JP7055821B2 - Machine-developed lithographic printing plate original plate, lithographic printing plate manufacturing method, machine-developed lithographic printing plate dummy plate, and printing method - Google Patents

Description

The present invention relates to an on-machine development type lithographic printing plate original plate, a method for producing a lithographic printing plate, an on-machine developing type lithographic printing plate dummy plate, and a printing method.

Generally, a lithographic printing plate comprises a lipophilic image portion that receives ink and a hydrophilic non-image portion that receives dampening water in the printing process. In flat plate printing, the property that water and oil-based ink repel each other is used to make the oil-based image part of the flat plate printing plate an ink receiving part and the hydrophilic non-image part a dampening water receiving part (ink non-receptive part). ), This is a method in which a difference in the adhesiveness of the ink is generated on the surface of the flat plate printing plate, the ink is inlaid only on the image portion, and then the ink is transferred to an object to be printed such as paper for printing.

Currently, in a plate making process for producing a lithographic printing plate from a lithographic printing plate original plate, image exposure by CTP (computer to plate) technology is performed. That is, the image exposure is performed by scanning exposure directly to the lithographic printing plate precursor using a laser or a laser diode without using a lith film.

On the other hand, due to growing interest in the global environment, environmental problems related to waste liquid associated with wet processing such as development processing have been highlighted in the plate making of lithographic printing plate original plates, and along with this, the development processing has been simplified or eliminated. It is oriented. As one of the simple development processes, a method called "on-machine development" has been proposed. In-machine development is a method in which a lithographic printing plate precursor is exposed to an image, then attached to the printing machine as it is without performing the conventional wet development process, and the non-image portion of the image recording layer is removed at the initial stage of the normal printing process. be.

When printing using a lithographic printing plate, when printing on paper smaller than the size of the printing plate such as a normal sheet-fed printing press, the edge of the printing plate is located outside the paper surface, so the edge is printed. It does not affect the quality. However, when printing continuously on roll-shaped paper using a rotary press such as newspaper printing, the edge of the printing plate is inside the roll paper surface, so the ink adhering to the edge is transferred to the paper. Linear stains (edge stains) are generated, which significantly impairs the commercial value of printed matter.

For the purpose of suppressing the occurrence of the edge stain, Patent Document 1 describes that the plate surface on the image recording layer side of the two opposite side surfaces of the lithographic printing plate original plate having the support and the image recording layer is hydrophilic. A hydrophilized region formed by the chemical conversion component is formed, and the hydrophilization component contained in the region A of the image recording layer side plate surface up to 3 mm from the end of the two opposite side surfaces of the lithographic printing plate original plate to the inside. A laminate of lithographic printing plate precursors having a content per unit area of 10 mg / m ² or more higher than the content per unit area of a hydrophilic component in a region other than the region A has been proposed.

Japanese Patent Application Laid-Open No. 2017-19206

In the lithographic printing plate original plate described in Patent Document 1, in order to suppress the occurrence of edge stains, the water-soluble compound in the end region A is provided by means such as applying a coating liquid containing the hydrophilic component. It is characterized in that the content is increased by 10 mg / m ² or more as compared with the content of the hydrophilizing component in the region other than the end region A.
However, when a hydrophilization treatment such as applying a coating liquid containing a hydrophilic component is applied to the edge region of the lithographic printing plate original plate, the image forming property is deteriorated in the hydrophilized edge region. Was found to occur. This is due to the fact that the mechanical strength of the image recording layer is reduced by the hydrophilization treatment and the adhesion between the image recording layer and the support is reduced, so that during on-machine development, It is considered that the cause is that the image recording layer in the edge region is not retained and is removed together with the non-image region.

The problem to be solved by the present invention is an on-machine developing lithographic printing plate that exhibits good edge stain prevention even after long-term storage without deteriorating characteristics such as image formability and on-machine developability at the edges. It is an object of the present invention to provide a method for producing a lithographic printing plate using an original plate and a machine-developed lithographic printing plate original plate.
Further, the problem to be solved by the present invention is an on-machine developing type lithographic printing plate original plate dummy plate showing good edge stain prevention even after long-term storage without deteriorating characteristics such as on-machine developability. It is to provide a printing method.

Ｋ１及びＫ２中、Ｒ ^Ｋ１ 、Ｒ ^Ｋ２ 、Ｒ ^Ｋ４ 、Ｒ ^Ｋ５ 、Ｒ ^Ｋ６ 及びＲ ^Ｋ７ は、それぞれ独立に、単結合又は炭素数１～３の直鎖アルキレン基を表し、Ｒ ^Ｋ３ は（１＋ｍ）価の有機基を表し、Ｒ ^Ｋ８ は（２＋ｎ）価の有機基を表し、Ｘはそれぞれ独立に、（－ＣＨ＜）又は（－Ｎ＜）を表し、Ｙ ^Ｋ１ ～Ｙ ^Ｋ６ はそれぞれ独立に、－Ｃ（＝Ｏ）ＯＭで表される一価の基を表し、Ａはカルボキシ基を表し、ｍは０～２の整数を表し、ｎは０～４の整数を表し、Ｍは、それぞれ独立に、水素原子、金属原子、又はアンモニウム基を表す。
［３］
上記支持体吸着性を有する化合物を含有する層における上記支持体吸着性を有する化合物の含有量が２０～１５０ｍｇ／ｍ ^２ である［１］又は［２］に記載の機上現像型平版印刷版原版。
［４］
上記支持体吸着性を有する化合物を含有する層が更に界面活性剤を含有する［１］～［３］のいずれか１項に記載の機上現像型平版印刷版原版。
［５］
上記支持体吸着性を有する化合物を含有する層が更に水溶性ポリマーを含有する［１］～［４］のいずれか１項に記載の機上現像型平版印刷版原版。
［６］
上記化合物がオキソ酸又はその塩である［１］～［５］のいずれか１項に記載の機上現像型平版印刷版原版。
［７］
上記化合物が、リン酸、ポリリン酸、メタリン酸、第一リン酸アンモニウム、第二リン酸アンモニウム、リン酸二水素ナトリウム、リン酸一水素ナトリウム、第一リン酸カリウム、第二リン酸カリウム、トリポリリン酸ナトリウム、ピロリン酸カリウム、ヘキサメタリン酸ナトリウム、ホスフィン酸、エチルホスホン酸、プロピルホスホン酸、ｉ－プロピルホスホン酸、ブチルホスホン酸、ヘキシルホスホン酸、オクチルホスホン酸、ドデシルホスホン酸、オクタデシルホスホン酸、２－ヒドロキシエチルホスホン酸及びこれらのナトリウム塩又はカリウム塩、アルキルホスホン酸モノアルキルエステル及びこれらのナトリウム塩又はカリウム塩、アルキレンジホスホン酸及びこれらのナトリウム塩又はカリウム塩、ヒドロキシエチリデンジホスホン酸、ポリビニルホスホン酸、ｐ－トルエンスルホン酸、ｐ－トルエンスルホン酸ナトリウム、スルホフタル酸、又はクエン酸である［１］～［５］のいずれか１項に記載の機上現像型平版印刷版原版。
［８］
上記化合物が下記式１で表わされる化合物である［１］～［７］のいずれか１項に記載の機上現像型平版印刷版原版。

式１中、ｎは、２～１０の整数を表し、Ｒ１、Ｒ２、Ｒ３は、それぞれ独立に、水素原子、アルカリ金属塩、アルカリ土類金属塩、アンモニウム塩、アルキル基又はアルキレンオキシド基を表す。
［９］
上記化合物がリン酸、ポリリン酸、ホスホン酸もしくはホスフィン酸又はこれらの塩である［１］～［８］のいずれか１項に記載の機上現像型平版印刷版原版。
［１０］
上記ダレ形状が、ダレ量Ｘが２５～１５０μｍ、ダレ幅Ｙが７０～３００μｍである［１］～［９］のいずれか１項に記載の機上現像型平版印刷版原版。
［１１］
上記平版印刷版原版のダレ幅Ｙに相当する領域の上記陽極酸化皮膜の表面に存在するクラックの面積率が２０％以下である［１０］に記載の機上現像型平版印刷版原版。
［１２］
上記画像記録層が、ポリマー粒子を含有する［１］～［１１］のいずれか１項に記載の機上現像型平版印刷版原版。
［１３］
上記ポリマー粒子が、スチレン化合物に由来するモノマー単位、及び／又は、（メタ）アクリロニトリル化合物に由来するモノマー単位を含むポリマーの粒子である［１２］に記載の機上現像型平版印刷版原版。
［１４］
［１］～［１３］のいずれか１項に記載の機上現像型平版印刷版原版を、赤外線レーザーにより画像露光する工程と、印刷機上で印刷インキ及び湿し水から選ばれる少なくとも１つにより、画像記録層の未露光部分を除去する工程とを含む平版印刷版の作製方法。
［１５］
陽極酸化皮膜を有するアルミニウム支持体上にポリマー層を有する機上現像型平版印刷版ダミー版であって、上記平版印刷版ダミー版は端部にダレ形状を有し、上記ポリマー層の上に支持体吸着性を有する化合物を含有する層を有し、上記化合物の含有量が上記支持体吸着性を有する化合物を含有する層の面内において実質的に同じであり、
上記化合物の分子量が１，０００以下であり、
上記支持体吸着性を有する化合物を含有する層における上記支持体吸着性を有する化合物の含有量が、２０ｍｇ／ｍ ^２ 以上である機上現像型平版印刷版ダミー版（但し、アルミニウム支持体と、前記アルミニウム支持体上に直接的に形成された第１親水性層と、前記第１親水性層上に直接的に形成された第２親水性層とをこの順に有する平版印刷版ダミー版であって、前記第１親水性層及び前記第２親水性層の少なくとも一方が、３５０～８００ｎｍに吸収極大を有する着色剤を含み、前記第１親水性層が、支持体吸着性基と親水性基とを有する高分子化合物を含む、平版印刷版ダミー版を除く）。
［１６］
上記支持体吸着性を有する化合物を含有する層における上記支持体吸着性を有する化合物の含有量が２０～１５０ｍｇ／ｍ ^２ である［１５］に記載の機上現像型平版印刷版ダミー版。
［１７］
上記化合物が、リン酸、ポリリン酸、メタリン酸、第一リン酸アンモニウム、第二リン酸アンモニウム、リン酸二水素ナトリウム、リン酸一水素ナトリウム、第一リン酸カリウム、第二リン酸カリウム、トリポリリン酸ナトリウム、ピロリン酸カリウム、ヘキサメタリン酸ナトリウム、ホスフィン酸、エチルホスホン酸、プロピルホスホン酸、ｉ－プロピルホスホン酸、ブチルホスホン酸、ヘキシルホスホン酸、オクチルホスホン酸、ドデシルホスホン酸、オクタデシルホスホン酸、２－ヒドロキシエチルホスホン酸及びこれらのナトリウム塩又はカリウム塩、アルキルホスホン酸モノアルキルエステル及びこれらのナトリウム塩又はカリウム塩、アルキレンジホスホン酸及びこれらのナトリウム塩又はカリウム塩、ヒドロキシエチリデンジホスホン酸、ポリビニルホスホン酸、ｐ－トルエンスルホン酸、ｐ－トルエンスルホン酸ナトリウム、スルホフタル酸、又はクエン酸である［１５］又は［１６］に記載の機上現像型平版印刷版ダミー版。
［１８］
上記化合物がリン酸、ポリリン酸、ホスホン酸もしくはホスフィン酸又はこれらの塩である［１５］～［１７］のいずれか１項に記載の機上現像型平版印刷版ダミー版。
［１９］
［１５］～［１８］のいずれか１項に記載の機上現像型平版印刷版ダミー版、及び、アルミニウム支持体上に画像記録層を有する機上現像型平版印刷版原版を機上現像する工程を含む印刷方法。
［２０］
上記画像記録層が、ポリマー粒子を含有する［１９］に記載の印刷方法。
［２１］
上記ポリマー粒子が、スチレン及びアクリロニトリルを含む共重合体の粒子である［２０］に記載の印刷方法。
本発明は、上記［１］～［２１］に係る発明であるが、以下、それ以外の事項（例えば、下記（１）～（２４））についても記載している。 The means for solving the above problems are described below.
[1]
An on-machine development type lithographic printing plate original plate having an image recording layer on an aluminum support having an anodic oxide film, the lithographic printing plate original plate has a sagging shape at an end and is supported on the image recording layer. In-plane of the layer containing the compound having body-adsorbability (however, excluding ethylenediamine tetraacetic acid tetrasodium tetrahydrate) and the content of the compound is the compound having the support-adsorbing property. Is substantially the same in
The molecular weight of the above compound is 1,000 or less, and the molecular weight is 1,000 or less.
An on-machine developing type lithographic printing plate original plate in which the content of the compound having the support-adsorbing property in the layer containing the compound having the support-adsorbing property is 20 mg / m ² or more.
[2]
The on-machine development type lithographic printing plate original plate according to [1], which excludes the compound represented by the formula K1 or the formula K2 from the compounds having the support-adsorbing property.

In K1 and K2, ^{RK1 , RK2} , RK4 , ^RK5 , ^RK6 and ^RK7 each independently represent a single bond or a linear alkylene group having 1 to 3 carbon atoms, and ^RK3 is (1 + m). Valuable organic groups, ^RK8 represent (2 + n) valent organic groups, X independently represent (-CH <) or (-N <), Y ^K1 to Y ^K6 independently, respectively. -C (= O) represents a monovalent group represented by OM, A represents a carboxy group, m represents an integer of 0 to 2, n represents an integer of 0 to 4, and M represents an independent group. Represents a hydrogen atom, a metal atom, or an ammonium group.
[3]
The on-machine development type lithographic printing plate according to [1] or [2], wherein the content of the compound having the support-adsorbing property in the layer containing the compound having the support-adsorbing property is 20 to 150 mg / m ² . Original version.
[4]
The machine-developed lithographic printing plate original plate according to any one of [1] to [3], wherein the layer containing the compound having the support-adsorbing property further contains a surfactant.
[5]
The machine-developed lithographic printing plate original plate according to any one of [1] to [4], wherein the layer containing the compound having the support-adsorbing property further contains a water-soluble polymer.
[6]
The machine-developed lithographic printing plate original plate according to any one of [1] to [5], wherein the compound is an oxo acid or a salt thereof.
[7]
The above compounds are phosphoric acid, polyphosphoric acid, metaphosphoric acid, ammonium primary phosphate, ammonium secondary phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, potassium primary phosphate, potassium secondary phosphate, tripolyline. Sodium acid, potassium pyrophosphate, sodium hexametaphosphate, phosphinic acid, ethylphosphonic acid, propylphosphonic acid, i-propylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, dodecylphosphonic acid, octadecylphosphonic acid, 2- Hydroxyethylphosphonic acid and its sodium or potassium salt, alkylphosphonic acid monoalkyl ester and their sodium or potassium salt, alkylene diphosphonic acid and their sodium or potassium salt, hydroxyethylidene diphosphonic acid, polyvinylphosphonic acid , P-toluenesulfonic acid, sodium p-toluenesulfonate, sulfophthalic acid, or citric acid according to any one of [1] to [5].
[8]
The machine-developed lithographic printing plate original plate according to any one of [1] to [7], wherein the compound is a compound represented by the following formula 1.

In formula 1, n represents an integer of 2 to 10, and R1, R2, and R3 independently represent a hydrogen atom, an alkali metal salt, an alkaline earth metal salt, an ammonium salt, an alkyl group, or an alkylene oxide group. ..
[9]
The machine-developed flat plate printing plate original plate according to any one of [1] to [8], wherein the compound is phosphoric acid, polyphosphoric acid, phosphoric acid, phosphinic acid, or a salt thereof.
[10]
The machine-developed lithographic printing plate original plate according to any one of [1] to [9], wherein the sagging shape has a sagging amount X of 25 to 150 μm and a sagging width Y of 70 to 300 μm.
[11]
The on-machine development type lithographic printing plate original plate according to [10], wherein the area ratio of cracks existing on the surface of the anodic oxide film in the region corresponding to the sagging width Y of the lithographic printing plate original plate is 20% or less.
[12]
The machine-developed lithographic printing plate original plate according to any one of [1] to [11], wherein the image recording layer contains polymer particles.
[13]
The machine-developed flat plate printing plate original plate according to [12], wherein the polymer particles are polymer particles containing a monomer unit derived from a styrene compound and / or a monomer unit derived from a (meth) acrylonitrile compound.
[14]
A step of image-exposing the machine-developed lithographic printing plate precursor according to any one of [1] to [13] with an infrared laser, and at least one selected from printing ink and dampening water on the printing machine. A method for producing a lithographic printing plate, which comprises a step of removing an unexposed portion of an image recording layer.
[15]
An on-machine development type lithographic printing plate dummy plate having a polymer layer on an aluminum support having an anodic oxide film, the lithographic printing plate dummy plate has a sagging shape at an end and is supported on the polymer layer. It has a layer containing a compound having body adsorptivity, and the content of the compound is substantially the same in the plane of the layer containing the compound having the support adsorbability.
The molecular weight of the above compound is 1,000 or less, and the molecular weight is 1,000 or less.
The on-board development type flat plate printing plate dummy plate (provided that the aluminum support and the aluminum support) have a content of the compound having the support-adsorbing property of 20 mg / m ² or more in the layer containing the compound having the support-adsorbing property. A flat plate printing plate dummy plate having a first hydrophilic layer directly formed on the aluminum support and a second hydrophilic layer directly formed on the first hydrophilic layer in this order. The first hydrophilic layer and at least one of the second hydrophilic layers contain a colorant having an absorption maximum at 350 to 800 nm, and the first hydrophilic layer is a support-adsorbing group and a hydrophilic group. (Excluding the flat plate printing plate dummy plate) containing a polymer compound having and.
[16]
The on-machine development type lithographic printing plate dummy plate according to [15], wherein the content of the compound having the support-adsorbing property in the layer containing the compound having the support-adsorbing property is 20 to 150 mg / m ² .
[17]
The above compounds are phosphoric acid, polyphosphoric acid, metaphosphoric acid, ammonium primary phosphate, ammonium secondary phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, potassium primary phosphate, potassium secondary phosphate, tripolyline. Sodium acid, potassium pyrophosphate, sodium hexametaphosphate, phosphinic acid, ethylphosphonic acid, propylphosphonic acid, i-propylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, dodecylphosphonic acid, octadecylphosphonic acid, 2- Hydroxyethylphosphonic acid and its sodium or potassium salt, alkylphosphonic acid monoalkyl ester and their sodium or potassium salt, alkylene diphosphonic acid and their sodium or potassium salt, hydroxyethylidene diphosphonic acid, polyvinylphosphonic acid , P-toluenesulfonic acid, sodium p-toluenesulfonate, sulfophthalic acid, or citric acid [15] or [16]. The machine-developed flat plate printing plate dummy plate.
[18]
The machine-developed flat plate printing plate dummy plate according to any one of [15] to [17], wherein the compound is phosphoric acid, polyphosphoric acid, phosphoric acid, phosphinic acid, or a salt thereof.
[19]
The machine-developed lithographic printing plate dummy plate according to any one of [15] to [18] and the machine-developed lithographic printing plate original plate having an image recording layer on an aluminum support are machine-developed. Printing method including steps.
[20]
The printing method according to [19], wherein the image recording layer contains polymer particles.
[21]
The printing method according to [20], wherein the polymer particles are copolymer particles containing styrene and acrylonitrile.
The present invention is the invention according to the above [1] to [21], but other matters (for example, the following (1) to (24)) are also described below.

(1) An on-board development type lithographic printing plate original plate having an image recording layer on an aluminum support having an anodic oxide film, the lithographic printing plate original plate has a sagging shape at an end, and the image recording layer On-machine development type lithographic printing plate having a layer containing a compound having a support adsorptive property on the surface, and the content of the compound is substantially the same in the plane of the layer containing the compound having the support adsorbability. Print plate original plate.
(2) The machine-developed lithographic printing plate original plate according to (1), wherein the compound has a molecular weight of 1,000 or less.
(3) The machine-developed lithographic printing plate original plate according to (1) or (2), wherein the layer containing the compound having the support-adsorbing property further contains a surfactant.
(4) The machine-developed lithographic printing plate original plate according to any one of (1) to (3), wherein the layer containing the compound having the support-adsorbing property further contains a water-soluble polymer.
(5) The machine-developed lithographic printing plate original plate according to any one of (1) to (4), wherein the compound is an oxo acid or a salt thereof.
(6) The machine-developed lithographic printing plate original plate according to any one of (1) to (5), wherein the compound is a compound represented by the following formula 1.

