WO2023032775A1 - Seamless lithographic printing plate precursor, seamless lithographic printing plate, recycling method for cylindrical support body, seamless lithographic printing plate precursor production method, and composition for forming easily releasable primer layer - Google Patents

Abstract

The purpose of the present invention is to obtain a seamless lithographic printing plate precursor and a seamless lithographic printing plate excelling in image reproducibility, which are necessary for obtaining high-definition seamless printed matter. Moreover, another purpose is to obtain a seamless lithographic printing plate precursor and a seamless lithographic printing plate wherein recycling of a cylindrical support body is easy. The present invention provides a seamless lithographic printing plate precursor having an easily releasable primer layer and an ink-repellent layer, in that order, both continuously, on the outer circumferential surface of the cylindrical support body.

Description

Seamless lithographic printing plate precursor, seamless lithographic printing plate, method for recycling cylindrical support, method for producing seamless lithographic printing plate precursor, and composition for forming easily peelable primer layer

The present invention relates to a seamless lithographic printing plate precursor, a seamless lithographic printing plate, a method for recycling a cylindrical support, a method for producing a seamless lithographic printing plate precursor, and a composition for forming an easily peelable primer layer.

There are various printing methods such as letterpress printing, intaglio printing, stencil (screen) printing, and lithographic printing, and the characteristics of each method are used for printing. Among these, lithographic printing is more advantageous than other printing methods in that printed matter with high definition can be obtained.

In the field of flexible packaging printing, etc., seamless printing is performed in which intermittent patterns and continuous patterns are repeatedly formed on a long medium to be printed. A method of making a lithographic printing member (see, e.g., US Pat. No. 6,300,001) covering a first polymeric layer of and a silicon layer, and applying a coating to the cylindrical surface to alter its affinity for oil and water by a conversion treatment. A method of hardening by pressing (see, for example, Patent Document 2) has been proposed. In addition, as a method for attaching the printing plate to the sleeve so that the printing plate can be easily removed, a protective layer forming step of forming a protective layer protecting the outer peripheral surface of the sleeve on the outer peripheral surface of the sleeve; A method comprising an adhesive layer forming step of forming an adhesive layer for adhering a plate and a printing plate adhering step of adhering a printing plate to the surface of the adhesive layer has been proposed, and a heat-shrinkable film is described as a protective layer. (See Patent Document 3, for example).

JP-A-7-309001 JP-A-9-99535 Japanese Patent Application Laid-Open No. 2006-231758

Cylindrical supports such as plate cylinders and plate cylinder sleeves are useful as supports for seamless lithographic printing plates. In addition to being expensive, from the viewpoint of environmental impact, it is desirable to recycle a cylindrical support from a seamless lithographic printing plate after printing and repeatedly manufacture a seamless lithographic printing plate using the regenerated cylindrical support. is desired.

With the seamless lithographic printing plates described in Patent Documents 1 and 2, high-definition seamless prints can be obtained. In order to regenerate , wet processes such as washing with a solvent and complicated operations such as polishing of the outer peripheral surface of the support were required.

The seamless lithographic printing plate described in Patent Document 3 has the advantage that a high-definition seamless printed matter can be obtained, and the sleeve can be recycled simply by peeling off the heated heat-shrinkable film by a dry process. However, since the sheet-fed lithographic printing plate is wrapped around the sleeve and there is a seam between the plate head and the plate bottom, it has been impossible to obtain a seamless printed material with a continuous pattern.

Therefore, the problem to be solved by the present invention is to provide a seamless lithographic printing plate precursor whose cylindrical support is easy to recycle and from which high-definition continuous patterns can be obtained.

In order to solve the above problems, the present invention is as follows.
(1) A seamless lithographic printing plate precursor having an easy-peelable primer layer and an ink-repellent layer in this order on the outer peripheral surface of a cylindrical support.
(2) The seamless lithographic printing plate precursor as described in (1), wherein the adhesive strength between the cylindrical support and the easily peelable primer layer is less than the film strength of the easily peelable primer layer.
(3) The seamless lithographic printing plate precursor as described in (1) or (2), wherein the adhesive strength between the cylindrical support and the easily peelable primer layer is 10 to 2,000 N/m.
(4) The seamless lithographic printing plate precursor as described in any one of (1) to (3), wherein the easily peelable primer layer has an elongation at break of 10 to 1,000%.
(5) The seamless lithographic printing plate precursor as described in any one of (1) to (4), wherein the easily peelable primer layer has an average thickness of 15 to 500 μm.
(6) The seamless lithographic printing plate precursor as described in any one of (1) to (5), wherein the easily peelable primer layer contains a compound having a functional group with a cohesive energy of 20 to 60 kJ/mol.
(7) The seamless lithographic printing plate precursor according to any one of (1) to (6), wherein no covalent bond is formed between the easily peelable primer layer and the outer peripheral surface of the cylindrical support.
(8) The seamless lithographic printing plate precursor as described in (6), which contains polyurethane as the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol.
(9) The seamless lithographic printing plate precursor as described in any one of (1) to (8), wherein the ink repellent layer is a silicone layer.
(10) According to any one of (1) to (9), having an ink receptive layer continuously between the easily peelable primer layer and the ink repellent layer or further outside the ink repellent layer. seamless lithographic printing plate precursor.
(11) The seamless lithographic printing plate precursor as described in (10), wherein the ink receiving layer is a photosensitive layer or a heat-sensitive layer.
(12) A seamless lithographic printing plate obtained by making the seamless lithographic printing plate precursor according to any one of (1) to (11).
(13) The easily peelable primer layer is removed from the outer peripheral surface of the cylindrical support of the seamless lithographic printing plate precursor according to any one of (1) to (11) or the seamless lithographic printing plate according to (12). A method for regenerating a cylindrical support, which is peeled into a film by a dry process.
(14) A seamless lithographic printing plate precursor in which an easily peelable primer layer and an ink repellent layer are both continuously formed in this order on the outer peripheral surface of the cylindrical support regenerated by the method described in (13). Production method.
(15) A method for producing a seamless lithographic printing plate precursor according to any one of (1) to (11), wherein the composition for forming an easily peelable primer layer is applied to the outer peripheral surface of the cylindrical support. A method for producing a seamless lithographic printing plate precursor, wherein the easily peelable primer layer is formed by drying with or without heating.
(16) A method for producing a seamless lithographic printing plate precursor according to any one of (1) to (11), wherein the composition for forming an easily peelable primer layer is applied to the outer peripheral surface of the cylindrical support. A method for producing a seamless lithographic printing plate precursor, wherein the easily peelable primer layer is formed by irradiating an active energy ray to cure the composition for forming an easily peelable primer layer.
(17) The method for producing a seamless lithographic printing plate precursor as described in (15) or (16), wherein a cylindrical support regenerated by the method as described in (13) is used as the cylindrical support.
(18) A composition for forming an easily peelable primer layer, containing a compound having a functional group with a cohesive energy of 20 to 60 kJ/mol.
(19) The composition for forming an easily peelable primer layer according to (18), wherein the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol includes a compound having a urethane bond and/or a hydroxyl group.
(20) For forming an easily peelable primer layer according to (18) or (19), wherein the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol further has an ethylenically unsaturated double bond in the molecule. Composition.
(21) The composition for forming an easily peelable primer layer according to (19), which contains polyurethane as the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol.
(22) The composition for forming an easily peelable primer layer according to any one of (18) to (21), which further contains inorganic particles.

According to the present invention, it is possible to obtain a seamless lithographic printing plate precursor from which a cylindrical support can be easily recycled and a high-definition continuous pattern can be obtained.

FIG. 4 is a schematic diagram showing the difference between intermittent patterns and continuous patterns in seamless printing. It is a schematic sectional drawing which shows an example of the manufacturing method of a seamless printed matter.

The seamless lithographic printing plate precursor of the present invention refers to a printing plate precursor used for seamless printing, and has an easily peelable primer layer and an ink repellent layer, both in this order, continuously on the outer peripheral surface of a cylindrical support. . Hereinafter, the seamless lithographic printing plate precursor may be referred to as "original plate".

Seamless printing in the present invention refers to a method of repeatedly printing the same pattern or pattern on a long print medium, and by such a printing method, an intermittent pattern or a continuous pattern is printed on the print medium. A seamless print is obtained which is formed repeatedly. A lithographic printing plate used for seamless printing is called a seamless lithographic printing plate, and a seamless lithographic printing plate can be obtained from a seamless lithographic printing plate precursor by, for example, a method described later. Hereinafter, the seamless lithographic printing plate may be referred to as "printing plate".

Here, the difference between intermittent patterns and continuous patterns in seamless printing according to the present invention will be explained using FIG. FIG. 1 is a schematic diagram showing the difference between an intermittent pattern A and a continuous pattern B in seamless printing. On the left and right sides of FIG. 1, a seamless lithographic printing plate E used for seamless printing of an intermittent pattern and a continuous pattern, respectively, and a seamless printed matter F obtained by performing seamless printing using the seamless lithographic printing plate E are shown. showing. The seamless lithographic printing plate E has an image area 1 to which ink adheres and a non-image area 2 to which ink does not adhere. In this case, the image line portion 1 (picture) is arranged continuously in the printing direction D. In seamless printing, the ink adhering to the image area 1 is transferred onto the print medium 3 directly or through a blanket to form a transfer pattern 4 .

The printing plate described in Japanese Patent Laid-Open No. 2006-231758 exemplified as Patent Document 3 of the prior art and the printing plate described in Comparative Example 3 described later are obtained by winding a sheet-shaped lithographic printing plate around the outer peripheral surface of a cylindrical support. The gap between the head and bottom of the print is filled with the composition for forming an ink repellent layer and cured to form an ink repellent portion (non-printing portion). For this reason, by arranging the pattern so that the ink repelling part (non-printing part) in the gap between the head and the bottom of the block is aligned with the part where the pattern is interrupted in the intermittent pattern, it is impossible to obtain a seamless printed matter of the intermittent pattern. can. However, it is not possible to form an image line portion in the ink repulsive portion between the head and the bottom of the plate, and therefore it is not possible to obtain a seamless printed matter with a continuous pattern in which there is no discontinuity in the pattern.

In the original plate of the present invention, an easily peelable primer layer, an ink repellent layer, and other functional layers are continuously provided without gaps in the circumferential direction and axial direction of the original plate. Therefore, it is possible to produce a printing plate having a continuous image portion without gaps in the circumferential direction, and to obtain a seamless printed material with a continuous pattern without any discontinuous portions in the pattern. Here, "continuously" refers to a state in which each functional layer is provided without gaps in the circumferential direction or the axial direction in the master.

For example, when the easily peelable primer layer has ink receptivity, or when it has an ink receptive layer continuously between the easily peelable primer layer and the ink repellent layer or further outside the ink repellent layer. , a continuous image can be formed on the printing plate. Further, by modifying the ink repellent layer to have ink receptivity by pattern irradiation of active energy rays, etc., or by discharging and curing the ink receptive part forming composition in a pattern on the ink repellent layer, A continuous image can be formed on the printing plate.

