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

Abstract

The present invention provides a lithographic printing plate having a support and an image recording layer formed on the support. The image recording layer contains an infrared absorber, a polymerization initiator and a polymer A, wherein the weight-average molecular weight of polymer A is greater than 15,000 and less than 150,000, and the olefin unsaturated bond value of polymer A is 3.0 mmol / g or more.

Description

[0001] This application is a divisional application of application number 202080067972.6, entitled "Optolith Printing Original, Method for Making Optolith Printing Plate and Optolith Printing Method". The parent application was filed on August 28, 2020, and the priority date is September 30, 2019. Technical Field

[0002] This invention relates to a lithographic printing plate original, a method for making a lithographic printing plate, and a lithographic printing method. Background Technology

[0003] Typically, a lithographic printing plate consists of an oleophilic image area that receives ink during the printing process and a hydrophilic non-image area that receives dampening solution. Lithographic printing is a method that utilizes the repulsive properties of water and oil-based inks. The oleophilic image area of ​​the lithographic printing plate serves as the ink receiving area, while the hydrophilic non-image area serves as the dampening solution receiving area (non-ink receiving area). This difference in ink adhesion is created on the surface of the lithographic printing plate, causing the ink to adhere only to the image area. The ink is then transferred to the substrate, such as paper, for printing.

[0004] To produce this lithographic printing plate, conventionally, lithographic printing master plates (PS plates) with an oleophilic photosensitive resin layer (image recording layer) on a hydrophilic support have been widely used. Typically, a lithographic printing plate is obtained by exposing the lithographic printing master plate to an original image such as high-contrast film, leaving a portion of the image recording layer remaining as the image area. This remaining portion is then removed by dissolving it with an alkaline developer or organic solvent, thus exposing the surface of the hydrophilic support and forming a non-image area.

[0005] Furthermore, due to increasing concern for the Earth's environment, environmental problems related to waste liquids accompanying wet processing such as developing processes have become apparent.

[0006] To address the aforementioned environmental issues, the focus shifted to simplifying or eliminating the need for pretreatment in development or plate making. As one of the simplest manufacturing methods, a method called "in-machine development" was developed. This involves exposing the original lithographic printing plate and then directly mounting it onto the printing press without the usual development process, while removing unnecessary portions of the image recording layer at the initial stage of the normal printing process.

[0007] As a previous lithographic printing original, for example, the lithographic printing original described in Patent Document 1 can be cited.

[0008] Patent Document 1 describes a lithographic printing plate original, wherein a water-soluble or water-dispersible negative image recording layer is provided on a hydrophilic aluminum support, and the arithmetic mean height Sa of the outermost surface of the side having the image recording layer is 0.3 μm or more and 20 μm or less.

[0009] Furthermore, as a conventional plate preparation agent for lithographic printing plates, for example, the lithographic printing plate original described in Patent Document 2 can be cited.

[0010] Patent document 2 describes a plate treatment agent for lithographic printing plates, characterized in that it contains a star-shaped polymer having at least one support adsorption group and at least one hydrophilic group.

[0011] Patent Document 1: International Publication No. 2018 / 181993

[0012] Patent Document 2: Japanese Patent Application Publication No. 2012-200959 Summary of the Invention

[0013] The technical problem to be solved by the invention

[0014] The problem to be solved by the embodiments of the present invention is to provide a lithographic printing plate original that has excellent printing durability even when using UV ink.

[0015] Another embodiment of the present invention aims to solve the problem of providing a method for producing a lithographic printing plate or a lithographic printing method using the above-described lithographic printing plate original.

[0016] means for solving technical problems

[0017] The following methods are among the ways to solve the above problems.

[0018] <1> A lithographic printing plate original having a support and an image recording layer formed on the support, the image recording layer containing an infrared absorber, a polymerization initiator and a polymer A, wherein the weight-average molecular weight of the polymer A is greater than 15,000 and less than 150,000, and the olefin unsaturated bond value of the polymer A is 3.0 mmol / g or more.

[0019] <2> Based on the original lithographic printing plate described in <1>, wherein,

[0020] The polymer A described above comprises a resin represented by the following formula (I).

[0021] A P -(B P ) nP Formula (I)

[0022] In formula (I), A P B represents an organic group with an nP valence that has hydrogen bonding. P This indicates a group having two or more polymerizable groups, where nP represents an integer greater than 2.

[0023] <3> Based on the original lithographic printing plate described in <1> or <2>, wherein,

[0024] The polymer A described above has at least one structure selected from the group consisting of adduct structures, biuret structures and isocyanurate structures.

[0025] <4> The original lithographic printing plate according to any one of <1> to <3>, wherein,

[0026] The polymer A described above has a structure represented by any one of the following formulas (A-1) to (A-3).

[0027] [Chemical Formula 1]

[0028]

[0029] In equation (A-1), R A1 This indicates an alkyl group with 1 to 8 hydrogen atoms or carbon atoms, and the wavy line indicates the bonding position with other structures.

[0030] <5> According to the original lithographic printing plate described in <2>, among which,

[0031] The above B P The polymerizable group in it includes (meth)acryloyloxy.

[0032] <6> Based on the original lithographic printing plate described in <2> or <5>, wherein,

[0033] The above B P It is a group having three or more (meth)acryloyloxy groups.

[0034] <7> The original lithographic printing plate according to any one of <1> to <6>, wherein,

[0035] The image recording layer described above contains two or more polymers A.

[0036] <8> The original lithographic printing plate according to any one of <1> to <7>, wherein,

[0037] The aforementioned image recording layer also contains a polymeric compound B with a weight-average molecular weight of 1,000 or more and 15,000 or less.

[0038] <9> The original lithographic printing plate according to any one of <1> to <8>, wherein,

[0039] The aforementioned image recording layer also contains a polymeric compound C with a molecular weight of less than 1,000.

[0040] <10> The original lithographic printing plate according to any one of <1> to <9>, wherein,

[0041] The image recording layer mentioned above is the outermost layer.

[0042] <11> The original lithographic printing plate according to any one of <1> to <10>, wherein,

[0043] The aforementioned image recording layer also contains polymer particles.

[0044] <12> Based on the original lithographic printing plate described in <11>, wherein,

[0045] The polymer particles described above have hydrophilic groups.

[0046] <13> Based on the original lithographic printing plate described in <12>, wherein,

[0047] The hydrophilic group mentioned above is a group represented by the following formula Z.

[0048] *-QWY formula Z

[0049] In formula Z, Q represents a divalent linking group, W represents a divalent group with a hydrophilic structure or a divalent group with a hydrophobic structure, Y represents a monovalent group with a hydrophilic structure or a monovalent group with a hydrophobic structure, either W or Y has a hydrophilic structure, and * represents the bonding site with other structures.

[0050] <14> Based on the original lithographic printing plate described in <12> or <13>, wherein,

[0051] The aforementioned hydrophilic structure includes a polyepoxide structure.

[0052] <15> The original lithographic printing plate according to any one of <11> to <14>, wherein,

[0053] The polymer particles described above contain building blocks formed from aromatic vinyl compounds.

[0054] <16> The original lithographic printing plate according to any one of <1> to <15>, wherein,

[0055] The aforementioned polymerization initiators include electron-donating polymerization initiators.

[0056] <17> Based on the original lithographic printing plate described in <16>, wherein,

[0057] The HOMO value of the above-mentioned infrared absorber is less than 0.70 eV.

[0058] <18> The original lithographic printing plate according to any one of <1> to <17>, wherein,

[0059] The aforementioned image recording layer also contains a color developer.

[0060] <19> The original lithographic printing plate according to any one of <1> to <18>, wherein,

[0061] The aforementioned support is an aluminum support, comprising an aluminum plate and an anodized aluminum film disposed on the aluminum plate. The anodized film is located closer to the image recording layer side than the aluminum plate. The anodized film has micropores extending along the depth direction from the surface of the image recording layer side. The average diameter of the micropores on the surface of the anodized film is greater than 10 nm and less than 100 nm. The L-shaped surface of the anodized film on the image recording layer side... * a * b * Lightness (L) in the color system * The value is 70-100.

[0062] <20> Based on the original lithographic printing plate described in <19>, wherein,

[0063] The aforementioned micropores are 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 depth of 10 nm to 1,000 nm. The small-diameter pore portion is connected to the bottom of the large-diameter pore portion and extends from the connection position to a depth of 20 nm to 2,000 nm. The average diameter of the large-diameter pore portion on the surface of the anodic oxide film is 15 nm to 100 nm, and the average diameter of the small-diameter pore portion at the connection position is less than 13 nm.

[0064] <21> The original lithographic printing plate according to any one of <1> to <20>, wherein,

[0065] The aforementioned image recording layer has a protective layer containing a color-changing compound.

[0066] <22> Based on the original lithographic printing plate described in <21>, wherein,

[0067] At 110mJ / cm 2 When the energy density is used for exposure to infrared light with a wavelength of 830 nm, the brightness change ΔL before and after the exposure is greater than 2.0.

[0068] <23> Based on the original lithographic printing plate described in <21> or <22>, wherein,

[0069] The aforementioned color-changing compounds include those that develop color upon exposure to infrared light.

[0070] <24> The original lithographic printing plate according to any one of <21> to <23>, wherein,

[0071] The aforementioned color-changing compounds include decomposable compounds that decompose upon exposure to infrared light.

[0072] <25> Based on the original lithographic printing plate described in <24>, wherein,

[0073] The aforementioned color-changing compounds include decomposable compounds that decompose through thermal, electron migration, or both caused by infrared exposure.

[0074] <26> The original lithographic printing plate according to any one of <21> to <25>, wherein,

[0075] The aforementioned color-changing compound is anthocyanin.

[0076] <27> The original lithographic printing plate according to any one of <21> to <26>, wherein,

[0077] The aforementioned color-changing compounds are compounds represented by the following formula 1-1.

[0078] [Chemical Formula 2]

[0079]

[0080] In Equation 1-1, R 1 R represents a group represented by any one of the following formulas 2 to 4. 11 ~R 18 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -SR c or -NR d R e R a ~R e Each of the following groups independently represents a hydrocarbon group: A1, A2, and multiple R groups. 11 ~R 18 They can be linked to form single or multiple rings, where A1 and A2 independently represent oxygen, sulfur, or nitrogen atoms, respectively, and n 11 and n 12 Each of the integers from 0 to 5 can be represented independently, where n 11 and n 12 The total is 2 or more, n 13 and n 14 Each can be independently represented as 0 or 1, and L represents an oxygen atom, a sulfur atom, or -NR.10 -, R 10 It represents a hydrogen atom, alkyl group, or aryl group; Za represents a counterion that neutralizes the charge.

[0081] [Chemical Formula 3]

[0082]

[0083] In equations 2 to 4, R 20 R 30 R 41 and R 42 Each alkyl or aryl group is represented independently, Zb represents a counterion that neutralizes the charge, and the wavy line represents the bonding site with the group represented by L in Formula 1-1 above.

[0084] <28> The original lithographic printing plate according to any one of <21> to <27>, wherein,

[0085] The aforementioned color-changing compounds are those represented by the following formulas 1-2.

[0086] [Chemical Formula 4]

[0087]

[0088] In Equation 1-2, R 1 R represents any one of the groups represented by formulas 2 to 4 above. 19 ~R 22 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -CN, -SR c or -NR d R e R 23 and R 24 Each can be used independently to represent a hydrogen atom or -R. a R a ~R e Each independently represents a hydrocarbon group, R 19 With R 20 R 21 With R 22 Or R 23 With R 24 They can be linked to form single or multiple rings, where L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 R represents a hydrogen atom, alkyl group, or aryl group. d1 ~R d4 W 1 and W 2 Each of these can independently represent an alkyl group that may have substituents, and Za represents a counterion that neutralizes the charge.

[0089] <29> The original lithographic printing plate according to any one of <21> to <28>, wherein,

[0090] The aforementioned color-changing compounds are compounds represented by any one of the following formulas 1-3 to 1-7.

[0091] [Chemical Formula 5]

[0092]

[0093] In equations 1-3 to 1-7, R 1 R represents any one of the groups represented by formulas 2 to 4 above. 19 ~R 22 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -CN, -SR c or -NR d R e R 25 and R 26 Each can be used independently to represent a hydrogen atom, a halogen atom, or -R. a R a ~R e Each independently represents a hydrocarbon group, R 19 With R 20 R 21 With R 22 Or R 25 With R 26 They can be linked to form single or multiple rings, where L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 R represents a hydrogen atom, alkyl group, or aryl group. d1 ~R d4 W 1 and W 2 Each of these can independently represent an alkyl group that may have substituents, and Za represents a counterion that neutralizes the charge.

[0094] <30> Based on the original lithographic printing plate described in <28> or <29>, wherein,

[0095] W in equations 1-2 to 1-7 above 1 and W 2 Each is an alkyl group having a substituent, and is a group having at least -(OCH2CH2)-, sulfonyl, a salt of sulfonyl, carboxyl, or a salt of carboxyl.

[0096] <31> The original lithographic printing plate according to any one of <28> to <30>, wherein,

[0097] In Equations 1-2 to 1-7 above, L represents an oxygen atom.

[0098] <32> The original lithographic printing plate according to any one of <21> to <31>, wherein,

[0099] The content M of the aforementioned color-changing compound in the aforementioned protective layer X The content M of the infrared absorber in the image recording layer described above Y The ratio of M X / M Y It is above 0.2.

[0100] <33> The original lithographic printing plate according to any one of <21> to <32>, wherein,

[0101] The aforementioned protective layer contains a water-soluble polymer.

[0102] <34> Based on the original lithographic printing plate described in <33>, among which,

[0103] The aforementioned water-soluble polymer contains polyvinyl alcohol with a saponification degree of 50% or higher.

[0104] <35> Based on the original lithographic printing plate described in <33> or <34>, wherein,

[0105] The aforementioned water-soluble polymer contains polyvinylpyrrolidone.

[0106] <36> The original lithographic printing plate according to any one of <33> to <35>, wherein,

[0107] The aforementioned protective layer contains a hydrophobic polymer.

[0108] <37> Based on the original lithographic printing plate described in <36>, among which,

[0109] The aforementioned hydrophobic polymers are hydrophobic polymer particles.

[0110] <38> Based on the original lithographic printing plate described in <36> or <37>, wherein,

[0111] The aforementioned hydrophobic polymers include polyvinylidene chloride resin.

[0112] <39> The original lithographic printing plate according to any one of <36> to <38>, wherein,

[0113] The aforementioned hydrophobic polymers include styrene-acrylic copolymers.

[0114] <40> The original lithographic printing plate according to any one of <21> to <39>, wherein,

[0115] The aforementioned protective layer contains a sensitizer.

[0116] <41> The original lithographic printing plate according to any one of <21> to <40>, wherein,

[0117] The amount of the above protective layer is 0.1 g / m 2 ~2.0g / m 2 .

[0118] <42> A method for manufacturing a lithographic printing plate, comprising: a step of exposing a lithographic printing plate original as described in any one of <1> to <41> in an image-like manner; and a step of supplying an image recording layer selected from the group consisting of printing ink and dampening solution to a printing press to remove non-image portions.

[0119] <43> A lithographic printing method, comprising: a step of exposing a lithographic printing plate original as described in any one of <1> to <41> in an image-like manner; a step of producing a lithographic printing plate by supplying at least one of the group consisting of printing ink and dampening solution to remove a non-image portion of an image recording layer on a printing press; and a step of printing using the obtained lithographic printing plate.

[0120] Invention Effects

[0121] According to embodiments of the present invention, it is possible to provide a lithographic printing plate original that exhibits excellent printing durability even when using UV inks.

[0122] Furthermore, according to another embodiment of the present invention, a method for producing a lithographic printing plate or a lithographic printing method using the above-described lithographic printing plate original can be provided. Attached Figure Description

[0123] Figure 1 This is a schematic cross-sectional view of one embodiment of the aluminum support.

[0124] Figure 2 This is a schematic cross-sectional view of another embodiment of the aluminum support.

[0125] Figure 3 This is a graph illustrating an example of an alternating current waveform used in the electrochemical roughening process during the manufacturing of an aluminum support.

[0126] Figure 4 This is a side view illustrating an example of a radial unit in an electrochemical roughening process using alternating current in the manufacturing method of an aluminum support. Detailed Implementation

[0127] The present invention will now 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 this embodiment.

[0128] In addition, in this specification, the "~" sign indicating a numerical range is used to imply that the values ​​before and after it are included as lower and upper limits.

[0129] In the numerical ranges described in stages in this invention, the upper or lower limit value described in one numerical range can be replaced with the upper or lower limit value of other numerical ranges described in stages. Furthermore, within the numerical ranges described in this invention, the upper or lower limit value of that numerical range can be replaced with the values ​​shown in the embodiments.

[0130] Furthermore, in this specification, the designations of groups (atomic groups) that do not indicate substitution or unsubstituted include not only groups without substituents but also groups with substituents. For example, "alkyl" includes not only alkyl groups without substituents (unsubstituted alkyl) but also alkyl groups with substituents (substituted alkyl).

[0131] In this specification, "(meth)acrylic acid" is used as a term that includes both acrylic acid and methacrylic acid, and "(meth)acryloyl" is used as a term that includes both acryloyl and methacryloyl.

[0132] Furthermore, the term "process" in this specification includes not only independent processes, but also processes that cannot be clearly distinguished from other processes, as long as the intended purpose of the process can be achieved. Also, in this invention, "mass%" and "weight%" are defined the same, and "parts by mass" and "parts by weight" are defined the same.

[0133] Furthermore, in this invention, a combination of two or more preferred methods is a more preferred method.

[0134] Furthermore, unless otherwise specified, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) in this invention are molecular weights converted from polystyrene and measured using a gel permeation chromatography (GPC) analysis apparatus with columns of TSKgel GMHxL, TSKgel G4000HxL, and TSKgel G2000HxL (all trade names manufactured by TOSOH CORPORATION) and detected by solvent THF (tetrahydrofuran) and differential refractometer as standard substances.

[0135] In this specification, the term "lithographic printing plate original" includes not only lithographic printing plate originals but also discarded originals. Furthermore, the term "lithographic printing plate" includes not only lithographic printing plates made from lithographic printing plate originals through exposure, development, and other operations as needed, but also discarded plates. In the case of discarded originals, exposure and development operations are not necessarily required. Additionally, a discarded plate refers to a lithographic printing plate original used to mount on an unused printing cylinder, for example, in color newspaper printing where a portion of the page is printed in single or two colors.

[0136] The present invention will now be described in detail.

[0137] (Original offset printing version)

[0138] The lithographic printing plate of the present invention has a support and an image recording layer formed on the support. The image recording layer contains an infrared absorber, a polymerization initiator and a polymer A. The weight-average molecular weight of the polymer A is greater than 15,000 and less than 150,000, and the olefin unsaturated bond value of the polymer A is 3.0 mmol / g or more.

[0139] Furthermore, the lithographic printing plate master involved in this invention is a negative lithographic printing plate master, and can preferably be used as an on-machine developing type lithographic printing plate master.

[0140] Through in-depth research, the inventors discovered that by adopting the above-described structure, it is possible to provide a lithographic printing plate original that exhibits excellent printing durability even when using UV ink.

[0141] While the detailed mechanism by which the above effects are achieved is unclear, the following speculations are made.

[0142] It is inferred that by including polymer A with a specific range of weight-average molecular weight and an olefinic unsaturation bond value of 3 mmol / g or higher in the image recording layer, the polymerization efficiency of the image section is improved, the crosslinking density is increased, and the printing durability (especially UV printing durability) is excellent.

[0143] Furthermore, the lithographic printing plate original involved in this invention contains a polymer A with a specific range of weight-average molecular weight and an olefin unsaturated bond value of 3.0 mmol / g or more in the image recording layer. In the cured image area, the reduction of the image area caused by ink penetration, ink-based dissolution, and printing abrasion can be suppressed. Even when using UV ink, the plate abrasion suppression performance is excellent.

[0144] In addition, "plate wear" refers to the phenomenon where the image recording layer in a lithographic printing plate thins and partially becomes unusable for ink. The number of prints required to cause "plate wear" in a lithographic printing plate is used as an indicator of "not easily subject to plate wear".

[0145] <Image Recording Layer>

[0146] The image recording layer in the lithographic printing plate original involved in this invention contains an infrared absorber, a polymerization initiator, and a polymer A, wherein the weight-average molecular weight of polymer A is greater than 15,000 and less than 150,000, and the olefin unsaturated bond value of polymer A is greater than 3.0 mmol / g.

[0147] The image recording layer in this invention is a negative image recording layer, preferably a water-soluble or water-dispersible negative image recording layer.

[0148] Furthermore, the image recording layer in this invention is preferably an on-machine developing type image recording layer.

[0149] Furthermore, from the viewpoint of UV printing durability and UV plate wear inhibition, the image recording layer in this invention is preferably the outermost layer.

[0150] The following is a detailed description of the components contained in the image recording layer.

[0151] -Polymer A-

[0152] The image recording layer contains polymer A, wherein the weight-average molecular weight of polymer A is greater than 15,000 and less than 150,000, and the olefin unsaturated bond value of polymer A is greater than 3.0 mmol / g.

[0153] Previously, polymers that meet the above-mentioned weight-average molecular weight range and have a very large number of olefin unsaturated bonds per unit mass with an olefin unsaturated bond value of 3.0 mmol / g or higher were unknown.

[0154] The weight-average molecular weight (Mw) of the polymer A is greater than 15,000 and less than 150,000. From the viewpoint of UV printing durability and UV plate wear inhibition, it is preferably more than 20,000 and less than 150,000, more preferably more than 40,000 and less than 150,000, and especially preferably more than 70,000 and less than 150,000.

[0155] Furthermore, from the viewpoint of reproducibility, the weight-average molecular weight of the polymer A is preferably 130,000 or less.

[0156] The weight-average molecular weight Mw in polymer A or polymeric compound B (described later) is determined using the following measuring equipment and methods.

[0157] GPC measuring equipment: TOSOH HLC-8320GPC (manufactured by Tosoh Corporation)

[0158] GPC mobile phase: Tetrahydrofuran (THF)

[0159] Inspector: Differential Refractive Index Detector (RI)

[0160] Flow rate: 0.35 mL / min

[0161] Column: Connect TSKgel SuperHZM-M, TSKgel SuperHZ4000, TSKgel SuperHZ3000 and TSKgel SuperHZ2000 (all manufactured by Tosoh Corporation) for use.

[0162] Column temperature: 40℃

[0163] Standard sample used for molecular weight calibration curve: polystyrene (PS)

[0164] The olefinic unsaturated bond value (also referred to as "C=C value") of the polymer A is 3.0 mmol / g or more. From the viewpoint of UV printing durability and UV plate wear inhibition, it is preferably 4.0 mmol / g or more, more preferably 5.0 mmol / g or more, more preferably 4.5 mmol / g to 12.0 mmol / g, even more preferably 5.0 mmol / g to 10.0 mmol / g, and particularly preferably 5.5 mmol / g to 8.5 mmol / g.

[0165] The olefinic unsaturated bond values ​​in polymer A or polymeric compound B (described later) can be determined by the following method.

[0166] First, for a given sample amount (e.g., 0.2 g) of the compound, the structure of the compound is determined, for example, using pyrolysis GC / MS, FT-IR, NMR, TOF-SIMS, etc., and the total amount (mmol) of olefinic unsaturated groups is calculated. The number of olefinic unsaturated bonds in the compound is calculated by dividing the calculated total amount (mmol) of olefinic unsaturated groups by the sample amount (g) of the compound.

[0167] The structure of polymer A is not particularly limited, and can be, for example, a graft polymer, a star polymer, a hyperbranched polymer, a dendritic polymer, etc. However, as described later, polymers obtained by sealing the terminal isocyanate groups of polymers (including adducts) of polyfunctional isocyanate compounds with compounds having olefinic unsaturated groups are preferred.

[0168] From the viewpoint of UV printing durability and UV plate wear inhibition, the polymer A is preferably provided with hydrogen-bonded groups, and more preferably with three or more hydrogen-bonded groups.

[0169] Regarding the aforementioned hydrogen-bonding groups, any group capable of hydrogen bonding is acceptable; it can be a hydrogen bond donor group, a hydrogen bond acceptor group, or both.

[0170] Examples of hydrogen-bonding groups include hydroxyl, carboxyl, amino, carbonyl, sulfonyl, carbamate, urea, imide, amide, and sulfonamide groups.

[0171] From the viewpoint of UV printing durability and UV plate wear inhibition, the hydrogen-bonding group is preferably selected from at least one group selected from the group consisting of urethane, urea, imide, amide and sulfonamide groups. More preferably, it is selected from at least one group selected from the group consisting of urethane, urea, imide and amide groups. Even more preferably, it is selected from at least one group selected from the group consisting of urethane, urea and imide groups. Particularly preferred is at least one group selected from the group consisting of urethane and urea groups.

[0172] Furthermore, from the viewpoint of UV printing durability and UV plate wear inhibition, the polymer A is preferably provided with polymerizable groups.

[0173] The polymerizable group described above can be, for example, a cationic polymerizable group or a free radical polymerizable group, but from the viewpoint of reactivity, a free radical polymerizable group is preferred.

[0174] There are no particular limitations on the polymerizable groups mentioned above, but from the viewpoints of reactivity, UV printing durability, and UV plate wear inhibition, olefinic unsaturated groups are preferred, more preferably at least one group selected from the group consisting of vinylphenyl (styrene), vinyl ester, vinyl ether, allyl, (meth)acryloyloxy, and (meth)acrylamide, and even more preferably at least one group selected from the group consisting of vinylphenyl (styrene), (meth)acryloyloxy, and (meth)acrylamide, especially (meth)acryloyloxy.

[0175] Furthermore, from the viewpoint of UV printing durability and UV plate wear inhibition, the polymer A, as the polymeric group, preferably has a structure represented by the following formula (Po-1) or formula (Po-2), and more preferably has a structure represented by the following formula (Po-1).

[0176] [Chemical Formula 6]

[0177]

[0178] In equations (Po-1) and (Po-2), R P Each group represents an acryloyl group or a methacrylic acid group independently, and the wavy line indicates the bonding position with other structures.

[0179] In formula (Po-1) or formula (Po-2), R is preferred. P They are all the same group.

[0180] Furthermore, in formula (Po-1) or formula (Po-2), R P Acryloyl group is preferred.

[0181] Furthermore, from the viewpoint of UV printing durability and UV plate wear inhibition, the polymer A is preferably a (meth)acrylate compound having a urethane group, i.e., urethane (meth)acrylate.

[0182] Furthermore, from the viewpoint of UV printing durability and UV plate wear inhibition, the polymer A is preferably a structure formed by polymerizing a polyfunctional isocyanate compound, and more preferably a structure formed by polymerizing a difunctional isocyanate compound.

[0183] Furthermore, from the viewpoint of UV printing durability and UV plate wear inhibition, the aforementioned polymer A is preferably a polymer obtained by reacting a polyfunctional olefinic unsaturated compound having a hydroxyl group (also referred to as "hydroxyl group") at its terminal with a polymer obtained by polymerizing a polyfunctional isocyanate compound (including adducts of polyfunctional alcohol compounds such as trimethylolpropane adducts). More preferably, it is a polymer obtained by reacting a hydroxyl-containing polyfunctional olefinic unsaturated compound with a polymer obtained by polymerizing a difunctional isocyanate compound (including adducts of polyfunctional alcohol compounds). Particularly preferred is a polymer obtained by reacting a hydroxyl-containing polyfunctional olefinic unsaturated compound with a polymer obtained by polymerizing hexamethylene diisocyanate (including adducts of polyfunctional alcohol compounds).

[0184] There are no particular restrictions on the polyfunctional isocyanate compounds mentioned above; any known polyfunctional isocyanate compound can be used, whether it be an aliphatic or aromatic polyfunctional isocyanate compound.

[0185] Specifically, examples of the aforementioned polyfunctional isocyanate compounds include, for instance, 1,3-bis(isocyanate methyl)cyclohexane, isophorone diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 9H-fluorene-2,7-diisocyanate, 9H-fluorene-9-one-2,7-diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, 1,3-bis(isocyanate methyl)cyclohexane, 2,2-bis(4-isocyanate phenyl)hexafluoropropane, 1,5-naphthalene diisocyanate, and dimers and trimers (isocyanurate bonds) of these polyisocyanates. Furthermore, a biuret obtained by reacting the aforementioned polyisocyanate compound with a known amine compound can be used.

[0186] Furthermore, the aforementioned polyfunctional olefinic unsaturated compounds having hydroxyl groups are preferably olefinic unsaturated compounds having 3 or more functions with hydroxyl groups, and more preferably olefinic unsaturated compounds having 5 or more functions with hydroxyl groups.

[0187] Furthermore, the aforementioned polyfunctional olefinic unsaturated compounds having hydroxyl groups are preferably polyfunctional (meth)acrylate compounds having hydroxyl groups.

[0188] From the viewpoint of UV printing durability and UV plate wear inhibition, the polymer A preferably has at least one structure selected from the group consisting of adduct structure, biuret structure and isocyanurate structure, more preferably has at least one structure selected from the group consisting of trimethylolpropane adduct structure, biuret structure and isocyanurate structure, and especially preferably has a trimethylolpropane adduct structure.

[0189] Furthermore, from the viewpoint of UV printing durability and UV plate wear inhibition, the polymer A preferably has a structure represented by any one of the following formulas (A-1) to (A-3), and more preferably has a structure represented by the following formula (A-1).

[0190] [Chemical Formula 7]

[0191]

[0192] In equation (A-1), R A1 This indicates an alkyl group with 1 to 8 hydrogen atoms or carbon atoms, and the wavy line indicates the bonding position with other structures.

[0193] From the perspective of UV printing durability and UV plate wear inhibition, R in formula (A-1) A1Preferably, it is an alkyl group having 1 to 4 hydrogen atoms or carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, further preferably methyl or ethyl, and especially preferably ethyl.

[0194] The polymer A described above preferably comprises a resin represented by the following formula (I).

[0195] A P -(B P ) nP Formula (I)

[0196] In formula (I), A P B represents an organic group with an nP valence that has hydrogen bonding. P This indicates a group having two or more polymerizable groups, where nP represents an integer greater than 2.

[0197] A in equation (I) P The preferred method for the hydrogen-bonding groups in the above-mentioned hydrogen-bonding groups is the same.

[0198] A in equation (I) P Preferably, it is an organic group that does not have an olefinic unsaturated bond.

[0199] Furthermore, A in equation (I) P Preferably, it is an aliphatic hydrocarbon group with a monovalent to nP valence, an aromatic hydrocarbon group with a monovalent to nP valence, or a group composed of two or more structures selected from the group consisting of urethane bonds, urea bonds, biuret bonds, and urethane bonds. More preferably, it is an aliphatic hydrocarbon group with a monovalent to nP valence, an aromatic hydrocarbon group with a monovalent to nP valence, or a group composed of two or more structures selected from the group consisting of urethane bonds, urea bonds, and biuret bonds.

