WO2020262695A1 - On-machine development lithographic printing plate original, lithographic printing plate manufacturing method, and lithographic printing method - Google Patents

Abstract

Provided is an on-machine development lithographic printing plate original that has an aluminum support and an image recording layer on the aluminum support. The image recording layer contains: an infrared absorber; a polymerization initiator; a polymerizable compound the molecular weight of which is less than 2500; and a polymer the molecular weight of which is equal to or greater than 2500 and that has a polymerizable group. The polymerizable compound includes a polymerizable compound having seven or more functionalities. Also provided is a lithographic printing plate manufacturing method or a lithographic printing method employing the on-machine development lithographic printing plate original.

Description

On-machine development type lithographic printing plate Original plate, lithographic printing plate manufacturing method, and lithographic printing method

This disclosure relates to an on-machine development type lithographic printing plate original plate, a method for producing a lithographic printing plate, and a lithographic printing method.

In general, a lithographic printing plate comprises a lipophilic image portion that receives ink in the printing process and a hydrophilic non-image portion 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.
In order to produce this lithographic printing plate, a lithographic printing plate original plate (PS plate) in which a lipophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support has been widely used. Normally, after exposing the original plate of a flat plate printing plate through an original image such as a squirrel film, the part that becomes the image part of the image recording layer remains, and the other unnecessary image recording layer is an alkaline developer or organic. A flat plate printing plate is obtained by performing plate making by a method of dissolving and removing with a solvent to expose the surface of a hydrophilic support to form a non-image portion.

In addition, due to growing interest in the global environment, environmental issues related to waste liquids associated with wet treatments such as development treatments have been highlighted.
In response to the above environmental issues, simplification and non-processing of development or plate making are aimed at. As one of the simple manufacturing methods, a method called "machine development" is performed. That is, after the lithographic printing plate original plate is exposed, the conventional development is not performed, and the printing machine is mounted as it is, and unnecessary portions of the image recording layer are removed at the initial stage of the normal printing process.

Examples of the printing method using the conventional planographic printing plate original plate include those described in Patent Document 1.
Patent Document 1 is a printing method of a lithographic printing plate original plate having an image recording layer developed by supplying at least one of printing ink and dampening water on an aluminum support, and is described below at the start of printing. Performing the steps (i) to (v) in the order of (i) (ii) (iii) (iv) (v) or (i) (iii) (ii) (iv) (v). The characteristic printing method is described.
(I) After exposing the planographic printing plate original plate as an image, it is attached to the plate cylinder of the printing machine.
(Ii) Damping water to at least one of a watering roller which is a dampening water supply means of a printing machine, a roller for supplying water to the watering roller, a roller for stabilizing the amount of water, and a metering roller. And at least one of the aqueous solutions containing the organic solvent is spray-supplied.
(Iii) Rotate the water supply roller.
(Iv) The watering roller is brought into contact with the lithographic printing plate original plate, and dampening water is supplied from the watering roller to the lithographic printing plate original plate.
(V) The inking roller is brought into contact with the stencil printing plate original plate, the printing ink is supplied from the inking roller to the stencil printing plate original plate, and the inking roller is brought into contact with the slab printing plate original plate at the same time or after being brought into contact with the original plate. Supply printing paper.

Further, as a conventional planographic printing plate original plate, for example, those described in Patent Document 2 can be mentioned.
Patent Document 2 describes a substrate having a hydrophilic surface, and one or more free radical polymerizable compounds, one or more infrared absorbers, which are arranged on the hydrophilic surface of the substrate. An infrared-sensitive image-forming layer comprising compound A represented by the following structure (I) and one or more compounds represented by the following structure (II) or structure (III) collectively as compound B. Described are initiator compositions that impart free radicals upon exposure to infrared light, and negative infrared sensitive slab printing plates originals that include an infrared sensitive image-forming layer containing a main polymer binder.

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are independently substituted or unsubstituted alkyl groups having 2 to 9 carbon atoms, respectively, or substituted or unsubstituted. It is an alkoxy group, and at least one of R ₃ and R ₄ is different from R ₁ or R _2, and is the total number of carbon atoms in R ₁ and R ₂ and the total number of carbon atoms in R ₃ and R _4. The difference between and is 0-4, and the difference between the total number of carbon atoms in R ₁ and R ₂ and the total number of carbon atoms in R ₅ and R ₆ is 0-4, X ₁ , X ₂ and X ₃ are the same or different anions)

Patent Document 1: Japanese Patent Application Laid-Open No. 2013-78851 Patent Document 2: Japanese Patent Application Laid-Open No. 2019-504780

An object to be solved by the embodiment of the present invention is to provide an on-machine development type lithographic printing plate original plate having excellent on-machine developability and the obtained lithographic printing plate onset property.
An object to be solved by another embodiment of the present invention is to provide a method for producing a lithographic printing plate or a lithographic printing method using the above-mentioned machine-developed lithographic printing plate original plate.

The means for solving the above problems include the following aspects.
<1> An aluminum support and an image recording layer on the aluminum support, and the image recording layer is an infrared absorber, a polymerization initiator, a polymerizable compound having a molecular weight of less than 2,500, and a molecular weight of 2. , 500 or more, and contains a polymer having a polymerizable group, and the above-mentioned polymerizable compound is a machine-developed flat plate printing plate original plate containing a polymerizable compound having 7 or more functions.
<2> The on-board development type lithographic printing plate original plate according to <1>, wherein the contact angle with water due to air droplets on the outermost layer surface on the image recording layer side in the lithographic printing plate original plate is 30 ° to 80 °. ..
<3> In the image recording layer, when the content of the polymer having a polymerizable group is Mp and the content of the polymerizable compound having 7 or more functionalities is Mm, the value of Mm / Mp is 0.01. The machine-developed lithographic printing plate original plate according to <1> or <2> described above.
<4> The machine-developed lithographic printing plate original plate according to any one of <1> to <3>, wherein the polymer having a polymerizable group contains polymer particles having a polymerizable group.
<5> The machine-developed lithographic printing plate original plate according to <4>, wherein the polymer particles have a hydrophilic group.
<6> The machine-developed lithographic printing plate original plate according to <5>, wherein the polymer particles have a polyalkylene oxide structure as the hydrophilic group.
<7> The machine-developed lithographic printing plate original plate according to <6>, wherein the polymer particles have a polypropylene oxide structure as the polyoxyalkylene oxide structure.
<8> The machine-developed lithographic printing plate original plate according to <6> or <7>, wherein the polymer particles have at least a polyethylene oxide structure and a polypropylene oxide structure as the polyoxyalkylene oxide structure.
<9> The above-mentioned one of <4> to <8>, wherein the polymer particles contain a resin having a structure obtained by at least reacting an isocyanate compound represented by the following formula (Iso) with water. On-machine development type lithographic printing plate original plate.

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

<10> The polymer particles have a structure obtained by at least reacting an isocyanate compound represented by the above formula (Iso) with water, and have a polyethylene oxide structure and a polypropylene oxide structure as polyoxyalkylene structures. The machine-developed lithographic printing plate original plate according to <9>, which contains a resin.
<11> The machine-developed lithographic printing plate original plate according to any one of <1> to <10>, wherein the polymer having a polymerizable group is an addition polymerization type resin.
<12> The machine-developed lithographic printing plate original plate according to any one of <1> to <11>, wherein the polymer having a polymerizable group contains a styrene-acrylonitrile copolymer.
<13> The machine-developed lithographic printing plate original plate according to any one of <1> to <12>, wherein the image recording layer is the outermost layer.
<14> The on-board developing type according to any one of <1> to <13>, wherein the contact angle with water by the aerial water droplet method on the surface of the aluminum support on the image recording layer side is 110 ° or less. Planographic printing plate original plate.
<15> The machine-developed lithographic printing plate original plate according to <14>, wherein the contact angle with water by the aerial water droplet method on the surface of the aluminum support on the image recording layer side is 80 ° or less.
<16> The machine-developed lithographic printing plate original plate according to <15>, wherein the contact angle with water by the aerial water droplet method on the surface of the aluminum support on the image recording layer side is 50 ° or less.
<17> The machine-developed lithographic printing plate original plate according to any one of <1> to <16>, wherein the layer on the aluminum support contains hydroxycarboxylic acid or a salt thereof.
<18> The machine-developed lithographic printing plate original plate according to <17>, wherein the hydroxycarboxylic acid or a salt thereof contains a compound having two or more hydroxy groups.
<19> The machine-developed lithographic printing plate original plate according to <17> or <18>, wherein the hydroxycarboxylic acid or a salt thereof contains a compound having three or more hydroxy groups.
<20> The machine-developed lithographic printing plate original plate according to any one of <1> to <19>, wherein the polymerizable compound further contains a polymerizable compound having six functions or less.
<21> The machine-developed lithographic printing plate original plate according to any one of <1> to <20>, wherein the polymerization initiator contains an electron-accepting polymerization initiator.
<22> The machine-developed lithographic printing plate original plate according to <21>, wherein the LUMO value of the infrared absorber-the LUMO value of the electron-accepting polymerization initiator is 0.70 eV or less.
<23> The machine-developed lithographic printing plate original plate according to <21> or <22>, wherein the electron-accepting polymerization initiator contains a compound represented by the following formula (II).

In formula (II), X represents a halogen atom and R ³ represents an aryl group.

<24> The machine-developed lithographic printing plate original plate according to any one of <1> to <23>, wherein the polymerization initiator contains an electron donating type polymerization initiator.
<25> The machine-developed lithographic printing plate original plate according to <24>, wherein the HOMO value of the infrared absorber and the HOMO value of the electron donating polymerization initiator is 0.70 eV or less.
<26> The machine-developed lithographic printing plate original plate according to any one of <1> to <25>, wherein the image recording layer further contains a color former.
<27> The machine-developed lithographic printing plate original plate according to <26>, wherein the color former is an acid color former.
<28> The machine-developed lithographic printing plate original plate according to <27>, wherein the acid color former is a leuco dye.
<29> The machine-developed lithographic printing plate original plate according to <28>, wherein the leuco dye is a leuco dye having a phthalide structure or a fluorine structure.
<30> The machine-developed planographic plate according to <29>, wherein 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). Printed original plate.

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 is absent and Y ₂ is N, then X ₄ is absent, Ra ₁ represents a hydrogen atom, an alkyl group or an alkoxy group, and Rb ₁ to Rb ₄ are independent alkyl groups. Or represents an aryl group.

<31> The machine according to <29> or <30>, wherein the leuco dye having the phthalide structure or the fluorine structure is a compound represented by any of the following formulas (Le-4) to (Le-6). Top-developed lithographic printing plate original plate.

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 an alkyl group or an aryl group, respectively.

<32> Any one of <29> to <31>, wherein the leuco dye having the phthalide structure or the fluorine structure is a compound represented by any of the following formulas (Le-7) to (Le-9). The on-board development type lithographic printing plate original plate described in 1.

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 are independent hydrogen atoms and alkyl, respectively. Represents a group or an alkoxy group, Rb ₁ to Rb ₄ independently represent an alkyl group or an aryl group, and Rc ₁ and Rc ₂ each independently represent an aryl group.

<33> The machine-developed lithographic printing plate original plate according to <32>, wherein each of Ra ₁ to Ra ₄ is an alkoxy group independently.
<34> The machine-developed lithographic printing plate original plate according to <32> or <33>, wherein the leuco dye having the phthalide structure or the fluorine structure is a compound represented by the above formula (Le-8).
<35> The machine-developed lithographic printing plate original plate according to <34>, wherein X ₁ to X ₄ are hydrogen atoms and Y ₁ and Y ₂ are C.
<36> The machine-developed lithographic printing plate original plate according to <34> or <35>, wherein Rb ₁ and Rb ₂ are independently alkyl groups.
<37> The infrared absorber has an organic anion having δd of 16 or more, δp of 16 or more and 32 or less, and δh of 60% or less of δp in the solubility parameter of Hansen <1> to <36. > The on-board development type lithographic printing plate original plate described in any one of.
<38> The electron-accepting polymerization initiator has an organic anion in which δd in the solubility parameter of Hansen is 16 or more, δp is 16 or more and 32 or less, and δh is 60% or less of δp <23>. The machine-developed planographic printing plate original plate according to any one of <25>.
<39> The machine-developed lithographic printing plate original plate according to any one of <1> to <38>, wherein the image recording layer further contains polyvinyl acetal.
<40> The machine-developed lithographic printing plate original plate according to any one of <1> to <39>, wherein the image recording layer further contains a fluoroaliphatic group-containing copolymer.
<41> The on-machine development according to <40>, wherein the fluoroaliphatic group-containing copolymer has a structural unit formed of a compound represented by any of the following formulas (F1) and (F2). Planographic printing plate original plate.

In formulas (F1) and (F2), R ^F1 independently represents a hydrogen atom or a methyl group, and X independently represents an oxygen atom, a sulfur atom, or -N ( ^RF2 )-. m represents an integer of 1 ~ 6, n represents an integer of 1 ~ 10, l represents an integer of 0 ~ ^{10, R F2} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

<42> The fluoroaliphatic group-containing copolymer further has a structural unit formed by at least one compound selected from the group consisting of poly (oxyalkylene) acrylate and poly (oxyalkylene) methacrylate <41. > The on-board development type lithographic printing plate original plate described in.
<43> Any of <1> to <42>, wherein the image recording layer contains a compound having an ethylenically unsaturated bond value of 5.0 mmol / g or more as the polymerizable compound or the polymer having a polymerizable group. The on-board development type lithographic printing plate original plate described in one.
<44> The machine-developed lithographic printing plate original plate according to <43>, wherein the compound having an ethylenically unsaturated bond value of 5.0 mmol / g or more is a compound represented by the following formula (I).
Formula (I): X- (Y) _n
In formula (I), X represents an n-valent organic group having a hydrogen-bonding group, Y represents a monovalent group having two or more ethylenically unsaturated groups, and n represents an integer of two or more. The molecular weight of X / (molecular weight of Y × n) is 1 or less.
<45> The compound having an ethylenically unsaturated bond value of 5.0 mmol / g or more has at least one structure selected from the group consisting of an adduct structure, a biuret structure, and an isocyanurate structure <43> or <44> The on-machine development type lithographic printing plate original plate.
<46> The machine-developed lithographic printing plate original plate according to any one of <1> to <45>, wherein the polymerizable compound contains a compound having one or two ethylenically unsaturated groups.
<47> The aluminum support has an aluminum plate and an anodized film of aluminum arranged on the aluminum plate, and the average diameter of the micropores on the surface of the anodized film is more than 10 nm and 100 nm or less. The value of L ^* a ^* b ^* brightness L ^* in the surface of the anodized film on the image recording layer side is 70 to 100, whichever is one of <1> to <46>. On-board development type lithographic printing plate original plate described in.
<48> The micropore communicates with a large-diameter hole extending from the surface of the anodized film to a depth of 10 nm to 1,000 nm and the bottom of the large-diameter hole, and has a depth of 20 nm to 2 from the communicating position. It is composed of a small-diameter hole extending to a position of 000 nm, the average diameter of the large-diameter hole on the surface of the anodized film is 15 nm to 100 nm, and the average diameter of the small-diameter hole at the communication position is 13 nm. The machine-developed planographic printing plate original plate according to <47> below.
<49> Select from the process of exposing the machine-developed lithographic printing plate original plate according to any one of <1> to <48> like an image, and the group consisting of printing ink and dampening water on the printing machine. A method for producing a lithographic printing plate, which comprises a step of supplying at least one of the above and removing an image recording layer of a non-image portion.
<50> The step of exposing the machine-developed lithographic printing plate original plate according to any one of <1> to <48> like an image, and at least one selected from the group consisting of printing ink and dampening water. A lithographic printing method including a step of producing a lithographic printing plate by removing an image recording layer of a non-image portion on a printing machine, and a step of printing with the obtained lithographic printing plate.

According to the embodiment of the present invention, it is possible to provide an on-machine development type lithographic printing plate original plate having excellent on-machine developability and the inking property of the obtained lithographic printing plate.
Further, according to another embodiment of the present invention, it is possible to provide a method for producing a lithographic printing plate or a lithographic printing method using the above-mentioned machine-developed lithographic printing plate original plate.

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 alternating current 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 alternating current in the manufacturing method of the aluminum support which has an anodized 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 of including the numerical values described before and after it as a lower limit value and an 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 and 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 methacrylic, and "(meth) acryloyl" is a term that is used as a concept that includes both acryloyl and methacryloyl. Is.
Further, 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 are 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 for attaching 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.

(In-machine development type lithographic printing plate original plate)
The on-machine development type lithographic printing plate original plate (also simply referred to as “lithographic printing plate original plate”) according to the present disclosure has an aluminum support and an image recording layer on the aluminum support, and the image recording layer is formed on the aluminum support. , An infrared absorber, a polymerization initiator, a polymerizable compound having a molecular weight of less than 2,500, and a polymer having a molecular weight of 2,500 or more and having a polymerizable group, and the above polymerizable compound is polymerized with 7 or more functions. Contains sex compounds.
The on-machine development type lithographic printing plate original plate according to the present disclosure is a negative type lithographic printing plate original plate.

As a result of diligent studies by the present inventor, it has been found that by adopting the above configuration, it is possible to provide a machine-developing lithographic printing plate original plate having excellent on-machine developability and the resulting lithographic printing plate inlayability.
The detailed mechanism by which the above effect is obtained is unknown, but it is presumed as follows.
By containing a polymerizable compound having a molecular weight of less than 2,500 and a polymer having a molecular weight of 2,500 or more and having a polymerizable group, and the above-mentioned polymerizable compound further containing a polymerizable compound having 7 or more functionalities. While maintaining the top-developing property, more cross-linked structures are formed during curing, the hydrophobicity of the image portion where the image recording layer is cured is improved, and the obtained flat plate printing plate has excellent inking property, and the machine. It is estimated that an on-machine-developing flat plate printing plate original plate with excellent top-developing property can be obtained.

Further, the on-machine development type flat plate printing plate original plate according to the present disclosure contains a polymerizable compound having a molecular weight of less than 2,500 and a polymer having a molecular weight of 2,500 or more and having a polymerizable group, and further, the above-mentioned polymerizable property. When the compound contains a polymerizable compound having 7 or more functionalities, more crosslinked structures are formed at the time of curing, and the obtained flat plate printing plate is also excellent in printing resistance.
Further, the on-machine development type flat plate printing plate original plate according to the present disclosure contains a polymerizable compound having a molecular weight of less than 2,500 and a polymer having a molecular weight of 2,500 or more and having a polymerizable group, and further, the above-mentioned polymerizable property. When the compound contains a polymerizable compound having 7 or more functionalities, the hydrophobicity of the image portion formed by curing the image recording layer is improved, the color difference between the image portion and the non-image portion is larger, and the visibility is also improved. Excellent.

