Support for lithographic printing plates, original lithographic printing plate, and manufacturing method of lithographic printing plates.

Abstract

The present invention provides a lithographic printing plate support with which a lithographic printing plate having excellent scratch resistance can be obtained by combining with an image recording layer, a lithographic printing plate, and a method for producing a lithographic printing plate. This lithographic printing plate support comprises an aluminum plate and an aluminum anodized film disposed on the aluminum plate. The surface of the lithographic printing plate support on the anodized film side has a plurality of protrusions, the average value of an equivalent circular diameter of a cut surface of a protrusion at a position 0.5 μm higher than the position of the average height of the protrusions is 3.0−10.0 μm, and the density of protrusions having a height of 0.5 μm or more above the position of the average height of the protrusions is 3000−9000 per square millimeter.

Description

[Technical Field]

[0001] The present invention relates to a support for a lithographic printing plate, a lithographic printing plate master, and a method for manufacturing a lithographic printing plate. [Background technology]

[0002] It is known that aluminum supports used in lithographic printing plates are given an uneven surface by sandblasting (roughening treatment) to improve stain resistance and print resistance when used as a lithographic printing plate. For example, Patent Document 1 describes a lithographic printing plate having an aluminum support and an image recording layer disposed on the aluminum support, wherein the aluminum support includes an aluminum plate and an anodic oxide film of aluminum disposed on the aluminum plate, and the image recording layer is disposed on the anodic oxide film side of the aluminum support, and the density of recesses with a depth of 0.70 μm or more from the center line, obtained by measuring a 400 μm × 400 μm area of ​​the surface on the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter, is 3000 recesses / mm². 2 The text states, "The above is the original plate for lithographic printing." [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2019 / 087516 [Overview of the project] [Problems that the invention aims to solve]

[0004] Recently, there has been a growing demand for even greater scratch resistance in lithographic printing plates, including the support materials used for them. The inventors of the present invention investigated a lithographic printing plate master plate including a support for lithographic printing plates described in Patent Document 1 and found that although its scratch resistance met the conventionally lenient requirements, it did not meet the currently required characteristics, and further improvements were necessary.

[0005] The present invention aims to provide a support for lithographic printing plates that, when combined with an image recording layer, can produce a lithographic printing plate master with excellent scratch resistance. Furthermore, the present invention aims to provide a lithographic printing plate master and a method for manufacturing a lithographic printing plate. [Means for solving the problem]

[0006] The inventors have found that the above problems can be solved by the following configuration.

[0007] (1) A support for a lithographic printing plate, comprising an aluminum plate and an anodized aluminum film disposed on the aluminum plate, The surface of the anodic oxide coating on the support for lithographic printing plates has multiple protrusions. The average equivalent circle diameter of the cross-section of the convexity at a position 0.5 μm higher than the average height of the convexity is 3.0 to 10.0 μm. The density of protrusions with a height of 0.5 μm or more above the average height of the protrusions is 3000 to 9000 per mm². 2 A support for lithographic printing plates. (2) A support for a lithographic printing plate as described in (1), wherein the average value of the equivalent circle diameter is 3.0 to 6.5 μm. (3) Density of 4000-9000 particles / mm 2 A support for a lithographic printing plate as described in (1) or (2). (4) The ratio of density to the average value of the equivalent circle diameter is 500 (particles / mm²) 2 A support for a lithographic printing plate as described in any of (1) to (3), having a thickness of ) / μm or more. (5) Anodized coating amount is 2.0 g / m² 2 The above is a support for a lithographic printing plate as described in any of (1) to (4). (6) Anodized coating amount is 3.2 g / m² 2 The above is a support for a lithographic printing plate as described in any of (1) to (5). (7) A support for a lithographic printing plate according to any of (1) to (6), wherein the surface area ratio ΔS calculated by formula (1) below from the actual area Sx obtained by the approximate three-point method from three-dimensional data obtained by measuring a 25 μm × 25 μm area of ​​the surface on the anodic oxide film side at 512 × 512 points using an atomic force microscope, and the geometrically measured area S0, is 20% or more. ΔS=(Sx-S0) / S0×100(%) (1) (8) The anodic oxide film has micropores, The micropore consists of a large-diameter pore extending from the surface of the anodic oxide film to a depth of 10 to 1000 nm, and a small-diameter pore communicating with the bottom of the large-diameter pore and extending from the communication point to a depth of 20 to 2000 nm. The average diameter of the large-diameter pores on the surface of the anodic oxide film is 18-60 nm. A support for a lithographic printing plate according to any one of (1) to (7), wherein the average diameter at the communication position of the small-diameter holes is 15 nm or less. (9) The anodic oxide film has micropores, A micropore consists of an upper pore extending in the depth direction from the surface of the anodic oxide film, and a lower pore that communicates with the bottom of the upper pore and extends from the communication point to a depth of 20 to 2000 nm. The average diameter of the upper pores on the surface of the anodic oxide film is 18-60 nm. The maximum diameter of the upper pore is 200 nm or less. The average diameter at the communication point of the lower hole is 15 nm or less. A support for a lithographic printing plate according to any one of (1) to (7), wherein the ratio of the maximum diameter of the upper pores to the average diameter of the upper pores on the surface of the anodic oxide film is 1.2 or more. (10) Micropore density is 300-2000 particles / μm 2 A support for a lithographic printing plate as described in (8) or (9). (11) A lithographic printing plate master comprising a support for a lithographic printing plate as described in any of (1) to (10) and an image recording layer. (12) A lithographic printing plate as described in (11), which is developed on-board. (13) A step of exposing the lithographic printing plate described in (11) to an image using an infrared laser, A method for manufacturing a lithographic printing plate, comprising the step of removing unexposed portions of an image recording layer on a printing press using at least one selected from printing ink and dampening solution. [Effects of the Invention]

[0008] According to the present invention, a support for a lithographic printing plate can be provided that, when combined with an image recording layer, can be used to obtain a lithographic printing plate master with excellent scratch resistance. Furthermore, according to the present invention, a lithographic printing plate master and a method for manufacturing a lithographic printing plate can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional view of one embodiment of a support for a lithographic printing plate according to the present invention. [Figure 2] This figure illustrates the morphology of the anodic oxide coating on the support for lithographic printing plates of the present invention. [Figure 3] This diagram illustrates the equivalent circle diameter of the cross-section of the convex portion. [Figure 4] This is a schematic cross-sectional view of one embodiment of an anodized coating. [Figure 5] This is a schematic cross-sectional view of one embodiment of an anodized coating. [Figure 6] This graph shows an example of an alternating waveform current waveform diagram used in the electrochemical roughening treatment in the manufacturing method of a support for lithographic printing plates. [Figure 7] This is a side view showing an example of a radial cell used in an electrochemical roughening treatment using alternating current in a manufacturing method for a support for a lithographic printing plate. [Figure 8] This is a schematic cross-sectional view of one embodiment of a master plate for lithographic printing. [Figure 9] This is a schematic diagram of an anodizing apparatus used for anodizing in the production of supports for lithographic printing plates. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively. Furthermore, in this specification, when a group in a compound represented by a formula is not specified as substituted or unsubstituted, if the group can have further substituents, then unless otherwise specified, the group includes not only unsubstituted groups but also substituted groups. For example, if a formula states that "R represents an alkyl group, an aryl group, or a heterocyclic group," then it means that "R represents an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aryl group, a substituted aryl group, an unsubstituted heterocyclic group, or a substituted heterocyclic group."

[0011] The present invention provides a support for a lithographic printing plate, comprising an aluminum plate and an anodic oxide film of aluminum disposed on the aluminum plate, wherein the surface of the anodic oxide film side of the support for the lithographic printing plate has a plurality of protrusions, the average equivalent circle diameter of the cross-section of the protrusions at a position 0.5 μm higher than the average height of the protrusions is 3.0 to 10.0 μm, and the density of protrusions having a height of 0.5 μm or more above the average height of the protrusions is 3000 to 9000 protrusions / mm². 2 That is the case. The present invention's support for lithographic printing plates will be described in detail below with reference to the drawings.

[0012] Figure 1 is a schematic cross-sectional view of one embodiment of a support for a lithographic printing plate according to the present invention. The lithographic printing plate support 10 shown in Figure 1 has a laminated structure in which an aluminum plate 12 and an aluminum anodic oxide film 14A (hereinafter also simply referred to as the anodic oxide film) are laminated in this order. Figure 2 is an enlarged view of the surface 141A of the anodic oxide film 14A opposite to the aluminum plate 12 side in Figure 1 (in other words, the surface of the lithographic printing plate support on the anodic oxide film side), and the surface 141A of the anodic oxide film 14A has a plurality of protrusions (in Figure 2, the first protrusion 16A, the second protrusion 16B, and the third protrusion 16C). Although only three protrusions are shown in Figure 2, the embodiments of the present invention are not limited to this figure. Below, we will first describe the characteristic features of this invention: the average value and density of the equivalent circle diameter.

[0013] In the lithographic printing plate support of the present invention, there are multiple protrusions on the surface of the anodic oxide film side of the lithographic printing plate support, and the average value of the equivalent circle diameter of the cross-section of the protrusions at a position 0.5 μm higher than the position of the average height of the protrusions is 3.0 to 10.0 μm. The average value of the equivalent circle diameter mentioned above will be explained in more detail using Figures 2 and 3. As described above, as shown in Figure 2, the surface 141A of the anodic oxide film 14A has multiple protrusions (first protrusion 16A, second protrusion 16B, third protrusion 16C). First, the average height of these protrusions is calculated, and the position P1 of that average height is identified. The method for calculating the above average height is as follows: A non-contact three-dimensional roughness meter (VertScan, manufactured by Ryoka Systems Co., Ltd.) is used to obtain non-contact 3D data for a 400 μm × 400 μm area on the surface of an anodized film. The specifications of the VertScan device and measurement conditions are as follows. (1) Equipment contents CCD camera: Sony HR-57 Objective lens: ×10 Telescope tube: ×1 Wavelength filter: 530 white (2) Measurement conditions Measurement mode: wave Field of view: 400 μm × 400 μm Scan range: Start +6μm, Stop -10μm Next, the obtained 3D data is analyzed using software (VS Viewer, manufactured by Ryoka Systems Co., Ltd.) by selecting "Full Interpolation" → "Surface Correction Polynomial" → "Quadratic" → "Particle Analysis" to identify the position P1 of the average height of the convexity. The intention of the above average height P1 of the convexity is to represent the average height obtained by averaging the height values ​​of all measurement data on the surface of the anodic oxide film within the measurement area.

[0014] Next, as shown in Figure 2, we identify a position P2 that is 0.5 μm higher than the calculated average height position P1. Next, the equivalent circle diameter of the cross-section of the convex portion at position P2 is calculated. In the embodiment shown in Figure 2, since the second convex portion 16B and the third convex portion 16C are located higher than position P2, cross-sections originating from the second convex portion 16B and the third convex portion 16C are observed in the cross-section at position P2, as shown in Figure 3. The equivalent circle diameter of each convex portion is calculated from the area of ​​the cross-section, and the average equivalent circle diameter is obtained by arithmetic mean taking the calculated values. In the embodiment shown in Figure 2, the equivalent circle diameter of the cross-sectional area of ​​the second convex portion 16B at position P2 and the equivalent circle diameter of the cross-sectional area of ​​the third convex portion 16C at position P2 are calculated, and their arithmetic mean is taken. The equivalent circle diameter is the diameter of a circle whose area is equal to the cross-sectional area of ​​each convex part in the cross-section. The above measurement is performed at five locations per sample, and the average equivalent circle diameter of the protrusion is calculated at each location. Then, the average of the five obtained values ​​is calculated, and this value is taken as the average equivalent circle diameter of the protrusion as defined in the support for lithographic printing plates of the present invention. In the present invention, it is sufficient if this value is within the above range (3.0 to 10.0 μm).

[0015] In the lithographic printing plate support of the present invention, the average value of the equivalent circle diameter is 3.0 to 10.0 μm, and is preferably 3.0 to 6.5 μm, and more preferably 3.0 to 5.0 μm, in terms of having superior scratch resistance to the lithographic printing plate original plate including the lithographic printing plate support (hereinafter also simply referred to as "the superior effect of the present invention").

[0016] In the support for a lithographic printing plate of the present invention, the density of the convex portions having a height of 0.5 μm or more from the position of the average height of the convex portions is 3000 to 9000 per mm 2 is. For example, in FIG. 2, the second convex portion 16B and the third convex portion 16C correspond to the convex portions having a height of 0.5 μm or more from the position P1 of the average height of the convex portions. Among them, in terms of more excellent effects of the present invention, the above density is 4000 to 9000 per mm 2 is preferable, and 6000 to 9000 per mm 2 is more preferable. The method for calculating the above density is as follows. First, three-dimensional data of the surface of the anodic oxide film is acquired according to the same procedure as the method for calculating the average height, and the obtained three-dimensional data is subjected to image analysis using software (SX Viewer, manufactured by Rhodamine Systems Co., Ltd.) to identify the position of the average height of the convex portions, and further, the number of convex portions having a height of 0.5 μm or more from the position of the average height of the convex portions is determined. The above measurement is performed at 5 locations for 1 sample, and the density of the convex portions (number per unit area (μm 2 )) is calculated at each location, and then the average value of the obtained 5 numerical values is determined, and this value is defined as the density of the convex portions in the support for a lithographic printing plate of the present invention. In the present invention, it is sufficient that this numerical value is within the above range (3000 to 9000 per mm 2 ).

[0017] The ratio of the density of the convex portions having a height of 0.5 μm or more from the position of the average height of the convex portions to the average value of the equivalent circle diameters (density / average value of equivalent circle diameters) is not particularly limited, but in terms of more excellent effects of the present invention, 500 (per mm 2 ) / μm or more is preferable, and 800 to 1500 (per mm 2 ) / μm is more preferable.

[0018] In the lithographic printing plate support of the present invention, the surface area ratio ΔS, calculated by the following formula (1) from the actual area Sx obtained by the approximate three-point method from three-dimensional data obtained by measuring a 25 μm × 25 μm area at 512 points on the surface of the anodic oxide film side using an atomic force microscope, and the geometrically measured area S0, is preferably 20% or more, more preferably 30% or more, and even more preferably 37% or more, in terms of superior effects of the present invention. There is no particular upper limit to the surface area ratio ΔS, but it is preferably 70% or less, and more preferably 60% or less. ΔS=(Sx-S0) / S0×100(%) (1)

[0019] In this invention, the surface area ratio ΔS refers to the value measured as follows. Specifically, a support for a lithographic printing plate is cut to a size of 1 cm square and set on a horizontal sample stage on a piezo scanner. The cantilever is then brought towards the sample surface, and when it reaches the region where interatomic forces act, it is scanned in the X and Y directions, capturing the unevenness of the sample by the displacement of the piezo in the Z direction. The piezo scanner used has a scanning range of 150 μm in the X and Y directions and 10 μm in the Z direction. The cantilever used has a resonant frequency of 130-200 kHz and a spring constant of 7-20 N / m (OMCL-AC200-TS, manufactured by Olympus Corporation), and measurements are performed in DFM mode (Dynamic Force Mode). Furthermore, the reference plane is determined by correcting for slight tilts of the sample using least-squares approximation of the obtained 3D data. Furthermore, the measurement will involve measuring 512 x 512 points on a 25 x 25 μm surface. The resolution in the X direction will be 0.05 μm, the resolution in the Y direction will be 1.9 μm, the resolution in the Z direction will be 1 nm, and the scan speed will be 18 μm / sec.