In formula 1, n represents an integer of 2 to 10, and R1, R2, and R3 independently represent a hydrogen atom, an alkali metal salt, an alkaline earth metal salt, an ammonium salt, an alkyl group, or an alkylene oxide group. ..
(7) The machine-developed flat plate printing plate original plate according to any one of (1) to (6), wherein the compound is phosphoric acid, polyphosphoric acid, phosphoric acid, phosphinic acid or a salt thereof.
(8) The machine-developed lithographic printing plate original plate according to any one of (1) to (7), wherein the content of the compound is 20 to 150 mg / m ² .
(9) The machine-developed lithographic printing plate original plate according to any one of (1) to (8), wherein the sagging shape has a sagging amount X of 25 to 150 μm and a sagging width Y of 70 to 300 μm.
(10) The on-machine development type lithographic printing plate original plate according to (9), wherein the area ratio of cracks existing on the surface of the anodic oxide film in the region corresponding to the sagging width Y of the lithographic printing plate original plate is 20% or less. ..
(11) The machine-developed lithographic printing plate original plate according to (10), wherein the area ratio of the crack is 10% or less.
(12) The machine-developed lithographic printing plate original plate according to any one of (1) to (11), wherein the image recording layer contains polymer particles.
(13) The machine-developed flat plate printing plate according to (12), wherein the polymer particles are polymer particles containing a monomer unit derived from a styrene compound and / or a monomer unit derived from a (meth) acrylonitrile compound. Original version.
(14) The machine-developed lithographic printing plate original plate according to any one of (1) to (13), wherein the image recording layer contains a polymerization initiator, an infrared absorber and a polymerizable compound.
(15) The process of image-exposing the machine-developed lithographic printing plate precursor according to any one of (1) to (14) with an infrared laser, and the printing ink and dampening water selected on the printing machine. A method for producing a lithographic printing plate, which comprises a step of removing an unexposed portion of an image recording layer by at least one.

(16)
An on-machine development type lithographic printing plate dummy plate having a polymer layer on an aluminum support having an anodic oxide film, the lithographic printing plate dummy plate has a sagging shape at an end and is supported on the polymer layer. On-machine development type lithographic printing plate dummy having a layer containing a compound having body-adsorbability and having a content of the compound substantially the same in the plane of the layer containing the compound having support adsorbability. Edition.
(17)
A printing method comprising the steps of on-machine developing a machine-developing lithographic printing plate dummy plate according to (16) and a machine-developing lithographic printing plate original plate having an image recording layer on an aluminum support.
(18)
The printing method according to (17), wherein the image recording layer contains a polymerization initiator containing an organoboron-containing anion.
(19)
The printing method according to (18), wherein the polymerization initiator is an iodonium compound containing an organoboron-containing anion and a diallyl iodonium cation.
(20)
The printing method according to any one of (17) to (19), wherein the image recording layer contains polymer fine particles.
(21)
The printing method according to (20), wherein the polymer fine particles are copolymer particles containing styrene and acrylonitrile.
(22)
The printing method according to (20), wherein the polymer fine particles are microgels.
(23)
The printing method according to any one of (17) to (22), wherein the on-machine development type lithographic printing plate original plate has an undercoat layer between the aluminum support and the image recording layer.
(24)
The printing method according to any one of (17) to (23), wherein the on-machine development type lithographic printing plate original plate has a protective layer on the image recording layer.

According to the present invention, an on-machine developing type lithographic printing plate original plate and a machine that show good edge stain prevention even after long-term storage without deteriorating characteristics such as image formability and on-machine developability of edges. It is possible to provide a method for producing a lithographic printing plate using a top-developing lithographic printing plate original plate.
Further, according to the present invention, there is provided an on-machine developing type lithographic printing plate, an original plate dummy plate, and a printing method, which show good edge stain prevention even after long-term storage without deteriorating characteristics such as on-machine developability. can do.

It is a schematic diagram which shows the cross-sectional shape of the end portion of a lithographic printing plate original plate. It is a conceptual diagram which shows an example of the cutting part of a slitter device.

Hereinafter, embodiments for carrying out the invention will be described in detail.
In the present specification, regarding the notation of a group in the compound represented by the formula, if substituted or unsubstituted is not described, and if the group can further have a substituent, unless otherwise specified. , Not only unsubstituted groups but also groups having substituents are included. For example, if there is a description in the formula that "R represents an alkyl group, an aryl group or a heterocyclic group", "R is an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aryl group, a substituted aryl group, or an unsubstituted". It means "representing a heterocyclic group or a substituted heterocyclic group".
As used herein, the term "(meth) acrylate" means "at least one of acrylate and methacrylate". The same applies to "(meth) acryloyl group", "(meth) acrylic acid", "(meth) acrylic resin" and the like.

[In-machine development type lithographic printing plate original plate]
The on-machine development type lithographic printing plate original plate according to the present invention has at least an aluminum support having an anodic oxide film and an image recording layer, and has a sagging shape at the end of the lithographic printing plate original plate, and is an image recording layer. On-machine development type lithographic printing plate having a layer containing a compound having a support adsorptive property on the surface, and the content of the compound is substantially the same in the plane of the layer containing the compound having the support adsorbability. It is a print version original plate.

[Aluminum support with anodic oxide film]
An aluminum support having an anodic oxide film constituting the machine-developed lithographic printing plate original plate will be described.

The aluminum plate used for the aluminum support is made of a metal whose main component is aluminum, which is dimensionally stable, that is, aluminum or an aluminum alloy. It is preferably selected from a pure aluminum plate and an alloy plate containing aluminum as a main component and a trace amount of foreign elements.

Foreign elements contained in aluminum alloys include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The content of foreign elements in the alloy is 10% by mass or less. A pure aluminum plate is preferable, but since completely pure aluminum is difficult to manufacture due to smelting technology, an alloy plate containing a slight amount of different elements may be used. The composition of the aluminum plate used for the aluminum support is not specified, and conventionally known aluminum plates such as JIS A 1050, JIS A 1100, JIS A 3103, and JIS A 3005 may be appropriately used. I can.
The thickness of the aluminum plate is preferably about 0.1 to 0.6 mm.

The anodic oxide film means an anodic aluminum film formed on the surface of an aluminum plate by anodization treatment, which is substantially perpendicular to the surface of the film and has ultrafine pores (also referred to as micropores) in which individuals are uniformly distributed. .. The micropores extend from the surface of the anodic oxide film in the thickness direction.

[Manufacturing method of aluminum support]
The method for manufacturing the aluminum support is not particularly limited. Preferred embodiments of the method for manufacturing the aluminum support include a step of roughening the aluminum plate (roughening treatment step), a step of anodizing the roughened aluminum plate (anodizing step), and a step of anodizing the roughened aluminum plate. Examples thereof include a method including a step (pore wide treatment step) of contacting an aluminum plate having an anodized film obtained in the anodizing step with an acid aqueous solution or an alkaline aqueous solution to increase the diameter of micropores in the anodized film. ..

Each process will be described in detail below.

<Roughening process>
The roughening treatment step is a step of applying a roughening treatment including an electrochemical roughening treatment to the surface of the aluminum plate. The roughening treatment step is preferably carried out before the anodizing treatment step described later, but it may not be carried out if the surface of the aluminum plate already has a preferable surface shape.

The roughening treatment may be performed only by the electrochemical roughening treatment, but the roughening treatment may be performed by combining the electrochemical roughening treatment with the mechanical roughening treatment and / or the chemical roughening treatment. May be good.
When the mechanical roughening treatment and the electrochemical roughening treatment are combined, it is preferable to perform the electrochemical roughening treatment after the mechanical roughening treatment.

The electrochemical roughening treatment is preferably carried out in an aqueous solution of nitric acid or hydrochloric acid.

The mechanical roughening treatment is generally performed for the purpose of making the surface of the aluminum plate a surface roughness Ra: 0.35 to 1.0 μm.
The conditions of the mechanical roughening treatment are not particularly limited, but can be applied, for example, according to the method described in Japanese Patent Publication No. 50-40047. The mechanical roughening treatment can be performed by a brush grain treatment using a Pamiston suspension or by a transfer method.
Further, the chemical roughening treatment is not particularly limited, and can be performed according to a known method.

After the mechanical roughening treatment, it is preferable to perform the following chemical etching treatment.
The chemical etching treatment applied after the mechanical roughening treatment smoothes the uneven edge part of the surface of the aluminum plate, prevents ink from getting caught during printing, and improves the stain resistance of the lithographic printing plate. At the same time, it is performed to remove unnecessary substances such as abrasive particles remaining on the surface.
As the chemical etching process, etching with an acid or etching with an alkali is known, but as a method particularly excellent in terms of etching efficiency, a chemical etching process using an alkaline solution (hereinafter, also referred to as "alkali etching process"). ).

The alkaline agent used in the alkaline solution is not particularly limited, and examples thereof include caustic soda, caustic acid, sodium metasilicate, sodium carbonate, sodium aluminate, and sodium gluconate.
Further, the alkaline agent may contain aluminum ions. The concentration of the alkaline solution is preferably 0.01% by mass or more, more preferably 3% by mass or more, more preferably 30% by mass or less, and more preferably 25% by mass or less. preferable.
Further, the temperature of the alkaline solution is preferably room temperature or higher, more preferably 30 ° C. or higher, preferably 80 ° C. or lower, and even more preferably 75 ° C. or lower.

The etching amount is preferably 0.1 g / m ² or more, more preferably 1 g / m ² or more, and preferably 20 g / m ² or less, and 10 g / m ² or less. Is more preferable.
The processing time is preferably 2 seconds to 5 minutes according to the etching amount, and more preferably 2 to 10 seconds from the viewpoint of improving productivity.

When the alkaline etching treatment is performed after the mechanical roughening treatment, a chemical etching treatment (hereinafter, also referred to as "desmat treatment") is performed using a low-temperature acidic solution in order to remove the product produced by the alkaline etching treatment. It is preferable to apply.
The acid used in the acidic solution is not particularly limited, and examples thereof include sulfuric acid, nitric acid, and hydrochloric acid. The concentration of the acidic solution is preferably 1 to 50% by mass. The temperature of the acidic solution is preferably 20 to 80 ° C. When the concentration and temperature of the acidic solution are in this range, the spot-like stain resistance of the lithographic printing plate using the aluminum support is further improved.

The roughening treatment is a treatment in which a mechanical roughening treatment and a chemical etching treatment are performed as desired, and then an electrochemical roughening treatment is performed. However, the roughening treatment is performed without performing the mechanical roughening treatment. Even in the case of performing the target roughening treatment, the chemical etching treatment can be performed using an alkaline aqueous solution such as Kasei soda before the electrochemical roughening treatment. This makes it possible to remove impurities and the like existing near the surface of the aluminum plate.

The electrochemical roughening treatment is suitable for producing a lithographic printing plate having excellent printability because it is easy to impart fine irregularities (pits) to the surface of the aluminum plate.
The electrochemical roughening treatment is performed using direct current or alternating current in an aqueous solution mainly composed of nitric acid or hydrochloric acid.

Further, it is preferable to perform the following chemical etching treatment after the electrochemical roughening treatment. Smuts and intermetallic compounds are present on the surface of the aluminum plate after the electrochemical roughening treatment. In the chemical etching treatment performed after the electrochemical roughening treatment, it is preferable to first perform the chemical etching treatment (alkali etching treatment) using an alkaline solution in order to remove the smut particularly efficiently. As for the conditions of the chemical etching treatment using the alkaline solution, the treatment temperature is preferably 20 to 80 ° C., and the treatment time is preferably 1 to 60 seconds. Further, it is preferable to contain aluminum ions in the alkaline solution.

Further, after the chemical etching treatment using an alkaline solution after the electrochemical roughening treatment, a chemical etching treatment (desmat treatment) is performed using a low-temperature acidic solution in order to remove the product produced by the chemical etching treatment. Is preferable.
Further, even when the alkali etching treatment is not performed after the electrochemical roughening treatment, it is preferable to perform the desmat treatment in order to efficiently remove the smut.

The chemical etching treatment can be performed by a dipping method, a shower method, a coating method, or the like, and is not particularly limited.

<Anodizing process>
In the anodizing treatment step, the roughened aluminum plate is anodized to form an aluminum oxide film having micropores extending in the depth direction (thickness direction) on the surface of the aluminum plate. It is a process. By this anodic oxidation treatment, an anodic oxide film of aluminum having micropores is formed on the surface of the aluminum plate.

The anodizing treatment can be carried out by a method conventionally performed in this field, but manufacturing conditions are appropriately set so that the micropores can be finally formed. Specifically, the average diameter (average opening diameter) of the micropores formed in the anodic oxidation treatment step is usually about 4 to 14 nm, preferably 5 to 10 nm. Within the above range, micropores having a predetermined shape are easily formed, and the performance of the obtained lithographic printing plate original plate and lithographic printing plate is more excellent.

The depth of the micropores is usually about 10 nm or more and less than 100 nm, preferably 20 to 60 nm. Within the above range, micropores having a predetermined shape are easily formed, and the performance of the obtained lithographic printing plate original plate and lithographic printing plate is more excellent.

The pore density of the micropores is not particularly limited, but the pore density is preferably 50 to 4000 pieces / μm ² , and more preferably 100 to 3000 pieces / μm ² . Within the above range, the obtained lithographic printing plate has excellent printing durability and neglectability, and the on-machine developability of the lithographic printing plate original plate is excellent.

In the anodizing treatment step, an aqueous solution of sulfuric acid, phosphoric acid, oxalic acid, etc. can be mainly used as an electrolytic bath. In some cases, an aqueous solution or a non-aqueous solution obtained by using chromic acid, sulfamic acid, benzenesulphonic acid, etc. or a combination of two or more thereof may be used. By passing direct current or alternating current through the aluminum plate in the electrolytic bath, an anodic oxide film can be formed on the surface of the aluminum plate. The electrolytic bath may contain aluminum ions. The content of aluminum ions is not particularly limited, but is preferably 1 to 10 g / L.

The conditions for the anodizing treatment are appropriately set depending on the electrolytic solution used, but in general, the concentration of the electrolytic solution is 1 to 80% by mass (preferably 5 to 20% by mass), and the liquid temperature is 5 to 70 ° C. (preferably 5 to 20% by mass). (Preferably 10 to 60 ° C.), current density 0.5 to 60 A / dm ² (preferably 5 to 50 A / dm ² ), voltage 1 to 100 V (preferably 5 to 50 V), electrolysis time 1 to 100 seconds (preferably 5 to 100 seconds). A range of 5 to 60 seconds) is appropriate.

Among these anodizing treatments, the method described in British Patent No. 1,421,768 for anodizing in sulfuric acid at a high current density is particularly preferable.

<Pore wide processing process>
The pore-wide treatment step is a treatment (pore diameter enlargement treatment) for enlarging the diameter (pore diameter) of the micropores existing in the anodic oxide film formed by the anodic oxidation treatment step. This pore-wide treatment enlarges the diameter of the micropores and forms an anodic oxide film with micropores having a larger average diameter. It is appropriate that the average diameter of the micropores after the pore wide treatment is more than 10 nm and 100 nm or less. From the viewpoint of the balance between printing resistance, stain resistance, and image visibility, the average diameter of the micropores after the pore wide treatment is preferably 15 to 60 nm, more preferably 20 to 50 nm, and even more preferably 24 to 40 nm.

The pore-wide treatment is performed by bringing the aluminum plate obtained in the above anodizing treatment step into contact with an acid aqueous solution or an alkaline aqueous solution. The contact method is not particularly limited, and examples thereof include a dipping method and a spraying method. Above all, the dipping method is preferable.

When an alkaline aqueous solution is used in the pore wide treatment step, it is preferable to use at least one alkaline aqueous solution selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.1 to 5% by mass. After adjusting the pH of the alkaline aqueous solution to 11 to 13, the aluminum plate was immersed in the alkaline aqueous solution for 1 to 300 seconds (preferably 1 to 50 seconds) under the conditions of 10 to 70 ° C (preferably 20 to 50 ° C). It is appropriate to make contact. At this time, a metal salt of a polyvalent weak acid such as a carbonate, a borate, or a phosphate may be contained in the alkaline treatment liquid.

When an aqueous acid solution is used in the pore wide treatment step, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, or hydrochloric acid, or a mixture thereof. The concentration of the aqueous acid solution is preferably 1 to 80% by mass, more preferably 5 to 50% by mass. It is appropriate to bring the aluminum plate into contact with the acid aqueous solution for 1 to 300 seconds (preferably 1 to 150 seconds) under the condition that the liquid temperature of the acid aqueous solution is 5 to 70 ° C. (preferably 10 to 60 ° C.). Aluminum ions may be contained in the alkaline aqueous solution or the acid aqueous solution. The content of aluminum ions is not particularly limited, but is preferably 1 to 10 g / L.

<End pore wide processing process>
It is also preferable that the pore wide treatment step is carried out only in a partial region (end) on the support. By performing the pore-wide treatment not on the entire surface of the support but in a part of the area as described above, it is possible to prevent a decrease in scratch resistance.

As a method of performing the pore wide treatment only in a part of the area, the die coating method, the dip coating method, the air knife coating method, the curtain coating method, the roller coating method, the wire bar cord method, the gravure coating method, the slide coating method, and the inkjet coating method. A known method such as a method, a dispenser coating method, or a spray method can be used, but since it is necessary to apply an acid aqueous solution or an alkaline aqueous solution to a part of the support, the inkjet coating method or the dispenser coating method or the dispenser coating method can be used. The method is preferred. Further, it is preferable that the area to be applied corresponds to two opposite sides of the lithographic printing original plate after cutting.

The acid aqueous solution or the alkaline aqueous solution may be applied from the end portion of the support, may be applied to a position other than the end portion of the support, or these application positions may be combined. Further, in both the case of applying from the end of the support and the case of applying to a position other than the end of the support, it is preferable to apply in a strip shape having a certain width. The preferred coating width is 1 to 50 mm. It is preferable that the coating area is cut on the coating area of the coating width, and the coating area exists within 1 cm from the cut end portion. For cutting, one place on the coating area may be cut, or two places on the same coating area may be cut.

<Hydrophilic treatment process>
The method for producing an aluminum support may include a hydrophilization treatment step of performing a hydrophilic treatment after the pore wide treatment step. As the hydrophilization treatment, a known method disclosed in paragraphs 0109 to 0114 of JP-A-2005-254638 can be used.

Hydrophilization treatment is performed by immersing in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or by applying a hydrophilic vinyl polymer or a hydrophilic compound to form a hydrophilic undercoat layer. It is preferable to do so.

The hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. It can be done according to the methods and procedures.

The aluminum support is, if necessary, on the surface opposite to the image recording layer, the organic polymer compound described in JP-A-5-45885 or the silicon alkoxy compound described in JP-A-6-35174. It may have a back coat layer including the above.

[Image recording layer]
The image recording layer constituting the machine-developed lithographic printing plate original plate will be described. The image recording layer is a layer having a property that the non-image portion is removed by at least one selected from printing ink and dampening water on a printing machine. As the image recording layer, a known image recording layer constituting the on-machine development type lithographic printing plate original plate can be used.

According to one embodiment, the image recording layer preferably contains polymer particles.

<Polymer particles>
The polymer particles contribute to the improvement of on-machine developability. The polymer particles are preferably polymer particles that can convert the image recording layer into hydrophobic when heat is applied. The polymer particles are at least one selected from hydrophobic thermoplastic polymer particles, heat-reactive polymer particles, polymer particles having a polymerizable group, microcapsules containing a hydrophobic compound, and microgels (crosslinked polymer particles). Is preferable.

As the hydrophobic thermoplastic polymer particles, Research Disclosure No. 1 of January 1992. The hydrophobic thermoplastic polymer particles described in 33303, JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, JP-A-9-171250, European Patent No. 913647, etc. are preferable. Listed in.
Specific examples of the polymer constituting the hydrophobic thermoplastic polymer particles include ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinylcarbazole, and polyalkylene structure. Examples include homopolymers or copolymers of monomers such as acrylates or methacrylates or mixtures thereof. Preferred are copolymers containing polystyrene, styrene and acrylonitrile, polymethyl methacrylate. The average particle size of the hydrophobic thermoplastic polymer particles is preferably 0.01 to 2.0 μm.

Examples of the heat-reactive polymer particles include polymer particles having a heat-reactive group. The polymer particles having a heat-reactive group form a hydrophobic region by cross-linking by a heat reaction and the change of the functional group at that time.

The heat-reactive group in the polymer particles having a heat-reactive group may be a functional group that undergoes any reaction as long as a chemical bond is formed, and a polymerizable group is preferable. Examples include ethylenically unsaturated groups (eg, acryloyl group, methacryloyl group, vinyl group, allyl group, etc.) and cationically polymerizable groups (eg, vinyl group, vinyloxy group, epoxy group, oxetanyl group, etc.) that undergo a radical polymerization reaction. , Etc.), a functional group having an isocyanato group or a block thereof, an epoxy group, a vinyloxy group and an active hydrogen atom which is a reaction partner thereof (for example, an amino group, a hydroxy group, a carboxy group, etc.), and a condensation reaction. Preferable examples thereof include a carboxy group to be carried out, a hydroxy group or an amino group as a reaction partner, an acid anhydride for carrying out a ring-opening addition reaction, and an amino group or a hydroxy group to be a reaction partner.

