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

Abstract

The present invention provides a lithographic printing plate precursor having excellent oil-based detergent printing durability when formed into a lithographic printing plate, a method for producing a lithographic printing plate, a printing method, and a method for producing an aluminum support. The lithographic printing plate precursor of the present invention comprises an aluminum support and an image-recording layer disposed on the aluminum support. The aluminum support comprises an aluminum plate and an anodic aluminum oxide film disposed on the aluminum plate, and the image-recording layer is disposed on the anodic oxide film side of the aluminum support. The area ratio of protrusions having a height of 0.80 μm or greater from the average surface, measured over a 400 μm x 400 μm area on the image-recording layer side of the aluminum support using a non-contact three-dimensional roughness meter, is 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 Art

[0002] It is known that the surface of an aluminum support used in a lithographic printing plate is frosted (roughened) to give it irregularities in order to improve the stain resistance and printing durability when the lithographic printing plate is produced.

[0003] For example, Patent Document 1 describes a planographic printing plate precursor comprising an aluminum support and an image recording layer disposed on the aluminum support, wherein the aluminum support comprises an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate, the image recording layer is disposed on the anodic oxide film side of the aluminum support, and a density of concave portions having a depth of 0.70 μm or more from a center line, measured over a 400 μm×400 μm area on the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter, is 3000 / mm. 2 above. ".

[0004] Previous technical literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2019 / 087516 Summary of the Invention

[0007] Technical issues to be solved by the invention

[0008] When printing with a lithographic printing plate obtained from a lithographic printing plate precursor, cleaning with a detergent is sometimes performed to remove contamination during printing. Even with this cleaning, it is essential that the printing durability does not decrease. This performance is also referred to as oil-based detergent printing durability.

[0009] 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 oil-based detergents.

[0010] An object of the present invention is to provide a lithographic printing plate precursor having excellent printing durability with an oil-based detergent when produced as a lithographic printing plate.

[0011] Furthermore, an 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.

[0012] Means for solving technical problems

[0013] The present inventors have discovered that the above-mentioned problems can be solved by the following configuration.

[0014] (1) A lithographic printing plate precursor comprising an aluminum support and an image recording layer disposed on the aluminum support, wherein:

[0015] The aluminum support includes an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate.

[0016] The image recording layer is arranged on the anodic oxide film side of the aluminum support.

[0017] The area ratio of projections having a height of 0.80 μm or more from the average surface measured in a 400 μm×400 μm range on the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter was 20% or less.

[0018] (2) The lithographic printing plate precursor according to (1), wherein

[0019] The area ratio of the convex portions having a height of 0.80 μm or more from the average surface is 13% or less.

[0020] (3) The lithographic printing plate precursor according to (1) or (2), wherein

[0021] The area ratio of the convex portions having a height of 0.80 μm or more from the average surface is 10% or less.

[0022] (4) The lithographic printing plate precursor according to any one of (1) to (3), wherein

[0023] The area ratio of the convex portions having a height of 0.80 μm or more from the average surface is 7% or less.

[0024] (5) A planographic printing plate precursor comprising an aluminum support and an image recording layer disposed on the aluminum support, wherein:

[0025] The aluminum support includes an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate.

[0026] The image recording layer is arranged on the anodic oxide film side of the aluminum support.

[0027] The density of recessed portions having a depth of 0.40 μm or more from the average surface was measured in a 400 μm×400 μm area on the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter and was 4000 / mm. 2 above.

[0028] (6) The lithographic printing plate precursor according to (5), wherein

[0029] The density of the recessed portions with a depth of 0.40 μm or more from the average surface is 6000 / mm 2 above.

[0030] (7) The lithographic printing plate precursor according to (5) or (6), wherein

[0031] The density of recesses with a depth of 0.40 μm or more from the average surface is 8000 / mm 2 above.

[0032] (8) The lithographic printing plate precursor according to any one of (5) to (7), wherein

[0033] The area ratio of projections having a height of 0.80 μm or more from the average surface measured in a 400 μm×400 μm range on the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter was 20% or less.

[0034] (9) The lithographic printing plate precursor according to any one of (1) to (8), wherein

[0035] The density of recessed portions having a depth of 0.20 μm or more from the average surface was measured in a 400 μm×400 μm area on the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter and was 6000 / mm. 2 above.

[0036] (10) The lithographic printing plate precursor according to any one of (1) to (9), wherein

[0037] The actual area Sx and the geometrically measured area S0 obtained by the approximate three-point method from the three-dimensional data obtained by measuring 512×512 points in a 25μm×25μm range on the surface of the image recording layer side of the aluminum support using an atomic force microscope, and the surface area ratio ΔS calculated by the formula (1) described later is greater than 20%.

[0038] (11) The lithographic printing plate precursor according to (10), wherein

[0039] The surface area ratio ΔS is 25% or more.

[0040] (12) The lithographic printing plate precursor according to (10) or (11), wherein

[0041] The surface area ratio ΔS is 45% or more.

[0042] (13) The lithographic printing plate precursor according to (1), wherein

[0043] The area ratio of protrusions having a height of 0.80 μm or more from the average surface measured in a 400 μm×400 μm range on the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter was 10% or less.

[0044] The actual area Sx and the geometrically measured area S0 obtained by the approximate three-point method from the three-dimensional data obtained by measuring 512×512 points in a 25μm×25μm range on the surface of the image recording layer side of the aluminum support using an atomic force microscope, and the surface area ratio ΔS calculated by the formula (1) described later is greater than 20%.

[0045] (14) The lithographic printing plate precursor according to (13), wherein

[0046] The surface area ratio is 45% or more.

[0047] (15) The lithographic printing plate precursor according to (13), wherein

[0048] The area ratio of the convex portions having a height of 0.80 μm or more from the average surface is 7% or less.

[0049] (16) The lithographic printing plate precursor according to (13), wherein

[0050] The area ratio of the convex portions having a height of 0.80 μm or more from the average surface is 7% or less, and the surface area ratio is 45% or more.

[0051] (17) The lithographic printing plate precursor according to (1), wherein

[0052] The area ratio of the convex portions having a height of 0.80 μm or more from the average surface, obtained by measuring the surface of the image recording layer side of the aluminum support in an area of ​​400 μm × 400 μm using a non-contact three-dimensional roughness meter, was 10% or less. The density of the concave portions having a depth of 0.20 μm or more from the average surface, obtained by measuring the surface of the image recording layer side of the aluminum support in an area of ​​400 μm × 400 μm using a non-contact three-dimensional roughness meter, was 6000 pieces / mm 2 The actual area Sx and the geometrically measured area S0 obtained by the approximate three-point method based on the three-dimensional data obtained by measuring 512×512 points in a range of 25μm×25μm on the surface of the image recording layer side of the aluminum support using an atomic force microscope, and the surface area ratio ΔS calculated by the formula (1) described later is greater than 45%.

[0053] (18) The lithographic printing plate precursor according to any one of (1) to (17), wherein

[0054] The surface roughness Ra of the image recording layer side surface of the aluminum support was measured using a contact-type surface roughness meter and was found to be 0.45 μm or less.

[0055] (19) The lithographic printing plate precursor according to any one of (1) to (18), wherein

[0056] The anodic oxide film has micropores.

[0057] The micropores are composed of large-diameter pores and small-diameter pores. The large-diameter pores extend from the surface of the anodic oxide film to a depth of 10 to 1000 nm. The small-diameter pores are connected to the bottom of the large-diameter pores and extend from the connected position to a depth of 20 to 2000 nm.

[0058] The average diameter of the large-diameter pores on the surface of the anodic oxide film is 15 to 60 nm.

[0059] The average diameter of the small-diameter hole portion at the communication position is smaller than the average diameter of the large-diameter hole portion.

[0060] (20) A method for manufacturing a lithographic printing plate, comprising:

[0061] an exposure step of exposing the lithographic printing plate precursor according to any one of (1) to (19) in an imagewise manner to form exposed areas and unexposed areas; and

[0062] The removing step removes unexposed areas of the image-wise exposed lithographic printing plate precursor.

[0063] (21) A printing method comprising:

[0064] an exposure step of exposing the lithographic printing plate precursor according to any one of (1) to (19) in an imagewise manner to form exposed areas and unexposed areas; and

[0065] In the printing step, at least one of printing ink and fountain solution is supplied to remove unexposed portions of the image-wise exposed lithographic printing plate precursor on a printing press, and printing is performed.

[0066] (22) A method for producing an aluminum support for use with the planographic printing plate precursor described in any one of (1) to (19), the method comprising:

[0067] In the hydrochloric acid electrolytic treatment process, the aluminum plate is treated in a hydrochloric acid treatment solution which may contain sulfuric acid, at a temperature of 30°C or less and a total charge of 400C / dm 2 Below, and the peak current value of the AC current waveform is 80A / dm 2 Under the following conditions, AC electrolysis was performed to produce a roughened aluminum plate.

[0068] When the hydrochloric acid treatment liquid contains sulfuric acid, the ratio of the content of sulfuric acid to the content of hydrochloric acid is 0.1 or less.

[0069] (23) The method for producing an aluminum support according to (22), wherein

[0070] After the hydrochloric acid electrolysis process, the following steps are included:

[0071] an anodizing step of performing an anodizing treatment on the roughened aluminum plate to form an aluminum anodic oxide film on the aluminum plate; and

[0072] In the pore expansion step, the aluminum plate having the anodic oxide film formed thereon is subjected to an etching process to expand the diameter of the micropores in the anodic oxide film.

[0073] Effects of the Invention

[0074] According to the present invention, it is possible to provide a lithographic printing plate precursor that is excellent in oil-based detergent printing durability when used as a lithographic printing plate.

[0075] Furthermore, according to the present invention, a method for producing a lithographic printing plate, a printing method, and a method for producing an aluminum support can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 This is a schematic cross-sectional view of one embodiment of the lithographic printing plate precursor of the present invention.

[0077] Figure 2 This is a schematic cross-sectional view of one embodiment of an aluminum support.

[0078] Figure 3 This is a graph showing an example of an alternating waveform current waveform used in the electrochemical roughening treatment in the method for producing an aluminum support.

[0079] Figure 4 This is a side view showing an example of a radial type unit in the electrochemical roughening treatment using alternating current in the method for producing an aluminum support.

[0080] Figure 5 It is a schematic cross-sectional view of another embodiment of the aluminum support.

[0081] Figure 6 This is a schematic diagram of an anodizing treatment apparatus used for anodizing treatment in the production of an aluminum support. DETAILED DESCRIPTION

[0082] Hereinafter, the present invention will be described in detail.

[0083] The following description of the constituent elements is based on representative embodiments of the present invention, but the present invention is not limited to these embodiments.

[0084] In addition, in this specification, the numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0085] Furthermore, in this specification, when referring to groups in compounds represented by formulae, if the term "substituted" or "unsubstituted" is not specified, and the group may also have a substituent, unless otherwise specified, the group includes not only unsubstituted groups but also groups with substituents. For example, if a formula contains the statement "R represents an alkyl group, an aryl group, or a heteroatom-containing cyclic group," this means "R represents an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aryl group, a substituted aryl group, an unsubstituted heteroatom-containing cyclic group, or a substituted heteroatom-containing cyclic group."

[0086] A first embodiment of the lithographic printing plate precursor of the present invention is a lithographic printing plate precursor comprising an aluminum support and an image recording layer disposed on the aluminum support, wherein the aluminum support comprises an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate, the image recording layer is disposed on the anodic oxide film side of the aluminum support, and a density of concave portions having a depth of 0.40 μm or greater from an average surface, measured over a 400 μm×400 μm range on the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter, is 4000 / mm 2 above.

[0087] The 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 arranged on the aluminum support. In the above-mentioned lithographic printing plate precursor, the aluminum support includes an aluminum plate and an aluminum anodic oxide film arranged on the aluminum plate, and the image recording layer is arranged on the anodic oxide film side of the aluminum support. Using a non-contact three-dimensional roughness meter, the area ratio of the protrusions with a height of 0.80 μm or more from the average surface is measured in a range of 400 μm×400 μm on the surface of the image recording layer side of the aluminum support, and the area ratio is less than 20%.

[0088] The first embodiment differs from the second embodiment in that the density of recesses having a predetermined depth is defined, while the area ratio of projections having a predetermined height is defined.

[0089] Hereinafter, first, the density of recesses of a predetermined depth in the first embodiment and the area ratio of projections of a predetermined height in the second embodiment, which are characteristic points of each embodiment, will be described.

[0090] [Density of concavities]

[0091] In the first embodiment of the lithographic printing plate precursor of the present invention, the density of the recessed portions having a depth of 0.40 μm or more from the average surface (hereinafter also referred to as “first specific recessed portions”) obtained by measuring the surface of the image recording layer side of the aluminum support in an area of ​​400 μm × 400 μm using a non-contact three-dimensional roughness meter is 4000 pieces / mm 2 above.

[0092] Among them, from the viewpoint of better printing durability of the oil-based detergent (hereinafter also referred to as "the viewpoint of better effect of the present invention"), the density of the first specific recessed portions is preferably 6000 pcs / mm 2 More than 8000 pieces / mm 2 The upper limit of the density of the first specific recessed portions is not particularly limited, but is preferably 20,000 / mm 2 Below, more preferably 16000 pieces / mm 2 the following.

[0093] In the present invention, the density of the first specific recessed portions refers to a value measured as follows.

[0094] First, a non-contact 3D roughness meter (VertScan, manufactured by Ryoka Systems Inc.) was used to scan the image recording layer-side surface of the aluminum support in a non-contact manner at a resolution of 0.01 μm over a 400 μm x 400 μm area to obtain 3D data. The VertScan's instrumentation and measurement conditions are as follows.

[0095] (1) Device content

[0096] CCD camera: Sony HR-57

[0097] Objective lens: ×10

[0098] Lens barrel: ×1

[0099] Wavelength filter: 530white

[0100] (2) Measurement conditions

[0101] Measurement mode: wave

[0102] Field of view: 400μm×400μm

[0103] Scanning range: Start +6μm, End -10μm

[0104] Next, the obtained three-dimensional data were analyzed using software (SX Viewer, manufactured by Ryoka Systems Inc.). The software was selected: "Complete Interpolation" → "Surface Correction Polynomial" → "Quadratic" → "Particle Analysis." The number of concave portions with a depth of 0.40 μm or greater from the average plane was determined. The average plane refers to the plane located at the height obtained by averaging the height values ​​of all measured data on the image recording layer side of the aluminum support within the measurement area (400 μm × 400 μm).

[0105] The measurement was performed at 5 locations per sample, and the number of predetermined concave portions was counted at each location. The average value was then calculated and converted into a value per unit area (μm 2 ) is used as the density of the first specific recess.

[0106] [Area ratio of convex portion]

[0107] In the second embodiment of the lithographic printing plate precursor of the present invention, the area ratio of the protrusions (hereinafter also referred to as "specific protrusions") with a height of 0.80 μm or more from the average surface obtained by measuring the range of 400 μm × 400 μm on the surface of the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter is less than 20%.

[0108] From the perspective of achieving even greater effects of the present invention, the area ratio of the specific protrusions is preferably 13% or less, more preferably 10% or less, even more preferably 8% or less, particularly preferably 7% or less, even more preferably less than 3%, and most preferably 2% or less. The lower limit of the area ratio of the specific protrusions is not particularly limited, but is preferably 0% or more, and more preferably 0.2% or more.

[0109] In the present invention, the area ratio of specific convex portions refers to a value measured as follows.

[0110] First, a non-contact 3D roughness meter (VertScan, manufactured by Ryoka Systems Inc.) was used to scan the image recording layer-side surface of the aluminum support in a non-contact manner at a resolution of 0.01 μm over a 400 μm x 400 μm area to obtain 3D data. The VertScan's instrumentation and measurement conditions are as follows.