[0020] The following provides a detailed description of each component of the support structure for lithographic printing plates.

[0021] [Aluminum plate] The aluminum sheet 12 is a metal whose main component is dimensionally stable aluminum, and consists of aluminum or an aluminum alloy. Examples of the aluminum sheet 12 include a pure aluminum sheet, an alloy sheet whose main component is aluminum and which contains trace amounts of other elements, or a plastic film or paper to which aluminum (alloy) is laminated or vapor-deposited.

[0022] The non-atomous elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium, and the content of non-atomous elements in the alloy is 10% by mass or less. A pure aluminum sheet is preferred as the aluminum sheet 12, but since it is difficult to manufacture completely pure aluminum due to smelting technology, a sheet containing a small amount of non-atomous elements is also acceptable. The composition of the aluminum plate 12 is not limited, and any publicly known and publicly available material (for example, JIS A 1050, JIS A 1100, JIS A 3103, and JIS A 3005) can be used as appropriate.

[0023] Furthermore, the width of the aluminum plate 12 is preferably around 400 to 2000 mm, and the thickness is preferably around 0.1 to 0.6 mm. This width or thickness can be changed as appropriate depending on the size of the printing press, the size of the printing plate, and the user's preference.

[0024] [Anodized coating] The anodic oxide film 14A is a film generally produced on the surface of the aluminum plate 12 by anodizing treatment. Although not shown in Figures 1 and 2, it is preferable that this film has extremely fine micropores that are substantially perpendicular to the film surface and uniformly distributed. The micropores extend from the surface of the anodic oxide film 14A along the thickness direction (towards the aluminum plate 12). In this context, the term "micropore" is a commonly used term to describe pores in an anodic oxide film and does not specify the size of the pores.

[0025] The amount of anodic oxide coating is not particularly limited, but 2.0 g / m² is preferred for superior effects of the present invention. 2 The above is preferable, 3.2 g / m 2 The above is more preferable, 3.4 g / m 2 The above is even more preferable. There is no particular upper limit, but 5.0 g / m 2 In many cases, the following occurs: 4.0 g / m 2 The following cases are more common.

[0026] The density of micropores in the anodic oxide film 14A is not particularly limited, but 300 to 2000 micropores / μm is preferable for superior effects of the present invention. 2 Preferably, 500 to 1200 particles / μm 2 This is preferable. The density of micropores was determined by observing the surface of the anodic oxide film 14A with a field emission scanning electron microscope (FE-SEM) at a magnification of 150,000x (N=4 images), and the resulting four images showed a density of 400 × 600 nm. 2 This value is obtained by measuring the number of micropores present in a given range, calculating the density for each image, and averaging those values.

[0027] The average diameter (average aperture diameter) of the micropores on the surface of the anodic oxide film 14A is preferably 10 to 150 nm, and more preferably 10 to 100 nm. Among these, from the viewpoint of print resistance, 15 to 100 nm is even more preferred, 15 to 60 nm is particularly preferred, 20 to 50 nm is even more preferred, and 25 to 40 nm is most preferred. The same effect can be obtained whether the internal diameter of the micropores is wider or narrower than the surface. The average diameter of the micropores was determined by observing the surface of the anodic oxide film 14A with a field emission scanning electron microscope (FE-SEM) at a magnification of 150,000x (N=4 images), and the resulting four images showed a diameter of 400 × 600 nm. 2 This is the average value obtained by measuring the diameter of micropores within a given range. If the shape of the micropore is not circular, the equivalent diameter is used. The "equivalent diameter" is the diameter of the circle when the shape of the opening is assumed to be a circle with the same projected area as the projected area of ​​the opening.

[0028] The depth of the micropores is not particularly limited, but is preferably 10 to 3000 nm, more preferably 50 to 2000 nm, and even more preferably 300 to 1600 nm. The above depth is the average value obtained by taking a cross-sectional photograph (150,000x magnification) of the anodic oxide film 14A, measuring the depth of 25 or more micropores, and averaging the results.

[0029] The shape of the micropore is not particularly limited; it may be roughly tubular (roughly cylindrical), or conical, with the diameter decreasing towards the depth (thickness) direction. Furthermore, as will be described later, it may have a shape in which holes of different diameters are interconnected along the thickness direction. Furthermore, the shape of the bottom of the micropore is not particularly limited and may be curved (convex) or flat.

[0030] The shape of the micropores in the anodic oxide film is not particularly limited. For example, as shown in Figure 4, the anodic oxide film 14B may have a micropore 20 composed of a large-diameter pore portion 22 and a small-diameter pore portion 24. The micropores 20 in the anodic oxide film 14B consist of large-diameter pores 22 extending from the surface of the anodic oxide film 14B to a depth of 10 to 1000 nm (depth D: see Figure 4), and small-diameter pores 24 communicating with the bottom of the large-diameter pores 22 and extending from the communication point to a depth of 20 to 2000 nm. The large-diameter hole 22 and the small-diameter hole 24 will be described in detail below.

[0031] The average diameter of the large-diameter pores 22 on the surface of the anodic oxide film 14B is the same as the average diameter of the micropores in the anodic oxide film 14A described above, preferably 10 to 100 nm, more preferably 18 to 60 nm, more preferably 20 to 50 nm, and even more preferably 25 to 40 nm, from the viewpoint of print resistance. The method for measuring the average diameter of the large-diameter pores 22 on the surface of the anodic oxide film 14B is the same as the method for measuring the average diameter of micropores in the anodic oxide film 14A on the surface of the anodic oxide film.

[0032] The bottom of the large-diameter pore 22 is located at a depth of 10 to 1000 nm (hereinafter also referred to as depth D) from the surface of the anodic oxide film 14B. In other words, the large-diameter pore 22 is a pore that extends 10 to 1000 nm in the depth direction (thickness direction) from the surface of the anodic oxide film 14B. The above depth is preferably 10 to 200 nm. The above depth is the average value obtained by taking a cross-sectional photograph (150,000x magnification) of the anodic oxide film 14B, measuring the depth of 25 or more large-diameter holes 22, and averaging the results.

[0033] The shape of the large-diameter hole 22 is not particularly limited, and examples include a roughly straight tubular shape (roughly cylindrical shape) and a conical shape in which the diameter decreases towards the depth direction (thickness direction), with a roughly straight tubular shape being preferred.

[0034] As shown in Figure 4, the small-diameter hole portion 24 communicates with the bottom of the large-diameter hole portion 22 and extends further in the depth direction (thickness direction) from the communication point. The average diameter of the small-diameter holes 24 at the communication points is smaller than the average diameter of the large-diameter holes, preferably 15 nm or less. More preferably 13 nm or less. There is no particular lower limit, but it is often 5 nm or more.

[0035] The average diameter of the small-diameter pores 24 was determined by observing the surface of the anodic oxide film 14A with FE-SEM at a magnification of 150,000x (N=4 images), and in the four images obtained, the average diameter was 400 × 600 nm. 2 This value is the average of 50 micropores (small-diameter holes) within the specified range. If the depth of the large-diameter holes is deep, the upper part of the anodic oxide film 14B (the area containing the large-diameter holes) may be cut (for example, by cutting with argon gas), and then the surface of the anodic oxide film 14B may be observed with the FE-SEM described above to determine the average diameter of the small-diameter holes 24. If the shape of the small-diameter hole 24 is not circular, the equivalent diameter is used. The "equivalent diameter" is the diameter of the circle when the shape of the opening is assumed to be a circle with the same projected area as the projected area of ​​the opening.

[0036] The bottom of the small-diameter hole 24 is located 20 to 2000 nm further in the depth direction from the point of communication with the large-diameter hole 22. In other words, the small-diameter hole 24 is a hole that extends further in the depth direction (thickness direction) from the point of communication with the large-diameter hole 22, and the depth of the small-diameter hole 24 is 20 to 2000 nm. Preferably, the depth is 500 to 1500 nm. The above depth is the average value obtained by taking a cross-sectional photograph (50,000x magnification) of the anodic oxide film 14B, measuring the depth of 25 or more small-diameter holes 24, and averaging the results.

[0037] The shape of the small-diameter hole portion 24 is not particularly limited, and examples include a roughly straight tubular shape (roughly cylindrical shape) and a conical shape in which the diameter decreases towards the depth direction, with a roughly straight tubular shape being preferred.

[0038] Furthermore, as shown in Figure 5, for example, the anodic oxide film 14C may have a micropore 30 composed of an upper pore 32 and a lower pore 34. The micropores 30 in the anodic oxide film 14C consist of an upper pore portion 32 extending in the depth direction from the surface of the anodic oxide film 14C, and a lower pore portion 34 that communicates with the bottom of the upper pore portion 32 and extends further to a depth of 20 to 2000 nm from the communication point. The upper pore portion 32 consists of a small-diameter upper pore portion 36 extending in the depth direction from the surface of the anodic oxide film 14C, and a large-diameter upper pore portion 38 that communicates with the bottom of the small-diameter upper pore portion 36 and extends further in the depth direction.

[0039] The average diameter of the upper pores 32 on the surface of the anodic oxide film 14C is the same as the average diameter of the micropores on the surface of the anodic oxide film in the anodic oxide film 14A described above, and is preferably 10 to 100 nm, preferably 18 to 60 nm, more preferably 20 to 50 nm, even more preferably 25 to 40 nm, and particularly preferably 25 to 40 nm, from the viewpoint of print resistance. The method for measuring the average diameter of the upper pores 32 on the surface of the anodized film 14C is the same as the method for measuring the average diameter of micropores on the surface of the anodized film 14A.

[0040] The maximum diameter of the upper hole 32 is not particularly limited, but from the viewpoint of print resistance, it is preferably 200 nm or less, and more preferably 50 to 150 nm. Furthermore, the ratio of the maximum diameter of the upper pores 32 to the average diameter of the upper pores 32 on the surface of the anodized film 14C is not particularly limited, but from the viewpoint of print resistance, it is preferably 1.2 or more, and more preferably 2.0 to 6.0. As shown in Figure 5, the upper hole 32 is composed of a small-diameter upper hole 36 and a large-diameter upper hole 38 with a larger inner diameter than the small-diameter upper hole 36. Therefore, the maximum diameter of the upper hole 32 corresponds to the inner diameter of the large-diameter upper hole 38. The shape of the upper hole 32 is not limited to the configuration shown in Figure 5. For example, it may have a shape in which the inner diameter gradually increases from the average diameter on the surface of the anodic oxide film 14C towards the depth.

[0041] As shown in Figure 5, the lower hole 34 communicates with the bottom of the upper hole 32 and extends further in the depth direction (thickness direction) beyond the communication point. The average diameter of the small-diameter holes 24 at the communication points is smaller than the average diameter of the large-diameter holes, preferably 15 nm or less. More preferably 13 nm or less. There is no particular lower limit, but it is often 5 nm or more.

[0042] The average diameter of the lower pore 34 was determined by observing the surface of the anodized film 14A with FE-SEM at a magnification of 150,000x (N=4 images), and in the four images obtained, the diameter was 400 × 600 nm. 2 This value is the average of 50 micropores (small-diameter holes) within the specified range. If the depth of the large-diameter holes is deep, the upper part of the anodic oxide film 14C (the area containing the upper holes) may be cut (for example, by cutting with argon gas), and then the surface of the anodic oxide film 14C may be observed with the FE-SEM described above to determine the average diameter of the lower holes 34. If the shape of the lower hole 34 is not circular, the equivalent diameter of a circle is used. The "equivalent diameter of a circle" is the diameter of a circle when the shape of the opening is assumed to be a circle with the same projected area as the projected area of ​​the opening.

[0043] The bottom of the lower hole 34 is located 20 to 2000 nm further in the depth direction from the point of communication with the upper hole 32. In other words, the lower hole 34 is a hole that extends further in the depth direction (thickness direction) from the point of communication with the upper hole 32, and the depth of the lower hole 34 is 20 to 2000 nm. Preferably, the depth is 500 to 1500 nm. The above depth is the average value obtained by taking a cross-sectional photograph (50,000x magnification) of the anodic oxide film 14C, measuring the depth of 25 or more lower pores 34, and averaging the results.

[0044] The shape of the lower hole 34 is not particularly limited, and examples include a roughly straight tubular shape (roughly cylindrical shape) and a conical shape in which the diameter decreases towards the depth direction, with a roughly straight tubular shape being preferred.

[0045] [Method for manufacturing a support for a lithographic printing plate] The method for manufacturing a support for a lithographic printing plate according to the present invention is not particularly limited, but in order to efficiently manufacture a predetermined support for a lithographic printing plate, it is preferable to have a hydrochloric acid electrolytic treatment step in which an aluminum plate is subjected to alternating electrolysis in a hydrochloric acid treatment solution which may contain sulfuric acid to produce a roughened aluminum plate. In particular, when performing the electrolytic treatment in the hydrochloric acid electrolytic treatment step, it is preferable to perform the electrolytic treatment in 10 or more steps with predetermined rest periods in between. That is, it is preferable to perform an operation in which electrolytic treatment and rest periods of predetermined time are repeatedly performed over a predetermined period of time, so that the number of electrolytic treatments is 10 or more. Furthermore, it is preferable that the method for manufacturing a support for a lithographic printing plate of the present invention includes an anodic oxidation step, after the hydrochloric acid electrolytic treatment step, in which the roughened aluminum plate is subjected to an anodic oxidation treatment to form an anodic oxide film of aluminum on the aluminum plate. Furthermore, it is preferable that the method for manufacturing a support for a lithographic printing plate of the present invention includes a pore-widening step, in which, after the anodic oxidation treatment step, an etching treatment is performed on the aluminum plate on which the anodic oxide film has been formed, thereby increasing the diameter of the micropores in the anodic oxide film. The following details each of the processes and any optional procedures described above.

[0046] <Mechanical surface roughening treatment> The present invention's method for manufacturing a support for a lithographic printing plate may include a mechanical roughening treatment before the hydrochloric acid electrolytic treatment step. As mechanical surface roughening treatment methods, for example, the wire brush grain method, which involves scratching the aluminum surface with a metal wire, the ball grain method, which involves roughening the aluminum surface with abrasive balls and an abrasive, and the brush grain method, which involves roughening the surface with a nylon brush and an abrasive, as described in Japanese Patent Publication No. Hei 6-135175 and Japanese Patent Publication No. Sho 50-040047, can be used.

[0047] <Hydrochloric acid electrolysis process> The hydrochloric acid electrolytic treatment step in the method for manufacturing a support for a lithographic printing plate of the present invention is preferably a hydrochloric acid electrolytic treatment step in which an aluminum plate is subjected to electrolytic treatment 10 or more times in a hydrochloric acid treatment solution which may contain sulfuric acid, with predetermined rest periods in between, in order to produce a roughened aluminum plate. In the present invention, by performing such hydrochloric acid electrolytic treatment and then the anodic oxidation treatment described later, the above-mentioned support for lithographic printing plates can be efficiently manufactured.

[0048] When performing AC electrolysis, it is preferable to perform AC electrolysis multiple times with rest periods in between, as described above. The pause time between each AC electrolysis is preferably 0.3 to 3.0 seconds, and more preferably 0.5 to 1.5 seconds. The number of times AC electrolysis is performed is preferably 10 or more, and more preferably 12 or more. There is no particular upper limit, but it is often 20 times or less.

