Process for producing on-press developable lithographic printing plate precursor and printing plate

Abstract

Provided is a method for producing a lithographic printing plate, which comprises the steps of: (1) providing a lithographic printing plate precursor of the present application; (2) exposing the lithographic printing plate precursor to light; (3) developing the exposed lithographic printing plate precursor.

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 the 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 using 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, there is a growing trend towards simplifying or eliminating the developing process altogether. As one of the simplest developing processes, a method called "in-machine developing" has been proposed. In-machine developing involves exposing the lithographic printing plate to the image, then bypassing the conventional wet developing process, and directly mounting it on the printing press to remove the non-image portions of the image recording layer during the initial stage of the normal printing process.

[0005] Patent Document 1 describes an on-machine developing type lithographic printing plate master, which has a support and an image recording layer on the support. The image recording layer contains an infrared absorber, a polymerization initiator, a polymerization compound, and a chromophore precursor, and has an energy density of 110 mJ / cm² when exposed to an infrared laser with a wavelength of 830 nm. 2 When the image recording layer is exposed, the rate of disappearance of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is 10% to 40%.

[0006] Previous technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2020 / 262691 Summary of the Invention

[0009] The technical problem to be solved by the invention

[0010] When mounting a lithographic printing plate master on a printing press, visual identification of the exposed areas is typically performed. In conventional wet development, since the lithographic printing plate with non-image areas removed is mounted on the printing press, the exposed areas of the lithographic printing plate are easily visually identified. However, in on-machine development, since the lithographic printing plate master with non-image areas still present is mounted on the printing press, the aforementioned images of the lithographic printing plate are often difficult to visually identify.

[0011] Based on the above, and considering the need to improve the color development of the exposure section, a lithographic printing plate master containing a chromophore precursor in the image recording layer was developed.

[0012] However, it has been found that in lithographic printing originals containing chromophore precursors in such image recording layers, a so-called "development delay" that requires time during on-machine development is prone to occur.

[0013] The present invention was made in view of the above, and its object is to provide an on-machine developable lithographic printing plate master with good color development and suppressing development delay, and a method for manufacturing a printing plate using the on-machine developable lithographic printing plate master.

[0014] Furthermore, the present invention provides an in-machine developing type lithographic printing plate master with good color development, suppressing development delay and excellent brush resistance, and a method for manufacturing a printing plate using the in-machine developing type lithographic printing plate master.

[0015] means for solving technical problems

[0016] The following describes the methods used to solve the above problems. [1]

[0018] An on-machine developing type lithographic printing plate master, which sequentially comprises a support, an image recording layer, and a protective layer.

[0019] The aforementioned image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor.

[0020] The aforementioned protective layer contains an ultraviolet absorber. [2]

[0022] An on-machine developing type lithographic printing plate master, which comprises, in sequence, a support body and an image recording layer.

[0023] The aforementioned image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, d) a chromophore precursor, and e) an ultraviolet absorber.

[0024] The aforementioned polymeric compounds are 4 or more functional and have a molecular weight of less than 15,000. [3]

[0026] An on-machine developing type lithographic printing plate master, which sequentially comprises a support, an image recording layer, and a protective layer.

[0027] The aforementioned image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor.

[0028] The aforementioned protective layer contains an ultraviolet absorber.

[0029] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is 10% or more.

[0030] When the above image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%. [4]

[0032] An on-machine developing type lithographic printing plate master, which comprises, in sequence, a support body and an image recording layer.

[0033] The aforementioned image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, d) a chromophore precursor, and e) an ultraviolet absorber.

[0034] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is 10% or more.

[0035] When the above image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%. [5]

[0037] The original plate for machine-developable lithographic printing according to any one of [1] to [4], wherein the ultraviolet absorber has λmax at a wavelength of 280 to 400 nm. [6]

[0039] According to any one of [1] to [5], the on-machine developing type lithographic printing plate original, wherein the image recording layer comprises a polymeric compound with 7 or more functions and a molecular weight of less than 15,000 as the polymeric compound. [7]

[0041] According to any one of [1] to [6], the on-machine developing type lithographic printing plate original, wherein the image recording layer comprises a polymeric compound with 10 or more functions and a molecular weight of less than 15,000 as the polymeric compound. [8]

[0043] The original lithographic printing plate according to any one of [1] to [7], wherein the image recording layer comprises polymer particles. [9]

[0045] According to the machine-developable lithographic printing plate original described in [8], wherein,

[0046] The polymer particles described above have a hydrophobic backbone and contain the following two types of building blocks:

[0047] i) A constituent unit having a cyano side group directly bonded to the hydrophobic backbone; and

[0048] ii) Constituents having side groups containing hydrophilic poly(epoxy) segments.

[10]

[0050] According to the on-machine developing type lithographic printing plate original described in [8], the polymer particles are obtained by reacting a polyisocyanate compound with a compound having active hydrogen, wherein the polyisocyanate compound is an adduct of a polyphenol compound having two or more hydroxyl groups in the molecule and isophorone diisocyanate.

[11]

[0052] According to any one of [1] to

[10] , the original of the machine-developable lithographic printing plate, wherein all hydrogen abstraction enthalpies present in the molecules of the above-mentioned chromophore precursor are greater than -6.5 kcal / mol.

[12]

[0054] The original plate for machine-developable lithography according to any one of [1] to

[11] , wherein the chromophore precursor has a tertiary amine structure.

[13]

[0056] The original plate for machine-developable lithographic printing according to any one of [1] to

[12] , wherein the chromophore precursor comprises an acid chromophore.

[14]

[0058] According to any one of [1] to

[13] , the machine-developable lithographic printing plate original, wherein the support has an anodic oxide film, 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 1,000 nm, the small-diameter pores are connected to the bottom of the large-diameter pores and extend from the connection position 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 position is less than 15 nm.

[15]

[0060] According to any one of [1] to

[13] , the machine-developable lithographic printing plate original, wherein the support has an anodic oxide film, 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 1,000 nm, the large-diameter pores are connected to the bottom of the small-diameter pores and extend from the connection position 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 35 nm or less, and the average diameter of the large-diameter pores is 40 to 300 nm or less.

[16]

[0062] According to any one of [1] to

[13] , the machine-developable lithographic printing plate original, wherein,

[0063] The aforementioned support has an anodic oxide film.

[0064] The above-mentioned anodic oxide film has the following characteristics from the surface to the depth direction:

[0065] The upper layer, with a thickness of 30–500 nm, has micropores with an average diameter of 20–100 nm.

[0066] 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 aforementioned microporous upper layer; and

[0067] The lower layer, with a thickness of 300–2000 nm, has micropores with an average diameter of less than 15 nm.

[17]

[0069] According to any one of claims [1] to

[16] , the original plate for on-machine development is wherein the end of the original plate for on-machine development has a collapsed edge shape with a collapsed edge amount X of 25 to 150 μm and a collapsed edge width Y of 70 to 300 μm.

[18]

[0071] According to claim

[17] , the on-machine developing type lithographic printing plate original has an ink repellent on a portion or all of the side surfaces of the two opposite sides of the lithographic printing plate original.

[19]

[0073] A method for producing a printing plate, comprising:

[0074] The process of exposing an image to the on-machine developing type lithographic printing plate master as described in any one of [1] to

[18] ; and

[0075] The process of removing the unexposed portion of the image recording layer in the original of the machine-developable lithographic printing plate by supplying at least one of printing ink and dampening solution to the printing press.

[0076] Invention Effects

[0077] According to the present invention, it is possible to provide an in-machine developable lithographic printing plate master with good color development and suppressing development delay, and a method for manufacturing a printing plate using the in-machine developable lithographic printing plate master.

[0078] Furthermore, according to the present invention, it is possible to provide an in-machine developable lithographic printing plate master with good color development, suppressing development delay and excellent brush resistance, and a method for manufacturing a printing plate using the in-machine developable lithographic printing plate master. Attached Figure Description

[0079] Figure 1 This is a chart representing an example of an alternating current waveform used in electrochemical roughening treatment.

[0080] Figure 2 This is a side view showing an example of a radial unit in an electrochemical roughening process using alternating current.

[0081] Figure 3 This is a schematic diagram showing the cross-sectional shape of the end of the original lithographic printing plate.

[0082] Figure 4 This is a conceptual diagram representing an example of the cutting section of a longitudinal cutting device.

[0083] Figure 5 This is a side view representing the concept of the brushing and grinding process used in the mechanical roughening treatment during the manufacture of aluminum supports.

[0084] Figure 6 This is a schematic diagram of the anodizing apparatus used in the anodizing process.

[0085] Figure 7 This is a diagram illustrating the method of applying an ink-repellent agent. Detailed Implementation

[0086] 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.

[0087] In the designation of groups (atomic groups) in this specification, the designations without substitution and unsubstituted include not only groups without substituents but also groups with substituents. For example, "alkyl" includes not only alkyl groups without substituents (unsubstituted alkyl) but also alkyl groups with substituents (substituted alkyl).

[0088] 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.

[0089] 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.

[0090] In this invention, a combination of two or more preferred methods is a more preferred method.

[0091] Unless otherwise specified, the mass-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), differential refractometer, and converted from polystyrene as a standard substance.

[0092] The present invention will now be described in detail.

[0093] [Original plate for in-machine developing lithography]

[0094] The first on-machine developing type lithographic printing plate original (hereinafter also referred to as the first lithographic printing plate original) involved in this invention sequentially comprises a support, an image recording layer, and a protective layer.

[0095] The aforementioned image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor.

[0096] The aforementioned protective layer contains an ultraviolet absorber.

[0097] The second on-machine developing type lithographic printing plate original (hereinafter also referred to as the second lithographic printing plate original) involved in this invention sequentially comprises a support body and an image recording layer.

[0098] The aforementioned image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, d) a chromophore precursor, and e) an ultraviolet absorber.

[0099] The aforementioned polymeric compounds are 4 or more functional and have a molecular weight of less than 15,000.

[0100] The third type of on-machine developing lithographic printing plate master (hereinafter also referred to as the third lithographic printing plate master) involved in this invention has, in sequence, a support, an image recording layer, and a protective layer.

[0101] The aforementioned image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor.

[0102] The aforementioned protective layer contains an ultraviolet absorber.

[0103] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is 10% or more.

[0104] When the above image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%.

[0105] The fourth on-machine developing type lithographic printing plate original (hereinafter also referred to as the fourth lithographic printing plate original) involved in this invention has a support body and an image recording layer in sequence.

[0106] The aforementioned image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, d) a chromophore precursor, and e) an ultraviolet absorber.

[0107] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is 10% or more.

[0108] When the above image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%.

[0109] According to the first machine-developable lithographic printing plate original of the present invention, by adopting the above-described structure, it is possible to obtain a machine-developable lithographic printing plate original with good color development and suppressing development delay.

[0110] Furthermore, by employing the above-described structure, the second to fourth in-machine developing type lithographic printing plate originals according to the present invention can obtain in-machine developing type lithographic printing plate originals with good color development, suppressing development delay, and excellent brush resistance.

[0111] The reasons are unclear, but they are speculated to be as follows.

[0112] As described above, in lithographic printing plates containing chromophore precursors in the image recording layer, a "development delay" that requires time during on-machine development is prone to occur. The inventors have noted that lithographic printing plates are typically stored under white fluorescent light.

[0113] The inventors have discovered that under white fluorescent light, chromophore precursors contained in the image recording layer are excited, and these excited chromophore precursors cause undesirable polymerization in the image recording layer. Due to this polymerization, undesirable polymers may exist on the lithographic printing plate before exposure. It is believed that when the lithographic printing plate exposed under white fluorescent light is developed on-machine, although the unexposed areas are removed by ink or dampening solution, the aforementioned polymers that may exist in the unexposed areas are difficult to remove by ink or dampening solution, and removal may take time, thus causing the aforementioned development delay.

[0114] The first on-machine developing type lithographic printing plate of the present invention contains an ultraviolet absorber in its protective layer. Even when the lithographic printing plate is stored under a white fluorescent lamp, the ultraviolet absorber can absorb white light from the white fluorescent lamp, thus suppressing the aforementioned undesirable polymerization reaction.

[0115] It is believed that this will enable the production of machine-developable lithographic printing plates with good color development and the ability to suppress development delay.

[0116] The second machine-developable lithographic printing plate of the present invention contains an ultraviolet absorber in the image recording layer. Similar to the first machine-developable lithographic printing plate described above, it can suppress the aforementioned undesirable polymerization reaction. Furthermore, the image recording layer contains a polymerizable compound that is four or more functional and has a molecular weight of less than 15,000.

[0117] By using polymerizable compounds with four or more functions, the strength of the exposed portion in a lithographic printing plate can be obtained, thus making the lithographic printing plate highly durable.

[0118] Furthermore, by making the molecular weight of the polymerizable compound less than 15,000, it is easier to remove unexposed areas based on ink or dampening solution during in-machine development, thus further improving development delay during in-machine development.

[0119] It is believed that this will enable the production of machine-developable offset printing plates with good color development, suppression of development delay, and excellent brush resistance.

[0120] The third and fourth machine-developable lithographic printing plates of the present invention contain an ultraviolet absorber in the image recording layer or protective layer. Similar to the first machine-developable lithographic printing plate described above, they are able to suppress the aforementioned undesirable polymerization reaction.

[0121] In the developing lithographic printing plates of the 3rd and 4th printing presses, the energy density of the infrared laser exposure at a wavelength of 830nm is 120mJ / cm². 2 When the image recording layer is exposed, the disappearance rate of olefinic unsaturated bonds in the exposed area relative to the unexposed area in the image recording layer is 10% or more. It is believed that when the disappearance rate of olefinic unsaturated bonds is within the above range, the polymerization reaction in the exposed portion of the lithographic printing plate can proceed appropriately, and the strength in the exposed portion can be ensured, thus resulting in excellent brush resistance of the lithographic printing plate.

[0122] In the 3rd and 4th machine-developable lithographic printing plates, when the image recording layer was exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed area relative to the unexposed area was less than 10%. It is believed that since the disappearance rate of olefinic unsaturated bonds is within the above range, undesirable polymerization reactions under white fluorescent light can be suppressed, and thus development delay in machine development can be suppressed.

[0123] It is believed that this will enable the production of machine-developable offset printing plates with good color development, suppression of development delay, and excellent brush resistance.

[0124] The first to fourth machine-developable lithographic printing plates (hereinafter, sometimes collectively referred to as machine-developable lithographic printing plates or simply lithographic printing plates) involved in this invention will be described in detail below.

[0125] In-machine development is a method of removing the non-image parts of the image recording layer after the original lithographic printing plate has been exposed to the image, without the usual wet development process. The plate is directly mounted on the printing press and the image recording layer is removed at the initial stage of the printing process. The original lithographic printing plate that can be in-machine developed is called an in-machine developed lithographic printing plate.

[0126] (Original plate for developing type offset printing on the first machine)

[0127] First, the original first lithographic printing plate of the present invention will be described.

[0128] (Support body)

[0129] As the support, an aluminum support is preferred. The aluminum plate used in this aluminum support comprises 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.

[0130] 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, completely pure aluminum is difficult to manufacture; therefore, alloys containing small amounts of dissimilar elements are acceptable. There are no specific requirements for the composition of the aluminum plates used in aluminum supports; well-known aluminum plates such as JIS A 1050, JIS A 1100, JIS A3103, and JIS A 3005 can be appropriately utilized.

[0131] The thickness of the support (preferably an aluminum plate) is preferably about 0.1 to 0.6 mm.

[0132] (Anodized film)

[0133] The aforementioned support preferably has an anodic oxide film.

[0134] 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).

[0135] From the viewpoints of tone reproduction, brush resistance and brush contamination, the average diameter (average opening diameter) of the micropores on the surface of the anodized 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.

[0136] 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.

[0137] The shape of a micropore is typically a roughly straight tube (roughly cylindrical) with its diameter remaining almost unchanged along the depth direction (thickness direction), but it can also be a cone-shaped micropore with its diameter continuously decreasing along the depth direction (thickness direction). Furthermore, it can also be a shape with its diameter decreasing discontinuously along the depth direction (thickness direction).

[0138] 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.

[0139] Specifically, the micropores preferably consist 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.

[0140] The large-diameter and small-diameter bore sections are described in detail below.

[0141] -Large diameter hole-

[0142] From the viewpoints of tone reproduction, brush resistance and brush contamination, the average diameter (average opening diameter) of the large-diameter orifice on the surface of the anodized 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.

[0143] The average diameter of the large-diameter pores is calculated as follows: the surface of the anodic oxide film is observed with a field emission scanning electron microscope (FE-SEM) at a magnification of 150,000x in N=4 images. In the four images obtained, the diameter of the micropores (large-diameter pores) existing in the range of 400nm×600nm is measured, and the arithmetic mean of the diameters is calculated.

[0144] 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.

[0145] 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). From the viewpoint of achieving better results in the manufacturing method of the lithographic printing plate, a depth A is more preferably 90 nm to 850 nm, further preferably 90 nm to 800 nm, and particularly preferably 90 nm to 600 nm.

[0146] 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.

[0147] There are no particular restrictions on the shape of the large-diameter hole. For example, it can be a generally straight tube (generally cylindrical) or a conical shape in which the diameter decreases in the depth direction (thickness direction). A generally straight tube shape is preferred. Furthermore, there are no particular restrictions on the shape of the bottom of the large-diameter hole. It can be curved (convex) or flat.

[0148] 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.

[0149] -Small Diameter Orifice-

[0150] 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. A small-diameter hole is usually connected to a large-diameter hole, but two or more small-diameter holes can communicate with the bottom of a large-diameter hole.

[0151] The average diameter of the small-diameter aperture at the connecting position is preferably 15 nm or less, more preferably 13 nm or less, more preferably 11 nm or less, and especially preferably 10 nm or less. There is no particular limitation on the lower limit, but 5 nm is preferred.

