WO2021171862A1

WO2021171862A1 - Lithographic printing plate original plate, lithographic printing plate manufacturing method, and lithographic printing method

Info

Publication number: WO2021171862A1
Application number: PCT/JP2021/002475
Authority: WO
Inventors: 加奈栢木; 侑也宮川; 駿平渡邉
Original assignee: 富士フイルム株式会社
Priority date: 2020-02-28
Filing date: 2021-01-25
Publication date: 2021-09-02
Also published as: JP7464691B2; JPWO2021171862A1

Abstract

This lithographic printing plate original plate has, on a support body, a layer that contains a color developing compound having a group cleaved by heat or infrared exposure, the lithographic printing plate original plate having, at end portions of at least two opposing sides in the support body, a sagging shape exhibiting a sagging amount X of 25-150 μm and a sagging width Y of 70-300 μm. This lithographic printing plate manufacturing method and this lithographic printing method use said lithographic printing plate original plate.

Description

Planographic printing plate Original plate, lithographic printing plate manufacturing method, and lithographic printing method

This disclosure relates to a lithographic printing plate original plate, a method for producing a lithographic printing plate, and a lithographic printing method.

Generally, a lithographic printing plate consists of a lipophilic image part that receives ink in the printing process and a hydrophilic non-image part that receives dampening water. In flat plate printing, utilizing the property that water and oil-based ink repel each other, the oil-based image part of the flat plate printing plate is the ink receiving part, and the hydrophilic non-image part is the dampening water receiving part (ink non-receptive part). ), This is a method in which a difference in the adhesiveness of ink is generated on the surface of a 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 the plate making process of 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 original plate 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 liquids associated with wet processing such as development processing have been highlighted in the plate making of lithographic printing plate original plates. 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 original plate is exposed to an image, then attached to the printing machine as it is without performing the conventional wet development processing, 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 like 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. As a result, linear stains (edge stains) occur, which significantly impairs the commercial value of printed matter.

Examples of the conventional planographic printing plate original plate include those described in Patent Documents 1 to 3.
Patent Document 1 describes an on-machine development type lithographic printing plate original plate having an image recording layer on an aluminum support having an anodized film, and the lithographic printing plate original plate has a sagging shape at an end, and the above image. On the machine, the 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 development type lithographic printing plate original plate is described.

Patent Document 2 describes a lithographic printing plate original plate having an image recording layer on a support containing a color-developing composition containing a compound represented by the following formula (1).

In Formula (1), ^{R 1} represents a group which cleaves the ^R 1 -O bond by heat or infrared exposure. R ² and R ³ may independently represent a hydrogen atom or an alkyl group, or R ² and R ³ may be linked to each other to form a ring. Ar ¹ and Ar ² each independently represent a group forming a benzene ring or a naphthalene ring. Y ¹ and Y ² independently represent an oxygen atom, a sulfur atom, -NR ^0- or a dialkylmethylene group, respectively. R ⁴ and R ⁵ each independently represent an alkyl group or a group represented by the following formulas (2) to (4). R ⁶ to R ⁹ independently represent a hydrogen atom or an alkyl group. R ⁰ represents a hydrogen atom, an alkyl group or an aryl group. Za represents a counterion for neutralizing the charge. However, the compound represented by the formula (1) has at least one group represented by the formulas (2) to (4) ^{as R 4} or R ⁵ or in R ¹ , Ar ¹ or Ar ^2.

In formulas (2) to (4), R ¹⁰ represents an alkylene group having 2 to 6 carbon atoms. W represents a single bond or an oxygen atom. n1 represents an integer from 1 to 45. R ¹¹ represents an alkyl group having 1 to 12 carbon atoms or -C (= O) -R ¹⁴ . R ¹⁴ represents an alkyl group having 1 to 12 carbon atoms. R ¹² and R ¹³ each independently represent a single bond or an alkylene group having 1 to 12 carbon atoms. M represents a hydrogen atom, a Na atom, a K atom or an onium group.

Patent Document 3 has an image recording layer containing a support, a polymerizable compound and a photopolymerization initiator, and a top layer on the image recording layer, and the thickness of the top layer is 0.1 g / m ^2. From 1.75 g / m ² to 1.75 g / m 2, the top layer comprises an infrared absorber having a thermodissociative group that is converted to a strong electron donating group by heat and / or infrared irradiation. , A flat plate printing plate original plate capable of forming an image by heat and / or infrared irradiation is described.

Patent Document 1: International Publication No. 2019/151447 Patent Document 2: International Publication No. 2017/141882 Patent Document 3: International Publication No. 2019/219560

An object to be solved by one embodiment of the present disclosure is to provide a lithographic printing plate original plate having excellent edge stain suppression properties.
An object to be solved by another embodiment of the present disclosure is to provide a method for producing a lithographic printing plate or a lithographic printing method using the lithographic printing plate original plate.

Means for solving the above problems include the following aspects.
<1> A layer containing a color-developing compound having a group that cleaves by heat or infrared exposure is provided on the support, and the amount of sagging X is 25 μm to 150 μm at at least two opposite ends of the support. A planographic printing plate original plate having a sagging shape with a sagging width Y of 70 μm to 300 μm.
<2> The planographic printing plate original plate according to <1>, wherein the layer containing the color-developing compound is an image recording layer.
<3> An image recording layer is provided on the support.
The planographic printing plate original plate according to <1>, which has a layer containing the color-developing compound on the image recording layer.
<4> The lithographic printing plate original plate according to any one of <1> to <3>, wherein the color-developing compound having a group that cleaves by heat or infrared exposure is a compound represented by the following formula (1). ..

In formula (1), M ¹ is a group that is cleaved by thermal or infrared exposure, R ² and R ³ independently represent a hydrogen atom or an alkyl group, and R ² and R ³ are connected to each other to form a ring. They may be formed, where Ar ¹ and Ar ² each independently represent a group forming a benzene ring or a naphthalene ring, and Y ¹ and Y ² independently represent an oxygen atom, a sulfur atom, -NR ^0- or a dialkyl. R ⁴ and R ⁵ each independently represent an aliphatic hydrocarbon group, R ⁶ to R ⁹ each independently represent a hydrogen atom or an alkyl group, and R ⁰ represents a hydrogen atom, an alkyl group or an alkyl group. Represents an aryl group and Za represents a counterion that neutralizes the charge.

^{<5> At least one group selected from the group consisting of R 4} , R ⁵ , M ¹ , Ar ¹ and Ar ² in the compound represented by the above formula (1) has a hydrophilic group, <4>. The original plate of the lithographic printing plate described in.
<6> The planographic printing plate original plate according to <5>, wherein the hydrophilic group is a group represented by any of the following formulas (2) to (5).

In formulas (2) to (5), R ¹⁰ represents an alkylene group having 2 to 6 carbon atoms, W ¹ represents a single bond or an oxygen atom, n1 represents an integer of 1 to 45, and R ¹¹ represents carbon. Represents an alkyl group of number 1 to 12 or an acyl group of 2 to 12 carbon atoms, and R ¹² and R ¹³ independently represent a single bond or an alkylene group or alkylene oxy group having 1 to 12 carbon atoms, respectively. Represents a hydrogen atom, a Na atom, a K atom or an onium group, and if the charge can be neutralized in the whole compound represented by the formula (1), it does not have to have M, and m1 is 1. It represents 2, 3 or 4, X ¹ represents -O-, -S- or -CH _2- , and the wavy line portion represents the bonding position with other structures.

<7> Either <4> to <6> in which ^{M 1} in the above formula (1) is -NR ^a R ^b , -NR ^c (SO ₂ R ^d ) or -NR ^e (CO ₂ R ^f). The original plate of the planographic printing plate described in one.
However, R ^a and R ^b each independently represent an aryl group, R ^c , ^Re and R ^f independently represent an alkyl group or an aryl group, and R ^d is an alkyl group, an aryl group, or an aryl group. -NR ^d1 represents R ^d2 , and R ^d1 and R ^d2 independently represent a hydrogen atom, an alkyl group or an aryl group.
<8> The planographic printing plate original plate according to any ^one of <4> to <6>, wherein ^{M 1} in the above formula (1) is −OR 1.
However, ^{R 1} is, ^R 1 -O bond by heat or infrared exposure represents a group which cleaves.
<9> The planographic printing plate original plate according to <8>, wherein ^{R 1 is a group represented by the following formula (6).}

In formula (6), R ¹⁵ and R ¹⁶ independently represent a hydrogen atom, an alkyl group or an aryl group, E represents an onium group, and the wavy line portion represents a bond position with an oxygen atom.

<10> The planographic printing plate original plate according to <9>, wherein E in the above formula (6) is a pyridinium group represented by the following formula (7).

Wherein (7), R ¹⁷ represents a halogen atom, an alkyl group, an aryl group, hydroxy group or alkoxy group, if R ¹⁷ there are a plurality, the plurality of R ¹⁷ may be the same or different, or a plurality of R ¹⁷ may be linked to form a ring, n2 represents an integer of 0 to 4, and R ¹⁸ represents an alkyl group, an aryl group, or a group represented by the following formulas (2) to (5). , Zb represent counterions for neutralizing the charge.

<11> The planographic printing plate original plate according to <2> or <3>, wherein the image recording layer has a polymerization initiator and a polymerizable compound.
<12> The planographic printing plate original plate according to <2>, <3> or <11>, wherein the image recording layer has polymer particles.
<13> The planographic printing plate original plate according to any one of <1> to <12>, wherein any layer contains a support-adsorbing compound having a molecular weight of 1,000 or less.
<14> The lithographic printing plate original plate according to any one of <1> to <13>, which has a hydrophilic layer in a region within 1 cm from the end of the surface of the lithographic printing plate original plate on the image recording layer side.
<15> The step of exposing the lithographic printing plate original plate according to any one of <1> to <14> like an image, and at least one selected from the group consisting of printing ink and dampening water on a printing machine. A method for producing a lithographic printing plate, which includes a step of removing an image recording layer in a non-image area by supplying the ink.
<16> A step of exposing the planographic printing plate original plate according to any one of <1> to <14> to an image, and supplying at least one selected from the group consisting of printing ink and dampening water are supplied. A lithographic printing method including a step of removing an image recording layer of a non-image portion on a printing machine to produce a lithographic printing plate, and a step of printing with the obtained lithographic printing plate.

According to one embodiment of the present disclosure, it is possible to provide a lithographic printing plate original plate having excellent edge stain suppression properties.
Further, according to another embodiment of the present disclosure, it is possible to provide a method for producing a lithographic printing plate or a lithographic printing method using the lithographic printing plate original plate.

It is a schematic diagram which shows an example of the cross-sectional shape of the end part of the support of the planographic printing plate original plate cut by the cutting apparatus. It is a conceptual diagram which shows an example of the cutting part of a slitter device. It is a schematic cross-sectional view of one Embodiment of an aluminum support. FIG. 3 is a schematic cross-sectional view of another embodiment of an aluminum support. It is a graph which shows an example of the alternating waveform current waveform diagram used for the electrochemical roughening process in the manufacturing method of an aluminum support. It is a side view which shows an example of the radial type cell in the electrochemical roughening treatment using AC in the manufacturing method of an aluminum support. It is a side view which shows the concept of the brush graining process used for the mechanical roughening process in the manufacturing method of the aluminum support which has an anodic oxide film. It is the schematic of the anodizing treatment apparatus used for the anodizing treatment in the manufacturing method of the aluminum support which has an anodic oxide film.

The contents of the present disclosure will be described in detail below. The description of the constituent elements described below may be based on the representative embodiments of the present disclosure, but the present disclosure is not limited to such embodiments.
In addition, in this specification, "-" indicating a numerical range is used in the meaning that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. .. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
Further, in the notation of a group (atomic group) in the present specification, the notation that does not describe substitution or non-substitution includes those having no substituent as well as those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
In the present specification, "(meth) acrylic" is a term used in a concept that includes both acrylic and methacryl, and "(meth) acryloyl" is a term that is used as a concept that includes both acryloyl and methacryloyl. Is.
In addition, the term "process" in the present specification is not limited to an independent process, and even if it cannot be clearly distinguished from other processes, the term "process" will be used as long as the intended purpose of the process is achieved. included. Further, in the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous.
Further, in the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.
Unless otherwise specified, the weight average molecular weight (Mw) and the number average molecular weight (Mn) in the present disclosure use columns of TSKgel GMHxL, TSKgel G4000HxL, and TSKgel G2000HxL (all trade names manufactured by Toso Co., Ltd.). It is a molecular weight converted by detecting with a solvent THF (tetrahydrofuran) and a differential refractometer by a gel permeation chromatography (GPC) analyzer and using polystyrene as a standard substance.
In the present specification, the term "lithographic printing plate original plate" includes not only a lithographic printing plate original plate but also a discarded plate original plate. Further, the term "lithographic printing plate" includes not only a lithographic printing plate produced by subjecting a lithographic printing plate original plate through operations such as exposure and development as necessary, but also a discarded plate. In the case of a discarded original plate, exposure and development operations are not always necessary. The discard plate is a planographic printing plate original plate to be attached to an unused plate cylinder when printing a part of the paper surface in a single color or two colors in, for example, color newspaper printing.
Hereinafter, the present disclosure will be described in detail.

(Planographic printing plate original)
The lithographic printing plate original plate according to the present disclosure has a layer containing a color-developing compound having a group that cleaves by heat or infrared exposure on the support, and sags at at least two opposite ends of the support. It has a sagging shape in which the amount X is 25 μm to 150 μm and the sagging width Y is 70 μm to 300 μm.
Further, the lithographic printing plate original plate according to the present disclosure is a negative type lithographic printing plate original plate, and can be suitably used as an on-machine development type lithographic printing plate original plate.

It has been found that the lithographic printing plate originals described in Patent Documents 1 to 3, which are the conventional lithographic printing plate originals, do not have sufficient edge stain suppression property.
As a result of diligent studies by the present inventors, it has been found that a lithographic printing plate original plate having excellent edge stain suppression can be provided by adopting the above configuration.
The detailed mechanism for obtaining the above effect is unknown, but it is presumed as follows.
By including a color-developing compound having a group that cleaves by heat or infrared exposure in any layer, the amount of dye required for color development is reduced, so that the amount of hydrophobic material is small and the hydrophilicity is relatively increased. It is estimated that the residual film is suppressed and edge stains are suppressed. Further, it is presumed that by having a specific sagging shape at the end of the support, ink transfer due to contact between the end and the blanket is suppressed, and the edge stain suppressing property is excellent.

Further, the lithographic printing plate original plate according to the present disclosure is a dye produced from the above-mentioned color-developing compound by containing a color-developing compound having a group that cleaves by heat or infrared exposure in any layer. Also excellent in color development over time. Further, the excellent color development property is excellent in the plate inspection property of the exposed lithographic printing plate original plate, and the excellent color development property with time is also excellent in the plate inspection property of the exposed lithographic printing plate original plate after aging.
Further, the lithographic printing plate original plate according to the present disclosure is detailed by containing a color-developing compound having a group that cleaves by heat or infrared exposure in any layer and having a specific sagging shape at the end of the support. The mechanism is unknown, but it is also excellent in on-machine developability and chemical resistance.

The lithographic printing plate original according to the present disclosure has a layer containing a color-developing compound having a group that is cleaved by heat or infrared exposure.
The layer containing the color-developing compound having a group that cleaves by heat or infrared exposure is not particularly limited as long as it is any layer on the support, but at least one selected from the group consisting of an image recording layer and a protective layer. It is preferably a layer. From the viewpoint of on-machine developability and chemical resistance, at least an image recording layer is more preferable. Further, from the viewpoint of color development over time, at least a protective layer is more preferable.
Further, the lithographic printing plate original plate according to the present disclosure preferably has an image recording layer on the support and a layer containing the color-developing compound on the image recording layer from the viewpoint of color development over time. It is more preferable to have an image recording layer on the support and a layer containing the color-developing compound as a protective layer on the image recording layer.
Further, the lithographic printing plate original plate according to the present disclosure preferably contains a support-adsorbing compound having a molecular weight of 1,000 or less in any layer from the viewpoint of edge stain suppression and on-machine developability, and protects the plate. It is more preferable that the protective layer contains at least a support-adsorbing compound having a layer and having a molecular weight of 1,000 or less.

<Dripping shape>
The planographic printing plate original plate according to the present disclosure has a sagging shape in which the sagging amount X is 25 μm to 150 μm and the sagging width Y is 70 μm to 300 μm at at least two opposing side ends of the support.
At the end of the support, the vertical distance X of the curved surface portion bent in the thickness direction of the support from the extension line of the surface of the support on the image recording layer side is "the amount of sagging", and the image of the support of the curved surface portion. The distance Y in the direction parallel to the surface on the recording layer side is called "sag width".
FIG. 1 is an example of the cross-sectional shape of the end portion of the support of the lithographic printing plate original plate cut by the cutting device. As shown in FIG. 1, the vertical distance of the curved surface portion bent in the thickness direction of the support is the sagging amount X, and the distance in the direction parallel to the surface of the support on the image recording layer side of the curved surface portion is the sagging width Y. Is.
Edge stains on the lithographic printing plate original plate occur when the printing ink component driven from the non-image area to the edge is transferred to the blanket, so the amount of sagging at the edge is large to avoid contact between the edge and the blanket. There is a need to.
The amount of sagging X is preferably 35 μm to 150 μm, more preferably 50 μm to 150 μm, and more preferably 50 μm to 100 μm from the viewpoint of edge stain suppression, on-machine developability, and chemical resistance. More preferred.
The sagging width Y is preferably in the range of 90 μm to 300 μm, and more preferably 150 μm to 250 μm, from the viewpoint of edge stain suppression, on-machine developability, and chemical resistance.
The preferable ranges of the sagging amount X and the sagging width Y are not related to the edge shape of the back surface of the support.

The method for forming the sagging shape is not particularly limited, and a known cutting method can be used, but the method of forming by adjusting the gap between the upper cutting blade and the lower cutting blade of the slitter device, the biting amount, and the cutting edge angle. Is preferably mentioned.
FIG. 2 is a conceptual diagram showing a cut portion of the slitter device. A pair of upper and

lower cutting blades

210 and 220 are arranged on the left and right sides of the slitter device. These cutting

blades

210 and 220 are made of disk-shaped round blades, and the

upper cutting blades

210a and 210b are coaxially supported by the rotating shaft 211 and the

lower cutting blades

220a and 220b are coaxially supported by the rotating shaft 221. .. Then, the

upper cutting blades

210a and 210b and the

lower cutting blades

220a and 220b are rotated in opposite directions. The aluminum support 230 is passed between the

upper cutting blades

210a and 210b and the

lower cutting blades

220a and 220b and cut to a predetermined width. More specifically, by adjusting the gap between the upper cutting blade 210a and the lower cutting blade 220a of the cutting portion of the slitter device of FIG. 2 and the gap between the upper cutting blade 210b and the lower cutting blade 220b, It is possible to form a sagging-shaped end portion as shown in FIG.
Further, it is preferable that the above-mentioned cutting is performed at least in the portion having the edge hydrophilic layer described later.

<Image recording layer>
From the viewpoint of on-machine developability and chemical resistance, the image recording layer in the lithographic printing plate original plate according to the present disclosure preferably contains a color-developing compound having a group that is cleaved by heat or infrared exposure.
The image recording layer in the present disclosure is a negative type image recording layer, and is preferably a water-soluble or water-dispersible negative type image recording layer.
Further, the image recording layer in the present disclosure preferably contains a polymerization initiator and a polymerizable compound, and more preferably contains an infrared absorber other than the color-developing compound, a polymerization initiator, and a polymerizable compound. ..
Further, the image recording layer in the present disclosure is preferably an on-board development type image recording layer.
Hereinafter, details of each component contained in the image recording layer will be described.

-A color-developing compound having a group that cleaves when exposed to heat or infrared rays-
The color-developing compound having a group that cleaves by heat or infrared exposure may be a compound having a group that cleaves by directly absorbing heat or infrared rays, and for example, an infrared absorber separately contained may absorb infrared rays. It may be a compound having a group that cleaves due to heat generated by absorption.
The color-developing compound having a group that cleaves by heat or infrared exposure is a compound that develops color by cleaving the group.
In the present disclosure, color development means that coloring or absorption becomes stronger after heating or exposure than before heating or exposure, and the wavelength becomes shorter so that absorption is provided in the visible light region.
Among them, as a color-developing compound having a group that cleaves by heat or infrared exposure, a degradable infrared absorber is used from the viewpoints of edge stain suppression property, color development property, color development property over time, on-machine developability, and chemical resistance. It is preferable that the compound is represented by the following formula (A), and more preferably.

In formula A, ⁺ ^YA1 = has the following structure:

Displayed by one of
^YA2- has the following structure:

Table displayed by one 1, n represents 0, 1, 2 or 3, p and q are each independently 0, 1 or ^{2, R A1} and ^{R A2} are each independently a hydrocarbon group of ^carded, R ^A1, R ^A2, two of ^{R Ad} and ^{R Aa} will contain the necessary atoms to form a cyclic structure ^together, at least one infrared radiation or heat ^{R Ad} or a group that is converted based on a strong electron donor than the R ^Ad by a chemical reaction induced by exposure to, or at least one of R ^Aa is induced by exposure to infrared radiation or heat ^Represents a group that is converted to a group that is a stronger electron donor than the above RAa by a chemical reaction ^{, and the other RAad} and ^RAa independently represent a hydrogen atom, a halogen atom, ^-RAe , ^-ORAf , and -SR. ^Represents a group selected from the group consisting of ^Ag and -NR ^Au R ^{Av, where R Ae} , R ^Af , R ^Ag , R ^Au and R ^Av each independently represent an aliphatic hydrocarbon group, an aryl group or a heteroaryl group. The conversion is a conversion that provides an increase in light absorption between frequencies of 400 nm to 700 nm.
^Further, the hydrocarbon group of ^{R A1} and ^{R A2,} ^{^{^{and, R Ae, R Af, R}}} Ag, the aliphatic hydrocarbon group for ^{R Au} and ^{R Av,} aryl or heteroaryl group is substituted May be good.

^{Further, the RAd} converted by a chemical reaction is preferably any of the groups shown below.

In the above formula, Aa, Ab, respectively Ac and Ad are independently represents 0 or 1, -L ^A - represents a linking ^{group, R A17} is a hydrogen atom, optionally optionally substituted aliphatic hydrocarbon Represents a group, optionally substituted aryl group or optionally substituted heteroaryl group, or ^RA17 and ^RA3 , ^RA17 and ^RA5 , or ^RA17 and ^RA11. together comprise the necessary atoms to form a cyclic ^{structure, R} A4 ^is -OR ^A10, a -NR ^{A13 R A14,} or -CF ^{_3, R A10} also optionally be substituted Represents a good aryl group, an optionally substituted heteroaryl group or an α-branched aliphatic hydrocarbon group, where ^RA13 and ^RA14 are independently substituted with hydrogen atoms and optionally. May represent an aliphatic hydrocarbon group, optionally an optionally substituted aryl group or optionally optionally substituted heteroaryl group, or ^RA13 and ^RA14 together to form a ring structure. ^RA3 contains hydrogen atoms, optionally substituted aliphatic hydrocarbon groups, optionally substituted aryl groups or optionally substituted. a heteroaryl group, ^{or, R A3} is comprises the atoms necessary to form at least one together cyclic structure ^R ^{A10, R A13} and ^{R ^A14,} ^{R A6} is optionally substituted Represents an aliphatic hydrocarbon group which may be optionally, an aryl group which may be optionally substituted, a heteroaryl group which may be optionally substituted, -OR ^A10 , -NR ^A13 ^RA14 or -CF _3. in ^R ^{A10, R A13} and ^{R A14} has the same meaning as in ^{R ^A4,} ^{R A5} is a hydrogen atom, optionally optionally substituted aliphatic hydrocarbon group, which may optionally be substituted aryl group or optionally represents a heteroaryl group which may be substituted, or the atoms necessary to R ^A5 to form at least one together cyclic structure R ^A10, R ^A13 and R ^A14 ^Included , ^{RA11, RA15} and ^RA16 are each independently hydrogen atom, optionally substituted aliphatic hydrocarbon group, optionally substituted aryl group or optionally located. It represents a heteroaryl group that may be ^{substituted, or contains the atoms necessary for RA15} and ^RA16 to form a ring structure together, even ^{if RA12} is optionally substituted. Represents a good aliphatic hydrocarbon group, optionally substituted aryl group or optionally substituted heteroaryl group, where ^RA7 and ^RA9 are independently substituted with hydrogen atoms or optionally. It represents an aliphatic hydrocarbon group ^that, ^'represents, wherein ^{R A8'} ^{R A8} is -COO- or -COOR ^A8 is a hydrogen atom, an alkali metal cation, an ammonium ion or a mono-, - di -, tri - or Represents a tetraalkylammonium ion, ^{where RA18} represents an optionally substituted aryl group, an optionally substituted heteroaryl group or an α-branched aliphatic hydrocarbon group.

Further, as a color-developing compound having a group that cleaves by heat or infrared exposure, the following formula (1) is used from the viewpoint of edge stain suppression property, color development property, color development property over time, on-machine developability, and chemical resistance. It is particularly preferred that it is the compound represented.

The compound represented by the above formula (1) is preferably a compound that is decomposed by heat or infrared exposure to produce a compound having a maximum absorption wavelength in the range of 500 nm to 600 nm.
The color-developing mechanism of the compound represented by the formula (1) is that M ¹ is cleaved by exposure to heat or infrared rays to develop color. For example, when M ¹ ^{is R 1-} O-, which will be described later, as shown below, the cleaved oxygen atom forms a carbonyl group, and a merocyanine dye which is a color former is generated to develop a color. Etc. are estimating.
Further, in order to generate a merocyanine dye ^{, the present inventors presume that it is important that R 1} whose bond is cleaved by heat or infrared exposure and the cyanine dye structure are bonded via oxygen atoms. There is.

^{A preferred embodiment of M 1} in the formula (1) will be described later.
Further, R ² to R ⁹ , R ⁰ , Ar ¹ and Ar ² may have a substituent such as a hydrophilic group described later. Examples of substituents are alkoxy group, aryloxy group, amino group, alkylthio group, arylthio group, halogen atom, carboxy group, carboxylate group, sulfo group, sulfonate group, alkyloxycarbonyl group, aryloxycarbonyl group, phosphonic acid. Examples thereof include a group, a phosphonate group, and a group combining these groups. When the group is an anionic group, it may form a salt, and the counter cation may be a cation having a cyanine dye structure, a proton, a metal cation, onium, or the like.

^{The alkyl group in R 2} to R ⁹ and R ⁰ in the formula (1) is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and an alkyl group having 1 to 10 carbon atoms. More preferred. The alkyl group may be linear, have a branch, or have a ring structure.
Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group. Group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group. Examples include a group and a 2-norbornyl group.
Among these alkyl groups, a methyl group, an ethyl group, a propyl group or a butyl group is particularly preferable.