[0049] The hydrochloric acid treatment solution contains hydrochloric acid, and the hydrochloric acid concentration is preferably 5 to 30 g / L, and more preferably 10 to 20 g / L. The hydrochloric acid treatment solution may contain sulfuric acid. If the hydrochloric acid treatment solution contains sulfuric acid, the sulfuric acid concentration in the hydrochloric acid treatment solution is preferably 2.0 g / L or less, and more preferably 1.5 g / L or less. If the hydrochloric acid treatment solution contains sulfuric acid, there is no particular lower limit to the sulfuric acid concentration in the hydrochloric acid treatment solution, and it may be greater than 0 g / L. The hydrochloric acid treatment solution may contain aluminum ions. If the hydrochloric acid treatment solution contains aluminum ions, the concentration of aluminum ions is preferably 1.0 to 30.0 g / L, and more preferably 5.0 to 20.0 g / L. If the hydrochloric acid treatment solution contains sulfuric acid, it is preferable that the ratio of sulfuric acid content to hydrochloric acid content be 0.1 or less. There is no particular lower limit, and a value greater than 0 is acceptable. The temperature of the hydrochloric acid treatment solution is not particularly limited, but is preferably 30°C or lower, more preferably 25°C or lower, and even more preferably 20°C or lower. The lower limit is not particularly limited, but is preferably 5°C or higher, and more preferably 10°C or higher.

[0050] In this invention, the total amount of electricity (the total amount of electricity involved in the anode reaction of the aluminum plate at the time the hydrochloric acid electrolysis treatment is completed) is 400 C / dm 2 The following is preferable: 375C / dm 2 The following is preferable: There is no particular lower limit to the total amount of electricity, but 50 C / dm 2 The above is preferable, 100C / dm 2 The above is preferable. The peak current value of the AC current waveform is 80 A / dm 2 The following is preferable: 70 A / dm 2 The following is more preferable: The above peak current value is 10A / dm 2 The above is preferable, 20A / dm 2 The above is preferable.

[0051] The alternating current waveform used in hydrochloric acid electrolysis can be a sine wave, square wave, trapezoidal wave, or triangular wave. A frequency of 0.1 to 250 Hz is preferred. Figure 6 is a graph showing an example of an alternating waveform current waveform diagram used in hydrochloric acid electrolysis. In Figure 6, ta is the anode reaction time, tc is the cathode reaction time, tp is the time from zero to the peak current, Ia is the peak current on the anode cycle side, and Ic is the peak current on the cathode cycle side. For a trapezoidal wave, the time tp from zero to the peak current is preferably 1 to 10 msec. The conditions for one cycle of AC used in hydrochloric acid electrolysis are preferably in the range of tc / ta, where the ratio of the anode reaction time ta to the cathode reaction time tc of the aluminum plate is 1 to 20, the ratio of the electric charge Qc to the electric charge Qa of the aluminum plate at the anode is 0.3 to 20, and the anode reaction time ta is 5 to 1000 msec. The current density is within the range described above (80 A / dm²) for both the anode cycle side Ia and the cathode cycle side Ic at the peak value of the trapezoidal wave. 2 The following is preferable:

[0052] For hydrochloric acid electrolysis using alternating current, the apparatus shown in Figure 7 can be used. Figure 7 is a side view showing an example of a radial cell used in hydrochloric acid electrolysis using alternating current. In Figure 7, 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 passage, 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 may be the same or different. The aluminum plate W is wound onto a radial drum roller 52 which is immersed in the main electrolytic cell 50 and subjected to electrolytic treatment by main electrodes 53a and 53b connected to an AC power supply 51 during the transport process. The electrolyte 55 is supplied from the electrolyte supply port 54 through a slit 56 to the electrolyte passage 57 between the radial drum roller 52 and the main electrodes 53a and 53b. The aluminum plate W, which has been treated in the main electrolytic cell 50, is then subjected to electrolytic treatment in an auxiliary anode cell 60. In this auxiliary anode cell 60, an auxiliary anode 58 is positioned opposite the aluminum plate W, and the electrolyte 55 is supplied so as to flow through the space between the auxiliary anode 58 and the aluminum plate W.

[0053] <Alkaline etching treatment> In the method for manufacturing a support for a lithographic printing plate of the present invention, it is preferable to perform an alkaline etching treatment after the mechanical roughening treatment described above, or before or after the hydrochloric acid electrolytic treatment step described above. However, the alkaline etching treatment may be omitted. Furthermore, the alkaline etching treatment, which is performed before the hydrochloric acid electrolytic treatment, is intended to remove rolling oil, dirt, and natural oxide film from the surface of the aluminum plate (rolled aluminum) if mechanical surface roughening treatment has not been performed, and if mechanical surface roughening treatment has already been performed, it is intended to dissolve the edges of the irregularities created by the mechanical surface roughening treatment, thereby changing the sharp irregularities into a smooth, undulating surface.

[0054] If mechanical surface roughening is not performed before alkaline etching, the etching amount is 0.1 to 10 g / m². 2 Preferably, it is 1-5 g / m 2 It is more preferable that the etching amount is 1 to 10 g / m². 2 This ensures that the surface is thoroughly cleaned of rolling oil, dirt, and natural oxide film.

[0055] When mechanical surface roughening is performed before alkaline etching, the etching amount is 3-20 g / m². 2 Preferably, it is 5-15 g / m 2 It is preferable that this is the case.

[0056] Alkaline etching, performed immediately after hydrochloric acid electrolysis, is intended to dissolve the smut generated in the acidic electrolyte and to dissolve the edges of the irregularities formed by the hydrochloric acid electrolysis. The optimal etching amount differs because the irregularities formed by hydrochloric acid electrolysis vary depending on the type of electrolyte, but the etching amount when performing alkaline etching after hydrochloric acid electrolysis is 0 g / m². 2 Super 0.50g / m 2 Preferably, it is 0 g / m 2 Super 0.30g / m 2 It is more preferable to have 0 g / m², as it offers superior print durability.2 Super 0.20g / m 2 The following is even more preferable:

[0057] Examples of alkalis used in alkaline solutions include caustic alkalis and alkali metal salts. Aqueous solutions of caustic soda are particularly preferred.

[0058] The concentration of the alkaline solution can be determined according to the amount of etching, but is preferably 1 to 50% by mass, and more preferably 10 to 35% by mass. If aluminum ions are dissolved in the alkaline solution, the concentration of aluminum ions is preferably 0.01 to 10% by mass, and more preferably 3 to 8% by mass. The temperature of the alkaline solution is preferably 20 to 90°C. The processing time is preferably 0 to 120 seconds.

[0059] Methods for bringing an aluminum plate into contact with an alkaline solution include, for example, passing the aluminum plate through a tank containing an alkaline solution, immersing the aluminum plate in a tank containing an alkaline solution, and spraying the alkaline solution onto the surface of the aluminum plate.

[0060] <Desmatting> In the method for manufacturing a support for a lithographic printing plate of the present invention, it is preferable that after hydrochloric acid electrolytic treatment or alkaline etching treatment, acid pickling (desmatt treatment) is performed to remove corrosive organisms remaining on the surface. Commonly used acids include nitric acid, sulfuric acid, and hydrochloric acid, but other acids may also be used. The above desmatt treatment is carried out, for example, by contacting the aluminum plate with an acidic solution of 0.5 to 30% by mass (containing 0.01 to 5% by mass of aluminum ions), such as hydrochloric acid, nitric acid, and sulfuric acid. Methods for bringing an aluminum plate into contact with an acidic solution include, for example, passing the aluminum plate through a tank containing the acidic solution, immersing the aluminum plate in a tank containing the acidic solution, and spraying the acidic solution onto the surface of the aluminum plate. The surface condition of the aluminum plate after desmatt treatment affects the subsequent growth of the natural oxide film; therefore, the choice of acid, concentration, and temperature conditions are selected appropriately according to the purpose.

[0061] <Water washing treatment> In the method for manufacturing a support for a lithographic printing plate of the present invention, it is preferable to perform water washing after the completion of each of the above-described processing steps. In particular, the water washing performed at the end of the process should be carried out thoroughly using pure water, well water, or tap water, as it affects the subsequent growth of the natural oxide film.

[0062] <Anodizing process> The above-described anodizing process involves applying an anodizing treatment to the roughened aluminum plate after the hydrochloric acid electrolytic treatment process described above, thereby forming an anodic oxide film of aluminum on the aluminum plate. Here, the procedure for the above-mentioned anodic oxidation process is not particularly limited, and known methods can be cited. In the anodizing process, aqueous solutions of sulfuric acid, phosphoric acid, and oxalic acid can be used as the electrolytic bath. For example, the concentration of sulfuric acid can range from 0.1 to 300 g / L. The conditions for the anodizing process are appropriately set depending on the electrolyte used, but for example, the electrolyte temperature is 5 to 70°C (preferably 10 to 60°C) and the current density is 0.5 to 60 A / dm². 2 (preferably 5-60 A / dm 2 ), voltage 1 to 100V (preferably 5 to 50V), electrolysis time 1 to 100 seconds (preferably 5 to 60 seconds), and film thickness 0.1 to 5 g / m² 2 (Preferably 0.2-3 g / m 2 ) are some examples.

[0063] <Pore-wide processing process> The above-described pore widening process is a process in which, after the anodizing process described above, an etching process is applied to the aluminum plate on which the anodic oxide film has been formed, thereby increasing the diameter of the micropores in the anodic oxide film (pore diameter enlargement process). Pore ​​widening can be performed by contacting the aluminum plate obtained by the anodic oxidation process described above with an acidic aqueous solution or an alkaline aqueous solution. The method of contact is not particularly limited and examples include immersion and spraying methods.

[0064] The method for manufacturing the anodic oxide film 14B shown in Figure 4 above is not particularly limited, but a manufacturing method in which the following steps are carried out in order is preferred. (Hydrochloric acid electrolytic treatment process) A process in which the aluminum plate is subjected to the hydrochloric acid electrolytic treatment described above. (First Anodizing Process) An anodizing process for a roughened aluminum plate. (Pore widening process) A process in which an aluminum plate having an anodic oxide film obtained in the first anodic oxidation process is brought into contact with an acidic aqueous solution or an alkaline aqueous solution to enlarge the diameter of micropores in the anodic oxide film. (Second Anodizing Process) An anodizing process for the aluminum plate obtained in the pore-widening process. The procedures for each step can be found by referring to known methods. Furthermore, the method for manufacturing the anodic oxide film 14C shown in Figure 5 is not particularly limited, but one method is to perform three anodic oxidation treatments.

[0065] [Lithographic printing plate original plate] The lithographic printing plate master of the present invention includes the above-described support for the lithographic printing plate. More specifically, the lithographic printing plate master 40 shown in Figure 8 has a lithographic printing plate support 42 and an image recording layer 46 disposed on the lithographic printing plate support 42. Preferably, as shown in Figure 8, there is an additional undercoat layer 44 between the lithographic printing plate support 42 and the image recording layer 46. The undercoat layer 44 is made of any material. The structure of the lithographic printing plate support 42 is as described above, with the anodic oxide film in the lithographic printing plate support 42 being positioned on the image recording layer side. The following sections will detail the other components included in the lithographic printing plate.

[0066] [Undercoat layer] The undercoat layer 44 is a layer placed between the lithographic printing plate support 42 and the image recording layer 46, and improves the adhesion between the two. As mentioned above, the undercoat layer 44 is a layer that is provided as needed and does not have to be included in the lithographic printing plate master.

[0067] The composition of the undercoat layer is not particularly limited, but it is preferable to include polyvinylphosphonic acid in order to suppress ink adhesion to non-image areas while maintaining print durability. Here, as polyvinylphosphonic acid, those disclosed in U.S. Patent No. 3,276,868, No. 4,153,461, and No. 4,689,272 can be used.

[0068] The composition of the undercoat layer is not particularly limited, but it is preferable to include a compound containing a betaine structure in order to obtain good stain resistance and ease of wiping off. Here, a betaine structure refers to a structure having at least one cation and at least one anion. Normally, the number of cations and anions are equal, and the overall structure is neutral. However, in this invention, if the number of cations and anions are not equal, a betaine structure is also defined as having the necessary amount of counterions to cancel out the charge. The betaine structure is preferably one of the structures represented by the following formulas (1), (2), and (3).

[0069] [ka]

[0070] In the formula, A - represents a structure containing anions, B + L represents a structure having a cation. 0 * represents a linking group. * represents a linking site (linking position). A - It is preferable that this represents a structure having anions such as carboxylates, sulfonates, phosphonates, and phosphinates, B +Preferably, this represents a structure having cations such as ammonium, phosphonium, iodonium, and sulfonium.

[0071] L 0 represents a linking group. In formulas (1) and (3), L 0 Examples of divalent linking groups include -CO-, -O-, -NH-, divalent aliphatic groups, divalent aromatic groups, or combinations thereof. In formula (2), L 0 One example is the trivalent linking group. The above-mentioned linking group is preferably a linking group with 30 or fewer carbon atoms, including the number of carbon atoms of the substituents that may be present as described later. Specific examples of the above-mentioned linking groups include alkylene groups (preferably with 1 to 20 carbon atoms, more preferably with 1 to 10 carbon atoms), and arylene groups such as phenylene and xylylene groups (preferably with 5 to 15 carbon atoms, more preferably with 6 to 10 carbon atoms).

[0072] These linking groups may have further substituents. Examples of substituents include halogen atoms, hydroxyl groups, carboxyl groups, amino groups, cyano groups, aryl groups, alkoxy groups, aryloxy groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, acyloxy groups, monoalkylamino groups, dialkylamino groups, monoarylamino groups, and diarylamino groups.

[0073] As a betaine structure, the structure represented by formula (i), formula (ii), or formula (iii) is preferred, with the structure represented by formula (i) being more preferred, in that it is superior in at least one of the following: print resistance, stain resistance, resistance to being wiped off when left unattended, and image visibility. * indicates a connecting portion.

[0074] [ka]

[0075] In equation (i), R 1 and R2 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R 1 and R 2 These elements may be connected to each other, forming a ring structure. The ring structure may contain heteroatoms such as oxygen atoms. A 5- to 10-membered ring is preferred, and a 5 or 6-membered ring is more preferred. R 1 and R 2 The number of carbon atoms in the molecule is preferably 1 to 30, and more preferably 1 to 20. R 1 and R 2 A hydrogen atom, a methyl group, or an ethyl group is preferred.

[0076] L 1 The group represents a divalent linking group, preferably -CO-, -O-, -NH-, a divalent aliphatic group (e.g., alkylene group), a divalent aromatic group (e.g., phenylene group), or a combination thereof. L 1 A linear alkylene group having 3 to 5 carbon atoms is preferred.

[0077] In equation (i), A - The symbol represents a structure having an anion, and carboxylates, sulfonates, phosphonates, or phosphinates are preferred. Specifically, the following structures can be cited.

[0078] [ka]

[0079] In equation (i), L 1 A is a linear alkylene group having 4 or 5 carbon atoms, and A - A combination in which is a sulfonate is preferred, L 1 A is a linear alkylene group having 4 carbon atoms, and A - A combination in which the compound is a sulfonate is more preferable.

[0080] In equation (ii), L 2 The group represents a divalent linking group, preferably -CO-, -O-, -NH-, a divalent aliphatic group (e.g., alkylene group), a divalent aromatic group (e.g., phenylene group), or a combination thereof. B + The symbol represents a structure having a cation, and structures having ammonium, phosphonium, iodonium, or sulfonium are preferred. Among these, structures having ammonium or phosphonium are preferred, and structures having ammonium are more preferred. Examples of structures having a cation include trimethylammonium group, triethylammonium group, tributylammonium group, benzyldimethylammonium group, diethylhexylammonium group, (2-hydroxyethyl)dimethylammonium group, pyridinio group, N-methylimidazolio group, N-acridinio group, trimethylphosphonio group, triethylphosphonio group, and triphenylphosphonio group.