[0200] Furthermore, from the perspective of UV printing durability and UV plate wear inhibition, A in formula (I) P Preferably, the group is obtained by removing the terminal isocyanate group from a polymer obtained by polymerizing a polyfunctional isocyanate compound (including adducts of polyfunctional alcohol compounds such as trimethylolpropane adducts), more preferably, the group is obtained by removing the terminal isocyanate group from a polymer obtained by polymerizing a difunctional isocyanate compound (including adducts of polyfunctional alcohol compounds), and particularly preferably, the group is obtained by removing the terminal isocyanate group from a polymer obtained by polymerizing hexamethylene diisocyanate (including adducts of polyfunctional alcohol compounds).

[0201] Furthermore, from the perspective of UV printing durability and UV plate wear inhibition, A in formula (I) PThe weight-average molecular weight (Mw) is preferably 10,000 or more and 145,000 or less, more preferably 30,000 or more and 140,000 or less, and especially preferably 60,000 or more and 140,000 or less.

[0202] Furthermore, from the viewpoint of imaging properties, A in equation (I) P The weight-average molecular weight is preferably below 120,000.

[0203] B of equation (I) P The preferred method for the polymeric groups in the above-mentioned polymeric groups is the same.

[0204] From the perspective of UV printing durability and UV plate wear inhibition, B in formula (I) P The polymerizable group preferably includes (meth)acryloyloxy, B of formula (I). P More preferably, it has 3 or more (meth)acryloyloxy groups, even more preferably, it has 5 or more (meth)acryloyloxy groups, and especially preferably, it has 5 or more and 12 or fewer (meth)acryloyloxy groups.

[0205] Furthermore, from the perspective of UV printing durability and UV plate wear inhibition, B in formula (I) P The structure is preferably represented by the above formula (Po-1) or formula (Po-2), and more preferably by the structure represented by the above formula (Po-1).

[0206] Moreover, the preferred formula (I) of B P They are all the same group.

[0207] Furthermore, from the perspective of UV printing durability and UV plate wear inhibition, B in formula (I) P The molecular weight is preferably 300 or more and 1,000 or less, more preferably 400 or more and 800 or less.

[0208] Furthermore, in equation (I), from the viewpoint of UV printing durability and UV plate wear inhibition, A P Weight-average molecular weight / (B P The value of (molecular weight × nP) is preferably 1 or less, more preferably 0.1 or more and 0.9 or less, and especially preferably 0.2 or more and 0.8 or less.

[0209] The polymer A mentioned above can be used alone or in combination with two or more polymers. However, from the viewpoint of UV printing durability and UV plate wear inhibition, the image recording layer preferably contains two or more polymers A.

[0210] Furthermore, in the aforementioned image recording layer, polymer A can be an adhesive polymer or polymer particles in particle shape.

[0211] From the viewpoints of developability, UV printing durability and UV plate wear inhibition, the content of the polymer A in the image recording layer is preferably 5% to 95% by mass, more preferably 10% to 90% by mass, even more preferably 20% to 90% by mass, and especially preferably 50% to 90% by mass, relative to the total mass of the image recording layer.

[0212] -polymer compound B-

[0213] From the viewpoint of UV printing durability and UV plate wear inhibition, the above-mentioned image recording layer preferably further comprises a polymeric compound B with a weight-average molecular weight of 1,000 or more and 15,000 or less.

[0214] The aforementioned polymeric compound B can be, for example, a free radical polymeric compound or a cationic polymeric compound, but is preferably a free radical polymeric compound, and more preferably a compound having an olefinic unsaturated group.

[0215] The structure of the polymeric compound B is not particularly limited, and known oligomers can be used, with urethane (meth)acrylate compounds and star polymers being preferred examples.

[0216] Furthermore, the aforementioned polymeric compound B is preferably a multifunctional polymeric compound.

[0217] Furthermore, the polymeric compound B is preferably a multifunctional polymeric compound containing 3 to 40 functions, more preferably a multifunctional polymeric compound containing 5 to 30 functions, and especially preferably a multifunctional polymeric compound containing 10 to 20 functions.

[0218] The preferred manner in which the polymeric group of the polymeric compound B is present is the same as the preferred manner in which the polymeric group of the polymer A is present.

[0219] From the viewpoint of UV printing durability and UV plate wear inhibition, the polymeric compound B preferably contains a compound with an olefin unsaturated bond value of 1.0 mmol / g or more, more preferably contains a compound with an olefin unsaturated bond value of 2.0 mmol / g to 12.0 mmol / g, and especially preferably contains a compound with an olefin unsaturated bond value of 5.0 mmol / g to 10.0 mmol / g.

[0220] From the viewpoint of UV printing durability and UV plate wear inhibition, the weight-average molecular weight (Mw) of the above-mentioned polymeric compound B is preferably 2,000 or more and 15,000 or less, more preferably 3,000 or more and 15,000 or less, even more preferably 5,000 or more and 15,000 or less, and particularly preferably 10,000 or more and 15,000 or less.

[0221] There is no particular limitation on the above-mentioned urethane (meth)acrylate compounds, but for example, compounds obtained by reacting a polyisocyanate compound with a compound having hydroxyl and (meth)acryloyloxy groups can be cited.

[0222] Examples of polyisocyanate compounds include difunctional to quinafunctional polyisocyanate compounds, with difunctional or trifunctional polyisocyanate compounds being preferred.

[0223] Examples of polyisocyanate compounds include those described in polymer A above.

[0224] As a compound having a hydroxyl group and a (meth)acryloyloxy group, it is preferred to have a compound having one hydroxyl group and one or more (meth)acryloyloxy groups, and more preferably to have a compound having one hydroxyl group and two or more (meth)acryloyloxy groups.

[0225] Examples of compounds having hydroxyl and (meth)acryloyloxy groups include hydroxyethyl (meth)acrylate, glycerol di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate.

[0226] As a urethane (meth)acrylate compound, for example, it is preferred to be a compound having at least a group represented by the following formula (Ac-1) or formula (Ac-2), and more preferably a compound having at least a group represented by the following formula (Ac-1).

[0227] [Chemical Formula 8]

[0228]

[0229] In equations (Ac-1) and (Ac-2), L 1 ~L 4 Each group represents a divalent hydrocarbon group with 2 to 20 carbon atoms, and the wavy line indicates the bonding position with other structures.

[0230] As L 1 ~L 4Each of the alkylene compounds is preferably an alkylene compound having 2 to 20 carbon atoms, more preferably an alkylene compound having 2 to 10 carbon atoms, and even more preferably an alkylene compound having 4 to 8 carbon atoms. Furthermore, the aforementioned alkylene compounds may have branched or cyclic structures, but are preferably straight-chain alkylene compounds.

[0231] The wavy line portion in the preferred formula (Ac-1) or formula (Ac-2) is independently bonded directly to the wavy line portion in the group represented by the following formula (Ae-1) or formula (Ae-2).

[0232] [Chemical Formula 9]

[0233]

[0234] In formulas (Ae-1) and (Ae-2), R independently represents acryloyloxy or methacryloyloxy, and the wavy line portion indicates the bonding position with the wavy line portion in formulas (Ac-1) and (Ac-2).

[0235] Furthermore, as a urethane (meth)acrylate compound, a compound in which (meth)acryloyloxy groups are introduced into a polyurethane obtained by reacting a polyisocyanate compound with a polyol compound via a polymer reaction can be used. For example, a urethane (meth)acrylate compound can be obtained by reacting a compound having epoxy and (meth)acryloyloxy groups with a polyurethane oligomer obtained by reacting a polyol compound having acid groups with a polyisocyanate compound.

[0236] As a star polymer, known star polymers can be used, but star polymers having thioether bonds are preferred, and star polymers containing constituent units derived from polyfunctional thiols with 3 or more functions and 10 or fewer functions are more preferred.

[0237] Furthermore, it is preferable to have a polymer chain bonded to a thioether bond derived from the aforementioned polyfunctional thiol compound, wherein the polymer chain preferably has an olefin unsaturated group, and more preferably has a constituent unit having an olefin unsaturated group.

[0238] The star polymer preferably has only one constituent unit derived from a polyfunctional thiol compound with more than three functions and less than ten functions.

[0239] When the star polymer is a star-shaped polymer, it is preferred to be an n-star macromolecule, and n is an integer from 3 to 10.

[0240] Star polymers can be either regular star macromolecules or variegated star macromolecules.

[0241] The aforementioned star-shaped polymer can be manufactured, for example, by known methods such as copolymerization of monomers in the presence of polyfunctional thiols with 3 or more functions and 10 or fewer functions. For details regarding the manufacturing methods of the aforementioned star-shaped polymer and the aforementioned polyfunctional thiols, please refer to Japanese Patent Application Publication No. 2012-148555.

[0242] The polyfunctional thiols used in this invention are not particularly limited, but are preferably polyfunctional thiols with 3 or more functions and 8 or fewer functions, and more preferably polyfunctional thiols with 3 or more functions and 6 or fewer functions.

[0243] Furthermore, the polyfunctional thiol compound with 3 or more functions and less than 10 functions used in this invention is preferably a compound represented by the following formula S-1.

[0244] [Chemical Formula 10]

[0245]

[0246] In formula S-1, L S R represents a hydrocarbon group with an ns valence that can contain an ether bond. S It represents a 1-valent hydrocarbon group with a thiol group as a substituent, and ns represents an integer from 3 to 10.

[0247] In formula S-1, L S Preferably, it is an aliphatic hydrocarbon group with an ns valence that can contain an ether bond, and more preferably, it is an unsaturated aliphatic hydrocarbon group with an ns valence that can contain an ether bond.

[0248] As L S Specific examples include structures obtained by removing all hydroxyl groups from polyols such as pentaerythritol, dipentaerythritol, sorbitol, mannitol, idotitol, eurythritol, and inositol, but are not limited to these.

[0249] In equation S-1, R S Preferably, it is a monovalent aliphatic hydrocarbon group having a thiol group as a substituent, and more preferably, it is a monovalent unsaturated aliphatic hydrocarbon group having a thiol group as a substituent.

[0250] As R S Specific examples include mercaptomethyl, 2-mercaptoethyl, and 2-mercaptopropyl, but are not limited to these.

[0251] In formula S-1, ns represents an integer from 3 to 10, preferably an integer from 3 to 8, and more preferably an integer from 3 to 6.

[0252] In addition, as a polyfunctional thiol compound, compounds A to F as described in Japanese Patent Application Publication No. 2012-148555 are preferred.

[0253] Furthermore, there are no particular restrictions on introducing polymeric groups into star-shaped polymers; it can be done through polymer reactions or by introducing polymer chains with olefinic unsaturated groups.

[0254] As a star-shaped polymer, for example, the polymer described in International Publication No. 2019 / 151361 can be cited.

[0255] The aforementioned polymeric compound B can be used alone or in combination with two or more compounds.

[0256] From the viewpoints of developability, UV printing durability and UV plate wear inhibition, the content of the polymeric compound B in the image recording layer is preferably 0.1% to 50% by mass, more preferably 1% to 40% by mass, and especially preferably 5% to 30% by mass, relative to the total mass of the image recording layer.

[0257] -polymeric compound C-

[0258] From the viewpoint of UV printing durability and UV plate wear inhibition, the aforementioned image recording layer preferably further comprises a polymeric compound C with a molecular weight of less than 1,000. Furthermore, the polymeric compound C preferably comprises a polymeric compound with a molecular weight of 100 or more but less than 1,000.

[0259] The polymeric compound C used in this invention can be, for example, a free radical polymeric compound or a cationic polymeric compound, but is preferably a free radical polymeric compound, and more preferably a compound having an olefin unsaturated group (olefin unsaturated compound). As an olefin unsaturated compound, it is preferably a compound having at least one terminal olefin unsaturated bond, and more preferably a compound having two or more terminal olefin unsaturated bonds.

[0260] Examples of monomers include unsaturated carboxylic acids (e.g., acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), their esters, and amides. Esters of unsaturated carboxylic acids and polyols, and amides of unsaturated carboxylic acids and polyamines are preferred. Furthermore, addition reactions of unsaturated carboxylic acid esters or amides with nucleophilic substituents such as hydroxyl, amino, or thiol groups with monofunctional or polyfunctional isocyanates or epoxides, and dehydration condensation reactions with monofunctional or polyfunctional carboxylic acids are also preferred. Addition reactions of unsaturated carboxylic acid esters or amides with electrophilic substituents such as isocyanate groups or epoxy groups with monofunctional or polyfunctional alcohols, amines, or thiols are also preferred; substitution reactions of unsaturated carboxylic acid esters or amides with dissociative substituents such as halogen atoms or toluenesulfonyloxy groups with monofunctional or polyfunctional alcohols, amines, or thiols are even more preferred. Furthermore, as another example, compounds that replace the aforementioned unsaturated carboxylic acids with unsaturated phosphonic acids, styrene, vinyl ethers, etc., can also be used. These are recorded in Japanese Patent Publication No. 2006-508380, Japanese Patent Application Publication No. 2002-287344, Japanese Patent Application Publication No. 2008-256850, Japanese Patent Application Publication No. 2001-342222, Japanese Patent Application Publication No. 9-179296, Japanese Patent Application Publication No. 9-179297, Japanese Patent Application Publication No. 9-179298, Japanese Patent Application Publication No. 2004-294935, Japanese Patent Application Publication No. 2006-243493, Japanese Patent Application Publication No. 2002-275129, Japanese Patent Application Publication No. 2003-64130, Japanese Patent Application Publication No. 2003-280187, Japanese Patent Application Publication No. 10-333321, etc.

[0261] Specific examples of ester monomers of polyol compounds and unsaturated carboxylic acids, as acrylates, include ethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, trimethylolpropane triacrylate, hexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, ethylene oxide (EO) isocyanurate modified triacrylate, and polyester acrylate oligomers, etc.

[0262] Examples of methacrylates include tetramethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, pentaerythritol trimethacrylate, bis[p-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]dimethylmethane, and bis[p-(methacryloyloxyethoxy)phenyl]dimethylmethane.

[0263] Furthermore, specific examples of amide monomers of polyamine compounds and unsaturated carboxylic acids include methylenebisacrylamide, methylenebisacrylamide, 1,6-hexamethylenebisacrylamide, 1,6-hexamethylenebisacrylamide, diethylenetriaminetriacrylamide, xylylenebisacrylamide, and diphenylbisacrylamide.

[0264] Furthermore, it is preferable to produce urethane-based addition polymerizable compounds by means of the addition reaction of isocyanate and hydroxyl groups. For example, a vinyl urethane compound containing two or more polymerizable vinyl groups in one molecule, which is formed by the addition of a polyisocyanate compound having two or more isocyanate groups in one molecule to a vinyl monomer containing hydroxyl groups represented by the following formula (M), as described in Japanese Patent Publication No. 48-41708.

[0265] CH2=C(R) M4 COOCH2CH(R) M5 OH (M)

[0266] In formula (M), R M4 and R M5 Each can be used to represent a hydrogen atom or a methyl group independently.

[0267] Furthermore, the preferred materials are the urethane acrylates described in Japanese Patent Application Publication No. 51-37193, Japanese Patent Publication No. 2-32293, Japanese Patent Publication No. 2-16765, Japanese Patent Application Publication No. 2003-344997, Japanese Patent Application Publication No. 2006-65210, Japanese Patent Application Publication No. 58-49860, Japanese Patent Application Publication No. 56-17654, Japanese Patent Application Publication No. 62-39417, and Japanese Patent Application Publication No. 62. Carbamate compounds having an ethylene oxide backbone as described in Japanese Patent Application Publication No. 39418, Japanese Patent Application Publication No. 2000-250211, Japanese Patent Application Publication No. 2007-94138, US Patent No. 7153632, Japanese Patent Application Publication No. 8-505958, Japanese Patent Application Publication No. 2007-293221, and Japanese Patent Application Publication No. 2007-293223, and carbamate compounds having hydrophilic groups.

[0268] As a polymeric compound C, it may contain compounds having one or two olefinic unsaturated groups (hereinafter also referred to as specific compound B2).

[0269] The polymerizable group in a specific compound B2 can be, for example, a cationic polymerizable group or a free radical polymerizable group, but from the viewpoint of reactivity, a free radical polymerizable group is preferred.

[0270] There are no particular limitations on the polymerizable groups mentioned above, but from the viewpoint of reactivity and print durability, olefinic unsaturated groups are preferred, more preferably at least one group selected from the group consisting of vinylphenyl (styrene), vinyl ester, vinyl ether, allyl, (meth)acryloyloxy and (meth)acrylamide, and even more preferably at least one group selected from the group consisting of vinylphenyl (styrene), (meth)acryloyloxy and (meth)acrylamide, especially (meth)acryloyloxy.

[0271] Furthermore, the specific compound B2 is preferably a compound having two olefinic unsaturated groups (i.e., a 2-functional polymeric compound).

[0272] From the viewpoint of machine developability and printing durability, the preferred compound B2 is a methacrylate compound, i.e. a compound having a methacryloyloxy group.

[0273] From the viewpoint of machine developability, it is preferable that the compound B2 contains an alkene structure or a carbamate bond.

[0274] The molecular weight (weight-average molecular weight in the case of a molecular weight distribution) of the specific compound B2 is preferably 50 or more and less than 1,000, more preferably 200 to 900, and even more preferably 250 to 800.

[0275] Specific examples of a particular compound B2 are given below, but the specific compound B2 used in this invention is not limited to these. In addition, in the compounds described in (2) below, for example, n+m=10.

[0276] [Chemical Formula 11]

[0277]

[0278] As a specific compound B2, commercially available products shown below can be used, but the specific compound B2 used in this invention is not limited to these.

[0279] Specific examples of the particular compound B2 include ethoxylated bisphenol A dimethacrylates such as BPE-80N (the compound mentioned in (1)) manufactured by Shin-Nakamura Chemical Co., Ltd., BPE-100, BPE-200, BPE-500, and CN104 (the compound mentioned in (1)) manufactured by Sartomer Company, Inc.

[0280] Furthermore, as specific examples of the particular compound B2, examples include ethoxylated bisphenol A diacrylates such as A-BPE-10 (the compound mentioned in (2) above) and A-BPE-4 manufactured by Shin-Nakamura Chemical Co., Ltd.

[0281] Furthermore, as a specific example of compound B2, one could cite difunctional methacrylates such as FST 510 manufactured by AZ Electronics.

[0282] Here, “FST 510” is the reaction product of 1 mole of 2,2,4-trimethylhexamethylene diisocyanate and 2 moles of hydroxyethyl methacrylate, and is an 82% by mass solution of the compound in (3) above in methyl ethyl ketone.

[0283] From the viewpoint of machine developability and printing durability, the content of the specific compound B2 is preferably 1% to 60% by mass relative to the total mass of the image recording layer, more preferably 5% to 55% by mass, and even more preferably 5% to 50% by mass.

[0284] The polymeric compound C mentioned above can be used alone or in combination with two or more compounds.

[0285] From the viewpoints of developability, UV printing durability, and UV plate wear inhibition, the content of the polymeric compound C in the image recording layer is preferably 1% to 75% by mass, more preferably 3% to 70% by mass, and especially preferably 5% to 60% by mass, relative to the total mass of the image recording layer.

[0286] -Infrared absorber-

[0287] The image recording layer described above contains an infrared absorber.

[0288] There are no particular limitations on what can be used as an infrared absorber; for example, pigments and dyes can be cited.

[0289] As dyes that can be used as infrared absorbers, commercially available dyes and well-known dyes as described in publications such as "Dye Handbook" (The Society of Synthetic Organic Chemistry, Japan, 1955). Specifically, examples include azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methylene dyes, anthocyanin dyes, squaric acid cyanine pigments, pyranium salts, and metal thiol complexes.

[0290] Among these dyes, anthocyanins, quaternium cyanines, pyranium salts, nickel thiol complexes, and indocyanines are particularly preferred. Anthocyanins and indocyanines are also examples. Anthocyanins are especially preferred.

[0291] As the aforementioned infrared absorber, cationic polymethyl pigments having oxygen or nitrogen atoms at the meta position are preferred. Examples of cationic polymethyl pigments include anthocyanins, pyranonium pigments, thiopyridinium pigments, and azurites; from the viewpoints of ease of acquisition and solvent solubility during the induction reaction, anthocyanins are preferred.

[0292] Specific examples of anthocyanins include compounds described in paragraphs 0017-0019 of Japanese Patent Application Publication No. 2001-133969, paragraphs 0016-0021 of Japanese Patent Application Publication No. 2002-023360, and paragraphs 0012-0037 of Japanese Patent Application Publication No. 2002-040638. Preferably, compounds described in paragraphs 0034-0041 of Japanese Patent Application Publication No. 2002-278057 and paragraphs 0080-0086 of Japanese Patent Application Publication No. 2008-195018 are included. Particularly preferred are compounds described in paragraphs 0035-0043 of Japanese Patent Application Publication No. 2007-90850 and paragraphs 0105-0113 of Japanese Patent Application Publication No. 2012-206495.

[0293] Furthermore, compounds described in Japanese Patent Application Publication No. 5-5005, paragraphs 0008-0009, and Japanese Patent Application Publication No. 2001-222101, paragraphs 0022-0025, are preferred.

[0294] As a pigment, compounds described in paragraphs 0072 to 0076 of Japanese Patent Application Publication No. 2008-195018 are preferred.

[0295] Infrared absorbers can be used in single-agent or multi-agent applications. Furthermore, pigments and dyes can be used simultaneously as infrared absorbers.

[0296] The content of the infrared absorber in the image recording layer is preferably 0.1% to 10.0% by mass relative to the total mass of the image recording layer, more preferably 0.5% to 5.0% by mass.

[0297] -Polymerization initiator-

[0298] The image recording layer in the lithographic printing plate original involved in this invention contains a polymerization initiator.

[0299] Furthermore, the polymerization initiator preferably includes an electron-accepting polymerization initiator, and more preferably includes both an electron-accepting polymerization initiator and an electron-donating polymerization initiator.

[0300] <<Electron-accepting polymerization initiators>>

[0301] The image recording layer described above preferably includes an electron-accepting polymerization initiator as a polymerization initiator.

[0302] Electron-accepting polymerization initiators are compounds that, when exposed to infrared light and the electrons of the infrared absorber are excited, accept an electron through intermolecular electron migration to generate free radicals and other polymerization initiators.

[0303] The electron-accepting polymerization initiator used in this invention is a compound that generates polymerization initiators such as free radicals or cations through the energy of light, heat or both, and can appropriately select and use known thermal polymerization initiators, compounds with bonds having low bond dissociation energy, photopolymerization initiators, etc.

[0304] As an electron-accepting polymerization initiator, a free radical polymerization initiator is preferred, and an onium salt compound is more preferred.

[0305] Furthermore, an infrared-sensitive polymerization initiator is preferred as the electron-receiving polymerization initiator.

[0306] Examples of electron-accepting free radical polymerization initiators include (a) organohalides, (b) carbonyl compounds, (c) azo compounds, (d) organic peroxides, (e) metallocene compounds, (f) azide compounds, (g) hexaaryl biimidazole compounds, (i) disulfone compounds, (j) oxime ester compounds, and (k) onium salt compounds.

[0307] (a) As an organohalide, the compounds described in paragraphs 0022 to 0023 of Japanese Patent Application Publication No. 2008-195018 are preferred, for example.

[0308] (b) As a carbonyl compound, the compounds described in paragraph 0024 of Japanese Patent Application Publication No. 2008-195018 are preferred, for example.

[0309] (c) As an azo compound, for example, the azo compound described in Japanese Patent Application Publication No. 8-108621 can be used.

[0310] (d) As an organic peroxide, the compounds described in paragraph 0025 of Japanese Patent Application Publication No. 2008-195018 are preferred, for example.

[0311] (e) As a metallocene compound, the compounds described in paragraph 0026 of Japanese Patent Application Publication No. 2008-195018 are preferred, for example.

[0312] (f) Examples of azide compounds include 2,6-bis(4-azidobenzylidene)-4-methylcyclohexanone.

[0313] (g) As a hexaaryl biimidazole compound, the compound described in paragraph 0027 of Japanese Patent Application Publication No. 2008-195018 is preferred.

[0314] (i) As disulfone compounds, examples include compounds described in Japanese Patent Application Publication No. 61-166544 and Japanese Patent Application Publication No. 2002-328465.

[0315] (j) As an oxime ester compound, the compounds described in paragraphs 0028 to 0030 of Japanese Patent Application Publication No. 2008-195018 are preferred, for example.

[0316] Among the aforementioned electron-accepting polymerization initiators, oxime ester compounds and onium salt compounds are preferred from the viewpoint of curability. Of these, iodonium salt compounds, sulfonium salt compounds, or azazine onium salt compounds are preferred from the viewpoint of print durability, iodonium salt compounds or sulfonium salt compounds are more preferred, and iodonium salt compounds are particularly preferred.

[0317] Specific examples of these compounds are shown below, but the invention is not limited thereto.

[0318] Examples of iodonium salt compounds include diaryl iodonium salt compounds, especially, more preferably, diphenyl iodonium salt compounds obtained by substitution with electron-donating groups, such as alkyl or alkoxy groups, and asymmetric diphenyl iodonium salt compounds. Specific examples include diphenyliodonium (hexafluorophosphate), 4-methoxyphenyl-4-(2-methylpropyl)phenyliodonium (hexafluorophosphate), 4-(2-methylpropyl)phenyl-p-tolyliodonium (hexafluorophosphate), 4-hexyloxyphenyl-2,4,6-trimethoxyphenyliodonium (hexafluorophosphate), 4-hexyloxyphenyl-2,4-diethoxyphenyliodonium (tetrafluoroborate), 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium (1-perfluorobutylsulfonate), 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium (hexafluorophosphate), and bis(4-tert-butylphenyl)iodonium (tetraphenylborate).

[0319] Examples of sulfonium salt compounds include triarylsulfonium salt compounds, particularly those obtained by substituting at least a portion of electron-withdrawing groups, such as those on the aromatic ring, with halogen atoms. More preferably are triarylsulfonium salt compounds with a total number of halogen atoms substituting four or more on the aromatic ring. Specific examples include triphenylsulfonium hexafluorophosphate, triphenylsulfonium benzoylcarbamate, bis(4-chlorophenyl)phenylsulfonium benzoylcarbamate, bis(4-chlorophenyl)-4-methylphenylsulfonium tetrafluoroborate, tri(4-chlorophenyl)sulfonium 3,5-bis(methoxycarbonyl)benzenesulfonate, tri(4-chlorophenyl)sulfonium hexafluorophosphate, and tri(2,4-dichlorophenyl)sulfonium hexafluorophosphate.

[0320] Furthermore, examples of counter anions of iodonium salts and sulfonium salts include sulfonate anions, carboxylate anions, tetrafluoroborate anions, hexafluorophosphate anions, p-toluenesulfonate anions, p-toluenesulfonate anions, sulfonamide anions, or sulfonamide anions.

[0321] Of the above, sulfonamide anion or sulfonamide anion is preferred, and sulfonamide anion is more preferred.

[0322] As a sulfonamide anion, arylsulfonamide anion is preferred.

[0323] Furthermore, bis(aryl)sulfonamide anion is preferred as the sulfonamide anion.

[0324] The following are specific examples of sulfonamide anions or sulfonamide anions, but the invention is not limited to these. In the following specific examples, Ph represents phenyl, Me represents methyl, and Et represents ethyl.

[0325] [Chemical Formula 12]

[0326]

[0327] Furthermore, as the aforementioned electron-receiving polymerization initiator, from the viewpoint of the time-lapse visual recognizability after exposure, the developability, and the UV printing durability in the obtained lithographic printing plate, it is preferable to include a compound represented by formula (II) or formula (III) below, and it is particularly preferable to include a compound represented by formula (II).

[0328] [Chemical Formula 13]

[0329]

[0330] In equations (II) and (III), X A R represents a halogen atom. A R A1 and R A2Each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms.

[0331] R in formula (II) A is preferably an aryl group.

[0332] As X in formula (II) and formula (III) A , a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be cited. Among these, regarding the chlorine atom or the bromine atom, since the sensitivity is excellent, it is preferably used, and the bromine atom is particularly preferably used.

[0333] Moreover, in formula (II) and formula (III), R A , R A1 and R A2 are each independently preferably an aryl group, 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.

[0334] Moreover, as the above-mentioned electron-accepting type polymerization initiator, a compound represented by formula (IV) is particularly preferably included.

[0335] [Chemical formula 14]

[0336]

[0337] 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.

[0338] As a specific example of the electron-accepting type polymerization initiator, compounds shown below etc. can be cited, but the present invention is not limited to these. In addition, in the compounds shown below, Et represents an ethyl group, n Pr represents a n-propyl group, n C4H9 represents a n-butyl group, cHex represents a cyclohexyl group, n C5H 11 represents a n-pentyl group, t C5H 11 represents a tert-pentyl group, Ph represents a phenyl group, n C8H 17 represents a n-octyl group, t Bu represents a tert-butyl group, n Bu represents a n-butyl group, n C 12 H 25 represents a n-decyl group.

[0339] [Chemical formula 15]

[0340]

[0341] [Chemical Formula 16]

[0342]

[0343] [Chemical Formula 17]

[0344]

[0345] [Chemical Formula 18]

[0346]

[0347] [Chemical Formula 19]

[0348]

[0349] [Chemical Formula 20]

[0350]

[0351] [Chemical Formula 21]

[0352]

[0353] From the viewpoint of improving sensitivity and reducing wear, the minimum unoccupied molecular orbital (LUMO) of the electron-receiving polymerization initiator is preferably -3.00 eV or less, more preferably -3.02 eV or less.

[0354] Furthermore, as a lower limit, it is preferably -3.80 eV or higher, and more preferably -3.60 eV or higher.

[0355] Electron-accepted polymerization initiators can be used alone or in combination with two or more.

[0356] The content of the electron-receiving polymerization initiator is preferably 0.1% to 50% by mass relative to the total mass of the image recording layer, more preferably 0.5% to 30% by mass, and especially preferably 0.8% to 20% by mass.

[0357] <<Electron-donating polymerization initiators (polymerization aids)>>

[0358] The aforementioned image recording layer preferably includes an electron-donating polymerization initiator (also referred to as a "polymerization aid") as a polymerization initiator, and more preferably includes both an electron-accepting polymerization initiator and an electron-donating polymerization initiator.

[0359] The electron-donating polymerization initiator in this invention is a compound that generates a polymerization initiator such as a free radical by supplying an electron to the orbit of an electron detached from the infrared absorber through intermolecular electron migration when the electron of the infrared absorber is excited or moves within the molecule during infrared exposure.