First, the original plate according to the present invention will be explained.

The original plate according to the present invention has an easily peelable primer layer and an ink repellent layer in this order on the outer peripheral surface of a cylindrical support, both continuously. Here, "continuously" refers to a state in which both the easily peelable primer layer and the ink repellent layer are provided in the circumferential direction and the axial direction without gaps in the master. As mentioned above, the easily peelable primer layer, ink repellent layer, and other functional layers exist continuously in the circumferential and axial directions of the original plate, so that intermittent or continuous patterns can be formed on the printing plate. Since it can be formed, it is possible to perform seamless printing in which a pattern of intermittent patterns or continuous patterns is repeatedly formed on a long medium to be printed.

As the material constituting the cylindrical support, dimensionally stable metals and plastics are preferable. For example, metals such as aluminum, iron, zinc, and copper, alloys containing these metals as main components, epoxy resins, and phenolic resins. , ester resins, vinyl ester resins, amide resins and imide resins, and fiber-reinforced plastics containing these plastics and fibers such as glass fibers, carbon fibers, aramid fibers, polyethylene fibers, Zylon fibers and boron fibers. Aluminum alloys and fiber-reinforced plastics are preferable because they are lightweight and easy to handle.

The cylindrical support is preferably the plate cylinder of the printing press, since printing can be performed immediately after the printing plate is produced from the original plate. Above all, the cylindrical support is a plate cylinder sleeve that can be detached from the plate cylinder shaft, so that the series of steps up to the production of the printing plate and the operation of regenerating the cylindrical support after printing can be performed outside the printing machine. , more preferred.

As for the dimensions of the cylindrical support, the appropriate diameter and width should be selected for the plate cylinder of the printing machine used.

The easily peelable primer layer in the present invention refers to a layer laminated directly, i.e., adjacently, on the outer peripheral surface of a cylindrical support, which can be peeled from the outer peripheral surface of the cylindrical support into a film by a dry process. . Since the easily peelable primer layer and the functional layers provided on the outer peripheral surface can be peeled off in a film form from the outer peripheral surface of the cylindrical support by a dry process, wet processes such as cleaning using chemicals can be used. Also, the cylindrical support can be easily regenerated without requiring complicated operations such as polishing the outer peripheral surface of the support.

The adhesive force between the cylindrical support of the original plate of the invention and the easily peelable primer layer is preferably 10 to 2,000 N/m. By setting the adhesion force to 10 N/m or more, the printing plate can be stably held during printing, and printing durability can be improved. The adhesion force is more preferably 30 N/m or more. On the other hand, by setting the adhesive strength to 2,000 N/m or less, the easily peelable primer layer can be more easily peeled off, and the cylindrical support can be more easily recycled. The adhesive strength is preferably 1,000 N/m or less, more preferably 800 N/m or less.

Examples of means for adjusting the adhesive strength to the above range include a method of forming an easily peelable primer layer using an easily peelable primer layer forming composition described later.

The adhesion between the cylindrical support and the easily peelable primer layer is measured by measuring the force required to peel off the easily peelable primer layer of a specified width from the outer peripheral surface of the cylindrical support with a force gauge. can be obtained by Specifically, a 0.1 m wide, 0.1 m long strip-shaped primer was applied with a razor to a position randomly selected from the easily peelable primer layer provided on the outer peripheral surface of the cylindrical support. is cut, and the force [N/0.1 m] when peeling off the easily peelable primer layer from the cylindrical support by 0.05 m in the length direction is measured using a force gauge. By multiplying the obtained peel force [N/0.1 m] by 10, the adhesion force [N/m] between the cylindrical support and the easily peelable primer layer can be obtained.

The adhesive strength between the cylindrical support of the original plate of the invention and the easily peelable primer layer is preferably less than the film strength of the easily peelable primer layer. By setting the adhesive strength between the cylindrical support and the easily peelable primer layer to be less than the film strength of the easily peelable primer layer, the easily peelable primer layer can be easily peeled off, and the cylindrical support can be more easily recycled. can do. More preferably, the film strength of the easily peelable primer layer is at least 1.5 times the adhesion between the cylindrical support and the easily peelable primer layer.

As means for adjusting the relationship between the film strength of the easily peelable primer layer and the adhesion force between the cylindrical support and the easily peelable primer layer within the above range, for example, the average thickness of the easily peelable primer layer is preferably set as described below. Examples include a method of setting the range, a method of forming an easily peelable primer layer using an easily peelable primer layer forming composition described below, and the like.

The film strength of the easily peelable primer layer can be obtained by measuring the tensile strength of the easily peelable primer layer and the average thickness of the easily peelable primer layer. Specifically, the product of the tensile strength [N/mm ² ] of the easily peelable primer layer and the average thickness [mm] of the easily peelable primer layer is the film strength of the easily peelable primer layer [N/mm]. is. The film strength [N/mm] of the obtained easily peelable primer layer is multiplied by 1,000 to obtain the unit [N/m], and the adhesive strength [N /m], it becomes easier to understand the relationship between the two.

The tensile strength of the easily peelable primer layer can be measured by the method specified in JIS K 6251:2017.

In addition, the average thickness of the easily peelable primer layer can be obtained by cross-sectional SEM observation or cross-sectional TEM observation. More specifically, after embedding a film obtained by peeling the easily peelable primer layer from the original plate, the cross section of the sample prepared by the ultra-thin section method is magnified and observed using SEM or TEM. The average thickness can be determined by measuring the thickness of 10 randomly selected spots on the easily peelable primer layer in the vertical cross-sectional image and calculating the number average value. Since the thickness of the easily peelable primer layer does not change even in the process of manufacturing the printing plate from the original plate, the average thickness of the easily peelable primer layer may be similarly obtained from the printing plate instead of the original plate. .

The elongation at break of the easily peelable primer layer of the original plate of the present invention is preferably 10 to 1,000%. By setting the elongation at break to 10% or more, the easily peelable primer layer can be peeled off more easily, and the cylindrical support can be more easily recycled. The elongation at break is more preferably 20% or more. On the other hand, by setting the elongation at break to 1,000% or less, the deformation of the peeling film is suppressed, the peeling of the easily peelable primer layer becomes easier, and the cylindrical support can be more easily recycled. The elongation at break is more preferably 800% or less.

Means for adjusting the elongation at break of the easily peelable primer layer to the above range include, for example, a method of forming an easily peelable primer layer using the easily peelable primer layer-forming composition described later.

The elongation at break of the easily peelable primer layer can be measured by the method specified in JIS K 6251:2017.

The average thickness of the easily peelable primer layer of the original plate of the present invention is preferably 15 to 500 μm. By setting the average thickness to 15 μm or more, the easily peelable primer layer can be more easily peeled off, and the cylindrical support can be more easily recycled. In addition, the film strength of the easily peelable primer layer can be appropriately increased. As for average thickness, 20 micrometers or more are more preferable. On the other hand, by setting the average thickness to 500 μm or less, the drying efficiency of the easily peelable primer layer can be improved, and the residual stress and residual strain of the easily peelable primer layer after drying and after curing can be reduced. As for average thickness, 300 micrometers or less are more preferable. The average thickness of the easily peelable primer layer can be determined by the method described above.

The original plate of the present invention preferably contains a compound having a functional group with a cohesive energy of 20 to 60 kJ/mol in the easily peelable primer layer. By containing such a compound, the adhesion to the cylindrical support and the film strength can be improved, and the preferred ranges described above can be easily adjusted. Furthermore, it is preferable that there is no covalent bond between the easily peelable primer layer and the outer peripheral surface of the cylindrical support. By not having a covalent bond, the adhesion to the cylindrical support is moderately suppressed, and the easily peelable primer layer can be easily peeled off from the outer peripheral surface of the cylindrical support in a film form by a dry process. . That is, the adhesion force to the cylindrical support can be easily adjusted within the preferred range described above.

Functional groups with a cohesive energy of 20 to 60 kJ/mol include, for example, a carboxyl group (23.4 kJ/mol), a hydroxyl group (24.3 kJ/mol), an isourea bond (27.7 kJ/mol), a urethane bond (36 .8 kJ/mol), allophanate bond (38.9 kJ/mol), urea bond (41.8 kJ/mol), biuret bond (58.5 kJ/mol), and the like. Two or more of these may be included. Incidentally, each of the above cohesive energies is derived from the numerical value used in the method of estimating the solubility parameter based on the molecular structure proposed by Fedors (RF Fedors, Polym. Eng. Sci., 14, 147 (1974)). calculated value.

Polyurethane is preferred as the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol. That is, the original plate of the present invention preferably contains polyurethane as the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol. Since polyurethane has urethane bonds with high cohesive energy in its molecule, it can improve adhesion to a cylindrical support and film strength, and can be easily adjusted to the preferred ranges described above. Moreover, since it has a flexible segment such as polyether or polyester in the molecule, the elongation at break of the easily peelable primer layer can be improved, and it can be easily adjusted to the preferred range described above. Among them, those having high tensile strength after drying are preferable, and examples thereof include "Crisbon" (registered trademark) 8966 and 9004 (both manufactured by DIC Corporation). Polyurethane emulsions in which polyurethane particles having a high tensile strength after drying are dispersed in a dispersion medium such as water may also be used. ), and more specifically, "Super Flex" (registered trademark) 150 (tensile strength: 45 N/mm ² , manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Polyurethane preferably has a carboxyl group or a hydroxyl group, improves adhesion to a cylindrical support and film strength, and can be easily adjusted to the preferred ranges described above. In addition, the adhesion to the layer on the easily peelable primer layer can be improved. Polyurethanes having hydroxyl groups include, for example, "SAMPLEN" (registered trademark) IB series (manufactured by Sanyo Chemical Industries, Ltd.).

The easily peelable primer layer may contain inorganic particles. Since a tougher film can be obtained due to the filler effect of the inorganic particles, it is possible to make the easily peelable primer layer thinner.

Carbon black and silica particles are preferable as inorganic particles, and silica particles are more preferable in terms of plate inspection. Examples of silica particles include "AEROSIL" (registered trademark) series (manufactured by Nippon Aerosil Co., Ltd.).

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

The ink repellent layer of the original plate of the present invention includes addition reaction type, condensation reaction type, and addition reaction-condensation reaction type silicone layers and fluororesin layers that have been disclosed as ink repellent layers for waterless lithographic printing plates. , a hydrophilic layer disclosed as an ink-repellent layer for wet lithographic printing plates, and the like. In the original plate of the present invention, the ink repellent layer is preferably a silicone layer.

Addition reaction type, condensation reaction type, and addition reaction-condensation reaction combined type ink repellent silicone layer includes, for example, a layer exemplified as a diorganosiloxane unit-containing layer in JP-A-2021-66175, International Publication No. 2019. /203261 as a silicone rubber layer, and a layer exemplified as a first silicone layer in International Publication No. 2019/203263.

