明はこれらに限定されるものではない。これらの溶剤は単独でまたは混合して使用される。
溶媒中の上記成分（全固形分）の濃度は、１〜５０質量％であるのが好ましい。
【０１６８】
塗布する方法としては、種々の方法を用いることができるが、例えば、バーコーター塗布、回転塗布、スプレー塗布、カーテン塗布、ディップ塗布、エアーナイフ塗布、ブレード塗布、ロール塗布等を挙げることができる。
【０１６９】
［製版方法（平版印刷版の製造方法）］
本発明の平版印刷版用支持体を用いた平版印刷版原版は、画像記録層に応じた種々の処理方法により、平版印刷版とされる。
像露光に用いられる活性光線の光源としてはレーザビームが主に挙げられる。例えば、ヘリウム−ネオンレーザ（Ｈｅ−Ｎｅレーザ）、アルゴンレーザ、クリプトンレーザ、ヘリウム−カドミウムレーザ、ＫｒＦエキシマーレーザ、半導体レーザ、ＹＡＧレーザ、ＹＡＧ−ＳＨＧレーザが挙げられる。
【０１７０】
上記露光の後、画像記録層がサーマルポジタイプ、サーマルネガタイプである場合は、露光した後、現像液を用いて現像して平版印刷版を得るのが好ましい。現像液は、アルカリ現像液であるのが好ましく、有機溶剤を実質的に含有しないアルカリ性の水溶液であるのがより好ましい。
また、アルカリ金属ケイ酸塩を実質的に含有せずかつ糖類を含有する現像液（アルカリ金属ケイ酸塩を実質的に含有しない現像液）も好ましい。アルカリ金属ケイ酸塩を実質的に含有しない現像液を用いて現像する方法としては、特開平１１−１０９６３７号公報に詳細に記載されている方法を用いることができる。
また、アルカリ金属ケイ酸塩を含有する現像液を用いることもできる。
【０１７１】
実質的にアルカリ金属ケイ酸塩を含有しない現像液を用いて現像する平版印刷版原版の処理方法を用いると、アルカリ金属ケイ酸塩を含有する現像液を用いて現像する場合における問題、即ち、ＳｉＯ_２ に起因する固形物が析出しやすいこと、現像液の廃液を処理する際の中和処理においてＳｉＯ_２ に起因するゲルが生成すること等の問題の発生を防止することができる。
【０１７２】
【実施例】
（実施例１）
＜アルミニウム板＞
Ｓｉ：０．０６質量％、Ｆｅ：０．２８質量％、Ｃｕ：０．０２５質量％、Ｍｎ：０．００１質量％、Ｍｇ：０．００１質量％、Ｚｎ：０．００１質量％、Ｔｉ：０．０３質量％、Ｐｂ：０．００１質量％を含有し、残部はＡｌと不可避不純物のアルミニウム合金Ａ、及びＣｕ：０．００１質量％で他の成分は合金Ａと同様であるアルミニウム合金Ｂを用いて溶湯を調製し、溶湯処理およびろ過を行った上で、厚さ５００ｍｍ、幅１２００ｍｍの鋳塊をＤＣ鋳造法で作成した。表面を平均１０ｍｍの厚さで面削機により削り取った後、５５０℃で、約５時間均熱保持し、温度４００℃に下がったところで、熱間圧延機を用いて厚さ２．７ｍｍの圧延板とした。更に、連続焼鈍機を用いて熱処理を５００℃で行った後、冷間圧延で、厚さ０．２４ｍｍに仕上げた。このアルミニウム材はＪＩＳ １０５０材の範囲であった。このアルミニウム板を幅１０３０ｍｍにした後、以下に示す表面処理に供した。
【０１７３】
＜表面処理＞
実施例の各水準の表面処理は、以下の（ａ）〜（ｎ）の各種処理を第１表に示す製造工程欄でアルファベットの表示で示すように組み合わせて連続的に行うことにより実施した。なお、各処理および水洗の後にはニップローラで液切りを行った。
（ａ）機械的粗面化処理
図１に示したような装置を使って、比重１．１２の研磨剤（パミストン）と水との懸濁液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４０μｍ、最大粒径は８０μｍであった。ナイロンブラシの材質は６・１０ナイロン、毛長は４５ｍｍ、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２５０ｍｍ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。
【０１７４】
（ｂ）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６０℃の水溶液を用いてスプレーによるエッチング処理を行い、アルミニウム板を６ｇ／ｍ^２ 溶解した。その後、スプレーによる水洗を行った。
【０１７５】
（ｃ）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、２０秒間スプレーによるデスマット処理を行い、その後、スプレーで水洗した。デスマット処理に用いた硝酸水溶液は、硝酸水溶液中で交流を用いて電気化学的粗面化処理を行う工程の廃液を用いた。
【０１７６】
（ｄ）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１０．４ｇ／Ｌ水溶液（アルミニウムイオンを５ｇ／Ｌ、アンモニウムイオンを０．００７質量％含む。）、液温５０℃であった。電流値がゼロからピークに達するまでの時間ＴＰが０．８ｍｓｅｃ、ｄｕｔｙ比１：１、台形の矩形波交流を用いて、カーボン電極を対極として電気化学的な粗面化処理を行った。補助アノードにはフェライトを用いた。
電流密度は電流のピーク値で３０Ａ／ｄｍ^２ 、電気量はアルミニウム板が陽極時の電気量の総和で１９５Ｃ／ｄｍ^２ であった。補助陽極には電源から流れる電流の５％を分流させた。
その後、スプレーによる水洗を行った。
【０１７７】
（ｅ）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３２℃で行い、アルミニウム板を０．５ｇ／ｍ^２ 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。
【０１７８】
（ｆ）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、２０秒間スプレーによるデスマット処理を行い、その後、スプレーで水洗した。デスマット処理に用いた硫酸水溶液は、硫酸水溶液中で交流を用いて電気化学的粗面化処理を行う工程の廃液を用いた。
【０１７９】
（ｇ）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、塩酸５ｇ／Ｌ水溶液（アルミニウムイオンを５ｇ／Ｌ含む。）、温度３５℃であった。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。使用した電解槽は２に示すものを使用した。
電流密度は電流のピーク値で２５Ａ／ｄｍ^２ 、電気量はアルミニウム板が陽極時の電気量の総和で６０Ｃ／ｄｍ^２ であった。
その後、スプレーによる水洗を行った。
【０１８０】
（ｈ）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３２℃で行い、アルミニウム板を０．２ｇ／ｍ^２ 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。
【０１８１】
（ｉ）デスマット処理
温度６０℃の硫酸濃度２５質量％水溶液（アルミニウムイオンを０．５質量％含む。）で、２０秒間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。
【０１８２】
（ｊ）陽極酸化処理
図３に示す構造の陽極酸化装置を用いて陽極酸化処理を行った。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１７０ｇ／Ｌ（アルミニウムイオンを０．５質量％含む。）、温度３８℃であった。その後、スプレーによる水洗を行った。最終的な酸化皮膜量は２．７ｇ／ｍ^２ であった。
ポア径の測定は、上述の方法で行った。
（ｋ）ポアワイド処理
陽極酸化処理後のアルミニウム板をｐＨ１３の水酸化ナトリウム水溶液に、温度３０℃で２０秒間〜４０秒の間で浸漬することでポアワイドを行い、第１表に示す異なるポア径（平均ポア径）の皮膜を生成した。その後、水洗、乾燥を行った。
【０１８３】
（ｌ）無機化合物粒子層の形成
ポアワイド処理後のアルミニウム板に、以下の無機化合物粒子を含む水懸濁液を調整し、それぞれバーコーターを用いて乾燥後の塗布量が０．０５ｇ／ｍ^２ になるように塗布し、オーブンを用いて１００℃で２分間乾燥し、第１表に示す無機化合物粒子層を形成した。以下の短径、長径の記載は平均値である。測定方法は、無機化合物粒子の懸濁液 （固形分濃度として０．２％）をプレパラート上に滴下し、静置した状態で乾燥後、表面にカーボンを蒸着し固定する。このように作成した試料表面を走査型電子顕微鏡（Ｓ−９００、日立製作所製）によって加速電圧１２ｋＶ、倍率１２万倍で観察し、撮影したＳＥＭ写真を元に少なくとも１０個の粒子の最長径、最短径を測定し、それぞれの平均値を算出して長径、短径とした。
１）短径１０ｎｍ、長径１００ｎｍ（アスペクト比＝１０）の羽毛状コロイダルアルミナ粒子（日産化学製、ＡＳ２００）を０．５質量％含有する水懸濁液、
２）短径４０ｎｍ、長径２００ｎｍ（アスペクト比＝５）の鱗片状チタニア粒子（石原産業製、）を０．５質量％含有する水懸濁液、
３）短径＝長径＝１０ｎｍ（アスペクト比＝１）の粒状アルミナゾル粒子（日産化学製、ＡＳ５２０）を０．５質量％含有する水懸濁液、
４）短径＝長径＝３０ｎｍ（アスペクト比＝１）の粒状アルミナゾル粒子（シーアイ化成製、Ｎａｎｏｔｅｋ アルミナ）を０．５質量％含有する水懸濁液。
【０１８４】
（ｍ）固着処理
無機化合物粒子層形成後のアルミニウム板に下記の固着処理をそれぞれ行い、その後、スプレーによる水洗を行い、乾燥して、陽極酸化皮膜上に無機化合物層を設けてなる実施例１〜１１、比較例１〜９の平版印刷版用支持体を得た。
１）３号ケイ酸ナトリウムの１０質量％水溶液：実施例１， ３， ５， ６、比較例２，４，６
２）リン酸／ 塩化アルミの水溶液（ｐＨ４．３）：実施例２， ８、９， １１、比較例３，７，８
３）ＮａＦ（４．５ｇ）／Ｎａ_２ ＨＰＯ_４（５８５ｇ） ／水（３９１０ｇ）の水溶液（ｐＨ４．３）：実施例４， ７， １０、比較例１，５、９
のそれぞれの液中に浸漬することで固着処理を行った。処理液温度は７０℃、浸せき処理時間は１０秒であった。その後、スプレーによる水洗を行い、乾燥して、陽極酸化皮膜上に無機化合物層を設けた。
【０１８５】
（ｎ）親水化処理
３号ケイ酸ナトリウムの１質量％水溶液に３０℃で１０秒間浸漬し、その後、スプレーによる水洗、乾燥を行って表面親水化（アルカリ金属ケイ酸塩処理）を行った。
【０１８６】
（ｏ）感熱層の形成−１
以下に示すように、上記で得られた平版印刷版用支持体に感熱層塗布液を塗布し、乾燥して平版印刷版原版を得た。
下記組成の感熱層塗布液を調製し、上記で得られた平版印刷版用支持体に、この感熱層塗布液をバーコーターを用いて、乾燥後の塗布量（感熱層塗布量）が０．７ｇ／ｍ^２ になるよう塗布し、オーブンを用いて１００℃で６０秒間乾燥して感熱層を形成させ、平版印刷版原版を得た。
【０１８７】
＜感熱層塗布液組成＞
・後述するマイクロカプセル液 ２５ｇ（固形分５ｇ）
・トリメチロールプロパントリアクリレート ３ｇ
・本明細書記載の赤外線吸収染料（Ｉ−３２） ０．３ｇ
・水 ６０ｇ
・１−メトキシ−２−プロパノール １ｇ
【０１８８】
＜マイクロカプセル＞
キシレンジイソシアネート４０ｇ、トリメチロールプロパンジアクリレート１０ｇ、アリルメタクリレートとブチルメタクリレートの共重合体（モル比７／３）１０ｇおよび界面活性剤（パイオニンＡ４１Ｃ、竹本油脂社製）０．１ｇを酢酸エチル６０ｇに溶解させて、油相成分とした。一方、ポリビニルアルコール（ＰＶＡ２０５、クラレ社製）の４％水溶液を１２０ｇ調製し、水相成分とした。油相成分および水相成分をホモジナイザーに投入し、１００００ｒｐｍで１０分間で乳化させた。その後、水を４０ｇ添加し、室温で３０分攪拌し、更に４０℃で３時間攪拌し、マイクロカプセル液を得た。得られたマイクロカプセル液の固形分濃度は２０質量％であり、マイクロカプセルの平均粒径は０．５μｍであった。
【０１８９】
（ｐ）感熱層の形成−２
サーマルポジタイプの画像記録層
上記のようにして得られたアルカリ金属ケイ酸塩処理後の平版印刷版用支持体上に、下記組成の下塗液を塗布し、８０℃で１５秒間乾燥し、塗膜を形成させた。乾燥後の塗膜の被覆量は１０ｍｇ／ｍ^２ であった。
【０１９０】
＜下塗液組成＞
・下記高分子化合物０．２ｇ
・メタノール１００ｇ
・水 １ｇ
【０１９１】
【化１０】

【０１９２】
更に、下記組成の感熱層塗布液を調製し、下塗りした平版印刷版用支持体に、この感熱層塗布液を乾燥後の塗布量（感熱層塗布量）が１．７ｇ／ｍ^２ になるよう塗布し、乾燥させて感熱層（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。
【０１９３】
＜感熱層塗布液組成＞
・ノボラック樹脂（ｍ−クレゾール／ｐ−クレゾール＝６０／４０、重量平均分子量７，０００、未反応クレゾール０．５質量％含有）１．０ｇ
・下記構造式で表されるシアニン染料Ａ０．１ｇ
・テトラヒドロ無水フタル酸０．０５ｇ
・ｐ−トルエンスルホン酸０．００２ｇ
・エチルバイオレットの対イオンを６−ヒドロキシ−β−ナフタレンスルホン酸にしたもの０．０２ｇ
・フッ素系界面活性剤（メガファックＦ−１７７、大日本インキ化学工業社製）０．０５ｇ
・メチルエチルケトン１２ｇ
【０１９４】
【化１１】

【０１９５】
１．平版印刷版用支持体表面の無機化合物層による被覆率および陽極酸化皮膜ポア径の観察
各平版印刷版原版について、現像処理後の非画像部の支持体表面を、走査型電子顕微鏡（Ｓ−９００、日立製作所社製）によって、加速電圧１２ｋＶ、蒸着なしの条件で、倍率１５万倍で観察し、撮影したＳＥＭ 写真から陽極酸化皮膜のポアが見えない範囲の面積率を求め被覆率とした。
【０１９６】
２．砂目形状特性の測定
（１）中波構造の平均開口径
ポアワイド処理後、無機化合物粒子の塗布前に、ＳＥＭを用いて支持体の表面を真上から倍率２０００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中波構造のピット（中波ピット）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。
【０１９７】
（２）小波構造の平均開口径
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写真において小波構造のピット（小波ピット）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。
【０１９８】
３．平版印刷版原版の感度
各平版印刷版原版をＣＲＥＯ社製プレートセッターＴｒｅｎｄｓｅｔｔｅｒ３２４４Ｆ（１９２チャンネルのマルチビーム搭載）で、各種パラメーター（Ｓｒ、Ｓｄ、ｂｍｓｌｏｐｅおよびｂｍｃｕｒｖｅ）の調整を行った後、２４００ｄｐｉで画像露光した。露光は、ドラム回転数および出力を段階的に変化させて行った。露光後、印刷機上で現像処理し、１％の網点を形成することができたエネルギー量（ｍＪ／ｃｍ^２）を平版印刷版原版の感度とした。結果は第１表に示した。
【０１９９】
４．耐刷性および汚れ性（ 払い）
露光した各平版印刷版原版について、印刷機に取り付け、湿し水を供給した後、インキを供給することにより印刷機上で現像処理を行い、引き続いて印刷を行った。ここで、印刷機としては小森印刷機社製の印刷機スプリントを用い、インキとしては大日本インキ化学工業社製のＧｅｏｓ墨を用い、湿し水としては富士写真フイルム（株）製の湿し水ＥＵ−３の水希釈液（１：１００）９０ｖｏｌ％とイソプロパノール１０ｖｏｌ％との混合物を用い、印刷する紙としては上質紙を用いた。上記条件で印刷を行い、画像部にインキが着肉しなくなるまで印刷できた枚数を測定して耐刷性の評価とした。耐刷結果は、基準とする枚数を１００％とし、それとの比較で％表示で第１表に示した。
【０２００】
また、平版印刷版を印刷機に取り付け、湿し水の供給とインキの供給と紙の供給とを同時に開始し、印刷物の非画像部に対応する領域におけるインキの付着がなくなり、汚れのない非画像部を形成するまでの損紙の枚数 （払い枚数）を、汚れ性の評価とした。損紙の枚数が少ないほど優れる。結果は、実際の損紙枚数で第１表に示した。
【０２０１】
第１表に示すように中波構造と小波構造が重畳していない比較例５〜９については無機化合物粒子のマイクロポアへの被覆率が低下し感度が低下したり、密着が不十分となり耐刷が低下した。無機化合物粒子の長径が小波平均開口径より大きい比較例１では実施例４に対して明らかに被覆率が低下し、感度、耐刷力が不十分となる。比較例３も同様の傾向となった。
また比較例２，４のように無機化合物の長径が陽極酸化皮膜のポア径よりも小さいと見かけ上被覆性は向上するが感度が大幅に低下してしまう。これに対して無機化合物の長径が陽極酸化皮膜のポア径よりも大きい実施例１０は感度および耐刷が向上した。
【０２０２】
【表１】