As ^{the aryl group at R 0,} an aryl group having 6 to 30 carbon atoms is preferable, an aryl group having 6 to 20 carbon atoms is more preferable, and an aryl group having 6 to 12 carbon atoms is further preferable.
Moreover, the above-mentioned aryl group may have a substituent. Examples of substituents are alkyl groups, alkoxy groups, allyloxy groups, amino groups, alkylthio groups, arylthio groups, halogen atoms, carboxy groups, carboxylate groups, sulfo groups, sulfonate groups, alkyloxycarbonyl groups and aryloxycarbonyl groups. , And a group combining these.
Specifically, for example, phenyl group, naphthyl group, p-tolyl group, p-chlorophenyl group, p-fluorophenyl group, p-methoxyphenyl group, p-dimethylaminophenyl group, p-methylthiophenyl group, p- Phenylthiophenyl group and the like can be mentioned.
Among these aryl groups, a phenyl group, a p-methoxyphenyl group, a p-dimethylaminophenyl group and a naphthyl group are preferable.

It is preferable that R ² and R ³ are connected to form a ring.
When R ² and R ³ are connected to form a ring, the number of ring members is preferably 5 or 6-membered ring, and more preferably 6-membered ring.

Y ¹ and Y ² independently represent an oxygen atom, a sulfur atom, an −NR ⁰ − or a dialkyl methylene group, ^{preferably an −NR 0} − or a dialkyl methylene group, and more preferably a dialkyl methylene group.
R ⁰ represents a hydrogen atom, an alkyl group or an aryl group, and is preferably an alkyl group.

R ⁴ and R ⁵ are preferably the same group. When R ⁴ and R ⁵ have an anionic group, it is preferable that R ⁴ and R ⁵ are the same group except that they have an anionic group and have or do not have a counter cation.
Further, R ⁴ and R ⁵ are each independently preferably a linear alkyl group or an alkyl group having a sulfonate group at the terminal, and more preferably a methyl group, an ethyl group or a butyl group having a sulfonate group at the terminal. preferable.
Further, the counter cation of the sulfonate group may be a quaternary ammonium group in the formula (1), an alkali metal cation or an alkaline earth metal cation.
Further, from the viewpoint of improving the water solubility of the compound represented by the formula (1), R ⁴ and R ⁵ are preferably alkyl groups having an anionic structure independently, and have a carboxylate group or a sulfonate group. It is more preferably an alkyl group, and even more preferably an alkyl group in which a sulfonate group is poured at the end.
Further, from the viewpoint of lengthening the maximum absorption wavelength of the compound represented by the formula (1), and from the viewpoint of color development and printing resistance in a slab printing plate, R ⁴ and R ⁵ each have an aromatic ring independently. It is preferably an alkyl group, more preferably an alkyl group having an aromatic ring at the end, a 2-phenylethyl group, a 2-naphthalenylethyl group, or a 2- (9-anthrasenyl) ethyl group. Is particularly preferred.

R ⁶ to R ⁹ independently represent a hydrogen atom or an alkyl group, and are preferably hydrogen atoms.
Ar ¹ and Ar ² each independently represent a group forming a benzene ring or a naphthalene ring. Substituents may be provided on the benzene ring and the naphthalene ring. Substituents include alkyl groups, alkoxy groups, allyloxy groups, amino groups, alkylthio groups, arylthio groups, halogen atoms, carboxy groups, carboxylate groups, sulfo groups, sulfonate groups, alkyloxycarbonyl groups, aryloxycarbonyl groups, and , A group combining these, and the like, but an alkyl group is preferable.
Further, from the viewpoint of lengthening the maximum absorption wavelength of the compound represented by the formula (1), and from the viewpoint of color development and printing resistance in a slab printing plate, Ar ¹ and Ar 2 are independently a naphthalene ring or a naphthalene ring or ^{Ar 2.} , A group forming a benzene ring having an alkyl group or an alkoxy group as a substituent is preferable, and a naphthalene ring or a group forming a benzene ring having an alkoxy group as a substituent is more preferable. It is particularly preferable that the group forms a naphthalene ring or a benzene ring having a methoxy group as a substituent.

Za represents a counterion that neutralizes the charge, and when indicating an anion species, sulfonate ion, carboxylate ion, tetrafluoroborate ion, hexafluorophosphate ion, p-toluenesulfonate ion, perchlorate ion and the like are used. Hexafluoroborate ions are particularly preferred. When indicating a cation species, alkali metal ion, alkaline earth metal ion, ammonium ion, pyridinium ion or sulfonium ion is preferable, sodium ion, potassium ion, ammonium ion, pyridinium ion or sulfonium ion is more preferable, and sodium ion, potassium. Ions or ammonium ions are more preferred.
R ¹ to R ⁹ , R ⁰ , Ar ¹ , Ar ² , Y ¹ and Y ² may have an anionic structure or a cationic structure, and R ¹ to R ⁹ , R ⁰ , Ar ¹ , Ar ² , If ^{all of Y 1} and Y ² are charge-neutral groups, Za is a monovalent counter anion, for example R ¹ to R ⁹ , R ⁰ , Ar ¹ , Ar ² , Y ¹ and If Y ² has two or more anionic structures, Za can also be a counter cation.

In the formula (1), Ar ¹ or Ar ² is preferably a group forming a group represented by the following formula (8).

In the formula (8), R ¹⁹ represents an alkyl group having 1 to 12 carbon atoms or a group represented by the formulas (2) to (4) described later, n3 represents an integer of 1 to 4, and * represents a binding site. Represents.

From the viewpoint of edge stain suppression, on-machine developability, and chemical resistance, it is selected from the group consisting ^{of R 4} , R ⁵ , M ¹ , Ar ¹ and Ar ^{2 in the compound represented by the above formula (1).} At least one group preferably has a hydrophilic group, and at least one group selected from the group consisting of ^{R 4} , R ⁵ and M ¹ ^{more preferably has a hydrophilic group, R 4} and at least one group selected from the group consisting of R ⁵ further preferably has a hydrophilic group, independently R ⁴ and R ⁵ each particularly preferably has a hydrophilic group.

Examples of the hydrophilic group include a polyalkyleneoxy group, an acid group, a salt of an acid group, an alkoxy group, a hydroxy group and the like.
Above all, the hydrophilic group is preferably a group represented by any of the following formulas (2) to (5) from the viewpoint of edge stain suppressing property, on-machine developability, and chemical resistance. , The group represented by either the following formula (2) or the following formula (5) is more preferable, and the group represented by the following formula (2) is particularly preferable.

Specific examples of the alkylene group represented by R ¹⁰ include ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group, n-pentylene group, isopentylene group, n-hexyl group, isohexyl group and the like. , Ethylene group, n-propylene group, isopropylene group, or n-butylene group is preferable, and n-propylene group is particularly preferable.
n1 is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3.
Specific examples of the alkyl group represented by R ¹¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group and neopentyl. Examples thereof include a group, an n-hexyl group, an n-octyl group, an n-dodecyl group and the like, and a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group or a tert-butyl group is preferable, and a methyl group is preferable. A group or an ethyl group is more preferable, and a methyl group is particularly preferable.
Specific examples of the acyl group in R ¹¹ include an acetyl group, a propionyl group, a pivaloyl group and the like. Of these, an acetyl group is preferable.

Specific examples of the group represented by the formula (2) are shown below, but the present disclosure is not limited thereto. In the following structural formula, Me represents a methyl group, Et represents an ethyl group, and * represents a binding site.

^{Specific examples of the alkylene group represented by R 12} or R ¹³ in the formula (3) or the formula (4) include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, and an isobutylene group. , N-pentylene group, isopentylene group, n-hexyl group, isohexyl group, n-octylene group, n-dodecylene group and the like, and ethylene group, n-propylene group, isopropylene group or n-butylene group Preferably, an ethylene group or an n-propylene group is particularly preferable.
When the group represented by the formula (3) or the formula (4) is present in the group represented by Ar ¹ or Ar ² of the ^{compound represented by the formula (1), R 12} or R ¹³ is a single bond. Is preferable.
When the group represented by the formula (3) or the formula (4) ^{is present in M 1 of the} compound represented by the formula (1), or when it is present as a group represented by ^{R 4} or R ^{5, R} ¹² or R ¹³ is preferably an alkylene group.
In equation (4), the two existing Ms may be the same or different.

Specific examples of the onium group represented by M in the formula (3) or the formula (4) include an ammonium group, an iodonium group, a phosphonium group, a sulfonium group and the like.

The ammonium group includes a group represented by the following formula (A1).

In the formula (A1), _Ra to R _d independently represent a hydrogen atom or an aryl group having 20 or less carbon atoms, an alkyl group, an alkenyl group or an alkynyl group. The aryl group, alkyl group, alkenyl group or alkynyl group may have a substituent. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms. Alyloxy group with 6 to 12 carbon atoms, halogen atom, alkylamino group with 1 to 12 carbon atoms, dialkylamino group with 2 to 12 carbon atoms, alkylamide group or arylamide group with 2 to 12 carbon atoms, carbonyl group, carboxy Examples thereof include a group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, a thioaryl group having 6 to 12 carbon atoms, and a hydroxy group. As R _a to R _d , a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 carbon atoms are preferable.

Specific examples of ammonium groups are shown below, but the present disclosure is not limited thereto. In the following structural formula, Me represents a methyl group and Et represents an ethyl group.

The iodonium group includes a group represented by the following formula (B1).

In the formula (B1), _Re to R _f are independently synonymous with _Ra to R _d in the above formula (A1). Examples of preferred _Re to R _f include aryl groups having 6 to 20 carbon atoms.

Specific examples of the iodonium group are shown below, but the present disclosure is not limited thereto.

The phosphonium group includes a group represented by the following formula (C1).

In the formula (C1), R _g to R _j are independently synonymous with _{R a} to R _d in the above formula (A1). Examples of preferable R _g to R _j include aryl groups having 6 to 20 carbon atoms.

Specific examples of the phosphonium group are shown below, but the present disclosure is not limited thereto.

The sulfonium group includes a group represented by the following formula (D1).

In the formula (D1), R _k to R _m are independently synonymous with _{R a} to R _d in the above formula (A1). Preferred examples include an aryl group having 6 to 20 carbon atoms. Examples of preferred _{_R} k ~ _R _m, and an aryl group having 6 to 20 carbon atoms.

Specific examples of the sulfonium group are shown below, but the present disclosure is not limited thereto.

Among the onium groups, an ammonium group is preferable.
When the compound represented by the formula (1) contains an onium group, M may be the above-mentioned onium group.
The onium group may exist as an intracellular onium salt.

Specific examples of the group represented by the formula (3) are shown below, but the present disclosure is not limited thereto. In the following structural formula, Et represents an ethyl group and * represents a binding site.

Specific examples of the group represented by the formula (4) are shown below, but the present disclosure is not limited thereto. In the following structural formula, Et represents an ethyl group and * represents a binding site.

Specific examples of the group represented by the formula (5) are shown below, but the present disclosure is not limited thereto. In the following structural formula, * represents a binding site.

One or more groups represented by any of the formulas (2) to (5) may be present in the compound represented by the formula (1). The upper limit of the number of groups represented by any of the formulas (2) to (5) is preferably 5. The number of groups represented by any of the formulas (2) to (5) is preferably 1 to 5, and more preferably 2 to 3.
The group represented by any of the formulas (2) to (5) may exist as a group represented by ^{R 4} or R ⁵ ^{in the compound represented by the formula (1), or M 1} , It may be present in the group represented by Ar ¹ or Ar ^2.
Groups represented by any of the formulas (2) to (5) is particularly preferably a ^{R 4} and ^{R 5.} Further, the group represented by any of the formulas (2) to (5) is preferably present in the groups represented by ^{Ar 1} and Ar ^2.

^{M 1} in the above formula (1) is ^{-NR a} R ^b , -NR ^c (SO ₂ R ^d ) or -NR ^e (CO ₂ R) from the viewpoint of edge stain suppression property, color development property, and color development property over time. ^f ) is preferable.
However, R ^a and R ^b each independently represent an aryl group, R ^c , ^Re and R ^f independently represent an alkyl group or an aryl group, and R ^d is an alkyl group, an aryl group, or an aryl group. -NR ^d1 represents R ^d2 , and R ^d1 and R ^d2 independently represent a hydrogen atom, an alkyl group or an aryl group.

The alkyl group in R ^c to R ^f , R ^d1 and R ^d2 is preferably an alkyl group having 1 to 20 carbon atoms.
Further, the ^{aryl group in R a} to R ^f , R ^d1 and R ^d2 is preferably an aryl group having 6 to 20 carbon atoms.
The alkyl group and aryl group in R ^a to R ^f , R ^d1 and R ^{d2 may have a substituent.} Examples of substituents are alkoxy group, aryloxy group, amino group, alkylthio group, arylthio group, halogen atom, carboxy group, carboxylate group, sulfo group, sulfonate group, alkyloxycarbonyl group, aryloxycarbonyl group, phosphonic acid. Examples thereof include a group, a phosphonate group, and a group combining these groups. When the group is an anionic group, it may form a salt, and the counter cation may be a cation having a cyanine dye structure, a proton, a metal cation, onium, or the like.

^{Further, M 1} in the above formula (1) is preferably ^{—OR 1} from the viewpoint of edge stain suppression property, color development property, and color development property over time.
However, ^{R 1} is, ^R 1 -O bond by heat or infrared exposure represents a group which cleaves.

From the viewpoint of color development, R ¹ is preferably a group represented by any of the following formulas 1-1 to 1-7, and is represented by any of the following formulas 1-1 to 1-3. It is more preferable that it is a group.

In formulas 1-1 to 1-7, ● represents a bond site with an oxygen atom, and R ²⁰ independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, -OR ²⁴ , and -NR ²⁵ R. ²⁶ or -SR ²⁷ , R ²¹ independently represents a hydrogen atom, an alkyl group or an aryl group, R ²² is an aryl group, -OR ²⁴ , -NR ²⁵ R ²⁶ , -SR ²⁷ , -C (= O) R ²⁸ , -OC (= O) R ²⁸ or halogen atom, R ²³ represents an aryl group, an alkenyl group, an alkoxy group or an onium group, and R ²⁴ to R ²⁷ independently represent a hydrogen atom and an alkyl. Representing a group or aryl group, R ²⁸ independently represents an alkyl group, an aryl group, -OR ²⁴ , -NR ²⁵ R ²⁶ or -SR ²⁷ , and Z ¹ represents a charge-neutralizing counterion.

The preferred embodiment when R ²⁰ , R ²¹ and R ²⁴ to R ²⁸ are alkyl groups is the same as the preferred embodiment of the alkyl group in R ² to R ⁹ and R ⁰ .
The carbon number of the alkenyl group in R ²⁰ and R ²³ is preferably 1 to 30, more preferably 1 to 15, and even more preferably 1 to 10.
The preferred embodiment when R ²⁰ to R ²⁸ are an aryl group is the same as the preferred embodiment of the aryl group in ^{R 0.}

From the viewpoint of color development, R ²⁰ in the formula 1-1 is preferably an alkyl group, an alkenyl group, an aryl group, -OR ²⁴ , -NR ²⁵ R ²⁶ or -SR ²⁷ , and an alkyl group, -OR ²⁴ , -NR ²⁵ R ²⁶ or -SR ²⁷ is more preferred, an alkyl group or -OR ²⁴ is even more preferred, and -OR ²⁴ is particularly preferred.
^{When R 20} in the formula 1-1 is an alkyl group, the alkyl group is preferably an alkyl group having an arylthio group or an alkyloxycarbonyl group at the α-position.
^{When R 20} in the formula 1-1 is −OR ²⁴ , R ²⁴ is preferably an alkyl group, more preferably an alkyl group having 1 to 8 carbon atoms, and an isopropyl group or a t-butyl group. It is more preferable to have a t-butyl group, and it is particularly preferable to have a t-butyl group.

From the viewpoint of color development, R ²¹ in the formula 1-2 is preferably a hydrogen atom.
Further, from the viewpoint of color development, R ²² in the formula 1-2 is preferably -C (= O) OR ²⁴ , -OC (= O) OR ²⁴ or a halogen atom, and is preferably -C (= O) OR. It is more preferably ²⁴ or −OC (= O) OR ^24. ^{When R 22} in the formula 1-2 is -C (= O) OR ²⁴ or -OC (= O) OR ²⁴ , R ²⁴ is preferably an alkyl group.

From the viewpoint of color development, ^{it is preferable that R 21} in the formula 1-3 is independently a hydrogen atom or an alkyl group, and it is more preferable that at least one R ¹¹ in the formula 1-3 is an alkyl group. preferable.
The alkyl group in R ²¹ is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 3 to 10 carbon atoms.
Further, ^{the alkyl group in R 21} is preferably an alkyl group having a branch including a ring structure, more preferably a secondary or tertiary alkyl group, and is an isopropyl group, a cyclopentyl group, a cyclohexyl group, or an alkyl group. , T-butyl group is more preferable.
Further, from the viewpoint of color development, R ²³ in the formula 1-3 is preferably an aryl group, an alkoxy group or an onium group, more preferably a p-dimethylaminophenyl group or a pyridinium group, and is a pyridinium group. It is more preferable to have.
Examples of the onium group in R ²³ include a pyridinium group, an ammonium group, a sulfonium group and the like. The onium group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a sulfo group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and a group combining these groups. However, it is preferably an alkyl group, an aryl group, or a group in which these are combined.
Of these, a pyridinium group is preferable, and an N-alkyl-3-pyridinium group, an N-benzyl-3-pyridinium group, an N- (alkoxypolyalkyleneoxyalkyl) -3-pyridinium group, and an N-alkoxycarbonylmethyl-3-pyridinium group. , N-alkyl-4-pyridinium group, N-benzyl-4-pyridinium group, N- (alkoxypolyalkyleneoxyalkyl) -4-pyridinium group, N-alkoxycarbonylmethyl-4-pyridinium group, or N-alkyl -3,5-dimethyl-4-pyridinium group is more preferable, N-alkyl-3-pyridinium group or N-alkyl-4-pyridinium group is more preferable, N-methyl-3-pyridinium group, N-octyl. A -3-pyridinium group, an N-methyl-4-pyridinium group, or an N-octyl-4-pyridinium group is particularly preferable, and an N-octyl-3-pyridinium group or an N-octyl-4-pyridinium group is the most preferable. preferable.
When R ²³ is a pyridinium group, examples of the counter anion include sulfonate ion, carboxylate ion, tetrafluoroborate ion, hexafluorophosphate ion, p-toluene sulfonate ion, perchlorate ion and the like. -Toluene sulfonate ion and hexafluorophosphate ion are preferable.

From the viewpoint of color development, R ²⁰ in the formula 1-4 is preferably an alkyl group or an aryl group, and more preferably one of the two R ^20s is an alkyl group and the other is an aryl group.
From the viewpoint of color development property, R ²⁰ in the formula 1-5 is preferably an alkyl a group or an aryl group, more preferably an aryl group, more preferably a p- methylphenyl group.
From the viewpoint of color development property, R ²⁰ are each independently of formula 1-6 is preferably an alkyl group or an aryl group, and more preferably a methyl group or a phenyl group.
From the viewpoint of color development, Z ¹ in the formula 1-7 may be any counterion that neutralizes the charge, and the compound as a whole may be contained in the above Za.
Z ¹ is preferably a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a p-toluene sulfonate ion, or a perchlorate ion, and is preferably a p-toluene sulfonate ion or a hexafluoro. More preferably, it is a phosphate ion.

From the viewpoint of color development, R ¹ is more preferably a group represented by the following formula (6).

The ^{alkyl group represented by R 15} or R ¹⁶ is the same as the alkyl group in R ² to R ⁹ and R ⁰ , and the preferred embodiment is also the same as the preferred embodiment of the alkyl group in ^{R 2} to R ⁹ and R ^0. ..
The ^{aryl group represented by R 15} or R ¹⁶ is the same as the aryl group in R ⁰ , and the preferred embodiment is also the same as the preferred embodiment of the aryl group in ^{R 0.}
The onium group represented by E is the same as the onium group in R ²³ , and the preferred embodiment is also the same as the preferred embodiment of the onium group in ^{R 23.}

From the viewpoint of color development, E in the above formula (6) is preferably a pyridinium group represented by the following formula (7).

Wherein (7), R ¹⁷ represents a halogen atom, an alkyl group, an aryl group, hydroxy group or alkoxy group, if R ¹⁷ there are a plurality, the plurality of R ¹⁷ may be the same or different, or a plurality of R ¹⁷ may be linked to form a ring, n2 represents an integer of 0 to 4, and R ¹⁸ represents an alkyl group, an aryl group, or a group represented by the following formulas (2) to (5). , Zb represent a counterion for neutralizing the charge.

In formulas (2) to (5), R ¹⁰ represents an alkylene group having 2 to 6 carbon atoms, W ¹ represents a single bond or an oxygen atom, n1 represents an integer of 1 to 45, and R ¹¹ represents carbon. Represents an alkyl group of numbers 1 to 12, R ¹² and R ¹³ independently represent a single bond or an alkylene group or an alkylene oxy group having 1 to 12 carbon atoms, and M represents a hydrogen atom, a Na atom, or a K atom. Alternatively, if the compound represents an onium group and the charge can be neutralized by the entire compound represented by the formula (1), it does not have to have M, m1 represents 1, 2, 3 or 4, and X ¹ represents -O-, -S- or -CH _2- , and the wavy line portion represents the bonding position with other structures.

The ^{alkyl group or aryl group represented by R 17} or R ¹⁸ is the same as the alkyl group in R ² to R ⁹ and R ⁰ or ^{the aryl group in R 0} , and the preferred embodiment is also in R ² to R ⁹ and R ⁰ . This is similar to the preferred embodiment of the alkyl group or ^{the aryl group at R0.}
The ^{alkoxy group represented by R 17} is preferably an alkoxy group having 1 to 10 carbon atoms, and a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a tert-butoxy group and the like. Can be mentioned.
n2 is preferably 0.
The counterion for neutralizing the charge represented by Zb ^{is the same as that of Z 1} in the formula (1-7), and the preferred embodiment is also the same as that of Z ¹ in the formula (1-7).
Further, the group represented by the formula formulas (2) to the ^{R 18} of (7) (5) has the same meaning as the group represented by the above-mentioned equations (2) to (5), preferred embodiments are also The same is true.

Preferred examples of R ¹ are shown below, but the present disclosure is not limited thereto. In addition, TsO ⁻ represents a tosylate anion, and ● represents a binding site with an oxygen atom.

Specific examples of the color-developing compound are shown below, but the present disclosure is not limited thereto. In the following structural formula, Me represents a methyl group and TsO ⁻ represents a tosylate anion.

The color-developing compound may be used alone or in combination of two or more.
In the image recording layer, the color-developing compound can be contained in an arbitrary amount, but from the viewpoint of edge stain suppression property, color development property, color development property over time, on-machine developability, and chemical resistance, the image is imaged. The content of the color-developing compound is preferably 0.1% by mass to 95% by mass, more preferably 1% by mass to 75% by mass, and 1% by mass to 50% by mass with respect to the total mass of the recording layer. It is particularly preferably mass%.
^{The content of the color-developing compound in the image recording layer is 1 mg / m 2} to 100 mg / m from the viewpoint of edge stain suppression, color development, color development over time, on-machine developability, and chemical resistance. ^{It is preferably 2} , more preferably 10 mg / m ² to 80 mg / m ² , and particularly preferably 20 mg / m ² to 60 mg / m ^2.

The method for producing the color-developing compound is not particularly limited, and the color-developing compound can be produced by a known method.
For example, the compound represented by the above formula (1) can be obtained as a synthetic scheme according to the synthetic method shown below.
For example, as a method for introducing a group represented by any of the above formulas 1-1, 1-5 or 1-6, synthetic schemes represented by the following formulas S1 to S3 are preferably mentioned. As a method for introducing a group represented by any of the above formulas 1-2 to 1-4, a synthetic scheme represented by the following formula S4 is preferably mentioned.
DMAP represents N, N-dimethylamino-4-pyridine, AcONa represents sodium acetate, NEt ₃ represents triethylamine, and catecol is catechol. Further, R represents a group corresponding to each portion in the formulas 1-1 to 1-7.

-Support-adsorptive compound with a molecular weight of 1,000 or less-
The image recording layer has support adsorption property from the viewpoint of edge stain suppression property and on-machine developability, has a molecular weight of 1,000 or less, and does not have an ethylenically unsaturated group in the molecule. It is preferable to contain a compound (also referred to as "support-adsorbing compound having a molecular weight of 1,000 or less" or "support-adsorbing compound").
Here, the "support adsorptivity" means the adsorptivity of the 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 that has not been washed and removed is measured. For the measurement of the residual amount, the amount of the remaining test compound may be directly quantified, or the amount of the test compound dissolved in the washing liquid may be quantified. The quantification of the test compound can be carried out by, for example, fluorescence 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.

The support-adsorptive compound preferably has a group that exhibits adsorptivity to the anodic oxide film of the aluminum support. The group exhibiting the adsorptivity to the anodic oxide film of the aluminum support is a chemical bond with a substance (for example, metal, metal oxide) or functional group (for example, hydroxy group) existing on the surface of the anodic oxide film. Examples include functional groups capable of forming (eg, ionic bonds, hydrogen bonds, coordination bonds). 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, carboxy 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 support-adsorbing compound is 1,000 or less. When the molecular weight is 1,000 or less, it easily moves to the surface of the anodic oxide film during on-machine development, and an excellent edge stain prevention effect can be obtained. The molecular weight is preferably 50 to 1,000, more preferably 50 to 800, and even more preferably 50 to 600.

The support-adsorbing compound does not have an ethylenically unsaturated group in the molecule. The ethylenically unsaturated group is a group having a polymerizable property, and includes a (meth) acrylic group, a vinyl group, an allyl group, a styryl group and the like. Since the support-adsorbing compound does not have an ethylenically unsaturated group in the molecule, it is possible to prevent the specific small molecule compound from being cured together with the image recording layer by exposure.

Oxyacid can be used as the support-adsorbing compound. An oxo acid refers to a compound in which a hydroxy group (-OH) and an oxo group (= O) are bonded to the same atom, and the hydroxy group gives an acidic proton.

Support-adsorbing compounds include phosphoric acid, polyphosphoric acid, metaphosphoric acid, ammonium primary phosphate, ammonium secondary phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, potassium primary phosphate, and phosphorus secondary. 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 Acids, 2-hydroxyethylphosphonic acid and sodium or potassium salts thereof, alkylphosphonic acid monoalkyl esters such as methyl methylphosphonate, methyl ethylphosphonate, methyl 2-hydroxyethylphosphonate and sodium or potassium salts thereof, Examples thereof include alkylene diphosphonic acids such as methylene diphosphonic acid and ethylene diphosphonic acid, sodium salts or potassium salts thereof, polyvinylphosphonic acid, p-toluenesulfonic acid, sodium p-toluenesulfonate, sulfophthalic acid, citric acid and the like. ..