For the purpose of improving the adhesive strength between the easily peelable primer layer/ink repellent layer and between the easily peelable primer layer/ink receptive layer to be described later, the easily peelable primer layer/ink repellent layer and the easily peelable primer layer/ink An adhesive layer may be continuously provided between the inked layers. Here, "continuously" refers to a state in which the adhesive layer is provided without gaps in the circumferential direction or the axial direction in the master.

Examples of the adhesive layer include layers described as heat insulating layers in JP-A-2004-199016, JP-A-2004-334025, and JP-A-2006-276385.

The average thickness of the adhesive layer is preferably 0.1 μm or more from the viewpoint of improving the scratch resistance and printing durability of the printing plate, and is preferably 30 μm or less from the viewpoint that the diluent solvent easily evaporates and the productivity is excellent. 0.2 to 20 μm is more preferable.

As described above, the original plate according to the present invention can form a continuous image area on the printing plate. , it is preferable to have an ink-receiving layer continuously. Here, "continuously" refers to a state in which the ink-receiving layer is provided in the circumferential direction and the axial direction without gaps in the master.

As an aspect of the original plate according to the present invention,
(1) A mode in which both the easily peelable primer layer and the ink repellent layer are continuously provided in this order on the outer peripheral surface of the cylindrical support,
(2) An embodiment in which an easily peelable primer layer, an ink repellent layer, and an ink receiving layer are continuously provided in this order on the outer peripheral surface of the cylindrical support,
(3) A mode in which an easily peelable primer layer, an ink receptive layer, and an ink repellent layer are all continuously provided in this order on the outer peripheral surface of the cylindrical support,
etc.

In the aspect (2), as the ink receiving layer, for example, the ink receiving silicone layer exemplified as the second silicone layer in International Publication No. 2019/203263 can be used. In another aspect of (2), as the ink repellent layer, a hydrophilic layer that has been disclosed as an ink repellent layer for a wet lithographic printing plate can be used, and as the ink receptive layer, a Ink-receiving layers disclosed as photosensitive layers and heat-sensitive layers for wet lithographic printing plates can be used.

In the aspect (3), as the ink-receiving layer, an ink-receiving layer disclosed as a photosensitive layer or a heat-sensitive layer for a waterless lithographic printing plate can be used.

Next, I will explain the method of manufacturing the master plate. The original plate according to the present invention is obtained by providing an easily peelable primer layer and an ink repellent layer in this order on the outer peripheral surface of a cylindrical support without gaps in both the circumferential direction and the axial direction. As the cylindrical support, it is preferable to use one that has been regenerated by the method for regenerating a cylindrical support of the present invention, which will be described later. That is, in one aspect of the method for producing a master plate of the present invention, an easily peelable primer layer and an ink repellent layer are formed in this order on the outer peripheral surface of a cylindrical support that has been regenerated by the method for regenerating a cylindrical support of the present invention. Both are formed continuously.

As a method for forming an easily peelable primer layer, for example, a method of continuously applying a composition for forming an easily peelable primer layer, which will be described later, onto the outer peripheral surface of a cylindrical support, and drying the composition with or without heating. is mentioned. For the purpose of promoting drying, it is preferable to heat at a temperature of 50 to 180° C. for 30 seconds to 10 minutes using a known hot air drying device or infrared drying device. That is, one aspect of the method for producing the original plate of the present invention is a method for producing the original plate of the present invention, wherein the composition for forming an easily peelable primer layer is applied to the outer peripheral surface of a cylindrical support, and heated. Alternatively, the easily peelable primer layer is formed by drying without heating. As the cylindrical support, it is preferable to use one that has been regenerated by the method for regenerating a cylindrical support of the present invention, which will be described later. As another method for forming an easily peelable primer layer, for example, the composition for forming an easily peelable primer layer, which will be described later, is continuously applied to the outer peripheral surface of a cylindrical support and irradiated with an active energy ray. and curing the easily peelable primer layer-forming composition. That is, one aspect of the method for producing an original plate of the present invention is a method for producing an original plate of the present invention, wherein the composition for forming an easily peelable primer layer is applied to the outer peripheral surface of a cylindrical support, and activated energy is applied. The easily peelable primer layer is formed by curing the easily peelable primer layer-forming composition by irradiating rays. As the cylindrical support, it is preferable to use one that has been regenerated by the method for regenerating a cylindrical support of the present invention, which will be described later. Active energy rays include, for example, visible rays, ultraviolet rays (UV), electron beams (EB), X-rays, and particle beams. Ultraviolet rays are preferred from the viewpoint of ease of handling of the radiation source, and active energy rays are preferred. As the irradiation device, an ultraviolet irradiation device such as a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, and an LED-UV is preferably used.

As a method for forming the ink repellent layer, for example, a method of continuously applying an ink repellent layer forming composition described later on the outer peripheral surface of the easily peelable primer layer, and drying/curing the composition with or without heating, or the like. mentioned. For the purpose of accelerating drying and curing, it is preferable to heat at a temperature of 50 to 180° C. for 30 seconds to 10 minutes.

As another method of continuously providing both the easily peelable primer layer and the ink repellent layer in this order on the outer peripheral surface of the cylindrical support, for example, an easily peelable primer layer, which will be described later, is applied to the outer peripheral surface of the cylindrical support. After continuously applying the composition for forming a primer layer and then continuously applying the composition for forming an ink repellent layer, which will be described later, on the outer peripheral surface thereof, <1> an active energy ray is applied from the side of the composition for forming an ink repellent layer. to cure the composition for forming an easily peelable primer layer, and then drying/curing the composition for forming an ink repellent layer with or without heating; <2> with or without heating; A method of drying/curing the composition for forming the ink repellent layer and then irradiating the composition for forming the easily peelable primer layer with an active energy ray from the ink repellent layer side to cure the composition. A method of simultaneously performing irradiation with an energy beam to cure the easily peelable primer layer-forming composition and drying/curing of the ink repellent layer-forming composition with or without heating. method. In each of the methods <1> to <3>, it is preferable to heat at a temperature of 50 to 180° C. for 30 seconds to 10 minutes for the purpose of promoting drying and curing of the composition for forming an ink repellent layer after coating.

Examples of methods for applying the easily peelable primer layer-forming composition and the ink repellent layer-forming composition include a dipping method, a spraying method, and a cylindrical slit die coating method.

If necessary, when the adhesive layer and the ink receiving layer are formed continuously, the coating method includes, for example, the dipping method, the spraying method, and the cylindrical slit die coating method. For the purpose of promoting drying, it is preferable to heat at a temperature of 50 to 180° C. for 30 seconds to 10 minutes using a known hot air drying device or infrared drying device.

Next, the composition for forming an easily peelable primer layer and the composition for forming an ink repellent layer that are preferably used in the above aspect (1) will be described. The composition for forming an easily peelable primer layer in the present invention represents a composition used for forming an easily peelable primer layer. Represents the composition used to form the layer.

The easily peelable primer layer-forming composition preferably contains a compound having a functional group with a cohesive energy of 20 to 60 kJ/mol. Functional groups with a cohesive energy of 20 to 60 kJ/mol include the aforementioned carboxyl group, hydroxyl group, isourea bond, urethane bond, allophanate bond, urea bond and biuret bond.

Embodiments of the composition for forming an easily peelable primer layer include (a) a composition for forming an easily peelable primer layer containing a high tensile strength polymer having a tensile strength of 25 N/mm ² or more and a solvent, and (b) A composition for forming an easily peelable primer layer containing a low tensile strength polymer having a tensile strength of less than 25 N/mm ² , inorganic particles and a solvent, (c) a composition for forming a photocurable easily peelable primer layer, etc. mentioned.

As the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol in the aspect (a) above, polyurethane is preferable, and examples of polyurethane having high tensile strength in the explanation of the easily peelable primer layer can be mentioned. be done.

Polyurethane is also preferable as the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol in the aspect (b) above. The tensile strength of the membrane after drying does not necessarily have to be high. In addition, the polyurethane preferably has a carboxyl group or a hydroxyl group, which improves the adhesion to the cylindrical support and the film strength, and can be easily adjusted to the preferred ranges described above. In addition, the adhesion to the layer on the easily peelable primer layer can be improved. Examples of the hydroxyl-containing polyurethane include those exemplified as the hydroxyl-containing polyurethane in the description of the easily peelable primer layer.

Carbon black and silica particles are preferable as the inorganic particles, and silica particles are more preferable in terms of plate inspection properties. Examples of silica particles include those exemplified as silica particles in the description of the easily peelable primer layer.

In the above aspect (a) or (b), the solvent is preferably one capable of dissolving polyurethane, such as N,N-dimethylformamide, N,N-dimethylacetamide, cyclohexanone, cyclopentanone, γ-butyrolactone, Tetrahydrofuran, 2-butanone, ethyl acetate, 2-propanol, toluene and the like. Two or more of these may be included. The boiling point of the solvent at 1 atm is preferably 50° C. or higher, more preferably 70° C. or higher, from the viewpoint of leveling of the coating liquid. On the other hand, the boiling point of the solvent at 1 atm is preferably 160° C. or lower, more preferably 140° C. or lower, from the viewpoint of quick drying.

As the compound having a functional group with a cohesive energy of 20 to 60 kJ / mol in the above aspect (c), a compound having a urethane bond and an ethylenically unsaturated double bond in the molecule or a hydroxyl group and an ethylenically unsaturated double bond in the molecule Compounds with double bonds are included. Two or more of these may be included. From the viewpoint of high-speed curability, the ethylenically unsaturated double bond is preferably an acryloyl group.

Urethane acrylate is an example of a compound that has a urethane bond and an acryloyl group in its molecule. Commercially available urethane acrylates include "urethane acrylate" Ebecryl series, KRM series (both manufactured by Daicel Allnex Co., Ltd.), "Luxidia" series (manufactured by DIC Corporation), "NK oligo" U series, UA series. (both manufactured by Shin-Nakamura Chemical Co., Ltd.), "urethane acrylate" AH series, UA series, UF series (both manufactured by Kyoeisha Chemical Co., Ltd.), "Shiko" (registered trademark) series (Mitsubishi Chemical Corporation) made), etc. Two or more of these may be included. Among these, "Urethane acrylate" UF3999-BA, -AM, -HX (all manufactured by Kyoeisha Chemical Co., Ltd.) and "Shiko" (registered trademark) UV-2000B, -3000B in which the cured film exhibits rubber elasticity , -3200B, -3300B, -3500BA, -3520EA, -3700B (all manufactured by Mitsubishi Chemical Corporation) and other urethane acrylate oligomers are preferable. Solvent-free "urethane acrylate" UF3999-AM, -HX (both manufactured by Kyoeisha Chemical Co., Ltd.), "Shiko" (registered trademark) UV-2000B, -3000B, -3200B, -3300B, -3700B ( All of them are manufactured by Mitsubishi Chemical Corporation) and the like are more preferable.

