On-press developing lithographic printing plate precursor and method for producing printing plate

Abstract

The present invention provides an on-press development type lithographic printing plate precursor and a method for manufacturing a printing plate, the on-press development type lithographic printing plate precursor having an image recording layer on a support, the image recording layer contains a chromophoric compound having a group that cleaves by infrared exposure, a polymerization initiator, a polymerizable compound, and a hydrogen-donating compound, and the hydrogen-donating compound is a compound different from the polymerization initiator, the polymerizable compound, the chromophoric compound, and the acid-cleaving compound. And a compound having a molecular weight of less than 3,000 and having at least one group selected from the group consisting of-OH,-NH-,-SO2-NH-,-SO2-OH,-CO-NH-, and-CO-OH in the molecule.

Description

Technical Field

[0001] This invention relates to a method for manufacturing an on-machine developing type lithographic printing plate master and a printing plate. 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 mutual repulsion between 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 a substrate such as paper for printing.

[0003] Currently, in the plate-making process of creating lithographic printing plates from lithographic printing master plates, image exposure is performed based on CTP (Computer-to-Plate) technology. That is, image exposure is performed directly on the lithographic printing master plate using lasers or laser diodes through scanning exposure, without going through high-contrast film.

[0004] On the other hand, due to increased concern for the Earth's environment, environmental problems related to the production of lithographic printing plates and the waste liquid associated with wet processing such as developing have become apparent. Consequently, simplifying or eliminating the developing process has become a trend. As one of the simplest developing processes, a method called "in-machine developing" has been proposed. In-machine developing is as follows: after the lithographic printing plate is exposed to the image, it is directly mounted on the printing press without the usual wet developing process, and the non-image areas of the image recording layer are removed in the initial stage of the normal printing process.

[0005] Patent Document 1 describes a lithographic printing plate original having an image recording layer on a support, wherein the image recording layer comprises an infrared absorber that decomposes upon infrared exposure, an adhesive polymer having structural units formed of aromatic vinyl compounds, a polymerization initiator, and a polymerizable compound.

[0006] Patent document 2 describes a color-generating composition comprising an acid-generating agent, a tetraarylborate, an acid-sensitive dye precursor, and a compound having a specific structure (I).

[0007] Previous technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2020-69789

[0010] Patent Document 2: Japanese Patent No. 7280351 Summary of the Invention

[0011] The technical problem to be solved by the invention

[0012] When a lithographic printing plate is mounted on a printing press, the image of the exposed areas is typically visually identified. In conventional wet development, since the lithographic plate with the non-image areas removed is mounted on the printing press, the image of the exposed areas in the lithographic plate is easily visually identified. However, in on-machine development, since the lithographic printing plate with the non-image areas still removed is mounted on the printing press, it is often difficult to visually identify the aforementioned image of the lithographic plate.

[0013] Based on the above, and in order to improve the color development in the exposure section, a lithographic printing plate master containing a color-developing compound having groups that are cleaved by infrared exposure has been developed in the image recording layer.

[0014] Here, the original lithographic printing plate is usually stored under white light after exposure. However, it has been found that in original lithographic printing plates containing chromogenic compounds with groups that are broken down by infrared exposure on the image recording layer, the visual clarity of the exposed area tends to deteriorate, especially after storage under white light. On the other hand, when chromogenic compounds with groups that are broken down by infrared exposure are not used in order to suppress the deterioration of the visual clarity of the image area after storage under white light, it has been observed that the good visual clarity of the exposed area immediately after exposure is difficult to maintain.

[0015] The present invention was made in view of the above, and its object is to provide an on-machine developing type lithographic printing plate original and a method for manufacturing a printing plate using the on-machine developing type lithographic printing plate original. In the above-mentioned on-machine developing type lithographic printing plate original, the visual recognition in the exposure section is good immediately after exposure, the good visual recognition immediately after exposure is easy to maintain, and the visual recognition in the exposure section is also good after storage under white light.

[0016] means for solving technical problems

[0017] The following describes the methods used to solve the above problems.

[0018] [1] An on-machine developing type lithographic printing plate master, which has an image recording layer on a support.

[0019] The image recording layer comprises a chromophore compound having groups that cleave upon infrared exposure, a polymerization initiator, a polymerization compound, and a hydrogen-donating compound.

[0020] The aforementioned hydrogen-donating compound is a compound that is different from the aforementioned polymerization initiator, the aforementioned polymerizable compound, the aforementioned chromogenic compound and acid-crackable compound, and is a compound having at least one group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH- and -CO-OH and having a molecular weight of less than 3,000.

[0021] [2] According to the machine-developable lithographic printing plate original described in [1], wherein,

[0022] The aforementioned hydrogen-donating compound is a compound having at least one partial structure represented by the following formula (I) within the molecule.

[0023] [Chemical Formula 1]

[0024]

[0025] In formula (I),

[0026] X is a hydrogen-donating group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH.

[0027] R 1A ~R 3A Each is independently a group having at least one of the following groups: hydrogen atom, carbon atom, halogen atom and heteroatom.

[0028] R 1A ~R 3A At least two of them can be connected to form a loop.

[0029] When X is a monovalent group, R 1A ~R 3A One or more hydrogen atoms contained in the structure are removed to form a linking bond.

[0030] When X is a divalent group, R 1A ~R 3A One or more hydrogen atoms contained therein can be further removed to form a linking bond.

[0031] [3] According to the machine-developable lithographic printing plate original described in [1] or [2], wherein,

[0032] The aforementioned hydrogen-donating compound is a compound having at least one partial structure represented by the following formula (II) within the molecule.

[0033] [Chemical Formula 2]

[0034]

[0035] In formula (II),

[0036] Ar represents an aromatic cyclic group.

[0037] X is a group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH.

[0038] R 4A It is a group having at least one of the following groups: hydrogen atom, carbon atom, halogen atom and heteroatom.

[0039] m represents an integer from 1 to 5. When m represents an integer greater than 2, multiple X's can be the same or different.

[0040] n represents an integer from 0 to 5. When n represents an integer greater than 2, multiple R... 4A They can be the same or different. When n is 2 or more, multiple R... 4A They can be connected to form a ring.

[0041] When all X are monovalent groups, R 4A One or more hydrogen atoms contained in the structure are removed to form a linking bond.

[0042] When at least one X is a divalent group, R 4A One or more hydrogen atoms contained therein can be further removed to form a linking bond.

[0043] [4] The original lithographic printing plate according to any one of [1] to [3], wherein,

[0044] The aforementioned hydrogen-donating compounds are compounds that have at least one partial structure represented by the following formula (III) within the molecule.

[0045] [Chemical Formula 3]

[0046]

[0047] In formula (III),

[0048] X is a group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH.

[0049] R 5A It is a group having at least one of the following groups: hydrogen atom, carbon atom, halogen atom and heteroatom.

[0050] p represents an integer from 1 to 5. When p represents an integer greater than 2, multiple X's can be the same or different.

[0051] Let q represent an integer from 0 to 5. When q represents an integer greater than 2, multiple R5s can be the same or different. When q is greater than 2, multiple R5s... 5A They can be connected to form a ring.

[0052] p+q is less than 6.

[0053] When all X are monovalent groups, R 5A One or more hydrogen atoms contained therein are removed to form a linking bond.

[0054] When at least one X is a divalent group, R 5A One or more hydrogen atoms contained therein can be further removed to form a linking bond.

[0055] [5] An on-machine developable lithographic printing plate original according to any one of [1] to [4], wherein,

[0056] The aforementioned hydrogen-donating compounds are compounds having at least two groups selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH within the molecule.

[0057] [6] The original lithographic printing plate according to any one of [1] to [5], wherein,

[0058] The aforementioned hydrogen-donating compound has at least one group selected from the group consisting of -OH and -SO2-NH-.

[0059] [7] An on-machine developable lithographic printing plate original according to any one of [1] to [6], wherein,

[0060] The aforementioned hydrogen-donating compound has at least two groups selected from the group consisting of -OH and -SO2-NH-.

[0061] [8] An in-machine developable lithographic printing plate original according to any one of [1] to [7], wherein,

[0062] The aforementioned hydrogen-donating compounds have at least one phenolic hydroxyl group.

[0063] [9] An in-machine developable lithographic printing plate original according to any one of [1] to [8], wherein,

[0064] The aforementioned hydrogen-donating compounds have two or more phenolic hydroxyl groups.

[0065]

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

[0066] The chromophores described above, which have groups that are cleaved by infrared exposure, are anthocyanins represented by Formula 1.

[0067] [Chemical Formula 4]

[0068]

[0069] In Equation 1, R 1 Indicates that R is obtained through infrared exposure. 1 -L bond cleavage group, R 11 ~R 18 Each of these can independently represent a hydrogen atom, a halogen atom, -Ra, -ORb, -SRc, or -NRdRe, where Ra to Re can independently represent hydrocarbon groups, 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 number 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.

[0070]

[11] According to the machine-developable lithographic printing plate original described in

[10] , wherein,

[0071] The chromophores described above that have groups that are cleaved by infrared exposure are compounds represented by Formula 2.

[0072] [Chemical Formula 5]

[0073]

[0074] In Equation 2, R 1 Indicates that R is made by infrared exposure. 1 -L bond cleavage group, R 2 and R 3 Each can be independently represented by a hydrogen atom or an alkyl group, R 2 and R 3 They can be connected to form a ring, Ar 1 and Ar 2 Each group independently represents a group that forms a benzene ring or a naphthalene ring, Y 1 and Y 2 Each of the oxygen atom, sulfur atom, and -NR atom can be represented independently. 0 -or dialkylmethylene, R0 R represents a hydrogen atom, alkyl group, or aryl group. 4 and R 5 Each independently represents an aliphatic hydrocarbon group, R 6 ~R 9 Each can be used independently to represent a hydrogen atom or an alkyl group, and L can represent 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.

[0075]

[12] According to the on-machine developing type lithographic printing plate original described in

[11] , wherein,

[0076] In Equation 2 above, L represents an oxygen atom.

[0077]

[13] According to the machine-developable lithographic printing plate original described in

[12] , wherein,

[0078] R in Equation 2 above 1 It is the group represented by the following formula (5).

[0079] [Chemical Formula 6]

[0080]

[0081] In equation (5), R 15 and R 16 Each of these groups independently represents a hydrogen atom, an alkyl group, or an aryl group; E represents an ononyl group; and * represents the bonding site with the oxygen atom represented by L in Formula 2.

[0082]

[14] The original lithographic printing plate according to any one of [1] to

[13] , wherein,

[0083] Polymerizable compounds include polymerizable compounds with 11 or more functions.

[0084]

[15] The original lithographic printing plate according to any one of [1] to

[14] , wherein,

[0085] The aforementioned polymerization initiators include borate compounds as electron-donating polymerization initiators.

[0086]

[16] The original lithographic printing plate according to any one of [1] to

[15] , wherein,

[0087] The aforementioned polymerization initiators include onium salt compounds as electron-accepting polymerization initiators.

[0088]

[17] The original lithographic printing plate according to any one of [1] to

[16] , wherein,

[0089] In addition to the chromogenic compounds containing groups that are cleaved by infrared exposure, the aforementioned image recording layer also contains an acid chromogenic agent.

[0090]

[18] The original lithographic printing plate according to any one of [1] to

[17] , wherein,

[0091] A protective layer is provided on the aforementioned image recording layer.

[0092]

[19] According to the on-machine developing type lithographic printing plate original described in

[18] , wherein,

[0093] The aforementioned protective layer contains an inorganic layered compound.

[0094]

[20] According to the on-machine developing type lithographic printing plate original described in

[19] , wherein,

[0095] The content of the above-mentioned inorganic layered compounds is 5–80 mg / m³. 2 .

[0096]

[21] The original lithographic printing plate according to any one of [1] to

[20] , wherein,

[0097] The micropores in the anodic oxide film of the aforementioned support are composed of large-diameter pores and small-diameter pores. The large-diameter pores extend from the surface of the anodic oxide film to a depth of 10 nm to 1,000 nm. The small-diameter pores are connected to the bottom of the large-diameter pores and extend from the connection point to a depth of 20 nm to 2,000 nm. The average diameter of the large-diameter pores at the surface of the anodic oxide film is 15 nm to 100 nm, and the average diameter of the small-diameter pores at the connection point is less than 15 nm.

[0098]

[22] The original lithographic printing plate according to any one of [1] to

[20] , wherein,

[0099] The micropores in the anodic oxide film of the aforementioned support are composed of small-diameter pores and large-diameter pores. The small-diameter pores extend from the surface of the anodic oxide film to a depth of 10 nm to 1,000 nm. The large-diameter pores are connected to the bottom of the small-diameter pores and extend from the connection point to a depth of 20 nm to 2,000 nm. The average diameter of the small-diameter pores at the surface of the anodic oxide film is less than 35 nm, and the average maximum diameter of the large-diameter pores is 40 to 300 nm.

[0100]

[23] The original lithographic printing plate according to any one of [1] to

[20] , wherein,

[0101] The aforementioned support has an anodic oxide film.

[0102] The aforementioned anodic oxide film has the following characteristics sequentially from its surface toward its depth:

[0103] The upper layer, with a thickness of 30–500 nm, has micropores with an average diameter of 20–100 nm;

[0104] An intermediate layer with a thickness of 100–300 nm has micropores with an average diameter of 1 / 2 to 5 times the average diameter of the micropores in the upper layer described above; and

[0105] The lower layer, with a thickness of 300–2000 nm, has micropores with an average diameter of less than 15 nm.

[0106]

[24] A method for manufacturing a printing plate includes: a step of exposing an image to an on-machine developing type lithographic printing plate original as described in any one of [1] to

[23] ; and a step of removing the unexposed portion of the image recording layer in the on-machine developing type lithographic printing plate original by supplying at least one of printing ink and dampening solution to a printing press.

[0107] Invention Effects

[0108] According to the present invention, an on-machine developing type lithographic printing plate master and a method for manufacturing a printing plate using the on-machine developing type lithographic printing plate master can be provided. In the above-mentioned on-machine developing type lithographic printing plate master, the visual recognition in the exposure section is good immediately after exposure, the good visual recognition immediately after exposure is easy to maintain, and the visual recognition of the exposure section is also good after storage under white light. Attached Figure Description

[0109] Figure 1 This is a chart showing an example of an alternating current waveform used in electrochemical roughening treatment.

[0110] Figure 2 This is a side view showing an example of a radial unit in an electrochemical roughening process using alternating current.

[0111] Figure 3 This is a schematic diagram showing the cross-sectional shape of the end of the original lithographic printing plate.

[0112] Figure 4 This is a conceptual diagram representing an example of the cutting section of a longitudinal cutting device.

[0113] Figure 5 This is a side view illustrating the concept of a brushing and polishing process used in the mechanical roughening treatment of aluminum supports.

[0114] Figure 6 This is a schematic diagram of an anodizing apparatus used in anodizing processes. Detailed Implementation

[0115] The following description of the constituent elements is based on a representative embodiment of the present invention, but the present invention is not limited to this embodiment.

[0116] In the designation of groups (atomic groups) in this specification, the designations without substitution and unsubstituted groups include not only groups without substituents but also groups with substituents. For example, "alkyl" includes not only alkyl groups without substituents (unsubstituted alkyl) but also alkyl groups with substituents (substituted alkyl).

[0117] 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.

[0118] The term "process" in this specification includes not only independent processes, but also processes that can be clearly distinguished from other processes, as long as the intended purpose of the process can be achieved.

[0119] In this invention, a combination of two or more preferred methods is a more preferred method.

[0120] Unless otherwise specified, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) in this specification are calculated 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), detected by solvent THF (tetrahydrofuran), a differential refractometer, and polystyrene as a standard substance.

[0121] The present invention will now be described in detail.

[0122] [Original plate for in-machine developing lithography]

[0123] An on-machine developing type lithographic printing plate master, which has an image recording layer on a support.

[0124] The image recording layer comprises a chromophore compound having groups that cleave upon infrared exposure, a polymerization initiator, a polymerization compound, and a hydrogen-donating compound, wherein,

[0125] The aforementioned hydrogen-donating compound is a compound that is different from the aforementioned polymerization initiator, the aforementioned polymerizable compound, the aforementioned chromogenic compound and acid-crackable compound, and is a compound having at least one group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH- and -CO-OH and having a molecular weight of less than 3,000.

[0126] According to the in-machine developing type lithographic printing plate original of the present invention, by adopting the above structure, it is possible to obtain an in-machine developing type lithographic printing plate original in the exposure section that has good visual recognition immediately after exposure, good visual recognition immediately after exposure is easy to maintain, and good visual recognition of the exposure section after storage under white light.

[0127] The reasons are unclear, but can be speculated to be as follows.

[0128] To ensure visual clarity in the exposed area, chromogenic compounds containing groups that cleave upon infrared exposure are typically added to the image recording layer of a lithographic printing plate. By including chromogenic compounds containing groups that cleave upon infrared exposure in the image recording layer, the visual clarity of the exposed area immediately after exposure is good, and there is a tendency to maintain good visual clarity immediately after exposure.

[0129] As mentioned above, lithograph originals are typically stored under white light (white fluorescent light) after exposure. However, it is known that in lithograph originals containing chromophores with groups that break down upon infrared exposure on the image recording layer, the visual clarity of the exposed areas tends to deteriorate, especially after storage under white light. This can be presumed to be because the chromophores formed by the chromophores with groups that break down upon infrared exposure in the exposed areas oxidize and decompose when stored under white light, thus failing to maintain the good visual clarity immediately after exposure and easily deteriorating.

[0130] The on-machine developing type lithographic printing plate of the present invention contains a hydrogen-donating compound in the image recording layer. Even when the lithographic printing plate is stored under white light, by having the hydrogen-donating compound and a chromogenic compound having groups that are broken down by infrared exposure coexist in the image recording layer, the oxidative decomposition of the chromophore formed in the exposed section by the chromogenic compound having groups that are broken down by infrared exposure during storage under white light can be suppressed. It is believed that this is because the hydrogen-donating compound supplies hydrogen radicals to the highly reactive peroxide radicals generated in the oxidative decomposition reaction of the chromophore, thus acting as hydrogen peroxide to suppress the oxidative decomposition reaction. Therefore, it is believed that the decrease in visual clarity of the image section after storage under white light can be suppressed.

[0131] Therefore, it is believed that the original in-machine developing type lithographic printing plate can obtain good visual recognition in the exposure section immediately after exposure, easily maintain good visual recognition immediately after exposure, and also have good visual recognition in the exposure section after storage under white light.

[0132] (Original plate for in-machine developing offset printing)

[0133] First, the original offset printing plate of the present invention will be described.

[0134] (Support body)

[0135] As the support, an aluminum support is preferred. The aluminum plate used in such an aluminum support is made of a dimensionally stable metal with aluminum as the main component, i.e., aluminum or an aluminum alloy. It is preferably selected from pure aluminum plates and alloys with aluminum as the main component and containing trace amounts of dissimilar elements.

[0136] Aluminum alloys contain dissimilar elements such as silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of dissimilar elements in the alloy is less than 10% by mass. Pure aluminum plates are preferred, but from a smelting technology perspective, it is difficult to manufacture completely pure aluminum; therefore, alloys containing a small amount of dissimilar elements are acceptable. There are no specific regulations regarding the composition of the aluminum plates used in aluminum supports; well-known aluminum plates such as JIS A 1050, JIS A 1100, JIS A 3103, and JIS A 3005 can be appropriately used.

[0137] The thickness of the support (preferably an aluminum plate) is preferably about 0.1 to 0.6 mm.

[0138] (Anodized film)

[0139] The aforementioned support preferably has an anodic oxide film.

[0140] An anodized film refers to an anodized film (preferably anodized aluminum film) with ultrafine pores (also called micropores) formed on the surface of a support (preferably an aluminum plate) through anodizing treatment. The micropores extend from the surface of the anodized film on the side opposite to the support along the thickness direction (support side, depth direction).

[0141] From the viewpoints of tone reproduction, brush resistance, and blanket staining, the average diameter (average opening diameter) of the micropores on the surface of the anodic oxide film is preferably 7 nm to 150 nm, more preferably 10 nm to 100 nm, even more preferably 10 nm to 60 nm, particularly preferably 15 nm to 60 nm, and most preferably 18 nm to 40 nm.

[0142] The depth of the micropores is preferably 10 nm to 3,000 nm, more preferably 10 nm to 2,000 nm, and even more preferably 10 nm to 1,000 nm.

[0143] The shape of a micropore is usually a roughly straight tube (roughly cylindrical) with its diameter remaining almost unchanged in the depth direction (thickness direction), but it can also be a cone shape with its diameter continuously decreasing in the depth direction (thickness direction). Furthermore, it can also be a shape with its diameter decreasing discontinuously in the depth direction (thickness direction).

[0144] As a type of micropore whose diameter decreases discontinuously in the depth direction (thickness direction), an example of a micropore can be formed by a large-diameter pore portion extending from the surface of the anodic oxide film along the depth direction and a small-diameter pore portion communicating with the bottom of the large-diameter pore portion and extending from the communication position along the depth direction.

[0145] Specifically, the preferred micropores are composed of a large-diameter pore extending 10 nm to 1,000 nm from the surface of the anodic oxide film along the depth direction and a small-diameter pore communicating with the bottom of the large-diameter pore and extending further along the depth direction from the communication position by 20 to 2,000 nm.

[0146] The large-diameter and small-diameter bore sections are described in detail below.

[0147] -Large diameter hole-

[0148] From the viewpoints of tone reproduction, brush resistance, and blanket staining, the average diameter (average opening diameter) of the large-diameter orifice at the surface of the anodic oxide film is preferably 7 nm to 150 nm, more preferably 10 nm to 100 nm, even more preferably 15 nm to 100 nm, particularly preferably 15 nm to 60 nm, and most preferably 18 nm to 40 nm.

[0149] The average diameter of the large-diameter pores was calculated as follows: N=4 anodic oxide film surfaces were observed using a field emission scanning electron microscope (FE-SEM) with a magnification of 150,000x. From the four images obtained, 50 micropores (large-diameter pores) within the range of 400nm×600nm were randomly selected and their diameters were measured. The arithmetic mean was then calculated.

[0150] Additionally, when the shape of a large-diameter hole 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.

[0151] The bottom of the large-diameter hole is preferably located at a depth of 70 nm to 1,000 nm (hereinafter also referred to as depth A) from the surface of the anodic oxide film. That is, the large-diameter hole is preferably a hole extending 70 nm to 1,000 nm from the surface of the anodic oxide film along the depth direction (thickness direction). In terms of improving the effect of the method for manufacturing the lithographic printing plate, the depth A is more preferably 90 nm to 850 nm, further preferably 90 nm to 800 nm, and especially preferably 90 nm to 600 nm.

[0152] In addition, regarding the aforementioned depth, a cross-sectional photograph of the anodized film was taken (150,000x magnification), the depth of more than 25 large-diameter holes was measured, and the result was calculated as an arithmetic mean.

[0153] The shape of the large-diameter hole is not particularly limited. For example, it can be a generally straight tube (generally cylindrical) or a conical shape whose diameter decreases in the depth direction (thickness direction). It is preferably a generally straight tube. Furthermore, the shape of the bottom of the large-diameter hole is not particularly limited. It can be curved (convex) or flat.

[0154] There are no particular restrictions on the inner diameter of the large-diameter aperture, but it is preferable to be the same size as or smaller than the diameter of the opening. Additionally, the inner diameter of the large-diameter aperture can differ from the diameter of the opening by approximately 1 nm to 10 nm.

[0155] -Small Diameter Orifice-

[0156] A small-diameter hole is a hole that communicates with the bottom of a large-diameter hole and extends further along the depth direction (thickness direction) from the communication point. One small-diameter hole is usually connected to one large-diameter hole, but two or more small-diameter holes can communicate with the bottom of one large-diameter hole.

[0157] The average diameter of the small-diameter aperture at the connecting position is preferably 15 nm or less, more preferably 13 nm or less, even more preferably 11 nm or less, and particularly preferably 10 nm or less. There is no particular limitation on the lower limit, but 5 nm is preferred.

[0158] The average diameter of the small-diameter pores is calculated as follows: Using a FE-SEM at 150,000x magnification, observe N=4 images of the anodic oxide film surface. From the four images obtained, arbitrarily select 50 micropores (small-diameter pores) within a range of 400nm × 600nm and measure their diameters, then calculate the arithmetic mean. Alternatively, if the large-diameter pores are deep, the upper part of the anodic oxide film (the area containing the large-diameter pores) can be cut as needed (e.g., by argon gas cutting). Then, observe the anodic oxide film surface using the aforementioned FE-SEM and calculate the average diameter of the small-diameter pores.

[0159] Additionally, when the shape of a small-diameter aperture is not circular, the equivalent diameter of a circle is used. The "equivalent diameter of a circle" refers to the diameter of a circle when the shape of the aperture is assumed to be a circle with a projected area equal to the projected area of ​​the aperture.

[0160] The bottom of the small-diameter hole is preferably located at a position extending 20 nm to 2,000 nm further along the depth direction from the position communicating with the large-diameter hole (corresponding to the depth A mentioned above). In other words, the small-diameter hole is a hole extending further along the depth direction (thickness direction) from the position communicating with the large-diameter hole, and the depth of the small-diameter hole is preferably 20 nm to 2,000 nm, more preferably 100 nm to 1,500 nm, and particularly preferably 200 nm to 1,000 nm.