[0152] The average diameter of the small-diameter orifices is calculated as follows: The surface of the anodic oxide film is observed using a FE-SEM at 150,000x magnification with N=4 images. In the four images obtained, the diameter of the micropores (small-diameter orifices) within a range of 400nm × 600nm is measured, and the arithmetic mean of the diameters is calculated. Alternatively, if the large-diameter orifices are deep, the upper part of the anodic oxide film (the area with the large-diameter orifices) can be cut as needed (e.g., by argon gas cutting), and the surface of the anodic oxide film is then observed using the aforementioned FE-SEM to determine the average diameter of the small-diameter orifices.

[0153] Additionally, when the shape of the small-diameter aperture 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.

[0154] 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 aforementioned depth A). 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.

[0155] 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.

[0156] There are no particular restrictions on the shape of the small-diameter orifice. For example, it can be a generally straight tube (generally cylindrical) or a conical shape in which the diameter decreases in the depth direction. A generally straight tube is preferred. Furthermore, there are no particular restrictions on the shape of the bottom of the small-diameter orifice. It can be curved (convex) or flat.

[0157] There are no particular restrictions on the inner diameter of the small-diameter orifice, but it can be the same size as the diameter at the connecting 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.

[0158] 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.

[0159] 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.

[0160] 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).

[0161] As a type of micropore whose diameter increases discontinuously in the depth direction (thickness direction), an example of a micropore can be formed by a small-diameter pore portion extending from the surface of the anodic oxide film along the depth direction and a large-diameter pore portion communicating with the bottom of the small-diameter pore portion and extending from the communication position along the depth direction.

[0162] 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.

[0163] -Small Diameter Orifice-

[0164] There is no particular limitation on the average diameter (average opening diameter) of the small-diameter orifice at the surface of the anodic oxide film, 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.

[0165] The average diameter of the small-diameter pores is calculated as follows: The surface of the anodic oxide film is observed with N=4 images using a field emission scanning electron microscope (FE-SEM) at a magnification of 150,000x. In the four images obtained, the diameter of the micropores (large-diameter pores) existing in the range of 400nm×600nm is measured, and the arithmetic mean of the diameters is calculated.

[0166] Additionally, when the shape of the small-diameter aperture 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.

[0167] 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).

[0168] 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.

[0169] There are no particular restrictions on the shape of the small-diameter orifice. 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). A generally straight tube shape is preferred. Furthermore, there are no particular restrictions on the shape of the bottom of the small-diameter orifice. It can be curved (convex) or flat.

[0170] There are no particular restrictions on the inner diameter of the small-diameter orifice, but it is preferable to be the same size as or smaller than the diameter of the opening. In addition, the inner diameter of the small-diameter orifice can differ from the diameter of the opening by about 1 nm to 10 nm.

[0171] -Large diameter hole-

[0172] A large-diameter hole is a hole portion that connects to the bottom of a small-diameter hole portion and extends further along the depth direction (thickness direction) from the connection point. A large-diameter hole typically consists of two or more small-diameter hole portions connected to the bottom of a large-diameter hole portion.

[0173] 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.

[0174] The average diameter of the large-diameter pores is calculated as follows: The surface of the anodic oxide film is observed using a FE-SEM at 150,000x magnification with N=4 images. In the four images obtained, the diameter of the micropores (large-diameter pores) within a range of 400nm × 600nm is measured, and the arithmetic mean of the diameters is calculated. Alternatively, if the depth of the small-diameter pores is deep, the upper part of the anodic oxide film (the area with the small-diameter pores) can be cut as needed (e.g., by argon gas cutting), and the surface of the anodic oxide film is then observed using the aforementioned FE-SEM to determine the average diameter of the large-diameter pores.

[0175] 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.

[0176] 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 aforementioned depth A'). 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.

[0177] 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.

[0178] There are no particular restrictions on the shape of the large-diameter hole. For example, it can be a generally straight tube (generally cylindrical) or a conical shape in which the diameter decreases in the depth direction. A generally straight tube is preferred. Furthermore, there are no particular restrictions on the shape of the bottom of the large-diameter hole. It can be curved (convex) or flat.

[0179] There are no particular restrictions on the inner diameter of the large-diameter hole, but it can be the same size as the diameter at the connection point, or it can be smaller or larger than the aforementioned diameter. Furthermore, the inner diameter of the large-diameter hole can typically differ from the diameter of the opening by about 1 nm to 10 nm.

[0180] The aforementioned support has an anodic oxide film.

[0181] The above-mentioned anodic oxide film has the following characteristics from the surface to the depth direction:

[0182] The upper layer, with a thickness of 30–500 nm, has micropores with an average diameter of 20–100 nm.

[0183] The intermediate layer has a thickness of 100 to 300 nm and has micropores with an average diameter of 1 / 2 to 5 times the average diameter of the micropores in the microporous upper layer; and the lower layer has a thickness of 300 to 2000 nm and has micropores with an average diameter of 15 nm or less.

[0184] In machine-developable lithographic printing plates, from the viewpoint of improving the visual recognizability of the image, 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.

[0185] In the lithographic printing process, a plate inspection is typically performed to confirm whether an image has been recorded according to the intended purpose before mounting the printing plate on the printing press. In on-machine developing lithographic printing plates, the image needs to be checked during the image exposure stage; therefore, a mechanism that generates the so-called printed image is used in the image exposure unit.

[0186] As a method for quantitatively evaluating the ease of viewing (visual recognition) 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 (SpectroEye, manufactured by X-Rite Inc.). The greater the difference between the brightness of the exposed and unexposed portions of the image obtained through measurement, the easier it is to see the image portion.

[0187] It has been determined that, in order to increase the difference in brightness between the exposed and unexposed areas of an image, a high value of the lightness L* in the CIEL*a*b* color system on the surface of the anodized film is effective. That is, the value of lightness L* is preferably 60 to 100.

[0188] 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.

[0189] (Manufacturing of aluminum supports with anodized coating)

[0190] As an example of a support, a method for manufacturing an aluminum support having an anodized film is described.

[0191] Aluminum supports with anodized film can be manufactured using known methods. There are no particular limitations on the manufacturing method of aluminum supports with anodized film. A preferred method for manufacturing aluminum supports with anodized film includes the following steps: a step of roughening an aluminum plate (roughening treatment step); a step of anodizing the roughened aluminum plate (anodizing treatment step); and a step of contacting the aluminum plate having the anodized film obtained in the anodizing treatment step with an acidic or alkaline aqueous solution to enlarge the diameter of the micropores in the anodized film (pore enlargement treatment step).

[0192] The following is a detailed description of each process.

[0193] <Roughening Process>

[0194] 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.

[0195] 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 and mechanical roughening treatment.

[0196] 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.

[0197] Electrochemical roughening treatment is preferably carried out in aqueous solutions of nitric acid and hydrochloric acid.

[0198] Mechanical roughening is typically performed to set the surface roughness of the aluminum plate to Ra: 0.35–1.0 μm.

[0199] There are no particular restrictions on the conditions for mechanical roughening treatment, but it can be carried out, for example, according to the method 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.

[0200] Furthermore, there are no particular limitations to chemical roughening treatment; it can be carried out using known methods.

[0201] Preferably, the following chemical etching process is performed after mechanical roughening.

[0202] The chemical etching process performed after mechanical roughening is for the following purposes: to smooth the uneven edges of the aluminum plate surface, to prevent ink catching on during printing, thereby improving the stain resistance of the lithographic printing plate, and to remove unwanted substances such as abrasive particles remaining on the surface.

[0203] 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.

[0204] There are no particular restrictions on the alkaline agents used in the alkaline solution, but preferred examples include sodium hydroxide, potassium hydroxide, sodium metasilicate, sodium carbonate, sodium aluminate, and sodium gluconate.

[0205] 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 more preferably 30% by mass or less, and more preferably 25% by mass or less.

[0206] Furthermore, the temperature of the alkaline solution is preferably above room temperature, more preferably above 30°C or below 80°C, and more preferably below 75°C.

[0207] The preferred etching amount is 0.01 g / m. 2 More preferably 0.05 g / m 2 30g / m³ or higher is preferred 2 Below, 20g / m is preferred. 2 the following.

[0208] The processing time corresponding to the etching amount is preferably 2 to 5 minutes, and from the point of view of improving productivity, 2 to 10 seconds is more preferred.

[0209] 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.

[0210] There are no particular limitations on the acid used in the acidic solution, but examples include sulfuric acid, nitric acid, and hydrochloric acid. The concentration of the acidic solution is preferably 1–50% by mass. The temperature of the acidic solution is preferably 20–80°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.

[0211] The following examples illustrate preferred methods for roughening processes.

[0212] -Method SA-

[0213] The processes shown in (1) to (8) are performed sequentially.

[0214] (1) Chemical etching treatment using alkaline aqueous solution (first alkaline etching treatment)

[0215] (2) Chemical etching treatment using acidic aqueous solution (first decontamination treatment)

[0216] (3) Electrochemical roughening treatment using an aqueous solution based on nitric acid (first electrochemical roughening treatment) was used.

[0217] (4) Chemical etching treatment using alkaline aqueous solution (second alkaline etching treatment)

[0218] (5) Chemical etching treatment using acidic aqueous solution (second decontamination treatment)

[0219] (6) Electrochemical roughening treatment using an aqueous solution mainly composed of hydrochloric acid (second electrochemical roughening treatment) was used.

[0220] (7) Chemical etching treatment using alkaline aqueous solution (third alkaline etching treatment)

[0221] (8) Chemical etching treatment using acidic aqueous solution (third cleaning treatment)

[0222] -Method SB-

[0223] The processes shown in (11) to (15) are performed sequentially.

[0224] (11) Chemical etching treatment using alkaline aqueous solution (4th alkaline etching treatment)

[0225] (12) Chemical etching treatment using acidic aqueous solution (4th cleaning treatment)

[0226] (13) Electrochemical roughening treatment using an aqueous solution mainly composed of hydrochloric acid (3rd electrochemical roughening treatment) was used.

[0227] (14) Chemical etching treatment using alkaline aqueous solution (5th alkaline etching treatment)

[0228] (15) Chemical etching treatment using acidic aqueous solution (5th cleaning treatment)

[0229] 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.

[0230] 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 .

[0231] The aqueous solution mainly composed of nitric acid used in the first electrochemical roughening treatment of Method SA can be exemplified by aqueous solutions used in electrochemical roughening treatments employing direct current or alternating current. For example, aqueous solutions 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.

[0232] 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.

[0233] The AC power waveform for electrochemical roughening treatment can use sine waves, rectangular waves, trapezoidal waves, or triangular waves, etc. The preferred frequency is 0.1Hz to 250Hz.

[0234] Figure 1 This is a chart representing an example of an alternating current waveform used in electrochemical roughening treatment.

[0235] Figure 1 In 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 of the aluminum plate (tc / ta) is 1 to 20; the ratio of the charge Qc during the cathode reaction to the charge Qa during the anode reaction of the aluminum plate (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 values ​​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 .

[0236] In electrochemical roughening treatment using alternating current, it is possible to use Figure 2 The apparatus shown.

[0237] Figure 2 This is a side view showing an example of a radial unit in an electrochemical roughening process using alternating current.

[0238] 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.

[0239] An aluminum plate W is rolled onto a radial drum roller 52, which is immersed in the main electrolytic cell 50, and electrolyzed during transport via main electrodes 53a and 53b connected to an AC power supply 51. Electrolyte 55 is supplied from the electrolyte supply port 54 through a slit 56 to the electrolyte channel 57 between the radial drum roller 52 and the main electrodes 53a and 53b. The aluminum plate W, after being treated in the main electrolytic cell 50, is then electrolyzed in an auxiliary anode tank 60. In this auxiliary anode tank 60, an auxiliary anode 58 is positioned opposite the aluminum plate W, and electrolyte 55 is supplied in a manner that flows through the space between the auxiliary anode 58 and the aluminum plate W.

[0240] From the viewpoint of facilitating the manufacture of the original offset printing plate as specified, 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 .

[0241] From the viewpoint of facilitating the manufacture of the specified lithographic printing plate original, the amount of aluminum plate dissolved in the third and fifth alkaline etching processes is preferably 0.01 g / m³. 2 ~0.8g / m 2 More preferably 0.05g / m 2 ~0.3g / m 2 .

[0242] 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.

[0243] The concentration of acid in the acidic aqueous solution is preferably 0.5% to 60% by mass.

[0244] <Anodizing Process>

[0245] 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.

[0246] 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.

[0247] 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, aminosulfonic 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. There are no particular limitations on the aluminum ion content, but 1–10 g / L is preferred.

[0248] 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 5~50A / 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.

[0249] 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.

[0250] 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 first anodizing process is sometimes referred to as the first anodizing process, and the second 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.

[0251] Furthermore, the following hole-expansion treatment can be performed after the anodizing treatment, followed by another anodizing treatment. In this case, the first anodizing treatment, the hole-expansion treatment, and the second anodizing treatment are performed.

[0252] 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.

[0253] <Bore Enlargement Process>

[0254] 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.

[0255] 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.

[0256] When using an alkaline aqueous solution in the hole-expanding process, it is preferable to use at least one alkaline aqueous solution selected from 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.

[0257] 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).

[0258] Aluminum ions can be included in alkaline or acidic aqueous solutions. There are no particular restrictions on the content of aluminum ions, but 1–10 g / L is preferred.

[0259] 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 method described in paragraphs 0109 to 0114 of Japanese Patent Application Publication No. 2005-254638 can be used.

[0260] 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.

[0261] 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.

[0262] [Image recording layer]

[0263] The image recording layer described above contains a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor.

[0264] a) Polymer compounds

[0265] 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, it is preferable to have at least one terminal olefin unsaturated bond, and more preferably to have two or more terminal olefin unsaturated bonds. 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.

[0266] From the viewpoint of brush resistance, the polymerizable compound is preferably 4-functional or more, more preferably 7-functional or more, and even more preferably 10-functional or more. "Functionality" refers to the functional group that contributes to polymerization, and is preferably an olefinic unsaturated bond. For example, "4-functional or more" means that the number of functional groups that contribute to polymerization is 4 or more.

[0267] There are no particular restrictions on the polymerizability of the compounds, but they are usually 20 or less functional.

[0268] From the viewpoint of brush resistance, the polymerizable compound is preferably an olefin unsaturated compound with 4 or more functions, more preferably an olefin unsaturated compound with 7 or more functions, and even more preferably an olefin unsaturated compound with 10 or more functions.

[0269] There are no particular limitations on the molecular weight (weight-average molecular weight in the case of a molecular weight distribution), but from the viewpoint of machine developability, a smaller molecular weight is preferred, and from the viewpoint of brush resistance, a larger molecular weight is preferred.

[0270] The molecular weight is preferably less than 15,000. Furthermore, the molecular weight is preferably 100 or higher.

[0271] From the perspective of balancing 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.

[0272] 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.

[0273] As a preferred embodiment, the image recording layer preferably contains a polymeric compound with 10 or more functions and a molecular weight of less than 15,000 as the polymeric compound.

[0274] 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, it is also possible to use compounds that replace the aforementioned unsaturated carboxylic acids with unsaturated phosphonic acids, styrene, vinyl ethers, etc. These compounds are described in Japanese Patent Application Publication No. 2006-508380, Japanese Patent Application Publication No. 2002-287344, Japanese Patent Application Publication No. 2008-256850, Japanese Patent Application Publication No. 2001-342222, Japanese Patent Application Publication No. 9-179296, Japanese Patent Application Publication No. 9-179297, Japanese Patent Application Publication No. 9-179298, Japanese Patent Application Publication No. 2004-294935, Japanese Patent Application Publication No. 2006-243493, Japanese Patent Application Publication No. 2002-275129, Japanese Patent Application Publication No. 2003-64130, Japanese Patent Application Publication No. 2003-280187, Japanese Patent Application Publication No. 10-333321, etc.

[0275] Specific examples of ester monomers of polyol compounds and unsaturated carboxylic acids 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 amide monomers of polyamine compounds and unsaturated carboxylic acids include methylenebisacrylamide, methylenebisacrylamide, 1,6-hexamethylenebisacrylamide, 1,6-hexamethylenebisacrylamide, diethylenetriaminetriacrylamide, xylenebisacrylamide, and diphenylbisacrylamide.

[0276] 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, 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, can be cited.

[0277] CH2=C(R M4 )COOCH2CH(R M5 )OH (M)

[0278] In formula (M), R M4 and R M5 Each can be used to represent a hydrogen atom or a methyl group independently.

[0279] 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.

[0280] The details of the polymeric compound's structure, whether it is used alone or in combination, the dosage, and other usage methods can be arbitrarily set taking into account the final use of the original offset printing plate.

[0281] The content of the polymeric compound in the total solids content of the image recording layer is preferably 1 to 50% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass.

[0282] b) Infrared absorber

[0283] Infrared absorbers have the function of moving electrons and / or energy towards polymerization initiators when excited by infrared radiation. Furthermore, they have the function of converting the absorbed infrared radiation into heat. Infrared absorbers preferably have maximum absorption in the wavelength region of 750–1400 nm. Examples of infrared absorbers include dyes or pigments, with dyes being preferred.

[0284] As dyes, commercially available dyes and well-known dyes listed in publications such as "Dye Handbook" (The Society of Synthetic Organic Chemistry, Japan, ed., published in 1955) can be used. Specifically, examples include azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methylene dyes, anthocyanin dyes, squaric acid pigments, pyranium salts, and metal thiol complexes.

[0285] Among the dyes, anthocyanin, squaric acid pigment, and pyranonium salt are preferred, anthocyanin is more preferred, and indocyanine pigment is especially preferred.

[0286] Anthocyanins can be exemplified by anthocyanins represented by the following formula (a).