[0111] (1) Device content

[0112] CCD camera: Sony HR-57

[0113] Objective lens: ×10

[0114] Lens barrel: ×1

[0115] Wavelength filter: 530white

[0116] (2) Measurement conditions

[0117] Measurement mode: wave

[0118] Field of view: 400μm×400μm

[0119] Scanning range: Start +6μm, End -10μm

[0120] Next, the obtained three-dimensional data were image analyzed using software (SX Viewer, manufactured by Ryoka Systems Inc.), convex portions having a depth of 0.80 μm or greater from the average surface were extracted, and the area ratio of the convex portions within an area of ​​400 μm×400 μm was determined.

[0121] The measurement was performed at five locations per sample, and the area ratio of predetermined convex portions was calculated at each location. The average value of these values ​​was then determined and used as the area ratio of specific convex portions.

[0122] In the first embodiment of the lithographic printing plate precursor of the present invention, the area ratio of the specific protrusions is not particularly limited, but is preferably 20% or less from the viewpoint of achieving a more excellent effect of the present invention. Specifically, in the first embodiment of the lithographic printing plate precursor of the present invention, the density of the first specific concave portions, as measured by a non-contact three-dimensional roughness meter over a 400 μm × 400 μm area on the image-recording layer side of the aluminum support, may be 4,000 / mm. 2 or more, and the area ratio of the specific convex portion may be 20% or less.

[0123] From the perspective of achieving even greater effects of the present invention, the area ratio of the specific projections in the first embodiment of the lithographic printing plate precursor of the present invention is preferably 13% or less, more preferably 10% or less, even more preferably 8% or less, and particularly preferably 7% or less. The lower limit of the area ratio of the specific projections is not particularly limited, but is preferably 0% or more, and more preferably 0.3% or more.

[0124] Furthermore, in the second embodiment of the lithographic printing plate precursor of the present invention, the density of the first specific recessed portions is not particularly limited, but is preferably 4000 / mm2 from the viewpoint of further improving the effects of the present invention. 2 That is, in the second embodiment of the planographic printing plate precursor of the present invention, the area ratio of the specific convex portions may be 20% or less, and the density of the first specific concave portions may be 4000 / mm 2 above.

[0125] From the viewpoint of further improving the effects of the present invention, the density of the first specific recessed portions in the second embodiment of the lithographic printing plate precursor of the present invention is preferably 6000 / mm 2 More than 8000 pieces / mm 2 The upper limit of the density of the first specific recessed portions is not particularly limited, but is preferably 20,000 / mm 2 Below, more preferably 16000 pieces / mm 2 the following.

[0126] Hereinafter, the structure of the planographic printing plate precursor of the present invention will be described in more detail. However, unless otherwise specified, the structure described below is a structure related to both the first embodiment and the second embodiment described above.

[0127] [Density of concavities]

[0128] In the lithographic printing plate precursor of the present invention (the first embodiment and the second embodiment), the density of the recessed portions having a depth of 0.20 μm or more from the average surface (hereinafter also referred to as “second specific recessed portions”) obtained by measuring an area of ​​400 μm × 400 μm on the surface of the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter is not particularly limited, but is generally 3000 / mm 2 From the viewpoint of the better effect of the present invention, 6000 pieces / mm is preferred. 2 More than 8000 pieces / mm 2 The upper limit of the density of the second specific recessed portions is not particularly limited, but is preferably 20,000 / mm 2 Below, more preferably 16000 pieces / mm 2 the following.

[0129] In the method for measuring the above-mentioned second specific recess, first, the measurement is performed under the same conditions using the same non-contact three-dimensional roughness meter (VertScan, manufactured by Ryoka Systems Inc.) as used for measuring the density of the above-mentioned first specific recess, and the obtained three-dimensional data is image analyzed using software (SX Viewer, manufactured by Ryoka Systems Inc.) to calculate the number of recesses with a depth of 0.20 μm or more from the average surface.

[0130] The measurement was performed at 5 locations per sample, and the number of predetermined concave portions was counted at each location. The average value was then calculated and converted into a value per unit area (μm 2 ) is used as the density of the second specific recess.

[0131] [Surface area ratio ΔS]

[0132] In the lithographic printing plate precursor of the present invention (the first embodiment and the second embodiment), from the viewpoint of achieving a more excellent effect of the present invention, the surface area ratio ΔS calculated by the following formula (1) from the actual area Sx obtained by the approximate three-point method based on three-dimensional data obtained by measuring 512 × 512 points in a 25 μm × 25 μm area on the image-recording layer side of the aluminum support using an atomic force microscope and the geometrically measured area S0 is preferably 20% or more, more preferably 25% or more, further preferably 35% or more, and particularly preferably 45% or more. The upper limit of the surface area ratio ΔS is not particularly limited, but is preferably 70% or less, more preferably 60% or less.

[0133] ΔS=(Sx-S0) / S0×100(%)……(1)

[0134] In the present invention, the surface area ratio ΔS refers to a value measured as follows.

[0135] Specifically, the aluminum support is cut into a size of 1 cm square, and is placed on a horizontal sample stage on a piezoelectric scanner. The cantilever is brought close to the sample surface. When the area where the atomic force acts is reached, it is scanned in the XY direction. At this time, the concave and convex of the sample is obtained by the piezoelectric displacement in the Z direction. As for the piezoelectric scanner, a piezoelectric scanner that can scan 150 μm in the XY direction and 10 μm in the Z direction is used. As for the cantilever, a cantilever with a resonant frequency of 130 to 200 kHz and a spring constant of 7 to 20 N / m (OMCL-AC200-TS, manufactured by Olympus Corporation) is used, and the measurement is performed in DFM mode (Dynamic Force Mode). In addition, the slight tilt of the sample is corrected by performing least squares approximation on the obtained three-dimensional data to obtain the reference surface.

[0136] The measurement was performed at 512 x 512 points on a 25 x 25 μm area of ​​the surface. The resolution in the X direction was 0.05 μm, the resolution in the Y direction was 1.9 μm, the resolution in the Z direction was 1 nm, and the scanning speed was 18 μm / sec.

[0137] [Surface roughness Ra]

[0138] In the lithographic printing plate precursor of the present invention (the first embodiment and the second embodiment), the surface roughness Ra obtained by measuring the surface of the image recording layer side of the aluminum support using a contact surface roughness meter is not particularly limited, but is generally 0.50 μm or less. From the perspective of achieving even 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, and more preferably 0.12 μm or more.

[0139] In the present invention, surface roughness Ra (arithmetic mean roughness Ra) refers to a value expressed in μm using the following formula: a portion having a measurement length L extracted along the center line of a roughness curve measured with a stylus meter, with the center line of the extracted portion as the X-axis and the axis orthogonal thereto as the Y-axis, when the roughness curve is expressed as Y = f(X). (Determination of L and measurement of the mean roughness are in accordance with JIS B 0601.)

[0140] [Formula 1]

[0141]

[0142] As a preferred embodiment of the lithographic printing plate precursor of the present invention (the first embodiment and the second embodiment), from the viewpoint of further improving the effect of the present invention, the area ratio of the specific convex portion is 10% or less, and the density of the second specific concave portion is 6000 pieces / mm 2 or above, and a lithographic printing plate precursor having the surface area ratio ΔS of 45% or more.

[0143] As another preferred embodiment of the lithographic printing plate precursor of the present invention (the first embodiment and the second embodiment), from the viewpoint of achieving a more excellent effect of the present invention, a lithographic printing plate precursor in which the area ratio of the specific convex portion is less than 10% and the above-mentioned surface area ratio ΔS is greater than 20% can be cited.

[0144] As another preferred embodiment of the lithographic printing plate precursor of the present invention (the first embodiment and the second embodiment), from the viewpoint of achieving a more excellent effect of the present invention, a lithographic printing plate precursor in which the area ratio of the specific convex portion is less than 10% and the above-mentioned surface area ratio ΔS is greater than 45% can be cited.

[0145] As another preferred embodiment of the lithographic printing plate precursor of the present invention (the first embodiment and the second embodiment), from the viewpoint of achieving a more excellent effect of the present invention, a lithographic printing plate precursor in which the area ratio of the specific convex portion is less than 7% and the above-mentioned surface area ratio ΔS is greater than 20% can be cited.

[0146] As another preferred embodiment of the lithographic printing plate precursor of the present invention (the first embodiment and the second embodiment), from the viewpoint of achieving a more excellent effect of the present invention, a lithographic printing plate precursor in which the area ratio of the specific convex portion is less than 7% and the above-mentioned surface area ratio ΔS is greater than 45% can be cited.

[0147] Furthermore, in the present invention, from the viewpoint of improving visibility, the surface of the image recording layer side of the aluminum support, that is, the surface of the anodic oxide film, L * a * b * Lightness L in the color system * The value of is preferably 68-90, more preferably 75-90.

[0148] Moreover, L * a * b * a in the color system * The value of is preferably -4 to 4, b * The value of is preferably -4 to 4.

[0149] Here, L * a * b * L in color system * 、a * and b * The average value of five measurements using a colorimeter (for example, CR-221, manufactured by Konica Minolta, Inc.) is employed.

[0150] Figure 1 This is a schematic cross-sectional view of one embodiment of the lithographic printing plate precursor of the present invention.

[0151] Figure 1 The lithographic printing plate precursor 10 shown has an aluminum support 12a and an image recording layer 16 disposed on the aluminum support 12a. Figure 1 As shown, it is preferable to further include an undercoat layer 14 between the aluminum support 12 a and the image recording layer 16 .

[0152] Figure 2 This 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 anodic aluminum oxide film 20a (hereinafter referred to simply as "anodic oxide film 20a") are laminated in this order. The anodic oxide film 20a in the aluminum support 12a is located on the image-recording layer 16 side. Specifically, the lithographic printing plate precursor 10 comprises the aluminum plate 18, the anodic oxide film 20a, the undercoat layer 14, and the image-recording layer 16 in this order.

[0153] And, as Figure 2As shown, the anodic oxide film 20a preferably has micropores 22a extending from its surface toward the aluminum plate 18. The term "micropore" is a general term for pores in the anodic oxide film and does not define the size of the pores.

[0154] As will be described in detail later, the primer layer 14 is not an essential structure but is a layer disposed as needed.

[0155] Hereinafter, each structure of the planographic printing plate precursor 10 will be described in detail.

[0156] [Aluminum Plate]

[0157] The aluminum plate 18 (aluminum support) is a dimensionally stable metal primarily composed of aluminum and includes aluminum or an aluminum alloy. Examples of the aluminum plate 18 include a pure aluminum plate, an alloy plate primarily composed of aluminum and containing trace amounts of foreign elements, or a plastic film or paper laminated or vapor-deposited with aluminum (alloy).

[0158] The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of the foreign elements in the alloy is 10% by mass or less. A pure aluminum plate is preferred as the aluminum plate 18. However, completely pure aluminum is difficult to produce due to smelting technology, so a small amount of foreign elements may be contained.

[0159] The composition of the aluminum plate 18 is not limited, and publicly known materials (for example, JIS A1050, JIS A1100, JIS A3103, and JIS A3005) can be appropriately used.

[0160] 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. The width and thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the needs of the user.

[0161] [Anodic oxide film]

[0162] The anodic oxide film 20a is a film generally formed on the surface of the aluminum plate 18 by anodizing, and preferably has ultrafine micropores 22a that are substantially perpendicular to the film surface and uniformly distributed. The micropores 22a extend from the surface of the anodic oxide film 20a on the image recording layer 16 side (the surface of the anodic oxide film 20a on the side opposite to the aluminum plate 18 side) in the thickness direction (on the aluminum plate 18 side).

[0163] The average diameter (average opening diameter) of the micropores 22a at the surface of the anodic oxide film 20a is preferably 10 to 150 nm, more preferably 10 to 100 nm. From the perspective of a balance between stain resistance and image visibility, 15 to 100 nm is further preferred, 15 to 60 nm is particularly preferred, 20 to 50 nm is particularly preferred, and 25 to 40 nm is most preferred. The same effect can be achieved whether the internal diameter of the pores is wider or narrower than the surface layer.

[0164] The average diameter of the micropores 22a is the value obtained by observing the surface of the anodic oxide film 20a using a field emission scanning electron microscope (FE-SEM) with a magnification of 150,000 times with N=4 images, and measuring the presence of micropores in the 400×600nm range in the obtained 4 images. 2 The diameter of the micropores within the range of and the average value are obtained.

[0165] When the shape of the micropore 22a is not circular, the equivalent circle diameter is used. The “equivalent circle diameter” refers to the diameter of a circle assuming the shape of the opening to have the same projected area as the opening.

[0166] 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.

[0167] The depth is obtained by taking a photograph of the cross section of the anodic oxide film 20 a (magnification 150,000), measuring the depths of 25 or more micropores 22 a , and averaging the measured depths.

[0168] The shape of the micropores 22a is not particularly limited. Figure 2 The micropore 22a is generally straight (generally cylindrical), but may also be conical with a diameter decreasing in the depth direction (thickness direction). Furthermore, the shape of the bottom of the micropore 22a is not particularly limited and may be a curved surface (convex) or a flat surface.

[0169] [Base coating]

[0170] The undercoat layer 14 is a layer disposed between the aluminum support 12a and the image recording layer 16 to improve the adhesion between the two. As described above, the undercoat layer 14 is a layer provided as needed and may not be included in the lithographic printing plate precursor.

[0171] The structure of the undercoat layer is not particularly limited, but it preferably contains polyvinylphosphonic acid from the viewpoint of suppressing ink adhesion in non-image areas while maintaining printing durability.

[0172] Here, as the polyvinylphosphonic acid, those disclosed in US Pat. No. 3,276,868, US Pat. No. 4,153,461, and US Pat. No. 4,689,272 can be used.

[0173] The structure of the undercoat layer is not particularly limited, but it preferably contains a compound having a betaine structure from the viewpoint of good stain resistance and deinking ability during paused printing.

[0174] Here, a betaine structure refers to a structure having at least one cation and at least one anion. Generally, the number of cations and anions is equal, resulting in overall neutrality. However, in the present invention, even when the number of cations and anions is unequal, a structure having a necessary amount of counterions to eliminate charge is considered a betaine structure.

[0175] The betaine structure is preferably any one of the structures represented by the following formula (1), formula (2), and formula (3).

[0176] [Chemical Formula 1]

[0177]

[0178] In the formula, A represents a structure with an anion, B + Indicates a structure with cations, L 0 Indicates a linking group. * Indicates a linking site (linking position).

[0179] A preferably represents a structure having an anion such as carboxylate, sulfonate, phosphonate, or phosphinate, and B + It preferably represents a structure having a cation such as ammonium, phosphonium, iodine, or sulfonium.

[0180] L 0 In formula (1) and formula (3), L 0 Examples of the divalent linking group include -CO-, -O-, -NH-, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. 0 A trivalent linking group can be mentioned.

[0181] The linking group preferably has 30 or less carbon atoms, including the carbon atoms of a substituent that may be described later.

[0182] Specific examples of the linking group include alkylene groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms), and arylene groups such as phenylene and xylylene (preferably having 5 to 15 carbon atoms, more preferably 6 to 10 carbon atoms).

[0183] Furthermore, these linking groups may further have a substituent.

[0184] 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.

[0185] As the betaine structure, from the viewpoint of superiority in at least one of printing durability, stain resistance, deinking ability during paused printing, and image visibility, the structure represented by formula (i), formula (ii), or formula (iii) is preferred, and the structure represented by formula (i) is more preferred. * indicates a linking site.

[0186] [Chemical Formula 2]

[0187]

[0188] 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, and R 1 With R 2 They can be linked to each other to form a ring structure.

[0189] The ring structure may have a heteroatom such as an oxygen atom. The ring structure is preferably a 5- to 10-membered ring, more preferably a 5- or 6-membered ring.

[0190] R 1 and R 2 The number of carbon atoms in is preferably 1-30, more preferably 1-20.

[0191] As R 1 and R 2 From the viewpoint of further improving the effects of the present invention, a hydrogen atom, a methyl group, or an ethyl group is preferred.