As the support-adsorbing compound, a compound represented by the following formula (B) is preferable.

Wherein (B), nB is an integer of 2 to ^10, are each R ^{B1, R B2} and ^{R B3} independently represent a hydrogen atom, an alkyl group or alkylene oxide group.

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

As the support-adsorbing compound, phosphoric acid, polyphosphoric acid, phosphoric acid or phosphinic acid is particularly preferable from the viewpoint of edge stain suppressing property and on-machine developability.

Further, the support-adsorbing compound includes a hydroxy acid compound having two or more hydroxy groups (hereinafter, also referred to as “specific hydroxy acid compound”) from the viewpoint of edge stain suppression property and on-machine developability. Is preferable.

Specific hydroxy acid compounds include hydroxycarboxylic acids having two or more hydroxy groups and salts thereof. Examples of the salt include sodium salt, potassium salt, lithium salt, calcium salt, magnesium salt, aluminum salt and ammonium salt.
The number of hydroxy groups in the hydroxycarboxylic acid having two or more hydroxy groups is preferably 2 to 15, more preferably 3 to 10, and even more preferably 4 to 7.
The number of carboxy groups in the hydroxycarboxylic acid having two or more hydroxy groups is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3.

It is preferable that the specific hydroxy acid compound has high hydrophilicity from the viewpoint of preventing edge stains. The hydrophilicity of the specific hydroxy acid compound can be expressed by using the ClogP value, which is generally known as an index indicating the hydrophilicity of the compound. The specific hydroxy acid compound preferably has a ClogP value of 0.5 or less, more preferably -1 or less, and even more preferably -3 or less. Further, the ClogP value of the specific hydroxy acid compound is preferably -10 or more, more preferably -7 or more, still more preferably -5 or more, from the viewpoint of image forming property in the end region.
Here, the ClogP value of the specific hydroxy acid compound is a numerical value calculated from the molecular structure by the molecular structure editor software "ChemDraw Professional 2016".

The molecular weight of the specific hydroxy acid compound is preferably 1,000 or less. When the molecular weight is 1,000 or less, the specific hydroxy acid compound easily moves to the surface of the anodic oxide film during on-machine development, and can effectively contribute to the prevention of edge stains. The molecular weight of the specific hydroxy acid compound is more preferably 80 to 1,000, further preferably 100 to 500, and particularly preferably 100 to 300.

Specific hydroxy acid compounds include glyceric acid, gluconic acid, tartrate acid, mevalonic acid, pantoic acid, quinic acid, shikimic acid, gallic acid, coffee acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, and 2 , 5-Dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,3,4-trihydroxybenzoic acid, 3,4,5-trihydroxy Examples thereof include benzoic acid, sodium gluconate, potassium gluconate, sodium tartrate, and sodium gallic acid.
As the specific hydroxy acid compound, gluconic acid, tartaric acid, mevalonic acid, quinic acid, Na gluconate, K gluconate, or Na tartrate is preferable from the viewpoint of edge stain suppression and on-machine developability. , Na gluconate, or K gluconate is more preferable, and gluconic acid is particularly preferable.

The support-adsorbing compound may be used alone or in combination of two or more.
The content of the support-adsorbing compound in the image recording layer, edge soiling inhibitory, and, in view of on-press development ^{property, 10mg / m 2 ~ 150mg /} m 2 are ^{preferred, 30mg / m 2 ~ 100mg /} m 2 Is more preferable, and 50 mg / m ² to 100 mg / m ² is particularly preferable.
The content of the support-adsorbing compound is preferably 0.5% by mass to 20% by mass with respect to the total mass of the image recording layer from the viewpoint of edge stain suppression and on-machine developability. More preferably, it is from mass% to 15% by mass, and even more preferably from 2% by mass to 10% by mass.

-Polymerizable compound-
The image recording layer preferably contains a polymerizable compound.
The polymerizable compound used in the present disclosure may be, for example, a radical-polymerizable compound or a cationically polymerizable compound, but is an addition-polymerizable compound having at least one ethylenically unsaturated bond (ethyleney). It is preferably an unsaturated compound). The ethylenically unsaturated compound is preferably a compound having at least one terminal ethylenically unsaturated bond, and more preferably a compound having two or more terminal ethylenically unsaturated bonds. The polymerizable compound has 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, etc.), esters thereof, amides, etc., and unsaturated carboxylic acids are preferable. Esters of acids and polyhydric alcohol compounds and amides of unsaturated carboxylic acids and polyhydric amine compounds are used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxy group, an amino group or a mercapto group with a monofunctional or polyfunctional isocyanate or an epoxy, and a monofunctional or polyfunctional group. A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of unsaturated carboxylic acid esters or amides having an electrophilic substituent such as an isocyanate group or an epoxy group with monofunctional or polyfunctional alcohols, amines and thiols, and a halogen atom, Substituents of unsaturated carboxylic acid esters or amides having a releasable substituent such as a tosyloxy group with monofunctional or polyfunctional alcohols, amines and thiols are also suitable. Further, as another example, it is also possible to use a compound group in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene, vinyl ether or the like. These are 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-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 Kaihei 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. Trimethylol propan triacrylate, hexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol tetraacrylate, sorbitol triacrylate, isocyanurate ethylene oxide (EO) modified triacrylate, polyester acrylate oligomer and the like. As methacrylic acid ester, tetramethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropantrimethacrylate, ethylene glycol dimethacrylate, pentaerythritol trimethacrylate, bis [p- (3-methacryloxy-2-hydroxypropoxy) phenyl] There are dimethylmethane, bis [p- (methacrylicoxyethoxy) phenyl] dimethylmethane and the like. 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-hexamethylenebismethacrylamide. Diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide and the like.

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, 2 in 1 molecule described in Japanese Patent Publication No. 48-41708. A vinyl urethane compound 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. And so on.
_{^{_{CH 2 = C (R M4)}}} COOCH 2 CH (R M5) OH (M)
In formula (M), ^RM4 and ^RM5 each independently represent a hydrogen atom or a methyl group.

Further, the urethane acrylates described in JP-A-51-37193, JP-A-2-32293, JP-A-2-16765, JP-A-2003-344997, and JP-A-2006-65210, The ethylenes described in JP-A-58-49860, JP-A-56-17654, JP-A-62-39417, JP-A-62-39418, JP-A-2000-250211 and JP-A-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 method of use such as the structure of the polymerizable compound, whether it is used alone or in combination, and the amount of addition can be arbitrarily set.
The content of the polymerizable compound is preferably 5% by mass to 75% by mass, more preferably 10% by mass to 70% by mass, and 15% by mass to 60% by mass with respect to the total mass of the image recording layer. It is particularly preferably mass%.

-Polymerization initiator-
The image recording layer in the lithographic printing plate original plate according to the present disclosure preferably contains a polymerization initiator, and more preferably contains a polymerization initiator and a polymerizable compound.
Further, the polymerization initiator preferably contains an electron-accepting type polymerization initiator, and more preferably contains an electron-accepting type polymerization initiator and an electron-donating type polymerization initiator.

<< Electron Receptor Polymerization Initiator >>
The image recording layer preferably contains an electron-accepting polymerization initiator as the polymerization initiator.
The electron-accepting polymerization initiator is a compound that generates a polymerization initiator such as a radical by accepting one electron by electron transfer between molecules when the electrons of the infrared absorber are excited by infrared exposure.
The electron-accepting polymerization initiator used in the present disclosure 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 and has a small bond dissociation energy. A compound having a bond, a photopolymerization initiator and the like can be appropriately selected and used.
As the electron-accepting polymerization initiator, a radical polymerization initiator is preferable, and an onium salt compound is more preferable.
Further, the electron-accepting polymerization initiator is preferably an infrared photosensitive polymerization initiator.
Examples of the electron-accepting radical polymerization initiator include (a) organic halides, (b) carbonyl compounds, (c) azo compounds, (d) organic peroxides, (e) metallocene compounds, and (f) azide compounds. , (G) hexaarylbiimidazole compounds, (i) disulfone compounds, (j) oxime ester compounds, and (k) onium salt compounds.

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

Among the electron-accepting polymerization initiators, oxime ester compounds and onium salt compounds are preferable from the viewpoint of curability. Among them, from the viewpoint of printing resistance, an iodonium salt compound, a sulfonium salt compound or an azinium salt compound is preferable, an iodonium salt compound or a sulfonium salt compound is more preferable, and an iodonium salt compound is particularly preferable.
Specific examples of these compounds are shown below, but the present disclosure is not limited thereto.

As an example of the iodonium salt compound, a diaryl iodonium salt compound is preferable, a diphenyl iodonium salt compound substituted with an electron donating group such as an alkyl group or an alkoxyl group is more preferable, and an asymmetric diphenyl iodonium salt compound is 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-perfluorobutane sulfonate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, bis (4-t-butylphenyl) ) Iodonium = hexafluorophosphate can be mentioned.

As an example of the sulfonium salt compound, a triarylsulfonium salt compound is preferable, and in particular, an electron-attracting group, for example, a triarylsulfonium salt compound in which at least a part of a group on the aromatic ring is substituted with a halogen atom is preferable, and an aromatic is preferable. A triarylsulfonium salt compound having a total number of halogen atoms substituted on the 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. Borate, Tris (4-chlorophenyl) Sulfonium = 3,5-bis (methoxycarbonyl) Benzene Sulfonium, Tris (4-chlorophenyl) Sulfonium = Hexafluorophosphate, Tris (2,4-dichlorophenyl) Sulfonium = Hexafluorophos Fert can be mentioned.

Examples of the counter anion of the iodonium salt compound and the sulfonium salt compound include a sulfonate anion, a carboxylate anion, a tetrafluoroborate anion, a hexafluorophosphate anion, a p-toluene sulfonate anion, a tosylate anion, a sulfonamide anion or a sulfonimide. Anions can be mentioned.
Among the above, a sulfonamide anion or a sulfonimide anion is preferable, and a sulfonimide anion is more preferable.
As the sulfonamide anion, an aryl sulfonamide anion is preferable.
Further, as the sulfonimide anion, a bisaryl sulfonimide anion is preferable.
Specific examples of the sulfonamide anion or the sulfonamide anion are shown below, but the present disclosure is not limited thereto. In the specific examples below, Ph represents a phenyl group, Me represents a methyl group, and Et represents an ethyl group.

The minimum unoccupied molecular orbital (LUMO) of the electron-accepting polymerization initiator is preferably −3.00 eV or less, and more preferably −3.02 eV or less, from the viewpoint of improving sensitivity.
The lower limit is preferably -3.80 eV or more, and more preferably -3.60 eV or more.

The electron-accepting polymerization initiator may be used alone or in combination of two or more.
The content of the electron-accepting polymerization initiator is preferably 0.1% by mass to 50% by mass, more preferably 0.5% by mass to 30% by mass, based on the total mass of the image recording layer. It is preferably 0.8% by mass to 20% by mass, and particularly preferably 0.8% by mass.

<< Electron-donated polymerization initiator (polymerization aid) >>
The image recording layer preferably contains an electron-donating polymerization initiator (also referred to as a "polymerization aid") as a polymerization initiator, and contains an electron-accepting polymerization initiator and an electron-donating polymerization initiator. Is more preferable.
The electron donating type polymerization initiator in the present disclosure donates one electron by intermolecular electron transfer to an orbit where one electron is missing from the infrared absorber when the electron of the infrared absorber is excited or moved intramolecularly by infrared exposure. This is a compound that generates a polymerization-initiated species such as a radical.
The electron-donating type polymerization initiator is preferably an electron-donating radical polymerization initiator.
From the viewpoint of improving the printing durability of the lithographic printing plate, the image recording layer more preferably contains the electron donating type polymerization initiator described below, and examples thereof include the following five types.
(I) Alkyl or aryl ate complex: It is considered that the carbon-heterobond is oxidatively cleaved to generate an active radical. Specifically, a borate compound is preferable.
(Ii) N-arylalkylamine compound: It is considered that the CX bond on the carbon adjacent to nitrogen is cleaved by oxidation to generate an active radical. As X, a hydrogen atom, a carboxyl group, a trimethylsilyl group or a benzyl group is preferable. Specifically, for example, N-phenylglycins (which may or may not have a substituent on the phenyl group) and N-phenyliminodiacetic acid (which may or may not have a substituent on the phenyl group). May be mentioned.)
(Iii) Sulfur-containing compound: The above-mentioned amines in which the nitrogen atom is replaced with a sulfur atom can generate an active radical by the same action. For example, phenylthioacetic acid (which may or may not have a substituent on the phenyl group) can be mentioned.
(Iv) Tin-containing compounds: The above-mentioned amines in which the nitrogen atom is replaced with a tin atom can generate active radicals by the same action.
(V) Sulfinates: Oxidation can generate active radicals. Specific examples thereof include arylsulfinic sodium.

Among these, the image recording layer preferably contains a borate compound from the viewpoint of printing resistance.
The borate compound is preferably a tetraaryl borate compound or a monoalkyl triaryl borate compound, and more preferably a tetraaryl borate compound from the viewpoint of print resistance and color development.
The counter cation contained in the borate compound is not particularly limited, but is preferably an alkali metal ion or a tetraalkylammonium ion, and more preferably a sodium ion, a potassium ion, or a tetrabutylammonium ion.

Specifically, sodium tetraphenylborate is preferably mentioned as the borate compound.

B-1 to B-9 are shown below as preferable specific examples of the electron donating type polymerization initiator, but it goes without saying that the present invention is not limited to these. Further, in the following chemical formula, Ph represents a phenyl group and Bu represents an n-butyl group.

Further, the maximum occupied molecular orbital (HOMO) of the electron donating polymerization initiator used in the present disclosure is preferably −6.00 eV or higher, and preferably −5.95 eV or higher, from the viewpoint of improving sensitivity. More preferably, it is more preferably −5.93 eV or more.
The upper limit is preferably −5.00 eV or less, and more preferably −5.40 eV or less.

The electron donating type polymerization initiator may contain only one type, or two or more types may be used in combination.
The content of the electron donating type polymerization initiator is preferably 0.01% by mass to 30% by mass, preferably 0.05% by mass, based on the total mass of the image recording layer from the viewpoint of sensitivity and printing resistance. It is more preferably about 25% by mass, and even more preferably 0.1% by mass to 20% by mass.

In the present disclosure, when the image recording layer contains an onium ion and an anion in the above-mentioned electron donating type polymerization initiator, the image recording layer is assumed to contain an electron accepting type polymerization initiator and the above-mentioned electron donating type polymerization initiator. ..

-Relationship between electron donating polymerization initiator and infrared absorber-
From the viewpoint of improving sensitivity, the image recording layer in the present disclosure contains the electron-donating polymerization initiator and the infrared absorber described later, and the value of HOMO of the infrared absorber-HOMO of the electron-donating polymerization initiator is determined. It is preferably 0.70 eV or less, and more preferably 0.70 eV to −0.10 eV.
A negative value means that the HOMO of the electron donating polymerization initiator is higher than that of the infrared absorber HOMO.

-Preferable aspects of infrared absorbers and electron-accepting polymerization initiators-
Further, as an infrared absorber to be described later, from the viewpoint of improving sensitivity, an organic anion having δd of 16 or more, δp of 16 to 32, and δh of 60% or less of δp in the solubility parameter of Hansen. Is a preferred embodiment.
The electron-accepting polymerization initiator in the present disclosure has a Hansen solubility parameter of δd of 16 or more, δp of 16 to 32, and δh of 60% or less of δp from the viewpoint of improving sensitivity. It is a preferred embodiment to have an organic anion.

Here, δd, δp and δh in the Hansen solubility parameter in the present disclosure have the dispersion term δd [unit: MPa ^0.5 ] and the polar term δp [unit: MPa ^0.5 ] in the Hansen solubility parameter. Use. Here, the solubility parameter of Hansen is expressed in a three-dimensional space by dividing the solubility parameter introduced by Hildebrand into three components of a dispersion term δd, a polar term δp, and a hydrogen bond term δh. It is a thing.
For more information on the Hansen solubility parameter, see Charles M. et al. It is described in the document "Hansen Solubility Parameter; A Users Handbook (CRC Press, 2007)" by Hansen.

In the present disclosure, δd, δp and δh in the Hansen solubility parameter of the organic anion are estimated from the chemical structure by using the computer software “Hansen Solubility Parameters in Practice (HSPiP ver. 4.1.07)”. The value.

Specific examples of the organic anions having δd of 16 or more, δp of 16 to 32, and δh of 60% or less of δp in the solubility parameter of Hansen are the above-mentioned I-1 to I-15 and I. -17 to I-21, I-23 to I-25, and the following are preferably mentioned, but it goes without saying that the present invention is not limited thereto. Among them, bis (halogen-substituted benzenesulfonyl) imide anion is more preferably mentioned, and I-5 described above is particularly preferable.

-particle-
The image recording layer preferably contains particles from the viewpoint of UV printing resistance.
The particles may be organic particles or inorganic particles, but from the viewpoint of UV printing resistance, they preferably contain organic particles, and more preferably polymer particles.
As the inorganic particles, known inorganic particles can be used, and metal oxide particles such as silica particles and titania particles can be preferably used.

The polymer particles may be selected from the group consisting of thermoplastic polymer particles, heat-reactive polymer particles, polymer particles having a polymerizable group, microcapsules containing a hydrophobic compound, and microgels (crosslinked polymer particles). preferable. Of these, polymer particles or microgels having a polymerizable group are preferable. In a particularly preferred embodiment, the polymer particles contain at least one ethylenically unsaturated polymerizable group. The presence of such polymer particles has the effect of enhancing the printing resistance of the exposed portion and the on-machine developability of the unexposed portion.
Further, the polymer particles are preferably thermoplastic polymer particles.

As the thermoplastic polymer particles, Research Discovery No. 1 of January 1992. 33303, JP-A-9-123387, 9-131850, 9-171249, 9-171250, European Patent No. 913647, and the like are preferred.
Specific examples of the polymer constituting the thermoplastic polymer particles include ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinylcarbazole, and a polyalkylene structure. Examples include homopolymers or copolymers of monomers such as acrylates or methacrylates or mixtures thereof. Preferably, a copolymer containing polystyrene, styrene and acrylonitrile, or polymethyl methacrylate can be mentioned. The average particle size of the thermoplastic polymer particles is preferably 0.01 μm to 3.0 μm.

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

The thermally reactive group in the polymer particles having a thermally reactive group may be a functional group that undergoes any reaction as long as a chemical bond is formed, but a polymerizable group is preferable, and as an example, it is preferable. Eethylene unsaturated groups (eg, acryloyl group, methacryloyl group, vinyl group, allyl group, etc.), cationically polymerizable groups (eg, vinyl group, vinyloxy group, epoxy group, oxetanyl group, etc.), addition reaction Isocyanato group or a block body thereof, an epoxy group, a vinyloxy group and a functional group having an active hydrogen atom which is a reaction partner thereof (for example, an amino group, a hydroxy group, a carboxy group, etc.), a carboxy group for performing a condensation reaction and a reaction. Preferred examples thereof include a hydroxy group or an amino group as a partner, an acid anhydride for carrying out a ring-opening addition reaction, and an amino group or a hydroxy group as a reaction partner.

Examples of the microcapsules include those in which at least a part of the constituent components of the image recording layer is encapsulated in the 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. The image recording layer containing the microcapsules is preferably configured such that the hydrophobic constituents are encapsulated in the microcapsules and the hydrophilic constituents are contained outside the microcapsules.

The microgel (crosslinked polymer particles) can contain a part of the constituent components of the image recording layer on at least one of the surface or the inside thereof. In particular, a reactive microgel having a radically polymerizable group on its surface is preferable from the viewpoint of the sensitivity of the obtained lithographic printing plate original plate and the printing durability of the obtained lithographic printing plate.

A known method can be applied to microencapsulate or microgelify the constituents of the image recording layer.

Further, as the polymer particles, an adduct of a polyhydric phenol compound having two or more hydroxy groups in the molecule and isophorone diisocyanate from the viewpoint of printing resistance, stain resistance and storage stability of the obtained flat plate printing plate. The one obtained by the reaction of the polyhydric isocyanate compound and the compound having active hydrogen is preferable.
As the polyvalent phenol compound, a compound having a plurality of benzene rings having a phenolic hydroxyl group is preferable.
As the compound having active hydrogen, a polyol compound or a polyamine compound is preferable, a polyol compound is more preferable, and at least one compound selected from the group consisting of propylene glycol, glycerin and trimethylolpropane is further preferable.
Examples of the resin particles obtained by the reaction of the polyhydric phenol compound having two or more hydroxy groups in the molecule, the polyhydric isocyanate compound which is an adduct of isophorone diisocyanate, and the compound having active hydrogen are JP-A-2012. The polymer particles described in paragraphs 0032 to 0905 of JP-206495 are preferably mentioned.

Further, the polymer particles have a hydrophobic main chain from the viewpoint of printing resistance and solvent resistance of the obtained lithographic printing plate, and i) a pendant cyano group directly bonded to the hydrophobic main chain. It is preferable to include both a constituent unit having and ii) a constituent unit having a pendant group containing a hydrophilic polyalkylene oxide segment.
Acrylic resin chains are preferably mentioned as the hydrophobic main chain.
Examples of the pendant cyano group _{preferably include- [CH 2} CH (C≡N)-] or-[CH ₂ C (CH ₃ ) (C≡N)-].
In addition, the constituent unit having the pendant cyano group can be easily derived from an ethylene-based unsaturated monomer, for example, acrylonitrile or methacrylonitrile, or a combination thereof.
Further, as the alkylene oxide in the hydrophilic polyalkylene oxide segment, ethylene oxide or propylene oxide is preferable, and ethylene oxide is more preferable.
The number of repetitions of the alkylene oxide structure in the hydrophilic polyalkylene oxide segment is preferably 10 to 100, more preferably 25 to 75, and even more preferably 40 to 50.
Both a constituent unit having a hydrophobic backbone and i) having a pendant cyano group directly attached to the hydrophobic backbone and ii) a constituent unit having a pendant group containing a hydrophilic polyalkylene oxide segment. As the resin particles containing the above, those described in paragraphs 0039 to 0068 of JP-A-2008-503365 are preferably mentioned.

Further, the polymer particles preferably have a hydrophilic group from the viewpoint of UV printing resistance and on-machine developability.
The hydrophilic group is not particularly limited as long as it has a hydrophilic structure, and examples thereof include an acid group such as a carboxy group, a hydroxy group, an amino group, a cyano group, and a polyalkylene oxide structure.
Above all, from the viewpoint of on-machine developability and UV printing resistance, a polyalkylene oxide structure is preferable, and a polyethylene oxide structure, a polypropylene oxide structure, or a polyethylene / propylene oxide structure is more preferable.
Further, from the viewpoint of on-machine developability and ability to suppress development residue during on-machine development, the polyalkylene oxide structure preferably has a polypropylene oxide structure, and may have a polyethylene oxide structure and a polypropylene oxide structure. More preferred.
Further, the hydrophilic group preferably contains a structural unit having a cyano group or a group represented by the following formula Z from the viewpoint of printing resistance, inking property and on-machine developability. It is more preferable to include a structural unit represented by the following formula (AN) or a group represented by the following formula Z, and it is particularly preferable to include a group represented by the following formula Z.
* -Q-W-Y formula Z
In formula Z, Q represents a divalent linking group, W represents a divalent group having a hydrophilic structure or a divalent group having a hydrophobic structure, and Y represents a monovalent group having a hydrophilic structure or It represents a monovalent group having a hydrophobic structure, either W or Y has a hydrophilic structure, and * represents a binding site with another structure.

In formula (AN), ^RAN represents a hydrogen atom or a methyl group.

From the viewpoint of UV printing resistance, the polymer contained in the polymer particles preferably contains a structural unit formed of a compound having a cyano group.
The cyano group is usually preferably introduced as a structural unit containing a cyano group by using a compound (monomer) having a cyano group. Examples of the compound having a cyano group include acrylonitrile compounds, and (meth) acrylonitrile is preferable.
The structural unit having a cyano group is preferably a structural unit formed of an acrylonitrile compound, and more preferably a structural unit formed of (meth) acrylonitrile, that is, a structural unit represented by the above formula (AN). ..
When the polymer contains a polymer having a structural unit having a cyano group, the content of the structural unit having a cyano group, preferably the structural unit represented by the above formula (AN), in the polymer having a structural unit having a cyano group. Is preferably 5% by mass to 90% by mass, more preferably 20% by mass to 80% by mass, based on the total mass of the polymer having a structural unit having a cyano group, from the viewpoint of UV printing resistance. It is preferably 30% by mass to 60% by mass, and particularly preferably 30% by mass.

From the viewpoint of UV print resistance, the polymer particles preferably contain a structural unit formed of an aromatic vinyl compound.
The aromatic vinyl compound may be a compound having a structure in which a vinyl group is bonded to an aromatic ring, and examples thereof include a styrene compound and a vinylnaphthalene compound, and a styrene compound is preferable, and styrene is more preferable.
Examples of the styrene compound include styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p-methoxy-β-methylstyrene and the like. Styrene is preferred.
Examples of the vinylnaphthalene compound include 1-vinylnaphthalene, methyl-1-vinylnaphthalene, β-methyl-1-vinylnaphthalene, 4-methyl-1-vinylnaphthalene, 4-methoxy-1-vinylnaphthalene and the like. -Vinylnaphthalene is preferably mentioned.

Further, as the structural unit formed of the aromatic vinyl compound, the structural unit represented by the following formula Z1 is preferably mentioned.

In the formula Z1, R ^Z1 and R ^Z2 independently represent a hydrogen atom or an alkyl group, Ar represents an aromatic ring group, R ^Z3 represents a substituent, and nz is an integer of 0 or more and less than or equal to the maximum number of substituents of Ar. Represents.
In the formula Z1, R ^Z1 and R ^Z2 are each independently preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and both are hydrogen atoms. Is more preferable.
In the formula Z1, Ar is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.
In the formula Z1, R ^Z3 is preferably an alkyl group or an alkoxy group, more preferably an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and it is a methyl group or a methoxy group. Is more preferable.
In the formula Z1, if the R ^Z3 there are a plurality, plural of R ^Z3 may be the same or may be different.
In the formula Z1, nz is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0.

The polymer particles may contain one type of structural unit formed of an aromatic vinyl compound alone, or may contain two or more types.
In the polymer particles, the content of the structural unit formed by the aromatic vinyl compound may be 0.1% by mass to 20% by mass with respect to the total mass of the polymer particles from the viewpoint of ink inking property. It is preferably 0.5% by mass to 15% by mass, and particularly preferably 1% by mass to 10% by mass.