【０２０３】
【表２】

【０２０４】
５．サーマルポジタイプの画像記録層の露光および現像処理
平版印刷版原版を出力５００ｍＷ、波長８３０ｎｍビーム径１７μｍ（１／ｅ２ ）の半導体レーザーを装備したＣＲＥＯ社製ＴｒｅｎｎｄＳｅｔｔｅｒ３２４４を用いて主走査速度５ｍ／秒、版面エネルギー量１４０ｍＪ／ｃｍ^２ で像様露光した。その後、非還元糖と塩基とを組み合わせたＤ−ソルビット／酸化カリウムＫ_２ Ｏよりなるカリウム塩５．０質量％およびオルフィンＡＫ−０２（日信化学社製）０．０１５質量％を含有する水溶液１Ｌに所定の化合物を添加したアルカリ現像液を用いて現像処理を行った。現像処理は、上記アルカリ現像液を満たした自動現像機ＰＳ９００ＮＰ（富士写真フイルム（株）製）を用いて、現像温度２５℃、１２秒の条件で行った。現像処理が終了した後、水洗工程を経て、ガム（ＧＵ−７（１：１））等で処理して、製版が完了した平版印刷版を得た。
【０２０５】
６．サーマルポジタイプの画像記録層を有する平版印刷版原版の評価
上記で得られた平版印刷版原版の感度、耐刷、汚れ性について上記の条件で評価して結果を第２表に示した。なお実施例、比較例番号が同じものは、平版印刷版用支持体として第１表に示す同じ番号のものを用いた。
【０２０６】
【表３】

