Methods for making on-machine developing type lithographic printing plates, lithographic printing plates, and lithographic printing methods.

Abstract

This invention provides an in-machine developable lithographic printing plate master, and a method for manufacturing a lithographic printing plate or a lithographic printing method using the aforementioned in-machine developable lithographic printing plate master. The aforementioned in-machine developable lithographic printing plate master sequentially comprises a support, an image recording layer, and an outermost layer. The image recording layer comprises an infrared absorber, an electron-accepting polymerization initiator, and a polymerizable compound. The LUMO value of the electron-accepting polymerization initiator minus the LUMO value of the infrared absorber is 0.45 eV or higher. The outermost layer comprises a color-changing compound.

Description

Technical Field

[0001] This invention relates to an on-machine developing type lithographic printing plate master, a method for manufacturing lithographic printing plates, and a lithographic printing method. Background Technology

[0002] 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 property of water and oil-based inks. The oleophilic image area of ​​the lithographic printing plate serves as the ink receiving area, and 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.

[0003] 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 as the image area. This image recording layer is then removed by dissolving and removing any unnecessary image recording layers using an alkaline developer or organic solvent, thus exposing the surface of the hydrophilic support and forming a non-image area.

[0004] 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.

[0005] 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.

[0006] In this invention, the lithographic printing plate original that can be used for such on-machine development is referred to as an "on-machine developing type lithographic printing plate original".

[0007] As a previous lithographic printing original, for example, the lithographic printing original described in Patent Document 1 or Patent Document 2 can be cited.

[0008] Patent document 1 describes a negative lithographic printing plate original, wherein the top coating contains an infrared absorber having thermally decomposable groups.

[0009] Furthermore, Patent Document 2 describes a negative lithographic printing plate original, wherein a color developer is included in the top coating layer.

[0010] Patent Document 1: International Publication No. 2019 / 219560

[0011] Patent Document 2: U.S. Patent Application Publication No. 2010 / 0009130 Summary of the Invention

[0012] The technical problem to be solved by the invention

[0013] One embodiment of the present invention aims to solve the problem of providing an on-machine developing type lithographic printing plate with excellent stability over time.

[0014] Another embodiment of the present invention aims to solve the problem of providing a method for manufacturing a lithographic printing plate or a lithographic printing method using the above-described on-machine developing type lithographic printing plate original.

[0015] means for solving technical problems

[0016] The following methods are among the ways to solve the above problems.

[0017] <1> An on-machine developing type lithographic printing plate master has a support, an image recording layer and an outermost layer in sequence. The image recording layer contains an infrared absorber, an electron-accepting polymerization initiator and a polymerizable compound. The LUMO of the electron-accepting polymerization initiator minus the LUMO of the infrared absorber is 0.45 eV or higher. The outermost layer contains a color-changing compound.

[0018] <2> according to <1> The aforementioned in-machine developing type offset printing plate original, wherein,

[0019] The LUMO of the aforementioned electron-receiving polymerization initiator and the LUMO of the aforementioned infrared absorber are 0.62 eV or higher.

[0020] <3> according to <1> or <2> The aforementioned in-machine developing type offset printing plate original, wherein,

[0021] The LUMO of the above-mentioned infrared absorber is less than -3.80 eV.

[0022] <4> according to <1> to <3> The on-machine developable lithographic printing plate original as described in any one of the following:

[0023] The infrared absorber described above comprises a compound represented by the following formula 1.

[0024] [Chemical Formula 1]

[0025]

[0026] In Formula 1, R1 and R2 independently represent hydrogen atoms or alkyl groups, and R1 and R2 can be linked together to form a ring. R3 to R6 independently represent hydrogen atoms or alkyl groups, R7 and R8 independently represent alkyl or aryl groups, Y1 and Y2 independently represent oxygen atoms, sulfur atoms, -NR0- or dialkylmethylene groups, R0 represents hydrogen atoms, alkyl groups or aryl groups, Ar1 and Ar2 independently represent groups that form benzene or naphthalene rings that can have the groups represented by Formula 2 described later, and A1 represents -NR9R. 10 -X1-L1 or the group represented by Formula 2 as described later, R9 and R 10 Each of Ar1 and Ar2 independently represents an alkyl, aryl, alkoxycarbonyl, or arylsulfonyl group; X1 represents an oxygen atom or a sulfur atom; L1 represents a hydrocarbon group, a heteroaryl group, or a group whose bond with X1 is broken by heat or infrared exposure; Za represents a counterion that neutralizes the charge; and at least one of Ar1 and Ar2 has a group represented by the following formula 2.

[0027] -X Formula 2

[0028] In Equation 2, X represents a halogen atom, -C(=O)-X2-R 11 -C(=O)-NR 12 R 13 -OC(=O)-R 14 -CN, -SO2NR 15 R 16 Or perfluoroalkyl, X2 represents a single bond or oxygen atom, R 11 and R 14 Each can be independently represented by an alkyl or aryl group, R 12 、R 13 、R 15 and R 16 Each can be represented independently as a hydrogen atom, alkyl group, or aryl group.

[0029] <5> according to <4> The aforementioned in-machine developing type offset printing plate original, wherein,

[0030] At least one of Ar1 and Ar2 in Formula 1 has a halogen atom.

[0031] <6> according to <5> The aforementioned in-machine developing type offset printing plate original, wherein,

[0032] At least one of Ar1 and Ar2 in Formula 1 has a bromine atom.

[0033] <7> according to <1> to <6> The on-machine developable lithographic printing plate original as described in any one of the following:

[0034] The LUMO of the aforementioned electron-receiving polymerization initiators is greater than -3.2 eV.

[0035] <8> according to <1> to <7> The on-machine developable lithographic printing plate original as described in any one of the following:

[0036] The aforementioned electron-accepting polymerization initiator is an onium salt compound.

[0037] <9> according to <1> to <8> The on-machine developable lithographic printing plate original as described in any one of the following:

[0038] The aforementioned electron-receiving polymerization initiator comprises a compound represented by the following formula (II).

[0039] [Chemical Formula 2]

[0040]

[0041] In equation (II), X A R represents a halogen atom. A It represents an aryl group.

[0042] <10> according to <1> to <9> The on-machine developable lithographic printing plate original as described in any one of the following:

[0043] The aforementioned polymeric compounds include polymeric compounds with two or fewer functions.

[0044] <11> according to <1> to <10> The on-machine developable lithographic printing plate original as described in any one of the following:

[0045] The aforementioned image recording layer also contains polyvinyl acetal.

[0046] <12> according to <1> to <11> The on-machine developable lithographic printing plate original as described in any one of the following:

[0047] The outermost layer contains a hydrophobic polymer.

[0048] <13> according to <12> The aforementioned in-machine developing type offset printing plate original, wherein...

[0049] The aforementioned hydrophobic polymers are hydrophobic polymer particles.

[0050] <14> according to <1> to <13> The on-machine developable lithographic printing plate original as described in any one of the following:

[0051] 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.

[0052] <15> according to <1> to <14> The on-machine developable lithographic printing plate original as described in any one of the following:

[0053] The aforementioned color-changing compounds include those that develop color upon exposure to infrared light.

[0054] <16> according to <1> to <15> The on-machine developable lithographic printing plate original as described in any one of the following:

[0055] The aforementioned color-changing compounds include decomposable compounds that decompose upon exposure to infrared light.

[0056] <17> according to <1> to <15> The on-machine developable lithographic printing plate original as described in any one of the following:

[0057] The aforementioned color-changing compound is anthocyanin.

[0058] <18> according to <1> to <16> The on-machine developable lithographic printing plate original as described in any one of the following:

[0059] The aforementioned color-changing compounds are compounds represented by the following formula 1-1.

[0060] [Chemical Formula 3]

[0061]

[0062] In Equation 1-1, R 1 R represents a group represented by any one of the following formulas 2-1 to 4-1. 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 -N(R). 10 )-, R 10 Represents a hydrogen atom, alkyl group, or aryl group; Za represents a counter ion that neutralizes the charge.

[0063] [Chemical Formula 4]

[0064]

[0065] In equations 2-1 to 4-1, 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.

[0066] <19> according to <18> The aforementioned in-machine developing type offset printing plate original, wherein,

[0067] The aforementioned color-changing compounds are those represented by the following formulas 1-2.

[0068] [Chemical Formula 5]

[0069]

[0070] In Equation 1-2, R 1 R represents any one of the groups represented by formulas 2-1 to 4-1 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 Represent -R independently 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 -N (R 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.

[0071] <20> according to <18> or <19> The aforementioned in-machine developing type offset printing plate original, wherein,

[0072] The aforementioned color-changing compounds are compounds represented by any one of the following formulas 1-3 to 1-7.

[0073] [Chemical Formula 6]

[0074]

[0075] In equations 1-3 to 1-7, R 1 R represents any one of the groups represented by formulas 2-1 to 4-1 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 -N (R 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.

[0076] <21> according to <19> or <20> The aforementioned in-machine developing type offset printing plate original, wherein,

[0077] 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.

[0078] <22> according to <1> to <21> The on-machine developable lithographic printing plate original as described in any one of the following:

[0079] The aforementioned image recording layer also contains an electron-donating polymerization initiator.

[0080] <23> according to <22> The aforementioned in-machine developing type offset printing plate original, wherein,

[0081] The aforementioned electron-donating polymerization initiator is a borate compound.

[0082] <24> according to <22> or <23> The on-machine developing type lithographic printing plate original comprises a compound formed by forming a salt of a cation having the above-mentioned electron-accepting polymerization initiator structure and an anion having the above-mentioned electron-donating polymerization initiator structure, as the above-mentioned electron-accepting polymerization initiator and the above-mentioned electron-donating polymerization initiator.

[0083] <25> according to <22> to <24> The on-machine developable lithographic printing plate original as described in any one of the following:

[0084] The HOMO value of the above-mentioned infrared absorber and the HOMO value of the above-mentioned electron-donating polymerization initiator are below 0.70 eV.

[0085] <26> according to <1> to <25> The on-machine developable lithographic printing plate original as described in any one of the following:

[0086] The aforementioned polymeric compounds include polymeric compounds with seven or more functions.

[0087] <27> according to <1> to <26> The on-machine developable lithographic printing plate original as described in any one of the following:

[0088] The aforementioned polymeric compounds include polymeric compounds with 10 or more functions.

[0089] <28> according to <1> to <27> The on-machine developable lithographic printing plate original as described in any one of the following:

[0090] The aforementioned support has an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate. The anodic oxide film is located closer to the image recording layer side than the aluminum plate. The anodic oxide film has micropores extending from the surface of the image recording layer side along the depth direction. The average diameter of the micropores in the surface of the anodic oxide film is greater than 10 nm and less than 100 nm.

[0091] <29> according to <28> The aforementioned in-machine developing type offset printing plate original, wherein,

[0092] 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.

[0093] <30> A method for producing a lithographic printing plate, comprising: taking... <1> to <29> The process of exposing the on-machine developing type lithographic printing plate master as an image as described in any one of the following: and the process of supplying at least one of the group consisting of printing ink and dampening solution to a printing press to remove the non-image portion of the image recording layer.

[0094] <31> A lithographic printing method, comprising: taking <1> to <29> The process of exposing the on-machine developing type lithographic printing plate master as an image as described in any one of the following steps: the process of producing a lithographic printing plate by supplying at least one of the group consisting of printing ink and dampening solution to a printing press to remove the image recording layer of the non-image portion; and the process of printing using the obtained lithographic printing plate.

[0095] Invention Effects

[0096] According to one embodiment of the present invention, an in-machine developing type lithographic printing plate with excellent stability over time can be provided.

[0097] 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 on-machine developing type lithographic printing plate original can be provided. Attached Figure Description

[0098] Figure 1 This is a schematic cross-sectional view of one preferred embodiment of the aluminum support body used in the present invention.

[0099] Figure 2 This is a schematic cross-sectional view of one embodiment of an aluminum support having an anodized coating.

[0100] 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 with an anodic oxide film.

[0101] Figure 4 This is a side view illustrating an example of a radial unit in an electrochemical roughening process using alternating current in a method for manufacturing an aluminum support with an anodized film.

[0102] Figure 5 This is a side view representing the concept of a brushing and polishing process used in the mechanical roughening treatment of an aluminum support with an anodized film during the manufacturing process.

[0103] Figure 6 This is a schematic diagram of an anodizing apparatus used in the anodizing process of a method for manufacturing an aluminum support with an anodized film. Detailed Implementation

[0104] 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.

[0105] In addition, in this specification, the "~" sign indicating a numerical range is used to imply that the numerical values ​​before and after it are included as lower and upper limits.

[0106] 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.

[0107] Furthermore, in the designation of groups (atomic groups) in this specification, the designations without substitution and unsubstituted not only include 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).

[0108] 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.

[0109] 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.

[0110] Unless otherwise specified, each component in the composition or each constituent unit in the polymer in this invention may be contained individually or in combination with two or more.

[0111] Furthermore, in this invention, the amount of each component in the composition or each constituent unit in the polymer, in the case where there are multiple substances or constituent units that correspond to each component in the composition or each constituent unit in the polymer, refers to the total amount of the corresponding multiple substances present in the composition or the corresponding multiple constituent units present in the polymer, unless otherwise specified.

[0112] Furthermore, in this invention, a combination of two or more preferred methods is a more preferred method.

[0113] 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.

[0114] In this invention, 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 operations such as exposure and development 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, for example, a lithographic printing plate original used when printing a portion of the printing plate in monochrome or two colors in color newspaper printing, and is mounted on an unused printing cylinder.

[0115] In this invention, "excellent printing durability" refers to the large number of printable sheets of a lithographic printing plate. Hereinafter, the printing durability when using ultraviolet-curable ink (UV ink) as the ink used in printing will also be referred to as "UV printing durability".

[0116] The present invention will now be described in detail.

[0117] (Original plate for machine-developed offset printing)

[0118] The on-machine developing type lithographic printing plate master (also simply referred to as "lithographic printing plate master") involved in this invention comprises, in sequence, a support, an image recording layer, and an outermost layer. The image recording layer contains an infrared absorber, an electron-accepting polymerization initiator, and a polymerizable compound. The LUMO value of the electron-accepting polymerization initiator minus the LUMO value of the infrared absorber is 0.45 eV or higher. The outermost layer contains a color-changing compound.

[0119] Furthermore, the on-machine developing type lithographic printing plate original involved in this invention is preferably a negative type lithographic printing plate original.

[0120] As with the lithographic printing plates described in the prior art of Patent Document 1 or Patent Document 2, the inventors have discovered that the stability of the prior art of negative lithographic printing plates is sometimes insufficient over time.

[0121] Through in-depth research, the inventors discovered that by adopting the above-described structure, it is possible to provide an on-machine developing type lithographic printing plate with excellent stability over time.

[0122] While the detailed mechanism by which the above effects are achieved is unclear, the following speculations are made.

[0123] It is inferred that by including an infrared absorber, an electron-accepting polymerization initiator, and a polymerizable compound in the image recording layer, the LUMO of the electron-accepting polymerization initiator minus the LUMO of the infrared absorber is 0.45 eV or higher, which suppresses electron donation from the infrared absorber to the electron-accepting polymerization initiator before exposure, suppressing the generation of polymerization initiation seeds before exposure. Furthermore, by including a color-changing compound in the outermost layer, the generation of polymerization initiation seeds due to white light, etc., is suppressed, resulting in excellent stability over time.

[0124] The following is a detailed description of each component of the original offset printing plate involved in this invention.

[0125] <Image Recording Layer>

[0126] The lithographic printing plate of the present invention comprises a support, an image recording layer and an outermost layer, wherein the image recording layer comprises an infrared absorber, an electron-donating polymerization initiator and a polymerizable compound, and the LUMO of the electron-donating polymerization initiator minus the LUMO of the infrared absorber is 0.45 eV or higher.

[0127] The image recording layer used in this invention is preferably a negative image recording layer, and more preferably a water-soluble or water-dispersible negative image recording layer.

[0128] Regarding the lithographic printing plate original involved in this invention, from the viewpoint of machine developability, it is preferable that the unexposed portion of the image recording layer can be removed by at least one of dampening solution and printing ink.

[0129] [The Relationship Between Electron-Accepting Polymerization Initiators and Infrared Absorbers]

[0130] In the image recording layer of the present invention, the LUMO of the electron-receiving polymerization initiator minus the LUMO of the infrared absorber is 0.45 eV or more. From the viewpoints of stability over time, UV plate wear suppression, GLV suitability, improved sensitivity, and UV printing durability, it is preferably 0.58 eV or more, more preferably 0.62 eV or more, even more preferably 0.62 eV to 1.00 eV, and particularly preferably 0.62 eV to 0.95 eV.

[0131] In addition, a negative value means that the LUMO of the above-mentioned infrared absorber is higher than that of the above-mentioned electron-accepting polymerization initiator.

[0132] Furthermore, "plate abrasion" 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 abrasion" in the lithographic printing plate is an indicator of "not easily subject to plate abrasion." Moreover, even when using UV inks, excellent plate abrasion suppression can be described as excellent UV plate abrasion suppression.

[0133] Furthermore, in the exposure of the original offset printing plate, an exposure machine equipped with an exposure head using GLV (Grating Light Valve) technology is sometimes used.

[0134] If this exposure machine is used for exposure, the halftone image becomes coarser in the scanning direction, thus appearing as striped unevenness. This striped unevenness is sometimes also called banding unevenness.

[0135] The superior inhibitory properties of the above-mentioned striped, uneven structure are sometimes referred to as superior GLV suitability.

[0136] In this invention, the MO (molecular orbital) energies of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are calculated using the following method.

[0137] First, free counterions in the compounds being calculated are excluded from the calculation. For example, counterions are excluded from the calculation in cationic electron-donating initiators and cationic infrared absorbing pigments, and counterions are excluded from the calculation in anionic electron-donating initiators.

[0138] The term "free" here refers to the fact that the compound in question and its counter ion are not linked by covalent bonds.

[0139] Structure optimization was performed using the quantum chemical computation software Gaussian16 under DFT(B3LYP / 6-31G(d)).

[0140] For the MO energy calculation, the optimal structure obtained through the above structural optimization was used in the quantum chemical calculation software Gaussian16 under DFT(B3LYP / 6-31+G(d,p) / PCM(solvent = methanol)). Additionally, for compounds containing iodine, calculations were performed under DFT(B3LYP / DGDZVP / PCM(solvent = methanol)).

[0141] The optimal structure referred to here is the structure with the most stable total energy obtained through DFT calculations. Structural optimization is repeated as needed to discover the most stable structure.

[0142] The MO energy Ebare (unit: Hartley) obtained through the above MO energy calculation is converted into Escaled (unit: eV) used as the value for HOMO and LUMO in this invention, according to the following formula.

[0143] [HOMO calculation formula] Escaled = 0.823168 × 27.2114 × Ebare - 1.07634

[0144] [Formula for calculating LUMO] Escaled = 0.820139 × 27.2114 × Ebare - 1.086039

[0145] Additionally, 27.2114 is a coefficient used only to convert Hartley to eV, and 0.823168 and -1.07634 used in calculating HOMO and 0.820139 and -1.086039 used in calculating LUMO are adjustment coefficients, determined by matching the calculated and measured values ​​of HOMO and LUMO for the compounds being calculated.

[0146] The following is a detailed description of the components contained in the image recording layer.

[0147] [Infrared absorber]

[0148] The image recording layer in this invention contains an infrared absorber.

[0149] There are no particular limitations on what can be used as an infrared absorber; for example, pigments and dyes can be cited.

[0150] 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.

[0151] Preferred dyes among these dyes include anthocyanins, squaric acid cyanines, pyranonium salts, nickel thiol complexes, and indocyanines, with anthocyanins or indocyanines being more preferred. Among these, anthocyanins are particularly preferred.

[0152] As the aforementioned infrared absorber, a cationic polymethyl pigment having an oxygen atom, nitrogen atom, or halogen atom at the meta position is 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 reaction, anthocyanins are preferred.

[0153] 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.

[0154] Furthermore, compounds described in paragraphs 0008-0009 of Japanese Patent Application Publication No. 5-5005 and paragraphs 0022-0025 of Japanese Patent Application Publication No. 2001-222101 are preferred. As a pigment, compounds described in paragraphs 0072-0076 of Japanese Patent Application Publication No. 2008-195018 are preferred.

[0155] Furthermore, the infrared absorber preferably comprises a compound represented by the following Formula 1.

[0156] [Chemical Formula 7]

[0157]

[0158] In Formula 1, R1 and R2 independently represent hydrogen atoms or alkyl groups, and R1 and R2 can be linked together to form a ring. R3 to R6 independently represent hydrogen atoms or alkyl groups, R7 and R8 independently represent alkyl or aryl groups, Y1 and Y2 independently represent oxygen atoms, sulfur atoms, -NR0- or dialkylmethylene groups, R0 represents hydrogen atoms, alkyl groups or aryl groups, Ar1 and Ar2 independently represent groups that form benzene or naphthalene rings that can have the groups represented by Formula 2 described later, and A1 represents -NR9R. 10 -X1-L1 or the group represented by Formula 2 as described later, R9 and R 10Each of Ar1 and Ar2 independently represents an alkyl, aryl, alkoxycarbonyl, or arylsulfonyl group; X1 represents an oxygen atom or a sulfur atom; L1 represents a hydrocarbon group, a heteroaryl group, or a group whose bond with X1 is broken by heat or infrared exposure; Za represents a counterion that neutralizes the charge; and at least one of Ar1 and Ar2 has a group represented by the following formula 2.