[0360] As an electron-donating polymerization initiator, an electron-donating free radical polymerization initiator is preferred.

[0361] From the viewpoint of improving the printing durability of offset printing plates, it is more preferable that the above-mentioned image recording layer contains an electron-donating polymerization initiator as described below, and the following five examples can be cited as examples.

[0362] (i) Alkyl or arylate complexes: These are considered to be carbon-heterobonds that undergo oxidative cleavage, generating active free radicals. Specifically, borate compounds are preferred.

[0363] (ii) N-arylalkylamine compounds: These are thought to generate an active free radical through oxidation, resulting in the cleavage of the CX bond on the carbon adjacent to nitrogen. Preferably, X is a hydrogen atom, a carboxyl group, a trimethylsilyl group, or a benzyl group. Specifically, examples include N-phenylglycines (which may or may not have substituents in the phenyl group) and N-phenyliminodiacetic acids (which may or may not have substituents in the phenyl group).

[0364] (iii) Sulfur-containing compounds: Compounds formed by replacing the nitrogen atom of the above-mentioned amines with a sulfur atom can generate active free radicals through the same process. For example, phenylthioacetic acid (which may or may not have substituents in the phenyl group) can be cited.

[0365] (iv) Tin-containing compounds: Compounds formed by replacing the nitrogen atoms of the above-mentioned amines with tin atoms can generate active free radicals through the same action.

[0366] (v) Sulfites: These can generate reactive free radicals through oxidation. Examples include sodium arylsulfite.

[0367] From the viewpoint of print durability, the image recording layer preferably contains a borate compound.

[0368] From the viewpoint of print durability and color development, tetraarylborate compounds or monoalkyltriarylborate compounds are preferred as borate compounds, and tetraarylborate compounds are more preferred.

[0369] There are no particular limitations on the counter cations present in borate compounds, but alkali metal ions or tetraalkylammonium ions are preferred, and sodium ions, potassium ions or tetrabutylammonium ions are more preferred.

[0370] As a borate compound, sodium tetraphenylborate is particularly preferred.

[0371] The following are specific examples of B-1 to B-9 as preferred electron-donating polymerization initiators, but naturally, they are not limited to these. Furthermore, in the following chemical formulas, Ph represents phenyl and Bu represents n-butyl.

[0372] [Chemical Formula 22]

[0373]

[0374] Furthermore, from the viewpoint of improving sensitivity and reducing the likelihood of plate wear, the highest occupied orbital (HOMO) of the electron-donating polymerization initiator used in this invention is preferably -6.00 eV or more, more preferably -5.95 eV or more, and even more preferably -5.93 eV or more.

[0375] Furthermore, as an upper limit, it is preferably below -5.00 eV, and more preferably below -5.40 eV.

[0376] One type of electron-donating polymerization initiator can be added, or two or more can be used simultaneously.

[0377] From the viewpoint of sensitivity and printing durability, the content of the electron-donating polymerization initiator is preferably 0.01% to 30% by mass relative to the total mass of the image recording layer, more preferably 0.05% to 25% by mass, and even more preferably 0.1% to 20% by mass.

[0378] In this invention, when the image recording layer contains onium ions and the anions in the electron-donating polymerization initiator described above, the image recording layer contains both an electron-accepting polymerization initiator and the electron-donating polymerization initiator described above.

[0379] -Relationship between electron-donating polymerization initiators and infrared absorbers-

[0380] From the viewpoint of improving sensitivity and UV plate wear suppression, the image recording layer of the present invention contains the above-mentioned electron-donating polymerization initiator and infrared absorber. The HOMO value of the infrared absorber - the HOMO value of the above-mentioned electron-donating polymerization initiator is preferably 0.70 eV or less, more preferably 0.70 eV to -0.10 eV.

[0381] Additionally, a negative value indicates that the HOMO of the aforementioned electron-donating polymerization initiator is higher than that of the infrared absorber.

[0382] -Preferred methods for infrared absorbers and electron-accepting polymerization initiators-

[0383] From the viewpoint of improving sensitivity and reducing wear, the preferred infrared absorber in this invention is an organic anion having a Hansen solubility parameter of δd of 16 or more, δp of 16 to 32, and δh of δp of 60% or less.

[0384] As the electron-accepting polymerization initiator in this invention, from the viewpoint of improving sensitivity and reducing the likelihood of plate wear, it is preferably an organic anion having a Hansen solubility parameter of δd of 16 or more, δp of 16 to 32, and δh of δp of 60% or less.

[0385] Here, the δd, δp, and δh in the Hansen solubility parameters of this invention use the dispersion term δd [unit: MPa] from the Hansen solubility parameters. 0.5 and polarity term δp [unit: MPa] 0.5 Here, regarding the Hansen solubility parameters, the solubility parameters imported by Hildebrand are divided into three components: dispersion term δd, polarity term δp, and hydrogen bonding term δh, and are shown in three-dimensional space.

[0386] Detailed information about Hansen solubility parameters is available in the literature "Hansen Solubility Parameters; A Users Handbook" edited by Charles M. Hansen (CRC Press, 2007).

[0387] In this invention, the values ​​δd, δp, and δh of the above-mentioned organic anions in the Hansen solubility parameters are calculated based on their chemical structures using the computer software "Hansen Solubility Parameters in Practice (HSPiP ver.4.1.07)".

[0388] Specific examples of organic anions for which the solubility parameters of Hansen are δd = 16 or more, δp = 16 to 32, and δh = 60% or less of δp are preferably examples of anions I-1 to I-15, I-17 to I-21, and I-23 to I-25 and below, but are of course not limited to these. Among these, bis(halogen-substituted benzenesulfonyl)imide anions are more preferred, and I-5 is particularly preferred.

[0389] [Chemical Formula 23]

[0390]

[0391] -particle-

[0392] From the viewpoint of UV printing durability and UV plate wear inhibition, the aforementioned image recording layer preferably contains particles.

[0393] The particles can be organic or inorganic, but from the viewpoint of UV printing durability and UV plate wear inhibition, it is preferable to include organic particles, and more preferably to include polymer particles other than polymer A.

[0394] As inorganic particles, known inorganic particles can be used, and metal oxide particles such as silicon dioxide particles and titanium dioxide particles can be preferred.

[0395] The polymer particles are preferably selected from the group consisting of thermoplastic polymer particles, thermally reactive polymer particles, polymer particles having polymeric groups, microcapsules containing hydrophobic compounds, and microgels (crosslinked polymer particles). Among these, polymer particles or microgels having polymeric groups are preferred. In a particularly preferred embodiment, the polymer particles contain at least one olefinically unsaturated polymeric group. The presence of such polymer particles improves the printing durability of the exposed portion and the on-machine developability of the unexposed portion.

[0396] Furthermore, thermoplastic polymer particles are preferred.

[0397] Thermoplastic polymer particles are preferably those described in Research Disclosure No. 33303 (January 1992), Japanese Patent Application Publication No. 9-123387, Japanese Patent Application Publication No. 9-131850, Japanese Patent Application Publication No. 9-171249, Japanese Patent Application Publication No. 9-171250, and European Patent No. 931647.

[0398] Specific examples of polymers constituting thermoplastic polymer particles include homopolymers or prepolymers or mixtures thereof 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, etc. Copolymers comprising polystyrene, styrene, and acrylonitrile, or polymethyl methacrylate, are preferred examples. The average particle size of the thermoplastic polymer particles is preferably 0.01 μm to 3.0 μm.

[0399] Examples of thermally reactive polymer particles include polymer particles with thermally reactive groups. These particles form hydrophobic regions through crosslinking based on thermal reactions and changes in functional groups during crosslinking.

[0400] The thermally reactive groups in polymer particles can be functional groups that can form chemical bonds and undergo any reaction, but polymerizable groups are preferred. Examples of such groups include olefinic unsaturated groups (e.g., acryloyl, methacryl, vinyl, allyl, etc.) that undergo free radical polymerization, cationic polymerizable groups (e.g., vinyl, ethyleneoxy, epoxy, oxetyl, etc.), isocyanate groups or their blocks that undergo addition reactions, epoxy, ethyleneoxy groups, and functional groups having active hydrogen atoms as the target of these reactions (e.g., amino, hydroxyl, carboxyl, etc.), carboxyl groups that undergo condensation reactions and hydroxyl or amino groups as the target of the reaction, and acid anhydrides that undergo ring-opening addition reactions and amino or hydroxyl groups as the target of the reaction.

[0401] Examples of microcapsules include those described in Japanese Patent Application Publications Nos. 2001-277740 and 2001-277742, which contain at least a portion of the components of an image recording layer inside the microcapsule. The components of the image recording layer may also be present outside the microcapsule. A preferred embodiment of the image recording layer containing microcapsules is a structure in which a hydrophobic component is present inside the microcapsule, and a hydrophilic component is present outside the microcapsule.

[0402] Microgels (crosslinked polymer particles) may contain at least a portion of the components of an image recording layer on their surface or within. In particular, from the viewpoint of the sensitivity of the obtained lithographic printing plate and the printing durability of the obtained lithographic printing plate, reactive microgels having free radical polymerizable groups on their surface are preferred.

[0403] Known methods can be used to microencapsulate or microgel the components of this image recording layer.

[0404] Furthermore, from the viewpoint of the printing durability, stain resistance and storage stability of the obtained lithographic printing plate, polymer particles obtained by reacting a polyisocyanate compound having two or more hydroxyl groups in the molecule with an adduct of isophorone diisocyanate and a compound having active hydrogen are preferred.

[0405] As the aforementioned polyphenolic compounds, compounds having multiple benzene rings with phenolic hydroxyl groups are preferred.

[0406] As a compound having the aforementioned active hydrogen, a polyol compound or a polyamine compound is preferred, a polyol compound is more preferred, and at least one compound selected from the group consisting of propylene glycol, glycerol and trimethylolpropane is even more preferred.

[0407] As for the resin particles obtained by reacting a polyisocyanate compound, which is an adduct of a polyphenol compound having two or more hydroxyl groups in the molecule and an isophorone diisocyanate, the polymer particles described in paragraphs 0032 to 0095 of Japanese Patent Application Publication No. 2012-206495 are preferred examples.

[0408] Furthermore, from the viewpoint of the printability and solvent resistance of the obtained lithographic printing plate, it is preferable that the polymer particles have a hydrophobic backbone and include both i) a constituent unit having a side cyano group directly bonded to the hydrophobic backbone and ii) a constituent unit having a side group containing a hydrophilic polyoxyalkylene segment.

[0409] An acrylic resin chain is preferably used as the hydrophobic backbone mentioned above.

[0410] Examples of the aforementioned side cyano groups are preferably -[CH2CH(C≡N)]- or -[CH2C(CH3)(C≡N)]-.

[0411] Furthermore, the constituent units having the aforementioned side cyano groups can be readily derived from olefinic unsaturated monomers, such as acrylonitrile or methacrylonitrile or combinations thereof.

[0412] Furthermore, the epoxide in the hydrophilic polyepoxide chain segment is preferably ethylene oxide or propylene oxide, and more preferably ethylene oxide.

[0413] The number of repeating epoxide structures in the above-mentioned hydrophilic polyepoxide segments is preferably 10 to 100, more preferably 25 to 75, and even more preferably 40 to 50.

[0414] As for the particles of a resin having a hydrophobic main chain and comprising i) a constituent unit having a side cyano group directly bonded to the hydrophobic main chain and ii) a constituent unit having a side group containing a hydrophilic polyoxyalkylene segment, the particles described in paragraphs 0039 to 0068 of Japanese Patent Application Publication No. 2008-503365 are preferred examples.

[0415] Furthermore, from the viewpoint of UV printing durability and machine developability, the aforementioned polymer particles preferably have hydrophilic groups.

[0416] As for the aforementioned hydrophilic groups, there are no particular restrictions on the structure that has hydrophilicity, but examples include acid groups such as carboxyl groups, hydroxyl groups, amino groups, cyano groups, and polyepoxide structures.

[0417] From the viewpoints of machine developability, UV printing durability and UV plate wear inhibition, polyepoxide structure is preferred, and polyethylene oxide structure, polypropylene oxide structure or polyethylene / propylene oxide structure is more preferred.

[0418] Furthermore, from the viewpoint of machine developability and the ability to suppress developing residues during machine development, the aforementioned polyoxyethylene structure is preferably a polyoxypropylene structure, and more preferably a polyoxyethylene structure and a polyoxypropylene structure.

[0419] Furthermore, from the viewpoint of print durability, ink adhesion and machine developability, the hydrophilic group preferably contains a constituent unit having a cyano group or a group represented by the following formula Z, more preferably contains a constituent unit represented by the following formula (AN) or a group represented by the following formula Z, and especially preferably contains a group represented by the following formula Z.

[0420] *-QWY formula Z

[0421] In formula Z, Q represents a divalent linking group, W represents a divalent group with a hydrophilic structure or a divalent group with a hydrophobic structure, Y represents a monovalent group with a hydrophilic structure or a monovalent group with a hydrophobic structure, either W or Y has a hydrophilic structure, and * represents the bonding site with other structures.

[0422] [Chemical Formula 24]

[0423]

[0424] In formula (AN), R AN It represents a hydrogen atom or a methyl group.

[0425] From the viewpoint of UV printing durability, the polymer contained in the above-mentioned polymer particles preferably contains constituent units formed from compounds having cyano groups.

[0426] The cyano group is typically introduced using a compound (monomer) containing a cyano group as the constituent unit. Examples of compounds containing a cyano group include acrylonitrile compounds, with (meth)acrylonitrile being a preferred example.

[0427] As a constituent unit having a cyano group, it is preferably a constituent unit formed from an acrylonitrile compound, more preferably a constituent unit formed from (meth)acrylonitrile, that is, a constituent unit represented by the above formula (AN).

[0428] When the above-mentioned polymer includes a polymer having a cyano group, from the viewpoint of UV printing durability, the content of the cyano group in the polymer having the cyano group, preferably the group represented by the above formula (AN), is preferably 5% to 90% by mass, more preferably 20% to 80% by mass, and especially preferably 30% to 60% by mass, relative to the total mass of the polymer having the cyano group.

[0429] From the viewpoint of UV printing durability, the aforementioned polymer particles preferably contain constituent units formed of aromatic vinyl compounds.

[0430] As an aromatic vinyl compound, any compound having a structure in which a vinyl group is bonded to an aromatic ring is acceptable, but examples include styrene compounds, vinylnaphthalene compounds, etc., with styrene compounds being preferred, and styrene being more preferred.

[0431] Examples of styrene compounds include styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, and p-methoxy-β-methylstyrene, with styrene being the preferred example.

[0432] Examples of vinylnaphthalene compounds include 1-vinylnaphthalene, methyl-1-vinylnaphthalene, β-methyl-1-vinylnaphthalene, 4-methyl-1-vinylnaphthalene, and 4-methoxy-1-vinylnaphthalene, with 1-vinylnaphthalene being the most preferred.

[0433] Furthermore, as a constituent unit formed from aromatic vinyl compounds, a constituent unit represented by the following formula Z1 is preferably cited.

[0434] [Chemical Formula 25]

[0435]

[0436] In equation Z1, R Z1 and R Z2 Each can be used independently to represent a hydrogen atom or an alkyl group; Ar represents an aromatic cyclic group; R Z3 denoted by substituent, nz represents an integer greater than 0 and less than the maximum number of substituents for Ar.

[0437] In equation Z1, R Z1 and R Z2 Each of the following is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably both hydrogen atoms.

[0438] In formula Z1, Ar is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring.

[0439] In equation Z1, R Z3 Preferably, it is an alkyl or alkoxy group, more preferably an alkyl or alkoxy group having 1 to 4 carbon atoms, and even more preferably a methyl or methoxy group.

[0440] In equation Z1, when there are multiple R Z3 In the case of multiple R Z3 They can be the same, or they can be different.

[0441] In formula Z1, nz is preferably an integer from 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0442] The polymer particles described above may contain only one type of constituent unit formed from an aromatic vinyl compound, or they may contain two or more types.

[0443] From the viewpoint of ink adhesion, the content of constituent units formed by aromatic vinyl compounds in the polymer particles is preferably 0.1% to 20% by mass, more preferably 0.5% to 15% by mass, and particularly preferably 1% to 10% by mass, relative to the total mass of the polymer particles.

[0444] Furthermore, from the viewpoint of UV printing durability, the polymer particles preferably have a cross-linked structure, and more preferably contain constituent units with a cross-linked structure.

[0445] It is believed that the hardness of the polymer particles themselves is improved by the cross-linked structure of the polymer particles, thus improving the strength of the image area. Even when using UV-curable inks that are more likely to degrade the plate than other inks, the printing durability (UV printing durability) is further improved.

[0446] There are no particular limitations on the aforementioned crosslinking structure, but it is preferable to be a constituent unit formed by polymerizing a polyfunctional olefin unsaturated compound or a constituent unit in which one or more reactive groups form covalent bonds with each other within the particle. From the viewpoint of UV printing durability and machine developability, the functional number of the aforementioned polyfunctional olefin unsaturated compound is preferably 2 to 15, more preferably 3 to 10, further preferably 4 to 10, and especially preferably 5 to 10.

[0447] Furthermore, in other words, from the viewpoint of UV printing durability and machine developability, the constituent unit having the above-mentioned crosslinking structure is preferably a 2- to 15-functional branch unit.

[0448] In addition, an n-functional branching unit refers to a branching unit that branches out into n molecular chains. In other words, it is a constituent unit with n functional branching points (cross-linked structures).

[0449] Furthermore, cross-linked structures formed by multifunctional thiol compounds are also preferred examples.

[0450] There are no particular limitations on the olefinic unsaturated groups in the above-mentioned polyfunctional olefinic unsaturated compounds, but examples include (meth)acryloyloxy, (meth)acrylamido, aromatic vinyl, maleimide, etc.

[0451] Furthermore, the aforementioned polyfunctional olefinic unsaturated compounds are preferably polyfunctional (meth)acrylate compounds, polyfunctional (meth)acrylamide compounds, or polyfunctional aromatic vinyl compounds.

[0452] Examples of polyfunctional (meth)acrylate compounds include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, tricyclodecanediethanol diacrylate, bis(trimethylolpropane)tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol triacrylate, dipentaerythritol hexaacrylate, and triacrylates of tri(β-hydroxyethyl)isocyanurate.

[0453] Examples of polyfunctional (meth)acrylate compounds include N,N'-methylenebisacrylamide and N-[tris(3-acrylamidopropoxymethyl)methyl]acrylamide.

[0454] Examples of polyfunctional aromatic vinyl compounds include divinylbenzene.

[0455] There is no particular limitation on the number of carbon atoms in the aforementioned branching units, but it is preferably 8 to 100, and more preferably 8 to 70.

[0456] The polymer particles described above may contain one type of cross-linked structural unit or two or more types.

[0457] From the viewpoint of UV printing durability and machine developability, the content of the constituent units having cross-linked structures in the above polymer particles is preferably 0.1% to 20% by mass, more preferably 0.5% to 15% by mass, and particularly preferably 1% to 10% by mass, relative to the total mass of the above polymer particles.

[0458] Furthermore, from the viewpoints of printability, ink adhesion, and machine developability, the polymer particles preferably include polymer particles having groups represented by the above formula Z.

[0459] In the above formula Z, Q is preferably a divalent linking group with 1 to 20 carbon atoms, and more preferably a divalent linking group with 1 to 10 carbon atoms.

[0460] Furthermore, Q in the above formula Z is preferably an alkylene group, an aryl group, an ester bond, an amide bond, or a combination of two or more of them, and more preferably a phenylene group, an ester bond, or an amide bond.

[0461] The divalent group with a hydrophilic structure in W of formula Z above is preferably polyalkoxide or has -CH2CH2NR bonded to one end of the polyalkoxide. W - group. Additionally, R W It represents a hydrogen atom or an alkyl group.

[0462] The divalent group with a hydrophobic structure in W of formula Z above is preferably -R. WA -、-OR WA -O-、-R W NR WA -NR W -、-OC(=O)-R WA -O-or-OC(=O)-R WA -O-. Also, R WA Each of these can be independently represented as a straight-chain, branched, or cyclic alkylene group with 6 to 120 carbon atoms, a haloalkylene group with 6 to 120 carbon atoms, an aryl group with 6 to 120 carbon atoms, an alkarylene group (a divalent group obtained by removing one hydrogen atom from an alkylaryl group) with 7 to 120 carbon atoms, or an aryl group with 7 to 120 carbon atoms.

[0463] The monovalent group with a hydrophilic structure in Y of formula Z above is preferably -OH, -C(=O)OH, a polyalkoxide group with a hydrogen atom or alkyl group at the end, or a polyalkoxide group with -CH2CH2N(R) bonded to the other end. W )- group.

[0464] The monovalent group with a hydrophobic structure in Y of formula Z above is preferably a straight-chain, branched, or cyclic alkyl group with 6 to 120 carbon atoms, a haloalkyl group with 6 to 120 carbon atoms, an aryl group with 6 to 120 carbon atoms, an alkylaryl group (alkylaryl group) with 7 to 120 carbon atoms, an aralkyl group with 7 to 120 carbon atoms, or an -OR group. WB -C (=O) OR WB or -OC (=O)R WB R WB This refers to alkyl groups having 6 to 20 carbon atoms.

[0465] In polymer particles having groups represented by the above formula Z, from the viewpoint of printability, ink adhesion and machine developability, it is more preferable that W is a divalent group with a hydrophilic structure, more preferably that Q is a phenylene, ester bond or amide bond, W is a polyalkoxide group, and Y is a polyalkoxide group with a hydrogen atom or alkyl end.

[0466] Furthermore, from the viewpoints of printing durability, ink adhesion, UV plate abrasion suppression, and on-machine developability, the aforementioned polymer particles preferably include polymer particles having polymeric groups, and more preferably include polymer particles having polymeric groups on the particle surface.

[0467] Furthermore, from the viewpoint of print durability, the polymer particles mentioned above preferably include polymer particles having both hydrophilic and polymeric groups.

[0468] The aforementioned polymerizable groups can be cationic polymerizable groups or free radical polymerizable groups, but from a reactivity point of view, free radical polymerizable groups are preferred.

[0469] As for the aforementioned polymerizable groups, there are no particular limitations as long as they are polymerizable groups. However, from the viewpoint of reactivity, olefinic unsaturated groups are preferred, more preferably vinylphenyl (styrene), (meth)acryloyloxy, or (meth)acrylamido, and especially (meth)acryloyloxy.

[0470] Furthermore, the polymer in the polymer particles having polymeric groups preferably has constituent units having polymeric groups.

[0471] Furthermore, polymeric groups can be introduced onto the surface of polymer particles through polymer reactions.

[0472] Furthermore, from the viewpoints of print durability, ink adhesion, UV plate abrasion suppression, on-machine developability, and suppression of development residue during on-machine development, the aforementioned polymer particles preferably comprise a resin having urea bonds, more preferably a resin having a structure obtained by reacting at least an isocyanate compound represented by the following formula (Iso) with water, and particularly preferably a resin having a structure obtained by reacting at least an isocyanate compound represented by the following formula (Iso) with water, and having a polyoxyethylene structure and a polyoxypropylene structure as a polyoxyethylene structure. Furthermore, particles comprising the aforementioned resin having urea bonds are preferably microgels.

[0473] [Chemical Formula 26]

[0474]

[0475] In the formula (Iso), n represents an integer from 0 to 10.

[0476] As an example of the reaction of an isocyanate compound represented by the above formula (Iso) with water, the reaction shown below can be cited. Additionally, the following example is an example where n=0 and the 4,4-isomer is used.

[0477] As shown below, if the isocyanate compound represented by the above formula (Iso) is reacted with water, a portion of the isocyanate groups in the water will hydrolyze to produce an amino group. The resulting amino group will then react with the isocyanate groups to form a urea bond, thus forming a dimer. Furthermore, by repeatedly performing the following reaction, a resin containing urea bonds is formed.

[0478] Furthermore, in the following reaction, by adding compounds such as alcohols and amines that are reactive with isocyanate groups (compounds with active hydrogen), it is also possible to introduce the structure of alcohols and amines into resins containing urea bonds.

[0479] As the compounds containing active hydrogen described above, the compounds described in the microgels described above are preferably examples.

[0480] [Chemical Formula 27]

[0481]

[0482] Furthermore, the resin having the above-mentioned urea bonds preferably has olefinic unsaturated groups, and more preferably has groups represented by the following formula (PETA).

[0483] [Chemical Formula 28]

[0484]

[0485] In the formula (PETA), the wavy line represents the bonding location with other structures.

[0486] The average particle size of the aforementioned particles is preferably 0.01 μm to 3.0 μm, more preferably 0.03 μm to 2.0 μm, and even more preferably 0.10 μm to 1.0 μm. Good resolution and long-term stability can be obtained within this range.

[0487] The average primary particle size of the particles described above in this invention is determined by light scattering or by taking electron micrographs of the particles. The particle size of a total of 5,000 particles is measured on the micrographs, and the average value is calculated. Furthermore, for non-spherical particles, the particle size of spherical particles having the same particle area as the particle area in the micrograph is taken as the particle size.

[0488] Furthermore, unless otherwise specified, the average particle size in this invention refers to the volume average particle size.

[0489] The aforementioned image recording layer may contain only one type of particle, particularly polymer particles, or it may contain two or more types.

[0490] Furthermore, from the viewpoints of developability, UV printing durability, and UV plate wear inhibition, the content of particles, especially polymer particles, in the image recording layer is preferably 5% to 90% by mass, more preferably 10% to 90% by mass, even more preferably 20% to 90% by mass, and especially preferably 50% to 90% by mass, relative to the total mass of the image recording layer.

[0491] Furthermore, from the viewpoints of developability, UV printing durability, and UV plate wear inhibition, the content of polymer particles in the image recording layer is preferably 20% to 100% by mass, more preferably 35% to 100% by mass, even more preferably 50% to 100% by mass, and particularly preferably 80% to 100% by mass, relative to the total mass of the components with a molecular weight of 3,000 or more in the image recording layer.

[0492] -Adhesive Polymer-

[0493] The aforementioned image recording layer may contain adhesive polymers other than polymer A, but from the viewpoints of machine developability, UV printing durability, and UV plate wear inhibition, it is preferable not to include them.

[0494] The aforementioned adhesive polymer is a polymer other than the aforementioned polymer particles, that is, an adhesive polymer that is not in particle shape.

[0495] As the above-mentioned adhesive polymer, (meth)acrylic resin, polyvinyl acetal resin or polyurethane resin are preferred.

[0496] The adhesive polymer described above can preferably be a known adhesive polymer used in the image recording layer of a lithographic printing plate master. As an example, a detailed description will be given of the adhesive polymer used in an in-machine developing type lithographic printing plate master (hereinafter also referred to as an in-machine developing adhesive polymer).

[0497] As an adhesive polymer for in-machine development, an adhesive polymer having an epoxy chain is preferred. The adhesive polymer having an epoxy chain may have a poly(epoxy) site in the main chain or in the side chains. Furthermore, it may be a graft polymer having poly(epoxy) in the side chains, or a block copolymer consisting of a block copolymer composed of repeating units containing poly(epoxy) and a block copolymer composed of repeating units not containing (epoxy).

[0498] When the main chain has a poly(epoxy) site, polyurethane resin is preferred. Examples of polymers whose main chain has a poly(epoxy) site in the side chain include (meth)acrylic resin, polyvinyl acetal resin, polyurethane resin, polyurea resin, polyimide resin, polyamide resin, epoxy resin, polystyrene resin, phenolic varnish-type phenolic resin, polyester resin, synthetic rubber, and natural rubber, with (meth)acrylic resin being particularly preferred.

[0499] Furthermore, as another preferred example of an adhesive polymer, a polymeric compound having a core of a polyfunctional thiol with six or more functions and less than ten functions, and having a polymer chain bonded to the core via thioether bonds, and the polymer chain having polymerizable groups (hereinafter also referred to as a star polymeric compound). As a star polymeric compound, for example, the compound described in Japanese Patent Application Publication No. 2012-148555 is preferred.

[0500] Regarding star-shaped polymer compounds, examples include compounds that have polymerizable groups such as olefinic unsaturated bonds, as described in Japanese Patent Application Publication No. 2008-195018, on the main chain or side chain, preferably the side chain, for improving the film strength of the imaging section. These polymerizable groups form crosslinks between polymer molecules, promoting curing.

[0501] As polymerizable groups, olefinic unsaturated groups such as (meth)acrylate, vinyl, allyl, and styrene, as well as epoxy groups, are preferred. From the viewpoint of polymerization reactivity, (meth)acrylate, vinyl, and styrene groups are more preferred, and (meth)acrylate is particularly preferred. These groups can be introduced into the polymer through polymer reactions and copolymerization. For example, the reaction of a polymer with a carboxyl group on its side chain with glycidyl methacrylate, or the reaction of a polymer with an epoxy group with a carboxylic acid containing an olefinic unsaturated group such as methacrylic acid, can be utilized. These groups can be used simultaneously.

[0502] Regarding the molecular weight of the adhesive 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 even more preferably 10,000 to 300,000.

[0503] Depending on the requirements, hydrophilic polymers such as polyacrylic acid and polyvinyl alcohol described in Japanese Patent Application Publication No. 2008-195018 can be used simultaneously. Furthermore, both lipophilic and hydrophilic polymers can be used simultaneously.

[0504] From the viewpoint of machine developability, the image recording layer preferably comprises polyvinyl acetal. Examples of polyvinyl acetal include, for instance, polyvinyl butyral.

[0505] Polyvinyl alcohol acetal is a resin obtained by acetalizing the hydroxyl groups of polyvinyl alcohol with aldehydes.

[0506] In particular, polyvinyl butyral obtained by acetalizing the hydroxyl groups of polyvinyl alcohol with butyraldehyde (i.e., butyraldehyde) is preferred.

[0507] Polyvinyl acetal preferably comprises the constituent unit represented by (a) below by acetalizing the hydroxyl groups of polyvinyl alcohol with aldehyde.

[0508] [Chemical Formula 29]

[0509]

[0510] Here, R represents the aldehyde residue used for acetalization.

[0511] In addition to hydrogen atoms and alkyl groups, R can also be an olefinic unsaturated group, which will be discussed later.

[0512] The content of the constituent unit represented by (a) above (also referred to as the amount of ethylidene in the main chain contained in the constituent unit represented by (a) above, and also referred to as the degree of acetalization) is preferably 50 mol% to 90 mol%, more preferably 55 mol% to 85 mol%, and even more preferably 55 mol% to 80 mol% relative to all constituent units (total amount of ethylidene in the main chain) of polyvinyl acetal.

[0513] In addition, the degree of acetalization refers to the mole fraction expressed as a percentage, obtained by dividing the amount of ethylene bonded to the acetal group (the amount of ethylene in the main chain contained in the constituent unit represented by (a) above) by the total amount of ethylene in the main chain.