[0161] In addition, regarding the aforementioned depth, a cross-sectional photograph of the anodized film was taken (150,000x magnification), the depth of more than 25 small-diameter holes was measured, and the result was calculated as an arithmetic mean.

[0162] The shape of the small-diameter orifice is not particularly limited. For example, it can be a generally straight tube (generally cylindrical) or a conical shape in which the diameter decreases in the depth direction. It is preferably a generally straight tube. Furthermore, the shape of the bottom of the small-diameter orifice is not particularly limited. It can be curved (convex) or flat.

[0163] There is no particular limitation on the inner diameter of the small-diameter orifice, but it can be the same size as the diameter of the connected position, or it can be smaller or larger than the aforementioned diameter. In addition, the inner diameter of the small-diameter orifice can usually differ from the diameter of the opening by about 1 nm to 10 nm.

[0164] The ratio of the average diameter of the large-diameter hole at the surface of the anodic oxide film to the average diameter of the small-diameter hole at the connecting position, (average diameter of the large-diameter hole at the surface of the anodic oxide film) / (average diameter of the small-diameter hole at the connecting position) is preferably 1.1 to 13, more preferably 2.5 to 6.5.

[0165] Furthermore, the ratio of the depth of the large-diameter hole to the depth of the small-diameter hole, (depth of the large-diameter hole) / (depth of the small-diameter hole), is preferably 0.005 to 50, more preferably 0.025 to 40.

[0166] Furthermore, the shape of the micropore is approximately straight tubular (approximately cylindrical), with the diameter of the micropore remaining almost unchanged in the depth direction (thickness direction), but it can also be conical, with the diameter continuously increasing in the depth direction (thickness direction). Alternatively, it can be a shape with the diameter increasing discontinuously in the depth direction (thickness direction).

[0167] As a type of micropore whose diameter increases discontinuously toward the depth direction (thickness direction), an example of a micropore can be formed by a small-diameter pore portion extending along the depth direction from the surface of the anodic oxide film and a large-diameter pore portion communicating with the bottom of the small-diameter pore portion and extending along the depth direction from the communication position.

[0168] Specifically, the micropores preferably consist of a small-diameter pore extending 10 nm to 1,000 nm from the surface of the anodic oxide film along the depth direction and a large-diameter pore that communicates with the bottom of the small-diameter pore and extends further along the depth direction from the communication position by 20 to 2,000 nm.

[0169] -Small Diameter Orifice-

[0170] The average diameter (average opening diameter) of the small-diameter orifice at the surface of the anodic oxide film is not particularly limited, but it is preferably 35 nm or less, more preferably 25 nm or less, and especially preferably 20 nm or less. There is no particular limitation on the lower limit, but 15 nm is preferred.

[0171] The average diameter of the small-diameter pores is calculated as follows: N=4 images of the anodic oxide film surface are observed using a field emission scanning electron microscope (FE-SEM) with a magnification of 150,000x. From the four images obtained, 50 micropores (small-diameter pores) within the range of 400nm×600nm are randomly selected and their diameters are measured. The arithmetic mean is then calculated.

[0172] Additionally, when the shape of a small-diameter aperture is not circular, the equivalent diameter of a circle is used. The "equivalent diameter of a circle" refers to the diameter of a circle when the shape of the aperture is assumed to be a circle with a projected area equal to the projected area of ​​the aperture.

[0173] The bottom of the small-diameter orifice is preferably located at a depth of 70 nm to 1,000 nm (hereinafter also referred to as depth A') from the surface of the anodic oxide film. That is, the small-diameter orifice is preferably an orifice extending 70 nm to 1,000 nm from the surface of the anodic oxide film along the depth direction (thickness direction).

[0174] In addition, regarding the aforementioned depth, a cross-sectional photograph of the anodized film was taken (150,000x magnification), the depth of more than 25 large-diameter holes was measured, and the result was calculated as an arithmetic mean.

[0175] The shape of the small-diameter orifice is not particularly limited. For example, it can be a generally straight tube (generally cylindrical) or a conical shape in which the diameter increases in the depth direction (thickness direction). It is preferably a generally straight tube. Furthermore, the shape of the bottom of the small-diameter orifice is not particularly limited. It can be curved (convex) or flat.

[0176] There are no particular restrictions on the inner diameter of the small-diameter orifice, but it is preferable to have a diameter similar to or smaller than that of the opening. Additionally, the inner diameter of the small-diameter orifice can differ from the diameter of the opening by approximately 1 nm to 10 nm.

[0177] -Large diameter hole-

[0178] A large-diameter hole is a hole that connects to the bottom of a small-diameter hole and extends further along the depth direction (thickness direction) from the connection point. A single large-diameter hole typically consists of two or more small-diameter holes connected to the bottom of a single large-diameter hole.

[0179] The average diameter of the large-diameter hole at the connecting position is preferably 20nm to 400nm, more preferably 40nm to 300nm, even more preferably 50nm to 200nm, and especially preferably 50nm to 100nm.

[0180] The average diameter of the large-diameter pores is calculated as follows: Using a FE-SEM with a magnification of 150,000x, observe N=4 images of the anodic oxide film surface. From the four images obtained, arbitrarily select 50 micropores (large-diameter pores) within a range of 400nm × 600nm and measure their diameters, then calculate the arithmetic mean. Alternatively, if the small-diameter pores are deep, the upper part of the anodic oxide film (the area containing the small-diameter pores) can be cut as needed (e.g., by argon gas cutting). Then, observe the anodic oxide film surface using the aforementioned FE-SEM and calculate the average diameter of the large-diameter pores.

[0181] Additionally, when the shape of a large-diameter hole 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.

[0182] The bottom of the large-diameter hole is preferably located at a position extending 20 nm to 2,000 nm further along the depth direction from the position communicating with the small-diameter hole (corresponding to the depth A' mentioned above). In other words, the large-diameter hole is a hole extending further along the depth direction (thickness direction) from the position communicating with the small-diameter hole, and the depth of the large-diameter hole is preferably 20 nm to 2,000 nm, more preferably 100 nm to 1,500 nm, and particularly preferably 200 nm to 1,000 nm.

[0183] In addition, regarding the aforementioned depth, a cross-sectional photograph of the anodized film was taken (150,000x magnification), the depth of more than 25 large-diameter holes was measured, and the result was calculated as an arithmetic mean.

[0184] The shape of the large-diameter hole is not particularly limited. For example, it can be a generally straight tube (generally cylindrical) or a conical shape in which the diameter decreases in the depth direction. It is preferably a generally straight tube. Furthermore, the shape of the bottom of the large-diameter hole is not particularly limited. It can be curved (convex) or flat.

[0185] There are no particular restrictions on the inner diameter of the large-diameter hole, but it can be the same size as the diameter of the connecting position, or it can be smaller or larger than the aforementioned diameter. In addition, the inner diameter of the large-diameter hole can usually differ from the diameter of the opening by about 1 nm to 10 nm.

[0186] The aforementioned support has an anodic oxide film.

[0187] The aforementioned anodic oxide film preferably has the following characteristics sequentially from the surface of the anodic oxide film towards its depth:

[0188] The upper layer, with a thickness of 30–500 nm, has micropores with an average diameter of 20–100 nm;

[0189] An intermediate layer with a thickness of 100–300 nm has micropores with an average diameter of 1 / 2 to 5 times the average diameter of the micropores in the upper layer described above; and

[0190] The lower layer, with a thickness of 300–2000 nm, has micropores with an average diameter of less than 15 nm.

[0191] In machine-developable lithographic printing plates, high brightness at the surface of the anodized film on the support (the surface on the side where the image recording layer is formed) is useful from the viewpoint of improving the visual recognition of the image in the original plate.

[0192] In the lithographic printing process, a plate inspection is typically performed to confirm whether the image recording meets the intended purpose before the printing plate is mounted on the printing press. In on-machine developing lithographic printing plates, image verification is required during the image exposure stage; therefore, a mechanism that generates the so-called printed image is used in the image exposure unit.

[0193] As a method for quantitatively evaluating the visibility (visual recognizability) of the image portion of an on-machine developing lithographic printing plate original after image exposure, one approach is to measure the brightness of the exposed and unexposed portions of the image and calculate the difference between them. Here, brightness can be measured using the value of brightness L* in the CIEL*a*b* color system, and the measurement can be performed using a colorimeter (manufactured by SpectroEye, X-Rite Inc.). The greater the difference between the brightness of the exposed and unexposed portions of the image obtained by measurement, the easier it is to see the image portion.

[0194] It has been determined that a high value of the lightness L* in the CIEL*a*b* color system of the anodized film surface is effective in increasing the lightness difference between the exposed and unexposed areas of an image. Specifically, the preferred value of the lightness L* is 60 to 100.

[0195] The support having an anodic oxide film may, as needed, have a back coating on the side opposite to the side where a structural layer containing a hydroxy acid compound having two or more hydroxyl groups is formed, 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.

[0196] (Manufacturing of aluminum support with anodized film)

[0197] As an example of a support, a method for manufacturing an aluminum support having an anodized film is described.

[0198] Aluminum supports with anodized film can be manufactured using known methods. The method for manufacturing aluminum supports with anodized film is not particularly limited. A preferred method for manufacturing aluminum supports with anodized film includes the following steps: a process of roughening an aluminum plate (roughening process); a process of anodizing the roughened aluminum plate (anodizing process); and a process of contacting the aluminum plate having the 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 (pore enlargement process).

[0199] The following is a detailed description of each process.

[0200] <Roughening Process>

[0201] The roughening process is a process of applying an electrochemical roughening treatment to the surface of the aluminum plate. The roughening 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 unnecessary.

[0202] Regarding roughening treatment, electrochemical roughening treatment may be performed alone, or it may be performed in combination with at least one of electrochemical roughening treatment, mechanical roughening treatment, and chemical roughening treatment.

[0203] In the case of a combination of mechanical roughening treatment and electrochemical roughening treatment, it is preferable to perform electrochemical roughening treatment after mechanical roughening treatment.

[0204] Electrochemical roughening treatment is preferably carried out in an aqueous solution of nitric acid or hydrochloric acid.

[0205] Mechanical roughening treatment is usually carried out with the aim of setting the surface roughness Ra of the aluminum plate to 0.35 to 1.0 μm.

[0206] There are no particular limitations on the various conditions for mechanical roughening treatment, but it can be carried out, for example, according to the methods described in Japanese Patent Publication No. 50-40047. Mechanical roughening treatment can be carried out by brushing with a pumice suspension or by transfer printing.

[0207] Furthermore, there are no particular limitations on the chemical roughening treatment; it can be carried out using known methods.

[0208] Preferably, the following chemical etching process is performed after mechanical roughening.

[0209] The chemical etching process performed after mechanical roughening is carried out for the following purposes: to smooth the uneven edges of the aluminum plate surface, to prevent ink from catching on during printing, thereby improving the stain resistance of the lithographic printing plate, and to remove useless substances such as abrasive particles remaining on the surface.

[0210] As a chemical etching process, etching using acids and etching using alkalis are known, but chemical etching using alkaline solutions (hereinafter also referred to as "alkali etching") is a method that is particularly superior in terms of etching efficiency.

[0211] There are no particular limitations on the alkaline agents used in alkaline solutions, but preferred examples include sodium hydroxide, potassium hydroxide, sodium metasilicate, sodium carbonate, sodium aluminate, and sodium gluconate.

[0212] The alkaline solution may contain aluminum ions. The concentration of the alkaline agent in the alkaline solution is preferably 0.01% by mass or more, more preferably 3% by mass or more, or preferably 30% by mass or less, more preferably 25% by mass or less.

[0213] Furthermore, the temperature of the alkaline solution is preferably above room temperature, more preferably above 30°C, and preferably below 80°C, more preferably below 75°C.

[0214] The preferred etching amount is 0.01 g / m. 2 The above, more preferably 0.05 g / m 2 The above or preferred value is 30g / m 2 The following is more preferably 20g / m 2 the following.

[0215] Corresponding to the etching amount, the processing time is preferably 2 to 5 minutes, and more preferably 2 to 10 seconds from the viewpoint of improving productivity.

[0216] When alkaline etching is performed after mechanical roughening, chemical etching (hereinafter also referred to as "decontamination treatment") is preferably performed using a low-temperature acidic solution to remove the products generated by alkaline etching.

[0217] The acid used in the acidic solution is not particularly limited, but examples include sulfuric acid, nitric acid, and hydrochloric acid. The concentration of the acidic solution is preferably 1 to 50% by mass. The temperature of the acidic solution is preferably 20 to 80°C. If the concentration and temperature of the acidic solution are within this range, the resistance to spot contamination in offset printing plates using aluminum supports is further improved.

[0218] The following examples illustrate preferred methods for roughening processes.

[0219] -Method SA-

[0220] The processes shown in (1) to (8) are performed sequentially.

[0221] (1) Chemical etching treatment using alkaline aqueous solution (first alkaline etching treatment)

[0222] (2) Chemical etching treatment using acidic aqueous solution (first decontamination treatment) was used.

[0223] (3) Electrochemical roughening treatment using an aqueous solution based on nitric acid (first electrochemical roughening treatment) was used.

[0224] (4) Chemical etching treatment using alkaline aqueous solution (second alkaline etching treatment)

[0225] (5) Chemical etching treatment using acidic aqueous solution (second decontamination treatment) was used.

[0226] (6) Electrochemical roughening treatment using an aqueous solution mainly composed of hydrochloric acid (second electrochemical roughening treatment) was used.

[0227] (7) Chemical etching treatment using alkaline aqueous solution (third alkaline etching treatment)

[0228] (8) Chemical etching treatment using acidic aqueous solution (third cleaning treatment)

[0229] -Method SB-

[0230] The processes shown in (11) to (15) are performed sequentially.

[0231] (11) Chemical etching treatment using alkaline aqueous solution (4th alkaline etching treatment) was used.

[0232] (12) Chemical etching treatment using acidic aqueous solution (4th decontamination treatment) was used.

[0233] (13) Electrochemical roughening treatment using an aqueous solution mainly composed of hydrochloric acid (3rd electrochemical roughening treatment) was used.

[0234] (14) Chemical etching treatment using alkaline aqueous solution (5th alkaline etching treatment)

[0235] (15) Chemical etching treatment using acidic aqueous solution (5th cleaning treatment) was used.

[0236] As needed, mechanical roughening treatment may be performed before the treatment of (1) in method SA or before the treatment of (11) in method SB.

[0237] The preferred dissolution rate of the aluminum plate in the first and fourth alkaline etching treatments is 0.5 g / m³. 2 ~30g / m 2 More preferably 1.0 g / m 2 ~20g / m 2 .

[0238] As an example of the aqueous solution mainly composed of nitric acid used in the first electrochemical roughening treatment in Method SA, examples include aqueous solutions used in electrochemical roughening treatments that employ direct current or alternating current. For instance, an aqueous solution obtained by adding aluminum nitrate, sodium nitrate, or ammonium nitrate to an aqueous solution of nitric acid at a concentration of 1 g / L to 100 g / L can be cited.

[0239] The hydrochloric acid-based aqueous solution used in the second electrochemical roughening treatment in Method SA and the third electrochemical roughening treatment in Method SB can be exemplified by aqueous solutions used in electrochemical roughening treatments employing direct current or alternating current. For example, an aqueous solution obtained by adding 0 g / L to 30 g / L of sulfuric acid to a hydrochloric acid aqueous solution of 1 g / L to 100 g / L can be cited. Furthermore, nitrate ions such as aluminum nitrate, sodium nitrate, or ammonium nitrate, and chloride ions such as aluminum chloride, sodium chloride, or ammonium chloride can be further added to this aqueous solution.

[0240] The AC power waveform for electrochemical roughening treatment can use sine waves, rectangular waves, trapezoidal waves, or triangular waves, etc. The frequency is preferably 0.1Hz to 250Hz.

[0241] Figure 1 This is a chart showing an example of an alternating current waveform used in electrochemical roughening treatment.

[0242] exist Figure 1In this context, ta represents the anode reaction time, tc represents the cathode reaction time, tp represents the time it takes for the current to reach its peak value from 0, Ia represents the peak current on the anode circulation side, and Ic represents the peak current on the cathode circulation side. In the trapezoidal wave, the time tp for the current to reach its peak value from 0 is preferably 1 msec to 10 msec. The preferred conditions for one cycle of AC current used for electrochemical roughening treatment are: the ratio of the anode reaction time ta to the cathode reaction time tc (tc / ta) of the aluminum plate is 1 to 20; the ratio of the charge Qc when the aluminum plate is the anode to the charge Qa when the anode is Qc (Qc / Qa) is 0.3 to 20; and the anode reaction time ta is in the range of 5 msec to 1,000 msec. Regarding current density, the peak current on both the anode circulation side (Ia) and the cathode circulation side (Ic) of the trapezoidal wave are preferably 10 to 200 A / dm². 2 The Ic / Ia ratio is preferably 0.3 to 20. The total charge participating in the anodic reaction of the aluminum plate at the end of the electrochemical roughening treatment is preferably 25 C / dm². 2 ~1,000C / dm 2 .

[0243] In electrochemical roughening treatment using alternating current, it is possible to use Figure 2 The apparatus shown.

[0244] Figure 2 This is a side view showing an example of a radial unit in an electrochemical roughening process using alternating current.

[0245] exist Figure 2 In this configuration, 50 is the main electrolytic cell, 51 is the AC power supply, 52 is the radial drum roller, 53a and 53b are the main electrodes, 54 is the electrolyte supply port, 55 is the electrolyte, 56 is the slit, 57 is the electrolyte channel, 58 is the auxiliary anode, 60 is the auxiliary anode tank, and W is the aluminum plate. When using two or more electrolytic cells, the electrolysis conditions can be the same or different.

[0246] An aluminum plate W is rolled onto a radial drum roller 52, which is immersed in the main electrolytic cell 50, and electrolyzed during transport via main electrodes 53a and 53b connected to an AC power supply 51. Electrolyte 55 is supplied from the electrolyte supply port 54 through a slit 56 to the electrolyte channel 57 between the radial drum roller 52 and the main electrodes 53a and 53b. The aluminum plate W, after being treated in the main electrolytic cell 50, is then electrolyzed in an auxiliary anode cell 60. In this auxiliary anode cell 60, an auxiliary anode 58 is positioned opposite the aluminum plate W, and electrolyte 55 is supplied in a manner that flows through the space between the auxiliary anode 58 and the aluminum plate W.

[0247] In terms of facilitating the manufacture of the prescribed lithographic printing plate original, the amount of aluminum plate dissolved in the second alkaline etching process is preferably 1.0 g / m². 2~20g / m 2 More preferably 2.0 g / m 2 ~10g / m 2 .

[0248] In terms of facilitating the manufacture of the prescribed lithographic printing plate original, the amount of aluminum plate dissolved in the third and fifth alkaline etching processes is preferably 0.01 g / m². 2 ~0.8g / m 2 More preferably 0.05 g / m 2 ~0.3g / m 2 .

[0249] In chemical etching processes (decontamination processes 1 to 5) using acidic aqueous solutions, it is preferable to use an acidic aqueous solution containing phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixture of two or more of these acids.

[0250] The concentration of acid in the acidic aqueous solution is preferably 0.5% to 60% by mass.

[0251] <Anodizing Process>

[0252] The anodizing process is a process of forming an aluminum oxide film on the surface of an aluminum plate that has undergone the roughening treatment described above. Through anodizing, a microporous aluminum anodized film is formed on the surface of the aluminum plate.

[0253] Anodizing can be performed by appropriately setting manufacturing conditions, taking into account the desired shape of the micropores, based on methods known in the field.

[0254] In the anodizing process, aqueous solutions of sulfuric acid, phosphoric acid, and oxalic acid can be primarily used as the electrolyte. Depending on the circumstances, aqueous or non-aqueous solutions of chromic acid, sulfamic acid, benzenesulfonic acid, or combinations of two or more of these can also be used. If a direct current or alternating current is applied to the aluminum plate in the electrolyte, an anodized film can be formed on the surface of the aluminum plate. Aluminum ions can be included in the electrolyte. The content of aluminum ions is not particularly limited, but is preferably 1–10 g / L.

[0255] The conditions for anodizing can be appropriately set according to the electrolyte used, but typically the electrolyte concentration is 1–80% by mass (preferably 5–20% by mass), the liquid temperature is 5–70°C (preferably 10–60°C), and the current density is 0.5–60 A / dm³. 2 (Preferred value: 5-50 A / dm) 2 The range of voltage from 1 to 100V (preferably 5 to 50V) and electrolysis time from 1 to 100 seconds (preferably 5 to 60 seconds) is appropriate.

[0256] The method of anodizing in sulfuric acid with a high current density, as described in British Patent No. 1,412,768, is a preferred example of anodizing treatment.

[0257] Anodizing can be performed multiple times. One or more of the following conditions can be changed in each anodizing process: electrolyte type, concentration, temperature, current density, voltage, and electrolysis time. When anodizing is performed twice, the initial anodizing process is sometimes referred to as the first anodizing process, and the second anodizing process as the second anodizing process. By performing the first and second anodizing processes, anodized films with different shapes can be formed, thereby providing offset printing plate originals with excellent printing performance.

[0258] Alternatively, the following hole-expansion treatment can be performed after anodizing, followed by another anodizing treatment. In this case, the process involves a first anodizing treatment, a hole-expansion treatment, and a second anodizing treatment.

[0259] By using the methods described above for the first anodizing treatment, the pore-enlarging treatment, and the second anodizing treatment, it is possible to form a micropore consisting of a large-diameter pore extending from the surface of the aforementioned anodized film along the depth direction and a small-diameter pore communicating with the bottom of the large-diameter pore and extending from the communication position along the depth direction.

[0260] <Bore Reaming Process>

[0261] The pore enlargement process is a process that increases the diameter (pore size) of the micropores present in the anodic oxide film formed by the above-mentioned anodizing process (pore size enlargement process). Through this pore enlargement process, the diameter of the micropores is enlarged, forming an anodic oxide film with micropores having a larger average diameter.

[0262] 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. The contact method is not particularly limited; examples include immersion and spraying. Immersion is preferred.

[0263] When using an alkaline aqueous solution in the hole-expanding process, it is preferable to use at least one alkaline aqueous solution selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.1–5% by mass. It is appropriate to adjust the pH of the alkaline aqueous solution to 11–13 and contact the aluminum plate with the alkaline aqueous solution at 10–70°C (preferably 20–50°C) for 1–300 seconds (preferably 1–50 seconds). In this case, the alkaline treatment solution may contain metal salts of polybasic weak acids such as carbonates, borates, and phosphates.

[0264] When using an acid-water solution in the hole-expanding process, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, or hydrochloric acid, or a mixture thereof. The concentration of the acid-water solution is preferably 1 to 80% by mass, more preferably 5 to 50% by mass. It is appropriate to contact the aluminum plate with the acid-water solution for 1 to 300 seconds (preferably 1 to 150 seconds) at a solution temperature of 5 to 70°C (preferably 10 to 60°C).

[0265] Aluminum ions can be included in alkaline or acidic aqueous solutions. The content of aluminum ions is not particularly limited, but is preferably 1–10 g / L.

[0266] A method for manufacturing an aluminum support having an anodized film may include a hydrophilication treatment step after the aforementioned hole-expanding treatment step. In the hydrophilication treatment, the known methods described in paragraphs 0109 to 0114 of Japanese Patent Application Publication No. 2005-254638 can be used.

[0267] The hydrophilization treatment is preferably carried out by immersion in an aqueous solution of alkali metal silicates such as sodium silicate or potassium silicate, or by coating a hydrophilic vinyl polymer or hydrophilic compound to form a hydrophilic primer.

[0268] The hydrophilization treatment using aqueous solutions of alkali metal silicates such as sodium silicate and potassium silicate can be carried out according to the methods and steps described in U.S. Patent No. 2,714,066 and U.S. Patent No. 3,181,461.

[0269] [Image recording layer]

[0270] The aforementioned image recording layer contains a chromogenic compound having groups that are cleaved by infrared exposure, a polymerization initiator, a polymerization compound, and a hydrogen-donating compound.

[0271] [Chromatophoretic compounds containing groups that are cleaved upon infrared exposure]

[0272] The image recording layer in the lithographic printing plate original involved in this invention contains a chromogenic compound (hereinafter also referred to as "chromogenic compound") having groups that are cleaved by infrared exposure.

[0273] The chromogenic compound contained in the image recording layer is preferably an infrared absorber that has the function of absorbing infrared light and decomposing it to produce color through infrared exposure.

[0274] Decomposition refers to the cleavage of functional groups through infrared exposure.

[0275] Here, "color development" refers to the fact that before infrared exposure, there is almost no absorption in the visible light region (wavelength region above 400nm and below 750nm), but absorption occurs in the visible light region after infrared exposure. It also includes the absorption in the lower wavelength region than the visible light region being lengthened in the visible light region.

[0276] Hereinafter, compounds that exhibit color by absorbing and decomposing infrared radiation through infrared exposure are also referred to as "chromophores of chromophores".

[0277] Furthermore, the chromogenic compound preferably has the function of absorbing infrared radiation through infrared exposure and converting the absorbed infrared radiation into heat.

[0278] The aforementioned decomposable infrared absorber only needs to absorb at least a portion of the light in the infrared wavelength region (wavelength 750nm to 1mm) and decompose it, but it is preferred to be an infrared absorber with extremely high absorption in the wavelength region of 750nm to 1,400nm.