【０２０７】
【発明の効果】
本発明の平版印刷版用支持体および平版印刷版原版は、上記のように、サーマルタイプの平版印刷版原版として、小波構造、中波構造を備えた陽極酸化皮膜のマイクロポア上に、特定の無機化合物粒子を設け、好ましくは該無機化合物粒子を溶解し得る処理液で処理して該無機化合物粒子同志を融着させることにより、該無機化合物層による断熱効果とマイクロポアの空隙による断熱効果とを併有することができる。そのため感熱層からアルミニウム支持体への熱拡散が十分に抑制され、熱が効率よく画像形成に利用される。また、マイクロポア内への感熱層成分やインクの滲入が抑制されるので耐汚れ性が向上する。更に無機化合物粒子と陽極酸化皮膜を有するアルミニウム板との密着性が小波の平均開口径と無機化合物粒子の長径の限定により向上するため耐刷力が向上する。
したがって、本発明によれば、高感度で耐刷性に優れ、かつ、非画像部の汚れの発生が抑制されているため、サーマルポジタイプおよびサーマルネガタイプのいずれの平版印刷版原版にも好適に用いることができ、更には、機上現像 （無処理）タイプの平版印刷版原版に好適に用いることができる平版印刷版用支持体を得ることができ、極めて有用である。
【図面の簡単な説明】
【図１】本発明の平版印刷版用支持体の作成における機械粗面化処理に用いられるブラシグレイニングの工程の概念を示す側面図である。
【図２】本発明の平版印刷版用支持体の作成における交流を用いた電気化学的粗面化処理におけるラジアル型セルの一例を示す側面図である。
【図３】本発明の平版印刷版用支持体の作成における陽極酸化処理に用いられる陽極酸化処理装置の概略図である。
【図４】本発明の陽極酸化被膜のポア径と無機化合物粒子の長径との関係を示す模式図である。
【図５】本発明の支持体の砂目形状である小波構造の平均開口径と無機化合物粒子の長径との関係を示す模式図である。
【符号の説明】
１ アルミニウム板
２、４ ローラ状ブラシ
３ 研磨スラリー液
５、６、７、８ 支持ローラ
１１ アルミニウム板
１２ ラジアルドラムローラ
１３ａ、１３ｂ 主極
１４ 電解処理液
１５ 電解液供給口
１６ スリット
１７ 電解液通路
１８ 補助陽極
１９ａ、１９ｂ サイリスタ
２０ 交流電源
４０ 主電解槽
５０ 補助陽極槽
４１０ 陽極酸化処理装置
４１２ 給電槽
４１４ 電解処理槽
４１６ アルミニウム板
４１８、４２６ 電解液
４２０ 給電電極
４２２、４２８ ローラ
４２４ ニップローラ
４３０ 電解電極
４３２ 槽壁
４３４ 直流電源
１０１ 平版印刷版用支持体
１０２ アルミニウム板
１０３ 陽極酸化皮膜層
１０４ （陽極酸化皮膜層中の）マイクロポア
１０５ （マイクロポアの）内径
１０６ 無機化合物粒子[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a support for a lithographic printing plate and a lithographic printing plate precursor, and more specifically, an infrared laser lithographic plate for so-called direct plate making that can perform image recording by laser exposure based on digital signals from a computer or the like. The present invention relates to a support for a lithographic printing plate, a lithographic printing plate precursor used for the printing plate precursor, and a production method thereof.
[0002]
[Prior art]
In recent years, with the development of image forming technology, attention has been paid to the technology for making a plate directly without using a film manuscript by scanning a thin laser beam focused on the plate to form a character manuscript or image manuscript directly on the plate. Has been.
As such an image forming material, the infrared absorber present in the heat-sensitive layer exhibits its photothermal conversion action and generates heat upon exposure, and the exposed portion of the heat-sensitive layer is alkali-solubilized by the heat to form a positive image. Thermal type positive lithographic printing plate precursor, and heat and radical generators and acid generators generate radicals and acids, which causes radical polymerization reaction and acid crosslinking reaction to progress and insolubilize to form a negative image Thermal type negative lithographic printing plate precursors are listed. That is, in such thermal type image formation, heat is generated by the photothermal conversion substance in the heat sensitive layer by laser light irradiation, and the heat causes an image forming reaction.
[0003]
However, the aluminum support with a roughened anodized film has a much higher thermal conductivity than the heat-sensitive layer, and the heat generated near the interface between the heat-sensitive layer and the support is responsible for image formation. It will diffuse into the support before it is fully used.
As a result, the image forming reaction at the interface between the heat sensitive layer and the support becomes insufficient, leading to a decrease in sensitivity.
[0004]
First, in the positive heat-sensitive layer, when heat is diffused into the support and the alkali solubilization reaction becomes insufficient, a residual film is generated in the original non-image portion, and the sensitivity is lowered. Infrared absorbers having a photothermal conversion function are used, but these have low solubility due to their relatively large molecular weight, and are difficult to remove by adsorbing to the microscopic openings generated by anodization. There is also a problem that a residual film is easily generated in the development process.
On the other hand, in the negative heat-sensitive layer, heat is diffused inside the support, resulting in insufficient insolubilization of the developer in the heat-sensitive layer near the heat-sensitive layer support interface. There is a problem that the image flows or the image easily peels off during printing.
[0005]
In recent years, for example, a lithographic printing plate precursor that forms an image by coalescence of fine particles by heat has been proposed for a lithographic printing plate precursor that can be mounted on a printing machine as it is after exposure, In such a lithographic printing plate precursor, the diffusion of heat to the aluminum support directly leads to a reduction in sensitivity, and satisfactory printing durability cannot be obtained.
[0006]
In order to deal with these problems, an attempt was made to enlarge the micropores of the anodized film from the viewpoint of suppressing the diffusion of heat generated in the heat-sensitive layer to the aluminum support, and countermeasures against deterioration of the residual color residual film accompanying this were made. Attempts have been made to seal micropores such as a method of immersing in hot water or a hot aqueous solution containing an inorganic salt or an organic salt, or a method of exposing to a water vapor bath. (For example, see Patent Documents 1 and 2.)
However, the anti-fouling property can be improved by subjecting the enlarged micropores of the anodized film to the above-described sealing treatment, but the sealing cannot be completely performed and the level is still insufficient. The stain resistance refers to a property that stains hardly occur in a non-image area when printing is interrupted in the middle of printing and printing is resumed from a state where the planographic printing plate is left on the printing press.
[0007]
[Patent Document 1]
JP 2002-116548 A (page 8)
[Patent Document 2]
JP 2002-116549 A (second page)
[0008]
[Problems to be solved by the invention]
Accordingly, the object of the present invention is to overcome the above-mentioned drawbacks of the conventional techniques, efficiently use heat for image formation, have high sensitivity and excellent printing durability, and have excellent hydrophilicity and number of sheets to be paid. An object of the present invention is to provide a support for a lithographic printing plate used for a lithographic printing plate precursor in which occurrence of stains in an image area is suppressed.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors sealed an aluminum plate having the following specific microstructure obtained by roughening and anodizing with feather-like inorganic compound particles. When perforated, the covering property of feather-like particles was improved, and a lithographic printing plate support with improved adhesion was obtained, and the present invention was completed by finding that the above problems were solved.
That is, the present invention is as follows.
(1) A lithographic printing plate support obtained by subjecting an aluminum plate to a surface roughening treatment and an anodizing treatment, and has a medium wave structure with an average opening diameter of 0.5 to 5 μm and an average opening diameter of 0.01 on the surface. A roughened structure is formed by superimposing a wave structure of about 0.2 μm, and is larger than the surface average pore diameter of the anodized film on the anodized film and has an average aperture diameter of the wave structure existing on the surface A lithographic printing plate support in which inorganic compound particles having the following average major axis are present.
(2) The lithographic printing plate support according to (1), wherein the inorganic compound particles are fixed with a compound containing at least one selected from the group consisting of fluorine, phosphorus and silicon.
(3) The lithographic printing plate support according to (1) or (2), wherein the roughened structure further overlaps a large wave structure having an average wavelength of 5 to 100 μm.
(4) A lithographic printing plate precursor comprising a lithographic printing plate support according to any one of the above (1) to (3) provided with a heat-sensitive layer that can be developed with post-exposure water.
[0010]
FIG. 4 is a schematic cross-sectional view of the lithographic printing plate support of the present invention. As shown in FIG. 4, the lithographic printing plate support 101 of the present invention has an inner diameter of the micropore 104 in the anodized film layer 103 on the support surface formed by providing the anodized film layer 103 on the aluminum plate 102. Inorganic compound particles 106 having a major axis larger than 105 are included.
The opening of the micropore 104 existing in the anodized film 103 is blocked by inorganic compound particles 106 described later, but has a void inside. In the case of the conventional sealing treatment, the micropores present in the anodized film are filled with the product through the reaction by boehmite treatment, and almost no voids are left. The present invention is greatly different from the conventional sealing treatment in that only the opening of the micropore is sealed and a void remains inside.
[0011]
Further, FIG. 5 shows the relationship between the surface irregularity shape of the support of the present invention and the size of the inorganic compound particles. Even inorganic compound particles having a longer diameter larger than the micropore diameter are not desirable because the shape of the small wave will be crushed if it is larger than the roughened small wave structure. When the relationship between the average opening diameter of the small waves satisfies the following, the inorganic compound particles trace all over the surface while tracing the shape of the small waves, and the inorganic compound particles are coated on the aluminum plate by the physical anchor effect. Can be firmly attached.
[0012]
The lithographic printing plate support of the present invention, as described above, by providing specific inorganic compound particles on the anodized film provided on the aluminum plate having a structure in which the medium wave structure and the small wave structure are superimposed, The pores of the micropores are maintained, exhibiting a heat insulating effect, heat diffusion from the heat sensitive layer to the aluminum plate support is sufficiently suppressed, and heat is efficiently used for image formation. Further, since the penetration of the heat sensitive layer component and ink into the micropores is suppressed, the stain resistance is improved. Further, since the adhesion between the inorganic compound particles and the aluminum plate having the anodized film is improved by limiting the average opening diameter of the small wave and the long diameter of the inorganic compound particles, the printing durability is improved. According to the present invention, there is provided a support for a lithographic printing plate precursor that can be suitably used for a lithographic printing plate precursor having high sensitivity, excellent printing durability, and suppression of occurrence of stains in non-image areas. .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
[Support for lithographic printing plate]
<Surface grain shape>
The lithographic printing plate support of the present invention has a grained shape on the surface with a structure in which a medium wave structure with an average opening diameter of 0.5 to 5 μm and a small wave structure with an average opening diameter of 0.01 to 0.2 μm are superimposed. It is characterized by that. In the present invention, the medium wave structure having an average opening diameter of 0.5 to 5 μm has a function of holding the image recording layer mainly by an anchor (throwing) effect and imparting printing durability. When the average opening diameter of the pits having a medium wave structure is less than 0.5 μm, the adhesiveness with the image recording layer provided on the upper layer is lowered, and the printing durability of the lithographic printing plate may be lowered. Further, when the average opening diameter of the pits having the medium wave structure exceeds 5 μm, the number of pit boundary portions serving as anchors is reduced, so that the printing durability may also be lowered.
[0014]
The small wave structure having an average opening diameter of 0.01 to 0.2 μm superimposed on the medium wave structure mainly plays a role of improving stain resistance. By combining the medium wave structure with the small wave structure, when dampening water is supplied to the lithographic printing plate during printing, a water film is uniformly formed on the surface of the lithographic printing plate, thereby suppressing the occurrence of stains on the non-image area. it can. When the average opening diameter of the pits having the small wave structure is less than 0.01 μm, a large effect may not be obtained in forming a water film. On the other hand, when the average opening diameter of the pits having the small wave structure exceeds 0.2 μm, the medium wave structure is destroyed, and the effect of improving the printing durability by the above-described medium wave structure may not be obtained.
[0015]
With this small wave structure, not only the opening diameter of the pit but also the depth of the pit can be controlled to obtain even better stain resistance. That is, it is preferable that the average of the ratio of the depth to the opening diameter of the small wave structure is 0.2 or more. As a result, the uniformly formed water film is reliably held on the surface, and the stain resistance of the surface of the non-image part is maintained for a long time.
[0016]
The structure in which the medium wave structure and the small wave structure are superimposed may be a structure in which the large wave structure having an average wavelength of 5 to 100 μm is further superimposed. This large wave structure has the effect of increasing the amount of water retained on the surface of the non-image part of the lithographic printing plate. The more water is retained on the surface, the less the surface of the non-image area is affected by contamination in the atmosphere, and a non-image area that is less likely to get dirty even when the plate is left in the middle of printing can be obtained. Further, when the large wave structure is superimposed, it becomes easy to visually confirm the amount of dampening water given to the printing plate during printing. That is, the plate inspection property of the planographic printing plate is excellent. If the average wavelength of the large wave structure is less than 5 μm, there may be no difference from the medium wave structure. If the average wavelength of the large wave structure exceeds 100 μm, the exposed non-image area may appear glaring after exposure and development, which may impair plate inspection. The average wavelength of the large wave structure is preferably 10 to 80 μm.
[0017]
In the lithographic printing plate support of the present invention, the average opening diameter of the medium wave structure on the surface, the average opening diameter of the small wave structure and the average ratio of the depth to the opening diameter, and the measurement method of the average wavelength of the large wave are as follows: It is as follows.
[0018]
(1) Average opening diameter of medium wave structure
The surface of the support was photographed at a magnification of 2000 times from directly above using an electron microscope, and in the obtained electron micrograph, at least 50 pits (medium wave pits) having a medium wave structure in which the periphery of the pits are connected in a ring shape. Extract, read the diameter and use it as the opening diameter, and calculate the average opening diameter. The same method is used for a structure with a large wave structure superimposed. In addition, in order to suppress variation in measurement, it is possible to perform equivalent circle diameter measurement using commercially available image analysis software. In this case, the electron micrograph is captured by a scanner, digitized, and binarized by software, and then an equivalent circle diameter is obtained.
As a result of measurement by the present inventor, the result of visual measurement and the result of digital processing showed almost the same value. The same applies to the structure in which the large wave structure is superimposed.
[0019]
(2) Average aperture diameter of small wave structure
Using a high-resolution scanning electron microscope (SEM), the surface of the support was photographed from directly above at a magnification of 50000 times, and at least 50 small-wave structure pits (small-wave pits) were extracted from the obtained SEM photograph. Is read as the opening diameter, and the average opening diameter is calculated.
[0020]
(3) Average ratio of depth to aperture diameter of small wave structure
The average ratio of the depth to the aperture diameter of the wavelet structure is obtained by photographing the fracture surface of the support at a magnification of 50000 times using a high-resolution SEM, extracting at least 20 wavelet pits from the obtained SEM photograph, And the depth are read to find the ratio and the average value is calculated.
[0021]
(4) Average wavelength of large wave structure
Two-dimensional roughness measurement is performed with a stylus type roughness meter, and the average peak spacing Sm defined in ISO 4287 is measured five times, and the average value is taken as the average wavelength (average aperture diameter).
[0022]
<Surface treatment>
The lithographic printing plate support of the present invention is one in which the above-mentioned surface grain shape is formed on the surface of the aluminum plate by subjecting the aluminum plate described later to surface treatment. The lithographic printing plate support of the present invention is obtained by subjecting an aluminum plate to a surface roughening treatment and an anodizing treatment, but the production process of this support is not particularly limited, and the surface roughening treatment and the anodizing treatment are performed. Various processes other than the above may be included. Later, a representative example of a method for forming the above-described surface grain shape will be described.
[0023]
[Inorganic compound particles]
<Formation of inorganic compound particle layer>
A feature of the present invention is to have inorganic compound particles having a specific relationship with the above-mentioned specific grain shape on a roughened and anodized support of an aluminum plate. ₂ O ₃ TiO ₂ , SiO ₂ , ZrO ₂ However, it is not limited to these. The particles used in the inorganic compound particle layer have an average major axis larger than the pore diameter of the anodized film and not more than the average aperture diameter of the small wave structure obtained by roughening. The value of the average major axis is not particularly limited as long as the above is satisfied, but an average major axis of 8 to 800 nm, preferably an average major axis of 20 to 500 nm, more preferably an average major axis of 50 to 150 nm is preferable. Further, in order to improve the film property when the particle layer is formed, it is desirable that the aspect ratio which is the ratio of the average major axis to the average minor axis is larger, and it is preferably 5 or more. When the average particle size including the minor axis and the major axis of the particles is 8 nm or more, there is little possibility that the particles enter the micropores existing in the anodized film, and the effect of increasing the sensitivity is sufficiently obtained. It is done.
The average major axis of the inorganic compound particles is equal to or smaller than the average aperture diameter of the small wave structure obtained by roughening, and more desirably equal to or smaller than ½ of the average aperture diameter of the small wave.
The inorganic compound particle layer of the present invention may cover the entire surface of the anodic oxide coating, but it may not cover a single layer but may cover a part thereof, or may be a porous coating, The rate is preferably 20% to 100% or more, more preferably 60% to 100%.
[0024]
The methods for measuring the major axis and minor axis of the inorganic compound particles used in the present invention are as follows. Unless otherwise specified, the average major axis and the average minor axis are referred to as the major axis and minor axis, respectively. As a specific measuring method, a suspension of inorganic compound particles (solid content concentration: 0.2%) is dropped on a preparation, dried in a standing state, and then vapor-deposited and fixed on the surface. The surface of the sample thus prepared was observed with a scanning electron microscope (S-900, manufactured by Hitachi, Ltd.) at an acceleration voltage of 12 kV and a magnification of 120,000 times. The shortest diameter was measured, and the average value of each was calculated as the major axis and minor axis.
[0025]
The inorganic compound particles used in the present invention preferably have a thermal conductivity of 60 W / (m · K) or less, more preferably 40 W / (m · K) or less in a state where a porous layer is formed. It is preferably 0.3 to 10 W / (m · K) or less.
When the thermal conductivity is 60 W / (m · K) or less, the thermal diffusion to the aluminum support is sufficiently suppressed, and the effect of increasing the sensitivity is sufficiently obtained.
As the kind of inorganic compound particles, Al ₂ O ₃ TiO ₂ , SiO ₂ And ZrO ₂ Can be used alone or in combination of two or more.
[0026]
The method for providing the inorganic compound particle layer is not particularly limited, but the simplest method is a method by coating. An inorganic compound particle layer can be easily formed by coating an aqueous solution or an organic solvent solution containing the inorganic compound particles on the support surface by a coating method such as a wheeler coating method or a bar coating method and then drying.
Further, a method of subjecting the aluminum support to electrolytic treatment using an electrolytic solution containing the inorganic compound particles and using direct current or alternating current is preferable. Examples of the alternating current waveform used in the electrolytic treatment include a sine wave, a rectangular wave, a triangular wave, and a trapezoidal wave. In addition, the frequency of the alternating current is preferably 30 to 200 Hz, more preferably 40 to 120 Hz, from the viewpoint of the cost of manufacturing the power supply device. When a trapezoidal wave is used as the waveform of the alternating current, the time tp until the current reaches a peak from 0 is preferably 0.1 to 2 msec, and more preferably 0.3 to 1.5 msec. If the tp is less than 0.1 msec, the impedance of the power supply circuit is affected, and a large power supply voltage is required at the time of rising of the current waveform, which may increase the equipment cost of the power supply.
[0027]
As inorganic compound particles, Al ₂ O ₃ TiO ₂ , SiO ₂ And ZrO ₂ The single particles or a mixture of two or more of them may be used. The compound may be a combination of two or more elements, or a mixture thereof. The electrolytic solution is obtained, for example, by suspending in water or the like so that the content of the inorganic compound particles is 0.01 to 20% by mass of the whole. The electrolytic solution can be adjusted in pH by, for example, adding sulfuric acid in order to charge the charge positively or negatively. The electrolytic treatment is performed, for example, using direct current, using an aluminum support as a cathode, and using the above electrolytic solution at a voltage of 10 to 200 V for 1 to 600 seconds.
According to this method, it is possible to easily close the opening while leaving a void inside the micropore existing in the anodized film.
[0028]
<Fixing treatment of inorganic compound particle layer>
In the method for producing a lithographic printing plate support according to the present invention, it is desirable that after the inorganic compound particle layer is provided, the particle layer is fixed to the anodized film layer.
The particle layer fixing treatment is a treatment liquid capable of dissolving the inorganic compound particles (hereinafter also simply referred to as a fixation treatment liquid), and the treatment is performed with the treatment liquid to partially weld the inorganic compound particles and the anodized film layer. , They are bound together in a solid state. Of course, the processing solution that can be dissolved is used, but it is not completely dissolved, but the concentration and use conditions of the processing solution are adjusted so that the anodic oxide coating and inorganic compound particles are dissolved and bonded to each other to a desirable degree. .
The treatment liquid capable of dissolving the inorganic compound particles is not particularly limited, but an aqueous solution of a compound containing at least one of fluorine, phosphorus and silicon is preferable. As a result, a lithographic printing plate support having excellent stain resistance when obtained as a lithographic printing plate can be obtained.
[0029]
Preferred examples of the fluorine compound used in the present invention include metal fluorides.
Specifically, for example, sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, sodium hexafluorozirconium, hexafluorozirconium potassium, sodium hexafluorotitanate, potassium hexafluorotitanate, hexafluorozirconium hydrogen acid , Hexafluorotitanium hydrogen acid, hexafluorozirconium ammonium, ammonium hexafluorotitanate, hexafluorosilicic acid, nickel fluoride, iron fluoride, phosphorous phosphate, ammonium fluoride phosphate.
[0030]
Moreover, as a phosphate used for this invention, metal phosphates, such as an alkali metal and an alkaline-earth metal, are mentioned, for example.
Specifically, for example, zinc phosphate, aluminum phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, monoammonium phosphate, monopotassium phosphate, monosodium phosphate, dihydrogen phosphate Potassium, dipotassium hydrogen phosphate, calcium phosphate, sodium ammonium hydrogen phosphate, magnesium hydrogen phosphate, magnesium phosphate, ferrous phosphate, ferric phosphate, sodium dihydrogen phosphate, sodium phosphate, hydrogen phosphate Disodium, lead phosphate, diammonium phosphate, calcium dihydrogen phosphate, lithium phosphate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, ammonium phosphomolybdate, sodium phosphomolybdate; sodium phosphite , Tripolyphosphate Potassium, and sodium pyrophosphate. Among these, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate are preferable.
[0031]
Moreover, as a silicate compound used for this invention, a silicic acid and a silicate are mentioned, Among these, an alkali metal silicate is mentioned suitably. Specific examples include sodium silicate, potassium silicate, and lithium silicate. Of these, sodium silicate and potassium silicate are preferable. Examples of sodium silicate include No. 3 sodium silicate, No. 2 sodium silicate, No. 1 sodium silicate, sodium orthosilicate, sodium sesquisilicate, and sodium metasilicate. Examples of potassium silicate include No. 1 potassium silicate. An aluminosilicate containing aluminum or a borosilicate containing boric acid can also be used. Examples of the silicic acid include orthosilicic acid, metasilicic acid, metadisilicic acid, metatrisilicic acid, and metatetrasilicic acid.
[0032]
The concentration of each compound in the fixing treatment liquid is preferably 0.01% by mass or more, and 0.05% by mass or more in terms of the fixing point of inorganic compound particles to the anodized film layer for the fluorine compound. More preferably, it is more preferably 0.1% by mass or more, and in terms of dirtiness, it is preferably 10% by mass or less, more preferably 1% by mass or less. It is particularly preferably 5% by mass or less.
Further, the silicic acid compound is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 1% by mass or more in terms of dirtiness. Further, in terms of printing durability, the content is preferably 10% by mass or less, more preferably 7% by mass or less, and particularly preferably 5% by mass or less.
