Lithographic printing plate precursor, method for producing lithographic printing plate, and lithographic printing method

Abstract

A lithographic printing plate precursor having a support and an image recording layer on the support, the image recording layer containing a (meth) acrylic polymer A having a substituent group including two or more silicon atoms in a side chain.

Description

Technical Field

[0001] The present invention relates to an original lithographic printing plate, a method for producing a lithographic printing plate, and a lithographic printing method. Background Art

[0002] Generally, a lithographic printing plate is composed of a lipophilic image area that receives ink during printing and a hydrophilic non-image area that receives dampening solution. Lithographic printing is a method in which, utilizing the property that water and oil-based ink repel each other, the lipophilic image area of the lithographic printing plate is used as the ink-receiving area, and the hydrophilic non-image area is used as the dampening solution-receiving area (non-ink-receiving area). An adhesion difference of ink is generated on the surface of the lithographic printing plate, and after the ink is only inked on the image area, the ink is transferred to a printing object such as paper for printing.

[0003] To produce this lithographic printing plate, an original lithographic printing plate (also referred to as a PS plate) in which a lipophilic image recording layer is provided on a hydrophilic support has been widely used in the past. Generally, a lithographic printing plate is obtained by plate-making through the following method: after exposing the original lithographic printing plate to a original image such as a high-contrast film, a part of the image recording layer that becomes the image area is left, and the unnecessary image recording layer other than this is dissolved and removed by an alkaline developing solution or an organic solvent, so that the surface of the hydrophilic support is exposed and a non-image area is formed.

[0004] As a conventional original lithographic printing plate, there is known an original lithographic printing plate that contains a compound having a substituent containing a silicon atom in the image recording layer (for example, refer to Japanese Patent Application Laid-Open No. 2009-237381, Japanese Patent Application Laid-Open No. 2004-029680, Japanese Patent Application Laid-Open No. 2006-235390, Japanese Patent Application Laid-Open No. 09-054432). Summary of the Invention

[0005] Technical Problem to be Solved by the Invention

[0006] A problem to be solved by one embodiment of the present invention is to provide an original lithographic printing plate having an image recording layer with excellent coating film surface state.

[0007] Another problem 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 original lithographic printing plate.

[0008] Means for Solving the Technical Problem

[0009] The present invention includes the following embodiments.

[0010] <1> An original lithographic printing plate having a support and an image recording layer on the support,

[0011] The image recording layer contains a (meth)acrylic polymer A having a substituent containing two or more silicon atoms on the side chain.

[0012] <2>A lithographic printing plate precursor having a support and an image recording layer on the support,

[0013] The image recording layer contains a polymer B having a structural unit represented by the following formula (I).

[0014] [Chemical formula 1]

[0015]

[0016] In formula (I), R 11 and R 12 each independently represent a hydrogen atom or an alkyl group, R 13 represents a hydrogen atom or a monovalent substituent, L 11 and L 12 each independently represent a single bond or a divalent linking group, and Rh represents a substituent containing two or more silicon atoms.

[0017] <3>The lithographic printing plate precursor according to <1> or <2>, which is an on-press developable lithographic printing plate precursor.

[0018] <4>The lithographic printing plate precursor according to any one of <1> to <3>, wherein

[0019] the above image recording layer further contains resin particles.

[0020] <5>The lithographic printing plate precursor according to any one of <1> to <3>, wherein

[0021] the above image recording layer further contains a color former.

[0022] <6>The lithographic printing plate precursor according to any one of <1>, <3> to <5>, wherein

[0023] the above (meth)acrylic polymer A is a copolymer containing a structural unit having a substituent containing two or more silicon atoms on the side chain and a structural unit having a hydrophilic group on the side chain.

[0024] <7>The lithographic printing plate precursor according to any one of <1>, <3> to <6>, wherein

[0025] the above (meth)acrylic polymer A is a copolymer containing a structural unit having a substituent containing two or more silicon atoms on the side chain and a structural unit having a polyalkyleneoxy group on the side chain.

[0026] <8>The lithographic printing plate original according to <2> to <5>, wherein,

[0027] In the above formula (I), Rh is a group containing two or more structures represented by the following formula (Ia).

[0028] [Chemical formula 2]

[0029]

[0030] In formula (Ia), * represents the bonding position, R 11 , R 12 and R 13 each independently represents an alkyl group, an alkenyl group, an aryl group or an alkylene aryl group.

[0031] <9>The lithographic printing plate original according to any one of <2> to <5>, wherein,

[0032] The above polymer B is a copolymer further having a structural unit with a hydrophilic group on the side chain.

[0033] <10>The lithographic printing plate original according to <9>, wherein,

[0034] The structural unit having a hydrophilic group on the side chain is a structural unit represented by the following formula (a4).

[0035] [Chemical formula 3]

[0036]

[0037] In formula (a4), R 7 and R 8 each independently represents a hydrogen atom or an alkyl group, R 9 represents a hydrogen atom or a monovalent substituent, L 2 represents -C(=O)-O- or -C(=O)-NH-, L 3 represents a single bond or a divalent linking group, and X represents a hydrophilic group.

[0038] <11>The lithographic printing plate original according to <10>, wherein,

[0039] In the above formula (a4), L 2 represents -C(=O)-NH-.

[0040] <12>The lithographic printing plate original according to <10> or <11>, wherein,

[0041] In the above formula (a4), the hydrophilic group represented by X is a hydroxyl group, a polyalkyleneoxy group or a group formed by combining two or more of them.

[0042] <13>The lithographic printing plate precursor according to any one of <2>, <3>, <8> to <12>, wherein,

[0043] The above-mentioned polymer B is a copolymer further having a structural unit with a polyalkyleneoxy group in the side chain.

[0044] <14>The lithographic printing plate precursor according to any one of <2>, <8> to <13>, wherein,

[0045] L in the above formula (I) 11 is an ester bond.

[0046] <15>A method for producing a lithographic printing plate, comprising:

[0047] The step of exposing the lithographic printing plate precursor according to any one of <3> to <14> into an image; and

[0048] The step of supplying at least one selected from printing ink and dampening solution on a printing press to remove the image recording layer of the non-image part.

[0049] <16>A lithographic printing method, comprising:

[0050] The step of exposing the lithographic printing plate precursor according to any one of <3> to <14> into an image;

[0051] The step of supplying at least one selected from printing ink and dampening solution on a printing press to remove the image recording layer of the non-image part to produce a lithographic printing plate; and

[0052] The step of performing printing using the obtained lithographic printing plate.

[0053] Advantages of the Invention

[0054] According to one embodiment of the present invention, it is possible to provide a lithographic printing plate precursor having an image recording layer with excellent coating film surface properties.

[0055] Moreover, 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 lithographic printing plate precursor. Description of the Drawings

[0056] Figure 1 is a schematic cross-sectional view of one embodiment of an aluminum support preferably used in the present invention.

[0057] Figure 2 is a schematic cross-sectional view of one embodiment of an aluminum support having an anodic oxide film.

[0058] Figure 3It is a diagram showing an example of an alternating current waveform graph used in the electrochemical roughening treatment in the manufacturing method of an aluminum support having an anodic oxide film.

[0059] Figure 4 It is a side view showing an example of an electrolytic cell (radial type unit) in the electrochemical roughening treatment using alternating current in the manufacturing method of an aluminum support having an anodic oxide film.

[0060] Figure 5 It is a side view showing the concept of the process of a brushing abrasive plate used in the mechanical roughening treatment in the manufacturing method of an aluminum support having an anodic oxide film.

[0061] Figure 6 It is a schematic diagram of an anodizing treatment apparatus used in the anodizing treatment in the manufacturing method of an aluminum support having an anodic oxide film. Detailed Description of the Invention

[0062] Hereinafter, the content of the present invention will be described in detail. The description of the constituent elements described below is based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment.

[0063] 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.

[0064] Moreover, in the notation of groups (atomic groups) in this specification, the notation without indicating substitution and unsubstituted not only includes groups without substituents, but also includes groups with substituents. For example, "alkyl" includes not only alkyl without substituents (unsubstituted alkyl), but also alkyl with substituents (substituted alkyl).

[0065] In this specification, "(meth)acrylic acid" is a term used to include both acrylic acid and methacrylic acid, and "(meth)acryloyl" is a term used to include both acryloyl and methacryloyl.

[0066] And, the term "process" in this specification includes not only independent processes, but also includes this term even in cases where it cannot be clearly distinguished from other processes as long as the intended purpose of the process can be achieved.

[0067] In the present invention, the meaning of "mass%" is the same as that of "weight%", and the meaning of "parts by mass" is the same as that of "parts by weight".

[0068] In the present invention, unless otherwise specified, each component in the composition may be contained singly as one kind, or two or more kinds may be used simultaneously. Further, in the present invention, unless otherwise specified, each structural unit in the polymer or polymers may be contained singly as one kind, or two or more kinds may be used simultaneously.

[0069] In addition, in the present invention, regarding the amounts of the respective components in the composition or the respective structural units in the polymer, in the case where there are a plurality of substances or structural units corresponding to the respective components in the composition or the respective structural units in the polymer, unless otherwise specified, it means the total amount of the corresponding plurality of substances present in the composition or the corresponding plurality of respective structural units present in the polymer.

[0070] In addition, in the present invention, a combination of two or more preferred modes is a more preferred mode.

[0071] Further, unless otherwise specified, the weight-average molecular weight (Mw) and the number-average molecular weight (Mn) in the present invention are the molecular weights in terms of polystyrene measured by a gel permeation chromatography (GPC) apparatus using columns of TSKgel GMHxL, TSKgel G4000HxL, and TSKgel G2000HxL (all are trade names manufactured by TOSOH CORPORATION), with solvent THF (tetrahydrofuran) and a differential refractometer for detection.

[0072] In the present invention, the term "original planographic printing plate" includes not only the original planographic printing plate but also the original waste plate. And the term "planographic printing plate" includes not only the planographic printing plate prepared by operations such as exposure and development of the original planographic printing plate as needed, but also the waste plate. In the case of the original waste plate, operations such as exposure and development are not necessarily required. In addition, the waste plate refers to, for example, an original planographic printing plate used for mounting on an unused printing plate cylinder when a part of a layout is printed in monochrome or two colors in color newspaper printing.

[0073] In the present invention, "excellent printing durability" means that the number of printable sheets of the planographic printing plate is large. Hereinafter, the printing durability when an ultraviolet curable ink (UV ink) is used as the ink during printing is also referred to as "UV printing durability".

[0074] Hereinafter, the present invention will be described in detail.

[0075] (Original planographic printing plate)

[0076] Regarding a first embodiment of a lithographic printing plate precursor (also simply referred to as "lithographic printing plate precursor") according to the present invention, it has a support and an image recording layer on the support, and the image recording layer contains a (meth)acrylic polymer A having a substituent containing two or more silicon atoms in a side chain.

[0077] Regarding a second embodiment of the lithographic printing plate precursor according to the present invention, it has a support and an image recording layer on the support, and the image recording layer contains a polymer B having a structural unit (b1) represented by the following formula (I).

[0078] [Chemical formula 3]

[0079]

[0080] In formula (I), R 11 and R 12 each independently represent a hydrogen atom or an alkyl group, R 13 represents a hydrogen atom or a monovalent substituent, L 11 and L 12 each independently represent a single bond or a divalent linking group, and Rh represents a substituent containing two or more silicon atoms.

[0081] In addition, in this specification, unless otherwise specified, when simply referred to as "the lithographic printing plate precursor according to the present invention", it refers to the case of describing both the above first embodiment and the above second embodiment. And unless otherwise specified, when simply referred to as "image recording layer" or the like, it describes the image recording layer or the like of both the above first embodiment and the above second embodiment.

[0082] As a result of intensive studies by the present inventors, it has been found that by adopting the above structure, a lithographic printing plate precursor having an image recording layer with excellent coating film surface properties can be provided.

[0083] Although the detailed mechanism for obtaining the above effects is not clear, it is speculated as follows.

[0084] It is considered that in the above first embodiment, the (meth)acrylic polymer A having a substituent containing two or more silicon atoms in a side chain contained in the image recording layer is likely to be biased on the surface when forming the image recording layer due to the structure of the side chain, thus contributing to the surface smoothness of the image recording layer.

[0085] It is considered that in the above second embodiment, the polymer B having the structural unit (b1) represented by the above formula (I) contained in the image recording layer is also likely to be biased on the surface when forming the image recording layer due to the structure of the side chain, thus contributing to the surface smoothness of the image recording layer.

[0086] It is speculated that, as a result, unevenness is not easily visually recognizable on the visual surface, and thus an image recording layer with excellent coating film surface condition can be obtained.

[0087] In addition, hereinafter, "coating film surface condition" may sometimes be simply referred to as "surface condition".

[0088] Furthermore, it is considered that in the case where the lithographic printing plate original of the present invention is an on-press developable lithographic printing plate original, the (meth)acrylic polymer A or polymer B biased towards the surface of the image recording layer can improve the wettability of the dampening solution to the surface of the lithographic printing plate original (i.e., the surface of the image recording layer) and the permeability of the dampening solution to the image recording layer due to the presence of silicon atoms in the side chain. Thus, it is speculated that the on-press developable lithographic printing plate original as the lithographic printing plate original of the present invention exhibits particularly excellent on-press developability.

[0089] Herein, the "on-press developable lithographic printing plate original" refers to a lithographic printing plate original that, after being exposed, is not developed in the conventional manner but is directly installed on a printing press and used for "on-press development" to remove the unnecessary portions of the image recording layer at the initial stage of the normal printing process.

[0090] [(Meth)acrylic polymer A having a substituent containing two or more silicon atoms in the side chain]

[0091] In the first embodiment of the lithographic printing plate original of the present invention, the image recording layer contains a (meth)acrylic polymer A having a substituent containing two or more silicon atoms in the side chain.

[0092] The (meth)acrylic polymer A has a structure in which a side chain having a substituent containing two or more silicon atoms is bonded to a main chain composed of a (meth)acrylic resin chain.

[0093] As the substituent containing two or more silicon atoms, there is no particular limitation as long as the atomic group constituting the substituent contains two or more silicon atoms. From the viewpoint of on-press developability, the substituent containing two or more silicon atoms preferably contains a silicon atom as a silicon-oxygen bond (Si-O bond). The substituent containing two or more silicon atoms preferably has two or more silicon-oxygen bonds, more preferably three or more, and further preferably three to twelve. The substituent containing two or more silicon atoms preferably contains a silicon-oxygen bond as a polysiloxane structure.

[0094] And, from the viewpoint of on-press developability, the substituent containing two or more silicon atoms preferably has a branched structure, and more preferably has a branched structure branched around a silicon atom.

[0095] As a substituent containing two or more silicon atoms, a group having two or more structures represented by the following formula (a1) is preferred.

[0096] [Chemical formula 4]

[0097]

[0098] In the above formula (a1), * represents the bonding position, and R 1 , R 2 , and R 3 each independently represent an alkyl group, an alkenyl group, an aryl group, or an alkylene aryl group.

[0099] As the alkyl group represented by R 1 , R 2 , and R 3 , for example, a linear alkyl group having 1 to 18 carbon atoms, a branched or cyclic alkyl group having 3 to 18 carbon atoms can be mentioned. As the above alkyl group, specifically, methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, cyclohexyl, etc. can be mentioned.

[0100] As the alkenyl group represented by R 1 , R 2 , and R 3 , for example, an alkenyl group having 2 to 12 carbon atoms can be mentioned. As the above alkenyl group, specifically, vinyl, 1-propenyl, 1-butenyl, 1-methyl-1-propenyl, 1-cyclopentenyl, 1-cyclohexenyl, etc. can be mentioned.

[0101] As the aryl group represented by R 1 , R 2 , and R 3 , for example, an aryl group having 6 to 12 carbon atoms can be mentioned. As the above aryl group, specifically, phenyl, α-methylphenyl, naphthyl, etc. can be mentioned.

[0102] As the alkylene aryl group represented by R 1 , R 2 , and R 3 , for example, an alkylene aryl group having 7 to 30 carbon atoms can be mentioned.

[0103] In formula (a1), R 1 , R 2 , and R 3 are each independently preferably an alkyl group, more preferably all the same alkyl group, still more preferably all alkyl groups having 1 to 4 carbon atoms, and particularly preferably all methyl groups.

[0104] The substituent containing two or more silicon atoms is preferably a group containing three or more structures represented by the above formula (a1), and more preferably a group containing three to six structures represented by the above formula (a1).

[0105] Substituents containing two or more silicon atoms are preferably groups represented by the following formula (a2).

[0106] [Chemical formula 5]

[0107]

[0108] In the above formula (a2), * represents the bonding position, and R 1 , R 2 , and R 3 each independently represent an alkyl group, an alkenyl group, an aryl group, or an alkylene aryl group.

[0109] R 1 , R 2 , and R 3 in formula (a2) have the same meaning as R 1 , R 2 , and R 3 in the above formula (a1), and the preferred modes are also the same.

[0110] From the viewpoint of obtaining more excellent on-machine developability, the (meth)acrylic polymer A is preferably a copolymer containing a structural unit having a substituent containing two or more silicon atoms on the side chain and a structural unit having a hydrophilic group on the side chain.

[0111] As the structural unit having a hydrophilic group on the side chain, a structural unit having a polyalkyleneoxy on the side chain is preferred. That is, the (meth)acrylic polymer A is preferably a copolymer containing a structural unit having a substituent containing two or more silicon atoms on the side chain and a structural unit having a polyalkyleneoxy on the side chain.

[0112] As the structural unit having a substituent containing two or more silicon atoms on the side chain, for example, a structural unit having two or more groups represented by formula (a1) on the side chain can be cited, and a structural unit having a group represented by the above formula (a2) on the side chain is preferred.

[0113] Specifically, the structural unit having a substituent containing two or more silicon atoms on the side chain is preferably a structural unit represented by the following formula (a3).

[0114] [Chemical formula 6]

[0115]

[0116] In formula (a3), R 1 , R 2 , and R 3 each independently represent an alkyl group, an alkenyl group, an aryl group, or an alkylene aryl group, and R 4 , and R5 Each independently represents a hydrogen atom or an alkyl group, R 6 represents a hydrogen atom or a monovalent substituent, L 1 represents a p + 1-valent linking group, where p represents an integer from 2 to 12.

[0117] R in formula (a3) 1 , R 2 and R 3 have the same meanings as R in the above formula (a1) 1 , R 2 and R 3 , and the preferred embodiments are also the same.

[0118] As the alkyl group represented by R 4 and R 5 , for example, a linear alkyl group having 1 to 18 carbon atoms, a branched or cyclic alkyl group having 3 to 18 carbon atoms can be cited. As the above alkyl group, specifically, methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, cyclohexyl, etc. can be cited.

[0119] As R 4 and R 5 , both are preferably hydrogen atoms.

[0120] As the monovalent substituent represented by R 6 , for example, an alkyl group, an alkenyl group or an aryl group can be cited. The above alkyl group, alkenyl group and aryl group are the same as the alkyl group, alkenyl group and aryl group represented by R 1 , R 2 and R 3 , and the preferred embodiments are also the same.

[0121] As R 6 , it is preferably a hydrogen atom or a methyl group.

[0122] The p + 1-valent linking group represented by L 1 , for example, a p + 1-valent hydrocarbon group having 1 to 10 carbon atoms can be cited. As the p + 1-valent linking group, a hydrocarbon group in which a part of the carbon atoms constituting the hydrocarbon group is substituted by a heteroatom is also preferably used. As the hydrocarbon group, a saturated hydrocarbon group is preferred. Here, as the heteroatom substituting a part of the carbon atoms, for example, a silicon atom, an oxygen atom and a nitrogen atom can be cited, and among them, a silicon atom or an oxygen atom is preferred.

[0123] The p + 1-valent linking group represented by L 1 is preferably a branched saturated hydrocarbon group, and a branched saturated hydrocarbon group in which a part of the carbon atoms constituting the branched saturated hydrocarbon group is substituted by a heteroatom (preferably a silicon atom and an oxygen atom) is also preferred.

[0124] p is an integer from 2 to 12, preferably an integer from 3 to 12.

[0125] As a specific example of a monomer unit for forming a structural unit having a substituent containing two or more silicon atoms on the side chain, monomers represented by K-1 to K-12 can be cited. The specific example of the monomer unit for forming a structural unit having a substituent containing two or more silicon atoms on the side chain is not limited thereto.

[0126] In the following structure, n is an integer of 2 to 1000.

[0127] [Chemical formula 7]

[0128]

[0129] The structural unit having a hydrophilic group on the side chain contained in the (meth)acrylic polymer A is preferably a structural unit represented by the following formula (a4).

[0130] [Chemical formula 8]

[0131]

[0132] In formula (a4), R 7 and R 8 each independently represent a hydrogen atom or an alkyl group, R 9 represents a hydrogen atom or a monovalent substituent, L 2 represents -C(=O)-O- or -C(=O)-NH-, L 3 represents a single bond or a divalent linking group, and X represents a hydrophilic group.

[0133] The alkyl groups represented by R 7 and R 8 are the same as the alkyl groups represented by R 4 and R 5 in the above formula (a3), and the preferred modes are also the same.

[0134] The monovalent substituent represented by R 9 is the same as the monovalent substituent represented by R 6 in the above formula (a3), and the preferred modes are also the same.

[0135] The divalent linking group represented by L 3 is not particularly limited as long as it is a group capable of linking L 2 and X. As the divalent linking group represented by L 3 alkylenes can be cited. As the alkylene, an alkylene having 2 to 10 carbon atoms is preferred, and an alkylene having 4 to 8 carbon atoms is more preferred.

[0136] Examples of the hydrophilic group represented by X include a hydroxyl group, a phosphate group, a polyalkyleneoxy group, or a group formed by combining two or more of them. Here, examples of the polyalkyleneoxy group include a polyethyleneoxy group, a polypropyleneoxy group, a polybutyleneoxy group, or a group formed by combining them.

[0137] Specific examples of the monomer unit for forming the structural unit having a hydrophilic group in the side chain include monomers represented by H-1 to H-25. The specific examples of the monomer unit for forming the structural unit having a hydrophilic group in the side chain are not limited thereto.

[0138] In the following structure, n and m are each independently an integer of 2 to 100.

[0139] In the following structure, the description "random" means that a plurality of polyalkyleneoxy groups are randomly arranged.

[0140] [Chemical formula 9]

[0141]

[0142]

[0143] (Meth)acrylic polymer A may contain alone one kind of structural unit having a substituent containing two or more silicon atoms in the side chain, or may contain two or more kinds.

[0144] In (meth)acrylic polymer A, the content of the structural unit having a substituent containing two or more silicon atoms in the side chain may be 100% by mass based on the mass of (meth)acrylic polymer A, preferably 15% by mass to 70% by mass, more preferably 20% by mass to 60% by mass, and still more preferably 25% by mass to 50% by mass.

[0145] And, (meth)acrylic polymer A may contain alone one kind of structural unit having a hydrophilic group in the side chain, or may contain two or more kinds.

[0146] In (meth)acrylic polymer A, the content of the structural unit having a hydrophilic group in the side chain is preferably 30% by mass to 85% by mass, more preferably 40% by mass to 80% by mass, and still more preferably 50% by mass to 75% by mass based on the mass of (meth)acrylic polymer A.

[0147] In addition, (meth)acrylic polymer A may further contain other structural units.

[0148] As other structural units, for example, structural units having a carboxyl group in the side chain can be mentioned. As the structural units having a carboxyl group in the side chain, for example, (meth)acrylic acid, itaconic acid, itaconic acid derivatives, etc. can be mentioned. The structural units having a carboxyl group in the side chain are preferably included as structural units different from the structural units having the hydrophilic groups described above in the side chain.

[0149] As other structural units, (meth)acrylic acid alkyl esters (the number of carbon atoms of the alkyl group is 1 to 24), styrene derivatives, maleic anhydride, maleimide anhydride, (meth)acrylonitrile, vinyl ether derivatives, alkyl (meth)acrylamide derivatives, etc. can be mentioned.

[0150] In the (meth)acrylic polymer A, the content of other structural units is preferably 0% by mass to 20% by mass with respect to the mass of the (meth)acrylic polymer A.

[0151] As the weight average molecular weight of the (meth)acrylic polymer A, from the viewpoint of obtaining an excellent planar image recording layer, it is preferably 5000 to 100000, more preferably 8000 to 60000.

[0152] As specific examples of the (meth)acrylic polymer A, P-1 to P-10 shown in the following examples can be mentioned. The specific examples of the (meth)acrylic polymer A are not limited to these.

[0153] The content of the (meth)acrylic polymer A is preferably set to 0.001% by mass to 0.1% by mass, more preferably set to 0.002% by mass to 0.01% by mass with respect to the total mass of the coating liquid for the image recording layer.

[0154] [Polymer B]

[0155] Polymer B has a structural unit (b1) represented by the following formula (I).

[0156] [Chemical formula 10]

[0157]

[0158] In formula (I), R 11 and R 12 each independently represent a hydrogen atom or an alkyl group, R 13 represents a hydrogen atom or a monovalent substituent, L 11 and L 12 each independently represent a single bond or a divalent linking group, and Rh represents a substituent containing two or more silicon atoms.

[0159] Consisting of R 11 and R 12The alkyl group represented is the same as the R in the above formula (a3), and the preferred mode is also the same. 4 and R 5 The alkyl group represented is the same, and the preferred mode is also the same.

[0160] The monovalent substituent represented by R 13 is the same as the monovalent substituent represented by R in the above formula (a3), and the preferred mode is also the same. 6 The monovalent substituent represented by R

[0161] The divalent linking group represented by L 11 can be, for example, -C(=O)-O- (so-called ester bond) or -C(=O)-NH-.

[0162] In addition, the divalent linking group represented by L 11 is preferably -C(=O)-O- as the ester bond.

[0163] The divalent linking group represented by L 12 is not particularly limited as long as it can link L 11 and Rh. As the divalent linking group represented by L 12 can be, for example, an alkylene group. The alkylene group is the same as the alkylene group in L of formula (a4) 3 and the preferred mode is also the same.

[0164] The substituent containing two or more silicon atoms represented by Rh is the same as the substituent containing two or more silicon atoms in the (meth)acrylic polymer A, and the preferred mode is also the same.

[0165] Specifically, Rh in formula (I) is preferably a group containing two or more structures represented by the following formula (Ia).

[0166] [Chemical formula 11]

[0167]

[0168] In formula (Ia), * represents the bonding position, and R 11 , R 12 and R 13 each independently represent an alkyl group, an alkenyl group, an aryl group or an aralkyl group.

[0169] Here, formula (Ia) has the same meaning as formula (a1) in the (meth)acrylic polymer A, and the preferred mode is also the same.

[0170] As a specific example of the structural unit (b1) represented by the formula (I), a structural unit of a monomer represented by K-1 to K-12 can be cited, which is derived from a specific example of a structural unit having a substituent containing two or more silicon atoms in the side chain in the (meth)acrylic polymer A. The specific example of the structural unit (b1) represented by the formula (I) is not limited thereto.

[0171] The polymer B preferably further has a structural unit having a hydrophilic group in the side chain.

[0172] As a structural unit having a hydrophilic group in the side chain, in one embodiment, a structural unit having a polyalkyleneoxy in the side chain is preferred. That is, in one embodiment, the polymer B is preferably a copolymer further having a structural unit (b2) having a polyalkyleneoxy in the side chain.

[0173] The structural unit having a hydrophilic group in the side chain in the polymer B is the same as the structural unit having a hydrophilic group in the side chain in the (meth)acrylic polymer A, and the preferred embodiments are also the same.

[0174] That is, as another embodiment of the structural unit having a hydrophilic group in the side chain in the polymer B, a structural unit represented by the above formula (a4) can be cited.

[0175] In the formula (a4), R 7 , R 8 , R 9 , L 2 , L 3 and the preferred embodiments of X are as described above.

[0176] When the structural unit having a hydrophilic group in the side chain in the polymer B is a structural unit represented by the formula (a4), L 2 represents -C(=O)-O- or -C(=O)-NH-, and among them, -C(=0)-NH- is preferred.

[0177] Furthermore, when the structural unit having a hydrophilic group in the side chain in the polymer B is a structural unit represented by the formula (a4), as the hydrophilic group represented by X in the formula (a4), a hydroxyl group, a polyalkyleneoxy, or a group formed by combining two or more of them can be preferably cited.

[0178] As a specific example of the structural unit having a hydrophilic group in the side chain in the polymer B, a structural unit of a monomer represented by H-1 to H-40 can be cited, which is derived from a specific example of a structural unit having a hydrophilic group in the side chain in the (meth)acrylic polymer A. The specific example of the structural unit having a hydrophilic group in the side chain in the polymer B is not limited thereto.

[0179] Polymer B may contain one structural unit (b1) represented by the above formula (I) alone, or may contain two or more kinds thereof.

[0180] In Polymer B, the content of the structural unit (b1) represented by formula (I) may be 100% by mass, preferably 15% by mass to 70% by mass, more preferably 20% by mass to 60% by mass, and still more preferably 25% by mass to 50% by mass, based on the mass of Polymer B.

[0181] Moreover, with respect to Polymer B, in the case of containing a structural unit having a hydrophilic group in the side chain, it may contain one structural unit having a hydrophilic group selected from the structural unit (b2) having a hydrophilic group in the side chain and the structural unit (a4) having a hydrophilic group in the side chain alone, or may contain two or more kinds thereof.