<Image recording layer>
The flat plate printing plate original plate according to the present disclosure has an image recording layer on the aluminum support, and the image recording layer contains an infrared absorber, a polymerization initiator, a polymerizable compound having a molecular weight of less than 2,500, and a molecular weight. It contains a polymer having a molecular weight of 2,500 or more and having a polymerizable group, and the polymerizable compound contains a polymerizable compound having 7 or more functionalities.
The image recording layer in the present disclosure is a negative image recording layer, and is preferably a water-soluble or water-dispersible negative image recording layer.
Further, the image recording layer in the present disclosure is preferably the outermost layer from the viewpoint of fillability, printing resistance, and on-machine developability.

In the lithographic printing plate original plate according to the present disclosure, the contact angle with water due to aerial water droplets on the outermost layer surface on the image recording layer side may be 20 ° to 85 ° from the viewpoint of fillability and on-machine developability. It is preferably 30 ° to 80 °, more preferably 40 ° to 70 °, and particularly preferably 50 ° to 65 °.
The method for measuring the contact angle with water by the aerial water droplet method on the outermost layer surface in the present disclosure shall be measured by the following method.
A contact angle meter DMC-MC3 (manufactured by Kyowa Surface Chemistry Co., Ltd.) was used for the measurement. After 1 μL of pure water is dropped on the outermost surface of the image recording layer side of the lithographic printing plate original plate, it is defined as the angle between the tangent line of the gas-liquid interface at the intersection of the dropped pure water and the plate surface and the plate surface. Further, the contact angle is calculated by performing the above measurement at three points on the same plate and calculating the average value of the values at the three points.

The details of each component contained in the image recording layer will be described below.

-Infrared absorber-
The image recording layer contains an infrared absorber.
Examples of the infrared absorber include pigments and dyes.
As the dye used as the infrared absorber, commercially available dyes and known dyes described in documents 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.
Particularly preferable of these dyes are cyanine pigments, squarylium pigments, pyrylium salts, nickel thiolate complexes, and indrenin cyanine pigments. Further, cyanine pigments and indorenin cyanine pigments can be mentioned. Of these, the cyanine pigment is particularly preferable.

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 0043 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.
Further, an infrared absorber that decomposes by infrared exposure (also referred to as "degradable infrared absorber") can be preferably used.
As the infrared absorber that decomposes by infrared exposure, those described in Japanese Patent Publication No. 2008-544322, International Publication No. 2016/027886, International Publication No. 2017/141882, or International Publication No. 2018/0432559 are preferable. Can be used for.

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.

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

<< Electron-accepting 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.
The electron-accepting polymerization initiator is preferably an infrared photosensitive polymerization initiator.
Examples of the electron-accepting radical polymerization initiator include (a) an organic halide, (b) a carbonyl compound, (c) an azo compound, (d) an organic peroxide, (e) a metallocene compound, and (f) an azide compound. , (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 above-mentioned 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 aromatic. 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.

Further, as the counter anion of the iodonium salt compound and the sulfonium salt compound, 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.

Further, the electron-accepting polymerization initiator may contain a compound represented by the following formula (II) from the viewpoint of developability and UV printing resistance in the obtained lithographic printing plate.

In formula (II), X represents a halogen atom and R ³ represents an aryl group.

Specific examples of X in the formula (II) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Of these, a chlorine atom or a bromine atom is preferable because it has excellent sensitivity, and a bromine atom is particularly preferable.
Further, in formula (II), R ^3, from the viewpoint of excellent balance between sensitivity and storage stability, an aryl group substituted with an amide group.

Specific examples of the electron-accepting polymerization initiator represented by the above formula (II) include compounds represented by the following formula, but the present disclosure is not limited thereto.

The minimum empty orbital (LUMO) of the electron-accepting polymerization initiator is preferably −3.00 eV or less, preferably −3.02 eV, from the viewpoints of sensitivity, fillability, printing resistance, and on-machine developability. The following is more preferable.
Further, as the lower limit, it is preferably -3.80 eV or more, and more preferably -3.60 eV or more.

In the present disclosure, the MO (molecular orbital) energy of the highest occupied orbital (HOMO) and the lowest empty orbital (LUMO) is calculated by the following method.
First, free counterions in the compound to be calculated are excluded from the calculation. For example, the cationic one-electron accepting polymerization initiator and the cationic infrared absorber exclude the counter anion, and the anionic one-electron donating polymerization initiator excludes the counter cation from the calculation target. The term "free" as used herein means that the target compound and its counterion are not covalently linked.
Quantum chemistry calculation software Gaussian09 is used, and structural optimization is performed by DFT (B3LYP / 6-31G (d)).
The MO (molecular orbital) energy calculation is performed by DFT (B3LYP / 6-31 + G (d, p) / CPCM (solvent = methanol)) with the structure obtained by the above structure optimization.
The MO energy Ebare (unit: hartree) obtained by the above MO energy calculation is converted into Escaled (unit: eV) used as the values of HOMO and LUMO in the present disclosure by the following formula.
Escaled = 0.823168 x 27.2114 x Ebare-1.07634
Note that 27.2114 is simply a coefficient for converting hartree to eV, 0.823168 and −1.07634 are adjustment coefficients, and HOMO and LUMO of the compound to be calculated are calculated values. Determine to suit.

Specific examples of the electron-accepting polymerization initiator include I-1 to I-3 described in Examples described later, but it goes without saying that the present invention is not limited to these.

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.

-Relationship between electron-accepting polymerization initiator and infrared absorber-
The image recording layer in the present disclosure contains the electron-accepting polymerization initiator and the infrared absorber from the viewpoint of improving sensitivity and suppressing UV plate skipping, and is an infrared absorber LUMO-the electron-accepting polymerization initiator. The value of LUMO is preferably 1.00 eV or less, more preferably 0.70 eV or less, and particularly preferably 0.70 eV to −0.10 eV.
A negative value means that the LUMO of the electron-accepting polymerization initiator is higher than that of the infrared absorber LUMO.

<< Electron donation type 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 arylate 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-phenylglycines (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 orbital (HOMO) of the electron donating type polymerization initiator used in the present disclosure is -6.00 eV or more from the viewpoint of sensitivity, fillability, print resistance, and on-machine developability. It is preferably −5.95 eV or higher, more preferably −5.93 eV or higher, and even more preferably −5.93 eV or higher.
The upper limit is preferably −5.00 eV or less, and more preferably −5.40 eV or less.

As the electron donating type polymerization initiator, only one kind may be added, or two or more kinds 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 to 25% by mass, and further 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-
The image recording layer in the present disclosure contains the electron donating type polymerization initiator and the infrared absorber from the viewpoints of sensitivity, fillability, printing resistance, and on-machine developability, and the infrared absorber HOMO-the above. The HOMO value of the electron donating polymerization initiator 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-
The infrared absorber in the present disclosure has δd of 16 or more, δp of 16 to 32, and δp in the solubility parameter of Hansen from the viewpoints of sensitivity, fillability, print resistance, and on-machine developability. , Δh is preferably 60% or less of δp and has an organic anion.
The electron-accepting polymerization initiator in the present disclosure has a δd of 16 or more and a δp of 16 to 32 in the solubility parameter of Hansen from the viewpoints of sensitivity, fillability, print resistance, and on-machine developability. It is preferable to have an organic anion in which δh is 60% or less of δp.

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 polarity 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 Hansen's solubility parameters, see Charles M. 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.

The above-mentioned I-1 to I-26 are preferable as specific examples of the organic anion in which δd in the solubility parameter of Hansen is 16 or more, δp is 16 to 32, and δh is 60% or less of δp. Needless to say, it is not limited to these.

-Polymerizable compounds with a molecular weight of less than 2,500-
The image recording layer contains a polymerizable compound having a molecular weight of less than 2,500 (also simply referred to as “polymerizable compound”). In addition, the above-mentioned polymerizable compound contains a polymerizable compound having 7 or more functionalities.
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. Polymerizable compounds have chemical forms such as, for example, monomers, prepolymers, ie dimers, trimers or oligomers, or mixtures thereof.

The polymerizable compound preferably contains a polymerizable compound having 7 or more functionalities, and further preferably contains a polymerizable compound having 6 or less functionalities from the viewpoint of on-machine developability.
Further, the polymerizable compound preferably contains an ethylenically unsaturated compound having 7 or more functionalities, and an ethylenically unsaturated compound having 7 or more functionalities, from the viewpoints of onset property, printing resistance and on-machine developability. , And it is more preferable to contain an ethylenically unsaturated compound having 6 or less functionalities.
Further, the polymerizable compound preferably contains a polymerizable compound having 10 or more functionalities, and may contain a polymerizable compound having 12 or more functionalities, from the viewpoints of fillability, printing resistance, and on-machine developability. It is more preferable to contain a polymerizable compound having 15 or more functionalities, and it is particularly preferable to contain a polymerizable compound having 15 or more functionalities and 30 or less functionalities.

Examples of the polymerizable compound include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters thereof, amides, etc., and are preferably unsuitable. Esters of saturated carboxylic acid and polyhydric alcohol compound, and amides of unsaturated carboxylic acid and polyhydric amine compound 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 an unsaturated carboxylic acid ester or amide having a polyelectron substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, an amine or a thiol, 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 per molecule described in JP-A-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, Ethylene described in Japanese Patent Application Laid-Open No. 58-49860, Japanese Patent Publication No. 56-17654, Japanese Patent Publication No. 62-39417, Japanese Patent Application Laid-Open No. 62-39418, Japanese Patent Application Laid-Open No. 2000-250211, and Japanese Patent Application Laid-Open No. 2007-94138. Urethane compounds having an oxide-based skeleton, urethane compounds having a hydrophilic group described in US Pat. No. 7,153,632, JP-A-8-505598, JP-A-2007-293221, JP-A-2007-293223. Kind is also suitable.

-Specific compound B1-
From the viewpoint of enhancing printing resistance, the image recording layer is an ethylenically unsaturated bond as a polymerizable compound having a molecular weight of less than 2,500 or a polymer having a molecular weight of 2,500 or more and having a polymerizable group, which will be described later. It is preferable to contain a compound having a valence (also referred to as “C = C valence”) of 5.0 mmol / g or more (hereinafter, also referred to as specific compound B1).
The ethylenically unsaturated bond value of the specific compound B1 is preferably 5.5 mmol / g or more, and more preferably 6.0 mmol / g or more. The upper limit of the ethylenically unsaturated bond value of the specific compound B1 is, for example, 10.0 mmol / g or less, and more preferably 8.5 mmol / g or less.

Here, the ethylenically unsaturated bond value of the compound in the present disclosure is determined by the following method. First, for a compound having a predetermined sample amount (for example, 0.2 g), the structure of the compound is specified by using, for example, thermal decomposition GC / MS, FT-IR, NMR, TOF-SIMS, etc., and ethylenically unsaturated. Find the total amount (mmol) of the groups. The ethylenically unsaturated bond value of a compound is calculated by dividing the total amount (mmol) of the determined ethylenically unsaturated groups by the sample amount (g) of the compound.

The specific compound B1 is preferably a compound represented by the following formula (I) from the viewpoint of satisfying the above C = C valence.
Formula (I): X- (Y) n
In formula (I), X represents an n-valent organic group having a hydrogen-bonding group, Y represents a monovalent group having two or more ethylenically unsaturated groups, and n represents an integer of two or more. The molecular weight of X / (molecular weight of Y × n) is 1 or less.

The hydrogen-bonding group in X of the formula (I) is not particularly limited as long as it is a hydrogen-bondable group, and whether it is a hydrogen-bond-donating group or a hydrogen-bond-accepting group, both of them. It may be. Examples of the hydrogen-bonding group include a hydroxy group, a carboxy group, an amino group, a carbonyl group, a sulfonyl group, a urethane group, a urea group, an imide group, an amide group, a sulfonamide group and the like. Among them, the hydrogen-bonding group is at least one group selected from the group consisting of a urethane group, a urea group, an imide group, an amide group, and a sulfonamide group from the viewpoint of on-machine developability and print resistance. It is more preferable to contain at least one group selected from the group consisting of a urethane group, a urea group, an imide group, and an amide group, and more preferably than the group consisting of a urethane group, a urea group, and an imide group. It is more preferably at least one selected group, and particularly preferably containing at least one group selected from the group consisting of urethane groups and urea groups.

X in the formula (I) is preferably an organic group having no ethylenically unsaturated bond.
Further, X in the formula (I) is a monovalent to n-valent aliphatic hydrocarbon group, a monovalent to n-valent aromatic hydrocarbon group, a urethane bond, or a urea from the viewpoint of on-machine developability and printing resistance. It is preferably a group that combines two or more structures selected from the group consisting of a bond, a biuret bond, and an allophanate bond, and is preferably a monovalent to n-valent aliphatic hydrocarbon group and a monovalent to n-valent aromatic group. It is more preferable that the group is a combination of two or more structures selected from the group consisting of a hydrocarbon group, a urethane bond, a urea bond, and a biuret bond.

X in the formula (I) is a quantified product in which a polyfunctional isocyanate compound is increased in a large amount (including an adducted body of a polyfunctional alcohol compound such as a trimethylolpropane adduct) from the viewpoint of on-machine developability and print resistance. It is preferable that the group is a group obtained by removing the terminal isocyanate group from the group, and is a group obtained by removing the terminal isocyanate group from a quantifier (including an adduct of a polyfunctional alcohol compound) in which a bifunctional isocyanate compound is abundant. Is more preferable, and a group in which the terminal isocyanate group is removed from a quantifier (including an adduct of a polyfunctional alcohol compound) in which hexamethylene diisocyanate is increased is particularly preferable.

The molecular weight of X in the formula (I) is preferably 100 to 1,000, more preferably 150 to 800, and particularly preferably 150 to 500, from the viewpoint of on-machine developability and print resistance.

The ethylenically unsaturated group in Y of the formula (I) is not particularly limited, and from the viewpoint of reactivity, on-machine developability, and print resistance, a vinylphenyl group, a vinyl ester group, a vinyl ether group, an allyl group, ( It is preferably at least one group selected from the group consisting of a meta) acryloxy group and a (meth) acrylamide group. From the same viewpoint as above, the ethylenically unsaturated group in Y of the formula (I) is at least one group selected from the group consisting of a vinylphenyl group, a (meth) acryloxy group, and a (meth) acrylamide group. Is more preferable, and it is more preferable that it is a (meth) acrylate group. That is, the ethylenically unsaturated group in Y of the formula (I) preferably contains a (meth) acryloxy group from the viewpoint of on-machine developability and print resistance.

Y in the formula (I) is preferably a group having three or more (meth) acryloxy groups, more preferably a group having five or more (meth) acryloxy groups, and five or more twelve. It is more preferable that the group has the following (meth) acryloxy group.

Y in the formula (I) may have a structure represented by the following formula (Y-1) or the formula (Y-2) from the viewpoint of on-machine developability and print resistance.

In the formula (Y-1) and the formula (Y-2), R independently represents an acrylic group or a methacrylic group, and the wavy line portion represents the bonding position with another structure.

In the formula (Y-1) or the formula (Y-2), it is preferable that all Rs have the same group. Further, in the formula (Y-1) or the formula (Y-2), R is preferably an acrylic group.

Further, it is preferable that the n Ys in the formula (I) are all the same group.

The molecular weight of Y in the formula (I) is preferably 200 or more and 1,000 or less, and more preferably 250 or more and 800 or less, from the viewpoint of on-machine developability and print resistance.

N in the formula (I) is an integer of 2 or more, and is more preferably 2 to 3 from the viewpoint of on-machine developability and print resistance.

The molecular weight of X / (molecular weight of Y × n) is 1 or less, preferably 0.01 to 0.8, preferably 0.1 to 0.5, from the viewpoint of on-machine developability and print resistance. More preferably.

As described above, the structure of the specific compound B1 preferably includes a structure in which the terminal isocyanate group of the quantifier (including the adduct) of the polyfunctional isocyanate compound is sealed with a compound having an ethylenically unsaturated group. .. Among them, as the quantifier of the polyfunctional isocyanate compound, the quantifier of the bifunctional isocyanate compound is preferable.

Further, from the viewpoint of on-machine developability and print resistance, the specific compound B1 is a polyfunctional ethylene having a hydroxy group (also referred to as a hydroxyl group) at the end of the terminal isocyanate group of the multimerized product in which the polyfunctional isocyanate compound is increased in quantity. It is preferably a compound obtained by reacting a sex unsaturated compound. Further, from the same viewpoint as above, the specific compound B1 is a polyfunctional ethylenic compound having a hydroxy group at the terminal isocyanate group of a multimeric compound (including an adduct compound of a polyfunctional alcohol compound) in which a difunctional isocyanate compound is increased in quantity. It is more preferable that the compound is obtained by reacting an unsaturated compound. Further, from the same viewpoint as above, the specific compound B1 is a polyfunctional ethylenically non-polyfunctional compound having a hydroxy group at the terminal isocyanate group of the multimer (including the adduct of the polyfunctional alcohol compound) in which hexamethylene diisocyanate is increased. It is particularly preferable that the compound is obtained by reacting a saturated compound.

The polyfunctional isocyanate compound is not particularly limited, and known compounds can be used, and may be an aliphatic polyfunctional isocyanate compound or an aromatic polyfunctional isocyanate compound. Specific examples of the polyfunctional isocyanate compound include 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, and 1,3-. Cyclopentane diisocyanate, 9H-fluorene-2,7-diisocyanate, 9H-fluoren-9-on-2,7-diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylenediisocyanate, trilen-2 , 4-Diisocyanate, Trilen-2,6-Diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 2,2-bis (4-isocyanatophenyl) hexafluoropropane, 1,5-di Isocyanatonaphthalene, dimers of these polyisocyanates, trimmers (isocyanurate bonds) and the like are preferably mentioned. Further, a biuret compound obtained by reacting the above polyisocyanate compound with a known amine compound may be used.
The polyfunctional ethylenically unsaturated compound having a hydroxy group is preferably a trifunctional or higher functional ethylenically unsaturated compound having a hydroxy group, and is a pentafunctional or higher functional ethylenically unsaturated compound having a hydroxy group. Is more preferable. The polyfunctional ethylenically unsaturated compound having a hydroxy group is preferably a polyfunctional (meth) acrylate compound having a hydroxy group.

The specific compound B1 preferably has at least one structure selected from the group consisting of an adduct structure, a biuret structure, and an isocyanurate structure from the viewpoint of on-machine developability and print resistance. From the same viewpoint as above, it is more preferable that the specific compound B1 has at least one structure selected from the group consisting of a trimethylolpropane adduct structure, a biuret structure, and an isocyanurate structure, and the trimethylolpropane adduct structure is formed. It is particularly preferable to have.

