Direct-drawing-type waterless lithographic printing plate precursor, and method for producing waterless lithographic printing plate using said direct-drawing-type waterless lithographic printing plate precursor

Abstract

A direct drawing type waterless planographic printing plate precursor having a primer layer, a heat-sensitive layer, and a silicone rubber layer in this order on a support, the direct drawing type waterless planographic printing plate precursor being characterized in that: the width of the primer layer in a cross section thereof is in the range of 750 [mu] m; the sum of the total area of the protruding portions compared with the reference height of the primer layer and the total area of the recessed portions compared with the reference height of the primer layer is 0-60 [mu] m2. Provided is a direct drawing type waterless planographic printing original plate with which it is possible to obtain a waterless planographic printing plate having good image reproducibility and printing durability in a large-size plate and having little printing irregularities.

Description

Technical Field

[0001] The present invention relates to a direct drawing type waterless planographic printing plate precursor and a method for producing a waterless planographic printing plate using the direct drawing type waterless planographic printing plate precursor. Background Art

[0002] There are various printing methods, including letterpress, gravure, screen printing, lithography, and inkjet printing, each utilizing its own unique characteristics. Among these, lithography offers advantages over other printing methods, such as producing highly detailed printed products. The printing plates used in lithography (hereinafter referred to as lithographic printing plates) are broadly divided into two types: horizontal lithographic plates, where the non-lined areas are rendered ink-repellent by a fountain solution, and horizontal lithographic plates, where the non-lined areas are rendered ink-repellent by a fountain solution.

[0003] Various proposals have been made to date regarding technologies for obtaining waterless planographic printing plates that use silicone rubber as the ink-repellent non-line portion. Examples include a direct-drawing waterless planographic printing plate precursor comprising a cross-linked polymer image layer and an oleophobic top layer in this order on a metal plate having a roughened surface (see, for example, Patent Document 1), and a direct-drawing waterless planographic printing plate precursor comprising at least a heat-insulating layer, a heat-sensitive layer, and a silicone rubber layer in this order on a substrate (see, for example, Patent Document 2).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent No. 10,011,137

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2004-334025 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] In recent years, lithographic printing has been used in applications such as flexible packaging and building materials. These applications are increasingly demanding larger printed materials. Consequently, large-scale waterless lithographic printing plates are expected to have improved image reproducibility, reduced printing unevenness, and increased press life.

[0010] The direct-drawing waterless planographic printing plate precursor described in Patent Document 1 thermally destroys the cross-linked polymeric image layer by irradiation with a near-infrared laser. The thermally destroyed cross-linked polymeric image layer and the oleophobic top layer above it are then removed by a development process, thereby producing a waterless planographic printing plate. However, due to the roughening of the metal plate surface, the thickness of the cross-linked polymeric image layer disposed on the protrusions of the metal plate surface tends to decrease. This reduces the heat generation efficiency of the cross-linked polymeric image layer in these thinned portions, resulting in reduced image reproducibility and, consequently, the occurrence of uneven printing. Furthermore, since the roughening of the metal plate surface also tends to form irregularities on the surface of the cross-linked polymeric image layer, stress concentrates on the protrusions during printing, which in turn tends to damage the silicone rubber layer located above the protrusions, creating issues with printing durability.

[0011] The direct-drawing waterless planographic printing plate precursor described in Patent Document 2 forms a latent image on the upper portion of the heat-sensitive layer by irradiation with a near-infrared laser, and the silicone rubber layer corresponding to the line portion of the latent image is removed by subsequent development treatment, thereby obtaining a waterless planographic printing plate. Compared with Patent Document 1, since the surface roughness of the substrate is low and a heat-insulating layer is provided between the substrate and the heat-sensitive layer, the thickness of the heat-sensitive layer tends to become uniform, thereby suppressing the reduction of image reproducibility and printing durability and uneven printing. However, the heat-insulating layer solutions specifically exemplified in Patent Document 2 all have a high solid content concentration and high viscosity, and therefore, in large-scale direct-drawing waterless planographic printing plate precursors, there is a tendency for thin film portions and convex portions to be easily formed on the heat-sensitive layer, and further improvements in image reproducibility, printing durability, and suppression of uneven printing are required.

[0012] Therefore, an object of the present invention is to provide a direct drawing waterless planographic printing plate precursor capable of obtaining a waterless planographic printing plate having good image reproducibility and press life in a large-size plate and with little printing unevenness.

[0013] Means for solving problems

[0014] In order to solve the above-mentioned problems, the present invention mainly has the following configurations.

[0015] (1) A direct-drawing waterless planographic printing plate precursor comprising a primer layer, a heat-sensitive layer, and a silicone rubber layer in this order on a support, wherein, in a cross section of the primer layer, within a width of 750 μm, the sum of the areas of portions protruding from a reference height of the primer layer and the sum of the areas of portions recessed from the reference height of the primer layer is 0 to 60 μm 2 .

[0016] (2) According to the direct drawing type waterless planographic printing plate precursor described in (1), within the range of 750 μm of the width of the primer layer in the above-mentioned cross section, the number of intersections between the reference height of the above-mentioned primer layer and the line representing the interface between the above-mentioned primer layer and the above-mentioned heat-sensitive layer is 0 to 600.

[0017] (3) A direct drawing waterless planographic printing plate precursor comprising a primer layer, a heat-sensitive layer, and a silicone rubber layer in this order on a support, wherein the maximum peak height on the surface of the primer layer is 0.5 μm or less.

[0018] (4) The direct drawing waterless planographic printing plate precursor according to any one of (1) to (3), wherein the thickness of the thinnest portion of the heat-sensitive layer is 0.2 μm or more.

[0019] (5) The direct drawing waterless planographic printing plate precursor according to any one of (1) to (4), wherein the thickness of the thinnest portion of the primer layer is 1 μm or more.

[0020] (6) The direct-drawing waterless planographic printing plate precursor according to any one of (1) to (5), wherein, within a range of 750 μm in width of the heat-sensitive layer in a cross section, the sum of the areas of the portions protruding from the reference height of the heat-sensitive layer and the sum of the areas of the portions recessed from the reference height of the heat-sensitive layer is 0 to 30 μm 2 .

[0021] (7) The direct drawing waterless planographic printing plate precursor according to any one of (1) to (6), wherein the average thickness of the primer layer is 2 to 500 μm.

[0022] (8) The direct drawing waterless planographic printing plate precursor according to any one of (1) to (7), wherein the heat-sensitive layer has an average thickness of 0.5 to 2 μm.

[0023] (9) The direct drawing waterless planographic printing plate precursor according to any one of (1) to (8), wherein the average thickness of the silicone rubber layer is 3.2 to 4.8 μm.

[0024] (10) The direct drawing waterless planographic printing plate precursor according to any one of (1) to (9), wherein the heat-sensitive layer is a heat-destructible type.

[0025] (11) The direct drawing waterless planographic printing plate precursor according to any one of (1) to (10), wherein the silicone rubber layer includes a hard domain.

[0026] (12) The direct-drawing waterless planographic printing plate precursor according to any one of (1) to (11), wherein, within the range of 750 μm of the width of the support in the cross section, the sum of the areas of the portions protruding from the base height of the support and the sum of the areas of the portions recessed from the base height of the support is 0 to 300 μm. 2 .

[0027] (13) A method for manufacturing a waterless planographic printing plate, comprising the following steps: an exposure step of irradiating a laser onto a direct-drawing type waterless planographic printing plate original described in any one of (1) to (12) to form a latent image; and a development step of removing a silicone rubber layer corresponding to a line portion of the latent image.

[0028] (14) According to the method for manufacturing a waterless planographic printing plate described in (13), in the exposure step of forming the latent image, an AM screen or an AM / FM hybrid screen having a precision equivalent to 180 to 650 lines of an AM screen is used.

[0029] Effects of the Invention

[0030] The direct drawing waterless planographic printing plate precursor of the present invention can provide a waterless planographic printing plate having good image reproducibility and press life in a large-size plate and with little printing unevenness. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic cross-sectional view showing the relationship between the reference height of the support and the support in an example of a conventionally known direct drawing type waterless planographic printing plate precursor.

[0032] Figure 2 This is a schematic cross-sectional view of an example of a conventionally known direct-drawing waterless planographic printing plate precursor.

[0033] Figure 3 This is a schematic cross-sectional view of an example of the direct drawing waterless planographic printing plate precursor of the present invention.

[0034] Figure 4 This is a schematic cross-sectional view showing the relationship between the reference height of the primer layer and the primer layer in an example of a conventionally known direct drawing type waterless planographic printing plate precursor.

[0035] Figure 5 This is a schematic cross-sectional view showing the intersection of a reference height of a primer layer and a line representing the interface between the primer layer and the heat-sensitive layer in an example of a conventionally known direct drawing type waterless planographic printing plate precursor.

[0036] Figure 6 This is a schematic cross-sectional view showing the relationship between the reference height of the heat-sensitive layer and the heat-sensitive layer in an example of a conventionally known direct-drawing waterless planographic printing plate precursor. DETAILED DESCRIPTION

[0037] The so-called direct-drawing type waterless planographic printing plate precursor (hereinafter, sometimes abbreviated as "printing plate precursor") is a precursor before the ink adhesion part / ink repelling part is formed on the waterless planographic printing plate (hereinafter, sometimes abbreviated as "printing plate"). The direct-drawing type waterless planographic printing plate precursor involved in the present invention has a primer layer, a heat-sensitive layer and a silicone rubber layer on the support in sequence. The support has the function of maintaining the shape of the printing plate precursor and the printing plate. The primer layer has the function of suppressing the influence of the unevenness of the support surface, bonding the support to the heat-sensitive layer, and heat insulation. The heat-sensitive layer has the function of forming a latent image by the heat generated by laser absorption and the function of forming a line portion to which ink is attached in the printing plate. However, in the case where the heat-sensitive layer is of the heat-destructible type described later, the heat-sensitive layer destroyed by the heat generated by laser absorption is removed in the platemaking process, so that in the printing plate, the ink is not attached to the heat-sensitive layer but to the surface of the primer layer. The silicone rubber layer has the function of repelling ink and forms a non-line portion in the printing plate. Furthermore, a direct-drawing lithographic printing plate precursor refers to a lithographic printing plate precursor on which an image can be directly written from an original using a laser, and a latent image can be formed by exposure without requiring a separate original film.

[0038] First, the support will be described.

[0039] The material of the support is preferably a dimensionally stable metal or plastic. Specifically, examples include metals such as aluminum, iron, zinc, and copper; alloys primarily composed of these metals; plastics such as epoxy resins, phenolic resins, ester resins, vinyl ester resins, amide resins, and imide resins; and fiber-reinforced plastics comprising these plastics and fibers such as glass fiber, carbon fiber, aramid fiber, polyethylene fiber, Zylon fiber, and boron fiber. Aluminum alloys and fiber-reinforced plastics are preferred due to their light weight, ease of handling, and superior printability.

[0040] As the shape of the support, for example, a plate, a roll, a cylinder, a column, etc. can be cited. In the case of using a cylinder or columnar support, a seamless waterless planographic printing plate precursor capable of printing a continuous pattern is obtained. As the shape of the support for the seamless waterless planographic printing plate precursor, a cylindrical shape is more preferred in terms of being lighter and easier to handle. In terms of being able to print immediately after the printing plate is produced from the printing plate precursor, the cylindrical support is preferably the plate cylinder of the printing press. In particular, in terms of being able to carry out a series of processes until the seamless waterless planographic printing plate is produced outside the printing press, and in terms of operations such as regeneration of the support after printing, it is more preferred that the cylindrical support be a plate cylinder sleeve that can be disassembled and mounted on the plate cylinder shaft of the printing press.

[0041] As the size of the support, when the support is plate-shaped, it is sufficient to select a size (length, width, thickness, etc.) suitable for the printing press used. In addition, when the support is cylindrical, it is sufficient to select a diameter and width appropriate for the plate cylinder of the printing press used.

[0042] As the roughness of the support surface, it is preferably 0.4 μm or less in terms of arithmetic mean roughness (Ra). By making the Ra of the support surface 0.4 μm or less, the surface of the primer layer is easy to smooth, and image reproducibility and printing resistance can be further improved, and printing unevenness can be further suppressed. Ra is more preferably 0.3 μm or less, and more preferably 0.2 μm or less. On the other hand, if the Ra of the support surface is more than 0.04 μm, it is possible to manufacture only by rolling without implementing a grinding process. Therefore, in terms of improving the productivity of the support, the Ra of the support surface is preferably 0.04 μm or more. As mentioned above, the previous printing plate precursor has image reproducibility and printing resistance due to the roughening of the support surface, and the problem of uneven printing is easy to occur. However, in the present invention, by smoothing the primer layer surface as described later, the effect of the present invention is more significantly exerted when the Ra of the support surface is more than 0.04 μm. The Ra of the support surface is more preferably 0.06 μm or more, and more preferably 0.08 μm or more.

[0043] The Ra of the support surface can be measured using a surface roughness meter: "(Registered trademark) 1400G (manufactured by Tokyo Seimitsu Co., Ltd.) was used for measurement.

[0044] As another indicator of the smoothness of the support surface, in the present invention, a reference height of the support is set in the cross section of the printing plate precursor, and the concavity and convexity of the support relative to the reference height are focused on. Preferably, within a width range of 750 μm of the support in the cross section of the printing plate precursor, the sum of the areas of the portions of the support that protrude relative to the reference height of the support (hereinafter sometimes abbreviated as "convex area") and the areas of the portions of the support that are recessed relative to the reference height of the support (hereinafter sometimes abbreviated as "concave area") is 0 to 300 μm. 2 .

[0045] Here, the convex and concave areas within a 750 μm width of the support in a cross section of the printing plate precursor can be determined by SEM observation of the cross section of the printing plate precursor as described below. It should be noted that in the present invention, in order to sufficiently suppress measurement variations in the convex and concave areas of the support and appropriately evaluate the smoothness of the support surface, the observation range is set to 750 μm of the support width.