[0287] [Chemical Formula 1]

[0288] Equation (a)

[0289]

[0290] In equation (a), X 1 Represents hydrogen atom, halogen atom, -N(R) 9 (R) 10 -X 2 -L 1 Or the groups shown below. Here, R 9 and R 10 They can be the same, they can be different, and they can also independently represent aromatic hydrocarbons with 6 to 10 carbon atoms, alkyl or hydrogen atoms with 1 to 8 carbon atoms, or R. 9 With R 10 They bond together to form a ring. Aromatic hydrocarbons with 6 to 10 carbon atoms or alkyl groups with 1 to 8 carbon atoms may have substituents. R 9 and R 10 Phenyl is preferred. X 2 L represents an oxygen atom or a sulfur atom. 1 This refers to a hydrocarbon group with 1 to 12 carbon atoms, or a hydrocarbon group with 1 to 12 carbon atoms containing a heteroatom. Here, the heteroatom represents N, S, O, a halogen atom, or Se. Among the groups shown below, Xa... - With Za (described later) - With the same meaning, Ra represents a hydrogen atom or a substituent selected from alkyl, aryl, substituted or unsubstituted amino, and halogen atoms.

[0291] [Chemical Formula 2]

[0292]

[0293] In equation (a), R 1 and R 2 Each group independently represents a hydrocarbon group with 1 to 12 carbon atoms. Considering the preservation stability of the image recording layer coating solution, R... 1 and R 2 Hydrocarbon groups with 2 or more carbon atoms are preferred, especially R. 1 and R 2 They bond together to form 5-membered or 6-membered rings.

[0294] In equation (a), Ar 1 and Ar 2These can be the same or different, and each can represent an aromatic hydrocarbon. Aromatic hydrocarbons can have substituents. Preferred aromatic hydrocarbons include benzene ring groups and naphthyl ring groups. Furthermore, preferred substituents include hydrocarbon groups with 12 or fewer carbon atoms, halogen atoms, and alkoxy groups with 12 or fewer carbon atoms. 1 and Y 2 They can be the same or different, representing either a sulfur atom or a dialkylmethylene with 12 or fewer carbon atoms, respectively. R 3 and R 4 These can be the same or different, representing hydrocarbon groups with 20 or fewer carbon atoms. Hydrocarbon groups with 20 or fewer carbon atoms can have substituents. Preferred substituents include alkoxy, carboxyl, and sulfonyl groups with 12 or fewer carbon atoms. R 5 R 6 R 7 and R 8 These can be the same or different, representing either hydrogen atoms or hydrocarbon groups with 12 or fewer carbon atoms. Considering the ease of obtaining raw materials, hydrogen atoms are preferred. Furthermore, Za... - This indicates an anionic counteractor. Specifically, the anthocyanin represented by formula (a) has an anionic substituent within its structure, thus eliminating the need for Za without the need for neutralizing the charge. - Regarding Za - From the perspective of the preservation stability of the image recording layer coating solution, the preferred ions are halide ions, perchlorate ions, tetrafluoroborate ions, hexafluorophosphate ions, or sulfonate ions, and more preferably perchlorate ions, hexafluorophosphate ions, or arylsulfonate ions.

[0295] Among the anthocyanins represented by formula (a), X is more preferred. 1 It is diphenylamino. Furthermore, X is preferred. 1 It is diphenylamino, and Y 1 and Y 2 All are dimethylmethylene.

[0296] Specific examples of anthocyanins include compounds described in paragraphs 0017 to 0019 of Japanese Patent Application Publication No. 2001-133969, paragraphs 0016 to 0021 of Japanese Patent Application Publication No. 2002-023360, and paragraphs 0012 to 0037 of Japanese Patent Application Publication No. 2002-040638. Preferably, compounds described in paragraphs 0034 to 0041 of Japanese Patent Application Publication No. 2002-278057 and paragraphs 0080 to 0086 of Japanese Patent Application Publication No. 2008-195018 are examples. Particularly preferred are compounds described in paragraphs 0035 to 0043 of Japanese Patent Application Publication No. 2007-90850.

[0297] 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.

[0298] As a pigment, compounds described in paragraphs 0072 to 0076 of Japanese Patent Application Publication No. 2008-195018 are preferred.

[0299] Infrared absorbers can be used alone or in combination with two or more.

[0300] The content of the infrared absorber in the total solids composition of the image recording layer is preferably 0.05 to 30% by mass, more preferably 0.1 to 20% by mass, and even more preferably 0.2 to 10% by mass.

[0301] c) Polymerization initiator

[0302] Polymerization initiators are compounds that generate polymerization initiators such as 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.

[0303] 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.

[0304] The free radical polymerization initiator can be either an electron-accepting polymerization initiator or an electron-donating polymerization initiator.

[0305] Electron-receptive polymerization initiators

[0306] 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.

[0307] As organohalides, compounds described in paragraphs 0022 to 0023 of Japanese Patent Application Publication No. 2008-195018 are preferred.

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

[0309] Examples of azo compounds include those described in Japanese Patent Application Publication No. 8-108621.

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

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

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

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

[0314] Examples of disulfone compounds include those described in Japanese Patent Application Publication No. 61-166544 and Japanese Patent Application Publication No. 2002-328465.

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

[0316] Among electron-accepting polymerization initiators, more preferred examples include onium salts such as iodinated salts, sulfonium salts, and azazine onium salts. 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.

[0317] As examples of iodized salts, diphenyl iodides are preferred, especially those having electron-donating groups as substituents, such as those obtained by substitution with alkyl or alkoxy groups, and asymmetric diphenyl iodides are 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-octoxyphenyl-2,4,6-trimethoxyphenyliodonium = 1-perfluorobutylsulfonate, 4-octoxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, and bis(4-tert-butylphenyl)iodonium = tetraphenylborate.

[0318] Examples of sulfonium salts include triaryl sulfonium salts, particularly those having electron-withdrawing groups as substituents, such as those obtained by substituting at least a portion of the groups on the aromatic ring with halogen atoms. More preferably, triaryl sulfonium salts have a total number of halogen atoms substituting four or more on the aromatic ring. Specific examples include triphenylsulfonium-hexafluorophosphate, triphenylsulfonium-benzoylformate, bis(4-chlorophenyl)phenylsulfonium-benzoylformate, bis(4-chlorophenyl)-4-methylphenylsulfonium-tetrafluoroborate, tri(4-chlorophenyl)sulfonium-3,5-bis(methoxycarbonyl)benzenesulfonate, tri(4-chlorophenyl)sulfonium-hexafluorophosphate, and tri(2,4-dichlorophenyl)sulfonium-hexafluorophosphate.

[0319] Electron-receiving polymerization initiators can be used alone or in combination with two or more.

[0320] The content of the electron-accepting polymerization initiator in the total solids composition of the image recording layer is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, and even more preferably 0.8 to 20% by mass.

[0321] <Electron-donating polymerization initiators>

[0322] Electron-donating polymerization initiators help improve the brush resistance of lithographic printing plates made from lithographic printing plate originals. Five examples of electron-donating polymerization initiators can be cited.

[0323] (i) Alkyl or arylate complexes: These are thought to involve the oxidative cleavage of carbon-heterobonds, generating active free radicals. Specifically, examples include borates.

[0324] (ii) Glycine compounds: It is assumed that an active free radical is generated by the cleavage of the CX bond on the carbon adjacent to nitrogen due to oxidation. Preferably, X is 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.

[0325] (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 process. Specifically, examples include phenylthioacetic acid (which may have substituents in the phenyl group), etc.

[0326] (iv) Tin-containing compounds: Compounds formed by replacing the nitrogen atoms of the above-mentioned aminoacetic acid compounds with tin atoms can generate active free radicals through the same action.

[0327] (v) Sulfites: These can generate reactive free radicals through oxidation. Examples include sodium arylsulfite.

[0328] 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.

[0329] As a counter cation of borate compounds, alkali metal ions or tetraalkylammonium ions are preferred, and sodium ions, potassium ions or tetrabutylammonium ions are more preferred.

[0330] Specific examples of borate compounds include the following compounds. Wherein, Xc+ 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.

[0331] [Chemical Formula 3]

[0332]

[0333] [Chemical Formula 4]

[0334]

[0335] [Chemical Formula 5]

[0336]

[0337] [Chemical Formula 6]

[0338]

[0339] Electron-donating polymerization initiators can be used alone or in combination with two or more.

[0340] The content of the electron-donating polymerization initiator in the total solids composition of the image recording layer is preferably 0.01 to 30% by mass, more preferably 0.05 to 25% by mass, and even more preferably 0.1 to 20% by mass.

[0341] d) Chromoplast precursor

[0342] The aforementioned image recording layer contains chromophore precursors.

[0343] From the viewpoint of color development, the aforementioned chromophore precursor preferably contains an acidic color-developing agent. Furthermore, from the viewpoint of color development, the chromophore precursor preferably contains a colorless compound.

[0344] As a preferred approach, the chromophore precursor is preferably an acid-producing agent.

[0345] The "chromophore precursor" used in this invention refers to a compound that has the property of developing or decolorizing upon stimulation by light, acid, or the like, and that changes the color of the image recording layer. Furthermore, the "acid chromophore" refers to a compound that develops or decolorizes upon heating in a state where it has received protons from an electron-accepting compound (e.g., an acid). As an acid chromophore, colorless compounds having partial skeletons such as lactones, lactams, sulfolactones, spiropyrans, esters, or amides are particularly preferred, and these partial skeletons rapidly undergo ring-opening or cleavage upon contact with an electron-accepting compound.

[0346] From the viewpoint of brush resistance, the hydrogen abstraction enthalpy of all hydrogen atoms present in the molecule of the above-mentioned chromophore precursor is preferably -12.0 kcal / mol or more, more preferably -8.0 kcal / mol or more, more preferably -6.5 kcal / mol or more, even more preferably -4.0 kcal / mol or more, and particularly preferably 0.0 kcal / mol or more.

[0347] The higher the value of the hydrogen abstraction enthalpy, the more suppressed the abstraction of hydrogen atoms from the chromophore precursor by free radicals and other polymerization initiators is, resulting in a longer polymerization reaction and thus excellent curing properties and brush resistance.

[0348] Furthermore, as a preferred embodiment, the hydrogen abstraction enthalpy of all hydrogen atoms present in the molecule of the chromophore precursor is preferably -2.0 kcal / mol or less.

[0349] The hydrogen abstraction enthalpy of all hydrogen atoms present in the molecule of the chromophore precursor described above in this invention is calculated by the following method.

[0350] The calculation program used Gaussian 16, the calculation level was set to density functional theory (B3LYP / 6-31+G**), and the solvent effect was set to SCRF method (solvent: methanol). For the reaction with the growth free radical caused by hydrogen abstraction, the enthalpy of the reactants and products were calculated separately, and the difference between the two was used to calculate the reaction enthalpy.

[0351] More specifically, it is implemented as follows. For the growth radical, colorless dye-H (LeucoDye-H), hydrogenation growth radical, and colorless dye radical (LeucoDye-radical) in the following chemical reaction formulas, Gaussian is used with PrePost software GaussView6 for modeling. The calculation conditions are specified as #p opt b3lyp / 6-31+g(d,p)scrf=(solvent=methanol), set to charge 0 and multiplicity 2 in the case of radicals, and set to charge 0 and multiplicity 1 in cases other than radicals. The #p specification is for detailed log output and can be omitted.

[0352] Based on the energy (unit: hartree) of the optimized structure, calculate the enthalpy of formation of the reactants (the sum of the energies of the growth radical and the colorless dye -H) and the enthalpy of formation of the products (the sum of the energies of the hydrogenation growth radical and the colorless dye radical). Subtract the enthalpy of formation of the reactants from the enthalpy of formation of the products to obtain the hydrogen abstraction enthalpy. The unit conversion is 1 hartree = 627.51 kcal / mol.

[0353] [Chemical Formula 7]

[0354]

[0355] For example, the hydrogen abstraction enthalpy of each hydrogen atom in the following compounds is as follows.

[0356] [Chemical Formula 8]

[0357]

[0358] From the perspective of brush resistance, the above-mentioned chromophore precursors preferably do not have a structure in which hydrogen atoms are directly bonded to nitrogen atoms.

[0359] The structure in which hydrogen atoms are directly bonded to nitrogen atoms (NH structure) is prone to hydrogen abstraction reactions caused by free radicals, etc. If the compound does not have this structure, it can inhibit the abstraction of hydrogen atoms from the above-mentioned chromophore precursors and produce polymerization reactions over a long period of time. Therefore, it has excellent curability and even better brush resistance.

[0360] The aforementioned chromophore precursor preferably has a tertiary amine structure. A tertiary amine structure is an amine structure containing a nitrogen atom, wherein none of the atoms directly bonded to the nitrogen atom are hydrogen atoms. The NH structure is absent in the tertiary amine structure.

[0361] From the viewpoint of color development, the color-developing agent used in this invention is preferably selected from at least one compound selected from spiropyran compounds, spiroxazine compounds, spironolactone compounds, and spironolactam compounds.

[0362] From a visibility point of view, the preferred hue of the pigment after color development is green, blue, or black.

[0363] Furthermore, from the viewpoints of color development, visual recognizability of the exposed area, and brush resistance, the aforementioned acid colorant is preferably a colorless pigment.

[0364] As for the aforementioned colorless pigment, there are no particular restrictions as long as it has a colorless structure, but it is preferred to have a spiro structure, and more preferably to have a spironolactone ring structure.

[0365] Furthermore, from the viewpoints of color development, visual recognizability of the exposed portion, and brush resistance, the colorless pigment described above is preferably a colorless pigment having a phthaloyl structure or a fluorane parent structure.

[0366] Furthermore, from the viewpoints of color development, visual recognizability of the exposed portion, and brush resistance, the aforementioned colorless pigment having a phthaloyl structure or a fluorane parent structure is preferably a compound represented by any one of the following formulas (Le-1) to (Le-3), and more preferably a compound represented by the following formula (Le-2).

[0367] [Chemical Formula 9]

[0368]

[0369] In formulas (Le-1) to (Le-3), ERG independently represents an electron-donating group, X1 to X4 independently represent a hydrogen atom, a halogen atom, or a dialkylphenylamino group, and X5 to X 10 Each of the following groups independently represents a hydrogen atom, a halogen atom, or a monovalent organic group. Y1 and Y2 independently represent C or N. When Y1 is N, X1 does not exist. When Y2 is N, X4 does not exist. Ra1 represents a hydrogen atom, an alkyl group, or an alkoxy group. Rb1 to Rb4 independently represent an alkyl group or an aryl group.

[0370] From the viewpoints of color development, visual recognizability of the exposed portion, and UV brush resistance, the electron-donating group in the ERG of formulas (Le-1) to (Le-3) is preferably amino, alkylamino, arylamino, dialkylamino, monoalkylmonoarylamino, diarylamino, alkoxy, aryloxy, or alkyl. More preferably, it is amino, alkylamino, arylamino, dialkylamino, monoalkylmonoarylamino, diarylamino, alkoxy, or aryloxy. It is even more preferably arylamino or diarylamino, and especially preferably arylamino.

[0371] From the viewpoints of color development, visual recognizability of the exposed part, and UV brush resistance, X1 to X4 in formulas (Le-1) to (Le-3) are preferably hydrogen atoms or chlorine atoms, and more preferably hydrogen atoms.

[0372] From the perspectives of color development, visual recognizability of the exposed area, and UV brush resistance, X5 to X in formula (Le-2) or formula (Le-3) 10 Each atom is preferably a hydrogen atom, halogen atom, alkyl, aryl, amino, alkylamino, arylamino, dialkylamino, monoalkylmonarylamino, diarylamino, hydroxyl, alkoxy, aryloxy, acyl, alkoxycarbonyl, aryloxycarbonyl or cyano, more preferably a hydrogen atom, halogen atom, alkyl, aryl, alkoxy or aryloxy, even more preferably a hydrogen atom, halogen atom, alkyl or aryl, and especially preferably a hydrogen atom.

[0373] From the viewpoints of color development, visual recognizability of the exposed part, and UV brush resistance, Y1 and Y2 in formulas (Le-1) to (Le-3) are preferably at least one of them as C, and more preferably both Y1 and Y2 are C.

[0374] From the viewpoints of color development, visual recognizability of the exposed part, and UV brush resistance, Ra1 in formulas (Le-1) to (Le-3) is preferably alkyl or alkoxy, more preferably alkoxy, and especially preferably methoxy.

[0375] 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.

[0376] These chromophore precursors can be used alone or in combination with two or more components.

[0377] The content of chromophore precursor is preferably 0.5% to 10% by mass, more preferably 1% to 5% by mass, relative to the total mass of the image recording layer.

[0378] Image recording layers can contain polymeric compounds, chain transfer agents, low-molecular-weight hydrophilic compounds, sensitizers, and other components. Details will be discussed later.

[0379] The first lithographic printing plate original involved in this invention has a protective layer.

[0380] [Protective Layer]

[0381] 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.

[0382] Protective layers with such properties are described, for example, in U.S. Patent No. 3,458,311 and Japanese Patent Publication No. 55-49729. As the low-oxygen permeability polymer used in the protective layer, either a water-soluble polymer or a water-insoluble polymer can be appropriately selected, and two or more types can be mixed as needed. Specifically, examples include polyvinyl alcohol resin (including polyvinyl alcohol and modified polyvinyl alcohol), polyvinylpyrrolidone, water-soluble cellulose derivatives, and poly(meth)acrylonitrile.

[0383] 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.

[0384] The degree of saponification can be measured according to the method described in JIS K 6726:1994.

[0385] 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.

[0386] Among water-soluble polymers, polyvinyl alcohol resin is preferred.

[0387] (UV absorber)

[0388] The protective layer contains ultraviolet absorbers.

[0389] The ultraviolet absorber has a maximum absorption wavelength (λmax) in the wavelength region of 280 to 400 nm, and is preferably any one of organic compounds, inorganic compounds, or organic-inorganic mixed compounds that has a maximum absorption wavelength (λmax) in the wavelength region of 280 to 400 nm.

[0390] The maximum absorption wavelength is measured by the following method.

[0391] A 0.1% by mass solution was prepared by dissolving the ultraviolet absorber in a good solvent. The prepared solution was used to measure the ultraviolet-visible absorption spectrum using a U-3010 spectrophotometer (manufactured by Hitachi High-Tech Science Corporation), and the wavelength representing the maximum absorbance was taken as the maximum absorption wavelength.