[0192] L 1 It represents a divalent linking group, 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.

[0193] As L 1 , preferably a straight-chain alkylene group having 3 to 5 carbon atoms.

[0194] In formula (i), A represents a structure having an anion, preferably a carboxylate, a sulfonate, a phosphonate or a phosphinate.

[0195] Specifically, the following structures can be mentioned.

[0196] [Chemical Formula 3]

[0197]

[0198] In formula (i), preferably L 1 is a linear alkylene group with 4 or 5 carbon atoms and A is a sulfonate, more preferably L 1 A is a combination of a linear alkylene group having 4 carbon atoms and a sulfonate.

[0199] In formula (ii), L 2 It represents a divalent linking group, 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.

[0200] B + It represents a structure having a cation, preferably an ammonium, phosphonium, iodine or sulfonium structure. Among them, an ammonium or phosphonium structure is preferred, and an ammonium structure is more preferred.

[0201] Examples of the structure having a cation include a trimethylammonium group, a triethylammonium group, a tributylammonium group, a benzyldimethylammonium group, a diethylhexylammonium group, a (2-hydroxyethyl)dimethylammonium group, a pyridinium group, an N-methylimidazolyl group, an N-acridinium group, a trimethylphosphino group, a triethylphosphino group, and a triphenylphosphino group.

[0202] In formula (iii), L 3 It represents a divalent linking group, 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.

[0203] A - represents a structure having an anion, preferably a carboxylate, sulfonate, phosphonate or phosphinate, the details and preferred examples of which are the same as those of A in formula (i). - same.

[0204] R 3 ~R 7 Each independently represents a hydrogen atom or a substituent (preferably having 1 to 30 carbon atoms), R 3 ~R 7 At least one of them represents a connecting portion.

[0205] R as the connecting part 3 ~R 7 At least one of them can be used as R 3 ~R 7 At least one substituent in the compound may be linked to another site in the compound, and may be directly linked to another site in the compound via a single bond.

[0206] As R3 ~R 7 The substituent represented by includes 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 group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group (including an anilino group), an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfamoylamino group, an alkyl and arylsulfonylamino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfamoyl group, a sulfo group, an alkyl and arylsulfinyl group, an alkyl and arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an aryl and heterocyclic azo group, an imide group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, and a silyl group.

[0207] From the viewpoint of achieving more excellent effects of the present invention, the compound is preferably a polymer (hereinafter also referred to as a "specific polymer") comprising a repeating unit having a betaine structure. The repeating unit having a betaine structure is preferably a repeating unit represented by formula (A1).

[0208] [Chemical Formula 4]

[0209]

[0210] Where 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.

[0211] Examples of the divalent linking group include -CO-, -O-, -NH-, a divalent aliphatic group, a divalent aromatic group, and a combination thereof.

[0212] Specific examples of L including the above-mentioned combination are given below. In the following examples, the left side is bonded to the main chain, and the right side is bonded to X.

[0213] L1: -CO-O-divalent aliphatic group-

[0214] L2: -CO-O-divalent aromatic group-

[0215] L3: -CO-NH-divalent aliphatic group-

[0216] L4: -CO-NH- divalent aromatic group -

[0217] L5: -CO-divalent aliphatic group-

[0218] L6: -CO- divalent aromatic group -

[0219] L7: -CO-divalent aliphatic group-CO-O-divalent aliphatic group-

[0220] L8: -CO-divalent aliphatic group-O-CO-divalent aliphatic group-

[0221] L9: -CO-divalent aromatic group-CO-O-divalent aliphatic group-

[0222] L10: -CO-divalent aromatic group-O-CO-divalent aliphatic group-

[0223] L11: -CO-divalent aliphatic group-CO-O-divalent aromatic group-

[0224] L12: -CO-divalent aliphatic group-O-CO-divalent aromatic group-

[0225] L13: -CO-divalent aromatic group-CO-O-divalent aromatic group-

[0226] L14: -CO-divalent aromatic group-O-CO-divalent aromatic group-

[0227] L15: -CO-O-divalent aromatic group-O-CO-NH-divalent aliphatic group-

[0228] L16: -CO-O-divalent aliphatic group-O-CO-NH-divalent aliphatic group-

[0229] Examples of the divalent aliphatic group include an alkylene group, an alkenylene group, and an alkynylene group.

[0230] Examples of the divalent aromatic group include an aryl group, and a phenylene group or a naphthylene group is preferred.

[0231] X represents a betaine structure. X is preferably a structure represented by the above-mentioned formula (i), formula (ii) or formula (iii).

[0232] Particularly, in formula (A1), a combination in which L is L1 or L3, X is a structure represented by formula (i), and A in formula (i) is a sulfonate group is preferred.

[0233] The content of the repeating unit having a betaine structure in the specific polymer is not particularly limited, but is generally 20 to 95% by mass. From the viewpoint of achieving even better effects of the present invention, it is preferably 50 to 95% by mass, and more preferably 60 to 90% by mass, relative to all the repeating units constituting the specific polymer.

[0234] The specific polymer may contain other repeating units in addition to the repeating unit having the above-mentioned betaine structure.

[0235] The specific polymer may include a repeating unit having a structure that interacts with the surface of the aluminum support 12 a (hereinafter, also simply referred to as “interacting structure”).

[0236] Examples of the interacting structure include carboxylic acid structures, carboxylate structures, sulfonic acid structures, sulfonate structures, phosphonic acid structures, phosphonate structures, phosphate structures, phosphate ester structures, β-diketone structures, and phenolic hydroxyl groups. Examples include structures represented by the following formulas. Among these, carboxylic acid structures, carboxylate structures, sulfonic acid structures, sulfonate structures, phosphonic acid structures, phosphonate structures, phosphate ester structures, and phosphate ester structures are preferred.

[0237] [Chemical Formula 5]

[0238]

[0239] 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, 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, and B represents a boron atom.

[0240] The repeating unit having an interactive structure is preferably a repeating unit represented by formula (A2).

[0241] [Chemical Formula 6]

[0242]

[0243] Where R 201 ~R 203 Each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 6 carbon atoms) or a halogen atom.

[0244] 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, and a combination thereof.

[0245] Specific examples of L including combinations include the same examples as those in the above formula (A1) and the following L17 and L18.

[0246] L17: -CO-NH-

[0247] L18: -CO-O-

[0248] Among L1 to L18, L1 to L4, L17 or L18 is preferred.

[0249] Q represents an interactive structure, and its preferred structure is the same as described above.

[0250] The content of the repeating unit having an interactive structure in the specific polymer is not particularly limited, but is preferably 1 to 40% by mass, more preferably 3 to 30% by mass, based on all repeating units constituting the specific polymer, from the viewpoint of achieving better effects of the present invention.

[0251] The specific polymer may include a repeating unit having a radically polymerizable reactive group.

[0252] Examples of the radical polymerizable reactive group include unsaturated bond groups capable of addition polymerization (e.g., (meth)acryloyl, (meth)acrylamide, (meth)acrylonitrile, allyl, vinyl, vinyloxy, and alkynyl groups) and functional groups capable of chain transfer (e.g., mercapto groups).

[0253] The specific polymer containing repeating units having radically polymerizable reactive groups can be obtained by introducing radically polymerizable reactive groups using the method described in Japanese Patent Application Laid-Open No. 2001-312068. By using a specific polymer containing repeating units having radically polymerizable reactive groups, excellent developability is exhibited in the unexposed areas, while polymerization in the exposed areas suppresses the permeability of the developer solution, further improving the bonding and adhesion between the aluminum support 12a and the image recording layer 16.

[0254] The content of the repeating unit having a radically polymerizable reactive group in the specific polymer is not particularly limited, but is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, based on all repeating units constituting the specific polymer, from the viewpoint of achieving better effects of the present invention.

[0255] The content of the compound having the betaine structure in the primer layer 14 is not particularly limited, but is preferably 80% by mass or more, more preferably 90% by mass or more, relative to the total mass of the primer layer. The upper limit is 100% by mass.

[0256] Furthermore, although the primer layer 14 including the compound having a betaine structure has been described above, the primer layer may also include other compounds.

[0257] For example, the primer layer may be in a form containing a compound having a hydrophilic group. Examples of the hydrophilic group include a carboxylic acid group and a sulfonic acid group.

[0258] The compound having a hydrophilic group may further have a radical polymerizable reactive group.

[0259] [Image recording layer]

[0260] The image recording layer 16 is preferably an image recording layer that can be removed by printing ink and / or fountain solution.

[0261] Hereinafter, each constituent component of the image recording layer 16 will be described.

[0262] <Infrared absorber>

[0263] The image recording layer 16 preferably contains an infrared absorber.

[0264] The infrared absorber preferably has a maximum absorption in the wavelength range of 750 to 1400 nm. In particular, in on-press development-type lithographic printing plate precursors, on-press development is sometimes performed in a printing press under white light. Therefore, by using an infrared absorber having a maximum absorption in the wavelength range of 750 to 1400 nm, which is less susceptible to the effects of white light, a lithographic printing plate precursor with excellent developability can be obtained.

[0265] As the infrared absorber, a dye or a pigment is preferable.

[0266] Examples of the dye include commercially available dyes and known dyes described in documents such as "Dye Handbook" (edited by The Society of Synthetic Organic Chemistry, Japan, published in 1970).

[0267] Specific examples of the dye include cyanine dyes, squarylium dyes, pyrylium salts, nickel thiol complexes, and indocyanine dyes. Among them, cyanine dyes and indocyanine dyes are preferred, cyanine dyes are more preferred, and cyanine dyes represented by the following formula (a) are even more preferred.

[0268] Formula (a)

[0269] [Chemical Formula 7]

[0270]

[0271] In formula (a), X 1 represents a hydrogen atom, a halogen atom, -N(R 9 )(R 10 ),-X 2 -L 1 or the groups shown below.

[0272] [Chemical Formula 8]

[0273]

[0274] R 9 and R 10 Each independently represents an aromatic hydrocarbon group, an alkyl group or a hydrogen atom, R 9 With R 10 They may be bonded to each other to form a ring. Among them, phenyl is preferred.

[0275] X2 represents an oxygen atom or a sulfur atom, L 1 It represents a hydrocarbon group having 1 to 12 carbon atoms which may contain a heteroatom (N, S, O, a halogen atom, Se).

[0276] About X a - , to be compared with Z a - Defined in the same way, R a represents a hydrogen atom, an alkyl group, an aryl group, an amino group or a halogen atom.

[0277] R 1 and R 2 Each independently represents a hydrocarbon group having 1 to 12 carbon atoms. 1 With R 2 They may be bonded to each other to form a ring, and when forming a ring, they preferably form a 5-membered ring or a 6-membered ring.

[0278] Ar 1 and Ar 2 Each independently represents an aromatic hydrocarbon group which may have a substituent (for example, an alkyl group). As the aromatic hydrocarbon group, a benzene ring group or a naphthyl ring group is preferred.

[0279] Y 1 and Y 2 Each independently represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms.

[0280] 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).

[0281] 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.

[0282] And, Za - The cyanine pigment represented by formula (a) has an anionic substituent in its structure. If charge neutralization is not required, Za is not required. - As Za - Examples of the ion include halide ion, perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion and sulfonate ion, and preferably perchlorate ion, hexafluorophosphate ion or arylsulfonate ion.

[0283] The above-mentioned infrared absorbing dye may be used alone or in combination of two or more. In addition to infrared absorbing dyes such as pigments, infrared absorbers other than the infrared absorbing dyes may also be used in combination. As pigments, compounds described in paragraphs

[0072] to

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

[0284] The content of the infrared absorber is preferably 0.05 to 30% by mass, more preferably 0.1 to 20% by mass, relative to the total mass of the image recording layer 16 .

[0285] <Polymerization Initiator>

[0286] The image-recording layer 16 preferably contains a polymerization initiator.

[0287] The polymerization initiator is preferably a compound that generates free radicals by light, heat, or both of these energies and initiates polymerization of a compound having a polymerizable unsaturated group (so-called free radical polymerization initiator). Examples of the polymerization initiator include photopolymerization initiators and thermal polymerization initiators.

[0288] Specifically, the polymerization initiators described in paragraphs

[0115] to

[0141] of JP-A-2009-255434 can be used as the polymerization initiator.

[0289] In addition, as the polymerization initiator, from the viewpoint of reactivity and stability, an oxime ester compound or an onium salt such as a diazonium salt, an iodonium salt, or a sulfonium salt is preferred.

[0290] The content of the polymerization initiator is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, relative to the total mass of the image recording layer 16 .

[0291] <Polymerizable Compound>

[0292] The image recording layer 16 preferably contains a polymerizable compound.

[0293] As the polymerizable compound, an addition-polymerizable compound having at least one ethylenically unsaturated bond is preferred. Among them, a compound having at least one (preferably two) terminal ethylenically unsaturated bonds is more preferred. So-called free-radical polymerizable compounds are more preferred.

[0294] As the polymerizable compound, for example, the polymerizable compounds exemplified in paragraphs

[0142] to

[0163] of JP-A-2009-255434 can be used.

[0295] Furthermore, preferred are carbamate-based addition polymerizable compounds produced by the addition reaction of isocyanates and hydroxyl groups. Specific examples thereof include vinyl carbamate compounds containing two or more polymerizable vinyl groups in one molecule, which are obtained by adding a polyisocyanate compound having two or more isocyanate groups in one molecule to a vinyl monomer containing a hydroxyl group represented by the following formula (A), as described in Japanese Patent Publication No. 48-041708.

[0296] CH2=C(R 4 )COOCH2CH(R 5 )OH (A)

[0297] (Among them, R 4 and R 5 represents H or CH3.)

[0298] The content of the polymerizable compound is preferably 3 to 80% by mass, more preferably 10 to 75% by mass, relative to the total mass of the image recording layer 16 .

[0299] <Binder Polymer>

[0300] The image-recording layer 16 preferably contains a binder polymer.

[0301] Examples of the binder polymer include known binder polymers. Specifically, examples of the binder polymer include acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, methacrylic resins, polystyrene resins, novolac-type phenolic resins, polyester resins, synthetic rubbers, and natural rubbers.

[0302] To enhance the film strength of the image area, the binder polymer may be crosslinkable. To achieve crosslinkability, 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 be introduced through copolymerization.

[0303] As the binder polymer, for example, the binder polymers disclosed in paragraphs

[0165] to

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

[0304] The content of the binder polymer is preferably 5 to 90% by mass, more preferably 5 to 70% by mass, relative to the total mass of the image recording layer 16 .

[0305] <Surfactant>

[0306] The image recording layer 16 may contain a surfactant in order to promote on-press development at the start of printing and to improve the coating surface condition.

[0307] Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorine-based surfactants.

[0308] As the surfactant, for example, the surfactants disclosed in paragraphs

[0175] to

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

[0309] The content of the surfactant is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, relative to the total mass of the image recording layer 16 .

[0310] <Developer>

[0311] The image-recording layer 16 preferably contains a developer, and more preferably contains an acid developer.

[0312] As used herein, a "developer" refers to a compound having the property of developing or fading color upon stimulation by light, acid, or the like, thereby changing the color of the image-recording layer. Furthermore, an "acid developer" refers to a compound having the property of developing or fading color upon heating while receiving protons from an electron-accepting compound (e.g., an acid). Acid developers are particularly preferably colorless compounds having a partial skeleton such as a lactone, lactam, sultone, spiropyran, ester, or amide, and these partial skeletons undergo rapid ring-opening or cleavage upon contact with an electron-accepting compound.