[0159] -X Formula 2

[0160] In Equation 2, X represents a halogen atom, -C(=O)-X2-R 11 -C(=O)-NR 12 R 13 -OC(=O)-R 14 -CN, -SO2NR 15 R 16 Or perfluoroalkyl, X2 represents a single bond or oxygen atom, R 11 and R 14 Each can be independently represented by an alkyl or aryl group, R 12 、R 13 、R 15 and R 16 Each can be represented independently as a hydrogen atom, alkyl group, or aryl group.

[0161] Ar1 and Ar2 represent the groups that form the benzene ring or naphthalene ring, respectively. Substituents other than -X may be present on the aforementioned benzene ring and naphthalene ring. Examples of substituents include alkyl, alkoxy, aryloxy, amino, alkylthio, arylthio, carboxyl, carboxylic acid ester, sulfonyl, sulfonate ester, and groups formed by combining these, but alkyl groups are preferred.

[0162] Furthermore, in Formula 1, at least one of Ar1 and Ar2 has a group represented by Formula 2 above. From the viewpoint of printability, visual recognizability, and the time-dependent preservation stability (time stability) of the coating liquid used to form the image recording layer, it is preferable that both Ar1 and Ar2 have a group represented by Formula 2 above.

[0163] In Equation 2, X represents a halogen atom, -C(=O)-X2-R 11 -C(=O)-NR 12 R 13 -OC(=O)-R 14 -CN, -SO2NR 15 R 16 Alternatively, perfluoroalkyl groups, from the viewpoints of printability, visual legibility, and stability over time, are preferred, preferably with halogen atoms or -C(=O)-X2-R. 11 -C(=O)-NR 12 R 13 -OC(=O)-R 14CN or -SO2NR 15 R 16 More preferably, halogen atoms, -C(=O)-OR 11 -C(=O)-NR 12 R 13 or -OC(=O)-R 14 Further preferred are halogen atoms, -C(=O)-OR 11 or -OC(=O)-R 14 Further preferably, it consists of fluorine atoms, chlorine atoms, bromine atoms, or -C(=O)OR 17 The preferred atoms are chlorine or bromine atoms.

[0164] Furthermore, the X substituted with Ar1, the X substituted with Ar2, and the X substituted with Al can be the same group or different groups. Moreover, from the viewpoints of printability, visual recognizability, and stability over time, the X substituted with Ar1 and the X substituted with Ar2 are preferably the same group.

[0165] X2 represents a single bond or an oxygen atom, preferably an oxygen atom.

[0166] R 11 and R 14 Each of the terms represents an alkyl group or an aryl group independently, preferably an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms.

[0167] R 12 R 13 R 15 and R 16 Each of the following can be independently represented: hydrogen atom, alkyl group or aryl group, preferably hydrogen atom, alkyl group with 1 to 12 carbon atoms or aryl group with 6 to 12 carbon atoms, more preferably hydrogen atom or alkyl group with 1 to 12 carbon atoms, and even more preferably alkyl group with 1 to 12 carbon atoms.

[0168] R 17 The term represents alkyl or aryl, preferably alkyl with 1 to 12 carbon atoms or aryl with 6 to 12 carbon atoms, and more preferably alkyl with 1 to 12 carbon atoms.

[0169] A1 indicates -NR9R 10 From the viewpoints of print durability, visual legibility, and stability over time, -NR9R is preferred. 10 Or -X1-L1, more preferably -NR 18 R 19 -SR 20 .

[0170] Furthermore, from the viewpoints of UV plate wear inhibition, GLV suitability, and UV printing durability, A1 is preferably -X, more preferably a halogen atom, even more preferably a chlorine atom or a bromine atom, and especially preferably a chlorine atom.

[0171] R9 and R 10 Each of the following can be independently represented as alkyl, aryl, alkoxycarbonyl or arylsulfonyl, preferably an alkyl with 1 to 12 carbon atoms or an aryl with 6 to 12 carbon atoms, more preferably an alkyl with 1 to 12 carbon atoms.

[0172] X1 represents an oxygen atom or a sulfur atom. When L1 is a hydrocarbon group or a heteroaryl group, it is preferably a sulfur atom. L1 is preferably a group whose bond with X1 is broken by heat or infrared exposure.

[0173] L1 represents a hydrocarbon group, a heteroaryl group, or a group whose bond with X1 is broken by heat or infrared exposure. From the viewpoint of print durability, a hydrocarbon group or a heteroaryl group is preferred, an aryl group or a heteroaryl group is more preferred, and a heteroaryl group is even more preferred.

[0174] Furthermore, from the viewpoints of visual recognizability and inhibition of fading over time, L1 is preferably a group whose bond with X1 is broken by heat or infrared exposure.

[0175] Groups that break the bond with X1 through heat or infrared exposure will be described later.

[0176] R 18 and R 19 Each aryl group is represented independently, preferably an aryl group with 6 to 20 carbon atoms, and more preferably a phenyl group.

[0177] R 20 It represents a hydrocarbon group or a heteroaryl group, preferably an aryl or heteroaryl group, and more preferably a heteroaryl group.

[0178] As L1 and R 20 The heteroaryl groups in the sample are preferably the following groups.

[0179] [Chemical Formula 8]

[0180]

[0181] R1~R 10 The alkyl group in R0 is preferably an alkyl group with 1 to 30 carbon atoms, more preferably an alkyl group with 1 to 15 carbon atoms, and even more preferably an alkyl group with 1 to 10 carbon atoms. The alkyl group can be straight-chain, branched, or cyclic.

[0182] 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.

[0183] Of these alkyl groups, methyl, ethyl, propyl or butyl are particularly preferred.

[0184] Furthermore, the aforementioned alkyl groups may have substituents. Examples of substituents include alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, carboxylic acid ester, sulfonyl, sulfonate, alkoxycarbonyl, aryloxycarbonyl, and groups formed by combining them.

[0185] As R9, R 10 、R 18 、R 19 The aryl group in R0 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.

[0186] Furthermore, the aforementioned aryl group may have substituents. Examples of substituents include alkyl, alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, carboxylic acid ester, sulfonyl, sulfonate, alkoxycarbonyl, aryloxycarbonyl, and groups formed by combining them.

[0187] Specifically, examples of the aforementioned aryl groups include phenyl, naphthyl, p-tolyl, p-chlorophenyl, p-fluorophenyl, p-methoxyphenyl, p-dimethylaminophenyl, p-methylthiophenyl, and p-phenylthiophenyl.

[0188] Among these aryl groups, phenyl, p-methoxyphenyl, p-dimethylaminophenyl, or naphthyl are preferred.

[0189] R1 and R2 are preferably connected to form a ring.

[0190] When R1 and R2 are linked to form a ring, a 5- or 6-membered ring is preferred, and a 6-membered ring is more preferred. Furthermore, the ring formed by the linkage of R1 and R2 is preferably a hydrocarbon ring that can have olefinically unsaturated bonds.

[0191] Y1 and Y2 independently represent an oxygen atom, a sulfur atom, -NR0- or a dialkylmethylene, preferably -NR0- or a dialkylmethylene, more preferably a dialkylmethylene.

[0192] R0 represents a hydrogen atom, an alkyl group, or an aryl group, preferably an alkyl group.

[0193] R7 and R8 are preferably the same group.

[0194] Furthermore, R7 and R8 are each preferably straight-chain alkyl groups or alkyl groups with sulfonate groups at the end, more preferably methyl, ethyl or butyl groups with sulfonate groups at the end.

[0195] Furthermore, the counter cation of the sulfonate group can be a cation on the nitrogen atom in Formula 1, or an alkali metal cation or an alkaline earth metal cation.

[0196] Furthermore, from the viewpoint of improving the water solubility of the compound represented by Formula 1, R7 and R8 are each preferably alkyl groups having anionic structures, more preferably alkyl groups having carboxylic acid ester groups or sulfonate groups, and even more preferably alkyl groups having sulfonate groups at the end.

[0197] Furthermore, from the viewpoint of increasing the maximum absorption wavelength of the compound represented by Formula 1, and from the viewpoint of visual recognizability and printing durability in lithographic printing plates, R7 and R8 are each independently preferred to be alkyl groups having an aromatic ring, more preferably alkyl groups having an aromatic ring at the end, and particularly preferably 2-phenylethyl, 2-naphthylethyl or 2-(9-anthrayl)ethyl.

[0198] R3 to R6 each independently represent a hydrogen atom or an alkyl group, preferably a hydrogen atom.

[0199] Furthermore, from the viewpoints of stability over time, UV plate wear inhibition, GLV suitability, and UV printing durability, the compound represented by Formula 1 preferably has one or more halogen atoms, more preferably at least one of the compounds selected from the group including A1, Ar1, and Ar2 has one or more halogen atoms, and especially preferably A1, Ar1, and Ar2 each has one or more halogen atoms.

[0200] Furthermore, from the viewpoints of stability over time, UV plate wear inhibition, GLV compatibility, and UV printing durability, the compound represented by Formula 1 is more preferably having 2 or more halogen atoms, more preferably having 3 or more halogen atoms, and especially preferably having 3 or more but less than 6 halogen atoms.

[0201] Furthermore, chlorine or bromine atoms are preferably cited as examples of halogen atoms.

[0202] Furthermore, from the viewpoints of stability over time, UV plate wear inhibition, GLV suitability, and UV printing durability, the compound represented by Formula 1 preferably has a halogen atom in at least one of Ar1 and Ar2, more preferably has a chlorine atom or a bromine atom in at least one of Ar1 and Ar2, even more preferably has a bromine atom in at least one of Ar1 and Ar2, and especially preferably has a bromine atom in both Ar1 and Ar2.

[0203] Za represents the counter ion that neutralizes the charge. When specifying the type of anion, examples include sulfonate ions, carboxylate ions, tetrafluoroborate ions, hexafluorophosphate ions, perchlorate ions, sulfonamide anions, and sulfonamide anions. When specifying the type of cation, alkali metal ions, alkaline earth metal ions, ammonium ions, pyridinium ions, or sulfonium ions are preferred; sodium ions, potassium ions, ammonium ions, pyridinium ions, or sulfonium ions are more preferred; sodium ions, potassium ions, or ammonium ions are even more preferred; and sodium ions, potassium ions, or trialkylammonium ions are particularly preferred.

[0204] From the viewpoint of printability and visual recognizability, Za is preferably an organic anion containing carbon atoms, more preferably a sulfonate ion, a carboxylate ion, a sulfonamide anion or a sulfonamide anion, even more preferably a sulfonamide anion or a sulfonamide anion, and especially preferably a sulfonamide anion.

[0205] R1 to R8, R0, A1, Ar1, Ar2, Y1, and Y2 can have anionic or cationic structures. If all of R1 to R8, R0, A1, Ar1, Ar2, Y1, and Y2 are electrically neutral groups, then Za is a monovalent counter anion. However, if R1 to R8, R0, A1, Ar1, Ar2, Y1, and Y2 have two or more anionic structures, Za can also become a counter cation.

[0206] Furthermore, in Equation 1, if the part other than Za is electrically neutral, then Za can be omitted.

[0207] As a sulfonamide anion, arylsulfonamide anion is preferred.

[0208] Furthermore, bis(aryl)sulfonamide anion is preferred as the sulfonamide anion.

[0209] 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.

[0210] [Chemical Formula 9]

[0211]

[0212] From the viewpoint of visual recognition, the group whose bond with X1 is broken by heat or infrared exposure is preferably a group represented by any one of the following formulas (1-1) to (1-7), and more preferably a group represented by any one of the following formulas (1-1) to (1-3).

[0213] [Chemical Formula 10]

[0214]

[0215] In equations (1-1) to (1-7), ● represents the bonding site with X1 in equation 1, and R 10 Each can independently represent a hydrogen atom, alkyl group, alkenyl group, aryl group, or -OR group. 14 -NR 15 R 16 or -SR 17 R 11 Each of the following can be independently represented by a hydrogen atom, alkyl group, or aryl group; R 12 Indicates aryl, -OR 14 -NR 15 R 16 -SR 17 -C(=O)R 18 -OC(=O)R 18 Or halogen atoms, R 13 Indicates aryl, alkenyl, alkoxy, or onnnyl, R 14 ~R 17 Each of the following can be independently represented by a hydrogen atom, alkyl group, or aryl group; R 18 Each can be independently represented by alkyl, aryl, or -OR. 14 -NR 15 R 16 or -SR 17 Z 1 Represents counterions that neutralize charge.

[0216] R 10 、R 11 and R 14 ~R 18 Preferred method when it is alkyl and R 2 ~R 9 and R 0 The preferred method for alkyl groups is the same.

[0217] R 10 and R 13 The number of carbon atoms in the alkenyl group is preferably 1 to 30, more preferably 1 to 15, and even more preferably 1 to 10.

[0218] R 10 ~R 18 Preferred mode and R when it is aryl 0 The preferred method for aryl groups is the same.

[0219] From the perspective of visual recognition, R in equation (1-1) 10 Preferably alkyl, alkenyl, aryl, or -OR 14 -NR 15 R 16 or -SR 17 More preferably alkyl, -OR 14-NR 15 R 16 or -SR 17 More preferably alkyl or -OR 14 Especially preferred is -OR 14 .

[0220] Furthermore, R in equation (1-1) 10 When the alkyl group is alkyl, it is preferably an alkyl group having an arylthio group or an alkoxycarbonyl group at the α position.

[0221] In equation (1-1) R 10 For -OR 14 In the case of R 14 Preferably, it is an alkyl group, more preferably an alkyl group having 1 to 8 carbon atoms, and even more preferably isopropyl or tert-butyl, especially tert-butyl.

[0222] From the perspective of visual recognition, R in equation (1-2) 11 Hydrogen atoms are preferred.

[0223] Furthermore, from the perspective of visual recognition, R in equation (1-2) 12 The preferred option is -C(=O)OR 14 -OC(=O)OR 14 Or halogen atoms, more preferably -C(=O)OR 14 or -OC(=O)OR 14 In equation (1-2), R 12 -C(=O)OR 14 or -OC(=O)OR 14 In the case of R 14 Alkyl groups are preferred.

[0224] From the perspective of visual recognition, R in equation (1-3) 11 Each is preferably a hydrogen atom or an alkyl group, and at least one R in formula (1-3) is... 11 More preferably, it is an alkyl group.

[0225] Furthermore, R 11 The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 3 to 10 carbon atoms.

[0226] Moreover, R 11 The alkyl group is preferably a branched alkyl or cycloalkyl group, more preferably a secondary or tertiary alkyl group, or a cycloalkyl group, and even more preferably isopropyl, cyclopentyl, cyclohexyl or tert-butyl.

[0227] Furthermore, from the perspective of visual recognition, R in equation (1-3) 13Preferably, it is aryl, alkoxy, or onnyl, more preferably p-dimethylaminophenyl or pyridinium, and even more preferably pyridinium.

[0228] As R 13 Examples of onnnyl groups include pyridinium, ammonium, and sulfonium. Onnnyl groups can have substituents. Examples of substituents include alkyl, alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, sulfonyl, alkoxycarbonyl, aryloxycarbonyl, and combinations thereof, but alkyl, aryl, and combinations thereof are preferred.

[0229] Preferably, pyridinium group is used; more preferably, N-alkyl-3-pyridinium group, N-benzyl-3-pyridinium group, N-(alkoxypolyalkoxyalkyl)-3-pyridinium group, N-alkoxycarbonylmethyl-3-pyridinium group, N-alkyl-4-pyridinium group, N-benzyl-4-pyridinium group, N-(alkoxypolyalkoxyalkyl)-4-pyridinium group, and N-alkoxycarbonylmethyl-4-pyridinium group are used. -Pyridinium or N-alkyl-3,5-dimethyl-4-pyridinium, more preferably N-alkyl-3-pyridinium or N-alkyl-4-pyridinium, particularly preferably N-methyl-3-pyridinium, N-octyl-3-pyridinium, N-methyl-4-pyridinium or N-octyl-4-pyridinium, most preferably N-octyl-3-pyridinium or N-octyl-4-pyridinium.

[0230] Furthermore, in R 13 In the case of a pyridinium group, counter anions include sulfonate ions, carboxylate ions, tetrafluoroborate ions, hexafluorophosphate ions, p-toluenesulfonate ions, perchlorate ions, etc., with p-toluenesulfonate ions or hexafluorophosphate ions being preferred.

[0231] From the perspective of visual recognition, R in equation (1-4) 10 Preferably alkyl or aryl, more preferably 2 Rs 10 One of them is alkyl and the other is aryl.

[0232] From the perspective of visual recognition, R in equation (1-5) 10 Preferably alkyl or aryl, more preferably aryl, and even more preferably p-methylphenyl.

[0233] From the perspective of visual recognition, R in equation (1-6) 10 Each is preferably alkyl or aryl, more preferably methyl or phenyl.

[0234] From the perspective of visual recognition, regarding Z in equation (1-7) 1 Any counterion that neutralizes the charge can be included in the above-mentioned Za as a whole compound.

[0235] Z 1 Preferably, it is a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a p-toluenesulfonate ion, or a perchlorate ion, more preferably a p-toluenesulfonate ion or a hexafluorophosphate ion.

[0236] Furthermore, the groups that break the bond with X1 by heat or infrared exposure are particularly preferably groups represented by formulas (1-8).

[0237] [Chemical Formula 11]

[0238]

[0239] In equation (1-8), ● represents the bonding site with X1 in equation 1, and R 19 and R 20 Each of these represents an alkyl group independently, and Za' represents a counterion that neutralizes the charge.

[0240] The pyridinium ring in formula (1-8) and the R 20 The bonding position of the hydrocarbon group is preferably at the 3 or 4 position of the pyridinium ring, more preferably at the 4 position of the pyridinium ring.

[0241] R 19 and R 20 The alkyl group can be straight-chain, branched, or cyclic.

[0242] Furthermore, the aforementioned alkyl group may have substituents, with alkoxy groups and terminal alkoxy polyalkoxide groups being preferred examples.

[0243] R 19 Preferably, it is an alkyl group having 1 to 12 carbon atoms, more preferably a straight-chain alkyl group having 1 to 12 carbon atoms, even more preferably a straight-chain alkyl group having 1 to 8 carbon atoms, and especially preferably methyl or n-octyl.

[0244] R 20 Preferably, it is an alkyl group having 1 to 8 carbon atoms, more preferably a branched alkyl group having 3 to 8 carbon atoms, and even more preferably isopropyl or tert-butyl, especially isopropyl.

[0245] Regarding Za', any counterion that neutralizes the charge can be included in the aforementioned Za as a whole compound.

[0246] Za' 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 p-toluenesulfonate ion or a hexafluorophosphate ion.

[0247] Hereinafter, as preferred specific examples of compounds represented by Formula 1, examples include core structures A-1 to A-54, counter anions B-1 to B-10, and counter cations C-1 to C-3; however, the present invention is not limited thereto. Other specific examples of compounds represented by Formula 1 include compounds obtained by combining one core structure each of A-1 to A-9, A-11 to A-20, and A-22 to A-54 with counter anions B-1 to B-10, and compounds obtained by combining one core structure each of A-10 and A-21 with counter cations C-1 to C-3.

[0248] [Chemical Formula 12]

[0249]

[0250] [Chemical Formula 13]

[0251]

[0252] [Chemical Formula 14]

[0253]

[0254] [Chemical Formula 15]

[0255]

[0256] [Chemical Formula 16]

[0257]

[0258] [Chemical Formula 17]

[0259]

[0260] [Chemical Formula 18]

[0261]

[0262] [Chemical Formula 19]

[0263]

[0264] [Chemical Formula 20]

[0265]

[0266] [Chemical Formula 21]

[0267]

[0268] [Chemical Formula 22]

[0269]

[0270] [Chemical Formula 23]

[0271] Na + K + (CH3CH2)3NH +

[0272] C-1 C-2 C-3

[0273] Furthermore, as the compound represented by Formula 1, the compound shown below is also preferred. Additionally, TsO - This indicates the p-toluenesulfonate anion.

[0274] [Chemical Formula 24]

[0275]

[0276] [Chemical Formula 25]

[0277]

[0278] [Chemical Formula 26]

[0279]

[0280] There are no particular limitations on the method for preparing the compound represented by Formula 1, and it can be prepared by referring to known methods for preparing anthocyanins. Furthermore, the method described in International Publication No. 2016 / 027886 is preferred.

[0281] From the viewpoint of printability and visual recognizability, the highest occupied orbital (HOMO) of the infrared absorber is preferably -5.250 eV or less, more preferably -5.30 eV or less, even more preferably -5.80 eV or more and -5.35 eV or less, and particularly preferably -5.65 eV or more and -5.40 eV or less.

[0282] From the viewpoints of stability over time, UV plate wear inhibition, GLV compatibility, improved sensitivity, and UV printing durability, the minimum unoccupied molecular orbital (LUMO) of the aforementioned infrared absorber is preferably less than -3.70 eV, more preferably less than -3.80 eV, even more preferably greater than -4.20 eV and less than -3.80 eV, and particularly preferably greater than -4.00 eV and less than -3.80 eV.

[0283] Infrared absorbers can be used in single or multiple ways.

[0284] Furthermore, as an infrared absorber, it can be used in conjunction with pigments and dyes.

[0285] The content of the infrared absorber is preferably 0.1% to 10.0% by mass, more preferably 0.5% to 5.0% by mass, relative to the total mass of the image recording layer.