[0182] In Polymer B, the content of the structural unit having a hydrophilic group in the side chain is preferably 30% by mass to 85% by mass, more preferably 40% by mass to 80% by mass, and still more preferably 50% by mass to 75% by mass, based on the mass of Polymer B.

[0183] In addition, Polymer B may further contain other structural units.

[0184] As other structural units, for example, a structural unit having a carboxyl group in the side chain can be cited. As a structural unit having a carboxyl group in the side chain, for example, (meth)acrylic acid, itaconic acid, itaconic acid derivatives, etc. can be cited. The structural unit having a carboxyl group in the side chain is preferably contained as a structural unit different from the structural unit having the above-described hydrophilic group in the side chain.

[0185] As other structural units, (alkyl meth)acrylate (the number of carbon atoms of the alkyl group is 1 to 24), styrene derivatives, maleic anhydride, maleimide anhydride, (meth)acrylonitrile, vinyl ether derivatives, alkyl (meth)acrylamide derivatives, etc. can be cited.

[0186] In Polymer B, the content of other structural units is preferably 0% by mass to 20% by mass, based on the mass of Polymer B.

[0187] As the weight average molecular weight of Polymer B, from the viewpoint of obtaining an excellent planar image recording layer, it is preferably 5000 to 100000, more preferably 8000 to 60000.

[0188] As specific examples of Polymer B, P-1 to P-10 shown in the following examples can be cited. The specific examples of Polymer B are not limited to these.

[0189] The content of Polymer B is preferably 0.001% by mass to 0.1% by mass, more preferably 0.002% by mass to 0.01% by mass, based on the total mass of the coating liquid for the image recording layer.

[0190] The original lithographic printing plate of the present invention has no particular limitation other than having an image recording layer containing the above-mentioned (meth)acrylic polymer A or Polymer B.

[0191] The original lithographic printing plate of the present invention can be a positive original lithographic printing plate or a negative original lithographic printing plate. Among them, from the viewpoint of further exerting the effects of the present invention, the original lithographic printing plate of the present invention is preferably a negative original lithographic printing plate.

[0192] Furthermore, from the viewpoint of showing excellent on-press developability as described above, the original lithographic printing plate of the present invention is preferably an on-press developable original lithographic printing plate.

[0193] Hereinafter, the details of each component in the original lithographic printing plate of the present invention will be described.

[0194] <Image recording layer>

[0195] As the image recording layer used in the present invention, as long as it contains the above-mentioned (meth)acrylic polymer A or Polymer B, it can be a positive image recording layer or a negative image recording layer. Among them, from the viewpoint of further exerting the effects of the present invention, the image recording layer is preferably a negative image recording layer.

[0196] Moreover, as the image recording layer used in the present invention, for example, it can be a thermal positive type as described in Japanese Patent Laid-Open No. 7-285275, Japanese Patent Laid-Open No. 2003-345014, etc., or a thermal negative type as described in Japanese Patent Laid-Open No. 7-20625, Japanese Patent Laid-Open No. 11-218903, etc., or a photopoly negative type as described in Japanese Patent Laid-Open No. 2001-100412, Japanese Patent Laid-Open No. 2002-169282, Japanese Patent Laid-Open No. 2008-15504, etc.

[0197] In addition, the image recording layer used in the present invention is preferably a water-soluble or water-dispersible negative image recording layer. And for the original lithographic printing plate of the present invention, from the viewpoint of on-press developability, it is preferred that the unexposed portion of the image recording layer can be removed by at least one of dampening solution and printing ink.

[0198] Hereinafter, a negative image recording layer suitable for an on-press developable original lithographic printing plate will be described in detail as an example.

[0199] In addition to the above-mentioned (meth)acrylic polymer A or polymer B, the negative image recording layer suitable for the original plate of the on-machine development type lithographic printing plate preferably contains, for example, an infrared absorber, a polymerization initiator, a polymerizable compound, a color former, particles, and other components.

[0200] 〔Infrared absorber〕

[0201] There is no particular limitation on the infrared absorber. For example, pigments and dyes can be cited.

[0202] As the dyes that can be used as infrared absorbers, commercially available dyes and known dyes described in documents such as "Dye Handbook" (edited by The Society of Synthetic Organic Chemistry, Japan, published in 1970) can be used. Specifically, azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methylene dyes, cyanine dyes, squarylium dyes, pyranylium salts, metal thiol complexes, etc. can be cited.

[0203] Among these dyes, preferred dyes include cyanine pigments, squarylium dyes, pyranylium salts, nickel thiol complexes, and indocyanine pigments. More preferably, cyanine pigments and indocyanine pigments are selected. Among them, cyanine pigments are particularly preferred.

[0204] As the infrared absorber, a cationic polymethine pigment having an oxygen atom, a nitrogen atom, or a halogen atom at the meta position is preferred. As the cationic polymethine pigment, cyanine pigments, pyranylium pigments, thiopyrylium pigments, azulium pigments, etc. can be preferably cited. From the viewpoints of ease of acquisition and solvent solubility during the introduction reaction, cyanine pigments are preferred.

[0205] As specific examples of cyanine pigments, the compounds described in paragraphs 0017 to 0019 of JP-A-2001-133969, paragraphs 0016 to 0021 of JP-A-2002-023360, and paragraphs 0012 to 0037 of JP-A-2002-040638 can be cited. Preferably, the compounds described in paragraphs 0034 to 0041 of JP-A-2002-278057 and paragraphs 0080 to 0086 of JP-A-2008-195018 can be cited. Particularly preferably, the compounds described in paragraphs 0035 to 0043 of JP-A-2007-90850 and paragraphs 0105 to 0113 of JP-A-2012-206495 can be cited.

[0206] Moreover, it is also possible to preferably use the compounds described in paragraphs 0008 to 0009 of Japanese Patent Laid-Open No. 5-5005 and paragraphs 0022 to 0025 of Japanese Patent Laid-Open No. 2001-222101.

[0207] As the pigment, the compounds described in paragraphs 0072 to 0076 of Japanese Patent Laid-Open No. 2008-195018 are preferably used.

[0208] Moreover, as the infrared absorber, it is also possible to preferably use the decomposable compound that decomposes upon infrared exposure, which will be described later, as the color-changing compound for the outermost layer.

[0209] From the viewpoint of printing durability, the highest occupied molecular orbital (HOMO) of the infrared absorber is preferably -5.250 eV or less, more preferably -5.30 eV or less, further preferably -5.80 eV or more and -5.35 eV or less, and particularly preferably -5.65 eV or more and -5.40 eV or less.

[0210] From the viewpoints of stability over time, improved sensitivity, and UV printing durability, the lowest unoccupied molecular orbital (LUMO) of the infrared absorber is preferably less than -3.70 eV, more preferably less than -3.80 eV, further preferably -4.20 eV or more and less than -3.80 eV, and particularly preferably -4.00 eV or more and less than -3.80 eV.

[0211] Only one type of infrared absorber may be used, or two or more types may be used simultaneously.

[0212] Moreover, as the infrared absorber, a pigment and a dye may be used simultaneously.

[0213] The content of the infrared absorber is preferably 0.1% by mass to 10.0% by mass, more preferably 0.5% by mass to 5.0% by mass, relative to the total mass of the image recording layer.

[0214] [Polymerization initiator]

[0215] There is no particular limitation on the polymerization initiator, and known polymerization initiators can be used.

[0216] As the polymerization initiator, it preferably contains an electron-donating type polymerization initiator, and more preferably contains an electron-accepting type polymerization initiator and an electron-donating type polymerization initiator.

[0217] [Electron-donating type polymerization initiator (polymerization aid)]

[0218] The electron-donating type polymerization initiator is a compound that generates polymerization initiating species such as free radicals by intermolecular electron transfer to supply an electron to the orbital from which an electron of the infrared absorber is detached when the electron of the infrared absorber is excited or moves within the molecule by infrared exposure.

[0219] As the electron-donating type polymerization initiator, an electron-donating type radical polymerization initiator is preferred.

[0220] The electron-donating type polymerization initiator preferably contains a boron compound, more preferably contains a borate compound, further preferably contains a tetraaryl borate compound, and particularly preferably contains a tetraphenyl borate compound.

[0221] As the borate compound, from the viewpoint of printing durability, a tetraaryl borate compound or a monoalkyl triaryl borate compound is preferred, and a tetraaryl borate compound is more preferred.

[0222] Moreover, as the borate compound, from the viewpoint of printing durability, a tetraaryl borate compound having one or more electron-donating groups or electron-withdrawing groups is preferred, and a tetraaryl borate compound having one electron-donating group or electron-withdrawing group on each aryl group is more preferred.

[0223] As the electron-donating group, from the viewpoint of printing durability, an alkyl group or an alkoxy group is preferred, and an alkoxy group is more preferred.

[0224] As the electron-withdrawing group, from the viewpoint of decomposability, a halogen atom, a haloalkyl group, an acyl group, a carboxyl group, etc. can be mentioned.

[0225] As the counter cation of the borate compound, there is no particular limitation, but an alkali metal ion or a tetraalkylammonium ion is preferred, and a sodium ion, a potassium ion or a tetrabutylammonium ion is more preferred.

[0226] Moreover, as the counter cation of the borate compound, among the infrared absorbers described in this specification, it can be a cationic polymethine dye. For example, as the counter cation of a cyanine dye, the above-mentioned borate compound can be used.

[0227] Specifically, as the borate compound, sodium tetraphenylborate can be preferably cited.

[0228] The following shows B-1 to B-9 as preferred specific examples of the electron-donating type polymerization initiator. Of course, it is not limited to these. And in the following chemical formulas, Ph represents a phenyl group and Bu represents a n-butyl group.

[0229] [Chemical formula 12]

[0230]

[0231] Also, from the viewpoint of improving sensitivity, the highest occupied molecular orbital (HOMO) of the electron-donating polymerization initiator is preferably -6.00 eV or more, more preferably -5.95 eV or more, further preferably -5.93 eV or more, and particularly preferably greater than -5.90 eV.

[0232] And as the upper limit, it is preferably -5.00 eV or less, more preferably -5.40 eV or less.

[0233] The electron-donating polymerization initiator may be used alone or two or more kinds may be used simultaneously.

[0234] As the content of the electron-donating polymerization initiator, from the viewpoints of sensitivity and printing durability, it is preferably 0.01% by mass to 30% by mass, more preferably 0.05% by mass to 25% by mass, and further preferably 0.1% by mass to 20% by mass with respect to the total mass of the image recording layer.

[0235] Also, from the viewpoint of UV printing durability, the content of the electron-donating polymerization initiator in the image recording layer is preferably more than the content of the infrared absorber, more preferably 1.1 to 5 times the content of the infrared absorber, and particularly preferably 1.5 to 3 times the content of the infrared absorber.

[0236] In the present invention, the polymerization initiator may be a compound in which an electron-donating polymerization initiator and an electron-accepting polymerization initiator form a counterion salt.

[0237] For example, in the present invention, a compound in which an anion in the electron-donating polymerization initiator and a cation in the electron-accepting polymerization initiator form a counterion salt is preferred, a compound in which an onium cation and a borate anion form a counterion salt is more preferred, a compound in which an iodonium cation or a sulfonium cation and a borate anion form a counterion salt is further preferred, and a compound in which a diaryliodonium cation or a triarylsulfonium cation and a tetraarylborate anion form a counterion salt is particularly preferred.

[0238] As the preferred modes of the anion in the electron-donating polymerization initiator and the cation in the electron-accepting polymerization initiator, they are the same as the preferred modes of the anion in the electron-donating polymerization initiator and the cation in the electron-accepting polymerization initiator described above.

[0239] When the image recording layer contains an anion as the electron-donating polymerization initiator and a cation as the electron-accepting polymerization initiator (that is, when it contains a compound forming the above counterion salt), the image recording layer contains an electron-accepting polymerization initiator and the above electron-donating polymerization initiator.

[0240] Moreover, a compound in which an electron-donating polymerization initiator and an electron-accepting polymerization initiator form a counterion salt can be used as an electron-donating polymerization initiator or as an electron-accepting polymerization initiator.

[0241] Furthermore, a compound formed by an electron-donating polymerization initiator and an electron-accepting polymerization initiator forming a counterion salt can be used simultaneously with the electron-donating polymerization initiator described above or can be used simultaneously with the electron-accepting polymerization initiator described above.

[0242] The image recording layer in the original plate for on-machine developing lithographic printing plate further contains an infrared absorber and an electron-donating polymerization initiator. From the viewpoint of improving sensitivity and printing durability, the value of HOMO of the above infrared absorber - HOMO of the above electron-donating polymerization initiator is preferably 0.70 eV or less, more preferably 0.60 eV or less, still more preferably 0.50 eV or less, and particularly preferably 0.50 eV to -0.10 eV.

[0243] In addition, a negative value means that the HOMO of the above electron-donating polymerization initiator is higher than the HOMO of the above infrared absorber.

[0244] In the present invention, the MO (molecular orbital) energy of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is calculated by the following method.

[0245] First, the free counterions in the compound to be calculated are excluded from the calculation object. For example, in a cationic electron-accepting polymerization agent and a cationic infrared absorber, the counteranion is excluded from the calculation object, and in an anionic electron-donating polymerization agent, the countercation is excluded from the calculation object. The free here means that the compound as the object and its counterion are not connected by a covalent bond.

[0246] Using the quantum chemistry calculation software Gaussian16, structural optimization is carried out under DFT (B3LYP / 6-31G(d)).

[0247] Regarding the MO energy calculation, the optimal structure obtained through the above structural optimization is used to perform the calculation under DFT (B3LYP / 6-31+G(d,p) / PCM(solvent = methanol)) using the quantum chemistry calculation software Gaussian16. In addition, for a compound containing iodine, the calculation is carried out under the condition of DFT (B3LYP / DGDZVP / PCM(solvent = methanol)).

[0248] The optimal structure mentioned here refers to the structure with the most stable total energy obtained through DFT calculation. The structural optimization is repeated as needed to find the most stable structure.

[0249] According to the following formula, convert the MO energy Ebare (unit: hartree) obtained by the above-mentioned MO energy calculation into Escaled (unit: eV) used as the values of HOMO and LUMO in the present invention.

[0250] [Calculation formula for HOMO] Escaled = 0.823168 × 27.2114 × Ebare - 1.07634

[0251] [Calculation formula for LUMO] Esca]ed = 0.820139 × 27.2114 × Ebare - 1.086039

[0252] In addition, 27.2114 is a coefficient only used for converting hartree to eV, and 0.823168 and -1.07634 used in the calculation of HOMO and 0.820139 and -1.086039 used in the calculation of LUMO are adjustment coefficients, and are determined in such a way that the calculations of HOMO and LUMO of the compound to be calculated match the measured values.

[0253] [Electron-accepting polymerization initiator]

[0254] An electron-accepting polymerization initiator is a compound that generates polymerization initiation species such as free radicals by accepting one electron through intermolecular electron transfer when the electrons of the infrared absorber are excited by infrared exposure.

[0255] An electron-accepting polymerization initiator is a compound that generates polymerization initiation species such as free radicals or cations by light, heat, or the energy of both, and known thermal polymerization initiators, compounds having bonds with small bond dissociation energies, photoinitiators, etc. can be appropriately selected and used.

[0256] As the electron-accepting polymerization initiator, a radical polymerization initiator is preferred, and an onium salt compound is more preferred.

[0257] Moreover, as the electron-accepting polymerization initiator, an infrared-sensitive polymerization initiator is preferred.

[0258] In addition, as the electron-accepting polymerization initiator, from the viewpoints of improving sensitivity and UV printing durability, an iodonium salt compound or a compound having a halogenated alkyl group is preferred, and a compound having a halogenated alkyl group is more preferred.

[0259] Furthermore, as the compound having a halogenated alkyl group, from the viewpoints of improving sensitivity and UV printing durability, a compound having a perhalogenated alkylsulfonyl group is preferred, a compound having a trihalomethylsulfonyl group is more preferred, and a compound having a tribromomethylsulfonyl group is particularly preferred.

[0260] Among the above electron-accepting polymerization initiators, as preferred electron-accepting polymerization initiators, from the viewpoint of curability, oxime ester compounds and onium salt compounds can be cited. Among them, from the viewpoint of printing durability, iodonium salt compounds, sulfonium salt compounds or azinium salt compounds are preferred, iodonium salt compounds or sulfonium salt compounds are more preferred, and iodonium salt compounds are particularly preferred.

[0261] Specific examples of these compounds are shown below, but the present invention is not limited thereto.

[0262] As an example of the iodonium salt compound, a diaryliodonium salt compound is preferred. In particular, a diphenyliodonium salt compound substituted with an electron-donating group such as an alkyl group or an alkoxy group is more preferred, and an asymmetric diphenyliodonium salt compound is preferred. As specific examples, diphenyliodonium = hexafluorophosphate, 4-methoxyphenyl-4-(2-methylpropyl)phenyl iodonium = hexafluorophosphate, 4-(2-methylpropyl)phenyl-p-tolyl iodonium = hexafluorophosphate, 4-hexyloxyphenyl-2,4,6-trimethoxyphenyl iodonium = hexafluorophosphate, 4-hexyloxyphenyl-2,4-diethoxyphenyl iodonium = tetrafluoroborate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyl iodonium = 1-perfluorobutanesulfonate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyl iodonium = hexafluorophosphate, and bis(4-tert-butylphenyl)iodonium = tetraphenylborate can be cited.

[0263] Moreover, as examples of the counter anions of the iodonium salt compound and the sulfonium salt compound, a sulfonate anion, a carboxylate anion, a tetrafluoroborate anion, a hexafluorophosphate anion, a p-toluenesulfonate anion, a p-toluenesulfonate anion, a sulfonamide anion or a sulfimide anion can be cited.

[0264] Among them, a sulfonamide anion or a sulfimide anion is preferred, and a sulfimide anion is more preferred.

[0265] As the sulfonamide anion, an arylsulfonamide anion is preferred.

[0266] Moreover, as the sulfimide anion, a bisarylsulfimide anion is preferred.

[0267] As specific examples of the sulfonamide anion or the sulfimide anion, the compounds described in International Publication No. 2019 / 013268 can be cited.

[0268] Furthermore, as the above electron-accepting polymerization initiator, from the viewpoints of developability and UV printing durability in the obtained lithographic printing plate, a compound represented by the following formula (II) or formula (III) is preferably included, and a compound represented by formula (II) is particularly preferably included.

[0269] [Chemical Formula 13]

[0270]

[0271] In Formula (II) and Formula (III), X A represents a halogen atom, and R A , R A1 and R A2 each independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms.

[0272] R in Formula (II) A is preferably an aryl group.

[0273] As X in Formula (II) and Formula (III) A , a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom can be mentioned.

[0274] Among these, regarding the chlorine atom or the bromine atom, since the sensitivity is excellent, it is preferably used, and particularly preferably a bromine atom.

[0275] Moreover, in Formula (II) and Formula (III), R A , R A1 and R A2 each independently are preferably aryl groups, and among them, from the viewpoint of excellent balance between sensitivity and storage stability, an aryl group substituted with an amide group is more preferable.

[0276] Moreover, as the above-described electron-accepting type polymerization initiator, a compound represented by Formula (IV) is particularly preferably included.

[0277] [Chemical Formula 14]

[0278]

[0279] In Formula (IV), X A represents a halogen atom, R A3 and R A4 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, and pA and qA each independently represent an integer of 1 to 5. Among them, pA + qA = 2 to 6.

[0280] As a specific example of the electron-accepting type polymerization initiator, compounds shown below etc. can be mentioned, but the present invention is not limited to these.

[0281] In the following structures, "Et" represents an ethyl group, "nPr" represents a n-propyl group, "nBu" represents a n-butyl group, "Ph" represents a phenyl group, and "cHex" represents a cyclohexyl group.

[0282] [Chemical Formula 15]

[0283]

[0284] [Chemical Formula 16]

[0285]

[0286] [Chemical Formula 17]

[0287]

[0288] [Chemical Formula 18]

[0289]

[0290] [Chemical Formula 19]

[0291]

[0292] [Chemical Formula 20]

[0293]

[0294] [Chemical Formula 21]

[0295]

[0296] From the viewpoint of improving sensitivity, the lowest unoccupied molecular orbital (LUMO) of the electron-accepting polymerization initiator is preferably -3.00 eV or lower, more preferably -3.02 eV or lower.

[0297] Moreover, as the lower limit, it is preferably -3.80 eV or higher, more preferably -3.50 eV or higher.

[0298] The electron-accepting polymerization initiator may be used alone or two or more kinds may be used simultaneously.

[0299] The content of the electron-accepting polymerization initiator is preferably 0.1 mass% to 50 mass%, more preferably 0.5 mass% to 30 mass%, and particularly preferably 0.8 mass% to 20 mass% with respect to the total mass of the image recording layer.

[0300] The image recording layer in the on-machine developable lithographic printing plate original further contains an infrared absorber and an electron-accepting polymerization initiator. From the viewpoints of improving sensitivity and printing durability, the value of LUMO of the above electron-accepting polymerization initiator - LUMO of the above infrared absorber is preferably 1.00 eV or lower, more preferably 0.80 eV or lower, further preferably 0.70 eV or lower, particularly preferably 0.70 eV to -0.10 eV, and most preferably 0.70 eV to 0.30 eV.

[0301] In addition, the negative value means that the LUMO of the above infrared absorber is higher than the LUMO of the above electron-accepting polymerization initiator.

[0302] [Polymeric compound]

[0303] In the present invention, the polymeric compound refers to a compound having a polymerizable group.

[0304] The polymerizable group is not particularly limited as long as it is a known polymerizable group, but an ethylenically unsaturated group is preferred. Also, as the polymerizable group, it can be a free-radical polymerizable group or a cationic polymerizable group, but a free-radical polymerizable group is preferred.

[0305] Examples of the free-radical polymerizable group include (meth)acryloyl, allyl, vinylphenyl, vinyl, etc. From the viewpoint of reactivity, (meth)acryloyl is preferred.

[0306] The molecular weight of the polymeric compound (weight-average molecular weight in the case of having a molecular weight distribution) is preferably 50 or more and less than 2,500.

[0307] The polymeric compound used in the present invention can be, for example, a free-radical polymerizable compound or a cationic polymerizable compound, and an addition polymerizable compound having at least 1 ethylenically unsaturated bond, i.e., an ethylenically unsaturated compound, is preferred.

[0308] As the ethylenically unsaturated compound, a compound having at least 1 terminal ethylenically unsaturated bond is preferred, and a compound having 2 or more terminal ethylenically unsaturated bonds is more preferred. The polymeric compound has, for example, chemical forms such as monomers, prepolymers, i.e., dimers, trimers, or oligomers, or mixtures thereof.

[0309] Among them, as the polymeric compound, from the viewpoint of UV printing durability, a polymeric compound having 3 or more functional groups is preferred, a polymeric compound having 7 or more functional groups is more preferred, and a polymeric compound having 10 or more functional groups is further preferred. Also, from the viewpoint of UV printing durability in the lithographic printing plate obtained, the above polymeric compound preferably contains an ethylenically unsaturated compound having 3 or more functional groups (preferably 7 or more functional groups, more preferably 10 or more functional groups), and further preferably contains a (meth)acrylate compound having 3 or more functional groups (preferably 7 or more functional groups, more preferably 10 or more functional groups).

[0310] Also, as the polymeric compound, from the viewpoints of on-press developability and contamination inhibition, a polymeric compound having 2 or less functional groups is preferred, a polymeric compound having 2 functional groups is more preferred, and a 2-functional (meth)acrylate compound is particularly preferred.

[0311] From the viewpoints of printing durability, on-machine developability, and contamination suppression, the content of the polymerizable compound having 2 or less functional groups (preferably a 2-functional polymerizable compound) is preferably 5% by mass to 100% by mass, more preferably 10% by mass to 100% by mass, and particularly preferably 50% by mass to 100% by mass with respect to the total mass of the polymerizable compounds in the above image recording layer.

[0312] 《Oligomer》

[0313] As the polymerizable compound contained in the image recording layer, a polymerizable compound that is an oligomer (hereinafter, also simply referred to as "oligomer") is preferably contained.

[0314] In the present invention, an oligomer means a polymerizable compound having a molecular weight of 600 or more and 10,000 or less and containing at least 1 polymerizable group. Here, when the oligomer has a molecular weight distribution, it means the weight-average molecular weight.

[0315] From the viewpoints of excellent chemical resistance and UV printing durability, the molecular weight of the oligomer is preferably 1,000 or more and 5,000 or less.

[0316] Furthermore, from the viewpoint of improving UV printing durability, the number of polymerizable groups in one molecule of the oligomer is preferably 2 or more, more preferably 3 or more, further preferably 6 or more, and particularly preferably 10 or more.

[0317] Moreover, the upper limit value of the number of polymerizable groups in the oligomer is not particularly limited, but the number of polymerizable groups is preferably 20 or less.

[0318] From the viewpoints of UV printing durability and on-machine developability, the oligomer preferably has 7 or more polymerizable groups and a molecular weight of 1,000 or more and 10,000 or less, and more preferably has 7 or more and 20 or less polymerizable groups and a molecular weight of 1,000 or more and 5,000 or less.

[0319] In addition, the oligomer may contain a polymer component that may be generated during the production of the oligomer.

[0320] From the viewpoints of UV printing durability and on-machine developability, the oligomer preferably has at least 1 selected from a compound having a urethane bond, a compound having an ester bond, and a compound having an epoxy residue, and preferably has a compound having a urethane bond.

[0321] In the present invention, an epoxy residue means a structure formed by an epoxy group, and for example, represents the same structure as that obtained by the reaction of an acid group (such as a carboxylic acid group) with an epoxy group.

[0322] Compounds having a urethane bond as an example of oligomers are, for example, preferably compounds having at least a group represented by the following formula (Ac-1) or formula (Ac-2), and more preferably compounds having at least a group represented by the following formula (Ac-1).

[0323] [Chemical formula 22]

[0324]

[0325] In formula (Ac-1) and formula (Ac-2), L 1 ~L 4 each independently represents a divalent hydrocarbon group having 2 to 20 carbon atoms, and the wavy line portion represents the bonding position to other structures.

[0326] As L 1 ~L 4 , each independently is preferably an alkylene group having 2 to 20 carbon atoms, more preferably an alkylene group having 2 to 10 carbon atoms, and still more preferably an alkylene group having 4 to 8 carbon atoms. Further, the above alkylene group may have a branched chain or a ring structure, but is preferably a straight-chain alkylene group.

[0327] Preferably, the wavy line portions in formula (Ac-1) or formula (Ac-2) are directly bonded to the wavy line portions in the groups represented by the following formula (Ae-1) or formula (Ae-2) respectively independently.

[0328] [Chemical formula 23]

[0329]

[0330] In formula (Ae-1) and formula (Ae-2), R each independently represents acryloyloxy or methacryloyloxy, and the wavy line portion represents the bonding position to the wavy line portions in formula (Ac-1) and formula (Ac-2).

[0331] Moreover, as the compound having a urethane bond, a compound in which a polymerizable group is introduced into a polyurethane obtained by the reaction of a polyisocyanate compound and a polyol compound through a polymer reaction can be used.

[0332] For example, a compound having a urethane bond can be obtained by reacting a compound having an epoxy group and a polymerizable group with a polyurethane oligomer, and the polyurethane oligomer is obtained by reacting a polyol compound having an acid group with a polyisocyanate compound.

[0333] The number of polymerizable groups in the compound having an ester bond as an example of oligomers is preferably 3 or more, and more preferably 6 or more.

[0334] Compounds having epoxy residues as examples of oligomers are preferably compounds containing hydroxyl groups within the compound.

[0335] Moreover, the number of polymerizable groups in the compound having epoxy residues is preferably 2 to 6, more preferably 2 to 3.

[0336] As the above-mentioned compound having epoxy residues, for example, it can be obtained by reacting acrylic acid with a compound having an epoxy group.

[0337] Specific examples of the oligomer are shown below, but the oligomers used in the present invention are not limited thereto.

[0338] As the oligomer, commercially available products can be used, and examples include UA-510H, UA-306H, UA-306I, UA-306T (all manufactured by KYOEISHA CHEMICAL Co., Ltd.), UV-1700B, UV-6300B, UV7620EA (all manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), U-15HA (manufactured by SHIN-NAKAMURA CHEMICAL Co., Ltd.), EBECRYL450, EBECRYL657, EBECRYL885, EBECRYL800, EBECRYL3416, EBECRYL860 (all manufactured by DAICEL-ALLNEX LTD.), etc., but are not limited thereto.

[0339] From the viewpoints of improving chemical resistance, UV printing durability, and suppression of on-machine development residues, the content of the oligomer is preferably 30% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, and further preferably 80% by mass to 100% by mass relative to the total mass of the polymerizable compounds in the image recording layer.

[0340] 《Low Molecular Weight Polymerizable Compounds》

[0341] The polymerizable compound may further contain a polymerizable compound other than the above-mentioned oligomer.

[0342] As the polymerizable compound other than the oligomer, from the viewpoint of chemical resistance, a low molecular weight polymerizable compound is preferred. As the low molecular weight polymerizable compound, it can be in chemical forms such as monomers, dimers, trimers, or mixtures thereof.

[0343] Moreover, as the low molecular weight polymerizable compound, from the viewpoint of chemical resistance, at least one polymerizable compound selected from polymerizable compounds having 3 or more ethylenically unsaturated groups and polymerizable compounds having an isocyanurate ring structure is preferred.