[0392] From the viewpoint of ease of fusion with the additive layer of the printing plate, organic compounds are preferred as ultraviolet absorbers.

[0393] Ultraviolet absorbers can be used alone or in combination with two or more.

[0394] Examples of compounds that are preferably used as ultraviolet absorbers include benzophenone compounds, benzotriazole compounds, triazine compounds, and cyanoacrylate compounds. From the viewpoints of ultraviolet absorption, ease of integration with the additive layer, and solubility in the coating liquid solvent, benzophenone compounds, benzotriazole compounds, and triazine compounds are more preferred, and benzotriazole compounds are even more preferred.

[0395] The amount of ultraviolet absorber added is preferably 0.1 to 5% by mass in the total solid content of the protective layer, more preferably 0.5 to 4% by mass, and even more preferably 1 to 3% by mass.

[0396] 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.

[0397] 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.

[0398] 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. Furthermore, it is also used in the synthesis of green soil.

[0399] Among mica compounds, fluorine-based swelling mica is particularly useful. That is, swelling synthetic mica has a thickness of... The stacked structure of the unit lattice layers exhibits more significant metal atom substitution within the lattice compared to other clay minerals. Consequently, the lattice layers suffer from a lack of positive charge, prompting the adsorption of Li atoms between the layers to compensate. + 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 breaks down, forming a stable sol in water. This tendency is strong in synthetic mica with swelling properties, making it particularly preferred.

[0400] From the perspective of controlling diffusion, the thinner the mica compound, the better; however, the larger the planar dimension, the better, as long as it does not impede the smoothness of the coating surface or the transmissibility of activated light. Therefore, the aspect ratio is preferably 20 or more, more preferably 100 or more, and especially preferably 200 or more. The aspect ratio is the ratio of the major axis to the thickness of the particle, and can be measured, for example, from the projection of a particle-based microscopic photograph. The larger the aspect ratio, the greater the effect obtained.

[0401] 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, when using a swollen synthetic mica as a representative compound, a thickness of 1–50 nm and a planar dimension (major diameter) of approximately 1–20 μm are preferred.

[0402] The content of inorganic layered compounds relative to the total solids content of the protective layer is preferably 0-60% by mass, more preferably 3-50% 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.

[0403] 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.

[0404] 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. 2More preferably 0.02~3g / m 2 Especially preferred is 0.02~1g / m 2 .

[0405] (Original plate for developing type offset printing on the second machine)

[0406] The second lithographic printing plate of the present invention will be described.

[0407] The support is the same as the support in the original developing type lithographic printing plate of the first machine mentioned above.

[0408] The image recording layer in the second lithographic printing original contains a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor.

[0409] a) the polymerizable compound, b) the infrared absorber, c) the polymerization initiator and d) the chromophore precursor are the same as a) the polymerizable compound, b) the infrared absorber, c) the polymerization initiator and d) the chromophore precursor in the image recording layer of the first lithographic printing plate original.

[0410] In the second lithographic printing original, the polymeric compound had four or more functions and a molecular weight of less than 15,000.

[0411] Furthermore, in the second lithographic printing plate original, the image recording layer contains e) an ultraviolet absorber. This ultraviolet absorber is the same as that contained in the protective layer of the first lithographic printing plate original.

[0412] The amount of ultraviolet absorber added is preferably 0.1 to 5% by mass in the total solids composition of the image recording layer, more preferably 0.5 to 4% by mass, and even more preferably 1 to 3% by mass.

[0413] The second lithographic printing original can have a protective layer on the image recording layer.

[0414] The protective layer can be the same as the protective layer in the first lithographic printing plate original. Furthermore, regarding the second lithographic printing plate original, the protective layer may or may not contain a UV absorber.

[0415] (Original plate for developing type offset printing on the 3rd machine)

[0416] The third lithographic printing plate of the present invention will be described.

[0417] The support is the same as the support in the original developing type lithographic printing plate of the first machine mentioned above.

[0418] The image recording layer in the third lithographic printing original contains a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor.

[0419] a) the polymerizable compound, b) the infrared absorber, c) the polymerization initiator and d) the chromophore precursor are the same as a) the polymerizable compound, b) the infrared absorber, c) the polymerization initiator and d) the chromophore precursor in the image recording layer of the first lithographic printing plate original.

[0420] The protective layer is the same as that of the first lithographic printing plate original. In the third lithographic printing plate original, the protective layer contains an ultraviolet absorber.

[0421] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the rate of disappearance of olefinic unsaturated bonds in the exposed region of the image recording layer relative to the unexposed region is 10% or more.

[0422] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the rate of disappearance of olefinic unsaturated bonds in the exposed region of the image recording layer relative to the unexposed region (hereinafter also referred to as "the rate of disappearance of olefinic unsaturated bonds during infrared laser exposure") is measured in the following manner.

[0423] (The disappearance rate of olefinic unsaturated bonds during infrared laser exposure)

[0424] Using the LuxelPLATESETTER T-6000III manufactured by Fujifilm Corporation, equipped with an 830nm infrared semiconductor laser, the obtained lithographic printing plate was processed at 120mJ / cm². 2 The exposure was performed using a specific method, resulting in an exposed image that includes both solid and non-image areas.

[0425] Next, using a HORIBA, Ltd. Fourier transform infrared spectrophotometer (FT-IR) "FT-720", the 1410 cm⁻¹ value originating from the olefinic unsaturated group was determined for the solid image portion and the non-image portion. -1 Near the peak area. At this time, the support of each lithographic printing plate is used as the background. The peak area of ​​the solid image part is set as S1, and the peak area of ​​the non-image part is set as S2. The disappearance rate of olefinic unsaturated bonds R1 [%) is calculated by the following formula 1.

[0426] R1=[1-(S1 / S2)]×100····(1)

[0427] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2When the image recording layer is exposed, there is no particular limit to the upper limit of the rate of disappearance of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer, but it is usually 60%, preferably 50%, and more preferably 40%.

[0428] The rate of disappearance of olefinic unsaturated bonds during infrared laser exposure is preferably 10-40%, more preferably 15-35%, and even more preferably 20-30%.

[0429] Good brush resistance can be obtained as long as the disappearance rate of olefinic unsaturated bonds is 10% or more. Furthermore, image reproduction in various images such as halftone dots becomes even better as long as the disappearance rate of olefinic unsaturated bonds is 40% or less, and is therefore preferred.

[0430] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When exposing the image recording layer, there is no particular limitation on the rate of disappearance of olefinic unsaturated bonds in the exposed region relative to the unexposed region of the image recording layer. However, it can be appropriately adjusted, for example, by setting the polymerizable compound in the image recording layer to a polymerizable compound with a specified functionality or higher. Furthermore, the rate of disappearance of olefinic unsaturated bonds can be appropriately adjusted by appropriately adjusting all the hydrogen abstraction enthalpies within the molecules of the chromophore precursor present in the image recording layer.

[0431] All hydrogen abstraction enthalpies present within the chromophore precursor molecule are as described above.

[0432] When the above image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%.

[0433] When the image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the rate of disappearance of olefinic unsaturated bonds in the exposed area relative to the unexposed area (hereinafter also referred to as "the rate of disappearance of olefinic unsaturated bonds during white lamp exposure") is measured in the following manner.

[0434] (The rate of disappearance of olefinic unsaturated bonds during white light exposure)

[0435] The original lithographic printing plate was exposed to a white fluorescent lamp to achieve an illuminance of 600 Lux on the printing plate. After one hour of exposure, the 1410 cm⁻¹ values ​​of the exposed and unexposed areas derived from the olefinic unsaturated groups were determined using a HORIBA, Ltd. Fourier transform infrared spectrophotometer (FT-IR) "FT-720". -1Near the peak area. At this time, the support of each lithographic printing plate is used as the background. The peak area of ​​the exposed part is set as S3, and the peak area of ​​the unexposed part is set as S4. The disappearance rate of olefinic unsaturated bonds R2 [%) is calculated by the following formula (2).

[0436] R2=[1-(S3 / S4)]×100····(2)

[0437] When the image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the rate of disappearance of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%, less than 5%, and more preferably less than 3%.

[0438] When the image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the lower limit of the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is preferably 0. Furthermore, as a preferred embodiment, the aforementioned lower limit is typically greater than 0.

[0439] When the image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, there is no particular limitation on the disappearance rate of olefinic unsaturated bonds in the exposed area relative to the unexposed area, but it can be appropriately adjusted, for example, by including an ultraviolet absorber in the protective layer of the lithographic printing plate.

[0440] (Original plate for developing type offset printing on the 4th machine)

[0441] The fourth lithographic printing plate of the present invention will be described.

[0442] The support is the same as the support in the original developing type lithographic printing plate of the first machine mentioned above.

[0443] The image recording layer in the fourth lithographic printing original contains a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor.

[0444] a) the polymerizable compound, b) the infrared absorber, c) the polymerization initiator and d) the chromophore precursor are the same as a) the polymerizable compound, b) the infrared absorber, c) the polymerization initiator and d) the chromophore precursor in the image recording layer of the first lithographic printing plate original.

[0445] Furthermore, in the fourth lithographic printing plate original, the image recording layer contains e) an ultraviolet absorber. This ultraviolet absorber is the same as that contained in the protective layer of the first lithographic printing plate original.

[0446] The amount of ultraviolet absorber added is preferably 0.1 to 5% by mass in the total solids composition of the image recording layer, more preferably 0.5 to 4% by mass, and even more preferably 1 to 3% by mass.

[0447] The fourth lithographic printing original can have a protective layer on the image recording layer.

[0448] The protective layer can be the same as the protective layer in the first lithographic printing plate original. Additionally, regarding the fourth lithographic printing plate original, the protective layer may or may not contain a UV absorber.

[0449] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the rate of disappearance of olefinic unsaturated bonds in the exposed region of the image recording layer relative to the unexposed region is 10% or more.

[0450] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the rate of disappearance of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is also within the same preferred range as described in the original developing type lithographic printing plate for the third machine.

[0451] When the above image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%.

[0452] When the image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the rate of disappearance of olefinic unsaturated bonds in the exposed region relative to the unexposed region is also within the preferred range as described in the original developing type lithographic printing plate for the third machine.

[0453] Furthermore, when the image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, there is no particular limitation on the disappearance rate of olefinic unsaturated bonds in the exposed area relative to the unexposed area, but it can be appropriately adjusted, for example, by including an ultraviolet absorber in the image recording layer using a lithographic printing plate.

[0454] In on-machine developing lithographic printing plates, the image recording layer can contain polymeric compounds, chain transfer agents, low-molecular-weight hydrophilic compounds, sensitizers, and other components.

[0455] (polymers)

[0456] Polymer compounds can function as adhesive polymers in image recording layers, or they can exist in image recording layers as polymer particles.

[0457] <Adhesive Polymer>

[0458] As an adhesive polymer, polymers with film-forming properties are preferred, and (meth)acrylic resin, polyvinyl acetal resin, polyurethane resin, etc. are preferred examples.

[0459] As the adhesive polymer used in the image recording layer, an adhesive polymer having an epoxy chain is preferred. The adhesive polymer having an epoxy chain can have poly(epoxy) sites in the main chain or in the side chains. Furthermore, it can be a graft polymer with poly(epoxy) sites in the side chains, or a block copolymer consisting of blocks composed of repeating units containing poly(epoxy) sites and blocks composed of repeating units not containing (epoxy) sites.

[0460] When the main chain has a poly(epoxy) site, polyurethane resin is preferred. Examples of polymers whose main chain has a poly(epoxy) site in the side chain include (meth)acrylic resin, polyvinyl acetal resin, polyurethane resin, polyurea resin, polyimide resin, polyamide resin, epoxy resin, polystyrene resin, phenolic varnish-type phenolic resin, polyester resin, synthetic rubber, and natural rubber, with (meth)acrylic resin being particularly preferred.

[0461] As an epoxide, epoxides with 2 to 6 carbon atoms are preferred, and ethylene oxide or propylene oxide are particularly preferred.

[0462] 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.

[0463] If the number of repetitions of the epoxy alkane is 120 or less, the reduction in brush resistance caused by abrasion and the reduction in brush resistance caused by the deterioration of ink acceptability can be suppressed, and therefore it is preferred.

[0464] 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).

[0465] [Chemical Formula 10]

[0466]

[0467] 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.

[0468] As a monovalent organic group, an alkyl group having 1 to 6 carbon atoms is preferred. 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.

[0469] 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 a hydrogen atom. R2 is especially preferably a hydrogen atom or a methyl group.

[0470] 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.

[0471] Examples of polymers with olefinic unsaturated bonds in the main chain of the molecule include poly-1,4-butadiene and poly-1,4-isoprene.

[0472] Examples of polymers having olefinically unsaturated bonds in the side chains of a molecule include polymers that are esters or amides of acrylic acid or methacrylic acid, and whose ester or amide residues (R of -COOR or -CONHR) have olefinically unsaturated bonds.

[0473] 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 is in the formula) 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.

[0474] 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).

[0475] Specific examples of amide residues include -CH2CH=CH2, -CH2CH2-Y (where Y represents a cyclohexene residue), and -CH2CH2-OCO-CH=CH2.

[0476] 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.

[0477] From the viewpoint of good sensitivity and good storage stability, the content of crosslinking groups (the content of unsaturated double bonds that can undergo free radical polymerization by iodine titration) in the adhesive polymer is preferably 0.1 to 10.0 mmol per 1 g of adhesive polymer, more preferably 1.0 to 7.0 mmol, and even more preferably 2.0 to 5.5 mmol.

[0478] 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 ​​listed together with each repeating unit (the values ​​listed together with the repeating units in the main chain) represent the molar percentage of the repeating unit. The values ​​listed together with the 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.

[0479] [Chemical Formula 11]

[0480] (1)

[0481] (2)

[0482] (3)

[0483] (4)

[0484] (5)

[0485] (6)

[0486] (7) [Chemical Formula 12]

[0487] (8)

[0488] (9)

[0489] (10)

[0490] (11)

[0491]

[0492] Regarding the molecular weight of the adhesive polymer, as a GPC-based conversion value for polystyrene, the mass-average molecular weight (Mw) is 2,000 or more, preferably 5,000 or more, and more preferably 10,000 to 300,000.

[0493] As needed, 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 together.

[0494] The adhesive polymer can be used alone or in combination with two or more.

[0495] The content of the adhesive polymer in the total solids composition of the image recording layer is preferably 1 to 90% by mass, more preferably 5 to 80% by mass.

[0496] <Polymer compounds in particle form (polymer particles)>

[0497] 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).

[0498] 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.

[0499] Specific examples of polymers constituting the hydrophobic thermoplastic polymer particles include homopolymers or copolymers or mixtures thereof of monomers such as ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, acrylates or methacrylates having a polyalkylene structure, etc. 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.

[0500] 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.

[0501] The thermally reactive groups in polymer particles, if forming chemical bonds, can be functional groups capable of any reaction, and polymerizable groups are preferred. 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.

[0502] Examples of microcapsules 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 an 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.

[0503] 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.

[0504] To microencapsulate or microgel the components of this image recording layer, known methods can be used.

[0505] 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.

[0506] Polymer particles can be used alone or in combination with two or more types.

[0507] The content of polymer particles in the total solids composition of the image recording layer is preferably 5 to 90% by mass, more preferably 5 to 80% by mass, and even more preferably 10 to 75% by mass.

[0508] As a preferred embodiment, the polymer particles preferably have a hydrophobic backbone and contain the following two types of constituent units:

[0509] i) A constituent unit having a cyano side group directly bonded to the aforementioned hydrophobic main chain; and

[0510] ii) Constituents having side groups containing hydrophilic poly(epoxy) segments.

[0511] Acrylic resin chains are preferred as the hydrophobic backbone mentioned above.

[0512] Examples of the cyano side groups mentioned above are preferably -[CH2CH(C≡N)-] or -[CH2C(CH3)(C≡N)-].

[0513] 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.

[0514] Furthermore, the epoxide in the hydrophilic poly(epoxide) segment is preferably ethylene oxide or propylene oxide, and more preferably ethylene oxide.

[0515] 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.

[0516] 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.

[0517] As a preferred method, the polymer particles are preferably obtained by reacting a polyisocyanate compound with 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 isophorone diisocyanate.

[0518] 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.

[0519] Polymer particles can be used alone or in combination with two or more types.

[0520] The content of polymer particles in the total solids composition of the image recording layer is preferably 5 to 90% by mass, more preferably 5 to 80% by mass, and even more preferably 10 to 75% by mass.

[0521] The polymeric compounds contained in the image recording layer are preferably polymeric compounds comprising building blocks derived from styrene compounds and / or building blocks derived from acrylonitrile compounds. From the viewpoint of improving on-machine developability, these polymeric compounds are preferably used as adhesive polymers or polymer particles.

[0522] 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.

[0523] Examples of acrylonitrile compounds include acrylonitrile and methacrylonitrile, with acrylonitrile being the preferred choice.

[0524] In polymeric compounds containing styrene compounds and acrylonitrile compounds as constituent units, the composition ratio of constituent units derived from styrene compounds to constituent units derived from acrylonitrile compounds is preferably 4:1 to 1:4.

[0525] (Chain transfer agent)

[0526] Chain transfer agents help improve the brush resistance of lithographic printing plates made from lithographic master plates.

[0527] As a chain transfer agent, thiols are preferred, and from the viewpoint of boiling point (low volatility), thiols with 7 or more carbon atoms are more preferred, and compounds having a thiol group on the aromatic ring (aromatic thiols) are even more preferred. The thiols are preferably monofunctional thiols.

[0528] The following compounds can be cited as specific examples of chain transfer agents.

[0529] [Chemical Formula 13]

[0530]

[0531] [Chemical Formula 14]

[0532]

[0533] [Chemical Formula 15]

[0534]

[0535] [Chemical Formula 16]

[0536]

[0537] Chain transfer agents can be used alone or in combination with two or more.