[0313] Examples of such acid developers 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-tolyl)-6-dimethylaminophthalide, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)phthalide, and 3-(4-dimethylaminophenyl)-3-(2-methylindol-3-yl)phthalide. 3-Indole-3-yl)phthalide, 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,

[0314] 3,3-bis[1,1-bis(4-dimethylaminophenyl)ethen-2-yl]-4,5,6,7-tetrachlorophthalide, 3,3-bis[1,1-bis(4-pyrrolidinonephenyl)ethen-2-yl]-4,5,6,7-tetrabromophthalide, 3,3-bis[1-(4-dimethylaminophenyl)-1-(4-methoxyphenyl)ethen-2-yl]-4,5,6,7-tetrachlorophthalide, 3,3-bis[1-(4-pyrrolidinonephenyl)-1-(4-methoxyphenyl)ethen-2-yl]-4,5,6,7-tetrachlorophthalide, 3-[1,1-bis(1-ethyl Phthalide such as phthalide, 3-[1,1-bis(1-ethyl-2-methylindol-3-yl)ethen-2-yl]-3-(4-diethylaminophenyl)phthalide, 3-[1,1-bis(1-ethyl-2-methylindol-3-yl)ethen-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, 3-(2-methyl-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindol-3-yl)phthalide,

[0315] 4,4-bis-dimethylaminobenzoylpropanol benzyl ether, N-halophenyl-leuco-auramine, N-2,4,5-trichlorophenyl leuco-auramine, rhodamine-B-anilino lactam, rhodamine-(4-nitroanilino) lactam, rhodamine-B-(4-chloroanilino) lactam, 3,7-bis(diethylamino)-10-benzoylphenazine, benzoyl leuco-methylene blue, 4-nitrobenzoylmethylene blue,

[0316] 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-N-n-butylamino-7-methylfluoran, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-octylaminofluoran, 3-diethylamino-7-di-n-hexylaminofluoran, 3-diethylamino-7-anilinefluoran, 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,

[0317] 3-N-n-hexyl-N-ethylamino-7-(2'-chlorophenylamino)fluoran, 3-diethylamino-6-chloro-7-anilinefluoran, 3-di-n-butylamino-6-chloro-7-anilinefluoran, 3-diethylamino-6-methoxy-7-anilinefluoran, 3-di-n-butylamino-6-ethoxy-7-anilinefluoran, 3-pyrrolidin-6-methyl-7-anilinefluoran, 3-hydropyridyl-6-methyl-7-anilinefluoran, 3-morpholino- 6-Methyl-7-aniline fluoran, 3-dimethylamino-6-methyl-7-aniline fluoran, 3-diethylamino-6-methyl-7-aniline fluoran, 3-di-n-butylamino-6-methyl-7-aniline fluoran, 3-di-n-pentylamino-6-methyl-7-aniline fluoran, 3-N-ethyl-N-methylamino-6-methyl-7-aniline fluoran, 3-N-n-propyl-N-methylamino-6-methyl-7-aniline fluoran, 3-N-n-propyl-N- Ethylamino-6-methyl-7-aniline fluoran, 3-N-n-butyl-N-methylamino-6-methyl-7-aniline fluoran, 3-N-n-butyl-N-ethylamino-6-methyl-7-aniline fluoran, 3-N-isobutyl-N-methylamino-6-methyl-7-aniline fluoran, 3-N-isobutyl-N-ethylamino-6-methyl-7-aniline fluoran, 3-N-isopentyl-N-ethylamino-6-methyl-7-aniline fluoran, 3-N-n-hexyl 3-N-cyclohexyl-N-ethylamino-6-methyl-7-aniline fluoran, 3-N-cyclohexyl-N-propylamino-6-methyl-7-aniline fluoran, 3-N-cyclohexyl-N-n-butyl-6-methyl-7-aniline fluoran, 3-N-cyclohexyl-N-n-hexylamino-6-methyl-7-aniline fluoran, 3-N-cyclohexyl-N-n-octylamino-6-methyl-7-aniline fluoran,

[0318] 3-N-(2'-methoxyethyl)-N-methylamino-6-methyl-7-aniline fluoran, 3-N-(2'-methoxyethyl)-N-ethylamino-6-methyl-7-aniline fluoran, 3-N-(2'-methoxyethyl)-N-isobutylamino-6-methyl-7-aniline fluoran, 3-N-(2'-ethoxyethyl)-N-methylamino-6-methyl-7-aniline fluoran, 3-N-(2'-ethoxyethyl)-N-ethylamino 3-N-(3'-methoxypropyl)-N-methylamino-6-methyl-7-aniline fluoran, 3-N-(3'-methoxypropyl)-N-ethylamino-6-methyl-7-aniline fluoran, 3-N-(3'-ethoxypropyl)-N-methylamino-6-methyl-7-aniline fluoran, 3-N-(3'-ethoxypropyl)-N-methylamino-6-methyl-7-aniline fluoran, 3-N-(3'-ethoxypropyl)-N-ethylamino-6-methyl-7-aniline fluoran, 2'-tetrahydrofurfuryl)-N-ethylamino-6-methyl-7-aniline fluoran, 3-N-(4'-tolyl)-N-ethylamino-6-methyl-7-aniline fluoran, 3-diethylamino-6-ethyl-7-aniline fluoran, 3-diethylamino-6-methyl-7-(3'-toluinyl)fluoran, 3-diethylamino-6-methyl-7-(2',6'-dimethylamino)fluoran, 3-di-n-butylamino-6-methyl-7 Fluoranes such as -(2',6'-dimethylamino)fluoran, 3-di-n-butylamino-7-(2',6'-dimethylamino)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, 3-[4'-(dimethylaminophenyl)]amino-5,7-dimethylfluoran,

[0319] 3-(2-methyl-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-n-propyloxycarbonylamino-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-methylamino-4-di-n-propylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, -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-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)- Phthalide such as indol-3-yl)-4- or 7-azaphthalide, 3-methyl-spiro-binaphthopyran, 3-ethyl-spiro-binaphthopyran, 3-phenyl-spiro-binaphthopyran, 3-benzyl-spiro-binaphthopyran, 3-methyl-naphtho-(3-methoxybenzo)spiropyran, 3-propyl-spiro-dibenzopyran-3,6-bis(dimethylamino)fluorene-9-spiro-3'-(6'-dimethylamino)phthalide, 3,6-bis(diethylamino)fluorene-9-spiro-3'-(6'-dimethylamino)phthalide,

[0320] In addition, 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, etc.

[0321] Among them, from the viewpoint of color development, the color developer used in the present invention is preferably at least one compound selected from the group consisting of spiropyran compounds, spirooxazine compounds, spirolactone compounds, and spirolactam compounds.

[0322] From the viewpoint of visibility, the hue of the pigment after color development is preferably green, blue, or black.

[0323] Furthermore, from the viewpoint of color development and visibility of the exposed portion, the acid developer is preferably a leuco dye.

[0324] The leuco pigment 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.

[0325] Furthermore, the leuco dye is preferably a leuco dye having a phthalide structure or a fluoran structure from the viewpoint of color development and visibility of the exposed portion.

[0326] Moreover, from the viewpoint of color development and visual recognition of the exposed portion, the above-mentioned leuco dye having a phthalide structure or a 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).

[0327] [Chemical Formula 9]

[0328]

[0329] In formula (Le-1) to formula (Le-3), ERG each independently represents an electron-donating group, X1 to X4 each independently represents a hydrogen atom, a halogen atom or a dialkylaniline group, and X5 to X 10 Each independently represents 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 does not exist, when Y2 is N, X4 does not exist, 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.

[0330] As the electron-donating group in the ERG of formula (Le-1) to formula (Le-3), from the viewpoint of color development and visual recognition of the exposed portion, 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, further preferably a monoalkylmonoarylamino group, a diarylamino group, a diheteroarylamino group or a monoarylmonoheteroarylamino group, and particularly preferably a monoalkylmonoarylamino group.

[0331] Furthermore, as the electron-donating group in the above-mentioned ERG, from the viewpoint of color development and visual recognition of the exposed portion, it is preferably a disubstituted 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 disubstituted amino group having a phenyl group having a substituent at at least one ortho position and an electron-donating group at the para position, further 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 or 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.

[0332] In the present invention, the ortho position in an aryl group or heteroaryl group other than a phenyl group refers to a bonding position adjacent to the 1st position (e.g., the 2nd position) when the bonding position of the aryl group or heteroaryl group to another structure is the 1st position.

[0333] Moreover, as the electron-donating group possessed by the above-mentioned aryl group or heteroaryl group, from the viewpoint of color development and visual recognition of the exposed portion, 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 still more preferably an alkoxy group.

[0334] From the viewpoint of color development and visibility of the exposed portion, X1 to X4 in Formulae (Le-1) to (Le-3) are each independently preferably a hydrogen atom or a chlorine atom, and more preferably a hydrogen atom.

[0335] From the viewpoint of color development and visibility of the exposed portion, X5 to X6 in formula (Le-2) or formula (Le-3) are 10Each independently preferably is 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 hydroxyl 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 is a hydrogen atom, a halogen atom, an alkyl group, an aryl, an alkoxy group or an aryloxy group; further preferably is a hydrogen atom, a halogen atom, an alkyl group or an aryl group; and particularly preferably is a hydrogen atom.

[0336] From the viewpoint of color development and visibility of the exposed portion, at least one of Y1 and Y2 in Formulas (Le-1) to (Le-3) is preferably C, and both Y1 and Y2 are more preferably C.

[0337] From the viewpoint of color development and visibility of the exposed portion, Ra1 in Formula (Le-1) to Formula (Le-3) is preferably an alkyl group or an alkoxy group, more preferably an alkoxy group, and still more preferably a methoxy group.

[0338] From the viewpoint of color development and visibility of the exposed portion, Rb1 to Rb4 in Formulas (Le-1) to (Le-3) are each independently preferably a hydrogen atom or an alkyl group, more preferably an alkyl group, and still more preferably a methyl group.

[0339] Furthermore, from the perspective of color development and visual recognition of the exposed portion, the above-mentioned leuco pigment having a phthalide structure or a fluoran structure is more preferably a compound represented by any one of the following formulas (Le-4) to (Le-6), and further preferably a compound represented by the following formula (Le-5).

[0340] [Chemical Formula 10]

[0341]

[0342] In formulas (Le-4) to (Le-6), ERG independently represents an electron-donating group, X1 to X4 independently represent a hydrogen atom, a halogen atom or a dialkylaniline group, Y1 and Y2 independently represent C or N, when Y1 is N, X1 does not exist, and when Y2 is N, X4 does not exist, Ra1 represents a hydrogen atom, an alkyl group or an alkoxy group, and Rb1 to Rb4 independently represent a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group.

[0343] ERG, X1~X4, Y1, Y2, Ra1 and Rb1~Rb4 in formula (Le-4) to formula (Le-6) have the same meanings as ERG, X1~X4, Y1, Y2, Ra1 and Rb1~Rb4 in formula (Le-1) to formula (Le-3), and the preferred embodiments are also the same.

[0344] Moreover, from the perspective of color development and visual recognition of the exposed part, the above-mentioned leuco pigment having a phthalide structure or a fluoran structure is further preferably a compound represented by any one of the following formulas (Le-7) to (Le-9), and is particularly preferably a compound represented by the following formula (Le-8).

[0345] [Chemical Formula 11]

[0346]

[0347] In formulas (Le-7) to (Le-9), X1 to X4 each independently represent a hydrogen atom, a halogen atom or a dialkylaniline group, Y1 and Y2 each independently represent C or N, when Y1 is N, X1 does not exist, and when Y2 is N, X4 does not exist, 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.

[0348] X1 to X4, Y1 and Y2 in formulas (Le-7) to (Le-9) have the same meanings as X1 to X4, Y1 and Y2 in formulas (Le-1) to (Le-3), and preferred embodiments are also the same.

[0349] From the viewpoint of color development and visibility of the exposed portion, 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 still more preferably a methoxy group.

[0350] From the viewpoint of color development and visibility of the exposed portion, Rb1 to Rb4 in Formulas (Le-7) to (Le-9) are each independently preferably a hydrogen atom, an alkyl group, or an aryl group substituted with an alkoxy group, more preferably an alkyl group, and still more preferably a methyl group.

[0351] From the viewpoint of color development and visibility of the exposed portion, Rc1 and Rc2 in formula (Le-8) are each independently preferably a phenyl group or an alkylphenyl group, and more preferably a phenyl group.

[0352] Furthermore, from the viewpoint of color development and visual recognition of the exposed portion, 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, further 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.

[0353] Furthermore, in formula (Le-8), from the viewpoint of color development and visibility of the exposed portion, it is preferred that X1 to X4 are hydrogen atoms, and Y1 and Y2 are C.

[0354] Furthermore, in formula (Le-8), from the viewpoint of color development and visibility of the exposed portion, Rb1 and Rb2 are each independently preferably an aryl group substituted with an alkyl group or an alkoxy group.

[0355] Moreover, in formula (Le-8), from the perspective of color development and visual recognition of the exposed portion, Rb1 and Rb2 are each independently preferably an aryl group or a heteroaryl group, more preferably an aryl group, further preferably an aryl group having an electron-donating group, and especially preferably a phenyl group having an electron-donating group at the para position.

[0356] Furthermore, as the above-mentioned electron-donating group in Rb1, Rb2, Rc1 and Rc2, from the viewpoint of color development and visual recognition of the exposed portion, preferably it is 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 still more preferably an alkoxy group.

[0357] Furthermore, as the acid developer, it is preferred that a compound represented by the following formula (Le-10) be contained from the viewpoint of color development and visibility of the exposed portion.

[0358] [Chemical Formula 12]

[0359]

[0360] In formula (Le-10), Ar1 each independently represents an aryl group or a heteroaryl group, and Ar2 each 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.

[0361] Ar1 in formula (Le-10) has the same meaning as Rb1 and Rb2 in formulas (Le-7) to (Le-9), and preferred embodiments are also the same.

[0362] Ar2 in formula (Le-10) has the same meaning as Rc1 and Rc2 in formulas (Le-7) to (Le-9), and preferred embodiments are also the same.

[0363] The alkyl groups in formula (Le-1) to formula (Le-9) may be linear, branched, or have a ring structure.

[0364] Furthermore, the number of carbon atoms in the alkyl groups in formula (Le-1) to formula (Le-9) is preferably 1 to 20, more preferably 1 to 8, further preferably 1 to 4, and particularly preferably 1 or 2.

[0365] The number of carbon atoms in the aryl group in formula (Le-1) to formula (Le-10) is preferably 6 to 20, more preferably 6 to 10, and even more preferably 6 to 8.

[0366] Specific examples of the aryl group in formula (Le-1) to formula (Le-10) include phenyl, naphthyl, anthryl, and phenanthryl groups, which may have a substituent.

[0367] Specific examples of the heteroaryl group in formula (Le-1) to formula (Le-10) include optionally substituted furyl, pyridyl, pyrimidyl, pyrazolyl, and phenylthio groups.

[0368] Furthermore, each of the monovalent organic groups, alkyl groups, aryl groups, heteroaryl groups, dialkylanilino groups, alkylamino groups, and alkoxy groups in Formulas (Le-1) to (Le-10) may have 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, hydroxyl 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 these substituents.

[0369] Preferable examples of the leuco dye having a phthalide structure or a fluoran structure include the following compounds: Me represents a methyl group.

[0370] [Chemical Formula 13]

[0371]

[0372] [Chemical Formula 14]

[0373]

[0374] [Chemical Formula 15]

[0375]

[0376] [Chemical Formula 16]

[0377]

[0378] [Chemical Formula 17]

[0379]

[0380] [Chemical Formula 18]

[0381]

[0382] [Chemical Formula 19]

[0383]

[0384] As the color developer, commercially available products can be used, and examples thereof include 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, Vermilion-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, Red-8 (all manufactured by YAMAMOTO CHEMICALS INC.), crystal violet lactone (manufactured by Tokyo Chemical Industry Co., Ltd.), etc. Among these commercially available products, ETAC, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, H-3035, ATP, H-1046, H-2114, GREEN-DCF, Blue-63, GN-169, and crystal violet lactone are preferred because the films formed therefrom have good visible light absorbance.

[0385] These color developers may be used alone or in combination of two or more.

[0386] The content of the developer is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass, relative to the total mass of the image recording layer.