[0344] In the present invention, the low-molecular-weight polymerizable compound refers to a polymerizable compound having a molecular weight of 50 or more and less than 600. Here, in the case where the low-molecular-weight polymerizable compound has a molecular weight distribution, it means the weight-average molecular weight.

[0345] As the molecular weight of the low-molecular-weight polymerizable compound, from the viewpoints of excellent chemical resistance, UV printing durability, and suppression of on-machine development residues, it is preferably 100 or more and less than 600, more preferably 300 or more and less than 600, and further preferably 400 or more and less than 600.

[0346] When the polymerizable compound contains a low-molecular-weight polymerizable compound as a polymerizable compound other than the oligomer (in the case of containing two or more low-molecular-weight polymerizable compounds, it is the total amount thereof), from the viewpoints of chemical resistance, UV printing durability, and suppression of on-machine development residues, the ratio of the oligomer to the low-molecular-weight polymerizable compound (oligomer / low-molecular-weight polymerizable compound) is preferably 10 / 1 to 1 / 10, more preferably 10 / 1 to 3 / 7, and further preferably 10 / 1 to 7 / 3 on a mass basis.

[0347] Moreover, as the low-molecular-weight polymerizable compound, the polymerizable compounds described in paragraphs 0082 to 0086 of International Publication No. 2019 / 013268 can also be preferably used.

[0348] Details of the usage method such as the structure of the polymerizable compound, whether it is used alone or in combination, and the addition amount can be arbitrarily set.

[0349] Among them, from the viewpoint of UV printing durability, the image recording layer preferably contains two or more polymerizable compounds.

[0350] The content of the polymerizable compound (in the case of containing two or more polymerizable compounds, it is the total content of the polymerizable compounds) is preferably 5% by mass to 75% by mass, more preferably 10% by mass to 70% by mass, and further preferably 15% by mass to 60% by mass with respect to the total mass of the image recording layer.

[0351] 〔Color former〕

[0352] The image recording layer in the on-machine development type lithographic printing plate original preferably further contains a color former, and more preferably further contains an acid color former. Moreover, as the color former, a colorless compound is preferably contained.

[0353] The "color former" used in the present invention refers to a compound having the property of changing color or decoloring by stimulation such as light or acid and changing the color of the image recording layer, and the "acid color former" refers to a compound having the property of changing color or decoloring by heating in a state of receiving an electron-withdrawing compound (e.g., a proton such as an acid) and changing the color of the image recording layer. As the acid color former, a colorless compound having partial skeletons such as lactone, lactam, sultone, spiropyran, ester, amide, etc., and rapidly ring-opening or cleaving these partial skeletons when contacting with an electron-withdrawing compound is particularly preferred.

[0354] Examples of such acid color formers include the compounds described in paragraphs 0184 to 0191 of Japanese Patent Laid-Open No. 2019-18412.

[0355] Among them, from the viewpoint of visibility, the color former used in the present invention is preferably at least one compound selected from spiropyran compounds, spirooxazine compounds, spiro lactone compounds, and spiro lactam compounds.

[0356] As the hue of the pigment after coloring, from the viewpoint of visibility, it preferably has a maximum absorption wavelength in the range of 450 to 650 nm. As the color tone, red, purple, blue, or dark green is preferred.

[0357] Furthermore, from the viewpoints of visibility and visibility of the exposed portion, the above acid color former is preferably a colorless pigment.

[0358] As the above colorless pigment, as long as it is a pigment having a colorless structure, there is no particular limitation, but it preferably has a helical structure, and more preferably has a spiro lactone ring structure.

[0359] Furthermore, as the above colorless pigment, from the viewpoints of visibility and visibility of the exposed portion, a colorless pigment having a phthalide structure or a fluorane structure is preferred.

[0360] In addition, from the viewpoints of visibility and visibility of the exposed portion, the above colorless pigment having a phthalide structure or a fluorane structure is preferably a compound represented by any one of the following formulas (Le-1) to (Le-3), and more preferably a compound represented by the following formula (Le-2).

[0361] [Chemical formula 24]

[0362]

[0363] In formulas (Le-1) to (Le-3), ERG each independently represents an electron-donating group, X1 to X4 each independently represent a hydrogen atom, a halogen atom, or a dialkylanilino group, X5 to X 10Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group, Y1 and Y2 each independently represent C or N. When Y1 is N, X1 does not exist. When Y2 is N, X4 does not exist. Ra1 represents a hydrogen atom, an alkyl group or an alkoxy group. Rb1 to Rb4 each independently represent a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group.

[0364] As the electron-donating group in the ERG of formula (Le-1) to formula (Le-3), from the viewpoints of chromogenic property and visual recognition property of the exposed part, it is preferably an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group or an alkyl group. More preferably, it is an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group or an aryloxy group. Further preferably, it is a monoalkylmonoarylamino group, a diarylamino group, a diheteroarylamino group or a monoarylmonoheteroarylamino group. Particularly preferably, it is a monoalkylmonoarylamino group.

[0365] And, as the electron-donating group in the above ERG, from the viewpoints of chromogenic property and visual recognition property of the exposed part, it is preferably a disubstituted amino group having an aryl group with a substituent at at least one ortho position or a heteroaryl group with a substituent at at least one ortho position. More preferably, it is a disubstituted amino group having a phenyl group with a substituent at at least one ortho position and an electron-donating group at the para position. Further preferably, it is an amino group having a phenyl group with a substituent at at least one ortho position and an electron-donating group at the para position and an aryl group or a heteroaryl group. Particularly preferably, it is an amino group having a phenyl group with a substituent at at least one ortho position and an electron-donating group at the para position and an aryl group with an electron-donating group or a heteroaryl group with an electron-donating group.

[0366] In addition, in the present invention, for an aryl group or a heteroaryl group other than a phenyl group, the ortho position means the bonding position adjacent to the above-mentioned 1-position (for example, the 2-position, etc.) when the bonding position of the aryl group or the heteroaryl group to other structures is set as the 1-position.

[0367] Furthermore, as the electron-donating group possessed by the above aryl group or heteroaryl group, from the viewpoints of chromogenic property and visual recognition property of the exposed part, it is preferably an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group or an alkyl group. More preferably, it is an alkoxy group, an aryloxy group, a heteroaryloxy group or an alkyl group. Particularly preferably, it is an alkoxy group.

[0368] From the viewpoints of color-developing property and visual recognition property of the exposed portion, X1 to X4 in formulas (Le-1) to (Le-3) are each independently preferably a hydrogen atom or a chlorine atom, more preferably a hydrogen atom.

[0369] From the viewpoints of color-developing property and visual recognition property of the exposed portion, X5 to X in formula (Le-2) or formula (Le-3) 10 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, a hydroxy group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a heteroaryloxycarbonyl group or a cyano group, more preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group or an aryloxy group, further preferably a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and particularly preferably a hydrogen atom.

[0370] From the viewpoints of color-developing property and visual recognition property of the exposed portion, at least one of Y1 and Y2 in formulas (Le-1) to (Le-3) is preferably C, and more preferably both Y1 and Y2 are C.

[0371] From the viewpoints of color-developing property and visual recognition property of the exposed portion, Ra1 in formulas (Le-1) to (Le-3) is preferably an alkyl group or an alkoxy group, more preferably an alkoxy group, and particularly preferably a methoxy group.

[0372] From the viewpoints of color-developing property and visual recognition property of the exposed portion, Rb1 to Rb4 in formulas (Le-1) to (Le-3) are each independently preferably a hydrogen atom or an alkyl group, more preferably an alkyl group, and particularly preferably a methyl group.

[0373] Furthermore, from the viewpoints of color-developing property and visual recognition property of the exposed portion, the colorless pigment having the above phthalide structure or fluoran structure is more preferably a compound represented by any one of the following formulas (Le-4) to (Le-6), and further preferably a compound represented by the following formula (Le-5).

[0374] [Chemical formula 25]

[0375]

[0376] In formulas (Le-4) to (Le-6), ERG each independently represents an electron-donating group, X1 to X4 each independently represent a hydrogen atom, a halogen atom or a dialkylanilino group, Y1 and Y2 each independently represent C or N, when Y1 is N, X1 does not exist, when Y2 is N, X4 does not exist, Ra1 represents a hydrogen atom, an alkyl group or an alkoxy group, and Rb1 to Rb4 each independently represent a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group.

[0377] In formulas (Le-4) to (Le-6), ERG, X1 to X4, Y1, Y2, Ra1, and Rb1 to Rb4 have the same meanings as ERG, X1 to X4, Y1, Y2, Ra1, and Rb1 to Rb4 in formulas (Le-1) to (Le-3), and the preferred modes are also the same.

[0378] Furthermore, from the viewpoints of color-developing property and visual recognition property of the exposed portion, the above-mentioned colorless dyes having a phthalide structure or a fluoran structure are more preferably compounds represented by any one of the following formulas (Le-7) to (Le-9), and particularly preferably a compound represented by the following formula (Le-8).

[0379] [Chemical formula 26]

[0380]

[0381] In formulas (Le-7) to (Le-9), X1 to X4 each independently represent a hydrogen atom, a halogen atom, or a dialkylanilino group, Y1 and Y2 each independently represent C or N. When Y1 is N, X1 does not exist. When Y2 is N, X4 does not exist. Ra1 to Ra4 each independently represent a hydrogen atom, an alkyl group, or an alkoxy group, Rb1 to Rb4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group, and Rc1 and Rc2 each independently represent an aryl group or a heteroaryl group.

[0382] X1 to X4, Y1, and Y2 in formulas (Le-7) to (Le-9) have the same meanings as X1 to X4, Y1, and Y2 in formulas (Le-1) to (Le-3), and the preferred modes are also the same.

[0383] From the viewpoints of color-developing property and visual recognition property of the exposed portion, Ra1 to Ra4 in formula (Le-7) or formula (Le-9) are each independently preferably an alkyl group or an alkoxy group, more preferably an alkoxy group, and particularly preferably a methoxy group.

[0384] From the viewpoints of color-developing property and visual recognition property of the exposed portion, Rb1 to Rb4 in formulas (Le-7) to (Le-9) are each independently preferably an aryl group substituted with a hydrogen atom, an alkyl group, or an alkoxy group, more preferably an alkyl group, and particularly preferably a methyl group.

[0385] From the viewpoints of color-developing property and visual recognition property of the exposed portion, Rc1 and Rc2 in formula (Le-8) are each independently preferably a phenyl group or an alkylphenyl group, and more preferably a phenyl group.

[0386] Further, from the viewpoints of color-developing property and visual recognition property of the exposed portion, Rc1 and Rc2 in formula (Le-8) are each independently preferably an aryl having a substituent at at least one ortho-position or a heteroaryl having a substituent at at least one ortho-position, more preferably an aryl having a substituent at at least one ortho-position, still more preferably a phenyl having a substituent at at least one ortho-position, and particularly preferably a phenyl having a substituent at at least one ortho-position and an electron-donating group at the para-position. Examples of the above-mentioned substituents in Rc1 and Rc2 include the substituents described below.

[0387] Further, in formula (Le-8), from the viewpoints of color-developing property and visual recognition property of the exposed portion, it is preferred that X1 to X4 are hydrogen atoms and Y1 and Y2 are C.

[0388] In addition, in formula (Le-8), from the viewpoints of color-developing property and visual recognition property of the exposed portion, Rb1 and Rb2 are each independently preferably an aryl substituted with an alkyl or an alkoxy group.

[0389] In addition, in formula (Le-8), from the viewpoints of color-developing property and visual recognition property of the exposed portion, Rb1 and Rb2 are each independently preferably an aryl or a heteroaryl, more preferably an aryl, still more preferably an aryl having an electron-donating group, and particularly preferably a phenyl having an electron-donating group at the para-position.

[0390] Further, as the above-mentioned electron-donating groups in Rb1, Rb2, Rc1 and Rc2, from the viewpoints of color-developing property and visual recognition property of the exposed portion, preferred are an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group or an alkyl group, more preferably an alkoxy group, an aryloxy group, a heteroaryloxy group or an alkyl group, and particularly preferably an alkoxy group.

[0391] Further, as the acid color former, from the viewpoints of color-developing property and visual recognition property of the exposed portion, it is preferred to contain a compound represented by the following formula (Le-10).

[0392] [Chemical formula 27]

[0393]

[0394] In formula (Le-10), Ar1 each independently represents an aryl or a heteroaryl, and Ar2 each independently represents an aryl having a substituent at at least one ortho-position or a heteroaryl having a substituent at at least one ortho-position.

[0395] Ar1 in formula (Le-10) has the same meaning as Rb1 and Rb2 in formulas (Le-7) to (Le-9), and the preferred modes are also the same.

[0396] Ar2 in formula (Le-10) has the same meaning as Rc1 and Rc2 in formulas (Le-7) to (Le-9), and the preferred modes are also the same.

[0397] The alkyl group in formulas (Le-1) to (Le-9) can be linear, branched, or have a ring structure.

[0398] Moreover, the number of carbon atoms of the alkyl group in formulas (Le-1) to (Le-9) is preferably 1 to 20, more preferably 1 to 8, further preferably 1 to 4, and particularly preferably 1 or 2.

[0399] The number of carbon atoms of the aryl group in formulas (Le-1) to (Le-10) is preferably 6 to 20, more preferably 6 to 10, and particularly preferably 6 to 8.

[0400] Specific examples of the aryl group in formulas (Le-1) to (Le-10) include phenyl, naphthyl, anthryl, and phenanthryl, which may have substituents.

[0401] Specific examples of the heteroaryl group in formulas (Le-1) to (Le-10) include furyl, pyridyl, pyrimidinyl, pyrazolyl, and phenylthio group, which may have substituents.

[0402] Furthermore, the monovalent organic groups, alkyl groups, aryl groups, heteroaryl groups, dialkylanilino groups, alkylamino groups, alkoxy groups, etc. in formulas (Le-1) to (Le-10) may have substituents. Examples of the substituents include alkyl groups, aryl groups, heteroaryl groups, halogen atoms, amino groups, alkylamino groups, arylamino groups, heteroaryl amino groups, dialkylamino groups, monoalkylmonoaryl amino groups, monoalkylmonoheteroaryl amino groups, diarylamino groups, diheteroaryl amino groups, monoarylmonoheteroaryl amino groups, hydroxyl groups, alkoxy groups, aryloxy groups, heteroaryloxy groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, heteroaryloxycarbonyl groups, cyano groups, etc. Moreover, these substituents may be further substituted by these substituents.

[0403] As the above-mentioned colorless pigments having a phthalide structure or a fluoran structure that can be preferably used, the following compounds can be cited.

[0404] [Chemical formula 28]

[0405]

[0406] [Chemical formula 29]

[0407]

[0408] [Chemical formula 30]

[0409]

[0410] [Chemical Formula 31]

[0411]

[0412] [Chemical Formula 32]

[0413]

[0414] [Chemical Formula 33]

[0415]

[0416] [Chemical Formula 34]

[0417]

[0418] [Chemical Formula 35]

[0419]

[0420] It is also possible to use commercially available products as the acid chromogenic agent, and examples include ETAC, RED500, RED520, CVL, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, BLUE220, H-3035, BLUE203, ATP, H-1046, H-2114 (manufactured by Fukui Yamada Chemical Co., Ltd. as above), ORANGE-DCF, Vermilion-DCF, PINK-DCF, RED-DCF, BLMB, CVL, GREEN-DCF, TH-107 (manufactured by HODOGAYA CHEMICAL CO., LTD. as above), ODB, ODB-2, ODB-4, ODB-250, ODB-BlackXV, Blue-63, Blue-502, GN-169, GN-2, Green-118, Red-40, Red-8 (manufactured by YAMAMOTO CHEMICALS INC. as above), crystal violet lactone (manufactured by Tokyo Chemical Industry Co., Ltd.), etc. Among these commercial products, the visible light absorption rates of the films formed by 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 good, and thus they are preferred.

[0421] As colorless pigments that can be preferably used, the following compounds can be cited from the viewpoints of visual recognition and visual recognition of the exposed part.

[0422] [Chemical formula 36]

[0423]

[0424] These color formers can be used alone, and two or more components can also be used in combination.

[0425] The content of the color former is preferably 0.5% by mass to 10% by mass, more preferably 1% by mass to 5% by mass, based on the total mass of the image recording layer.

[0426] [Particles]

[0427] From the viewpoints of on-press developability and UV printing durability, the image recording layer in the on-press developable lithographic printing plate original preferably contains particles. The particles can be inorganic particles or organic particles.

[0428] From the viewpoint of on-press developability, the image recording layer preferably contains organic particles, and more preferably contains resin particles.

[0429] As the inorganic particles, known inorganic particles can be used, and metal oxide particles such as silica particles and titanium dioxide particles can be preferably used.

[0430] 《Resin Particles》

[0431] As the resin particles, for example, particles containing an addition polymerization type resin (i.e., addition polymerization type resin particles), particles containing a polyaddition type resin (i.e., polyaddition type resin particles), particles containing a polycondensation type resin (i.e., polycondensation type resin particles), etc. can be cited, but among them, addition polymerization type resin particles or polyaddition type resin particles are preferred.

[0432] Moreover, as the resin particles, from the viewpoint of being able to be heat-fused, they can be particles containing a thermoplastic resin (i.e., thermoplastic resin particles).

[0433] Moreover, the resin particles can be in the form of microcapsules, microgels (i.e., crosslinked resin particles), etc.

[0434] As the resin particles, they are preferably selected from thermoplastic resin particles, thermoreactive resin particles, resin particles having a polymerizable group, microcapsules containing a hydrophobic compound, and microgels (crosslinked resin particles). Among them, resin particles having a polymerizable group are preferred.

[0435] In a particularly preferred embodiment, the resin particles contain at least one ethylenically unsaturated group. Due to the presence of such resin particles, an effect of improving the printing durability of the exposed portion and the on-machine developability of the unexposed portion can be obtained.

[0436] As the thermoplastic resin particles, those described in Research Disclosure No. 33303 in January 1992, Japanese Patent Laid-Open No. 9-123387, Japanese Patent Laid-Open No. 9-131850, Japanese Patent Laid-Open No. 9-171249, Japanese Patent Laid-Open No. 9-171250, European Patent No. 931647 specification, etc. are preferred.

[0437] Specific examples of the resin constituting the thermoplastic resin particles include homopolymers or copolymers of monomers such as ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, acrylates or methacrylates having a polyalkylene structure, or mixtures thereof.

[0438] As the thermoplastic resin particles, from the viewpoints of ink inkability and UV printing durability, resins containing a structural unit formed from an aromatic vinyl compound and a structural unit having a nitrile group are preferred.

[0439] As the above-mentioned aromatic vinyl compound, any compound having a structure in which a vinyl group is bonded to an aromatic ring may be used, and examples thereof include styrene compounds and vinylnaphthalene compounds. Styrene compounds are preferred, and styrene is more preferred.

[0440] As the styrene compound, styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p-methoxy-β-methylstyrene, etc. can be cited, and styrene can be preferably selected.

[0441] From the viewpoint of ink inkability, the content of the structural unit formed from an aromatic vinyl compound is preferably more than the content of the structural unit having a nitrile group described later, and is more preferably 15% by mass to 85% by mass, and further preferably 30% by mass to 70% by mass relative to the total mass of the resin.

[0442] The structural unit having a nitrile group is preferably introduced using a monomer having a nitrile group.

[0443] As the monomer having a nitrile group, acrylonitrile compounds can be cited, and (meth)acrylonitrile can be preferably selected.

[0444] As the structural unit having a nitrile group, a structural unit formed from (meth)acrylonitrile is preferred.

[0445] From the viewpoint of ink receptivity, the content of the structural unit having a nitrile group is preferably less than the content of the structural unit formed from the above-mentioned aromatic vinyl compound, and more preferably 55% by mass to 90% by mass, still more preferably 60% by mass to 85% by mass, based on the total mass of the resin.

[0446] Moreover, when the resin contained in the thermoplastic resin particles contains a structural unit formed from an aromatic vinyl compound and a structural unit having a nitrile group, the content ratio (structural unit formed from an aromatic vinyl compound: structural unit having a nitrile group) of the structural unit formed from an aromatic vinyl compound and the structural unit having a nitrile group is preferably 5:5 to 9:1, more preferably 6:4 to 8:2, on a mass basis.

[0447] From the viewpoints of UV printing durability and chemical resistance, the resin contained in the thermoplastic resin particles preferably further has a structural unit formed from an N-vinyl heterocyclic compound.

[0448] Examples of the N-vinyl heterocyclic compound include N-vinylpyrrolidone, N-vinylcarbazole, N-vinylpyrrole, N-vinylphenothiazine, N-vinylsuccinimide, N-vinylphthalimide, N-vinylcaprolactam, and N-vinylimidazole, and N-vinylpyrrolidone is preferred.

[0449] The content of the structural unit formed from an N-vinyl heterocyclic compound is preferably 5% by mass to 50% by mass, more preferably 10% by mass to 40% by mass, based on the total mass of the thermoplastic resin.

[0450] The resin contained in the thermoplastic resin particles may contain a structural unit having an acidic group, but from the viewpoints of on-machine developability and ink receptivity, it is preferably free of a structural unit having an acidic group.

[0451] Specifically, the content of the structural unit having an acidic group in the thermoplastic resin is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less. The lower limit of the above content is not particularly limited and may be 0% by mass.

[0452] Moreover, the acid value of the thermoplastic resin is preferably 160 mgKOH / g or less, more preferably 80 mgKOH / g or less, still more preferably 40 mgKOH / g or less. The lower limit of the acid value is not particularly limited and may be 0 mgKOH / g.

[0453] In the present invention, the acid value is determined by a method in accordance with JIS K0070:1992.

[0454] From the viewpoint of ink receptivity, the resin contained in the thermoplastic resin particles may contain a structural unit containing a hydrophobic group.

[0455] Examples of the hydrophobic group include an alkyl group, an aryl group, an aralkyl group, etc.

[0456] As the structural unit containing a hydrophobic group, a structural unit formed from an alkyl (meth)acrylate compound, an aryl (meth)acrylate compound, or an aralkyl (meth)acrylate compound is preferred, and a structural unit formed from an alkyl (meth)acrylate compound is more preferred.

[0457] The content of the structural unit having a hydrophobic group in the resin contained in the thermoplastic resin particles is preferably 5% by mass to 50% by mass, more preferably 10% by mass to 30% by mass, relative to the total mass of the resin.

[0458] From the viewpoints of UV printing durability and on-machine developability, the thermoplastic resin contained in the thermoplastic resin particles preferably has a hydrophilic group.

[0459] As the hydrophilic group, if it has a hydrophilic structure, there is no particular limitation, but examples include acid groups such as a carboxyl group, a hydroxyl group, an amino group, a nitrile group, a polyalkylene oxide structure, etc.

[0460] As the hydrophilic group, from the viewpoints of UV printing durability and on-machine developability, a group having a polyalkylene oxide structure, a group having a polyester structure, or a sulfonic acid group is preferred, a group having a polyalkylene oxide structure or a sulfonic acid group is more preferred, and a group having a polyalkylene oxide structure is further preferred.

[0461] As the polyalkylene oxide structure, from the viewpoint of on-machine developability, a polyethylene oxide structure, a polypropylene oxide structure, or a poly(ethylene oxide / propylene oxide) structure is preferred.

[0462] Furthermore, from the viewpoint of on-machine developability, among the above hydrophilic groups, as the polyalkylene oxide structure, a polypropylene oxide structure is preferred, and a polyethylene oxide structure and a polypropylene oxide structure are more preferred.

[0463] From the viewpoint of on-machine developability, the number of alkylene oxide structures in the polyalkylene oxide structure is preferably 2 or more, more preferably 5 or more, further preferably 5 to 200, and particularly preferably 8 to 150.

[0464] Furthermore, from the viewpoint of on-machine developability, as the hydrophilic group, a group represented by the following formula Z is preferred.

[0465] Among the hydrophilic groups possessed by the thermoplastic resin, a group represented by the following formula P0 is preferred.

[0466] [Chemical Formula 37]

[0467]

[0468] In formula P0, L P each independently represents an alkylene group, and R P represents a hydrogen atom or an alkyl group, and n represents an integer of 1 to 100.

[0469] In formula P0, L P are each independently preferably an ethylene group, 1-methylethylene group or 2-methylethylene group, and more preferably an ethylene group.

[0470] In formula P0, R P is preferably a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, further preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.

[0471] In formula P0, n is preferably an integer of 1 to 10, and more preferably an integer of 1 to 4.

[0472] The content of the structural unit having a hydrophilic group is preferably 5% by mass to 60% by mass, and more preferably 10% by mass to 30% by mass, relative to the total mass of the resin.

[0473] The resin contained in the thermoplastic resin particles may further contain other structural units. As the other structural units, structural units other than the above-described respective structural units can be contained without particular limitation. For example, structural units formed from acrylamide compounds, vinyl ether compounds, etc. can be cited.

[0474] The content of the other structural units in the resin contained in the thermoplastic resin particles is preferably 5% by mass to 50% by mass, and more preferably 10% by mass to 30% by mass, relative to the total mass of the resin.

[0475] As the thermoreactive resin particles, resin particles having a thermoreactive group can be cited. The thermoreactive resin particles form a hydrophobized region through crosslinking based on a thermal reaction and a change in functional groups during crosslinking.

[0476] As the heat-reactive group in the resin particles having a heat-reactive group, as long as it can form a chemical bond, it can be a functional group that undergoes any reaction, but is preferably a polymerizable group. As examples thereof, alkenyl unsaturated groups (e.g., acryloyl, methacryloyl, vinyl, allyl, etc.) that undergo radical polymerization reactions, cationic polymerizable groups (e.g., vinyl, vinyloxy, epoxy group, oxetanyl, etc.), isocyanate groups or their block products that undergo addition reactions, epoxy groups, vinyloxy groups, and functional groups having active hydrogen atoms as reaction targets thereof (e.g., amino group, hydroxyl group, carboxyl group, etc.), carboxyl groups that undergo condensation reactions, and hydroxyl groups or amino groups as reaction targets, acid anhydrides that undergo ring-opening addition reactions, and amino groups or hydroxyl groups as reaction targets, etc. can be preferably selected.

[0477] As the resin having the above heat-reactive group, it can be an addition polymerization type resin, an addition polymerization type resin or a condensation polymerization type resin, or a thermoplastic resin.

[0478] As the microcapsule, for example, microcapsules containing at least a part of the constituent components (preferably a hydrophobic compound) of the image recording layer as described in JP-A-2001-277740 and JP-A-2001-277742 are preferred. A preferred mode of the image recording layer containing microcapsules as resin particles is a structure in which the hydrophobic component (i.e., hydrophobic compound) in the constituent components of the image recording layer is contained in the microcapsules, and the hydrophilic component (i.e., hydrophilic compound) is contained outside the microcapsules.

[0479] The microgel (crosslinked resin particles) can contain a part of the constituent components of the image recording layer in at least one of its surface and interior. In particular, from the viewpoints of the sensitivity of the original lithographic printing plate and the printing durability of the obtained lithographic printing plate, a reactive microgel having a polymerizable group on its surface is preferred.

[0480] In order to obtain microcapsules containing the constituent components of the image recording layer, known synthesis methods can be applied.

[0481] The microgel (crosslinked resin particles) can contain a part of the constituent components of the image recording layer in at least one of its surface and interior. In particular, from the viewpoints of the sensitivity of the original lithographic printing plate and the printing durability of the obtained lithographic printing plate, a reactive microgel having a polymerizable group on its surface is preferred.

[0482] In order to obtain microgels containing the constituent components of the image recording layer, known synthesis methods can be applied.

[0483] As the resin particles, from the viewpoints of the printing durability, stain resistance, and storage stability of the obtained lithographic printing plate, polyaddition resin particles obtained by the reaction of a polyisocyanate compound, which is an adduct of a polyphenol compound having two or more hydroxyl groups in the molecule and isophorone diisocyanate, and a compound having an active hydrogen are preferred.

[0484] As the above-mentioned polyphenol compound, a compound having a plurality of benzene rings having phenolic hydroxyl groups is preferred.

[0485] As the compound having the above-mentioned active hydrogen, a polyol compound or a polyamine compound is preferred, a polyol compound is more preferred, and at least one compound selected from propylene glycol, glycerin, and trimethylolpropane is further preferred. Further, water can be used as the above-mentioned active hydrogen compound. In the case of using water, the amine generated by the reaction of the isocyanate group and water can form a urethane bond to form particles.

[0486] As the particles of the resin obtained by the reaction of a polyisocyanate compound, which is an adduct of a polyphenol compound having two or more hydroxyl groups in the molecule and isophorone diisocyanate, and a compound having an active hydrogen, the resin particles described in paragraphs 0230 to 0234 of International Publication No. 2018 / 043259 can be preferably cited.

[0487] In addition, as the resin particles, from the viewpoints of the printing durability and solvent resistance of the obtained lithographic printing plate, addition polymerization type resin particles having a hydrophobic main chain and containing both i) a structural unit having a nitrile group directly bonded to the above-mentioned hydrophobic main chain and ii) a structural unit having a side group containing a hydrophilic polyalkylene oxide chain segment are preferred. Specifically, the particles described in paragraph 0156 of Japanese Patent Application Laid-Open No. 2019-64269 are preferred.

[0488] 《Group represented by formula Z》

[0489] The resin particles in the present invention preferably have a group represented by the following formula Z as a hydrophilic group.

[0490] *-Q-W-Y Formula Z

[0491] 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, Y represents a monovalent group having a hydrophilic structure or a monovalent group having a hydrophobic structure, any one of W and Y has a hydrophilic structure, and * represents a bonding site with other structures.

