Lithographic printing plate precursor, method for producing lithographic printing plate, printing method, and method for producing aluminum support

Abstract

The present invention provides an original plate for a planographic printing plate that has excellent oil-based cleaner printing resistance when used as a planographic printing plate, a method for manufacturing a planographic printing plate, a printing method, and a method for manufacturing an aluminum support. This original plate for a planographic printing plate has an aluminum support and an image recording layer disposed over the aluminum support, the aluminum support including an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate, the image recording layer being disposed on the anodic oxide film side of the aluminum support, and the area ratio of protrusions having a height from the average surface of 0.80 μm or greater, found by measuring a 400×400 μm range of the surface of the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter, being 20% or less.

Description

[Technical Field]

[0001] The present invention relates to a lithographic printing plate precursor, a method for producing a lithographic printing plate, a printing method, and a method for producing an aluminum support. [Background technology]

[0002] It is known that the surface of an aluminum support used in a lithographic printing plate is grained (roughened) to impart an uneven texture to improve the smudge resistance and printing durability of the resulting lithographic printing plate. For example, Patent Document 1 describes a planographic printing plate precursor having an aluminum support and an image recording layer disposed on the aluminum support, wherein the aluminum support comprises an aluminum plate and an anodized aluminum film disposed on the aluminum plate, the image recording layer is disposed on the anodized film side of the aluminum support, and the density of recesses having a depth of 0.70 μm or more from the center line obtained by measuring an area of ​​400 μm × 400 μm on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter is 3000 / mm 2 The above-mentioned planographic printing plate precursor is described as follows. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 087516 Summary of the Invention [Problem to be solved by the invention]

[0004] When printing is performed using a lithographic printing plate obtained from a lithographic printing plate precursor, the plate may be washed with a cleaner to remove dirt during printing. Even after such a cleaning treatment, it is required that printing durability does not decrease. This performance is also referred to as oil-based cleaner printing durability. The present inventors have studied the lithographic printing plate precursor described in Patent Document 1 and have found that it has a problem of poor printing durability with an oil-based cleaner.

[0005] An object of the present invention is to provide a lithographic printing plate precursor that, when made into a lithographic printing plate, has excellent oil-based cleaner printing durability. Another object of the present invention is to provide a method for producing a lithographic printing plate, a printing method, and a method for producing an aluminum support. [Means for solving the problem]

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

[0007] (1) A lithographic printing plate precursor having an aluminum support and an image recording layer disposed on the aluminum support, the aluminum support includes an aluminum plate and an anodized aluminum coating disposed on the aluminum plate; an image-recording layer is disposed on the anodized film side of the aluminum support; A lithographic printing plate precursor, in which an area of ​​400 μm × 400 μm on the surface of the image recording layer side of an aluminum support is measured using a non-contact three-dimensional roughness meter, and the area ratio of convex portions having a height from the average surface of 0.80 μm or more is 20% or less. (2) The lithographic printing plate precursor according to (1), wherein the area ratio of the convex portions having a height from the average plane of 0.80 μm or more is 13% or less. (3) The lithographic printing plate precursor according to (1) or (2), wherein the area ratio of the convex portions having a height from the average plane of 0.80 μm or more is 10% or less. (4) The lithographic printing plate precursor according to any one of (1) to (3), wherein the area ratio of convex portions having a height from the average plane of 0.80 μm or more is 7% or less. (5) A lithographic printing plate precursor having an aluminum support and an image recording layer disposed on the aluminum support, the aluminum support includes an aluminum plate and an anodized aluminum coating disposed on the aluminum plate; an image-recording layer is disposed on the anodized film side of the aluminum support; The density of recesses having a depth of 0.40 μm or more from the average surface, measured within a 400 μm × 400 μm area on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter, is 4,000 / mm 2 This is the lithographic printing plate precursor. (6) The density of recesses having a depth of 0.40 μm or more from the average surface is 6000 / mm 2 The lithographic printing plate precursor according to (5) above. (7) The density of recesses having a depth of 0.40 μm or more from the average surface is 8000 / mm 2 The lithographic printing plate precursor according to (5) or (6), wherein (8) The lithographic printing plate precursor according to any one of (5) to (7), wherein the area ratio of convex portions having a height from the average surface of 0.80 μm or more, as measured within a 400 μm × 400 μm area on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter, is 20% or less. (9) The density of recesses having a depth of 0.20 μm or more from the average surface, measured within a 400 μm×400 μm area on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter, is 6,000 / mm 2 A lithographic printing plate precursor according to any one of (1) to (8) above. (10) The lithographic printing plate precursor according to any one of (1) to (9), wherein the surface area ratio ΔS calculated from the actual area Sx obtained by the approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points in an area of ​​25 μm × 25 μm on the surface of the aluminum support on the image recording layer side using an atomic force microscope and the geometrically measured area S0 using the formula (1) described below is 20% or more. (11) The lithographic printing plate precursor according to (10), which has a surface area ratio ΔS of 25% or more. (12) The lithographic printing plate precursor according to (10) or (11), which has a surface area ratio ΔS of 45% or more. (13) The area ratio of convex portions having a height of 0.80 μm or more from the average surface, as measured within a 400 μm × 400 μm area on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter, is 10% or less; The lithographic printing plate precursor according to (1), wherein the surface area ratio ΔS calculated from the actual area Sx obtained by the approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points in an area of ​​25 μm × 25 μm on the surface of the aluminum support on the image recording layer side using an atomic force microscope and the geometrically measured area S0 using the formula (1) described below is 20% or more. (14) The lithographic printing plate precursor according to (13), which has a surface area ratio of 45% or more. (15) The lithographic printing plate precursor according to (13), wherein the area ratio of the convex portions having a height from the average plane of 0.80 μm or more is 7% or less. (16) The lithographic printing plate precursor according to (13), wherein the area ratio of the protrusions having a height from the average plane of 0.80 μm or more is 7% or less and the surface area ratio is 45% or more. (17) The area ratio of convex portions having a height of 0.80 μm or more from the average surface, as measured within a 400 μm × 400 μm area on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter, is 10% or less; The density of recesses having a depth of 0.20 μm or more from the average surface, measured within a 400 μm × 400 μm area on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter, is 6,000 / mm 2 That's all, The lithographic printing plate precursor according to (1), wherein the surface area ratio ΔS calculated from the actual area Sx obtained by the approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points in an area of ​​25 μm × 25 μm on the surface of the aluminum support on the image recording layer side using an atomic force microscope and the geometrically measured area S0 using the formula (1) described below is 45% or more. (18) The lithographic printing plate precursor according to any one of (1) to (17), wherein the surface roughness Ra of the surface of the aluminum support on the image recording layer side measured using a contact surface roughness meter is 0.45 μm or less. (19) The anodic oxide film has micropores, the micropores are composed of large-diameter pores extending from the surface of the anodized film to a depth of 10 to 1,000 nm, and small-diameter pores communicating with the bottoms of the large-diameter pores and extending from the communicating positions to a depth of 20 to 2,000 nm; the average diameter of the large diameter pores on the surface of the anodized film is 15 to 60 nm; The lithographic printing plate precursor according to any one of (1) to (18), wherein the average diameter of the small diameter pores at the communicating positions is smaller than the average diameter of the large diameter pores. (20) An exposure step of imagewise exposing the lithographic printing plate precursor according to any one of (1) to (19) to form exposed areas and unexposed areas; a removing step of removing unexposed areas of the imagewise exposed lithographic printing plate precursor. (21) An exposure step of imagewise exposing the lithographic printing plate precursor according to any one of (1) to (19) to form exposed areas and unexposed areas; a printing step of supplying at least one of printing ink and dampening water to remove unexposed areas of the imagewise exposed lithographic printing plate precursor on a printing press, thereby carrying out printing. (22) A method for producing an aluminum support used in the lithographic printing plate precursor according to any one of (1) to (19), comprising the steps of: For aluminum plates, in a hydrochloric acid treatment solution that may contain sulfuric acid, the temperature of the hydrochloric acid treatment solution is 30°C or less, and the total amount of electricity is 400C / dm 2 and the peak current value of the AC current waveform is 80A / dm 2 The method includes a hydrochloric acid electrolysis step of subjecting an aluminum plate to AC electrolysis to produce a surface-roughened aluminum plate, When the hydrochloric acid treatment solution contains sulfuric acid, the ratio of the content of sulfuric acid to the content of hydrochloric acid is 0.1 or less. Method for producing an aluminum support. (23) After the hydrochloric acid electrolysis process, an anodizing treatment step of anodizing the roughened aluminum plate to form an aluminum anodized film on the aluminum plate; a pore widening treatment step in which the aluminum plate on which the anodized film has been formed is subjected to an etching treatment to enlarge the diameter of the micropores in the anodized film; The method for producing an aluminum support according to (22), which comprises the above in this order. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a lithographic printing plate precursor which, when made into a lithographic printing plate, has excellent oil-based cleaner printing durability. The present invention also provides a method for producing a lithographic printing plate, a printing method, and a method for producing an aluminum support. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of one embodiment of the lithographic printing plate precursor of the present invention. [Figure 2] FIG. 1 is a schematic cross-sectional view of one embodiment of an aluminum support. [Figure 3] 1 is a graph showing an example of an alternating current waveform used in electrochemical graining treatment in a method for producing an aluminum support. [Figure 4] FIG. 1 is a side view showing an example of a radial cell used in electrochemical graining treatment using alternating current in a method for producing an aluminum support. [Figure 5] FIG. 2 is a schematic cross-sectional view of another embodiment of an aluminum support. [Figure 6] FIG. 1 is a schematic view of an anodizing treatment apparatus used for anodizing treatment in the production of an aluminum support. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below. The following description of the components 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 expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, in this specification, when a group in a compound represented by a formula is not specified as substituted or unsubstituted, and the group can further have a substituent, the group encompasses not only unsubstituted groups but also substituted groups unless otherwise specified. For example, in a formula, if it is stated that "R represents an alkyl group, an aryl group, or a heterocyclic group," 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] A first embodiment of the lithographic printing plate precursor of the present invention is a lithographic printing plate precursor having an aluminum support and an image recording layer disposed on the aluminum support, wherein the aluminum support comprises an aluminum plate and an anodized aluminum film disposed on the aluminum plate, the image recording layer is disposed on the anodized film side of the aluminum support, and the density of recesses having a depth of 0.40 μm or more from the average surface, as measured within a 400 μm×400 μm area on the surface of the aluminum support on the image recording layer side, is 4,000 / mm 2 This is the planographic printing plate precursor. A second embodiment of the lithographic printing plate precursor of the present invention is a lithographic printing plate precursor having an aluminum support and an image recording layer disposed on the aluminum support, wherein the aluminum support comprises an aluminum plate and an anodized aluminum coating disposed on the aluminum plate, the image recording layer is disposed on the anodized coating side of the aluminum support, and the area ratio of convex portions having a height from the average surface of 0.80 μm or more, as measured by a non-contact three-dimensional roughness meter within a 400 μm × 400 μm area of ​​the surface of the aluminum support on the image recording layer side, is 20% or less. The two differ in that the density of recesses of a predetermined depth is specified in the first embodiment, whereas the area ratio of protrusions of a predetermined height is specified in the second embodiment. In the following, first, the density of recesses of a predetermined depth in the first embodiment and the area ratio of protrusions of a predetermined height in the second embodiment, which are features of each embodiment, will be described.

[0012] Density of recesses In a first embodiment of the lithographic printing plate precursor of the present invention, a density of recesses having a depth from the average surface of 0.40 μm or more (hereinafter also referred to as "first specific recesses") measured within a 400 μm × 400 μm area on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter is 4000 / mm 2 That's all. In particular, the density of the first specific recesses is 6000 pieces / mm 2 in terms of superior oil-based cleaner printing durability (hereinafter simply referred to as “superior effect of the present invention”). 2 More than 8000 pieces / mm 2 The upper limit of the density of the first specific recesses is not particularly limited, but it is preferably 20,000 pieces / mm 2 Preferably less than 16,000 pieces / mm 2 The following is more preferred:

[0013] In the present invention, the density of the first specific recesses refers to a value measured as follows. First, a non-contact three-dimensional roughness meter (VertScan, manufactured by Ryoka Systems Co., Ltd.) is used to scan an area of ​​400 μm × 400 μm on the surface of the aluminum support on the image recording layer side without contact at a resolution of 0.01 μm to obtain three-dimensional data. The VertScan device specifications and measurement conditions are as follows: (1) Equipment contents CCD camera: Sony HR-57 Objective lens: x10 Telescope tube: x1 Wavelength filter: 530 white (2) Measurement conditions Measurement mode: wave Field of view range: 400 μm x 400 μm Scan range: Start +6μm, Stop -10μm The obtained three-dimensional data was then subjected to image analysis using software (SX Viewer, manufactured by Ryoka Systems Co., Ltd.), and the number of recesses having a depth of 0.40 μm or more from the obtained average plane was determined by selecting "full interpolation" → "surface correction polynomial" → "quadratic" → "particle analysis." Note that the average plane refers to the plane located at a height obtained by averaging the height values ​​of all measurement data on the surface of the aluminum support on the image recording layer side within the measurement area (400 μm × 400 μm). Measurements were taken at five locations per sample, and the number of specified recesses was calculated at each location. The average value was then calculated and used to calculate the unit area (μm 2 ) and use this as the density of the first specified recesses.

[0014] [Protrusion area ratio] In a second embodiment of the lithographic printing plate precursor of the present invention, the area ratio of convex portions (hereinafter also referred to as "specific convex portions") having a height from the average surface of 0.80 μm or more, as measured within an area of ​​400 μm × 400 μm on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter, is 20% or less. In particular, in terms of achieving superior effects of the present invention, the area ratio of the specific convex portions is preferably 13% or less, more preferably 10% or less, even more preferably 8% or less, particularly preferably 7% or less, more particularly preferably less than 3%, and most preferably 2% or less. There is no particular lower limit for the area ratio of the specific convex portions, but it is preferably 0% or more, more preferably 0.2% or more.

[0015] In the present invention, the area ratio of the specific convex portions refers to a value measured as follows. First, a non-contact three-dimensional roughness meter (VertScan, manufactured by Ryoka Systems Co., Ltd.) is used to scan an area of ​​400 μm × 400 μm on the surface of the aluminum support on the image recording layer side without contact at a resolution of 0.01 μm to obtain three-dimensional data. The VertScan device specifications and measurement conditions are as follows: (1) Equipment contents CCD camera: Sony HR-57 Objective lens: x10 Telescope tube: x1 Wavelength filter: 530 white (2) Measurement conditions Measurement mode: wave Field of view range: 400 μm x 400 μm Scan range: Start +6μm, Stop -10μm Next, the obtained three-dimensional data is subjected to image analysis using software (SX Viewer, manufactured by Ryoka Systems Co., Ltd.), and convex portions having a depth of 0.80 μm or more from the obtained average surface are extracted, and the area ratio of the convex portions within an area of ​​400 μm x 400 μm is calculated. Measurement is carried out at five locations per sample, the area ratio of the specified convex portion is calculated at each location, and then the average value of these is calculated to be the area ratio of the specified convex portion.

