A seamless lithographic printing plate original, a seamless lithographic printing plate, a method for regenerating a cylindrical support, a method for manufacturing a seamless lithographic printing plate original, and a composition for forming an easy-to-peel primer layer

Abstract

The present invention aims at obtaining a seamless planographic printing plate precursor and a seamless planographic printing plate, which are excellent in image reproducibility necessary for obtaining a high-fineness seamless planographic printed matter. Further, it aims at obtaining a seamless planographic printing plate precursor and a seamless planographic printing plate, which are easy to regenerate the cylindrical support. The present invention is a seamless planographic printing plate precursor having, in order on the outer circumferential surface of a cylindrical support, a respective continuous easy-peeling primer layer and an ink-repellent layer.

Description

Technical Field

[0001] This invention relates to a seamless lithographic printing plate master, a seamless lithographic printing plate, a method for regenerating a cylindrical support, a method for manufacturing a seamless lithographic printing plate master, and a composition for forming an easily peelable primer layer. Background Technology

[0002] Printing encompasses various methods such as letterpress printing, gravure printing, screen printing, and offset printing, each leveraging its unique characteristics. Among these, offset printing offers advantages over other methods, particularly in producing prints with high precision.

[0003] In the field of flexible packaging printing, seamless printing is performed by repeatedly forming discontinuous or continuous patterns on long (strip) printed media. Regarding printing for seamless printing, methods have been proposed such as: a method for manufacturing a lithographic printing component by coating a hollow printing cylinder with a first radiation-sensitive polymer layer and a silicon layer (for example, see Patent Document 1); and a method for coating a cylindrical surface with a coating that has been transformed to be compatible with oil and water and then cured (for example, see Patent Document 2). Furthermore, as a method for mounting a printing plate to a sleeve that allows for easy removal of the printing plate, a method has been proposed that includes a protective layer forming step for forming a protective layer on the outer circumferential surface of the sleeve to protect the outer circumferential surface of the sleeve, and a printing plate bonding step for bonding the printing plate to the surface of the adhesive layer. The protective layer includes a heat-shrinkable film (for example, see Patent Document 3).

[0004] Existing technical documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 7-309001

[0006] Patent Document 2: Japanese Patent Application Publication No. 9-99535

[0007] Patent Document 3: Japanese Patent Application Publication No. 2006-231758 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] Cylindrical supports, such as plate cylinders or plate cylinder sleeves, are useful as supports for seamless lithographic printing plates. They are not only expensive, but from an environmental perspective, it is also desirable to recycle the cylindrical supports from the printed seamless lithographic printing plates and use the recycled cylindrical supports to repeatedly manufacture seamless lithographic printing plates.

[0010] Although the seamless lithographic printing plates described in Patent Documents 1 and 2 can produce highly precise seamless printed materials, the support / ink-repellent layer and the support / adhesive layer are firmly bonded by chemical bonds. Therefore, in order to regenerate the support, complex operations such as wet processes such as solvent cleaning and grinding of the outer peripheral surface of the support are required.

[0011] The seamless lithographic printing plate described in Patent Document 3 has the following advantages: it produces highly detailed seamless prints; furthermore, the sleeve can be recycled by peeling off the heated heat-shrink film using a dry process. However, because the single-sheet lithographic printing plate is wound onto the sleeve, there is a seam between the head and tail of the plate, thus preventing the production of seamless prints with continuous patterns.

[0012] Therefore, the problem to be solved by the present invention is to provide a cylindrical support that is easy to regenerate and can produce a seamless lithographic printing plate original with high-precision continuous patterns.

[0013] Problem-solving methods

[0014] To address the aforementioned issues, the present invention is as follows.

[0015] [1]. A seamless lithographic printing plate original, having a continuous peelable primer layer and an ink-repellent layer on the outer circumferential surface of a cylindrical support.

[0016] [2]. As described in [1], the adhesion force between the cylindrical support and the easily peelable primer layer is less than the film strength of the easily peelable primer layer.

[0017] [3]. The seamless lithographic printing plate original as described in [1] or [2], wherein the adhesion force between the cylindrical support and the easily peelable primer layer is 10 to 2000 N / m.

[0018] [4]. The seamless lithographic printing plate original as described in any of [1] to [3], wherein the elongation at break of the easily peelable primer layer is 10 to 1000%.

[0019] [5]. The seamless lithographic printing plate original as described in any of [1] to [4], wherein the average thickness of the easily peelable primer layer is 15 to 500 μm.

[0020] [6]. The seamless lithographic printing plate original as described in any of [1] to [5], wherein the easily peelable primer layer contains a compound having a functional group having a cohesion energy of 20 to 60 kJ / mol.

[0021] [7]. The seamless lithographic printing plate original as described in any of [1] to [6], wherein the easily peelable primer layer and the outer peripheral surface of the cylindrical support do not have covalent bonds.

[0022] [8]. The seamless lithographic printing plate original as described in [6] contains polyurethane as the compound having a functional group with a cohesion energy of 20 to 60 kJ / mol.

[0023] [9]. The seamless lithographic printing plate original as described in any of [1] to [8], wherein the ink-repellent layer is an organosilicon layer.

[0024]

[10] . The seamless lithographic printing plate original as described in any of [1] to [9] has an ink layer continuously between the peelable primer layer and the ink-repellent layer, or further outside the ink-repellent layer.

[0025]

[11] . The seamless offset printing plate original as described in

[10] , wherein the ink layer is a photosensitive layer or a thermosensitive layer.

[0026]

[12] . A seamless lithographic printing plate, which is obtained by making a plate from any one of the seamless lithographic printing plate originals described in [1] to

[11] .

[0027]

[13] . A method for regenerating a cylindrical support, wherein the easily peelable primer layer is peeled off into a film from the outer periphery of the cylindrical support of the seamless lithographic printing plate original or the seamless lithographic printing plate described in any one of [1] to

[11] or

[12] by a dry process.

[0028]

[14] . A method for manufacturing a seamless lithographic printing plate original, wherein an easy-to-peel primer layer and an ink-repellent layer are sequentially and continuously formed on the outer peripheral surface of a cylindrical support regenerated by the method described in

[13] .

[0029]

[15] . A method for manufacturing a seamless lithographic printing plate original is a method for manufacturing a seamless lithographic printing plate original as described in any one of [1] to

[11] , wherein a composition for forming an easy-to-peel primer layer is coated on the outer peripheral surface of a cylindrical support, and dried under heating or without heating, thereby forming the easy-to-peel primer layer.

[0030]

[16] . A method for manufacturing a seamless lithographic printing plate original is a method for manufacturing a seamless lithographic printing plate original as described in any one of [1] to

[11] , wherein an easy-to-peel primer layer forming composition is coated on the outer peripheral surface of a cylindrical support, and the easy-to-peel primer layer forming composition is cured by irradiation with active energy rays, thereby forming the easy-to-peel primer layer.

[0031]

[17] . The method for manufacturing a seamless lithographic printing plate original as described in

[15] or

[16] uses a cylindrical support regenerated by the method described in

[13] as a cylindrical support.

[0032]

[18] . A composition for forming an easy-to-peel primer layer, comprising a compound having a functional group having a cohesion energy of 20 to 60 kJ / mol.

[0033]

[19] . The composition for forming an easy-to-peel primer layer as described in

[18] , as the compound having a functional group having a cohesion energy of 20 to 60 kJ / mol, contains a compound having a carbamate bond and / or a hydroxyl group.

[0034]

[20] . The composition for forming an easy-to-peel primer layer as described in

[18] or

[19] , wherein the compound having a functional group having a cohesion energy of 20 to 60 kJ / mol also has an alkene unsaturated double bond in the molecule.

[0035]

[21] . The composition for forming an easy-to-peel primer layer as described in

[19] contains polyurethane as the compound having functional groups with a cohesion energy of 20 to 60 kJ / mol.

[0036]

[22] . The composition for forming an easy-peel primer layer as described in any of

[18] to

[21] further contains inorganic particles.

[0037] Invention Effects

[0038] According to the present invention, it is possible to obtain a seamless lithographic printing plate original that is easy to regenerate from a cylindrical support and can produce a high-precision continuous pattern. Attached Figure Description

[0039] Figure 1 This is a simplified diagram illustrating the difference between discontinuous and continuous patterns in seamless printing.

[0040] Figure 2 This is a schematic cross-sectional view illustrating an example of a method for manufacturing seamless printed materials. Detailed Implementation

[0041] The seamless lithographic printing plate of the present invention refers to a printing plate original used for seamless printing, which has an easily peelable primer layer and an ink-repellent layer sequentially and continuously on the outer peripheral surface of a cylindrical support. Hereinafter, the seamless lithographic printing plate original is sometimes referred to as the "original plate".

[0042] Seamless printing in this invention refers to a method of repeatedly printing the same pattern or design onto a long printing medium. This printing method yields seamless printed materials with discontinuous or continuous patterns repeatedly formed on the printing medium. The lithographic printing plate used for seamless printing is called a seamless lithographic printing plate. A seamless lithographic printing plate can be obtained from the original seamless lithographic printing plate using, for example, the method described later. Hereinafter, the seamless lithographic printing plate is sometimes referred to as a "printing plate".

[0043] Here, use Figure 1 This invention explains the difference between discontinuous and continuous patterns in seamless printing. Figure 1 This is a schematic diagram illustrating the difference between discontinuous pattern A and continuous pattern B in seamless printing. Figure 1 The left and right sides respectively show a seamless lithographic printing plate E used for seamless printing discontinuous and continuous patterns, and a seamless printed object F obtained by seamless printing using the seamless lithographic printing plate E. The seamless lithographic printing plate E has an ink-attached drawing section 1 and an ink-free non-drawing section 2. In the case of discontinuous patterns, the drawing section 1 (pattern) is arranged discontinuously with respect to the printing direction D, and in the case of continuous patterns, the drawing section 1 (pattern) is arranged continuously with respect to the printing direction D. In seamless printing, the ink attached to the drawing section 1 is transferred directly or via a blanket to the printing medium 3 to form a transfer pattern 4.

[0044] In the printing plate described in Japanese Patent Application Publication No. 2006-231758, which is exemplified as prior art patent document 3, or in the printing plate described in Comparative Example 3 described later, a single sheet of planar printing plate is wound around the outer peripheral surface of a cylindrical support, and an ink-repellent layer forming composition is filled into the gap between the plate head and the plate tail, and then cured to form an ink-repellent portion (non-line drawing portion). Therefore, by arranging the pattern in the ink-repellent portion (non-line drawing portion) of the gap between the plate head and the plate tail in a manner consistent with the interrupted portion of the pattern in the discontinuous pattern, a seamless printed product with a discontinuous pattern can be obtained. However, since a line drawing portion cannot be formed in the ink-repellent portion of the gap between the plate head and the plate tail, a seamless printed product with a continuous pattern without interrupted portions in the pattern cannot be obtained.

[0045] In the original version of this invention, the easily peelable primer layer or ink-repellent layer, as well as other functional layers, are continuously disposed without gaps in the circumferential or axial direction of the original plate. Therefore, it is possible to produce a printing plate with continuous, gapless lines in the circumferential direction, and to obtain seamless printed materials with continuous patterns in the design without interruptions. Here, "continuous" refers to the state in which the functional layers are disposed without gaps in the circumferential or axial direction on the original plate.