[0492] Further, it is preferred that all the hydrophilic structures contained in formula Z contain a polyalkylene oxide structure.

[0493] In the above formula Z, Q is preferably a divalent linking group having 1 to 20 carbon atoms, more preferably a divalent linking group having 1 to 10 carbon atoms.

[0494] Moreover, in the above formula Z, Q is preferably an alkylene group, an arylene group, an ester bond, an amide bond, or a group formed by combining two or more of them, more preferably a phenylene group, an ester bond, or an amide bond.

[0495] The divalent group having a hydrophilic structure in W of the above formula Z is preferably a group containing a polyalkylene oxide structure, preferably a polyalkyleneoxy group or a group in which -CH2CH2NR W - is bonded to one end of the polyalkyleneoxy group. In addition, R W represents a hydrogen atom or an alkyl group.

[0496] The divalent group having a hydrophobic structure in W of the above formula Z is preferably -R WA -, -O-R WA -O-, -R W N-R WA -NR W -, -OC(=O)-R WA -O- or -OC(=O)-R WA -O-. In addition, R WA each independently represents a linear, branched or cyclic alkylene group having 6 to 120 carbon atoms, a haloalkylene group having 6 to 120 carbon atoms, an arylene group having 6 to 120 carbon atoms, an alkarylene group (a divalent group obtained by removing one hydrogen atom from an alkylaryl group) having 6 to 120 carbon atoms, or an aralkyl group having 6 to 120 carbon atoms.

[0497] The monovalent group having a hydrophilic structure in Y of the above formula Z is preferably -OH, -C(=O)OH, a polyalkyleneoxy group having a hydrogen atom or an alkyl group at the end, or a group in which -CH2CH2N(R W )- is bonded to the other end of a polyalkyleneoxy group having a hydrogen atom or an alkyl group at the end. Among them, as the monovalent group having a hydrophilic structure, a group containing a polyalkylene oxide structure is preferred, and a polyalkyleneoxy group having a hydrogen atom or an alkyl group at the end or a group in which -CH2CH2N(R W )- is bonded to the other end of a polyalkyleneoxy group having a hydrogen atom or an alkyl group at the end is preferred.

[0498] The monovalent group having a hydrophobic structure in Y of the above formula Z is preferably 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, an alkaryl 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 . R WB represents an alkyl group having 6 to 20 carbon atoms.

[0499] Among the resin particles having the group represented by the above formula Z, from the viewpoints of printing durability, ink receptivity, and on-machine developability, it is more preferable that W is a divalent group having a hydrophilic structure, 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 terminal.

[0500] In addition, the group represented by the formula Z can function as a dispersing group for improving the dispersibility of the resin particles.

[0501] From the viewpoints of printing durability and on-machine developability, the resin particles in the present invention preferably have a polymerizable group (preferably an ethylenically unsaturated group), and more preferably include resin particles having a polymerizable group especially on the surface. By using resin particles having a polymerizable group, the printing durability (preferably UV printing durability) can be improved.

[0502] From the viewpoint of printing durability, the resin particles in the present invention are preferably resin particles having a hydrophilic group and a polymerizable group.

[0503] The above polymerizable group may be a cationic polymerizable group or a radical polymerizable group, but from the viewpoint of reactivity, a radical polymerizable group is preferred.

[0504] As the above polymerizable group, as long as it is a group capable of polymerization, there is no particular limitation. From the viewpoint of reactivity, an ethylenically unsaturated group is preferred, a vinylphenyl group (styryl group), a (meth)acryloyloxy group, or a (meth)acrylamide group is more preferred, and a (meth)acryloyloxy group is particularly preferred.

[0505] Furthermore, the resin constituting the resin particles having a polymerizable group preferably has a structural unit having a polymerizable group.

[0506] In addition, a polymerizable group can be introduced onto the surface of the resin particles by a polymer reaction.

[0507] Also, from the viewpoints of printing durability, ink receptivity, on-machine developability, and suppression of development residues during on-machine development, the resin particles preferably contain an addition-type resin having a urea bond, more preferably contain an addition-type resin having a structure obtained by reacting at least the isocyanate compound represented by the following formula (Iso) with water, and particularly preferably contain an addition-type resin having a structure obtained by reacting at least the isocyanate compound represented by the following formula (Iso) with water and having a poly(ethylene oxide) structure and a poly(propylene oxide) structure as a poly(oxyalkylene) structure. Further, the particles containing the addition-type resin having the above urea bond are preferably microgels.

[0508] [Chemical Formula 38]

[0509]

[0510] In formula (Iso), n represents an integer of 0 to 10.

[0511] As an example of the reaction of the isocyanate compound represented by the above formula (Iso) with water, the reaction shown below can be cited. Further, the following example is an example where n = 0 and the 4,4-isomer is used.

[0512] As shown below, when the isocyanate compound represented by the above formula (Iso) is reacted with water, a part of the water isocyanate group is hydrolyzed to generate an amino group, and the generated amino group reacts with the isocyanate group to form a urea bond and form a dimer. Further, the following reaction is repeated to form an addition-type resin having a urea bond.

[0513] Further, in the following reaction, a compound having reactivity with an isocyanate group (a compound having an active hydrogen), such as an alcohol compound or an amine compound, is added, whereby the structures of the alcohol compound, the amine compound, etc. can also be introduced into the addition-type resin having a urea bond.

[0514] As the compound having the above active hydrogen, a compound having the above-described active hydrogen can be preferably cited.

[0515] [Chemical Formula 39]

[0516]

[0517] Also, the addition-type resin having the above urea bond preferably has an ethylenically unsaturated group, and more preferably has a group represented by the following formula (PETA).

[0518] [Chemical Formula 40]

[0519]

[0520] In formula (PETA), the wavy line part represents the bonding position with other structures.

[0521] "Synthesis of Resin Particles"

[0522] As a method for synthesizing resin particles, there is no particular limitation as long as it is a method capable of synthesizing particles using the various resins described above. As a method for synthesizing resin particles, for example, known methods for synthesizing resin particles such as emulsion polymerization method, suspension polymerization method, dispersion polymerization method, soap-free polymerization method, and microemulsion polymerization method can be cited.

[0523] In addition, in the synthesis of resin particles, known methods for synthesizing microcapsules and microgels (crosslinked resin particles) can be used.

[0524] "Average Particle Size of Particles"

[0525] The average particle size of the particles is preferably 0.01 μm to 3.0 μm, more preferably 0.03 μm to 2.0 μm, and still more preferably 0.10 μm to 1.0 μm. Good resolution and stability over time can be obtained within this range.

[0526] Regarding the average particle size of the particles, it is measured by a light scattering method or an electron micrograph of the particles is taken, and the particle sizes of a total of 5,000 particles are measured on the photograph and the average value is calculated. In addition, for non-spherical particles, it is set as the circular equivalent diameter of the particles on the photograph.

[0527] In addition, regarding the average particle size of the particles in the present invention, unless otherwise specified, it is the volume average particle size.

[0528] The particles (preferably resin particles) can be used alone or two or more kinds can be used simultaneously.

[0529] From the viewpoints of developability and printing durability, the content of the particles (preferably resin particles) relative to the total mass of the image recording layer is preferably 5% by mass to 90% by mass, more preferably 10% by mass to 90% by mass, still more preferably 20% by mass to 90% by mass, and particularly preferably 50% by mass to 90% by mass.

[0530] 〔Other Components〕

[0531] The image recording layer in the original plate for on-machine developing lithographic printing plate may also contain other components in addition to the components described above.

[0532] Examples of other components include binder polymers, color formers, chain transfer agents, low-molecular-weight hydrophilic compounds, sensitizers, and other additives.

[0533] Examples of other components include colorants, printing agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic particles, and low-molecular-weight hydrophilic compounds, etc. disclosed in paragraphs 0181 to 0190 of JP-A-2009-255434.

[0534] In addition, examples of other compounds include hydrophobization precursors (fine particles capable of converting an image recording layer into a hydrophobic state when heated), low-molecular-weight hydrophilic compounds, sensitizers (e.g., phosphonium compounds, nitrogen-containing low-molecular-weight compounds, ammonium group-containing polymers), and chain transfer agents disclosed in paragraphs 0191 to 0217 of JP-A-2012-187907.

[0535] -Binder polymer-

[0536] If necessary, the image recording layer may contain a binder polymer.

[0537] Here, the binder polymer refers to a polymer other than resin particles, that is, a polymer that is not in particle form.

[0538] In addition, with respect to the binder polymer, ammonium salt-containing polymers in the fat sensitizer and polymers used as surfactants are excluded.

[0539] As the binder polymer, a known binder polymer (e.g., (meth)acrylic resin, polyvinyl acetal, polyurethane resin, etc.) used in the image recording layer of a lithographic printing plate precursor can be preferably used.

[0540] As an example, the binder polymer used in an on-machine developable lithographic printing plate precursor (hereinafter, also referred to as an on-machine development binder polymer) will be described in detail.

[0541] As the on-machine development binder polymer, a binder polymer having an alkylene oxide chain is preferred. Regarding the binder polymer having an alkylene oxide chain, a poly(alkylene oxide) moiety may be present in the main chain or in the side chain. Further, it may be a graft polymer having poly(alkylene oxide) in the side chain, or a block copolymer composed of a block containing repeating units of poly(alkylene oxide) and a block containing repeating units not containing (alkylene oxide).

[0542] When a poly(alkylene oxide) moiety is present in the main chain, a polyurethane resin is preferred.

[0543] As polymers for the main chain when having a poly(alkylene oxide) moiety in the side chain, examples include (meth)acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, polystyrene resins, novolak-type phenolic resins, polyester resins, synthetic rubbers, and natural rubbers, and (meth)acrylic resins are particularly preferred.

[0544] Moreover, as other preferred examples of the binder polymer, there can be mentioned a high molecular compound having a polyfunctional thiol of 6 to 10 functional groups as the core part and having a polymer chain bonded to the core part through a thioether bond, and the above polymer chain having a polymerizable group (hereinafter, also referred to as a star-shaped high molecular compound).

[0545] As the star-shaped high molecular compound, for example, the compound described in JP-A-2012-148555 can be preferably used.

[0546] Regarding the star-shaped high molecular compound, there can be mentioned a compound having a polymerizable group such as an ethylenically unsaturated bond described in JP-A-2008-195018 for improving the film strength of the image part on the main chain or side chain, and a compound having the polymerizable group on the side chain is preferred. Crosslinking is formed between the molecules of the star-shaped high molecular compound by the polymerizable group possessed by the star-shaped high molecular compound, and curing is promoted.

[0547] As the polymerizable group, ethylenically unsaturated groups such as (meth)acryloyl group, vinyl group, allyl group, vinylphenyl (styryl) group, epoxy group, etc. are preferred, and from the viewpoint of polymerization reactivity, (meth)acryloyl group, vinyl group, vinylphenyl (styryl) group are more preferred, and (meth)acryloyl group is particularly preferred. These groups can be introduced into the polymer by a polymer reaction or copolymerization. Specifically, for example, the reaction of a polymer having a carboxyl group on the side chain with glycidyl methacrylate, or the reaction of a polymer having an epoxy group with a carboxylic acid having an ethylenically unsaturated group such as methacrylic acid can be utilized.

[0548] Regarding the molecular weight of the binder polymer, as a polystyrene conversion value based on the GPC method, the weight average molecular weight (Mw) is preferably 2,000 or more, more preferably 5,000 or more, and further preferably 10,000 to 300,000.

[0549] As the binder polymer, if necessary, hydrophilic polymers such as polyacrylic acid, polyvinyl alcohol, and polyvinyl acetal described in JP-A-2008-195018 can be used simultaneously. Moreover, an oleophilic polymer and a hydrophilic polymer can also be used simultaneously.

[0550] Among them, from the viewpoint of developability on the slave machine, the image recording layer preferably contains polyvinyl acetal. As the polyvinyl acetal, for example, polyvinyl butyral etc. can be preferably selected.

[0551] The binder polymer can be used alone in one kind, or two or more kinds can be used simultaneously.

[0552] The binder polymer can be contained in the image recording layer in any amount, but the content of the binder polymer relative to the total mass of the image recording layer is preferably 1% by mass to 90% by mass, more preferably 5% by mass to 80% by mass.

[0553] 〔Formation of image recording layer〕

[0554] The image recording layer in the lithographic printing plate original according to the present invention can be formed, for example, in the following manner: as described in paragraphs 0142 to 0143 of Japanese Unexamined Patent Application Publication No. 2008-195018, each of the above necessary components is dispersed or dissolved in a known solvent to prepare a coating solution, and the coating solution is coated on a support by a known method such as bar coating and dried. The coating amount (solid content) of the image recording layer after coating and drying varies depending on the use, but is preferably 0.3 g / m 2 ~3.0 g / m 2 . Within this range, good sensitivity and good film properties of the image recording layer can be obtained.

[0555] As the solvent, known solvents can be used. Specifically, for example, water, acetone, methyl ethyl ketone (2-butanone), cyclohexane, ethyl acetate, dichloroethane, 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 monoethyl 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-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, methyl lactate, ethyl lactate, etc. The solvents can be used alone in one kind, or two or more kinds can be used simultaneously. The solid content concentration in the coating solution is preferably 1% by mass to 50% by mass.

[0556] The coating amount (solid content) of the image recording layer after coating and drying varies depending on the use, but from the viewpoint of obtaining good sensitivity and good film properties of the image recording layer, it is preferably 0.3 g / m 2 ~3.0 g / m 2 .

[0557] Moreover, the film thickness of the image recording layer in the original planographic printing plate according to the present invention is preferably from 0.1 μm to 3.0 μm, more preferably from 0.3 μm to 2.0 μm.

[0558] In the present invention, the film thickness of each layer in the original planographic printing plate is confirmed by preparing a section cut along a direction perpendicular to the surface of the original planographic printing plate and observing the cross-section of the section by a scanning microscope (SEM).

[0559] <Outermost layer>

[0560] The original planographic printing plate according to the present invention preferably has an outermost layer on the image recording layer.

[0561] Moreover, the outermost layer is the outermost layer on the image recording layer side in the support of the original planographic printing plate.

[0562] In addition to the function of suppressing the image formation hindering reaction by oxygen barrier, the outermost layer may also have functions such as preventing scratches from occurring in the image recording layer and preventing ablation during high-intensity laser exposure.

[0563] The outermost layer is also referred to as a protective layer.

[0564] -Water-soluble polymer-

[0565] From the viewpoint of developability for removal (more preferably developability on a printing press), the outermost layer preferably contains a water-soluble polymer.

[0566] In the present invention, the water-soluble polymer refers to a polymer that dissolves 1 g or more in 100 g of pure water at 70 °C and does not precipitate even when the solution obtained by dissolving 1 g of the polymer in 100 g of pure water at 70 °C is cooled to 25 °C.

[0567] Examples of the water-soluble polymer used in the outermost layer include polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, water-soluble cellulose derivatives, polyethylene glycol, poly(meth)acrylonitrile, and the like.

[0568] As the modified polyvinyl alcohol, acid-modified polyvinyl alcohol having a carboxyl group or a sulfo group is preferably used. Specifically, examples include the modified polyvinyl alcohols described in JP-A-2005-250216 and JP-A-2006-259137.

[0569] As the above water-soluble polymer, polyvinyl alcohol can be cited as a preferred example. Among them, as the water-soluble polymer, polyvinyl alcohol having a saponification degree of 50% or more is more preferably used.

[0570] The saponification degree described above is preferably 60% or more, more preferably 70% or more, and further preferably 85% or more. The upper limit of the saponification degree is not particularly limited and may be 100% or less.

[0571] The saponification degree described above can be measured according to the method described in JIS K 6726:1994.

[0572] As the water-soluble polymer described above, polyvinylpyrrolidone can be cited as a preferred example.

[0573] As the water-soluble polymer, it is also preferable to use polyvinyl alcohol and polyvinylpyrrolidone in combination.

[0574] The water-soluble polymer can be used alone as one kind, or two or more kinds can be used in combination.

[0575] When the outermost layer contains a water-soluble polymer, the content of the water-soluble polymer is preferably 1% by mass to 99% by mass, more preferably 3% by mass to 97% by mass, and further preferably 5% by mass to 95% by mass with respect to the total mass of the outermost layer.

[0576] The outermost layer can contain an inorganic layered compound to improve the oxygen barrier property.

[0577] The inorganic layered compound is particles having a thin plate-like shape, and examples thereof include mica groups such as natural mica and synthetic mica, talc represented by the formula: 3MgO·4SiO·H2O, phlogopite, montmorillonite, soapstone, hectorite, zirconium phosphate, etc.

[0578] The inorganic layered compound that can be preferably used is a mica compound. As the mica compound, for example, it can be cited as represented by the formula: A(B,C) 2-5 D4O 10 (OH,F,O)2 [wherein, A is any one of K, Na, and Ca, B and C are any one of Fe(II), Fe(III), Mn, Al, Mg, and V, and D is Si or Al.] represents mica groups such as natural mica and synthetic mica.

[0579] In the mica group, as natural mica, muscovite, paragonite, phlogopite, biotite, and scaly mica can be cited. As synthetic mica, for example, fluorophlogopite KMg3(AlSi3O 10 )F2, potassium tetrasilicic mica KMg 2.5 (Si4O 10 )F2 and other non-swelling micas and Na tetrafuorosilicate mica NaMg 2.5 (Si4O 10 )F2, Na or Li phlogopite (Na,Li)Mg2Li(Si4O 10)F2, montmorillonite-based Na or Li hectorite (Na, Li) 1 / 8 Mg 2 / 5 Li 1 / 8 (Si4O 10 )F2 and swelling micas such as etc. In addition, synthetic clay is also useful.

[0580] Among the above mica compounds, fluorine-based swelling micas are particularly useful. That is, swelling synthetic mica has a stacked structure including unit lattice layers with a thickness of about The substitution of metal atoms in the lattice is significantly higher than that of other clay minerals. As a result, there is a shortage of positive charges in the lattice layer. To compensate for the shortage of positive charges, Li + , Na + , Ca 2+ , Mg 2+ and other cations are adsorbed between the layers. These cations between the layers are called exchangeable cations and can be exchanged with various cations. In particular, when the cations between the layers are Li + , Na + , the ionic radius is small, so the bonding between the layered lattices is weak and it swells greatly through water. When a shear force is applied in the swollen state, it is easy to split and form a stable sol in water. This tendency of swelling synthetic mica is strong and it is particularly preferably used.

[0581] As the shape of the mica compound, from the viewpoint of controlling diffusion, the thinner the thickness, the better. As long as it does not hinder the smoothness of the coating surface or the transmission of activated light, the larger the planar size, the better. Therefore, the aspect ratio is preferably 20 or more, more preferably 100 or more, and particularly preferably 200 or more. The aspect ratio is the ratio of the major axis to the thickness of the particle and can be measured, for example, based on the projection diagram of the micrograph of the particle.

[0582] The larger the aspect ratio of the mica compound, the greater the oxygen barrier effect obtained.

[0583] Regarding the particle size of the mica compound, its average major axis 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 particle 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 swelling synthetic mica as a representative compound, as a preferred mode, the thickness is 1 nm to 50 nm and the planar size (major axis) is about 1 μm to 20 μm.

[0584] 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, relative to the total solid content of the outer coating. Even when multiple inorganic layered compounds are used simultaneously, the total content of the inorganic layered compounds is preferably within the above range.

[0585] Within the above range, the oxygen barrier property is improved, and good sensitivity can be obtained. Moreover, a decrease in ink adhesion can be prevented.

[0586] - Other components -

[0587] The outermost layer described above may also contain other components such as a hydrophobic polymer, a color-changing compound, an acid generator, and an additive.

[0588] Hereinafter, other components will be described.

[0589] · Hydrophobic polymer

[0590] The outermost layer preferably contains a hydrophobic polymer.

[0591] A hydrophobic polymer refers to a polymer that dissolves less than 1 g or does not dissolve in 100 g of pure water at 70 °C.

[0592] Examples of the hydrophobic polymer include polyethylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, poly(alkyl methacrylate) (e.g., poly(methyl methacrylate), poly(ethyl methacrylate), poly(butyl methacrylate), etc.), and copolymers formed by combining the raw material monomers of these polymers.

[0593] Moreover, as the hydrophobic polymer, a polyvinylidene chloride resin is preferably included.

[0594] In addition, as the hydrophobic polymer, a styrene-acrylic copolymer is preferably included.

[0595] Furthermore, from the viewpoint of on-machine developability, the hydrophobic polymer is preferably hydrophobic polymer particles.

[0596] The hydrophobic polymer may be used alone or in combination of two or more.

[0597] When the outermost layer contains a hydrophobic polymer, the content of the hydrophobic polymer is preferably 1% by mass to 80% by mass, more preferably 5% by mass to 50% by mass, relative to the total mass of the outermost layer.

[0598] · Color-changing compound

[0599] The outermost layer may also contain a color-changing compound.

[0600] In the present invention, a "color-changing compound" refers to a compound whose absorption in the visible light region (wavelength: 400 nm or more and less than 750 nm) changes due to infrared exposure. That is, in the present invention, "color change" refers to a change in absorption in the visible light region (wavelength: 400 nm or more and less than 750 nm) due to infrared exposure.

[0601] Specifically, examples of the color-changing compound in the present invention include (1) a compound whose absorption in the visible light region increases due to infrared exposure compared to before the infrared exposure, (2) a compound that has absorption in the visible light region due to infrared exposure, and (3) a compound that does not have absorption in the visible light region due to infrared exposure.

[0602] In addition, the infrared rays in the present invention are light rays having a wavelength of 750 nm to 1 mm, preferably light rays having a wavelength of 750 nm to 1,400 nm.

[0603] As the color-changing compound, a compound that develops color due to infrared exposure is preferably included.

[0604] Furthermore, as the color-changing compound, a decomposable compound that decomposes due to infrared exposure is preferably included, and among them, a decomposable compound that decomposes by heat, electron transfer, or both caused by infrared exposure is preferably included.

[0605] More specifically, the color-changing compound in the present invention is preferably a compound that decomposes due to infrared exposure (more preferably decomposes by heat, electron transfer, or both caused by infrared exposure), and whose absorption in the visible light region increases or the absorption is shifted to a shorter wavelength and has absorption in the visible light region compared to before the infrared exposure.

[0606] Here, "decomposition by electron transfer" means that electrons excited from the HOMO (highest occupied molecular orbital) of the color-changing compound to the LUMO (lowest unoccupied molecular orbital) by infrared exposure transfer within the molecule to an electron-accepting group within the molecule (a group with a potential close to the LUMO), and decomposition then occurs.

[0607] Hereinafter, a decomposable compound as an example of the color-changing compound will be described.

[0608] Regarding the decomposable compound, any compound that absorbs at least a part of the light in the infrared wavelength region (wavelength region of 750 nm to 1 mm, preferably wavelength region of 750 nm to 1,400 nm) and decomposes may be used, but a compound having a maximum absorption wavelength in the wavelength region of 750 nm to 1,400 nm is preferred.

[0609] More specifically, the decomposable compound is preferably a compound that decomposes upon infrared exposure and generates a compound having a maximum absorption wavelength in the wavelength region of 500 nm to 600 nm.

[0610] From the viewpoint of improving the visual recognition of the exposed portion, the decomposable compound is preferably a cyanine having a group that decomposes upon infrared exposure.

[0611] As the cyanine serving as the decomposable compound, the infrared absorbing compound described in International Publication No. 2019 / 219560 can be preferably used.

[0612] Moreover, the above-mentioned color-changing compound may contain an acid chromogenic agent.

[0613] As the acid chromogenic agent, the acid chromogenic agent described as the acid chromogenic agent in the image recording layer can be used, and the preferred manner is the same.

[0614] The color-changing compound can be used alone or in combination of two or more components.

[0615] As the color-changing compound, the decomposable compound described above and the acid generator described later can be used in combination.

[0616] From the viewpoint of visual recognition, the content of the color-changing compound in the outermost layer is preferably 0.10% by mass to 50% by mass, more preferably 0.50% by mass to 30% by mass, and still more preferably 1.0% by mass to 20% by mass with respect to the total mass of the outermost layer.

[0617] From the viewpoint of visual recognition, the content M of the above-mentioned color-changing compound in the above-mentioned outermost layer X and the content M of the above-mentioned infrared absorber in the above-mentioned image recording layer Y The ratio M X / M Y is preferably 0.1 or more, more preferably 0.2 or more, and particularly preferably 0.3 or more and 3.0 or less.

[0618] · Acid generator

[0619] When an acid chromogenic agent is used as the color-changing compound in the outermost layer, an acid generator is preferably included.

[0620] The "acid generator" in the present invention is a compound that generates an acid using light or heat. Specifically, it refers to a compound that generates an acid by decomposing upon infrared exposure.

[0621] As the generated acid, a strong acid having a pKa of 2 or less such as sulfonic acid or hydrochloric acid is preferred. The above-mentioned acid chromogenic agent can be colored by the acid generated by the acid generator.

[0622] Specifically, as an acid generator, from the viewpoints of sensitivity and stability, an onium salt compound is preferred.

[0623] Specific examples of the onium salt preferably used as an acid generator include the compounds described in paragraphs 0121 to 0124 of International Publication No. 2016 / 047392.

[0624] Among them, sulfonate, carboxylate, BPh4 of triarylsulfonium or diaryliodonium is preferred - , BF4 - , PF6 - , ClO4 - and the like. Here, Ph represents a phenyl group.

[0625] The acid generator can be used alone or in combination of two or more.

[0626] When the outermost layer contains an acid generator, the content of the acid generator is preferably 0.5% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, based on the total mass of the outermost layer.

[0627] · Additive

[0628] In addition to the components described above, the outermost layer may contain known additives such as a sensitizer (for example, the sensitizer described in the image recording layer), a plasticizer, and a surfactant.

[0629] The outermost layer is formed by coating with a known method and drying.

[0630] The coating amount (solid content) of the outermost layer is preferably 0.01 g / m 2 to 10 g / m 2 , more preferably 0.02 g / m 2 to 3 g / m 2 , particularly preferably 0.1 g / m 2 to 2.0 g / m 2 .

[0631] The film thickness of the outermost layer is preferably 0.1 μm to 5.0 μm, more preferably 0.3 μm to 4.0 μm.

[0632] The film thickness of the outermost layer is preferably 0.1 times to 5.0 times, more preferably 0.2 times to 3.0 times, relative to the film thickness of the image recording layer described later.

[0633] <Support]]

[0634] The lithographic printing plate precursor according to the present invention has a support.

[0635] As the support, it can be appropriately selected from known supports for lithographic printing plate precursors and used.

[0636] As the support, a support having a hydrophilic surface (hereinafter, also referred to as "hydrophilic support") is preferred.

[0637] As the support in the present invention, an aluminum plate that has been roughened by a known method and anodized is preferred. That is, the support in the present invention preferably has an aluminum plate and an anodic oxide film of aluminum disposed on the aluminum plate.

[0638] And preferably, the above-mentioned support has an aluminum plate and an anodic oxide film of aluminum disposed on the above-mentioned aluminum plate, the above-mentioned anodic oxide film is located closer to the image recording layer side than the above-mentioned aluminum plate, the above-mentioned anodic oxide film has micropores extending along the depth direction from the surface on the image recording layer side, and the average diameter of the micropores on the surface of the above-mentioned anodic oxide film exceeds 10 nm and is 100 nm or less.

[0639] Furthermore, preferably, the above-mentioned micropores are composed of a large-diameter pore portion and a small-diameter pore portion, the above-mentioned large-diameter pore portion extends from the surface of the above-mentioned anodic oxide film to a position at a depth of 10 nm to 1,000 nm, the above-mentioned small-diameter pore portion communicates with the bottom of the above-mentioned large-diameter pore portion and extends from the communication position to a position at a depth of 20 nm to 2,000 nm, the average diameter of the above-mentioned large-diameter pore portion on the surface of the above-mentioned anodic oxide film is 15 nm to 100 nm, and the average diameter of the above-mentioned small-diameter pore portion at the above-mentioned communication position is 13 nm or less.

[0640] Figure 1 is a schematic cross-sectional view of an embodiment of the aluminum support 12a.

[0641] The aluminum support 12a has a laminated structure in which an aluminum plate 18 and an anodic oxide film 20a of aluminum (hereinafter, also simply referred to as "anodic oxide film 20a") are laminated in sequence. In addition, the anodic oxide film 20a in the aluminum support 12a is located closer to the image recording layer side than the aluminum plate 18. That is, the lithographic printing plate original according to the present invention preferably has at least an anodic oxide film, an image recording layer, and a water-soluble resin layer on the aluminum plate in sequence.

[0642] - Anodic Oxide Film -

[0643] Hereinafter, a preferred embodiment of the anodic oxide film 20a will be described.

[0644] The anodic oxide film 20a is a film formed on the surface of the aluminum plate 18 by anodization, and the film has ultra-fine micropores 22a that are substantially perpendicular to the film surface and are uniformly distributed respectively. The micropores 22a extend along the thickness direction (aluminum plate 18 side) from the surface of the anodic oxide film 20a on the image recording layer side (the surface of the anodic oxide film 20a on the side opposite to the aluminum plate 18 side).

[0645] The average diameter (average opening diameter) of the micropores 22a in the surface of the anodic oxide film 20a is preferably more than 10 nm and 100 nm or less. Among them, from the viewpoint of the balance of printing durability, stain resistance, and image visual recognition, it is more preferably 15 nm to 60 nm, further preferably 20 nm to 50 nm, and particularly preferably 25 nm to 40 nm. The diameter inside the pores may be wider or narrower than that of the surface layer.