[0538] The chain transfer agent content in the total solids component of the image recording layer is preferably 0.01 to 50% by mass, more preferably 0.05 to 40% by mass, and even more preferably 0.1 to 30% by mass.

[0539] -Low molecular weight hydrophilic compounds-

[0540] Low-molecular-weight hydrophilic compounds do not reduce the brush resistance of lithographic printing plates made from lithographic printing plates, but rather help improve the on-machine developability of the lithographic printing plates. The low-molecular-weight hydrophilic compounds are preferably compounds with a molecular weight of less than 1,000, more preferably compounds with a molecular weight of less than 800, and even more preferably compounds with a molecular weight of less than 500.

[0541] Examples of low-molecular-weight hydrophilic compounds, such as water-soluble organic compounds, include glycols and their ether or ester derivatives such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol; polyols such as glycerol, pentaerythritol, and tris(2-hydroxyethyl)isocyanurate; organic amines and their salts such as triethanolamine, diethanolamine, and monoethanolamine; organic sulfonic acids and their salts such as alkyl sulfonic acids, p-toluenesulfonic acid, and benzenesulfonic acid; organic aminosulfonic acids and their salts such as alkyl aminosulfonic acids; organic sulfuric acids and their salts such as alkyl sulfuric acid and alkyl ether sulfuric acid; organic phosphonic acids and their salts such as phenylphosphonic acid; organic carboxylic acids and their salts such as tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, and amino acids; and betaine.

[0542] The low-molecular-weight hydrophilic compound is preferably selected from at least one of polyols, organic sulfates, organic sulfonates, and betaines.

[0543] Regarding low molecular weight hydrophilic compounds, the low molecular weight hydrophilic compounds described in International Publication No. 2020 / 137919

[0145] to

[0147] can be used.

[0544] Low molecular weight hydrophilic compounds have small hydrophobic structures and almost no surface activity, so the dampening solution will not penetrate the exposure part (image part) of the image recording layer and reduce the hydrophobicity or film strength of the image part, thus maintaining the ink acceptability and brush resistance of the image recording layer well.

[0545] Low molecular weight hydrophilic compounds can be used alone or in combination with two or more.

[0546] The content of low molecular weight hydrophilic compounds in the total solids composition of the image recording layer is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, and even more preferably 2 to 10% by mass.

[0547] (Sensitizer)

[0548] Sensitizers help improve the ink adhesion (hereinafter, also simply "ink adhesion") of inks 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 function as surface coating agents for the inorganic layered compounds, inhibiting the reduction in ink adhesion during printing caused by the inorganic layered compounds.

[0549] 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.

[0550] Regarding the sensitizer, the sensitizers described in International Publication No. 2020 / 137919,

[0151] to

[0155] , can be used.

[0551] The sensitizer content in the total solids component of the image recording layer 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.

[0552] (Other ingredients)

[0553] 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.

[0554] The content of non-particulate polymeric compounds with a weight-average molecular weight exceeding 15,000 in the total solids composition of the image recording layer is preferably 5% by mass or less, more preferably 4% by mass or less.

[0555] (Formation of the image recording layer)

[0556] The image recording layer can be formed, for example, by preparing a coating solution by appropriately dispersing or dissolving the necessary components in a known solvent, 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.

[0557] From the viewpoint of providing developability on the machine, 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.

[0558] In-machine developing lithographic printing plates can have an undercoat layer (sometimes called an intermediate layer) between the image recording layer and the support.

[0559] The on-machine developing lithographic printing plate master may or may not have a protective layer on the image recording layer. The protective layer is as described above.

[0560] [Undercoat]

[0561] The undercoat layer enhances the adhesion between the support and the image recording layer in the exposed section and facilitates the peeling of the image recording layer from the support in the unexposed section, thus improving developability without compromising brush resistance. Furthermore, in the case of infrared laser exposure, the undercoat layer functions as a heat insulation layer, thereby preventing the heat generated by exposure from diffusing to the support and reducing sensitivity.

[0562] Examples of compounds used in the primer coating include polymers having adsorbent and hydrophilic groups that can be adsorbed onto the surface of the support. To improve adhesion to the image recording layer, polymers having adsorbent and hydrophilic groups, as well as crosslinking groups, are preferred. The compounds used in the primer coating can be low-molecular-weight compounds or polymers. Two or more compounds used in the primer coating may be mixed as needed.

[0563] 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.

[0564] As adsorbent groups capable of adsorbing onto the surface of the support, phenolic hydroxyl groups, carboxyl groups, -PO3H2, -OPO3H2, -CONHSO2-, -SO2NHSO2-, and -COCH2COCH3 are preferred. As hydrophilic groups, sulfonyl groups or their salts, and carboxyl salts are preferred. As crosslinking groups, acryloyl groups, methacryloyl groups, acrylamide groups, methacrylamide groups, and allyl groups are preferred.

[0565] 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 be further copolymerized with monomers other than those described above, preferably hydrophilic monomers.

[0566] Specifically, preferred examples include silane coupling agents having olefinic double-bond reactive groups capable of addition polymerization as described in Japanese Patent Application Publication No. 10-282679, and phosphorus compounds having olefinic double-bond reactive groups as described in Japanese Patent Application Publication No. 2-304441. Low-molecular-weight or high-molecular-weight compounds having crosslinking groups (preferably olefinic unsaturated groups), functional groups interacting with the support surface, and hydrophilic groups as described in Japanese Patent Application Publication Nos. 2005-238816, 2005-125749, 2006-239867, and 2006-215263 are also preferred.

[0567] As a more preferred compound, examples include the polymers described in Japanese Patent Application Publication Nos. 2005-125749 and 2006-188038, which are adsorbent groups that can be adsorbed onto the surface of a support, and polymers having hydrophilic groups and crosslinking groups.

[0568] The content of olefinic unsaturated groups in the polymer used in the primer coating is preferably 0.1 to 10.0 mmol per 1g of polymer, more preferably 0.2 to 5.5 mmol.

[0569] The polymer used in the base coating has a mass-average molecular weight (Mw) of 5,000 or more, and more preferably 10,000 to 300,000.

[0570] 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, hydroxyethyl ethylenediamine triacetic acid, dihydroxyethyl ethylenediamine diacetic acid, hydroxyethyl iminodiacetic acid, etc.) to prevent contamination over time.

[0571] The primer layer can be formed by applying and drying using known methods. The preferred coating weight (solid content) of the dried primer layer is 0.1–100 mg / m³. 2 More preferably 1-30 mg / m 2 .

[0572] The on-machine developing type lithographic printing plate master involved in this invention can have a collapsed edge shape at the end.

[0573] Figure 3 This is a schematic diagram showing the cross-sectional shape of the end of the original lithographic printing plate.

[0574] exist Figure 3 In 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".

[0575] 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 deterioration 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 remaining 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 contamination. 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 printing ink may accumulate in these cracks, becoming a cause of edge contamination. 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.

[0576] 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 exhibit edge collapse, similar to the image recording layer 1a.

[0577] 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.

[0578] 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.

[0579] Figure 4 This 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 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.

[0580] Preferably, an ink-repellent agent is applied to part or all of the side surfaces of the two opposing edges of the original offset printing plate. By applying an ink-repellent agent to part or all of the side surfaces of the two opposing edges at the end having this collapsed edge shape, edge contamination at the edge end can be suppressed. There are no particular limitations on the ink-repellent agent, as long as it can repel ink; however, hydrophilic agents or desensitizing solutions can be used, for example. The materials used as ink-repellent agents will be described below.

[0581] (Hydrophilic agent)

[0582] Phosphoric acid compounds are one of the preferred hydrophilic agents. Phosphoric acid compounds include phosphoric acid, its salts, and its esters. Examples include phosphoric acid, metaphosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium tripolyphosphate, potassium pyrophosphate, and sodium hexametaphosphate. Among these, sodium dihydrogen phosphate, disodium hydrogen phosphate, or sodium hexametaphosphate are preferred.

[0583] As a phosphoric acid compound, a polymeric compound is preferred, and a polymeric compound having a phosphate ester group is more preferred. Examples of polymeric compounds having a phosphate ester group include polymers containing one or more monomers having a phosphate ester group in the molecule, copolymers containing one or more monomers having a phosphate ester group and one or more monomers not having a phosphate ester group, and polymers formed by introducing a phosphate ester group into a polymer that does not have a phosphate ester group through a polymerization reaction.

[0584] In polymers containing phosphate groups, the content of repeating units containing phosphate groups is preferably 1 to 100 mol%, more preferably 5 to 100 mol%, and even more preferably 10 to 100 mol%, relative to the total repeating units of the polymer. The mass-average molecular weight of the polymer containing phosphate groups is preferably 5,000 to 1,000,000, more preferably 7,000 to 700,000, and even more preferably 10,000 to 500,000.

[0585] Phosphonic acid compounds are one of the preferred hydrophilizing agents. Phosphonic acid compounds include phosphonic acids, their salts, and their esters. Examples include ethylphosphonic acid, propylphosphonic acid, isopropylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, dodecylphosphonic acid, octadecylphosphonic acid, 2-hydroxyethylphosphonic acid and their sodium or potassium salts, alkylphosphonic acid monoalkyl esters such as methyl methyl methyl methyl ethyl phosphonic acid and their sodium or potassium salts, alkyl diphosphonic acids such as methylene diphosphonic acid and ethylene diphosphonic acid and their sodium or potassium salts, and polyvinylphosphonic acid.

[0586] One preferred method for hydrophilizing agents is using water-soluble resins. Examples of water-soluble resins include those classified as polysaccharides, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide and its copolymers, vinyl methyl ether / maleic anhydride copolymers, vinyl acetate / maleic anhydride copolymers, and styrene / maleic anhydride copolymers. Examples of polysaccharides include starch derivatives (e.g., dextrin, enzymatically hydrolyzed dextrin, hydroxypropylated starch, carboxymethylated starch, phosphorylated starch, polyoxyalkylene grafted starch, and cyclodextrin), cellulose derivatives (e.g., carboxymethyl cellulose, carboxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, and methylpropyl cellulose), carrageenan, alginate, guar gum, locust bean gum, xanthan gum, gum arabic, and soybean polysaccharides. Preferably, water-soluble resins include dextrin, starch derivatives such as polyoxyalkylene grafted starch, gum arabic, carboxymethyl cellulose, or soybean polysaccharides.

[0587] One preferred method for hydrophilizing agents is to use anionic surfactants and nonionic surfactants. As anionic surfactants, the surfactant described in Japanese Patent Application Publication No. 2014-104631, number

[0022] , is an example, and this content is incorporated herein by reference. As anionic surfactants, dialkyl sulfosuccinates, alkyl sulfates, polyoxyethylene aryl ether sulfates, or alkylnaphthalene sulfonates are preferred. As anionic surfactants, anionic surfactants represented by general formula (IA) or general formula (1-B) are preferred.

[0588] [Chemical Formula 17]

[0589]

[0590] In the general formula (IA), R 1 Indicates an alkyl group with 1 to 20 carbon atoms, whether straight or branched; p represents 0, 1, or 2; Ar 1 Indicates an aryl group with 6 to 10 carbon atoms, where q represents 1, 2, or 3, M1 + Na represents + K + Li + or NH4 + When p is 2, there exist multiple R. 1 They can be the same as each other, or they can be different from each other.

[0591] In the general formula (IB), R 2 Indicates an alkyl group with 1 to 20 carbon atoms, whether straight or branched, where m represents 0, 1, or 2, and Ar... 2 Y represents an aryl group with 6 to 10 carbon atoms, Y represents a single bond or an alkylene group with 1 to 10 carbon atoms, and R represents an aryl group with 6 to 10 carbon atoms. 3M2 represents a linear or branched alkylene group with 1 to 5 carbon atoms, where n represents an integer from 1 to 100. + Na represents + K + Li + or NH4 + When m is 2, there exist multiple R. 2 They can be the same or different. When n is 2 or more, there exist multiple Rs. 3 They can be the same as each other, or they can be different from each other.

[0592] In general formulas (IA) and (IB), R 1 and R 2 CH3, C2H5, C3H7, or C4H9 are preferred. 3 Preferably -CH2-, -CH2CH2-, -CH2CH2CH2-, or -CH2CH(CH2)-, more preferably -CH2CH2-. p and m are preferably 0 or 1, p is more preferably 0. Y is preferably a single bond. n is preferably an integer from 1 to 20.

[0593] As nonionic surfactants, examples include those described in paragraph

[0031] of Japanese Patent Application Publication No. 2014-104631, the contents of which are incorporated herein by reference. Polyoxyethylene aryl ethers and polyoxyethylene-polyoxypropylene block copolymers are preferred as nonionic surfactants.

[0594] As a nonionic surfactant, a nonionic surfactant represented by general formula (II-A) is preferred.

[0595] [Chemical Formula 18]

[0596] (R 4 ) s ——Ar 3 ——O(CH2CH2O) t (CH2CH(CH3)O) u H (II-A)

[0597] In general formula (II-A), R 4 Indicates an alkyl group having 1 to 20 hydrogen or carbon atoms, where s represents 0, 1, or 2, and Ar represents... 3 The aryl group represents 6 to 10 carbon atoms, and t and u represent integers from 0 to 100, neither of which is 0. When s is 2, there can be multiple R4 groups that are identical or distinct.

[0598] Alternatively, organic resin microparticles (e.g., microgels) can be used as hydrophilic agents. Microgels are reactive or non-reactive resin particles dispersed in an aqueous medium. Microgels preferably have polymeric groups in or on their particle surface.

[0599] The coating solution containing the hydrophilic agent is preferably in the form of an aqueous solution in which the hydrophilic agent is dissolved or dispersed in a medium mainly containing water. The content of the hydrophilic agent in the coating solution is preferably 0.05–50% by mass, more preferably 0.1–30% by mass. The viscosity of the coating solution containing the hydrophilic agent at 25°C is preferably 0.5–1000 mPa·s, more preferably 1–100 mPa·s. The surface tension of the coating solution containing the hydrophilic agent at 25°C is preferably 25–70 mN / m, more preferably 40–65 mN / m.

[0600] In addition to hydrophilic agents, coating solutions containing hydrophilic agents may also contain organic solvents, plasticizers, preservatives, defoamers, and inorganic salts such as nitrates and sulfates.

[0601] (Desensitizing solution)

[0602] Examples of desensitizing solutions include aqueous solutions containing at least one of a hydrophilic organic polymer, hexametaphosphate and its salts, and phytic acid and its salts. Specific examples of hydrophilic organic polymers include gum arabic, dextrin, alginates such as sodium alginate, water-soluble celluloses such as carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, water-soluble copolymers containing acrylamide units, polyacrylic acid, copolymers containing acrylic acid units, polymethacrylic acid, copolymers containing methacrylic acid units, copolymers of vinyl methyl ether and maleic anhydride, copolymers of vinyl acetate and maleic anhydride, and phosphoric acid-modified starch. Gum arabic is preferred due to its strong desensitizing effect. Two or more of these hydrophilic polymers can be used in combination as needed, at a concentration of about 1 to 40% by weight, more preferably 3 to 30% by weight.

[0603] Specific examples of hexametaphosphates include alkali metal salts or ammonium salts of hexametaphosphate. Examples of alkali metal salts or ammonium salts of hexametaphosphate include sodium hexametaphosphate, potassium hexametaphosphate, and ammonium hexametaphosphate. Specific examples of phytic acid or its salts include alkali metal salts such as sodium salts, potassium salts, and lithium salts, as well as ammonium salts and amine salts. Examples of amine salts include salts of diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-propylamine, n-butylamine, n-pentylamine, n-hexylamine, laurylamine, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, ethanolamine, diethanolamine, triethanolamine, allylamine, and aniline. Phytates can be normal salts in which all 12 hydrogen atoms of the acid are substituted, hydrogen salts in which some hydrogen atoms of the acid are substituted (acidic salts), and can also be used in any form, including single salts containing one type of base and complex salts containing two or more types of bases. These compounds can be used alone or in combination of two or more.

[0604] In this embodiment, the desensitizing solution preferably also contains a metal salt of a strong acid, thereby enhancing the desensitization effect. Specific examples of strong acid metal salts include sodium, potassium, magnesium, calcium, and zinc salts of nitric acid; sodium, potassium, magnesium, calcium, and zinc salts of sulfuric acid; sodium, potassium, magnesium, calcium, and zinc salts of chromic acid; and sodium fluoride and potassium fluoride. Two or more of these strong acid metal salts can be used in combination, and their amount is preferably about 0.01 to 5% by weight based on the total weight of the desensitizing solution. In the desensitizing solution used in this invention, the pH value is adjusted to an acidic range, more preferably to 1 to 5, and most preferably to 1.5 to 4.5. Therefore, if the pH of the aqueous phase is not acidic, acid is further added to the aqueous phase. Examples of acids added as pH adjusters include inorganic acids such as phosphoric acid, sulfuric acid, and nitric acid, and organic acids such as citric acid, tannic acid, malic acid, glacial acetic acid, lactic acid, oxalic acid, p-toluenesulfonic acid, and organophosphonic acids. Phosphoric acid not only functions as a pH adjuster but also enhances the desensitization effect, making it particularly superior. It is preferably contained in the range of 0.01 to 20% by weight, and most preferably 0.1 to 10% by weight, relative to the total weight of the desensitizing solution.

[0605] In this embodiment, the desensitizing liquid preferably contains a wetting agent and / or a surfactant, thereby improving the spreadability of the desensitizing liquid. Specifically, lower polyols are preferred as wetting agents, such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, glycerol, sorbitol, pentaerythritol, etc., with glycerol being particularly preferred. Furthermore, as surfactants, nonionic surfactants such as polyoxyethylene alkylphenyl ethers and polyoxyethylene polyoxypropylene block copolymers, anionic surfactants such as fatty acid salts, alkyl sulfate hydrochlorides, alkylbenzene sulfonates, alkylnaphthalene sulfonates, dialkyl sulfosuccinate salts, alkyl phosphate salts, and naphthalene sulfonate formalin condensates, and amphoteric surfactants such as betaine-type, glycine-type, alanine-type, and sulfobetaine-type surfactants can be used. These wetting agents and / or surfactants are contained in the desensitizing liquid in the range of about 0.5 to 10% by weight, more preferably 1 to 5% by weight, relative to the total weight of the desensitizing liquid. The desensitizing liquid used in this invention may also contain up to 2% by weight of fillers such as silica, talc, and clay, and may also contain up to 1% by weight of dyes or pigments.