[0081] In equation (iii), L 3 The group represents a divalent linking group, and is preferably -CO-, -O-, -NH-, a divalent aliphatic group (e.g., alkylene group), a divalent aromatic group (e.g., phenylene group), or a combination thereof. A - A represents a structure having an anion, preferably a carboxylate, sulfonate, phosphonate, or phosphinate, and details and preferred examples are shown in formula (i) A - It is similar to that. R 3 ~R 7 Each of these independently represents a hydrogen atom or a substituent (preferably with 1 to 30 carbon atoms), and R 3 ~R 7 At least one of them represents a connecting part. The connecting part R 3 ~R 7 At least one of them is R 3 ~R 7 It may be linked to other sites in the compound via substituents, at least one of them, or it may be directly linked to other sites in the compound by a single bond.

[0082] R 3 ~R 7 Examples of the substituent represented by 3 ~ 7 include a halogen atom, an alkyl group (including a cycloalkyl group and a bicycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group (including an anilino group), an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfamoylamino group, an alkyl and arylsulfonylamino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfamoyl group, a sulfo group, an alkyl and arylsulfinyl group, an alkyl and arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an aryl and heterocyclic azo group, an imide group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, and a silyl group.

[0083] The above compound is preferably a polymer containing a repeating unit having a betaine structure (hereinafter also simply referred to as "specific polymer"). As the repeating unit having a betaine structure, a repeating unit represented by formula (A1) is preferable.

[0084] [[ID=十四]] [[ID=十五]] [[ID=十六]]

Chemical formula

[0085] [[ID=二十二]] In the formula, R 101 ~R 103 each independently represents a hydrogen atom, an alkyl group, or a halogen atom. L represents a single bond or a divalent linking group. Examples of divalent linking groups include -CO-, -O-, -NH-, divalent aliphatic groups, divalent aromatic groups, or combinations thereof.

[0086] Specific examples of L consisting of the above combinations are given below. In the examples below, the left side is bound to the main chain, and the right side is bound to X. L1:-CO-O-divalent aliphatic group- L2:-CO-O-divalent aromatic group- L3:-CO-NH-divalent aliphatic group- L4:-CO-NH-divalent aromatic group- L5:-CO- divalent aliphatic group- L6:-CO-divalent aromatic group- L7:-CO-divalent aliphatic group-CO-O-divalent aliphatic group- L8:-CO- divalent aliphatic group-O-CO- divalent aliphatic group- L9:-CO-divalent aromatic group-CO-O-divalent aliphatic group- L10:-CO-divalent aromatic group-O-CO-divalent aliphatic group- L11:-CO-divalent aliphatic group-CO-O-divalent aromatic group- L12:-CO-divalent aliphatic group-O-CO-divalent aromatic group- L13:-CO-divalent aromatic group-CO-O-divalent aromatic group- L14:-CO-divalent aromatic group-O-CO-divalent aromatic group- L15:-CO-O-divalent aromatic group-O-CO-NH-divalent aliphatic group- L16:-CO-O-divalent aliphatic group-O-CO-NH-divalent aliphatic group-

[0087] Examples of divalent aliphatic groups include alkylene groups, alkenylene groups, and alkynylene groups. Examples of divalent aromatic groups include aryl groups, with phenylene or naphthylene groups being preferred.

[0088] X represents a betaine structure. X is preferably a structure represented by formula (i), formula (ii), or formula (iii) described above. In particular, in equation (A1), L is either L1 or L3, and X is the structure represented by equation (i), and A in equation (i) - A combination in which is a sulfonate group is preferred.

[0089] The content of repeating units having a betaine structure in a specific polymer is not particularly limited, and is often 20 to 95% by mass, preferably 50 to 95% by mass and more preferably 60 to 90% by mass relative to the total repeating units constituting the specific polymer.

[0090] The specific polymer may contain repeating units other than the repeating units having the betaine structure described above. The specific polymer may contain repeating units having a structure that interacts with the surface of the support for the lithographic printing plate (hereinafter also simply referred to as the "interacting structure"). Examples of interacting structures include carboxylic acid structures, carboxylate salt structures, sulfonic acid structures, sulfonate salt structures, phosphonic acid structures, phosphonate salt structures, phosphate ester structures, phosphate ester salt structures, β-diketone structures, and phenolic hydroxyl groups. For example, structures represented by the following formulas are included. Among these, carboxylic acid structures, carboxylate salt structures, sulfonic acid structures, sulfonate salt structures, phosphonic acid structures, phosphonate salt structures, phosphate ester structures, or phosphate ester salt structures are preferred.

[0091] [ka]

[0092] In the above formula, R 11 ~R 13 Each of the following independently represents a hydrogen atom, an alkyl group, an aryl group, an alkynyl group, or an alkenyl group. M, M1, and M2 each independently represent a hydrogen atom, a metal atom (e.g., an alkali metal atom such as Na or Li), or an ammonium group. B represents a boron atom.

[0093] The repeating unit having an interaction structure is preferably the repeating unit represented by formula (A2).

[0094] [ka]

[0095] In the formula, R 201 ~R 203 Each of these independently represents a hydrogen atom, an alkyl group (preferably having 1 to 6 carbon atoms), or a halogen atom. L represents a single bond or a divalent linking group. Examples of divalent linking groups include -CO-, -O-, -NH-, divalent aliphatic groups, divalent aromatic groups, or combinations thereof. Specific examples of L consisting of combinations include the same as formula (A1) above, as well as L17 and L18 below. L17:-CO-NH- L18:-CO-O- Among L1 to L18, L1 to L4, L17, or L18 are preferred. Q represents the interaction structure, and the preferred embodiment is the same as described above.

[0096] The content of repeating units having an interaction structure in a specific polymer is not particularly limited, but it is preferably 1 to 40% by mass, and more preferably 3 to 30% by mass, relative to the total repeating units constituting the specific polymer.

[0097] The specific polymer may contain repeating units having radically polymerizable reactive groups. Examples of radically polymerizable reactive groups include addition polymerizable unsaturated bonding groups (e.g., (meth)acryloyl group, (meth)acrylamide group, (meth)acrylonitrile group, allyl group, vinyl group, vinyloxy group, and alkynyl group) and chain transfer-capable functional groups (such as mercapto groups). A specific polymer containing repeating units having radical polymerizable reactive groups can be obtained by introducing radical polymerizable reactive groups by the method described in Japanese Patent Application Publication No. 2001-312068. By using a specific polymer containing repeating units having radical polymerizable reactive groups, excellent developability is achieved in the unexposed areas, and in the exposed areas, the penetration of the developer is suppressed by polymerization, further improving the adhesion and bonding between the support for the lithographic printing plate and the image recording layer.

[0098] The content of repeating units having radical polymerizable reactive groups in the specific polymer is not particularly limited, but it is preferably 1 to 30% by mass, and more preferably 3 to 20% by mass, relative to the total repeating units constituting the specific polymer.

[0099] The content of the compound having the betaine structure in the undercoat layer 44 is not particularly limited, but it is preferably 80% by mass or more, and more preferably 90% by mass or more, relative to the total mass of the undercoat layer. The upper limit is 100% by mass.

[0100] Although the above description refers to an undercoat containing a compound having a betaine structure, the undercoat may also contain other compounds. For example, the undercoat layer may be in a form that contains a compound having a hydrophilic group. Examples of hydrophilic groups include carboxylic acid groups and sulfonic acid groups. Compounds having hydrophilic groups may further have radical polymerizable reactive groups.

[0101] [Image recording layer] The image recording layer 46 is preferably an image recording layer that can be removed by printing ink and / or dampening solution. The following describes each component of the image recording layer 46.

[0102] <Infrared absorbent> The image recording layer 46 preferably contains an infrared absorbent. The infrared absorber preferably has a maximum absorption in the wavelength range of 750 to 1400 nm. In particular, in the case of an on-machine developing type lithographic printing plate original plate, since it may be developed on a printing press under white light, by using an infrared absorber having a maximum absorption in the wavelength range of 750 to 1400 nm that is less affected by white light, a lithographic printing plate original plate excellent in developability can be obtained. As the infrared absorber, a dye or a pigment is preferred.

[0103] Examples of the dye include commercially available dyes and known dyes described in documents such as "Dye Handbook" (edited by the Society of Synthetic Organic Chemistry, published in 1970). Specific examples of the dye include cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Among them, cyanine dyes or indolenine cyanine dyes are preferred, cyanine dyes are more preferred, and cyanine dyes represented by the following formula (a) are even more preferred.

[0104] Formula (a)

Chemical formula

[0105] In formula (a), X 1 represents a hydrogen atom, a halogen atom, -N(R 9 )(R 10 ), -X 2 -L 1 , or a group shown below.

[0106]

Chemical formula

[0107] R 9 and R 10 each independently represent an aromatic hydrocarbon group, an alkyl group, or a hydrogen atom, and R 9 and R 10 may be bonded to each other to form a ring. Among them, a phenyl group is preferred. X2 represents an oxygen atom or a sulfur atom, L 1 This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain heteroatoms (N, S, O, halogen atoms, Se). X a - This will be explained later in Z a - Defined similarly, R a This represents a hydrogen atom, alkyl group, aryl group, amino group, or halogen atom.

[0108] R 1 and R 2 Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms. Also, R 1 and R 2 These elements may bond to each other to form a ring, and when a ring is formed, it is preferable that a 5-membered or 6-membered ring is formed. Ar 1 and Ar 2 Each of these independently represents an aromatic hydrocarbon group which may have substituents (e.g., alkyl groups). A benzene ring group or a naphthalene ring group is preferred as the aromatic hydrocarbon group. Y 1 and Y 2 Each of these independently represents either a sulfur atom or a dialkylmethylene group with 12 or fewer carbon atoms. R 3 and R 4 Each of these independently represents a hydrocarbon group having 20 or fewer carbon atoms, which may have substituents (e.g., alkoxy groups). R 5 , R 6 , R 7 and R 8 Each of these independently represents either a hydrogen atom or a hydrocarbon group with 12 or fewer carbon atoms. Also, Za - represents a counter anion. However, if the cyanine dye shown in formula (a) has an anionic substituent in its structure and charge neutralization is not required, Za - It's not necessary. -Examples include halide ions, perchlorate ions, tetrafluoroborate ions, hexafluorophosphate ions, and sulfonate ions, with perchlorate ions, hexafluorophosphate ions, or arylsulfonate ions being preferred.

[0109] The above infrared absorbing dyes may be used individually, or two or more may be used in combination, or infrared absorbing agents other than infrared absorbing dyes, such as pigments, may be used in combination. As pigments, compounds described in paragraphs

[0072] to

[0076] of Japanese Patent Application Publication No. 2008-195018 are preferred.

[0110] The amount of infrared absorbent is preferably 0.05 to 30% by mass, and more preferably 0.1 to 20% by mass, relative to the total mass of the image recording layer.

[0111] <Polymerization initiator> The image recording layer 46 preferably contains a polymerization initiator. Preferred polymerization initiators are compounds that generate radicals in response to light, heat, or both, and initiate the polymerization of compounds having polymerizable unsaturated groups (so-called radical polymerization initiators). Examples of polymerization initiators include photopolymerization initiators and thermal polymerization initiators. Specifically, the polymerization initiators described in paragraphs

[0115] to

[0141] of Japanese Patent Publication No. 2009-255434 can be used as polymerization initiators. Furthermore, from the viewpoint of reactivity and stability, oxime ester compounds or onium salts such as diazonium salts, iodonium salts, and sulfonium salts are preferred as polymerization initiators.

[0112] The polymerization initiator content is preferably 0.1 to 50% by mass, and more preferably 0.5 to 30% by mass, relative to the total mass of the image recording layer.

[0113] <Polymerizable compound> The image recording layer 46 preferably contains a polymerizable compound. As polymerizable compounds, addition polymerizable compounds having at least one ethylenically unsaturated bond are preferred. Among these, compounds having at least one (preferably two or more) terminal ethylenically unsaturated bonds are more preferred. So-called radical polymerizable compounds are even more preferred. As polymerizable compounds, for example, polymerizable compounds exemplified in paragraphs

[0142] to

[0163] of Japanese Patent Publication No. 2009-255434 can be used.

[0114] Furthermore, urethane-based addition polymerizable compounds produced by an addition reaction between isocyanate and hydroxyl groups are also suitable. Specific examples include vinyl urethane compounds containing two or more polymerizable vinyl groups per molecule, obtained by adding a vinyl monomer containing a hydroxyl group represented by the following formula (A) to a polyisocyanate compound having two or more isocyanate groups per molecule, as described in Japanese Patent Publication No. 48-041708. CH2=C(R 4 )COOCH2CH(R 5 )OH (A) (However, R 4 and R 5 (This represents H or CH3.)

[0115] The polymerizable compound content is preferably 3 to 80% by mass, and more preferably 10 to 75% by mass, relative to the total mass of the image recording layer.

[0116] <Binder Polymer> The image recording layer 46 preferably contains a binder polymer. Examples of binder polymers include well-known binder polymers. Specifically, examples of binder polymers include acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, methacrylic resins, polystyrene resins, novolac-type phenolic resins, polyester resins, synthetic rubber, and natural rubber. The binder polymer may have crosslinking properties to improve the film strength of the image area. To give the binder polymer crosslinking properties, crosslinking functional groups, such as ethylenically unsaturated bonds, can be introduced into the main chain or side chains of the polymer. The crosslinking functional groups may also be introduced by copolymerization. As the binder polymer, for example, the binder polymer disclosed in paragraphs

[0165] to

[0172] of Japanese Patent Application Publication No. 2009-255434 can be used.

[0117] The binder polymer content is preferably 5 to 90% by mass, and more preferably 5 to 70% by mass, relative to the total mass of the image recording layer.

[0118] <Surfactants> The image recording layer 46 may contain a surfactant to promote on-press developability at the start of printing and to improve the surface condition of the coating. Examples of surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorinated surfactants. As a surfactant, for example, the surfactants disclosed in paragraphs

[0175] to

[0179] of Japanese Patent Application Publication No. 2009-255434 can be used.

[0119] The surfactant content is preferably 0.001 to 10% by mass, and more preferably 0.01 to 5% by mass, relative to the total mass of the image recording layer.

[0120] <Coloring agent> The image recording layer 46 preferably contains a color developer, and more preferably contains an acid color developer. As used in this disclosure, "chromogen" means a compound that changes the color of an image recording layer by changing color or decolorizing in response to stimuli such as light or acid, and "acid chromogen" means a compound that changes the color of an image recording layer by changing color or decolorizing when heated while accepting an electron-accepting compound (e.g., a proton such as an acid). As acid chromogens, colorless compounds having partial skeletons such as lactones, lactams, saltons, spiropyrans, esters, and amides, in which these partial skeletons rapidly open or cleave when in contact with an electron-accepting compound, are particularly preferred.