Examples of compounds having a hydroxyl group and an acryloyl group in the molecule include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, and 2-hydroxy-3-phenoxypropyl acrylate. , 1,4-cyclohexanedimethanol monoacrylate, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid, 2-hydroxy-3-methacrylpropyl acrylate, pentaerythritol triacrylate, “Blemmer” (registered trademark) AE- 90U, -200, -400 (all manufactured by NOF Corporation) and other hydroxyl-terminated polyalkylene glycol monoacrylates, "Blemmer" (registered trademark) AP-200, -400, -400D, -550, -800, -1000D (both manufactured by NOF Corporation) and the like, and hydroxyl-terminated polypropylene glycol monoacrylate. Two or more of these may be included.

For the purpose of improving the physical properties of the cured film, other acrylate monomers and oligomers may be used in combination with the above-mentioned urethane acrylates and acrylates having hydroxyl groups in the molecule. For example, the combined use of tri- to hexa-functional acrylate monomers and oligomers is effective for improving tensile strength, and the combined use of mono- to bi-functional acrylates such as polyethylene glycol and polypropylene glycol is effective for improving elongation at break. be.

Further, the composition for forming a photocurable easily peelable primer layer (c) includes an organic halogen compound, a carbonyl compound, an organic peroxide, an azo compound, an azide compound, a metallocene compound, a hexaarylbisimidazole compound, It is preferable to contain conventionally known photoradical generators (also called polymerization initiators) such as organic boron compounds, disulfone compounds, oxime ester compounds, and onium salt compounds. By containing a photo-radical generator, the easily peelable primer layer-forming composition after application can be cured instantaneously by irradiating it with active energy rays.

Examples of the composition for forming an ink-repellent silicone layer include the composition exemplified as the composition for forming a layer containing diorganosiloxane units in JP-A-2021-66175, and the silicone rubber layer in WO 2019/203261. Addition reaction type, condensation reaction type, addition reaction-condensation reaction combination such as the composition exemplified as the forming composition, the composition exemplified as the first silicone layer forming composition in WO 2019/203263 and a composition for forming an ink-repellent silicone layer of the type.

Next, the easily peelable primer layer-forming composition, the ink repellent layer-forming composition, and the ink receptive layer-forming composition that are preferably used in the above aspect (2) will be described.

Examples of the easily peelable primer layer-forming composition and the ink-repellent layer-forming composition include those exemplified in the aspect (1). As the ink receptive layer forming composition, the ink receptive silicone layer forming composition described in WO 2019/203263 can be used.

In another embodiment of (2), a known composition for forming a hydrophilic layer that has been disclosed as a hydrophilic layer for a wet lithographic printing plate is used as the composition for forming an ink repellent layer, and As the composition for forming an ink-receiving layer, known compositions for forming a photosensitive layer or compositions for forming a heat-sensitive layer that have been disclosed as a photosensitive layer or a heat-sensitive layer for a wet lithographic printing plate can be used.

Next, the composition for forming an easily peelable primer layer, the composition for forming an ink receiving layer, and the composition for forming an ink repellent layer, which are preferably used in the above aspect (3), will be described.

Examples of the easily peelable primer layer-forming composition and the ink-repellent layer-forming composition include those exemplified in the aspect (1). As the composition for forming an ink-receiving layer, compositions for forming a photosensitive layer and compositions for forming a heat-sensitive layer that have been disclosed as photosensitive layers and heat-sensitive layers for waterless lithographic printing plates can be used.

Next, I will explain the method of manufacturing the printing plate. The printing plate of the invention is obtained by making the original plate of the invention. An original plate having both an easily peelable primer layer and an ink-repellent silicone layer continuously in this order on the outer peripheral surface of a cylindrical support will be described as an example. For example, the printing plate can be produced by the following two methods.

The first manufacturing method includes the method described in International Publication No. 2019/203261. Specifically, it is a method in which the composition for forming an ink-receiving portion is discharged in a pattern onto the ink-repellent silicone layer of the original plate and cured.

A second manufacturing method is the method described in JP-A-2021-66175. Specifically, the ink-repellent silicone layer of the master plate is pattern-irradiated with active energy rays, thereby changing the irradiated area to ink receptivity.

As a method for producing a printing plate from a master plate having an easy-peelable primer layer, an ink-repellent silicone layer, and an ink-receiving silicone layer in this order on the outer peripheral surface of a cylindrical support, a printing plate can be produced from the original plate. The method described in 2019/203263 can be mentioned. Specifically, it is a method of exposing the ink-repellent silicone layer by pattern-irradiating a high-output laser from the ink-receptive silicone layer side of the master and ablating the ink-receptive silicone layer in the irradiated portion.

As a method for producing a printing plate from a master plate having an easily peelable primer layer, a hydrophilic layer, a photosensitive layer or a heat-sensitive layer in this order on the outer peripheral surface of a cylindrical support, the A method in which pattern exposure is performed from a layer and development is performed using water, a liquid containing water as a main component, or a developer.

As a method for producing a printing plate from a master plate having an easily peelable primer layer, a photosensitive layer or a heat-sensitive layer, and an ink-repellent silicone layer in this order on the outer peripheral surface of a cylindrical support, an ink-repellent silicone layer is used. A method of performing pattern exposure from the layer side and developing with water, a liquid containing water as a main component, or a developer can be used.

Next, we will explain the method of manufacturing seamless printed matter.

As a method for producing seamless printed matter, it is preferable to use the printing plate, ink, and print medium described above. Further, when the printing plate is a wet lithographic printing plate, it is preferable to use the printing plate, dampening solution, ink and printing medium described above. Specifically, it preferably includes a step of applying ink to the surface of the ink-receiving portion of the printing plate, and a step of transferring the ink adhered to the surface of the ink-receiving portion to the printing medium directly or through a blanket.

FIG. 2 shows a schematic cross-sectional view of one aspect of the method for producing a seamless printed matter. Although an example using the blanket cylinder 8 will be described below, the present invention is not limited to this. may be transferred directly to the print medium 9 after the ink is applied. Further, although an example in which ink is supplied from above the print medium 9 will be described below, ink may be supplied from below the print medium 9 .

First, ink is supplied to the ink roller 5. The ink supplied to the ink roller 5 adheres to the ink receiving portion of the seamless planographic printing plate 7 at the point of contact with the seamless planographic printing plate 7 . The ink adhering to the surface of the ink receiving portion of the seamless planographic printing plate 7 is transferred to the surface of the blanket cylinder 8 at the point of contact with the blanket cylinder 8 . The ink deposited on the blanket cylinder 8 is transferred to the print medium 9 at the point of contact with the print medium 9 placed on the impression cylinder 10 . A printed matter is obtained by drying the print medium 9 after the ink transfer, if necessary. Further, when the printing plate is a wet lithographic printing plate, dampening water is supplied to the dampening water roller 6 before supplying the ink to the ink roller 5 . The dampening water supplied to the dampening water roller 6 adheres to the surface of the ink repellent portion (hydrophilic layer exposed portion) of the seamless planographic printing plate 7 at the point of contact with the seamless planographic printing plate 7 . The subsequent method of supplying ink to the ink roller 5 is the same as the method described above. The rotation speeds of the ink roller 5, dampening water roller 6, seamless lithographic printing plate 7, blanket cylinder 8 and impression cylinder 10 are not particularly limited. It can be set as appropriate.

Examples of the printing press used for producing seamless printed matter include known direct printing presses and offset printing presses, but offset printing presses are preferable in that more printed matter can be obtained by suppressing damage to the printing plate during printing. . An offset printing press consists of a feeder section, a printing section and a delivery section. The printing section has at least an ink supply section, a plate cylinder, a blanket cylinder and an impression cylinder.

As an offset printing press, an offset printing press equipped with a cooling mechanism for the rocking roller and/or the plate cylinder is preferable in terms of improving scumming resistance.

In the case of printing using an oil-soluble or water-soluble oxidative polymerization type ink, a printed matter is obtained by drying and/or curing the ink transferred to the printing medium by natural drying or heat treatment.

On the other hand, in the case of printing using oil-soluble or water-soluble active energy ray-curable ink, the ink transferred to the printing medium is instantly cured by the active energy ray from the active energy ray irradiation device, and the printed matter is obtained. preferred because it is

Active energy rays include visible rays, ultraviolet rays (UV), electron rays (EB), X-rays, particle rays, etc., but ultraviolet rays and electron rays are preferable from the point of view of the ease of handling the radiation source.

When curing with ultraviolet rays, ultraviolet irradiation devices such as high-pressure mercury lamps, xenon lamps, metal halide lamps, and ^LEDs are preferably used. Curing at a conveying speed of 50 to 150 m/min is preferable from the standpoint of productivity. In particular, when using a print medium containing a plastic film or metal as the print medium, the print medium tends to expand and contract due to the heat generated by the active energy rays. LED-UV) can be preferably used.

When curing with an electron beam, an electron beam irradiation device having an energy beam of 100 to 500 eV is preferably used.

Inks that can be preferably used in the present invention include, but are not limited to, the inks described below.

<Ink-1> Oil-soluble oxidative polymerization type ink As the oil-soluble oxidative polymerization type ink, for example, known inks that can be washed with an oil-based washing liquid disclosed in JP-A-48-004107, JP-A-01-306482, etc. and an oil-soluble oxidative polymerization type ink. In addition, the solvent component disclosed in JP-A-2005-336301, JP-A-2005-126579, JP-A-2011-144295, JP-A-2012-224823, etc. can be used as a conventional mineral oil (petroleum) component. Oil-soluble oxidative polymerization inks include soybean oil ink, vegetable oil ink, non-VOC ink, etc., in which soybean oil is replaced with a vegetable oil component.

<Ink-2> Water-soluble oxidative polymerization type ink As the water-soluble oxidative polymerization type ink, for example, known inks that can be washed with water or a water-based washing liquid disclosed in Japanese Patent Application Laid-Open No. 2009-57461, Japanese Patent No. 4522094, etc. A water-soluble oxidative polymerization type ink is mentioned.

<Ink-3> Oil-soluble active energy ray-curable ink As the oil-soluble active energy ray-curable ink, for example, it is possible to wash with an oil-based cleaning liquid disclosed in Japanese Patent No. 5158274, Japanese Patent Application Laid-Open No. 2012-211230, etc. A known active energy ray-curable ink can be used. Active energy ray-curable inks also include high-sensitivity UV inks used in power-saving (reduced lighting) UV printing and LED-UV printing.

<Ink-4> Water-soluble active energy ray-curable ink Water-soluble active energy ray-curable ink includes, for example, JP-A-2017-52817, WO 2017/047817, WO 2017/090663, etc. known water-soluble active energy ray-curable inks that can be washed with water or a water-based washing liquid disclosed in .

