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 outer coating layer. The aforementioned outer coating layer does not contain inorganic compounds, or the content of inorganic compounds relative to the total mass of the aforementioned outer coating layer is greater than 0% by mass and less than 1% by mass. The aforementioned image recording layer comprises an infrared absorber, a polymerization initiator, a polymerizable compound, and an oil.

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 properties of water and oil-based inks. The oleophilic image area of ​​the lithographic printing plate serves as the ink receiving area, while the hydrophilic non-image area serves as the dampening solution receiving area (non-ink receiving area). This difference in ink adhesion is created on the surface of the lithographic printing plate, causing the ink to adhere only to the image area. The ink is then transferred to the substrate, such as paper, for printing.

[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 remaining as the image area. This remaining portion is then removed by dissolving it with an alkaline developer or organic solvent, thus exposing the surface of the hydrophilic support and forming a non-image area.

[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 lithographic printing plate original, wherein a water-soluble or water-dispersible negative image recording layer is formed on a hydrophilic aluminum support, and the arithmetic mean height Sa of the outer coating surface on the side opposite to the side having the image recording layer is 0.3 μm or more and 20 μm or less, wherein the image recording layer contains an infrared absorber and thermoplastic polymer particles.

[0009] Patent Document 2 describes a lithographic printing plate original, which has a substrate and an image forming layer on the substrate. The image forming layer can be removed by one of ink and dampening solution or both ink and dampening solution. In the lithographic printing plate original, the image forming layer comprises (A) at least one free radical polymerization initiator and (B) at least one free radical polymerizable group, and a free radical polymerizable compound having at least one urethane bond and at least two separate urea bonds or at least one urea bond and at least two separate urethane bonds.

[0010] Furthermore, as a conventional method for producing lithographic printing plates, the method for producing lithographic printing plates described in Patent Document 3 can be cited as an example.

[0011] Patent Document 3 discloses a method for manufacturing a lithographic printing plate, which sequentially includes: an exposure step in which a positive lithographic printing plate having an image recording layer on a support is exposed to form an image; and a development step in which the exposed positive lithographic printing plate is developed using a developing solution to form an image portion and a non-image portion. The image recording layer comprises an infrared absorber and a polymer A having acid groups and a base group, or a polymer B having acid groups and a polymer C having base groups. The content of the polymer A or the total content of the polymers contained in the image recording layer is 10% by mass or more relative to the total mass of the polymers contained in the image recording layer, and the pKa of the acid groups of the polymer A or the polymer B is 9 or less. The method for manufacturing the lithographic printing plate does not include a washing step after the development step in which the developed lithographic printing plate is washed with water.

[0012] Patent Document 1: Japanese Patent Application Publication No. 2019-64269

[0013] Patent Document 2: Japanese Patent Application Publication No. 2016-155271

[0014] Patent Document 3: Japanese Patent Application Publication No. 2020-160348 Summary of the Invention

[0015] The technical problem to be solved by the invention

[0016] One embodiment of the present invention aims to solve the problem of providing an in-machine developable offset printing plate with excellent printing durability, in-machine developability, and dampening solution turbidity suppression properties of ultraviolet curable ink (UV ink).

[0017] 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.

[0018] means for solving technical problems

[0019] The following methods are among the ways to solve the above problems.

[0020] <1> An on-machine developing type lithographic printing plate master, which sequentially comprises a support, an image recording layer and an outer coating, wherein the outer coating does not contain inorganic compounds, or the content of inorganic compounds is more than 0% by mass and less than 1% by mass relative to the total mass of the outer coating, and the image recording layer comprises an infrared absorber, a polymerization initiator, a polymerizable compound and an oil.

[0021] <2> The original plate for machine-developable offset printing as described in <1>, wherein the above-mentioned oil contains an oil with a boiling point of 300°C or higher.

[0022] <3> The original plate for machine-developable lithographic printing as described in <1> or <2>, wherein the above-mentioned oil contains two or more oils with different structures.

[0023] <4> The original plate for machine-developable lithographic printing according to any one of <1> to <3>, wherein the clogP value of the above-mentioned oil is 5.0 or more.

[0024] <5> The original plate for machine-developable lithographic printing according to any one of <1> to <4>, wherein the oil comprises an oil having an aromatic ring.

[0025] <6> The original plate for machine-developable lithographic printing according to any one of <1> to <5>, wherein the oil comprises an oil having phosphorus atoms.

[0026] <7> The original plate for machine-developable lithographic printing according to any one of <1> to <6>, wherein the polymerization initiator comprises an electron-donating polymerization initiator.

[0027] <8> The on-machine developing type lithographic printing plate original as described in <7>, wherein the electron-donating polymerization initiator is a borate compound.

[0028] <9> The original plate for machine-developable lithographic printing according to <7> or <8>, wherein the HOMO value of the infrared absorber and the HOMO value of the electron-donating polymerization initiator are 0.70 eV or less.

[0029] <10> The original plate for machine-developable lithographic printing according to any one of <1> to <9>, wherein the polymerization initiator comprises an electron-accepting polymerization initiator, and the LUMO of the electron-accepting polymerization initiator minus the LUMO of the infrared absorber is 0.70 eV or less.

[0030] <11> The original plate for machine-developable lithographic printing according to any one of <1> to <10>, wherein the polymeric compound comprises a polymeric compound with seven or more functions.

[0031] <12> The original plate for machine-developable lithographic printing according to any one of <1> to <11>, wherein the polymeric compound comprises a polymeric compound with 10 or more functions.

[0032] <13> The original plate for machine-developable lithography according to any one of <1> to <12>, wherein the image recording layer further comprises polymer particles.

[0033] <14> The original plate for machine-developable lithographic printing according to any one of <1> to <13>, wherein the outer coating comprises a hydrophilic polymer.

[0034] <15> The on-machine developing type lithographic printing plate original according to <14>, wherein the hydrophilic polymer comprises a cellulose derivative.

[0035] <16> The original plate for machine-developable lithographic printing according to any one of <1> to <15>, wherein the polymeric compound comprises a polymeric compound with two or fewer functions.

[0036] <17> The on-machine developing type lithographic printing plate original according to <10>, wherein the above-mentioned electron-receiving polymerization initiator comprises a compound represented by the following formula (II).

[0037] [Chemical Formula 1]

[0038]

[0039] In equation (II), X A R represents a halogen atom. A It represents an aryl group.

[0040] <18> The original plate for machine-developable lithographic printing according to any one of <1> to <17>, wherein the image recording layer further comprises polyvinyl butyral.

[0041] <19> The original plate for machine-developable lithographic printing according to any one of <1> to <18>, wherein the outer coating comprises a hydrophobic polymer.

[0042] <20> The original plate for machine-developable offset printing as described in <19>, wherein the hydrophobic polymer is hydrophobic polymer particles.

[0043] <21> The original plate for machine-developable lithographic printing according to any one of <1> to <20>, wherein the outer coating further comprises a color-changing compound.

[0044] <22> The original plate for machine-developable lithographic printing according to <21>, wherein the aforementioned color-changing compound includes a decomposing compound that decomposes due to infrared exposure.

[0045] <23> The original plate for machine-developable lithographic printing as described in <21> or <22>, wherein the aforementioned color-changing compound is anthocyanin.

[0046] <24> The original plate for machine-developable lithographic printing according to any one of <21> to <23>, wherein the color-changing compound is a compound represented by the following formula 1-1.

[0047] [Chemical Formula 2]

[0048]

[0049] 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 10 It represents a hydrogen atom, alkyl group, or aryl group; Za represents a counterion that neutralizes the charge.

[0050] [Chemical Formula 3]

[0051]

[0052] In equations 2-1 to 4-1, R 20 R 30 R 41 and R 42Each 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 above.

[0053] <25> The original plate for machine-developable lithographic printing according to any one of <21> to <24>, wherein the color-changing compound is a compound represented by the following formulas 1-2.

[0054] [Chemical Formula 4]

[0055]

[0056] 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.

[0057] <26> The original plate for machine-developable lithographic printing according to any one of <21> to <25>, wherein the color-changing compound is a compound represented by any one of the following formulas 1-3 to 1-7.

[0058] [Chemical Formula 5]

[0059]

[0060] 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.

[0061] <27> According to <25> or <26>, the on-machine developing type lithographic printing plate original, wherein,

[0062] 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-, a sulfonyl group, a salt of a sulfonyl group, a carboxyl group, or a salt of a carboxyl group as the above substituent.

[0063] <28> A method for manufacturing a lithographic printing plate, comprising: a step of exposing an on-machine developing type lithographic printing plate master as described in any one of <1> to <27> into an image; and a step of supplying at least one of printing ink and dampening solution to a printing press to remove the non-image portion of the image recording layer.

[0064] <29> A lithographic printing method comprising: a step of exposing an on-machine developing type lithographic printing plate master as described in any one of <1> to <27> into an image; a step of producing a lithographic printing plate by supplying at least one of printing ink and dampening solution to remove an image recording layer of non-image portion on a printing press; and a step of printing using the obtained lithographic printing plate.

[0065] Invention Effects

[0066] According to one embodiment of the present invention, an in-machine developable offset printing plate master with excellent UV ink printing durability, in-machine developability, and dampening solution turbidity suppression can be provided.

[0067] 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

[0068] Figure 1 This is a schematic diagram of the process of this invention. Detailed Implementation

[0069] 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.

[0070] 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.

[0071] 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).

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] Furthermore, in this invention, a combination of two or more preferred methods is a more preferred method.

[0077] 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.

[0078] 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.

[0079] 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 inks (UV inks) as inks during printing will also be referred to as "UV ink printing durability" or simply "UV printing durability".

[0080] The present invention will now be described in detail.

[0081] (Original plate for in-machine developing offset printing)

[0082] The on-machine developing type lithographic printing plate master (also referred to as "lithographic printing plate master") involved in this invention has a support, an image recording layer and an outer coating layer in sequence. The outer coating layer does not contain inorganic compounds, or the content of inorganic compounds relative to the total mass of the outer coating layer is more than 0% by mass and less than 1% by mass. The image recording layer contains an infrared absorber, a polymerization initiator, a polymerizable compound and an oil.

[0083] Furthermore, the on-machine developing type lithographic printing plate original involved in this invention can be a negative lithographic printing plate original or a positive lithographic printing plate original, but it is preferred to be a negative lithographic printing plate original.

[0084] The inventors have discovered that in conventional on-machine developable lithographic printing plates, at least one of the following—UV ink printing durability, on-machine developability, and dampening solution turbidity suppression—is sometimes insufficient.

[0085] Through in-depth research, the inventors discovered that by adopting the above-described structure, it is possible to provide an in-machine developable offset printing plate with excellent UV ink printing durability, in-machine developability, and dampening solution turbidity suppression.

[0086] While the detailed mechanism by which the above effects are achieved is unclear, the following speculations are made.

[0087] It is inferred that the outer coating does not contain inorganic compounds, or that the content of inorganic compounds is greater than 0% by mass and less than 1% by mass relative to the total mass of the outer coating, and that the image recording layer contains an oil, thereby suppressing the turbidity of the dampening solution caused by inorganic compounds in the outer coating, and further hydrophobizing the image recording layer by the oil, suppressing the dissolution and dispersion of the image recording layer and its components in the dampening solution, and while maintaining the hydrophobicity of the image recording layer by containing an oil, the permeability of the dampening solution to the image recording layer is improved due to the plasticizing effect, giving high UV ink printing durability and excellent on-machine developability.

[0088] The following is a detailed description of each component of the original offset printing plate involved in this invention.

[0089] <Image Recording Layer>

[0090] The lithographic printing plate of the present invention comprises a support, an image recording layer and an outer coating layer, wherein the image recording layer comprises an infrared absorber, a polymerization initiator, a polymerization compound and an oil.

[0091] [Oil-based]

[0092] The image recording layer described above contains an oil.

[0093] The oil in this invention refers to a hydrophobic compound that is liquid at 80°C and separates without mixing when mixed with the same mass of water.

[0094] In addition, when using two or more oils, even if they contain compounds with a melting point of 80°C or higher, it is acceptable as long as the mixture of two or more oils remains liquid at 80°C.

[0095] Furthermore, from the viewpoint of machine developability and dampening solution turbidity suppression, the above-mentioned oil is preferably a compound with a molecular weight of less than 1,000, more preferably a compound with a molecular weight of 200 to 800, and especially preferably a compound with a molecular weight of 300 to 500.

[0096] Furthermore, from the viewpoint of machine developability and dampening solution turbidity suppression, the above-mentioned oil is preferably a compound with a boiling point of 200°C or higher at 1 atmosphere, more preferably a compound with a boiling point of 250°C or higher at 1 atmosphere, even more preferably a compound with a boiling point of 300°C or higher at 1 atmosphere, and particularly preferably a compound with a boiling point of 400°C or higher and 500°C or lower at 1 atmosphere.

[0097] In addition, unless otherwise specified in this invention, the term "boiling point" refers to the boiling point at 1 atmosphere.

[0098] Furthermore, from the viewpoint of machine developability and dampening solution turbidity suppression, the melting point of the above-mentioned oil at 1 atmosphere is preferably 50°C or less, more preferably 30°C or less, and especially preferably -200°C or more and 25°C or less.

[0099] In addition, unless otherwise specified in this invention, the term "melting point" refers to the melting point at 1 atmosphere.

[0100] Examples of such oils include phosphate ester compounds, aromatic hydrocarbon compounds, glycerol ester compounds, fatty acid compounds, and aromatic ester compounds.

[0101] From the viewpoints of UV printing durability, ink adhesion, on-machine developability, and dampening solution turbidity suppression, at least one compound selected from phosphate ester compounds, aromatic hydrocarbon compounds, glycerol ester compounds, and aromatic ester compounds is preferred; more preferably, at least one compound selected from phosphate ester compounds, aromatic hydrocarbon compounds, and glycerol ester compounds is preferred; even more preferably, at least one compound selected from phosphate ester compounds and aromatic hydrocarbon compounds is preferred; and phosphate ester compounds are particularly preferred.

[0102] From the viewpoints of UV printing durability, ink adhesion, on-machine developability, and dampening solution turbidity suppression, triphosphate compounds are preferred as phosphate compounds, triaryl phosphate compounds are more preferred, tricresyl phosphate is even more preferred, and mixtures of two or more of the ortho, meta, and para positions of tricresyl phosphate are particularly preferred.

[0103] From the viewpoint of machine developability and dampening solution turbidity suppression, compounds having two or more aromatic rings are preferred as aromatic hydrocarbon compounds, and compounds having two or more unfused benzene rings are more preferred.