Further, the polymer particles preferably have a crosslinked structure, and more preferably contain a structural unit having a crosslinked structure, from the viewpoint of UV printing resistance.
Since the polymer particles have a crosslinked structure, the hardness of the polymer particles themselves is improved, so that the image area strength is improved, and even when an ultraviolet curable ink that easily deteriorates the plate than other inks is used. It is considered that the printing resistance (UV printing resistance) is further improved.
The crosslinked structure is not particularly limited, but is a structural unit formed by polymerizing a polyfunctional ethylenically unsaturated compound, or a structural unit in which one or more reactive groups form a covalent bond inside the particles. Is preferable. The functional number of the polyfunctional ethylenically unsaturated compound is preferably 2 to 15, more preferably 3 to 10, and 4 to 10 from the viewpoint of UV printing resistance and on-machine developability. It is more preferably present, and particularly preferably 5 to 10.
In other words, the structural unit having the crosslinked structure is preferably a bifunctional to 15-functional branched unit from the viewpoint of UV printing resistance and on-machine developability.
The n-functional bifurcation unit is a bifurcation unit having n molecular chains, in other words, a structural unit having an n-functional bifurcation point (crosslinked structure).
It is also preferable to form a crosslinked structure with a polyfunctional mercapto compound.

The ethylenically unsaturated group in the polyfunctional ethylenically unsaturated compound is not particularly limited, and examples thereof include a (meth) acryloxy group, a (meth) acrylamide group, an aromatic vinyl group, and a maleimide group.
The polyfunctional ethylenically unsaturated compound is preferably a polyfunctional (meth) acrylate compound, a polyfunctional (meth) acrylamide compound, or a polyfunctional aromatic vinyl compound.

Examples of the polyfunctional (meth) acrylate compound include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylol propane diacrylate, trimethylol propane triacrylate, 1,4-butanediol diacrylate, and 1,6. -Hexanediol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, tricyclodecanedimethylol diacrylate, ditrimethylol propanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol triacrylate, dipentaerythritol hexa. Examples thereof include acrylate and triacrylate of tris (β-hydroxyethyl) isocyanurate.
Examples of the polyfunctional (meth) acrylate compound include N, N'-methylenebisacrylamide, N- [tris (3-acrylamide propoxymethyl) methyl] acrylamide and the like.
Examples of the polyfunctional aromatic vinyl compound include divinylbenzene and the like.

The number of carbon atoms in the branching unit is not particularly limited, but is preferably 8 to 100, and more preferably 8 to 70.

The polymer particles may contain one type of structural unit having a crosslinked structure alone, or may contain two or more types.
In the polymer particles, the content of the structural unit having a crosslinked structure is 0.1% by mass to 20% by mass with respect to the total mass of the polymer particles from the viewpoint of UV printing resistance and on-machine developability. Is more preferable, and it is more preferably 0.5% by mass to 15% by mass, and particularly preferably 1% by mass to 10% by mass.

Further, the polymer particles preferably contain polymer particles having a group represented by the above formula Z from the viewpoints of printing resistance, fillability, and on-machine developability.

Q in the above formula Z is preferably a divalent linking group having 1 to 20 carbon atoms, and more preferably a divalent linking group having 1 to 10 carbon atoms.
Further, Q in the above formula Z is preferably an alkylene group, an arylene group, an ester bond, an amide bond, or a group in which two or more of these are combined, and may be a phenylene group, an ester bond, or an amide bond. More preferred.

The divalent group having a hydrophilic structure in W of the above formula Z is preferably a polyalkyleneoxy group or a group in which -CH ₂ CH ₂ NR ^W- is bonded to one end of a polyalkyleneoxy group. .. Incidentally, R ^W represents a hydrogen atom or an alkyl group.
^The divalent group having a hydrophobic structure in the W of formula ^{^{Z, -R WA -, - O}} -R WA -O -, - R W N-R WA -NR W -, - OC (= O) - R ^WA -O-, or, -OC (= ^O) is preferably ^-R WA -O-. The ^RWAs are independently linear, branched or cyclic alkylene groups having 6 to 120 carbon atoms, haloalkylene groups having 6 to 120 carbon atoms, arylene groups having 6 to 120 carbon atoms, and alkanelylenes having 6 to 120 carbon atoms. It represents a group (a divalent group obtained by removing one hydrogen atom from an alkylaryl group) or an aralkylene group having 6 to 120 carbon atoms.

The monovalent group having a hydrophilic structure in Y of the above formula Z is -OH, -C (= O) OH, a polyalkyleneoxy group having a hydrogen atom or an alkyl group at the end, or a hydrogen atom or an alkyl at the end. it is preferably bound group - at the other end of the polyalkyleneoxy group is a group _{_{^{-CH 2 CH 2 N (R W}}} ).
The monovalent group having a hydrophobic structure in Y of the above formula Z is a linear, branched or cyclic alkyl group having 6 to 120 carbon atoms, a haloalkyl group having 6 to 120 carbon atoms, an aryl group having 6 to 120 carbon atoms, and the like. It may be an alcoholyl group (alkylaryl group) having 6 to 120 carbon atoms, an aralkyl group having 6 to 120 carbon atoms, -OR ^WB , -C (= O) OR ^WB , or -OC (= O) R ^WB. preferable. ^RWB represents an alkyl group having 6 to 20 carbon atoms.

The polymer particle having a group represented by the above formula Z is more preferably a divalent group in which W has a hydrophilic structure from the viewpoints of print resistance, carving property and on-machine developability. More preferably, Q is a phenylene group, an ester bond, or an amide bond, W is a polyalkyleneoxy group, and Y is a polyalkyleneoxy group having a hydrogen atom or an alkyl group at the end.

Further, the polymer particles preferably contain polymer particles having a polymerizable group from the viewpoints of print resistance, fillability and on-machine developability, and include polymer particles having a polymerizable group on the particle surface. Is more preferable.
Further, the polymer particles preferably contain polymer particles having a hydrophilic group and a polymerizable group from the viewpoint of printing resistance.
The polymerizable group may be a cationically polymerizable group or a radically polymerizable group, but from the viewpoint of reactivity, it is preferably a radically polymerizable group.
The polymerizable group is not particularly limited as long as it is a polymerizable group, but from the viewpoint of reactivity, an ethylenically unsaturated group is preferable, and a vinylphenyl group (styryl group), a (meth) acryloxy group, or a (meth) acryloxy group, or A (meth) acrylamide group is more preferred, and a (meth) acryloxy group is particularly preferred.
Further, the polymer in the polymer particles having a polymerizable group preferably has a structural unit having a polymerizable group.
Further, a polymerizable group may be introduced on the surface of the polymer particles by a polymer reaction.

Further, the polymer particles preferably contain a resin having a urea bond from the viewpoints of printing resistance, inking property, on-machine developability, and ability to suppress development residue during on-machine development, and are preferably represented by the following formula (Iso). It is more preferable to contain a resin having a structure obtained by at least reacting the isocyanate compound represented by water with water, and having a structure obtained by at least reacting the isocyanate compound represented by the following formula (Iso) with water. However, it is particularly preferable that the polyoxyalkylene structure contains a resin having a polyethylene oxide structure and a polypropylene oxide structure. Further, the particles containing the resin having the urea bond are preferably microgels.

In the formula (Iso), n represents an integer from 0 to 10.

An example of the reaction between the isocyanate compound represented by the above formula (Iso) and water is the reaction shown below. The following example is an example using n = 0, 4,4-isomer.
As shown below, when the isocyanate compound represented by the above formula (Iso) is reacted with water, a part of the isocyanate group is hydrolyzed by water to generate an amino group, and the generated amino group and isocyanate group React, forming urea bonds and forming dimers. Further, the following reaction is repeated to form a resin having a urea bond.
Further, in the following reaction, by adding a compound (compound having active hydrogen) reactive with an isocyanate group such as an alcohol compound or an amine compound, the structure of the alcohol compound, the amine compound or the like is introduced into the resin having a urea bond. You can also do it.
As the compound having active hydrogen, those described in the above-mentioned microgel are preferably mentioned.

Further, the resin having a urea bond preferably has an ethylenically unsaturated group, and more preferably has a group represented by the following formula (PETA).

In the formula (PETA), the wavy line part represents the connection position with other structures.

The average particle size of the particles is preferably 0.01 μm to 3.0 μm, more preferably 0.03 μm to 2.0 μm, and even more preferably 0.10 μm to 1.0 μm. Good resolution and stability over time can be obtained in this range.
The average primary particle size of the particles in the present disclosure is measured by a light scattering method, or an electron micrograph of the particles is taken, and a total of 5,000 particle sizes are measured on the photographs, and the average value is obtained. Shall be calculated. For non-spherical particles, the particle size value of spherical particles having the same particle area as the particle area on the photograph is used as the particle size.
Further, the average particle size in the present disclosure shall be the volume average particle size unless otherwise specified.

The image recording layer may contain particles, particularly polymer particles, alone or in combination of two or more.
The content of the particles in the image recording layer, particularly the polymer particles, is preferably 5% by mass to 90% by mass, preferably 10% by mass, based on the total mass of the image recording layer from the viewpoint of developability and UV printing resistance. It is more preferably% to 90% by mass, further preferably 20% by mass to 90% by mass, and particularly preferably 50% by mass to 90% by mass.
The content of the polymer particles in the image recording layer is 20% by mass to 100% by mass with respect to the total mass of the components having a molecular weight of 3,000 or more in the image recording layer from the viewpoint of developability and UV printing resistance. It is preferably by mass, more preferably 35% by mass to 100% by mass, further preferably 50% by mass to 100% by mass, and particularly preferably 80% by mass to 100% by mass.

-Binder polymer-
The image recording layer may contain a binder polymer, but is preferably not contained from the viewpoint of on-machine developability and UV printing resistance.
The binder polymer is a polymer other than the polymer particles, that is, a binder polymer that is not in the form of particles.
As the binder polymer, a (meth) acrylic resin, a polyvinyl acetal resin, or a polyurethane resin is preferable.

Above all, as the binder polymer, a known binder polymer used for the image recording layer of the lithographic printing plate original plate can be preferably used. As an example, a binder polymer (hereinafter, also referred to as a binder polymer for on-machine development) used in an on-machine development type lithographic printing plate original plate 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 a poly (alkylene oxide) in a side chain, or a block copolymer of a block composed of a poly (alkylene oxide) -containing repeating unit and a block composed of a (alkylene oxide) -free repeating unit.
When the main chain has a poly (alkylene oxide) moiety, a polyurethane resin is preferable. When the main chain polymer 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.

Further, as another preferable example of the binder polymer, a high molecular weight polymer chain having a polyfunctional thiol having 6 or more functionalities or 10 functionalities as a nucleus and being bonded to the nucleus by a sulfide bond, and the polymer chain having a polymerizable group. Molecular compounds (hereinafter, also referred to as star-shaped polymer compounds) can be mentioned. As the star-shaped polymer compound, for example, the compound described in JP-A-2012-148555 can be preferably used.

The star-shaped polymer compound contains a polymerizable group such as an ethylenically unsaturated bond for improving the film strength of the image portion as described in JP-A-2008-195018, with a main chain or a side chain, preferably a side chain. Examples include those held in the chain. The polymerizable group forms crosslinks between the polymer molecules to promote curing.
As the polymerizable group, an ethylenically unsaturated group such as a (meth) acrylic group, a vinyl group, an allyl group or a styryl group, an epoxy group or the like is preferable, and the (meth) acrylic group, the vinyl group or the styryl group is a polymerization reaction. It is more preferable from the viewpoint of sex, and a (meth) acrylic group is particularly preferable. These groups can be introduced into the polymer by polymer reaction or copolymerization. For example, a reaction between a polymer having a carboxy group in the side chain and glycidyl methacrylate, or a reaction between a polymer having an epoxy group and an ethylenically unsaturated group-containing carboxylic acid such as methacrylic acid can be used. These groups may be used together.

The molecular weight of the binder polymer is preferably 2,000 or more, more preferably 5,000 or more, and 10,000 to 300,000 in terms of polystyrene by the GPC method. It is more preferable to have.

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.

In the image recording layer used in the present disclosure, one type of binder polymer may be used alone, or two or more types may be used in combination.
The binder polymer can be contained in the image recording layer in an arbitrary amount, but from the viewpoint of on-machine developability and UV printing resistance, the binder polymer is not contained or the binder polymer is used. The content is preferably more than 0% by mass and 20% by mass or less with respect to the total mass of the image recording layer, and either does not contain the binder polymer or the content of the binder polymer is the image recording layer. It is more preferable that it is more than 0% by mass and 10% by mass or less with respect to the total mass of the image recording layer, and the binder polymer is not contained or the content of the binder polymer is based on the total mass of the image recording layer. , 0% by mass and 5% by mass or less, and the binder polymer is not contained, or the content of the binder polymer exceeds 0% by mass with respect to the total mass of the image recording layer. It is particularly preferably 2% by mass or less, and most preferably does not contain the above binder polymer.

-Infrared absorber-
From the viewpoint of sensitivity, the image recording layer may contain an infrared absorber (also simply referred to as “infrared absorber”) other than the color-developing compound.
The infrared absorber is not particularly limited, and examples thereof include pigments and dyes.
As the dye used as the infrared absorber, a commercially available dye and, for example, 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 these dyes, particularly preferable ones include cyanine pigments, squarylium pigments, pyrylium salts, nickel thiolate complexes, and indolenin cyanine pigments. Further, cyanine pigments and indorenin cyanine pigments can be mentioned. Of these, the cyanine pigment is particularly preferable.

The infrared absorber is preferably a cationic polymethine dye having an oxygen or nitrogen atom at the meso position. Preferred examples of the cationic polymethine pigment include cyanine pigments, pyrylium pigments, thiopyrylium pigments, and azulenium pigments, and cyanine pigments are preferable from the viewpoints of availability, solvent solubility at the time of introduction reaction, and the like.

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 of JP-A-2007-90850. Examples thereof include the compounds described in Japanese Patent Application Laid-Open No. 2012-206495, and the compounds described in paragraphs 0105 to 0113 of JP2012-206495A.
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.

Only one type of infrared absorber may be used, or two or more types may be used in combination. Further, a pigment and a dye may be used in combination as an infrared absorber.
The content of the infrared absorber in the image recording layer is preferably 0.1% by mass to 10.0% by mass, more preferably 0.5% by mass to 5.0% by mass, based on the total mass of the image recording layer. preferable.

-Acid color former-
The image recording layer preferably contains an acid color former. Further, the acid color former preferably contains a leuco compound.
The "acid color former" used in the present disclosure has a property of developing or decoloring and changing the color of the image recording layer by heating in a state of receiving an electron-accepting compound (for example, a proton such as an acid). Means a compound. The acid color former has a partial skeleton such as lactone, lactam, salton, spiropyrane, ester, and amide, and when it comes into contact with an electron-accepting compound, these partial skeletons are rapidly ring-opened or cleaved. Compounds are preferred.

Examples of such acid color formers are 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide (referred to as "crystal violet lactone") and 3,3-bis (4). -Dimethylaminophenyl) phthalide, 3- (4-dimethylaminophenyl) -3- (4-diethylamino-2-methylphenyl) -6-dimethylaminophthalide, 3- (4-dimethylaminophenyl) -3- ( 1,2-dimethylindole-3-yl) phthalide, 3- (4-dimethylaminophenyl) -3- (2-methylindole-3-yl) phthalide, 3,3-bis (1,2-dimethylindole-) 3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindole-3-yl) -6-dimethylaminophthalide, 3,3-bis (9-ethylcarbazole-3-3) Il) -6-dimethylaminophthalide, 3,3-bis (2-phenylindole-3-yl) -6-dimethylaminophthalide, 3- (4-dimethylaminophenyl) -3- (1-methylpyrrole) -3-yl) -6-dimethylaminophthalide,

3,3-bis [1,1-bis (4-dimethylaminophenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3,3-bis [1,1-bis (1,1-bis) 4-Pyrrolidinophenyl) ethylene-2-yl] -4,5,6,7-tetrabromophthalide, 3,3-bis [1- (4-dimethylaminophenyl) -1- (4-methoxyphenyl) Ethyl-2-yl] -4,5,6,7-tetrachlorophthalide, 3,3-bis [1- (4-pyrrolidinophenyl) -1- (4-methoxyphenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3- [1,1-di (1-ethyl-2-methylindole-3-yl) ethylene-2-yl] -3- (4-diethylaminophenyl) ) Phenylide, 3- [1,1-di (1-ethyl-2-methylindol-3-yl) ethylene-2-yl] -3- (4-N-ethyl-N-phenylaminophenyl) phthalide, 3 -(2-ethoxy-4-diethylaminophenyl) -3- (1-n-octyl-2-methylindole-3-yl) -phthalide, 3,3-bis (1-n-octyl-2-methylindole-) Phenylides such as 3-yl) -phthalide, 3- (2-methyl-4-diethylaminophenyl) -3- (1-n-octyl-2-methylindole-3-yl) -phthalide,

4,4-Bis-dimethylaminobenzhydrinbenzyl ether, N-halophenyl-leucooramine, N-2,4,5-trichlorophenylleucooramine, rhodamine-B-anilinolactam, rhodamine- (4-nitroanilino) ) Lactam, Rhodamine-B- (4-chloroanilino) lactam, 3,7-bis (diethylamino) -10-benzoylphenoxazine, benzoyl leucomethylene blue, 4-nitrobenzoyl methylene blue,

3,6-Dimethoxyfluorane, 3-dimethylamino-7-methoxyfluorane, 3-diethylamino-6-methoxyfluorane, 3-diethylamino-7-methoxyfluorane, 3-diethylamino-7-chlorofluorine, 3 -Diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-N-cyclohexyl-Nn-butylamino-7-methylfluorane, 3-diethylamino-7- Dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7-di-n-hexylaminofluorane, 3-diethylamino-7-anilinofluorane, 3-diethylamino-7- ( 2'-fluorophenylamino) fluorane, 3-diethylamino-7- (2'-chlorophenylamino) fluorane, 3-diethylamino-7- (3'-chlorophenylamino) fluorane, 3-diethylamino-7- (2', 3) '-Dichlorophenylamino) fluorane, 3-diethylamino-7- (3'-trifluoromethylphenylamino) fluorane, 3-di-n-butylamino-7- (2'-fluorophenylamino) fluorane, 3-di- n-Butylamino-7- (2'-chlorophenylamino) fluorane, 3-N-isopentyl-N-ethylamino-7- (2'-chlorophenylamino) fluorane,

3-Nn-hexyl-N-ethylamino-7- (2'-chlorophenylamino) fluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-di-n-butylamino-6- Chloro-7-anilinofluorane, 3-diethylamino-6-methoxy-7-anilinofluorane, 3-di-n-butylamino-6-ethoxy-7-anilinofluorane, 3-pyrrolidino-6- Methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3-morpholino-6-methyl-7-anilinofluoran, 3-dimethylamino-6-methyl-7- Anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di-n-butylamino-6-methyl-7-anilinofluorane, 3-di-n-pentylamino-6 -Methyl-7-anilinofluorane, 3-N-ethyl-N-methylamino-6-methyl-7-anilinofluorane, 3-Nn-propyl-N-methylamino-6-methyl-7 -Anilinofluorane, 3-Nn-propyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-Nn-butyl-N-methylamino-6-methyl-7-ani Renofluorane, 3-Nn-butyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isopentyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-Nn- Hexyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn- Propylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-butylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-hexylamino -6-Methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-octylamino-6-methyl-7-anilinofluorane,

3-N- (2'-methoxyethyl) -N-methylamino-6-methyl-7-anilinofluorane, 3-N- (2'-methoxyethyl) -N-ethylamino-6-methyl-7 -Anilinofluorane, 3-N- (2'-methoxyethyl) -N-isobutylamino-6-methyl-7-anilinofluorane, 3-N- (2'-ethoxyethyl) -N-methylamino -6-Methyl-7-anilinofluorane, 3-N- (2'-ethoxyethyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (3'-methoxypropyl) ) -N-Methylamino-6-methyl-7-anilinofluorane, 3-N- (3'-methoxypropyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (3'-ethoxypropyl) -N-methylamino-6-methyl-7-anilinofluorane, 3-N- (3'-ethoxypropyl) -N-ethylamino-6-methyl-7-anilinoflu Oran, 3-N- (2'-tetrahydrofurfuryl) -N-ethylamino-6-methyl-7-anilinofluoran, 3-N- (4'-methylphenyl) -N-ethylamino-6- Methyl-7-anilinofluorane, 3-diethylamino-6-ethyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- (3'-methylphenylamino) fluorane, 3-diethylamino-6- Methyl-7- (2', 6'-dimethylphenylamino) fluorane, 3-di-n-butylamino-6-methyl-7- (2', 6'-dimethylphenylamino) fluorane, 3-di-n -Butylamino-7- (2', 6'-dimethylphenylamino) fluorane, 2,2-bis [4'-(3-N-cyclohexyl-N-methylamino-6-methylfluorane) -7-yl Aminophenyl] propane, 3- [4'-(4-phenylaminophenyl) aminophenyl] amino-6-methyl-7-chlorofluorane, 3- [4'-(dimethylaminophenyl)] amino-5,7 -Fluorans such as dimethylfluorane,

3- (2-Methyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-n-propoxycarbonylamino-4-di-n) -Propylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-methylamino-4-di-n-propylaminophenyl) -3- (1) -Ethyl-2-methylindole-3-yl) -4-azaphthalide, 3- (2-methyl-4-din-hexylaminophenyl) -3- (1-n-octyl-2-methylindole-3-) Il) -4,7-diazaphthalide, 3,3-bis (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis (1-n-octyl-2-methylindole-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindole-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) ) -3- (1-octyl-2-methylindole-3-yl) -4 or 7-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindole-) 3-Il) -4 or 7-azaphthalide, 3- (2-hexyloxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindole-3-yl) -4 or 7-azaphthalide, 3- (2-Ethyl-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindole-3-yl) -4 or 7-azaphthalide, 3- (2-butoxy-4-diethylaminophenyl) -3-( 1-Ethyl-2-phenylindole-3-yl) -4 or 7-azaphthalide, 3-methyl-spiro-dinaphthopylan, 3-ethyl-spiro-dinaftopylan, 3-phenyl-spiro-dinaftopyrane, 3-benzyl-spiro- Dinaftpyran, 3-methyl-naphtho- (3-methoxybenzo) spiropyrane, 3-propyl-spiro-dibenzopyran-3,6-bis (dimethylamino) fluorene-9-spiryl-3'-(6'-dimethylamino) Phtalides, phthalides such as 3,6-bis (diethylamino) fluorene-9-spiro-3'-(6'-dimethylamino) phthalide,

In addition, 2'-anilino-6'-(N-ethyl-N-isopentyl) amino-3'-methylspiro [isobenzofuran-1 (3H), 9'-(9H) xanthen-3-one, 2'-anilino -6'-(N-ethyl-N- (4-methylphenyl)) amino-3'-methylspiro [isobenzofuran-1 (3H), 9'-(9H) xanthene] -3-one, 3'-N , N-Dibenzylamino-6'-N, N-diethylaminospiro [isobenzofuran-1 (3H), 9'-(9H) xanthene] -3-one, 2'-(N-methyl-N-phenyl) Amino-6'-(N-ethyl-N- (4-methylphenyl)) aminospiro [isobenzofuran-1 (3H), 9'-(9H) xanthene] -3-one and the like can be mentioned.

Among them, the acid color former used in the present disclosure is at least one compound selected from the group consisting of a spiropyran compound, a spirooxazine compound, a spirolactone compound, and a spirolactam compound from the viewpoint of color development. preferable.
The hue of the dye after color development is preferably green, blue or black from the viewpoint of visibility.

Further, the acid color former is preferably a leuco dye from the viewpoint of color development and visibility of the exposed portion.
The leuco dye is not particularly limited as long as it has a leuco structure, but preferably has a spiro structure, and more preferably has a spirolactone ring structure.
Further, the leuco dye is preferably a leuco dye having a phthalide structure or a fluorane structure from the viewpoint of color development and visibility of the exposed portion.
Further, the leuco dye having a phthalide structure or a fluorine structure is a compound represented by any of the following formulas (Le-1) to (Le-3) from the viewpoint of color development and visibility of the exposed portion. It is more preferable that the compound is represented by the following formula (Le-2).

Wherein (Le-1) ~ formula (Le-3), in each ERG independently represents an electron donating _group, each X 1 ~ _{X 4} independently represent a hydrogen atom, a halogen atom or a dialkyl anilino group , X ₅ to X ₁₀ independently represent a hydrogen atom, a halogen atom or a monovalent organic group, Y ₁ and Y ₂ independently represent C or N, and when Y ₁ is N, If X ₁ does not exist and Y ₂ is N, then X ₄ does not exist, Ra ₁ represents a hydrogen atom, an alkyl group or an alkoxy group, and Rb ₁ to Rb ₄ are independent hydrogen atoms. , Alkyl group or aryl group.

The electron donating groups in the ERGs of the formulas (Le-1) to (Le-3) include amino groups, alkylamino groups, arylamino groups, and dialkylaminos from the viewpoint of color development and visibility of the exposed area. A group, a monoalkyl monoarylamino group, a diarylamino group, an alkoxy group, an aryloxy group, or an alkyl group is preferable, and an amino group, an alkylamino group, an arylamino group, a dialkylamino group, or a monoalkyl monoarylamino group. , A diallylamino group, an alkoxy group, or an aryloxy group, more preferably an arylamino group, a monoalkyl monoarylamino group, or a diarylamino group, further preferably an arylamino group or a monoalkyl group. It is particularly preferably a monoarylamino group.
Formula (Le-1) ~ formula each _X 1 ~ _{X 4} is in (Le-3) independently chromogenic, and, from the viewpoint of visibility of the exposure unit, a hydrogen atom, or, be a chlorine atom preferably , A hydrogen atom is more preferable.
_{X 5} to X ₁₀ in the formula (Le-2) or the formula (Le-3) are independently, from the viewpoint of color development and visibility of the exposed part, hydrogen atom, halogen atom, alkyl group, aryl group, respectively. Amino group, alkylamino group, arylamino group, dialkylamino group, monoalkyl monoarylamino group, diarylamino group, hydroxy group, alkoxy group, aryloxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group or cyano group. It is preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, or an aryloxy group, and more preferably a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. , A hydrogen atom is particularly preferable.
_{It is preferable that at least one of Y 1} and Y ₂ in the formulas (Le-1) to (Le-3) is C from the viewpoint of color development and visibility of the exposed portion, and Y ₁ and Y are Y. It is more preferable that both of _{2 are C.}
_{Ra 1} in the formulas (Le-1) to (Le-3) is preferably an alkyl group or an alkoxy group, and more preferably an alkoxy group, from the viewpoint of color development and visibility of the exposed portion. It is preferably a methoxy group, and particularly preferably a methoxy group.
_{Rb 1} to Rb ₄ in the formulas (Le-1) to (Le-3) are each independently preferably a hydrogen atom or an alkyl group from the viewpoint of color development and visibility of the exposed part, and are alkyl. It is more preferably a group, and particularly preferably a methyl group.

Further, the leuco dye having the phthalide structure or the fluorane structure has the following formulas (Le-4) to the following formulas (Le-4) from the viewpoint of color development and visibility of the exposed portion. It is more preferably a compound represented by any of Le-6), and further preferably a compound represented by the following formula (Le-5).