Examples of the microcapsules include those in which all or part of the constituent components of the image recording layer are encapsulated in microcapsules, as described in JP-A-2001-277740 and JP-A-2001-277742. The components of the image recording layer can also be contained outside the microcapsules. As the image recording layer containing the microcapsules, it is a preferable embodiment that the hydrophobic component is encapsulated in the microcapsules and the hydrophilic component is contained outside the microcapsules.

The microgel (crosslinked polymer particles) can contain a part of the constituents of the image recording layer in at least one of the inside and the surface thereof. In particular, an embodiment in which a reactive microgel is formed by having a radically polymerizable group on the surface thereof is preferable from the viewpoint of image formation sensitivity and printing resistance.

A known method can be used for microencapsulating or microgelling the constituents of the image recording layer.
The average particle size of the microcapsules and microgels is preferably 0.01 to 3.0 μm, more preferably 0.05 to 2.0 μm, and particularly preferably 0.10 to 1.0 μm. Good resolution and stability over time can be obtained within this range.

As the polymer particles, polymer particles containing a monomer unit derived from a styrene compound and / or a monomer unit derived from a (meth) acrylonitrile compound are preferable from the viewpoint of contributing to on-machine developability. Further, polymer particles further containing a monomer unit derived from a poly (ethylene glycol) alkyl ether methacrylate compound are preferable.

The polymer particles may be used alone or in combination of two or more.
The content of the polymer particles is preferably 5 to 90% by mass, more preferably 5 to 80% by mass, still more preferably 10 to 75% by mass, based on the total solid content of the image recording layer.

According to another aspect, the image recording layer preferably contains a polymerization initiator, an infrared absorber, and a polymerizable compound.

<Polymer initiator>
A polymerization initiator is a compound that generates a polymerization initiator such as a radical or a cation by energy of light, heat, or both, and is a known thermal polymerization initiator, a compound having a bond having a small bond dissociation energy, and a photopolymerization initiator. It can be appropriately selected and used from the above.
As the polymerization initiator, an infrared photosensitive polymerization initiator is preferable. Further, as the polymerization initiator, a radical polymerization initiator is preferable.
Examples of the radical polymerization initiator include organic halides, carbonyl compounds, azo compounds, organic peroxides, metallocene compounds, azide compounds, hexaarylbiimidazole compounds, disulfone compounds, oxime ester compounds, and onium salt compounds. Be done.

As the organic halide, for example, the compounds described in paragraphs 0022 to 0023 of JP-A-2008-195018 are preferable.
As the carbonyl compound, for example, the compound described in paragraph 0024 of JP-A-2008-195018 is preferable.
Examples of the azo compound include the azo compounds described in JP-A-8-108621.
As the organic peroxide, for example, the compound described in paragraph 0025 of JP-A-2008-195018 is preferable.
As the metallocene compound, for example, the compound described in paragraph 0026 of JP-A-2008-195018 is preferable.
Examples of the azide compound include compounds such as 2,6-bis (4-azidobenzylidene) -4-methylcyclohexanone.
As the hexaarylbiimidazole compound, for example, the compound described in paragraph 0027 of JP-A-2008-195018 is preferable.
Examples of the disulfone compound include the compounds described in JP-A-61-166544 and JP-A-2002-328465.
As the oxime ester compound, for example, the compounds described in paragraphs 0028 to 0030 of JP-A-2008-195018 are preferable.

Among the polymerization initiators, more preferable ones include onium salts such as iodonium salt, sulfonium salt and azinium salt. Iodonium and sulfonium salts are particularly preferred. Specific examples of the iodonium salt and the sulfonium salt are shown below, but the present invention is not limited thereto.

As an example of the iodonium salt, a diphenyl iodonium salt is preferable, and in particular, a diphenyl iodonium salt having an electron donating group as a substituent, for example, a diphenyl iodonium salt substituted with an alkyl group or an alkoxyl group is preferable, and an asymmetric diphenyl iodonium salt is preferable. preferable. Specific examples include diphenyliodonium = hexafluorophosphate, 4-methoxyphenyl-4- (2-methylpropyl) phenyliodonium = hexafluorophosphate, 4- (2-methylpropyl) phenyl-p-tolyliodonium = hexa. Fluorophosphate, 4-hexyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, 4-hexyloxyphenyl-2,4-diethoxyphenyliodonium = tetrafluoroborate, 4-octyloxy Phenyl-2,4,6-trimethoxyphenyliodonium = 1-perfluorobutanesulfonate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphart, bis (4-t-butylphenyl) ) Iodonium = hexafluorophosphart can be mentioned.

As an example of the sulfonium salt, a triarylsulfonium salt is preferable, and in particular, a triarylsulfonium salt having an electron-attracting group as a substituent, for example, a triarylsulfonium salt in which at least a part of the group on the aromatic ring is substituted with a halogen atom is preferable. , A triarylsulfonium salt having a total number of substitutions of halogen atoms on the aromatic ring of 4 or more is more preferable. Specific examples include triphenylsulfonium = hexafluorophosphate, triphenylsulfonium = benzoylformate, bis (4-chlorophenyl) phenylsulfonium = benzoylformate, and bis (4-chlorophenyl) -4-methylphenylsulfonium = tetrafluoro. Borat, Tris (4-chlorophenyl) Sulfonium = 3,5-bis (methoxycarbonyl) Benzene Sulfonium, Tris (4-chlorophenyl) Sulfonium = Hexafluorophosphate, Tris (2,4-dichlorophenyl) Sulfonium = Hexafluorophos Fert is mentioned.

As the polymerization initiator, the following five types of polymerization initiators can also be used. (I) Alkyl or arylate complex: It is considered that the carbon-heterobond is oxidatively cleaved to generate an active radical. Specific examples thereof include borate compounds. (Ii) Aminoacetic acid compound: It is considered that the CX bond on the carbon adjacent to nitrogen is broken by oxidation to generate an active radical. As X, a hydrogen atom, a carboxy group, a trimethylsilyl group or a benzyl group is preferable. Specific examples thereof include N-phenylglycines (may have a substituent on the phenyl group), N-phenyliminodiacetic acid (may have a substituent on the phenyl group) and the like. Will be. (Iii) Sulfur-containing compound: The above-mentioned aminoacetic acid compound in which the nitrogen atom is replaced with a sulfur atom can generate an active radical by the same action. Specific examples thereof include phenylthioacetic acid (which may have a substituent on the phenyl group) and the like. (Iv) Tin-containing compound: A compound in which the nitrogen atom of the above-mentioned aminoacetic acid compound is replaced with a tin atom can generate an active radical by the same action. (V) Sulfinates: Oxidation can generate active radicals. Specific examples thereof include arylsulfinic acid sodium and the like.

Of these five types of polymerization initiators, borate compounds are preferable. As the borate compound, a tetraarylborate compound or a monoalkyltriarylborate compound is preferable, and a tetraarylborate compound is more preferable from the viewpoint of compound stability.
As the counter cation contained in the borate compound, an alkali metal ion or a tetraalkylammonium ion is preferable, and a sodium ion, a potassium ion or a tetrabutylammonium ion is more preferable.

Specific examples of the borate compound include the following compounds. Here, X _c ⁺ represents a monovalent cation, and an alkali metal ion or a tetraalkylammonium ion is preferable, and an alkali metal ion or a tetrabutylammonium ion is more preferable. Bu represents an n-butyl group.

The polymerization initiator may be used alone or in combination of two or more.
The content of the polymerization initiator is preferably 0.01 to 50% by mass, more preferably 0.05 to 30% by mass, still more preferably 0.1 to 20% by mass, based on the total solid content of the image recording layer.

<Infrared absorber>
The infrared absorber has a function of being excited by infrared rays to transfer electrons and / or energy to a polymerization initiator or the like. It also has a function of converting absorbed infrared rays into heat. The infrared absorber preferably has maximum absorption in the wavelength range of 750 to 1,400 nm. Examples of the infrared absorber include dyes and pigments, and dyes are preferably used.

As the dye, a commercially available dye and a known dye described in a document such as "Dye Handbook" (edited by the Society of Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes. Can be mentioned.
Among the dyes, cyanine pigments, squarylium pigments, and pyrylium salts are preferable, cyanine pigments are more preferable, and indorenine cyanine pigments are particularly preferable.

Examples of the cyanine pigment include a cyanine pigment represented by the following formula (a).

In formula (a), X ¹ represents a hydrogen atom, a halogen atom, -N (R ⁹ ) (R ¹⁰ ), -X ² -L ¹ or a group shown below. Here, R ⁹ and R ¹⁰ may be the same or different, and independently represent an aromatic hydrocarbon group having 6 to 10 carbon atoms, an alkyl group having 1 to 8 carbon atoms, or a hydrogen atom, respectively. ⁹ and R ¹⁰ may be coupled to each other to form a ring. An aromatic hydrocarbon group having 6 to 10 carbon atoms or an alkyl group having 1 to 8 carbon atoms may have a substituent. Both R ⁹ and R ¹⁰ are preferably phenyl groups. X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms or a hydrocarbon group having 1 to 12 carbon atoms including a hetero atom. Here, the hetero atom represents N, S, O, a halogen atom, and Se. In the groups shown below, Xa ^- is synonymous with Za ^- described later, and Ra represents a hydrogen atom or a substituent selected from an alkyl group, an aryl group, a substituted or unsubstituted amino group and a halogen atom.

In formula (a), R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the viewpoint of storage stability of the image recording layer coating liquid, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and further, R ¹ and R ² are bonded to each other to form a 5-membered ring or a 5-membered ring. It is particularly preferable to form a 6-membered ring.

In the formula (a), Ar ¹ and Ar ² may be the same or different, and each represents an aromatic hydrocarbon group. The aromatic hydrocarbon group may have a substituent. Preferred aromatic hydrocarbon groups include benzene ring groups and naphthalene ring groups. In addition, preferred substituents include a hydrocarbon group having 12 or less carbon atoms, a halogen atom, and an alkoxy group having 12 or less carbon atoms. Y ¹ and Y ² may be the same or different, and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different, and each represents a hydrocarbon group having 20 or less carbon atoms. A hydrocarbon group having 20 or less carbon atoms may have a substituent. Preferred substituents include an alkoxy group having 12 or less carbon atoms, a carboxy group and a sulfo group. R5, R6, ^R7 and ^R8 may be the ^same or different and represent hydrogen atoms or hydrocarbon groups having ¹² or less carbon atoms, respectively. A hydrogen atom is preferable because of the availability of a raw material. Further, Za ⁻ represents a counter anion. However, if the cyanine dye represented by the formula (a) has an anionic substituent in its structure and charge neutralization is not required, Za ⁻ is not required. Za ⁻ is preferably halide ion, perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion, or sulfonic acid ion, and is preferably perchlorate ion or hexafluorophosphate ion, from the viewpoint of storage stability of the image recording layer coating liquid. , Or aryl sulfonate ions are more preferred.

In the cyanine dye represented by the formula (a), it is more preferable that X ¹ is a diphenylamino group. Further, it is more preferable that X ¹ is a diphenylamino group and Y ¹ and Y ² are both dimethylmethylene groups.

Specific examples of the cyanine dye include the compounds described in paragraphs 0017 to 0019 of JP-A-2001-133769, paragraphs 0016 to 0021 of JP-A-2002-0233360, and paragraphs 0012 to 0037 of JP-A-2002-040638. , Preferably the compounds described in paragraphs 0034 to 0041 of JP-A-2002-278057, paragraphs 0080-0086 of JP-A-2008-195018, and particularly preferably paragraphs 0035 to Japanese Patent Application Laid-Open No. 2007-90850. Examples thereof include the compounds described in 0043.
Further, the compounds described in paragraphs 0008 to 0009 of JP-A-5-5005 and paragraphs 0022 to 0025 of JP-A-2001-222101 can also be preferably used.
As the pigment, the compounds described in paragraphs 0072 to 0076 of JP-A-2008-195018 are preferable.

The infrared absorber may be used alone or in combination of two or more.
The content of the infrared absorber is preferably 0.05 to 30% by mass, more preferably 0.1 to 20% by mass, still more preferably 0.2 to 10% by mass, based on the total solid content of the image recording layer.

<Polymerizable compound>
The polymerizable compound may be, for example, a radically polymerizable compound or a cationically polymerizable compound, but is an addition polymerizable compound having at least one ethylenically unsaturated bond (ethylenically unsaturated compound). It is preferable to have. As the ethylenically unsaturated compound, a compound having at least one terminal ethylenically unsaturated bond is preferable, and a compound having two or more terminal ethylenically unsaturated bonds is more preferable. The polymerizable compound can have a chemical form such as, for example, a monomer, a prepolymer, that is, a dimer, a trimer or an oligomer, or a mixture thereof.

Examples of the monomer include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid), esters thereof, and amides. Preferably, esters of unsaturated carboxylic acid and polyhydric alcohol compound, and amides of unsaturated carboxylic acid and polyhydric amine compound are used. Further, an addition reaction product of unsaturated carboxylic acid esters or amides having a nucleophilic substituent such as a hydroxy group, an amino group or a mercapto group with monofunctional or polyfunctional isocyanates or epoxys, and monofunctional or A dehydration condensation reaction product with a polyfunctional carboxylic acid is also preferably used. Further, an addition reaction product of unsaturated carboxylic acid esters or amides having a polyelectron substituent such as an isocyanate group or an epoxy group with monofunctional or polyfunctional alcohols, amines and thiols, and a halogen atom, Substitutable reactions of unsaturated carboxylic acid esters or amides having a desorbing substituent such as a tosyloxy group with monofunctional or polyfunctional alcohols, amines and thiols are also suitable. Further, as another example, a compound group in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene, vinyl ether or the like can also be used. These compounds are described in JP-A-2006-508380, JP-A-2002-287344, JP-A-2008-256850, JP-A-2001-342222, JP-A-9-179296, JP-A-9-179297. JP, JP-A-9-179298, JP-A-2004-294935, JP-A-2006-243493, JP-A-2002-275129, JP-A-2003-64130, JP-A-2003-280187, It is described in JP-A No. 10-333321.

Specific examples of the monomer of the ester of the polyhydric alcohol compound and the unsaturated carboxylic acid include ethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, and propylene glycol diacrylate, as acrylic acid esters. Examples thereof include trimethylolpropane triacrylate, hexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol tetraacrylate, sorbitol triacrylate, isocyanuric acid ethylene oxide (EO) modified triacrylate, and polyester acrylate oligomer. Methacrylic acid esters include tetramethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, pentaerythritol trimethacrylate, bis [p- (3-methacryloxy-2-hydroxypropoxy) phenyl]. Examples thereof include dimethylmethane and bis [p- (methacrylicoxyethoxy) phenyl] dimethylmethane. Specific examples of the amide monomer of the polyvalent amine compound and the unsaturated carboxylic acid include methylenebisacrylamide, methylenebismethacrylamide, 1,6-hexamethylenebisacrylamide, and 1,6-hexamethylenebismethacrylate. Examples thereof include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, and xylylenebismethacrylamide.

Further, a urethane-based addition-polymerizable compound produced by using an addition reaction of isocyanate and a hydroxy group is also suitable, and specific examples thereof include, for example, one molecule described in Japanese Patent Publication No. 48-41708. Vinyl containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxy group represented by the following formula (M) to a polyisocyanate compound having two or more isocyanate groups. Examples include urethane compounds.
CH ₂ = C (RM4) COOCH ₂ CH ( ^RM5 ) OH ( ^M )
In formula ( ^M ), RM4 and ^RM5 each independently represent a hydrogen atom or a methyl group.

Further, urethane acrylates described in JP-A-51-37193, JP-A-2-32293, JP-A-2-16765, JP-A-2003-344997, JP-A-2006-65210, and Japanese Patent Publication No. The ethylene described in Japanese Patent Application Laid-Open No. 58-49860, Japanese Patent Publication No. 56-17654, Japanese Patent Publication No. 62-39417, Japanese Patent Application Laid-Open No. 62-39418, Japanese Patent Application Laid-Open No. 2000-250211, and Japanese Patent Application Laid-Open No. 2007-94138. Urethane compounds having an oxide-based skeleton, urethane compounds having a hydrophilic group described in US Pat. No. 7,153,632, JP-A-8-505598, JP-A-2007-293221, JP-A-2007-293223. Kind is also suitable.

The details of the structure of the polymerizable compound, whether it is used alone or in combination, and the method of use such as the amount of addition can be arbitrarily set in consideration of the final use of the lithographic printing plate original plate.
The content of the polymerizable compound is preferably 1 to 50% by mass, more preferably 3 to 30% by mass, still more preferably 5 to 20% by mass, based on the total solid content of the image recording layer.

The image recording layer can contain a binder polymer, a chain transfer agent, a small molecule hydrophilic compound, a greasing agent, and other components.

<Binder polymer>
As the binder polymer, a polymer having a film property is preferable, and (meth) acrylic resin, polyvinyl acetal resin, polyurethane resin and the like are preferably mentioned.

A binder polymer used for the image recording layer of the machine-developed lithographic printing plate original plate (hereinafter, also referred to as a binder polymer for machine-developing) will be described in detail.
As the binder polymer for on-machine development, a binder polymer having an alkylene oxide chain is preferable. The binder polymer having an alkylene oxide chain may have a poly (alkylene oxide) moiety in the main chain or the side chain. Further, it may be a graft polymer having poly (alkylene oxide) in the side chain, or a block copolymer having a block composed of poly (alkylene oxide) -containing repeating units and a block composed of (alkylene oxide) -free repeating units.
When the main chain has a poly (alkylene oxide) moiety, a polyurethane resin is preferable. When the polymer of the main chain has a poly (alkylene oxide) moiety in the side chain, the polymer of the main chain is (meth) acrylic resin, polyvinyl acetal resin, polyurethane resin, polyurea resin, polyimide resin, polyamide resin, epoxy resin, polystyrene resin, novolak type. Examples thereof include phenol resin, polyester resin, synthetic rubber and natural rubber, and (meth) acrylic resin is particularly preferable.

As the alkylene oxide, an alkylene oxide having 2 to 6 carbon atoms is preferable, and ethylene oxide or propylene oxide is particularly preferable.
The number of repetitions of the alkylene oxide in the poly (alkylene oxide) moiety is preferably 2 to 120, more preferably 2 to 70, and even more preferably 2 to 50.
When the number of repetitions of the alkylene oxide is 120 or less, both the printing resistance due to abrasion and the printing resistance due to ink acceptability do not decrease, which is preferable.

The poly (alkylene oxide) moiety is preferably contained as a side chain of the binder polymer in a structure represented by the following formula (AO), and is represented by the following formula (AO) as a side chain of a (meth) acrylic resin. It is more preferable that it is contained in the structure to be used.

In formula (AO), y represents 2 to 120, R ₁ represents a hydrogen atom or an alkyl group, and R ₂ represents a hydrogen atom or a monovalent organic group.
As the monovalent organic group, an alkyl group having 1 to 6 carbon atoms is preferable. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n- Examples thereof include a hexyl group, an isohexyl group, a 1,1-dimethylbutyl group, a 2,2-dimethylbutyl group, a cyclopentyl group and a cyclohexyl group.
In the formula (AO), y is preferably 2 to 70, more preferably 2 to 50. R ₁ is preferably a hydrogen atom or a methyl group, and a hydrogen atom is particularly preferable. _R2 is particularly preferably a hydrogen atom or a methyl group.

The binder polymer may have crosslinkability in order to improve the film strength of the image portion. In order to impart crosslinkability to the polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may be introduced by copolymerization or by a polymer reaction.
Examples of polymers having an ethylenically unsaturated bond in the main chain of the molecule include poly-1,4-butadiene, poly-1,4-isoprene and the like.
An example of a polymer having an ethylenically unsaturated bond in the side chain of a molecule is a polymer of an ester or amide of acrylic acid or methacrylic acid in which the residue of the ester or amide (-COOR or -R of -CONHR) A polymer having an ethylenically unsaturated bond can be mentioned.