[0121] Examples of such acid-based colorants include 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide (referred to as "crystal violet lactone"), 3,3-bis(4-dimethylaminophenyl)phthalide, 3-(4-dimethylaminophenyl)-3-(4-diethylamino-2-methylphenyl)-6-dimethylaminophthalide, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylindole-3-yl)phthalide, and 3-(4-dimethylaminophenyl)-3-(2-methylaminophenyl)-6-dimethylaminophthalide. Chilindole-3-yl)phthalide, 3,3-bis(1,2-dimethylindole-3-yl)-5-dimethylaminophthalide, 3,3-bis(1,2-dimethylindole-3-yl)-6-dimethylaminophthalide, 3,3-bis(9-ethylcarbazole-3-yl)-6-dimethylaminophthalide, 3,3-bis(2-phenylindole-3-yl)-6-dimethylaminophthalide, 3-(4-dimethylaminophenyl)-3-(1-methylpyrrole-3-yl)-6-dimethylaminophthalide,

[0122] 3,3-bis[1,1-bis(4-dimethylaminophenyl)ethylene-2-yl]-4,5,6,7-tetrachlorophthalide, 3,3-bis[1,1-bis(4-pyrrolidinophenyl)ethylene-2-yl]-4,5,6,7-tetrabromophthalide, 3,3-bis[1-(4-dimethylaminophenyl)-1-(4-methoxyphenyl)ethylene-2-yl]-4,5,6,7-tetrachlorophthalide, 3,3-bis[1-(4-pyrrolidinophenyl)-1-(4-methoxyphenyl)ethylene-2-yl]-4,5,6,7-tetrachlorophthalide, 3-[1,1-di(1-ethyl-2-methylin Phthalides such as dole-3-yl)ethylene-2-yl]-3-(4-diethylaminophenyl)phthalide, 3-[1,1-di(1-ethyl-2-methylindole-3-yl)ethylene-2-yl]-3-(4-N-ethyl-N-phenylaminophenyl)phthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindole-3-yl)phthalide, 3,3-bis(1-n-octyl-2-methylindole-3-yl)phthalide, 3-(2-methyl-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindole-3-yl)phthalide,

[0123] 4,4-Bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leucoauramine, N-2,4,5-trichlorophenylleucoauramine, Rhodamine-B-anilinolactam, Rhodamine-(4-nitroanilino)lactam, Rhodamine-B-(4-chloroanilino)lactam, 3,7-bis(diethylamino)-10-benzoylphenoxazine, Benzoylleucomethylene blue, 4-nitrobenzoylmethylene blue,

[0124] 3,6-dimethoxyfluorane, 3-dimethylamino-7-methoxyfluorane, 3-diethylamino-6-methoxyfluorane, 3-diethylamino-7-methoxyfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-N-cyclohexyl-Nn-butylamino-7-methylfluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7-di-n-hexylaminofluorane, 3-diethylamino-7-anilinofluorane, 3- Diethylamino-7-(2'-fluorophenylamino)fluorane, 3-diethylamino-7-(2'-chlorophenylamino)fluorane, 3-diethylamino-7-(3'-chlorophenylamino)fluorane, 3-diethylamino-7-(2',3'-dichlorophenylamino)fluorane, 3-diethylamino-7-(3'-trifluoromethylphenylamino)fluorane, 3-di-n-butylamino-7-(2'-fluorophenylamino)fluorane, 3-di-n-butylamino-7-(2'-chlorophenylamino)fluorane, 3-N-isopentyl-N-ethylamino-7-(2'-chlorophenylamino)fluorane,

[0125] 3-Nn-hexyl-N-ethylamino-7-(2'-chlorophenylamino)fluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-di-n-butylamino-6-chloro-7-anilinofluorane, 3-diethylamino-6-methoxy-7-anilinofluorane, 3-di-n-butylamino-6-ethoxy-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3-morpholino- 6-methyl-7-anilinofluorane, 3-dimethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di-n-butylamino-6-methyl-7-anilinofluorane, 3-di-n-pentylamino-6-methyl-7-anilinofluorane, 3-N-ethyl-N-methylamino-6-methyl-7-anilinofluorane, 3-Nn-propyl-N-methylamino-6-methyl-7-anilinofluorane, 3-Nn-propyl-N-ethyl Luamino-6-methyl-7-anilinofluorane, 3-Nn-butyl-N-methylamino-6-methyl-7-anilinofluorane, 3-Nn-butyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isopentyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-Nn-hexyl-N-methyl Mino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-propylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-butylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-hexylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-octylamino-6-methyl-7-anilinofluorane,

[0126] 3-N-(2'-methoxyethyl)-N-methylamino-6-methyl-7-anilinofluorane, 3-N-(2'-methoxyethyl)-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-(2'-methoxyethyl)-N-isobutylamino-6-methyl-7-anilinofluorane, 3-N-(2'-ethoxyethyl)-N-methylamino-6-methyl-7-anilinofluorane, 3-N-(2'-ethoxyethyl)-N-ethylamino-6-methyl-7 -Anilinofluorane, 3-N-(3'-methoxypropyl)-N-methylamino-6-methyl-7-anilinofluorane, 3-N-(3'-methoxypropyl)-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-(3'-ethoxypropyl)-N-methylamino-6-methyl-7-anilinofluorane, 3-N-(3'-ethoxypropyl)-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-(2'-tetrahydrofurfuryl)- N-ethylamino-6-methyl-7-anilinofluorane, 3-N-(4'-methylphenyl)-N-ethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-ethyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-(3'-methylphenylamino)fluorane, 3-diethylamino-6-methyl-7-(2',6'-dimethylphenylamino)fluorane, 3-di-n-butylamino-6-methyl-7-(2',6'-dimethyl Fluoranes such as fluoranylamino)fluorane, 3-di-n-butylamino-7-(2',6'-dimethylphenylamino)fluorane, 2,2-bis[4'-(3-N-cyclohexyl-N-methylamino-6-methylfluorane)-7-ylaminophenyl]propane, 3-[4'-(4-phenylaminophenyl)aminophenyl]amino-6-methyl-7-chlorofluorane, 3-[4'-(dimethylaminophenyl)]amino-5,7-dimethylfluorane, etc.

[0127] 3-(2-methyl-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-n-propoxycarbonylamino-4-di-n-propylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-methylamino-4-di-n-propylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-methyl-4-di-n-hexylaminophenyl)-3-(1-n-octyl -2-methylindole-3-yl)-4,7-diazaphthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3,3-bis(1-n-octyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-octyl-2-methylindole-3-yl)-4 or 7-azaphthalide, 3-(2 -Ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4 or 7-azaphthalide, 3-(2-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4 or 7-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-phenylindole-3-yl)-4 or 7-azaphthalide, 3-(2-butoxy-4-diethylaminophenyl)-3-(1-ethyl-2-phenylindole-3 Phthalides such as -yl)-4 or 7-azaphthalide, 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxybenzo)spiropyran, 3-propyl-spiro-dibenzopyran-3,6-bis(dimethylamino)fluoren-9-spiro-3'-(6'-dimethylamino)phthalide, 3,6-bis(diethylamino)fluoren-9-spiro-3'-(6'-dimethylamino)phthalide,

[0128] Other examples include 2'-anilino-6'-(N-ethyl-N-isopentyl)amino-3'-methylspiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one, 2'-anilino-6'-(N-ethyl-N-(4-methylphenyl))amino-3'-methylspiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one, 3'-N,N-dibenzyloamino-6'-N,N-diethylaminospiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one, and 2'-(N-methyl-N-phenyl)amino-6'-(N-ethyl-N-(4-methylphenyl))aminospiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one.

[0129] In particular, the colorant used in this disclosure is preferably at least one compound selected from the group consisting of spiropyran compounds, spirooxazine compounds, spirolactone compounds, and spirolactam compounds, from the viewpoint of color development. From the viewpoint of visibility, the hue of the pigment after color development is preferably green, blue, or black.

[0130] Furthermore, the above-mentioned acid colorant is preferably a leuco dye from the viewpoint of color development and visibility of the exposed area. The above-mentioned leuco dye is not particularly limited as long as it has a leuco structure, but it is preferable that it has a spiro structure, and more preferably that it has a spirolactone ring structure. Furthermore, the leuco dye is preferably a leuco dye having a phthalide structure or a fluorane structure, from the viewpoint of color development and visibility of the exposed area. Furthermore, the leuco dye having the phthalide structure or fluorane structure described above is preferably a compound represented by any of the following formulas (Le-1) to (Le-3), and more preferably a compound represented by the following formula (Le-2), from the viewpoint of color development and visibility of the exposed area.

[0131] [ka]

[0132] In formulas (Le-1) to (Le-3), ERG each independently represents an electron-donating group, X1 to X4 each independently represents a hydrogen atom, a halogen atom, or a dialkylanilino group, and X5 to X 10 Each of the following independently represents a hydrogen atom, a halogen atom, or a monovalent organic group; Y1 and Y2 independently represent C or N; if Y1 is N, X1 is absent; if Y2 is N, X4 is absent; Ra1 represents a hydrogen atom, an alkyl group, or an alkoxy group; and Rb1 to Rb4 independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group.

[0133] In the ERG of formulas (Le-1) to (Le-3), the electron-donating group is preferably an amino group, alkylamino group, arylamino group, heteroarylamino group, dialkylamino group, monoalkylmonoarylamino group, monoalkylmonoheteroarylamino group, diarylamino group, diheteroarylamino group, monoarylmonoheteroarylamino group, alkoxy group, allyloxy group, heteroaryloxy group, or alkyl group, more preferably an amino group, alkylamino group, arylamino group, heteroarylamino group, dialkylamino group, monoalkylmonoarylamino group, monoalkylmonoheteroarylamino group, diarylamino group, diheteroarylamino group, monoarylmonoheteroarylamino group, alkoxy group, or allyloxy group, even more preferably a monoalkylmonoarylamino group, diarylamino group, diheteroarylamino group, or monoarylmonoheteroarylamino group, and particularly preferably a monoalkylmonoarylamino group. Furthermore, as the electron-donating group in the above ERG, from the viewpoint of color development and visibility of the exposed area, it is preferable that it is a disubstituted amino group having an aryl group having a substituent at least one ortho position or a heteroaryl group having a substituent at least one ortho position, more preferably a disubstituted amino group having a substituent at least one ortho position and a phenyl group having an electron-donating group at the para position, even more preferably an amino group having a phenyl group having a substituent at least one ortho position and an aryl group or heteroaryl group having an electron-donating group at the para position, and particularly preferably an amino group having a phenyl group having a substituent at least one ortho position and an aryl group having an electron-donating group or a heteroaryl group having an electron-donating group at the para position. In this disclosure, the ortho position in an aryl group or heteroaryl group other than a phenyl group refers to the bond position adjacent to position 1 (for example, position 2) when the bond position to another structure of the aryl group or heteroaryl group is defined as position 1. Furthermore, as electron-donating groups of the aryl or heteroaryl groups, from the viewpoint of color development and visibility of the exposed area, amino groups, alkylamino groups, arylamino groups, heteroarylamino groups, dialkylamino groups, monoalkylmonoarylamino groups, monoalkylmonoheteroarylamino groups, diarylamino groups, diheteroarylamino groups, monoarylmonoheteroarylamino groups, alkoxy groups, allyloxy groups, heteroaryloxy groups, or alkyl groups are preferred, alkoxy groups, allyloxy groups, heteroaryloxy groups, or alkyl groups are more preferred, and alkoxy groups are even more preferred.

[0134] In formulas (Le-1) to (Le-3), X1 to X4 are each independently preferably hydrogen atoms or chlorine atoms, and more preferably hydrogen atoms, from the viewpoint of color development and visibility of the exposed area. X5~X in equation (Le-2) or equation (Le-3) 10Each of these groups is preferably, from the viewpoint of color development and visibility of the exposed area, a hydrogen atom, halogen atom, alkyl group, aryl group, amino group, alkylamino group, arylamino group, heteroarylamino group, dialkylamino group, monoalkylmonoarylamino group, monoalkylmonoheteroarylamino group, diarylamino group, diheteroarylamino group, monoarylmonoheteroarylamino group, hydroxyl group, alkoxy group, allyloxy group, heteroallyloxy group, acyl group, alkoxycarbonyl group, allyloxycarbonyl group, heteroallyloxycarbonyl group, or cyano group, more preferably a hydrogen atom, halogen atom, alkyl group, aryl group, alkoxy group, or allyloxy group, even more preferably a hydrogen atom, halogen atom, alkyl group, or aryl group, and particularly preferably a hydrogen atom. In formulas (Le-1) to (Le-3), Y1 and Y2 are preferably C for at least one of them, and more preferably both Y1 and Y2 are C, from the viewpoint of color development and visibility of the exposed area. In formulas (Le-1) to (Le-3), Ra1 is preferably an alkyl group or an alkoxy group, more preferably an alkoxy group, and even more preferably a methoxy group, from the viewpoint of color development and visibility of the exposed area. In formulas (Le-1) to (Le-3), Rb1 to Rb4 are each independently preferably hydrogen atoms or alkyl groups, more preferably alkyl groups, and even more preferably methyl groups, from the viewpoint of color development and visibility of the exposed area.

[0135] Furthermore, the leuco dye having the phthalide structure or fluorane structure described above is more preferably a compound represented by any of the following formulas (Le-4) to (Le-6), and even more preferably a compound represented by the following formula (Le-5), from the viewpoint of color development and visibility of the exposed area.

[0136] [ka]

[0137] In formulas (Le-4) to (Le-6), ERG each independently represents an electron-donating group, X1 to X4 each independently represents a hydrogen atom, a halogen atom, or a dialkylanilino group, Y1 and Y2 each independently represent C or N, if Y1 is N, then X1 is absent, if Y2 is N, then X4 is absent, Ra1 represents a hydrogen atom, an alkyl group, or an alkoxy group, and Rb1 to Rb4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group.

[0138] In equations (Le-4) to (Le-6), ERG, X1 to X4, Y1, Y2, Ra1, and Rb1 to Rb4 are equivalent to ERG, X1 to X4, Y1, Y2, Ra1, and Rb1 to Rb4 in equations (Le-1) to (Le-3), and the same applies to the preferred embodiment.

[0139] Furthermore, the leuco dye having the phthalide structure or fluorane structure described above is more preferably a compound represented by any of the following formulas (Le-7) to (Le-9), and particularly preferably a compound represented by the following formula (Le-8), from the viewpoint of color development and visibility of the exposed area.

[0140] [ka]

[0141] In formulas (Le-7) to (Le-9), X1 to X4 each independently represent a hydrogen atom, a halogen atom, or a dialkylanilino group; Y1 and Y2 each independently represent C or N; if Y1 is N, X1 is absent; if Y2 is N, X4 is absent; Ra1 to Ra4 each independently represent a hydrogen atom, an alkyl group, or an alkoxy group; Rb1 to Rb4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group; and Rc1 and Rc2 each independently represent an aryl group or a heteroaryl group.