[0046] By making the total area of ​​the convex portion and the concave portion of the support 300 μm 2 The surface of the primer layer as the upper layer is also easier to smooth, making it easier to design the maximum peak height and the sum of the convex and concave areas of the primer layer described later to fall within the preferred range. As a result, image reproducibility and printing durability can be further improved, and printing unevenness can be further suppressed. The sum of the convex and concave areas of the support is more preferably 240 μm. 2 Below, more preferably 180 μm 2 On the other hand, if the sum of the area of ​​the convex portion and the area of ​​the concave portion of the support is 30 μm 2 The above can be manufactured by rolling without polishing. Therefore, in terms of improving the productivity of the support, the sum of the convex area and the concave area of ​​the support is preferably 30 μm. 2 As described above, the conventional printing plate precursor has problems such as reduced image reproducibility and printing durability due to the roughening of the support surface, and easy occurrence of uneven printing. However, in the present invention, by smoothing the surface of the primer layer as described later, the total area of ​​the convex portion and the concave portion of the support is 30 μm. 2 In the above case, the effect of the present invention is more significantly exerted. The sum of the area of ​​the convex portion and the area of ​​the concave portion of the support is more preferably 45 μm 2 More preferably, 60 μm 2 above.

[0047] use Figure 1 The relationship between the reference height of the support and the support in the present invention will be described. Figure 1 The present invention is a cross-sectional schematic diagram showing an example of a conventionally known direct-drawing type waterless planographic printing plate original, which comprises a support 1, a primer layer 2, a heat-sensitive layer 3, and a silicone rubber layer 4 from the bottom. When the support 1 is an aluminum alloy plate, rolling marks formed during rolling and unevenness formed by chemical, physical, or electrochemical grinding treatment are generally present on its surface. In the present invention, the height of the surface position of the support obtained by the following operation assuming that the support surface is smooth is defined as the base height c0 of the support, the portion protruding toward the primer layer 2 side compared with the base height c0 of the support is represented as the portion protruding compared with the base height c1 of the support, and the portion recessed toward the opposite side of the primer layer 2 compared with the base height c0 of the support is represented as the portion recessed compared with the base height c2 of the support. Here, in the cross-sectional SEM image of the printing plate precursor, the average height of the support is calculated by dividing the area of ​​the support portion of the cross-sectional SEM image by the observed width of the cross-sectional SEM image. The resulting average height is set as the height from the bottom edge of the cross-sectional SEM image to determine the reference height c0 of the support. Details are described below.

[0048] The sum of the convex area and the concave area of ​​the support can be obtained by observing the cross section of the printing plate original by SEM. In more detail, the printing plate original is cut into 30 samples of 10mm×10mm size in such a way that 30 different positions in the width direction become the approximate center of the sample. Here, the 30 different positions in the width direction are selected as follows. The position 100mm away from one end in the width direction of the printing plate original is set as the first position, the position 100mm away from the other end is set as the 30th position, and the points located at the length of the length between the first and the 30th positions divided into 29 equal parts are set as the 2nd to 29th positions. For example, in the case of a printing plate original with a width of 1070mm, the position 100mm away from one end in the width direction becomes the first position, the position 970mm becomes the 30th position, and the points located at the length (30mm) of the 870mm between them divided into 29 equal parts become the 2nd to 29th positions. Specifically, the printing plate precursor was examined at 30 locations in the width direction, at positions 100, 130, 160, 190, 220, 250, 280, 310, 340, 370, 400, 430, 460, 490, 520, 550, 580, 610, 640, 670, 700, 730, 760, 790, 820, 850, 880, 910, 940, and 970 mm from one end. Each of the 30 cut samples was resin-embedded, and then cross-sections perpendicular to the rolling grain of the aluminum substrate were prepared using the BIB method. The observation surface was then subjected to a conductive treatment (Pt coating) to prepare samples for cross-sectional observation. The resulting cross-sectional samples were observed using a scanning electron microscope (SEM) under the following observation conditions: backscattered electron imaging, an accelerating voltage of 3.0 kV, and a magnification of 5,000x. In the obtained 30 cross-sectional SEM images, a line of the reference height of the support is drawn in a manner parallel to the line representing the interface between the silicone rubber layer and the embedding resin. The reference height of the support is calculated by dividing the area of ​​the support portion in the cross-sectional SEM image by the observed width of each cross-sectional SEM image to obtain the average height of the support, and the obtained average height is set to the height from the bottom edge of the cross-sectional SEM image (however, when the bottom edge of the support is observed in the SEM image, it is the height from the bottom edge of the support) so that it can be obtained. In each cross-sectional SEM image, the total area of ​​the convex portion and the area of ​​the concave portion are calculated for the width of the support 25 μm located in the center of the width direction of the image, and the total values ​​of the convex portion area and the concave portion area of ​​the 30 cross-sectional SEM images are all added up, so that the total area of ​​the convex portion and the concave portion can be obtained within the range of the width of the support 750 μm in the cross section.

[0049] Examples of means for bringing the total area of ​​the convex portions and the concave portions of the support into the above range include forming rolling marks during rolling and performing chemical, physical, or electrochemical polishing.

[0050] The surface of the support may be subjected to surface treatment such as corona discharge treatment or glow discharge treatment to improve the adhesion between the support and the primer layer.

[0051] Next, the primer layer will be described.

[0052] The maximum peak height in the surface of the primer layer in one embodiment of the present invention is less than 0.5 μm. By making the maximum peak height in the surface of the primer layer less than 0.5 μm, image reproducibility and printing resistance can be improved, and uneven printing can be suppressed. The reason why image reproducibility and printing resistance are improved and uneven printing can be suppressed by smoothing the surface of the primer layer is unclear, but it is speculated that by arranging a thermosensitive layer on a smooth primer layer having a maximum peak height in the surface of the primer layer of less than 0.5 μm, the stress during printing is not easily concentrated on the convex portion of the thermosensitive layer surface, so that printing resistance is improved. In addition, it is speculated that by arranging a thermosensitive layer on such a smooth primer layer, the film position of the thermosensitive layer is not easily generated, so image reproducibility is improved, and uneven printing can be suppressed. The maximum peak height in the surface of the primer layer is preferably less than 0.4 μm, more preferably less than 0.3 μm.

[0053] use Figure 2 The maximum peak height on the surface of the primer layer in the present invention will be described. Figure 2The schematic cross-sectional view of an example of a known direct drawing type waterless planographic printing plate precursor for showing the past, has support 1, primer layer 2, heat-sensitive layer 3, silicone rubber layer 4 from the bottom.As mentioned above, when support 1 is an aluminum alloy plate, there is concavo-convex on its surface.As the method for forming primer layer 2 on support 1, generally use the method for coating primer layer forming composition, but if there is concavo-convex on the surface of support 1, apply high viscosity primer layer forming composition, then dry, solidify before leveling, thereby also form the concavo-convex of the concavo-convex of support surface on the surface of primer layer 2.In the present invention, the height of the top of the mountain from the reference height a0 of primer layer 2 (as follows, the height of the surface position of the primer layer under the situation that the primer layer is formed by assuming that the primer layer is completely leveled and formed with the primer layer composition) to the most convex portion is defined as the maximum peak height a3 in the surface of primer layer. Furthermore, the average thickness of the primer layer (described later) is represented by a1, the thickness of the thinnest portion of the primer layer is represented by a2, the average thickness of the heat-sensitive layer is represented by b1, and the thickness of the thinnest portion of the heat-sensitive layer is represented by b2. In a cross-sectional SEM image of the printing plate precursor, the average height of the support and primer layer is calculated by dividing the total area of ​​the support and primer layer portions in the cross-sectional SEM image by the observed width of the cross-sectional SEM image. The resulting average height is defined as the height from the bottom edge of the cross-sectional SEM image to determine the reference height a0 of the primer layer. Details are described below.

[0054] on the other hand, Figure 3 This is a schematic cross-sectional view of an example of a direct drawing type waterless planographic printing plate precursor of the present invention, which comprises, from the bottom, a support 1, a primer layer 2, a heat-sensitive layer 3, and a silicone rubber layer 4. By applying a low-viscosity primer layer-forming composition having excellent leveling properties, for example, on the support 1 having uneven surfaces, the primer layer-forming composition is leveled on the surface of the support 1 before drying and curing, thereby making the surface of the primer layer 2 smooth. Here, it is preferred that the difference between the base height a0 of the primer layer 2 and the surface of the primer layer 2 is small, and the difference between the base height a0 of the primer layer 2 and the surface of the primer layer 2 is small. Figure 3 By further providing the heat-sensitive layer 3 on the primer layer 2 having a smooth surface, the surface of the heat-sensitive layer 3 also becomes smooth.

[0055] The maximum peak height on the surface of the primer layer can be obtained by performing SEM observation on the cross section of the printing plate original. In more detail, after the printing plate original is embedded in a resin, a cross section is made by the BIB method. At this time, when the support has rolling grain, a cross section is made in a direction perpendicular to the rolling grain. The observation surface is subjected to conductive treatment (Pt coating) to prepare a sample for cross-sectional observation. The obtained sample for cross-sectional observation is observed using a scanning electron microscope under the following observation conditions: reflected electron image, acceleration voltage: 3.0 kV, magnification: 10 to 30,000 times (appropriately selected according to the thickness of the primer layer). Cross-sectional SEM observation is performed on 30 randomly selected locations in the width direction. In the cross-sectional SEM images of all 30 locations obtained, the peak height on the surface of the primer layer is obtained, and the portion with the highest peak height is set as the maximum peak height on the surface of the primer layer. The base height of the primer layer in each cross-sectional SEM image can be determined by dividing the total area of ​​the support portion and the primer layer portion of the cross-sectional SEM image by the observed width of the cross-sectional SEM image to calculate the average height of the total support and primer layer, and setting the resulting average height as the height from the bottom edge of the cross-sectional SEM image. In addition, the peak height of the surface of the primer layer in each cross-sectional SEM image can be determined by measuring the height from the base height of the primer layer determined by the above method to the peak of the most convex portion of the primer layer in the cross-sectional SEM image.

[0056] Examples of means for making the maximum peak height on the surface of the primer layer 0.5 μm or less include a method of coating the primer layer-forming composition on the support having a smooth surface, a method of reducing the viscosity of the primer layer-forming composition to improve leveling properties, a method of using a high-boiling-point solvent in the primer layer-forming composition to ensure leveling time, a method of ensuring leveling time by allowing sufficient time between coating the primer layer-forming composition and heating, a method of increasing the thickness of the primer layer, etc. These methods may also be combined.

[0057] As another indicator of the smoothness of the primer layer, in the present invention, a reference height of the primer layer is set in the cross section of the printing plate original, and the concavity and convexity of the primer layer relative to the reference height are focused on. In one embodiment of the present invention, within a range of 750 μm in width of the primer layer in the cross section of the printing plate original, the sum of the total area of ​​the portion of the primer layer that protrudes from the reference height of the primer layer (hereinafter sometimes abbreviated as "convex area") and the total area of ​​the portion of the primer layer that is recessed from the reference height of the primer layer (hereinafter sometimes abbreviated as "concave area") is 0 to 60 μm. 2 .

[0058] Here, the sum of the convex area and the concave area of ​​the primer layer can be obtained by SEM observation of a cross section of the printing plate precursor as described later. It should be noted that in the present invention, in order to fully suppress the measurement deviation of the convex area and the concave area of ​​the primer layer and appropriately evaluate the smoothness of the primer layer surface, the observation range is set to the range of 750 μm of the width of the primer layer.

[0059] By making the sum of the convex area and the concave area of ​​the primer layer 0 to 60 μm 2 , thereby improving image reproducibility and printing durability and suppressing uneven printing. The reason why the image reproducibility is improved and uneven printing is suppressed by smoothing the surface of the primer layer is presumably the same as the maximum peak height of the primer layer. The sum of the convex area and the concave area of ​​the primer layer is preferably 48 μm 2 Below, more preferably 36 μm 2 the following.

[0060] use Figure 4 The relationship between the reference height of the primer layer and the primer layer in the present invention will be described. Figure 4 The present invention is a schematic cross-sectional view showing an example of a conventionally known direct-drawing type waterless planographic printing plate precursor, which comprises, from the bottom, a support 1, a primer layer 2, a heat-sensitive layer 3, and a silicone rubber layer 4. As described above, when the support 1 is an aluminum alloy plate, there are irregularities on its surface. If a high-viscosity primer layer-forming composition is applied to such a support 1, irregularities originating from the irregularities on the support surface are also formed on the surface of the primer layer 2. In the present invention, relative to the base height a0 of the primer layer, the portion protruding toward the heat-sensitive layer 3 compared with the base height a0 of the primer layer is represented as a portion a4 protruding compared with the base height a0 of the primer layer, and the portion recessed toward the support 1 compared with the base height a0 of the primer layer is represented as a portion a5 recessed compared with the base height a0 of the primer layer.

[0061] On the other hand, Figure 3 In the schematic cross-sectional view showing an example of the direct drawing type waterless planographic printing plate precursor of the present invention, the surface of the primer layer 2 is smooth, and the reference height a0 of the primer layer 2 is consistent with the surface of the primer layer 2. That is, since there are no protruding parts or recessed parts compared to the reference height of the primer layer, Figure 3 The sum of the area of ​​the convex portion and the area of ​​the concave portion is 0.

[0062] The sum of the area of ​​the convex portion and the area of ​​the concave portion of the primer layer is set to 0 to 60 μm. 2Examples of the methods include coating the primer layer forming composition on a smooth support, reducing the viscosity of the primer layer forming composition to improve leveling properties, using a high-boiling-point solvent in the primer layer forming composition to ensure leveling time, ensuring leveling time by allowing sufficient time between coating the primer layer forming composition and heating, and increasing the thickness of the primer layer. These methods may also be combined.

[0063] In the range of 750 μm of the width of the primer layer in the cross section, the number of intersections of the base height of the primer layer and the line representing the interface between the primer layer and the thermosensitive layer (hereinafter sometimes abbreviated as "the number of intersections") is preferably 0 to 600. If the number of intersections is 600 or less, the protruding position of the primer layer, that is, the thin film position of the thermosensitive layer becomes less, so that the image reproducibility can be further improved and the printing unevenness can be further suppressed. The number of intersections is more preferably 450 or less, and further preferably 300 or less. It should be noted that in the present invention, in order to fully suppress the measurement deviation of the number of intersections of the primer layer and appropriately evaluate the smoothness of the primer layer surface, the observation range is set to the range of 750 μm of the width of the primer layer.

[0064] use Figure 5 The intersection of the reference height of the primer layer and the line representing the interface between the primer layer and the heat-sensitive layer in the present invention will be described. Figure 5 This is a schematic cross-sectional view of an example of a direct-drawing waterless planographic printing plate precursor, which comprises, from the bottom, a support 1, a primer layer 2, a heat-sensitive layer 3, and a silicone rubber layer 4. The point where the reference height a0 of the primer layer intersects the line representing the interface between the primer layer 2 and the heat-sensitive layer 3 is denoted as intersection a6 of the reference height of the primer layer and the line representing the interface between the primer layer and the heat-sensitive layer.