[0046] For example, when the easily peelable primer layer has ink-receptivity, when an ink-receptivity layer is continuously present between the easily peelable primer layer and the ink-repellent layer, or when an ink-repellent layer is continuously present on the outer side of the ink-repellent layer, continuous lines can be formed on the printing plate. Furthermore, by modifying the ink-repellent layer to have ink-receptivity through pattern irradiation with active energy lines, or by spraying an ink-receptivity forming composition in a pattern onto the ink-repellent layer and then curing it, continuous lines can be formed on the printing plate.

[0047] First, the original version of this invention will be described.

[0048] The original plate of this invention has an easily peelable primer layer and an ink-repellent layer sequentially and continuously formed on the outer peripheral surface of a cylindrical support. Here, "continuous" means that the easily peelable primer layer and the ink-repellent layer are arranged without gaps in the circumferential or axial direction in the original plate. As described above, by having the easily peelable primer layer, the ink-repellent layer, and other functional layers continuously present in the circumferential or axial direction of the original plate, it is possible to form discontinuous or continuous patterns on the printing plate, thus enabling seamless printing of discontinuous or continuous patterns that are repeatedly formed on a long printing medium.

[0049] As the material constituting the cylindrical support, dimensionally stable metals or plastics are preferred. Examples include metals such as aluminum, iron, zinc, and copper, or alloys of these metals as the main component, as well as plastics such as epoxy resin, phenolic resin, ester resin, vinyl ester resin, amide resin, and imide resin, or fiber-reinforced plastics containing these plastics and fibers such as glass fiber, carbon fiber, aramid fiber, polyethylene fiber, Zylon fiber, and boron fiber. From the viewpoint of being lightweight and easy to handle, aluminum alloys or fiber-reinforced plastics are preferred.

[0050] From the viewpoint that printing can be performed immediately after the printing plate is manufactured from the original, the cylindrical support is preferably the printing plate cylinder of the printing press. In particular, the cylindrical support is a printing plate cylinder sleeve that can be attached and detached from the printing plate cylinder shaft, which is more preferable from the viewpoint that operations such as a series of processes before printing plate manufacturing or the regeneration of the cylindrical support after printing can be performed outside the printing press.

[0051] As for the dimensions of the cylindrical support, the appropriate diameter or width can be selected for the printing cylinder of the printing press used.

[0052] The easily peelable primer layer in this invention refers to a layer that can be peeled off into a film from the outer peripheral surface of a cylindrical support using a dry process, and is directly, adjacently, laminated on the outer peripheral surface of the cylindrical support. Because the easily peelable primer layer and the various functional layers disposed on its outer peripheral surface can be peeled off into a film from the outer peripheral surface of the cylindrical support using a dry process, the cylindrical support can be easily regenerated without the need for wet processes such as chemical cleaning or complex operations such as grinding the outer peripheral surface of the support.

[0053] The adhesion force between the original cylindrical support and the easily peelable primer layer is preferably 10 to 2000 N / m. By making the adhesion force 10 N / m or more, the printing plate can be stably maintained during printing, and the printability can be improved. The adhesion force is more preferably 30 N / m or more. On the other hand, by making the adhesion force 2000 N / m or less, the easily peelable primer layer is easier to peel off, and the cylindrical support can be more easily regenerated. The adhesion force is preferably 1000 N / m or less, more preferably 800 N / m or less.

[0054] As a method to achieve the adhesion within the stated range, examples include, for instance, the method of forming an easy-to-peel primer layer using an easy-to-peel primer layer forming composition described later.

[0055] The adhesion force between the cylindrical support and the easily peelable primer layer can be determined by measuring the force required to peel off a specified length of the easily peelable primer layer from the outer circumferential surface of the cylindrical support using a force gauge. Specifically, at a randomly selected location on the easily peelable primer layer located on the outer circumferential surface of the cylindrical support, a razor is used to make a 0.1m wide and 0.1m long strip. The force [N / 0.1m] required to peel off 0.05m of the easily peelable primer layer from the cylindrical support along its length is measured using a force gauge. By multiplying the obtained peeling force [N / 0.1m] by 10, the adhesion force [N / m] between the cylindrical support and the easily peelable primer layer can be determined.

[0056] In the original version of this invention, the adhesion force between the cylindrical support and the easily peelable primer layer is preferably less than the film strength of the easily peelable primer layer. By making the adhesion force between the cylindrical support and the easily peelable primer layer less than the film strength of the easily peelable primer layer, the peeling of the easily peelable primer layer becomes easier, and the cylindrical support can be regenerated more easily. More preferably, the film strength of the easily peelable primer layer is 1.5 times or more the adhesion force between the cylindrical support and the easily peelable primer layer.

[0057] As a method for ensuring that the relationship between the film strength of the easy-peel primer layer and the adhesion force between the cylindrical support and the easy-peel primer layer is within the specified range, examples include methods for ensuring that the average thickness of the easy-peel primer layer is within the preferred range described later, and methods for forming the easy-peel primer layer using the easy-peel primer layer forming composition described later.

[0058] The film strength of an easy-peel primer layer can be determined by measuring its tensile strength and average thickness. Specifically, the tensile strength of the easy-peel primer layer [N / mm] 2 The product of the average thickness [mm] of the easy-peel primer layer and the film strength [N / mm] of the easy-peel primer layer is the film strength [N / mm]. By making the film strength [N / mm] of the obtained easy-peel primer layer 1000 times and setting the unit to [N / m], it is easier to grasp the relationship between the two by making the unit consistent with the adhesion force [N / m] between the cylindrical support and the easy-peel primer layer.

[0059] The tensile strength of the easily peelable primer layer can be determined by the method specified in JIS K6251:2017.

[0060] Furthermore, the average thickness of the easily peelable primer layer can be determined by cross-sectional SEM or cross-sectional TEM observation. More specifically, after the easily peelable primer layer is peeled off from the original plate and resin is embedded in the film, the cross-section of the sample prepared by the ultrathin section method is observed under magnification using SEM or TEM. In the vertical cross-sectional image, the thickness of 10 randomly selected locations from the easily peelable primer layer is measured, and their mean values ​​are calculated, thereby determining the average thickness. Additionally, the thickness of the easily peelable primer layer does not change during the process of manufacturing the printing plate from the original plate; therefore, it can also be used instead of the original plate to determine the average thickness of the easily peelable primer layer from the printing plate in the same way.

[0061] The elongation at break of the original peelable primer layer of the present invention is preferably 10 to 1000%. By making the elongation at break 10% or more, the peelable primer layer is easier to peel off, and the cylindrical support can be regenerated more easily. The elongation at break is more preferably 20% or more. On the other hand, by making the elongation at break 1000% or less, the deformation of the release film is suppressed, the peelable primer layer is easier to peel off, and the cylindrical support can be regenerated more easily. The elongation at break is more preferably 800% or less.

[0062] As a method for achieving an elongation at break within the specified range for an easily peelable primer layer, examples include, for instance, a method for forming an easily peelable primer layer using an easily peelable primer layer forming composition described later.

[0063] The elongation at break of the easily peelable primer layer can be determined by the method specified in JIS K6251:2017.

[0064] The average thickness of the original peelable primer layer of the present invention is preferably 15 to 500 μm. By making the average thickness 15 μm or more, the peelable primer layer is easier to peel off, and the cylindrical support can be regenerated more easily. In addition, the film strength of the peelable primer layer can be appropriately improved. An average thickness of 20 μm or more is more preferred. On the other hand, by setting the average thickness to 500 μm or less, the drying efficiency of the peelable primer layer can be improved, and the residual stress or residual strain of the peelable primer layer after drying or curing can be reduced. An average thickness of 300 μm or less is more preferred. The average thickness of the peelable primer layer can be determined by the method described above.

[0065] The original version of this invention preferably includes a compound having a functional group with a cohesion energy of 20-60 kJ / mol in the easily peelable primer layer. By including this compound, the adhesion to the cylindrical support and film strength can be improved, and the desired range can be easily adjusted. Furthermore, it is preferable that the easily peelable primer layer does not have covalent bonds with the outer peripheral surface of the cylindrical support. The absence of covalent bonds appropriately suppresses the adhesion to the cylindrical support, allowing the easily peelable primer layer to be easily peeled from the outer peripheral surface of the cylindrical support into a film using a dry process. That is, the adhesion to the cylindrical support can be easily adjusted to the desired range.

[0066] Functional groups with condensation energies of 20–60 kJ / mol can include, for example, carboxyl groups (23.4 kJ / mol), hydroxyl groups (24.3 kJ / mol), isourea bonds (27.7 kJ / mol), urethane bonds (36.8 kJ / mol), urethane bonds (38.9 kJ / mol), urea bonds (41.8 kJ / mol), and biuret bonds (58.5 kJ / mol). Two or more of these can be present. Furthermore, the condensation energies mentioned are calculated based on values ​​used in the derivation method for solubility parameters based on molecular structure proposed by Fedors (RF Fedors, Polym. Eng. Sci., 14147 (1974)).

[0067] Polyurethane is preferred as a compound having a functional group with a cohesion energy of 20 to 60 kJ / mol. That is, the original version of this invention preferably contains polyurethane as the compound having the aforementioned functional group with a cohesion energy of 20 to 60 kJ / mol. Because polyurethane has urethane bonds with high cohesion energy in its molecule, it can improve the adhesion to the cylindrical support and the film strength, and can be easily adjusted to the preferred range. Furthermore, because it has soft segments such as polyether or polyester in its molecule, it can improve the elongation at break of the easily peelable primer layer, and can be easily adjusted to the preferred range. Among these, films with high tensile strength after drying are preferred, and examples include "Chrisbon" (registered trademark) 8966 and 9004 (both manufactured by DIC Corporation). Alternatively, polyurethane emulsions with high tensile strength can be used, formed by dispersing dried polyurethane particles in a dispersion medium such as water. Examples include the "Super Filter" (registered trademark) series (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), and more specifically, "Super Filter" 150 (tensile strength: 45 N / mm²). 2(e.g., Daiichi Kogyo Pharmaceutical Co., Ltd.). Polyurethane preferably has carboxyl or hydroxyl groups, which improves adhesion to the cylindrical support or film strength, and can be easily adjusted to the preferred range. Furthermore, it improves adhesion to layers on an easy-to-peel primer layer. Examples of hydroxyl-containing polyurethanes include, for example, the "Sunpressive" (registered trademark) IB series (manufactured by Sanyo Chemical Industry Co., Ltd.).

[0068] The easy-peel primer layer can contain inorganic particles. Since a tougher film can be obtained through the filling effect of inorganic particles, the easy-peel primer layer can be made into a thin film.

[0069] As inorganic particles, carbon black or silica particles are preferred, but from the viewpoint of inspection, silica particles are more preferred. Examples of silica particles include the "AEROSIL" (registered trademark) series (manufactured by AEROSIL Co., Ltd., Japan).

[0070] From the viewpoint of dispersibility, the average particle size of inorganic particles is preferably 0.1 to 2 μm, more preferably 0.2 to 1 μm.

[0071] Examples of ink-repellent layers for the original version of this invention include addition-reaction type, condensation-reaction type, and addition-condensation-reaction combined type silicone or fluoropolymer layers disclosed to date as ink-repellent layers for non-horizontal printing plates, as well as hydrophilic layers disclosed as ink-repellent layers for horizontal printing plates. Preferably, the ink-repellent layer for the original version of this invention is a silicone layer.

[0072] Examples of ink-repellent organosilicon layers that are addition reaction type, condensation reaction type, or a combination of addition and condensation reaction types include, for example, the layer exemplified as a layer containing two organosiloxane units in Japanese Patent Application Publication No. 2021-66175, the layer exemplified as an organosilicon rubber layer in International Publication No. 2019 / 203261, and the layer exemplified as a first organosilicon layer in International Publication No. 2019 / 203263.