[0646] When the average diameter exceeds 10 nm, the printing durability and image visual recognition are excellent. Also, when the average diameter is 100 nm or less, the printing durability is excellent.

[0647] The average diameter of the micropores 22a is a value obtained by observing the surface of the anodic oxide film 20a with a field emission scanning electron microscope (FE-SEM) at a magnification of 150,000 times and N = 4 sheets, measuring the diameters of 50 micropores existing within a range of 400 nm × 600 nm in the 4 obtained images, and averaging them.

[0648] In addition, when the shape of the micropores 22a is not circular, the equivalent circle diameter is used. The "equivalent circle diameter" refers to 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.

[0649] The shape of the micropores 22a is not particularly limited. In Figure 1 it is substantially straight tube-shaped (substantially cylindrical), but it can be conical with a diameter decreasing toward the depth direction (thickness direction). Also, the shape of the bottom of the micropores 22a is not particularly limited and can be curved (convex) or flat.

[0650] In the support, the above-mentioned micropores may be composed of a large-diameter pore portion and a small-diameter pore portion. The large-diameter pore portion extends from the surface of the anodic oxide film to a position at a certain depth, and the small-diameter pore portion communicates with the bottom of the large-diameter pore portion and extends from the communication position to a position at a certain depth.

[0651] For example, as Figure 2 shown, the aluminum support 12b may be in a form including an aluminum plate 18 and an anodic oxide film 20b having micropores 22b composed of a large-diameter pore portion 24 and a small-diameter pore portion 26.

[0652] For example, the micropores 22b in the anodic oxide film 20b are composed of a large-diameter pore portion 24 and a small-diameter pore portion 26. The large-diameter pore portion 24 extends from the surface of the anodic oxide film to a depth of 10 nm to 1000 nm (depth D: refer to Figure 2) position, the small-diameter hole portion 26 communicates with the bottom of the large-diameter hole portion 24 and further extends from the communication position to a position with a depth of 20 nm to 2,000 nm. Specifically, for example, the method described in paragraphs 0107 to 0114 of Japanese Patent Application Laid-Open No. 2019-162855 can be used.

[0653] - Manufacturing method of support body -

[0654] As the manufacturing method of the support body used in the present invention, for example, a manufacturing method that sequentially performs the following processes is preferably used.

[0655] · Roughening treatment process: A process of performing roughening treatment on an aluminum plate

[0656] · Anodizing treatment process: A process of anodizing the roughened aluminum plate

[0657] · Hole expansion treatment process: A process of bringing the aluminum plate with an anodic oxide film obtained in the anodizing treatment process into contact with an acid aqueous solution or an alkali aqueous solution and expanding the diameter of the micropores in the anodic oxide film

[0658] Hereinafter, the steps of each process will be described in detail.

[0659] 《Roughening treatment process》

[0660] The roughening treatment process is a process of performing roughening treatment including electrochemical roughening treatment on the surface of the aluminum plate. This process is preferably performed before the anodizing treatment process described below, but if the surface of the aluminum plate already has a preferred surface shape, this process does not need to be particularly performed. It can be performed by the method described in paragraphs 0086 to 0101 of Japanese Patent Application Laid-Open No. 2019-162855.

[0661] 《Anodizing treatment process》

[0662] Regarding the steps of the anodizing treatment process, as long as the above-mentioned micropores can be obtained, there is no particular limitation, and known methods can be cited.

[0663] In the anodizing treatment process, an aqueous solution such as sulfuric acid, phosphoric acid, and oxalic acid can be used as the electrolytic cell. For example, the concentration of sulfuric acid can be cited as 100 g / L to 300 g / L.

[0664] The conditions of the anodizing treatment can be appropriately set according to the electrolyte used, but for example, the liquid temperature can be cited as 5°C to 70°C (preferably 10°C to 60°C), and the current density can be 0.5 A / dm 2 ~60 A / dm 2 (preferably 1 A / dm 2 ~60 A / dm 2)、Voltage is 1V to 100V (preferably 5V to 50V), electrolysis time is 1 second to 100 seconds (preferably 5 seconds to 60 seconds), and film amount is 0.1 g / m 2 ~5 g / m 2 (preferably 0.2 g / m 2 ~3 g / m 2 ).

[0665] 《Hole Expansion Treatment》

[0666] The hole expansion treatment is a treatment (pore diameter expansion treatment) for expanding the diameter (pore diameter) of micropores existing in the anodic oxide film formed through the above-described anodic oxidation treatment process.

[0667] The hole expansion treatment can be carried out by bringing the aluminum plate obtained through the above-described anodic oxidation treatment process into contact with an acidic aqueous solution or an alkaline aqueous solution. The contact method is not particularly limited, and for example, an immersion method and a spraying method can be cited.

[0668] The support may have a back coating containing an organic polymer compound described in Japanese Patent Laid-Open No. 5-45885 or a silane-based compound of silicon described in Japanese Patent Laid-Open No. 6-35174 on the surface on the side opposite to the image recording layer as needed.

[0669] <Undercoat>[[]]

[0670] The lithographic printing plate precursor according to the present invention preferably has an undercoat between the image recording layer and the support. In addition, the undercoat is sometimes also referred to as an intermediate layer. The undercoat enhances the adhesion between the support and the image recording layer in the exposed portion, and makes the image recording layer easily peel off from the support in the unexposed portion. Therefore, the undercoat contributes to improving the developability without impairing the printing durability. And, in the case of infrared laser exposure, the undercoat functions as a heat insulating layer, and thus also has an effect of preventing the heat generated by exposure from diffusing to the support and causing a decrease in sensitivity.

[0671] As the compound used for the undercoat, polymers having an adsorptive group that can be adsorbed on the surface of the support and a hydrophilic group can be cited. In order to improve the adhesion to the image recording layer, a polymer having an adsorptive group and a hydrophilic group and also having a crosslinkable group is preferred. The compound used for the undercoat can be a low molecular compound or a polymer. Two or more kinds of compounds used for the undercoat can be mixed and used as needed.

[0672] When the compound used for the undercoat 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 preferred.

[0673] As the adsorptive group capable of adsorbing to the surface of the support, phenolic hydroxyl group, carboxyl group, -PO3H2, -OPO3H2, -CONHSO2-, -SO2NHSO2-, -COCH2COCH3 are preferred. As the hydrophilic group, sulfo group or its salt, salt of carboxyl group are preferred. As the crosslinkable group, acryloyl group, methacryloyl group, acrylamide group, methacrylamide group, allyl group, etc. are preferred.

[0674] The polymer may have a crosslinkable group introduced by the formation of a salt of a polar substituent of the polymer and a compound having a substituent with a charge opposite to that of the above polar substituent and an ethylenic unsaturated bond, and may be further copolymerized with monomers other than the above, preferably hydrophilic monomers.

[0675] Specifically, a silane coupling agent having an ethylenic double bond reactive group capable of addition polymerization described in Japanese Patent Laid-Open No. 10-282679, and a phosphorus compound having an ethylenic double bond reactive group described in Japanese Patent Laid-Open No. 2-304441 can be preferably cited. It is also preferable to use a low molecular weight or high molecular weight compound having a crosslinkable group (preferably an ethylenic unsaturated bond group), a functional group interacting with the surface of the support, and a hydrophilic group described in each of Japanese Patent Laid-Open Nos. 2005-238816, 2005-125749, 2006-239867, and 2006-215263.

[0676] As a more preferable compound, a polymer having an adsorptive group capable of adsorbing to the surface of the support, a hydrophilic group, and a crosslinkable group described in Japanese Patent Laid-Open Nos. 2005-125749 and 2006-188038 can be cited.

[0677] The content of the ethylenic unsaturated bond group in the polymer used in the undercoat is preferably 0.1 mmol to 10.0 mmol, more preferably 0.2 mmol to 5.5 mmol per 1 g of the polymer.

[0678] The weight average molecular weight (Mw) of the polymer used in the undercoat is preferably 5,000 or more, more preferably 10,000 to 300,000.

[0679] -Hydrophilic compound-

[0680] From the viewpoint of developability, the undercoat preferably contains a hydrophilic compound.

[0681] As the hydrophilic compound, there is no particular limitation, and known hydrophilic compounds used in the undercoat can be used.

[0682] As hydrophilic compounds, carboxymethyl cellulose, dextrin, phosphonic acids having an amino group, organic phosphonic acids, organic phosphoric acids, organic hypophosphorous acids, amino acids, and hydrochlorides of amines having a hydroxyl group are preferably selected.

[0683] Moreover, as hydrophilic compounds, compounds having an amino group or a functional group having polymerization inhibitory 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-benzoquinone, chloroquinone, sulfophthalic acid, ethylenediaminetetraacetic acid (EDTA) or its salts, hydroxyethylenediaminetriacetic acid or its salts, dihydroxyethylenediaminediacetic acid or its salts, hydroxyethyliminodiacetic acid, etc. or their salts, etc.) are preferably selected.

[0684] As hydrophilic compounds, hydroxycarboxylic acids or their salts are preferably included from the viewpoint of scratch stain inhibition.

[0685] Moreover, from the viewpoint of scratch stain inhibition, the hydrophilic compound (preferably a hydroxycarboxylic acid or its salt) is preferably included in the layer on the above-described aluminum support. Moreover, the layer on the above-described aluminum support is preferably the layer on the side where the image recording layer is formed, and is preferably the layer in contact with the above-described aluminum support.

[0686] As the layer on the above-described aluminum support, as the layer in contact with the above-described aluminum support, a subbing layer or an image recording layer is preferably selected. Moreover, a hydrophilic compound (preferably a hydroxycarboxylic acid or its salt) may be included in a layer other than the layer in contact with the above-described aluminum support, for example, the outermost layer or the image recording layer.

[0687] In the lithographic printing plate precursor according to the present invention, from the viewpoint of scratch stain inhibition, the image recording layer preferably contains a hydroxycarboxylic acid or its salt.

[0688] Moreover, in the lithographic printing plate precursor according to the present invention, a method of surface-treating the surface on the image recording layer side of the aluminum support with a composition (for example, an aqueous solution, etc.) containing at least a hydroxycarboxylic acid or its salt is also preferably selected. In the case of the above-described method, at least a part of the treated hydroxycarboxylic acid or its salt can be detected in a state of being included in the layer on the image recording layer side in contact with the aluminum support (for example, the image recording layer or the subbing layer).

[0689] By including a hydroxycarboxylic acid or its salt in a layer on the image recording layer side in contact with the aluminum support such as a subbing layer, the surface on the image recording layer side of the aluminum support can be hydrophilized, and the contact angle with water based on the airborne water droplet method of the surface on the image recording layer side of the aluminum support can be easily set to 110° or less, and the scratch stain inhibition is excellent.

[0690] Hydroxycarboxylic acids are a general term for organic compounds having one or more carboxyl groups and one or more hydroxyl groups in one molecule, and are also called hydroxy acids, oxyacids, hydroxycarboxylic acids, and alcohol acids (refer to the 5th edition of the Iwanami Dictionary of Physics and Chemistry, published by Iwanami Shoten (1998)).

[0691] The above-mentioned hydroxycarboxylic acid or its salt is preferably a compound represented by the following formula (HC).

[0692] R HC (OH) mhc (COOM HC ) nhc Formula (HC)

[0693] In formula (HC), R HC represents an organic group having a valence of mhc + nhc, and M HC each independently represents a hydrogen atom, an alkali metal, or an onium, mhc and nhc each independently represent an integer of 1 or more, and when n is 2 or more, M HC can be the same or different.

[0694] In formula (HC), examples of the organic group having a valence of mhc + nhc represented by R HC include a hydrocarbon group having a valence of mhc + nhc. The hydrocarbon group may have a substituent and / or a linking group.

[0695] As the hydrocarbon group, there can be mentioned an mhc + nhc-valent group derived from an aliphatic hydrocarbon, such as an alkylene group, an alkane triyl group, an alkane tetrayl group, an alkane pentayl group, an alkenylene group, an alkene triyl group, an alkene tetrayl group, an alkene pentayl group, an alkynylene group, an alkyne triyl group, an alkyne tetrayl group, an alkyne pentayl group, etc., and an mhc + nhc-valent group derived from an aromatic hydrocarbon, such as an arylene group, an arene triyl group, an arene tetrayl group, an arene pentayl group, etc. As the substituent, there can be mentioned an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, etc. Specific examples of the substituent can be mentioned a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a 2-methylhexyl group, a cyclohexyl group, a cyclopentyl group, a 2-norbornyl group, a methoxymethyl group, a methoxyethoxyethyl group, an allyloxymethyl group, a phenoxymethyl group, an acetoxymethyl group, a benzoyloxymethyl group, a benzyl group, a phenethyl group, an α-methylbenzyl group, a 1-methyl-1-phenylethyl group, a p-methylbenzyl group, a cinnamyl group, an allyl group, a 1-propenylmethyl group, a 2-butenyl group, a 2-methylallyl group, a 2-methylpropenylmethyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a phenyl group, a biphenyl group, a naphthyl group, a tolyl group, a xylyl group, a mesityl group, a cumenyl group, a methoxyphenyl group, an ethoxyphenyl group, a phenoxyphenyl group, an acetoxyphenyl group, a benzoyloxyphenyl group, a methoxycarbonylphenyl group, an ethoxycarbonylphenyl group, a phenoxycarbonylphenyl group, etc. And the linking group is composed of at least one kind of atom selected from a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom, and the number of its atoms is preferably 1 to 50. Specifically, there can be mentioned an alkylene group, a substituted alkylene group, an arylene group, a substituted arylene group, etc., and there can be a structure in which these divalent groups are linked by any one of an amide bond, an ether bond, a urethane bond, a urea bond, and an ester bond.

[0696] As the alkali metal represented by M HC There can be mentioned lithium, sodium, potassium, etc., and sodium is particularly preferred. As the onium, there can be mentioned ammonium, phosphonium, sulfonium, etc., and ammonium is particularly preferred.

[0697] And, from the viewpoint of scratch contamination inhibition, M HC Is preferably an alkali metal or onium, and more preferably an alkali metal.

[0698] The total number of mhc and nhc is preferably 3 or more, more preferably 3 to 8, and further preferably 4 to 6.

[0699] The molecular weight of the above hydroxycarboxylic acid or its salt is preferably 600 or less, more preferably 500 or less, and particularly preferably 300 or less. And the above molecular weight is preferably 76 or more.

[0700] Regarding the above-mentioned hydroxycarboxylic acids or hydroxycarboxylic acids constituting the salts of the above-mentioned hydroxycarboxylic acids, specifically, gluconic acid, glycolic acid, lactic acid, malic acid, hydroxybutyric acid (2-hydroxybutyric acid, 3-hydroxybutyric acid, γ-hydroxybutyric acid, etc.), malic acid, tartaric acid, citromalic acid, citric acid, isocitric acid, leucine, mevalonic acid, pantothenic acid, ricinoleic acid, ricinelaidic acid, cerebronic acid, quinic acid, shikimic acid, monohydroxybenzoic acid derivatives (salicylic acid, creosotic acid (homosalicylic acid, hydroxy(methyl)benzoic acid), vanillic acid, syringic acid, etc.), dihydroxybenzoic acid derivatives (pyrocatechol, dihydroxybenzoic acid, protocatechuic acid, gentisic acid, orsellinic acid, etc.), trihydroxybenzoic acid derivatives (gallic acid, etc.), phenylacetic acid derivatives (mandelic acid, benzilic acid, atrolactic acid, etc.), hydrocinnamic acid derivatives (o-hydroxycinnamic acid, phloretic acid, coumaric acid, umbellic acid, caffeic acid, ferulic acid, sinapic acid, cerebronic acid, carminic acid, etc.) can be cited.

[0701] Among these, as the above-mentioned hydroxycarboxylic acids or hydroxycarboxylic acids constituting the salts of the above-mentioned hydroxycarboxylic acids, from the viewpoint of scratch contamination inhibition, compounds having 2 or more hydroxyl groups are preferred, compounds having 3 or more hydroxyl groups are more preferred, compounds having 5 or more hydroxyl groups are further preferred, and compounds having 5 to 8 hydroxyl groups are particularly preferred.

[0702] Moreover, as a compound having 1 carboxyl group and 2 or more hydroxyl groups, gluconic acid or shikimic acid is preferred.

[0703] As a compound having 2 or more carboxyl groups and 1 hydroxyl group, citric acid or malic acid is preferred.

[0704] As a compound having 2 or more carboxyl groups and hydroxyl groups respectively, tartaric acid is preferred.

[0705] Among them, as the above-mentioned hydroxycarboxylic acid, gluconic acid is particularly preferred.

[0706] The hydrophilic compound can be used alone or 2 or more kinds can be used simultaneously.

[0707] When the undercoat contains a hydrophilic compound (preferably a hydroxycarboxylic acid or its salt), the content of the hydrophilic compound (preferably a hydroxycarboxylic acid or its salt) is preferably 0.01% by mass to 50% by mass, more preferably 0.1% by mass to 40% by mass, and particularly preferably 1.0% by mass to 30% by mass with respect to the total mass of the undercoat.

[0708] In the undercoat, in addition to the above-mentioned undercoat compounds, in order to prevent contamination over time, a chelating agent, a secondary amine or a tertiary amine, a polymerization inhibitor, etc. can also be contained.

[0709] The undercoat can be coated by a known method.

[0710] The coating amount (solid content) of the undercoat is preferably 0.1 mg / m 2 ~300 mg / m 2 , more preferably 5 mg / m 2 ~200 mg / m 2 .

[0711] The lithographic printing plate original of the present invention may have other layers in addition to the above layers.

[0712] As the other layers, there is no particular limitation, and known layers can be provided. For example, if necessary, an undercoat layer can be provided on the side of the support opposite to the image recording layer side.

[0713] (Method for producing a lithographic printing plate and lithographic printing method)

[0714] The method for producing a lithographic printing plate of the present invention preferably includes: a step of exposing the lithographic printing plate original of the present invention into an image (exposure step); and a step of supplying at least one selected from printing ink and dampening solution to the exposed lithographic printing plate original on a printing press to remove the image recording layer of the non-image portion (on-press development step).

[0715] The lithographic printing method of the present invention preferably includes: a step of exposing the lithographic printing plate original of the present invention into an image (exposure step); a step of supplying at least one selected from printing ink and dampening solution on a printing press to remove the image recording layer of the non-image portion to produce a lithographic printing plate (on-press development step); and a step of performing printing using the obtained lithographic printing plate (hereinafter, also referred to as "printing step").

[0716] <Exposure step>

[0717] The method for producing a lithographic printing plate of the present invention preferably includes an exposure step of exposing the lithographic printing plate original of the present invention into an image to form an exposed portion and an unexposed portion. The lithographic printing plate original of the present invention is preferably exposed into an image by laser exposure through a transparent original image having a line image, a halftone image, etc. or by laser beam scanning based on digital data.

[0718] A light source having a wavelength of 750 nm to 1,400 nm can be preferably used. As the light source having a wavelength of 750 nm to 1,400 nm, a solid laser and a semiconductor laser that emit infrared rays are preferred. Regarding the infrared laser, the output power is preferably 100 mW or more, the exposure time per pixel is preferably within 20 microseconds, and the irradiation energy is preferably 10 mJ / cm 2 ~300 mJ / cm 2Moreover, in order to shorten the exposure time, it is preferable to use a multi-beam laser device. The exposure mechanism can be any one of an internal drum type, an external drum type, a flat plate type, etc.

[0719] Regarding image exposure, it can be performed by a conventional method using a plate-making machine or the like. In the case of on-press development, after mounting the original lithographic printing plate on the printing press, image exposure can be performed on the printing press.

[0720] Furthermore, various parameter settings such as SD (depth of focus), Slope (linear slope of the laser), Curve (arrangement curvature of the laser), etc. can be performed during exposure.

[0721] In the above parameter settings, development can be performed using the ink and dampening solution described later, image-like exposure for parameter setting can also be performed, and development can also be performed using a liquid other than the ink and dampening solution. As the liquid other than the above ink and dampening solution, any liquid capable of on-press development can be used, for example, a developing solution, a fixing solution, a plate-sealing adhesive solution, etc. can be cited.

[0722] Moreover, in the case of development using a liquid other than the ink and dampening solution, after development, the plate surface can be cleaned with water or the like. In order to further improve the visual recognition of the image portion, an acidic solution can also be brought into contact with the plate surface. The acid contained in the acidic solution is not particularly limited, but carboxylic acids such as acetic acid, hydroxycarboxylic acids such as citric acid, and their salts, etc. can be preferably cited, and citric acid is particularly preferred. Moreover, when preparing the acidic solution, at least one selected from water and a solvent for dissolving the acid can also be used.

[0723] The solvent for preparing the acidic solution is not particularly limited, but from the viewpoints of acid solubility and on-press developability, a mixed solvent composed of water and ethanol can be preferably cited. As the solvent, a kitchen alcohol disinfectant can also be used. The above methods of development, cleaning, and bringing it into contact with the acidic solution are not particularly limited and can be performed by known methods. For example, a method of coating the plate surface with a sponge or cloth, etc. can be preferably cited.

[0724] <On-press development process>

[0725] The method for manufacturing a lithographic printing plate according to the present invention preferably includes an on-press development process of supplying at least one selected from printing ink and dampening solution on the printing press to remove the image recording layer in the non-image portion.

[0726] Hereinafter, the on-press development method will be described.

[0727] 〔On-press development method〕

[0728] In the on-press development method, for a lithographic printing plate original that has been image-exposed, it is preferable to produce a lithographic printing plate by supplying an oil-based ink and an aqueous component onto a printing press and removing the image recording layer in the non-image areas.

[0729] That is, if, after image-exposing the lithographic printing plate original, it is directly installed on the printing press without performing any developing treatment, or if, after installing the lithographic printing plate original on the printing press, image exposure is carried out on the printing press, then an oil-based ink and an aqueous component are supplied and printing is performed. In the initial stage during printing, in the non-image areas, the image recording layer that has not been cured by either or both of the supplied oil-based ink and aqueous component dissolves or disperses and is removed, so that the hydrophilic surface is exposed in this part. On the other hand, in the exposed areas, the image recording layer cured by exposure forms an oil-based ink receiving part with a lipophilic surface. The compound initially supplied to the plate surface can be an oil-based ink or an aqueous component, but from the aspect of preventing contamination by the components of the image recording layer from which the aqueous component has been removed, it is preferable to initially supply an oil-based ink. Thus, the lithographic printing plate original is developed on the printing press and directly used for multiple printings. As the oil-based ink and the aqueous component, it is preferable to use ordinary printing inks for lithographic printing and dampening solutions.

[0730] As the laser for image-exposing the lithographic printing plate original according to the present invention, a light source with a wavelength of preferably 750 nm to 1,400 nm can be used. As the light source with a wavelength of 750 nm to 1,400 nm, the above-mentioned light source can be preferably used.

[0731] <Printing process>

[0732] The lithographic printing method according to the present invention includes a printing process of supplying a printing ink to the lithographic printing plate and printing a recording medium.

[0733] There is no particular limitation on the printing ink, and various known inks can be used as needed. And, as the printing ink, an oil-based ink or an ultraviolet curable ink (UV ink) can be preferably selected.

[0734] And, in the above printing process, a dampening solution can be supplied as needed.

[0735] And, in the above printing process, without stopping the printing press, it can be continuously carried out in the above on-press development process or the above developing solution development process.

[0736] There is no particular limitation on the recording medium, and known recording media can be used as needed.

[0737] In the method for producing a lithographic printing plate from the lithographic printing plate original according to the present invention and the lithographic printing method according to the present invention, the entire surface of the lithographic printing plate original can be heated as needed before exposure, during exposure, or from exposure to development. By this heating, the image formation reaction in the image recording layer can be promoted, and advantages such as an increase in sensitivity or printing durability and stabilization of sensitivity can be achieved. Regarding the heating before development, it is preferably carried out under mild conditions at 150 °C or lower. In the above manner, problems such as curing of the non-image area can be prevented. For the heating after development, very strong conditions are preferably used, 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 area can be suppressed.

[0738] <Other methods>

[0739] Another aspect of the method for making a lithographic printing plate according to the present invention can be exemplified by a method including an image exposure step (also referred to as an "image exposure step") of exposing the lithographic printing plate original according to the present invention and a development step (also referred to as a "developer development step") of supplying a developer to remove the unexposed areas.

[0740] The above method for making a lithographic printing plate is hereinafter also referred to as the "developer treatment method".

[0741] Preferably, another aspect of the lithographic printing method according to the present disclosure is a method of making and printing a lithographic printing plate using the lithographic printing plate original according to the present disclosure, and includes an image exposure step (also referred to as an "image exposure step") of exposing the lithographic printing plate original according to the present disclosure, a development step (also referred to as a "developer development step") of supplying a developer to remove the unexposed areas, and a printing step (also referred to as a "printing step") of printing using the obtained lithographic printing plate.

[0742] For the "image exposure step", "developer development step", and "printing step", known methods can be applied according to the lithographic printing plate original used.

[0743] Examples

[0744] Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto. In addition, in the present examples, "%" and "parts" respectively refer to "mass %" and "mass parts" unless otherwise specified.

[0745] <Synthesis example of polymer P-1>

[0746] In a 200 mL Erlenmeyer flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 10.0 g of monomethyl propylene glycol (manufactured by FUJIFILM Wako Pure Chemical Corporation) was placed, the internal temperature was set to 80 °C, and nitrogen replacement was carried out. A solution prepared by mixing 7.2 g of monomer K-1 (trade name: SILAPLANE TM-0701T, manufactured by JNC Corporation), 10.8 g of monomer H-23 (2-hydroxyethyl methacrylate, manufactured by FUJIFILM Wako Pure Chemical Corporation), 0.72 g of dimethyl 2,2'-azobis(isobutyrate) (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 28.8 g of monomethyl propylene glycol was added dropwise over 2 hours. A mixed solution of 0.07 g of 2,2'-azobis(isobutyrate) dimethyl and 3.3 g of monomethyl propylene glycol was added. After stirring at an internal temperature of 80 °C for 1 hour, the internal temperature was set to 100 °C and further heated for 2 hours to obtain polymer P-1.

[0747] The weight-average molecular weight of the obtained polymer P-1 was 21,600, and the molecular weight distribution was 6.1 (calculated in terms of polystyrene under the measurement conditions of an eluent of THF, a flow rate of 0.35 ml / min, and a temperature of 40 °C using a gel permeation chromatograph (EcoSEC HLC-8320GPC, manufactured by TOSOH CORPORATION), and the columns used were TSKgel SuperHZM-H, TSKgel SuperHZ4000, and TSKgel SuperHZ200 (manufactured by TOSOH CORPORATION)).

[0748] <Synthesis example of polymer P-2>

[0749] Polymer P-2 was synthesized in the same manner as the synthesis example of polymer P-1, except that monomer H-23 was replaced with monomer H-24 (2-hydroxyethyl acrylamide, manufactured by Tokyo Chemical Industry Co., Ltd.).

[0750] <Synthesis example of polymer P-3>

[0751] Polymer P-3 was synthesized in the same manner as the synthesis example of polymer P-1, except that monomer H-23 was replaced with monomer H-7 (n = 9) (trade name: BLEMMER PP-500, manufactured by NOF CORPORATION).

[0752] <Synthesis example of polymer P-4>

[0753] The amount of monomer K-1 was changed to 9.0 g, monomer H-23 was replaced with monomer H-7 (n = 9) (trade name: BLEMMER PP-500, manufactured by NOF CORPORATION.), and the amount of monomer H-7 was set to 9.0 g. Otherwise, polymer P-4 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0754] <Synthesis example of polymer P-5>

[0755] The amount of monomer K-1 was changed to 10.8 g, monomer H-23 was replaced with monomer H-7 (n = 9) (trade name: BLEMMER PP-500, manufactured by NOF CORPORATION.), and the amount of monomer H-7 was set to 7.2 g. Otherwise, polymer P-5 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0756] <Synthesis example of polymer P-6>

[0757] The amount of monomer K-1 was changed to 5.4 g, monomer H-23 was replaced with monomer H-7 (n = 9) (trade name: BLEMMER PP-500, manufactured by NOF CORPORATION.), and the amount of monomer H-7 was set to 12.6 g. Otherwise, polymer P-6 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0758] <Synthesis example of polymer P-7>

[0759] Monomer H-23 was replaced with monomer H-3 (n = 8) (trade name: BLEMMER PE-350, manufactured by NOF CORPORATION.), and the amount of monomer H-3 was changed to 10.8 g. Otherwise, polymer P-7 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0760] <Synthesis example of polymer P-8>

[0761] Monomer H-23 was replaced with monomer H-3 (n = 8) (trade name: BLEMMER PE-350, manufactured by NOF CORPORATION.), and the amount of monomer H-3 was changed to 0.8 g. Otherwise, polymer P-8 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0762] <Synthesis example of polymer P-9>

[0763] The monomer H-23 was replaced with monomer H-25 (n = 6) (trade name: BLEMMER 10PPB-500 manufactured by NOF CORPORATION.), and the amount of monomer H-25 was changed to 10.8 g. Otherwise, polymer P-9 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0764] <Synthesis example of polymer P-10>

[0765] The monomer H-23 was replaced with monomer H-14 (m = 3.5, n = 2.5) (trade name: BLEMMER 50PEP-300 manufactured by NOF CORPORATION.), and the amount of monomer H-14 was changed to 10.8 g. Otherwise, polymer P-10 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0766] <Synthesis example of polymer P-14>

[0767] The monomer H-23 was replaced with monomer H-4 (n = 4) (trade name: BLEMMER PME-200 manufactured by NOF CORPORATION.), and the amount of monomer H-4 was changed to 10.8 g. Otherwise, polymer P-14 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0768] <Synthesis example of polymer P-16>

[0769] The monomer H-23 was replaced with monomer H-4 (n = 4) (trade name: BLEMMER PME-200 manufactured by NOF CORPORATION.), the amount of monomer K-1 was changed to 5.4 g, and the amount of monomer H-4 was changed to 12.6 g. Otherwise, polymer P-16 was synthesized in the same manner as in the synthesis example of polymer P-1.