[0142] X1 to X4, Y1, and Y2 in Formulae (Le-7) to (Le-9) are synonymous with X1 to X4, Y1, and Y2 in Formulae (Le-1) to (Le-3), and the preferred embodiments are also the same. Ra1 to Ra4 in Formula (Le-7) or Formula (Le-9) are each independently preferably an alkyl group or an alkoxy group, more preferably an alkoxy group, and even more preferably a methoxy group, from the viewpoints of coloring property and visibility of the exposed portion. Rb1 to Rb4 in Formulae (Le-7) to (Le-9) are each independently preferably an aryl group substituted with a hydrogen atom, an alkyl group, or an alkoxy group, more preferably an alkyl group, and even more preferably a methyl group, from the viewpoints of coloring property and visibility of the exposed portion. Rc1 and Rc2 in Formula (Le-8) are each independently preferably a phenyl group or an alkylphenyl group, more preferably a phenyl group, from the viewpoints of coloring property and visibility of the exposed portion. Further, Rc1 and Rc2 in Formula (Le-8) are each independently preferably an aryl group having a substituent at at least one ortho-position or a heteroaryl group having a substituent at at least one ortho-position, more preferably an aryl group having a substituent at at least one ortho-position, even more preferably a phenyl group having a substituent at at least one ortho-position, and particularly preferably a phenyl group having a substituent at at least one ortho-position and an electron-donating group at the para-position. Examples of the above substituents in Rc1 and Rc2 include the substituents described below. Also, in Formula (Le-8), from the viewpoints of coloring property and visibility of the exposed portion, it is preferable that X1 to X4 are hydrogen atoms and Y1 and Y2 are C. Furthermore, in Formula (Le-8), from the viewpoints of coloring property and visibility of the exposed portion, it is preferable that Rb1 and Rb2 are each independently an aryl group substituted with an alkyl group or an alkoxy group. Furthermore, in formula (Le-8), from the viewpoint of color development and visibility of the exposed area, it is preferable that Rb1 and Rb2 are each independently an aryl group or a heteroaryl group, more preferably an aryl group, even more preferably an aryl group having an electron-donating group, and particularly preferably a phenyl group having an electron-donating group at the para position. Furthermore, the electron-donating groups in Rb1, Rb2, Rc1, and Rc2 are preferably amino groups, alkylamino groups, arylamino groups, heteroarylamino groups, dialkylamino groups, monoalkylmonoarylamino groups, monoalkylmonoheteroarylamino groups, diarylamino groups, diheteroarylamino groups, monoarylmonoheteroarylamino groups, alkoxy groups, allyloxy groups, heteroaryloxy groups, or alkyl groups, more preferably alkoxy groups, allyloxy groups, heteroaryloxy groups, or alkyl groups, and even more preferably alkoxy groups.

[0143] Furthermore, as an acid colorant, it is preferable to include a compound represented by the following formula (Le-10) from the viewpoint of color development and visibility of the exposed area.

[0144] [ka]

[0145] In formula (Le-10), Ar1 independently represents an aryl group or a heteroaryl group, and Ar2 independently represents an aryl group having a substituent at least one ortho position, or a heteroaryl group having a substituent at least one ortho position.

[0146] In equation (Le-10), Ar1 is equivalent to Rb1 and Rb2 in equations (Le-7) to (Le-9), and the same applies to the preferred embodiment. In equation (Le-10), Ar2 is synonymous with Rc1 and Rc2 in equations (Le-7) to (Le-9), and the same applies to the preferred embodiment.

[0147] Furthermore, as an acid colorant, it is preferable to include a compound represented by the following formula (Le-11) from the viewpoint of color development and visibility of the exposed area.

[0148] [ka]

[0149] In formula (Le-11), ERG each independently represents an electron-donating group, n11 represents an integer from 1 to 5, X1 to X4 each independently represents a hydrogen atom, a halogen atom, or a dialkylanilino group, Y1 and Y2 each independently represent C or N, if Y1 is N, then X1 is absent, if Y2 is N, then X4 is absent, and Rb2 and Rb4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group.

[0150] In formula (Le-11), ERG, X1-X4, Y1, Y2, Rb2, and Rb4 are equivalent to ERG, X1-X4, Y1, Y2, Rb2, and Rb4 in formulas (Le-1) to (Le-3), respectively, and the same applies to the preferred embodiment. In equation (Le-11), n11 is preferably an integer between 1 and 3, and more preferably 1 or 2.

[0151] The alkyl groups in formulas (Le-1) to (Le-9) and (Le-11) may be linear, branched, or have a ring structure. Furthermore, the number of carbon atoms in the alkyl group in formulas (Le-1) to (Le-9) and formula (Le-11) is preferably 1 to 20, more preferably 1 to 8, even more preferably 1 to 4, and particularly preferably 1 or 2. In formulas (Le-1) to (Le-11), the number of carbon atoms in the aryl group is preferably 6 to 20, more preferably 6 to 10, and even more preferably 6 to 8. Specific examples of aryl groups in formulas (Le-1) to (Le-11) include phenyl, naphthyl, anthracenyl, and phenantrenyl groups, which may have substituents. Specific examples of heteroaryl groups in formulas (Le-1) to (Le-11) include furyl groups, pyridyl groups, pyrimidyl groups, pyrazoyl groups, and thiophenyl groups, which may have substituents.

[0152] Furthermore, each of the monovalent organic groups, alkyl groups, aryl groups, heteroaryl groups, dialkylanilino groups, alkylamino groups, and alkoxy groups in formulas (Le-1) to (Le-10) may have substituents. Examples of substituents include alkyl groups, aryl groups, heteroaryl groups, halogen atoms, amino groups, alkylamino groups, arylamino groups, heteroarylamino groups, dialkylamino groups, monoalkylmonoarylamino groups, monoalkylmonoheteroarylamino groups, diarylamino groups, diheteroarylamino groups, monoarylmonoheteroarylamino groups, hydroxyl groups, alkoxy groups, allyloxy groups, heteroallyloxy groups, acyl groups, alkoxycarbonyl groups, allyloxycarbonyl groups, heteroallyloxycarbonyl groups, and cyano groups. These substituents may also be further substituted with other substituents.

[0153] The following compounds are examples of leuco dyes having the above-mentioned phthalide or fluorane structure that are preferably used. Note that Me represents a methyl group.

[0154] [ka]

[0155] [ka]

[0156]

change

[0157]

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[0158]

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[0159]

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[0160]

change

[0161] It is also possible to use commercially available colorants, such as ETAC, RED500, RED520, CVL, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, BLUE220, H-3035, BLUE203, ATP, H-1046, H-2114 (all manufactured by Fukui Yamada Chemical Industry Co., Ltd.), ORANGE-DCF, and Vermilio. Examples include n-DCF, PINK-DCF, RED-DCF, BLMB, CVL, GREEN-DCF, TH-107 (all manufactured by Hodogaya Chemical Co., Ltd.), ODB, ODB-2, ODB-4, ODB-250, ODB-BlackXV, Blue-63, Blue-502, GN-169, GN-2, Green-118, Red-40, Red-8 (all manufactured by Yamamoto Kasei Co., Ltd.), and Crystal Violet Lactone (manufactured by Tokyo Chemical Industry Co., Ltd.). Among these commercially available products, ETAC, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, H-3035, ATP, H-1046, H-2114, GREEN-DCF, Blue-63, GN-169, and Crystal Violet Lactone are preferred because the resulting film has good visible light absorption.

[0162] These colorants may be used individually or in combination of two or more components. The colorant content is preferably 0.5 to 10% by mass, and more preferably 1 to 5% by mass, relative to the total mass of the image recording layer.

[0163] The image recording layer 46 may further contain other compounds not mentioned above, if necessary. Other compounds include colorants, calcining agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic fine particles, and low molecular weight hydrophilic compounds, as disclosed in paragraphs

[0181] to

[0190] of Japanese Patent Publication No. 2009-255434. As a polymerization inhibitor, for example, known polymerization inhibitors such as phenothiazines can be used. Other compounds include hydrophobic precursors (fine particles that can convert the image recording layer to hydrophobic when heat is applied), low molecular weight hydrophilic compounds, lipophilic agents (e.g., phosphonium compounds, nitrogen-containing low molecular weight compounds, ammonium group-containing polymers), and chain transfer agents, as disclosed in paragraphs

[0191] to

[0217] of Japanese Patent Application Publication No. 2012-187907.

[0164] [Other layers] The lithographic printing plate master of the present invention may include layers other than the lithographic printing plate support 42, the undercoat layer 44, and the image recording layer 46 described above. For example, a protective layer may be included on the image recording layer 46 as needed to prevent scratches on the image recording layer 46, block oxygen, and prevent ablation during high-intensity laser exposure. Examples of materials used for the protective layer include those described in paragraphs

[0213] to

[0227] of Japanese Patent Publication No. 2009-255434 (water-soluble polymer compounds, inorganic layered compounds, etc.).

[0165] [Method for manufacturing lithographic printing plates] The method for manufacturing the lithographic printing plate of the present invention described above is preferably a manufacturing method that, following the method for manufacturing the lithographic printing plate support of the present invention described above, carries out the following steps in order. (Undercoat Formation Process) A process for forming an undercoat on a support for a lithographic printing plate. (Image recording layer formation process) A process of forming an image recording layer on an undercoat layer. The following details the procedures for each step.

[0166] <Primer layer formation process> The undercoat layer formation process is the process of forming an undercoat layer on a support for a lithographic printing plate. The method for manufacturing the undercoat layer is not particularly limited. For example, one method involves applying an undercoat layer forming solution containing a predetermined compound (e.g., a compound having a betaine structure) onto the anodic oxide film of a support for a lithographic printing plate. The coating solution for forming the undercoat layer preferably contains a solvent. Examples of solvents include water or organic solvents. Various known methods can be used to apply the primer layer forming solution. Examples include bar coater application, rotary application, spray application, curtain application, dip application, air knife application, blade application, and roll application. The amount of primer applied (solid content) is 0.1 to 100 mg / m². 2 It is preferable.

[0167] <Image recording layer formation process> The image recording layer formation process is the process of forming an image recording layer on top of the undercoat layer. The method for forming the image recording layer is not particularly limited. For example, one method is to apply a coating solution for forming the image recording layer, which contains predetermined components (such as the infrared absorber, polymerization initiator, and polymerizable compound mentioned above), onto a base coat layer. The coating solution for forming the image recording layer preferably contains a solvent. Examples of solvents include water or organic solvents. An example of a method for applying the coating solution for forming the image recording layer is the method exemplified as a method for applying the coating solution for forming the undercoat layer. The amount of coating (solid content) of the image recording layer varies depending on the application, but is generally 0.3 to 3.0 g / m². 2 It is preferable.

[0168] When a protective layer is provided on the image recording layer, the method of manufacturing the protective layer is not particularly limited. For example, a protective layer forming coating solution containing a predetermined component may be applied to the image recording layer.

[0169] Furthermore, although Figure 8 above describes an embodiment using the undercoat layer 44, as mentioned above, the undercoat layer does not necessarily have to be included in the lithographic printing plate. If a primer layer is not provided, the image recording layer may be formed after a hydrophilic treatment has been applied to the support for the lithographic printing plate. Known methods for hydrophilization treatment include those disclosed in paragraphs

[0109] to

[0114] of Japanese Patent Publication No. 2005-254638. In particular, hydrophilization treatment is preferably performed by immersion in an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate, or by applying a hydrophilic vinyl polymer or hydrophilic compound to form a hydrophilic undercoat layer. Hydrophilization treatment with aqueous solutions of alkali metal silicates such as sodium silicate and potassium silicate can be carried out by the methods and procedures described in U.S. Patent No. 2,714,066 and U.S. Patent No. 3,181,461.

[0170] [Method of manufacturing a lithographic printing plate] Next, we will describe the method for manufacturing lithographic printing plates using lithographic printing plates. A method for manufacturing a lithographic printing plate typically includes an exposure step in which a lithographic printing plate is exposed in an image-like manner (image exposure) to form exposed and unexposed areas, and a step in which the unexposed areas of the image-like exposed lithographic printing plate are removed. More specifically, one embodiment of a method for manufacturing a lithographic printing plate includes an exposure step of exposing a lithographic printing plate to an image (image exposure) to form exposed and unexposed areas, and a removal step of removing the unexposed areas of the lithographic printing plate using a developer with a pH of 2 to 12. Another embodiment of a method for manufacturing a lithographic printing plate includes an exposure step of exposing a lithographic printing plate to image-like exposure (image exposure) to form exposed and unexposed areas, and an on-press development step of supplying at least one of printing ink and dampening water to remove the unexposed areas of the image-like exposed lithographic printing plate on a printing press. These aspects will be described in detail below.

[0171] A method for manufacturing a lithographic printing plate includes a step of exposing the lithographic printing plate master to an image (image exposure) (in particular, a step of image exposure using an infrared laser). Image exposure is performed, for example, by laser exposure through a transparent master image having a line image or a halftone image, or by laser light scanning using digital data. The wavelength of the light source is preferably 750 to 1400 nm. In the case of a light source that emits light with a wavelength of 750 to 1400 nm, an image recording layer containing an infrared absorber, which is a sensitizing dye that has absorption in this wavelength range, is preferably used. Light sources emitting light with wavelengths of 750 to 1400 nm include solid-state lasers and semiconductor lasers that emit infrared light. For infrared lasers, the output is preferably 100 mW or more, the exposure time per pixel is preferably 20 microseconds or less, and the irradiation energy is preferably 10 to 300 mJ / cm². 2 This is preferable. Furthermore, it is preferable to use a multi-beam laser device to shorten the exposure time. The exposure mechanism may be an internal drum type, an external drum type, or a flatbed type. Image exposure can be performed using conventional methods with a platesetter or the like. In the case of the on-press development method described later, the lithographic printing plate can be mounted on the printing press, and then the lithographic printing plate may be exposed on the printing press.

[0172] The exposed lithographic printing plate is developed using either a method that removes unexposed areas with a developer solution with a pH of 2 to 12 (developer solution treatment method), or a method that removes unexposed areas on the printing press using at least one of printing ink and dampening solution (on-press development method).

[0173] <Developer processing method> In the developing solution processing method, the exposed lithographic printing plate is treated with a developing solution with a pH of 2 to 14, and the image recording layer in the unexposed areas is removed to produce a lithographic printing plate. The preferred developer is one that contains a compound (specific compound) having at least one acid group selected from the group consisting of a phosphate group, a phosphonic acid group, and a phosphinic acid group, and one or more carboxyl groups, and has a pH of 5 to 10.

[0174] Methods of developing include, in the case of manual processing, a method in which a sponge or cotton ball is thoroughly soaked in developing solution and the entire lithographic printing plate is rubbed while processing, and then thoroughly dried after processing. In the case of immersion processing, for example, a method in which the lithographic printing plate is immersed in a tray or deep tank containing developing solution for about 60 seconds and agitated, and then thoroughly dried while rubbing the lithographic printing plate with cotton balls or a sponge.

[0175] For the developing process, it is preferable to use equipment with a simplified structure and simplified procedures. In conventional developing processes, the protective layer is removed in a pre-washing step, followed by development with an alkaline developer, then the alkali is removed in a post-washing step, gum treatment is performed in a gum-setting step, and finally drying is performed in a drying step. Furthermore, developing and gumming can be performed simultaneously with a single solution. As the gum, polymers are preferred, and water-soluble polymer compounds and surfactants are more preferred. Furthermore, it is preferable to perform the removal of the protective layer, development, and gum removal simultaneously with a single solution, without performing a pre-washing step. It is also preferable to remove excess developer using a squeeze roller after development and gum removal, and then dry the film.

[0176] This process may involve immersing the object in the developer solution once, or two or more times. Of these, immersion in the developer solution once or twice is preferred. Immersion can be achieved by passing the exposed lithographic printing plate through a developing solution tank, or by spraying the developing solution onto the surface of the exposed lithographic printing plate. Even if the film is immersed in the developer more than once, if the same developer is used, or if the developer is used in combination with a developer (fatigue solution) in which the components of the image recording layer have been dissolved or dispersed by the development process, this is referred to as a one-solution development process (one-solution processing).