Among the above inks, oil-soluble or water-soluble active energy ray-curable inks cure instantly by irradiation with active energy rays after being transferred to the printing medium, so the back side can be printed and post-processed immediately. It is preferable because it has merits not found in the oxidative polymerization type ink. However, unlike conventional oxidative polymerization inks, active energy ray-curable inks do not contain any scumming-preventing components, or contain only a very small amount, so they tend to cause scumming during printing. have. Since the printing plate of the present invention has high ink repellency, oil-soluble active energy ray-curable ink and water-soluble active energy ray-curable ink can be preferably used. In addition, when cleaning ink that has adhered to various rollers, blankets, printing plates, etc. of printing presses, oil-soluble inks such as oil-soluble oxidative polymerization inks and oil-soluble active energy ray-curable inks are highly volatile and harmful. The use of organic solvents imposes a heavy burden on the human body and the environment. On the other hand, water-soluble inks such as water-soluble oxidative polymerization inks and water-soluble active energy ray-curable inks can be washed with water alone or with a washing liquid containing water as the main component. It is preferable in that it is not necessary to use a harmful organic solvent with a high viscosity, and that the burden on the human body and the environment can be remarkably suppressed. In particular, water-soluble active energy ray-curable ink can be used more preferably.

Print media include papers such as woodfree paper, art paper, coated paper, cast paper, synthetic paper, newsprint, metals such as aluminum and aluminum alloys, iron, steel, zinc and copper, polyethylene terephthalate, polyethylene, Plastic films such as polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, and polyvinyl acetal, or composites of these papers, metals, and plastic films (metal vapor-deposited or laminated paper, plastic films, and plastic films laminated paper or metal, paper laminated metal or plastic film), and the like, but are not limited to these.

Among them, in the method for producing a seamless printed matter according to the present invention, synthetic papers, metals, plastic films, metal vapor-deposited or laminated paper or plastic films, and plastic films whose printing surface is composed of metal or plastic film It is suitable for printing on non-absorbent print media such as paper or metal laminated to the ink.

Among the above, the printing surface of the printing medium, such as synthetic paper, plastic films, plastic film-laminated paper or metal, whose printing surface is made of plastic film, should be coated with a primer to improve adhesion. A surface treatment such as resin coating, corona discharge treatment, or plasma treatment may be applied.

As for the shape of the print medium, it is preferable to use a roll-shaped long print medium. By printing by the roll-to-roll method using the printing plate of the present invention and a roll-shaped long print medium, it is possible to mass-produce high-definition seamless printed matter without seams in picture patterns.

The thickness of the ink coating film (ink cured film) on the print medium is preferably 0.1 to 50 μm. By keeping the thickness of the ink coating film within the above range, the ink cost can be reduced while maintaining good print quality.

Next, we will explain how to regenerate the cylindrical support from the original plate or printing plate.

Since the original plate or printing plate of the present invention has the easily peelable primer layer continuously adjacent to the outer peripheral surface of the cylindrical support, the easily peelable primer layer from the original plate or printing plate and further on the outer peripheral surface thereof. The cylindrical support can be easily regenerated simply by peeling off each functional layer in a dry process. Complex operations such as surface polishing are not required. That is, the method for regenerating a cylindrical support of the present invention comprises peeling the easily peelable primer layer into a film from the outer peripheral surface of the cylindrical support of the original plate of the present invention or the printing plate of the present invention by a dry process. be.

The easily peelable primer layer and each functional layer provided on the outer peripheral surface are peeled off together in a dry process to form a film. By continuously providing both the repulsive layer and other functional layers, the original plate can be manufactured repeatedly. Since the cylindrical support can be used repeatedly, it is economically extremely advantageous.

Next, the easily peelable primer layer-forming composition of the present invention will be described. The definition of the easily peelable primer layer-forming composition is as described above. The easily peelable primer layer-forming composition of the present invention contains a compound having a functional group with a cohesive energy of 20 to 60 kJ/mol. As the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol, a compound having a urethane bond and/or a hydroxyl group is preferable, and polyurethane is more preferable. As the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol, a compound having an ethylenically unsaturated double bond is preferred, and urethane acrylate is more preferred.

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

Examples of the composition for forming an easily peelable primer layer of the present invention include those exemplified as the composition for forming an easily peelable primer layer that is preferably used in the above-described method for producing an original plate.

The present invention will be described in more detail below with reference to examples.

　Evaluation in each example and comparative example was performed by the following method.

<Evaluation method in each example/comparative example>
(1) Evaluation of primer layer (1-1) Ease of reproduction of plate cylinder sleeve (ease of peeling of primer layer)
For the original plates produced in each of the examples and comparative examples, the easily peelable primer layer was peeled off from the outer peripheral surface of the plate cylinder sleeve by a dry process, and the easiness of remanufacture of the plate cylinder sleeve was evaluated. The ease of reproduction of the plate cylinder sleeve was rated as follows.
A: The plate cylinder sleeve is extremely easy to recycle (the easily peelable primer layer can be easily peeled off in the form of a film in a dry process).
B: Easy to recycle the plate cylinder sleeve (The easily peelable primer layer can be peeled off in a dry process, but the easily peelable primer breaks during peeling.)
C: The plate cylinder sleeve cannot be regenerated (the primer layer cannot be peeled off in a dry process).

(1-2) Adhesion between the plate cylinder sleeve and the easily peelable primer layer In each example and comparative example, a razor was applied to a randomly selected position from the easily peelable primer layer formed on the outer peripheral surface of the plate cylinder sleeve. Using, a strip of width: 0.1 m, length: 0.1 m is cut, and a digital force gauge: ZTA-500N (manufactured by Imada Co., Ltd.) is used to remove the easily peelable primer layer from the plate cylinder sleeve. Measure the force [N / 0.1 m] when peeling 0.05 m in the length direction, multiply the obtained peel force [N / 0.1 m] by 10, and the plate cylinder sleeve and the easy peeling primer The adhesion force [N/m] with the layer was calculated.

(1-3) Film strength of the easily peelable primer layer The tensile strength [N/mm ² ] of the easily peelable primer layer obtained by the method described in (1-3-1) below and the following (1-3-) The film strength [N/mm] of the easily peelable primer layer was obtained from the product of the average thickness [mm] of the easily peelable primer layer obtained by the method of 2). In order to make it easier to understand the relationship between the adhesion force between the plate cylinder sleeve and the easily peelable primer layer, the film strength [N/mm] of the easily peelable primer layer is multiplied by 1,000 and the unit is [N/m]. and

(1-3-1) Tensile strength of easily peelable primer layer Using the easily peelable primer layer peeled from the plate cylinder sleeve in the above (1-1), according to the method specified in JIS K 6251: 2017. , the tensile strength of the easily peelable primer layer was measured. For the measurement, a tensile tester: "Tensilon" (registered trademark) RTF-1350 (manufactured by A&D Co., Ltd.) was used, and an air jaw was used for sandwiching the sample.

(1-3-2) Average thickness of easily peelable primer layer After embedding the easily peelable primer layer peeled from the plate cylinder sleeve in (1-1) above in resin, the cross section of the sample prepared by the ultrathin section method was magnified and observed using a scanning electron microscope: SU3900 (manufactured by Hitachi High-Tech Co., Ltd.). The average thickness of the easily peelable primer layer was obtained by measuring the thickness of 10 randomly selected locations from the easily peelable primer layer in the vertical cross-sectional image and calculating the number average value.

(1-4) Elongation at break of easily peelable primer layer Using the easily peelable primer layer peeled from the plate cylinder sleeve in (1-1) above, an easy The elongation at break of the releasable primer layer was measured. For the measurement, a tensile tester: "Tensilon" (registered trademark) RTF-1350 was used, and an air jaw was used to clamp the sample.

(2) Printing evaluation The printing plate obtained by the method described in each example and comparative example was mounted on the plate cylinder shaft of an EB offset printing machine: OFFSET CI/8 (manufactured by COMEXI) under the printing conditions shown below. A maximum length of 100,000 m has been printed.
<Printing conditions>
Ink roller: #8000 (manufactured by Meiwa Rubber Industry Co., Ltd.)
Cylindrical blanket: EPDM blanket (manufactured by Kinyo Co., Ltd.)
Water-soluble EB ink: Offset EB ink F type FE1908 process 4 colors (manufactured by Samsung Ink Co., Ltd.)
Fountain water: Purified water (used only in Example 16, which prints using a seamless wet lithographic printing plate)
Ink component non-absorbent print medium: “EMBRET” (registered trademark) PTM-12 (rolled biaxially stretched PET film, thickness: 12 μm, printing surface: easy adhesion treatment, manufactured by Unitika Ltd.)
Plate surface temperature: 25-28°C
Printing speed: 100 m/min <Ink curing conditions>
EB irradiation dose: 40 kGy
EB irradiation atmosphere: in a nitrogen atmosphere.

(2-1) Possibility of seamless printing The printed matter was visually observed to evaluate the propriety of seamless printing of intermittent patterns and continuous patterns. The evaluation of whether or not seamless printing was possible was performed as follows.
A: Seamless printing is possible (no pattern seams are visible on the printed matter)
B: Seamless printing not possible (seams of the pattern are observed on the printed matter).

(2-2) Image reproducibility Cut out a printed matter near 5,000 m from the start of printing, place it on OK “Top Coat” (registered trademark) + that is made up of 5 sheets, and use a magnifying glass of 50 times the halftone dot part. magnified and observed. Image reproducibility was rated as follows.
A: Reproduce halftone dots of 175 lpi (resolution: 2400 dpi) for AM screening at 1 to 99%.

(2-3) Printing durability Printing was carried out up to a maximum length of 100,000 m, and the limit printing length [m] at which good printed matter was continuously obtained was evaluated as printing durability. The brackets in the column of printing durability in Table 1 represent the following.
(P): Printing limit due to peeling of the primer layer (P layer) (S): Printing limit due to peeling of the silicone layer (S layer) (F): Damage to the silicone portion filled between the head and bottom of the plate Print limit by.

[Example 1]
Using a cylindrical slit die coater (manufactured by Toray Engineering Co., Ltd.), the following easily peelable primer layer forming composition-1 is applied to the outer peripheral surface of an aluminum alloy plate cylinder sleeve, and the composition is applied at 170 ° C. for 10 minutes. A continuous easily peelable primer layer having an average thickness of 25 μm was formed by heating.

<Composition for forming an easily peelable primer layer-1>
The following components (a-1) and (b-1) were put into a container, and mixed by stirring until the components became homogeneous to obtain an easily peelable primer layer-forming composition-1.
(a-1) Solvent: N,N-dimethylformamide (boiling point at 1 atm: 153°C): 500.0 parts by mass (b-1) Polyurethane solution: "Crisbon" (registered trademark) 9004 (solid concentration: 20 % by mass, solvent: N,N-dimethylformamide/2-butanone (boiling point at 1 atm: 80° C.), hydroxyl group in polyurethane molecule: none, manufactured by DIC Corporation): 500.0 parts by mass.