When the fixing treatment liquid contains both a fluorine compound and a silicate compound, the ratio of each compound in the fixing treatment liquid is not particularly limited, but the mass ratio of the fluorine compound and the silicate compound is 5:95 to The ratio is preferably 95: 5, more preferably 20:80 to 80:20.
[0033]
Further, the aqueous solution containing at least one of a fluorine compound, a phosphoric acid compound, and a silicic acid compound may contain an appropriate amount of sodium hydroxide, potassium hydroxide, lithium hydroxide or the like in order to adjust the pH. Good. Of these, sodium hydroxide and potassium hydroxide are preferable. It may contain sulfuric acid and nitric acid.
Moreover, the aqueous solution containing a fluorine compound, a phosphoric acid compound, and a silicic acid compound may contain an alkaline earth metal salt or a Group 4 (Group IVB) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Is mentioned. Examples of the Group 4 (Group IVB) metal salt include aluminum chloride, titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride oxide, zirconium dioxide, Examples thereof include zirconium oxychloride and zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVB) metal salts are used alone or in combination of two or more.
[0034]
Further, the temperature of the fixing treatment liquid is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, preferably 100 ° C. or lower, more preferably 80 ° C. or lower.
[0035]
The method of treatment with an aqueous solution containing at least one of a fluorine compound, a phosphoric acid compound, and a silicic acid compound is not particularly limited, and examples thereof include an immersion method and a spray method. These may be used alone or in combination, or may be used in combination of two or more.
Of these, the dipping method is preferred. When processing using the immersion method, the processing time is preferably 1 second or longer, more preferably 3 seconds or longer, more preferably 600 seconds or shorter, and 120 seconds or shorter. More preferred.
[0036]
As described above, the lithographic printing plate support of the present invention uses a support obtained by roughening an aluminum plate and providing an anodized film, and providing inorganic compound particles on the anodized film, By treating the compound particles with a treatment solution capable of dissolving the compound particles and fusing the inorganic compound particles together, it is possible to have both the heat insulation effect by the inorganic compound particles and the heat insulation effect by the micropore voids.
[0037]
As a desirable mode of the present invention, it comprises a “thermosensitive composition” which contains a photothermal conversion substance on the lithographic printing plate support of the present invention described above and forms an image by heat generated in an exposed portion, and is specially developed It is desirable to provide a heat-sensitive layer that can be developed with post-exposure ink and / or water, which is called “non-process type”.
[0038]
[Aluminum support]
<Aluminum plate (rolled aluminum)>
The aluminum plate used as the substrate of the above-described lithographic printing plate support of the present invention is made of a metal whose main component is dimensionally stable aluminum, that is, aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic film or paper on which aluminum or an aluminum alloy is laminated or vapor-deposited can also be used. Furthermore, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 can also be used.
[0039]
In the following description, various substrates made of aluminum or an aluminum alloy mentioned above or various substrates having a layer made of aluminum or an aluminum alloy are collectively used as an aluminum plate. The foreign elements that may be contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium, and the content of the foreign elements in the alloy is 10% by mass or less. It is.
[0040]
In the present invention, it is preferable to use a pure aluminum plate. However, it is difficult to produce completely pure aluminum in terms of refining technology, so it may contain a slightly different foreign element. Thus, the composition of the aluminum plate used in the present invention is not specified, and aluminum alloy plates such as JIS A1050, JIS A1100, JIS A3005, and internationally registered alloy 3103A, which are conventionally publicly known materials, are known. Can be used as appropriate. The thickness of the aluminum plate used in the present invention is 0. 1mm-0. It is about 6 mm. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the user's desire.
[0041]
The aluminum support used in the method for producing a lithographic printing plate support of the present invention and the lithographic printing plate support is obtained by providing an anodic oxide film on the aluminum plate. Various processes other than the anodizing treatment may be included.
[0042]
<Roughening treatment (graining treatment)>
The lithographic printing plate support of the present invention having the specific grain shape described above is formed by the following surface treatment as an example.
That is, the above-mentioned aluminum plate is grained to a more preferable shape.
Examples of the graining method include mechanical graining (mechanical roughening), chemical etching, and electrolytic grain as disclosed in JP-A-56-28893. Furthermore, electrochemical graining (electrochemical roughening) in which electrochemical graining is carried out in hydrochloric acid electrolyte or nitric acid electrolyte, and the aluminum brush is ground with a metal wire. Mechanical graining methods such as a ball grain method in which the aluminum surface is grained with an abrasive and a brush grain method in which the surface is grained with a nylon brush and an abrasive can be used. These graining methods can be used alone or in combination.
[0043]
<Electrochemical roughening treatment>
In the electrochemical surface roughening treatment, an electrolytic solution used for the electrochemical surface roughening treatment using a normal alternating current can be used. Among them, the concavo-convex structure characteristic of the present invention can be formed on the surface by using an electrolytic solution mainly composed of hydrochloric acid or nitric acid. As the electrolytic surface roughening treatment in the present invention, it is preferable to perform the first and second electrolytic treatments with an alternating waveform current in an acidic solution before and after the cathodic electrolytic treatment. By cathodic electrolysis, hydrogen gas is generated on the surface of the aluminum plate and smut is generated to make the surface state uniform, and it is possible to obtain a uniform electrolytic surface during the subsequent electrolysis with an alternating waveform current. . This electrolytic surface roughening treatment can be performed according to, for example, an electrochemical grain method (electrolytic grain method) described in Japanese Patent Publication No. 48-28123 and British Patent No. 896,563. This electrolytic grain method uses a sinusoidal alternating current, but it may be performed using a special waveform as described in JP-A-52-58602.
[0044]
Various electrolyzers and power sources have been proposed, but those described in known literatures can also be used.
As the acidic solution that is an electrolytic solution, various known electrolytic solutions can be used in addition to nitric acid and hydrochloric acid.
[0045]
An aqueous solution mainly composed of hydrochloric acid or nitric acid is an aqueous solution of hydrochloric acid or nitric acid having a concentration of 1 to 100 g / L. At least one of the hydrochloric acid compounds having hydrochloric acid ions can be used by adding in a range from 1 g / L to saturation. Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, a silica, may melt | dissolve in the aqueous solution which has hydrochloric acid or nitric acid as a main component. Preferably, a solution obtained by adding aluminum chloride, aluminum nitrate or the like to an aqueous solution of hydrochloric acid or nitric acid having a concentration of 0.5 to 2% by mass so that aluminum ions are 3 to 50 g / L is preferably used.
[0046]
Further, by adding and using a compound capable of forming a complex with Cu, uniform graining is possible even for an aluminum plate containing a large amount of Cu. Examples of the compound capable of forming a complex with Cu include ammonia; hydrogen atom of ammonia such as methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, cyclohexylamine, triethanolamine, triisopropanolamine, EDTA (ethylenediaminetetraacetic acid). And amines obtained by substituting with a hydrocarbon group (aliphatic, aromatic, etc.); metal carbonates such as sodium carbonate, potassium carbonate, potassium hydrogen carbonate and the like. In addition, ammonium salts such as ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium phosphate, and ammonium carbonate are also included. The temperature is preferably 10-60 ° C, more preferably 20-50 ° C.
[0047]
The AC power supply wave used for the electrochemical surface roughening treatment is not particularly limited, and a sine wave, a rectangular wave, a trapezoidal wave, a triangular wave or the like is used, but a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal wave is particularly preferable. In this trapezoidal wave, the time (TP) until the current reaches a peak from zero is preferably 1 to 3 msec. If it is less than 1 msec, processing irregularities such as chatter marks that occur perpendicular to the traveling direction of the aluminum plate tend to occur. When TP exceeds 3 msec, especially when a nitric acid electrolyte is used, it is easily affected by trace components in the electrolyte typified by ammonium ions and the like that spontaneously increase by electrolytic treatment, and uniform graining is performed. It becomes hard to be broken. As a result, the stain resistance tends to decrease when a lithographic printing plate is obtained.
[0048]
A duty ratio of trapezoidal wave alternating current of 1: 2 to 2: 1 can be used. However, as described in Japanese Patent Laid-Open No. 5-195300, in an indirect power feeding method in which no conductor roll is used for aluminum, a duty is used. A ratio of 1: 1 is preferred. A trapezoidal AC frequency of 0.1 to 120 Hz can be used, but 50 to 70 Hz is preferable in terms of equipment. When the frequency is lower than 50 Hz, the carbon electrode of the main electrode is easily dissolved, and when the frequency is higher than 70 Hz, it is easily affected by an inductance component on the power supply circuit, and the power supply cost is increased.
[0049]
One or more AC power supplies can be connected to the electrolytic cell. For the purpose of controlling the current ratio between the anode and cathode of alternating current applied to the aluminum plate facing the main electrode, uniform graining, and dissolving the carbon of the main electrode, an auxiliary anode is installed, It is preferable to divert part of the alternating current. In FIG. 2, 11 is an aluminum plate, 12 is a radial drum roller, 13a and 13b are main poles, 14 is an electrolytic treatment solution, 15 is an electrolyte supply port, and 16 is a slit. , 17 is an electrolyte passage, 18 is an auxiliary anode, 19a and 19b are thyristors, 20 is an AC power source, 40 is a main electrolytic cell, and 50 is an auxiliary anode cell. An anodic reaction that acts on the aluminum plate facing the main electrode by diverting a part of the current value as a direct current to an auxiliary anode provided in a tank separate from the two main electrodes via a rectifier or switching element It is possible to control the ratio between the current value for the current and the current value for the cathode reaction. On the aluminum plate facing the main electrode, the ratio of the amount of electricity involved in the anodic reaction and the cathodic reaction (the amount of electricity at the time of cathode / the amount of electricity at the time of anode) is preferably 0.3 to 0.95.
[0050]
As the electrolytic cell, electrolytic cells used for known surface treatments such as a vertical type, a flat type, and a radial type can be used, but a radial type electrolytic cell as described in JP-A-5-195300 is particularly preferable. . The electrolytic solution passing through the electrolytic cell may be parallel to the traveling direction of the aluminum web or may be a counter.
[0051]
(Nitric acid electrolysis) Pits having an average opening diameter of 0.5 to 5 μm can be formed by electrochemical surface roughening using an electrolytic solution mainly composed of nitric acid. However, when the amount of electricity is relatively large, the electrolytic reaction is concentrated, and honeycomb pits exceeding 5 μm are also generated. In order to obtain such a grain, the total amount of electricity involved in the anode reaction of the aluminum plate at the time when the electrolytic reaction is completed is 1 to 1000 C / dm. ² Is preferably 50 to 300 C / dm. ² It is more preferable that The current density at this time is 20 to 100 A / dm. ² Is preferred. Further, when a high concentration or high temperature nitric acid electrolytic solution is used, a small wave structure having an average opening diameter of 0.2 μm or less can be formed.
[0052]
(Hydrochloric acid electrolysis) Since hydrochloric acid itself has a strong ability to dissolve aluminum, it is possible to form fine irregularities on the surface with only slight electrolysis. These fine irregularities have an average opening diameter of 0.01 to 0.2 μm and are uniformly generated on the entire surface of the aluminum plate. In order to obtain such a grain, the total amount of electricity involved in the anode reaction of the aluminum plate at the time when the electrolytic reaction is completed is 1 to 100 C / dm. ² It is preferable that it is 20-70 C / dm. ² It is more preferable that The current density at this time is 20 to 50 A / dm. ² Is preferred.
[0053]
In such an electrochemical surface roughening treatment with an electrolyte mainly composed of hydrochloric acid, the total amount of electricity involved in the anode reaction is set to 400 to 1000 C / dm. ² It is possible to simultaneously form a large crater-like undulation by increasing the crater shape, but in this case, an average opening diameter of 0.01 to 0.4 μm is superimposed on the crater-like undulation having an average opening diameter of 10 to 30 μm. Fine irregularities are generated on the entire surface. Therefore, in this case, since the medium wave structure with an average opening diameter of 0.5 to 5 μm cannot be superimposed, the grain shape of the surface that is a feature of the present invention cannot be made.
[0054]
The aluminum plate is preferably subjected to cathodic electrolysis treatment during the first and second electrolytic surface-roughening treatments performed in the electrolytic solution such as nitric acid and hydrochloric acid. By this cathodic electrolysis treatment, smut is generated on the surface of the aluminum plate, and hydrogen gas is generated to enable more uniform electrolytic surface roughening treatment. The cathodic electrolysis is preferably performed in an acidic solution with a cathode electric quantity of 3 to 80 C / dm. ² , More preferably 5-30 C / dm ² Done in Cathode electricity is 3 C / dm ² If it is less than 80, the smut adhesion amount may be insufficient, and 80 C / dm. ² If it exceeds 1, the amount of smut adhesion may become excessive, which is not preferable. Further, the electrolytic solution may be the same as or different from the solution used in the first and second electrolytic surface roughening processes.
[0055]
Among them, the method for producing a grainy surface suitably used in the present invention is an electrochemical method in which graining is chemically performed in a hydrochloric acid electrolyte or a nitric acid electrolyte. The preferred amount of electricity is 50 to 400 C / dm when the anode is charged. ² It is. More specifically, for example, in an electrolytic solution containing 0.1 to 50% by mass of hydrochloric acid or nitric acid, the temperature is 20 to 100 ° C., the time is 1 second to 30 minutes, and the current density is 10 to 100 A / dm. ² It is performed using direct current or alternating current under the following conditions. Electrochemical roughening is suitable for improving the adhesion between the heat-sensitive layer and the substrate because it is easy to provide fine irregularities on the surface.
[0056]
By this roughening, crater-like or honeycomb-like pits having an average diameter of about 0.5 to 20 μm can be generated on the surface of the aluminum plate at an area ratio of 30 to 100%. The provided pits have the effect of improving the resistance to smearing of the non-image area of the printing plate and the printing durability. In the electrochemical treatment, the amount of electricity necessary to provide sufficient pits on the surface, that is, the product of the current and the time during which the current is applied is an important condition in electrochemical roughening. From the viewpoint of energy saving, it is desirable that sufficient pits can be formed with a smaller amount of electricity. The surface roughness after the roughening treatment is such that the arithmetic average roughness (Ra) measured at a cut-off value of 0.8 mm and an evaluation length of 3.0 mm in accordance with JIS B0601-1994 is 0.2-0. It is preferably 7 μm. Up
The electrochemical roughening can be used in combination with electrochemical roughening under different conditions or mechanical roughening.
[0057]
<Etching treatment>
The grained aluminum plate is chemically etched with acid or alkali.
When an acid is used as an etching agent, it takes time to destroy the fine structure, which is industrially disadvantageous, but this problem can be improved by using an alkali as the etching agent.
The alkali agent suitably used in the present invention is not particularly limited, and examples thereof include caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, and lithium hydroxide.
The conditions of the alkali etching treatment are not particularly limited, but the alkali concentration is preferably 1 to 50% by mass, the alkali temperature is preferably 20 to 100 ° C., and the aluminum dissolution amount is 0.01 to 20 g / m ² Preferably, 0.1 to 5 g / m ² It is more preferable that
[0058]
After performing the etching process, pickling (desmut) is performed to remove dirt (smut) remaining on the surface. Examples of the acid used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and borohydrofluoric acid. In particular, as a method for removing smut after the electrochemical surface roughening treatment, it is preferable to use 15 to 65 mass% sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739. Examples thereof include a contact method and an alkali etching method as described in JP-B-48-28123.
[0059]
<Anodizing treatment>
The aluminum plate treated as described above is further subjected to anodizing treatment. The anodizing treatment can be performed by a method conventionally used in this field. Specifically, when direct current or alternating current is applied to an aluminum plate in an aqueous solution or non-aqueous solution of sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc., alone or in combination of two or more. An anodized film can be formed on the surface of the aluminum plate.
[0060]
Under the present circumstances, the component normally contained at least by Al alloy plate, an electrode, tap water, groundwater, etc. may be contained in electrolyte solution. Furthermore, the 2nd, 3rd component may be added. Examples of the second and third components herein include metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; Cation such as ammonium ion; anion such as nitrate ion, carbonate ion, chloride ion, phosphate ion, fluoride ion, sulfite ion, titanate ion, silicate ion, borate ion, etc., 0 to 10,000 ppm It may be contained at a concentration of about.
[0061]
The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be determined unconditionally. In general, however, the electrolyte concentration is 1 to 80% by mass, the solution temperature is 5 to 70 ° C., and the current density is 0.5. ~ 60A / dm ² A voltage of 1 to 100 V and an electrolysis time of 10 to 200 seconds are appropriate.
Among these anodizing treatments, a method of anodizing at a high current density in a sulfuric acid electrolyte solution described in British Patent 1,412,768, U.S. Pat. No. 3,511,661. The method of anodizing phosphoric acid as an electrolytic bath is particularly preferable.
[0062]
In the present invention, the thickness of the anodized film is preferably 0.3 to 10 μm. If the thickness is less than 0.3 μm, the plate tends to be damaged. On the other hand, if it exceeds 10 μm, a large amount of electric power is required for production, which is economically disadvantageous. The thickness of the anodized film is more preferably from 0.4 to 2 μm, particularly preferably from 0.6 to 1.5 μm.
[0063]
<Pore wide processing>
The aluminum support provided with the anodized film as described above may be subjected to pore-wide (PW) treatment for the purpose of adjusting the porosity of the anodized film to a suitable range, if necessary.
This treatment is performed by immersing in an acid aqueous solution or an alkali aqueous solution in order to adjust the micropore diameter of the anodized film to, for example, 8 to 500 nm, preferably 10 to 150 nm.
[0064]
An example of a method for measuring the diameter of the micropore after the anodizing treatment or after further pore-wide treatment is as follows.
Using a high-resolution scanning electron microscope (SEM), the surface of the support was photographed from directly above at a magnification of 50000 times, and at least 50 micropores were extracted from the obtained SEM photograph. The average diameter is calculated.
[0065]
The acid aqueous solution is preferably an aqueous solution of sulfuric acid, phosphoric acid or a mixture thereof.
The concentration of the acid aqueous solution is preferably 10 to 500 g / L, and more preferably 20 to 100 g / L. The temperature of the acid aqueous solution is preferably 10 to 90 ° C, and more preferably 40 to 70 ° C. The immersion time in the aqueous acid solution is preferably 10 to 300 seconds, and more preferably 30 to 120 seconds.
As the alkaline aqueous solution, an aqueous solution of sodium hydroxide, potassium hydroxide, lithium hydroxide or a mixture thereof is preferable. The pH of the alkaline aqueous solution is preferably 11 to 14, and more preferably 11.5 to 13.5. The temperature of the alkaline aqueous solution is preferably 10 to 90 ° C, and more preferably 20 to 60 ° C. The immersion time in the alkaline aqueous solution is preferably 5 to 300 seconds, and more preferably 10 to 60 seconds.
[0066]
In the lithographic printing plate support of the present invention, the porosity of the anodized film is preferably 20 to 70%, more preferably 30 to 60%, and particularly preferably 40 to 50%. preferable. When the porosity of the anodized film is 20% or more, the thermal diffusion to the aluminum support is sufficiently suppressed, and the effect of increasing the sensitivity is sufficiently obtained. When the porosity of the anodic oxide film is 70% or less, a problem that stains occur in the non-image area is less likely to occur.
[0067]
In the present invention, the aluminum plate is roughened and anodized as described above, and the surface has a medium wave structure with an average opening diameter of 0.5 to 5 μm and a small wave structure with an average opening diameter of 0.01 to 0.2 μm. Are formed on the surface of the anodized film, and the surface of the anodized film is larger than the surface pore diameter of the anodized film and has a major axis equal to or smaller than the average opening diameter of the small wave structure existing on the surface. The above-mentioned inorganic compound particle layer is formed so as to exist, and further treated with the above-described fixing treatment liquid. In the present invention, since an aluminum plate having a specific microstructure is sealed with inorganic compound particles, the particle coverage is improved and the adhesion is improved, so that the surface of the anodic oxide coating layer surface of the inorganic compound particle layer is improved. The rate is also high.
[0068]
<Hydrophilic surface treatment>
In the present invention, an inorganic compound particle layer is provided on an aluminum support, and after the particle layer fixing treatment, the surface of the aluminum support is further immersed in an aqueous solution containing one or more hydrophilic compounds. You may go. Preferred examples of the hydrophilic compound include polyvinyl phosphonic acid, a compound having a sulfonic acid group, a saccharide compound, and a silicate compound. Of these, polyvinylphosphonic acid and silicate compounds are preferred. Most preferred are silicate compounds.
[0069]
The compound having a sulfonic acid group includes an aromatic sulfonic acid, a formaldehyde condensate thereof, a derivative thereof, and a salt thereof.
Examples of the aromatic sulfonic acid include phenol sulfonic acid, catechol sulfonic acid, resorcinol sulfonic acid, benzene sulfonic acid, toluene sulfonic acid, lignin sulfonic acid, naphthalene sulfonic acid, acenaphthene-5-sulfonic acid, phenanthrene-2-sulfonic acid. Benzaldehyde-2 (or 3) -sulfonic acid, benzaldehyde-2,4 (or 3,5) -disulfonic acid, oxybenzylsulfonic acids, sulfobenzoic acid, sulfanilic acid, naphthionic acid, and taurine. Of these, benzenesulfonic acid, naphthalenesulfonic acid, and ligninsulfonic acid are preferable. Also preferred are formaldehyde condensates of benzene sulfonic acid, naphthalene sulfonic acid, and lignin sulfonic acid.
Furthermore, these may be used as sulfonates. For example, sodium salt, potassium salt, lithium salt, calcium salt, magnesium salt can be mentioned. Of these, sodium salts and potassium salts are preferred.
The pH of the aqueous solution containing the compound having a sulfonic acid group is preferably 4 to 6.5, and can be adjusted to the above pH range using sulfuric acid, sodium hydroxide, ammonia or the like.
[0070]
The saccharide compounds include monosaccharides and their sugar alcohols, oligosaccharides, polysaccharides, and glycosides.
Monosaccharides and sugar alcohols thereof include, for example, trioses such as glycerol and sugar alcohols thereof; tetroses such as treose and erythritol and sugar alcohols thereof; pentoses such as arabinose and arabitol and sugar alcohols thereof; glucose, sorbitol and the like Hexoses and sugar alcohols thereof; heptoses and sugar alcohols such as D-glycero-D-galactoheptose and D-glycero-D-galactoheptitol; octoses such as D-erythro-D-galactoctitol and Examples thereof include sugar alcohols; nonoses such as D-erythro-L-gluco-nonulose and sugar alcohols thereof.
Examples of oligosaccharides include disaccharides such as saccharose, trehalose, and lactose; and trisaccharides such as raffinose.
Examples of the polysaccharide include amylose, arabinan, cyclodextrin, and cellulose alginate.
[0071]
In the present invention, the “glycoside” refers to a compound in which a sugar moiety and a non-sugar moiety are bonded through an ether bond or the like.
Glycosides can be classified by non-sugar moieties. For example, alkyl glycoside, phenol glycoside, coumarin glycoside, oxycoumarin glycoside, flavonoid glycoside, anthraquinone glycoside, triterpene glycoside, steroid glycoside, mustard oil glycoside Can be mentioned.
Examples of the sugar moiety include the above-described monosaccharides and sugar alcohols thereof; oligosaccharides; polysaccharides. Among these, monosaccharides and oligosaccharides are preferable, and monosaccharides and disaccharides are more preferable.
Examples of preferable glycosides include compounds represented by the following formula (I).
[0072]
[Chemical 1]