Wherein (Le-4) ~ formula (Le-6), in each ERG independently represents an electron donating _group, each X 1 ~ _{X 4} independently represent a hydrogen atom, a halogen atom or a dialkyl anilino group , Y ₁ and Y ₂ independently represent C or N, and if Y ₁ is N, then X ₁ does not exist, and if Y ₂ is N, then X ₄ does not exist and Ra. ₁ represents a hydrogen atom, an alkyl group or an alkoxy group, and Rb ₁ to Rb ₄ independently represent a hydrogen atom, an alkyl group or an aryl group.

_ERG in formula (Le-4) ~ formula _{(Le-6), X 1} ~ X 4, Y 1, Y 2, Ra 1 and, _respectively Rb 1 ~ Rb ₄ are formula (Le-1) ~ formula ( le-3) _ERG _{_{in, X 1 ~ X 4, Y}} 1, Y 2, Ra 1 and have _the same meanings as Rb 1 ~ Rb _4, preferable embodiments thereof are also the same.

Further, the leuco dye having the phthalide structure or the fluorane structure has the following formulas (Le-7) to the following formulas (Le-7) to the leuco dye having the phthalide structure or the fluorane structure from the viewpoint of color development and visibility of the exposed portion. It is more preferably a compound represented by any of Le-9), and particularly preferably a compound represented by the following formula (Le-8).

Wherein (Le-7) ~ formula _(Le-9), each X 1 ~ _{X 4} is independently a hydrogen atom, a halogen atom or a dialkyl anilino group, _{Y 1} and _{Y 2} are each independently, C or Representing N, when Y ₁ is N, X ₁ does not exist, when Y ₂ is N, X ₄ does not exist, and Ra ₁ to Ra ₄ independently represent a hydrogen atom and an alkyl. Represents a group or an alkoxy group, Rb ₁ to Rb ₄ independently represent a hydrogen atom, an alkyl group or an aryl group, and Rc ₁ and Rc ₂ each independently represent an aryl group.

_X 1 _- X 4 in formula (Le-7) to Formula (Le-9), _{Y 1} and _{Y 2} has the formula _{_{(Le-1) X 1 ~}} X 4 in ~ formula (Le-3), _{Y 1} and It has the same meaning as Y ₂ , and the preferred embodiment is also the same.
_{Ra 1} to Ra ₄ in the formulas (Le-7) to (Le-9) are each independently preferably an alkyl group or an alkoxy group from the viewpoint of color development and visibility of the exposed portion, and are alkoxy groups. It is more preferably a group, and particularly preferably a methoxy group.
_{Rb 1} to Rb ₄ in the formulas (Le-7) to (Le-9) are independently each of a hydrogen atom, an alkyl group, an alkyl group or an alkoxy from the viewpoint of color development and visibility of the exposed part. The group is preferably an aryl group substituted, more preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom or a methyl group.
_{Each of Rc 1} and Rc ₂ in the formula (Le-8) is preferably a phenyl group or an alkylphenyl group, and is preferably a phenyl group, independently from the viewpoint of color development and visibility of the exposed portion. Is more preferable.
Further, in the formula (Le-8), from the viewpoint of color development and visibility of the exposed portion, it is preferable that _{X 1} to X ₄ are hydrogen atoms and Y ₁ and Y _{2 are C.}
Further, in the formula (Le-8), from the viewpoint of color development and visibility of the exposed portion, Rb ₁ and Rb ₂ are independently substituted with hydrogen atoms, alkyl groups, alkyl groups or alkoxy groups, respectively. It is preferably an aryl group, more preferably a hydrogen atom or an alkyl group.

The alkyl group in the formulas (Le-1) to (Le-9) may be linear, have a branch, or have a ring structure.
Further, the number of carbon atoms of the alkyl group in the formulas (Le-1) to (Le-9) is preferably 1 to 20, more preferably 1 to 8, and further preferably 1 to 4. It is preferably 1 or 2, and particularly preferably 1.
The number of carbon atoms of the aryl group in the formulas (Le-1) to (Le-9) is preferably 6 to 20, more preferably 6 to 10, and particularly preferably 6 to 8.

Further, each group such as a monovalent organic group, an alkyl group, an aryl group, a dialkylanilino group, an alkylamino group and an alkoxy group in the formulas (Le-1) to (Le-9) has a substituent. May be. Substituents include alkyl groups, aryl groups, halogen atoms, amino groups, alkylamino groups, arylamino groups, dialkylamino groups, monoalkyl monoarylamino groups, diallylamino groups, hydroxy groups, alkoxy groups, aryloxy groups and acyls. Examples thereof include a group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a cyano group. Further, these substituents may be further substituted with these substituents.

Examples of the leuco dye having a phthalide structure or a fluorine structure that are preferably used include the following compounds.

Further, examples of the leuco dye preferably used include the following compounds.

It is also possible to use commercially available products as the acid color former, ETAC, RED500, RED520, CVL, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, BLUE220, H. -3035, BLUE203, ATP, H-1046, H-2114 (all manufactured by Fukui Yamada Chemical Industry Co., Ltd.), ORANGE-DCF, Vermilion-DCF, PINK-DCF, RED-DCF, BLMB, CVL, GREEN-DCF , TH-107 (all manufactured by Hodogaya Chemical Co., Ltd.), ODB, ODB-2, ODB-4, ODB-250, ODB-BlackXV, Blue-63, Blue-502, GN-169, GN-2, Green -118, Red-40, Red-8 (all manufactured by Yamamoto Kasei Co., Ltd.), crystal violet lactone (manufactured by Tokyo Chemical Industry Co., Ltd.) and the like. Among these commercially available products, ETAC, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, H-3035, ATP, H-1046, H-2114, GREEN-DCF, Blue-63. , GN-169, and crystal violet lactone are preferable because the film to be formed has a good visible light absorption rate.

These acid color formers may be used alone or in combination of two or more.
The content of the acid color former is preferably 0.5% by mass to 10% by mass, and more preferably 1% by mass to 5% by mass, based on the total mass of the image recording layer.

-Chain transfer agent-
The image recording layer used in the present disclosure may contain a chain transfer agent. The chain transfer agent contributes to the improvement of printing durability in the lithographic printing 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 contain only one type or a combination of two or more types.
The content of the chain transfer agent is preferably 0.01% by mass to 50% by mass, more preferably 0.05% by mass to 40% by mass, and 0.1% by mass to 30% by mass with respect to the total mass of the image recording layer. % Is more preferable.

-Fat sensitive agent-
The image recording layer may contain a fat-sensing agent such as a phosphonium compound, a nitrogen-containing small molecule compound, and an ammonium group-containing polymer in order to improve the meat-forming property. In particular, when the protective layer contains an inorganic layered compound, these compounds function as a surface coating agent for the inorganic layered compound, and it is possible to suppress a decrease in inking property during printing due to the inorganic layered compound.
As the fat sensitive 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 (hexafluorophosphine), and 1,7-bis (tri). Examples thereof include phenylphosphonio) heptane = sulfate, 1,9-bis (triphenylphosphonio) nonane = naphthalene-2,7-disulfonate and the like.

Examples of nitrogen-containing small molecule compounds 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 = hexafluorophosphate. 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 mol% to 80 mol% of a (meth) acrylate having an ammonium group in the side chain as a copolymerization component is preferable. Specific examples include the polymers described in paragraphs 0008-0105 of JP2009-208458A.

The ammonium salt-containing polymer preferably has a reduction specific viscosity (unit: ml / g) value 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. Is more preferable, and 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) ethyl methacrylate = p-toluenesulfonate / hexyl methacrylate copolymer (molar ratio 30/70, Mw 45,000)
(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-methacryloyloxypropyl methacrylate copolymer (molar ratio 15/80/5, Mw 65,000)

The content of the oil-sensitive agent is preferably 0.01% by mass to 30.0% by mass, more preferably 0.1% by mass to 15.0% by mass, and 1% by mass with respect to the total mass of the image recording layer. % To 10% by mass is more preferable.

-Other ingredients-
The image recording layer may contain a surfactant, a polymerization inhibitor, a higher fatty acid derivative, a plasticizer, an inorganic layered compound and the like as other components. Specifically, the description in paragraphs 0114 to 0159 of Japanese Patent Application Laid-Open No. 2008-284817 can be referred to.

-Formation of image recording layer-
As described in paragraphs 0142 to 0143 of Japanese Patent Application Laid-Open No. 2008-195018, for example, the image recording layer in the lithographic printing plate original plate according to the present disclosure is coated by dispersing or dissolving each of the above-mentioned necessary components in a known solvent. It can be formed by preparing a liquid, applying the coating liquid on the support by a known method such as coating with a bar coater, and drying.
As the solvent, a known solvent can be used. Specifically, for example, water, acetone, methyl ethyl ketone (2-butanone), cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, Propylene glycol monoethyl ether, acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 1-methoxy-2-propanol, 3- Methoxy-1-propanol, methoxymethoxyethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethyl Examples thereof include formamide, dimethylsulfoxide, γ-butyrolactone, methyl lactate, ethyl lactate and the like. The solvent may be used alone or in combination of two or more. The solid content concentration in the coating liquid is preferably about 1 to 50% by mass.
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, 0.3 g / m ² to 3.0 g / m ² is preferred.

<Support>
The support in the lithographic printing plate original plate according to the present disclosure can be appropriately selected from known hydrophilic supports for lithographic printing plate original plates and used.
As the support, an aluminum support is preferable.
As the aluminum support, an aluminum support having a hydrophilic surface (hereinafter, also referred to as “hydrophilic aluminum support”) is preferable.
Further, as the support, a hydrophilic support is preferably mentioned.
The aluminum support in the lithographic printing plate original according to the present disclosure has a contact angle with water on the surface of the aluminum support on the image recording layer side by the aerial water droplet method of 110 ° or less from the viewpoint of suppressing scratches and stains. It is more preferably 90 ° or less, further preferably 80 ° or less, further preferably 50 ° or less, particularly preferably 30 ° or less, and particularly preferably 20 ° or less. Is more particularly preferable, and 10 ° or less is most preferable.

In the present disclosure, the contact angle with water by the aerial water droplet method on the surface of the aluminum support on the image recording layer side shall be measured by the following method.
The plate printing plate original plate is immersed in a solvent capable of removing the image recording layer (for example, the solvent used in the coating liquid for the image recording layer), the image recording layer is scraped off at least one of the sponge and cotton, and the image recording layer is used as a solvent. The surface of the aluminum support is exposed by dissolving in it.
The contact angle with water on the surface of the exposed aluminum support on the image recording layer side is measured on the surface at 25 ° C. by a fully automatic contact angle meter (for example, DM-501 manufactured by Kyowa Surface Chemical Co., Ltd.) as a measuring device. It is measured as the contact angle of water droplets (after 0.2 seconds).

As the aluminum support in the present disclosure, an aluminum plate that has been roughened and anodized by a known method is preferable. That is, the aluminum support in the present disclosure preferably has an aluminum plate and an aluminum anodic oxide film arranged on the aluminum plate.

An example of a preferred embodiment of the aluminum support used in the present disclosure (the aluminum support according to this example is also referred to as “support (1)”) is shown below.
That is, the support (1) has an aluminum plate and an anodic oxide film of aluminum arranged on the aluminum plate, and the anodic oxide film is located closer to the image recording layer than the aluminum plate. The anodic oxide film has micropores extending in the depth direction from the surface on the image recording layer side, and the average diameter of the micropores on the surface of the anodic oxide film is more than 10 nm and 100 nm or less, and the anodic oxidation. The value of the brightness L ^* ^{in the L *} a ^* b ^* color system of the surface of the film on the image recording layer side is 70 to 100.

FIG. 3 is a schematic cross-sectional view of an embodiment of the aluminum support 12a.
The aluminum support 12a has a laminated structure in which an aluminum plate 18 and an aluminum anodic oxide film 20a (hereinafter, also simply referred to as “anodized film 20a”) are laminated in this order. The anodic oxide film 20a in the aluminum support 12a is located closer to the image recording layer than the aluminum plate 18. That is, it is preferable that the planographic printing plate original plate according to the present disclosure has at least an anodic oxide film, an image recording layer, and a water-soluble resin layer on an aluminum plate in this order.

-Anodized film-
Hereinafter, preferred embodiments of the anodic oxide coating 20a will be described.
The anodic oxide film 20a is a film formed on the surface of the aluminum plate 18 by anodization treatment, and this film is extremely fine micropores 22a which are substantially perpendicular to the surface of the film and are uniformly distributed to each individual. Has. The micropore 22a extends from the surface of the anodic oxide film 20a on the image recording layer side (the surface of the anodic oxide film 20a on the side opposite to the aluminum plate 18 side) along the thickness direction (aluminum plate 18 side).

The average diameter (average opening diameter) of the micropores 22a in the anodic oxide film 20a on the surface of the anodic oxide film is preferably more than 10 nm and 100 nm or less. Among them, from the viewpoint of the balance between printing resistance, stain resistance, and image visibility, 15 nm to 60 nm is more preferable, 20 nm to 50 nm is further preferable, and 25 nm to 40 nm is particularly preferable. The diameter inside the pores may be wider or narrower than the surface layer.
If the average diameter exceeds 10 nm, the printing resistance and image visibility are further excellent. Further, when the average diameter is 100 nm or less, the printing durability is further excellent.
The average diameter of the micropores 22a is 400 nm × 600 nm in the four images obtained by observing the surface of the anodized film 20a with a field emission scanning electron microscope (FE-SEM) at a magnification of 150,000. The diameter (diameter) of the microscopes existing in the range of is measured at 50 points and calculated as an arithmetic mean value.
If the shape of the micropore 22a is not circular, the diameter equivalent to the circle is used. The "circle equivalent diameter" is the diameter of a circle when the shape of the opening is assumed to be a circle having the same projected area as the projected area of the opening.

The depth of the micropore 22a is not particularly limited, but is preferably 10 nm to 3,000 nm, more preferably 50 nm to 2,000 nm, and even more preferably 300 nm to 1,600 nm.
The depth is an average value obtained by taking a photograph (150,000 times) of the cross section of the anodic oxide film 20a and measuring the depths of 25 or more micropores 22a.

The shape of the micropore 22a is not particularly limited, and in FIG. 1, it is a substantially straight tubular (substantially cylindrical) shape, but it may be a conical shape whose diameter decreases in the depth direction (thickness direction). The shape of the bottom of the micropore 22a is not particularly limited, and may be curved (convex) or flat.

^{The value of L *} a ^* b ^* ^{lightness L *} in the color system of the surface of the aluminum support 12a on the image recording layer side (the surface of the anodic oxide film 20a on the image recording layer side) is preferably 70 to 100. .. Among them, 75 to 100 is preferable, and 75 to 90 is more preferable, in that the balance between printing resistance and image visibility is more excellent.
The brightness L ^* is measured using a color difference meter Specro Eye manufactured by X-Rite Co., Ltd.

In the support (1), the micropore communicates with the large-diameter hole extending from the surface of the anodic oxide film to a depth of 10 nm to 1,000 nm and the bottom of the large-diameter hole, and is deep from the communication position. It is composed of a small-diameter hole extending from 20 nm to 2,000 nm, and the average diameter of the large-diameter hole on the surface of the anodic oxide film is 15 nm to 150 nm, and the average diameter of the small-diameter hole at the communication position. A mode in which the diameter is 13 nm or less (hereinafter, the support according to the above mode is also referred to as “support (2)”) is also preferably mentioned.
FIG. 4 is a schematic cross-sectional view of the aluminum support 12a according to an embodiment different from that shown in FIG.
In FIG. 4, the aluminum support 12b includes an aluminum plate 18 and an anodic oxide film 20b having a micropore 22b composed of a large-diameter hole portion 24 and a small-diameter hole portion 26.
The micropores 22b in the anodic oxide film 20b communicate with the large-diameter hole portion 24 extending from the surface of the anodic oxide film to a position at a depth of 10 nm to 1000 nm (depth D: see FIG. 4) and the bottom of the large-diameter hole portion 24. It is composed of a small-diameter hole portion 26 extending from the communication position to a depth of 20 nm to 2,000 nm.
The large-diameter hole portion 24 and the small-diameter hole portion 26 will be described in detail below.

The average diameter of the large-diameter pore portion 24 on the surface of the anodic oxide film 20b is the same as the average diameter of the micropores 22a in the above-mentioned anodic oxide film 20a on the surface of the anodic oxide film, which is more than 10 nm and 100 nm or less, and the preferable range is also the same. Is.
The method for measuring the average diameter on the surface of the anodic oxide film 20b of the large-diameter hole portion 24 is the same as the method for measuring the average diameter on the surface of the anodic oxide film of the micropores 22a in the anodic oxide film 20a.

The bottom of the large-diameter hole portion 24 is located at a depth of 10 nm to 1,000 nm (hereinafter, also referred to as a depth D) from the surface of the anodic oxide film. That is, the large-diameter hole portion 24 is a hole portion extending from the surface of the anodic oxide film to a position of 10 nm to 1,000 nm in the depth direction (thickness direction). The depth is preferably 10 nm to 200 nm.
The depth is an average value obtained by taking a photograph (150,000 times) of the cross section of the anodic oxide film 20b, measuring the depths of 25 or more large-diameter hole portions 24, and averaging them.

The shape of the large-diameter hole portion 24 is not particularly limited, and examples thereof include a substantially straight tubular shape (substantially cylindrical) and a conical shape whose diameter decreases in the depth direction (thickness direction). preferable.

As shown in FIG. 4, the small-diameter hole portion 26 is a hole portion that communicates with the bottom portion of the large-diameter hole portion 24 and extends further in the depth direction (thickness direction) from the communication position.
The average diameter of the small-diameter hole portion 26 at the communication position is preferably 13 nm or less. Above all, 11 nm or less is preferable, and 10 nm or less is more preferable. The lower limit is not particularly limited, but it is often 5 nm or more.

The average diameter of the small-diameter pores 26 is as follows: The surface of the anodized film 20a is observed with N = 4 sheets by FE-SEM at a magnification of 150,000 times, and in the obtained 4 images, micropores existing in the range of 400 nm × 600 nm. The diameter (diameter) of the (small diameter hole) is measured and obtained as an arithmetic mean value. If the large-diameter hole is deep, the upper part of the anodic oxide film 20b (the region with the large-diameter hole) is cut (for example, cut with argon gas), and then the anodic oxide film 20b is cut. The surface may be observed with the above-mentioned FE-SEM to obtain the average diameter of the small-diameter holes.
If the shape of the small-diameter hole portion 26 is not circular, the diameter equivalent to a circle is used. The "circle equivalent diameter" is the diameter of a circle when the shape of the opening is assumed to be a circle having the same projected area as the projected area of the opening.

The bottom portion of the small-diameter hole portion 26 is located at a position extending 20 nm to 2,000 nm in the depth direction from the communication position with the large-diameter hole portion 24. In other words, the small-diameter hole portion 26 is a hole portion that extends further in the depth direction (thickness direction) from the communication position with the large-diameter hole portion 24, and the depth of the small-diameter hole portion 26 is 20 nm to 2,000 nm. .. The depth is preferably 500 nm to 2,000 nm.
The depth is an average value obtained by taking a photograph (50,000 times) of the cross section of the anodic oxide film 20b and measuring the depths of 25 or more small-diameter holes.

The shape of the small-diameter hole portion 26 is not particularly limited, and examples thereof include a substantially straight tubular shape (substantially cylindrical) and a conical shape whose diameter decreases in the depth direction, and a substantially straight tubular shape is preferable.

-Manufacturing method of aluminum support-
As a method for manufacturing the aluminum support used in the present disclosure, for example, a manufacturing method in which the following steps are sequentially performed is preferable.
-Roughening treatment step: Roughening treatment of aluminum plate-Anodizing treatment step: Anodizing the roughened aluminum plate-Pore wide treatment step: Anodizing obtained in the anodizing treatment step Step of bringing an aluminum plate having an oxide film into contact with an acid aqueous solution or an alkaline aqueous solution to increase the diameter of micropores in the anodized film The procedure of each step 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. This step is preferably carried out before the anodizing treatment step described later, but it may not be carried out in particular as long as the surface of the aluminum plate already has a preferable surface shape.

The roughening treatment may be carried out only by the electrochemical roughening treatment, but is carried out by combining the electrochemical roughening treatment with the mechanical roughening treatment and / or the chemical roughening treatment. You may.
When the mechanical roughening treatment and the electrochemical roughening treatment are combined, it is preferable to carry out the electrochemical roughening treatment after the mechanical roughening treatment.
The electrochemical roughening treatment is preferably carried out using direct current or alternating current in an aqueous solution mainly containing nitric acid or hydrochloric acid.
The method of mechanical roughening treatment is not particularly limited, and examples thereof include the methods described in Japanese Patent Publication No. 50-40047.
The chemical roughening treatment is also not particularly limited, and known methods can be mentioned.

After the mechanical roughening treatment, it is preferable to carry out the following chemical etching treatment.
The chemical etching treatment applied after the mechanical roughening treatment smoothes the uneven edges on the surface of the aluminum plate, prevents ink from getting caught during printing, and improves the stain resistance of the printing plate. , It is performed to remove unnecessary substances such as abrasive particles remaining on the surface.
Examples of the chemical etching treatment include etching with an acid and etching with an alkali, and as a method particularly excellent in terms of etching efficiency, a chemical etching treatment using an alkaline aqueous solution (hereinafter, also referred to as “alkali etching treatment”) can be mentioned. Be done.

The alkaline agent used in the alkaline aqueous solution is not particularly limited, and examples thereof include caustic soda, caustic potash, sodium metasilicate, sodium carbonate, sodium aluminate, and sodium gluconate.
The alkaline aqueous solution may contain aluminum ions.
The concentration of the alkaline agent in the alkaline aqueous solution is preferably 0.01% by mass or more, more preferably 3% by mass or more, and preferably 30% by mass or less.

When the alkaline etching treatment is performed, it is preferable to perform a chemical etching treatment (hereinafter, also referred to as "desmat treatment") using a low-temperature acidic aqueous solution in order to remove the product generated by the alkaline etching treatment.
The acid used in the acidic aqueous solution is not particularly limited, and examples thereof include sulfuric acid, nitric acid, and hydrochloric acid. The temperature of the acidic aqueous solution is preferably 20 ° C to 80 ° C.

As the roughening treatment step, a method in which the treatments shown in the A mode or the B mode are carried out in the order shown below is preferable.

~ A aspect ~
(2) Chemical etching treatment using an alkaline aqueous solution (first alkaline etching treatment)
(3) Chemical etching treatment using an acidic aqueous solution (first desmat treatment)
(4) Electrochemical roughening treatment using an aqueous solution mainly composed of nitric acid (first electrochemical roughening treatment)
(5) Chemical etching treatment using an alkaline aqueous solution (second alkaline etching treatment)
(6) Chemical etching treatment using an acidic aqueous solution (second desmat treatment)
(7) Electrochemical roughening treatment in an aqueous solution mainly composed of hydrochloric acid (second electrochemical roughening treatment)
(8) Chemical etching treatment using an alkaline aqueous solution (third alkaline etching treatment)
(9) Chemical etching treatment using an acidic aqueous solution (third desmat treatment)

~ B mode ~
(10) Chemical etching treatment using an alkaline aqueous solution (fourth alkaline etching treatment)
(11) Chemical etching treatment using an acidic aqueous solution (fourth desmat treatment)
(12) Electrochemical roughening treatment using an aqueous solution mainly composed of hydrochloric acid (third electrochemical roughening treatment)
(13) Chemical etching treatment using an alkaline aqueous solution (fifth alkaline etching treatment)
(14) Chemical etching treatment using an acidic aqueous solution (fifth desmat treatment)

If necessary, (1) mechanical roughening treatment may be carried out before the treatment of (2) of the above A aspect or before the treatment of (10) of the B aspect.

The amount of the aluminum plate dissolved in the first alkali etching treatment and the fourth alkali etching treatment ^{is preferably 0.5 g / m 2} to 30 g / m ^{2, and} more preferably 1.0 g / m ² to 20 g / m ² .

Examples of the nitric acid-based aqueous solution used in the first electrochemical roughening treatment in the A aspect include an aqueous solution used in the electrochemical roughening treatment using direct current or alternating current. For example, an aqueous solution obtained by adding aluminum nitrate, sodium nitrate, ammonium nitrate or the like to an aqueous nitric acid solution of 1 to 100 g / L can be mentioned.
As the aqueous solution mainly containing hydrochloric acid used in the second electrochemical roughening treatment in the A aspect and the third electrochemical roughening treatment in the B aspect, the electrochemical rough surface using ordinary direct current or alternating current is used. Examples thereof include an aqueous solution used for the chemical treatment. For example, an aqueous solution obtained by adding 0 g / L to 30 g / L of sulfuric acid to a 1 g / L to 100 g / L hydrochloric acid aqueous solution can be mentioned. Nitrate ions such as aluminum nitrate, sodium nitrate, and ammonium nitrate; hydrochloric acid ions such as aluminum chloride, sodium chloride, and ammonium chloride may be further added to this solution.

As the AC power supply waveform of the electrochemical roughening treatment, a sine wave, a square wave, a trapezoidal wave, a triangular wave, or the like can be used. The frequency is preferably 0.1 Hz to 250 Hz.
FIG. 5 is a graph showing an example of an alternating waveform current waveform diagram used in the electrochemical roughening process.
In FIG. 5, ta is the anode reaction time, ct is the cathode reaction time, tp is the time from 0 to the peak of the current, Ia is the peak current on the anode cycle side, and Ic is the peak current on the cathode cycle side. , AA is the current of the anode reaction of the aluminum plate, and CA is the current of the cathode reaction of the aluminum plate. In a trapezoidal wave, the time tp from 0 to the peak of the current is preferably 1 ms to 10 ms. The conditions for one cycle of AC used for electrochemical roughening are that the ratio ct / ta of the anode reaction time ta and the cathode reaction time ct of the aluminum plate is 1 to 20, and the amount of electricity Qc and the anode when the aluminum plate is the anode. It is preferable that the ratio Qc / Qa of the amount of electricity Qa at the time is in the range of 0.3 to 20 and the anode reaction time ta is in the range of 5 ms to 1,000 ms. The current density is the peak value of the trapezoidal wave, and is preferably ^{10 A / dm 2} to 200 A / dm ² for both the anode cycle side Ia and the cathode cycle side Ic of the current. Ic / Ia is preferably 0.3 to 20. The total amount of electricity furnished to anode reaction of the aluminum plate at the time the electrochemical graining is ^{completed, 25C / dm 2 ~ 1,000C /} dm 2 is preferred.