[0065] On the other hand, Figure 3 In the schematic cross-sectional view of an example of the direct-drawing waterless planographic printing plate precursor of the present invention, the reference height a0 of the primer layer 2 coincides with the line representing the interface between the primer layer and the heat-sensitive layer. In other words, the number of intersections between the reference height of the primer layer and the line representing the interface between the primer layer and the heat-sensitive layer is zero.

[0066] The sum of the convex and concave areas of the primer layer and the number of intersections can be determined by SEM observation of a cross section of the printing plate precursor. More specifically, similar to the case of determining the sum of the convex and concave areas of the support, 30 samples of the printing plate precursor of 10 mm x 10 mm in size were cut at different positions in the width direction, each of which was resin-embedded. A cross section perpendicular to the rolling grain of the aluminum substrate was prepared using the BIB method, and the observation surface was subjected to a conductive treatment (Pt coating) to prepare a sample for cross-sectional observation. The obtained sample for cross-sectional observation was observed using a scanning electron microscope under the following observation conditions: reflected electron imaging, accelerating voltage: 3.0 kV, and magnification: 5,000 times. In the obtained 30 cross-sectional SEM images, a line indicating the base height of the primer layer was drawn in a manner parallel to the line representing the interface between the silicone rubber layer and the embedding resin. In each cross-sectional SEM image, the total area of ​​the convex and concave portions was calculated for a width of 25 μm at the center of the primer layer in the width direction of the image, and the number of intersections between the base height of the primer layer and the line representing the interface between the primer layer and the heat-sensitive layer was counted. By summing the values ​​for all 30 cross-sectional SEM images, the total area of ​​the convex and concave portions and the number of intersections were determined.

[0067] As means for making the number of intersections 0 to 600, for example, methods cited as means for making the sum of the convex area and the concave area of ​​the above-mentioned support within the above-mentioned range, and methods cited as means for making the maximum peak height, the sum of the convex area and the concave area of ​​the primer layer within the above-mentioned range, etc.

[0068] The average thickness of the primer layer is preferably 2 to 500 μm. If the average thickness is 2 μm or more, the influence of the unevenness of the support surface can be suppressed, making the surface of the primer layer smoother. In addition, good concealment and scratch resistance can be obtained. The average thickness of the primer layer is more preferably 4 μm or more, and further preferably 6 μm or more. On the other hand, if the average thickness of the primer layer is 500 μm or less, dripping of the primer layer forming composition during coating can be suppressed. In addition, since the solvent evaporates efficiently from the primer layer forming composition after coating, the surface can be smoother. The average thickness of the primer layer is preferably 400 μm or less, and further preferably 300 μm or less. The average thickness of the primer layer can be measured by cross-sectional SEM observation. In more detail, the cross-sectional SEM observation is performed in the same manner as the determination of the maximum peak height in the surface of the primer layer, and the thickness of 20 randomly selected locations among the 30 cross-sectional SEM images obtained is measured, and the arithmetic mean value is calculated to obtain the average thickness.

[0069] The thickness of the thinnest part of the primer layer is preferably 1 μm or more. By making the thickness of the thinnest part of the primer layer 1 μm or more, in the method for manufacturing the lithographic printing plate described later, the heat generated by the irradiation of the laser can be suppressed from being conducted to the support, thereby making it possible to further improve the image reproducibility and suppress uneven printing. The thickness of the thinnest part of the primer layer is more preferably 2 μm or more, and further preferably 3 μm or more. The thickness of the thinnest part of the primer layer can be obtained by cross-sectional SEM observation. In more detail, cross-sectional SEM observation is performed in the same manner as the determination of the maximum peak height in the surface of the primer layer, and the thickness of the thinnest part of the primer layer in all 30 cross-sectional SEM images obtained by length measurement can be obtained.

[0070] As a means for making the thickness of the thinnest portion of the primer layer 1 μm or more, for example, a method of increasing the thickness of the primer layer can be mentioned.

[0071] In the present invention, the light transmittance of the primer layer is preferably 15% or less at all wavelengths of 400 to 650 nm. A light transmittance of 15% or less allows for mechanical plate inspection. The light transmittance of the primer layer is more preferably 10% or less, and even more preferably 5% or less.

[0072] The transmittance of primer layer can be measured using for example a visible spectrophotometer. When the support is transparent, it can be measured by transmission method. When the support is opaque, it can be measured by reflection method. As such a visible spectrophotometer, U-3210 automatic recording spectrophotometer made by Hitachi can be enumerated.

[0073] Next, the heat-sensitive layer in the printing plate precursor of the present invention will be described.

[0074] Examples of the heat-sensitive layer include heat-melting type, heat-expanding type, heat-destructible type, heat-separating type, and heat-curing type heat-sensitive layers that have been disclosed as heat-sensitive layers for direct-drawing waterless planographic printing plates.

[0075] [Thermo-meltable heat-sensitive layer]

[0076] The heat-soluble thermosensitive layer is a type of thermosensitive layer that forms a cross-linked structure by a cross-linking agent in the state of a printing plate original, and the heat generated by the laser irradiation reduces the adhesion between the thermosensitive layer and the silicone rubber layer. By the subsequent development treatment, the silicone rubber layer of the portion irradiated with the laser is removed. Most of the thermosensitive layer of the laser irradiated portion remains after development. As the heat-soluble thermosensitive layer, for example, a layer obtained by coating a composition containing a polymer having active hydrogen, a cross-linking agent and a photothermal conversion substance, a diluent thereof, a composition containing a polymer having active hydrogen, an organic coordination compound and a photothermal conversion substance, a diluent thereof, and (heating) drying can be cited. As the polymer having active hydrogen, a polymer having phenolic hydroxyl groups such as a homopolymer or copolymer of p-hydroxystyrene, a novolac resin, and a resol resin is preferred. Examples of the crosslinking agent include organic coordination compounds, polyfunctional isocyanates, polyfunctional blocked isocyanates, polyfunctional epoxy compounds, polyfunctional (meth)acrylate compounds, polyfunctional aldehydes, polyfunctional mercapto compounds, polyfunctional alkoxysilyl compounds, polyfunctional amine compounds, polyfunctional carboxylic acids, polyfunctional vinyl compounds, polyfunctional diazo compounds, and polyfunctional hydroxybenzoic acid compounds. Salts, polyfunctional azide compounds, hydrazines, etc. Examples of organic coordination compounds include acetylacetone coordination compounds and acetoacetate coordination compounds of Al(III), Fe(II), Fe(III), Ti(IV), and Zr(IV). Examples of photothermal conversion materials include dyes and pigments that absorb infrared or near-infrared rays. Specific examples of heat-soluble heat-sensitive layers include those described in Japanese Patent Application Publication No. 11-221977, Japanese Patent Application Publication No. 2004-334025, Japanese Patent Application Publication No. 2005-309126, and Japanese Patent Application Publication No. 2009-014946.

[0077] [Thermal expansion type thermal layer]

[0078] Specific examples of the heat-expandable thermosensitive layer include thermosensitive layers having bubbles described in Japanese Patent Application Laid-Open Nos. 2005-300586 and 2005-331924, and thermosensitive layers having liquid bubbles described in International Publication No. 2010 / 113989.

[0079] Highly sensitive printing plate precursors containing bubbles or vacuoles in their heat-sensitive layers can be developed simply by applying physical force after exposure. Consequently, during the printing plate manufacturing process, a phenomenon known as "blistering" occurs, where the silicone rubber layer in the exposed area rises. This blistering can hinder exposure and development, and is more likely to occur with higher sensitivity and higher exposure doses.

[0080] Specific examples of heat-expandable thermosensitive layers for suppressing such blistering include thermosensitive layers containing non-photosensitive particles as described in Japanese Patent Application Laid-Open Nos. 2012-93728, 2012-133321, 2012-133322, and International Publication No. 2012 / 043282; and thermosensitive layers containing at least a novolac resin, a polyurethane, and a photothermal conversion material and having a phase-separated structure comprising a phase containing at least a novolac resin and a phase containing a polyurethane as described in International Publication No. 2012 / 099003.

[0081] [Heat-destructible thermal layer]

[0082] A heat-destructible thermosensitive layer is one that is thermally destroyed by laser irradiation. Subsequent development removes the silicone rubber layer along with the destroyed thermosensitive layer, leaving the image line. Specific examples of heat-destructible thermosensitive layers include those described in Japanese Patent Application Publication Nos. 7-314934, 9-086065, and 9-131981, U.S. Patent Nos. 5,353,705 and 10,011,137.

[0083] [Heat-separation type thermal layer]

[0084] The so-called heat-separable thermosensitive layer is the second layer that forms a printed pattern in the following image forming system. The so-called image forming system is: an image forming system comprising: a first layer and a second layer attached to the first layer, wherein the first and second layers are irreversibly separated from each other in a pattern related to the image without substantially ablating the second layer by heating a printing member having different affinities for at least one printing liquid selected from ink and ink-repellent liquid; and an image forming system comprising: a first layer, a second layer attached to the underside of the first layer, and a third layer disposed under the second layer, wherein the first layer and at least one of the second and third layers are irreversibly separated from each other in a pattern related to the image without ablating the second layer by heating a printing member having different affinities for at least one printing liquid selected from ink and ink-repellent liquid. Specific examples of the heat-separable heat-sensitive layer include the heat-sensitive layer described in US Pat. No. 6,107,001.

[0085] [Thermosetting heat-sensitive layer]

[0086] A so-called thermosetting heat-sensitive layer is one that forms a crosslinked structure through heat-activated crosslinking agents generated by laser irradiation. The subsequent development process leaves the silicone rubber layer in the areas irradiated with the laser, while the unirradiated areas are removed. Even in the unirradiated areas, the heat-sensitive layer remains after development. Specific examples of heat-setting heat-sensitive layers include those described in Japanese Patent Application Publication Nos. 11-157236 and 11-240271.

[0087] Among these heat-sensitive layers, heat-soluble, heat-expandable, or heat-destructible heat-sensitive layers are preferred because they offer high sensitivity, superior image reproducibility, and can suppress printing unevenness. Among these, using a heat-destructible heat-sensitive layer as the heat-sensitive layer in the exposed area, which is removed during the platemaking process, is more preferred because it allows plate inspection without requiring dyeing of the image line area after development.

[0088] The average thickness of the heat-sensitive layer is preferably 0.5 to 2.0 μm. By setting the average thickness of the heat-sensitive layer to 0.5 μm or greater, heat generation efficiency can be improved, image reproducibility and sensitivity can be further enhanced, and printing unevenness can be further suppressed. On the other hand, by setting the average thickness of the heat-sensitive layer to 2.0 μm or less, solvent volatilization from the coating film becomes easier. Furthermore, in the case of a heat-destructible heat-sensitive layer, heat destruction to the lower portion of the heat-sensitive layer is facilitated, thereby further improving image reproducibility and plate inspection performance.

[0089] The thickness of the thinnest portion of the heat-sensitive layer is preferably 0.2 μm or greater. Setting the thickness of the thinnest portion of the heat-sensitive layer to 0.2 μm or greater improves heat generation efficiency, further enhances image reproducibility and sensitivity, and further reduces printing unevenness. The thickness of the thinnest portion of the heat-sensitive layer is preferably 0.3 μm or greater, and more preferably 0.4 μm or greater.

[0090] As an indicator of the smoothness of the heat-sensitive layer, in the present invention, a reference height of the heat-sensitive layer is set in the cross section of the printing plate precursor, and the projections and recesses of the heat-sensitive layer relative to the reference height are considered. Within a width of 750 μm of the heat-sensitive layer in the cross section of the printing plate precursor, the sum of the areas of the heat-sensitive layer that protrude relative to the reference height (hereinafter sometimes referred to as "projection area") and the areas of the heat-sensitive layer that are recessed relative to the reference height (hereinafter sometimes referred to as "recessed area") is preferably 0 to 30 μm. 2 By making the sum of the convex and concave areas of the heat-sensitive layer 30 μm 2 The total area of ​​the convex portion and the concave portion of the heat-sensitive layer is more preferably 24 μm. 2 Below, more preferably 18 μm 2Here, the sum of the convex and concave areas of the heat-sensitive layer can be determined by SEM observation of a cross-section of the printing plate precursor, as described below. It should be noted that in the present invention, in order to sufficiently suppress measurement variations in the convex and concave areas of the heat-sensitive layer and appropriately evaluate the smoothness of the heat-sensitive layer surface, the observation range is set to 750 μm across the width of the heat-sensitive layer.

[0091] use Figure 6 The relationship between the reference height of the heat-sensitive layer and the heat-sensitive layer in the present invention will be described. Figure 6 This is a schematic cross-sectional view of an example of a conventionally known direct-drawing waterless planographic printing plate precursor, comprising, from the bottom, a support 1, a primer layer 2, a heat-sensitive layer 3, and a silicone rubber layer 4. As a method for forming the heat-sensitive layer 3 on the primer layer 2, a method of applying a heat-sensitive layer-forming composition is generally used. However, if a heat-sensitive layer-forming composition, particularly a high-viscosity heat-sensitive layer-forming composition, is applied onto a primer layer 2 having surface irregularities, the surface of the heat-sensitive layer 3 is likely to be irregularities derived from the surface irregularities of the primer layer due to drying and curing before leveling. In the present invention, the height of the surface position of the heat-sensitive layer, assuming that the heat-sensitive layer-forming composition has completely leveled out to form the heat-sensitive layer, determined as follows, is defined as the reference height b0 of the heat-sensitive layer 3. The portion protruding toward the silicone rubber layer 4 relative to the reference height b0 of the heat-sensitive layer is designated as the portion protruding relative to the reference height b3 of the heat-sensitive layer. The portion recessed toward the primer layer 2 relative to the reference height b0 of the heat-sensitive layer is designated as the portion recessed relative to the reference height b4 of the heat-sensitive layer. In a cross-sectional SEM image of the printing plate precursor, the combined average height of the support, primer layer, and heat-sensitive layer is calculated by dividing the total area of ​​the support, primer layer, and heat-sensitive layer portions of the cross-sectional SEM image by the observed width of the cross-sectional SEM image. The resulting average height is then used as the height from the bottom edge of the cross-sectional SEM image to determine the reference height b0 of the heat-sensitive layer 3. Details are described below.