[0279] The aforementioned chromophores are preferably infrared absorbers that decompose through thermal or electron transfer caused by infrared exposure, or both. More preferably, they are infrared absorbers that decompose through electron transfer caused by infrared exposure. Here, "decomposition through electron transfer" means that in infrared absorbers decomposable by infrared exposure, electrons excited from the HOMO (highest occupied molecular orbital) to LUMO (lowest unoccupied molecular orbital) are transferred within the molecule to electron-accepting groups (groups with potentials close to the LUMO), resulting in decomposition.

[0280] From the viewpoint of color development and UV resistance of the obtained lithographic printing plate, anthocyanin pigments that decompose upon infrared exposure are preferred as the aforementioned color-developing compounds.

[0281] From the viewpoint of color development and UV resistance of the obtained lithographic printing plate, the color-developing compound is more preferably anthocyanin pigment represented by the following formula 1.

[0282] [Chemical Formula 7]

[0283]

[0284] In Equation 1, R 1 Indicates that R is obtained through infrared exposure. 1 -L bond cleavage group, R 11 ~R 18 Each of these can independently represent a hydrogen atom, a halogen atom, -Ra, -ORb, -SRc, or -NRdRe, where Ra to Re can independently represent hydrocarbon groups, A1, A2, and multiple R groups. 11 ~R 18They 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 number 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.

[0285] If the anthocyanin represented by Equation 1 is exposed to infrared light, then R 1 -L bond breaks down, L becomes =O, =S, or =NR. 10 This leads to the formation of the chromophore of the chromophore compound. R 1 They detach and form free radicals or ions. These contribute to the polymerization of polymerizable compounds contained in the image recording layer.

[0286] In Equation 1, R 11 ~R 18 Preferably, they are hydrogen atoms, -Ra, -ORb, -SRc, or -NRdRe, respectively.

[0287] The hydrocarbon group in Ra to Re 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. The above-mentioned hydrocarbon group can be linear, branched, or cyclic.

[0288] R in Equation 1 11 ~R 14 Each of the components is preferably a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom or an alkyl group, and even more preferably a hydrogen atom.

[0289] Furthermore, R is bonded to the carbon atom bonded to the carbon atom bonded to L. 11 and R 13 Preferably, the two are linked together to form a ring. The ring formed is preferably a 5-membered ring or a 6-membered ring, more preferably a 5-membered ring.

[0290] R is preferred when bonded to the carbon atom bonded to A1+. 12 and R bonded to the carbon atom bonded to A2 14 respectively with R 15 and R 17 They connect to form a ring.

[0291] R in Equation 1 15 Preferably, it is a hydrocarbon group. Furthermore, R is preferred.15 R bonded to the carbon atom bonded to A1+ 12 The rings are linked together to form a ring. The rings formed are preferably indolonium rings, pyranium rings, thiopyranium rings, benzoxazolinium rings, or benzimidazolinium rings, and from the viewpoint of color development, indolonium rings are more preferred.

[0292] R in Equation 1 17 Preferably, it is a hydrocarbon group. Furthermore, R is preferred. 17 R bonded to the carbon atom of A2 14 The rings are linked together to form a ring. The rings formed are preferably indole rings, pyran rings, thiopyran rings, benzoxazole rings, or benzimidazole rings, and indole rings are more preferred from the viewpoint of color development.

[0293] R in Equation 1 15 and R 17 Preferably, the same groups are used, and if they each form a ring, it is preferable that they form the same ring.

[0294] R in Equation 1 16 and R 18 Preferably, they are the same group.

[0295] Furthermore, from the viewpoint of improving the water solubility of the compound represented by Formula 1, R 16 and R 18 Each and every one of the alkyl groups is preferably an alkyl group having a (poly)oxyalkylene group or an alkyl group having an anionic structure, more preferably an alkoxyalkyl group, an alkyl group having a carboxylic acid ester group or a sulfonate group, and even more preferably an alkyl group having a sulfonate group at the end. As the above-mentioned alkyl group, it is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms.

[0296] The counter cation of the above anionic structure can be R in Formula 1. 1 -L can contain cations or Al+, and can also be alkali metal cations or alkaline earth metal cations.

[0297] The counter cation of the above sulfonate group can be R in Formula 1. 1 -L can contain cations or Al+, and can also be alkali metal cations or alkaline earth metal cations.

[0298] Furthermore, from the perspective of extending the maximum absorption wavelength of the compound represented by Formula 1, and considering the color development and brush resistance in offset printing plates, R 16 and R 18Each of the components is preferably an alkyl group or an alkyl group having an aromatic ring. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably methyl or ethyl. The alkyl group having an aromatic ring is preferably an alkyl group having an aromatic ring at the end, more preferably 2-phenylethyl, 2-naphthylethyl, or 2-(9-anthrayl)ethyl.

[0299] n in Equation 1 11 and n 12 Preferably, it is an integer from 0 to 5, more preferably an integer from 1 to 3, even more preferably 1 or 2, and especially preferably 2.

[0300] In Formula 1, A1 and A2 independently represent oxygen, sulfur, or nitrogen atoms, with nitrogen atoms being preferred.

[0301] In Formula 1, A1 and A2 are preferably the same atoms.

[0302] In Formula 1, Za represents the counter ion that neutralizes the charge. When representing the type of anion, examples include sulfonate ions, carboxylate ions, tetrafluoroborate ions, hexafluorophosphate ions, hexafluoroantimonate ions, p-toluenesulfonate ions, and perchlorate ions, with hexafluorophosphate ions or hexafluoroantimonate ions being preferred. When representing the type of cation, examples include alkali metal ions, alkaline earth metal ions, ammonium ions, pyridinium ions, and sulfonium ions, with sodium ions, potassium ions, ammonium ions, pyridinium ions, or sulfonium ions being preferred, and sodium ions, potassium ions, or ammonium ions being more preferred.

[0303] R 11 ~R 18 and R 1 -L can have anionic or cationic structures, if R 11 ~R 18 and R 1 If all -L groups are electrically neutral, then Za is a monovalent counter anion. For example, in R... 11 ~R 18 and R 1 When -L has two or more anionic structures, Za can also be a counter cation.

[0304] Furthermore, if the anthocyanin represented by Formula 1 has an electroneutrally neutral structure in the overall compound, then Za does not exist.

[0305] In Equation 1, regarding R 1 The R value represents the result of infrared exposure. 1 Groups that break down -L bonds will be described in detail later.

[0306] From the viewpoint of color development and UV resistance of the obtained lithographic printing plate, the anthocyanin pigment decomposed by infrared exposure is more preferably the anthocyanin pigment represented by the following formula 2.

[0307] [Chemical Formula 8]

[0308]

[0309] In Equation 2, R 1 Indicates that R is obtained through infrared exposure. 1 -L bond cleavage group, R 2 and R 3 Each can be independently represented by a hydrogen atom or an alkyl group, R 2 and R 3 They can be connected to form a ring, Ar 1 and Ar 2 Each group independently represents a group that forms a benzene ring or a naphthalene ring, Y 1 and Y 2 Each of the oxygen atom, sulfur atom, and -NR atom can be represented independently. 0 -or dialkylmethylene, R 0 R represents a hydrogen atom, alkyl group, or aryl group. 4 and R 5 Each can independently represent an aliphatic hydrocarbon group, a -CO2M group, or a -PO3M2 group, where M represents a hydrogen atom, a Na atom, a K atom, or an onium group, and R... 6 ~R 9 Each can be used independently to represent a hydrogen atom or an alkyl group, and L can represent 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.

[0310] R 4 R 5 The aliphatic hydrocarbon group is not particularly limited, but alkyl groups are preferred.

[0311] In Equation 2, R 2 ~R 9 and R 0 The alkyl group 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. The alkyl group can be straight-chain, branched, or cyclic.

[0312] 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.

[0313] The alkyl group is preferably methyl, ethyl, propyl or butyl.

[0314] The aforementioned alkyl groups may have substituents. Examples of substituents include alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, carboxylic acid ester, sulfonyl, sulfonate, alkoxycarbonyl, aryloxycarbonyl, and groups formed by combining these.

[0315] R 0 The aryl group 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.

[0316] The aforementioned aryl group may have substituents. Examples of substituents include alkyl, alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, carboxylic acid ester, sulfonyl, sulfonate, alkoxycarbonyl, aryloxycarbonyl, and groups formed by combining these.

[0317] Specifically, examples include phenyl, naphthyl, p-tolyl, p-chlorophenyl, p-fluorophenyl, p-methoxyphenyl, p-dimethylaminophenyl, p-methylthiophenyl, and p-phenylthiophenyl.

[0318] Among the aryl groups, phenyl, p-methoxyphenyl, p-dimethylaminophenyl, or naphthyl are preferred.

[0319] Preferred R 2 and R 3 They connect to form a ring.

[0320] In R 2 and R 3 When a ring is formed by connecting links, a 5-membered ring or a 6-membered ring is preferred, and a 5-membered ring is especially preferred.

[0321] Y 1 and Y 2 Each of the oxygen atom, sulfur atom, and -NR atom can be represented independently. 0 -or dialkylmethylene, preferably -NR 0 - or dialkylmethylene, more preferably dialkylmethylene.

[0322] R 0 It represents a hydrogen atom, an alkyl group, or an aryl group, preferably an alkyl group.

[0323] R 4 Or R 5 The alkyl group represented can be a substituted alkyl group. As R 4 Or R 5 The substituted alkyl group can be any one of the groups represented by formulas (a1) to (a5) below.

[0324] [Chemical Formula 9]

[0325]

[0326] -R W6 -R W7 (a5)

[0327] 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 R W6 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, a Na atom, a K atom, or an ononium group.

[0328] R W7 Indicates aryl. As an aryl group, it is related to R. 0 The aryl groups are the same, and the preferred range is also the same.

[0329] In equation (a1), as a result of R W0 Specific examples of the alkylene group may include ethylene, n-propylene, isopropylene, n-butylene, isobutylene, n-pentylene, isopentylene, n-hexylene, isohexylene, etc., with ethylene, n-propylene, isopropylene, n-butylene being the most preferred, and n-propylene being particularly preferred.

[0330] n W1 Preferably 1 to 10, more preferably 1 to 5, and especially preferably 1 to 3.

[0331] As 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., preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, more preferably methyl, ethyl, and especially preferably methyl.

[0332] R W5The alkyl group represented by R W1 The alkyl group represented is the same, and the preferred method is also the same as R. W1 The preferred method for the alkyl group is the same.

[0333] Specific examples of the groups represented by formula (a1) are shown below, but the invention is not limited to these. In the following structural formulas, Me represents methyl, Et represents ethyl, and * represents a bonding site.

[0334] [Chemical Formula 10]

[0335]

[0336] In equations (a2) to (a5), R is used as... W2 ~R W4 R W6 Specific examples of the alkylene group may 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, n-butylene, and especially preferably ethylene and n-propylene.

[0337] In equation (a3), there are two M values ​​that can be the same or different.

[0338] In formulas (a2) to (a4), examples of ononium groups represented by M include ammonium, iodonium, phosphonium, and sulfonium.

[0339] Among the groups represented by formulas (a1) to (a5), the groups represented by formula (a1) or (a4) are preferred.

[0340] In Equation 2, R 4 and R 5 Each is preferably an unsubstituted alkyl group. R is preferred. 4 and R 5 They are the same group.

[0341] R 6 ~R 9 Each can be represented independently as a hydrogen atom or an alkyl group, preferably a hydrogen atom.

[0342] Ar 1 and Ar 2 Each group independently represents a group forming a benzene ring or a naphthalene ring. The aforementioned benzene ring and naphthalene ring may have substituents. Examples of substituents include alkyl, alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, carboxylic acid ester, sulfonyl, sulfonate, alkoxycarbonyl, aryloxycarbonyl, acyloxy, phosphonic acid, and groups formed by combining these. Alkyl groups are preferred as substituents.

[0343] Furthermore, from the viewpoint of extending the maximum absorption wavelength of the compound represented by Formula 2, and improving color development and the brush resistance of lithographic printing plates, Ar 1 and Ar 2 Each group is preferably a group that forms a naphthalene ring or a benzene ring having alkyl or alkoxy groups as substituents, more preferably a group that forms a naphthalene ring or a benzene ring having alkoxy groups as substituents, and especially preferably a group that forms a naphthalene ring or a benzene ring having methoxy groups as substituents.

[0344] In Equation 2, Ar 1 Or Ar 2 Preferably, it is a group that forms the group represented by the following formula (b1).

[0345] [Chemical Formula 11]

[0346]

[0347] In equation (b1), R 19 Indicates an alkyl group with 1 to 12 carbon atoms. n3 indicates an integer from 1 to 4. * indicates a bonding site.

[0348] Za represents a counterion used to neutralize the charge. The compound represented by Formula 2 has a corresponding ionic substituent in its structure, and Za is not required when neutralization of the charge is not needed. When Za represents the type of anion, examples include sulfonate ions, carboxylate ions, tetrafluoroborate ions, hexafluorophosphate ions, hexafluoroantimonate ions, p-toluenesulfonate ions, perchlorate ions, etc., preferably hexafluorophosphate ions or hexafluoroantimonate ions. When Za represents the type of cation, examples include alkali metal ions, alkaline earth metal ions, ammonium ions, pyridinium ions, or sulfonium ions, preferably sodium ions, potassium ions, ammonium ions, pyridinium ions, or sulfonium ions, more preferably sodium ions, potassium ions, or ammonium ions.

[0349] R 1 ~R 9 R 0 Ar 1 Ar 2 Y 1 and Y 2 It can have anionic or cationic structures, if R 1 ~R 9 R 0 Ar 1 Ar 2 Y 1 and Y 2 If all groups are electrically neutral, then Za is a monovalent counter anion. However, for example, in R... 1 ~R 9 R 0Ar 1 Ar 2 Y 1 and Y 2 When Za has two or more anionic structures, it can also become a counter cation.

[0350] In equations 1 and 2 above, regarding R 1 The R value represents the result of infrared exposure. 1 Groups that have undergone -L bond cleavage are described below.

[0351] When L is an oxygen atom in Equation 1 or Equation 2, from the point of view of colorimetry, R 1 Preferably, it is a group represented by any one of the following formulas (1-1) to (1-7), and more preferably, it is a group represented by any one of the following formulas (1-1) to (1-3).

[0352] [Chemical Formula 12]

[0353]

[0354] In equations (1-1) to (1-7), ● represents the bonding site with the oxygen atom represented by L in equation 1 or equation 2, and R 20 Each can independently represent a hydrogen atom, alkyl group, alkenyl group, aryl group, or -OR group. 24 -NR 25 R 26 or -SR 27 R 21 Each of the following can be independently represented by a hydrogen atom, alkyl group, or aryl group; R 22 Indicates aryl, -OR 24 -NR 25 R 26 -SR 27 -C(=O)R 28 -OC (=O)R 28 Or halogen atoms, R 23 Indicates aryl, alkenyl, alkoxy, or onnnyl, R 24 ~R 27 Each of the following can be independently represented by a hydrogen atom, alkyl group, or aryl group; R 28 Indicates alkyl, aryl, -OR 24 -NR 25 R 26 or -SR 27 Z 1 This refers to counterions used to neutralize charges.

[0355] R 20 R 21 and R 24 ~R 28The preferred method in the case of alkyl groups is the same as R. 2 ~R 9 and R 0 The preferred method for alkyl groups is the same.

[0356] R 20 and R 23 The number of carbon atoms in the alkenyl group is preferably 1 to 30, more preferably 1 to 15, and even more preferably 1 to 10.

[0357] R 20 ~R 28 Preferred method when it is aryl and R 0 The preferred method for aryl groups is the same.

[0358] From the perspective of color development, R in equation (1-1) 20 Preferably alkyl, alkenyl, aryl, or -OR 24 -NR 25 R 26 or -SR 27 More preferably alkyl, -OR 24 -NR 25 R 26 or -SR 27 More preferably alkyl or -OR 24 Especially preferred is -OR 24 .

[0359] Furthermore, R in equation (1-1) 20 When the alkyl group is an alkyl group, the alkyl group may be an alkyl group having an arylthio group, an alkyloxycarbonyl group or an arylsulfonyl group at the α position, or an alkyl group having an arylthio group or an alkyloxycarbonyl group at the α position.

[0360] In equation (1-1) R 20 For -OR 24 In the case of R 24 Preferably, it is an alkyl group, more preferably an alkyl group having 1 to 8 carbon atoms, and even more preferably isopropyl or tert-butyl, especially tert-butyl.

[0361] In equation (1-1) R 20 In the case of an alkenyl group, the alkenyl group can be an alkenyl group having an aryl or hydroxyaryl group.

[0362] From the perspective of color development, R in equation (1-2) 21 Hydrogen atoms are preferred.

[0363] Furthermore, from the perspective of color development, R in equation (1-2) 22 Preferred option is -C (=O) OR 24 -OC (=O) OR24 Or halogen atoms, more preferably -C (=O) OR 24 OR -OC (=O) 24 In equation (1-2), R 22 -C (=O) OR 24 OR -OC (=O) 24 In the case of R 24 Alkyl groups are preferred.

[0364] From the perspective of color development, R in equation (1-3) 21 Each is preferably a hydrogen atom or an alkyl group, and at least one R in formulas (1-3) is present. 21 More preferably, it is an alkyl group.

[0365] Furthermore, R 21 The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 3 to 10 carbon atoms.

[0366] In addition, R 21 The alkyl group is preferably an alkyl group having a branched or cyclic structure, more preferably isopropyl, cyclopentyl, cyclohexyl, or tert-butyl. Furthermore, R... 21 The alkyl group is preferably a secondary alkyl group or a tertiary alkyl group.

[0367] From the perspective of color development, R in equation (1-3) 23 Preferably, it is aryl, alkoxy, or onnyl, more preferably p-dimethylaminophenyl or pyridinium, and even more preferably pyridinium.

[0368] As R 23 Examples of onnnyl groups include pyridinium, ammonium, and sulfonium. Onnnyl groups may have substituents. Examples of substituents include alkyl, aryl, alkoxy, aryloxy, amino, alkylthio, arylthio, halogen, carboxyl, sulfonyl, alkoxycarbonyl, aryloxycarbonyl, and groups formed by combinations thereof, with alkyl, aryl, and groups formed by combinations thereof being preferred.

[0369] Preferably, it is pyridinium-based, more preferably N-alkyl-3-pyridinium-based, N-benzyl-3-pyridinium-based, N-(alkoxypolyalkoxyalkyl)-3-pyridinium-based, N-alkoxycarbonylmethyl-3-pyridinium-based, N-alkyl-4-pyridinium-based, N-benzyl-4-pyridinium-based, N-(alkoxypolyalkoxyalkyl)-4-pyridinium-based, N-alkoxycarbonylmethyl-4 -Pyridinium or N-alkyl-3,5-dimethyl-4-pyridinium, more preferably N-alkyl-3-pyridinium or N-alkyl-4-pyridinium, particularly preferably N-methyl-3-pyridinium, N-octyl-3-pyridinium, N-methyl-4-pyridinium or N-octyl-4-pyridinium, most preferably N-octyl-3-pyridinium or N-octyl-4-pyridinium.

[0370] Furthermore, in R 23 In the case of a pyridinium group, counter anions include sulfonate ions, carboxylate ions, tetrafluoroborate ions, hexafluorophosphate ions, hexafluoroantimonate ions, p-toluenesulfonate ions, perchlorate ions, etc., with p-toluenesulfonate ions, hexafluorophosphate ions, or hexafluoroantimonate ions being preferred.

[0371] From the perspective of color development, R in equation (1-4) 20 Preferably alkyl or aryl, more preferably 2 Rs 20 In this compound, one is an alkyl group and the other is an aryl group. The two R groups mentioned above... 20 They can be connected to form a ring.

[0372] From the perspective of color development, R in equation (1-5) 20 Preferably alkyl or aryl, more preferably aryl, and even more preferably p-methylphenyl.

[0373] From the perspective of color development, R in equation (1-6) 20 Each is preferably alkyl or aryl, more preferably methyl or phenyl.

[0374] From the perspective of color development, Z in equation (1-7) 1 It can be any counterion used to neutralize the charge, or it can be included as a whole compound in the above-mentioned Za.

[0375] Z 1 Preferably, it is a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a hexafluoroantimonate ion, a p-toluenesulfonate ion, or a perchlorate ion, and more preferably a p-toluenesulfonate ion, a hexafluorophosphate ion, or a hexafluoroantimonate ion.

[0376] In the case where L is an oxygen atom in Formula 1 or Formula 2, R is further preferred from the viewpoint of colorimetry.1 It is the group represented by the following formula (5).

[0377] [Chemical Formula 13]

[0378]

[0379] In equation (5), R 15 and R 16 Each of these groups independently represents a hydrogen atom, an alkyl group, or an aryl group; E represents an ononyl group; and * represents a bonding site with the oxygen atom represented by L in Formula 1 or Formula 2.

[0380] R 15 Or R 16 The alkyl group represented by R 2 ~R 9 and R 0 The alkyl group in R is the same, and the preferred method is also the same as R. 2 ~R 9 and R 0 The preferred method for alkyl groups is the same.

[0381] R 15 Or R 16 The aryl group represented by R 0 The aryl group in R is the same, and the preferred method is also the same. 0 The preferred method for aryl groups is the same.

[0382] E represents the onnnage group and R 23 The onnnage group is the same as that in R, and the preferred method is also the same. 23 The preferred method for the onnnage group is the same.

[0383] As a preferred method, R is preferred. 15 R represents a hydrogen atom. 16 Indicates alkyl group.

[0384] In formula (5), the onnnage group represented by E is preferably the pyridinium group represented by formula (6) below.

[0385] [Chemical Formula 14]

[0386]

[0387] In equation (6), R 17 Representing halogen atoms, alkyl groups, aryl groups, hydroxyl groups, or alkoxy groups, in R 17 In the case of multiple Rs, multiple Rs 17 They can be the same or different, or multiple Rs. 17 They can be connected to form a cycle. n² represents an integer from 0 to 4. R 18 Indicates alkyl, aryl, or aralkyl. Z b This refers to counterions used to neutralize charges.

[0388] R 17 Or R 18 The alkyl or aryl group represented by R 2 ~R 9 and R 0 alkyl or R in 0 The aryl group in R is the same, and the preferred method is also the same. 2 ~R 9 and R 0 alkyl or R in 0 The preferred method for aryl groups is the same.

[0389] R 17 The alkoxy group represented is preferably an alkoxy group having 1 to 10 carbon atoms, and more preferably a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, etc.

[0390] R 18 The aralkyl group in the aralkyl group is preferably an aralkyl group with 7 to 31 carbon atoms, more preferably an aralkyl group with 7 to 21 carbon atoms, and even more preferably an aralkyl group with 7 to 13 carbon atoms.

[0391] Specific examples of aralkyl groups include benzyl groups, etc.

[0392] The aforementioned aralkyl groups may have substituents. Examples of substituents include alkyl groups, alkoxy groups, and groups formed by combining these.

[0393] R 18 Preferably, it represents an alkyl or aralkyl group.

[0394] n2 is preferably 0.

[0395] Z b The counterion represented for neutralizing charge is Z in formula (1-7). 1 Similarly, the preferred method is also the same as Z in equation (1-7). 1 The preferred method is the same.

[0396] The following examples illustrate the case where L is an oxygen atom in Equation 1 or Equation 2, and R... 1 Specific examples of the groups represented are given, but the invention is not limited to these. In the following structural formulas, TsO - ☐ represents the toluenesulfonic acid anion, and ● represents the bonding site with the oxygen atom represented by L in Formula 1 or Formula 2.

[0397] Me represents methyl.

[0398] [Chemical Formula 15]

[0399]

[0400] [Chemical Formula 16]

[0401]

[0402] [Chemical Formula 17]

[0403]

[0404] [Chemical Formula 18]

[0405]

[0406] [Chemical Formula 19]

[0407]

[0408] [Chemical Formula 20]

[0409]

[0410] [Chemical Formula 21]

[0411]

[0412] [Chemical Formula 22]

[0413]

[0414] [Chemical Formula 23]

[0415]

[0416] [Chemical Formula 24]

[0417]

[0418] When L is an oxygen atom, if R 1 If it is aryl or straight-chain alkyl, it will not cause R based on infrared exposure. 1 Cleavage of -O bonds.

[0419] When L is a sulfur atom in Equation 1 or Equation 2, R 1 Preferably, it is a group represented by the following formula (2-1).

[0420] [Chemical Formula 25]

[0421]

[0422] In formula (2-1), ● represents the bonding site with the sulfur atom represented by L in formula 1 or formula 2, and R 21 Each of the following can be independently represented by a hydrogen atom, alkyl group, or aryl group; R 22 It indicates aryl, alkenyl, alkoxy, or onnyl.

[0423] In Equation 1 or Equation 2, L is -NR 10 In the case of - R bonded to N 1 Preferably, it is a group represented by the following formula (3-1).

[0424] [Chemical Formula 26]

[0425]

[0426] In formula (3-1), ● represents the bonding site with the nitrogen atom contained in L in formula 1 or formula 2, and X 1 and X 2 Each can be represented independently by an oxygen atom or a sulfur atom, and Y represents the group represented by the above formula (2-1).

[0427] In the above equation (2-1), regarding R 21 and R 22 The alkyl, aryl, alkenyl, alkoxy, and onnyl groups represented can refer to the descriptions of the alkyl, aryl, alkenyl, alkoxy, and onnyl groups described in the above formulas (1-1) to (1-7).

[0428] From the viewpoint of improving brush resistance, in Formula 1 or Formula 2, L preferably represents a sulfur atom or -NR. 10 -, R 10 It represents a hydrogen atom, alkyl group, or aryl group.