[0016] In the first embodiment of the lithographic printing plate precursor of the present invention described above, the area ratio of the specific convex portions is not particularly limited, but is preferably 20% or less in terms of more excellent effects of the present invention. That is, in the first embodiment of the lithographic printing plate precursor of the present invention, the density of the first specific concave portions is 4000 / mm2, as measured by a non-contact three-dimensional roughness meter within a 400 μm×400 μm area on the surface of the aluminum support on the image recording layer side. 2 The area ratio of the specific convex portions may be equal to or greater than 20%. In the first embodiment of the lithographic printing plate precursor of the present invention, the area ratio of the specific convex portions is preferably 13% or less, more preferably 10% or less, even more preferably 8% or less, and particularly preferably 7% or less, in order to achieve better effects of the present invention. There is no particular lower limit for the area ratio of the specific convex portions, but it is preferably 0% or more, more preferably 0.3% or more.

[0017] In the second embodiment of the lithographic printing plate precursor of the present invention described above, the density of the first specific recesses is not particularly limited, but in terms of the effects of the present invention being more excellent, it is preferable that the density be 4000 / mm 2 That is, in the second embodiment of the lithographic printing plate precursor of the present invention, the area ratio of the specific convex portions is 20% or less, and the density of the first specific concave portions is 4000 / mm 2 It may be more than that. In the second embodiment of the lithographic printing plate precursor of the present invention, the density of the first specific recesses is set to 6000 / mm 2 More than 8000 pieces / mm 2 The upper limit of the density of the first specific recesses is not particularly limited, but it is preferably 20,000 pieces / mm 2 Preferably less than 16,000 pieces / mm 2 The following is more preferred:

[0018] The configuration of the lithographic printing plate precursor of the present invention will be described in more detail below, but unless otherwise specified, the configuration described below is related to both the first and second embodiments described above.

[0019] Density of recesses In the lithographic printing plate precursor of the present invention (first embodiment and second embodiment), the density of recesses having a depth of 0.20 μm or more from the average surface, as measured within an area of ​​400 μm × 400 μm on the surface of the aluminum support on the image recording layer side using a non-contact three-dimensional roughness meter (hereinafter also simply referred to as "second specific recesses"), is not particularly limited, but is preferably 3000 / mm 2 In most cases, the effect of the present invention is more excellent, and the number of particles per mm is 6000. 2 More than 8000 pieces / mm 2 The upper limit of the density of the second specific recesses is not particularly limited, but it is preferably 20,000 pieces / mm 2 Preferably less than 16,000 pieces / mm 2 The following is more preferred:

[0020] The method for measuring the second specific recesses is to first measure under the same conditions using a non-contact three-dimensional roughness meter (VertScan, manufactured by Ryoka Systems Co., Ltd.) as used to measure the density of the first specific recesses described above, and then perform image analysis of the obtained three-dimensional data using software (SX Viewer, manufactured by Ryoka Systems Co., Ltd.) to determine the number of recesses having a depth from the average surface of 0.20 μm or more. Measurements were taken at five locations per sample, and the number of specified recesses was calculated at each location. The average value was then calculated and used to calculate the unit area (μm2 ) and use this as the density of the second specified recesses.

[0021] [Surface area ratio ΔS] In the lithographic printing plate precursors of the present invention (first and second embodiments), a surface area ratio ΔS calculated from the actual area Sx determined by the approximate three-point method from three-dimensional data obtained by using an atomic force microscope to measure 512 × 512 points in a 25 μm × 25 μm area on the surface of the aluminum support on the image recording layer side and the geometrically measured area S0 according to the following formula (1) is preferably 20% or more, more preferably 25% or more, even more preferably 35% or more, and particularly preferably 45% or more, in order to achieve better effects of the present invention. There is no particular upper limit to the surface area ratio ΔS, but it is preferably 70% or less, more preferably 60% or less. ΔS=(Sx-S0) / S0×100(%) ···(1)

[0022] In the present invention, the surface area ratio ΔS refers to a value measured as follows. Specifically, a 1 cm square piece of aluminum support is cut and placed on a horizontal sample stage on a piezoelectric scanner. The cantilever approaches the sample surface and, once it reaches the region where atomic forces are active, scans in the X and Y directions, capturing the sample's unevenness via piezoelectric displacement in the Z direction. A piezoelectric scanner capable of scanning 150 μm in the X and Y directions and 10 μm in the Z direction is used. A cantilever with a resonant frequency of 130–200 kHz and a spring constant of 7–20 N / m (OMCL-AC200-TS, Olympus) is used, and measurements are performed in Dynamic Force Mode (DFM). Furthermore, the obtained 3D data is subjected to a least-squares approximation to correct for slight tilts in the sample and determine the reference plane. The measurement is performed at 512 x 512 points over a 25 x 25 μm area on the surface, with a resolution of 0.05 μm in the X direction, 1.9 μm in the Y direction, and 1 nm in the Z direction, at a scan speed of 18 μm / sec.

[0023] [Surface roughness Ra] In the lithographic printing plate precursor of the present invention (first and second embodiments), the surface roughness Ra obtained by measuring the surface of the aluminum support on the image recording layer side using a contact surface roughness meter is not particularly limited, but is often 0.50 μm or less, and from the viewpoint of better effects of the present invention, it is preferably 0.45 μm or less, more preferably 0.40 μm or less, and even more preferably 0.35 μm or less. The lower limit of the surface roughness Ra is not particularly limited, but is preferably 0.1 μm or more, more preferably 0.12 μm or more.

[0024] In the present invention, surface roughness Ra (arithmetic mean roughness Ra) is the value given by the following formula, expressed in μm units, when a section of measurement length L is extracted from a roughness curve measured with a stylus meter in the direction of the center line of the curve, and the roughness curve is expressed as Y=f(X), with the center line of this extracted section as the X axis and the axis perpendicular to it as the Y axis (determination of L and measurement of mean roughness are in accordance with JIS B 0601):

[0025]

number

[0026] In a preferred embodiment of the lithographic printing plate precursor of the present invention (first embodiment and second embodiment), the effect of the present invention is more excellent, in that the area ratio of the specific convex portions is 10% or less and the density of the second specific concave portions is 6000 / mm 2 or more, and the surface area ratio ΔS is 45% or more.

[0027] Other preferred embodiments of the lithographic printing plate precursor of the present invention (first and second embodiments) include a lithographic printing plate precursor in which the area ratio of the specific convex portions is 10% or less and the above surface area ratio ΔS is 20% or more, in terms of the effects of the present invention being more excellent. Other preferred embodiments of the lithographic printing plate precursor of the present invention (first and second embodiments) include a lithographic printing plate precursor in which the area ratio of the specific convex portions is 10% or less and the above surface area ratio ΔS is 45% or more, in terms of the effects of the present invention being more excellent. Other preferred embodiments of the lithographic printing plate precursor of the present invention (first and second embodiments) include a lithographic printing plate precursor in which the area ratio of the specific convex portions is 7% or less and the above surface area ratio ΔS is 20% or more, in terms of the effects of the present invention being more excellent. Other preferred embodiments of the lithographic printing plate precursor of the present invention (first and second embodiments) include a lithographic printing plate precursor in which the area ratio of the specific convex portions is 7% or less and the above surface area ratio ΔS is 45% or more, in terms of the effects of the present invention being more excellent.

[0028] In the present invention, in order to improve visibility, the surface of the aluminum support on the image recording layer side, i.e., the surface of the anodized film, is coated with L * a * b * Lightness L in the color system * The value is preferably 68 to 90, and more preferably 75 to 90. Also, L * a * b * a in color space * The value of b is preferably -4 to 4. * The value is preferably −4 to 4. where L * a * b * Color space L * , a * and b * The average value of five measurements is used as the color difference value.

[0029] FIG. 1 is a schematic cross-sectional view of one embodiment of the lithographic printing plate precursor of the present invention. The lithographic printing plate precursor 10 shown in Figure 1 has an aluminum support 12a and an image recording layer 16 disposed on the aluminum support 12a, and as shown in Figure 1, it is preferable that it further has an undercoat layer 14 between the aluminum support 12a and the image recording layer 16. 2 is a schematic cross-sectional view of one embodiment of an aluminum support 12a. The aluminum support 12a has a laminated structure in which an aluminum plate 18 and an aluminum anodized film 20a (hereinafter simply referred to as "anodized film 20a") are laminated in this order. The anodized film 20a in the aluminum support 12a is located on the image recording layer 16 side. In other words, the lithographic printing plate precursor 10 has the aluminum plate 18, the anodized film 20a, the undercoat layer 14, and the image recording layer 16, in this order. 2, the anodized coating 20a preferably has micropores 22a extending from its surface toward the aluminum plate 18. Note that the term "micropores" used here is a commonly used term that refers to pores in an anodized coating, and does not specify the size of the pores. As will be described in detail later, the undercoat layer 14 is not an essential component, but is a layer that is disposed as needed. Each component of the lithographic printing plate precursor 10 will be described in detail below.

[0030] [Aluminum plate] The aluminum plate 18 (aluminum support) is a dimensionally stable metal whose main component is aluminum, and is made of aluminum or an aluminum alloy. Examples of the aluminum plate 18 include a pure aluminum plate, an alloy plate whose main component is aluminum and contains trace amounts of other elements, and a plastic film or paper laminated or vapor-deposited with aluminum (alloy).

[0031] The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium, and the content of foreign elements in the alloy is 10 mass% or less. A pure aluminum plate is suitable as the aluminum plate 18, but since it is difficult to produce completely pure aluminum due to smelting technology, it is acceptable for the aluminum plate to contain traces of foreign elements. The aluminum plate 18 is not limited in composition, and any known and commonly used material (for example, JIS A 1050, JIS A 1100, JIS A 3103, and JIS A 3005) can be used as appropriate.

[0032] The width of the aluminum plate 18 is preferably about 400 to 2000 mm, and the thickness is preferably about 0.1 to 0.6 mm. These width and thickness can be changed as appropriate depending on the size of the printing press, the size of the printing plate, and the user's wishes.

[0033] [Anodic oxide film] The anodized film 20a is a film typically produced on the surface of the aluminum plate 18 by anodizing, and preferably has extremely fine micropores 22a that are substantially perpendicular to the film surface and uniformly distributed. The micropores 22a extend from the surface of the anodized film 20a on the image recording layer 16 side (the surface of the anodized film 20a on the side opposite the aluminum plate 18 side) along the thickness direction (toward the aluminum plate 18 side).

[0034] The average diameter (average opening diameter) of the micropores 22a in the anodized coating 20a at the surface of the anodized coating is preferably 10 to 150 nm, and more preferably 10 to 100 nm. From the viewpoint of a balance between stain resistance and image visibility, the average opening diameter is more preferably 15 to 100 nm, particularly preferably 15 to 60 nm, even more particularly preferably 20 to 50 nm, and most preferably 25 to 40 nm. The same effect can be obtained whether the internal diameter of the pores is wider or narrower than the surface layer. The average diameter of the micropores 22a was determined by observing the surface of the anodized film 20a with a field emission scanning electron microscope (FE-SEM) at a magnification of 150,000 times (N=4 images), and measuring 400 × 600 nm in the four images obtained. 2 The diameter of micropores present in the range is measured and averaged. When the shape of the micropores 22a is not circular, the equivalent circle diameter is used. The "equivalent circle diameter" is the diameter of a circle when the shape of the opening is assumed to be a circle having the same projected area as the projected area of ​​the opening.

[0035] The depth of the micropores 22a 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 depth is determined by taking a photograph (150,000 times) of the cross section of the anodic oxide coating 20a, measuring the depth of 25 or more micropores 22a, and averaging the measured value.

[0036] The shape of the micropores 22a is not particularly limited, and although they are generally straight (cylindrical) in Fig. 2, they may also be conical with a diameter that decreases in the depth direction (thickness direction). The shape of the bottom of the micropores 22a is also not particularly limited, and may be curved (convex) or flat.

[0037] [Undercoat layer] The undercoat layer 14 is a layer disposed between the aluminum support 12a and the image recording layer 16, and improves the adhesion between them. As described above, the undercoat layer 14 is a layer that is provided as needed, and does not necessarily have to be included in the lithographic printing plate precursor.

[0038] The constitution of the undercoat layer is not particularly limited, but it is preferable that the undercoat layer contains polyvinyl phosphonic acid in order to suppress ink adhesion in non-image areas while maintaining printing durability. Here, the polyvinylphosphonic acid that can be used includes those disclosed in US Pat. Nos. 3,276,868, 4,153,461, and 4,689,272.

[0039] The constitution of the undercoat layer is not particularly limited, but it is preferable that the undercoat layer contains a compound containing a betaine structure in order to improve stain resistance and removability after leaving it. Here, the betaine structure refers to a structure having at least one cation and at least one anion. Note that, usually, the number of cations and the number of anions are equal, and the structure is neutral as a whole, but in the present invention, when the number of cations and the number of anions are not equal, the structure also includes a necessary amount of counter ions to cancel out the charge, and is considered a betaine structure. The betaine structure is preferably any one of the structures represented by the following formula (1), formula (2), and formula (3).

[0040] [ka]

[0041] In the formula, A - represents a structure having an anion, and B + represents a structure having a cation, and L 0 represents a linking group. * represents a linking site (linking position). A - preferably represents a structure having an anion such as carboxylate, sulfonate, phosphonate, and phosphinate, and B + preferably represents a structure having a cation such as ammonium, phosphonium, iodonium, and sulfonium.

[0042] L 0 represents a linking group. In formula (1) and formula (3), L 0 In formula (2), L is a divalent linking group, and is preferably -CO-, -O-, -NH-, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. 0 Examples of the linking group include a trivalent linking group. The linking group is preferably a linking group having 30 or less carbon atoms, including the carbon atoms of the substituents that may be included, which will be described later. Specific examples of the linking group include alkylene groups (preferably having 1 to 20 carbon atoms, more preferably having 1 to 10 carbon atoms), and arylene groups such as phenylene and xylylene groups (preferably having 5 to 15 carbon atoms, more preferably having 6 to 10 carbon atoms).

[0043] These linking groups may further have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a cyano group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a monoalkylamino group, a dialkylamino group, a monoarylamino group, and a diarylamino group.

[0044] As the betaine structure, a structure represented by formula (i), formula (ii), or formula (iii) is preferred, and a structure represented by formula (i) is more preferred, in that at least one of printing durability, stain resistance, removability after standing, and image visibility is superior. * represents a linking site.

[0045] [ka]

[0046] In formula (i), R 1 and R 2 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group; R 1 and R 2 may be linked to each other to form a ring structure. The ring structure may have a hetero atom such as an oxygen atom, etc. The ring structure is preferably a 5- to 10-membered ring, more preferably a 5- or 6-membered ring. R 1 and R 2 The number of carbon atoms therein is preferably 1 to 30, and more preferably 1 to 20. R 1 and R 2 As the alkyl group, a hydrogen atom, a methyl group, or an ethyl group is preferred in terms of achieving better effects of the present invention.

[0047] L 1represents a divalent linking group, and is preferably -CO-, -O-, -NH-, a divalent aliphatic group (for example, an alkylene group), a divalent aromatic group (for example, a phenylene group), or a combination thereof. L 1 is preferably a linear alkylene group having 3 to 5 carbon atoms.