[0286] Electron-receiving polymerization initiators

[0287] The image recording layer in this invention contains an electron-accepted polymerization initiator.

[0288] 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 movement to generate free radicals and other polymerization initiators.

[0289] Electron-accepting polymerization initiators are compounds that generate polymerization initiators such as free radicals or cations through the energy of light, heat, or both. They can appropriately select and use known thermal polymerization initiators, compounds with bonds having low bond dissociation energies, photopolymerization initiators, etc.

[0290] As an electron-accepting polymerization initiator, a free radical polymerization initiator is preferred, and an onium salt compound is more preferred.

[0291] Furthermore, an infrared-sensitive polymerization initiator is preferred as the electron-receiving polymerization initiator.

[0292] Furthermore, from the viewpoints of stability over time, UV plate wear inhibition, GLV suitability, improved sensitivity, and UV printing durability, iodonium salt compounds or compounds containing halogenated alkyl groups are preferred as electron-receiving polymerization initiators, and compounds containing halogenated alkyl groups are more preferred.

[0293] Furthermore, from the viewpoints of stability over time, UV plate wear suppression, GLV suitability, improved sensitivity, and UV printing durability, compounds with fully haloalkyl sulfonyl groups are preferred as compounds having a trihalomethyl sulfonyl group, compounds with a tribromomethyl sulfonyl group are more preferred, and compounds with a tribromomethyl sulfonyl group are especially preferred as compounds having a tribromomethyl sulfonyl group.

[0294] 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.

[0295] Specific examples of these compounds are shown below, but the invention is not limited thereto.

[0296] 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.

[0297] 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.

[0298] Among them, sulfonamide anion or sulfonamide anion is preferred, and sulfonamide anion is more preferred.

[0299] As a sulfonamide anion, arylsulfonamide anion is preferred.

[0300] Furthermore, bis(aryl)sulfonamide anion is preferred as the sulfonamide anion.

[0301] Specific examples of sulfonamide anions or sulfonamide anions include the compounds described in International Publication No. 2019 / 013268.

[0302] Furthermore, as the aforementioned electron-receiving polymerization initiator, from the viewpoint of the time-dependent visual recognizability after exposure, the developability, and the UV printing durability of 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).

[0303] [Chemical Formula 27]

[0304]

[0305] In equations (II) and (III), X A R represents a halogen atom. A 、R A1 and R A2 Each of the following groups can be independently represented as a monovalent hydrocarbon group with 1 to 20 carbon atoms.

[0306] R in equation (II) A The preferred group is aryl.

[0307] As X in equations (II) and (III) A Examples of suitable atoms include fluorine, chlorine, bromine, and iodine. Among these, chlorine or bromine atoms are preferred due to their superior sensitivity, and bromine atoms are particularly preferred.

[0308] Furthermore, in equations (II) and (III), R A 、R A1 and R A2 Each group is preferably aryl, and from the viewpoint of achieving an excellent balance between sensitivity and storage stability, aryl groups substituted with amide groups are more preferred.

[0309] Furthermore, as the aforementioned electron-receiving polymerization initiator, it is particularly preferred to include a compound represented by formula (IV).

[0310] [Chemical Formula 28]

[0311]

[0312] In equation (IV), X A R represents a halogen atom. A3 and R A4 Each group independently represents a 1-valent hydrocarbon group containing 1 to 20 hydrogen or carbon atoms, with pA and qA independently representing integers from 1 to 5. Where pA + qA = 2 to 6.

[0313] Specific examples of electron-receiving polymerization initiators include the compounds shown below, but the present invention is not limited to these.

[0314] [Chemical Formula 29]

[0315]

[0316] [Chemical Formula 30]

[0317]

[0318] [Chemical Formula 31]

[0319]

[0320] [Chemical Formula 32]

[0321]

[0322] [Chemical Formula 33]

[0323]

[0324] [Chemical Formula 34]

[0325]

[0326] [Chemical Formula 35]

[0327]

[0328] From the viewpoints of stability over time, UV plate wear inhibition, GLV compatibility, and UV printing durability, the minimum unoccupied molecular orbital (LUMO) of the electron-dependent polymerization initiator is preferably greater than -3.3 eV, more preferably greater than -3.2 eV.

[0329] Furthermore, as an upper limit, from the viewpoint of improving sensitivity and reducing the likelihood of plate wear, it is preferably -3.00eV or less, and more preferably -3.02eV or less.

[0330] Electron-accepting polymerization initiators can be used alone or in combination with two or more.

[0331] 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 particularly preferably 0.8% to 20% by mass.

[0332] Furthermore, from the viewpoints of stability over time, UV plate wear inhibition, GLV compatibility, and UV printing durability, the content of electron-accepted polymerization initiator in the image recording layer is preferably greater than the content of infrared absorber, more preferably 1.5 to 5 times the content of infrared absorber, and especially preferably 2 to 4 times the content of infrared absorber.

[0333] [Electron-donating polymerization initiators (polymerization aids)]

[0334] The image recording layer in this invention preferably contains an electron-donating polymerization initiator (also known as a "polymerization aid").

[0335] Electron-donating polymerization initiators are compounds that, when exposed to infrared light, stimulate the electrons of the infrared absorber or allow them to move within the molecule, and then, through intermolecular electron movement, supply an electron to the orbital of the infrared absorber to generate a free radical or other polymerization initiating species.

[0336] As an electron-donating polymerization initiator, an electron-donating free radical polymerization initiator is preferred.

[0337] From the viewpoint of print durability, the image recording layer preferably contains a borate compound, and more preferably a borate compound.

[0338] From the viewpoint of visual recognition and color development, tetraarylborate compounds or monoalkyltriarylborate compounds are preferred as borate compounds, and tetraarylborate compounds are more preferred.

[0339] Furthermore, from the viewpoints of UV plate wear suppression, printing durability, and visual recognizability, tetraarylborate compounds having one or more electron-donating groups are preferred as borate compounds, and tetraarylborate compounds having one electron-donating group in each aryl group are more preferred.

[0340] From the viewpoints of UV plate wear suppression, printing durability, and visual recognizability, alkyl or alkoxy groups are preferred as the electron-donating groups mentioned above. Alkoxy groups are more preferred.

[0341] 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.

[0342] Furthermore, as a countercation of the borate compound, the infrared absorber described in this specification may be a cationic polymethimide pigment. For example, the aforementioned borate compound may be used as a countercation of anthocyanin.

[0343] As a borate compound, sodium tetraphenylborate is particularly preferred.

[0344] 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.

[0345] [Chemical Formula 36]

[0346]

[0347] 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 is preferably -6.00 eV or more, more preferably -5.95 eV or more, even more preferably -5.93 eV or more, and particularly preferably greater than -5.90 eV.

[0348] Furthermore, as an upper limit, it is preferably below -5.00 eV, and more preferably below -5.40 eV.

[0349] Electron-donating polymerization initiators can be used alone or in combination with two or more.

[0350] From the viewpoint of sensitivity and print 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, relative to the total mass of the image recording layer.

[0351] In this invention, the polymerization initiator can be a compound that forms a counter salt between an electron-donating polymerization initiator and an electron-accepting polymerization initiator. Preferably, the electron-accepting polymerization initiator and the electron-donating polymerization initiator are compounds that form a salt by comprising a cation having an electron-accepting polymerization initiator structure and an anion having an electron-donating polymerization initiator structure.

[0352] For example, in this invention, it is preferred to form a countersalt by an anion in an electron-donating polymerization initiator and a cation in an electron-accepting polymerization initiator; more preferably, it is a countersalt by an onium cation and a borate anion; even more preferably, it is a countersalt by an iodonium cation or a sulfonium cation and a borate anion; and especially preferably, it is a countersalt by a diaryliodonium cation or a triarylsulfonium cation and a tetraarylborate anion.

[0353] The preferred methods for the anions in electron-donating polymerization initiators and the cations in electron-accepting polymerization initiators are the same as those for the previously described preferred methods for the anions in electron-donating polymerization initiators and the cations in electron-accepting polymerization initiators.

[0354] When the image recording layer contains an anion as an electron-donating polymerization initiator and a cation as an electron-accepting polymerization initiator (i.e., when it contains a compound that forms the aforementioned countersalt), the image recording layer contains both an electron-accepting polymerization initiator and the aforementioned electron-donating polymerization initiator.

[0355] Furthermore, compounds that form countersalts with electron-donating and electron-accepting polymerization initiators can be used as either electron-donating or electron-accepting polymerization initiators.

[0356] Furthermore, the compound formed by the countersalt of the electron-donating polymerization initiator and the electron-accepting polymerization initiator can be used in combination with the described electron-donating polymerization initiator or with the described electron-accepting polymerization initiator.

[0357] [The Relationship Between Infrared Absorbers and Electron-Donating Polymerization Initiators]

[0358] In the image recording layer of the present invention, from the viewpoint of UV plate wear inhibition and printing durability, the HOMO value of the infrared absorber and the HOMO value of the electron-donating polymerization initiator are preferably 0.70 eV or less, more preferably 0.60 eV or less, further preferably 0.55 eV or less, especially preferably 0.50 eV or less, and most preferably 0.50 eV to -0.10 eV.

[0359] In addition, a negative value means that the HOMO of the aforementioned electron-donating polymerization initiator is higher than that of the aforementioned infrared absorber.

[0360] [Polymerizing compounds]

[0361] The image recording layer in this invention contains a polymeric compound.

[0362] In this invention, a polymerizable compound refers to a compound having polymerizable groups.

[0363] There are no particular limitations on the polymerizable group; any known polymerizable group is acceptable, but an olefinically unsaturated group is preferred. Furthermore, the polymerizable group can be a free radical polymerizable group or a cationic polymerizable group, but a free radical polymerizable group is preferred.

[0364] Examples of free radical polymerizable groups include (meth)acryloyl, allyl, vinylphenyl, and vinyl groups. From a reactivity point of view, (meth)acryloyl is preferred.

[0365] The molecular weight (weight-average molecular weight in the case of a molecular weight distribution) of the polymeric compound is preferably 50 or more and less than 2,500.

[0366] The polymerizable compounds used in this invention can be, for example, free radical polymerizable compounds or cationic polymerizable compounds, and are preferably addition polymerizable compounds (olefinic unsaturated compounds) having at least one olefinic unsaturated bond.

[0367] As an olefinically unsaturated compound, it is preferred to be a compound having at least one terminal olefinically unsaturated bond, and more preferably a compound having two or more terminal olefinically unsaturated bonds. The polymerizable compound may be in the chemical form of a monomer, prepolymer (i.e., dimer, trimer), oligomer, or mixture thereof.

[0368] Of these, from the viewpoint of UV printing durability, polymeric compounds containing 3 or more functional groups are preferred, polymeric compounds containing 7 or more functional groups are more preferred, and polymeric compounds containing 10 or more functional groups are even more preferred. Furthermore, from the viewpoint of UV printing durability in the obtained lithographic printing plate, the polymeric compounds preferably contain olefinically unsaturated compounds with 3 or more functional groups (preferably 7 or more functional groups, more preferably 10 or more functional groups), and even more preferably (meth)acrylate compounds with 3 or more functional groups (preferably 7 or more functional groups, more preferably 10 or more functional groups).

[0369] Furthermore, from the viewpoint of machine developability and contamination inhibition, the polymeric compound containing two or fewer functions is preferred, more preferably containing a difunctional polymeric compound, and especially preferably containing a difunctional (meth)acrylate compound.

[0370] From the viewpoints of print durability, machine developability, and contamination inhibition, the content of polymeric compounds with two or fewer functions (preferably difunctional polymeric compounds) is preferably 20% to 100% by mass, more preferably 5% to 100% by mass, and especially preferably 50% to 100% by mass, relative to the total mass of the polymeric compounds in the aforementioned image recording layer.

[0371] <<Oligomers>>

[0372] As a polymeric compound contained in the image recording layer, it is preferable to contain a polymeric compound as an oligomer (hereinafter also simply referred to as "oligomer").

[0373] In this invention, oligomers refer to polymeric compounds with a molecular weight (weight average molecular weight in the case of a molecular weight distribution) of 600 or more and 10,000 or less, and containing at least one polymeric group.

[0374] From the viewpoint of excellent chemical resistance and UV printing durability, the molecular weight of the oligomer is preferably 1,000 or more and 5,000 or less.

[0375] Furthermore, from the viewpoint of improving UV printing durability, the number of polymeric groups in one molecule of oligomer is preferably two or more, more preferably three or more, even more preferably six or more, and particularly preferably ten or more.

[0376] Furthermore, there is no particular upper limit to the number of polymeric groups in the oligomer, but the number of polymeric groups is preferably 20 or less.

[0377] From the viewpoint of UV printing durability and machine developability, the oligomer preferably has 7 or more polymeric groups and a molecular weight of 1,000 or more and 10,000 or less. More preferably, it has 7 or more and 20 or less polymeric groups and a molecular weight of 1,000 or more and 5,000 or less.

[0378] In addition, it may contain polymer components that may be generated during the manufacturing process of oligomers.

[0379] From the viewpoints of UV printing durability, visual recognizability, and on-machine developability, the oligomer preferably comprises at least one selected from the group consisting of compounds having urethane bonds, compounds having ester bonds, and compounds having epoxy residues, and more preferably comprises a compound having urethane bonds.

[0380] In this invention, an epoxy residue refers to a structure formed by an epoxy group, for example, representing a structure identical to the structure obtained by reacting an acid group (carboxylic acid group, etc.) with an epoxy group.

[0381] Examples of oligomers include compounds having urethane bonds, preferably compounds having at least a group represented by formula (Ac-1) or formula (Ac-2), and more preferably compounds having at least a group represented by formula (Ac-1).

[0382] [Chemical Formula 37]

[0383]

[0384] 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.

[0385] As L 1 ~L 4 Each 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.

[0386] 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).

[0387] [Chemical Formula 38]

[0388]

[0389] 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).

[0390] Furthermore, as a compound having urethane bonds, a compound in which polymerizable groups are introduced into a polyurethane obtained by reacting a polyisocyanate compound with a polyol compound can be used.

[0391] For example, a compound having urethane bonds can be obtained by reacting a compound having epoxy and polymerizable groups with a polyurethane oligomer, which is obtained by reacting a polyol compound having acid groups with a polyisocyanate compound.

[0392] The number of polymerizable groups in compounds having ester bonds, which are examples of oligomers, is preferably three or more, and more preferably six or more.

[0393] Examples of oligomers include compounds containing epoxy residues, preferably compounds containing hydroxyl groups within the compound.

[0394] Furthermore, the number of polymerizable groups in the compound having epoxy residues is preferably 2 to 6, more preferably 2 to 3.

[0395] For example, the above-mentioned compound having epoxy residues can be obtained by reacting acrylic acid with a compound having epoxy groups.

[0396] Specific examples of oligomers are shown below, but the oligomers used in this invention are not limited thereto.

[0397] As oligomers, commercially available products can be used, such as UA-510H, UA-306H, UA-306I, UA-306T (all manufactured by KYOEISHA CHEMICAL CO., LTD.), UV-1700B, UV-6300B, UV7620EA (all manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), U-15HA (manufactured by Shin-Nakamura Chemical Co., Ltd.), EBECRYL450, EBECRYL657, EBECRYL885, EBECRYL800, EBECRYL3416, and EBECRYL860 (all manufactured by DAICEL-ALLNEX LTD.), but are not limited to these.

[0398] From the viewpoint of improving chemical resistance, UV printing durability, and the suppression of on-machine development residue, the content of oligomers is preferably 30% to 100% by mass relative to the total mass of polymeric compounds in the image recording layer, more preferably 50% to 100% by mass, and even more preferably 80% to 100% by mass.

[0399] <<Low molecular weight polymeric compounds>>

[0400] Polymerizable compounds may also include polymerizable compounds other than the oligomers mentioned above.

[0401] From the viewpoint of chemical resistance, low molecular weight polymeric compounds are preferred as polymeric compounds other than oligomers. These low molecular weight polymeric compounds can be in chemical forms such as monomers, dimers, trimers, or mixtures thereof.

[0402] Furthermore, from the viewpoint of chemical resistance, the preferred polymeric compound is selected from at least one polymeric compound that includes polymeric compounds having three or more olefinic unsaturated groups and polymeric compounds having an isocyanurate ring structure.

[0403] In this invention, low molecular weight polymeric compounds refer to polymeric compounds with a molecular weight (weight-average molecular weight in the case of a molecular weight distribution) of 50 or more and less than 600.

[0404] From the viewpoint of excellent chemical resistance, UV printing durability, and inhibition of on-machine development residue, the molecular weight of the low-molecular-weight polymeric compound is preferably 100 or more and less than 600, more preferably 300 or more and less than 600, and even more preferably 400 or more and less than 600.

[0405] When the polymeric compound includes low-molecular-weight polymeric compounds as polymeric compounds other than oligomers (the total amount when two or more low-molecular-weight polymeric compounds are included), from the viewpoints of chemical resistance, UV printing durability, and inhibition of on-machine development residues, the ratio of the oligomer to the low-molecular-weight polymeric compound (oligomer / low-molecular-weight polymeric compound) is preferably 10 / 1 to 1 / 10 by mass, more preferably 10 / 1 to 3 / 7, and even more preferably 10 / 1 to 7 / 3.

[0406] Furthermore, as a low-molecular-weight polymerizable compound, the polymerizable compound described in paragraphs 0082 to 0086 of International Publication No. 2019 / 013268 is preferred.

[0407] -Specific compound B2-

[0408] As a low-molecular-weight polymeric compound, it may contain a compound having one or two olefinic unsaturated groups (hereinafter also referred to as specific compound B2).

[0409] The preferred manner in which the olefinic unsaturated group in a particular compound B2 is the same as that in a particular compound B1 is the same.

[0410] Furthermore, from the viewpoint of suppressing the decrease in developability on the machine, the specific compound B2 is preferably a compound having two olefinic unsaturated bond groups (i.e., a 2-functional polymeric compound).

[0411] 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.

[0412] From the viewpoint of machine developability, it is preferable that the compound B2 contains an alkene structure or a carbamate bond.

[0413] 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.

[0414] Specific examples of a particular compound B2 are given below, but the particular 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.

[0415] [Chemical Formula 39]

[0416]

[0417] 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.

[0418] 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.

[0419] 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.

[0420] Furthermore, as a specific example of compound B2, one could cite difunctional methacrylates such as FST 510 manufactured by AZ Electronics.

[0421] 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.

[0422] From the viewpoint of machine developability and printing durability, the content of the specific compound B2 is preferably 1% to 60% by mass, more preferably 5% to 55% by mass, and even more preferably 5% to 50% by mass, relative to the total mass of the image recording layer.

[0423] When using a specific compound B2, the content of the specific compound B2 in the image recording layer relative to the total mass of the polymerizable compound is preferably 10% to 100% by mass, more preferably 50% to 100% by mass, and even more preferably 80% to 100% by mass.

[0424] The details of the polymeric compound's structure, whether it is used alone or in combination, the amount added, and other usage methods can be set arbitrarily.

[0425] From the perspective of UV printing durability, the image recording layer preferably contains two or more polymeric compounds.

[0426] The content of polymeric compounds (the total content of polymeric compounds when two or more polymeric compounds are included) is preferably 5% to 75% by mass, more preferably 10% to 70% by mass, and even more preferably 15% to 60% by mass, relative to the total mass of the image recording layer.

[0427] 〔particle〕

[0428] From the viewpoint of developability and UV printing durability, the image recording layer in this invention preferably contains particles. These particles can be inorganic or organic.

[0429] The particles preferably include organic particles, and more preferably resin particles.

[0430] 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.

[0431] <<Resin Particles>>

[0432] Examples of resin particles include particles containing addition-polymerizable resins (i.e., addition-polymerizable resin particles), particles containing addition-polymerizable resins (i.e., addition-polymerizable resin particles), and particles containing condensation-polymerizable resins (i.e., condensation-polymerizable resin particles), but addition-polymerizable resin particles or addition-polymerizable resin particles are preferred.

[0433] Furthermore, from the viewpoint that it can be thermally welded, the resin particles can be particles containing thermoplastic resin (i.e., thermoplastic resin particles).

[0434] Furthermore, the resin particles can be in the form of microcapsules, microgels (i.e., cross-linked resin particles), etc.

[0435] The resin particles are preferably selected from the group consisting of thermoplastic resin particles, thermally reactive resin particles, resin particles having polymerizable groups, microcapsules containing hydrophobic compounds, and microgels (crosslinked resin particles). Among these, resin particles having polymerizable groups are preferred.

[0436] In a particularly preferred embodiment, the resin particles contain at least one olefinically unsaturated group. The presence of these resin particles improves the printing durability of the exposed portion and the on-machine developability of the unexposed portion.

[0437] Thermoplastic resin 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.

[0438] Specific examples of resins constituting thermoplastic resin particles include homopolymers or copolymers 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.

[0439] From the viewpoint of ink adhesion and UV printing durability, resins containing constituent units formed of aromatic vinyl compounds and constituent units having nitrile groups are preferred as thermoplastic resin particles.

[0440] As for the aforementioned aromatic vinyl compounds, 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.

[0441] 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.

[0442] From the viewpoint of ink adhesion, the content of the constituent units formed by aromatic vinyl compounds is preferably greater than the content of the constituent units with nitrile groups described later, and is more preferably 15% to 85% by mass relative to the total mass of the thermoplastic resin, and even more preferably 30% to 70% by mass.