Examples of residues having an ethylenically unsaturated bond (R above) are-(CH ₂ ) _n CR ^1A = CR ^{2AR 3A} ,-(CH ₂ O) _n CH ₂ CR ^1A = CR ^2A R ^3A ,-. (CH ₂ CH ₂ O) _n CH ₂ CR ^1A = CR ^2A R ^3A ,-(CH ₂ ) _n NH-CO-O-CH ₂ CR ^1A = CR ^{2AR 3A} ,-(CH ₂ ) _n -O-CO -CR ^1A = CR ^2A R ^3A and-(CH ₂ CH ₂ O) ₂ -X ^A (In the formula, ^RA1 to ^RA3 are independent hydrogen atoms, halogen atoms, and alkyl groups having 1 to 20 carbon atoms, respectively. It represents an aryl group, an alkoxy group or an aryloxy group, and ^RA1 and ^RA2 or ^RA3 may be bonded to each other to form a ring. N represents an integer of 1 to 10. X ^A represents a di. Represents a cyclopentadienyl residue.).

Specific examples of ester residues include -CH ₂ CH = CH ₂ , -CH ₂ CH ₂ O-CH ₂ CH = CH ₂ , -CH ₂ C (CH ₃ ) = CH ₂ , -CH ₂ CH = CH-. C ₆ H ₅ , -CH ₂ CH ₂ OCOCH = CH-C ₆ H ₅ , -CH ₂ CH ₂ -NHCOO-CH ₂ CH = CH ₂ and -CH ₂ CH ₂ O-X (in the formula, X is dicyclo Represents a pentadienyl residue.).
Specific examples of the amide residue include -CH ₂ CH = CH ₂ , -CH ₂ CH ₂ -Y (in the formula, Y represents a cyclohexene residue) and -CH ₂ CH ₂ -OCO-CH = CH ₂ . Can be mentioned.

A crosslinkable binder polymer has, for example, a free radical (a polymerization initiation radical or a growth radical in the polymerization process of a polymerizable compound) added to the crosslinkable functional group to directly or chain the polymerization of the polymerizable compound between the polymers. Through addition polymerization, crosslinks are formed between the polymer molecules and the polymer molecules are cured. Alternatively, atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to functional cross-linking groups) are abstracted by free radicals to generate polymer radicals that bond to each other, resulting in cross-linking between the polymer molecules. Formed and cured.

The content of crosslinkable groups in the binder polymer (content of unsaturated double bonds that can be radically polymerized by iodine titration) is 0.1 per 1 g of the binder polymer from the viewpoint of good sensitivity and good storage stability. It is preferably ~ 10.0 mmol, more preferably 1.0 to 7.0 mmol, still more preferably 2.0 to 5.5 mmol.

Specific examples 1 to 11 of the binder polymer are shown below, but the present invention is not limited thereto. In the following exemplified compounds, the numerical value written together with each repeating unit (the numerical value written together with the main chain repeating unit) represents the molar percentage of the repeating unit. The numerical value written together with the repeating unit of the side chain indicates the number of repetitions at the repeating site. Further, Me represents a methyl group, Et represents an ethyl group, and Ph represents a phenyl group.

As for the molecular weight of the binder polymer, the weight average molecular weight (Mw) is 2,000 or more, preferably 5,000 or more, and more preferably 10,000 to 300,000 in terms of polystyrene by the GPC method.

If necessary, hydrophilic polymers such as polyacrylic acid and polyvinyl alcohol described in JP-A-2008-195018 can be used in combination. In addition, a lipophilic polymer and a hydrophilic polymer can be used in combination.

The binder polymer may be used alone or in combination of two or more.
The content of the binder polymer is preferably 1 to 90% by mass, more preferably 5 to 80% by mass, based on the total solid content of the image recording layer.

<Chain transfer agent>
The chain transfer agent contributes to the improvement of printing durability in a lithographic printing plate produced from a lithographic printing plate original plate.
As the chain transfer agent, a thiol compound is preferable, a thiol having 7 or more carbon atoms is more preferable from the viewpoint of boiling point (difficulty in volatilization), and a compound having a mercapto group on the aromatic ring (aromatic thiol compound) is further preferable. The thiol compound is preferably a monofunctional thiol compound.

Specific examples of the chain transfer agent include the following compounds.

The chain transfer agent may be used alone or in combination of two or more.
The content of the chain transfer agent is preferably 0.01 to 50% by mass, more preferably 0.05 to 40% by mass, still more preferably 0.1 to 30% by mass, based on the total solid content of the image recording layer.

<Small molecule hydrophilic compound>
The low molecular weight hydrophilic compound contributes to the improvement of the on-machine developability of the lithographic printing plate original plate without deteriorating the printing durability of the lithographic printing plate original plate produced from the lithographic printing plate original plate. The low molecular weight hydrophilic compound is preferably a compound having a molecular weight of less than 1,000, more preferably a compound having a molecular weight of less than 800, and further preferably a compound having a molecular weight of less than 500.
Examples of the low molecular weight hydrophilic compound include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol, ethers or ester derivatives thereof, and glycerin as water-soluble organic compounds. Polyols such as pentaerythritol and tris (2-hydroxyethyl) isocyanurate, organic amines such as triethanolamine, diethanolamine and monoethanolamine and salts thereof, organic sulfates such as alkylsulfonic acid, toluenesulfonic acid and benzenesulfonic acid. Acids and salts thereof, organic sulfamic acids such as alkylsulfamic acid and salts thereof, organic sulfates such as alkylsulfuric acid and alkyl ether sulfuric acid and salts thereof, organic phosphonic acids such as phenylphosphonic acid and salts thereof, tartaric acid, oxalic acid, quench Examples thereof include organic carboxylic acids such as acids, malic acid, lactic acid, gluconic acid and amino acids, salts thereof, betaines and the like.

The low molecular weight hydrophilic compound is preferably at least one selected from polyols, organic sulfates, organic sulfonates and betaines.

Specific examples of the organic sulfonates include alkyl sulfonates such as sodium n-butyl sulfonate, sodium n-hexyl sulfonate, sodium 2-ethylhexyl sulfonate, sodium cyclohexyl sulfonate, sodium n-octyl sulfonate; 5 , 8,11-Trioxapentadecane-1-sodium sulfonate, 5,8,11-trioxaheptadecane-1-sodium sulfonate, 13-ethyl-5,8,11-trioxaheptadecane-1-sulfon Alkyl sulfonates containing ethylene oxide chains such as sodium acid, 5,8,11,14-sodium tetraoxatetracosan-1-sulfonate; sodium benzenesulfonate, sodium p-toluenesulfonate, p-hydroxybenzenesulfonic acid Sodium, sodium p-styrene sulfonate, dimethyl-5-sulfonate sodium isophthalate, sodium 1-naphthyl sulfonate, sodium 4-hydroxynaphthyl sulfonate, disodium 1,5-naphthalenedi sulfonate, 1,3,6- Examples thereof include aryl sulfonates such as trisodium naphthalenetrisulfonate, and compounds described in paragraphs 0026 to 0031 of JP-A-2007-276454 and paragraphs 0020-0047 of JP-A-2009-154525. The salt may be a potassium salt or a lithium salt.

Examples of the organic sulfates include sulfates of alkyl, alkenyl, alkynyl, aryl or heterocyclic monoether of polyethylene oxide. The number of ethylene oxide units is preferably 1 to 4, and the salt is preferably a sodium salt, a potassium salt or a lithium salt. Specific examples thereof include the compounds described in paragraphs 0034 to 0038 of JP-A-2007-276454.

As betaines, compounds having 1 to 5 carbon atoms of the hydrocarbon substituent on the nitrogen atom are preferable, and specific examples thereof include trimethylammonium acetate, dimethylpropylammonium acetate, and 3-hydroxy-4-trimethylammoni. Obutyrate, 4- (1-pyridinio) butyrate, 1-hydroxyethyl-1-imidazolio acetate, trimethylammonium methanesulfonate, dimethylpropylammonium methanesulfonate, 3-trimethylammonio-1-propanesulfonate, 3 -(1-Pyridinio) -1-Propyl sulfonate and the like can be mentioned.

Since the low-molecular-weight hydrophilic compound has a small structure of the hydrophobic part and has almost no surface-active action, dampening water permeates the exposed part (image part) of the image recording layer and reduces the hydrophobicity and film strength of the image part. It is possible to maintain good ink acceptability and printing durability of the image recording layer.

The small molecule hydrophilic compound may be used alone or in combination of two or more.
The content of the small molecule hydrophilic compound is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, still more preferably 2 to 10% by mass, based on the total solid content of the image recording layer.

<Fat sensitive agent>
The oil-sensitive agent contributes to the improvement of the inking property (hereinafter, also simply referred to as “meat-setting property”) of the ink in the lithographic printing plate produced from the lithographic printing plate original plate. Examples of the fat sensitive agent include phosphonium compounds, nitrogen-containing small molecule compounds, and ammonium group-containing polymers. In particular, when the lithographic printing plate precursor contains an inorganic layered compound in the protective layer, these compounds function as a surface coating agent for the inorganic layered compound, and have a function of suppressing deterioration of inking property during printing due to the inorganic layered compound. Have.
As the fat-sensing agent, it is preferable to use a phosphonium compound, a nitrogen-containing low molecular weight compound, and an ammonium group-containing polymer in combination, and the phosphonium compound, a quaternary ammonium salt, and an ammonium group-containing polymer are used in combination. Is more preferable.

Examples of the phosphonium compound include the phosphonium compounds described in JP-A-2006-297907 and JP-A-2007-50660. Specific examples include tetrabutylphosphonium iodide, butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide, 1,4-bis (triphenylphosphonio) butane-di (hexafluorophosphate), and 1,7-bis (tri). Phenylphosphonio) heptane-sulfate, 1,9-bis (triphenylphosphonio) nonan-naphthalen-2,7-disulfonate and the like can be mentioned.

Examples of the nitrogen-containing small molecule compound include amine salts and quaternary ammonium salts. Further, imidazolinium salts, benzoimidazolinium salts, pyridinium salts, quinolinium salts and the like can also be mentioned. Of these, quaternary ammonium salts and pyridinium salts are preferable. Specific examples include tetramethylammonium = hexafluorophosphate, tetrabutylammonium = hexafluorophosphate, dodecyltrimethylammonium = p-toluenesulfonate, benzyltriethylammonium = hexafluorophosphate, and benzyldimethyloctylammonium = hexafluorophos. Examples thereof include fert, benzyldimethyldodecylammonium = hexafluorophosphate, compounds described in paragraphs 0021 to 0037 of JP-A-2008-284858 and paragraphs 0030 to 0057 of JP-A-2009-90645.

The ammonium group-containing polymer may have an ammonium group in its structure, and a polymer containing 5 to 80 mol% of (meth) acrylate having an ammonium group in the side chain as a copolymerization component is preferable. Specific examples thereof include the polymers described in paragraphs 809-0105 of JP-A-2009-208458.

The ammonium group-containing polymer preferably has a reduction specific viscosity (unit: ml / g) in the range of 5 to 120, which is obtained according to the measurement method described in JP-A-2009-208458, and is in the range of 10 to 110. Those in the range of 15 to 100 are particularly preferable. When the reduced specific viscosity is converted into a weight average molecular weight (Mw), it is preferably 10,000 to 150,000, more preferably 17,000 to 140,000, and particularly preferably 20,000 to 130,000.

Specific examples of the ammonium group-containing polymer are shown below.
(1) 2- (trimethylammonio) ethyl methacrylate = p-toluenesulfonate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 10/90, Mw 45,000)
(2) 2- (trimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80, Mw 60,000)
(3) 2- (Ethyldimethylammonio) Ethylmethacrylate = p-toluenesulfonate / hexylmethacrylate copolymer (molar ratio 30/70, Mw45,000)
(4) 2- (trimethylammonio) ethyl methacrylate = hexafluorophosphate / 2-ethylhexyl methacrylate copolymer (molar ratio 20/80, Mw 60,000)
(5) 2- (trimethylammonio) ethyl methacrylate = methyl sulfate / hexyl methacrylate copolymer (molar ratio 40/60, Mw 7,000,000)
(6) 2- (Butyldimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 25/75, Mw 65,000)
(7) 2- (Butyldimethylammonio) ethyl acrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80, Mw 65,000)
(8) 2- (Butyldimethylammonio) ethyl methacrylate = 13-ethyl-5,8,11-trioxa-1-heptadecanesulfonate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80) , Mw 75,000)
(9) 2- (Butyldimethylammonio) Ethyl Methacrylate = Hexafluorophosphate / 3,6-dioxaheptyl methacrylate / 2-Hydroxy-3-methacloyloxypropyl methacrylate copolymer (molar ratio 15/80/5) , Mw 65,000)

The content of the oil-sensitive agent is preferably 0.01 to 30% by mass, more preferably 0.1 to 15% by mass, still more preferably 1 to 10% by mass, based on the total solid content of the image recording layer.

<Other ingredients>
The image recording layer can contain a surfactant, a polymerization inhibitor, a higher fatty acid derivative, a plasticizer, inorganic particles, an inorganic layered compound and the like as other components. Specifically, each component described in paragraphs 0114 to 0159 of JP-A-2008-284817 can be used.

According to one form of the image recording layer, the image recording layer contains an infrared absorber, a polymerizable compound, a polymerization initiator, and at least one of a binder polymer and polymer particles. The image recording layer preferably further contains a chain transfer agent. According to another form of the image recording layer, the image recording layer contains an infrared absorber, heat-sealing particles, and a binder polymer.

<Formation of image recording layer>
For the image recording layer, for example, as described in paragraphs 0142 to 0143 of Japanese Patent Application Laid-Open No. 2008-195018, necessary above-mentioned components are appropriately dispersed or dissolved in a known solvent to prepare a coating liquid, and the coating liquid is prepared. It can be formed by applying it to a support by a known method such as applying a bar coater and drying it. The coating amount (solid content) of the image recording layer after coating and drying varies depending on the application, but from the viewpoint of obtaining good sensitivity and good film characteristics of the image recording layer, it is about 0.3 to 3.0 g / m ² . Is preferable.

[Layer containing a compound having support adsorptivity]
A layer containing a compound having a support-adsorbing property, which constitutes an on-machine development type lithographic printing plate original plate, will be described.

The layer (hereinafter, also referred to as a specific compound-containing layer) containing a compound having a support adsorptive property (hereinafter, also referred to as a specific compound) contains a compound having a support adsorptive property. The specific compound-containing layer is selected from printing ink and dampening water on a printing machine from the viewpoint of effectively exhibiting edge stain prevention without deteriorating characteristics such as image formability and on-machine developability of edges. It is preferable that the layer has a property of being removed by at least one. The specific compound-containing layer is more preferably water-soluble in order to easily elute the specific compound.

The specific compound-containing layer includes not only a form in which the specific compound is a continuous layer containing the specific compound, but also a form in which the specific compound is discontinuously scattered in an island shape.

The specific compound-containing layer may be present on the image recording layer. That is, it suffices if it exists at a position farther from the support than the image recording layer. For example, it is preferable that it is in contact with and above the image recording layer.

<Compounds with support adsorption>
One of the characteristics of the compound having the support adsorptivity (specific compound) contained in the specific compound-containing layer is that the compound has the support adsorbability. Here, the "support adsorptivity" means the adsorptivity of the aluminum support to the anodic oxide film. The presence or absence of adsorptivity to the anodic oxide film can be easily determined by the following method.
That is, a solution in which the test compound is dissolved in an easily soluble solvent (for example, water) is prepared. This solution is applied onto an aluminum support having an anodic oxide film so that the applied amount after drying is 30 mg / m ² , and dried. Next, the aluminum support coated with the test compound is washed and dried 5 times using the above-mentioned easily soluble solvent, and then the residual amount of the test compound not removed by washing is measured. The residual amount may be measured by directly quantifying the residual test compound amount, or by quantifying the test compound amount dissolved in the washing solution and using this value to calculate the residual test compound amount. The quantification of the test compound can be carried out, for example, by fluorescent X-ray measurement, reflection spectroscopic absorbance measurement, or the like.
If the residual amount is 1 mg / m ² or more, the test compound is determined to have support adsorptivity.

Since the specific compound has a support adsorptive property, it is preferable that the specific compound has a group that exhibits adsorptivity to the anodic oxide film of the aluminum support. Examples of the group exhibiting adsorptivity to the anodic oxide film of the aluminum support include a chemical bond (for example, a hydroxyl group) with a substance (for example, metal, metal oxide) or a functional group (for example, a hydroxyl group) existing on the surface of the anodic oxide film. For example, functional groups capable of forming ionic bonds, hydrogen bonds, coordination bonds) can be mentioned. Such functional groups are well known in the art.
Among such functional groups, an acid group is preferable. The acid group preferably has an acid dissociation constant (pKa) of 7 or less. Examples of acid groups include phenolic hydroxyl groups, carboxyl groups, -SO ₃ H, -OSO ₃ H, -PO ₃ H ₂ , -OPO ₃ H ₂ , -CONHSO _2- , -SO ₂ NHSO _2- , -COCH. ₂ COCH ₃ and the like can be mentioned. In particular, -OPO ₃ H ₂ and -PO ₃ H ₂ are preferable. The acid group may form a salt. Examples of the salt formed by the acid group include an alkali metal salt, an alkaline earth metal salt, and an ammonium salt.

The molecular weight of the specific compound is preferably 1,000 or less. When the molecular weight is 1,000 or less, the specific compound easily moves from the specific compound-containing layer to the surface of the anodic oxide film at the edge of the lithographic printing plate original plate during on-machine development, and an excellent edge stain prevention effect can be obtained. it is conceivable that. The molecular weight is preferably 50 to 1,000, more preferably 50 to 800, and even more preferably 50 to 600.

Oxyacid can be used as the specific compound. Oxyacid refers to a compound in which a hydroxyl group (-OH) and an oxo group (= O) are bonded to the same atom, and the hydroxyl group gives an acidic proton. Oxyacids may be used in the form of salts. Examples of the salt include alkali metal salts, alkaline earth metal salts, ammonium salts and the like.

As the specific compound, a compound represented by the following formula 1 can also be used.

In formula 1, n represents an integer of 2 to 10, and R1, R2, and R3 independently represent a hydrogen atom, an alkali metal salt, an alkaline earth metal salt, an ammonium salt, an alkyl group, or an alkylene oxide group. ..

The alkyl group in the formula 1 is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and further preferably an alkyl group having 1 to 3 carbon atoms. The alkylene oxide group in the formula 1 is preferably an alkylene oxide group having 1 to 10 alkylene oxide units having 2 or 3 carbon atoms, and more preferably an alkylene oxide group having 1 to 5 alkylene oxide units having 2 or 3 carbon atoms. , An alkylene oxide group having 1 to 3 alkylene oxide units having 2 or 3 carbon atoms is more preferable.

Specific examples of the specific compound include phosphoric acid, polyphosphoric acid, metaphosphate, ammonium primary phosphate, ammonium secondary phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, potassium primary phosphate, and secondary phosphorus. Potassium acid, sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, phosphinic acid, ethylphosphonic acid, propylphosphonic acid, i-propylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, dodecylphosphonic acid, octadecylphosphon Alkylphosphonic acid monoalkyl esters such as acids, 2-hydroxyethylphosphonic acid and their sodium or potassium salts, methyl methylphosphonate, methyl ethylphosphonate, 2-hydroxyethylphosphonate and their sodium or potassium salts, Alkylene diphosphonic acids such as methylene diphosphonic acid and ethylene diphosphonic acid and their sodium or potassium salts, hydroxyethylidene diphosphonic acid, polyvinylphosphonic acid, p-toluenesulfonic acid, sodium p-toluenesulfonate, sulfophthalic acid, Examples include citrate.

As the specific compound, phosphoric acid, polyphosphoric acid, phosphoric acid, phosphinic acid and salts thereof are particularly preferable from the viewpoint of adsorptivity to the anodic oxide film.

The specific compound may be used alone or in combination of two or more.
The content of the specific compound in the specific compound-containing layer is preferably 20 to 150 mg / m ² , more preferably 30 to 100 mg / m ² , and even more preferably 50 to 100 mg / m ² .
One of the features of the lithographic printing plate original plate of the present invention is that the content of the specific compound is substantially the same in the plane of the specific compound-containing layer. Here, "the content of the specific compound is substantially the same in the plane of the specific compound-containing layer" means that the specific compound is present almost uniformly in the plane of the specific compound-containing layer, and the lithographic printing plate original plate. It means that there is no substantial difference in the content of the specific compound between the central portion and the edge portion. That is, it means that there is no difference in content other than the difference in the content of the specific compound in the plane of the specific compound-containing layer that can normally occur when the specific compound-containing layer is applied.
Therefore, in the present invention, the specific compound is intentionally applied only to the end portion of the lithographic printing plate original plate so that the content of the specific compound at the end portion is larger than the content of the specific compound in the region other than the end portion. Is different from forming.