[0104] From the viewpoint of machine developability and dampening solution turbidity suppression, triglyceride compounds are preferred as glyceride compounds, and fatty oils are more preferred, especially fatty oils such as castor oil that are liquid at 25°C.

[0105] From the viewpoint of machine developability and dampening solution turbidity suppression, unsaturated fatty acids are preferred as fatty acid compounds, more preferably unsaturated fatty acids with 8 to 30 carbon atoms, and especially preferably unsaturated fatty acids with 12 to 24 carbon atoms.

[0106] From the viewpoint of machine developability and dampening solution turbidity suppression, aromatic diester compounds are preferred as aromatic ester compounds, and aromatic diester compounds having aliphatic rings are more preferred.

[0107] From the viewpoint of machine developability and dampening solution turbidity suppression, aliphatic ester compounds having branched alkyl groups are preferred as aliphatic ester compounds, and aliphatic ester compounds having branched alkyl groups and having 10 to 24 carbon atoms are more preferred.

[0108] From the viewpoints of UV printing durability, ink adhesion, on-machine developability, and dampening solution turbidity suppression, oils containing phosphorus atoms are preferred, and oils containing phosphorus atoms are more preferred.

[0109] Furthermore, from the viewpoint of machine developability and dampening solution turbidity suppression, the oils described above preferably contain aromatic rings, more preferably contain two or more aromatic rings, and especially preferably contain two or more unfused benzene rings.

[0110] From the viewpoints of UV printing durability, ink adhesion, on-machine developability, and dampening solution turbidity suppression, the clogP value of the above-mentioned oil is preferably 5.0 or higher, more preferably 5.50 or higher, even more preferably 5.50 or higher and 10.0 or lower, and particularly preferably 5.60 or higher and 7.00 or lower.

[0111] The clogP value is the value obtained by calculating the common logarithm logP of the partition coefficient P of 1-octanol and water. While known methods and software can be used to calculate the clogP value, the ClogP program written in Cambridge Soft's ChemBioDraw Ultra 12.0 is used in this invention unless otherwise specified.

[0112] Specifically, examples of the aforementioned oils include tricresyl phosphate, dimethyl (1-phenylethyl)benzene, 2,4-diphenyl-4-methyl-1-pentene, dicyclohexyl phthalate, castor oil, α-linolenic acid, and tris(2-ethylhexyl) phosphate.

[0113] The aforementioned oils may be used in one or more ways, but from the viewpoint of machine developability and dampening solution turbidity suppression, the aforementioned image recording layer preferably contains two or more oils with different structures.

[0114] The content of the above-mentioned oil agent is preferably 0.0001% to 10.0% by mass relative to the total mass of the image recording layer, more preferably 0.0002% to 1.0% by mass, even more preferably 0.0005% to 0.5% by mass, and especially preferably 0.001% to 0.05% by mass.

[0115] [Infrared absorber]

[0116] The image recording layer in this invention contains an infrared absorber.

[0117] There are no particular limitations on what can be used as an infrared absorber; for example, pigments and dyes can be cited.

[0118] 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 pigments, pyranium salts, and metal thiol complexes.

[0119] Preferred dyes among these dyes include anthocyanins, squaric acid dyes, pyranonium salts, nickel thiol complexes, and indocyanine dyes. Anthocyanins and indocyanine dyes are more preferred. Among these, anthocyanins are particularly preferred.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] Furthermore, as the aforementioned infrared absorber, it is preferable to use a color-changing compound that decomposes upon infrared exposure, as described later, which is a decomposable compound used as an outer coating.

[0124] 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.

[0125] From the viewpoint of stability over time, improved sensitivity, and UV printing durability, the minimum unoccupied molecular orbital (LUMO) of the above-mentioned infrared absorber is preferably less than -3.70 eV, more preferably less than -3.80 eV, even more preferably more than -4.20 eV and less than -3.80 eV, and especially preferably more than -4.00 eV and less than -3.80 eV.

[0126] Infrared absorbers can be used in one or more ways, but from the viewpoint of UV printing durability, on-machine developability and dampening solution turbidity suppression, the image recording layer preferably contains two or more infrared absorbers, more preferably two to four, and especially preferably two.

[0127] Furthermore, as an infrared absorber, it can be used in conjunction with pigments and dyes.

[0128] 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.

[0129] [Polymerization initiator]

[0130] The image recording layer in the lithographic printing plate original involved in this invention contains a polymerization initiator.

[0131] The polymerization initiator described above preferably includes an electron-donating polymerization initiator, and more preferably includes both an electron-accepting polymerization initiator and an electron-donating polymerization initiator.

[0132] Furthermore, from the viewpoint of visual recognizability and tone reproduction of the exposed portion, the image recording layer preferably further includes a polymerization initiator, and the decomposition products generated by the exposure are decomposition products generated by the exposure of the polymerization initiator. More preferably, it further includes an electron-donating polymerization initiator, and the decomposition products generated by the exposure are decomposition products generated by the exposure of the electron-donating polymerization initiator.

[0133] [Electron-donating polymerization initiators (polymerization aids)]

[0134] The image recording layer in the lithographic printing plate original involved in this invention preferably further includes an electron-donating polymerization initiator (also known as a "polymerization aid") as a polymerization initiator.

[0135] 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.

[0136] As an electron-donating polymerization initiator, an electron-donating free radical polymerization initiator is preferred.

[0137] From the viewpoint of visual recognizability and tone reproduction of the exposed part, the above-mentioned electron-donating polymerization initiator preferably contains a boron compound, more preferably a borate compound, even more preferably a tetraarylborate compound, and especially preferably a tetraphenylborate compound.

[0138] From the viewpoint of printability and visual recognizability, tetraarylborate compounds or monoalkyltriarylborate compounds are preferred as borate compounds, and tetraarylborate compounds are more preferred.

[0139] Furthermore, from the viewpoint of printability and visual recognizability, tetraarylborate compounds having one or more electron-donating or electron-withdrawing groups are preferred as borate compounds, and tetraarylborate compounds having one electron-donating or electron-withdrawing group in each aryl group are more preferred.

[0140] From the viewpoint of printability and visual recognizability, alkyl or alkoxy groups are preferred as electron-donating groups, and alkoxy groups are more preferred.

[0141] From the perspective of decomposition and visual recognition, examples of electron-withdrawing groups include halogen atoms, alkyl halides, acyl groups, and carboxyl groups.

[0142] 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.

[0143] 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.

[0144] As a borate compound, sodium tetraphenylborate is particularly preferred.

[0145] 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.

[0146] [Chemical Formula 6]

[0147]

[0148] Furthermore, from the viewpoint of improving sensitivity, 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.

[0149] Furthermore, as an upper limit, it is preferably below -5.00 eV, and more preferably below -5.40 eV.

[0150] Electron-donating polymerization initiators can be used alone or in combination with two or more.

[0151] From the viewpoint of sensitivity and printing durability, the content of the electron-donating polymerization initiator is preferably 0.01% to 30% by mass relative to the total mass of the image recording layer, more preferably 0.05% to 25% by mass, and even more preferably 0.1% to 20% by mass.

[0152] Furthermore, from the viewpoint of UV printing durability, the content of electron-donating polymerization initiator in the image recording layer is preferably greater than the content of infrared absorber, more preferably 1.1 to 5 times the content of infrared absorber, and especially preferably 1.5 to 3 times the content of infrared absorber.

[0153] In this invention, the polymerization initiator can be a compound that forms a countersalt with an electron-donating polymerization initiator and an electron-accepting polymerization initiator.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] The image recording layer of the present invention further comprises an infrared absorber and an electron-donating polymerization initiator. From the viewpoint of improving sensitivity and print durability, the HOMO value of the infrared absorber minus the HOMO value of the electron-donating polymerization initiator is preferably 0.70 eV or less, more preferably 0.60 eV or less, even more preferably 0.50 eV or less, and particularly preferably 0.50 eV to -0.10 eV.

[0160] 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.

[0161] 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.

[0162] First, free counterions in the compound being calculated are excluded from the calculation. For example, counterions are excluded from the calculation in cationic electron-accepting polymers and cationic infrared absorbers, and counterions are excluded from the calculation in anionic electron-donating polymers. Here, "free" means that the compound being calculated and its counterion are not covalently linked.

[0163] Structure optimization was performed using the quantum chemical calculation software Gaussian16 under DFT(B3LYP / 6-31G(d)).

[0164] 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)).

[0165] 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.

[0166] 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.

[0167] [HOMO calculation formula] Escaled = 0.823168 × 27.2114 × Ebare - 1.07634

[0168] [The formula for calculating LUMO] Escaled = 0.820139 × 27.2114 × Ebare - 1.086039

[0169] 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 UMO are adjustment coefficients, determined by matching the calculated and measured values ​​of HOMO and LUMO for the compounds being calculated.

[0170] Electron-receiving polymerization initiators

[0171] The image recording layer in this invention preferably further includes an electron-accepting polymerization initiator as a polymerization initiator.

[0172] 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.

[0173] 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.

[0174] As an electron-accepting polymerization initiator, a free radical polymerization initiator is preferred, and an onium salt compound is more preferred.

[0175] Furthermore, an infrared-sensitive polymerization initiator is preferred as the electron-receiving polymerization initiator.

[0176] Furthermore, from the viewpoint of improving sensitivity and UV printing durability, iodonium salt compounds or compounds containing alkyl halides are preferred as electron-accepting polymerization initiators, and compounds containing alkyl halides are more preferred.

[0177] Furthermore, from the viewpoint of improving sensitivity and UV printing durability, compounds having a fully halogenated alkyl sulfonyl group are preferred as compounds having a trihalogenated methanesulfonyl group, compounds having a tribromomethanesulfonyl group are more preferred, and compounds having a tribromomethanesulfonyl group are especially preferred as compounds having a tribromomethanesulfonyl group.

[0178] 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.

[0179] Specific examples of these compounds are shown below, but the invention is not limited thereto.

[0180] 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 (DIO) = hexafluorophosphate, 4-methoxyphenyl-4-(2-methylpropyl)phenyliodonium (DIO) = hexafluorophosphate, 4-(2-methylpropyl)phenyl-p-tolyliodonium (DIO) = hexafluorophosphate, 4-hexyloxyphenyl-2,4,6-trimethoxyphenyliodonium (DIO) = hexafluorophosphate, 4-hexyloxyphenyl-2,4-diethoxyphenyliodonium (DIO) = tetrafluoroborate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium (DIO) = 1-perfluorobutylsulfonate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium (DIO) = hexafluorophosphate, and bis(4-tert-butylphenyl)iodonium (DIO) = tetraphenylborate.

[0181] 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.

[0182] Among them, sulfonamide anion or sulfonamide anion is preferred, and sulfonamide anion is more preferred.

[0183] As a sulfonamide anion, arylsulfonamide anion is preferred.

[0184] Furthermore, bis(aryl)sulfonamide anion is preferred as the sulfonamide anion.

[0185] Specific examples of sulfonamide anions or sulfonamide anions include the compounds described in International Publication No. 2019 / 013268.

[0186] Furthermore, as the aforementioned electron-receiving polymerization initiator, from the viewpoint of the time-lapse visual recognizability after exposure, the developability, and the UV printing durability in the obtained lithographic printing plate, it is preferable to include a compound represented by formula (II) or formula (III) below, and it is particularly preferable to include a compound represented by formula (II).

[0187] [Chemical Formula 7]

[0188]

[0189] 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.

[0190] R in equation (II) A The preferred group is aryl.

[0191] 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.

[0192] 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.

[0193] Furthermore, as the aforementioned electron-receiving polymerization initiator, it is particularly preferred to include a compound represented by formula (IV).

[0194] [Chemical Formula 8]

[0195]

[0196] In equation (IV), X A R represents a halogen atom. A3 and R A4 Each group independently represents a hydrogen atom or a monovalent hydrocarbon group with 1 to 20 carbon atoms, and pA and qA independently represent integers from 1 to 5. Where pA + qA = 2 to 6.

[0197] Specific examples of electron-receiving polymerization initiators include the compounds shown below, but the present invention is not limited to these.

[0198] [Chemical Formula 9]

[0199]

[0200] [Chemical Formula 10]

[0201]

[0202] [Chemical Formula 11]

[0203]

[0204] [Chemical Formula 12]

[0205]

[0206] [Chemical Formula 13]

[0207]

[0208] [Chemical Formula 14]

[0209]

[0210] [Chemical Formula 15]

[0211]

[0212] From the viewpoint of improving sensitivity, the minimum unoccupied molecular orbital (LUMO) of the electron-accepted polymerization initiator is preferably -3.00 eV or less, more preferably -3.02 eV or less.

[0213] Furthermore, as a lower limit, it is preferably -3.80 eV or higher, and more preferably -3.50 eV or higher.

[0214] Electron-accepting polymerization initiators can be used alone or in combination with two or more.

[0215] The content of the electron-receiving polymerization initiator is preferably 0.1% to 50% by mass relative to the total mass of the image recording layer, more preferably 0.5% to 30% by mass, and especially preferably 0.8% to 20% by mass.

[0216] The image recording layer of the present invention further comprises an infrared absorber and an electron-accepting polymerization initiator. From the viewpoint of improving sensitivity and print durability, the LUMO of the electron-accepting polymerization initiator minus the LUMO of the infrared absorber is preferably 1.00 eV or less, more preferably 0.80 eV or less, further preferably 0.70 eV or less, particularly preferably 0.70 eV to -0.10 eV, and most preferably 0.70 eV to 0.30 eV.

[0217] 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.

[0218] [Polymerizing compounds]

[0219] The image recording layer in this invention contains a polymeric compound.

[0220] In this invention, a polymerizable compound refers to a compound having polymerizable groups.

[0221] 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.

[0222] Examples of free radical polymerizable groups include (meth)acryloyl, allyl, vinylphenyl, and vinyl groups. From a reactivity point of view, (meth)acryloyl is preferred.

[0223] 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.

[0224] The polymerizable compounds used in this invention may 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.

[0225] 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.

[0226] 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).

[0227] 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.

[0228] From the viewpoints of print durability, machine developability, and contamination inhibition, the content of polymeric compounds with two or fewer functions (preferably two-functional polymeric compounds) is preferably 5% to 100% by mass, more preferably 10% 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.

[0229] <<Oligomers>>

[0230] 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").

[0231] 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.

[0232] 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.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] In addition, it may contain polymer components that may be generated during the manufacturing process of oligomers.

[0237] From the viewpoints of UV printing durability, visual recognizability, and on-machine developability, the oligomer preferably comprises at least one selected from compounds having urethane bonds, compounds having ester bonds, and compounds having epoxy residues, and more preferably comprises a compound having urethane bonds.

[0238] 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.