[0387] The image recording layer 16 may further contain other compounds in addition to the above-mentioned ones as needed.

[0388] Examples of other compounds include colorants, printout agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic fine particles, and low-molecular-weight hydrophilic compounds disclosed in paragraphs

[0181] to

[0190] of JP-A-2009-255434.

[0389] In addition, other compounds include hydrophobic precursors (microparticles capable of converting the image recording layer into hydrophobic properties when heat is applied) disclosed in paragraphs

[0191] to

[0217] of JP-A-2012-187907, low-molecular-weight hydrophilic compounds, sensitizers (e.g., phosphonium compounds, nitrogen-containing low-molecular-weight compounds, ammonium-containing polymers), and chain transfer agents.

[0390] [Other layers]

[0391] The lithographic printing plate precursor of the present invention may include other layers in addition to the aluminum support 12 a , undercoat layer 14 , and image-recording layer 16 described above.

[0392] For example, a protective layer may be included on the image recording layer 16 as needed to prevent scratches or the like from being generated in the image recording layer 16 , block oxygen, and prevent ablation during high-intensity laser exposure.

[0393] Examples of the material used for the protective layer include materials described in paragraphs

[0213] to

[0227] of JP-A-2009-255434 (water-soluble polymer compounds, inorganic layered compounds, etc.).

[0394] [Method for producing an aluminum support]

[0395] 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 being able to efficiently produce a predetermined aluminum support, it is preferred to include a hydrochloric acid electrolytic treatment step: for an aluminum plate, in a hydrochloric acid treatment solution which may contain sulfuric acid, the liquid 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 400C / dm 2 Below, and the peak current value of the AC current waveform is 80A / dm 2 AC electrolysis was carried out under the following conditions to produce a roughened aluminum plate.

[0396] In addition, when the hydrochloric acid treatment liquid contains sulfuric acid, the ratio of the content of sulfuric acid to the content of hydrochloric acid is preferably 0.1 or less.

[0397] Furthermore, the method for producing an aluminum support of the present invention preferably includes an anodizing step of forming an aluminum anodic oxide film on the aluminum plate by anodizing the roughened aluminum plate after the hydrochloric acid electrolysis step.

[0398] Furthermore, the method for producing an aluminum support body of the present invention preferably includes a pore expansion step of etching the aluminum plate having the anodic oxide film formed thereon after the anodic oxide step to expand the diameter of micropores in the anodic oxide film.

[0399] Hereinafter, each of the above steps and optional treatments will be described in detail.

[0400] <Mechanical roughening treatment>

[0401] The method for producing an aluminum support of the present invention may include performing a mechanical roughening treatment before the hydrochloric acid electrolytic treatment step.

[0402] As a mechanical roughening treatment method, for example, a wire brushing method in which a metal wire is used to scrape the aluminum surface, a ball milling method in which a grinding ball and an abrasive are used to frost the aluminum surface, and a brushing method in which a nylon brush and an abrasive are used to frost the surface as described in Japanese Patent Application Laid-Open No. 6-135175 and Japanese Patent Publication No. 50-040047 can be used.

[0403] <Hydrochloric Acid Electrolysis Process>

[0404] The hydrochloric acid electrolytic treatment step of the method for manufacturing an aluminum support of the present invention is preferably a hydrochloric acid electrolytic treatment step as follows: for an aluminum plate, in a hydrochloric acid treatment solution which may contain sulfuric acid, the liquid 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 400C / dm 2 Below, and the peak current value of the AC current waveform is 80A / dm 2 AC electrolysis was carried out under the following conditions to produce a roughened aluminum plate.

[0405] In the present invention, by performing such a hydrochloric acid electrolysis treatment and then performing an anodic oxidation treatment described later, the above-mentioned lithographic printing plate precursor (the first and second embodiments of the lithographic printing plate precursor) can be efficiently produced.

[0406] The hydrochloric acid treatment liquid contains hydrochloric acid, and the concentration of the hydrochloric acid is preferably 5 to 30 g / L, more preferably 10 to 20 g / L.

[0407] 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 greater than 0 g / L.

[0408] 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, more preferably 5.0 to 20.0 g / L.

[0409] When the hydrochloric acid treatment liquid contains sulfuric acid, the ratio of the content of sulfuric acid to the content of hydrochloric acid is preferably 0.1 or less. The lower limit is not particularly limited, but may be greater than 0.

[0410] The liquid temperature of the hydrochloric acid treatment liquid is 30° C. or lower, preferably 26° C. or lower, more preferably 23° C. or lower. The lower limit is not particularly limited, but is preferably 10° C. or higher, more preferably 15° C. or higher.

[0411] In the present invention, the total amount of electricity (the total amount of electricity participating in the anode reaction of the aluminum plate at the end of the hydrochloric acid electrolysis treatment) is preferably 400C / dm 2 Below, more preferably 350C / dm 2 The lower limit of the total amount of electricity is not particularly limited, but is preferably 50 C / dm 2 More than, more preferably 100C / dm 2 above.

[0412] The peak current value of the AC current waveform is preferably 80A / dm 2 Below, more preferably 70A / dm 2 The peak current value is preferably 10A / dm 2 More than, more preferably 20A / dm 2 above.

[0413] The AC current waveform used in the hydrochloric acid electrolysis treatment can be a sine wave, a rectangular wave, a trapezoidal wave, a triangular wave, etc. The frequency is preferably 0.1 to 250 Hz.

[0414] Figure 3 This is a graph showing an example of an alternating waveform current waveform used in hydrochloric acid electrolysis treatment.

[0415] exist Figure 3In the equation, ta is the anodic reaction time, tc is the cathodic reaction time, tp is the time until the current reaches the peak from 0, Ia is the current at the peak on the anodic circulation side, and Ic is the current at the peak on the cathode circulation side. In the trapezoidal wave, the time tp until the current reaches the peak from 0 is preferably 1 to 10 msec. The conditions for one cycle of alternating current used for hydrochloric acid electrolysis treatment are preferably: the ratio tc / ta of the anodic reaction time ta of the aluminum plate to the cathode reaction time tc is 1 to 20, the ratio Qc / Qa of the electric quantity Qc when the aluminum plate is the anode to the electric quantity Qa when the aluminum plate is the anode is 0.3 to 20, and the anodic reaction time ta is in the range of 5 to 1000 msec. Regarding the current density, the anode circulation side Ia and the cathode circulation side Ic of the current peak of the trapezoidal wave are preferably in the above range (80 A / dm 2 below).

[0416] Can be used in hydrochloric acid electrolysis using alternating current Figure 4 The device shown.

[0417] Figure 4 This is a side view showing an example of a radial type unit in hydrochloric acid electrolysis using alternating current.

[0418] exist Figure 4 In the figure, 50 is the main electrolytic cell, 51 is the AC power supply, 52 is the radial drum, 53a and 53b are the main electrodes, 54 is the electrolyte supply port, 55 is the electrolyte, 56 is the slit, 57 is the electrolyte channel, 58 is the auxiliary anode, 60 is the auxiliary anode tank, and W is the aluminum plate. When using two or more electrolytic cells, the electrolysis conditions can be the same or different.

[0419] The aluminum plate W is wound onto a radial drum roller 52 that is immersed in the main electrolytic tank 50 and is electrolytically treated during transportation through a main electrode 53a and a main electrode 53b connected to an AC power supply 51. An electrolyte 55 is supplied from an electrolyte supply port 54 through a slit 56 to an electrolyte channel 57 between the radial drum roller 52 and the main electrode 53a and the main electrode 53b. The aluminum plate W treated in the main electrolytic tank 50 is then electrolytically treated in an auxiliary anode tank 60. In the auxiliary anode tank 60, an auxiliary anode 58 is disposed opposite the aluminum plate W, and the electrolyte 55 is supplied in a manner that flows in the space between the auxiliary anode 58 and the aluminum plate W.

[0420] <Alkali Etching Treatment>

[0421] In the method for producing an aluminum support of the present invention, it is preferable to perform an alkali etching treatment after the mechanical roughening treatment or before or after the hydrochloric acid electrolytic treatment step.

[0422] In addition, regarding the alkaline etching treatment performed before the hydrochloric acid electrolysis treatment, if no mechanical roughening treatment is performed, it is performed for the purpose of removing rolling oil, pollution and natural oxide film on the surface of the aluminum substrate (rolled aluminum). If the mechanical roughening treatment has been performed, it is performed for the purpose of dissolving the edge portions of the unevenness generated by the mechanical roughening treatment and changing the steep unevenness into a surface with smooth corrugations.

[0423] When mechanical roughening treatment is not performed before alkali etching, the etching amount is preferably 0.1 to 10 g / m 2 , more preferably 1 to 5 g / m 2 If the etching amount is 1 to 10 g / m 2 , the rolling oil, pollution, natural oxide film, etc. on the surface can be fully removed.

[0424] When mechanical roughening treatment is performed before alkali etching treatment, the etching amount is preferably 3 to 20 g / m 2 , more preferably 5 to 15 g / m 2 .

[0425] The alkali etching treatment performed immediately after the hydrochloric acid electrolysis treatment is performed to dissolve the stains generated in the acidic electrolyte and to dissolve the edges of the unevenness formed by the hydrochloric acid electrolysis treatment. The unevenness formed by the hydrochloric acid electrolysis treatment varies depending on the type of electrolyte, so the optimal etching amount also varies. However, the etching amount of the alkali etching treatment performed after the hydrochloric acid electrolysis treatment is preferably 0 to 0.5 g / m 2 , more preferably 0 to 0.3 g / m 2 .

[0426] Examples of the alkali used in the alkaline solution include caustic soda and alkali metal salts, and an aqueous solution of caustic soda is particularly preferred.

[0427] The concentration of the alkaline solution can be determined according to the amount of etching, but is preferably 1 to 50% by mass, more preferably 10 to 35% by mass. When aluminum ions are dissolved in the alkaline solution, the concentration of the aluminum ions is preferably 0.01 to 10% by mass, more preferably 3 to 8% by mass. The temperature of the alkaline solution is preferably 20 to 90°C. The treatment time is preferably 0 to 120 seconds.

[0428] Examples of methods for contacting the aluminum substrate with the alkaline solution include passing the aluminum substrate through a tank containing the alkaline solution, immersing the aluminum substrate in a tank containing the alkaline solution, and spraying the alkaline solution onto the surface of the aluminum substrate.

[0429] <Decontamination treatment>

[0430] In the method for producing the aluminum support of the present invention, it is preferred that after the hydrochloric acid electrolysis treatment or the alkali etching treatment, pickling (decontamination treatment) be performed to remove corrosive organisms remaining on the surface.

[0431] Examples of the acid used include nitric acid, sulfuric acid, and hydrochloric acid. However, other acids may also be used.

[0432] The desmear treatment is performed, for example, by bringing the aluminum substrate into contact with an acidic solution (containing 0.01 to 5 mass % of aluminum ions) such as hydrochloric acid, nitric acid, and sulfuric acid at a concentration of 0.5 to 30 mass %.

[0433] Examples of methods for contacting the aluminum substrate with the acidic solution include passing the aluminum substrate through a tank filled with the acidic solution, immersing the aluminum substrate in a tank filled with the acidic solution, and spraying the acidic solution onto the surface of the aluminum substrate.

[0434] The surface condition of the aluminum substrate after desmear treatment affects the subsequent growth of the natural oxide film. Therefore, the choice of acid, concentration, and temperature conditions are appropriately selected according to the purpose.

[0435] <Water washing>

[0436] The aluminum support manufacturing method of the present invention preferably includes water washing after each of the above-mentioned treatment steps. The final water washing step in particular affects the subsequent growth of the natural oxide film, so it should be thoroughly washed using pure water, well water, tap water, or the like.

[0437] <Anodizing Process>

[0438] The anodizing step is a step of performing an anodizing treatment on the roughened aluminum plate after the hydrochloric acid electrolysis step to form an aluminum anodic oxide film on the aluminum plate.

[0439] Here, the procedure of the anodizing treatment step is not particularly limited, and a known method can be used.

[0440] In the anodizing step, an aqueous solution of sulfuric acid, phosphoric acid, oxalic acid, etc. can be used as an electrolytic cell. For example, the concentration of sulfuric acid can be 100 to 300 g / L.

[0441] The conditions for the anodic oxidation treatment can be appropriately set according to the electrolyte used, but examples thereof include a liquid temperature of 5 to 70° C. (preferably 10 to 60° C.), a current density of 0.5 to 60 A / dm 2 (Preferably 5 to 60 A / dm 2 ), voltage 1-100V (preferably 5-50V), electrolysis time 1-100 seconds (preferably 5-60 seconds) and film weight 0.1-5g / m 2(Preferably 0.2 to 3 g / m 2 ).

[0442] In the present invention, from the viewpoint of further improving the adhesion between the aluminum support and the image recording layer, the anodizing step is preferably a step of performing anodizing using phosphoric acid.

[0443] <Hole expansion process>

[0444] The pore expansion step is a step of performing an etching process on the aluminum plate having the anodic oxide film formed thereon after the anodic oxide step to expand the diameter of micropores in the anodic oxide film (pore diameter expansion process).

[0445] The pore expansion treatment can be performed by bringing the aluminum plate obtained by the above-mentioned anodizing treatment step into contact with an acid aqueous solution or an alkaline aqueous solution. The contact method is not particularly limited, and examples thereof include immersion and spraying.

[0446] [Method for producing lithographic printing plate precursor]

[0447] The above-mentioned method for producing the lithographic printing plate precursor of the present invention is preferably a method of carrying out the following steps in order after the above-mentioned method for producing the aluminum support of the present invention.

[0448] (Undercoat Forming Step) A step of forming an undercoat on the aluminum support obtained in the hole expansion step

[0449] (Image Recording Layer Forming Step) Step of Forming an Image Recording Layer on the Undercoat Layer

[0450] Hereinafter, the steps of each process will be described in detail.

[0451] <Primer Coat Formation Step>

[0452] The primer layer forming step is a step of forming a primer layer on the aluminum support obtained in the pore expanding treatment step.

[0453] The method for producing the undercoat layer is not particularly limited. For example, a method of applying an undercoat layer-forming coating liquid containing a predetermined compound (eg, a compound having a betaine structure) onto the anodic oxide film of an aluminum support can be mentioned.

[0454] The coating liquid for forming an undercoat layer preferably contains a solvent. Examples of the solvent include water and an organic solvent.

[0455] Examples of the method for applying the coating liquid for forming the undercoat layer include various known methods, such as bar coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, doctor blade coating, and roll coating.

[0456] The coating amount (solid content) of the primer layer is preferably 0.1 to 100 mg / m 2 .

[0457] <Image Recording Layer Formation Step>

[0458] The image recording layer forming step is a step of forming an image recording layer on the undercoat layer.

[0459] The method for forming the image recording layer is not particularly limited. For example, a method of applying an image recording layer-forming coating liquid containing predetermined components (the aforementioned infrared absorber, polymerization initiator, polymerizable compound, etc.) onto the undercoat layer is mentioned.

[0460] The coating liquid for forming the image recording layer preferably contains a solvent. Examples of the solvent include water and organic solvents.

[0461] As for the coating method of the coating liquid for forming the image recording layer, the method exemplified as the coating method of the coating liquid for forming the undercoat layer can be mentioned.

[0462] The coating amount (solid content) of the image recording layer varies depending on the application, but is usually preferably 0.3 to 3.0 g / m 2 .

[0463] When a protective layer is provided on the image recording layer, the method for producing the protective layer is not particularly limited. For example, a method of applying a protective layer-forming coating liquid containing predetermined components on the image recording layer can be mentioned.

[0464] In the above embodiment, the micropores 22a in the anodic oxide film 20a are described as being in a substantially straight tubular form. However, the micropores may have other structures as long as the average diameter of the micropores at the surface of the anodic oxide film is within a predetermined range.