From the viewpoint of on-machine developability and print resistance, the specific compound B1 preferably has a structure represented by any of the following formulas (A-1) to (A-3), and the following formula (A-). It is more preferable to have the structure represented by 1).

In the formula (A-1), ^RA1 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and the wavy line portion represents a bond position with another structure.

R ^A1 in the formula (A1), from the viewpoint of on-press development property and printing durability, a hydrogen atom, or preferably an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 3 carbon atoms It is more preferably present, more preferably a methyl group or an ethyl group, and particularly preferably an ethyl group.

The specific compound B1 is preferably a (meth) acrylate compound having a urethane group, that is, a urethane (meth) acrylate oligomer from the viewpoint of on-machine developability and print resistance.

The specific compound B1 may be an oligomer having a polyester bond (hereinafter, also referred to as a polyester (meth) acrylate oligomer) as long as the ethylenically unsaturated bond value is 5.0 mmol / g or more, or an epoxy residue may be used. It may be an oligomer having an oligomer (hereinafter, also referred to as an epoxy (meth) acrylate oligomer).
Here, the epoxy residues in the epoxy (meth) acrylate oligomer are as described above.

The number of ethylenically unsaturated groups in the polyester (meth) acrylate oligomer which is the specific compound B1 is preferably 3 or more, and more preferably 6 or more.

As the epoxy (meth) acrylate oligomer which is the specific compound B1, a compound containing a hydroxy group in the compound is preferable. The number of ethylenically unsaturated groups in the epoxy (meth) acrylate oligomer is preferably 2 to 6, and more preferably 2 to 3. The epoxy (meth) acrylate oligomer can be obtained, for example, by reacting a compound having an epoxy group with acrylic acid.

The molecular weight of the specific compound B1 (weight average molecular weight when having a molecular weight distribution) is preferably more than 1,000, more preferably 1,100 to 10,000, and even more preferably 1,100 to 5,000.

As the specific compound B1, a synthetic product or a commercially available product may be used.
Specific examples of the specific compound B1 include, for example, the following commercially available products, but the specific compound B1 used in the present disclosure is not limited thereto. The number of functional groups (or average number of functional groups) and C = C valence of the ethylenically unsaturated group are shown in parentheses.
Specific examples of the specific compound B1 include U-10HA (number of functional groups: 10, C = C value: 8 mmol / g) and U-15HA (number of functional groups: 15, C = C value) manufactured by Shin Nakamura Chemical Industry Co., Ltd. : 6 mmol / g), UA-510H manufactured by Kyoeisha Chemical Co., Ltd. (number of functional groups: 10, C = C value: 8 mmol / g), KRM8452 manufactured by Daicel Ornex Co., Ltd. (number of functional groups: 10, C = C) Urethane (meth) such as CN8885NS (number of functional groups: 9, C = C value: 6 mmol / g) and CN9013NS (number of functional groups: 9, C = C value: 6 mmol / g) manufactured by Sartmer Co., Ltd. Examples include acrylate oligomers.
Specific examples of the specific compound B1 include NK oligo EA-7420 / PGMAC (number of functional groups: 10 to 15, C = C value: 5 mmol / g) manufactured by Shin-Nakamura Chemical Industry Co., Ltd., and CN153 manufactured by Sartmer Co., Ltd. Epoxy (meth) acrylate oligomers such as (C = C value: 5 mmol / g) can be mentioned.
Further, specific examples of the specific compound B1 include polyester (meth) acrylate oligomers such as CN2267 (C = C value: 5 mmol / g) manufactured by Sartmer.

When the specific compound B1 is used, the content of the specific compound B1 in the image recording layer with respect to the total mass of the polymerizable compound is preferably 10% by mass to 100% by mass, preferably 50% by mass to 100% by mass. Is more preferable, and 80% by mass to 100% by mass is further preferable.

-Specific compound B2-
The polymerizable compound may contain, as a low molecular weight compound, a compound having one or two ethylenically unsaturated bonding groups (hereinafter, also referred to as a specific compound B2).
A preferred embodiment of the ethylenically unsaturated group contained in the specific compound B2 is the same as that of the ethylenically unsaturated group in the specific compound B1.
Further, the specific compound B2 is preferably a compound having two ethylenically unsaturated bonding groups (that is, a bifunctional polymerizable compound) from the viewpoint of suppressing a decrease in on-machine developability.

The specific compound B2 is preferably a methacrylate compound, that is, a compound having a methacryloxy group, from the viewpoint of on-machine developability and print resistance.

The specific compound B2 preferably contains an alkyleneoxy structure or a urethane bond from the viewpoint of on-machine developability.

The molecular weight (weight average molecular weight when having a molecular weight distribution) of the specific compound B2 is preferably 50 or more and less than 1,000, more preferably 200 to 900, and more preferably 250 to 800. More preferred.

Specific examples of the specific compound B2 are given below, but the specific compound B2 used in the present disclosure is not limited thereto. In the compound of the following (2), for example, n + m = 10.

As the specific compound B2, commercially available products shown below may be used, but the specific compound B2 used in the present disclosure is not limited thereto.
Specific examples of the specific compound B2 include BPE-80N (compound of (1) above) manufactured by Shin Nakamura Chemical Industry Co., Ltd., BPE-100, BPE-200, BPE-500, and CN104 manufactured by Sartmer Co., Ltd. Examples thereof include ethoxylated bisphenol A dimethacrylate such as the compound of 1).
Specific examples of the specific compound B2 include ethoxylated bisphenol A diacrylates such as A-BPE-10 (compound of (2) above) manufactured by Shin Nakamura Chemical Industry Co., Ltd. and A-BPE-4. ..
Further, specific examples of the specific compound B2 include bifunctional methacrylate such as FST 510 manufactured by AZ Electronics.

Here, the above "FST 510" is a reaction product of 1 mol of 2,2,4-trimethylhexamethylene diisocyanate and 2 mol of hydroxyethyl methacrylate, and is a solution of the compound of the above (3) in an 82% by mass of methyl ethyl ketone. is there.

The content of the specific compound B2 is preferably 1% by mass to 60% by mass, and 5% by mass to 55% by mass, based on the total mass of the image recording layer, from the viewpoint of on-machine developability and print resistance. Is more preferable, and 5% by mass to 50% by mass is further preferable.
When the specific compound B2 is used, the content of the specific compound B2 with respect to the total mass of the polymerizable compound in the image recording layer is preferably 10% by mass to 100% by mass, preferably 50% by mass to 100% by mass. Is more preferable, and 80% by mass to 100% by mass is further preferable.

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 by mass%.

In the image recording layer, when the content of the polymer having a polymerizable group is Mp and the content of the polymerizable compound having 7 or more functionalities is Mm, the values of Mm / Mp are the onset property and printing resistance. From the viewpoint of property and on-machine developability, it is preferably 0.01 or more, more preferably 0.015 or more, further preferably 0.015 or more and 0.2 or less, and 0. It is particularly preferable that it is 015 or more and 0.1 or less.

-A polymer having a molecular weight of 2,500 or more and having a polymerizable group-
The image recording layer contains a polymer having a molecular weight of 2,500 or more and having a polymerizable group (also simply referred to as a "polymer having a polymerizable group").
The polymerizable group is preferably an ethylenically unsaturated group from the viewpoint of fillability, printing resistance and on-machine developability, and is preferably an ethylenically unsaturated group, a (meth) acryloxy group, a (meth) acrylamide group, or a vinyl ester. It is more preferably a group, a vinyl ether group, an allyl group, or a styryl group (vinyl aromatic group), and particularly preferably a (meth) acryloxy group or a (meth) acrylamide group.
The weight average molecular weight of the polymer having a polymerizable group is preferably 5,000 or more, and more preferably 10,000 or more, from the viewpoint of fillability, print resistance, and on-machine developability. It is preferable, and it is particularly preferable that it is 15,000 or more and 200,000 or less.

The polymer having the above-mentioned polymerizable group is not particularly limited and may be an addition polymerization type resin or a polycondensation resin, but from the viewpoint of meat-forming property, printing resistance and on-machine developability. , The addition polymerization type resin is preferable, and the acrylic resin is more preferable.
The "acrylic resin" in the present disclosure refers to a (meth) acrylic compound (for example, (meth) acrylate compound, (meth) acrylamide compound, (meth) acrylonitrile, etc.) in an amount of 50% by mass or more based on the total mass of the polymer. It means a polymer having a structural unit formed by, and it is preferable that 70% by mass or more is a polymer having a structural unit formed by a (meth) acrylic compound, and 80% by mass or more is a (meth) acrylic compound. More preferably, it is a polymer having the formed structural units.
Further, the polymer having a polymerizable group preferably contains a styrene-acrylonitrile copolymer, and more preferably contains styrene-acrylonitrile copolymer particles, from the viewpoint of carving property.

The shape of the polymer having the polymerizable group is not particularly limited, and may be polymer particles having the polymerizable group or a binder polymer having the polymerizable group, but has the polymerizable group. The polymer preferably contains polymer particles having a polymerizable group from the viewpoints of fillability, print resistance, and on-machine developability, with respect to the total mass of the polymer having the polymerizable group in the image recording layer. The content of the polymer particles having a polymerizable group is more preferably 50% by mass or more, further preferably 65% by mass or more, particularly preferably 80% by mass or more, and 90% by mass or more. Most preferably.

The addition polymerization type resin preferably has a structural unit formed of an aromatic vinyl compound and a structural unit formed of an acrylonitrile compound from the viewpoint of meat-forming property and on-machine developability.

[Constituent units formed of aromatic vinyl compounds]
The addition polymerization type resin has 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 A1 is preferably mentioned.

In the formula A1, are each R ^A1 and R ^A2 independently represents a hydrogen atom or an alkyl group, Ar represents an aromatic ring group, R ^A3 represents a substituent, n represents the maximum number of substituents below integer Ar ..
In the formula A1, ^RA1 and ^RA2 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 A1, Ar is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.
In the formula A1, ^RA3 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.
When a plurality of ^RA3s are present in the formula A1, the plurality of ^RA3s may be the same or different from each other.
In the formula A1, n is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0.

The content of the structural unit formed by the aromatic vinyl compound in the addition polymerization type resin is preferably 15% by mass to 85% by mass, preferably 30% by mass to 70% by mass, based on the total mass of the addition polymerization type resin. More preferably.

[Constituent unit formed by acrylonitrile compound]
The addition polymerization type resin has a structural unit formed of an acrylonitrile compound.
Examples of the acrylonitrile compound include (meth) acrylonitrile, and acrylonitrile is preferable.

Further, as the structural unit formed by the acrylonitrile compound, the structural unit represented by the following formula B1 is preferably mentioned.

In formula B1, ^RB1 represents a hydrogen atom or an alkyl group.
In the formula B1, ^RB1 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

The content of the structural unit formed by the acrylonitrile compound in the addition polymerization type resin is preferably 15% by mass to 85% by mass, preferably 30% by mass to 70% by mass, based on the total mass of the addition polymerization type resin. More preferably.

[Constituent unit formed of N-vinyl heterocyclic compound]
From the viewpoint of printing resistance and chemical resistance, the addition polymerization type resin preferably further has a structural unit formed of the N-vinyl heterocyclic compound.
Examples of the N-vinyl heterocyclic compound include N-vinylpyrrolidone, N-vinylcarbazole, N-vinylpyrrole, N-vinylphenothiazine, N-vinylsuccinimide, N-vinylphthalimide, N-vinylcaprolactam, and N-vinylcaprolactam. Vinyl imidazole is mentioned, and N-vinylpyrrolidone is preferable.

Further, as the structural unit formed by the N-vinyl heterocyclic compound, the structural unit represented by the following formula C1 is preferably mentioned.

In the formula C1, Ar ^N represents a heterocyclic structure containing a nitrogen atom, a nitrogen atom in Ar ^N is bonded to the carbon atoms indicated by *.
In the formula C1, the heterocyclic structure represented by Ar ^N is preferably a pyrrolidone ring, a carbazole ring, a pyrrole ring, a phenothiazine ring, a succinimide ring, a phthalimide ring, a caprolactam ring, and an imidazolid ring, and is preferably a pyrrolidone ring. Is more preferable.
Further, the heterocyclic structure represented by Ar ^N may have a known substituent.

The content of the structural unit formed by the N-vinyl heterocyclic compound in the addition polymerization type resin is preferably 5% by mass to 50% by mass, preferably 10% by mass or more, based on the total mass of the addition polymerization type resin. More preferably, it is 40% by mass.

[Constituent unit having a polymerizable group]
The addition polymerization type resin preferably has a structural unit having a polymerizable group, and more preferably has a structural unit having an ethylenically unsaturated group.
The ethylenically unsaturated group is not particularly limited, and examples thereof include a vinyl group, an allyl group, a vinylphenyl group, a (meth) acrylamide group, a (meth) acryloyloxy group, and the like, and from the viewpoint of reactivity, (meth) ) It is preferably an acrylamide group.
The structural unit having an ethylenically unsaturated group can be introduced into the addition polymerization type resin by a polymer reaction or copolymerization. Specifically, for example, a method of reacting a polymer having a structural unit having a carboxy group such as methacrylic acid with a compound having an epoxy group and an ethylenically unsaturated group (for example, glycidyl methacrylate), a hydroxy group. It can be introduced by a method of reacting a polymer having a structural unit having a group having an active hydrogen such as, etc. with a compound having an isocyanate group and an ethylenically unsaturated group (2-isocyanatoethyl methacrylate, etc.) or the like. ..
Further, the structural unit having an ethylenically unsaturated group is such that a compound having a carboxy group and an ethylenically unsaturated group is reacted with a polymer into which a structural unit having an epoxy group such as glycidyl (meth) acrylate is introduced. It may be introduced into an addition polymerization type resin by a method.
Further, the structural unit having an ethylenically unsaturated group may be introduced into the addition polymerization type resin by using a monomer containing a partial structure represented by the following formula d1 or the following formula d2, for example. Specifically, for example, after polymerization using at least the above-mentioned monomer, an ethylenically unsaturated group is formed on the partial structure represented by the following formula d1 or the following formula d2 by an elimination reaction using a basic compound. By doing so, a structural unit having an ethylenically unsaturated group is introduced into the addition polymerization type resin.

In the formula d1 and wherein d2, ^{R d} represents a hydrogen atom or an alkyl group, ^{A d} represents a halogen atom, ^{X d} is -O- or -NR ^N - represents, ^{R N} represents a hydrogen atom or an alkyl group , * Represent the binding site with other structures.
In formulas d1 and d2, R ^d is preferably a hydrogen atom or a methyl group.
In the formula d1 and wherein d2, A ^d is a chlorine atom, a bromine atom, or preferably a iodine atom.
In formulas d1 and d2, X ^d is preferably —O—. X ^d is -NR ^N - when referring to, ^{R N} is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom.

Examples of the structural unit having an ethylenically unsaturated group include a structural unit represented by the following formula D1.

In formula D1, L ^D1 represents a single bond or a divalent linking group, L ^D2 represents an m + 1 valent linking group, and X ^D1 and X ^D2 independently represent -O- or -NR ^N- , respectively. R ^N represents a hydrogen atom or an alkyl group, in each of R ^D1 and R ^D2 independently represent a hydrogen atom or a methyl group, m represents an integer of 1 or more.

In the formula D1, ^LD1 is preferably a single bond. When ^LD1 represents a divalent linking group, an alkylene group, an arylene group or a divalent group in which two or more of these are bonded is preferable, and an alkylene group or a phenylene group having 2 to 10 carbon atoms is more preferable.
In the formula D1, L ^D2 is preferably a group represented by any of the following formulas D2 to D6.
In the formula D1, it is preferable that both X ^D1 and X ^D2 are −O−. ^Further, at least one of ^{X D1} and ^{X D2} is -NR ^N - when referring to, ^{R N} is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom.
In the formula D1, ^RD1 is preferably a methyl group.
In the formula D1, at least one of m R ^D2 is preferably a methyl group.
In the formula D1, m is preferably an integer of 1 to 4, more preferably 1 or 2, and even more preferably 1.

In formulas D2 to D6, L ^D3 to L ^D7 represent divalent linking groups, L ^D5 and L ^D6 may be different, and * represents the binding site with X ^{D1 in} formula D1 and wavy lines. Represents the binding site with X ^D2 in the formula D1.

In the formula D3, ^LD3 is preferably an alkylene group, an arylene group, or a group in which two or more of these are bonded, and an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a group in which two or more of these are bonded. More preferred.
In the formula D4, ^LD4 is preferably an alkylene group, an arylene group, or a group in which two or more of these are bonded, and an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a group in which two or more of these are bonded. More preferred.
In the formula D5, ^LD5 is preferably an alkylene group, an arylene group, or a group in which two or more of these are bonded, and an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a group in which two or more of these are bonded. More preferred.
In the formula D6, ^LD6 is preferably an alkylene group, an arylene group, or a group in which two or more of these are bonded, and an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a group in which two or more of these are bonded. More preferred.
In the formula D7, ^LD7 is preferably an alkylene group, an arylene group, or a group in which two or more of these are bonded, and an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a group in which two or more of these are bonded. More preferred.

Specific examples of the structural unit having an ethylenically unsaturated group are shown below, but the structural unit having an ethylenically unsaturated group contained in the binder polymer according to the present disclosure is not limited to this. In the specific examples below, R independently represents a hydrogen atom or a methyl group.

The content of the structural unit having a polymerizable group in the addition polymerization type resin is preferably 5% by mass to 60% by mass, preferably 10% by mass to 30% by mass, based on the total mass of the addition polymerization type resin. Is more preferable.

[Constituent unit having an acid group]
The addition polymerization type resin may contain a structural unit having an acid group, but from the viewpoint of on-machine developability and ink penetration property, it is preferable not to contain a structural unit having an acid group.
Specifically, the content of the structural unit having an acid group in the addition polymerization type resin is preferably 20% by mass or less, more preferably 10% by mass or less, and preferably 5% by mass or less. More preferred. The lower limit of the content is not particularly limited and may be 0% by mass.
The acid value of the addition polymerization type resin is preferably 160 mgKOH / g or less, more preferably 80 mgKOH / g or less, and even more preferably 40 mgKOH / g or less. The lower limit of the acid value is not particularly limited, and may be 0 mgKOH / g.
In the present disclosure, the acid value is determined by a measuring method based on JIS K0070: 1992.