[0429] Specific examples of compounds represented by Formula 1 or Formula 2 are shown below, but the invention is not limited to these. In the following structural formulas, Ph represents phenyl.

[0430] [Chemical Formula 27]

[0431]

[0432] [Chemical Formula 28]

[0433]

[0434] [Chemical Formula 29]

[0435]

[0436] [Chemical Formula 30]

[0437]

[0438] [Chemical Formula 31]

[0439]

[0440] [Chemical Formula 32]

[0441]

[0442] [Chemical Formula 33]

[0443]

[0444] [Chemical Formula 34]

[0445]

[0446] [Chemical Formula 35]

[0447]

[0448] [Chemical Formula 36]

[0449]

[0450] [Chemical Formula 37]

[0451]

[0452] [Chemical Formula 38]

[0453]

[0454] [Chemical Formula 39]

[0455]

[0456] [Chemical Formula 40]

[0457]

[0458] [Chemical Formula 41]

[0459]

[0460] Furthermore, as the chromogenic compound, the chromogenic compound described in Japanese Patent Publication No. 2008-544322 or International Publication No. 2016 / 027886 is preferred.

[0461] The compounds represented by Formula 1 or Formula 2 can be synthesized by using known methods. For example, the compounds represented by Formula 1 or Formula 2 can be synthesized by the methods described in

[0109] to

[0113] of Japanese Patent Application Publication No. 2020-69789.

[0462] A single chromogenic compound can be used alone, or two or more can be used in combination.

[0463] The content of the chromogenic compound in the image recording layer is preferably 0.1% to 95% by mass, more preferably 0.5% to 40% by mass, and even more preferably 1% to 20% by mass, relative to the total solid content of the image recording layer.

[0464] Chromogenic compounds themselves possess excellent infrared absorption properties, thus functioning well as infrared absorbers. Therefore, when chromogenic compounds are used in the image recording layer of the lithographic printing plate original, it is actually not necessary to use other infrared absorbers besides the chromogenic compounds, although the aforementioned image recording layer may contain other infrared absorbers.

[0465] [Polymerization initiator]

[0466] Polymerization initiators are compounds that generate free radicals or cations through the energy of light, heat, or both, and can be appropriately selected and used from known thermal polymerization initiators, compounds with bonds having low bond dissociation energies, photopolymerization initiators, etc.

[0467] As a polymerization initiator, an infrared-sensitive polymerization initiator is preferred. Furthermore, a free radical polymerization initiator is preferred. Two or more free radical polymerization initiators may be used in combination.

[0468] Free radical polymerization initiators can be either electron-accepting polymerization initiators or electron-donating polymerization initiators.

[0469] <Electron-receiving polymerization initiators>

[0470] Examples of electron-accepting polymerization initiators include organohalides, carbonyl compounds, azo compounds, organic peroxides, metallocene compounds, azide compounds, hexaaryl biimidazole compounds, disulfone compounds, oxime ester compounds, and onium salt compounds.

[0471] As an organohalide, the compounds described in paragraphs 0022 to 0023 of Japanese Patent Application Publication No. 2008-195018 are preferred, for example.

[0472] As a carbonyl compound, the compound described in paragraph 0024 of Japanese Patent Application Publication No. 2008-195018 is preferred, for example.

[0473] Examples of azo compounds include those described in Japanese Patent Application Publication No. 8-108621.

[0474] As an organic peroxide, the compound described in paragraph 0025 of Japanese Patent Application Publication No. 2008-195018 is preferred, for example.

[0475] As a metallocene compound, the compound described in paragraph 0026 of Japanese Patent Application Publication No. 2008-195018 is preferred, for example.

[0476] Examples of azide compounds include 2,6-bis(4-azidobenzylidene)-4-methylcyclohexanone.

[0477] As a hexaaryl biimidazole compound, the compound described in paragraph 0027 of Japanese Patent Application Publication No. 2008-195018 is preferred, for example.

[0478] Examples of disulfone compounds include those described in Japanese Patent Application Publication No. 61-166544 and Japanese Patent Application Publication No. 2002-328465.

[0479] As an oxime ester compound, the compounds described in paragraphs 0028 to 0030 of Japanese Patent Application Publication No. 2008-195018 are preferred, for example.

[0480] Among electron-accepting polymerization initiators, onium salt compounds such as iodinated salts, sulfonium salts, and azazine onium salts are preferred. Iodinated salts and sulfonium salts are particularly preferred. Specific examples of iodinated salts and sulfonium salts are shown below, but the present invention is not limited to these.

[0481] As an example of iodized salt, diphenyliodonium salt is preferred, especially diphenyliodonium salt having an electron-donating group as a substituent, for example, a diphenyliodonium salt substituted with an alkyl or alkoxy group, and asymmetric diphenyliodonium salt is preferred. Specific examples include diphenyliodonium (hexafluorophosphate), 4-methoxyphenyl-4-(2-methylpropyl)phenyliodonium (hexafluorophosphate), 4-(2-methylpropyl)phenyl-p-tolyliodonium (hexafluorophosphate), 4-hexyloxyphenyl-2,4,6-trimethoxyphenyliodonium (hexafluorophosphate), 4-hexyloxyphenyl-2,4-diethoxyphenyliodonium (tetrafluoroborate), 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium (1-perfluorobutylsulfonate), 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium (hexafluorophosphate), and bis(4-tert-butylphenyl)iodonium (hexafluorophosphate).

[0482] Examples of sulfonium salts include triarylsulfonium salts, particularly those having electron-withdrawing groups as substituents, such as at least a portion of the groups on the aromatic ring being replaced by halogen atoms. More preferably, triarylsulfonium salts have a total number of halogen atoms substituting four or more on the aromatic ring. Specific examples include triphenylsulfonium hexafluorophosphate and triphenylsulfonium benzoate.

[0483] Bis(4-chlorophenyl)phenylthionesium = benzoylcarbamate, bis(4-chlorophenyl)-4-methylphenylsulfonium = tetrafluoroborate, tris(4-chlorophenyl)sulfonium = 3,5-bis(methoxycarbonyl)benzenesulfonate, tris(4-chlorophenyl)sulfonium = hexafluorophosphate, tris(2,4-dichlorophenyl)sulfonium = hexafluorophosphate.

[0484] The polymerization initiator preferably contains an onium salt compound as an electron-accepting polymerization initiator.

[0485] Electron-receiving polymerization initiators can be used alone or in combination with two or more.

[0486] From the viewpoints of color development during exposure, fading during white light exposure, brush resistance, and stability of the coating solution, the content of electron-receiving polymerization initiator in the total solids composition of the image recording layer is preferably 0.1 to 30% by mass, more preferably 0.1 to 20% by mass, and even more preferably 0.5 to 15% by mass.

[0487] <Electron-donating polymerization initiators>

[0488] Electron-donating polymerization initiators help improve the brush resistance of lithographic printing plates made from lithographic printing master plates. Five examples of electron-donating polymerization initiators can be cited.

[0489] (i) Alkyl or arylate complexes: These are thought to involve oxidative cleavage of carbon-heterobonds, generating active free radicals. Specifically, examples include borates.

[0490] (ii) Glycine compounds: It is believed that the CX bond on the carbon adjacent to nitrogen is broken due to oxidation, generating an active free radical. X is preferably a hydrogen atom, a carboxyl group, a trimethylsilyl group, or a benzyl group. Specifically, examples include N-phenylglycine derivatives (which may have substituents in the phenyl group), N-phenyliminodiacetic acid (which may have substituents in the phenyl group), etc.

[0491] (iii) Sulfur-containing compounds: Compounds formed by replacing the nitrogen atom of the above-mentioned aminoacetic acid compounds with a sulfur atom can generate active free radicals through the same action. Specifically, examples include phenylthioacetic acid (which may have substituents in the phenyl group).

[0492] (iv) Tin-containing compounds: Compounds formed by replacing the nitrogen atoms of the above-mentioned glycine compounds with tin atoms can generate active free radicals through the same action.

[0493] (v) Sulfites: These can generate reactive free radicals through oxidation. Examples include sodium arylsulfinates.

[0494] Among electron-donating polymerization initiators, borates are preferred. Tetraarylborates or monoalkyltriarylborates are preferred as borates, and tetraarylborates are more preferred from the viewpoint of compound stability.

[0495] The counter cations of borate compounds are preferably alkali metal ions or tetraalkylammonium ions, and more preferably sodium ions, potassium ions or tetrabutylammonium ions.

[0496] The polymerization initiator preferably contains a borate compound as an electron-donating polymerization initiator.

[0497] Specific examples of borate compounds include the following compounds. Wherein, X c + It represents a monovalent cation, preferably an alkali metal ion or a tetraalkylammonium ion, more preferably an alkali metal ion or a tetrabutylammonium ion. Furthermore, Bu represents n-butyl.

[0498] [Chemical Formula 42]

[0499]

[0500] [Chemical Formula 43]

[0501]

[0502] [Chemical Formula 44]

[0503]

[0504] [Chemical Formula 45]

[0505]

[0506] Electron-donating polymerization initiators can be used alone or in combination with two or more.

[0507] From the viewpoint of color development, brush resistance, and coating stability during exposure, the content of electron-donating polymerization initiator in the total solids composition of the image recording layer is preferably 0.1 to 20% by mass, more preferably 0.3 to 15% by mass, and even more preferably 0.5 to 10% by mass.

[0508] [Polymerizing compounds]

[0509] The polymerizable compound can be, for example, a free radical polymerizable compound or a cationic polymerizable compound, and is preferably an addition polymerizable compound (olefin unsaturated compound) having at least one olefin unsaturated bond. As an olefin unsaturated compound, a compound having at least one terminal olefin unsaturated bond is preferred, and a compound having two or more terminal olefin unsaturated bonds is more preferred. The polymerizable compound can be, for example, in the chemical form of a monomer, a prepolymer (i.e., a dimer, a trimer), or an oligomer, or a mixture thereof.

[0510] From the viewpoint of brush resistance, the polymerizable compound is preferably 5-functional or more, more preferably 7-functional or more, and even more preferably 11-functional or more. "Functionality" refers to a group (functional group) that contributes to polymerization, preferably an olefinic unsaturated bond. For example, "4-functional or more" means that the number of groups that contribute to polymerization is 4 or more.

[0511] There are no particular limitations on polymerizable compounds, but they are usually 20 or less functional.

[0512] From the viewpoint of brush resistance, the polymerizable compound is preferably an olefin unsaturated compound with 5 or more functions, more preferably an olefin unsaturated compound with 7 or more functions, and even more preferably an olefin unsaturated compound with 11 or more functions.

[0513] The molecular weight (weight-average molecular weight in the case of a molecular weight distribution) of polymeric compounds is not particularly limited, but from the viewpoint of machine developability, the one with a smaller molecular weight is preferred, and from the viewpoint of brush resistance, the one with a larger molecular weight is preferred.

[0514] The molecular weight is preferably less than 15,000. Furthermore, the molecular weight is preferably 100 or higher.

[0515] From the perspective of balancing on-machine developability and brush resistance, the molecular weight is preferably 100 or more and less than 15,000, more preferably 500 or more and less than 13,000, and even more preferably 1,000 or more and less than 10,000.

[0516] As a preferred embodiment, the image recording layer preferably contains a polymeric compound with seven or more functions and a molecular weight of less than 15,000 as the polymeric compound.

[0517] As a preferred embodiment, the image recording layer preferably contains a polymeric compound with 11 or more functions and a molecular weight of less than 15,000 as the polymeric compound.

[0518] Examples of monomers include unsaturated carboxylic acids (e.g., acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid), their esters, and amides. Esters of unsaturated carboxylic acids with polyols and amides of unsaturated carboxylic acids with polyamines are preferred. Furthermore, addition reactions of unsaturated carboxylic acid esters or amides with nucleophilic substituents such as hydroxyl, amino, or thiol groups with monofunctional or polyfunctional isocyanates or epoxides, and dehydration condensation reactions with monofunctional or polyfunctional carboxylic acids are also preferred. Furthermore, addition reactions of unsaturated carboxylic acid esters or amides with electrophilic substituents such as isocyanate groups or epoxy groups with monofunctional or polyfunctional alcohols, amines, or thiols are also preferred; substitution reactions of unsaturated carboxylic acid esters or amides with dissociative substituents such as halogen atoms or toluenesulfonyloxy groups with monofunctional or polyfunctional alcohols, amines, or thiols are even more preferred. Furthermore, as another example, compounds in which the above-mentioned unsaturated carboxylic acids are replaced with unsaturated phosphonic acids, styrene, vinyl ethers, etc., can also be used. These compounds are described in Japanese Patent Application Publication Nos. 2006-508380, 2002-287344, 2008-256850, 2001-342222, 9-179296, 9-179297, 9-179298, 2004-294935, 2006-243493, 2002-275129, 2003-64130, 2003-280187, and 10-333321.

[0519] Specific examples of ester monomers of polyol compounds and unsaturated carboxylic acids, and as acrylates, include ethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, trimethylolpropane triacrylate, hexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol tetraacrylate, sorbitol triacrylate, ethylene oxide (EO) modified triacrylate of isocyanurate, and polyester acrylate oligomers. Examples of methacrylates include tetramethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, pentaerythritol trimethacrylate, bis[p-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]dimethylmethane, and bis[p-(methacryloyloxyethoxy)phenyl]dimethylmethane. Furthermore, specific examples of polyamine compounds and amide monomers of unsaturated carboxylic acids include methylenebisacrylamide, methylenebisacrylamide, 1,6-hexamethylenebisacrylamide, 1,6-hexamethylenebisacrylamide, diethylenetriaminetriacrylamide, xylenebisacrylamide, and xylenebisacrylamide.

[0520] Furthermore, it is preferable to use urethane-based addition polymerizable compounds produced by the addition reaction of isocyanate and hydroxyl groups. For example, a vinyl urethane compound containing two or more polymerizable vinyl groups per molecule can be obtained by adding a polyisocyanate compound having two or more isocyanate groups per molecule to a vinyl monomer containing hydroxyl groups represented by the following formula (M), as described in Japanese Patent Publication No. 48-41708.

[0521] CH2=C(R) M4 COOCH2CH(R) M5 OH (M)

[0522] In formula (M), R M4 and R M5 Each can be used to represent a hydrogen atom or a methyl group independently.

[0523] Furthermore, the preferred materials are the urethane acrylates described in Japanese Patent Application Publication No. 51-37193, Japanese Patent Publication No. 2-32293, Japanese Patent Publication No. 2-16765, Japanese Patent Application Publication No. 2003-344997, Japanese Patent Application Publication No. 2006-65210, Japanese Patent Application Publication No. 58-49860, Japanese Patent Application Publication No. 56-17654, Japanese Patent Application Publication No. 62-39417, and Japanese Patent Application Publication No. 62. Carbamate compounds having an ethylene oxide backbone as described in Japanese Patent Application Publication No. 39418, Japanese Patent Application Publication No. 2000-250211, Japanese Patent Application Publication No. 2007-94138, US Patent No. 7153632, Japanese Patent Application Publication No. 8-505958, Japanese Patent Application Publication No. 2007-293221, and Japanese Patent Application Publication No. 2007-293223, and carbamate compounds having hydrophilic groups.

[0524] The details of the polymeric compound's structure, whether it is used alone or in combination, the amount added, etc., can be arbitrarily set taking into account the end use of the original offset printing plate.

[0525] In the total solids composition of the image recording layer, the content of polymeric compounds is preferably 1 to 90% by mass, more preferably 5 to 70% by mass, and even more preferably 10 to 50% by mass.

[0526] [Hydrogen-donating compounds]

[0527] Hydrogen-donating compounds are compounds that are different from polymerization initiators, polymerizable compounds, chromogenic compounds and acid-degrading compounds, and are compounds that have at least one group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH- and -CO-OH and have a molecular weight of less than 3,000.

[0528] Groups selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH (hereinafter also referred to as "hydrogen-donating groups") are groups that can donate hydrogen atoms.

[0529] "-OH" represents a hydroxyl group, which is different from "-CO-OH" (carboxyl group) and is a group that is not bonded to -SO2-.

[0530] "-NH-" is a group that is not bonded to -SO2- or -CO-.

[0531] "Compounds that are different from polymerization initiators, polymerizable compounds, chromogenic compounds, and acid-degradable compounds" means that even compounds with the above-mentioned hydrogen-donating groups and a molecular weight of less than 3,000 are not included in hydrogen-donating compounds as long as they function as polymerization initiators, polymerizable compounds, chromogenic compounds, or acid-degradable compounds.

[0532] The polymerization initiator, polymerizable compound, and chromogenic compound are as described above.

[0533] Acid-crackable compounds are compounds that are cracked by the action of acids; specifically, they represent compounds whose intramolecular rings are broken down (ring-opening) by the action of acids. So-called acid chromophores, which crack and develop color by the action of acids, are included in acid-crackable compounds. Hydrogen-donating compounds are compounds that are different from acid chromophores.

[0534] The hydrogen-donating compound is preferably a compound having at least one partial structure represented by the following formula (I) within the molecule.

[0535] [Chemical Formula 46]

[0536]

[0537] In formula (I),

[0538] X is a group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH.

[0539] R 1A ~R 3A Each is independently a group having at least one of the following groups: hydrogen atom, carbon atom, halogen atom and heteroatom.

[0540] R 1A ~R 3A At least two of them can be connected to form a loop.

[0541] When X is a monovalent group, R 1A ~R 3A One or more hydrogen atoms contained therein are removed to form a linking bond.

[0542] When X is a divalent group, R 1A ~R 3A One or more hydrogen atoms contained therein can be further removed to form a linking bond.

[0543] As the hydrogen-donating group of X, from the viewpoint of suppressing fading during white light exposure and easily integrating with the image recording layer, -OH, -NH-, -SO2-NH- or -CO-NH- are preferred, and -OH or -SO2-NH- are even more preferred.

[0544] As R 1A ~R 3A The presence of at least one group (hereinafter also referred to as "substituent A") selected from the group consisting of hydrogen atoms, carbon atoms, halogen atoms and heteroatoms is not particularly limited, but is preferably a group having 0 to 30 carbon atoms.

[0545] There are no particular limitations on what constitutes a halogen atom; examples include fluorine, chlorine, bromine, or iodine atoms.

[0546] There are no particular restrictions on heteroatoms; examples include nitrogen, oxygen, sulfur, and phosphorus atoms.

[0547] Substituent A is not particularly limited, but is preferably a hydrogen atom or a hydrocarbon group. The hydrocarbon group may have heteroatoms or halogen atoms.

[0548] R 1A ~R 3A At least two of the atoms can be linked to form a ring. The formed ring can be a monocyclic or polycyclic ring. Examples of the formed ring include aromatic rings and aliphatic hydrocarbon rings, and the number of cyclic atoms in the formed ring is preferably 6 to 14.

[0549] When X is a monovalent group (specifically, a group selected from the group consisting of -OH, -SO2-OH, and -CO-OH), R 1A ~R 3A One or more hydrogen atoms contained therein are removed to form a linking bond.

[0550] When X is a divalent group (specifically, a group selected from the group consisting of -NH-, -SO2-NH-, and -CO-NH-), a partial structure can be constructed using formula (I), or R... 1A ~R 3A One or more hydrogen atoms contained therein are further removed to form connecting bonds.

[0551] The hydrogen-donating compound is preferably a compound having at least one partial structure represented by the above formula (I) within the molecule, or it may be a compound having at least two or more partial structures represented by the above formula (I) within the molecule.

[0552] The number of the partial structures represented by the above formula (I) within the molecule is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 5.

[0553] The hydrogen-donating compound is preferably a compound having at least one partial structure represented by the following formula (II) within the molecule.

[0554] [Chemical Formula 47]

[0555]

[0556] In formula (II),

[0557] Ar represents an aromatic cyclic group.

[0558] X is a group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH.

[0559] R 4A It is a group having at least one of the following groups: hydrogen atom, carbon atom, halogen atom and heteroatom.

[0560] m represents an integer from 1 to 5. When m represents an integer greater than 2, multiple X's can be the same or different.

[0561] n represents an integer from 0 to 5. When n represents an integer greater than 2, multiple R... 4A They can be the same or different. When n is 2 or more, multiple R... 4A They can be connected to form a ring.

[0562] When all X are monovalent groups, R 4A One or more hydrogen atoms contained in the structure are removed to form a linking bond.

[0563] When at least one X is a divalent group, R can be further removed. 4A The bond is formed by the presence of one or more hydrogen atoms.

[0564] X has the same meaning as X in equation (I), and the preferred range is also the same.

[0565] Aromatic rings in the aromatic ring group of Ar can be exemplified by aromatic hydrocarbon rings or aromatic heterocycles.

[0566] The aromatic hydrocarbon ring can be monocyclic or polycyclic. The number of ring atoms is preferably 6 to 15, more preferably 6 to 10.

[0567] Aromatic hydrocarbon rings include, for example, benzene rings, naphthalene rings, and anthracene rings. Among these, benzene rings or naphthalene rings are preferred, and benzene rings are more preferred.

[0568] Aromatic heterocycles can be monocyclic or polycyclic. The number of cyclic atoms is preferably 5 to 15.

[0569] Examples of aromatic heterocyclic rings include furan rings, thiophene rings, benzofuran rings, benzothiophene rings, dibenzofuran rings, dibenzothiophene rings, pyridine rings, indole rings, benzodiazole rings, and carbazole rings.

[0570] As R 4A The presence of at least one group (hereinafter also referred to as "substituent A1") selected from the group consisting of hydrogen atoms, carbon atoms, halogen atoms and heteroatoms is not particularly limited, but is preferably a group having 0 to 24 carbon atoms.

[0571] There are no particular limitations on what constitutes a halogen atom; examples include fluorine, chlorine, bromine, or iodine atoms.

[0572] There are no particular restrictions on heteroatoms; examples include nitrogen, oxygen, sulfur, and phosphorus atoms.

[0573] The substituent A1 is not particularly limited, but is preferably a hydrogen atom or a hydrocarbon group. The hydrocarbon group may have heteroatoms or halogen atoms.

[0574] m represents an integer from 1 to 5. m is preferably an integer from 1 to 3, and more preferably an integer of 1 or 2.

[0575] n represents an integer from 0 to 5. n is preferably an integer from 0 to 2, and more preferably an integer of 0 or 1.

[0576] When n is 2 or more, multiple R 4A They can be connected to form a ring.

[0577] Multiple R 4A The ring formed by the linkage can be a monocyclic ring or a polycyclic ring. Examples of the formed ring include aromatic rings and aliphatic hydrocarbon rings, and the number of cyclic atoms in the formed ring is preferably 6 to 10.

[0578] When X is a monovalent group (specifically, a group selected from the group consisting of -OH, -SO2-OH, and -CO-OH), R 4A One or more hydrogen atoms contained therein are removed to form a linking bond.

[0579] When X is a divalent group (specifically, a group selected from the group consisting of -NH-, -SO2-NH-, and -CO-NH-), a partial structure can be constructed using formula (I), or R... 4A One or more hydrogen atoms contained therein are further removed to form connecting bonds.

[0580] The hydrogen-donating compound is preferably a compound having at least one partial structure represented by the above formula (II) within the molecule, or it may be a compound having at least two or more partial structures represented by the above formula (II) within the molecule.

[0581] The number of the partial structures represented by the above formula (I) within the molecule is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3.

[0582] The hydrogen-donating compound is preferably a compound having at least one partial structure represented by the following formula (III) within the molecule.

[0583] [Chemical Formula 48]

[0584]

[0585] In formula (III),

[0586] X is a group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH.

[0587] R 5A It is a group having at least one of the following groups: hydrogen atom, carbon atom, halogen atom and heteroatom.

[0588] p represents an integer from 1 to 5. When p represents an integer greater than 2, multiple X's can be the same or different.

[0589] Let q represent an integer from 0 to 5. When q represents an integer greater than 2, multiple R5s can be the same or different. When q is greater than 2, multiple R5s... 5A They can be connected to form a ring.

[0590] p+q is less than 6.

[0591] When all X are monovalent groups, R 5A One or more hydrogen atoms contained therein are removed to form a linking bond.

[0592] When at least one X is a divalent group, R can be further removed. 5A It is formed by one or more hydrogen atoms in the structure.

[0593] X has the same meaning as X in equation (I), and the preferred range is also the same.

[0594] As R 5A The presence of at least one group (hereinafter also referred to as "substituent A2") selected from the group consisting of hydrogen atoms, carbon atoms, halogen atoms and heteroatoms is not particularly limited, but is preferably a group having 0 to 24 carbon atoms.

[0595] There are no particular limitations on what constitutes a halogen atom; examples include fluorine, chlorine, bromine, or iodine atoms.

[0596] There are no particular restrictions on heteroatoms; examples include nitrogen, oxygen, sulfur, and phosphorus atoms.

[0597] The substituent A2 is not particularly limited, but is preferably a hydrogen atom or a hydrocarbon group. The hydrocarbon group may have heteroatoms or halogen atoms.

[0598] p represents an integer from 1 to 5. p preferably represents an integer from 1 to 3, and more preferably an integer of 1 or 2.

[0599] q represents an integer from 0 to 5. q preferably represents an integer from 0 to 2, and more preferably an integer of 0 or 1.

[0600] When q is greater than 2, multiple R 5A They can be connected to form a ring.

[0601] Multiple R 5A The ring formed by the linkage can be a monocyclic ring or a polycyclic ring. Examples of the formed ring include aromatic rings and aliphatic hydrocarbon rings, and the number of cyclic atoms in the formed ring is preferably 6 to 10.