The specific compound-containing layer preferably contains a surfactant. The surfactant has the effect of adjusting the surface tension of the specific compound-containing layer coating liquid and giving a uniform coating surface shape.
Examples of the surfactant include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. Anionic surfactants and nonionic surfactants are preferable. Examples of the anionic surfactant include compounds described as anionic surfactants in paragraph No. [0022] of JP-A-2014-104631. Examples of the nonionic surfactant include compounds described as nonionic surfactants in paragraph number [0031] of JP-A-2014-104631. If necessary, two or more kinds of surfactants may be mixed and used.
The content of the surfactant in the specific compound-containing layer is preferably 5 to 50 mg / m ² , more preferably 5 to 20 mg / m ² , and even more preferably 8 to 15 mg / m ² .

The specific compound-containing layer preferably contains a water-soluble polymer. The water-soluble polymer functions as a binder for the specific compound-containing layer. In addition, the water-soluble polymer has the effect of dissolving the specific compound by the action of dampening water or the like during on-machine development.
As the water-soluble polymer, a water-soluble polymer used for a protective layer (sometimes referred to as an overcoat layer) of a lithographic printing plate precursor can be preferably used. Specific examples thereof include polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, water-soluble cellulose derivatives, poly (meth) acrylonitrile, and the like. If necessary, the water-soluble polymer may be used as a mixture of two or more kinds.
The content of the water-soluble polymer in the specific compound-containing layer is preferably 30 to 300 mg / m ² , more preferably 30 to 150 mg / m ² , and even more preferably 50 to 120 mg / m ² .

<Formation of specific compound-containing layer>
The specific compound-containing layer can be formed, for example, by appropriately dissolving each necessary component in a solvent such as water to prepare a coating liquid, applying the coating liquid on an image recording layer by a known method, and drying the coating liquid. can.
The specific compound-containing layer can be integrated with the protective layer and formed on the image recording layer as one layer. Such a form will be described in the protective layer described later.

The on-machine development type lithographic printing plate original plate according to the present invention may have an undercoat layer (sometimes referred to as an intermediate layer) between the image recording layer and the support.

[Undercoat layer]
The undercoat layer strengthens the adhesion between the support and the image recording layer in the exposed area, and makes it easy for the image recording layer to peel off from the support in the unexposed area, so that the developability is not impaired. Contributes to improving. Further, in the case of infrared laser exposure, the undercoat layer functions as a heat insulating layer, which also has an effect of preventing heat generated by the exposure from diffusing to the support and reducing the sensitivity.

Examples of the compound used for the undercoat layer include polymers having an adsorptive group and a hydrophilic group that can be adsorbed on the surface of the support. In order to improve the adhesion to the image recording layer, a polymer having an adsorptive group and a hydrophilic group and further having a crosslinkable group is preferable. The compound used for the undercoat layer may be a small molecule compound or a polymer. As the compound used for the undercoat layer, two or more kinds may be mixed and used as needed.

When the compound used for the undercoat layer is a polymer, a copolymer of a monomer having an adsorptive group, a monomer having a hydrophilic group and a monomer having a crosslinkable group is preferable.
Adsorbable groups that can be adsorbed on the surface of the support include phenolic hydroxy group, carboxy group, -PO ₃ H ₂ , -OPO ₃ H ₂ , -CONHSO _2- , -SO ₂ NHSO _2- , -COCH ₂ COCH ₃ Is preferable. As the hydrophilic group, a sulfo group or a salt thereof, or a salt of a carboxy group is preferable. As the crosslinkable group, an acrylic group, a methacrylic group, an acrylamide group, a methacrylicamide group, an allyl group and the like are preferable.
The polymer may have a polar substituent of the polymer and a crosslinkable group introduced by salt formation with a substituent having a countercharge with the polar substituent and a compound having an ethylenically unsaturated bond. A monomer other than the above, preferably a hydrophilic monomer may be further copolymerized.

Specifically, a silane coupling agent having an addition-polymerizable ethylenic double bond reactive group described in JP-A No. 10-282679, and an ethylenic substance described in JP-A-2-304441. A phosphorus compound having a double bond reactive group is preferably mentioned. Crosslinkable groups (preferably ethylenically unsaturated bonding groups) and supports described in JP-A-2005-238816, JP-A-2005-125479, JP-A-2006-239867, and JP-A-2006-215263. Low molecular weight or high molecular weight compounds having functional and hydrophilic groups that interact with the surface are also preferably used.
More preferable examples thereof include polymer polymers having an adsorptive group, a hydrophilic group and a crosslinkable group that can be adsorbed on the surface of the support described in JP-A-2005-125479 and JP-A-2006-188038.

The content of the ethylenically unsaturated bond group in the polymer used for the undercoat layer is preferably 0.1 to 10.0 mmol, more preferably 0.2 to 5.5 mmol per 1 g of the polymer.
The mass average molecular weight (Mw) of the polymer used for the undercoat layer is preferably 5,000 or more, more preferably 10,000 to 300,000.

In addition to the above-mentioned compound for the undercoat layer, the undercoat layer includes a chelating agent, a secondary or tertiary amine, a polymerization inhibitor, an amino group or a functional group having a polymerization prohibitive ability and a support surface in order to prevent stains over time. Compounds with groups that interact with (eg, 1,4-diazabicyclo [2.2.2] octane (DABCO), 2,3,5,6-tetrahydroxy-p-quinone, chloranyl, sulfophthalic acid, hydroxy Ethylethylenediamine triacetic acid, dihydroxyethylethylenediaminediacetic acid, hydroxyethyliminodiacetic acid, etc.) may be contained.

The undercoat layer can be formed, for example, by appropriately dissolving or dispersing each necessary component in a solvent to prepare a coating liquid, applying the coating liquid on a support by a known method, and drying the coating liquid. The coating amount (solid content) of the undercoat layer is preferably 0.1 to 100 mg / m ² and more preferably 1 to 30 mg / m ² .

The on-machine development type lithographic printing plate original plate according to the present invention may have a protective layer (sometimes referred to as an overcoat layer) on the specific compound-containing layer. Alternatively, the specific compound-containing layer and the protective layer may be integrated and formed as one layer on the image recording layer.

[Protective layer]
The protective layer has a function of suppressing an image formation inhibitory reaction by blocking oxygen, a function of preventing scratches in the image recording layer, and a function of preventing ablation during high-illuminance laser exposure.

Protective layers with such properties are described, for example, in US Pat. Nos. 3,458,311 and JP-A-55-49729. As the oxygen low-permeability polymer used for the protective layer, either a water-soluble polymer or a water-insoluble polymer can be appropriately selected and used, and if necessary, two or more kinds may be mixed and used. You can also. Specific examples thereof include polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, water-soluble cellulose derivatives, poly (meth) acrylonitrile, and the like.
As the modified polyvinyl alcohol, an acid-modified polyvinyl alcohol having a carboxy group or a sulfo group is preferably used. Specific examples thereof include the modified polyvinyl alcohols described in JP-A-2005-250216 and JP-A-2006-259137.

The protective layer preferably contains an inorganic layered compound in order to enhance the oxygen blocking property. The inorganic layered compound is a particle having a thin flat plate shape, for example, a group of mica such as natural mica and synthetic mica, formula: talc, teniolite, montmorillonite, saponite, hectorite represented by 3MgO · 4SiO · _H2O . Examples include light, zirconium phosphate and the like.
The inorganic layered compound preferably used is a mica compound. Examples of the mica compound include formula: A (B, C) _2-5 D ₄ O ₁₀ (OH, F, O) ₂ [However, A is any of K, Na, Ca, and B and C are It is any of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. ], Mica groups such as natural mica and synthetic mica can be mentioned.

In the mica group, natural mica includes muscovite, paragonite, phlogopite, biotite and lepidolite. As synthetic mica, non-swelling mica such as fluorine gold mica KMg ₃ (AlSi ₃ O ₁₀ ) F ₂ , potash tetrasilicon mica KM g _2.5 Si ₄ O ₁₀ ) F ₂ , and Na tetrasilic mica NaMg _{2. 5} (Si ₄ O ₁₀ ) F ₂ , Na or Li teniolite (Na, Li) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , montmorillonite-based Na or Li hectrite (Na, Li) _1/8 Mg _{2 /} Examples thereof include swelling mica such as ₅ Li _1/8 (Si ₄ O ₁₀ ) F ₂ . In addition, synthetic smectites are also useful.

Among the mica compounds, fluorine-based swelling mica is particularly useful. That is, the swellable synthetic mica has a laminated structure composed of a unit crystal lattice layer having a thickness of about 10 to 15 Å, and the metal atom substitution in the lattice is significantly larger than that of other clay minerals. As a result, the lattice layer causes a positive charge shortage, and in order to compensate for it, cations such as Li ⁺ , Na ⁺ , Ca ²⁺ , and Mg ²⁺ are adsorbed between the layers. The cations intervening between these layers are called exchangeable cations and can be exchanged with various cations. In particular, when the cations between layers are Li ⁺ and Na ⁺ , the bond between the layered crystal lattices is weak because the ionic radius is small, and the cations are greatly swollen by water. When share is applied in that state, it easily cleaves and forms a stable sol in water. Swellable synthetic mica has a strong tendency to this and is particularly preferably used.

As for the shape of the mica compound, from the viewpoint of diffusion control, the thinner the thickness, the better, and the plane size is better as long as it does not impair the smoothness of the coated surface and the permeability of the active light beam. Therefore, the aspect ratio is preferably 20 or more, more preferably 100 or more, and particularly preferably 200 or more. The aspect ratio is the ratio of the major axis to the thickness of the particle, which can be measured, for example, from a micrograph projection of the particle. The larger the aspect ratio, the greater the effect obtained.

The average major axis of the mica compound is preferably 0.3 to 20 μm, more preferably 0.5 to 10 μm, and particularly preferably 1 to 5 μm. The average thickness of the particles is preferably 0.1 μm or less, more preferably 0.05 μm or less, and particularly preferably 0.01 μm or less. Specifically, for example, in the case of a swellable synthetic mica which is a typical compound, the preferred embodiment is such that the thickness is about 1 to 50 nm and the surface size (major axis) is about 1 to 20 μm.

The content of the inorganic layered compound is preferably 0 to 60% by mass, more preferably 3 to 50% by mass, based on the total solid content of the protective layer. Even when a plurality of types of inorganic layered compounds are used in combination, it is preferable that the total amount of the inorganic layered compounds is the above-mentioned content. Oxygen blocking property is improved in the above range, and good sensitivity can be obtained. In addition, it is possible to prevent a decrease in meat-forming property.

The protective layer may contain known additives such as a plasticizer for imparting flexibility, a surfactant for improving coatability, and inorganic fine particles for controlling the slipperiness of the surface. Further, the protective layer may contain the greasing agent described in the image recording layer.

The protective layer can be formed, for example, by appropriately dissolving or dispersing each necessary component in a solvent to prepare a coating liquid, applying the coating liquid on the image recording layer by a known method, and drying the coating liquid. The coating amount (solid content) of the protective layer is preferably 0.01 to 10 g / m ² , more preferably 0.02 to 3 g / m ² , and particularly preferably 0.02 to 1 g / m ² .

As described above, the specific compound-containing layer and the protective layer may be integrated and formed on the image recording layer as one layer. In this case, for the specific compound-containing layer, for example, each component required for the specific compound-containing layer and the protective layer is appropriately dissolved or dispersed in a solvent to prepare a coating liquid, and the coating liquid is applied onto the image recording layer by a known method. It can be formed by applying and drying.

[End sagging shape of lithographic printing plate original plate]
The on-machine development type lithographic printing plate original plate according to the present invention has a sagging shape at the end. As for the sagging shape, it is preferable that the sagging amount X is 25 to 150 μm and the sagging width Y is 70 to 300 μm.

FIG. 1 is a diagram schematically showing a cross-sectional shape of an end portion of a lithographic printing plate original plate.
In FIG. 1, the planographic printing plate original plate 1 has a sagging 2 at its end. Distance X between the upper end of the end surface 1c of the lithographic printing plate original 1 (the boundary point between the sagging 2 and the end surface 1c) and the extension line of the specific compound-containing layer surface (the protective layer surface if a protective layer is further formed) 1a. Is referred to as "sagging amount", and the distance Y between the point at which the specific compound-containing layer surface 1a of the planographic printing plate original plate 1 begins to sag and the extension line of the end surface 1c is referred to as "sagging width".

The amount of sagging at the end is more preferably 35 μm or more, further preferably 40 μm or more. The upper limit of the amount of sagging is preferably 150 μm from the viewpoint of preventing deterioration of on-machine developability due to deterioration of the surface condition of the end portion. When the on-machine developability deteriorates, ink adheres to the remaining image recording layer and causes edge stains. If the amount of sagging is too small, the ink adhering to the end portion is likely to be transferred to the blanket, which may cause edge stains. When the range of the amount of sagging is 25 to 150 μm, if the sagging width is small, the generation of cracks at the edges increases, and the printing ink accumulates there, which causes edge stains. From such a viewpoint, the sagging width is preferably in the range of 70 to 300 μm, more preferably in the range of 80 to 250 μm. The amount of sagging and the range of sagging width are not related to the edge shape of the support surface 1b of the planographic printing plate original plate 1.
Normally, at the end of the lithographic printing plate original plate 1, the boundary B between the image recording layer and the support and the support surface 1b also have sagging as in the case of the specific compound-containing layer surface 1a.

The end portion having the sagging shape can be formed, for example, by adjusting the cutting conditions of the planographic printing plate original plate.
Specifically, this can be performed by adjusting the gap between the upper cutting blade and the lower cutting blade, the biting amount, the cutting edge angle, and the like in the slitter device used when cutting the lithographic printing plate original plate.
For example, FIG. 2 is a conceptual diagram showing a cut portion of a slitter device. A pair of upper and lower cutting blades 10 and 20 are arranged on the left and right sides of the slitter device. The cutting blades 10 and 20 are round blades on a disk, and the upper cutting blades 10a and 10b are supported coaxially with the rotating shaft 11, and the lower cutting blades 20a and 20b are supported coaxially with the rotating shaft 21. The upper cutting blades 10a and 10b and the lower cutting blades 20a and 20b are rotated in opposite directions. The planographic printing plate original plate 30 is passed between the upper cutting blades 10a and 10b and the lower cutting blades 20a and 20b and cut to a predetermined width. By adjusting the gap between the upper cutting blade 10a and the lower cutting blade 20a and the gap between the upper cutting blade 10b and the lower cutting blade 20b of the cutting portion of the slitter device, an end portion having a sagging shape can be formed. ..

In the machine-developed lithographic printing plate original plate according to the present invention, the area ratio of cracks existing on the surface of the anodic oxide film in the region corresponding to the sagging width Y is 20% or less from the viewpoint of further suppressing edge stains. It is preferable to have.
Here, the region corresponding to the sagging width Y is from the intersection of the extension line of the specific compound-containing layer surface (the protective layer surface when the protective layer is further formed) 1a and the extension line of the end surface 1c in FIG. The extension line of 1a means a region until the specific compound-containing layer surface (or the protective layer surface when a protective layer is further formed) comes into contact with the specific compound-containing layer surface.

The area ratio of cracks existing on the surface of the anodic oxide film is calculated by the following method.
The constituent layers (undercoat layer, image recording layer, specific compound-containing layer, protective layer) of the lithographic printing plate original plate are removed using PlasmaReactor PR300 manufactured by Yamato Scientific Co., Ltd. A sample is prepared by subjecting the surface of the anodic oxide film of the exposed aluminum support to a 3 nm vapor deposition of a Pt-Pd film and conducting a conductive treatment. This sample was observed by SEM at an acceleration voltage of 30 kV using an S-4800 type field emission scanning electron microscope (FE-SEM) manufactured by Hitachi High-Technologies Co., Ltd., and the observation magnification was 1,500 times from the end to the center. A series of photographs are taken toward the section to obtain an image of 150 × 50 μm. For this image, the crack shape is extracted by using the image processing software using the difference in brightness between the crack portion and the surface of the anodized film layer, and binarization processing is performed to calculate the crack ratio in the range of 150 × 50 μm. The area ratio of cracks.

The area ratio of cracks is particularly preferably 10% or less from the viewpoint of preventing the occurrence of edge stains.

In order to adjust the area ratio of cracks existing on the surface of the anodized film to 10% or less in the region corresponding to the sagging width Y, the amount of the anodized film of the anodized film is 0.5 to 5.0 g / g. It is preferable to control it within the range of m ² . The amount of the anodic oxide film is more preferably controlled in the range of 0.8 to 1.2 g / m ² from the viewpoint of further suppressing edge stains.

The amount of the anodic oxide film of the anodic oxide film is calculated by the following method.
The constituent layers (undercoat layer, image recording layer, specific compound-containing layer, protective layer) of the lithographic printing plate precursor are removed using PlasmaReactor PR300 manufactured by Yamato Scientific Co., Ltd. The surface of the anodic oxide film of the exposed aluminum support was measured with a fluorescent X-ray analyzer (ZSX PrimusII manufactured by Rigaku Co., Ltd.), and the amount of anodic oxide film (g / g /) of the anodic oxide film was measured using a calibration curve prepared separately. Calculate m ² ). The calibration curve was created from the relationship between the Compton scattered radiation intensity obtained from the fluorescent X-ray analyzer and the amount of the anodic oxide film calculated by the Mason method. In order to improve the measurement accuracy of the Mason method, all new Mason solutions were used. The conditions for X-ray fluorescence analysis are as follows. X-ray tube: Rh, measurement spectrum: RhLα, tube voltage: 50 kV, tube current: 60 mA, slit: S2, spectroscopic crystal: Ge, detector: PC, analysis area: 30 mmφ, peak position (2θ): 89.510 deg .. , Background (2θ): 87.000deg. And 92.000 deg. , Accumulated time: 60 seconds / sample

In order to control the amount of the anodic oxide film of the anodic oxide film, for example, a method of adjusting the electrolysis time in the anodic oxidation treatment can be mentioned.

In order to adjust the area ratio of cracks existing on the surface of the anodic oxide film to 10% or less in the region corresponding to the sagging width Y, the average diameter of the micropores existing on the surface of the anodic oxide film is 5 to 35 nm. It is preferable to control within the range of.

The average diameter of the micropores of the anodic oxide film is calculated by the following method.
The constituent layers (undercoat layer, image recording layer, specific compound-containing layer, protective layer) of the lithographic printing plate original plate are removed by using PlasmaReactor PR300 manufactured by Yamato Scientific Co., Ltd. A sample is prepared by subjecting the surface of the anodic oxide film of the exposed aluminum support to a vapor deposition of carbon or Pt-Pd film at 3 nm and conducting a conductive treatment. Using an S-4800 field emission scanning electron microscope (FE-SEM) manufactured by Hitachi High-Technologies Corporation, this sample was continuously photographed from the end to the center at an observation magnification of 150,000 times. , Four images of 400 × 600 nm are obtained. The diameters of 90 micropores present in these four images are measured and averaged to obtain the average diameter of the micropores. When the shape of the micropore is not circular, a circle having the same projected area as the projected area of the micropore is assumed, and the diameter of the circle is defined as the diameter of the micropore.

In order to control the average diameter of the micropores of the anodic oxide film, for example, a method of adjusting the treatment time in the pore wide treatment can be mentioned.

The machine-developing lithographic printing plate original plate according to the present invention has a sagging shape at the end and has a specific compound-containing layer on the image recording layer, so that the image-forming property and the machine-developing property of the edge are formed. It has a feature that it can show good edge stain prevention even after long-term storage without deteriorating such characteristics.
Further, in the machine-developed lithographic printing plate original plate according to the present invention, a good edge is obtained even after long-term storage without subjecting the end portion to a hydrophilization treatment such as applying a coating liquid containing a water-soluble compound. It has the feature of being able to show antifouling properties.
The reason is not clear, but it is presumed to be as follows.
The on-machine development type lithographic printing plate original plate according to the present invention has a specific compound-containing layer on the image recording layer. Even if the polymerizable compound in the image-forming layer is subjected to dark polymerization with an active species under long-term storage, the specific compound contained in the specific compound-containing layer is present in a layer different from the image recording layer, and the image is imaged. It is less susceptible to the effects of the recording layer. Therefore, the specific compound is eluted with at least one selected from printing ink and dampening water, and moved to the end of the machine-developed lithographic printing plate original plate to make the end hydrophilic. It is presumed that the edge stain prevention property will be further improved.
Further, since the machine-developed planographic printing plate dummy plate described later usually does not have an image recording layer, it is presumed that it exhibits good edge stain prevention even under long-term storage.

[How to make a lithographic printing plate]
The method for producing a lithographic printing plate according to the present invention includes a step of image-exposing the lithographic printing plate original plate according to the present invention (exposure step), and printing ink and wetting the lithographic printing plate original plate after image exposure on a printing machine. A step (on-machine development step) of removing an unexposed portion of the image recording layer with at least one of water is included.