[0514] Furthermore, the content of each constituent unit in polyvinyl acetal described later is also the same.

[0515] From the perspective of improving printability, polyvinyl acetal preferably has olefinic unsaturated groups.

[0516] Here, there is no particular limitation on the olefinic unsaturated group present in polyvinyl acetal. From the viewpoints of reactivity, machine developability and printing durability, it is preferred to select at least one group selected from the group consisting of vinylphenyl (styrene), vinyl ester, vinyl ether, allyl, (meth)acryloyloxy and (meth)acrylamide, more preferably vinyl, allyl, (meth)acryloyloxy, etc.

[0517] From the viewpoint of improving print durability, polyvinyl acetal preferably contains constituent units having olefinic unsaturated groups.

[0518] As a constituent unit having an olefinic unsaturated group, it can be a constituent unit having the aforementioned acetal ring, or it can be a constituent unit other than a constituent unit having an acetal ring.

[0519] From the viewpoint of increasing crosslinking density during exposure, polyvinyl acetal is preferably a compound in which an olefinic unsaturated group is introduced into the acetal ring. That is, in the constituent unit represented by (a) above, R preferably has an olefinic unsaturated group.

[0520] When the constituent unit having an olefinic unsaturated group is a constituent unit other than a constituent unit having an acetal ring, for example, it may be a constituent unit having an acrylate group, specifically, it may be a constituent unit represented by (d) below.

[0521] [Chemical Formula 30]

[0522]

[0523] When the constituent unit having an olefinic unsaturated group is a constituent unit other than the constituent unit having an acetal ring, the content of such constituent unit (also referred to as the acrylate content) is preferably 1 mol% to 15 mol% relative to all constituent units of polyvinyl acetal, more preferably 1 mol% to 10 mol%.

[0524] From the viewpoint of machine developability, polyvinyl acetal preferably contains a constituent unit having a hydroxyl group. That is, the polyvinyl acetal preferably contains a constituent unit derived from vinyl alcohol.

[0525] As a constituent unit having a hydroxyl group, the constituent unit represented by (b) below can be cited.

[0526] [Chemical Formula 31]

[0527]

[0528] As for the content of the constituent unit represented by (b) above (also referred to as the amount of hydroxyl radicals), from the viewpoint of machine developability, it is preferably 5 mol% to 50 mol% relative to all constituent units of polyvinyl acetal, more preferably 10 mol% to 40 mol%, and even more preferably 20 mol% to 40 mol%.

[0529] As described above, polyvinyl acetal may also contain other constituent units.

[0530] Other constituent units, for example, include constituent units having an acetyl group, and more specifically, constituent units represented by (c) below.

[0531] [Chemical Formula 32]

[0532]

[0533] The content of the constituent unit represented by (c) above (also referred to as the acetyl content) is preferably 0.5 mol% to 10 mol% relative to all constituent units of polyvinyl acetal, more preferably 0.5 mol% to 8 mol%, and even more preferably 1 mol% to 3 mol%.

[0534] Here, the degree of acetalization, the amount of acrylate groups, the amount of hydroxyl groups, and the amount of acetyl groups can be determined in the following manner.

[0535] That is, through 1 The molar content was calculated by ¹H NMR determination based on the proton peak area ratio of the methyl or methylene site of the acetal, the methyl site of the acrylate group, and the methyl site of the hydroxyl and acetyl groups.

[0536] The weight-average molecular weight of the above-mentioned polyvinyl acetal is preferably 18,000 to 150,000.

[0537] The solubility parameter (also known as the SP value) of the above-mentioned polyvinyl acetal is preferably 17.5 MPa. 1 / 2 ~20.0MPa 1 / 2 More preferably 18.0 MPa 1 / 2 ~19.5MPa 1 / 2 .

[0538] Here, the "solubility parameter (unit: (MPa)" in this invention is... 1 / 2 The solubility parameter is Hansen.

[0539] Regarding the Hansen solubility parameters, the solubility parameters imported by Hildebrand are divided into three components: dispersion term δd, polarity term δp, and hydrogen bonding term δh, and are shown in three-dimensional space. However, in this invention, δ (unit: (MPa)) is used instead. 1 / 2 ) represents the solubility parameter (hereinafter also referred to as the SP value), and is calculated using the following formula.

[0540] δ (MPa) 1 / 2 =(δd 2 +δp 2 +δh 2 ) 1 / 2

[0541] Furthermore, Hansen or his successors derived numerous values ​​for the dispersion term δd, polarity term δp, and hydrogen bonding term δh, which are detailed in the Polymer Handbook (fourth edition), VII-698–711. Detailed information on Hansen's solubility parameters is also documented in Charles M. Hansen's work, "Hansen Solubility Parameters; A Users Handbook" (CRC Press, 2007).

[0542] In this invention, the Hansen solubility parameter for a portion of the compound's structure can also be obtained by using the computer software "Hansen Solubility Parameters in Practice (HSPiPver.4.1.07)" with values ​​calculated based on its chemical structure.

[0543] Furthermore, in this invention, when the compound is an addition-polymer type, condensation-polymer type, or other polymer, the total amount is represented by multiplying the SP value of each monomer unit by the mole fraction; when the compound is a low-molecular-weight compound without monomer units, the SP value is taken as the total SP value of the compound.

[0544] In addition, in this invention, the SP value of the polymer can be calculated based on the polymer's molecular structure using the Hoy method described in the Polymer Handbook (fourth edition).

[0545] The following are specific examples of the above-mentioned polyvinyl acetal [P-1 to P-3], but the polyvinyl acetal used in this invention is not limited to these.

[0546] In the following structures, "l" is 50 mol% to 90 mol%, "m" is 0.5 mol% to 10 mol%, "n" is 5 mol% to 50 mol%, and "o" is 1 mol% to 15 mol.

[0547] [Chemical Formula 33]

[0548]

[0549] As the aforementioned polyvinyl acetal, commercially available products can be used.

[0550] Commercially available polyvinyl acetals include SEKISUI CHEMICAL CO., LTD.’s S-LEC series (specifically, S-LEC BX-L, BX-1, BX-5, BL-7Z, BM-1, BM-5, BH-6, BH-3, etc.).

[0551] The image recording layer of the present invention preferably contains a resin having fluorine atoms, more preferably contains a copolymer containing fluorinated hydrocarbon groups, and especially preferably contains a copolymer containing fluorinated aliphatic hydrocarbon groups.

[0552] By using resins containing fluorine atoms, especially copolymers containing fluorinated hydrocarbon groups, it is possible to suppress surface quality abnormalities caused by bubbling during the formation of the image recording layer, improve the coating surface, and enhance the ink adhesion of the formed image recording layer.

[0553] Furthermore, the image recording layer containing copolymers with fluorocarbon groups has a higher gray level, for example, it has high sensitivity to laser beams, and can obtain lithographic printing plates with good gray fog properties caused by scattered light, reflected light, etc., and excellent printing durability.

[0554] The copolymer containing fluorocarbon groups preferably has a constituent unit formed by a compound represented by any one of the following formulas (F1) to (F3), and more preferably has a constituent unit formed by a compound represented by the following formula (F2) or (F3).

[0555] [Chemical Formula 34]

[0556]

[0557] In equations (F1) to (F3), R F1 Each can be used independently to represent a hydrogen atom or a methyl group, L F Cf represents a single-bonded or divalent linking group, where some or all of the hydrogen atoms in the hydrocarbon group are replaced by fluorine atoms, and it is a straight-chain or branched hydrocarbon group with 1 to 10 carbon atoms. F2 X represents a hydrogen atom or a fluorine atom. F Each can be used independently to represent an oxygen atom, a sulfur atom, or -N (R). F3 )-, w1~w3 independently represent integers from 0 to 9, w4 represents integers from 1 to 10, w5 represents integers from 0 to 2, R F3 It represents an alkyl group having 1 to 4 hydrogen atoms or carbon atoms.

[0558] L in equation (F1) F Preferably, it is a single bond, an alkylene group having 1 to 20 carbon atoms, or a divalent arylene group having 6 to 20 carbon atoms; more preferably, it is a single bond or a divalent arylene group having 6 to 20 carbon atoms; and especially preferably, it is a single bond.

[0559] In formula (F1), Cf is preferably an aromatic hydrocarbon group with 6 to 10 carbon atoms in which part or all of the hydrogen atoms of the aromatic hydrocarbon group are replaced by fluorine atoms, more preferably a phenyl group in which part or all of the hydrogen atoms are replaced by fluorine atoms, and especially preferably a perfluorophenyl group.

[0560] X in equations (F2) and (F3) F Each is preferably an oxygen atom or -N(R) independently. F3 )-, more preferably oxygen atom.

[0561] R in equation (F2) F2 The preferred atom is fluorine.

[0562] In formula (F2), w1 is preferably an integer from 0 to 2, more preferably 1 or 2, and especially preferably 2.

[0563] In formula (F2), w2 is preferably an integer from 0 to 4, and more preferably 0.

[0564] In formula (F2), w3 is preferably 0 or 1, more preferably 0.

[0565] In formula (F2), w4 is preferably an integer from 2 to 10, more preferably an integer from 4 to 8, and especially preferably an integer from 4 to 6.

[0566] In formula (F3), w5 is preferably 0 or 1, more preferably 0.

[0567] R in equation (F3) F3 The preferred components are hydrogen atoms, methyl, ethyl, n-propyl, or n-butyl, with hydrogen atoms or methyl being more preferred.

[0568] The following are specific examples of monomers containing fluorine atoms used in resins containing fluorine atoms, but are not limited to these.

[0569] [Chemical Formula 35]

[0570]

[0571] [Chemical Formula 36]

[0572]

[0573] [Chemical Formula 37]

[0574]

[0575] [Chemical Formula 38]

[0576]

[0577] [Chemical Formula 39]

[0578]

[0579] [Chemical Formula 40]

[0580]

[0581] [Chemical Formula 41]

[0582]

[0583] [Chemical Formula 42]

[0584]

[0585] [Chemical Formula 43]

[0586]

[0587] From the viewpoint of machine developability, coating properties and machine developing residue suppression, the above-mentioned copolymer containing fluorocarbon groups preferably includes constituent units having a polyepoxide structure, more preferably including constituent units formed by compounds represented by any one of the above formulas (F1) and (F2), and constituent units having a polyepoxide structure.

[0588] The aforementioned copolymer containing fluorocarbon groups preferably has, in addition to the constituent units formed by compounds represented by any one of the above formulas (F1) and (F2), constituent units formed by at least one compound selected from the group consisting of poly(oxyalkylene) acrylates and poly(oxyalkylene) methacrylates.

[0589] The polyoxyalkylene groups in the above-mentioned poly(oxyalkylene) acrylates and poly(oxyalkylene) methacrylates can be converted from -(OR) F3 ) x - indicates that R F3 denoted as alkyl, x represents an integer greater than 2. As R F3 Preferably, it is a linear or branched alkylene group having 2 to 4 carbon atoms. As a linear or branched alkylene group having 2 to 4 carbon atoms, it is preferably -CH2CH2-, -CH2CH2CH2-, -CH(CH3)CH2-, or -CH(CH3)CH(CH3)-. x is preferably an integer from 2 to 100.

[0590] In the above polyoxyalkylene groups, x "OR" F3 "They can be the same or different. That is, the above polyoxyalkylene groups can be two or more 'OR' groups." F3"A group that is regularly or irregularly bonded. For example, the above-mentioned polyoxyalkylene group can be a group in which linear or branched oxypropylene units are regularly or irregularly bonded to oxyethylidene units. More specifically, the above-mentioned polyoxyalkylene group can be a group in which blocks of linear or branched oxypropylene units are bonded to blocks of oxyethylidene units."

[0591] Additionally, the polyoxyalkylene group may contain one or more linking groups (e.g., -CONH-Ph-NHCO-, -S-, etc., where Ph represents phenylene).

[0592] The molecular weight of the above-mentioned polyoxyalkylene group is preferably 250 to 3,000.

[0593] As the aforementioned poly(oxyalkylene) acrylates and poly(oxyalkylene) methacrylates, commercially available products or synthetic products may be used.

[0594] The aforementioned poly(oxyalkylene) acrylates and poly(oxyalkylene) methacrylates can be synthesized, for example, by reacting hydroxyl poly(oxyalkylene) compounds with acrylic acid, methacrylic acid, acryloyl chloride, methacryloyl chloride, acrylic anhydride, etc., using known methods.

[0595] As the aforementioned hydroxyl poly(oxyalkylene) compounds, commercially available products can be used, such as Adeka (registered trademark) Pluronic manufactured by ADEKA CORPORATION, Adeka Polyether manufactured by ADEKA CORPORATION, Carbowax (registered trademark) manufactured by Union Carbide Corporation, Triton manufactured by The Dow Chemical Company, PEG manufactured by DKS Co. Ltd., etc.

[0596] In addition, as poly(oxyalkylene)acrylates and poly(oxyalkylene)methacrylates, poly(oxyalkylene)diacrylates synthesized by known methods can be used.

[0597] In the image recording layer used in this invention, one adhesive polymer may be used alone, or two or more may be used simultaneously.

[0598] The aforementioned adhesive polymer can be included in the image recording layer in any amount. However, from the viewpoints of machine developability, UV printing durability, and UV plate wear inhibition, the image recording layer preferably does not contain the aforementioned adhesive polymer or the content of the aforementioned adhesive polymer is more than 0% by mass and less than 20% by mass relative to the total mass of the image recording layer. More preferably, it does not contain the aforementioned adhesive polymer or the content of the aforementioned adhesive polymer is more than 0% by mass and less than 10% by mass relative to the total mass of the image recording layer. Even more preferably, it does not contain the aforementioned adhesive polymer or the content of the aforementioned adhesive polymer is more than 0% by mass and less than 5% by mass relative to the total mass of the image recording layer. Particularly preferably, it does not contain the aforementioned adhesive polymer or the content of the aforementioned adhesive polymer is more than 0% by mass and less than 2% by mass relative to the total mass of the image recording layer. Most preferably, it does not contain the aforementioned adhesive polymer.

[0599] -Color developer-

[0600] The image recording layer described above preferably contains a color developer, more preferably an acid color developer. Furthermore, as a color developer, it is preferable to contain a colorless compound.

[0601] The term "color developer" used in this invention refers to a compound that exhibits the property of developing or decolorizing upon stimulation by light, acid, or the like, and that changes the color of the image recording layer. Furthermore, "acid color developer" refers to a compound that exhibits the property of developing or decolorizing upon heating in a state where it has received protons from an electron-accepting compound (e.g., an acid). As an acid color developer, a partial skeleton such as lactone, lactam, sulopentalide, spiropyran, ester, or amide is particularly preferred; these partial skeletons are preferably colorless compounds that rapidly undergo ring-opening or cleave upon contact with an electron-accepting compound.

[0602] Examples of such acid-based colorimetric agents include 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide (called "crystal violet lactone"), 3,3-bis(4-dimethylaminophenyl)phthalide, 3-(4-dimethylaminophenyl)-3-(4-diethylamino-2-tolyl)-6-dimethylaminophthalide, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylindole-3-yl)phthalide, and 3-(4-dimethylaminophenyl)-3-(2-methylindole-3-yl)phthalide. 3,3-Bis(1,2-dimethylindol-3-yl)-5-dimethylaminophthalide, 3,3-Bis(1,2-dimethylindol-3-yl)-6-dimethylaminophthalide, 3,3-Bis(9-ethylcarbazole-3-yl)-6-dimethylaminophthalide, 3,3-Bis(2-phenylindol-3-yl)-6-dimethylaminophthalide, 3-(4-dimethylaminophenyl)-3-(1-methylpyrrole-3-yl)-6-dimethylaminophthalide,

[0603] 3,3-bis[1,1-bis(4-dimethylaminophenyl)vinyl-2-yl]-4,5,6,7-tetrachlorophthalide, 3,3-bis[1,1-bis(4-pyrrolidinephenyl)vinyl-2-yl]-4,5,6,7-tetrabromophthalide, 3,3-bis[1-(4-dimethylaminophenyl)-1-(4-methoxyphenyl)vinyl-2-yl]-4,5,6,7-tetrachlorophthalide, 3,3-bis[1-(4-pyrrolidinephenyl)-1-(4-methoxyphenyl)vinyl-2-yl]-4,5,6,7-tetrachlorophthalide, 3-[1,1-bis(1-ethyl) Phthalate derivatives include: 3-[1,1-di(1-ethyl-2-methylindole-3-yl)vinyl-2-yl]-3-(4-diethylaminophenyl)phthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindole-3-yl)phthalide, 3,3-bis(1-n-octyl-2-methylindole-3-yl)phthalide, and 3-(2-methyl-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindole-3-yl)phthalide, etc.

[0604] 4,4-Bis-dimethylaminobenzopropanol benzyl ether, N-halophenyl-leuco-auramine, N-2,4,5-trichlorophenyl-leuco-auramine, Rhodamine-B-phenylaminolactam, Rhodamine-(4-nitrophenylamino)lactam, Rhodamine-B-(4-chlorophenylamino)lactam, 3,7-bis(diethylamino)-10-benzoylpyrazine, benzoyl colorless methylene blue, 4-nitrobenzoylmethylene blue,

[0605] 3,6-Dimethoxyfluorane, 3-Dimethylamino-7-methoxyfluorane, 3-Diethylamino-6-methoxyfluorane, 3-Diethylamino-7-methoxyfluorane, 3-Diethylamino-7-chlorofluorane, 3-Diethylamino-6-methyl-7-chlorofluorane, 3-Diethylamino-6,7-dimethylfluorane, 3-N-hexyl-N-n-butylamino-7-methylfluorane, 3-Diethylamino-7-dibenzylaminofluorane, 3-Diethylamino-7-octylaminofluorane, 3-Diethylamino-7-di-n-hexylaminofluorane, 3-Diethylamino-7-phenylaminofluorane, 3-di Ethylamino-7-(2'-fluorophenylamino)fluorane, 3-diethylamino-7-(2'-chlorophenylamino)fluorane, 3-diethylamino-7-(3'-chlorophenylamino)fluorane, 3-diethylamino-7-(2',3'-dichlorophenylamino)fluorane, 3-diethylamino-7-(3'-trifluoromethylphenylamino)fluorane, 3-di-n-butylamino-7-(2'-fluorophenylamino)fluorane, 3-di-n-butylamino-7-(2'-chlorophenylamino)fluorane, 3-N-isopentyl-N-ethylamino-7-(2'-chlorophenylamino)fluorane,

[0606] 3-N-hexyl-N-ethylamino-7-(2'-chlorophenylamino)fluorane, 3-diethylamino-6-chloro-7-phenylaminofluorane, 3-di-n-butylamino-6-chloro-7-phenylaminofluorane, 3-diethylamino-6-methoxy-7-phenylaminofluorane, 3-di-n-butylamino-6-ethoxy-7-phenylaminofluorane, 3-pyrrolidine-6-methyl-7-phenylaminofluorane, 3-hydropyridyl-6-methyl-7-phenylaminofluorane, 3-morpholinyl- 6-Methyl-7-phenylaminofluorane, 3-dimethylamino-6-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-phenylaminofluorane, 3-di-n-butylamino-6-methyl-7-phenylaminofluorane, 3-di-n-pentanamino-6-methyl-7-phenylaminofluorane, 3-N-ethyl-N-methylamino-6-methyl-7-phenylaminofluorane, 3-N-n-propyl-N-methylamino-6-methyl-7-phenylaminofluorane, 3-N-n-propyl-N- Ethylamino-6-methyl-7-phenylaminofluorane, 3-N-n-butyl-N-methylamino-6-methyl-7-phenylaminofluorane, 3-N-n-butyl-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-N-isobutyl-N-methylamino-6-methyl-7-phenylaminofluorane, 3-N-isobutyl-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-N-isopentyl-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-N-n-hexyl 3-N-Cyclohexyl-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-N-Cyclohexyl-N-n-propylamino-6-methyl-7-phenylaminofluorane, 3-N-Cyclohexyl-N-n-butyl-6-methyl-7-phenylaminofluorane, 3-N-Cyclohexyl-N-n-hexylamino-6-methyl-7-phenylaminofluorane, 3-N-Cyclohexyl-N-n-octylamino-6-methyl-7-phenylaminofluorane,

[0607] 3-N-(2'-methoxyethyl)-N-methylamino-6-methyl-7-phenylaminofluorane, 3-N-(2'-methoxyethyl)-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-N-(2'-methoxyethyl)-N-isobutylamino-6-methyl-7-phenylaminofluorane, 3-N-(2'-ethoxyethyl)-N-methylamino-6-methyl-7-phenylaminofluorane, 3-N-(2'-ethoxyethyl)-N-ethylamino 3-N-(3'-methoxypropyl)-N-methylamino-6-methyl-7-phenylaminofluorane, 3-N-(3'-methoxypropyl)-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-N-(3'-ethoxypropyl)-N-methylamino-6-methyl-7-phenylaminofluorane, 3-N-(3'-ethoxypropyl)-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-N-( 2'-Tetrahydrofurfuryl)-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-N-(4'-tolyl)-N-ethylamino-6-methyl-7-phenylaminofluorane, 3-diethylamino-6-ethyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-(3'-tolylamino)fluorane, 3-diethylamino-6-methyl-7-(2',6'-ditolylamino)fluorane, 3-di-n-butylamino-6-methyl-7 Fluoranes such as -(2',6'-dimethylamino)fluorane, 3-di-n-butylamino-7-(2',6'-dimethylamino)fluorane, 2,2-bis[4'-(3-N-cyclohexyl-N-methylamino-6-methylfluorane)-7-ylaminophenyl]propane, 3-[4'-(4-phenylaminophenyl)aminophenyl]amino-6-methyl-7-chlorofluorane, 3-[4'-(dimethylaminophenyl)]amino-5,7-dimethylfluorane, etc.

[0608] 3-(2-methyl-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-n-propoxycarbonylamino-4-di-n-propanaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-methylamino-4-di-n-propanaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-methyl-4-di-n-hexaneaminophenyl)-3-(1-n-octyl-2- 3,3-Bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3,3-bis(1-n-octyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-octyl-2-methylindole-3-yl)-4 or 7-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4 or 7-azaphthalide, 3-(2-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4 or 7-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-phenylindole-3-yl)-4 or 7-azaphthalide, 3-(2-butoxy-4-diethylaminophenyl)-3-(1-ethyl-2-phenyl) Phthalate derivatives including 3-yl)-4 or 7-azaphthalimide, 3-methyl-spiro-dinaphthopiperan, 3-ethyl-spiro-dinaphthopiperan, 3-phenyl-spiro-dinaphthopiperan, 3-benzyl-spiro-dinaphthopiperan, 3-methyl-naphtho-(3-methoxybenzo)spiropyperan, 3-propyl-spiro-dibenzopiperan-3,6-bis(dimethylamino)fluorene-9-spiro-3'-(6'-dimethylamino)phthalide, and 3,6-bis(diethylamino)fluorene-9-spiro-3'-(6'-dimethylamino)phthalide.

[0609] In addition, there are 2'-phenylamino-6'-(N-ethyl-N-isopentyl)amino-3'-methylspiro[isobenzofuran-1(3H),9'-(9H)xanthon]-3-one, 2'-phenylamino-6'-(N-ethyl-N-(4-tolyl))amino-3'-methylspiro[isobenzofuran-1(3H),9'-(9H)xanthon]-3-one, 3'-N,N-dibenzylamino-6'-N,N-diethylaminospiro[isobenzofuran-1(3H),9'-(9H)xanthon]-3-one, 2'-(N-methyl-N-phenyl)amino-6'-(N-ethyl-N-(4-tolyl))aminospiro[isobenzofuran-1(3H),9'-(9H)xanthon]-3-one, etc.

[0610] From the viewpoint of color development, the color developer used in this invention is preferably selected from at least one compound selected from the group consisting of spiropyran compounds, spiroxazine compounds, spironolactone compounds, and spironolactam compounds.

[0611] From the perspective of visibility, the preferred hue of the pigment after color development is green, blue, or black.

[0612] Furthermore, from the viewpoint of color development and visual recognizability of the exposed part, the aforementioned acid color developer is preferably a colorless pigment.

[0613] As for the aforementioned colorless pigment, there are no particular restrictions as long as it has a colorless structure, but it is preferred to have a spiro structure, and more preferably to have a spironolactone ring structure.

[0614] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the colorless pigment described above is preferably a colorless pigment having a phthaloyl structure or a fluorescent yellow matrix structure.

[0615] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the aforementioned colorless pigment having a phthaloyl structure or a fluorescent yellow matrix 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).

[0616] [Chemical Formula 44]

[0617]

[0618] In formulas (Le-1) to (Le-3), ERG independently represents an electron-donating group, X1 to X4 independently represent a hydrogen atom, a halogen atom, or a dialkylphenylamino atom, and X5 to X 10 Each of the following groups independently represents a hydrogen atom, a halogen atom, or a monovalent organic group. Y1 and Y2 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 independently represent a hydrogen atom, an alkyl group, or an aryl group.

[0619] From the viewpoint of color development and visual recognizability of the exposed portion, the electron-donating group in the ERG of formulas (Le-1) to (Le-3) is preferably amino, alkylamino, arylamino, dialkylamino, monoalkylmonoarylamino, diarylamino, alkoxy, aryloxy, or alkyl. More preferably, it is amino, alkylamino, arylamino, dialkylamino, monoalkylmonoarylamino, diarylamino, alkoxy, or aryloxy. Even more preferably, it is arylamino, monoalkylmonoarylamino, or diarylamino. Particularly preferred are arylamino or monoalkylmonoarylamino.

[0620] From the viewpoint of color development and visual recognizability of the exposed part, X1 to X4 in formulas (Le-1) to (Le-3) are each preferably hydrogen atoms or chlorine atoms, and more preferably hydrogen atoms.

[0621] From the perspective of color development and the visual recognizability of the exposed part, X5 to X in formula (Le-2) or formula (Le-3) 10 Each atom is preferably a hydrogen atom, halogen atom, alkyl, aryl, amino, alkylamino, arylamino, dialkylamino, monoalkylmonarylamino, diarylamino, hydroxyl, alkoxy, aryloxy, acyl, alkoxycarbonyl, aryloxycarbonyl or cyano, more preferably a hydrogen atom, halogen atom, alkyl, aryl, alkoxy or aryloxy, even more preferably a hydrogen atom, halogen atom, alkyl or aryl, and especially preferably a hydrogen atom.

[0622] From the viewpoint of color development and visual recognizability of the exposed part, Y1 and Y2 in formulas (Le-1) to (Le-3) are preferably at least one of them as C, and more preferably both Y1 and Y2 are C.

[0623] From the viewpoint of color development and visual recognizability of the exposed part, Ra1 in formulas (Le-1) to (Le-3) is preferably alkyl or alkoxy, more preferably alkoxy, and especially preferably methoxy.

[0624] From the viewpoint of color development and visual recognizability of the exposed part, Rb1 to Rb4 in formulas (Le-1) to (Le-3) are each preferably hydrogen atoms or alkyl groups, more preferably alkyl groups, and especially preferably methyl groups.

[0625] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the aforementioned colorless pigment having a phthaloyl structure or a fluorescent yellow matrix structure is more preferably a compound represented by any one of the following formulas (Le-4) to (Le-6), and even more preferably a compound represented by the following formula (Le-5).

[0626] [Chemical Formula 45]

[0627]

[0628] In formulas (Le-4) to (Le-6), ERG independently represents an electron-donating group, X1 to X4 independently represent a hydrogen atom, a halogen atom, or a dialkylphenylamino group, Y1 and Y2 independently represent C or N, X1 is absent when Y1 is N, X4 is absent when Y2 is N, Ra1 represents a hydrogen atom, an alkyl group, or an alkoxy group, and Rb1 to Rb4 independently represent a hydrogen atom, an alkyl group, or an aryl group.

[0629] The ERG, X1 to X4, Y1, Y2, Ra1 and Rb1 to Rb4 in equations (Le-4) to (Le-6) have the same meaning as the ERG, X1 to X4, Y1, Y2, Ra1 and Rb1 to Rb4 in equations (Le-1) to (Le-3), and the preferred methods are also the same.

[0630] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the aforementioned colorless pigment having a phthaloyl structure or a fluorescent yellow matrix structure is further preferably a compound represented by any one of the following formulas (Le-7) to (Le-9), and is particularly preferably a compound represented by the following formula (Le-8).

[0631] [Chemical Formula 46]

[0632]

[0633] In formulas (Le-7) to (Le-9), X1 to X4 independently represent hydrogen atoms, halogen atoms, or dialkylphenylamino groups, Y1 and Y2 independently represent C or N, X1 is absent when Y1 is N, X4 is absent when Y2 is N, Ra1 to Ra4 independently represent hydrogen atoms, alkyl groups, or alkoxy groups, Rb1 to Rb4 independently represent hydrogen atoms, alkyl groups, or aryl groups, and Rc1 and Rc2 independently represent aryl groups.

[0634] The meanings of X1 to X4, Y1 and Y2 in equations (Le-7) to (Le-9) are the same as those of X1 to X4, Y1 and Y2 in equations (Le-1) to (Le-3), and the preferred methods are also the same.

[0635] From the viewpoint of color development and visual recognizability of the exposed part, Ra1 to Ra4 in formulas (Le-7) to (Le-9) are each preferably alkyl or alkoxy, more preferably alkoxy, and especially preferably methoxy.

[0636] From the viewpoint of color development and visual recognizability of the exposed part, Rb1 to Rb4 in formulas (Le-7) to (Le-9) are each preferably hydrogen atoms, alkyl groups, or aryl groups substituted with alkyl or alkoxy groups, more preferably hydrogen atoms or alkyl groups, and especially preferably hydrogen atoms or methyl groups.

[0637] From the viewpoint of color development and visual recognizability of the exposed part, Rc1 and Rc2 in formula (Le-8) are preferably phenyl or alkylphenyl, and more preferably phenyl.

[0638] Furthermore, in formula (Le-8), from the viewpoint of color development and visual recognizability of the exposed part, it is preferable that X1 to X4 are hydrogen atoms and Y1 and Y2 are C atoms.

[0639] Furthermore, in formula (Le-8), from the viewpoint of color development and visual recognizability of the exposed portion, Rb1 and Rb2 are each preferably hydrogen atoms, alkyl groups, or aryl groups substituted with alkyl or alkoxy groups, and more preferably hydrogen atoms or alkyl groups.

[0640] The alkyl groups in formulas (Le-1) to (Le-9) can be straight chains, branched chains, or ring structures.

[0641] Furthermore, 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, even more preferably 1 to 4, and especially preferably 1 or 2.

[0642] The number of carbon atoms in the aryl group in formulas (Le-1) to (Le-9) is preferably 6 to 20, more preferably 6 to 10, and especially preferably 6 to 8.