[0602] From the viewpoint of suppressing fading during white light exposure and easily integrating with the image recording layer, the hydrogen-donating group in the hydrogen-donating compound is preferably selected from the group consisting of -OH, -NH-, -SO2-NH- and -CO-NH-, and more preferably selected from the group consisting of -OH and -SO2-NH-.

[0603] From the viewpoint of suppressing fading during white light exposure, the hydrogen-donating compound preferably contains at least one of the aforementioned hydrogen-donating groups, more preferably at least two, and even more preferably at least three.

[0604] The number of hydrogen-donating groups contained in the hydrogen-donating compound is not particularly limited, but is preferably 10 or less, more preferably 7 or less, and even more preferably 5 or less.

[0605] As a preferred embodiment, the hydrogen-donating compound is preferably a compound having at least two groups selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH- within its molecule.

[0606] As a preferred embodiment, the hydrogen-donating compound preferably has at least one group selected from the group consisting of -OH and -SO2-NH-.

[0607] As a preferred embodiment, the hydrogen-donating compound preferably has at least two groups selected from the group consisting of -OH and -SO2-NH-.

[0608] The hydrogen-donating compound preferably has at least one phenolic hydroxyl group.

[0609] Phenolic hydroxyl groups refer to hydroxyl groups (-OH) that are directly bonded to an aromatic ring (specifically, a benzene ring).

[0610] The hydrogen-donating compound preferably has two or more phenolic hydroxyl groups.

[0611] The hydrogen-donating compound preferably has two or more but less than six phenolic hydroxyl groups, and more preferably has two or more but less than four phenolic hydroxyl groups.

[0612] Regarding "having two or more phenolic hydroxyl groups", it can be an aromatic ring bonded to one phenolic hydroxyl group that further bonds to one or more phenolic hydroxyl groups, or it can be an aromatic ring different from the aromatic ring bonded to one phenolic hydroxyl group that further bonds to one or more phenolic hydroxyl groups.

[0613] The hydrogen-donating compound is preferably a compound represented by formula (IV) or a compound represented by formula (V).

[0614] [Chemical Formula 49]

[0615]

[0616] In equation (IV),

[0617] X A It represents -OH.

[0618] R 6A It represents an organic group or halogen atom.

[0619] r represents an integer from 1 to 5.

[0620] s represents an integer from 0 to 5. When s represents an integer greater than 2, multiple R... 6A They can be the same or different. When s is 2 or more, multiple R... 6A They can be connected to form a ring.

[0621] In equation (V),

[0622] L represents a single bond or a divalent linker.

[0623] X B It represents -OH.

[0624] R 7A It represents an organic group or halogen atom.

[0625] X cIt represents -OH.

[0626] R 8A It represents an organic group or halogen atom.

[0627] t represents an integer from 1 to 5.

[0628] u represents an integer from 0 to 5. When u represents an integer greater than 2, multiple R... 7A They can be the same or different. When u is 2 or higher, multiple R... 7A They can be connected to form a ring.

[0629] v represents an integer from 1 to 5.

[0630] w represents an integer from 0 to 5. When w represents an integer greater than 2, multiple R... 8A They can be the same or different. When w is 2 or higher, multiple R... 8A They can be connected to form a ring.

[0631] As R 6A R 7A R 8A The organic groups are not particularly limited; examples include alkyl and aryl groups.

[0632] Alkyl groups can be straight-chain or branched, and examples include alkyl groups with 1 to 10 carbon atoms.

[0633] Aryl groups can be monocyclic or polycyclic, and examples of aryl groups with 6 to 20 carbon atoms can be found.

[0634] As R 6A R 7A R 8A The halogen atom is not particularly limited and can include fluorine, chlorine, bromine, or iodine atoms.

[0635] r represents an integer from 1 to 5. r preferably represents an integer from 1 to 3, and more preferably represents 1 or 2.

[0636] s represents an integer from 0 to 5. s preferably represents an integer from 0 to 3, and more preferably represents 0 or 1.

[0637] r+s is preferably 6 or less.

[0638] Multiple R 6A The resulting ring can be a monocyclic or polycyclic ring. Examples of the formed ring include aliphatic hydrocarbon rings, and the number of cyclic atoms in the formed ring is preferably 6 to 10.

[0639] The divalent linker of L is not particularly limited, and examples include alkylene groups, -CO-, -SO2-, -O-, or combinations thereof.

[0640] Examples of alkylene groups include straight-chain or branched alkylene groups having 1 to 5 carbon atoms.

[0641] The alkylene group may further have substituents. There are no particular limitations on the substituents; examples include aryl groups (preferably with 6 to 10 carbon atoms). The aryl group may further have substituents; examples include hydroxyl groups.

[0642] t represents an integer from 1 to 5. t preferably represents an integer from 1 to 3, and more preferably represents 1 or 2.

[0643] u represents an integer from 0 to 5. u preferably represents an integer from 0 to 3, and more preferably represents 0 or 1.

[0644] The t+u value is preferably 6 or less.

[0645] Multiple R 7A The resulting ring can be a monocyclic or polycyclic ring. Examples of the formed ring include aliphatic hydrocarbon rings, and the number of cyclic atoms in the formed ring is preferably 6 to 10.

[0646] v represents an integer from 1 to 5. v preferably represents an integer from 1 to 3, and more preferably represents 1 or 2.

[0647] w represents an integer from 0 to 5. w preferably represents an integer from 0 to 3, and more preferably represents 0 or 1.

[0648] The preferred value for v+w is 6 or less.

[0649] Multiple R 8A The resulting ring can be a monocyclic or polycyclic ring. Examples of the formed ring include aliphatic hydrocarbon rings, and the number of cyclic atoms in the formed ring is preferably 6 to 10.

[0650] The hydrogen-donating compound is a low molecular weight compound with a molecular weight of less than 3,000, preferably a low molecular weight compound with a molecular weight of less than 1,500, and more preferably a low molecular weight compound with a molecular weight of less than 1,000.

[0651] Here, the low molecular weight compound in this invention is not a so-called polymer or oligomer obtained by using an initiator to break the unsaturated bonds of a compound having unsaturated bonds (so-called polymerizable monomers) and causing the bonds to grow in a chain, but a compound with a specified molecular weight of 3000 or less (more preferably 2000 or less, and even more preferably 1000 or less) (a compound that does not substantially have a molecular weight distribution).

[0652] The molecular weight of the hydrogen-donating compound is not particularly limited, but it is preferably 50 or more, more preferably 100 or more, and even more preferably 200 or more.

[0653] As a preferred embodiment, from the viewpoint of machine developability and brush resistance, the molecular weight is preferably 50 or more and 3000 or less, more preferably 100 or more and 1500 or less, and even more preferably 200 or more and 1000 or less.

[0654] Specific examples of hydrogen-donating compounds are shown below, but the invention is not limited to these.

[0655] [Chemical Formula 50]

[0656]

[0657] [Chemical Formula 51]

[0658]

[0659] [Chemical Formula 52]

[0660]

[0661] One hydrogen-donating compound can be used alone, or two or more can be used in combination.

[0662] In the total solids composition of the image recording layer, the content of hydrogen-donating compounds is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 1 to 10% by mass.

[0663] In an on-machine developing lithographic printing plate, the image recording layer may contain other infrared absorbers, acid chromophores, polymers, chain transfer agents, low-molecular-weight hydrophilic compounds, sensitizers, and other components besides the aforementioned chromophores.

[0664] (Other infrared absorbers)

[0665] The aforementioned image recording layer may contain infrared absorbers other than chromophores.

[0666] Pigments and dyes are examples of other infrared absorbers.

[0667] As dyes that can be used as other 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 thiolate complexes.

[0668] Among these dyes, particularly preferred dyes include anthocyanins, squaric acid dyes, pyranonium salts, nickel thiol complexes, and indocyanine dyes. Additionally, anthocyanins or indocyanine dyes can be mentioned. Anthocyanins are particularly preferred.

[0669] 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 also 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.

[0670] Furthermore, compounds described in Japanese Patent Application Publication No. 5-5005, paragraphs 0008-0009, and Japanese Patent Application Publication No. 2001-222101, paragraphs 0022-0025, can be preferred.

[0671] As a pigment, the preferred compounds are those described in paragraphs 0072 to 0076 of Japanese Patent Application Publication No. 2008-195018.

[0672] Other infrared absorbers can be used in combination, either alone or in combination with two or more. Furthermore, pigments and dyes can be used in combination as other infrared absorbers.

[0673] From the viewpoint of color development and UV resistance of the obtained lithographic printing plate, it is preferable that the content of other infrared absorbers in the image recording layer is less than the content of the color-developing compound, and more preferably that the image recording layer does not contain other infrared absorbers.

[0674] The image recording layer preferably contains an acid chromophore in addition to a chromophore compound having groups that are cleaved by infrared exposure.

[0675] [Acid colorant]

[0676] The "acid chromophore" used in this invention refers to a compound that has the property of changing the color of an image recording layer by heating it in a state where it has received protons from an electron-accepting compound (such as an acid). As an acid chromophore, colorless compounds having partial skeletons such as lactones, lactams, sulfolactones, spiropyrans, esters, and amides are particularly preferred, as these partial skeletons rapidly undergo ring-opening or cleavage upon contact with an electron-accepting compound.

[0677] As a specific example of an acid colorant, the acid colorant described in International Publication No. 2020 / 158138 is preferably cited.

[0678] From the viewpoint of color development, the acid colorant used in this invention is preferably selected from at least one compound from the group consisting of spiropyran compounds, spiroxazine compounds, spironolactone compounds, and spironolactam compounds.

[0679] From the viewpoint of visibility, the hue of the pigment after coloring is preferably green, blue, or black.

[0680] Furthermore, from the viewpoint of color development and visual recognition, it is preferable that the aforementioned acid colorant contains a colorless pigment.

[0681] 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.

[0682] Furthermore, from the viewpoint of colorimetric properties and visual recognizability of the exposed portion, the colorless pigment described above is preferably a colorless pigment having a phthalide structure or a fluorane structure.

[0683] Furthermore, from the viewpoint of color development and visual recognition of the exposed portion, the aforementioned colorless pigment having a phthaloyl or fluorane structure is preferably a compound represented by any one of the following formulas (Le-1) to (Le-3), and more preferably a compound represented by the following formula (Le-2).

[0684] [Chemical Formula 53]

[0685]

[0686] 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 X10 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.

[0687] As the electron-donating group in the ERG of formulas (Le-1) to (Le-3), from the viewpoint of color development and visual recognition of the exposed part, it is preferably an amino group, alkylamino group, arylamino group, heteroarylamino group, dialkylamino group, monoalkyl monoarylamino group, monoalkyl monoheteroarylamino group, diarylamino group, diheteroarylamino group, monoaryl monoheteroarylamino group, alkoxy group, aryloxy group, heteroaryloxy group, or alkyl group; more preferably an amino group, alkylamino group, arylamino group, heteroarylamino group, dialkylamino group, monoalkyl monoheteroarylamino group, diarylamino group, diheteroarylamino group, monoaryl monoheteroarylamino group, alkoxy group, or aryloxy group; even more preferably a monoalkyl monoarylamino group, diarylamino group, diheteroarylamino group, or monoaryl monoheteroarylamino group; and especially preferably a monoalkyl monoarylamino group.

[0688] 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 with 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 with a substituent at at least one ortho position and an electron-donating group at the para position and an aryl group or a heteroaryl group with an electron-donating group. Particularly preferred is an amino group having a phenyl group with a substituent at at least one ortho position and an electron-donating group at the para position and an aryl group or a heteroaryl group with an electron-donating group.

[0689] 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.

[0690] Furthermore, from the viewpoint of color development and visual recognition of the exposed portion, the electron-donating groups of the aforementioned aryl or heteroaryl groups 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.

[0691] From the viewpoint of color development and visual recognition 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.

[0692] From the viewpoint of color development and visual recognition of the exposed area, 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.

[0693] 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 as C.

[0694] 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.

[0695] 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.

[0696] Furthermore, from the viewpoint of color development and visual recognition of the exposed portion, the colorless pigment having the above-mentioned phthaloyl or fluorane 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).

[0697] [Chemical Formula 54]

[0698]

[0699] 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.

[0700] 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.

[0701] Furthermore, from the viewpoint of color development and visual recognition of the exposed portion, the aforementioned colorless pigment having a phthaloyl or fluorane structure is further preferably a compound represented by any one of the following formulas (Le-7) to (Le-9), and particularly preferably a compound represented by the following formula (Le-8).

[0702] [Chemical Formula 55]

[0703]

[0704] 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.

[0705] 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.

[0706] From the viewpoint of color development and visual recognition 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.

[0707] 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.

[0708] 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.

[0709] 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 substituents in Rc1 and Rc2, which will be described later, can be cited as examples.

[0710] 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.

[0711] 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.

[0712] Furthermore, in formula (Le-8), from the viewpoint of color development and visual recognizability of the exposed portion, Rb1 and Rb2 are each independently preferred to be 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.

[0713] Furthermore, from the viewpoint of color development and visual recognition 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.

[0714] Furthermore, as an acid colorant, from the viewpoint of color development and visual recognition of the exposed area, it is preferable to include a compound represented by the following formula (Le-10).

[0715] [Chemical Formula 56]

[0716]

[0717] 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.

[0718] 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.

[0719] Ar2 in formula (Le-10) has the same meaning as Rc1 and Rc2 in formulas (Le-7) to (Le-9), and the preferred method is also the same.

[0720] Furthermore, as an acid colorant, from the viewpoint of color development and visual recognition of the exposed area, it is preferable to include a compound represented by the following formula (Le-A).

[0721] [Chemical Formula 57]

[0722]

[0723] In formula (Le-A), ERG independently represents electron-donating groups, n11 represents an integer from 1 to 5, n12 represents an integer from 0 to 2, 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, and Rb4 independently represents hydrogen atoms, alkyl, aryl or heteroaryl groups.

[0724] The ERG, X1~X4, Y1, Y2 and Rb4 in formula (Le-A) have the same meaning as the ERG, X1~X4, Y1, Y2 and Rb4 in formulas (Le-1) to (Le-3), and the preferred methods are also the same.

[0725] In formula (Le-A), n11 is preferably an integer from 1 to 3, and more preferably an integer of 1 or 2.

[0726] In formula (Le-A), n12 is preferably 0 or 1, more preferably 0.

[0727] Furthermore, as an acid colorant, from the viewpoint of color development and visual recognition of the exposed area, it is preferable to include a compound represented by the following formula (Le-11).

[0728] [Chemical Formula 58]

[0729]

[0730] In formula (Le-11), ERG independently represents electron-donating groups, n11 represents an integer from 1 to 5, 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, and Rb2 and Rb4 independently represent hydrogen atoms, alkyl, aryl or heteroaryl groups.

[0731] The ERG, X1~X4, Y1, Y2, Rb2 and Rb4 in formula (Le-11) have the same meaning as the ERG, X1~X4, Y1, Y2, Rb2 and Rb4 in formulas (Le-1) to (Le-3), and the preferred methods are also the same.

[0732] In formula (Le-11), n11 is preferably an integer from 1 to 3, and more preferably an integer of 1 or 2.

[0733] The alkyl groups in formulas (Le-1) to (Le-9), (Le-A) or (Le-11) can be straight chains, branched chains, or ring structures.

[0734] Furthermore, the number of carbon atoms of the alkyl group in formulas (Le-1) to (Le-9), (Le-A) or (Le-11) is preferably 1 to 20, more preferably 1 to 8, even more preferably 1 to 4, and especially preferably 1 or 2.

[0735] The number of carbon atoms in the aryl group in formulas (Le-1) to (Le-11) and (Le-A) is preferably 6 to 20, more preferably 6 to 10, and especially preferably 6 to 8.

[0736] As for the aryl group in formulas (Le-1) to (Le-11) and (Le-A), specifically, examples include phenyl, naphthyl, anthracene, and phenanthrene groups that can have substituents.

[0737] As for the heteroaryl groups in formulas (Le-1) to (Le-11) and (Le-A), specifically, those that can have substituents, such as furanyl, pyridinyl, pyrimidinyl, pyrazolyl, and phenylthioyl, can be cited.

[0738] Furthermore, the monovalent organic groups, alkyl, aryl, heteroaryl, dialkylaniline, alkylamino, and alkoxy groups in formulas (Le-1) to (Le-11) and (Le-A) 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, and cyano. Moreover, these substituents can be further substituted by these substituents.

[0739] Furthermore, from the viewpoint of color development and visual recognizability of the exposed area, the acid colorant is preferably a compound represented by any one of the following formulas 3a and 3b.

[0740] As a preferred embodiment, the acid colorant is preferably a compound represented by any one of the following formulas 3a and 3b.

[0741] [Chemical Formula 59]

[0742]

[0743] In equation (3a),

[0744] Ar1 and Ar2 independently represent aryl or heteroaryl groups, respectively.

[0745] R 10 R 11 Each of these can be used independently to represent a hydrogen atom, alkyl group, aryl group, or heteroaryl group.

[0746] In equation (3b), ERG independently represents electron-donating groups, n represents an integer from 1 to 5, X1 to X4 independently represent hydrogen atoms, halogen atoms, or monovalent organic groups, Y1 and Y2 independently represent C or N, X1 does not exist when Y1 is N, and X4 does not exist when Y2 is N, R 12 and R 13 Each can be independently represented by a hydrogen atom, alkyl group, aryl group, or heteroaryl group.

[0747] The alkyl groups in formulas (3a) to (3b) can be straight chains, branched chains, or ring structures.

[0748] Furthermore, the number of carbon atoms of the alkyl group in formulas (3a) to (3b) is preferably 1 to 20, more preferably 1 to 8, even more preferably 1 to 4, and especially preferably 1 or 2.

[0749] The number of carbon atoms in the aryl group in formulas (3a) to (3b) is preferably 6 to 20, more preferably 6 to 10, and especially preferably 6 to 8.

[0750] As aryl groups in formulas (3a) to (3b), examples include phenyl, naphthyl, anthracene, and phenanthrene groups, which may have substituents.

[0751] As for the heteroaryl groups in formulas (3a) to (3b), specifically, those that can have substituents, such as furanyl, pyridinyl, pyrimidinyl, pyrazolyl, and thiophene, can be cited.

[0752] The ERG in equation (3b) has the same meaning as the ERG in equations (Le-1) to (Le-3), and the preferred method is also the same.

[0753] In equation (3b), n is preferably an integer from 1 to 3, and more preferably an integer of 1 or 2.

[0754] The monovalent organic group in formula (3b) and the X5 to X in formulas (Le-2) to (Le-3) are respectively X5 to X5. 10 The meanings of the monovalent organic groups are the same, and the preferred methods are also the same.

[0755] Furthermore, the monovalent organic groups, alkyl groups, aryl groups, heteroaryl groups, etc., in formulas (3a) to (3b) can have substituents. Examples of substituents include alkyl, aryl, heteroaryl, halogen atoms, amino, alkylamino, arylamino, heteroarylamino, dialkylamino, monoalkylmonoarylamino, monoalkylmonoarylamino, diarylamino, diheteroarylamino, monoarylmonoarylamino, hydroxyl, alkoxy, aryloxy, heteroaryloxy, acyl, alkoxycarbonyl, aryloxycarbonyl, heteroaryloxycarbonyl, cyano, etc. Moreover, these substituents can be further replaced by these substituents.

[0756] As a preferred colorless pigment having the above-mentioned phthaloyl or fluorane structure, there is no particular limitation, and for example, the compounds described in

[0141] to

[0150] of Japanese Patent Application Publication No. 2023-98447 can be cited.

[0757] Furthermore, as an acid colorant, compounds described in

[0151] to

[0188] of Japanese Patent Application Publication No. 2023-98447 can also be used.

[0758] These acid colorants can be used alone or in combination with two or more ingredients.

[0759] The content of acid colorant is preferably 0.5% to 10% by mass, more preferably 1% to 5% by mass, relative to the total solids content of the image recording layer.

[0760] (Polymer compounds)

[0761] Polymer compounds can function as adhesive polymers in image recording layers, or they can exist in image recording layers as polymer particles.

[0762] <Adhesive Polymers>

[0763] As an adhesive polymer, a polymer with film-forming properties is preferred, and (meth)acrylic resins, polyvinyl acetal resins, and polyurethane resins are preferred examples.

[0764] As an adhesive polymer used in image recording layers, an adhesive polymer having epoxy alkyl chains is preferred. The adhesive polymer having epoxy alkyl chains may have poly(epoxyalkyl) sites in the main chain or in the side chains. Furthermore, it may be a graft polymer with poly(epoxyalkyl) sites in the side chains, or a block copolymer consisting of blocks composed of repeating units containing poly(epoxyalkyl) sites and blocks composed of repeating units not containing (epoxyalkyl) sites.

[0765] When the main chain has a poly(epoxy) site, polyurethane resin is preferred. Examples of polymers whose main chain has a poly(epoxy) site in the side chain include (meth)acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, polystyrene resins, phenolic varnish-type phenolic resins, polyester resins, synthetic rubbers, and natural rubbers, with (meth)acrylic resins being particularly preferred.

[0766] As an epoxide, an epoxide with 2 to 6 carbon atoms is preferred, and ethylene oxide or propylene oxide is particularly preferred.

[0767] The number of repeating epoxides in the poly(epoxide) portion is preferably 2 to 120, more preferably 2 to 70, and even more preferably 2 to 50.

[0768] If the number of repetitions of the epoxide is 120 or less, the decrease in brush resistance caused by abrasion and the decrease in brush resistance caused by the deterioration of ink acceptability can be suppressed, and therefore it is preferred.

[0769] Regarding the poly(epoxy) portion, as a side chain of the adhesive polymer, it is preferably contained in a structure represented by the following formula (AO), and as a side chain of the (meth)acrylic resin, it is more preferably contained in a structure represented by the following formula (AO).

[0770] [Chemical Formula 60]

[0771]

[0772] In formula (AO), y represents 2 to 120, R1 represents a hydrogen atom or an alkyl group, and R2 represents a hydrogen atom or a monovalent organic group.

[0773] As a monovalent organic group, it is preferably an alkyl group having 1 to 6 carbon atoms. Specifically, examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, cyclopentyl, and cyclohexyl.

[0774] In formula (AO), y is preferably 2 to 70, more preferably 2 to 50. R1 is preferably a hydrogen atom or a methyl group, especially preferably a hydrogen atom. R2 is especially preferably a hydrogen atom or a methyl group.

[0775] To improve the strength of the coating in the imaging section, the adhesive polymer can be cross-linked. To achieve cross-linking, cross-linking functional groups, such as olefinic unsaturated bonds, are introduced into the main chain or side chains of the polymer. These cross-linking functional groups can be introduced through copolymerization or through polymer reactions.

[0776] Examples of polymers with olefinic unsaturated bonds in the main chain of the molecule include poly-1,4-butadiene and poly-1,4-isoprene.

[0777] Examples of polymers having olefinically unsaturated bonds in the side chains of a molecule include polymers of esters or amides of acrylic acid or methacrylic acid, and polymers in which the residues of the ester or amide (R of -COOR or -CONHR) have olefinically unsaturated bonds.

[0778] As an example of a residue (R) having an olefinic unsaturated bond, -(CH2) can be cited. n CR 1A =CR 2A R 3A -(CH2O) n CH2CR 1A =CR 2A R 3A -(CH2CH2O) n CH2CR 1A =CR 2A R 3A -(CH2) n NH-CO-O-CH2CR 1A =CR 2A R 3A -(CH2) n -O-CO-CR 1A =CR 2A R 3A and -(CH2CH2O)2-X A (where R) A1 ~R A3 Each of the following independently represents a hydrogen atom, a halogen atom, and an alkyl, aryl, alkoxy, or aryloxy group having 1 to 20 carbon atoms, R A1 With R A2 Or R A3 They can bond together to form a ring. n represents an integer from 1 to 10. X A This represents a dicyclopentadiene residue.

[0779] Specific examples of ester residues include -CH2CH=CH2, -CH2CH2O-CH2CH=CH2, -CH2C(CH3)=CH2, -CH2CH=CH-C6H5, -CH2CH2OCOCH=CH-C6H5, -CH2CH2-NHCOO-CH2CH=CH2 and -CH2CH2O-X (where X represents a dicyclopentadiene residue).

[0780] Specific examples of amide residues include -CH2CH=CH2, -CH2CH2-Y (where Y represents a cyclohexene residue), and -CH2CH2-OCO-CH=CH2.

[0781] Crosslinkable adhesive polymers, for example, by adding radicals to the crosslinking functional group (polymerization initiation radicals or growth radicals of the polymerization process of the polymeric compound), directly or via the polymeric chain of the polymeric compound, form crosslinks and cure between polymer molecules. Alternatively, atoms in the polymer (e.g., hydrogen atoms on carbon atoms adjacent to the functional crosslinking group) are extracted by free radicals and generate polymer free radicals that bond with each other, thereby forming crosslinks and curing between polymer molecules.

[0782] From the viewpoint of good sensitivity and good storage stability, the content of crosslinking groups (the content of unsaturated double bonds capable of free radical polymerization by iodine titration) in the adhesive polymer per 1g is preferably 0.1 to 10.0 mmol, more preferably 1.0 to 7.0 mmol, and even more preferably 2.0 to 5.5 mmol.