[Exposure process]
The image exposure is preferably performed by a method of scanning and exposing digital data with an infrared laser or the like.
The wavelength of the exposure light source is preferably 750 to 1,400 nm. As a light source having a diameter of 750 to 1,400 nm, a solid-state laser or a semiconductor laser that emits infrared rays is suitable. The exposure mechanism may be any of an inner drum method, an outer drum method, a flatbed method and the like.
The exposure step can be performed by a known method using a platesetter or the like. Further, a printing machine provided with an exposure apparatus may be used to mount the lithographic printing plate original plate on the printing machine and then perform exposure on the printing machine.

[In-machine development process]
In the on-machine development process, when printing is started by supplying printing ink and dampening water on the printing machine without performing any development processing on the lithographic printing plate original plate after image exposure, the initial stage during printing is performed. The unexposed portion of the lithographic printing plate original plate is removed, and the surface of the hydrophilic support is exposed accordingly to form a non-image portion. As the printing ink and dampening water, known printing inks and dampening water for lithographic printing are used. The surface of the lithographic printing plate precursor may be supplied with printing ink or dampening water first, but the printing ink is first supplied in order to prevent the dampening water from being contaminated by the removed image recording layer component. Is preferable to supply.
In this way, the lithographic printing plate original plate is developed on the offset printing machine and used as it is for printing a large number of sheets.

The method for producing a lithographic printing plate according to the present invention may include other known steps in addition to the above steps. Examples of other steps include a plate inspection step of confirming the position and orientation of the lithographic printing plate original plate before each step, a confirmation step of confirming a printed image after the on-machine development step, and the like.

[In-machine development type lithographic printing plate dummy plate]
In the field of multicolor printing such as color newspaper printing, when it is necessary to print a part of the paper surface in two colors or one color, etc., in the part that does not require printing on the plate cylinder of the printing machine, Printing may be performed by attaching a dummy plate instead of the printing plate. Such dummy plates are sometimes referred to as waste plates, water plates, and blank plates.
The present invention also relates to a dummy plate, specifically, an on-machine development type lithographic printing plate dummy plate.

The on-machine development type lithographic printing plate dummy plate according to the present invention is an on-machine development type lithographic printing plate dummy plate having a polymer layer on an aluminum support having an anodized film, and the above-mentioned lithographic printing plate dummy plate is an end. In-plane of the layer having a sagging shape in the portion, having a layer containing a compound having support adsorbability on the polymer layer, and having a content of the compound containing the compound having the support adsorbability. It is an on-board development type lithographic printing plate dummy plate that is substantially the same in the above.

[Aluminum support with anodic oxide film]
The aluminum support having an anodic oxide film constituting the machine-developed lithographic printing plate original plate is not particularly limited, but is the same as the aluminum support having an anodic oxide film constituting the above-mentioned machine-developed lithographic printing plate original plate. Can be mentioned.

[Polymer layer]
The polymer layer constituting the machine-developed planographic printing plate dummy plate exists on an aluminum support having an anodic oxide film.
The polymer layer preferably contains a binder polymer. As the binder polymer of the polymer layer, a polymer having a film-forming property is suitable. Examples of the binder polymer contained in the polymer layer include polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, a water-soluble cellulose derivative, poly (meth) acrylonitrile, and the like.
As the modified polyvinyl alcohol, an acid-modified polyvinyl alcohol having a carboxy group or a sulfo group is preferably used. Specific examples thereof include the modified polyvinyl alcohols described in JP-A-2005-250216 and JP-A-2006-259137.

As the binder polymer of the polymer layer, a water-soluble polymer compound containing a repeating unit having a support-adsorbing group and a repeating unit having a hydrophilic group is particularly preferable. As a result, the on-machine developability of the planographic printing plate dummy plate itself is improved, and edge stains are suppressed. Edge stains are those that adhere to the edges of the lithographic printing plate dummy plate because the edges of the lithographic printing plate dummy plate are inside the printing paper surface when printing continuously on roll-shaped printing paper using a rotary machine such as newspaper printing. This is a phenomenon in which the printed ink is transferred to printing paper and causes linear stains.

Hereinafter, the water-soluble polymer compound containing a repeating unit having a support-adsorbing group and a repeating unit having a hydrophilic group will be described in detail.

(Support adsorptive group)
Examples of the support adsorptive group include mutual ionic bond formation, hydrogen bond formation, polar interaction, etc. with metals, metal oxides, hydroxy groups, etc. existing on the support subjected to anodization treatment or hydrophilization treatment. Examples include groups capable of action.
Specific examples of the support adsorptive group are given below.

In the formula, M ¹ and M ² independently represent a hydrogen atom, a metal atom contained in an alkali metal or an alkaline earth metal, or an ammonium group. From the viewpoint of stain resistance, the support adsorptive group is preferably at least one group selected from a phosphonic acid group, a phosphoric acid group, a carboxylic acid group and salts thereof. The support adsorptive group is more preferably a phosphonic acid group or a salt thereof (Structure 1), a phosphate ester group or a salt thereof (Structure 2), a carboxylic acid group or a salt thereof, and a phosphoric acid ester group or a salt thereof. Alternatively, it is more preferably a phosphonic acid group or a salt thereof.
The repeating unit having a support-adsorbing group is preferably represented by the following general formula (B1).

In the formula (B1 ^{), Ra to R c independently} represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. Q represents a support adsorptive group, and the preferred embodiment is the same as described above.
L represents a single bond or a divalent linking group. Divalent linking groups are 1 to 60 carbon atoms, 0 to 10 nitrogen atoms, 0 to 50 oxygen atoms, 1 to 100 hydrogen atoms, and 0 to 0. It is composed of up to 20 sulfur atoms, and more specifically, the following structural units or those composed of a combination thereof can be mentioned.

In the above structure, R ^d and ^Re each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom. n represents an integer of 1 to 4.

Specific examples of the repeating unit having a support-adsorbing group are shown below, but the present invention is not limited thereto.

The polymer compound may have only one type of support-adsorbing group or may have two or more types.
The content of the repeating unit having a support-adsorptive group is preferably 2 to 80 mol%, more preferably 2 to 70 mol%, still more preferably 5 to 50 mol%, based on all the repeating units of the polymer compound. 10-40 mol% is particularly preferred.

(Hydrophilic group)
The polymer compound has a repeating unit having a hydrophilic group in order to increase the hydrophilicity of the surface of the aluminum support support and suppress etch stains.
Specific examples of hydrophilic groups are given below.

In the above formula, M ¹ represents a hydrogen atom, a metal atom contained in an alkali metal or an alkaline earth metal, or an ammonium group.
X ⁺ represents a group represented by -N ⁺ R ₁ R _2- , -S ⁺ R _1- , -I ⁺ -, -P ⁺ R ₁ R _2- .
R ₁ and R ₂ independently represent a hydrogen atom, an alkyl group, an aryl group, an alkenyl group or an alkynyl group, R ₃ represents an alkylene group, and R ₄ represents an alkyl group, an aryl group, an alkenyl group or an alkynyl group. Represents.
n represents an integer from 1 to 100. L is synonymous with the above-mentioned L.

As the hydrophilic group, any functional group having a high affinity with water can be preferably used, but a sulfonic acid (salt) group, an amide group, a polyalkylene oxide group, a hydroxyl group, and a sulfate mono Ester (salt) group, sulfonamide group, amino group, sulfate monoamide (salt) group, betaine structure are preferable, sulfonic acid (salt) group, amide group, polyalkylene oxide group, hydroxyl group, sulfate monoester (salt) group. , Sulfonamide group, amino group, sulfate monoamide (salt) group and betaine structure are more preferable, and sulfonic acid (salt) group, amide group, polyalkylene oxide group, hydroxyl group and betaine structure are particularly preferable.
The hydrophilic group is particularly preferably at least one group or structure selected from a sulfonic acid group and a salt thereof, an amide group and a betaine structure.

The repeating unit having a hydrophilic group is preferably represented by the following general formula (B2).

In the formula (B2 ^{), Ra to R c independently} represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. L is synonymous with the above-mentioned L. W represents a hydrophilic group, and preferred embodiments are the same as those described above.

Specific examples of the repeating unit having a hydrophilic group are shown below, but the present invention is not limited thereto.

The polymer compound may have only one type of hydrophilic group or two or more types.
The content of the repeating unit having a hydrophilic group is preferably 30 to 98 mol%, more preferably 40 to 90 mol%, still more preferably 50 to 90 mol%, based on all the repeating units of the polymer compound.

(Other repeating units)
The polymer compound has other repeating units (hereinafter, may be simply referred to as “other repeating units”) in addition to the repeating unit having a support-adsorbing group and the repeating unit having a hydrophilic group. It may be a copolymer. Other repeating units include repeating units derived from various known monomers.

The polymer compound may be, for example, a repeating unit having a support-adsorbing group, a repeating unit having a hydrophilic group, a repeating unit corresponding to an alkyl (meth) acrylate or an aralkyl ester, (meth) acrylamide or a repeating unit thereof. It may have a repeating unit corresponding to a derivative, a repeating unit corresponding to α-hydroxymethyl acrylate, and a repeating unit corresponding to a styrene derivative.
The alkyl group of the (meth) acrylic acid alkyl ester is preferably an alkyl group having 1 to 5 carbon atoms and the above-mentioned substituent having 2 to 8 carbon atoms, and a methyl group is more preferable. Examples of the (meth) acrylic acid aralkyl ester include benzyl (meth) acrylic acid.
Examples of the (meth) acrylamide derivative include N-isopropylacrylamide, N-phenylmethacrylamide, N- (4-methoxycarbonylphenyl) metaacrylamide, N, N-dimethylacrylamide, morpholinoacrylamide and the like.
Examples of the α-hydroxymethyl acrylate include ethyl α-hydroxymethyl acrylate and cyclohexyl α-hydroxymethyl acrylate.
Examples of the styrene derivative include styrene and 4-tert-butyl styrene.

The content of the other repeating units is preferably 40 mol% or less, more preferably 30 mol%, still more preferably 20 mol% or less, based on all the repeating units of the polymer compound.

The polymer compound has a repeating unit having at least one group selected from a phosphonic acid group, a phosphoric acid group, a carboxylic acid group and a salt thereof as the support adsorptive group, and a sulfonic acid group as the hydrophilic group. Particularly preferred is a copolymer comprising the salt, an amide group and a repeating unit having at least one group or structure selected from the betaine structure.

As the binder polymer contained in the polymer layer, one kind may be used alone, or two or more kinds may be mixed and used.
The polymer layer may be one layer or two or more layers.
The content of the binder polymer in the polymer layer is preferably 10 to 100% by mass, more preferably 30 to 95% by mass, still more preferably 40 to 90% by mass, based on the total solid content of the polymer layer.

[Undercoat layer]
The machine-developed planographic printing plate dummy plate according to the present invention may have an undercoat layer (sometimes referred to as an intermediate layer) between the polymer layer and the support.
The undercoat layer is not particularly limited, but the undercoat layer (sometimes referred to as an intermediate layer) that the machine-developed planographic printing plate original plate may have between the image recording layer and the support is provided. Can be mentioned. Since the undercoat layer contains a polymer, the undercoat layer corresponds to a polymer layer.

[Layer containing a compound having support adsorptivity]
The on-machine development type lithographic printing plate dummy plate according to the present invention has a layer containing a compound having support-adsorbing property on the polymer layer.
The layer containing the compound having the support adsorptive property constituting the machine-developed lithographic printing plate dummy plate is the same as the layer containing the compound having the support adsorptive property constituting the above-mentioned machine-developing lithographic printing plate original plate. Is.

[Protective layer]
The on-machine development type lithographic printing plate dummy plate according to the present invention has a protective layer (sometimes referred to as an overcoat layer) on a layer containing a compound having a support-adsorbing property (specific compound-containing layer). be able to. Alternatively, the layer containing the compound having the support-adsorbing property and the protective layer may be integrated and formed as one layer on the layer containing the compound having the support-adsorbing property.
The protective layer that the machine-developed lithographic printing plate dummy plate may have is the same as the protective layer that the machine-developed lithographic printing plate original plate may have.
As described above, the layer containing the compound having the support-adsorbing property and the protective layer may be integrated and formed on the polymer layer as one layer. In this case, for the layer containing the compound having the support adsorptive property, for example, each component required for the layer containing the compound having the support adsorbability and the protective layer is appropriately dissolved or dispersed in a solvent to prepare a coating liquid. Then, the coating liquid can be formed by applying the coating liquid on the image recording layer by a known method and drying it.

[Dripping shape at the end of the machine-developed planographic printing plate dummy plate]
The on-machine development type lithographic printing plate dummy plate according to the present invention has a sagging shape at the end.
The sagging shape is the same as the sagging shape described as the sagging shape that the machine-developed planographic printing plate original plate has at the end.

[Printing method]
The printing method according to the present invention includes the above-mentioned on-machine development type lithographic printing plate dummy plate and the step of on-machine developing the on-machine developing type lithographic printing plate original plate having an image recording layer on an aluminum support.
More specifically, the printing method according to the present invention has the on-machine development type lithographic printing plate dummy plate mounted on the same plate cylinder of the printing machine, and an image recording layer on an aluminum support. On-machine development type lithographic printing plate Includes the process of on-machine development of the original plate.

In the printing method according to the present invention, for example, the above-mentioned machine-developing lithographic printing plate dummy plate and the above-mentioned machine-developing lithographic printing plate original plate are mounted on the same plate cylinder of the printing machine. As the printing machine, for example, an offset rotary printing machine for newspapers (manufactured by Tokyo Kikai Seisakusho Co., Ltd., Mitsubishi Heavy Industries, Ltd., etc.) is used.
After that, printing is performed by a normal method. That is, when the dampening water and the printing ink are supplied, the constituent layers of the machine-developed lithographic printing plate dummy plate and the machine-developed lithographic printing plate original plate are melted or dissolved by the supplied dampening water and / or the printing ink. The surface is dispersed and removed, and the surface of the hydrophilic aluminum support or the aluminum support on which the hydrophilic undercoat layer component is adsorbed on the surface is exposed. As a result, the dampening water adheres to the exposed hydrophilic surface, and the adhesion of the printing ink is prevented.
Here, the surface of the machine-developed lithographic printing plate dummy plate and the machine-developing lithographic printing plate original plate may be supplied first with dampening water or printing ink, but is configured by permeating the fountain solution. In order to promote the on-machine developability of the layer, it is preferable to supply dampening water first.

The machine-developed lithographic printing plate original plate is image-exposed according to a conventional method before being mounted on the plate cylinder of the printing machine. The image exposure is preferably performed by a method of scanning and exposing digital data with an infrared laser or the like.
The wavelength of the exposure light source is preferably 750 to 1,400 nm. As a light source having a diameter of 750 to 1,400 nm, a solid-state laser or a semiconductor laser that emits infrared rays is suitable. The exposure mechanism may be any of an inner drum method, an outer drum method, a flatbed method and the like.
Image exposure can be performed by a known method using a platesetter or the like. Further, using a printing machine equipped with an exposure device, the on-machine development type lithographic printing plate original plate may be mounted on the printing machine and then exposed on the printing machine.

The on-board development type lithographic printing plate original plate used in the above printing method has an image recording layer on an aluminum support.
As the aluminum support, a known aluminum support (including an aluminum alloy support) used for the lithographic printing plate original plate is used. Among them, an aluminum plate that has been roughened and anodized by a known method is preferably used.
The aluminum support is not particularly limited, but is the above-mentioned "on-machine development type lithographic printing plate original plate having an image recording layer on an aluminum support having an anodic oxide film, and the lithographic printing plate original plate has a sagging shape at the end. The image recording layer has a layer containing a compound having a support-adsorbing property, and the content of the compound is substantially the same in the plane of the layer containing the compound having a support-adsorbing property. The same as "aluminum support having an anodic oxide film" in "a certain on-board development type lithographic printing plate original plate" can be mentioned.

The image recording layer in the on-board development type lithographic printing plate original plate used in the above printing method is not particularly limited, but the above-mentioned "on-machine development type lithographic printing plate having an image recording layer on an aluminum support having an anodic oxide film" is not particularly limited. It is an original plate, and the lithographic printing plate original plate has a sagging shape at the end, has a layer containing a compound having support adsorbability on the image recording layer, and the content of the compound is the support adsorbability. The same as those described in the image recording layer in the "on-machine development type lithographic printing plate original plate" which is substantially the same in the plane of the layer containing the compound having the above can be mentioned.

The image recording layer in the machine-developed lithographic printing plate precursor used in the above printing method preferably contains a polymerization initiator.
The polymerization initiator is not particularly limited, but is the above-mentioned "on-machine development type flat plate printing plate original plate having an image recording layer on an aluminum support having an anodized film, and the flat plate printing plate original plate has a sagging shape at the end. And has a layer containing a compound having support adsorbability on the image recording layer, and the content of the compound is substantially the same in the plane of the layer containing the compound having pre-support adsorbability. The same as those described in the polymerization initiator that may be contained in the image recording layer in the “on-board development type flat plate printing plate original plate” can be mentioned.

It is also preferable that the image recording layer in the on-board development type lithographic printing plate original plate used in the above printing method contains a polymerization initiator containing an organoboron-containing anion.

In the polymerization initiator containing an organoboron-containing anion, the tetraarylborate anion is preferable as the organoboron-containing anion.
The tetraarylborate anion is represented by the following general formula (I).

General formula (I)

In the general formula (I), R ₁ , R ₂ , R ₃ and R ₄ independently represent an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 5 to 20 carbon atoms. Aryl groups and heteroaryl groups may have substituents. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, an aryl group and the like.
Specific examples of the aryl group include phenyl group, tolyl group, xylyl group, mesityl group, juryl group, methoxyphenyl group, dimethoxyphenyl group, chlorophenyl group, fluorophenyl group, trifluoromethylphenyl group, pentafluorophenyl group and naphthyl. And so on. Specific examples of the heteroaryl group include a pyridyl group, a pyrimidyl group, a furanyl group, a pyrrolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an indolyl group, a quinolinyl group, an oxadiazolyl group, a benzoxazolyl group and the like.
In the general formula (I), R ₁ , R ₂ , R ₃ and R ₄ are preferably substituted or unsubstituted phenyl groups. It is more preferred that at least three of R ₁ , R ₂ , R ₃ and R ₄ are the same substituted or unsubstituted phenyl group.

In the polymerization initiator containing an organic boron-containing anion, an iodonium cation is preferable as a cation forming a counterion of the organic boron-containing anion, and a diaryliodonium cation is particularly preferable. As the diallyl iodonium cation, the compound represented by the structure (I) of US Pat. No. 7,524,614 is suitable.

Among the polymerization initiators containing an organoboron-containing anion, an iodonium compound containing an organoboron-containing anion and a diallyl iodonium cation is preferable.
Specific examples of the iodonium compound containing an organic boron-containing anion and a diaryliodonium cation include 4-octyloxyphenylphenyliodonium tetraphenylborate, [4-[(2-hydroxytetradecyl) oxy] phenyl] phenyliodonium tetraphenylborate, Bis (4-tert-butylphenyl) iodonium tetraphenylborate, 4-methylphenyl-4'-hexylphenyl iodonium tetraphenylborate, 4-methylphenyl-4'-cyclohexylphenyliodonium tetraphenylborate, bis (tert-butylphenyl) ) Iodium tetrakis (pentafluorophenyl) borate, 4-hexylphenylphenyliodonium tetraphenylborate, 4-cyclohexylphenylphenyliodonium tetraphenylborate, 2-methyl-4-tert-butylphenyl-4'-methylphenyliodonium tetraphenylborate , 4-Methylphenyl-4'-dodecylphenyl iodonium tetrakis (4-fluorophenyl) borate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, and bis (4-tert-butylphenyl) iodonium tetrakis (1- Imidazolyl) Borate and the like, but are not limited to these. Among these, bis (4-tert-butylphenyl) iodonium tetraphenylborate, 4-methylphenyl-4'-hexylphenyl iodonium tetraphenylborate, 2-methyl-4-tert-butylphenyl-4'-methylphenyl Iodonium tetraphenylborate and 4-methylphenyl-4'-cyclohexylphenyliodonium tetraphenylborate are preferred.

As the polymerization initiator containing an organoboron-containing anion, one type may be used alone, or two or more types may be used in combination.
The content of the polymerization initiator containing the organoboron-containing anion is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, and 0.8 to 20% by mass with respect to the total solid content of the image recording layer. Mass% is particularly preferred.

The image recording layer in the machine-developed lithographic printing plate precursor used in the above printing method preferably contains polymer particles.
The polymer particles are not particularly limited, but are the above-mentioned "on-machine development type lithographic printing plate original plate having an image recording layer on an aluminum support having an anodic oxide film, and the lithographic printing plate original plate has a sagging shape at the end. It has a layer containing a compound having support adsorbability on the image recording layer, and the content of the compound is substantially the same in the plane of the layer containing the compound having support adsorbability. Examples of the same as those described in the polymer particles that may be contained in the image recording layer in the "on-machine development type lithographic printing plate original plate" can be mentioned.