[0048] In formula (i), A - represents a structure having an anion, and is preferably a carboxylate, sulfonate, phosphonate, or phosphinate. Specifically, the following structures are included:

[0049] [ka]

[0050] In formula (i), L 1 is a linear alkylene group having 4 or 5 carbon atoms, and A - is a sulfonate, and L 1 is a linear alkylene group having 4 carbon atoms, and A - is a sulfonate.

[0051] In formula (ii), L 2 represents a divalent linking group, and is preferably -CO-, -O-, -NH-, a divalent aliphatic group (for example, an alkylene group), a divalent aromatic group (for example, a phenylene group), or a combination thereof. B + represents a structure having a cation, and a structure having ammonium, phosphonium, iodonium, or sulfonium is preferred. Among these, a structure having ammonium or phosphonium is preferred, and a structure having ammonium is more preferred. Examples of the structure having a cation include a trimethylammonio group, a triethylammonio group, a tributylammonio group, a benzyldimethylammonio group, a diethylhexylammonio group, a (2-hydroxyethyl)dimethylammonio group, a pyridinio group, an N-methylimidazolino group, an N-acridinio group, a trimethylphosphonio group, a triethylphosphonio group, and a triphenylphosphonio group.

[0052] In formula (iii), L 3 represents a divalent linking group, and is preferably -CO-, -O-, -NH-, a divalent aliphatic group (for example, an alkylene group), a divalent aromatic group (for example, a phenylene group), or a combination thereof. A - represents a structure having an anion, and is preferably a carboxylate, a sulfonate, a phosphonate, or a phosphinate. The details and preferred examples thereof are as follows: A - is the same as: R 3 ~R 7 each independently represents a hydrogen atom or a substituent (preferably having 1 to 30 carbon atoms), and R 3 ~R 7 At least one of the represents a linkage site. R, the linking site 3 ~R 7 At least one of the 3 ~R 7 It may be linked to another site in the compound via a substituent as at least one of the groups or may be directly linked to another site in the compound via a single bond.

[0053] R 3 ~R 7Examples of the substituent represented by the formula (I) 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 alkoxycarbonyloxy group, an aryloxycarbon ... Examples of such groups include a carboxylamino 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 imido group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, and a silyl group.

[0054] The compound is preferably a polymer containing a repeating unit having a betaine structure (hereinafter, also simply referred to as a "specific polymer"), in that the effects of the present invention are more excellent. The repeating unit having a betaine structure is preferably a repeating unit represented by formula (A1).

[0055] [ka]

[0056] 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. The divalent linking group may be -CO-, -O-, -NH-, a divalent aliphatic group, a divalent aromatic group, or a combination thereof.

[0057] Specific examples of L having the above combinations are listed below. In the examples below, the left side is bonded to the main chain, and the right side is bonded 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-

[0058] Divalent aliphatic groups include alkylene groups, alkenylene groups, and alkynylene groups. The divalent aromatic group includes an aryl group, and is preferably a phenylene group or a naphthylene group.

[0059] X represents a betaine structure. X is preferably a structure represented by the above formula (i), formula (ii), or formula (iii). In particular, in formula (A1), L is L1 or L3, X is a structure represented by formula (i), and A in formula (i) - is a sulfonate group.

[0060] The content of repeating units having a betaine structure in the specific polymer is not particularly limited and is often 20 to 95% by mass. In terms of better effects of the present invention, the content is preferably 50 to 95% by mass, and more preferably 60 to 90% by mass, based on the total repeating units constituting the specific polymer.

[0061] The specific polymer may contain repeating units other than the repeating unit having the betaine structure. The specific polymer may contain a repeating unit having a structure that interacts with the surface of the aluminum support 12a (hereinafter, also simply referred to as "interactive structure"). Examples of the interacting structure include a carboxylic acid structure, a carboxylate structure, a sulfonic acid structure, a sulfonate structure, a phosphonic acid structure, a phosphonate structure, a phosphoric acid ester structure, a phosphoric acid ester salt structure, a β-diketone structure, and a phenolic hydroxyl group, and examples thereof include structures represented by the following formulas: Among these, a carboxylic acid structure, a carboxylate structure, a sulfonic acid structure, a sulfonate structure, a phosphonic acid structure, a phosphonate structure, a phosphoric acid ester structure, or a phosphoric acid ester salt structure is preferred.

[0062] [ka]

[0063] In the above formula, R 11 ~R 13 each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkynyl group, or an alkenyl group, and 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.

[0064] The repeating unit having an interacting structure is preferably a repeating unit represented by formula (A2).

[0065] [ka]

[0066] In the formula, R 201 ~R 203 each 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 the divalent linking group include -CO-, -O-, -NH-, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. Specific examples of L that are combinations include those in the above formula (A1) and the following L17 and L18. L17:-CO-NH- L18:-CO-O- Among L1 to L18, L1 to L4, L17, or L18 is preferred. Q represents an interacting structure, and the preferred embodiments are the same as those described above.

[0067] The content of the repeating unit having an interacting structure in the specific polymer is not particularly limited, but in terms of achieving better effects of the present invention, it is preferably 1 to 40 mass % and more preferably 3 to 30 mass % of the total repeating units constituting the specific polymer.

[0068] The specific polymer may contain a repeating unit having a radically polymerizable reactive group. Examples of the radically polymerizable reactive group include an addition-polymerizable unsaturated bond group (e.g., a (meth)acryloyl group, a (meth)acrylamide group, a (meth)acrylonitrile group, an allyl group, a vinyl group, a vinyloxy group, and an alkynyl group), and a functional group capable of chain transfer (e.g., a mercapto group). The specific polymer containing a repeating unit having a radically polymerizable reactive group can be obtained by introducing the radically polymerizable reactive group by the method described in JP 2001-312068 A. By using the specific polymer containing a repeating unit having a radically polymerizable reactive group, excellent developability is exhibited in the unexposed areas, and the permeability of the developer is suppressed by polymerization in the exposed areas, further improving the adhesion and cohesion between the aluminum support 12a and the image recording layer 16.

[0069] The content of the repeating unit having a radically polymerizable reactive group in the specific polymer is not particularly limited, but in terms of achieving better effects of the present invention, it is preferably 1 to 30 mass % and more preferably 3 to 20 mass % relative to all repeating units constituting the specific polymer.

[0070] The content of the compound having a betaine structure in the undercoat layer 14 is not particularly limited, but 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 can be 100% by mass.

[0071] Although the undercoat layer 14 containing a compound having a betaine structure has been described above, the undercoat layer may also contain other compounds. For example, the undercoat layer may contain a compound having a hydrophilic group, such as a carboxylic acid group or a sulfonic acid group. The compound having a hydrophilic group may further have a radically polymerizable reactive group.

[0072] [Image recording layer] The image recording layer 16 is preferably an image recording layer that is removable with printing ink and / or dampening water. Each component of the image recording layer 16 will now be described.

[0073] <Infrared absorber> The image recording layer 16 preferably contains an infrared absorbing agent. The infrared absorber preferably has an absorption maximum in the wavelength range of 750 to 1400 nm. In particular, in the case of an on-press development type lithographic printing plate precursor, since the on-press development may be performed in a printing press under white light, by using an infrared absorber having an absorption maximum in the wavelength range of 750 to 1400 nm, which is less susceptible to the influence of white light, a lithographic printing plate precursor with excellent developability can be obtained. The infrared absorbing agent is preferably a dye or a pigment.

[0074] Examples of dyes include commercially available dyes and known dyes described in literature such as "Dye Handbook" (edited by the Society of Organic Synthetic Chemistry, published in 1970). Specific examples of the dye include cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Among these, 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.

[0075] Formula (a) [ka]

[0076] In formula (a), X 1 represents a hydrogen atom, a halogen atom, -N(R 9 )(R 10 ), -X 2 -L 1 or represents the group shown below.

[0077] [ka]

[0078] R 9 and R 10 each independently represents an aromatic hydrocarbon group, an alkyl group, or a hydrogen atom; R 9 and R 10 and may be bonded to each other to form a ring. Among these, a phenyl group is preferred. X2 represents an oxygen atom or a sulfur atom, and L 1 represents a hydrocarbon group having 1 to 12 carbon atoms which may contain a heteroatom (N, S, O, a halogen atom, Se). X a - is Z, which will be described later. a - is defined similarly to R a represents a hydrogen atom, an alkyl group, an aryl group, an amino group, or a halogen atom.

[0079] R 1 and R 2 each independently represents a hydrocarbon group having 1 to 12 carbon atoms. 1 and R 2 may be bonded 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 independently represents an aromatic hydrocarbon group which may have a substituent (for example, an alkyl group). The aromatic hydrocarbon group is preferably a benzene ring group or a naphthalene ring group. Y 1 and Y 2 each independently represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R 3 and R 4 each independently represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent (for example, an alkoxy group). R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. Also, Za - represents a counter anion. However, when the cyanine dye represented by formula (a) has an anionic substituent in its structure and charge neutralization is not required, Za - is not necessary. -Examples of the cation include halide ions, perchlorate ions, tetrafluoroborate ions, hexafluorophosphate ions, and sulfonate ions, with perchlorate ions, hexafluorophosphate ions, and arylsulfonate ions being preferred.

[0080] The infrared absorbing dyes may be used alone or in combination of two or more, and may be used in combination with an infrared absorbing agent other than the infrared absorbing dye, such as a pigment. As the pigment, the compounds described in paragraphs

[0072] to

[0076] of JP-A No. 2008-195018 are preferred.

[0081] The content of the infrared absorbing agent is preferably from 0.05 to 30% by mass, more preferably from 0.1 to 20% by mass, based on the total mass of the image recording layer 16.

[0082] <Polymerization initiator> The image recording layer 16 preferably contains a polymerization initiator. The polymerization initiator is preferably a compound that generates radicals by the energy of light, heat, or both, and initiates polymerization of a compound having a polymerizable unsaturated group (so-called radical polymerization initiator). Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator. Specifically, the polymerization initiator may be any of those described in paragraphs

[0115] to

[0141] of JP-A-2009-255434. From the viewpoint of reactivity and stability, the polymerization initiator is preferably an oxime ester compound or an onium salt such as a diazonium salt, an iodonium salt, or a sulfonium salt.

[0083] The content of the polymerization initiator is preferably from 0.1 to 50% by mass, more preferably from 0.5 to 30% by mass, based on the total mass of the image recording layer 16.

[0084] <Polymerizable compound> The image recording layer 16 preferably contains a polymerizable compound. The polymerizable compound is preferably an addition-polymerizable compound having at least one ethylenically unsaturated bond. Among them, a compound having at least one (preferably two) terminal ethylenically unsaturated bond is more preferred. A so-called radical-polymerizable compound is more preferred. As the polymerizable compound, for example, the polymerizable compounds exemplified in paragraphs

[0142] to

[0163] of JP-A No. 2009-255434 can be used.

[0085] Also suitable are urethane-based addition-polymerizable compounds produced by the addition reaction of isocyanate with hydroxyl groups. Specific examples include vinyl urethane compounds containing two or more polymerizable vinyl groups per molecule, which are obtained by adding a vinyl monomer containing a hydroxyl group, as shown in the following formula (A), to a polyisocyanate compound having two or more isocyanate groups per molecule, as described in JP-B-48-041708: CH2=C(R 4 )COOCH2CH(R 5 )OH (A) (However, R 4 and R 5 indicates H or CH3.)

[0086] The content of the polymerizable compound is preferably from 3 to 80% by mass, more preferably from 10 to 75% by mass, based on the total mass of the image recording layer 16.

[0087] <Binder polymer> The image recording layer 16 preferably contains a binder polymer. Examples of the binder polymer include known binder polymers, specifically acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, methacrylic resins, polystyrene-based resins, novolac-type phenolic resins, polyester resins, synthetic rubbers, and natural rubbers. The binder polymer may have crosslinking properties to improve the film strength of the image area. To impart crosslinking properties to the binder polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may also be introduced by copolymerization. As the binder polymer, for example, the binder polymers disclosed in paragraphs

[0165] to

[0172] of JP-A-2009-255434 can be used.

[0088] The content of the binder polymer is preferably from 5 to 90% by mass, more preferably from 5 to 70% by mass, based on the total mass of the image recording layer 16.

[0089] <Surfactant> The image recording layer 16 may contain a surfactant to promote on-press developability at the start of printing and to improve the coated surface condition. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorine-based surfactants. As the surfactant, for example, the surfactants disclosed in paragraphs

[0175] to

[0179] of JP-A-2009-255434 can be used.

[0090] The content of the surfactant is preferably from 0.001 to 10% by mass, more preferably from 0.01 to 5% by mass, based on the total mass of the image recording layer 16.

[0091] <Color former> The image recording layer 16 preferably contains a color former, more preferably an acid color former. As used herein, the term "color former" refers to a compound that develops or loses color in response to stimulation by light, acid, or the like, thereby changing the color of the image recording layer, and the term "acid color former" refers to a compound that develops or loses color in response to heating while accepting an electron-accepting compound (e.g., a proton from an acid, etc.). Preferred acid color formers are colorless compounds that have a partial skeleton, such as a lactone, lactam, sultone, spiropyran, ester, or amide, and that rapidly open or cleave this partial skeleton when contacted with an electron-accepting compound.