[0092] On the other hand, Figure 3 In the schematic cross-sectional view of an example of the direct-drawing waterless planographic printing plate precursor of the present invention, the surface of the primer layer 2 is smooth. By applying a low-viscosity thermosensitive layer-forming composition having excellent leveling properties, for example, on the smooth surface of the primer layer 2, the thermosensitive layer-forming composition is leveled on the surface of the primer layer 2 before drying and curing. As a result, the surface of the thermosensitive layer 3 is also smooth, and the reference height b0 of the thermosensitive layer 3 is consistent with the surface of the thermosensitive layer 3. That is, since there are no protruding portions or recessed portions compared to the reference height of the thermosensitive layer, the surface of the thermosensitive layer 3 is smooth. Figure 3 In the equation, the sum of the convex area and the concave area is 0.

[0093] The sum of the convex and concave areas of the thermal layer can be determined by SEM observation of a cross-section of the printing plate precursor. More specifically, similar to the method for determining the sum of the convex and concave areas of the support, 30 samples of the printing plate precursor, each 10 mm x 10 mm in size, were cut at different locations in the width direction. After each sample was embedded in resin, a cross-section perpendicular to the rolling grain of the aluminum substrate was prepared using the BIB method. The observation surface was then subjected to a conductive treatment (Pt coating) to prepare a sample for cross-sectional observation. The resulting sample for cross-sectional observation was observed using a scanning electron microscope under the following observation conditions: backscattered electron imaging, an accelerating voltage of 3.0 kV, and a magnification of 5,000 times. In the resulting 30 cross-sectional SEM images, a line indicating the base height of the thermal layer was drawn parallel to the line representing the interface between the silicone rubber layer and the embedding resin. In each cross-sectional SEM image, the total area of ​​the convex portion and the area of ​​the concave portion is calculated for the width of the thermosensitive layer located at the center of the image in the width direction of 25 μm. The values ​​of all 30 cross-sectional SEM images are summed up to obtain the total area of ​​the convex portion and the concave portion.

[0094] The sum of the area of ​​the convex portion and the area of ​​the concave portion of the heat-sensitive layer is set to 0 to 30 μm. 2 Examples of the methods include coating the heat-sensitive layer-forming composition on a smooth primer layer, reducing the viscosity of the heat-sensitive layer-forming composition to improve leveling properties, using a high-boiling-point solvent in the heat-sensitive layer-forming composition to ensure leveling time, ensuring leveling time by allowing sufficient time between coating the heat-sensitive layer-forming composition and heating, and increasing the thickness of the heat-sensitive layer. These methods may also be combined.

[0095] Examples of the silicone rubber layer include addition reaction type, condensation reaction type, and addition reaction-condensation reaction combined type silicone rubber layers that have been disclosed as ink repellent layers for waterless planographic printing plates.

[0096] Examples of the silicone rubber layer of the addition reaction type, condensation reaction type, or addition reaction-condensation reaction combined type include the layer exemplified as a layer containing a diorganosiloxane unit in Japanese Patent Application Laid-Open No. 2021-66175, the layer exemplified as a silicone rubber layer in International Publication No. 2019 / 203261, and the layer exemplified as a first organosilicon layer in International Publication No. 2019 / 203263.

[0097] The silicone rubber layer preferably contains a hard domain, which can further improve the printing resistance and scratch resistance. The presence or absence of a hard domain in the silicone rubber layer can be analyzed by the force array method of an atomic force microscope using a probe with a sharp tip for analysis at an extremely small load. By using a silicon or silicon nitride probe with a tip curvature radius of 5 to 20 nm and analyzing with a load of 1 to 20 nN, it is possible to measure the accurate elastic modulus of only the outermost surface of the silicone rubber layer, excluding the influence of the lower layer and the support. The force array method is a method of performing a two-dimensional scanning of the probe while repeating a series of actions such as moving the probe (cantilever) vertically and separating after pressing on the layer surface. At this time, since a force curve is obtained for each cycle, the mapping of mechanical properties such as the elastic modulus can be investigated by this analysis. In the present invention, when the elastic moduli of all measurement points within the obtained scanning range are mapped so that the whole is 100 area %, the case where the existence rate of island portions with a high elastic modulus of 100 MPa or more in a sea portion with a low elastic modulus of less than 10 MPa is less than 0.5 area % is judged to be free of hard structural domains, and the case where the existence rate of island portions with a high elastic modulus of 100 MPa or more is 0.5 area % or more is judged to be containing hard structural domains.

[0098] The hard domain contains a crosslinking agent reaction aggregate as its main component. Examples of crosslinking agents for addition reaction type silicone rubber layers include siloxane compounds having three or more SiH groups in the molecule. Examples of crosslinking agents for condensation reaction type silicone rubber layers include silane coupling agents. Examples of crosslinking agents for addition reaction and condensation reaction combined silicone rubber layers include siloxane compounds having three or more SiH groups in the molecule and silane coupling agents.

[0099] The average thickness of the silicone rubber layer is preferably 2 to 20 μm. By setting the average thickness of the silicone rubber layer to be 2 μm or more, the ink repellency, scratch resistance and printing resistance can be further improved. The average thickness of the silicone rubber layer is more preferably 2.5 μm or more, further preferably 3.0 μm or more, and further preferably 3.2 μm or more. On the other hand, by setting the average thickness of the silicone rubber layer to be 20 μm or less, the image reproducibility can be further improved and printing unevenness can be further suppressed. The average thickness of the silicone rubber layer is more preferably 15 μm or less, further preferably 10 μm or less, and further preferably 4.8 μm or less. The average thickness of the silicone rubber layer can be measured by cross-sectional SEM observation and can be obtained by the same method as the method for measuring the average thickness of the primer layer.

[0100] Furthermore, the silicone rubber layer may contain a liquid having a surface tension of 30 mN / m or less at 25°C to improve ink repellency. Examples of liquids having a surface tension of 30 mN / m or less at 25°C include those described in International Publication No. 2016 / 076286.

[0101] The printing plate precursor according to the present invention may further include a cover film and / or a backing paper on the silicone rubber layer to protect the surface of the silicone rubber layer.

[0102] The cover film preferably has a thickness of 100 μm or less, and specific examples thereof include films of polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, cellophane, and the like.

[0103] As the backing paper, the preferred basis weight is 30 to 90 g / m 2 As an example of the preferred backing paper, for example, information recording paper 40g / m 2 ( (Co., Ltd.), metal backing paper 30g / m 2 ( (Co., Ltd.), unbleached kraft paper 50g / m 2 ( (Co., Ltd.), NIP paper 52g / m 2 ( (Co., Ltd.), pure white roll paper 45g / m 2 (manufactured by Oji Paper Co., Ltd.), 73g / m 2 (manufactured by Oji Paper Co., Ltd.), etc.

[0104] Next, the method for producing the printing plate precursor according to the present invention will be described.

[0105] The method for producing a printing plate precursor according to the present invention preferably comprises at least the following steps: (1) a step of coating a primer layer-forming composition on a support and drying / curing the composition with or without heating to obtain a primer layer; and (2) a step of applying a heat-sensitive layer-forming composition on the primer layer obtained in step (1), and drying / curing the composition under heating or without heating to obtain a heat-sensitive layer; and (3) A step of applying a silicone rubber layer-forming composition on the heat-sensitive layer obtained in step (2), and drying and curing the composition with or without heating to obtain a silicone rubber layer.

[0106] Examples of methods for applying the primer layer-forming composition include methods using a slot die coater, a lip coater, a gravure coater, a direct roll coater, a reverse roll coater, a wire bar coater, etc. Among these, application using a slot die coater or a lip coater, which are closed-type coating methods, is preferred.

[0107] When heating is performed, examples of the heating device include a hot air dryer, an infrared dryer, etc. The heating temperature is preferably 50 to 200° C., and the heating time is preferably 30 seconds to 10 minutes.

[0108] Examples of the coating method for the heat-sensitive layer-forming composition include the methods exemplified as the coating method for the primer layer-forming composition. Coating using a slot die coater or a lip coater, which is a closed coating method, is preferred.

[0109] When heating is performed, preferred embodiments of the heating conditions are the same as those for the primer layer.

[0110] The silicone rubber layer-forming composition can be applied by any of the methods exemplified for the primer layer-forming composition. Application using a slot die coater or lip coater, which are closed-type coating methods, is preferred. During application, it is preferable to remove as much moisture as possible from the surface of the heat-sensitive layer in order to improve adhesion.

[0111] When heating is performed, preferred embodiments of the heating conditions are the same as those for the primer layer.

[0112] Next, a primer layer-forming composition that is preferably used in the method for producing a printing plate precursor according to the present invention will be described.

[0113] The primer layer-forming composition in the present invention preferably contains polyurethane, an active hydrogen group-containing aromatic compound, and a metal chelate compound.

[0114] Polyurethane is generally obtained by the reaction of a polyisocyanate with a polyol. Examples of polyisocyanates include p-phenylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dimethylbiphenyl diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Examples of polyols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, glycerol, and trimethylolpropane.

[0115] The polyurethane content is preferably 10 to 75% by mass of the total solid content of the primer layer forming composition. Here, the so-called total solid content of the primer layer forming composition refers to the components remaining after the primer layer forming composition is applied and dried, and the volatile components are removed. The definition of the total solid content in the other layer forming compositions is similar. By making the polyurethane content 10% or more by mass, the scratch resistance can be improved. On the other hand, by making the polyurethane content 75% or less by mass, the development tolerance can be widened.

[0116] Examples of the active hydrogen group-containing aromatic compound include hydroxyl group-containing aromatic compounds, amino group-containing aromatic compounds, carboxyl group-containing aromatic compounds, thiol group-containing aromatic compounds, etc. Among these, hydroxyl group-containing aromatic compounds are preferred.

[0117] Examples of the hydroxyl group-containing aromatic compound include phenolic hydroxyl group-containing compounds and aromatic epoxy resins.

[0118] Examples of the compound containing a phenolic hydroxyl group include hydroquinone, catechol, guaiacol, cresol, xylenol, naphthol, dihydroxyanthraquinone, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, bisphenol A, bisphenol S, novolac resins, resol phenolic resins, resorcinol benzaldehyde resins, pyrogallol acetone resins, polymers and copolymers of hydroxystyrene, rosin-modified phenolic resins, epoxy-modified phenolic resins, lignin-modified phenolic resins, aniline-modified phenolic resins, melamine-modified phenolic resins, and bisphenols.

[0119] Examples of the aromatic epoxy resin include bisphenol A glycidyl ester, other bisphenol A epoxy resins, bisphenol F diglycidyl ester, other bisphenol F epoxy resins, bisphenol AD ​​diglycidyl ester, other bisphenol AD ​​epoxy resins, terephthalic acid diglycidyl ester, glycidyl phthalimide, dibromophenyl glycidyl ester, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, those obtained by reacting aniline with epichlorohydrin, those obtained by epoxidizing a novolac-type resin by co-condensing phenol and aniline with formaldehyde, and those obtained by reacting toluene diisocyanate with glycidol.

[0120] In addition, the content of the aromatic compound containing an active hydrogen group is preferably 15 to 50% by mass of the total solid content of the primer layer forming composition. By making the content of the aromatic compound containing an active hydrogen group 15% or more by mass, it is possible to achieve good adhesion to the support and the heat-sensitive layer, and in addition, the resistance to solvents is also increased. Furthermore, the cross-linking reaction with the metal chelate described later is fully carried out, which can further improve image reproducibility and further suppress printing unevenness. On the other hand, by making the content of the aromatic compound containing an active hydrogen group 50% or less by mass, it is possible to suppress the migration of unreacted aromatic compounds containing active hydrogen groups into the heat-sensitive layer forming composition, further improve image reproducibility, and further suppress printing unevenness.

[0121] Examples of the metal chelate include organic complex salts in which an organic ligand having two or more ligands in the molecule and capable of forming one or more cyclic structures with the metal is coordinated to the metal.

[0122] Examples of the metal include Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ge, In, Sn, Zr, and Hf. Al and Zr are preferred in terms of low coloration, and Al is more preferred in terms of reactivity.

[0123] Examples of organic ligands containing two or more ligands in the molecule and capable of forming one or more cyclic structures with the metal include β-diketones, ketoesters, diesters, hydroxycarboxylic acids or their esters and salts, ketoalcohols, aminoalcohols, and enolic active hydrogen compounds. In terms of shelf life, β-diketones and ketoesters are preferred, while in terms of reactivity, ketoesters are more preferred.

[0124] Specific examples of β-diketones and ketoesters include the following.

[0125] (1) β-diketones: 2,4-pentanedione, 2,4-heptanedione, trifluoroacetylacetone, hexafluoroacetylacetone, dibenzoylmethane, benzoyl acetone, benzoyltrifluoroacetone, etc.

[0126] (2) Ketone esters: methyl acetoacetate, ethyl acetoacetate, butyl acetoacetate, octyl acetoacetate, etc.

[0127] The metal chelate used in the present invention is preferably an aluminum chelate formed by coordinating two or more ketoesters with aluminum. The coordination of two or more ketoesters can suppress crosslinking reactions in the primer layer-forming composition, allowing the viscosity of the primer layer-forming composition to fall within the preferred range described below, thereby smoothing the surface of the primer layer. Furthermore, the shelf life of the primer layer-forming composition is significantly improved. Furthermore, since ligands are readily exchanged with active hydrogen-containing compounds during heating, resulting in a crosslinking reaction, the aluminum chelate exhibits excellent curability and suppresses sublimation and evaporation of the aluminum chelate itself.

[0128] The content of the metal chelate is preferably 1 to 30% by mass of the total solid content of the primer layer-forming composition. By setting the metal chelate content to 1% by mass or more, good adhesion to the support and the heat-sensitive layer is achieved, and resistance to solvents is also improved. Furthermore, sufficient cross-linking reaction with the above-mentioned active hydrogen group-containing aromatic compound can further improve image reproducibility and further suppress printing unevenness. The content of the metal chelate is more preferably 2% by mass or more. On the other hand, by setting the metal chelate content to 30% by mass or less, migration of unreacted metal chelate into the heat-sensitive layer-forming composition can be suppressed. The content of the metal chelate is more preferably 20% by mass or less.