[Constituent unit having a hydrophobic group]
The addition polymerization type resin may contain a structural unit containing a hydrophobic group from the viewpoint of ink penetration.
Examples of the hydrophobic group include an alkyl group, an aryl group, an aralkyl group and the like.
As the structural unit containing a hydrophobic group, a structural unit formed of an alkyl (meth) acrylate compound, an aryl (meth) acrylate compound, or an aralkyl (meth) acrylate compound is preferable, and the structural unit is formed of an alkyl (meth) acrylate compound. The structural unit is more preferable.
The alkyl group in the alkyl (meth) acrylate compound preferably has 1 to 10 carbon atoms. The alkyl group may be linear or branched, and may have a cyclic structure. Examples of the alkyl (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and dicyclopentanyl (meth) acrylate. Can be mentioned.
The aryl group in the aryl (meth) acrylate compound preferably has 6 to 20 carbon atoms, and more preferably a phenyl group. Moreover, the above-mentioned aryl group may have a known substituent. As the aryl (meth) acrylate compound, phenyl (meth) acrylate is preferably mentioned.
The alkyl group in the aralkyl (meth) acrylate compound preferably has 1 to 10 carbon atoms. The alkyl group may be linear or branched, and may have a cyclic structure. The aryl group in the aralkyl (meth) acrylate compound preferably has 6 to 20 carbon atoms, and more preferably a phenyl group. Benzyl (meth) acrylate is preferably mentioned as the aralkyl (meth) acrylate compound.

The content of the structural unit having a hydrophobic group in the addition polymerization type resin is preferably 5% by mass to 50% by mass, preferably 10% by mass to 30% by mass, based on the total mass of the addition polymerization type resin. Is more preferable.

[Cross-linked structure]
The addition polymerization type resin preferably has a crosslinked structure.
The crosslinked structure is not particularly limited, but is polymerizable with 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 in the resin. It is preferably introduced into the resin a1.
The functional number of the polyfunctional ethylenically unsaturated compound is preferably 2 to 15, more preferably 3 to 10, and further preferably 4 to 10 from the viewpoint of suppressing the occurrence of plate skipping. It is preferably 5 to 10, and particularly preferably 5 to 10.
In other words, the structural unit having a crosslinked structure is preferably a bifunctional to 15-functional bifurcated unit from the viewpoint of improving sensitivity and suppressing the occurrence of plate skipping, and is preferably trifunctional to 10-functional. It is more preferably a sex-branching unit, further preferably a tetrafunctional to 10-functional bifurcation unit, and particularly preferably a 5-functional to 10-functional bifurcation unit.
The n-functional branching unit refers to a branching unit in which n molecular chains appear, in other words, a structural unit having an n-functional bifurcation point (that is, a crosslinked structure).

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, and is a polyfunctional aromatic vinyl compound. More preferably, it is particularly preferably divinylbenzene.

Examples of the polyfunctional (meth) acrylate compound include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, 1,4-butanediol diacrylate, and 1,6. -Hexanediol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane dimethyloldiacrylate, trimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol triacrylate, dipentaerythritol hexa. Examples thereof include acrylate and triacrylate of tris (β-hydroxyethyl) isocyanurate.
Examples of the polyfunctional (meth) acrylamide 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 of the structural unit having a crosslinked structure is not particularly limited, but is preferably 8 to 100, and more preferably 8 to 70.

The content of the structural unit having a crosslinked structure in the addition polymerization type resin is preferably 0.5% by mass to 30% by mass, and 1% by mass to 20% by mass, based on the total mass of the addition polymerization type resin. More preferably.

[Other building blocks]
The addition polymerization type resin may further contain other structural units. As the other structural units, structural units other than the above-mentioned structural units can be contained without particular limitation, and examples thereof include structural units formed of an acrylamide compound, a vinyl ether compound, and the like.
Examples of acrylamide compounds include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-butyl (meth) acrylamide, and N, N'-dimethyl. Examples thereof include (meth) acrylamide, N, N'-diethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-hydroxypropyl (meth) acrylamide, N-hydroxybutyl (meth) acrylamide and the like.
Examples of the vinyl ether compound include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, tert-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether and 4-methylcyclohexyl. Methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, tetrahydroflu Frill vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexylmethylvinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloroethoxyethyl vinyl ether, Examples thereof include phenylethyl vinyl ether and phenoxypolyethylene glycol vinyl ether.

The content of the other structural units in the addition polymerization type resin is preferably 5% by mass to 50% by mass, more preferably 10% by mass to 30% by mass, based on the total mass of the addition polymerization type resin. preferable.

The method for producing the addition polymerization type resin is not particularly limited, and the addition polymerization type resin can be produced by a known method.
For example, a styrene compound, an acrylonitrile compound, an ethylenically unsaturated compound having a dispersible group, an N-vinyl heterocyclic compound as required, and a compound used for forming a structural unit having the ethylenically unsaturated group. Selected from the group consisting of the compound used for forming the structural unit having an acid group, the compound used for forming the structural unit having a hydrophobic group, and the compound used for forming the other structural unit. It is obtained by polymerizing at least one compound by a known method.

The polymer particles having a polymerizable group (also simply referred to as “polymer particles”) include thermoplastic polymer particles, heat-reactive polymer particles, polymer particles having a polymerizable group, and microcapsules containing a hydrophobic compound. It is preferably selected from the group consisting of microgels (crosslinked polymer particles). 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 print 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 Disclosure No. 1 of January 1992. The thermoplastic polymer particles described in 33303, JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, JP-A-9-171250, and European Patent No. 931647 are preferable.
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 polymethylmethacrylate 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.) that carry out a radical polymerization reaction, addition reaction Isocyanato group or a block thereof, an epoxy group, a vinyloxy group, 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 Preferred examples thereof include a hydroxy group or an amino group as a reaction partner, an acid anhydride for carrying out a ring-opening addition reaction, and an amino group or a hydroxy group as a reaction partner.

As the microcapsules, for example, as described in JP-A-2001-277740 and JP-A-2001-277742, at least a part of the constituent components of the image recording layer is encapsulated in the microcapsules. The constituent 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 multivalent phenol compound, a compound having a plurality of benzene rings having a phenolic hydroxy group is preferable.
As the compound having the above-mentioned 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. 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 include 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.
As an example of the pendant cyano group,-[CH ₂ CH (C≡N)-] or-[CH ₂ C (CH ₃ ) (C≡N)-] is preferably mentioned.
In addition, the constituent unit having the pendant cyano group can be easily derived from an ethylene-based unsaturated monomer such as acrylonitrile or methacrylonitrile, or from 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 fillability, 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.
Among them, a polyalkylene oxide structure is preferable, and a polyethylene oxide structure, a polypropylene oxide structure, or a polyethylene / propylene oxide structure is more preferable, from the viewpoints of fillability, printing resistance, and on-machine developability.
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 print resistance, fillability 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 print 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 into the resin A 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 printing resistance. , 30% by mass to 60% by mass is particularly preferable.

Further, the polymer particles preferably contain polymer particles having a group represented by the above formula Z from the viewpoints of fillability, print resistance, 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) - It is preferably R ^WA- O- or -OC (= O) -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 alcoholylenes 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 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 particles having a group represented by the above formula Z are more preferably divalent groups in which W has a hydrophilic structure from the viewpoints of fillability, print resistance and on-machine developability. It is more preferable that 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, it is more preferable that the polymer particles contain polymer particles having a polymerizable group on the particle surface from the viewpoint of fillability, print resistance and on-machine developability.
Further, the polymer particles preferably contain polymer particles having a hydrophilic group and a polymerizable group from the viewpoint of printing resistance.
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.

In addition, the polymer particles are made of a resin having a urea bond from the viewpoints of printing resistance, fleshing property, characteristic fleshing property, UV plate skipping suppressing property, on-machine development property, and developing residue suppressing property during on-machine development. It is preferable to include a resin having a structure obtained by at least reacting an isocyanate compound represented by the following formula (Iso) with water, and an isocyanate compound represented by the following formula (Iso) and water. It is particularly preferable to contain a resin having a structure obtained by at least reacting with and having a polyethylene oxide structure and a polypropylene oxide structure as the polyoxyalkylene structure. Further, the particles containing the resin having a 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 Reacts to form urea bonds and dimers are formed. 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 or the amine compound 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 polymer 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 photograph, 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 one type of polymer particles alone, or may contain two or more types of polymer particles.
The content of the polymer particles in the image recording layer is 5% by mass to 90% by mass with respect to the total mass of the image recording layer from the viewpoint of fillability, printing resistance, and on-machine developability. It is preferably 10% by mass to 90% by mass, more preferably 20% by mass to 90% by mass, and particularly preferably 50% by mass to 90% by mass.
Further, the content of the polymer particles in the image recording layer is based on the total mass of the components having a molecular weight of 2,500 or more in the image recording layer from the viewpoints of fillability, printing resistance and on-machine developability. , 20% by mass to 100% by mass, more preferably 35% by mass to 100% by mass, further preferably 50% by mass to 100% by mass, and 80% by mass to 100% by mass. Especially preferable.

The image recording layer may contain a binder polymer as a polymer having a polymerizable group, but it is preferable not to contain the binder polymer from the viewpoint of fillability, print resistance, and on-machine developability.
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 a machine-developed planographic 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 and 10 or less functional as a nucleus and being bonded to the nucleus by a sulfide bond, and the polymer chain having a polymerizable group Examples thereof include molecular compounds (hereinafter, also referred to as star-shaped polymer compounds). As the star-shaped polymer compound, for example, the compound described in JP2012-148555 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 or an epoxy group is preferable, and a (meth) acrylic group, a vinyl group or a styryl group is polymerizable. From the viewpoint, it is more preferable, 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 preferably has a weight average molecular weight (Mw) of 2,000 or more, more preferably 5,000 or more, and is 10,000 to 300,000 as a polystyrene-equivalent value 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 fillability, print resistance, and on-machine developability, the binder polymer is not contained or the binder polymer is not contained. The content of the binder polymer 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 It is more preferably 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 the total mass of the image recording layer. It is more preferably more than 0% by mass and 5% by mass or less, and the binder polymer is not contained, or the content of the binder polymer is 0 mass with respect to the total mass of the image recording layer. It is particularly preferable that it exceeds% and 2% by mass or less, and it is most preferable that the binder polymer is not contained.

-Polymer without polymerizable group-
The image recording layer may contain a polymer having no polymerizable group.
The polymer having no polymerizable group may be polymer particles or a binder polymer.
A preferred embodiment of the polymer having no polymerizable group is the same as that of the polymer in the polymer having a polymerizable group, except that the polymer does not have a polymerizable group.
The polymer having no polymerizable group can be contained in the image recording layer in an arbitrary amount, but from the viewpoint of fillability, print resistance, and on-machine developability, the polymer can be contained. The content of the polymer that does not contain a polymer or does not have a polymerizable group is preferably more than 0% by mass and 40% by mass or less with respect to the total mass of the image recording layer. The content of the polymer that does not contain the polymerizable group or that does not have the polymerizable group is more than 0% by mass and 30% by mass or less with respect to the total mass of the image recording layer. It is more preferable that the polymer does not contain the polymer having no polymerizable group, or the content of the polymer having no polymerizable group is 0% by mass based on the total mass of the image recording layer. It is more preferably more than 10% by mass, and the content of the polymer which does not contain the polymer having no polymerizable group or which does not have the polymerizable group is based on the total mass of the image recording layer. It is particularly preferable that the content is more than 0% by mass and 5% by mass or less, and it is most preferable that the polymer having no polymerizable group is not contained.

The polymer having no polymerizable group preferably has a glass transition temperature (Tg) of 50 ° C. or higher, more preferably 70 ° C. or higher, from the viewpoint of suppressing a decrease in on-machine developability over time. It is preferably 80 ° C. or higher, more preferably 90 ° C. or higher.
The upper limit of the glass transition temperature of the binder polymer is preferably 200 ° C., more preferably 120 ° C. or lower, from the viewpoint of easy water penetration into the image recording layer.

As the binder polymer having the above glass transition temperature, polyvinyl acetal is preferable from the viewpoint of further suppressing the decrease in on-machine developability with time.

Polyvinyl acetal is a resin obtained by acetalizing the hydroxy group of polyvinyl alcohol with an aldehyde.
In particular, polyvinyl butyral in which the hydroxy group of polyvinyl alcohol is acetalized (that is, butyralized) with butyraldehyde is preferable.
The polyvinyl acetal preferably contains a structural unit represented by the following (a) by acetalizing the hydroxy group of polyvinyl alcohol with an aldehyde.

Here, R represents a residue of the aldehyde used for acetalization.
Examples of R include a hydrogen atom, an alkyl group and the like, as well as an ethylenically unsaturated group described later.

The content of the structural unit represented by (a) above (also referred to as the amount of ethylene groups in the main chain contained in the structural unit represented by (a) above, and also referred to as the degree of acetalization) is polyvinyl acetal. 50 mol% to 90 mol% is preferable, 55 mol% to 85 mol% is more preferable, and 55 mol% to 80 mol% is further more preferable with respect to the total structural unit (total ethylene group amount of the main chain).
The degree of acetalization is the amount of ethylene groups to which acetal groups are bonded (the amount of ethylene groups in the main chain included in the structural unit represented by (a) above) divided by the total amount of ethylene groups in the main chain. It is a value showing the molar fraction obtained by the above as a percentage.
The same applies to the content of each structural unit of polyvinyl acetal, which will be described later.

The polyvinyl acetal preferably further contains a structural unit having a hydroxy group from the viewpoint of on-machine developability and the like. That is, the polyvinyl acetal preferably contains a structural unit derived from vinyl alcohol.
Examples of the structural unit having a hydroxy group include the structural unit represented by the following (b).

The content (also referred to as the amount of hydroxyl groups) of the structural unit represented by (b) above is preferably 5 mol% to 50 mol%, preferably 10 mol%, based on all the structural units of polyvinyl acetal from the viewpoint of on-machine developability. It is more preferably from 40 mol%, still more preferably from 20 mol% to 40 mol%.

The polyvinyl acetal may further contain other structural units.
Examples of the other structural unit include a structural unit having an acetyl group, specifically, a structural unit represented by the following (c).

The content (also referred to as the amount of acetyl group) of the structural unit represented by the above (c) is preferably 0.5 mol% to 10 mol%, preferably 0.5 mol% to 8 mol%, based on all the structural units of polyvinyl acetal. Is more preferable, and 1 mol% to 3 mol% is further preferable.

Here, the degree of acetalization, the amount of acrylate groups, the amount of hydroxyl groups, and the amount of acetyl groups can be determined as follows.
That is, the mol content is calculated from the proton peak area ratios of the methyl or methylene moiety of acetal, the methyl moiety of the acrylate group, and the methyl moiety of the hydroxyl group and the acetyl group by ¹ H NMR measurement.

The weight average molecular weight of the polyvinyl acetal is preferably 18,000 to 150,000.

Solubility parameter of the polyvinyl acetal (also referred to as SP value) ^is preferably from 17.5MPa ^1/2 ~ 20.0MPa ^1/2, to be 18.0MPa ^1/2 ~ 19.5MPa 1/2 More preferable.
Here, the “solubility parameter (unit: (MPa) ^1/2 )” in the present disclosure uses the Hansen solubility parameter.
The Hansen solubility parameter is a three-dimensional space obtained by dividing the solubility parameter introduced by Hildebrand into three components, a dispersion term δd, a polarity term δp, and a hydrogen bond term δh. In the present disclosure, the solubility parameter (hereinafter, also referred to as SP value) is represented by δ (unit: (MPa) ^1/2 ), and a value calculated using the following formula is used.
δ (MPa) ^1/2 = (δd ² + δp ² + δh ² ) ^1/2
The dispersion term δd, the polarity term δp, and the hydrogen bond term δh are more sought after by Hansen and his successors, and are described in detail in the Polymer Handbook (fourth edition), VII-698-711. .. The details of the value of the solubility parameter of Hansen are described in the document "Hansen Solubility Parameters; A Users Handbook (CRC Press, 2007)" by Charles M. Hansen.
In the present disclosure, the Hansen solubility parameter in the partial structure of the compound can be a value estimated from the chemical structure by using the computer software "Hansen Solubility Parameters in Practice (HSPiP ver.4.1.07)".
Further, in the present disclosure, when the compound is an addition polymerization type, polycondensation type or the like polymer, the SP value for each monomer unit is shown as the total amount multiplied by the molar fraction, and the compound has no monomer unit. If it is a molecular compound, it is the SP value of the entire compound.
In the present disclosure, the SP value of the polymer may be calculated from the molecular structure of the polymer by the Hoy method described in the Polymer Handbook (fourth edition).

Specific examples [P-3] of the above-mentioned polyvinyl acetal are listed below, but the polyvinyl acetal used in the present disclosure is not limited thereto.
In the structure below, "l" is 50 mol% to 90 mol%, "m" is 0.5 mol% to 10 mass%, "n" is 5 mol% to 50 mol%, and "o" is 1 mol% to 1 mol%. It is 15 mol%.

As the polyvinyl acetal, a commercially available product can be used.
As a commercial product of polyvinyl acetal, Sekisui Chemical Co., Ltd.'s Eslek series (specifically, Eslek BX-L, BX-1, BX-5, BL-7Z, BM-1, BM-5, BH -6, BH-3, etc.).

The image recording layer in the present disclosure preferably contains a resin having a fluorine atom, and more preferably contains a fluoroaliphatic group-containing copolymer.
By using a resin having a fluorine atom, particularly a fluoroaliphatic group-containing copolymer, it is possible to suppress surface quality abnormalities due to foaming during formation of the image recording layer, improve the coating surface shape, and further form the image recording layer. The inking property of the ink in the image recording layer can be improved.
In addition, the image recording layer containing the fluoroaliphatic group-containing copolymer has high gradation, for example, high sensitivity to laser light, good fog resistance due to scattered light, reflected light, etc., and excellent printing resistance. An excellent lithographic printing plate can be obtained.

The fluoroaliphatic group-containing copolymer preferably has a structural unit formed of a compound represented by either the following formula (F1) or the following formula (F2).

In formulas (F1) and (F2), R ^F1 independently represents a hydrogen atom or a methyl group, and X independently represents an oxygen atom, a sulfur atom, or -N ( ^RF2 )-. m represents an integer of 1 ~ 6, n represents an integer of 1 ~ 10, l represents an integer of 0 ~ ^{10, R F2} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

The alkyl group having 1 to 4 carbon atoms represented by ^RF2 in the formulas (F1) and (F2) is preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group, preferably a hydrogen atom or a methyl group. Is more preferable.
It is preferable that X in the formulas (F1) and (F2) is an oxygen atom.
The m in the formula (F1) is preferably 1 or 2, and more preferably 2.
N in the formula (F1) is preferably 2, 4, 6, 8, or 10, and more preferably 4 or 6.
The l in the formula (F1) is preferably 0.