[0092] Examples of such acid color formers include 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide (also known 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-dimethylindol-3-yl)phthalide, 3-(4-dimethylaminophenyl)-3-(2-methylphenyl) ...1,2-dimethylindol-3-yl)phthalide, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)phthalide, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)phthalide, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)phthalide, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylin 3-(4-dimethylaminophenyl)-3-(1-methylpyrrol-3-yl)-6-dimethylaminophthalide, 3,3-bis(1,2-dimethylindol-3-yl)-5-dimethylaminophthalide, 3,3-bis(1,2-dimethylindol-3-yl)-6-dimethylaminophthalide, 3,3-bis(9-ethylcarbazol-3-yl)-6-dimethylaminophthalide, 3,3-bis(2-phenylindol-3-yl)-6-dimethylaminophthalide, 3-(4-dimethylaminophenyl)-3-(1-methylpyrrol-3-yl)-6-dimethylaminophthalide,

[0093] 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 3-[1,1-di(1-ethyl-2-methylindol-3-yl)ethylene-2-yl]-3-(4-diethylaminophenyl)phthalide, 3-[1,1-di(1-ethyl-2-methylindol-3-yl)ethylene-2-yl]-3-(4-N-ethyl-N-phenylaminophenyl)phthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindol-3-yl)phthalide, 3,3-bis(1-n-octyl-2-methylindol-3-yl)phthalide, and 3-(2-methyl-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindol-3-yl)phthalide;

[0094] 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, benzoylleuco methylene blue, 4-nitrobenzoyl methylene blue,

[0095] 3,6-Dimethoxyfluoran, 3-dimethylamino-7-methoxyfluoran, 3-diethylamino-6-methoxyfluoran, 3-diethylamino-7-methoxyfluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-6,7-dimethylfluoran, 3-N-cyclohexyl-Nn-butylamino-7-methylfluoran, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-octylaminofluoran, 3-diethylamino-7-di-n-hexylaminofluoran, 3-diethylamino-7-anilinofluoran, 3- Diethylamino-7-(2'-fluorophenylamino)fluoran, 3-diethylamino-7-(2'-chlorophenylamino)fluoran, 3-diethylamino-7-(3'-chlorophenylamino)fluoran, 3-diethylamino-7-(2',3'-dichlorophenylamino)fluoran, 3-diethylamino-7-(3'-trifluoromethylphenylamino)fluoran, 3-di-n-butylamino-7-(2'-fluorophenylamino)fluoran, 3-di-n-butylamino-7-(2'-chlorophenylamino)fluoran, 3-N-isopentyl-N-ethylamino-7-(2'-chlorophenylamino)fluoran,

[0096] 3-Nn-hexyl-N-ethylamino-7-(2'-chlorophenylamino)fluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-di-n-butylamino-6-chloro-7-anilinofluoran, 3-diethylamino-6-methoxy-7-anilinofluoran, 3-di-n-butylamino-6-ethoxy-7-anilinofluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3-morpholino- 6-Methyl-7-anilinofluoran, 3-dimethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-di-n-butylamino-6-methyl-7-anilinofluoran, 3-di-n-pentylamino-6-methyl-7-anilinofluoran, 3-N-ethyl-N-methylamino-6-methyl-7-anilinofluoran, 3-Nn-propyl-N-methylamino-6-methyl-7-anilinofluoran, 3-Nn-propyl-N-ethyl N-butyl-N-ethylamino-6-methyl-7-anilinofluoran, 3-Nn-butyl-N-ethylamino-6-methyl-7-anilinofluoran, 3-N-isobutyl-N-methylamino-6-methyl-7-anilinofluoran, 3-N-isobutyl-N-ethylamino-6-methyl-7-anilinofluoran, 3-N-isopentyl-N-ethylamino-6-methyl-7-anilinofluoran, 3-Nn-hexyl-N-methylamino amino-6-methyl-7-anilinofluoran, 3-N-cyclohexyl-N-ethylamino-6-methyl-7-anilinofluoran, 3-N-cyclohexyl-Nn-propylamino-6-methyl-7-anilinofluoran, 3-N-cyclohexyl-Nn-butylamino-6-methyl-7-anilinofluoran, 3-N-cyclohexyl-Nn-hexylamino-6-methyl-7-anilinofluoran, 3-N-cyclohexyl-Nn-octylamino-6-methyl-7-anilinofluoran,

[0097] 3-N-(2'-Methoxyethyl)-N-methylamino-6-methyl-7-anilinofluoran, 3-N-(2'-Methoxyethyl)-N-ethylamino-6-methyl-7-anilinofluoran, 3-N-(2'-Methoxyethyl)-N-isobutylamino-6-methyl-7-anilinofluoran, 3-N-(2'-Ethoxyethyl)-N-methylamino-6-methyl-7-anilinofluoran, 3-N-(2'-Ethoxyethyl)-N-ethylamino-6-methyl-7 -Anilinofluoran, 3-N-(3'-methoxypropyl)-N-methylamino-6-methyl-7-anilinofluoran, 3-N-(3'-methoxypropyl)-N-ethylamino-6-methyl-7-anilinofluoran, 3-N-(3'-ethoxypropyl)-N-methylamino-6-methyl-7-anilinofluoran, 3-N-(3'-ethoxypropyl)-N-ethylamino-6-methyl-7-anilinofluoran, 3-N-(2'-tetrahydrofurfuryl)- N-ethylamino-6-methyl-7-anilinofluoran, 3-N-(4'-methylphenyl)-N-ethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-ethyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-(3'-methylphenylamino)fluoran, 3-diethylamino-6-methyl-7-(2',6'-dimethylphenylamino)fluoran, 3-di-n-butylamino-6-methyl-7-(2',6'-dimethylphenylamino)fluoran fluorans such as 3-[4'-(4-phenylaminophenyl)aminophenyl]amino-6-methyl-7-chlorofluoran, 3-di-n-butylamino-7-(2',6'-dimethylphenylamino)fluoran, 2,2-bis[4'-(3-N-cyclohexyl-N-methylamino-6-methylfluoran)-7-ylaminophenyl]propane, 3-[4'-(4-phenylaminophenyl)aminophenyl]amino-6-methyl-7-chlorofluoran, and 3-[4'-(dimethylaminophenyl)]amino-5,7-dimethylfluoran;

[0098] 3-(2-methyl-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-n-propoxycarbonylamino-4-di-n-propylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-methylamino-4-di-n-propylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-methyl-4-di-n-hexylaminophenyl)-3-(1-n-octyl -2-methylindol-3-yl)-4,7-diazaphthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3,3-bis(1-n-octyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-octyl-2-methylindol-3-yl)-4 or 7-azaphthalide, 3-(2 -ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4 or 7-azaphthalide, 3-(2-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4 or 7-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-phenylindol-3-yl)-4 or 7-azaphthalide, 3-(2-butoxy-4-diethylaminophenyl)-3-(1-ethyl-2-phenylindol-3 -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)fluorene-9-spiro-3'-(6'-dimethylamino)phthalide, and other phthalides;

[0099] 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-dibenzylamino-6'-N,N-diethylaminospiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one, 2'-(N-methyl-N-phenyl)amino-6'-(N-ethyl-N-(4-methylphenyl))aminospiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one, and the like.

[0100] In particular, from the viewpoint of color development, the color former used in the present disclosure is preferably at least one compound selected from the group consisting of spiropyran compounds, spirooxazine compounds, spirolactone compounds, and spirolactam compounds. The hue of the dye after color development is preferably green, blue or black from the viewpoint of visibility.

[0101] The acid color former is preferably a leuco dye from the viewpoints of color development and visibility of exposed areas. The leuco dye is not particularly limited as long as it has a leuco structure, but preferably has a spiro structure, and more preferably has a spirolactone ring structure. In addition, the leuco dye is preferably a leuco dye having a phthalide structure or a fluoran structure in terms of color development and visibility of the exposed area. Furthermore, from the viewpoints of color development and visibility of exposed areas, the leuco dye having the phthalide structure or the fluoran structure is preferably a compound represented by any one of the following formulas (Le-1) to (Le-3), and more preferably a compound represented by the following formula (Le-2).

[0102] [ka]

[0103] In formulae (Le-1) to (Le-3), ERG each independently represents an electron-donating group, X1 to X4 each independently represent a hydrogen atom, a halogen atom or a dialkylanilino group, and X5 to X 10 each independently represent a hydrogen atom, a halogen atom, or a monovalent organic group; Y1 and Y2 each independently represent C or N; when Y1 is N, X1 is not present; when Y2 is N, X4 is not present; 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.

[0104] In terms of color development and visibility of exposed areas, the electron-donating group in ERG of Formulae (Le-1) to (Le-3) is preferably an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group; more preferably an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, or an aryloxy group; still more preferably a monoalkylmonoarylamino group, a diarylamino group, a diheteroarylamino group, or a monoarylmonoheteroarylamino group; and particularly preferably a monoalkylmonoarylamino group. Furthermore, in terms of color development and visibility of exposed areas, the electron-donating group in the above-mentioned ERG is preferably a di-substituted amino group having 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 a di-substituted amino group having a phenyl group having a substituent at at least one ortho-position and an electron-donating group at the para-position, still more preferably an amino group having a phenyl group having a substituent at at least one ortho-position and an electron-donating group at the para-position and an aryl group or a heteroaryl group, and particularly preferably an amino group having a phenyl group having a substituent at at least one ortho-position and an electron-donating group at the para-position and an aryl group having an electron-donating group or a heteroaryl group having an electron-donating group. In the present disclosure, the ortho position in an aryl group or heteroaryl group other than a phenyl group refers to the bonding position adjacent to the bonding position 1 (e.g., the 2nd position) of the aryl group or heteroaryl group to another structure, where the bonding position is the 1st position. Furthermore, from the viewpoints of color development and visibility of exposed areas, the electron-donating group contained in the aryl group or heteroaryl group is preferably an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group, more preferably an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group, and even more preferably an alkoxy group.

[0105] In the formulae (Le-1) to (Le-3), X1 to X4 are each independently preferably a hydrogen atom or a chlorine atom, more preferably a hydrogen atom, from the viewpoint of color development and visibility of exposed areas. X5 to X in formula (Le-2) or formula (Le-3) 10are each independently, from the viewpoints of color development and visibility of exposed areas, preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, a hydroxy group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a heteroaryloxycarbonyl group, or a cyano group; more preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, or an aryloxy group; still more preferably a hydrogen atom, a halogen atom, an alkyl group, or an aryl group; and particularly preferably a hydrogen atom. In terms of color development and visibility of exposed areas, at least one of Y1 and Y2 in formulae (Le-1) to (Le-3) is preferably C, and both Y1 and Y2 are preferably C. In terms of color development and visibility of exposed areas, Ra1 in formulae (Le-1) to (Le-3) is preferably an alkyl group or an alkoxy group, more preferably an alkoxy group, and even more preferably a methoxy group. In formulae (Le-1) to (Le-3), Rb1 to Rb4 are each independently preferably a hydrogen atom or an alkyl group, more preferably an alkyl group, and further preferably a methyl group, from the viewpoints of color development and visibility of exposed areas.

[0106] Furthermore, in terms of color development and visibility of exposed areas, the leuco dye having the phthalide structure or the fluoran structure is more preferably a compound represented by any one of the following formulas (Le-4) to (Le-6), and even more preferably a compound represented by the following formula (Le-5).

[0107] [ka]

[0108] In formulas (Le-4) to (Le-6), ERG each independently represents an electron-donating group, 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, provided that when Y1 is N, X1 is not present, and when Y2 is N, X4 is not present, 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.

[0109] ERG, X1 to X4, Y1, Y2, Ra1, and Rb1 to Rb4 in formulae (Le-4) to (Le-6) have the same meanings as ERG, X1 to X4, Y1, Y2, Ra1, and Rb1 to Rb4 in formulae (Le-1) to (Le-3), respectively, and the preferred embodiments are also the same.

[0110] Furthermore, from the viewpoints of color development and visibility of exposed areas, the leuco dye having the phthalide structure or the fluoran structure is more preferably a compound represented by any one of the following formulas (Le-7) to (Le-9), and particularly preferably a compound represented by the following formula (Le-8).

[0111] [ka]

[0112] 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; when Y1 is N, X1 is not present; and when Y2 is N, X4 is not present; 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.

[0113] X1 to X4, Y1 and Y2 in formulae (Le-7) to (Le-9) have the same meanings as X1 to X4, Y1 and Y2 in formulae (Le-1) to (Le-3), and preferred embodiments are also the same. In terms of color development and visibility of exposed areas, 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 standpoints of color development and visibility of exposed areas. In formulae (Le-7) to (Le-9), Rb1 to Rb4 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 further preferably a methyl group, from the viewpoints of color development and visibility of exposed areas. In formula (Le-8), Rc1 and Rc2 are each independently preferably a phenyl group or an alkylphenyl group, more preferably a phenyl group, from the standpoint of color development and visibility of exposed areas. In addition, in terms of color development and visibility of exposed areas, 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 substituents in Rc1 and Rc2 include the substituents described below. In addition, in formula (Le-8), it is preferable that X1 to X4 are hydrogen atoms and Y1 and Y2 are carbon atoms, from the viewpoint of color development and visibility of exposed areas. Furthermore, in formula (Le-8), from the viewpoint of color development and visibility of exposed areas, it is preferred that Rb1 and Rb2 each independently represent an aryl group substituted with an alkyl group or an alkoxy group. Furthermore, in formula (Le-8), from the viewpoints of color development and visibility of exposed areas, Rb1 and Rb2 are each preferably independently an aryl group or a heteroaryl group, more preferably an aryl group, still 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, from the viewpoints of color development and visibility of exposed areas, the electron-donating group in Rb1, Rb2, Rc1, and Rc2 is preferably an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group, more preferably an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group, and even more preferably an alkoxy group.

[0114] Furthermore, the acid color former preferably contains a compound represented by the following formula (Le-10) from the viewpoints of color development and visibility of exposed areas.

[0115] [ka]

[0116] In formula (Le-10), each Ar1 independently represents an aryl group or a heteroaryl group, and each Ar2 independently represents 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.

[0117] Ar1 in formula (Le-10) has the same meaning as Rb1 and Rb2 in formulae (Le-7) to (Le-9), and preferred embodiments are also the same. Ar2 in formula (Le-10) has the same meaning as Rc1 and Rc2 in formulae (Le-7) to (Le-9), and preferred embodiments are also the same.

[0118] The alkyl group in formulae (Le-1) to (Le-9) may be linear, branched, or have a ring structure. Furthermore, the alkyl group in formulae (Le-1) to (Le-9) preferably has 1 to 20 carbon atoms, more preferably 1 to 8 carbon atoms, even more preferably 1 to 4 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The aryl group in formulae (Le-1) to (Le-10) preferably has 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms, and even more preferably 6 to 8 carbon atoms. Specific examples of the aryl group in formulae (Le-1) to (Le-10) include a phenyl group, a naphthyl group, an anthracenyl group, and a phenanthrenyl group, each of which may have a substituent. Specific examples of the heteroaryl group in formulae (Le-1) to (Le-10) include a furyl group, a pyridyl group, a pyrimidyl group, a pyrazoyl group, and a thiophenyl group, each of which may have a substituent.

[0119] Furthermore, each of the monovalent organic groups, alkyl groups, aryl groups, heteroaryl groups, dialkylanilino groups, alkylamino groups, and alkoxy groups in Formulae (Le-1) to (Le-10) may have a substituent. Examples of the substituent 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, hydroxy groups, alkoxy groups, aryloxy groups, heteroaryloxy groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, heteroaryloxycarbonyl groups, and cyano groups. Furthermore, these substituents may be further substituted with other substituents.

[0120] Suitable leuco dyes having a phthalide structure or a fluoran structure include the following compounds: where Me represents a methyl group.

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] [ka]

[0128] As the color former, commercially available products can be used, such as ETAC, RED500, RED520, CVL, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, BLUE220, H-3035, BLUE203, ATP, H-1046, and H-2114 (all manufactured by Fukui Yamada Chemical Co., Ltd.), ORANGE-DCF, and Vermilio. Examples of such dyes include n-DCF, PINK-DCF, RED-DCF, BLMB, CVL, GREEN-DCF, and 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, and Red-8 (all manufactured by Yamamoto Chemical Industries, 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 films formed have good visible light absorptivity.

[0129] These color formers may be used alone or in combination of two or more components. The content of the color former is preferably 0.5 to 10% by mass, and more preferably 1 to 5% by mass, based on the total mass of the image recording layer.

[0130] The image recording layer 16 may further contain compounds other than those mentioned above, if necessary. Examples of other compounds include colorants, print-out 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 JP-A-2009-255434. Other compounds include hydrophobic precursors (fine particles that can convert the image recording layer to a hydrophobic state when heat is applied), low-molecular-weight hydrophilic compounds, oil-sensitizing agents (for example, phosphonium compounds, nitrogen-containing low-molecular-weight compounds, and ammonium group-containing polymers), and chain transfer agents, all of which are disclosed in paragraphs

[0191] to

[0217] of JP2012-187907A.