The apparatus shown in FIG. 6 can be used for electrochemical roughening using alternating current.
FIG. 6 is a side view showing an example of a radial cell in an electrochemical roughening treatment using alternating current.
In FIG. 6, 50 is a main electrolytic cell, 51 is an AC power supply, 52 is a radial drum roller, 53a and 53b are main poles, 54 is an electrolyte supply port, 55 is an electrolyte, 56 is a slit, and 57 is an electrolyte passage. 58 is an auxiliary anode, 60 is an auxiliary anode tank, and W is an aluminum plate. In FIG. 6, the arrow A1 indicates the supply direction of the electrolytic solution, and the arrow A2 indicates the discharge direction of the electrolytic solution. Is. When two or more electrolytic cells are used, the electrolysis conditions may be the same or different.
The aluminum plate W is wound around a radial drum roller 52 immersed in the main electrolytic cell 50 and is electrolyzed by the

main poles

53a and 53b connected to the AC power supply 51 during the transfer process. The electrolytic solution 55 is supplied from the electrolytic solution supply port 54 to the electrolytic solution passage 57 between the radial drum roller 52 and the

main poles

53a and 53b through the slit 56. The aluminum plate W treated in the main electrolytic cell 50 is then electrolyzed in the auxiliary anode tank 60. An auxiliary anode 58 is arranged to face the aluminum plate W in the auxiliary anode tank 60, and the electrolytic solution 55 is supplied so as to flow in the space between the auxiliary anode 58 and the aluminum plate W.

The amount of the aluminum plate dissolved in the second alkaline etching treatment ^{is preferably 1.0 g / m 2} or more, and more preferably 2.0 g / m ² to 10 g / m ^{2 in} that a predetermined printing plate original plate can be easily produced.

The amount of the aluminum plate dissolved in the third alkali etching treatment and the fourth alkali etching treatment is preferably ^{0.01 g / m 2} to 0.8 g / m ^{2 and 0.05 g in that a predetermined printing plate original plate can be easily produced.} / M ² to 0.3 g / m ² is more preferable.

In the chemical etching treatment (first to fifth desmat treatments) using an acidic aqueous solution, an acidic aqueous solution containing phosphoric acid, nitric acid, sulfuric acid, chromium acid, hydrochloric acid, or a mixed acid containing two or more of these acids is preferably used.
The acid concentration of the acidic aqueous solution is preferably 0.5% by mass to 60% by mass.

[Anodizing process]
The procedure of the anodizing treatment step is not particularly limited as long as the above-mentioned micropores can be obtained, and known methods can be mentioned.
In the anodizing treatment step, aqueous solutions of sulfuric acid, phosphoric acid, oxalic acid and the like can be used as the electrolytic bath. For example, the concentration of sulfuric acid is 100 g / L to 300 g / L.
The conditions for the anodic oxidation treatment are appropriately set depending on the electrolytic solution used. For example, the liquid temperature is 5 ° C. to 70 ° C. (preferably 10 ° C. to 60 ° C.), and the current density is 0.5 A / dm ² to 60 A / dm ^2. (Preferably 1 A / dm ² to 60 A / dm ² ), voltage 1 V to 100 V (preferably 5 V to 50 V), electrolysis time 1 second to 100 seconds (preferably 5 seconds to 60 seconds), and film amount 0.1 g. / M ² to 5 g / m ² (preferably 0.2 g / m ² to 3 g / m ² ).

[Pore wide processing]
The pore-wide treatment is a treatment (pore diameter enlargement treatment) for enlarging the diameter (pore diameter) of the micropores existing in the anodizing film formed by the above-mentioned anodizing treatment step.
The pore-wide treatment can be performed by bringing the aluminum plate obtained by the above-mentioned 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.

<Protective layer>
The planographic printing plate original plate according to the present disclosure preferably has a protective layer (sometimes referred to as an overcoat layer) on the image recording layer.

From the viewpoint of color development and color development over time, the protective layer preferably contains a color-developing compound having a group that cleaves by heat or infrared exposure.
A preferred embodiment of the color-developing compound having a group that cleaves by heat or infrared exposure in the protective layer is a preferred embodiment of the color-developing compound having a group that cleaves by heat or infrared exposure in the image recording layer, except for the following aspects. Is similar to.
The content of the color forming compound in the protective layer, edge soiling inhibitory chromogenic over time chromogenic, on-press development property, and, in view of chemical ^{resistance, 0.1mg / m 2 ~ 100mg /} m 2 It is preferably 1 mg / m ² to 50 mg / m ² , more preferably 5 mg / m ² to 40 mg / m ² .

Further, the protective layer preferably contains a support-adsorbing compound having a molecular weight of 1,000 or less from the viewpoint of edge stain suppression and on-machine developability.
The preferred embodiment of the support-adsorbing compound having a molecular weight of 1,000 or less in the protective layer is the same as the preferred embodiment of the support-adsorbing compound having a molecular weight of 1,000 or less in the image recording layer, except for the following aspects. ..
The content of the support-adsorbing compound in the protective layer, edge soiling inhibitory, and is preferably from the viewpoint of on-press ^{developability,} it is ^{0.1mg / m 2 ~ 100mg / m} 2, 1mg / m It is more preferably ² to 50 mg / m ² , and particularly preferably ^{5 mg / m 2} to 40 mg / m ^2.

The protective layer is not particularly limited, but a protective layer having a function of suppressing an image formation inhibitory reaction by blocking oxygen, a function of preventing scratches on the image recording layer, and a function of preventing ablation during high-illuminance laser exposure. Can be mentioned.

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. can. 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 oxygen blocking property. Inorganic laminar compound is a particle having a thin tabular shape, for example, natural mica, micas such as synthetic mica, wherein: talc represented by 3MgO · 4SiO · H 2 _O, teniolite, montmorillonite, saponite, hectorite 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. ] Can be mentioned as a group of mica such as natural mica and synthetic mica.

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 KMg _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 above 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 Å to 15 Å (1 Å = 0.1 nm), 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 this, 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 swell greatly with water. When a share is applied in that state, it easily cleaves and forms a stable sol in water. Swellable synthetic mica has a strong tendency to do so 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 hinder the smoothness of the coated surface and the transmission of active rays. 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 particles, which can be measured, for example, from a micrograph projection of the particles. The larger the aspect ratio, the greater the effect obtained.

The average major axis of the mica compound is preferably 0.3 μm to 20 μm, more preferably 0.5 μm to 10 μm, and particularly preferably 1 μm 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 nm to 50 nm and the surface size (major axis) is about 1 μm to 20 μm.

The content of the inorganic layered compound is preferably 1% by mass to 60% by mass, more preferably 3% by mass 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 particles for controlling the slipperiness of the surface. In addition, the oil-sensitive agent described in the image recording layer may be contained in the protective layer.

The protective layer is applied by a known method. The coating amount of the protective layer (solid content) is preferably from ^{^{0.01g / m 2 ~ 10g / m}} 2, more preferably ^{^{0.02g / m 2 ~ 3g / m}} 2, 0.02g / m 2 ~ 1g / m ² is particularly preferable.

<Undercoat layer>
The planographic printing plate original plate according to the present disclosure preferably has an undercoat layer (sometimes referred to as an intermediate layer) between the image recording layer and the support. The undercoat layer strengthens the adhesion between the support and the image recording layer in the exposed portion, and makes it easy for the image recording layer to peel off from the support in the unexposed portion, so that the developability is not impaired without impairing the printing resistance. Contributes to improving. Further, in the case of infrared laser exposure, the undercoat layer functions as a heat insulating layer, so that the heat generated by the exposure is diffused to the support to prevent the sensitivity from being lowered.

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. A polymer having an adsorptive group and a hydrophilic group and further having a crosslinkable group is preferable in order to improve the adhesion to the image recording layer. 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.
The adsorbable adsorptive group to the support surface, a phenolic hydroxyl group, a carboxyl _{_{_{group, -PO 3 H 2, -OPO 3}}} H 2, -CONHSO 2 -, - SO 2 NHSO 2 -, - is COCH 2 COCH ₃ 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 methacryl group, an acrylamide group, a methacrylamide 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 pair charge 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. 10-228679, and an ethylenic di-ethylene compound described in JP-A-2-304441. A phosphorus compound having a double bond reactive group is preferably used. 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 are 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 mmol to 10.0 mmol, more preferably 0.2 mmol to 5.5 mmol per 1 g of the polymer.
The weight average molecular weight (Mw) of the polymer used for the undercoat layer is preferably 5,000 or more, and more preferably 10,000 to 300,000.

[Hydrophilic compound]
The undercoat layer preferably contains a hydrophilic compound from the viewpoint of developability.
The hydrophilic compound is not particularly limited, and a known hydrophilic compound used for the undercoat layer can be used.
Further, the hydrophilic compound in the undercoat layer is preferably the support-adsorbing compound.
Preferred examples of the hydrophilic compound include phosphonic acids having an amino group such as carboxymethyl cellulose and dextrin, organic phosphonic acids, organic phosphoric acids, organic phosphinic acids, amino acids, and hydrochlorides of amines having a hydroxy group.
Further, as the hydrophilic compound, a compound having an amino group or a functional group having a polymerization prohibitive ability and a group interacting with the surface of the support (for example, 1,4-diazabicyclo [2.2.2] octane (DABCO)). , 2,3,5,6-tetrahydroxy-p-quinone, chloranyl, sulfophthalic acid, ethylenediaminetetraacetic acid (EDTA) or its salt, hydroxyethylethylenediaminetriacetic acid or its salt, dihydroxyethylethylenediaminediacetic acid or its salt, hydroxy Ethylenediaminediacetic acid or a salt thereof, etc.) are preferably mentioned.

The hydrophilic compound preferably contains a hydroxycarboxylic acid or a salt thereof from the viewpoint of suppressing scratches and stains.
Further, the hydrophilic compound, preferably a hydroxycarboxylic acid or a salt thereof, is preferably contained in the layer on the aluminum support from the viewpoint of suppressing scratches and stains. Further, the layer on the aluminum support is preferably a layer on the side where the image recording layer is formed, and is preferably a layer in contact with the aluminum support.
As the layer on the aluminum support, an undercoat layer or an image recording layer is preferably mentioned as a layer in contact with the aluminum support. Further, a layer other than the layer in contact with the aluminum support, for example, a protective layer or an image recording layer may contain a hydrophilic compound, preferably a hydroxycarboxylic acid or a salt thereof.
In the lithographic printing plate original plate according to the present disclosure, it is preferable that the image recording layer contains a hydroxycarboxylic acid or a salt thereof from the viewpoint of suppressing scratches and stains.
Further, in the lithographic printing plate original plate according to the present disclosure, an embodiment in which the surface of the aluminum support on the image recording layer side is surface-treated with a composition containing at least hydroxycarboxylic acid or a salt thereof (for example, an aqueous solution) is also preferably mentioned. Be done. In the above embodiment, at least a part of the treated hydroxycarboxylic acid or a salt thereof is detected in a state of being contained in a layer on the image recording layer side (for example, an image recording layer or an undercoat layer) in contact with an aluminum support. be able to.
By containing hydroxycarboxylic acid or a salt thereof in the layer on the image recording layer side in contact with the aluminum support such as the undercoat layer, the surface of the aluminum support on the image recording layer side can be made hydrophilic, and the aluminum support can also be made hydrophilic. The contact angle with water on the surface of the image recording layer side by the aerial water droplet method can be easily set to 110 ° or less, and the scratch and stain suppression property is excellent.

Hydroxycarboxylic acid is a general term for organic compounds having one or more carboxy groups and one or more hydroxy groups in one molecule, and is also called hydroxy acid, oxyic acid, oxycarboxylic acid, or alcoholic acid (). Iwanami Physics and Chemistry Dictionary 5th Edition, published by Iwanami Shoten Co., Ltd. (1998)).
The hydroxycarboxylic acid or a salt thereof is preferably represented by the following formula (HC).
R ^HC (OH) _mhc ( ^{COMM HC} ) _nhc type (HC)
In formula (HC), R ^HC represents an organic group having a mhc + nhc valence, M ^HC each independently represents a hydrogen atom, an alkali metal or onium, and mhc and nhc each independently represent an integer of 1 or more. When is 2 or more, M may be the same or different.

In the formula (HC), examples of the mhc + nhc valent organic group represented by R include a mhc + nhc valent hydrocarbon group. The hydrocarbon group may have a substituent and / or a linking group.
As the hydrocarbon group, a group having a mhc + nhc valence derived from an aliphatic hydrocarbon, for example, an alkylene group, an alcantryyl group, an alkanetetrayl group, an alcantyl group, an alkenylene group, an arcentryyl group, an alkentetrayl group. Mhc + nhc valent groups derived from aromatic hydrocarbons such as groups, alkenylpentyl groups, alkynylene groups, alkyntriyl groups, alkynetetrayl groups, alkynpentyl groups, etc., such as allylene groups, allenetriyl groups, allenes. Examples thereof include a tetrayl group and an arenepentile group. Examples of the substituent other than the hydroxyl group and the carboxyl group include an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group and the like. Specific examples of the substituent include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group and a hexadecyl group. Octadecyl group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, Cyclopentyl group, 2-norbornyl group, methoxymethyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, acetyloxymethyl group, benzoyloxymethyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1- Methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2- Butynyl group, 3-butynyl group, phenyl group, biphenyl group, naphthyl group, tolyl group, xsilyl group, mesityl group, cumenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group , Methoxycarbonylphenyl group, ethoxycarbonylphenyl group, phenoxycarbonylphenyl group and the like. The linking group is composed of at least one atom selected from the group consisting of hydrogen atom, carbon atom, oxygen atom, nitrogen atom, sulfur atom and halogen atom, and the number of atoms is preferably 1 to 50. Is. Specific examples thereof include an alkylene group, a substituted alkylene group, an arylene group and a substituted arylene group, and a plurality of these divalent groups are linked by any of an amide bond, an ether bond, a urethane bond, a urea bond and an ester bond. It may have an esterified structure.

^Examples of the alkali metal represented by MHC include lithium, sodium, potassium and the like, and sodium is particularly preferable. Examples of onium include ammonium, phosphonium, sulfonium and the like, and ammonium is particularly preferable.
Further, M ^HC, from the viewpoint of scratch stain inhibitory, preferably an alkali metal or an onium, and more preferably an alkali metal.
The total number of mhc and nhc is preferably 3 or more, more preferably 3 to 8, and even more preferably 4 to 6.

The hydroxycarboxylic acid or a salt thereof preferably has a molecular weight of 600 or less, more preferably 500 or less, and particularly preferably 300 or less. The molecular weight is preferably 76 or more.
Specifically, the hydroxycarboxylic acid constituting the hydroxycarboxylic acid or the salt of the hydroxycarboxylic acid is gluconic acid, glycolic acid, lactic acid, tartron acid, hydroxybutyric acid (2-hydroxybutyric acid, 3-hydroxybutyric acid, γ-Hydroxybutyric acid, etc.), malic acid, tartaric acid, citramal acid, citric acid, isocitrate, leucic acid, mevalonic acid, pantoic acid, ricinolic acid, ricineraidic acid, cerebronic acid, quinic acid, shikimic acid, monohydroxybenzoic acid derivative (Salicylic acid, cleosortic acid (homosalicylic acid, hydroxy (methyl) benzoic acid), vanillic acid, syring acid, etc.), dihydroxybenzoic acid derivatives (pyrocatechuic acid, resorcylic acid, protocatechuic acid, gentidic acid, orceric acid, etc.), trihydroxy Benzoic acid derivatives (such as galvanic acid), phenylacetic acid derivatives (mandelic acid, benzylic acid, atrolactic acid, etc.), hydrosilicic acid derivatives (merilotoic acid, floretic acid, kumalic acid, umbellic acid, coffee acid, ferulic acid, cinnapic acid, etc.) Celebronic acid, carmic acid, etc.) and the like.

Among these, as the hydroxycarboxylic acid or the hydroxycarboxylic acid constituting the salt of the hydroxycarboxylic acid, a compound having two or more hydroxy groups is preferable from the viewpoint of suppressing scratches and stains, and a hydroxy group is preferable. A compound having 3 or more hydroxy groups is more preferable, a compound having 5 or more hydroxy groups is further preferable, and a compound having 5 to 8 hydroxy groups is particularly preferable.
Further, as a substance having one carboxy group and two or more hydroxy groups, gluconic acid or shikimic acid is preferable.
Citric acid or malic acid is preferable as having two or more carboxy groups and one hydroxy group.
Tartaric acid is preferable as having two or more carboxy groups and two or more hydroxy groups.
Among them, gluconic acid is particularly preferable as the hydroxycarboxylic acid.

The hydrophilic compound may be used alone or in combination of two or more.
When the undercoat layer contains a hydrophilic compound, preferably hydroxycarboxylic acid or a salt thereof, the content of the hydrophilic compound, preferably hydroxycarboxylic acid and its salt is 0.01% by mass or more based on the total mass of the undercoat layer. It is preferably 50% by mass, more preferably 0.1% by mass to 40% by mass, and particularly preferably 1.0% by mass to 30% by mass.

In addition to the above-mentioned compound for the undercoat layer, the undercoat layer may contain a chelating agent, a secondary or tertiary amine, a polymerization inhibitor, or the like in order to prevent stains over time.

The undercoat layer is applied by a known method. The coating amount (solid content) of the undercoat layer ^{is preferably 0.1 mg / m 2} to 100 mg / m ^{2, and} more preferably 1 mg / m ² to 30 mg / m ² .

<Edge hydrophilic layer>
From the viewpoint of suppressing edge stains, the lithographic printing plate original plate according to the present disclosure has a hydrophilic layer (also referred to as "edge hydrophilic layer") in a region within 1 cm from the edge of the surface of the lithographic printing plate original plate on the image recording layer side. It is preferable to have.
Even if the edge hydrophilic layer is provided at the end of at least one side of the surface of the lithographic printing plate original plate on the image recording layer side, the surface of the lithographic printing plate original plate on the image recording layer side has a quadrilateral shape. It may be provided at the ends of the four sides, but it is preferably provided within 1 cm from the ends of the two opposite sides of the surface of the planographic printing plate original plate on the image recording layer side.
The width of the edge hydrophilic layer is not particularly limited, but is preferably 1 mm to 50 mm.
Further, the lithographic printing plate original plate according to the present disclosure is preferably a lithographic printing plate original plate formed by cutting in the region where the edge hydrophilic layer is formed.
The edge hydrophilic layer may be provided as the outermost layer on the image recording layer side or between the layers, but is provided as the outermost layer on the image recording layer side from the viewpoint of suppressing edge stains. It is preferable to do so.

The edge hydrophilization layer preferably contains a hydrophilizing agent.
The hydrophilizing agent preferably contains a phosphoric acid compound and / or a phosphonic acid compound, and more preferably contains a phosphoric acid compound and / or a phosphonic acid compound and a surfactant as a hydrophilizing agent.
Further, in the above two embodiments, it is preferable to contain at least a phosphoric acid compound.

-Surfactant-
As the hydrophilic agent, it is preferable to use a surfactant.
Examples of the surfactant include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, but anionic surfactants, nonionic surfactants, and , At least one surfactant selected from the group consisting of amphoteric surfactants is preferred, anionic surfactants and / or nonionic surfactants are more preferred. According to the above aspect, a hydrophilic coating liquid having excellent coatability can be obtained.
Anionic and nonionic surfactants such as fluorine-based and silicone-based surfactants (typically, fluorine-based or silicone-based anionic or nonionic surfactants) are anionic or nonionic surfactants. Not preferable as an agent. When these surfactants are used, the coatability of the hydrophilic coating liquid is poor, which is not preferable.

Anionic surfactants include fatty acid salts, avietates, hydroxyalcan sulfonates, alkane sulfonates, dialkyl sulfosuccinates, linear alkylbenzene sulfonates, branched alkylbenzene sulfonates, alkylnaphthalene sulfonates. , Alkylphenoxypolyoxyethylenepropyl sulfonates, polyoxyethylenearyl ether sulfate esters, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodiums, N-alkyl sulfosuccinic acid monoamide disodium salts, Petroleum sulfonates, sulfated castor oil, sulfated cow fat oil, fatty acid alkyl ester sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfate Ester salts, polyoxyethylene styrylphenyl ether sulfate esters, alkyl phosphoric acid ester salts, polyoxyethylene alkyl ether phosphoric acid ester salts, polyoxyethylene alkyl phenyl ether phosphoric acid ester salts, partially saponified products of styrene-maleic anhydride copolymer , Partially saponified products of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensates and the like. Among these, dialkyl sulfosuccinates, alkyl sulfate esters, polyoxyethylene aryl ether sulfate esters, and alkylnaphthalene sulfonates are particularly preferably used.
Specifically, at least one anionic surfactant selected from the group consisting of anionic surfactants represented by the formula (IA) or the formula (IB) can be mentioned.

In the above formula (IA), R ₁ represents an alkyl group having 1 to 20 carbon atoms in a linear or branched chain; p represents 0, 1 or 2; Ar ₁ represents 6 to 10 carbon atoms. It represents an aryl group; q represents 1, 2 or _{3; M} ^{1 +} ^is, Na ^+, K +, representative of the Li ⁺ or _NH ^{4 +.} When p is 2, a plurality of R _1s may be the same or different from each other.
In the above formula (IB), R ₂ represents an alkyl group having 1 to 20 carbon atoms in a linear or branched chain; m represents 0, 1 or 2; Ar ₂ represents 6 to 10 carbon atoms. Represents an aryl group of; Y represents a single bond or an alkylene group having 1 to 10 carbon atoms; R ₃ represents a linear or branched alkylene group having 1 to 5 carbon atoms; n represents 1 to 100. It represents an _{integer; M} ^{2 +} ^is, Na ^+, K +, representative of the Li ⁺ or _NH ^{4 +.} When m is 2, the plurality of R _2s may be the same or different from each other; when n is 2 or more, the plurality of R _3s may be the same or different from each other.

In the above formulas (IA) and (IB), preferable examples of _{R 1} and R ₂ _{include CH 3} , C ₂ H ₅ , C ₃ H ₇ , or C ₄ H ₉ . Preferred examples of _{R 3} are each _{_{-CH 2 -, - CH 2 CH}} 2 -, or _{_{_{_{-CH 2 CH 2 CH 2 -,}}}} - CH 2 CH (CH 3) - and the like, more preferable examples Is -CH ₂ CH _2- . Further, p and m are preferably 0 or 1, and p is particularly preferably 0. Y is preferably a single bond. Further, n is preferably an integer of 1 to 20.

Specific examples of the compound represented by the formula (IA) or the formula (IB) include the following compounds.

The anionic surfactant is preferably a polymer compound (anionic polymer surfactant). According to the above aspect, the surface shape is excellent. The polymer compound is not particularly limited as long as it contains at least one anionic group as a hydrophilic group.
Examples of the anionic group include a sulfonic acid group, a sulfuric acid group and a carboxy group. Of these, a sulfonic acid group is preferable.
These anionic groups may constitute salts. The salt may be a salt with an inorganic cation or a salt with an organic cation.
Examples of the inorganic cation include lithium cation, sodium cation, potassium cation, calcium cation, magnesium cation and the like. Lithium cations, sodium cations and potassium cations are preferable, and sodium cations and potassium cations are more preferable.
The organic cation, ammonium (NH 4 _^+), quaternary ammonium, quaternary pyridinium, as a quaternary phosphonium and the like. Ammonium, quaternary ammonium, and quaternary pyridinium are preferable, and quaternary ammonium is more preferable.
The polymer compound includes a polymer of a monomer having an anionic group in the molecule, a polymer of a monomer having an anionic group in the molecule, and a common weight of one or more other monomers. Examples thereof include a polymer obtained by introducing a hydrophilic group into a polymer having no anionic group or a coalescence.
Examples of the monomer having an anionic group in the molecule include sulfonic acid groups such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, styrene sulfonic acid, sodium styrene sulfonate, and α-methyl styrene sulfonic acid. Olefin sulfonic acid such as styrene derivative, maleic anhydride, vinyl sulfonic acid, sodium allyl sulfonic acid, sodium metalyl sulfonic acid, sodium isoprene sulfonic acid, 3-vinyloxypropane sulfonic acid, 2-acrylamide-2-methyl propane sulfonic acid , A acrylamide derivatives having a sulfonic acid group such as 2-acrylamide-2-methylpropanesulfonic acid, (meth) acrylate derivatives such as 2-sulfoethylmethacrylate, dienesulfonic acid such as butadienesulfonic acid, naphthalenesulfonic acid and the like. Can be mentioned. Among the above monomers, a styrene derivative having a sulfonic acid group or an acrylamide derivative having a sulfonic acid group is preferable from the viewpoint of edge stain prevention performance, and sodium 4-styrene sulfonate or 2-acrylamide-2-methylpropane. Sodium sulfonate is more preferred.
The copolymer of the above-mentioned monomer having an anionic group and the monomer having a phosphoric acid ester group in the molecule described later is not an anionic surfactant but a phosphoric acid compound, and the copolymer described later is contained in the molecule described later. It is assumed that the copolymer with the monomer having a phosphonate ester group corresponds to a phosphonic acid compound instead of an anionic surfactant.
Examples of the polymer compound include partially saponified products of a styrene-maleic anhydride copolymer, formalin condensates of sulfonated aromatic compounds containing polynuclear aromatic compounds (particularly, sodium sodium phthalene sulfonic acid salt formalin condensates), and the like. Examples thereof include partially saponified products of ethylene-maleic anhydride copolymer, sodium salt of polyacrylic acid, sodium salt of polystyrene sulfonic acid, sodium salt of poly2-acrylamide-2-methylpropanesulfonic acid, and the like.
The weight average molecular weight of the polymer compound is preferably 2,000 to 1,000,000, more preferably 3,000 to 700,000, and particularly preferably 5,000 to 500,000.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene aryl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, and propylene glycol monofatty acid esters. Sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides , N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides and the like. Among them, polyoxyethylene aryl ethers, polyoxyethylene-polyoxypropylene block copolymers and the like are preferably used.

Examples of other surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene naphthyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, and polyoxyethylene stearyl ether, and poly. Polyoxyethylene alkyl esters such as oxyethylene stearate, sorbitan alkyl esters such as sorbitan monolaurate, sorbitan monostearate, sorbitan distearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, glycerol mono Nonionic surfactants such as monoglyceride alkyl esters such as stearate and glycerol monoolate are preferred.
Further, the nonionic surfactant is preferably a polymer compound. The weight average molecular weight of the polymer compound is preferably 2,000 to 1,000,000, more preferably 3,000 to 700,000, and particularly preferably 5,000 to 500,000.

Preferred examples of the nonionic surfactant include a surfactant represented by the following formula (II-A) and a surfactant represented by the formula (II-B).

(In the above formula (II-A), R ¹ represents a hydrogen atom or an alkyl group having 1 to 100 carbon atoms, n and m represent integers of 0 to 100, respectively, and both n and m are 0. There is no such thing.
In the above formula (II-B), R ² represents a hydrogen atom or an alkyl group having 1 to 100 carbon atoms, n and m represent integers of 0 to 100, respectively, and both n and m are 0. There is no such thing. )

Examples of the compound represented by the formula (II-A) include polyoxyethylene phenyl ether, polyoxyethylene methyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether and the like. Examples of the compound represented by the formula (II-B) include polyoxyethylene naphthyl ether, polyoxyethylene methyl naphthyl ether, polyoxyethylene octyl naphthyl ether, holioxyethylene nonyl naphthyl ether and the like.