[0783] Hereinafter, specific examples 1 to 11 of adhesive polymers are shown, but the present invention is not limited to these. In the following illustrated compounds, the values ​​of each repeating unit (the values ​​of repeating units in the main chain) represent the molar percentage of the repeating unit. The values ​​of repeating units in the side chains represent the number of repetitions of the repeating site. Furthermore, Me represents methyl, Et represents ethyl, and Ph represents phenyl.

[0784] [Chemical Formula 61]

[0785]

[0786] [Chemical Formula 62]

[0787]

[0788] Regarding the molecular weight of the adhesive polymer, the weight-average molecular weight (Mw) is 2,000 or more, preferably 5,000 or more, and more preferably 10,000 to 300,000, based on the GPC-based polystyrene conversion value.

[0789] Depending on the requirements, hydrophilic polymers such as polyacrylic acid and polyvinyl alcohol as described in Japanese Patent Application Publication No. 2008-195018 can be used. Furthermore, lipophilic polymers and hydrophilic polymers can also be used.

[0790] The adhesive polymer can be used alone or in combination with two or more.

[0791] In the total solids composition of the image recording layer, the content of the binder polymer is preferably 1 to 90% by mass, more preferably 5 to 80% by mass.

[0792] <Polymer compounds in particle form (polymer particles)>

[0793] The image recording layer preferably contains polymer particles. Polymer particles help improve on-machine developability. Preferably, the polymer particles are polymer particles capable of converting the image recording layer into a hydrophobic state upon application of heat. The polymer particles are preferably selected from at least one of hydrophobic thermoplastic polymer particles, thermally reactive polymer particles, polymer particles with polymerizable groups, microcapsules containing hydrophobic compounds, and microgels (crosslinked polymer particles).

[0794] Examples of hydrophobic thermoplastic polymer particles include 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.

[0795] Specific examples of polymers constituting the hydrophobic thermoplastic polymer particles include homopolymers or copolymers of monomers such as ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, acrylates or methacrylates having a polyalkylene structure, or mixtures thereof. Copolymers comprising polystyrene, styrene, and acrylonitrile, and polymethyl methacrylate are preferred examples. The average particle size of the hydrophobic thermoplastic polymer particles is preferably 0.01 to 2.0 μm.

[0796] Examples of thermally reactive polymer particles include polymer particles with thermally reactive groups. These particles form hydrophobic regions through thermally reactive crosslinking and changes in functional groups during the crosslinking process.

[0797] The thermally reactive groups in polymer particles, if forming chemical bonds, can be functional groups capable of any reaction, and are preferably polymerizable groups. Examples include olefinic unsaturated groups (e.g., acryloyl, methacryl, vinyl, allyl, etc.) that undergo free radical polymerization, cationic polymerizable groups (e.g., vinyl, ethyleneoxy, epoxy, oxetyl, etc.), isocyanate groups or their blocks that undergo addition reactions, epoxy groups, ethyleneoxy groups, and functional groups with active hydrogen atoms that are the reactants of these (e.g., amino, hydroxyl, carboxyl, etc.), carboxyl groups that undergo condensation reactions and hydroxyl or amino groups that are the reactants, and acid anhydrides that undergo ring-opening addition reactions and amino or hydroxyl groups that are the reactants.

[0798] As microcapsules, examples include those described in Japanese Patent Application Publications Nos. 2001-277740 and 2001-277742, which contain all or a portion of the components of an image recording layer within the microcapsule. The components of the image recording layer may also be contained outside the microcapsule. A preferred embodiment of the image recording layer containing microcapsules is one in which a hydrophobic component is contained within the microcapsule, and a hydrophilic component is contained outside the microcapsule.

[0799] Microgels (cross-linked polymer particles) can contain at least one component of the image recording layer in their interior or on their surface. In particular, from the viewpoint of image forming sensitivity or brush resistance, reactive microgels are preferred by having free radical polymerizable groups on their surface.

[0800] To microencapsulate or microgel the components of this image recording layer, known methods can be used.

[0801] The average particle size of the microcapsules or microgels is preferably 0.01–3.0 μm, more preferably 0.05–2.0 μm, and particularly preferably 0.10–1.0 μm. Good resolution and stability over time can be obtained within this range.

[0802] Polymer particles can be used alone or in combination with two or more types.

[0803] In the total solids composition of the image recording layer, the content of polymer particles is preferably 5 to 90% by mass, more preferably 5 to 80% by mass, and even more preferably 10 to 75% by mass.

[0804] As a preferred embodiment, the polymer particles preferably have a hydrophobic backbone and contain the following two types of constituent units:

[0805] i) A constituent unit having a cyano side group directly bonded to the aforementioned hydrophobic main chain; and

[0806] ii) Constituents having side groups containing hydrophilic poly(epoxy) segments.

[0807] Acrylic resin chains are preferred as the hydrophobic backbone mentioned above.

[0808] Examples of the cyano side groups mentioned above are preferably -[CH2CH(C≡N)-] or -[CH2C(CH3)(C≡N)-].

[0809] Furthermore, the constituent units having the aforementioned side cyano groups can be readily derived from olefinic unsaturated monomers, such as acrylonitrile or methacrylonitrile, or combinations thereof.

[0810] Furthermore, the epoxide in the hydrophilic poly(epoxide) segment is preferably ethylene oxide or propylene oxide, and more preferably ethylene oxide.

[0811] The number of repeating epoxide structures in the above-mentioned hydrophilic poly(epoxide) segments is preferably 10 to 100, more preferably 25 to 75, and even more preferably 40 to 50.

[0812] As a resin particle having a hydrophobic main chain and comprising i) a constituent unit having a cyano side group directly bonded to the aforementioned hydrophobic main chain and ii) a constituent unit having a side group containing a hydrophilic poly(epoxy) segment, the particles described in paragraphs 0039 to 0068 of Japanese Patent Application Publication No. 2008-503365 are preferably examples.

[0813] As a preferred method, the polymer particles are preferably obtained by reacting with a polyisocyanate compound and a compound having active hydrogen, wherein the polyisocyanate compound is an adduct of a polyphenolic compound having two or more hydroxyl groups in the molecule and an isophorone diisocyanate.

[0814] The average particle size of the polymer particles is preferably 0.01–3.0 μm, more preferably 0.05–2.0 μm, and particularly preferably 0.10–1.0 μm. Good resolution and long-term stability can be obtained within this range.

[0815] Polymer particles can be used alone or in combination with two or more types.

[0816] In the total solids composition of the image recording layer, the content of polymer particles is preferably 5 to 90% by mass, more preferably 5 to 80% by mass, and even more preferably 10 to 75% by mass.

[0817] The polymeric compound contained in the image recording layer is preferably a polymeric compound containing structural units derived from styrene compounds and / or structural units derived from acrylonitrile compounds. From the viewpoint of improving on-machine developability, this polymeric compound can preferably be used as a binder polymer or polymer particles.

[0818] 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 preferred.

[0819] Examples of acrylonitrile compounds include acrylonitrile and methacrylonitrile, with acrylonitrile being the preferred choice.

[0820] In polymeric compounds containing styrene compounds and acrylonitrile compounds as structural units, the ratio of structural units derived from styrene compounds to structural units derived from acrylonitrile compounds is preferably 4:1 to 1:4.

[0821] (Chain transfer agent)

[0822] Chain transfer agents help improve the brush resistance of lithographic printing plates made from lithographic printing plate originals.

[0823] As a chain transfer agent, a thiol compound is preferred, and in terms of boiling point (low volatility), a thiol with 7 or more carbon atoms is more preferred, and a compound having a thiol group on an aromatic ring (aromatic thiol compound) is even more preferred. The thiol compound is preferably a monofunctional thiol compound.

[0824] Specific examples of chain transfer agents include the following compounds.

[0825] [Chemical Formula 63]

[0826]

[0827] [Chemical Formula 64]

[0828]

[0829] [Chemical Formula 65]

[0830]

[0831] [Chemical Formula 66]

[0832]

[0833] Chain transfer agents can be used alone or in combination with two or more.

[0834] In the total solids composition of the image recording layer, the content of chain transfer agent is preferably 0.01 to 50% by mass, more preferably 0.05 to 40% by mass, and even more preferably 0.1 to 30% by mass.

[0835] (sensitizer)

[0836] Sensitizers help improve the ink adhesion (hereinafter, also simply "ink adhesion") of ink in lithographic printing plates made from lithographic printing master plates. Examples of sensitizers include phosphorus compounds, nitrogen-containing low-molecular-weight compounds, and ammonium-containing polymers. In particular, when the lithographic printing master plate has a protective layer containing inorganic layered compounds, these compounds act as surface coating agents for the inorganic layered compounds, inhibiting the reduction in ink adhesion during printing caused by the inorganic layered compounds.

[0837] As a sensitizer, phosphonium compounds, nitrogen-containing low molecular weight compounds and ammonium-containing polymers are preferred, and phosphonium compounds, quaternary ammonium salts and ammonium-containing polymers are more preferred.

[0838] Regarding the sensitizer, the sensitizers described in International Publication No. 2020 / 137919,

[0151] to

[0155] , can be used.

[0839] In the total solids composition of the image recording layer, the content of the sensitizer is preferably 0.01 to 30% by mass, more preferably 0.1 to 15% by mass, and even more preferably 1 to 10% by mass.

[0840] (Other ingredients)

[0841] The image recording layer may contain surfactants, printing agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic particles, inorganic layered compounds, etc., as other components. Specifically, the aforementioned components described in paragraphs 0114 to 0159 of Japanese Patent Application Publication No. 2008-284817 may be used.

[0842] In the total solids composition of the image recording layer, the content of non-particulate polymeric compounds with a weight-average molecular weight of more than 15,000 is preferably 5% by mass or less, more preferably 4% by mass or less.

[0843] (Formation of the image recording layer)

[0844] The image recording layer can be formed, for example, by dispersing or dissolving the desired components appropriately in a known solvent to prepare a coating solution, as described in paragraphs 0142-0143 of Japanese Patent Application Publication No. 2008-195018, applying the coating solution using a known method such as a bar coater, and then drying it. The coating amount (solid content) of the coated and dried image recording layer varies depending on the application, but from the viewpoint of obtaining good sensitivity and good film properties of the image recording layer, 0.3 to 3.0 g / m² is preferred. 2 about.

[0845] From the viewpoint of imparting developability, the image recording layer preferably has water solubility or water dispersibility. Here, "water solubility" means that more than 0.1g dissolves in 100g of water at 20°C, and "water dispersibility" means that it is uniformly dispersed in water at 20°C.

[0846] The on-machine developing type lithographic printing plate master involved in this invention can have an undercoat layer (sometimes also called an intermediate layer) between the image recording layer and the support.

[0847] [Undercoat]

[0848] The undercoat layer enhances the adhesion between the support and the image recording layer in the exposed area and facilitates the peeling of the image recording layer from the support in the unexposed area, thus improving developability without compromising brush resistance. Furthermore, in the case of infrared laser exposure, the undercoat layer functions as a heat-insulating layer, thereby preventing the heat generated during exposure from diffusing to the support and reducing sensitivity.

[0849] Examples of compounds used in the primer coating include polymers having adsorbent and hydrophilic groups capable of adsorbing onto the surface of the support. To improve adhesion to the image recording layer, polymers having adsorbent, hydrophilic, and crosslinking groups are preferred. The compounds used in the primer coating can be low-molecular-weight compounds or polymers. Two or more compounds can be used in combination as needed.

[0850] 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.

[0851] The preferred adsorption groups for adsorption onto the support surface are phenolic hydroxyl groups, carboxyl groups, -PO3H2, -OPO3H2, -CONHSO2-, -SO2NHSO2-, and -COCH2COCH3. The preferred hydrophilic groups are sulfonyl groups or their salts, or carboxyl salts. The preferred crosslinking groups are acryloyl groups, methacryloyl groups, acrylamide groups, methacrylamide groups, allyl groups, etc.

[0852] 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 polar substituents and olefinic unsaturated bonds, and may further copolymerize with monomers other than those described above, preferably hydrophilic monomers.

[0853] 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. Also preferred are low-molecular-weight or high-molecular-weight compounds having crosslinking groups (preferably olefinic unsaturated bond groups), functional groups that interact with the support surface, and hydrophilic groups as described in Japanese Patent Application Publication Nos. 2005-238816, 2005-125749, 2006-239867, and 2006-215263.

[0854] As a more preferred polymer, examples include the polymers described in Japanese Patent Application Publication Nos. 2005-125749 and 2006-188038, which are polymers capable of adsorbing adsorption groups, having hydrophilic groups and crosslinking groups on the surface of a support.

[0855] In each 1g of polymer, the content of olefinic unsaturated groups in the polymer used in the primer coating is preferably 0.1 to 10.0 mmol, more preferably 0.2 to 5.5 mmol.

[0856] The weight-average molecular weight (Mw) of the polymer used in the primer coating is preferably 5,000 or more, more preferably 10,000 to 300,000.

[0857] In addition to the compounds used in the base coating, the base coating may also contain chelating agents, secondary or tertiary amines, polymerization inhibitors, amino groups or functional groups with polymerization inhibitory effects, and groups that interact with the surface of the support (e.g., 1,4-diazabicyclo[2.2.2]octane (DABCO), 2,3,5,6-tetrahydroxy-p-quinone, chloroquinone, sulfophthalic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylenediaminediacetic acid, hydroxyethyliminodiacetic acid, etc.) to prevent contamination over time.

[0858] The primer layer can be formed by applying and drying using known methods. The coating weight (solid content) of the dried primer layer is preferably 0.1–100 mg / m³. 2 More preferably 1–30 mg / m³ 2 .

[0859] The on-machine developing type lithographic printing plate master involved in this invention may or may not have a protective layer on the image recording layer.

[0860] [Protective Layer]

[0861] In addition to inhibiting the formation of the image-forming barrier reaction by blocking oxygen, the protective layer also has the functions of preventing scratches in the image recording layer and preventing ablation during high-intensity laser exposure.

[0862] Protective layers with such properties are described, for example, in U.S. Patent No. 3,458,311 and Japanese Patent Publication No. 55-49729. As the low-oxygen-permeability polymer used in the protective layer, either a water-soluble polymer or a water-insoluble polymer can be appropriately selected, or two or more can be mixed as needed. Specifically, examples include polyvinyl alcohol resins (including polyvinyl alcohol and modified polyvinyl alcohol), polyvinylpyrrolidone, water-soluble cellulose derivatives, and poly(meth)acrylonitrile.

[0863] As for polyvinyl alcohol, polyvinyl alcohol with a saponification degree of 50% or more is preferred. The saponification degree of polyvinyl alcohol is preferably 60% or more, more preferably 70% or more, and even more preferably 85% or more. There is no particular upper limit to the saponification degree; it is acceptable as long as it is 100% or less.

[0864] The degree of saponification can be determined according to the method described in JIS K 6726:1994.

[0865] 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.

[0866] Among water-soluble polymers, polyvinyl alcohol resin is preferred.

[0867] To improve oxygen barrier properties, the protective layer preferably contains inorganic layered compounds. Inorganic layered compounds are particles with thin, flat, plate-like shapes, such as natural mica, synthetic mica, talc (represented by the formula 3MgO·4SiO·H2O), monzocarp, montmorillonite, saponite, lithium montmorillonite, zirconium phosphate, etc.

[0868] The preferred inorganic layered compound is a mica compound. Examples of mica compounds include: A(B, C). 2-5 D4O 10(OH, F, O)₂ [where A is any one of K, Na, or Ca; B and C are any one of Fe(II), Fe(III), Mn, Al, Mg, or V; and D is Si or Al.] represents natural mica, synthetic mica, and other mica groups.

[0869] Within the mica group, natural mica includes muscovite, sodium mica, phlogopite, biotite, and scaly mica. Synthetic mica includes fluorophlogopite KMg3(AlSi3O4). 10 F2, potassium tetrasilica KMg 2.5 (Si4O) 10 Non-swellable mica such as F2 and Na tetrafluorosilica NaMg 2.5 (Si4O) 10 F2, Na or Li with mica (Na, Li) Mg2Li (Si4O) 10 F2, montmorillonite series Na or Li lithium montmorillonite (Na, Li) 1 / 8 Mg 2 / 5 Li 1 / 8 (Si4O) 10 F2 and other swelling mica, etc. Moreover, synthetic green soil is also very useful.

[0870] Among mica compounds, fluorine-based swelling mica is particularly useful. That is, swelling synthetic mica has a layered structure consisting of unit lattice layers approximately 10–15 Å thick, with significant metal atom substitution within the lattice compared to other clay minerals. As a result, the lattice layers are deficient in positive charge; to compensate for this, Li is adsorbed between the layers. + Na + Ca 2+ Mg 2+ Isocations. These interlayer cations are called exchangeable cations and can exchange with various cations. In particular, the interlayer cation is Li. + Na + In this state, the ionic radius is small, resulting in weak bonding between the layered lattice layers, leading to significant swelling upon contact with water. If shear force is applied in this state, it easily splits, forming a stable sol in water. This tendency is particularly strong in synthetic mica with swelling properties, making it especially preferred.

[0871] Regarding the shape of the mica compound, from the viewpoint of controlling diffusion, the thinner the thickness, the better; however, as long as it does not impede the smoothness of the coating surface or the transmissibility of activated light, the larger the planar dimension, the better. Therefore, the aspect ratio is preferably 20 or more, more preferably 100 or more, and particularly preferably 200 or more. The aspect ratio is the ratio of the major axis to the thickness of the particle, and can be measured, for example, from the projection of a particle-based microscopic photograph. The larger the aspect ratio, the greater the effect obtained.

[0872] Regarding the particle size of the mica compound, its average major diameter is preferably 0.3–20 μm, more preferably 0.5–10 μm, and particularly preferably 1–5 μm. The average thickness of the particles is preferably 0.1 μm or less, more preferably 0.05 μm or less, and particularly preferably 0.01 μm or less. Specifically, for example, in the case of swollen synthetic mica as a representative compound, as a preferred method, the thickness is 1–50 nm, and the planar dimension (major diameter) is about 1–20 μm.

[0873] The content of the inorganic layered compound relative to the total solids content of the protective layer is preferably 0 to 60% by mass, more preferably 3 to 50% by mass. Even when multiple inorganic layered compounds are used together, the total amount of inorganic layered compounds is preferably at the above-mentioned content. Within the above range, oxygen barrier properties are improved, and good sensitivity can be obtained. Furthermore, it is possible to prevent a decrease in ink adhesion.

[0874] The preferred content of the inorganic layered compound is 0.01–100 mg / m³. 2 More preferably 5–80 mg / m³ 2 Especially preferred is 5-50 mg / m³ 2 .

[0875] The protective layer may contain known additives such as plasticizers for imparting flexibility, surfactants for improving coatability, and inorganic microparticles for controlling surface slippage. Furthermore, the protective layer may contain sensitizers described in the image recording layer.

[0876] The protective layer can be formed by coating and drying using known methods. The coating weight (solid content) of the dried protective layer is preferably 0.01–10 g / m². 2 More preferably, it is 0.02–3 g / m 2 The preferred concentration is 0.02–1 g / m³. 2 .

[0877] The on-machine developing type lithographic printing plate master involved in this invention may have a collapsed edge shape at the end.

[0878] Figure 3 This is a schematic diagram showing the cross-sectional shape of the end of the original lithographic printing plate.

[0879] exist Figure 3In the original lithographic printing plate 1, there is a collapsed edge 2 at the end. The distance X from the upper end of the end face 1c of the original lithographic printing plate 1 (the boundary point between the collapsed edge 2 and the end face 1c) to the intersection of the extension line of the end face 1c and the extension line of the image recording layer (or the protective layer if a protective layer is formed) 1a is called the "collapse amount X". The distance Y from the point where the collapsed edge starts from the image recording layer 1a of the original lithographic printing plate 1 to the above intersection point is called the "collapse width Y".

[0880] In the shape of the collapsed edge at the end, the collapsed edge amount X is preferably 25 μm or more, more preferably 35 μm or more, and even more preferably 40 μm or more. From the viewpoint of preventing the degradation of on-machine developability caused by the degradation of the end surface condition, the upper limit of the collapsed edge amount X is preferably 150 μm. If the on-machine developability deteriorates, ink may sometimes adhere to the residual image recording layer, becoming a cause of edge contamination. If the collapsed edge amount X is too small, the ink adhering to the end may sometimes easily transfer to the blanket, becoming a cause of edge dirt. When the collapsed edge amount X is in the range of 25 to 150 μm, if the collapsed edge width Y is small, the occurrence of cracks at the end may increase, and the printing ink may accumulate in the cracks, becoming a cause of edge dirt. From this viewpoint, the collapsed edge width Y is preferably in the range of 70 to 300 μm, more preferably in the range of 80 to 250 μm. In addition, the above-mentioned ranges of collapsed edge amount and collapsed edge width are independent of the edge shape of the support surface 1b of the lithographic printing plate 1.

[0881] Typically, at the end of the original lithographic printing plate 1, the boundary B between the image recording layer and the support, as well as the support surface 1b, also experience edge collapse, similar to the image recording layer 1a.

[0882] The formation of the end with the aforementioned collapsed edge shape can be achieved, for example, by adjusting the cutting conditions of the original lithographic printing plate.

[0883] Specifically, this can be achieved by adjusting the gap, engagement amount, and blade tip angle of the upper and lower cutting blades in the longitudinal cutting device used when cutting the original lithographic printing plate.

[0884] Figure 4This is a conceptual diagram illustrating an example of the cutting section of a slitting device. The slitting device has a pair of upper and lower cutting blades 10 and 20 arranged vertically. The cutting blades 10 and 20 are composed of circular blades on a circular plate. The upper cutting blades 10a and 10b are supported coaxially by a rotating shaft 11, and the lower cutting blades 20a and 20b are each supported coaxially by a rotating shaft 21. The upper cutting blades 10a and 10b rotate in opposite directions to the lower cutting blades 20a and 20b. The lithographic printing plate 30 is cut to a predetermined width between the upper and lower cutting blades 10a and 10b and the lower cutting blades 20a and 20b. By adjusting the gaps between the upper and lower cutting blades 10a and 20a and between the upper and lower cutting blades 10b of the cutting section of the slitting device, an end with a collapsed edge shape can be formed.

[0885] In the machine-developable lithographic printing plate master according to the present invention, the arithmetic mean height Sa of the outermost surface on the side opposite to the side having the image recording layer is preferably 0.3 to 20 μm. Here, the side opposite to the side having the image recording layer refers to the side opposite to the side having the image recording layer, based on the aforementioned support.

[0886] In the machine-developable lithographic printing plate master according to the present invention, the arithmetic mean height Sa of the outermost surface of the side having the image recording layer is preferably 0.3 to 20 μm. Here, the side having the image recording layer refers to the side having the image recording layer based on the aforementioned support.

[0887] By providing an outermost surface with this characteristic, the on-machine developing type lithographic printing plate master according to the present invention exhibits excellent performance in preventing multiple plate feeding during the process of removing the master from the accumulation body, preventing scratches caused by the protrusions applied to the outermost surface of the master, and preventing development delays caused by the protrusions applied to the outermost surface of the master, even when the master is accumulated without inserting backing paper between master plates (also known as without backing paper).

[0888] Regarding the outermost surface of the side opposite to the side with the image recording layer, if the opposite side has a back coating, it is the surface of the back coating; if the opposite side does not have a layer, it is the surface of the support.

[0889] For example, in the case of forming the protrusions described later, the original lithographic printing plate may have the aforementioned back coating as the outermost layer and have a plurality of protrusions containing a polymer compound on the aforementioned back coating, or the aforementioned support body may have the aforementioned support body as the outermost layer and have a plurality of protrusions containing a polymer compound on the aforementioned support body.

[0890] When the image recording layer or the protective layer is the outermost layer, the outermost surface of the side with the image recording layer is the surface of the image recording layer or the surface of the protective layer.

[0891] For example, in the case of forming the protrusions described later, the original lithographic printing plate may have the aforementioned image recording layer or protective layer as the outermost layer, and the aforementioned image recording layer or protective layer has a plurality of protrusions containing polymeric compounds.

[0892] The arithmetic mean height Sa of the outermost surface on the side opposite to the side having the image recording layer is more preferably 0.5 to 10 μm, and even more preferably 0.5 to 7 μm.

[0893] The arithmetic mean height Sa of the outermost surface on the side having the image recording layer is more preferably 0.5 to 10 μm, and even more preferably 0.5 to 7 μm.

[0894] The arithmetic mean height Sa on the outermost surface was determined according to the method described in ISO 25178. Specifically, a Micromap MM3200-M100 manufactured by Ryoka Systems Inc. was used, and measurements were taken at least three locations selected from the same sample. The average of these measurements was taken as the arithmetic mean height Sa. Regarding the measurement range, a 500 μm × 500 μm area randomly selected from the sample surface was used for measurement.

[0895] In order to achieve the necessary condition that the arithmetic mean height Sa of the outermost surface is 0.3 to 20 μm, it is preferable to form an outermost layer with an uneven shape.

[0896] Specifically, examples include a method where the outermost layer contains particles with an average particle size of 0.5–20 μm (method 1) and a method where the outermost layer has multiple protrusions containing a polymeric compound as the main component (method 2). Here, the main component refers to the component with the highest content (mass %).

[0897] In Method 1, there is no particular limitation on the particles with an average particle size of 0.5 to 20 μm, but it is preferred to select at least one type of particle from organic resin particles and inorganic particles.

[0898] As a particle, the particles described in International Publication Nos. 2022-138880,

[0150] to

[0166] , can be used.