[0239] Examples of oligomers include compounds having urethane bonds, preferably compounds having at least a group represented by formula (Ac-1) or formula (Ac-2), more preferably compounds having at least a group represented by formula (Ac-1).

[0240] [Chemical Formula 16]

[0241]

[0242] In equations (Ac-1) and (Ac-2), L 1 ~L 4Each group represents a divalent hydrocarbon group with 2 to 20 carbon atoms, and the wavy line indicates the bonding position with other structures.

[0243] 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.

[0244] 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).

[0245] [Chemical Formula 17]

[0246]

[0247] 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).

[0248] 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.

[0249] 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.

[0250] 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.

[0251] Examples of oligomers include compounds containing epoxy residues, preferably compounds containing hydroxyl groups within the compound.

[0252] Furthermore, the number of polymerizable groups in the compound having epoxy residues is preferably 2 to 6, more preferably 2 to 3.

[0253] For example, the above-mentioned compound having epoxy residues can be obtained by reacting acrylic acid with a compound having epoxy groups.

[0254] Specific examples of oligomers are shown below, but the oligomers used in this invention are not limited thereto.

[0255] Commercially available products can be used as oligomers, 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 NipponSynthetic 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.

[0256] From the viewpoint of improving chemical resistance, UV printing durability, and the ability to suppress 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.

[0257] <<Low molecular weight polymeric compounds>>

[0258] Polymerizable compounds may also include polymerizable compounds other than the oligomers mentioned above.

[0259] 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.

[0260] Furthermore, from the viewpoint of chemical resistance, the polymeric compound is preferably selected from at least one polymeric compound having three or more olefinic unsaturated groups and polymeric compounds having an isocyanurate ring structure.

[0261] 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.

[0262] 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.

[0263] 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.

[0264] 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.

[0265] 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.

[0266] From the perspective of UV printing durability, the image recording layer preferably contains two or more polymeric compounds.

[0267] The content of polymeric compounds (the total content of polymeric compounds when there are two or more polymeric compounds) 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.

[0268] 〔particle〕

[0269] From the viewpoint of developability and UV printing durability, the image recording layer of the present invention preferably further comprises particles. These particles can be inorganic or organic.

[0270] The particles preferably include organic particles, and more preferably resin particles (polymer particles).

[0271] 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.

[0272] <<Resin Particles>>

[0273] Examples of resin particles include particles containing addition-polymerized resin (i.e., addition-polymerized resin particles), particles containing addition-polymerized resin (i.e., addition-polymerized resin particles), and particles containing condensation-polymerized resin (i.e., condensation-polymerized resin particles), but addition-polymerized resin particles or addition-polymerized resin particles are preferred.

[0274] Furthermore, from the viewpoint that it can be thermally welded, the resin particles can be particles containing thermoplastic resin (i.e., thermoplastic resin particles).

[0275] Furthermore, the resin particles can be in the form of microcapsules, microgels (i.e., cross-linked resin particles), etc.

[0276] The resin particles are preferably selected from thermoplastic resin particles, thermally reactive resin particles, resin particles with polymerizable groups, microcapsules containing hydrophobic compounds, and microgels (crosslinked resin particles). Among these, resin particles with polymerizable groups are preferred.

[0277] 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.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] 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.

[0282] 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.

[0283] 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 resin, and even more preferably 30% to 70% by mass.

[0284] The nitrile-containing constituent units are preferably introduced using monomers having nitrile groups.

[0285] Acrylonitrile compounds are examples of monomers having a nitrile group, with (meth)acrylonitrile being a preferred example.

[0286] As a constituent unit having a nitrile group, a constituent unit formed of (meth)acrylonitrile is preferred.

[0287] 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.

[0288] 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.

[0289] 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.

[0290] 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.

[0291] The content of 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.

[0292] The resin contained in the thermoplastic resin particles may contain constituent units with acidic groups, but from the viewpoint of machine developability and ink adherence, it is preferable that the constituent units do not contain acidic groups.

[0293] 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.

[0294] 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.

[0295] In this invention, the acid value is determined in accordance with the determination method of JIS K0070:1992.

[0296] From the perspective of ink adhesion, the resin contained in thermoplastic resin particles may contain constituent units containing hydrophobic groups.

[0297] Examples of hydrophobic groups include alkyl, aryl, and aralkyl groups.

[0298] 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.

[0299] 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.

[0300] From the viewpoint of UV printing durability and machine developability, the thermoplastic resin contained in the thermoplastic resin particles preferably has hydrophilic groups.

[0301] 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.

[0302] 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.

[0303] 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.

[0304] 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.

[0305] 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.

[0306] Furthermore, from the viewpoint of machine developability, the hydrophilic group described below is preferably the group represented by formula Z.

[0307] Among the hydrophilic groups possessed by thermoplastic resins, those represented by the following formula PO are preferred.

[0308] [Chemical Formula 18]

[0309]

[0310] 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.

[0311] In formula PO, L P Each of the following is preferably ethylene, 1-methylethylene, or 2-methylethylene, and more preferably ethylene.

[0312] 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.

[0313] In formula PO, n is preferably an integer from 1 to 10, and more preferably an integer from 1 to 4.

[0314] The content of the constituent units having hydrophilic groups is preferably 5% to 60% by mass relative to the total mass of the resin, more preferably 10% to 30% by mass.

[0315] 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.

[0316] 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.

[0317] Examples of thermo-reactive resin particles include resin particles with thermo-reactive groups. These thermo-reactive resin particles form hydrophobic regions through cross-linking based on thermal reactions and changes in functional groups during cross-linking.

[0318] 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, methacryl, 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.

[0319] 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.

[0320] 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 outside of the microcapsule.

[0321] 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.

[0322] To obtain microcapsules containing the components of an image recording layer, known synthetic methods can be applied.

[0323] 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.

[0324] To obtain microgels containing components of an image recording layer, known synthetic methods can be applied.

[0325] 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.

[0326] As the aforementioned polyphenolic compounds, compounds having multiple benzene rings with phenolic hydroxyl groups are preferred.

[0327] As the compound possessing 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 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.

[0328] 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.

[0329] 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.

[0330] <<Groups represented by formula Z>>

[0331] The resin particles in this invention preferably have a group represented by the following formula Z as a hydrophilic group.

[0332] *-QWY formula Z

[0333] 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 a bonding site with other structures.

[0334] Furthermore, the hydrophilic structures included in preferred formula Z all contain polyepoxide structures.

[0335] 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.

[0336] 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 these groups, and more preferably a phenylene group, an ester bond, or an amide bond.

[0337] 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 - groups. Additionally, R W It represents a hydrogen atom or an alkyl group.

[0338] 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.

[0339] The monovalent group with a hydrophilic structure in Y of formula Z above is preferably -OH, -C(=O)OH, a polyalkoxide group with a hydrogen atom or alkyl group at the end, or a polyalkoxide group with -CH2CH2N(R) bonded to the other end. W The 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 )- group.

[0340] 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 indicates an alkyl group having 6 to 20 carbon atoms.

[0341] 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.

[0342] In addition, the group represented by formula Z can function as a dispersing group to improve the dispersibility of resin particles.

[0343] 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, print durability (preferably UV print durability) can be improved.

[0344] From the viewpoint of print durability, the resin particles in this invention are preferably resin particles having hydrophilic groups and polymeric groups.

[0345] 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.

[0346] As for the aforementioned polymerizable groups, there are no particular restrictions as long as they are polymerizable groups, but from the viewpoint of reactivity, olefinic unsaturated groups are preferred, more preferably vinylphenyl (styrene), (meth)acryloyloxy or (meth)acrylamido, and especially (meth)acryloyloxy.

[0347] Furthermore, the resin constituting the resin particles having polymerizable groups preferably has constituent units having polymerizable groups.

[0348] In addition, polymeric groups can be introduced onto the surface of resin particles through polymer reactions.

[0349] 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.

[0350] [Chemical Formula 19]

[0351]

[0352] In the formula (Iso), n represents an integer from 0 to 10.

[0353] As an example of the reaction of an isocyanate compound represented by the above formula (Iso) with water, the reaction shown below can be cited. Additionally, the following example is an example where n=0 and the 4,4-isomer is used.

[0354] 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 are hydrolyzed to produce an amino group. The resulting amino group reacts with the isocyanate group to form a urea bond, thus forming a dimer. Furthermore, by repeating the following reaction, an addition-polymerized resin containing urea bonds is formed.

[0355] Furthermore, in the following reaction, by adding compounds such as alcohols and amines that are reactive with isocyanate groups (compounds with active hydrogen), it is also possible to introduce the structure of alcohols and amines into addition polymers containing urea bonds.

[0356] As a compound having the aforementioned active hydrogen, a compound having the described active hydrogen is preferably mentioned.

[0357] [Chemical Formula 20]

[0358]

[0359] 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).

[0360] [Chemical Formula 21]

[0361]

[0362] In the formula (PETA), the wavy line represents the bonding location with other structures.

[0363] Synthesis of Resin Particles

[0364] 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.

[0365] In addition, known methods such as microcapsule synthesis and microgel (cross-linked resin particles) synthesis can be used in the synthesis of resin particles.

[0366] <<Average particle size>>

[0367] 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.

[0368] 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.

[0369] In addition, unless otherwise specified, the average particle size of the particles in this invention is the volume average particle size.

[0370] The particles (preferably resin particles) may be of one type or two or more types.

[0371] 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.

[0372] [Other ingredients]

[0373] The image recording layer in this invention may contain other components besides those already described.

[0374] Other components include adhesive polymers, color developers, color-developing compounds, chain transfer agents, low-molecular-weight hydrophilic compounds, sensitizers, and other additives.

[0375] 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.

[0376] 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.

[0377] -Adhesive Polymer-

[0378] Depending on the requirements, the image recording layer may contain an adhesive polymer.

[0379] Here, adhesive polymers refer to polymers other than resin particles, that is, polymers that are not in particle shape.

[0380] Furthermore, this excludes ammonium salt polymers in adhesive polymers, sensitizers, and polymers used as surfactants.

[0381] 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.).

[0382] 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.

[0383] 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).

[0384] When the main chain has poly(epoxy) sites, polyurethane resin is preferred.

[0385] 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.

[0386] Furthermore, as another preferred example of an adhesive polymer, a polymeric compound having a polyfunctional thiol with 6 or more functions and less than 10 functions as a core, and having a polymer chain bonded to the core via a thioether bond, and the polymer chain having polymerizable groups (hereinafter also referred to as a star polymeric compound).

[0387] As a star-shaped polymer compound, for example, the compound described in Japanese Patent Application Publication No. 2012-148555 can be preferred.

[0388] 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.

[0389] As polymerizable groups, olefinic unsaturated groups such as (meth)acrylate, vinyl, allyl, and vinylphenyl (styrene) are preferred, as are epoxy groups. 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 utilized.

[0390] 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.

[0391] 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.

[0392] From the viewpoint of machine developability, the image recording layer preferably comprises polyvinyl acetal. Examples of polyvinyl acetal include, for instance, polyvinyl butyral.

[0393] Adhesive polymers can be used alone or in combination with two or more.

[0394] 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.

[0395] -Color developer-

[0396] The image recording layer of the present invention preferably further comprises a color developer, more preferably an acid color developer. Furthermore, as the color developer, it is preferable to include a colorless compound.

[0397] 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, sulfolactones, spiropyrans, esters, or amides are particularly preferred, and these partial skeletons rapidly undergo ring-opening or cleavage upon contact with an electron-accepting compound.

[0398] Examples of such acid colorimetric reagents include the compounds described in paragraphs 0184 to 0191 of Japanese Patent Application Publication No. 2019-18412.

[0399] From a visual recognition point of view, the colorimetric agent used in this invention is preferably at least one compound selected from spiropyran compounds, spiroxazine compounds, spironolactone compounds, and spironolactam compounds.

[0400] 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.

[0401] Furthermore, from the viewpoint of visual recognizability and the visual recognizability of the exposed part, the aforementioned acid developer is preferably a colorless pigment.

[0402] 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 to have a spironolactone ring structure.

[0403] 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 fluorane parent structure.

[0404] Furthermore, from the viewpoint of visual recognizability and the visual recognizability of the exposed part, the colorless pigment having a phthaloyl structure or a fluorane parent 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).

[0405] [Chemical Formula 22]

[0406]

[0407] 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, an aryl group, or a heteroaryl group.

[0408] From the viewpoint of color development and visual recognizability of the exposed portion, the electron-donating group in the ERG of formulas (Le-1) to (Le-3) is preferably amino, alkylamino, arylamino, heteroarylamino, dialkylamino, monoalkyl monoarylamino, monoalkyl monoheteroarylamino, diarylamino, diheteroarylamino, monoaryl monoheteroarylamino, alkoxy, aryloxy, heteroaryloxy, or alkyl. More preferably, it is amino, alkylamino, arylamino, heteroarylamino, dialkylamino, monoalkyl monoarylamino, monoalkyl monoheteroarylamino, diarylamino, diheteroarylamino, monoaryl monoheteroarylamino, alkoxy, or aryloxy. Even more preferably, it is monoalkyl monoarylamino, diarylamino, diheteroarylamino, or monoaryl monoheteroarylamino, and especially preferably monoalkyl monoarylamino.

[0409] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the electron-donating group in the aforementioned ERG is preferably a disubstituted amino group having an aryl group with a substituent at at least one ortho position or a heteroaryl group with a substituent at at least one ortho position. More preferably, it is a disubstituted amino group having a phenyl group having a substituent at at least one ortho position and an electron-donating group at the para position. Even more preferably, it is an amino group having a phenyl group having a substituent at at least one ortho position and an electron-donating group at the para position and an aryl group or a heteroaryl group with an electron-donating group. Particularly preferred is an amino group having a phenyl group having a substituent at at least one ortho position and an electron-donating group at the para position and an aryl group or a heteroaryl group with an electron-donating group.

[0410] In addition, in this invention, the adjacent position in aryl or heteroaryl groups other than phenyl refers to the bonding position (e.g., position 2, etc.) adjacent to the aforementioned position 1 when the bonding position of aryl or heteroaryl group with other structures is set to position 1.

[0411] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the electron-donating group of the aforementioned aryl or heteroaryl group is preferably amino, alkylamino, arylamino, heteroarylamino, dialkylamino, monoalkylmonoarylamino, monoalkylmonoheteroarylamino, diarylamino, diheteroarylamino, monoarylmonoheteroarylamino, alkoxy, aryloxy, heteroaryloxy, or alkyl, more preferably alkoxy, aryloxy, heteroaryloxy, or alkyl, and especially preferably alkoxy.