[0131] [Other layers] The lithographic printing plate precursor of the present invention may include layers other than the aluminum support 12 a, the undercoat layer 14 and the image recording layer 16 described above. For example, a protective layer may be included on the image recording layer 16 as needed to prevent scratches on the image recording layer 16, block oxygen, and prevent ablation during exposure to high-intensity laser light. Examples of materials that can be used for the protective layer include those described in paragraphs

[0213] to

[0227] of JP-A No. 2009-255434 (water-soluble polymer compounds, inorganic layered compounds, etc.).

[0132] [Method of manufacturing aluminum support] The method for producing the aluminum support used in the lithographic printing plate precursor of the present invention is not particularly limited, but from the viewpoint of efficiently producing a desired aluminum support, it is preferable to use a method in which the aluminum plate is treated in a hydrochloric acid treatment solution which may contain sulfuric acid, the temperature of the hydrochloric acid treatment solution is 30°C or less, and the total amount of electricity involved in the anodic reaction of the aluminum plate is 400 C / dm 2 Below this, the peak current value of the AC current waveform is 80A / dm 2 It is preferable to have a hydrochloric acid electrolysis step below in which AC electrolysis is performed to produce a surface-roughened aluminum plate. When the hydrochloric acid treatment solution contains sulfuric acid, the ratio of the content of sulfuric acid to the content of hydrochloric acid is preferably 0.1 or less. Furthermore, the method for producing an aluminum support of the present invention preferably includes, after the hydrochloric acid electrolytic treatment step, an anodizing treatment step in which the surface-roughened aluminum plate is anodized to form an anodized aluminum film on the aluminum plate. Furthermore, the method for producing an aluminum support of the present invention preferably includes, after the anodizing treatment step, a pore widening treatment step in which the aluminum plate on which the anodized film has been formed is subjected to an etching treatment to enlarge the diameter of micropores in the anodized film. Each of the above steps and optional treatments will now be described in detail.

[0133] <Mechanical roughening treatment> In the method for producing an aluminum support of the present invention, a mechanical surface roughening treatment may be carried out before the hydrochloric acid electrolytic treatment step. Examples of mechanical roughening treatment methods that can be used include the wire brush graining method, in which the aluminum surface is scratched with a metal wire; the ball graining method, in which the aluminum surface is grained using abrasive balls and an abrasive; and the brush graining method, in which the surface is grained using a nylon brush and an abrasive, as described in Japanese Patent Laid-Open Publication No. 6-135175 and Japanese Patent Publication No. 50-040047.

[0134] <Hydrochloric acid electrolysis process> The hydrochloric acid electrolysis step in the method for producing an aluminum support of the present invention involves treating an aluminum plate in a hydrochloric acid treatment solution which may contain sulfuric acid, the temperature of the hydrochloric acid treatment solution being 30°C or less, and the total amount of electricity involved in the anodic reaction of the aluminum plate being 400 C / dm 2 Below this, the peak current value of the AC current waveform is 80A / dm 2 The following is preferably a hydrochloric acid electrolysis step in which AC electrolysis is performed to produce a surface-roughened aluminum plate. In the present invention, the above-mentioned lithographic printing plate precursor (first and second embodiments of the lithographic printing plate precursor) can be efficiently produced by carrying out such hydrochloric acid electrolysis and then carrying out the anodizing treatment described below.

[0135] The hydrochloric acid treatment solution contains hydrochloric acid, and the concentration of hydrochloric acid is preferably 5 to 30 g / L, and more preferably 10 to 20 g / L. The hydrochloric acid treatment solution may contain sulfuric acid. When 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, more preferably 1.0 g / L or less, and even more preferably 0.5 g / L. When the hydrochloric acid treatment solution contains sulfuric acid, the lower limit of the sulfuric acid concentration in the hydrochloric acid treatment solution is not particularly limited, and may be more than 0 g / L. The hydrochloric acid treatment solution may contain aluminum ions. When the hydrochloric acid treatment solution contains aluminum ions, the concentration of the aluminum ions is preferably 1.0 to 30.0 g / L, and more preferably 5.0 to 20.0 g / L. When the hydrochloric acid treatment solution contains sulfuric acid, the ratio of the content of sulfuric acid to the content of hydrochloric acid is preferably 0.1 or less. The temperature of the hydrochloric acid treatment solution is 30° C. or lower, preferably 26° C. or lower, and more preferably 23° C. or lower. There is no particular lower limit, but the temperature is preferably 10° C. or higher, and more preferably 15° C. or higher.

[0136] In the present invention, the total amount of electricity (the total amount of electricity involved in the anodic reaction of the aluminum plate at the time when the hydrochloric acid electrolysis treatment is completed) is 400 C / dm 2 Less than 350C / dm is preferable. 2 The lower limit of the total amount of electricity is not particularly limited, but it is more preferably 50 C / dm 2 More than 100C / dm is preferable. 2 The above is more preferable. The peak current value of the AC current waveform is 80A / dm 2 Less than 70A / dm is preferable. 2 The peak current value is preferably 10 A / dm or less.2 More than 20A / dm is preferable. 2 The above is more preferable.

[0137] The alternating current waveform for the hydrochloric acid electrolysis treatment can be a sine wave, a square wave, a trapezoidal wave, a triangular wave, etc. The frequency is preferably 0.1 to 250 Hz. FIG. 3 is a graph showing an example of an alternating current waveform used in hydrochloric acid electrolysis. In FIG. 3, ta is the anode reaction time, tc is the cathode reaction time, tp is the time it takes for the current to reach its peak from 0, Ia is the current at the peak on the anode cycle side, and Ic is the current at the peak on the cathode cycle side. In the trapezoidal wave, the time it takes for the current to reach its peak from 0, tp, is preferably 1 to 10 msec. The conditions for one cycle of AC used in hydrochloric acid electrolysis are preferably such that the ratio tc / ta of the anode reaction time ta of the aluminum plate to the cathode reaction time tc is 1 to 20, the ratio Qc / Qa of the quantity of electricity when the aluminum plate is the anode to the quantity of electricity Qa when the aluminum plate is the anode is 0.3 to 20, and the anode reaction time ta is 5 to 1000 msec. The current density is the peak value of the trapezoidal wave, and both the anode cycle side Ia and the cathode cycle side Ic of the current are within the above-mentioned range (80 A / dm 2 (see below) is preferred.

[0138] The apparatus shown in FIG. 4 can be used for hydrochloric acid electrolysis using alternating current. FIG. 4 is a side view showing an example of a radial cell for hydrochloric acid electrolysis using alternating current. In Figure 4, 50 is a main electrolytic cell, 51 is an AC power supply, 52 is a radial drum roller, 53a and 53b are main electrodes, 54 is an electrolyte supply port, 55 is an electrolyte, 56 is a slit, 57 is an electrolyte passage, 58 is an auxiliary anode, 60 is an auxiliary anode cell, and W is an aluminum plate. When two or more electrolytic cells are used, the electrolysis conditions may be the same or different. The aluminum sheet W is wound around a radial drum roller 52 immersed in a main electrolytic cell 50, and is electrolyzed by main electrodes 53a and 53b connected to an AC power source 51 during transportation. An electrolyte 55 is supplied from an electrolyte supply port 54 through a slit 56 to an electrolyte passage 57 between the radial drum roller 52 and the main electrodes 53a and 53b. The aluminum sheet W treated in the main electrolytic cell 50 is then electrolyzed in an auxiliary anode cell 60. In this auxiliary anode cell 60, an auxiliary anode 58 is disposed opposite the aluminum sheet W, and the electrolyte 55 is supplied so as to flow through the space between the auxiliary anode 58 and the aluminum sheet W.

[0139] <Alkaline etching treatment> In the method for producing an aluminum support of the present invention, it is preferable to carry out an alkali etching treatment after the mechanical graining treatment when the above-mentioned mechanical graining treatment is carried out, or before or after the above-mentioned hydrochloric acid electrolytic treatment step. The alkaline etching treatment, which is carried out before the hydrochloric acid electrolysis treatment, is carried out to remove rolling oil, dirt, and natural oxide films from the surface of the aluminum base material (rolled aluminum) if no mechanical roughening treatment has been performed, or to dissolve the edges of the irregularities created by the mechanical roughening treatment and turn the sharp irregularities into a smoothly undulating surface if the aluminum base material has already been mechanically roughened.

[0140] If mechanical roughening is not performed before the alkaline etching treatment, the etching amount is 0.1 to 10 g / m 2 It is preferable that the density is 1 to 5 g / m 2 It is more preferable that the etching amount is 1 to 10 g / m 2 In this case, rolling oil, dirt, natural oxide film, etc. on the surface can be sufficiently removed.

[0141] When mechanical roughening is performed before alkaline etching, the etching amount is 3 to 20 g / m 2 It is preferable that the density is 5 to 15 g / m 2 It is more preferable that:

[0142] The alkaline etching treatment carried out immediately after the hydrochloric acid electrolysis is carried out for the purposes of dissolving the smut formed in the acidic electrolyte and dissolving the edges of the irregularities formed by the hydrochloric acid electrolysis. The irregularities formed by the hydrochloric acid electrolysis differ depending on the type of electrolyte, and therefore the optimal etching amount also differs. However, the etching amount for the alkaline etching treatment carried out after the hydrochloric acid electrolysis is 0 to 0.5 g / m. 2 It is preferable that the content is 0 to 0.3 g / m 2 It is more preferable that:

[0143] Examples of alkalis used in the alkaline solution include caustic alkalis and alkali metal salts. In particular, an aqueous solution of caustic soda is preferred.

[0144] The concentration of the alkaline solution can be determined depending on the etching amount, but is preferably 1 to 50 mass %, more preferably 10 to 35 mass %. When aluminum ions are dissolved in the alkaline solution, the concentration of the aluminum ions is preferably 0.01 to 10 mass %, more preferably 3 to 8 mass %. The temperature of the alkaline solution is preferably 20 to 90°C. The treatment time is preferably 0 to 120 seconds.

[0145] Examples of methods for contacting an aluminum substrate with an alkaline solution include a method of passing the aluminum substrate through a tank containing the alkaline solution, a method of immersing the aluminum substrate in a tank containing the alkaline solution, and a method of spraying the alkaline solution onto the surface of the aluminum substrate.

[0146] <Desmutting treatment> In the method for producing an aluminum support of the present invention, after the hydrochloric acid electrolysis or alkali etching treatment, pickling (desmutting treatment) is preferably carried out to remove corrosive organisms remaining on the surface. The acids that are generally used include, for example, nitric acid, sulfuric acid, and hydrochloric acid, but other acids may also be used. The desmutting treatment is carried out, for example, by bringing the aluminum substrate into contact with an acid solution of hydrochloric acid, nitric acid, sulfuric acid, or the like having a concentration of 0.5 to 30 mass % (containing 0.01 to 5 mass % aluminum ions). Examples of methods for contacting an aluminum substrate with an acidic solution include a method of passing the aluminum substrate through a tank containing the acidic solution, a method of immersing the aluminum substrate in a tank containing the acidic solution, and a method of spraying the acidic solution onto the surface of the aluminum substrate. The surface condition of the aluminum substrate after desmutting treatment affects the subsequent growth of a natural oxide film, so the choice of acid, its concentration, and temperature conditions are appropriately selected depending on the purpose.

[0147] <Washing treatment> In the method for producing an aluminum support of the present invention, it is preferable to carry out water rinsing after the completion of each of the above-mentioned treatment steps. In particular, water rinsing carried out at the end of the steps should be carried out thoroughly using pure water, well water, tap water, or the like, since this affects the subsequent growth of a natural oxide film.

[0148] <Anodizing process> The anodizing treatment step is a step in which the roughened aluminum plate is anodized after the hydrochloric acid electrolytic treatment step described above, to form an anodized aluminum film on the aluminum plate. The procedure for the anodizing treatment step is not particularly limited, and may be any known method. In the anodizing treatment step, an aqueous solution of sulfuric acid, phosphoric acid, oxalic acid, etc. can be used as the electrolytic bath. For example, the concentration of sulfuric acid can be 100 to 300 g / L. The conditions for anodizing treatment are appropriately set depending on the electrolyte used, but for example, the solution temperature is 5 to 70°C (preferably 10 to 60°C), the current density is 0.5 to 60 A / dm 2 (Preferably 5 to 60A / dm 2 ), voltage 1 to 100 V (preferably 5 to 50 V), electrolysis time 1 to 100 seconds (preferably 5 to 60 seconds), and coating amount 0.1 to 5 g / m 2 (Preferably 0.2 to 3 g / m 2) are mentioned.

[0149] In the present invention, in order to further increase the adhesion between the aluminum support and the image recording layer, the anodizing treatment step is preferably a step in which anodizing treatment is carried out using phosphoric acid.

[0150] <Porewide processing process> The pore widening treatment step is a treatment (pore diameter enlargement treatment) in which the aluminum plate on which the anodized film has been formed is subjected to an etching treatment after the anodized treatment step described above, thereby enlarging the diameter of the micropores in the anodized film. The pore widening treatment can be carried out by contacting the aluminum plate obtained by the above-mentioned anodizing treatment step with an acid aqueous solution or an alkaline aqueous solution. The contacting method is not particularly limited, and examples thereof include a dipping method and a spraying method.

[0151] [Method of manufacturing a lithographic printing plate precursor] The method for producing the lithographic printing plate precursor of the present invention described above is preferably a method in which the following steps are carried out in this order following the method for producing the aluminum support of the present invention described above. (Undercoat layer forming step) A step of forming an undercoat layer on the aluminum support obtained in the pore widening treatment step. (Image recording layer forming process) A process of forming an image recording layer on the undercoat layer The procedure for each step will be described in detail below.

[0152] <Undercoat layer formation process> The undercoat layer forming step is a step of forming an undercoat layer on the aluminum support obtained in the pore widening treatment step. The method for producing the undercoat layer is not particularly limited, and examples thereof include a method in which a coating liquid for forming the undercoat layer containing a predetermined compound (e.g., a compound having a betaine structure) is applied onto the anodized film of the aluminum support. The coating liquid for forming the undercoat layer preferably contains a solvent, such as water or an organic solvent. The coating liquid for forming the undercoat layer can be applied by any of various known methods, such as bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating. The coating amount (solid content) of the primer layer is 0.1 to 100 mg / m 2 is preferred.

[0153] <Image recording layer forming step> The image recording layer forming step is a step of forming an image recording layer on the undercoat layer. The method for forming the image recording layer is not particularly limited, and examples thereof include a method in which a coating liquid for forming the image recording layer containing predetermined components (such as the above-mentioned infrared absorber, polymerization initiator, polymerizable compound, etc.) is applied onto the undercoat layer. The coating liquid for forming the image recording layer preferably contains a solvent, such as water or an organic solvent. The coating liquid for forming the image recording layer can be applied by the methods exemplified above as the coating liquid for forming the undercoat layer. The coating amount (solid content) of the image recording layer varies depending on the application, but is generally 0.3 to 3.0 g / m 2 is preferred.

[0154] When a protective layer is provided on the image recording layer, the method for producing the protective layer is not particularly limited, and examples thereof include a method in which a coating liquid for forming a protective layer containing predetermined components is applied onto the image recording layer.