Next, using a cylindrical slit die coater, the following ink-repellent silicone layer-forming composition-1 was applied to the outer peripheral surface of the easily peelable primer layer and heated at 150° C. for 5 minutes to form a continuous coating having an average thickness of 20 μm. A master plate was obtained by providing an ink-repellent silicone layer.

<Composition for forming an ink-repellent silicone layer-1>
The following components (a-2), (b-2) and (c-2) were charged into a container and mixed with stirring until the components were uniform. Dry nitrogen was bubbled through the resulting solution for 20 minutes to remove water in the solution. Component (d-2) was added to the resulting solution and mixed with stirring for 10 minutes. The component (e-2) was added immediately before coating and mixed by stirring to obtain an ink-repellent silicone layer-forming composition-1.
(a-2) Isoparaffin-based solvent: "Isopar" (registered trademark) E (manufactured by ExxonMobil Chemical): 295.00 parts by mass (b-2) A siloxane compound having two or more vinyl groups in the molecule (both Terminal dimethylvinylsiloxy-polydimethylsiloxane): DMS-V35 (manufactured by GELES Inc., weight average molecular weight: 49,500, number of vinyl groups in the molecule: 2.0): 91.00 parts by mass (c-2) molecule A siloxane compound having 3 or more SiH groups within (both terminal trimethylsiloxy-methylhydrosiloxane-dimethylsiloxane copolymer): HMS-301 (manufactured by GELES Inc., weight average molecular weight: 1,950, H derived from SiH group Group concentration: 0.41% by mass, number of SiH groups in molecule: 8.0): 6.0 parts by mass (d-2) Silane coupling agent and reaction inhibitor: vinyltris(methylethylketoximino)silane:3. 0 parts by mass (e-2) Reaction catalyst (platinum mixture): XC94-C4326 (manufactured by Momentive Performance Materials Japan LLC, solid content concentration: 1% by mass): 5.0 parts by mass.

Using an _F2 excimer laser drawing device (wavelength: 157 nm), the ink-repellent silicone layer of the above-mentioned master is subjected to ultraviolet drawing at an exposure amount of 300 mJ/cm ² in a vacuum, thereby making a master and printing a plate. got

[Example 2]
A printing plate was obtained in the same manner as in Example 1, except that the easily peelable primer layer forming composition-1 was changed to the following easily peelable primer layer forming composition-2.

<Composition for forming an easily peelable primer layer-2>
The following components (a-3) and (b-3) were charged into a container and mixed with stirring until the components became uniform, thereby obtaining an easily peelable primer layer-forming composition-2.
(a-3) Solvent: N,N-dimethylformamide: 666.7 parts by mass (b-3) Polyurethane solution: "Crisbon" (registered trademark) 8966 (solid concentration: 30% by mass, solvent: N,N- Dimethylformamide, hydroxyl group in polyurethane molecule: none, manufactured by DIC Corporation): 333.3 parts by mass.

[Example 3]
A printing plate was obtained in the same manner as in Example 1, except that the easily peelable primer layer forming composition-1 was changed to the following easily peelable primer layer forming composition-3.

<Composition for forming an easily peelable primer layer-3>
The following components (a-4) and (b-4) were put into a container, and mixed with stirring until the components became uniform to obtain an easily peelable primer layer-forming composition-3.
(a-4) Solvent: N,N-dimethylformamide: 600.0 parts by mass (b-4) Polyurethane solution: "Samplen" (registered trademark) LQ-T1333 (solid concentration: 25 mass%, solvent: N, N-dimethylformamide, hydroxyl group in polyurethane molecule: none, manufactured by Sanyo Chemical Industries, Ltd.): 400.0 parts by mass.

[Example 4]
A printing plate was obtained in the same manner as in Example 3, except that the average thickness of the easily peelable primer layer was changed from 25 µm to 15 µm.

[Example 5]
A printing plate was obtained in the same manner as in Example 3, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 12 μm.

[Example 6]
The easily peelable primer layer forming composition-1 was changed to the following easily peelable primer layer forming composition-4, the heating temperature was changed from 170°C to 80°C, and the average thickness of the easily peelable primer layer was changed from 25 µm to 30 µm. A printing plate was obtained in the same manner as in Example 1 except that each was changed.

<Composition for forming an easily peelable primer layer-4>
The following components (a-5) and (b-5) were put into a container and mixed with stirring until the components became homogeneous to obtain an easily peelable primer layer-forming composition-4.
(a-5) Solvent: Solvent: 2-butanone: 666.7 parts by mass (b-5) Polyurethane solution: "Samplen" (registered trademark) IB-1700D (solid concentration: 30% by mass, solvent: 2-butanone /2-propanol (boiling point at 1 atm: 83°C) = 45/1 parts by weight, hydroxyl group in polyurethane molecule: present, manufactured by Sanyo Chemical Industries, Ltd.): 333.3 parts by weight.

[Example 7]
In the same manner as in Example 1 except that the easily peelable primer layer forming composition-1 was changed to the following easily peelable primer layer forming composition-5 and the heating temperature was changed from 170 ° C. to 80 ° C. Got the print version.

<Composition for forming an easily peelable primer layer-5>
Zirconia balls: The following (a-6), (b -6) and (c-6) components were added and sealed, then set on a small ball mill rotation stand (manufactured by AS ONE Corporation) and dispersed at a rotation speed of 0.4 m / sec for 7 days, An easily peelable primer layer-forming composition-5 was obtained.
(a-6) Solvent: 2-butanone: 712.7 parts by mass (b-6) Polyurethane solution: "Samplen" (registered trademark) IB-1700D: 233.3 parts by mass (c-6) Inorganic particles: "AEROSIL "(registered trademark) RX200 (fumed silica surface-modified with a trimethylsilyl group, manufactured by Nippon Aerosil Co., Ltd.): 54.0 parts by mass.

[Example 8]
In the same manner as in Example 1, except that the easily peelable primer layer forming composition-1 was changed to the following easily peelable primer layer forming composition-6, and the heating temperature was changed from 170 ° C. to 120 ° C. Got the print version.

<Composition for forming an easily peelable primer layer-6>
The following components (a-7) and (b-7) were put into a container and mixed with stirring until the components became homogeneous to obtain an easily peelable primer layer-forming composition-6.
(a-7) Purified water (boiling point at 1 atmosphere: 100°C): 500.0 parts by mass Non-reactive type, hydroxyl group in polyurethane molecule: none, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 500.0 parts by mass.

[Example 9]
A printing plate was obtained in the same manner as in Example 8, except that the drying conditions for the easily peelable primer layer were changed from heating at 170°C for 10 minutes to heating at 30°C for 3 hours.

[Example 10]
Using a cylindrical slit die coater, the following easily peelable primer layer forming composition-7 was applied to the outer peripheral surface of the aluminum alloy plate cylinder sleeve, and an LED system line type UV irradiator: UD90 (Panasonic Devices SUNX (manufactured by Co., Ltd., wavelength: 385 nm) in the same manner as in Example 1, except that a continuous easily peelable primer layer having an average thickness of 25 μm was formed by irradiating with ultraviolet rays for 1 minute and curing. Got the print version.

<Composition for forming an easily peelable primer layer-7>
The following components (a-8) and (b-8) were put into a container and mixed with stirring until the components became homogeneous to obtain an easily peelable primer layer-forming composition-7.
(a-8) Polyester-based urethane acrylate oligomer: UF-3999AM (acryloylmorpholine 30% by mass diluted product, hydroxyl group in polyester-based urethane acrylate oligomer molecule: none, manufactured by Kyoeisha Chemical Co., Ltd.): 960.0 parts by mass ( b-8) Photo-radical generator: “Irgacure” (registered trademark) 184 (manufactured by BASF Japan Ltd.): 40.0 parts by mass [Example 11]
A printing plate was obtained in the same manner as in Example 10, except that the easily peelable primer layer forming composition-7 was changed to the following easily peelable primer layer forming composition-8.

<Composition for forming an easily peelable primer layer-8>
The following components (a-9) and (b-9) were put into a container and mixed with stirring until the components became uniform, thereby obtaining an easily peelable primer layer-forming composition-8.
(a-9) NK ester APG-700 (polypropylene glycol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.): 660.0 parts by mass (b-9) “light acrylate” (registered trademark) PE-3A (pentaerythritol Triacrylate, manufactured by Kyoeisha Chemical Co., Ltd.): 300.0 parts by mass (c-9) Photoradical generator: "Irgacure" (registered trademark) 184 (manufactured by BASF Japan Co., Ltd.): 40.0 parts by mass [Implementation Example 12]
A printing plate was obtained in the same manner as in Example 1, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 50 μm.

[Example 13]
A master was obtained in the same manner as in Example 1, except that the ink-repellent silicone layer-forming composition-1 was changed to the following ink-repellent silicone layer-forming composition-2.

<Composition for forming an ink-repellent silicone layer-2>
The following components (a-10), (b-10), (c-10) and (d-10) were charged into a container and mixed with stirring until the components were uniform. Dry nitrogen was bubbled through the resulting solution for 20 minutes to remove water in the solution. Component (e-10) was put into the resulting solution and mixed with stirring for 10 minutes. The component (f-10) was added immediately before coating and mixed by stirring to obtain an ink-repellent silicone layer-forming composition-2.
(a-10) “Isopar” (registered trademark) E: 895.0 parts by mass (b-10) a siloxane compound having two or more vinyl groups in the molecule (both ends trimethylsiloxy-vinylmethylsiloxane-dimethylsiloxane copolymer ): VDT-954 (manufactured by GELEST Inc., weight average molecular weight: 225,000, vinyl group concentration: 4.29% by mass, number of vinyl groups in the molecule: 357.2): 62.0 parts by mass (c-10 ) Liquid with a surface tension of 30 mN / m or less at 25 ° C.: KF-96-50cs (dimethyl silicone oil, weight average molecular weight: 3,780, surface tension at 25 ° C.: 20.8 mN / m, 1 atmospheric pressure environment Mass reduction rate after heating at 150° C. for 24 hours: 0.1% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.): 20.0 parts by mass (d-10) Siloxane compound having 3 or more SiH groups in the molecule (Both ends trimethylsiloxy-methylhydrosiloxane-dimethylsiloxane copolymer): HMS-064 (manufactured by GELEST Inc., weight average molecular weight: 55,000, H group concentration derived from SiH group: 0.08 mass%, intramolecular Number of SiH groups: 44.4): 15.0 parts by mass (e-10) Vinyltris(methylethylketoximino)silane: 3.0 parts by mass (f-10) XC94-C4326: 5.0 parts by mass.

Next, the following composition-1 for forming an ink-receiving portion was applied using a sub femto inkjet processing device (manufactured by SIJ Technology Co., Ltd.) under the conditions of an ejection droplet volume of 2 femtoliters. A printing plate was obtained by pattern ejection onto the layer and heating at 150° C. for 5 minutes.