In the compounds represented by the above formulas (II-A) and (II-B), the number of repeating units (n) of the polyoxyethylene chain is preferably 3 to 50, more preferably 5 to 30. The number of repeating units (m) of the polyoxypropylene chain is preferably 0 to 10, more preferably 0 to 5. The polyoxyethylene moiety and the polyoxypropylene moiety may be a random or block copolymer.
The nonionic aromatic ether-based surfactants represented by the above formulas (II-A) and (II-B) are used alone or in combination of two or more.
Specific examples of the compounds represented by the formulas (II-A) and (II-B) are shown below. The oxyethylene repeating unit and the oxypropylene repeating unit in the following exemplified compound "Y-5" may take any of a random bond and a block connection.

The edge hydrophilized layer preferably contains an amphoteric surfactant.
Examples of amphoteric surfactants include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, imidazolines and the like.
Further, the amphoteric surfactant is preferably a polymer compound (amphoteric surfactant polymer). As the amphoteric surfactant polymer, a sulfobetaine polymer, a carboxybetaine polymer, and a phosphobetaine polymer compound are preferable, and for example, the compounds described in JP2013-57747A and JP2012-194535A. Can be mentioned.

Of the above-mentioned surfactants, anionic surfactants having a high effect of promoting on-machine development are particularly preferably used, but two or more of these surfactants can be used in combination. For example, the combined use of two or more kinds of anionic surfactants different from each other or the combined use of an anionic surfactant and a nonionic surfactant is preferable.

It is preferable to use sodium naphthalene sulfonate, sodium alkylnaphthalene sulfonate, or polyoxyethylene aryl ether, and it is more preferable to use sodium naphthalene sulfonate or sodium t-butyl naphthalene sulfonate.

The content of the above-mentioned surfactant is not particularly limited, but is preferably 1% by mass to 95% by mass and 10% by mass to 90% by mass with respect to the total mass of the edge hydrophilized layer. Is more preferable, and 50% by mass to 90% by mass is further preferable. When the content of the surfactant is within the above range, the on-machine developability is promoted.

In addition, conventionally known cationic surfactants can be used in combination. Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, polyoxyalkylamine salts, polyethylene polyamine derivatives and the like.

-Phosphoric acid compound-
As the hydrophilic agent, it is preferable to use a phosphoric acid compound. Examples of phosphoric acid compounds include phosphoric acid, metaphosphoric acid, ammonium monophosphate, ammonium dibasic phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, potassium monophosphate, potassium dibasic phosphate, and tripolyphosphoric acid. Examples thereof include sodium, potassium pyrophosphate, and sodium hexametaphosphate. Of these, sodium dihydrogen phosphate, sodium monohydrogen phosphate, and sodium hexametaphosphate can be preferably used.
The content of the phosphoric acid compound is preferably 1% by mass to 80% by mass, more preferably 10% by mass to 50% by mass, based on the total mass of the edge hydrophilic layer.

As the phosphoric acid compound, a phosphoric acid monoester compound and a phosphoric acid diester compound can be used.
As the phosphoric acid compound, it is preferable to use a polymer compound, and a polymer compound having a phosphoric acid monoester group is more preferable. According to the above aspect, a hydrophilic coating liquid having excellent coatability on a support can be obtained.
The polymer compound does not include a polymer composed of one or more of the monomers having a phosphate ester group in the molecule, or one or more monomers containing a phosphate ester group and a phosphate ester group. Examples thereof include a copolymer with one or more kinds of monomers, a polymer in which a phosphoric acid ester group is later introduced into a polymer having no phosphoric acid ester group, and the like.
Examples of the monomer having a phosphate ester group include mono (2-methacryloyloxyethyl) acid phosphate, mono (2-methacryloyloxypolyoxyethylene glycol) acid phosphate, mono (2-acryloyloxyethyl) acid phosphate, and 3-. Chloro-2-acid phosphooxypropyl methacrylate, acid phosphooxypolyoxyethylene glycol monomethacrylate, acid phosphooxypolyoxypropylene glycol methacrylate, (meth) acryloyloxyethyl acid phosphate, (meth) acryloyloxypropyl acid phosphate, (meth) Examples thereof include acryloyloxy-2-hydroxypropyl acid phosphate, (meth) acryloyloxy-3-hydroxypropyl acid phosphate, (meth) acryloyloxy-3-chloro-2-hydroxypropyl acid phosphate, and allyl alcohol acid phosphate. Among the above-mentioned monomers, mono (2-acryloyloxyethyl) acid phosphate is preferably used from the viewpoint of edge stain prevention performance. Typical products include Light Ester P-1M (manufactured by Kyoei Chemical Co., Ltd.) and Hosmer PE (manufactured by Unichemical Co., Ltd.).

As the polymer compound, both a homopolymer and a copolymer of a monomer having a phosphoric acid ester group are used. Examples of the copolymer include a copolymer of a monomer having a phosphoric acid ester group and the above-mentioned monomer having an anionic group, a monomer having a phosphoric acid ester group, a phosphoric acid ester group and an anion. A copolymer with a monomer containing neither of the sex groups can be used.
In a preferred embodiment of the above polymer compound, the proportion of the monomer unit having a phosphate ester group in the molecule is 1 mol% to 100 mol%, more preferably 5 mol% to 100 mol%, still more preferably 10 mol% to. It is a 100 mol% copolymer or homopolymer.
As the monomer containing neither a phosphoric acid ester group nor an anionic group, a monomer having a hydrophilic group is preferable. Examples of the hydrophilic group include a hydroxy group, an alkylene oxide structure, an amino group, an ammonium group and an amide group. Among them, a hydroxy group, an alkylene oxide structure and an amide group are preferable, and an alkylene oxide having 2 or 3 carbon atoms is preferable. An alkylene oxide structure having 1 to 20 units is more preferable, and a polyethylene oxide structure having 2 to 10 ethylene oxide units is further preferable. For example, 2-hydroxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, poly (oxyethylene) methacrylate, N-isopropylacrylamide, acrylamide, and the like can be mentioned.
Further, as the phosphoric acid compound, it is preferable to use a copolymer of the monomer having a phosphoric acid ester group in the molecule and the monomer having the anionic group. According to the above aspect, a hydrophilic coating liquid having high coatability and high edge stain prevention performance can be obtained.
The ratio of the monomer unit having a phosphoric acid ester group in the molecule to the total monomer unit in the copolymer of the monomer having a phosphoric acid ester group in the molecule and the monomer having an anionic group is , 2 mol% to 99 mol%, more preferably 2 mol% to 80 mol%, further preferably 5 mol% to 70 mol%, and 5 mol% to 50 mol%. It is particularly preferable to have.
The weight average molecular weight of the polymer compound is preferably 5,000 to 1,000,000, more preferably 7,000 to 700,000, and particularly preferably 10,000 to 500,000.

-Phosphonate compound-
As the hydrophilic agent, it is preferable to use a phosphonic acid compound. Phosphonate compounds include ethylphosphonic acid, propylphosphonic acid, i-propylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, dodecylphosphonic acid, octadecylphosphonic acid, 2-hydroxyethylphosphonic acid and sodiums thereof. Alkylphosphonic acid monoalkyl esters such as salts or potassium salts, methyl methylphosphonates, methyl ethylphosphonates, and methyl 2-hydroxyethylphosphonates and arches such as sodium salts or potassium salts thereof, methylene diphosphonic acid, ethylene diphosphonic acid, etc. Examples thereof include range phosphonic acid and sodium or potassium salts thereof, polyvinyl phosphonic acid.
Above all, it is preferable to use polyvinylphosphonic acid.
The content of the phosphonic acid compound is preferably 1% by mass to 80% by mass, more preferably 10% by mass to 50% by mass, based on the total mass of the edge hydrophilized layer.

As the phosphonic acid compound, a polymer compound is preferable. According to the above aspect, a hydrophilic coating liquid having excellent coatability on a support can be obtained.
A preferable polymer compound as a phosphonic acid compound is a polymer composed of one or more monomers having a phosphonic acid group or a phosphonic acid monoester group in the molecule, or a phosphonic acid group or a phosphonic acid monoester, in addition to polyvinylphosphonic acid. Examples thereof include a copolymer with one or more monomers having an ester group and one or more monomers not containing a phosphonic acid group or a phosphonic acid monoester group.
Examples of the monomer having a phosphonic acid group include vinylphosphonic acid, ethylphosphonic acid monovinyl ester, acryloylaminomethylphosphonic acid, and 3-methacryloyloxypropylphosphonic acid.
As the polymer compound, both a homopolymer and a copolymer of a monomer having a phosphonic acid ester group are used. Examples of the copolymer include a copolymer of a monomer having a phosphonic acid ester group and the above-mentioned monomer having an anionic group, a monomer having a phosphoric acid ester group, a phosphoric acid ester group, and an anion. A copolymer with a monomer containing neither of the sex groups can be used.
As the monomer containing neither a phosphonic acid ester group nor an anionic group, a monomer having a hydrophilic group is preferable. Examples of the hydrophilic group include a hydroxy group, an alkylene oxide structure, an amino group, an ammonium group and an amide group. Among them, a hydroxy group, an alkylene oxide structure and an amide group are preferable, and an alkylene oxide having 2 or 3 carbon atoms is preferable. An alkylene oxide structure having 1 to 20 units is more preferable, and a polyethylene oxide structure having 2 to 10 ethylene oxide units is further preferable. For example, 2-hydroxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, poly (oxyethylene) methacrylate, N-isopropylacrylamide, acrylamide, and the like can be mentioned.
In a preferred embodiment of the above polymer compound, the proportion of the monomer unit having a phosphate ester group in the molecule is 1 mol% to 100 mol%, more preferably 3 mol% to 100 mol%, still more preferably 5 mol% to. It is a 100 mol% copolymer or homopolymer.
Further, as the phosphonic acid compound, a copolymer of the monomer having a phosphonic acid ester group in the molecule and the monomer having the anionic group can also be used. According to the above aspect, a hydrophilic coating liquid having high coatability and high edge stain prevention performance can be obtained, which is preferable.
The ratio of the monomer unit having a phosphonic acid ester group in the molecule to the total monomer unit in the copolymer of the monomer having a phosphonic acid ester group in the molecule and the monomer having an anionic group is , 2 mol% to 99 mol%, more preferably 2 mol% to 80 mol%, further preferably 5 mol% to 70 mol%, and 10 mol% to 50 mol%. It is particularly preferable to have.
The weight average molecular weight of the polymer compound is preferably 5,000 to 1,000,000, more preferably 7,000 to 700,000, and particularly preferably 10,000 to 500,000.

-Water-soluble resin-
The hydrophilic agent preferably contains a water-soluble resin.
Water-soluble resins include water-soluble resins classified as polysaccharides, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide and copolymers thereof, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer. , Styrene / maleic anhydride copolymer and the like.
Examples of polysaccharides include starch derivatives (eg, dextrin, enzymatically decomposed dextrin, hydroxypropylated starch, carboxymethylated starch, phosphate esterified starch, polyoxyalkylene grafted starch, cyclodextrin), celluloses (eg, carboxymethyl cellulose, carboxy). Ethyl cellulose, methyl cellulose, hydroxypropyl cellulose, methyl propyl cellulose, etc.), carrageenan, alginic acid, guar gum, locust bean gum, xanthan gum, arabic gum, soybean polysaccharide and the like can be mentioned.
Among them, starch derivatives such as dextrin and polyoxyalkylene grafted starch, gum arabic, carboxymethyl cellulose, soybean polysaccharide and the like are preferably used.

These water-soluble resins can be used in combination of two or more.
The content of the water-soluble resin can be preferably in the range of 5% by mass to 40% by mass, more preferably 10% by mass to 30% by mass, based on the total mass of the edge hydrophilized layer. Within this range, a hydrophilic protective film having excellent coatability can be obtained.

The above-mentioned hydrophilizing agent may be used alone, but it is preferable to use two or more kinds of hydrophilizing agents in combination, and it is more preferable to use one to four kinds of hydrophilizing agents in combination. Preferably, it is more preferable to use one to three kinds of hydrophilic agents in combination, and it is particularly preferable to use two kinds of hydrophilic agents in combination. When a plurality of hydrophilic agents are used in combination, surfactant is used. It is preferable to use the agent in combination with a phosphoric acid compound or a phosphonic acid compound, and more preferably to use an anionic surfactant in combination with a phosphoric acid compound or a phosphonic acid compound.
When one kind of hydrophilic agent is used alone, a copolymer of a monomer having a phosphoric acid ester group or a phosphonic acid ester group in the molecule and a monomer having an anionic group in the molecule is used. It is preferable to use a copolymer of a monomer having a phosphate ester group in the molecule and a monomer having an anionic group in the molecule, and it is more preferable to use a phosphoric acid ester group in the molecule. It is more preferable to use a copolymer of a monomer having a sulfonic acid group and a monomer having a sulfonic acid group in the molecule.

-Plasticizer-
The edge hydrophilic layer can contain a plasticizer.
Examples of the plasticizer include phthalates such as dibutylphthalate, diheptylphthalate, di-n-octylphthalate, di (2-ethylhexyl) phthalate, dinonylphthalate, didecylphthalate, dilaurylphthalate, and butylbenzylphthalate. Aliphatic dibasic acid esters such as dioctyl adipate, butyl glycol adipate, dioctyl azelate, dibutyl sebacate, di (2-ethylhexyl) sebacate, dioctyl sebacate, eg epoxidized triglycerides such as epoxidized soybean oil, eg Includes plasticizers having a freezing point of 15 ° C. or lower, such as phosphoric acid esters such as tricresyl phosphate, trioctyl phosphate, trischloroethyl phthalate, and benzoic acid esters such as benzyl benzoate.

Only one type of plasticizer may be used, or two or more types may be used in combination.
The content of the plasticizer is preferably more than 0% by mass and 10% by mass or less, and more preferably more than 0% by mass and 5% by mass or less with respect to the total mass of the edge hydrophilized layer.

-Other optional ingredients-
In addition to the above components, the edge hydrophilic layer can contain inorganic salts such as nitrates and sulfates, preservatives, antifoaming agents and the like.
Further, it is also preferable that the edge hydrophilic layer contains particles such as the above-mentioned microgel.
Examples of the inorganic salt include magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium hydrogen sulfate, nickel sulfate and the like.
Preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzoisothiazolin-3-one, benztriazole derivatives, amizing anidine derivatives, quaternary ammonium salts, pyridine, etc. Derivatives such as quinoline and guanidine, diazine, triazole derivative, oxazole, oxazine derivative, nitrobromo alcohol-based 2-bromo-2-nitropropane-1,3-diol, 1,1-dibromo-1-nitro-2-ethanol , 1,1-Dibromo-1-nitro-2-propanol and the like.
As the defoaming agent, a general silicone-based self-emulsifying type, emulsifying type, or surfactant nonionic compound having an HLB value of 5 or less can be used.

(Planographic printing plate manufacturing method and lithographic printing method)
A lithographic printing plate can be produced by image-exposing the lithographic printing plate original plate according to the present disclosure and performing development processing.
The method for producing a lithographic printing plate according to the present disclosure comprises a step of exposing the lithographic printing plate original plate according to the present disclosure to an image (hereinafter, also referred to as an “exposure step”), and a group consisting of printing ink and dampening water. It is preferable to include a step of supplying at least one of the selected ones and removing the image recording layer of the non-image portion on the printing machine (hereinafter, also referred to as “on-machine development step”).
The lithographic printing method according to the present disclosure includes a step of exposing the lithographic printing plate original plate according to the present disclosure to an image (exposure step) and printing by supplying at least one selected from the group consisting of printing ink and dampening water. It is preferable to include a step of removing the image recording layer of the non-image portion on the machine to prepare a lithographic printing plate (on-machine development step) and a step of printing with the obtained lithographic printing plate (printing step).
Hereinafter, preferred embodiments of each step will be described in order with respect to the method for producing a lithographic printing plate according to the present disclosure and the lithographic printing method according to the present disclosure. The lithographic printing plate original plate according to the present disclosure can also be developed with a developing solution.
Hereinafter, the exposure step and the on-machine development step in the lithographic printing plate manufacturing method will be described, but the exposure step in the lithographic printing plate manufacturing method according to the present disclosure and the exposure step in the lithographic printing method according to the present disclosure are the same. It is a step, and the on-machine development step in the method for producing a lithographic printing plate according to the present disclosure and the on-machine development step in the lithographic printing method according to the present disclosure are the same steps.
Further, it is estimated that a part of the outermost layer is removed during on-machine development, and a part of the outermost layer remains on the surface of the image portion or permeates into the inside of the image portion by printing ink.

<Exposure process>
The method for producing a lithographic printing plate according to the present disclosure preferably includes an exposure step of exposing the lithographic printing plate original plate according to the present disclosure to an image to form an exposed portion and an unexposed portion. The planographic printing plate original plate according to the present disclosure is preferably exposed by laser exposure through a transparent original image having a line image, halftone dot image, or the like, or by laser light scanning with digital data or the like.
The wavelength of the light source is preferably 750 nm to 1,400 nm. As a light source having a wavelength of 750 nm to 1,400 nm, a solid-state laser and a semiconductor laser that emit infrared rays are suitable. Regarding the infrared laser, the output is preferably 100 mW or more, the exposure time per pixel is preferably 20 microseconds or less, and the irradiation energy amount is 10 mJ / cm ² to 300 mJ / cm ^2. preferable. Further, it is preferable to use a multi-beam laser device in order to shorten the exposure time. 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 conventional method using a platesetter or the like. In the case of on-machine development, the lithographic printing plate original plate may be mounted on the printing machine and then the image may be exposed on the printing machine.

<In-machine development process>
The method for producing a lithographic printing plate according to the present disclosure involves an on-machine development step of supplying at least one selected from the group consisting of printing ink and dampening water to remove an image recording layer in a non-image area on a printing machine. It is preferable to include it.
The on-machine development method will be described below.

[In-machine development method]
In the on-machine development method, the image-exposed lithographic printing plate original plate supplies oil-based ink and water-based components on the printing machine, and the image recording layer in the non-image area is removed to produce a lithographic printing plate. Is preferable.
That is, either the flat plate printing plate original plate is mounted on the printing machine as it is without any development processing after the image exposure, or the flat plate printing plate original plate is mounted on the printing machine and then the image is exposed on the printing machine, and then When printing is performed by supplying an oil-based ink and a water-based component, in the non-image area, an uncured image recording layer is formed by either or both of the supplied oil-based ink and the water-based component in the initial stage of printing. It dissolves or disperses and is removed, exposing a hydrophilic surface in that area. On the other hand, in the exposed portion, the image recording layer cured by exposure forms an oil-based ink receiving portion having a lipophilic surface. The first supply to the printing plate may be an oil-based ink or a water-based component, but the oil-based ink is first supplied in terms of preventing contamination by the components of the image recording layer from which the water-based components have been removed. Is preferable. In this way, the lithographic printing plate original plate is developed on the printing machine and used as it is for printing a large number of sheets. As the oil-based ink and the water-based component, ordinary printing ink for lithographic printing and dampening water are preferably used.

The wavelength of the light source is preferably 300 nm to 450 nm or 750 nm to 1,400 nm as the laser for image-exposing the lithographic printing plate original plate according to the present disclosure. In the case of a light source having a wavelength of 300 nm to 450 nm, a lithographic printing plate original plate containing a sensitizing dye having an absorption maximum in this wavelength region in the image recording layer is preferably used, and the light source having a wavelength of 750 nm to 1,400 nm is the above-mentioned one. It is preferably used. A semiconductor laser is suitable as a light source having a wavelength of 300 nm to 450 nm.

<Developer development process>
The method for producing a lithographic printing plate according to the present disclosure is a step of exposing the lithographic printing plate original plate according to the present disclosure to an image, and a step of removing the image recording layer of the non-image portion with a developing solution to prepare a lithographic printing plate ( It may also be a method including "developer development step").
Further, the lithographic printing method according to the present disclosure includes a step of exposing the lithographic printing plate original plate according to the present disclosure to an image, and a step of removing the image recording layer of the non-image portion with a developing solution to prepare a lithographic printing plate. The method may include a step of printing with the obtained lithographic printing plate.
As the developing solution, a known developing solution can be used.
The pH of the developing solution is not particularly limited and may be a strong alkaline developing solution, but a developing solution having a pH of 2 to 11 is preferable. As the developing solution having a pH of 2 to 11, for example, a developing solution containing at least one of a surfactant and a water-soluble polymer compound is preferable.
In the development process using a strong alkaline developer, a method of removing the protective layer by a pre-washing step, then performing alkaline development, removing the alkali by washing with water in a post-washing step, performing a gum solution treatment, and drying in a drying step. Can be mentioned.
When the developer containing a surfactant or a water-soluble polymer compound is used, the developer-gum solution treatment can be performed at the same time. Therefore, the post-washing step is not particularly required, and the drying step can be performed after the development and the gum liquid treatment are performed with one liquid. Further, since the protective layer can be removed at the same time as the development and the gum liquid treatment, the pre-washing step is not particularly required. After the development treatment, it is preferable to remove excess developer using a squeeze roller or the like and then dry.

<Printing process>
The lithographic printing method according to the present disclosure includes a printing step of supplying printing ink to a lithographic printing plate to print a recording medium.
The printing ink is not particularly limited, and various known inks can be used as desired. Further, as the printing ink, oil-based ink or ultraviolet curable ink (UV ink) is preferably mentioned.
Further, in the printing process, dampening water may be supplied as needed.
Further, the printing step may be continuously performed in the on-machine development step or the developer development step without stopping the printing machine.
The recording medium is not particularly limited, and a known recording medium can be used as desired.

In the method for producing a lithographic printing plate from the lithographic printing plate original plate according to the present disclosure and the lithographic printing method according to the present disclosure, lithographic printing is performed before, during, and between exposure and development as necessary. The entire surface of the plate original may be heated. By such heating, the image formation reaction in the image recording layer is promoted, and advantages such as improvement of sensitivity and printing durability and stabilization of sensitivity may occur. Heating before development is preferably performed under mild conditions of 150 ° C. or lower. In the above aspect, it is possible to prevent problems such as hardening of the non-image area. For heating after development, it is preferable to use conditions stronger than the above, and it is preferably in the range of 100 ° C. to 500 ° C. Within the above range, a sufficient image enhancement effect can be obtained, and problems such as deterioration of the support and thermal decomposition of the image portion can be suppressed.

Hereinafter, the present disclosure will be described in detail by way of examples, but the present disclosure is not limited thereto. In this embodiment, "%" and "parts" mean "mass%" and "parts by mass", respectively, unless otherwise specified.
In addition, A-1, A-4, A-7, A-9, A-13, A-16, A-21, A-46, A-55, AN-1 and AN-2 used in an Example Is the same as A-1, A-4, A-7, A-9, A-13, A-16, A-21, A-46, A-55, AN-1 and AN-2 described above, respectively. It is a compound.

(Examples 1 to 34 and comparative examples 1 to 5)
<Preparation of support 1>
The following treatments (Ja) to (Jm) were applied to an aluminum plate (aluminum alloy plate) of a material 1S having a thickness of 0.3 mm to manufacture a support 1. A water washing treatment was performed during all the treatment steps, and after the water washing treatment, the liquid was drained with a nip roller.

(Ja) Mechanical roughening treatment (brush grain method)
Using a device as shown in FIG. 7, while supplying a suspension of pumice (specific gravity 1.1 g / cm ³ ) to the surface of an aluminum plate as a polishing slurry liquid, a mechanical rough surface is mechanically roughened by a rotating bundled planting brush. The conversion process was performed. In FIG. 7, 1 is an aluminum plate, 2 and 4 are roller-shaped brushes (in this embodiment, a bundled brush), 3 is a polishing slurry liquid, and 5, 6, 7 and 8 are support rollers.
In the mechanical roughening treatment, the median diameter (μm) of the abrasive was 30 μm, the number of brushes was 4, and the rotation speed (rpm) of the brushes was 250 rpm. The material of the bundled brush was 6.10 nylon, and the diameter of the brush bristles was 0.3 mm and the bristles length was 50 mm. The brush was made by making a hole in a stainless steel cylinder having a diameter of 300 mm and flocking the brush so as to be dense. The distance between the two support rollers (φ200 mm) at the bottom of the bundled brush was 300 mm. The bundled brush was pressed until the load of the drive motor for rotating the brush became 10 kW plus the load before pressing the bundled brush against the aluminum plate. The direction of rotation of the brush was the same as the direction of movement of the aluminum plate.

(Jb) Alkaline Etching Treatment An aqueous solution of caustic soda having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass was sprayed onto an aluminum plate at a temperature of 70 ° C. to perform an etching treatment. The amount of aluminum dissolved on the surface to be subjected to the electrochemical roughening treatment later was 10 g / m ² .

(Jc) Desmat treatment using an acidic aqueous solution As an acidic aqueous solution, the waste liquid of nitric acid used for the electrochemical roughening treatment in the next step at a liquid temperature of 35 ° C. is sprayed onto an aluminum plate for 3 seconds to desmatte. Processing was performed.

(Jd) Electrochemical roughening treatment using an aqueous nitric acid solution An electrochemical roughening treatment was continuously performed using an AC voltage of 60 Hz. As the electrolytic solution, an electrolytic solution having a liquid temperature of 35 ° C. was used, in which aluminum nitrate was added to an aqueous solution of 10.4 g / L of nitric acid to adjust the aluminum ion concentration to 4.5 g / L. The AC power supply waveform is the waveform shown in FIG. 5, in which the time tp from zero to the peak of the current value is 0.8 msec, the duty ratio is 1: 1, and the trapezoidal square wave AC is used, with the carbon electrode as the counter electrode. An electrochemical roughening treatment was performed. Ferrite was used as the auxiliary anode. The electrolytic cell shown in FIG. 6 was used. The current density was 30 A / dm ² at the peak value of the current, and 5% of the current flowing from the power supply was diverted to the auxiliary anode. Amount of electricity (C / dm ²⁾ the aluminum plate was 185C / dm ² as the total quantity of electricity when the anode.

(Je) Alkaline Etching Treatment An aqueous caustic soda solution having a caustic soda concentration of 27% by mass and an aluminum ion concentration of 2.5% by mass was sprayed onto an aluminum plate at a temperature of 50 ° C. to perform an etching treatment. The amount of aluminum dissolved was 3.5 g / m ² .

(Jf) Desmat treatment using an acidic aqueous solution As an acidic aqueous solution, an aqueous solution having a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L at a liquid temperature of 30 ° C. is sprayed onto an aluminum plate for 3 seconds to perform a desmat treatment. went.