[0155] In the above embodiment, the micropores 22a in the anodized coating 20a are described as having a substantially straight tubular shape, but the micropores may have other structures as long as the average diameter of the micropores on the surface of the anodized coating falls within a predetermined range. For example, as shown in FIG. 5, an aluminum support 12b may include an aluminum plate 18 and an anodized film 20b having micropores 22b each consisting of a large diameter pore portion 24 and a small diameter pore portion . The micropores 22b in the anodized film 20b are composed of large-diameter pores 24 that extend from the surface of the anodized film to a depth of 10 to 1000 nm (depth D: see Figure 5), and small-diameter pores 26 that communicate with the bottoms of the large-diameter pores 24 and extend from the communicating position to a depth of 20 to 2000 nm. The large diameter hole portion 24 and the small diameter hole portion 26 will be described in detail below.

[0156] The average diameter of the large diameter pores 24 on the surface of the anodized coating 20b is the same as the average diameter of the micropores 22a in the anodized coating 20a on the surface of the anodized coating, and is preferably 10 to 100 nm. From the viewpoint of a balance between stain resistance and image visibility, the average diameter is more preferably 15 to 100 nm, even more preferably 15 to 60 nm, particularly preferably 20 to 50 nm, and particularly preferably 25 to 40 nm. The method for measuring the average diameter of the large diameter pores 24 on the surface of the anodized film 20b is the same as the method for measuring the average diameter of the micropores 22a in the anodized film 20a on the surface of the anodized film.

[0157] The bottoms of the large diameter holes 24 are located at a depth of 10 to 1000 nm (hereinafter also referred to as depth D) from the surface of the anodized film. That is, the large diameter holes 24 are holes extending 10 to 1000 nm in the depth direction (thickness direction) from the surface of the anodized film. The depth is preferably 10 to 200 nm. The depth is determined by taking a photograph (150,000 times) of the cross section of the anodic oxide coating 20b, measuring the depth of 25 or more large diameter holes 24, and averaging the measured depth.

[0158] The shape of the large diameter hole portion 24 is not particularly limited, and examples thereof include a substantially straight tube shape (substantially cylindrical shape) and a cone shape whose diameter decreases in the depth direction (thickness direction), with a substantially straight tube shape being preferred.

[0159] As shown in FIG. 5, the small diameter hole portion 26 is a hole portion that communicates with the bottom of the large diameter hole portion 24 and extends further in the depth direction (thickness direction) from the communicating position. The average diameter of the small diameter pores 26 at the communicating positions is smaller than the average diameter of the large diameter pores, and is preferably 13 nm or less. Of these, 11 nm or less is preferable, and 10 nm or less is more preferable. There is no particular lower limit, but it is often 5 nm or more.

[0160] The average diameter of the small-diameter pores 26 was 400 × 600 nm in the four images obtained by observing the surface of the anodized film 20a with an FE-SEM at a magnification of 150,000 times (N=4). 2 This is the average value obtained by measuring the diameters of 50 micropores (small-diameter pores) present in the range of 100 to 1500. If the large-diameter pores are deep, the upper part of the anodized coating 20b (the region where the large-diameter pores are located) may be cut (for example, with argon gas) as necessary, and then the surface of the anodized coating 20b may be observed with the FE-SEM to determine the average diameter of the small-diameter pores. If the shape of the small-diameter hole 26 is not circular, the equivalent circle diameter is used. The "equivalent circle diameter" 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.

[0161] The bottoms of the small diameter holes 26 are located at positions extending 20 to 2000 nm in the depth direction from the positions where the small diameter holes 26 communicate with the large diameter holes 24. In other words, the small diameter holes 26 are holes that extend in the depth direction (thickness direction) from the positions where the small diameter holes 26 communicate with the large diameter holes 24, and the depth of the small diameter holes 26 is 20 to 2000 nm. The depth is preferably 500 to 1500 nm. The depth is determined by taking a photograph (50,000 times) of the cross section of the anodic oxide coating 20b, measuring the depth of 25 or more small diameter holes, and averaging the measured depth.

[0162] The shape of the small diameter hole 26 is not particularly limited, and examples thereof include a substantially straight tube shape (a substantially cylindrical shape) and a conical shape whose diameter decreases in the depth direction, with a substantially straight tube shape being preferred.

[0163] The method for producing the aluminum support 12b is not particularly limited, but a preferred method is to carry out the following steps in order. (Hydrochloric acid electrolysis process) A process of subjecting an aluminum plate to the above-mentioned hydrochloric acid electrolysis process. (First anodizing process) A process of anodizing the roughened aluminum plate (Pore widening process) A process in which the aluminum plate having the anodized film obtained in the first anodizing process is brought into contact with an acidic or alkaline aqueous solution to widen the diameter of the micropores in the anodized film. (Second anodizing process) A process of anodizing the aluminum plate obtained in the pore widening process The procedure of each step can be determined by referring to a known method.

[0164] Furthermore, in FIG. 1, an embodiment using the undercoat layer 14 has been described, but as mentioned above, the undercoat layer does not have to be included in the lithographic printing plate precursor. When no undercoat layer is provided, the image recording layer may be formed after the aluminum support is subjected to a hydrophilization treatment. Examples of hydrophilization treatment include known methods disclosed in paragraphs

[0109] to

[0114] of JP-A No. 2005-254638. Among these, preferred hydrophilization treatments include immersion in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or application of a hydrophilic vinyl polymer or hydrophilic compound to form a hydrophilic undercoat layer. The hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate can be carried out according to the method and procedure described in US Pat. Nos. 2,714,066 and 3,181,461.

[0165] [Method of manufacturing lithographic printing plates] Next, a method for producing a lithographic printing plate using the lithographic printing plate precursor will be described. A method for producing a lithographic printing plate usually includes an exposure step in which a lithographic printing plate precursor is imagewise exposed (imagewise exposure) to form exposed and unexposed areas, and a step in which the unexposed areas of the imagewise exposed lithographic printing plate precursor are removed. More specifically, one embodiment of the method for producing a lithographic printing plate includes an exposure step in which a lithographic printing plate precursor is imagewise exposed (imagewise exposure) to form exposed areas and unexposed areas, and a removal step in which the unexposed areas of the lithographic printing plate precursor are removed with a developer having a pH of 2 to 12. Another embodiment of the method for producing a lithographic printing plate includes an exposure step in which a lithographic printing plate precursor is exposed imagewise (imagewise exposure) to form exposed areas and unexposed areas, and an on-press development step in which at least one of printing ink and fountain solution is supplied to remove the unexposed areas of the imagewise exposed lithographic printing plate precursor on the printing press. These aspects will be described in detail below.

[0166] The method for producing a lithographic printing plate includes a step of imagewise exposing the lithographic printing plate precursor to light (imagewise exposure). Imagewise exposure is carried out, for example, by laser exposure through a transparent original having a line image or a halftone dot image, or by laser light scanning using digital data. The wavelength of the light source is preferably 750 to 1400 nm. When the light source emits light with a wavelength of 750 to 1400 nm, an image recording layer containing an infrared absorber that is a sensitizing dye that has absorption in this wavelength range is preferably used. Examples of light sources that emit light with a wavelength of 750 to 1400 nm include solid-state lasers and semiconductor lasers that emit infrared rays. With regard to infrared lasers, the output is preferably 100 mW or more, the exposure time per pixel is preferably 20 microseconds or less, and the amount of irradiation energy is 10 to 300 mJ / cm. 2 It is preferable to use a multi-beam laser device in order to shorten the exposure time. The exposure mechanism may be any of an internal drum type, an external drum type, and a flatbed type. Imagewise exposure can be carried out by a conventional method using a platesetter, etc. In the case of an on-press development method described later, the lithographic printing plate precursor may be mounted on a printing press and then imagewise exposed on the printing press.

[0167] The image-exposed lithographic printing plate precursor is developed by either a method in which the unexposed areas are removed with a developer of pH 2 to 12 (developer processing method), or a method in which the unexposed areas are removed on the printing press with at least one of printing ink and fountain solution (on-press development method).

[0168] <Developer processing method> In the developer processing method, the image-exposed lithographic printing plate precursor is processed with a developer having a pH of 2 to 14, and the image recording layer in the unexposed areas is removed to produce a lithographic printing plate. The developer preferably contains a compound (specific compound) having at least one acid group selected from the group consisting of a phosphoric acid group, a phosphonic acid group, and a phosphinic acid group, and one or more carboxyl groups, and has a pH of 5 to 10.

[0169] Examples of the developing method include manual processing, in which a sponge or absorbent cotton is sufficiently soaked in developer, the entire lithographic printing plate precursor is rubbed with the developer, and then thoroughly dried after processing. In the case of immersion processing, for example, the lithographic printing plate precursor is immersed in a vat or deep tank containing developer for about 60 seconds, agitated, and then thoroughly dried while rubbing the lithographic printing plate precursor with absorbent cotton or a sponge.

[0170] For the development process, it is preferable to use an apparatus with a simplified structure and process. In conventional development processing, the protective layer is removed in a pre-washing step, then development is carried out with an alkaline developer, followed by post-washing to remove the alkali, gumming in a gumming step, and drying in a drying step. Development and gumming can be carried out simultaneously using one solution. As the gum, a polymer is preferred, and a water-soluble polymer compound and a surfactant are more preferred. Furthermore, it is preferable to simultaneously remove the protective layer, develop, and gum the film using one solution without performing a pre-washing step. After development and gumming, it is preferable to remove excess developer using a squeeze roller, followed by drying.

[0171] This treatment may be a method of immersing the substrate in the developer once or twice or more times, of which the method of immersing the substrate in the developer once or twice is preferred. The immersion may be performed by passing the exposed lithographic printing plate precursor through a developer tank filled with the developer, or by spraying the developer onto the surface of the exposed lithographic printing plate precursor using a spray or the like. In addition, even if the film is immersed in the developer more than once, if the film is immersed more than once in the same developer, or in a developer and a developer (fatigue solution) in which the components of the image recording layer have been dissolved or dispersed by the development process, this is called a single-liquid development process (single-liquid process).

[0172] In the development process, it is preferable to use a rubbing member, and it is preferable to place a rubbing member such as a brush in the development bath for removing the non-image areas of the image recording layer. Development processing 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 precursor in a developer and rubbing it with a brush, or by pumping up the processing solution from an external tank and spraying it from a spray nozzle and rubbing it with a brush. These development processes can also be carried out multiple times in succession. For example, development processing can be carried out by pumping up the developer from an external tank and spraying it from a spray nozzle and rubbing it with a brush, and then spraying the developer from the spray nozzle again and rubbing it with a brush. When development processing is carried out using an automatic developing machine, the developer becomes fatigued as the processing volume increases, so it is preferable to restore processing capacity by using a replenisher or fresh developer.

[0173] The development process of the present disclosure can also use gum coaters and automatic processors conventionally known for PS (presensitized plate) and CTP (computer-to-plate) printing. When using an automatic processor, any of the following methods can be used: a developer stored in a developer tank or an external tank is pumped up with a pump and sprayed from a spray nozzle; a processing method in which the printing plate is immersed and transported in a tank filled with developer using submerged guide rolls or the like; or a so-called disposable processing method in which essentially unused developer is supplied in the amount required for each plate. In any of these methods, a rubbing mechanism using a brush, moulton, or the like is preferred. For example, commercially available automatic processors (Clean Out Unit C85 / C125, Clean-Out Unit+ C85 / 120, FCF 85V, FCF 125V, FCF News (manufactured by Glunz & Jensen)), and Azura CX85, Azura CX125, Azura CX150 (manufactured by AGFA GRAPHICS) can be used. It is also possible to use a device in which the laser exposure unit and automatic processor unit are integrated.

[0174] <On-press development method> In the on-press development method, the image-exposed lithographic printing plate precursor is supplied with printing ink and dampening water on a printing press to remove the image recording layer in the non-image areas, thereby producing a lithographic printing plate. That is, after imagewise exposure, a lithographic printing plate precursor is either mounted on a printing press as is without any developer treatment, or mounted on a printing press and imagewise exposed on the press, and then printing is performed by supplying printing ink and fountain solution. In the early stages of printing, the supplied printing ink and / or fountain solution dissolves or disperses the image-recording layer in the unexposed areas of the non-image areas, thereby exposing a hydrophilic surface in those areas. Meanwhile, in the exposed areas, the image-recording layer hardened by exposure forms an oil-based ink-receptive area with an oleophilic surface. Either printing ink or fountain solution may be supplied first to the plate surface; however, it is preferable to supply printing ink first to prevent the fountain solution from being contaminated by the removed image-recording layer components. In this way, the lithographic printing plate precursor is developed on the press and used as is for printing a large number of sheets. That is, one embodiment of the printing method of the present invention includes an exposure step of exposing the lithographic printing plate precursor imagewise to light to form exposed areas and unexposed areas, and a printing step of supplying at least one of printing ink and fountain solution to remove the unexposed areas of the imagewise exposed lithographic printing plate precursor on the press, thereby carrying out printing.

[0175] In the method for producing a lithographic printing plate from a lithographic printing plate precursor according to the present invention, regardless of the development method, the entire surface of the lithographic printing plate precursor may be heated, if necessary, before image exposure, during image exposure, or between image exposure and development processing. [Example]

[0176] The features of the present invention will be explained in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[0177] [Production of aluminum support] An aluminum support was manufactured by subjecting a 0.3 mm thick aluminum plate (aluminum alloy plate) made of material 1S to the following treatments. Note that water rinsing was performed between all treatment steps, and after each water rinsing treatment, the plate was drained using nip rollers.

[0178] [Example 1] <Alkaline etching treatment> An aluminum plate was etched by spraying an aqueous solution of caustic soda with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass onto the plate at a temperature of 70°C. The plate was then rinsed with water using a spray. The amount of dissolved aluminum on the surface to be subsequently subjected to electrochemical graining treatment was 5 g / m. 2 It was.

[0179] <Desmutting treatment using an acidic aqueous solution> Next, a desmutting treatment was carried out using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate and the desmutting treatment was carried out for 3 seconds. The acidic aqueous solution used for the desmutting treatment was an aqueous solution containing 150 g / L of sulfuric acid. The liquid temperature was 30°C.

[0180] <Electrochemical roughening treatment> Next, electrochemical graining treatment was performed using an electrolytic solution with a hydrochloric acid concentration of 13 g / L, an aluminum ion concentration of 15 g / L, and a sulfuric acid concentration of 1.0 g / L, using an alternating current. The temperature of the electrolytic solution was 25°C. The aluminum ion concentration was adjusted by adding aluminum chloride. The AC waveform is a sine wave with symmetrical positive and negative waveforms, the frequency is 50 Hz, the anode reaction time and cathode reaction time in one AC cycle are 1:1, and the current density is 35 A / dm at the peak current value of the AC waveform. 2 The total amount of electricity that the aluminum plate takes in the anode reaction is 300 C / dm 2 The electrolytic treatment is 75C / dm 2 The test was carried out four times, with a 2.5-second interval between each test. A carbon electrode was used as the counter electrode for the aluminum plate. The plate was then washed with water.

[0181] <Alkaline etching treatment> After electrochemical graining, the aluminum plate was etched by spraying an aqueous solution of caustic soda containing 5% by mass of caustic soda and 0.5% by mass of aluminum ions at 45°C. The amount of dissolved aluminum on the electrochemically grained surface was 0.2 g / m. 2 After that, a water washing treatment was carried out.