The polymer particles are preferably copolymer particles containing styrene and acrylonitrile.
The polymer particles are preferably microgels.

The machine-developed lithographic printing plate original plate used in the printing method of the present invention may have an undercoat layer (sometimes referred to as an intermediate layer) between the image recording layer and the support.
The undercoat layer is the above-mentioned "on-machine development type lithographic printing plate original plate having an image recording layer on an aluminum support having an anodic oxide film, and the lithographic printing plate original plate has a sagging shape at the end and is an image recording layer. On-machine development lithographic printing, which has a layer containing a compound having a support-adsorbing property on the surface, and the content of the compound is substantially the same in the plane of the layer containing the compound having a support-adsorbing property. It is the same as that described in the undercoat layer that the "plate original plate" may have.

The on-machine development type lithographic printing plate original plate used in the printing method of the present invention may have a protective layer (sometimes referred to as an overcoat layer) on the image recording layer.
The protective layer is the above-mentioned "on-machine development type lithographic printing plate original plate having an image recording layer on an aluminum support having an anodic oxide film, and the lithographic printing plate original plate has a sagging shape at an end and is an image recording layer. On-machine development lithographic printing, which has a layer containing a compound having a support-adsorbing property on the surface, and the content of the compound is substantially the same in the plane of the layer containing the compound having a support-adsorbing property. It is the same as that described in the protective layer that the "plate original plate" may have.

The on-machine development type lithographic printing plate dummy plate according to the present invention has characteristics such as on-machine developability at the end by having a sagging shape at the end and having a specific compound-containing layer on the polymer layer. It has a feature that it can show good edge stain prevention even after long-term storage without lowering it.
In the machine-developed lithographic printing plate dummy plate according to the present invention, good edge stains are obtained even after long-term storage without subjecting the end portion to a hydrophilization treatment such as applying a coating liquid containing a water-soluble compound. It has the feature that it can show preventiveness.
In the printing method according to the present invention, in the machine-developed planographic printing plate dummy plate according to the present invention, the end portion is not subjected to a hydrophilization treatment such as applying a coating liquid containing a water-soluble compound, which is good. It has a feature that it can show a good edge stain prevention property.
In the printing method according to the present invention, in the machine-developed planographic printing plate dummy plate according to the present invention, the end portion is not subjected to a hydrophilization treatment such as applying a coating liquid containing a water-soluble compound, which is good. It has a feature that it can show a good edge stain prevention property.
Further, in the process of on-machine developing the machine-developed lithographic printing plate dummy plate and the machine-developing lithographic printing plate original plate in the printing method according to the present invention, the support adsorption property of the machine-developing lithographic printing plate dummy plate is improved. The specific compound in the layer containing the compound is eluted with at least one selected from printing ink and dampening water, and the end of the machine-developed lithographic printing plate original dummy plate and the machine-developed lithographic printing plate original plate. By moving to the end portion, the end portion can be made hydrophilic, and it has a feature that good edge stain prevention property can be exhibited.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto. In the polymer compound, the molecular weight is the mass average molecular weight (Mw) as a polystyrene-equivalent value by the gel permeation chromatography (GPC) method, and the ratio of the repeating unit is a molar percentage, except for those specified specifically. Further, "part" and "%" mean "parts by mass" and "% by mass" unless otherwise specified.

[Examples 1 to 25 and Comparative Examples 1 to 2]

<Preparation of support (1)>

The following treatments (a) to (g) were sequentially applied to the aluminum plate to prepare an aluminum support (support (1)) having an anodic oxide film. A water washing treatment was performed between all the treatment steps.

(A) Alkaline etching treatment An aqueous solution having a Kasei soda concentration of 25% by mass, an aluminum ion concentration of 100 g / L, and a temperature of 60 ° C. is sprayed onto an aluminum plate (material JIS 1052) having a thickness of 0.3 mm from a spray tube to perform etching treatment. rice field. The etching amount of the surface of the aluminum plate to be subjected to the electrochemical roughening treatment was 3 g / m ² .

(B) Desmat treatment Desmat treatment was performed by spraying an aqueous sulfuric acid solution (concentration 300 g / L) at a temperature of 35 ° C. on an aluminum plate from a spray tube for 5 seconds.

(C) Electrochemical roughening treatment Using an electrolytic solution (liquid temperature 35 ° C.) in which aluminum chloride was dissolved in a 1% by mass hydrochloric acid aqueous solution to adjust the aluminum ion concentration to 4.5 g / L, the aluminum plate was subjected to 60 Hz. Using an AC power source, the electrochemical roughening treatment was continuously performed using a flat cell type electrolytic cell. A sine wave was used as the waveform of the AC power supply. In the electrochemical roughening treatment, the current density during the anode reaction of the aluminum plate at the peak of alternating current was 30 A / dm ² . The ratio of the total amount of electricity during the anode reaction to the total amount of electricity during the cathode reaction of the aluminum plate was 0.95. The total amount of electricity at the anode of the aluminum plate was 480 C / dm ² . The electrolytic cell was stirred in the electrolytic cell by circulating the liquid using a pump.

(D) Alkaline etching treatment An aqueous solution having a caustic soda concentration of 5% by mass, an aluminum ion concentration of 5 g / L, and a temperature of 35 ° C. was sprayed onto an aluminum plate from a spray tube to perform an etching treatment. The etching amount of the surface of the aluminum plate subjected to the electrochemical roughening treatment was 0.05 g / m ² .

(E) Desmat treatment Desmat treatment was performed by spraying an aqueous solution having a sulfuric acid concentration of 300 g / L, an aluminum ion concentration of 5 g / L, and a liquid temperature of 35 ° C. on an aluminum plate from a spray tube for 5 seconds.

(F) Anodizing treatment Using an electrolytic solution of 15% by mass sulfuric acid (containing 0.5% by mass of aluminum ions), a DC anodizing film having a thickness of 1,000 nm under the conditions of 40 ° C. and a current density of 15 A / dm ² . Was provided. Then, it was washed with water by spraying.

(G) Pore Wide Treatment An aluminum plate was treated with an alkali at 35 ° C. for 15 seconds using a 5% NaOH aqueous solution to prepare a support (1). The average diameter of the micropores of the anodic oxide film of the support (1) was 25 nm. The average diameter of the micropores of the anodic oxide film is a numerical value calculated according to the method described above (the same applies hereinafter).

<Preparation of support (2)>
In the production of the support (1), the support (2) is formed in the same manner as in the production of the support (1), except that the time of the anodizing treatment is adjusted so that the thickness of the anodizing film is 750 nm. Made. The average diameter of the micropores of the anodic oxide film of the support (2) was 25 nm.

<Preparation of support (3)>
In the production of the support (1), the support (3) is formed in the same manner as in the production of the support (1), except that the time of the anodizing treatment is adjusted so that the thickness of the anodizing film is 500 nm. Made. The average diameter of the micropores of the anodic oxide film of the support (3) was 25 nm.

<Preparation of support (4)>
In the production of the support (1), the support (4) was produced in the same manner as the production of the support (1) except that the (f) anodizing treatment was changed as follows. The average diameter of the micropores of the anodic oxide film of the support (4) was 35 nm.

(F) Anodic oxidation treatment A DC anodic oxide film having a thickness of 500 nm was provided under the conditions of 38 ° C. and a current density of 15 A / dm ² using an electrolytic solution of a 22 mass% phosphoric acid aqueous solution. Then, it was washed with water by spraying.

<Formation of image recording layer (1)>
An image recording layer coating liquid (1) having the following composition is bar-coated on the support and dried in an oven at 100 ° C. for 60 seconds to form an image recording layer (1) having a dry coating amount of 1.0 g / m ² . bottom.
The image recording layer coating liquid (1) was prepared by mixing and stirring the following photosensitive liquid (1) and microgel liquid immediately before coating.

<Photosensitive liquid (1)>
-Binder polymer (1) [following structure] 0.240 parts-polymerization initiator (1) [following structure] 0.245 parts-infrared absorber (1) [following structure] 0.046 parts-borate compound 0.010 Part TPB [Structure below]
-Polymerable compound 0.192 parts Tris (acryloyloxyethyl) isocyanurate (NK ester A-9300, manufactured by Shin-Nakamura Chemical Co., Ltd.)
-Small molecule hydrophilic compound 0.062 parts Tris (2-hydroxyethyl) isocyanurate-Small molecule hydrophilic compound (1) [The following structure] 0.050 parts-Fluorosurfactant (1) [The following structure] 0 .008 parts ・ 2-butanone 1.091 parts ・ 1-methoxy-2-propanol 8.609 parts

<Microgel liquid>
・ Microgel (1) 2.640 parts ・ Distilled water 2.425 parts

Structure of binder polymer (1), polymerization initiator (1), infrared absorber (1), TPB, small molecule hydrophilic compound (1) and fluorine-based surfactant (1) used in the photosensitive liquid (1). Is shown below.

The preparation method of the microgel (1) used in the above microgel solution is shown below.
<Preparation of multivalent isocyanate compound (1)>
Bismuth tris (2-ethylhexanoate) (neostan U) in a suspension solution of ethyl acetate (25.31 g) containing 17.78 g (80 mmol) of isophorone diisocyanate and 7.35 g (20 mmol) of the following polyhydric phenol compound (1). -600, 43 mg (manufactured by Nitto Kasei Co., Ltd.) was added and stirred. When the exotherm subsided, the reaction temperature was set to 50 ° C. and the mixture was stirred for 3 hours to obtain an ethyl acetate solution (50% by mass) of the polyhydric isocyanate compound (1).

<Preparation of microgel (1)>
The following oil phase components and aqueous phase components were mixed and emulsified at 12000 rpm for 10 minutes using a homogenizer. After stirring the obtained emulsion at 45 ° C. for 4 hours, 10 mass of 1,8-diazabicyclo [5.4.0] undec-7-en-octylate (U-CAT SA102, manufactured by San-Apro Co., Ltd.) 5.20 g of% aqueous solution was added, the mixture was stirred at room temperature for 30 minutes, and allowed to stand at 45 ° C. for 24 hours. The solid content concentration was adjusted to 20% by mass with distilled water to obtain an aqueous dispersion of microgel (1). When the average particle size was measured by the light scattering method, it was 0.28 μm.

(Oil phase component)
(Component 1) Ethyl acetate: 12.0 g
(Component 2) An adduct (component 2) to which trimethylolpropane (6 mol) and xylene diisocyanate (18 mol) are added, and methyl flank polyoxyethylene (1 mol, number of repetitions of oxyethylene unit: 90) is added thereto (component 2). 50% by mass ethyl acetate solution, manufactured by Mitsui Kagaku Co., Ltd.): 3.76 g
(Component 3) Multivalent isocyanate compound (1) (50% by mass ethyl acetate solution): 15.0 g
(Component 4) 65% by mass ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartmer): 11.54 g
(Component 5) 10% ethyl acetate solution of sulfonate-type surfactant (Pionin A-41-C, manufactured by Takemoto Oil & Fat Co., Ltd .): 4.42 g

(Aquatic phase component) Distilled water: 46.87 g

<Formation of image recording layer (2)>
An image recording layer coating liquid (2) having the following composition is bar-coated on the support and dried in an oven at 94 ° C. for 60 seconds to form an image recording layer (2) having a dry coating amount of 0.85 g / m ² . bottom.

(Image recording layer coating liquid (2))
・ Polymerizable compound 1 ^{* 1} 0.325 parts ・ Graft copolymer 1 ^{* 2} 0.060 parts ・ Graft copolymer 2 ^{* 3} 0.198 parts ・ Mercapto-3-triazole ^{* 4} 0.180 parts ・ Irgure250 ^{* 5} 0.032 Part ・ Infrared absorber 1 [The following structure] 0.007 part ・ Sodium tetraphenylborate [The following structure] 0.040 part ・ Klucel 99M ^{* 6} 0.007 part ・ Byk 336 ^{* 7} 0.015 part ・ n-propanol 7.470 copies, water 1.868 copies

* 1: The polymerizable compound 1 is dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.).
* 2: Graft copolymer 1 is a polymer grafted with poly (oxy-1,2-ethandyl), α- (2-methyl-1-oxo-2-propenyl) -ω-methoxy-, and ethenylbenzene. , This is a 25% dispersion in a solvent of 80% n-propanol / 20% water.
* 3: Graft copolymer 2 is a polymer particle of a graft copolymer of poly (ethylene glycol) methyl ether methacrylate / styrene / acrylonitrile = 10: 9: 81, and has a mass ratio of n-propanol / water of 80/20. It is a dispersion containing 24% by mass in the solvent. The volume average particle size of the polymer particles is 193 nm.
* 4: Mercapto-3-triazole is 3-mercapto-1H, 2,4-triazole available from PCAS (France).
* 5: Irgacure 250 is a 75% propylene carbonate solution of iodonium (4-methylphenyl) [4- (2-methylpropyl) phenyl] hexafluorophosphate available from Ciba Specialty Chemicals.
* 6: Klucel 99M is a 1% aqueous solution of a hydroxypropyl cellulose thickener available from Hercules.
* 7: Byk 336 is a 25% xylene / methoxypropyl acetate solution of a modified dimethylpolysiloxane copolymer available from Byk Chemie.

<Formation of specific compound-containing layer (1)>
A specific compound-containing layer coating solution (1) having the following composition is bar-coated on the image recording layer and dried in an oven at 120 ° C. for 60 seconds to form a specific compound-containing layer having a dry coating amount of 0.15 g / m ² . bottom.

<Specific compound-containing layer coating liquid (1)>
-Inorganic layered compound dispersion (1) [below] 1.5 parts-Polyvinyl alcohol (CKS50, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., sulfonic acid modification, saponification degree 99 mol% or more, polymerization degree 300) 6% by mass aqueous solution
0.55 parts, polyvinyl alcohol (PVA-405, manufactured by Kuraray Co., Ltd.,
Saponification degree 81.5 mol%, polymerization degree 500) 6% by mass aqueous solution
0.03 parts ・ Surfactant (polyoxyethylene lauryl ether, Emarex 710, manufactured by Nippon Emulsion Co., Ltd.) 1% by mass aqueous solution 0.86 parts ・ Specific compound [Compounds shown in Table 1] [Table 1 Amount]
・ 6.0 copies of ion-exchanged water

The preparation method of the inorganic layered compound dispersion liquid (1) used for the specific compound-containing layer coating liquid (1) is shown below.
<Preparation of Inorganic Layered Compound Dispersion Liquid (1)>
6.4 g of synthetic mica (Somasif ME-100, manufactured by CO-OP CHEMICAL CO., LTD.) Was added to 193.6 g of ion-exchanged water, and the mixture was dispersed using a homogenizer until the average particle size (laser scattering method) became 3 μm. The aspect ratio of the obtained dispersed particles was 100 or more.

<Formation of specific compound-containing layer (2)>
A specific compound-containing layer coating solution (2) having the following composition is bar-coated on the image recording layer, dried in an oven at 120 ° C. for 60 seconds, and contains a specific compound having a dry coating amount of 0.06 g / m ² . Formed a layer.

<Specific compound-containing layer coating liquid (2)>
-Surfactant (polyoxyethylene lauryl ether, Emarex 710, manufactured by Nippon Emulsion Co., Ltd.) 0.86 parts by mass% aqueous solution-Specific compound [Compounds shown in Table 1] [Amounts shown in Table 1]
・ 6.0 copies of ion-exchanged water

[Preparation of lithographic printing plate original plate]
The lithographic printing plate original plate was prepared by combining the support, the image recording layer, and the specific compound-containing layer as shown in Table 1. The specific compound-containing layer was formed by using the specific compound-containing layer coating liquid (1) in Examples 1 to 24 and Comparative Examples 1 and 2, and the specific compound-containing layer coating liquid (2) in Example 25.
The lithographic printing plate original plate of Comparative Example 2 was produced as follows. After applying the undercoat layer coating solution (1) having the following composition on the support (1) so that the dry coating amount is 20 mg / m ² , an aqueous solution of sodium dihydrogen phosphate as a specific compound is applied as a specific compound without drying. , 2NL04 manufactured by Hyojin Kikai Co., Ltd. was used as the coating device. That is, by fixing the clearance of the coating device to 0.3 mm and adjusting the amount of liquid to be sent, the content of the specific compound is specified at a position of 3 cm from the end with a width of 6 mm so that the content of the specific compound becomes 150 mg / m ² . An aqueous solution of the compound was applied. Then, it was dried in an oven at 100 ° C. for 60 seconds. An image recording layer and a specific compound-containing layer were combined and formed on the undercoat layer as shown in Table 1 to prepare a lithographic printing plate original plate.

<Undercoat layer coating liquid (1)>
-Compound for undercoat layer (1) [Structure below] 0.18 g
・ Hydroxyethyliminodiacetic acid 0.05g
-Surfactant (Emarex 710, manufactured by Nippon Emulsion Co., Ltd.)
0.03g
・ Water 28.0g

[Cutting of lithographic printing plate original]
The original plate for flat plate printing is cut by adjusting the gap between the upper cutting blade and the lower cutting blade, the biting amount and the cutting edge angle using a rotary blade as shown in FIG. 2, and the sagging amount is 50 μm and the sagging width is 150 μm. The sagging shape to have was formed. The lithographic printing plate original plate of Comparative Example 2 was cut at the center of the region coated with the aqueous solution of the specific compound having a width of 6 mm to obtain a lithographic printing plate original plate having a specific compound coating region having a width of 3 mm at the end. rice field.
When the area ratio of cracks existing on the surface of the anodic oxide film was calculated according to the method described above, the support (1) was 13%, the support (2) was 8%, and the supports (3) and ( 4) was 6%.

[Evaluation of lithographic printing plate original]
Regarding the lithographic printing plate original plate, the edge stain prevention property, the image forming property of the edge portion, and the on-machine developability after manufacturing and forced aging were evaluated as follows. The evaluation results are shown in Table 1.

<Prevention of edge stains after manufacturing>
The lithographic printing plate original plate was exposed on a Luxcel PLATESETTER T-6000III manufactured by Fujifilm Corporation equipped with an infrared semiconductor laser under the conditions of an outer surface drum rotation speed of 1,000 rpm, a laser output of 70%, and a resolution of 2,000 dpi. As the exposed image, a chart including a solid image, 50% halftone dots, and a non-image portion was used.
The image-exposed flat plate printing plate original plate is attached to an offset rotary printing machine manufactured by Tokyo Kikai Seisakusho Co., Ltd., and used as printing ink for newspapers, Soybee KKST-S (red) manufactured by Inktech Co., Ltd. Using Toyo ALKY manufactured by Ink Co., Ltd., print on newspaper at a speed of 100,000 sheets / hour, and print the 2,000th sheet with a water scale 1.3 times from the water scale for eliminating background stains. Sampling was performed, the degree of linear stain caused by the edge of the flat plate printing plate original plate was observed, and the evaluation was made according to the following criteria. 5, 4, and 3 are acceptable levels.
5: No linear stains are observed.
4: Discontinuous linear stains are slightly recognized.
3: Continuous linear stains are slightly recognized.
2: Discontinuous and clear linear stains are observed.
1: Continuous and clear linear stains are observed.

<Prevention of edge stains after forced aging>
After the lithographic printing plate precursor was stored in a moist heat environment with a temperature of 60 ° C. and a humidity of 60% for 2 days, the edge stain prevention property after forced aging was evaluated in the same manner as the edge stain prevention property after the above production. Storage for 2 days in a moist heat environment with a temperature of 60 ° C. / humidity of 60% corresponds to 10 months of natural time (temperature 25 ° C./humidity 50%).

<Image formation at the edges>
The flat plate printing plate original plate exposed in the same manner as the above evaluation of edge stain prevention was attached to an offset rotary printing machine manufactured by Tokyo Kikai Seisakusho Co., Ltd., and used as a printing ink for newspapers by Inktech Co., Ltd. Soyby KKST- S (red), using Eco Seven N-1 manufactured by Sakata Inks Co., Ltd. as dampening water, prints on newspaper at a speed of 100,000 sheets / hour, and prints at a speed of 5,000, 10,000, 50,000, 100, The 000nd printed matter was sampled, and the image formability in the region from the edge of the flat plate printing plate original plate to 1 mm inward was evaluated according to the following criteria. 5, 4, and 3 are acceptable levels.
5: The image can be printed even after printing 100,000 sheets.
The image can be printed even after printing 4: 50,000 sheets.
The image can be printed even after printing 3: 10,000 sheets.
The image can be printed even after printing 2: 5,000 sheets.
No image can be printed after printing 1: 5,000 sheets.