[0606] As described above, the desensitizing solution used in this embodiment contains a hydrophilic aqueous solution. However, considering the possibility of adverse effects on the image recording layer, emulsion-type desensitizing solutions as described in the specifications of U.S. Patent Nos. 4,253,999, 4,268,613, and 4,348,954 can also be used.

[0607] As an ink repellent, HN-G5 (manufactured by Fujifilm Corporation) can be used, for example.

[0608] (Ink repellent coating method)

[0609] There are no particular restrictions on the application method of the ink repellent. Figure 7 This diagram illustrates the coating method for applying an ink-repellent agent. (Example) Figure 7 As shown, the coating liquid containing the ink repellent can be coated by the bar 138. Additionally, in Figure 7In order to explain the method of applying the ink repellent, the lithographic printing plate 100a having an outermost surface 122 of a specific structural layer based on a support is described in a simplified manner, and the shape of the collapsed edge at the end is not described. When applying the ink repellent with the rod 138, the coating liquid containing the ink repellent is first applied to the rod 138. The rod 138 is moved so that the coated rod 138 is along the end face 120 (side surface of the aluminum support) of the lithographic printing plate 100a. As for the moving speed of the rod 138, it can be moved at, for example, 20 mm / s. After coating, the coating liquid is dried. As for the drying conditions, drying can be carried out, for example, by blowing air at a speed of 6 m / s and a temperature of 80°C for 30 seconds.

[0610] In addition, the size of the bar can be appropriately changed according to the thickness of the aluminum support of the lithographic printing plate original 100a, but for example, if the thickness of the aluminum support is 0.3mm, the #10 bar can be used.

[0611] Furthermore, when applying the coating liquid, such as Figure 7 As shown, the coating can be applied by tilting the bar 138 at an angle θ relative to the end face 120 of the lithographic printing plate 100a.

[0612] As a method for coating part or all of the sides of the two opposing edges of the original offset printing plate, the method described in Japanese Patent No. 6628949 is preferred.

[0613] 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 with reference to the above-mentioned support.

[0614] 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.

[0615] 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).

[0616] 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.

[0617] 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.

[0618] 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.

[0619] 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.

[0620] 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.

[0621] 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.

[0622] The arithmetic mean height Sa on the outermost surface was measured according to the method described in ISO 25178. Specifically, using a Micromap MM3200-M100 manufactured by Ryoka Systems Inc., measurements were taken at three or more locations selected from the same sample, and their average value 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 measured.

[0623] To achieve the necessary condition that the arithmetic mean height Sa of the outermost surface is 0.3 to 20 μm, it is preferable that the outermost layer is formed with an uneven shape.

[0624] Specifically, examples include a method where the outermost layer comprises 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 %).

[0625] 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.

[0626] Preferred organic resin particles include synthetic resins such as poly(meth)acrylates, polystyrene and its derivatives, polyamides, polyimides, low-density polyethylene, high-density polyethylene, polypropylene and other polyolefins, polyurethanes, polyureas, polyesters and other synthetic resins, as well as particles containing natural polymers such as chitin, chitosan, cellulose, cross-linked starch, cross-linked cellulose and other natural polymers.

[0627] Among them, synthetic resin particles have the advantages of easy control of particle size and easy control of desired surface properties through surface modification.

[0628] Regarding the manufacturing method of organic resin particles, polymethyl methacrylate (PMMA), a relatively hard resin, can be micronized using a crushing method. However, from the viewpoint of easy control and precision of particle size, the method of synthesizing particles by emulsion suspension polymerization is preferred.

[0629] The manufacturing methods of organic resin particles are detailed in "Ultra-fine particles and materials" edited by the Japanese Society for Materials Science, published by Shokabo in 1993, and "Production and application of microparticles / powders" edited by Haruma Kawaguchi, published by CMC Publishing in 2005, etc.

[0630] Organic resin particles are also available as commercially available products, such as those manufactured by Soken Chemical & Engineering Co., Ltd., including crosslinked acrylic resins MX-40T, MX-80H3wT, MX-150, MX-180TA, MX-300, MX-500, MX-1000, MX-1500H, MR-2HG, MR-7HG, MR-10HG, MR-3GSN, MR-5GSN, MR-7G, MR-10G, MR-5C, MR-7GC, and styrene resins SX-350H, SX-500H, and those from Sekisui Plastics. Co., Ltd. manufactures acrylic resins MBX-5, MBX-8, MBX-12, MBX-15, MBX-20, MB20X-5, MB30X-5, MB30X-8, MB30X-20, SBX-6, SBX-8, SBX-12, SBX-17. Mitsui Chemicals, Inc. manufactures polyolefin resins, including CHEMIPEARL W100, W200, W300, W308, W310, W400, W401, W405, W410, W500, WF640, W700, W800, W900, W950, WP100, etc.

[0631] Examples of inorganic particles include silicon dioxide, aluminum oxide, zirconium oxide, titanium dioxide, carbon black, graphite, BaSO4, ZnS, MgCO3, CaCO3, ZnO, CaO, WS2, MoS2, MgO, SnO2, α-Fe2O3, α-FeOOH, SiC, CeO2, BN, SiN, MoC, BC, WC, titanium carbide, corundum, synthetic diamond, garnet, silica, weathered silica (Triboli), diatomaceous earth, and dolomite.

[0632] The aforementioned particles are preferably particles with hydrophilic surfaces. Particles with hydrophilic surfaces include organic resin particles with hydrophilic surfaces and inorganic particles with hydrophilic surfaces.

[0633] Organic resin particles with a hydrophilic surface are preferably organic resin particles coated with at least one inorganic compound selected from silica, alumina, titanium dioxide and zirconium oxide, and are particularly preferably organic resin particles coated with silica.

[0634] The organic resin constituting the organic resin particles with a hydrophilic surface is preferably selected from at least one resin selected from polyacrylic resins, polyurethane resins, polystyrene resins, polyester resins, epoxy resins, phenolic resins and melamine resins.

[0635] The following detailed description of organic resin particles with hydrophilic surfaces will focus on organic resin particles coated with silica (hereinafter also referred to as "silica-coated organic resin particles"). However, organic resin particles with hydrophilic surfaces are not limited to this.

[0636] The silica-coated organic resin particles are particles whose surface is coated with silica to form organic resin particles. Preferably, the organic resin particles constituting the core will not soften or become sticky due to moisture or temperature in the air.

[0637] Examples of organic resins that constitute the organic resin particles in the silica-coated organic resin particles include polyacrylic resins, polyurethane resins, polystyrene resins, polyester resins, epoxy resins, phenolic resins, and melamine resins.

[0638] As materials for forming a silica layer on the surface of organic resin particles coated with silica, compounds having alkoxysilane groups, such as condensates of alkoxysiloxane compounds, are preferred, and siloxane materials are particularly preferred. Specifically, silica particles such as silica sol, colloidal silica, and silica nanoparticles are preferred.

[0639] The structure of organic resin particles coated with silica can be either a structure in which silica particles are attached to the surface of organic resin particles as a solid component, or a structure in which a siloxane compound layer is formed on the surface of organic resin particles by the condensation reaction of alkoxysiloxane compounds.

[0640] Silica does not necessarily have to coat the entire surface of the organic resin particles; preferably, it is coated at least 0.5% by mass relative to the total mass of the organic resin particles. That is, silica is present in at least a portion of the surface of the organic resin particles, thereby improving the affinity with water-soluble polymers, such as polyvinyl alcohol (PVA), that coexist on the surface of the organic particles, and suppressing particle shedding even under external stress, maintaining excellent scratch resistance and ease of peeling when laminated without backing paper. Therefore, "coated with silica" also includes the state in which silica is present in at least a portion of the surface of the organic resin particles.

[0641] The surface coating state of silica can be confirmed by morphological observation using scanning electron microscopy (SEM). Furthermore, the amount of silica coating can be confirmed by detecting Si atoms using elemental analysis such as fluorescence X-ray analysis and calculating the amount of silica present in the Si atoms.

[0642] There are no particular limitations on the manufacturing method of organic resin particles coated with silica. It can be a method in which silica particles or silica precursor compounds coexist with monomer components of raw materials that become organic resin particles to form organic resin particles while simultaneously forming a silica surface coating layer. Alternatively, it can be a method in which silica particles are physically attached to the surface after the organic resin particles are formed and then immobilized.

[0643] The following is an example of a method for manufacturing organic resin particles coated with silica. First, silica and a raw material resin (more specifically, a raw material resin such as a monomer capable of suspension polymerization, a prepolymer capable of suspension crosslinking, or a resin liquid constituting the aforementioned organic resin) are added to water containing a suspension stabilizer appropriately selected from water-soluble polymers such as polyvinyl alcohol, methylcellulose, and polyacrylic acid, or inorganic suspending agents such as calcium phosphate and calcium carbonate, and the mixture is stirred and mixed to prepare a suspension in which silica and the raw material resin are dispersed. At this time, by adjusting the type, concentration, and stirring speed of the suspension stabilizer, a suspension with a target particle size can be formed. Next, the suspension is heated to initiate a reaction, and the resin raw material is subjected to suspension polymerization or suspension crosslinking to generate resin particles. At this time, the coexisting silica is fixed to the resin particles that have been cured by the polymerization or crosslinking reaction, especially near the surface of the resin particles due to this physical property. Then, the suspension is subjected to solid-liquid separation, and the suspension stabilizer adhering to the particles is removed by washing and then dried. In this way, approximately spherical organic resin particles coated with silica with the desired particle size can be obtained by fixing silica.

[0644] Thus, it is possible to obtain silica-coated organic resin particles of the desired particle size by controlling the conditions during suspension polymerization or suspension crosslinking, and it is also possible to obtain silica-coated organic particles of the desired size by means of sieve filtration after generating silica-coated organic resin particles without strictly controlling them.

[0645] Regarding the amount of raw materials added to the mixture when manufacturing organic particles coated with silica by the above method, for example, the following method is preferred: when the total amount of raw material resin and silica is 100 parts by mass, first add 0.1 to 20 parts by mass of suspending stabilizer to 200 to 800 parts by mass of water as the dispersion medium, and fully dissolve or disperse it. Then, add the above-mentioned 100 parts by mass of the raw material resin and silica mixture to the liquid, and stir while adjusting the stirring speed to disperse the particles to a specified particle size. After adjusting the particle size, the liquid temperature is raised to 30 to 90°C and the reaction is carried out for 1 to 8 hours.

[0646] Regarding the method for manufacturing organic resin particles coated with silica, the above-described method is one example. For example, organic resin particles coated with silica obtained by the methods detailed in Japanese Patent Application Publication No. 2002-327036, Japanese Patent Application Publication No. 2002-173410, Japanese Patent Application Publication No. 2004-307837, and Japanese Patent Application Publication No. 2006-38246 can also be used in this invention.

[0647] Furthermore, organic resin particles coated with silica can also be obtained from commercially available products. Specifically, examples of silica / melamine composite particles include OPTBEADS2000M, OPTBEADS 3500M, OPTBEADS 6500M, OPTBEADS 10500M, OPTBEADS 3500S, and OPTBEADS6500S manufactured by Nissan Chemical Industries, LTD. Examples of silica / acrylic composite particles include ART PEARL G-200 clear, ART PEARL G-400 clear, ART PEARL G-800 clear, ART PEARL GR-400 clear, ART PEARL GR-600 clear, ART PEARL GR-800 clear, and ART PEARL J-7P manufactured by Negami Chemical Industrial Co., LTD. Examples of silica / urethane composite particles include ART PEARL C-400 transparent, C-800 transparent, P-800T, U-600T, U-800T, CF-600T, and CF800T manufactured by Negami Chemical Industrial Co., Ltd., and Dynamic Beads CN5070D and Dumpla Coat THU manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.

[0648] The above description uses organic resin particles coated with silica as an example. However, organic resin particles coated with alumina, titanium dioxide, or zirconium dioxide can also be implemented in the same way by using alumina, titanium dioxide, or zirconium dioxide instead of silica.

[0649] The shape of the aforementioned particles is preferably spherical, but it can be flat or, as shown in the projection, elliptical, a so-called spindle shape.

[0650] 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.

[0651] The average particle size refers to the volume average particle size, which is measured using a laser diffraction / scattering particle size analyzer. Specifically, for example, it is measured using a particle size distribution measuring device such as the "Microtrac MT-3300II" (manufactured by Nikkiso Co., Ltd.).

[0652] Unless otherwise specified, the average particle size of other particles is also measured using the methods described above.

[0653] 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 .

[0654] 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 by observing five locations on the surface of the lithographic printing plate master using a scanning electron microscope (SEM), converting the number of particles per square millimeter of the observation field area, and then calculating the average value.

[0655] 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.

[0656] As an adhesive, it is preferred to contain at least one of the following: phenolic varnish resins 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), 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.

[0657] Furthermore, the adhesive described above preferably contains at least one selected from polyurethane, acrylic resin, polystyrene, and polyethylene.

[0658] Furthermore, in the above-described method 1, it is preferable that the particles and the adhesive each independently contain at least one selected from polyurethane, acrylic resin, polystyrene, and polyethylene.

[0659] In addition to the aforementioned particles and adhesive, the outermost layer on the side opposite to the side having the image recording layer may contain other components. Examples of such other components include known additives, such as surfactants.

[0660] 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.

[0661] The polymeric compound comprising multiple protrusions as a main component in Method 2 is preferably selected from at least one polymeric compound selected from phenolic varnish resins such as phenol-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.

[0662] From the viewpoint that the reproducibility remains excellent even when the detached protrusion moves to the image recording layer, water-soluble polymers are preferred. Specifically, examples include polyacrylates, carboxyethylene polymers, acrylic resin copolymers, hydroxycellulose, hydroxymethylcellulose, polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, cellulose acetate, methylcellulose, and carboxymethylcellulose.

[0663] 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.

[0664] 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.

[0665] 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 particles and polymeric compounds using at least one of the following methods: bar coating, inkjet printing, gravure printing, screen printing, spraying, and slot die coating.

[0666] There are no particular limitations on the method for forming dot-like protrusions (dot coating film), but they can be easily formed by coating a composition comprising at least one of particles and polymeric compounds by at least one of spraying, inkjet printing and screen printing methods.

[0667] There are no particular limitations on the method for forming dotted protrusions (dotted coating), but it can be easily formed by coating a composition comprising at least one of particles and polymeric compounds by at least one of inkjet printing and screen printing methods.

[0668] 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.

[0669] 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 the constituent units in the resin do not need to be the same.

[0670] [Methods for making printing plates]

[0671] 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 exposed lithographic printing plate original on a printing press by using at least one of printing ink and dampening solution (on-machine development step).

[0672] [Exposure process]

[0673] Image exposure is preferably performed by scanning and exposing digital data using methods such as infrared lasers.

[0674] 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.

[0675] 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.

[0676] [On-machine developing process]

[0677] In the on-machine developing process, if printing ink and dampening solution are supplied to the printing press to begin printing without any developing treatment of the original lithographic printing plate after image exposure, the unexposed portions of the original lithographic printing plate are removed in the early stages of printing, thereby exposing the surface of the hydrophilic support and forming non-image areas. Known lithographic printing inks and dampening solutions can be used as the printing ink and dampening solution. Either the printing ink or the dampening solution can be supplied first 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 supply the printing ink first.

[0678] In this way, the original lithographic printing plate is developed on the offset printing press and used directly in multiple printings.

[0679] In addition to the steps described above, the method for manufacturing 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.

[0680] Example

[0681] The present invention will now be described in detail through examples, but the invention is not limited thereto. In the examples, "%" and "parts" refer to "mass %" and "parts by mass," respectively, unless otherwise specified. In polymeric compounds, unless specifically specified, the molecular weight is the mass-average molecular weight (Mw), and the ratio of repeating structural units is the molar percentage. The mass-average molecular weight (Mw) is a value measured as a polystyrene conversion based on gel permeation chromatography (GPC).

[0682] [Examples 1 to 29 and Comparative Examples 1 to 2]

[0683] <Fabrication of Support 1>

[0684] The support body 1 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.

[0685] (Fa) Alkali etching treatment

[0686] Etching was performed by spraying an aqueous solution of caustic soda (26% by mass) and aluminum ions (6.5% by mass) at 70°C onto an aluminum plate using a sprayer. The aluminum dissolution rate on the surface after electrochemical roughening was then 5 g / m². 2 .

[0687] (Fb) used acidic aqueous solution for decontamination treatment.

[0688] An acidic aqueous solution with a temperature of 30°C and a sulfuric acid concentration of 150 g / L was sprayed onto the aluminum plate for 3 seconds using a sprayer and then used for decontamination treatment.

[0689] (Fc) Electrochemical roughening treatment

[0690] 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.

[0691] 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.

[0692] (Fd) alkaline etching treatment

[0693] Etching was performed by spraying an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) at 45°C onto an aluminum plate using a sprayer. The dissolved aluminum content on the surface after electrochemical roughening was 0.2 g / m². 2 .

[0694] (Fe) was treated with an acidic aqueous solution for decontamination.

[0695] An acidic aqueous solution with a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L was sprayed onto the aluminum plate for 3 seconds using a sprayer and then used for decontamination treatment.

[0696] (Ff) Stage 1 Anodizing Treatment

[0697] Using based Figure 6 The DC electrolytic anodizing apparatus shown underwent 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.

[0698] exist Figure 6 In the anodizing apparatus 410 shown, the aluminum plate 416 is as follows: 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 is charged (+) by 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 to the electrolytic treatment tank 414 containing electrolyte 426, and then horizontally by roller 428. Next, the aluminum plate 416 is charged (-) by 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 subsequent processes. 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.