[0073]
In the above formula (I), R represents an alkyl group, an alkenyl group or an alkynyl group having a straight chain or a branched chain having 1 to 20 carbon atoms.
Examples of the alkyl group having 1 to 20 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, Nonadecyl and eicosyl groups may be mentioned, and these may be linear or branched, and may be cyclic alkyl groups.
Examples of the alkenyl group having 1 to 20 carbon atoms include allyl and 2-butenyl groups, which may be linear or branched, and are cyclic alkenyl groups. May be.
Examples of the alkynyl group having 1 to 20 carbon atoms include a 1-pentynyl group, which may be linear or branched, and may be a cyclic alkynyl group. Good.
[0074]
Specific examples of the compound represented by the above formula (I) include, for example, methyl glucoside, ethyl glucoside, propyl glucoside, isopropyl glucoside, butyl glucoside, isobutyl glucoside, n-hexyl glucoside, octyl glucoside, capryl glucoside, decyl glucoside, Examples include 2-ethylhexyl glucoside, 2-pentylnonyl glucoside, 2-hexyl decyl glucoside, lauryl glucoside, myristyl glucoside, stearyl glucoside, cyclohexyl glucoside, and 2-butynyl glucoside. These compounds are glucosides, which are a type of glycoside, in which the hemiacetal hydroxyl group of glucose is linked to other compounds in an ether form, and are obtained, for example, by a known method of reacting glucose with alcohols. be able to. Some of these alkyl glucosides are marketed under the trade name GLUCOPON by Henkel, Germany, and can be used in the present invention.
[0075]
Other examples of preferred glycosides include saponins, rutin trihydrate, hesperidin methyl chalcone, hesperidin, nalidine hydrate, phenol-β-D-glucopyranoside, salicin, 3 ′, 5,7-methoxy-7. -Rutinosides are mentioned.
[0076]
The pH of the aqueous solution containing the saccharide compound is preferably 8 to 11, and can be adjusted to the above pH range using potassium hydroxide, sulfuric acid, carbonic acid, sodium carbonate, phosphoric acid, sodium phosphate or the like.
[0077]
The concentration of the aqueous solution of polyvinylphosphonic acid is preferably 0.1 to 5% by mass, and more preferably 0.2 to 2.5% by mass. The immersion temperature is preferably 10 to 70 ° C, and more preferably 30 to 60 ° C. The immersion time is preferably 1 to 20 seconds.
Moreover, it is preferable that the density | concentration of the aqueous solution of the compound which has a sulfonic acid group is 0.02-0.2 mass%. The immersion temperature is preferably 60 to 100 ° C. The immersion time is preferably 1 to 300 seconds, and more preferably 10 to 100 seconds.
Further, the aqueous solution of the saccharide compound preferably has a concentration of 0.5 to 10% by mass. The immersion temperature is preferably 40 to 70 ° C. The immersion time is preferably 2 to 300 seconds, and more preferably 5 to 30 seconds.
[0078]
In the present invention, as the aqueous solution containing a hydrophilic compound, in addition to the organic compound aqueous solution as described above, an alkali metal silicate aqueous solution, potassium zirconium fluoride (K ₂ ZrF ₆ An aqueous solution of an inorganic compound such as an aqueous solution or an aqueous solution containing a phosphate / inorganic fluorine compound is also preferably used.
[0079]
The alkali metal silicate treatment is preferably an alkali metal silicate having a concentration of 0.01 to 30% by mass, more preferably 0.1 to 10% by mass, and a pH at 25 ° C. of preferably 10 to 13. It is carried out by immersing the support in an aqueous acid salt solution at 30 to 100 ° C., more preferably 50 to 90 ° C., preferably 0.5 to 40 seconds, more preferably 1 to 20 seconds.
[0080]
Examples of the alkali metal silicate used for the hydrophilic surface treatment include those listed as the alkali metal silicate used for the fixing treatment liquid containing at least one of the fluorine compound and the silicate compound described above. It is done.
The aqueous solution of alkali metal silicate may contain an appropriate amount of a hydroxide such as sodium hydroxide, potassium hydroxide, or lithium hydroxide in order to increase the pH. Of these, sodium hydroxide and potassium hydroxide are preferable.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVB) metal salt. Examples of the alkaline earth metal salt include alkaline earth metal salts exemplified in the fixing treatment liquid containing at least one of the above-described fluorine compound and silicate compound. Alkaline earth metal salts and Group 4 (Group IVB) metal salts are used alone or in combination of two or more.
[0081]
Zirconium potassium fluoride aqueous solution treatment is preferably carried out at an aqueous solution of potassium zirconium fluoride having a concentration of 0.1 to 10% by mass, more preferably 0.5 to 2% by mass, preferably at 30 to 80 ° C. It is preferably performed by dipping for 60 to 180 seconds.
[0082]
The phosphate / inorganic fluorine compound treatment is preferably an aqueous solution having a phosphate compound concentration of 5 to 20% by mass and an inorganic fluorine compound concentration of 0.01 to 1% by mass, preferably a pH of 3 to 5. The support is preferably immersed in at 20 to 100 ° C., more preferably at 40 to 80 ° C., preferably for 2 to 300 seconds, more preferably for 5 to 30 seconds.
[0083]
Examples of the phosphate used in the present invention include phosphates of metals such as alkali metals and alkaline earth metals.
Specifically, for example, zinc phosphate, aluminum phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, monoammonium phosphate, monopotassium phosphate, monosodium phosphate, dihydrogen phosphate Potassium, dipotassium hydrogen phosphate, calcium phosphate, sodium ammonium hydrogen phosphate, magnesium hydrogen phosphate, magnesium phosphate, ferrous phosphate, ferric phosphate, sodium dihydrogen phosphate, sodium phosphate, hydrogen phosphate Disodium, lead phosphate, diammonium phosphate, calcium dihydrogen phosphate, lithium phosphate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, ammonium phosphomolybdate, sodium phosphomolybdate; sodium phosphite , Tripolyphosphate Potassium, and sodium pyrophosphate. Among these, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate are preferable.
[0084]
Moreover, a metal fluoride is mentioned suitably as an inorganic fluorine compound used for hydrophilic surface treatment.
Specifically, what was enumerated as a fluorine compound used for the sealing treatment liquid containing at least any one of the fluorine compound mentioned above and a silicic acid compound is mentioned, for example.
The aqueous solution used for the phosphate / inorganic fluorine compound treatment may contain one or more phosphates and inorganic fluorine compounds, respectively.
After immersing the support in an aqueous solution containing these hydrophilic compounds, the support is washed with water or the like and dried.
[0085]
[Undercoat layer]
Before providing a recording layer (hereinafter also referred to as a heat-sensitive layer) writable by infrared laser exposure on the aluminum support (substrate) of the present invention obtained as described above, for example, An inorganic undercoat layer such as a water-soluble metal salt such as zinc acid or an organic undercoat layer may be provided.
[0086]
Examples of the organic compound used in the organic undercoat layer include carboxymethyl cellulose; dextrin; gum arabic; polymers and copolymers having a sulfonic acid group in the side chain; polyacrylic acid; amino such as 2-aminoethylphosphonic acid Phosphonic acids having a group; organic phosphonic acids such as phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid, and ethylenediphosphonic acid, which may have a substituent; Organic phosphoric acid such as phenylphosphonic acid, naphthylphosphoric acid, alkylphosphoric acid, glycerophosphoric acid, which may be substituted; phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid, glycerophosphinic acid, etc., which may have a substituent Organic phosphinic acids; amino acids such as glycine and β-alanine Amine hydrochloride having a hydroxyl group such as triethanolamine hydrochloride; and the yellow dye. These may be used alone or in combination of two or more.
[0087]
The organic undercoat layer can be provided by the following method. That is, a method in which a solution obtained by dissolving the above organic compound in water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is applied on an aluminum support and dried to form an organic subbing layer, water or The aluminum support is immersed in a solution in which the organic compound is dissolved in an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof to adsorb the organic compound, and then washed with water and dried. Thus, an organic undercoat layer can be provided.
[0088]
In the former method, the concentration of the solution in which the organic compound is dissolved is preferably 0.005 to 10% by mass. The coating method is not particularly limited, and any method such as bar coater coating, spin coating, spray coating, curtain coating and the like can be used. In the latter method, the concentration of the solution in which the organic compound is dissolved is preferably 0.01 to 20% by mass, more preferably 0.05 to 5% by mass, and the immersion temperature is The temperature is preferably 20 to 90 ° C, more preferably 25 to 50 ° C, and the immersion time is preferably 0.1 second to 20 minutes, more preferably 2 seconds to 1 minute. The solution used in these methods can be used in a pH range of 1 to 12 by adjusting the pH with a basic substance such as ammonia, triethylamine or potassium hydroxide, or an acidic substance such as hydrochloric acid or phosphoric acid.
[0089]
The coating amount of the organic undercoat layer after drying is 2 to 200 mg / m ² Is preferably 5 to 100 mg / m ² It is more preferable that When it is in the above range, the printing durability becomes better.
Further, an intermediate layer of a polymer compound having an acid group and an onium group described in JP-A-11-109637 can be used as an undercoat layer.
[0090]
[Recording layer]
The lithographic printing plate support of the present invention can be provided with a recording layer such as an image to form the lithographic printing plate precursor of the present invention.
In the present invention, the recording layer described below on the lithographic printing plate support has a coating amount after drying of 0.3 to 1.8 g / m. ² It is preferable to provide such that When the coating amount of the recording layer is adjusted to the above range, both excellent printing durability and high sensitivity can be achieved. The coating amount is 0.3 g / m ² If it is less than 1, the printing durability becomes insufficient, and 1.8 g / m. ² If it is over, the sensitivity tends to decrease.
[0091]
When the lithographic printing plate support of the present invention is combined with a heat-sensitive layer described below, the micropores of the anodic oxide film on the surface of the support are coated with a high proportion of inorganic compound particles. Intrusion into the pore can be suppressed, and the development speed is improved.
[0092]
A photosensitive composition is used for the information recording layer such as an image provided on the lithographic printing plate support of the present invention.
The photosensitive composition suitably used in the present invention is preferably a “thermosensitive composition” that contains a photothermal conversion substance and forms an image by heat generated in an exposed area, such as an alkali-soluble polymer compound and photothermal conversion. Thermal positive photosensitive composition containing a substance (hereinafter, this composition and an image recording layer using the same are referred to as “thermal positive type”), a thermal negative type containing a curable compound and a photothermal conversion substance It is desirable to use a photosensitive composition (hereinafter also referred to as “thermal negative type”). Furthermore, when combined with a “thermosensitive composition” (hereinafter also referred to as “non-treatment type”) that does not require a special development process, the development treatment with dampening water (on-machine development) on the printing press is extremely short. The effect of ending in time can be obtained. Hereinafter, these suitable photosensitive compositions will be described.
[0093]
<Thermal positive type>
<Photosensitive layer>
The thermal positive photosensitive composition contains a water-insoluble and alkali-soluble polymer compound (referred to as “alkali-soluble polymer compound” in the present invention) and a photothermal conversion substance. In the thermal positive type image recording layer, the photothermal conversion substance converts the energy of light such as infrared lasers into heat, which effectively eliminates the interaction that reduces the alkali solubility of alkali-soluble polymer compounds. To do.
[0094]
Examples of the alkali-soluble polymer compound include a resin containing an acidic group in the molecule and a mixture of two or more thereof. In particular, phenolic hydroxy groups, sulfonamide groups (-SO ₂ NH-R (wherein R represents a hydrocarbon group)), an active imino group (-SO ₂ NHCOR, -SO ₂ NHSO ₂ R, -CONHSO ₂ A resin having an acidic group such as R (wherein R has the same meaning as described above)) is preferable in terms of solubility in an alkali developer.
In particular, a resin having a phenolic hydroxy group is preferable in that it has excellent image-forming properties when exposed to light such as an infrared laser, and examples thereof include phenol-formaldehyde resins, m-cresol-formaldehyde resins, p-cresol-formaldehyde resins, m- / p-mixed cresol-formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) mixed-formaldehyde resin (phenol-cresol-formaldehyde co-condensation resin) and other novolak resins Are preferable.
Furthermore, the polymer compound described in JP-A No. 2001-305722 (particularly [0023] to [0042]), and the repetition represented by the general formula (1) described in JP-A No. 2001-215893 Preferred examples also include polymer compounds containing units, and polymer compounds described in JP-A No. 2002-311570 (particularly [0107]).
[0095]
Preferable examples of the photothermal conversion substance include pigments or dyes having a light absorption region in the infrared region having a wavelength of 700 to 1200 nm from the viewpoint of recording sensitivity. Examples of the dye include azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes (for example, , Nickel thiolate complex). Among these, cyanine dyes are preferable, and cyanine dyes represented by the general formula (I) described in JP 2001-305722 A are particularly preferable.
[0096]
The thermal positive type photosensitive composition may contain a dissolution inhibitor. As the dissolution inhibitor, for example, dissolution inhibitors described in JP-A-2001-305722, [0053] to [0055] are preferably exemplified.
In addition, in the thermal positive type photosensitive composition, as a additive, a sensitivity modifier, a printing agent for obtaining a visible image immediately after heating by exposure, a compound such as a dye as an image colorant, a coating property In addition, it is preferable to include a surfactant for improving the processing stability. For these, compounds described in JP-A-2001-305722, [0056] to [0060] are preferable.
The photosensitive composition described in detail in Japanese Patent Application Laid-Open No. 2001-305722 is also preferably used in other respects.
[0097]
Further, the thermal positive type image recording layer is not limited to a single layer but may have a two-layer structure.
As an image recording layer having a two-layer structure (multilayer image recording layer), a lower layer (hereinafter referred to as “A layer”) having excellent printing durability and solvent resistance is provided on the side close to the support, and a positive layer is provided thereon. A type provided with a layer having excellent image formability (hereinafter referred to as “B layer”) is preferable. This type has high sensitivity and can realize a wide development latitude. The B layer generally contains a photothermal conversion substance. Preferred examples of the photothermal conversion substance include the dyes described above.
As the resin used in the A layer, a polymer having a monomer having a sulfonamide group, an active imino group, a phenolic hydroxy group or the like as a copolymerization component is preferably used because it has excellent printing durability and solvent resistance. . As the resin used for the B layer, an alkaline aqueous solution-soluble resin having a phenolic hydroxy group is preferably exemplified.
In addition to the resin, the composition used for the A layer and the B layer can contain various additives as necessary. Specifically, various additives as described in JP-A-2002-3233769, [0062] to [0085] are preferably used. Further, the additives described in [0053] to [0060] of JP-A-2001-305722 described above are also preferably used.
About each component which comprises A layer and B layer, and its content, it is preferable to make it describe in Unexamined-Japanese-Patent No. 11-218914.
[0098]
<Intermediate layer>
An intermediate layer is preferably provided between the thermal positive type image recording layer and the support. As the component contained in the intermediate layer, various organic compounds described in [0068] of JP-A No. 2001-305722 are preferably exemplified.
[0099]
<Others>
As a method for producing a thermal positive type image recording layer and a plate making method, methods described in detail in JP-A No. 2001-305722 can be used.
[0100]
<Thermal negative type>
The thermal negative photosensitive composition contains a curable compound and a photothermal conversion substance. The thermal negative type image recording layer is a negative photosensitive layer in which a portion irradiated with light such as an infrared laser is cured to form an image portion.
<Polymerized layer>
As one of the thermal negative type image recording layers, a polymerization type image recording layer (polymerization layer) is preferably exemplified. The polymerization layer contains a photothermal conversion substance, a radical generator, a radical polymerizable compound that is a curable compound, and a binder polymer. In the polymerization layer, infrared light absorbed by the light-to-heat conversion substance is converted into heat, the radical generator is decomposed by this heat to generate radicals, and the radical polymerizable compound is polymerized in a chain by the generated radicals and cured. .
[0101]
As a photothermal conversion substance, the photothermal conversion substance used for the thermal positive type mentioned above is mentioned, for example. Specific examples of particularly preferred cyanine dyes include those described in JP-A-2001-133969, [0017] to [0019].
Preferred examples of the radical generator include onium salts. In particular, onium salts described in JP-A-2001-133969, [0030] to [0033] are preferable.
Examples of the radical polymerizable compound include compounds having at least one terminal ethylenically unsaturated bond, preferably two or more.
As the binder polymer, a linear organic polymer is preferably exemplified. Preferred examples include linear organic polymers that are soluble or swellable in water or weak alkaline water. Among them, a (meth) acrylic resin having an unsaturated group such as an allyl group or an acryloyl group or a benzyl group and a carboxy group in the side chain is preferable in that it has an excellent balance of film strength, sensitivity, and developability. .
As the radical polymerizable compound and the binder polymer, those described in detail in [0036] to [0060] of JP-A No. 2001-133969 can be used.
[0102]
The additive described in [0061] to [0068] of JP-A No. 2001-133969 is contained in the thermal negative photosensitive composition (for example, a surfactant for improving coatability). Is preferred.
[0103]
As a method for producing the polymerization layer and a plate making method, methods described in detail in JP-A No. 2001-133969 can be used.
[0104]
<Acid cross-linked layer>