[0412] From the viewpoint of color development and visual recognizability of the exposed part, X1 to X4 in formulas (Le-1) to (Le-3) are each preferably hydrogen atoms or chlorine atoms, and more preferably hydrogen atoms.

[0413] From the perspective of color development and the visual recognizability of the exposed part, X5 to X in formula (Le-2) or formula (Le-3) 10 The atom is preferably hydrogen, halogen, alkyl, aryl, amino, alkylamino, arylamino, heteroarylamino, dialkylamino, monoalkylmonoarylamino, monoalkylmonoheteroarylamino, diarylamino, diheteroarylamino, monoarylmonoheteroarylamino, hydroxyl, alkoxy, aryloxy, heteroaryloxy, acyl, alkoxycarbonyl, aryloxycarbonyl, heteroaryloxycarbonyl, or cyano, more preferably hydrogen, halogen, alkyl, aryl, alkoxy, or aryloxy, even more preferably hydrogen, halogen, alkyl, or aryl, and especially preferably hydrogen.

[0414] From the viewpoint of color development and visual recognizability of the exposed part, Y1 and Y2 in formulas (Le-1) to (Le-3) are preferably at least one of them as C, and more preferably both Y1 and Y2 are C.

[0415] From the viewpoint of color development and visual recognizability of the exposed part, Ra1 in formulas (Le-1) to (Le-3) is preferably alkyl or alkoxy, more preferably alkoxy, and especially preferably methoxy.

[0416] From the viewpoint of color development and visual recognizability of the exposed part, Rb1 to Rb4 in formulas (Le-1) to (Le-3) are each preferably hydrogen atoms or alkyl groups, more preferably alkyl groups, and especially preferably methyl groups.

[0417] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the colorless pigment having the above-mentioned phthaloyl structure or fluorane parent 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).

[0418] [Chemical Formula 23]

[0419]

[0420] 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, an aryl group, or a heteroaryl group.

[0421] 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.

[0422] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the aforementioned colorless pigment having a phthaloyl structure or a fluorane parent 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).

[0423] [Chemical Formula 24]

[0424]

[0425] 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, 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, aryl or heteroaryl groups, and Rc1 and Rc2 independently represent aryl or heteroaryl groups.

[0426] 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.

[0427] From the viewpoint of color development and visual recognizability of the exposed part, Ra1 to Ra4 in formula (Le-7) or formula (Le-9) are each preferably alkyl or alkoxy, more preferably alkoxy, and especially preferably methoxy.

[0428] From the viewpoint of color development and visual recognizability of the exposed part, Rb1 to Rb4 in formulas (Le-7) to (Le-9) are each preferably aryl groups substituted with hydrogen atoms, alkyl groups or alkoxy groups, more preferably alkyl groups, and especially preferably methyl groups.

[0429] From the viewpoint of color development and visual recognizability of the exposed part, Rc1 and Rc2 in formula (Le-8) are preferably phenyl or alkylphenyl, and more preferably phenyl.

[0430] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, Rc1 and Rc2 in formula (Le-8) are each preferably aryl groups having a substituent at at least one ortho position or heteroaryl groups having a substituent at at least one ortho position, more preferably aryl groups having a substituent at at least one ortho position, even more preferably phenyl groups having a substituent at at least one ortho position, and particularly preferably phenyl groups having a substituent at at least one ortho position and an electron-donating group at the para position. Examples of the substituents in Rc1 and Rc2 described later can be cited.

[0431] Furthermore, in formula (Le-8), from the viewpoint of color development and visual recognizability of the exposed part, it is preferable that X1 to X4 are hydrogen atoms and Y1 and Y2 are C atoms.

[0432] Furthermore, in formula (Le-8), from the viewpoint of color development and visual recognizability of the exposed portion, Rb1 and Rb2 are each preferably aryl groups substituted with alkyl or alkoxy groups.

[0433] Furthermore, in formula (Le-8), from the viewpoint of color development and visual recognizability of the exposed portion, Rb1 and Rb2 are each preferably aryl or heteroaryl, more preferably aryl, even more preferably aryl having an electron-donating group, and especially preferably phenyl having an electron-donating group at the para position.

[0434] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, the electron-donating groups in Rb1, Rb2, Rc1, and Rc2 are preferably amino, alkylamino, arylamino, heteroarylamino, dialkylamino, monoalkylmonoarylamino, monoalkylmonoheteroarylamino, diarylamino, diheteroarylamino, monoarylmonoheteroarylamino, alkoxy, aryloxy, heteroaryloxy, or alkyl, more preferably alkoxy, aryloxy, heteroaryloxy, or alkyl, and especially preferably alkoxy.

[0435] Furthermore, from the viewpoint of color development and visual recognizability of the exposed portion, it is preferable to use a compound represented by the following formula (Le-10) as the acid color developer.

[0436] [Chemical Formula 25]

[0437]

[0438] In formula (Le-10), Ar1 independently represents aryl or heteroaryl, and Ar2 independently represents aryl with substituents at at least one ortho position, or heteroaryl with substituents at at least one ortho position.

[0439] Ar1 in formula (Le-10) has the same meaning as Rb1 and Rb2 in formulas (Le-7) to (Le-9), and the preferred method is also the same.

[0440] Ar2 in equation (Le-10) has the same meaning as Rc1 and Rc2 in equations (Le-7) to (Le-9), and the preferred method is also the same.

[0441] The alkyl groups in formulas (Le-1) to (Le-9) can be straight chains, branched chains, or ring structures.

[0442] 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.

[0443] The number of carbon atoms in the aryl group in formulas (Le-1) to (Le-10) is preferably 6 to 20, more preferably 6 to 10, and especially preferably 6 to 8.

[0444] As aryl groups in formulas (Le-1) to (Le-10), examples include phenyl, naphthyl, anthracene, and phenanthrene groups, which may have substituents.

[0445] As for the heteroaryl groups in formulas (Le-1) to (Le-10), examples include those that can have substituents, such as furanyl, pyridyl, pyrimidinyl, pyrazolyl, and phenylthioyl.

[0446] Furthermore, the monovalent organic groups, alkyl, aryl, heteroaryl, dialkylaniline, alkylamino, alkoxy, and other groups in formulas (Le-1) to (Le-10) can have substituents. Examples of substituents include alkyl, aryl, heteroaryl, halogen atoms, amino, alkylamino, arylamino, heteroarylamino, dialkylamino, monoalkylmonoarylamino, monoalkylmonoheteroarylamino, diarylamino, diheteroarylamino, monoarylmonoheteroarylamino, hydroxyl, alkoxy, aryloxy, heteroaryloxy, acyl, alkoxycarbonyl, aryloxycarbonyl, heteroaryloxycarbonyl, cyano, etc. Moreover, these substituents can be further replaced by these substituents.

[0447] The following compounds are examples of colorless pigments having a phthalide structure or a fluorane parent structure that are preferred for use.

[0448] [Chemical Formula 26]

[0449]

[0450] [Chemical Formula 27]

[0451]

[0452] [Chemical Formula 28]

[0453]

[0454] [Chemical Formula 29]

[0455]

[0456] [Chemical Formula 30]

[0457]

[0458] [Chemical Formula 31]

[0459]

[0460] [Chemical Formula 32]

[0461]

[0462] [Chemical Formula 33]

[0463]

[0464] 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 CO., Ltd.). (manufactured by LTD.), ODB, ODB-2, ODB-4, ODB-250, ODB-BlackXV, Blue-63, Blue-502, GN-169, GN-2, Green-118, Red-40, Red-8 (all manufactured by YAMAMOTO CHEMICALS INC.), crystal violet lactone (manufactured by Tokyo Chemical Industry Co., Ltd.), etc. Among these commercially available products, ETAC, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, H-3035, ATP, H-1046, H-2114, GREEN-DCF, Blue-63, GN-169, and crystal violet lactone form films with good visible light absorption, and are therefore preferred.

[0465] From the viewpoint of visual recognition and the visual recognition of the exposed part, the following compounds can be cited as preferred colorless pigments.

[0466] [Chemical Formula 34]

[0467]

[0468] These color developers can be used alone or in combination with two or more components.

[0469] The content of the developer is preferably 0.5% to 10% by mass relative to the total mass of the image recording layer, more preferably 1% to 5% by mass.

[0470] -Color-producing compounds-

[0471] In the on-machine developing type lithographic printing plate original involved in the present invention, the image recording layer preferably contains a color-developing compound capable of reacting with the decomposition products generated by exposure of the image recording layer.

[0472] In this invention, "color reaction" refers to the chemical reaction that occurs along with the color development or color change phenomenon.

[0473] There are no particular limitations on the decomposition products generated by the exposure of the image recording layer described above. However, from the viewpoint of visual recognizability of the exposed part, it is preferable to be a decomposition product generated by the exposure of a polymerization initiator or a decomposition product generated by the exposure of an infrared absorber. More preferably, it is a decomposition product generated by the exposure of a polymerization initiator. In particular, it is preferable to be a decomposition product generated by the exposure of an electron-donating polymerization initiator.

[0474] Furthermore, the decomposition products generated by exposure of the aforementioned image recording layer not only include the decomposition products generated by exposure of the aforementioned image recording layer, but also include compounds generated by further decomposition or modification of the aforementioned decomposition products.

[0475] Furthermore, from the viewpoint of visual recognizability of the exposed part, the aforementioned color development reaction is preferably a complexation formation reaction, and more preferably a boron complexation formation reaction.

[0476] The following illustrates an example of the aforementioned colorimetric reaction. The following shows the colorimetric reaction when curcumin is used as the colorimetric compound, and sodium tetraphenylborate decomposes to produce boric acid as a decomposition product generated by exposure to the image recording layer. Due to keto-enol tautomerism, curcumin produces an enol form as an equilibrium. The enol form reacts with boric acid to produce the following boron complex, resulting in a colorimetric reaction from curcumin (yellow) to the following boron complex (red).

[0477] Furthermore, examples of hydrolysis to boric acid are shown below, but for example, diphenyl monohydroxyboron, monophenyl dihydroxyboron, etc. can form complexes with curcumin, or triphenylboron can coordinate with enol curcumin as a zero-valent ligand to form complexes.

[0478] [Chemical Formula 35]

[0479]

[0480] From the viewpoint of visual recognizability and tone reproduction of the exposed part, the preferred colorimetric compound is a compound having one or more ketone structures, more preferably a compound having one or more 1,3-diketone structures, β-hydroxyketone structures or β-aminoketone structures, and even more preferably a compound having one or more 1,3-diketone structures or β-hydroxyketone structures, and especially preferably a compound having one or more 1,3-diketone structures.

[0481] Furthermore, as examples of the aforementioned colorimetric compounds, compounds having one or more 1-hydroxy-3-amino or 1-hydroxy-3-imino structures can also be cited.

[0482] Furthermore, from the viewpoint of visual recognizability and tone reproduction of the exposed portion, the aforementioned colorimetric compound is preferably a compound having an aromatic ring structure, more preferably a compound having two or more aromatic ring structures, even more preferably a compound having two to four aromatic ring structures, and especially preferably a compound having two aromatic ring structures.

[0483] From the viewpoint of visual recognizability and tone reproduction of the exposed portion, at least one selected from benzene ring structure and naphthalene ring structure is preferred as the aforementioned aromatic ring structure, and benzene ring structure is more preferred.

[0484] Furthermore, the aforementioned colorimetric compounds can be either salts or hydrates.

[0485] Furthermore, regarding the aforementioned colorimetric compound, when it reacts with the decomposition products generated by exposure through the aforementioned image recording layer to form a complex, the complex can be a monodentate ligand or a polydentate ligand. However, from the viewpoints of complex formation, visual recognizability of the exposed portion, and tone reproduction, a polydentate ligand is preferred, a bidentate to hexadentate ligand is more preferred, a bidentate to tetradentate ligand is even more preferred, a bidentate or tridentate ligand is particularly preferred, and a bidentate ligand is most preferred.

[0486] In the on-machine developing type lithographic printing plate original involved in the present invention, from the viewpoint of visual recognizability and tone reproduction of the exposure section, the aforementioned color developing compound preferably includes a compound represented by the following formula 1C or formula 2C, and more preferably includes a compound represented by the following formula 1C.

[0487] Furthermore, in the on-machine developing type lithographic printing plate original according to the present invention, preferably after exposure, the compound represented by Formula 1C or Formula 2C reacts with the decomposition products generated by the exposure of the image recording layer to form a complex having the compound represented by Formula 1C or Formula 2C as a zero-valent ligand or having an anion obtained by removing one hydrogen atom from the compound represented by Formula 1C or Formula 2C as a monovalent ligand. More preferably, the compound represented by Formula 1C or Formula 2C reacts with the decomposition products generated by the exposure of the image recording layer to form a complex having an anion obtained by removing one hydrogen atom from the compound represented by Formula 1C or Formula 2C as a monovalent ligand.

[0488] [Chemical Formula 36]

[0489]

[0490] In Equations 1C and 2C, R 1C ~R 4C Each independently represents a monovalent organic group, L 1C and L 2C Each of the following independently represents a divalent organic group, A C Indicates OH or NR 5C R 6C R 5C and R 6C Each can be represented independently as a hydrogen atom or a monovalent organic group, with the dashed part indicating a part that may be a double bond.

[0491] In Equation 1C, R 1C L 1C and R 2C Two or more of them can bond together to form a ring structure.

[0492] In equation 2C, R 3C L 2C R 4C R 5C and R 6C Two or more of them can bond together to form a ring structure.

[0493] From the perspective of the visual recognizability and tone reproduction of the exposure section, R in Equation 1C 1C and R 2C Each and every one of them is preferably a monovalent organic group having an aromatic ring, more preferably an aryl or an alkenyl group having an aryl, and especially preferably 2-arylvinyl.

[0494] Furthermore, the aforementioned aryl group may have substituents. From the viewpoint of visual recognizability and tone reproduction of the exposed portion, it is preferable to have an aryl group having one or more substituents selected from hydroxyl and alkoxy groups, more preferably a phenyl group having one or more substituents selected from hydroxyl and alkoxy groups, and especially preferably a phenyl group having hydroxyl and alkoxy groups as substituents.

[0495] Moreover, R in Equation 1C 1C and R 2C The number of carbon atoms is preferably 6 to 50, more preferably 6 to 20, and especially preferably 8 to 20.

[0496] Furthermore, R in Equation 1C 1C and R 2C Preferably, they are the same group.

[0497] From the perspective of the visual recognizability and tone reproduction of the exposure section, L in Equation 1C 1CPreferably, it is an alkylene group having an alkylene or acyloxy group, more preferably a methylene or acyloxymethylene group.