[0443] The nitrile-containing constituent units are preferably introduced using monomers having nitrile groups.

[0444] Acrylonitrile compounds are examples of monomers having a nitrile group, with (meth)acrylonitrile being a preferred example.

[0445] As a constituent unit having a nitrile group, a constituent unit formed of (meth)acrylonitrile is preferred.

[0446] From the viewpoint of ink adhesion, the content of the constituent units having nitrile groups is preferably less than the content of the constituent units formed by the above-mentioned aromatic vinyl compounds, and is more preferably 55% to 90% by mass, and more preferably 60% to 85% by mass, relative to the total mass of the resin.

[0447] Furthermore, when the resin contained in the thermoplastic resin particles comprises constituent units formed of aromatic vinyl compounds and constituent units having nitrile groups, the content ratio of constituent units formed of aromatic vinyl compounds to constituent units having nitrile groups (constituent units formed of aromatic vinyl compounds: constituent units having nitrile groups) is preferably 5:5 to 9:1 by mass, more preferably 6:4 to 8:2.

[0448] From the viewpoint of UV printing durability and chemical resistance, the resin contained in the thermoplastic resin particles preferably also has constituent units formed of N-vinyl heterocyclic compounds.

[0449] Examples of N-vinyl heterocyclic compounds include, for example, N-vinylpyrrolidone, N-vinylcarbazole, N-vinylpyrrole, N-vinylphenthiazide, N-vinylsuccinimide, N-vinylphthalimide, N-vinylcaprolactam and N-vinylimidazol, with N-vinylpyrrolidone being preferred.

[0450] The content of the constituent units formed by N-vinyl heterocyclic compounds is preferably 5% to 50% by mass, more preferably 10% to 40% by mass, relative to the total mass of the thermoplastic resin.

[0451] The resin contained in the thermoplastic resin particles may contain constituent units with acidic groups, but from the viewpoint of machine developability and ink adhesion, it is preferable that the constituent units do not contain acidic groups.

[0452] Specifically, the content of constituent units having acidic groups in the thermoplastic resin is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. The lower limit of the above content is not particularly limited and can be 0% by mass.

[0453] Furthermore, the acid value of the thermoplastic resin is preferably 160 mg KOH / g or less, more preferably 80 mg KOH / g or less, and even more preferably 40 mg KOH / g or less. The lower limit of the above acid value is not particularly limited and can be 0 mg KOH / g.

[0454] In this invention, the acid value is determined in accordance with the determination method of JIS K0070:1992.

[0455] From the perspective of ink adhesion, the resin contained in thermoplastic resin particles may contain constituent units that include hydrophobic groups.

[0456] Examples of hydrophobic groups include alkyl, aryl, and aralkyl groups.

[0457] As a constituent unit containing a hydrophobic group, it is preferred to form a constituent unit formed of an alkyl (meth)acrylate compound, an aryl (meth)acrylate compound, or an alkyl (meth)acrylate compound, and more preferably a constituent unit formed of an alkyl (meth)acrylate compound.

[0458] The content of the constituent units with hydrophobic groups in the resin contained in the thermoplastic resin particles is preferably 5% to 50% by mass, more preferably 10% to 30% by mass, relative to the total mass of the resin.

[0459] From the viewpoint of UV printing durability and machine developability, the thermoplastic resin contained in the thermoplastic resin particles preferably has hydrophilic groups.

[0460] As a hydrophilic group, there are no particular restrictions on the structure that is hydrophilic, but examples include acid groups such as carboxyl groups, hydroxyl groups, amino groups, nitrile groups, and polyepoxide structures.

[0461] From the viewpoint of UV printing durability and machine developability, the hydrophilic group is preferably a group having a polyepoxide structure, a group having a polyester structure, or a sulfonic acid group, more preferably a group having a polyepoxide structure or a sulfonic acid group, and even more preferably a group having a polyepoxide structure.

[0462] From the viewpoint of machine-developable properties, the poly(ethylene oxide), poly(propylene oxide), or poly(ethylene oxide / propylene oxide) structures are preferred as the aforementioned poly(ethylene oxide / propylene oxide) structures.

[0463] Furthermore, from the viewpoint of machine developability, among the aforementioned hydrophilic groups, as a polyepoxide structure, it is preferable to have a polyepoxide propylene structure, and more preferably a polyepoxide ethylene structure and a polyepoxide propylene structure.

[0464] From the viewpoint of machine developability, the number of epoxy structures in the above-mentioned polyepoxide structure is preferably 2 or more, more preferably 5 or more, even more preferably 5 to 200, and particularly preferably 8 to 150.

[0465] Furthermore, from the viewpoint of machine developability, the hydrophilic group described below is preferably the group represented by formula Z.

[0466] Among the hydrophilic groups possessed by thermoplastic resins, those represented by the following formula PO are preferred.

[0467] [Chemical Formula 40]

[0468]

[0469] In formula PO, L P Each independently represents an alkylene group, R P It represents a hydrogen atom or an alkyl group, and n represents an integer from 1 to 100.

[0470] In formula PO, L P Each of the following is preferably ethylene, 1-methylethylene, or 2-methylethylene, and more preferably ethylene.

[0471] In formula PO, R P Preferably, it is an alkyl group having 1 to 18 hydrogen atoms or carbon atoms, more preferably an alkyl group having 1 to 10 hydrogen atoms or carbon atoms, even more preferably an alkyl group having 1 to 4 hydrogen atoms or carbon atoms, and especially preferably a hydrogen atom or a methyl group.

[0472] In formula PO, n is preferably an integer from 1 to 10, and more preferably an integer from 1 to 4.

[0473] The content of constituent units having hydrophilic groups is preferably 5% to 60% by mass, more preferably 10% to 30% by mass, relative to the total mass of the resin.

[0474] The resin contained in the thermoplastic resin particles may also contain other constituent units. As other constituent units, it is not particularly limited to include constituent units other than those mentioned above, for example, constituent units formed from acrylamide compounds, vinyl ether compounds, etc.

[0475] The content of other constituent units of the resin contained in the thermoplastic resin particles is preferably 5% to 50% by mass, more preferably 10% to 30% by mass, relative to the total mass of the resin.

[0476] Examples of thermo-reactive resin particles include resin particles with thermo-reactive groups. Thermo-reactive resin particles form hydrophobic regions through cross-linking based on thermal reactions and changes in functional groups during cross-linking.

[0477] The thermally reactive groups in resin 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, methacryloyl, vinyl, allyl, etc.) that undergo free radical polymerization, cationic polymerizable groups (e.g., vinyl, ethyleneoxy, epoxy, oxetyl, etc.), isocyanate groups or their blocks, epoxy groups, ethyleneoxy groups, and functional groups having active hydrogen atoms as the target of these reactions (e.g., amino, hydroxyl, carboxyl, etc.) that undergo addition reactions, carboxyl groups and hydroxyl or amino groups as the target of the reaction that undergo condensation reactions, and acid anhydrides and amino or hydroxyl groups as the target of the reaction that undergo ring-opening addition reactions.

[0478] The resin having the above-mentioned thermally reactive groups can be an addition polymer, an addition polymerization resin, or a condensation polymerization resin, or it can be a thermoplastic resin.

[0479] As microcapsules, for example, microcapsules containing at least a portion of the components of an image recording layer (preferably hydrophobic compounds) as described in Japanese Patent Application Publications Nos. 2001-277740 and 2001-277742 are preferred. A preferred embodiment of an image recording layer containing microcapsules as resin particles is a structure in which the hydrophobic component (i.e., hydrophobic compound) of the image recording layer is contained within the microcapsule, and a hydrophilic component (i.e., hydrophilic compound) is contained on the exterior of the microcapsule.

[0480] Microgels (cross-linked resin 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 lithographic printing plate original and the printing durability of the obtained lithographic printing plate, reactive microgels having polymerizable groups on their surface are preferred.

[0481] To obtain microcapsules containing the components of an image recording layer, known synthetic methods can be applied.

[0482] Microgels (cross-linked resin 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 lithographic printing plate original and the printing durability of the obtained lithographic printing plate, reactive microgels having polymerizable groups on their surface are preferred.

[0483] To obtain microgels containing components of an image recording layer, known synthetic methods can be applied.

[0484] From the viewpoint of the printing durability, stain resistance and storage stability of the obtained lithographic printing plate, addition polymeric resin 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.

[0485] As the aforementioned polyphenolic compounds, compounds having multiple benzene rings with phenolic hydroxyl groups are preferred.

[0486] As the 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. Furthermore, water can be used as the aforementioned active hydrogen compound. When water is used, the amine generated by the reaction of the isocyanate group with water can form a urea bond, thereby forming particles.

[0487] 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 resin particles described in paragraphs 0230 to 0234 of International Publication No. 2018043259 are preferred examples.

[0488] Furthermore, from the viewpoint of the printability and solvent resistance of the obtained lithographic printing plate, addition polymerizable resin particles having a hydrophobic backbone and comprising both i) a constituent unit having a nitrile group directly bonded to the aforementioned hydrophobic backbone and ii) a constituent unit having a side group comprising a hydrophilic polyoxyalkylene segment are preferred. Specifically, the particles described in paragraph 0156 of Japanese Patent Application Publication No. 2019-64269 are preferred.

[0489] <<Groups represented by formula Z>>

[0490] The resin particles in this invention preferably have a group represented by the following formula Z as a hydrophilic group.

[0491] *-QWY formula Z

[0492] 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.

[0493] Furthermore, the hydrophilic structures included in preferred formula Z all contain polyepoxide structures.

[0494] 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.

[0495] 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.

[0496] The divalent group with a hydrophilic structure in W of formula Z above is preferably a group containing a polyepoxide structure, preferably a polyalkoxide group or a polyalkoxide group with -CH2CH2NR bonded to one end. W - group. Additionally, R W It represents a hydrogen atom or an alkyl group.

[0497] 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), or an aryl group with 6 to 120 carbon atoms.

[0498] The monovalent group with a hydrophilic structure in Y of formula Z 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. WThe group is a monovalent group with a hydrophilic structure. Preferably, it is a group containing a polyepoxide structure, and preferably has -CH2CH2N(R) bonded to the other end of either a polyalkoxide group with a hydrogen atom or an alkyl group at the end. W )- groups.

[0499] 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 6 to 120 carbon atoms, an aralkyl group with 6 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.

[0500] In resin particles having groups represented by the above formula Z, from the viewpoint of print durability, 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 group at the end.

[0501] In addition, the group represented by formula Z can function as a dispersing group to improve the dispersibility of resin particles.

[0502] From the viewpoint of print durability and machine developability, the resin particles in this invention preferably have polymerizable groups (preferably olefinically unsaturated groups), and more preferably include resin particles having polymerizable groups, particularly on their surface. By using resin particles with polymerizable groups, plate wear (preferably UV plate wear) is easily suppressed, and print durability (preferably UV print durability) is also improved.

[0503] From the viewpoint of print durability, the resin particles in this invention are preferably resin particles having hydrophilic groups and polymeric groups.

[0504] 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.

[0505] As for the polymerizable group mentioned above, there are no particular restrictions as long as it is a polymerizable group, but from the viewpoint of reactivity, olefinic unsaturated groups are preferred, vinylphenyl (styrene), (meth)acryloyloxy or (meth)acrylamido groups are more preferred, and (meth)acryloyloxy is especially preferred.

[0506] Furthermore, the resin constituting the resin particles having polymerizable groups preferably has constituent units having polymerizable groups.

[0507] In addition, polymeric groups can be introduced onto the surface of resin particles through polymer reactions.

[0508] Furthermore, from the viewpoints of print durability, ink adhesion, machine developability, and suppression of developer residue during machine development, the resin particles preferably comprise an addition-polymerized resin having urea bonds, more preferably an addition-polymerized resin having a structure obtained by reacting at least an isocyanate compound represented by the following formula (Iso) with water, and particularly preferably an addition-polymerized 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 polyoxyalkylene structures. Furthermore, particles comprising the addition-polymerized resin having the aforementioned urea bonds are preferably microgels.

[0509] [Chemical Formula 41]

[0510]

[0511] In the formula (Iso), n represents an integer from 0 to 10.

[0512] 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 a 4,4-isomer is used.

[0513] 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 aqueous solution hydrolyzes to produce an amino group. The resulting amino group reacts with the isocyanate groups to form a urea bond, thus forming a dimer. Furthermore, by repeating the following reaction, an addition-polymerized resin containing urea bonds is formed.

[0514] Furthermore, in the following reaction, by adding compounds such as alcohol compounds and amine compounds that are reactive with isocyanate groups (compounds with active hydrogen), it is also possible to introduce the structure of alcohol compounds, amine compounds, etc. into addition polymeric resins containing urea bonds.

[0515] As a compound having the aforementioned active hydrogen, a compound having the described active hydrogen is preferably mentioned.

[0516] [Chemical Formula 42]

[0517]

[0518] Furthermore, the addition polymeric resin having the aforementioned urea bond preferably has an olefin unsaturated group, and more preferably has a group represented by the following formula (PETA).

[0519] [Chemical Formula 43]

[0520]

[0521] In the formula (PETA), the wavy line represents the bonding location with other structures.

[0522] Synthesis of Resin Particles

[0523] There are no particular limitations on the method for synthesizing resin particles, as long as it is possible to synthesize particles using any of the various resins described above. Examples of known methods for synthesizing resin particles include emulsion polymerization, suspension polymerization, dispersion polymerization, soap-free polymerization, and microemulsion polymerization.

[0524] In addition, known methods such as microcapsule synthesis and microgel (cross-linked resin particles) synthesis can be used in the synthesis of resin particles.

[0525] <<Average particle size>>

[0526] The average particle size 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.

[0527] The average particle size was determined by light scattering or by taking electron micrographs of the particles. The particle size of a total of 5,000 particles was measured on the micrographs, and the average value was calculated. Additionally, for non-spherical particles, the equivalent diameter of the circle of the particles in the micrographs was used.

[0528] In addition, unless otherwise specified, the average particle size of the particles in this invention is the volume average particle size.

[0529] The particles (preferably resin particles) may be of only one type or in combination of two or more types.

[0530] From the viewpoint of developability and printing durability, the content of particles (preferably resin particles) relative to the total mass of 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.

[0531] [Other ingredients]

[0532] The image recording layer in this invention may contain other components besides those already described.

[0533] Other components include adhesive polymers, color developers, chain transfer agents, low molecular weight hydrophilic compounds, sensitizers, and other additives.

[0534] Other components include colorants, printing agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic particles, and low molecular weight hydrophilic compounds disclosed in Japanese Patent Application Publication No. 2009-255434, paragraphs 0181 to 0190.

[0535] Furthermore, other compounds include hydrophobic precursors (which can convert the image recording layer into hydrophobic particles when heated), low molecular weight hydrophilic compounds, sensitizers (e.g., phosphonium compounds, nitrogen-containing low molecular weight compounds, ammonium-containing polymers), and chain transfer agents disclosed in Japanese Patent Application Publication No. 2012-187907, paragraphs 0191 to 0217.

[0536] -Adhesive Polymer-

[0537] Depending on the requirements, the image recording layer may contain an adhesive polymer.

[0538] Here, adhesive polymers refer to polymers other than resin particles, that is, polymers that are not in particle shape.

[0539] Furthermore, this excludes ammonium salt polymers in adhesive polymers, sensitizers, and polymers used as surfactants.

[0540] The adhesive polymer can preferably be a known adhesive polymer used in the image recording layer of the lithographic printing plate original (e.g., (meth)acrylic resin, polyvinyl acetal, polyurethane resin, etc.).

[0541] As an example, the adhesive polymer used in the original of the machine-developable lithographic printing plate (hereinafter also referred to as the adhesive polymer for machine development) is described in detail.

[0542] 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 poly(epoxy) sites 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 blocks composed of repeating units containing poly(epoxy) and blocks composed of repeating units not containing (epoxy).

[0543] When the main chain has poly(epoxy) sites, polyurethane resin is preferred.

[0544] 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.

[0545] Furthermore, as another preferred example of an adhesive polymer, a polymeric compound having a core of a polyfunctional thiol with 6 or more functions and less than 10 functions, and having a polymer chain bonded to the core via a thioether bond, and wherein the polymer chain has polymerizable groups (hereinafter also referred to as a star polymeric compound).

[0546] As a star-shaped polymer compound, for example, the compound described in Japanese Patent Application Publication No. 2012-148555 can be preferred.

[0547] Regarding star-shaped polymer compounds, examples include compounds that have polymeric 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. The polymeric groups present in the star-shaped polymer compound form crosslinks between the molecules of the compound, promoting curing.

[0548] As polymerizable groups, olefinic unsaturated groups such as (meth)acrylate, vinyl, allyl, and vinylphenyl (styrene) and epoxy groups are preferred. From the viewpoint of polymerization reactivity, (meth)acrylate, vinyl, and vinylphenyl (styrene) are more preferred, and (meth)acrylate is particularly preferred. These groups can be introduced into the polymer through polymer reactions or copolymerization. Specifically, for example, the reaction of a polymer having a carboxyl group on its side chain with glycidyl methacrylate, or the reaction of a polymer having an epoxy group with a carboxylic acid containing an olefinic unsaturated group such as methacrylic acid, can be used.

[0549] 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.

[0550] As an adhesive polymer, it can be used in combination with hydrophilic polymers such as polyacrylic acid, polyvinyl alcohol, and polyvinyl acetal as described in Japanese Patent Application Publication No. 2008-195018, as needed. Furthermore, it can also be used in combination with lipophilic and hydrophilic polymers.

[0551] From the viewpoint of machine developability, the image recording layer preferably comprises polyvinyl acetal. Examples of polyvinyl acetal include, for instance, polyvinyl butyral.

[0552] Polyvinyl alcohol acetal is a resin obtained by acetalizing the hydroxyl groups of polyvinyl alcohol with aldehydes.

[0553] In particular, polyvinyl butyral obtained by acetalizing the hydroxyl groups of polyvinyl alcohol with butyraldehyde (i.e., butyraldehyde) is preferred.

[0554] Polyvinyl acetal preferably comprises the constituent unit represented by (a) below by acetalizing the hydroxyl groups of polyvinyl alcohol with an aldehyde.

[0555] [Chemical Formula 44]

[0556]

[0557] Here, R represents the aldehyde residue used for acetalization.

[0558] In addition to hydrogen atoms and alkyl groups, R can also be an olefinic unsaturated group, which will be discussed later.

[0559] 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% relative to all constituent units (total ethylidene in the main chain) of polyvinyl acetal, more preferably 55 mol% to 85 mol%, and even more preferably 55 mol% to 80 mol%.

[0560] 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.

[0561] Furthermore, the content of each constituent unit in polyvinyl acetal described later is also the same.

[0562] From the perspective of improving printability, polyvinyl acetal preferably has olefinic unsaturated groups.

[0563] 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 preferable 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.

[0564] From the viewpoint of improving print durability, polyvinyl acetal preferably contains constituent units having olefinic unsaturated groups.

[0565] 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.

[0566] 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.

[0567] 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.

[0568] [Chemical Formula 45]

[0569]

[0570] 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 called acrylate content) is preferably 1 mol% to 15 mol% relative to all constituent units of polyvinyl acetal, more preferably 1 mol% to 10 mol%.

[0571] 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.

[0572] As a constituent unit having a hydroxyl group, the constituent unit represented by (b) below can be cited.

[0573] [Chemical Formula 46]

[0574]

[0575] As for the content of the constituent units represented by (b) above (also known as the amount of hydroxyl groups), 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%.

[0576] As described above, polyvinyl acetal may also contain other constituent units.

[0577] Other constituent units, for example, include constituent units having an acetyl group, and more specifically, constituent units represented by (c) below.

[0578] [Chemical Formula 47]

[0579]

[0580] As the content of the constituent unit represented by (c) above (also known as the acetyl content), it is preferably 0.5 mol% to 10 mol% relative to all the constituent units of polyvinyl acetal, more preferably 0.5 mol% to 8 mol%, and even more preferably 1 mol% to 3 mol%.

[0581] 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.

[0582] 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.

[0583] The weight-average molecular weight of the above-mentioned polyvinyl acetal is preferably 18,000 to 150,000.

[0584] 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 .

[0585] Here, the "solubility parameter (unit: (MPa)" in this invention is... 1 / 2 The solubility parameter is Hansen.

[0586] 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 called the SP value), and is calculated using the following formula.

[0587] δ(MPa) 1 / 2 =(δd 2 +δp 2 +δh 2 ) 1 / 2

[0588] 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).

[0589] 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.

[0590] 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.

[0591] 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).

[0592] 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.

[0593] 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%.

[0594] [Chemical Formula 48]

[0595]

[0596] As the aforementioned polyvinyl acetal, commercially available products can be used.

[0597] 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.).

[0598] Adhesive polymers can be used alone or in combination with two or more.

[0599] The adhesive polymer can be included in the image recording layer in any amount, but the content of the adhesive polymer is preferably 1% to 90% by mass, more preferably 5% to 80% by mass, relative to the total mass of the image recording layer.

[0600] -Color developer-

[0601] The image recording layer in this invention preferably contains a color developer, more preferably an acid color developer. Furthermore, as the color developer, a colorless compound is preferred.

[0602] 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, colorless compounds having partial skeletons such as lactones, lactams, sulopentalides, spiropyrans, esters, or amides are particularly preferred, and these partial skeletons rapidly undergo ring-opening or cleavage upon contact with an electron-accepting compound.