[0699] (Fg) Stage 2 Anodizing Treatment

[0700] 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, and the conditions were: 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.

[0701] The value of lightness L* in the L*a*b* color system of the anodic oxide film surface of support 1 is 83.7.

[0702] <Construction of Support Body 2>

[0703] The support body 2 was manufactured by performing the following treatments (Fa) to (Ff) 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.

[0704] (Fa) Alkali etching treatment

[0705] Etching was performed by spraying an aqueous solution of caustic soda (26% by mass) and aluminum ions (6.5% by mass) at 70°C onto an aluminum plate using a sprayer. The aluminum dissolution rate on the surface after electrochemical roughening was then 5 g / m². 2 .

[0706] (Fb) used acidic aqueous solution for decontamination treatment.

[0707] An acidic aqueous solution with a temperature of 30°C and a sulfuric acid concentration of 150 g / L was sprayed onto the aluminum plate for 3 seconds using a sprayer and then used for decontamination treatment.

[0708] (Fc) Electrochemical roughening treatment

[0709] 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.

[0710] 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.

[0711] (Fd) alkaline etching treatment

[0712] Etching was performed by spraying an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) at 45°C onto an aluminum plate using a sprayer. The dissolved aluminum content on the surface after electrochemical roughening was 0.2 g / m². 2 .

[0713] (Fe) was treated with an acidic aqueous solution for decontamination.

[0714] An acidic aqueous solution with a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L was sprayed onto the aluminum plate for 3 seconds using a sprayer and then used for decontamination treatment.

[0715] (Ff) Stage 1 Anodizing Treatment

[0716] Using based Figure 6 The DC electrolytic anodizing apparatus shown underwent 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.

[0717] The average diameter of the micropores in support 2 is 40 nm.

[0718] The value of lightness L* in the L*a*b* color system of the anodic oxide film surface of support 2 is 82.4.

[0719] <Construction of Support Body 3>

[0720] The support 3 was manufactured in accordance with the manufacturing method of the support in Example 5 of International Publication No. 2021 / 67054.

[0721] <Construction of Support Body 4>

[0722] The support body 4 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.

[0723] (Ja) Mechanical roughening treatment (brush texture method)

[0724] Use such as Figure 5 The apparatus shown contains a suspension of pumice powder (specific gravity 1.1 g / cm³). 3 While being supplied to the surface of the aluminum plate as an abrasive slurry, it undergoes mechanical roughening treatment via a rotating 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.

[0725] 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.

[0726] (Jb) Alkali etching treatment

[0727] Etching was performed by spraying an aqueous solution of caustic soda (26% by mass) and aluminum ions (6.5% by mass) at 70°C onto an aluminum plate using a sprayer. The aluminum dissolution rate on the surface after electrochemical roughening was then 10 g / m². 2 .

[0728] (Jc) used acidic aqueous solution for decontamination treatment.

[0729] The waste liquid of 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 and was then treated to remove contaminants.

[0730] (Jd) used electrochemical roughening treatment with nitric acid aqueous solution.

[0731] 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 trapezoidal rectangular wave AC current 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 .

[0732] (Je) alkaline etching treatment

[0733] Etching was performed by spraying an aqueous solution of caustic soda (27% by mass) and aluminum ions (2.5% by mass) at 50°C onto an aluminum plate using a sprayer. The aluminum dissolution rate was 3.5 g / m². 2 .

[0734] (Jf) used acidic aqueous solution for decontamination treatment.

[0735] An acidic aqueous solution with a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L was sprayed onto the aluminum plate for 3 seconds using a sprayer and then used for decontamination treatment.

[0736] (Jg) underwent electrochemical roughening treatment using hydrochloric acid aqueous solution.

[0737] Electrochemical roughening 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 1The waveform shown, with a current value reaching its peak value from zero in 0.8 msec (tp), a duty ratio of 1:1, and a trapezoidal rectangular wave AC current, was used. The carbon electrode was electrochemically roughened as the counter electrode. Ferrite was used as the auxiliary anode. Regarding the electrolytic cell, [the following is a description of the process:] A trapezoidal rectangular wave AC current was used. Figure 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 .

[0738] (Jh) Alkali etching treatment

[0739] Etching was performed by spraying an aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) at 60°C onto an aluminum plate using a sprayer. The aluminum dissolution rate was 0.2 g / m². 2 .

[0740] (Ji) used acidic aqueous solution for decontamination treatment.

[0741] An aqueous solution of 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 as an acidic aqueous solution, and then treated to remove contaminants.

[0742] (Jj) Stage 1 Anodizing Treatment

[0743] 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.

[0744] (Jk) Hole Enlargement Treatment

[0745] The aluminum plate that had undergone anodizing was immersed in a caustic soda aqueous solution at 40°C with a concentration of 5% by mass of caustic soda and an aluminum ion concentration of 0.5% by mass for 3 seconds to perform a hole-expanding treatment.

[0746] (Jl) Stage 2 Anodizing Treatment

[0747] 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, and the conditions were: a liquid temperature of 50°C and a current density of 13 A / dm³. 2Anodizing was performed under specific conditions, resulting in a film thickness of 2.1 g / m³. 2 The anodic oxide film.

[0748] (Jm) hydrophilic treatment

[0749] 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.

[0750] The value of lightness L* in the L*a*b* color system of the anodic oxide film surface of the support 4 is 72.3.

[0751] <Construction of Support Body 5>

[0752] -Alkali etching treatment-

[0753] Etching was performed by spraying an aqueous solution of caustic soda (26% by mass) and aluminum ions (6.5% by mass) at 55°C onto an aluminum plate using a sprayer. This was followed by a spray-based water wash. The aluminum dissolution rate on the surface after electrochemical roughening was then 3 g / m². 2 .

[0754] - Decontamination treatment using acidic aqueous solution (first decontamination treatment) -

[0755] Next, a decontamination treatment was performed using an acidic aqueous solution. The acidic aqueous solution used was a 170 g / L sulfuric acid solution at a temperature of 30°C. The acidic aqueous solution was sprayed onto the aluminum plate using a sprayer and the decontamination was performed for 3 seconds. Then, a water rinse was performed.

[0756] -Electrochemical roughening treatment-

[0757] Next, electrochemical roughening treatment was performed using a hydrochloric acid electrolyte and alternating current. The electrolyte temperature was 40°C. The alternating current waveform was a symmetrical sine wave with positive and negative phases and a frequency of 50Hz. Furthermore, the total charge, calculated based on the charge participating in the anode reaction on the aluminum plate, was 300 C / dm³. 2 The process was carried out under specific conditions. A carbon electrode was used as the counter electrode in the aluminum plate. Then, a water washing process was performed.

[0758] -Alkali etching treatment-

[0759] An aqueous solution of caustic soda (5% by mass) and aluminum ions (0.5% by mass) at 35°C was sprayed onto an electrochemically roughened aluminum plate using a sprayer, with an etching rate of 0.1 g / m. 2The etching process was performed as follows. Then, a water washing process was carried out.

[0760] -Decontamination treatment using acidic aqueous solution-

[0761] Next, a decontamination treatment was performed using an acidic aqueous solution. The acidic aqueous solution used was a 170 g / L sulfuric acid solution at a temperature of 30°C. The acidic aqueous solution was sprayed onto the aluminum plate using a sprayer and the decontamination was performed for 3 seconds. Then, a water rinse was performed.

[0762] -Anodizing Treatment-

[0763] Under conditions of sulfuric acid concentration of 170 g / L and liquid temperature of 40 °C, using direct current, the anodic oxide film thickness is 3 g / m. 2 The support 5 was obtained by anodizing.

[0764] <Forming of base coating 1>

[0765] A primer coating 1 is formed by applying a primer coating liquid (1) with the following composition to a support with a dry coating amount of 0.03 g / m2.

[0766] (Base coat liquid (1))

[0767] • Aqueous solution of polyacrylic acid (40% by mass)

[0768] Jurymer AC-10S (manufactured by TOAGOSEI CO., LTD.)

[0769] 3.0 copies

[0770] Water 27.0 parts

[0771] <Forming of base coating 2>

[0772] A base coat 2 is formed by applying a base coat liquid (2) with the following composition to a support with a dry coating amount of 26 mg / m2.

[0773] (Base coat liquid (2))

[0774]

[0775] [Chemical Formula 19]

[0776]

[0777] The values ​​on the lower right side of the brackets of each constituent unit in the above-mentioned primer 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.

[0778] <Formation of image recording layers 1-19, 22>

[0779] Image recording layer coating solutions (image recording layer coating solutions (1) to (19) and (22)) with the following compositions were applied to a rod and dried at 110°C for 40 seconds to form image recording layers 1 to 19 and 22 with a dry weight of 0.9 g / m2, respectively.

[0780] (Image recording layer coating solution)

[0781]

[0782] *1: Polymer emulsion A consists of polymer particles of a graft copolymer of poly(ethylene glycol) methyl ether methacrylate / styrene / acrylonitrile = 10:9:81, and is a dispersion containing 24% by mass of these particles in a solvent with a mass ratio of n-propanol / water of 80 / 20. Furthermore, its volume average particle size is 193 nm.

[0783] *2: Klucel E refers to hydroxypropyl cellulose that is available from Hercules.

[0784] *3: The compounds represented by Formula 1 below

[0785] *4: The compound represented by Formula 2 below

[0786] [Chemical Formula 20]

[0787]

[0788] *5: A xylene / methoxypropyl acetate solution containing modified polydimethylsiloxane copolymer at a concentration of 25% by mass (manufactured by BYK Chemie).

[0789] *6: Cross-linked acrylic beads, average particle size 5.0 μm (Sekisui Plastics Co., Ltd.)

[0790] [Table 1]

[0791]

[0792] Infrared absorber

[0793] The infrared absorbers listed in Table 1 will be described below.

[0794] [Chemical Formula 21]

[0795]

[0796] [Chromosome precursor]

[0797] The chromophore precursors listed in Table 1 will be described below.

[0798] [Chemical Formula 22]

[0799]

[0800] [Polymerizing compounds]

[0801] The following will describe the polymeric compounds listed in Table 1.

[0802] M-1:

[0803] 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.

[0804] (Weight-average molecular weight: 1650)

[0805] M-2:

[0806] 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 KASEI CO., 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 mass 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.

[0807] M-3:

[0808] Dipentaerythritol pentaacrylate "Sartmer SR399" (manufactured by Sartmer Company)

[0809] M-4:

[0810] Ethoxylated (4) pentaerythritol tetraacrylate "Sartmer SR494" (manufactured by Sartmer Company)

[0811] M-5:

[0812] NK Ester A-9300 40% Methyl Ethyl Ketone Solution manufactured by Shin-Nakamura Chemical Co., Ltd.

[0813] [UV absorber]

[0814] The ultraviolet absorbers listed in Table 1 will be described below.

[0815] Tinuvin384 (manufactured by BASF Japan Ltd.)

[0816] Tinuvin928 (manufactured by BASF Japan Ltd.)

[0817] Tinuvin400 (manufactured by BASF Japan Ltd.)

[0818] Tinuvin405 (manufactured by BASF Japan Ltd.)

[0819] Tinuvin460 (manufactured by BASF Japan Ltd.)

[0820] Tinuvin479 (manufactured by BASF Japan Ltd.)

[0821] Uvinul3035 (manufactured by BASF Japan Ltd.)

[0822] Uvinul3039 (manufactured by BASF Japan Ltd.)

[0823] Uvinul3030 (manufactured by BASF Japan Ltd.)

[0824] Uvinul3049 (manufactured by BASF Japan Ltd.)

[0825] Uvinul3050 (manufactured by BASF Japan Ltd.)

[0826] In addition, the ultraviolet absorbers mentioned above are all compounds that have λmax at wavelengths of 280–400 nm.

[0827] <Formation of Image Recording Layer 20>

[0828] The image recording layer coating liquid (20) with the following composition was applied by a rod and dried at 110°C for 40 seconds to form an image recording layer 20 with a dry weight of 0.9 g / m2.

[0829] (Image recording layer coating solution (20))

[0830]

[0831] [Chemical Formula 23]

[0832]

[0833] [Chemical Formula 24]

[0834]

[0835] (Microgel solution)

[0836] The following shows the preparation method of the microgel used in the above microgel solution.

[0837] -Preparation of polyisocyanate compounds-

[0838] A suspension of 17.78 parts (80 molar equivalents) of isophorone diisocyanate and 7.35 parts (20 molar equivalents) of the following polyphenol compound (1) in ethyl acetate (25.31 parts) was stirred with 0.043 parts of tris(2-ethylhexanoate) bismuth (NEOSTANN U-600, manufactured by NITTO KASEI CO., LTD.). The reaction temperature was set to 50°C at the moment when exothermic reaction was stopped, and the mixture was stirred for 3 hours to obtain an ethyl acetate solution (50% by mass) of polyisocyanate compound (1).

[0839] [Chemical Formula 25]

[0840]

[0841] -Preparation of microgels-

[0842] 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% by weight 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 solid components was adjusted to 20% by weight with distilled water to obtain an aqueous dispersion of microgel (1). The average particle size, measured by light scattering, was 0.28 μm.

[0843] ~Oil phase ingredients~

[0844] (Component 1) Ethyl acetate: 12.0 parts

[0845] (Component 2) An adduct (50% by mass ethyl acetate solution, manufactured by Mitsui Chemicals, Inc.) formed by adding trimethylolpropane (6 molar equivalents) and xylene diisocyanate (18 molar equivalents) to it, followed by the addition of mono-terminated methylated polyoxyethylene (1 molar equivalent, number of repeats of oxyethylidene units: 90).

[0846] (Component 3) Polyisocyanate compound (1) (as a 50% by mass ethyl acetate solution): 15.0 parts

[0847] (Component 4) 11.54 parts of 65% by weight ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartamer Company, Inc.)

[0848] (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).

[0849] ~Aqueous phase components~

[0850] Distilled water: 46.87 parts

[0851] <Formation of Image Recording Layer 21>

[0852] The image recording layer coating solution (21) with the following composition was applied to the rod and dried at 120°C for 40 seconds to form a dried weight of 1.0 g / m². 2 Image recording layer 21.

[0853] The image recording layer coating solution (21) contains the components described below and is prepared in a manner with a solid content of 6% by mass using a mixed solvent of 1-methoxy-2-propanol (MFG): methyl ethyl ketone (MEK): methanol = 4:4:1 (mass ratio).

[0854]

[0855] P-2: Polyvinyl acetal, S-LEC BL10 manufactured by SEKISUI CHEMICAL CO.,LTD.

[0856] [Chemical Formula 26]

[0857]

[0858] Image recording layers 1-22 are uniformly dispersed in water at 20°C. Image recording layers 1-22 are water-dispersible.

[0859] <Formation of protective layers 1-7>

[0860] After applying the protective coating liquids (protective coating liquids (1) to (7)) with the following compositions to the image recording layer by bar coating, the protective layer with a dry coating amount of 0.1 g / m2 is formed by drying at 120°C for 60 seconds.

[0861] (Protective coating liquid)

[0862]

[0863] [Table 2]

[0864]

[0865] [UV absorber]

[0866] The ultraviolet absorbers listed in Table 2 will be described below.

[0867] UVA-805 (manufactured by BASF Japan Ltd.)

[0868] Tinuvin9945-DW(N) (Manufactured by BASF Japan Ltd.)

[0869] Tinuvin400-DW(N) (Manufactured by BASF Japan Ltd.)

[0870] Tinuvin477-DW(N) (Manufactured by BASF Japan Ltd.)

[0871] Tinuvin479-DW(N) (Manufactured by BASF Japan Ltd.)

[0872] Tinuvin123-DW(N) (Manufactured by BASF Japan Ltd.)

[0873] Tinuvin 5333-DW(N) (Manufactured by BASF Japan Ltd.)

[0874] In addition, the ultraviolet absorbers mentioned above are all compounds that have λmax at wavelengths of 280–400 nm.

[0875] <Formation of Protective Layer 8>

[0876] After applying a protective coating solution (8) with the following composition to the image recording layer, it is dried at 120°C for 60 seconds to form a dry coating with a coating weight of 0.15 g / m².2 8. Protective layer.

[0877] (Protective coating liquid (8))

[0878]

[0879]

[0880] [Chemical Formula 27]

[0881]

[0882] C 12 H 25 -(OCHCH2)10-OH

[0883] EMALEX710

[0884] (Preparation of Inorganic Layered Compound Dispersion (1))

[0885] 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.

[0886] <Formation of Protective Layer 9>

[0887] A protective coating liquid (9) with the following composition was applied to a rod and dried at 120°C for 60 seconds to form a dry coating weight of 0.15 g / m². 2 9. Protective layer.

[0888] The protective coating liquid (9) contains the components described below and is prepared with ion-exchanged water in a manner where the solid content is 6% by mass.

[0889]

[0890] WP-1: Polyvinyl alcohol, Mowiol 4-88 manufactured by Sigma-Aldrich Co. LLC.

[0891] WP-2: Polyvinyl alcohol, Mowiol 8-88 manufactured by Sigma-Aldrich Co. LLC.

[0892] WP-3: The following resin (Mw52,000)

[0893] Surfactant: Anionic surfactant, RAPISOL A-80, manufactured by NOF CORPORATION

[0894] [Chemical Formula 28]

[0895]

[0896] <Formation of Protective Layer 10>

[0897] After applying a protective coating solution (10) with the following composition to the image recording layer by bar coating, it is dried at 120°C for 60 seconds to form a dry coating with a coating weight of 0.1 g / m. 2 10. Protective layer.

[0898] (Protective coating liquid (10))

[0899]

[0900] [Production of the original lithographic printing plate]

[0901] As described in Table 3, the above-described support, base coating, image recording layer, and protective layer were combined to produce the original offset printing plates of Examples 1-29 and Comparative Examples 1-2.

[0902] The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When exposing each image recording layer, the rate of disappearance of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is recorded in Table 3 as "Occurrence rate of olefinic unsaturated bonds during infrared laser exposure". The measurement method is shown below.