[0498] Furthermore, from the viewpoint of visual recognizability of the exposed portion, the aforementioned acyloxy group is preferably an acyloxy group with 1 to 10 carbon atoms, more preferably an acyloxy group with 1 to 4 carbon atoms, and especially preferably an acetoxy group.

[0499] From the perspective of the visual recognizability and tone reproduction of the exposure section, R in Equation 2C 3C Preferably, it is a monovalent organic group having an aromatic ring, more preferably an aryl group or an alkenyl group having an aryl group.

[0500] In Equation 2C, from the viewpoint of visual recognizability and tone reproduction of the exposed area, L is preferred. 2C With R 4C Bonding to form an aromatic ring, more preferably L 2C With R 4C They bond together to form a benzene ring.

[0501] Furthermore, R in Equation 2C 3C and R 4C The number of carbon atoms in each is preferably 6 to 50, more preferably 6 to 30, and especially preferably 6 to 20.

[0502] Regarding L in equation 2C 2C In relation to R 4C In the absence of bonding, from the viewpoint of visual recognizability and tone reproduction of the exposed portion, it is preferable to have an alkylene or acyloxy group, more preferably a methylene or acyloxymethylene group.

[0503] Furthermore, from the viewpoint of visual recognizability of the exposed portion, the aforementioned acyloxy group is preferably an acyloxy group with 1 to 10 carbon atoms, more preferably an acyloxy group with 1 to 4 carbon atoms, and especially preferably an acetoxy group.

[0504] Furthermore, L in Equation 2C 2C Preferred and R 4C They bond together to form ring elements of an aromatic ring structure.

[0505] From the viewpoint of visual recognizability and tone reproduction of the exposed part, the compound represented by Formula 2C is preferably a compound having a 1-hydroxyanthraquinone structure or a 1-aminoanthraquinone structure, and more preferably a compound having a 1-hydroxyanthraquinone structure.

[0506] From the perspective of the visual recognizability and tone reproduction of the exposure section, A in Equation 2C C Preferably OH or NHR 6C More preferably, it is OH.

[0507] NR of Equation 2C5C R 6C R in 5C Preferably, it is a hydrogen atom, alkyl or aryl, more preferably a hydrogen atom or alkyl, and especially preferably a hydrogen atom.

[0508] NR of Equation 2C 5C R 6C R in 6C Preferably, it is a hydrogen atom, an alkyl group or anthraquinone group, more preferably anthraquinone group, and especially preferably 1-anthraquinone group.

[0509] Specifically, examples of the aforementioned colorimetric compounds include, for instance, curcumin (C-1 described later in the examples), demethoxycurcumin (C-2 described later in the examples), alizarin (C-3 described later in the examples), iminodiathraquinone (C-4 described later in the examples), carmine acid (C-5 described later in the examples), azomethyl base H (C-6 described later in the examples), 1,3-bis(4-methoxyphenyl)-1,3-propanedione (C-7 described later in the examples), 4-methoxychalcone (C-8 described later in the examples), 1,3-bis(4-dimethylaminophenyl)-1,3-propanedione (C-9 described later in the examples), and acetoxycurcumin (C-10 described later in the examples).

[0510] The aforementioned colorimetric compounds may be used in isolation or in combination with two or more compounds.

[0511] Furthermore, the compound represented by Formula 1C or Formula 2C above may be used in only one form or in two or more forms simultaneously.

[0512] Moreover, the aforementioned complexes can form only one type or more types.

[0513] From the viewpoint of visual recognizability and tone reproduction of the exposure section, the content of the color-developing compound is preferably 0.001% to 5% by mass, more preferably 0.01% to 3% by mass, even more preferably 0.05% to 2.5% by mass, and particularly preferably 0.05% to 1.0% by mass, relative to the total mass of the image recording layer.

[0514] The content M of the above-mentioned colorimetric compound (preferably a compound represented by formula 1C or formula 2C) in the image recording layer is... C The content M of the polymerization initiator, as described later. I The preferred molar ratio is M C / M I =0.001~1, more preferably M C / M I =0.01~0.8, especially preferred M C / MI =0.05~0.5.

[0515] Furthermore, the content M of the aforementioned colorimetric compound (preferably a compound represented by formula 1C or formula 2C) in the image recording layer is... C The content M of the electron-donating polymerization initiator, as described later. DI The preferred molar ratio is M C / M DI =0.001~1.5, more preferably M C / M DI =0.01~1, especially preferred M C / M DI =0.05~0.8.

[0516] [Formation of image recording layer]

[0517] 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, applying the coating liquid onto a support using a known method such as bar coating, and then drying it. 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.

[0518] 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. Solvents can be used alone or in combination of two or more. The concentration of solid components in the coating solution is preferably 1% to 50% by mass.

[0519] 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 .

[0520] 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.

[0521] 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).

[0522] <Outer Coating>

[0523] The on-machine developing type lithographic printing plate master involved in this invention has a support, an image recording layer and an outer coating layer in sequence. The outer coating layer does not contain inorganic compounds, or the content of inorganic compounds is more than 0% by mass and less than 1% by mass relative to the total mass of the outer coating layer.

[0524] From the viewpoint of machine developability and dampening solution turbidity suppression, the above-mentioned outer coating preferably does not contain inorganic compounds, or the content of inorganic compounds relative to the total mass of the above-mentioned outer coating is more than 0% by mass and less than 0.5% by mass, and more preferably does not contain inorganic compounds.

[0525] Furthermore, from a visual recognition point of view, the aforementioned outer coating preferably contains a color-changing compound.

[0526] Furthermore, the aforementioned outer coating is the outer coating on the image recording layer side of the support in the machine-developed lithographic printing plate original.

[0527] In addition to inhibiting the image formation reaction by blocking oxygen, the aforementioned outer coating can also prevent scratches in the image recording layer and prevent ablation during high-intensity laser exposure.

[0528] -Color-changing compounds-

[0529] Furthermore, the aforementioned outer coating preferably contains a color-changing compound.

[0530] In addition to the color-changing compound, the outer coating 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.

[0531] 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.

[0532] 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.

[0533] 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.

[0534] As a color-changing compound, it is preferable to include a compound that develops color upon exposure to infrared light.

[0535] 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.

[0536] More specifically, the color-changing compound in this invention is preferably a compound that decomposes upon infrared exposure (more preferably through thermal or electron transfer or both caused by infrared exposure), and whose absorption in the visible light region is increased or shortened in wavelength compared to before infrared exposure, and which has absorption in the visible light region.

[0537] Here, "decomposition by electron transfer" refers to the process by which electrons excited from the HOMO (highest occupied orbital) of the color-changing compound to the LUMO (lowest unoccupied molecular orbital) are transferred within the molecule to electron-accepting groups (groups with potential close to the LUMO), resulting in decomposition.

[0538] Furthermore, from the viewpoint of improving the visual recognizability of the exposed part, the color-changing compound is preferably anthocyanin.

[0539] The following describes a decomposing compound as an example of a color-changing compound.

[0540] Regarding decomposable compounds, any compound that absorbs at least a portion of light in the infrared wavelength region (wavelength region of 750 nm to 1 mm, preferably the wavelength region of 750 nm to 1,400 nm) and decomposes it is acceptable, but compounds with a large absorption wavelength in the wavelength region of 750 nm to 1,400 nm are preferred.

[0541] 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.

[0542] 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.

[0543] 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.

[0544] [Chemical Formula 37]

[0545]

[0546] 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 10 It represents a hydrogen atom, alkyl group, or aryl group; Za represents a counterion that neutralizes the charge.

[0547] [Chemical Formula 38]

[0548]

[0549] In equations 2-1 to 4-1, R 20 R 30 R 41 and R42 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 above.

[0550] 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.

[0551] In Equation 1-1, R 1 It represents any one of the groups represented by formulas 2-1 to 4-1 above.

[0552] The groups represented by Formula 2-1, Formula 3-1, and Formula 4-1 will be explained below.

[0553] 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.

[0554] As by R20 The alkyl group indicated is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms.

[0555] The alkyl groups mentioned above can be straight-chain, branched, or have a cyclic structure.

[0556] 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.

[0557] As R 20 From the point of view of visual recognizability, alkyl groups are preferred.

[0558] Furthermore, from the perspective of decomposition and visual recognition, 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.

[0559] 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.

[0560] 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.

[0561] [Chemical Formula 39]

[0562]

[0563] 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.

[0564] 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.

[0565] From the perspective of decomposition and visual recognition, 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.

[0566] 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.

[0567] 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.

[0568] 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).

[0569] 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.

[0570] [Chemical Formula 40]

[0571]

[0572] In Equation 4-1, R 41 and R 42Each 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.

[0573] 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.

[0574] As R 41 From the viewpoints of decomposability and visual recognizability, alkyl groups are preferred.

[0575] As R 42 From the viewpoints of decomposability and visual recognizability, alkyl groups are preferred.

[0576] 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.

[0577] From the perspective of decomposition and visual recognition, 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.

[0578] 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.

[0579] 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.

[0580] 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.

[0581] 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.

[0582] [Chemical Formula 41]

[0583]

[0584] In Equation 1-1, L is preferably an oxygen atom or -NR. 10- Oxygen atoms are particularly preferred.

[0585] 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.

[0586] Among the alkyl groups, methyl or cyclohexyl is preferred.

[0587] 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.

[0588] 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 .

[0589] 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.

[0590] The aforementioned hydrocarbon groups can be straight-chain, branched, or have a ring structure.

[0591] Alkyl groups are particularly preferred as the aforementioned hydrocarbon groups.

[0592] 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.

[0593] The alkyl groups mentioned above can be straight-chain, branched, or have a cyclic structure.

[0594] 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-norbornyl.

[0595] Among the alkyl groups, methyl, ethyl, propyl or butyl are preferred.

[0596] The alkyl groups mentioned above may have substituents.

[0597] Examples of substituents include alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, carboxylic acid ester, sulfonyl, sulfonate, alkoxycarbonyl, aryloxycarbonyl, and groups formed by combining them.

[0598] 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.

[0599] 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.

[0600] Furthermore, in A1 + R bonded to the bonded carbon atom 12 Preferred and R 15 Or R 16 (Preferred to be R) 16 The links form a ring, with R bonded to the carbon atom bonded to A2. 14 Preferred and R 17 Or R 18 (Preferred to be R) 18 They are connected to form a ring.

[0601] In Equation 1-1, n is preferred. 13 R is 1. 16 -R a (i.e., hydrocarbon group).

[0602] Furthermore, R 16 Preferred and in A1 + R bonded to the bonded carbon atom 12 The 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.

[0603] In Equation 1-1, n is preferred. 14 R is 1. 18 -Ra (i.e., hydrocarbon group).

[0604] 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.

[0605] 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.

[0606] 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.

[0607] 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.

[0608] 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).

[0609] [Chemical Formula 42]

[0610]

[0611] In equations (a1) to (a4), R W0 Indicates an alkylene group with 2 to 6 carbon atoms, where W represents a single bond or an oxygen atom, and n W1 R represents integers from 1 to 45. W1 Alkyl groups with 1 to 12 carbon atoms or -C(=O)-R W5 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.

[0612] In equation (a1), as a result of R W0Specific 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.

[0613] n W1 Preferably 1 to 10, more preferably 1 to 5, and especially preferably 1 to 3.

[0614] 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.

[0615] 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.

[0616] 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.

[0617] [Chemical Formula 43]

[0618]

[0619] In equations (a2) to (a4), as R W2 ~R W4 Specific examples of the alkylene group include methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, n-pentylene, isopentylene, n-hexylene, isohexylene, n-octylene, n-dodecylene, etc., preferably ethylene, n-propylene, isopropylene or n-butylene, and especially preferably ethylene or n-propylene.

[0620] In equation (a3), there are two M values ​​that can be the same or different.

[0621] In formulas (a2) to (a4), examples of ononium groups represented by M include ammonium, iodonium, phosphonium, and sulfonium groups.

[0622] CO2M in formula (a2), PO3M2 in formula (a2), and SO3M in formula (a4) can all have anionic structures with M dissociation. The counter cation of the anionic structure can be A1. + It can also be R in Equation 1-1 1 -L can contain cations.

[0623] Among the groups represented by formulas (a1) to (a4), groups represented by formulas (a1), (a2), or (a4) are preferred.

[0624] 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.

[0625] In Formula 1-1, A1 and A2 independently represent oxygen, sulfur, or nitrogen atoms, with nitrogen atoms being preferred.

[0626] In Formula 1-1, A1 and A2 are preferably the same atoms.

[0627] In Equation 1-1, Za represents the counter ion that neutralizes the charge.

[0628] 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.

[0629] 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.

[0630] 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.

[0631] 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.

[0632] From the viewpoint of improving the visual recognizability of the exposed part, a compound represented by the following formulas 1-2 (i.e., anthocyanin) is more preferred as a decomposing compound.

[0633] [Chemical Formula 44]

[0634]

[0635] 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.

[0636] R in Equation 1-2 1 R in Equation 1-1 1 The meanings are the same, and the preferred selection methods are also the same.

[0637] 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.

[0638] More specifically, R 19 and R 21 Preferably hydrogen atoms or -R a .

[0639] Furthermore, R 20 and R 22 Preferably hydrogen atoms, -R a -OR b Or -CN.

[0640] As a result of R 19 ~R 22 -R indicates aPreferably alkyl or alkenyl groups.

[0641] 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.

[0642] As R 19 With R 20 Or R 21 With R 22 Examples of rings formed by linkages include benzene rings and naphthalene rings.

[0643] In Equation 1-2, R is preferred. 23 With R 24 They can be linked together to form single or multiple rings.

[0644] 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.

[0645] 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.

[0646] Examples of unsubstituted alkyl groups include those with 1 to 4 carbon atoms, with methyl being preferred.

[0647] 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.

[0648] 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.

[0649] 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.

[0650] Za represents a counterion that neutralizes the charge within a molecule.

[0651] 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.

[0652] 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.

[0653] 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.

[0654] From the viewpoint of decomposability and visual recognizability, anthocyanins, as decomposable compounds, are further preferably compounds represented by any of the following formulas 1-3 to 1-7.

[0655] 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.

[0656] [Chemical Formula 45]

[0657]

[0658] In equations 1-3 to 1-7, R 1R 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.

[0659] 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.

[0660] 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.

[0661] The following are specific examples of anthocyanins that are decomposable compounds, but the present invention is not limited to these.

[0662] [Chemical Formula 46]

[0663]

[0664] Furthermore, as a decomposable compound, anthocyanin is preferably an infrared-absorbing compound as described in International Publication No. 2019 / 219560.

[0665] Furthermore, the aforementioned color-changing compounds may contain acid color-developing agents.

[0666] 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.