[0770] The structures of polymers P-1 to P-10, P-14, and P-16 synthesized as described above are shown below. Also, polymer P-11 having the structure shown below was prepared.

[0771] In addition, the weight-average molecular weights of polymers P-1 to P-11, P-14, and P-16 are shown in Table 3.

[0772] [Chemical formula 41]

[0773]

[0774] [Chemical formula 42]

[0775]

[0776] Further, as comparative polymers, Polymer P-12 (manufactured by DIC CORPORATION, MEGAFACE (registered trademark: F-176PF)), Polymer P-13 having the following structure, and Polymer P-15 were prepared.

[0777] In addition, the weight-average molecular weights of Polymers P-12, P-13, and P-15 are shown in Table 3.

[0778] [Chemical formula 43]

[0779]

[0780] [Chemical formula 44]

[0781]

[0782] (Examples 1 to 16, 19, 25, 29, 30, Comparative Examples 1 to 3, 9: on-machine developable lithographic printing plate precursor)

[0783] <Fabrication of Support A>

[0784] (Mechanical roughening treatment (brush grain method))

[0785] Using the apparatus shown as Figure 5 while supplying pumice suspension (specific gravity 1.1 g / cm 3 ) as a polishing slurry to the surface of the aluminum plate, mechanical roughening treatment was performed with a rotating hard hair brush bundle. In Figure 5 , 1 is an aluminum plate, 2 and 4 are drum-shaped brushes (hard hair brush bundles in this example), 3 is a polishing slurry, and 5, 6, 7, and 8 are support rollers.

[0786] In the mechanical roughening treatment, the median particle size (μm) of the abrasive material was set to 30 μm, the number of brushes was set to 4, and the rotational speed of the brushes per minute (rpm: the same hereinafter) was set to 250 rpm. The material of the hard hair brush bundle was 6 / 10 nylon, the diameter of the bristles was 0.3 mm, and the hair length was 50 mm. Regarding the brush, holes were drilled in a stainless steel sleeve with a diameter of φ300 mm and the hair was densely planted. The distance between the two support rollers (φ200 mm) at the lower part of the hard hair brush bundle was 300 mm. The hard hair brush bundle was pressed until the load of the drive motor for rotating the brush increased by 10 kW relative to the load before pressing the hard hair brush bundle against the aluminum plate. The rotational direction of the brush was the same as the moving direction of the aluminum plate.

[0787] (Alkaline etching treatment)

[0788] At a temperature of 70 °C, an etching treatment was carried out by spraying an aqueous sodium hydroxide solution with a sodium hydroxide concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass onto the aluminum plate obtained above using a nozzle. Then, spray washing was performed. The aluminum dissolution amount was 10 g / m 2 .

[0789] (Desmut treatment in acidic aqueous solution)

[0790] Next, a desmut treatment was carried out in a nitric acid aqueous solution. The nitric acid aqueous solution used for the desmut treatment was the waste liquid of nitric acid for the electrochemical roughening in the next process. Its liquid temperature was 35 °C. The desmutting liquid was sprayed with a sprayer for 3 seconds for the desmut treatment.

[0791] (Electrochemical roughening treatment)

[0792] The electrochemical roughening treatment was continuously carried out using an alternating current voltage of 60 Hz with nitric acid electrolysis. At this time, the electrolytic solution used was an electrolytic solution in which aluminum nitrate was added to an aqueous solution of nitric acid at a temperature of 35 °C and a nitric acid concentration of 10.4 g / L to adjust the aluminum ion concentration to 4.5 g / L. The waveform of the alternating current power supply was Figure 3 the waveform shown, using a rectangular wave alternating current with a trapezoidal shape where the time tp from zero to the peak value of the current was 0.8 msec, a duty ratio of 1:1, and the carbon electrode was used as the counter electrode for the electrochemical roughening treatment. The auxiliary anode used was ferrite. The electrolytic cell used was Figure 4 the electrolytic cell shown. The current density was 30 A / dm based on the peak value of the current 2 , and 5% of the current flowing out from the power supply was shunted to the auxiliary anode. The quantity of electricity (C / dm 2 ) was 185 C / dm based on the total quantity of electricity when the aluminum plate was used as the anode 2 . Then, spray washing was performed.

[0793] (Alkaline etching treatment)

[0794] At a temperature of 50 °C, an etching treatment was carried out by spraying an aqueous sodium hydroxide solution with a sodium hydroxide concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass onto the aluminum plate obtained above using a nozzle. Then, spray washing was performed. The aluminum dissolution amount was 0.5 g / m 2 .

[0795] (Desmut treatment in acidic aqueous solution)

[0796] Next, a desmut treatment was carried out in a sulfuric acid aqueous solution. The sulfuric acid aqueous solution used for the desmut treatment was a solution with a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L. Its liquid temperature was 30 °C. The desmutting liquid was sprayed with a sprayer for 3 seconds for the desmut treatment.

[0797] (Electrochemical roughening treatment)

[0798] Electrochemical roughening treatment was continuously carried out using hydrochloric acid electrolysis with an alternating voltage of 60 Hz. As the electrolytic solution, an electrolytic solution in which aluminum ions were adjusted to a concentration of 4.5 g / L by adding aluminum chloride to an aqueous solution of hydrochloric acid at 6.2 g / L at a liquid temperature of 35°C was used. The waveform of the AC power supply was Figure 3 the waveform shown, and electrochemical roughening treatment was carried out using a rectangular wave alternating current of trapezoid with a current value reaching from zero to the peak time tp of 0.8 msec, a duty ratio of 1:1, and using a carbon electrode as the counter electrode. A ferrite was used as the auxiliary anode. The electrolytic cell used was Figure 4 the electrolytic cell shown.

[0799] The current density was 25 A / dm based on the peak value of the current 2 , and the amount of electricity (C / dm 2 ) in hydrochloric acid electrolysis, based on the total amount of electricity when the aluminum plate was used as the anode, was 63 C / dm 2 . Then, spray water washing was carried out.

[0800] (Alkali etching treatment)

[0801] At a temperature of 50°C, etching treatment was carried out by spraying a caustic soda aqueous solution with a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass onto the aluminum plate obtained above using a nozzle. Then, spray water washing was carried out. The amount of aluminum dissolved was 0.1 g / m 2 .

[0802] (Detergent treatment in acidic aqueous solution)

[0803] Next, detergent treatment was carried out in a sulfuric acid aqueous solution. Specifically, using the waste liquid generated in the anodizing treatment process (aluminum ions 5 g / L were dissolved in a 170 g / L aqueous solution of sulfuric acid), detergent treatment was carried out for 4 seconds at a liquid temperature of 35°C. Detergent solution was sprayed with a sprayer to carry out detergent treatment for 3 seconds.

[0804] (First-stage anodizing treatment)

[0805] The first-stage anodizing treatment was carried out using a direct current electrolysis anodizing treatment device based on the structure shown in Figure 6 . Anodizing treatment was carried out under the conditions shown in Table 1, and an anodic oxide film with a specified film thickness was formed.

[0806] In addition, in the anodizing treatment device 610, the aluminum plate 616 was as shown in Figure 6It is conveyed as shown by the arrow in the figure. In the power supply tank 612 storing the electrolytic solution 618, the aluminum plate 616 is charged with (+) electricity through the power supply electrode 620. And for the aluminum plate 616, it is conveyed upward in the power supply tank 612 by the roller 622, and after changing the direction downward through the pinch roller 624, it is conveyed to the electrolytic treatment tank 614 storing the electrolytic solution 626, and the direction is changed to the horizontal direction by the roller 628. Then, the aluminum plate 616 is charged with (-) electricity through the electrolytic electrode 630, and thus an anodic oxide film is formed on its surface. The aluminum plate 616 leaving the electrolytic treatment tank 614 is conveyed to the subsequent process. In the anodic oxidation treatment apparatus 610, a direction changing mechanism is constituted by the roller 622, the pinch roller 624, and the roller 628. In the inter-tank part between the power supply tank 612 and the electrolytic treatment tank 614, the aluminum plate 616 is conveyed in a mountain shape and an inverted U shape through the above rollers 622, 624, and 628. The power supply electrode 620 and the electrolytic electrode 630 are connected to the DC power supply 634. A tank wall 632 is arranged between the power supply tank 612 and the electrolytic treatment tank 614.

[0807] (Hole expansion treatment)

[0808] Under the conditions shown in Table 1, the aluminum plate subjected to the above anodic oxidation treatment was immersed in an aqueous sodium hydroxide solution having a temperature of 35 °C, a sodium hydroxide concentration of 5% by mass, and an aluminum ion concentration of 0.5% by mass, and hole expansion treatment was performed. Then, spray water washing was carried out.

[0809] (Second-stage anodic oxidation treatment)

[0810] Using the anodic oxidation apparatus of DC electrolysis based on the structure shown in Figure 6 the second-stage anodic oxidation treatment was carried out. The anodic oxidation treatment was carried out under the conditions shown in Table 1, and an anodic oxide film with a specified film thickness was formed.

[0811] (Third-stage anodic oxidation treatment)

[0812] Using the anodic oxidation apparatus of DC electrolysis based on the structure shown in Figure 6 the third-stage anodic oxidation treatment was carried out. The anodic oxidation treatment was carried out under the conditions shown in Table 1, and an anodic oxide film with a specified film thickness was formed.

[0813] After the above surface treatment, the support A described in Tables 1 and 2 was obtained.

[0814] The average diameter (nm) of the large-diameter hole part in the anodic oxide film with micropores after the second anodic oxidation treatment process obtained above on the surface of the anodic oxide film, the average diameter (nm) of the small-diameter hole part at the communication position, the depths (nm) of the large-diameter hole part and the small-diameter hole part, the dent density (density of micropores, unit: number / μm 2)、and the thickness (nm) of the anodic oxide film from the bottom of the small-diameter hole portion to the aluminum plate surface is summarized in Table 2.

[0815] In addition, the average diameter of the micropores (the average diameters of the large-diameter hole portion and the small-diameter hole portion) is as follows: Using FE-SEM at a magnification of 150,000 times, observe the surfaces of the large-diameter hole portion and the small-diameter hole portion for N = 4 sheets. In the obtained 4 images, measure the diameters of the micropores (large-diameter hole portion and small-diameter hole portion) existing in the range of 400 nm × 600 nm, and obtain the value by averaging. In addition, when the depth of the large-diameter hole portion is deep and it is difficult to measure the diameter of the small-diameter hole portion and when measuring the enlarged-diameter hole portion in the small-diameter hole portion, cut the upper part of the anodic oxide film, and then find out various diameters.

[0816] The depth of the micropores (the depths of the large-diameter hole portion and the small-diameter hole portion) is as follows, that is, use FE-SEM to observe the cross-section of the support (anodic oxide film) (observation of the depth of the large-diameter hole portion: 150,000 times, observation of the depth of the small-diameter hole portion: 50,000 times). In the obtained image, measure the depths of any 25 micropores and obtain the value by averaging.

[0817] In addition, in Table 1, the film amount (AD) in the first anodic oxidation treatment column and the film amount (AD) in the second anodic oxidation treatment column represent the film amounts obtained in each treatment. In addition, the electrolyte used is an aqueous solution containing the components in Table 1.

[0818] [Table 1]

[0819]

[0820] [Table 2]

[0821]

[0822] [Formation of Undercoat A]

[0823] On the support A, coat the coating liquid for the undercoat with the following composition so that the dry coating amount becomes 0.1 g / m 2 to form Undercoat A.

[0824] [Coating Liquid for Undercoat]

[0825] · Compound for undercoat (the above U-1, 11% aqueous solution): 0.10502 parts

[0826] · Sodium gluconate: 0.0700 parts

[0827] · Surfactant (EMALEX (registered trademark) 710, manufactured by NIHON EMULSION Co., Ltd.): 0.00159 parts

[0828] · Preservative (Biohope L, K·I Chemical Industry Co., LTD.): 0.00149 parts

[0829] · Water: 2.8719 parts

[0830] [Chemical formula 45]

[0831]

[0832] <Formation of Image Recording Layer A>

[0833] The following coating solution for Image Recording Layer A was bar-coated on the undercoat A and dried at 120 °C for 40 seconds to form an Image Recording Layer A with a dry coating amount of 1.0 g / m 2 of Image Recording Layer A.

[0834] - Coating Solution for Image Recording Layer A -

[0835] Infrared absorber (the following IR-1): 0.0270 parts

[0836] Infrared absorber (the following IR-2): 0.0080 parts

[0837] Color former (the following S-1): 0.0300 parts

[0838] Color former (the following S-2): 0.0120 parts

[0839] Onium-based polymerization initiator (the following I-1): 0.1000 parts

[0840] Borate compound (sodium tetraphenylborate (TPB)): 0.0200 parts

[0841] · Polymerizable compound (the following M-4): 0.2726 parts

[0842] Anionic surfactant (the following A-1): 0.0200 parts

[0843] The polymer described in Table 3 below: the amount described in Table 3 (addition amount)

[0844] · 2-butanone: 4.9839 parts

[0845] 1-methoxy-2-propanol: 3.1009 parts

[0846] Methanol: 3.1239 parts

[0847] The following microgel solution 1: 2.3256 parts

[0848] [Chemical formula 46]

[0849]

[0850] [Chemical formula 47]

[0851]

[0852] [Chemical formula 48]

[0853]

[0854] [Chemical formula 49]

[0855]

[0856] [Synthesis method of polymerizable compound M-4]

[0857] A mixed solution of Takenate D-160N (polyisocyanate-trimethylolpropane adduct, manufactured by Mitsui Chemicals, Inc., 4.7 parts), ARONIX M-403 (manufactured by TOAGOSEI CO., LTD., the amount such that the NCO value of Takenate D-160N and the hydroxyl value of ARONIX M-403 are 1:1), tert-butylbenzoquinone (0.02 part), and methyl ethyl ketone (11.5 parts) was heated to 65°C. NeoStann U-600 (bismuth-based polycondensation catalyst, manufactured by NITTO KASEI CO., LTD., 0.11 part) was added to the reaction solution, and it was heated at 65°C for 4 hours. The reaction solution was cooled to room temperature (25°C), and methyl ethyl ketone was added thereto, whereby a solution of urethane acrylate (polymerizable compound M-4) having a solid content of 50% by mass was synthesized. Using a recycled GPC (equipment: LC908-C60, column: JAIGEL-1H-40 and 2H-40 (manufactured by Japan Analytical Industry)), molecular weight fractionation of the urethane acrylate solution was carried out with an eluent of tetrahydrofuran (THF). The weight average molecular weight was 20,000.

[0858] [Synthesis method of microgel solution 1]

[0859] [Preparation of oil phase component]

[0860] 6.66 g of a polyfunctional isocyanate compound (PM-200, manufactured by CareerCross Co., Ltd.), 5.46 g of a 50% by mass ethyl acetate solution of “Takenate (registered trademark) D-116N (an adduct of trimethylolpropane (TMP), m-xylene diisocyanate (XDI) and monomethyl ether of polyethylene glycol (EO90) (the following structure)” manufactured by Mitsui Chemicals, Inc., 11.24 g of a 65% by mass ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer Company, Inc.), 14.47 g of ethyl acetate, and 0.45 g of PIONIN (registered trademark) A-41-C manufactured by Takemoto Oil & Fat Co., Ltd. were mixed and stirred at room temperature (25 °C) for 15 minutes to obtain an oil phase component.

[0861] [Chemical formula 50]

[0862]

[0863] - Preparation of aqueous phase component -

[0864] As the aqueous phase component, 47.2 g of distilled water was prepared.

[0865] - Microcapsule formation process -

[0866] The aqueous phase component was added to the oil phase component and mixed, and the resulting mixture was emulsified at 12,000 rpm for 16 minutes using a homogenizer to obtain an emulsion.

[0867] 16.8 g of distilled water was added to the obtained emulsion, and the resulting liquid was stirred at room temperature for 10 minutes.

[0868] Next, the stirred liquid was heated to 45 °C, and ethyl acetate was distilled off from the above liquid by stirring for 4 hours while maintaining the liquid temperature at 45 °C. Then, 5.12 g of a 10% by mass aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-ene-octanoate (U-CAT SA102, manufactured by San-Apro Ltd.) was added, stirred at room temperature for 30 minutes, and allowed to stand at 45 °C for 24 hours. The solid component concentration was adjusted to 20% by mass with distilled water to obtain an aqueous dispersion of microgel 1. Regarding the volume average particle diameter of microgel 1, as a result of measurement by a laser diffraction / scattering particle size distribution measuring device LA-920 (manufactured by HORIBA, Ltd.), it was 165 nm.

[0869] <Formation of outermost layer (protective layer) A>

[0870] The coating liquid for the protective layer was bar-coated on the image recording layer and dried at 120 °C for 60 seconds to form the outermost layer (protective layer) A with a dry coating amount of 0.1 g / m 2 Thus, the original lithographic printing plate was fabricated.

[0871] - Coating liquid for protective layer -

[0872] Inorganic layered compound dispersion (1): 0.5625 parts

[0873] Hydrophilic polymer (1) (20% aqueous solution of the following compound): 0.0825 parts

[0874] METOLOSE SM04 (methyl cellulose, manufactured by Shin-Etsu Chemical Co., Ltd., methoxy substitution degree = 1.8): 0.0250 parts

[0875] RAPISOL A-80 (anionic surfactant, manufactured by NOF CORPORATION, 80% aqueous solution): 0.0007 parts

[0876] Ion-exchanged water: 4.3300 parts

[0877] [Chemical formula 51]

[0878]

[0879] (Examples 17 - 18, 26, 31, 32)

[0880] <Fabrication of Support B>

[0881] The following treatment was performed on an aluminum plate (aluminum alloy plate) of Material 1S with a thickness of 0.3 mm to fabricate an aluminum support. In addition, a water washing treatment was performed between all treatment steps, and drainage was carried out by a pinch roll after the water washing treatment.

[0882] (Alkaline etching treatment)

[0883] An aqueous caustic soda solution with a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass% was sprayed onto the aluminum plate at a temperature of 70 °C using a sprayer for etching treatment. Then, spray water washing was performed. The aluminum dissolution amount on the surface subjected to the electrochemical roughening treatment after that was 5 g / m 2 .

[0884] (Detergent treatment using an acidic aqueous solution)

[0885] Next, a decontamination treatment was performed using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate with a sprayer, and a decontamination treatment was carried out for 3 seconds. Regarding the acidic aqueous solution used for the decontamination treatment, an aqueous solution of sulfuric acid at 150 g / L was used. Its liquid temperature was 30°C.

[0886] (Electrochemical roughening treatment)

[0887] Next, an electrolytic solution with a hydrochloric acid concentration of 13 g / L, an aluminum ion concentration of 15 g / L, and a sulfuric acid concentration of 1.0 g / L was used, and an electrochemical roughening treatment was carried out using an alternating current. It was carried out at a liquid temperature of 22°C of the electrolytic solution. Aluminum chloride was added to adjust the aluminum ion concentration.

[0888] The waveform of the alternating current was a sine wave with symmetric positive and negative waveforms, the frequency was 50 Hz, the anode reaction time and the cathode reaction time in one cycle of the alternating current were 1:1, and the current density was 35 A / dm based on the current peak value of the alternating current waveform 2 . And the electric charge was 300 C / dm based on the total electric charge of the aluminum plate participating in the anode reaction 2 , regarding the electrolytic treatment, with a power-on interval of 2.5 seconds, it was carried out 4 times at 75 C / dm 2 . A carbon electrode was used as the counter electrode for the aluminum plate. Then, a water washing treatment was carried out.

[0889] (Alkaline etching treatment)

[0890] At a temperature of 45°C, an etching treatment was carried out by spraying a caustic soda aqueous solution with a caustic soda concentration of 5 mass% and an aluminum ion concentration of 0.5 mass% onto the aluminum plate after the electrochemical roughening treatment. The dissolution amount of aluminum on the surface where the electrochemical roughening treatment was carried out was 0.2 g / m 2 . Then, a water washing treatment was carried out.

[0891] (Decontamination treatment using an acidic aqueous solution)

[0892] Next, a decontamination treatment was performed using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate with a sprayer, and a decontamination treatment was carried out for 3 seconds. As the acidic aqueous solution used for the decontamination treatment, an aqueous solution with a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L was used. Its liquid temperature was 35°C.

[0893] (First-stage anodizing treatment)

[0894] The first-stage anodizing treatment was carried out using a direct-current electrolytic anodizing device based on the structure shown in Figure 6 . At an electrolytic solution concentration of 150 g / L, a temperature of 50°C, and a current density of 15 A / dm 2An anodic oxidation treatment was carried out under the specified conditions to form an anodic oxidation film with a specified film thickness.

[0895] (Hole enlargement treatment)

[0896] The aluminum plate that had undergone the above anodic oxidation treatment was immersed in an aqueous sodium hydroxide solution at a temperature of 40°C, a sodium hydroxide concentration of 5% by mass, and an aluminum ion concentration of 0.5% by mass, and a hole enlargement treatment was carried out. Then, spray water washing was performed.

[0897] (Second-stage anodic oxidation treatment)

[0898] Using a direct current electrolysis anodic oxidation apparatus having the structure shown in Figure 6 a second-stage anodic oxidation treatment was carried out. An anodic oxidation film with a specified film thickness was formed by performing anodic oxidation treatment under the conditions of an electrolyte concentration of 150 g / L, a temperature of 50°C, and a current density of 30 A / dm 2 thereby producing an aluminum support.

[0899] (Formation of undercoat B)

[0900] An undercoat coating liquid having the following composition was coated on the support B so that the dry coating amount became 0.1 g / m 2 to form an undercoat B.

[0901] -Undercoat coating liquid-

[0902] ·Compound for undercoat (the following U-1, 11% aqueous solution): 0.0788 part

[0903] ·CHELEST 400 (chelating agent; manufactured by CHELEST CORPORATION): 0.0280 part

[0904] ·CHELEST 3EAF (chelating agent; manufactured by CHELEST CORPORATION): 0.0499 part

[0905] ·Surfactant (EMALEX (registered trademark) 710, manufactured by NIHON EMULSION Co., Ltd.): 0.00159 part

[0906] ·Preservative (Biohope L, K·I Chemical Industry Co., LTD.): 0.00149 part

[0907] ·Water: 2.8219 parts

[0908] (Formation of image recording layer B)

[0909] The coating liquid for the image recording layer B was bar-coated on the undercoat B and dried at 120 °C for 40 seconds to form an image recording layer B with a dry coating amount of 1.0 g / m 2 .

[0910] - Coating liquid for image recording layer B -

[0911] Infrared absorber (the above IR-1): 0.0200 parts

[0912] Infrared absorber (the above IR-2): 0.0050 parts

[0913] Color former (the above S-1): 0.0300 parts

[0914] Color former (the above S-2): 0.0120 parts

[0915] Onium-based polymerization initiator (the above I-1): 0.0981 parts

[0916] Borate compound (sodium tetraphenylborate (TPB)): 0.0270 parts

[0917] Polymerizable compound (the above M-4, 70%): 0.3536 parts

[0918] Polymer described in Table 3 below: Amount described in Table 3 (addition amount)

[0919] Anionic surfactant (the above A-1, 30%): 0.1620 parts

[0920] 2-Butanone: 5.3155 parts

[0921] 1-Methoxy-2-propanol: 2.8825 parts

[0922] Methanol: 2.3391 parts

[0923] The above microgel liquid 1: 2.8779 parts

[0924] <Formation of the outermost layer B (protective layer)>

[0925] The coating liquid for the protective layer was bar-coated on the image recording layer B and dried at 120 °C for 60 seconds to form the outermost layer (protective layer) B with a dry coating amount of 0.41 g / m 2 , thereby producing a lithographic printing plate precursor.

[0926] - Coating liquid for protective layer -

[0927] The following components were mixed to prepare the coating liquid for the protective layer.

[0928] Water: 1.0161 parts

[0929] METOLOSE SM04 (methyl cellulose, manufactured by Shin-Etsu Chemical Co., Ltd., degree of methoxy substitution = 1.8): 0.0600 parts

[0930] FS-102 (styrene-propylene resin, manufactured by Nipponpaint Industrial Coatings Co., Ltd., 1 g = 103 °C, 17% aqueous dispersion): 0.1177 parts by mass

[0931] RAPISOL A-80 (anionic surfactant, manufactured by NOF CORPORATION, 80% aqueous solution): 0.0063 parts

[0932] (Evaluation)

[0933] 1. Evaluation of planar appearance

[0934] <Evaluation of non-uniformity>

[0935] The original lithographic printing plate made was processed into 40 cm × 62 cm. The surface of the outermost layer of the obtained sample was visually observed under white light irradiation of 750 - 1500 Lux, and the planar appearance was evaluated according to the following criteria. The results are shown in Table 3.

[0936] - Criteria -

[0937] A: No non-uniformity was visually recognized on the entire surface.

[0938] B: Locally slight non-uniformity was visually recognized.

[0939] C: Locally slight non-uniformity was visually recognized in a wider area than B.

[0940] D: Slight non-uniformity was visually recognized on the entire surface.

[0941] E: Obvious non-uniformity was visually recognized on the entire surface.

[0942] <Evaluation of depression>

[0943] Regarding the original lithographic printing plates of Examples 17, 18, 26, 31, and 32 having the above image recording layer B in the original lithographic printing plates made, in addition to the evaluation of non-uniformity, the evaluation of depression was also carried out as the evaluation of planar appearance.

[0944] The original lithographic printing plates of Examples 17, 18, 26, 31, and 32 were processed into 15 cm × 62 cm. Under white light irradiation of 750 - 1500 Lux, the outermost layer side surfaces of 10 obtained samples were visually observed, and the total number of depressions generated on the coating surface was evaluated.

[0945] The fewer the number of depressions, the more excellent the coating surface state.

[0946] 2. Evaluation of on-press developability

[0947] Using Magnus800 Quantum manufactured by Kodak Company equipped with an infrared semiconductor laser, under the conditions of an output power of 27 W, an outer drum rotation speed of 450 rpm, and a resolution of 2,400 dpi (dots per inch, 1 inch is 2.54 cm), the original plate for lithographic printing was exposed (equivalent to an irradiation energy of 110 mJ / cm 2 ). The exposed original plate was installed on the drum of a printing press SX-74 manufactured by Heidelberger Druckmaschinen AG in the size of a chrysanthemum plate without developing. A dampening solution circulation tank with a capacity of 100 L equipped with a non-woven fabric filter and a temperature control device was connected to this printing press. 80 L of a 2.0% dampening solution S-Z1 (manufactured by Fujifilm Corporation) was filled into the circulation device, and T&K UV OFS K-HS ink GE-M (manufactured by T&K TOKA Corporation) was used as the printing ink. After supplying the dampening solution and the ink by the standard automatic printing start method, printing was performed on TOKUBISHI coated paper (continuous quantity: 76.5 kg, manufactured by Mitsubishi Paper Mills Limited) at a printing speed of 10,000 sheets per hour for 200 sheets. In the above on-press development, the number of sheets of printing paper required until the state where the ink does not transfer to the non-image area was obtained (hereinafter, also referred to as the on-press development number of sheets). It can be said that the fewer the on-press development number of sheets, the better the on-press developability. In the above on-press development, the number of sheets of printing paper required until the state where the ink does not transfer to the non-image area was obtained as the on-press developability. The fewer the above number of sheets, the better the on-press developability can be said. The results are shown in Tables 3 to 4.

[0948] [Table 3]

[0949]

[0950] [Table 4]

[0951]

[0952] (Examples 20 - 21, Comparative Examples 4 - 5)

[0953] <Support C>

[0954] A molten metal was prepared using an aluminum alloy containing Si: 0.06% by mass, Fe: 0.30% by mass, Cu: 0.014% by mass, Mn: 0.001% by mass, Mg: 0.001% by mass, Zn: 0.001% by mass, Ti: 0.03% by mass, with the balance being Al and unavoidable impurities. Based on molten metal treatment and filtration, an ingot with a thickness of 500 mm and a width of 1200 mm was produced by the DC casting method. After cutting the surface to an average thickness of 10 mm using a surface cutting machine, it was soaked and held at 550 °C for about 5 hours, and when the temperature was reduced to 400 °C, it was formed into a rolled plate with a thickness of 2.7 mm using a hot rolling mill. In addition, after heat treatment at 500 °C using a continuous annealing machine, it was finish-rolled into an aluminum plate with a thickness of 0.24 mm by cold rolling. After making the aluminum plate into a width of 1030 mm, the following surface treatment was carried out.

[0955] -Surface treatment-

[0956] The surface treatment was carried out by continuously performing the following various treatments (a) to (j). In addition, after each treatment and water washing, water removal was carried out using pinch rolls.