[0073] To improve the adhesion between the easy-peel primer layer / ink-repellent layer and between the easy-peel primer layer / inking layer (described later), an adhesive layer can be continuously provided between the easy-peel primer layer / ink-repellent layer and between the easy-peel primer layer / inking layer. Here, "continuous" means that in the original, the adhesive layer is provided without gaps in the circumferential or axial direction.

[0074] As an adhesive layer, examples include layers described as insulation layers in Japanese Patent Application Publication No. 2004-199016, Japanese Patent Application Publication No. 2004-334025, and Japanese Patent Application Publication No. 2006-276385.

[0075] The average thickness of the adhesive layer is 0.1 μm or more, which is preferred from the perspective of improving the damage resistance and printability of the printing plate. In addition, it is preferred to be 30 μm or less from the perspective of easy evaporation of diluent solvent and excellent productivity. More preferably, it is 0.2 to 20 μm.

[0076] As described above, since the original of the present invention can form continuous lines on the printing plate, it is preferable to have an ink layer continuously between the easily peelable primer layer and the ink-repellent layer or further outside the ink-repellent layer. Here, "continuously" means that the ink layer is provided without gaps in the circumferential or axial direction in the original.

[0077] As the original form of this invention, the following can be listed:

[0078] (1) The cylindrical support body has a continuous, easily peelable primer layer and an ink-repellent layer on its outer peripheral surface.

[0079] (2) The cylindrical support body has a continuous, easily peelable primer layer, an ink-repellent layer, and an ink-adhesive layer on its outer peripheral surface.

[0080] (3) The cylindrical support body has a continuous, easily peelable primer layer, an ink layer, and an ink-repellent layer on its outer peripheral surface; etc.

[0081] In embodiment (2), the ink-repellent layer can be, for example, an ink-repellent silicone layer exemplified as the second silicone layer in International Publication No. 2019 / 203263. Alternatively, in another embodiment (2), the ink-repellent layer can be a hydrophilic layer disclosed to date as an ink-repellent layer for water-based lithographic printing plates, and the ink-repellent layer can be an ink-repellent layer disclosed to date as a photosensitive layer or a heat-sensitive layer for water-based lithographic printing plates.

[0082] In the form of (3), as the ink layer, the ink layer disclosed so far as a photosensitive layer or a thermal layer for use in horizontal printing plates can be used.

[0083] Next, the manufacturing method of the original plate will be described. The original plate of the present invention is obtained by sequentially and seamlessly providing an easily peelable primer layer and an ink-repellent layer in the circumferential or axial direction on the outer peripheral surface of a cylindrical support. As the cylindrical support, a support regenerated by the cylindrical support regeneration method of the present invention, described later, is preferred. That is, in one embodiment of the manufacturing method of the original plate of the present invention, a continuous easily peelable primer layer and an ink-repellent layer are sequentially formed on the outer peripheral surface of the cylindrical support regenerated by the cylindrical support regeneration method of the present invention.

[0084] As a method for forming an easily peelable primer layer, examples include continuously coating the easily peelable primer layer forming composition (described later) onto the outer peripheral surface of a cylindrical support and drying it under heating or without heating. To promote drying, it is preferable to use a known hot air drying apparatus or an infrared drying apparatus, heating at a temperature of 50 to 180°C for 30 seconds to 10 minutes. That is, one way to manufacture the original version of the present invention is to form the easily peelable primer layer by coating the easily peelable primer layer forming composition onto the outer peripheral surface of a cylindrical support and drying it under heating or without heating. As a cylindrical support, it is preferable to use a support regenerated by the cylindrical support regeneration method of the present invention (described later). In addition, as another method for forming an easily peelable primer layer, examples include continuously coating the easily peelable primer layer forming composition (described later) onto the outer peripheral surface of a cylindrical support and curing the easily peelable primer layer forming composition by irradiating it with active energy rays. That is, one method of manufacturing the original version of the present invention is a method for manufacturing the original version of the present invention, wherein an easy-to-peel primer layer forming composition is coated on the outer peripheral surface of a cylindrical support, and the easy-to-peel primer layer forming composition is cured by irradiation with active energy rays to form the easy-to-peel primer layer. As the cylindrical support, it is preferable to use a support regenerated by the cylindrical support regeneration method of the present invention described later. Examples of active energy rays include visible light, ultraviolet (UV), electron beams (EB), X-rays, and particle beams. Considering the ease of operation of the beam source, ultraviolet light is preferred. Examples of active energy irradiation devices include high-pressure mercury lamps, xenon lamps, and metal halide lamps. It is preferable to use ultraviolet irradiation devices such as LED-UV.

[0085] Examples of methods for forming an ink-repellent layer include, for instance, continuously applying the ink-repellent layer forming composition (described later) to the outer peripheral surface of an easily peelable primer layer and then drying / curing it under heating or without heating. To promote drying and curing, it is preferable to heat at a temperature of 50–180°C for 30 seconds to 10 minutes.

[0086] As another method for sequentially applying a peelable primer layer and an ink-repellent layer to the outer peripheral surface of a cylindrical support, examples include, for instance, continuously coating the outer peripheral surface of the cylindrical support with the peelable primer layer forming composition described later, and then continuously coating the outer peripheral surface with the ink-repellent layer forming composition described later, followed by any of the following methods:

[0087] <1> A method for curing an easily peelable primer layer by irradiating the composition with active energy rays, followed by drying / curing the composition under heating or non-heating conditions.

[0088] <2> A method for curing an easily peelable primer layer composition by irradiating it with active energy rays from the ink-repellent layer side after drying / curing the composition under heating or non-heating conditions.

[0089] <3> Simultaneously performing: curing the composition for forming an easily peelable primer layer by irradiating it with active energy rays from the ink-repellent layer side, and drying / curing the composition for forming the ink-repellent layer under heating or non-heating conditions.

[0090] etc.

[0091] In each of the methods 1 to <3>, in order to promote the drying or curing of the composition for forming the ink-repellent layer after coating, it is preferable to heat at a temperature of 50 to 180°C for 30 seconds to 10 minutes.

[0092] Examples of coating methods for compositions for forming easily peelable primer layers and compositions for forming ink-repellent layers include, for example, immersion coating, spraying, and cylindrical slot die coating.

[0093] Depending on the requirements, when continuously forming an adhesive layer or ink layer, the coating method can include, for example, dipping, spraying, or slot die coating. Furthermore, to promote drying, it is preferable to use a known hot air drying device or infrared drying device, heating at a temperature of 50–180°C for 30 seconds to 10 minutes.

[0094] Next, the composition for forming an easy-peel primer layer and the composition for forming an ink-repellent layer preferably used in the form described in (1) will be explained. The composition for forming an easy-peel primer layer in this invention refers to a composition for forming an easy-peel primer layer, and similarly, the composition for forming an ink-repellent layer in this invention refers to a composition for forming an ink-repellent layer.

[0095] The composition for forming an easily peelable primer layer preferably contains a compound having a functional group having a cohesion energy of 20 to 60 kJ / mol. Examples of functional groups having a cohesion energy of 20 to 60 kJ / mol include carboxyl groups, hydroxyl groups, isourea bonds, urethane bonds, urethane bonds, urea bonds, and biuret bonds.

[0096] Examples of compositions for forming easily peelable primer layers include: (a) those containing a tensile strength of 25 N / mm². 2 The above-mentioned high tensile strength polymer and solvent composition for forming an easy-peel primer layer, (b) contains a tensile strength of less than 25 N / mm. 2 (c) Compositions for forming easy-peel primer layers using polymers, inorganic particles, and solvents with low tensile strength; and so on.

[0097] As a compound having a functional group with a cohesion energy of 20 to 60 kJ / mol in the form described in (a), polyurethane is preferred, and compounds exemplified as high-tensile-strength polyurethanes in the description of easy-peel primer layers can be cited.

[0098] As a compound having a functional group with a cohesion energy of 20-60 kJ / mol in the form described in (b), polyurethane is preferred. However, due to the filler effect of inorganic particles, the tensile strength of the film after drying is increased, so the tensile strength of the polyurethane film itself after drying may not necessarily be high. Furthermore, polyurethane preferably has carboxyl or hydroxyl groups, which can improve the adhesion to the cylindrical support or the film strength, and can be easily adjusted to the preferred range. Additionally, it can improve the adhesion to the layer on the easy-peel primer layer. Examples of polyurethanes containing hydroxyl groups include those exemplified in the description of easy-peel primer layers.

[0099] As inorganic particles, carbon black or silica particles are preferred, and from the viewpoint of print quality, silica particles are more preferred. Examples of silica particles include those exemplified in the description of easy-to-peel primer layers.

[0100] In the configurations described in (a) or (b), solvents capable of dissolving polyurethane are preferred, and examples include, for instance, N,N-dimethylformamide, N,N-dimethylacetamide, cyclohexanone, cyclopentanone, γ-butyrolactone, tetrahydrofuran, 2-butanone, ethyl acetate, 2-propanol, toluene, etc. Two or more of these may be present. From the viewpoint of the leveling properties of the coating liquid, the boiling point of the solvent at 1 atmosphere is preferably 50°C or higher, more preferably 70°C or higher. On the other hand, from the viewpoint of quick-drying properties, the boiling point of the solvent at 1 atmosphere is preferably 160°C or lower, more preferably 140°C or lower.

[0101] Compounds having functional groups with a cohesion energy of 20–60 kJ / mol in the form described in (c) can include compounds with urethane bonds and olefinic unsaturated double bonds in their molecules, and compounds with hydroxyl groups and olefinic unsaturated double bonds in their molecules. Two or more of these may be present. From the viewpoint of high-speed curing, an acryloyl group is preferred as the olefinic unsaturated double bond.

[0102] As compounds containing both urethane bonds and acryloyl groups in their molecules, urethane acrylates can be listed as examples. Commercially available urethane acrylates include the "Uretan's Crypt" Ebeclet series, KRM series (all manufactured by Diesel Ornex Co., Ltd.), "Luccidia" series (manufactured by DIC Co., Ltd.), "NK Origo" U series, UA series (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), "Uretan's Crypt" AH series, UA series, UF series (all manufactured by Kyoeisha Chemical Co., Ltd.), and "Shiko" series (manufactured by Mitsubishi Kemikal Co., Ltd.), etc. These can contain two or more of these compounds. Among them, the cured films exhibiting rubber elasticity include "Urethana Crill" UF3999-BA, -AM, -HX (all manufactured by Kyoei Chemical Co., Ltd.), and "Ziguang" (registered trademark) UV-2000B, -3000B, -3200B, 3300B-, -3500B, -3500BA, -3520EA, -3700B (all manufactured by Mitsubishi Chemical Co., Ltd.), etc., which are low-urethane acrylates. Polymers are preferred, especially in terms of their ability to suppress the burden on human health and the environment. Solvent-free types that do not contain volatile solvents, such as "Uretan's Crill" UF3999-AM and -HX (all manufactured by Kyoei Chemical Co., Ltd.), and "Shiko" (registered trademark) UV-2000B, -3000B, -3200B, -3300B, and -3700B (all manufactured by Mitsubishi Kemica Co., Ltd.), are even more preferred.