[0177] Furthermore, it is preferable to use an abrasive material in the development process, and it is preferable to install an abrasive material such as a brush in the developing bath that removes the non-image portion of the image recording layer. The developing process can be carried out according to conventional methods, preferably at a temperature of 0 to 60°C, more preferably 15 to 40°C, by, for example, immersing the exposed lithographic printing plate in a developing solution and rubbing it with a brush, or by pumping the developing solution from an external tank, spraying it through a spray nozzle, and rubbing it with a brush. These developing processes can be carried out multiple times in succession. For example, the developing solution can be pumped from an external tank, sprayed through a spray nozzle, and rubbing it with a brush, and then the developing solution can be sprayed again from the nozzle and rubbing it with a brush. When developing using an automatic developing machine, the developing solution becomes fatigued due to the increased processing volume, so it is preferable to restore the processing capacity by using a replenishment solution or fresh developing solution.

[0178] The developing process in this disclosure can also utilize gum coaters and automatic developing machines that are conventionally known for PS plates (Presensitized Plates) and CTP (Computer-to-Plate). When using an automatic developing machine, any of the following methods can be applied: a method in which developing solution is pumped up from a developing solution tank or an external tank and sprayed through a spray nozzle; a method in which the printing plate is immersed and transported in a tank filled with developing solution using a liquid guide roll or the like; and a so-called disposable processing method in which substantially unused developing solution is supplied in the necessary amount for each plate. In any of these methods, a rubbing mechanism using brushes and mortons is more preferable. For example, commercially available automatic photo processors (Clean Out Unit C85 / C125, Clean-Out Unit+ C85 / 120, FCF 85V, FCF 125V, FCF News (manufactured by Glunz & Jensen)), as well as Azura CX85, Azura CX125, and Azura CX150 (manufactured by AGFA GRAPHICS) can be used. Alternatively, a device in which the laser exposure unit and the automatic photo processor unit are integrated into one unit can also be used.

[0179] <On-press development method> In the on-press development method, the exposed lithographic printing plate is supplied with printing ink and dampening solution on the printing press, thereby removing the image recording layer in the non-image areas and producing a lithographic printing plate. In other words, when a lithographic printing plate is exposed to image light and then mounted on a printing press without any developing solution treatment, or when the lithographic printing plate is mounted on a printing press, exposed to image light on the press, and then printed by supplying printing ink and dampening solution, in the early stages of printing, the unexposed image recording layer in the unexposed areas is dissolved or dispersed and removed by the supplied printing ink and / or dampening solution, exposing a hydrophilic surface in those areas. On the other hand, in the exposed areas, the image recording layer hardened by exposure forms an oil-based ink receiving area with a lipophilic surface. Initially, either printing ink or dampening solution may be supplied to the plate surface, but it is preferable to supply printing ink first in order to prevent the dampening solution from being contaminated by the removed image recording layer components. In this way, the lithographic printing plate is developed on the printing press and used as is for printing a large number of copies. In other words, one aspect of the printing method of the present invention is a printing method comprising an exposure step of exposing the lithographic printing plate in an image-like manner to form exposed and unexposed areas, and a printing step of supplying at least one of printing ink and dampening water to remove the unexposed areas of the image-like exposed lithographic printing plate on the printing press and performing printing.

[0180] In the method for manufacturing a lithographic printing plate from a lithographic printing plate according to the present invention, regardless of the development method, the entire surface of the lithographic printing plate may be heated before image exposure, during image exposure, or between image exposure and development processing, as necessary. [Examples]

[0181] The features of the present invention will be further described below with reference to examples and comparative examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted restrictively by the specific examples shown below.

[0182] [Manufacturing of supports for lithographic printing plates] A support for lithographic printing plates was manufactured by subjecting a 0.3mm thick aluminum plate (aluminum alloy plate) of material 1S to the following treatment. Water washing was performed between all treatment steps, and after water washing, the material was de-drained using a nip roller.

[0183] [Example 1] <First Alkaline Etching Treatment> An aluminum plate was etched by spraying it with a caustic soda aqueous solution containing 26% by mass of caustic soda and 6.5% by mass of aluminum ions at a temperature of 70°C. Afterward, it was rinsed with water by spraying. The amount of aluminum dissolved in the surface to be subsequently subjected to electrochemical roughening treatment was 5 g / m². 2 That was the case.

[0184] <First desmatt treatment using acidic aqueous solution> Next, a desmatt treatment was performed using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate and desmatt treatment was performed for 3 seconds. The acidic aqueous solution used for the desmatt treatment was a 150 g / L sulfuric acid solution. The temperature of the solution was 30°C.

[0185] <Electrochemical surface roughening treatment> Next, electrochemical surface roughening treatment was performed using an electrolyte solution with a hydrochloric acid concentration of 10 g / L, an aluminum ion concentration of 15 g / L, and a sulfuric acid concentration of 1.0 g / L, with alternating current. The electrolyte solution temperature was 15°C. The aluminum ion concentration was adjusted by adding aluminum chloride. The waveform of an alternating current is a sine wave with symmetrical positive and negative waveforms, with a frequency of 50 Hz, anode reaction time and cathode reaction time in one cycle of the alternating current at a ratio of 1:1, and current density at the peak current value of the alternating current waveform is 35 A / dm². 2 The amount of electric charge was 350 C / dm², which is the sum of the electric charges that the aluminum plate participates in the anode reaction. 2 The electrolytic treatment was carried out in 10 separate steps, with a 1-second pause between each step. A carbon electrode was used as the counter electrode for the aluminum plate. After that, a water rinsing treatment was performed.

[0186] <Second Alkaline Etching Treatment> An aluminum plate that had undergone electrochemical roughening treatment was etched by spraying it with a caustic soda aqueous solution containing 5% by mass of caustic soda and 0.5% by mass of aluminum ions at a temperature of 45°C. The amount of aluminum dissolved on the electrochemically roughened surface was 0.1 g / m². 2 That was the case. Afterwards, it was washed with water.

[0187] <Second desmatt treatment using acidic aqueous solution> Next, a desmatt treatment was performed using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate and desmatt treatment was performed for 3 seconds. The acidic aqueous solution used for the desmatt treatment had a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L. The temperature of the solution was 35°C.

[0188] <First stage: Anodizing treatment> The first stage of anodic oxidation was performed using a DC electrolytic anodic oxidation apparatus with the structure shown in Figure 9, with an electrolyte containing sulfuric acid. The sulfuric acid concentration in the electrolyte was 1 g / L, the electrolyte temperature was 40°C, and the current density was 20 A / dm². 2 The coating thickness was 100 μm. In the anodic oxidation processing apparatus 610 shown in Figure 9, the aluminum plate 616 is transported as indicated by the arrow in Figure 6. In the power supply tank 612 where the electrolyte 618 is stored, the aluminum plate 616 is charged positively by the power supply electrode 620. Then, in the power supply tank 612, the aluminum plate 616 is transported upward by the roller 622, its direction is changed downward by the nip roller 624, and then it is transported toward the electrolytic treatment tank 614 where the electrolyte 626 is stored, and its direction is changed horizontally by the roller 628. Next, the aluminum plate 616 is charged negatively by the electrolytic electrode 630, so that an anodic oxide film is formed on its surface, and the aluminum plate 616 that has left the electrolytic treatment tank 614 is transported to the next process. In the anodic oxidation treatment apparatus 610, a direction changing mechanism is formed by rollers 622, nip rollers 624, and 628, and the aluminum plate 616 is conveyed in a mountain shape and an inverted U shape by rollers 622, nip rollers 624, and 628 in the space between the power supply tank 612 and the electrolytic treatment tank 614. The power supply electrode 620 and the electrolytic electrode 630 are connected to a DC power supply 634. A tank wall 632 is positioned between the power supply tank 612 and the electrolytic treatment tank 614.

[0189] <Pore-wide processing (PW processing)> The anodized aluminum plate described above was immersed for 4 seconds in a caustic soda aqueous solution at a temperature of 35°C, with a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass, to perform a pore widening treatment. After that, it was rinsed with water using a spray.

[0190] <Second stage anodizing treatment (2nd AD)> The second stage of anodic oxidation was performed using a DC electrolytic anodic oxidation apparatus with the structure shown in Figure 9, employing an electrolyte containing sulfuric acid. The sulfuric acid concentration in the electrolyte was 1 g / L, the electrolyte temperature was 25°C, and the current density was 40 A / dm². 2 That was the case.

[0191] <Examples 2-22, Comparative Examples 1-6> A support for a lithographic printing plate was prepared by following the same procedure as in Example 1, except that the manufacturing conditions in Example 1 were changed as shown in Table 1. In Examples 19 and 20, the second stage of anodizing was performed using a DC electrolytic anodizing apparatus with the structure shown in Figure 9 and an electrolyte containing phosphoric acid. Subsequently, the third stage of anodizing was performed using a DC electrolytic anodizing apparatus with the structure shown in Figure 9 and an electrolyte containing sulfuric acid. In the second AD of Examples 19 and 20, the phosphoric acid concentration in the electrolyte was 100 g / L, the electrolyte temperature was 30°C, and the current density was 8 A / dm². 2 The processing times were as shown in Table 1. Furthermore, in the third AD of Examples 19 and 20, the sulfuric acid concentration in the electrolyte was 1 g / L, the electrolyte temperature was 40°C, and the current density was 35 A / dm². 2 The processing times were as shown in Table 1.

[0192] In Table 1, "First alkali etching (g / m²)" 2 The column ")" indicates the amount of aluminum dissolved in the first alkali etching (g / m²). 2 ) represents. In Table 1, the "Liquid Temperature (°C)" column under "Electrochemical Surface Roughening Treatment" represents the liquid temperature (°C) of the electrolyte used in the electrochemical surface roughening treatment. In Table 1, the "Number of Electrolysis Cycles" column under "Electrochemical Surface Roughening Treatment" indicates how many electrolytic treatments were performed with a 1-second pause between each. In Table 1, "Second Alkali Etching (g / m²)" 2 The column ")" indicates the amount of aluminum dissolved in the second alkali etching (g / m²). 2 ) represents. In Table 1, the "Immersion Time (seconds)" column under "PW Treatment" indicates how many seconds the anodized aluminum plate was immersed in the caustic soda solution during the PW treatment. In Table 1, the "Processing Time (seconds)" column in the "Second AD" section represents the processing time (seconds) for the second AD process. In Table 1, the "Processing Time (seconds)" column under the "Third AD" column represents the processing time (seconds) for the Third AD process.

[0193] [Table 1]

[0194] For the fabricated support plates for lithographic printing, the average value of the equivalent circle diameter of the cross-section of the protrusions, the density of the protrusions, and the surface area ratio ΔS were measured using the method described above. These results are shown in Table 3 below. Furthermore, for the fabricated aluminum support, the average diameter of the large-diameter pores on the surface of the anodized film, the average diameter of the small-diameter pores at the points where they connect, and the depths of the large-diameter and small-diameter pores were measured using the method described above. These results are shown in Table 3 below. For Examples 19 and 20, the "Average Diameter" and "Depth" in the "Large Diameter Hole" column represent the average diameter and depth at the surface of the anodic oxide film in the "Upper Hole," respectively, and the "Internal Diameter" column represents the maximum diameter in the upper hole. Also for Examples 19 and 20, the "Average Diameter" and "Depth" in the "Small Diameter Hole" column represent the average diameter and depth at the point where the "Lower Hole" communicates with the upper hole, respectively.

[0195] A primer layer was formed on the anodic oxide film surface of each lithographic printing plate support prepared as described above using one of the primer layer coating liquids 1 to 2 described later. An image recording layer was then formed on the formed primer layer using one of the image recording layer coating liquids 1 to 3 described later to manufacture a lithographic printing plate master. The combinations of primer coating solution and image recording layer coating solution used are shown in Table 2 below. As shown in Table 2 below, in the case of formulations B to C, a protective layer was formed on the image recording layer using an additional protective layer coating solution. The formulations used in each example and comparative example are shown in Table 3 below. The "Undercoat Coating Liquid" column in Table 2 indicates the type of undercoat coating liquid used, with "1" representing undercoat coating liquid 1. The "Image Recording Layer Coating Solution" column in Table 2 indicates the type of image recording layer coating solution used, where "1" represents image recording layer coating solution 1, "2" represents image recording layer coating solution 2, and "3" represents image recording layer coating solution 3. The "Protective Coating Solution" column in Table 2 indicates the type of protective coating solution used. "1" represents protective coating solution 1, "2" represents protective coating solution 2, and "-" indicates that no protective coating solution was used. The formation procedure for each layer will be described in detail later.

[0196] [Table 2]

[0197] [Formation of the undercoat layer] Apply the undercoat coating liquid 1 to the anodic oxide film surface of each lithographic printing plate support prepared above, at a dry coating rate of 0.1 g / m². 2 The coat was applied in this manner to form a base coat layer.

[0198] (Primer coating liquid 1) The following components were mixed to prepare primer coating solution 1. ·Compound for undercoat layer (P-1 below, 11% by mass aqueous solution): 0.10502 parts by mass Sodium gluconate: 0.07000 parts by mass • Surfactant (Emarex 710, manufactured by Nippon Emulsion Co., Ltd.): 0.00159 parts by mass • Preservative (Biohope L, manufactured by K.I. Chemicals Co., Ltd.): 0.00149 parts by mass ·Water: 2.87190 parts by mass

[0199] P-1 (see structural formula below)

[0200] [ka]

[0201] [Formation of the image recording layer] Regarding the image recording layer coating liquid 1, the image recording layer coating liquid 1 is applied in a bar onto the undercoat layer of the support for lithographic printing plates that has an undercoat layer formed on it, and then dried in an oven at 50°C for 60 seconds, resulting in a dry coating amount of 0.9 g / m². 2 An image recording layer was formed, and a lithographic printing plate was obtained. Furthermore, regarding the image recording layer coating liquids 2-3, one of the image recording layer coating liquids 2-3 is applied in a bar onto the undercoat layer of the lithographic printing plate support, which has an undercoat layer formed on it, and then it is oven-dried at 120°C for 40 seconds until the dry coating amount is 1.0 g / m². 2 An image recording layer was formed, and a lithographic printing plate was obtained.

[0202] (Image recording layer coating solution 1) The following components were mixed to prepare image recording layer coating solution 1. • Polymer dispersion: 0.675 parts by mass Hydroxypropyl methylcellulose: 0.400 parts by mass • Monomer 1: 0.036 parts by mass • Monomer 2: 0.115 parts by mass • Monomer 3: 0.087 parts by mass ·IR (infrared) dye: 0.028 parts by mass • Surfactant: 0.045 parts by mass • Iodonium salt 1:0.073 parts by mass • Iodonium salt 2: 0.053 parts by mass ·Leuco dye: 0.040 parts by mass Phenothiazine: 0.005 parts by mass • 1-Propanol: 2.6 parts by mass 2-Butanone: 3.5 parts by mass • 1-Methoxy-2-propanol: 0.92 parts by mass • δ-Butyrolactone: 0.10 parts by mass ·Water: 1.16 parts by mass

[0203] Polymer dispersion: The polymer dispersion was prepared according to Example 10 of EP1,765,593. The solvent was n-propanol / water in a mass ratio of 80:20, and it was used as a dispersion with a solid content concentration of 23.5% by mass.

[0204] Hydroxypropyl methylcellulose was used as an aqueous solution with a solid content concentration of 5%. 30% of the OH groups in the hydroxypropyl methylcellulose were methoxylated, and 10% were hydroxypropoxylated. Furthermore, the viscosity of an aqueous solution with a solid content concentration of 2% by mass was 5 mPa-sec at 20°C.

[0205] Monomer 1

[0206] [ka]

[0207] Monomer 2

[0208] [ka]

[0209] Monomer 3

[0210] [ka]

[0211] IR dye

[0212] [ka]

[0213] Surfactant: Used as a 25% by mass solution of BYK® 302 from Byk Chemie in 1-methoxy-2-propanol.