Further, as one of the thermal negative type image recording layers, an acid cross-linked image recording layer (acid cross-linked layer) is also preferably exemplified. The acid cross-linking layer comprises a photothermal conversion substance, a thermal acid generator, a compound that cross-links with an acid that is a curable compound (cross-linking agent), and an alkali-soluble polymer compound that can react with the cross-linking agent in the presence of an acid. contains. In the acid cross-linking layer, infrared light absorbed by the photothermal conversion substance is converted into heat, the heat acid generator is decomposed by this heat to generate an acid, and the generated acid reacts with the cross-linking agent and the alkali-soluble polymer compound. And harden.
[0105]
Examples of the photothermal conversion substance include the same substances as those used for the polymerization layer.
Examples of the thermal acid generator include thermal decomposition compounds such as photoinitiators for photopolymerization, photochromic agents for dyes, and acid generators used in microresists.
Examples of the crosslinking agent include an aromatic compound substituted with a hydroxymethyl group or an alkoxymethyl group; a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group; and an epoxy compound.
Examples of the alkali-soluble polymer compound include a novolak resin and a polymer having a hydroxyaryl group in the side chain.
[0106]
<Non-treatment type>
Examples of the untreated type heat-sensitive layer include a thermoplastic fine particle polymer type, a microcapsule type, a sulfonic acid-generating polymer-containing type, a cationic polymerizable monomer or a radical polymerizable monomer-containing type. These are all heat-sensitive types containing a photothermal conversion substance. The photothermal conversion substance is preferably the same dye as that used in the above-described thermal positive type.
[0107]
The thermoplastic fine particle polymer type photosensitive composition is obtained by dispersing a hydrophobic and heat-meltable fine particle polymer in a hydrophilic polymer matrix. In the image recording layer of the thermoplastic fine particle polymer type, the hydrophobic fine particle polymer is melted by heat generated by exposure and is fused to form a hydrophobic region, that is, an image portion.
As the fine particle polymer, those in which fine particles melt and coalesce with heat are preferable, and those having a hydrophilic surface and capable of being dispersed in a hydrophilic component such as dampening water are more preferable. Specifically, ResearchDisclosureNo. 33303 (January 1992), JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, and JP-A-9-171250, and European Patent Application Publication No. 931,647. Preferred examples thereof include thermoplastic fine particle polymers. Of these, polystyrene and polymethyl methacrylate are preferred. Examples of the fine particle polymer having a hydrophilic surface include those in which the polymer itself is hydrophilic; those in which a hydrophilic compound such as polyvinyl alcohol and polyethylene glycol is adsorbed on the surface of the fine particle polymer to make the surface hydrophilic.
The fine particle polymer preferably has a reactive functional group.
[0108]
As a microcapsule type photosensitive composition, a compound having a heat-reactive functional group as described in JP-A No. 2000-118160 or JP-A No. 2001-277740 is included. A microcapsule type is preferable.
[0109]
The microcapsule used in the present invention includes the compound having the thermoreactive functional group. As the compound having a thermally reactive functional group, at least one selected from a polymerizable unsaturated group, a hydroxy group, a carboxy group, a carboxylate group, an acid anhydride, an amino group, an epoxy group, an isocyanate group, and a block form thereof. The compound which has the functional group of can be mentioned.
[0110]
As the compound having a polymerizable unsaturated group, a compound having at least one, preferably two or more ethylenically unsaturated bonds, for example, acryloyl group, methacryloyl group, vinyl group, allyl group, etc. is preferable. Groups are widely known in the industrial field, and these can be used without particular limitation in the present invention. These chemical forms include monomers, prepolymers, i.e. dimers, trimers and oligomers or mixtures thereof or copolymers thereof.
[0111]
Specific examples of the compound having a polymerizable unsaturated group include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof. These include esters of unsaturated carboxylic acids and aliphatic polyhydric alcohols and amides of unsaturated carboxylic acids and aliphatic polyvalent amines. Further, an addition reaction product of an unsaturated carboxylic acid ester or unsaturated carboxylic acid amide having a nucleophilic substituent such as a hydroxy group, an amino group, a mercapto group and the like with a monofunctional or polyfunctional isocyanate or epoxide, and a monofunctional Or a dehydration condensation reaction product with a polyfunctional carboxylic acid is also preferred. In addition, addition reaction product of unsaturated carboxylic acid ester or amide having an electrophilic substituent such as isocyanate group or epoxy group with monofunctional or polyfunctional alcohol, amine and thiol, halogen group, tosyloxy group, etc. Preferred examples also include a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent with a monofunctional or polyfunctional alcohol, amine and thiol. Another preferred example is a compound in which the unsaturated carboxylic acid is replaced with unsaturated phosphonic acid or chloromethylstyrene.
[0112]
Specific examples of the monomer of a compound having a polymerizable unsaturated group, which is an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol, include the ethylenically unsaturated bond-containing compound used in the photopolymer type photosensitive layer. Each acrylic acid ester, each methacrylic acid ester, each itaconic acid ester, each crotonic acid ester, each isocrotonic acid ester, and each maleic acid ester exemplified in the above.
[0113]
Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334 and JP-A-57-196231, JP-A-59- 5240, those having aromatic skeletons described in JP-A-59-5241 and JP-A-2-226149, and amino groups described in JP-A-1-165613 A thing etc. are used suitably.
[0114]
Specific examples of amide monomers of unsaturated carboxylic acid and aliphatic polyvalent amine include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis- Examples include methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, and xylylene bismethacrylamide. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.
[0115]
In addition, as a compound having a polymerizable unsaturated group, a urethane-based addition polymerizable compound produced by an addition reaction between an isocyanate group and a hydroxy group is also preferably used. Specific examples thereof include, for example, JP-B-48. -41708 In one molecule, an unsaturated monomer having a hydroxy group represented by the following formula (I) is added to a polyisocyanate compound having two or more isocyanate groups in one molecule. And urethane compounds containing one or more polymerizable unsaturated groups.
[0116]
CH ₂ = C (R ¹ ) COOCH ₂ CH (R ² ) OH ... (I)
(In the above formula (I), R ¹ And R ² Are respectively H or CH ₃ Indicates. )
[0117]
Further, urethane acrylates described in JP-A-51-37193, JP-B-2-32293, and JP-B-2-16765, JP-B-58-49860, JP-B-56-17654, and the like. Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 can also be mentioned as preferable examples.
[0118]
Further, a radical polymerizable compound having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909 and JP-A-1-105238 is preferably used. Can be cited as a thing.
[0119]
Examples of other suitable ones include polyester acrylates, epoxy resins and (meth) acrylic as described in JP-A-48-64183, JP-B-49-43191 and JP-A-52-30490. Mention may be made of polyfunctional (meth) acrylates such as epoxy acrylates reacted with an acid. Further, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337 and JP-A-1-40336, and vinylphosphones described in JP-A-2-25493. Acid compounds and the like can also be mentioned as suitable ones. In some cases, compounds containing a perfluoroalkyl group described in JP-A-61-22048 are also preferably used. Furthermore, Journal of Japan Adhesion Association, Vol. 20, No. 7, p. Those introduced as photocurable monomers and oligomers in 300-308 (1984) can also be suitably used.
[0120]
Examples of the compound having an epoxy group include glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene diglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, bisphenols or polyphenols or hydrogenated polyglycidyl. Preferred examples include ether.
[0121]
As compounds having an isocyanate group, tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, cyclohexanephenylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, cyclohexyl diisocyanate; blocking them with alcohol or amine Preferred examples of the compound are as follows.
[0122]
Preferred examples of the compound having an amino group include ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, propylenediamine, and polyethyleneimine.
[0123]
Preferred examples of the compound having a hydroxy group include compounds having a terminal methylol group, polyhydric alcohols such as pentaerythritol, bisphenols and polyphenols, and the like. Preferred examples of the compound having a carboxy group include aromatic polyvalent carboxylic acids such as pyromellitic acid, trimellitic acid and phthalic acid, and aliphatic polyvalent carboxylic acids such as adipic acid. Preferable examples of the compound having an acid anhydride include pyromellitic acid anhydride and benzophenone tetracarboxylic acid anhydride.
[0124]
Preferred examples of the copolymer of the compound having an ethylenically unsaturated bond include a copolymer of allyl methacrylate. Specific examples include allyl methacrylate / methacrylic acid copolymer, allyl methacrylate / ethyl methacrylate copolymer, allyl methacrylate / butyl methacrylate copolymer, and the like.
[0125]
As a method for producing a microcapsule encapsulating a compound having a heat-reactive functional group, a known method can be applied. For example, as a method for producing microcapsules, a method using coacervation described in US Pat. Nos. 2,800,457 and 2,800,458, British Patent 990,443 is disclosed. No. 3,287,154, Japanese Patent Publication Nos. 38-19574, 42-446, and 42-711, a method by an interfacial polymerization method, US Pat. Method by polymer precipitation described in US Pat. Nos. 3,418,250 and 3,660,304, isocyanate polyol wall material described in US Pat. No. 3,796,669 A method using an isocyanate wall material described in US Pat. No. 3,914,511, US Pat. No. 4,001,140, Methods using urea-formaldehyde or urea formaldehyde-resorcinol wall-forming materials described in US Pat. Nos. 4,087,376 and 4,089,802, US Pat. No. 4,025,445 A method using a wall material such as melamine-formaldehyde resin and hydroxycellulose described in the specification, in situ method by monomer polymerization described in Japanese Patent Publication Nos. 36-9163 and 51-9079, a British patent No. 930,422 and U.S. Pat. No. 3,111,407, the spray drying method described in British Patent Nos. 952,807 and 967,074. An electrolytic dispersion cooling method or the like can be used.
[0126]
The microcapsule wall used for the microcapsule encapsulating the compound having a heat-reactive functional group preferably has a three-dimensional crosslinking and has a property of swelling with a solvent. From this viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, or a mixture thereof, and among them, polyurea and / or polyurethane is more preferable. You may introduce | transduce the compound which has the said thermoreactive functional group into the said microcapsule wall.
[0127]
The average particle size of the microcapsules encapsulating the compound having a heat-reactive functional group is preferably 0.01 to 20 μm, more preferably 0.05 to 2.0 μm, and 0.10 to 1. More preferably, it is 0 μm. If the average particle size is too large, the resolution will deteriorate, and if it is too small, the stability over time will deteriorate.
[0128]
The microcapsules encapsulating such a compound having a heat-reactive functional group may be ones in which the microcapsules are combined by heat or may not be combined. In short, among the microcapsule inclusions, the one that oozes out of the capsule surface or outside the microcapsule at the time of application, or the one that penetrates into the microcapsule wall may cause a chemical reaction by heat. Moreover, you may react with the added hydrophilic resin or the added low molecular weight compound. In addition, two or more kinds of microcapsules may be reacted with each other by providing functional groups that thermally react with each other with different functional groups. Therefore, it is preferable for image formation that the microcapsules are fused and united with heat, but it is not essential.
[0129]
The content of the microcapsules encapsulating the compound having a heat-reactive functional group in the heat-sensitive layer is preferably 10 to 60% by mass, and preferably 15 to 40% by mass with respect to the total solid content of the heat-sensitive layer. Is more preferable. Within the above range, good on-press developability as well as good sensitivity and printing durability can be obtained.
[0130]
When a microcapsule that encapsulates a compound having a heat-reactive functional group is contained in the heat-sensitive layer, a solvent that can dissolve the inclusion and swell the wall material is added to the microcapsule dispersion medium. be able to. By such a solvent, diffusion of the encapsulated compound having a heat-reactive functional group to the outside of the microcapsule is promoted. The selection of such a solvent depends on the microcapsule dispersion medium, the material of the microcapsule wall, the wall thickness, and the inclusions, but can be easily selected from many commercially available solvents. For example, in the case of a water-dispersible microcapsule comprising a crosslinked polyurea or polyurethane wall, alcohols, ethers, acetals, esters, ketones, polyhydric alcohols, amides, amines, fatty acids and the like are preferable.
[0131]
Specifically, methanol, ethanol, tert-butanol, n-propanol, tetrahydrofuran, methyl lactate, ethyl lactate, methyl ethyl ketone, propylene glycol monomethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, γ-butyllactone, N, N -Dimethylformamide, N, N-dimethylacetamide and the like can be mentioned, but the present invention is not limited to these. Two or more of these solvents may be used.
[0132]
A solvent that does not dissolve in the microcapsule dispersion but dissolves when the solvent is mixed can also be used. The amount added depends on the combination of materials. When the amount is less than the appropriate value, image formation is insufficient, and when the amount is large, the stability of the dispersion deteriorates. Usually, it is effective that it is 5-95 mass% of a coating liquid, it is preferable that it is 10-90 mass%, and it is more preferable that it is 15-85 mass%.
[0133]
If the untreated type heat-sensitive layer contains microcapsules containing a fine particle polymer having a heat-reactive functional group and / or a compound having a heat-reactive functional group, these reactions are initiated as necessary. A compound to be promoted or promoted may be added. Examples of the compound that initiates or accelerates the reaction include compounds that generate radicals or cations by heat. Examples thereof include lophine dimer, trihalomethyl compound, peroxide, azo compound, onium salt (diazonium salt, diphenyliodonium salt, etc.), acylphosphine, imide sulfonate and the like. The content of these compounds is preferably 1 to 20% by mass and more preferably 3 to 10% by mass with respect to the total solid content of the heat-sensitive layer. If it is within the above range, good onset reaction reaction effect or reaction promoting effect can be obtained without impairing on-press developability.
[0134]
Examples of the sulfonic acid generating polymer used in the sulfonic acid generating polymer-containing photosensitive composition include sulfonic acid ester groups, disulfone groups, and sec- or tert-sulfonamides described in JP-A No. 10-282672. Examples thereof include polymers having a group in the side chain.
[0135]
As the cationically polymerizable monomer- or radically polymerizable monomer-containing type image recording layer, a heat-sensitive layer as described in WO02 / 21215 (US2002 / 0068240A1) can be used.
[0136]
By incorporating a hydrophilic resin into the unprocessed photosensitive composition, not only on-press developability is improved, but also the film strength of the photosensitive layer itself is improved. Examples of the hydrophilic resin include those having a hydrophilic group such as hydroxy group, carboxy group, hydroxyethyl group, hydroxypropyl group, amino group, aminoethyl group, aminopropyl group, carboxymethyl group, and hydrophilic sol-gel conversion system. A binder resin is preferred.
[0137]
The unprocessed type image recording layer does not require a special development step and can be developed on a printing press. As a method for producing an unprocessed image recording layer and a plate-making printing method, methods described in detail in JP-A No. 2002-178655 can be used.
[0138]
It is necessary to add a photothermal conversion substance to the untreated type heat-sensitive layer. The photothermal conversion substance may be any substance that absorbs light having a wavelength of 700 nm or more, and various pigments, dyes, and metal fine particles can be used.
[0139]
Examples of the pigment include commercially available pigments, Color Index (CI) Handbook, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986). And pigments described in “Printing Ink Technology” published by CMC (published in 1984) can be used. Specifically, the pigment illustrated above is mentioned as a photothermal conversion substance contained in a thermal positive type thermosensitive layer, for example.
[0140]
Similar to the pigment contained in the thermal positive type heat-sensitive layer, these pigments may be used without surface treatment or may be used after surface treatment.
[0141]
Among these, a pigment that absorbs infrared rays is preferable in that it is suitable for use with a laser that emits infrared rays. As a pigment that absorbs infrared rays, carbon black is preferable, and among them, the surface is coated with a hydrophilic resin or silica sol so that it can be easily dispersed with a water-soluble or hydrophilic resin and the hydrophilicity is not impaired. Carbon black is particularly preferred. The particle diameter of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm.
[0142]
As the dye, commercially available dyes and known dyes described in literature (for example, “Dye Handbook” edited by the Society of Synthetic Organic Chemistry, published in 1970) can be used. Specific examples include azo dyes, metal complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, and cyanine dyes. Among these, dyes that absorb infrared rays are particularly preferable because they are suitable for use in lasers that emit infrared rays.
[0143]
Examples of dyes that absorb infrared rays include cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, and the like. Methine dyes described in JP-A Nos. 173696, 58-181690, 58-194595, JP-A-58-112793, JP-A-58-224793, JP-A-59 Naphthoquinone dyes described in JP-A-58187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc., and JP-A-58-112792 Squalyl dyes, cyanine dyes described in British Patent 434,875, and dyes described in US Pat. No. 4,756,993, Cyanine dyes described in Patent 4,973,572, can be cited dyes described in JP-A-10-268512.
[0144]
Further, near infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used as dyes, and are described in US Pat. No. 3,881,924. Substituted arylbenzo (thio) pyrylium salts, trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169); 181051, No. 58-220143, No. 59-41363, No. 59-84248, No. 59-84249, No. 59-146063, No. 59-146061, Cyanine dyes described in JP-A-59-216146, pentamethine thiopyrilyu described in US Pat. No. 4,283,475 Salts, pyrylium compounds described in KOKOKU 5-13514 JP and the 5-19702 JP; EpolightIII-178, EpolightIII-130, EpolightIII-125 (all manufactured by Eporin Corporation) also preferably used. Among them, particularly preferred dyes are water-soluble dyes, and specific examples are listed below by structural formulas.
[0145]
[Chemical 2]