[0603] Examples of such acid colorimetric reagents include the compounds described in paragraphs 0184 to 0191 of Japanese Patent Application Publication No. 2019-18412.

[0604] From a visual recognition point of view, the colorimetric agent used in this invention is preferably at least one compound selected from the group consisting of spiropyran compounds, spiroxazine compounds, spironolactone compounds, and spironolactam compounds.

[0605] From a visibility point of view, the hue of the pigment after color development preferably has a maximum absorption wavelength in the range of 450–650 nm. As for the color tone, red, purple, blue, or dark green are preferred.

[0606] Furthermore, from the viewpoint of visual recognizability and the visual recognizability of the exposed part, the aforementioned acid developer is preferably a colorless pigment.

[0607] 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 helical structure, and more preferably a spironolactone ring structure.

[0608] Furthermore, from the viewpoint of visual recognizability and the visual recognizability of the exposed part, the colorless pigment described above is preferably a colorless pigment having a phthaloyl structure or a fluorescent yellow matrix structure.

[0609] Furthermore, from the viewpoint of visual recognizability and the visual recognizability of the exposed part, the 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).

[0610] [Chemical Formula 49]

[0611]

[0612] 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 dialkylaniline group, 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.

[0613] From the viewpoint of visual recognizability and the visual recognizability of the exposed part, 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 amino, alkylamino, arylamino, dialkylamino, monoalkylmonoarylamino, diarylamino, alkoxy or aryloxy, and even more preferably arylamino, monoalkylmonoarylamino or diarylamino, especially arylamino or monoalkylmonoarylamino.

[0614] From the viewpoint of visual recognizability and the 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.

[0615] From the perspective of visual recognizability and the visual recognizability of the exposed part, X5~X in formula (Le-2) or formula (Le-3) 10Each 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.

[0616] From the viewpoint of visual recognizability and the 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.

[0617] From the viewpoint of visual recognizability and the visual recognizability of the exposed part, Ra1 in formula (Le-3) is preferably alkyl or alkoxy, more preferably alkoxy, and especially preferably methoxy.

[0618] From the viewpoint of visual recognizability and the visual recognizability of the exposed part, Rb1 to Rb4 in formula (Le-1) are each preferably hydrogen atoms or alkyl groups, more preferably alkyl groups, and especially preferably methyl groups.

[0619] Furthermore, from the viewpoint of visual recognizability and the 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).

[0620] [Chemical Formula 50]

[0621]

[0622] 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 dialkylaniline 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.

[0623] 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.

[0624] Furthermore, from the viewpoint of visual recognizability and the visual recognizability of the exposed part, the 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).

[0625] [Chemical Formula 51]

[0626]

[0627] In formulas (Le-7) to (Le-9), X1 to X4 independently represent hydrogen atoms, halogen atoms, or dialkylaniline groups, Y1 and Y2 independently represent C or N, X1 does not exist when Y1 is N, and X4 does not exist when Y2 is N, Ra1 to Ra4 independently represent hydrogen atoms, alkyl or alkoxy groups, Rb1 to Rb4 independently represent hydrogen atoms, alkyl or aryl groups, and Rc1 and Rc2 independently represent aryl groups.

[0628] 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.

[0629] From the viewpoint of visual recognizability and the visual recognizability of the exposed part, Ra1 to Ra4 in formula (Le-7) are each preferably alkyl or alkoxy, more preferably alkoxy, and especially preferably methoxy.

[0630] From the viewpoint of visual recognizability and the visual recognizability of the exposed part, Rb1 to Rb4 in formulas (Le-7) to (Le-9) are each independently preferred to be an aryl group substituted with a hydrogen atom, an alkyl group, or an alkyl or alkoxy group, more preferably a hydrogen atom or an alkyl group, and especially preferably a hydrogen atom or a methyl group.

[0631] From the viewpoint of visual recognizability and the visual recognizability of the exposed part, Rc1 and Rc2 in formula (Le-8) are preferably phenyl or alkylphenyl, and more preferably phenyl.

[0632] Furthermore, in formula (Le-8), from the viewpoint of visual recognizability and the visual recognizability of the exposed part, it is preferable that X1 to X4 are hydrogen atoms and Y1 and Y2 are C atoms.

[0633] Furthermore, in formula (Le-8), from the viewpoint of visual recognizability and the visual recognizability of the exposed part, 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.

[0634] The alkyl groups in formulas (Le-1) to (Le-9) can be straight chains, branched chains, or ring structures.

[0635] 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.

[0636] 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.

[0637] Furthermore, the monovalent organic groups, alkyl, aryl, dialkylaniline, alkylamino, alkoxy, and other groups in formulas (Le-1) to (Le-9) can have substituents. Examples of substituents include alkyl, aryl, halogen, amino, alkylamino, arylamino, dialkylamino, monoalkylmonarylamino, diarylamino, hydroxyl, alkoxy, aryloxy, acyl, alkoxycarbonyl, aryloxycarbonyl, and cyano. Moreover, these substituents can be further replaced by other substituents.

[0638] The following compounds are examples of colorless pigments having a phthalide structure or a fluorescent yellow parent structure that are preferred for use.

[0639] [Chemical Formula 52]

[0640]

[0641] [Chemical Formula 53]

[0642]

[0643] [Chemical Formula 54]

[0644]

[0645] [Chemical Formula 55]

[0646]

[0647] [Chemical Formula 56]

[0648]

[0649] 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.

[0650] From the viewpoint of visual recognizability and the visual recognizability of the exposed part, the following compounds can be cited as preferred colorless pigments.

[0651] [Chemical Formula 57]

[0652]

[0653] These color developers can be used alone or in combination with two or more components.

[0654] The content of the developer relative to the total mass of the image recording layer is preferably 0.5% to 10% by mass, more preferably 1% to 5% by mass.

[0655] -Formation of the image recording layer-

[0656] The image recording layer in the lithographic printing plate original involved in this invention 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, and then applying the coating liquid onto a support using a known method such as bar coating and drying. The coating amount (solid content) of the coated and dried image recording layer varies depending on the application, but is preferably 0.3 g / m². 2 ~3.0g / m 2 Within this range, good sensitivity and good film properties of the image recording layer can be obtained.

[0657] 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 1% to 50% by mass.

[0658] 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 .

[0659] Furthermore, the thickness of the image recording layer in the lithographic printing plate original involved in this invention is preferably 0.1 μm to 3.0 μm, more preferably 0.3 μm to 2.0 μm.

[0660] In this invention, the film thickness of each layer in the lithographic printing plate original is confirmed by making a slice cut along a direction perpendicular to the surface of the lithographic printing plate original and observing the cross-section of the slice using a scanning electron microscope (SEM).

[0661] <Outermost layer>

[0662] The on-machine developing type lithographic printing plate master involved in this invention has a support, an image recording layer and an outermost layer in sequence, wherein the outermost layer contains a color-changing compound.

[0663] Furthermore, the outermost layer mentioned above is the outermost layer on the image recording layer side of the support in the machine-developed lithographic printing plate original.

[0664] In addition to inhibiting the image formation barrier reaction by blocking oxygen, the outermost layer can also prevent scratches in the image recording layer and prevent ablation during high-intensity laser exposure.

[0665] -Color-changing compounds-

[0666] Furthermore, the outermost layer contains a color-changing compound.

[0667] In addition to the color-changing compound, the outermost layer may also contain other components such as water-soluble polymers, hydrophobic polymers, sensitizers, acid-producing agents, and infrared absorbers. Preferably, it contains color-changing compounds and water-soluble polymers, and more preferably, it contains color-changing compounds, water-soluble polymers, and hydrophobic polymers.

[0668] 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 When the energy density is exposed to infrared light with a wavelength of 830 nm, the change in brightness ΔL before and after exposure is preferably 2.0 or more, 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.

[0669] As an upper limit for the change in brightness ΔL, for example, 20.0 can be cited.

[0670] Furthermore, especially in the case of having an outermost layer containing a color-changing compound, it is preferable to satisfy the aforementioned preferred numerical range of the lightness change ΔL.

[0671] The change in lightness ΔL was measured using the following method.

[0672] The Luxel PLATESETTER T-9800, manufactured by FUJIFILM Graphic Systems Co., Ltd., equipped with an 830nm infrared semiconductor laser, achieved an output of 99.5%, an outer drum speed of 220rpm, and a resolution of 2,400dpi (dots per inch, 1 inch = 25.4mm) (energy density of 110mJ / cm²). 2 The original offset printing plate is exposed under the following conditions. Exposure is performed at 25°C and 50% RH.

[0673] The brightness change of the original lithographic printing plate before and after exposure was measured.

[0674] The measurements were performed using an eXact spectrochromatic meter manufactured by X-Rite Inc. Using L... * a * b * L in color scheme * Value (brightness), which determines the L value of the exposed area. * The value of L is related to the exposed or unexposed portion before exposure. * The absolute value of the difference in values ​​is taken as the change in brightness ΔL.

[0675] 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.

[0676] 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.

[0677] 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.

[0678] As a color-changing compound, it is preferable to include a compound that develops color upon exposure to infrared light.

[0679] Furthermore, as a color-changing compound, it is preferable to include a decomposable compound that decomposes due to infrared exposure, wherein it is more preferably a decomposable compound that decomposes through heat, electron transfer or both caused by infrared exposure.

[0680] 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 caused by infrared exposure or both), 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.

[0681] 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) by infrared exposure are transferred within the molecule to electron-accepting groups (groups with potential close to the LUMO), resulting in decomposition.

[0682] The following describes a decomposing compound as an example of a color-changing compound.

[0683] 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 with a very large absorption wavelength in the 750 nm to 1,400 nm wavelength region are preferred.

[0684] 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.

[0685] 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 Formulas 1-1 to 1-7 below). 1 () anthocyanins.

[0686] 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.

[0687] [Chemical Formula 58]

[0688]

[0689] In Equation 1-1, R 1 R represents a group represented by any one of the following formulas 2-1 to 4-1. 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 10It represents a hydrogen atom, alkyl group, or aryl group; Za represents a counterion that neutralizes the charge.

[0690] [Chemical Formula 59]

[0691]

[0692] In equations 2-1 to 4-1, 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.

[0693] 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.

[0694] In Equation 1-1, R 1 It represents any one of the groups represented by formulas 2-1 to 4-1 above.

[0695] The groups represented by Formula 2-1, Formula 3-1, and Formula 4-1 will be explained below.

[0696] In Equation 2-1, 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.

[0697] As a result of R 20 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.

[0698] The alkyl groups mentioned above can be straight-chain, branched, or have a cyclic structure.

[0699] 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.

[0700] As R 20 From the point of view of visual recognizability, alkyl groups are preferred.

[0701] Furthermore, from the perspective of visual recognizability and color rendering, as a result 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.

[0702] Moreover, from the perspective of decomposition and visual recognition, as a product of R 20 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.

[0703] Hereinafter, specific examples of groups represented by Formula 2-1 above will be 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.

[0704] [Chemical Formula 60]

[0705]

[0706] In Equation 3-1, 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.

[0707] As a result of R 30 The alkyl and aryl groups represented are related to R in formula 2-1. 20 The alkyl and aryl groups are represented by the same terms, and the preferred methods are also the same.

[0708] From the perspective of visual recognition and color rendering, 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.

[0709] Furthermore, from the perspective of decomposition and visual recognition, as a result 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.

[0710] Moreover, from the perspective of decomposition and visual recognition, 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.

[0711] From the perspectives of decomposition and visual recognition, 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).

[0712] Hereinafter, specific examples of groups represented by Formula 3-1 above will be 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.

[0713] [Chemical Formula 61]

[0714]

[0715] In Equation 4-1, 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.

[0716] 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.

[0717] As R 41 From the viewpoints of decomposability and visual recognizability, alkyl groups are preferred.

[0718] As R 42 From the viewpoints of decomposability and visual recognizability, alkyl groups are preferred.

[0719] From the perspective of decomposition and visual recognition, 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.

[0720] From the perspective of visual recognition and color rendering, 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.

[0721] Furthermore, from the perspective of decomposition and visual recognition, as a result 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.

[0722] Regarding Zb in Formula 4-1, 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.

[0723] 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.

[0724] Hereinafter, specific examples of groups represented by Formula 4-1 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.

[0725] [Chemical Formula 62]

[0726]

[0727] In Equation 1-1, L is preferably an oxygen atom or -NR. 10 - Oxygen atoms are particularly preferred.

[0728] 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.

[0729] Among the alkyl groups, methyl or cyclohexyl is preferred.

[0730] 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.

[0731] 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 .

[0732] 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.

[0733] The aforementioned hydrocarbon groups can be straight-chain, branched, or have a ring structure.

[0734] Alkyl groups are particularly preferred as the aforementioned hydrocarbon groups.

[0735] 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.

[0736] The alkyl groups mentioned above can be straight-chain, branched, or have a cyclic structure.

[0737] 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.

[0738] Among the alkyl groups, methyl, ethyl, propyl or butyl are preferred.

[0739] The alkyl groups mentioned above may have substituents.

[0740] Examples of substituents include alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, carboxylic acid ester, sulfonyl, sulfonate, alkoxycarbonyl, aryloxycarbonyl, and groups formed by combining them.

[0741] 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.

[0742] 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.

[0743] Furthermore, in A1 + R bonded to the bonded carbon atom 12 Preferred and R 15 or R 16 (preferably 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 (preferably R) 18 They are connected to form a ring.

[0744] In Equation 1-1, n is preferred. 13 R is 1. 16 -R a (i.e., hydrocarbon group).

[0745] 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.

[0746] In Equation 1-1, n is preferred. 14 R is 1. 18 -R a (i.e., hydrocarbon group).

[0747] 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.

[0748] 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.

[0749] 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.

[0750] 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.

[0751] 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).

[0752] [Chemical Formula 63]

[0753]

[0754] -R W2 -CO2M (a2)

[0755] -R W3 -PO3M2 (a3)

[0756] -R W4 -SO3M (a4)

[0757] In equations (a1) to (a4), R WO 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 R W5 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.

[0758] In equation (a1), as a result of R WO 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.

[0759] n W1 Preferably 1 to 10, more preferably 1 to 5, and especially preferably 1 to 3.

[0760] 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.

[0761] 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.

[0762] 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.

[0763] [Chemical Formula 64]

[0764]

[0765] In equations (a2) to (a4), as R W2 ~R W4Specific 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.

[0766] In equation (a3), there are two M values ​​that can be the same or different.

[0767] In formulas (a2) to (a4), examples of ononium groups represented by M include ammonium, iodonium, phosphonium, and sulfonium groups.

[0768] 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 Al. + It can also be R in Equation 1-1 1 -L can contain cations.

[0769] Among the groups represented by formulas (a1) to (a4), groups represented by formulas (a1), (a2), or (a4) are preferred.

[0770] 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.

[0771] In Formula 1-1, A1 and A2 independently represent oxygen, sulfur, or nitrogen atoms, with nitrogen atoms being preferred.

[0772] In Formula 1-1, A1 and A2 are preferably the same atoms.

[0773] In Equation 1-1, Za represents the counter ion that neutralizes the charge.

[0774] 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.

[0775] 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.

[0776] 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.

[0777] 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.

[0778] 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.

[0779] [Chemical Formula 65]

[0780]

[0781] In Equation 1-2, R 1 R represents any one of the groups represented by formulas 2-1 to 4-1 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.

[0782] R in Equation 1-2 1 R in Equation 1-11 The meanings are the same, and the preferred selection methods are also the same.

[0783] 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.

[0784] More specifically, R 19 and R 21 Preferably hydrogen atoms or -R a .

[0785] Furthermore, R 20 and R 22 Preferably hydrogen atoms, -R a 、-OR b Or -CN.

[0786] As a result of R 19 ~R 22 -R indicates a Preferably alkyl or alkenyl groups.

[0787] 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.

[0788] As R 19 With R 20 or R 21 With R 22 Examples of rings formed by linkages include benzene rings and naphthalene rings.

[0789] In Equation 1-2, R is preferred. 23 With R 24 They can be linked together to form single or multiple rings.

[0790] 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.

[0791] 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.

[0792] Examples of unsubstituted alkyl groups include those with 1 to 4 carbon atoms, with methyl being preferred.

[0793] 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.

[0794] 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.

[0795] Furthermore, from the viewpoint of in-machine developability, W 1 and W 2 Each is preferably 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.

[0796] Za represents a counterion that neutralizes the charge within a molecule.

[0797] 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 more than two anionic structures, Za can also become a counter cation.

[0798] 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.

[0799] 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.

[0800] From the viewpoint of decomposability and visual recognizability, anthocyanins, as decomposable compounds, are further preferably compounds represented by any one of the following formulas 1-3 to 1-7.

[0801] In particular, from the viewpoint of decomposability and visual recognizability, compounds represented by any one of Formulas 1-3, 1-5 and 1-6 are preferred.

[0802] [Chemical Formula 66]

[0803]

[0804] In equations 1-3 to 1-7, R 1 R represents any one of the groups represented by formulas 2-1 to 4-1 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.

[0805] 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 2 The meanings of L and L are the same, and the preferred selection methods are also the same.

[0806] 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.

[0807] The following are specific examples of anthocyanins that are decomposable compounds, but the present invention is not limited to these.

[0808] [Chemical Formula 67]

[0809]

[0810] Furthermore, as a decomposable compound, anthocyanin is preferably an infrared-absorbing compound as described in International Publication No. 2019 / 219560.

[0811] Furthermore, the aforementioned color-changing compounds may contain acid color-developing agents.

[0812] 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.

[0813] Color-changing compounds can be used alone or in combination with two or more components.

[0814] As a chromogenic compound, it can be used in combination with the decomposition compounds already described and the acid-producing agents described later.

[0815] From a visual recognition point of view, the content of the color-changing compound in the outermost 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 outermost layer.

[0816] From a visual recognition perspective, the content M of the aforementioned outermost layer of the color-changing compound is... 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.

[0817] -Water-soluble polymer-

[0818] From the viewpoint of developability (more preferably machine developability), the outermost layer preferably comprises a water-soluble polymer.

[0819] 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.

[0820] Examples of water-soluble polymers used in the outermost layer include polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, water-soluble cellulose derivatives, polyethylene glycol, and poly(meth)acrylonitrile.

[0821] 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.

[0822] 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 as the water-soluble polymer.

[0823] 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%.

[0824] The above degree of saponification can be determined according to the method described in JIS K 6726:1994.

[0825] Polyvinylpyrrolidone is a preferred example of the aforementioned water-soluble polymer.

[0826] As a water-soluble polymer, polyvinyl alcohol and polyvinylpyrrolidone are also preferably used in combination.

[0827] Water-soluble polymers can be used alone or in combination of two or more.

[0828] When the outermost layer contains a water-soluble polymer, the content of the water-soluble polymer relative to the total mass of the outermost layer is preferably 1% to 99% by mass, more preferably 3% to 97% by mass, and even more preferably 5% to 95% by mass.

[0829] -Other ingredients-

[0830] In addition to the color-changing compounds and water-soluble polymers already described, the outermost layer may also contain other components such as hydrophobic polymers, sensitizers, acid-producing agents, and infrared absorbers.

[0831] The other ingredients are described below.

[0832] <<Hydrophobic Polymers>>

[0833] The outermost layer preferably comprises a hydrophobic polymer.

[0834] Hydrophobic polymers are polymers that dissolve less than 1g or are insoluble in 100g of pure water at 70°C.

[0835] Examples of hydrophobic polymers include polyethylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, alkyl poly(meth)acrylates (e.g., poly(meth)acrylate, poly(ethyl)acrylate, poly(butyl)acrylate, etc.), and copolymers obtained by combining the raw material monomers of these polymers.

[0836] Furthermore, as a hydrophobic polymer, polyvinylidene chloride resin is preferred.

[0837] Furthermore, as a hydrophobic polymer, it is preferable to include a styrene-acrylic acid copolymer.

[0838] Furthermore, from the viewpoint of machine developability, hydrophobic polymers are preferably hydrophobic polymer particles.

[0839] Hydrophobic polymers can be used alone or in combination of two or more.

[0840] When the outermost 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 outermost layer.

[0841] <<Acid-producing agents>>

[0842] When the outermost layer uses an acid-based color-changing agent as the color-changing compound, it is preferable to include an acid-generating agent.

[0843] 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.

[0844] 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.

[0845] Specifically, from the viewpoint of sensitivity and stability, onium salt compounds are preferred as acid-producing agents.

[0846] 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.

[0847] Among them, triarylsulfonium or diaryliodonium, sulfonates, carboxylates, and BPh4 are preferred. - BF4 - PF6 - ClO4 - etc. Here, Ph represents phenyl.

[0848] Acid-producing agents can be used alone or in combination of two or more.

[0849] When the outermost layer contains an acid-producing agent, the content of the acid-producing agent is preferably 0.5% to 30% by mass, more preferably 1% to 20% by mass, relative to the total mass of the outermost layer.

[0850] In addition to the components already described, the outermost layer may also contain known additives such as sensitizers, inorganic layered compounds, and surfactants.

[0851] The outermost layer is formed by coating and drying using known methods.

[0852] The outermost coating amount (solid content) is preferably 0.01 g / m². 2 ~10g / m 2 More preferably 0.02 g / m 2 ~3g / m 2 0.1g / m 2 ~2.0g / m 2 .

[0853] The thickness of the outermost film is preferably 0.1 μm to 5.0 μm, more preferably 0.3 μm to 4.0 μm.