Specific examples of the monomer having a fluorine atom used in the resin having a fluorine atom are shown below, but the present invention is not limited thereto.

The fluoroaliphatic group-containing copolymer is composed of poly (oxyalkylene) acrylate and poly (oxyalkylene) in addition to the structural unit formed from the compound represented by any of the above formulas (F1) and (F2). It is preferable to further have a structural unit formed by at least one compound selected from the group consisting of methacrylates.

The polyoxyalkylene group in the poly (oxyalkylene) acrylate and the poly (oxyalkylene) methacrylate can be represented ^by- (OR ^F3 ) _x- , ^RF3 represents an alkyl group, and x is an integer of 2 or more. Represent. The ^RF3 is preferably a linear or branched alkylene group having 2 to 4 carbon atoms. Examples of the linear or branched alkylene group having a carbon number of _{2 ~ 4, -CH 2 CH 2} -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, or -CH (CH ₃ ) CH (CH ₃ )-preferably. x is preferably an integer of 2 to 100.
Among the polyoxyalkylene groups, x "OR ^F3 " may be the same or different. That is, the polyoxyalkylene group may be one in which two or more kinds of "OR ^F3 " are regularly or irregularly bonded. For example, the polyoxyalkylene group may be one in which linear or branched oxypropylene units and oxyethylene units are regularly or irregularly bonded. More specifically, the polyoxyalkylene group may be a combination of a linear or branched block of oxypropylene units and a block of oxyethylene units.
The polyoxyalkylene group may contain one or more linking groups (for example, -CONH-Ph-NHCO-, -S-, etc., where Ph represents a phenylene group). ..
The molecular weight of the polyoxyalkylene group is preferably 250 to 3,000.

As the poly (oxyalkylene) acrylate and the poly (oxyalkylene) methacrylate, a commercially available product or a synthetic product may be used.
The poly (oxyalkylene) acrylate and the poly (oxyalkylene) methacrylate react, for example, with a hydroxypoly (oxyalkylene) compound with acrylic acid, methacrylic acid, acrylic chloride, methacrylic chloride, anhydrous acrylic acid, or the like by a known method. It can be synthesized by letting it.
As the hydroxypoly (oxyalkylene) compound, a commercially available product may be used, for example, ADEKA (registered trademark) Pluronic manufactured by ADEKA Corporation, ADEKA polyether manufactured by ADEKA Corporation, and Union Carbide Corporation. Examples thereof include Carbowax (registered trademark), Triton manufactured by Dow Chemical Corporation, and PEG manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
As the poly (oxyalkylene) acrylate and the poly (oxyalkylene) methacrylate, poly (oxyalkylene) diacrylate or the like synthesized by a known method may be used.

-Color former-
The image recording layer preferably contains a color former, and more preferably contains an acid color former. Moreover, it is preferable that the color former contains a leuco compound.
The "color former" used in the present disclosure means a compound having the property of changing the color of the image recording layer by developing or decoloring the color by a stimulus such as light or acid, and the "acid color former" is used. It means a compound having a property of developing or decoloring and changing the color of an image recording layer by heating in a state of receiving an electron-accepting compound (for example, a proton such as an acid). 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) Ethylene-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-3) -Ftalides such as 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-chlorofluorine, 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-dinaphthopylane, 3-ethyl-spiro-dinaftopylan, 3-phenyl-spiro-dinaftopylan, 3-benzyl-spiro-dinaftpyran , 3-Methyl-naphtho- (3-methoxybenzo) spiropyrane, 3-propyl-spiro-dibenzopyran-3,6-bis (dimethylamino) fluorene-9-spiryl-3'-(6'-dimethylamino) phthalide , 3,6-Bis (diethylamino) fluorene-9-spiro-3'-(6'-dimethylamino) phthalides and other phthalides,

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 color former used in the present disclosure is preferably 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. ..
From the viewpoint of visibility, the hue of the dye after color development is preferably green, blue or black.

Further, the acid coloring agent is preferably a leuco dye from the viewpoint of color developing property 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.
The leuco dye is preferably a leuco dye having a phthalide structure or a fluorine structure from the viewpoint of color development and visibility of the exposed portion.
Further, the leuco dye having the phthalide structure or the 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 is absent and Y ₂ is N, then X ₄ is absent, Ra ₁ represents a hydrogen atom, an alkyl group or an alkoxy group, and Rb ₁ to Rb ₄ are independent alkyl groups. Or represents an 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 dialkylamino groups 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 diarylamino group, an alkoxy group, or an aryloxy group is more preferable, a monoalkyl monoarylamino group or a diarylamino group is further preferable, and a monoalkyl monoarylamino group is particularly preferable. ..
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 preferably hydrogen atoms or alkyl groups independently 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 fluorene 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. The compound represented by any of Le-6) is more preferable, and the compound represented by the following formula (Le-5) is further preferable.

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 an alkyl group or an aryl group, respectively.

ERG, X ₁ to X ₄ , Y ₁ , Y ₂ , Ra ₁ and Rb ₁ to Rb ₄ in the formulas (Le-4) to (Le-6) are the formulas (Le-1) to the formulas (Le-1) to Rb ₄ , respectively. 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) from the viewpoint of color development and visibility of the exposed portion. A compound represented by any of Le-9) is more preferable, and a compound represented by the following formula (Le-8) is particularly preferable.

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 are independent hydrogen atoms and alkyl, respectively. Represents a group or an alkoxy group, Rb ₁ to Rb ₄ independently represent 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 preferably alkyl groups or alkoxy groups independently from the viewpoint of color development and visibility of the exposed portion, respectively, 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 substituted with a hydrogen atom, an alkyl group, or an alkoxy group from the viewpoint of color development and visibility of the exposed portion. It is preferably a group, more preferably an alkyl group, and particularly preferably a methyl group.
Rc ₁ and Rc ₂ in the formula (Le-8) are preferably phenyl groups or alkylphenyl groups, and are preferably phenyl groups, independently from the viewpoint of color development and visibility of the exposed portion. Is more preferable.
Further, in the formula (Le-8), it is preferable that X ₁ to X ₄ are hydrogen atoms and Y ₁ and Y ₂ are C from the viewpoint of color development and visibility of the exposed portion.
Further, in the formula (Le-8), from the viewpoint of color development and visibility of the exposed portion, it is preferable that Rb ₁ and Rb ₂ are independently alkyl groups or aryl groups substituted with an alkoxy 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, diarylamino groups, hydroxy groups, alkoxy groups, allyloxy groups and acyl groups. 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. In addition, Me represents a methyl group.

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 Kasei Kogyo 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 color formers may be used alone or in combination of two or more kinds of components.
The content of the 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.

Only one type of chain transfer agent may be added, or two or more types may be used in combination.
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.

-Low molecular weight hydrophilic compound-
The image recording layer may contain a low molecular weight hydrophilic compound in order to improve on-machine developability while suppressing a decrease in printing resistance. The low molecular weight hydrophilic compound is preferably a compound having a molecular weight of less than 1,000, more preferably a compound having a molecular weight of less than 800, and further preferably a compound having a molecular weight of less than 500.
Examples of the low molecular weight hydrophilic compound include, as water-soluble organic compounds, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol, ethers or ester derivatives thereof, and glycerin. Polyols such as pentaerythritol and tris (2-hydroxyethyl) isocyanurate, organic amines such as triethanolamine, diethanolamine and monoethanolamine and salts thereof, organic sulfates such as alkyl sulfonic acid, toluene sulfonic acid and benzene sulfonic acid. Acids and salts thereof, organic sulfamic acids such as alkylsulfamic acid and salts thereof, organic sulfates such as alkylsulfuric acid and alkylether sulfuric acid and salts thereof, organic phosphonic acids such as phenylphosphonic acid and salts thereof, tartrate acid, oxalic acid, quench Examples thereof include organic carboxylic acids such as acids, malic acids, lactic acids, gluconic acids and amino acids, salts thereof, and betaines.

As the low molecular weight hydrophilic compound, it is preferable to contain at least one selected from polyols, organic sulfates, organic sulfonates and betaines.

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

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

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

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

The content of the low molecular weight hydrophilic compound is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 15% by mass, and 2% by mass to 10% by mass with respect to the total mass of the image recording layer. Is more preferable. Good on-machine developability and print resistance can be obtained in this range.
The low molecular weight hydrophilic compound may be used alone or in combination of two or more.

-Fat sensitive agent-
The image recording layer may contain a fat-sensing agent such as a phosphonium compound, a nitrogen-containing low molecular weight 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). Phenylphosphonio) heptane-sulfate, 1,9-bis (triphenylphosphonio) nonane-naphthalen-2,7-disulfonate and the like can be mentioned.

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

The ammonium group-containing polymer may have an ammonium group in its structure, and a polymer containing 5 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 reduced 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-methacloyloxypropyl 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, as other components, a surfactant, a polymerization inhibitor, a higher fatty acid derivative, a plasticizer, inorganic particles, an inorganic layered compound and the like. Specifically, the description in paragraphs 0114 to 0159 of JP-A-2008-284817 can be referred to.

-Formation of image recording layer-
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 necessary components in a known solvent, for example, as described in paragraphs 0142 to 0143 of Japanese Patent Application Laid-Open No. 2008-195018. 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 and ethyl lactate. 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.

<Aluminum support>
The aluminum support in the lithographic printing plate original plate according to the present disclosure can be appropriately selected from known aluminum supports for lithographic printing plate original plates and used. Hereinafter, the aluminum support is also simply referred to as a "support".
As the aluminum support, an aluminum support having a hydrophilic surface (hereinafter, also referred to as “hydrophilic aluminum support”) is preferable.
The aluminum support in the lithographic printing plate original plate 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. Is more preferable, 90 ° or less is more preferable, 80 ° or less is further preferable, 50 ° or less is further preferable, 30 ° or less is particularly preferable, and 20 ° or less is preferable. 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 lithographic 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 Chemistry 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 anodized film of aluminum 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 anodized film of aluminum arranged on the aluminum plate, and the anodized 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. 1 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 anodized film 20a of aluminum (hereinafter, also simply referred to as “anodized film 20a”) are laminated in this order. The anodized 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 anodized film and an image recording layer on an aluminum plate in this order.

-Anodized film-
Hereinafter, preferred embodiments of the anodized coating 20a will be described.
The anodized film 20a is a film formed on the surface of the aluminum plate 18 by anodizing treatment, and this film is extremely fine micropores 22a which are substantially perpendicular to the film surface and are uniformly distributed among individuals. Has. The micropores 22a extend from the surface of the anodized film 20a on the image recording layer side (the surface of the anodized 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 anodized film 20a on the surface of the anodized 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 resistance 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 micropores existing in the range of is measured at 50 points and calculated as an arithmetic average 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 anodized 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 ^* brightness L ^* in the color system of the surface of the aluminum support 12a on the image recording layer side (the surface of the anodized 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-Light 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. 2 is a schematic cross-sectional view of the aluminum support 12a according to an embodiment different from that shown in FIG.
In FIG. 2, 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 anodized film 20b communicate with the large-diameter hole portion 24 extending from the surface of the anodized film to a position at a depth of 10 nm to 1000 nm (depth D: see FIG. 2) 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 anodized film 20b is the same as the average diameter of the micropores 22a in the above-mentioned anodized film 20a on the surface of the anodized 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 anodized film. That is, the large-diameter hole portion 24 is a hole portion extending from the surface of the anodized 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 anodized 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. 2, 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. Of these, 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 hole portion 26 is such that the surface of the anodized film 20a is observed with N = 4 images 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 FE-SEM to obtain the average diameter of the small-diameter holes.
When 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 1,500 nm.
The depth is an average value obtained by taking a photograph (50,000 times) of the cross section of the anodized 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 (approximately cylindrical) shape 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: A step of roughening an aluminum plate-Anodization treatment step: A step of anodizing an aluminum plate that has been roughened-Pore wide treatment step: Anodizer obtained in an anodization 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 anodic oxide 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 performed 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, it is preferable to carry out the treatments shown in the A mode or the B mode in the order shown below.

~ 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 A aspect or (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.
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 is an electrochemical rough surface using ordinary direct current or alternating current. 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. In addition, 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. 3 is a graph showing an example of an alternating waveform current waveform diagram used in the electrochemical roughening process.
In FIG. 3, 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 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. 4 can be used for electrochemical roughening using alternating current.
FIG. 4 is a side view showing an example of a radial cell in an electrochemical roughening treatment using alternating current.
In FIG. 4, 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 electrolytic solution supply port, 55 is an electrolytic solution, 56 is a slit, and 57 is an electrolytic solution passage. 58 is an auxiliary anode, 60 is an auxiliary anode tank, and W is an aluminum plate. In FIG. 4, 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 alkali 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, and 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 5A / dm ² to 60A / dm ² ), voltage 1V to 100V (preferably 5V to 50V), electrolysis time 1 to 100 seconds (preferably 5 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 micropores existing in the anodizing film formed by the above-mentioned anodizing treatment step.
The pore-wide treatment can be carried out 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 method of contact is not particularly limited, and examples thereof include a dipping method and a spraying method.

<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. 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 low molecular weight 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.
Adsorbent groups that can be adsorbed on the surface of the support include phenolic hydroxy groups, carboxy groups, -PO ₃ H ₂ , -OPO ₃ H ₂ , -CONHSO _2- , -SO ₂ NHSO _2- , -COCH ₂ COCH ₃ Is preferable. As the hydrophilic group, a sulfo group or a salt thereof, or a salt of a carboxy group is preferable. As the crosslinkable group, an acrylic group, a methacrylic group, an acrylamide group, a methacrylamide group, an allyl group and the like are preferable.
The polymer may have a crosslinkable group introduced by salt formation of the polar substituent of the polymer, a substituent having a pair charge with the polar substituent and a compound having an ethylenically unsaturated bond, and the above. A monomer other than the above, preferably a hydrophilic monomer, may be further copolymerized.

Specifically, a silane coupling agent having an addition-polymerizable ethylenic double bond reactive group described in JP-A No. 10-282679, and an ethylenic 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 examples thereof include polymer polymers having an adsorptive group, a hydrophilic group and a crosslinkable group that can be adsorbed on the surface of the support described in JP-A-2005-125794 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 in 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.
Preferred examples of the hydrophilic compound include phosphonic acids having an amino group such as carboxymethyl cellulose and dextrin, organic phosphonic acid, organic phosphoric acid, organic phosphinic acid, amino acids, and hydrochloride of amine 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 (Ethyliminodiacetic acid or a salt thereof, etc.) is preferably mentioned.

The hydrophilic compound preferably contains hydroxycarboxylic acid or a salt thereof from the viewpoint of suppressing scratches and stains.
Further, the hydrophilic compound, preferably 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 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 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 layer on the image recording layer side (for example, an image recording layer or an undercoat layer) in contact with the 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 stain suppressing 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 formula (HC)
In formula (HC), R ^HC represents a mhc + nhc valent organic group, M ^HC independently represents a hydrogen atom, an alkali metal or onium, and mhc and nhc each independently represent an integer of 1 or more, n. If is 2 or more, the ^MHC may be the same or different.

In the formula ^(HC), as the organic group for mhc + NHC value represented by ^{R HC,} it includes 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 alcampentile 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 hydroxy group and the carboxy 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 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, 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, trill group, xylyl 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.
Specific examples of the hydroxycarboxylic acid constituting the hydroxycarboxylic acid or the salt of the hydroxycarboxylic acid include gluconic acid, glycolic acid, lactic acid, tartron acid, and 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, floret acid, kumalic acid, umbelic 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 .

<Protective layer>
The lithographic printing plate original plate according to the present disclosure may have a protective layer (sometimes referred to as an overcoat layer) on the image recording layer on the side opposite to the side on which the aluminum support is provided. The protective layer may have a function of suppressing an image formation inhibition reaction by blocking oxygen, a function of preventing the occurrence of scratches on the image recording layer, and a function of preventing ablation during high-intensity laser exposure.

Protective layers with such properties are described, for example, in US Pat. Nos. 3,458,311 and JP-A-55-49729. As the oxygen low-permeability polymer used for the protective layer, either a water-soluble polymer or a water-insoluble polymer can be appropriately selected and used, and if necessary, two or more kinds may be mixed and used. it 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 , potassium 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 this tendency 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 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, the total amount of the inorganic layered compounds is preferably the above content. Oxygen blocking property is improved in the above range, and good sensitivity can be obtained. In addition, it is possible to prevent deterioration of 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. Further, the protective layer may contain the oil-sensitive agent described in the image recording 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.

(Planographic printing plate manufacturing method and lithographic printing method)
A lithographic printing plate can be produced by subjecting the original plate of the lithographic printing plate according to the present disclosure to an image and developing the plate.
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 produce 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 lithographic printing plate manufacturing method 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 at the time of on-machine development, and a part remains on the surface of the image part or permeates into the inside of the image part 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, a 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 within 20 microseconds, 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 as described above. 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 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 ( 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. A 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 in which the protective layer is removed by a pre-washing step, then alkaline development is performed, the alkali is washed and removed in a post-washing step, a gum solution treatment is performed, and the drying step is performed. 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 solution 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 can 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 portion. It is preferable to use very strong conditions for heating after development, 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 addition, in this Example, "%" and "part" mean "mass%" and "part by mass", respectively, unless otherwise specified. In the polymer compound, the molecular weight is the weight average molecular weight (Mw), and the ratio of the constituent repeating units is a molar percentage, except for those specified specifically. The weight average molecular weight (Mw) is a value measured as a polystyrene-equivalent value by a gel permeation chromatography (GPC) method. Further, the average particle size means a volume average particle size unless otherwise specified.

(Examples 1 to 28)
<Preparation of support>
<< Surface Treatment A >>
[Support with large-diameter holes and small-diameter holes]
(Aa) Alkaline Etching Treatment An aqueous solution of caustic soda having a caustic soda (sodium hydroxide) 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. by a spray tube to perform an etching treatment. .. Then, it was washed with water by spraying. The amount of aluminum dissolved on the surface to be subjected to the electrochemical roughening treatment later was 1.0 g / m ² .

(Ab) Desmat treatment in an acidic aqueous solution (first desmat treatment)
Next, a desmat treatment was performed in an acidic aqueous solution. As the acidic aqueous solution used for the desmat treatment, an aqueous solution of sulfuric acid of 150 g / L was used. The liquid temperature was 30 ° C. The desmat solution was sprayed and treated with desmat for 3 seconds. Then, it was washed with water.