[0643] Furthermore, the monovalent organic groups, alkyl groups, aryl groups, dialkylphenylamino groups, alkylamino groups, alkoxy groups, etc., in formulas (Le-1) to (Le-9) can have substituents. Examples of substituents include alkyl groups, aryl groups, halogen atoms, amino groups, alkylamino groups, arylamino groups, dialkylamino groups, monoalkylmonoarylamino groups, diarylamino groups, hydroxyl groups, alkoxy groups, aryloxy groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, and cyano groups. Moreover, these substituents can be further replaced by other substituents.

[0644] The following compounds are examples of colorless pigments having a phthalide structure or a fluorescein parent structure that are preferred for use. Additionally, Me represents a methyl group.

[0645] [Chemical Formula 47]

[0646]

[0647] [Chemical Formula 48]

[0648]

[0649] [Chemical Formula 49]

[0650]

[0651] [Chemical Formula 50]

[0652]

[0653] [Chemical Formula 51]

[0654]

[0655] Alternatively, commercially available products can be used as acid colorimetric reagents, such as ETAC, RED500, RED520, CVL, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, BLUE220, H-3035, BLUE203, ATP, H-1046, H-2114 (all manufactured by Fukui Yamada Chemical Co., Ltd.), ORANGE-DCF, Vermilion-DCF, PINK-DCF, RED-DCF, BLMB, CVL, GREEN-DCF, and TH-107 (all manufactured by HODOGAYA CHEMICAL). ODB, ODB-2, ODB-4, ODB-250, ODB-BlackXV, Blue-63, Blue-502, GN-169, GN-2, Green-118, Red-40, Red-8 (all manufactured by YAMAMOTO CHEMICALS INC.), and crystal violet lactone (manufactured by Tokyo Chemical Industry Co., Ltd.) are among the commercially available products. Among these, films formed from 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 exhibit good visible light absorption and are therefore preferred.

[0656] Furthermore, the following compounds are examples of colorless pigments that are preferred for use.

[0657] [Chemical Formula 52]

[0658]

[0659] These color developers can be used alone or in combination with two or more components.

[0660] The content of the developer is preferably 0.5% to 10% by mass relative to the total mass of the image recording layer, more preferably 1% to 5% by mass.

[0661] -Chain transfer agent-

[0662] The image recording layer used in this invention may contain a chain transfer agent. Chain transfer agents help improve print durability in lithographic printing plates.

[0663] As a chain transfer agent, thiols are preferred, and from the viewpoint of boiling point (low volatility), thiols with 7 or more carbon atoms are more preferred, and compounds having a thiol group on the aromatic ring (aromatic thiols) are even more preferred. The aforementioned thiols are preferably monofunctional thiols.

[0664] Specifically, the following compounds can be cited as chain transfer agents.

[0665] [Chemical Formula 53]

[0666]

[0667] [Chemical Formula 54]

[0668]

[0669] [Chemical Formula 55]

[0670]

[0671] [Chemical Formula 56]

[0672]

[0673] Chain transfer agents can be added in one form or in two or more forms at the same time.

[0674] The content of the chain transfer agent relative to the total mass of the image recording layer is preferably 0.01% to 50% by mass, more preferably 0.05% to 40% by mass, and even more preferably 0.1% to 30% by mass.

[0675] -Low molecular weight hydrophilic compounds-

[0676] To suppress the decline in print durability and improve on-machine developability, the image recording layer may contain a low-molecular-weight hydrophilic compound. The low-molecular-weight hydrophilic compound is preferably a compound with a molecular weight of less than 1,000, more preferably a compound with a molecular weight of less than 800, and even more preferably a compound with a molecular weight of less than 500.

[0677] Examples of low-molecular-weight hydrophilic compounds, such as water-soluble organic compounds, include glycols and their ether or ester derivatives such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol; polyols such as glycerol, pentaerythritol, and tris(2-hydroxyethyl)isocyanurate; organic amines and their salts such as triethanolamine, diethanolamine, and monoethanolamine; organic sulfonic acids and their salts such as alkyl sulfonic acids, p-toluenesulfonic acid, and benzenesulfonic acid; organic aminosulfonic acids and their salts such as alkyl aminosulfonic acids; organic sulfuric acids and their salts such as alkyl sulfuric acid and alkyl ether sulfuric acid; organic phosphonic acids and their salts such as phenylphosphonic acid; organic carboxylic acids and their salts such as tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, and amino acids; and betaine.

[0678] As a low-molecular-weight hydrophilic compound, it preferably contains at least one selected from the group consisting of polyols, organic sulfates, organic sulfonates and betaines.

[0679] Specific examples of organic sulfonates include alkyl sulfonates such as sodium n-butylsulfonate, sodium n-hexylsulfonate, sodium 2-ethylhexylsulfonate, sodium cyclohexylsulfonate, and sodium n-octylsulfonate; and alkyl sulfonates containing ethylene oxide chains such as sodium 5,8,11-trioxapentadecane-1-sulfonate, sodium 5,8,11-trioxaheptadecane-1-sulfonate, sodium 13-ethyl-5,8,11-trioxaheptadecane-1-sulfonate, and sodium 5,8,11,14-tetraoxatetracosane-1-sulfonate. Acid salts; aryl sulfonates such as sodium benzenesulfonate, sodium p-toluenesulfonate, sodium p-hydroxybenzenesulfonate, sodium p-styrenesulfonate, sodium dimethyl isophthalate-5-sulfonate, sodium 1-naphthylsulfonate, sodium 4-hydroxynaphthylsulfonate, disodium 1,5-naphthalenedisulfonate, and trisodium 1,3,6-naphthalenetrisulfonate; and compounds described in paragraphs 0026 to 0031 of Japanese Patent Application Publication No. 2007-276454 and paragraphs 0020 to 0047 of Japanese Patent Application Publication No. 2009-154525. The salts can be potassium salts or lithium salts.

[0680] Examples of organosulfates include sulfates of alkyl, alkenyl, alkynyl, aryl, or heterocyclic monoethers of polyethylene oxide. The number of ethylene oxide units is preferably 1 to 4, and the salt is preferably a sodium, potassium, or lithium salt. Specific examples include compounds described in paragraphs 0034 to 0038 of Japanese Patent Application Publication No. 2007-276454.

[0681] As betaines, compounds with 1 to 5 carbon atoms in the hydrocarbon substituents targeting the nitrogen atom are preferred. Specific examples include trimethylammonium acetate, dimethylpropylammonium acetate, 3-hydroxy-4-trimethylammonium butyrate, 4-(1-pyridyl)butyrate, 1-hydroxyethyl-1-imidazolium acetate, trimethylammonium methanesulfonate, dimethylpropylammonium methanesulfonate, 3-trimethylammonium-1-propanesulfonate, and 3-(1-pyridyl)-1-propanesulfonate.

[0682] Low molecular weight hydrophilic compounds have small hydrophobic structures and almost no surface activity, so the dampening solution will not penetrate the exposure part (image part) of the image recording layer and reduce the hydrophobicity or film strength of the image part, thus maintaining the ink acceptability and printing durability of the image recording layer well.

[0683] The content of the low-molecular-weight hydrophilic compound relative to the total mass of the image recording layer is preferably 0.5% to 20% by mass, more preferably 1% to 15% by mass, and even more preferably 2% to 10% by mass. Good in-machine developability and printing durability can be obtained within this range.

[0684] Low molecular weight hydrophilic compounds can be used alone or in combination of two or more.

[0685] -Sensitizer-

[0686] To improve ink adhesion, the image recording layer may contain sensitizers such as phosphor compounds, nitrogen-containing low-molecular-weight compounds, and ammonium-containing polymers. In particular, when the protective layer contains inorganic layered compounds, these compounds act as surface covering agents for the inorganic layered compounds, suppressing the decrease in ink adhesion during printing caused by the inorganic layered compounds.

[0687] As a sensitizer, it is preferable to use phosphonium compounds, nitrogen-containing low molecular weight compounds and ammonium-containing polymers simultaneously, and more preferably to use phosphonium compounds, quaternary ammonium salts and ammonium-containing polymers simultaneously.

[0688] Examples of phosphonium compounds include those described in Japanese Patent Application Publication Nos. 2006-297907 and 2007-50660. Specific examples include tetrabutylphosphonium iodide, butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide, 1,4-bis(triphenylphosphine)butane di(hexafluorophosphate), 1,7-bis(triphenylphosphine)heptane sulfate, and 1,9-bis(triphenylphosphine)nonanenaphthalene-2,7-disulfonate.

[0689] Examples of nitrogen-containing low-molecular-weight compounds include amine salts and quaternary ammonium salts. Furthermore, examples include imidazoline onion salts, benzimidazolinium onion salts, pyridinium onion salts, and quinolinium onion salts. Quaternary ammonium salts and pyridinium onion salts are preferred. Specific examples include tetramethylammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate, dodecyltrimethylammonium p-toluenesulfonate, benzyltriethylammonium hexafluorophosphate, benzyldimethyloctylammonium hexafluorophosphate, benzyldimethyldodecylammonium hexafluorophosphate, and compounds described in paragraphs 0021 to 0037 of Japanese Patent Application Publication No. 2008-284858 and paragraphs 0030 to 0057 of Japanese Patent Application Publication No. 2009-90645.

[0690] As an ammonium-containing polymer, it is acceptable as long as it contains an ammonium group in its structure. Preferred polymers are those containing 5 mol% to 80 mol% of ammonium-containing (meth)acrylates as copolymer components in their side chains. As a specific example, the polymer described in paragraphs 0089 to 0105 of Japanese Patent Application Publication No. 2009-208458 can be cited.

[0691] Regarding ammonium-containing polymers, the specific viscosity (unit: ml / g) determined by the method described in Japanese Patent Application Publication No. 2009-208458 is preferably in the range of 5 to 120, more preferably in the range of 10 to 110, and particularly preferably in the range of 15 to 100. When the above specific viscosity is converted to weight-average molecular weight (Mw), it is preferably 10,000 to 150,0000, more preferably 17,000 to 140,000, and particularly preferably 20,000 to 130,000.

[0692] The following are specific examples of ammonium-containing polymers.

[0693] (1) 2-(trimethylammonium) ethyl methacrylate p-toluenesulfonate / 3,6-dioxamethacrylate heptyl copolymer (molar ratio 10 / 90, Mw 45,000)

[0694] (2) 2-(trimethylammonium) ethyl methacrylate = hexafluorophosphate / 3,6-dioxamethacrylate heptyl copolymer (molar ratio 20 / 80, Mw 60,000)

[0695] (3) 2-(ethyl dimethylammonium) ethyl methacrylate p-toluenesulfonate / hexyl methacrylate copolymer (molar ratio 30 / 70, Mw 45,000)

[0696] (4) 2-(trimethylammonium) ethyl methacrylate = hexafluorophosphate / 2-ethylhexyl methacrylate copolymer (molar ratio 20 / 80, Mw 60,000)

[0697] (5) 2-(trimethylammonium) ethyl methacrylate = methyl sulfate / hexyl methacrylate copolymer (molar ratio 40 / 60, Mw 70,000)

[0698] (6) 2-(Butyldimethylammonium) ethyl methacrylate = hexafluorophosphate / 3,6-dioxamethacrylate heptyl copolymer (molar ratio 25 / 75, Mw 65,000)

[0699] (7) Ethyl 2-(butyldimethylammonium) acrylate = hexafluorophosphate / 3,6-dioxamethacrylate heptyl copolymer (molar ratio 20 / 80, Mw 65,000)

[0700] (8) 2-(Butyldimethylammonium) ethyl methacrylate = 13-ethyl-5,8,11-trioxa-1-heptadecanesulfonate / 3,6-dioxamethacrylate heptyl copolymer (molar ratio 20 / 80, Mw 75,000)

[0701] (9) 2-(Butyldimethylammonium) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate / 2-hydroxy-3-methacryloyloxypropyl methacrylate copolymer (molar ratio is 15 / 80 / 5, Mw is 65,000)

[0702] Sensitizers can be used alone or in combination of two or more.

[0703] The content of the sensitizer relative to the total mass of the image recording layer is preferably 0.01% to 30.0% by mass, more preferably 0.1% to 15.0% by mass, and particularly preferably 1% to 10% by mass.

[0704] -Other ingredients-

[0705] The image recording layer may contain surfactants, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic particles, inorganic layered compounds, etc., as other components. Specifically, please refer to paragraphs 0114 to 0159 of Japanese Patent Application Publication No. 2008-284817.

[0706] -Formation of the image recording layer-

[0707] The image recording layer in the lithographic printing plate original disclosed herein can be formed, for example, by dispersing or dissolving the necessary components in a known solvent to prepare a coating liquid, as described in paragraphs 0142-0143 of Japanese Patent Application Publication No. 2008-195018, applying the coating liquid onto a support by a known method such as bar coating, and then drying it.

[0708] As a solvent, known solvents can be used. Specifically, examples include 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 solvent can be used alone or in combination with two or more solvents. The concentration of solid components in the coating solution is preferably about 1 to 50% by mass.

[0709] The coating amount (solid content) of the image recording layer after coating and drying varies depending on the application, but from the viewpoint of obtaining good sensitivity and good film properties of the image recording layer, 0.3 g / m² is preferred. 2 ~3.0g / m 2 .

[0710] <Aluminum Support>

[0711] The aluminum support in the lithographic printing plate original involved in this invention can be appropriately selected from known aluminum supports for lithographic printing plate originals. Hereinafter, the aluminum support will be simply referred to as the "support".

[0712] As an aluminum support, an aluminum support with a hydrophilic surface is preferred (hereinafter also referred to as "hydrophilic aluminum support").

[0713] From the viewpoint of scratch contamination suppression, the contact angle between the aluminum support and water on the surface of the image recording layer side of the aluminum support, based on the air droplet method, is preferably 110° or less, more preferably 90° or less, further preferably 80° or less, even more preferably 50° or less, especially preferably 30° or less, especially preferably 20° or less, and most preferably 10° or less in the case of the lithographic printing plate original involved in this invention.

[0714] In this invention, the contact angle with water on the surface of the image recording layer side of the aluminum support, based on the aerial water droplet method, is determined by the following method.

[0715] The original lithographic printing plate is immersed in a solvent capable of removing the image recording layer (e.g., the solvent used in the coating solution for the image recording layer), the image recording layer is scraped off with at least one of a sponge and a cotton cloth, and the image recording layer is dissolved in the solvent, thereby exposing the surface of the aluminum support.

[0716] The contact angle of water on the surface of the image recording layer side of the exposed aluminum support was measured using a fully automated contact angle meter (e.g., DM-501 manufactured by Kyowa Interface Science Co., Ltd.) as the contact angle of a water droplet on the surface at 25°C (after 0.2 seconds).

[0717] As the aluminum support in this invention, it is preferable to use an aluminum plate that has been roughened by a known method and then anodized. That is, the aluminum support in this invention preferably has an aluminum plate and an anodized aluminum film disposed on the aluminum plate.

[0718] The following shows an example of a preferred embodiment of the aluminum support used in this invention (the aluminum support involved in this example will also be referred to as "support (1)").

[0719] That is, the support (1) has an aluminum plate and an anodized aluminum film disposed on the aluminum plate, the anodized film being located closer to the image recording layer side than the aluminum plate, the anodized film having micropores extending from the surface of the image recording layer side along the depth direction, the average diameter of the micropores on the surface of the anodized film being greater than 10 nm and less than 100 nm, and the L of the surface of the anodized film on the image recording layer side... * a * b * Lightness (L) in the color system * The value is 70-100.

[0720] Figure 1 This is a schematic cross-sectional view of one embodiment of the aluminum support 12a.

[0721] The aluminum support 12a has a laminated structure consisting of an aluminum plate 18 and an anodized aluminum film 20a (hereinafter also simply referred to as "anodized film 20a") stacked sequentially. Furthermore, the anodized 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 anodized film, an image recording layer, and a water-soluble resin layer sequentially on the aluminum plate.

[0722] -Anodized film-

[0723] The preferred embodiment of the anodic oxide film 20a will be described below.

[0724] The anodized film 20a is a film formed on the surface of the aluminum plate 18 by anodizing, and the film has ultrafine micropores 22a that are approximately perpendicular to the film surface and uniformly distributed. The micropores 22a extend from the surface of the anodized film 20a on the image recording layer side (the surface of the anodized film 20a on the side opposite to the aluminum plate 18 side) along the thickness direction (aluminum plate 18 side).

[0725] The average diameter (average opening diameter) of the micropores 22a in the anodic oxide film 20a on the surface of the anodic oxide film is preferably greater than 10 nm and less than 100 nm. From the viewpoint of balancing printability, stain resistance, and image visual recognizability, 15 nm to 60 nm is more preferred, 20 nm to 50 nm is even more preferred, and 25 nm to 40 nm is particularly preferred. The diameter inside the pores can be wider or narrower than the surface layer.

[0726] If the average diameter exceeds 10 nm, the printing durability and image visual recognition are superior. Furthermore, if the average diameter is below 100 nm, the printing durability is even better.

[0727] Regarding the average diameter of the micropores 22a, the surface of the anodic oxide film 20a was observed using a field emission scanning electron microscope (FE-SEM) with a magnification of 150,000x in N=4 images. In the four images obtained, the diameters of 50 micropores existing in the range of 400nm×600nm were measured and calculated as the arithmetic mean.

[0728] In addition, when the shape of the micropore 22a is not circular, the equivalent diameter of the circle is used. The "equivalent diameter of the circle" refers to the diameter of a circle when the shape of the opening is assumed to be a circle with a projected area equal to the projected area of ​​the opening.

[0729] The depth of the micropore 22a is not particularly limited, but it is preferably 10 nm to 3,000 nm, more preferably 50 nm to 2,000 nm, and even more preferably 300 nm to 1,600 nm.

[0730] In addition, the above depth is the value obtained by taking a cross-sectional photograph (150,000x) of the anodized film 20a, measuring the depth of more than 25 micropores 22a, and averaging them.

[0731] The shape of the micropore 22a is not particularly limited, in Figure 1 The core is roughly straight tubular (roughly cylindrical), but it can also be conical, with the diameter decreasing towards the depth direction (thickness direction). Furthermore, the shape of the bottom of the micropore 22a is not particularly limited; it can be curved (convex) or planar.

[0732] L of the surface of the aluminum support 12a on the image recording layer side (the surface of the anodized film 20a on the image recording layer side) * a * b * Lightness (L) in the color system * The value is preferably 70 to 100. From the viewpoint of achieving a better balance between print durability and image visual recognizability, 75 to 100 is preferred, and 75 to 90 is more preferred.

[0733] Regarding the aforementioned brightness L * The measurements were performed using a Spectro Eye colorimeter manufactured by X-Rite Inc.

[0734] It is also preferable to adopt the following method (hereinafter, the support body involved in the above method will also be referred to as "support body (2)"). In the support body (1), the micropore is 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 depth of 10 nm to 1,000 nm. The small-diameter pore portion is connected to the bottom of the large-diameter pore portion and extends from the connection position to a depth of 20 nm to 2,000 nm. The average diameter of the large-diameter pore portion on the surface of the anodic oxide film is 15 nm to 150 nm, and the average diameter of the small-diameter pore portion at the connection position is 13 nm or less.

[0735] Figure 2 It is an aluminum support 12a, and Figure 1 A schematic cross-sectional view of one different embodiment of the aluminum support shown.

[0736] exist Figure 2 In the process, the aluminum support 12b includes an aluminum plate 18 and an anodized film 20b having micropores 22b consisting of large-diameter holes 24 and small-diameter holes 26.

[0737] The micropores 22b in the anodic oxide film 20b are composed of large-diameter pores 24 and small-diameter pores 26. The large-diameter pores 24 extend from the surface of the anodic oxide film to a depth of 10 nm to 1000 nm (depth D: reference). Figure 2 The small-diameter hole 26 is connected to the bottom of the large-diameter hole 24, and extends further from the connection position to a depth of 20nm to 2,000nm.

[0738] The large-diameter hole 24 and the small-diameter hole 26 will be described in detail below.

[0739] The average diameter of the anodic oxide film 20b in the large-diameter hole portion 24 is the same as the average diameter of the anodic oxide film surface of the micropore 22a in the anodic oxide film 20a described above, which is more than 10 nm and less than 100 nm, and preferably the same range.

[0740] The method for determining the average diameter of the anodic oxide film 20b on the surface of the large-diameter hole 24 is the same as the method for determining the average diameter of the anodic oxide film on the surface of the micropore 22a in the anodic oxide film 20a.

[0741] The bottom of the large-diameter hole 24 is located at a depth of 10 nm to 1,000 nm (hereinafter also referred to as depth D) from the surface of the anodic oxide film. That is, the large-diameter hole 24 is a hole extending from the surface of the anodic oxide film along the depth direction (thickness direction) to a position of 10 nm to 1,000 nm. The aforementioned depth is preferably 10 nm to 200 nm.

[0742] In addition, the above depth is the value obtained by taking a cross-sectional photograph (150,000x magnification) of the anodized film 20b, measuring the depth of more than 25 large-diameter holes 24, and averaging them.

[0743] The shape of the large-diameter hole 24 is not particularly limited. For example, it can be a generally straight tube (generally cylindrical) or a conical shape whose diameter decreases as it moves toward the depth direction (thickness direction). A generally straight tube is preferred.

[0744] like Figure 2 As shown, the small-diameter hole 26 is connected to the bottom of the large-diameter hole 24 and extends further along the depth direction (thickness direction) from the connection position.

[0745] The average diameter at the communication position of the small-diameter hole 26 is preferably 13 nm or less. More preferably, it is 11 nm or less, and more preferably 10 nm or less. There is no particular limitation on the lower limit, but it is generally 5 nm or more.

[0746] Regarding the average diameter of the small-diameter apertures 26, the surface of the anodic oxide film 20a was observed using a FE-SEM at 150,000x magnification with N=4 images. The diameter of the micropores (small-diameter apertures) existing in the range of 400nm × 600nm was measured in the four images obtained and obtained as an arithmetic mean. Alternatively, if the large-diameter apertures are deep, the upper part of the anodic oxide film 20b (the region with the large-diameter apertures) can be cut (e.g., by argon gas cutting), and the surface of the anodic oxide film 20b can be observed using the aforementioned FE-SEM to determine the average diameter of the small-diameter apertures.

[0747] Furthermore, when the shape of the small-diameter hole 26 is not circular, the equivalent diameter of the circle is used. The "equivalent diameter of the circle" refers to the diameter of a circle when the shape of the opening is assumed to be a circle with a projected area equal to the projected area of ​​the opening.

[0748] The bottom of the small-diameter hole 26 is located at a position extending 20 nm to 2,000 nm further along the depth direction from its communication position with the large-diameter hole 24. In other words, the small-diameter hole 26 is a hole extending further along the depth direction (thickness direction) from its communication position with the large-diameter hole 24, and the depth of the small-diameter hole 26 is 20 nm to 2,000 nm. Preferably, the depth is 500 nm to 2,000 nm.

[0749] In addition, the above depth is obtained by taking a cross-sectional photograph (50,000x magnification) of the anodized film 20b, measuring the depth of more than 25 small-diameter holes, and averaging them.

[0750] The shape of the small-diameter hole 26 is not particularly limited. For example, it can be a generally straight tube (generally cylindrical) or a conical shape whose diameter decreases with the direction of depth. A generally straight tube is preferred.

[0751] -Manufacturing method of aluminum support-

[0752] As a method for manufacturing the aluminum support used in this invention, for example, a manufacturing method that sequentially performs the following steps is preferred.

[0753] • Roughening process: The process of roughening the aluminum plate.

[0754] • Anodizing process: The process of anodizing roughened aluminum plates.

[0755] • Hole enlargement process: This process involves contacting the aluminum plate with anodized film obtained in the anodizing process with an acidic or alkaline aqueous solution to enlarge the diameter of the micropores in the anodized film.

[0756] The steps for each process are described in detail below.

[0757] [Roughening process]

[0758] The roughening process is a process of applying an electrochemical roughening treatment to the surface of the aluminum plate. This process is preferably performed before the anodizing process described later; however, if the surface of the aluminum plate already has a preferred surface shape, this process is not necessary.

[0759] Regarding roughening treatment, electrochemical roughening treatment can be performed alone, but it can also be performed in combination with mechanical roughening treatment and / or chemical roughening treatment.

[0760] In the case of a combination of mechanical roughening treatment and electrochemical roughening treatment, it is preferable to perform electrochemical roughening treatment after mechanical roughening treatment.

[0761] Electrochemical roughening treatment is preferably carried out in an aqueous solution mainly composed of nitric acid or hydrochloric acid using direct current (DC) or alternating current (AC).

[0762] There are no particular limitations on the methods of mechanical roughening treatment, but for example, the method described in Japanese Patent Publication No. 50-40047 can be cited.

[0763] There are no particular limitations to chemical roughening treatments, and well-known methods can be cited.

[0764] Preferably, the following chemical etching process is performed after mechanical roughening.

[0765] The chemical etching process performed after mechanical roughening is for the following purposes: to smooth the uneven edges of the aluminum plate surface, to prevent ink from catching on during printing, thereby improving the stain resistance of the printing plate, and to remove unwanted substances such as abrasive particles remaining on the surface.

[0766] Examples of chemical etching processes include etching using acids and etching using alkalis. Among these, chemical etching processes using alkaline aqueous solutions (hereinafter also referred to as "alkali etching processes") are particularly superior in terms of etching efficiency.

[0767] There are no particular restrictions on the alkaline agents used in alkaline solutions, but examples include sodium hydroxide, potassium hydroxide, sodium metasilicate, sodium carbonate, sodium aluminate, and sodium gluconate.

[0768] Alkaline solutions can contain aluminum ions.

[0769] The concentration of the alkaline agent in the alkaline aqueous solution is preferably 0.01% by mass or more, more preferably 3% by mass or more, and more preferably 30% by mass or less.

[0770] In the case of alkaline etching, in order to remove the products generated by alkaline etching, it is preferable to use a low-temperature acidic aqueous solution to carry out chemical etching (hereinafter also referred to as "decontamination treatment").

[0771] There are no particular limitations on the acid used in the acidic aqueous solution, but examples include sulfuric acid, nitric acid, and hydrochloric acid. Furthermore, the temperature of the acidic aqueous solution is preferably between 20°C and 80°C.

[0772] As a roughening process, it is preferable to perform the processing method shown in method A or method B in the following order.

[0773] ~Method A~

[0774] (2) Chemical etching treatment using alkaline aqueous solution (first alkaline etching treatment) was used.

[0775] (3) Chemical etching treatment using acidic aqueous solution (first decontamination treatment) was used.

[0776] (4) Electrochemical roughening treatment using an aqueous solution based on nitric acid (first electrochemical roughening treatment) was used.

[0777] (5) Chemical etching treatment using alkaline aqueous solution (second alkaline etching treatment)

[0778] (6) Chemical etching treatment using acidic aqueous solution (second decontamination treatment) was used.

[0779] (7) Electrochemical roughening treatment was carried out in an aqueous solution mainly composed of hydrochloric acid (second electrochemical roughening treatment).

[0780] (8) Chemical etching treatment using alkaline aqueous solution (third alkaline etching treatment)

[0781] (9) Chemical etching treatment using acidic aqueous solution (third cleaning treatment)

[0782] ~Method B~

[0783] (10) Chemical etching treatment using alkaline aqueous solution (4th alkaline etching treatment) was used.

[0784] (11) Chemical etching treatment using acidic aqueous solution (4th decontamination treatment) was used.

[0785] (12) Electrochemical roughening treatment using an aqueous solution mainly composed of hydrochloric acid (3rd electrochemical roughening treatment) was used.

[0786] (13) Chemical etching treatment using alkaline aqueous solution (5th alkaline etching treatment) was used.

[0787] (14) Chemical etching treatment using acidic aqueous solution (5th cleaning treatment) was used.

[0788] As needed, mechanical roughening treatment (1) can be performed before treatment (2) in method A or treatment (10) in method B.

[0789] The preferred dissolution rate of the aluminum plate in the first and fourth alkaline etching treatments is 0.5 g / m³. 2 ~30g / m 2 More preferably 1.0 g / m 2 ~20g / m 2 .

[0790] As an example of the nitric acid-based aqueous solution used in the first electrochemical roughening treatment of Method A, examples include aqueous solutions used in electrochemical roughening treatments employing direct current or alternating current. For instance, an aqueous solution obtained by adding aluminum nitrate, sodium nitrate, or ammonium nitrate to a nitric acid aqueous solution of 1–100 g / L can be cited.

[0791] The hydrochloric acid-based aqueous solution used in the second electrochemical roughening treatment in Method A and the third electrochemical roughening treatment in Method B can be an example of an aqueous solution used in electrochemical roughening treatments that employ conventional direct current or alternating current. For example, an aqueous solution obtained by adding 0 g / L to 30 g / L of sulfuric acid to a hydrochloric acid aqueous solution of 1 g / L to 100 g / L can be used. Furthermore, nitrate ions such as aluminum nitrate, sodium nitrate, and ammonium nitrate; and hydrochloric acid ions such as aluminum chloride, sodium chloride, and ammonium chloride can be further added to this solution.

[0792] The AC power waveform obtained by electrochemical roughening treatment can use sine waves, rectangular waves, trapezoidal waves, and triangular waves, etc. The preferred frequency is 0.1Hz to 250Hz.

[0793] Figure 3 This is a chart representing an example of an alternating current waveform used in electrochemical roughening treatment.

[0794] exist Figure 3 In the diagram, ta represents the anode reaction time, tc represents the cathode reaction time, tp represents the time it takes for the current to reach its peak value from 0, Ia represents the peak current on the anode circulation side, Ic represents the peak current on the cathode circulation side, AA represents the anode reaction current of the aluminum plate, and CA represents the cathode reaction current of the aluminum plate. In the trapezoidal wave, the time tp for the current to reach its peak value from 0 is preferably 1 ms to 10 ms. The preferred conditions for one cycle of AC current used for electrochemical roughening are: the ratio of the anode reaction time ta to the cathode reaction time tc of the aluminum plate (tc / ta) is 1 to 20; the ratio of the charge Qc when the aluminum plate is the cathode to the charge Qa when the aluminum plate is the anode (Qc / Qa) is 0.3 to 20; and the anode reaction time ta is in the range of 5 ms to 1,000 ms. Regarding the current density, the peak current on both the anode circulation side (Ia) and the cathode circulation side (Ic) of the trapezoidal wave is preferably 10 A / dm³. 2 ~200A / dm 2 The Ic / Ia ratio is preferably 0.3 to 20. The total charge participating in the anodic reaction of the aluminum plate at the end of the electrochemical roughening is preferably 25 C / dm². 2 ~1,000C / dm 2 .