<In-machine developability>
The flat plate printing plate original plate exposed in the same manner as the above evaluation of edge stain prevention was attached to an offset rotary printing machine manufactured by Tokyo Kikai Seisakusho Co., Ltd., and used as a printing ink for newspapers, Soiby KKST- S (red) and Eco Seven N-1 manufactured by Sakata Inks Co., Ltd. were used as dampening water, and printing was performed on newspaper at a speed of 100,000 sheets / hour. In the area from the edge of the lithographic printing plate original to 50 mm inward, it is necessary to complete the on-machine development of the unexposed part of the image recording layer on the printing machine and to prevent the ink from being transferred to the non-image part. The number of sheets of newspaper developed was measured as the number of sheets developed on the machine, and evaluated according to the following criteria. 5, 4, 3 and 2 are acceptable levels.
5: The number of sheets developed on the machine is 25 or less.
4: The number of machine-developed sheets is 26 to 30.
3: The number of machine-developed sheets is 31 to 35.
2: The number of sheets developed on the machine is 36 to 40.
1: The number of machine-developed sheets is 41 or more.

From the results shown in Table 1, a lithographic printing plate original plate containing substantially the same amount of the specific compound according to the present invention in the plane of the specific compound-containing layer provided on the image recording layer has an image formation at the end. It can be seen that it exhibits good edge stain prevention even after long-term storage without deteriorating properties such as properties and on-machine developability. On the other hand, in the lithographic printing plate original plate of Comparative Example 1 containing no specific compound, clear linear edge stains are generated. Further, in the lithographic printing plate original plate of Comparative Example 2 having a hydrophilization treatment region at the end portion of the lithographic printing plate original plate as in the examples of JP-A-2017-19206, the image formability of the end portion is deteriorated. You can see that there is.

[Examples 26 to 27 and Comparative Examples 3 to 4]
<Formation of the first polymer layer (1)>
The undercoat layer coating liquid (1) having the above composition was bar-coated on the support (1) and then dried in an oven at 100 ° C. for 60 seconds to form a first polymer layer having a dry coating amount of 20 mg / m ² .

<Formation of the second polymer layer (1)>
After the coating liquid (1) for the second polymer layer having the following composition is bar-coated on the first polymer layer (1) (undercoat layer), it is dried in an oven at 100 ° C. for 60 seconds, and the dry coating amount is 0.5 g / m. A ^second polymer layer of 2 was formed.

(Coating liquid for the second polymer layer (1))
・ Polyvinylpyrrolidone K30 (Fuji Film Wako Pure Chemical Industries, Ltd.)
0.500 parts ・ Fluorosurfactant (1) (Structure) 0.004 parts ・ 1-methoxy-2-propanol 12.101 parts ・ Methanol 1.345 parts ・ Pure water 0.036 parts

<Formation of specific compound-containing layer (3)>
A specific compound-containing layer coating solution (3) having the following composition is bar-coated on the second polymer layer and dried in an oven at 120 ° C. for 60 seconds to obtain a specific compound-containing layer having a dry coating amount of 0.15 g / m ² . Formed.

<Specific compound-containing layer coating liquid (3)>
-Inorganic layered compound dispersion (1) [above] 1.5 parts-Polyvinyl alcohol (CKS50, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., sulfonic acid modification, saponification degree 99 mol% or more, polymerization degree 300) 6% by mass aqueous solution
0.55 parts, polyvinyl alcohol (PVA-405, manufactured by Kuraray Co., Ltd.,
Saponification degree 81.5 mol%, polymerization degree 500) 6% by mass aqueous solution
0.03 parts ・ Surfactant (polyoxyethylene lauryl ether, Emarex 710, manufactured by Nippon Emulsion Co., Ltd.) 1% by mass aqueous solution 0.86 parts ・ Specific compound [Compounds shown in Table 2] [Table 2 Amount]
・ 6.0 copies of ion-exchanged water

[Making a lithographic printing plate dummy plate]
The support, the first polymer layer, the second polymer layer, and the specific compound-containing layer were combined as shown in Table 2 to prepare a lithographic printing plate dummy plate. The specific compound-containing layer was formed by using the specific compound-containing layer coating liquid (3) in Examples 26 to 27 and Comparative Examples 3 to 4.
The planographic printing plate dummy plate of Example 27 was produced as follows. The undercoat layer coating liquid (1) having the above composition was bar-coated on the support (1) and then dried in an oven at 100 ° C. for 60 seconds to form a first polymer layer having a dry coating amount of 20 mg / m ² . The specific compound-containing layer coating liquid (3) having the above composition is bar-coated on the first polymer layer and dried in an oven at 120 ° C. for 60 seconds to obtain a specific compound-containing layer having a dry coating amount of 0.15 g / m ² . It was formed and a lithographic printing plate dummy plate was produced.
The planographic printing plate dummy plate of Comparative Example 4 was produced as follows. The undercoat layer coating liquid (1) having the above composition was bar-coated on the support (1) and then dried in an oven at 100 ° C. for 60 seconds to form a first polymer layer having a dry coating amount of 20 mg / m ² . The specific compound-containing layer coating liquid (3) having the above composition is bar-coated on the first polymer layer and dried in an oven at 120 ° C. for 60 seconds to obtain a specific compound-containing layer having a dry coating amount of 0.15 g / m ² . It was formed and a lithographic printing plate dummy plate was created.

[Cut of lithographic printing plate dummy plate]
The flat plate printing plate dummy plate is cut by adjusting the gap between the upper cutting blade and the lower cutting blade, the biting amount and the cutting edge angle using a rotary blade as shown in FIG. 2, and the sagging amount is 50 μm and the sagging width is 150 μm. Formed a sagging shape with.
When the area ratio of the cracks existing on the surface of the anodic oxide film was calculated according to the method described above, the support (1) was 13%.

[Evaluation of lithographic printing plate dummy plate]
Regarding the lithographic printing plate dummy plate, the edge stain prevention property and the on-machine developability after manufacturing and after forced aging were evaluated as follows. The evaluation results are shown in Table 2.

<Prevention of edge stains after manufacturing>
The flat plate printing plate dummy plate is attached to an offset rotary printing machine manufactured by Tokyo Kikai Seisakusho Co., Ltd., and used as printing ink for newspapers, Soybee KKST-S (red) manufactured by Inktech Co., Ltd., and as dampening water, Toyo Ink ( Using Toyo ALKY Co., Ltd., print on newspaper at a speed of 100,000 sheets / hour, and sample the 2,000th printed matter with a water scale 1.3 times the water scale for removing ground stains. , The degree of linear stain caused by the edge of the flat plate printing plate dummy plate was observed and evaluated according to the following criteria. 5, 4, and 3 are acceptable levels.
5: No linear stains are observed.
4: Discontinuous linear stains are slightly recognized.
3: Continuous linear stains are slightly recognized.
2: Discontinuous and clear linear stains are observed.
1: Continuous and clear linear stains are observed.

<Prevention of edge stains after forced aging>
After the planographic printing plate dummy plate was stored in a moist heat environment with a temperature of 60 ° C. and a humidity of 60% for 2 days, the edge stain prevention property after forced aging was evaluated in the same manner as the edge stain prevention property after the above production. Storage for 2 days in a moist heat environment with a temperature of 60 ° C. / humidity of 60% corresponds to 10 months of natural time (temperature 25 ° C./humidity 50%).

<In-machine developability>
The flat plate printing plate dummy plate is attached to an offset rotary printing machine manufactured by Tokyo Kikai Seisakusho Co., Ltd., soybee KKST-S (red) manufactured by Inktech Co., Ltd. as printing ink for newspapers, and Sakata Inks Co., Ltd. as dampening water. Using Eco Seven N-1, printing was performed on newspaper at a speed of 100,000 sheets / hour. In the area from the edge of the planographic printing plate dummy plate to the inside up to 50 mm, the number of newspapers required until the on-machine development is completed and the ink is not transferred is measured as the number of on-machine developments, and is as follows. Evaluated by criteria. 5, 4, 3 and 2 are acceptable levels.
5: The number of sheets developed on the machine is 25 or less.
4: The number of machine-developed sheets is 26 to 30.
3: The number of machine-developed sheets is 31 to 35.
2: The number of sheets developed on the machine is 36 to 40.
1: The number of machine-developed sheets is 41 or more.

From the results shown in Table 2, a lithographic printing plate dummy plate containing substantially the same amount of the specific compound according to the present invention in the plane of the specific compound-containing layer provided on the polymer layer is in-machine developable. It can be seen that good edge stain prevention is exhibited even after long-term storage without deteriorating the characteristics. On the other hand, in the lithographic printing plate dummy plates of Comparative Examples 3 and 4 containing no specific compound, clear linear edge stains are generated.

[Examples 28 to 29 and Comparative Examples 5 to 6]
[Making a lithographic printing plate dummy plate]
A planographic printing plate dummy plate of Example 28 was prepared in the same manner as in Example 26 except that the support (1) was changed to the support (4).
A planographic printing plate dummy plate of Example 29 was prepared in the same manner as in Example 27 except that the support (1) was changed to the support (4).
A planographic printing plate dummy plate of Comparative Example 5 was prepared in the same manner as in Comparative Example 3 except that the support (1) was changed to the support (4).
A planographic printing plate dummy plate of Comparative Example 6 was prepared in the same manner as in Comparative Example 4 except that the support (1) was changed to the support (4).

[Cut of lithographic printing plate dummy plate]
The flat plate printing plate dummy plate is cut by adjusting the gap between the upper cutting blade and the lower cutting blade, the biting amount and the cutting edge angle using a rotary blade as shown in FIG. 2, and the sagging amount is 50 μm and the sagging width is 150 μm. Formed a sagging shape with.
When the area ratio of the cracks existing on the surface of the anodic oxide film was calculated according to the method described above, the support (4) was 6%.

[Examples 30 to 31]
[Preparation of lithographic printing plate original plate]
A planographic printing plate original plate of Example 30 was prepared in the same manner as in Example 3 except that the specific compound in the specific compound-containing layer was removed (that is, the specific compound in the specific compound-containing layer coating liquid (1) was excluded). bottom.
A planographic printing plate original plate of Example 31 was prepared in the same manner as in Example 23 except that the specific compound in the specific compound-containing layer was removed (that is, the specific compound in the specific compound-containing layer coating liquid (1) was excluded). bottom.

[Cutting of lithographic printing plate original]
The original plate for flat plate printing is cut by adjusting the gap between the upper cutting blade and the lower cutting blade, the biting amount and the cutting edge angle using a rotary blade as shown in FIG. 2, and the sagging amount is 50 μm and the sagging width is 150 μm. The sagging shape to have was formed.
When the area ratio of the cracks existing on the surface of the anodic oxide film was calculated according to the method described above, the support (1) was 13% and the support (4) was 6%.

[Examples 32 to 35 and Comparative Examples 7 to 10]
The lithographic printing plate original plates obtained in Examples 30 and 31 and the lithographic printing plate dummy plates obtained in Examples 26 to 29 and Comparative Examples 3 to 6 were combined as shown in Table 3 below, and the following evaluation was performed. rice field.

<Prevention of edge stains on lithographic printing plate original plate and lithographic printing plate dummy plate>
The lithographic printing plate original plate was exposed on a Luxcel PLATESETTER T-6000III manufactured by Fujifilm Corporation equipped with an infrared semiconductor laser under the conditions of an outer surface drum rotation speed of 1,000 rpm, a laser output of 70%, and a resolution of 2,000 dpi. As the exposed image, a chart including a solid image, 50% halftone dots, and a non-image portion was used.
One unexposed flat plate printing plate original plate and one unexposed flat plate printing plate dummy plate were mounted on the same plate cylinder of an offset rotary printing machine manufactured by Tokyo Kikai Seisakusho Co., Ltd., and used as printing ink for newspapers. Soybee KKST-S (red) manufactured by Inktech Co., Ltd. and Toyo ALKY manufactured by Toyo Ink Co., Ltd. are used as dampening water to print on newspaper at a speed of 100,000 sheets / hour to eliminate background stains. The 2,000th printed matter is sampled with a water scale 1.3 times from the water scale, and linear stains caused by the edges of the adjacent flat plate printing plate original plate and the edges of the flat plate printing plate dummy plate are found. The degree was observed and evaluated according to the following criteria. 5, 4, and 3 are acceptable levels.
5: No linear stains are observed.
4: Discontinuous linear stains are slightly recognized.
3: Continuous linear stains are slightly recognized.
2: Discontinuous and clear linear stains are observed.
1: Continuous and clear linear stains are observed.

From the results shown in Table 3, when a lithographic printing plate dummy plate containing substantially the same amount of the specific compound according to the present invention in the plane of the specific compound-containing layer provided on the polymer layer was used, a lithographic printing plate was used. It can be seen that good edge stain prevention is obtained for the printing plate dummy plate, and good edge stain prevention is also obtained for the lithographic printing plate original plate.

According to the present invention, an on-machine developing type lithographic printing plate original plate and a machine that show good edge stain prevention even after long-term storage without deteriorating characteristics such as image formability and on-machine developability of edges. It is possible to provide a method for producing a lithographic printing plate using a top-developing lithographic printing plate original plate.
Further, according to the present invention, there is provided an on-machine development type lithographic printing plate, an original plate dummy plate, and a printing method, which show good edge stain prevention even after long-term storage without deteriorating characteristics such as on-machine developability. can do.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application filed on January 31, 2018 (Japanese Patent Application No. 2018-15603), the contents of which are incorporated herein by reference.

1 Flat plate printing plate original plate 1a Specific compound-containing layer surface 1b Support surface 1c End surface 2 Dripping X Dripping amount Y Dripping width B Boundary between image recording layer surface and support 10 Cutting blade 10a Upper cutting blade 10b Upper cutting blade 11 Rotating shaft 20 Cutting blade 20a Lower cutting blade 20b Lower cutting blade 21 Rotating shaft 30 Flat plate printing plate Original plate

Claims (21)

An on-machine development type lithographic printing plate original plate having an image recording layer on an aluminum support having an anodic oxide film, the lithographic printing plate original plate has a sagging shape at an end and is supported on the image recording layer. In-plane of a layer containing a compound having body-adsorbability (excluding ethylenediamine tetraacetic acid tetrasodium tetrahydrate) and having a content of the compound containing the compound having support adsorbability. Is substantially the same in
The compound has a molecular weight of 1,000 or less and has a molecular weight of 1,000 or less.
An on-machine developing type lithographic printing plate original plate in which the content of the compound having the support-adsorbing property in the layer containing the compound having the support-adsorbing property is 20 mg / m ² or more. The machine-developed lithographic printing plate original plate according to claim 1, wherein the compound represented by the formula K1 or the formula K2 is excluded from the compound having the support-adsorbing property.

In K1 and K2, R ^K1 , R ^K2 , R ^K4 , R ^K5 , R ^K6 And R ^K7 Each independently represents a single bond or a linear alkylene group having 1 to 3 carbon atoms, and R ^K3 Represents a (1 + m) valent organic group, R ^K8 Represents a (2 + n) -valent organic group, X independently represents (-CH <) or (-N <), and Y ^K1 ~ Y ^K6 Each independently represents a monovalent group represented by -C (= O) OM, A represents a carboxy group, m represents an integer of 0 to 2, and n represents an integer of 0 to 4. M independently represents a hydrogen atom, a metal atom, or an ammonium group. The machine-developed lithographic printing plate original plate according to claim 1 or 2 , wherein the content of the compound having the support-adsorbing property in the layer containing the compound having the support-adsorbing property is 20 to 150 mg / m ² . The machine-developed lithographic printing plate original plate according to any one of claims 1 to 3, wherein the layer containing the compound having the support-adsorbing property further contains a surfactant. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 4 , wherein the layer containing the compound having the support-adsorbing property further contains a water-soluble polymer. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 5 , wherein the compound is an oxo acid or a salt thereof. The compounds are phosphoric acid, polyphosphoric acid, metaphosphoric acid, ammonium primary phosphate, ammonium secondary phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, potassium primary phosphate, potassium secondary phosphate, tripolyline. Sodium acid, potassium pyrophosphate, sodium hexametaphosphate, phosphinic acid, ethylphosphonic acid, propylphosphonic acid, i-propylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, dodecylphosphonic acid, octadecylphosphonic acid, 2- Hydroxyethylphosphonic acid and its sodium or potassium salt, alkylphosphonic acid monoalkyl ester and their sodium or potassium salt, alkylene diphosphonic acid and their sodium or potassium salt, hydroxyethylidene diphosphonic acid, polyvinylphosphonic acid , P-toluenesulfonic acid, sodium p-toluenesulfonate, sulfophthalic acid, or citric acid. The machine-developed flat plate printing plate original plate according to any one of claims 1 to 5 . The machine-developed lithographic printing plate original plate according to any one of claims 1 to 7 , wherein the compound is a compound represented by the following formula 1.

In formula 1, n represents an integer of 2 to 10, and R1, R2, and R3 independently represent a hydrogen atom, an alkali metal salt, an alkaline earth metal salt, an ammonium salt, an alkyl group, or an alkylene oxide group. .. The machine-developed flat plate printing plate original plate according to any one of claims 1 to 8 , wherein the compound is phosphoric acid, polyphosphoric acid, phosphonic acid or phosphinic acid or a salt thereof. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 9 , wherein the sagging shape has a sagging amount X of 25 to 150 μm and a sagging width Y of 70 to 300 μm. The machine-developed lithographic printing plate original plate according to claim 10 , wherein the area ratio of cracks existing on the surface of the anodic oxide film in the region corresponding to the sagging width Y of the lithographic printing plate original plate is 20% or less. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 11 , wherein the image recording layer contains polymer particles. The machine-developed flat plate printing plate original plate according to claim 12 , wherein the polymer particles are polymer particles containing a monomer unit derived from a styrene compound and / or a monomer unit derived from a (meth) acrylonitrile compound. The step of image-exposing the machine-developed lithographic printing plate original according to any one of claims 1 to 13 with an infrared laser, and at least one selected from printing ink and dampening water on the printing machine. A method for producing a lithographic printing plate, which comprises a step of removing an unexposed portion of an image recording layer. An on-machine development type lithographic printing plate dummy plate having a polymer layer on an aluminum support having an anodic oxide film, the lithographic printing plate dummy plate has a sagging shape at an end and is supported on the polymer layer. It has a layer containing a compound having body adsorptivity, and the content of the compound is substantially the same in the plane of the layer containing the compound having the support adsorbability.
The compound has a molecular weight of 1,000 or less and has a molecular weight of 1,000 or less.
The on-board development type flat plate printing plate dummy plate (provided that the aluminum support and the aluminum support) have a content of the compound having the support-adsorbing property of 20 mg / m ² or more in the layer containing the compound having the support-adsorbing property. A flat plate printing plate dummy plate having a first hydrophilic layer directly formed on the aluminum support and a second hydrophilic layer directly formed on the first hydrophilic layer in this order. The first hydrophilic layer and at least one of the second hydrophilic layers contain a colorant having an absorption maximum at 350 to 800 nm, and the first hydrophilic layer is a support-adsorbing group and a hydrophilic group. (Excluding the flat plate printing plate dummy plate) containing a polymer compound having and . The machine-developed planographic printing plate dummy plate according to claim 15 , wherein the content of the compound having the support-adsorbing property in the layer containing the compound having the support-adsorbing property is 20 to 150 mg / m ² . The compounds are phosphoric acid, polyphosphoric acid, metaphosphoric acid, ammonium primary phosphate, ammonium secondary phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, potassium primary phosphate, potassium secondary phosphate, tripolyline. Sodium acid, potassium pyrophosphate, sodium hexametaphosphate, phosphinic acid, ethylphosphonic acid, propylphosphonic acid, i-propylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, dodecylphosphonic acid, octadecylphosphonic acid, 2- Hydroxyethylphosphonic acid and its sodium or potassium salt, alkylphosphonic acid monoalkyl ester and their sodium or potassium salt, alkylene diphosphonic acid and their sodium or potassium salt, hydroxyethylidene diphosphonic acid, polyvinylphosphonic acid , P-toluenesulfonic acid, sodium p-toluenesulfonate, sulfophthalic acid, or citric acid. The machine-developed flat plate printing plate dummy plate according to claim 15 or 16 . The machine-developed flat plate printing plate dummy plate according to any one of claims 15 to 17 , wherein the compound is phosphoric acid, polyphosphoric acid, phosphoric acid, phosphinic acid, or a salt thereof. The step of on-machine developing the on-machine development type lithographic printing plate dummy plate according to any one of claims 15 to 18 and the on-machine developing type lithographic printing plate original plate having an image recording layer on an aluminum support. Printing method including. The printing method according to claim 19 , wherein the image recording layer contains polymer particles. The printing method according to claim 20 , wherein the polymer particles are copolymer particles containing styrene and acrylonitrile.

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