[0899] In Method 1, the average particle size of the above-mentioned particles is preferably 0.5 to 10 μm, more preferably 0.5 to 5 μm.

[0900] The average particle size refers to the volume average particle size, which is determined using a laser diffraction / scattering particle size analyzer. Specifically, for example, it is measured using a particle size distribution measuring device, the "Microtrac MT-3300II" (manufactured by Nikkiso Co., Ltd.).

[0901] Unless otherwise specified, the average particle size of other particles is also determined using the methods described above.

[0902] In Method 1, the in-plane density of particles with an average particle size of 0.5–20 μm is preferably 10,000 particles / mm². 2 The following is preferred: In-plane density is 100–5000 particles / mm². 2 Further preferred is 100–3000 pieces / mm 2 .

[0903] In-plane density can be determined by observing the surface of the lithographic printing plate master using a scanning electron microscope (SEM). Specifically, the number of particles can be counted at five locations on the surface of the lithographic printing plate master using a scanning electron microscope (SEM), and converted into density per mm. 2 The number of particles in the field of view is calculated by taking the average value.

[0904] The outermost layer on the side opposite to the side having the image recording layer preferably contains a binder in addition to particles with an average particle size of 0.5 to 20 μm.

[0905] As an adhesive, it is preferred to contain at least one phenolic varnish resin selected from phenol-formaldehyde resin, m-cresol-formaldehyde resin, p-cresol-formaldehyde resin, m / p mixed cresol-formaldehyde resin, phenol / cresol (which can be any one of m, p, or m / p mixture) mixed formaldehyde resin, or methyl phenolic resin, pyrogallol, acetone resin, epoxy resin, saturated copolyester resin, phenoxy resin, polyvinyl alcohol acetal resin, vinylidene chloride copolymer resin, polybutene, polybutadiene, polyamide, unsaturated copolyester resin, polyurethane, polyurea, polyimide, polysiloxane, polycarbonate, epoxy resin, chlorinated polyethylene, alkylphenol aldehyde condensation resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, carboxylated vinylidene polymer, acrylic resin copolymer resin, hydroxycellulose, hydroxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, cellulose acetate, methylcellulose, and carboxymethylcellulose. To prevent concerns about dissolution in the dampening solution during on-machine development, a water-insoluble resin is preferred.

[0906] Furthermore, the adhesive described above preferably contains at least one selected from the group consisting of polyurethane, acrylic resin, polystyrene, and polyethylene.

[0907] Furthermore, in the above-described method 1, it is preferable that the particles and the adhesive each independently contain at least one selected from the group consisting of polyurethane, acrylic resin, polystyrene, and polyethylene.

[0908] In addition to the aforementioned particles and adhesive, the outermost layer on the side opposite to the side having the image recording layer may also contain other components. Examples of such other components include known additives, such as surfactants.

[0909] The thickness of the outermost layer on the side opposite to the side having the image recording layer is preferably 0.5 to 10 μm, more preferably 0.5 to 5 μm, and even more preferably 0.5 to 3 μm.

[0910] As in Method 2, the polymeric compound comprising multiple protrusions with a polymeric compound as the main component is preferably selected from at least one polymeric compound from the group consisting of phenolic formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m / p mixed cresol formaldehyde resin, phenol / cresol (which may be any one of m, p, or m / p mixture) mixed formaldehyde resin, or methyl phenolic resin, pyrogallol acetone resin, epoxy resin, saturated copolyester resin, phenoxy resin, polyvinyl alcohol acetal resin, vinylidene chloride copolymer resin, polybutene, polybutadiene, polyamide, unsaturated copolyester resin, polyurethane, polyurea, polyimide, polysiloxane, polycarbonate, epoxy resin, chlorinated polyethylene, alkylphenol aldehyde condensation resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, carboxyethylene polymer, acrylic resin copolymer resin, hydroxycellulose, hydroxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, cellulose acetate, methylcellulose, and carboxymethylcellulose.

[0911] From the viewpoint of maintaining excellent reproducibility even when the detached protrusions move to the image recording layer, water-soluble polymers are more preferred. Specifically, examples include polyacrylates, carboxyethylene polymers, acrylic resin copolymers, hydroxycellulose, hydroxymethylcellulose, polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, cellulose acetate, methylcellulose, and carboxymethylcellulose.

[0912] As a modified polyvinyl alcohol, acid-modified polyvinyl alcohol having carboxyl or sulfonyl groups is preferred. Specifically, the modified polyvinyl alcohol described in Japanese Patent Application Publication Nos. 2005-250216 and 2006-259137 is preferred.

[0913] There are no particular restrictions on the shape and height of the protrusion, but the arithmetic mean height Sa is preferably 0.3 to 20 μm.

[0914] There are no particular limitations on the method for forming strip-shaped protrusions (striped coatings), but they can be easily formed by coating a composition comprising at least one of the following groups: bar coating, inkjet printing, gravure printing, screen printing, spraying, and slot die coating.

[0915] There are no particular limitations on the method for forming dot-like protrusions (dot coating film), but it can be easily formed by coating a composition comprising at least one of the following groups of particles and polymeric compounds using at least one of the following methods selected from the group consisting of spraying, inkjet printing and screen printing.

[0916] There are no particular limitations on the method for forming the dotted line protrusions (dotted line coating), but it can be easily formed by coating a composition comprising at least one of the groups consisting of particles and polymeric compounds by at least one of the methods selected from inkjet printing and screen printing.

[0917] As the adhesive included in the outermost layer in Method 2, examples include the same polymer compound as that included in the aforementioned protrusions, and the preferred method is also the same.

[0918] In method 2, from the viewpoint of preventing the protrusions from detaching, it is preferable that the adhesive contained in the outermost layer and the polymer compound contained in the protrusions contain the same type of resin. Here, "same type of resin" means that the resins such as polyurethane, acrylic resin, polystyrene, and polyethylene are the same type, and all structural units in the resin do not need to be the same.

[0919] [Methods for making printing plates]

[0920] The method for manufacturing the printing plate according to the present invention will be described using the lithographic printing plate original according to the present invention. The method for manufacturing the printing plate includes: a step of exposing the lithographic printing plate original to an image (exposure step); and a step of removing the unexposed portion of the image recording layer from the image-exposed lithographic printing plate original on a printing press by printing ink and dampening solution at least one of them (on-machine development step).

[0921] [Exposure process]

[0922] Image exposure is preferably performed by scanning and exposing digital data using methods such as infrared lasers.

[0923] The wavelength of the exposure light source is preferably in the range of 750 to 1,400 nm. Solid-state lasers and semiconductor lasers that radiate infrared radiation are preferred as light sources with a wavelength of 750 nm to 1,400 nm. The exposure mechanism can be any of the following: internal drum type, external drum type, flat plate type, etc.

[0924] The exposure process can be performed using a plate-making machine or other known methods. Furthermore, a printing press equipped with an exposure device can be used, where the lithographic printing plate is mounted on the press, and the image is exposed on the press.

[0925] [On-machine developing process]

[0926] In the on-machine developing process, if the original lithographic printing plate is supplied with printing ink and dampening solution and printing begins without any developing treatment of the plate after image exposure, the unexposed portion of the original lithographic printing plate is removed in the early stages of printing, thereby exposing the surface of the hydrophilic support and forming a non-image area. Known lithographic printing inks and dampening solutions can be used as the printing ink and dampening solution. Either printing ink or dampening solution can be initially supplied to the surface of the original printing plate, but from the viewpoint of preventing contamination of the image recording layer components from which the dampening solution has been removed, it is preferable to initially supply printing ink.

[0927] In this way, the original lithographic printing plate is developed on the offset printing press and used directly in multiple printings.

[0928] In addition to the steps described above, the method for making printing plates according to the present invention may also include other known steps. Examples of other steps include, for instance, a plate inspection step that confirms the position or orientation of the original lithographic printing plate before each step, and a confirmation step that confirms the printed image after the on-machine developing step.

[0929] Example

[0930] The present invention will now be described in detail through examples, but the invention is not limited thereto. In the examples, unless otherwise specified, "%" and "parts" refer to "mass %" and "parts by mass," respectively. In polymer compounds, unless specifically specified, molecular weight is weight-average molecular weight (Mw), and the ratio of repeating structural units is molar percentage. Weight-average molecular weight (Mw) is a value determined based on gel permeation chromatography (GPC) as a polystyrene equivalent.

[0931] [Examples 1 to 67 and Comparative Examples 1 to 2]

[0932] <Fabrication of Support Body 1>

[0933] The support body 1 was manufactured by performing the following (Ja) to (Jm) processes on an aluminum plate (aluminum alloy plate) of material 1S with a thickness of 0.3 mm. In addition, a water washing process was performed between all processing steps, and the liquid was drained by clamping rollers after the water washing process.

[0934] (Ja) Mechanical roughening treatment (brush texture method)

[0935] Use such as Figure 5 The apparatus shown contains a suspension of pumice powder (specific gravity 1.1 g / cm³). 3 While being supplied to the surface of the aluminum plate as a polishing slurry, it undergoes mechanical roughening treatment via a rotating bristle brush. Figure 5 In the diagram, 31 is an aluminum plate, 32 and 34 are roller brushes (in this embodiment, they are stiff bristle brushes), 33 is grinding slurry, and 35, 36, 37 and 38 are support rollers.

[0936] In the mechanical roughening process, the median particle size (μm) of the abrasive material was set to 30μm, the number of brushes was set to 4, and the brush rotation speed (rpm) was set to 250rpm. The stiff bristle tuft brush was made of 6 / 10 nylon, with bristle diameter of 0.3mm and bristle length of 50mm. The brush was constructed by drilling holes and densely packing bristles into a φ300mm stainless steel sleeve. The distance between the two support rollers (φ200mm) at the bottom of the stiff bristle tuft brush was 300mm. The load on the drive motor that pressed the stiff bristle tuft brush until it rotated was increased by 10kW compared to the load before pressing the brush against the aluminum plate. The rotation direction of the brush was the same as the movement direction of the aluminum plate.

[0937] (Jb) Alkali etching treatment

[0938] 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) at 70°C using a sprayer. The aluminum dissolution rate on the surface after electrochemical roughening was then 10 g / m². 2 .

[0939] (Jc) used acidic aqueous solution for decontamination treatment.

[0940] Waste nitric acid used in the next electrochemical roughening process, which involves spraying the aluminum plate with a liquid temperature of 35°C for 3 seconds using a sprayer, was used as an acidic aqueous solution for decontamination.

[0941] (Jd) underwent electrochemical roughening treatment using an aqueous nitric acid solution.

[0942] Electrochemical roughening treatment was performed continuously using a 60Hz AC voltage. The electrolyte was an aqueous solution of 10.4 g / L nitric acid with aluminum nitrate added to adjust the aluminum ion concentration to 4.5 g / L, and the solution temperature was 35°C. The AC power supply waveform is as follows. Figure 1 The waveform shown, with a current value reaching its peak value from zero in 0.8 msec (tp), a duty ratio of 1:1, and a trapezoidal rectangular wave AC current, was used. The carbon electrode was electrochemically roughened as the counter electrode. Ferrite was used as the auxiliary anode. Regarding the electrolytic cell, [the following is a description of the process:] A [specific type of electrolytic cell was used]. Figure 2 The electrolytic cell shown. The current density, expressed as peak current, is 30 A / dm³. 2 This causes 5% of the current flowing from the power source to be diverted to the auxiliary anode. (Electricity (C / dm³)) 2 The total charge during the reaction with the aluminum plate as the anode is 185 C / dm. 2 .

[0943] (Je) Alkali etching treatment

[0944] Etching was performed on an aluminum plate by spraying an aqueous solution of caustic soda (27% by mass) and aluminum ions (2.5% by mass) onto the plate at 50°C using a sprayer. The aluminum dissolution rate was 3.5 g / m². 2 .

[0945] (Jf) used acidic aqueous solution for decontamination treatment.

[0946] The aluminum plate was treated with an acidic aqueous solution containing 30°C sulfuric acid, 170 g / L sulfuric acid, and 5 g / L aluminum ions by spraying it with a sprayer for 3 seconds.

[0947] (Jg) underwent electrochemical roughening treatment using hydrochloric acid aqueous solution.

[0948] Electrochemical roughening treatment was performed continuously using a 60Hz AC voltage. The electrolyte was an aqueous solution of 6.2 g / L hydrochloric acid with aluminum chloride added to adjust the aluminum ion concentration to 4.5 g / L at a temperature of 35°C. The AC power supply waveform was as follows. Figure 1 The waveform shown, with a current value reaching its peak value from zero in 0.8 msec (tp), a duty ratio of 1:1, and a trapezoidal rectangular wave AC current, was used. The carbon electrode was electrochemically roughened as the counter electrode. Ferrite was used as the auxiliary anode. Regarding the electrolytic cell, [the following is a description of the process:] A [specific type of electrolytic cell was used]. Figure 2 The electrolytic cell shown is operated at a current density of 25 A / dm³, expressed as the peak current. 2 The amount of electricity generated during hydrochloric acid electrolysis (C / dm³) 2 The total charge during the reaction with the aluminum plate as the anode is 63 C / dm. 2 .

[0949] (Jh) Alkali etching treatment

[0950] Etching was performed on an aluminum plate by spraying an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) onto the plate at 60°C using a sprayer. The aluminum dissolution rate was 0.2 g / m². 2 .

[0951] (Ji) used acidic aqueous solution for decontamination treatment.

[0952] The waste liquid (sulfuric acid concentration of 170 g / L and aluminum ion concentration of 5 g / L) generated during the anodizing process at a liquid temperature of 35°C was sprayed onto the aluminum plate with a sprayer for 4 seconds to serve as an acidic aqueous solution for decontamination treatment.

[0953] (Jj) Stage 1 Anodizing Treatment

[0954] Using based Figure 6 The DC electrolytic anodizing apparatus shown underwent the first stage of anodizing. A 170 g / L sulfuric acid aqueous solution was used as the electrolyte, and the conditions were: a liquid temperature of 50°C and a current density of 30 A / dm³. 2 Anodizing was performed under specific conditions, resulting in a film thickness of 0.3 g / m². 2 The anodic oxide film.

[0955] (Jk) Hole Enlargement Treatment

[0956] Anodized aluminum plates were immersed in a sodium hydroxide aqueous solution containing 5% by mass of caustic soda and 0.5% by mass of aluminum ions at 40°C for 3 seconds to enlarge holes.

[0957] (Jl) Stage 2 Anodizing Treatment

[0958] Using based Figure 6 The DC electrolytic anodizing apparatus shown underwent the second stage of anodizing. A 170 g / L sulfuric acid aqueous solution was used as the electrolyte, at a liquid temperature of 50°C and a current density of 13 A / dm³. 2 Anodizing was performed under specific conditions, resulting in a film thickness of 2.1 g / m³. 2 The anodic oxide film.

[0959] (Jm) Hydrophilic treatment

[0960] To ensure the hydrophilicity of the non-image area, the aluminum plate was subjected to silicate treatment by immersing it in a 2.5% by mass sodium silicate solution (No. 3) at 50°C for 7 seconds. The Si deposition rate was 8.5 mg / m². 2 The average diameter of the micropores is 30 nm.

[0961] The value of lightness L* in the L*a*b* color system of the anodic oxide film surface of support 1 is 72.3.

[0962] <Fabrication of Support Body 2>

[0963] The support body 2 was manufactured by performing the following treatments (Fa) to (Fg) on ​​an aluminum plate (aluminum alloy plate) of material 1S with a thickness of 0.3 mm. In addition, a water washing process was performed between all processing steps, and the liquid was drained by clamping rollers after the water washing process.

[0964] (Fa) Alkali etching treatment

[0965] 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) at 70°C using a sprayer. The aluminum dissolution rate on the surface after electrochemical roughening was then 5 g / m². 2 .

[0966] (Fb) was treated with an acidic aqueous solution for decontamination.

[0967] The aluminum plate was treated with an acidic solution containing 30°C sulfuric acid at a concentration of 150g / L by spraying it with a sprayer for 3 seconds.

[0968] (Fc) Electrochemical roughening treatment

[0969] 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, employing alternating current. The electrolyte temperature was 30°C. The aluminum ion concentration was adjusted by adding aluminum chloride.

[0970] 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 stages. A carbon electrode was used as the counter electrode in the aluminum plate.

[0971] (Fd) Alkali etching treatment

[0972] Etching was performed on an aluminum plate by spraying an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) onto the plate at 45°C using a sprayer. The dissolved aluminum content on the surface after electrochemical roughening was 0.2 g / m². 2 .

[0973] (Fe) was treated with an acidic aqueous solution for decontamination.

[0974] The aluminum plate was treated with an acidic aqueous solution containing 35°C sulfuric acid at a concentration of 170 g / L and 5 g / L aluminum ions by spraying it with a sprayer for 3 seconds.

[0975] (Ff) Stage 1 Anodizing Treatment

[0976] Using based Figure 6 The DC electrolytic anodizing apparatus shown was used for the first stage of anodizing. A 150 g / L phosphoric acid aqueous solution was used as the electrolyte, and the conditions were: a liquid temperature of 35°C and a current density of 4.5 A / dm³. 2 Anodizing was performed under specific conditions, resulting in a film thickness of 1 g / m³. 2 The anodic oxide film.

[0977] exist Figure 6 In the anodizing apparatus 410 shown, such as Figure 6 The aluminum plate 416 is conveyed as indicated by the middle arrow. In the power supply tank 412 containing electrolyte 418, the aluminum plate 416 becomes positively charged via the power supply electrode 420. Furthermore, the aluminum plate 416 is conveyed upwards in the power supply tank 412 by roller 422, then downwards by clamping roller 424, and finally conveyed towards the electrolytic treatment tank 414 containing electrolyte 426, and then horizontally by roller 428. Next, the aluminum plate 416 becomes negatively charged via the electrolytic electrode 430, thereby forming an anodized film on its surface. The aluminum plate 416, leaving the electrolytic treatment tank 414, is then conveyed to the subsequent process. In the aforementioned anodizing apparatus 410, a direction-changing mechanism is formed by rollers 422, clamping rollers 424, and rollers 428. In the inter-tank section between the power supply tank 412 and the electrolytic treatment tank 414, aluminum plates 416 are conveyed in a mountain-shaped and inverted U-shaped configuration via rollers 422, 424, and 428. The power supply electrode 420 and the electrolytic electrode 430 are connected to a DC power supply 434.

[0978] (Fg) Stage 2 Anodizing Treatment

[0979] Using based Figure 6 The DC electrolytic anodizing apparatus shown underwent the second stage of anodizing. A 170 g / L sulfuric acid aqueous solution was used as the electrolyte, at a liquid temperature of 50°C and a current density of 13 A / dm³. 2 Anodizing was performed under specific conditions, resulting in a film thickness of 2.1 g / m³. 2 An anodized film was formed. Then, a spray-based water wash was performed. The average diameter of the micropores in support 2 was 40 nm.

[0980] The value of lightness L* in the L*a*b* color system of the anodic oxide film surface of support 2 is 83.7.

[0981] <Fabrication of Support Body 3>

[0982] The support body 3 was manufactured by performing the following (Fa) to (Ff) processes on an aluminum plate (aluminum alloy plate) of material 1S with a thickness of 0.3 mm. In addition, a water washing process was performed between all processing steps, and the liquid was drained by clamping rollers after the water washing process.

[0983] (Fa) Alkali etching treatment

[0984] 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) at 70°C using a sprayer. The aluminum dissolution rate on the surface after electrochemical roughening was then 5 g / m². 2 .

[0985] (Fb) was treated with an acidic aqueous solution for decontamination.

[0986] The aluminum plate was treated with an acidic solution containing 30°C sulfuric acid at a concentration of 150g / L by spraying it with a sprayer for 3 seconds.

[0987] (Fc) Electrochemical roughening treatment

[0988] 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, employing alternating current. The electrolyte temperature was 30°C. The aluminum ion concentration was adjusted by adding aluminum chloride.

[0989] 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 stages. A carbon electrode was used as the counter electrode in the aluminum plate.

[0990] (Fd) Alkali etching treatment

[0991] Etching was performed on an aluminum plate by spraying an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) onto the plate at 45°C using a sprayer. The dissolved aluminum content on the surface after electrochemical roughening was 0.2 g / m². 2.

[0992] (Fe) was treated with an acidic aqueous solution for decontamination.

[0993] The aluminum plate was treated with an acidic aqueous solution containing 35°C sulfuric acid at a concentration of 170 g / L and 5 g / L aluminum ions by spraying it with a sprayer for 3 seconds.

[0994] (Ff) Stage 1 Anodizing Treatment

[0995] Using based Figure 6 The DC electrolytic anodizing apparatus shown was used for the first stage of anodizing. A 150 g / L phosphoric acid aqueous solution was used as the electrolyte, and the conditions were: a liquid temperature of 35°C and a current density of 4.5 A / dm³. 2 Anodizing was performed under specific conditions, resulting in a film thickness of 1 g / m³. 2 The anodic oxide film.

[0996] The average diameter of the micropores in the support 3 is 40 nm.

[0997] The value of lightness L* in the L*a*b* color system of the anodic oxide film surface of the support 3 is 82.4.

[0998] <Fabrication of Support Body 4>

[0999] The support 4 was manufactured in accordance with the manufacturing method of the support in Example 5 of International Publication No. 2021 / 67054.

[1000] <Forming of base coating 1>

[1001] On the support, the primer coating liquid (1) with the following composition is applied at a dry coating amount of 26 mg / m². 2 The base coat 1 is formed by applying it in a certain way.

[1002] (Base coat coating liquid (1))

[1003] • Compound (2) for primer coating (structure below) 0.013 parts

[1004] 0.005 parts of hydroxyethyliminodiacetic acid

[1005] 0.005 parts of tetrasodium ethylenediaminetetraacetate

[1006] · 0.0003 parts of polyoxyethylene lauryl ether

[1007] ·Water 3.15 parts

[1008] [Chemical Formula 67]

[1009]

[1010] The values ​​on the lower right side of the brackets of each structural unit in the above-mentioned base coating compound (2) represent the mass ratio, and the values ​​on the lower right side of the brackets of the ethoxy group represent the number of repetitions.

[1011] <Forming of base coating 2>

[1012] On the support, the primer coating liquid (2) with the following composition is applied at a dry coating weight of 0.03 g / m. 2 The base coat 2 is formed by applying it in a certain way.

[1013] (Base coat liquid (2))

[1014] • Aqueous solution of polyacrylic acid (40% by mass)

[1015] Jurymer AC-10S (manufactured by Toagosei Company, Limited) 3.0 copies

[1016] Water 27.0 parts

[1017] <Formation of image recording layers 1-58, 61-62, 63-69>

[1018] After bar coating with the image recording layer coating solutions (image recording layer coating solutions (1) to (58), (61) to (62), (63) to (69)) of the following compositions, they were dried at 110°C for 40 seconds to form samples with a dry weight of 1.0 g / m³. 2 Image recording layers 1–58, 61–62, and 63–69. Furthermore, the amounts of the compounds listed in Table 1 were selected such that the dry weight corresponds to the listed content.

[1019] (Image recording layer coating solution)

[1020] ·2-Butanone: 5.3155 parts

[1021] ·1-Methoxy-2-propanol: 2.8825 parts

[1022] Methanol: 2.3391 parts

[1023] • Chromogenic compounds (listed in Table 1): Amounts listed in Table 1

[1024] • Hydrogen-donating compounds (as shown in Table 1): Amounts shown in Table 1

[1025] • Polymerizable compounds (listed in Table 1): Amounts listed in Table 1

[1026] • Electron-receiving polymerization initiators (as shown in Table 1): Amounts shown in Table 1

[1027] • Electron-donating polymerization initiators (as shown in Table 1): Amounts shown in Table 1

[1028] • Infrared absorber (as listed in Table 1): The amount listed in Table 1

[1029] • Acid colorant (as listed in Table 1): The amount listed in Table 1

[1030] Trimethylbenzene phosphate: 0.0125 parts

[1031] • Anionic surfactant (A-1): 0.0162 parts

[1032] • Microgel solution: 2.8779 parts

[1033] Fluorinated surfactant (W-1): 0.0042 parts

[1034] [Chemical Formula 68]

[1035]

[1036] The following shows the preparation method of the microgel used in the above microgel solution.

[1037] Preparation of polyisocyanate compounds-

[1038] A suspension of 17.78 parts (80 molar equivalents) of isophorone diisocyanate and 7.35 parts (20 molar equivalents) of polyphenol compound (1) represented by the following structural formula in ethyl acetate (25.31 parts) was stirred with 0.043 parts of tris(2-ethylhexanoate) bismuth (NEOSTANN U-600, manufactured by NITTO KASEI CO.,LTD.). The reaction temperature was set to 50°C at the moment when the exothermic reaction stopped, and the mixture was stirred for 3 hours to obtain an ethyl acetate solution (50% by mass) of polyisocyanate compound (1).

[1039] [Chemical Formula 69]

[1040]

[1041] -Preparation of microgels-

[1042] The following oil and aqueous phase components were mixed and emulsified using a homogenizer at 12,000 rpm for 10 minutes. The resulting emulsion was stirred at 45°C for 4 hours, and then 5.20 g of a 10% 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% by mass with distilled water to obtain an aqueous dispersion of microgels. The average particle size, determined by light scattering, was 0.28 μm.