[0146]
[Chemical 3]

[0147]
[Formula 4]

[0148]
[Chemical formula 5]

[0149]
[Chemical 6]

[0150]
[Chemical 7]

[0151]
[Chemical 8]

[0152]
[Chemical 9]

[0153]
The metal fine particle is not particularly limited as long as it is a metal fine particle that is photothermally convertible and thermally fused by light irradiation, but it is a fine particle of a simple substance or alloy of a metal belonging to Group 8 to 11 (Group VIII and Group IB). It is preferable to be fine particles of a simple substance or alloy of a metal selected from Ag, Au, Cu, Pt and Pd. The metal fine particles are used by adding an aqueous solution of the above metal salt or complex salt to an aqueous solution containing a dispersion stabilizer, further adding a reducing agent to form a metal colloid, and then removing unnecessary salts.
[0154]
Examples of the dispersion stabilizer include carboxylic acids such as citric acid and oxalic acid and salts thereof; polymers such as PVP, PVA, gelatin, and acrylic resin. Examples of the reducing agent include base metal salts (for example, FeSO4, SnSO4), borohydride compounds, formalin, dextrin, glucose, Rossell salt, tartaric acid, sodium thiosulfate, and hypophosphite. The average particle size of the metal colloid is preferably 1 to 500 nm, more preferably 1 to 100 nm, and still more preferably 1 to 50 nm. The degree of dispersion may be polydispersion, but monodispersion with a coefficient of variation of 30% or less is preferred. As a method for removing unnecessary salts, for example, an ultrafiltration method; a mixed solution of methanol and water or a mixed solution of ethanol and water is added to a colloidal dispersion, and the mixture is allowed to settle naturally or by centrifugal sedimentation. And a method of removing the supernatant.
[0155]
In the case of a pigment or dye, the content of the photothermal conversion substance is preferably 30% by mass or less, more preferably 5 to 25% by mass, and more preferably 7 to 20% by mass with respect to the total solid content of the heat-sensitive layer. % Is more preferable. In the case of metal fine particles, it is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 20% by mass or more, based on the total solid content of the heat-sensitive layer. If the content of the metal fine particles is less than 5% by mass, the sensitivity may be lowered.
[0156]
In addition to the above-described components, the untreated type heat-sensitive layer can contain various compounds as required. For example, a polyfunctional monomer can be included in the matrix of the heat-sensitive layer in order to further improve the printing durability. As such a polyfunctional monomer, those exemplified as the monomer encapsulated in the microcapsule can be used. A particularly preferred monomer is trimethylolpropane triacrylate.
[0157]
In addition, a dye having a large absorption in the visible light region can be used as an image colorant in the non-process type heat-sensitive layer in order to make it easy to distinguish between an image area and a non-image area after image formation. . Specifically, oil yellow # 101, oil yellow # 103, oil pink # 312, oil green BG, oil blue BOS, oil blue # 603, oil black BY, oil black BS, oil black T-505 (or more, Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI52015), Japanese Patent Application Laid-Open No. 62-293247 Can be mentioned. In addition, pigments such as phthalocyanine pigments, azo pigments, and titanium oxide can also be suitably used. These contents are preferably 0.01 to 10% by mass with respect to the total solid content of the heat-sensitive layer.
[0158]
Moreover, when a non-process type heat sensitive layer contains the compound which has an ethylenically unsaturated bond, in order to prevent the unnecessary thermal polymerization, it is preferable to add a small amount of thermal polymerization inhibitors. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol ), 2,2'-methylenebis (4-methyl-6-t-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt and the like. The content of the thermal polymerization inhibitor is preferably about 0.01 to about 5% by mass with respect to the total solid content of the heat-sensitive layer.
[0159]
In addition, to the untreated type heat-sensitive layer, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition by oxygen, and in the process of drying after coating. It may be unevenly distributed on the surface of the heat sensitive layer. The content of the higher fatty acid derivative is preferably about 0.1 to about 10% by mass with respect to the total solid content of the heat-sensitive layer.
[0160]
Furthermore, the non-treatment type heat-sensitive layer can contain a plasticizer in order to impart flexibility and the like of the coating film, if necessary. Examples of the plasticizer include polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, and tetrahydrofurfuryl oleate. It is done.
[0161]
Further, the non-treatment type heat-sensitive layer can contain inorganic fine particles. Examples of the inorganic fine particles include silica, alumina, magnesium oxide, magnesium carbonate, calcium alginate and the like. Even if these are not photothermal convertible, they have effects such as strengthening of the film and strengthening of interfacial adhesion by surface roughening of the heat sensitive layer. The content of the inorganic fine particles is preferably 1.0 to 70% by mass and more preferably 5.0 to 50% by mass with respect to the total solid content of the heat-sensitive layer. The effect expected to be 1% or less is small, and if it is 70% by mass or more, the originally required content of the photothermal conversion substance may be restricted.
[0162]
Further, the non-treatment type heat-sensitive layer can contain hydrophilic sol-like particles.
Suitable examples of the hydrophilic sol-like particles include silica sol, alumina sol, magnesium oxide sol, magnesium carbonate sol, and calcium alginate sol. Among these, silica sol, alumina sol, calcium alginate sol, or a mixture thereof is preferable. Even if these are not photothermal convertible, there are effects such as improvement of hydrophilicity and strengthening of the sol-gel film.
[0163]
Silica sol has many hydroxy groups on its surface, and the inside is composed of siloxane bonds (—Si—O—Si). The silica sol is obtained by dispersing ultrafine silica particles having a particle diameter of 1 to 100 nm in water or a polar solvent, and is also referred to as colloidal silica. Details of the silica sol are described in “Applied Technology of High-Purity Silica” Vol. 3, supervised by Toshiro Kaga and Hayashi Hayashi, CMC Corporation (1991). Alumina sol is an alumina hydrate (boehmite type) having a colloidal size of 5 to 200 nm, such as anions in water (for example, halogen ions such as fluoride ions and chloride ions, acetate ions, etc.). Alumina is dispersed using a carboxylate anion or the like as a stabilizer. Any of these hydrophilic sol-like particles can be easily obtained as a commercial product.
[0164]
The average particle size of the hydrophilic sol-like particles is preferably 10 to 50 nm, and more preferably 10 to 40 nm. When the particle size of the hydrophilic sol-like particles is within the above range, the hydrophobized precursors such as metal fine particles contained as a photothermal conversion substance in the hydrophilic resin and the above-described hydrophobic heat-meltable resin fine particles (It is hydrophobic in a state where it is not exposed to light and it becomes hydrophobic upon exposure) and can be stably dispersed to sufficiently maintain the film strength of the heat-sensitive layer. When printing as a lithographic printing plate, there is obtained an effect that the ink does not cause smearing of the ink on the non-image area and becomes extremely hydrophilic.
[0165]
The proportion of the photothermal conversion substance (preferably carbon black, metal fine particles) and the hydrophilic sol-like particles is preferably 100/0 to 30/70, and preferably 100/0 to 40/60. More preferably. Further, the total content of the photothermal conversion substance, the hydrophobized precursor and the hydrophilic sol-like particles is preferably 2 to 95% by mass, and preferably 5 to 85% by mass, based on the total solid content of the heat-sensitive layer. It is more preferable that
[0166]
<Back coat>
In this way, the image recording layer in the case of being overlaid on the back surface of the lithographic printing plate precursor of the present invention obtained by providing various image recording layers on the lithographic printing plate support of the present invention, if necessary. In order to prevent scratching, a coating layer made of an organic polymer compound can be provided.
[0167]
<Method for forming recording layer>
Each layer such as an image recording layer can usually be produced by applying a coating solution obtained by dissolving the above components in a solvent onto a lithographic printing plate support.
Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to these. These solvents are used alone or in combination.
The concentration of the above components (total solid content) in the solvent is preferably 1 to 50% by mass.
[0168]
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.
[0169]
[Plate making method (lithographic printing plate production method)]
The lithographic printing plate precursor using the lithographic printing plate support of the present invention is converted into a lithographic printing plate by various treatment methods according to the image recording layer.
A laser beam is mainly used as an actinic ray light source used for image exposure. Examples include a helium-neon laser (He-Ne laser), an argon laser, a krypton laser, a helium-cadmium laser, a KrF excimer laser, a semiconductor laser, a YAG laser, and a YAG-SHG laser.
[0170]
When the image recording layer is a thermal positive type or a thermal negative type after the above exposure, it is preferable to obtain a lithographic printing plate after the exposure by developing with a developer. The developer is preferably an alkaline developer, and more preferably an alkaline aqueous solution substantially free of an organic solvent.
A developer containing substantially no alkali metal silicate and containing a saccharide (a developer containing substantially no alkali metal silicate) is also preferred. As a method of developing using a developer substantially not containing an alkali metal silicate, a method described in detail in JP-A No. 11-109637 can be used.
A developer containing an alkali metal silicate can also be used.
[0171]
When using the processing method of a lithographic printing plate precursor developed using a developer containing substantially no alkali metal silicate, there is a problem when developing using a developer containing an alkali metal silicate, SiO ₂ In the neutralization treatment when processing the waste liquid of the developer, ₂ Generation | occurrence | production of problems, such as the gel resulting from this, can be prevented.
[0172]
【Example】
(Example 1)
<Aluminum plate>
Si: 0.06 mass%, Fe: 0.28 mass%, Cu: 0.025 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: 0.03% by mass, Pb: 0.001% by mass, the balance being Al and an inevitable impurity aluminum alloy A, and Cu: 0.001% by mass, the other components being the same as alloy A A molten metal was prepared using, and after the molten metal treatment and filtration were performed, an ingot having a thickness of 500 mm and a width of 1200 mm was formed by a DC casting method. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, it was kept soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Further, after heat treatment was performed at 500 ° C. using a continuous annealing machine, the thickness was finished to 0.24 mm by cold rolling. This aluminum material was in the range of JIS 1050 material. After making this aluminum plate width 1030mm, it used for the surface treatment shown below.
[0173]
<Surface treatment>
The surface treatment at each level in the examples was carried out by continuously performing the following various treatments (a) to (n) in combination in the manufacturing process column shown in Table 1 as indicated by alphabetical display. In addition, after each process and water washing, the liquid was drained with the nip roller.
(A) Mechanical roughening treatment
Using an apparatus as shown in FIG. 1, a roller-type nylon brush rotating while supplying a suspension of abrasive (pamistone) having a specific gravity of 1.12 and water as a polishing slurry to the surface of the aluminum plate. Mechanical roughening treatment was performed. The average particle size of the abrasive was 40 μm, and the maximum particle size was 80 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 45 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 250 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.
[0174]
(B) Alkali etching treatment
The aluminum plate obtained above was subjected to an etching process by spraying using an aqueous solution having a caustic soda concentration of 26 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 60 ° C. ² Dissolved. Then, water washing by spraying was performed.
[0175]
(C) Desmut treatment
A desmut treatment was performed by spraying for 20 seconds with a 1% by mass aqueous solution of nitric acid having a nitric acid concentration of 30 ° C. (containing 0.5% by mass of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut treatment was a waste liquid from a process of performing an electrochemical surface roughening treatment using alternating current in a nitric acid aqueous solution.
[0176]
(D) 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 10.4 g / L aqueous solution (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions) at a liquid temperature of 50 ° C. An electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode, using a trapezoidal rectangular wave alternating current with a time TP of 0.8 msec until the current value reached a peak and a duty ratio of 1: 1. Ferrite was used for the auxiliary anode.
The current density is 30 A / dm at the peak current value. ² The amount of electricity is 195 C / dm as the total amount of electricity when the aluminum plate is the anode. ² Met. 5% of the current flowing from the power source was shunted to the auxiliary anode.
Then, water washing by spraying was performed.
[0177]
(E) Alkali etching treatment
The aluminum plate was etched by spraying at 32 ° 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 0.5 g / m. ² Dissolve 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.
[0178]
(F) Desmut treatment
The desmutting treatment was performed by spraying for 20 seconds with a 15% by weight aqueous solution of sulfuric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water by spraying. As the sulfuric acid aqueous solution used for the desmut treatment, the waste liquid of the step of performing the electrochemical surface roughening treatment using alternating current in the sulfuric acid aqueous solution was used.
[0179]
(G) 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 hydrochloric acid 5 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. An electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode, using a trapezoidal rectangular wave alternating current with a time TP of 0.8 msec until the current value reaches a peak from zero and a duty ratio of 1: 1. Ferrite was used for the auxiliary anode. The electrolytic cell used was the one shown in 2.
The current density is 25 A / dm at the peak current value. ² The amount of electricity is 60 C / dm as the total amount of electricity when the aluminum plate is the anode. ² Met.
Then, water washing by spraying was performed.
[0180]
(H) Alkali etching treatment
The aluminum plate was etched at 32 ° 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 0.2 g / m 2. ² Dissolve 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.
[0181]
(I) Desmut treatment
A desmutting treatment was performed by spraying for 20 seconds with a 25% by weight aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), and then washing with water by spraying.
[0182]
(J) Anodizing treatment
Anodization was performed using the anodizing apparatus having the structure shown in FIG. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 170 g / L (containing 0.5 mass% of aluminum ions) and a temperature of 38 ° C. Then, water washing by spraying was performed. The final oxide film amount is 2.7 g / m ² Met.
The pore diameter was measured by the method described above.
(K) Pore wide processing
Pore widening was performed by immersing the anodized aluminum plate in a sodium hydroxide aqueous solution of pH 13 at a temperature of 30 ° C. for 20 seconds to 40 seconds, and having different pore diameters (average pore diameters) shown in Table 1 A film was produced. Then, it washed with water and dried.
[0183]
(L) Formation of inorganic compound particle layer
An aqueous suspension containing the following inorganic compound particles was prepared on an aluminum plate after pore-wide treatment, and the coating amount after drying using a bar coater was 0.05 g / m. ² And dried at 100 ° C. for 2 minutes using an oven to form an inorganic compound particle layer shown in Table 1. The following short diameter and long diameter are average values. In the measurement method, a suspension of inorganic compound particles (solid content concentration: 0.2%) is dropped on a preparation, dried in a standing state, and then carbon is deposited and fixed on the surface. The surface of the sample thus prepared was observed with a scanning electron microscope (S-900, manufactured by Hitachi, Ltd.) at an acceleration voltage of 12 kV and a magnification of 120,000 times. The shortest diameter was measured, and the average value of each was calculated as the major axis and minor axis.
1) A water suspension containing 0.5% by mass of feather-shaped colloidal alumina particles (manufactured by Nissan Chemical Industries, AS200) having a minor axis of 10 nm and a major axis of 100 nm (aspect ratio = 10),
2) A water suspension containing 0.5% by mass of scaly titania particles (manufactured by Ishihara Sangyo) having a minor axis of 40 nm and a major axis of 200 nm (aspect ratio = 5),
3) A water suspension containing 0.5% by mass of granular alumina sol particles (manufactured by Nissan Chemical Industries, AS520) having a minor axis = major axis = 10 nm (aspect ratio = 1),
4) An aqueous suspension containing 0.5% by mass of granular alumina sol particles (Cai Kasei, Nanotek alumina) having a minor axis = major axis = 30 nm (aspect ratio = 1).
[0184]
(M) Fixing treatment
Examples 1 to 11 in which the following fixing treatment is performed on the aluminum plate after the inorganic compound particle layer is formed, followed by washing with water by spraying, drying, and providing an inorganic compound layer on the anodized film, comparative examples 1 to 9 lithographic printing plate supports were obtained.
1) 10 mass% aqueous solution of No. 3 sodium silicate: Examples 1, 3, 5, 6, Comparative Examples 2, 4, 6
2) Phosphoric acid / aluminum chloride aqueous solution (pH 4.3): Examples 2, 8, 9, 11, Comparative Examples 3, 7, 8
3) NaF (4.5 g) / Na ₂ HPO ₄ (585 g) / water (3910 g) in water (pH 4.3): Examples 4, 7, 10, Comparative Examples 1, 5, 9
The fixing process was performed by immersing in each of these solutions. The treatment liquid temperature was 70 ° C. and the immersion treatment time was 10 seconds. Thereafter, washing with water was performed by spraying and drying was performed, and an inorganic compound layer was provided on the anodized film.
[0185]
(N) Hydrophilization treatment
It was immersed in a 1% by weight aqueous solution of No. 3 sodium silicate at 30 ° C. for 10 seconds, then washed with water by spray and dried to effect surface hydrophilization (alkali metal silicate treatment).
[0186]
(O) Formation of heat-sensitive layer-1
As shown below, a heat-sensitive layer coating solution was applied to the lithographic printing plate support obtained above and dried to obtain a lithographic printing plate precursor.
A heat-sensitive layer coating solution having the following composition was prepared, and the coating amount after drying (heat-sensitive layer coating amount) of the heat-sensitive layer coating solution on the lithographic printing plate support obtained above using a bar coater was 0.00. 7g / m ² And dried in an oven at 100 ° C. for 60 seconds to form a heat sensitive layer to obtain a lithographic printing plate precursor.
[0187]
<Thermosensitive layer coating solution composition>
・ 25 g of microcapsule solution described later (5 g of solid content)
・ Trimethylolpropane triacrylate 3g
-0.3 g of infrared absorbing dye (I-32) described herein
・ Water 60g
1-methoxy-2-propanol 1g
[0188]
<Microcapsule>
40 g of xylene diisocyanate, 10 g of trimethylolpropane diacrylate, 10 g of a copolymer of allyl methacrylate and butyl methacrylate (molar ratio 7/3) and 0.1 g of a surfactant (Pionin A41C, manufactured by Takemoto Yushi Co., Ltd.) are dissolved in 60 g of ethyl acetate. To obtain an oil phase component. On the other hand, 120 g of a 4% aqueous solution of polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.) was prepared and used as an aqueous phase component. The oil phase component and the aqueous phase component were put into a homogenizer and emulsified at 10,000 rpm for 10 minutes. Thereafter, 40 g of water was added, stirred at room temperature for 30 minutes, and further stirred at 40 ° C. for 3 hours to obtain a microcapsule solution. The solid content concentration of the obtained microcapsule liquid was 20% by mass, and the average particle size of the microcapsules was 0.5 μm.
[0189]
(P) Formation of thermosensitive layer-2
Thermal positive type image recording layer
On the lithographic printing plate support after the alkali metal silicate treatment obtained as described above, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form a coating film. The coating amount of the coating after drying is 10 mg / m ² Met.
[0190]
<Undercoat liquid composition>
・ The following polymer compound 0.2g
・ Methanol 100g
・ Water 1g
[0191]
[Chemical Formula 10]