(Ac) Electrochemical roughening treatment in hydrochloric acid aqueous solution Next, electrolysis using an electrolytic solution having a hydrochloric acid concentration of 14 g / L, an aluminum ion concentration of 13 g / L, and a sulfuric acid concentration of 3 g / L was used. Roughening treatment was performed. The temperature of the electrolytic solution was 30 ° C. The aluminum ion concentration was adjusted by adding aluminum chloride. The AC current waveform is a sinusoidal wave with symmetrical positive and negative waveforms, the frequency is 50 Hz, the anode reaction time and cathode reaction time in one AC current cycle are 1: 1, and the current density is the peak current value of the AC current waveform. It was 75 A / dm ² . The total amount of electricity stored in the anodic reaction of the aluminum plate was 450 C / dm ² , and the electrolysis treatment was carried out in 4 steps with an energization interval of 125 C / dm ^{2 for} 4 seconds. A carbon electrode was used as the counter electrode of the aluminum plate. Then, it was washed with water.

(Ad) Alkaline etching treatment The aluminum plate after the electrochemical roughening treatment is etched by spraying 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 with a spray tube at a temperature of 45 ° C. Processing was performed. The dissolved amount of aluminum on the surface subjected to the electrochemical roughening treatment was 0.2 g / m ² . Then, it was washed with water.

(Ae) Desmat treatment in an acidic aqueous solution Next, a desmat treatment in an acidic aqueous solution was performed. As the acidic aqueous solution used for the desmat treatment, a waste liquid (aluminum ion 5.0 g / L dissolved in a sulfuric acid 170 g / L aqueous solution) generated in the anodizing treatment step was used. The liquid temperature was 30 ° C. The desmat solution was sprayed on a spray to perform a desmat treatment for 3 seconds.

(Af) 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 was performed under the conditions shown in Table 1 to form an anodized film having a predetermined film thickness.

(Ag) Pore Wide Treatment The anodized aluminum plate is immersed in a caustic soda aqueous solution having a temperature of 35 ° C., a caustic soda concentration of 5% by mass, and an aluminum ion concentration of 0.5% by mass under the conditions shown in Table 1 for pore wide treatment. Was done. Then, it was washed with water by spraying.

(Ah) 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 was performed under the conditions shown in Table 1 to form an anodized film having a predetermined film thickness.
From the above surface treatment A, the support S1 of the example was obtained.

The average diameter (nm) on the surface of the anodic oxide film of the large-diameter pores in the anodic oxide film having micropores after the second anodic oxidation treatment step obtained above, and the average diameter (nm) at the communication position of the small-diameter pores. , Depth (nm) of large and small holes, pit density (micropore density, unit; piece / μm ² ), and thickness of anodic oxide film from the bottom of the small holes to the surface of the aluminum plate. (Nm) are summarized in Table 2.
The average diameter of the micropores (average diameter of the large-diameter hole and the small-diameter hole) was obtained by observing the surface of the large-diameter hole and the surface of the small-diameter hole with N = 4 sheets at a magnification of 150,000 times. The diameters of the micropores (large-diameter hole portion and small-diameter hole portion) existing in the range of 400 nm × 600 nm were measured and averaged in the four images obtained. If the depth of the large-diameter hole is deep and it is difficult to measure the diameter of the small-diameter hole, or if the enlarged-diameter hole in the small-diameter hole is to be measured, the upper part of the anodic oxide film is cut, and then Various diameters were calculated.
For the depth of the micropores (depth of the large-diameter hole and the small-diameter hole), observe the cross section of the support (anodic oxide film) with FE-SEM (observation of the depth of the large-diameter hole: 150,000 times, small diameter). (Observation of hole depth: 50,000 times), in the obtained image, the depths of 25 arbitrary micropores were measured and averaged.
In Table 1, the amount of film (AD) in the first anodizing treatment column and the amount of film (AD) in the second anodizing treatment column represent the amount of film obtained in each treatment. The electrolytic solution used is an aqueous solution containing the components in Table 1.

<Formation of undercoat layer>
An undercoat layer coating solution (1) having the following composition was applied onto the support so that the dry coating amount was 23 mg / m ² to form an undercoat layer.

<Undercoat layer coating liquid (1)>
-Polymer (P-1) [structure below]: 0.18 parts-Hydroxyethyliminodiacetic acid: 0.10 parts-Water: 61.4 parts

<Formation of image recording layer>
An image recording layer coating solution having the following composition was bar-coated on the undercoat layer and dried in an oven at 120 ° C. for 40 seconds to form an image recording layer having a dry coating amount of 1.0 g / m ² .
The image recording layer coating liquid was prepared by mixing the compounds with the compositions shown in Table 3 or Table 4.
The surfactant used was the fluorine-based surfactant (1) described later, the low molecular weight hydrophilic compound used A-1 described later, and the binder polymer used B-1 described later.

Details of each compound shown in Tables 3 and 4 are shown below.

Monomer M-1: Urethane acrylate containing the following compound (molecular weight less than 2,500), U-15HA (manufactured by Shin Nakamura Chemical Industry Co., Ltd.)
M-2: The following compounds (molecular weight less than 2,500), UA-510H (manufactured by Kyoeisha Chemical Co., Ltd.)
M-3: Tris (acryloyloxyethyl) isocyanurate (molecular weight less than 2,500), A-9300 (manufactured by Shin Nakamura Chemical Industry Co., Ltd.)
M-4: Dipentaerythritol hexaacrylate (molecular weight less than 2,500), DPHA (manufactured by Shin Nakamura Chemical Industry Co., Ltd.)

-Electron-accepting polymerization initiator I-1: The following compound, LUMO = -3.02 eV, counter anion δd = 20.9, δp = 20.7, δh / δp = 48%
I-2: The following compounds, LUMO = -2.81eV, Note, TsO ^- represents a tosylate anion.
I-3: The following compound, LUMO = -3.02 eV

-Electron-donated polymerization initiator D-1: The following compound, HOMO = -6.05eV, and Bu represents an n-butyl group.
D-2: The following compound, HOMO = -5.91 eV

-Infrared absorber IR-1: The following compounds, δd = 20.9, δp = 20.7, δh / δp = 48% of the counter anion
IR-2: The following compounds IR-3: The following compounds

-Color former C-1: Leuco dye (acid color former) shown below
Color formers S-1, S-4, S-6 or S-11 to S-14: The same compounds as S-1, S-4, S-6 or S-11 to S-14 described above were used. ..

-Surfactant Fluorosurfactant (1): The following compound W-1

-Low molecular weight hydrophilic compound A-1: The following compounds

・ Solvent 2-butanone 1-methoxy-2-propanol

-Binder polymer B-1: Resin shown below

The preparation method of the binder polymer B-1 is shown below.
78 parts of 1-methoxy-2-propanol was added to the three-necked flask, and the temperature was adjusted to 70 ° C. under a nitrogen stream. The dropping liquid 1 shown below was added dropwise thereto over 2.5 hours, and after the completion of the dropping, the temperature was raised to 80 ° C. and the mixture was stirred for 2 hours. Further, the additive solution 1 shown below was added, the temperature was raised to 90 ° C., and the mixture was stirred for 2.5 hours.

-Dripping liquid 1-
・ Methyl methacrylate: 21.8 parts ・ Blemmer PME100 (methoxypolyethylene glycol methacrylate, manufactured by Nichiyu Co., Ltd.): 52.1 parts ・ Methacrylic acid: 14.2 parts ・ Dipentaerythritol hexakis (3-mercaptopropionic acid) ): 2.15 parts, V-601 (dimethyl 2,2-azobis (2-methylpropionate), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.): 0.38 parts, 1-methoxy-2-propanol: 50.2 copies

-Additional solution 1-
・ V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.): 0.038 parts ・ 1-methoxy-2-propanol: 4.0 parts

The above reaction solution was cooled to 25 ° C., and 136.6 parts of 1-methoxy-2-propanol, 0.238 parts of 4-OH-TEMPO, 25.88 parts of glycidyl methacrylate, and 2.957 parts of trimethylbenzylammonium bromide were added. , 90 ° C. for 18 hours. The obtained solution was cooled to room temperature and diluted with 1-methoxy-2-propanol to a solid content concentration of 23% to obtain a binder polymer B-1. The weight average molecular weight (Mw) converted into polystyrene by the gel permeation chromatography (GPC) method was 40,000.

-Polymer particles P-1: Styrene-acrylonitrile copolymer particles having an ethylenically unsaturated group having each of the following structural units (addition polymerization type resin, molecular weight of 2,500 or more)

The method for preparing the styrene-acrylonitrile copolymer particles P-1 having the ethylenically unsaturated group is shown below.

0.625 parts of styrene, 0.3125 parts of divinylbenzene, 0.5625 parts of acrylonitrile, 2.15 parts of methacrylic acid, PME-2000 (methoxypolyethylene glycol methacrylate, manufactured by Nichiyu Co., Ltd.) 1.0 in a three-necked flask. , 0.009 part of sodium lauryl sulfate and 90 parts of distilled water were added, and the mixture was stirred under a nitrogen atmosphere and heated to 70 ° C. Next, 0.062 parts of potassium persulfate and 5.0 parts of distilled water were added, and the mixture was stirred for 4 hours. Then, the temperature was raised to 90 ° C., and the mixture was stirred for 2 hours. After the above stirring was completed, the reaction solution was allowed to cool to room temperature (25 ° C., the same applies hereinafter) to obtain a dispersion of polymer particles 1. The median diameter of the polymer particles in the dispersion was 100 nm.
To 100 parts of the obtained dispersion of the polymer particles 1, 0.254 parts of sodium hydrogen carbonate was added to adjust the pH of the system to 7.5, and then the temperature was raised to 90 ° C. After that, 1.5 parts of TBAB (tetrabutylammonium bromide), 0.001 part of 4OH-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl), 4-HBAGE (4-hydroxy). Butyl acrylate glycidyl ether) 10.0 parts was added, and the mixture was stirred for 8 hours. Then, centrifugation was performed to remove low molecular weight components 4-HBAGE, TBAB, and 4-OH TEMPO. The coating liquid was added and redispersed, and the solid content was adjusted to 20% by mass to obtain the target particles P-1.

P-2: Polyurethane particles having an ethylenically unsaturated group (microgel, polycondensation resin, molecular weight of 2,500 or more)

The method for preparing the polyurethane particles (microgels) having the ethylenically unsaturated group 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>
The following oil phase components and aqueous phase components were mixed and emulsified at 12,000 rpm for 10 minutes using a homogenizer. After each clan at 45 ° C. for 4 hours, the obtained emulsion was prepared with 1,8-diazabicyclo [5.4.0] undec-7-en-octylate (U-CAT SA102, manufactured by San-Apro Co., Ltd.). 5.20 parts of a mass% aqueous solution was added, the mixture was stirred at room temperature for 30 minutes, and allowed to stand at 45 ° C. for 24 hours. The solid content concentration was adjusted to 20% by mass with distilled water to obtain an aqueous dispersion of microgel (1). When the average particle size was measured by the light scattering method, it was 0.28 μm.

-Oil phase component-
(Component 1) Ethyl acetate: 12.0 parts (Component 2) Trimethylol propane (6 mol) and xylene diisocyanate (18 mol) are added, and one-terminal methylated polyoxyethylene (1 mol, oxyethylene unit) is added thereto. Additive (50% by mass ethyl acetate solution, manufactured by Mitsui Chemicals, Inc.) to which the number of repetitions: 90) was added: 3.76 parts (component 3) Polyhydric isocyanate compound (1) (as 50% by mass ethyl acetate solution) ): 15.0 parts (Component 4) 65% by mass ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer) 11.54 parts (Component 5) Sulfate-type surfactant (Pionin A) 4-1C, 10% ethyl acetate solution of Takemoto Oil & Fat Co., Ltd .: 4.42 parts

-Aqueous phase component-
Distilled water: 46.87 parts

Polymer particles 18-22: Particles 18-22 produced by the following method

<Preparation of polymer particles 18 (particles 18)>
-Synthesis of wall material A-

In a three-necked flask, MR-200 (compound represented by formula (Iso), n = 0 to 10, manufactured by Toso Co., Ltd.) 7.5 g, PETA (pentaerythritol triacrylate, manufactured by Nippon Kayaku Co., Ltd.) , SR444), and 10 g of ethyl acetate were added, and the mixture was stirred at room temperature and then heated to 60 ° C.
Next, 0.05 g of Neostan U-600 was added to the three-necked flask, and the mixture was heated and stirred for 3 hours. Then, it cooled to room temperature, and wall material A (solid content 50% by mass) was obtained.

-Synthesis of wall material B-
In the following formula, Me represents a methyl group.

To a three-necked flask, 5.0 g of D-110N (manufactured by Mitsui Chemicals, Inc.), 5.0 g of Uniox M-4000 (NOF CORPORATION), and 10 g of ethyl acetate were added, and the mixture was stirred at room temperature. The temperature was raised to 60 ° C.
Next, 0.05 g of Neostan U-600 was added to the three-necked flask, and the mixture was heated and stirred for 3 hours. Then, it cooled to room temperature, and wall material B (solid content 50% by mass) was obtained.

-Synthesis of particle 18-
In an aluminum cup, Pionin A-41-C (manufactured by Takemoto Oil & Fat Co., Ltd.) 0.45 g, wall material A 14.99 g, SR-399E (dipentaerythritol pentaacrylate, manufactured by Sartmer) 7.49 g, wall material B 3.78 g and 16.56 g of ethyl acetate were added, and the mixture was stirred at room temperature.
Then, 46.89 g of pure water was added to the aluminum cup, and the mixture was stirred with a homogenizer at 12,000 rpm for 12 minutes. Then, 16.64 g of pure water was further added, the temperature was raised to 45 ° C., and the mixture was heated and stirred for 4 hours.
Then, 5.17 g of a 10% aqueous solution of U-CAT SA 102 was added. Next, the container was placed in a constant temperature bath and aged for 48 hours to obtain a dispersion liquid (solid content 20%) of the particles 18.
The ethylenically unsaturated valency of the particles 18 is 2.01 mmol / g.
The median diameter of the particles 18 was 180 nm, and the coefficient of variation was 29.1%.
The resin contained in the particles 18 is shown below.
In the following resins, the subscripts under each compound (monomer) and the subscripts at the lower right of the parentheses indicate the content ratio (mass ratio).

<Preparation of polymer particles 19 (particles 19)>
-Synthesis of wall material B-
It was synthesized by the same method as the wall material B in the particles 18.

-Synthesis of wall material C-

To a three-necked flask, 1.5 g of the above compound a, 6.0 g of the above compound b, 2.5 g of the above compound c, and 10 g of ethyl acetate were added, stirred at room temperature, and then heated to 60 ° C.
Next, 0.05 g of Neostan U-600 was added to the three-necked flask, and the mixture was heated and stirred for 3 hours. Then, it cooled to room temperature, and wall material C (solid content 50% by mass) was obtained.

-Synthesis of wall material D-

To a three-necked flask, 5.0 g of D-110N (manufactured by Mitsui Chemicals, Inc.), 5.0 g of Unisafe PKA5014-TF (manufactured by NOF CORPORATION), and 10 g of ethyl acetate were added, and the mixture was stirred at room temperature. The temperature was raised to 60 ° C.
Next, 0.05 g of Neostan U-600 was added to the three-necked flask, and the mixture was heated and stirred for 3 hours. Then, it cooled to room temperature, and wall material D (solid content 50% by mass) was obtained.

-Synthesis of particles 19-
In an aluminum cup, Pionin A-41-C (manufactured by Takemoto Oil & Fat Co., Ltd.) 0.45 g, wall material C 14.99 g, SR-399E 7.49 g, wall material B 1.89 g, wall material D 1.89 g, And 16.56 g of ethyl acetate was added, and the mixture was stirred at room temperature.
Then, 46.89 g of pure water was added to the aluminum cup, and the mixture was stirred with a homogenizer at 12,000 rpm for 12 minutes. Then, 16.64 g of pure water was further added, the temperature was raised to 45 ° C., and the mixture was heated and stirred for 4 hours.
Then, 5.17 g of a 10% aqueous solution of U-CAT SA 102 was added. Next, the container was placed in a constant temperature bath and aged for 48 hours to obtain a dispersion liquid (solid content 20%) of the particles 19.
The ethylenically unsaturated valency of particle 19 is 2.01 mmol / g.
The median diameter of the particles 19 was 200 nm, and the coefficient of variation was 28.1%.
The resin contained in the particles 19 is shown below.
In the following resins, the subscripts under each compound (monomer) and the subscripts at the lower right of the parentheses indicate the content ratio (mass ratio).

<Preparation of polymer particles 20 (particles 20)>
-Synthesis of wall material C-
It was synthesized by the same method as the wall material C in the particles 19.

-Synthesis of wall material D-
It was synthesized by the same method as the wall material D in the particles 19.

-Synthesis of particles 20-
In an aluminum cup, 0.45 g of Pionin A-41-C (manufactured by Takemoto Oil & Fat Co., Ltd.), 14.99 g of wall material C, 7.49 g of SR-399E, 3.78 g of wall material D, and 16.56 g of ethyl acetate. It was added and stirred at room temperature.
Then, 46.89 g of pure water was added to the aluminum cup, and the mixture was stirred with a homogenizer at 12,000 rpm for 12 minutes. Then, 16.64 g of pure water was further added, the temperature was raised to 45 ° C., and the mixture was heated and stirred for 4 hours.
Then, 5.17 g of a 10% aqueous solution of U-CAT SA 102 was added. Next, the container was placed in a constant temperature bath and aged for 48 hours to obtain a dispersion liquid (solid content 20%) of the particles 20.
The ethylenically unsaturated valency of the particles 20 is 2.01 mmol / g.
The median diameter of the particles 20 was 195 nm, and the coefficient of variation was 28.5%.
The resin contained in the particles 20 is shown below.
In the following resins, the subscripts under each compound (monomer) and the subscripts at the lower right of the parentheses indicate the content ratio (mass ratio).

<Preparation of polymer particles 21 (particles 21)>
-Synthesis of wall material A-
It was synthesized by the same method as the wall material A in the particles 18.

-Synthesis of wall material B-
It was synthesized by the same method as the wall material B in the particles 18.

-Synthesis of wall material D-
It was synthesized by the same method as the wall material D in the particles 19.

-Synthesis of particles 21-
In an aluminum cup, Pionin A-41-C (manufactured by Takemoto Oil & Fat Co., Ltd.) 0.45 g, wall material A 14.99 g, SR-399E 7.49 g, wall material B 1.89 g, wall material D 1.89 g, And 16.56 g of ethyl acetate was added, and the mixture was stirred at room temperature.
Then, 46.89 g of pure water was added to the aluminum cup, and the mixture was stirred with a homogenizer at 12,000 rpm for 12 minutes. Then, 16.64 g of pure water was further added, the temperature was raised to 45 ° C., and the mixture was heated and stirred for 4 hours.
Then, 5.17 g of a 10% aqueous solution of U-CAT SA 102 was added. Next, the container was placed in a constant temperature bath and aged for 48 hours to obtain a dispersion liquid (solid content 20%) of the particles 21.
The ethylenically unsaturated valency of the particles 21 is 2.01 mmol / g.
The median diameter of the particles 21 was 195 nm, and the coefficient of variation was 28.5%.
The resin contained in the particles 21 is shown below.
In the following resins, the subscripts under each compound (monomer) and the subscripts at the lower right of the parentheses indicate the content ratio (mass ratio). In addition, Me represents a methyl group.