<Composition for forming an ink-receiving portion-1>
The following components (a-11), (b-11), (c-11) and (d-11) were charged into a container and mixed with stirring until the components were uniform. Dry nitrogen was bubbled through the resulting solution for 20 minutes to remove water in the solution. Immediately before application, component (e-11) was added and mixed with stirring to obtain composition-1 for forming an ink-receiving portion.
(a-11) “Isopar” (registered trademark) C: 95.0 parts by mass (b-11) VDT-954: 70.0 parts by mass (c-11) HMS-993: 30.0 parts by mass (d- 11) 2-methyl-3-butyn-2-ol: 1.5 parts by mass (e-11) XC94-C4326: 3.5 parts by mass.

[Example 14]
Using a cylindrical slit die coater, the easily peelable primer layer-forming composition-1 was applied to the outer peripheral surface of an aluminum alloy plate cylinder sleeve and heated at 170 ° C. for 10 minutes to obtain an average thickness of 25 μm. A continuous, easily strippable primer layer was provided.

Then, using a cylindrical slit die coater, the following ink-repellent silicone layer-forming composition-3 was applied to the outer peripheral surface of the easily peelable primer layer and heated at 150° C. for 5 minutes to obtain a continuous coating having an average thickness of 20 μm. An ink repellent silicone layer was provided.

<Composition for forming an ink-repellent silicone layer-3>
The following components (a-12), (b-12) and (c-12) were put into a container and mixed with stirring until the components were uniform. Dry nitrogen was bubbled through the resulting solution for 20 minutes to remove water in the solution. Component (d-12) was put into the resulting solution and mixed with stirring for 10 minutes. Immediately before coating, component (e-12) was added and mixed with stirring to obtain composition-3 for forming an ink-repellent silicone layer. (a-12) “Isopar” (registered trademark) E: 895.0 parts by mass (b-12) VDT-954: 82.0 parts by mass (c-12) Siloxane having 3 or more SiH groups in the molecule Compound (both ends trimethylsiloxy-methylhydrosiloxane-dimethylsiloxane copolymer): HMS-064 (manufactured by GELEST Inc., weight average molecular weight: 55,000, H group concentration derived from SiH group: 0.08 mass%, intramolecular of SiH groups: 44.4): 15.0 parts by mass (d-12) vinyltris(methylethylketoximino)silane: 3.0 parts by mass (e-12) XC94-C4326: 5.0 parts by mass.

Next, using a cylindrical slit die coater, the ink-receptive silicone layer-forming composition-1 was applied to the outer peripheral surface of the ink-repellent silicone layer and heated at 150° C. for 5 minutes to obtain an average thickness of 0.5. A master plate was obtained by providing a continuous ink receptive silicone layer of 4 μm.

An ArF excimer pulse laser (wavelength: 193 nm) was used to irradiate the ink receptive silicone layer side of the obtained master with a laser irradiation energy density of 150 mJ/cm ² , a pulse repetition frequency of 10 Hz, and an atmosphere of the laser irradiation area: a nitrogen atmosphere. Then, the entire ink-receivable silicone layer and the upper portion of the ink-repellent silicone layer in the laser-irradiated area were ablated to make a master plate to obtain a printing plate.

[Example 15]
Using a cylindrical slit die coater, the easily peelable primer layer-forming composition-1 was applied to the outer peripheral surface of an aluminum alloy plate cylinder sleeve and heated at 170 ° C. for 10 minutes to obtain an average thickness of 25 μm. A continuous easily peelable primer layer was provided.

Next, using a cylindrical slit die coater, the following hydrophilic layer-forming composition-1 was applied to the outer peripheral surface of the easily peelable primer layer, heated at 150 ° C. for 5 minutes, and continuously having an average thickness of 3 μm. A hydrophilic layer was provided.

<Hydrophilic layer-forming composition-1>
The following components (a-13), (b-13) and (c-13) were put into a container and stirred and mixed until the components became uniform to obtain a hydrophilic layer forming composition-1. .
(a-13) Hydrophilic polymer obtained from Synthesis Example 1 below: 10 parts by mass (b-13) N-Hydroxyethylxylylenediamine: 1 part by mass (c-13) Purified water: 100 parts by mass.

<Synthesis Example 1>
Vinyl acetate: 60 g, methyl acrylate: 40 g, benzoyl peroxide: 0.5 g as a polymerization initiator were weighed, and these were added to partially saponified polyvinyl alcohol: 3 g and NaCl: 10 g as a dispersion stabilizer. Water: 300 ml dispersed inside. The resulting dispersion was stirred at 65° C. for 6 hours to carry out suspension polymerization. 8.6 g of the obtained copolymer was added to a saponification reaction liquid consisting of 200 g of methanol, 10 g of water, and 40 ml of 5N NaOH, suspended with stirring, and subjected to a saponification reaction at 25° C. for 1 hour. After that, the temperature was raised to 65° C., and the saponification reaction was further carried out for 5 hours. The resulting saponified product was thoroughly washed with methanol and then freeze-dried to obtain a hydrophilic polymer.

Next, using a cylindrical slit die coater, the following ink receptive heat-sensitive layer forming composition-1 was applied to the outer peripheral surface of the hydrophilic layer and heated at 70° C. for 5 minutes to obtain an average thickness of 3 μm. A continuous ink receptive thermosensitive layer was provided to obtain a master plate.

<Composition for Forming Ink Receptive Thermosensitive Layer-1>
The following components were put into a container and mixed with stirring until the components became homogeneous to obtain a composition-1 for forming an ink receptive heat-sensitive layer.
(a-14) "KAYASORB" (registered trademark) IR-820B (infrared absorbing dye, manufactured by Nippon Kayaku Co., Ltd.): 5 parts by mass (b-14) Aluminum chelate D (aluminum monoacetylacetonate bisethylacetoacetate , Kawaken Fine Chemicals Co., Ltd.): 20 parts by mass (c-14) epoxy ester 80 MFA (epoxy acrylate, Kyoeisha Chemical Co., Ltd.)): 40 parts by mass (d-14) polyvinyl alcohol AL-06 (Nippon Gosei Kagaku Co., Ltd.): 10 parts by mass (e-14) Polyurethane emulsion "Superflex" (registered trademark) R-5100 (Daiichi Kogyo Seiyaku Co., Ltd.): 40 parts by mass (f-14) "Cataloid" (registered trademark) SI-30 (aqueous dispersion of colloidal silica fine particles having an average particle size of 0.01 to 0.014 μm, manufactured by Catalysts & Chemicals Co., Ltd.): 10 parts by mass (g-14) Purified water: 700 parts by mass ( h-14) Ethylene glycol monoethyl ether: 200 parts by mass.

The ink receptive heat-sensitive layer side of the obtained master was pattern-exposed using a semiconductor laser (wavelength: 808 nm) under the condition of laser irradiation energy density: 200 mJ/cm ² , and then the surface was covered with cotton soaked with water. The ink receptive heat-sensitive layer in the unexposed areas was removed by wiping to prepare the original plate, thereby obtaining a printing plate in which the lower ink-repellent hydrophilic layer was exposed.

[Example 16]
Using a cylindrical slit die coater, the easily peelable primer layer-forming composition-1 was applied to the outer peripheral surface of an aluminum alloy plate cylinder sleeve and heated at 170 ° C. for 10 minutes to obtain an average thickness of 25 μm. A continuous, easily strippable primer layer was provided.

Next, using a cylindrical slit die coater, the following ink receptive thermosensitive layer forming composition-2 was applied to the outer peripheral surface of the easily peelable primer layer and heated at 150° C. for 5 minutes to obtain an average thickness of 1 μm. A continuous ink receptive thermosensitive layer was provided.

<Composition for Forming Ink Receptive Thermosensitive Layer-2>
The following components were put into a container and mixed with stirring until the components became uniform to obtain a composition-2 for forming an ink receptive heat-sensitive layer.
(a-15) Phenol-formaldehyde novolac resin: "Sumilite Resin" (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 45.0 parts by weight (b-15) Polyurethane solution: "Nipporan" (registered trademark) 5196 (manufactured by Nippon Polyurethane Co., Ltd., solid content concentration: 30% by weight): 62.5 parts by weight (c-15) Infrared absorption dye: PROJET 825LDI (manufactured by Avecia Co., Ltd.): 12.0 parts by weight (d-15 ) Titanium di-n-butoxybis (acetylacetonate) solution: “Nasem” (registered trademark) titanium (manufactured by Nippon Kagaku Sangyo Co., Ltd., solid content concentration: 73% by weight): 28.5 parts by weight (e-15) Polyoxypropylenediamine/glycidyl methacrylate/3-glycidoxypropyltrimethoxysilane = 1/3/1 molar reactant (solid concentration: 50% by weight): 22.5 parts by weight (f-15) Tetrahydrofuran: 717 .0 parts by weight (g-15) Ethanol: 112.5 parts by weight.

Next, using a cylindrical slit die coater, the following ink-repellent silicone layer-forming composition-4 was applied to the outer peripheral surface of the ink receptive thermosensitive layer and heated at 150°C for 5 minutes to obtain an average thickness. A 3 μm continuous ink-repellent silicone layer was provided to obtain a master plate.

<Composition for forming ink-repellent silicone layer-4>
The following components (a-16), (b-16), and (c-16) were put into a container and mixed with stirring until the components became uniform. Dry nitrogen was bubbled through the resulting solution for 20 minutes to remove water in the solution. Components (d-16), (e-16), and (f-16) were added to the resulting solution and mixed with stirring for 10 minutes, and then component (g-16) was added and mixed with stirring for another 10 minutes. bottom. The component (h-16) was added immediately before coating and mixed by stirring to obtain an ink-repellent silicone layer-forming composition-4.
(a-16) "Isopar" (registered trademark) E: 894.05 parts by weight (b-16) DMS-V35: 73.68 parts by weight (c-16) KF-96-50cs: 20.00 parts by weight ( d-16) SiH group-containing compound (both ends trimethylsiloxy-methylhydrosiloxane-dimethylsiloxane copolymer): "HMS"-301 (manufactured by GELEST Inc., weight average molecular weight: 1,960, SiH group equivalent: 245, in the molecule SiH groups: 8): 2.27 parts by weight (e-16) vinyltris(methylethylketoximino)silane: 1.00 parts by weight (f-16) phenyltriacetoxysilane: 3.00 parts by weight (g-16 ) Reaction inhibitor: γ-picoline: 1.00 parts by weight (h-16) XC94-C4326: 5.00 parts by weight.

The ink-repellent silicone layer side of the resulting master plate was pattern-exposed using a semiconductor laser (wavelength: 808 nm) under the condition of laser irradiation energy density: 200 mJ/cm ² , and then the surface was wiped with water-soaked cotton. The original plate was made by removing the ink-repellent silicone layer in the exposed areas by wiping to obtain a printing plate.

[Example 17]
A printing plate was obtained in the same manner as in Example 16, except that the easily peelable primer layer forming composition-1 was changed to the easily peelable primer layer forming composition-3.