[0667] Color-changing compounds can be used alone or in combination with two or more components.

[0668] As a chromogenic compound, it can be used in combination with the decomposition compounds already described and the acid-producing agents described later.

[0669] From a visual recognition point of view, the content of the color-changing compound in the outer coating 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 outer coating.

[0670] From a visual recognition point of view, the content M of the aforementioned color-changing compound in the aforementioned outer coating 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.

[0671] -Hydrophilic polymer-

[0672] From the viewpoint of developability (more preferably machine developability), the above-mentioned outer coating preferably contains a hydrophilic polymer, and more preferably a water-soluble polymer.

[0673] 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.

[0674] Examples of water-soluble polymers used in the outer coating include polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, cellulose derivatives, polyethylene glycol, and poly(meth)acrylonitrile.

[0675] 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.

[0676] Among these, from the viewpoint of machine developability, cellulose derivatives are preferred as hydrophilic polymers, and hydroxyalkyl cellulose is more preferred.

[0677] 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.

[0678] 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%.

[0679] The above degree of saponification can be determined according to the method described in JIS K 6726:1994.

[0680] Polyvinylpyrrolidone is a preferred example of the aforementioned water-soluble polymer.

[0681] As a water-soluble polymer, polyvinyl alcohol and polyvinylpyrrolidone are also preferably used in combination.

[0682] Water-soluble polymers can be used alone or in combination of two or more.

[0683] When the outer coating contains a water-soluble polymer, the content of the water-soluble polymer relative to the total mass of the outer coating is preferably 1% to 99% by mass, more preferably 3% to 97% by mass, and even more preferably 5% to 95% by mass.

[0684] -Other ingredients-

[0685] In addition to the color-changing compounds and water-soluble polymers already described, the outer coating may also contain other components such as hydrophobic polymers, sensitizers, acid-producing agents, and infrared absorbers.

[0686] The other ingredients are described below.

[0687] <<Hydrophobic Polymers>>

[0688] The aforementioned outer coating preferably comprises a hydrophobic polymer.

[0689] Hydrophobic polymers are polymers that dissolve less than 1g or are insoluble in 100g of pure water at 70°C.

[0690] Examples of hydrophobic polymers include, for example, polyethylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, alkyl poly(meth)acrylates (e.g., poly(meth)acrylate, poly(ethyl)acrylate, poly(butyl)acrylate, etc.), and copolymers formed by combining the raw material monomers of these polymers.

[0691] Furthermore, as a hydrophobic polymer, polyvinylidene chloride resin is preferred.

[0692] Furthermore, as a hydrophobic polymer, it is preferable to include a styrene-acrylic acid copolymer.

[0693] Furthermore, from the viewpoint of machine developability, hydrophobic polymers are preferably hydrophobic polymer particles.

[0694] Hydrophobic polymers can be used alone or in combination of two or more.

[0695] When the outer coating 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 outer coating.

[0696] <<Acid-producing agent>>

[0697] When the above-mentioned outer coating uses an acid color developer as a color-changing compound, it preferably contains an acid-generating agent.

[0698] 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.

[0699] 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.

[0700] Specifically, from the viewpoint of sensitivity and stability, onium salt compounds are preferred as acid-producing agents.

[0701] 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.

[0702] Among them, triarylsulfonium or diaryliodonium sulfonates, carboxylates, and BPh4 are preferred. - BF4 - PF6 - ClO4 - etc. Here, Ph represents phenyl.

[0703] Acid-producing agents can be used alone or in combination of two or more.

[0704] When the outer coating contains an acid-generating agent, the content of the acid-generating agent is preferably 0.5% to 30% by mass, more preferably 1% to 20% by mass, relative to the total mass of the outer coating.

[0705] In addition to the components already described, the outer coating may also contain known additives such as sensitizers, inorganic layered compounds, and surfactants.

[0706] The outer coating is formed by applying and drying using known methods.

[0707] The preferred coating weight (solid content) for the outer coating is 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 .

[0708] The thickness of the outer coating is preferably 0.1 μm to 5.0 μm, more preferably 0.3 μm to 4.0 μm.

[0709] The thickness of the outer coating 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.

[0710] The outer coating may contain known additives such as plasticizers for imparting flexibility, surfactants for improving coatability, and inorganic particles for controlling surface lubricity.

[0711] <Support Body>

[0712] The original lithographic printing plate involved in this invention has a support.

[0713] As a support, it can be appropriately selected from known supports for lithographic printing plates.

[0714] As a support, a support having a hydrophilic surface is preferred (hereinafter also referred to as "hydrophilic support").

[0715] 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.

[0716] 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.

[0717] 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.

[0718] Figure 1 This is a schematic cross-sectional view of one embodiment of the aluminum support 12a.

[0719] 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.

[0720] -Anodized film-

[0721] The preferred embodiment of the anodic oxide film 20a will be described below.

[0722] 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).

[0723] 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 print durability, 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.

[0724] 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.

[0725] The average diameter of the micropore 22a is as follows: the surface of the anodic oxide film 20a was observed using a field emission scanning electron microscope (FE-SEM) with a magnification of 150,000x in N=4 images. The diameter of 50 micropores existing in the range of 400nm×600nm was measured in the four images obtained and the average value was obtained.

[0726] 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.

[0727] The shape of the micropore 22a is not particularly limited, in Figure 1 The core is roughly straight tubular (roughly cylindrical), but it can also be conical, with the diameter decreasing towards the depth direction (thickness direction). Furthermore, the shape of the bottom of the micropore 22a is not particularly limited; it can be curved (convex) or planar.

[0728] In the support, 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 communicates with the bottom of the large-diameter pore portion and extends from the communication position to a certain depth.

[0729] 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.

[0730] 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 2 The 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.

[0731] -Manufacturing method of support body-

[0732] As a method for manufacturing the support used in this invention, for example, a manufacturing method that sequentially performs the following steps is preferred.

[0733] • Roughening process: The process of roughening the aluminum plate.

[0734] • Anodizing process: The process of anodizing roughened aluminum plates.

[0735] • 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.

[0736] The steps for each process are described in detail below.

[0737] <<Roughening Process>>

[0738] 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.

[0739] <<Anodizing Process>>

[0740] 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.

[0741] 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.

[0742] The conditions for anodizing can be appropriately set according to the electrolyte used, but examples include a electrolyte temperature of 5°C to 70°C (preferably 10°C to 60°C) and a current density of 0.5 A / dm³. 2 ~60A / dm 2 (Preferred 1A / dm) 2 ~60A / dm 2 The voltage is 1V to 100V (preferably 5V to 50V), the electrolysis time is 1 second to 100 seconds (preferably 5 seconds to 60 seconds), and the film weight is 0.1g / m³. 2 ~5g / m 2 (Preferred value: 0.2g / m) 2 ~3g / m 2 ).

[0743] <<Hole Enlargement Treatment>>

[0744] 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).

[0745] 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.

[0746] 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.

[0747] <Undercoat>

[0748] 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.

[0749] 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.

[0750] 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.

[0751] 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.

[0752] 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.

[0753] 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.

[0754] 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.

[0755] 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.

[0756] 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.

[0757] -Hydrophilic compounds-

[0758] From a developmental point of view, the base coating preferably contains a hydrophilic compound.

[0759] There are no particular restrictions on the use of hydrophilic compounds; any known hydrophilic compounds used in the base coat can be used.

[0760] 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.

[0761] Furthermore, as hydrophilic compounds, compounds having an amino group or a functional group with polymerization inhibition ability and a group that interacts with the surface of the support are preferred (e.g., 1,4-diazabicyclo[2.2.2]octane (DABCO), 2,3,5,6-tetrahydroxy-p-benzoquinone, chloroquinone, sulfophthalic acid, ethylenediaminetetraacetic acid (EDTA) or its salts, hydroxyethylethylenediaminetriacetic acid or its salts, dihydroxyethylethylenediaminediacetic acid or its salts, hydroxyethyliminodiacetic acid, etc. or their salts).

[0762] From the viewpoint of scratch stain inhibition, hydrophilic compounds preferably contain hydroxycarboxylic acids or their salts.

[0763] 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.

[0764] As a layer on the aforementioned aluminum support, and as a layer in contact with the aforementioned aluminum support, a base coating or an image recording layer is preferably provided. Furthermore, a hydrophilic compound, preferably a hydroxycarboxylic acid or its salt, may be contained in layers other than the layer in contact with the aforementioned aluminum support, such as an outer coating or an image recording layer.

[0765] 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.

[0766] 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.

[0767] 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.

[0768] Hydroxycarboxylic acids are a general term for organic compounds that have one or more carboxyl groups and one or more hydroxy groups in one molecule. They are also called hydroxy acids, oxyacids, hydroxycarboxylic acids, and alcohols (refer to Iwanami Rika Dictionary, 5th edition, Iwanami Shoten, 1998).

[0769] The above-mentioned hydroxycarboxylic acid or its salt is preferably represented by the following formula (HC).

[0770] R HC (OH) mhc (COOM) HC ) nhc Formula (HC)

[0771] In formula (HC), R HC M represents an organic group with the valence of mhc+nhc. HC Each of these can independently represent a hydrogen atom, an alkali metal, or onnnage. `mhc` and `nhc` can independently represent integers greater than 1. When n is greater than 2, M... HC They can be the same, or they can be different.

[0772] 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.

[0773] Examples of hydrocarbon groups include those with an MHC+NHC valence derived from aliphatic hydrocarbons, such as alkylene, alkane triyl, alkane tetrayl, alkane pentayl, alkenylene, alkene triyl, alkene tetrayl, alkene pentayl, alkynylene, alkyne triyl, alkyne tetrayl, alkyne pentayl, etc.; and those with an MHC+NHC valence derived from aromatic hydrocarbons, such as arylene, aromatic triyl, aromatic tetrayl, aromatic pentayl, etc. Examples of substituents include alkyl, alkenyl, alkynyl, aralkyl, aryl, etc. Specific examples of substituents include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 1-methylbutyl, isohexyl, 2-ethylhexyl, 2-methylhexyl, cyclohexyl, cyclopentyl, 2-norbornyl, methoxymethyl, methoxyethoxyethyl, allyloxymethyl, phenoxymethyl, acetoxymethyl, 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 hydrogen, carbon, oxygen, nitrogen, sulfur, and halogen atoms, and its number 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.

[0774] 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.

[0775] Furthermore, from the perspective of scratch stain inhibition, M HC Preferably, it is an alkali metal or onium, more preferably an alkali metal.

[0776] The total number of MHC and NHC is preferably 3 or more, more preferably 3 to 8, and even more preferably 4 to 6.

[0777] 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.

[0778] Specifically, examples of hydroxycarboxylic acids or salts of the aforementioned hydroxycarboxylic acids include gluconic acid, glycolic acid, lactic acid, malonic acid, hydroxybutyric acid (2-hydroxybutyric acid, 3-hydroxybutyric acid, γ-hydroxybutyric acid, etc.), malic acid, tartaric acid, citric acid, isocitrate, leucine, mevalonic acid, pantothenic acid, ricinoleic acid, trans-ricinoleic acid, cerebroside, quinic acid, shikimic acid, and monohydroxybenzoic acid derivatives (salicylic acid, lignoceric acid (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.

[0779] 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.

[0780] Furthermore, gluconic acid or shikimic acid is preferred as a compound having one carboxyl group and two or more hydroxyl groups.

[0781] Citric acid or malic acid is preferred as a compound having two or more carboxyl groups and one hydroxyl group.

[0782] Tartaric acid is preferred as a compound having two or more carboxyl groups and hydroxyl groups respectively.

[0783] Of these, gluconic acid is particularly preferred as the hydroxycarboxylic acid mentioned above.

[0784] Hydrophilic compounds can be used alone or in combination with two or more.

[0785] When the base coating contains a hydrophilic compound, preferably a hydroxycarboxylic acid or its salt, the content of the hydrophilic compound, preferably a hydroxycarboxylic acid or its salt, is preferably 0.01% to 50% by mass, more preferably 0.1% to 40% by mass, and especially preferably 1.0% to 30% by mass, relative to the total mass of the base coating.

[0786] 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.

[0787] The primer layer can be applied using known methods.

[0788] 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 .

[0789] The original lithographic printing plate involved in this invention may have other layers besides those described above.

[0790] 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.

[0791] (Methods for making offset printing plates and offset printing methods)

[0792] The preferred method for manufacturing the lithographic printing plate of the present invention includes: a step of exposing the original lithographic printing plate of the present invention to an image (exposure step); and a step of supplying at least one of printing ink and dampening solution to the exposed original lithographic printing plate on a printing press to remove the image recording layer of the non-image area (on-machine development step).

[0793] The offset printing method of the present invention preferably includes: a step of exposing the offset printing plate of the present invention to an image (exposure step); a step of producing an offset printing plate by supplying at least one 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").

[0794] <Exposure Process>

[0795] 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 into an image shape and forming an exposed portion and an unexposed portion. The original lithographic printing plate according to the present invention is preferably exposed to an image shape by laser exposure using a transparent original image having line images, halftone images, etc., or by laser beam scanning based on digital data.

[0796] A light source with a wavelength of 750 nm to 1,400 nm is preferably used. As a light source with a wavelength of 750 nm to 1,400 nm, solid-state lasers and semiconductor lasers that radiate infrared radiation are preferred. Regarding the infrared laser, 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.

[0797] 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.

[0798] <On-machine developing process>

[0799] The method for manufacturing the lithographic printing plate according to the present invention preferably includes an on-machine developing step of supplying at least one of printing ink and dampening solution to a printing press to remove the image recording layer of the non-image area.

[0800] The following is an explanation of the on-machine development method.

[0801] [In-machine development method]

[0802] 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.

[0803] That is, if the lithographic printing plate is directly mounted on the printing press after image exposure without any development treatment, or if the lithographic printing plate is mounted on the printing press and then image exposure is performed on the printing press, followed by the supply of oil-based ink and water-based components for printing, then in the initial stage of printing, in the non-image section, the uncured image recording layer, due to the supply of either or both of the oil-based ink and water-based components, is dissolved or dispersed and removed, thereby exposing the hydrophilic surface to that area. On the other hand, in the exposure section, the image recording layer cured by exposure forms an oil-based ink receiving section with an oleophilic surface. The compound initially supplied to the plate can be either oil-based ink or water-based components, but from the perspective of preventing contamination of the image recording layer due to the removal of water-based components, it is preferable to initially supply oil-based ink. In this way, the lithographic printing plate is developed on the printing press and directly used in multi-sheet printing. As the oil-based ink and water-based components, conventional lithographic printing inks and dampening solutions are preferred.

[0804] 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.

[0805] <Printing Process>

[0806] 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.