[0103] In addition, examples of compounds containing hydroxyl and acryloyl groups in their molecules include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 1,4-cyclohexanediol monoacrylate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, 2-hydroxy-3-methacryloylpropyl acrylate, pentaerythritol triacrylate, terminal hydroxyl polyalkylene glycol monoacrylates such as "Brenmar" AE-90U, -200, and -400 (all manufactured by Nippon Oil Co., Ltd.), and terminal hydroxyl polypropylene glycol monoacrylates such as "Brenmar" (registered trademark) AP-200, -400, -400D, -550, -800, and -1000D (all manufactured by Nippon Oil Co., Ltd.). These may contain two or more of these groups.

[0104] For the purpose of improving the physical properties of the cured film, in addition to the aforementioned urethane acrylates or acrylates containing hydroxyl groups in the molecule, other acrylate monomers or oligomers may also be used. For example, to improve tensile strength, the use of 3- to 6-functional acrylate monomers or oligomers is effective; in addition, to improve elongation at break, the use of 1- to 2-functional acrylates of polyethylene glycol or polypropylene glycol is effective.

[0105] Furthermore, the photocurable easy-peel primer layer forming composition in (c) preferably contains conventionally known photoradical generators (sometimes also called polymerization initiators), such as organohalides, carbonyl compounds, organic peroxides, azo compounds, azido compounds, metallocene compounds, hexaaryldiimidazole compounds, organoboron compounds, disulfone compounds, oxime ester compounds, and onium salt compounds. By containing photoradical generators, the coated easy-peel primer layer forming composition can be instantaneously cured by irradiating it with active energy rays.

[0106] Examples of ink-repellent silicone layer-forming compositions include, for instance, the composition illustrated in Japanese Patent Application Publication No. 2021-66175 as a layer-forming composition containing two organosiloxane units, the composition illustrated in International Publication No. 2019 / 203261 as a silicone rubber layer-forming composition, and the composition illustrated in International Publication No. 2019 / 203263 as a first silicone layer-forming composition, which are addition reaction type, condensation reaction type, and addition-condensation reaction combined type ink-repellent silicone layer-forming compositions.

[0107] Next, the composition for forming an easy-to-peel primer layer, the composition for forming an ink-repellent layer, and the composition for forming an ink-adhesive layer, which are preferably used in the form of (2), will be described.

[0108] As compositions for forming an easy-to-peel primer layer and compositions for forming an ink-repellent layer, the compositions exemplified in form (1) can be used respectively. As a composition for forming an ink-adhesive silicone layer, the composition for forming an ink-adhesive silicone layer described in International Publication No. 2019 / 203263 can be used.

[0109] In addition, as another form of (2), as a composition for forming an ink-repellent layer, a known composition for forming a hydrophilic layer disclosed to date as a hydrophilic layer for use in a horizontal printing plate is used. In addition, as a composition for forming an ink-adhesive layer, a known composition for forming a photosensitive layer or a composition for forming a heat-sensitive layer disclosed to date as a photosensitive layer or a heat-sensitive layer for use in a horizontal printing plate can be used.

[0110] Next, the composition for forming an easy-to-peel primer layer, the composition for forming an ink layer, and the composition for forming an ink-repellent layer, which are preferably used in the form described in (3), will be explained.

[0111] As compositions for forming an easily peelable primer layer and compositions for forming an ink-repellent layer, the compositions exemplified in the form of (1) can be listed respectively. As compositions for forming an ink-adhesive layer, compositions for forming a photosensitive layer or compositions for forming a thermally sensitive layer disclosed to date as photosensitive layers or thermally sensitive layers for use in horizontal printing plates can be used.

[0112] Next, the method for manufacturing the printing plate will be described. The printing plate of the present invention is obtained by making a plate from the original plate of the present invention. Taking an original plate having a continuous peelable primer layer and an ink-repellent silicone layer on the outer peripheral surface of a cylindrical support as an example, the method can be used to manufacture the printing plate, for example, by the following two methods.

[0113] As a first manufacturing method, the method described in International Publication No. 2019 / 203261 can be cited. Specifically, it is a method of spraying a composition for forming ink portions in a pattern onto a primary ink-repellent silicone layer and then curing it.

[0114] As a second manufacturing method, the method described in Japanese Patent Application Publication No. 2021-66175 can be cited. Specifically, it is a method of changing the irradiated part to ink-repellent by irradiating the original ink-repellent silicone layer pattern with active energy rays.

[0115] As a method for manufacturing a printing plate from a master plate having a continuous, easily peelable primer layer, an ink-repellent silicone layer, and an ink-adhesive silicone layer on the outer peripheral surface of a cylindrical support, the method described in International Publication No. 2019 / 203263 can be cited as an example. Specifically, it is a method of irradiating the pattern from the ink-adhesive silicone layer side of the master plate using a high-output laser, thereby exposing the ink-repellent silicone layer by ablating the ink-adhesive silicone layer of the irradiated area.

[0116] As a method for manufacturing a printing plate from a master plate having a continuous, easily peelable primer layer, a hydrophilic layer, a photosensitive layer, or a thermosensitive layer on the outer peripheral surface of a cylindrical support, one example is to expose the pattern from the photosensitive layer or thermosensitive layer side and develop it using water or a liquid or developer with water as the main component.

[0117] As a method for manufacturing a printing plate from a master plate having a continuous, easily peelable primer layer, a photosensitive layer or a heat-sensitive layer, and an ink-repellent silicone layer on the outer peripheral surface of a cylindrical support body, one example is a method of exposing the pattern from the ink-repellent silicone layer side and developing it using water or a liquid or developer with water as the main component.

[0118] Next, the manufacturing method of seamless printed materials will be explained.

[0119] As a method for manufacturing seamless printed materials, the aforementioned printing plate, ink, and printing medium are preferably used. Furthermore, when the printing plate is a wet lithographic plate, the aforementioned printing plate, wetting water, ink, and printing medium are preferably used. Specifically, the method preferably includes a step of applying ink to the surface of the inked portion of the printing plate, and a step of transferring the ink adhering to the surface of the inked portion directly or via a blanket onto the printing medium.

[0120] Figure 2 This is a schematic cross-sectional view illustrating one method of manufacturing seamless printed material. The following description uses a blanket roller 8, but the invention is not limited to this; ink can also be applied directly to the printing medium 9 from the ink roller 5 after being applied to the inking surface of the seamless lithographic printing plate 7 without using the blanket roller 8. Furthermore, the following description describes an example of supplying ink from above the printing medium 9, but ink can also be supplied from below the printing medium 9.

[0121] First, ink is supplied to the ink roller 5. The ink supplied to the ink roller 5 adheres to the inking portion of the seamless lithographic printing plate 7 at the contact point with the plate. The ink adhering to the surface of the inking portion of the seamless lithographic printing plate 7 is transferred to the surface of the blanket cylinder 8 at the contact point with the blanket cylinder 8. The ink adhering to the blanket cylinder 8 is transferred to the printing medium 9 disposed on the impression cylinder 10 at the contact point with the medium. The printing medium 9 after ink transfer is dried as needed to obtain the printed material. Alternatively, if the printing plate is a wet lithographic printing plate, wetting water is supplied to the wetting roller 6 before supplying ink to the ink roller 5. The wetting water supplied to the wetting roller 6 adheres to the surface of the ink-repellent portion (exposed hydrophilic layer portion) of the seamless lithographic printing plate 7 at the contact point with the plate. The method after supplying ink to the ink roller 5 is the same as the method described above. The rotation speeds of ink roller 5, wet water roller 6, seamless offset printing plate 7, blanket roller 8, and impression roller 10 are not particularly limited and can be appropriately set according to the required quality of the printed material and the properties of the ink.

[0122] As for printing presses used in the manufacture of seamless printed materials, known direct printing presses or offset printing presses can be cited, but from the viewpoint of obtaining more printed materials by suppressing damage to the printing plate during printing, offset printing presses are preferred. An offset printing press consists of a paper feeding section, a printing section, and a transport section. The printing section includes at least an ink supply section, a plate cylinder, a blanket cylinder, and an impression cylinder.

[0123] From the viewpoint of improving resistance to media contamination, offset printing presses with cooling mechanisms on the oscillating rollers and / or printing cylinders are preferred.

[0124] When printing with oil-soluble or water-soluble oxidative polymeric inks, the ink transferred to the printing medium can be dried and / or cured by natural drying or heat treatment to obtain the printed material.

[0125] On the other hand, when printing with oil-soluble or water-soluble active energy ray curable inks, the ink transferred to the printing medium is instantly cured by active energy rays from the active energy ray irradiation device to obtain the printed material, which is therefore preferred.

[0126] As active energy rays, visible light, ultraviolet (UV), electron (EB), X-rays, and particle rays can be listed, but considering the ease of operation of the ray source, ultraviolet or electron rays are preferred.

[0127] When using ultraviolet light for curing, it is preferable to use ultraviolet irradiation devices such as high-pressure mercury lamps, xenon lamps, metal halide lamps, or LEDs. For example, when using metal halide lamps, from a production perspective, it is preferable to use lamps with an ultraviolet irradiation capacity of 80–150 W / cm². 2 The lamps with illuminance are used for curing at a conveyor speed ranging from 50 to 150 m / min. In particular, when using plastic film or metal-containing printing media as the printing medium, since the printing medium is prone to expansion and contraction due to the heat generated by the active energy rays, it is preferable to use an electron beam or LED ultraviolet irradiation device (LED-UV) that generates less heat.

[0128] When curing the material with electron beams, it is preferable to use an electron beam irradiation device with energy rays of 100 to 500 eV.

[0129] Examples of inks that can be preferably used in the present invention include those described below, but are not limited thereto.

[0130] <Ink-1> Oil-soluble oxidative polymerization ink

[0131] Examples of oil-soluble oxidative polymerization inks include those disclosed in Japanese Patent Application Publication Nos. 48-004107 and 01-306482, which are known to be washable with oil-based cleaning solutions. Additionally, oil-soluble oxidative polymerization inks, such as soybean oil inks, vegetable oil inks, and environmentally friendly low-load inks (also known as Non-VOC inks), are also included in this category. These inks are produced by replacing the solvent component with a vegetable oil component, as disclosed in Japanese Patent Application Publication Nos. 2005-336301, 2005-126579, 2011-144295, and 2012-224823.

[0132] <Ink-2> Water-soluble oxidative polymerization ink

[0133] As water-soluble oxidative polymeric inks, examples include known water-soluble oxidative polymeric inks that can be cleaned with water or water-based cleaning solutions, as disclosed in Japanese Patent Application Publication No. 2009-57461 and Japanese Patent No. 4522094.

[0134] <Ink-3> Oil-soluble active energy X-ray curable ink

[0135] As oil-soluble active energy ray-curable inks, examples include known active energy ray-curable inks that can be cleaned with oil-based cleaning solutions, as disclosed in Japanese Patent No. 5158274 and Japanese Patent Application Publication No. 2012-211230. Furthermore, active energy ray-curable inks also include high-sensitivity UV inks for energy-saving (lamp-reduced) UV printing or LED-UV printing.

[0136] <Ink-4> Water-soluble active energy radiation curable ink

[0137] As water-soluble active energy ray-curable inks, examples include known water-soluble active energy ray-curable inks that can be cleaned with water or water-based cleaning solutions, as disclosed in Japanese Patent Application Publication No. 2017-52817, International Publication No. 2017 / 047817, and International Publication No. 2017 / 090663.