[0795] Electrochemical roughening using alternating current can be used Figure 4 The apparatus shown.

[0796] Figure 4 This is a side view showing an example of a radial unit in an electrochemical roughening process using alternating current.

[0797] Figure 4 In the diagram, 50 is the main electrolytic cell, 51 is the AC power supply, 52 is the radial drum roller, 53a and 53b are the main electrodes, 54 is the electrolyte supply port, 55 is the electrolyte, 56 is the slit, 57 is the electrolyte channel, 58 is the auxiliary anode, 60 is the auxiliary anode tank, and W is the aluminum plate. Figure 4 In the diagram, arrow A1 indicates the direction of electrolyte supply, and arrow A2 indicates the direction of electrolyte discharge. When using two or more electrolytic cells, the electrolysis conditions can be the same or different.

[0798] An aluminum plate W is rolled onto a radial drum roller 52, which is immersed in the main electrolytic cell 50, and electrolyzed during transport via main electrodes 53a and 53b connected to an AC power supply 51. Electrolyte 55 is supplied from the electrolyte supply port 54 through a slit 56 to the electrolyte channel 57 between the radial drum roller 52 and the main electrodes 53a and 53b. The aluminum plate W, after being treated in the main electrolytic cell 50, is then electrolyzed in an auxiliary anode tank 60. In this auxiliary anode tank 60, an auxiliary anode 58 is positioned opposite the aluminum plate W, and electrolyte 55 is supplied in a manner that flows through the space between the auxiliary anode 58 and the aluminum plate W.

[0799] From the viewpoint of facilitating the manufacture of the original printing plate as specified, the amount of aluminum plate dissolved in the second alkaline etching process is preferably 1.0 g / m². 2 More preferably 2.0 g / m 2 ~10g / m 2 .

[0800] From the viewpoint of facilitating the manufacture of the specified original printing plate, the amount of aluminum plate dissolved in the third and fourth alkaline etching processes is preferably 0.01 g / m². 2 ~0.8g / m 2 More preferably 0.05g / m 2 ~0.3g / m 2 .

[0801] In chemical etching processes (decontamination processes 1 to 5) using acidic aqueous solutions, it is preferable to use an acidic aqueous solution containing phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixture of two or more of these acids.

[0802] The concentration of acid in the acidic aqueous solution is preferably 0.5% to 60% by mass.

[0803] [Anodizing process]

[0804] There are no particular restrictions on the steps of the anodizing process, as long as the aforementioned micropores can be obtained, and well-known methods can be cited.

[0805] In the anodizing process, aqueous solutions of sulfuric acid, phosphoric acid, and oxalic acid can be used as electrolytic cells. For example, the concentration of sulfuric acid can range from 100 g / L to 300 g / L.

[0806] The conditions for anodizing can be appropriately set according to the electrolyte used, but examples include a electrolyte temperature of 5°C to 70°C (preferably 10°C to 60°C) and a current density of 0.5 A / dm³. 2 ~60A / dm 2 (Preferred 1A / dm) 2 ~60A / dm 2 The voltage is 1V to 100V (preferably 5V to 50V), the electrolysis time is 1 second to 100 seconds (preferably 5 seconds to 60 seconds), and the film weight is 0.1g / m³. 2 ~5g / m 2 (Preferred value: 0.2g / m) 2 ~3g / m 2 ).

[0807] [Hole Enlargement Treatment]

[0808] The pore enlargement process is a process that increases the diameter (pore size) of the micropores existing in the anodic oxide film formed by the above-mentioned anodic oxidation process (pore size enlargement process).

[0809] The hole-enlarging process can be performed by contacting the aluminum plate obtained through the above-described anodizing process with an acidic or alkaline aqueous solution. There are no particular limitations on the contact method; for example, immersion and spraying methods can be used.

[0810] <Undercoat>

[0811] The lithographic printing plate master according to the present invention preferably has a base coating (also referred to as an intermediate layer) between the image recording layer and the support. The base coating enhances the adhesion between the support and the image recording layer in the exposed area and facilitates the peeling of the image recording layer from the support in the unexposed area. Therefore, the base coating helps improve developability without compromising print durability. Furthermore, in the case of infrared laser exposure, the base coating functions as a heat insulation layer, thereby preventing the heat generated by exposure from diffusing to the support and reducing sensitivity.

[0812] Examples of compounds used in the primer coating include polymers having adsorbent and hydrophilic groups that can be adsorbed onto the surface of the support. To improve adhesion to the image recording layer, polymers having adsorbent and hydrophilic groups, as well as crosslinking groups, are preferred. The compounds used in the primer coating can be low-molecular-weight compounds or polymers. Two or more compounds used in the primer coating may be mixed as needed.

[0813] When the compound used in the primer is a polymer, copolymers of monomers having adsorption groups, monomers having hydrophilic groups, and monomers having crosslinking groups are preferred.

[0814] As adsorbent groups capable of adsorbing onto the surface of the support, phenolic hydroxyl groups, carboxyl groups, -PO3H2, -OPO3H2, -CONHSO2-, -SO2NHSO2-, and -COCH2COCH3 are preferred. As hydrophilic groups, sulfonyl groups or their salts, and carboxyl salts are preferred. As crosslinking groups, acryloyl groups, methacrylyl groups, acrylamido groups, methacrylamido groups, and allyl groups are preferred.

[0815] The polymer may have crosslinking groups introduced by the formation of salts of compounds containing polar substituents of the polymer and substituents with charges opposite to those of the aforementioned polar substituents and olefinic unsaturated bonds, and may be further copolymerized with monomers other than those described above, preferably hydrophilic monomers.

[0816] Specifically, preferred examples include silane coupling agents having olefinic double-bond reactive groups capable of addition polymerization as described in Japanese Patent Application Publication No. 10-282679, and phosphorus compounds having olefinic double-bond reactive groups as described in Japanese Patent Application Publication No. 2-304441. Low-molecular-weight or high-molecular-weight compounds having crosslinking groups (preferably olefinic unsaturated groups), functional groups interacting with the support surface, and hydrophilic groups as described in Japanese Patent Application Publication Nos. 2005-238816, 2005-125749, 2006-239867, and 2006-215263 are also preferred.

[0817] As a more preferred compound, examples include the polymers described in Japanese Patent Application Publication Nos. 2005-125749 and 2006-188038, which are adsorbent groups that can be adsorbed onto the surface of a support, and polymers having hydrophilic groups and crosslinking groups.

[0818] The content of olefinic unsaturated groups in the polymer used in the primer coating is preferably 0.1 mmol to 10.0 mmol per 1g of polymer, more preferably 0.2 mmol to 5.5 mmol.

[0819] The weight-average molecular weight (Mw) of the polymer used in the base coating is preferably 5,000 or more, and more preferably 10,000 to 300,000.

[0820] [Hydrophilic compounds]

[0821] From a developmental point of view, the base coating preferably contains a hydrophilic compound.

[0822] There are no particular restrictions on the use of hydrophilic compounds; any known hydrophilic compounds used in the base coat can be used.

[0823] Examples of hydrophilic compounds include carboxymethyl cellulose, dextrin and other amino-containing phosphonic acids, organophosphonic acids, organophosphoric acids, organosphinic acids, amino acids, and amine hydrochlorides containing hydroxyl groups.

[0824] Furthermore, as hydrophilic compounds, compounds having an amino group or a functional group with polymerization inhibition ability and a group that interacts with the surface of the support are preferred (e.g., 1,4-diazabicyclo[2.2.2]octane (DABCO), 2,3,5,6-tetrahydroxy-p-benzoquinone, chloroquinone, sulfophthalic acid, ethylenediaminetetraacetic acid (EDTA) or its salts, hydroxyethylethylenediaminetriacetic acid or its salts, dihydroxyethylethylenediaminediacetic acid or its salts, hydroxyethyliminodiacetic acid, etc. or their salts).

[0825] From the viewpoint of scratch stain inhibition, hydrophilic compounds preferably contain hydroxycarboxylic acids or their salts.

[0826] Furthermore, from the viewpoint of scratch stain suppression, a hydrophilic compound, preferably a hydroxycarboxylic acid or its salt, is preferably included in the layer on the aluminum support. Moreover, the layer on the aluminum support is preferably the layer on the side where the image recording layer is formed, and preferably the layer in contact with the aluminum support.

[0827] As a layer on the aluminum support, and as a layer in contact with the aluminum support, a base coating or an image recording layer is preferably provided. Furthermore, layers other than the layer in contact with the aluminum support, such as a protective layer or an image recording layer, may contain hydrophilic compounds, preferably hydroxycarboxylic acids or their salts.

[0828] In the lithographic printing plate original involved in this invention, from the viewpoint of scratch contamination inhibition, the image recording layer preferably contains hydroxycarboxylic acid or its salt.

[0829] Furthermore, in the lithographic printing plate originals according to the present invention, it is preferable to perform surface treatment on the surface of the image recording layer side of the aluminum support using a composition (e.g., an aqueous solution) containing at least a hydroxycarboxylic acid or its salt. In the above-described manner, at least a portion of the treated hydroxycarboxylic acid or its salt can be detected as being contained in the layer (e.g., the image recording layer or the undercoat layer) on the image recording layer side in contact with the aluminum support.

[0830] By including hydroxycarboxylic acid or its salt in the layer on the image recording layer side that contacts the aluminum support, such as the base coating, the surface of the image recording layer side of the aluminum support can be made hydrophilic. Furthermore, the contact angle with water on the surface of the image recording layer side of the aluminum support based on the air droplet method can be easily set to 110° or less, resulting in excellent scratch contamination suppression.

[0831] Hydroxycarboxylic acids are a general term for organic compounds that have one or more carboxyl groups and one or more hydroxy groups in one molecule. They are also called hydroxy acids, oxyacids, hydroxycarboxylic acids, and alcohols (refer to Iwanami Rika Dictionary, 5th edition, Iwanami Shoten, 1998).

[0832] The above-mentioned hydroxycarboxylic acid or its salt is preferably represented by the following formula (HC).

[0833] R HC (OH) mhc (COOM) HC ) nhc Formula (HC)

[0834] In formula (HC), R HC M represents an organic group with the valence of mhc+nhc. HC Each can independently represent a hydrogen atom, an alkali metal, or onium. mhc and nhc can independently represent integers greater than 1. When n is greater than 2, M can be the same or different.

[0835] In equation (HC), as a result of R HC The organic group represented by the MHC+NHC valence can include hydrocarbon groups, etc. Hydrocarbon groups may have substituents and / or linking groups.

[0836] Examples of hydrocarbon groups include those with an MHC+NHC valence derived from aliphatic hydrocarbons, such as alkylene, alkane triyl, alkane tetrayl, alkane pentayl, alkenylene, alkene triyl, alkene tetrayl, alkene pentayl, alkyneylene, alkyne triyl, alkyne tetrayl, alkyne pentayl, etc.; and those with an MHC+NHC valence derived from aromatic hydrocarbons, such as arylene, aromatic triyl, aromatic tetrayl, aromatic pentayl, etc. Examples of substituents other than hydroxyl and carboxyl groups include alkyl, alkenyl, alkynyl, aralkyl, aryl, etc. Specific examples of substituents include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 1-methylbutyl, isohexyl, 2-ethylhexyl, 2-methylhexyl, cyclohexyl, cyclopentyl, 2-norbornyl, methoxymethyl, methoxyethoxyethyl, allyloxymethyl, phenoxymethyl, acetoxymethyl, benzoyloxymethyl The group may contain alkyl, benzyl, phenethyl, α-methylbenzyl, 1-methyl-1-phenylethyl, p-methylbenzyl, cinnamyl, allyl, 1-propenylmethyl, 2-butenyl, 2-methylallyl, 2-methylpropenylmethyl, 2-propynyl, 2-butynyl, 3-butynyl, phenyl, biphenyl, naphthyl, tolyl, xylyl, mesitylexyl, cumenel, methoxyphenyl, ethoxyphenyl, phenoxyphenyl, acetoxyphenyl, benzoyloxyphenyl, methoxycarbonylphenyl, ethoxycarbonylphenyl, phenoxycarbonylphenyl, etc. Furthermore, the linking group is composed of at least one atom selected from the group consisting of hydrogen, carbon, oxygen, nitrogen, sulfur, and halogen atoms, and the number of atoms is preferably 1 to 50. Specifically, alkylene, substituted alkylene, aryl, substituted aryl, etc., can be examples, and the structure may have multiple of these divalent groups linked by any one of amide bonds, ether bonds, carbamate bonds, urea bonds, and ester bonds.

[0837] As a result of M HC Examples of alkali metals that can be represented include lithium, sodium, and potassium, with sodium being particularly preferred. Examples of onium metals include ammonium, phosphorus, and matte, with ammonium being particularly preferred.

[0838] Furthermore, from the perspective of scratch stain inhibition, M HC Preferably, it is an alkali metal or onium, more preferably an alkali metal.

[0839] The total number of MHC and NHC is preferably 3 or more, more preferably 3 to 8, and even more preferably 4 to 6.

[0840] The molecular weight of the aforementioned hydroxycarboxylic acid or its salt is preferably 600 or less, more preferably 500 or less, and particularly preferably 300 or less. Furthermore, the molecular weight is preferably 76 or more.

[0841] Specifically, examples of hydroxycarboxylic acids or salts of the aforementioned hydroxycarboxylic acids include gluconic acid, glycolic acid, lactic acid, malonic acid, hydroxybutyric acid (2-hydroxybutyric acid, 3-hydroxybutyric acid, γ-hydroxybutyric acid, etc.), malic acid, tartaric acid, citric acid, isocitrate, leucine, mevalonic acid, pantothenic acid, ricinoleic acid, trans-ricinoleic acid, cerebroside, quinic acid, shikimic acid, and monohydroxybenzoic acid derivatives (salicylic acid, lignoceric acid, etc.). Salicylic acid, hydroxy(methyl)benzoic acid, vanillic acid, syringic acid, etc., dihydroxybenzoic acid derivatives (pyrocatechuic acid, dihydroxybenzoic acid, protocatechuic acid, gentianic acid, sphagnum mossolic acid, etc.), trihydroxybenzoic acid derivatives (gallic acid, etc.), phenylacetic acid derivatives (mandelic acid, diphenylethanolic acid, arbutinic acid, etc.), hydrogenated cinnamic acid derivatives (salicylic acid, phloroglucinic acid, coumaric acid, umbelliferic acid, caffeic acid, ferulic acid, sinapic acid, cerebrolysinic acid, carmine acid, etc.), etc.

[0842] Among these, from the viewpoint of scratch stain inhibition, compounds having two or more hydroxyl groups are preferred as the aforementioned hydroxycarboxylic acid or salts constituting the aforementioned hydroxycarboxylic acid, compounds having three or more hydroxyl groups are more preferred, compounds having five or more hydroxyl groups are even more preferred, and compounds having five to eight hydroxyl groups are particularly preferred.

[0843] Furthermore, gluconic acid or shikimic acid is preferred as a compound having one carboxyl group and two or more hydroxyl groups.

[0844] Citric acid or malic acid is preferred as a compound having two or more carboxyl groups and one hydroxyl group.

[0845] Tartaric acid is preferred as a compound having two or more carboxyl groups and hydroxyl groups respectively.

[0846] Of these, gluconic acid is particularly preferred as the hydroxycarboxylic acid mentioned above.

[0847] Hydrophilic compounds can be used alone or in combination with two or more.

[0848] When the base coating 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% to 50% by mass, more preferably 0.1% to 40% by mass, and especially preferably 1.0% to 30% by mass, relative to the total mass of the base coating.

[0849] In addition to the compounds mentioned above, the primer coating may also contain chelating agents, secondary or tertiary amines, polymerization inhibitors, etc., to prevent contamination over time.

[0850] The primer layer can be applied using known methods. The preferred coating weight (solid content) is 0.1 mg / m³.2 ~100mg / m 2 More preferably 1 mg / m 2 ~30mg / m 2 .

[0851] <Protective Layer>

[0852] The lithographic printing plate master involved in this invention may have a protective layer (sometimes also called an outer coating) on ​​the image recording layer. In addition to inhibiting the image formation inhibition reaction by blocking oxygen, the protective layer also has the functions of preventing scratches in the image recording layer and preventing ablation during high-intensity laser exposure.

[0853] Protective layers with such properties are described, for example, in U.S. Patent No. 3,458,311 and Japanese Patent Publication No. 55-49729. As the low-oxygen permeability polymer used in the protective layer, either a water-soluble polymer or a water-insoluble polymer can be appropriately selected, and two or more types can be mixed as needed. Specifically, examples include polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, water-soluble cellulose derivatives, and poly(meth)acrylonitrile.

[0854] As a modified polyvinyl alcohol, acid-modified polyvinyl alcohol having carboxyl or sulfonyl groups is preferred. Specifically, the modified polyvinyl alcohols described in Japanese Patent Application Publication Nos. 2005-250216 and 2006-259137 can be cited as examples.

[0855] To improve oxygen barrier properties, the protective layer preferably contains inorganic layered compounds. Inorganic layered compounds are particles with thin, flat, plate-like shapes, such as natural mica, synthetic mica, talc (represented by the formula 3MgO•4SiO•H2O), monzocarpite, montmorillonite, saponite, lithium montmorillonite, zirconium phosphate, etc.

[0856] The preferred inorganic layered compound is a mica compound. Examples of mica compounds include those with the formula: A(B, C). 2-5 D4O 10 (OH, F, O)₂ [where A is any one of K, Na, Ca, B and C are any one of Fe(II), Fe(III), Mn, Al, Mg, V, and D is Si or Al.] represents the mica group including natural mica and synthetic mica.

[0857] Within the mica group, natural mica includes muscovite, sodium mica, phlogopite, biotite, and scaly mica. Synthetic mica includes fluorophlogopite KMg3(AlSi3O4). 10 F2, potassium tetrasilica KMg 2.5 (Si4O) 10Non-swellable mica such as F2 and Na tetrafluorosilica NaMg 2.5 (Si4O) 10 F2, Na or Li with mica (Na, Li) Mg2Li (Si4O) 10 F2, montmorillonite series Na or Li lithium montmorillonite (Na, Li) 1 / 8 Mg 2 / 5 Li 1 / 8 (Si4O) 10 F2 and other swelling mica, etc. Furthermore, it is also used in the synthesis of green clay.

[0858] Among the aforementioned mica compounds, fluorine-based swelling mica is particularly useful. Specifically, swelling synthetic mica possesses a layered structure comprising unit lattice layers approximately 10 Å to 15 Å thick (1 Å = 0.1 nm), with significant metal atom substitution within the lattice compared to other clay minerals. Consequently, the lattice layers exhibit a lack of positive charge, which is compensated for by the adsorption of Li into the interlayer spaces. + Na + Ca 2+ Mg 2+ Oxygen ions. These interlayer oxygen ions are called exchangeable oxygen ions, and they can exchange with various oxygen ions. In particular, the interlayer oxygen ions are Li. + Na + In this state, the ionic radius is small, resulting in weak bonding between the layered lattice layers, leading to significant swelling upon contact with water. If shear force is applied in this state, it easily breaks down, forming a stable sol in water. This tendency is strong in synthetic mica with swelling properties, making it particularly preferred.

[0859] From the perspective of controlling diffusion, the thinner the mica compound, the better; however, the larger the planar dimension, the better, as long as it does not inhibit the smoothness of the coating surface or the transmissibility of activated light. Therefore, the aspect ratio is preferably 20 or more, more preferably 100 or more, and especially 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, from the projection of a particle-based microscopic photograph. The larger the aspect ratio, the greater the effect obtained.

[0860] Regarding the particle size of the mica compound, its average major diameter is preferably 0.3 μm to 20 μm, more preferably 0.5 μm to 10 μm, and particularly preferably 1 μm to 5 μm. The average thickness of the particles is preferably 0.1 μm or less, more preferably 0.05 μm or less, and particularly preferably 0.01 μm or less. Specifically, for example, when using a swollen synthetic mica as a representative compound, a thickness of 1 nm to 50 nm and a planar dimension (major diameter) of approximately 1 μm to 20 μm are preferred.

[0861] The content of the inorganic layered compound relative to the total solids content of the protective layer is preferably 1% to 60% by mass, more preferably 3% to 50% by mass. Even when multiple inorganic layered compounds are used simultaneously, the total amount of inorganic layered compounds is preferably at the above-mentioned content. Within the above range, oxygen barrier properties are improved, and good sensitivity can be obtained. Furthermore, it is possible to prevent a decrease in ink adhesion.

[0862] -Color-changing compounds-

[0863] Furthermore, the aforementioned protective layer preferably contains a color-changing compound.

[0864] In addition to color-changing compounds, the aforementioned protective layer may also contain other components such as water-soluble polymers, hydrophobic polymers, sensitizers, acid-producing agents, and infrared absorbers.

[0865] In the lithographic printing plate original involved in this invention, from the viewpoint of improving the visual recognizability of the exposed area, 110mJ / cm 2 The brightness change ΔL before and after exposure to infrared light with an energy density of 830 nm is preferably 2.0 or higher.

[0866] The aforementioned lightness change ΔL is more preferably 3.0 or more, further preferably 5.0 or more, especially preferably 8.0 or more, and most preferably 10.0 or more.

[0867] As an upper limit for the change in brightness ΔL, for example, 20.0 can be cited.

[0868] Furthermore, especially when a protective layer containing a color-changing compound is present, it is preferable to satisfy the aforementioned preferred numerical range of the lightness change ΔL.

[0869] The change in lightness ΔL was measured using the following method.

[0870] The Luxel PLATESETTER T-9800, manufactured by FUJIFILM Graphic Systems Co., Ltd., equipped with an 830nm infrared semiconductor laser, achieved an energy density of 110mJ / cm² under the following conditions: 99.5% output, 220rpm outer drum speed, and 2,400dpi resolution (dots per inch, 1 inch = 25.4mm). 2 The original offset printing plate is exposed under the following conditions. Exposure is performed at 25°C and 50% RH.

[0871] The brightness change of the original lithographic printing plate before and after exposure was measured.

[0872] The measurements were performed using an eXact spectrochromatic meter manufactured by X-Rite Inc. Using L... * a * b * L in color scheme * The value (brightness) represents the L value of the image recording layer after exposure. * Value and L of the image recording layer before exposure * The absolute value of the difference in values ​​is taken as the change in brightness ΔL.

[0873] In this invention, "color-changing compound" refers to a compound whose absorption in the visible light region (wavelength: above 400 nm and below 750 nm) changes due to infrared exposure. That is, in this invention, "color change" refers to the change in absorption in the visible light region (wavelength: above 400 nm and below 750 nm) due to infrared exposure.

[0874] Specifically, regarding the color-changing compounds of the present invention, examples include (1) compounds whose absorption in the visible light region increases due to infrared exposure compared to before infrared exposure, (2) compounds whose absorption in the visible light region increases due to infrared exposure, and (3) compounds whose absorption in the visible light region does not increase due to infrared exposure.

[0875] In addition, the infrared light in this invention is light with a wavelength of 750nm to 1mm, preferably light with a wavelength of 750nm to 1,400nm.

[0876] As a color-changing compound, it is preferable to include a compound that develops color upon exposure to infrared light.

[0877] Furthermore, as a color-changing compound, it is preferable to include a decomposable compound that decomposes due to infrared exposure, wherein it is preferable to include a decomposable compound that decomposes through heat, electron transfer or both caused by infrared exposure.

[0878] More specifically, the color-changing compound in this invention is preferably a compound that decomposes upon infrared exposure (more preferably through thermal or electron transfer or both caused by infrared exposure), and whose absorption in the visible light region is increased or shortened in wavelength compared to before infrared exposure, and which has absorption in the visible light region.

[0879] Here, "decomposition by electron transfer" refers to the process by which electrons excited from the HOMO (highest occupied orbital) of the color-changing compound to the LUMO (lowest unoccupied molecular orbital) are transferred within the molecule to electron-accepting groups (groups with potential close to the LUMO), thereby causing decomposition.

[0880] The following describes a decomposing compound as an example of a color-changing compound.

[0881] Regarding decomposable compounds, any compound that absorbs at least a portion of light in the infrared wavelength region (750 nm to 1 mm wavelength region, preferably 750 nm to 1,400 nm wavelength region) and decomposes it is acceptable, but compounds that have extremely high absorption in the 750 nm to 1,400 nm wavelength region are preferred.

[0882] More specifically, the decomposable compound is preferably a compound that decomposes upon exposure to infrared light and generates a compound having a large absorption wavelength in the wavelength region of 500 nm to 600 nm.

[0883] From the viewpoint of improving the visual recognizability of the exposed portion, the decomposable compound is preferably one having a group that decomposes upon infrared exposure (specifically, R in general formulas 1-1 to 1-7 below). 1 Anthocyanins.

[0884] From the viewpoint of improving the visual recognizability of the exposed portion, a compound represented by the following formula 1-1 is more preferred as a decomposition compound.

[0885] [Chemical Formula 57]

[0886]

[0887] In Equation 1-1, R 1 R represents a group represented by any one of the following formulas 2 to 4. 11 ~R 18 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -SR c or -NR d R e R a ~R e Each of the following groups independently represents a hydrocarbon group: A1, A2, and multiple R groups. 11 ~R 18 They can be linked to form single or multiple rings, where A1 and A2 independently represent oxygen, sulfur, or nitrogen atoms, respectively, and n 11 and n 12 Each of the integers from 0 to 5 can be represented independently, where n 11 and n 12 The total is 2 or more, n 13 and n 14 Each can be independently represented as 0 or 1, and L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 It represents a hydrogen atom, alkyl group, or aryl group; Za represents a counterion that neutralizes the charge.

[0888] [Chemical Formula 58]

[0889]

[0890] In equations 2 to 4, R 20 R 30 R 41 and R 42 Each group independently represents an alkyl or aryl group, Zb represents a counterion that neutralizes the charge, and the wavy line represents the bonding site with the group represented by L in Formula 1-1.

[0891] If the compound represented by Equation 1-1 is exposed to infrared light, then R 1 The -L bond breaks, and L becomes =O, =S, or =NR. 10 This causes it to change color.

[0892] In Equation 1-1, R 1 It represents a group represented by any one of the above formulas 2 to 4.

[0893] The groups represented by Formula 2, Formula 3, and Formula 4 will be explained below.

[0894] In Equation 2, R 20 The wavy line indicates an alkyl or aryl group, and the wavy line indicates the bonding site with the group represented by L in Formula 1-1.

[0895] As by R20 The alkyl group indicated is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms.

[0896] The alkyl groups mentioned above can be straight-chain, branched, or have a cyclic structure.

[0897] As a result of R 20 The aryl group represented is preferably an aryl group with 6 to 30 carbon atoms, more preferably an aryl group with 6 to 20 carbon atoms, and even more preferably an aryl group with 6 to 12 carbon atoms.

[0898] As R 20 From the viewpoint of color development, alkyl groups are preferred.

[0899] Furthermore, from the perspective of decomposition and color development, as a product of R... 20 The alkyl group indicated is preferably a secondary alkyl group or a tertiary alkyl group, with a preference for a tertiary alkyl group.

[0900] Furthermore, from the viewpoint of decomposition and color development, as a product of R... 20The alkyl group represented is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a branched alkyl group having 3 to 10 carbon atoms, even more preferably a branched alkyl group having 3 to 6 carbon atoms, particularly preferably isopropyl or tert-butyl, and most preferably tert-butyl.

[0901] Hereinafter, specific examples of groups represented by Formula 2 above are given, but the present invention is not limited to these. In the following structural formulas, ● indicates the bonding site with the group represented by L in Formula 1-1.

[0902] [Chemical Formula 59]

[0903]

[0904] In Equation 3, R 30 The wavy line indicates an alkyl or aryl group, and the wavy line indicates the bonding site with the group represented by L in Formula 1-1.

[0905] As a result of R 30 The alkyl and aryl groups represented are related to R in Formula 2. 20 The alkyl and aryl groups are represented by the same terms, and the preferred methods are also the same.

[0906] From the perspective of decomposition and color development, as a result of R 30 The alkyl group indicated is preferably a secondary alkyl group or a tertiary alkyl group, with a preference for a tertiary alkyl group.

[0907] Furthermore, from the perspective of decomposition and color development, as a product of R... 30 The alkyl group represented is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a branched alkyl group having 3 to 10 carbon atoms, even more preferably a branched alkyl group having 3 to 6 carbon atoms, particularly preferably isopropyl or tert-butyl, and most preferably tert-butyl.

[0908] Furthermore, from the perspective of decomposition and color development, R 30 The alkyl group represented is preferably a substituted alkyl group, more preferably a fluorinated substituted alkyl group, even more preferably a perfluoroalkyl group, and especially preferably a trifluoromethyl group.

[0909] From the perspective of decomposition and color development, by R 30 The aryl group represented is preferably a substituted aryl group. Examples of substituents include alkyl groups (preferably alkyl groups with 1 to 4 carbon atoms) and alkoxy groups (preferably alkoxy groups with 1 to 4 carbon atoms).

[0910] Hereinafter, specific examples of groups represented by Formula 3 above are given, but the present invention is not limited to these. In the following structural formulas, ● indicates the bonding site with the group represented by L in Formula 1-1.

[0911] [Chemical Formula 60]

[0912]

[0913] In Equation 4, R 41 and R 42 Each group independently represents an alkyl or aryl group, Zb represents a counterion that neutralizes the charge, and the wavy line represents the bonding site with the group represented by L in Formula 1-1.

[0914] As a result of R 41 Or R 42 The alkyl and aryl groups represented are related to R in Formula 2. 20 The alkyl and aryl groups are represented by the same terms, and the preferred methods are also the same.

[0915] As R 41 From the viewpoint of decomposition and color development, alkyl groups are preferred.

[0916] As R 42 From the viewpoint of decomposition and color development, alkyl groups are preferred.

[0917] From the perspective of decomposition and color development, as a result of R 41 The alkyl group indicated is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably methyl.

[0918] From the perspective of decomposition and color development, as a result of R 42 The alkyl group indicated is preferably a secondary alkyl group or a tertiary alkyl group, with a preference for a tertiary alkyl group.

[0919] Furthermore, from the perspective of decomposition and color development, as a product of R... 42 The alkyl group represented is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a branched alkyl group having 3 to 10 carbon atoms, even more preferably a branched alkyl group having 3 to 6 carbon atoms, particularly preferably isopropyl or tert-butyl, and most preferably tert-butyl.

[0920] Regarding Zb in Formula 4, it can be any counterion used to neutralize the charge, and as a whole compound, it can also be included in Za in Formula 1-1.

[0921] Zb is preferably a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a p-toluenesulfonate ion, or a perchlorate ion, and more preferably a tetrafluoroborate ion.

[0922] Hereinafter, specific examples of groups represented by Formula 4 above are given, but the present invention is not limited to these. In the following structural formulas, ● indicates the bonding site with the group represented by L in Formula 1-1.