[0129] It is preferred that the primer layer forming composition of the present invention contain a pigment. By containing the pigment, the transmittance of the primer layer can be made less than 15% for all wavelengths of 400 to 650 nm. Thus, the plate inspection property is improved by mechanical reading. As the pigment, inorganic white pigments such as titanium oxide, zinc oxide, and lithopone, inorganic yellow pigments such as chrome yellow, cadmium yellow, iron oxide yellow, ochre, and titanium yellow, and organic yellow pigments are preferred. As the organic yellow pigment, acetoacetanilide ( ) series monoazo pigments, acetoacetanilide series disazo pigments, condensed azo pigments, benzimidazolone series monoazo pigments and other azo pigments, isoindolinone series pigments, isodihydroindole series pigments, threonine series pigments, purple ring ketone series pigments, metal coordination compound pigments, anthraquinone series pigments, acylamino yellow series pigments, quinophthalone series pigments, flavanthreone series pigments and other polycyclic pigments. Among these pigments, titanium oxide is particularly preferred from the perspective of hiding power and tinting power. The surface of titanium oxide can be treated with hydrated aluminum oxide, silicon dioxide, hydrated titanium dioxide, hydrated zirconium oxide and the like for the purpose of improving dispersibility and weather resistance. The surface of titanium oxide subjected to these surface treatments can be further treated with a pigment dispersant such as a titanate series coupling agent. By such treatment, the filler effect is further suppressed, the thickening of the composition for forming the primer layer can be further suppressed and the viscosity can be maintained low, so that the surface of the primer layer can be made smoother. In addition, since the dispersibility of titanium oxide is improved, the content of titanium oxide particles can be increased. Furthermore, the dispersion stability of the titanium oxide particles in the primer layer-forming composition becomes good.

[0130] The titanium oxide particle size is preferably a primary particle size of 0.2 to 0.4 μm. A primary particle size of 0.2 μm or greater improves concealment. On the other hand, a primary particle size of 0.4 μm or less prevents spontaneous sedimentation, resulting in a dispersed and stable primer layer-forming composition solution and a glossy, high-quality coating film.

[0131] The pigment content is preferably 2 to 30% by volume of the total solid content of the primer layer-forming composition. By setting the pigment content to 2% by volume or more, good concealing performance is achieved. On the other hand, by setting the pigment content to 30% by volume or less, good coating performance can be achieved, further improving scratch resistance, print durability, and image reproducibility.

[0132] The primer layer-forming composition of the present invention preferably contains alkyl ethers (e.g., ethyl cellulose, methyl cellulose, etc.), fluorine-based surfactants, silicone-based surfactants, nonionic surfactants, etc. for the purpose of further improving the leveling properties and making the surface of the primer layer smoother.

[0133] The primer layer-forming composition preferably contains a solvent. By containing a solvent, the viscosity of the primer layer-forming composition can be significantly reduced, thereby improving leveling properties and making the surface of the primer layer smoother.

[0134] The solvent used in the primer layer-forming composition preferably has the property of dissolving polyurethane, aromatic compounds containing active hydrogen groups, metal chelates, and other additives well. In addition, when adding a pigment, it is preferred to select a solvent that wets the pigment surface well and obtains good pigment dispersibility. It may also contain two or more solvents.

[0135] The viscosity of the primer layer-forming composition is preferably 3 to 100 mPa at a liquid temperature of 25°C. s. The viscosity at a liquid temperature of 25°C is an indicator of the state of the primer layer forming composition when the primer layer is formed. By setting the viscosity of the primer layer forming composition to 3 mPa s or more, thereby suppressing dripping and bead breakage of the primer layer forming composition during coating, making the surface of the primer layer smoother and reducing the maximum peak height, the sum of the convex area and the concave area on the surface of the primer layer. The viscosity of the primer layer forming composition is more preferably 5mPa On the other hand, by making the viscosity of the primer layer forming composition 100mPa s or less, so that it is easy to level on the support surface, the surface of the primer layer can be smoothed and the maximum peak height, the sum of the convex area and the concave area on the surface of the primer layer can be made smaller. The viscosity of the primer layer forming composition is more preferably 50mPa s or less.

[0136] The viscosity of the primer layer-forming composition at a liquid temperature of 25° C. can be measured using a rotational viscometer.

[0137] The viscosity of the primer layer-forming composition at a liquid temperature of 25° C. can be adjusted to fall within the above-mentioned range by, for example, adjusting the solid content concentration of the primer layer-forming composition.

[0138] From the perspective of making the viscosity of the primer layer forming composition at a liquid temperature of 25°C within the above range, the solid content concentration of the primer layer forming composition is preferably 1 to 5% by mass. By making the solid content concentration 1% by mass or more, the surface can be smoothed and the maximum peak height, the sum of the convex area and the concave area on the surface of the primer layer can be made smaller. The solid content concentration of the primer layer forming composition is more preferably 2% by mass or more. On the other hand, by making the solid content concentration 5% by mass or less, the surface of the primer layer can be smoothed and the sum of the maximum peak height, the convex area and the concave area on the surface of the primer layer can be made smaller. The solid content concentration of the primer layer forming composition is more preferably 4% by mass or less.

[0139] The primer layer-forming composition can be obtained, for example, by adding a titanium oxide dispersion into a container and starting stirring, then adding the epoxy resin and polyurethane solution in small portions to prepare a high-concentration dispersion, then adding a solvent, a crosslinking agent, and a leveling agent in sequence, and stirring until the components become uniform.

[0140] The titanium oxide dispersion can be obtained, for example, by adding titanium oxide and, if necessary, a titanate coupling agent to a solvent and dispersing the mixture using a disperser such as a paint shaker, a ball mill, or a bead mill.

[0141] Examples of the heat-sensitive layer-forming composition include compositions described in Japanese Patent Application Laid-Open No. 2004-334025 and US Pat. No. 10,011,137.

[0142] Examples of the silicone rubber layer-forming composition include the composition exemplified as a layer-forming composition containing a diorganosiloxane unit in Japanese Patent Application Laid-Open No. 2021-66175, the composition exemplified as a silicone rubber layer-forming composition in International Publication No. 2019 / 203261, and the composition exemplified as a first organosilicon layer-forming composition in International Publication No. 2019 / 203263.

[0143] When forming a silicone rubber layer containing hard domains, the silicone rubber layer-forming composition preferably contains the above-mentioned crosslinking agent. During drying and curing of the silicone rubber layer-forming composition, hard domains mainly composed of reaction aggregates of the crosslinking agent can be easily formed.

[0144] Examples of siloxane compounds having three or more SiH groups in the molecule include organohydrogenpolysiloxanes, organohydrogensiloxane / diorganosiloxane copolymers, and compounds having three or more diorganohydrogensiloxy groups in the molecule. Two or more of these may be present. Among these, organohydrogenpolysiloxanes or organohydrogensiloxane / diorganosiloxane copolymers are preferred.

[0145] The molecular structures of organohydrogenpolysiloxanes and organohydrogensiloxane / diorganosiloxane copolymers can be linear, cyclic, branched, or network structures. Furthermore, the organic groups bonded to the silicon atoms may be the same or different, and are preferably monovalent organic groups that do not contain aliphatic unsaturated bonds. Examples of monovalent organic groups that do not contain aliphatic unsaturated bonds include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl.

[0146] In the case of a silicone rubber layer-forming composition containing a siloxane compound having three or more SiH groups in the molecule, the H group concentration derived from the SiH group is preferably 0.050 to 0.150 mass % in the total solid content. By making the H group concentration derived from the SiH group 0.050 mass % or more, it is easy to generate a hard domain with a reaction aggregate as the main component, thereby making it possible to further improve printing resistance and scratch resistance. The H group concentration derived from the SiH group is more preferably 0.070 mass % or more. On the other hand, by making the H group concentration derived from the SiH group 0.150 mass % or less, it is possible to suppress the reduction of image reproducibility and ink repellency. The H group concentration derived from the SiH group is more preferably 0.130 mass % or less.

[0147] Examples of the silane coupling agent include methyltriacetoxysilane, ethyltriacetoxysilane, phenyltriacetoxysilane, toluoyltriacetoxysilane, xylyltriacetoxysilane, methyltris(methylethylketoximino)silane, ethyltris(methylethylketoximino)silane, phenyltris(methylethylketoximino)silane, toluoyltris(methylethylketoximino)silane, xylyltris(methylethylketoximino)silane, vinyltriacetoxysilane, allyltriacetoxysilane, 3-acryloxypropyltriacetoxysilane, 3-methacryloxypropyltriacetoxysilane, vinyltris(methylethylketoximino)silane, allyltris(methylethylketoximino)silane, 3-acryloxypropyltris(methylethylketoximino)silane, and 3-methacryloxypropyltris(methylethylketoximino)silane. Two or more of these may be contained. Among them, vinyltriacetoxysilane or vinyltri(methylethylketoxime)silane is preferred.

[0148] When a silane coupling agent is contained in the composition for forming the silicone rubber layer, its content is preferably 8 to 38% by mass based on the total solid content. By setting the content of the silane coupling agent to 8% by mass or more, it is easy to generate hard domains, thereby further improving print resistance and scratch resistance. The content of the silane coupling agent is more preferably 15% by mass or more. On the other hand, by setting the content of the silane coupling agent to 38% by mass or less, it is possible to suppress the reduction of ink repellency. The content of the silane coupling agent is more preferably 30% by mass or less.

[0149] The method for producing a printing plate from a printing plate precursor is described below. The method for producing a printing plate of the present invention preferably comprises an exposure step of irradiating the printing plate precursor with laser light to form a latent image, and a development step of removing the silicone rubber layer corresponding to the line portion of the latent image.

[0150] First, the exposure step will be described. When a cover film or a backing paper is provided on the silicone rubber layer of the printing plate precursor, it is preferable to remove them in advance.

[0151] As a method for exposing the printing plate precursor, there is a method (CTP) in which an image is directly written on the printing plate precursor using near-infrared laser light (wavelength: 800 to 1,500 nm) according to digital data without using an original film.

[0152] In the formation of the latent image in the exposure process, it is preferred to use an AM screen or an AM / FM hybrid screen with an accuracy equivalent to 180 to 650 lines of an AM screen. If the accuracy is equivalent to or higher than 180 lines of an AM screen, moire, line breakage, graininess, etc. on the printed matter can be suppressed. On the other hand, if the accuracy is less than 650 lines of an AM screen, image reproducibility can be further improved and printing unevenness can be further suppressed. Examples of commercially available AM / FM hybrid screens include Fairdot2-350 and -650 (both manufactured by SCREEN Corporation). System), Staccato-10, -20, -25, -35, -36 (all Contract company system), Sublima-190, -210, -240, -280, -300, -340, -360 (all (Co., Ltd.) etc.

[0153] Next, the development step will be described.

[0154] The exposed printing plate precursor is rubbed in the presence or absence of a liquid, thereby removing the silicone rubber layer from either the exposed or unexposed areas. If the heat-sensitive layer provided on the printing plate precursor is of any of the aforementioned heat-soluble, heat-expandable, heat-destructible, and heat-detachable types, the silicone rubber layer from the exposed areas is removed. On the other hand, if the heat-sensitive layer is of a heat-curable type, the silicone rubber layer from the unexposed areas is removed. Examples of rubbing treatments include: (i) rubbing the plate surface with a developing pad, a brush, a dry cotton pad, or the like in the absence of a liquid; (ii) wiping the plate surface with a non-woven fabric, absorbent cotton, cloth, sponge, or the like impregnated with water or water containing a surfactant; (iii) rubbing the plate surface with a rotating brush while contacting the plate surface with water or water containing a surfactant; and (iv) spraying high-pressure water, warm water, or steam onto the plate surface. The surfactant is preferably one having a pH of 5 to 8 when prepared as an aqueous solution, and the surfactant content is preferably 10% by mass or less of the aqueous solution. Such an aqueous solution is highly safe and is also preferable in terms of economic efficiency such as disposal costs.

[0155] Before development, a pretreatment may be performed by immersing the plate in a pretreatment solution for a predetermined period of time. Examples of pretreatment solutions include water, water containing a polar solvent such as an alcohol, ketone, ester, or carboxylic acid, a solvent composed of at least one of aliphatic hydrocarbons and aromatic hydrocarbons containing a polar solvent, or a polar solvent. Pretreatment solutions containing glycol compounds or glycol ether compounds as their primary components are preferred. Amine compounds or the aforementioned surfactants may also be added to the pretreatment solution.

[0156] Examples of the pretreatment liquid include those described in Japanese Patent Application Laid-Open No. 63-179361, Japanese Patent Application Laid-Open No. 4-163557, Japanese Patent Application Laid-Open No. 4-343360, Japanese Patent Application Laid-Open No. 9-34132, and International Publication No. 1997 / 017634. ​​Specific examples of the pretreatment liquid include PP-1, PP-3, PP-F, PP-FII, PTS-1, PH-7N, CP-1, NP-1, DP-1, CP-Y, CP-X, and PX (all (Co., Ltd.) etc.

[0157] Furthermore, to improve the visibility of the image line and the measurement accuracy of the dots, the ink receiving layer of the image line can be dyed simultaneously with the development process by adding a dye such as crystal violet, Victoria Blue, or Astrazone Red to the water used for development or water containing a surfactant. Furthermore, the ink receiving layer of the image line can be dyed after development using a liquid containing the aforementioned dye.

[0158] Part or all of the above-mentioned development process can also be automatically performed using an automatic developer. Examples of automatic developers include those consisting solely of a development unit, those sequentially provided with a pre-processing unit and a development unit, those sequentially provided with a pre-processing unit, a development unit, and a post-processing unit, and those sequentially provided with a pre-processing unit, a development unit, a post-processing unit, and a washing unit. Specific examples of such automatic developers include the TWL-650 series, TWL-860 series, and TWL-1160 series (all manufactured by Toray Industries, Inc.), as well as those disclosed in Japanese Patent Application Publication Nos. 4-2265, 5-2272, and 5-6000. These can be used alone or in combination.

[0159] When the obtained planographic printing plates are stored in a stack, it is preferred to place a mount paper between the plates for the purpose of protecting the plate surface.

[0160] Next, a method for producing a printed material will be described.

[0161] The method for producing a printed article preferably uses the above-mentioned printing plate, ink, and a print medium. Specifically, the method preferably includes the steps of adhering ink to the surface of the ink adhering portion of the printing plate and transferring the ink adhering to the surface of the ink adhering portion to the print medium directly or via a rubber blanket.