[0138] In the aforementioned inks, oil-soluble or water-soluble active energy ray-curing inks are instantly cured upon transfer to the printing medium by irradiation with active energy rays. Therefore, they possess an advantage not found in conventional oxidative polymerization inks, allowing for immediate back-side printing or post-processing, and are thus preferred. However, unlike conventional oxidative polymerization inks, active energy ray-curing inks do not contain or contain only trace amounts of anti-contamination components, thus having the disadvantage of easily causing contamination during printing. Since the printing plate of the present invention has high ink repellency, both oil-soluble and water-soluble active energy ray-curing inks can be used effectively. Furthermore, when cleaning ink adhering to various rollers, blankets, printing plates, etc., of the printing press, the use of highly volatile and harmful organic solvents in oil-soluble inks such as oil-soluble oxidative polymerization inks or oil-soluble active energy ray-curing inks places a heavy burden on human health and the environment. In contrast, water-soluble inks, such as water-soluble oxidative polymerization inks or water-soluble active energy radiation-cured inks, can be cleaned with water alone or with a water-based cleaning solution. Therefore, they do not require the use of highly volatile and harmful organic solvents, which is preferable from the perspective of significantly reducing the burden on human health and the environment. In particular, water-soluble active energy radiation-cured inks are more suitable for use.

[0139] As printing media, examples include: high-grade paper, coated paper, coated paper, cast-coated paper, synthetic paper, newspaper paper, etc.; metals such as aluminum or aluminum alloy, iron, steel, zinc, copper, etc.; plastic films such as polyethylene terephthalate, polyethylene, polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.; or composites of these paper, metal, and plastic films (paper or plastic film with vapor-deposited or laminated metal, paper or metal with laminated plastic film, metal or plastic film with laminated paper), etc., but not limited to these.

[0140] In the seamless printing method of the present invention, the printing surface is composed of a metal or plastic film. Synthetic paper, metal, plastic film, paper with vapor deposited or laminated metal or plastic film are suitable for printing on a printing medium with non-absorbent ink components, such as paper with laminated plastic film or metal.

[0141] In the above, the printing surface is made of plastic film. From the point of view of improving adhesion, the printing surface of the printing medium, such as synthetic paper, plastic film, paper laminated with plastic film, or metal, can be treated with surface treatments such as primer resin coating, corona discharge treatment, and plasma treatment.

[0142] As for the shape of the printing medium, a long, roller-shaped printing medium is preferred. By using the printing plate of the present invention and the long, roller-shaped printing medium, printing can be performed by roller-to-roll method, enabling the mass production of high-precision seamless printed materials with no seams on the pattern.

[0143] The thickness of the ink coating (ink-cured film) on the printing medium is preferably 0.1 to 50 μm. By keeping the thickness of the ink coating within this range, it is possible to reduce ink costs while maintaining good print quality.

[0144] Next, the method for reproducing the cylindrical support from the original or printed plate will be explained.

[0145] Since the original or printing plate of the present invention continuously has an easily peelable primer layer adjacent to the outer peripheral surface of the cylindrical support, the cylindrical support can be easily regenerated simply by peeling the easily peelable primer layer and each functional layer disposed on its outer peripheral surface together into a film using a dry process. This eliminates the need for complex operations such as wet treatments involving chemical cleaning or grinding of the outer peripheral surface of the cylindrical support. In other words, the method for regenerating the cylindrical support of the present invention involves peeling the easily peelable primer layer into a film from the outer peripheral surface of the cylindrical support of the original or printing plate of the present invention using a dry process.

[0146] By repeatedly applying an easy-to-peel primer layer, an ink-repellent layer, and other functional layers to the outer surface of a regenerated cylindrical support through a dry process of peeling off the easy-to-peel primer layer and the various functional layers disposed on its outer surface into a film, the original can be repeatedly manufactured. Since the cylindrical support can be reused, it is extremely economical.

[0147] Next, the composition for forming an easy-to-peel primer layer according to the present invention will be described. The definition of the composition for forming an easy-to-peel primer layer is as described above. The composition for forming an easy-to-peel primer layer according to the present invention comprises a compound having a functional group having a cohesion energy of 20 to 60 kJ / mol. As a compound having a functional group having a cohesion energy of 20 to 60 kJ / mol, a compound having a urethane bond and / or hydroxyl group is preferred, and a polyurethane is more preferred. Furthermore, as a compound having a functional group having a cohesion energy of 20 to 60 kJ / mol, a compound having an olefinic unsaturated double bond is preferred, and a urethane acrylate is more preferred.

[0148] The composition for forming an easily peelable primer layer of the present invention preferably further contains inorganic particles.

[0149] Examples of compositions for forming an easy-peel primer layer according to the present invention include compositions that are preferably used in the manufacturing method of the original.

[0150] Example

[0151] The present invention will now be described in more detail through examples.

[0152] The evaluation of each embodiment and comparative example was carried out using the following methods.

[0153] <Evaluation methods in each embodiment and comparative example>

[0154] (1) Evaluation of the primer layer

[0155] (1-1) Ease of regeneration of printing plate cylinder sleeve (ease of peeling of primer layer)

[0156] For the original plates produced in each embodiment and comparative example, an easily peelable primer layer was peeled off from the outer peripheral surface of the plate cylinder sleeve using a dry process to evaluate the regeneration ease of the plate cylinder sleeve. The regeneration ease scores for the printing plate cylinder sleeve are as follows.

[0157] A: Recycling of the printing plate cylinder sleeve is very easy (the easy-to-peel primer layer can be easily peeled off in a film-like manner using a dry process).

[0158] B: The printing plate cylinder sleeve is easy to regenerate (the easy-peel primer layer can be peeled off through a dry process, but the easy-peel primer layer breaks during the peeling process).

[0159] C: The printing plate cylinder sleeve cannot be recycled (the underlying layer cannot be peeled off by a dry process).

[0160] (1-2) Adhesion between the printing plate cylinder sleeve and the easily peelable primer layer

[0161] In each embodiment and comparative example, at a randomly selected location in the easily peelable primer layer formed on the outer peripheral surface of the printing plate cylinder sleeve, a razor was used to cut into a strip with a width of 0.1m and a length of 0.1m. A digital force gauge, ZTA-500N (manufactured by Imada Corporation), was used to measure the force [N / 0.1m] when the easily peelable primer layer was peeled off from the printing plate cylinder sleeve along the length direction by 0.05m. The obtained peeling force [N / 0.1m] was multiplied by 10 to calculate the adhesion force [N / m] between the printing plate cylinder sleeve and the easily peelable primer layer.

[0162] (1-3) Film strength of easily peelable primer layer

[0163] The tensile strength [N / mm] of the easily peelable primer layer obtained by the method described below (1-3-1) 2 The film strength [N / mm] of the easy-peel primer layer is calculated by multiplying the film strength [N / mm] by the average thickness [mm] of the easy-peel primer layer obtained by the method described below (1-3-2). To easily grasp the relationship between the adhesion force between the printing cylinder sleeve and the easy-peel primer layer, the film strength [N / mm] of the easy-peel primer layer is multiplied by 1000, so that the unit is [N / m].

[0164] (1-3-1) Tensile strength of easily peelable primer layer

[0165] In (1-1), the tensile strength of the easily peelable primer layer, which was peeled off from the printing cylinder sleeve, was determined using the method specified in JIS K6251:2017. The tensile testing machine, "Tensilon" (registered trademark) RTF-1350 (manufactured by A. Ande Co., Ltd.), was used, and an air compressor was used for sample clamping.

[0166] (1-3-2) Average thickness of easily peelable primer layer

[0167] In (1-1), after embedding resin in the easily peelable primer layer peeled from the printing cylinder sleeve, the cross-section of the sample prepared by the ultrathin sectioning method was observed under magnification using a scanning electron microscope: SU3900 (manufactured by Hitachi Hitec Co., Ltd.). In the vertical cross-sectional image, the thickness of 10 randomly selected locations from the easily peelable primer layer was measured, and the average value was calculated to determine the average thickness of the easily peelable primer layer.

[0168] (1-4) Elongation at break of easily peelable primer layer

[0169] In (1-1), the elongation at break of the easily peelable primer layer, which was peeled off from the printing cylinder sleeve, was determined by the method specified in JIS K6251:2017. In the determination, a tensile testing machine, "Tensilon" (registered trademark) RTF-1350, was used, and an air compressor was used to clamp the sample.

[0170] (2) Printing Evaluation

[0171] The printing plates obtained by the methods described in the various embodiments and comparative examples are mounted on the printing cylinder shaft of an EB offset printing press: OFFSETCI / 8 (manufactured by COMEXI Corporation), and printing is performed for a maximum of 100,000 m under the printing conditions shown below.

[0172] <Printing Conditions>

[0173] Ink roller: #8000 (manufactured by Meiwa Rubber Industry Co., Ltd.)

[0174] Cylindrical rubber blanket: manufactured by EPDM Blanccot Co., Ltd. (Kinyo Co., Ltd.)

[0175] Water-soluble EB ink: Offset EB ink, type F, FE1908, 4-color process (manufactured by Samsung Inki Co., Ltd.)

[0176] Wetting water: Purified water (used only in Example 16, which uses a seamless horizontal printing plate).

[0177] The ink component is non-absorbent printed medium: "Enbret" (registered trademark) PTM-12 (roller biaxial stretch PET film, thickness: 12μm, printing surface: easy-adhesive treatment, manufactured by Unichika Co., Ltd.)

[0178] Page temperature: 25~28℃

[0179] Printing speed: 100m / minute

[0180] <Ink Curing Conditions>

[0181] EB radiation dose: 40 kGy

[0182] EB irradiation atmosphere: in a nitrogen atmosphere.

[0183] (2-1) Can it be printed seamlessly?

[0184] Visually inspect the printed material to evaluate whether seamless printing of discontinuous and continuous patterns is feasible. The scoring for seamless printing feasibility is as follows.

[0185] A: Seamless printing is possible (the printed material has not been confirmed to have pattern seams).

[0186] B: Seamless printing is not possible (confirm that there are pattern seams on the printed material).

[0187] (2-2) Image reproducibility

[0188] Approximately 5000 meters of printed material was cut from the printing press and placed on five overlapping sheets of OK "Top Coat" (registered trademark). The halftone dots were then observed under magnification using a 50x magnifying glass. The image reproducibility was rated as follows.

[0189] A: Reproduces 1-99% of dots in AM screening at 175 lpi (resolution: 2400 dpi).

[0190] (2-3) Printability

[0191] Printability is evaluated by the maximum print length [m] at which good print quality is achieved, up to a maximum of 100,000 m. Additionally, the brackets in the printability column of Table 1 indicate the following:

[0192] (P): Printing limit due to peeling of the primer layer (P layer).

[0193] (S): Printing limit due to peeling of the silicone layer (S layer).

[0194] (F): Printing limits caused by damage to the silicone filling between the header and footer of the printing plate.

[0195] [Example 1]

[0196] On the outer circumferential surface of an aluminum alloy printing plate cylinder sleeve, the following easy-peel primer layer forming composition-1 is applied using a cylindrical slot die coater (manufactured by Higashi Reigenia Ling Co., Ltd.), and heated at 170°C for 10 minutes, thereby setting a continuous easy-peel primer layer with an average thickness of 25 μm.

[0197] <Composition for forming an easy-to-peel primer layer-1>

[0198] Add the following components (a-1) and (b-1) to a container and stir until the components are homogeneous to obtain composition-1 for easy-peeling primer layer formation.