[0465] For example, Figure 5 As shown, the aluminum support 12 b may be in a form including an aluminum plate 18 and an anodic oxide film 20 b having micropores 22 b consisting of large-diameter pores 24 and small-diameter pores 26 .

[0466] The micropores 22b in the anodic oxide film 20b are composed of large-diameter pores 24 and small-diameter pores 26. The large-diameter pores 24 extend from the surface of the anodic oxide film to a depth of 10 to 1000 nm (depth D: reference φ). Figure 5 ) position, the small-diameter hole portion 26 is connected to the bottom of the large-diameter hole portion 24, and further extends from the connecting position to a position with a depth of 20 to 2000 nm.

[0467] Hereinafter, the large-diameter hole portion 24 and the small-diameter hole portion 26 will be described in detail.

[0468] The average diameter of the large-diameter pore portion 24 at the surface of the anodic oxide film 20b is the same as the average diameter of the micropore 22a at the surface of the anodic oxide film 20a, and is preferably 10 to 100 nm. From the perspective of balancing contamination resistance and image visual recognition, it is more preferably 15 to 100 nm, further preferably 15 to 60 nm, particularly preferably 20 to 50 nm, and particularly preferably 25 to 40 nm.

[0469] The method for measuring the average diameter of the large-diameter pores 24 at the surface of the anodic oxide film 20 b is the same as the method for measuring the average diameter of the micropores 22 a at the surface of the anodic oxide film 20 a .

[0470] The bottom of the large-diameter pores 24 is located at a depth of 10 to 1000 nm (hereinafter referred to as depth D) from the surface of the anodic oxide film. Specifically, the large-diameter pores 24 extend 10 to 1000 nm in the depth direction (thickness direction) from the surface of the anodic oxide film. This depth is preferably 10 to 200 nm.

[0471] The depth is obtained by taking a photograph of the cross section of the anodic oxide film 20 b (magnification 150,000), measuring the depths of 25 or more large-diameter pores 24, and averaging the measured depths.

[0472] The shape of the large-diameter hole portion 24 is not particularly limited. Examples thereof include a substantially straight tube shape (substantially cylindrical shape) and a conical shape whose diameter decreases in the depth direction (thickness direction). A substantially straight tube shape is preferred.

[0473] like Figure 5 As shown, the small-diameter hole portion 26 is a hole portion that communicates with the bottom portion of the large-diameter hole portion 24 and further extends in the depth direction (thickness direction) from the communication position.

[0474] The average diameter of the small-diameter pores 26 at the communicating locations is smaller than the average diameter of the large-diameter pores, and is preferably 13 nm or less. It is preferably 11 nm or less, and more preferably 10 nm or less. The lower limit is not particularly limited, but is typically 5 nm or more.

[0475] The average diameter of the small-diameter pores 26 is as follows: the surface of the anodic oxide film 20a is observed using FE-SEM with a magnification of 150,000 times, with N=4 images, and 50 pores existing in the 400×600nm area are measured in the obtained 4 images. 2 The diameter of the micropores (small-diameter pores) within the range of 20 and the average value is obtained. In addition, when the large-diameter pores are deep, the upper part of the anodic oxide film 20b (the region having the large-diameter pores) can be cut as needed (for example, by cutting with argon gas), and then the surface of the anodic oxide film 20b can be observed with the above-mentioned FE-SEM to determine the average diameter of the small-diameter pores.

[0476] When the small-diameter hole 26 is not circular, the equivalent circle diameter is used. The “equivalent circle diameter” is the diameter of a circle assuming the shape of the opening to have the same projected area as the opening.

[0477] The bottom of the small-diameter pore 26 extends 20 to 2000 nm in the depth direction from the point where it communicates with the large-diameter pore 24. In other words, the small-diameter pore 26 extends in the depth direction (thickness direction) from the point where it communicates with the large-diameter pore 24, and the depth of the small-diameter pore 26 is 20 to 2000 nm. This depth is preferably 500 to 1500 nm.

[0478] The depth is obtained by taking a photograph of the cross section of the anodic oxide film 20 b (magnification 50,000), measuring the depths of 25 or more small-diameter pores, and averaging the measured depths.

[0479] The shape of the small-diameter hole portion 26 is not particularly limited. Examples thereof include a substantially straight tube shape (substantially cylindrical shape) and a conical shape whose diameter decreases toward the depth direction. A substantially straight tube shape is preferred.

[0480] In addition, the manufacturing method of the aluminum support 12b is not particularly limited, but a manufacturing method in which the following steps are performed in sequence is preferable.

[0481] (Hydrochloric acid electrolytic treatment step) A step of subjecting the aluminum plate to the above-mentioned hydrochloric acid electrolytic treatment

[0482] (First Anodizing Process) A process of anodizing the roughened aluminum plate

[0483] (Pore Enlarging Process) A process of bringing the aluminum plate having the anodic oxide film obtained in the first anodic oxide treatment process into contact with an acid aqueous solution or an alkaline aqueous solution to enlarge the diameter of the micropores in the anodic oxide film.

[0484] (Second Anodizing Process) A process of anodizing the aluminum plate obtained in the hole expanding process

[0485] The procedures of each step can refer to known methods.

[0486] Moreover, in the above Figure 1 , an embodiment using the undercoat layer 14 is described, but as described above, the undercoat layer may not be included in the lithographic printing plate precursor.

[0487] When no primer layer is provided, the image recording layer may be formed after hydrophilizing the aluminum support.

[0488] Examples of the hydrophilization treatment include the known methods disclosed in paragraphs

[0109] to

[0114] of JP-A-2005-254638. Among these, the hydrophilization treatment is preferably performed by immersing the film in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or by coating the film with a hydrophilic vinyl polymer or a hydrophilic compound to form a hydrophilic primer layer.

[0489] The hydrophilization treatment using an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate can be performed according to the methods and procedures described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461.

[0490] [Method for manufacturing lithographic printing plate]

[0491] Next, a method for producing a lithographic printing plate using the lithographic printing plate precursor will be described.

[0492] The method for producing a lithographic printing plate generally includes an exposure step of exposing a lithographic printing plate precursor imagewise (imagewise exposure) to form exposed areas and unexposed areas, and a step of removing the unexposed areas of the imagewise exposed lithographic printing plate precursor.

[0493] More specifically, one embodiment of a method for manufacturing a lithographic printing plate includes the following method for manufacturing a lithographic printing plate, which includes: an exposure step of exposing a lithographic printing plate precursor in an image-like manner (image exposure) to form exposed portions and unexposed portions; and a removal step of removing the unexposed portions of the lithographic printing plate precursor using a developer having a pH of 2 to 12.

[0494] Furthermore, another embodiment of the method for manufacturing a lithographic printing plate includes the following method for manufacturing a lithographic printing plate, which includes: an exposure step of exposing the lithographic printing plate original in an image-like manner (image exposure) to form an exposed portion and an unexposed portion; and an on-press development step of supplying at least one of printing ink and fountain solution to remove the unexposed portion of the lithographic printing plate original exposed in an image-like manner on a printing press.

[0495] These methods are described in detail below.

[0496] The method for producing a lithographic printing plate includes exposing the lithographic printing plate precursor in an imagewise manner (imagewise exposure). Imagewise exposure is performed, for example, by laser exposure through a transparent original having a line image or a halftone dot image, or by laser scanning based on digital data.

[0497] The wavelength of the light source is preferably 750 to 1400 nm. In the case of a light source that emits light with a wavelength of 750 to 1400 nm, it is preferable to use an image recording layer containing an infrared absorbing agent as a sensitizing dye having absorption in this wavelength region.

[0498] As light sources emitting light with a wavelength of 750 to 1400 nm, solid-state lasers and semiconductor lasers that radiate infrared light can be cited. For infrared lasers, the output power is preferably 100 mW or more, the exposure time per pixel is preferably within 20 microseconds, and the irradiation energy is preferably 10 to 300 mJ / cm 2 In order to shorten the exposure time, it is preferable to use a multi-beam laser device. The exposure mechanism can be any of an inner drum method, an outer drum method, and a flatbed method.

[0499] Image exposure can be performed by a conventional method using a plate-making machine, etc. In the case of an on-press development method described below, the lithographic printing plate precursor can be mounted on a printing press and then image exposure can be performed on the printing press.

[0500] The image-exposed lithographic printing plate precursor is developed by removing the unexposed areas using a developer having a pH of 2 to 12 (developer treatment method) or by removing the unexposed areas on a printing press using at least one of printing ink and fountain solution (on-press development method).

[0501] <Developer Processing Method>

[0502] In the developer treatment method, the image-wise exposed lithographic printing plate precursor is treated with a developer having a pH of 2 to 14 to remove the image recording layer in the unexposed areas to produce a lithographic printing plate.

[0503] The developer preferably contains a compound (specific compound) having at least one acid group selected from 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.

[0504] As a method for developing the plate, for example, in the case of manual development, a method in which a developer is thoroughly impregnated into a sponge or cotton wool, the entire surface of the plate is rubbed while developing the plate, and the plate is thoroughly dried after the development is completed. In the case of immersion development, for example, a method in which the plate is immersed in a vat or deep tank filled with developer for approximately 60 seconds, stirred, and then thoroughly dried while rubbing the plate with cotton wool or a sponge is used.

[0505] In the development process, it is preferable to use an apparatus with a simplified structure and a simplified process.

[0506] In conventional development processing, the protective layer is removed in a pre-washing step, followed by development with an alkaline developer, followed by a post-washing step to remove the alkali, a gumming step to perform gumming, and a drying step to dry the film.

[0507] Furthermore, development and gumming can be performed simultaneously with one liquid. As the gum, a polymer is preferred, and a water-soluble high molecular compound and a surfactant are more preferred.

[0508] Furthermore, it is preferred that the protective layer be removed, developed, and coated simultaneously with one solution without a pre-rinsing step. Furthermore, it is preferred that after development and coating, excess developer be removed using a squeeze roller and then dried.

[0509] This treatment may be a method of immersing the substrate in a developer once or twice or more, but preferably, the substrate is immersed in the developer once or twice.

[0510] For immersion, the exposed planographic printing plate precursor may be immersed in a developer tank containing a developer, or the developer may be sprayed onto the surface of the exposed planographic printing plate precursor using a sprayer or the like.

[0511] In addition, even in the case of immersion in a developer two or more times, when the same developer or a developer and a developer (exhausted solution) in which the components of the image recording layer are dissolved or dispersed by the development process are used for immersion two or more times, it is called development treatment with one solution (one-solution treatment).

[0512] Furthermore, it is preferable to use a rubbing member in the development process, and it is preferable to place a rubbing member such as a brush in the developing bath for removing the non-image area of ​​the image recording layer.

[0513] The development process can be performed according to conventional methods, preferably at a temperature of 0 to 60°C, more preferably 15 to 40°C, by immersing the exposed lithographic printing plate precursor in a developer solution and wiping it with a brush, or by pumping the developer solution from an external tank with a pump and spraying it from a nozzle and wiping it with a brush. These development processes can also be performed multiple times in succession. For example, the developer solution can be pumped from an external tank with a pump, sprayed from a nozzle, and wiped with a brush, followed by spraying the developer solution from the nozzle again and wiping it with a brush. When performing the development process using an automatic developer, the developer solution fatigues as the processing volume increases, so it is preferable to use replenisher or fresh developer solution to restore processing capacity.

[0514] The development process of the present invention can also utilize conventionally known adhesive coaters and automatic developers used for PS (Presensitized Plate) and CTP (Computer-to-Plate) plates. When using an automatic developer, for example, a method in which developer injected into a developer tank or injected into an external tank is pumped and sprayed from a nozzle for processing, a method in which the printing plate is immersed and transported in a tank filled with developer using a submerged guide roller, or a so-called one-shot method in which the required amount of substantially unused developer is supplied to each plate for processing can also be employed. Of these methods, a scrubbing mechanism using a brush or double-faced fleece is more preferred. For example, commercially available automatic developers (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. Furthermore, a device in which a laser exposure unit and an automatic developer are partially integrated can be used.

[0515] <On-press development method>

[0516] In the on-press development method, the image-exposed lithographic printing plate precursor is supplied with printing ink and fountain solution on a printing press, and the image-recording layer in the non-image area is removed to produce a lithographic printing plate.

[0517] That is, if the lithographic printing plate precursor is image-exposed and then mounted on a printing press without any developer treatment, or if the lithographic printing plate precursor is mounted on a printing press and then image-exposed on the printing press, and then printing ink and fountain solution are supplied and printing is performed, then in the initial stage of printing, in the non-image area, the image recording layer in the unexposed area is dissolved or dispersed and removed by the supplied printing ink and / or fountain solution, thereby exposing the hydrophilic surface to this area. On the other hand, in the exposed area, the image recording layer solidified by exposure forms an oily ink-receiving area with an oleophilic surface. The compound first supplied to the plate surface can be printing ink or fountain solution, but from the perspective of preventing contamination of the image recording layer components from which the fountain solution has been removed, it is preferred to supply printing ink first.

[0518] In this manner, the lithographic printing plate precursor is developed on-press on a printing press and used directly for printing multiple sheets. Specifically, one embodiment of the printing method of the present invention includes a printing method comprising: an exposure step of imagewise exposing the lithographic printing plate precursor to form exposed and unexposed areas; and a printing step of supplying at least one of a printing ink and a fountain solution, removing the unexposed areas of the lithographic printing plate precursor imagewise exposed on the printing press, and performing printing.

[0519] In the method for producing a lithographic printing plate from the lithographic printing plate precursor of the present invention, the entire surface of the lithographic printing plate precursor may be heated as needed before image exposure, during image exposure, or between image exposure and development, regardless of the development method.

[0520] Example

[0521] Hereinafter, the features of the present invention will be further specifically described by giving examples and comparative examples. The materials, usage amounts, ratios, processing contents and processing steps shown in the following examples can be appropriately changed without departing from the scope of the present invention. Therefore, the scope of the present invention should not be interpreted restrictively by the specific examples shown below.

[0522] [Method for producing an aluminum support]

[0523] An aluminum plate (aluminum alloy plate) of material 1S with a thickness of 0.3 mm was subjected to the following treatments to produce an aluminum support: water washing was performed between all treatment steps, and drainage was performed with nip rolls after the water washing.

[0524] [Example 1]

[0525] <Alkali Etching Treatment>

[0526] The aluminum plate was etched by spraying a caustic soda aqueous solution with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass at 70°C. The plate was then rinsed with water using a spray. The surface, which was then electrochemically roughened, had an aluminum dissolution rate of 5 g / m². 2 .

[0527] <Decontamination Treatment Using Acidic Aqueous Solution>

[0528] Next, desmearing was performed using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate using a sprayer for 3 seconds. The acidic aqueous solution used for desmearing was a 150 g / L sulfuric acid solution at a temperature of 30°C.

[0529] <Electrochemical roughening treatment>

[0530] Next, electrochemical roughening treatment was performed using an electrolyte solution containing 13 g / L hydrochloric acid, 15 g / L aluminum ion, and 1.0 g / L sulfuric acid using alternating current. The electrolyte temperature was 25° C. Aluminum chloride was added to adjust the aluminum ion concentration.

[0531] The waveform of the AC current is a sine wave with symmetrical positive and negative waveforms, a frequency of 50 Hz, a 1:1 ratio between the anode reaction time and the cathode reaction time in one cycle of the AC current, and a current density of 35 A / dm2 based on the peak current of the AC current waveform. 2 The total amount of electricity consumed by the aluminum plate in the anode reaction is 300C / dm 2 For electrolysis, the current was applied at 75C / dm with a power interval of 2.5 seconds. 2 This was done in four steps. A carbon electrode was used as the counter electrode for the aluminum plate. The aluminum plate was then rinsed with water.

[0532] <Alkali Etching Treatment>

[0533] The aluminum plate after electrochemical roughening treatment was etched by spraying a caustic soda aqueous solution with a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass at a temperature of 45°C. The amount of aluminum dissolved on the surface after electrochemical roughening treatment was 0.2 g / m 2 Then, a water washing process was performed.