[1043] ~Oil phase ingredients~

[1044] (Component 1) Ethyl acetate: 12.0 parts

[1045] (Component 2) An adduct (50% by mass ethyl acetate solution, manufactured by Mitsui Chemicals, Inc.) formed by adding trimethylolpropane (6 molar equivalents) to xylene diisocyanate (18 molar equivalents) and then adding it to mono-terminally methylated polyoxyethylene (1 molar equivalent, repeat number of oxyethylidene units: 90): 3.76 parts

[1046] (Component 3) Polyisocyanate compound (1) (as a 50% by mass ethyl acetate solution): 15.0 parts

[1047] (Component 4) 11.54 parts of 65% by weight ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartamer Company, Inc.)

[1048] (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.).

[1049] ~Aqueous phase components~

[1050] Distilled water: 46.87 parts

[1051] <Formation of image recording layers 59-60>

[1052] The image recording layer coating solutions (image recording layer coating solutions (59) to (60)) with the following compositions were applied to the rods and dried at 110°C for 40 seconds to form samples with a dry weight of 0.9 g / m². 2 Image recording layers 59-60. Furthermore, the amounts of the compounds listed in Table 1 were selected in such a way that the dry weight corresponds to the listed content.

[1053] (Image recording layer coating solution)

[1054] 1-Propanol 4.94 parts

[1055] ·2-Butanone: 2.40 parts

[1056] 0.14 parts of γ-butyrolactone

[1057] ·1-Methoxy-2-propanol: 4.22 parts

[1058] Water: 0.66 parts

[1059] Polymer dispersion *1 1,056 copies

[1060] Hydroxypropyl methylcellulose *2 0.600 copies

[1061] BYK 302 *3 0.18 copies

[1062] • Chromogenic compounds (listed in Table 1): Amounts listed in Table 1

[1063] • Hydrogen-donating compounds (as shown in Table 1): Amounts shown in Table 1

[1064] • Polymerizable compounds (as described in Table 1): Examples are listed in the table of examples.

[1065] • Electron-receiving polymerization initiators (as shown in Table 1): Amounts shown in Table 1

[1066] • Electron-donating polymerization initiators (as shown in Table 1): Amounts shown in Table 1

[1067] • Infrared absorber (as listed in Table 1): The amount listed in Table 1

[1068] • Acid colorant (as listed in Table 1): The amount listed in Table 1

[1069] *1: The polymer dispersion was prepared in accordance with the description in European Patent Application Publication No. 1765593 and used as a 23.5% by mass dispersion of n-propanol / water (80:20 [mass ratio]).

[1070] *2: 5.0% by mass aqueous solution

[1071] *3: 25% by mass 1-methoxy-2-propanol solution (manufactured by BykChemie)

[1072] [Chromatophoretic compounds]

[1073] The chromogenic compounds listed in Table 1 are as described above.

[1074] [Hydrogen-donating compounds]

[1075] The hydrogen-donating compounds listed in Table 1 are as described above.

[1076] [Polymerizing compounds]

[1077] The following lists the polymeric compounds described in Table 1.

[1078] M-1:

[1079] 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 (M-2). Molecular weight fractionation of urethane acrylate 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 14,000.

[1080] M-2:

[1081] A polymeric compound with a concentration of 80% by mass in a 2-butanone solution obtained by reacting DESMODUR (registered trademark) N100 with hydroxyethyl acrylate and pentaerythritol acrylate in a molar ratio of 1:1.5:1.5.

[1082] M-3:

[1083] Dipentaerythritol hexaacrylate (DPHA)

[1084] M-4:

[1085] Ethoxylated (4) pentaerythritol tetraacrylate "Sartomer SR494"

[1086] Electron-donating polymerization initiators

[1087] The following table lists the electron-donating polymerization initiators described in Table 1.

[1088] [Chemical Formula 70]

[1089]

[1090] Electron-receiving polymerization initiators

[1091] The following table lists the electron-accepting polymerization initiators.

[1092] [Chemical Formula 71]

[1093]

[1094] Infrared absorber

[1095] The following lists the infrared absorbers described in Table 1. These are compounds that are different from chromophores.

[1096] [Chemical Formula 72]

[1097]

[1098] [Acidic colorant]

[1099] The following lists the acidic color-developing agents described in Table 1. These are compounds that are different from color-developing compounds.

[1100] [Chemical Formula 73]

[1101]

[1102] [Chemical Formula 74]

[1103]

[1104] <Formation of protective layers 1-5>

[1105] After bar-coating the image recording layer with the protective coating solutions (protective coating solutions (1) to (5)) of the following compositions, drying at 120°C for 60 seconds resulted in a dry coating weight of 0.1 g / m². 2 The protective layer.

[1106] (Protective coating liquid)

[1107] • Inorganic layered compound dispersion (1) (below): Amounts recorded in Table 1

[1108] • Hydrophilic polymer (1) (structure below, Mw: 30,000): 0.03 parts

[1109] • METOLOSE SM04 (manufactured by Shin-Etsu Chemical Co., Ltd.): 0.0600 parts

[1110] • RAPISOL A-80 (80% aqueous solution) (manufactured by NOF CORPORATION): 0.0063 parts

[1111] Water: 2.0 parts

[1112] [Chemical Formula 75]

[1113]

[1114] (Preparation of Inorganic Layered Compound Dispersion (1))

[1115] 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 the mixture was dispersed using a homogenizer until the volume average particle size (laser scattering method) reached 3 μm. The aspect ratio of the obtained dispersed particles was greater than 100.

[1116] In the protective layer of Table 1, “layered compound” refers to “synthetic mica SOMASIF ME-100 (manufactured by Co-op Chemical Co., Ltd.)”, which is a component of the inorganic layered compound dispersion (1).

[1117] Furthermore, regarding the content of "inorganic layered compound dispersion (1)", the amount added was selected in such a way that the dry weight in the "content" section of Table 1 is the content recorded.

[1118] [Production of the original lithographic printing plate]

[1119] As described in Table 1, the original offset printing plates of Examples 1 to 74 and Comparative Examples 1 to 2 were produced by combining the above-mentioned support, base coating, image recording layer and protective layer.

[1120] [Table 1]

[1121]

[1122] [Table 2]

[1123]

[1124] [Table 3]

[1125]

[1126] [Table 4]

[1127]

[1128] [Table 5]

[1129]

[1130] [Table 6]

[1131]

[1132] The original lithographic printing plate obtained was evaluated as follows.

[1133] <Visual Recognition Assessment: Immediately After Exposure>

[1134] For the obtained lithographic printing original, a Luxel PLATESETTER T-6000III manufactured by Fujifilm Corporation, equipped with an 830nm infrared semiconductor laser, was used to achieve a wavelength of 110mJ / cm². 2 Exposure was performed using a specific exposure method, resulting in an exposed image containing both solid and non-image areas. Exposure was conducted at 25°C and 50% RH.

[1135] The color rendering of the original offset printing plate immediately after exposure was measured. For the measurement, a KonicaMinolta, Inc. CM2600d spectrophotometer and CM-S100W operating software were used, and the measurement was performed using the SCE (spot eccentricity elimination) method. Regarding color rendering properties, the L* values ​​(lightness) of the L*a*b* color system were used, and the difference ΔL between the L* values ​​of the exposed and unexposed areas was used for evaluation. A larger ΔL value indicates better color rendering.

[1136] <Visual recognition assessment: after storage in the dark>

[1137] For the obtained lithographic printing original, a Luxel PLATESETTER T-6000III manufactured by Fujifilm Corporation, equipped with an 830nm infrared semiconductor laser, was used to achieve a wavelength of 110mJ / cm². 2 Exposure was performed using a specific exposure method, resulting in an exposed image containing both solid and non-image areas. Exposure was conducted at 25°C and 50% RH.

[1138] After being exposed, the original lithographic printing plates were stored at 25°C, 50% RH, and in the dark for 72 hours, and the color development was measured. Additionally, other original lithographic printing plates were stacked on top of each other during storage, ensuring the exposed side of the original plate was not exposed to air. Measurements were performed using a Konica Minolta, Inc. CM2600d spectrophotometer and CM-S100W software, using the SCE (spot light emission) method. Color development was evaluated using the L* value (lightness) of the L*a*b* color system, based on the difference ΔL between the L* value of the exposed and unexposed areas. A larger ΔL value indicates better color development.

[1139] If ΔL is 3.5 or higher, it is set to the allowable range.

[1140] <Visual Recognition Evaluation: After White Light Exposure>

[1141] For the obtained lithographic printing original, a Luxel PLATESETTER T-6000III manufactured by Fujifilm Corporation, equipped with an 830nm infrared semiconductor laser, was used to achieve a wavelength of 110mJ / cm². 2 Exposure was performed using a specific exposure method, resulting in an exposed image containing both solid and non-image areas. Exposure was conducted at 25°C and 50% RH.

[1142] The original lithographic printing plate, after being exposed, was humidified for 1 hour in a dark environment at 25°C and 30% RH, and then exposed to a white fluorescent lamp with an illuminance of 800 Lux on the plate surface for 1 hour. The white lamp exposure was also conducted while maintaining the 25°C and 30% RH environment. The color development of the original lithographic printing plate after white lamp exposure was measured. The measurements were performed using a Konica Minolta, Inc. CM2600d spectrophotometer and CM-S100W operating software, using the SCE (spot eccentricity elimination) method. Color performance was evaluated using the L* value (lightness) of the L*a*b* color system, based on the difference ΔL between the L* value of the exposed and unexposed areas. A larger ΔL value indicates better color performance.

[1143] If ΔL is 3.5 or higher, it is set to the allowable range.

[1144] The results are shown in Table 1.

[1145] Regarding the original offset printing plates obtained, further evaluations were also made on "brush resistance" and "dampening solution contamination".

[1146] Furthermore, regarding the original offset printing plates obtained in Examples 1, 2, 8, 10-11, 38-40, 45, 55-57, and 65-73, the "sensor readability" was further evaluated as follows.

[1147] <Brush Resistance Evaluation>

[1148] Using a Kodak Magnus800 Quantum equipped with an infrared semiconductor laser, the original lithographic printing plate was exposed (equivalent to an irradiation energy of 110 mJ / cm²) at an output power of 27 W, an external drum speed of 450 rpm, and a resolution of 2,400 dpi (dots per inch, 1 inch is 2.54 cm). 2 This results in the exposed image containing a solid image and an amplitude modulation screen with 10% dots.

[1149] The obtained exposed originals were mounted on the cylinders of a Heidelberger Druckmaschinen AG printing press (size 18) without development. A 100L dampening solution circulation tank with a built-in nonwoven filter and temperature control was connected to the press. 80L of 3.5% dampening solution S-Z1 (manufactured by Fujifilm Corporation) was loaded into the circulation tank, and UV CORE TYPE-A J ink (manufactured by T&KTOKA Corporation) was used as the printing ink. After supplying the dampening solution and ink using a standard automatic printing start-up method, 1,000 sheets were printed at a printing speed of 10,000 sheets per hour on SHIRAOI paper (48.5kg ream, manufactured by Nippon Paper Industries Co., Ltd.).

[1150] Next, printing continued. As the number of prints increased, the image area gradually wore down, resulting in a decrease in ink concentration on the printed material. Brush resistance was evaluated by measuring the dot area ratio of 10% halftone dots in the printed material using an eXact spectrophotometer (manufactured by X-Rite) compared to the value measured on the 1,000th print, at which point the print run ended by 3%. The relative brush resistance was evaluated according to the following criteria, with a print run of 50,000 prints set as 100. A higher value indicates better brush resistance.

[1151] Relative brush resistance = (Number of prints of the original offset printing plate) / 50,000) × 100

[1152] -Evaluation Criteria-

[1153] 6: The relative brush resistance value exceeds 110.

[1154] 5: The relative brush resistance value is greater than 100 and less than 110.

[1155] 4: The relative brush resistance value is greater than 90 and less than 100.

[1156] 3: The relative brush resistance value is greater than 80 and less than 90.

[1157] 2: The relative brush resistance value is greater than 70 and less than 80.

[1158] 1: The relative brush resistance value is below 70.

[1159] <Evaluation of Damping Solution Contamination>

[1160] After adjusting the ink-water 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.

[1161] Next, the actions X1 to X3 below were repeated 10 times.

[1162] X1: The original lithographic printing plate (unexposed version) was wetted 50 times by manual pre-wetting.

[1163] X2: After 50 water immersions, 100 sheets were printed on Shiraoi (high-quality paper, manufactured by NIPPON PAPER INDUSTRIES CO.,LTD.).

[1164] X3: Uninstalled version.

[1165] Furthermore, the printing conditions are shown below.

[1166] Printing press: Lithrone LS26 / 104 manufactured by KOMORI Corporation.

[1167] Ink: UV ink (UV CORE TYPE-AJ yellow manufactured by T&K TOKA Corporation) Folio solution: PRESSMAX S-Z1 2% (manufactured by Fujifilm Corporation)

[1168] Pre-wetting: 50 times

[1169] Then, the rubber stopper was removed, the dampening solution was recovered, and the turbidity was evaluated by the refractive index of the dampening solution. The refractive index was measured according to JIS K0102 (2019) and evaluated according to the following standards.

[1170] -Evaluation Criteria-

[1171] 5: Refractive error of 8cm or more

[1172] 4: Refractive error of 6cm or more but less than 8cm

[1173] 3: Refractive error of 4cm or more but less than 6cm

[1174] 2: Refractive error of 2cm or more but less than 4cm

[1175] 1: Refractive error of 0 cm or more and less than 2 cm

[1176] <Sensor Readability>

[1177] The obtained lithographic printing plate original was exposed using a Trendsetter Q800 manufactured by Eastman Kodak Company, which is equipped with an infrared semiconductor laser, at an output power of 14W, an external drum speed of 360rpm, and a resolution of 2,400dpi (dots per inch, 1 inch is 2.54cm). The exposure energy was equivalent to 110mJ / cm². 2 The exposed image contains a data matrix code. The data matrix code (9mm square) was read using an SR-1000W sensor manufactured by KEYENCE CORPORATION, and the following evaluation was performed based on the matching degree (an index representing readability) value.

[1178] -Evaluation Criteria-

[1179] A: The matching degree is above 70%.

[1180] B: Match rate is above 50% but less than 70%.

[1181] C: Match rate is above 30% but less than 50%.

[1182] D: Match score less than 30. Or unable to be read.

[1183] The results are shown in Table 1.

[1184] According to the results recorded in Table 1, the visual clarity of the exposed section of the original developing lithographic printing plate according to the present invention becomes good immediately after exposure, the good visual clarity immediately after exposure is easy to maintain, and the visual clarity of the exposed section also becomes good after storage under white light.

[1185] Comparative Example 1 describes a method in which the image recording layer of the lithographic printing plate does not contain a chromogenic compound but contains an infrared absorber. According to Comparative Example 1, it can be seen that the visual clarity in the exposed section is good immediately after exposure, and the visual clarity of the exposed section is also good after being stored under white light, but it cannot maintain the good visual clarity immediately after exposure and deteriorates.

[1186] Comparative Example 2 involves a method in which the image recording layer of the lithographic printing plate contains a chromogenic compound but not a hydrogen-donating compound. According to Comparative Example 2, the visual clarity in the exposed section is good immediately after exposure and can maintain good visual clarity immediately after exposure; however, after storage under white light, the visual clarity of the exposed section deteriorates.

[1187] Furthermore, it is known that the on-machine developable lithographic printing plate original according to the present invention also has good brush resistance and good color development, and thus can also suppress contamination caused by dampening solution.

[1188] Furthermore, according to the on-machine developable lithographic printing plate original involved in this invention, the sensor readability is also good.

[1189] Industrial availability

[1190] According to the present invention, an on-machine developing type lithographic printing plate master and a method for manufacturing a printing plate using the on-machine developing type lithographic printing plate master can be provided. In the above-mentioned on-machine developing type lithographic printing plate master, the visual recognition in the exposure section is good immediately after exposure, the good visual recognition immediately after exposure is easy to maintain, and the visual recognition of the exposure section is also good after storage under white light.

[1191] The invention has been described in detail and with reference to specific embodiments, but it will be apparent to those skilled in the art that various changes or modifications can be made without departing from the spirit and scope of the invention.

[1192] Furthermore, the contents of Japanese patent applications filed on August 31, 2023 (Japanese Patent Application No. 2023-141847) and February 29, 2024 (Japanese Patent Application No. 2024-030807) are incorporated herein by reference.

[1193] Symbol Explanation

[1194] 1-Original plate for lithographic printing; 1a-Image recording layer; 1b-Support surface; 1c-End face; 2-Collapsed edge; 10-Cutting blade; 10a-Upper cutting blade; 10b-Upper cutting blade; 11-Rotating shaft; 20-Cutting blade; 20a-Lower cutting blade; 20b-Lower cutting blade; 21-Rotating shaft; 30-Original plate for lithographic printing; 31-Aluminum plate; 32, 34-Roller brush; 33-Grinding slurry; 35, 36, 37, 38-Support roller; 50-Main electrolytic cell; 51-AC power supply; 52-Radial drum roller; 53a, 53b-Main electrode, 54-Electrolyte supply port, 55-Electrolyte, 56-Slit, 57-Electrolyte channel, 58-Auxiliary anode, 60-Auxiliary anode tank, 410-Anodizing treatment device, 412-Power supply tank, 414-Electrolysis treatment tank, 416-Aluminum plate, 418, 426-Electrolyte, 420-Power supply electrode, 422, 428-Roller, 424-Clamping roller, 430-Electrolysis electrode, 432-Tank wall, 434-DC power supply, B-Boundary between image recording layer and support, W-Aluminum plate, X-Sinking edge amount, Y-Sinking edge width.

Claims

1. An on-machine developing type lithographic printing plate master, which has an image recording layer on a support. The image recording layer comprises a chromophore compound having groups that cleave upon infrared exposure, a polymerization initiator, a polymerization compound, and a hydrogen-donating compound. The hydrogen-donating compound is a compound different from the polymerization initiator, the polymerizable compound, the chromogenic compound, and the acid-crack compound, and is a compound having at least one intramolecular group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH and having a molecular weight of less than 3000.

2. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The hydrogen-donating compound is a compound having at least one partial structure represented by the following formula (I) within its molecule. In formula (I), X is a hydrogen-donating group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH. R 1A ~R 3A Each is independently a group having at least one member selected from the group consisting of hydrogen atoms, carbon atoms, halogen atoms, and heteroatoms. R 1A ~R 3A At least two of them are optionally linked to form a loop. When X is a monovalent group, R 1A ~R 3A One or more hydrogen atoms contained in the structure are removed to form a linking bond. When X is a divalent group, R 1A ~R 3A One or more hydrogen atoms contained therein may be further removed to form a linking bond.

3. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The hydrogen-donating compound is a compound having at least one partial structure represented by the following formula (II) within the molecule. In formula (II), Ar represents an aromatic ring group. X is a group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH. R 4A It is a group having at least one selected from the group consisting of hydrogen atoms, carbon atoms, halogen atoms, and heteroatoms. m represents an integer from 1 to 5. When m represents an integer greater than 2, multiple X values ​​may be the same or different. n represents an integer from 0 to 5. When n represents an integer greater than 2, multiple R... 4A Whether the R values ​​are the same or different, when n is 2 or more, multiple R values... 4A Optional connections can be used to form a loop. When all X are monovalent groups, R 4A One or more hydrogen atoms contained in the structure are removed to form a linking bond. When at least one X is a divalent group, R 4A One or more hydrogen atoms contained therein may be further removed to form a linking bond.

4. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The hydrogen-donating compound is a compound having at least one partial structure represented by the following formula (III) within the molecule. In formula (III), X is a group selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH. R 5A It is a group having at least one selected from the group consisting of hydrogen atoms, carbon atoms, halogen atoms, and heteroatoms. p represents an integer from 1 to 5. When p represents an integer greater than 2, multiple X's can be the same or different. q represents an integer from 0 to 5. When q represents an integer greater than 2, multiple R5s may be the same or different. When q is greater than 2, multiple R5s may be different. 5A Optional connections can be used to form a loop. p+q is less than 6 When all X are monovalent groups, R 5A One or more hydrogen atoms contained therein are removed to form a linking bond. When at least one X is a divalent group, R 5A One or more hydrogen atoms contained therein may be further removed to form a linking bond.

5. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The hydrogen-donating compound is a compound having at least two groups selected from the group consisting of -OH, -NH-, -SO2-NH-, -SO2-OH, -CO-NH-, and -CO-OH within its molecule.

6. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The hydrogen-donating compound has at least one group selected from the group consisting of -OH and -SO2-NH-.

7. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The hydrogen-donating compound has at least two groups selected from the group consisting of -OH and -SO2-NH-.

8. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The hydrogen-donating compound has at least one phenolic hydroxyl group.

9. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The hydrogen-donating compound has two or more phenolic hydroxyl groups.

10. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The chromophore compound having a group that is cleaved by infrared exposure is anthocyanin represented by Formula 1. In Equation 1, R 1 Indicates that R is obtained through infrared exposure. 1 -L bond cleavage group, R 11 ~R 18 Each of these can independently represent a hydrogen atom, a halogen atom, -Ra, -ORb, -SRc, or -NRdRe, where Ra to Re can independently represent hydrocarbon groups, 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 number 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.

11. The on-machine developing type lithographic printing plate original according to claim 10, wherein, The chromophore compound having a group that is cleaved by infrared exposure is the compound represented by Formula 2. In Equation 2, R 1 Indicates that R is made by infrared exposure. 1 -L bond cleavage group, R 2 and R 3 Each can be independently represented by a hydrogen atom or an alkyl group, R 2 and R 3 Ar can be arbitrarily linked together to form a loop. 1 and Ar 2 Each group independently represents a group that forms a benzene ring or a naphthalene ring, Y 1 and Y 2 Each of the oxygen atom, sulfur atom, and -NR atom can be represented independently. 0 -or dialkylmethylene, R 0 R represents a hydrogen atom, alkyl group, or aryl group. 4 and R 5 Each can independently represent an aliphatic hydrocarbon group, a -CO2M group, or a -PO3M2 group, where M represents a hydrogen atom, a Na atom, a K atom, or an onium group, and R... 6 ~R 9 Each can be used independently to represent a hydrogen atom or an alkyl group, and L can represent 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.

12. The on-machine developing type lithographic printing plate original according to claim 11, wherein, In Formula 2, L represents an oxygen atom.

13. The on-machine developing type lithographic printing plate original according to claim 12, wherein, R in Equation 2 1 The group represented by the following formula (5) In equation (5), R 15 and R 16 Each of these groups independently represents a hydrogen atom, an alkyl group, or an aryl group; E represents an ononyl group; and * represents the bonding site with the oxygen atom represented by L in Formula 2.

14. The on-machine developing type lithographic printing plate original according to claim 1, wherein, Polymerizable compounds include polymerizable compounds with 11 or more functions.

15. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The polymerization initiator comprises a borate compound as an electron-donating polymerization initiator.

16. The on-machine developing type lithographic printing plate original according to claim 1, wherein, The polymerization initiator comprises an onium salt compound as an electron-accepting polymerization initiator.

17. The on-machine developing type lithographic printing plate original according to claim 1, wherein, In addition to the chromogenic compound having groups that are cleaved by infrared exposure, the image recording layer also contains an acid chromogenic agent.

18. The on-machine developable lithographic printing plate original according to any one of claims 1 to 17, wherein, A protective layer is provided on the image recording layer.

19. The on-machine developing type lithographic printing plate original according to claim 18, wherein, The protective layer comprises an inorganic layered compound.

20. The on-machine developing type lithographic printing plate original according to claim 19, wherein, The content of the inorganic layered compound is 5 mg / m³. 2 ~80mg / m 2 .

21. The on-machine developable lithographic printing plate original according to any one of claims 1 to 17, wherein, The micropores in the anodic oxide film of the support are composed of large-diameter pores and small-diameter pores. The large-diameter pores extend from the surface of the anodic oxide film to a depth of 10 nm to 1000 nm. The small-diameter pores are connected to the bottom of the large-diameter pores and extend from the connection point to a depth of 20 nm to 2000 nm. The average diameter of the large-diameter pores at the surface of the anodic oxide film is 15 nm to 100 nm, and the average diameter of the small-diameter pores at the connection point is less than 15 nm.

22. The on-machine developable lithographic printing plate original according to any one of claims 1 to 17, wherein, The micropores in the anodic oxide film of the support are composed of small-diameter pores and large-diameter pores. The small-diameter pores extend from the surface of the anodic oxide film to a depth of 10 nm to 1000 nm. The large-diameter pores are connected to the bottom of the small-diameter pores and extend from the connection point to a depth of 20 nm to 2000 nm. The average diameter of the small-diameter pores at the surface of the anodic oxide film is less than 35 nm, and the average maximum diameter of the large-diameter pores is 40 nm to 300 nm.

23. The on-machine developable lithographic printing plate original according to any one of claims 1 to 17, wherein, The support has an anodized film. The anodic oxide film has the following characteristics sequentially from its surface toward its depth: The upper layer has micropores with an average diameter of 20 nm to 100 nm and a thickness of 30 nm to 500 nm; An intermediate layer having micropores with an average diameter of 1 / 2 to 5 times the average diameter of the micropores in the upper layer and a thickness of 100 nm to 300 nm; and The lower layer has micropores with an average diameter of less than 15 nm and a thickness of 300 nm to 2000 nm.

24. A method for producing a printing plate, comprising: The process of exposing an image to the on-machine developing type lithographic printing plate original as described in any one of claims 1 to 17; The process of removing the unexposed portion of the image recording layer in the original developing lithographic printing plate by supplying at least one of printing ink and dampening solution to the printing press.

Images