[0199] (a-1) Solvent: N,N-dimethylformamide (boiling point at 1 atm: 153℃): 500.0 parts by weight

[0200] (b-1) Polyurethane solution: “Chrisbon” (registered trademark) 9004 (solid content concentration: 20% by mass, solvent: N,N-dimethylformamide / 2-butanone (boiling point at 1 atm: 80°C), hydroxyl groups in polyurethane molecules: none, manufactured by DIC Co., Ltd.): 500.0 parts by mass.

[0201] Next, using a cylindrical slot die coater, the following ink-repellent silicone layer forming composition-1 is applied to the outer peripheral surface of the easily peelable primer layer, and heated at 150°C for 5 minutes to form a continuous ink-repellent silicone layer with an average thickness of 20 μm, thereby obtaining the original.

[0202] <Composition for Forming Ink-Repellent Organosilicon Layers-1>

[0203] Add components (a-2), (b-2), and (c-2) to a container and stir until homogeneous. Bubble the resulting solution with dry nitrogen for 20 minutes to remove moisture. Add component (d-2) to the resulting solution and stir for 10 minutes. Add component (e-2) just before coating and stir to obtain composition-1 for forming an ink-repellent silicone layer.

[0204] (a-2) Isoparaffin-based solvent: "Asect" (registered trademark) E (manufactured by Aescapac Co., Ltd.): 295.00 parts by mass

[0205] (b-2) Siloxane compounds with two or more vinyl groups within the molecule (dimethylvinylsiloxane-polydimethylsiloxane): DMS-V35 (manufactured by GELEST Inc., weight average molecular weight: 49,500, number of vinyl groups within the molecule: 2.0): 91.00 parts by weight

[0206] (c-2) Siloxane compounds with more than 3 SiH groups in the molecule (two-terminated trimethylsiloxy-methylhydrosiloxane-dimethylsiloxane copolymer): HMS-301 (prepared by GELEST Inc., weight average molecular weight: 1950, H group concentration derived from SiH groups: 0.41% by mass, number of SiH groups in the molecule: 8.0): 6.0 parts by mass

[0207] (d-2) Silane coupling agent and reaction inhibitor: Vinyltris(methylethylketoximino)silane: 3.0 parts by weight

[0208] (e-2) Reaction catalyst (platinum mixture): XC94-C4326 (made by Momentibu Platinum Mans Materia Medica Japan Cooperative Company, solid content concentration: 1% by mass): 5 parts by mass.

[0209] Using an F2 excimer laser drawing device (wavelength: 157 nm), the ink-repellent silicone layer of the original was exposed in a vacuum at an exposure dose of 300 mJ / cm². 2 Ultraviolet light is applied to create a printing plate from the original.

[0210] [Example 2]

[0211] Except that the easy-peel primer layer forming composition-1 is changed to the easy-peel primer layer forming composition-2 described below, the printing plate is obtained by the same method as in Example 1.

[0212] <Composition for forming easily peelable primer layer-2>

[0213] Add the following components (a-3) and (b-3) to a container and stir until the components are homogeneous to obtain composition-2 for easy-peeling primer layer formation.

[0214] (a-3) Solvent: N,N-dimethylformamide: 666.7 parts by weight

[0215] (b-3) Polyurethane solution: “Chrisbon” (registered trademark) 8966 (solid component concentration: 30% by mass, solvent: N,N-dimethylformamide, hydroxyl groups in polyurethane molecules: none, manufactured by DIC Co., Ltd.): 333.3 parts by mass.

[0216] [Example 3]

[0217] Except that the easy-peel primer layer forming composition-1 is changed to the easy-peel primer layer forming composition-3 described below, the printing plate is obtained by the same method as in Example 1.

[0218] <Composition for forming easily peelable primer layer-3>

[0219] Add the following components (a-4) and (b-4) to a container and stir until the components are homogeneous to obtain composition-3 for easy-peeling primer layer formation.

[0220] (a-4) Solvent: N,N-dimethylformamide: 600.0 parts by weight

[0221] (b-4) Polyurethane solution: “Sanprene” (registered trademark) LQ-T1333 (solid component concentration: 25% by mass, solvent N,N-dimethylformamide, hydroxyl groups in polyurethane: none, manufactured by Sanyo Chemical Industry Co., Ltd.): 400.0 parts by mass.

[0222] [Example 4]

[0223] Except for changing the average thickness of the easily peelable primer layer from 25 μm to 15 μm, the printing plate was obtained by the same method as in Example 3.

[0224] [Example 5]

[0225] Except for changing the average thickness of the easily peelable primer layer from 25 μm to 12 μm, the printing plate was obtained by the same method as in Example 3.

[0226] [Example 6]

[0227] Except that the easy-peel primer layer forming composition-1 is changed to the easy-peel primer layer forming composition-4 described below, the heating temperature is reduced from 170°C to 80°C, and the average thickness of the easy-peel primer layer is increased from 25 μm to 30 μm, the printing plate is obtained by the same method as in Example 1.

[0228] <Composition for forming easily peelable primer layer-4>

[0229] Add the following components (a-5) and (b-5) to a container and stir until the components are homogeneous to obtain composition-4 for easy-peeling primer layer formation.

[0230] (a-5) Solvent: 2-Butanone: 666.7 parts by weight

[0231] (b-5) Polyurethane solution: “Sanprene” (registered trademark) IB-1700D (solid component concentration: 30% by mass, solvent: 2-butanone / 2-propanol (boiling point at 1 atmosphere: 83°C) = 45 / 1 part by mass, hydroxyl groups in polyurethane molecules: present, manufactured by Sanyo Chemical Industry Co., Ltd.): 333.3 parts by mass.

[0232] [Example 7]

[0233] Except for changing the easy-peel primer layer forming composition-1 to the easy-peel primer layer forming composition-5 described below and changing the heating temperature from 170°C to 80°C, the printing plate was obtained by the same method as in Example 1.

[0234] <Composition for forming easily peelable primer layer-5>

[0235] In a sealable glass standard bottle filled with 1600.0 parts by weight of zirconia balls: "Toresselam" (registered trademark) crushing balls (φ1mm, manufactured by Toray Industries, Inc.), the following components (a-6), (b-6) and (c-6) were added and the bottle was sealed. Then, the bottle was placed on a small ball mill rotating stand (manufactured by Aswan Corporation) and dispersed at a rotation speed of 0.4 m / s for 7 days to obtain composition-5 for easy-to-peel primer layer formation.

[0236] (a-6) Solvent: 2-Butanone: 712.7 parts by weight

[0237] (b-6) Polyurethane solution: "Sunpresson" (registered trademark) IB-1700D: 233.3 parts by weight

[0238] (c-6) Inorganic particles: “AEROSIL” (registered trademark) RX200 (pyrolytic silica with trimethylsilyl surface modified, manufactured by AEROSIL Co., Ltd., Japan): 54.0 parts by weight.

[0239] [Example 8]

[0240] Except for changing the easy-peel primer layer forming composition-1 to the easy-peel primer layer forming composition-6 described below and changing the heating temperature from 170°C to 120°C, the printing plate was obtained by the same method as in Example 1.

[0241] <Composition for forming easily peelable primer layer-6>

[0242] Add the following components (a-7) and (b-7) to a container and stir until the components are homogeneous to obtain composition-6 for easy-peeling primer layer formation.

[0243] (a-7) Purified water (boiling point at 1 atmosphere: 100℃): 500.0 parts by weight

[0244] (b-7) Polyurethane aqueous dispersion: “Super Flox” (registered trademark) 150 (solid component concentration: 30% by mass, non-reactive, hydroxyl groups in polyurethane molecules: none, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.): 500.0 parts by mass.

[0245] [Example 9]

[0246] Except for changing the drying conditions of the easily peelable primer layer from heating at 170°C for 10 minutes to heating at 30°C for 3 hours, the printing plate was obtained by the same method as in Example 8.

[0247] [Example 10]

[0248] On the outer circumferential surface of the aluminum alloy printing plate cylinder sleeve, except that the following easy-peel primer layer forming composition-7 is applied using a cylindrical slot die coater, and cured by irradiating with ultraviolet light for 1 minute using an LED linear UV irradiator: UD90 (manufactured by Panasonic Debasis SUNX Co., Ltd., wavelength: 385nm), a continuous easy-peel primer layer with an average thickness of 25μm is formed, the printing plate is obtained using the same method as in Example 1.

[0249] <Composition for forming easily peelable primer layer-7>

[0250] Add the following components (a-8) and (b-8) to a container and stir until the components are homogeneous to obtain composition-7 for easy-peeling primer layer formation.

[0251] (a-8) Polyester-based urethane acrylate oligomer: UF-3999AM (acryloylmorpholine 30% by weight dilution, hydroxyl groups in polyester-based urethane acrylate oligomer molecule: none, manufactured by Kyoei Chemical Co., Ltd.): 960.0 parts by weight

[0252] (b-8) Photoradical generator: "Ilugaculia" (registered trademark) 184 (manufactured by BASF Japan Co., Ltd.): 40.0 parts by weight

[0253] [Example 11]

[0254] Except that the easy-peel primer layer forming composition-7 is changed to the easy-peel primer layer forming composition-8 described below, the printing plate is obtained by the same method as in Example 10.

[0255] <Composition for forming easily peelable primer layer-8>

[0256] Add the following components (a-9) and (b-9) to a container and stir until the components are homogeneous to obtain composition-8 for easy-peeling primer layer formation.

[0257] (a-9)NK Ester APG-700 (Polypropylene Glycol Diacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 660.0 parts by weight

[0258] (b-9) "Light Acrylate" (registered trademark) PE-3A (Pentaerythritol triacrylate, manufactured by Kyoei Chemical Co., Ltd.): 300.0 parts by weight

[0259] (c-9) Photoradical generator: "Ilugaculia" (registered trademark) 184 (manufactured by BASF Japan Co., Ltd.): 40.0 parts by weight

[0260] [Example 12]

[0261] Except for changing the average thickness of the easily peelable primer layer from 25 μm to 50 μm, the printing plate was obtained by the same method as in Example 1.

[0262] [Example 13]

[0263] Except that the ink-repellent silicone layer forming composition-1 is changed to the ink-repellent silicone layer forming composition-2 described below, the original version is obtained by the same method as in Example 1.

[0264] <Composition for Forming Ink-Repellent Organosilicon Layers-2>

[0265] Add components (a-10), (b-10), (c-10), and (d-10) to a container and stir until homogeneous. Bubble the resulting solution with dry nitrogen for 20 minutes to remove moisture. Add component (e-10) to the resulting solution and stir for 10 minutes. Add component (f-10) just before coating and stir to obtain composition-2 for forming an ink-repellent silicone layer.

[0266] (a-10) "Isoper" (registered trademark) E: 895.0 parts by weight

[0267] (b-10) Siloxane compounds with two or more vinyl groups within the molecule (two-terminated trimethylsiloxy-vinylmethylsiloxane-dimethylsiloxane copolymer): VDT-954 (manufactured by GELEST Inc., weight average molecular weight: 225,000, vinyl concentration: 4.29% by mass, number of vinyl groups in the molecule: 357.2): 62.0 parts by mass

[0268] (c-10) Liquids with a surface tension of less than 30 mN / m at 25°C: KF-96-50cs (dimethyl silicone oil, weight-average molecular weight: 3780, surface tension at 25°C: 20.8 mN / m, mass reduction rate after heating at 150°C for 24 hours under 1 atm: 0.1% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.): 20.0 parts by mass

[0269] (d-10) Siloxane compounds with more than 3 SiH groups in the molecule (two-terminated trimethylsiloxy-methylhydrosiloxane-dimethylsiloxane copolymer): HMS-064 (manufactured by GELEST Inc., weight average molecular weight: 55000, H group concentration from SiH groups: 0.08% by mass, number of SiH groups in the molecule: 44.4): 15.0 parts by mass

[0270] (e-10) Vinyltris(methylethylketoximino)silane: 3.0 parts by weight

[0271] (f-10)XC94-C4326:5.0 parts by weight.