[0534] <Decontamination Treatment Using Acidic Aqueous Solution>

[0535] Next, a decontamination treatment was performed using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate using a sprayer for 3 seconds. The acidic aqueous solution used for decontamination had a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L. The solution temperature was 35°C.

[0536] <First stage anodizing treatment>

[0537] Utilize based Figure 6 The first stage of anodizing was performed using a direct current electrolytic anodizing apparatus with the structure shown. Anodizing was performed using an electrolyte (aqueous solution) containing sulfuric acid under the conditions shown in Table 1, forming an anodic oxide film of a predetermined film thickness. The "Electrolyte Concentration (g / L)" column in Table 1 indicates the sulfuric acid concentration.

[0538] exist Figure 6 In the anodizing apparatus 610 shown, the aluminum plate 616 is as shown in FIG. Figure 6The aluminum plate 616 is transported as indicated by the arrow in the middle. In a power supply tank 612 containing an electrolyte 618, the aluminum plate 616 is charged with a (+) charge by a power supply electrode 620. Within the power supply tank 612, the aluminum plate 616 is transported upward by rollers 622, redirected downward by nip rollers 624, and then transported to an electrolytic treatment tank 614 containing an electrolyte 626, where it is redirected horizontally by rollers 628. The aluminum plate 616 then passes through an electrolytic electrode 630, receiving a (-) charge, thereby forming an anodic oxide film on its surface. After leaving the electrolytic treatment tank 614, the aluminum plate 616 is transported to subsequent processes. In anodizing apparatus 610, a direction-changing mechanism is formed by rollers 622, nip rollers 624, and rollers 628. Aluminum sheet 616 is conveyed in a mountain-shaped and inverted U-shaped pattern between power supply tank 612 and electrolytic treatment tank 614 by rollers 622, nip rollers 624, and rollers 628. Power supply electrode 620 and electrolytic electrode 630 are connected to a DC power supply 634. A tank wall 632 is disposed between power supply tank 612 and electrolytic treatment tank 614.

[0539] <Hole expansion treatment>

[0540] The anodized aluminum plate was immersed in a caustic soda aqueous solution having a temperature of 40° C., a caustic soda concentration of 5% by mass, and an aluminum ion concentration of 0.5% by mass to perform pore expansion treatment, and then washed with water using a sprayer.

[0541] <Second stage anodizing treatment>

[0542] Utilize based Figure 6 The second stage of anodizing was performed using a direct current electrolytic anodizing apparatus having the structure shown. Anodizing was performed using an electrolyte (aqueous solution) containing sulfuric acid under the conditions shown in Table 1 to form an anodic oxide film having a predetermined film thickness, thereby producing an aluminum support. The "Electrolyte Concentration (g / L)" column in Table 1 indicates the sulfuric acid concentration.

[0543] <Examples 2 to 35, Comparative Examples 1 to 4>

[0544] The liquid temperature and current density of the electrolyte in the <Electrochemical Roughening Treatment> in Example 1 were changed as shown in Table 1, except that the peak current value of the AC current waveform, the total amount of electricity, the conditions for the anodizing treatment, and the conditions for the pore expansion were changed. An aluminum support was produced according to the same procedures as in Example 1.

[0545] [Table 1]

[0546]

[0547] The density of the first specific concave portions, the density of the second specific concave portions, the area ratio of the specific convex portions, the surface area ratio ΔS, and the surface roughness Ra of the anodic oxide film on the surface opposite to the aluminum plate were measured by the above-mentioned method. These results are shown in Table 3 described below.

[0548] Furthermore, regarding the produced aluminum support, the average diameter of the large-diameter pores at the surface of the anodic oxide film (surface average diameter), the average diameter of the communicating positions of the small-diameter pores (internal average diameter), and the depths of the large-diameter pores and the small-diameter pores in the anodic oxide film having micropores were measured by the above-mentioned method. These results are shown in Table 3 below.

[0549] On the anodic oxide film surface of each aluminum support prepared as described above, an undercoat layer was formed using any of the undercoat coating solutions 1 to 3 described below, and an image recording layer was formed on the undercoat layer using any of the image recording layer coating solutions 1 to 3 described below.

[0550] The combinations of the undercoat layer coating liquid and the image recording layer coating liquid used are shown in the following Table 2. As shown in the following Table 2, in the cases of Recipes B to D, a coating layer was further formed on the image recording layer using a protective layer coating liquid.

[0551] The formulations used in the Examples and Comparative Examples are shown in Table 3 below.

[0552] The column “Undercoat layer coating liquid” in Table 2 indicates the type of undercoat layer coating liquid used, “1” indicates undercoat layer coating liquid 1, “2” indicates undercoat layer coating liquid 2, and “3” indicates undercoat layer coating liquid 3.

[0553] The column “Image Recording Layer Coating Liquid” in Table 2 indicates the type of image recording layer coating liquid used, “1” indicates image recording layer coating liquid 1, “2” indicates image recording layer coating liquid 2, and “3” indicates image recording layer coating liquid 3.

[0554] The column “Protective layer coating liquid” in Table 2 indicates the type of protective layer coating liquid used, “1” indicates protective layer coating liquid 1, and “-” indicates that no protective layer coating liquid was used.

[0555] For example, as shown in Table 3 below, in Example 1, Recipe A was used. In Recipe A, as shown in Table 2, the undercoat layer coating liquid 1 was used to form the undercoat layer, and the image recording layer coating liquid 1 was used to form the image recording layer.

[0556] The steps for forming each layer will be described in detail later.

[0557] [Table 2]

[0558]

[0559] [Formation of Primer Layer]

[0560] The anodic oxide film surface of each aluminum support prepared above was coated with a dry coating amount of 100 mg / m 2 Any one of the primer coating solutions 1 to 3 was applied in a manner to form a primer layer.

[0561] (Undercoat coating liquid 1)

[0562] The following components were mixed to prepare an undercoat layer coating liquid 1.

[0563] · Undercoat compound (hereinafter referred to as P-1, 11% by mass aqueous solution): 0.10502 parts by mass

[0564] Sodium gluconate: 0.07000 parts by mass

[0565] Surfactant (EMALEX710, manufactured by NIHON EMULSION Co., Ltd.): 0.00159 parts by mass

[0566] Preservative (Biohope L, manufactured by K.I. Chemical Industry Co., Ltd.): 0.00149 parts by mass

[0567] Water: 2.87190 parts by mass

[0568] P-1 (hereinafter, refer to the structural formula)

[0569] [Chemical Formula 20]

[0570]

[0571] (Undercoat coating liquid 2)

[0572] The following components were mixed to prepare an undercoat layer coating liquid 2.

[0573] Compound for undercoat layer (P-1 above, 11% by mass aqueous solution): 0.0788 parts by mass

[0574] Hydroxyethyldiiminodiacetic acid: 0.0280 parts by mass

[0575] Sodium ethylenediaminetetraacetate tetrahydrate: 0.0499 parts by mass

[0576] Surfactant (EMALEX (registered trademark) 710, NIHON EMULSION Co., Ltd.): 0.0016 parts by mass

[0577] Preservative (Biohope L, K.I Chemical Industry Co., LTD.): 0.0015 parts by mass

[0578] Water: 2.8701 parts by mass

[0579] (Undercoat coating liquid 3)

[0580] The following components were mixed to prepare an undercoat layer coating liquid 3.

[0581] Compound for undercoat layer (P-1 above, 11% by mass aqueous solution): 0.0788 parts by mass

[0582] Sodium gluconate: 0.0700 parts by mass

[0583] Surfactant (EMALEX (registered trademark) 710, NIHON EMULSION Co., Ltd.): 0.0016 parts by mass

[0584] Preservative (Biohope L, K.I Chemical Industry Co., LTD.): 0.0015 parts by mass

[0585] Water: 2.8780 parts by mass

[0586] [Formation of Image Recording Layer]

[0587] The image recording layer coating liquids 1 to 3 were applied by bar coating on the undercoat layer of the aluminum support having the undercoat layer formed thereon, and then dried at 120°C for 40 seconds to form a dry coating weight of 1.3 g / m 2 The image-recording layer is formed to obtain a lithographic printing plate precursor.

[0588] (Image Recording Layer Coating Liquid 1)

[0589] The following components were mixed to prepare an image-recording layer coating liquid 1.

[0590] Infrared absorber (IR-1): 0.02000 parts by mass

[0591] Color developer (S-1): 0.02500 parts by mass

[0592] Electron-accepting polymerization initiator (Int-1): 0.11000 parts by mass

[0593] Electron-donating polymerization initiator (TPB): 0.02500 parts by mass

[0594] Polymerizable compound (M-1): 0.27500 parts by mass

[0595] Anionic surfactant (A-1): 0.00600 parts by mass

[0596] Fluorine-based surfactant (W-1): 0.00416 parts by mass

[0597] 2-Butanone: 4.3602 parts by mass

[0598] 1-Methoxy-2-propanol: 4.4852 parts by mass

[0599] Methanol: 2.2838 parts by mass

[0600] Microgel solution 1: 2.3256 parts by mass

[0601] [Chemical Formula 21]

[0602]

[0603] [Chemical Formula 22]

[0604]

[0605] [Chemical Formula 23]

[0606]

[0607] [Chemical Formula 24]

[0608]

[0609] [Chemical Formula 25]

[0610]

[0611] [Chemical Formula 26]

[0612]

[0613] [Synthesis Method of Polymerizable Compound M-1]

[0614] 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., an amount such that the NCO value of Takenate D-160N and the hydroxyl value of ARONIX M-403 are in a ratio of 1:1), tert-butylbenzoquinone (0.02 parts), and methyl ethyl ketone (11.5 parts) was heated to 65°C. NEOSTANN U-600 (bismuth-based polycondensation catalyst, manufactured by NITTO KASEI CO., LTD., 0.11 parts) was added to the reaction solution, and the mixture was heated at 65°C for 4 hours. The reaction solution was cooled to room temperature (25°C), and methyl ethyl ketone was added to synthesize a solution of urethane acrylate (equivalent to polymerizable compound M-1) having a solids content of 50% by mass. The urethane acrylate solution was subjected to molecular weight fractionation using a reusable GPC (equipment: LC908-C60, columns: JAIGEL-1H-40 and 2H-40 (manufactured by Japan Analytical Industry)) with tetrahydrofuran (THF) as the eluent. The weight average molecular weight was 20,000.

[0615] [Synthesis Method of Microgel Liquid 1]

[0616] Microgel 1 was synthesized by the following steps.

[0617] (Preparation of polyisocyanate compound)

[0618] To a suspension of isophorone diisocyanate (17.78 parts by mass, 80 molar equivalents) and the following polyphenol compound (1) (7.35 parts by mass, 20 molar equivalents) in ethyl acetate (25.31 parts by mass) was added bismuth tris(2-ethylhexanoate) (NEOSTANN U-600, manufactured by NITTO KASEI CO., LTD., 0.043 parts by mass) and stirred. When heat generation was suppressed, the reaction temperature was set to 50°C, and stirring was carried out for 3 hours to obtain an ethyl acetate solution (50% by mass) of the polyvalent isocyanate compound (1).

[0619] [Chemical Formula 27]

[0620]

[0621] (Preparation of Microgels)

[0622] The following oil phase components and aqueous phase components were mixed and emulsified using a homogenizer at 12,000 rpm for 10 minutes. The resulting emulsion was stirred at 45°C for 4 hours, followed by the addition of a 10% aqueous solution (5.20 g) of 1,8-diazabicyclo[5.4.0]undec-7-ene-octanoate (U-CAT SA102, manufactured by San-Apro Ltd.), followed by stirring at room temperature for 30 minutes and allowing to stand at 45°C for 24 hours. The solids concentration was adjusted to 20% by mass using distilled water to obtain Microgel Solution 1. The average particle size, measured by light scattering, was 0.28 μm.

[0623] -Oil phase ingredients-

[0624] (Component 1) Ethyl acetate: 12.0 parts by mass

[0625] (Component 2) An adduct prepared by adding trimethylolpropane (6 mol equivalents) to xylene diisocyanate (18 mol equivalents), followed by the addition of mono-terminal methylated polyoxyethylene (1 mol equivalent, number of repeating oxyethylene units: 90) (50 wt% ethyl acetate solution, manufactured by Mitsui Chemicals, Inc.): 3.76 parts by mass

[0626] (Component 3) Polyisocyanate compound (1) (as a 50% by mass ethyl acetate solution): 15.0 parts by mass

[0627] (Component 4) 65% by mass ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer Company, Inc.): 11.54 parts by mass

[0628] (Component 5) 10% ethyl acetate solution of sulfonate surfactant (PIONIN A-41-C, manufactured by Takemoto Oil & Fat Co., Ltd.): 4.42 parts by mass

[0629] -Aqueous phase ingredients-

[0630] Distilled water: 46.87 parts by mass

[0631] (Image Recording Layer Coating Liquid 2)

[0632] The following components were mixed to prepare an image-recording layer coating liquid 2.

[0633] Infrared absorber (IR-1): 0.0203 parts by mass

[0634] Infrared absorber (IR-2): 0.0068 parts by mass

[0635] Color developer (S-2): 0.0120 parts by mass

[0636] Color developer (S-3): 0.0300 parts by mass

[0637] Electron-accepting polymerization initiator (Int-1): 0.0981 parts by mass

[0638] Electron-donating polymerization initiator (TPB): 0.0270 parts by mass

[0639] Polymerizable compound (M-2): 0.3536 parts by mass

[0640] Tricresyl phosphate: 0.0450 parts by mass

[0641] Anionic surfactant (A-1): 0.0162 parts by mass

[0642] Fluorine-based surfactant (W-1): 0.0042 parts by mass

[0643] 2-Butanone: 5.3155 parts by mass

[0644] 1-Methoxy-2-propanol: 2.8825 parts by mass

[0645] Methanol: 2.3391 parts by mass

[0646] Microgel solution 2: 2.8779 parts by mass

[0647] [Chemical Formula 28]

[0648]

[0649] [Chemical Formula 29]

[0650]

[0651] [Synthesis Method of Polymerizable Compound (M-2)]

[0652] 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., an amount such that the NCO value of Takenate D-160N and the hydroxyl value of ARONIX M-403 are in a ratio of 1:1), tert-butylbenzoquinone (0.02 parts by mass), and methyl ethyl ketone (11.5 parts by mass) was heated to 65°C. NEOSTANN U-600 (bismuth-based polycondensation catalyst, manufactured by NITTOKASEI 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 a urethane acrylate, i.e., a polymerizable compound (M-2), having a solids content of 50% by mass. The molecular weight fraction of the polymerizable compound (M-2) solution was analyzed using a reusable GPC (equipment: LC908-C60, columns: JAIGEL-1H-40 and 2H-40 (manufactured by Japan Analytical Industry)) with tetrahydrofuran (THF) as the eluent. The weight average molecular weight was 20,000.

[0653] [Synthesis Method of Microgel Liquid 2]

[0654] -Preparation of oil phase components-

[0655] A polyfunctional isocyanate compound (PM-200: manufactured by Wanhua Chemical Co.): 6.66 g; a 50% by mass ethyl acetate solution of "Takenate (registered trademark) D-116N (an adduct of trimethylolpropane (TMP), meta-xylylenediisocyanate (XDI), and polyethylene glycol monomethyl ether (EO90) (the following structure)" manufactured by Mitsui Chemicals, Inc.): 5.46 g; a 65% by mass ethyl acetate solution of dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer Company, Inc.): 11.24 g; ethyl acetate: 14.47 g; and PIONIN (registered trademark) A-41-C manufactured by Takemoto Oil & Fat Co., Ltd.: 0.45 g were mixed and stirred at room temperature (25°C) for 15 minutes to obtain an oil phase component.

[0656] [Chemical formula 30]

[0657]

[0658] -Preparation of aqueous phase components-

[0659] As the aqueous phase component, 47.2 g of distilled water was prepared.