[0807] 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.

[0808] Furthermore, dampening solution can be supplied as needed during the aforementioned printing process.

[0809] 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.

[0810] As a recording medium, there are no particular restrictions, and any known recording medium can be used as needed.

[0811] In the method for producing a lithographic printing plate from the lithographic printing plate master according to the present invention, and in the lithographic printing method according to the present invention, the entire surface of the lithographic printing plate master can be heated as needed before exposure, during exposure, and during the exposure to development period. This heating promotes the image formation reaction in the image recording layer, resulting in advantages such as improved sensitivity or print durability, and stabilized sensitivity. Regarding heating before development, it is preferable to perform the heating under mild conditions below 150°C. This prevents problems such as curing of non-image areas. For heating after development, it is preferable to use 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.

[0812] Example

[0813] 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 polymeric compounds, except for specifically defined polymeric 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).

[0814] (Examples 1 to 38 and Comparative Examples 1 to 6)

[0815] <Fabrication of Supports A and B>

[0816] <<Processing A and B>>

[0817] (Aa) Alkali etching treatment

[0818] 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 .

[0819] (Ab) Acidic aqueous solution was used for decontamination treatment (first decontamination treatment).

[0820] 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.

[0821] (Ac) Electrochemical roughening treatment

[0822] 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.

[0823] 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.

[0824] (Ad) Alkali etching treatment

[0825] 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.

[0826] (Ae) used acidic aqueous solution for decontamination treatment.

[0827] 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.

[0828] (Af) Stage 1 Anodizing Treatment

[0829] Using based Figure 3 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.

[0830] (Ag) Hole Enlargement Treatment

[0831] 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-enlarging treatment. Afterwards, a spray-based water washing process was performed.

[0832] (Ah) Stage 2 Anodizing Treatment

[0833] Using based Figure 3 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.

[0834] [Table 1]

[0835]

[0836] <Fabrication of Supports C to E>

[0837] <<Surface Treatment C>>

[0838] (Ca) Mechanical roughening treatment (brushing method)

[0839] Pumice suspension (specific gravity 1.1 g / cm³) 3 While being supplied to the surface of the aluminum plate as a grinding slurry, it undergoes mechanical roughening treatment by rotating stiff bristle brushes.

[0840] 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 diameters of 0.3mm and bristle lengths 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.

[0841] (Cb) Alkali etching treatment

[0842] 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 / m². 2 .

[0843] (Cc) Decontamination treatment in acidic aqueous solution

[0844] 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.

[0845] (Cd) Electrochemical roughening treatment

[0846] Electrochemical roughening was performed continuously using nitric acid electrolysis at an AC voltage of 60 Hz. The electrolyte used was an aqueous solution of nitric acid at 35°C with 10.4 g / L, to which aluminum nitrate was added to adjust the aluminum ion concentration to 4.5 g / L. A trapezoidal rectangular wave AC current with a current-to-peak time (tp) of 0.8 msec, a duty ratio of 1:1, and a current-to-peak time (duty ratio of 1:1) was used, with a carbon electrode as the counter electrode. Ferrite was used as the auxiliary anode. The current density, measured at the peak current, was 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. 2 Then, a spray-based water wash was performed.

[0847] (Ce) alkaline etching treatment

[0848] 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 .

[0849] (Cf) Decontamination treatment in acidic aqueous solutions

[0850] 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.

[0851] (Cg) Electrochemical roughening treatment

[0852] Electrochemical roughening was performed continuously using hydrochloric acid electrolysis at a 60Hz AC voltage. The electrolyte was an aqueous solution at 35°C with 6.2 g / L hydrochloric acid, to which aluminum chloride was added to adjust the aluminum ion concentration to 4.5 g / L. A trapezoidal rectangular wave AC current with a current-to-peak time (tp) of 0.8 msec, a duty ratio of 1:1, and using a carbon electrode as the counter electrode was employed for electrochemical roughening. Ferrite was used as the auxiliary anode.

[0853] 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.

[0854] (Ch) Alkali etching treatment

[0855] 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 .

[0856] (Ci) Decontamination treatment in acidic aqueous solution

[0857] 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.

[0858] (Cj) Stage 1 Anodizing Treatment

[0859] Using based Figure 3 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 3 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.

[0860] (Ck) Hole Enlargement Treatment

[0861] 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 with 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.

[0862] (Cl) Stage 2 Anodizing Treatment

[0863] Using based Figure 3 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.

[0864] (Cm) Stage 3 Anodizing Treatment

[0865] Using based Figure 3 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.

[0866] <<Surface Treatment D>>:

[0867] [A support body with both large-diameter and small-diameter bores]

[0868] (Da) Alkali etching treatment

[0869] 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 nozzle. A water wash based on the sprayer was then performed. The aluminum dissolution rate on the surface after electrochemical roughening was 1.0 g / m². 2 .

[0870] (Db) Decontamination treatment in acidic aqueous solution (first decontamination treatment)

[0871] 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.

[0872] (Dc) Electrochemical roughening treatment in hydrochloric acid aqueous solution

[0873] 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, a frequency of 50 Hz, and the ratio of the anodic reaction time to the cathode reaction time in one cycle was 1:1. The current density, measured as 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.

[0874] (Dd) Alkali Etching Treatment

[0875] 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.

[0876] (De) Decontamination treatment in acidic aqueous solutions

[0877] 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.

[0878] (Df) Stage 1 Anodizing Treatment

[0879] Using based Figure 3 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.

[0880] (Dg) Hole Enlargement Treatment

[0881] 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 with 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.

[0882] (Dh) Stage 2 Anodizing Treatment

[0883] Using based Figure 3 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.

[0884] The supports C to E described in Tables 2 and 3 were obtained by the above surface treatments C or D.

[0885] 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. 2 The 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.

[0886] 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 diameter of enlarged pores within the small-diameter pores is measured, the upper part of the anodic oxide film is cut, and then various diameters are determined.

[0887] The depth of the micropores (the depth of the large-diameter pores and the small-diameter pores) is as follows: the depth of the support (anodic oxide film) is observed using FE-SEM (150,000x magnification for the large-diameter pores and 50,000x magnification for the small-diameter pores). The depth of any 25 micropores in the obtained image is measured and averaged.

[0888] 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.

[0889] [Table 2]

[0890]

[0891] [Table 3]

[0892]

[0893] <Methods for forming base coatings A to C>

[0894] On the supports listed in Tables 5 to 8, 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 Tables 5 to 8 and drying it in an oven at 100°C for 30 seconds.

[0895] -Composition of Primer Coating Solution A-

[0896] • Polymer (U-1) [structured as follows]: 0.18 parts

[0897] • Hydroxyethyliminodiacetic acid: 0.10 parts

[0898] • Water: 61.4 parts

[0899] [Chemical Formula 47]

[0900]

[0901] -Composition of Primer Coating Solution B-

[0902] • Polymer (U-1): 0.14 parts

[0903] • Sodium gluconate: 0.07 parts

[0904] • Surfactant (EMALEX 710, manufactured by NIHON EMULSION Co., Ltd.): 0.0016 parts by weight

[0905] • Preservative (manufactured by Biohope L, K•I Chemical Industry Co., LTD.): 0.0015 parts

[0906] • Water: 3.29 parts

[0907] -Composition of the primer coating liquid C-

[0908] • Polymer (U-1): 0.14 parts

[0909] •Chelest400: 0.035 servings

[0910] •Chelest3EAF: 0.035 servings

[0911] • Surfactant (EMALEX 710, manufactured by NIHON EMULSION Co., Ltd.): 0.0016 parts by weight

[0912] • Preservative (manufactured by Biohope L, K•I Chemical Industry Co., LTD.): 0.0015 parts

[0913] • Water: 3.29 parts

[0914] Synthesis of Polymer (U-1)-

[0915] <<Purification of monomer M-1>>

[0916] 420 parts of LIGHT ESTER P-1M (2-methacryloyloxyethyl phosphate, manufactured by KYOEISHA 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.

[0917] <<Synthesis of Polymer (U-1)>>

[0918] 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 Corporation) were added, 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.

[0919] [Chemical Formula 48]

[0920]

[0921] <<Composition of Added Solution 1>>

[0922] • 87.59 parts of the above monomer M-1 aqueous solution

[0923] • Monomer M-2: 14.63 parts

[0924] •VA-046B (2,2'-Azobis[2-(2-imidazolin-2-yl)propane] disulfate dihydrate, manufactured by FUJIFILMWako Pure Chemical Corporation): 0.386 parts

[0925] • Distilled water: 20.95 parts

[0926] <Formation of Image Recording Layers>

[0927] The image recording layer coating solution with the composition described in Tables 5 to 8 (wherein, the image recording layer coating solution contains each component described in Tables 5 to 8, 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). Furthermore, the amounts added as described in Tables 5 to 8 represent the amount of solids other than the inorganic layered compound dispersion.) was rod-coated onto a support or primer and dried at 120°C for 40 seconds to form the image recording layer with the dry coating amount described in Tables 5 to 8.

[0928] The following shows the components used in the image recording layer.

[0929] [Oil-based]

[0930] O-1~O-13: The following compounds (physical properties are shown in Table 4 below).

[0931] [Chemical Formula 49]

[0932]

[0933] [Table 4]

[0934]

[0935] [Infrared absorber]

[0936] IR-1~IR-10: Compounds with the following structures

[0937] [Chemical Formula 50]

[0938]

[0939] Additionally, Bu represents n-butyl, Ph represents phenyl, and TsO - This indicates the p-toluenesulfonate anion.

[0940] Electron-receiving polymerization initiators

[0941] Int-1~Int-5: Compounds with the following structures, plus TsO - denoted as p-toluenesulfonate anion, and Ph represents phenyl.

[0942] [Chemical Formula 51]

[0943]

[0944] [Electron-donating polymerization initiators]

[0945] B-1~B-4: Compounds with the following structures

[0946] [Chemical Formula 52]

[0947]

[0948] [Polymerizing compounds]

[0949] M-1: The following compounds

[0950] M-2: The following compounds

[0951] M-3: Dipentaerythritol pentaacrylate, manufactured by Sartomer Company, Inc., SR-399

[0952] M-4: Carbamate acrylate, U-15HA manufactured by Shin-Nakamura Chemical Co., Ltd.

[0953] M-5: A monomer synthesized by the following synthetic method

[0954] [Chemical Formula 53]

[0955]

[0956] <M-5 Synthesis>

[0957] 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., with the NCO value of Takenate D-160N and the hydroxyl value of ARONIX M-403 in a 1:1 ratio), 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 KASEICO., LTD., 0.11 parts) was added to the reaction solution, and the mixture 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 50% by weight solution of urethane acrylate in solids. Molecular weight fractionation of urethane acrylate (M-5) solutions was performed using a reusable GPC (equipment: LC908-C60, columns: JAIGEL-1H-40 and 2H-40 (manufactured by Japan Analytical Industry)) with tetrahydrofuran (THF) as the eluent. The weight-average molecular weight was 20,000.

[0958] [Adhesive polymers]

[0959] P-1: Polyvinyl alcohol, S-LEC BX-5Z manufactured by SEKISUI CHEMICAL CO., LTD.

[0960] P-2: Polyvinyl alcohol, S-LEC BL10 manufactured by SEKISUI CHEMICAL CO., LTD.

[0961] P-3: Resin synthesized by the following method

[0962] <Synthesis of Adhesive Polymer P-3>

[0963] 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 Nippon Oil and Fats Company, Limited), 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 (2,2'-azobis(isobutyrate) dimethyl ester, manufactured by WakoPure Chemical Industries, Ltd.), 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.

[0964] 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.

[0965] 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.

[0966] 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.

[0967] [Chemical Formula 54]

[0968]

[0969] [Acid colorimetric reagent]

[0970] S-1~S-8: The following compounds

[0971] [Chemical Formula 55]

[0972]

[0973] Additionally, Me represents methyl and Et represents ethyl.

[0974] [Chromatol compounds]

[0975] Curcumin: the following compound

[0976] [Chemical Formula 56]

[0977]

[0978] [Hydrophilic compounds]

[0979] T-1: Tris(2-hydroxyethyl) isocyanurate

[0980] T-2: Compounds with the following structures

[0981] T-3: Hydroxypropyl cellulose, Klucel M, manufactured by Hercules.

[0982] [Chemical Formula 57]

[0983]

[0984] [surfactants]

[0985] F-1: Anionic surfactant, RAPISOL A-80, manufactured by NOF CORPORATION.

[0986] F-2: Fluorinated surfactant, Megafac F-781F (manufactured by DIC CORPORATION)

[0987] F-3: The following compounds

[0988] [Chemical Formula 58]

[0989]

[0990] [Polymer particles]

[0991] <Preparation of Polymer Particles R-1>

[0992] • Microgel (polymer particles R-1): 2.640 parts

[0993] • Distilled water: 2.425 parts

[0994] The preparation method of the above-mentioned microgels is shown below.

[0995] Preparation of polyisocyanate compounds-

[0996] 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 mixed with 0.043 parts of tris(2-ethylhexanoate) bismuth (NEOSTANN U-600, manufactured by NITTO KASEI CO., LTD.) and stirred. The reaction temperature was set at 50°C when heating was inhibited, and the mixture was stirred for 3 hours to obtain an ethyl acetate solution (50% by mass) of the polyisocyanate compound (1).

[0997] [Chemical Formula 59]

[0998]

[0999] -Preparation of microgels-

[1000] The oil and aqueous phases were mixed and emulsified at 12,000 rpm for 10 minutes using a homogenizer. The resulting emulsion was stirred at 45°C for 4 hours, and then 5.20 g of a 10% (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.

[1001] ~Oil phase ingredients~

[1002] (Component 1) Ethyl acetate: 12.0 parts

[1003] (Component 2) An adduct (50% by mass ethyl acetate solution, manufactured by Mitsui Chemicals, Inc.) formed by adding trimethylolpropane (6 molar equivalents) and xylene diisocyanate (18 molar equivalents) to it, followed by the addition of monoterminated methylated polyoxyethylene (1 molar equivalent, number of repeats of oxyethylidene units: 90): 3.76 parts

[1004] (Component 3) Polyisocyanate compound (1) (as a 50% by mass ethyl acetate solution): 15.0 parts

[1005] (Component 4) 11.54 parts of 65% by weight ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartamer Company, Inc.)

[1006] (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.).

[1007] ~Aqueous phase composition~

[1008] Distilled water: 46.87 parts

[1009] <Production of Polymer Particles R-2>

[1010] -Preparation of oil phase components-

[1011] 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.

[1012] [Chemical Formula 60]

[1013]

[1014] -Preparation of Aqueous Phase Components-

[1015] 47.2g of distilled water was prepared as the aqueous phase component.