(Jg) Electrochemical roughening treatment using an aqueous hydrochloric acid solution An electrochemical roughening treatment was continuously performed using an AC voltage of 60 Hz. As the electrolytic solution, an electrolytic solution having a liquid temperature of 35 ° C. was used, in which aluminum chloride was added to an aqueous solution of 6.2 g / L of hydrochloric acid to adjust the aluminum ion concentration to 4.5 g / L. The AC power supply waveform is the waveform shown in FIG. 5, in which the time tp from zero to the peak of the current value is 0.8 msec, the duty ratio is 1: 1, and the trapezoidal square wave AC is used, with the carbon electrode as the counter electrode. An electrochemical roughening treatment was performed. Ferrite was used as the auxiliary anode. The electrolytic cell shown in FIG. 6 was used. The current density was 25A / dm ² at the peak of electric current amount of hydrochloric acid electrolysis (C / dm ²⁾ the aluminum plate was 63C / dm ² as the total quantity of electricity when the anode.

(Jh) Alkaline Etching Treatment An aqueous solution of caustic soda having a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass was sprayed onto an aluminum plate at a temperature of 60 ° C. to perform an etching treatment. The amount of aluminum dissolved was 0.2 g / m ² .

(Ji) Desmat treatment using an acidic aqueous solution As an acidic aqueous solution, an aqueous solution of waste liquid (sulfuric acid concentration 170 g / L and aluminum ion concentration 5 g / L) generated in the anodic oxidation treatment step at a liquid temperature of 35 ° C. is sprayed on an aluminum plate. Was sprayed for 4 seconds to perform desmat treatment.

(Jj) First-stage anodizing treatment The first-stage anodizing treatment was performed using an anodizing apparatus by direct current electrolysis having the structure shown in FIG. Anodizing treatment was carried out using a 170 g / L sulfuric acid aqueous solution as an electrolytic solution under the conditions of a liquid temperature of 50 ° C. and a current density of 30 A / dm ² to form an anodized film having a film amount of 0.3 g / m ^2.
In the anodizing treatment apparatus 610, the aluminum plate 616 is conveyed as shown by an arrow in FIG. The aluminum plate 616 is charged to (+) by the feeding electrode 620 in the feeding tank 612 in which the electrolytic solution 618 is stored. Then, the aluminum plate 616 is conveyed upward by the roller 622 in the power supply tank 612, turned downward by the nip roller 624, and then conveyed toward the electrolytic treatment tank 614 in which the electrolytic solution 626 is stored, and is conveyed by the roller 628. Turns horizontally. Then, the aluminum plate 616 is charged to (-) by the electrolytic electrode 630 to form an anodic oxide film on the surface thereof, and the aluminum plate 616 leaving the electrolytic treatment tank 614 is conveyed to a subsequent process. In the anodizing treatment apparatus 610, the direction changing means is composed of the roller 622, the nip roller 624 and the roller 628, and the aluminum plate 616 is formed in the inter-tank portion between the power supply tank 612 and the electrolytic treatment tank 614, and the roller 622, the nip roller 624 and the roller By 628, it is conveyed in a chevron shape and an inverted U shape. The feeding electrode 620 and the electrolytic electrode 630 are connected to the DC power supply 634.

(Jk) Pore Wide Treatment The anodized aluminum plate was immersed in a caustic soda aqueous solution having a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass at 40 ° C. for 3 seconds to perform a pore wide treatment.

(Jl) Second-stage anodizing treatment The second-stage anodizing treatment was performed using an anodizing apparatus by direct current electrolysis having the structure shown in FIG. Anodizing treatment was carried out using a 170 g / L sulfuric acid aqueous solution as an electrolytic solution under the conditions of a liquid temperature of 50 ° C. and a current density of 13 A / dm ² to form an anodized film having a film amount of 2.1 g / m ^2.

(Jm) Hydrophilization Treatment In order to ensure the hydrophilicity of the non-imaged portion, an aluminum plate was immersed in a 2.5 mass% No. 3 sodium silicate aqueous solution at 50 ° C. for 7 seconds to perform a silicate treatment. The amount of Si adhered was 8.5 mg / m ² . The average diameter of the micropores was 30 nm.
The value of the lightness L ^* ^{in the L *} a ^* b ^* color system on the surface of the anodic oxide film of the support 1 was 72.3.

<Formation of undercoat layer>
Next, the undercoat layer coating liquid (1) having the following composition was applied onto the support 1 so that the dry coating amount was 20 mg / m ² to form an undercoat layer.
In Example 16 or 17, phosphoric acid or gluconic acid was added to the undercoat layer coating liquid (1) so that the dry coating amount was the amount shown in Table 1, and the dry coating amount was 70 mg / m ² . It was applied so as to form an undercoat layer.
Moreover, in Examples 25 to 30, the undercoat layer was not formed.

[Coating liquid for undercoat layer (1)]
-Compound for undercoat layer with the following structure (1): 0.18 parts-Hydroxyethyliminodiacetic acid: 0.10 parts-Methanol: 55.24 parts-Water: 6.15 parts

<Formation of image recording layer>
The image recording layer was formed by any of the following image recording layers (1) to (4) shown in Table 1.

<< Formation of image recording layer (1) >>
An image recording layer coating liquid (1) having the following composition is bar-coated on the undercoat layer or the support 1, and dried in an oven at 100 ° C. for 60 seconds to obtain an image recording layer ^{having a dry coating amount of 1.0 g / m 2.} 1) was formed.
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)-
-Color-developing compound shown in Table 1: Amount of dry coating amount shown in Table 1-Support-adsorbing compound shown in Table 1: Amount of dry coating amount shown in Table 1-Binder polymer (1) [Structure below]: 0.240 parts, polymerization initiator (1) [Structure below]: 0.245 parts, borate compound (sodium tetraphenylborate): 0.010 parts, polymerizable compound (Tris (acryloyloxyethyl) ) Isocyanurate, NK ester A-9300, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 0.192 parts, low molecular weight hydrophilic compound (Tris (2-hydroxyethyl) isocyanurate): 0.062 parts, low molecular weight hydrophilic Sex compounds (1) [the following structure]: 0.050 parts, fluorine-based surfactant (1) [the following structure]: 0.008 parts, 2-butanone: 1.091 parts, 1-methoxy-2-propanol: 8.609 copies

-Microgel liquid-
・ Microgel (1): 2.640 parts ・ Distilled water: 2.425 parts

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 polyvalent 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-ene-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 number average particle size was measured by the light scattering method using a laser diffraction / scattering type particle size distribution measuring device (LA-920, manufactured by HORIBA, Ltd.), it was 0.28 μm.

[Oil phase component]
(Component 1) Ethyl acetate: 12.0 g
(Component 2) An addition (1 mol, number of repetitions of oxyethylene unit: 90) added to trimethylolpropane (6 mol) and xylene diisocyanate (18 mol). 50 mass% ethyl acetate solution, manufactured by Mitsui Kagaku Co., Ltd .: 3.76 g
(Component 3) Multivalent isocyanate compound (1) (as a 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

[Aqueous 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 undercoat layer formed as described above, dried in an oven at 100 ° C. for 60 seconds, and an image ^{having a dry coating amount of 1.0 g / m 2.} The recording layer (2) was formed.
The image recording layer coating liquid (2) was obtained by mixing and stirring the following photosensitive liquid (2) and microgel liquid (2) immediately before coating.

[Photosensitive liquid (2)]
-Color-developing compounds shown in Table 1: Amount of dry coating shown in Table 1-Support-adsorbing compounds shown in Table 1: Amount of dry coating shown in Table 1-Binder polymer (2) [The following structure, Mw: 55,000, n: 2 (number of ethylene oxide (EO) units)]: 0.240 parts, borate compound (sodium tetraphenylborate): 0.010 parts, polymerization initiator (1) [Structure]: 0.162 parts, polymerizable compound (Tris (acryloyloxyethyl) isocyanurate, NK ester A-9300, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 0.192 parts, low molecular weight hydrophilic compound ( 1) [Structure]: 0.050 parts-Fat sensitive agent (phosphonium compound (1) [structure below]): 0.055 parts-Fat sensitive agent (benzyl-dimethyl-octylammonium / PF ₆ salt): 0.018 parts-Ammonium group-containing polymer (1) [Structure below, Mw: 50,000, Reduction specific viscosity: 45 ml / g]: 0.040 parts-Fluorine-based surfactant (1) [Structure below]: 0 .008 parts ・ 2-butanone: 1.091 parts ・ 1-methoxy-2-propanol: 8.609 parts

[Microgel liquid (2)]
・ Microgel (2): 2.640 parts ・ Distilled water: 2.425 parts

The method for synthesizing the above microgel (2) is as shown below.
-Synthesis of microgel (2)-
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (manufactured by Mitsui Chemicals Polyurethane Co., Ltd., Takenate D-110N) 10 g, pentaerythritol triacrylate (manufactured by Nippon Kayaku Co., Ltd., SR444) 3.15 g, And 0.1 g of alkylbenzene sulfonate (manufactured by Takemoto Oil & Fat Co., Ltd., Pionin A-41C) was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of polyvinyl alcohol (PVA-205, manufactured by Kuraray Co., Ltd.) was prepared. The oil phase component and the aqueous phase component were mixed and emulsified at 12,000 rpm for 10 minutes using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 50 ° C. for 3 hours. The solid content concentration of the microgel solution thus obtained was diluted with distilled water so as to be 15% by mass, and this was used as the above-mentioned microgel (2). The volume average particle size of the microgel was measured by the light scattering method and found to be 0.2 μm.

<< Formation of image recording layer (3) >>
An image recording layer coating liquid (3) having the following composition is bar-coated on the undercoat layer or support 1 formed as described above to a thickness of 30 μm, dried in an oven at 120 ° C. for 1 minute, and image-recorded. The layer (3) was formed.

[Image recording layer coating liquid (3)]
-Color-developing compounds shown in Table 1: Amount of dry coating shown in Table 1-Support-adsorbing compounds shown in Table 1: Amount of dry coating shown in Table 1.-2, 2, 4 -2 mol equivalent hydroxyethyl methacrylate adduct of trimethylhexamethylene diisocyanate (82 mass% methyl ethyl ketone solution, manufactured by AZ Electronics): 0.250 parts, epoxy acrylate oligomer (manufactured by Archema): 0.250 parts, bis (4) -T-Butylphenyl) Iodonium tetraphenylborate: 0.045 parts-Polyvinyl butyral (S-LEC BX35-Z manufactured by Sekisui Chemical Industry Co., Ltd.): 0.150 parts-Tego Glide 410 (polyether-modified polysiloxane copolymer, Evonik Tego Chemie): 0.0015 parts ・ Phosphonate ester compound having a methacryloxy group (Sipomer PAM 100, manufactured by Rhodia): 0.130 parts ・ Copolymer of vinylphosphonic acid and acrylic acid (20% by mass) Aqueous dispersion, Acrytect CP 30, manufactured by Rhodia): 0.024 part ・ Methyl ethyl ketone: 1-methoxy-2-propanol = 35:65 (volume ratio) mixed solvent: Amount of solid content of 35% by volume

<< Formation of image recording layer (4) >>
An image recording layer water-based coating liquid containing thermoplastic polymer particles, an infrared absorber and polyacrylic acid was prepared, the pH was adjusted to 3.6, and then the coating was applied on the undercoat layer or the support 1 and 1 at 50 ° C. It was dried for a minute to form an image recording layer (4). The amount of each component applied after drying is shown below.

-Color-developing compounds shown in Table 1: Amount of dry coating amount shown in Table 1-Support-adsorptive compounds shown in Table 1: Amount of dry coating amount shown in Table 1-Thermoplastic polymer particles: 0.7g / m ²
-Polyacrylic acid: 0.09 g / m ²

The thermoplastic polymer particles, infrared absorber IR-01, and polyacrylic acid used in the image recording layer coating liquid are as shown below.

Thermoplastic polymer particles: styrene / acrylonitrile copolymer (molar ratio 50/50), Tg: 99 ° C., volume average particle size: 60 nm
Polyacrylic acid: Mw: 250,000

<Formation of protective layer>
A protective layer was formed by forming the following protective layer (1) or (2) shown in Table 1.

<< Formation of protective layer (1) >>
A protective layer coating liquid (1) having the following composition was bar-coated on the image recording layer and dried in an oven at 120 ° C. for 60 seconds to form a protective layer (1) having ^{a dry coating amount of 0.15 g / m 2.} ..

-Protective layer coating liquid (1)-
-Color-developing compound shown in Table 1: Amount of dry coating amount shown in Table 1-Support-adsorptive compound shown in Table 1: Amount of dry coating amount shown in Table 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, degree of polymerization 300) 6% by mass aqueous solution: 0.55 parts -Polyvinyl alcohol (PVA-405, manufactured by Kuraray Co., Ltd., saponification degree 81.5 mol%, degree of polymerization 500) 6% by mass aqueous solution: 0.03 parts-Surfactant (polyoxyethylene lauryl ether, Emarex 710, Nippon Emulsion Co., Ltd.) 1% by mass aqueous solution: 0.86 parts, ion-exchanged water: 6.0 parts

The preparation method of the inorganic layered compound dispersion liquid (1) used for the protective layer coating liquid (1) is shown below.

-Preparation of inorganic layered compound dispersion (1)-
6.4 g of synthetic mica (Somasif ME-100, manufactured by Corp 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 protective layer (2) >>
A protective layer coating liquid (2) having the following composition is further bar-coated on the image recording layer, then dried in an oven at 120 ° C. for 60 seconds, and the protective layer (2) ^{having a dry coating amount of 0.15 g / m 2 is dried.} Was formed.

-Coating liquid for protective layer (2)-
-Inorganic layered compound dispersion (1) (obtained above): 1.5 parts-Hydrophilic polymer (1) (solid content) [Structure below, Mw: 30,000]: 0.55 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: 0.10 part ・ Polyvinyl alcohol (PVA-405 manufactured by Kuraray Co., Ltd., saponification degree 81) .5 mol%, degree of polymerization 500) 6 mass% aqueous solution: 0.03 part ・ Surfactant (Emarex 710, trade name: Nippon Emulsion Co., Ltd.) 1 mass% aqueous solution: 0.86 part ・ ion exchange water : 6.0 copies

<Formation of edge hydrophilized layer>
In Examples 22 and 25, an edge hydrophilized layer was further formed.
As a coating device, 2NL04 manufactured by Hyojin Equipment Co., Ltd. was used.
As the coating liquid for forming the edge hydrophilic layer, components other than the pure water described below were added to pure water and stirred to prepare a coating liquid containing a hydrophilic component.
-Compound represented by the following formula P-2 (Mw: 100,000): 5.0 parts by mass-Microgel (2): 1.0 part by mass-Pure water: 194 parts by mass

The transport speed was adjusted with a clearance of 0.3 mm and a liquid feed rate of 5 cc / min, and the coating liquid was applied so that the solid content coating amount was 1.7 g / m ² .
The coating was applied to a region (two places) having a width of 5 mm centered at a position of 3 cm from each of the two opposite end portions of the support.
After coating, it was dried at 120 ° C. for 1 minute to form an edge hydrophilized layer as the outermost layer on the image recording layer side.

<Cutting of lithographic printing plate original plate>
The planographic printing plate original plate obtained as described above 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 slitter device as shown in FIG. 2, and the results are shown in Table 1. A sagging shape was formed at the described end.
The cutting position was set at the center of the formation region of the edge hydrophilic layer (position 3 cm from each of the two opposite sides of the support), and two points of the support were cut.
Table 1 shows the sagging amount X and the sagging width Y in the sagging shape.

<Evaluation of color development and color development over time>
The lithographic printing plate original is exposed by Creo's Trendsetter 3244VX equipped with a water-cooled 40W infrared semiconductor laser under the conditions of output 11.7W, outer drum rotation speed 250rpm, and resolution 2,400 dpi (dots per inch, 1 inch = 25.4 mm). bottom. The exposure was performed in an environment of 25 ° C. and 50% RH.
Immediately after exposure (color development) and after storage in a dark place (25 ° C.) for 2 hours after exposure (color development over time), the color development of the lithographic printing plate original plate was measured. The measurement was performed by the SCE (specular reflection light removal) method using a spectrocolorimeter CM2600d manufactured by Konica Minolta Co., Ltd. and an operation software CM-S100W. Chromogenic ^uses the L ^* a * ^{b *} color system of ^{L *} value (lightness) was evaluated by the difference ΔL between the ^{L *} values of the ^{L *} value and the unexposed portions of the exposed portion. The larger the value of ΔL, the better the color development.

<Evaluation of edge stain suppression>
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 drum rotation speed of 1,000 rpm, a laser output of 70%, and a resolution of 2,400 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 1,000th sheet with a water scale 1.1 times the water scale for removing ground stains. Sampling was performed, and the degree of linear stain caused by the edge of the printing original plate was evaluated according to the following criteria.
5: Not dirty at all 4: Intermediate level between 5 and 3 3: Slightly dirty but acceptable level 2: Intermediate level between 3 and 1 (acceptable level)
1: Clearly dirty and unacceptable level

<Evaluation of on-machine developability>
The lithographic printing plate original plate was exposed by a Luxel PLATESETTER T-6000III manufactured by FUJIFILM Corporation equipped with an infrared semiconductor laser under the conditions of an outer drum rotation speed of 1,000 rpm, a laser output of 70%, and a resolution of 2,400 dpi. The exposed image included a solid image and a 50% halftone dot chart of a 20 μm dot FM screen.
The exposed planographic printing plate original plate was attached to the plate cylinder of the printing machine LITHRONE26 manufactured by Komori Corporation without developing. Efficiency-2 (manufactured by Fujifilm Co., Ltd.) / tap water = 2/98 (volume ratio) of dampening water and Values-G (N) ink ink (manufactured by DIC Graphics Co., Ltd.) of LITHRONE26 We supply dampening water and ink using the standard automatic printing start method, and print 100 sheets on Tokubishi Art Paper (ream weight: 76.5 kg, manufactured by Mitsubishi Paper Mills Limited) at a printing speed of 10,000 sheets per hour. went.
The number of printing papers required to complete the on-machine development of the unexposed portion of the image recording layer on the printing machine and to prevent the ink from being transferred to the non-image portion was measured and evaluated as the on-machine developability. The smaller the number, the better the on-machine developability.

<Chemical resistance (cleaner printing resistance) evaluation>
After evaluating the on-machine developability, printing was continued. As the number of printed sheets increased, the image recording layer was gradually worn, so that the ink density on the printed matter decreased. In addition, every time 10,000 sheets were printed during printing, the plate surface was wiped with a cleaner (manufactured by FUJIFILM Corporation, HN-C). The number of printed sheets was measured until the value measured by the Gretag densitometer of the halftone dot area ratio of the FM screen 50% halftone dot in the printed matter was 5% lower than the measured value of the 100th printed sheet. The evaluation was made based on the relative printing resistance of 100 when the number of printed sheets was 100,000. The larger the value, the better the printing durability.
Relative printing resistance = (number of prints of target lithographic printing plate original plate) / 100,000 x 100

The evaluation results are summarized in Table 1.

Note that B-1 and B-2 shown in Table 1 are the following compounds.

From the results shown in Table 1, the lithographic printing plate original plates of Examples 1 to 34, which are the lithographic printing plate original plates according to the present disclosure, are superior in edge stain suppression property as compared with the lithographic printing plate original plates of the comparative examples.
Further, from the results shown in Table 1, the lithographic printing plate original plates of Examples 1 to 34, which are the lithographic printing plate original plates according to the present disclosure, have improved color development property, color development property over time, on-machine developability, and chemical resistance. Is also excellent.

X: Amount of sagging, Y: Sagging width, 1: Aluminum plate, 2, 4: Roller brush, 3: Polishing slurry liquid, 5, 6, 7, 8: Support roller, 18: Aluminum plate, ta: Anode reaction time , Tc: Cathode reaction time, tp: Time from 0 to peak of current, Ia: Peak current on the anode cycle side, Ic: Peak current on the cathode cycle side, AA: Anode reaction of aluminum plate Current, CA: Current of cathode reaction of aluminum plate, 10: Plate printing plate original plate, 12a, 12b: Aluminum support, 14: Undercoat layer, 16: Image recording layer, 20a, 20b: Anode oxide film, 22a, 22b: Micropore, 24: Large-diameter hole, 26: Small-diameter hole, D: Depth of large-diameter hole, 50: Main anode, 51: AC power supply, 52: Radial drum roller, 53a, 53b: Main pole, 54: Electrolyte supply port, 55: Electrolyte, 56: Auxiliary anode, 60: Auxiliary anode tank, W: Aluminum plate, A1: Liquid supply direction, A2: Electrolyte discharge direction, 210: Cutting blade, 210a: Upper cutting Blade, 210b: Upper cutting blade, 211: Rotating shaft, 220: Cutting blade, 220a: Lower cutting blade, 220b: Lower cutting blade, 221: Rotating shaft, 230: Support, 610: Anode oxidation treatment device, 612 : Feeding tank, 614: Electrolytic treatment tank, 616: Aluminum plate, 618, 26: Electrolyte, 620: Feeding electrode, 622,628: Roller, 624: Nip roller, 630: Electrolytic electrode, 632: Tank wall, 634: DC Power supply

The disclosure of Japanese Patent Application No. 2020-034241 filed on February 28, 2020 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Is incorporated herein by reference.

Claims

A layer containing a chromogenic compound having a group that is cleaved by thermal or infrared exposure is provided on the support.
A lithographic printing plate original plate having a sagging shape having a sagging amount X of 25 μm to 150 μm and a sagging width Y of 70 μm to 300 μm at at least two opposite ends of the support.
The planographic printing plate original plate according to claim 1, wherein the layer containing the color-developing compound is an image recording layer.
It has an image recording layer on the support and
The lithographic printing plate original plate according to claim 1, which has a layer containing the color-developing compound on the image recording layer.
The planographic printing plate original plate according to any one of claims 1 to 3, wherein the color-developing compound having a group that cleaves by heat or infrared exposure is a compound represented by the following formula (1).

In formula (1), M 1 is a group that is cleaved by thermal or infrared exposure, R 2 and R 3 independently represent a hydrogen atom or an alkyl group, and R 2 and R 3 are connected to each other to form a ring. They may be formed, where Ar 1 and Ar 2 each independently represent a group forming a benzene ring or a naphthalene ring, and Y 1 and Y 2 independently represent an oxygen atom, a sulfur atom, -NR 0- or a dialkyl. R 4 and R 5 each independently represent an aliphatic hydrocarbon group, R 6 to R 9 each independently represent a hydrogen atom or an alkyl group, and R 0 represents a hydrogen atom, an alkyl group or an alkyl group. Represents an aryl group and Za represents a counterion that neutralizes the charge.
The fourth aspect of the present invention, wherein at least one group selected from the group consisting of R 4, R 5 , M 1 , Ar 1 and Ar 2 in the compound represented by the formula (1) has a hydrophilic group. Planographic printing plate original plate.
The planographic printing plate original plate according to claim 5, wherein the hydrophilic group is a group represented by any of the following formulas (2) to (5).

In formulas (2) to (5), R 10 represents an alkylene group having 2 to 6 carbon atoms, W 1 represents a single bond or an oxygen atom, n1 represents an integer of 1 to 45, and R 11 represents carbon. Represents an alkyl group of number 1 to 12 or an acyl group of 2 to 12 carbon atoms, and R 12 and R 13 independently represent a single bond or an alkylene group or alkylene oxy group having 1 to 12 carbon atoms, respectively. Represents a hydrogen atom, a Na atom, a K atom or an onium group, and if the charge can be neutralized in the whole compound represented by the formula (1), it does not have to have M, and m1 is 1. It represents 2, 3 or 4, X 1 represents -O-, -S- or -CH 2- , and the wavy line portion represents the bonding position with other structures.
In any one of claims 4 to 6, where M 1 in the formula (1) is -NR a R b , -NR c (SO 2 R d ) or -NR e (CO 2 R f). The original planographic printing plate described.
However, R a and R b each independently represent an aryl group, R c , Re and R f independently represent an alkyl group or an aryl group, and R d is an alkyl group, an aryl group, or an aryl group. -NR d1 represents R d2 , and R d1 and R d2 independently represent a hydrogen atom, an alkyl group or an aryl group.
Formula M 1 is in (1), lithographic printing plate precursor as claimed in any one of Claims 4 to 6 is -O-R 1.
However, R 1 is, R 1 -O bond by heat or infrared exposure represents a group which cleaves.
The flat plate printing plate original plate according to claim 8, wherein R 1 is a group represented by the following formula (6).

In formula (6), R 15 and R 16 independently represent a hydrogen atom, an alkyl group or an aryl group, E represents an onium group, and the wavy line portion represents a bond position with an oxygen atom.
The planographic printing plate original plate according to claim 9, wherein E in the formula (6) is a pyridinium group represented by the following formula (7).

Wherein (7), R 17 represents a halogen atom, an alkyl group, an aryl group, hydroxy group or alkoxy group, if R 17 there are a plurality, the plurality of R 17 may be the same or different, or a plurality of R 17 may be linked to form a ring, n2 represents an integer of 0 to 4, and R 18 is an alkyl group, an aryl group, or a group represented by any of the following formulas (2) to (5). Represents, and Zb represents a counterion for neutralizing the charge.

In formulas (2) to (5), R 10 represents an alkylene group having 2 to 6 carbon atoms, W 1 represents a single bond or an oxygen atom, n1 represents an integer of 1 to 45, and R 11 represents carbon. Represents an alkyl group of number 1 to 12 or an acyl group of 2 to 12 carbon atoms, and R 12 and R 13 independently represent a single bond or an alkylene group or alkylene oxy group having 1 to 12 carbon atoms, respectively. Represents a hydrogen atom, a Na atom, a K atom or an onium group, and if the charge can be neutralized in the whole compound represented by the formula (1), it does not have to have M, and m1 is 1. It represents 2, 3 or 4, X 1 represents -O-, -S- or -CH 2- , and the wavy line portion represents the bonding position with other structures.
The lithographic printing plate original plate according to claim 2 or 3, wherein the image recording layer has a polymerization initiator and a polymerizable compound.
The lithographic printing plate original plate according to claim 2, claim 3 or claim 11, wherein the image recording layer has polymer particles.
The planographic printing plate original plate according to any one of claims 1 to 12, which contains a support-adsorbing compound having a molecular weight of 1,000 or less in any layer.
The lithographic printing plate original plate according to any one of claims 1 to 13, which has a hydrophilic layer in a region within 1 cm from the end of the surface of the lithographic printing plate original plate on the image recording layer side.
A step of exposing the lithographic printing plate original plate according to any one of claims 1 to 14 to an image.
A method for producing a lithographic printing plate, comprising a step of supplying at least one selected from the group consisting of printing ink and dampening water on a printing machine to remove an image recording layer in a non-image area.
A step of exposing the lithographic printing plate original plate according to any one of claims 1 to 14 to an image.
A process of supplying at least one selected from the group consisting of printing ink and dampening water to remove the image recording layer of the non-image area on the printing machine to prepare a lithographic printing plate.
A lithographic printing method including a step of printing with the obtained lithographic printing plate.