[0272] Next, using a sub-femto inkjet processing device (SIJ Technoroji Co., Ltd.), the pattern of the ink-forming composition-1 described below is sprayed onto the ink-repellent silicone layer under the condition that the volume of the ejected droplets is 2 nanoliters, and heated at 150°C for 5 minutes to obtain a printing plate.

[0273] <Ink-forming composition-1>

[0274] Add components (a-11), (b-11), (c-11), and (d-11) to a container and stir until homogeneous. Bubble the resulting solution with dry nitrogen for 20 minutes to remove moisture. Add component (e-11) just before application and stir to obtain composition-1 for forming the ink layer.

[0275] (a-11) "Isoper" (registered trademark) C: 95.0 parts by weight

[0276] (b-11)VDT-954: 70.0 parts by weight

[0277] (c-11)HMS-993: 30.0 parts by weight

[0278] (d-11)2-Methyl-3-butyn-2-ol: 1.5 parts by weight

[0279] (e-11)XC94-C4326: 3.5 parts by weight.

[0280] [Example 14]

[0281] The easy-peel primer layer forming composition-1 is applied to the outer circumferential surface of the aluminum alloy printing plate cylinder sleeve using a cylindrical slot die coater and heated at 170°C for 10 minutes, thereby setting a continuous easy-peel primer layer with an average thickness of 25 μm.

[0282] Next, using a cylindrical slot coater, the following ink-repellent silicone layer forming composition-3 is coated on the outer peripheral surface of the easily peelable primer layer, and heated at 150°C for 5 minutes to form a continuous ink-repellent silicone layer with an average thickness of 20 μm.

[0283] <Composition for Forming Ink-Repellent Organosilicon Layers-3>

[0284] Add components (a-12), (b-12), and (c-12) to a container and stir until homogeneous. Bubble the resulting solution with dry nitrogen for 20 minutes to remove moisture. Add component (d-12) to the resulting solution and stir for 10 minutes. Just before coating, add component (e-12) and stir to obtain composition-3 for forming an ink-repellent silicone layer.

[0285] (a-12) "Isoper" (registered trademark) E: 895.0 parts by weight

[0286] (b-12)VDT-954: 82.0 parts by weight

[0287] (c-12) Siloxane compounds with more than 3 SiH groups in the molecule (two-terminated trimethylsiloxy-methylhydrosiloxane-dimethylsiloxane copolymer): HMS-064 (manufactured by GELEST Inc., weight average molecular weight: 55000, H group concentration from SiH groups: 0.08% by mass), number of SiH groups in the molecule: 44.4: 15.0 parts by mass

[0288] (d-12) Vinyltris(methylethyl ketone oxime)silane: 3.0 parts by weight

[0289] (e-12)XC94-C4326:5.0 parts by weight.

[0290] Next, the ink-repellent silicone layer outer peripheral surface is coated with the ink-adhesive silicone layer forming composition-1 using a cylindrical slot die coater, and heated at 150°C for 5 minutes to form a continuous ink-adhesive siloxane layer with an average thickness of 0.4 μm, thereby obtaining the original.

[0291] Using an ArF excimer pulsed laser (wavelength: 193 nm), with a laser irradiation energy density of 150 mJ / cm², 2 Pulse repetition frequency: 10Hz; Laser irradiation atmosphere: Under nitrogen atmosphere conditions, pattern irradiation is performed from the ink-repellent silicone layer side of the obtained original plate. By ablating the entire ink-repellent silicone layer and the upper part of the ink-repellent silicone layer of the laser irradiation area, the original plate is made into a printing plate.

[0292] [Example 15]

[0293] The easy-peel primer layer forming composition-1 is applied to the outer circumferential surface of the aluminum alloy printing plate cylinder sleeve using a cylindrical slot die coater, and heated at 170°C for 10 minutes, thereby setting a continuous easy-peel primer layer with an average thickness of 25 μm.

[0294] Next, the following hydrophilic layer forming composition-1 is applied to the outer peripheral surface of the easily peelable primer layer using a cylindrical slot coater, and heated at 150°C for 5 minutes to form a continuous hydrophilic layer with an average thickness of 3 μm.

[0295] <Composition for Hydrophilic Layer Forming - 1>

[0296] The following components (a-13), (b-13) and (c-13) are added to a container and stirred until homogeneous to obtain composition-1 for forming a hydrophilic layer.

[0297] (a-13) The hydrophilic polymer obtained from the following synthesis example 1: 10 parts by mass

[0298] (b-13)N-hydroxyethylxylbenzenediamine: 1 part by weight

[0299] (c-13) Purified water: 100 parts by weight.

[0300] <Synthesis example 1>

[0301] 0.5 g of benzoyl peroxide was added as a polymerization initiator to 60 g of vinyl acetate and 40 g of methyl acrylate, and dispersed in 300 ml of partially saponified polyvinyl alcohol containing 3 g of partially saponified polyvinyl alcohol as a dispersion stabilizer and 10 g of NaCl:10 g of water. The resulting dispersion was stirred at 65 °C for 6 hours for suspension polymerization. 8.6 g of the resulting copolymer was added to a saponification reaction solution consisting of 200 g of methanol, 10 g of water, and 5 N in 40 ml of NaOH. The mixture was stirred and suspended, and saponification was carried out at 25 °C for 1 hour. The temperature was then increased to 65 °C, and saponification was carried out for another 5 hours. The resulting saponified product was thoroughly washed with methanol and then freeze-dried to obtain a hydrophilic polymer.

[0302] Next, the following ink-adhesive heat-sensitive layer forming composition-1 is applied to the outer peripheral surface of the hydrophilic layer using a cylindrical slot die coater, and heated at 70°C for 5 minutes, thereby setting a continuous ink-adhesive heat-sensitive layer with an average thickness of 3 μm to obtain the original.

[0303] <Composition for Forming Ink-Adhesive Thermal Layers-1>

[0304] The following components are added to a container and stirred until homogeneous to obtain composition-1 for forming an ink-adhesive thermal layer.

[0305] (a-14) "KAYASORB" (registered trademark) IR-820B (infrared absorbing dye, manufactured by Nippon Kayaku Co., Ltd.): 5 parts by weight

[0306] (b-14) Aluminum chelate D (aluminum monoacetylacetone diacetylacetonate aluminum, manufactured by Kawaken Finke Microcarb Co., Ltd.): 20 parts by weight

[0307] (c-14) Epoxy ester 80MFA (Epoxy acrylate, manufactured by Kyoei Chemical Co., Ltd.): 40 parts by weight; (d-14) Polyvinyl alcohol AL-06 (manufactured by Nippon Synthetic Chemical Co., Ltd.): 10 parts by weight.

[0308] (e-14) Polyurethane emulsion "Super Flox" (registered trademark) R-5100 (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.): 40 parts by weight

[0309] (f-14) "Cataloid" (registered trademark) SI-30 (aqueous dispersion of colloidal silica microparticles with an average particle size of 0.01 to 0.014 μm, manufactured by Catalyst Chemical Industry Co., Ltd.): 10 parts by weight

[0310] (g-14) Purified water: 700 parts by weight

[0311] (h-14) Ethylene glycol monoethyl ether: 200 parts by weight.

[0312] Using a semiconductor laser (wavelength: 808nm), with a laser irradiation energy density of 200mJ / cm². 2 Under certain conditions, after exposing the pattern to the ink-repellent thermal layer side of the original plate, the surface is wiped with a cotton ball containing water to remove the unexposed ink-repellent thermal layer, thereby making a printing plate from the original plate to expose the underlying ink-repellent hydrophilic layer.

[0313] [Example 16]

[0314] The easy-peel primer layer forming composition-1 is applied to the outer circumferential surface of the aluminum alloy printing plate cylinder sleeve using a cylindrical slot die coater and heated at 170°C for 10 minutes, thereby setting a continuous easy-peel primer layer with an average thickness of 25 μm.

[0315] Next, the following ink-adhesive heat-sensitive layer forming composition-2 is applied to the outer peripheral surface of the easily peelable primer layer using a cylindrical slot coater, and heated at 150°C for 5 minutes to form a continuous ink-adhesive heat-sensitive layer with an average thickness of 1 μm.

[0316] <Composition for Forming Ink-Adhesive Thermal Layers-2>

[0317] The following components are added to a container and stirred until homogeneous to obtain composition-2 for forming an ink-adhesive thermal layer.

[0318] (a-15) Phenol-formaldehyde varnish resin: "Sumitomo Resin" (registered trademark) PR53195 (manufactured by Sumitomo Baseline Co., Ltd.): 45.0 parts by weight

[0319] (b-15) Polyurethane solution: “Nippon” (registered trademark) 5196 (manufactured by Nippon Polyurethane Co., Ltd., solid content concentration: 30% by weight): 62.5 parts by weight

[0320] (c-15) Infrared absorbing dye: PROJET 825LDI (manufactured by Avecia Co., Ltd.): 12.0 parts by weight; (d-15) Di-n-butoxydi(acetylacetone) titanium solution: "Narsen" (registered trademark) titanium (manufactured by Nippon Chemical Industry Co., Ltd., solid content concentration: 73% by weight): 28.5 parts by weight.

[0321] (e-15) Reaction product of polyoxypropylene diamine / glycidyl methacrylate / 3-epoxypropoxypropyltrimethoxysilane = 1 / 3 / 1 moles (solid content concentration: 50% by weight): 22.5 parts by weight

[0322] (f-15) Tetrahydrofuran: 717.0 parts by weight

[0323] (g-15) Ethanol: 112.5 parts by weight.

[0324] Next, the following ink-repellent silicone layer forming composition-4 is applied to the outer peripheral surface of the ink-repellent heat-sensitive layer using a cylindrical slot die coater, and heated at 150°C for 5 minutes, thereby setting a continuous ink-repellent silicone layer with an average thickness of 3 μm to obtain the original.

[0325] <Composition for Forming Ink-Repellent Organosilicon Layers-4>

[0326] Add components (a-16), (b-16), and (c-16) to a container and stir until homogeneous. Bubble the resulting solution with dry nitrogen for 20 minutes to remove moisture. Add components (d-16), (e-16), and (f-16) to the resulting solution and stir for 10 minutes. Then add component (g-16) and stir for another 10 minutes. Just before coating, add component (h-16) and stir to obtain composition-4 for forming an ink-repellent silicone layer.

[0327] (a-16) "Isoper" (registered trademark) E: 894.05 parts by weight

[0328] (b-16)DMS-V35: 73.68 parts by weight

[0329] (c-16)KF-96-50cs: 2.00 parts by weight

[0330] (d-16) Compounds containing SiH groups (two-terminated trimethylsiloxy-methylhydrosiloxane-dimethylsiloxane copolymer): "HMS"-301 (manufactured by GELEST Inc., weight average molecular weight: 1960, SiH group equivalent: 245, number of SiH groups in the molecule: 8): 2.27 parts by weight

[0331] (e-16) Vinyltris(methylethyl ketone oxime)silane: 1.00 parts by weight

[0332] (f-16) Phenylacetoxysilane: 3.00 parts by weight

[0333] (g-16) Reaction inhibitor: γ-methylpyridine: 1.00 parts by weight

[0334] (h-16)XC94-C4326: 5.00 parts by weight.