[0162] As printing presses, known direct-brush printing presses and offset printing presses can be used. Offset printing presses are preferred because they minimize damage to the waterless printing plate during printing, allowing for a large volume of printed material. As offset printing presses, those equipped with cooling mechanisms for the oscillating roller and / or plate cylinder are preferred for improved resistance to base staining.

[0163] As ink, known oxidative polymerization inks and active energy ray-curable inks can be used. Active energy ray-curable inks are preferred because they dry quickly, allowing for immediate transfer to the next process after printing. Inks can be either oil-soluble or water-soluble, but water-soluble inks are preferred to reduce the burden on workers and the environment. Water-soluble active energy ray-curable inks are more preferred.

[0164] Examples of water-soluble active energy ray-curable inks preferably used in the present invention include known water-soluble active energy ray-curable inks that can be cleaned with water or an aqueous cleaning solution and are disclosed in, for example, Japanese Patent Application Publication No. 2017-52817, International Publication No. 2017 / 047817, and International Publication No. 2017 / 090663.

[0165] Examples of active energy rays include visible light, ultraviolet rays (UV), electron beams (EB), X-rays, and particle beams. Among these, ultraviolet rays and electron beams are preferred from the perspective of ease of handling of the radiation source.

[0166] When the ink is cured by ultraviolet rays, it is preferable to use an ultraviolet irradiation device such as a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or an LED. For example, when a metal halide lamp is used, a UV irradiation device with a power of 80 to 150 W / cm 2 From the perspective of productivity, curing is preferably performed while transporting the printed material on a conveyor at a speed of 50 to 150 m / min using a lamp with an illumination of 100 to 200 nm. In particular, when using a print medium made of plastic film or metal as the print medium, the print medium tends to expand and contract due to the heat generated by the active energy rays. Therefore, electron beams or ultraviolet irradiation devices using LEDs (LED-UV) are preferably used, as they generate less heat.

[0167] When curing is performed by electron beam, it is preferable to use an electron beam irradiation device having energy rays of 100 to 500 eV.

[0168] Examples of printed media include high-quality paper, art paper, coated paper, cast-coated paper, synthetic paper, and newspaper paper; metals such as aluminum, aluminum alloys, iron, steel, zinc, and copper; plastic films such as polyethylene terephthalate, polyethylene, polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, and polyvinyl acetal; or composites of these papers, metals, and plastic films (paper or plastic film deposited or laminated with metal, paper or metal laminated with plastic film, metal or plastic film laminated with paper, etc.).

[0169] Among them, the method for manufacturing printed materials involved in the present invention is suitable for printing on non-ink-absorbing printing media such as synthetic paper, metal, plastic film, paper or plastic film with metal vapor deposited or laminated, paper or metal laminated with plastic film, etc., whose printed surface is composed of metal or plastic film.

[0170] Among the above, in terms of improving adhesion, the printed surface of the printed medium such as synthetic paper, plastic film, paper laminated with plastic film or metal composed of plastic film can be subjected to surface treatment such as primer resin coating, corona discharge treatment, glow discharge treatment, etc.

[0171] As the shape of the printed medium, a sheet-shaped ( ), or in a roll. When printing on thin films for flexible packaging, it is preferred to use a roll film and perform printing using a roll-to-roll method. Furthermore, by using a seamless printing plate with a cylindrical or columnar support and a roll of long printed media for roll-to-roll printing, high-definition printed materials with seamless patterns can be mass-produced.

[0172] Example

[0173] The present invention will be described in further detail below with reference to Examples. Measurements and evaluations in each of the Examples and Comparative Examples were performed by the following methods.

[0174] (1) Arithmetic mean roughness of the support surface (Ra)

[0175] The support used in each example and comparative example was measured for its surface arithmetic mean roughness (Ra) by a method according to Japanese Industrial Standards (JIS B0601: 2001). Specifically, a surface roughness measuring instrument was used: "(Registered trademark) 1400G (manufactured by Tokyo Seimitsu Co., Ltd.) was used to measure Ra in the direction perpendicular to the rolling grain.

[0176] (2) The sum of the convex and concave areas of the support

[0177] The 1,170 mm x 854 mm printing plate precursors obtained in each of the Examples and Comparative Examples were cut into 30 samples measuring 10 mm x 10 mm, with each sample approximately centered at 30 locations, namely, 100, 133, 167, 200, 234, 267, 301, 334, 368, 401, 434, 468, 501, 535, 568, 602, 635, 669, 702, 736, 769, 802, 836, 869, 903, 936, 970, 1003, 1037, and 1070 mm from the widthwise ends of the printing plate precursor. Each of the 30 cut samples was resin-embedded, and a cross-section perpendicular to the milling grain of the aluminum substrate was prepared using the BIB method. The observation surface was then subjected to a conductive treatment (Pt coating) to prepare samples for cross-sectional observation. The obtained sample for cross-sectional observation was subjected to cross-sectional SEM observation under the following conditions.

[0178] [Cross-sectional SEM observation]

[0179] Field emission scanning electron microscope: SU8020 (Hitachi Co., Ltd.) system)

[0180] Observation conditions: reflected electron image

[0181] Accelerating voltage: 3.0 kV

[0182] Magnification: 5,000x.

[0183] In the obtained 30 cross-sectional SEM images, a line c0 of the reference height of the support was drawn in a manner parallel to the line representing the interface between the silicone rubber layer and the embedding resin. The average height of the support was calculated by dividing the area of ​​the support portion by the observed width of the cross-sectional SEM image in each cross-sectional SEM image. The average height of the support obtained was set as the reference height of the support from the bottom edge of the cross-sectional SEM image. In each cross-sectional SEM image, the width 25 μm of the support located in the center of the width direction of the image was calculated, and the total area of ​​the convex portion and the concave portion of the support was calculated. The total values ​​of the total area of ​​the convex portion and the concave portion of the 30 cross-sectional SEM images were all added up to obtain the sum of the convex portion area and the concave portion area (total surface concave-convex area).

[0184] (3) Viscosity of the primer layer-forming composition

[0185] The viscosity of the primer layer-forming composition obtained in each Example and Comparative Example was measured using a method in accordance with Japanese Industrial Standards (JIS Z 8803:2011). Specifically, the composition was allowed to stand for 24 hours in a 25°C constant temperature chamber equipped with a digital viscometer, DVNext (manufactured by Eiko Seiki Co., Ltd.), to remove air from the composition and adjust the liquid temperature to 25°C. The viscosity of the primer layer-forming composition after standing for 24 hours was measured three times using the digital viscometer, and the arithmetic average of the measurements was defined as the viscosity of the primer layer-forming composition.

[0186] (4) The sum of the convex and concave areas of the primer layer and the number of intersections

[0187] In the cross-sectional SEM image of the printing plate original obtained in the above-mentioned item (2), a line a0 of the reference height of the primer layer is drawn in a manner parallel to the line representing the interface between the silicone rubber layer and the embedding resin. The total average height of the support and the primer layer is calculated by dividing the total area of ​​the support portion and the primer layer portion in each cross-sectional SEM image by the observed width of the cross-sectional SEM image. The obtained average height of the total of the support and the primer layer is set as the reference height of the primer layer from the bottom edge of the cross-sectional SEM image. In each cross-sectional SEM image, the total area of ​​the convex part and the concave part of the primer layer is calculated with respect to the width 25 μm of the primer layer located in the center of the width direction of the image, and the total value of the total area of ​​the convex part and the concave part of the 30 cross-sectional SEM images is summed up to obtain the sum of the convex part area and the concave part area (the sum of the surface convex and concave areas).

[0188] In each cross-sectional SEM image, the number of intersections between the reference height of the primer layer and the line indicating the interface between the primer layer and the heat-sensitive layer was counted, and the number of intersections in all 30 cross-sectional SEM images was totaled to determine the number of intersections.

[0189] (5) Average thickness, maximum peak height, and thinnest thickness of the primer layer

[0190] The printing plate precursors obtained in each of the Examples and Comparative Examples were resin-embedded. A cross-section perpendicular to the rolling grain of the aluminum substrate was then prepared using the BIB method. The observation surface was then subjected to a conductive treatment (Pt coating) to prepare samples for cross-sectional observation. Cross-sectional SEM observations were performed at 30 randomly selected locations across the width of the resulting cross-sectional samples under the following conditions.

[0191] [Cross-sectional SEM observation]

[0192] Field emission scanning electron microscope: SU8020 ((Co., Ltd.) system)

[0193] Observation conditions: reflected electron image

[0194] Accelerating voltage: 3.0 kV

[0195] Magnification: 100x to 30,000x (select appropriately according to the thickness of the primer layer).

[0196] The primer layer thickness was measured at 20 randomly selected locations among the obtained 30 cross-sectional SEM images, and the arithmetic mean value thereof was defined as the average thickness of the primer layer.

[0197] The thickness of the thinnest portion of the primer layer in all 30 cross-sectional SEM images was measured, and this value was defined as the thinnest portion thickness of the primer layer.

[0198] In all 30 cross-sectional SEM images obtained, the combined area of ​​the support and primer layer portions of the cross-sectional SEM images was divided by the observed width of the cross-sectional SEM images to calculate the average height of the combined support and primer layer. The resulting average height was set as the height from the bottom edge of the cross-sectional SEM images to determine the reference height of the primer layer. The peak height on the surface of the primer layer was determined by measuring the height from the reference height of the primer layer to the height of the peak of the most convex portion of the primer layer in the cross-sectional SEM images. The portion with the highest peak height was defined as the maximum peak height on the surface of the primer layer.

[0199] (6) The sum of the convex and concave areas of the thermal layer

[0200] In the cross-sectional SEM image of the printing plate precursor obtained in the above-mentioned item (2), a line b0 of the reference height of the thermosensitive layer is drawn in parallel with the line representing the interface between the silicone rubber layer and the embedding resin. The reference height of the thermosensitive layer in each cross-sectional SEM image is calculated by dividing the total area of ​​the support portion, the primer layer portion, and the thermosensitive layer portion of the cross-sectional SEM image by the observed width of the cross-sectional SEM image to calculate the total average height of the support, the primer layer, and the thermosensitive layer. The obtained total average height of the support, the primer layer, and the thermosensitive layer is set as the reference height of the thermosensitive layer from the bottom edge of the cross-sectional SEM image. In each cross-sectional SEM image, the total area of ​​the convex portion and the total area of ​​the concave portion of the thermosensitive layer is calculated with respect to the width of 25 μm located in the center of the width direction of the image, and the total values ​​of the total area of ​​the convex portion and the concave portion of the 30 cross-sectional SEM images are summed up to obtain the total area of ​​the convex portion and the concave portion (total surface convex and concave area).

[0201] (7) Average thickness and thinnest thickness of the thermal layer

[0202] The thickness of the heat-sensitive layer was measured at 20 randomly selected locations among the 30 cross-sectional SEM images obtained in the above-mentioned section (5), and the arithmetic average thereof was set as the average thickness of the heat-sensitive layer.

[0203] The thickness of the thinnest portion of the heat-sensitive layer in all 30 cross-sectional SEM images was measured, and this value was defined as the thinnest portion thickness of the heat-sensitive layer.

[0204] (8) Average thickness of silicone rubber layer

[0205] The thickness of the silicone rubber layer was measured at 20 randomly selected locations among the 30 cross-sectional SEM images obtained in the above-mentioned section (5), and the arithmetic mean value thereof was defined as the average thickness of the silicone rubber layer.

[0206] (9) Presence of hard domains in the silicone rubber layer

[0207] The presence or absence of hard domains in the silicone rubber layer of the printing plate precursors obtained by the methods described in the respective Examples and Comparative Examples was evaluated by the following analytical method.

[0208] Analytical device: Scanning probe microscope (SPM): NanoScope Vdimension Icon (manufactured by Bruker)

[0209] Probe: Silicon cantilever (spring constant = 6 N / m)

[0210] Front curvature radius: 8nm

[0211] Load: 5~20nN

[0212] Scanning mode: force array (contact mode)

[0213] Scanning range: Any 25μm of the silicone rubber layer 2 (Length: 5 μm × Width: 5 μm)

[0214] Measurement points within the scanning range: 4,096 points (64 vertical points x 64 horizontal points)

[0215] Measurement environment: room temperature, in air.

[0216] When the elastic modulus of all measurement points (4,096 points) within the obtained scanning range is mapped so that the whole is 100 area %, the case where the existence rate of the island part with a high elastic modulus of 100 MPa or more in the sea part with a low elastic modulus of less than 10 MPa is less than 0.5 area % is judged to contain no hard structural domain, and the case where the existence rate of the island part with a high elastic modulus of 100 MPa or more is 0.5 area % or more is judged to contain a hard structural domain.

[0217] (10) Image reproducibility

[0218] The printing plate precursors of 1,170 mm × 854 mm size obtained in each example and comparative example were installed in a laser exposure machine: PlateRite 8900N-E ( (co., Ltd.), exposure dose: 150mJ / cm 2 The following halftone dot image (AM halftone 175 lines (resolution: 2400 dpi)) was exposed under the following conditions in an area of ​​1070 mm×840 mm and developed under the following development conditions to obtain a printing plate.

[0219] <Dot Image>

[0220] Image pattern: All 25 flat screen patterns with dot area rates of 0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100%

[0221] The exposure area of ​​each flat screen is: 1,070mm in width, 120mm in length only at 0% flat screen, and 30mm in length at 0.5-100% flat screen.

[0222] <Development Conditions>

[0223] (Examples 1-12, 14-24 and Comparative Examples 1-9)

[0224] Automatic developing machine: TWL-1160FII( (Manufactured by Co., Ltd.)

[0225] Pretreatment liquid: CP-Y( (Co., Ltd., liquid temperature: 45°C)

[0226] Developer: tap water (liquid temperature: 30°C)

[0227] Post-treatment liquid: PA-1 (liquid temperature: 30°C)

[0228] Washing: tap water (liquid temperature: 30℃)

[0229] Development speed: 60cm / min

[0230] (Example 13, Example 25, Example 26, Example 27 and Comparative Example 10)

[0231] Automatic developing machine: TWL-1160FII( (Manufactured by Co., Ltd.)

[0232] Pretreatment liquid: None

[0233] Developer: tap water (liquid temperature: 30°C)

[0234] Post-treatment fluid: None

[0235] Washing: tap water (liquid temperature: 30℃)

[0236] Development speed: 60 cm / min.