[0214] Iodonium salt 1

[0215] [ka]

[0216] Iodonium salt 2

[0217] [ka]

[0218] Leuco dyes

[0219] [ka]

[0220] Phenothiazine

[0221] [ka]

[0222] (Image recording layer coating solution 2) The following components were mixed to prepare image recording layer coating solution 2. • Infrared absorber (IR-2): 0.0400 parts by mass • Colorant (S-22): 0.0200 parts by mass • Colorant (S-16): 0.0200 parts by mass • Electron-accepting polymerization initiator (Int-1): 0.1090 parts by mass • Electron-donating polymerization initiator (TPB): 0.0250 parts by mass • Polymerizable compound (see M-4 below): 0.4714 parts by mass Anionic surfactant (A-1): 0.0400 parts by mass • Fluorine-based surfactant (W-1): 0.0042 parts by mass 2-Butanone: 4.3551 parts by mass • 1-Methoxy-2-propanol: 3.9260 parts by mass Methanol: 2.6947 parts by mass • Polymer particles R: 2.3256 parts by mass

[0223] [ka]

[0224] [ka]

[0225] [ka]

[0226] [ka]

[0227] The HOMO energy level of the electron-accepting polymerization initiator (Int-1) was -6.70 eV. The LUMO energy level of the electron-accepting polymerization initiator (Int-1) was -3.08 eV.

[0228] [ka]

[0229] [ka]

[0230] [ka]

[0231] [Synthesis method for polymerizable compounds (M-4)] A mixed solution of Takenate D-160N (polyisocyanate trimethylolpropane adduct, manufactured by Mitsui Chemicals, Inc., 4.7 parts by mass), Aronics M-403 (manufactured by Toagosei Co., Ltd., in an amount that results in a 1:1 ratio between the NCO value of Takenate D-160N and the hydroxyl value of Aronics M-403), t-butylbenzoquinone (0.02 parts by mass), and methyl ethyl ketone (11.5 parts by mass) was heated to 65°C. Neostan U-600 (bismuth-based polycondensation catalyst, manufactured by Nitto Kasei Co., Ltd., 0.11 parts by mass) was added to the reaction solution and heated at 65°C for 4 hours. The reaction solution was cooled to room temperature (25°C), and methyl ethyl ketone was added to synthesize a urethane acrylate (M-4) solution with a solid content of 50% by mass.

[0232] [Preparation of polymer particles R] -Preparation of oil phase components- 6.66 g of WANNATE® PM-200 (polyfunctional isocyanate compound: manufactured by Manka Chemical Co., Ltd.), 5.46 g of Takenate® D-116N (a 50% by mass ethyl acetate solution of an adduct of trimethylolpropane (TMP), m-xylylene diisocyanate (XDI), and polyethylene glycol monomethyl ether (EO90) (structure shown below): manufactured by Mitsui Chemicals, Inc.), 11.24 g of a 65% by mass ethyl acetate solution of SR399 (dipentaerythritol pentaacrylate: manufactured by Sartomer Co., Ltd.), 14.47 g of ethyl acetate, and 0.45 g of Pionin® A-41-C (manufactured by Takemoto Oil & Fat Co., Ltd.) were mixed and stirred at room temperature (25°C) for 15 minutes to obtain the oil phase component.

[0233] [ka]

[0234] -Preparation of aqueous phase components- 47.2g of distilled water was prepared as the aqueous phase component.

[0235] -Microcapsule Formation Process- The oil phase component was added to the aqueous phase component and mixed. The resulting mixture was then emulsified using a homogenizer at 12,000 rpm for 16 minutes to obtain an emulsion. 16.8 g of distilled water was added to the resulting emulsion, and the resulting liquid was stirred at room temperature for 180 minutes. Next, the stirred liquid was heated to 45°C and stirred for 5 hours while maintaining the liquid temperature at 45°C to remove ethyl acetate from the liquid. The solid content concentration was adjusted to 20% by mass with distilled water to obtain an aqueous dispersion of polymer particles R. The volume-average particle size of R was measured to be 165 nm using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.).

[0236] (Image recording layer coating solution 3) The following components were mixed to prepare image recording layer coating solution 3. • Infrared absorber (IR-1): 0.0120 parts by mass • Infrared absorber (IR-2): 0.0250 parts by mass • Colorant (S-22): 0.0200 parts by mass • Colorant (S-16): 0.0200 parts by mass • Electron-accepting polymerization initiator (Int-1): 0.1090 parts by mass • Electron-donating polymerization initiator (TPB): 0.0250 parts by mass ·Polymerizable compound (M-4): 0.4714 parts by mass Anionic surfactant (A-1): 0.0400 parts by mass • Fluorine-based surfactant (W-1): 0.0042 parts by mass 2-Butanone: 4.3551 parts by mass • 1-Methoxy-2-propanol: 3.6383 parts by mass Methanol: 2.6947 parts by mass • Polymer particles R: 2.6163 parts by mass

[0237] [ka]

[0238] [Formation of a protective layer] Protective layer coating liquid 1 or 2 is bar-coated onto the image recording layer of an aluminum support with an image recording layer formed on it, and then oven-dried at 120°C for 60 seconds until the dry coating amount is 0.80 g / m². 2 A protective layer was formed.

[0239] (Protective coating solution 1) The following components were mixed to prepare protective layer coating solution 1. • Inorganic layered compound dispersion (1) [see below]: 0.5625 parts by mass • Hydrophilic polymer (1) (20% aqueous solution): 0.0825 parts by mass

[0240] [ka]

[0241] • Metholose SM04 (methylcellulose, manufactured by Shin-Etsu Chemical Co., Ltd., degree of methoxy substitution = 1.8): 0.0125 parts by mass • Rapisol A-80 (anionic surfactant, manufactured by NOF Corporation, 80% aqueous solution): 0.007 parts by mass • Ion-exchanged water: 4.3355 parts by mass

[0242] The method for preparing the inorganic layered compound dispersion (1) used in the protective layer coating solution described above is shown below. -Preparation of inorganic layered compound dispersion (1)- 6.4 parts by mass of synthetic mica (Somasif ME-100, manufactured by Coop Chemical Co., Ltd.) was added to 193.6 parts by mass of deionized water, and the mixture was dispersed using a homogenizer until the average particle size (laser scattering method) reached 3 μm. The aspect ratio of the resulting dispersed particles was 100 or greater.

[0243] (Protective coating solution 2) The following components were mixed to prepare protective layer coating solution 2. • Inorganic layered compound dispersion (1) [above]: 0.5625 parts by mass • The above hydrophilic polymer (1) (20% aqueous solution): 0.0825 parts by mass • Metholose SM04 (methylcellulose, manufactured by Shin-Etsu Chemical Co., Ltd., degree of methoxy substitution = 1.8): 0.0250 parts by mass • Rapisol A-80 (anionic surfactant, manufactured by NOF Corporation, 80% aqueous solution): 0.007 parts by mass • Ion-exchanged water: 4.3300 parts by mass

[0244] [Evaluation Method] <Scratch resistance> Scratch resistance was evaluated using a surface texture measuring instrument, TRIBOGEAR TYPE:18LFW (manufactured by Shinto Kagaku Co., Ltd.). A 0.1 mm sapphire needle was used to evaluate the lithographic printing plate original manufactured as described above, at a rate of 10 g / m². 2 From 90g / m 2 Up to 5g / m 2 The lithographic printing plate was scanned at a scanning speed of 20 mm / s while varying the load in increments to generate scratches. The scratched lithographic printing plate was then developed and printed on the press, and the load at which scratches and stains occurred on the 100th sheet of paper was evaluated. 10:90g / m 2 No scratches or stains will occur even under heavy loads. 9:90g / m 2 Damage and stains occur due to the load. 8: 85g / m 2 Damage and stains occur due to the load. 7:75 or 80g / m² 2 Damage and stains occur due to the load. 6:65 or 70g / m² 2 Damage and stains occur due to the load. 5:55 or 60g / m² 2 Damage and stains occur due to the load. 4:45 or 50g / m² 2 Damage and stains occur due to the load. 3:35 or 40g / m² 2 Damage and stains occur due to the load. 2:25 or 30g / m² 2 Damage and stains occur due to the load. 1:20g / m 2 Scratches and stains occur under the following loads.

[0245] <Oil-based cleaner resistance> The obtained lithographic printing plates were exposed using a Fujifilm Luxel PLATESETTER T-6000III equipped with an infrared semiconductor laser, under the following conditions: external drum rotation speed of 1000 rpm, laser output of 70%, and resolution of 2400 dpi. The exposed images included both a solid image and a 50% halftone chart of a 20 μm dot FM (Frequency Modulation) screen. The obtained exposed lithographic printing plates were mounted on the plate cylinder of a Komori Corporation LITHRONE26 printing press without development. Using a dampening solution of Ecolity-2 (Fujifilm Corporation) / tap water = 2 / 98 (volume ratio) and Values-G(N) black ink (Dainippon Ink and Chemicals, Inc.), the dampening solution and ink were supplied using the LITHRONE26's standard automatic printing start method, and after on-press development, printing was performed on Tokubishi Art (76.5kg) paper at a printing speed of 10,000 sheets per hour. As the number of printed sheets increased, the image recording layer gradually wore down, causing the ink density on the printed material to decrease. The number of printed sheets at the point when the density of solid images began to decrease visually was defined as the reference number of printed sheets. Next, using the same method as above, except that a step was added to wipe the printing plate with a cleaner (Fujifilm Multi-Cleaner) every 5,000 prints, the number of printed sheets at which the density of the solid image began to decrease visually was determined. The obtained number of printed sheets was defined as the evaluation print count, and its value is shown in the table below.

[0246] In Table 3, the "Equivalent Circle Diameter" column represents the average equivalent circle diameter of the cross-section of the convexity at a position 0.5 μm higher than the average height of the convexity. In Table 3, "Density of protrusions (numbers / mm²)" 2 The column ")" indicates the density of protrusions (number of pieces / mm²) that have a height of 0.5 μm or more above the average height of the protrusions. 2 ) represents.

[0247] [Table 3]

[0248] As shown in Table 3 above, it was confirmed that the desired effect can be obtained with the support for lithographic printing plates of the present invention. A comparison of Examples 1-3 confirmed that the effect is superior when the average equivalent circle diameter is between 3.0 and 6.5 μm. A comparison of Examples 4-6 shows that the density of the protrusions is 4000-9000 pieces / mm². 2 In that case, it was confirmed that the effect was superior. Based on the results of Examples 12-15, the film thickness was 3.2 g / m². 2 In the above cases, it was confirmed that the effect was superior. From a comparison of Examples 2 and 16-18, it was confirmed that when the average diameter of micropores on the surface of the anodic oxide film is 25-40 nm, an excellent balance of scratch resistance and abrasion resistance is achieved. A comparison between Examples 9 and 10 shows that the amount of second alkaline etching was 0.20 g / m². 2 In the following cases, superior print durability was confirmed. [Explanation of Symbols]

[0249] ta Anode reaction time tc Cathode reaction time tp: Time taken for the current to rise from zero to its peak. Ia. Peak current on the anode cycle side. Ic Current at peak on the cathode cycle side 10 Support for lithographic printing plates 12 Aluminum plate 14A, 14B, 14C Anodized Coating 16A First protrusion 16B Second protrusion 16C Third protrusion 20,30 micropores 22 Large diameter hole 24 Small diameter hole 32 Upper hole 34 Lower hole 36 Small diameter upper hole 38 Large diameter upper hole 40 Planographic printing plate original plate 42 Support for lithographic printing plates 44. Primer layer 46 Image recording layers 50 Main electrolyzer 51 AC power supply 52 Radial Drum Roller 53a,53b Main pole 54 Electrolyte supply port 55 Electrolyte 56 Auxiliary anode 60 Auxiliary anode tank W Aluminum plate 610 Anodizing treatment apparatus 612 Power supply tank 614 Electrolytic treatment tank 616 Aluminum plate 618,626 Electrolyte 620 Power supply electrode 622,628 Laura 624 Nipple Roller 630 Electrolytic electrode 632 Tank wall 634 DC power supply

Claims

1. A support for a lithographic printing plate, comprising an aluminum plate and an anodized aluminum film disposed on the aluminum plate, The surface of the lithographic printing plate support on the anodic oxide film side has a plurality of protrusions, The average equivalent circle diameter of the cross-section of the protrusion at a position 0.5 μm higher than the average height of the protrusion is 3.0 to 10.0 μm. The density of the protrusions having a height of 0.5 μm or more above the average height of the aforementioned protrusions is 3,000 to 9,000 per mm². ２ A support for lithographic printing plates.

2. The support for a lithographic printing plate according to claim 1, wherein the average value of the equivalent circle diameter is 3.0 to 6.5 μm.

3. The aforementioned density is 4000 to 9000 particles / mm ２ A support for a lithographic printing plate according to claim 1 or 2.

4. The ratio of the density to the average value of the equivalent circle diameter is 500 (pieces / mm²). ２ A support for a lithographic printing plate according to claim 1 or 2, wherein the thickness is ) / μm or greater.

5. The amount of the anodic oxide film is 2.0 g / m². ２ The above is the support for a lithographic printing plate according to claim 1 or 2.

6. The amount of the anodic oxide film is 3.2 g / m². ２ The above is the support for a lithographic printing plate according to claim 1 or 2.

7. A support for a lithographic printing plate according to claim 1 or 2, wherein the surface area ratio ΔS calculated by the following formula (1) from the actual area Sx obtained by the approximate three-point method from three-dimensional data obtained by measuring a 25 μm × 25 μm area at 512 points on the surface of the anodic oxide film side using an atomic force microscope, and the geometrically measured area S0, is 20% or more. ΔS=(Sx-S0) / S0×100(%)...(1)

8. The aforementioned anodic oxide film has micropores, The micropore is composed of a large-diameter pore extending from the surface of the anodic oxide film to a depth of 10 to 1000 nm, and a small-diameter pore communicating with the bottom of the large-diameter pore and extending from the communication point to a depth of 20 to 2000 nm. The average diameter of the large-diameter pores on the surface of the anodic oxide film is 18 to 60 nm. The support for a lithographic printing plate according to claim 1 or 2, wherein the average diameter of the small-diameter holes at the communication position is 15 nm or less.

9. The aforementioned anodic oxide film has micropores, The micropore is composed of an upper pore portion extending in the depth direction from the surface of the anodic oxide film, and a lower pore portion communicating with the bottom of the upper pore portion and extending from the communication point to a depth of 20 to 2000 nm. The average diameter of the upper pores on the surface of the anodic oxide film is 18 to 60 nm. The maximum diameter of the upper hole is 200 nm or less. The average diameter of the lower hole at the communication position is 15 nm or less. The support for a lithographic printing plate according to claim 1 or 2, wherein the ratio of the maximum diameter of the upper pores to the average diameter of the upper pores on the surface of the anodic oxide film is 1.2 or more.

10. The density of the aforementioned micropores is 300 to 2000 particles / μm ２ The support for a lithographic printing plate according to claim 8.

11. A lithographic printing plate master comprising a support for a lithographic printing plate according to claim 1 or 2 and an image recording layer.

12. A lithographic printing plate according to claim 11, which is developed on-press.

13. A step of exposing the lithographic printing plate according to claim 11 to an image using an infrared laser, A method for manufacturing a lithographic printing plate, comprising the step of removing an unexposed portion of the image recording layer on a printing press using at least one selected from printing ink and dampening solution.

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