[0854] The thickness of the outermost 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.

[0855] The outermost layer may contain known additives such as plasticizers for imparting flexibility, surfactants for improving coatability, and inorganic particles for controlling surface slippage.

[0856] <Support Body>

[0857] The original lithographic printing plate involved in this invention has a support.

[0858] As a support, it can be appropriately selected from known supports for lithographic printing plates.

[0859] As a support, a support having a hydrophilic surface is preferred (hereinafter also referred to as "hydrophilic support").

[0860] As the support in this invention, an aluminum plate that has been roughened by a known method and then anodized is preferred. That is, the support in this invention preferably has an aluminum plate and an anodized aluminum film disposed on the aluminum plate.

[0861] Figure 1 This is a schematic cross-sectional view of one embodiment of the aluminum support 12a.

[0862] 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.

[0863] Furthermore, the support preferably has an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate, the anodic oxide film being located closer to the image recording layer side than the aluminum plate, the anodic oxide film having micropores extending from the surface of the image recording layer side along the depth direction, the average diameter of the micropores in the surface of the anodic oxide film being more than 10 nm and less than 100 nm.

[0864] Preferably, the 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 13 nm or less.

[0865] -Anodized film-

[0866] The preferred embodiment of the anodic oxide film 20a will be described below.

[0867] 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).

[0868] The average diameter (average opening diameter) of the micropores 22a on the surface of the anodic oxide film 20a 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 pore can be wider or narrower than the surface layer.

[0869] Excellent printing durability and image visual recognition are achieved when the average diameter exceeds 10 nm. Furthermore, excellent printing durability is also achieved when the average diameter is below 100 nm.

[0870] The average diameter of the micropores 22a is as follows: Using a field emission scanning electron microscope (FE-SEM) at 150,000x magnification, the surface of the anodic oxide film 20a was observed in N=4 images. In the four images obtained, 50 micropores were measured at 400×600 nm. 2 The value is obtained by averaging the diameter of the micropores within a certain range.

[0871] 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.

[0872] The shape of the micropore 22a is not particularly limited, in Figure 1 The core is generally straight tubular (generally cylindrical), but it can also be conical with a diameter that decreases 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.

[0873] In the support (1), the micropores can be composed of a large-diameter pore portion and a small-diameter pore portion. The large-diameter pore portion extends from the surface of the anodic oxide film to a certain depth, and the small-diameter pore portion is connected to the bottom of the large-diameter pore portion and extends from the connection position to a certain depth.

[0874] For example, such as Figure 2 As shown, the aluminum support 12b can be in the form of an aluminum plate 18 and an anodized film 20b having micropores 22b composed of large-diameter holes 24 and small-diameter holes 26.

[0875] For example, the micropores 22b in the anodic oxide film 20b are composed of large-diameter pores 24 and small-diameter pores 26, wherein 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 2The small-diameter hole 26 is connected to the bottom of the large-diameter hole 24 at the position of the hole, and extends further from the connection position to a depth of 20 nm to 2,000 nm. Specifically, for example, the method described in paragraphs 0107 to 0114 of Japanese Patent Application Publication No. 2019-162855 can be used.

[0876] -Manufacturing method of support body-

[0877] As a method for manufacturing the support used in this invention, for example, a manufacturing method that sequentially performs the following steps is preferred.

[0878] • Roughening process: The process of roughening the aluminum plate.

[0879] • Anodizing process: The process of anodizing roughened aluminum plates.

[0880] • 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.

[0881] The steps for each process are described in detail below.

[0882] <<Roughening Process>>

[0883] The roughening process is a process of performing a roughening treatment on the surface of an aluminum plate, including an electrochemical roughening treatment. 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. It can be performed using the method described in paragraphs 0086 to 0101 of Japanese Patent Application Publication No. 2019-162855.

[0884] <<Anodizing Process>>

[0885] 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.

[0886] 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.

[0887] 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 (preferably 1A / dm) 2 ~60A / dm 2The 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 size: 0.2g / m) 2 ~3g / m 2 ).

[0888] <<Hole Enlargement Treatment>>

[0889] 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).

[0890] 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.

[0891] The support may have a back coating on the side opposite to the image recording layer, as needed, containing an organic polymer compound as described in Japanese Patent Application Publication No. 5-45885 or a silicon alkoxy compound as described in Japanese Patent Application Publication No. 6-35174.

[0892] <Undercoat>

[0893] The lithographic printing plate master according to the present invention preferably has a base coating (sometimes also called 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 areas and facilitates the peeling of the image recording layer from the support in the unexposed areas. 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.

[0894] 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.

[0895] 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.

[0896] 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, methacryloyl groups, acrylamide groups, methacrylamide groups, and allyl groups are preferred.

[0897] 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 polar substituents and olefinic unsaturated bonds, and may be further copolymerized with monomers other than those described above, preferably hydrophilic monomers.

[0898] 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.

[0899] 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.

[0900] 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.

[0901] 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.

[0902] -Hydrophilic compounds-

[0903] From a developmental point of view, the base coating preferably contains a hydrophilic compound.

[0904] There are no particular restrictions on the use of hydrophilic compounds; any known hydrophilic compounds used in the base coat can be used.

[0905] 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.

[0906] Furthermore, as hydrophilic compounds, preferably are compounds having an amino group or a functional group with polymerization inhibition ability and a group that interacts with the surface of the support (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).

[0907] From the viewpoint of scratch stain inhibition, hydrophilic compounds preferably contain hydroxycarboxylic acids or their salts.

[0908] 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.

[0909] 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.

[0910] 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.

[0911] 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.

[0912] 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.

[0913] 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, or alcohols (refer to Iwanami Rika Dictionary, 5th edition, Iwanami Shoten, 1998).

[0914] The above-mentioned hydroxycarboxylic acid or its salt is preferably represented by the following formula (HC).

[0915] R HC (OH) mhc (COOM HC ) nhc Formula (HC)

[0916] 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.

[0917] 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.

[0918] Examples of hydrocarbon groups include those with an MHC+NHC valence derived from aliphatic hydrocarbons, such as alkylene, alkanetriyl, alkanetetrayl, alkanepentyl, alkenylene, alkenetriyl, alkenetetrayl, alkenepentyl, alkyneylene, alkynylenetriyl, alkynyltetrayl, and alkynylpentyl; and those with an MHC+NHC valence derived from aromatic hydrocarbons, such as arylene, aromatictriyl, aromatictetrayl, and aromaticpentyl. Examples of substituents other than hydroxyl and carboxyl groups include alkyl, alkenyl, alkynyl, aralkyl, and aryl groups. 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, and benzoyloxy. Methyl, benzyl, phenethyl, α-methylbenzyl, 1-methyl-1-phenethyl, 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 can have multiple of these divalent groups linked by any one of amide bonds, ether bonds, carbamate bonds, urea bonds, and ester bonds.

[0919] 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.

[0920] Furthermore, from the perspective of scratch stain inhibition, M HC Preferably, it is an alkali metal or onium, more preferably an alkali metal.

[0921] The total number of MHC and NHC is preferably 3 or more, more preferably 3 to 8, and even more preferably 4 to 6.

[0922] 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.

[0923] 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, monohydroxybenzoic acid derivatives (salicylic acid, lignoceric acid (high water content)). Salicylic acid, hydroxy(methyl)benzoic acid, vanillic acid, syringic acid, etc., dihydroxybenzoic acid derivatives (pyrocatechuic acid, dihydroxybenzoic acid, protocatechuic acid, gentianic acid, sphygmonic acid, etc.), trihydroxybenzoic acid derivatives (gallic acid, etc.), phenylacetic acid derivatives (mandelic acid, diphenylethanolic acid, arbutinic acid, etc.), hydrogenated cinnamic acid derivatives (o-hydroxyphenylpropionic acid, phloroglucinic acid, coumaric acid, umbelliferic acid, caffeic acid, ferulic acid, sinapic acid, cerebrolysinic acid, carmine acid, etc.), etc.

[0924] 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.

[0925] Furthermore, gluconic acid or shikimic acid is preferred as a compound having one carboxyl group and two or more hydroxyl groups.

[0926] Citric acid or malic acid is preferred as a compound having two or more carboxyl groups and one hydroxyl group.

[0927] Tartaric acid is preferred as a compound having two or more carboxyl groups and hydroxyl groups respectively.

[0928] Of these, gluconic acid is particularly preferred as the hydroxycarboxylic acid mentioned above.

[0929] Hydrophilic compounds can be used alone or in combination with two or more.

[0930] 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 particularly preferably 1.0% to 30% by mass, relative to the total mass of the base coating.

[0931] 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.

[0932] The primer layer can be applied using known methods.

[0933] The preferred coating weight (solid content) for the primer layer is 0.1 mg / m³. 2 ~300mg / m 2 More preferably 5 mg / m 2 ~200mg / m 2 .

[0934] The original lithographic printing plate involved in this invention may have other layers besides those described above.

[0935] There are no particular restrictions on the other layers; any known layer can be used. For example, if necessary, a back coating layer can be provided on the side of the support opposite to the image recording layer side.

[0936] (Methods for making offset printing plates and offset printing methods)

[0937] The method for manufacturing the lithographic printing plate of the present invention preferably includes: a step of exposing the original lithographic printing plate of the present invention in an image-like manner (exposure step); and a step of supplying at least one of the group consisting of printing ink and dampening solution to the exposed original lithographic printing plate on a printing press to remove the non-image portion of the image recording layer (on-machine development step).

[0938] 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-like manner (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 a printing press to remove the image recording layer of non-image areas (on-machine development step); and a step of printing using the obtained offset printing plate (hereinafter also referred to as "printing step").

[0939] <Exposure Process>

[0940] 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.

[0941] 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 2Furthermore, 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.

[0942] 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.

[0943] <On-machine developing process>

[0944] The method for manufacturing a lithographic printing plate according to the present invention preferably includes an on-machine developing 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.

[0945] The following is an explanation of the on-machine development method.

[0946] [In-machine development method]

[0947] 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.

[0948] 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 section. 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 multiple print runs. As for oil-based inks and water-based components, conventional offset printing inks and dampening solutions are preferred.

[0949] The laser used for image exposure of the lithographic printing plate original involved in this invention preferably has a wavelength of 750 nm to 1,400 nm. The aforementioned light source is preferred.

[0950] <Printing Process>

[0951] 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.

[0952] There are no particular restrictions on the type of printing ink, and various known inks can be used as needed. Furthermore, oil-based inks or ultraviolet-curing inks (UV inks) are preferred as printing inks.

[0953] Furthermore, dampening solution can be supplied as needed during the aforementioned printing process.

[0954] 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.

[0955] As a recording medium, there are no particular restrictions, and any known recording medium can be used as needed.

[0956] In the method for manufacturing a lithographic printing plate derived 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 very strong conditions, 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.

[0957] Example

[0958] The present invention will now be described in detail through examples, but the invention is not limited thereto. In these examples, unless otherwise specified, "%" and "parts" refer to "mass %" and "parts by mass," respectively. Furthermore, in polymer compounds, except for specifically defined polymer compounds, the molecular weight is the weight-average molecular weight (Mw), and the ratio of repeating structural units is the molar percentage. The weight-average molecular weight (Mw) is a value determined as a polystyrene conversion value based on gel permeation chromatography (GPC).

[0959] (Examples 1 to 18, and Comparative Examples 1 and 2)

[0960] <Fabrication of Supports A and B>

[0961] <<Processing A and B>>

[0962] (Aa) Alkali etching treatment

[0963] Etching was performed on an aluminum plate by spraying an aqueous solution of caustic soda (26% by mass) and aluminum ions (6.5% by mass) using a sprayer at 70°C. A spray-based water wash was then performed. The aluminum dissolution rate on the surface after electrochemical roughening was 5 g / m². 2 .

[0964] (Ab) Acidic aqueous solution was used for decontamination treatment (Decontamination Treatment 1).

[0965] Next, a decontamination treatment was performed using an acidic aqueous solution. The acidic aqueous solution used was a 150 g / L sulfuric acid solution at a temperature of 30°C. The acidic aqueous solution was sprayed onto the aluminum plate using a sprayer and the decontamination was performed for 3 seconds. Then, a water rinsing process was carried out.

[0966] (Ac) Electrochemical roughening treatment

[0967] Next, an electrochemical roughening treatment was performed using an electrolyte solution with a hydrochloric acid concentration of 14 g / L, an aluminum ion concentration of 13 g / L, and a sulfuric acid concentration of 3 g / L, using alternating current. The electrolyte temperature was 30°C. The aluminum ion concentration was adjusted by adding aluminum chloride.

[0968] The alternating current waveform is a symmetrical sine wave with positive and negative phases, and a frequency of 50 Hz. The ratio of the anode reaction time to the cathode reaction time in one cycle of the alternating current is 1:1. The current density, expressed as the peak current of the alternating current waveform, is 75 A / dm³. 2 Furthermore, the electrical charge, calculated as the total charge generated by the aluminum plate participating in the anode reaction, is 450 C / dm. 2 Regarding electrolytic treatment, with a 4-second energizing interval, at 112.5C / dm³ 2 The process was performed in four steps. A carbon electrode was used as the counter electrode in the aluminum plate. Then, a water washing process was carried out.

[0969] (Ad) Alkali etching treatment

[0970] At 45°C, an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) was sprayed onto an electrochemically roughened aluminum plate using a sprayer, followed by etching. The dissolved aluminum content on the electrochemically roughened surface was 0.2 g / m². 2 Then, it underwent a water washing process.

[0971] (Ae) used an acidic aqueous solution for decontamination treatment.

[0972] Next, an acidic aqueous solution was used for decontamination. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate using a sprayer and the decontamination was carried out for 3 seconds. The acidic aqueous solution used for decontamination was an aqueous solution with a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L. The solution temperature was 30°C.

[0973] (Af) Stage 1 Anodizing Treatment

[0974] Using based Figure 6 The DC electrolytic anodizing apparatus with the structure shown underwent the first stage of anodizing treatment. Anodizing was performed under the conditions specified in the "First Anodizing Treatment" column of Table 1, resulting in an anodized film of a predetermined amount.

[0975] (Ag) Hole Enlargement Treatment

[0976] Under the time conditions shown in Table 1, the aluminum plates that had undergone the above anodizing treatment were immersed in an aqueous solution of caustic soda at a temperature of 40°C, a sodium hydroxide concentration of 5% by mass, and an aluminum ion concentration of 0.5% by mass, and then subjected to a pore-expanding treatment. Afterwards, a spray-based water washing process was performed.

[0977] (Ah) Stage 2 Anodizing Treatment

[0978] Using based Figure 6 The DC electrolytic anodizing apparatus with the structure shown underwent a second-stage anodizing process. Anodizing was performed under the conditions listed in the "Second Anodizing Process" column of Table 1, resulting in an anodized film of a specified amount. However, as shown in Table 1, the second-stage anodizing process was not performed in surface treatment B.

[0979] [Table 1]

[0980]

[0981]

[0982] <Fabrication of Supports C to E>

[0983] <<Surface Treatment C>>

[0984] (Ca) Mechanical roughening treatment (brushing method)

[0985] Use such as Figure 5 The apparatus shown contains a suspension of pumice powder (specific gravity 1.1 g / cm³). 3 While being supplied to the surface of the aluminum plate as an abrasive slurry, it undergoes mechanical roughening treatment via a rotating stiff-bristled brush. Figure 5In the diagram, 1 is an aluminum plate, 2 and 4 are roller brushes (in this embodiment, they are stiff bristle brushes), 3 is grinding slurry, and 5, 6, 7 and 8 are support rollers.

[0986] In the mechanical roughening process, the median particle size (μm) of the abrasive material was set to 30μm, the number of brushes was set to 4, and the brush rotation speed (rpm) was set to 250rpm. The stiff bristle tuft brush was made of 6 / 10 nylon, with bristle diameter of 0.3mm and bristle length of 50mm. The brush was constructed by drilling holes and densely packing bristles into a φ300mm stainless steel sleeve. The distance between the two support rollers (φ200mm) at the bottom of the stiff bristle tuft brush was 300mm. The load on the drive motor that pressed the stiff bristle tuft brush until it rotated was increased by 10kW compared to the load before pressing the brush against the aluminum plate. The rotation direction of the brush was the same as the movement direction of the aluminum plate.

[0987] (Cb) alkaline etching treatment

[0988] The aluminum plate obtained above was etched by spraying an aqueous solution of caustic soda (26% by mass) and aluminum ion concentration (6.5% by mass) through a nozzle at a temperature of 70°C. Then, a water wash was performed using the sprayer. The aluminum dissolution rate was 10 g / m³. 2 .

[0989] (Cc) Decontamination treatment in acidic aqueous solution

[0990] Next, a decontamination treatment was performed in an aqueous nitric acid solution. The nitric acid solution used for the decontamination treatment was waste liquid of nitric acid used for electrochemical roughening in the next process. The liquid temperature was 35°C. The decontamination treatment was performed for 3 seconds by spraying the decontamination solution with a sprayer.

[0991] (Cd) Electrochemical roughening treatment

[0992] Electrochemical roughening treatment was performed continuously using nitric acid electrolysis at an AC voltage of 60 Hz. The electrolyte used was an aqueous solution of 10.4 g / L nitric acid at 35°C, with aluminum nitrate added to adjust the aluminum ion concentration to 4.5 g / L. The AC power supply waveform was as follows. Figure 3 The waveform shown, with a current value reaching its peak value from zero in 0.8 msec (tp), a duty ratio of 1:1, and a trapezoidal rectangular wave AC current, was used. The carbon electrode was electrochemically roughened as the counter electrode. Ferrite was used as the auxiliary anode. Regarding the electrolytic cell, [the following is a description of the process:] A trapezoidal rectangular wave AC current was used. Figure 4 The electrolytic cell shown. The current density, expressed as peak current, is 30 A / dm³. 2 This causes 5% of the current flowing from the power source to be diverted to the auxiliary anode. (Electricity (C / dm³)) 2 The total charge when using an aluminum plate as the anode is 185 C / dm. 2Then, a spray-based water wash was performed.

[0993] (Ce) alkaline etching treatment

[0994] The aluminum plate obtained above was etched by spraying an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) through a nozzle at 50°C. Then, a water wash was performed using the sprayer. The aluminum dissolution rate was 0.5 g / m³. 2 .

[0995] (Cf) Decontamination treatment in acidic aqueous solution

[0996] Next, a decontamination treatment was performed in a sulfuric acid aqueous solution. The sulfuric acid aqueous solution used for the decontamination treatment had a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L. The solution temperature was 30°C. The decontamination treatment was performed for 3 seconds by spraying the decontamination solution using a sprayer.

[0997] (Cg) Electrochemical roughening treatment

[0998] Electrochemical roughening treatment was performed continuously using hydrochloric acid electrolysis at an AC voltage of 60 Hz. The electrolyte was an aqueous solution of 6.2 g / L hydrochloric acid at 35°C, with aluminum chloride added to adjust the aluminum ion concentration to 4.5 g / L. The AC power supply waveform was as follows: Figure 3 The waveform shown, with a current value reaching its peak value from zero in 0.8 msec (tp), a duty ratio of 1:1, and a trapezoidal rectangular wave AC current, was used. The carbon electrode was electrochemically roughened as the counter electrode. Ferrite was used as the auxiliary anode. Regarding the electrolytic cell, [the following is a description of the process:] A trapezoidal rectangular wave AC current was used. Figure 4 The electrolytic cell shown.

[0999] The current density, measured in peak current, is 25 A / dm. 2 The amount of electricity generated during hydrochloric acid electrolysis (C / dm³) 2 The total charge when using an aluminum plate as the anode is 63 C / dm. 2 Then, a spray-based water wash was performed.

[1000] (Ch) Alkali etching treatment

[1001] The aluminum plate obtained above was etched by spraying an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) through a nozzle at 50°C. Then, a water wash was performed using the sprayer. The aluminum dissolution rate was 0.1 g / m³. 2 .

[1002] (Ci) Decontamination treatment in acidic aqueous solution

[1003] Next, a decontamination treatment was performed in an aqueous sulfuric acid solution. Specifically, the waste liquid generated during the anodizing process (containing 5 g / L of dissolved aluminum ions in a 170 g / L aqueous sulfuric acid solution) was used for a 4-second decontamination treatment at a liquid temperature of 35°C. A 3-second decontamination treatment was then performed by spraying the decontamination solution using a sprayer.

[1004] (Cj) Stage 1 Anodizing Treatment

[1005] Using based Figure 6 The DC electrolytic anodizing apparatus shown performed the first stage of anodizing treatment. Anodizing was performed under the conditions shown in Table 1, and an anodized film of a specified thickness was formed. Furthermore, in the anodizing apparatus 610, the aluminum plate 616, as... Figure 6 The aluminum plate 616 is conveyed as indicated by the middle arrow. In the power supply tank 612 containing electrolyte 618, the aluminum plate 616 is charged (+) by the power supply electrode 620. Furthermore, the aluminum plate 616 is conveyed upwards in the power supply tank 612 by roller 622, then downwards by clamping roller 624, and finally conveyed to the electrolytic treatment tank 614 containing electrolyte 626, and then horizontally by roller 628. Next, the aluminum plate 616 is charged (-) by electrolytic electrode 630, thereby forming an anodized film on its surface. The aluminum plate 616 leaving the electrolytic treatment tank 614 is conveyed to subsequent processes. In the anodizing treatment apparatus 610, roller 622, clamping roller 624, and roller 628 constitute a direction-changing mechanism. In the inter-tank section between the power supply tank 612 and the electrolytic treatment tank 614, the aluminum plate 616 is conveyed in a mountain-shaped and inverted U-shaped manner by the aforementioned rollers 622, 624, and 628. The power supply electrode 620 and the electrolysis electrode 630 are connected to the DC power supply 634.