[0660] -Microcapsule formation process-

[0661] The aqueous phase component was added to the oil phase component and mixed, and the obtained mixture was emulsified at 12,000 rpm for 16 minutes using a homogenizer to obtain an emulsion.

[0662] 16.8 g of distilled water was added to the obtained 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 to distill off the ethyl acetate from the liquid. Next, 5.12 g of a 10% by mass aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-ene-octanoate (U-CAT SA102, manufactured by San-Apro Ltd.) was added, stirred at room temperature for 30 minutes, and allowed to stand at 45°C for 24 hours. The solid content concentration was adjusted to 20% by mass with distilled water to obtain Microgel Liquid 2. 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.

[0663] (Image Recording Layer Coating Liquid 3)

[0664] The following components were mixed to prepare an image recording layer coating liquid 3.

[0665] Infrared absorber (IR-1): 0.0203 parts by mass

[0666] Infrared absorber (IR-2): 0.0068 parts by mass

[0667] Color developer (S-2): 0.0120 parts by mass

[0668] Color developer (S-3): 0.0300 parts by mass

[0669] Electron-accepting polymerization initiator (Int-1): 0.0981 parts by mass

[0670] Electron-donating polymerization initiator (TPB): 0.0270 parts by mass

[0671] Polymerizable compound (M-2): 0.3536 parts by mass

[0672] Tricresyl phosphate: 0.0125 parts by mass

[0673] Anionic surfactant (A-1): 0.0162 parts by mass

[0674] PIONIN A-41-C (manufactured by Takemoto Oil & Fat Co., Ltd., 70% methanol solution): 0.0081 parts by mass

[0675] Fluorine-based surfactant (W-1): 0.0042 parts by mass

[0676] 2-Butanone: 5.3155 parts by mass

[0677] 1-Methoxy-2-propanol: 2.8825 parts by mass

[0678] Methanol: 2.3391 parts by mass

[0679] Microgel solution 2: 2.8779 parts by mass

[0680] [Formation of protective layer]

[0681] The protective layer coating liquid 1 was bar-coated on the image recording layer of the aluminum support on which the image recording layer was formed, and then dried at 120° C. for 60 seconds to form a dry coating weight of 0.80 g / m 2 protective layer.

[0682] (Protective layer coating liquid 1)

[0683] The following components were mixed to prepare a protective layer coating liquid 1.

[0684] Water: 1.0161 parts by mass

[0685] METOLOSE SM04: 0.0600 parts by mass

[0686] FS-102 (17% aqueous dispersion): 0.1177 parts by mass

[0687] RAPISOL A-80 (80% aqueous solution): 0.0063 parts by mass

[0688] [Evaluation method]

[0689] <Printing durability with oil-based detergents>

[0690] The lithographic printing plate precursors obtained in each of the Examples and Comparative Examples were exposed using a Luxel PLATESETTER T-6000III manufactured by Fujifilm Corporation, equipped with an infrared semiconductor laser, at an external drum speed of 1000 rpm, a laser output of 70%, and a resolution of 2400 dpi. The exposed image consisted of a solid image and a 50% dot pattern using 20 μm dot FM (Frequency Modulation) screening.

[0691] The exposed lithographic printing plate precursor was mounted on the plate cylinder of a Lithrone 26 printing press manufactured by Komori Corporation without undergoing development. Using a fountain solution of Ecolity-2 (manufactured by Fujifilm Corporation) / tap water = 2 / 98 (volume ratio) and Values-G(N) black ink (manufactured by Dainippon Ink and Chemicals, Inc.), the fountain solution and ink were supplied using the Lithrone 26's standard automatic print start method for on-press development. Printing was then performed on Tokubishi Art (76.5 kg) paper at a printing speed of 10,000 sheets per hour. As the number of printed sheets increases, the image recording layer gradually wears away, causing the ink density on the printed material to decrease. The number of printed sheets at the point where the density of the solid image begins to decrease, as observed by the naked eye, is used as the reference number of printed sheets.

[0692] Next, a step was included in which the plate surface was wiped with a cleaner (MultiCleaner manufactured by Fujifilm Corporation) every 5,000 printed sheets. The number of printed sheets at the point where the density of the solid image began to decrease visually was determined using the same method as above. This number of printed sheets was used as the evaluation number of printed sheets.

[0693] Next, the index value obtained by the following formula (X) was calculated using the reference print count and the evaluation print count, and evaluation was performed according to the following criteria.

[0694] Formula (X): Index value = (reference number of printed sheets - evaluation number of printed sheets) / reference number of printed sheets

[0695] The larger the index value, the smaller the change in printing durability is even when a step of wiping the plate surface with a detergent is added, and it can be said that the oil-based detergent has excellent printing durability.

[0696] -Evaluation Criteria-

[0697] 6: The index value is above 98% and less than 100%

[0698] 5: The index value is above 95% and less than 98%

[0699] 4: The index value is above 80% and less than 95%

[0700] 3: The index value is 60% or more and less than 80%

[0701] 2: The index value is 40% or more and less than 60%

[0702] 1: The indicator value is less than 40%

[0703] In Table 3, “First specific concave portion (number / mm 2 The column ")" shows the density of the first specific recessed portions (number / mm 2 ).

[0704] In Table 3, “Second specific concave portion (number / mm 2 The column ")" shows the density of the second specific recessed portions (number / mm 2 ).

[0705] In Table 3, the column "Specific convex portion area ratio (%)" shows the area ratio (%) of the specific convex portions.

[0706] [Table 3]

[0707]

[0708] 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.

[0709] According to the comparison of Examples 1 to 5, it was confirmed that the number of the first specific recessed portions was 6000 / mm. 2 Above (preferably 8000 pieces / mm 2 In the above cases), the effect is more excellent.

[0710] Comparison between Example 5 and Example 6 confirmed that when the area ratio of the specific convex portions is 10% or less (preferably 8% or less), a more excellent effect is achieved.

[0711] Comparison of Examples 7 and 8 confirmed that the effect was more excellent when the area ratio of the specific protrusions was 13% or less. Furthermore, comparison of Examples 8 with Examples 9 and 10 confirmed that the effect was more excellent when the area ratio of the specific protrusions was 10% or less. Furthermore, comparison of Examples 9 and 10 with Example 12 confirmed that the effect was more excellent when the area ratio of the specific protrusions was less than 3%.

[0712] Furthermore, the evaluation of the oil-based detergent printing durability of Examples 9 and 11 was both "5". In Example 11, the number of the first specific recessed portions was less than 6000 / mm. 2 , but the number of the second specific protrusions is 6000 / mm 2 As described above, Example 9 and Example 11 have the same evaluation. That is, it was confirmed that the number of the second specific protrusions was 6000 / mm 2 In the above case, the effect is more excellent.

[0713] According to Examples 12 to 14, it was confirmed that the area ratio of the specific convex portion was 10% or less and the number of the second specific concave portions was 6000 / mm. 2 As described above, when the surface area ratio ΔS is 45% or more, the most excellent effect can be obtained.

[0714] Examples 15 to 19 confirmed that the effect was more excellent when the specific convex portion area ratio was 10% or less and the surface area ratio ΔS was 20% or greater. Furthermore, it was confirmed that the effect was even more excellent when the specific convex portion area ratio was 10% or less and the surface area ratio ΔS was 45% or greater.

[0715] Comparison between Example 18 and Example 23 confirmed that the effect was more excellent when the area ratio of the specific convex portions was 7% or less and the surface area ratio ΔS was 20% or more.

[0716] Comparison between Example 15 and Example 20 confirmed that the effect was more excellent when the area ratio of the specific convex portions was 7% or less and the surface area ratio ΔS was 45% or more.

[0717] <Example 36 to Example 39>

[0718] The liquid temperature and current density of the electrolyte in the <Electrochemical Roughening Treatment> in Example 1 were changed as shown in Table 4, except that the peak current value of the AC current waveform, the total amount of electricity, the conditions for the anodizing treatment, and the conditions for the pore expansion were changed. An aluminum support was produced according to the same procedures as in Example 1.

[0719] [Table 4]

[0720]

[0721] The density of the second specific concave portions, the area ratio of the specific convex portions, the surface area ratio ΔS, and the surface roughness Ra of the anodic oxide film on the surface opposite to the aluminum plate were measured using the above-described method. These results are shown in Table 5 below.

[0722] Furthermore, regarding the produced aluminum support, the average diameter of the large-diameter pores at the surface of the anodic oxide film (surface average diameter), the average diameter of the communicating positions of the small-diameter pores (internal average diameter), and the depths of the large-diameter pores and the small-diameter pores in the anodic oxide film having micropores were measured by the above-mentioned method. These results are shown in Table 5 below.

[0723] The obtained aluminum support was used to carry out the above-described steps of [Formation of Undercoat Layer] and [Formation of Image Recording Layer] to prepare a lithographic printing plate precursor, and the <Oil-Based Cleanser Printing Durability> was evaluated. The results are shown in Table 5 below.

[0724] [Table 5]

[0725]

[0726] 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.

[0727] Comparison of Examples 15 and 16 confirmed that the effect was more excellent when the area ratio of the specific protrusions was 13% or less. Furthermore, comparison of Examples 16 and 17 confirmed that the effect was more excellent when the area ratio of the specific protrusions was 10% or less. Furthermore, comparison of Examples 17 and 18 confirmed that the effect was more excellent when the area ratio of the specific protrusions was less than 3%.

[0728] Explanation of symbols

[0729] ta-anodic reaction time, tc-cathodic reaction time, tp-time from 0 to peak current, Ia-peak current on the anode circulation side, Ic-peak current on the cathode circulation side, 10-lithographic printing plate precursor, 12a, 12b-aluminum support, 14-undercoat layer, 16-image recording layer, 18-aluminum plate, 20a, 20b-anodic oxide film, 22a, 22b-micropores, 24-large diameter pore portion, 26-small diameter pore portion, 50-main electrolytic cell, 5 1-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 device, 612-power supply tank, 614-electrolytic treatment tank, 616-aluminum plate, 618, 626-electrolyte, 620-power supply electrode, 622, 628-rollers, 624-clamping roller, 630-electrolytic electrode, 632-tank wall, 634-DC power supply.

Claims

1. A lithographic printing plate precursor comprising an aluminum support and an image recording layer disposed on the aluminum support, wherein: The aluminum support includes an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate. The image recording layer is arranged on the anodic oxide film side of the aluminum support. The area ratio of projections having a height of 0.80 μm or greater from the average surface measured in a 400 μm×400 μm range on the image recording layer side surface of the aluminum support using a non-contact three-dimensional roughness meter was 20% or less.

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

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

4. The lithographic printing plate precursor according to claim 1 or 2, wherein The area ratio of the convex portions having a height of 0.80 μm or more from the average surface is 7% or less.

5. A lithographic printing plate precursor comprising an aluminum support and an image recording layer disposed on the aluminum support, wherein: The aluminum support includes an aluminum plate and an aluminum anodic oxide film disposed on the aluminum plate. The image recording layer is arranged on the anodic oxide film side of the aluminum support. The density of recessed portions having a depth of 0.40 μm or more from the average surface was measured in a 400 μm×400 μm area on the surface of the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter and was 4000 / mm 2 above.

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

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

8. The lithographic printing plate precursor according to claim 5 or 6, wherein The area ratio of projections having a height of 0.80 μm or greater from the average surface measured in a 400 μm×400 μm range on the image recording layer side surface of the aluminum support using a non-contact three-dimensional roughness meter was 20% or less.

9. The lithographic printing plate precursor according to claim 1 or 5, wherein The density of recessed portions having a depth of 0.20 μm or more from the average surface was measured in a 400 μm×400 μm area on the surface of the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter and was 6000 / mm 2 above.

10. The lithographic printing plate precursor according to claim 1 or 5, wherein The surface area ratio ΔS calculated by the following formula (1) from the actual area Sx obtained by the approximate three-point method based on three-dimensional data obtained by measuring 512×512 points in a range of 25 μm×25 μm on the surface of the image recording layer side of the aluminum support using an atomic force microscope and the geometrically measured area S0 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, wherein The surface area ratio ΔS is 45% or more.

13. The lithographic printing plate precursor according to claim 1, wherein The area ratio of protrusions having a height of 0.80 μm or more from the average surface, measured in a 400 μm×400 μm range on the surface of the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter, is 10% or less. The surface area ratio ΔS calculated by the following formula (1) from the actual area Sx obtained by the approximate three-point method based on three-dimensional data obtained by measuring 512×512 points in a range of 25 μm×25 μm on the surface of the image recording layer side of the aluminum support using an atomic force microscope and the geometrically measured area S0 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 The area ratio of the convex portions having a height of 0.80 μm or more from the average surface is 7% or less.

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

17. The lithographic printing plate precursor according to claim 1, wherein The area ratio of protrusions having a height of 0.80 μm or more from the average surface, measured in a 400 μm×400 μm range on the surface of the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter, is 10% or less. The density of recessed portions having a depth of 0.20 μm or more from the average surface was measured in a 400 μm×400 μm area on the surface of the image recording layer side of the aluminum support using a non-contact three-dimensional roughness meter and was 6000 / mm 2 above, The surface area ratio ΔS calculated by the following formula (1) from the actual area Sx obtained by the approximate three-point method based on three-dimensional data obtained by measuring 512×512 points in a range of 25 μm×25 μm on the surface of the image recording layer side of the aluminum support using an atomic force microscope and the geometrically measured area S0 is 45% or more, ΔS=(Sx-S0) / S0×100(%) (1).

18. The lithographic printing plate precursor according to claim 1 or 5, wherein The surface roughness Ra of the surface of the aluminum support on the image recording layer side, measured using a contact-type surface roughness meter, was 0.45 μm or less.

19. The lithographic printing plate precursor according to claim 1 or 5, wherein The anodic oxide film has micropores. The micropores are composed of a large-diameter pore portion and a small-diameter pore portion, wherein the large-diameter pore portion extends from the surface of the anodic oxide film to a depth of 10 nm to 1000 nm, and the small-diameter pore portion is connected to the bottom of the large-diameter pore portion and extends from the connected position to a depth of 20 nm to 2000 nm. The average diameter of the large-diameter pores at the surface of the anodic oxide film is 15 nm to 60 nm. An average diameter of the small-diameter hole portion at the communication position is smaller than an average diameter of the large-diameter hole portion.

20. A method for manufacturing a lithographic printing plate, comprising: an exposing step of exposing the lithographic printing plate precursor according to any one of claims 1 to 19 in an imagewise manner to form exposed areas and unexposed areas; and The removing step is to remove the unexposed areas of the imagewise exposed planographic printing plate precursor.

21. A printing method comprising: an exposing step of exposing the lithographic printing plate precursor according to any one of claims 1 to 19 in an imagewise manner to form exposed areas and unexposed areas; and The printing step includes supplying at least one of printing ink and fountain solution, removing unexposed portions of the image-wise exposed lithographic printing plate precursor on a printing press, and performing printing.

22. A method for producing an aluminum support for the lithographic printing plate precursor according to any one of claims 1 to 19, the method comprising: In the hydrochloric acid electrolytic treatment process, the aluminum plate is subjected to electrolysis in a hydrochloric acid treatment solution optionally containing sulfuric acid, at a temperature of 30°C or less and a total charge of 400C / dm 2 Below, and the peak current value of the AC current waveform is 80A / dm 2 Under the following conditions, AC electrolysis was performed to produce a roughened aluminum plate. When the hydrochloric acid treatment liquid contains sulfuric acid, the ratio of the content of sulfuric acid to the content of hydrochloric acid is 0.1 or less.

23. The method for producing an aluminum support according to claim 22, wherein: After the hydrochloric acid electrolysis treatment step, the following steps are sequentially included: an anodizing step of performing an anodizing treatment on the roughened aluminum plate to form an aluminum anodic oxide film on the aluminum plate; and In the pore expansion step, the aluminum plate having the anodic oxide film formed thereon is subjected to an etching process to expand the diameter of the micropores in the anodic oxide film.

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