[0182] <Desmutting treatment using an acidic aqueous solution> Next, a desmutting treatment was carried out using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate for 3 seconds. The acidic aqueous solution used for the desmutting treatment had a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L. The liquid temperature was 35°C.

[0183] <First stage anodizing treatment> The first stage of anodizing treatment was carried out using a DC electrolysis anodizing apparatus with the structure shown in Figure 6. Anodizing treatment was carried out using an electrolyte (aqueous solution) containing sulfuric acid under the conditions shown in Table 1, and an anodized film of a predetermined thickness was formed. The "Electrolyte concentration (g / L)" column in Table 1 indicates the concentration of sulfuric acid. In an anodizing treatment apparatus 610 shown in Fig. 6, an aluminum sheet 616 is transported as indicated by the arrow in Fig. 6. In a power supply tank 612 containing an electrolytic solution 618, the aluminum sheet 616 is positively charged by a power supply electrode 620. The aluminum sheet 616 is then transported upward in the power supply tank 612 by rollers 622, redirected downward by nip rollers 624, transported toward an electrolytic treatment tank 614 containing an electrolytic solution 626, and redirected horizontally by rollers 628. The aluminum sheet 616 is then negatively charged by an electrolytic electrode 630, thereby forming an anodized film on its surface, and the aluminum sheet 616 leaves the electrolytic treatment tank 614 and is transported to a subsequent process. In the anodizing apparatus 610, a direction changing means is formed by rollers 622, nip rollers 624, and rollers 628, and the aluminum sheet 616 is transported in a mountain shape and an inverted U shape by rollers 622, nip rollers 624, and rollers 628 in the area 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 disposed between the power supply tank 612 and the electrolytic treatment tank 614.

[0184] <Pore-wide processing> The anodized aluminum plate was immersed in an aqueous solution of caustic soda with a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass at 40° C. to perform a pore widening treatment, and then rinsed with water by spraying.

[0185] <Second stage anodizing treatment> The second stage of anodizing treatment was carried out using a direct current electrolysis anodizing apparatus with the structure shown in Figure 6. Anodizing treatment was carried out using an electrolyte (aqueous solution) containing sulfuric acid under the conditions shown in Table 1 to form an anodized film with a specified thickness, thereby producing an aluminum support. The "Electrolyte concentration (g / L)" column in Table 1 indicates the concentration of sulfuric acid.

[0186] <Examples 2 to 35 and Comparative Examples 1 to 4> An aluminum support was produced in the same manner as in Example 1, except that the temperature of the electrolytic solution, the current density (peak current value of the AC current waveform, total amount of electricity), anodizing conditions, and pore widening conditions in the <electrochemical graining treatment> in Example 1 were changed as shown in Table 1.

[0187] [Table 1]

[0188] For the prepared aluminum support, the density of the first specified recesses, the density of the second specified recesses, the area ratio of the specified protrusions, the surface area ratio ΔS, and the surface roughness Ra on the surface opposite the aluminum plate side of the anodized coating were measured by the methods described above. The results are shown in Table 3 below. Furthermore, for the aluminum supports thus prepared, the average diameter of the large pores in the micropore-containing anodized film at the surface of the anodized film (surface average diameter), the average diameter at the connecting positions of the small pores (internal average diameter), and the depths of the large and small pores were measured using the methods described above. The results are shown in Table 3 below.

[0189] An undercoat layer was formed on the anodized film surface of each aluminum support prepared above using any one of undercoat layer coating solutions 1 to 3 described below, and an image recording layer was formed on the formed undercoat layer using any one of image recording layer coating solutions 1 to 3 described below. The combinations of the undercoat layer coating liquid and the image recording layer coating liquid used are as shown in Table 2. As shown in Table 2 below, in the cases of formulations B to D, a protective layer coating liquid was further used to form a coating layer on the image recording layer. The formulations used in each of the Examples and Comparative Examples are shown in Table 3 below. The "Undercoat layer coating liquid" column in Table 2 indicates the type of undercoat layer coating liquid used, with "1" representing undercoat layer coating liquid 1, "2" representing undercoat layer coating liquid 2, and "3" representing undercoat layer coating liquid 3. The "Image recording layer coating liquid" column in Table 2 indicates the type of image recording layer coating liquid used, with "1" representing image recording layer coating liquid 1, "2" representing image recording layer coating liquid 2, and "3" representing image recording layer coating liquid 3. The "protective layer coating liquid" column in Table 2 indicates the type of protective layer coating liquid used, with "1" indicating protective layer coating liquid 1 and "-" indicating that no protective layer coating liquid was used. For example, as shown in Table 3 described below, Example 1 employed Formulation A, and Formulation A indicates that an undercoat layer was formed using Undercoat Layer Coating Liquid 1, and an image recording layer was formed using Image Recording Layer Coating Liquid 1, as shown in Table 2. The procedure for forming each layer will be described in detail later.

[0190] [Table 2]

[0191] [Formation of primer layer] On the surface of the anodized film of each aluminum support prepared above, one of the undercoat layer coating solutions 1 to 3 was applied in a dry amount of 100 mg / m 2 The undercoat layer was formed by coating the mixture so that the thickness became

[0192] (Undercoat layer coating solution 1) The following components were mixed to prepare undercoat layer 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 (Emalex 710, manufactured by Nippon Emulsion Co., Ltd.): 0.00159 parts by mass Preservative (BioHope L, manufactured by K.I. Chemical Co., Ltd.): 0.00149 parts by mass ·Water: 2.87190 parts by mass

[0193] P-1 (see structural formula below)

[0194] [ka]

[0195] (Undercoat layer coating liquid 2) The following components were mixed to prepare undercoat layer coating solution 2. ·Compound for undercoat layer (P-1 above, 11% by mass aqueous solution): 0.0788 parts by mass Hydroxyethyldiiminodiacetic acid: 0.0280 parts by mass Sodium ethylenediaminetetraacetate tetrahydrate: 0.0499 parts by mass Surfactant (Emalex (registered trademark) 710, Nippon Emulsion Co., Ltd.): 0.0016 parts by mass Preservative (BioHope L, K.I. Chemical Co., Ltd.): 0.0015 parts by mass ·Water: 2.8701 parts by mass

[0196] (Undercoat layer coating solution 3) The following components were mixed to prepare undercoat layer coating solution 3. ·Compound for undercoat layer (P-1 above, 11% by mass aqueous solution): 0.0788 parts by mass Sodium gluconate: 0.0700 parts by weight Surfactant (Emalex (registered trademark) 710, Nippon Emulsion Co., Ltd.): 0.0016 parts by mass Preservative (BioHope L, K.I. Chemical Co., Ltd.): 0.0015 parts by mass ·Water: 2.8780 parts by mass

[0197] [Formation of image recording layer] Any one of the image recording layer coating solutions 1 to 3 was applied onto the undercoat layer of the aluminum support with a bar, and then dried in an oven at 120°C for 40 seconds to give a dry coating weight of 1.3 g / m 2 An image recording layer of the above formula (1) was formed on the surface of the photosensitive layer, and a lithographic printing plate precursor was obtained.

[0198] (Image recording layer coating liquid 1) The following components were mixed to prepare image recording layer coating solution 1. Infrared absorber (IR-1): 0.02000 parts by mass Color former (S-1): 0.02500 parts by weight Electron-accepting polymerization initiator (Int-1): 0.11000 parts by mass Electron-donating polymerization initiator (TPB): 0.02500 parts by mass ·Polymerizable compound (M-1): 0.27500 parts by mass Anionic surfactant (A-1): 0.00600 parts by mass Fluorine-based surfactant (W-1): 0.00416 parts by mass 2-butanone: 4.3602 parts by mass 1-Methoxy-2-propanol: 4.4852 parts by mass Methanol: 2.2838 parts by mass Microgel liquid 1: 2.3256 parts by mass

[0199] [ka]

[0200] [ka]

[0201] [ka]

[0202] [ka]

[0203] [ka]

[0204] [ka]

[0205] [Method for synthesizing polymerizable compound M-1] A mixed solution of Takenate D-160N (polyisocyanate trimethylolpropane adduct, manufactured by Mitsui Chemicals, Inc., 4.7 parts), Aronix M-403 (manufactured by Toagosei Co., Ltd., in an amount such that the NCO value of Takenate D-160N and the hydroxyl value of Aronix M-403 were 1:1), t-butylbenzoquinone (0.02 parts), and methyl ethyl ketone (11.5 parts) was heated to 65°C. Neostan U-600 (bismuth-based polycondensation catalyst, manufactured by Nitto Kasei Co., Ltd., 0.11 parts) was added to the reaction solution, and the mixture was heated at 65°C for 4 hours. The reaction solution was cooled to room temperature (25°C), and methyl ethyl ketone was added to synthesize a solution of urethane acrylate (corresponding to polymerizable compound M-1) with a solids content of 50% by mass. Using a recycle-type GPC (instrument: LC908-C60, columns: JAIGEL-1H-40 and 2H-40 (manufactured by Japan Analytical Industry Co., Ltd.)), molecular weight fractionation of the urethane acrylate solution was carried out with an eluent of tetrahydrofuran (THF). The weight-average molecular weight was 20,000.

[0206] [Method for synthesizing microgel liquid 1] Microgel 1 was synthesized by the following procedure.

[0207] (Preparation of polyisocyanate compounds) To a suspension containing isophorone diisocyanate (17.78 parts by mass, 80 molar equivalents) and the following polyhydric phenol compound (1) (7.35 parts by mass, 20 molar equivalents) in ethyl acetate (25.31 parts by mass), bismuth tris(2-ethylhexanoate) (Neostan U-600, manufactured by Nitto Kasei Co., Ltd., 0.043 parts by mass) was added and stirred. Once the heat generation subsided, the reaction temperature was set to 50°C, and the mixture was stirred for 3 hours to obtain an ethyl acetate solution (50% by mass) of polyhydric isocyanate compound (1).

[0208] [ka]

[0209] (Preparation of Microgels) The oil phase and aqueous phase components listed below were mixed and emulsified using a homogenizer at 12,000 rpm for 10 minutes. The resulting emulsion was stirred at 45°C for 4 hours, after which a 10% by weight aqueous solution (5.20 g) of 1,8-diazabicyclo[5.4.0]undec-7-ene-octylate (U-CAT SA102, manufactured by San-Apro Co., Ltd.) was added. The mixture was stirred at room temperature for 30 minutes and then allowed to stand at 45°C for 24 hours. The solids concentration was adjusted to 20% by weight using distilled water, yielding Microgel Solution 1. The average particle size was measured by light scattering and found to be 0.28 μm.

[0210] -Oil phase components- (Component 1) Ethyl acetate: 12.0 parts by weight (Component 2) 3.76 parts by mass of an adduct (50% by mass ethyl acetate solution, manufactured by Mitsui Chemicals, Inc.) obtained by adding trimethylolpropane (6 molar equivalents) and xylene diisocyanate (18 molar equivalents) to which one-end methylated polyoxyethylene (1 molar equivalent, number of repeating oxyethylene units: 90) was then added. (Component 3) Polyisocyanate compound (1) (as a 50% by mass solution in ethyl acetate): 15.0 parts by mass (Component 4) 65% by weight ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer Corporation): 11.54 parts by weight (Component 5) 10% ethyl acetate solution of sulfonate surfactant (Paionin A-41-C, manufactured by Takemoto Oil & Fat Co., Ltd.): 4.42 parts by mass

[0211] -Aqueous phase components- Distilled water: 46.87 parts by weight

[0212] (Image recording layer coating liquid 2) Image recording layer coating solution 2 was prepared by mixing the following components. Infrared absorber (IR-1): 0.0203 parts by mass Infrared absorber (IR-2): 0.0068 parts by mass Color former (S-2): 0.0120 parts by weight Color former (S-3): 0.0300 parts by weight Electron-accepting polymerization initiator (Int-1): 0.0981 parts by mass Electron-donating polymerization initiator (TPB): 0.0270 parts by mass ·Polymerizable compound (M-2): 0.3536 parts by mass Tricresyl phosphate: 0.0450 parts by mass Anionic surfactant (A-1): 0.0162 parts by weight Fluorine-based surfactant (W-1): 0.0042 parts by mass 2-butanone: 5.3155 parts by mass 1-Methoxy-2-propanol: 2.8825 parts by mass Methanol: 2.3391 parts by mass Microgel liquid 2: 2.8779 parts by mass

[0213] [ka]

[0214] [ka]

[0215] [Method for synthesizing polymerizable compound (M-2)] A mixed solution of Takenate D-160N (polyisocyanate trimethylolpropane adduct, manufactured by Mitsui Chemicals, Inc., 4.7 parts by mass), Aronix M-403 (manufactured by Toagosei Co., Ltd., in an amount such that the NCO value of Takenate D-160N and the hydroxyl value of Aronix M-403 were 1:1), 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 the mixture was heated at 65°C for 4 hours. The reaction solution was cooled to room temperature (25°C), and methyl ethyl ketone was added to synthesize a solution of polymerizable compound (M-2), a urethane acrylate with a solids content of 50% by mass. Using a recycle-type GPC (instrument: LC908-C60, columns: JAIGEL-1H-40 and 2H-40 (manufactured by Japan Analytical Industry Co., Ltd.)), molecular weight fractionation of the solution of polymerizable compound (M-2) was carried out with an eluent of tetrahydrofuran (THF). The weight-average molecular weight was 20,000.

[0216] [Method for synthesizing microgel liquid 2] -Preparation of oil phase components- 6.66 g of a polyfunctional isocyanate compound (PM-200: manufactured by Wanka Chemical), 5.46 g of a 50% by mass ethyl acetate solution of "Takenate (registered trademark) D-116N (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 dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer), 14.47 g of ethyl acetate, and 0.45 g of Paionin (registered trademark) A-41-C manufactured by Takemoto Oil & Fat Co., Ltd. were mixed and stirred at room temperature (25°C) for 15 minutes to obtain an oil phase component.

[0217] [ka]

[0218] -Preparation of aqueous phase components- As the aqueous phase component, 47.2 g of distilled water was prepared.

[0219] -Microcapsule formation process- The aqueous phase component was added to the oil phase component and mixed, and the resulting mixture was 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 10 minutes. The stirred liquid was then heated to 45°C and stirred for 4 hours while maintaining the liquid temperature at 45°C, thereby distilling off ethyl acetate from the liquid. Next, 5.12 g of a 10% by weight aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-ene-octylate (U-CAT SA102, manufactured by San-Apro Co., Ltd.) was added, stirred for 30 minutes at room temperature, and allowed to stand at 45°C for 24 hours. The solids concentration was adjusted to 20% by weight with distilled water, and microgel liquid 2 was obtained. The volume average particle size of the microgel in microgel liquid 2 was measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.) and found to be 165 nm.