<Preparation of polymer particles 22 (particles 22)>
-Synthesis of wall material A-
It was synthesized by the same method as the wall material A in the particles 18.

-Synthesis of wall material D-
It was synthesized by the same method as the wall material D in the particles 19.

-Synthesis of particles 22-
In an aluminum cup, Pionin A-41-C (manufactured by Takemoto Oil & Fat Co., Ltd.) 0.45 g, wall material A 14.99 g, SR-399E 7.49 g, wall material D 3.78 g, and ethyl acetate 16.56 g. Was added and stirred at room temperature.
Then, 46.89 g of pure water was added to the aluminum cup, and the mixture was stirred with a homogenizer at 12,000 rpm for 12 minutes. Then, 16.64 g of pure water was further added, the temperature was raised to 45 ° C., and the mixture was heated and stirred for 4 hours.
Then, 5.17 g of a 10% aqueous solution of U-CAT SA 102 was added. Next, the container was placed in a constant temperature bath and aged for 48 hours to obtain a dispersion liquid (solid content 20%) of the particles 22.
The ethylenically unsaturated bond value of the particle 22 is 2.01 mmol / g, which corresponds to the specific particle A.
The median diameter of the particles 22 was 185 nm, and the coefficient of variation was 27.5%.
The resin contained in the particles 22 is shown below.
In the following resins, the subscripts under each compound (monomer) and the subscripts at the lower right of the parentheses indicate the content ratio (mass ratio).

(Comparative Example 1)
1. 1. Preparation of lithographic printing plate original plate (1) (1) Preparation of support In order to remove the rolling oil on the surface of an aluminum plate (material JIS A 1050) with a thickness of 0.3 mm, 50 mass% sodium aluminate aqueous solution was used. After degreasing at ℃ for 30 seconds, sand the aluminum surface using ^three bundled nylon brushes with a hair diameter of 0.3 mm and a Pamis-water suspension with a median diameter of 25 μm (specific gravity 1.1 g / cm ³ ). It was sharpened and washed well with water. This plate was immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C. for 9 seconds for etching, washed with water, and then further immersed in 20 mass% nitric acid at 60 ° C. for 20 seconds and washed with water. The etching amount on the sand trimming surface at this time was about 3 g / m ² .

Next, an electrochemical roughening treatment was continuously performed using an AC voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass aqueous solution of nitric acid (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power supply waveform is electrochemically roughened using a carbon electrode as a counter electrode using a trapezoidal square wave AC with a TP of 0.8 msec, a duty ratio of 1: 1 and a time from zero to the peak of the current value. Was done. Ferrite was used as the auxiliary anode. 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. The amount of electricity in nitric acid electrolysis was 175 C / dm ² when the aluminum plate was an anode. Then, it was washed with water by spraying.

Subsequently, nitrate electrolysis was carried out with a 0.5% by mass aqueous solution of hydrochloric acid (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. under the condition of an electric amount of 50 C / dm ² when the aluminum plate was an anode. The surface was subjected to an electrochemical roughening treatment in the same manner as in the above, and then washed with water by spraying.
Next, a DC anodic oxide film having a current density of 15 A / dm ² and 2.5 g / m ² was provided on this plate using 15 mass% aluminum sulfate (containing 0.5 mass% of aluminum ions) as an electrolytic solution, and then washed with water. The support (1) was prepared by drying.
Then, in order to ensure the hydrophilicity of the non-imaged portion, the support (1) was subjected to a silicate treatment at 60 ° C. for 10 seconds using a 2.5 mass% No. 3 sodium silicate aqueous solution, and then washed with water to support it. Body (2) was obtained. The amount of Si adhered was 10 mg / m ² . The center line average roughness (Ra) of this substrate was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.

(2) Formation of Undercoat Layer Next, the following undercoat layer coating solution (1) is applied onto the support (2) so that the dry coating amount is 20 mg / m ² , and the undercoat used in the following experiment is applied. A support with a layer was made.

<Coating liquid for undercoat layer (1)>
-Compound for undercoat layer having the following structure (1): 0.18 g
-Hydroxyethyliminodiacetic acid: 0.10 g
-Methanol: 55.24 g
・ Water: 6.15g

(3) Formation of Image Recording Layer An image recording layer coating liquid (1) having the following composition is bar-coated on the undercoat layer formed as described above, and then dried in an oven at 100 ° C. for 60 seconds. An image recording layer of 1.0 g / m ² was formed.
The image recording layer coating liquid (1) was obtained by mixing and stirring the following photosensitive liquid (1) and microgel liquid (1) immediately before coating.

<Photosensitive liquid (1)>
-Binder polymer (1) [structure below]: 0.240 g
-Infrared absorbing dye (1) [structure below]: 0.030 g
-Polymerization initiator (1) [structure below]: 0.162 g
-Radical polymerizable compound Tris (acryloyloxyethyl) isocyanurate (NK ester A-9300, manufactured by Shin Nakamura Chemical Industry Co., Ltd.): 0.192 g
-Low molecular weight hydrophilic compound Tris (2-hydroxyethyl) isocyanurate: 0.062 g
-Low molecular weight hydrophilic compound (1) [structure below]: 0.050 g
-Fat sensitive agent Phosnium compound (1) [Structure below]: 0.055 g
・ Fat sensitive agent Benzyl-dimethyl-octylammonium ・ PF ₆ salt: 0.018 g
-Fat sensitive agent Ammonium group-containing polymer [the following structure, reduction specific viscosity 44 cSt / (g / ml)]: 0.035 g
-Fluorine-based surfactant (1) [structure below]: 0.008 g
2-Butanone: 1.091 g
1-Methyl-2-propanol: 8.609 g

<Microgel solution (1)>
-Microgel (1): 2.640 g
-Distilled water: 2.425 g

The above-mentioned binder polymer (1), infrared absorbing dye (1), polymerization initiator (1), phosphonium compound (1), low molecular weight hydrophilic compound, (1) ammonium group-containing polymer, and fluorine-based surfactant ( The structure of 1) is as shown below.

-Synthesis of microgel (1)-
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Chemicals, Inc., Takenate D-110N) 10 g, pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., SR444) 3.15 g, and 0.1 g of Pionin A-41C (manufactured by Takemoto Oil & Fat Co., Ltd.) was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4 mass% aqueous solution of Kuraray Poval PVA-205 (polyvinyl alcohol manufactured by Kuraray Co., Ltd., saponification degree of 86.5 mol% to 89.0 mol%) 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 microgel (1). When the average particle size of the microgel was measured by the light scattering method, the average particle size was 0.2 μm.

(4) Formation of Protective Layer A protective layer coating solution (1) having the following composition is further coated on the image recording layer by a bar, then dried in an oven at 120 ° C. for 60 seconds, and the dry coating amount is 0.15 g / m ^2. A lithographic printing plate original plate (1) was obtained by forming a protective layer of.

<Coating liquid for protective layer (1)>
-Inorganic layered compound dispersion (1): 1.5 g
-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 g
-Polyvinyl alcohol (PVA-405 manufactured by Kuraray Co., Ltd., saponification degree 81.5 mol%, polymerization degree 500) 6% by mass aqueous solution: 0.03 g
-1% by mass aqueous solution of surfactant (Emarex 710) manufactured by Nippon Emulsion Co., Ltd .: 0.86 g
-Ion-exchanged water: 6.0 g

-Preparation of inorganic layered compound dispersion (1)-
6.4 g of synthetic mica Somashift ME-100 (manufactured by CO-OP CHEMICAL CO., LTD.) Was added to 193.6 g of ion-exchanged water, and the mixture was dispersed using a homogenizer until the average particle size (laser scattering method) became 3 μm. The aspect ratio of the obtained dispersed particles was 100 or more.

(Comparative Example 2)
A negative infrared-sensitive lithographic printing plate precursor was prepared using a substrate composed of an aluminum plate that had been electrolytically roughened in a hydrochloric acid solution in order to obtain an average roughness (Ra) of 0.4 μm. Next, the aluminum plate is anodized in an aqueous phosphoric acid solution to form a 1.1 g / m ² oxide film, and then coated with a poly (acrylic acid) post-treatment aqueous solution to 0.03 g / m ^2. A dry thickness of m ² was obtained.

An infrared sensitive image-forming layer was formed on a sample of this substrate using the formulations shown in Table 5 below. Each formulation contained a specific combination of Compound A and Compound B shown below. Each formulation was coated onto a substrate using a bar coater, dried at 110 ° C. for 40 seconds and then cooled to 35 ° C. to obtain 1.0 g / m ² of the infrared sensitive image-forming layer. A dry coating mass was obtained, thus forming a negative infrared sensitive lithographic printing plate precursor with each formulation.

Each note in Table 5 is as follows.
1: Urethane acrylate 1 is a reaction product of hexamethylene diisocyanate and dipentaerythritol pentaacrylate.
2: Graft copolymer 1 is prepared according to the process used for Polymer A in US Pat. No. 7,592,128 (bottom of 27 steps), acrylonitrile with a mass ratio of 70:10:20, polyethylene glycol methyl ether methacrylate and A 21% by weight dispersion in an 80/20 mixture of n-propanol / water of a copolymer derived from styrene.
3: Hydroxypropyl methylcellulose 1 is a 30% methoxylated, 10% hydroxypropylated cellulose polymer having a viscosity of 5 mPa seconds in a 2% aqueous solution at 20 ° C.
4: The acrylate ester 1 is an ethoxylated pentaerythritol tetraacrylate having an average ethoxy chain length of 5.
5: IR dye 1 is a compound represented by the following formula. In addition, Ph represents a phenyl group.

6: BYK® 336 is a modified dimethylpolysiloxane copolymer in a 25% xylene / methoxypropyl acetate solution available from BYK Chemie, Wallingford, Connecticut.
Compounds A and B: The compounds shown below, respectively. In addition, Ph represents a phenyl group.

<Evaluation method>
-Caring property-
The obtained planographic 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 750 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 lithographic 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 (capacity ratio) of dampening water and DIC Fusion-G red N ink (manufactured by DIC Graphics Co., Ltd.) are used as standard for LITHRONE26. We supply dampening water and ink by the 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. It was.
The ink density in the solid image area was measured using a Macbeth densitometer (exact manufactured by X-Rite), and the number of printing papers required to reach 1.45 or higher was determined by the ink fillability (initial printing ink adhesion). It was measured as an index of meatiness). It can be said that the smaller the number of sheets, the better the lithographic printing plate is.
-Evaluation criteria-
Evaluation 5: 100 or more Evaluation 4: 50 or more and less than 100 Evaluation 3: 30 or more and less than 50 Evaluation 2: 20 or more and less than 30 Evaluation 1: Less than 20

-Print resistance-
The obtained planographic printing plate original plate is exposed to 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. did. The exposed image included a solid image and a 50% halftone dot chart of a 20 μm dot FM (Frequency Modulation) screen.
The obtained exposed planographic printing plate original plate was attached to the plate cylinder of a printing machine LITHRONE26 manufactured by Komori Corporation without developing. Using Efficiency-2 (manufactured by Fujifilm Co., Ltd.) / tap water = 2/98 (capacity ratio) of dampening water and Values-G (N) ink ink (manufactured by Dainippon Ink and Chemicals Co., Ltd.). After supplying dampening water and ink using the standard automatic printing start method of LITHRONE26 and developing on the machine, Tokuryo Art (ream weight: 76.5 kg, Mitsubishi Paper Mills Limited) at a printing speed of 10,000 sheets per hour. (Manufactured) 100 sheets were printed on paper.
Further, the printing durability was evaluated based on the number of printed sheets at the time when it was visually recognized that the density of the solid image began to decrease as the printing was continued. The print resistance index (print resistance index) was calculated by the following formula based on the fact that 50,000 sheets can be printed.
-Evaluation criteria-
Printing endurance index (%) = [(Number of sheets at the end of printing) / (50,000 sheets)] x 100

-On-board developability-
The obtained planographic 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 750 rpm, a laser output of 70%, and a resolution of 2400 dpi. The exposed image included a solid image and a 50% halftone dot chart of a 20 μm dot FM screen.
The exposed lithographic 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 (capacity ratio) of dampening water and DIC Fusion-G red N ink (manufactured by DIC Graphics Co., Ltd.) are used as standard for LITHRONE26. We supply dampening water and ink by the 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. It was.
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.
-Evaluation criteria-
Evaluation 5: 100 or more Evaluation 4: 50 or more and less than 100 Evaluation 3: 30 or more and less than 50 Evaluation 2: 20 or more and less than 30 Evaluation 1: Less than 20

-Visibility (color development)-
The obtained planographic printing plate original plate was subjected to a water-cooled 40 W infrared semiconductor laser-equipped Creo Trendsetter 3244VX with an output of 11.5 W, an outer drum rotation speed of 220 rpm, and a resolution of 2,400 dpi (dot per inch, 1 inch = 25.4 mm). It was exposed under the conditions. The exposure was performed in an environment of 25 ° C. and 50% RH.
Immediately after the exposure and after storage in a dark place (25 ° C.) for 2 hours after the exposure, 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.

-Development residue suppression during on-machine development (on-machine development residue suppression)-
In the above evaluation of printing durability, after printing was performed, the state of adhesion of the removal residue on the watering roller was evaluated at the same time. The indicators are as follows.
5: No residue can be seen on the watering roller.
4: Slightly dregs can be seen on the watering roller.
3: Scraps can be seen on the watering roller.
2: Many debris can be seen on the watering roller.
1: Very many debris can be seen on the watering roller.

-Contact angle with water-
The obtained planographic printing plate original plate was subjected to a water-cooled 40 W infrared semiconductor laser-equipped Creo Trendsetter 3244VX with an output of 11.5 W, an outer drum rotation speed of 220 rpm, and a resolution of 2,400 dpi (dot per inch, 1 inch = 25.4 mm). It was exposed under the conditions. The exposure was performed in an environment of 25 ° C. and 50% RH.
A contact angle meter (Model: DMC-MC3) manufactured by Kyowa Surface Chemistry Co., Ltd. was used for the measurement. After 1 μL of pure water was dropped onto the image portion produced above, it was defined as the angle between the tangent line of the gas-liquid interface at the intersection of the dropped pure water and the plate surface at 25 ° C. The measurement was carried out at three locations on the same plate, and the average value was taken.

From the results shown in Tables 6 and 7, the lithographic printing plate original plates of Examples 1 to 26, which are the lithographic printing plate original plates according to the present disclosure, have the on-machine developability and the lithographic printing property of the obtained lithographic printing plate. Excellent.
Further, from the results shown in Tables 6 and 7, the lithographic printing plate original plates of Examples 1 to 28, which are the lithographic printing plate original plates according to the present disclosure, are excellent in printing durability and visibility.
Further, from the results shown in Tables 6 and 7, of Examples 14 to 18 in which the compound (leuco dye) represented by any of the formulas (Le-1) to (Le-3) is contained in the image recording layer. The lithographic printing plate original plate is superior in visibility.
Furthermore, from the results shown in Tables 6 and 7, the image recording layer contains polymer particles containing a resin having a structure obtained by at least reacting an isocyanate compound represented by the formula (Iso) with water. The lithographic printing plate original plates 21 to 28 are excellent in the on-machine development residue suppressing property.

<Preparation of undercoat layer coating liquids (2) and (3)>
Undercoat layer coating liquids (2) and (3) having the following compositions were prepared, respectively.

-Composition of undercoat layer coating liquid (2)-
-Polymer (UC-1): 0.18 parts-Surfactant (Emarex 710, manufactured by Nippon Emulsion Co., Ltd.): 0.03 parts-Water: 28.0 parts

-Composition of undercoat layer coating liquid (3)-
-Polymer (UC-1): 0.18 parts-Surfactant (Emarex 710, manufactured by Nippon Emulsion Co., Ltd.): 0.03 parts-Hydrophilic compound: Amount shown in Table 7-Water: 28.0 Department

(Examples 29 to 34)
<Preparation of lithographic printing plate original plate>
This was carried out except that the undercoat layer coating solution shown in Table 8 containing the hydrophilic compounds shown in Table 8 was applied so that the dry coating amount was 20 mg / m ² to form an undercoat layer. In the same manner as in Example 24, lithographic printing plate original plates of Examples 29 to 34 were prepared.
The image recording layer coating liquid was prepared by mixing and stirring the polymer particles immediately before coating.

<Scratch stain suppression evaluation>
The obtained planographic printing plate original plate was used with a Luxel PLATESETTER T-6000III manufactured by FUJIFILM Corporation equipped with an infrared semiconductor laser, and had an outer drum rotation speed of 1,000 rpm (revolutions per minute), a laser output of 70%, and a resolution of 2, The exposure was performed under the condition of 400 dpi (dot per inch). After the exposure treatment, the lithographic printing plate obtained in an environment of a temperature of 25 ° C. and a humidity of 70% RH was scratched by a scratch tester.
As this scratch tester, HEIDON scratching Intersity TESTER HEIDEN-18 was used, and a sapphire needle having a diameter of 0.1 mm was used, and the scratch load was 50 (g). The scratched plate was attached to the plate cylinder of a diamond IF2 printing machine manufactured by Mitsubishi Heavy Industries, Ltd. without developing. Dia IF2 using IF102 (manufactured by FUJIFILM Corporation) / tap water = 3/97 (capacity ratio) dampening water and Values-G (N) ink ink (manufactured by Dainippon Ink and Chemicals Co., Ltd.) After supplying dampening water and ink and developing on the machine using the standard automatic printing start method of, printing is performed using Tokuryo Art (76.5 kg) paper at a printing speed of 10,000 sheets per hour. , It was evaluated whether the scratched part became a printing stain. In addition, the intermediate points such as 9 points and 7 points were evaluated as intermediate points when they were in the middle of the upper limit evaluation criteria. The evaluation standard is preferably 10 to 6 points. The results are shown in Table 8.
-Evaluation criteria-
10 points: The scratched part does not become a print stain.
8 points: Slight print stains that cannot be visually identified are observed on the scratched part.
6 points: Slight print stains are visually observed on the scratched part.
4 points: Printing stains are visually observed on the scratched part.
2 points: Clear printing stains are found on the scratched part

The "surface contact angle" shown in Table 8 represents the contact angle with water by the aerial water droplet method on the surface of the aluminum support on the image recording layer side. The contact angle was measured by the method described above.
The details of the hydrophilic compounds shown in Table 8 are shown below.