[0957] (a) Mechanical roughening treatment

[0958] While supplying a suspension of an abrasive (silica sand) with a specific gravity of 1.12 and water as a grinding slurry to the surface of the aluminum plate, mechanical roughening was carried out using a rotating drum-shaped nylon brush. The average particle size of the abrasive was 8 μm, and the maximum particle size was 50 μm. The material of the nylon brush was 6 / 10 nylon, the hair length was 50 mm, and the diameter of the hair was 0.3 mm. Regarding the nylon brush, holes were drilled in a stainless steel sleeve with a diameter of φ300 mm and the hair was implanted in a dense manner. Three rotating brushes were used. The distance between the two support rolls (φ200 mm) at the lower part of the brush was 300 mm. The brush roll was pressed until the load of the drive motor that rotates the brush increased by 7 kW compared to the load before pressing the brush roll against the aluminum plate. The rotation direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

[0959] (b) Etching treatment based on an alkaline agent

[0960] Using an aqueous solution with a caustic soda concentration of 2.6% by mass, an aluminum ion concentration of 6.5% by mass, and a temperature of 70 °C, the aluminum plate obtained above was etched by spraying, and 10 g / m 2 of the aluminum plate was dissolved. Then, spray water washing was carried out.

[0961] (c) Degreasing treatment

[0962] The decontamination treatment was carried out by spraying with an aqueous solution of nitric acid at a concentration of 1% by mass at a temperature of 30 °C (containing 0.5% by mass of aluminum ions). Then, water washing was carried out by spraying. The aqueous nitric acid solution used for decontamination was the waste liquid from the process of electrochemically roughening using alternating current in the aqueous nitric acid solution.

[0963] (d) Electrochemical roughening treatment

[0964] The electrochemical roughening treatment was continuously carried out using an alternating current voltage of 60 Hz. The electrolyte at this time was an aqueous solution of nitric acid at 10.5 g / L (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions), and the liquid temperature was 80 °C. The waveform of the alternating current power supply was Figure 3 the waveform shown, and a rectangular wave alternating current with a trapezoid shape with a time TP from zero to the peak value of the current of 0.8 msec, a duty ratio of 1:1 was used, and the electrochemical roughening treatment was carried out using a carbon electrode as the counter electrode. A ferrite was used as the auxiliary anode. The electrolytic cell used was Figure 4 the electrolytic cell shown. The current density was 30 A / dm based on the peak value of the current 2 , and the electric quantity was 220 C / dm based on the total electric quantity when the aluminum plate was used as the anode 2 . 5% of the current from the power supply was shunted to the auxiliary anode. Then, spray water washing was carried out.

[0965] (e) Alkali etching treatment

[0966] At 32 °C, an aqueous solution with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass was used to carry out etching treatment on the aluminum plate by spraying, dissolving 0.20 g / m 2 of the aluminum plate, removing the stain components mainly composed of aluminum hydroxide generated during the electrochemical roughening treatment using alternating current in the previous stage, and dissolving the edge part of the generated depression to smooth the edge part. Then, spray water washing was carried out.

[0967] (f) Decontamination treatment

[0968] The decontamination treatment based on a sprayer was carried out with an aqueous solution of nitric acid at a concentration of 25% by mass at a temperature of 30 °C (containing 0.5% by mass of aluminum ions), and then spray water washing was carried out.

[0969] (g) Anodizing treatment

[0970] An anodizing treatment was carried out using an anodizing apparatus with a two-stage power supply electrolysis treatment method (the lengths of the first and second electrolysis sections are each 6 m, the lengths of the first and second power supply sections are each 3 m, and the lengths of the first and second power supply electrodes are each 2.4 m). As the electrolytic solution supplied to the first electrolysis section and the second electrolysis section, sulfuric acid was used. The electrolytic solutions were both sulfuric acid with a concentration of 170 g / L (containing 0.5 mass% of aluminum ions), and the temperature was 43 °C. Then, spray water washing was carried out. The final amount of the oxide film was 2.7 g / m 2 。

[0971] (h) The aluminum support obtained by anodizing treatment was impregnated in a treatment layer of a 1 mass% aqueous solution of sodium silicate No. 3 at a temperature of 30 °C for 10 seconds, thereby performing alkali metal silicate treatment (silicate treatment). Then, spray water washing was carried out.

[0972] <Formation of undercoat C>

[0973] The coating liquid for the undercoat having the following composition was applied to the support C and dried at 80 °C for 15 seconds to form the undercoat C. The coating amount of the dried undercoat was 15 mg / m 2 。

[0974] -Coating liquid for undercoat-

[0975] · The following polymer compound 1: 0.3 part

[0976] · Methanol: 100 parts

[0977] · Water: 1 part

[0978] [Chemical formula 52]

[0979]

[0980] <Formation of image recording layer C1>

[0981] On the undercoat C, after applying the following coating liquid for the lower image recording layer so that the coating amount becomes 0.85 g / m 2 , it was dried at 140 °C for 50 seconds with the Wind Control set to 7 using a PERFECT OVEN PH200 manufactured by TABAI Corporation, and then, after applying the coating liquid for the upper image recording layer so that the coating amount becomes 0.15 g / m 2 , it was dried at 120 °C for 1 minute, thereby forming the image recording layer C1. Thus, the original lithographic printing plate of Example 20 and Comparative Example 4 was obtained.

[0982] -Coating liquid for lower recording layer-

[0983] · N-(4-sulfamoylphenyl)methacrylamide / acrylonitrile / methyl methacrylate copolymer (copolymerization ratio: 35 / 30 / 35; weight average molecular weight 50,000): 2.37 parts

[0984] · m,p-cresol novolac: 0.47 parts

[0985] · Cyanine dye A (structure below): 0.13 parts

[0986] · 4,4'-dihydroxyphenyl sulfone: 0.11 parts

[0987] · Tetrahydrophthalic anhydride: 0.15 parts

[0988] · p-toluenesulfonic acid: 0.01 parts

[0989] · 3-methoxy-4-diazodiphenylamine hexafluorophosphate: 0.03 parts · Compound in which the counter anion of crystal violet is replaced with naphthalene sulfonic acid: 0.10 parts

[0990] · Polymer described in Table 4 below: 0.035 parts

[0991] · Methyl ethyl ketone: 24 parts

[0992] · 2-methoxy-1-propanol: 13 parts

[0993] · γ-butyrolactone: 14 parts

[0994] -Coating liquid for upper image recording layer-

[0995] · m,p-cresol novolac: 0.285 parts

[0996] · Ethyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (copolymerization ratio: 50 / 20 / 30; weight average molecular weight 42,000): 0.06 parts

[0997] · Cyanine dye A (structure below): 0.075 parts

[0998] · Sulfonate A (structure below): 0.060 parts

[0999] · Polymer described in Table 4 below: 0.035 parts

[1000] · Methyl ethyl ketone: 15.1 parts

[1001] · 1-methoxy-2-propanol: 7.7 parts

[1002] [Chemical formula 53]

[1003]

[1004] <Image recording layer C2>

[1005] On the undercoat layer C, the following coating liquid for the image recording layer C2 was applied so that the coating amount became 1.3 g / m 2 After that, it was dried at 150 °C for 40 seconds with the Wind Control set to 7 using a PERFECT OVEN PH200 manufactured by TABAI Corporation, thereby forming the image forming layer C2. Thus, the original lithographic printing plates of Example 21 and Comparative Example 5 were obtained.

[1006] -Coating liquid for image recording layer C2-

[1007] · Novolak resin (m-cresol / p-cresol / phenol = 3 / 2 / 5, Mw 8,000): 3.5 parts

[1008] · Novolak resin having the following structure: 0.68 part

[1009] · Infrared absorber (the above cyanine dye A): 0.045 part

[1010] · Dye having the counter anion of ethyl violet as 6-hydroxy-β-naphthalene sulfonic acid: 0.15 part

[1011] · Bisphenol sulfone: 0.3 part

[1012] · Tetrahydrophthalic acid: 0.4 part

[1013] · Polymer described in Table 4 below: 0.02 part

[1014] · Methyl ethyl ketone: 30 parts

[1015] · Propylene glycol monomethyl ether: 15 parts

[1016] · γ-Butyrolactone: 15 parts

[1017] [Chemical formula 54]

[1018]

[1019] (Example 22, Comparative Example 6)

[1020] (Production of support D)

[1021] The following various treatments (a) to (e) were continuously performed using an aluminum plate (material 1050) with a thickness of 0.3 mm. In addition, after each treatment and water washing, the liquid was removed using a nip roll.

[1022] (Treatment (a))

[1023] In order to remove the rolling oil on the surface of an aluminum plate with a thickness of 0.3 mm (material: 1050), after performing degreasing treatment with a 10 mass% sodium aluminate aqueous solution at 50 °C for 30 seconds, three bundled nylon brushes with a hair bundle diameter of 0.3 mm and a pumice - water suspension with a median particle size of 30 μm (specific gravity 1.1 g / cm 3 ) were used to perform graining treatment on the aluminum surface at a brush rotation speed of 250 rpm, and then thoroughly washed with water.

[1024] (Treatment (b))

[1025] The plate was etched by immersing it in a 25% sodium hydroxide aqueous solution at 45 °C for 9 seconds, washed with water, and then further immersed in 20% nitric acid at 60 °C for 20 seconds and washed with water. The etching amount of the grained surface at this time was about 3 g / m 2 .

[1026] (Treatment (c))

[1027] Next, electrochemical roughening treatment was continuously performed using an alternating current voltage of 60 Hz. The electrolyte at this time was a 1 mass% nitric acid aqueous solution (containing 0.5 mass% of aluminum ions), and the liquid temperature was 50 °C. The alternating current power supply waveform used a rectangular trapezoidal wave alternating current with a time TP from zero to peak current value of 0.8 msec, a duty ratio of 1:1, and a carbon electrode was used as the counter electrode for the electrochemical roughening treatment. A 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 out from the power supply was shunted to the auxiliary anode. The amount of electricity in the nitric acid electrolysis was 175 C / dm 2 when the aluminum plate was the anode. Then, spray washing was performed.

[1028] (Treatment (d))

[1029] Next, an electrochemical roughening treatment was performed in the same method as the nitric acid electrolysis under the condition that the electrolyte was a 0.5 mass% hydrochloric acid aqueous solution (containing 0.5 mass% of aluminum ions), the liquid temperature was 50 °C, and the amount of electricity was 50 C / dm 2 when the aluminum plate was the anode, and then spray washing was performed.

[1030] (Treatment (e))

[1031] For this plate, 15% sulfuric acid (containing 0.5 mass% of aluminum ions) was used as the electrolyte, and a DC anodic oxide film of 2.5 g / m 2 was formed at a current density of 15 A / dm 2 , and then washed with water and dried to obtain support A. The center line average roughness (Ra) of this substrate was measured using a needle with a diameter of 2 μm, and the result was 0.51 μm.

[1032] Thus, the support D was produced.

[1033] <Formation of the undercoat layer D>

[1034] On the support D, the following coating liquid for the undercoat layer was coated so that the coating amount after drying became 5 mg / m 2 , and it was dried at 100 °C for 10 seconds to form the undercoat layer D.

[1035] - Coating liquid for the undercoat layer -

[1036] · Polymer compound a-1 (Mw: 35,000) having the following structure: 0.05 g

[1037] · Methanol: 27 g

[1038] · Ion-exchanged water: 3 g

[1039] [Chemical formula 55]

[1040]

[1041] <Image recording layer D>

[1042] On the undercoat layer D, a coating liquid for the image recording layer having the following composition was prepared and coated so that the coating amount after drying became 1.0 g / m 2 , and it was dried at 115 °C for 34 seconds using a hot air drying device to form the image recording layer D.

[1043] - Coating liquid for the image recording layer D -

[1044] · Infrared absorber (the following IR-1): 0.040 part

[1045] · Polymerization initiator A (the following S-1): 0.104 part

[1046] · Polymerization initiator B (the following I-1): 0.153 part

[1047] · Mercapto compound (the following SH-1): 0.038 part

[1048] · Sensitizing auxiliary agent (the following T-1): 0.121 part

[1049] · Polymerizable compound (the following M-1): 0.535 part

[1050] · Urethane-based binder polymer A (the following polyurethane resin (P-1), Mw: 100000): 0.107 part

[1051] · Acrylic binder polymer B (the following acrylic resin B-1, Mw: 100,000): 0.267 parts

[1052] · Acrylic binder polymer C (the following acrylic resin C-1, Mw: 100,000): 0.160 parts

[1053] · Copper phthalocyanine pigment dispersion: 0.775 parts

[1054] (C.I.Pigmeent Blue 15:6, dispersion solvent: MEK / MF parts / MA = 2 / 2 / 1, pigment solid content 15 wt%)

[1055] · Polymerization inhibitor (the following Q-1): 0.0015 parts

[1056] · Polymer described in Table 5 below: 0.02 parts

[1057] · Methyl ethyl ketone: 6.481 parts

[1058] · Methanol: 2.738 parts

[1059] · 1-Methoxy-2-propanol: 5.119 parts

[1060] [Chemical formula 56]

[1061]

[1062] [Chemical formula 57]

[1063]

[1064] [Chemical formula 58]

[1065]

[1066] [Chemical formula 59]

[1067]

[1068] [Chemical formula 60]

[1069] Acrylic resin B-1

[1070]

[1071] Acrylic resin C-1

[1072]

[1073] <Formation of the outermost layer (protective layer) D>

[1074] A mixed aqueous solution (coating solution for the lower protective layer) of synthetic mica (SOMASIF MEB-3L, 3.2% aqueous dispersion, manufactured by Co-op Chemical Co., Ltd.), polyvinyl alcohol (GOHSERAN CKS-50: saponification degree 99 mol%, polymerization degree 300, sulfonic acid-modified polyvinyl alcohol manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), surfactant A (manufactured by Nihon Emulsion Co., Ltd., EMALEX 710), and surfactant B (ADEKA PLURONIC (registered trademark) P-84: manufactured by ADEKA CORPORATION) was coated on the image recording layer D, and dried at 125°C for 30 seconds using a hot air drying device. The content ratio of synthetic mica (solid content) / polyvinyl alcohol / surfactant A / surfactant B in the mixed aqueous solution (coating solution for the lower protective layer) was 7.5 / 89 / 2 / 1.5 (parts by mass), and the coating amount (coating amount after drying) was 0.5 g / m 2 .

[1075] An organic filler (ART PEARL J-7P, manufactured by Negami Chemical Industrial Co., Ltd.), synthetic mica (SOMASIF MEB-3L, 3.2% aqueous dispersion, manufactured by Co-op Chemical Co., Ltd.), polyvinyl alcohol (L-3266: saponification degree 87 mol%, polymerization degree 300, sulfonic acid-modified polyvinyl alcohol manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), thickener (CELLOGEN FS-B, manufactured by DKS Co., Ltd.), polymer compound A (the following structure), and surfactant (manufactured by Nihon Emulsion Co., Ltd., EMALEX 710) were coated on the obtained lower protective layer as a mixed aqueous solution (coating solution for the upper protective layer), and dried at 125°C for 30 seconds using a hot air drying device. The content ratio of the organic filler / synthetic mica (solid content) / polyvinyl alcohol / thickener / polymer compound A / surfactant in the mixed aqueous solution (coating solution for the upper protective layer) was 4.7 / 2.8 / 67.4 / 18.6 / 2.3 / 4.2 (parts by mass), and the coating amount (coating amount after drying) was 1.8 g / m 2 .

[1076] [Chemical formula 61]

[1077]

[1078] (Example 23, Comparative Example 7)

[1079] <Fabrication of Support E>

[1080] For an aluminum plate of Material 1S with a thickness of 0.30 mm, after surface graining treatment using an 8 - numbered nylon brush and an aqueous suspension of pumice with a mesh size of 800, it was thoroughly washed with water. After etching in 10% sodium hydroxide at 70 °C for 60 seconds, it was washed with running water, then neutralized and washed with 20% HNO₃. Under the condition of VA = 12.7 V, electrolytic roughening treatment was carried out using an alternating waveform current of a sine wave in a 1% nitric acid aqueous solution with an anodic charge of 300 coulombs / dm 2 The measured surface roughness was 0.45 μm (expressed as Ra). Subsequently, it was immersed in a 30% H₂SO₄ aqueous solution, degreased at 55 °C for 2 minutes, and then in a 20% H₂SO₄ aqueous solution at 33 °C. A cathode was placed on the grained surface, and anodic oxidation was carried out at a current density of 5 A / dm 2 for 50 seconds, and as a result, the thickness was 2.6 g / m 2 . This was used as Support E.

[1081] <Formation of Undercoat E>

[1082] On Support E, the following undercoat coating liquid was coated using a bar coater so that the coating amount after drying would be 2 mg / m 2 , and it was dried at 80 °C for 20 seconds to form Undercoat E.

[1083] - Undercoat Coating Liquid -

[1084] · Polymer (the following structure): 0.3 parts

[1085] · Pure water: 60.0 parts

[1086] · Methanol: 939.7 parts

[1087] [Chemical formula 62]

[1088]

[1089] <Image Recording Layer E>

[1090] On Undercoat E, the following image recording layer E coating liquid was coated using a bar coater so that the coating amount after drying would be 1.35 g / m 2 , and it was dried at 90 °C for 1 minute to form Image Recording Layer E.

[1091] - Image Recording Layer E Coating Liquid -

[1092] · PLEX6661 - O manufactured by Degussa AG: 1.69 parts

[1093] · Adhesive polymer PP - 3 (the following structure): 1.87 parts

[1094] · Sensitizing dye D40 (the following structure): 0.13 parts

[1095] · BIMD (Hexaarylbisimidazole manufactured by KUROGANE KASEI Co., Ltd.): 0.46 parts

[1096] · ε - phthalocyanine (the following F - 1) dispersion (25% MEK dispersion): 1.70 parts

[1097] · Mercapto - containing heterocyclic compound SH - 8 (the following structure): 0.34 parts

[1098] · Polymer described in Table 5 below: 0.03 parts

[1099] · Cupferron AL (10% solution of tricresyl phosphate manufactured by FUJIFILM Wako Pure Chemical Corporation): 0.12 parts

[1100] · Methyl ethyl ketone: 27.0 parts

[1101] · Propylene glycol monomethyl ether: 26.7 parts

[1102] · S - 2358 Yellow (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.): 0.50 parts

[1103] [Chemical formula 63]

[1104]

[1105] [Formation of the outermost layer (protective layer) E]

[1106] On the image recording layer E, the following aqueous solution for the protective layer was coated with a bar coater so that the coating amount after drying became 2.5 g / m 2 , and it was dried at 120 °C for 1 minute to form the outermost layer (protective layer) E.

[1107] - Aqueous solution for the protective layer -

[1108] · PVA105 (saponification degree 98 mol%, manufactured by KURARAY CO., LTD.): 1.80 parts

[1109] · Polyvinylpyrrolidone: 0.40 parts

[1110] · EMALEX 710 (a nonionic surfactant manufactured by Nippon Nyukazai Co., Ltd.): 0.04 parts

[1111] · PIONIN D230 (a surfactant manufactured by Takemoto Oil & Fat Co., Ltd.): 0.05 parts

[1112] · Luviskol V64W (manufactured by BASF): 0.06 parts

[1113] · 13% aqueous solution of a sulfonic acid group-containing polymer having the following structure: 0.36 parts

[1114] · Pure water: 36.0 parts

[1115] [Chemical formula 64]

[1116]

[1117] (Example 24, Comparative Example 8)

[1118] <Fabrication of Support F>

[1119] The following surface treatment was performed using an aluminum plate (JIS A1050) with a thickness of 0.03 mm.

[1120] (Electrochemical roughening treatment)

[1121] The electrochemical roughening treatment was continuously performed using an alternating current voltage of 60 Hz. The electrolyte at this time was a 10.5 g / L aqueous solution of nitric acid (containing 5 g / L aluminum ions and 0.007 mass% ammonium ions), and the liquid temperature was 50°C. The time TP from zero to the peak value of the current was 0.8 msec, the duty ratio was 1:1, a trapezoidal rectangular wave alternating current was used, and the electrochemical roughening treatment was performed using a carbon electrode as the counter electrode. A ferrite was used as the auxiliary anode. A radial cell type electrolytic cell was used. The current density was 30 A / dm based on the peak value of the current 2 and the amount of electricity was 220 C / dm based on the total amount of electricity when the aluminum plate was used as the anode 2 . 5% of the current from the power supply was shunted to the auxiliary anode. Then, spray washing was performed.

[1122] (Alkali etching treatment)

[1123] At 32°C, an aqueous solution with a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass% was used to etch the aluminum plate by spraying, and 0.50 g / m was dissolved 2The aluminum plate was treated to remove stain components mainly composed of aluminum hydroxide generated during electrochemical roughening with alternating current in the previous stage, and the edge portions of the generated depressions were dissolved to smooth the edge portions. Then, spray washing was performed.

[1124] (Stain removal treatment)

[1125] Stain removal treatment was carried out by spraying with an aqueous solution of sulfuric acid at a concentration of 15% by mass (containing 4.5% by mass of aluminum ions) at a temperature of 30 °C, and then washing was carried out by spraying.

[1126] (Electrochemical roughening treatment)

[1127] Electrochemical roughening treatment was continuously carried out using an alternating current voltage of 60 Hz. The electrolytic solution at this time was an aqueous solution of hydrochloric acid at 5.0 g / L (containing 5 g / L of aluminum ions), and the temperature was 35 °C. The time TP from zero to the peak value of the current value used was 0.8 msec, the duty ratio was 1:1, a trapezoidal rectangular wave alternating current was used, and the electrochemical roughening treatment was carried out using a carbon electrode as the counter electrode. A ferrite was used as the auxiliary anode. A chamber-type electrolytic cell was used. The current density was 25 A / dm based on the current peak value 2 , and the electric quantity was 50 C / dm based on the total electric quantity when the aluminum plate was used as the anode 2 . Then, spray washing was performed.

[1128] (Anodizing treatment)

[1129] Anodizing treatment was carried out using an anodizing device with a two-stage power supply electrolysis treatment method (the lengths of the first and second electrolysis parts were each 6 m, the lengths of the first and second power supply parts were each 3 m, and the lengths of the first and second power supply electrodes were each 2.4 m). The electrolytic solutions supplied to the first and second electrolysis parts were both sulfuric acid at a concentration of 50 g / L (containing 0.5% by mass of aluminum ions), and the temperature was 20 °C. Then, spray washing was performed. The final oxide film amount was 2.7 g / m 2 .

[1130] (Hydrophilic treatment)

[1131] The aluminum plate was immersed in a treatment solution at 53 °C in which 0.4% by mass of polyvinylphosphonic acid (manufactured by PCAS Corporation) was dissolved in pure water for 10 seconds, and the remaining treatment solution was removed using a pinch roll. Then, it was washed with well water at 60 °C with a calcium ion concentration of 20 - 400 ppm for 4 seconds, further washed with pure water at 25 °C for 4 seconds, and the remaining pure water was removed using a pinch roll. In the subsequent drying process, the moisture on the aluminum plate was completely removed.

[1132] The center line average roughness of the obtained support F (expressed as Ra based on JIS B0601) was measured using a needle with a diameter of 2 μm, and the result was 0.28 μm.

[1133] <Formation of the image recording layer F>

[1134] On the support F, a coating liquid for the image recording layer F having the following composition was coated in such a manner that the dry coating mass became 1.4 g / m 2 and dried at 100 °C for 1 minute to form the image recording layer F.

[1135] -Coating liquid for the image recording layer F-

[1136] · Polymerizable compound (Compound A): 4.0 parts

[1137] · Binder polymer (Binder A) (Mw = 50000): 2.0 parts

[1138] · Sensitizing dye (C-1): 0.32 part

[1139] · Polymerization initiator (D-1): 0.61 part

[1140] · Chain transfer agent (E-1): 0.57 part

[1141] · Aluminum salt of N-nitrosophenylhydroxylamine: 0.020 part

[1142] · Dispersion of ε-phthalocyanine pigment (F1): 0.71 part

[1143] (Pigment: 15 parts, dispersant the following polymer (1): 10 parts)

[1144] · Solvent: cyclohexanone / methoxypropyl acetate / 1-methoxy-2-propanol = 15 parts / 20 parts / 40 parts

[1145] · Polymer described in Table 5 below: 0.016 part

[1146] · Methyl ethyl ketone: 47 parts

[1147] · Propylene glycol monomethyl ether: 45 parts

[1148] [Chemical formula 65]

[1149]

[1150] <Formation of the outermost layer (protective layer) F>

[1151] On the image recording layer F, the coating amount after drying was made to be 25 g / m 2After bar coating a coating liquid for a protective layer composed of the following composition and then drying at 125°C for 70 seconds, the outermost layer (protective layer) F was formed.

[1152] - Coating liquid for protective layer -

[1153] · The following mica dispersion: 0.6 g

[1154] · Sulfonic acid-modified polyvinyl alcohol (GOHSERAN CKS-50, manufactured by Nippon Synthetic Chemical Industry Co., Ltd. (saponification degree: 99 mol%, average degree of polymerization: 300, modification degree: about 0.4 mol%)): 0.8 g

[1155] · Poly(vinylpyrrolidone / vinyl acetate (1 / 1)) (molecular weight: 70,000): 0.001 g

[1156] · Surfactant (EMALEX (registered trademark) 710, manufactured by NIHON EMULSION Co., Ltd.): 0.002 g

[1157] · Water: 13 g

[1158] (Mica dispersion)

[1159] To 368 g of water, 32 g of synthetic mica (SOMASIF ME-100, manufactured by Co-op Chemical Co., Ltd., aspect ratio: 1000 or more) was added, and it was dispersed using a homogenizer until the average particle size (laser scattering method) became 0.5 μm, thereby obtaining a mica dispersion.

[1160] (Evaluation)

[1161] 1. Evaluation of flatness

[1162] The original lithographic printing plate produced was processed into 40 cm × 62 cm. The surface on the outermost layer side of the obtained sample was visually observed under white light irradiation of 750 - 1500 Lux, and the flatness was evaluated according to the following criteria. The results are shown in Table 5.

[1163] - Criteria -

[1164] A: No unevenness was visually recognized on the entire surface.

[1165] B: Locally slight unevenness was visually recognized.

[1166] C: Slight unevenness was visually recognized on the entire surface.

[1167] D: Obvious unevenness was visually recognized on the entire surface.

[1168] [Table 5]

[1169]

[1170] (Examples 27 and 28)

[1171] <Support G>

[1172] The support G was manufactured by subjecting an aluminum plate (aluminum alloy plate) of Material 1S with a thickness of 0.3 mm to the following treatments (J-a) to (J-m). In addition, a water washing treatment was carried out between all treatment steps, and drainage was performed by a pinch roll after the water washing treatment.

[1173] (J-a) Mechanical roughening treatment (brush streak method)

[1174] Using the device as Figure 5 shown, while supplying a pumice suspension (specific gravity 1.1 g / cm 3 ) as a grinding slurry to the surface of the aluminum plate, mechanical roughening treatment was carried out by a rotating hard hair bundle brush. In Figure 5 , 1 is the aluminum plate, 2 and 4 are drum-shaped brushes (hard hair bundle brushes in this embodiment), 3 is the grinding slurry, and 5, 6, 7, and 8 are support rolls.

[1175] In the mechanical roughening treatment, the median particle size (μm) of the abrasive was set to 30 μm, the number of brushes was set to 4, and the brush rotation speed (rpm) was set to 250 rpm. The material of the hard hair bundle brush is 6 / 10 nylon, the diameter of the bristles is 0.3 mm, and the hair length is 50 mm. Regarding the brush, holes were drilled in a stainless steel casing with a diameter of φ300 mm and the hair was densely planted. The distance between the two support rolls (φ200 mm) at the lower part of the hard hair bundle brush is 300 mm. The hard hair bundle brush was pressed until the load of the drive motor for rotating the brush increased by 10 kW relative to the load before pressing the hard hair bundle brush against the aluminum plate. The rotation direction of the brush is the same as the moving direction of the aluminum plate.

[1176] (J-b) Alkali etching treatment

[1177] At a temperature of 70 °C, a caustic soda aqueous solution with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass was sprayed onto the aluminum plate using a sprayer to carry out the etching treatment. The amount of aluminum dissolved on the surface for subsequent electrochemical roughening treatment was 10 g / m 2 .

[1178] (J-c) Cleaning treatment using an acidic aqueous solution

[1179] The waste liquid of nitric acid used in the subsequent electrochemical roughening treatment at a liquid temperature of 35 °C was used as the acidic aqueous solution, and the aluminum plate was sprayed with the acidic aqueous solution for 3 seconds using a sprayer for cleaning treatment.

[1180] (J-d) Electrochemical roughening treatment using an aqueous nitric acid solution

[1181] The electrochemical roughening treatment was continuously carried out using an alternating current voltage of 60 Hz. As the electrolyte, an electrolyte solution with a liquid temperature of 35 °C was used, which was prepared by adding aluminum nitrate to an aqueous solution of 10.4 g / L of nitric acid to adjust the aluminum ion concentration to 4.5 g / L. The waveform of the alternating current power supply was Figure 3 the waveform shown. Using a rectangular wave alternating current with a trapezoidal shape, where the time tp from zero to the peak value of the current is 0.8 msec, a duty ratio of 1:1, the carbon electrode was used as the counter electrode to carry out the electrochemical roughening treatment. The auxiliary anode used was ferrite. The electrolytic cell used was Figure 4 the electrolytic cell shown. The current density was 30 A / dm based on the peak value of the current 2 , and 5% of the current flowing out from the power supply was shunted to the auxiliary anode. The quantity of electricity (C / dm 2 ) was 185 C / dm based on the total quantity of electricity when the aluminum plate was used as the anode 2 .