[1006] (Ck) Hole Enlargement Treatment

[1007] Under the conditions shown in Table 1, the aluminum plate that had undergone the above anodizing treatment was immersed in an aqueous solution of caustic soda at a temperature of 35°C, a sodium hydroxide concentration of 5% by mass, and an aluminum ion concentration of 0.5% by mass, and then subjected to a pore-expanding treatment. Then, a spray-based water washing was performed.

[1008] (Cl) Stage 2 Anodizing Treatment

[1009] Using based Figure 6 The DC electrolytic anodizing apparatus with the structure shown underwent the second stage of anodizing. Anodizing was performed under the conditions shown in Table 2, thereby forming an anodized film of a specified thickness.

[1010] (Cm) Stage 3 Anodizing Treatment

[1011] Using based Figure 6 The DC electrolytic anodizing apparatus with the structure shown underwent the third stage of anodizing. Anodizing was performed under the conditions shown in Table 2, thereby forming an anodized film of a specified thickness.

[1012] <<Surface Treatment D>>:

[1013] [A support body with both large-diameter and small-diameter bores]

[1014] (Da) Alkali etching treatment

[1015] Etching was performed on an aluminum plate at 70°C by spraying an aqueous solution of caustic soda (sodium hydroxide) with a concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass through a spray nozzle. A water wash was then performed based on the sprayer. The aluminum dissolution rate on the surface after electrochemical roughening was 1.0 g / m². 2 .

[1016] (Db) Decontamination treatment in acidic aqueous solution (first decontamination treatment)

[1017] Next, a decontamination treatment was performed in an acidic aqueous solution. A sulfuric acid solution of 150 g / L was used for the decontamination treatment at a temperature of 30°C. The decontamination was carried out for 3 seconds by spraying the solution with a sprayer. Then, a water rinsing treatment was performed.

[1018] (Dc) Electrochemical roughening treatment in hydrochloric acid aqueous solution

[1019] Next, an electrolyte solution with a hydrochloric acid concentration of 14 g / L, an aluminum ion concentration of 13 g / L, and a sulfuric acid concentration of 3 g / L was used for electrolytic roughening treatment using alternating current. The electrolyte temperature was 30°C. The aluminum ion concentration was adjusted by adding aluminum chloride. The alternating current waveform was a symmetrical sine wave with positive and negative waveforms and a frequency of 50 Hz. The ratio of the anodic reaction time to the cathode reaction time in one cycle of the alternating current was 1:1, and the current density, measured by the peak current of the alternating current waveform, was 75 A / dm³. 2 Furthermore, the electrical charge, calculated as the total charge generated by the aluminum plate participating in the anode reaction, is 450 C / dm. 2 Regarding electrolytic treatment, with a 4-second energizing interval, at 125C / dm 2 The process was performed in four steps. A carbon electrode was used as the counter electrode in the aluminum plate. Then, a water washing process was carried out.

[1020] (Dd) alkaline etching treatment

[1021] At 45°C, an aqueous solution of caustic soda (5% by mass) and aluminum ion concentration (0.5% by mass) was sprayed onto an electrochemically roughened aluminum plate using a nozzle, followed by etching. The dissolved aluminum content on the electrochemically roughened surface was 0.2 g / m². 2 Then, it underwent a water washing process.

[1022] (De) Decontamination treatment in acidic aqueous solutions

[1023] Next, a decontamination treatment was performed in an acidic aqueous solution. The acidic aqueous solution used for this treatment was waste liquid generated during the anodizing process (containing 5.0 g / L aluminum ions dissolved in a 170 g / L sulfuric acid aqueous solution). The solution temperature was 30°C. The decontamination treatment was performed for 3 seconds by spraying the solution with a sprayer.

[1024] (Df) Stage 1 Anodizing Treatment

[1025] Using based Figure 6 The DC electrolytic anodizing apparatus with the structure shown underwent the first stage of anodizing. Anodizing was performed under the conditions shown in Table 2, thereby forming an anodized film of a specified thickness.

[1026] (Dg) Hole Enlargement Treatment

[1027] Under the conditions shown in Table 1, the aluminum plate that had undergone the above anodizing treatment was immersed in an aqueous solution of caustic soda at a temperature of 35°C, a sodium hydroxide concentration of 5% by mass, and an aluminum ion concentration of 0.5% by mass, and then subjected to a pore-expanding treatment. Then, a spray-based water washing was performed.

[1028] (Dh) Stage 2 Anodizing Treatment

[1029] Using based Figure 6 The DC electrolytic anodizing apparatus with the structure shown underwent the second stage of anodizing. Anodizing was performed under the conditions shown in Table 2, thereby forming an anodized film of a specified thickness.

[1030] The supports C to E described in Tables 2 and 3 were obtained by the above surface treatments C or D.

[1031] The average diameter (nm) of the large-diameter pores on the surface of the anodic oxide film after the second anodizing process, the average diameter (nm) of the small-diameter pores at the connecting positions, the depth (nm) of the large-diameter and small-diameter pores, and the indentation density (micropore density, unit: pores / μm) are calculated. 2The thickness (nm) of the anodized film from the bottom of the small-diameter hole to the surface of the aluminum plate is summarized in Table 2.

[1032] Furthermore, the average diameter of the micropores (average diameter of the large-diameter and small-diameter pore portions) is as follows: N=4 images of the large-diameter and small-diameter pore surfaces were observed using FE-SEM at 150,000x magnification. The diameters of the micropores (large-diameter and small-diameter pore portions) existing in the 400nm×600nm range were measured in the four images, and the average value was obtained. Additionally, in cases where the large-diameter pores are deep and it is difficult to measure the diameter of the small-diameter pores, and in cases where the enlarged diameter pores within the small-diameter pores are measured, the upper part of the anodic oxide film is cut, and then various diameters are determined.

[1033] The depth of the micropores (the depth of the large-diameter pores and the small-diameter pores) is as follows: the cross-section of the support (anodic oxide film) is observed using FE-SEM (large-diameter pore depth observation: 150,000x, small-diameter pore depth observation: 50,000x), and the depth of any 25 micropores in the obtained image is measured and averaged.

[1034] In addition, in Table 2, the film amount (AD) in the first and second anodizing treatment columns indicates the film amount obtained in each treatment. Furthermore, the electrolyte used is an aqueous solution containing the components listed in Table 2.

[1035] In Table 2, "170 / 5" in the component concentration column refers to a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L. Furthermore, in Table 2, the temperature unit is "°C" and the current density unit is "A / dm³". 2 The unit for time is "s", and the unit for membrane volume is "g / m". 2 ".

[1036] [Table 2]

[1037]

[1038] [Table 3]

[1039]

[1040] <Methods for forming base coatings A to C>

[1041] On the support as described in Table 4, the dry coating amount is 20 mg / m². 2 The primer coating is formed by applying any one of the primer coating liquids A to C with the following compositions as described in Table 4 and drying it in an oven at 100°C for 30 seconds.

[1042] -Composition of Primer Coating Solution A-

[1043] • Polymer (U-1) [with the following structure]: 0.18 parts

[1044] Hydroxyethyliminodiacetic acid: 0.10 parts

[1045] Water: 61.4 parts

[1046] [Chemical Formula 68]

[1047]

[1048] -Composition of Primer Coating Solution B-

[1049] • Polymer (U-1): 0.14 parts

[1050] Sodium gluconate: 0.07 parts

[1051] Surfactant (EMALEX 710, manufactured by NIHON EMULSION Co., Ltd.): 0.0016 parts by weight

[1052] • Preservative (manufactured by Biohope L, K·I Chemical Industry Co., LTD.): 0.0015 parts

[1053] Water: 3.29 parts

[1054] -Composition of the primer coating liquid C-

[1055] • Polymer (U-1): 0.14 parts

[1056] Chelest400: 0.035 portions

[1057] Chelest3EAF: 0.035 copies

[1058] Surfactant (EMALEX 710, manufactured by NIHON EMULSION Co., Ltd.): 0.0016 parts by weight

[1059] • Preservative (manufactured by Biohope L, K·I Chemical Industry Co., LTD.): 0.0015 parts

[1060] Water: 3.29 parts

[1061] Synthesis of Polymer (U-1)-

[1062] <<Purification of Monomer M-1>>

[1063] 420 parts of LIGHT ESTER P-1M (2-methacryloyloxyethyl phosphate, manufactured by Kyoisha Chemical Co., Ltd.), 1,050 parts of diethylene glycol dibutyl ether, and 1,050 parts of distilled water were added to a separatory funnel, stirred vigorously, and then allowed to stand. After discarding the upper layer, 1,050 parts of diethylene glycol dibutyl ether were added, stirred vigorously, and then allowed to stand. After discarding the upper layer, 1,300 parts of an aqueous solution of monomer M-1 (10.5% by mass of solids) were obtained.

[1064] <<Synthesis of Polymer (U-1)>>

[1065] 53.73 parts of distilled water and 3.66 parts of monomer M-2 (shown below) were added to a three-necked flask, and the mixture was heated to 55°C under nitrogen. Then, dropwise addition of solution 1 (shown below) was added over 2 hours, followed by stirring for 30 minutes. Next, 0.386 parts of VA-046B (manufactured by FUJIFILMWako Pure Chemical Corporat ion) were added, and the mixture was heated to 80°C and stirred for 1.5 hours. After the reaction mixture was allowed to return to room temperature (25°C), a 30% (w / w) sodium hydroxide aqueous solution was added to adjust the pH to 8.0, and then 0.005 parts of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxy(4-OH-TEMPO) were added. Through these operations, 180 parts of an aqueous solution of polymer (U-1) were obtained. The weight-average molecular weight (Mw) of polyethylene glycol, as determined by gel permeation chromatography (GPC), was 200,000.

[1066] [Chemical Formula 69]

[1067]

[1068] Composition of Additive 1

[1069] • 87.59 parts of the above monomer M-1 aqueous solution

[1070] • 14.63 parts of the above monomer M-2

[1071] ·VA-046B (2,2'-azobis[2-(2-imidazolin-2-yl)propane] disulfate dihydrate, manufactured by FUJIFILMWako Pure Chemical Corporation): 0.386 parts

[1072] • Distilled water: 20.95 parts

[1073] <Formation of Image Recording Layer>

[1074] The image recording layer coating solution with the composition described in Tables 4 to 6 (wherein the image recording layer coating solution contains each component described in Tables 4 to 6, and is prepared to a solid content of 6% by mass using a mixed solvent of 1-methoxy-2-propanol (MFG): methyl ethyl ketone (MEK): methanol = 4:4:1 (mass ratio)) was rod-coated onto a support or primer and dried at 120°C for 40 seconds, thereby forming a dry coating weight of 1.0 g / m 2 Image recording layer.

[1075] The following shows the components used in the image recording layer.

[1076] [Infrared absorber]

[1077] IR-1~IR-10: Compounds with the following structures

[1078] [Chemical Formula 70]

[1079]

[1080] [Chemical Formula 71]

[1081]

[1082] Additionally, Bu represents n-butyl, Ph represents phenyl, and TsO - This indicates the p-toluenesulfonate anion.

[1083] Electron-receiving polymerization initiators

[1084] Int-1~Int-7: Compounds with the following structures, where Ts0 represents the p-toluenesulfonate anion and Ph represents the phenyl group.

[1085] [Chemical Formula 72]

[1086]

[1087] [Electron-donating polymerization initiators]

[1088] B-1~B-4: Compounds with the following structures

[1089] [Chemical Formula 73]

[1090]

[1091] [Polymerizing compounds]

[1092] M-1: The following compounds

[1093] M-2: The following compounds

[1094] M-3: Dipentaerythritol pentaacrylate, SR-399 manufactured by Sartomer Company, Inc

[1095] M-4: Urethane acrylate, U-15HA manufactured by Shin-Nakamura Chemical Co., Ltd

[1096] M-5: Monomer synthesized by the following synthesis method

[1097] [Chemical formula 74]

[1098]

[1099] <Synthesis of M-5>

[1100] A mixed solution of Takenate D-160N (polyisocyanate-trimethylolpropane adduct, manufactured by Mitsui Chemicals, Inc., 4.7 parts), ARONIX M-403 (manufactured by TOAGOSEI CO., LTD., an amount such that the NCO value of Takenate D-160N and the hydroxyl value of ARONIX M-403 are 1:1), tert-butylbenzoquinone (0.02 parts), and methyl ethyl ketone (11.5 parts) was heated to 65°C. Neostann U-600 (bismuth-based polycondensation catalyst, manufactured by NITTO KASEI CO., LTD., 0.11 parts) was added to the reaction solution, and it was heated at 65°C for 4 hours. The reaction solution was cooled to room temperature (25°C), and methyl ethyl ketone was added, thereby synthesizing a urethane acrylate solution with a solid content of 50% by mass. Using a recycled GPC (equipment: LC908-C60, column: JAIGEL-1H-40 and 2H-40 (manufactured by Japan Analytical Industry)), the molecular weight fraction of the urethane acrylate (M-5) solution was carried out with a eluent of tetrahydrofuran (THF). The weight average molecular weight was 20,000

[1101] [Binder polymer]

[1102] P-1: Polyvinyl acetal, S-LEC BX-5Z manufactured by SEKISUI CHEMICAL CO., LTD

[1103] P-2: Polyvinyl acetal, S-LEC BL10 manufactured by SEKISUI CHEMICAL CO., LTD

[1104] P-3: Resin synthesized by the following synthesis method

[1105] Synthesis of Adhesive Polymer P-3

[1106] 78.0 parts of 1-methoxy-2-propanol were weighed into a three-necked flask and heated to 70°C under a nitrogen atmosphere. After 2 hours and 30 minutes, a mixed solution consisting of 52.1 parts of BLEMMER PME-100 (methoxydiethylene glycol monomethacrylate, manufactured by NOFCORPORATION), 21.8 parts of methyl methacrylate, 14.2 parts of methacrylic acid, 2.15 parts of dipentaerythritol hexa(3-mercaptopropionic acid), 0.38 parts of V-601 (dimethyl 2,2'-azobis(isobutyrate), manufactured by FUJIFILM Wako PureChemical Corporation), and 54 parts of 1-methoxy-2-propanol was added dropwise to the reaction vessel. After the addition was complete, the temperature was raised to 80°C, and the reaction was continued for 2 hours. A mixed solution containing 0.04 parts V-601 and 4 parts 1-methoxy-2-propanol was added, and the mixture was heated to 90°C and reacted for 2.5 hours. After the reaction was complete, the reaction solution was cooled to room temperature.

[1107] The above reaction solution was mixed with 137.2 parts of 1-methoxy-2-propanol, 0.24 parts of 4-hydroxytetramethylpiperidine-N-oxide, 26.0 parts of glycidyl methacrylate, and 3.0 parts of tetraethylammonium bromide, and then heated at 90°C.

[1108] After 18 hours, the reaction solution was cooled to room temperature (25°C) and then diluted with 99.4 parts of 1-methoxy-2-propanol.

[1109] The resulting adhesive polymer P-3 has a solids concentration of 23% by mass and a polystyrene equivalent weight-average molecular weight of 35,000 as determined by GPC.

[1110] [Chemical Formula 75]

[1111]

[1112] [Acid colorimetric reagent]

[1113] S-1~S-4: The following compounds

[1114] [Chemical Formula 76]

[1115]

[1116] [Hydrophilic compounds]

[1117] T-1: Tris(2-hydroxyethyl) isocyanurate

[1118] T-2: Compounds with the following structures

[1119] T-3: Hydroxypropyl cellulose, Klucel M, manufactured by Hercules.

[1120] [Chemical Formula 77]

[1121]

[1122] [surfactants]

[1123] Surfactant: Anionic surfactant, RAPISOL A-80, manufactured by NOF CORPORATION

[1124] [Polymer particles]

[1125] <Preparation of Polymer Particles R-1>

[1126] • Microgel (polymer particles R'-1): 2.640 parts

[1127] • Distilled water: 2.425 parts

[1128] The preparation method of the above-mentioned microgels is shown below.

[1129] Preparation of polyisocyanate compounds-

[1130] 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 added and stirred. Bismuth tris(2-ethylhexanoate) (NEOSTANN U-600, manufactured by NITTO KASEI CO., LTD.) was added and stirred until heating was inhibited. The reaction temperature was set at 50°C and stirred for 3 hours to obtain an ethyl acetate solution (50% by mass) of polyisocyanate compound (1).

[1131] [Chemical Formula 78]

[1132]

[1133] -Preparation of microgels-

[1134] The oil and aqueous phases were mixed and emulsified using a homogenizer at 12,000 rpm for 10 minutes. The resulting emulsion was stirred at 45°C for 4 hours, and then 5.20 g of a 10% (w / w) aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-ene-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% (w / w) with distilled water to obtain an aqueous dispersion of the microgel. The average particle size, determined by light scattering, was 0.20 μm.

[1135] ~Oil phase ingredients~

[1136] (Component 1) Ethyl acetate: 12.0 parts

[1137] (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 mono-terminated methylated polyoxyethylene (1 molar equivalent, number of repeats of oxyethylidene units: 90).

[1138] (Component 3) Polyisocyanate compound (1) (as a 50% by mass ethyl acetate solution): 15.0 parts

[1139] (Component 4) 11.54 parts of 65% by weight ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer Company, Inc.)

[1140] (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.)

[1141] ~Aqueous phase components~

[1142] Distilled water: 46.87 parts

[1143] <Production of Polymer Particles R-2>

[1144] -Preparation of oil phase components-

[1145] The oil phase composition was obtained by stirring a mixture of polyfunctional isocyanate compounds (PM-200: manufactured by Wanhua Chemical Co., Ltd.) for 6.66 g; a 50% by mass ethyl acetate solution of “Takenate (registered trademark) D-116N (an adduct of trimethylolpropane (TMP), m-phenylenedimethyl diisocyanate (XDI) and polyethylene glycol monomethyl ether (EO90) (structure below)” manufactured by Mitsui Chemicals, Inc. for 5.46 g; a 65% by mass ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer Company, Inc.) for 11.24 g; ethyl acetate for 14.47 g; and PIONIN (registered trademark) A-41-C manufactured by Takemoto Oil & Fat Co., Ltd. for 0.45 g.

[1146] [Chemical Formula 79]

[1147]

[1148] -Preparation of Aqueous Phase Components-

[1149] 47.2g of distilled water was prepared as the aqueous phase component.

[1150] -Microencapsulation process-

[1151] An emulsion was obtained by adding an aqueous component to the oil phase and mixing the mixture, then emulsifying the resulting mixture at 12,000 rpm for 16 minutes using a homogenizer.

[1152] 16.8 g of distilled water was added to the obtained emulsion, and the resulting liquid was stirred at room temperature for 10 minutes.

[1153] Next, the stirred liquid was heated to 45°C and stirred for 4 hours while maintaining the temperature at 45°C, thereby removing ethyl acetate from the liquid by distillation. Then, 5.12 g of a 10% by mass aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-ene-octanoate (U-CAT SA102, manufactured by San-Apro Ltd.) was added, stirred at room temperature for 30 minutes, and allowed to stand at 45°C for 24 hours. The concentration of the solids was adjusted to 20% by mass with distilled water to obtain an aqueous dispersion of polymer particles R-2. The volume average particle size of R-2 was measured using a laser diffraction / scattering particle size distribution measuring device LA-920 (manufactured by HORIBA, Ltd.) and was found to be 165 nm.

[1154] <Preparation of Polymer Particles R-3>

[1155] A dispersion unit consisting of the following compound B-1 (n=45): 10.0 parts, 85.0 parts of distilled water, and 240.0 parts of n-propanol was added to a four-necked flask and heated and stirred at 70°C under nitrogen.

[1156] Next, after 2 hours, a mixture of 20.0 parts of the following compound A-1, 70.0 parts of the following compound A-2, and 0.7 parts of 2,2'-azobisisobutyronitrile was added dropwise to a four-necked flask.

[1157] After the addition was complete, the reaction was allowed to continue for 5 hours without any change. Then, 0.5 parts of 2,2'-azobisisobutyronitrile were added, and the temperature was raised to 80°C. 0.4 parts of 2,2'-azobisisobutyronitrile were added every 6 hours, and the reaction was carried out for a total of 19 hours.

[1158] The reaction solution was naturally cooled to room temperature (25°C) to obtain a dispersion of polymer particles R-3 (solid content 23%).

[1159] [Chemical Formula 80]

[1160]

[1161] The median particle size of polymer particles R-3 is 150 nm, and the coefficient of variation is 23%.

[1162] Furthermore, regarding the dispersibility of polymer particles R-3, the results confirmed by the described methods indicate that resin particles R-3 are water-dispersible particles and organic solvent-dispersible particles.

[1163] <Preparation of Polymer Particles R-4>

[1164] In a three-necked flask, 350 parts of distilled water, 150 parts of compound A-1, 220 parts of compound A-2, 320 parts of compound A-3, and 10 parts of compound B-1 (n=45) were added, and the mixture was heated to 70°C under nitrogen. Then, 1.0 part of potassium persulfate (KPS) was added, and the mixture was heated and stirred for 3 hours, followed by a reaction at 95°C for 4 hours. The reaction solution was allowed to cool naturally to room temperature (25°C) to obtain an aqueous dispersion of polymer particles R-4 (solid content 22%). The average particle size of polymer particles R-4 was 142 nm.