(Examples 35 to 38)
<Formation of undercoat layer>
The undercoat layer coating liquid (1) was applied onto the support (support B in Example 38 below) so that the dry coating amount was 23 mg / m ² to form an undercoat layer.

<Formation of image recording layer>
An image recording layer coating solution having the composition shown in Table 9 is bar-coated on the undercoat layer and dried in an oven at 120 ° C. for 40 seconds to form an image recording layer having a dry coating amount of 1.0 g / m ² for lithographic printing. A plate original was prepared.
The image recording layer coating liquid was prepared by mixing the compounds with the compositions shown in Table 9.
The above-mentioned A-1 was used as the low molecular weight hydrophilic compound.

When the evaluation was performed in the same manner as in Example 1 using the lithographic printing plate original plates of Examples 35 to 38, the on-machine developability, the inking property, the printing resistance, the visibility, and the on-machine development residue suppressing property were evaluated. In each case, the same evaluation results as in Example 1 were obtained.

Further, the support B and each component other than those described above shown in Table 9 are shown below.

<Preparation of support B>
In Example 38, the support B was prepared by the following procedure.

-Alkaline etching process-
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 55 ° C. to perform an etching treatment. Then, it was washed with water by spraying. The amount of aluminum dissolved on the surface to be subjected to the electrochemical roughening treatment later was 3 g / m ² .

-Desmat treatment using an acidic aqueous solution (first desmat treatment)-
Next, a desmat treatment was performed using an acidic aqueous solution. As the acidic aqueous solution used for the desmat treatment, an aqueous solution of 170 g / L of sulfuric acid was used. The liquid temperature was 30 ° C. An acidic aqueous solution was sprayed onto an aluminum plate to perform a desmat treatment for 3 seconds. Then, it was washed with water.

-Electrochemical roughening treatment-
Next, an electrochemical roughening treatment was performed using a hydrochloric acid concentration electrolytic solution and an alternating current. The temperature of the electrolytic solution was 40 ° C. The waveform of the alternating current was a sine wave in which the positive and negative waveforms were symmetrical, and the frequency was 50 Hz. The amount of electricity was 300 C / dm ² , which is the total amount of electricity stored in the anodic reaction of the aluminum plate. A carbon electrode was used as the counter electrode of the aluminum plate. Then, it was washed with water.

-Alkaline etching process-
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 is sprayed onto an electrochemically roughened aluminum plate at a temperature of 35 ° C. and the etching amount is 0.1 g / m ² or less. Etching treatment was performed so as to be. Then, it was washed with water.

-Desmat treatment using an acidic aqueous solution-
Next, a desmat treatment was performed using an acidic aqueous solution. As the acidic aqueous solution used for the desmat treatment, an aqueous solution of 170 g / L of sulfuric acid was used. The liquid temperature was 30 ° C. An acidic aqueous solution was sprayed onto an aluminum plate to perform a desmat treatment for 3 seconds. Then, it was washed with water.

-Anodizing treatment-
Anodizing was performed at 170 g / L of sulfuric acid solution and 40 ° C. of the solution temperature using a direct current so that the amount of the anodic oxide film was 3 g / m ² .

<Polymerizable compound>
M'-1: Urethane acrylate synthesized according to the following synthesis example, ethylenically unsaturated bond value: 7.22 mmol / g

<Synthesis of M'-1>
Takenate D-160N (polyisocyanate, manufactured by Mitsui Chemicals, Inc.) 4.7 parts by mass, Aronix M-403 (hydroxyl-containing polyfunctional acrylate, manufactured by Toa Synthetic Co., Ltd.) NCO value and Aronix M- of Takenate D-160N A mixed solution of 0.02 parts by mass of t-butylbenzoquinone and 11.5 parts by mass of methyl ethyl ketone was heated to 65 ° C. in an amount such that the hydroxyl value of 403 was 1: 1. To the reaction solution, 0.11 part by mass of Neostan U-600 (bismuth-based polycondensation catalyst, manufactured by Nitto Kasei Co., Ltd.) was added, and the mixture was heated at the same temperature for 4 hours. The reaction solution was cooled to room temperature (25 ° C.), and methyl ethyl ketone was added to synthesize a urethane acrylate solution having a solid content of 50% by mass.
Subsequently, a recycle type GPC (equipment: LC908-C60, column: JAIGEL-1H-40 and 2H-40 (manufactured by Nippon Analytical Industry Co., Ltd.)) was used in a tetrahydrofuran (THF) eluent, and the molecular weight of the urethane acrylate solution was increased. Fractionation was carried out to obtain urethane acrylate M'-1.

<Electron-accepting polymerization initiator>
I'-1 and I'-2: The following compounds <infrared absorber>
D'-1 ~ D'-3: The following compounds Incidentally, Bu represents a n- butyl group, TsO ^- represents tosylate anion.

<Color former>
S'-1: S-15 described above
S'-2: S-16 described above

<Surfactant>
U'-2: The following polymers, fluoroaliphatic group-containing copolymers

<Additives>
O'-1: The following compounds

<Preparation of polymer particles P-3>
-Preparation of oil phase components-
WANNAME (registered trademark) PM-200 (polyfunctional isocyanate compound: manufactured by Manka Kagaku Co., Ltd.): 6.66 g and Takenate (registered trademark) D-116N (trimethylolpropane (TMP) and m-xylylene diisocyanate (XDI)) 50% by mass ethyl acetate solution of an adduct (structure below) of polyethylene glycol monomethyl ether (EO90): 5.46 g and SR399 (dipentaerythritol pentaacrylate: manufactured by Sartomer). A 65 mass% ethyl acetate solution: 11.24 g, ethyl acetate: 14.47 g, and Pionin (registered trademark) A-41-C (manufactured by Takemoto Oil & Fat Co., Ltd.): 0.45 g were mixed and mixed at room temperature (25 ° C.). ) Was stirred for 15 minutes to obtain an oil phase component.

-Preparation of aqueous phase components-
As an aqueous phase component, 47.2 g of distilled water was prepared.

-Microcapsule forming process-
The aqueous phase component was added to the oil phase component and mixed, and the obtained mixture was emulsified with a homogenizer at 12,000 rpm for 16 minutes to obtain an emulsion.
16.8 g of distilled water was added to the obtained emulsion, and the obtained liquid was stirred at room temperature for 180 minutes.
Next, the stirred liquid was heated to 45 ° C., and the mixture was stirred for 5 hours while maintaining the liquid temperature at 45 ° C. to distill off ethyl acetate from the above liquid. The solid content concentration was adjusted to 20% by mass with distilled water to obtain an aqueous dispersion of polymer particles P-3. The volume average particle size of P-3 was 165 nm as measured by a laser diffraction / scattering type particle size distribution measuring device LA-920 (manufactured by Horiba Seisakusho Co., Ltd.).

<Binder polymer>
P'-1: Partially acetylated polyvinyl butyral, Sekisui Chemical Co., Ltd. Eslek BL10

Disclosure of Japanese Patent Application No. 2019-12480 filed on June 28, 2019, Disclosure of Japanese Patent Application No. 2019-158815 filed on August 30, 2019, and September 2019. The disclosure of Japanese Patent Application No. 2019-169811, filed on the 18th, 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.

18: Aluminum plate, ta: Anode reaction time, ct: Cathode reaction time, tp: Time from 0 to peak of current, Ia: Peak current on anode cycle side, Ic: Peak time on cathode cycle side Current, AA: Anode reaction current of aluminum plate, CA: Electrode reaction current of aluminum plate, 10: Flat plate printing plate original plate, 12a, 12b: Aluminum support, 14: Undercoat layer, 16: Image recording layer, 20a, 20b: Anodized film, 22a, 22b: Micropore, 24: Large-diameter hole, 26: Small-diameter hole, D: Depth of large-diameter hole, 50: Main electrolytic tank, 51: AC power supply, 52: Radial Drum roller, 53a, 53b: main electrode, 54: electrolyte supply port, 55: electrolyte, 56: auxiliary anode, 60: auxiliary anode tank, W: aluminum plate, A1: liquid supply direction, A2: electrolyte discharge direction , 410: Anodizing device, 412: Power supply tank, 414: Electrolytic treatment tank, 416: Aluminum plate, 418,426: Electrolyte, 420: Power supply electrode, 422,428: Roller, 424: Nip roller, 430: Electrolysis Electrode 432: Tank wall, 434: DC power supply

Claims (50)

1. It has an aluminum support and an image recording layer on the aluminum support.
   The image recording layer contains an infrared absorber, a polymerization initiator, a polymerizable compound having a molecular weight of less than 2,500, and a polymer having a molecular weight of 2,500 or more and having a polymerizable group.
   An on-machine development type lithographic printing plate original plate in which the polymerizable compound contains a polymerizable compound having 7 or more functionalities.
2. The on-board development type lithographic printing plate original plate according to claim 1, wherein the contact angle with water by aerial water droplets on the outermost layer surface on the image recording layer side of the lithographic printing plate original plate is 30 ° to 80 °.
3. In the image recording layer, when the content of the polymer having a polymerizable group is Mp and the content of the polymerizable compound having 7 or more functionalities is Mm, the value of Mm / Mp is 0.01 or more. The machine-developed lithographic printing plate original plate according to claim 1 or 2.
4. The on-board development type lithographic printing plate original plate according to any one of claims 1 to 3, wherein the polymer having a polymerizable group contains polymer particles having a polymerizable group.
5. The machine-developed lithographic printing plate original plate according to claim 4, wherein the polymer particles have a hydrophilic group.
6. The machine-developed lithographic printing plate original plate according to claim 5, wherein the polymer particles have a polyalkylene oxide structure as the hydrophilic group.
7. The machine-developed lithographic printing plate original plate according to claim 6, wherein the polymer particles have a polypropylene oxide structure as the polyoxyalkylene oxide structure.
8. The machine-developed lithographic printing plate original plate according to claim 6 or 7, wherein the polymer particles have at least a polyethylene oxide structure and a polypropylene oxide structure as the polyoxyalkylene oxide structure.
9. The on-machine development according to any one of claims 4 to 8, wherein the polymer particles contain a resin having a structure obtained by at least reacting an isocyanate compound represented by the following formula (Iso) with water. Planographic printing plate Original plate.
   

   

   
   In the formula (Iso), n represents an integer from 0 to 10.
10. The polymer particles have a structure obtained by at least reacting an isocyanate compound represented by the formula (Iso) with water, and include a resin having a polyethylene oxide structure and a polypropylene oxide structure as a polyoxyalkylene structure. The machine-developed lithographic printing plate original plate according to claim 9.
11. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 10, wherein the polymer having a polymerizable group is an addition polymerization type resin.
12. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 11, wherein the polymer having a polymerizable group contains a styrene-acrylonitrile copolymer.
13. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 12, wherein the image recording layer is the outermost layer.
14. The on-machine development type lithographic printing plate according to any one of claims 1 to 13, wherein the contact angle with water by the aerial water droplet method on the surface of the aluminum support on the image recording layer side is 110 ° or less. Original version.
15. The machine-developed lithographic printing plate original plate according to claim 14, wherein the contact angle with water by the aerial water droplet method on the surface of the aluminum support on the image recording layer side is 80 ° or less.
16. The machine-developed lithographic printing plate original plate according to claim 15, wherein the contact angle with water by the aerial water droplet method on the surface of the aluminum support on the image recording layer side is 50 ° or less.
17. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 16, wherein the layer on the aluminum support contains hydroxycarboxylic acid or a salt thereof.
18. The machine-developed lithographic printing plate original plate according to claim 17, wherein the hydroxycarboxylic acid or a salt thereof contains a compound having two or more hydroxy groups.
19. The machine-developed lithographic printing plate original plate according to claim 17 or 18, wherein the hydroxycarboxylic acid or a salt thereof contains a compound having three or more hydroxy groups.
20. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 19, wherein the polymerizable compound further contains a polymerizable compound having six functions or less.
21. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 20, wherein the polymerization initiator contains an electron-accepting polymerization initiator.
22. The machine-developed lithographic printing plate original plate according to claim 21, wherein the value of LUMO of the infrared absorber-LUMO of the electron-accepting polymerization initiator is 0.70 eV or less.
23. The machine-developed lithographic printing plate original plate according to claim 21 or 22, wherein the electron-accepting polymerization initiator contains a compound represented by the following formula (II).
    

    

    
    In formula (II), X represents a halogen atom and R ³ represents an aryl group.
24. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 23, wherein the polymerization initiator contains an electron donating type polymerization initiator.
25. The machine-developed lithographic printing plate original plate according to claim 24, wherein the value of HOMO of the infrared absorber-HOMO of the electron donating type polymerization initiator is 0.70 eV or less.
26. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 25, wherein the image recording layer further contains a color former.
27. The machine-developed lithographic printing plate original plate according to claim 26, wherein the color former is an acid color former.
28. The machine-developed lithographic printing plate original plate according to claim 27, wherein the acid color former is a leuco dye.
29. The machine-developed lithographic printing plate original plate according to claim 28, wherein the leuco dye is a leuco dye having a phthalide structure or a fluorine structure.
30. The machine-developed lithographic printing plate original plate according to claim 29, wherein 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). ..
    

    

    
    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 is absent and Y ₂ is N, then X ₄ is absent, Ra ₁ represents a hydrogen atom, an alkyl group or an alkoxy group, and Rb ₁ to Rb ₄ are independent alkyl groups. Or represents an aryl group.
31. The on-board development type according to claim 29 or 30, wherein the leuco dye having a phthalide structure or a fluorine structure is a compound represented by any of the following formulas (Le-4) to (Le-6). Planographic printing plate original plate.
    

    

    
    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 an alkyl group or an aryl group, respectively.
32. The method according to any one of claims 29 to 31, wherein the leuco dye having a phthalide structure or a fluorine structure is a compound represented by any of the following formulas (Le-7) to (Le-9). On-board development type lithographic printing plate original plate.
    

    

    
    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 are independent hydrogen atoms and alkyl, respectively. Represents a group or an alkoxy group, Rb ₁ to Rb ₄ independently represent an alkyl group or an aryl group, and Rc ₁ and Rc ₂ each independently represent an aryl group.
33. The machine-developed lithographic printing plate original plate according to claim 32, wherein Ra ₁ to Ra ₄ are independently alkoxy groups.
34. The machine-developed lithographic printing plate original plate according to claim 32 or 33, wherein the leuco dye having the phthalide structure or the fluorine structure is a compound represented by the formula (Le-8).
35. The machine-developed lithographic printing plate original plate according to claim 34, wherein X ₁ to X ₄ are hydrogen atoms and Y ₁ and Y ₂ are C.
36. The machine-developed lithographic printing plate original plate according to claim 34 or 35, wherein Rb ₁ and Rb ₂ are independently alkyl groups.
37. Any of claims 1 to 36, wherein the infrared absorber has an organic anion in which δd in the solubility parameter of Hansen is 16 or more, δp is 16 or more and 32 or less, and δh is 60% or less of δp. The machine-developed lithographic printing plate original plate described in item 1.
38. Claims 23 to 23, wherein the electron-accepting polymerization initiator has an organic anion in which δd in the solubility parameter of Hansen is 16 or more, δp is 16 or more and 32 or less, and δh is 60% or less of δp. The machine-developed planographic printing plate original plate according to any one of 25.
39. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 38, wherein the image recording layer further contains polyvinyl acetal.
40. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 39, wherein the image recording layer further contains a fluoroaliphatic group-containing copolymer.
41. The machine-developed lithographic printing according to claim 40, wherein the fluoroaliphatic group-containing copolymer has a structural unit formed of a compound represented by any of the following formulas (F1) and (F2). Original version.
    

    

    
    In formulas (F1) and (F2), R ^F1 independently represents a hydrogen atom or a methyl group, and X independently represents an oxygen atom, a sulfur atom, or -N ( ^RF2 )-. m represents an integer of 1 ~ 6, n represents an integer of 1 ~ 10, l represents an integer of 0 ~ ^{10, R F2} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
42. 41. The claim 41, wherein the fluoroaliphatic group-containing copolymer further comprises a structural unit formed of at least one compound selected from the group consisting of poly (oxyalkylene) acrylate and poly (oxyalkylene) methacrylate. On-board development type lithographic printing plate original plate.
43. The method according to any one of claims 1 to 42, wherein the image recording layer contains a compound having an ethylenically unsaturated bond value of 5.0 mmol / g or more as the polymerizable compound or the polymer having a polymerizable group. The above-mentioned on-board development type lithographic printing plate original plate.
44. The machine-developed lithographic printing plate original plate according to claim 43, wherein the compound having an ethylenically unsaturated bond value of 5.0 mmol / g or more is a compound represented by the following formula (I).
    Formula (I): X- (Y) _n
    In formula (I), X represents an n-valent organic group having a hydrogen-bonding group, Y represents a monovalent group having two or more ethylenically unsaturated groups, and n represents an integer of two or more. The molecular weight of X / (molecular weight of Y × n) is 1 or less.
45. According to claim 43 or 44, the compound having an ethylenically unsaturated bond value of 5.0 mmol / g or more has at least one structure selected from the group consisting of an adduct structure, a biuret structure, and an isocyanurate structure. The described on-board development type lithographic printing plate original plate.
46. The machine-developed lithographic printing plate original plate according to any one of claims 1 to 45, wherein the polymerizable compound contains a compound having one or two ethylenically unsaturated groups.
47. The aluminum support has an aluminum plate and an anodized film of aluminum arranged on the aluminum plate.
    The average diameter of the micropores on the surface of the anodized film is more than 10 nm and 100 nm or less.
    The method according to any one of claims 1 to 46, wherein the value of the lightness L ^* in the surface of the anodic oxide film on the image recording layer side is 70 to 100 in the L ^* a ^* b ^* color system. Machine-developed planographic printing plate original plate.
48. The micropore communicates with a large-diameter hole extending from the surface of the anodized film to a depth of 10 nm to 1,000 nm and the bottom of the large-diameter hole, and has a depth of 20 nm to 2,000 nm from the communicating position. It is composed of a small diameter hole that extends to the position,
    The average diameter of the large-diameter pore portion on the surface of the anodized film is 15 nm to 100 nm.
    The machine-developed lithographic printing plate original plate according to claim 47, wherein the average diameter of the small-diameter hole portion at the communication position is 13 nm or less.
49. The step of exposing the on-machine development type lithographic printing plate original plate according to any one of claims 1 to 48 like an image, and
    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.
50. The step of exposing the on-machine development type lithographic printing plate original plate according to any one of claims 1 to 48 like an image, and
    A step 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.

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