[0923] [Chemical Formula 61]

[0924]

[0925] In Equation 1-1, L is preferably an oxygen atom or -NR. 10 - Oxygen atoms are particularly preferred.

[0926] Furthermore, -NR 10 -in R 10 Alkyl groups are preferred. As a component of R... 10 The alkyl group represented is preferably an alkyl group having 1 to 10 carbon atoms. Furthermore, R... 10 The alkyl group can be straight-chain, branched, or cyclic.

[0927] Among the alkyl groups, methyl or cyclohexyl is preferred.

[0928] In -NR 10 -in R 10 When the aryl group is aryl, it is preferably an aryl group with 6 to 30 carbon atoms, more preferably an aryl group with 6 to 20 carbon atoms, and even more preferably an aryl group with 6 to 12 carbon atoms. Furthermore, these aryl groups may have substituents.

[0929] In Equation 1-1, R 11 ~R 18 Each independently represents a hydrogen atom and -R a -OR b -SR c or -NR d R e .

[0930] By R a ~R e The hydrocarbon group represented is preferably a hydrocarbon group with 1 to 30 carbon atoms, more preferably a hydrocarbon group with 1 to 15 carbon atoms, and even more preferably a hydrocarbon group with 1 to 10 carbon atoms.

[0931] The aforementioned hydrocarbon groups can be straight-chain, branched, or have a ring structure.

[0932] Alkyl groups are particularly preferred as the aforementioned hydrocarbon groups.

[0933] As the aforementioned alkyl group, alkyl groups having 1 to 30 carbon atoms are preferred, alkyl groups having 1 to 15 carbon atoms are more preferred, and alkyl groups having 1 to 10 carbon atoms are even more preferred.

[0934] The alkyl groups mentioned above can be straight-chain, branched, or have a cyclic structure.

[0935] Specifically, examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 1-methylbutyl, isohexyl, 2-ethylhexyl, 2-methylhexyl, cyclohexyl, cyclopentyl, and 2-norbenzyl.

[0936] Among the alkyl groups, methyl, ethyl, propyl or butyl are preferred.

[0937] The alkyl groups mentioned above may have substituents.

[0938] Examples of substituents include alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, carboxylic acid ester, sulfonyl, sulfonate, alkoxycarbonyl, aryloxycarbonyl, and groups formed by combining them.

[0939] R in Equation 1-1 11 ~R 14 Each is preferably a hydrogen atom or -R, independently. a (i.e., hydrocarbon group), more preferably hydrogen atom or alkyl group, and even more preferably hydrogen atom except in the following cases.

[0940] Among them, R is bonded to the carbon atom bonded to the carbon atom bonded to L. 11 and R 13 Alkyl groups are preferred, and the two are more preferably linked to form a ring. The ring formed can be a monocyclic or polycyclic ring. Specifically, examples of the formed ring include monocyclic rings such as cyclopentene ring, cyclopentadiene ring, cyclohexene ring, and cyclohexadiene ring, as well as polycyclic rings such as indene ring and indole ring.

[0941] Furthermore, in A1 + R bonded to the bonded carbon atom 12 Preferred and R 15 Or R 16 (Preferred to be R) 16 The links form a ring, with R bonded to the carbon atom bonded to A2. 14 Preferred and R 17 Or R 18 (Preferred to be R) 18 They are connected to form a ring.

[0942] In Equation 1-1, n is preferred. 13 R is 1. 16 -R a (i.e., hydrocarbon group).

[0943] Furthermore, R 16 Preferred and in A1 + R bonded to the bonded carbon atom 12The rings are linked together to form a ring. Preferably, the ring is an indole ring, a pyranonium ring, a thiopyridinium ring, a benzoxazoline ring, or a benzimidazolinium ring; from the viewpoint of improving the visual recognizability of the exposed portion, an indole ring is more preferred. These rings may also have substituents.

[0944] In Equation 1-1, n is preferred. 14 R is 1. 18 -R a (i.e., hydrocarbon group).

[0945] Furthermore, R 18 Preferably, R is bonded to the carbon atom bonded to A2. 14 The rings are linked together to form a ring. Preferably, the ring is an indole ring, a pyran ring, a thiopyran ring, a benzoxazole ring, or a benzimidazole ring; from the viewpoint of improving the visual recognizability of the exposed portion, an indole ring is more preferred. These rings may also have substituents.

[0946] R in Equation 1-1 16 and R 18 Preferably, the same groups are formed, and if each forms a ring, it is preferable to form a ring other than A1. + All rings except A2 have the same structure.

[0947] R in Equation 1-1 15 and R 17 Preferably, they are the same group. And, R 15 and R 17 Preferred is -R a (i.e., hydrocarbon group), more preferably alkyl, and even more preferably substituted alkyl.

[0948] In the compounds represented by formula 1-1, from the viewpoint of improving water solubility, R 15 and R 17 Preferably, it is a substituted alkyl group.

[0949] As a result of R 15 Or R 17 The substituted alkyl group can be represented by any one of the following formulas (a1) to (a4).

[0950] [Chemical Formula 62]

[0951]

[0952] In equations (a1) to (a4), R W0 Indicates an alkylene group with 2 to 6 carbon atoms, where W represents a single bond or an oxygen atom, and n W1 R represents integers from 1 to 45. W1 Alkyl groups with 1 to 12 carbon atoms or -C(=O)-R W5 RW5 R represents an alkyl group having 1 to 12 carbon atoms. W2 ~R W4 Each of these can be independently represented by a single bond or an alkylene group having 1 to 12 carbon atoms, with M representing a hydrogen atom, sodium atom, potassium atom, or onnnyl group.

[0953] In equation (a1), as a result of R W0 Specific examples of the alkylene group may include ethylene, n-propylene, isopropylene, n-butylene, isobutylene, n-pentylene, isopentylene, n-hexylene, isohexylene, etc., with ethylene, n-propylene, isopropylene or n-butylene being preferred, and n-propylene being particularly preferred.

[0954] n W1 Preferably 1 to 10, more preferably 1 to 5, and especially preferably 1 to 3.

[0955] As a result of R W1 Specific examples of the alkyl group may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-octyl, n-dodecyl, etc., with methyl, ethyl, n-propyl, isopropyl or n-butyl, tert-butyl being preferred, methyl or ethyl being even more preferred, and methyl being particularly preferred.

[0956] By R W5 The alkyl group represented by R W1 The alkyl group represented is the same, and the preferred method is also the same as that represented by R. W1 The preferred method for representing alkyl groups is the same.

[0957] The following are specific examples of groups represented by formula (a1), but the invention is not limited to these. In the following structural formulas, Me represents methyl, Et represents ethyl, and * represents a bonding site.

[0958] [Chemical Formula 63]

[0959]

[0960] In equations (a2) to (a4), as R W2 ~R W4 Specific examples of the alkylene group include methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, n-pentylene, isopentylene, n-hexylene, isohexylene, n-octylene, n-dodecylene, etc., preferably ethylene, n-propylene, isopropylene or n-butylene, and especially preferably ethylene or n-propylene.

[0961] In equation (a3), there are two M values ​​that can be the same or different.

[0962] In formulas (a2) to (a4), examples of ononium groups represented by M include ammonium, iodonium, phosphonium, and sulfonium groups.

[0963] CO2M in formula (a2), PO3M2 in formula (a2), and SO3M in formula (a4) can all have anionic structures with M dissociation. The counter cation of the anionic structure can be A1. + It can also be R in Equation 1-1 1 -L can contain cations.

[0964] Among the groups represented by formulas (a1) to (a4), groups represented by formulas (a1), (a2), or (a4) are preferred.

[0965] n in Equation 1-1 11 and n 12 Preferably, they are the same, and all are preferably integers from 1 to 5, more preferably integers from 1 to 3, even more preferably 1 or 2, and especially preferably 2.

[0966] In Formula 1-1, A1 and A2 independently represent oxygen, sulfur, or nitrogen atoms, with nitrogen atoms being preferred.

[0967] In Formula 1-1, A1 and A2 are preferably the same atoms.

[0968] In Equation 1-1, Za represents the counter ion that neutralizes the charge.

[0969] If R 11 ~R 18 and R 1 If all -L groups are electrically neutral, then Za becomes a monovalent counter anion. However, R 11 ~R 18 and R 1 -L can have anionic or cationic structures, for example, in R 11 ~R 18 and R 1 When -L has more than two anionic structures, Za can also become a counter cation.

[0970] Furthermore, if the anthocyanin represented by Formula 1-1 has an electroneutrally neutral structure in the compound as a whole, excluding Za, then Za is not required.

[0971] When Za is the counter anion, examples include sulfonate ions, carboxylate ions, tetrafluoroborate ions, hexafluorophosphate ions, p-toluenesulfonate ions, and perchlorate ions, with tetrafluoroborate ions being preferred.

[0972] When Za is the counter cation, examples include alkali metal ions, alkaline earth metal ions, ammonium ions, pyridonium ions, and sulfonium ions, with sodium ions, potassium ions, ammonium ions, pyridonium ions, or sulfonium ions being preferred, and sodium ions, potassium ions, or ammonium ions being even more preferred.

[0973] From the viewpoint of improving the visual recognizability of the exposed part, compounds represented by the following formulas 1-2 (i.e., anthocyanins) are more preferred as decomposable compounds.

[0974] [Chemical Formula 64]

[0975]

[0976] In Equation 1-2, R 1 R represents any one of the groups represented by formulas 2 to 4 above. 19 ~R 22 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -CN, -SR c or -NR d R e R 23 and R 24 Each can be used independently to represent a hydrogen atom or -R. a R a ~R e Each independently represents a hydrocarbon group, R 19 With R 20 R 21 With R 22 Or R 23 With R 24 They can be linked to form single or multiple rings, where L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 R represents a hydrogen atom, alkyl group, or aryl group. d1 ~R d4 W 1 and W 2 Each of these can independently represent an alkyl group that may have substituents, and Za represents a counterion that neutralizes the charge.

[0977] R in Equation 1-2 1 R in Equation 1-1 1 The meanings are the same, and the preferred selection methods are also the same.

[0978] In equation 1-2, R 19 ~R 22 Each is independently preferred to be a hydrogen atom, a halogen atom, or -R. a -OR b Or -CN.

[0979] More specifically, R 19 and R 21 Preferably hydrogen atoms or -R a .

[0980] Furthermore, R 20 and R 22 Preferably hydrogen atoms, -R a -OR b Or -CN.

[0981] As a result of R 19 ~R 22 -R indicates a Preferably alkyl or alkenyl groups.

[0982] In R 19 ~R 22 All are -R a In the case of R, it is preferred 19 With R 20 and R 21 With R 22 They can be linked together to form single or multiple rings.

[0983] As R 19 With R 20 Or R 21 With R 22 Examples of rings formed by linkages include benzene rings and naphthalene rings.

[0984] In Equation 1-2, R is preferred. 23 With R 24 They can be linked together to form single or multiple rings.

[0985] As R 23 With R 24 The ring formed by the linkage can be a monocyclic or polycyclic ring. Specifically, examples of the formed rings include monocyclic rings such as cyclopentene ring, cyclopentadiene ring, cyclohexene ring, and cyclohexadiene ring, as well as polycyclic rings such as indene ring.

[0986] In equation 1-2, R d1 ~R d4 Preferably, it is an unsubstituted alkyl group. Furthermore, R is preferred. d1 ~R d4 They are all the same group.

[0987] Examples of unsubstituted alkyl groups include those with 1 to 4 carbon atoms, with methyl being preferred.

[0988] In Equation 1-2, from the viewpoint of improving the water solubility of the compound represented by Equation 1-2, W 1 and W 2 Each is preferably a substituted alkyl group, individually and independently.

[0989] As a result of W 1 and W 2 The substituted alkyl group can be any one of the groups represented by formulas (a1) to (a4) in formula 1-1, and the preferred method is also the same.

[0990] Furthermore, from the viewpoint of machine developability, W is preferred. 1 and W 2 Each is an alkyl group having a substituent, and is a group having at least -(OCH2CH2)-, sulfonyl, a salt of sulfonyl, carboxyl, or a salt of carboxyl.

[0991] Za represents a counterion that neutralizes the charge within a molecule.

[0992] If R 19 ~R 22 R 23 ~R 24 R d1 ~R d4 W 1 W 2 and R 1 If all -L groups are electrically neutral, then Za becomes a monovalent counter anion. However, R 19 ~R 22 R 23 ~R 24 R d1 ~R d4 W 1 W 2 and R 1 -L can have anionic or cationic structures, for example, in R 19 ~R 22 R 23 ~R 24 R d1 ~R d4 W 1 W 2 and R 1 When -L has two or more anionic structures, Za can also become a counter cation.

[0993] Furthermore, if the compound represented by Formula 1-2 has an electrically neutral structure in the whole of the compound except for Za, then Za is not required.

[0994] The examples of Za as a counter anion are the same as those of Za in Formula 1-1, and the preferred methods are also the same. Furthermore, the examples of Za as a counter cation are also the same as those of Za in Formula 1-1, and the preferred methods are also the same.

[0995] From the viewpoint of decomposability and color development, anthocyanins, as decomposable compounds, are further preferably compounds represented by any one of the following formulas 1-3 to 1-7.

[0996] In particular, from the viewpoint of decomposition and color development, compounds represented by any one of Formulas 1-3, 1-5 and 1-6 are preferred.

[0997] [Chemical Formula 65]

[0998]

[0999] In equations 1-3 to 1-7, R 1 R represents any one of the groups represented by formulas 2 to 4 above. 19 ~R 22 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -CN, -SR c or -NR d R e R 25 and R 26 Each can be used independently to represent a hydrogen atom, a halogen atom, or -R. a R a ~R e Each independently represents a hydrocarbon group, R 19 With R 20 R 21 With R 22 Or R 25 With R 26 They can be linked to form single or multiple rings, where L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 R represents a hydrogen atom, alkyl group, or aryl group. d1 ~R d4 W 1 and W 2 Each of these can independently represent an alkyl group that may have substituents, and Za represents a counterion that neutralizes the charge.

[1000] R in Equations 1-3 to 1-7 1 R 19 ~R 22 R d1 ~R d4 W 1 W 2 and L and R in Equation 1-2 1 R 19 ~R 22 R d1 ~R d4 W 1 W 2The meanings of L and L are the same, and the preferred selection methods are also the same.

[1001] R in Equation 1-7 25 and R 26 Each atom is preferably a hydrogen atom or an alkyl group, more preferably an alkyl group, and especially preferably a methyl group.

[1002] The following are specific examples of anthocyanins that are decomposable compounds, but the present invention is not limited to these.

[1003] [Chemical Formula 66]

[1004]

[1005] Furthermore, the anthocyanin, as a decomposable compound, is preferably an infrared-absorbing compound as described in International Publication No. 2019 / 219560.

[1006] Furthermore, the aforementioned color-changing compounds may contain acid color-developing agents.

[1007] As an acid developer, an acid developer that is recorded as an acid developer in an image recording layer can be used, and the preferred method is also the same.

[1008] Color-changing compounds can be used alone or in combination with two or more components.

[1009] As a chromogenic compound, it can be used in combination with the decomposition compounds already described and the acid-producing agents described later.

[1010] From the viewpoint of color development, the content of the color-changing compound in the protective layer is preferably 0.10% to 50% by mass, more preferably 0.50% to 30% by mass, and even more preferably 1.0% to 20% by mass, relative to the total mass of the protective layer.

[1011] From the perspective of color development, the content M of the aforementioned color-changing compound in the above-mentioned protective layer X The content M of the infrared absorber in the image recording layer described above Y The ratio of M X / M Y Preferably, it is 0.1 or more, more preferably 0.2 or more, and especially preferably 0.3 or more and 3.0 or less.

[1012] -Water-soluble polymer-

[1013] From the viewpoint of developability (more preferably machine developability), the above-mentioned protective layer preferably contains a water-soluble polymer.

[1014] In this invention, a water-soluble polymer refers to a polymer that dissolves more than 1g in 100g of pure water at 70°C, and does not precipitate even when the solution obtained by dissolving 1g of the polymer in 100g of pure water at 70°C is cooled to 25°C.

[1015] Examples of water-soluble polymers used in the protective layer include polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, water-soluble cellulose derivatives, polyethylene glycol, and poly(meth)acrylonitrile.

[1016] As a modified polyvinyl alcohol, acid-modified polyvinyl alcohol having carboxyl or sulfonyl groups is preferred. Specifically, the modified polyvinyl alcohols described in Japanese Patent Application Publication Nos. 2005-250216 and 2006-259137 can be cited as examples.

[1017] Polyvinyl alcohol is a preferred example of the aforementioned water-soluble polymer. More preferably, polyvinyl alcohol with a saponification degree of 50% or higher is used.

[1018] The aforementioned degree of saponification is preferably 60% or higher, more preferably 70% or higher, and even more preferably 85% or higher. There is no particular upper limit to the degree of saponification; it can be below 100%.

[1019] The above-mentioned degree of saponification can be determined according to the method described in JIS K 6726:1994.

[1020] Polyvinylpyrrolidone is a preferred example of the aforementioned water-soluble polymer.

[1021] As a water-soluble polymer, polyvinyl alcohol and polyvinylpyrrolidone are also preferably used in combination.

[1022] Water-soluble polymers can be used alone or in combination of two or more.

[1023] When the protective layer contains a water-soluble polymer, the content of the water-soluble polymer relative to the total mass of the protective layer is preferably 1% to 99% by mass, more preferably 3% to 97% by mass, and even more preferably 5% to 95% by mass.

[1024] -Other ingredients-

[1025] In addition to the chromogenic compounds and water-soluble polymers already described, the aforementioned protective layer may also contain other components such as hydrophobic polymers, sensitizers, acid-producing agents, and infrared absorbers.

[1026] The other ingredients are described below.

[1027] [Hydrophobic polymers]

[1028] The aforementioned protective layer preferably comprises a hydrophobic polymer.

[1029] Hydrophobic polymers are polymers that dissolve less than 1g or are insoluble in 100g of pure water at 70°C.

[1030] Examples of hydrophobic polymers include polyethylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, alkyl poly(meth)acrylates (e.g., poly(methyl)acrylate, poly(ethyl)acrylate, poly(butyl)acrylate, etc.), and copolymers obtained by combining the raw material monomers of these polymers.

[1031] Furthermore, as a hydrophobic polymer, polyvinylidene chloride resin is preferred.

[1032] Furthermore, as a hydrophobic polymer, it is preferable to include a styrene-propylene copolymer.

[1033] Furthermore, from the viewpoint of machine developability, hydrophobic polymers are preferably hydrophobic polymer particles.

[1034] Hydrophobic polymers can be used alone or in combination of two or more.

[1035] When the protective layer contains a hydrophobic polymer, the content of the hydrophobic polymer is preferably 1% to 80% by mass, more preferably 5% to 50% by mass, relative to the total mass of the protective layer.

[1036] [Sensitizer]

[1037] From the viewpoint of ink adhesion, the above-mentioned protective layer preferably contains a sensitizer.

[1038] As the sensitizer used in the above-mentioned protective layer, the sensitizer described in the above-mentioned image recording layer can be used, and the preferred method is also the same.

[1039] Sensitizers can be used alone or in combination of two or more.

[1040] When the protective layer contains a sensitizer, the content of the sensitizer is preferably 0.5% to 30% by mass, more preferably 1% to 20% by mass, relative to the total mass of the protective layer.

[1041] [Acid-producing agent]

[1042] When the above-mentioned protective layer uses an acid color-developing agent as a color-changing compound, it is preferable to include an acid-generating agent.

[1043] The "acid-producing agent" in this invention refers to a compound that generates acid using light or heat. Specifically, it refers to a compound that generates acid by decomposing through infrared exposure.

[1044] The acid produced is preferably a strong acid with a pKa of 2 or less, such as sulfonic acid or hydrochloric acid. The acid produced by the acid-generating agent can change the color of the described acid colorimetric reagent.

[1045] Specifically, from the viewpoint of sensitivity and stability, onium salt compounds are preferred as acid-producing agents.

[1046] Specific examples of onium salts preferred as acid-producing agents include the compounds described in paragraphs 0121 to 0124 of International Publication No. 2016 / 047392.

[1047] Among them, triarylsulfonium or diaryliodosulfonium, sulfonates, carboxylates, and BPh4 are preferred. - BF4 - PF6 - ClO4 - etc. Here, Ph represents phenyl.

[1048] Acid-producing agents can be used alone or in combination of two or more.

[1049] When the protective layer contains an acid-generating agent, the content of the acid-generating agent is preferably 0.5% to 30% by mass, more preferably 1% to 20% by mass, relative to the total mass of the protective layer.

[1050] In addition to the components already described, the aforementioned protective layer may also contain known additives such as inorganic layered compounds and surfactants.

[1051] The protective layer is formed by applying and drying using known methods.

[1052] The coating weight (solid content) of the protective layer is preferably 0.01 g / m². 2 ~10g / m 2 More preferably 0.02 g / m 2 ~3g / m 2 Especially preferred is 0.1g / m 2 ~2.0g / m 2 .

[1053] The thickness of the protective layer is preferably 0.1 μm to 5.0 μm, more preferably 0.3 μm to 4.0 μm.

[1054] The thickness of the protective layer is preferably 0.1 to 5.0 times, more preferably 0.2 to 3.0 times, relative to the thickness of the image recording layer described later.

[1055] The protective layer may contain known additives such as plasticizers for imparting flexibility, surfactants for improving coatability, and inorganic particles for controlling surface lubricity.

[1056] (Methods for making offset printing plates and offset printing methods)

[1057] A lithographic printing plate can be produced by exposing an image to the original lithographic printing plate involved in this invention and performing a developing process.

[1058] The method for manufacturing the lithographic printing plate according to the present invention preferably includes: a step of exposing the original lithographic printing plate according to the present invention in an image form (hereinafter also referred to as the "exposure step"); and a step of supplying at least one of the group consisting of printing ink and dampening solution to remove the non-image portion of the image layer on a printing press (hereinafter also referred to as the "on-machine development step").

[1059] The offset printing method of the present invention preferably includes: a step of exposing the offset printing plate of the present invention in an image form (exposure step); a step of producing an offset printing plate by supplying at least one of the group consisting of printing ink and dampening solution to remove the non-image portion of the image recording layer on a printing press (on-machine development step); and a step of printing using the obtained offset printing plate (printing step).

[1060] The preferred embodiments of each step in the following description are provided regarding the method for manufacturing the lithographic printing plate and the lithographic printing method involved in this invention. Furthermore, the original lithographic printing plate involved in this invention can also be developed using a developing solution.

[1061] The following describes the exposure and on-machine development processes in the method for making a lithographic printing plate. However, the exposure process in the method for making a lithographic printing plate of the present invention is the same as the exposure process in the lithographic printing method of the present invention, and the on-machine development process in the method for making a lithographic printing plate of the present invention is the same as the on-machine development process in the lithographic printing method of the present invention.

[1062] Furthermore, it is inferred that during on-machine development, a portion of the outermost layer is removed, while a portion remains on the surface of the image section or penetrates into the interior of the image section through the printing ink.

[1063] <Exposure Process>

[1064] The method for manufacturing the lithographic printing plate according to the present invention preferably includes an exposure step of exposing the original lithographic printing plate according to the present invention in an image-like manner to form an exposed portion and an unexposed portion. The original lithographic printing plate according to the present invention is preferably exposed in an image-like manner by laser exposure using a transparent original image having line images, halftone images, etc., or by laser beam scanning based on digital data.

[1065] A light source with a wavelength of 750 nm to 1,400 nm is preferred. Solid-state lasers and semiconductor lasers that radiate infrared radiation are preferred as light sources with wavelengths of 750 nm to 1,400 nm. Regarding infrared lasers, the output power is preferably 100 mW or higher, the exposure time per pixel is preferably less than 20 microseconds, and the irradiation energy is preferably 10 mJ / cm². 2 ~300mJ / cm 2 Furthermore, to shorten the exposure time, a multi-beam laser device is preferred. The exposure mechanism can be any of the following: internal drum type, external drum type, or flat plate type.

[1066] Regarding image exposure, it can be performed using conventional methods such as plate-making machines. In the case of in-press development, image exposure can be performed on the printing press after the original lithographic printing plate is mounted on the press.

[1067] <On-machine developing process>

[1068] The method for manufacturing a lithographic printing plate according to the present invention preferably includes an on-machine development step of supplying at least one of the group consisting of printing ink and dampening solution to remove the image recording layer of the non-image portion on a printing press.

[1069] The following is an explanation of the on-machine development method.

[1070] [In-machine development method]

[1071] In the on-machine development method, the original lithographic printing plate exposed by the image is preferably made by supplying oil-based ink and water-based components to the printing press and removing the image recording layer of the non-image area to create the lithographic printing plate.

[1072] That is, if the lithographic printing plate is directly mounted on the printing press after image exposure without any development treatment, or if the lithographic printing plate is mounted on the printing press and then image exposure is performed on the printing press, followed by the supply of oil-based ink and water-based components for printing, then in the initial stage of printing, in the non-image section, the uncured image recording layer, due to the supply of either or both of the oil-based ink and water-based components, is dissolved or dispersed and removed, thereby exposing the hydrophilic surface to that area. On the other hand, in the exposure section, the image recording layer cured by exposure forms an oil-based ink receiving section with an oleophilic surface. The compound initially supplied to the plate can be either oil-based ink or water-based components, but from the perspective of preventing contamination of the image recording layer due to the removal of water-based components, it is preferable to initially supply oil-based ink. In this way, the lithographic printing plate is developed on the printing press and directly used in multi-sheet printing. As for oil-based inks and water-based components, conventional offset printing inks and dampening solutions are preferred.

[1073] For the laser used to expose the image of the lithographic printing plate original according to the present invention, the wavelength of the light source is preferably 300nm to 450nm or 750nm to 1,400nm. When using a light source with a wavelength of 300nm to 450nm, it is preferable to use a lithographic printing plate original containing sensitizing pigments with high absorption in that wavelength region in the image recording layer. For a light source with a wavelength of 750nm to 1,400nm, the aforementioned light sources are preferred. As for a light source with a wavelength of 300nm to 450nm, a semiconductor laser is preferred.

[1074] <Developing process with developer>

[1075] The method for manufacturing the lithographic printing plate involved in this invention can be as follows, comprising: a step of exposing the original lithographic printing plate involved in this invention in an image state; and a step of using a developing solution to remove the image recording layer of the non-image area to manufacture the lithographic printing plate (also referred to as the "developing solution development step").

[1076] Furthermore, the lithographic printing method involved in this invention can be the following steps, including: exposing the original lithographic printing plate involved in this invention in an image-like manner; using a developing solution to remove the image recording layer of the non-image area to create the lithographic printing plate; and using the obtained lithographic printing plate for printing.

[1077] As a developer, a known developer can be used.

[1078] There are no particular limitations on the pH of the developer; it can be a strongly alkaline developer, but a developer with a pH of 2 to 11 is preferred. For example, a developer containing at least one of a surfactant and a water-soluble polymer is preferred as a developer with a pH of 2 to 11.

[1079] In the development process using a strongly alkaline developer, the following method can be used: the protective layer is removed by a pre-washing step, followed by alkaline development, the alkalinity is removed by a post-washing step, the adhesive solution is treated, and the product is dried by a drying step.

[1080] Furthermore, when using the aforementioned developer containing surfactants or water-soluble polymers, the developing-resin treatment can be performed simultaneously. Therefore, a post-rinsing step is particularly unnecessary; after developing and resin treatment with a single solution, a drying step can be performed. Moreover, since the removal of the protective layer can also be performed simultaneously with developing and resin treatment, a separate pre-rinsing step is unnecessary. Preferably, after developing, residual developer is removed using a squeeze roller or the like, followed by drying.

[1081] <Printing Process>

[1082] The lithographic printing method involved in this invention includes a printing process of supplying printing ink to a lithographic printing plate and printing a recording medium.

[1083] There are no particular restrictions on the type of printing ink, and various known inks can be used as needed. However, oil-based inks or ultraviolet-curing inks (UV inks) are preferred as printing inks.

[1084] Furthermore, dampening solution can be supplied as needed during the aforementioned printing process.

[1085] Furthermore, the printing process described above does not require stopping the printing press and can be carried out continuously during the on-machine developing process or the developing process with the developing solution.

[1086] As a recording medium, there are no particular restrictions, and any known recording medium can be used as needed.

[1087] In the method for producing a lithographic printing plate from the lithographic printing plate master according to the present invention, and in the lithographic printing method according to the present invention, the entire surface of the lithographic printing plate master can be heated as needed before exposure, during exposure, and during the exposure to development period. This heating promotes the image formation reaction in the image recording layer, resulting in advantages such as improved sensitivity or print durability, and stabilized sensitivity. Regarding heating before development, it is preferable to perform the heating under mild conditions below 150°C. This prevents problems such as curing of non-image areas. For heating after development, it is preferable to use stronger conditions than described above, preferably within the range of 100°C to 500°C. Within this range, sufficient image enhancement can be obtained, and problems such as deterioration of the support and pyrolysis of the image area can be suppressed.

[1088] Example

[1089] The present invention will be described in detail below through embodiments, but the present invention is not limited thereto. In addition, in this embodiment, the terms "%" and "parts" refer to "mass %" and "mass parts" respectively unless otherwise specified.

[1090] <Synthesis of polymers P1 to P9>

[1091] A mixed solution of 4.7 parts by mass of polyisocyanates (all manufactured by Mitsui Chemicals, Inc.) listed in Table 1, 0.02 parts by mass of tert-butylbenzoquinone (all manufactured by TOAGOSEI CO., LTD.) with an NCO value of 1:1 to the hydroxyl value of the polyisocyanates, and 11.5 parts by mass of methyl ethyl ketone was heated to 65°C. 0.11 parts by mass of NEOSTANN U-600 (bismuth-based polycondensation catalyst, manufactured by NITTOH CHEMICAL CO., LTD.) was added to the reaction solution, and the mixture was heated at the same temperature for 4 hours. The reaction solution was cooled to room temperature (25°C), and methyl ethyl ketone was added, thereby synthesizing a 50% by mass urethane acrylate solution.

[1092] Next, molecular weight fractionation of the urethane acrylate solution was performed in a reusable GPC (equipment: LC908-C60, columns: JAIGEL-1H-40 and 2H-40 (manufactured by Japan Analytical Industry)) using tetrahydrofuran (THF) eluent. Then, P1 to P9, as shown in Table 1, were obtained respectively.

[1093] <Determination of weight-average molecular weight (Mw) and olefin unsaturated bond value (C=C value)>

[1094] The weight-average molecular weight (Mw) of the compound was determined using the following equipment and methods.