[0220] (Image recording layer coating liquid 3) The following components were mixed to prepare image recording layer coating solution 3. Infrared absorber (IR-1): 0.0203 parts by mass Infrared absorber (IR-2): 0.0068 parts by mass Color former (S-2): 0.0120 parts by weight Color former (S-3): 0.0300 parts by weight Electron-accepting polymerization initiator (Int-1): 0.0981 parts by mass Electron-donating polymerization initiator (TPB): 0.0270 parts by mass ·Polymerizable compound (M-2): 0.3536 parts by mass Tricresyl phosphate: 0.0125 parts by weight Anionic surfactant (A-1): 0.0162 parts by weight Paionin A-41-C (Takemoto Oil & Fat, 70% methanol solution): 0.0081 parts by weight Fluorine-based surfactant (W-1): 0.0042 parts by mass 2-butanone: 5.3155 parts by mass 1-Methoxy-2-propanol: 2.8825 parts by mass Methanol: 2.3391 parts by mass Microgel liquid 2: 2.8779 parts by mass

[0221] [Protective layer formation] The protective layer coating solution 1 was applied onto the image recording layer of the aluminum support with a bar, and then dried in an oven at 120°C for 60 seconds to give a dry coating amount of 0.80 g / m 2 A protective layer of

[0222] (Protective layer coating solution 1) Protective layer coating solution 1 was prepared by mixing the following components. ·Water: 1.0161 parts by mass ·Metrose SM04: 0.0600 parts by mass ·FS-102 (17% aqueous dispersion): 0.1177 parts by mass Rapisol A-80 (80% aqueous solution): 0.0063 parts by weight

[0223] [Evaluation method] <Oil-based cleaner print durability> The lithographic printing plate precursors obtained in each of the Examples and Comparative Examples were exposed using a Luxel PLATESETTER T-6000III equipped with an infrared semiconductor laser manufactured by Fujifilm Corporation under conditions of an outer drum rotation speed of 1000 rpm, a laser output of 70%, and a resolution of 2400 dpi. The exposed image included a solid image and a 50% halftone dot chart of a 20 μm dot FM (Frequency Modulation) screen. The resulting exposed lithographic printing plate precursor was mounted on the plate cylinder of a Komori Corporation LITHRONE 26 printing press without any development process. Using a 2:98 (volume) dampening solution of Ecology-2 (Fujifilm Corporation) / tap water and Values-G(N) black ink (Dainippon Ink and Chemicals, Inc.), the dampening solution and ink were supplied using the LITHRONE 26's standard automatic printing start method, and the plate was developed on-press. Printing was then carried out on Tokubishi Art (76.5 kg) paper at a printing speed of 10,000 sheets per hour. As the number of prints increased, the image-recording layer gradually wore away, resulting in a decrease in ink density on the prints. The reference print count was the number of prints at which the density of the solid image began to fade visually. Next, the number of prints was determined in the same manner as above, except that the plate surface was wiped with a cleaner (Fujifilm Corporation, Multi-Cleaner) every 5,000 prints, at which it was visually recognized that the density of the solid image had begun to thin. The number of prints obtained was taken as the number of prints for evaluation. Next, an index value was calculated using the reference number of printed sheets and the evaluation number of printed sheets according to the following formula (X), and evaluation was performed according to the following criteria. Formula (X): Index value = (reference number of prints - evaluation number of prints) / reference number of prints The larger the index value, the smaller the change in printing durability even when a process of wiping the plate surface with a cleaner is added, and the better the printing durability with oil-based cleaner. -Evaluation criteria- 6: The index value is 98% or more but less than 100% 5: The index value is 95% or more but less than 98% 4: The index value is between 80% and 95% 3: The index value is between 60% and 80% 2: The index value is between 40% and 60% 1: Index value is less than 40%

[0224] In Table 3, "First specific recess (number / mm 2 ) column indicates the density of the first specific recesses (pieces / mm 2 ) In Table 3, "Second specific recesses (number / mm 2) column indicates the density of the second specific recesses (pieces / mm 2 ) In Table 3, the column "area ratio (%) of specific convex portions" indicates the area ratio (%) of specific convex portions.

[0225] [Table 3]

[0226] As shown in Table 3 above, it was confirmed that the desired effects were obtained in the case of the lithographic printing plate precursor of the present invention. From a comparison of Examples 1 to 5, the number of first specific recesses was 6000 / mm 2 More than 8000 pieces / mm 2 In the above cases, it was confirmed that the effect was superior. A comparison between Examples 5 and 6 confirmed that a more excellent effect was achieved when the area ratio of the specific convex portions was 10% or less (preferably 8% or less). A comparison between Examples 7 and 8 confirmed that a more excellent effect was achieved when the area ratio of the specific convex portions was 13% or less. Furthermore, a comparison between Example 8 and Examples 9 and 10 confirmed that a more excellent effect was achieved when the area ratio of the specific convex portions was 10% or less. Furthermore, a comparison between Examples 9 and 10 and Example 12 confirmed that a more excellent effect was achieved when the area ratio of the specific convex portions was less than 3%. In addition, the evaluation of oil-based cleaner printing durability was "5" for both Examples 9 and 11. In Example 11, the number of first specific recesses was 6000 / mm 2 The number of second specific convex portions is less than 6000 / mm 2 Therefore, Examples 9 and 11 were evaluated as being the same. 2 It was confirmed that the effect was even better when the above conditions were met. From Examples 12 to 14, the area ratio of the specific convex portions was 10% or less, and the number of the second specific concave portions was 6000 / mm 2 As described above, it was confirmed that the most excellent effect was obtained when the surface area ratio ΔS was 45% or more. From Examples 15 to 19, it was confirmed that a more excellent effect was achieved when the area ratio of the specific convex portions was 10% or less and the surface area ratio ΔS was 20% or more, and further confirmed that a more excellent effect was achieved when the area ratio of the specific convex portions was 10% or less and the surface area ratio ΔS was 45% or more. A comparison between Example 18 and Example 23 confirmed that a more excellent effect was achieved when the area ratio of the specific convex portions was 7% or less and the surface area ratio ΔS was 20% or more. A comparison between Example 15 and Example 20 confirmed that a more excellent effect was achieved when the area ratio of the specific convex portions was 7% or less and the surface area ratio ΔS was 45% or more.

[0227] <Examples 36 to 39> An aluminum support was produced in the same manner as in Example 1, except that the temperature of the electrolytic solution, the current density (peak current value of the AC current waveform, total amount of electricity), anodizing conditions, and pore widening conditions in the <electrochemical graining treatment> in Example 1 were changed as shown in Table 4.

[0228] [Table 4]

[0229] The density of the second specific recesses, the area ratio of the specific protrusions, the surface area ratio ΔS, and the surface roughness Ra of the surface of the anodized coating opposite the aluminum plate side were measured using the methods described above. The results are shown in Table 5 below. Furthermore, for the aluminum supports thus prepared, the average diameter of the large pores in the micropore-containing anodized film at the surface of the anodized film (surface average diameter), the average diameter at the connecting positions of the small pores (internal average diameter), and the depths of the large and small pores were measured using the methods described above. The results are shown in Table 5 below. Using the obtained aluminum support, a lithographic printing plate precursor was prepared by carrying out the above-mentioned procedures of [Formation of undercoat layer] and [Formation of image recording layer], and the <oil-based cleaner printing durability> was evaluated. The results are shown in Table 5 below.

[0230] [Table 5]

[0231] As shown in Table 5 above, it was confirmed that the desired effects were obtained in the case of the lithographic printing plate precursor of the present invention. A comparison between Examples 15 and 16 confirmed that the effect was better when the area ratio of the specific convex portions was 13% or less. Also, a comparison between Examples 16 and 17 confirmed that the effect was better when the area ratio of the specific convex portions was 10% or less. Also, a comparison between Examples 17 and 18 confirmed that the effect was better when the area ratio of the specific convex portions was less than 3%. [Explanation of symbols]

[0232] ta Anode reaction time tc cathode reaction time tp Time it takes for the current to reach its peak from 0 Ia Peak current in the anode cycle Ic Peak current on the cathode cycle side 10 Planographic printing plate original plate 12a, 12b Aluminum support 14 Primer layer 16 Image recording layer 18 Aluminum Plate 20a, 20b Anodic oxide film 22a, 22b Micropore 24 Large diameter hole 26 Small diameter hole 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 equipment 612 Power supply tank 614 Electrolytic treatment tank 616 Aluminum Plate 618,626 Electrolyte 620 Power supply electrode 622,628 Laura 624 Nip Roller 630 Electrolytic electrode 632 Tank wall 634 DC power supply

Claims

1. A lithographic printing plate precursor having an aluminum support and an image recording layer disposed on the aluminum support, the aluminum support includes an aluminum plate and an anodized aluminum coating disposed on the aluminum plate; the image recording layer is disposed on the anodized film side of the aluminum support, a lithographic printing plate precursor, wherein an area ratio of convex portions having a height from the average surface of 0.80 μm or more, as measured by a non-contact three-dimensional roughness meter over an area of ​​400 μm × 400 μm on the surface of the aluminum support on the image recording layer side, is 20% or less.

2. The lithographic printing plate precursor according to claim 1 , wherein the area ratio of the protrusions having a height from the average plane of 0.80 μm or more is 13% or less.

3. The lithographic printing plate precursor according to claim 1 or 2, wherein an area ratio of the protrusions having a height from the average plane of 0.80 μm or more is 10% or less.

4. The lithographic printing plate precursor according to any one of claims 1 to 3, wherein an area ratio of the protrusions having a height from the average plane of 0.80 µm or more is 7% or less.

5. A lithographic printing plate precursor having an aluminum support and an image recording layer disposed on the aluminum support, the aluminum support includes an aluminum plate and an anodized aluminum coating disposed on the aluminum plate; the image recording layer is disposed on the anodized film side of the aluminum support, The density of recesses having a depth of 0.40 μm or more from the average surface, as measured within a 400 μm×400 μm area on the surface of the aluminum support on the side of the image recording layer, is 4,000 / mm ２ This is the lithographic printing plate precursor.

6. The density of the recesses having a depth of 0.40 μm or more from the average surface is 6000 pieces / mm ２ The lithographic printing plate precursor according to claim 5 .

7. The density of the recesses having a depth of 0.40 μm or more from the average surface is 8000 pieces / mm ２ The lithographic printing plate precursor according to claim 5 or 6, wherein

8. The lithographic printing plate precursor according to any one of claims 5 to 7, wherein an area ratio of convex portions having a height from the average plane of 0.80 µm or more, as measured by using a non-contact three-dimensional roughness meter within a 400 µm x 400 µm area on the surface of the aluminum support on the image recording layer side, is 20% or less.

9. The density of recesses having a depth of 0.20 μm or more from the average surface, as measured within a 400 μm×400 μm area on the surface of the aluminum support on the side of the image recording layer, is 6,000 / mm ２ The lithographic printing plate precursor according to any one of claims 1 to 8, wherein

10. The lithographic printing plate precursor according to any one of claims 1 to 9, wherein a surface area ratio ΔS calculated from an actual area Sx determined by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points in an area of ​​25 µm × 25 µm on the surface of the aluminum support on the image recording layer side using an atomic force microscope and a geometrically measured area S0 according to the following formula (1) is 20% or more: ΔS=(Sx-S0) / S0×100(%)...(1)

11. The lithographic printing plate precursor according to claim 10, wherein the surface area ratio ΔS is 25% or more.

12. The lithographic printing plate precursor according to claim 10 or 11, wherein the surface area ratio ΔS is 45% or more.

13. an area ratio of convex portions having a height from the average surface of 0.80 μm or more, as measured by a non-contact three-dimensional roughness meter within a 400 μm × 400 μm area on the surface of the aluminum support on the image recording layer side, is 10% or less; 2. The lithographic printing plate precursor according to claim 1, wherein a surface area ratio ΔS calculated from an actual area Sx determined by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points in a 25 μm × 25 μm area on the surface of the aluminum support on the image recording layer side using an atomic force microscope and a geometrically measured area S0 according to the following formula (1) is 20% or more: ΔS=(Sx-S0) / S0×100(%)...(1)

14. The lithographic printing plate precursor according to claim 13 , wherein the surface area ratio is 45% or more.

15. The lithographic printing plate precursor according to claim 13, wherein an area ratio of the protrusions having a height from the average plane of 0.80 μm or more is 7% or less.

16. The lithographic printing plate precursor according to claim 13, wherein the area ratio of the protrusions having a height from the average plane of 0.80 μm or more is 7% or less, and the surface area ratio is 45% or more.

17. an area ratio of convex portions having a height from the average surface of 0.80 μm or more, as measured by a non-contact three-dimensional roughness meter within a 400 μm × 400 μm area on the surface of the aluminum support on the image recording layer side, is 10% or less; The density of recesses having a depth of 0.20 μm or more from the average surface, as measured within a 400 μm×400 μm area on the surface of the aluminum support on the side of the image recording layer, is 6,000 / mm ２ That's all, 2. The lithographic printing plate precursor according to claim 1, wherein a surface area ratio ΔS calculated from an actual area Sx determined by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points in an area of ​​25 μm × 25 μm on the surface of the aluminum support on the image recording layer side using an atomic force microscope and a geometrically measured area S0 according to the following formula (1) is 45% or more: ΔS=(Sx-S0) / S0×100(%)...(1)

18. The lithographic printing plate precursor according to any one of claims 1 to 17, wherein the surface of the aluminum support on the image recording layer side has a surface roughness Ra of 0.45 µm or less, as measured using a contact surface roughness meter.

19. the anodic oxide coating has micropores, the micropores are composed of large-diameter pores extending from the surface of the anodized coating to a depth of 10 to 1,000 nm, and small-diameter pores communicating with the bottoms of the large-diameter pores and extending from the communicating positions to a depth of 20 to 2,000 nm, the large diameter pores have an average diameter of 15 to 60 nm on the surface of the anodized film; The lithographic printing plate precursor according to any one of claims 1 to 18, wherein the small diameter pores have an average diameter at the communicating position that is smaller than the average diameter of the large diameter pores.

20. an exposure step of imagewise exposing the lithographic printing plate precursor according to any one of claims 1 to 19 to form exposed areas and unexposed areas; a removing step of removing unexposed areas of the imagewise exposed lithographic printing plate precursor.

21. an exposure step of imagewise exposing the lithographic printing plate precursor according to any one of claims 1 to 19 to form exposed areas and unexposed areas; a printing step of supplying at least one of printing ink and dampening water to remove unexposed areas of the imagewise exposed lithographic printing plate precursor on a printing press, thereby carrying out printing.

22. A method for producing an aluminum support used in the lithographic printing plate precursor according to any one of claims 1 to 19, comprising the steps of: For an aluminum plate, in a hydrochloric acid treatment solution which may contain sulfuric acid, the temperature of the hydrochloric acid treatment solution is 30°C or less, and the total amount of electricity is 400 C / dm ２ and the peak current value of the AC current waveform is 80 A / dm ２ The method includes a hydrochloric acid electrolysis step of subjecting an aluminum plate to AC electrolysis to produce a surface-roughened aluminum plate, When the hydrochloric acid treatment solution contains sulfuric acid, the ratio of the content of sulfuric acid to the content of hydrochloric acid is 0.1 or less. Method for producing an aluminum support.

23. After the hydrochloric acid electrolysis treatment step, an anodizing treatment step of anodizing the surface-roughened aluminum plate to form an aluminum anodized film on the aluminum plate; a pore widening treatment step in which the aluminum plate on which the anodized film has been formed is subjected to an etching treatment to enlarge the diameter of the micropores in the anodized film; The method for producing an aluminum support according to claim 22, comprising the steps of:

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