[1016] -Microencapsulation process-

[1017] An emulsion was obtained by adding an aqueous phase component to the oil phase component and mixing them, and then emulsifying the resulting mixture at 12,000 rpm for 16 minutes using a homogenizer.

[1018] 16.8 g of distilled water was added to the obtained emulsion, and the resulting liquid was stirred at room temperature for 10 minutes.

[1019] 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% (w / w) aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-en-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% (w / w) 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.

[1020] <Preparation of Polymer Particles R-3>

[1021] A dispersion unit consisting of the following compound B-1 (n=45): 10.0 parts, 85.0 parts distilled water, and 240.0 parts n-propanol was added to a four-necked flask and heated and stirred at 70°C under nitrogen.

[1022] 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.

[1023] 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.

[1024] The reaction solution was naturally cooled to room temperature (25°C) to obtain a dispersion of polymer particles R-3 (solid content 23%).

[1025] [Chemical Formula 61]

[1026]

[1027] The median particle size of polymer particles R-3 is 150 nm, and the coefficient of variation is 23%.

[1028] 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.

[1029] <Preparation of Polymer Particles R-4>

[1030] In a three-necked flask, 350 parts of distilled water, 50 parts of compound A-1, 20 parts of compound A-2, 20 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.

[1031] [Chemical Formula 62]

[1032]

[1033] <Preparation of Polymer Particles R-5>

[1034] 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.

[1035] 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.

[1036] 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.

[1037] [Chemical Formula 63]

[1038]

[1039] [Chemical Formula 64]

[1040]

[1041] <Formation of the outer coating>

[1042] The following outer coating liquid (1) (which contains the components listed in Tables 5 to 8 and is prepared by ion-exchange water to a solid content of 6% by mass) was applied to the image recording layer by a rod and dried in an oven at 120°C for 60 seconds to form an outer coating with the dry coating amount listed in Tables 5 to 8.

[1043] In addition, the preparation method of the inorganic layered compound dispersion used in the outer coating liquid (1) is described below.

[1044] <<Preparation of Inorganic Layered Compound Dispersions>>

[1045] 6.4 parts of synthetic mica (SOMASIF ME-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.

[1046] [Color-changing compounds]

[1047] wIR-1~wIR-3: The following compounds

[1048] [Chemical Formula 65]

[1049]

[1050] [Hydrophilic polymers]

[1051] WP-1: Polyvinyl alcohol, Mowiol 4-88 manufactured by Sigma-Aldrich Co. LLC.

[1052] WP-2: Polyvinyl alcohol, Mowiol 8-88 manufactured by Sigma-Aldrich Co. LLC.

[1053] WP-3: The following resins

[1054] WP-4: Cellulose, METOLOSE 60SH-15 manufactured by Shin-Etsu Chemical Co., Ltd.

[1055] WP-5: Polyvinyl alcohol, Gohsenol L-3266 manufactured by Mitsubishi Chemical Corporation, with a saponification degree of 86%–89% or higher.

[1056] WP-6: Cellulose, METOLOSE SM04 manufactured by Shin-Etsu Chemical Co., Ltd.

[1057] WP-7: The following resin (Mw=30,000)

[1058] [Chemical Formula 66]

[1059]

[1060] [Chemical Formula 67]

[1061]

[1062] [Hydrophobic polymers]

[1063] L-1: Aqueous dispersion of polyvinylidene chloride, manufactured by Solvin Company, Diofan (registered trademark) A50

[1064] L-2: Styrene-acrylic resin, FS-201 manufactured by Nipponpaint Industrial Coatings Co., LTD.

[1065] L-3: Styrene-acrylic resin, FS-102 manufactured by Nipponpaint Industrial Coatings Co., LTD.

[1066] <Production of the original lithographic printing plate>

[1067] As described in Tables 5 to 8, original offset printing plates for Examples 1 to 38 and Comparative Examples 1 to 6 were produced according to the method of forming the support and each of the above layers.

[1068] <Evaluation of the original lithographed version>

[1069] Using a Kodak Magnus800 Quantum equipped with an infrared semiconductor laser, the original lithographic printing plate produced in the above manner was exposed under the following conditions: output power 27W, external drum speed 450rpm, and resolution 2,400dpi (dots per inch, 1 inch is 2.54cm). (Equivalent to irradiation energy 110mJ / cm²) 2 The exposed image includes a solid image, an amplitude modulation screen (AM) 3% dot plot, and a frequency modulation screen (FM) 20% dot plot.

[1070] [In-machine developability]

[1071] The obtained exposed original was mounted on the cylinder 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&K UV OFS K-HS ink GE-M (manufactured by T&K TOKA Corporation) was used as the printing ink. After supplying the dampening solution and ink through a standard automatic printing start-up method, 500 sheets were printed at a printing speed of 10,000 sheets per hour on Tokubishi Art (continuous yield: 76.5kg, manufactured by Mitsubishi Paper Mills Limited) paper.

[1072] In the above-mentioned in-machine development, the number of sheets of printing paper required to prevent ink transfer to the non-image area was measured as the in-machine developability. The measurement results are recorded in Tables 5 to 8. The fewer the number of sheets, the better the in-machine developability.

[1073] [UV-curable ink printing durability (UV printing durability)]

[1074] After evaluating the on-machine developability as described above, printing continued. As the number of prints increased, the image area gradually wore down, resulting in a decrease in ink density on the printed material. Printing durability was evaluated by determining the number of prints at which 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 print. Relative printing durability was evaluated using a print run of 50,000 prints as a baseline of 100. A higher value indicates better printing durability. The evaluation results are recorded in Tables 5 to 8.

[1075] Relative print durability = (Number of prints of the original offset printing plate) / 50,000 × 100

[1076] [Inkability (Specialty Ink Inkability)]

[1077] The specialty ink Epple Pantone Blau 072C (manufactured by Epple) was used as the ink, and printing was performed in the same manner as described above for UV printing durability. The ink density at the 20% FM dot area was investigated using a Gretag density meter on the 10,000th sheet of printed paper as a sample. Based on the measured values ​​(rounded to two decimal places), the evaluation of the specialty ink's inking properties is shown in Tables 5 to 8 according to the following indicators.

[1078] -Evaluation Criteria-

[1079] A: Ink concentration is 1.8-1.9: The ink concentration has not decreased at all, and the ink adherence is good.

[1080] B: Ink concentration is 1.5–1.7: Although the ink concentration is slightly reduced, it is still at an acceptable level.

[1081] C: Ink concentration of 1.0–1.4: The ink concentration is significantly reduced and reaches an unacceptable level.

[1082] D: Ink concentration below 0.9: Ink concentration decreases and deteriorates.

[1083] [Inhibition of Turbidity in Dampening Solution]

[1084] After adjusting the water-ink balance using an adjustment plate (Fujifilm Corporation XP-F), 1,000 sheets were printed. Then, the adjustment plate was removed, and the blanket was cleaned. Next, the ink fountain key was set to zero. The dampening solution used during adjustment was discarded, and fresh dampening solution was added. At this point, the dampening solution circulation system was stopped, and the outlet was sealed with a rubber stopper.

[1085] Next, the actions X1 to X3 below were repeated 10 times.

[1086] X1: The original lithographic printing plate (unexposed version) was dampened 50 times by manual pre-wetting.

[1087] X2: After 50 dampenings, 100 sheets were printed on Shiraoi (high-quality paper, manufactured by NIPPON PAPER INDUSTRIES CO.,LTD.).

[1088] X3: Uninstalled version.

[1089] Furthermore, the printing conditions are shown below.

[1090] Printing press: Lithrone LS26 / 104 manufactured by KOMORI Corporation.

[1091] Ink: UV ink (UV CORE TYPE-AJ, yellow, manufactured by T&K TOKA Corporation)

[1092] Dampening solution: PRESSMAX S-Z1 2% (manufactured by Fujifilm Corporation)

[1093] Pre-wetting: 50 times

[1094] Then, the rubber stopper was removed, the dampening solution was recovered, and the turbidity was evaluated by the transparency of the dampening solution. Transparency was measured according to JIS K0102 (2019) and evaluated according to the following standards. The evaluation results are recorded in Tables 5 to 8.

[1095] -Evaluation Criteria-

[1096] A: The transparency is 8cm or more.

[1097] B: Transparency is 5cm or more but less than 8cm

[1098] C: Transparency less than 5cm

[1099] [Table 5]

[1100]

[1101] [Table 6]

[1102]

[1103] [Table 7]

[1104]

[1105] [Table 8]

[1106]

[1107] In addition, ΔE1 represents the LUMO of the electron-donating polymerization initiator versus the LUMO of the infrared absorber, and ΔE2 represents the HOMO of the infrared absorber versus the HOMO of the electron-donating polymerization initiator.

[1108] As can be seen from the results recorded in Tables 5 to 8, the lithographic printing plate originals involved in the embodiments, compared with the lithographic printing plate originals involved in the comparative examples, are lithographic printing plate originals with superior UV printing durability, on-machine developability, and dampening solution turbidity suppression. Furthermore, it can be seen that the lithographic printing plate originals involved in the present invention can also produce lithographic printing plates with excellent ink adhesion.

[1109] The entire contents of the publications of Japanese Patent Application No. 2021-012032, filed on January 28, 2021, and Japanese Patent Application No. 2021-061164, filed on March 31, 2021, are incorporated herein by reference.

[1110] 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.

[1111] Symbol Explanation

[1112] 12a, 12b - Aluminum support, 14 - Base coating, 16 - Image recording layer, 18 - Aluminum plate, 20a, 20b - Anodized film, 22a, 22b - Micropores, 24 - Large diameter hole, 26 - Small diameter hole, D - Depth of large diameter hole, 610 - Anodizing treatment device, 612 - Power supply tank, 614 - Electrolytic treatment tank, 616 - Aluminum plate, 618, 26 - Electrolyte, 620 - Power supply electrode, 622, 628 - Rollers, 624 - Clamping roller, 630 - Electrolytic electrode, 632 - Tank wall, 634 - DC power supply.

Claims

1. An on-machine developing type lithographic printing plate master, which sequentially comprises a support, an image recording layer, and an outer coating layer. The outer coating contains no inorganic compounds, or the content of inorganic compounds relative to the total mass of the outer coating is greater than 0% by mass and less than 1% by mass. The image recording layer comprises an infrared absorber, a polymerization initiator, a polymerization compound, and an oil. The oil refers to a hydrophobic compound that is liquid at 1 atmosphere and 80°C, and that separates without mixing when mixed with the same mass of water. The polymerization initiator includes an electron-donating polymerization initiator, which is a borate compound.

2. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The oil agent contains an oil agent with a boiling point of 300°C or higher.

3. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The oil agent comprises two or more oil agents with different structures.

4. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The clogP value of the oil is greater than or equal to 5.

0.

5. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The content of the oil is 0.0001% to 10.0% by mass relative to the total mass of the image recording layer.

6. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The content of the oil relative to the total mass of the image recording layer is 0.0001% by mass to 2800 / 1757% by mass.

7. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The content of the oil relative to the total mass of the image recording layer is 0.0001% by mass to 2500 / 1597% by mass.

8. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The HOMO value of the infrared absorber and the HOMO value of the electron-donating polymerization initiator are below 0.70 eV.

9. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The polymerization initiator includes an electron-accepting polymerization initiator. The LUMO of the electron-accepting polymerization initiator and the LUMO of the infrared absorber are both below 0.70 eV.

10. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The polymeric compound comprises polymeric compounds with seven or more functions.

11. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The polymeric compound comprises polymeric compounds with 10 or more functions.

12. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The image recording layer also contains polymer particles.

13. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The outer coating comprises a hydrophilic polymer.

14. The on-machine developing type lithographic printing plate original according to claim 13, wherein, The hydrophilic polymer contains cellulose derivatives.

15. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The polymeric compound comprises polymeric compounds with two or fewer functions.

16. The on-machine developing type lithographic printing plate original according to claim 9, 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 represents an aryl group.

17. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The image recording layer also contains polyvinyl butyral.

18. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The outer coating comprises a hydrophobic polymer.

19. The on-machine developing type lithographic printing plate original according to claim 18, wherein, The hydrophobic polymer is hydrophobic polymer particles.

20. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The outer coating also contains a color-changing compound.

21. The on-machine developing type lithographic printing plate original according to claim 20, wherein, The color-changing compound includes decomposable compounds that decompose upon exposure to infrared light.

22. The on-machine developing type lithographic printing plate original according to claim 20, wherein, The color-changing compound is anthocyanin.

23. The on-machine developing type lithographic printing plate original according to claim 20, wherein, The color-changing compound is a compound represented by the following formula 1-1. In Equation 1-1, R 1 R represents a group represented by any one of the following formulas 2-1 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 Optional linkages form single or multiple rings, where A1 and A2 independently represent oxygen, sulfur, or nitrogen atoms, respectively, and n 11 and n 12 Each of the integers from 0 to 5 can be represented independently, where n 11 and n 12 The total is 2 or more, n 13 and n 14 Each can be independently represented as 0 or 1, and L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 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.

24. The on-machine developing type lithographic printing plate original according to claim 20, wherein, The color-changing compound is a compound represented by the following formulas 1-2. In Equation 1-2, R 1 R represents 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 The rings can be optionally linked to form a single or multiple rings, where L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 R represents a hydrogen atom, alkyl group, or aryl group. d1 ~R d4 W 1 and W 2 Each of these independently represents an alkyl group optionally having a substituent, and Za represents a counterion that neutralizes the charge.

25. The on-machine developing type lithographic printing plate original according to claim 20, wherein, The chromogenic compound is a compound represented by any one of the following formulas 1-3 to 1-7. In equations 1-3 to 1-7, R 1 R represents 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 The rings can be optionally linked to form a single or multiple rings, where L represents an oxygen atom, a sulfur atom, or -NR. 10 -, R 10 R represents a hydrogen atom, alkyl group, or aryl group. d1 ~R d4 W 1 and W 2 Each of these independently represents an alkyl group optionally having a substituent, and Za represents a counterion that neutralizes the charge.

26. The on-machine developing type lithographic printing plate original according to claim 24, 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-, a sulfonyl group, a salt of a sulfonyl group, a carboxyl group, or a salt of a carboxyl group as the substituent.

27. 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 26 into an image; and A process of supplying at least one of printing ink and dampening solution to a printing press to remove the image recording layer from the non-image area.

28. 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 26 into an image; The process of producing a lithographic printing plate by supplying at least one of printing inks and dampening solutions to remove an image recording layer (excluding the image portion) from a printing press; and The process of printing using the obtained lithographic printing plate.

Images