[1095] GPC measurement equipment: TOSOH HLC-8320GPC, GPC mobile phase: THF

[1096] Inspection device: Differential refractive index detector (RI), flow rate: 0.35 mL / min

[1097] Columns: Connect TSKgel SuperHZM-M, TSKgel SuperHZ4000, TSKgel SuperHZ3000 and TSKgel SuperHZ2000 for use.

[1098] Column temperature: 40℃

[1099] Standard sample used for molecular weight calibration curve: polystyrene (PS)

[1100] Furthermore, regarding the olefinic unsaturated bond value (C=C value) of the compound, through... 1 H-NMR measurements were used to analyze the (model) structure of the compound, and calculations were performed.

[1101] P13: A star-shaped polymer with the following structure, wherein the composition of the polymer chain shown below, in terms of the monomer molar ratio, is a / b / c=33 / 42 / 25.

[1102] P14: The composition of the star-shaped polymer with the following structure and the polymer chain shown below, in terms of the monomer polymerization molar ratio, is a / b / c=4.7 / 46.8 / 48.5.

[1103] [Chemical Formula 67]

[1104]

[1105] [Table 1]

[1106]

[1107] <Fabrication of the Support Body>

[1108] Aluminum alloy sheet of material 1S with a thickness of 0.3 mm was subjected to mechanical roughening treatment (brushing method) as described in paragraph 0126 of Japanese Patent Application Publication No. 2012-158022, and decontamination treatment in acidic aqueous solution as described in paragraph 0134.

[1109] Next, by appropriately adjusting the processing conditions from the first stage of anodizing treatment (Aj) as described in paragraph 0135 of Japanese Patent Application Publication No. 2012-158022 to the third stage of anodizing treatment (Am) as described in paragraph 0138, an anodized film is formed, thereby obtaining an aluminum support A. The anodized film has a large-diameter hole with an average diameter of 35 nm and a depth of 100 nm and a small-diameter hole with an average diameter of 10 nm and a depth of 1,000 nm. The ratio of the depth of the large-diameter hole to the average diameter of the large-diameter hole is 2.9.

[1110] In addition, a water washing process is performed between all processing steps, and the liquid is drained by rollers after the water washing process.

[1111] <The Formation of the Original Lithography Plate>

[1112] On the aforementioned support A (printed side), the dry coating amount is 87 mg / m². 2 The primer coating is formed by applying the primer coating liquid with the following composition in a certain manner.

[1113] The following image recording layer coating solution (1) was applied to the base layer and dried at 120°C for 40 seconds to form a dry coating weight of 0.971 g / m². 2 The image recording layer was used to obtain the original lithographic printing plate.

[1114] In addition, regarding the preparation of the image recording layer coating solution (1) containing polymer particles (microgels), it was prepared by mixing and stirring a photosensitive liquid containing components other than the microgel liquid described below before coating.

[1115] <Coating liquid for primer>

[1116] • Compound for primer coating (P-1): 0.1370 parts

[1117] • Sodium gluconate: 0.0700 parts

[1118] • Surfactant (EMALEX 710, manufactured by NIHON EMULSION Co., Ltd.): 0.00159 parts by weight

[1119] • Preservative (manufactured by Biohope L, K•I Chemical Industry Co.,LTD): 0.00149 parts

[1120] • Water: 329,000 portions

[1121] [Chemical Formula 68]

[1122]

[1123] <Image recording layer coating solution (1)>

[1124] •IR-1 (infrared absorber, the following compound): 0.01970 parts

[1125] • Color developer (S-15): 0.02000 parts

[1126] • IA-1 (electron-accepting polymerization initiator, compound below) 0.11000 parts

[1127] • Borate compounds (sodium tetraphenylborate, an electron-donating polymerization initiator): Amounts listed in Table 2

[1128] • Polymer A listed in Table 2: Amounts listed in Table 2

[1129] • Polymer compound B listed in Table 2: Amounts listed in Table 2

[1130] • M-1 (polymeric compound C, hereinafter referred to as compound): 0.00244 parts

[1131] • Anionic surfactant (A-1, the following compound): Amounts listed in Table 2

[1132] • Fluorinated surfactant (W-1, the following compound): 0.00416 parts

[1133] • 2-Butanone: 4.92 parts

[1134] • 1-Methoxy-2-propanol: 3.10 parts

[1135] • Methanol: 2.79 parts

[1136] • Microgel solution: 2.32 parts

[1137] [Infrared absorber]

[1138] IR-1: Compounds with the following structures, HOMO = -5.35 eV, LUMO = -3.73 eV, and Ph represents phenyl.

[1139] [Chemical Formula 69]

[1140]

[1141] Color developer (S-15): The following compounds

[1142] [Chemical Formula 70]

[1143]

[1144] Electron-receiving polymerization initiators

[1145] IA-1: Compounds with the following structure, LUMO = -3.02 eV, and Me represents methyl.

[1146] [Chemical Formula 71]

[1147]

[1148] [Polymerizing compound C]

[1149] M-1: Dipentaerythritol hexaacrylate, ARONIX M-403 (50-60%), manufactured by TOAGOSEI CO., LTD.

[1150] [surfactants]

[1151] Anionic surfactant (A-1): The following compounds

[1152] Fluorinated surfactants (W-1): The following compounds

[1153] [Chemical Formula 72]

[1154]

[1155] [Chemical Formula 73]

[1156]

[1157] <Preparation of Microgel Solution>

[1158] • Microgel (polymer particles): 2,640 parts

[1159] • Distilled water: 2.425 parts

[1160] The following shows the preparation method of the microgel used in the above microgel solution.

[1161] Preparation of polyisocyanate compounds-

[1162] A suspension of 17.78 parts (80 molar equivalents) of isophorone diisocyanate and 7.35 parts (20 molar equivalents) of the following polyphenol compound (1) in ethyl acetate (25.31 parts) was stirred with 0.043 parts of tris(2-ethylhexanoate) bismuth (NEOSTANN U-600, manufactured by NITTO KASEI CO.,LTD.). The reaction temperature was set at 50°C when the heating was suppressed, and the mixture was stirred for 3 hours to obtain an ethyl acetate solution (50% by mass) of the polyvalent isocyanate compound (1).

[1163] [Chemical Formula 74]

[1164]

[1165] -Preparation of microgels-

[1166] The oil and aqueous phases were mixed and emulsified at 12,000 rpm for 10 minutes using a homogenizer. The resulting emulsion was stirred at 45°C for 4 hours, and then 5.20 g of a 10% by mass aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-en-octanoate (U-CAT SA102, manufactured by San-Apro Ltd.) was added. The mixture was stirred at room temperature for 30 minutes and then allowed to stand at 45°C for 24 hours. The concentration of the solids was adjusted to 20% by mass with distilled water to obtain an aqueous dispersion of microgel (1). The average particle size was 0.28 μm when determined by light scattering.

[1167] ~Oil phase ingredients~

[1168] (Component 1) Ethyl acetate: 12.0 parts

[1169] (Component 2) An adduct (50% by mass ethyl acetate solution, manufactured by Mitsui Chemicals, Inc.) formed by adding trimethylolpropane (6 molar equivalents) and xylene diisocyanate (18 molar equivalents) to it, followed by the addition of monoterminated methylated polyoxyethylene (1 molar equivalent, number of repeats of oxyethylidene units: 90): 3.76 parts

[1170] (Component 3) Polyisocyanate compound (1) (as a 50% by mass ethyl acetate solution): 15.0 parts

[1171] (Component 4) 11.54 parts of 65% by weight ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartamer Company, Inc.)

[1172] (Component 5) 4.42 parts of a 10% ethyl acetate solution of a sulfonate surfactant (PIONIN A-41-C, manufactured by TAKEMOTO OIL & FAT CO.,LTD).

[1173] ~Aqueous phase components~

[1174] Distilled water: 46.87 parts

[1175] <Evaluation>

[1176] (1) Durability of UV-curable ink printing (UV printing durability)

[1177] Using a Kodak Magnus800 Quantum equipped with an infrared semiconductor laser, the original lithographic printing plate produced in the above manner was exposed under the following conditions: output power 27W, external drum speed 450rpm, and resolution 2,400dpi (dots per inch, 1 inch is 2.54cm). (Equivalent to irradiation energy 110mJ / cm²) 2 The exposed image includes a solid image and an amplitude modulation screen with 10% dots.

[1178] The obtained exposed original was mounted on the cylinder of a Heidelberger Druckmaschinen AG printing press SX-74 (chrysanthemum size) without development. A 100L dampening solution circulation tank with a built-in nonwoven filter and temperature control was connected to the printing press. 80L of 2.0% dampening solution S-Z1 (manufactured by Fujifilm Corporation) was loaded into the circulation tank, 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 ink through a standard automatic printing start-up method, 500 sheets were printed at a printing speed of 10,000 sheets per hour on TOKUBISHI coated paper (continuous yield: 76.5kg, manufactured by Mitsubishi Paper Mills Limited).

[1179] Next, printing continued. As the number of prints increased, the image area gradually wore down, resulting in a decrease in ink concentration on the printed material. Print durability was evaluated by determining the number of prints at which the dot area ratio of 10% halftone dots in the printed material, measured using a Gretag density meter (manufactured by Gretag Macbeth), decreased by 3% compared to the measurement on the 500th print. Relative print durability was evaluated using the following criteria, with 50,000 prints set as 100. Higher values ​​indicate better print durability. The evaluation results are recorded in Table 2.

[1180] Relative print durability = (Number of prints of the original offset printing plate) / 50,000 × 100

[1181] -Evaluation Criteria-

[1182] A: The relative print durability value exceeds 90.

[1183] B: Relative print durability value exceeding 75 and below 90

[1184] C: Relative print durability value below 75

[1185] (2) UV plate wear inhibition

[1186] Using a Kodak Magnus800 Quantum equipped with an infrared semiconductor laser, the original lithographic printing plate produced in the above manner was exposed under the following conditions: output power 27W, external drum speed 450rpm, and resolution 2,400dpi (dots per inch, 1 inch is 2.54cm). (Equivalent to irradiation energy 110mJ / cm²) 2 The exposed image includes a solid image and an amplitude-modulated screened image with 3% dots.

[1187] A 0.4mm diameter piano wire (manufactured by ESCO Co., Ltd.) was attached to the halftone dots of the obtained exposed master plate in a direction perpendicular to the rotation direction of the printing cylinder. Without development, it was mounted on the cylinder of a Heidelberger Druckmaschinen AG printing press (chrysanthemum size). A 100L dampening solution circulation tank with a built-in nonwoven filter and temperature control device was connected to the printing press. 80L of 2.0% dampening solution S-Z1 (manufactured by Fujifilm Corporation) was loaded into the circulation tank. Using T&K UV OFS K-HS ink GE-M (manufactured by T&KTOKA Corporation) as the printing ink, after supplying the dampening solution and ink via a standard automatic printing start-up method, printing was performed on TOKUBISHI coated paper (manufactured by Mitsubishi Paper Mills Limited, continuous yield: 76.5kg) at a printing speed of 10,000 sheets per hour.

[1188] When 2,000 sheets were printed, the piano wire was removed from the printing plate, and the plate was reset on the printing press to begin printing again. After restarting printing, the 100th print was checked, and the image area corresponding to the position of the piano wire was examined visually using a 50x magnifying glass to check for any ink defects. Similarly, this check was performed every 2,000 sheets, and the evaluation ended at the stage where ink defects occurred. The evaluation results are recorded in Table 2.

[1189] -Evaluation Criteria-

[1190] A: The number of printed sheets until “plate wear” occurs in the lithographic printing plate is more than 20,000.

[1191] B: The number of printed sheets until “plate wear” occurs in the lithographic printing plate is more than 4,000 but less than 20,000.

[1192] C: The number of printed sheets until “plate wear” occurs in the lithographic printing plate is less than 4,000.

[1193] [Table 2]

[1194]

[1195] According to the results recorded in Table 2, the lithographic printing plates of Examples 1 to 11, which are the original lithographic printing plates of the present invention, exhibit excellent printing durability even when using UV ink.

[1196] Furthermore, according to the results recorded in Table 2, the UV plate wear suppression properties of the original lithographic printing plates of Examples 1 to 11, which are the original lithographic printing plates involved in the present invention, are also excellent.

[1197] (Examples 12 to 22)

[1198] Before forming the image recording layer, it is performed in the same manner as in Example 11.

[1199] <Formation of the protective layer>

[1200] A protective coating solution containing the components listed in Table 4 was bar-coated onto the image recording layer (wherein the protective coating solution contains each component listed in Table 4, adjusted to a solid content of 20% by mass using ion-exchanged water), and dried at 120°C for 60 seconds, thereby forming a dry coating with a coating weight of 0.50 g / m². 2 The protective layer.

[1201] Through the above processes, the original offset printing plate was obtained.

[1202] <Evaluation of the original lithographed version>

[1203] UV plate wear inhibition and UV printing durability were evaluated in the same manner as described above.

[1204] [In-machine developability]

[1205] The exposed original, obtained in the same manner as the aforementioned UV plate wear evaluation, was mounted on the cylinder of a Heidelberger Druckmaschinen AG printing press SX-74 (636mm × 939mm) without development. A 100L dampening solution circulation tank with a built-in nonwoven filter and temperature control device was connected to the printing press. 80L of dampening solution S-Z1 (manufactured by Fujifilm Corporation) at 2.0% by mass was loaded into the circulation tank, and UV-curable ink, namely 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 ink through a standard automatic printing start-up method, printing was performed at a speed of 10,000 sheets per hour on 500 sheets of TOKUBISHI coated paper (continuous yield: 76.5kg, Mitsubishi Paper Mills Limited).

[1206] In printing, the number of sheets of paper required to prevent ink transfer to non-image areas is measured as in-machine developability. A lower number of sheets indicates better in-machine developability. The results are shown in Table 3.

[1207] Furthermore, for the obtained lithographic printing plate original, under ambient temperature (25°C) and humidity of 50%, an OSRAM FLR40SW fluorescent lamp manufactured by Mitsubishi Electric Corporation was used as the light source. The lithographic printing plate original was placed at an illuminance of 1000 lx in a pocket lux meter (ANA-F9 model) manufactured by TOKYOPHOTOELECTRIC CO.,LTD., and irradiated with white light for 2 hours. The developability of the irradiated lithographic printing plate was then measured in the same manner as described above. The results are shown in Table 3.

[1208] [Visual discernibility (color rendering): Measurement of the change in lightness ΔL before and after exposure]

[1209] The Luxel PLATESETTER T-9800, manufactured by FUJIFILM Graphic Systems Co., Ltd., equipped with an 830nm infrared semiconductor laser, achieved an energy density of 110mJ / cm² under the following conditions: 99.5% output, 220rpm outer drum speed, and 2,400dpi resolution (dots per inch, 1 inch = 25.4mm). 2 The original offset printing plate was exposed immediately after exposure and after being stored in the dark (25°C) for 24 hours following exposure. The exposure was performed at 25°C and 50% RH.

[1210] The brightness change of the original lithographic printing plate before and after exposure was measured. An eXact spectrophotometer manufactured by X-Rite Inc. was used in the measurements. L... * a * b * L in color scheme * The value (brightness) represents the L value of the image recording layer after exposure. * Value and L of the image recording layer before exposure * The absolute value of the difference is recorded as the brightness change ΔL. The larger the ΔL, the better the visual recognizability of the exposed area. The ΔL value obtained using the original lithographic printing plate immediately after exposure is recorded in the "ΔL (after)" column of Table 3. Furthermore, the ΔL value obtained using the original lithographic printing plate after 24 hours of storage is recorded in the "ΔL (after 24 hours)" column of Table 3.

[1211] [Scratch resistance (scratch stain inhibition)]

[1212] The original lithographic printing plate was exposed using a Luxel PLATESETTERT-6000III manufactured by Fujifilm Corporation, which is equipped with an infrared semiconductor laser, at an outer drum speed of 1,000 rpm (revolutions per minute), 70% laser output, and a resolution of 2,400 dpi (dots per inch). After exposure, scratches were applied to the obtained lithographic printing plate using a scratching tester at 25°C and 70% humidity.

[1213] The scratching tester used was a HEIDON scratching Intersity TESTER HEIDEN-18, employing sapphire needles with a diameter of 0.1 mm and a scratching load of 50 g. The plate was not developed after scratching, but instead mounted on the plate cylinder of a DAIYA IF2 printing press manufactured by Mitsubishi Heavy Industries, Ltd. A dampening solution of IF102 (manufactured by Fujifilm Corporation) / tap water = 3 / 97 (volume ratio) and Values-G(N) black ink (manufactured by DIC CORPORATION) were supplied using the standard automatic printing start-up method of the DAIYA IF2. After on-machine development, printing was performed at a speed of 10,000 sheets per hour on TOKUBISHI coated paper (continuous yield: 76.5 kg, manufactured by Mitsubishi Paper Mills Limited), and the extent to which the scratched areas became printing contaminants was evaluated. The results are shown in Table 3. Furthermore, regarding intermediate scores such as 9 and 7, these are considered intermediate scores when the evaluation standard is in the middle of the upper limit. The preferred evaluation standard is 6 to 10 points.

[1214] -Evaluation Criteria-

[1215] 10 points: The scratches applied will not become printing contamination.

[1216] 8 points: A small amount of printing contamination, indistinguishable to the naked eye, was observed at the area where the scratches were applied.

[1217] 6 points: A small amount of printing contamination was observed with the naked eye at the area where the scratches were applied.

[1218] 4 points: Printing contamination was observed with the naked eye at the area where the scratches were applied.

[1219] 2 points: Obvious printing contamination was observed at the area where the scratches were applied.

[1220] [Table 3]

[1221]

[1222] The following shows the details of the compounds listed in Table 3, in addition to those mentioned above.

[1223] [Color-changing compounds]

[1224] IR-1~IR-7: Compounds with the following structures

[1225] [Chemical Formula 75]

[1226]

[1227] [Chemical Formula 76]

[1228]

[1229] [Acid colorimetric reagent]

[1230] S-1: Compounds with the following structures

[1231] S-2: Compounds with the following structure

[1232] [Chemical Formula 77]

[1233]

[1234] [Water-soluble polymers]

[1235] PVA-1: Mowiol 4-88, Mowiol 4-88 (registered trademark) manufactured by Sigma Aldrich.

[1236] PVA-2: Mowiol 8-88, Mowiol (registered trademark) 8-88 manufactured by Sigma Aldrich.

[1237] WP-1: A compound with the following structure (polyvinylpyrrolidone, weight-average molecular weight 45,000).

[1238] [Chemical Formula 78]

[1239]

[1240] [Hydrophobic polymers]

[1241] P-1: A compound with the following structure (polyvinylidene chloride resin, weight average molecular weight 40,000).

[1242] P-2: A compound with the following structure (styrene-methyl acrylate copolymer, n=0.3, m=0.7, weight-average molecular weight 40,000).

[1243] [Chemical Formula 79]

[1244]

[1245] [Acid-producing agent]

[1246] Int-1: Compounds with the following structure, where Ph represents phenyl.

[1247] [Chemical Formula 80]

[1248]

[1249] [Sensitizer]

[1250] A-1: Compounds with the following structures

[1251] [Chemical Formula 81]

[1252]

[1253] According to the results recorded in Table 3, the lithographic printing plates of Examples 12 to 22, which are the original lithographic printing plates of the present invention, exhibit excellent printing durability even when using UV ink.

[1254] Furthermore, according to the results recorded in Table 3, the lithographic printing plates of Examples 12 to 22, which are the original lithographic printing plates involved in this invention, also exhibit excellent UV plate wear suppression, visual recognition (color development), visual recognition over time (color development over time), on-machine developability, on-machine on-machine developability, and scratch resistance.

[1255] The entire contents of the publications of Japanese Patent Application No. 2019-180621, filed on September 30, 2019, and Japanese Patent Application No. 2020-034237, filed on February 28, 2020, are incorporated herein by reference.

[1256] All documents, patent applications and technical standards described herein are incorporated herein by reference to the same extent as those specifically and separately described therein.

[1257] Symbol Explanation

[1258] 18-Aluminum plate, ta-Anode reaction time, tc-Cathode reaction time, tp-Time until current reaches peak value from 0, Ia-Current at peak value on the anode circulation side, Ic-Current at peak value on the cathode circulation side, AA-Current of anode reaction on aluminum plate, CA-Current of cathode reaction on aluminum plate, 10-Original plate for offset printing, 12a, 12b-Aluminum support, 14-Undercoating layer, 16-Image recording layer, 20a, 20b-Anodic oxide film, 22a, 22b-Micropores, 24-Large diameter hole, 26-Small diameter hole, D-Depth of large diameter hole, 50-Main electrolytic cell, 51-AC power supply, 52-Radial drum roller, 53a, 53b-Main electrode, 54-Electrolyte supply port, 55-Electrolyte, 56-Auxiliary anode, 60-Auxiliary anode tank, W-Aluminum plate, A1-Supply direction, A2-Electrolyte discharge direction.

Claims

1. A lithographic printing plate master, comprising a support and an image recording layer formed on said support, The image recording layer contains an infrared absorber, a polymerization initiator, and polymer A. The weight-average molecular weight of polymer A is greater than 15,000 but less than 150,000. The olefin unsaturated bond value of polymer A is 3.0 mmol / g or higher. The polymer A has a structure represented by the following formula (A-2), In equation (A-2), the wavy line represents the bonding position with other structures.

2. The original offset printing plate according to claim 1, wherein, The polymer A comprises a resin represented by the following formula (I), A P - (B P ) nP Equation (I) In formula (I), A P B represents an organic group with an nP valence that has hydrogen bonding. P This indicates a group having two or more polymerizable groups, where nP represents an integer greater than 2.

3. The original offset printing plate according to claim 1, wherein, The polymer A has at least one structure selected from the group consisting of an adduct structure, a biuret structure, and an isocyanurate structure.

4. The original offset printing plate according to claim 2, wherein, The B P The polymerizable group in it includes (meth)acryloyloxy.

5. The original offset printing plate according to claim 2, wherein, The B P It is a group having three or more (meth)acryloyloxy groups.

6. The original offset printing plate according to claim 1, wherein, The image recording layer contains two or more polymers A.

7. The original offset printing plate according to claim 1, wherein, The image recording layer also contains a polymeric compound B with a weight-average molecular weight of 1,000 or more and 15,000 or less.

8. The original offset printing plate according to claim 1, wherein, The image recording layer also contains a polymeric compound C with a molecular weight of less than 1000.

9. The original offset printing plate according to claim 1, wherein, The image recording layer is the outermost layer.

10. The original offset printing plate according to claim 1, wherein, The image recording layer also contains polymer particles.

11. The lithographic printing plate according to claim 10, wherein, The polymer particles have hydrophilic groups.

12. The lithographic printing plate according to claim 11, wherein, The hydrophilic group is a group represented by the following formula Z. *-QWY formula Z In formula Z, Q represents a divalent linking group, W represents a divalent group with a hydrophilic structure or a divalent group with a hydrophobic structure, Y represents a monovalent group with a hydrophilic structure or a monovalent group with a hydrophobic structure, either W or Y has a hydrophilic structure, and * represents the bonding site with other structures.

13. The lithographic printing plate original according to claim 12, wherein, The hydrophilic structure comprises a polyepoxide structure.

14. The lithographic printing plate according to claim 10, wherein, The polymer particles comprise building blocks formed from aromatic vinyl compounds.

15. The original offset printing plate according to claim 1, wherein, The polymerization initiator includes an electron-donating polymerization initiator.

16. The lithographic printing plate according to claim 15, wherein, The HOMO value of the infrared absorber is less than 0.70 eV, and the HOMO value of the electron-donating polymerization initiator is less than 0.70 eV.

17. The original lithographic printing plate according to claim 1, wherein, The image recording layer also contains a color developer.

18. The original lithographic printing plate according to claim 1, wherein, The support is an aluminum support, which has an aluminum plate and an anodized aluminum film disposed on the aluminum plate. The anodic oxide film is located closer to the image recording layer than the aluminum plate. The anodic oxide film has micropores extending along the depth direction from the surface of the image recording layer side. The average diameter of the micropores on the surface of the anodic oxide film is greater than 10 nm and less than 100 nm. L on the surface of the image recording layer side of the anodic oxide film * a * b * Lightness (L) in the color system * The value is 70-100.

19. The lithographic printing plate according to claim 18, wherein, The micropores consist 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 depth of 10 nm to 1000 nm. The small-diameter pore portion is connected to the bottom of the large-diameter pore portion and extends from the connection point to a depth of 20 nm to 2000 nm. The average diameter of the anodic oxide film surface in the large-diameter aperture is 15 nm to 100 nm. The average diameter at the connecting position of the small-diameter hole is less than 13 nm.

20. The original lithographic printing plate according to claim 1, wherein, The image recording layer has a protective layer containing a color-changing compound.

21. The lithographic printing plate according to claim 20, wherein, At 110mJ / cm 2 When the energy density is used for exposure to infrared light with a wavelength of 830 nm, the brightness change ΔL before and after the exposure is greater than 2.

0.

22. The lithographic printing plate according to claim 20, wherein, The color-changing compounds include compounds that develop color upon exposure to infrared light.

23. The lithographic printing plate according to claim 20, wherein, The color-changing compound includes decomposable compounds that decompose upon exposure to infrared light.

24. The lithographic printing plate according to claim 23, wherein, The color-changing compounds include decomposable compounds that decompose through thermal, electron migration, or both caused by infrared exposure.

25. The lithographic printing plate according to claim 20, wherein, The color-changing compound is anthocyanin.

26. The lithographic printing plate according to claim 20, wherein, The color-changing compound is a compound represented by the following formula 1-1. In Equation 1-1, R 1 R represents a group represented by any one of the following formulas 2 to 4. 11 ~R 18 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -SR c or -NR d R e R a ~R e Each of the following groups independently represents a hydrocarbon group: A1, A2, and multiple R groups. 11 ~R 18 The links can be chosen to form a single ring or multiple rings, where A1 and A2 independently represent oxygen, sulfur, or nitrogen atoms, respectively, and n 11 and n 12 Each of the integers from 0 to 5 can be represented independently, where n 11 and n 12 The total is 2 or more, n 13 and n 14 Each can be independently represented as 0 or 1, and L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 Represents a hydrogen atom, alkyl group, or aryl group; Za represents a counter ion that neutralizes the charge. In equations 2 to 4, R 20 R 30 R 41 and R 42 Each group independently represents an alkyl or aryl group, Zb represents a counterion that neutralizes the charge, and the wavy line represents the bonding site with the group represented by L in Formula 1-1.

27. The lithographic printing plate according to claim 20, wherein, The color-changing compound is a compound represented by the following formulas 1-2. In Equation 1-2, R 1 R represents a group represented by any one of the following formulas 2 to 4. 19 ~R 22 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -CN, -SR c or -NR d R e R 23 and R 24 Each can be used independently to represent a hydrogen atom or -R. a R a ~R e Each independently represents a hydrocarbon group, R 19 With R 20 R 21 With R 22 or R 23 With R 24 The links can be chosen to form a single or multiple rings, where L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 R represents a hydrogen atom, alkyl group, or aryl group. d1 ~R d4 W 1 and W 2 Each of these groups independently represents an alkyl group with optional substituents, and Za represents a counterion that neutralizes the charge. In equations 2 to 4, R 20 R 30 R 41 and R 42 Each alkyl or aryl group is represented independently, Zb represents a counterion that neutralizes the charge, and the wavy line represents the bonding site with the group represented by L in Formulas 1-2.

28. The lithographic printing plate according to claim 20, wherein, The chromogenic compound is a compound represented by any one of the following formulas 1-3 to 1-7. In equations 1-3 to 1-7, R 1 R represents a group represented by any one of the following formulas 2 to 4. 19 ~R 22 Each of the following can be used independently to represent a hydrogen atom, a halogen atom, and -R. a -OR b -CN, -SR c or -NR d R e R 25 and R 26 Each can be used independently to represent a hydrogen atom, a halogen atom, or -R. a R a ~R e Each independently represents a hydrocarbon group, R 19 With R 20 R 21 With R 22 or R 25 With R 26 The links can be chosen to form a single or multiple rings, where L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 R represents a hydrogen atom, alkyl group, or aryl group. d1 ~R d4 W 1 and W 2 Each of these groups independently represents an alkyl group with optional substituents, and Za represents a counterion that neutralizes the charge. In equations 2 to 4, R 20 R 30 R 41 and R 42 Each alkyl or aryl group is represented independently, Zb represents a counterion that neutralizes the charge, and the wavy line represents the bonding site with the group represented by L in Formulas 1-3 to 1-7.

29. The original lithographic printing plate according to claim 27 or 28, wherein, W in Equations 1-2 to 1-7 1 and W 2 Each is an alkyl group having a substituent, and is a group having at least -(OCH2CH2)-, sulfonyl, a salt of sulfonyl, carboxyl, or a salt of carboxyl.

30. The original lithographic printing plate according to claim 27 or 28, wherein, In Equations 1-2 to 1-7, L represents an oxygen atom.

31. The lithographic printing plate according to claim 20, wherein, The content M of the color-changing compound in the protective layer X The content M of the infrared absorber in the image recording layer Y The ratio of M X / M Y It is above 0.

2.

32. The lithographic printing plate according to claim 20, wherein, The protective layer contains a water-soluble polymer.

33. The lithographic printing plate original according to claim 32, wherein, The water-soluble polymer contains polyvinyl alcohol with a saponification degree of 50% or higher.

34. The lithographic printing plate according to claim 32, wherein, The water-soluble polymer contains polyvinylpyrrolidone.

35. The lithographic printing plate according to claim 32, wherein, The protective layer comprises a hydrophobic polymer.

36. The lithographic printing plate original according to claim 35, wherein, The hydrophobic polymer is hydrophobic polymer particles.

37. The lithographic printing plate according to claim 35, wherein, The hydrophobic polymer comprises polyvinylidene chloride resin.

38. The original lithographic printing plate according to claim 35, wherein, The hydrophobic polymer comprises a styrene-acrylic copolymer.

39. The lithographic printing plate according to claim 20, wherein, The protective layer contains a sensitizer.

40. The original lithographic printing plate according to any one of claims 20 to 28, 31 to 39, wherein, The amount of the protective layer is 0.1 g / m 2 ~2.0g / m 2 .

41. A method for producing a lithographic printing plate, comprising: The process of exposing the original lithographic printing plate as described in any one of claims 1 to 40 in an image-like manner; and A process of supplying at least one of the group consisting of printing ink and dampening solution to a printing press to remove the image recording layer that is not an image layer.

42. A method for offset printing, comprising: The process of exposing the original lithographic printing plate as described in any one of claims 1 to 40 in an image-like manner; The process of producing a lithographic printing plate by supplying at least one of the following components: printing ink and dampening solution, to a printing press to remove the image recording layer (excluding the image layer); and The process of printing using the obtained lithographic printing plate.

Images