[Example 18]
A printing plate was obtained in the same manner as in Example 17, except that the average thickness of the easily peelable primer layer was changed from 25 µm to 15 µm.

[Example 19]
A printing plate was obtained in the same manner as in Example 17, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 12 μm.

[Example 20]
The easily peelable primer layer forming composition-1 was added to the easily peelable primer layer forming composition-4, the heating temperature was changed from 170° C. to 80° C., and the average thickness of the easily peelable primer layer was changed from 25 μm to 30 μm. A printing plate was obtained in the same manner as in Example 16 except for the changes.

[Example 21]
Printing was performed in the same manner as in Example 16, except that the easily peelable primer layer forming composition-1 was replaced with the easily peelable primer layer forming composition-5, and the heating temperature was changed from 170°C to 80°C. got the edition.

[Example 22]
Printing was performed in the same manner as in Example 16, except that the easily peelable primer layer forming composition-1 was replaced with the easily peelable primer layer forming composition-6, and the heating temperature was changed from 170°C to 120°C. got the edition.

[Example 23]
A printing plate was obtained in the same manner as in Example 22, except that the drying conditions for the easily peelable primer layer were changed from heating at 170°C for 10 minutes to heating at 30°C for 3 hours.

[Example 24]
Using a cylindrical slit die coater, the composition for forming an easily peelable primer layer-7 is applied to the outer peripheral surface of an aluminum alloy plate cylinder sleeve, and an LED type line type UV irradiation device: UD90 is used to apply ultraviolet rays. A printing plate was obtained in the same manner as in Example 16, except that a continuous easily peelable primer layer having an average thickness of 25 μm was provided by irradiating and curing for 1 minute.

[Example 25]
A printing plate was obtained in the same manner as in Example 24, except that the easily peelable primer layer forming composition-7 was changed to the easily peelable primer layer forming composition-8.

[Example 26]
A printing plate was obtained in the same manner as in Example 16, except that the average thickness of the easily peelable primer layer was changed from 25 µm to 50 µm.

[Comparative Example 1]
A printing plate was obtained in the same manner as in Example 1, except that no easily peelable primer layer was provided.

[Comparative Example 2]
A printing plate was obtained in the same manner as in Example 1, except that the easily peelable primer layer-forming composition-1 was changed to the following primer layer-forming composition-1.

<Primer layer forming composition-1>
The following components (a-17) and (b-17) were put into a container and mixed with stirring until the components became uniform, whereby a composition 12 for forming a peelable primer layer was obtained.
(a-17) Epoxy resin: "jER" (registered trademark) 828 (bisphenol A liquid epoxy resin, manufactured by Mitsubishi Chemical Corporation): 500.0 parts by mass (b-17) Polyamine: "Jefamine" (registered Trademark) T-403 (trimethylolpropane poly(oxypropylene)triamine, manufactured by Huntsman): 500.0 parts by mass.

[Comparative Example 3]
A shrink tube: Copalon PTF (material: PET, thickness: 80 μm, manufactured by Gunze Kobunshi Co., Ltd.) is placed so as to cover the outer peripheral surface of the plate cylinder sleeve made of aluminum alloy, and heated at 120 ° C. for 5 minutes to form a shrink tube. was heat-shrunk, and the shrink tube was fixed to the outer peripheral surface of the plate cylinder sleeve. Next, double-sided tape: 777 (manufactured by Teraoka Seisakusho Co., Ltd.) was attached to the outer peripheral surface of the shrink tube after heat shrinking, and then a sheet-shaped waterless lithographic printing plate precursor: TAC-VT4 (manufactured by Toray Industries, Inc.) ) was fixed by winding a waterless lithographic printing plate. The ink-repellent silicone layer-forming composition-1 was filled in the gap (about 0.5 mm) between the plate head and plate bottom of the wound sheet-like waterless lithographic printing plate and heated at 150° C. for 5 minutes. A master plate was obtained by curing the resin.

[Example 27]
A printing plate was obtained in the same manner as in Example 1, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 15 μm and the heating time of the easily peelable primer layer was changed from 10 minutes to 20 minutes.

[Example 28]
A printing plate was obtained in the same manner as in Example 1, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 15 μm and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes.

[Example 29]
A printing plate was obtained in the same manner as in Example 1, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 20 μm and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes.

[Example 30]
The average thickness of the easily peelable primer layer was changed from 25 μm to 20 μm, the heating temperature of the easily peelable primer layer was changed from 170° C. to 185° C., and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes. A printing plate was obtained in the same manner as in Example 1 except for the above.

[Example 31]
The average thickness of the easily peelable primer layer was changed from 25 μm to 30 μm, the heating temperature of the easily peelable primer layer was changed from 170° C. to 185° C., and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes. A printing plate was obtained in the same manner as in Example 1 except for the above.

[Example 32]
The average thickness of the easily peelable primer layer was changed from 25 μm to 30 μm, the heating temperature of the easily peelable primer layer was changed from 170° C. to 200° C., and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes. A printing plate was obtained in the same manner as in Example 1 except for the above.

[Example 33]
A printing plate was obtained in the same manner as in Example 16, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 15 μm and the heating time of the easily peelable primer layer was changed from 10 minutes to 20 minutes.

[Example 34]
A printing plate was obtained in the same manner as in Example 16, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 15 μm and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes.

[Example 35]
A printing plate was obtained in the same manner as in Example 16, except that the average thickness of the easily peelable primer layer was changed from 25 μm to 20 μm and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes.

[Example 36]
The average thickness of the easily peelable primer layer was changed from 25 μm to 20 μm, the heating temperature of the easily peelable primer layer was changed from 170° C. to 185° C., and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes. A printing plate was obtained in the same manner as in Example 16 except that

[Example 37]
The average thickness of the easily peelable primer layer was changed from 25 μm to 30 μm, the heating temperature of the easily peelable primer layer was changed from 170° C. to 185° C., and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes. A printing plate was obtained in the same manner as in Example 16 except that

[Example 38]
The average thickness of the easily peelable primer layer was changed from 25 μm to 30 μm, the heating temperature of the easily peelable primer layer was changed from 170° C. to 200° C., and the heating time of the easily peelable primer layer was changed from 10 minutes to 30 minutes. A printing plate was obtained in the same manner as in Example 16 except that

Table 1 shows the evaluation results for Examples 1 to 26 and Comparative Examples 1 to 3. Table 2 shows the evaluation results of Examples 27 to 38. Since no primer layer was provided in Comparative Examples 1 and 3, the column of "(1) Evaluation of primer layer" in Table 1 is left blank. In Comparative Example 2, the primer layer could not be peeled off from the plate cylinder sleeve by a dry process. column is left blank.

A Intermittent pattern B Continuous pattern D Printing direction E Seamless lithographic printing plate F Seamless printed matter P Printing R1 1st round of printing plate R2 2nd round of printing plate 1 Image area 2 Non-image area 3 Printed medium 4 Transfer image 5 Ink roller 6 dampening solution roller 7 seamless lithographic printing plate 8 blanket cylinder 9 print medium 10 impression cylinder

Claims (22)

1. A seamless lithographic printing plate precursor having an easy-peelable primer layer and an ink-repellent layer in this order continuously on the outer peripheral surface of a cylindrical support.
2. 2. The seamless lithographic printing plate precursor as claimed in claim 1, wherein the adhesive strength between said cylindrical support and said easily peelable primer layer is less than the film strength of said easily peelable primer layer.
3. The seamless lithographic printing plate precursor as claimed in claim 1, wherein the adhesive strength between said cylindrical support and said easily peelable primer layer is 10 to 2,000 N/m.
4. The seamless lithographic printing plate precursor as claimed in Claim 1, wherein the easily peelable primer layer has an elongation at break of 10 to 1,000%.
5. The seamless lithographic printing plate precursor as claimed in Claim 1, wherein the easily peelable primer layer has an average thickness of 15 to 500 µm.
6. The seamless lithographic printing plate precursor as claimed in Claim 1, wherein the easily peelable primer layer contains a compound having a functional group with a cohesive energy of 20 to 60 kJ/mol.
7. 2. The seamless lithographic printing plate precursor according to claim 1, wherein no covalent bond is formed between the easily peelable primer layer and the outer circumferential surface of the cylindrical support.
8. 7. The seamless lithographic printing plate precursor as claimed in claim 6, wherein the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol comprises polyurethane.
9. The seamless lithographic printing plate precursor as claimed in Claim 1, wherein said ink repellent layer is a silicone layer.
10. The seamless lithographic printing plate precursor according to claim 1, further comprising an ink receptive layer continuously between the easily peelable primer layer and the ink repellent layer or further outside the ink repellent layer.
11. The seamless lithographic printing plate precursor as claimed in Claim 10, wherein the ink-receiving layer is a photosensitive layer or a heat-sensitive layer.
12. A seamless lithographic printing plate obtained by plate-making the seamless lithographic printing plate precursor according to any one of claims 1 to 11.
13. From the outer peripheral surface of the cylindrical support of the seamless lithographic printing plate precursor according to any one of claims 1 to 11 or the seamless lithographic printing plate according to claim 12, the easily peelable primer layer is formed into a film by a dry process. A method for regenerating a cylindrical support, which is peeled off.
14. 14. A method for producing a seamless lithographic printing plate precursor, comprising continuously forming an easy-peelable primer layer and an ink-repellent layer in this order on the outer peripheral surface of a cylindrical support regenerated by the method according to claim 13.
15. A method for producing a seamless lithographic printing plate precursor according to any one of claims 1 to 11, wherein the composition for forming an easily peelable primer layer is applied to the outer peripheral surface of the cylindrical support, and heated or not. A method for producing a seamless lithographic printing plate precursor, wherein the easily peelable primer layer is formed by drying under heating.
16. A method for producing a seamless lithographic printing plate precursor according to any one of claims 1 to 11, wherein the composition for forming an easily peelable primer layer is applied to the outer peripheral surface of the cylindrical support, and an active energy ray is applied. A method for producing a seamless lithographic printing plate precursor, wherein the easily peelable primer layer is formed by curing a composition for forming an easily peelable primer layer by irradiation.
17. 17. The method for producing a seamless lithographic printing plate precursor according to claim 15 or 16, wherein the cylindrical support regenerated by the method according to claim 13 is used as the cylindrical support.
18. A composition for forming an easily peelable primer layer, containing a compound having a functional group with a cohesive energy of 20 to 60 kJ/mol.
19. 19. The composition for forming an easily peelable primer layer according to claim 18, wherein the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol comprises a compound having a urethane bond and/or a hydroxyl group.
20. The composition for forming an easily peelable primer layer according to claim 18 or 19, wherein the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol further has an ethylenically unsaturated double bond in the molecule.
21. 20. The composition for forming an easily peelable primer layer according to claim 19, wherein the compound having a functional group with a cohesive energy of 20 to 60 kJ/mol comprises polyurethane.
22. The composition for forming an easily peelable primer layer according to any one of claims 18 to 21, further comprising inorganic particles.

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