[0237] The halftone dot image portion of the obtained printing plate was observed using a 25x magnifying glass, and the minimum halftone dot area ratio at which no development failure occurred was evaluated as image reproducibility. The smaller the halftone dot area ratio, the better the image reproducibility.

[0238] (11) Uneven printing

[0239] The following four types of screens were used for latent image formation in the exposure step, and printing plates were obtained under the exposure and development conditions described in the above section (10) in addition to the above.

[0240] <Types of Screens>

[0241] AM Screen-1: AM Screen 175 lines (resolution: 2400dpi)

[0242] AM Screen-2: AM Screen 210 lines (resolution: 2400dpi)

[0243] AM / FM hybrid screen-1: Fairdot2-350 (equivalent to AM screen 350 lines, resolution: 2400dpi)

[0244] AM / FM hybrid screen-2: Fairdot2-650 (equivalent to AM screen 650 lines, resolution: 2400dpi).

[0245] The resulting printing plate was mounted on the plate cylinder of an EB offset printing press: OFFSET CI / 8 (manufactured by COMEXI Co., Ltd.), and printing was performed under the following printing and ink curing conditions. The presence of uneven printing on each printed product was visually evaluated. The less uneven printing was observed on a screen equivalent to a higher precision screen, the more suppressed the uneven printing was.

[0246] <Printing conditions>

[0247] Ink roller: #8000( (Manufactured by Co., Ltd.)

[0248] Rubber blanket: MC1300 (manufactured by Kinyo Co., Ltd.)

[0249] Water-soluble EB ink: Offset EB ink F type FE1908 red ( (Manufactured by Co., Ltd.)

[0250] Ink composition non-absorbent printed medium: "(Registered trademark) PTM-12 (rolled biaxially stretched PET film, thickness: 12μm, printed surface: easy-adhesion treatment, (Manufactured by Co., Ltd.)

[0251] Surface temperature: 28±2℃

[0252] Printing speed: 150m / min

[0253] Solid part reflection density: 1.50±0.05

[0254] <Ink curing conditions>

[0255] EB irradiation dose: 40 kGy

[0256] EB irradiation atmosphere: nitrogen atmosphere.

[0257] (12) Ink repellency

[0258] Cut the printed material obtained in item (11) above, which is about 500m from the printing starting point, and place it on 5 overlapping sheets of coated paper: OK ” (registered trademark) + (manufactured by Oji Paper Co., Ltd.), using a spectrophotometer / colorimeter: (manufactured by X-Rite) and measured the reflection density of the white solid area (corresponding to the area ratio of halftone dots: 0%). The lower the reflection density, the better the ink repellency.

[0259] (13) Printing durability

[0260] The printing plate obtained in (10) above was mounted on the plate cylinder of an EB offset printing press: OFFSET CI / 8 (manufactured by COMEXI Co., Ltd.), and printing was carried out under the printing conditions and ink curing conditions described in (11) above. Samples of printed material were taken every 5,000 m. The presence of unwanted lines, i.e., bottom stain, in the non-line portion of the printing position corresponding to the 0% dot area ratio portion (1,070 mm × 120 mm) of the printing plate was observed. The limit printing length at which bottom stain was not observed was evaluated as the press life. The longer the limit printing length, the better the press life.

[0261] [Example 1]

[0262] An aluminum alloy plate with a thickness of 0.24 mm and a surface arithmetic mean roughness (Ra) of 0.18 μm was used as a support. (manufactured by Co., Ltd.), the average film mass after heating was 8.0 g / m 2 The following primer layer forming composition-1 was applied in a manner of 100° C. and heated at 180° C. for 2 minutes to set an average film weight of 8.0 g / m 2 primer layer.

[0263] <Primer layer forming composition-1>

[0264] (a) Epoxy resin: "jER (registered trademark)" 1010 ( (Co., Ltd.), solid content concentration: 100% by mass: 18 parts by mass

[0265] (b) Polyurethane: (Registered trademark)" LQ-T1331D (manufactured by Sanyo Chemical Industries, Ltd., N,N-dimethylformamide / 2-ethoxyethanol solution (solid content concentration: 20% by mass): 285 parts by mass (polyurethane: 57 parts by mass)

[0266] (c) Aluminum tris(ethyl acetoacetate): ALCH-TR( (Co., Ltd.), solid content concentration: 100% by mass: 4 parts by mass

[0267] (d) Vinyl polymers: (Registered trademark) LC951 (manufactured by Kusumoto Chemicals Co., Ltd., diluent solution (solid content concentration: 10% by mass): 0.1 part by mass

[0268] (e) Titanium oxide dispersion (N,N-dimethylformamide dispersion (solid content concentration: 50% by mass): 42 parts by mass (titanium oxide: 21 parts by mass)

[0269] (f) N,N-dimethylformamide: 1445 parts by mass

[0270] (g) Methyl ethyl ketone: 1540 parts by mass.

[0271] <Preparation of Titanium Oxide Dispersion>

[0272] To 50 parts by mass of N,N-dimethylformamide, 50 parts by mass of titanium oxide "CR-50 (manufactured by Ishihara Sangyo Co., Ltd.)" was added and stirred for 5 minutes. Furthermore, 75 parts by mass of glass beads (No. 08) were added and vigorously stirred for 20 minutes. The glass beads were then removed to obtain a titanium oxide dispersion.

[0273] The following heat-sensitive layer-forming composition-1 was applied to the primer layer using a slot die coater and heated at 150° C. for 80 seconds to set an average film weight of 1.5 g / m 2 The heat-sensitive layer of the heat-melting type.

[0274] <Thermosensitive layer forming composition-1>

[0275] (a) Near-infrared absorbing dye: PROJET 825LDI (manufactured by Avecia Co., Ltd., solid content concentration: 100% by mass): 10 parts by mass

[0276] (b) Titanium bis(2,4-pentanedionato)di-n-butoxide: (Registered trademark) "Titanium" (manufactured by Nippon Chemical Industry Co., Ltd., titanium concentration: 8.8% by mass, n-butanol solution (solid content concentration: 73% by mass): 22 parts by mass

[0277] (c) Phenol novolac resin: (Registered Trademark)”PR54652( (Co., Ltd.), solid content concentration: 100% by mass: 60 parts by mass

[0278] (d)“ (Registered trademark)" LQ-T1331D: 50 parts by mass

[0279] (e) 3-glycidoxypropyltrimethoxysilane: 15 parts by mass

[0280] (f) Tetrahydrofuran: 668 parts by mass

[0281] (g) Ethanol: 40 parts by mass.

[0282] The following silicone rubber layer-forming composition was applied to the heat-sensitive layer using a slot die coater and heated at 125° C. for 80 seconds to set the average film weight to 2.0 g / m 2 The silicone rubber layer was formed to obtain a printing plate precursor. The concentration of H groups derived from SiH groups in the total solid content of the composition for forming the silicone rubber layer was 0.013% by mass.

[0283] <Silicone Rubber Layer-Forming Composition>

[0284] (a) α,ω-divinylpolydimethylsiloxane: DMS-V52 (weight average molecular weight 110,000, manufactured by GELEST Inc., solid content concentration: 100% by mass): 100 parts by mass

[0285] (b) Methylhydrogenpolysiloxane / dimethylsiloxane copolymer with trimethylsilyl groups at both ends: HMS-151 (mol% of MeHSiO: 15-18%, manufactured by GELEST Inc., solid content: 100% by mass): 7 parts by mass

[0286] (c) Vinyltri(methylethylketoxime)silane: 3 parts by mass

[0287] (d) Platinum catalyst: SRX-212 ( Co., Ltd., solid content concentration: 85.6% by mass: 5 parts by mass

[0288] (e)“ (Registered Trademark)"E( (manufactured by Co., Ltd.): 1035 parts by weight.

[0289] [Example 2]

[0290] A printing plate precursor was obtained by the same method as in Example 1 except that the primer layer-forming composition-1 was changed to the following primer layer-forming composition-2.

[0291] <Primer layer forming composition-2>

[0292] (a) "jER (registered trademark)" 1010: 16 parts by mass

[0293] (b) Polyurethane: (Registered trademark)" LQ-SZ18D (manufactured by Sanyo Chemical Industries, Ltd., N,N-dimethylformamide solution (solid content concentration: 15% by mass): 480 parts by mass (polyurethane: 72 parts by mass)

[0294] (c)“ ALCH-TR: 4 parts by mass

[0295] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0296] (e) Titanium oxide dispersion: 16 parts by mass

[0297] (f) N,N-dimethylformamide: 2818 parts by mass.

[0298] [Example 3]

[0299] A printing plate precursor was obtained by the same method as in Example 1 except that the primer layer-forming composition-1 was changed to the following primer layer-forming composition-3.

[0300] <Primer layer forming composition-3>

[0301] (a) "jER (registered trademark)" 1010: 28 parts by mass

[0302] (b)“ (Registered trademark)" LQ-T1331D: 160 parts by mass

[0303] (c)“ ALCH-TR: 6 parts by mass

[0304] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0305] (e) Titanium oxide dispersion: 68 parts by mass

[0306] (f) N,N-dimethylformamide: 2102 parts by mass

[0307] (g) Methyl ethyl ketone: 969 parts by mass.

[0308] [Example 4]

[0309] A printing plate precursor was obtained by the same method as in Example 1 except that the primer layer-forming composition-1 was changed to the following primer layer-forming composition-4.

[0310] <Primer layer forming composition-4>

[0311] (a) "jER (registered trademark)" 1010: 36 parts by mass

[0312] (b)“ (Registered trademark)" LQ-T1331D: 110 parts by mass

[0313] (c)“ ALCH-TR: 8 parts by mass

[0314] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0315] (e) Titanium oxide dispersion: 68 parts by mass

[0316] (f) N,N-dimethylformamide: 2142 parts by mass

[0317] (g) Methyl ethyl ketone: 969 parts by mass.

[0318] [Example 5]

[0319] A printing plate precursor was obtained by the same method as in Example 1 except that the primer layer-forming composition-1 was changed to the following primer layer-forming composition-5.

[0320] <Primer layer forming composition-5>

[0321] (a) "jER (registered trademark)" 1010: 46 parts by mass

[0322] (b)“ (Registered trademark)" LQ-T1331D: 50 parts by mass

[0323] (c)“ ALCH-TR: 10 parts by mass

[0324] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0325] (e) Titanium oxide dispersion: 68 parts by mass

[0326] (f) N,N-dimethylformamide: 2190 parts by mass

[0327] (g) Methyl ethyl ketone: 969 parts by mass.

[0328] [Example 6]

[0329] A printing plate precursor was obtained by the same method as in Example 1 except that the primer layer-forming composition-1 was changed to the following primer layer-forming composition-6.

[0330] <Primer layer forming composition-6>

[0331] (a) "jER (registered trademark)" 1010: 41 parts by mass

[0332] (b)“ (Registered trademark)" LQ-T1331D: 235 parts by mass

[0333] (c)“ ALCH-TR: 9 parts by mass

[0334] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0335] (e) Titanium oxide dispersion: 6 parts by mass

[0336] (f) N,N-dimethylformamide: 2073 parts by mass

[0337] (g) Methyl ethyl ketone: 969 parts by mass.

[0338] [Example 7]

[0339] The average film weight after heating is 3.5 g / m 2 The primer layer forming composition-1 was applied in a manner to set the average film weight to 3.5 g / m 2 A printing plate precursor was obtained by the same method as in Example 1 except that a primer layer was formed.

[0340] [Example 8]

[0341] The average film weight after heating is 5.0 g / m 2 The primer layer forming composition-1 was applied in a manner to set the average film weight to 5.0 g / m 2A printing plate precursor was obtained by the same method as in Example 1 except that a primer layer was formed.

[0342] [Example 9]

[0343] The average film weight after heating was 11.0 g / m 2 The primer layer forming composition-1 was applied in a manner to set the average film weight to 11.0 g / m 2 A printing plate precursor was obtained by the same method as in Example 1 except that a primer layer was formed.

[0344] [Example 10]

[0345] The average film weight after heating is 500.0 g / m 2 The primer layer forming composition-5 was applied in a manner to set an average film weight of 500.0 g / m 2 A printing plate precursor was obtained by the same method as in Example 5 except that a primer layer was formed.

[0346] [Example 11]

[0347] The average film mass after heating is 700.0 g / m 2 The primer layer forming composition-5 was applied in a manner to set an average film weight of 700.0 g / m 2 A printing plate precursor was obtained by the same method as in Example 5 except that a primer layer was formed.

[0348] [Example 12]

[0349] The average film weight after heating is 900.0 g / m 2 A printing plate precursor was obtained by the same method as in Example 5 except that the primer layer forming composition-5 was applied in the manner of .Dripping occurred during the application of the primer layer forming composition, and the average film weight of the primer layer was 808.0 g / m 2 .

[0350] [Example 13]

[0351] The thermosensitive layer-forming composition-1 was changed to the following thermosensitive layer-forming composition-2, and the average film weight of the thermosensitive layer was changed to 1.8 g / m 2 , except for this, a printing plate precursor was obtained by the same method as in Example 9. It should be noted that the obtained heat-sensitive layer was a heat-destructible heat-sensitive layer.

[0352] <Thermosensitive layer forming composition-2>

[0353] (a) Methylated melamine resin: "CYMEL (registered trademark)" 303: 50.16 parts by mass

[0354] (b) Blue pigment: Victoria Blue BODye: 0.69 parts by mass

[0355] (c) Phosphate ester: "Lubrizol (registered trademark)" 2062: 0.50 parts by mass

[0356] (d) Near infrared absorbing dye: S009NIRDye: 28.09 parts by mass

[0357] (e) p-Toluenesulfonic acid catalyst: "Cycat (registered trademark)" 4040: 4.20 parts by mass

[0358] (f) Surfactant: "BYK" 307: 1.31 parts by mass

[0359] (g) Nitrocellulose resin: "Walsroder (registered trademark)" E400NC: 15.05 parts by mass

[0360] (h) 1-methoxypropane-2-ol: 550.00 parts by mass

[0361] (i) N-methyl-2-pyrrolidone: 129.00 parts by mass.

[0362] [Example 14]

[0363] A printing plate precursor was obtained by the same method as in Example 8 except that the aluminum alloy plate having a surface arithmetic mean roughness (Ra) of 0.27 μm was used.

[0364] [Example 15]

[0365] A printing plate precursor was obtained by the same method as in Example 8 except that the aluminum alloy plate having a surface arithmetic mean roughness (Ra) of 0.39 μm was used.