[1182] (J-e) Alkali etching treatment

[1183] An aqueous caustic soda solution with a caustic soda concentration of 27% by mass and an aluminum ion concentration of 2.5% by mass was sprayed onto the aluminum plate at a temperature of 50 °C using a sprayer to carry out the etching treatment. The amount of aluminum dissolved was 3.5 g / m 2 .

[1184] (J-f) Detergent treatment using an acidic aqueous solution

[1185] An aqueous solution with a liquid temperature of 30 °C, a sulfuric acid concentration of 170 g / L, and an aluminum ion concentration of 5 g / L was used as the acidic aqueous solution, and the aluminum plate was sprayed with it using a sprayer for 3 seconds to carry out the detergent treatment.

[1186] (J-g) Electrochemical roughening treatment using an aqueous hydrochloric acid solution

[1187] The electrochemical roughening treatment was continuously carried out using an alternating current voltage of 60 Hz. As the electrolyte, an electrolyte solution with a liquid temperature of 35 °C was used, which was prepared by adding aluminum chloride to an aqueous solution of 6.2 g / L of hydrochloric acid to adjust the aluminum ion concentration to 4.5 g / L. The waveform of the alternating current power supply was Figure 3 the waveform shown. Using a rectangular wave alternating current with a trapezoidal shape, where the time tp from zero to the peak value of the current is 0.8 msec, a duty ratio of 1:1, the carbon electrode was used as the counter electrode to carry out the electrochemical roughening treatment. The auxiliary anode used was ferrite. The electrolytic cell used was Figure 4 the electrolytic cell shown. The current density was 25 A / dm based on the peak value of the current 2 , and the quantity of electricity (C / dm 2)The total amount of electricity when the aluminum plate is used as the anode is counted as 63 C / dm 2 .

[1188] (J-h) Caustic etching treatment

[1189] Caustic soda aqueous solution with a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass was sprayed onto the aluminum plate using a sprayer at a temperature of 60 °C for etching treatment. The amount of aluminum dissolved was 0.2 g / m 2 .

[1190] (J-i) Degreasing treatment using an acidic aqueous solution

[1191] The aqueous solution of the waste liquid (sulfuric acid concentration 170 g / L and aluminum ion concentration 5 g / L) generated in the anodizing treatment process at a liquid temperature of 35 °C was used as the acidic aqueous solution, and the aluminum plate was sprayed for 4 seconds using a sprayer for degreasing treatment.

[1192] (J-j) First-stage anodizing treatment

[1193] The first-stage anodizing treatment was carried out using a direct current electrolysis anodizing device based on the structure shown in Figure 6 . Using a 170 g / L sulfuric acid aqueous solution as the electrolyte, anodizing treatment was carried out under the conditions of a liquid temperature of 50 °C and a current density of 30 A / dm 2 , and an anodized film with a film amount of 0.3 g / m 2 was formed.

[1194] (J-k) Hole expansion treatment

[1195] The aluminum plate that had been anodized was immersed in a caustic soda aqueous solution with a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass at 40 °C for 3 seconds for hole expansion treatment.

[1196] (J-l) Second-stage anodizing treatment

[1197] The second-stage anodizing treatment was carried out using a direct current electrolysis anodizing device based on the structure shown in Figure 6 . Using a 170 g / L sulfuric acid aqueous solution as the electrolyte, anodizing treatment was carried out under the conditions of a liquid temperature of 50 °C and a current density of 13 A / dm 2 , and an anodized film with a film amount of 2.6 g / m 2 was formed.

[1198] (J-m) Hydrophilic treatment

[1199] To ensure the hydrophilicity of the non-image part, the aluminum plate was immersed in a 2.5% by mass aqueous solution of sodium silicate No. 3 at 50 °C for 7 seconds for silicate treatment. The amount of Si attached was 8.5 mg / m2 The average diameter of the micropores is 30 nm.

[1200] The value of lightness L* in the L*a*b* color system on the anodic oxide film surface of the support G is 72.3.

[1201] The amount of the anodic oxide film of the support G is 2.6 g / m 2 .

[1202] <Formation of the undercoat G>

[1203] On the support G obtained above, an undercoat coating solution G having the following composition was coated so that the dry coating amount became 26 mg / m 2 , and thus the undercoat G was formed.

[1204] (Undercoat coating solution G)

[1205] · Compound (2) for undercoat (the following structure): 0.13 part

[1206] · Hydroxyethyliminodiacetic acid: 0.05 part

[1207] · Tetrasodium ethylenediaminetetraacetate: 0.05 part

[1208] · Polyoxyethylene lauryl ether: 0.03 part

[1209] · Water: 61.39 parts

[1210] [Chemical formula 66]

[1211]

[1212] <Formation of the image recording layer G>

[1213] On the undercoat G, a coating solution for the image recording layer G having the following composition was bar-coated and dried at 100 °C for 60 seconds to form an image recording layer G having a thickness of 1.2 μm.

[1214] The coating solution for the image recording layer G was obtained by mixing the following photosensitive solution G and the microgel solution (1) and stirring them immediately before coating.

[1215] (Photosensitive solution G)

[1216] · 23 mass% 1-methoxy-2-propanol solution of binder polymer (1) (the following structure): 0.3750 part

[1217] · 23 mass% 1-methoxy-2-propanol solution of binder polymer (2) (the following structure): 0.3834 part

[1218] · Infrared absorber (1) (the following structure): 0.0185 part

[1219] · Borate compound (1) (sodium tetraphenylborate): 0.0040 parts

[1220] · Polymerization initiator (1) (the following structure): 0.1250 parts

[1221] · Polymerizable compound (1) (tris(acryloyloxyethyl) isocyanurate, NK ester A - 9300 40% 2 - butanone solution, manufactured by SHIN - NAKAMURA CHEMICAL Co., Ltd.): 0.2050 parts

[1222] · Low - molecular - weight hydrophilic compound (1) (tris(2 - hydroxyethyl) isocyanurate): 0.0287 parts

[1223] · Low - molecular - weight hydrophilic compound (2) (trimethylglycine): 0.0147 parts

[1224] · 30 mass% aqueous solution of anionic surfactant 1 (the following structure): 0.240 parts

[1225] · Ultraviolet absorber (1) (TINUVIN 405, manufactured by BASF) (the following structure): 0.040 parts

[1226] · Polymer P - 14 (the above structure): 0.004 parts

[1227] · Phosphonium compound (1) (the following structure): 0.025 parts

[1228] · Ammonium - containing polymer (1) (the following structure, inherent viscosity 44 ml / g): 0.030 parts

[1229] · Benzyl dimethyl octyl ammonium·PF6 salt: 0.023 parts

[1230] · 2 - Butanone: 5.391 parts

[1231] · 1 - Methoxy - 2 - propanol: 3.154 parts

[1232] · Methanol: 1.117 parts

[1233] (Microgel solution (1))

[1234] · Microgel (1) (solid - content concentration 21.8 mass%): 2.243 parts

[1235] · 1 - Methoxy - 2 - propanol: 0.600 parts

[1236] (Preparation of microgel (1))

[1237] The preparation method of the microgel (1) used in the above microgel solution (1) is shown below.

[1238] <Preparation of polyisocyanate compound (1)>

[1239] To a suspension solution of 17.78 parts (80 molar equivalents) of isophorone diisocyanate and 7.35 parts (20 molar equivalents) of the following polyhydric phenol compound (1) in 25.31 parts of ethyl acetate was added 0.043 part of bismuth tris(2-ethylhexanoate) (NEOSTANN U-600, manufactured by NITT0 KASEI CO., LTD.), and the mixture was stirred. When heat generation was suppressed, the reaction temperature was set at 50 °C, and the mixture was stirred for 3 hours to obtain an ethyl acetate solution (50% by mass) of polyisocyanate compound (1).

[1240] [Chemical formula 67]

[1241]

[1242] <Preparation of microgel (1)>

[1243] The following oil phase components and water phase components were mixed and emulsified at 12,000 rpm for 10 minutes using a homogenizer. After the obtained emulsion was stirred at 45 °C for 4 hours, 5.20 parts of a 10% by mass aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-ene-octylate (U-CAT SA102, manufactured by San-Apro Ltd.) was added, and the mixture was stirred at room temperature for 30 minutes and then allowed to stand at 45 °C for 24 hours. The solid component concentration was adjusted with distilled water to 21.8% by mass to obtain an aqueous dispersion of microgel (1). As a result of measuring the volume average particle diameter by the light scattering method using a dynamic light scattering type particle size distribution measuring device LB-500 (manufactured by HORIBA, LTD.), it was 0.28 μm.

[1244] (Oil phase components)

[1245] (Component 1) Ethyl acetate: 12.0 parts

[1246] (Component 2) An adduct obtained by adding trimethylolpropane (6 moles) and xylylene diisocyanate (18 moles) and adding a methyl side chain polyoxyethylene (1 mole, number of repeating units of ethylene oxide unit: 90) thereto (50% by mass ethyl acetate solution, manufactured by Mitsui Chemicals, Inc.): 3.76 parts

[1247] (Component 3) Polyisocyanate compound (1) (as a 50% by mass ethyl acetate solution): 15.0 parts

[1248] (Component 4) 65% by mass ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer Company, Inc.): 11.54 parts

[1249] (Component 5) 10% ethyl acetate solution of sulfonate surfactant (PIONIN A-41-C, manufactured by TAKEMOTO OIL&FAT Co., Ltd.): 4.42 parts

[1250] (Aqueous phase component)

[1251] Distilled water: 46.87 parts

[1252] <Synthesis of Adhesive Polymer (1)>

[1253] Weigh 1-methoxy-2-propanol: 78.0 g in a three-necked flask and heat it to 70 °C under a nitrogen stream. To this reaction vessel, a mixed solution composed of BLEMMER PME-100 (methoxydiethylene glycol monomethacrylate, manufactured by NOF CORPORATION): 52.1 g, methyl methacrylate: 21.8 g, methacrylic acid: 14.2 g, dipentaerythritol hexakis(3-mercaptopropionate): 2.15 g, V-601 (2,2'-azobis(2-methylpropionitrile), manufactured by Wako Pure Chemical Industries, Ltd.): 0.38 g, and 1-methoxy-2-propanol: 54 g was added dropwise over 2 hours and 30 minutes. After the dropwise addition was completed, the temperature was raised to 80 °C, and the reaction was continued for 2 hours. A mixed solution composed of V-601: 0.04 g and 1-methoxy-2-propanol: 4 g was added, and the temperature was raised to 90 °C and the reaction was continued for 2.5 hours. After the reaction was completed, the reaction solution was cooled to room temperature.

[1254] To the above reaction solution, 1-methoxy-2-propanol: 137.2 g, 4-hydroxy-TEMPO: 0.24 g, glycidyl methacrylate: 26.0 g, and tetraethylammonium bromide: 3.0 g were added, stirred well, and then heated at 90 °C.

[1255] After 18 hours, the reaction solution was cooled to room temperature (25 °C), and then diluted by adding 1-methoxy-2-propanol: 99.4 g.

[1256] In the adhesive polymer (1) thus obtained, the solid content concentration: 23% by mass, and the polystyrene-reduced weight average molecular weight measured by GPC is 35,000.

[1257] [Chemical formula 68]

[1258]

[1259] <Synthesis of Adhesive Polymer (2)>

[1260] Weighed 78.00 g of 1-methoxy-2-propanol in a three-necked flask and heated it to 70 °C under a nitrogen stream. A mixed solution composed of 65.8 g of BLEMMER PME-100 (methoxydiethylene glycol monomethacrylate, manufactured by NOF CORPORATION), 28.4 g of methyl methacrylate, 2.8 g of methacrylic acid, 6.4 g of dipentaerythritol hexa(3-mercaptopropionate), 1.1 g of V-601 (2,2'-azobis(2-methylpropionitrile), manufactured by Wako Pure Chemical Industries, Ltd.), and 55 g of 1-methoxy-2-propanol was added dropwise to the reaction vessel over 2 hours and 30 minutes. After the addition was completed, the temperature was raised to 80 °C, and the reaction was continued for 2 hours. After 2 hours, a mixed solution composed of 0.11 g of V-601 and 1 g of 1-methoxy-2-propanol was added, and the temperature was raised to 90 °C and the reaction was continued for 2.5 hours. After the reaction was completed, the reaction solution was cooled to room temperature.

[1261] 177.2 g of 1-methoxy-2-propanol, 0.28 g of 4-hydroxy-TEMPO, 46.0 g of glycidyl methacrylate, and 3.4 g of tetrabutylammonium bromide were added to the above reaction solution, stirred evenly, and then heated at 90 °C.

[1262] After 18 hours, the reaction solution was cooled to room temperature (25 °C), and then 0.06 g of 4-methoxyphenol and 114.5 g of 1-methoxy-2-propanol were added for dilution.

[1263] In the adhesive polymer (2) thus obtained, the solid content concentration was 23% by mass, and the polystyrene-reduced weight average molecular weight measured by GPC was 50,000.

[1264] [Chemical Formula 69]

[1265]

[1266] <Formation of Image Recording Layer H>

[1267] The coating solution for the image recording layer H having the following composition was bar-coated on the undercoat layer G and dried at 100 °C for 60 seconds to form an image recording layer H with a thickness of 1.2 μm.

[1268] The coating solution for the image recording layer H was obtained by mixing the following photosensitive solution H and the microgel solution (1) immediately before coating and stirring.

[1269] (Photosensitive Liquid H)

[1270] · 23 mass% 1-methoxy-2-propanol solution of binder polymer (1) (the above structure): 0.2891 parts

[1271] · 23 mass% 1-methoxy-2-propanol solution of binder polymer (3) (the following structure): 0.4574 parts

[1272] · Infrared absorber (1) (the following structure): 0.0278 parts

[1273] · Borate compound (1) (sodium tetraphenylborate): 0.015 parts

[1274] · Polymerization initiator (1) (the following structure): 0.2348 parts

[1275] · Polymerizable compound (1) (tris(acryloyloxyethyl) isocyanurate, NK ester A-930 40% 2-butanone solution, manufactured by SHIN-NAKAMURA CHEMICAL Co., Ltd.): 0.2875 parts

[1276] · Low molecular weight hydrophilic compound (1) (tris(2-hydroxyethyl) isocyanurate): 0.0287 parts

[1277] · Low molecular weight hydrophilic compound (2) (trimethylglycine): 0.0147 parts

[1278] · 130 mass% aqueous solution of anionic surfactant (the following structure): 0.25 parts

[1279] · Ultraviolet absorber (1) (TINUVIN 405, manufactured by BASF) (the following structure): 0.04 parts

[1280] · Polymer P-14 (the above structure): 0.004 parts

[1281] · Phosphorus compound (1) (the following structure): 0.020 parts

[1282] · 2-butanone: 5.346 parts

[1283] · 1-methoxy-2-propanol: 3.128 parts

[1284] · Methanol: 0.964 parts

[1285] · Pure water: 0.036 parts

[1286] (Microgel Liquid (1))

[1287] · Microgel (1) (solid component concentration 21.8 mass%): 2.345 parts

[1288] · 1-Methoxy-2-propanol: 0.655 parts

[1289] (Production of Microgel (1))

[1290] The above microgel (1) was produced in the same manner as the microgel (1) used in the coating liquid for the image recording layer G.

[1291] (Synthesis of Binder Polymer (3))

[1292] Weighed 78.00 g of 1-methoxy-2-propanol in a three-necked flask and heated it to 70 °C under a nitrogen stream. Over a period of 2 hours and 30 minutes, a mixed solution composed of BLEMMER PME-100 (methoxydiethylene glycol monomethacrylate, manufactured by Nippon Oil and Fats Company, Limited): 52.8 g, methyl methacrylate: 2.8 g, methacrylic acid: 25.0 g, hexakis(3-mercaptopropionic acid) dipentaerythritol ester: 6.4 g, V-601 (2,2'-azobis(2-methylpropionitrile), manufactured by Wako Pure Chemical Industries, Ltd.): 1.1 g, and 1-methoxy-2-propanol: 55 g was added dropwise to the reaction vessel. After the addition was completed, the temperature was raised to 80 °C, and the reaction was continued for 2 hours. After 2 hours, a mixed solution composed of V-601: 0.11 g and 1-methoxy-2-propanol: 1 g was added, and the temperature was raised to 90 °C and the reaction was continued for 2.5 hours. After the reaction was completed, the reaction solution was cooled to room temperature.

[1293] To the above reaction solution, 177.2 g of 1-methoxy-2-propanol, 0.28 g of 4-hydroxy-TEMPO, 46.0 g of glycidyl methacrylate, and 3.4 g of tetrabutylammonium bromide were added and stirred evenly, and then heated at 90 °C.

[1294] After 18 hours, the reaction solution was cooled to room temperature (25 °C), and then 0.06 g of 4-methoxyphenol and 114.5 g of 1-methoxy-2-propanol were added for dilution.

[1295] In the binder polymer (3) thus obtained, the solid content concentration was 23% by mass, and the polystyrene-converted weight-average molecular weight measured by GPC was 15,000.

[1296] [Chemical Formula 71]

[1297]

[1298] (Formation of Protective Layer G)

[1299] The protective layer coating solution G having the following composition was bar-coated on the image recording layer G and dried at 120 °C for 60 seconds to form a protective layer G with a thickness of 0.15 μm.

[1300] (Coating solution G for protective layer)

[1301] Inorganic layered compound dispersion (1): 1.799 parts

[1302] Hydrophilic polymer (1) (20% aqueous solution of the following compound): 0.264 parts

[1303] 6 mass% aqueous solution of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., CKS50, sulfonic acid-modified, saponification degree of 99 mol% or more, degree of polymerization of 300): 0.012 parts

[1304] 6 mass% aqueous solution of polyvinyl alcohol (PVA-405 manufactured by KURARAY Co., Ltd., saponification degree of 81.5 mol%, degree of polymerization of 500): 0.001 parts

[1305] RAPISOL A-80 (anionic surfactant, manufactured by NOF CORPORATI0N, 80% aqueous solution): 0.145 parts

[1306] Ion-exchanged water: 5.3379 parts

[1307] [Chemical formula 72]

[1308]

[1309] (Preparation of inorganic layered compound dispersion (1))

[1310] To 193.6 parts of ion-exchanged water, 6.4 parts of synthetic mica SOMASIF ME-100 (manufactured by Co-op Chemical Co., Ltd.) was added and dispersed using a homogenizer until the volume average particle diameter (laser scattering method) became 3 μm to prepare an inorganic layered compound dispersion (1). The aspect ratio of the dispersed particles is 100 or more.

[1311] (Formation of protective layer H)

[1312] The protective layer coating solution H having the following composition was bar-coated on the image recording layer H and dried at 120 °C for 60 seconds to form a protective layer H with a thickness of 0.18 μm.

[1313] (Coating solution H for protective layer)

[1314] · Inorganic layered compound dispersion (1): 2.212 parts

[1315] · Aqueous solution (6% by mass) of polyvinyl alcohol (GOHSERAN L-3266, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., sulfonic acid-modified, saponification degree 85 mol%): 1.440 parts

[1316] · Phosphoric acid: 0.020 parts

[1317] · Diammonium phosphate: 0.032 parts

[1318] · Surfactant (PIONIN A-32-B (the following structure), manufactured by Takemoto Oil & Fat Co., Ltd., 40% by mass aqueous solution): 0.014 parts

[1319] · Surfactant (Surfynol 465 (the following), manufactured by Nissin Chemical Industry Co., Ltd.): 0.006 parts

[1320] · Pure water: 3.955 parts

[1321] (Preparation of inorganic layered compound dispersion (1))

[1322] To 193.6 parts of ion-exchanged water, 6.4 parts of synthetic mica SOMASIF ME-100 (manufactured by Co-op Chemical Co., Ltd.) was added and dispersed using a homogenizer until the volume average particle diameter (laser scattering method) became 3 μm to prepare inorganic layered compound dispersion (1). The aspect ratio of the dispersed particles was 100 or more.

[1323] [Chemical formula 73]

[1324]

[1325] [Chemical formula 74]

[1326]

[1327] [Chemical formula 75]

[1328]

[1329] (Evaluation)

[1330] 1. Evaluation of planarity

[1331] The original lithographic printing plate produced was processed into 40 cm × 62 cm. The surface of the outermost layer of the obtained sample was visually observed under white lamp irradiation of 750 - 1500 Lux, and the planarity was evaluated according to the following criteria. The results are shown in Tables 3 - 4.

[1332] -Standard-

[1333] A: No unevenness is visually recognized on the entire surface.

[1334] B: Slight local unevenness is visually recognized.

[1335] C: Slight local unevenness is visually recognized in a wider area than B.

[1336] D: Slight unevenness is visually recognized on the entire surface.

[1337] E: Obvious unevenness is visually recognized on the entire surface.

[1338] 2. Evaluation of on-machine developability

[1339] Using Magnus800 Quantum manufactured by Kodak, which is equipped with an infrared semiconductor laser, the original lithographic printing plate was exposed under the conditions of an output power of 27 W, an outer drum rotation speed of 450 rpm, and a resolution of 2,400 dpi (dots per inch, 1 inch is 2.54 cm) (equivalent to an irradiation energy of 110 mJ / cm 2 ). The exposure image was made to include a solid image and an amplitude modulation screen 50% dot pattern.

[1340] The obtained exposed original plate is installed on the cylinder of the printing press SX-74 manufactured by Heidelberger Druckmaschinen AG in the size of a chrysanthemum plate without being developed. A dampening solution circulation tank with a capacity of 100 L, which incorporates a non-woven fabric filter and a temperature control device, is connected to this printing press. 80 L of a dampening solution S-Z1 (manufactured by Fujifilm Corporation) with a concentration of 2.0% is filled into the circulation device, and T&K UV OFS K-HS ink GE-M (manufactured by T&K TOKA Corporation) is used as the printing ink. After supplying the dampening solution and the ink by the standard automatic printing start method, printing was performed on TOKUBISHI art paper (continuous quantity: 76.5 kg, manufactured by Mitsubishi Paper Mills Limited) at a printing speed of 10,000 sheets per hour for 200 sheets. In the above on-press development, the number of sheets of printing paper required until the state where the ink does not transfer to the non-image area was obtained (hereinafter, also referred to as the on-press development number of sheets). It can be said that the fewer the on-press development number of sheets, the better the on-press developability. In the above on-press development, the number of sheets of printing paper required until the state where the ink does not transfer to the non-image area was obtained as the on-press developability. The fewer the above-mentioned number of sheets, the better the on-press developability can be said. The results are shown in Table 6.

[1341] [Table 6]

[1342]

[1343] From the results described in Tables 3 to 6, it can be seen that the lithographic printing plate original according to the examples is excellent in flatness compared with the lithographic printing plate original according to the comparative examples.

[1344] Furthermore, from the results described in Tables 3 to 4, it can also be seen that the lithographic printing plate originals according to Examples 1 to 19 and 25 to 26 are excellent in on-press developability compared with the lithographic printing plate originals according to Comparative Examples 1 to 3 and 9.

[1345] (Evaluation of the acid-developed image recording layer)

[1346] In the evaluation of the on-press developability of the lithographic printing plate originals according to Examples 1 to 19 and 25 to 26, exposure and development with various parameter settings such as SD value, Slope value, and Curve value were performed under the following conditions. Except for this, the lithographic printing plate originals were produced and evaluated in the same manner as in Examples 1 to 19 and 25 to 26.

[1347] Specifically, the lithographic printing plate original is exposed into a pre-set image shape, developed by gently wiping with a sponge (manufactured by 3M Company) impregnated with PSFinishingGum FN-6 (manufactured by Fujifilm Corporation), then, the plate surface is cleaned with a water-containing cloth, and then, an acidic solution prepared by mixing 10 g of citric acid (manufactured by FUJIFILM Wako Pure Chemical Corporation) and 90 cc of kitchen alcohol disinfectant (manufactured by FUMAKILLA LIMITED) is impregnated into a sponge (manufactured by 3M Company) and evenly spread on the plate surface to cause the image portion to develop color.

[1348] The evaluation results of the on-machine developability in Examples 1 to 19 and 25 to 26 are the same as the corresponding evaluation results of the on-machine developability in Examples 1 to 19 and 25 to 26. That is, it was confirmed that the lithographic printing plate original of the example has good on-machine developability even when the image portion is caused to develop color for the purpose of improving visual recognition.

[1349] 〔Symbol Explanation〕

[1350] 12a, 12b - aluminum support, 18 - aluminum plate, 20a, 20b - anodic oxide film, 22a, 22b - micropores, 24 - large-diameter hole portion, 26 - small-diameter hole portion, D - depth of the large-diameter hole portion, 1 - aluminum plate, 2 and 4 - drum-shaped brushes, 3 - polishing slurry, 5, 6, 7 and 8 - support rollers, 50 - main electrolytic cell, 51 - AC power supply, 52 - Radial drum roller, 53a, 53b - main poles, 54 - electrolyte supply port, 55 - electrolyte, 56 - auxiliary anode, 57 - electrolyte passage, 58 - auxiliary anode, 60 - auxiliary anode tank, 610 - anodizing treatment device, 612 - power supply tank, 614 - electrolytic treatment tank, 616 - aluminum plate, 618 - electrolyte, 620 - power supply electrode, 622, 628 - rollers, 624 - clamping roller, 630 - electrolytic electrode, 632 - cell wall, 634 - DC power supply, W - aluminum plate, S - liquid supply direction, Ex - electrolyte discharge direction, ta - anodic reaction time, tc - cathodic reaction time, tp - time for the current to reach the peak value, Ia - current at the peak value on the anodic cycle side, Ic - current at the peak value on the cathodic cycle side, AA - current of the anodic reaction of the aluminum plate, CA - current of the cathodic reaction of the aluminum plate.

[1351] The disclosures of Japanese Patent Application 2022 - 192211 filed on November 30, 2022 and Japanese Patent Application 2023 - 113277 filed on July 10, 2023 are incorporated herein by reference.

[1352] All documents, patent applications, and technical standards cited in the present invention are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard cited specifically and separately were incorporated by reference.

Claims

1. An original lithographic printing plate having a support and an image recording layer on the support, wherein the image recording layer contains a (meth)acrylic polymer A having a substituent containing two or more silicon atoms in a side chain.

2. An original lithographic printing plate having a support and an image recording layer on the support, wherein the image recording layer contains a polymer B having a structural unit represented by the following formula (I). In formula (I), R 11 and R 12 each independently represents a hydrogen atom or an alkyl group, R 13 represents a hydrogen atom or a monovalent substituent, L 11 and L 12 each independently represents a single bond or a divalent linking group, and Rh represents a substituent containing two or more silicon atoms.

3. The original lithographic printing plate according to claim 1 or 2, which is an on-press developable original lithographic printing plate.

4. The original lithographic printing plate according to claim 3, wherein, the image recording layer further contains resin particles.

5. The original lithographic printing plate according to claim 3, wherein, the image recording layer further contains a color former.

6. The original lithographic printing plate according to claim 1, wherein, the (meth)acrylic polymer A is a copolymer containing a structural unit having a substituent containing two or more silicon atoms in a side chain and a structural unit having a hydrophilic group in a side chain.

7. The original lithographic printing plate according to claim 1, wherein, the (meth)acrylic polymer A is a copolymer containing a structural unit having a substituent containing two or more silicon atoms in a side chain and a structural unit having a polyalkyleneoxy group in a side chain.

8. The original lithographic printing plate according to claim 2, wherein, Rh in the formula (I) is a group containing two or more structures represented by the following formula (Ia). In formula (Ia), * represents the bonding position, and R 11 , R 12 , and R 13 each independently represents an alkyl group, an alkenyl group, an aryl group, or an alkylene aryl group.

9. The original lithographic printing plate according to claim 2, wherein, the polymer B is a copolymer further having a structural unit having a hydrophilic group in a side chain.

10. The original lithographic printing plate according to claim 9, wherein, the structural unit having a hydrophilic group in a side chain is a structural unit represented by the following formula (a4). In formula (a4), R 7 and R 8 each independently represents a hydrogen atom or an alkyl group, R 9 represents a hydrogen atom or a monovalent substituent, L 2 represents -C(=O)-O- or -C(=O)-NH-, L 3 represents a single bond or a divalent linking group, and X represents a hydrophilic group.

11. The original lithographic printing plate according to claim 10, wherein, In the formula (a4), L 2 represents -C(=O)-NH-.

12. The original lithographic printing plate according to claim 10, wherein, in the formula (a4), the hydrophilic group represented by X is a hydroxyl group, a polyalkyleneoxy group, or a group formed by combining two or more of them.

13. The original lithographic printing plate according to claim 2, wherein, the polymer B is a copolymer further having a structural unit having a polyalkyleneoxy group in a side chain.

14. The original lithographic printing plate according to claim 2 or 7, wherein, L in the formula (I) 11 is an ester bond.

15. A method for producing a lithographic printing plate, comprising: a step of exposing the original lithographic printing plate according to claim 3 into an image; and a step of supplying at least one selected from printing ink and dampening solution on a printing press to remove the image recording layer in a non-image area.

16. A lithographic printing method, comprising: a step of exposing the original lithographic printing plate according to claim 3 into an image; a step of supplying at least one selected from printing ink and dampening solution on a printing press to remove the image recording layer in a non-image area to produce a lithographic printing plate; and a step of performing printing using the obtained lithographic printing plate.

Images