[0192]
Further, 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 which was undercoated was 1.7 g / m. ² And dried to form a heat sensitive layer (thermal positive type image recording layer) to obtain a lithographic printing plate precursor.
[0193]
<Thermosensitive layer coating solution composition>
・ Novolak resin (m-cresol / p-cresol = 60/40, weight average molecular weight 7,000, containing 0.5% by mass of unreacted cresol) 1.0 g
-Cyanine dye A0.1g represented by the following structural formula
・ Tetrahydrophthalic anhydride 0.05g
・ 0.002 g of p-toluenesulfonic acid
-0.02 g of 6-hydroxy-β-naphthalene sulfonic acid counterion of ethyl violet
-Fluorosurfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0.05 g
・ Methyl ethyl ketone 12g
[0194]
Embedded image

[0195]
1. Observation of coverage ratio and anodic oxide pore diameter by inorganic compound layer on lithographic printing plate support surface
For each lithographic printing plate precursor, the surface of the support in the non-image area after the development treatment was subjected to a scanning electron microscope (S-900, manufactured by Hitachi, Ltd.) with an acceleration voltage of 12 kV and a magnification of 150,000. The area ratio in a range in which the pores of the anodized film were not visible was obtained from the SEM photograph observed and taken as the coverage ratio.
[0196]
2. Measurement of grain shape characteristics
(1) Average opening diameter of medium wave structure
After the pore-wide treatment, before the application of the inorganic compound particles, the surface of the support was photographed at a magnification of 2000 times from directly above using an SEM, and in the obtained SEM photograph, the medium wave structure in which the periphery of the pit was connected in a ring shape 50 pits (medium wave pits) were extracted, and the diameter was read to obtain the opening diameter, and the average opening diameter was calculated.
[0197]
(2) Average aperture diameter of small wave structure
The surface of the support was photographed at a magnification of 50000 times from directly above using a high-resolution SEM, 50 small-wave structure pits (small-wave pits) were extracted from the obtained SEM photograph, and the diameter was read as the opening diameter. The average opening diameter was calculated.
[0198]
3. Sensitivity of planographic printing plate precursor
Each lithographic printing plate precursor was subjected to image exposure at 2400 dpi after adjusting various parameters (Sr, Sd, bmslope, and bmcurve) with a CREO plate setter Trendsetter 3244F (192 channel multi-beam mounted). The exposure was performed by changing the drum rotation speed and output stepwise. After exposure, the amount of energy (mJ / cm) that can be developed on a printing machine to form a 1% halftone dot ² ) Was defined as the sensitivity of the planographic printing plate precursor. The results are shown in Table 1.
[0199]
4). Printing durability and stain resistance (payment)
Each exposed lithographic printing plate precursor was attached to a printing machine, supplied with fountain solution, and then developed on the printing machine by supplying ink, followed by printing. Here, a printing press Sprint made by Komori Printing Co., Ltd. is used as a printing machine, Geos ink made by Dainippon Ink and Chemicals is used as ink, and a dampening made by Fuji Photo Film Co., Ltd. is used as a fountain solution. A mixture of 90 vol% water EU-3 (1: 100) and 10 vol% isopropanol was used, and high quality paper was used as the paper to be printed. Printing was performed under the above-mentioned conditions, and the number of printed sheets was measured until the ink did not deposit on the image area, and the printing durability was evaluated. The printing endurance results are shown in Table 1 as a percentage in comparison with 100% as the reference number.
[0200]
In addition, the planographic printing plate is attached to the printing press, and the supply of dampening water, the supply of ink, and the supply of paper are started at the same time. The number of damaged paper sheets (the number of sheets to be paid) until the image area was formed was evaluated as the stain resistance. The smaller the number of waste paper, the better. The results are shown in Table 1 in terms of the actual number of waste paper.
[0201]
As shown in Table 1, in Comparative Examples 5 to 9 in which the medium wave structure and the small wave structure are not superimposed, the coverage ratio of the inorganic compound particles to the micropores is lowered, the sensitivity is lowered, the adhesion is insufficient, and the resistance is reduced. The printing has deteriorated. In Comparative Example 1 in which the long diameter of the inorganic compound particles is larger than the small wave average opening diameter, the coverage is clearly reduced as compared with Example 4, and the sensitivity and printing durability are insufficient. The comparative example 3 also showed the same tendency.
If the major axis of the inorganic compound is smaller than the pore diameter of the anodized film as in Comparative Examples 2 and 4, the coverage is apparently improved, but the sensitivity is greatly reduced. On the other hand, Example 10 in which the major axis of the inorganic compound is larger than the pore diameter of the anodized film has improved sensitivity and printing durability.
[0202]
[Table 1]

[0203]
[Table 2]

[0204]
5). Exposure and development of thermal positive type image recording layer
Using a TrendSetter 3244 manufactured by CREO equipped with a semiconductor laser with an output of 500 mW and a wavelength of 830 nm and a beam diameter of 17 μm (1 / e 2), a lithographic printing plate precursor was scanned at a main scanning speed of 5 m / second and a plate surface energy amount of 140 mJ / cm. ² And imagewise exposure. Then, D-sorbite / potassium oxide K, which is a combination of non-reducing sugar and base ₂ Development processing was performed using an alkaline developer in which a predetermined compound was added to 1 L of an aqueous solution containing 5.0% by mass of a potassium salt of O and 0.015% by mass of Orphine AK-02 (manufactured by Nissin Chemical). . The development processing was performed using an automatic processor PS900NP (Fuji Photo Film Co., Ltd.) filled with the alkali developer under the conditions of a development temperature of 25 ° C. and 12 seconds. After completion of the development treatment, a lithographic printing plate in which plate making was completed was obtained through a water washing step and treatment with a gum (GU-7 (1: 1)).
[0205]
6). Evaluation of lithographic printing plate precursors with thermal positive type image recording layer
The sensitivity, printing durability and stain resistance of the lithographic printing plate precursor obtained above were evaluated under the above conditions, and the results are shown in Table 2. In addition, the thing with the same number shown in Table 1 was used for the thing with the same Example and comparative example number as a lithographic printing plate support.
[0206]
[Table 3]

[0207]
【The invention's effect】
As described above, the lithographic printing plate support and the lithographic printing plate precursor of the present invention have a specific structure on the micropores of an anodized film having a small wave structure and a medium wave structure as a thermal type lithographic printing plate precursor. By providing inorganic compound particles, preferably by treating the inorganic compound particles with a treatment solution capable of dissolving the inorganic compound particles, and fusing the inorganic compound particles, the heat insulating effect by the inorganic compound layer and the heat insulating effect by the voids of the micropores Can be included. Therefore, heat diffusion from the heat-sensitive layer to the aluminum support is sufficiently suppressed, and heat is efficiently used for image formation. Further, since the penetration of the heat sensitive layer component and ink into the micropores is suppressed, the stain resistance is improved. Further, since the adhesion between the inorganic compound particles and the aluminum plate having the anodized film is improved by limiting the average opening diameter of the small wave and the long diameter of the inorganic compound particles, the printing durability is improved.
Therefore, according to the present invention, high sensitivity, excellent printing durability, and the occurrence of stains in non-image areas are suppressed, so that it is suitable for both the lithographic printing plate precursors of the thermal positive type and the thermal negative type. Furthermore, a support for a lithographic printing plate that can be suitably used for an on-press development (non-processing) type lithographic printing plate precursor can be obtained, which is extremely useful.
[Brief description of the drawings]
FIG. 1 is a side view showing a concept of a brush graining process used in a mechanical surface roughening process in producing a lithographic printing plate support of the present invention.
FIG. 2 is a side view showing an example of a radial cell in an electrochemical surface roughening treatment using alternating current in the production of a lithographic printing plate support of the present invention.
FIG. 3 is a schematic view of an anodizing apparatus used for anodizing treatment in the production of a lithographic printing plate support of the present invention.
FIG. 4 is a schematic diagram showing the relationship between the pore diameter of the anodized film of the present invention and the long diameter of inorganic compound particles.
FIG. 5 is a schematic diagram showing the relationship between the average aperture diameter of a small wave structure which is a grain shape of the support of the present invention and the major axis of inorganic compound particles.
[Explanation of symbols]
1 Aluminum plate
2, 4 Roller brush
3 Polishing slurry
5, 6, 7, 8 Support roller
11 Aluminum plate
12 Radial drum roller
13a, 13b Main pole
14 Electrolytic treatment liquid
15 Electrolyte supply port
16 slits
17 Electrolyte passage
18 Auxiliary anode
19a, 19b Thyristor
20 AC power supply
40 Main electrolytic cell
50 Auxiliary anode tank
410 Anodizing equipment
412 Feeding tank
414 Electrolytic treatment tank
416 Aluminum plate
418, 426 electrolyte
420 Feeding electrode
422, 428 Roller
424 Nip roller
430 Electrolytic electrode
432 tank wall
434 DC power supply
101 Support for lithographic printing plate
102 Aluminum plate
103 Anodized film layer
104 Micropore (in the anodized film layer)
105 Internal diameter of micropore
106 Inorganic compound particles

Claims (4)

A lithographic printing plate support obtained by subjecting an aluminum plate to a surface roughening treatment and an anodizing treatment, having a medium wave structure with an average opening diameter of 0.5 to 5 μm and an average opening diameter of 0.01 to 0.00 on the surface. A roughened structure is formed by superimposing a 2 μm small wave structure, and is larger than the average pore diameter of the surface of the anodized film on the anodized film and less than the average aperture diameter of the small wave structure existing on the surface. A support for a lithographic printing plate, comprising inorganic compound particles having an average major axis. The lithographic printing plate support according to claim 1, wherein the inorganic compound particles are fixed with a compound containing at least one selected from the group consisting of fluorine, phosphorus and silicon. The lithographic printing plate support according to claim 1 or 2, wherein the roughened structure further overlaps a large wave structure having an average wavelength of 5 to 100 µm. A lithographic printing plate precursor comprising a lithographic printing plate support according to any one of claims 1 to 3 and a heat-sensitive layer that can be developed with water after exposure.

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