[1165] [Chemical Formula 81]

[1166]

[1167] <Preparation of Polymer Particles R-5>

[1168] 288 parts of ion-exchanged water, 1.6 parts of sodium dodecylbenzenesulfonate, 0.5 parts of A-1 and 0.2 parts of A-2 were added to a three-necked flask, and the mixture was stirred and emulsified at 200 rpm for 15 minutes at 75°C under nitrogen.

[1169] 0.15 parts potassium persulfate (KPS) and 7 parts ion-exchanged water were added, and the mixture was heated and stirred at 80°C for 30 minutes.

[1170] After adding 24.7 parts of A-1, 12.8 parts of A-2, and 6.7 parts of A-4 dropwise over 3 hours, the mixture was continuously heated and stirred for 1 hour. The reaction solution was then allowed to cool naturally to room temperature (25°C) to obtain an aqueous dispersion of polymer particles R-5 (solid content 13%). The average particle size of polymer particles R-5 was 40 nm.

[1171] [Chemical Formula 82]

[1172]

[1173] [Chemical Formula 83]

[1174]

[1175] <Formation of the outermost layer>

[1176] The outermost coating solution with the composition listed in Table 4 (which comprises all the components listed in Table 4 and is prepared by ion-exchange water to a solid content of 6% by mass) was applied to the image recording layer and dried at 120°C for 60 seconds, thereby forming a dry coating with a coating weight of 0.15 g / m². 2 The outermost layer.

[1177] In addition, the preparation method of the inorganic layered compound dispersion (1) used in the outermost coating liquid is described below.

[1178] <<Preparation of Inorganic Layered Compound Dispersion (1)>>

[1179] 6.4 parts of synthetic mica (SOMASIFME-100, manufactured by Co-op Chemical Co., Ltd.) were added to 193.6 parts of ion-exchanged water and dispersed using a homogenizer until the volume average particle size (laser scattering method) was 3 μm. The aspect ratio of the obtained dispersed particles was greater than 100.

[1180] [Color-changing compounds]

[1181] wIR-1~wIR-6: The following compounds

[1182] [Chemical Formula 84]

[1183]

[1184] [Hydrophilic polymers]

[1185] WP-1: Polyvinyl alcohol, Mowiol 4-88 manufactured by Sigma-Aldrich Co. LLC.

[1186] WP-2: Polyvinyl alcohol, Mowiol 8-88 manufactured by Sigma-Aldrich Co. LLC.

[1187] WP-3: The following resin (Mw52,000)

[1188] WP-4: Cellulose, METOLOSE 60SH-15 manufactured by Shin-Etsu Chemical Co., Ltd.

[1189] WP-5: Polyvinyl alcohol, Gohsenol L-3266 manufactured by Mitsubishi Chemical Corporation, with a saponification degree of 86-89% or higher.

[1190] WP-6: Cellulose, METOLOSE SM04 manufactured by Shin-Etsu Chemical Co., Ltd.

[1191] [Chemical Formula 85]

[1192]

[1193] [Hydrophobic polymers]

[1194] L-1: Aqueous dispersion of polyvinylidene chloride, manufactured by Solvin Company, Diofan (registered trademark) A50

[1195] L-2: Styrene-acrylic resin, FS-201 manufactured by Nipponpaint Industrial Coatings Co., LTD.

[1196] L-3: Styrene-acrylic resin, FS-102 manufactured by Nipponpaint Industrial Coatings Co., LTD.

[1197] <Production of the original offset printing plate>

[1198] As described in Tables 4 to 6, original offset printing plates for Examples 1 to 18, and Comparative Examples 1 and 2 were produced according to the methods of forming the support and the aforementioned layers, respectively.

[1199] <Evaluation of the original lithographed version>

[1200] [UV printing durability]

[1201] Using a Kodak Magnus800 Quantum equipped with an infrared semiconductor laser, the original lithographic printing plate produced in the above manner was exposed (equivalent to an irradiation energy of 110 mJ / cm²) under the following conditions: output power of 27 W, external drum speed of 450 rpm, and resolution of 2,400 dpi (dots per inch, 1 inch is 2.54 cm). 2 The exposed image includes a solid image and an amplitude modulation screen with 3% dots.

[1202] The obtained exposed original was mounted on the cylinders of a Heidelberger Druckmaschinen AG printing press (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&KUV 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 carried out at a rate of 10,000 sheets per hour on Tokubishi Art (manufactured by Mitsubishi Paper Mills Limited, continuous yield 76.5kg) paper.

[1203] As the number of printed sheets increases, the image area gradually wears down, resulting in a decrease in ink density on the printed material. Print durability was evaluated by determining the number of sheets printed when the dot area ratio of 3% halftone dots in the printed material, measured using a Gretag density meter (manufactured by Gretag Macbeth), decreased by 1% compared to the measurement on the 500th sheet. Relative print durability was evaluated based on a print run of 50,000 sheets set as 100. A higher value indicates better print durability.

[1204] Relative print durability = (Number of prints of the original offset printing plate) / 50,000 × 100

[1205] [UV plate wear inhibition]

[1206] Using a Kodak Magnus800 Quantum equipped with an infrared semiconductor laser, the original lithographic printing plate produced in the above manner was exposed (equivalent to an irradiation energy of 110 mJ / cm²) under the following conditions: output power of 27 W, external drum speed of 450 rpm, and resolution of 2,400 dpi (dots per inch, 1 inch is 2.54 cm). 2 The exposed image includes a solid image and an amplitude-modulated screened image with 3% dots.

[1207] A 0.4mm diameter piano wire (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 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&K TOKA 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 Art (manufactured by Mitsubishi Paper Mills Limited, continuous yield: 76.5kg) paper at a printing speed of 10,000 sheets per hour.

[1208] 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.

[1209] Furthermore, the more prints that are completed before ink defects occur, the better the "UV plate wear suppression" can be.

[1210] -Evaluation Criteria-

[1211] A: The number of printed sheets before the ink defect occurs is more than 20,000.

[1212] B: The number of printed sheets before the occurrence of poor ink application is more than 4,000 but less than 20,000.

[1213] C: The number of printed sheets before the occurrence of poor ink application is less than 4,000.

[1214] [GLV Suitability Evaluation]

[1215] An exposure machine (PlateRite HD 8900N series, manufactured by SCREEN Graphic Solutions Co., Ltd.) equipped with an exposure head using GLV (Grating Light Valve) technology was used at 110 mJ / cm². 2 The exposure energy was used to expose the original lithographic printing plate produced in the manner described above. The exposed image includes a graph of an amplitude modulation (AM) halftone screen of 200 lines and a frequency modulation (FM) halftone screen of 20 μm.

[1216] The obtained exposed original was not developed and instead mounted on a SOR-M monochrome printing press (manufactured by Heidelberger Druckmaschinen AG). The ink used was Fusion-G MK Red N (manufactured by DIC CORPORATION), dampening solution was S-S 22% diluted (manufactured by Fujifilm Corporation), blanket was DAY Blanket D 3000 (manufactured by T&K TOKA Corporation), and paper was Tokubishi Art 127.9 gsm (g / m³). 2 (Manufactured by Mitsubishi PaperMills Limited) 1,000 sheets were printed. Then, the degree of unevenness in the striped pattern was sensorily evaluated by the naked eye from the 1,000th printed sheet. In other words, the less unevenness in the striped pattern is visible, the better the GLV suitability.

[1217] -Evaluation Criteria-

[1218] A: No striped unevenness was observed in either FM or AM screening.

[1219] B: Only a few striped inhomogeneities were observed with frequency modulation and screening.

[1220] C: A few striped inhomogeneities were observed in both frequency modulation (FM) and amplitude modulation (AM) screenings.

[1221] D: Striped unevenness was observed in both frequency modulation (FM) and amplitude modulation (AM) screening.

[1222] [Time-bound stability evaluation]

[1223] The developability evaluation result of the original lithographic printing plate (which is prepared and coated within 2 days and kept at room temperature for no more than 3 days after the plate is made) is set as D(Fr) sheet. When the developability of the plate that has been stored at 50°C and 70% RH for 3 days is set as D(Th) sheet, the time stability ΔD of the plate is calculated by the following formula.

[1224] ΔD=D(Th) / D(Fr)

[1225] The closer the value of ΔD is to 1, the better the stability over time.

[1226] -Evaluation Criteria-

[1227] A: 1.0 ≤ ΔD ≤ 1.5

[1228] B: 1.5 ≤ ΔD ≤ 2.0

[1229] C: 2.0 ≤ ΔD

[1230] [Table 4]

[1231]

[1232] [Table 5]

[1233]

[1234]

[1235] [Table 6]

[1236]

[1237] Additionally, ΔE1 represents the LUMO value of the electron-dependent polymerization initiator versus the LUMO value of the infrared absorber.

[1238] As can be seen from the results recorded in Tables 4 to 6, the lithographic printing plate originals involved in the embodiments, compared with the lithographic printing plate originals involved in the comparative examples, can obtain lithographic printing plate originals with excellent stability over time. Furthermore, it can be seen that the lithographic printing plate originals involved in the present invention can obtain lithographic printing plates with excellent UV printing durability, UV plate wear resistance, and visual recognizability.

[1239] (Examples 19 to 23)

[1240] <Fabrication of Support Z>

[1241] In Examples 19 to 23, the support body Z was fabricated through the following steps.

[1242] -Alkali etching treatment-

[1243] Etching was performed on an aluminum plate by spraying an aqueous solution of caustic soda (26% by mass) and aluminum ions (6.5% by mass) using a sprayer at 55°C. A spray-based water wash was then performed. The aluminum dissolution rate on the surface after electrochemical roughening was 3 g / m². 2 .

[1244] - Decontamination treatment using acidic aqueous solution (first decontamination treatment) -

[1245] Next, a decontamination treatment was performed using an acidic aqueous solution. The acidic aqueous solution used was a 170 g / L sulfuric acid solution at a temperature of 30°C. The acidic aqueous solution was sprayed onto the aluminum plate using a sprayer and the decontamination was performed for 3 seconds. Then, a water rinse was performed.

[1246] -Electrochemical roughening treatment-

[1247] Next, electrochemical roughening treatment was performed using a hydrochloric acid electrolyte and alternating current. The electrolyte temperature was 40°C. The process was conducted under conditions where the alternating current waveform was a symmetrical sine wave with positive and negative phases at a frequency of 50 Hz. Furthermore, the total charge, calculated as the charge participating in the anode reaction on the aluminum plate, was 300 C / dm³. 2 The process was carried out under specific conditions. A carbon electrode was used as the counter electrode in the aluminum plate. Then, a water washing process was performed.

[1248] -Alkali etching treatment-

[1249] At 35°C, an aqueous solution of caustic soda with a concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass was sprayed onto an electrochemically roughened aluminum plate using a sprayer, with an etching rate of 0.1 g / m. 2 The etching process was performed as follows. Then, a water washing process was carried out.

[1250] -Decontamination treatment using acidic aqueous solution-

[1251] Next, a decontamination treatment was performed using an acidic aqueous solution. The acidic aqueous solution used was a 170 g / L sulfuric acid solution at a temperature of 30°C. The acidic aqueous solution was sprayed onto the aluminum plate using a sprayer and the decontamination was performed for 3 seconds. Then, a water rinse was performed.

[1252] -Anodizing Treatment-

[1253] Under conditions of sulfuric acid concentration of 170 g / L and liquid temperature of 40 °C, using direct current, the anodic oxide film thickness is 3 g / m. 2 The process involved anodizing.

[1254] <Methods for forming the base coating>

[1255] On the support shown in Table 7, the dry coating amount is 20 mg / m². 2 The primer coating liquid described in Table 7 was applied in the manner described above and dried in an oven at 100°C for 30 seconds to form the primer coating.

[1256] <Formation of Image Recording Layer>

[1257] The image recording layer coating solution with the composition listed in Table 7 (wherein the image recording layer coating solution contains each component listed in Table 7, and is prepared with a solid content of 6% by mass using a mixed solvent of 1-methoxy-2-propanol (MFG):methyl ethyl ketone (MEK):methanol = 4:4:1 (mass ratio)) was rod-coated onto a support or primer and dried at 120°C for 40 seconds, thereby forming a dry coating weight of 1.0 g / m². 2 Image recording layer.

[1258] <Formation of the outermost layer>

[1259] The outermost coating solution with the composition listed in Table 7 (wherein the outermost coating solution contains all the components listed in Table 7 and is prepared by deionized water to a solid content of 6% by mass) was applied to the image recording layer and dried at 120°C for 60 seconds, thereby forming a dry coating weight of 0.15 g / m². 2 The outermost layer.

[1260] <Production of the original offset printing plate>

[1261] As shown in Table 7, original offset printing plates for Examples 19 to 23 were produced according to the methods of forming the support and the aforementioned layers, respectively.

[1262] Using the obtained original lithographic printing plate, various evaluations were performed in the same manner as in Example 1, and the evaluation results are shown in Table 7.

[1263] [Table 7]

[1264]

[1265]

[1266] The following shows the details of the abbreviations listed in Table 7, in addition to those mentioned above.

[1267] <Infrared absorber>

[1268] IR-11~IR-14: The following compounds

[1269] Additionally, TsO- This indicates the p-toluenesulfonate anion.

[1270] [Chemical Formula 86]

[1271]

[1272] [Chemical Formula 87]

[1273]

[1274] <surfactants>

[1275] U'-1 and U'-2: the following compounds

[1276] U'-3: Anionic surfactant, RAPISOL A-80, manufactured by NOF CORPORATION.

[1277] [Chemical Formula 88]

[1278]

[1279] As shown in Table 7, the lithographic printing plate originals involved in the embodiments exhibit superior stability over time compared to the lithographic printing plate originals involved in the comparative examples. Furthermore, it is evident that the lithographic printing plate originals involved in this invention provide lithographic printing plates with excellent UV printing durability, UV plate wear resistance, and visual recognizability.

[1280] Symbol Explanation

[1281] ta - Anode reaction time, tc - Cathode reaction time, tp - Time from 0 to peak current, Ia - Peak current on the anode circulation side, Ic - Peak current on the cathode circulation side, AA - Anode reaction current of the aluminum plate, CA - Cathode reaction current of the aluminum plate, 2 and 4 - Roller brush, 3 - Grinding slurry, 5, 6, 7 and 8 - Support rollers, 10 - Original plate for lithography, 12a, 12b - Aluminum support, 18 - Aluminum plate, 20a, 20b - Anodized film, 22a, 22b - Micropores, 24 - Large diameter hole, 26 - Small diameter hole, D - Large diameter The depth of the 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, S-supply direction, Ex-electrolyte discharge direction, 610-anodic oxidation treatment device, 612-power supply tank, 614-electrolytic treatment tank, 616-aluminum plate, 618, 626-electrolyte, 620-power supply electrode, 622, 628-roller, 624-clamping roller, 630-electrolytic electrode, 632-tank wall, 634-DC power supply.

[1282] The entire contents of the publications of Japanese Patent Application No. 2020-095076, filed on May 29, 2020, and Japanese Patent Application No. 2020-124464, filed on July 21, 2020, are incorporated herein by reference.

[1283] 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.

Claims

1. An on-machine developing type lithographic printing plate master, which sequentially comprises a support, an image recording layer, and an outermost layer. The image recording layer contains an infrared absorber, an electron-accepting polymerization initiator, and a polymerization compound. The LUMO value of the electron-accepting polymerization initiator minus the LUMO value of the infrared absorber is 0.45 eV or higher. The outermost layer contains a color-changing compound. The infrared absorber comprises a compound represented by the following formula 1. In Formula 1, R1 and R2 independently represent hydrogen atoms or alkyl groups, and R1 and R2 are optionally linked together to form a ring. R3 to R6 independently represent hydrogen atoms or alkyl groups, R7 and R8 independently represent alkyl or aryl groups, Y1 and Y2 independently represent oxygen atoms, sulfur atoms, -NR0- or dialkylmethylene groups, R0 represents hydrogen atoms, alkyl groups or aryl groups, Ar1 and Ar2 independently represent groups forming benzene or naphthalene rings that optionally have groups represented by Formula 2 as described later, and A1 represents -NR9R. 10 -X1-L1 or the group represented by Formula 2 as described later, R9 and R 10 Each of Ar1 and Ar2 independently represents an alkyl, aryl, alkoxycarbonyl, or arylsulfonyl group; X1 represents an oxygen or sulfur atom; L1 represents a hydrocarbon, heteroaryl, or a group whose bond with X1 is broken by heat or infrared exposure; Za represents a counterion that neutralizes the charge; and at least one of Ar1 and Ar2 has a group represented by the following formula 2. -X Formula 2 In Equation 2, X represents a halogen atom, -C(=O)-X2-R 11 -C(=O)-NR 12 R 13 -OC (=O) -R 14 -CN, -SO2NR 15 R 16 Or perfluoroalkyl, X2 represents a single bond or oxygen atom, R 11 and R 14 Each can be independently represented by an alkyl or aryl group, R 12 R 13 R 15 and R 16 Each can independently represent a hydrogen atom, alkyl group, or aryl group. The compound represented by Formula 1 has two or more halogen atoms selected from chlorine and bromine atoms.

2. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The LUMO of the electron-accepting polymerization initiator and the LUMO of the infrared absorber are greater than 0.62 eV.

3. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The LUMO of the infrared absorber is less than -3.80 eV.

4. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, At least one of Ar1 and Ar2 in Formula 1 has a halogen atom.

5. The on-machine developing type lithographic printing plate original according to claim 4, wherein, At least one of Ar1 and Ar2 in Formula 1 has a bromine atom.

6. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The LUMO of the electron-accepting polymerization initiator is greater than -3.2 eV.

7. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The electron-accepting polymerization initiator is an onium salt compound.

8. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The electron-accepting polymerization initiator comprises a compound represented by the following formula (II), In equation (II), X A R represents a halogen atom. A It indicates an aryl group.

9. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The polymeric compound comprises polymeric compounds with two or fewer functions.

10. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The image recording layer also contains polyvinyl acetal.

11. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The outermost layer contains a hydrophobic polymer.

12. The on-machine developing type lithographic printing plate original according to claim 11, wherein, The hydrophobic polymer is hydrophobic polymer particles.

13. The on-machine developing type lithographic printing plate original according to claim 1 or 2, 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.

14. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The color-changing compounds include compounds that develop color upon exposure to infrared light.

15. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The color-changing compound includes decomposable compounds that decompose upon exposure to infrared light.

16. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The color-changing compound is anthocyanin.

17. The on-machine developing type lithographic printing plate original according to claim 1 or 2, 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 2-1 to 4-1. 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 -N (R). 10 )-,R 10 Represents a hydrogen atom, alkyl group, or aryl group; Za represents a counter ion that neutralizes the charge. In equations 2-1 to 4-1, 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.

18. The on-machine developing type lithographic printing plate original according to claim 17, 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 formulas 2-1 to 4-1. 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 Represent -R independently 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 -N (R). 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.

19. The on-machine developing type lithographic printing plate original according to claim 17, 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 formulas 2-1 to 4-1. 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 -N (R). 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.

20. The on-machine developing type lithographic printing plate original according to claim 18, 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.

21. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The image recording layer also includes an electron-donating polymerization initiator.

22. The on-machine developing type lithographic printing plate original according to claim 21, wherein, The electron-donating polymerization initiator is a borate compound.

23. The on-machine developing type lithographic printing plate original according to claim 21, comprising a compound formed by forming a salt of a cation having the electron-accepting polymerization initiator structure and an anion having the electron-donating polymerization initiator structure as the electron-accepting polymerization initiator and the electron-donating polymerization initiator.

24. The on-machine developing type lithographic printing plate original according to claim 21, wherein, The HOMO value of the infrared absorber and the HOMO value of the electron-donating polymerization initiator are below 0.70 eV.

25. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The polymeric compound comprises polymeric compounds with seven or more functions.

26. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The polymeric compound comprises polymeric compounds with 10 or more functions.

27. The on-machine developing type lithographic printing plate original according to claim 1 or 2, wherein, The support 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.

28. The on-machine developing type lithographic printing plate original according to claim 27, wherein, The micropores are formed by large-diameter pores and small-diameter pores. The large-diameter pores extend from the surface of the anodic oxide film to a depth of 10 nm to 1000 nm. The small-diameter pores are connected to the bottom of the large-diameter pores and extend from the connection point to a depth of 20 nm to 2000 nm. The average diameter of the large-diameter holes on the surface of the anodic oxide film is 15 nm to 100 nm. The average diameter of the small-diameter hole at the connecting position is less than 13 nm.

29. A method for producing a lithographic printing plate, comprising: The process of exposing the machine-developable lithographic printing plate original as described in any one of claims 1 to 28 in an image-like manner; and A process of supplying at least one of the group consisting of printing ink and dampening solution to remove the image recording layer of a non-image section on a printing press.

30. A method for offset printing, comprising: The process of exposing the machine-developable lithographic printing plate original as described in any one of claims 1 to 28 in an image-like manner; The process of producing a lithographic printing plate by supplying at least one of a group consisting of printing ink and dampening solution to remove the image recording layer (excluding the image portion) on a printing press; and The process of printing using the obtained lithographic printing plate.

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