[0366] [Example 16]

[0367] A printing plate precursor was obtained by the same method as in Example 11 except that the primer layer forming composition-5 was replaced with the following primer layer forming composition-7. Dripping occurred during application of the primer layer forming composition, and the average film weight of the primer layer was 628.5 g / m 2 .

[0368] <Primer layer forming composition-7>

[0369] (a) "jER (registered trademark)" 1010: 46 parts by mass

[0370] (b)“ (Registered trademark)" LQ-T1331D: 50 parts by mass

[0371] (c) ALCH-TR: 10 parts by mass

[0372] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0373] (e) Titanium oxide dispersion: 68 parts by mass

[0374] (f) N,N-dimethylformamide: 6857 parts by mass

[0375] (g) Methyl ethyl ketone: 2970 parts by mass.

[0376] [Example 17]

[0377] A printing plate precursor was obtained by the same method as in Example 2 except that the primer layer-forming composition-2 was changed to the following primer layer-forming composition-8.

[0378] <Primer layer forming composition-8>

[0379] (a) "jER (registered trademark)" 1010: 16 parts by mass

[0380] (b)“ (Registered trademark)" LQ-SZ18D: 480 parts by mass

[0381] (c) ALCH-TR: 4 parts by mass

[0382] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0383] (e) Titanium oxide dispersion: 16 parts by mass

[0384] (f) N,N-dimethylformamide: 914 parts by mass

[0385] (g) Methyl ethyl ketone: 570 parts by mass.

[0386] [Example 18]

[0387] The average film weight of the silicone rubber layer was changed to 3.4 g / m 2 , except for this, a printing plate precursor was obtained by the same method as in Example 9.

[0388] [Example 19]

[0389] The average film weight of the silicone rubber layer was changed to 4.4 g / m 2 , except for this, a printing plate precursor was obtained by the same method as in Example 9.

[0390] [Example 20]

[0391] The average film weight of the silicone rubber layer was changed to 5.0 g / m 2 , except for this, a printing plate precursor was obtained by the same method as in Example 9.

[0392] [Example 21]

[0393] A printing plate precursor was obtained by the same method as in Example 9, except that (b) 7 parts by mass of HMS-151 in the silicone rubber layer-forming composition was replaced with 4 parts by mass of (b) methylhydrogen polysiloxane with trimethylsilyl groups at both ends: HMS-991 (mol% of MeHSiO: 100%, manufactured by GELEST Inc., solid content concentration: 100% by mass). The concentration of H groups derived from SiH groups in the total solid content of the silicone rubber layer-forming composition was 0.054% by mass.

[0394] [Example 22]

[0395] A printing plate precursor was obtained by the same method as in Example 21, except that the amount of (b) HMS-991 in the silicone rubber layer-forming composition was changed to 5.5 parts by mass. The concentration of H groups derived from SiH groups in the total solids content of the silicone rubber layer-forming composition was 0.073% by mass.

[0396] [Example 23]

[0397] A printing plate precursor was obtained by the same method as in Example 21, except that the amount of (b) HMS-991 in the silicone rubber layer-forming composition was changed to 10 parts by mass. The concentration of H groups derived from SiH groups in the total solids content of the silicone rubber layer-forming composition was 0.127% by mass.

[0398] [Example 24]

[0399] A printing plate precursor was obtained by the same method as in Example 21, except that the amount of (b) HMS-991 in the silicone rubber layer-forming composition was changed to 11.5 parts by mass. The concentration of H groups derived from SiH groups in the total solids content of the silicone rubber layer-forming composition was 0.145% by mass.

[0400] [Example 25]

[0401] The average film weight after heating is 3.5 g / m 2 The primer layer forming composition-1 was applied in a manner to set the average film weight to 3.5 g / m2 A printing plate precursor was obtained by the same method as in Example 13 except that a primer layer was formed.

[0402] [Example 26]

[0403] The average film weight after heating is 5.0 g / m 2 The primer layer forming composition-1 was applied in a manner to set the average film weight to 5.0 g / m 2 A printing plate precursor was obtained by the same method as in Example 13 except that a primer layer was formed.

[0404] [Example 27]

[0405] The average film weight after heating is 8.0 g / m 2 The primer layer forming composition-1 was applied in a manner to set the average film weight to 8.0 g / m 2 A printing plate precursor was obtained by the same method as in Example 13 except that a primer layer was formed.

[0406] [Comparative Example 1]

[0407] A printing plate precursor was obtained by the same method as in Example 1 except that the primer layer-forming composition-1 was changed to the following primer layer-forming composition-9.

[0408] <Primer layer forming composition-9>

[0409] (a) "jER (registered trademark)" 1010: 18 parts by mass

[0410] (b)“ (Registered trademark)" LQ-T1331D: 285 parts by mass

[0411] (c) ALCH-TR: 4 parts by mass

[0412] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0413] (e) Titanium oxide dispersion: 42 parts by mass

[0414] (f) N,N-dimethylformamide: 48 parts by mass

[0415] (g) Methyl ethyl ketone: 270 parts by mass.

[0416] [Comparative Example 2]

[0417] A printing plate precursor was obtained by the same method as in Example 2 except that the primer layer-forming composition-2 was changed to the following primer layer-forming composition-10.

[0418] <Primer layer forming composition-10>

[0419] (a) "jER (registered trademark)" 1010: 16 parts by mass

[0420] (b)“ (Registered trademark)" LQ-SZ18D: 480 parts by mass

[0421] (c) ALCH-TR: 4 parts by mass

[0422] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0423] (e) Titanium oxide dispersion: 16 parts by mass

[0424] (f) N,N-Dimethylformamide: 151 parts by mass.

[0425] [Comparative Example 3]

[0426] A printing plate precursor was obtained by the same method as in Example 2 except that the primer layer-forming composition-2 was changed to the following primer layer-forming composition-11.

[0427] <Primer layer forming composition-11>

[0428] (a) "jER (registered trademark)" 1010: 16 parts by mass

[0429] (b)“ (Registered trademark)" LQ-SZ18D: 480 parts by mass

[0430] (c) ALCH-TR: 4 parts by mass

[0431] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0432] (e) Titanium oxide dispersion: 16 parts by mass

[0433] (f) N,N-dimethylformamide: 514 parts by mass

[0434] (g) Methyl ethyl ketone: 399 parts by mass.

[0435] [Comparative Example 4]

[0436] A printing plate precursor was obtained by the same method as in Example 3 except that the primer layer-forming composition-3 was changed to the following primer layer-forming composition-12.

[0437] <Primer layer forming composition-12>

[0438] (a) "jER (registered trademark)" 1010: 28 parts by mass

[0439] (b)“ (Registered trademark)" LQ-T1331D: 160 parts by mass

[0440] (c) ALCH-TR: 6 parts by mass

[0441] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0442] (e) Titanium oxide dispersion: 68 parts by mass

[0443] (f) N,N-dimethylformamide: 235 parts by mass

[0444] (g) Methyl ethyl ketone: 170 parts by mass.

[0445] [Comparative Example 5]

[0446] A printing plate precursor was obtained by the same method as in Example 4 except that the primer layer-forming composition-4 was changed to the following primer layer-forming composition-13.

[0447] <Primer layer forming composition-13>

[0448] (a) "jER (registered trademark)" 1010: 36 parts by mass

[0449] (b)“ (Registered trademark)" LQ-T1331D: 110 parts by mass

[0450] (c) ALCH-TR: 8 parts by mass

[0451] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0452] (e) Titanium oxide dispersion: 68 parts by mass

[0453] (f) N,N-dimethylformamide: 275 parts by mass

[0454] (g) Methyl ethyl ketone: 170 parts by mass.

[0455] [Comparative Example 6]

[0456] A printing plate precursor was obtained by the same method as in Example 5 except that the primer layer-forming composition-5 was changed to the following primer layer-forming composition-14.

[0457] <Primer layer forming composition-14>

[0458] (a) "jER (registered trademark)" 1010: 46 parts by mass

[0459] (b)“ (Registered trademark)" LQ-T1331D: 50 parts by mass

[0460] (c) ALCH-TR: 10 parts by mass

[0461] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0462] (e) Titanium oxide dispersion: 68 parts by mass

[0463] (f) N,N-dimethylformamide: 323 parts by mass

[0464] (g) Methyl ethyl ketone: 170 parts by mass.

[0465] [Comparative Example 7]

[0466] A printing plate precursor was obtained by the same method as in Example 6 except that the primer layer-forming composition-6 was changed to the following primer layer-forming composition-15.

[0467] <Primer layer forming composition-15>

[0468] (a) "jER (registered trademark)" 1010: 41 parts by mass

[0469] (b)“ (Registered trademark)" LQ-T1331D: 235 parts by mass

[0470] (c) ALCH-TR: 9 parts by mass

[0471] (d)“ (Registered trademark)" LC951: 0.1 parts by mass

[0472] (e) Titanium oxide dispersion: 6 parts by mass

[0473] (f) N,N-dimethylformamide: 206 parts by mass

[0474] (g) Methyl ethyl ketone: 170 parts by mass.

[0475] [Comparative Example 8]

[0476] The average film weight after heating was 16.0 g / m 2 The primer layer forming composition-10 was applied in a manner to set the average film weight to 16.0 g / m 2 A printing plate precursor was obtained by the same method as in Comparative Example 2 except that a primer layer of was provided.

[0477] [Comparative Example 9]

[0478] The average film weight after heating was 16.0 g / m 2 The primer layer forming composition-15 was applied in a manner to set the average film weight to 16.0 g / m 2 A printing plate precursor was obtained by the same method as in Comparative Example 7 except that a primer layer of was provided.

[0479] [Comparative Example 10]

[0480] The average film weight after heating was 11.0 g / m 2 The primer layer forming composition-9 was applied in a manner to set the average film weight to 16.0 g / m 2 The primer layer was changed from the heat-sensitive layer-forming composition-1 to the heat-sensitive layer-forming composition-2, and the average film weight of the heat-sensitive layer was changed to 1.8 g / m 2 A printing plate precursor was obtained by the same method as in Comparative Example 1 except for the above.

[0481] The evaluation results of Examples 1 to 27 and Comparative Examples 1 to 10 are shown in Tables 1 to 4.

[0482] [Table 1]

[0483] [Table 2]

[0484] [Table 3]

[0485] [Table 4]

[0486] Explanation of symbols

[0487] 1 support

[0488] 2 primer layers

[0489] 3 heat-sensitive layers

[0490] 4 silicone rubber layers

[0491] a0 Base height of primer layer

[0492] a1 Average thickness of primer layer

[0493] a2 Thickness of the thinnest part of the primer layer

[0494] a3 Maximum peak height in the surface of the primer layer

[0495] a4 The portion that protrudes from the base height of the primer layer

[0496] a5: The portion that is recessed from the base height of the primer layer

[0497] a6 Intersection point of the base height of the primer layer and the line representing the interface between the primer layer and the heat-sensitive layer

[0498] b0 Base height of thermal sensitive layer

[0499] b1 Average thickness of the heat-sensitive layer

[0500] b2 Thickness of the thinnest part of the heat-sensitive layer

[0501] b3: The portion protruding from the reference height of the heat-sensitive layer

[0502] b4: A portion that is recessed from the reference height of the heat-sensitive layer.

[0503] c0 Reference height of the support

[0504] c1 The portion that protrudes from the base height of the support

[0505] c2 is a portion that is recessed from the reference height of the support.

Claims

1. A direct drawing type waterless planographic printing plate precursor comprising a primer layer, a heat-sensitive layer, and a silicone rubber layer in this order on a support, wherein, in a cross section of the direct drawing type waterless planographic printing plate precursor, within a width of 750 μm of the primer layer, the sum of the areas of portions protruding from a reference height of the primer layer and the areas of portions recessed from the reference height of the primer layer is 0 to 60 μm. 2 . 2 . The direct drawing waterless planographic printing plate precursor according to claim 1 , wherein within a range of 750 μm in width of the primer layer in the cross section, the number of intersections between a reference height of the primer layer and a line representing an interface between the primer layer and the heat-sensitive layer is 0 to 600.

3. A direct drawing type waterless planographic printing plate precursor comprising a primer layer, a heat-sensitive layer, and a silicone rubber layer in this order on a support, wherein the maximum peak height on the surface of the primer layer is 0.5 μm or less. 4 . The direct drawing waterless planographic printing plate precursor according to claim 1 , wherein the heat-sensitive layer has a thickness of 0.2 μm or more at its thinnest portion. 5 . The direct drawing waterless planographic printing plate precursor according to claim 1 , wherein the primer layer has a thickness of 1 μm or more at its thinnest portion.

6. The direct drawing waterless planographic printing plate precursor according to any one of claims 1 to 3, wherein, within a width of 750 μm of the heat-sensitive layer in a cross section, the sum of the total area of ​​a portion protruding from a reference height of the heat-sensitive layer and the total area of ​​a portion recessed from the reference height of the heat-sensitive layer is 0 to 30 μm. 2 . 7 . The direct drawing waterless planographic printing plate precursor according to claim 1 , wherein the primer layer has an average thickness of 2 to 500 μm. 8 . The direct drawing waterless planographic printing plate precursor according to claim 1 , wherein the heat-sensitive layer has an average thickness of 0.5 to 2 μm. 9 . The direct drawing waterless planographic printing plate precursor according to claim 1 , wherein the silicone rubber layer has an average thickness of 3.2 to 4.8 μm. 10 . The direct drawing waterless planographic printing plate precursor according to claim 1 , wherein the heat-sensitive layer is heat-destructible. 11 . The direct drawing waterless planographic printing plate precursor according to claim 1 , wherein the silicone rubber layer comprises a hard domain.

12. The direct drawing waterless planographic printing plate precursor according to any one of claims 1 to 3, wherein, within a range of 750 μm in width of the support in a cross section, the sum of the total area of ​​the portion protruding from the base height of the support and the total area of ​​the portion recessed from the base height of the support is 0 to 300 μm. 2 .

13. A method for manufacturing a waterless planographic printing plate, comprising: an exposure step of irradiating a direct-drawing waterless planographic printing plate precursor according to any one of claims 1 to 3 with laser light to form a latent image; and a development step of removing a silicone rubber layer corresponding to a line portion of the latent image.

14. The method for producing a waterless planographic printing plate according to claim 13, wherein in the exposure step for forming the latent image, an AM screen or an AM / FM hybrid screen having a precision equivalent to 180 to 650 lines of AM screen is used.

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