[0903] <Disappearance rate of olefinic unsaturated bonds during infrared laser exposure>

[0904] Using the LuxelPLATESETTER T-6000II I manufactured by Fujifilm Corporation and equipped with an 830nm infrared semiconductor laser, the obtained lithographic printing plate was processed at 120mJ / cm². 2 The exposure was performed using a specific method, resulting in an exposed image that includes both solid and non-image areas.

[0905] Next, using a HORIBA, Ltd. Fourier transform infrared spectrophotometer (FT-IR) "FT-720", the 1410 cm⁻¹ value originating from the olefinic unsaturated group was determined for the solid image portion and the non-image portion. -1 Near the peak area. At this time, the support of each lithographic printing plate is used as the background. The peak area of ​​the solid image part is set as S1, and the peak area of ​​the non-image part is set as S2. The disappearance rate of olefinic unsaturated bonds R1 [%) is calculated by the following formula (1).

[0906] R1=[1-(S1 / S2)]×100····(1)

[0907] When each image recording layer was exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the rate of disappearance of olefinic unsaturated bonds in the exposed area relative to the unexposed area is recorded in Table 3 as "Occurrence rate of olefinic unsaturated bonds during white lamp exposure". The measurement method is shown below.

[0908] <Disappearance rate of olefinic unsaturated bonds during white light exposure>

[0909] The original lithographic printing plate was exposed to a white fluorescent lamp to achieve an illuminance of 600 Lux on the printing plate. After one hour of exposure, the 1410 cm⁻¹ values ​​of the exposed and unexposed areas derived from the olefinic unsaturated groups were determined using a HORIBA, Ltd. Fourier transform infrared spectrophotometer (FT-IR) "FT-720". -1 Near the peak area. At this time, the support of each lithographic printing plate is used as the background. The peak area of ​​the exposed part is set as S3, and the peak area of ​​the unexposed part is set as S4. The disappearance rate of olefinic unsaturated bonds R2 [%) is calculated by the following formula (2).

[0910] R2=[1-(S3 / S4)]×100····(2)

[0911] In Table 3, the hydrogen abstraction enthalpy of all hydrogen atoms present in the chromophore precursor molecule is recorded as "hydrogen abstraction enthalpy of chromophore precursor".

[0912] The hydrogen abstraction enthalpy of all hydrogen atoms present in the chromophore precursor molecule was calculated using the method described above.

[0913] [Table 3]

[0914]

[0915] <Brush Resistance Evaluation>

[0916] Using the LuxelPLATESETTER T-6000III manufactured by Fujifilm Corporation, equipped with an 830nm infrared semiconductor laser, the obtained lithographic printing plate was processed at 120mJ / cm². 2 The exposure was performed using a specific exposure method. This resulted in an exposed image containing a solid image, a 50% halftone dot map (AM screen), and non-image areas.

[0917] The lithograph master plate, which had been exposed to the image, was installed on an offset rotary printing press manufactured by TOKYO KIKAI SEISAKUSHO, LTD. SOYBI KKST-S (red) manufactured by INKTEC CO., LTD. was used as the printing ink for newspapers and magazines, and TOYO ALKY manufactured by TOYO INK CO., LTD. was used as the dampening solution. 150,000 sheets of newspapers and magazines were printed at a speed of 100,000 sheets / hour.

[0918] As the number of printed sheets increases, the image recording layer gradually wears down and ink receptivity decreases, resulting in a decrease in ink concentration in the printing paper. This was confirmed visually.

[0919] 5: There is almost no change compared to when there were 10,000 images.

[0920] 4: Compared to 10,000 images, approximately 70% of the images remain.

[0921] 3: Compared to 10,000 images, approximately 50% of the images remain.

[0922] 2: Compared to 10,000 images, approximately 20% of the images remain.

[0923] 1: Almost no ink residue

[0924] <Colorimetric Evaluation (Visual Recognition)>

[0925] Using the LuxelPLATESETTER T-6000 III manufactured by Fujifilm Corporation, equipped with an 830nm infrared semiconductor laser, the obtained lithographic printing plate was processed at 120mJ / cm². 2 Exposure was performed using a specific exposure method. This resulted in an exposed image containing both solid and non-image areas. Exposure was conducted at 25°C and 50% RH.

[0926] The color rendering of the original offset printing plate immediately after exposure was measured. Measurements were performed using a Konica Minolta, Inc. CM2600d spectrophotometer and CM-S100W software, via SCE (Selective Color Envelope Correction). Color rendering properties were evaluated using the L* values ​​(lightness) of the L*a*b* color system, based on the difference ΔL between the L* values ​​of the exposed and unexposed areas. A larger ΔL value indicates better color rendering.

[0927] Suppression of Development Delay

[0928] Regarding the suppression of development delay, the safety under white fluorescent lamps was evaluated as follows (white lamp safety).

[0929] Using the LuxelPLATESETTER T-6000III manufactured by Fujifilm Corporation, equipped with an 830nm infrared semiconductor laser, the obtained lithographic printing plate was processed at 120mJ / cm². 2 Exposure was performed using a specific exposure method. The exposed image included a solid image, a 50% halftone image (AM), and non-image areas. Then, a lithographic printing plate, exposed for 3 hours under a white fluorescent lamp at an illuminance of 600 Lux on the printing surface, was mounted on an offset rotary printing press manufactured by TOKYOKIKAI SEISAKUSHO, LTD. SOYBI KKST-S (red) manufactured by INKTEC CO., LTD. was used as the ink for newspaper printing, and TOYOALKY manufactured by TOYO INK CO., LTD. was used as the dampening solution. On-machine development was performed on newspaper paper at a rate of 100,000 sheets / hour. The number of sheets developed on-machine for both the 50% halftone and non-image areas was counted.

[0930] When the number of developed sheets of the original lithographic printing plate that underwent 3 hours of white light exposure after exposure was set as N1, and the number of developed sheets of the original lithographic printing plate that underwent no white light exposure after exposure was set as N2, the evaluation was carried out with N1-N2=ΔN and according to the following criteria.

[0931] 5: ΔN = 0

[0932] 4: 1≤ΔN≤10

[0933] 3: 11≤ΔN≤20

[0934] 2: 21≤ΔN≤30

[0935] 1:31≤ΔN

[0936] Based on the results recorded in Table 3, the on-machine developable lithographic printing plate original according to the present invention has good color development and can suppress development delay.

[0937] Furthermore, it is known that the machine-developable lithographic printing plate original according to the present invention has good color development and can suppress development delay, and also has excellent brush resistance.

[0938] <Cut the original offset printing plate>

[0939] The original lithographic printing plates of Examples 30-33 were produced in the same manner as the original lithographic printing plate of Example 9. The original lithographic printing plates of Examples 9 and 30-33 are identical.

[0940] For the original offset printing plates of Examples 9, 30-33, the following method was used: Figure 4 The rotating blade shown adjusts the gap, engagement amount, and blade tip angle between the upper and lower cutting blades to perform cutting, resulting in a collapsed edge shape at the end.

[0941] The collapse amount X and collapse width Y in the collapse shape are recorded in Table 4.

[0942] <Formation of Edge Layer 1>

[0943] An edge layer 1 is formed by coating composition 1 under the following coating conditions 1.

[0944] (Coating Condition 1)

[0945] pass Figure 7 The coating method shown was used for coating. Regarding the printing bar, the bar was positioned perpendicular to the original lithographic printing plate (θ = 0°) and coating was performed. Coating was carried out through the following steps.

[0946] [1] 1 cm of solution was evenly added to the 10th bar. 3 The HN-GV (manufactured by FUJIFILM Global GraphicSystems Co., Ltd.)

[0947] [2] The bar is moved at 20 mm / s along the side of the lithographic printing plate. At this time, the bar is set perpendicular to the lithographic printing plate (θ = 0°).

[0948] [3] The product was dried by blowing air at 80°C and 6 m / s for 30 seconds.

[0949] [4] It can coat only the sides of the original lithographic printing plate. In this case, the coating amount of composition 1 is 120 mg / m². 2 .

[0950] [5] The deviation Z of the coating width from the end of the original lithographic printing plate is Z = 0.1 mm.

[0951] Composition 1 contains the following ingredients.

[0952]

[0953] *1: Etherified starch (Nippon Starch Chemical Co., Ltd.)

[0954] *2: Cocamidopropyl betaine (NOF Corporat ion)

[0955] *3: Disinfectant or bactericide (Daiwa Chemical Industries Corporation)

[0956] The aforementioned deviation Z is calculated based on

[0186] to

[0187] of Japanese Patent No. 6628949.

[0957] As shown in Table 4, a lithographic printing plate original with a collapsed edge shape at the end and an edge layer were combined to create a lithographic printing plate original for measuring edge contamination prevention performance.

[0958] The edge contamination prevention performance was evaluated in the following manner.

[0959] <Edge contamination prevention performance>

[0960] The original lithographic printing plate was exposed using a Luxcel PLATESETTERT-6000III manufactured by Fujifilm Corporation, equipped with an infrared semiconductor laser, at an outer drum speed of 1,000 rpm, laser output of 70%, and a resolution of 2,400 dpi. The exposed images included solid images, 50% halftone dots, and non-image areas.

[0961] An offset printing plate master with image exposure was mounted on an offset rotary printing press manufactured by TOKYO KIKAI SEISAKUSHO, LTD. SOYBI KKST-S (red) manufactured by INKTEC CO., LTD. was used as the ink for newspaper printing, and TOYO ALKY manufactured by TOYO INK CO., LTD. was used as the dampening solution. Newspapers were printed at a rate of 100,000 sheets / hour. The water level was reduced to 1.1 times the original water level to eliminate smudges. Samples were taken from the 1,000th print, and the degree of linear contamination caused by the edges of the offset printing plate master was evaluated according to the following criteria. The results are recorded in Table 4 as edge contamination prevention performance.

[0962] 5: Completely uncontaminated

[0963] 4: The intermediate level between 5 and 3

[0964] 3: Although slightly contaminated, it is within the permissible level.

[0965] 2: The intermediate level between 3 and 1 (permissible level)

[0966] 1: Clearly contaminated and below permissible levels

[0967] [Table 4]

[0968] 9 1 1 3 none 15 50 none 2 30 1 1 3 none 55 130 none 3 31 1 1 3 none 55 130 1 5 32 1 1 3 none 30 100 1 4 33 1 1 3 none 70 150 1 5

[0969] It can be seen that by using a lithographic printing plate with a specified collapsed edge shape, the edge contamination is excellent.

[0970] Industrial availability

[0971] According to the present invention, it is possible to provide an in-machine developable lithographic printing plate master with good color development and suppressing development delay, and a method for manufacturing a printing plate using the in-machine developable lithographic printing plate master.

[0972] Furthermore, according to the present invention, it is possible to provide an in-machine developable lithographic printing plate master with good color development, suppressing development delay and excellent brush resistance, and a method for manufacturing a printing plate using the in-machine developable lithographic printing plate master.

[0973] 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.

[0974] This application claims are based on Japanese patent application filed on August 31, 2021 (Japanese Patent Application 2021-142007), the contents of which are incorporated herein by reference.

[0975] Symbol Explanation

[0976] 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-Slump amount, Y-Slump width, 100a-Original plate for lithographic printing, 120-End face, 122-Outermost surface of image recording layer side based on support, 138-Wire rod, θ-Angle.

Claims

1. An on-machine developing type lithographic printing plate master, which sequentially comprises a support, an image recording layer, and a protective layer. The image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor. The polymerizable compound has four or more functional groups, each of which is a group that facilitates polymerization and is an olefinically unsaturated bond. The protective layer comprises an ultraviolet absorber and a water-soluble polymer or a water-insoluble polymer. The ultraviolet absorber has a maximum absorption wavelength λmax in the wavelength region of 280–400 nm. The maximum absorption wavelength is measured by the following method: A 0.1% by mass solution was prepared by dissolving the ultraviolet absorber in a good solvent. The prepared solution was used to measure the ultraviolet-visible absorption spectrum using a Hitachi High-Tech Science Corporation U-3010 spectrophotometer. The wavelength representing the maximum absorbance was taken as the maximum absorption wavelength.

2. An on-machine developing type lithographic printing plate master, which sequentially comprises a support body and an image recording layer. The image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, d) a chromophore precursor, and e) an ultraviolet absorber. The polymerizable compound has four or more functional groups and a molecular weight of less than 15,000. Each functional group is a polymerization-promoting group and is an olefinically unsaturated bond. The ultraviolet absorber has a maximum absorption wavelength λmax in the wavelength region of 280–400 nm. The maximum absorption wavelength is measured by the following method: A 0.1% by mass solution was prepared by dissolving the ultraviolet absorber in a good solvent. The prepared solution was used to measure the ultraviolet-visible absorption spectrum using a Hitachi High-Tech Science Corporation U-3010 spectrophotometer. The wavelength representing the maximum absorbance was taken as the maximum absorption wavelength.

3. An on-machine developing type lithographic printing plate master, which sequentially comprises a support, an image recording layer, and a protective layer. The image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, and d) a chromophore precursor. The polymerizable compound has four or more functional groups, each of which is a polymerization-promoting group and is an olefinically unsaturated bond. The protective layer comprises an ultraviolet absorber and a water-soluble or water-insoluble polymer. The ultraviolet absorber has a maximum absorption wavelength λmax in the wavelength region of 280–400 nm. The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is 10% or more. When the image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%. The maximum absorption wavelength is measured by the following method: A 0.1% by mass solution was prepared by dissolving the ultraviolet absorber in a good solvent. The prepared solution was used to measure the ultraviolet-visible absorption spectrum using a Hitachi High-Tech Science Corporation U-3010 spectrophotometer. The wavelength representing the maximum absorbance was taken as the maximum absorption wavelength.

4. An on-machine developing type lithographic printing plate master, which sequentially comprises a support body and an image recording layer. The image recording layer comprises a) a polymerizable compound, b) an infrared absorber, c) a polymerization initiator, d) a chromophore precursor, and e) an ultraviolet absorber. The polymerizable compound has four or more functional groups, each of which is a polymerization-promoting group and is an olefinically unsaturated bond. The ultraviolet absorber has a maximum absorption wavelength λmax in the wavelength region of 280–400 nm. The energy density of infrared laser exposure at a wavelength of 830 nm is 120 mJ / cm². 2 When the image recording layer is exposed, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region in the image recording layer is 10% or more. When the image recording layer is exposed to a white fluorescent lamp with an illuminance of 600 Lux for 1 hour, the disappearance rate of olefinic unsaturated bonds in the exposed region relative to the unexposed region is less than 10%. The maximum absorption wavelength is measured by the following method: A 0.1% by mass solution was prepared by dissolving the ultraviolet absorber in a good solvent. The prepared solution was used to measure the ultraviolet-visible absorption spectrum using a Hitachi High-Tech Science Corporation U-3010 spectrophotometer. The wavelength representing the maximum absorbance was taken as the maximum absorption wavelength.

5. The on-machine developing type lithographic printing plate original according to any one of claims 1 to 4, wherein, The image recording layer contains a polymeric compound with seven or more functions and a molecular weight of less than 15,000 as the polymeric compound.

6. The on-machine developing type lithographic printing plate original according to any one of claims 1 to 4, wherein, The image recording layer contains a polymeric compound with more than 10 functions and a molecular weight of less than 15,000 as the polymeric compound.

7. The on-machine developing type lithographic printing plate original according to any one of claims 1 to 4, wherein, The image recording layer contains polymer particles.

8. The on-machine developing type lithographic printing plate original according to claim 7, wherein, The polymer particles have a hydrophobic backbone and contain the following two types of building blocks: i) A constituent unit having a cyano side group directly bonded to the hydrophobic main chain; and ii) Constituents having side groups containing hydrophilic poly(epoxy) segments.

9. The on-machine developing type lithographic printing plate original according to claim 7, wherein, The polymer particles are obtained by reacting a polyisocyanate compound with a compound containing active hydrogen, wherein the polyisocyanate compound is an adduct of a polyphenolic compound having two or more hydroxyl groups in its molecule with isophorone diisocyanate.

10. The on-machine developable lithographic printing plate original according to any one of claims 1 to 4, wherein, All hydrogen abstraction enthalpies present within the molecule of the chromophore precursor are greater than -6.5 kcal / mol.

11. The on-machine developing type lithographic printing plate original according to any one of claims 1 to 4, wherein, The chromophore precursor has a tertiary amine structure.

12. The on-machine developing type lithographic printing plate original according to any one of claims 1 to 4, wherein, The chromophore precursor contains an acidic chromophore agent.

13. The on-machine developing type lithographic printing plate original according to any one of claims 1 to 4, wherein, The support has an anodized film. 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.

14. The on-machine developing type lithographic printing plate original according to any one of claims 1 to 4, wherein, The support has an anodized film. 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 diameter of the large-diameter pores is less than 40 nm to 300 nm.

15. The on-machine developable lithographic printing plate original according to any one of claims 1 to 4, wherein, The support has an anodized film. The anodic oxide film has the following characteristics from its surface to its depth: The upper layer, with a thickness of 30nm to 500nm, has micropores with an average diameter of 20nm to 100nm; An intermediate layer with a thickness of 100 nm to 300 nm has micropores with an average diameter of 1 / 2 to 5 times the average diameter of the micropores in the upper micropore layer; and The lower layer, with a thickness of 300nm to 2000nm, has micropores with an average diameter of less than 15nm.

16. The on-machine developable lithographic printing plate original according to any one of claims 1 to 4, wherein, The end of the original lithographic printing plate has a collapsed edge shape with a collapsed edge amount X of 25μm to 150μm and a collapsed edge width Y of 70μm to 300μm.

17. The on-machine developing type lithographic printing plate original according to claim 16, wherein, The two opposing sides of the original lithographic printing plate have an ink-repellent agent on some or all of them.

18. 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 4; and The process of removing the unexposed portion of the image recording layer in a machine-developable lithographic printing plate original by supplying at least one of printing ink and dampening solution to the printing press.

Images