[0335] Using a semiconductor laser (wavelength: 808nm), with a laser irradiation energy density of 200mJ / cm².2 Under certain conditions, after exposing the pattern to the ink-repellent silicone layer side of the original plate, the surface is wiped with a cotton ball containing water to remove the ink-repellent silicone layer of the exposed part, thereby making a printing plate from the original plate.

[0336] [Example 17]

[0337] Except that the easy-peel primer layer forming composition-1 is changed to the easy-peel primer layer forming composition-3, the printing plate is obtained by the same method as in Example 16.

[0338] [Example 18]

[0339] Except for changing the average thickness of the easily peelable primer layer from 25 μm to 15 μm, the printing plate was obtained by the same method as in Example 17.

[0340] [Example 19]

[0341] Except for changing the average thickness of the easily peelable primer layer from 25 μm to 12 μm, the printing plate was obtained by the same method as in Example 17.

[0342] [Example 20]

[0343] Except that the easy-peel primer layer forming composition-1 is changed to the easy-peel primer layer forming composition-4, the heating temperature is reduced from 170°C to 80°C, and the average thickness of the easy-peel primer layer is increased from 25 μm to 30 μm, the printing plate is obtained by the same method as in Example 16.

[0344] [Example 21]

[0345] Except for changing the easy-peel primer layer forming composition-1 to the easy-peel primer layer forming composition-5 and changing the heating temperature from 170°C to 80°C, the printing plate was obtained by the same method as in Example 16.

[0346] [Example 22]

[0347] Except for changing the easy-peel primer layer forming composition-1 to the easy-peel primer layer forming composition-6 and changing the heating temperature from 170°C to 120°C, the printing plate was obtained by the same method as in Example 16.

[0348] [Example 23]

[0349] Except for changing the drying conditions of the easily peelable primer layer from heating at 170°C for 10 minutes to heating at 30°C for 3 hours, the printing plate was obtained by the same method as in Example 22.

[0350] [Example 24]

[0351] Except for applying the easily peelable primer layer forming composition-7 to the outer circumferential surface of the aluminum alloy printing plate cylinder sleeve using a cylindrical slot die coater, and curing it by irradiating it with ultraviolet light for 1 minute using an LED linear UV irradiator: UD90, thereby setting a continuous easily peelable primer layer with an average thickness of 25 μm, the printing plate was obtained using the same method as in Example 16.

[0352] [Example 25]

[0353] Except that the easy-peel primer layer forming composition-7 is changed to the easy-peel primer layer forming composition-8, the printing plate is obtained by the same method as in Example 24.

[0354] [Example 26]

[0355] Except for changing the average thickness of the easily peelable primer layer from 25 μm to 50 μm, the printing plate was obtained by the same method as in Example 16.

[0356] [Comparative Example 1]

[0357] Except for the absence of an easily peelable primer layer, the printing plate was obtained using the same method as in Example 1.

[0358] [Comparative Example 2]

[0359] Except that the easy-to-peel primer layer forming composition-1 is changed to the primer layer forming composition-1 described below, the printing plate is obtained by the same method as in Example 1.

[0360] <Composition for Primer Formation-1>

[0361] Add the following components (a-17) and (b-17) to a container and stir until the components are homogeneous to obtain composition 12 for forming a peelable primer layer.

[0362] (a-17) Epoxy resin: "jER" (registered trademark) 828 (bisphenol A type liquid epoxy resin, manufactured by Mitsubishi Kemica Co., Ltd.): 500.0 parts by weight

[0363] (b-17) Polyamine: “GEFAMING” (registered trademark) T-403 (trimethylolpropane poly(oxypropylene)triamine, manufactured by Hantsman Co., Ltd.): 500.0 parts by weight.

[0364] [Comparative Example 3]

[0365] A heat shrink tube (Copalon PTF, material: PET, thickness: 80μm, manufactured by Gunze Polymer Co., Ltd.) is placed on the outer circumference of an aluminum alloy printing cylinder sleeve. The tube is then heated at 120°C for 5 minutes to shrink it, and then fixed to the outer circumference of the printing cylinder sleeve. Next, double-sided adhesive tape 777 (manufactured by Teraoka Corporation) is applied to the outer circumference of the shrunken heat shrink tube, and then a single-page horizontal platen master plate (TAC-VT4, manufactured by Toray Industries, Inc.) is wound around and fixed. The gap (approximately 0.5mm) between the beginning and end of the wound single-page horizontal platen is filled with the ink-repellent silicone layer forming composition-1, and then heated at 150°C for 5 minutes to cure it, thereby obtaining the master plate.

[0366] [Example 27]

[0367] The average thickness of the easy-peel primer layer was changed from 25 μm to 15 μm, and the heating time of the easy-peel primer layer was changed from 10 minutes to 20 minutes. Otherwise, the printing plate was obtained using the same method as in Example 1.

[0368] [Example 28]

[0369] The average thickness of the easy-peel primer layer was changed from 25 μm to 15 μm, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 1.

[0370] [Example 29]

[0371] The average thickness of the easy-peel primer layer was changed from 25 μm to 20 μm, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 1.

[0372] [Example 30]

[0373] The average thickness of the easy-peel primer layer was changed from 25 μm to 20 μm, the heating temperature of the easy-peel primer layer was changed from 170°C to 185°C, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 1.

[0374] [Example 31]

[0375] The average thickness of the easy-peel primer layer was changed from 25 μm to 30 μm, the heating temperature of the easy-peel primer layer was changed from 170°C to 185°C, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 1.

[0376] [Example 32]

[0377] The average thickness of the easy-peel primer layer was changed from 25 μm to 30 μm, the heating temperature of the easy-peel primer layer was changed from 170°C to 200°C, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 1.

[0378] [Example 33]

[0379] The average thickness of the easy-peel primer layer was changed from 25 μm to 15 μm, and the heating time of the easy-peel primer layer was changed from 10 minutes to 20 minutes. Otherwise, the printing plate was obtained using the same method as in Example 16.

[0380] [Example 34]

[0381] The average thickness of the easy-peel primer layer was changed from 25 μm to 15 μm, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 16.

[0382] [Example 35]

[0383] The average thickness of the easy-peel primer layer was changed from 25 μm to 20 μm, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 16.

[0384] [Example 36]

[0385] The average thickness of the easy-peel primer layer was changed from 25 μm to 20 μm, the heating temperature of the easy-peel primer layer was changed from 170°C to 185°C, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 16.

[0386] [Example 37]

[0387] The average thickness of the easy-peel primer layer was changed from 25 μm to 30 μm, the heating temperature of the easy-peel primer layer was changed from 170°C to 185°C, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 16.

[0388] [Example 38]

[0389] The average thickness of the easy-peel primer layer was changed from 25 μm to 30 μm, the heating temperature of the easy-peel primer layer was changed from 170°C to 200°C, and the heating time of the easy-peel primer layer was changed from 10 minutes to 30 minutes. Otherwise, the printing plate was obtained using the same method as in Example 16.

[0390] The evaluation results for Examples 1-26 and Comparative Examples 1-3 are shown in Table 1. The evaluation results for Examples 27-38 are shown in Table 2. Furthermore, since no primer layer was provided in Comparative Examples 1 and 3, the column “(1) Evaluation of Primer Layer” in Table 1 is empty. Also, in Comparative Example 2, since the primer layer could not be peeled off from the printing cylinder sleeve using a dry process, the columns for adhesion, film strength, and elongation at break in the “(1) Evaluation of Peelable Primer Layer” section of Table 1 are empty.

[0391] Table 1

[0392]

[0393] Table 2

[0394]

[0395] Explanation of symbols in attached drawings

[0396] A discontinuous pattern

[0397] B Continuous Pattern

[0398] D Printing Direction

[0399] E Seamless Lithographic Printing Plate F Seamless Printing

[0400] P Printing

[0401] R1 Print Edition, Week 1

[0402] R2 Print Edition, Week 2

[0403] 1. Line drawing section

[0404] 2 Non-lined parts

[0405] 3 Printing media

[0406] 4 Transfer Patterns

[0407] 5 ink rollers

[0408] 6 Wetting rollers

[0409] 7 Seamless lithographic printing plates

[0410] 8 rubber blanket rollers

[0411] 9 Printed media

[0412] 10 Impression Rollers

Claims

1. A seamless offset printing plate master, comprising sequentially having a peelable primer layer and an ink-repellent layer on the outer peripheral surface of a cylindrical support, wherein the peelable primer layer contains a compound having a functional group with a cohesion energy of 20–60 kJ / mol, and the compound having the functional group with a cohesion energy of 20–60 kJ / mol contains polyurethane. The adhesion force between the cylindrical support and the easily peelable primer layer is less than the film strength of the easily peelable primer layer.

2. The seamless offset printing plate original as described in claim 1, wherein the adhesion force between the cylindrical support and the easily peelable primer layer is 10-2000 N / m.

3. The seamless offset printing plate original as described in claim 1, wherein the elongation at break of the easily peelable primer layer is 10 to 1000%.

4. The seamless offset printing plate original as described in claim 1, wherein the average thickness of the easily peelable primer layer is 15–500 μm.

5. The seamless lithographic printing plate original as described in claim 1, wherein there is no covalent bond between the easily peelable primer layer and the outer peripheral surface of the cylindrical support.

6. The seamless offset printing plate original as described in claim 1, wherein the ink-repellent layer is an organosilicon layer.

7. The seamless offset printing plate as claimed in claim 1, wherein an ink layer is continuously provided between the peelable primer layer and the ink-repellent layer, or further outside the ink-repellent layer.

8. The seamless offset printing plate original as described in claim 7, wherein the ink layer is a photosensitive layer or a thermally sensitive layer.

9. A seamless lithographic printing plate, which is obtained by making a plate from the seamless lithographic printing plate original according to any one of claims 1 to 8.

10. A method for regenerating a cylindrical support, wherein the easily peelable primer layer is peeled into a film from the outer peripheral surface of the cylindrical support of the seamless lithographic printing plate original or the seamless lithographic printing plate of claim 9 by a dry process.

11. A method for manufacturing a seamless lithographic printing plate original, wherein an easily peelable primer layer and an ink-repellent layer are sequentially and continuously formed on the outer peripheral surface of a cylindrical support regenerated by the method of claim 10.

12. A method for manufacturing a seamless lithographic printing plate original, comprising the method of manufacturing a seamless lithographic printing plate original according to any one of claims 1 to 8, wherein a composition for forming an easily peelable primer layer is coated on the outer peripheral surface of a cylindrical support, and dried under heating or without heating, thereby forming the easily peelable primer layer.

13. A method for manufacturing a seamless lithographic printing plate original, comprising the method of manufacturing a seamless lithographic printing plate original according to any one of claims 1 to 8, wherein an easy-to-peel primer layer forming composition is coated on the outer peripheral surface of a cylindrical support, and the easy-to-peel primer layer forming composition is cured by irradiation with active energy rays, thereby forming the easy-to-peel primer layer.

14. The method for manufacturing a seamless lithographic printing plate original as described in claim 13, wherein the composition for forming an easily peelable primer layer contains a compound having a urethane bond as a functional group with a cohesion energy of 20 to 60 kJ / mol, and the compound having a urethane bond also has an olefinic unsaturated double bond in its molecule.

15. The method for manufacturing a seamless lithographic printing plate original as described in any one of claims 12 to 14, wherein the cylindrical support body is a cylindrical support body regenerated by the method described in claim 10.

Images